observed annual cycle: Topics by Science.gov

Observed and Projected Changes to the Precipitation Annual Cycle

DOE PAGES

Marvel, Kate; Biasutti, Michela; Bonfils, Celine; ...

2017-06-08

Anthropogenic climate change is predicted to cause spatial and temporal shifts in precipitation patterns. These may be apparent in changes to the annual cycle of zonal mean precipitation P. Trends in the amplitude and phase of the P annual cycle in two long-term, global satellite datasets are broadly similar. Model-derived fingerprints of externally forced changes to the amplitude and phase of the P seasonal cycle, combined with these observations, enable a formal detection and attribution analysis. Observed amplitude changes are inconsistent with model estimates of internal variability but not attributable to the model-predicted response to external forcing. This mismatch betweenmore » observed and predicted amplitude changes is consistent with the sustained La Niña–like conditions that characterize the recent slowdown in the rise of the global mean temperature. However, observed changes to the annual cycle phase do not seem to be driven by this recent hiatus. Furthermore these changes are consistent with model estimates of forced changes, are inconsistent (in one observational dataset) with estimates of internal variability, and may suggest the emergence of an externally forced signal.« less
The Annual Glaciohydrology Cycle in the Ablation Zone of the Greenland Ice Sheet: Part 2. Observed and Modeled Ice Flow

NASA Technical Reports Server (NTRS)

Colgan, William Terence; Rajaram, Harihar; Anderson, Robert S.; Steffen, Konrad; Zwally, H. Jay; Phillips, Thomas; Abdalati, Waleed

2012-01-01

Ice velocities observed in 2005/06 at three GPS stations along the Sermeq Avannarleq flowline, West Greenland, are used to characterize an observed annual velocity cycle. We attempt to reproduce this annual ice velocity cycle using a 1-D ice-flow model with longitudinal stresses coupled to a 1-D hydrology model that governs an empirical basal sliding rule. Seasonal basal sliding velocity is parameterized as a perturbation of prescribed winter sliding velocity that is proportional to the rate of change of glacier water storage. The coupled model reproduces the broad features of the annual basal sliding cycle observed along this flowline, namely a summer speed-up event followed by a fall slowdown event. We also evaluate the hypothesis that the observed annual velocity cycle is due to the annual calving cycle at the terminus. We demonstrate that the ice acceleration due to a catastrophic calving event takes an order of magnitude longer to reach CU/ETH ('Swiss') Camp (46km upstream of the terminus) than is observed. The seasonal acceleration observed at Swiss Camp is therefore unlikely to be the result of velocity perturbations propagated upstream via longitudinal coupling. Instead we interpret this velocity cycle to reflect the local history of glacier water balance.
Ionospheric winter anomaly and annual anomaly observed from Formosat-3/COSMIC Radio Occultation observations during the ascending phase of solar cycle 24

NASA Astrophysics Data System (ADS)

Sai Gowtam, V.; Tulasi Ram, S.

2017-10-01

Ionospheric winter and annual anomalies have been investigated during the ascending phase of solar cycle 24 using high-resolution global 3D - data of the FORMOSAT - 3/COSMIC (Formosa satellite - 3/Constellation Observing System for Meterology, Ionosphere and Climate) radio occultation observations. Our detailed analysis shows that the occurrence of winter anomaly at low-latitudes is confined only to the early morning to afternoon hours, whereas, the winter anomaly at mid-latitudes is almost absent at all local times during the ascending phase of solar cycle 24. Further, in the topside ionosphere (altitudes of 400 km and above), the winter anomaly is completely absent at all local times. In contrast, the ionospheric annual anomaly is consistently observed at all local times and altitudes during this ascending phase of solar cycle 24. The annual anomaly exhibits strong enhancements over southern EIA crest latitudes during day time and around Weddle Sea Anomaly (WSA) region during night times. The global mean annual asymmetry index is also computed to understand the altitudinal variation. The global mean AI maximizes around 300-500 km altitudes during the low solar active periods (2008-10), whereas it extends up to 600 km during moderate to high (2011) solar activity period. These findings from our study provide new insights to the current understanding of the annual anomaly.
Annual Cycle of Surface Longwave Radiation

NASA Technical Reports Server (NTRS)

Mlynczak, Pamela E.; Smith, G. Louis; Wilber, Anne C.; Stackhouse, Paul W.

2011-01-01

The annual cycles of upward and downward longwave fluxes at the Earth s surface are investigated by use of the NASA/GEWEX Surface Radiation Budget Data Set. Because of the immense difference between the heat capacity of land and ocean, the surface of Earth is partitioned into these two categories. Principal component analysis is used to quantify the annual cycles. Over land, the first principal component describes over 95% of the variance of the annual cycle of the upward and downward longwave fluxes. Over ocean the first term describes more than 87% of these annual cycles. Empirical orthogonal functions show the corresponding geographical distributions of these cycles. Phase plane diagrams of the annual cycles of upward longwave fluxes as a function of net shortwave flux show the thermal inertia of land and ocean.
Hemispheric Differences in Tropical Lower Stratospheric Transport and Tracers Annual Cycle

NASA Technical Reports Server (NTRS)

Tweedy, Olga; Waugh, D.; Stolarski, R.; Oman, L.

2016-01-01

Transport of long-lived tracers (such as O, CO, and N O) in the lower stratosphere largely determines the composition of the entire stratosphere. Stratospheric transport includes the mean residual circulation (with air rising in the tropics and sinking in the polar and middle latitudes), plus two-way isentropic (quasi-horizontal) mixing by eddies. However, the relative importance of two transport components remains uncertain. Previous studies quantified the relative role of these processes based on tropics-wide average characteristics under common assumption of well-mixed tropics. However, multiple instruments provide us with evidence that show significant differences in the seasonal cycle of ozone between the Northern (0-20N) and Southern (0-20S) tropical (NT and ST respectively) lower stratosphere. In this study we investigate these differences in tracer seasonality and quantify transport processes affecting tracers annual cycle amplitude using simulations from Goddard Earth Observing System Chemistry Climate Model (GEOSCCM) and Whole Atmosphere Community Climate Model (WACCM) and compare them to observations from the Microwave Limb Sounder (MLS) on the Aura satellite. We detect the observed contrast between the ST and NT in GEOSCCM and WACCM: annual cycle in ozone and other chemical tracers is larger in the NT than in the ST but opposite is true for the annual cycle in vertical advection. Ozone budgets in the models, analyzed based on the Transformed Eulerian Mean (TEM) framework, demonstrate a major role of quasi-horizontal mixing vertical advection in determining the NTST ozone distribution and behavior. Analysis of zonal variations in the NT and ST ozone annual cycles further suggests important role of North American and Asian Summer Monsoons (associated with strong isentropic mixing) on the lower stratospheric ozone in the NT. Furthermore, multi model comparison shows that most CCMs reproduce the observed characteristic of ozone annual cycle quite well. Thus
The Annual Cycle of the Japan Sea Throughflow

NASA Astrophysics Data System (ADS)

Kida, S.; Qiu, B.; Yang, J.; Lin, X.

2016-02-01

The mechanism responsible for the annual cycle of the flows through the straits of Japan Sea is investigated using a two-layer model. Japan Sea is one of the marginal sea located in the western North Pacific that is separated from the Pacific by the islands of Japan. Three narrow and shallow straits, the Tsushima, Tsugaru, and Soya Straits, connect this sea towards the Pacific Ocean and Okhotsk Sea and observations show that the flow through these three straits vary annually with a maximum transport in summer-fall and a minimum transport in winter. The variability is large for Soya (north) and Tsushima (south) Straits but weak for the Tsugaru Strait (middle). We find the subpolar winds located to the north of Soya Strait to be the primary forcing agent of this annual cycle rather than the subtropical winds located to the east of Japan. The subpolar winds generate baroclinic Kelvin waves that perturb the sea surface height at the Soya Strait, cause barotropic adjustment to occur within the Japan Sea, and change the flow at the other straits. The shallow topography at the straits plays an important role. This mechanism explains why the annual cycle at the three straits occur almost synchronously. We also find the around-island integral constraint a useful tool for explaining how the magnitude of the annual cycle at the three straits are controlled. The theorem show the magnitude and direction of the flow controlled largely by the ratio of the meridional length of the two islands that is bounded by the three straits..
CO2 Annual and Semiannual Cycles from Satellite Retrievals and Models

NASA Astrophysics Data System (ADS)

Jiang, X.; Crisp, D.; Olsen, E. T.; Kulawik, S. S.; Miller, C. E.; Pagano, T. S.; Yung, Y. L.

2014-12-01

We have compared satellite CO2 retrievals from the Greenhouse gases Observing SATellite (GOSAT), Atmospheric Infrared Sounder (AIRS), and Tropospheric Emission Spectrometer (TES) with in-situ measurements from the Earth System Research Laboratory (NOAA-ESRL) Surface CO2 and Total Carbon Column Observing Network (TCCON), and utilized zonal means to characterize variability and distribution of CO2. In general, zonally averaged CO2 from the three satellite data sets are consistent with the surface and TCCON XCO2 data. Retrievals of CO2 from the three satellites show more (less) CO2 in the northern hemisphere than that in the southern hemisphere in the northern hemispheric winter (summer) season. The difference between the three satellite CO2 retrievals might be related to the different averaging kernels in the satellites CO2 retrievals. A multiple regression method was used to calculate the CO2 annual cycle and semiannual cycle amplitudes from different satellite CO2 retrievals. The CO2 annual cycle and semiannual cycle amplitudes are largest at the surface, as seen in the NOAA-ESRL CO2 data sets. The CO2 annual cycle and semiannual cycle amplitudes in the GOSAT XCO2, AIRS mid-tropospheric CO2, and TES mid-tropospheric CO2 are smaller compared with those from the surface CO2. Similar regression analysis was applied to the Model for OZone And Related chemical Tracers-2 (MOZART-2) and CarbonTracker model CO2. The convolved model CO2 annual cycle and semiannual cycle amplitudes are similar to those from the satellite CO2 retrievals, although the model tends to under-estimate the CO2 seasonal cycle amplitudes in the northern hemisphere mid-latitudes from the comparison with GOSAT and TES CO2 and underestimate the CO2 semi-annual cycle amplitudes in the high latitudes from the comparison with AIRS CO2. The difference between model and satellite CO2 can be used to identify possible deficiency in the model and improve the model in the future.
The annual cycles of phytoplankton biomass

USGS Publications Warehouse

Winder, M.; Cloern, J.E.

2010-01-01

Terrestrial plants are powerful climate sentinels because their annual cycles of growth, reproduction and senescence are finely tuned to the annual climate cycle having a period of one year. Consistency in the seasonal phasing of terrestrial plant activity provides a relatively low-noise background from which phenological shifts can be detected and attributed to climate change. Here, we ask whether phytoplankton biomass also fluctuates over a consistent annual cycle in lake, estuarine-coastal and ocean ecosystems and whether there is a characteristic phenology of phytoplankton as a consistent phase and amplitude of variability. We compiled 125 time series of phytoplankton biomass (chloro-phyll a concentration) from temperate and subtropical zones and used wavelet analysis to extract their dominant periods of variability and the recurrence strength at those periods. Fewer than half (48%) of the series had a dominant 12-month period of variability, commonly expressed as the canonical spring-bloom pattern. About 20 per cent had a dominant six-month period of variability, commonly expressed as the spring and autumn or winter and summer blooms of temperate lakes and oceans. These annual patterns varied in recurrence strength across sites, and did not persist over the full series duration at some sites. About a third of the series had no component of variability at either the six-or 12-month period, reflecting a series of irregular pulses of biomass. These findings show that there is high variability of annual phytoplankton cycles across ecosystems, and that climate-driven annual cycles can be obscured by other drivers of population variability, including human disturbance, aperiodic weather events and strong trophic coupling between phytoplankton and their consumers. Regulation of phytoplankton biomass by multiple processes operating at multiple time scales adds complexity to the challenge of detecting climate-driven trends in aquatic ecosystems where the noise to
The annual cycle of nitrate and net community production in surface waters of the Southern Ocean observed with SOCCOM profiling floats

NASA Astrophysics Data System (ADS)

Johnson, K. S.; Plant, J. N.; Sakamoto, C.; Coletti, L. J.; Sarmiento, J. L.; Riser, S.; Talley, L. D.

2016-12-01

Sixty profiling floats with ISUS and SUNA nitrate sensors have been deployed in the Southern Ocean (south of 30 degrees S) as part of the SOCCOM (Southern Ocean Carbon and Climate Observations and Modeling) program and earlier efforts. These floats have produced detailed records of the annual cycle of nitrate concentration throughout the region from the surface to depths near 2000 m. In surface waters, there are clear cycles in nitrate concentration that result from uptake of nitrate during austral spring and summer. These changes in nitrate concentration were used to compute the annual net community production over this region. NCP was computed using a simplified version of the approach detailed by Plant et al. (2016, Global Biogeochemical Cycles, 30, 859-879, DOI: 10.1002/2015GB005349). At the time the abstract was written 41 complete annual cycles were available from floats deployed before the austral summer of 2015/2016. After filtering the data to remove floats that crossed distinct frontal boundaries, floats with other anomalies, and floats in sub-tropical waters, 23 cycles were available. A preliminary assessment of the data yields an NCP of 2.8 +/- 0.95 (1 SD) mol C/m2/y after integrating to 100 m depth and converting nitrate uptake to carbon using the Redfield ratio. This preliminary assessment ignores vertical transport across the nitracline and is, therefore, a minimum estimate. The number of cycles available for analysis will increase rapidly, as 32 of the floats were deployed in the austral summer of 2015/2016 and have not yet been analyzed.
Annual nitrate drawdown observed by SOCCOM profiling floats and the relationship to annual net community production

NASA Astrophysics Data System (ADS)

Johnson, Kenneth S.; Plant, Joshua N.; Dunne, John P.; Talley, Lynne D.; Sarmiento, Jorge L.

2017-08-01

Annual nitrate cycles have been measured throughout the pelagic waters of the Southern Ocean, including regions with seasonal ice cover and southern hemisphere subtropical zones. Vertically resolved nitrate measurements were made using in situ ultraviolet spectrophotometer (ISUS) and submersible ultraviolet nitrate analyzer (SUNA) optical nitrate sensors deployed on profiling floats. Thirty-one floats returned 40 complete annual cycles. The mean nitrate profile from the month with the highest winter nitrate minus the mean profile from the month with the lowest nitrate yields the annual nitrate drawdown. This quantity was integrated to 200 m depth and converted to carbon using the Redfield ratio to estimate annual net community production (ANCP) throughout the Southern Ocean south of 30°S. A well-defined, zonal mean distribution is found with highest values (3-4 mol C m-2 yr-1) from 40 to 50°S. Lowest values are found in the subtropics and in the seasonal ice zone. The area weighted mean was 2.9 mol C m-2 yr-1 for all regions south of 40°S. Cumulative ANCP south of 50°S is 1.3 Pg C yr-1. This represents about 13% of global ANCP in about 14% of the global ocean area.Plain Language SummaryThis manuscript reports on 40 annual cycles of nitrate observed by chemical sensors on SOCCOM profiling floats. The annual drawdown in nitrate concentration by phytoplankton is used to assess the spatial variability of annual net community production in the Southern Ocean. This ANCP is a key component of the global carbon cycle and it exerts an important control on atmospheric carbon dioxide. We show that the results are consistent with our prior understanding of Southern Ocean ANCP, which has required decades of observations to accumulate. The profiling floats now enable annual resolution of this key process. The results also highlight spatial variability in ANCP in the Southern Ocean. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008ClDy...31..823W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008ClDy...31..823W">The modulated annual cycle: an alternative reference frame for climate anomalies</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Wu, Zhaohua; Schneider, Edwin K.; Kirtman, Ben P.; Sarachik, E. S.; Huang, Norden E.; Tucker, Compton J. 2008-12-01 In climate science, an anomaly is the deviation of a quantity from its annual cycle. There are many ways to define annual cycle. Traditionally, this annual cycle is taken to be an exact repeat of itself year after year. This stationary annual cycle may not reflect well the intrinsic nonlinearity of the climate system, especially under external forcing. In this paper, we re-examine the reference frame for anomalies by re-examining the annual cycle. We propose an alternative reference frame for climate anomalies, the modulated annual cycle (MAC) that allows the annual cycle to change from year to year, for defining anomalies. In order for this alternative reference frame to be useful, we need to be able to define the instantaneous annual cycle: we therefore also introduce a new method to extract the MAC from climatic data. In the presence of a MAC, modulated in both amplitude and frequency, we can then define an alternative version of an anomaly, this time with respect to the instantaneous MAC rather than a permanent and unchanging AC. Based on this alternative definition of anomalies, we re-examine some familiar physical processes: in particular SST re-emergence and ENSO phase locking to the annual cycle. We find that the re-emergence mechanism may be alternatively interpreted as an explanation of the change of the annual cycle instead of an explanation of the interannual to interdecadal persistence of SST anomalies. We also find that the ENSO phase locking can largely be attributed to the residual annual cycle (the difference of the MAC and the corresponding traditional annual cycle) contained in the traditional anomaly, and, therefore, can be alternatively interpreted as a part of the annual cycle phase locked to the annual cycle itself. In addition to the examples of reinterpretation of physics of well known climate phenomena, we also present an example of the implications of using a MAC against which to define anomalies. We show that using MAC as a reference </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFM.A53E..03W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFM.A53E..03W">The Modulated Annual Cycle: An Alternative Reference Frame for Climate Anomalies</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Wu, Z. 2007-12-01 In climate science, an anomaly is the deviation of a quantity from its annual cycle (AC). There are many ways to define annual cycle. Traditionally, the annual cycle is taken to be an exact repetition of itself year after year. This stationary annual cycle may not reflect well the intrinsic nonlinearity of the climate system, especially under external forcing. In this study, we have reexamined the reference frame for anomalies by reexamining the annual cycle. We propose an alternative reference frame, the modulated annual cycle (MAC) that allows the annual cycle to change from year to year, for defining anomalies. In order for this alternative reference frame to be useful, we need to be able to define the instantaneous annual cycle. We therefore also introduce a new method to extract the MAC from climatic data. In the presence of an MAC, modulated in both amplitude and frequency, we can then define an alternative version of an anomaly, this time with respect to the instantaneous MAC rather than a permanent and unchanging AC. Based on this alternative definition of anomalies, we reexamine some familiar physical processes: in particular, the sea surface temperature (SST) reemergence and the ENSO phase locking to the annual cycle. We find that the re-emergence mechanism may be alternatively interpreted as an explanation of the change of the annual cycle instead of the interannual to interdecadal persistence of SST anomalies. We also find that the ENSO phase locking can largely be attributed to the residual annual cycle (the difference of the MAC and the corresponding traditional annual cycle) contained in the traditional anomaly, and, therefore, can be alternatively interpreted as a part of the annual cycle phase locked to the annual cycle itself. Two additional examples are also presented of the implications of using a MAC against which to define anomalies. We show that using MAC as a reference framework for anomaly can bypass the difficulty brought by concepts such </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNG31B0173D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNG31B0173D">Comparison of methods for extracting annual cycle with changing amplitude in climate science</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Deng, Q.; Fu, Z. 2017-12-01 Changes of annual cycle gains a growing concern recently. The basic hypothesis regards annual cycle as constant. Climatology mean within a time period is usually used to depict the annual cycle. Obviously this hypothesis contradicts with the fact that annual cycle is changing every year. For the lack of a unified definition about annual cycle, the approaches adopted in extracting annual cycle are various and may lead to different results. The precision and validity of these methods need to be examined. In this work we numerical experiments with known monofrequent annual cycle are set to evaluate five popular extracting methods: fitting sinusoids, complex demodulation, Ensemble Empirical Mode Decomposition (EEMD), Nonlinear Mode Decomposition (NMD) and Seasonal trend decomposition procedure based on loess (STL). Three different types of changing amplitude will be generated: steady, linear increasing and nonlinearly varying. Comparing the annual cycle extracted by these methods with the generated annual cycle, we find that (1) NMD performs best in depicting annual cycle itself and its amplitude change, (2) fitting sinusoids, complex demodulation and EEMD methods are more sensitive to long-term memory(LTM) of generated time series thus lead to overfitting annual cycle and too noisy amplitude, oppositely the result of STL underestimate the amplitude variation (3)all of them can present the amplitude trend correctly in long-time scale but the errors on account of noise and LTM are common in some methods over short time scales. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930060270&hterms=atmospheric+pressure&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Datmospheric%2Bpressure','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930060270&hterms=atmospheric+pressure&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Datmospheric%2Bpressure">The Martian annual atmospheric pressure cycle - Years without great dust storms</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Tillman, James E.; Johnson, Neal C.; Guttorp, Peter; Percival, Donald B. 1993-01-01 A model of the annual cycle of pressure on Mars for a 2-yr period, chosen to include one year at the Viking Lander 2 and to minimize the effect of great dust storms at the 22-deg N Lander 1 site, was developed by weighted least squares fitting of the Viking Lander pressure measurements to an annual mean, and fundamental and the first four harmonics of the annual cycle. Close agreement was obtained between the two years, suggesting that an accurate representation of the annual CO2 condensation-sublimation cycle can be established for such years. This model is proposed as the 'nominal' Martian annual pressure cycle, and applications are suggested. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ClDy...50.1091D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ClDy...50.1091D">The impact of inter-annual variability of annual cycle on long-term persistence of surface air temperature in long historical records</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Deng, Qimin; Nian, Da; Fu, Zuntao 2018-02-01 Previous studies in the literature show that the annual cycle of surface air temperature (SAT) is changing in both amplitude and phase, and the SAT departures from the annual cycle are long-term correlated. However, the classical definition of temperature anomalies is based on the assumption that the annual cycle is constant, which contradicts the fact of changing annual cycle. How to quantify the impact of the changing annual cycle on the long-term correlation of temperature anomaly variability still remains open. In this paper, a recently developed data adaptive analysis tool, the nonlinear mode decomposition (NMD), is used to extract and remove time-varying annual cycle to reach the new defined temperature anomalies in which time-dependent amplitude of annual cycle has been considered. By means of detrended fluctuation analysis, the impact induced by inter-annual variability from the time-dependent amplitude of annual cycle has been quantified on the estimation of long-term correlation of long historical temperature anomalies in Europe. The results show that the classical climatology annual cycle is supposed to lack inter-annual fluctuation which will lead to a maximum artificial deviation centering around 600 days. This maximum artificial deviation is crucial to defining the scaling range and estimating the long-term persistence exponent accurately. Selecting different scaling range could lead to an overestimation or underestimation of the long-term persistence exponent. By using NMD method to extract the inter-annual fluctuations of annual cycle, this artificial crossover can be weakened to extend a wider scaling range with fewer uncertainties. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017GeoRL..44.3737W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017GeoRL..44.3737W">Dynamics of upwelling annual cycle in the equatorial Atlantic Ocean</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Wang, Li-Chiao; Jin, Fei-Fei; Wu, Chau-Ron; Hsu, Huang-Hsiung 2017-04-01 The annual upwelling is an important component of the equatorial Atlantic annual cycle. A simple theory is proposed using the framework of Zebiak-Cane (ZC) ocean model for insights into the dynamics of the upwelling annual cycle. It is demonstrated that in the Atlantic equatorial region this upwelling is dominated by Ekman processing in the west, whereas in the east it is primarily owing to shoaling and deepening of the thermocline resulting from equatorial mass meridional recharge/discharge and zonal redistribution processes associated with wind-driven equatorial ocean waves. This wind-driven wave upwelling plays an important role in the development of the annual cycle in the sea surface temperature of the cold tongue in the eastern equatorial Atlantic. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NatGe..10..118B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NatGe..10..118B">Annual boom-bust cycles of polar phytoplankton biomass revealed by space-based lidar</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Behrenfeld, Michael J.; Hu, Yongxiang; O'Malley, Robert T.; Boss, Emmanuel S.; Hostetler, Chris A.; Siegel, David A.; Sarmiento, Jorge L.; Schulien, Jennifer; Hair, Johnathan W.; Lu, Xiaomei; Rodier, Sharon; Scarino, Amy Jo 2017-02-01 Polar plankton communities are among the most productive, seasonally dynamic and rapidly changing ecosystems in the global ocean. However, persistent cloud cover, periods of constant night and prevailing low solar elevations in polar regions severely limit traditional passive satellite ocean colour measurements and leave vast areas unobserved for many consecutive months each year. Consequently, our understanding of the annual cycles of polar plankton and their interannual variations is incomplete. Here we use space-borne lidar observations to overcome the limitations of historical passive sensors and report a decade of uninterrupted polar phytoplankton biomass cycles. We find that polar phytoplankton dynamics are categorized by `boom-bust' cycles resulting from slight imbalances in plankton predator-prey equilibria. The observed seasonal-to-interannual variations in biomass are predicted by mathematically modelled rates of change in phytoplankton division. Furthermore, we find that changes in ice cover dominated variability in Antarctic phytoplankton stocks over the past decade, whereas ecological processes were the predominant drivers of change in the Arctic. We conclude that subtle and environmentally driven imbalances in polar food webs underlie annual phytoplankton boom-bust cycles, which vary interannually at each pole. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017BGeo...14.1383L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017BGeo...14.1383L">Drivers of multi-century trends in the atmospheric CO2 mean annual cycle in a prognostic ESM</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Liptak, Jessica; Keppel-Aleks, Gretchen; Lindsay, Keith 2017-03-01 The amplitude of the mean annual cycle of atmospheric CO2 is a diagnostic of seasonal surface-atmosphere carbon exchange. Atmospheric observations show that this quantity has increased over most of the Northern Hemisphere (NH) extratropics during the last 3 decades, likely from a combination of enhanced atmospheric CO2, climate change, and anthropogenic land use change. Accurate climate prediction requires accounting for long-term interactions between the environment and carbon cycling; thus, analysis of the evolution of the mean annual cycle in a fully prognostic Earth system model may provide insight into the multi-decadal influence of environmental change on the carbon cycle. We analyzed the evolution of the mean annual cycle in atmospheric CO2 simulated by the Community Earth System Model (CESM) from 1950 to 2300 under three scenarios designed to separate the effects of climate change, atmospheric CO2 fertilization, and land use change. The NH CO2 seasonal amplitude increase in the CESM mainly reflected enhanced primary productivity during the growing season due to climate change and the combined effects of CO2 fertilization and nitrogen deposition over the mid- and high latitudes. However, the simulations revealed shifts in key climate drivers of the atmospheric CO2 seasonality that were not apparent before 2100. CO2 fertilization and nitrogen deposition in boreal and temperate ecosystems were the largest contributors to mean annual cycle amplification over the midlatitudes for the duration of the simulation (1950-2300). Climate change from boreal ecosystems was the main driver of Arctic CO2 annual cycle amplification between 1950 and 2100, but CO2 fertilization had a stronger effect on the Arctic CO2 annual cycle amplitude during 2100-2300. Prior to 2100, the NH CO2 annual cycle amplitude increased in conjunction with an increase in the NH land carbon sink. However, these trends decoupled after 2100, underscoring that an increasing atmospheric CO2 annual </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMSH11C..05B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMSH11C..05B">Predictions of Sunspot Cycle 24: A Comparison with Observations</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Bhatt, N. J.; Jain, R. 2017-12-01 The space weather is largely affected due to explosions on the Sun viz. solar flares and CMEs, which, however, in turn depend upon the magnitude of the solar activity i e. number of sunspots and their magnetic configuration. Owing to these space weather effects, predictions of sunspot cycle are important. Precursor techniques, particularly employing geomagnetic indices, are often used in the prediction of the maximum amplitude of a sunspot cycle. Based on the average geomagnetic activity index aa (since 1868 onwards) for the year of the sunspot minimum and the preceding four years, Bhatt et al. (2009) made two predictions for sunspot cycle 24 considering 2008 as the year of sunspot minimum: (i) The annual maximum amplitude would be 92.8±19.6 (1-sigma accuracy) indicating a somewhat weaker cycle 24 as compared to cycles 21-23, and (ii) smoothed monthly mean sunspot number maximum would be in October 2012±4 months (1-sigma accuracy). However, observations reveal that the sunspot minima extended up to 2009, and the maximum amplitude attained is 79, with a monthly mean sunspot number maximum of 102.3 in February 2014. In view of the observations and particularly owing to the extended solar minimum in 2009, we re-examined our prediction model and revised the prediction results. We find that (i) The annual maximum amplitude of cycle 24 = 71.2 ± 19.6 and (ii) A smoothed monthly mean sunspot number maximum in January 2014±4 months. We discuss our failure and success aspects and present improved predictions for the maximum amplitude as well as for the timing, which are now in good agreement with the observations. Also, we present the limitations of our forecasting in the view of long term predictions. We show if year of sunspot minimum activity and magnitude of geomagnetic activity during sunspot minimum are taken correctly then our prediction method appears to be a reliable indicator to forecast the sunspot amplitude of the following solar cycle. References:Bhatt, N </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20010124073','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20010124073">Importance of the Annual Cycles of SST and Solar Irradiance for Circulation and Rainfall: A Climate Model Simulation Study</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Sud, Yogesh C.; Lau, William K. M.; Walker, G. K.; Mehta, V. M. 2001-01-01 Annual cycle of climate and precipitation is related to annual cycle of sunshine and sea-surface temperatures. Understanding its behavior is important for the welfare of humans worldwide. For example, failure of Asian monsoons can cause widespread famine and grave economic disaster in the subtropical regions. For centuries meteorologists have struggled to understand the importance of the summer sunshine and associated heating and the annual cycle of sea-surface temperatures (SSTs) on rainfall in the subtropics. Because the solar income is pretty steady from year to year, while SSTs depict large interannual variability as consequence of the variability of ocean dynamics, the influence of SSTs on the monsoons are better understood through observational and modeling studies whereas the relationship of annual rainfall to sunshine remains elusive. However, using NASA's state of the art climate model(s) that can generate realistic climate in a computer simulation, one can answer such questions. We asked the question: if there was no annual cycle of the sunshine (and its associated land-heating) or the SST and its associated influence on global circulation, what will happen to the annual cycle of monsoon rains? By comparing the simulation of a 4-year integration of a baseline Control case with two parallel anomaly experiments: 1) with annual mean solar and 2) with annual mean sea-surface temperatures, we were able to draw the following conclusions: (1) Tropical convergence zone and rainfall which moves with the Sun into the northern and southern hemispheres, specifically over the Indian, African, South American and Australian regions, is strongly modulated by the annual cycles of SSTs as well as solar forcings. The influence of the annual cycle of solar heating over land, however, is much stronger than the corresponding SST influence for almost all regions, particularly the subtropics; (2) The seasonal circulation patterns over the vast land-masses of the Northern </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li class="active">1</li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_2" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li class="active">2</li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="21"> <li> <a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=plant+AND+life+AND+cycle&pg=6&id=EJ277114','ERIC'); return false;" href="https://eric.ed.gov/?q=plant+AND+life+AND+cycle&pg=6&id=EJ277114">Transparency Master: The Annual Aphid Cycle.</a> <a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a> Sessions, Mary Lynne 1983-01-01 Aphids, often referred to as plant lice, can be found in great numbers on stems, leaves, and flowers of many plants. In many cases these organisms are potentially harmful to their plant hosts. Provided is a description of the annual life cycle of the aphid and an accompanying transparency master. (Author/JN) </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004cosp...35..413P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004cosp...35..413P">Semi-annual Sq-variation in solar activity cycle</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Pogrebnoy, V.; Malosiev, T. The peculiarities of semi-annual variation in solar activity cycle have been studied. The data from observatories having long observational series and located in different latitude zones were used. The following observatories were selected: Huancayo (magnetic equator), from 1922 to 1959; Apia (low latitudes), from 1912 to 1961; Moscow (middle latitudes), from 1947 to 1965. Based on the hourly values of H-components, the average monthly diurnal amplitudes (a difference between midday and midnight values), according to five international quiet days, were computed. Obtained results were compared with R (relative sunspot numbers) in the ranges of 0-30R, 40-100R, and 140-190R. It was shown, that the amplitude of semi-annual variation increases with R, from minimum to maximum values, on average by 45%. At equatorial Huancayo observatory, the semi-annual Sq(H)-variation appears especially clearly: its maximums take place at periods of equinoxes (March-April, September-October), and minimums -- at periods of solstices (June-July, December-January). At low (Apia observatory) and middle (Moscow observatory) latitudes, the character of semi-annual variation is somewhat different: it appears during the periods of equinoxes, but considerably less than at equator. Besides, with the growth of R, semi-annual variation appears against a background of annual variation, in the form of second peaks (maximum in June). At observatories located in low and middle latitudes, second peaks become more appreciable with an increase of R (March-April and September-October). During the periods of low solar activity, they are insignificant. This work has been carried out with the support from International Scientific and Technology Center (Project #KR-214). </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ACP....1715045H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ACP....1715045H">Annual cycle of Scots pine photosynthesis</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Hari, Pertti; Kerminen, Veli-Matti; Kulmala, Liisa; Kulmala, Markku; Noe, Steffen; Petäjä, Tuukka; Vanhatalo, Anni; Bäck, Jaana 2017-12-01 Photosynthesis, i.e. the assimilation of atmospheric carbon to organic molecules with the help of solar energy, is a fundamental and well-understood process. Here, we connect theoretically the fundamental concepts affecting C3 photosynthesis with the main environmental drivers (ambient temperature and solar light intensity), using six axioms based on physiological and physical knowledge, and yield straightforward and simple mathematical equations. The light and carbon reactions in photosynthesis are based on the coherent operation of the photosynthetic machinery, which is formed of a complicated chain of enzymes, membrane pumps and pigments. A powerful biochemical regulation system has emerged through evolution to match photosynthesis with the annual cycle of solar light and temperature. The action of the biochemical regulation system generates the annual cycle of photosynthesis and emergent properties, the state of the photosynthetic machinery and the efficiency of photosynthesis. The state and the efficiency of the photosynthetic machinery is dynamically changing due to biosynthesis and decomposition of the molecules. The mathematical analysis of the system, defined by the very fundamental concepts and axioms, resulted in exact predictions of the behaviour of daily and annual patterns in photosynthesis. We tested the predictions with extensive field measurements of Scots pine (Pinus sylvestris L.) photosynthesis on a branch scale in northern Finland. Our theory gained strong support through rigorous testing. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70024143','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70024143">Characterization of annual reproductive cycles for pond-reared Florida largemouth bass Micropterus salmoides floridanus</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Gross, T.S.; Wieser, C.M.; Sepulveda, M.S.; Wiebe, J.J.; Schoeb, T.R.; Denslow, N.D. 2002-01-01 The annual reproductive cycle of hatchery-raised largemouth bass (Florida subspecies Micropterus salmoides floridanus) was characterized over a one-year period. Largemouth bass have a distinct annual reproductive cycle with a spring spawning season (approximately between mid-January and mid-June). Cycle characterization focused on an evaluation of gonadal development and plasma concentrations of several sex steroids and vitellogenin (VTG). Adult largemouth bass (n = 20: 10 females and 10 males) were collected monthly from hatchery ponds for one full calendar year. Plasma samples were analyzed for estradiol-17?? (E2), 11-ketotestosterone (11-KT), testosterone (T), progesterone (P), and VTG. Gonadal tissues were weighed to calculate gonadosomatic index (GSI) and evaluated histologically to characterize reproductive stage. In both sexes, GSI began to increase in November, and peaked in February-March. Increases in gonad weights were correlated with maturation of gonads as evidenced by histological evaluations. Bass exhibited seasonal changes in plasma sex steroids and VTG. In males, 11-KT was the only sex steroid that showed strong seasonality, with highest values in February. In females, although E2 and T concentrations followed a similar annual cycle, with highest and lowest values in February and August, respectively, the strongest pattern was observed with E2. 11-KT concentrations were less variable across months, and values were about half of those observed in males. In females, P peaked two months after E2, with high values still in May and June and decreased thereafter, and VTG began to increase in October, but peaked a month prior to the observed peaked in E2. VTG was also detected in males but at concentrations that were about 1/12 that of females, and no seasonal pattern was evident. This study is the first to fully characterize the seasonal endocrine cycle for largemouth bass. These data will be useful when conducting reproductive evaluations of free </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20180002891&hterms=cycles&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dcycles','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20180002891&hterms=cycles&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dcycles">Hemispheric Differences in the Annual Cycle of Tropical Lower Stratosphere Transport and Tracers</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Tweedy, O. V.; Waugh, D. W.; Stolarski, R. S.; Oman, Luke D.; Randel, W. J.; Abalos, M. 2017-01-01 Transport in the tropical lower stratosphere plays a major role in determining the composition of the entire stratosphere. Previous studies that quantified the relative role of transport processes have generally assumed well-mixed tropics and focused on tropical-�wide average characteristics. However, it has recently been shown that there is a hemispheric difference in the annual cycle of tropical lower stratosphere ozone and other tracers, with a larger amplitude in the northern tropics (NT) than in the southern tropics (ST). In this study, we examined the ability of chemistry climate models (CCMs) to reproduce the hemispheric differences in ozone (O3) and other tracers (i.e., hydrochloric acid, or HCl and nitrous oxide, or N2O), and then use the CCMs to examine the cause of these differences. Examination of CCM simulations from the CCMVal-2 project shows that the majority of the CCMs produce the observed feature of a larger annual cycle in the NT than ST O3 and other tracers. However, only around a third of the models produce an ozone annual cycle similar to that observed. Transformed Eulerian Mean analysis of two of the CCMs shows that seasonality in vertical advection drives the seasonality in ST O3 and N2O while seasonality of horizontal mixing drives the seasonality in NT O3 and N2O, with a large increase in horizontal mixing during northern summer (associated with the Asian monsoon). Thus, latitudinal and longitudinal variations within the tropics have to be considered to fully understand the balance between transport processes in tropical lower stratosphere. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ACP....17.9347C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ACP....17.9347C">Trends and annual cycles in soundings of Arctic tropospheric ozone</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Christiansen, Bo; Jepsen, Nis; Kivi, Rigel; Hansen, Georg; Larsen, Niels; Smith Korsholm, Ulrik 2017-08-01 Ozone soundings from nine Nordic stations have been homogenized and interpolated to standard pressure levels. The different stations have very different data coverage; the longest period with data is from the end of the 1980s to 2014. At each pressure level the homogenized ozone time series have been analysed with a model that includes both low-frequency variability in the form of a polynomial, an annual cycle with harmonics, the possibility for low-frequency variability in the annual amplitude and phasing, and either white noise or noise given by a first-order autoregressive process. The fitting of the parameters is performed with a Bayesian approach not only giving the mean values but also confidence intervals. The results show that all stations agree on a well-defined annual cycle in the free troposphere with a relatively confined maximum in the early summer. Regarding the low-frequency variability, it is found that Scoresbysund, Ny Ålesund, Sodankylä, Eureka, and Ørland show similar, significant signals with a maximum near 2005 followed by a decrease. This change is characteristic for all pressure levels in the free troposphere. A significant change in the annual cycle was found for Ny Ålesund, Scoresbysund, and Sodankylä. The changes at these stations are in agreement with the interpretation that the early summer maximum is appearing earlier in the year. The results are shown to be robust to the different settings of the model parameters such as the order of the polynomial, number of harmonics in the annual cycle, and the type of noise. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70168686','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70168686">A full annual cycle modeling framework for American black ducks</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Robinson, Orin J.; McGowan, Conor P.; Devers, Patrick K.; Brook, Rodney W.; Huang, Min; Jones, Malcom; McAuley, Daniel G.; Zimmerman, Guthrie S. 2016-01-01 American black ducks (Anas rubripes) are a harvested, international migratory waterfowl species in eastern North America. Despite an extended period of restrictive harvest regulations, the black duck population is still below the population goal identified in the North American Waterfowl Management Plan (NAWMP). It has been hypothesized that density-dependent factors restrict population growth in the black duck population and that habitat management (increases, improvements, etc.) may be a key component of growing black duck populations and reaching the prescribed NAWMP population goal. Using banding data from 1951 to 2011 and breeding population survey data from 1990 to 2014, we developed a full annual cycle population model for the American black duck. This model uses the seven management units as set by the Black Duck Joint Venture, allows movement into and out of each unit during each season, and models survival and fecundity for each region separately. We compare model population trajectories with observed population data and abundance estimates from the breeding season counts to show the accuracy of this full annual cycle model. With this model, we then show how to simulate the effects of habitat management on the continental black duck population. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GBioC..30..175W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GBioC..30..175W">Annual cycles of phytoplankton biomass in the subarctic Atlantic and Pacific Ocean</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Westberry, Toby K.; Schultz, Patrick; Behrenfeld, Michael J.; Dunne, John P.; Hiscock, Michael R.; Maritorena, Stephane; Sarmiento, Jorge L.; Siegel, David A. 2016-02-01 High-latitude phytoplankton blooms support productive fisheries and play an important role in oceanic uptake of atmospheric carbon dioxide. In the subarctic North Atlantic Ocean, blooms are a recurrent feature each year, while in the eastern subarctic Pacific only small changes in chlorophyll (Chl) are seen over the annual cycle. Here we show that when evaluated using phytoplankton carbon biomass (Cphyto) rather than Chl, an annual bloom in the North Pacific is evident and can even rival blooms observed in the North Atlantic. The annual increase in subarctic Pacific phytoplankton biomass is not readily observed in the Chl record because it is paralleled by light- and nutrient-driven decreases in cellular pigment levels (Cphyto:Chl). Specifically, photoacclimation and iron stress effects on Cphyto:Chl oppose the biomass increase, leading to only modest changes in bulk Chl. The magnitude of the photoacclimation effect is quantified using descriptors of the near-surface light environment and a photophysiological model. Iron stress effects are diagnosed from satellite chlorophyll fluorescence data. Lastly, we show that biomass accumulation in the Pacific is slower than that in the Atlantic but is closely tied to similar levels of seasonal nutrient uptake in both basins. Annual cycles of satellite-derived Chl and Cphyto are reproduced by in situ autonomous profiling floats. These results contradict the long-standing paradigm that environmental conditions prevent phytoplankton accumulation in the subarctic Northeast Pacific and suggest a greater seasonal decoupling between phytoplankton growth and losses than traditionally implied. Further, our results highlight the role of physiological processes in shaping bulk properties, such as Chl, and their interpretation in studies of ocean ecosystem dynamics and climate change. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/1409900','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/1409900">Wrist activity in a woman: daily, weekly, menstrual, lunar, annual cycles?</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Binkley, S 1992-09-01 Wrist activity was monitored continuously for one year in a woman who went about her normal life. The year of data were analyzed for changes and rhythms--daily, weekly, menstrual, lunar, annual. For each day, average motions/5 minutes, activity onset, activity offset, alpha (duration of activity), and acrophase were measured. Periodograms and average daily wave forms were calculated. Well-defined, entrained, daily rest-activity cycles were observed throughout the year with periods close to 24 hours. There was weekend delay (0.7 hours) in onset, weekend decrease in alpha (1.0 hours), and weekend advance of acrophase (0.4 hours). Motions/5 minutes decreased 9%, onsets were 0.3 hours later, and alphas were 0.4 hours shorter on menstrual cycle days 8 through 18 which should have encompassed the time of ovulation. Lunar phase had no effect. Annual changes in onset (1.1 hours), offset (1.2 hours), and acrophase (1.1 hours) were attributed to the 1-hour change between standard and daylight savings time. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70178522','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70178522">Disentangling density-dependent dynamics using full annual cycle models and Bayesian model weight updating</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Robinson, Orin J.; McGowan, Conor P.; Devers, Patrick K. 2017-01-01 Density dependence regulates populations of many species across all taxonomic groups. Understanding density dependence is vital for predicting the effects of climate, habitat loss and/or management actions on wild populations. Migratory species likely experience seasonal changes in the relative influence of density dependence on population processes such as survival and recruitment throughout the annual cycle. These effects must be accounted for when characterizing migratory populations via population models.To evaluate effects of density on seasonal survival and recruitment of a migratory species, we used an existing full annual cycle model framework for American black ducks Anas rubripes, and tested different density effects (including no effects) on survival and recruitment. We then used a Bayesian model weight updating routine to determine which population model best fit observed breeding population survey data between 1990 and 2014.The models that best fit the survey data suggested that survival and recruitment were affected by density dependence and that density effects were stronger on adult survival during the breeding season than during the non-breeding season.Analysis also suggests that regulation of survival and recruitment by density varied over time. Our results showed that different characterizations of density regulations changed every 8–12 years (three times in the 25-year period) for our population.Synthesis and applications. Using a full annual cycle, modelling framework and model weighting routine will be helpful in evaluating density dependence for migratory species in both the short and long term. We used this method to disentangle the seasonal effects of density on the continental American black duck population which will allow managers to better evaluate the effects of habitat loss and potential habitat management actions throughout the annual cycle. The method here may allow researchers to hone in on the proper form and/or strength of </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70186025','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70186025">Full annual cycle climate change vulnerability assessment for migratory birds</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Culp, Leah A.; Cohen, Emily B.; Scarpignato, Amy L.; Thogmartin, Wayne E.; Marra, Peter P. 2017-01-01 Climate change is a serious challenge faced by all plant and animal species. Climate change vulnerability assessments (CCVAs) are one method to assess risk and are increasingly used as a tool to inform management plans. Migratory animals move across regions and continents during their annual cycles where they are exposed to diverse climatic conditions. Climate change during any period and in any region of the annual cycle could influence survival, reproduction, or the cues used to optimize timing of migration. Therefore, CCVAs for migratory animals best estimate risk when they include climate exposure during the entire annual cycle. We developed a CCVA incorporating the full annual cycle and applied this method to 46 species of migratory birds breeding in the Upper Midwest and Great Lakes (UMGL) region of the United States. Our methodology included background risk, climate change exposure × climate sensitivity, adaptive capacity to climate change, and indirect effects of climate change. We compiled information about migratory connectivity between breeding and stationary non-breeding areas using literature searches and U.S. Geological Survey banding and re-encounter data. Climate change exposure (temperature and moisture) was assessed using UMGL breeding season climate and winter climate from non-breeding regions for each species. Where possible, we focused on non-breeding regions known to be linked through migratory connectivity. We ranked 10 species as highly vulnerable to climate change and two as having low vulnerability. The remaining 34 species were ranked as moderately vulnerable. In general, including non-breeding data provided more robust results that were highly individualistic by species. Two species were found to be highly vulnerable throughout their annual cycle. Projected drying will have the greatest effect during the non-breeding season for species overwintering in Mexico and the Caribbean. Projected temperature increases will have the greatest </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19740026681','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19740026681">A note on the annual cycles of surface heat balance and temperature over a continent. [North America</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Spar, J.; Crane, G. 1974-01-01 A surface heating function, defined as the ratio of the time derivative of the mean annual temperature curve to the surface heat balance, is computed from the annual temperature range and heat balance data for the North American continent. An annual cycle of the surface heat balance is then reconstructed from the surface heating function and the annual temperature curve, and an annual cycle of evaporative plus turbulent heat loss is recomputed from the annual cycles of radiation balance and surface heat balance for the continent. The implications of these results for long range weather forecasting are discussed. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMOS33A1812H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMOS33A1812H">Ocean Color and the Equatorial Annual Cycle in the Pacific</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Hammann, A. C.; Gnanadesikan, A. 2012-12-01 The presence of chlorophyll, colored dissolved organic matter (CDOM) and other scatterers in ocean surface waters affect the flux divergence of solar radiation and thus the vertical distribution of radiant heating of the ocean. While this may directly alter the local mixed-layer depth and temperature (Martin 1985; Strutton & Chavez 2004), non-local changes are propagated through advection (Manizza et al. 2005; Murtugudde et al. 2002; Nakamoto et al. 2001; Sweeny et al. 2005). In and coupled feedbacks (Lengaigne et al. 2007; Marzeion & Timmermann 2005). Anderson et al. (2007), Anderson et al. (2009) and Gnanadesikan & Anderson (2009) have performed a series of experiments with a fully coupled climate model which parameterizes the e-folding depth of solar irradiance in terms of surface chlorophyll-a concentration. The results have so far been discussed with respect to the climatic mean state and ENSO variability in the tropical Pacific. We extend the discussion here to the Pacific equatorial annual cycle. The focus of the coupled experiments has been the sensitivity of the coupled system to regional differences in chlorophyll concentration. While runs have been completed with realistic SeaWiFS-derived monthly composite chlorophyll ('green') and with a globally chlorophyll-free ocean ('blue'), the concentrations in two additional runs have been selectively set to zero in specific regions: the oligotrophic subtropical gyres ('gyre') in one case and the mesotrophic gyre margins ('margin') in the other. The annual cycle of ocean temperatures exhibits distinctly reduced amplitudes in the 'blue' and 'margin' experiments, and a slight reduction in 'gyre' (while ENSO variability almost vanishes in 'blue' and 'gyre', but amplifies in 'margin' - thus the frequently quoted inverse correlation between ENSO and annual amplitudes holds only for the 'green' / 'margin' comparison). It is well-known that on annual time scales, the anomalous divergence of surface currents and vertical </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020020177','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020020177">The Annual Cycle of Water Vapor on Mars as Observed by the Thermal Emission Spectrometer</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Smith, Michael D.; Vondrak, Richard R. (Technical Monitor) 2001-01-01 Spectra taken by the Mars Global Surveyor Thermal Emission Spectrometer (TES) have been used to monitor the latitude, longitude, and seasonal dependence of water vapor for over one full Martian year (March 1999-March 2001). A maximum in water vapor abundance is observed at high latitudes during mid-summer in both hemispheres, reaching a maximum value of approximately 100 pr-micrometer in the north and approximately 50 pr-micrometer in the south. Low water vapor abundance (<5 pr-micrometer) is observed at middle and high latitudes in the fall and winter of both hemispheres. There are large differences in the hemispheric (north versus south) and seasonal (perihelion versus aphelion) behavior of water vapor. The latitudinal and seasonal dependence of the decay of the northern summer water vapor maximum implies cross-equatorial transport of water to the southern hemisphere, while there is little or no corresponding transport during the decay of the southern hemisphere summer maximum. The latitude-longitude dependence of annually-averaged water vapor (corrected for topography) has a significant positive correlation with albedo and significant negative correlations with thermal inertia and surface pressure. Comparison of TES results with those retrieved from the Viking Orbiter Mars Atmospheric Water Detectors (MAWD) experiments shows some similar features, but also many significant differences. The southern hemisphere maximum observed by TES was not observed by MAWD and the large latitudinal gradient in annually-averaged water vapor observed by MAWD does not appear in the TES results. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/10893170','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/10893170">Relationships between annual cycles of testosterone, corticosterone, and body condition in male red-spotted garter snakes, Thamnophis sirtalis concinnus.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Moore, I T; Lerner, J P; Lerner, D T; Mason, R T 2000-01-01 Over a 2-yr period, we investigated the annual cycles of plasma testosterone and corticosterone and the relationships between these hormones and body condition in a wild population of male red-spotted garter snakes, Thamnophis sirtalis concinnus. In the 10 mo that were sampled, a peak in testosterone was observed in late summer during gametogenesis and declining through the spring breeding period. Corticosterone and testosterone cycles were positively correlated, in contrast to many vertebrates, suggesting the lack of a direct negative interaction between the two hormones. Body condition, defined as the residual of the regression of mass on snout-vent length, also cycled annually, with individuals being more robust during the summer than during the spring or fall. Individuals with a positive body condition had significantly lower plasma levels of corticosterone than did individuals with a negative body condition, supporting the energetic role of glucocorticoids. There was no relationship between body condition and testosterone. This study suggests that annual cycles of testosterone, corticosterone, and body condition can be associated with one another, and considering all three simultaneously is necessary to understand their control and function. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150000779','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150000779">Global Sea Ice Coverage from Satellite Data: Annual Cycle and 35-Year Trends</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Parkinson, Claire L. 2014-01-01 Well-established satellite-derived Arctic and Antarctic sea ice extents are combined to create the global picture of sea ice extents and their changes over the 35-yr period 1979-2013. Results yield a global annual sea ice cycle more in line with the high-amplitude Antarctic annual cycle than the lower-amplitude Arctic annual cycle but trends more in line with the high-magnitude negative Arctic trends than the lower-magnitude positive Antarctic trends. Globally, monthly sea ice extent reaches a minimum in February and a maximum generally in October or November. All 12 months show negative trends over the 35-yr period, with the largest magnitude monthly trend being the September trend, at -68,200 +/- 10,500 sq km/yr (-2.62% 6 +/- 0.40%/decade), and the yearly average trend being -35,000 +/- 5900 sq km/yr (-1.47% +/- 0.25%/decade). </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150021289','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150021289">Global Sea Ice Coverage from Satellite Data: Annual Cycle and 35-Yr Trends</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Parkinson, Claire L. 2014-01-01 Well-established satellite-derived Arctic and Antarctic sea ice extents are combined to create the global picture of sea ice extents and their changes over the 35-yr period 1979-2013. Results yield a global annual sea ice cycle more in line with the high-amplitude Antarctic annual cycle than the lower-amplitude Arctic annual cycle but trends more in line with the high-magnitude negative Arctic trends than the lower-magnitude positive Antarctic trends. Globally, monthly sea ice extent reaches a minimum in February and a maximum generally in October or November. All 12 months show negative trends over the 35-yr period, with the largest magnitude monthly trend being the September trend, at -68200 +/- 10500 km sq yr(exp -1) (-2.62% +/- 0.40%decade(exp -1)), and the yearly average trend being -35000 +/-5900 km sq yr(exp -1) (-1.47% +/- 0.25%decade(exp -1)). </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70190502','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70190502">Survivorship across the annual cycle of a migratory passerine, the willow flycatcher</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Paxton, Eben H.; Durst, Scott L.; Sogge, Mark K.; Koronkiewicz, Thomas J.; Paxton, Kristina L. 2017-01-01 Annual survivorship in migratory birds is a product of survival across the different periods of the annual cycle (i.e. breeding, wintering, and migration), and may vary substantially among these periods. Determining which periods have the highest mortality, and thus are potentially limiting a population, is important especially for species of conservation concern. To estimate survival probabilities of the willow flycatcher Empidonax traillii in each of the different periods, we combined demographic data from a 10-year breeding season study with that from a 5-year wintering grounds study. Estimates of annual apparent survival for breeding and wintering periods were nearly identical (65–66%), as were estimates of monthly apparent survival for both breeding and wintering stationary periods (98–99%). Because flycatchers spend at least half the year on the wintering grounds, overall apparent survivorship was lower (88%) on the wintering grounds than on the breeding grounds (97%). The migratory period had the highest mortality rate, accounting for 62% of the estimated annual mortality even though it comprises only one quarter or less of the annual cycle. The migratory period in the willow flycatcher and many other neotropical migrants is poorly understood, and further research is needed to identify sources of mortality during this crucial period. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1511435F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1511435F">Changes in the Amplitude and Phase of the Annual Cycle: quantifying from surface wind series in China</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Feng, Tao 2013-04-01 Climate change is not only reflected in the changes in annual means of climate variables but also in the changes in their annual cycles (seasonality), especially in the regions outside the tropics. Changes in the timing of seasons, especially the wind season, have gained much attention worldwide in recent decade or so. We introduce long-range correlated surrogate data to Ensemble Empirical Mode Decomposition method, which represent the statistic characteristics of data better than white noise. The new method we named Ensemble Empirical Mode Decomposition with Long-range Correlated noise (EEMD-LRC) and applied to 600 station wind speed records. This new method is applied to investigate the trend in the amplitude of the annual cycle of China's daily mean surface wind speed for the period 1971-2005. The amplitude of seasonal variation decrease significantly in the past half century over China, which can be well explained by Annual Cycle component from EEMD-LRC. Furthermore, the phase change of annual cycle lead to strongly shorten of wind season in spring, and corresponding with strong windy day frequency change over Northern China. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050180258','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050180258">Wave-driven Equatorial Annual Oscillation Induced and Modulated by the Solar Cycle</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Mayr, Hans G.; Mengel, John G.; Wolff, Charles 2005-01-01 Our model for the solar cycle (SC) modulation of the Quasi-Biennial Oscillation (QBO) produces a hemispherically symmetric 12-month Annual Oscillation (AO) in the zonal winds, which is confined to low latitudes. This Equatorial Annual Oscillation (EAO) is produced by interaction between the anti-symmetric component of SC forcing and the dominant anti-symmetric AO. The EA0 is amplified by the upward propagating small- scale gravity waves (GW), and the oscillation propagates down through the stratosphere like the QBO. The amplitude of the EA0 is relatively small, but its SC modulation contributes significantly to extend the effect to lower altitudes. Although the energy of the EA0 is concentrated at low latitudes, prominent signatures appear in the Polar Regions where the SC produces measurable temperature variations. At lower altitudes, the SC effects are significantly different in the two hemispheres because of the EAO, and due to its GW driven downward propagation the phase of the annual cycle is delayed. </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li class="active">2</li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_3" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li class="active">3</li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="41"> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20060013182&hterms=Sam+south&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DSam%2Bsouth','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20060013182&hterms=Sam+south&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DSam%2Bsouth">Characterizing diurnal and seasonal cycles in monsoon systems from TRMM and CEOP observations</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Lau, William K. M. 2006-01-01 The CEOP Inter-Monsoon Study (CIMS) is one of the two main science drivers of CEOP that aims to (a) provide better understanding of fundamental physical processes in monsoon regions around the world, and (b) demonstrate the synergy and utility of CEOP data in providing a pathway for model physics evaluation and improvement. As the data collection phase for EOP-3 and EOP-4 is being completed, two full annual cycles (2003-2004) of research-quality data sets from satellites, reference sites, and model output location time series (MOLTS) have been processed and made available for data analyses and model validation studies. This article presents preliminary results of a CIMS study aimed at the characterization and intercomparison of all major monsoon systems. The CEOP reference site data proved its value in such exercises by being a powerful tool to cross-validate the TRMM data, and to intercompare with multi-model results in ongoing work. We use 6 years (1998-2003) of pentad CEOP/TRMM data with 2deg x 2.5deg latitude-longitude grid, over the domain of interests to define the monsoon climatological diurnal and annual cycles for the East Asian Monsoon (EAM), the South Asian Monsoon (SAM), the West Africa Monsoon (WAM), the North America/Mexican Monsoon (NAM), the South American Summer Monsoon (SASM) and the Australian Monsoon (AUM). As noted, the TRMM data used in the study were cross-validated using CEOP reference site data, where applicable. Results show that the observed diurnal cycle of rain peaked around late afternoon over monsoon land, and early morning over the oceans. The diurnal cycles in models tend to peak 2-3 hours earlier than observed. The seasonal cycles of the EAM and SAM show the strongest continentality, i.e, strong control by continental processes away from the ITCZ. The WAM, and the AUM shows the less continentality, i.e, strong control by the oceanic ITCZ. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20070010576&hterms=Sam+south&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DSam%2Bsouth','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20070010576&hterms=Sam+south&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DSam%2Bsouth">Characterizing Diurnal and Seasonal Cycles in Monsoon Systems from TRMM and CEOP Observations</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Lau, William K. M. 2007-01-01 The CEOP Inter-Monsoon Study (CIMS) is one of the two main science drivers of CEOP that aims to (a) provide better understanding of fundamental physical processes in monsoon regions around the world, and (b) demonstrate the synergy and utility of CEOP data in providing a pathway for model physics evaluation and improvement. As the data collection phase for EOP-3 and EOP-4 is being completed, two full annual cycles (2003-2004) of research-quality data sets from satellites, reference sites, and model output location time series (MOLTS) have been processed and made available for data analyses and model validation studies. This article presents preliminary results of a CIMS study aimed at the characterization and intercomparison of all major monsoon systems. The CEOP reference site data proved its value in such exercises by being a powerful tool to cross-validate the TRMM data, and to intercompare with multi-model results in ongoing work. We use 6 years (1998-2003) of pentad CEOP/TRMM data with 2 deg x 2.5 deg. latitude-longitude grid, over the domain of interests to define the monsoon climatological diurnal and annual cycles for the East Asian Monsoon (EAM), the South Asian Monsoon (SAM), the West Africa Monsoon (WAM), the North America/Mexican Monsoon (NAM), the South American Summer Monsoon (SASM) and the Australian Monsoon (AUM). As noted, the TRMM data used in the study were cross-validated using CEOP reference site data, where applicable. Results show that the observed diurnal cycle of rain peaked around late afternoon over monsoon land, and early morning over the oceans. The diurnal cycles in models tend to peak 2-3 hours earlier than observed. The seasonal cycles of the EAM and SAM show the strongest continentality, i.e, strong control by continental processes away from the ITCZ. The WAM, and the AUM shows the less continentality, i.e, strong control by the oceanic ITCZ. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.5307C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.5307C">Annual, semi-annual and ter-annual variations of gravity wave momentum flux in 13 years of SABER data</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Chen, Dan; Preusse, Peter; Ern, Manfred; Strube, Cornelia 2017-04-01 In this study, the variations at different time scales such as the annual cycle, the semiannual oscillation (SAO), the ter-annual cycle (about four monthly) and the quasi-biennial oscillation (QBO) in zonal mean GW amplitudes and GW momentum flux (GWMF) have been investigated using satellite observations from 2002-2014 and combining ECMWF high resolution data with the GORGRAT model. The global distribution (patterns) of spectral amplitudes of GW momentum flux in stratosphere and mesosphere (from 30 km to 90 km) show that the annual cycle is the most predominant variation, and then are SAO, ter-annual cycle and QBO. For annual components, two relatively isolated amplitude maxima appear in each hemisphere: a subtropical maximum is associated with convective sources in summer, a mid and high latitude maximum is associated with the polar vortex in winter. In the subtropics, GWs propagate upward obliquely to the higher latitudes. The winter maximum in the southern hemisphere has larger momentum flux than that one in the northern hemisphere. While on the SH the phase (i.e. time corresponding to the maximum GWMF) continuously descends with the maximum in July in the upper mesosphere and in September in the lower stratosphere, on the northern hemisphere, the phase has no visible altitude dependence with a maximum in December. For semiannual variations, in the MLT (70-80 km) region, there is an obvious enhancement of spectral amplitude at equatorial latitudes which relate to the dissipation of convectively forced GWs. The SAO in absolute momentum flux and the annual cycle in zonal momentum flux indicated that the variations at mid-latitudes (about from 30°-40°) are not a SAO signals but rather an annual cycle when the direction of GWMF is considered. The ter-annual cycle may be related to the duration of active convection in subtropical latitudes (from June to Sep. in north hemisphere) Indications for QBO are found latitude extension to mid-latitudes in stratosphere of </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2788620','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2788620">Tropical Mosquito Assemblages Demonstrate ‘Textbook’ Annual Cycles</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> Franklin, Donald C.; Whelan, Peter I. 2009-01-01 Background Annual biological rhythms are often depicted as predictably cyclic, but quantitative evaluations are few and rarely both cyclic and constant among years. In the monsoon tropics, the intense seasonality of rainfall frequently drives fluctuations in the populations of short-lived aquatic organisms. However, it is unclear how predictably assemblage composition will fluctuate because the intensity, onset and cessation of the wet season varies greatly among years. Methodology/Principal Findings Adult mosquitoes were sampled using EVS suction traps baited with carbon dioxide around swamplands adjacent to the city of Darwin in northern Australia. Eleven sites were sampled weekly for five years, and one site weekly for 24 years, the sample of c. 1.4 million mosquitoes yielding 63 species. Mosquito abundance, species richness and diversity fluctuated seasonally, species richness being highly predictable. Ordination of assemblage composition demonstrated striking annual cycles that varied little from year to year. The mosquito assemblage was temporally structured by a succession of species peaks in abundance. Conclusion/Significance Ordination provided strong visual representation of annual rhythms in assemblage composition and the means to evaluate variability among years. Because most mosquitoes breed in shallow freshwater which fluctuates with rainfall, we did not anticipate such repeatability; we conclude that mosquito assemblage composition appears adapted to predictable elements of the rainfall. PMID:20011531 </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27558737','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27558737">Spatial variations in annual cycles of body-size spectra of planktonic ciliates and their environmental drivers in marine ecosystems.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Xu, Henglong; Jiang, Yong; Xu, Guangjian 2016-11-15 Body-size spectra has proved to be a useful taxon-free resolution to summarize a community structure for bioassessment. The spatial variations in annual cycles of body-size spectra of planktonic ciliates and their environmental drivers were studied based on an annual dataset. Samples were biweekly collected at five stations in a bay of the Yellow Sea, northern China during a 1-year cycle. Based on a multivariate approach, the second-stage analysis, it was shown that the annual cycles of the body-size spectra were significantly different among five sampling stations. Correlation analysis demonstrated that the spatial variations in the body-size spectra were significantly related to changes of environmental conditions, especially dissolved nitrogen, alone or in combination with salinity and dissolve oxygen. Based on results, it is suggested that the nutrients may be the environmental drivers to shape the spatial variations in annual cycles of planktonic ciliates in terms of body-size spectra in marine ecosystems. Copyright © 2016 Elsevier Ltd. All rights reserved. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040026734&hterms=water+cycles&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dwater%2Bcycles','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040026734&hterms=water+cycles&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dwater%2Bcycles">Observing the Global Water Cycle from Space</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Hildebrand, Peter H.; Houser, Paul; Schlosser, C. Adam 2003-01-01 This paper presents an approach to measuring all major components of the water cycle from space. The goal of the paper is to explore the concept of using a sensor-web of satellites to observe the global water cycle. The details of the required measurements and observation systems are therefore only an initial approach and will undergo future refinement, as their details will be highly important. Key elements include observation and evaluation of all components of the water cycle in terms of the storage of water-in the ocean, air, cloud and precipitation, in soil, ground water, snow and ice, and in lakes and rivers-and in terms of the global fluxes of water between these reservoirs. For each component of the water cycle that must be observed, the appropriate temporal and spatial scales of measurement are estimated, along with the some of the frequencies that have been used for active and passive microwave observations of the quantities. The suggested types of microwave observations are based on the heritage for such measurements, and some aspects of the recent heritage of these measurement algorithms are listed. The observational requirements are based on present observational systems, as modified by expectations for future needs. Approaches to the development of space systems for measuring the global water cycle can be based on these observational requirements. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20060040928&hterms=greenhouse&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dgreenhouse','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20060040928&hterms=greenhouse&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dgreenhouse">Influence of Sea Surface Temperature, Tropospheric Humidity and Lapse Rate on the Annual Cycle of the Clear-Sky Greenhouse Effect</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Hu, H.; Liu, W. 2000-01-01 The implication of this work will provide modeling study a surrogate of annual cycle of the greenhouse effect. For example, the model should be able to simulate the annual cycle before it can be used for global change study. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20050070876&hterms=water+cycles&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dwater%2Bcycles','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20050070876&hterms=water+cycles&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dwater%2Bcycles">Observing the Global Water Cycle from Space</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Hildebrand, P. H. 2004-01-01 This paper presents an approach to measuring all major components of the water cycle from space. Key elements of the global water cycle are discussed in terms of the storage of water-in the ocean, air, cloud and precipitation, in soil, ground water, snow and ice, and in lakes and rivers, and in terms of the global fluxes of water between these reservoirs. Approaches to measuring or otherwise evaluating the global water cycle are presented, and the limitations on known accuracy for many components of the water cycle are discussed, as are the characteristic spatial and temporal scales of the different water cycle components. Using these observational requirements for a global water cycle observing system, an approach to measuring the global water cycle from space is developed. The capabilities of various active and passive microwave instruments are discussed, as is the potential of supporting measurements from other sources. Examples of space observational systems, including TRMM/GPM precipitation measurement, cloud radars, soil moisture, sea surface salinity, temperature and humidity profiling, other measurement approaches and assimilation of the microwave and other data into interpretative computer models are discussed to develop the observational possibilities. The selection of orbits is then addressed, for orbit selection and antenna size/beamwidth considerations determine the sampling characteristics for satellite measurement systems. These considerations dictate a particular set of measurement possibilities, which are then matched to the observational sampling requirements based on the science. The results define a network of satellite instrumentation systems, many in low Earth orbit, a few in geostationary orbit, and all tied together through a sampling network that feeds the observations into a data-assimilative computer model. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ClDy...49.3923C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ClDy...49.3923C">Dynamical diagnostics of the SST annual cycle in the eastern equatorial Pacific: Part II analysis of CMIP5 simulations</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Chen, Ying-Ying; Jin, Fei-Fei 2017-12-01 In this study, a simple coupled framework established in Part I is utilized to investigate inter-model diversity in simulating the equatorial Pacific SST annual cycle (SSTAC). It demonstrates that the simulated amplitude and phase characteristics of SSTAC in models are controlled by two internal dynamical factors (the damping rate and phase speed) and two external forcing factors (the strength of the annual and semi-annual harmonic forcing). These four diagnostic factors are further condensed into a dynamical response factor and a forcing factor to derive theoretical solutions of amplitude and phase of SSTAC. The theoretical solutions are in remarkable agreement with observations and CMIP5 simulations. The great diversity in the simulated SSTACs is related to the spreads in these dynamic and forcing factors. Most models tend to simulate a weak SSTAC, due to their weak damping rate and annual harmonic forcing. The latter is due to bias in the meridional asymmetry of the annual mean state of the tropical Pacific, represented by the weak cross-equatorial winds in the cold tongue region. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ClDy...50.1841C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ClDy...50.1841C">Dynamical diagnostics of the SST annual cycle in the eastern equatorial Pacific: part I a linear coupled framework</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Chen, Ying-Ying; Jin, Fei-Fei 2018-03-01 The eastern equatorial Pacific has a pronounced westward propagating SST annual cycle resulting from ocean-atmosphere interactions with equatorial semiannual solar forcing and off-equatorial annual solar forcing conveyed to the equator. In this two-part paper, a simple linear coupled framework is proposed to quantify the internal dynamics and external forcing for a better understanding of the linear part of the dynamics annual cycle. It is shown that an essential internal dynamical factor is the SST damping rate which measures the coupled stability in a similar way as the Bjerknes instability index for the El Niño-Southern Oscillation. It comprises three major negative terms (dynamic damping due to the Ekman pumping feedback, mean circulation advection, and thermodynamic feedback) and two positive terms (thermocline feedback and zonal advection). Another dynamical factor is the westward-propagation speed that is mainly determined by the thermodynamic feedback, the Ekman pumping feedback, and the mean circulation. The external forcing is measured by the annual and semiannual forcing factors. These linear internal and external factors, which can be estimated from data, determine the amplitude of the annual cycle. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013GPC...100..129L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013GPC...100..129L">Evolution of the El Nino-Southern Oscillation in the late Holocene and insolation driven change in the tropical annual SST cycle</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Loubere, Paul; Creamer, Winifred; Haas, Jonathan 2013-01-01 South American lake sediment records indicate that El Nino events in the eastern equatorial Pacific (EEP) became more frequent after 3000 calendar years BP. The reason for this evolution of ENSO behavior remains in question. An important trigger for ocean-atmosphere state switching in the tropical ocean is the annual cycle of sea surface temperature south of the equator along the margin of South America. This annual cycle can be reconstructed from the oxygen isotope records of the surf clam Mesodesma donacium. We provide evidence that these isotope records, as preserved in archeological deposits in coastal central Peru, reflect seasonal paleo-SST. We find that the annual SST cycle in the eastern equatorial Pacific became larger over the 4500-2500 calendar year BP interval. This is consistent with increased ENSO variability. The magnification of the annual SST cycle can be attributed to changing insolation, indicating that ENSO is sensitive to the intensity and seasonal timing of solar heating of the southern EEP. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JASTP.171..241L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JASTP.171..241L">Climatology and inter-annual variability of the polar mesospheric winds inferred from meteor radar observations over Sodankylä (67N, 26E) during solar cycle 24</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Lukianova, Renata; Kozlovsky, Alexander; Lester, Mark 2018-06-01 The inter-annual variability, climatological mean wind and tide fields in the northern polar mesosphere/lower thermosphere region of 82-98 km height are studied using observations by the meteor radar which has operated continuously during solar cycle 24 (from December 2008 onward) at the Sodankylä Geophysical Observatory (67N, 26E). Summer mean zonal winds are characterized by westward flow, up to 25 m/s, at lower heights and eastward flow, up to 30 m/s, at upper heights. In the winter an eastward flow, up to 10 m/s, dominates at all heights. The meridional winds are characterized by a relatively weak poleward flow (few m/s) in the winter and equatorward flow in the summer, with a jet core (∼15 m/s) located slightly below 90 km. These systematically varying winds are dominated by the semidiurnal tides. The largest amplitudes, up to 30 m/s, are observed at higher altitudes in winter and a secondary maximum is seen in August-September. The diurnal tides are almost a factor of two weaker and peak in summer. The variability of individual years is dominated by the winter perturbations. During the period of observations major sudden stratospheric warmings (SSW) occurred in January 2009 and 2013. During these events the wind fields were strongly modified. The lowest altitude eastward winds maximized up to 25 m/s, that is by more twice that of the non-SSW years. The poleward flow considerably increases (up 10 m/s) and extends from the lower heights throughout the whole altitude range. The annual pattern in temperature at ∼90 km height over Sodankyla consists of warm winters (up to 200 K) and cold summers (∼120 K). </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20070034026&hterms=coverage&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dcoverage','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20070034026&hterms=coverage&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dcoverage">Annual Cycles of Multiyear Sea Ice Coverage of the Arctic Ocean: 1999-2003</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Kwok, R. 2004-01-01 For the years 1999-2003, we estimate the time-varying perennial ice zone (PIZ) coverage and construct the annual cycles of multiyear (MY, including second year) ice coverage of the Arctic Ocean using QuikSCAT backscatter, MY fractions from RADARSAT, and the record of ice export from satellite passive microwave observations. An area balance approach extends the winter MY coverage from QuikSCAT to the remainder of the year. From these estimates, the coverage of MY ice at the beginning of each year is 3774 x 10(exp 3) sq km (2000), 3896 x 10(exp 3) sq km (2001), 4475 x 10(exp 3) sq km (2002), and 4122 x 10(exp 3) sq km (2003). Uncertainties in coverage are approx.150 x 10(exp 3) sq km. In the mean, on 1 January, MY ice covers approx.60% of the Arctic Ocean. Ice export reduces this coverage to approx.55% by 1 May. From the multiple annual cycles, the area of first-year (FY) ice that survives the intervening summers are 1192 x 10(exp 3) sq km (2000), 1509 x 10(exp 3) sq km (2001), and 582 x 10(exp 3) sq km (2002). In order for the MY coverage to remain constant from year to year, these replenishment areas must balance the overall area export and melt during the summer. The effect of the record minimum in Arctic sea ice area during the summer of 2002 is seen in the lowest area of surviving FY ice of the three summers. In addition to the spatial coverage, the location of the PIZ is important. One consequence of the unusual location of the PIZ at the end of the summer of 2002 is the preconditioning for enhanced export of MY ice into the Barents and Kara seas. Differences between the minimums in summer sea ice coverage from our estimates and passive microwave observations are discussed. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20130004326','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20130004326">The Martian Dust Cycle: Observations and Modeling</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Kahre, Melinda A. 2013-01-01 The dust cycle is critically important for Mars' current climate system. Suspended atmospheric dust affects the radiative balance of the atmosphere, and thus greatly influences the thermal and dynamical state of the atmosphere. Evidence for the presence of dust in the Martian atmosphere can be traced back to yellow clouds telescopically observed as early as the early 19th century. The Mariner 9 orbiter arrived at Mars in November of 1971 to find a planet completely enshrouded in airborne dust. Since that time, the exchange of dust between the planet's surface and atmosphere and the role of airborne dust on Mars' weather and climate has been studied using observations and numerical models. The goal of this talk is to give an overview of the observations and to discuss the successes and challenges associated with modeling the dust cycle. Dust raising events on Mars range in size from meters to hundreds of kilometers. During some years, regional storms merge to produce hemispheric or planet encircling dust clouds that obscure the surface and raise atmospheric temperatures by tens of kelvin. The interannual variability of planet encircling dust storms is poorly understood. Although the occurrence and season of large regional and global dust storms are highly variable from one year to the next, there are many features of the dust cycle that occur year after year. A low-level dust haze is maintained during northern spring and summer, while elevated levels of atmospheric dust occur during northern autumn and winter. During years without global-scale dust storms, two peaks in total dust loading are generally observed: one peak occurs before northern winter solstice and one peak occurs after northern winter solstice. Numerical modeling studies attempting to interactively simulate the Martian dust cycle with general circulation models (GCMs) include the lifting, transport, and sedimentation of radiatively active dust. Two dust lifting processes are commonly represented in </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28878971','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28878971">Hovering hummingbird wing aerodynamics during the annual cycle. I. Complete wing.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Achache, Yonathan; Sapir, Nir; Elimelech, Yossef 2017-08-01 The diverse hummingbird family (Trochilidae) has unique adaptations for nectarivory, among which is the ability to sustain hover-feeding. As hummingbirds mainly feed while hovering, it is crucial to maintain this ability throughout the annual cycle-especially during flight-feather moult, in which wing area is reduced. To quantify the aerodynamic characteristics and flow mechanisms of a hummingbird wing throughout the annual cycle, time-accurate aerodynamic loads and flow field measurements were correlated over a dynamically scaled wing model of Anna's hummingbird ( Calypte anna ). We present measurements recorded over a model of a complete wing to evaluate the baseline aerodynamic characteristics and flow mechanisms. We found that the vorticity concentration that had developed from the wing's leading-edge differs from the attached vorticity structure that was typically found over insects' wings; firstly, it is more elongated along the wing chord, and secondly, it encounters high levels of fluctuations rather than a steady vortex. Lift characteristics resemble those of insects; however, a 20% increase in the lift-to-torque ratio was obtained for the hummingbird wing model. Time-accurate aerodynamic loads were also used to evaluate the time-evolution of the specific power required from the flight muscles, and the overall wingbeat power requirements nicely matched previous studies. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20160005742&hterms=cycles&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dcycles','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20160005742&hterms=cycles&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dcycles">The Observed State of the Water Cycle in the Early Twenty-First Century</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Rodell, M.; Beaudoing, H. K.; L'Ecuyer, T. S.; Olson, W. S.; Famiglietti, J. S.; Houser, P. R.; Adler, R.; Bosilovich, M. G.; Clayson, C. A.; Chambers, D.; <a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20160005742'); toggleEditAbsImage('author_20160005742_show'); toggleEditAbsImage('author_20160005742_hide'); "> <img style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_20160005742_show"> <img style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_20160005742_hide"> 2015-01-01 This study quantifies mean annual and monthly fluxes of Earth's water cycle over continents and ocean basins during the first decade of the millennium. To the extent possible, the flux estimates are based on satellite measurements first and data-integrating models second. A careful accounting of uncertainty in the estimates is included. It is applied within a routine that enforces multiple water and energy budget constraints simultaneously in a variational framework in order to produce objectively determined optimized flux estimates. In the majority of cases, the observed annual surface and atmospheric water budgets over the continents and oceans close with much less than 10% residual. Observed residuals and optimized uncertainty estimates are considerably larger for monthly surface and atmospheric water budget closure, often nearing or exceeding 20% in North America, Eurasia, Australia and neighboring islands, and the Arctic and South Atlantic Oceans. The residuals in South America and Africa tend to be smaller, possibly because cold land processes are negligible. Fluxes were poorly observed over the Arctic Ocean, certain seas, Antarctica, and the Australasian and Indonesian islands, leading to reliance on atmospheric analysis estimates. Many of the satellite systems that contributed data have been or will soon be lost or replaced. Models that integrate ground-based and remote observations will be critical for ameliorating gaps and discontinuities in the data records caused by these transitions. Continued development of such models is essential for maximizing the value of the observations. Next-generation observing systems are the best hope for significantly improving global water budget accounting. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.H43E1555L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.H43E1555L">Water Cycle Extremes: from Observations to Decisions</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Lawford, R. G.; Unninayar, S.; Berod, D. 2015-12-01 Extremes in the water cycle (droughts and floods) pose major challenges for water resource managers and emergency services. These challenges arise from observational and prediction systems, advisory services, impact reduction strategies, and cleanup and recovery operations. The Group on Earth Observations (GEO) through its Water Strategy ("GEOSS Water Strategy: from observations to decisions") is seeking to provide systems that will enable its members to more effectively meet their information needs prior to and during an extreme event. This presentation reviews the wide range of impacts that arise from extremes in the water cycle and the types of data and information needed to plan for and respond to these extreme events. It identifies the capabilities and limitations of current observational and analysis systems in defining the scale, timing, intensity and impacts of water cycle extremes and in directing society's response to them. This summary represents an early preliminary assessment of the global and regional information needs of water resource managers and begins to outline a strategy within GEO for using Earth Observations and ancillary information to address these needs. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017Geomo.299....1B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017Geomo.299....1B">Temporal dynamics of flooding, evaporation, and desiccation cycles and observations of salt crust area change at the Bonneville Salt Flats, Utah</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Bowen, Brenda B.; Kipnis, Evan L.; Raming, Logan W. 2017-12-01 The Bonneville Salt Flats (BSF) in Utah is a dynamic saline playa environment responding to natural and anthropogenic forces. Over the last century, the saline groundwater from below BSF has been harvested to produce potash via evaporative mining, mostly used as agricultural fertilizers, while the surface halite crust has provided a significant recreational site for land speed racing. Perceptions of changes in the salt crust through time have spurred debates about land use and management; however, little is known about the timescales of natural change as the salt crust responds to climatic parameters that drive flooding, evaporation, and desiccation (FED) cycles that control surface salt growth and dissolution. Climate data over the last 30 years are examined to identify annual patterns in surface water balance at BSF to identify annual and seasonal climate constraints on FED cycles. Landsat satellite data from 1986 to the present are used to map the areal extent of the surface halite salt crust at BSF at the end of the desiccation season (between August 15 and October 30) annually. Overall, the observed area of the desiccation-stage BSF halite crust has varied from a maximum of 156 km2 in 1993 to a minimum of 72 km2 in 2014 with an overall trend of declining area of halite observed over the 30 years of analysis. Climatic variables that influence FED cycles and seasonal salt dissolution and precipitation have also varied through this time period; however, the relationship between surface water fluxes and salt crust area do not clearly correlate, suggesting that other processes are influencing the extent of the salt. Intra-annual analyses of salt area and weather illustrate the importance of ponded surface water, wind events, and microtopography in shaping a laterally extensive but thin and ephemeral halite crust. Examination of annual to decadal changes in salt crust extent and environmental parameters at BSF provides insights into the processes driving change and </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006IzAOP..42..300E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006IzAOP..42..300E">Sensitivity of amplitude-phase characteristics of the surface air temperature annual cycle to variations in annual mean temperature</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Eliseev, A. V.; Mokhov, I. I.; Guseva, M. S. 2006-05-01 The ERA40 and NCEP/NCAR data over 1958 1998 were used to estimate the sensitivity of amplitude-phase characteristics (APCs) of the annual cycle (AC) of the surface air temperature (SAT) T s. The results were compared with outputs of the ECHAM4/OPYC3, HadCM3, and INM RAS general circulation models and the IAP RAS climate model of intermediate complexity, which were run with variations in greenhouse gases and sulfate aerosol specified over 1860 2100. The analysis was performed in terms of the linear regression coefficients b of SAT AC APCs on the local annual mean temperature and in terms of the sensitivity characteristic D = br 2, which takes into account not only the linear regression coefficient but also its statistical significance (via the correlation coefficient r). The reanalysis data were used to reveal the features of the tendencies of change in the SAT AC APCs in various regions, including areas near the snow-ice boundary, storm-track ocean regions, large desert areas, and the tropical Pacific. These results agree with earlier observations. The model computations are in fairly good agreement with the reanalysis data in regions of statistically significant variations in SAT AC APCs. The differences between individual models and the reanalysis data can be explained, in particular, in terms of the features of the sea-ice schemes used in the models. Over the land in the middle and high latitudes of the Northern Hemisphere, the absolute values of D for the fall phase time and the interval of exceeding exhibit a positive intermodel correlation with the absolute value of D for the annual-harmonic amplitude. Over the ocean, the models reproducing larger (in modulus) sensitivity parameters of the SAT annual-harmonic amplitude are generally characterized by larger (in modulus) negative sensitivity values of the semiannual-harmonic amplitude T s, 2, especially at latitudes characteristic of the sea-ice boundary. In contrast to the averaged fields of AC APCs and their </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFM.U33B..07R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFM.U33B..07R">An Intensified Arctic Water Cycle? Trend Analysis of the Arctic System Freshwater Cycle: Observations and Expectations</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Rawlins, M. A.; Adam, J. C.; Vorosmarty, C. J.; Serreze, M. C.; Hinzman, L. D.; Holland, M.; Shiklomanov, A. 2007-12-01 It is expected that a warming climate will be attended by an intensification of the global hydrological cycle. While there are signs of positive trends in several hydrological quantities emerging at the global scale, the scope, character, and quantitative significance of these changes are not well established. In particular, long-term increases in river discharge across Arctic Eurasia are assumed to represent such an intensification and have received considerable attention. Yet, no change in long-term annual precipitation across the region can be related with the discharge trend. Given linkages and feedbacks between the arctic and global climate systems, a more complete understanding of observed changes across northern high latitudes is needed. We present a working definition of an accelerated or intensified hydrological cycle and a synthesis of long-term (nominally 50 years) trends in observed freshwater stocks and fluxes across the arctic land-atmosphere-ocean system. Trend and significance measures from observed data are described alongside expectations of intensification based on GCM simulations of contemporary and future climate. Our domain of interest includes the terrestrial arctic drainage (including all of Alaska and drainage to Hudson Bay), the Arctic Ocean, and the atmosphere over the land and ocean domains. For the terrestrial Arctic, time series of spatial averages which are derived from station data and atmospheric reanalysis are available. Reconstructed data sets are used for quantities such as Arctic Ocean ice and liquid freshwater transports. Study goals include a comprehensive survey of past changes in freshwater across the pan-arctic and a set of benchmarks for expected changes based on an ensemble of GCM simulations, and identification of potential mechanistic linkages which may be examined with contemporary remote sensing data sets. </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li class="active">3</li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_4" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li class="active">4</li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="61"> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1980STIN...8113516B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1980STIN...8113516B">Systems analysis techniques for annual cycle thermal energy storage solar systems</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Baylin, F. 1980-07-01 Community-scale annual cycle thermal energy storage solar systems are options for building heat and cooling. A variety of approaches are feasible in modeling ACTES solar systems. The key parameter in such efforts, average collector efficiency, is examined, followed by several approaches for simple and effective modeling. Methods are also examined for modeling building loads for structures based on both conventional and passive architectural designs. Two simulation models for sizing solar heating systems with annual storage are presented. Validation is presented by comparison with the results of a study of seasonal storage systems based on SOLANSIM, an hour-by-hour simulation. These models are presently used to examine the economic trade-off between collector field area and storage capacity. Programs directed toward developing other system components such as improved tanks and solar ponds or design tools for ACTES solar systems are examined. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70037567','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70037567">Analysis of the Arctic system for freshwater cycle intensification: Observations and expectations</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Rawlins, M.A.; Steele, M.; Holland, M.M.; Adam, J.C.; Cherry, J.E.; Francis, J.A.; Groisman, P.Y.; Hinzman, L.D.; Huntington, T.G.; Kane, D.L.; Kimball, J.S.; Kwok, R.; Lammers, R.B.; Lee, C.M.; Lettenmaier, D.P.; McDonald, K.C.; Podest, E.; Pundsack, J.W.; Rudels, B.; Serreze, Mark C.; Shiklomanov, A.; Skagseth, O.; Troy, T.J.; Vorosmarty, C.J.; Wensnahan, M.; Wood, E.F.; Woodgate, R.; Yang, D.; Zhang, K.; Zhang, T. 2010-01-01 Hydrologic cycle intensification is an expected manifestation of a warming climate. Although positive trends in several global average quantities have been reported, no previous studies have documented broad intensification across elements of the Arctic freshwater cycle (FWC). In this study, the authors examine the character and quantitative significance of changes in annual precipitation, evapotranspiration, and river discharge across the terrestrial pan-Arctic over the past several decades from observations and a suite of coupled general circulation models (GCMs). Trends in freshwater flux and storage derived from observations across the Arctic Ocean and surrounding seas are also described. With few exceptions, precipitation, evapotranspiration, and river discharge fluxes from observations and the GCMs exhibit positive trends. Significant positive trends above the 90% confidence level, however, are not present for all of the observations. Greater confidence in the GCM trends arises through lower interannual variability relative to trend magnitude. Put another way, intrinsic variability in the observations tends to limit confidence in trend robustness. Ocean fluxes are less certain, primarily because of the lack of long-term observations. Where available, salinity and volume flux data suggest some decrease in saltwater inflow to the Barents Sea (i.e., a decrease in freshwater outflow) in recent decades. A decline in freshwater storage across the central Arctic Ocean and suggestions that large-scale circulation plays a dominant role in freshwater trends raise questions as to whether Arctic Ocean freshwater flows are intensifying. Although oceanic fluxes of freshwater are highly variable and consistent trends are difficult to verify, the other components of the Arctic FWC do show consistent positive trends over recent decades. The broad-scale increases provide evidence that the Arctic FWC is experiencing intensification. Efforts that aim to develop an adequate </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24830756','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24830756">Variations in evapotranspiration and climate for an Amazonian semi-deciduous forest over seasonal, annual, and El Niño cycles.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Vourlitis, George L; de Souza Nogueira, José; de Almeida Lobo, Francisco; Pinto, Osvaldo Borges 2015-02-01 Tropical forests exchange large amounts of water and energy with the atmosphere and are important in controlling regional and global climate; however, climate and evaportranspiration (E) vary significantly across multiple time scales. To better understand temporal patterns in E and climate, we measured the energy balance and meteorology of a semi-deciduous forest in the rainforest-savanna ecotone of northern Mato Grosso, Brazil, over a 7-year period and analyzed regional climate patterns over a 16-year period. Spectral analysis revealed that E and local climate exhibited consistent cycles over annual, seasonal, and weekly time scales. Annual and seasonal cycles were also apparent in the regional monthly rainfall and humidity time series, and a cycle on the order of 3-5.5 years was also apparent in the regional air temperature time series, which is coincident with the average return interval of El Niño. Annual rates of E were significantly affected by the 2002 El Niño. Prior to this event, annual E was on average 1,011 mm/year and accounted for 52% of the annual rainfall, while after, annual E was 931 mm/year and accounted for 42% of the annual rainfall. Our data also suggest that E declined significantly over the 7-year study period while air temperature significantly increased, which was coincident with a long-term, regional warming and drying trend. These results suggest that drought and warming induced by El Niño and/or climate change cause declines in E for semi-deciduous forests of the southeast Amazon Basin. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015IJBm...59..217V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015IJBm...59..217V">Variations in evapotranspiration and climate for an Amazonian semi-deciduous forest over seasonal, annual, and El Niño cycles</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Vourlitis, George L.; de Souza Nogueira, José; de Almeida Lobo, Francisco; Pinto, Osvaldo Borges 2015-02-01 Tropical forests exchange large amounts of water and energy with the atmosphere and are important in controlling regional and global climate; however, climate and evaportranspiration ( E) vary significantly across multiple time scales. To better understand temporal patterns in E and climate, we measured the energy balance and meteorology of a semi-deciduous forest in the rainforest-savanna ecotone of northern Mato Grosso, Brazil, over a 7-year period and analyzed regional climate patterns over a 16-year period. Spectral analysis revealed that E and local climate exhibited consistent cycles over annual, seasonal, and weekly time scales. Annual and seasonal cycles were also apparent in the regional monthly rainfall and humidity time series, and a cycle on the order of 3-5.5 years was also apparent in the regional air temperature time series, which is coincident with the average return interval of El Niño. Annual rates of E were significantly affected by the 2002 El Niño. Prior to this event, annual E was on average 1,011 mm/year and accounted for 52 % of the annual rainfall, while after, annual E was 931 mm/year and accounted for 42 % of the annual rainfall. Our data also suggest that E declined significantly over the 7-year study period while air temperature significantly increased, which was coincident with a long-term, regional warming and drying trend. These results suggest that drought and warming induced by El Niño and/or climate change cause declines in E for semi-deciduous forests of the southeast Amazon Basin. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/20834','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/20834">Ecological life cycle of Chaerophyllum procumbens variety shortii (Apiacheae), a winter annual of the North American dedicuous forest</a> <a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a> Carol C. Baskin; Tracy S. Hawkins; Jerry M. Baskin 2004-01-01 Numerous winter annuals occur in temperate eastern North America. Based on life cycle information and flowering period, the flora of northeastern USA and adjacent Canada described in Gray's Manual of Botany (Fernald 1950) contains 96 winter annuals (C. Baskin unpublished). This list includes native and introduced species in 57 genera and 23 families. The majority... </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFM.A11C0608L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFM.A11C0608L">Using CFC-12 and HCl to quantify the annual cycle of the stratospheric contribution to ozone in the Arctic troposphere</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Liang, Q.; Douglass, A. R.; Duncan, B. N.; Stolarski, R. S.; Witte, J. C. 2007-12-01 In this study, we use CFC-12 and hydrochloric acid (HCl) to quantify the annual cycle of stratosphere-to- troposphere transport of O3 to the Arctic troposphere. To do so, we analyze results from a 5-year stratosphere and troposphere simulation from the Global Modeling Initiative (GMI) Chemical Transport Model (CTM) for 1994- 1998 and a 10-year simulation using the GEOS Chemistry Climate Model (GEOS CCM) for 1995-2004. The later includes a tagged CFC-12 tracer to track the transport of aged stratospheric air into the troposphere. We compare the simulated CFC-12 with 10 years surface CFC-12 measurements at two NOAA-GMD sites, Alert and Barrow. We compare O3 with 10 years of ozonesondes at Alert, Eureka, and Resolute. CFC-12, HCl and O3 are all compared with satellite observations from the Advanced Composition Explorer (ACE) and several MkIV balloon measurements in the Arctic. The GEOS CCM and GMI CTM simulations capture well the observed magnitude and annual cycle of CFC-12, HCl, and O3 in the stratosphere and troposphere. Since CFC-12 is emitted at the surface and destroyed in the stratosphere while HCl and O3 are produced in the stratosphere, the stratospheric air shows strong correlation between HCl and O3 and anti-correlation between CFC-12 and O3. We use the CFC-12 tagged tracer to track the transport from the stratosphere to the troposphere and the subsequent transport into the lower troposphere in the Arctic. HCl is paired with O3 to quantify the stratospheric contribution to O3 in the troposphere by applying a scaling factor to the simulated HCl using the HCl-O3 regression ratio. O3 and its annual cycle in the upper troposphere are dominated by stratospheric influence, which peaks in spring. The stratospheric contribution decreases as altitude decreases, accompanied by a delay in the phase of maximum. In the middle troposphere (2-6km), the stratospheric contribution peaks during the summer and is comparable to that of net photochemistry. Due to inefficient </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996JGR...10116585O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996JGR...10116585O">Simulation of annual plankton productivity cycle in the Black Sea by a one-dimensional physical-biological model</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Oguz, Temel; Ducklow, Hugh; Malanotte-Rizzoli, Paola; Tugrul, Suleyman; Nezlin, Nikolai P.; Unluata, Umit 1996-07-01 The annual cycle of the plankton dynamics in the central Black Sea is studied by a one-dimensional vertically resolved physical-biological upper ocean model, coupled with the Mellor-Yamada level 2.5 turbulence closure scheme. The biological model involves interactions between the inorganic nitrogen (nitrate, ammonium), phytoplankton and herbivorous zooplankton biomasses, and detritus. Given a knowledge of physical forcing, the model simulates main observed seasonal and vertical characteristic features, in particular, formation of the cold intermediate water mass and yearly evolution of the upper layer stratification, the annual cycle of production with the fall and the spring blooms, and the subsurface phytoplankton maximum layer in summer, as well as realistic patterns of particulate organic carbon and nitrogen. The computed seasonal cycles of the chlorophyll and primary production distributions over the euphotic layer compare reasonably well with the data. Initiation of the spring bloom is shown to be critically dependent on the water column stability. It commences as soon as the convective mixing process weakens and before the seasonal stratification of surface waters begins to develop. It is followed by a weaker phytoplankton production at the time of establishment of the seasonal thermocline in April. While summer nutrient concentrations in the mixed layer are low enough to limit production, the layer between the thermocline and the base of the euphotic zone provides sufficient light and nutrient to support subsurface phytoplankton development. The autumn bloom takes place sometime between October and December depending on environmental conditions. In the case of weaker grazing pressure to control the growth rate, the autumn bloom shifts to December-January and emerges as the winter bloom, or, in some cases, is connected with the spring bloom to form one unified continuous bloom structure during the January-March period. These bloom structures are similar to </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1244815-observing-terrestrial-ecosystems-carbon-cycle-from-space','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1244815-observing-terrestrial-ecosystems-carbon-cycle-from-space">Observing terrestrial ecosystems and the carbon cycle from space</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Schimel, David; Pavlick, Ryan; Fisher, Joshua B. 2015-02-06 Modeled terrestrial ecosystem and carbon cycle feedbacks contribute substantial uncertainty to projections of future climate. The limitations of current observing networks contribute to this uncertainty. Here we present a current climatology of global model predictions and observations for photosynthesis, biomass, plant diversity and plant functional diversity. Carbon cycle tipping points occur in terrestrial regions where fluxes or stocks are largest, and where biological variability is highest, the tropics and Arctic/Boreal zones. Global observations are predominately in the mid-latitudes and are sparse in high and low latitude ecosystems. Observing and forecasting ecosystem change requires sustained observations of sufficient density in timemore » and space in critical regions. Using data and theory available now, we can develop a strategy to detect and forecast terrestrial carbon cycle-climate interactions, by combining in situ and remote techniques.« less </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMSH12A..04K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMSH12A..04K">Helioseismology Observations of Solar Cycles and Dynamo Modeling</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Kosovichev, A. G.; Guerrero, G.; Pipin, V. 2017-12-01 Helioseismology observations from the SOHO and SDO, obtained in 1996-2017, provide unique insight into the dynamics of the Sun's deep interior for two solar cycles. The data allow us to investigate variations of the solar interior structure and dynamics, and compare these variations with dynamo models and simulations. We use results of the local and global helioseismology data processing pipelines at the SDO Joint Science Operations Center (Stanford University) to study solar-cycle variations of the differential rotation, meridional circulation, large-scale flows and global asphericity. By comparing the helioseismology results with the evolution of surface magnetic fields we identify characteristic changes associated the initiation and development of Solar Cycles 23 and 24. For the physical interpretation of observed variations, the results are compared with the current mean-field dynamo models and 3D MHD dynamo simulations. It is shown that the helioseismology inferences provide important constraints on the solar dynamo mechanism, may explain the fundamental difference between the two solar cycles, and also give information about the next solar cycle. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMEP21D1873A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMEP21D1873A">Replication of Annual Cycles in Mn in Hudson River Cores: Mn Peaks During High Water Flow</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Abbott, D. H.; Hutson, D.; Marrero, A. M.; Block, K. A.; Chang, C.; Cai, Y. 2017-12-01 Using the results from an ITRAX, XRF scanner, we previously reported apparent annual cycles in Mn in a single, high sedimentation rate Hudson River core, LWB1-8, taken off Yonkers, NY (Carlson et al., 2016). We replicated these results in three more high sedimentation rate cores and found stratigraphic markers that verify our inferences about the annual nature of the Mn cycles. The three new cores are LWB4-5 taken off Peekskill, NY, and LWB3-44 and LWB3-25, both taken in Haverstraw Bay. The cores are from water depths of 7-9 meters and all have high magnetic susceptibilities (typically > 30 cgs units) in their upper 1 to 2 meters. The high susceptibilities are primarily produced by magnetite from modern industrial combustion. One core, LWB1-8, has reconnaissance Cs dates that verify the annual nature of the cycles. More Cs dates are expected before the meeting. We developed several new methods of verifying the annual nature of our layer counts. The first is looking at the grain size distribution and age of layers with unusually high Mn peaks. Peaks in Si, Ni and Ti and peaks in percentage of coarse material typically accompany the peaks in Mn. Some are visible as yellow sandy layers. The five highest peaks in Mn in LWB1-8 have layer counted ages that correspond (within 1 year in the top meter and within 2 years in the bottom meter) to 1996, 1948, 1913, 1857 and 1790. The latter three events are the three largest historical spring freshets on the Hudson. 1996 is a year of unusually high flow rate during the spring freshet. Based on our work and previous work on Mn cycling in rivers, we infer that the peaks in Mn are produced by extreme erosional events that erode sediment and release pore water Mn into the water column. The other methods of testing our chronology involve marine storms that increase Ca and Sr and a search for fragments of the Peekskill meteorite that fell in October 1992. More information on the latter will be available by the meeting. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20070034032&hterms=water+conservation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dwater%2Bconservation','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20070034032&hterms=water+conservation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dwater%2Bconservation">Spacebased Observations of Oceanic Influence on the Annual Variation of South American Water Balance</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Liu, W. Timothy; Xie, Xiaosu; Tang, Wenqing; Zlotnicki, Victor 2006-01-01 The mass change of South America (SA) continent measured by the Gravity Recovery and Climate Experiment (GRACE) imposes a constraint on the uncertainties in estimating the annual variation of rainfall measured by Tropical Rain Measuring Mission (TRMM) and ocean moisture influx derived from QuikSCAT data. The approximate balance of the mass change rate with the moisture influx less climatological river discharge, in agreement with the conservation principle, bolsters not only the credibility of the spacebased measurements, but supports the characterization of ocean's influence on the annual variation of continental water balance. The annual variation of rainfall is found to be in phase with the mass change rate in the Amazon and the La Plata basins, and the moisture advection across relevant segments of the Pacific and Atlantic coasts agrees with the annual cycle of rainfall in the two basins and the Andes mountains. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=Impact+AND+environmental&pg=3&id=EJ950096','ERIC'); return false;" href="https://eric.ed.gov/?q=Impact+AND+environmental&pg=3&id=EJ950096">Using Screening Level Environmental Life Cycle Assessment to Aid Decision Making: A Case Study of a College Annual Report</a> <a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a> Ingwersen, Wesley W.; Curran, Mary Ann; Gonzalez, Michael A.; Hawkins, Troy R. 2012-01-01 Purpose: The purpose of this study is to compare the life cycle environmental impacts of the University of Cincinnati College of Engineering and Applied Sciences' current printed annual report to a version distributed via the internet. Design/methodology/approach: Life cycle environmental impacts of both versions of the report are modeled using… </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993DSRI...40..653J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993DSRI...40..653J">Annual cycles of mass flux and isotopic composition of pteropod shells settling into the deep Sargasso sea</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Jasper, John P.; Deuser, Werner G. 1993-04-01 Mass fluxes and stable isotopic compositions ( δ18O and δ13C) pteropod shells collected during a 6-year series of 2-month sediment-trap deployments in the deep (3.2 km) Sargasso Sea provide information on annual population changes, habitat depths and life spans of thecosome pteropods (Euthecosomata). The flux of pteropod shells responds to the annual cycle of primary production in the upper ocean. Flux maxima of the shells (> 1 mm) of eight species occur from late winter through autumn. Seasonal changes in the hydrography of the upper water column are quite accurately recorded in the δ18O variations of six perennial species, which generally confirm the distinction between non-migratory ( Creseis acicula, Creseis virgula conica, and Diacria quadridentata) and diurnally migratory taxa ( Styliola subula, Cuvierina columnella, and Clio pyramidata). Isotopic records of C. acicula and C. virgula conica are consistent with shell formation above 50 m. The records of the migratory species reflect what appear to be average calcification depths of 50-75 m. Average annual δ13C variations reveal the annual cycles of primary production and stratification of near-surface waters. Adult life spans of the species studied appear to be no more than a few months. The results of this study should be useful in paleoceanographic reconstructions based on isotopic measurements of sedimentary pteropod shells. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://www.jstor.org/stable/2693447','USGSPUBS'); return false;" href="http://www.jstor.org/stable/2693447">Variation in survivorship of a migratory songbird throughout its annual cycle</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Sillett, T. Scott; Holmes, Richard T. 2002-01-01 1. Demographic data from both breeding and non-breeding periods are needed to manage populations of migratory birds, many of which are declining in abundance and are of conservation concern. Although habitat associations, and to a lesser extent, reproductive biology, are known for many migratory species, few studies have measured survival rates of these birds at different parts of their annual cycle. 2. Cormack-Jolly-Seber models and Akaike's information criterion model selection were used to investigate seasonal variation in survival of a Nearctic - Neotropical migrant songbird, the black-throated blue warbler, Dendroica caerulescens. Seasonal and annual survival were estimated from resightings of colour-ringed individuals on breeding grounds in New Hampshire, USA from 1986 to 2000 and on winter quarters in Jamaica, West Indies from 1986 to 1999. Warblers were studied each year during the May-August breeding period in New Hampshire and during the October-March overwinter period in Jamaica. 3. In New Hampshire, males had higher annual survival (0.51 + 0.03) and recapture probabilities (0.93 + 0.03) than did females (survival: 0.40 + 0.04; recapture: 0'87 + 0.06). In Jamaica, annual survival (0.43 + 0.03) and recapture (0'95 + 0.04) probabilities did not differ between sexes. Annual survival and recapture probabilities of young birds (i.e. yearlings in New Hampshire and hatch-year birds in Jamaica) did not differ from adults, indicating that from the time hatch-year individuals acquire territories on winter quarters in mid-October, they survive as well as adults within the same habitat. 4. Monthly survival probabilities during the summer (May-August) and winter (October-March) stationary periods were high: 1'0 for males in New Hampshire, and 0.99 + 0.01 for males in Jamaica and for females in both locations. 5. These annual and seasonal survival estimates were used to calculate warbler survival for the migratory periods. Monthly survival probability during migration </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70024830','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70024830">Variation in survivorship of a migratory songbird throughout its annual cycle</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Scott, Sillett T.; Holmes, Richard T. 2002-01-01 1. Demographic data from both breeding and non-breeding periods are needed to manage populations of migratory birds, many of which are declining in abundance and are of conservation concern. Although habitat associations, and to a lesser extent, reproductive biology, are known for many migratory species, few studies have measured survival rates of these birds at different parts of their annual cycle. 2. Cormack-Jolly-Seber models and Akaike's information criterion model selection were used to investigate seasonal variation in survival of a Nearctic - Neotropical migrant songbird, the black-throated blue warbler, Dendroica caerulescens. Seasonal and annual survival were estimated from resightings of colour-ringed individuals on breeding grounds in New Hampshire, USA from 1986 to 2000 and on winter quarters in Jamaica, West Indies from 1986 to 1999. Warblers were studied each year during the May-August breeding period in New Hampshire and during the October-March overwinter period in Jamaica. 3. In New Hampshire, males had higher annual survival (0.51 ?? 0.03) and recapture probabilities (0.93 ?? 0.03) than did females (survival: 0.40 ?? 0.04; recapture: 0.87 ?? 0.06). In Jamaica, annual survival (0.43 ?? 0.03) and recapture (0.95 ?? 0.04) probabilities did not differ between sexes. Annual survival and recapture probabilities of young birds (i.e. yearlings in New Hampshire and hatch-year birds in Jamaica) did not differ from adults, indicating that from the time hatch-year individuals acquire territories on winter quarters in mid-October, they survive as well as adults within the same habitat. 4. Monthly survival probabilities during the summer (May-August) and winter (October-March) stationary periods were high: 1.0 for males in New Hampshire, and 0.99 ?? 0.01 for males in Jamaica and for females in both locations. 5. These annual and seasonal survival estimates were used to calculate warbler survival for the migratory periods. Monthly survival probability during </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JGRA..118.2503L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JGRA..118.2503L">Annual asymmetry in thermospheric density: Observations and simulations</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Lei, Jiuhou; Dou, Xiankang; Burns, Alan; Wang, Wenbin; Luan, Xiaoli; Zeng, Zhen; Xu, Jiyao 2013-05-01 In this paper, the Challenging Minisatellite Payload (CHAMP) and Gravity Recovery and Climate Experiment (GRACE) observations during 2002-2010 are utilized to study the variation of the annual asymmetry in thermospheric density at 400 km under low solar activity condition (F10.7 = 80) based on the method of empirical orthogonal functions (EOFs). The derived asymmetry index (AI) in thermospheric density from the EOF analysis shows a strong latitudinal variation at night but varies a little with latitudes in daytime. Moreover, it exhibits a terdiurnal tidal signature at low to middle latitudes. The global mean value of the AI is 0.191, indicating that a 47% difference in thermosphere between the December and June solstices in the global average. In addition, the NCAR Thermosphere-Ionosphere Electrodynamics Global Circulation Model (TIEGCM) is used to explore the possible mechanisms responsible for the observed annual asymmetry in thermospheric density. It is found that the standard simulations give a lower AI and also a weaker day-to-night difference. The simulated AI shows a semidiurnal pattern in the equatorial and low-latitude regions in contrast with the terdiurnal tide signature seen in the observed AI. The daily mean AI obtained from the simulation is 0.125, corresponding to a 29% December-to-June difference in thermospheric density at 400 km. Further sensitivity simulations demonstrated that the effect of the varying Sun-Earth distance between the December and June solstices is the main process responsible for the annual asymmetry in thermospheric density, while the magnetic field configuration and tides from the lower atmosphere contribute to the temporal and spatial variations of the AI. Specifically, the simulations show that the Sun-Earth distance effect explains 93% of the difference in thermospheric density between December and June, which is mainly associated with the corresponding changes in neutral temperature. However, our calculation from the </li> <li> <a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=59911&keyword=Ph+AND+Biochemistry&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=59911&keyword=Ph+AND+Biochemistry&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50">SEX-LINKED CHANGES IN PHASE 1 BIOTRANSFORMATION OF PHENOL IN BROOK TROUT OVER AN ANNUAL REPRODUCTIVE CYCLE</a> <a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a> The microsomal metabolism of phenol (11 degrees C) over an annual reproductive cycle from June to December has been studied using fall spawning adult brook trout (Salvelinus fontinalis). Incubations were optimized for time, cofactor connection, pH, and microsomal protein concentr... </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2010-12-27/pdf/2010-32341.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2010-12-27/pdf/2010-32341.pdf">75 FR 81201 - 2011 Annual Determination for Sea Turtle Observer Requirement</a> <a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a> 2010-12-27 ...-XA016 2011 Annual Determination for Sea Turtle Observer Requirement AGENCY: National Marine Fisheries... observers upon NMFS' request. The purpose of observing identified fisheries is to learn more about sea turtle interactions in a given fishery, evaluate existing measures to prevent or reduce prohibited sea... </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23590427','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23590427">Temperature, light and nitrate sensing coordinate Arabidopsis seed dormancy cycling, resulting in winter and summer annual phenotypes.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Footitt, Steven; Huang, Ziyue; Clay, Heather A; Mead, Andrew; Finch-Savage, William E 2013-06-01 Seeds use environmental cues to sense the seasons and their surroundings to initiate the life cycle of the plant. The dormancy cycling underlying this process is extensively described, but the molecular mechanism is largely unknown. To address this we selected a range of representative genes from published array experiments in the laboratory, and investigated their expression patterns in seeds of Arabidopsis ecotypes with contrasting life cycles over an annual dormancy cycle in the field. We show how mechanisms identified in the laboratory are coordinated in response to the soil environment to determine the dormancy cycles that result in winter and summer annual phenotypes. Our results are consistent with a seed-specific response to seasonal temperature patterns (temporal sensing) involving the gene DELAY OF GERMINATION 1 (DOG1) that indicates the correct season, and concurrent temporally driven co-opted mechanisms that sense spatial signals, i.e. nitrate, via CBL-INTERACTING PROTEIN KINASE 23 (CIPK23) phosphorylation of the NITRATE TRANSPORTER 1 (NRT1.1), and light, via PHYTOCHROME A (PHYA). In both ecotypes studied, when all three genes have low expression there is enhanced GIBBERELLIN 3 BETA-HYDROXYLASE 1 (GA3ox1) expression, exhumed seeds have the potential to germinate in the laboratory, and the initiation of seedling emergence occurs following soil disturbance (exposure to light) in the field. Unlike DOG1, the expression of MOTHER of FLOWERING TIME (MFT) has an opposite thermal response in seeds of the two ecotypes, indicating a role in determining their different dormancy cycling phenotypes. © 2013 The Authors The Plant Journal © 2013 John Wiley & Sons Ltd. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AnGeo..27.3225M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AnGeo..27.3225M">Solar cycle signatures in the NCEP equatorial annual oscillation</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Mayr, H. G.; Mengel, J. G.; Huang, F. T.; Nash, E. R. 2009-08-01 Our analysis of temperature and zonal wind data (1958 to 2006) from the National Center for Atmospheric Research (NCAR) reanalysis (Re-1), supplied by the National Centers for Environmental Prediction (NCEP), shows that the hemispherically symmetric 12-month equatorial annual oscillation (EAO) contains spectral signatures with periods around 11 years. Moving windows of 44 years show that, below 20 km, the 11-year modulation of the EAO is phase locked to the solar cycle (SC). The spectral features from the 48-year data record reveal modulation signatures of 9.6 and 12 years, which produce EAO variations that mimic in limited altitude regimes the varying maxima and minima of the 10.7 cm flux solar index. Above 20 km, the spectra also contain modulation signatures with periods around 11 years, but the filtered variations are too irregular to suggest that systematic SC forcing is the principal agent. </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li class="active">4</li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_5" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active">5</li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="81"> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/5480931-observations-statistical-simulations-proposed-solar-cycle-qbo-weather-relationship','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/5480931-observations-statistical-simulations-proposed-solar-cycle-qbo-weather-relationship">Observations and statistical simulations of a proposed solar cycle/QBO/weather relationship</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Baldwin, M.P.; Dunkerton, T.J. 1989-08-01 The 10.7 cm solar flux is observed to be highly correlated with north pole stratospheric temperatures when partitioned according to the phase of the equatorial stratospheric winds (the quasi-biennial oscillation, or QBO). The authors supplement observations with calculations showing that temperatures over most of the northern hemisphere are highly correlated or anticorrelated with north pole temperatures. The observed spatial pattern of solar cycle correlations at high latitudes is shown to be not unique to the solar cycle. The authors present results, similar to the observed solar cycle correlations, with simulated harmonics of various periods replacing the solar cycle. These calculationsmore » demonstrate the correlations at least as high as those for the solar cycle results may be obtained using simulated harmonics.« less </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/19813','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/19813">Carbon cycle observations: gaps threaten climate mitigation policies</a> <a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a> Richard Birdsey; Nick Bates; MIke Behrenfeld; Kenneth Davis; Scott C. Doney; Richard Feely; Dennis Hansell; Linda Heath; et al. 2009-01-01 Successful management of carbon dioxide (CO2) requires robust and sustained carbon cycle observations. Yet key elements of a national observation network are lacking or at risk. A U.S. National Research Council review of the U.S. Climate Change Science Program earlier this year highlighted the critical need for a U.S. climate observing system to... </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ClDy..tmp..901L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ClDy..tmp..901L">A process-level attribution of the annual cycle of surface temperature over the Maritime Continent</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Li, Yana; Yang, Song; Deng, Yi; Hu, Xiaoming; Cai, Ming 2017-12-01 The annual cycle of the surface temperature over the Maritime Continent (MC) is characterized by two periods of rapid warming in March-April and September-October, respectively, and a period of rapid cooling in June-July. Based upon an analysis of energy balance within individual atmosphere-surface columns, the seasonal variations of surface temperature in the MC are partitioned into partial temperature changes associated with various radiative and non-radiative (dynamical) processes. The seasonal variations in direct solar forcing and surface latent heat flux show the largest positive contributions to the annual cycle of MC surface temperature while the changes in oceanic dynamics (including ocean heat content change) work against the temperature changes related to the annual cycle. The rapid warming in March-April is mainly a result of the changes in atmospheric quick processes and ocean-atmosphere coupling such as water vapor, surface latent heat flux, clouds, and atmospheric dynamics while the contributions from direct solar forcing and oceanic dynamics are negative. This feature is in contrast to that associated with the warming in September-October, which is driven mainly by the changes in solar forcing with a certain amount of contributions from water vapor and latent heat flux change. More contribution from atmospheric quick processes and ocean-atmosphere coupling in March-April coincides with the sudden northward movement of deep convection belt, while less contribution from these quick processes and coupling is accompanied with the convection belt slowly moving southward. The main contributors to the rapid cooling in June-July are the same as those to the rapid warming in March-April, and the cooling is also negatively contributed by direct solar forcing and oceanic dynamics. The changes in water vapor in all three periods contribute positively to the change in total temperature and they are associated with the change in the location of the center of </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AAS...22221712A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AAS...22221712A">Exoplanet Observations in SOFIA's Cycle 1</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Angerhausen, Daniel 2013-06-01 The NASA/DLR Stratospheric Observatory for Infrared Astronomy (SOFIA), a 2.5-meter infrared telescope on board a Boeing 747-SP, will conduct 0.3 - 1,600 micron photometric, spectroscopic, and imaging observations from altitudes as high as 45,000 ft. The airborne-based platform has unique advantages in comparison to ground- and space-based observatories in the field of characterization of the physical properties of exoplanets: parallel optical and near-infrared photometric and spectrophotometric follow-up observations during planetary transits and eclipses will be feasible with SOFIA's instrumentation, in particular the HIPO-FLITECAM optical/NIR instruments and possible future dedicated instrumentation. Here we present spectrophotometric exoplanet observations that were or will be conducted in SOFIA's cycle 1. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19990019890&hterms=Wolves&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DWolves','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19990019890&hterms=Wolves&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DWolves">A Comparison of Wolf's Reconstructed Record of Annual Sunspot Number with Schwabe's Observed Record of Clusters of Spots for the Interval of 1826-1868</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Wilson, Robert M. 1998-01-01 Samuel Heinrich Schwabe, the discoverer of the sunspot cycle, observed the Sun routinely from Desau, Germany during the interval of 1826-1869, averaging about 290 observing days per year. His yearly counts of 'clusters of spots' (or, more correctly, the yearly number of newly appearing sunspot groups) provided a simple means for describing the overt features of the sunspot cycle (i.e., the timing and relative strengths of cycle minimum and maximum). In 1848, Rudolf Wolf, a Swiss astronomer, having become aware of Schwabe's discovery, introduced his now familiar 'relative sunspot number' and established an international cadre of observers for monitoring the future behavior of the sunspot cycle and for reconstructing its past behavior (backwards in time to 1818, based on daily sunspot number estimates). While Wolf's reconstruction is complete (without gaps) only from 1849 (hence, the beginning of the modern era), the immediately preceding interval of 1818-1848 is incomplete, being based on an average of 260 observing days per year. In this investigation, Wolf's reconstructed record of annual sunspot number is compared against Schwabe's actual observing record of yearly counts of clusters of spots. The comparison suggests that Wolf may have misplaced (by about 1-2 yr) and underestimated (by about 16 units of sunspot number) the maximum amplitude for cycle 7. If true, then, cycle 7's ascent and descent durations should measure about 5 years each instead of 7 and 3 years, respectively, the extremes of the distributions, and its maximum amplitude should measure about 96 instead of 70. This study also indicates that cycle 9's maximum amplitude is more reliably determined than cycle 8's and that both appear to be of comparable size (about 130 units of sunspot number) rather than being significantly different. Therefore, caution is urged against the indiscriminate use of the pre-modern era sunspot numbers in long-term studies of the sunspot cycle, since such use may lead to </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002cosp...34E2661W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002cosp...34E2661W">General Circulation Model Simulations of the Annual Cycle of Martian Climate</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Wilson, R.; Richardson, M.; Rodin, A. Observations of the martian atmosphere have revealed a strong annual modulation of global mean atmospheric temperature that has been attributed to the pronounced seasonal asymmetry in solar radiation and the highly variable distribution of aerosol. These observations indicate little interannual variability during the relatively cool aphelion season and considerable variability in the perihelion season that is associated with the episodic occurrence of regional and major dust storms. The atmospheric circulation responds to the evolving spatial distribution of aerosol-induced heating and, in turn, plays a major role in determining the sources, sinks, and transport of radiatively active aerosol. We will present simulations employing the GFDL Mars General Circulation Model (MGCM) that show that aspects of the seasonally evolving climate may be simulated in a self-consistent manner using simple dust source parameterizations that represent the effects of lifting associated with local dust storms, dust devil activity, and other processes. Aerosol transport is accomplished, in large part, by elements of the large-scale circulation such as the Hadley circulation, baroclinic storms, tides, etc. A seasonal cycle of atmospheric opacity and temperature results from the variation in the strength and distribution of dust sources as well as from seasonal variations in the efficiency of atmospheric transport associated with changes in the circulation between solstice and equinox, and between perihelion and aphelion. We examine the efficiency of atmospheric transport of dust lifted along the perimeter of the polar caps to gauge the influence of these storms on the global circulation. We also consider the influence of water, as the formation of water ice clouds on dust nuclei may also affect the vertical distribution of dust and strongly influence the aerosol radiative properties. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017APJAS..53..229M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017APJAS..53..229M">Temperature and precipitation in the context of the annual cycle over Asia: Model evaluation and future change</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Moon, Suyeon; Ha, Kyung-Ja 2017-05-01 Since the early or late arrival of monsoon rainfall can be devastating to agriculture and economy, the prediction of the onset of monsoon is a very important issue. The Asian monsoon is characterized by a strong annual cycle with rainy summer and dry winter. Nevertheless, most of monsoon studies have focused on the seasonal-mean of temperature and precipitation. The present study aims to evaluate a total of 27 coupled models that participated in phase 5 of the Coupled Model Intercomparison Project (CMIP5) for projection of the time evolution and the intensity of Asian monsoon on the basis of the annual cycle of temperature and precipitation. And future changes of onset, retreat, and intensity of monsoon are analyzed. Four models for good seasonal-mean (GSM) and good harmonic (GH) groups, respectively, are selected. GSM is based on the seasonal-mean of temperature and precipitation in summer and winter, and GH is based on the annual cycle of temperature and precipitation which represents a characteristic of the monsoon. To compare how well the time evolution of the monsoon is simulated in each group, the onset, retreat, and duration of Asian monsoon are examined. The highest pattern correlation coefficient (PCC) of onset, retreat, and duration between the reanalysis data and model outputs demonstrates that GH models' MME predicts time evolution of monsoon most precisely, with PCC values of 0.80, 0.52, and 0.63, respectively. To predict future changes of the monsoon, the representative concentration pathway 4.5 (RCP 4.5) experiments for the period of 2073-2099 are compared with historical simulations for the period of 1979-2005 from CMIP5 using GH models' MME. The Asian monsoon domain is expanded by 22.6% in the future projection. The onset date in the future is advanced over most parts of Asian monsoon region. The duration of summer Asian monsoon in the future projection will be lengthened by up to 2 pentads over the Asian monsoon region, as a result of advanced </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2010-05-18/pdf/2010-11856.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2010-05-18/pdf/2010-11856.pdf">75 FR 27649 - 2010 Annual Determination for Sea Turtle Observer Requirements</a> <a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a> 2010-05-18 ... enable the design of an appropriate sampling program and to ensure collection of sufficient scientific... Observer Coverage in a Fishery Listed on the 2010 Annual Determination The design of any observer program.... During the program design, NMFS will be guided by the following standards for distributing and placing... </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5579086','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5579086">Hovering hummingbird wing aerodynamics during the annual cycle. I. Complete wing</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> Sapir, Nir; Elimelech, Yossef 2017-01-01 The diverse hummingbird family (Trochilidae) has unique adaptations for nectarivory, among which is the ability to sustain hover-feeding. As hummingbirds mainly feed while hovering, it is crucial to maintain this ability throughout the annual cycle—especially during flight-feather moult, in which wing area is reduced. To quantify the aerodynamic characteristics and flow mechanisms of a hummingbird wing throughout the annual cycle, time-accurate aerodynamic loads and flow field measurements were correlated over a dynamically scaled wing model of Anna’s hummingbird (Calypte anna). We present measurements recorded over a model of a complete wing to evaluate the baseline aerodynamic characteristics and flow mechanisms. We found that the vorticity concentration that had developed from the wing’s leading-edge differs from the attached vorticity structure that was typically found over insects’ wings; firstly, it is more elongated along the wing chord, and secondly, it encounters high levels of fluctuations rather than a steady vortex. Lift characteristics resemble those of insects; however, a 20% increase in the lift-to-torque ratio was obtained for the hummingbird wing model. Time-accurate aerodynamic loads were also used to evaluate the time-evolution of the specific power required from the flight muscles, and the overall wingbeat power requirements nicely matched previous studies. PMID:28878971 </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/4523','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/4523">Estimation on the First Cycle of the Annual Forest Inventory System: Methods, Preliminary Results, and Observations</a> <a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a> Mark H. Hansen; Gary J. Brand; Daniel G. Wendt; Ronald E. McRoberts 2001-01-01 The first year of annual FIA data collection in the North Central region was completed for 1999 in Indiana, Iowa, Minnesota, and Missouri. Estimates of timberland area, total growing-stock volume and growing-stock volume per acre are presented. These estimates are based on data from 1 year, collected at the base Federal inventory intensity, a lower intensity sample... </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1817237V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1817237V">Effect of soil in nutrient cycle assessment at dairy farms</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> van Leeuwen, Maricke; de Boer, Imke; van Dam, Jos; van Middelaar, Corina; Stoof, Cathelijne 2016-04-01 Annual farm nutrient cycle assessments give valuable insight in the nutrient cycles and nutrient losses at dairy farms. It describes nutrient use efficiencies for the entire farm and for the underlying components cattle, manure, crops and soil. In many modelling studies, soil is kept as a constant factor, while soil quality is vital for soil functioning of the ecosystem. Improving soil quality will improve the nutrient cycle, and will also have positive effect on the soil functions crop production, water cycling and greenhouse gas mitigation. Spatial variation of soil properties within a farm, however, are not included in annual nutrient cycle assessments. Therefore it is impossible to identify fields where most profit can be gained by improving farm management at field level, and it is not possible to identify and to quantify nutrient flow path ways. The aim of this study is to develop a framework to improve the annual nutrient cycle assessment at Dutch dairy farms, by including soil properties and their spatial variation within farms. Soil type and soil quality will be described by visual soil assessment of soil quality characteristics. The visual observations will be linked to the nutrient cycle assessment, using soil-hydrological model SWAP. We will demonstrate how soil quality at field level can impact on crop production, eutrophication potential and greenhouse gas potential at farm level. Also, we will show how this framework can be used by farmers to improve their farm management. This new approach is focusing on annual nutrient cycle assessment, but could also be used in life cycle assessment. It will improve understanding of soil functioning and dairy farm management. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/1978/0155/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/1978/0155/report.pdf">A simple-harmonic model for depicting the annual cycle of seasonal temperatures of streams</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Steele, Timothy Doak 1978-01-01 Due to economic or operational constraints, stream-temperature records cannot always be collected at all sites where information is desired or at frequencies dictated by continuous or near-continuous surveillance requirements. For streams where only periodic measurements are made during the year, and that are not appreciably affected by regulation or by thermal loading , a simple harmonic function may adequately depict the annual seasonal cycle of stream temperature at any given site. Resultant harmonic coefficients obtained from available stream-temperature records may be used in the following ways: (1) To interpolate between discrete measurements by solving the harmonic function at specified times, thereby filling in estimates of stream-temperature values; (2) to characterize areal or regional patterns of natural stream-temperature values; (2) to characterize areal or regional patterns of natural stream-temperature conditions; and (3) to detect and to assess any significant at a site brought about by streamflow regulation or basin development. Moreover, less-than-daily or sampling frequencies at a given site may give estimates of annual variation of stream temperatures that are statistically comparable to estimates obtained from a daily or continuous sampling scheme. The latter procedure may result in potential savings of resources in network operations, with negligible loss in information on annual stream-temperature variations. (Woodard -USGS) </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.U41C0055S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.U41C0055S">Symptoms of change in multi-scale observations of arctic ecosystem carbon cycling</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Stoy, P. C.; Williams, M. D.; Hartley, I. P.; Street, L.; Hill, T. C.; Prieto-Blanco, A.; Wayolle, A.; Disney, M.; Evans, J.; Fletcher, B.; Poyatos, R.; Wookey, P.; Merbold, L.; Wade, T. J.; Moncrieff, J. 2009-12-01 sensing data into the DALEC ecosystem model using the ensemble Kalman filter. We use a flux footprint analysis to demonstrate that the ABACUS study ecosystems display functional convergence at chamber, tower and aircraft scales. The importance of the rapidly changing cold and ‘shoulder’ seasons to annual CO2 flux is emphasized; these represent over 20% of annual C exchange at our field sites. The role of moss in determining non-growing season C uptake and loss is highlighted using direct chamber-based observations. We demonstrate ‘priming’ of the decomposition of older forest soil during the period of vegetative activity using 14CO2 observations, and show that tundra ecosystems paradoxically store more C than birch forests in the region. This biological priming of older C stocks is not included in current models of the arctic C cycle. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=232911&keyword=us+AND+education&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=232911&keyword=us+AND+education&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50">Using screening level environmental life cycle assessment to aid decision making: A case study of a college annual report</a> <a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a> Purpose – In this study we compare the life cycle environmental impacts of the University of Cincinnati College of Engineering and Applied Sciences’ current printed annual report to a version distributed via the Internet. This case study demonstrates how a screening level life cy... </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010NW.....97..891P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010NW.....97..891P">Sexual dimorphism in immune function changes during the annual cycle in house sparrows</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Pap, Péter László; Czirják, Gábor Árpád; Vágási, Csongor István; Barta, Zoltán; Hasselquist, Dennis 2010-10-01 Difference between sexes in parasitism is a common phenomenon among birds, which may be related to differences between males and females in their investment into immune functions or as a consequence of differential exposure to parasites. Because life-history strategies change sex specifically during the annual cycle, immunological responses of the host aiming to reduce the impact of parasites may be sexually dimorphic. Despite the great complexity of the immune system, studies on immunoecology generally characterise the immune status through a few variables, often overlooking potentially important seasonal and gender effects. However, because of the differences in physiological and defence mechanisms among different arms of the immune system, we expect divergent responses of immune components to environmental seasonality. In male and female house sparrows ( Passer domesticus), we measured the major components of the immune system (innate, acquired, cellular and humoral) during four important life-history stages across the year: (1) mating, (2) breeding, (3) moulting and (4) during the winter capture and also following introduction to captivity in aviary. Different individuals were sampled from the same population during the four life cycle stages. We found that three out of eight immune variables showed a significant life cycle stage × sex interaction. The difference in immune response between the sexes was significant in five immune variables during the mating stage, when females had consistently stronger immune function than males, while variables varied generally non-significantly with sex during the remaining three life cycle stages. Our results show that the immune system is highly variable between life cycle stages and sexes, highlighting the potential fine tuning of the immune system to specific physiological states and environmental conditions. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29922380','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29922380">Skeletal Muscle Cell Damage Indicators in Volleyball Players after the Competitive Phase of the Annual Training Cycle.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Radojewski, Mateusz; Podgórski, Tomasz; Pospieszna, Barbara; Kryściak, Jakub; Śliwicka, Ewa; Karolkiewicz, Joanna 2018-06-01 The aim of the study was to evaluate the impact of the competitive phase on physiological and metabolic indices and selected markers of skeletal muscle damage in male volleyball players. The study group consisted of 24 young male volleyball players. During the study, participants underwent two series of measurements, before and after the competitive phase of the annual training cycle. In both study terms, players performed an incremental treadmill running test to determine their ventilatory threshold and maximal oxygen uptake. Venous and capillary blood samples were taken for biochemical analysis. There was no significant difference in the physical fitness level, values of biochemical variables and the level of antioxidant status in the surveyed athletes between the two study terms. Significant changes within skeletal muscle damage markers were observed between the beginning and the end of the competitive period: an increase in the concentration of cellular DNA damage products (8-hydroxy-2'-deoxyguanosine; p < 0.0001) and a decrease in muscle activity of creatine kinase (p<0.05). In spite of the increment in cell damage markers, the unaffected level of physiological and biochemical markers may indicate that the experienced cell destruction did not negatively affect the level of physical fitness. When designing the annual training plan, coaches and athletes need to take into consideration that temporary physiological states - oxidative stress and inflammation - may be required to attain training adaptation. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018BGeo...15.1843R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018BGeo...15.1843R">Coccolithophore populations and their contribution to carbonate export during an annual cycle in the Australian sector of the Antarctic zone</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Rigual Hernández, Andrés S.; Flores, José A.; Sierro, Francisco J.; Fuertes, Miguel A.; Cros, Lluïsa; Trull, Thomas W. 2018-03-01 The Southern Ocean is experiencing rapid and relentless change in its physical and biogeochemical properties. The rate of warming of the Antarctic Circumpolar Current exceeds that of the global ocean, and the enhanced uptake of carbon dioxide is causing basin-wide ocean acidification. Observational data suggest that these changes are influencing the distribution and composition of pelagic plankton communities. Long-term and annual field observations on key environmental variables and organisms are a critical basis for predicting changes in Southern Ocean ecosystems. These observations are particularly needed, since high-latitude systems have been projected to experience the most severe impacts of ocean acidification and invasions of allochthonous species. Coccolithophores are the most prolific calcium-carbonate-producing phytoplankton group playing an important role in Southern Ocean biogeochemical cycles. Satellite imagery has revealed elevated particulate inorganic carbon concentrations near the major circumpolar fronts of the Southern Ocean that can be attributed to the coccolithophore Emiliania huxleyi. Recent studies have suggested changes during the last decades in the distribution and abundance of Southern Ocean coccolithophores. However, due to limited field observations, the distribution, diversity and state of coccolithophore populations in the Southern Ocean remain poorly characterised. We report here on seasonal variations in the abundance and composition of coccolithophore assemblages collected by two moored sediment traps deployed at the Antarctic zone south of Australia (2000 and 3700 m of depth) for 1 year in 2001-2002. Additionally, seasonal changes in coccolith weights of E. huxleyi populations were estimated using circularly polarised micrographs analysed with C-Calcita software. Our findings indicate that (1) coccolithophore sinking assemblages were nearly monospecific for E. huxleyi morphotype B/C in the Antarctic zone waters in 2001-2002; (2 </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMGC11C0575R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMGC11C0575R">Modern Estimates of Global Water Cycle Fluxes</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Rodell, M.; Beaudoing, H. K.; L'Ecuyer, T. S.; Olson, W. S. 2014-12-01 The goal of the first phase of the NASA Energy and Water Cycle Study (NEWS) Water and Energy Cycle Climatology project was to develop "state of the global water cycle" and "state of the global energy cycle" assessments based on data from modern ground and space based observing systems and data integrating models. Here we describe results of the water cycle assessment, including mean annual and monthly fluxes over continents and ocean basins during the first decade of the millennium. To the extent possible, the water flux estimates are based on (1) satellite measurements and (2) data-integrating models. A careful accounting of uncertainty in each flux was applied within a routine that enforced multiple water and energy budget constraints simultaneously in a variational framework, in order to produce objectively-determined, optimized estimates. Simultaneous closure of the water and energy budgets caused the ocean evaporation and precipitation terms to increase by about 10% and 5% relative to the original estimates, mainly because the energy budget required turbulent heat fluxes to be substantially larger in order to balance net radiation. In the majority of cases, the observed annual, surface and atmospheric water budgets over the continents and oceans close with much less than 10% residual. Observed residuals and optimized uncertainty estimates are considerably larger for monthly surface and atmospheric water budget closure, often nearing or exceeding 20% in North America, Eurasia, Australia and neighboring islands, and the Arctic and South Atlantic Oceans. The residuals in South America and Africa tend to be smaller, possibly because cold land processes are a non-issue. Fluxes are poorly observed over the Arctic Ocean, certain seas, Antarctica, and the Australasian and Indonesian Islands, leading to reliance on atmospheric analysis estimates. Other details of the study and future directions will be discussed. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.P33F..08H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.P33F..08H">Surface-atmospheric water cycle at Gale crater through multi-year MSL/REMS observations</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Harri, A. M.; Genzer, M.; McConnochie, T. H.; Savijarvi, H. I.; Smith, M. D.; Martinez, G.; de la Torre Juarez, M.; Haberle, R. M.; Polkko, J.; Gomez-Elvira, J.; Renno, N. O.; Kemppinen, O.; Paton, M.; Richardson, M. I.; Newman, C. E.; Siili, T. T.; Mäkinen, T. 2017-12-01 The Mars Science laboratory (MSL) has been successfully operating for almost three Martian years. That includes an unprecedented long time series of atmospheric observations by the REMS instrument performing measurements of atmospheric pressure, relative humidity (REMS-H), temperature of the air, ground temperature, UV and wind speed and direction. The REMS-H relative humidity device is based on polymeric capacitive humidity sensors developed by Vaisala Inc. and it makes use of three (3) humidity sensor heads. The humidity device is mounted on the REMS boom providing ventilation with the ambient atmosphere through a filter protecting the device from airborne dust. The REMS-H humidity instrument has created an unprecedented data record of more than two full Martian. REMS-H measured the relative humidity and temperature at 1.6 m height for a period of 5 minutes every hour as part of the MSL/REMS instrument package. We focus on describing the annual in situ water cycle with the REMS-H instrument data for the period of almost three Martian years. The results will be constrained through comparison with independent indirect observations and through modeling efforts. We inferred the hourly atmospheric VMR from the REMS-H observations and compared these VMR measurements with predictions of VMR from our 1D column Martian atmospheric model and regolith to investigate the local water cycle, exchange processes and the local climate in Gale Crater. The strong diurnal variation suggests there are surface-atmosphere exchange processes at Gale Crater during all seasons, which depletes moisture to the ground in the evening and nighttime and release the moisture back to the atmosphere during the daytime. On the other hand, these processes do not seem to result in significant water deposition on the ground. Hence, our modelling results presumably indicate that adsorption processes take place during the nighttime and desorption during the daytime. Other processes, e.g. convective </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFM.A31A0851P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFM.A31A0851P">Assimilating Satellite SST Observations into a Diurnal Cycle Model</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Pimentel, S.; Haines, K.; Nichols, N. K. 2006-12-01 The wealth of satellite sea surface temperature (SST) data now available opens the possibility of large improvements in SST estimation. However the use of such data is not straight forward; a major difficulty in assimilating satellite observations is that they represent a near surface temperature, whereas in ocean models the top level represents the temperature at a greater depth. During the day, under favourable conditions of clear skies and calm winds, the near surface temperature is often seen to have a diurnal cycle that is picked up in satellite observations. Current ocean models do not have the vertical or temporal resolution to adequately represent this daytime warming. The usual approach is to discard daytime observations as they are considered diurnally `corrupted'. A new assimilation technique is developed here that assimilates observations into a diurnal cycle model. The diurnal cycle of SSTs are modelled using a 1-D mixed layer model with fine near surface resolution and 6 hourly forcing from NWP analyses. The accuracy of the SST estimates are hampered by uncertainties in the forcing data. The extent of diurnal SST warming at a particular location and time is predominately governed by a non-linear response to cloud cover and sea surface wind speeds which greatly affect the air-sea fluxes. The method proposed here combines infrared and microwave SST satellite observations in order to derive corrections to the cloud cover and wind speed values over the day. By adjusting the forcing, SST estimation and air-sea fluxes should be improved and are at least more consistent with each other. This new technique for assimilating SST data can be considered a tool for producing more accurate diurnal warming estimates. </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active">5</li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_6" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active">6</li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="101"> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JSWSC...6A..40M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JSWSC...6A..40M">Solar spectral irradiance variability in cycle 24: observations and models</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Marchenko, Sergey V.; DeLand, Matthew T.; Lean, Judith L. 2016-12-01 Utilizing the excellent stability of the Ozone Monitoring Instrument (OMI), we characterize both short-term (solar rotation) and long-term (solar cycle) changes of the solar spectral irradiance (SSI) between 265 and 500 nm during the ongoing cycle 24. We supplement the OMI data with concurrent observations from the Global Ozone Monitoring Experiment-2 (GOME-2) and Solar Radiation and Climate Experiment (SORCE) instruments and find fair-to-excellent, depending on wavelength, agreement among the observations, and predictions of the Naval Research Laboratory Solar Spectral Irradiance (NRLSSI2) and Spectral And Total Irradiance REconstruction for the Satellite era (SATIRE-S) models. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19960016602&hterms=motes&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dmotes','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19960016602&hterms=motes&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dmotes">The annual cycle of stratospheric water vapor in a general circulation model</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Mote, Philip W. 1995-01-01 The application of general circulation models (GCM's) to stratospheric chemistry and transport both permits and requires a thorough investigation of stratospheric water vapor. The National Center for Atmospheric Research has redesigned its GCM, the Community Climate Model (CCM2), to enable studies of the chemistry and transport of tracers including water vapor; the importance of water vapor to the climate and chemistry of the stratosphere requires that it be better understood in the atmosphere and well represented in the model. In this study, methane is carried as a tracer and converted to water; this simple chemistry provides an adequate representation of the upper stratospheric water vapor source. The cold temperature bias in the winter polar stratosphere, which the CCM2 shares with other GCM's, produces excessive dehydration in the southern hemisphere, but this dry bias can be ameliorated by setting a minimum vapor pressure. The CCM2's water vapor distribution and seasonality compare favorably with observations in many respects, though seasonal variations including the upper stratospheric semiannual oscillation are generally too small. Southern polar dehydration affects midlatitude water vapor mixing ratios by a few tenths of a part per million, mostly after the demise of the vortex. The annual cycle of water vapor in the tropical and northern midlatitude lower stratosphere is dominated by drying at the tropical tropopause. Water vapor has a longer adjustment time than methane and had not reached equilibrium at the end of the 9 years simulated here. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOS.B24A0306N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOS.B24A0306N">Annual Cycles of Deep-ocean, Biogeochemical Export Fluxes and Biological Pump Processes in Subtropical and Subantarctic Waters, Southwest Pacific Ocean</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Nodder, S.; Chiswell, S.; Northcote, L. 2016-02-01 One of the key aspects of the global carbon cycle is the efficiency and spatio-temporal variability of the biological pump. In this paper, the annual cycles of particle fluxes, derived from moored sediment trap data collected from 2000-12 in subtropical (STW) and subantarctic waters (SAW), east of New Zealand, are presented. These observations are the most comprehensive export flux time-series from temperate Southern Hemisphere latitudes to date. With high levels of variability, fluxes in SAW were markedly lower than in STW, reflecting the picophytoplankton-dominated communities in the iron-limited, high nutrient-low chlorophyll SAW. Austral spring chlorophyll blooms in surface STW were near-synchronous with elevated fluxes of bio-siliceous, carbonate and organic carbon-rich materials to the deep ocean, probably facilitated by diatom sedimentation. Lithogenic fluxes were also high in STW, compared to SAW, reflecting proximity to the New Zealand landmass. In contrast, the highest biogenic fluxes in SAW occurred in spring when surface chlorophyll concentrations were low, while highest annual chlorophyll concentrations were in summer with no associated flux increase. We hypothesize that the high spring export in SAW occurs from subsurface chlorophyll accumulations that are not evident from remote-sensing satellites. This material was also rich in biogenic silica, perhaps related to the preferential export of diatoms and other silica-producing organisms, such as silicoflagellates and radiolarians. Particle fluxes in STW are similar to that of other mesotrophic to oligotrophic waters ( 6-7 mgC m-2 d-1), whereas export from SAW is below global averages ( 3 mgC m-2 d-1), and is characterized by carbonate-dominated and prominent bio-siliceous deposition. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28624358','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28624358">Environmental drivers of heterogeneity in the trophic-functional structure of protozoan communities during an annual cycle in a coastal ecosystem.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Xu, Guangjian; Yang, Eun Jin; Xu, Henglong 2017-08-15 Trophic-functional groupings are an important biological trait to summarize community structure in functional space. The heterogeneity of the tropic-functional pattern of protozoan communities and its environmental drivers were studied in coastal waters of the Yellow Sea during a 1-year cycle. Samples were collected using the glass slide method at four stations within a water pollution gradient. A second-stage matrix-based analysis was used to summarize spatial variation in the annual pattern of the functional structure. A clustering analysis revealed significant variability in the trophic-functional pattern among the four stations during the 1-year cycle. The heterogeneity in the trophic-functional pattern of the communities was significantly related to changes in environmental variables, particularly ammonium-nitrogen and nitrates, alone or in combination with dissolved oxygen. These results suggest that the heterogeneity in annual patterns of protozoan trophic-functional structure may reflect water quality status in coastal ecosystems. Copyright © 2017. Published by Elsevier Ltd. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27607142','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27607142">Seasonal dynamics in community structure, abundance, body size and sex ratio in two species of Neotropical annual fishes.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Lanés, L E K; Godoy, R S; Maltchik, L; Polačik, M; Blažek, R; Vrtílek, M; Reichard, M 2016-11-01 Seven ephemeral pools on the coastal plain of southern Brazil were found to be inhabited by three annual and 22 non-annual fish species. Two common annual species (Austrolebias minuano and Cynopoecilus fulgens) exhibited clear seasonal dynamics, with the appearance of young fishes in the austral autumn (May to June) and a decline in abundance over the seasonal cycle. The third annual species, Austrolebias wolterstorffii, was rare. No seasonal dynamics were observed in non-annual fishes. The relative abundance of non-annual fishes compared with annual fishes increased over the seasonal cycle, but they coexisted widely. The size structure of annual fishes suggested the presence of a single age cohort in most pools though a second age cohort was registered in one pool in August, coinciding with a large flooding. Strong sexual dimorphism in body size was found in C. fulgens throughout the seasonal cycle, while no sexual dimorphism in body size was found in A. minuano. Female-biased sex ratios were recorded in both common annual fish species in the last three sampling dates (in spring), but not during the first two sampling dates (in winter). The natural lifespan of annual fishes was <8 months. Annual fishes disappeared before habitat desiccation in half of the pools, while non-annual fishes were still present. © 2016 The Fisheries Society of the British Isles. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20180002924&hterms=Remote+sensing&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DRemote%2Bsensing','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20180002924&hterms=Remote+sensing&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DRemote%2Bsensing">On the Ability of Space- Based Passive and Active Remote Sensing Observations of CO2 to Detect Flux Perturbations to the Carbon Cycle</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Crowell, Sean M. R.; Kawa, S. Randolph; Browell, Edward V.; Hammerling, Dorit M.; Moore, Berrien; Schaefer, Kevin; Doney, Scott C. 2018-01-01 Space-borne observations of CO2 are vital to gaining understanding of the carbon cycle in regions of the world that are difficult to measure directly, such as the tropical terrestrial biosphere, the high northern and southern latitudes, and in developing nations such as China. Measurements from passive instruments such as GOSAT (Greenhouse Gases Observing Satellite) and OCO-2 (Orbiting Carbon Observatory 2), however, are constrained by solar zenith angle limitations as well as sensitivity to the presence of clouds and aerosols. Active measurements such as those in development for the Active Sensing of CO2 Emissions over Nights, Days and Seasons (ASCENDS) mission show strong potential for making measurements in the high-latitude winter and in cloudy regions. In this work we examine the enhanced flux constraint provided by the improved coverage from an active measurement such as ASCENDS. The simulation studies presented here show that with sufficient precision, ASCENDS will detect permafrost thaw and fossil fuel emissions shifts at annual and seasonal time scales, even in the presence of transport errors, representativeness errors, and biogenic flux errors. While OCO-2 can detect some of these perturbations at the annual scale, the seasonal sampling provided by ASCENDS provides the stronger constraint. Plain Language Summary: Active and passive remote sensors show the potential to provide unprecedented information on the carbon cycle. With the all-season sampling, active remote sensors are more capable of constraining high-latitude emissions. The reduced sensitivity to cloud and aerosol also makes active sensors more capable of providing information in cloudy and polluted scenes with sufficient accuracy. These experiments account for errors that are fundamental to the top-down approach for constraining emissions, and even including these sources of error, we show that satellite remote sensors are critical for understanding the carbon cycle. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27903428','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27903428">Gonadogenesis and annual reproductive cycles of an endangered cyprinid fish, the lake minnow Eupallasella percnurus (Pallas, 1814).</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Hliwa, Piotr; Król, Jarosław; Sikorska, Justyna; Wolnicki, Jacek; Dietrich, Grzegorz J; Kamiński, Rafał; Stabińska, Agnieszka; Ciereszko, Andrzej 2017-01-01 In this study, gonadogenesis, the effect of temperature (15, 20 and 25°C) on sex differentiation, and annual changes in the gonads of mature lake minnow Eupallasella percnurus (Pallas, 1814) were determined. The lake minnow was found to be a primary gonochoristic fish species, where gonads are formed directly in the ovaries or testes. The morphological differentiation of gonads was initiated 35days post hatch (DPH) when two types of gonadal anlages were visible: a pear-shaped gonad attached by a single mesentery string and a spindle-shaped gonad attached on both sides to the peritoneum. Gonadogenesis occurred faster in females than in males, with the first previtellogenic oocytes and ovarian lamellae being already observed in 45 DPH fish. In males, cytological differentiation occurred approximately 85 DPH, when the fish reached an average body weight of more than 400mg. No significant effect of rearing temperature on sex ratio in lake minnow juveniles was observed. The proportion of males and females was similar (close to 1:1) in all of the thermal-treated groups, although there were effects of temperature on the final sizes of fish. Histological examination of wild, mature lake minnow ovaries during the annual cycle (from May to February the following year) showed asynchronous oocyte maturation. The testes were characteristic of multi-batch spawning fish. Quantitative dominance of spermatids and mature spermatozoa in May was observed, while the presence of primary and secondary spermatocytes in all other periods was confirmed. These changes were also reflected in the seasonal variation in the gonado-somatic index in both sexes, with the highest mean values of 11.2% (females) and 4.0% (males) in May, which were found to be significantly different to all other periods. The data presented in this study provide an important contribution to our understanding of the biology and reproductive strategy of the endangered lake minnow. Copyright © 2016 Elsevier B.V. All </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017BGeo...14.3401S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017BGeo...14.3401S">Reviews and syntheses: Systematic Earth observations for use in terrestrial carbon cycle data assimilation systems</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Scholze, Marko; Buchwitz, Michael; Dorigo, Wouter; Guanter, Luis; Quegan, Shaun 2017-07-01 The global carbon cycle is an important component of the Earth system and it interacts with the hydrology, energy and nutrient cycles as well as ecosystem dynamics. A better understanding of the global carbon cycle is required for improved projections of climate change including corresponding changes in water and food resources and for the verification of measures to reduce anthropogenic greenhouse gas emissions. An improved understanding of the carbon cycle can be achieved by data assimilation systems, which integrate observations relevant to the carbon cycle into coupled carbon, water, energy and nutrient models. Hence, the ingredients for such systems are a carbon cycle model, an algorithm for the assimilation and systematic and well error-characterised observations relevant to the carbon cycle. Relevant observations for assimilation include various in situ measurements in the atmosphere (e.g. concentrations of CO2 and other gases) and on land (e.g. fluxes of carbon water and energy, carbon stocks) as well as remote sensing observations (e.g. atmospheric composition, vegetation and surface properties).We briefly review the different existing data assimilation techniques and contrast them to model benchmarking and evaluation efforts (which also rely on observations). A common requirement for all assimilation techniques is a full description of the observational data properties. Uncertainty estimates of the observations are as important as the observations themselves because they similarly determine the outcome of such assimilation systems. Hence, this article reviews the requirements of data assimilation systems on observations and provides a non-exhaustive overview of current observations and their uncertainties for use in terrestrial carbon cycle data assimilation. We report on progress since the review of model-data synthesis in terrestrial carbon observations by Raupach et al.(2005), emphasising the rapid advance in relevant space-based observations. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1810594P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1810594P">Information transfer across the scales of climate variability: The effect of the 7-8 year cycle on the annual and interannual scales</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Palus, Milan; Jajcay, Nikola; Hlinka, Jaroslav; Kravtsov, Sergey; Tsonis, Anastasios 2016-04-01 Complexity of the climate system stems not only from the fact that it is variable over a huge range of spatial and temporal scales, but also from the nonlinear character of the climate system that leads to interactions of dynamics across scales. The dynamical processes on large time scales influence variability on shorter time scales. This nonlinear phenomenon of cross-scale causal interactions can be observed due to the recently introduced methodology [1] which starts with a wavelet decomposition of a multi-scale signal into quasi-oscillatory modes of a limited bandwidth, described using their instantaneous phases and amplitudes. Then their statistical associations are tested in order to search for interactions across time scales. An information-theoretic formulation of the generalized, nonlinear Granger causality [2] uncovers causal influence and information transfer from large-scale modes of climate variability with characteristic time scales from years to almost a decade to regional temperature variability on short time scales. In analyses of air temperature records from various European locations, a quasioscillatory phenomenon with the period around 7-8 years has been identified as the factor influencing variability of surface air temperature (SAT) on shorter time scales. Its influence on the amplitude of the SAT annual cycle was estimated in the range 0.7-1.4 °C and the effect on the overall variability of the SAT anomalies (SATA) leads to the changes 1.5-1.7 °C in the annual SATA means. The strongest effect of the 7-8 year cycle was observed in the winter SATA means where it reaches 4-5 °C in central European station and reanalysis data [3]. This study is supported by the Ministry of Education, Youth and Sports of the Czech Republic within the Program KONTAKT II, Project No. LH14001. [1] M. Palus, Phys. Rev. Lett. 112 078702 (2014) [2] M. Palus, M. Vejmelka, Phys. Rev. E 75, 056211 (2007) [3] N. Jajcay, J. Hlinka, S. Kravtsov, A. A. Tsonis, M. Palus, Time </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/8085660','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/8085660">Castration and testosterone induced changes in the pinealocytes of roseringed parakeet, Psittacula krameri, during different phases of the annual testicular cycle.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Maitra, S K; Dey, M 1994-08-01 The pinealocytes in male roseringed parakeets (Psittacula krameri) were studied following bilateral castration and/or therapeutic administration of testosterone during the preparatory (June-July), progressive (Nov.-Dec.), pre-breeding (Jan.-Feb.) and breeding (March-April) phases of the annual testicular cycle. The responses of the pineal to either treatment were found to be almost identical throughout the investigation. In each reproductive phase, the pineal appeared to be hypertrophied following castration and the effect was reversed by therapeutic administration of testosterone, while hormonal treatment to the intact parakeets induced regressive changes in the pinealocytes. Collectively, the results of the current study support the hypothesis that the testis through its hormone testosterone exerts inhibitory influences on the activity of pineal, and may thus be considered as being involved in the determination of an inverse relationship between the pineal and the testis during the annual cycle of free-living parakeets. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.H51B1259S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.H51B1259S">Studying Basin Water Balance Variations at Inter- and Intra-annual Time Scales Based On the Budyko Hypothesis and GRACE Gravimetry Satellite Observations</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Shen, H. 2017-12-01 Increasing intensity in global warming and anthropogenic activities has triggered significant changes over regional climates and landscapes, which, in turn, drive the basin water cycle and hydrological balance into a complex and unstable state. Budyko hypothesis is a powerful tool to characterize basin water balance and hydrological variations at long-term average scale. However, due to the absence of basin water storage change, applications of Budyko theory to the inter-annual and intra-annual time scales has been prohibited. The launch of GRACE gavimetry satellites provides a great opportunity to quantify terrestrial water storage change, which can be further introduced into the Budyko hypothesis to reveal the inter- and intra-annual response of basin water components under impacts of climate variability and/or human activities. This research targeted Hai River Basin (in China) and Murray-Darling Basin (in Australia), which have been identified with a continuous groundwater depletion trend as well as impacts by extreme climates in the past decade. This can help us to explore how annual or seasonal precipitation were redistributed to evapotranspiration and runoff via changing basin water storage. Moreover, the impacts of vegetation on annual basin water balance will be re-examined. Our results are expected to provide deep insights about the water cycle and hydrological behaviors for the targeted basins, as well as a proof for a consideration of basin water storage change into the Budyko model at inter- or intra-annual time steps. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20060028190','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20060028190">Annual Cycle of Cloud Forcing of Surface Radiation Budget</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Wilber, Anne C.; Smith, G. Louis; Stackhouse, Paul W., Jr.; Gupta, Shashi K. 2006-01-01 The climate of the Earth is determined by its balance of radiation. The incoming and outgoing radiation fluxes are strongly modulated by clouds, which are not well understood. The Earth Radiation Budget Experiment (Barkstrom and Smith, 1986) provided data from which the effects of clouds on radiation at the top of the atmosphere (TOA) could be computed (Ramanathan, 1987). At TOA, clouds increase the reflected solar radiation, tending to cool the planet, and decrease the OLR, causing the planet to retain its heat (Ramanathan et al., 1989; Harrison et al., 1990). The effects of clouds on radiation fluxes are denoted cloud forcing. These shortwave and longwave forcings counter each other to various degrees, so that in the tropics the result is a near balance. Over mid and polar latitude oceans, cloud forcing at TOA results in large net loss of radiation. Here, there are large areas of stratus clouds and cloud systems associated with storms. These systems are sensitive to surface temperatures and vary strongly with the annual cycle. During winter, anticyclones form over the continents and move to the oceans during summer. This movement of major cloud systems causes large changes of surface radiation, which in turn drives the surface temperature and sensible and latent heat released to the atmosphere. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/52906','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/52906">Using a full annual cycle model to evaluate long-term population viability of the conservation-reliant Kirtland's warbler after successful recovery</a> <a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a> Donald J. Brown; Christine A. Ribic; Deahn M. Donner; Mark D. Nelson; Carol I. Bocetti; Christie M. Deloria-Sheffield; Des Thompson 2017-01-01 Long-term management planning for conservation-reliant migratory songbirds is particularly challenging because habitat quality in different stages and geographic locations of the annual cycle can have direct and carry-over effects that influence the population dynamics. The Neotropical migratory songbird Kirtland's warbler Setophaga kirtlandii... </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.A23D0207M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.A23D0207M">Life Cycle of Tropical Convection and Anvil in Observations and Models</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> McFarlane, S. A.; Hagos, S. M.; Comstock, J. M. 2011-12-01 Tropical convective clouds are important elements of the hydrological cycle and produce extensive cirrus anvils that strongly affect the tropical radiative energy balance. To improve simulations of the global water and energy cycles and accurately predict both precipitation and cloud radiative feedbacks, models need to realistically simulate the lifecycle of tropical convection, including the formation and radiative properties of ice anvil clouds. By combining remote sensing datasets from precipitation and cloud radars at the Atmospheric Radiation Measurement (ARM) Darwin site with geostationary satellite data, we can develop observational understanding of the lifetime of convective systems and the links between the properties of convective systems and their associated anvil clouds. The relationships between convection and anvil in model simulations can then be compared to those seen in the observations to identify areas for improvement in the model simulations. We identify and track tropical convective systems in the Tropical Western Pacific using geostationary satellite observations. We present statistics of the tropical convective systems including size, age, and intensity and classify the lifecycle stage of each system as developing, mature, or dissipating. For systems that cross over the ARM Darwin site, information on convective intensity and anvil properties are obtained from the C-Pol precipitation radar and MMCR cloud radar, respectively, and are examined as a function of the system lifecycle. Initial results from applying the convective identification and tracking algorithm to a tropical simulation from the Weather Research and Forecasting (WRF) model run show that the model produces reasonable overall statistics of convective systems, but details of the life cycle (such as diurnal cycle, system tracks) differ from the observations. Further work will focus on the role of atmospheric temperature and moisture profiles in the model's convective life cycle. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19890062593&hterms=Qbo&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DQbo','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19890062593&hterms=Qbo&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DQbo">Observations and statistical simulations of a proposed solar cycle/QBO/weather relationship</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Baldwin, Mark P.; Dunkerton, Timothy J. 1989-01-01 The 10.7-cm solar flux is observed to be highly correlated with North Pole stratospheric temperatures when partitioned according to the phase of the equatorial stratospheric winds (the quasi-biennial oscillation, or QBO). Calculations show that temperatures over most of the Northern Hemisphere are highly correlated or anticorrelated with North Pole temperatures. The observed spatial pattern of solar-cycle correlations at high latitudes is shown to be not unique to the solar cycle. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23372712','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23372712">Scavengers on the move: behavioural changes in foraging search patterns during the annual cycle.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> López-López, Pascual; Benavent-Corai, José; García-Ripollés, Clara; Urios, Vicente 2013-01-01 Optimal foraging theory predicts that animals will tend to maximize foraging success by optimizing search strategies. However, how organisms detect sparsely distributed food resources remains an open question. When targets are sparse and unpredictably distributed, a Lévy strategy should maximize foraging success. By contrast, when resources are abundant and regularly distributed, simple brownian random movement should be sufficient. Although very different groups of organisms exhibit Lévy motion, the shift from a Lévy to a brownian search strategy has been suggested to depend on internal and external factors such as sex, prey density, or environmental context. However, animal response at the individual level has received little attention. We used GPS satellite-telemetry data of Egyptian vultures Neophron percnopterus to examine movement patterns at the individual level during consecutive years, with particular interest in the variations in foraging search patterns during the different periods of the annual cycle (i.e. breeding vs. non-breeding). Our results show that vultures followed a brownian search strategy in their wintering sojourn in Africa, whereas they exhibited a more complex foraging search pattern at breeding grounds in Europe, including Lévy motion. Interestingly, our results showed that individuals shifted between search strategies within the same period of the annual cycle in successive years. Results could be primarily explained by the different environmental conditions in which foraging activities occur. However, the high degree of behavioural flexibility exhibited during the breeding period in contrast to the non-breeding period is challenging, suggesting that not only environmental conditions explain individuals' behaviour but also individuals' cognitive abilities (e.g., memory effects) could play an important role. Our results support the growing awareness about the role of behavioural flexibility at the individual level, adding new </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRC..121.2405N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRC..121.2405N">Annual cycles of deep-ocean biogeochemical export fluxes in subtropical and subantarctic waters, southwest Pacific Ocean</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Nodder, Scott D.; Chiswell, Stephen M.; Northcote, Lisa C. 2016-04-01 The annual cycles of particle fluxes derived from moored sediment trap data collected during 2000-2012 in subtropical (STW) and subantarctic waters (SAW) east of New Zealand are presented. These observations are the most comprehensive export flux time series from temperate Southern Hemisphere latitudes to date. With high levels of variability, fluxes in SAW were markedly lower than in STW, reflecting the picophytoplankton-dominated communities in the iron-limited, high nutrient-low chlorophyll SAW. Austral spring chlorophyll blooms in surface STW were near synchronous with elevated fluxes of bio-siliceous, carbonate, and organic carbon-rich materials to the deep ocean, probably facilitated by diatom and/or coccolithophorid sedimentation. Lithogenic fluxes were also high in STW, compared to SAW, reflecting proximity to the New Zealand landmass. In contrast, the highest biogenic fluxes in SAW occurred in spring when surface chlorophyll concentrations were low, while highest annual chlorophyll concentrations were in summer with no associated flux increase. We hypothesize that the high spring export in SAW results from subsurface chlorophyll accumulation that is not evident from remote-sensing satellites. This material was also rich in biogenic silica, perhaps related to the preferential export of diatoms and other silica-producing organisms, such as silicoflagellates and radiolarians. Organic carbon fluxes in STW are similar to that of other mesotrophic to oligotrophic waters (˜6-7 mg C m-2 d-1), whereas export from SAW is below the global average (˜3 mg C m-2 d-1). Regional differences in flux across the SW Pacific and Tasman region reflect variations in physical processes and ecosystem structure and function. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.B53C0476C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.B53C0476C">Constraining land carbon cycle process understanding with observations of atmospheric CO2 variability</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Collatz, G. J.; Kawa, S. R.; Liu, Y.; Zeng, F.; Ivanoff, A. 2013-12-01 We evaluate our understanding of the land biospheric carbon cycle by benchmarking a model and its variants to atmospheric CO2 observations and to an atmospheric CO2 inversion. Though the seasonal cycle in CO2 observations is well simulated by the model (RMSE/standard deviation of observations <0.5 at most sites north of 15N and <1 for Southern Hemisphere sites) different model setups suggest that the CO2 seasonal cycle provides some constraint on gross photosynthesis, respiration, and fire fluxes revealed in the amplitude and phase at northern latitude sites. CarbonTracker inversions (CT) and model show similar phasing of the seasonal fluxes but agreement in the amplitude varies by region. We also evaluate interannual variability (IAV) in the measured atmospheric CO2 which, in contrast to the seasonal cycle, is not well represented by the model. We estimate the contributions of biospheric and fire fluxes, and atmospheric transport variability to explaining observed variability in measured CO2. Comparisons with CT show that modeled IAV has some correspondence to the inversion results >40N though fluxes match poorly at regional to continental scales. Regional and global fire emissions are strongly correlated with variability observed at northern flask sample sites and in the global atmospheric CO2 growth rate though in the latter case fire emissions anomalies are not large enough to account fully for the observed variability. We discuss remaining unexplained variability in CO2 observations in terms of the representation of fluxes by the model. This work also demonstrates the limitations of the current network of CO2 observations and the potential of new denser surface measurements and space based column measurements for constraining carbon cycle processes in models. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMSH33A2035S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMSH33A2035S">Radio Imaging Observations of Solar Activity Cycle and Its Anomaly</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Shibasaki, K. 2011-12-01 The 24th solar activity cycle has started and relative sunspot numbers are increasing. However, their rate of increase is rather slow compared to previous cycles. Active region sizes are small, lifetime is short, and big (X-class) flares are rare so far. We study this anomalous situation using data from Nobeyama Radioheliograph (NoRH). Radio imaging observations have been done by NoRH since 1992. Nearly 20 years of daily radio images of the Sun at 17 GHz are used to synthesize a radio butterfly diagram. Due to stable operation of the instrument and a robust calibration method, uniform datasets are available covering the whole period of observation. The radio butterfly diagram shows bright features corresponding to active region belts and their migration toward low latitude as the solar cycle progresses. In the present solar activity cycle (24), increase of radio brightness is delayed and slow. There are also bright features around both poles (polar brightening). Their brightness show solar cycle dependence but peaks around solar minimum. Comparison between the last minimum and the previous one shows decrease of its brightness. This corresponds to weakening of polar magnetic field activity between them. In the northern pole, polar brightening is already weakened in 2011, which means it is close to solar maximum in the northern hemisphere. Southern pole does not show such feature yet. Slow rise of activity in active region belt, weakening of polar activity during the minimum, and large north-south asymmetry in polar activity imply that global solar activity and its synchronization are weakening. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5856959','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5856959">Remote sensing observation of annual dust cycles and possible causality of Kawasaki disease outbreaks in Japan</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> LaHaye, Nick; Linstead, Erik; Sprigg, William A.; Yacoub, Magdi Kawasaki disease (KD) is a rare vascular disease that, if left untreated, can result in irreparable cardiac damage in children. While the symptoms of KD are well-known, as are best practices for treatment, the etiology of the disease and the factors contributing to KD outbreaks remain puzzling to both medical practitioners and scientists alike. Recently, a fungus known as Candida, originating in the farmlands of China, has been blamed for outbreaks in China and Japan, with the hypothesis that it can be transported over long ranges via different wind mechanisms. This paper provides evidence to understand the transport mechanisms of dust at different geographic locations and the cause of the annual spike of KD in Japan. Candida is carried along with many other dusts, particles or aerosols, of various sizes in major seasonal wind currents. The evidence is based upon particle categorization using the Moderate Resolution Imaging Spectrometer (MODIS) Aerosol Optical Depth (AOD), Fine Mode Fraction (FMF) and Ångström Exponent (AE), the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) attenuated backscatter and aerosol subtype, and the Aerosol Robotic Network’s (AERONET) derived volume concentration. We found that seasonality associated with aerosol size distribution at different geographic locations plays a role in identifying dominant abundance at each location. Knowing the typical size of the Candida fungus, and analyzing aerosol characteristics using AERONET data reveals possible particle transport association with KD events at different locations. Thus, understanding transport mechanisms and accurate identification of aerosol sources is important in order to understand possible triggers to outbreaks of KD. This work provides future opportunities to leverage machine learning, including state-of-the-art deep architectures, to build predictive models of KD outbreaks, with the ultimate goal of early forecasting and intervention within a </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active">6</li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_7" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active">7</li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="121"> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70184323','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70184323">Transmission of influenza reflects seasonality of wild birds across the annual cycle</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Hill, Nichola J.; Ma, Eric J.; Meixell, Brandt W.; Lindberg, Mark S.; Boyce, Walter M.; Runstadler, Jonathan A. 2016-01-01 Influenza A Viruses (IAV) in nature must overcome shifting transmission barriers caused by the mobility of their primary host, migratory wild birds, that change throughout the annual cycle. Using a phylogenetic network of viral sequences from North American wild birds (2008–2011) we demonstrate a shift from intraspecific to interspecific transmission that along with reassortment, allows IAV to achieve viral flow across successive seasons from summer to winter. Our study supports amplification of IAV during summer breeding seeded by overwintering virus persisting locally and virus introduced from a wide range of latitudes. As birds migrate from breeding sites to lower latitudes, they become involved in transmission networks with greater connectivity to other bird species, with interspecies transmission of reassortant viruses peaking during the winter. We propose that switching transmission dynamics may be a critical strategy for pathogens that infect mobile hosts inhabiting regions with strong seasonality. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/55389','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/55389">Current systematic carbon-cycle observations and the need for implementing a policy-relevant carbon observing system</a> <a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a> P. Ciais; A. J. Dolman; A. Bombelli; R. Duren; A. Peregon; P. J. Rayner; C. Miller; N. Gobron; G. Kinderman; G. Marland; N. Gruber; F. Chevallier; R. J. Andres; G. Balsamo; L. Bopp; F.-M. Bréon; G. Broquet; R. Dargaville; T. J. Battin; A. Borges; H. Bovensmann; M. Buchwitz; J. Butler; J. G. Canadell; R. B. Cook; R. DeFries; R. Engelen; K. R. Gurney; C. Heinze; M. Heimann; A. Held; M. Henry; B. Law; S. Luyssaert; J. Miller; T. Moriyama; C. Moulin; R. B. Myneni; C. Nussli; M. Obersteiner; D. Ojima; Y. Pan; J.-D. Paris; S. L. Piao; B. Poulter; S. Plummer; S. Quegan; P. Raymond; M. Reichstein; L. Rivier; C. Sabine; D. Schimel; O. Tarasova; R. Valentini; R. Wang; G. van der Werf; D. Wickland; M. Williams; C. Zehner 2014-01-01 A globally integrated carbon observation and analysis system is needed to improve the fundamental understanding of the global carbon cycle, to improve our ability to project future changes, and to verify the effectiveness of policies aiming to reduce greenhouse gas emissions and increase carbon sequestration. Building an integrated carbon observation system requires... </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3944579','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3944579">CHANGES IN THE ANAEROBIC THRESHOLD IN AN ANNUAL CYCLE OF SPORT TRAINING OF YOUNG SOCCER PLAYERS</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> Andrzejewski, M.; Wieczorek, A.; Barinow-Wojewódzki, A.; Jadczak, Ł.; Adrian, S.; Pietrzak, M.; Wieczorek, S. 2013-01-01 The aim of the study was to assess changes in the anaerobic threshold of young soccer players in an annual training cycle. A group of highly trained 15-18 year old players of KKS Lech Poznań were tested. The tests included an annual training macrocycle, and its individual stages resulted from the time structure of the sports training. In order to assess the level of exercise capacities of the players, a field exercise test of increasing intensity was carried out on a soccer pitch. The test made it possible to determine the 4 millimolar lactate threshold (T LA 4 mmol · l-1) on the basis of the lactate concentration in blood [LA], to establish the threshold running speed and the threshold heart rate [HR]. The threshold running speed at the level of the 4 millimolar lactate threshold was established using the two-point form of the equation of a straight line. The obtained indicators of the threshold running speed allowed for precise establishment of effort intensity used in individual training in developing aerobic endurance. In order to test the significance of differences in mean values between four dates of tests, a non-parametric Friedman ANOVA test was used. The significance of differences between consecutive dates of tests was determined using a post-hoc Friedman ANOVA test. The tests showed significant differences in values of selected indicators determined at the anaerobic threshold in various stages of an annual training cycle of young soccer players. The most beneficial changes in terms of the threshold running speed were noted on the fourth date of tests, when the participants had the highest values of 4.01 m · s-1 for older juniors, and 3.80 m · s-1 for younger juniors. This may be indicative of effective application of an individualized programme of training loads and of good preparation of teams for competition in terms of players’ aerobic endurance. PMID:24744480 </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24744480','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24744480">Changes in the anaerobic threshold in an annual cycle of sport training of young soccer players.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Sliwowski, R; Andrzejewski, M; Wieczorek, A; Barinow-Wojewódzki, A; Jadczak, L; Adrian, S; Pietrzak, M; Wieczorek, S 2013-06-01 The aim of the study was to assess changes in the anaerobic threshold of young soccer players in an annual training cycle. A group of highly trained 15-18 year old players of KKS Lech Poznań were tested. The tests included an annual training macrocycle, and its individual stages resulted from the time structure of the sports training. In order to assess the level of exercise capacities of the players, a field exercise test of increasing intensity was carried out on a soccer pitch. The test made it possible to determine the 4 millimolar lactate threshold (T LA 4 mmol · l(-1)) on the basis of the lactate concentration in blood [LA], to establish the threshold running speed and the threshold heart rate [HR]. The threshold running speed at the level of the 4 millimolar lactate threshold was established using the two-point form of the equation of a straight line. The obtained indicators of the threshold running speed allowed for precise establishment of effort intensity used in individual training in developing aerobic endurance. In order to test the significance of differences in mean values between four dates of tests, a non-parametric Friedman ANOVA test was used. The significance of differences between consecutive dates of tests was determined using a post-hoc Friedman ANOVA test. The tests showed significant differences in values of selected indicators determined at the anaerobic threshold in various stages of an annual training cycle of young soccer players. The most beneficial changes in terms of the threshold running speed were noted on the fourth date of tests, when the participants had the highest values of 4.01 m · s(-1) for older juniors, and 3.80 m · s(-1) for younger juniors. This may be indicative of effective application of an individualized programme of training loads and of good preparation of teams for competition in terms of players' aerobic endurance. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100033491','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100033491">Assessment of Global Annual Atmospheric Energy Balance from Satellite Observations</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Lin, Bing; Stackhouse, Paul; Minnis, Patrick; Wielicki, Bruce A.; Hu, Yongxiang; Sun, Wenbo; Fan, Tai-Fang (Alice); Hinkelman, Laura 2008-01-01 Global atmospheric energy balance is one of the fundamental processes for the earth's climate system. This study uses currently available satellite data sets of radiative energy at the top of atmosphere (TOA) and surface and latent and sensible heat over oceans for the year 2000 to assess the global annual energy budget. Over land, surface radiation data are used to constrain assimilated results and to force the radiation, turbulent heat, and heat storage into balance due to a lack of observation-based turbulent heat flux estimations. Global annual means of the TOA net radiation obtained from both direct measurements and calculations are close to zero. The net radiative energy fluxes into the surface and the surface latent heat transported into the atmosphere are about 113 and 86 Watts per square meter, respectively. The estimated atmospheric and surface heat imbalances are about -8 9 Watts per square meter, values that are within the uncertainties of surface radiation and sea surface turbulent flux estimates and likely systematic biases in the analyzed observations. The potential significant additional absorption of solar radiation within the atmosphere suggested by previous studies does not appear to be required to balance the energy budget the spurious heat imbalances in the current data are much smaller (about half) than those obtained previously and debated at about a decade ago. Progress in surface radiation and oceanic turbulent heat flux estimations from satellite measurements significantly reduces the bias errors in the observed global energy budgets of the climate system. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17050209','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17050209">The pineal gland, but not melatonin, is associated with the termination of seasonal testicular activity in an annual reproductive cycle in roseringed parakeet Psittacula krameri.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Sengupta, Anamika; Kumar Maitra, Saumen 2006-01-01 The role of the pineal gland and its hormone melatonin in the regulation of annual testicular events was investigated for the first time in a psittacine bird, the roseringed parakeet (Psittacula krameri). Accordingly, the testicular responsiveness of the birds was evaluated following surgical pinealectomy with or without the exogenous administration of melatonin and the experimental manipulations of the endogenous levels of melatonin through exposing the birds to continuous illumination. An identical schedule was followed during the four reproductive phases, each characterizing a distinct testicular status in the annual cycle, namely, the phases of gametogenic quiescence (preparatory phase), seasonal recovery of gametogenesis (progressive phase), seasonal initiation of sperm formation (pre-breeding phase), and peak gametogenic activity (breeding phase). In each reproductive phase, the birds were subjected to various experimental conditions, and the effects were studied comparing the testicular conditions in the respective control birds. The study included germ cell profiles of the seminiferous tubules, the activities of steroidogenic enzymes 17beta-hydroxysteroid dehydrogenase (17beta-HSD), and Delta(5)3beta-hydroxysteroid dehydrogenase (Delta(5)3beta- HSD) in the testis, and the serum levels of testosterone and melatonin. An analysis of the data reveals that the pineal gland and its hormone melatonin may play an inhibitory role in the development of the testis until the attainment of the seasonal peak in the annual reproductive cycle. However, in all probability, the termination of the seasonal activity of the testis or the initiation of testicular regression in the annual reproductive cycle appears to be the function of the pineal gland, but not of melatonin. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.B32C..07M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.B32C..07M">Methane emission from high-latitude (>50N) lakes: Annual cycle of climatological emissions using satellite-derived lake-ice phenology and freeze-thaw dynamics</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Matthews, E.; Romanski, J.; Du, J.; Watts, J. D. 2017-12-01 Lakes are increasingly recognized as potentially important contributors to global methane emissions despite occupying only a few percent of Earth's ice-free land surface. More than 40% of the global lake area lies in regions of amplified warming north of 50˚N. As with wetlands, lake emissions are sensitive to interannual fluctuations in, e.g., temperature and duration of thaw season. Several estimates of CH4emission from high-latitude lakes have been published but none relies on geospatial lake distributions and satellite-based duration and timing of thaw seasons. We report on a climatology of weekly, spatially-explicit methane emissions from high-latitude lakes. Lake break-up and freeze-up dates for lakes >50km^2 were determined from a lake-ice phenology data set derived from brightness temperature (Tb) observations of space-borne Advanced Microwave Scanning Radiometer (AMSR-E/2) sensors. The lake-ice conditions for smaller lakes were estimated using an Earth System Data Record for Land Surface Freeze-Thaw State derived from Tb observations of Scanning Multichannel Microwave Radiometer (SMMR), Special Sensor Microwave Imager (SSM/I), and SSM/I Sounder (SSMIS). Climatologies encompass 2002-2015 for lake ice phenology and 1979 to 2010 for the land surface freeze-thaw state. Climatologies encompass 2003-2014 for ice phenology and 1979 to 2010 for freeze-thaw dynamics. Length and timing of typical methane-emission periods, derived from the satellite data, were integrated with daily diffusive and ebulliative methane fluxes for lake types following the work of Wik et al. (Nature, 2016) to estimate a full annual cycle of emissions from lakes >50˚N. We explored several approaches to estimate the large bursts of emissions observed over short periods during lake-ice breakup immediately prior to full lake thaw since several studies suggest that a substantial fraction of total annual emissions may occur at this time. While highly uncertain, we plan to investigate whether </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUSM.A43A..05H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUSM.A43A..05H">A vision for an ultra-high resolution integrated water cycle observation and prediction system</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Houser, P. R. 2013-05-01 Society's welfare, progress, and sustainable economic growth—and life itself—depend on the abundance and vigorous cycling and replenishing of water throughout the global environment. The water cycle operates on a continuum of time and space scales and exchanges large amounts of energy as water undergoes phase changes and is moved from one part of the Earth system to another. We must move toward an integrated observation and prediction paradigm that addresses broad local-to-global science and application issues by realizing synergies associated with multiple, coordinated observations and prediction systems. A central challenge of a future water and energy cycle observation strategy is to progress from single variable water-cycle instruments to multivariable integrated instruments in electromagnetic-band families. The microwave range in the electromagnetic spectrum is ideally suited for sensing the state and abundance of water because of water's dielectric properties. Eventually, a dedicated high-resolution water-cycle microwave-based satellite mission may be possible based on large-aperture antenna technology that can harvest the synergy that would be afforded by simultaneous multichannel active and passive microwave measurements. A partial demonstration of these ideas can even be realized with existing microwave satellite observations to support advanced multivariate retrieval methods that can exploit the totality of the microwave spectral information. The simultaneous multichannel active and passive microwave retrieval would allow improved-accuracy retrievals that are not possible with isolated measurements. Furthermore, the simultaneous monitoring of several of the land, atmospheric, oceanic, and cryospheric states brings synergies that will substantially enhance understanding of the global water and energy cycle as a system. The multichannel approach also affords advantages to some constituent retrievals—for instance, simultaneous retrieval of vegetation </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMSA33A2267L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMSA33A2267L">Annual and solar cycle dependencies of SuperDARN scatter occurrence and ionospheric convection measurements</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Lester, M.; Imber, S. M.; Milan, S. E. 2012-12-01 The Super Dual Auroral Radar Network (SuperDARN) provides a long term data series which enables investigations of the coupled magnetosphere-ionosphere system. The network has been in existence essentially since 1995 when 6 radars were operational in the northern hemisphere and 4 in the southern hemisphere. We have been involved in an analysis of the data over the lifetime of the project and present results here from two key studies. In the first study we calculated the amount of ionospheric scatter which is observed by the radars and see clear annual and solar cycle variations in both hemispheres. The recent extended solar minimum also produces a significant effect in the scatter occurrence. In the second study, we have determined the latitude of the Heppner-Maynard Boundary (HMB) using the northern hemisphere SuperDARN radars. The HMB represents the equatorward extent of ionospheric convection for the interval 1996 - 2011. We find that the average latitude of the HMB at midnight is 61° magnetic latitude during solar the maximum of 2003, but it moves significantly poleward during solar minimum, averaging 64° latitude during 1996, and 68° during 2010. This poleward motion is observed despite the increasing number of low latitude radars built in recent years as part of the StormDARN network, and so is not an artefact of data coverage. We believe that the recent extreme solar minimum led to an average HMB location that was further poleward than the previous solar cycle. We have also calculated the Open-Closed field line Boundary (OCB) from auroral images during a subset of the interval (2000 - 2002) and find that on average the HMB is located equatorward of the OCB by ~7o. We suggest that the HMB may be a useful proxy for the OCB when global images are not available. The work presented in this paper has been undertaken as part of the European Cluster Assimilation Technology (ECLAT) project which is funded through the EU FP7 programme and involves groups at </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20150006979&hterms=engine+control&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dengine%2Bcontrol','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20150006979&hterms=engine+control&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dengine%2Bcontrol">Characterizing Observed Limit Cycles in the Cassini Main Engine Guidance Control System</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Rizvi, Farheen; Weitl, Raquel M. 2011-01-01 The Cassini spacecraft dynamics-related telemetry during long Main Engine (ME) burns has indicated the presence of stable limit cycles between 0.03-0.04 Hz frequencies. These stable limit cycles cause the spacecraft to possess non-zero oscillating rates for extended periods of time. This indicates that the linear ME guidance control system does not model the complete dynamics of the spacecraft. In this study, we propose that the observed limit cycles in the spacecraft dynamics telemetry appear from a stable interaction between the unmodeled nonlinear elements in the ME guidance control system. Many nonlinearities in the control system emerge from translating the linear engine gimbal actuator (EGA) motion into a spacecraft rotation. One such nonlinearity comes from the gear backlash in the EGA system, which is the focus of this paper. The limit cycle characteristics and behavior can be predicted by modeling this gear backlash nonlinear element via a describing function and studying the interaction of this describing function with the overall dynamics of the spacecraft. The linear ME guidance controller and gear backlash nonlinearity are modeled analytically. The frequency, magnitude, and nature of the limit cycle are obtained from the frequency response of the ME guidance controller and nonlinear element. In addition, the ME guidance controller along with the nonlinearity is simulated. The simulation response contains a limit cycle with similar characterstics as predicted analytically: 0.03-0.04 Hz frequency and stable, sustained oscillations. The analytical and simulated limit cycle responses are compared to the flight telemetry for long burns such as the Saturn Orbit Insertion and Main Engine Orbit Trim Maneuvers. The analytical and simulated limit cycle characteristics compare well with the actual observed limit cycles in the flight telemetry. Both have frequencies between 0.03-0.04 Hz and stable oscillations. This work shows that the stable limit cycles occur </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1016444-diurnal-cycle-precipitable-water-vapor-over-spain','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1016444-diurnal-cycle-precipitable-water-vapor-over-spain">DIURNAL CYCLE OF PRECIPITABLE WATER VAPOR OVER SPAIN</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Ortiz de Galisteo, J. P.; Cachorro, V. E.; Toledano, C. 2011-05-20 Despite the importance of the diurnal cycle of precipitable water vapor (PWV), its knowledge is very limited due to the lack of data with sufficient temporal resolution. Currently, from GPS receivers, PWV can be obtained with high temporal resolution in all weather conditions for all hours of the day. In this study we have calculated the diurnal cycle of PWV for ten GPS stations over Spain. The minimum value is reached approximately at the same time at all the stations, ~0400-0500 UTC, whereas the maximum is reached in the second half of the day, but with a larger dispersion ofmore » its occurrence between stations. The amplitude of the cycle ranges between 0.72 mm and 1.78 mm. The highest values are recorded at the stations on the Mediterranean coast, with a doubling of the values of the stations on the Atlantic coast or inland. The amplitude of the PWV cycle, relative to the annual mean value, ranges between 8.8 % on the Mediterranean coast and 3.6 % on the Atlantic coast. Two distinctly different seasonal diurnal cycles have been identified, one in winter and other in summer, with spring and autumn being only transition states. The winter cycle is quite similar at all locations, whereas in summer, local effects are felt strongly, making the diurnal cycle quite different between stations. The amplitude of the summer cycle is 1.69 mm, it is almost double the winter one (0.93 mm). Analogous to the annual cycles, the seasonal cycles of the different stations are more similar during the night and early morning hours than during the afternoon. The observed features of the PWV diurnal cycle are explained in a qualitative way on the basis of the air temperature, the transport of moisture by local winds, and the turbulent vertical mixing.« less </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SoPh..290.2117B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SoPh..290.2117B">Mid-Term Quasi-Periodicities and Solar Cycle Variation of the White-Light Corona from 18.5 Years (1996.0 - 2014.5) of LASCO Observations</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Barlyaeva, T.; Lamy, P.; Llebaria, A. 2015-07-01 We report on the analysis of the temporal evolution of the solar corona based on 18.5 years (1996.0 - 2014.5) of white-light observations with the SOHO/LASCO-C2 coronagraph. This evolution is quantified by generating spatially integrated values of the K-corona radiance, first globally, then in latitudinal sectors. The analysis considers time series of monthly values and 13-month running means of the radiance as well as several indices and proxies of solar activity. We study correlation, wavelet time-frequency spectra, and cross-coherence and phase spectra between these quantities. Our results give a detailed insight on how the corona responds to solar activity over timescales ranging from mid-term quasi-periodicities (also known as quasi-biennial oscillations or QBOs) to the long-term 11 year solar cycle. The amplitude of the variation between successive solar maxima and minima (modulation factor) very much depends upon the strength of the cycle and upon the heliographic latitude. An asymmetry is observed during the ascending phase of Solar Cycle 24, prominently in the royal and polar sectors, with north leading. Most prominent QBOs are a quasi-annual period during the maximum phase of Solar Cycle 23 and a shorter period, seven to eight months, in the ascending and maximum phases of Solar Cycle 24. They share the same properties as the solar QBOs: variable periodicity, intermittency, asymmetric development in the northern and southern solar hemispheres, and largest amplitudes during the maximum phase of solar cycles. The strongest correlation of the temporal variations of the coronal radiance - and consequently the coronal electron density - is found with the total magnetic flux. Considering that the morphology of the solar corona is also directly controlled by the topology of the magnetic field, this correlation reinforces the view that they are intimately connected, including their variability at all timescales. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20170008030','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20170008030">Solar Spectral Irradiance Variability in Cycle 24: Model Predictions and OMI Observations</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Marchenko, S.; DeLand, M.; Lean, J. 2016-01-01 Utilizing the excellent stability of the Ozone Monitoring Instrument (OMI), we characterize both short-term (solar rotation) and long-term (solar cycle) changes of the solar spectral irradiance (SSI) between 265-500 nanometers during the ongoing Cycle 24. We supplement the OMI data with concurrent observations from the GOME-2 (Global Ozone Monitoring Experiment - 2) and SORCE (Solar Radiation and Climate Experiment) instruments and find fair-to-excellent agreement between the observations and predictions of the NRLSSI2 (Naval Research Laboratory Solar Spectral Irradiance - post SORCE) and SATIRE-S (the Naval Research Laboratory's Spectral And Total Irradiance REconstruction for the Satellite era) models. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSAH21A..05M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSAH21A..05M">Future ocean hypercapnia driven by anthropogenic amplification of the natural CO2 cycle</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> McNeil, B. 2016-02-01 Elevated carbon dioxide concentrations in seawater (hypercapnia) can induce neurological, physiological and behavioural deficiencies in marine animals. Prediction of the onset and evolution of hypercapnia in the ocean requires a good understanding of annual oceanic carbon dioxide variability, but relevant global observational data are sparse. Here we diagnose global ocean patterns of monthly carbon variability based on observations that allow us to examine the evolution of surface ocean CO2 levels over the entire annual cycle under increasing atmospheric CO2 concentrations. We find that some oceanic regions undergo an up to 10-fold amplification of the natural cycle of CO2 by 2100, if atmospheric carbon dioxide concentrations continue to rise throughout this century (RCP8.5). Projections from a suite of Earth System Climate Models are broadly consistent with the findings from our data based approach. Our predicted amplification in the annual CO2 cycle displays distinct global patterns that may expose major fisheries in the Southern, Pacific and North Atlantic Oceans to high CO2 events many decades earlier than expected from average atmospheric CO2 concentrations. We suggest that these ocean 'CO2 hotspots' evolve as a combination of the strong seasonal dynamics of CO2 and the long-term effective storage of anthropogenic CO2 that lowers the buffer capacity in those regions, causing a non-linear CO2 amplification over the annual cycle. The onset of ocean hypercapnia events (pCO2 >1000 µatm) is forecast for atmospheric CO2 concentrations that exceed 650 ppm, with hypercapnia spreading to up to one half of the surface ocean by the year 2100 under a high-emissions scenario (RCP8.5) with potential implications for fisheries over the coming century. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20060043976&hterms=water+sensor&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dwater%2Bsensor','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20060043976&hterms=water+sensor&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dwater%2Bsensor">Land surface water cycles observed with satellite sensors</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Nghiem, Son V.; Njoku, E. G.; Brakenridge, G. R.; Kim, Y. 2005-01-01 Acceleration of the global water cycle may lead to increased global precipitation, faster evaporation and a consequent exacerbation of hydrologic extreme. In the U.S. national assessment of the potential consequences of climate variability and change, two GCMs (CGCM1 and HadCM2) show a large increase in precipitation in the future over the southwestern U.S. particularly during winter (Felzer and Heard, 1999). Increased precipitation potentially has important impacts on agricultural and water use in the southeast U.S. (Hatch et al., 1999) and in the central Great Plains (Nielsen, 1997). A hurricane model predicts a 40% precipitation increase for severe hurricanes affecting southeastern Florida, which provokes substantially greater flooding that could negate most of the benefits of present water-management practices in this basin (Gutowski et al., 1994). Thus, it is important to observe the hydroclimate on a continuous longterm basis to address the question of increased precipitation in the enhanced water cycle. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080022945','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080022945">On the Relationship Between Solar Wind Speed, Geomagnetic Activity, and the Solar Cycle Using Annual Values</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Wilson, Robert M.; Hathaway, David H. 2008-01-01 The aa index can be decomposed into two separate components: the leading sporadic component due to solar activity as measured by sunspot number and the residual or recurrent component due to interplanetary disturbances, such as coronal holes. For the interval 1964-2006, a highly statistically important correlation (r = 0.749) is found between annual averages of the aa index and the solar wind speed (especially between the residual component of aa and the solar wind speed, r = 0.865). Because cyclic averages of aa (and the residual component) have trended upward during cycles 11-23, cyclic averages of solar wind speed are inferred to have also trended upward. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001DSRII..48.1285K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001DSRII..48.1285K">An annual cycle of phytoplankton biomass in the Arabian Sea, 1994 1995, as determined by moored optical sensors</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Kinkade, C. S.; Marra, J.; Dickey, T. D.; Weller, R. A surface-to-bottom mooring in the central Arabian Sea (15.5°N, 61.5°E) deployed from October 1994 to October 1995, included fluorometers, PAR irradiance sensors, Lu 683 sensors, and a spectral radiometer. An annual cycle of phytoplankton biomass was determined by transforming signals from the optical sensors into chlorophyll a (chl a). Half-yearly phytoplankton blooms with water-column stratification were observed near the end of each monsoon, as well as biomass increases in response to mesoscale flow features. During the Northeast Monsoon, the integrate water-column chl a rose from 15 to 25 mg m -2, while during the Southwest Monsoon, chl a increased from 15 to a maximum >40 mg m -2. We present an empirical relationship between the ratio of downwelling Ed443/ Ed550 (blue to green wavelength ratio) and integral euphotic zone chl a determined by moored fluorometers ( r2=0.73). There is a more significant relationship between Ed443/ Ed550 measured at one depth in the water column (65 m) and the average vertical attenuation coefficient for PAR (K PAR) between 0 and 65 m ( r2=0.845). Because biofouling was a significant problem at times, data return from any one sensor was incomplete. However, optical sensor/data intercomparison helped fill gaps while permitting investigation of the temporal variability in observed phytoplankton biomass. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=business+AND+cycle&id=EJ771297','ERIC'); return false;" href="https://eric.ed.gov/?q=business+AND+cycle&id=EJ771297">Loglinear Approximate Solutions to Real-Business-Cycle Models: Some Observations</a> <a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a> Lau, Sau-Him Paul; Ng, Philip Hoi-Tak 2007-01-01 Following the analytical approach suggested in Campbell, the authors consider a baseline real-business-cycle (RBC) model with endogenous labor supply. They observe that the coefficients in the loglinear approximation of the dynamic equations characterizing the equilibrium are related to the fundamental parameters in a relatively simple manner.… </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AAS...23131505K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AAS...23131505K">Helioseismic Observations of Two Solar Cycles and Constraints on Dynamo Theory</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Kosovichev, Alexander 2018-01-01 Helioseismology data from the SOHO and SDO, obtained in 1996-2017 for almost two solar cycles, provide a unique opportunity to investigate variations of the solar interior structure and dynamics, and link these variations to the current dynamo models and simulations. The solar oscillation frequencies and frequency splitting of medium-degree p- and f-modes, as well as helioseismic inversions have been used to analyze variations of the differential rotation (“torsional oscillations”) and the global asphericity. By comparing the helioseismology results with the synoptic surface magnetic fields we identify characteristic changes associated the initiation and evolution of the solar cycles, 23 and 24. The observational results are compared with the current mean-field dynamo models and 3D MHD dynamo simulations. It is shown that the helioseismology inferences provide important constraints on the dynamics of the tachocline and near-surface shear layer, and also may explain the fundamental difference between the two solar cycles and detect the onset of the next cycle. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.5096H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.5096H">Annual and inter-annual variations of 6.5-day-planetary-waves in MLT observed by TIMED/SABER</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Huang, Yingying; Li, Huijun; Li, Chongyin; Zhang, Shaodong 2017-04-01 Annual and inter-annual variations of 6.5DWs in 20-110 km, 52°S-52°N, 2002-2016 are studied by using v2.0 TIMED/SABER kinetic temperature data. Firstly, global annual variations of 6.5DW's spectral power and amplitudes are obtained. Strong wave amplitudes emerge in 30°S/N-50°S/N, and peaks in altitude separate in stratosphere (40-50 km), mesosphere (80-90 km) and the lower thermosphere (100-110 km), respectively. Their annual variations are similar in both hemispheres, but different in altitude. In 40-50 km, the annual maximums emerge mostly in winters: Dec.-Jan. in the NH and Jul.-Aug. in the SH. In MLT, annual peaks arise twice in each half of year. In 80-90 km, they're mainly in equinoctial seasons and winters: May, Aug.-Sep. and Jan. in the NH and Feb., Nov. and May in the SH. In 100-110 km, they emerge mainly in equinoctial seasons: Apr.-May and Aug.-Sep. in the NH and Feb.-Mar. and Oct.-Nov. in the SH. Then, inter-annual variations of 6.5DW amplitudes during the 14-year period are studied. Frequency spectra of monthly-mean amplitudes show that, main dynamics in long-term variations of 6.5DWs are AO and SAO in both hemispheres. Besides, QBO are visible in both hemispheres and 4-month period signals are noticed in the NH in MLT. Amplitudes of SAO, AO and QBO are obtained by bandpass filter. Their amplitudes are comparable in stratosphere and mesosphere, and QBO signals are weaker than the others in the LT. Vertical variations both of SAO and AO amplitudes are very stable. AO structures have little inter-annual changes, while inter-annual variations of SAO are significant and are related with 6.5DW. It means that annual and inter-annual variations of 6.5DW are mainly controlled by AO and SAO, respectively. Although QBO signals are weaker and their variations are less regular than AO and SAO, their phases seems to relate with inter-annual variations of 6.5DW as well. </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active">7</li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_8" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active">8</li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="141"> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1980hwi..reptS.....','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1980hwi..reptS.....">Economic evaluation of the Annual Cycle Energy System (ACES). Volume 1: Executive summary</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> 1980-05-01 Three different classes of building are investigated, namely: single family residence; multifamily residence; and commercial office building. For each building type in each geographic location, the economic evaluation of the annual cycle energy system (ACES) is based on a comparison of the present worth of the ACES to the present worth of a number of conventional systems. The results of this analysis indicate that the economic viability of the ACES is very sensitive to the assumed value of the property tax, maintenance cost, and fuel escalation rates, while it is relatively insensitive to the assumed values of other parameters. Fortunately, any conceivable change in the fuel escalation rates would tend to increase the viability of the ACES concept. An increase in the assumed value of the maintenance cost or property tax would tend to make the ACES concept less viable; a decrease in either would tend to make the ACES concept more viable. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMPP21C1269A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMPP21C1269A">Understanding the dust cycle at high latitudes: integrating models and observations</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Albani, S.; Mahowald, N. M.; Maggi, V.; Delmonte, B.; Winckler, G.; Potenza, M. A. C.; Baccolo, G.; Balkanski, Y. 2017-12-01 Changing climate conditions affect dust emissions and the global dust cycle, which in turn affects climate and biogeochemistry. Paleodust archives from land, ocean, and ice sheets preserve the history of dust deposition for a range of spatial scales from close to the major hemispheric sources to remote sinks such as the polar ice sheets. In each hemisphere common features on the glacial-interglacial time scale mark the baseline evolution of the dust cycle, and inspired the hypothesis that increased dust deposition to ocean stimulated the glacial biological pump contributing to the reduction of atmospheric carbon dioxide levels. On the other hand finer geographical and temporal scales features are superposed to these glacial-interglacial trends, providing the chance of a more sophisticated understanding of the dust cycle, for instance allowing distinctions in terms of source availability or transport patterns as recorded by different records. As such paleodust archives can prove invaluable sources of information, especially when characterized by a quantitative estimation of the mass accumulation rates, and interpreted in connection with climate models. We review our past work and present ongoing research showing how climate models can help in the interpretation of paleodust records, as well as the potential of the same observations for constraining the representation of the global dust cycle embedded in Earth System Models, both in terms of magnitude and physical parameters related to particle sizes and optical properties. Finally we show the impacts on climate, based on this kind of observationally constrained model simulations. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AtmEn.105..138H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AtmEn.105..138H">Diurnal, seasonal, and annual trends in atmospheric CO2 at southwest London during 2000-2012: Wind sector analysis and comparison with Mace Head, Ireland</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Hernández-Paniagua, Iván Y.; Lowry, David; Clemitshaw, Kevin C.; Fisher, Rebecca E.; France, James L.; Lanoisellé, Mathias; Ramonet, Michel; Nisbet, Euan G. 2015-03-01 In-situ measurements of atmospheric CO2 have been made at Royal Holloway University of London (RHUL) in Egham (EGH), Surrey, UK from 2000 to 2012. The data were linked to the global scale using NOAA-calibrated gases. Measured CO2 varies on time scales that range from minutes to inter-annual and annual cycles. Seasonality and pollution episodes occur each year. Diurnal cycles vary with daylight and temperature, which influence the biological cycle of CO2 and the degree of vertical mixing. Anthropogenic emissions of CO2 dominate the variability during weekdays when transport cycles are greater than at weekends. Seasonal cycles are driven by temporal variations in biological activity and changes in combustion emissions. Maximum mole fractions (μmol/mol) (henceforth referred to by parts per million, ppm) occur in winter, with minima in late summer. The smallest seasonal amplitude observed, peak to trough, was 17.0 ppm CO2 in 2003, whereas the largest amplitude observed was 27.1 ppm CO2 in 2008. Meteorology can strongly modify the CO2 mole fractions at different time scales. Analysis of eight 45° wind sectors shows that the highest CO2 mole fractions were recorded from the E and SE sectors. Lowest mole fractions were observed for air masses from the S and SW. Back-trajectory and meteorological analyses of the data confirm that the dominant sources of CO2 are anthropogenic emissions from London and SE England. The largest annual rate of increase in the annual average of CO2, 3.26 ppm yr-1 (p < 0.05), was for the W sector with a smaller increase, 2.56 ppm yr-1 (p < 0.05), for the E sector. Calm winds showed an annual growth rate of 1.16 ppm yr-1 CO2 (p < 0.05) implying declining local sources. The EGH site shows an average growth rate of 2.5 ppm yr-1 CO2 (p < 0.05) over the measured period, which exceeds the observed global trend and contrasts with the decrease in CO2 emissions reported in UK greenhouse gas inventories. This is presumably because the region has had </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/21313770-solar-cycle-lost-early-sunspot-observations-resolve-old-mystery','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/21313770-solar-cycle-lost-early-sunspot-observations-resolve-old-mystery">A SOLAR CYCLE LOST IN 1793-1800: EARLY SUNSPOT OBSERVATIONS RESOLVE THE OLD MYSTERY</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Usoskin, Ilya G.; Mursula, Kalevi; Arlt, Rainer 2009-08-01 Because of the lack of reliable sunspot observations, the quality of the sunspot number series is poor in the late 18th century, leading to the abnormally long solar cycle (1784-1799) before the Dalton minimum. Using the newly recovered solar drawings by the 18-19th century observers Staudacher and Hamilton, we construct the solar butterfly diagram, i.e., the latitudinal distribution of sunspots in the 1790s. The sudden, systematic occurrence of sunspots at high solar latitudes in 1793-1796 unambiguously shows that a new cycle started in 1793, which was lost in the traditional Wolf sunspot series. This finally confirms the existence of themore » lost cycle that has been proposed earlier, thus resolving an old mystery. This Letter brings the attention of the scientific community to the need of revising the sunspot series in the 18th century. The presence of a new short, asymmetric cycle implies changes and constraints to sunspot cycle statistics, solar activity predictions, and solar dynamo theories, as well as for solar-terrestrial relations.« less </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title50-vol9/pdf/CFR-2011-title50-vol9-sec222-402.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title50-vol9/pdf/CFR-2011-title50-vol9-sec222-402.pdf">50 CFR 222.402 - Annual determination of fisheries to be observed; notice and comment.</a> <a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a> 2011-10-01 ... 50 Wildlife and Fisheries 9 2011-10-01 2011-10-01 false Annual determination of fisheries to be observed; notice and comment. 222.402 Section 222.402 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS GENERAL... </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title50-vol10/pdf/CFR-2012-title50-vol10-sec222-402.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title50-vol10/pdf/CFR-2012-title50-vol10-sec222-402.pdf">50 CFR 222.402 - Annual determination of fisheries to be observed; notice and comment.</a> <a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a> 2012-10-01 ... 50 Wildlife and Fisheries 10 2012-10-01 2012-10-01 false Annual determination of fisheries to be observed; notice and comment. 222.402 Section 222.402 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS GENERAL... </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70187244','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70187244">Using a full annual cycle model to evaluate long-term population viability of the conservation-reliant Kirtland's warbler after successful recovery</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Brown, Donald J.; Ribic, Christine; Donner, Deahn M.; Nelson, Mark D.; Bocetti, Carol I.; Deloria-Sheffield, Christie M. 2017-01-01 Long-term management planning for conservation-reliant migratory songbirds is particularly challenging because habitat quality in different stages and geographic locations of the annual cycle can have direct and carry-over effects that influence the population dynamics. The Neotropical migratory songbird Kirtland's warbler Setophaga kirtlandii (Baird 1852) is listed as endangered under the U.S. Endangered Species Act and Near Threatened under the IUCN Red List. This conservation-reliant species is being considered for U.S. federal delisting because the species has surpassed the designated 1000 breeding pairs recovery threshold since 2001.To help inform the delisting decision and long-term management efforts, we developed a population simulation model for the Kirtland's warbler that incorporated both breeding and wintering grounds habitat dynamics, and projected population viability based on current environmental conditions and potential future management scenarios. Future management scenarios included the continuation of current management conditions, reduced productivity and carrying capacity due to the changes in habitat suitability from the creation of experimental jack pine Pinus banksiana (Lamb.) plantations, and reduced productivity from alteration of the brown-headed cowbird Molothrus ater (Boddaert 1783) removal programme.Linking wintering grounds precipitation to productivity improved the accuracy of the model for replicating past observed population dynamics. Our future simulations indicate that the Kirtland's warbler population is stable under two potential future management scenarios: (i) continuation of current management practices and (ii) spatially restricting cowbird removal to the core breeding area, assuming that cowbirds reduce productivity in the remaining patches by ≤41%. The additional future management scenarios we assessed resulted in population declines.Synthesis and applications. Our study indicates that the Kirtland's warbler population </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22317330','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22317330">Study of biomechanical overload in urban gardeners of Barcelona: application of analytical models for risk exposure evaluation in annual working cycle.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Alvarez-Casado, Enrique; Hernandez-Soto, Aquiles; Tello, Sandoval; Gual, Rosa 2012-01-01 Occupational musculoskeletal disorders in the upper limbs and its consequences on the impact and prevalence in the work force are subject of many investigations in almost all the production fields. However, the exposure to this kind of risk factor on urban gardeners has not been well studied so far. The kind of plant varieties used in the parks, the tools that they use, as much as the necessary actions for the maintenance of the park, have an impact on the biomechanical overload of the upper limbs. Additionally, the analysis of the exposure to the biomechanical overload on upper limbs in gardening work is a complex task, mainly because it is an activity highly variable and of annual cycle. For this reason an analytical model for risk exposure evaluation is necessary. During this research the work activity of 29 gardeners in 3 urban parks of Barcelona has been analyzed. Each park has a specific acting plan, in relation with the quantity and the typology of vegetal species, its classification and the season of the year. Work and observation and video recording sessions on-site were conducted. The video-graphic registration was done on workers without any prior musculoskeletal disorder and with a minimum labour experience of 5 years. Moreover, the analysis of saturation time, considered as the relation of the repetitive working hours in reference with the hours of effective work was done. Using the registered tasks on video, the biomechanical overload on upper limbs applying the OCRA Checklist method was analyzed. A methodological procedure to analyze the risk exposure in annual working cycle has been proposed. The results that we got allow us to get information that can help in the assignment of the tasks and in the training of staff, as well as in the recommendations of the urban landscape's design. All these aspects have the goal to decrease the risk to develop work-related musculoskeletal disorders. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=Time+AND+series+AND+design+AND+approach&pg=3&id=EJ1079354','ERIC'); return false;" href="https://eric.ed.gov/?q=Time+AND+series+AND+design+AND+approach&pg=3&id=EJ1079354">Students' Understanding of Analogy after a Core (Chemical Observations, Representations, Experimentation) Learning Cycle, General Chemistry Experiment</a> <a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a> Avargil, Shirly; Bruce, Mitchell R. M.; Amar, Franc¸ois G.; Bruce, Alice E. 2015-01-01 Students' understanding about analogy was investigated after a CORE learning cycle general chemistry experiment. CORE (Chemical Observations, Representations, Experimentation) is a new three-phase learning cycle that involves (phase 1) guiding students through chemical observations while they consider a series of open-ended questions, (phase 2)… </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.A33C2376Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.A33C2376Y">Projected Changes in the Annual Cycle of Precipitation over Central Asia by CMIP5 Models</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Yu, X.; Zhao, Y. 2017-12-01 Future changes in the annual cycle of the precipitation in central Asia (CA) were estimated based on the historical and Representative Concentration Pathway 8.5 (RCP8.5) experiments from 25 models of the Coupled Model Intercomparison Project phase 5 (CMIP5). Compared with the Global Precipitation Climatology Project (GPCP) observations, the historical (1979-1999) experiments showed that most models can capture the migration of rainfall centers, but remarkable discrepancies exist in the location and intensity of rainfall centers between simulations and observations. Considering the skill scores of precipitation and pattern correlations of circulations, which are closely related to the precipitation for each month, for the 25 models, the four best models (e.g., CanESM2, CMCC-CMS, MIROC5 and MPI-ESM-LR) with relatively good performance were selected. The four models' ensemble mean indicated that the migration and location of the precipitation centers were better reproduced, except the intensity of the centers was overestimated, compared with the result that only considered precipitation. Based on the four best models' ensemble mean under RCP8.5 scenarios, precipitation was projected to increase dramatically over most of the CA region in the boreal cold seasons (November, December, January, February, March, April and May) with the maximum in December in the end of twenty-first century (2079-2099), and several positive centers were located in the Pamirs Plateau and the Tianshan Mountains. By contrast, the precipitation changes were weak in the boreal warm seasons (June, July, August, September and October), with a wet center located in the northern Himalayas. Furthermore, there remain some uncertainties in the projected precipitation regions and periods obtained by comparing models' ensemble results of this paper and the results of previous studies. These uncertainties should be investigated in future work. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.H12C..06W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.H12C..06W">Can we Observe and Assess Whether the Global Hydrological Cycle is "Intensifying"?</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Wood, E. F.; Sheffield, J. 2012-12-01 There is controversy over whether the hydrological cycle is "intensifying" (or "accelerating"), and if so how and where? Resolving this critical question is a central goal of both national (e.g. NASA's Energy and Water cycle Study: NEWS) and international (WCRP Global Energy and Water cycle Experiment: GEWEX) programs. Its resolution has significant implications for understanding changes in hydroclimatic states and variability, and in future water security at regional to global scales. Over the last decade a number of papers have addressed trends and change in specific water cycle variables with results that can best be described as inconclusive, regardless of the conclusions of specific papers. In this presentation a number of recent studies will be reviewed for their consistency in assessing whether collectively one can make conclusions regarding how the hydrologic cycle is changing. The presentation will also demonstrate a pathway for analyzing where to observe for the detection of change based on a NASA-supported, global, 1983-2009, terrestrial water cycle Earth System Data Record project being led by the author. Initial results will be presented and a discussion presented on the extent that the proposed strategy can be used to detect change in the terrestrial hydrological cycle. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/sciencecinema/biblio/1060283','SCIGOVIMAGE-SCICINEMA'); return false;" href="http://www.osti.gov/sciencecinema/biblio/1060283">Omics in the Arctic: Genome-enabled Contributions to Carbon Cycle Research in High-Latitude Ecosystems (JGI Seventh Annual User Meeting 2012: Genomics of Energy and Environment)</a> <a target="_blank" href="http://www.osti.gov/sciencecinema/">ScienceCinema</a> Wullschleger, Stan 2018-02-13 Stan Wullschleger of Oak Ridge National Laboratory on "Omics in the Arctic: Genome-enabled Contributions to Carbon Cycle Research in High-Latitude Ecosystems" on March 22, 2012 at the 7th Annual Genomics of Energy & Environment Meeting in Walnut Creek, California. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ECSS..181..170C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ECSS..181..170C">Annual cycle and spatial trends in fatty acid composition of suspended particulate organic matter across the Beaufort Sea shelf</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Connelly, Tara L.; Businski, Tara N.; Deibel, Don; Parrish, Christopher C.; Trela, Piotr 2016-11-01 Fatty acid profiles of suspended particulate organic matter (POM) were determined over an annual cycle (September 2003 to August 2004) on the Beaufort Sea shelf, Canadian Arctic. Special emphasis was placed on the nutritional quality of the fatty acid pool available to zooplankton by examining spatial and temporal patterns in the proportions of total polyunsaturated fatty acids (PUFA) and the essential fatty acids 22:6n-3 (DHA) and 20:5n-3 (EPA). EPA and DHA were the two most abundant PUFA throughout the study period. A log-ratio multivariate (LRA) analysis revealed strong structure in fatty acid profiles related to season and depth. Dominant fatty acids accounting for the observed trend included 18:5n-3, 18:4n-3, 16:1n-7, 20:5n-3, 18:0 and 20:3n-3. We observed a shift in fatty acid profiles from summer to autumn (e.g., from 16:1n-7 and EPA to 18:5n-3 and 18:4n-3) that likely corresponded to a shift in the relative importance of diatoms versus dinoflagellates, prymnesiophytes and/or prasinophytes to the POM pool. Fatty acid composition during winter was dominated by more refractory saturated fatty acids. A surprising finding was the depth and seasonal trend of 20:3n-3, which was higher in winter, aligned with 18:0 in the LRA, but behaved differently than other n-3 PUFA. We interpret fatty acid profiles during summer to be predominantly driven by phytoplankton inputs, whereas fatty acid profiles in winter were dominated by fatty acids that were left over after consumption and/or were generated by heterotrophs. The highest diatom inputs (EPA, the diatom fatty acid marker), n-3/n-6 ratios, and C16 PUFA index were located in an upwelling region off Cape Bathurst. This study is the first annual time series of fatty acid profiles of POM in Arctic seas, expanding our knowledge of the composition of POM throughout the dark season. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18263898','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18263898">Apple dwarfing rootstocks and interstocks affect the type of growth units produced during the annual growth cycle: precocious transition to flowering affects the composition and vigour of annual shoots.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Seleznyova, Alla N; Tustin, D Stuart; Thorp, T Grant 2008-04-01 Precocious flowering in apple trees is often associated with a smaller tree size. The hypothesis was tested that floral evocation in axillary buds, induced by dwarfing rootstocks, reduces the vigour of annual shoots developing from these buds compared with shoots developing from vegetative buds. The experimental system provided a wide range of possible tree vigour using 'Royal Gala' scions and M.9 (dwarfing) and MM.106 (non-dwarfing) as rootstocks and interstocks. Second-year annual shoots were divided into growth units corresponding to periods (flushes) of growth namely, vegetative spur, extension growth unit, uninterrupted growth unit, floral growth unit (bourse) and extended bourse. The differences between the floral and vegetative shoots were quantified by the constituent growth units produced. The dwarfing influence was expressed, firstly, in reduced proportions of shoots that contained at least one extension growth unit and secondly, in reduced proportions of bicyclic shoots (containing two extension growth units) and shoots with an uninterrupted growth unit. In treatments where floral shoots were present, they were markedly less vigorous than vegetative shoots with respect to both measures. In treatments with M.9 rootstock, vegetative and floral shoots produced on average 0.52 and 0.17 extension growth units, compared with 0.77 extension growth units per shoot in the MM.106 rootstock treatment. Remarkably, the number of nodes per extension growth unit was not affected by the rootstock/interstock treatments. These results showed that rootstocks/interstocks affect the type of growth units produced during the annual growth cycle, reducing the number of extension growth units, thus affecting the composition and vigour of annual shoots. This effect is particularly amplified by the transition to flowering induced by dwarfing rootstocks. The division of annual shoot into growth units will also be useful for measuring and modelling effects of age on apple tree </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950029610&hterms=Phytoplankton&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DPhytoplankton','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950029610&hterms=Phytoplankton&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DPhytoplankton">Annual and interannual variations of phytoplankton pigment concentration and upwelling along the Pacific equator</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Halpern, David; Feldman, Gene C. 1994-01-01 The following variables along the Pacific equator from 145 deg E to 95 deg W were employed: surface layer phytoplankton pigment concentrations derived from Nimbus 7 coastal zone color scanner (CZCS) measurements of ocean color radiances; vertical velocities simulated at the 90-m bottom of the euphotic layer from a wind-driven ocean general circulation model; and nitrate concentrations estimated from model-simulated temperature. The upward flux of nitrate into the euphotic layer was calculated from the simulated vertical motion and nitrate concentration. The CZCS-derived phytoplankton pigment concentration was uniform from 175 deg to 95 deg W. Longitudinal profiles of upwelling, phytoplankton biomass, and 90-m nitrate flux were of different shapes. The small annual cycles of the phytoplankton pigment and nitrate flux were in phase: increased phytoplankton biomass was associated with increased upward nitrate flux, but the phase was not consistent with the annual cycles of the easterly wind or of the upwelling intensity. Variation of phytoplankton pigment concentration was greater during El Nino than during the annual cycle. The substantially reduced phytoplankton pigment concentration observed during El Nino was associated with smaller upward nitrate flux. Phytoplankton biomass during non-El Nino conditions was not related to nitrate flux into the euphotic layer. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMGC33C1252H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMGC33C1252H">Terrestrial water cycle induced meridional overturning circulation variability over the Atlantic Ocean</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Hsu, C. W.; Velicogna, I. 2016-12-01 Terrestrial water cycle has a significant role in the long-term changes of Atlantic meridional overturning circulation (AMOC). With the fresh water input over the ocean from the river runoff or ice melting at the higher latitude, AMOC transport has been predicted to slow down at the end of the century. We compare ocean bottom pressure measured from the GRACE satellite data with the conventional density derived transport observations from the RAPID MOC/MOCHA array to study the impact of the terrestrial water cycle on the seasonal and inter annual AMOC variability detected by the RAPID MOC/MOCHA array observations. We propose that the observed short-term variability is due to coupling of wind driven and terrestrial water cycle changes. We show that the proposed mechanism explains a significant portion of the transport variance and we present new possible mechanism that can explain the residual transport signal in AMOC. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140000832','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140000832">Estimating the Mean Annual Surface Air Temperature at Armagh Observatory, Northern Ireland, and the Global Land-Ocean Temperature Index for Sunspot Cycle 24, the Current Ongoing Sunspot Cycle</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Wilson, Robert M. 2013-01-01 As noted by Gray et al., Sir William Herschel was the first to suggest a possible close connection between the Sun and the Earth’s climate. The Sun, being the source of energy that impacts and drives the Earth’s climate system, displays a variety of changes over both short and long term time scales, the most obvious examples being the somewhat regular waxing and waning of sunspots with time (i.e., the sunspot cycle (SC)), first described by Samuel Heinrich Schwabe, a German apothecary and amateur astronomer who observed the Sun from Dessau, Germany, and the now well established variation of the Sun’s irradiance over the SC. Other factors related to the SC have been linked to changes in climate as well. Some of these other factors include the role of cosmic rays and the solar wind (i.e., the geomagnetic cycle) on climate, as well as the apparent close association between trends in global and northern hemispheric temperature and the length of the SC, although some investigators have described the inferred association between climate and, in particular, SC length as now being weak. More recently, Solheim et al. have reported on the relation between SC length and the average temperature in the same and immediately following SC for a number of meteorological stations in Norway and in the North Atlantic region. They noted that while they found no significant trend (correlation) between SC length and the average temperature when measured for the same cycle, in contrast, they found a significant negative trend when SC length was compared with the following cycle’s average temperature. From this observation, they suggested that average northern hemispheric temperature during the present ongoing SC (SC24) will be lower by about 0.9 °C than was seen in SC23 (spanning 1996–2007, based on yearly averages of sunspot number (SSN), and onset for SC24 occurring in 2008). The purpose of this Technical Publication (TP) is to examine the annual variations of the Armagh </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.B13E1805M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.B13E1805M">Shorter Harvest Cycles Counteract Increasing Annual Productivity in Industrial Plantation Forests: Trends from Three Decades of Remote Sensing in Southeastern Brazil</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> McMahon, D.; Jackson, R. B. 2017-12-01 Plantation forestry can produce woody biomass many times faster than native vegetation, particularly in the tropical regions where plantations have expanded rapidly in the past three decades. However, activists and practitioners have raised concerns over the sustainability of intensive plantations, suggesting that changes to soil properties may inhibit vegetation growth after multiple harvest cycles. We use a 32-year time series of remotely sensed vegetation indices derived from Landsat data, coupled with recent geospatial and wood volume data from plantation companies, to identify trends in management and vegetation productivity in thousands of individual eucalyptus plantation stands. We find that peak vegetation index values at canopy closure, which are correlated with annual wood volume increment, increase over successive harvest cycles, while the length of each cycle decreases. These opposing trends suggest that the number of harvests required to produce a given wood volume peaks around the second harvest cycle and then declines, likely due to refinement of management practices. Across the region, vegetation index data do not support the hypothesized decrease in productivity over multiple harvest cycles. Additional field data and ongoing soil analyses will complement the remote sensing approach to quantifying plantations' long-term effects on the land they occupy. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29216471','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29216471">Annual cycle of dimethylsulfoniopropionate (DMSP) and dimethylsulfoxide (DMSO) related to phytoplankton succession in the Southern North Sea.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Speeckaert, Gaëlle; Borges, Alberto V; Champenois, Willy; Royer, Colin; Gypens, Nathalie 2018-05-01 The influence of abiotic and biotic variables on the concentration of dimethyl sulfide (DMS), dimethylsulfoniopropionate (DMSP), and dimethylsulfoxide (DMSO), were investigated during an annual cycle in 2016 in the Belgian Coastal Zone (BCZ, North Sea). We reported strong seasonal variations in the concentration of these compounds linked to the phytoplankton succession with high DMS(P,O) producers (mainly Phaeocystis globosa) occurring in spring and low DMS(P,O) producers (various diatoms species) occurring in early spring and autumn. Spatial gradients of DMS and DMSP were related to those of phytoplankton biomass itself related to the inputs of nutrients from the Scheldt estuary. However, the use of a relationship with Chlorophyll-a (Chl-a) concentration is not sufficient to predict DMSP. Accounting for the phytoplankton composition, two different DMSP versus Chl-a correlations could be established, one for diatoms and another one for Phaeocystis colonies. We also reported high nearshore DMSO concentrations uncoupled to Chl-a and DMSP concentrations but linked to high suspended particulate matter (SPM) presumably coming from the Scheldt estuary as indicated by the positive relationship between annual average SPM and salinity. Copyright © 2017 Elsevier B.V. All rights reserved. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRC..122.9999M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRC..122.9999M">Physical and Biogeochemical Controls of the Phytoplankton Blooms in North Western Mediterranean Sea: A Multiplatform Approach Over a Complete Annual Cycle (2012-2013 DEWEX Experiment)</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Mayot, Nicolas; D'Ortenzio, Fabrizio; Taillandier, Vincent; Prieur, Louis; de Fommervault, Orens Pasqueron; Claustre, Hervé; Bosse, Anthony; Testor, Pierre; Conan, Pascal 2017-12-01 The North Western Mediterranean Sea exhibits recurrent and significant autumnal and spring phytoplankton blooms. The existence of these two blooms coincides with typical temperate dynamics. To determine the potential control of physical and biogeochemical factors on these phytoplankton blooms, data from a multiplatform approach (combining ships, Argo and BGC-Argo floats, and bio-optical gliders) were analyzed in association with satellite observations in 2012-2013. The satellite framework allowed a simultaneous analysis over the whole annual cycle of in situ observations of mixed layer depth, photosynthetical available radiation, particle backscattering, nutrients (nitrate and silicate), and chlorophyll-a concentrations. During the year 2012-2013, satellite ocean color observations, confirmed by in situ data, have revealed the existence of two areas (or bioregions) with comparable autumnal blooms but contrasting spring blooms. In both bioregions, the ratio of the euphotic zone (defined as the isolume 0.415 mol photons m-2 d-1, Z0.415) and the MLD identified the initiation of the autumnal bloom, as well as the maximal annual increase in [Chl-a] in spring. In fact, the autumnal phytoplankton bloom might be initiated by mixing of the summer shallowing deep chlorophyll maximum, while the spring restratification (when Z0.415/MLD ratio became >1) might induce surface phytoplankton production that largely overcomes the losses. Finally, winter deep convection events that took place in one of the bioregions induced higher net accumulation rate of phytoplankton in spring associated with a diatom-dominated phytoplankton community principally. We suggest that very deep winter MLD lead to an increase in surface silicates availability, which favored the development of diatoms. </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active">8</li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_9" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active">9</li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="161"> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23529770','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23529770">Annual plants change in size over a century of observations.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Leger, Elizabeth A 2013-07-01 Studies have documented changes in animal body sizes over the last century, but very little is known about changes in plant sizes, even though reduced plant productivity is potentially responsible for declines in size of other organisms. Here, I ask whether warming trends in the Great Basin have affected plant size by measuring specimens preserved on herbarium sheets collected between 1893 and 2011. I asked how maximum and minimum temperatures, precipitation, and the Pacific Decadal Oscillation (PDO) in the year of collection affected plant height, leaf size, and flower number, and asked whether changes in climate resulted in decreasing sizes for seven annual forbs. Species had contrasting responses to climate factors, and would not necessarily be expected to respond in parallel to climatic shifts. There were generally positive relationships between plant size and increased minimum and maximum temperatures, which would have been predicted to lead to small increases in plant sizes over the observation period. While one species increased in size and flower number over the observation period, five of the seven species decreased in plant height, four of these decreased in leaf size, and one species also decreased in flower production. One species showed no change. The mechanisms behind these size changes are unknown, and the limited data available on these species (germination timing, area of occupancy, relative abundance) did not explain why some species shrank while others grew or did not change in size over time. These results show that multiple annual forbs are decreasing in size, but that even within the same functional group, species may have contrasting responses to similar environmental stimuli. Changes in plant size could have cascading effects on other members of these communities, and differential responses to directional change may change the composition of plant communities over time. © 2013 Blackwell Publishing Ltd. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SGeo...35..491R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SGeo...35..491R">Review of Understanding of Earth's Hydrological Cycle: Observations, Theory and Modelling</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Rast, Michael; Johannessen, Johnny; Mauser, Wolfram 2014-05-01 Water is our most precious and arguably most undervalued natural resource. It is essential for life on our planet, for food production and economic development. Moreover, water plays a fundamental role in shaping weather and climate. However, with the growing global population, the planet's water resources are constantly under threat from overuse and pollution. In addition, the effects of a changing climate are thought to be leading to an increased frequency of extreme weather causing floods, landslides and drought. The need to understand and monitor our environment and its resources, including advancing our knowledge of the hydrological cycle, has never been more important and apparent. The best approach to do so on a global scale is from space. This paper provides an overview of the major components of the hydrological cycle, the status of their observations from space and related data products and models for hydrological variable retrievals. It also lists the current and planned satellite missions contributing to advancing our understanding of the hydrological cycle on a global scale. Further details of the hydrological cycle are substantiated in several of the other papers in this Special Issue. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMGC51B0758H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMGC51B0758H">How Ocean Color Influences the Interplay Between Annual and Interannual Tropical Pacific Variability</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Hammann, A. C.; Gnanadesikan, A. 2010-12-01 While the basic mechanisms responsible for ENSO have long been known, many details still evade our understanding. Since the behavior of the real climate system appears to be highly sensitive to such details, however, our ability to model, let alone predict it with any confidence has so far been rather restricted. Not only can small perturbations in many state variables lead to strongly amplified responses, but also do spatial and temporal scales of variability rarely occur in isolation from each other. Both points are born out in the study by Anderson et al. (2009), who removed surface chlorophyll in different regions of the tropical (but mostly off-equatorial) Pacific in a coupled ocean-atmosphere-land-ice model. Different removal patterns lead to large differences in the amplitudes of both ENSO and the equatorial annual cycle. Anderson et al.’s analysis focuses on ENSO and reveals that the transmission of off-equatorial perturbations to the equator happens mainly through a changed atmospheric response to SST anomalies. Here, we analyze the same data with respect to the annual cycle and how it interacts with ENSO. Guilyardi (2006) reports that observations and models alike show a zero-sum-type behavior of annual and ENSO-scale variability; increased spectral power in the annual band means decreased power in the ENSO band and vice versa. This is not the case for the different patterns of chlorophyll removal in our model, and hence it appears that this removal changes a fundamental part of its mean state. The dynamics of the annual cycle are likely influenced by oceanic meridional temperature advection, which provides another possible route for off-to-equatorial signal propagation. A common aspect of the tropical annual cycle in most coupled climate models is the presence of a double ITCZ instead of a single north-shifted one. Even though this appears to be unrelated to (albeit influenced by) the changes in ocean color, our model exhibits a much improved </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20120003987&hterms=budget&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dbudget','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20120003987&hterms=budget&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dbudget">Estimating Evapotranspiration Using an Observation Based Terrestrial Water Budget</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Rodell, Matthew; McWilliams, Eric B.; Famiglietti, James S.; Beaudoing, Hiroko K.; Nigro, Joseph 2011-01-01 Evapotranspiration (ET) is difficult to measure at the scales of climate models and climate variability. While satellite retrieval algorithms do exist, their accuracy is limited by the sparseness of in situ observations available for calibration and validation, which themselves may be unrepresentative of 500m and larger scale satellite footprints and grid pixels. Here, we use a combination of satellite and ground-based observations to close the water budgets of seven continental scale river basins (Mackenzie, Fraser, Nelson, Mississippi, Tocantins, Danube, and Ubangi), estimating mean ET as a residual. For any river basin, ET must equal total precipitation minus net runoff minus the change in total terrestrial water storage (TWS), in order for mass to be conserved. We make use of precipitation from two global observation-based products, archived runoff data, and TWS changes from the Gravity Recovery and Climate Experiment satellite mission. We demonstrate that while uncertainty in the water budget-based estimates of monthly ET is often too large for those estimates to be useful, the uncertainty in the mean annual cycle is small enough that it is practical for evaluating other ET products. Here, we evaluate five land surface model simulations, two operational atmospheric analyses, and a recent global reanalysis product based on our results. An important outcome is that the water budget-based ET time series in two tropical river basins, one in Brazil and the other in central Africa, exhibit a weak annual cycle, which may help to resolve debate about the strength of the annual cycle of ET in such regions and how ET is constrained throughout the year. The methods described will be useful for water and energy budget studies, weather and climate model assessments, and satellite-based ET retrieval optimization. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JGRD..123.1460C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JGRD..123.1460C">On the Ability of Space-Based Passive and Active Remote Sensing Observations of CO2 to Detect Flux Perturbations to the Carbon Cycle</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Crowell, Sean M. R.; Randolph Kawa, S.; Browell, Edward V.; Hammerling, Dorit M.; Moore, Berrien; Schaefer, Kevin; Doney, Scott C. 2018-01-01 Space-borne observations of CO2 are vital to gaining understanding of the carbon cycle in regions of the world that are difficult to measure directly, such as the tropical terrestrial biosphere, the high northern and southern latitudes, and in developing nations such as China. Measurements from passive instruments such as GOSAT and OCO-2, however, are constrained by solar zenith angle limitations as well as sensitivity to the presence of clouds and aerosols. Active measurements such as those in development for the Active Sensing of CO2 Emissions over Nights, Days and Seasons (ASCENDS) mission show strong potential for making measurements in the high-latitude winter and in cloudy regions. In this work we examine the enhanced flux constraint provided by the improved coverage from an active measurement such as ASCENDS. The simulation studies presented here show that with sufficient precision, ASCENDS will detect permafrost thaw and fossil fuel emissions shifts at annual and seasonal time scales, even in the presence of transport errors, representativeness errors, and biogenic flux errors. While OCO-2 can detect some of these perturbations at the annual scale, the seasonal sampling provided by ASCENDS provides the stronger constraint. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4625958','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4625958">Annual Reproductive Cycle and Unusual Embryogenesis of a Temperate Coral in the Mediterranean Sea</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> Marchini, Chiara; Airi, Valentina; Fontana, Roberto; Tortorelli, Giada; Rocchi, Marta; Falini, Giuseppe; Levy, Oren; Dubinsky, Zvy; Goffredo, Stefano 2015-01-01 The variety of reproductive processes and modes among coral species reflects their extraordinary regeneration ability. Scleractinians are an established example of clonal animals that can exhibit a mixed strategy of sexual and asexual reproduction to maintain their populations. This study provides the first description of the annual reproductive cycle and embryogenesis of the temperate species Caryophyllia inornata. Cytometric analyses were used to define the annual development of germ cells and embryogenesis. The species was gonochoric with three times more male polyps than female. Polyps were sexually mature from 6 to 8 mm length. Not only females, but also sexually inactive individuals (without germ cells) and males were found to brood their embryos. Spermaries required 12 months to reach maturity, while oogenesis seemed to occur more rapidly (5–6 months). Female polyps were found only during spring and summer. Furthermore, the rate of gamete development in both females and males increased significantly from March to May and fertilization was estimated to occur from April to July, when mature germ cells disappeared. Gametogenesis showed a strong seasonal influence, while embryos were found throughout the year in males and in sexually inactive individuals without a defined trend. This unusual embryogenesis suggests the possibility of agamic reproduction, which combined with sexual reproduction results in high fertility. This mechanism is uncommon and only four other scleractinians (Pocillopora damicornis, Tubastraea diaphana, T. coccinea and Oulastrea crispata) have been shown to generate their broods asexually. The precise nature of this process is still unknown. PMID:26513159 </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010BGeo....7..959U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010BGeo....7..959U">Simulating carbon and water cycles of larch forests in East Asia by the BIOME-BGC model with AsiaFlux data</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Ueyama, M.; Ichii, K.; Hirata, R.; Takagi, K.; Asanuma, J.; Machimura, T.; Nakai, Y.; Ohta, T.; Saigusa, N.; Takahashi, Y.; Hirano, T. 2010-03-01 Larch forests are widely distributed across many cool-temperate and boreal regions, and they are expected to play an important role in global carbon and water cycles. Model parameterizations for larch forests still contain large uncertainties owing to a lack of validation. In this study, a process-based terrestrial biosphere model, BIOME-BGC, was tested for larch forests at six AsiaFlux sites and used to identify important environmental factors that affect the carbon and water cycles at both temporal and spatial scales. The model simulation performed with the default deciduous conifer parameters produced results that had large differences from the observed net ecosystem exchange (NEE), gross primary productivity (GPP), ecosystem respiration (RE), and evapotranspiration (ET). Therefore, we adjusted several model parameters in order to reproduce the observed rates of carbon and water cycle processes. This model calibration, performed using the AsiaFlux data, substantially improved the model performance. The simulated annual GPP, RE, NEE, and ET from the calibrated model were highly consistent with observed values. The observed and simulated GPP and RE across the six sites were positively correlated with the annual mean air temperature and annual total precipitation. On the other hand, the simulated carbon budget was partly explained by the stand disturbance history in addition to the climate. The sensitivity study indicated that spring warming enhanced the carbon sink, whereas summer warming decreased it across the larch forests. The summer radiation was the most important factor that controlled the carbon fluxes in the temperate site, but the VPD and water conditions were the limiting factors in the boreal sites. One model parameter, the allocation ratio of carbon between belowground and aboveground, was site-specific, and it was negatively correlated with the annual climate of annual mean air temperature and total precipitation. Although this study substantially </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009BGD.....6.8311U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009BGD.....6.8311U">Simulating carbon and water cycles of larch forests in East Asia by the BIOME-BGC model with AsiaFlux data</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Ueyama, M.; Ichii, K.; Hirata, R.; Takagi, K.; Asanuma, J.; Machimura, T.; Nakai, Y.; Ohta, T.; Saigusa, N.; Takahashi, Y.; Hirano, T. 2009-08-01 Larch forests are widely distributed across many cool-temperate and boreal regions, and they are expected to play an important role in global carbon and water cycles. Model parameterizations for larch forests still contain large uncertainties owing to a lack of validation. In this study, a process-based terrestrial biosphere model, BIOME-BGC, was tested for larch forests at six AsiaFlux sites and used to identify important environmental factors that affect the carbon and water cycles at both temporal and spatial scales. The model simulation performed with the default deciduous conifer parameters produced results that had large differences from the observed net ecosystem exchange (NEE), gross primary productivity (GPP), ecosystem respiration (RE), and evapotranspiration (ET). Therefore, we adjusted several model parameters in order to reproduce the observed rates of carbon and water cycle processes. This model calibration, performed using the AsiaFlux data, significantly improved the model performance. The simulated annual GPP, RE, NEE, and ET from the calibrated model were highly consistent with observed values. The observed and simulated GPP and RE across the six sites are positively correlated with the annual mean air temperature and annual total precipitation. On the other hand, the simulated carbon budget is partly explained by the stand disturbance history in addition to the climate. The sensitivity study indicates that spring warming enhances the carbon sink, whereas summer warming decreases it across the larch forests. The summer radiation is the most important factor that controls the carbon fluxes in the temperate site, but the VPD and water conditions are the limiting factors in the boreal sites. One model parameter, the allocation ratio of carbon between aboveground and belowground, is site-specific, and it is negatively correlated with the annual climate of annual mean air temperature and total precipitation. Although this study significantly improves </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26991665','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26991665">Altitudinal and climatic associations of seed dormancy and flowering traits evidence adaptation of annual life cycle timing in Arabidopsis thaliana.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Vidigal, Deborah S; Marques, Alexandre C S S; Willems, Leo A J; Buijs, Gonda; Méndez-Vigo, Belén; Hilhorst, Henk W M; Bentsink, Leónie; Picó, F Xavier; Alonso-Blanco, Carlos 2016-08-01 The temporal control or timing of the life cycle of annual plants is presumed to provide adaptive strategies to escape harsh environments for survival and reproduction. This is mainly determined by the timing of germination, which is controlled by the level of seed dormancy, and of flowering initiation. However, the environmental factors driving the evolution of plant life cycles remain largely unknown. To address this question we have analysed nine quantitative life history traits, in a native regional collection of 300 wild accessions of Arabidopsis thaliana. Seed dormancy and flowering time were negatively correlated, indicating that these traits have coevolved. In addition, environmental-phenotypic analyses detected strong altitudinal and climatic clines for most life history traits. Overall, accessions showing life cycles with early flowering, small seeds, high seed dormancy and slow germination rate were associated with locations exposed to high temperature, low summer precipitation and high radiation. Furthermore, we analysed the expression level of the positive regulator of seed dormancy DELAY OF GERMINATION 1 (DOG1), finding similar but weaker altitudinal and climatic patterns than seed dormancy. Therefore, DOG1 regulatory mutations are likely to provide a quantitative molecular mechanism for the adaptation of A. thaliana life cycle to altitude and climate. © 2016 John Wiley & Sons Ltd. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120009100','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120009100">The Annual Glaciohydrology Cycle in the Ablation Zone of the Greenland Ice Sheet: Part 1. Hydrology Model</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Colgan, William; Rajaram, Harihar; Anderson, Robert; Steffen. Konrad; Phillips, Thomas; Zwally, H. Jay; Abdalati, Waleed 2012-01-01 We apply a novel one-dimensional glacier hydrology model that calculates hydraulic head to the tidewater-terminating Sermeq Avannarleq flowline of the Greenland ice sheet. Within a plausible parameter space, the model achieves a quasi-steady-state annual cycle in which hydraulic head oscillates close to flotation throughout the ablation zone. Flotation is briefly achieved during the summer melt season along a approx.17 km stretch of the approx.50 km of flowline within the ablation zone. Beneath the majority of the flowline, subglacial conduit storage closes (i.e. obtains minimum radius) during the winter and opens (i.e. obtains maximum radius) during the summer. Along certain stretches of the flowline, the model predicts that subglacial conduit storage remains open throughout the year. A calculated mean glacier water residence time of approx.2.2 years implies that significant amounts of water are stored in the glacier throughout the year. We interpret this residence time as being indicative of the timescale over which the glacier hydrologic system is capable of adjusting to external surface meltwater forcings. Based on in situ ice velocity observations, we suggest that the summer speed-up event generally corresponds to conditions of increasing hydraulic head during inefficient subglacial drainage. Conversely, the slowdown during fall generally corresponds to conditions of decreasing hydraulic head during efficient subglacial drainage. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title50-vol10/pdf/CFR-2014-title50-vol10-sec222-402.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title50-vol10/pdf/CFR-2014-title50-vol10-sec222-402.pdf">50 CFR 222.402 - Annual determination of fisheries to be observed; notice and comment.</a> <a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a> 2014-10-01 ... ENDANGERED AND THREATENED MARINE SPECIES Observer Requirement § 222.402 Annual determination of fisheries to... Protection Act List of Fisheries in any given year, in accordance with 16 U.S.C. 1387, will serve as the... Protection Act List of Fisheries process as specified at 50 CFR 229.8. (e) Inclusion of a fishery in a... </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title50-vol10/pdf/CFR-2013-title50-vol10-sec222-402.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title50-vol10/pdf/CFR-2013-title50-vol10-sec222-402.pdf">50 CFR 222.402 - Annual determination of fisheries to be observed; notice and comment.</a> <a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a> 2013-10-01 ... ENDANGERED AND THREATENED MARINE SPECIES Observer Requirement § 222.402 Annual determination of fisheries to... Protection Act List of Fisheries in any given year, in accordance with 16 U.S.C. 1387, will serve as the... Protection Act List of Fisheries process as specified at 50 CFR 229.8. (e) Inclusion of a fishery in a... </li> <li> <a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=326737','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=326737">Pseudomonas fluorescens strains selectively suppress annual bluegrass (Poa annua L.)</a> <a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a> Annual bluegrass (Poa annua L.) is a cool-season annual grass that is a major weed species in turf, turfgrass-seed production, sod production, and golf courses of the western United States. There are few selective herbicides available for the management of annual bluegrass. While the life cycles o... </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017Ge%26Ae..57..798A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017Ge%26Ae..57..798A">Results of Spectral Corona Observations in Solar Activity Cycles 17-24</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Aliev, A. Kh.; Guseva, S. A.; Tlatov, A. G. 2017-12-01 The results of the work of the global observation network are considered, and a comparative analysis of the data of various coronal observatories is performed. The coronal activity index has been reconstructed for the period 1939-2016 based on the data of various observatories in Kislovodsk system. For this purpose, the corona daily intensity maps from the Sacramento Peak and Lomnický Štít observatories according to the Solar-Geophysical Data journal have been digitized; they supplement the data of other observatories. The homogeneity and continuity of the corona observations at the Kislovodsk station, including activity cycle 24, is confirmed. Unfortunately, the only observatory at present that continues observation of the spectral corona in Fe XIV 5303 Å and Fe XIV 6374 Å lines is the Kislovodsk astronomical station Mountain Astronomical Station (MAS) of the Central Astronomical Observatory, Russian Academy of Sciences (Pulkovo). The data on the combined corona in 5303 Å line are analyzed. It is shown that there is a high correlation of the intensity index of green corona with solar radiation measurements in the vacuum UV region. Data on the beginning of the new 25th activity cycle in the corona at high latitudes are presented. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1511209H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1511209H">Seasonal cycle of oceanic mixed layer and upper-ocean heat fluxes in the Mediterranean Sea from in-situ observations.</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Houpert, Loïc; Testor, Pierre; Durrieu de Madron, Xavier; Estournel, Claude; D'Ortenzio, Fabrizio 2013-04-01 Heat fluxes across the ocean-atmosphere interface play a crucial role in the upper turbulent mixing. The depth reached by this turbulent mixing is indicated by an homogenization of seawater properties in the surface layer, and is defined as the Mixed Layer Depth (MLD). The thickness of the mixed layer determines also the heat content of the layer that directly interacts with the atmosphere. The seasonal variability of these air-sea fluxes is crucial in the calculation of heat budget. An improvement in the estimate of these fluxes is needed for a better understanding of the Mediterranean ocean circulation and climate, in particular in Regional Climate Models. There are few estimations of surface heat fluxes based on oceanic observations in the Mediterranean, and none of them are based on mixed layer observations. So, we proposed here new estimations of these upper-ocean heat fluxes based on mixed layer. We present high resolution Mediterranean climatology (0.5°) of the mean MLD based on a comprehensive collection of temperature profiles of last 43 years (1969-2012). The database includes more than 150,000 profiles, merging CTD, XBT, ARGO Profiling floats, and gliders observations. This dataset is first used to describe the seasonal cycle of the mixed layer depth on the whole Mediterranean on a monthly climatological basis. Our analysis discriminates several regions with coherent behaviors, in particular the deep water formation sites, characterized by significant differences in the winter mixing intensity. Heat storage rates (HSR) were calculated as the time rate of change of the heat content integrated from the surface down to a specific depth that is defined as the MLD plus an integration constant. Monthly climatology of net heat flux (NHF) from ERA-Interim reanalysis was balanced by the 1°x1° resolution heat storage rate climatology. Local heat budget balance and seasonal variability in the horizontal heat flux are then discussed by taking into account </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910062731&hterms=methane+composition&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dmethane%2Bcomposition','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910062731&hterms=methane+composition&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dmethane%2Bcomposition">Three-Dimensional Model Synthesis of the Global Methane Cycle</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Fung, I.; Prather, M.; John, J.; Lerner, J.; Matthews, E. 1991-01-01 A synthesis of the global methane cycle is presented to attempt to generate an accurate global methane budget. Methane-flux measurements, energy data, and agricultural statistics are merged with databases of land-surface characteristics and anthropogenic activities. The sources and sinks of methane are estimated based on atmospheric methane composition and variations, and a global 3D transport model simulates the corresponding atmospheric responses. The geographic and seasonal variations of candidate budgets are compared with observational data, and the available observations are used to constrain the plausible methane budgets. The preferred budget includes annual destruction rates and annual emissions for various sources. The lack of direct flux measurements in the regions of many of these fluxes makes the unique determination of each term impossible. OH oxidation is found to be the largest single term, although more measurements of this and other terms are recommended. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/6434031-modeled-latitudinal-distribution-ozone-quasi-biennial-oscillation-using-observed-equatorial-winds','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/6434031-modeled-latitudinal-distribution-ozone-quasi-biennial-oscillation-using-observed-equatorial-winds">The modeled latitudinal distribution of the ozone quasi-biennial oscillation using observed equatorial winds</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Gray, L.J.; Ruth, S. 1993-04-15 A simulation of precise years of the quasi-biennial oscillation (QBO) is achieved in a two-dimensional model by relaxing the modeled equatorial winds in the lower stratosphere toward radiosonde observations. The model has been run for the period 1971-90. A QBO signal in column ozone is produced in the model that agrees reasonably well with observational data from the BUV, TOMS, and SAGE II satellite datasets. The model results confirm previous indications of the importance of the interaction of the QBO with the annual cycle in the determination of the subtropical ozone anomaly. The low-frequency modulation of the subtropical ozone anomalymore » is now particularly clear. The low-frequency modulation of the subtropical ozone anomaly in the model arises as a result of the interaction of the QBO with the annual cycle in the vertical advection by the Hadley circulation. The possibility of a further, similar modulation arising from the interaction of the equatorial wind QBO and the annual cycle in midlatitude eddy activity is discussed, with particular emphasis on the implications for the eddy transfer of ozone to high latitudes and on the ability to predict the severity of the Antarctic ozone hole. A link is proposed between the QBO signal in the severity of the Antarctic ozone hole and the amount of ozone observed in the subtropical/midlatitude springtime maximum in the Southern Hemisphere. On the basis of this relationship, the reliability of the model as a predictor of the severity of the ozone hole is explored. A conclusion of the study is that a reliable predictor of the severity of the ozone hole must take into account the timing of the descent of the equatorial wind QBO at the equator with respect to the annual cycle and that the use, as in previous studies, of a single parameter, such as the sign of the 50-mb equatorial wind, will not be entirely reliable because it cannot do this. 31 refs., 11 figs.« less </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20180000764','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20180000764">A Study of the Carbon Cycle Using NASA Observations and the GEOS Model</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Pawson, Steven; Gelaro, Ron; Ott, Lesley; Putman, Bill; Chatterjee, Abhishek; Koster, Randy; Lee, Eunjee; Oda, Tom; Weir, Brad; Zeng, Fanwei 2018-01-01 The Goddard Earth Observing System (GEOS) model has been developed in the Global Modeling and Assimilation Office (GMAO) at NASA's Goddard Space Flight Center. From its roots in chemical transport and as a General Circulation Model, the GEOS model has been extended to an Earth System Model based on a modular construction using the Earth System Modeling Framework (ESMF), combining elements developed in house in the GMAO with others that are imported through collaborative research. It is used extensively for research and for product generation, both as a free-running model and as the core of the GMAO's data assimilation system. In recent years, the GMAO's modeling and assimilation efforts have been strongly supported by Piers Sellers, building on both his earlier legacy as an observationally oriented model developer and his post-astronaut career as a dynamic leader into new territory. Piers' long-standing interest in the carbon cycle and the combination of models with observations motivates this presentation, which will focus on the representation of the carbon cycle in the GEOS Earth System Model. Examples will include: (i) the progression from specified land-atmosphere surface fluxes to computations with an interactive model component (Catchment-CN), along with constraints on vegetation distributions using satellite observations; (ii) the use of high-resolution satellite observations to constrain human-generated inputs to the atmosphere; (iii) studies of the consistency of the observed atmospheric carbon dioxide concentrations with those in the model simulations. The presentation will focus on year-to-year variations in elements of the carbon cycle, specifically on how the observations can inform the representation of mechanisms in the model and lead to integrity in global carbon dioxide simulations. Further, applications of the GEOS model to the planning of new carbon-climate observations will be addressed, as an example of the work that was strongly supported by </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004cosp...35.4460C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004cosp...35.4460C">Martian Dust Cycle</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Cantor, B. A.; James, P. B. The Mars Observer Camera (MOC), aboard Mars Global Surveyor (MGS), has completed approximately 3 consecutive Martian years of global monitoring, since entering its mapping orbit on March 9, 1999. MOC observations have shown the important role that dust devils and dust storms play in the Martian dust cycle on time scales ranging from semi-diurnally to interannually. These dust events have been observed across much of the planet from the depths of Hellas basin to the summit of Arsia Mons and range in size from10s of meters across (dust devils) to planet encircling (global dust veils). Though dust devils occur throughout most of the Martian year, each hemisphere has a "dust devil season" that generally follows the subsolar latitude and appears to be repeatable from year-to-year. An exception is NW Amazonis, which has frequent, large dust devils throughout northern spring and summer. MOC observations show no evidence that dust devils cause or lead to dust storms, however, observations do suggest that dust storms can initiate dust devil activity. Dust devils also might play a role in maintaining the low background dust opacity of the Martian atmosphere. Dust storms occur almost daily with few exceptions, with 1000s occurring each year in the present Martian environment, dispelling the notion of a "Classical Dust Storm Season". However, there does appear to be an annual dust storm cycle, with storms developing in specific locations during certain seasons and that some individual storm events are repeatable from year-to-year. The majority of storms develop near the receding seasonal polar cap edge or along the corresponding polar hood boundaries in their respective hemispheres, but they also occur in the northern plains, the windward side of the large shield volcanoes, and in low laying regions such as Hellas, Argyre, and Chryse. The rarest of dust events are the "Great Storms" or "Global Events", of which only 6 (4 "planet encircling" and 2 "global") have been observed </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70027897','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70027897">Disparate effects of constant and annually-cycling daylength and water temperature on reproductive maturation of striped bass (Morone saxatilis)</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Clark, R.W.; Henderson-Arzapalo, A.; Sullivan, C.V. 2005-01-01 Adult striped bass (Morone saxatilis) were exposed to various combinations of constant or anually-cycling daylength and water temperature. Constant conditions (15 h days, 18??C) were those normally experienced at spawning and cycling conditions simulated natural changes at Chesapeake Bay latitude. Females exposed to constant long (15 h) days and cycling water temperature (TEMPERATURE group) had blood plasma levels of sex steroids (testosterone [T] and estradiol-17?? [E2]) and vitellogenin (Vg), and profiles of oocyte growth, that were nearly identical to those of females held under a natural photothermal cycle (CONTROL group). Several fish from these two groups were induced to spawn fertile eggs. Females constantly exposed to warm water (18??C), with or without a natural photoperiod cycle (PHOTOPERIOD and STATIC groups, respectively), had diminished circulating levels of gonadal steroid hormones and Vg, impaired deposition of yolk granules in their ooplasm, and decreased oocyte growth, and they underwent premature ovarian atresia. Males exposed to cycling water temperature (CONTROL and TEMPERATURE groups) spermiated synchronously during the natural breeding season, at which time they also had had high plasma androgen (T and 11-ketotestosterone [11-KT]) levels. The timing of spermiation was highly asynchronous among males in groups of fish held constantly at 18??C (STATIC and PHOTOPERIOD groups) and this asynchrony was associated with diminished plasma androgen levels. Termination of spermiation by males exposed to cycling water temperature coincided with a sharp decline in levels of plasma androgens about a month after water temperature rose above 18??C. In contrast, most males held constantly at 18??C sustained intermediate levels of plasma androgens and spermiated until the end of the study in late July. The annual cycle of water temperature clearly plays a prominent role in the initiation, maintenance, and termination of the striped bass reproductive cycle. In </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active">9</li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_10" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active">10</li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="181"> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29072032','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29072032">Training-induced annual changes in red blood cell profile in highly-trained endurance and speed-power athletes.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Ciekot-Sołtysiak, Monika; Kusy, Krzysztof; Podgórski, Tomasz; Zieliński, Jacek 2017-10-24 An extensive body of literature exists on the effects of training on haematological parameters, but the previous studies have not reported how hematological parameters respond to changes in training loads within consecutive phases of the training cycle in highly-trained athletes in extremely different sport disciplines. The aim of this study was to identify changes in red blood cell (RBC) profile in response to training loads in consecutive phases of the annual training cycle in highly-trained sprinters (8 men, aged 24 ± 3 years) and triathletes (6 men, aged 24 ± 4 years) who competed at the national and international level. Maximal oxygen uptake (VO2max), RBC, haemoglobin (Hb), haematocrit (Ht), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC) and RBC distribution width (RDW) were determined in four characteristic training phases (transition, general subphase of the preparation phase, specific subphase of the preparation phase and competition phase). Our main findings are that (1) Hb, MCH and MCHC in triathletes and MCV in both triathletes and sprinters changed significantly over the annual training cycle, (2) triathletes had significantly higher values than sprinters only in case of MCH and MCHC after the transition and general preparation phases but not after the competition phase when MCH and MCHC were higher in sprinters and (3) in triathletes, Hb, MCH and MCHC substantially decreased after the competition phase, which was not observed in sprinters. The athletes maintained normal ranges of all haematological parameters in four characteristic training phases. Although highly-trained sprinters and triathletes do not significantly differ in their levels of most haematological parameters, these groups are characterized by different patterns of changes during the annual training cycle. Our results suggest that when interpreting the values of haematological parameters in speed-power and endurance </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28972900','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28972900">A statistical model for predicting the inter-annual variability of birch pollen abundance in Northern and North-Eastern Europe.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Ritenberga, Olga; Sofiev, Mikhail; Siljamo, Pilvi; Saarto, Annika; Dahl, Aslog; Ekebom, Agneta; Sauliene, Ingrida; Shalaboda, Valentina; Severova, Elena; Hoebeke, Lucie; Ramfjord, Hallvard 2018-02-15 The paper suggests a methodology for predicting next-year seasonal pollen index (SPI, a sum of daily-mean pollen concentrations) over large regions and demonstrates its performance for birch in Northern and North-Eastern Europe. A statistical model is constructed using meteorological, geophysical and biological characteristics of the previous year). A cluster analysis of multi-annual data of European Aeroallergen Network (EAN) revealed several large regions in Europe, where the observed SPI exhibits similar patterns of the multi-annual variability. We built the model for the northern cluster of stations, which covers Finland, Sweden, Baltic States, part of Belarus, and, probably, Russia and Norway, where the lack of data did not allow for conclusive analysis. The constructed model was capable of predicting the SPI with correlation coefficient reaching up to 0.9 for some stations, odds ratio is infinitely high for 50% of sites inside the region and the fraction of prediction falling within factor of 2 from observations, stays within 40-70%. In particular, model successfully reproduced both the bi-annual cycle of the SPI and years when this cycle breaks down. Copyright © 2017 Elsevier B.V. All rights reserved. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMGC51F..08Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMGC51F..08Y">Changing water cycle over Korea</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Yoon, J. 2017-12-01 In 2015, Korea experienced relatively strong drought, and annual mean precipitation was the third lowest since observation started at 1969 causing adverse impact on the several sectors including farming industry. Most precipitation in Korea occurs during summer season. In case of 2015 Korean drought, summer rainfall was much below than normal. On the other hand, another severe drought occurred in 2017 spring, which was followed by a couple of heavy rainfall cases that caused human casualties and damage in various sectors. Here we want to analyze this fast shifting of water cycle over Korea with a focus on its causing mechanisms and large scale atmospheric circulation features. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ThApC.123..733S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ThApC.123..733S">Analysis of monthly, winter, and annual temperatures in Zagreb, Croatia, from 1864 to 2010: the 7.7-year cycle and the North Atlantic Oscillation</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Sen, Asok K.; Ogrin, Darko 2016-02-01 Long instrumental records of meteorological variables such as temperature and precipitation are very useful for studying regional climate in the past, present, and future. They can also be useful for understanding the influence of large-scale atmospheric circulation processes on the regional climate. This paper investigates the monthly, winter, and annual temperature time series obtained from the instrumental records in Zagreb, Croatia, for the period 1864-2010. Using wavelet analysis, the dominant modes of variability in these temperature series are identified, and the time intervals over which these modes may persist are delineated. The results reveal that all three temperature records exhibit low-frequency variability with a dominant periodicity at around 7.7 years. The 7.7-year cycle has also been observed in the temperature data recorded at several other stations in Europe, especially in Northern and Western Europe, and may be linked to the North Atlantic Oscillation (NAO) and/or solar/geomagnetic activity. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28419436','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28419436">Ammonia oxidizer populations vary with nitrogen cycling across a tropical montane mean annual temperature gradient.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Pierre, S; Hewson, I; Sparks, J P; Litton, C M; Giardina, C; Groffman, P M; Fahey, T J 2017-07-01 Functional gene approaches have been used to better understand the roles of microbes in driving forest soil nitrogen (N) cycling rates and bioavailability. Ammonia oxidation is a rate limiting step in nitrification, and is a key area for understanding environmental constraints on N availability in forests. We studied how increasing temperature affects the role of ammonia oxidizing archaea (AOA) and bacteria (AOB) in soil N cycling and availability by using a highly constrained natural mean annual temperature (MAT) elevation gradient in a tropical montane wet forest. We found that net nitrate (NO 3 - ) bioavailability is positively related to MAT (r 2 = 0.79, P = 0.0033), and AOA DNA abundance is positively related to both NO 3 - availability (r 2 = 0.34, P = 0.0071) and MAT (r 2 = 0.34, P < 0.001). In contrast, AOB DNA was only detected in some soils across the gradient. We identified three distinct phylotypes within the AOA which differed from one another in abundance and relative gene expression. In addition, one AOA phylotype increased in abundance with MAT, while others did not. We conclude that MAT is the primary driver of ecosystem N availability across this gradient, and AOA population size and structure appear to mediate the relationship between the nitrification and N bioavailability. These findings hold important implications for nutrient limitation in forests and feedbacks to primary production under changing climate. © 2017 by the Ecological Society of America. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150008964','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150008964">Connecting Satellite Observations with Water Cycle Variables Through Land Data Assimilation: Examples Using the NASA GEOS-5 LDAS</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Reichle, Rolf H.; De Lannoy, Gabrielle J. M.; Forman, Barton A.; Draper, Clara S.; Liu, Qing 2013-01-01 A land data assimilation system (LDAS) can merge satellite observations (or retrievals) of land surface hydrological conditions, including soil moisture, snow, and terrestrial water storage (TWS), into a numerical model of land surface processes. In theory, the output from such a system is superior to estimates based on the observations or the model alone, thereby enhancing our ability to understand, monitor, and predict key elements of the terrestrial water cycle. In practice, however, satellite observations do not correspond directly to the water cycle variables of interest. The present paper addresses various aspects of this seeming mismatch using examples drawn from recent research with the ensemble-based NASA GEOS-5 LDAS. These aspects include (1) the assimilation of coarse-scale observations into higher-resolution land surface models, (2) the partitioning of satellite observations (such as TWS retrievals) into their constituent water cycle components, (3) the forward modeling of microwave brightness temperatures over land for radiance-based soil moisture and snow assimilation, and (4) the selection of the most relevant types of observations for the analysis of a specific water cycle variable that is not observed (such as root zone soil moisture). The solution to these challenges involves the careful construction of an observation operator that maps from the land surface model variables of interest to the space of the assimilated observations. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19890058230&hterms=SME&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DSME','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19890058230&hterms=SME&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DSME">A seven-month solar cycle observed with the Langmuir probe on Pioneer Venus Orbiter</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Hoegy, W. R.; Wolff, C. L. 1989-01-01 Data collected by the Langmuir probe aboard the Pioneer Venus orbiter (PVO) over the years 1979 though 1987 were normalized to remove the long-period 11-year solar maximum to minimum trend and were analyzed for periodicity. Results yield evidence for the existence of an approximately 7-month solar cycle, which was also observed from SME Lyman alpha and 2800-MHz radio flux measurements carried out from an earth-based platform. This coincidence suggests that the cycle is an intrinsic periodicity in the solar output. The cycle has a frequency independent of the orbital frequency of the PVO and is distinct from a 'rotating beacon' cycle whose period depends on the orbital motion of the PVO about the sun. The second most dominant cycle discovered was a 5-month period. Results of an oscillation model of solar periodicity indicate that the 7-month and 5-month cycles are caused by long-lived flux enhancements from nonlinear interactions of global oscillation modes in the sun's convective envelope (r modes) and radiative interior (g modes). </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19980002735','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19980002735">Prelude to Cycle 23: The Case for a Fast-Rising, Large Amplitude Cycle</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Wilson, Robert M.; Hathaway, David H.; Reichmann, Edwin J. 1996-01-01 For the common data-available interval of cycles 12 to 22, we show that annual averages of sunspot number for minimum years (R(min)) and maximum years (R(max)) and of the minimum value of the aa geomagnetic index in the vicinity of sunspot minimum (aa(min)) are consistent with the notion that each has embedded within its respective record a long-term, linear, secular increase. Extrapolating each of these fits to cycle 23, we infer that it will have R(min) = 12.7 +/- 5.7, R(max) = 176.7 +/- 61.8, and aa(min) = 21.0 +/- 5.0 (at the 95-percent level of confidence), suggesting that cycle 23 will have R(min) greater than 7.0, R(max) greater than 114.9, and aa(min) greater than 16.0 (at the 97.5-percent level of confidence). Such values imply that cycle 23 will be larger than average in size and, consequently (by the Waidmeier effect), will be a fast riser. We also infer from the R(max) and aa(min) records the existence of an even- odd cycle effect, one in which the odd-following cycle is numerically larger in value than the even-leading cycle. For cycle 23, the even-odd cycle effect suggests that R(max) greater than 157.6 and aa(min) greater than 19.0, values that were recorded for cycle 22, the even-leading cycle of the current even-odd cycle pair (cycles 22 and 23). For 1995, the annual average of the aa index measured about 22, while for sunspot number, it was about 18. Because aa(min) usually lags R(min) by 1 year (true for 8 of 11 cycles) and 1996 seems destined to be the year of R(min) for cycle 23, it may be that aa(min) will occur in 1997, although it could occur in 1996 in conjunction with R(min) (true for 3 of 11 cycles). Because of this ambiguity in determining aa(min), no formal prediction based on the correlation of R(max) against aa(min), having r = 0.90, or of R(max) against the combined effects of R(min) and aa(min)-the bivariate technique-having r = 0.99, is possible until 1997, at the earliest. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19990040754&hterms=numeric&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dnumeric','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19990040754&hterms=numeric&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dnumeric">Comment on "The Predicted Size of Cycle 23 Based on the Inferred three-cycle Quasiperiodicity of the Planetary Index Ap"</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Wilson, Robert M.; Hathaway, David H. 1999-01-01 Recently, Ahluwalia reviewed the solar and geomagnetic data for the last 6 decades and remarked that these data "indicate the existence of a three-solar-activity-cycle quasiperiodicity in them." Furthermore, on the basis of this inferred quasiperiodicity, he asserted that cycle 23 represents the initial cycle in a new three-cycle string, implying that it "will be more modest (a la cycle 17) with an annual mean sunspot number count of 119.3 +/- 30 at the maximum", a prediction that is considerably below the consensus prediction of 160 +/- 30 by Joselin et al. and of similar predictions by others based on a variety of predictive techniques. Several major sticking points of Ahluwalia's presentation, however, must be readdressed, and these issues form the basis of this comment. First, Ahluwalia appears to have based his analysis on a data set of Ap index values that is erroneous. For example, he depicts for the interval of 1932-1997 the variation of the Ap index in terms of annual averages, contrasting them against annual averages of sunspot number (SSN), and he lists for cycles 17-23 the minimum and maximum value of each, as well as the years in which they occur and a quantity which he calls "Amplitude" (defined as the numeric difference between the maximum and minimum values). In particular, he identifies the minimum Ap index (i.e., the minimum value of the Ap index in the vicinity of sunspot cycle minimum, which usually occurs in the year following sunspot minimum and which will be called hereafter, simply, Ap min) and the year in which it occur for cycles 17 - 23 respectively. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/21450947-extreme-ultraviolet-explorer-observations-hercules-over-day-cycle','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/21450947-extreme-ultraviolet-explorer-observations-hercules-over-day-cycle">EXTREME ULTRAVIOLET EXPLORER OBSERVATIONS OF HERCULES X-1 OVER A 35 DAY CYCLE</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Leahy, D. A.; Dupuis, Jean, E-mail: leahy@ucalgary.c 2010-06-01 Observations of Hercules X-1 by the Extreme Ultraviolet Explorer covering most of the 35 day cycle are reported here. This is the only long extreme ultraviolet (EUV) observation of Her X-1. Simultaneous X-ray observations with the Rossi X-ray Timing Explorer All-Sky Monitor (RXTE/ASM) X-ray show that Her X-1 is in an X-ray anomalous low state. The first 4 days are also observed with the RXTE proportional counter array (PCA), which shows that the X-ray properties are nearly the same as for normal low states in Her X-1 with flux reduced by a factor of 2. In contrast, the EUV emissionmore » from Her X-1 is reduced by a factor of {approx}4 compared to normal low states. The twisted-tilted accretion disk responsible for the normal 35 day X-ray cycle can be modified to explain this behavior. An increased disk twist reduces the X-ray illumination of HZ Her by a factor of {approx}2 and of the disk surface by a somewhat larger factor, leading to a larger reduction in EUV flux compared to X-ray flux.« less </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015CorRe..34..275B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015CorRe..34..275B">Photoperiod, temperature, and food availability as drivers of the annual reproductive cycle of the sea urchin Echinometra sp. from the Gulf of Aqaba (Red Sea)</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Bronstein, Omri; Loya, Yossi 2015-03-01 In spite of the efforts invested in the search for the environmental factors that regulate discrete breeding periods in marine invertebrates, they remain poorly understood. Here, we present the first account of the annual reproductive cycle of the pantropical sea urchin Echinometra sp. from the Gulf of Aqaba/Eilat (Red Sea) and explore some of the main environmental variables that drive echinoid reproduction. Monthly measurements of gonado-somatic indexes and histological observations of 20 specimens revealed a single seasonal reproductive cycle, with gametogenesis in males and females being highly synchronized. Gametogenesis commenced in June and peak spawning occurred between September and October. Gonado-somatic indexes were significantly correlated with seawater temperatures but not with photoperiod. The latter cycle lagged behind the gonado-somatic cycle by two months, suggesting that the onset of gametogenesis corresponds to shortening day length, while spawning may be driven by warming seawater temperatures. Gonads remained quiescent throughout the winter and spring (January through May) when temperatures were at their lowest. Chlorophyll- a concentrations increased significantly in the months following spawning (October through January). These high concentrations are indicative of high phytoplankton abundance and may reflect the increase in food availability for the developing larvae. Of the external test dimensions, length presented the highest correlation to body weight, indicating length as the best predictor for body size in Echinometra. Neither sexual dimorphism nor size differences between males and females were detected, and the sex ratios were approximately 1:1 in three distant Echinometra populations. Environmentally regulated reproduction, as occurs in sea urchins, might face severe outcomes due to anthropogenic disturbances to the marine environment. Consequently, there is a need to deepen our understanding of the mechanisms that drive and </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ClDy..tmp.2370W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ClDy..tmp.2370W">Eastern equatorial Pacific sea surface temperature annual cycle in the Kiel climate model: simulation benefits from enhancing atmospheric resolution</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Wengel, C.; Latif, M.; Park, W.; Harlaß, J.; Bayr, T. 2018-05-01 A long-standing difficulty of climate models is to capture the annual cycle (AC) of eastern equatorial Pacific (EEP) sea surface temperature (SST). In this study, we first examine the EEP SST AC in a set of integrations of the coupled Kiel Climate Model, in which only atmosphere model resolution differs. When employing coarse horizontal and vertical atmospheric resolution, significant biases in the EEP SST AC are observed. These are reflected in an erroneous timing of the cold tongue's onset and termination as well as in an underestimation of the boreal spring warming amplitude. A large portion of these biases are linked to a wrong simulation of zonal surface winds, which can be traced back to precipitation biases on both sides of the equator and an erroneous low-level atmospheric circulation over land. Part of the SST biases also is related to shortwave radiation biases related to cloud cover biases. Both wind and cloud cover biases are inherent to the atmospheric component, as shown by companion uncoupled atmosphere model integrations forced by observed SSTs. Enhancing atmosphere model resolution, horizontal and vertical, markedly reduces zonal wind and cloud cover biases in coupled as well as uncoupled mode and generally improves simulation of the EEP SST AC. Enhanced atmospheric resolution reduces convection biases and improves simulation of surface winds over land. Analysis of a subset of models from the Coupled Model Intercomparison Project phase 5 (CMIP5) reveals that in these models, very similar mechanisms are at work in driving EEP SST AC biases. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.B13D0637P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.B13D0637P">Soil nitrogen cycling and availability are linked to ammonia oxidizer abundance across a tropical mean annual temperature gradient</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Pierre, S.; Litton, C. M.; Giardina, C. P.; Sparks, J. P.; Groffman, P.; Hewson, I.; Fahey, T. 2016-12-01 Interactions among environmental variables can obfuscate the primary drivers linking soil microbial community function to ecosystem biogeochemistry. These connections are important to understand in order to predict ecosystem responses to global climate change. In particular, the role of mean annual temperature (MAT) in regulating carbon (C) and nitrogen (N) cycling via microbial communities remains unclear. To study these dynamics in situ, we used a a natural elevation gradient of tropical wet montane forest on Mauna Kea, Hawai'i with established permanent plots. Across the gradient, environmental variables besides MAT remain constant. We studied the abundance and activity of the amoA gene, which regulates the rate-limiting step of nitrification, in ammonia oxidizing archaea (AOA) and bacteria (AOB) with relation to N availability and cycling across increasing MAT. Our results show that the abundance of amoA is positively correlated with MAT (p<0.05; r2=0.34) and that MAT and amoA abundance are the primary predictors of nitrate (NO3-) bioavailability (p<0.05). We also found that the relative expression of amoA (cDNA/DNA) is not correlated with MAT or potential net nitrification rate. Our results indicate the direct role of MAT in ammonia oxidizer community structure and demonstrate feedbacks to nutrient availability in forest systems. These findings suggest that forest primary production and carbon cycling may be affected by AOA and AOB responses to rising MAT. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26791726','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26791726">Future ocean hypercapnia driven by anthropogenic amplification of the natural CO2 cycle.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> McNeil, Ben I; Sasse, Tristan P 2016-01-21 High carbon dioxide (CO2) concentrations in sea-water (ocean hypercapnia) can induce neurological, physiological and behavioural deficiencies in marine animals. Prediction of the onset and evolution of hypercapnia in the ocean requires a good understanding of annual variations in oceanic CO2 concentration, but there is a lack of relevant global observational data. Here we identify global ocean patterns of monthly variability in carbon concentration using observations that allow us to examine the evolution of surface-ocean CO2 levels over the entire annual cycle under increasing atmospheric CO2 concentrations. We predict that the present-day amplitude of the natural oscillations in oceanic CO2 concentration will be amplified by up to tenfold in some regions by 2100, if atmospheric CO2 concentrations continue to rise throughout this century (according to the RCP8.5 scenario of the Intergovernmental Panel on Climate Change). The findings from our data are broadly consistent with projections from Earth system climate models. Our predicted amplification of the annual CO2 cycle displays distinct global patterns that may expose major fisheries in the Southern, Pacific and North Atlantic oceans to hypercapnia many decades earlier than is expected from average atmospheric CO2 concentrations. We suggest that these ocean 'CO2 hotspots' evolve as a combination of the strong seasonal dynamics of CO2 concentration and the long-term effective storage of anthropogenic CO2 in the oceans that lowers the buffer capacity in these regions, causing a nonlinear amplification of CO2 concentration over the annual cycle. The onset of ocean hypercapnia (when the partial pressure of CO2 in sea-water exceeds 1,000 micro-atmospheres) is forecast for atmospheric CO2 concentrations that exceed 650 parts per million, with hypercapnia expected in up to half the surface ocean by 2100, assuming a high-emissions scenario (RCP8.5). Such extensive ocean hypercapnia has detrimental implications for </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016Natur.529..383M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016Natur.529..383M">Future ocean hypercapnia driven by anthropogenic amplification of the natural CO2 cycle</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> McNeil, Ben I.; Sasse, Tristan P. 2016-01-01 High carbon dioxide (CO2) concentrations in sea-water (ocean hypercapnia) can induce neurological, physiological and behavioural deficiencies in marine animals. Prediction of the onset and evolution of hypercapnia in the ocean requires a good understanding of annual variations in oceanic CO2 concentration, but there is a lack of relevant global observational data. Here we identify global ocean patterns of monthly variability in carbon concentration using observations that allow us to examine the evolution of surface-ocean CO2 levels over the entire annual cycle under increasing atmospheric CO2 concentrations. We predict that the present-day amplitude of the natural oscillations in oceanic CO2 concentration will be amplified by up to tenfold in some regions by 2100, if atmospheric CO2 concentrations continue to rise throughout this century (according to the RCP8.5 scenario of the Intergovernmental Panel on Climate Change). The findings from our data are broadly consistent with projections from Earth system climate models. Our predicted amplification of the annual CO2 cycle displays distinct global patterns that may expose major fisheries in the Southern, Pacific and North Atlantic oceans to hypercapnia many decades earlier than is expected from average atmospheric CO2 concentrations. We suggest that these ocean ‘CO2 hotspots’ evolve as a combination of the strong seasonal dynamics of CO2 concentration and the long-term effective storage of anthropogenic CO2 in the oceans that lowers the buffer capacity in these regions, causing a nonlinear amplification of CO2 concentration over the annual cycle. The onset of ocean hypercapnia (when the partial pressure of CO2 in sea-water exceeds 1,000 micro-atmospheres) is forecast for atmospheric CO2 concentrations that exceed 650 parts per million, with hypercapnia expected in up to half the surface ocean by 2100, assuming a high-emissions scenario (RCP8.5). Such extensive ocean hypercapnia has detrimental implications for </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.8432P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.8432P">Long term monitoring of landslide: observation gravitational slope cycles</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Palis, Edouard; Lebourg, Thomas; Vidal, Maurin 2016-04-01 Since several years of studies on landslides, we realized the role and subtle interactions that existed between the structural complexity, masses dynamics and complex internal circulation of fluids. Thus, to gain a better understanding of the processes taking place during the evolution of an unstable slope, an observational study is necessary. In this perspective, our team currently monitors slow moving landslide zones. The aim of such a monitoring is to gain a better knowledge of the links between external forcing (meteorological, seismological) and signals going out of the slope (kinematic, vibrations, electrical resistivity). In December 2000, a dramatic event affected the sandy/clayey landslide in the Southern Alpes Maritimes (France). A 10 meters high scarp appeared at the foot of the landslide and affected private yards nearby. This area then became a major concern for local authorities and understand the processes taking place, a scientific challenge. In order to understand the land-sliding reactivations and to quantify the natural cycles of deformations, we analyse the main factors of this complex system. After 10 years of observation we are now able to highlight some of the complex behaviours by the measurement of physical parameters (geophysical monitoring). A permanent 115 m ERT line (5 meters electrode spacing) has been installed and provides an acquisition daily since 2006. The daily acquisitions are now accompanied by continuous measurements from boreholes (thermometers, piezometers, tiltmeters) and pluviometry. We are able to control the whole monitoring from the lab, and all these data are transmitted in real time. The analysis of these large amounts of data over large time series allows the detection of seasonal cycles of surface activity. The deformation taking place can be assimilated to a near-elastic deformation and show a lateral decoupling on both sides of the fault cutting the landslide. These deformation cycles can be associated with the </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.H13I1512H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.H13I1512H">Characterization of seasonal and inter-annual variability in global water bodies using annual MODIS water maps 2000 - 2016</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Hubbard, A. B.; Carroll, M. 2017-12-01 Accurate maps of surface water resources are critical for long-term resource management, characterization of extreme events, and integration into various science products. Unfortunately, most of the currently available surface water products do not adequately represent inter- and intra-annual variation in water extent, resulting from both natural fluctuations in the hydrologic cycle and human activities. To capture this variability, annual water maps were generated from Terra MODIS data at 250 m resolution for the years 2000 through 2016, using the same algorithm employed to generate the previously released MOD44W Collection 5 static water mask (Carroll et al., 2009). Following efforts to verify the data and remove false positives, the final maps were submitted to the Land Processes DAAC for publication as MOD44W Collection 6.1. Analysis of these maps indicate that only about two thirds of inland water pixels were persistent throughout all 16 years of data, meaning that roughly one third of the surface water detected in this period displayed some degree of inter-annual variation. In addition to the annual datasets, water observations were aggregated by quarter for each year from 2003 through 2016 using the same algorithm and observations from both Terra and Aqua. Analysis of these seasonal maps is ongoing, but preliminary investigation indicates they capture dramatic intra-annual fluctuations of water extent in many regions. In cloudy regions, it is difficult or impossible to consistently measure this intra-annual variation without the twice-daily temporal resolution of the MODIS sensors. While the moderate spatial resolution of MODIS is a constraint, these datasets are suitable for studying such fluctuations in medium to large water bodies, or at regional to global scales. These maps also provide a baseline record of historical surface water resources, against which future change can be compared. Finally, comparisons with the MOD44W Collection 5 static water mask </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMSH52A..04L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMSH52A..04L">MAVEN Upstream Observations of the Cycle 24 Space Weather Conditions at Mars</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Lee, C. O.; Hara, T.; Halekas, J. S.; Thiemann, E.; Curry, S.; Lillis, R. J.; Larson, D. E.; Espley, J. R.; Gruesbeck, J.; Eparvier, F. G.; Li, Y.; Jian, L.; Luhmann, J. G.; Jakosky, B. M. 2016-12-01 The Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft went into orbit around Mars during the height of the activity phase of Solar Cycle 24. The mission was designed in part to study the response of the upper atmosphere, ionosphere, and magnetosphere of Mars to solar and solar wind inputs. When MAVEN is on the Martian dayside and orbiting around its apoapsis altitude of 6200 km, the suite of instruments onboard can measure the solar wind plasma (density, velocity), interplanetary magnetic field (magnitude and direction), and particle counts of solar energetic particles (SEPs), as well as the EUV solar irradiance. We will present an overview of the upstream conditions observed to date and highlight a number of Mars-impacting space weather events due to ICMEs and SEPs. We will also present events that are triggered by corotating interaction regions (CIRs), which become more prominent beyond 1 AU and are the dominant heliospheric structures during the declining phase of the solar cycle. As part of the discussion, we will compare and contrast observations from MAVEN and ACE/WIND or STEREO-A during periods when Mars and the 1-AU observer were in solar opposition or nearly aligned along the solar wind Parker spiral. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020080808','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020080808">Decadal Changes in Global Ocean Annual Primary Production</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Gregg, Watson; Conkright, Margarita E.; Behrenfeld, Michael J.; Ginoux, Paul; Casey, Nancy W.; Koblinsky, Chester J. (Technical Monitor) 2002-01-01 The Sea-viewing Wide Field-of-View Sensor (SeaWiFS) has produced the first multi-year time series of global ocean chlorophyll observations since the demise of the Coastal Zone Color Scanner (CZCS) in 1986. Global observations from 1997-present from SeaWiFS combined with observations from 1979-1986 from the CZCS should in principle provide an opportunity to observe decadal changes in global ocean annual primary production, since chlorophyll is the primary driver for estimates of primary production. However, incompatibilities between algorithms have so far precluded quantitative analysis. We have developed and applied compatible processing methods for the CZCS, using modern advances in atmospheric correction and consistent bio-optical algorithms to advance the CZCS archive to comparable quality with SeaWiFS. We applied blending methodologies, where in situ data observations are incorporated into the CZCS and SeaWiFS data records, to provide improvement of the residuals. These re-analyzed, blended data records provide maximum compatibility and permit, for the first time, a quantitative analysis of the changes in global ocean primary production in the early-to-mid 1980's and the present, using synoptic satellite observations. An intercomparison of the global and regional primary production from these blended satellite observations is important to understand global climate change and the effects on ocean biota. Photosynthesis by chlorophyll-containing phytoplankton is responsible for biotic uptake of carbon in the oceans and potentially ultimately from the atmosphere. Global ocean annual primary decreased from the CZCS record to SeaWiFS, by nearly 6% from the early 1980s to the present. Annual primary production in the high latitudes was responsible for most of the decadal change. Conversely, primary production in the low latitudes generally increased, with the exception of the tropical Pacific. The differences and similarities of the two data records provide evidence </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.H13C1216A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.H13C1216A">A view of annual water quality cycle and inter-annual variations in agricultural headwater catchment (Kervidy-Naizin, France)</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Aubert, A.; Gascuel-odoux, C.; Merot, P.; Grimaldi, C.; Gruau, G.; Ruiz, L. 2011-12-01 Climatic conditions impact biotransformation and transfer of solutes. Therefore, they modify solute emissions in streams. Studying these modifications requires long term and detailed monitoring of both internal processes and river loads, which are rarely combined. The Kervidy-Naizin catchment, implemented in 1993, is part of the French network of catchment for environmental research (SOERE RBV, focused on the Critical Zone). It is an intensive agricultural catchment located in a temperate climate in Western France (Brittany) (Molenat et al., 2008; Morel et al., 2009). It presents shallow aquifers due to impervious bedrock. Both hydrology and water chemistry are monitored with a daily time step since 2000-01, as well as possible explanatory data (land use, meteorology, etc.). Concentrations in major anions in this catchment are extremely high, which make people call it a "saturated" catchment. We identified annual patterns for chloride, sulphate, dissolved organic and inorganic carbon and nitrate concentration variations. First, we considered the complete set of concentration data as function of the time. From that, we foresaw 3 cyclic temporal patterns. Then, from representing the concentrations as function of meteorological parameters, intra-annual hysteretic variations and their inter-annual variations were clearly identified. Our driving question is to know if and how climatic conditions are responsible for variations of the patterns in and between years. In winter, i.e. rainy and cold period, rainfall is closely linked to discharge because of a direct recharge to the shallow groundwater. Reversely, in transition periods (spring and fall) and hot periods, both rainfall and temperature influences discharge in relation to their range of variations. Moreover, biological processes, driven by temperature and wetness, also act during these periods. On the whole, we can emphasize the specificity of water chemistry patterns for each element. Noticeable differences </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active">10</li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active">11</li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1346297-tropical-rain-belts-annual-cycle-continent-model-intercomparison-project-tracmip','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1346297-tropical-rain-belts-annual-cycle-continent-model-intercomparison-project-tracmip">The tropical rain belts with an annual cycle and a continent model intercomparison project: TRACMIP</a> <a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a> Voigt, Aiko; Biasutti, Michela; Scheff, Jacob; ... 2016-11-16 This paper introduces the Tropical Rain belts with an Annual cycle and a Continent Model Intercomparison Project (TRACMIP). TRACMIP studies the dynamics of tropical rain belts and their response to past and future radiative forcings through simulations with 13 comprehensive and one simplified atmosphere models coupled to a slab ocean and driven by seasonally-varying insolation. Five idealized experiments, two with an aquaplanet setup and three with a setup with an idealized tropical continent, fill the space between prescribed-SST aquaplanet simulations and realistic simulations provided by CMIP5/6. The simulations reproduce key features of the present-day climate and expected future climate change,more » including an annual-mean intertropical convergence zone (ITCZ) that is located north of the equator and Hadley cells and eddy-driven jets that are similar to the present-day climate. Quadrupling CO 2 leads to a northward ITCZ shift and preferential warming in Northern high-latitudes. The simulations show interesting CO 2-induced changes in the seasonal excursion of the ITCZ and indicate a possible state-dependence of climate sensitivity. The inclusion of an idealized continent modulates both the control climate and the response to increased CO 2; for example it reduces the northward ITCZ shift associated with warming and, in some models, climate sensitivity. In response to eccentricity-driven seasonal insolation changes, seasonal changes in oceanic rainfall are best characterized as a meridional dipole, while seasonal continental rainfall changes tend to be symmetric about the equator. Finally, this survey illustrates TRACMIP’s potential to engender a deeper understanding of global and regional climate phenomena and to address pressing questions on past and future climate change.« less </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20170011197&hterms=rain&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Drain','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20170011197&hterms=rain&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Drain">The Tropical Rain Belts with an Annual Cycle and a Continent Model Intercomparison Project: TRACMIP</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Voigt, Aiko; Biasutti, Michela; Scheff, Jacob; Bader, Juergen; Bordoni, Simona; Codron, Francis; Dixon, Ross D.; Jonas, Jeffrey; Kang, Sarah M.; Klingaman, Nicholas P.; <a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20170011197'); toggleEditAbsImage('author_20170011197_show'); toggleEditAbsImage('author_20170011197_hide'); "> <img style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_20170011197_show"> <img style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_20170011197_hide"> 2016-01-01 This paper introduces the Tropical Rain belts with an Annual cycle and a Continent Model Intercomparison Project (TRACMIP). TRACMIP studies the dynamics of tropical rain belts and their response to past and future radiative forcings through simulations with 13 comprehensive and one simplified atmosphere models coupled to a slab ocean and driven by seasonally-varying insolation. Five idealized experiments, two with an aquaplanet setup and three with a setup with an idealized tropical continent, fill the space between prescribed-SST aquaplanet simulations and realistic simulations provided by CMIP5/6. The simulations reproduce key features of present-day climate and expected future climate change, including an annual-mean intertropical convergence zone (ITCZ) that is located north of the equator and Hadley cells and eddy-driven jets that are similar to present-day climate. Quadrupling CO2 leads to a northward ITCZ shift and preferential warming in Northern high-latitudes. The simulations show interesting CO2-induced changes in the seasonal excursion of the ITCZ and indicate a possible state-dependence of climate sensitivity. The inclusion of an idealized continent modulates both the control climate and the response to increased CO2; for example, it reduces the northward ITCZ shift associated with warming and, in some models, climate sensitivity. In response to eccentricity-driven seasonal insolation changes, seasonal changes in oceanic rainfall are best characterized as a meridional dipole, while seasonal continental rainfall changes tend to be symmetric about the equator. This survey illustrates TRACMIP's potential to engender a deeper understanding of global and regional climate and to address questions on past and future climate change. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015E%26PSL.428...44C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015E%26PSL.428...44C">Solar cycles and depositional processes in annual 10Be from two varved lake sediment records</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Czymzik, Markus; Muscheler, Raimund; Brauer, Achim; Adolphi, Florian; Ott, Florian; Kienel, Ulrike; Dräger, Nadine; Słowiński, Michał; Aldahan, Ala; Possnert, Göran 2015-10-01 Beryllium 10 concentrations (10Becon) were measured at annual resolution from varved sediment cores of Lakes Tiefer See (TSK) and Czechowskie (JC) for the period 1983-2009 (∼solar cycles 22 and 23). Calibrating the 10Becon time-series against complementing proxy records from the same archive as well as local precipitation and neutron monitor data, reflecting solar forced changes in atmospheric radionuclide production, allowed (i) identifying the main depositional processes and (ii) evaluating the potential for solar activity reconstruction. 10Becon in TSK and JC sediments are significantly correlated to varying neutron monitor counts (TSK: r = 0.5, p = 0.05, n = 16; JC: r = 0.46, p = 0.03, n = 22). However, the further correlations with changes in organic carbon contents in TSK as well as varying organic carbon and detrital matter contents in JC point to catchment specific biases in the 10Becon time-series. In an attempt to correct for these biases multiple regression analysis was applied to extract an atmospheric 10Be production signal (10Beatmosphere). To increase the signal to noise ratio a 10Be composite record (10Becomposite) was calculated from the TSK and JC 10Beatmosphere time-series. 10Becomposite is significantly correlated to variations in the neutron monitor record (r = 0.49, p = 0.01, n = 25) and matches the expected amplitude changes in 10Be production between solar cycle minima and maxima. This calibration study on 10Be from two sites indicates the large potential but also, partly site-specific, limitations of 10Be in varved lake sediments for solar activity reconstruction. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1393573','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1393573">Cloud vertical distribution from combined surface and space radar-lidar observations at two Arctic atmospheric observatories</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Liu, Yinghui; Shupe, Matthew D.; Wang, Zhien Detailed and accurate vertical distributions of cloud properties (such as cloud fraction, cloud phase, and cloud water content) and their changes are essential to accurately calculate the surface radiative flux and to depict the mean climate state. Surface and space-based active sensors including radar and lidar are ideal to provide this information because of their superior capability to detect clouds and retrieve cloud microphysical properties. In this study, we compare the annual cycles of cloud property vertical distributions from space-based active sensors and surface-based active sensors at two Arctic atmospheric observatories, Barrow and Eureka. Based on the comparisons, we identifymore » the sensors' respective strengths and limitations, and develop a blended cloud property vertical distribution by combining both sets of observations. Results show that surface-based observations offer a more complete cloud property vertical distribution from the surface up to 11 km above mean sea level (a.m.s.l.) with limitations in the middle and high altitudes; the annual mean total cloud fraction from space-based observations shows 25-40 % fewer clouds below 0.5 km than from surface-based observations, and space-based observations also show much fewer ice clouds and mixed-phase clouds, and slightly more liquid clouds, from the surface to 1 km. In general, space-based observations show comparable cloud fractions between 1 and 2 km a.m.s.l., and larger cloud fractions above 2 km a.m.s.l. than from surface-based observations. A blended product combines the strengths of both products to provide a more reliable annual cycle of cloud property vertical distributions from the surface to 11 km a.m.s.l. This information can be valuable for deriving an accurate surface radiative budget in the Arctic and for cloud parameterization evaluation in weather and climate models. Cloud annual cycles show similar evolutions in total cloud fraction and ice cloud fraction, and lower liquid </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1393573-cloud-vertical-distribution-from-combined-surface-space-radar-lidar-observations-two-arctic-atmospheric-observatories','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1393573-cloud-vertical-distribution-from-combined-surface-space-radar-lidar-observations-two-arctic-atmospheric-observatories">Cloud vertical distribution from combined surface and space radar-lidar observations at two Arctic atmospheric observatories</a> <a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a> Liu, Yinghui; Shupe, Matthew D.; Wang, Zhien; ... 2017-05-16 Detailed and accurate vertical distributions of cloud properties (such as cloud fraction, cloud phase, and cloud water content) and their changes are essential to accurately calculate the surface radiative flux and to depict the mean climate state. Surface and space-based active sensors including radar and lidar are ideal to provide this information because of their superior capability to detect clouds and retrieve cloud microphysical properties. In this study, we compare the annual cycles of cloud property vertical distributions from space-based active sensors and surface-based active sensors at two Arctic atmospheric observatories, Barrow and Eureka. Based on the comparisons, we identifymore » the sensors' respective strengths and limitations, and develop a blended cloud property vertical distribution by combining both sets of observations. Results show that surface-based observations offer a more complete cloud property vertical distribution from the surface up to 11 km above mean sea level (a.m.s.l.) with limitations in the middle and high altitudes; the annual mean total cloud fraction from space-based observations shows 25-40 % fewer clouds below 0.5 km than from surface-based observations, and space-based observations also show much fewer ice clouds and mixed-phase clouds, and slightly more liquid clouds, from the surface to 1 km. In general, space-based observations show comparable cloud fractions between 1 and 2 km a.m.s.l., and larger cloud fractions above 2 km a.m.s.l. than from surface-based observations. A blended product combines the strengths of both products to provide a more reliable annual cycle of cloud property vertical distributions from the surface to 11 km a.m.s.l. This information can be valuable for deriving an accurate surface radiative budget in the Arctic and for cloud parameterization evaluation in weather and climate models. Cloud annual cycles show similar evolutions in total cloud fraction and ice cloud fraction, and lower liquid </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.H13K1536M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.H13K1536M">Performance of CMIP3 and CMIP5 GCMs to simulate observed rainfall characteristics over the Western Himalayan region</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Meher, J. K.; Das, L. 2017-12-01 The Western Himalayan Region (WHR) was subject to a significant negative trend in the annual and monsoon rainfall during 1902-2005. Annual and seasonal rainfall change over WHR of India was estimated using 22 rain gauge station rainfall data from the India Meteorological Department. The performance of 13 global climate models (GCMs) from the coupled model intercomparison project phase 3 (CMIP3) and 42 GCMs from CMIP5 was evaluated through multiple analysis: the evaluation of the mean annual cycle, annual cycles of interannual variability, spatial patterns, trends and signal-to-noise ratio. In general, CMIP5 GCMs were more skillful in terms of simulating the annual cycle of interannual variability compared to CMIP3 GCMs. The CMIP3 GCMs failed to reproduce the observed trend whereas 50% of the CMIP5 GCMs reproduced the statistical distribution of short-term (30-years) trend-estimates than for the longer term (99-years). GCMs from both CMIP3 and CMIP5 were able to simulate the spatial distribution of observed rainfall in pre-monsoon and winter months. Based on performance, each model of CMIP3 and CMIP5 was given an overall rank, which puts the high resolution version of the MIROC3.2 model (MIROC3.2 hires) and MIROC5 at the top in CMIP3 and CMIP5 respectively. Robustness of the ranking was judged through a sensitivity analysis, which indicated that ranks were independent during the process of adding or removing any individual method. It also revealed that trend analysis was not a robust method of judging performances of the model as compared to other methods. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23953054','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23953054">Tundra ecosystems observed to be CO2 sources due to differential amplification of the carbon cycle.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Belshe, E F; Schuur, E A G; Bolker, B M 2013-10-01 Are tundra ecosystems currently a carbon source or sink? What is the future trajectory of tundra carbon fluxes in response to climate change? These questions are of global importance because of the vast quantities of organic carbon stored in permafrost soils. In this meta-analysis, we compile 40 years of CO2 flux observations from 54 studies spanning 32 sites across northern high latitudes. Using time-series analysis, we investigated if seasonal or annual CO2 fluxes have changed over time, and whether spatial differences in mean annual temperature could help explain temporal changes in CO2 flux. Growing season net CO2 uptake has definitely increased since the 1990s; the data also suggest (albeit less definitively) an increase in winter CO2 emissions, especially in the last decade. In spite of the uncertainty in the winter trend, we estimate that tundra sites were annual CO2 sources from the mid-1980s until the 2000s, and data from the last 7 years show that tundra continue to emit CO2 annually. CO2 emissions exceed CO2 uptake across the range of temperatures that occur in the tundra biome. Taken together, these data suggest that despite increases in growing season uptake, tundra ecosystems are currently CO2 sources on an annual basis. © 2013 John Wiley & Sons Ltd/CNRS. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.B31B1981G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.B31B1981G">Impacts of disturbance history on annual carbon stocks and fluxes in southeastern US forests during 1986-2010 using remote sensing, forest inventory data, and a carbon cycle model</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Gu, H.; Zhou, Y.; Williams, C. A. 2017-12-01 Accurate assessment of forest carbon storage and uptake is central to policymaking aimed at mitigating climate change and understanding the role forests play in the global carbon cycle. Disturbance events are highly heterogeneous in space and time, impacting forest carbon dynamics and challenging the quantification and reporting of carbon stocks and fluxes. This study documents annual carbon stocks and fluxes from 1986 and 2010 mapped at 30-m resolution across southeastern US forests, characterizing how they respond to disturbances and ensuing regrowth. Forest inventory data (FIA) are used to parameterize a carbon cycle model (CASA) to represent post-disturbance carbon trajectories of carbon pools and fluxes with time following harvest, fire and bark beetle disturbances of varying severity and across forest types and site productivity settings. Time since disturbance at 30 meters is inferred from two remote-sensing data sources: disturbance year (NAFD, MTBS and ADS) and biomass (NBCD 2000) intersected with FIA-derived curves of biomass accumulation with stand age. All of these elements are combined to map carbon stocks and fluxes at a 30-m resolution for the year 2010, and to march backward in time for continuous, annual reporting. Results include maps of annual carbon stocks and fluxes for forests of the southeastern US, and analysis of spatio-temporal patterns of carbon sources/sinks at local and regional scales. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19970026593','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19970026593">Annual and Semi-Annual Temperature Oscillations in the Upper Mesosphere</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Niciejewski, R. J.; Killeen, T. L. 1995-01-01 Fourier transform spectrometer observations of the mesosphere have been performed at the University of Michigan (latitude: 42.5 N) on a long term basis. A database of near infrared Meinel hydroxyl spectra has been accumulated from which rotational temperatures have been determined. Harmonic analysis of one-day averaged temperatures for the period 1992.0 to 1994.5 has shown a distinct annual and semi-annual variation. Subsequent fitting of a five term periodic function characterizing the annual and semi-annual temperature oscillations to the daily averaged temperatures was performed. The resultant mean temperature and the amplitudes and phases of the annual and semi-annual variations are shown to coincide with an emission height slightly above 85 km which is consistent with the mean rocket derived altitude for peak nocturnal hydroxyl emission. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.A21I2265W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.A21I2265W">The Seasonal cycle of the Tropical Lower Stratospheric Water Vapor in Chemistry-Climate Models in Comparison with Observations</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Wang, X.; Dessler, A. E. 2017-12-01 The seasonal cycle is one of the key features of the tropical lower stratospheric water vapor, so it is important that the climate models reproduce it. In this analysis, we evaluate how well the Goddard Earth Observing System Chemistry Climate Model (GEOSCCM) and the Whole Atmosphere Community Climate Model (WACCM) reproduce the seasonal cycle of tropical lower stratospheric water vapor. We do this by comparing the models to observations from the Microwave Limb Sounder (MLS) and the European Centre for Medium-Range Weather Forecasts (ECMWF) ERA-Interim (ERAi). We also evaluate if the chemistry-climate models (CCMs) reproduce the key transport and dehydration processes that regulate the seasonal cycle using a forward, domain filling, diabatic trajectory model. Finally, we explore the changes of the seasonal cycle during the 21st century in the two CCMs. Our results show general agreement in the seasonal cycles from the MLS, the ERAi, and the CCMs. Despite this agreement, there are some clear disagreements between the models and the observations on the details of transport and dehydration in the TTL. Finally, both the CCMs predict a moister seasonal cycle by the end of the 21st century. But they disagree on the changes of the seasonal amplitude, which is predicted to increase in the GEOSCCM and decrease in the WACCM. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29030121','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29030121">Estimation of optimal biomass fraction measuring cycle formunicipal solid waste incineration facilities in Korea.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Kang, Seongmin; Cha, Jae Hyung; Hong, Yoon-Jung; Lee, Daekyeom; Kim, Ki-Hyun; Jeon, Eui-Chan 2018-01-01 This study estimates the optimum sampling cycle using a statistical method for biomass fraction. More than ten samples were collected from each of the three municipal solid waste (MSW) facilities between June 2013 and March 2015 and the biomass fraction was analyzed. The analysis data were grouped into monthly, quarterly, semi-annual, and annual intervals and the optimum sampling cycle for the detection of the biomass fraction was estimated. Biomass fraction data did not show a normal distribution. Therefore, the non-parametric Kruskal-Wallis test was applied to compare the average values for each sample group. The Kruskal-Wallis test results showed that the average monthly, quarterly, semi-annual, and annual values for all three MSW incineration facilities were equal. Therefore, the biomass fraction at the MSW incineration facilities should be calculated on a yearly cycle which is the longest period of the temporal cycles tested. Copyright © 2017 Elsevier Ltd. All rights reserved. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19900038314&hterms=water+cycle&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dwater%2Bcycle','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19900038314&hterms=water+cycle&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dwater%2Bcycle">The role of water ice clouds in the Martian hydrologic cycle</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> James, Philip B. 1990-01-01 A one-dimensional model for the seasonal cycle of water on Mars has been used to investigate the direction of the net annual transport of water on the planet and to study the possible role of water ice clouds, which are included as an independent phase in addition to ground ice and water vapor, in the cycle. The calculated seasonal and spatial patterns of occurrence of water ice clouds are qualitatively similar to the observed polar hoods, suggesting that these polar clouds are, in fact, an important component of water cycle. A residual dry ice in the south acts as a cold trap which, in the absence of sources other than the caps, will ultimately attract the water ice from the north cap; however, in the presence of a source of water in northern midlatitudes during spring, it is possible that the observed distribution of vapor and ice can be in a steady state even if a residual CO2 cap is a permanent feature of the system. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012ERL.....7b4008C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012ERL.....7b4008C">From drought to flooding: understanding the abrupt 2010-11 hydrological annual cycle in the Amazonas River and tributaries</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Carlo Espinoza, Jhan; Ronchail, Josyane; Loup Guyot, Jean; Junquas, Clementine; Drapeau, Guillaume; Martinez, Jean Michel; Santini, William; Vauchel, Philippe; Lavado, Waldo; Ordoñez, Julio; Espinoza, Raúl 2012-06-01 In this work we document and analyze the hydrological annual cycles characterized by a rapid transition between low and high flows in the Amazonas River (Peruvian Amazon) and we show how these events, which may impact vulnerable riverside residents, are related to regional climate variability. Our analysis is based on comprehensive discharge, rainfall and average suspended sediment data sets. Particular attention is paid to the 2010-11 hydrological year, when an unprecedented abrupt transition from the extreme September 2010 drought (8300 m3 s-1) to one of the four highest discharges in April 2011 (49 500 m3 s-1) was recorded at Tamshiyacu (Amazonas River). This unusual transition is also observed in average suspended sediments. Years with a rapid increase in discharge are characterized by negative sea surface temperature anomalies in the central equatorial Pacific during austral summer, corresponding to a La Niña-like mode. It originates a geopotential height wave train over the subtropical South Pacific and southeastern South America, with a negative anomaly along the southern Amazon and the southeastern South Atlantic convergence zone region. As a consequence, the monsoon flux is retained over the Amazon and a strong convergence of humidity occurs in the Peruvian Amazon basin, favoring high rainfall and discharge. These features are also reported during the 2010-11 austral summer, when an intense La Niña event characterized the equatorial Pacific. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013lcdu.confE....K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013lcdu.confE....K">The Life Cycle of Dust in the Universe: Observations, Theory, and Laboratory Experiments</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Kemper, Ciska; Andersen, Anja; Baes, Maarten; Gomez, Haley; Watson, Darach This meeting addresses the life cycle of dust in the Universe, which covers the formation, evolution and destruction of dust in a range of environments, ranging from the smallest to the largest scales. Bringing together observational and theoretical astrophysicists as well as meteoriticists and experimentalists allows for a cross-disciplinary dialogue. The meeting follows a successful tradition of astrophysical dust meetings, starting in Albany in 1972, with the latest edition "Cosmic Dust: Near and Far" organized by Th. Henning taking place in Heidelberg in 2008. Since that meeting, the field of dust astrophysics has made major leaps forward with the host of data arriving from such missions as the infrared space telescopes Spitzer and Herschel, and the sample return mission, Stardust, which took dust samples from comet Wild-2. The largest telescope on Earth, ALMA, has also recently come online, allowing for investigations into the origin of dust in the Universe, making this is excellent time to review the status of the field of dust astrophysics. The meeting aims to create an environment in which all aspects of the life cycle of dust are discussed, from an astrophysical, chemical and mineralogical perspective, and its effect on a range of environments. Observational insights, theoretical models and experimental approaches all contribute to our view of the life cycle of dust, and the meeting addresses new developments and future projects in all these areas. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.A51A0108B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.A51A0108B">The effect of anthropogenic emissions corrections on the seasonal cycle of atmospheric CO2</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Brooks, B. J.; Hoffman, F. M.; Mills, R. T.; Erickson, D. J.; Blasing, T. J. 2009-12-01 A previous study (Erickson et al. 2008) approximated the monthly global emission estimates of anthropogenic CO2 by applying a 2-harmonic Fourier expansion with coefficients as a function of latitude to annual CO2 flux estimates derived from United States data (Blasing et al. 2005) that were extrapolated globally. These monthly anthropogenic CO2 flux estimates were used to model atmospheric concentrations using the NASA GEOS-4 data assimilation system. Local variability in the amplitude of the simulated CO2 seasonal cycle were found to be on the order of 2-6 ppmv. Here we used the same Fourier expansion to seasonally adjust the global annual fossil fuel CO2 emissions from the SRES A2 scenario. For a total of four simulations, both the annual and seasonalized fluxes were advected in two configurations of the NCAR Community Atmosphere Model (CAM) used in the Carbon-Land Model Intercomparison Project (C-LAMP). One configuration used the NCAR Community Land Model (CLM) coupled with the CASA‧ (carbon only) biogeochemistry model and the other used CLM coupled with the CN (coupled carbon and nitrogen cycles) biogeochemistry model. All four simulations were forced with observed sea surface temperatures and sea ice concentrations from the Hadley Centre and a prescribed transient atmospheric CO2 concentration for the radiation and land forcing over the 20th century. The model results exhibit differences in the seasonal cycle of CO2 between the seasonally corrected and uncorrected simulations. Moreover, because of differing energy and water feedbacks between the atmosphere model and the two land biogeochemistry models, features of the CO2 seasonal cycle were different between these two model configurations. This study reinforces previous findings that suggest that regional near-surface atmospheric CO2 concentrations depend strongly on the natural sources and sinks of CO2, but also on the strength of local anthropogenic CO2 emissions and geographic position. This work further </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ERL....11e4013H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ERL....11e4013H">Process contributions of Australian ecosystems to interannual variations in the carbon cycle</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Haverd, Vanessa; Smith, Benjamin; Trudinger, Cathy 2016-05-01 New evidence is emerging that semi-arid ecosystems dominate interannual variability (IAV) of the global carbon cycle, largely via fluctuating water availability associated with El Niño/Southern Oscillation. Recent evidence from global terrestrial biosphere modelling and satellite-based inversion of atmospheric CO2 point to a large role of Australian ecosystems in global carbon cycle variability, including a large contribution from Australia to the record land sink of 2011. However the specific mechanisms governing this variability, and their bioclimatic distribution within Australia, have not been identified. Here we provide a regional assessment, based on best available observational data, of IAV in the Australian terrestrial carbon cycle and the role of Australia in the record land sink anomaly of 2011. We find that IAV in Australian net carbon uptake is dominated by semi-arid ecosystems in the east of the continent, whereas the 2011 anomaly was more uniformly spread across most of the continent. Further, and in contrast to global modelling results suggesting that IAV in Australian net carbon uptake is amplified by lags between production and decomposition, we find that, at continental scale, annual variations in production are dampened by annual variations in decomposition, with both fluxes responding positively to precipitation anomalies. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ERL....11i4010L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ERL....11i4010L">Recent trends in vegetation greenness in China significantly altered annual evapotranspiration and water yield</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Liu, Yibo; Xiao, Jingfeng; Ju, Weimin; Xu, Ke; Zhou, Yanlian; Zhao, Yuntai 2016-09-01 There has been growing evidence that vegetation greenness has been increasing in many parts of the northern middle and high latitudes including China during the last three to four decades. However, the effects of increasing vegetation greenness particularly afforestation on the hydrological cycle have been controversial. We used a process-based ecosystem model and a satellite-derived leaf area index (LAI) dataset to examine how the changes in vegetation greenness affected annual evapotranspiration (ET) and water yield for China over the period from 2000 to 2014. Significant trends in vegetation greenness were observed in 26.1% of China’s land area. We used two model simulations driven with original and detrended LAI, respectively, to assess the effects of vegetation ‘greening’ and ‘browning’ on terrestrial ET and water yield. On a per-pixel basis, vegetation greening increased annual ET and decreased water yield, while vegetation browning reduced ET and increased water yield. At the large river basin and national scales, the greening trends also had positive effects on annual ET and had negative effects on water yield. Our results showed that the effects of the changes in vegetation greenness on the hydrological cycle varied with spatial scale. Afforestation efforts perhaps should focus on southern China with larger water supply given the water crisis in northern China and the negative effects of vegetation greening on water yield. Future studies on the effects of the greenness changes on the hydrological cycle are needed to account for the feedbacks to the climate. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19850061220&hterms=life+cycles&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dlife%2Bcycles','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19850061220&hterms=life+cycles&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dlife%2Bcycles">The observed life cycle of a baroclinic instability</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Randel, W. J.; Stanford, J. L. 1985-01-01 Medium-scale waves (zonal wavenumbers 4-7) frequently dominate Southern Hemisphere summer circulation patterns. Randel and Stanford have studied the dynamics of these features, demonstrating that the medium-scale waves result from baroclinic excitation and exhibit well-defined life cycles. This study details the evolution of the medium-scale waves during a particular life cycle. The specific case chosen exhibits a high degree of zonal symmetry, prompting study based upon zonally averaged diagnostics. An analysis of the medium-scale wave energetics reveals a well-defined life cycle of baroclinic growth, maturity, and barotropic decay. Eliassen-Palm flux diagrams detail the daily wave structure and its interaction with the zonally-averaged flow. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMSA54A..03W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMSA54A..03W">Comparison of Model and Observations of Middle Atmospheric HOx Response to Solar 27-day Cycles: Quantifying Model Uncertainties due to Photochemistry</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Wang, S.; Li, K. F.; Shia, R. L.; Yung, Y. L.; Sander, S. P. 2016-12-01 HO2 and OH (known as odd oxygen HOx), play an important role in middle atmospheric chemistry, in particular, O3 destruction through catalytic HOx reaction cycles. Due to their photochemical production and short chemical lifetimes, HOx species response rapidly to solar UV irradiance changes during solar cycles, resulting in variability in the corresponding O3 chemistry. Observational evidences for both OH and HO2 variability due to solar cycles have been reported. However, puzzling discrepancies remain. In particular, the large discrepancy between model and observations of solar 11-year cycle signal in OH and the significantly different model results when adopting different solar spectral irradiance (SSI) [Wang et al., 2013] suggest that both uncertainties in SSI variability and uncertainties in our current understanding of HOx-O3 chemistry could contribute to the discrepancy. Since the short-term SSI variability (e.g. changes during solar 27-day cycles) has little uncertainty, investigating 27-day solar cycle signals in HOx allows us to simplify the complex problem and to focus on the uncertainties in chemistry alone. We use the Caltech-JPL photochemical model to simulate observed HOx variability during 27-day cycles. The comparison between Aura Microwave Limb Sounder (MLS) observations and our model results (using standard chemistry and "adjusted chemistry", respectively) will be discussed. A better understanding of uncertainties in chemistry will eventually help us separate the contribution of chemistry from contributions of SSI uncertainties to the complex discrepancy between model and observations of OH responses to solar 11-year cycles. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.H43A1308F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.H43A1308F">Potential Seasonal Predictability of Water Cycle in Observations and Reanalysis</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Feng, X.; Houser, P. 2012-12-01 Identification of predictability of water cycle variability is crucial for climate prediction, water resources availability, ecosystem management and hazard mitigation. An analysis that can assess the potential skill in seasonal prediction was proposed by the authors, named as analysis of covariance (ANOCOVA). This method tests whether interannual variability of seasonal means exceeds that due to weather noise under the null hypothesis that seasonal means are identical every year. It has the advantage of taking into account autocorrelation structure in the daily time series but also accounting for the uncertainty of the estimated parameters in the significance test. During the past several years, multiple reanalysis datasets have become available for studying climate variability and understanding climate system. We are motivated to compare the potential predictability of water cycle variation from different reanalysis datasets against observations using the newly proposed ANOCOVA method. The selected eight reanalyses include the National Centers for Environmental Prediction-National Center for Atmospheric Research (NCEP/NCAR) 40-year Reanalysis Project (NNRP), the National Centers for Environmental Prediction-Department of Energy (NCEP/DOE) Reanalysis Project (NDRP), the European Centre for Medium-Range Weather Forecasts (ECMWF) 40-year Reanalysis, The Japan Meteorological Agency 25-year Reanalysis Project (JRA25), the ECMWF) Interim Reanalysis (ERAINT), the NCEP Climate Forecast System Reanalysis (CFSR), the National Aeronautics and Space Administration (NASA) Modern-Era Retrospective Analysis for Research and Applications (MERRA), and the National Oceanic and Atmospheric Administration-Cooperative Institute for Research in Environmental Sciences (NOAA/CIRES) 20th Century Reanalysis Version 2 (20CR). For key water cycle components, precipitation and evaporation, all reanalyses consistently show high fraction of predictable variance in the tropics, low </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active">11</li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active">12</li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMGC21C0953M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMGC21C0953M">CMIP5 land surface models systematically underestimate inter-annual variability of net ecosystem exchange in semi-arid southwestern North America.</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> MacBean, N.; Scott, R. L.; Biederman, J. A.; Vuichard, N.; Hudson, A.; Barnes, M.; Fox, A. M.; Smith, W. K.; Peylin, P. P.; Maignan, F.; Moore, D. J. 2017-12-01 Recent studies based on analysis of atmospheric CO2 inversions, satellite data and terrestrial biosphere model simulations have suggested that semi-arid ecosystems play a dominant role in the interannual variability and long-term trend in the global carbon sink. These studies have largely cited the response of vegetation activity to changing moisture availability as the primary mechanism of variability. However, some land surface models (LSMs) used in these studies have performed poorly in comparison to satellite-based observations of vegetation dynamics in semi-arid regions. Further analysis is therefore needed to ensure semi-arid carbon cycle processes are well represented in global scale LSMs before we can fully establish their contribution to the global carbon cycle. In this study, we evaluated annual net ecosystem exchange (NEE) simulated by CMIP5 land surface models using observations from 20 Ameriflux sites across semi-arid southwestern North America. We found that CMIP5 models systematically underestimate the magnitude and sign of NEE inter-annual variability; therefore, the true role of semi-arid regions in the global carbon cycle may be even more important than previously thought. To diagnose the factors responsible for this bias, we used the ORCHIDEE LSM to test different climate forcing data, prescribed vegetation fractions and model structures. Climate and prescribed vegetation do contribute to uncertainty in annual NEE simulations, but the bias is primarily caused by incorrect timing and magnitude of peak gross carbon fluxes. Modifications to the hydrology scheme improved simulations of soil moisture in comparison to data. This in turn improved the seasonal cycle of carbon uptake due to a more realistic limitation on photosynthesis during water stress. However, the peak fluxes are still too low, and phenology is poorly represented for desert shrubs and grasses. We provide suggestions on model developments needed to tackle these issues in the future. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFMGC51B..03D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFMGC51B..03D">The predicted CLARREO sampling error of the inter-annual SW variability</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Doelling, D. R.; Keyes, D. F.; Nguyen, C.; Macdonnell, D.; Young, D. F. 2009-12-01 The NRC Decadal Survey has called for SI traceability of long-term hyper-spectral flux measurements in order to monitor climate variability. This mission is called the Climate Absolute Radiance and Refractivity Observatory (CLARREO) and is currently defining its mission requirements. The requirements are focused on the ability to measure decadal change of key climate variables at very high accuracy. The accuracy goals are set using anticipated climate change magnitudes, but the accuracy achieved for any given climate variable must take into account the temporal and spatial sampling errors based on satellite orbits and calibration accuracy. The time period to detect a significant trend in the CLARREO record depends on the magnitude of the sampling calibration errors relative to the current inter-annual variability. The largest uncertainty in climate feedbacks remains the effect of changing clouds on planetary energy balance. Some regions on earth have strong diurnal cycles, such as maritime stratus and afternoon land convection; other regions have strong seasonal cycles, such as the monsoon. However, when monitoring inter-annual variability these cycles are only important if the strength of these cycles vary on decadal time scales. This study will attempt to determine the best satellite constellations to reduce sampling error and to compare the error with the current inter-annual variability signal to ensure the viability of the mission. The study will incorporate Clouds and the Earth's Radiant Energy System (CERES) (Monthly TOA/Surface Averages) SRBAVG product TOA LW and SW climate quality fluxes. The fluxes are derived by combining Terra (10:30 local equator crossing time) CERES fluxes with 3-hourly 5-geostationary satellite estimated broadband fluxes, which are normalized using the CERES fluxes, to complete the diurnal cycle. These fluxes were saved hourly during processing and considered the truth dataset. 90°, 83° and 74° inclination precessionary orbits as </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040070741&hterms=raman+KOH&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Draman%2BKOH','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040070741&hterms=raman+KOH&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Draman%2BKOH">Raman Spectral Observation of a "New Phase" Observed in Nickel Electrodes Cycled to Failure</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Loyselle, P. L.; Shan, X.; Cornilsen, B. C.; Reid, M. A. 1991-01-01 A "new phase" is reported in nickel electrodes from Ni/H boilerplate cells which were cycled to failure in electrolyte of variable kOH concentration. Raman spectra clearly show the presence of this phase, and these spectra have been used to quantify the amounts present in these electrodes (in the volume sampled by the laser beam) Raman spectroscopy has been found to be capable of differentiating the various phases which can be present in nickel .This differentiation is possible because of the structural variation observed for these phases. Ten of twelve electrodes examined contain at least some of this new phase. The presence of this "new phase" correlates with cell failure, and it is proposed that the presence of this phase may play a role in early electrode failure. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1468332','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1468332">Ultrastructural and histochemical study on the interrenal cells of the male stickleback (Gasterosteus aculeatus, Teleostea), in relation to the reproductive annual cycle</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> CIVININI, ANNALENA; PADULA, DANIELA; GALLO, VALENTINA P. 2001-01-01 The steroidogenic interrenal cells in the adrenal homologue of the male stickleback (Gasterosteus aculeatus) were studied in relation to the reproductive cycle by means of histological and ultrastructural observations, and using histochemical methods for the localisation of 3β-hydroxysteroid dehydrogenase (3βHSD) and 17β-hydroxysteroid dehydrogenase (17βHSD). To determine the various stages of the reproductive cycle, the testes were also examined by histological and histochemical methods (3βHSD). The results indicate that in this teleost the interrenal cells can undergo a cycle in which phases characterised by different cytological aspects are observed. During this cycle there is a renewal of organelles, in particular mitochondria and SER. Periodic degenerative processes are also found. Organelle cytology showed that the cell cycle has at least 3 different aspects during the year. An analogy with some cytological aspects of the adrenal zonation in mammals is possible. It is postulated that the interrenal gland activity could substitute or supplement androgen production by the testes. PMID:11554507 </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002CRPhy...3..595S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002CRPhy...3..595S">Observation des cycles enzymatiques des ADN topoisomérases par micromanipulation de molécules individuelles</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Strick, Terence R.; Charvin, Gilles; Dekker, Nynke H.; Allemand, Jean-François; Bensimon, David; Croquette, Vincent In this article, we describe single-molecule assays using magnetic traps and we applied these assays to topoisomerase enzymes which unwind and disentangle DNA molecules. First, the elasticity of single DNA molecule is characterized using the magnetic trap. We show that a twisting constraint may be easily applied and that its effect upon DNA may be measured accurately. Then we describe how the topoisomerase activity may be observed at the single-molecule level giving direct access to the important biological parameters of the enzyme such as velocity and processivity. Furthermore, individual cycles of unwinding can be observed in real time. This permits an accurate characterization of the enzyme's biochemical cycle. The data treatment required to identify and analyze individual topoisomerization cycles will be presented in detail. This analysis is applicable to a wide variety of molecular motors. To cite this article: T.R. Strick et al., C. R. Physique 3 (2002) 595-618. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150001415','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150001415">Tropical Cyclone Diurnal Cycle as Observed by TRMM</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Leppert, Kenneth D., II; Cecil, D. J. 2015-01-01 Using infrared satellite data, previous work has shown a consistent diurnal cycle in the pattern of cold cloud tops around mature tropical cyclones. In particular, an increase in the coverage by cold cloud tops often occurs in the inner core of the storm around the time of sunset and subsequently propagates outward to several hundred kilometers over the course of the following day. This consistent cycle may have important implications for structure and intensity changes of tropical cyclones and the forecasting of such changes. Because infrared satellite measurements are primarily sensitive to cloud top, the goal of this study is to use passive and active microwave measurements from the Tropical Rainfall Measurement Mission (TRMM) Microwave Imager (TMI) and Precipitation Radar (PR), respectively, to examine and better understand the tropical cyclone diurnal cycle throughout a larger depth of the storm's clouds. The National Hurricane Center's best track dataset was used to extract all PR and TMI pixels within 1000 km of each tropical cyclone that occurred in the Atlantic basin between 1998-2011. Then the data was composited according to radius (100-km bins from 0-1000 km) and local standard time (LST; 3-hr bins). Specifically, PR composites involved finding the percentage of pixels with reflectivity greater than or equal to 20 dBZ at various heights (i.e., 2-14 km in increments of 2 km) as a function of radius and time. The 37- and 85- GHz TMI channels are especially sensitive to scattering by precipitation-sized ice in the mid to upper portions of clouds. Hence, the percentage of 37- and 85-GHz polarization corrected temperatures less than various thresholds were calculated using data from all storms as a function of radius and time. For 37 GHz, thresholds of 260 K, 265 K, 270 K, and 275 K were used, and for 85 GHz, thresholds of 200-270 K in increments of 10 K were utilized. Note that convection forced by the interactions of a tropical cyclone with land (e.g., due </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.B21D1980D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.B21D1980D">GEO Carbon and GHG Initiative Task 3: Optimizing in-situ measurements of essential carbon cycle variables across observational networks</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Durden, D.; Muraoka, H.; Scholes, R. J.; Kim, D. G.; Loescher, H. W.; Bombelli, A. 2017-12-01 The development of an integrated global carbon cycle observation system to monitor changes in the carbon cycle, and ultimately the climate system, across the globe is of crucial importance in the 21stcentury. This system should be comprised of space and ground-based observations, in concert with modelling and analysis, to produce more robust budgets of carbon and other greenhouse gases (GHGs). A global initiative, the GEO Carbon and GHG Initiative, is working within the framework of Group on Earth Observations (GEO) to promote interoperability and provide integration across different parts of the system, particularly at domain interfaces. Thus, optimizing the efforts of existing networks and initiatives to reduce uncertainties in budgets of carbon and other GHGs. This is a very ambitious undertaking; therefore, the initiative is separated into tasks to provide actionable objectives. Task 3 focuses on the optimization of in-situ observational networks. The main objective of Task 3 is to develop and implement a procedure for enhancing and refining the observation system for identified essential carbon cycle variables (ECVs) that meets user-defined specifications at minimum total cost. This work focuses on the outline of the implementation plan, which includes a review of essential carbon cycle variables and observation technologies, mapping the ECVs performance, and analyzing gaps and opportunities in order to design an improved observing system. A description of the gap analysis of in-situ observations that will begin in the terrestrial domain to address issues of missing coordination and large spatial gaps, then extend to ocean and atmospheric observations in the future, will be outlined as the subsequent step to landscape mapping of existing observational networks. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.A53D0175T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.A53D0175T">Trends, interannual variability, and seasonal cycle of atmospheric methane over the western Pacific observed using voluntary observing ships</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Terao, Y.; Kim, H.; Mukai, H.; Nojiri, Y.; Machida, T.; Tohjima, Y.; Saeki, T.; Maksyutov, S. 2012-12-01 We present an analysis of trends, interannual variability (IAV), and seasonal cycle of atmospheric methane (CH4) over the western Pacific between 55N and 35S from 1994 to 2011. Observations were made by the National Institute for Environmental Studies (NIES), Center for Global Environmental Research (CGER), using voluntary observation ships sailing between Japan and Australia/New Zealand and between Japan and North America, sampling background maritime air quasi-monthly with high resolution in latitude. We found remarkable phenomena in IAV of CH4 in the northern tropics over the western Pacific: 1) the high growth rate of 20 ppb/yr in mid-1997 ahead of the global increase in 1998, 2) the suppression of CH4 growth in 2007, 3) significantly smaller amplitude of seasonal cycle in 1999-2000 and in 2008. Results from the simulation and meteorological analysis indicated that the IAV in atmospheric circulation associated with the El Nino and La Nina significantly contributed to these events. Our observations were made at sites located relatively close to the large CH4 sources of East and Southeast Asia, which resulted in the high sensitivity of measured CH4 mixing ratios in the northern tropics to changes in atmospheric transport and emissions from East and Southeast Asia. We will show the results from inverse analysis using our ship measurements as well as other global dataset. The CH4 data set we presented here would be valuable in accurately and quantitatively estimating the global CH4 budget. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.H21G1495J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.H21G1495J">Responses of the terrestrial carbon cycle to drought: modeling sensitivities of the interactive nitrogen and dynamic vegetation</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Jia, B.; Wang, Y.; Xie, Z. 2016-12-01 Drought can trigger both immediate and time-lagged responses of terrestrial ecosystems and even cause sizeable positive feedbacks to climate warming. In this study, the influences of interactive nitrogen (N) and dynamic vegetation (DV) on the response of the carbon cycle in terrestrial ecosystems of China to drought were investigated using the Community Land Model version 4.5 (CLM4.5). Model simulations from three configurations of CLM4.5 (C, carbon cycle only; CN, dynamic carbon and nitrogen cycle; CNDV, dynamic carbon and nitrogen cycle as well as dynamic vegetation) between 1961 and 2010 showed that the incorporation of a prognostic N cycle and DV into CLM4.5 reduce the predicted annual means and inter-annual variability of predicted gross primary production (GPP) and net ecosystem production (NEP), except for a slight increase in NEP for CNDV compared to CN. These model improvements resulted in better agreement with observations (7.0 PgC yr-1) of annual GPP over the terrestrial ecosystems in China for CLM45-CN (7.5 PgC yr-1) and CLM45-CNDV (7.3 PgC yr-1) than for CLM45-C (10.9 PgC yr-1). Compared to the CLM45-C, the carbon-nitrogen coupling strengthened the predicted response of GPP to drought, resulting in a higher correlation with the standardized precipitation index (SPI; rC = 0.62, rCN = 0.67), but led to a weaker sensitivity of NEP to SPI (rC = 0.51, rCN = 0.45). The CLM45-CNDV had the longest lagged responses of GPP to drought among the three configurations. These results enhance our understanding of the response of the terrestrial carbon cycle to drought. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23613585','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23613585">Assessment of radiative feedback in climate models using satellite observations of annual flux variation.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Tsushima, Yoko; Manabe, Syukuro 2013-05-07 In the climate system, two types of radiative feedback are in operation. The feedback of the first kind involves the radiative damping of the vertically uniform temperature perturbation of the troposphere and Earth's surface that approximately follows the Stefan-Boltzmann law of blackbody radiation. The second kind involves the change in the vertical lapse rate of temperature, water vapor, and clouds in the troposphere and albedo of the Earth's surface. Using satellite observations of the annual variation of the outgoing flux of longwave radiation and that of reflected solar radiation at the top of the atmosphere, this study estimates the so-called "gain factor," which characterizes the strength of radiative feedback of the second kind that operates on the annually varying, global-scale perturbation of temperature at the Earth's surface. The gain factor is computed not only for all sky but also for clear sky. The gain factor of so-called "cloud radiative forcing" is then computed as the difference between the two. The gain factors thus obtained are compared with those obtained from 35 models that were used for the fourth and fifth Intergovernmental Panel on Climate Change assessment. Here, we show that the gain factors obtained from satellite observations of cloud radiative forcing are effective for identifying systematic biases of the feedback processes that control the sensitivity of simulated climate, providing useful information for validating and improving a climate model. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUFMPP11A1426A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUFMPP11A1426A">Annual Proxy Records from Tropical Cloud Forest Trees in the Monteverde Cloud Forest, Costa Rica</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Anchukaitis, K. J.; Evans, M. N.; Wheelwright, N. T.; Schrag, D. P. 2005-12-01 The extinction of the Golden Toad (Bufo periglenes) from Costa Rica's Monteverde Cloud Forest prompted research into the causes of ecological change in the montane forests of Costa Rica. Subsequent analysis of meteorological data has suggested that warmer global surface and tropical Pacific sea surface temperatures contribute to an observed decrease in cloud cover at Monteverde. However, while recent studies may have concluded that climate change is already having an effect on cloud forest environments in Costa Rica, without the context provided by long-term climate records, it is difficult to confidently conclude that the observed ecological changes are the result of anthropogenic climate forcing, land clearance in the lowland rainforest, or natural variability in tropical climate. To address this, we develop high-resolution proxy paleoclimate records from trees without annual rings in the Monteverde Cloud Forest in Costa Rica. Calibration of an age model in these trees is a fundamental prerequisite for proxy paleoclimate reconstructions. Our approach exploits the isotopic seasonality in the δ18O of water sources (fog versus rainfall) used by trees over the course of a single year. Ocotea tenera individuals of known age and measured annual growth increments were sampled in long-term monitored plantation sites in order to test this proposed age model. High-resolution (200μm increments) stable isotope measurements on cellulose reveal distinct, coherent δ18O cycles of 6 to 10‰. The calculated growth rates derived from the isotope timeseries match those observed from basal growth increment measurements. Spatial fidelity in the age model and climate signal is examined by using multiple cores from multiple trees and multiple sites. These data support our hypothesis that annual isotope cycles in these trees can be used to provide chronological control in the absence of rings. The ability of trees to record interannual climate variability in local hydrometeorology </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.A11E0128C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.A11E0128C">The HIAPER Pole-to-Pole Observations (HIPPO) Public Data Archive at CDIAC: Carbon Cycle and Greenhouse Gas Data</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Christensen, S. W.; Hook, L. A. 2011-12-01 The HIAPER Pole-to-Pole Observations (HIPPO) project is investigating the carbon cycle and greenhouse gases throughout various altitudes in the atmosphere over the Pacific Basin through the annual cycle (Wofsy and the HIPPO Science Team 2011, this session). Aircraft-based data collection occurred during 2009-2011. Data analyses, comparisons, and integration are ongoing. A permanent public archive of HIPPO data has been established at the U. S. DOE Carbon Dioxide Information Analysis Center (CDIAC). Datasets are provided primarily by the Lead Principal Investigator (PI), who draws on a comprehensive set of aircraft navigation information, meteorological measurements, and research instrument and sampling system results from multiple co-investigators to compile integrated and generate value-added products. A website/ftp site has been developed for HIPPO data and metadata (http://hippo.ornl.gov), in coordination with the UCAR website that presents field catalogs and other detailed information about HIPPO missions (http://www.eol.ucar.edu/projects/hippo/dm/). A data policy was adopted that balances the needs of the project investigators with the interests of the scientific user community. A data dictionary was developed to capture the basic characteristics of the hundreds of measurements. Instrument descriptions were compiled. A user's guide is presented for each dataset that also contains data file information enabling users to know when data have been updated. Data are received and provided as space-delimited ASCII files. Metadata records are compiled into a searchable CDIAC index and will be submitted to climate change research data clearinghouses. Each dataset is given a persistent identifier (DOI) to facilitate attribution. We expect that data will continue to be added to the archive for the next year or more. In the future we anticipate creating a database for HIPPO data, with a web interface to facilitate searching and customized data extraction. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.1647C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.1647C">A Climatology of dust emission in northern Africa using surface observations from 1984-2012</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Cowie, Sophie; Knippertz, Peter; Marsham, John 2014-05-01 The huge quantity of mineral dust emitted annually from northern Africa makes this area crucial to the global dust cycle. Once in the atmosphere, dust aerosols have a significant impact on the global radiation budget, clouds, the carbon cycle and can even act as a fertilizer to rain forests in South America. Current model estimates of dust production from northern Africa are uncertain. At the heart of this problem is insufficient understanding of key dust emitting processes such as haboobs (cold pools generated through evaporation of convective precipitation), low-level jets (LLJs) and dry convection (dust devils and dust plumes). Scarce observations in this region, in particular in the Sahara, make model evaluation difficult. This work uses long-term surface observations from 70 stations situated in the Sahara and Sahel to explore the diurnal, seasonal and geographical variations in dust emission events and thresholds. Quality flags are applied to each station to indicate a day-time bias or gaps in the time period 1984-2012. The frequency of dust emission (FDE) is calculated using the present weather codes (WW) of SYNOP reports, where WW = 07,08,09,30-35 and 98. Thresholds are investigated by estimating the wind speeds for which there is a 25%, 50% and 75% probability of dust emission. The 50% threshold is used to calculate strong wind frequency (SWF) and the diagnostic parameter dust uplift potential (DUP); a thresholded cubic function of wind-speed which quantifies the dust generating power of winds. Stations are grouped into 6 areas (North Algeria, Central Sahara, Egypt, West Sahel, Central Sahel and Sudan) for more in-depth analysis of these parameters. Spatially, thresholds are highest in northern Algeria and lowest in the Sahel around the latitude band 16N-21N. Annual mean FDE is anti-correlated with the threshold, showing the importance of spatial variations in thresholds for mean dust emission. The annual cycles of FDE and SWF for the 6 grouped areas are </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70043697','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70043697">Annual accumulation over the Greenland ice sheet interpolated from historical and newly compiled observation data</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Shen, Dayong; Liu, Yuling; Huang, Shengli 2012-01-01 The estimation of ice/snow accumulation is of great significance in quantifying the mass balance of ice sheets and variation in water resources. Improving the accuracy and reducing uncertainty has been a challenge for the estimation of annual accumulation over the Greenland ice sheet. In this study, we kriged and analyzed the spatial pattern of accumulation based on an observation data series including 315 points used in a recent research, plus 101 ice cores and snow pits and newly compiled 23 coastal weather station data. The estimated annual accumulation over the Greenland ice sheet is 31.2 g cm−2 yr−1, with a standard error of 0.9 g cm−2 yr−1. The main differences between the improved map developed in this study and the recently published accumulation maps are in the coastal areas, especially southeast and southwest regions. The analysis of accumulations versus elevation reveals the distribution patterns of accumulation over the Greenland ice sheet. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5530641','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5530641">Annual mass drownings of the Serengeti wildebeest migration influence nutrient cycling and storage in the Mara River</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> Rosi, Emma J.; Post, David M. 2017-01-01 The annual migration of ∼1.2 million wildebeest (Connochaetes taurinus) through the Serengeti Mara Ecosystem is the largest remaining overland migration in the world. One of the most iconic portions of their migration is crossing of the Mara River, during which thousands drown annually. These mass drownings have been noted, but their frequency, size, and impact on aquatic ecosystems have not been quantified. Here, we estimate the frequency and size of mass drownings in the Mara River and model the fate of carcass nutrients through the river ecosystem. Mass drownings (>100 individuals) occurred in at least 13 of the past 15 y; on average, 6,250 carcasses and 1,100 tons of biomass enter the river each year. Half of a wildebeest carcass dry mass is bone, which takes 7 y to decompose, thus acting as a long-term source of nutrients to the Mara River. Carcass soft tissue decomposes in 2–10 wk, and these nutrients are mineralized by consumers, assimilated by biofilms, transported downstream, or moved back into the terrestrial ecosystem by scavengers. These inputs comprise 34–50% of the assimilated diet of fish when carcasses are present and 7–24% via biofilm on bones after soft tissue decomposition. Our results show a terrestrial animal migration can have large impacts on a river ecosystem, which may influence nutrient cycling and river food webs at decadal time scales. Similar mass drownings may have played an important role in rivers throughout the world when large migratory herds were more common features of the landscape. PMID:28630330 </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5779857','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5779857">Tropical Cyclone Diurnal Cycle as Observed by TRMM</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> Leppert, Kenneth D.; Cecil, Daniel J. 2018-01-01 Previous work has indicated a clear, consistent diurnal cycle in rainfall and cold cloudiness coverage around tropical cyclones. This cycle may have important implications for structure and intensity changes of these storms and the forecasting of such changes. The goal of this paper is to use passive and active microwave measurements from the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) and Precipitation Radar (PR), respectively, to better understand the tropical cyclone diurnal cycle throughout a deep layer of a tropical cyclone’s clouds. The composite coverage by PR reflectivity ≥20 dBZ at various heights as a function of local standard time (LST) and radius suggests the presence of a diurnal signal for radii <500 km through a deep layer (2–10 km height) of the troposphere using 1998–2011 Atlantic tropical cyclones of at least tropical storm strength. The area covered by reflectivity ≥20 dBZ at radii 100–500 km peaks in the morning (0130–1030 LST) and reaches a minimum 1030–1930 LST. Radii between 300–500 km tend to reach a minimum in coverage closer to 1200 LST before reaching another peak at 2100 LST. The inner core (0–100 km) appears to be associated with a single-peaked diurnal cycle only at upper levels (8–10 km) with a maximum at 2230−0430 LST. The TMI rainfall composites suggest a clear diurnal cycle at all radii between 200 and 1000 km with peak rainfall coverage and rain rate occurring in the morning (0130−0730 LST). PMID:29371745 </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016cosp...41E1762S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016cosp...41E1762S">Geomagnetic activity during 10 - 11 solar cycles that has been observed by old Russian observatories.</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Seredyn, Tomasz; Wysokinski, Arkadiusz; Kobylinski, Zbigniew; Bialy, Jerzy 2016-07-01 A good knowledge of solar-terrestrial relations during past solar activity cycles could give the appropriate tools for a correct space weather forecast. The paper focuses on the analysis of the historical collections of the ground based magnetic observations and their operational indices from the period of two sunspot solar cycles 10 - 11, period 1856 - 1878 (Bartels rotations 324 - 635). We use hourly observations of H and D geomagnetic field components registered at Russian stations: St. Petersburg - Pavlovsk, Barnaul, Ekaterinburg, Nertshinsk, Sitka, and compare them to the data obtained from the Helsinki observatory. We compare directly these records and also calculated from the data of the every above mentioned station IHV indices introduced by Svalgaard (2003), which have been used for further comparisons in epochs of assumed different polarity of the heliospheric magnetic field. We used also local index C9 derived by Zosimovich (1981) from St. Petersburg - Pavlovsk data. Solar activity is represented by sunspot numbers. The correlative and continuous wavelet analyses are applied for estimation of the correctness of records from different magnetic stations. We have specially regard to magnetic storms in the investigated period and the special Carrington event of 1-2 Sep 1859. Generally studied magnetic time series correctly show variability of the geomagnetic activity. Geomagnetic activity presents some delay in relation to solar one as it is seen especially during descending and minimum phase of the even 11-year cycle. This pattern looks similarly in the case of 16 - 17 solar cycles. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004GeoRL..31.9801F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004GeoRL..31.9801F">Sunspot cycle-dependent changes in the distribution of GSE latitudinal angles of IMF observed near 1 AU</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Felix Pereira, B.; Girish, T. E. 2004-05-01 The solar cycle variations in the characteristics of the GSE latitudinal angles of the Interplanetary Magnetic Field ($\\theta$GSE) observed near 1 AU have been studied for the period 1967-2000. It is observed that the statistical parameters mean, standard deviation, skewness and kurtosis vary with sunspot cycle. The $\\theta$GSE distribution resembles the Gaussian curve during sunspot maximum and is clearly non-Gaussian during sunspot minimum. The width of the $\\theta$GSE distribution is found to increase with sunspot activity, which is likely to depend on the occurrence of solar transients. Solar cycle variations in skewness are ordered by the solar polar magnetic field changes. This can be explained in terms of the dependence of the dominant polarity of the north-south component of IMF in the GSE system near 1 AU on the IMF sector polarity and the structure of the heliospheric current sheet. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JGRE..123..508S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JGRE..123..508S">Modeling the Hydrological Cycle in the Atmosphere of Mars: Influence of a Bimodal Size Distribution of Aerosol Nucleation Particles</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Shaposhnikov, Dmitry S.; Rodin, Alexander V.; Medvedev, Alexander S.; Fedorova, Anna A.; Kuroda, Takeshi; Hartogh, Paul 2018-02-01 We present a new implementation of the hydrological cycle scheme into a general circulation model of the Martian atmosphere. The model includes a semi-Lagrangian transport scheme for water vapor and ice and accounts for microphysics of phase transitions between them. The hydrological scheme includes processes of saturation, nucleation, particle growth, sublimation, and sedimentation under the assumption of a variable size distribution. The scheme has been implemented into the Max Planck Institute Martian general circulation model and tested assuming monomodal and bimodal lognormal distributions of ice condensation nuclei. We present a comparison of the simulated annual variations, horizontal and vertical distributions of water vapor, and ice clouds with the available observations from instruments on board Mars orbiters. The accounting for bimodality of aerosol particle distribution improves the simulations of the annual hydrological cycle, including predicted ice clouds mass, opacity, number density, and particle radii. The increased number density and lower nucleation rates bring the simulated cloud opacities closer to observations. Simulations show a weak effect of the excess of small aerosol particles on the simulated water vapor distributions. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1320377','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1320377">2016 Annual Technology Baseline (ATB)</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Cole, Wesley; Kurup, Parthiv; Hand, Maureen Consistent cost and performance data for various electricity generation technologies can be difficult to find and may change frequently for certain technologies. With the Annual Technology Baseline (ATB), National Renewable Energy Laboratory provides an organized and centralized dataset that was reviewed by internal and external experts. It uses the best information from the Department of Energy laboratory's renewable energy analysts and Energy Information Administration information for conventional technologies. The ATB will be updated annually in order to provide an up-to-date repository of current and future cost and performance data. Going forward, we plan to revise and refine the values usingmore » best available information. The ATB includes both a presentation with notes (PDF) and an associated Excel Workbook. The ATB includes the following electricity generation technologies: land-based wind; offshore wind; utility-scale solar PV; concentrating solar power; geothermal power; hydropower plants (upgrades to existing facilities, powering non-powered dams, and new stream-reach development); conventional coal; coal with carbon capture and sequestration; integrated gasification combined cycle coal; natural gas combustion turbines; natural gas combined cycle; conventional biopower. Nuclear laboratory's renewable energy analysts and Energy Information Administration information for conventional technologies. The ATB will be updated annually in order to provide an up-to-date repository of current and future cost and performance data. Going forward, we plan to revise and refine the values using best available information.« less </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active">12</li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active">13</li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMGC24G..06S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMGC24G..06S">A direct estimate of evapotranspiration over the Amazon basin and implications for our understanding of carbon and water cycling</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Swann, A. L. S.; Koven, C.; Lombardozzi, D.; Bonan, G. B. 2017-12-01 Evapotranspiration (ET) is a critical term in the surface energy budget as well as the water cycle. There are few direct measurements of ET, and thus the magnitude and variability is poorly constrained at large spatial scales. Estimates of the annual cycle of ET over the Amazon are critical because they influence predictions of the seasonal cycle of carbon fluxes, as well as atmospheric dynamics and circulation. We estimate ET for the Amazon basin using a water budget approach, by differencing rainfall, discharge, and time-varying storage from the Gravity Recovery and Climate Experiment. We find that the climatological annual cycle of ET over the Amazon basin upstream of Óbidos shows suppression of ET during the wet season, and higher ET during the dry season, consistent with flux tower based observations in seasonally dry forests. We also find a statistically significant decrease in ET over the time period 2002-2015 of -1.46 mm/yr. Our direct estimate of the seasonal cycle of ET is largely consistent with previous indirect estimates, including energy budget based approaches, an up-scaled station based estimate, and land surface model estimates, but suggests that suppression of ET during the wet season is underestimated by existing products. We further quantify possible contributors to the phasing of the seasonal cycle and downward time trend using land surface models. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11543132','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11543132">Solar cycle variations of MIR radiation environment as observed by the LIULIN dosimeter.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Dachev TsP; Tomov, B T; Matviichuk YuN; Koleva, R T; Semkova, J V; Petrov, V M; Benghin, V V; Ivanov YuV; Shurshakov, V A; Lemaire, J F 1999-06-01 Measurements on board the MIR space station by the Bulgarian-Russian dosimeter LIULIN have been used to study the solar cycle variations of the radiation environment. The fixed locations of the instrument in the MIR manned compartment behind 6-15 g/cm2 of shielding have given homogeneous series of particle fluxes and doses measurements to be collected during the declining phase of 22nd solar cycle between September 1989 and April 1994. During the declining phase of 22nd solar cycle the GCR (Galactic Cosmic Rays) flux observed at L>4 (where L is the McIlwain parameter) has enhanced from 0.6-0.7 cm-2 s-1 up to 1.4-1.6 cm-2 s-1. The long-term observations of the trapped radiation can be summarized as follows: the main maximum of the flux and dose rate is located at the southeast side of the geomagnetic field minimum of South Atlantic Anomaly (SAA) at L=1.3-1.4. Protons depositing few (nGy cm2)/particle in the detector predominantly populate this region. At practically the same spatial location and for similar conditions the dose rate rises up from 480 to 1470 microGy/h dose in silicon in the 1990-1994 time interval, during the declining phase of the solar cycle. On the other hand the flux rises from 35 up to 115 cm-2 s-1 for the same period of time. A power law dependence was extracted which predicts that when the total neutral density at the altitude of the station decreases from 8x10(-15) to 6x10(-16) g/cm3 the dose increase from about 200 microGy/h up to 1200 microGy/h. At the same time the flux increase from about 30 cm-2 s-1 up to 120 cm-2 s-1. The AP8 model predictions give only 5.8% increase of the flux for the same conditions. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004IRH....89..165D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004IRH....89..165D">Life Cycle, Feeding and Production of Isoptena serricornis(Pictet, 1841)</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Derka, Tomá; Tierno de Figueroa, José Manuel; Krno, Il'ja 2004-05-01 Some aspects of the biology and ecology (life cycle, feeding and production) of a population of Isoptena serricornis in the Rudava River (Slovakia) are studied, reported and discussed. The life cycle is annual, with slow growth in autumn-winter and fast growth in late summer and spring. The growth decreased two weeks before the Fall Equinox and increased two weeks after the Spring Equinox. The flight period spans from the end of May to the beginning of July. The presence of large sand particles in the gut of all studied nymphs is of note, and indicates that I. serricornis acts as a deposit-collector species. Nymphal food is principally composed of detritus, unicellular organisms and, in nymphs of intermediate or large size, Chironomidae larvae. Adult food is composed fundamentally of different types of pollen grains. Males usually have lower food content than females. Annual production of this species (694-750 mg Â· m-2) is very high in relation to other previously studied Chloroperlidae. This is probably largely responsible for I. serricornis being one of the most abundant components of the macroinvertebrate community in its habitat in the Rudava River. A negative correlation between production and temperature was observed. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17555828','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17555828">The gamma cycle.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Fries, Pascal; Nikolić, Danko; Singer, Wolf 2007-07-01 Activated neuronal groups typically engage in rhythmic synchronization in the gamma-frequency range (30-100 Hz). Experimental and modeling studies demonstrate that each gamma cycle is framed by synchronized spiking of inhibitory interneurons. Here, we review evidence suggesting that the resulting rhythmic network inhibition interacts with excitatory input to pyramidal cells such that the more excited cells fire earlier in the gamma cycle. Thus, the amplitude of excitatory drive is recoded into phase values of discharges relative to the gamma cycle. This recoding enables transmission and read out of amplitude information within a single gamma cycle without requiring rate integration. Furthermore, variation of phase relations can be exploited to facilitate or inhibit exchange of information between oscillating cell assemblies. The gamma cycle could thus serve as a fundamental computational mechanism for the implementation of a temporal coding scheme that enables fast processing and flexible routing of activity, supporting fast selection and binding of distributed responses. This review is part of the INMED/TINS special issue Physiogenic and pathogenic oscillations: the beauty and the beast, based on presentations at the annual INMED/TINS symposium (http://inmednet.com). </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27080464','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27080464">Sex Difference in Draft-Legal Ultra-Distance Events - A Comparison between Ultra-Swimming and Ultra-Cycling.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Salihu, Lejla; Rüst, Christoph Alexander; Rosemann, Thomas; Knechtle, Beat 2016-04-30 Recent studies reported that the sex difference in performance in ultra-endurance sports such as swimming and cycling changed over the years. However, the aspect of drafting in draft-legal ultra-endurance races has not yet been investigated. This study investigates the sex difference in ultra-swimming and ultra-cycling draft-legal races where drafting - swimming or cycling behind other participants to save energy and have more power at the end of the race to overtake them, is allowed. The change in performance of the annual best and the annual three best in an ultra-endurance swimming race (16-km 'Faros Swim Marathon') over 38 years and in a 24-h ultra-cycling race ('World Cycling Race') over 13 years were compared and analysed with respect to sex difference. Furthermore, performances of the fastest female and male finishers ever were compared. In the swimming event, the sex difference of the annual best male and female decreased non-significantly (P = 0.262) from 5.3% (1976) to 1.0% (2013). The sex gap of speed in the annual three fastest swimmers decreased significantly (P = 0.043) from 5.9 ± 1.6% (1979) to 4.7 ± 3.1% (2013). In the cycling event, the difference in cycling speed between the annual best male and female decreased significantly (P = 0.026) from 33.31% (1999) to 10.89% (2011). The sex gap of speed in the annual three fastest decreased significantly (P = 0.001) from 32.9 ± 0.6% (1999) to 16.4 ± 5.9% (2011). The fastest male swimmer ever (swimming speed 5.3 km/h, race time: 03:01:55 h:min:s) was 1.5% faster than the fastest female swimmer (swimming speed 5.2 km/h, race time: 03:04:09 h:min:s). The three fastest male swimmers ever (mean 5.27 ± 0.13 km/h) were 4.4% faster than the three fastest female swimmers (mean 5.05 ± 0.20 km/h) (P < 0.05). In the cycling event, the best male ever (cycling speed 45.8 km/h) was 26.4% faster than the best female (cycling speed 36.1 km/h). The three fastest male cyclists ever (45.9 km/h) (mean 45.85 ± 0.05 km </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20060050130','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20060050130">Examination of the Armagh Observatory Annual Mean Temperature Record, 1844-2004</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Wilson, Robert M.; Hathaway, David H. 2006-01-01 The long-term annual mean temperature record (1844-2004) of the Armagh Observatory (Armagh, Northern Ireland, United Kingdom) is examined for evidence of systematic variation, in particular, as related to solar/geomagnetic forcing and secular variation. Indeed, both are apparent in the temperature record. Moving averages for 10 years of temperature are found to highly correlate against both 10-year moving averages of the aa-geomagnetic index and sunspot number, having correlation coefficients of approx. 0.7, inferring that nearly half the variance in the 10-year moving average of temperature can be explained by solar/geomagnetic forcing. The residuals appear episodic in nature, with cooling seen in the 1880s and again near 1980. Seven of the last 10 years of the temperature record has exceeded 10 C, unprecedented in the overall record. Variation of sunspot cyclic averages and 2-cycle moving averages of temperature strongly associate with similar averages for the solar/geomagnetic cycle, with the residuals displaying an apparent 9-cycle variation and a steep rise in temperature associated with cycle 23. Hale cycle averages of temperature for even-odd pairs of sunspot cycles correlate against similar averages for the solar/geomagnetic cycle and, especially, against the length of the Hale cycle. Indications are that annual mean temperature will likely exceed 10 C over the next decade. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950033056&hterms=physical+activity&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dphysical%2Bactivity','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950033056&hterms=physical+activity&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dphysical%2Bactivity">Observations of hysteresis in solar cycle variations among seven solar activity indicators</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Bachmann, Kurt T.; White, Oran R. 1994-01-01 We show that smoothed time series of 7 indices of solar activity exhibit significant solar cycle dependent differences in their relative variations during the past 20 years. In some cases these observed hysteresis patterns start to repeat over more than one solar cycle, giving evidence that this is a normal feature of solar variability. Among the indices we study, we find that the hysteresis effects are approximately simple phase shifts, and we quantify these phase shifts in terms of lag times behind the leading index, the International Sunspot Number. Our measured lag times range from less than one month to greater than four months and can be much larger than lag times estimated from short-term variations of these same activity indices during the emergence and decay of major active regions. We argue that hysteresis represents a real delay in the onset and decline of solar activity and is an important clue in the search for physical processes responsible for changing solar emission at various wavelengths. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920019796&hterms=1956&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3D%253F%253F%253F%253F%253F%253F%253F%253F%253F%253F%2B%253F.%2B%253F.%2B%253F%253F%253F%253F%253F%253F%253F%253F%2B%253F%253F%253F%253F%253F%253F%253F%253F%253F%253F.%2B%253F.%2B1956','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920019796&hterms=1956&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3D%253F%253F%253F%253F%253F%253F%253F%253F%253F%253F%2B%253F.%2B%253F.%2B%253F%253F%253F%253F%253F%253F%253F%253F%2B%253F%253F%253F%253F%253F%253F%253F%253F%253F%253F.%2B%253F.%2B1956">Observed changes in limb clouds immediately prior to the onset of planet-encircling dust storms</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Martin, L. J.; James, P. B.; Zurek, R. W. 1992-01-01 Of the several size and nomenclature groupings of Martian dust storms, it is the plane-encircling or truly runaway dust storms that are of most concern to both the theoreticians and mission planners. Once believed to be regularly seasonal, it is now known that they are not annual occurrences and that the few we know about occurred within at least one-third of Mars' seasonal cycle. We cannot confirm that any were observed before 1956, and not one has been observed since 1982 (the classification of that event as 'encircling' is an interpretation of observation from a single point on the planet's surface). If these storms occur in cycles, we do not know the lengths or causes of the cycles. Regional and local dust storms occur more frequently and throughout the Martian year, but the underlying question is how do some become runaways, encircling the planet, while the others die out, usually within a few days. An investigation of this topic is presented. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/982165-effect-anthropogenic-emissions-corrections-seasonal-cycle-atmospheric-co2','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/982165-effect-anthropogenic-emissions-corrections-seasonal-cycle-atmospheric-co2">The effect of anthropogenic emissions corrections on the seasonal cycle of atmospheric CO2</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Hoffman, Forrest M; Erickson III, David J; Blasing, T J A previous study (Erickson et al. 2008) approximated the monthly global emission estimates of anthropogenic CO{sub 2} by applying a 2-harmonic Fourier expansion with coefficients as a function of latitude to annual CO{sub 2} flux estimates derived from United States data (Blasing et al. 2005) that were extrapolated globally. These monthly anthropogenic CO{sub 2} flux estimates were used to model atmospheric concentrations using the NASA GEOS-4 data assimilation system. Local variability in the amplitude of the simulated CO{sub 2} seasonal cycle were found to be on the order of 2-6 ppmv. Here we used the same Fourier expansion to seasonallymore » adjust the global annual fossil fuel CO{sub 2} emissions from the SRES A2 scenario. For a total of four simulations, both the annual and seasonalized fluxes were advected in two configurations of the NCAR Community Atmosphere Model (CAM) used in the Carbon-Land Model Intercomparison Project (C-LAMP). One configuration used the NCAR Community Land Model (CLM) coupled with the CASA (carbon only) biogeochemistry model and the other used CLM coupled with the CN (coupled carbon and nitrogen cycles) biogeochemistry model. All four simulations were forced with observed sea surface temperatures and sea ice concentrations from the Hadley Centre and a prescribed transient atmospheric CO{sub 2} concentration for the radiation and land forcing over the 20th century. The model results exhibit differences in the seasonal cycle of CO{sub 2} between the seasonally corrected and uncorrected simulations. Moreover, because of differing energy and water feedbacks between the atmosphere model and the two land biogeochemistry models, features of the CO{sub 2} seasonal cycle were different between these two model configurations. This study reinforces previous findings that suggest that regional near-surface atmospheric CO{sub 2} concentrations depend strongly on the natural sources and sinks of CO{sub 2}, but also on the strength of local </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMPP51C1078B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMPP51C1078B">An optimized chronology for a stalagmite using seasonal trace element cycles from Shihua Cave, Beijing, North China</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Ban, F.; Baker, A.; Marjo, C.; Duan, W.; Li, X.; Coleborn, K.; Akter, R.; Nagra, G. 2017-12-01 Stalagmites play an increasingly important role in the paleoclimatic reconstruction from seasonal to orbital timescales. One of the important reasons is that 230Th-dating can provide an absolute age enabling more accurate knowledge of the stalagmite growth. Additionally, annual trace element and optical layers can provide complementary method for determining a precise age and seasonal resolution. The trace elements of a stalagmite (XMG) in Beijing Shihua Cave, which is located in the East Asian monsoon region, were analyzed by laser ablation ICP-MS and compared with stalagmite laminae. The results show that: (1) the polished section of the topmost 4 mm of stalagmite XMG has obvious bi-optical layers (fluorescence and visible light) under a conventional transmission microscope. In the rest of the sample laminae are not observed using this method. (2) The variations of P/Ca, Sr/Ca, Ba/Ca, U/Ca and Mg/Ca show seasonal cycles throughout the sample. Sr/Ca is inversely correlated to P/Ca, and its peaks correspond with the (non-fluorescing) white layers, which deposit in late winter and spring when the climate is dry. The peaks of P/Ca match closely with the (fluorescing) opaque layers, because P is a soil-derived element which increases in the high rainfall monsoon period. (3) The PCA of the five trace elements showed that the cycles of PC1 could represent the annual cycle. This stalagmite was deposited over 148 ± 4 years through peak counting and the cycles of PC1 correspond well with the annual layers. Trace element cyclicity as shown by PC1 can increase the accuracy of stalagmite dating, especially in the absence of obvious laminae. The trace elements can be used as the marker of seasonal changes in a strongly contrasting wet-dry monsoon climate regime. Keywords: high-precision dating; LA-ICP-MS; stalagmite; trace elements; seasonal cycles; Shihua Cave </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002EGSGA..27.4964P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002EGSGA..27.4964P">An Annual Cycle Of Currents Around Tsushima Island And Resulting Inflow Conditions In The Sea Of Japan</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Perkins, H.; Teague, W. J.; Chang, K.-I.; Suk, M.-S.; Lee, J.-C.; Book, J. W.; Jacobs, G. A. A ten-month long time series of current measurements has been made on two sections across Korea/Tsushima Strait, thus revealing most of an annual cycle of the Tsushima Current that flows into the Japan/East Sea. One section is southwest, the other north- east, of Tsushima Island, giving respectively conditions upstream and downstream of the Island. Along the bathymetric slope upstream of the Island, the current consists of a single, broad stream concentrated in mid-channel. Downstream, this single core is found to have separated into two branches, one on each of the Strait. Between these two near-coastal streams, in the apparent wake of the Island, currents are variable and lack a well-defined mean. This separation persisted during all seasons despite vari- ation in total transport by a factor of two, from 3.5 Sv in October 1999 to 1.7 Sv in January 2000, and despite changes from maximum to minimum stratification. Both branches of the divided current were stronger during high transport and weaker during low transport, but since each branch was measured by only one or two moorings, trans- port estimates for the separate branches are not available. Strongest currents occurred at the surface close to the Korean coast near Ulsan in early fall with low-pass surface currents reaching 90 cm/s during October and November. Farther downstream, outside the measurement area, the two branches define the inflow to the Japan/East Sea. The branch along the Japanese coast remains close to the coast. It undergoes strong annual variability but is steady on shorter time scales. The Korean branch of the current also undergoes strong annual changes but experiences very strong variability, especially in winter. This branch is thought to switch between two paths. The first parallels the Ko- rean coast; the second follows bathymetric contours that lead it back to the Japanese coast. A mechanism for switching between these paths is provided by vorticity asso- ciated with bottom intrusions </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSAH21A..03S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSAH21A..03S">Seasonality of biological and physical controls on surface ocean CO2 from hourly observations at the Southern Ocean Time Series site south of Australia.</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Shadwick, E. H.; Trull, T. W.; Tilbrook, B. D.; Sutton, A.; Sabine, C. L. 2016-02-01 The Subantarctic Zone (SAZ), which covers the northern half of the Southern Ocean between the Subtropical and Subantarctic Fronts is important for air-sea CO2 exchange, ventilation of the lower thermocline, and nutrient supply for global ocean productivity. The first high-resolution autonomous observations of mixed layer CO2 partial pressure (pCO2) and hydrographic properties in the SAZ covering a full annual cycle will be presented. The annual cycle of pCO2 is decomposed into physical and biological drivers: after the summer biological pCO2 depletion (driven by an annual net community production of 2.45±1.47 mol C m-2 yr-1), the return to near atmospheric equilibrium proceeds slowly, driven by entrainment in early autumn when mixed layers deepen from <100 to 200m, but only achieving full equilibration in late winter/early spring as respiration completes the annual cycle. The shutdown of winter convection and associated mixed layer shoaling proceeds intermittently, appearing to frustrate the initiation of production. Horizontal processes, identified from salinity anomalies, are associated with biological pCO2 signatures, but with differing impacts in winter (when they reflect far-field variations in dissolved inorganic carbon and/or biomass) and summer (when they suggest promotion of local production by the relief of silicic acid or iron limitation). These results provide clarity on SAZ seasonal carbon cycling and demonstrate that the magnitude of the annual pCO2 cycle is twice as large as that in the subarctic high-nutrient, low-chlorophyll waters, which can inform the selection of optimal global models in this region. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMGC21C1116G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMGC21C1116G">High-resolution (30 m), annual (1986 - 2010) carbon stocks and fluxes for southeastern US forests derived from remote sensing, inventory data, and a carbon cycle model</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Gu, H.; Zhou, Y.; Williams, C. A. 2016-12-01 Disturbance events are highly heterogeneous in space and time, impacting forest carbon dynamics and challenging the quantification and reporting of carbon stocks and flux. This study documents annual carbon stocks and fluxes from 1986 and 2010 mapped at 30-m resolution across southeastern US forests, characterizing how they respond to disturbances and ensuing regrowth. Forest inventory data (FIA) are used to parameterize a carbon cycle model (CASA) to represent post-disturbance carbon trajectories of carbon pools and fluxes for harvest, fire and bark beetle disturbances of varying severity and across forest types and site productivity settings. Time since disturbance at 30 meters is inferred from two remote-sensing data sources: disturbance year (NAFD, MTBS and ADS) and biomass (NBCD 2000) intersected with inventory-derived curves of biomass accumulation with stand age. All of these elements are combined to map carbon stocks and fluxes at a 30-m resolution for the year 2010, and to march backward in time for continuous, annual reporting. Results include maps of annual carbon stocks and fluxes for forests of the southeastern US, and analysis of spatio-temporal patterns of carbon sources/sinks at local and regional scales. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMED53H0231B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMED53H0231B">International Observe the Moon Night: A Worldwide Public Observing Event that Annually Engages Scientists, Educators, and Citizen Enthusiasts in NASA Science</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Buxner, S.; Jones, A. P.; Bleacher, L.; Wasser, M. L.; Day, B. H.; Shaner, A. J.; Bakerman, M. N.; Joseph, E. 2017-12-01 International Observe the Moon Night (InOMN) is an annual worldwide event, held in the fall, that celebrates lunar and planetary science and exploration. InOMN is sponsored by NASA's Lunar Reconnaissance Orbiter (LRO) in collaboration with NASA's Solar System Exploration Research Virtual Institute (SSERVI), the NASA's Heliophysics Education Consortium, CosmoQuest, Night Sky Network, and Science Festival Alliance. Other key partners include the NASA Museum Alliance, Night Sky Network, and NASA Solar System Ambassadors. In 2017, InOMN will bring together thousands of people across the globe to observe and learn about the Moon and its connection to planetary science. We are partnering with the NASA Science Mission Directorate total solar eclipse team to highlight InOMN as an opportunity to harness and sustain the interest and momentum in space science and observation following the August 21st eclipse. This is part of a new partnership with the Sun-Earth Day team, through the Heliophysics Education Consortium, to better connect the two largest NASA-sponsored public engagement events, increase participation in both events, and share best practices in implementation and evaluation between the teams. Over 3,800 InOMN events have been registered between 2010 and 2016, engaging over 550,000 visitors worldwide. Most InOMN events are held in the United States, with strong representation from many other countries. InOMN events are evaluated to determine the value of the events and to allow us to improve the experience for event hosts and visitors. Our results show that InOMN events are hosted by scientists, educators, and citizen enthusiasts around the world who leverage InOMN to bring communities together, get visitors excited and learn about the Moon - and beyond, and share resources to extend engagement in lunar and planetary science and observation. Through InOMN, we annually provide resources such as event-specific Moon maps, presentations, advertising materials, and </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21304994','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21304994">Cycle flux algebra for ion and water flux through the KcsA channel single-file pore links microscopic trajectories and macroscopic observables.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Oiki, Shigetoshi; Iwamoto, Masayuki; Sumikama, Takashi 2011-01-31 In narrow pore ion channels, ions and water molecules diffuse in a single-file manner and cannot pass each other. Under such constraints, ion and water fluxes are coupled, leading to experimentally observable phenomena such as the streaming potential. Analysis of this coupled flux would provide unprecedented insights into the mechanism of permeation. In this study, ion and water permeation through the KcsA potassium channel was the focus, for which an eight-state discrete-state Markov model has been proposed based on the crystal structure, exhibiting four ion-binding sites. Random transitions on the model lead to the generation of the net flux. Here we introduced the concept of cycle flux to derive exact solutions of experimental observables from the permeation model. There are multiple cyclic paths on the model, and random transitions complete the cycles. The rate of cycle completion is called the cycle flux. The net flux is generated by a combination of cyclic paths with their own cycle flux. T.L. Hill developed a graphical method of exact solutions for the cycle flux. This method was extended to calculate one-way cycle fluxes of the KcsA channel. By assigning the stoichiometric numbers for ion and water transfer to each cycle, we established a method to calculate the water-ion coupling ratio (CR(w-i)) through cycle flux algebra. These calculations predicted that CR(w-i) would increase at low potassium concentrations. One envisions an intuitive picture of permeation as random transitions among cyclic paths, and the relative contributions of the cycle fluxes afford experimental observables. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3031593','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3031593">Cycle Flux Algebra for Ion and Water Flux through the KcsA Channel Single-File Pore Links Microscopic Trajectories and Macroscopic Observables</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> Oiki, Shigetoshi; Iwamoto, Masayuki; Sumikama, Takashi 2011-01-01 In narrow pore ion channels, ions and water molecules diffuse in a single-file manner and cannot pass each other. Under such constraints, ion and water fluxes are coupled, leading to experimentally observable phenomena such as the streaming potential. Analysis of this coupled flux would provide unprecedented insights into the mechanism of permeation. In this study, ion and water permeation through the KcsA potassium channel was the focus, for which an eight-state discrete-state Markov model has been proposed based on the crystal structure, exhibiting four ion-binding sites. Random transitions on the model lead to the generation of the net flux. Here we introduced the concept of cycle flux to derive exact solutions of experimental observables from the permeation model. There are multiple cyclic paths on the model, and random transitions complete the cycles. The rate of cycle completion is called the cycle flux. The net flux is generated by a combination of cyclic paths with their own cycle flux. T.L. Hill developed a graphical method of exact solutions for the cycle flux. This method was extended to calculate one-way cycle fluxes of the KcsA channel. By assigning the stoichiometric numbers for ion and water transfer to each cycle, we established a method to calculate the water-ion coupling ratio (CR w-i) through cycle flux algebra. These calculations predicted that CR w-i would increase at low potassium concentrations. One envisions an intuitive picture of permeation as random transitions among cyclic paths, and the relative contributions of the cycle fluxes afford experimental observables. PMID:21304994 </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AnGeo..36..555F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AnGeo..36..555F">Effects of solar activity and galactic cosmic ray cycles on the modulation of the annual average temperature at two sites in southern Brazil</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Frigo, Everton; Antonelli, Francesco; da Silva, Djeniffer S. S.; Lima, Pedro C. M.; Pacca, Igor I. G.; Bageston, José V. 2018-04-01 Quasi-periodic variations in solar activity and galactic cosmic rays (GCRs) on decadal and bidecadal timescales have been suggested as a climate forcing mechanism for many regions on Earth. One of these regions is southern Brazil, where the lowest values during the last century were observed for the total geomagnetic field intensity at the Earth's surface. These low values are due to the passage of the center of the South Atlantic Magnetic Anomaly (SAMA), which crosses the Brazilian territory from east to west following a latitude of ˜ 26°. In areas with low geomagnetic intensity, such as the SAMA, the incidence of GCRs is increased. Consequently, possible climatic effects related to the GCRs tend to be maximized in this region. In this work, we investigate the relationship between the ˜ 11-year and ˜ 22-year cycles that are related to solar activity and GCRs and the annual average temperature recorded between 1936 and 2014 at two weather stations, both located near a latitude of 26° S but at different longitudes. The first of these stations (Torres - TOR) is located in the coastal region, and the other (Iraí - IRA) is located in the interior, around 450 km from the Atlantic Ocean. Sunspot data and the solar modulation potential for cosmic rays were used as proxies for the solar activity and the GCRs, respectively. Our investigation of the influence of decadal and bidecadal cycles in temperature data was carried out using the wavelet transform coherence (WTC) spectrum. The results indicate that periodicities of 11 years may have continuously modulated the climate at TOR via a nonlinear mechanism, while at IRA, the effects of this 11-year modulation period were intermittent. Four temperature maxima, separated by around 20 years, were detected in the same years at both weather stations. These temperature maxima are almost coincident with the maxima of the odd solar cycles. Furthermore, these maxima occur after transitions from even to odd solar cycles, that is </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20030020828&hterms=Asm&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DAsm','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20030020828&hterms=Asm&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DAsm">Studies of Accreting Neutron Stars with RXTE Cycle 4 Observations: III: TOO Observations of Atoll Sources</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Paciesas, William S. 2002-01-01 NASA Grant NAG 5-9244 provided funds for the research projects 'ASM-Triggered TOO Observations of Kilohertz Oscillations in Five Atoll Sources' and 'Further Measurements of the Kilohertz Oscillations in 4U 1705-44' approved under the Rossi X-ray Timing Explorer (RXTE) Guest Observer Program Cycle 4 and funded under the 1999 NASA Astrophysics Data Program. The principal investigator of the observing time proposals was Dr. E. C. Ford (U. of Amsterdam). The grant was funded for one year beginning 3/15/2000. The original ADP proposal was submitted by Prof. Jan van Paradijs, who passed away in 1999 before the funds were distributed. Prof. Wilham S. Padesas administered the grant during the period of performance. In spite of a wealth of observational data on the kHz QPO in low-mass X-ray binaries (LMXBs), the interpretation of this phenomenon is currently uncertain because the pairs of kHz QPO peaks and the oscillations seen in some Type I X-ray bursts are almost, but not quite, connected by a simple beat frequency relation. Further systematic studies of systems with known QPOs are required in order to better understand the phenomenon. The proposals were intended to contribute to a solution to this confusion by observing the sources as they vary over a wide range of X-ray flux. RXTE target-of-opportunity observations of six transient atoll sources, 4U 0614+09, KS 1732-260, Ser X-1, 4U 1702-42, 4U 1820-30 and 4U 1705-44 were to be performed at various flux levels based on ASM measurements. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016usc..confE.119L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016usc..confE.119L">Influence of the Sun on the Space Weather Conditions: Cycle 24 Observations from 1 AU to Mars</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Lee, Christina 2016-10-01 Motivated by future crewed missions to Mars, there is a growing need to advance our knowledge of the heliospheric conditions between the Earth ( 1 AU) orbit and Mars ( 1.5 AU) orbit locations. Comparative conditions at these locations are of special interest since they are separated by the interplanetary region where most solar wind stream interaction regions develop. These regions alter the propagation of solar-heliospheric disturbances, including the interplanetary CME-driven shocks that create the space radiation (via solar energetic particles) that are hazardous to humans. Although the deep Cycle 23 minimum and the modestly active Cycle 24 maximum have produced generally weaker solar events and heliospheric conditions, observations from solar and planetary missions during the SDO era provide a unique opportunity to study how and to what extent the solar eruptive events impact the local space environments at Earth (and/or STEREO-A) and Mars, and for a given solar-heliospheric event period how the geospace and near-Mars space conditions compare and contrast with one another. Such observations include those from SDO, L1 observers (ACE,WIND,SOHO) and STEREO-A at 1 AU, and Mars Express, MSL, and MAVEN at 1.5 AU. Using these observations, we will highlight a number of Cycle 24 space weather events observed along the 1-AU orbit (at Earth and/or STEREO-A) and Mars that are triggered by CMEs, SEPs, flares, and/or CIRs. Numerical 3D simulations from WSA-Enlil-cone will also be presented to provide global context to the events discussed. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20110007245&hterms=Butterfly&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DButterfly','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20110007245&hterms=Butterfly&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DButterfly">Solar Sources and Geospace Consequences of Interplanetary Magnetic Clouds Observed During Solar Cycle 23</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Gopalswamy, N.; Akiyama, S.; Yashiro, S.; Michalek, G.; Lepping, R. P. 2007-01-01 We present results of a statistical investigation of 99 magnetic clouds (MCs) observed during 1995-2005. The MC-associated coronal mass ejections (CMEs) are faster and wider on the average and originate within +/-30deg from the solar disk center. The solar sources of MCs also followed the butterfly diagram. The correlation between the magnetic field strength and speed of MCs was found to be valid over a much wider range of speeds. The number of south-north (SN) MCs was dominant and decreased with solar cycle, while the number of north-south (NS) MCs increased confirming the odd-cycle behavior. Two-thirds of MCs were geoeffective; the Dst index was highly correlated with speed and magnetic field in MCs as well as their product. Many (55%) fully northward (FN) MCs were geoeffective solely due to their sheaths. The non-geoeffective MCs were slower (average speed approx. 382 km/s), had a weaker southward magnetic field (average approx. -5.2nT), and occurred mostly during the rise phase of the solar activity cycle. </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active">13</li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active">14</li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title28-vol1/pdf/CFR-2012-title28-vol1-sec16-208.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title28-vol1/pdf/CFR-2012-title28-vol1-sec16-208.pdf">28 CFR 16.208 - Annual report.</a> <a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a> 2012-07-01 ... 28 Judicial Administration 1 2012-07-01 2012-07-01 false Annual report. 16.208 Section 16.208... Observation of Parole Commission Meetings § 16.208 Annual report. The Commission shall report annually to Congress regarding its compliance with Sunshine Act requirements, including a tabulation of the total... </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title28-vol1/pdf/CFR-2011-title28-vol1-sec16-208.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title28-vol1/pdf/CFR-2011-title28-vol1-sec16-208.pdf">28 CFR 16.208 - Annual report.</a> <a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a> 2011-07-01 ... 28 Judicial Administration 1 2011-07-01 2011-07-01 false Annual report. 16.208 Section 16.208... Observation of Parole Commission Meetings § 16.208 Annual report. The Commission shall report annually to Congress regarding its compliance with Sunshine Act requirements, including a tabulation of the total... </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title28-vol1/pdf/CFR-2010-title28-vol1-sec16-208.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title28-vol1/pdf/CFR-2010-title28-vol1-sec16-208.pdf">28 CFR 16.208 - Annual report.</a> <a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a> 2010-07-01 ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Annual report. 16.208 Section 16.208... Observation of Parole Commission Meetings § 16.208 Annual report. The Commission shall report annually to Congress regarding its compliance with Sunshine Act requirements, including a tabulation of the total... </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title28-vol1/pdf/CFR-2014-title28-vol1-sec16-208.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title28-vol1/pdf/CFR-2014-title28-vol1-sec16-208.pdf">28 CFR 16.208 - Annual report.</a> <a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a> 2014-07-01 ... 28 Judicial Administration 1 2014-07-01 2014-07-01 false Annual report. 16.208 Section 16.208... Observation of Parole Commission Meetings § 16.208 Annual report. The Commission shall report annually to Congress regarding its compliance with Sunshine Act requirements, including a tabulation of the total... </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.A23J3373B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.A23J3373B">Observations of a stratospheric depletion and annual mean interhemispheric gradient in the atmospheric Ar/N2 ratio from the HIPPO Global campaign</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Bent, J. D.; Keeling, R. F.; Stephens, B. B.; Wofsy, S. C.; Daube, B. C.; Kort, E. A.; Pittman, J. V.; Jimenez-Pizarro, R.; Santoni, G. 2014-12-01 The atmospheric Ar/N2 ratio varies on a seasonal basis due to temperature-dependent solubility changes in the surface ocean. Low signal:noise ratios, limited vertical coverage, and sampler-sampler offsets have historically hampered characterization of vertical and inter-hemispheric gradients. We present data from the HIPPO Global campaign (2009-11) showing that Ar/N2 and interannually-detrended N2O correlate well in the lower stratosphere, suggesting that, as stratospheric air ages and loses N2O to photolysis and photo-oxidation, it also gradually loses argon to gravity as the heavier atom preferentially "rains out" of the air parcel. The HIPPO Ar/N2 data from the lower troposphere also resolve seasonal cycles in each hemisphere, as well as a gradient in the annual mean between hemispheres, with higher values in the southern hemisphere. The HIPPO cycles and inter-hemispheric gradient are in good agreement with data from surface stations. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20170003787&hterms=cycles&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dcycles','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20170003787&hterms=cycles&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dcycles">Predictions of Solar Cycle 24: How are We Doing?</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Pesnell, William D. 2016-01-01 Predictions of solar activity are an essential part of our Space Weather forecast capability. Users are requiring usable predictions of an upcoming solar cycle to be delivered several years before solar minimum. A set of predictions of the amplitude of Solar Cycle 24 accumulated in 2008 ranged from zero to unprecedented levels of solar activity. The predictions formed an almost normal distribution, centered on the average amplitude of all preceding solar cycles. The average of the current compilation of 105 predictions of the annual-average sunspot number is 106 +/- 31, slightly lower than earlier compilations but still with a wide distribution. Solar Cycle 24 is on track to have a below-average amplitude, peaking at an annual sunspot number of about 80. Our need for solar activity predictions and our desire for those predictions to be made ever earlier in the preceding solar cycle will be discussed. Solar Cycle 24 has been a below-average sunspot cycle. There were peaks in the daily and monthly averaged sunspot number in the Northern Hemisphere in 2011 and in the Southern Hemisphere in 2014. With the rapid increase in solar data and capability of numerical models of the solar convection zone we are developing the ability to forecast the level of the next sunspot cycle. But predictions based only on the statistics of the sunspot number are not adequate for predicting the next solar maximum. I will describe how we did in predicting the amplitude of Solar Cycle 24 and describe how solar polar field predictions could be made more accurate in the future. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1818082D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1818082D">Effects of dairy manure management in annual and perennial cropping systems on soil microbial communities associated with in situ N2O fluxes</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Dunfield, Kari; Thompson, Karen; Bent, Elizabeth; Abalos, Diego; Wagner-Riddle, Claudia 2016-04-01 Liquid dairy manure (LDM) application and ploughing events may affect soil microbial community functioning differently between perennial and annual cropping systems due to plant-specific characteristics stimulating changes in microbial community structure. Understanding how these microbial communities change in response to varied management, and how these changes relate to in situ N2O fluxes may allow the creation of predictive models for use in the development of best management practices (BMPs) to decrease nitrogen (N) losses through choice of crop, plough, and LDM practices. Our objectives were to contrast changes in the population sizes and community structures of genes associated with nitrifier (amoA, crenamoA) and denitrifier (nirK, nirS, nosZ) communities in differently managed annual and perennial fields demonstrating variation in N2O flux, and to determine if differences in these microbial communities were linked to the observed variation in N2O fluxes. Soil was sampled in 2012 and in 2014 in a 4-ha spring-applied LDM grass-legume (perennial) plot and two 4-ha corn (annual) treatments under fall or spring LDM application. Soil DNA was extracted and used to target N-cycling genes via qPCR (n=6) and for next-generation sequencing (Illumina Miseq) (n=3). Significantly higher field-scale N2O fluxes were observed in the annual plots compared to the perennial system; however N2O fluxes increased after plough down of the perennial plot. Nonmetric multidimensional scaling (NMS) indicated differences in N-cycling communities between annual and perennial cropping systems, and some communities became similar between annual and perennial plots after ploughing. Shifts in these communities demonstrated relationships with agricultural management, which were associated with differences in N2O flux. Indicator species analysis was used to identify operational taxonomic units (OTUs) most responsible for community shifts related to management. Nitrifying and denitrifying soil </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AtmRe.202..205S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AtmRe.202..205S">Characterization of the Sahelian-Sudan rainfall based on observations and regional climate models</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Salih, Abubakr A. M.; Elagib, Nadir Ahmed; Tjernström, Michael; Zhang, Qiong 2018-04-01 The African Sahel region is known to be highly vulnerable to climate variability and change. We analyze rainfall in the Sahelian Sudan in terms of distribution of rain-days and amounts, and examine whether regional climate models can capture these rainfall features. Three regional models namely, Regional Model (REMO), Rossby Center Atmospheric Model (RCA) and Regional Climate Model (RegCM4), are evaluated against gridded observations (Climate Research Unit, Tropical Rainfall Measuring Mission, and ERA-interim reanalysis) and rain-gauge data from six arid and semi-arid weather stations across Sahelian Sudan over the period 1989 to 2008. Most of the observed rain-days are characterized by weak (0.1-1.0 mm/day) to moderate (> 1.0-10.0 mm/day) rainfall, with average frequencies of 18.5% and 48.0% of the total annual rain-days, respectively. Although very strong rainfall events (> 30.0 mm/day) occur rarely, they account for a large fraction of the total annual rainfall (28-42% across the stations). The performance of the models varies both spatially and temporally. RegCM4 most closely reproduces the observed annual rainfall cycle, especially for the more arid locations, but all of the three models fail to capture the strong rainfall events and hence underestimate its contribution to the total annual number of rain-days and rainfall amount. However, excessive moderate rainfall compensates this underestimation in the models in an annual average sense. The present study uncovers some of the models' limitations in skillfully reproducing the observed climate over dry regions, will aid model users in recognizing the uncertainties in the model output and will help climate and hydrological modeling communities in improving models. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930073153&hterms=organic+compound+marine&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dorganic%2Bcompound%2Bmarine','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930073153&hterms=organic+compound+marine&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dorganic%2Bcompound%2Bmarine">Theoretical studies of the marine sulfur cycle</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Toon, Owen B.; Kasting, James B.; Liu, May S. 1985-01-01 Several reduced sulfur compounds are produced by marine organisms and then enter the atmosphere, where they are oxidized and ultimately returned to the ocean or the land. The oceanic dimethyl sulfide (DMS) flux, in particular, represents a significant fraction of the annual global sulfur input to the atmosphere. In the atmosphere, this gas is converted to sulfur dioxide (SO2), methane sulfonic acid, and other organic acids which are relatively stable and about which little is known. SO2 is a short lived gas which, in turn, is converted to sulfuric acid and other sulfate compounds which contribute significantly to acid rain. Because of the complexity of the sulfur system, it is not well understood even in the unperturbed atmosphere. However, a number of new observations and experiments have led to a significant increase in the understanding of this system. A number of one dimensional model experiments were conducted on the gas phase part of the marine sulfur cycle. The results indicate the measured concentration of DMS and the amplitude of its diurnal cycle are in agreement with estimates of its global flux. It was also found that DMS can make a large contribution to the background SO2 concentration in the free troposphere. Estimates of CS2 concentrations in the atmosphere are inconsistent with estimated fluxes; however, measured reaction rates are consistent with the observed steep tropospheric gradient in CS2. Observations of CS2 are extremely sparse. Further study is planned. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.G41B0935W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.G41B0935W">Rapid changes in the seasonal sea level cycle along the US Gulf coast in the early 21st century</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Wahl, T.; Calafat, F. M.; Luther, M. E. 2013-12-01 The seasonal cycle is an energetic component in the sea level spectrum and dominates the intra-annual sea level variability outside the semidiurnal and diurnal tidal bands in most regions. Changes in the annual or semi-annual amplitudes or phase lags have an immediate impact on marine coastal systems. Increases in the amplitudes or phase shifts towards the storm surge season may for instance exacerbate the risk of coastal flooding and/or beach erosion, and the ecological health of estuarine systems is also coupled to the seasonal sea level cycle. Here, we investigate the temporal variability of the seasonal harmonics along the US Gulf of Mexico (GOM) coastline using records from 13 tide gauges providing at least 30 years of data in total and at least 15 years for the period after 1990. The longest records go back to the early 20th century. Running Fourier analysis (with a window length of 5-years) is used to extract the seasonal harmonics from the observations. The resulting time series show a considerable decadal variability and no longer-term changes are found in the phase lags and the semi-annual amplitude. The amplitude of the dominating annual cycle in contrast shows a tendency towards higher values since the turn of the century at tide gauges in the eastern part of the GOM. This increase of up to more than 25% is found to be significant at the 90% confidence level for most tide gauges along the coastline of West Florida and at the 75% confidence level for virtually all stations in the eastern GOM (from Key West to Dauphin Island). Monthly mean sea level sub-series show that the changes are partly due to smaller values in the cold season but mostly a result of higher values in the warm season, i.e. sea levels tend to be higher during the hurricane season. We use information on the steric sea level component, sea surface and air temperature, wind forcing, precipitation, and sea level pressure to explain the mechanisms driving the decadal variability in the </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016usc..confE.128I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016usc..confE.128I">Variations in the Geometry of the Sun Observed with HMI/SDO during Cycle 24</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Irbah, Abdenour; Damé, Luc 2016-10-01 Geometry of the Sun and its temporal variations observed with ground-based instruments are still subject to questioning. The geometry, which inform us on the interior of the Sun, is achieved by high resolution measurements of the radius, oblateness and gravitational moments c2 and c4. Several space missions were developed these last decades to validate or refute its observed variations with ground experiments and the link with solar activity. High angular resolution of solar radius measurements and its long term trend is however a challenge in Space. The first attempts with MDI (Soho) then SODISM (PICARD) and HMI (SDO) revealed the difficulties of such measures due to hostile environment which introduces thermal variations of the instruments along the satellite orbit. These variations have non negligible impacts on optical properties of onboard telescopes and therefore on images and parameters extracted, such as the solar radius. We need to take into account the thermal behavior (housekeeping data) recorded together with the science data to correct them. Solar oblateness and gravitational moments ask for both special spacecraft operations and appropriate processing methods to obtain the needed accuracy for their measurements. We present here some results on the solar radius and oblateness obtained with HMI data. Images analysed cover six years since May 1, 2010 (beginning of Cycle 24), until now. Results show that the geometry of the Sun presents some temporal variations related to solar activity. In particular we evidence a Quasi-Biennale Oscillation (QBO) correlated with the solar cycle, as was observed with ground observations. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29330030','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29330030">Health impact assessment of cycling network expansions in European cities.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Mueller, Natalie; Rojas-Rueda, David; Salmon, Maëlle; Martinez, David; Ambros, Albert; Brand, Christian; de Nazelle, Audrey; Dons, Evi; Gaupp-Berghausen, Mailin; Gerike, Regine; Götschi, Thomas; Iacorossi, Francesco; Int Panis, Luc; Kahlmeier, Sonja; Raser, Elisabeth; Nieuwenhuijsen, Mark 2018-04-01 We conducted a health impact assessment (HIA) of cycling network expansions in seven European cities. We modeled the association between cycling network length and cycling mode share and estimated health impacts of the expansion of cycling networks. First, we performed a non-linear least square regression to assess the relationship between cycling network length and cycling mode share for 167 European cities. Second, we conducted a quantitative HIA for the seven cities of different scenarios (S) assessing how an expansion of the cycling network [i.e. 10% (S1); 50% (S2); 100% (S3), and all-streets (S4)] would lead to an increase in cycling mode share and estimated mortality impacts thereof. We quantified mortality impacts for changes in physical activity, air pollution and traffic incidents. Third, we conducted a cost-benefit analysis. The cycling network length was associated with a cycling mode share of up to 24.7% in European cities. The all-streets scenario (S4) produced greatest benefits through increases in cycling for London with 1,210 premature deaths (95% CI: 447-1,972) avoidable annually, followed by Rome (433; 95% CI: 170-695), Barcelona (248; 95% CI: 86-410), Vienna (146; 95% CI: 40-252), Zurich (58; 95% CI: 16-100) and Antwerp (7; 95% CI: 3-11). The largest cost-benefit ratios were found for the 10% increase in cycling networks (S1). If all 167 European cities achieved a cycling mode share of 24.7% over 10,000 premature deaths could be avoided annually. In European cities, expansions of cycling networks were associated with increases in cycling and estimated to provide health and economic benefits. Copyright © 2018 Elsevier Inc. All rights reserved. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20120010218&hterms=Butterfly&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DButterfly','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20120010218&hterms=Butterfly&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DButterfly">Behavior of Solar Cycles 23 and 24 Revealed by Microwave Observations</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Gopalswamy, N.; Yashiro, S.; Maekelae, P.; Michalek, G.; Shibasaki, K.; Hathaway, D. H. 2012-01-01 Using magnetic and microwave butterfly diagrams, we compare the behavior of solar polar regions to show that (1) the polar magnetic field and the microwave brightness temperature during solar minimum substantially diminished during the cycle 23/24 minimum compared to the 22/23 minimum. (2) The polar microwave brightness temperature (Tb) seems to be a good proxy for the underlying magnetic field strength (B). The analysis indicates a relationship, B = 0.0067Tb - 70, where B is in G and Tb in K. (3) Both the brightness temperature and the magnetic field strength show north-south asymmetry most of the time except for a short period during the maximum phase. (4) The rush-to-the-pole phenomenon observed in the prominence eruption (PE) activity seems to be complete in the northern hemisphere as of 2012 March. (5) The decline of the microwave brightness temperature in the north polar region to the quiet-Sun levels and the sustained PE activity poleward of 60degN suggest that solar maximum conditions have arrived at the northern hemisphere. The southern hemisphere continues to exhibit conditions corresponding to the rise phase of solar cycle 24. Key words: Sun: chromosphere Sun: coronal mass ejections (CMEs) Sun: filaments, prominences Sun: photosphere Sun: radio radiation Sun: surface magnetism </li> <li> <a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=101120&keyword=information+AND+organization&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=101120&keyword=information+AND+organization&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50">NATO/CCMS PILOT STUDY - CLEAN PRODUCTS AND PROCESSES (PHASE I) 2000 ANNUAL REPORT, NUMBER 242</a> <a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a> This annual report presents the proceedings of the Third Annual NATO/CCMS pilot study meeting in Copenhagen, Denmark. Guest speakers focused on efforts in the area of research of clean products and processes, life cycle analysis, computer tools and pollution prevention. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22663164','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22663164">Trends and weekly and seasonal cycles in the rate of errors in the clinical management of hospitalized patients.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Buckley, David; Bulger, David 2012-08-01 Studies on the rate of adverse events in hospitalized patients seldom examine temporal patterns. This study presents evidence of both weekly and annual cycles. The study is based on a large and diverse data set, with nearly 5 yrs of data from a voluntary staff-incident reporting system of a large public health care provider in rural southeastern Australia. The data of 63 health care facilities were included, ranging from large non-metropolitan hospitals to small community and aged health care facilities. Poisson regression incorporating an observation-driven autoregressive effect using the GLARMA framework was used to explain daily error counts with respect to long-term trend and weekly and annual effects, with procedural volume as an offset. The annual pattern was modeled using a first-order sinusoidal effect. The rate of errors reported demonstrated an increasing annual trend of 13.4% (95% confidence interval [CI] 10.6% to 16.3%); however, this trend was only significant for errors of minor or no harm to the patient. A strong "weekend effect" was observed. The incident rate ratio for the weekend versus weekdays was 2.74 (95% CI 2.55 to 2.93). The weekly pattern was consistent for incidents of all levels of severity, but it was more pronounced for less severe incidents. There was an annual cycle in the rate of incidents, the number of incidents peaking in October, on the 282 nd day of the year (spring in Australia), with an incident rate ratio 1.09 (95% CI 1.05 to 1.14) compared to the annual mean. There was no so-called "killing season" or "July effect," as the peak in incident rate was not related to the commencement of work by new medical school graduates. The major finding of this study is the rate of adverse events is greater on weekends and during spring. The annual pattern appears to be unrelated to the commencement of new graduates and potentially results from seasonal variation in the case mix of patients or the health of the medical workforce that alters </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20020051098&hterms=thunder+lightning&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dthunder%2Blightning','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20020051098&hterms=thunder+lightning&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dthunder%2Blightning">Global Frequency and Distribution of Lightning as Observed from Space by the Optical Transient Detector</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Christian, Hugh J.; Blakeslee, Richard J.; Boccippio, Dennis J.; Boeck, William L.; Bucchler, Dennis E.; Driscoll, Kevin T.; Goodman, Steven J.; Hall, John M.; Koshak, William J.; Mach, Douglas M.; <a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20020051098'); toggleEditAbsImage('author_20020051098_show'); toggleEditAbsImage('author_20020051098_hide'); "> <img style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_20020051098_show"> <img style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_20020051098_hide"> 2002-01-01 The Optical Transient Detector (OTD) is a space-based instrument specifically designed to detect and locate lightning discharges as it orbits the Earth. This instrument is a scientific payload on the MicroLab-1 satellite that was launched into a low-earth, 70 deg. inclination orbit in April 1995. Given the orbital trajectory of the satellite, most regions of the earth are observed by the OTD instrument more than 400 times during a one year period, and the average duration of each observation is 2 minutes. The OTD instrument optically detects lightning flashes that occur within its 1300x1300 sq km field-of-view during both day and night conditions. A statistical examination of OTD lightning data reveals that nearly 1.4 billion flashes occur annually over the entire earth. This annual flash count translates to an average of 44 +/- 5 lightning flashes (intracloud and cloud-to-ground combined) occurring around the globe every second, which is well below the traditional estimate of 100 flashes per second that was derived in 1925 from world thunder-day records. The range of uncertainty for the OTD global totals represents primarily the uncertainty (and variability) in the flash detection efficiency of the instrument. The OTD measurements have been used to construct lightning climatology maps that demonstrate the geographical and seasonal distribution of lightning activity for the globe. An analysis of this annual lightning distribution confirms that lightning occurs mainly over land areas, with an average land:ocean ratio of 10:1. A dominant Northern Hemisphere summer peak occurs in the annual cycle, and evidence is found for a tropically-driven semiannual cycle. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140017090','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140017090">Influence of Observed Diurnal Cycles of Aerosol Optical Depth on Aerosol Direct Radiative Effect</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Arola, A.; Eck, T. F.; Huttunen, J.; Lehtinen, K. E. J.; Lindfors, A. V.; Myhre, G.; Smirinov, A.; Tripathi, S. N.; Yu, H. 2013-01-01 The diurnal variability of aerosol optical depth (AOD) can be significant, depending on location and dominant aerosol type. However, these diurnal cycles have rarely been taken into account in measurement-based estimates of aerosol direct radiative forcing (ADRF) or aerosol direct radiative effect (ADRE). The objective of our study was to estimate the influence of diurnal aerosol variability at the top of the atmosphere ADRE estimates. By including all the possible AERONET sites, we wanted to assess the influence on global ADRE estimates. While focusing also in more detail on some selected sites of strongest impact, our goal was to also see the possible impact regionally.We calculated ADRE with different assumptions about the daily AOD variability: taking the observed daily AOD cycle into account and assuming diurnally constant AOD. Moreover, we estimated the corresponding differences in ADREs, if the single AOD value for the daily mean was taken from the the Moderate Resolution Imaging Spectroradiometer (MODIS) Terra or Aqua overpass times, instead of accounting for the true observed daily variability. The mean impact of diurnal AOD variability on 24 h ADRE estimates, averaged over all AERONET sites, was rather small and it was relatively small even for the cases when AOD was chosen to correspond to the Terra or Aqua overpass time. This was true on average over all AERONET sites, while clearly there can be much stronger impact in individual sites. Examples of some selected sites demonstrated that the strongest observed AOD variability (the strongest morning afternoon contrast) does not typically result in a significant impact on 24 h ADRE. In those cases, the morning and afternoon AOD patterns are opposite and thus the impact on 24 h ADRE, when integrated over all solar zenith angles, is reduced. The most significant effect on daily ADRE was induced by AOD cycles with either maximum or minimum AOD close to local noon. In these cases, the impact on 24 h ADRE was </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1810572S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1810572S">Inter-annual variations of CO2 observed by commercial airliner in the CONTRAIL project</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Sawa, Yousuke; Machida, Toshinobu; Matsueda, Hidekazu; Niwa, Yosuke; Umezawa, Taku 2016-04-01 Since 2005, we have conducted an observation program for greenhouse gases using the passenger aircraft of the Japan Airlines named Comprehensive Observation Network for TRace gases by AIrLiner (CONTRAIL). Over the past 10 years, successful operation of Continuous CO2 Measuring Equipment (CME) has delivered more than 6 million in-situ CO2 data from about 12000 flights between Japan and Europe, Australia, North America, or Asia. The large number of CME data enable us to well characterize spatial distributions and seasonal changes of CO2 in wide regions of the globe especially the Asia-Pacific regions. While the mean growth rates for the past 10 years were about 2 ppm/year, large growth rates of about 3 ppm/year were found in the wide latitudinal bands from 30S to 70N from the second half of 2012 to the first half of 2013. The multiyear data sets have the potential to help understand the global/regional CO2 budget. One good example is the significant inter-annual difference in CO2 vertical profiles observed over Singapore between October 2014 and October 2015, which is attributable to the massive biomass burnings in Indonesia in 2015. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25913078','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25913078">Annual incidence of mortality related to hypertensive disease in Canada and associations with heliophysical parameters.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Caswell, Joseph M; Carniello, Trevor N; Murugan, Nirosha J 2016-01-01 Increasing research into heliobiology and related fields has revealed a myriad of potential relationships between space weather factors and terrestrial biology. Additionally, many studies have indicated cyclicity in incidence of various diseases along with many aspects of cardiovascular function. The current study examined annual mortality associated with hypertensive diseases in Canada from 1979 to 2009 for periodicities and linear relationships with a range of heliophysical parameters. Analyses indicated a number of significant lagged correlations between space weather and hypertensive mortality, with solar wind plasma beta identified as the likely source of these relationships. Similar periodicities were observed for geomagnetic activity and hypertensive mortality. A significant rhythm was revealed for hypertensive mortality centered on a 9.6-year cycle length, while geomagnetic activity was fit with a 10.1-year cycle. Cross-correlograms of mortality with space weather demonstrated a 10.67-year periodicity coinciding with the average 10.6-year solar cycle length for the time period examined. Further quantification and potential implications are discussed. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016IJBm...60....9C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016IJBm...60....9C">Annual incidence of mortality related to hypertensive disease in Canada and associations with heliophysical parameters</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Caswell, Joseph M.; Carniello, Trevor N.; Murugan, Nirosha J. 2016-01-01 Increasing research into heliobiology and related fields has revealed a myriad of potential relationships between space weather factors and terrestrial biology. Additionally, many studies have indicated cyclicity in incidence of various diseases along with many aspects of cardiovascular function. The current study examined annual mortality associated with hypertensive diseases in Canada from 1979 to 2009 for periodicities and linear relationships with a range of heliophysical parameters. Analyses indicated a number of significant lagged correlations between space weather and hypertensive mortality, with solar wind plasma beta identified as the likely source of these relationships. Similar periodicities were observed for geomagnetic activity and hypertensive mortality. A significant rhythm was revealed for hypertensive mortality centered on a 9.6-year cycle length, while geomagnetic activity was fit with a 10.1-year cycle. Cross-correlograms of mortality with space weather demonstrated a 10.67-year periodicity coinciding with the average 10.6-year solar cycle length for the time period examined. Further quantification and potential implications are discussed. </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active">14</li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active">15</li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title10-vol2/pdf/CFR-2011-title10-vol2-sec171-15.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title10-vol2/pdf/CFR-2011-title10-vol2-sec171-15.pdf">10 CFR 171.15 - Annual fees: Reactor licenses and independent spent fuel storage licenses.</a> <a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a> 2011-01-01 ... 10 Energy 2 2011-01-01 2011-01-01 false Annual fees: Reactor licenses and independent spent fuel... REACTOR LICENSES AND FUEL CYCLE LICENSES AND MATERIALS LICENSES, INCLUDING HOLDERS OF CERTIFICATES OF... NRC § 171.15 Annual fees: Reactor licenses and independent spent fuel storage licenses. (a) Each... </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title10-vol2/pdf/CFR-2010-title10-vol2-sec171-15.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title10-vol2/pdf/CFR-2010-title10-vol2-sec171-15.pdf">10 CFR 171.15 - Annual fees: Reactor licenses and independent spent fuel storage licenses.</a> <a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a> 2010-01-01 ... 10 Energy 2 2010-01-01 2010-01-01 false Annual fees: Reactor licenses and independent spent fuel... REACTOR LICENSES AND FUEL CYCLE LICENSES AND MATERIALS LICENSES, INCLUDING HOLDERS OF CERTIFICATES OF... NRC § 171.15 Annual fees: Reactor licenses and independent spent fuel storage licenses. (a) Each... </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020044133','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020044133">Science and Observation Recommendations for Future NASA Carbon Cycle Research</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> McClain, Charles R.; Collatz, G. J.; Kawa, S. R.; Gregg, W. W.; Gervin, J. C.; Abshire, J. B.; Andrews, A. E.; Behrenfeld, M. J.; Demaio, L. D.; Knox, R. G. 2002-01-01 Between October 2000 and June 2001, an Agency-wide planning, effort was organized by elements of NASA Goddard Space Flight Center (GSFC) to define future research and technology development activities. This planning effort was conducted at the request of the Associate Administrator of the Office of Earth Science (Code Y), Dr. Ghassem Asrar, at NASA Headquarters (HQ). The primary points of contact were Dr. Mary Cleave, Deputy Associate Administrator for Advanced Planning at NASA HQ (Headquarters) and Dr. Charles McClain of the Office of Global Carbon Studies (Code 970.2) at GSFC. During this period, GSFC hosted three workshops to define the science requirements and objectives, the observational and modeling requirements to meet the science objectives, the technology development requirements, and a cost plan for both the science program and new flight projects that will be needed for new observations beyond the present or currently planned. The plan definition process was very intensive as HQ required the final presentation package by mid-June 2001. This deadline was met and the recommendations were ultimately refined and folded into a broader program plan, which also included climate modeling, aerosol observations, and science computing technology development, for contributing to the President's Climate Change Research Initiative. This technical memorandum outlines the process and recommendations made for cross-cutting carbon cycle research as presented in June. A separate NASA document outlines the budget profiles or cost analyses conducted as part of the planning effort. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150010743','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150010743">The Study of TeV Variability and the Duty Cycle of Mrk 421 from 3 Yr of Observations with the Milagro Observatory</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Abdo, A. A.; Abeysekara, A. U.; Allen, B. T.; Aune, T.; Barber, A. S.; Berley, D.; Braun, J.; Chen, C.; Hays, E.; McEnery, J. E. 2014-01-01 TeV-flaring activity with timescales as short as tens of minutes and an orphan TeV flare have been observed from the blazar Markarian 421 (Mrk 421). The TeV emission from Mrk 421 is believed to be produced by leptonic synchrotron self-Compton (SSC) emission. In this scenario, correlations between the X-ray and the TeV fluxes are expected, TeV orphan flares are hardly explained, and the activity (measured as duty cycle) of the source at TeV energies is expected to be equal to or less than that observed in X-rays if only SSC is considered. To estimate the TeV duty cycle of Mrk 421 and to establish limits on its variability at different timescales, we continuously observed Mrk 421 with the Milagro observatory. Mrk 421 was detected by Milagro with a statistical significance of 7.1 standard deviations between 2005 September 21 and 2008 March 15. The observed spectrum is consistent with previous observations by VERITAS. We estimate the duty cycle of Mrk 421 for energies above 1 TeV for different hypotheses of the baseline flux and for different flare selections and we compared our results with the X-ray duty cycle estimated by Resconi et al. The robustness of the results is discussed. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19950007851','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19950007851">Global surface-based cloud observation for ISCCP</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> 1994-01-01 Visual observations of cloud cover are hindered at night due to inadequate illumination of the clouds. This usually leads to an underestimation of the average cloud cover at night, especially for the amounts of middle and high clouds, in climatologies on surface observations. The diurnal cycles of cloud amounts, if based on all the surface observations, are therefore in error, but they can be obtained more accurately if the nighttime observations are screened to select those made under sufficient moonlight. Ten years of nighttime weather observations from the northern hemisphere in December were classified according to the illuminance of moonlight or twilight on the cloud tops, and a threshold level of illuminance was determined, above which the clouds are apparently detected adequately. This threshold corresponds to light from a full moon at an elevation angle of 6 degrees or from a partial moon at higher elevation, or twilight from the sun less than 9 degrees below the horizon. It permits the use of about 38% of the observations made with the sun below the horizon. The computed diurnal cycles of total cloud cover are altered considerably when this moonlight criterion is imposed. Maximum cloud cover over much of the ocean is now found to be at night or in the morning, whereas computations obtained without benefit of the moonlight criterion, as in our published atlases, showed the time of maximum to be noon or early afternoon in many regions. Cloud cover is greater at night than during the day over the open oceans far from the continents, particularly in summer. However, near noon maxima are still evident in the coastal regions, so that the global annual average oceanic cloud cover is still slightly greater during the day than at night, by 0.3%. Over land, where daytime maxima are still obtained but with reduced amplitude, average cloud cover is 3.3% greater during the daytime. The diurnal cycles of total cloud cover we obtain are compared with those of ISCCP for a </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMGC53F..07L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMGC53F..07L">Recent trends in vegetation greenness in China significantly altered annual evapotranspiration and water yield</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Liu, Y.; Xiao, J. 2017-12-01 There has been growing evidence that vegetation greenness has been increasing in many parts of the northern middle and high latitudes including China during the last three to four decades. However, the effects of vegetation greening particularly afforestation on the hydrologic cycle have been controversial. We used a process-based ecosystem model and a satellite-derived leaf area index (LAI) dataset to examine how the changes in vegetation greenness affected annual evapotranspiration (ET) and water yield for China over the period from 2000 to 2014. Significant trends in vegetation greenness were observed in 26.1% of China's land area. We used two model simulations driven with original and detrended LAI, respectively, to assess the effects of vegetation greening and browning on terrestrial ET and water yield. On a per-pixel basis, vegetation greening increased annual ET and decreased water yield or weakened the increase in water yield; vegetation browning reduced ET and increased water yield or weakened the decrease in water yield. At the large river basin and national scales, the greening trends had positive effects on annual ET and had negative effects on water yield. Our results showed that the effects of the greenness changes on ET and water yield varied with spatial scale. Afforestation efforts perhaps should focus on southern China with larger water supply given the water crisis in northern China and the negative effects of vegetation greening on water yield. Future studies on the effects of the greenness changes on the hydrologic cycle are needed to account for the feedbacks to the climate. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.H23N..03M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.H23N..03M">Fraction of the global water cycle observed by SMAP</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Mccoll, K. A.; Entekhabi, D.; Alemohammad, S. H.; Akbar, R.; Konings, A. G.; Yueh, S. H. 2016-12-01 Sparse and uneven observations have made it difficult to quantify the global distribution and dynamics of surface soil moisture (SSM). Using a full year of global observations from NASA's Soil Moisture Active Passive (SMAP) mission, we show here that SSM - a storage believed to make up less than 0.001% of the global freshwater budget by volume, and equivalent to an, on average, 8-mm thin layer of water covering all land surfaces - plays a very significant role in the water cycle, retaining a median 16% of precipitation falling on land after 3 days. Furthermore, the retained fraction of the SSM storage after 3 days is highest (lowest) over arid (wet) regions, and in regions where drainage to groundwater storage is lowest (highest). The retained fraction decreases monotonically with increasing mean SSM. Regions of low retained fraction broadly correspond spatially with regions where groundwater recharge and groundwater storage are both largest. These analyses are the first global estimates - derived from measurements rather than models - of both the mean magnitude and memory time scales of the SSM storage. Beyond the fundamental importance of characterizing the magnitude and response time scales of Earth's water storages, a key application of these results is in identifying regions with strong land-atmosphere coupling. Significant soil moisture memory is a necessary condition for land-atmosphere feedbacks. These results may therefore have particularly important implications for short-term weather forecasting of extreme precipitation events and floods. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28570219','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28570219">Experimental and observational studies find contrasting responses of soil nutrients to climate change.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Yuan, Z Y; Jiao, F; Shi, X R; Sardans, Jordi; Maestre, Fernando T; Delgado-Baquerizo, Manuel; Reich, Peter B; Peñuelas, Josep 2017-06-01 Manipulative experiments and observations along environmental gradients, the two most common approaches to evaluate the impacts of climate change on nutrient cycling, are generally assumed to produce similar results, but this assumption has rarely been tested. We did so by conducting a meta-analysis and found that soil nutrients responded differentially to drivers of climate change depending on the approach considered. Soil carbon, nitrogen, and phosphorus concentrations generally decreased with water addition in manipulative experiments but increased with annual precipitation along environmental gradients. Different patterns were also observed between warming experiments and temperature gradients. Our findings provide evidence of inconsistent results and suggest that manipulative experiments may be better predictors of the causal impacts of short-term (months to years) climate change on soil nutrients but environmental gradients may provide better information for long-term correlations (centuries to millennia) between these nutrients and climatic features. Ecosystem models should consequently incorporate both experimental and observational data to properly assess the impacts of climate change on nutrient cycling. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017A%26A...605A..19O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017A%26A...605A..19O">Fifteen years in the high-energy life of the solar-type star HD 81809. XMM-Newton observations of a stellar activity cycle</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Orlando, S.; Favata, F.; Micela, G.; Sciortino, S.; Maggio, A.; Schmitt, J. H. M. M.; Robrade, J.; Mittag, M. 2017-09-01 Context. The modulation of the activity level of solar-like stars is commonly revealed by cyclic variations in their chromospheric indicators, such as the Ca II H&K S-index, similarly to what is observed in our Sun. However, while the variation of solar activity is also reflected in the cyclical modulation of its coronal X-ray emission, similar behavior has only been discovered in a few stars other than the Sun. Aims: The data set of the long-term XMM-Newton monitoring program of HD 81809 is analyzed to study its X-ray cycle, investigate if the latter is related to the chromospheric cycle, infer the structure of the corona of HD 81809, and explore if the coronal activity of HD 81809 can be ascribed to phenomena similar to solar activity and, therefore, considered an extension of the solar case. Methods: We analyzed the observations of HD 81809 performed with XMM-Newton with a regular cadence of six months from 2001 to 2016, which represents one of the longest available observational baseline ( 15 yr) for a solar-like star with a well-studied chromospheric cycle (with a period of 8 yr). We investigated the modulation of coronal luminosity and temperature and its relation with the chromospheric cycle. We interpreted the data in terms of a mixture of solar-like coronal regions, adopting a method originally proposed to study the Sun as an X-ray star. Results: The observations show a well-defined regular cyclic modulation of the X-ray luminosity that reflects the activity level of HD 81809. The data covers approximately two cycles of coronal activity; the modulation has an amplitude of a factor of 5 (excluding evident flares, as in the June 2002 observation) and a period of 7.3 ± 1.5 yr, which is consistent with that of the chromospheric cycle. We demonstrate that the corona of HD 81809 can be interpreted as an extension of the solar case and can be modeled with a mixture of solar-like coronal regions along the whole cycle. The activity level is mainly determined by </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/21612934-internal-cycle-modeling-environmental-assessment-multiple-cycle-consumer-products','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/21612934-internal-cycle-modeling-environmental-assessment-multiple-cycle-consumer-products">Internal cycle modeling and environmental assessment of multiple cycle consumer products</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Tsiliyannis, C.A., E-mail: anion@otenet.gr 2012-01-15 Highlights: Black-Right-Pointing-Pointer Dynamic flow models are presented for remanufactured, reused or recycled products. Black-Right-Pointing-Pointer Early loss and stochastic return are included for fast and slow cycling products. Black-Right-Pointing-Pointer The reuse-to-input flow ratio (Internal Cycle Factor, ICF) is determined. Black-Right-Pointing-Pointer The cycle rate, which is increasing with the ICF, monitors eco-performance. Black-Right-Pointing-Pointer Early internal cycle losses diminish the ICF, the cycle rate and performance. - Abstract: Dynamic annual flow models incorporating consumer discard and usage loss and featuring deterministic and stochastic end-of-cycle (EOC) return by the consumer are developed for reused or remanufactured products (multiple cycle products, MCPs), including fast andmore » slow cycling, short and long-lived products. It is shown that internal flows (reuse and overall consumption) increase proportionally to the dimensionless internal cycle factor (ICF) which is related to environmental impact reduction factors. The combined reuse/recycle (or cycle) rate is shown capable for shortcut, albeit effective, monitoring of environmental performance in terms of waste production, virgin material extraction and manufacturing impacts of all MCPs, a task, which physical variables (lifetime, cycling frequency, mean or total number of return trips) and conventional rates, via which environmental policy has been officially implemented (e.g. recycling rate) cannot accomplish. The cycle rate is shown to be an increasing (hyperbolic) function of ICF. The impact of the stochastic EOC return characteristics on total reuse and consumption flows, as well as on eco-performance, is assessed: symmetric EOC return has a small, positive effect on performance compared to deterministic, while early shifted EOC return is more beneficial. In order to be efficient, environmental policy should set higher minimum reuse targets for higher trippage MCPs </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.4185T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.4185T">Functionalised carboxylic acids in atmospheric particles: An annual cycle revealing seasonal trends and possible sources</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Teich, Monique; van Pinxteren, Dominik; Herrmann, Hartmut 2013-04-01 Carboxylic acids represent a major fraction of the water soluble organic carbon (WSOC) in atmospheric particles. Among the particle phase carboxylic acids, straight-chain monocarboxylic acids (MCA) and dicarboxylic acids (DCA) with 2-10 carbon atoms have extensively been studied in the past. However, only a few studies exist dealing with functionalised carboxylic acids, i.e. having additional hydroxyl-, oxo- or nitro-groups. Regarding atmospheric chemistry, these functionalised carboxylic acids are of particular interest as they are supposed to be formed during atmospheric oxidation processes, e.g. through radical reactions. Therefore they can provide insights into the tropospheric multiphase chemistry. During this work 28 carboxylic acids (4 functionalised aliphatic MCAs, 5 aromatic MCAs, 3 nitroaromatic MCAs, 6 aliphatic DCAs, 6 functionalised aliphatic DCAs, 4 aromatic DCAs) were quantitatively determined in 256 filter samples taken at the rural research station Melpitz (Saxony, Germany) with a PM10 Digitel DHA-80 filter sampler. All samples were taken in 2010 covering a whole annual cycle. The resulting dataset was examined for a possible seasonal dependency of the acid concentrations. Furthermore the influence of the air mass origin on the acid concentrations was studied based on a simple two-sector classification (western or eastern sector) using a back trajectory analysis. Regarding the annual average, adipic acid was found to be the most abundant compound with a mean concentration of 7.8 ng m-3 followed by 4-oxopimelic acid with 6.1 ng m-3. The sum of all acid concentrations showed two maxima during the seasonal cycle; one in summer and one in winter, whereas the highest overall acid concentrations were found in summer. In general the target acids could be divided into two different groups, where one group has its maximum concentration in summer and the other group during winter. The first group contains all investigated aliphatic mono- and dicarboxylic </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70030948','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70030948">Simulation and observations of annual density banding in skeletons of Montastraea (Cnidaria: Scleractinia) growing under thermal stress associated with ocean warming</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Worum, F.P.; Carricart-Ganivet, J. P.; Benson, L.; Golicher, D. 2007-01-01 We present a model of annual density banding in skeletons of Montastraea coral species growing under thermal stress associated with an ocean-warming scenario. The model predicts that at sea-surface temperatures (SSTs) <29??C, high-density bands (HDBs) are formed during the warmest months of the year. As temperature rises and oscillates around the optimal calcification temperature, an annual doublet in the HDB (dHDB) occurs that consists of two narrow HDBs. The presence of such dHDBs in skeletons of Montastraea species is a clear indication of thermal stress. When all monthly SSTs exceed the optimal calcification temperature, HDBs form during the coldest, not the warmest, months of the year. In addition, a decline in mean-annual calcification rate also occurs during this period of elevated SST. A comparison of our model results with annual density patterns observed in skeletons of M. faveolata and M. franksi, collected from several localities in the Mexican Caribbean, indicates that elevated SSTs are already resulting in the presence of dHDBs as a first sign of thermal stress, which occurs even without coral bleaching. ?? 2007, by the American Society of Limnology and Oceanography, Inc. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20070005090','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20070005090">Modeling the Observed Solar Cycle Variations of the Quasi-biennial Oscillation (QBO): Amplification by Wave Forcing</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Mayr, Hans G.; Mengel, John G.; Huang, Frank T.; Chan, Kwing L. 2007-01-01 In several papers, the solar cycle (SC) effect in the lower atmosphere has been linked observationally to the Quasi-biennial Oscillation (QBO) of the zonal circulation, which is generated primarily by small-scale gravity waves (GW). Salby and Callaghan (2000) in particular analyzed the QBO, covering more than 40 years, and discovered that it contains a large SC signature at 20 km. With our Numerical Spectral Model (NSM), we conducted a 3D study to describe the QBO under the influence of the SC, and some results have been published (Mayr et al., GRL, 2005,2006). For a SC period of 10 years, the relative amplitude of radiative forcing is taken to vary exponentially with height, i.e., 0.2% at the surface, 2% at 50 km, 20% at 100 km and above. Applying spectral analysis to filter out and identify the SC signature, the model generates a relatively large modulation of the QBO, which reproduces the observations qualitatively. Our numerical results demonstrate that the modulation of the QBO, with constant phase relative to the SC, persist at least for 60 years. The same model run generates in the seasonal variations a hemispherically symmetric Equatorial Annual Oscillation (EAO, with 12-month period), which is confined to low latitudes like the QBO and is also modulated by the SC. Although the amplitude of the EAO is relatively small, its SC modulation is large, and it is in phase with that of the QBO. The SC modulated EAO is evidently the pathway and pacemaker for the solar influence on the QBO. To shed light on the dynamical processes involved, we present model results that show how the seasonal cycle induces the SC modulations of the EAO and QBO. Our analysis further demonstrates that the SC modulations of the QBO and EAO are amplified by the GW interaction with the flow. The GW momentum source clearly shows a SC modulation that is in phase with the corresponding modulations of the QBO and EAO. By tapping the momentum from the upward propagating GWs, the QBO and EAO </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080015493','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080015493">SABER Observations of the OH Meinel Airglow Variability Near the Mesopause</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Marsh, Daniel R.; Smith, Anne K.; Mlynczak, Martin G. 2005-01-01 The Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument, one of four on board the TIMED satellite, observes the OH Meinel emission at 2.0 m that peaks near the mesopause. The emission results from reactions between members of the oxygen and hydrogen chemical families that can be significantly affected by mesopause dynamics. In this study we compare SABER measurements of OH Meinel emission rates and temperatures with predictions from a 3-dimensional chemical dynamical model. In general, the model is capable of reproducing both the observed diurnal and seasonal OH Meinel emission variability. The results indicate that the diurnal tide has a large effect on the overall magnitude and temporal variation of the emission in low latitudes. This tidal variability is so dominant that the seasonal cycle in the nighttime emission depends very strongly on the local time of the analysis. At higher latitudes, the emission has an annual cycle that is due mainly to transport of oxygen by the seasonally reversing mean circulation. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20030111127&hterms=understand&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dunderstand','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20030111127&hterms=understand&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dunderstand">Using MGS TES Data to Understand Water Cycling in Mars' North Polar Region</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Tamppari, L. K.; Hale, A. S.; Bass, D. S.; Smith, M. D. 2003-01-01 The Martian water cycle is one of the three annual cycles on Mars, dust and CO2 being the other two. Despite the fact that detailed spacecraft data, including global and annual coverage in a variety of wavelengths, have been taken of Mars spanning more than 25 years, there are many outstanding questions regarding the water cycle. There is very little exposed water on Mars today, in either the atmosphere or on the surface although there is geological evidence of catastrophic flooding and continuously running water in past epochs in Mars' history as well as recent (within about 10,000 years ago) evidence for running water in the form of gullies. While there is little water in the atmosphere, water- ice clouds do form and produce seasonal clouds caused by general circulation and by storms. These clouds may in turn be controlling the cycling of the water within the general circulation. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRA..122.2768L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRA..122.2768L">MAVEN observations of the solar cycle 24 space weather conditions at Mars</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Lee, C. O.; Hara, T.; Halekas, J. S.; Thiemann, E.; Chamberlin, P.; Eparvier, F.; Lillis, R. J.; Larson, D. E.; Dunn, P. A.; Espley, J. R.; Gruesbeck, J.; Curry, S. M.; Luhmann, J. G.; Jakosky, B. M. 2017-03-01 The Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft has been continuously observing the variability of solar soft X-rays and EUV irradiance, monitoring the upstream solar wind and interplanetary magnetic field conditions and measuring the fluxes of solar energetic ions and electrons since its arrival to Mars. In this paper, we provide a comprehensive overview of the space weather events observed during the first ˜1.9 years of the science mission, which includes the description of the solar and heliospheric sources of the space weather activity. To illustrate the variety of upstream conditions observed, we characterize a subset of the event periods by describing the Sun-to-Mars details using observations from the MAVEN solar Extreme Ultraviolet Monitor, solar energetic particle (SEP) instrument, Solar Wind Ion Analyzer, and Magnetometer together with solar observations using near-Earth assets and numerical solar wind simulation results from the Wang-Sheeley-Arge-Enlil model for some global context of the event periods. The subset of events includes an extensive period of intense SEP electron particle fluxes triggered by a series of solar flares and coronal mass ejection (CME) activity in December 2014, the impact by a succession of interplanetary CMEs and their associated SEPs in March 2015, and the passage of a strong corotating interaction region (CIR) and arrival of the CIR shock-accelerated energetic particles in June 2015. However, in the context of the weaker heliospheric conditions observed throughout solar cycle 24, these events were moderate in comparison to the stronger storms observed previously at Mars. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26963439','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26963439">Spatial analysis of annual mean stable isotopes in precipitation across Japan based on an intensive observation period throughout 2013.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Ichiyanagi, Kimpei; Tanoue, Masahiro 2016-01-01 Spatial distribution of annual mean stable isotopes in precipitation (δ(18)O, δ(2)H) was observed at 56 sites across Japan throughout 2013. Annual mean δ(18)O values showed a strong latitude effect, from -12.4 ‰ in the north to -5.1 ‰ in the south. Annual mean d-excess values ranged from 8 to 21 ‰, and values on the Sea of Japan side in Northern and Eastern Japan were relatively higher than those on the Pacific Ocean side. The local meteoric water line (LMWL) and isotope effects were based on the annual mean values from all sites across Japan as divided into distinct regions: the Sea of Japan side to the Pacific Ocean side and Northeastern to Southwestern Japan. Slopes and intercepts of LMWL ranged from 7.4 to 7.8 and 9.8 to 13.0, respectively. Slopes for latitude, altitude, and temperature effects ranged from -0.27 to -0.48 ‰/°N, -0.0034 to -0.0053 ‰/m, and 0.36 to 0.46 ‰/°C, respectively, with statistically significance at the 99 % level. However, there was no precipitation amount effect. From the result of a multiple regression analysis, the empirical formula of annual mean δ(18)O in precipitation from latitude and altitude for all sites across Japan was determined to be δ(18) O = -0.348 (LAT) - 0.00307 (ALT) + 4.29 (R(2) = 0.59). Slopes for latitude and altitude ranged from - 0.28 to - 0.51, and - 0.0019 to - 0.0045, respectively. Even though site distribution was uneven, these equations are the first trial estimation for annual mean stable isotopes in precipitation across Japan. Further research performed on the monthly basis is required to elucidate factors controlling the spatiotemporal variability of stable isotopes in precipitation across Japan. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040082148','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040082148">Global Changes of the Water Cycle Intensity</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Bosilovich, Michael G.; Schubert, Siegfried D.; Walker, Gregory K. 2003-01-01 In this study, we evaluate numerical simulations of the twentieth century climate, focusing on the changes in the intensity of the global water cycle. A new diagnostic of atmospheric water vapor cycling rate is developed and employed, that relies on constituent tracers predicted at the model time step. This diagnostic is compared to a simplified traditional calculation of cycling rate, based on monthly averages of precipitation and total water content. The mean sensitivity of both diagnostics to variations in climate forcing is comparable. However, the new diagnostic produces systematically larger values and more variability than the traditional average approach. Climate simulations were performed using SSTs of the early (1902-1921) and late (1979- 1998) twentieth century along with the appropriate C02 forcing. In general, the increase of global precipitation with the increases in SST that occurred between the early and late twentieth century is small. However, an increase of atmospheric temperature leads to a systematic increase in total precipitable water. As a result, the residence time of water in the atmosphere increased, indicating a reduction of the global cycling rate. This result was explored further using a number of 50-year climate simulations from different models forced with observed SST. The anomalies and trends in the cycling rate and hydrologic variables of different GCMs are remarkably similar. The global annual anomalies of precipitation show a significant upward trend related to the upward trend of surface temperature, during the latter half of the twentieth century. While this implies an increase in the hydrologic cycle intensity, a concomitant increase of total precipitable water again leads to a decrease in the calculated global cycling rate. An analysis of the land/sea differences shows that the simulated precipitation over land has a decreasing trend while the oceanic precipitation has an upward trend consistent with previous studies and the </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22690675','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22690675">Comparing sex steroid levels during the annual cycles of rainbow trout (Oncorhynchus mykiss) diploid female (XX) and triploid female (XXX) genotypic sex.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Espinosa, E; Josa, A; Gil, L; Malo, C; Mitjana, O 2013-02-01 In this study, the annual cycle of the gonadal steroids testosterone (T), 11-ketotestosterone (11-KT), 17β-estradiol (E2) and 17α, 20β-dihydroxy-4-pregnen-3-one (DHP) was determined using radioimmunoassay and then compared for two populations of rainbow trout, XX diploid females (n = 40) and XXX triploid females (n = 15). In females, E2 and DHP levels were found to be significantly related to body weight (r = 0.22513; p < 0.0001 and r = 0.15831; p > 0.001, respectively). In this group, E2 concentrations peaked in November (25.05 ng/ml), while maximum DHP levels, only measurable from October to April, were attained in February (64.14 ng/ml). No significant differences in hormone ranges related to egg output ability were observed. Finally, sex steroid concentrations were low in the triploid female XXX fish compared to the female XX population. Nevertheless, maximum T (33.85 ng/ml) and 11-KT (32.35 ng/ml) levels were recorded in January, for XXX. The levels for these two hormones are relatively high and are also significantly associated (r = 0.8430; p < 0.0001). Diploid females showed significantly higher levels of E2 than triploids over the 12-month study period. The female triploid fish produced the lowest steroid hormone levels, such that these would be the most suitable for human consumption. © 2012 Blackwell Verlag GmbH. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2148366','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2148366">Observational evidence for volcanic impact on sea level and the global water cycle</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> Grinsted, A.; Moore, J. C.; Jevrejeva, S. 2007-01-01 It has previously been noted that there are drops in global sea level (GSL) after some major volcanic eruptions. However, observational evidence has not been convincing because there is substantial variability in the global sea level record over periods similar to those at which we expect volcanoes to have an impact. To quantify the impact of volcanic eruptions we average monthly GSL data from 830 tide gauge records around five major volcanic eruptions. Surprisingly, we find that the initial response to a volcanic eruption is a significant rise in sea level of 9 ± 3 mm in the first year after the eruption. This rise is followed by a drop of 7 ± 3 mm in the period 2–3 years after the eruption relative to preeruption sea level. These results are statistically robust and no particular volcanic eruption or ocean region dominates the signature we find. Neither the drop nor especially the rise in GSL can be explained by models of lower oceanic heat content. We suggest that the mechanism is a transient disturbance of the water cycle with a delayed response of land river runoff relative to ocean evaporation and global precipitation that affects global sea level. The volcanic impact on the water cycle and sea levels is comparable in magnitude to that of a large El Niño–La Niña cycle, amounting to ≈5% of global land precipitation. PMID:18056644 </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active">15</li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active">16</li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18056644','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18056644">Observational evidence for volcanic impact on sea level and the global water cycle.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Grinsted, A; Moore, J C; Jevrejeva, S 2007-12-11 It has previously been noted that there are drops in global sea level (GSL) after some major volcanic eruptions. However, observational evidence has not been convincing because there is substantial variability in the global sea level record over periods similar to those at which we expect volcanoes to have an impact. To quantify the impact of volcanic eruptions we average monthly GSL data from 830 tide gauge records around five major volcanic eruptions. Surprisingly, we find that the initial response to a volcanic eruption is a significant rise in sea level of 9 +/- 3 mm in the first year after the eruption. This rise is followed by a drop of 7 +/- 3 mm in the period 2-3 years after the eruption relative to preeruption sea level. These results are statistically robust and no particular volcanic eruption or ocean region dominates the signature we find. Neither the drop nor especially the rise in GSL can be explained by models of lower oceanic heat content. We suggest that the mechanism is a transient disturbance of the water cycle with a delayed response of land river runoff relative to ocean evaporation and global precipitation that affects global sea level. The volcanic impact on the water cycle and sea levels is comparable in magnitude to that of a large El Niño-La Niña cycle, amounting to approximately 5% of global land precipitation. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70193280','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70193280">Drivers and environmental responses to the changing annual snow cycle of northern Alaska</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Cox, Christopher J.; Stone, Robert S.; Douglas, David C.; Stanitski, Diane; Divoky, George J.; Dutton, Geoff S.; Sweeney, Colm; George, J. Craig; Longenecker, David U. 2017-01-01 On the North Slope of Alaska, earlier spring snowmelt and later onset of autumn snow accumulation are tied to atmospheric dynamics and sea ice conditions, and result in environmental responses.Linkages between atmospheric, ecological and biogeochemical variables in the changing Arctic are analyzed using long-term measurements near Utqiaġvik (formerly Barrow), Alaska. Two key variables are the date when snow disappears in spring, as determined primarily by atmospheric dynamics, precipitation, air temperature, winter snow accumulation and cloud cover, as well as the date of onset of snowpack in autumn that is additionally influenced by ocean temperature and sea ice extent. In 2015 and 2016 the snow melted early at Utqiaġvik due mainly to anomalous warmth during May of both years attributed to atmospheric circulation patterns, with 2016 having the record earliest snowmelt. These years are discussed in the context of a 115-year snowmelt record at Utqiaġvik with a trend toward earlier melting since the mid- 1970s (-2.86 days/decade, 1975-2016). At nearby Cooper Island, where a colony of seabirds, Black Guillemots, have been monitored since 1975, timing of egg laying is correlated with Utqiaġvik snowmelt with 2015 and 2016 being the earliest years in the 42-year record. Ice-out at a nearby freshwater lagoon is also correlated with Utqiaġvik snowmelt. The date when snow begins to accumulate in autumn at Utqiaġvik shows a trend towards later dates (+4.6 days/decade, 1975-2016), with 2016 the latest on record. The relationships between the lengthening snow-free season and regional phenology, soil temperatures, fluxes of gases from the tundra, and to regional sea ice conditions are discussed. Better understanding of these interactions is needed to predict the annual snow cycles in the region at seasonal to decadal scales, and to anticipate coupled environmental responses. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007JGRD..112.6308G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007JGRD..112.6308G">Observations of 1,1-difluoroethane (HFC-152a) at AGAGE and SOGE monitoring stations in 1994-2004 and derived global and regional emission estimates</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Greally, B. R.; Manning, A. J.; Reimann, S.; McCulloch, A.; Huang, J.; Dunse, B. L.; Simmonds, P. G.; Prinn, R. G.; Fraser, P. J.; Cunnold, D. M.; O'Doherty, S.; Porter, L. W.; Stemmler, K.; Vollmer, M. K.; Lunder, C. R.; Schmidbauer, N.; Hermansen, O.; Arduini, J.; Salameh, P. K.; Krummel, P. B.; Wang, R. H. J.; Folini, D.; Weiss, R. F.; Maione, M.; Nickless, G.; Stordal, F.; Derwent, R. G. 2007-03-01 Ground-based in situ measurements of 1,1-difluoroethane (HFC-152a, CH3CHF2) which is regulated under the Kyoto Protocol are reported under the auspices of the AGAGE (Advanced Global Atmospheric Gases Experiment) and SOGE (System of Observation of halogenated Greenhouse gases in Europe) programs. Observations of HFC-152a at five locations (four European and one Australian) over a 10 year period were recorded. The annual average growth rate of HFC-152a in the midlatitude Northern Hemisphere has risen from 0.11 ppt/yr to 0.6 ppt/yr from 1994 to 2004. The Southern Hemisphere annual average growth rate has risen from 0.09 ppt/yr to 0.4 ppt/yr from 1998 to 2004. The 2004 average mixing ratio for HFC-152a was 5.0 ppt and 1.8 ppt in the Northern and Southern hemispheres, respectively. The annual cycle observed for this species in both hemispheres is approximately consistent with measured annual cycles at the same locations in other gases which are destroyed by OH. Yearly global emissions of HFC-152a from 1994 to 2004 are derived using the global mean HFC-152a observations and a 12-box 2-D model. The global emission of HFC-152a has risen from 7 Kt/yr to 28 Kt/yr from 1995 to 2004. On the basis of observations of above-baseline elevations in the HFC-152a record and a consumption model, regional emission estimates for Europe and Australia are calculated, indicating accelerating emissions from Europe since 2000. The overall European emission in 2004 ranges from 1.5 to 4.0 Kt/year, 5-15% of global emissions for 1,1-difluoroethane, while the Australian contribution is negligible at 5-10 tonnes/year, <0.05% of global emissions. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018FrASS...5...17M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018FrASS...5...17M">Observational Evidence of Shallow Origins for the Magnetic Fields of Solar Cycles - a review</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Martin, Sara F. 2018-05-01 Observational evidence for the origin of active region magnetic fields has been sought from published information on extended solar cycles, statistical distributions of active regions and ephemeral regions, helioseismology results, positional relationships to supergranules, and fine-scale magnetic structure of active regions and their sunspots during their growth. Statistical distributions of areas of ephemeral and active regions blend together to reveal a single power law. The shape of the size distribution in latitude of all active regions is independent of time during the solar cycle, yielding further evidence that active regions of all sizes belong to the same population. Elementary bipoles, identified also by other names, appear to be the building blocks of active regions; sunspots form from elementary bipoles and are therefore deduced to develop from the photosphere downward, consistent with helioseismic detection of downflows to 3-4 Mm below sunspots as well as long-observed downflows from chromospheric/coronal arch filaments into sunspots from their earliest appearance. Time-distance helioseismology has been effective in revealing flows related to sunspots to depths of 20 Mm. Ring diagram analysis shows a statistically significant preference for upflows to precede major active region emergence and downflows after flux emergence but both are often observed together or sometimes not detected. From deep-focus helioseismic techniques for seeking magnetic flux below the photosphere prior major active regions, there is evidence of acoustic travel-time perturbation signatures rising in the limited range of depths of 42-75 Mm but these have not been verified or found at more shallow depths by helioseismic holographic techniques. The development of active regions from clusters of elementary bipoles appears to be the same irrespective of how much flux an active region eventually develops. This property would be consistent with the magnetic fields of large active </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20070031229&hterms=Qbo&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DQbo','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20070031229&hterms=Qbo&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DQbo">QBO as Potential Amplifier of Solar Cycle Influence</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Mayr, Hans G.; Mangel, John G.; Wolff, Charles L.; Porter, Hayden S. 2006-01-01 The solar cycle (SC) effect in the lower atmosphere has been linked observationally to the quasi-biennial oscillation (QBO) of the zonal circulation. Salby and Callaghan (2000) in particular analyzed the QBO covering more than 40 years and found that it contains a large SC signature at 20 km. We discuss a 3D study in which we simulate the QBO under the influence of the SC. For a SC period of 10 years, the relative amplitude of radiative forcing is taken to vary with height: 0.2% (surface), 2% (50 km), 20% (100 km and above). This model produces in the lower stratosphere a relatively large modulation of the QBO, which appears to come from the SC and qualitatively agrees with the observations. The modulation of the QBO, with constant phase relative to the SC, is shown to persist at least for 50 years, and it is induced by a SC modulated annual oscillation that is hemispherically symmetric and confined to low latitudes. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21930369','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21930369">Internal cycle modeling and environmental assessment of multiple cycle consumer products.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Tsiliyannis, C A 2012-01-01 Dynamic annual flow models incorporating consumer discard and usage loss and featuring deterministic and stochastic end-of-cycle (EOC) return by the consumer are developed for reused or remanufactured products (multiple cycle products, MCPs), including fast and slow cycling, short and long-lived products. It is shown that internal flows (reuse and overall consumption) increase proportionally to the dimensionless internal cycle factor (ICF) which is related to environmental impact reduction factors. The combined reuse/recycle (or cycle) rate is shown capable for shortcut, albeit effective, monitoring of environmental performance in terms of waste production, virgin material extraction and manufacturing impacts of all MCPs, a task, which physical variables (lifetime, cycling frequency, mean or total number of return trips) and conventional rates, via which environmental policy has been officially implemented (e.g. recycling rate) cannot accomplish. The cycle rate is shown to be an increasing (hyperbolic) function of ICF. The impact of the stochastic EOC return characteristics on total reuse and consumption flows, as well as on eco-performance, is assessed: symmetric EOC return has a small, positive effect on performance compared to deterministic, while early shifted EOC return is more beneficial. In order to be efficient, environmental policy should set higher minimum reuse targets for higher trippage MCPs. The results may serve for monitoring, flow accounting and comparative eco-assessment of MCPs. They may be useful in identifying reachable and efficient reuse/recycle targets for consumer products and in planning return via appropriate labelling and digital coding for enhancing environmental performance, while satisfying consumer demand. Copyright Â© 2011 Elsevier Ltd. All rights reserved. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMSH31B2730P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMSH31B2730P">Solar Energetic Particle Composition over Two Solar Cycles as Observed by the Ulysses/HISCALE and ACE/EPAM Pulse Height Analyzers.</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Patterson, J. D.; Madanian, H.; Manweiler, J. W.; Lanzerotti, L. J. 2017-12-01 We present the compositional variation in the Solar Energetic Particle (SEP) population in the inner heliosphere over two solar cycles using data from the Ulysses Heliospheric Instrument for Spectra, Composition, and Anisotropy at Low Energies (HISCALE) and Advanced Composition Explorer (ACE) Electron Proton Alpha Monitor (EPAM). The Ulysses mission was active from late 1990 to mid-2009 in a heliopolar orbit inclined by 80° with a perihelion of 1.3 AU and an aphelion of 5.4 AU. The ACE mission has been active since its launch in late 1997 and is in a halo orbit about L1. These two missions provide a total of 27 years of continuous observation in the inner heliosphere with twelve years of simultaneous observation. HISCALE and EPAM data provide species-resolved differential flux and density of SEP between 0.5-5 MeV/nuc. Several ion species (He, C, O, Ne, Si, Fe) are identified using the Pulse Height Analyzer (PHA) system of the Composition Aperture for both instruments. The He density shows a noticeable increase at high solar activity followed by a moderate drop at the quiet time of the solar minimum between cycles 23 and 24. The density of heavier ions (i.e. O and Fe) change minimally with respect to the F10.7 index variations however, certain energy-specific count rates decrease during solar minimum. With Ulysses and ACE observing in different regions of the inner heliosphere, there are significant latitudinal differences in how the O/He ratios vary with the solar cycle. At solar minimum, there is reasonable agreement between the observations from both instruments. At solar max 23, the differences in composition over the course of the solar cycle, and as observed at different heliospheric locations can provide insight to the origins of and acceleration processes differentially affecting solar energetic ions. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3743065','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3743065">Environmental impacts on the diversity of methane-cycling microbes and their resultant function</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> Aronson, Emma L.; Allison, Steven D.; Helliker, Brent R. 2013-01-01 Methane is an important anthropogenic greenhouse gas that is produced and consumed in soils by microorganisms responding to micro-environmental conditions. Current estimates show that soil consumption accounts for 5–15% of methane removed from the atmosphere on an annual basis. Recent variability in atmospheric methane concentrations has called into question the reliability of estimates of methane consumption and calls for novel approaches in order to predict future atmospheric methane trends. This review synthesizes the environmental and climatic factors influencing the consumption of methane from the atmosphere by non-wetland, terrestrial soil microorganisms. In particular, we focus on published efforts to connect community composition and diversity of methane-cycling microbial communities to observed rates of methane flux. We find abundant evidence for direct connections between shifts in the methane-cycling microbial community, due to climate and environmental changes, and observed methane flux levels. These responses vary by ecosystem and associated vegetation type. This information will be useful in process-based models of ecosystem methane flux responses to shifts in environmental and climatic parameters. PMID:23966984 </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017Icar..291...82P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017Icar..291...82P">Unraveling the martian water cycle with high-resolution global climate simulations</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Pottier, Alizée; Forget, François; Montmessin, Franck; Navarro, Thomas; Spiga, Aymeric; Millour, Ehouarn; Szantai, André; Madeleine, Jean-Baptiste 2017-07-01 Global climate modeling of the Mars water cycle is usually performed at relatively coarse resolution (200 - 300km), which may not be sufficient to properly represent the impact of waves, fronts, topography effects on the detailed structure of clouds and surface ice deposits. Here, we present new numerical simulations of the annual water cycle performed at a resolution of 1° × 1° (∼ 60 km in latitude). The model includes the radiative effects of clouds, whose influence on the thermal structure and atmospheric dynamics is significant, thus we also examine simulations with inactive clouds to distinguish the direct impact of resolution on circulation and winds from the indirect impact of resolution via water ice clouds. To first order, we find that the high resolution does not dramatically change the behavior of the system, and that simulations performed at ∼ 200 km resolution capture well the behavior of the simulated water cycle and Mars climate. Nevertheless, a detailed comparison between high and low resolution simulations, with reference to observations, reveal several significant changes that impact our understanding of the water cycle active today on Mars. The key northern cap edge dynamics are affected by an increase in baroclinic wave strength, with a complication of northern summer dynamics. South polar frost deposition is modified, with a westward longitudinal shift, since southern dynamics are also influenced. Baroclinic wave mode transitions are observed. New transient phenomena appear, like spiral and streak clouds, already documented in the observations. Atmospheric circulation cells in the polar region exhibit a large variability and are fine structured, with slope winds. Most modeled phenomena affected by high resolution give a picture of a more turbulent planet, inducing further variability. This is challenging for long-period climate studies. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.B43I..07B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.B43I..07B">The role of ecosystem memory in predicting inter-annual variations of the tropical carbon balance.</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Bloom, A. A.; Liu, J.; Bowman, K. W.; Konings, A. G.; Saatchi, S.; Worden, J. R.; Worden, H. M.; Jiang, Z.; Parazoo, N.; Williams, M. D.; Schimel, D. 2017-12-01 Understanding the trajectory of the tropical carbon balance remains challenging, in part due to large uncertainties in the integrated response of carbon cycle processes to climate variability. Satellite observations atmospheric CO2 from GOSAT and OCO-2, together with ancillary satellite measurements, provide crucial constraints on continental-scale terrestrial carbon fluxes. However, an integrated understanding of both climate forcings and legacy effects (or "ecosystem memory") on the terrestrial carbon balance is ultimately needed to reduce uncertainty on its future trajectory. Here we use the CARbon DAta-MOdel fraMework (CARDAMOM) diagnostic model-data fusion approach - constrained by an array of C cycle satellite surface observations, including MODIS leaf area, biomass, GOSAT solar-induced fluorescence, as well as "top-down" atmospheric inversion estimates of CO2 and CO surface fluxes from the NASA Carbon Monitoring System Flux (CMS-Flux) - to constrain and predict spatially-explicit tropical carbon state variables during 2010-2015. We find that the combined assimilation of land surface and atmospheric datasets places key constraints on the temperature sensitivity and first order carbon-water feedbacks throughout the tropics and combustion factors within biomass burning regions. By varying the duration of the assimilation period, we find that the prediction skill on inter-annual net biospheric exchange is primarily limited by record length rather than model structure and process representation. We show that across all tropical biomes, quantitative knowledge of memory effects - which account for 30-50% of interannual variations across the tropics - is critical for understanding and ultimately predicting the inter-annual tropical carbon balance. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22654320-solar-cycle-another-moderate-cycle','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22654320-solar-cycle-another-moderate-cycle">SOLAR CYCLE 25: ANOTHER MODERATE CYCLE?</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Cameron, R. H.; Schüssler, M.; Jiang, J., E-mail: cameron@mps.mpg.de 2016-06-01 Surface flux transport simulations for the descending phase of Cycle 24 using random sources (emerging bipolar magnetic regions) with empirically determined scatter of their properties provide a prediction of the axial dipole moment during the upcoming activity minimum together with a realistic uncertainty range. The expectation value for the dipole moment around 2020 (2.5 ± 1.1 G) is comparable to that observed at the end of Cycle 23 (about 2 G). The empirical correlation between the dipole moment during solar minimum and the strength of the subsequent cycle thus suggests that Cycle 25 will be of moderate amplitude, not muchmore » higher than that of the current cycle. However, the intrinsic uncertainty of such predictions resulting from the random scatter of the source properties is considerable and fundamentally limits the reliability with which such predictions can be made before activity minimum is reached.« less </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20130013047','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20130013047">Diary of a Wimpy Cycle</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Hathaway, David; Upton, Lisa 2013-01-01 The cause of the low and extended minimum in solar activity between Sunspot Cycles 23 and 24 was the small size of Sunspot Cycle 24 itself - small cycles start late and leave behind low minima. Cycle 24 is small because the polar fields produced during Cycle 23 were substantially weaker than those produced during the previous cycles and those (weak) polar fields are the seeds for the activity of the following cycle. Here we discuss the observed characteristics of Cycle 24 and contrast them to the characteristics of previous cycles. We present observations and Magnetic Flux Transport simulations with data assimilated from SOHO/MDI and SDO/HMI that help to explain these differences and point the way to predictions of future activity levels. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140017194','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140017194">Trend Change Detection in NDVI Time Series: Effects of Inter-Annual Variability and Methodology</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Forkel, Matthias; Carvalhais, Nuno; Verbesselt, Jan; Mahecha, Miguel D.; Neigh, Christopher S.R.; Reichstein, Markus 2013-01-01 Changing trends in ecosystem productivity can be quantified using satellite observations of Normalized Difference Vegetation Index (NDVI). However, the estimation of trends from NDVI time series differs substantially depending on analyzed satellite dataset, the corresponding spatiotemporal resolution, and the applied statistical method. Here we compare the performance of a wide range of trend estimation methods and demonstrate that performance decreases with increasing inter-annual variability in the NDVI time series. Trend slope estimates based on annual aggregated time series or based on a seasonal-trend model show better performances than methods that remove the seasonal cycle of the time series. A breakpoint detection analysis reveals that an overestimation of breakpoints in NDVI trends can result in wrong or even opposite trend estimates. Based on our results, we give practical recommendations for the application of trend methods on long-term NDVI time series. Particularly, we apply and compare different methods on NDVI time series in Alaska, where both greening and browning trends have been previously observed. Here, the multi-method uncertainty of NDVI trends is quantified through the application of the different trend estimation methods. Our results indicate that greening NDVI trends in Alaska are more spatially and temporally prevalent than browning trends. We also show that detected breakpoints in NDVI trends tend to coincide with large fires. Overall, our analyses demonstrate that seasonal trend methods need to be improved against inter-annual variability to quantify changing trends in ecosystem productivity with higher accuracy. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSOD21A..03E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSOD21A..03E">Spatiotemporal Variability in Particulate Organic Carbon Export Observed Using Bio-Optical Profiling Floats</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Estapa, M. L. 2016-02-01 Autonomous, bio-optical profiling floats are poised to broaden the number and spatiotemporal resolution of observations of the ocean's biological pump. Here, we used multiple optical sensors aboard two bio-optical profiling floats (Navis BGCi, Sea-Bird) deployed in the Sargasso Sea to derive in situ proxies for particulate carbon (PC) flux, sub-mixed layer net community production (NCP) and to drive a model of net primary production (NPP). Profiles were collected at approximately 2-day resolution, and drift-phase PC flux observations were collected at subdaily resolution at a rotating cycle of observation depths between 150 and 1000 m. The magnitudes of NPP, PC flux, and their annually-averaged ratio were generally consistent with observations at the nearby Bermuda Atlantic Timeseries Study (BATS) site. PC flux and the export ratio were enhanced in the autumn as well as in the spring, and varied over short timescales possibly due to the influence of mesoscale eddies. The relatively shallow park depths and short profile cycle lengths allow us to identify ephemeral, subsurface bio-optical features and compare them to measured fluxes and satellite-observed surface properties. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25985681','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25985681">[Nitrogen and water cycling of typical cropland in the North China Plain].</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Pei, Hong-wei; Shen, Yan-jun; Liu, Chang-ming 2015-01-01 Intensive fertilization and irrigation associated increasing grain production has led to serious groundwater depletion and soil/water pollution in the North China Plain (NCP). Intensive agriculture changes the initial mass and energy balance, and also results in huge risks to the water/soil resources and food security regionally. Based on the research reports on the nitrogen cycle and water cycle in typical cropland (winter wheat and summer corn) in the NCP during the past 20 years, and the meteorological data, field experiments and surveys, we calculated the nitrogen cycle and water-cycle for this typical cropland. Annual total nitrogen input were 632 kg N . hm-2, including 523 kg N . hm-2 from commercial fertilizer, 74 kg N . hm-2 from manure, 23 kg N . hm-2 from atmosphere, and 12 kg N . hm-2 from irrigation. All of annual outputs summed to 532 kg N . hm-2 including 289 kg N . hm-2 for crop, 77 kg N . hm-2 staying in soil profile, leaching 104 kg N . hm-2, 52 kg N . hm-2 for ammonia volatilization, 10 kg N . hm-2 loss in nitrification and denitrification. Uncertainties of the individual cases and the summary process lead to the unbalance of nitrogen. For the dominant parts of the field water cycle, annual precipitation was 557 mm, irrigation was 340 mm, while 762 mm was for evapotranspiration and 135 mm was for deep percolation. Considering uncertainties in the nitrogen and water cycles, coupled experiments based on multi-disciplines would be useful for understanding mechanisms for nitrogen and water transfer processes in the soil-plant-atmosphere-continuum (SPAC) , and the interaction between nitrogen and water, as well as determining the critical threshold values for sustainability of soil and water resources in the NCP. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018SoPh..293...84A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018SoPh..293...84A">The 2015 Summer Solstice Storm: One of the Major Geomagnetic Storms of Solar Cycle 24 Observed at Ground Level</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Augusto, C. R. A.; Navia, C. E.; de Oliveira, M. N.; Nepomuceno, A. A.; Raulin, J. P.; Tueros, E.; de Mendonça, R. R. S.; Fauth, A. C.; Vieira de Souza, H.; Kopenkin, V.; Sinzi, T. 2018-05-01 We report on the 22 - 23 June 2015 geomagnetic storm that occurred at the summer solstice. There have been fewer intense geomagnetic storms during the current solar cycle, Solar Cycle 24, than in the previous cycle. This situation changed after mid-June 2015, when one of the largest solar active regions (AR 12371) of Solar Cycle 24 that was located close to the central meridian, produced several coronal mass ejections (CMEs) associated with M-class flares. The impact of these CMEs on the Earth's magnetosphere resulted in a moderate to severe G4-class geomagnetic storm on 22 - 23 June 2015 and a G2 (moderate) geomagnetic storm on 24 June. The G4 solstice storm was the second largest (so far) geomagnetic storm of Cycle 24. We highlight the ground-level observations made with the New-Tupi, Muonca, and the CARPET El Leoncito cosmic-ray detectors that are located within the South Atlantic Anomaly (SAA) region. These observations are studied in correlation with data obtained by space-borne detectors (ACE, GOES, SDO, and SOHO) and other ground-based experiments. The CME designations are taken from the Computer Aided CME Tracking (CACTus) automated catalog. As expected, Forbush decreases (FD) associated with the passing CMEs were recorded by these detectors. We note a peculiar feature linked to a severe geomagnetic storm event. The 21 June 2015 CME 0091 (CACTus CME catalog number) was likely associated with the 22 June summer solstice FD event. The angular width of CME 0091 was very narrow and measured {˜} 56° degrees seen from Earth. In most cases, only CME halos and partial halos lead to severe geomagnetic storms. We perform a cross-check analysis of the FD events detected during the rise phase of Solar Cycle 24, the geomagnetic parameters, and the CACTus CME catalog. Our study suggests that narrow angular-width CMEs that erupt in a westward direction from the Sun-Earth line can lead to moderate and severe geomagnetic storms. We also report on the strong solar proton </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AcO....35..685G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AcO....35..685G">Intra-annual variation in habitat choice by an endemic woodpecker: Implications for forest management and conservation</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Garcia-del-Rey, Eduardo; Fernández-Palacios, José María; Muñoz, Pascual Gil 2009-09-01 The Canary Islands great spotted woodpecker Dendrocopos major canariensis is an endemic bird restricted to the Pinus canariensis forests of Tenerife and Gran Canaria. Classification tree models were applied to explore the relationship of the occurrence of this picid and habitat variables between two contrasting periods (breeding vs. non-breeding seasons) and for the entire annual cycle. During the reproductive period the availability of mature trees (DBH > 60 cm), and snags (dead trees), for nesting and roosting, characterize the breeding territory. Outside the breeding season the choice of locations was driven by a tree cover larger than 28.5% and the presence of trees taller than 8.5 m on average, a pattern explained by the availability of pine seeds in the cones of well-developed canopies, and less so by predation risk. Overall, during the annual cycle, well-developed canopy sites influenced the presence of this picidae (tree cover > 38%) and on more open sites (<38%) the presence of mature trees (DBH> 60 cm) became the second most important predictor of occurrence. We suggest that food abundance and availability could be the ultimate factor explaining the intra-annual variation observed, with the availability of snags being an important factor during nesting. In the range of this endemic, we recommend selective cuts in pine plantations, to allow the trees to set seed and improve their crops, minimizing the elimination of snags, and killing some large pine trees if the priority is to expand the distributional range of the woodpecker. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950031248&hterms=balance+general&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dbalance%2Bgeneral','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950031248&hterms=balance+general&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dbalance%2Bgeneral">Climatology and natural variability of the global hydrologic cycle in the GLA atmospheric general circulation model</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Lau, K.-M.; Mehta, V. M.; Sud, Y. C.; Walker, G. K. 1994-01-01 Time average climatology and low-frequency variabilities of the global hydrologic cycle (GHC) in the Goddard Laboratory for Atmospheres (GLA) general circulation model (GCM) were investigated in the present work. A 730-day experiment was conducted with the GLA GCM forced by insolation, sea surface temperature, and ice-snow undergoing climatological annual cycles. Ifluences of interactive soil moisture on time average climatology and natural variability of the GHC were also investigated by conducting 365-day experiments with and without interactive soil moisture. Insolation, sea surface temperature, and ice-snow were fixed at their July levels in the latter two experiments. Results show that the model's time average hydrologic cycle variables for July in all three experiments agree reasonably well with observations. Except in the case of precipitable water, the zonal average climates of the annual cycle experiment and the two perpetual July experiments are alike, i.e., their differences are within limits of the natural variability of the model's climate. Statistics of various components of the GHC, i.e., water vapor, evaporation, and precipitation, are significantly affected by the presence of interactive soil moisture. A long-term trend is found in the principal empirical modes of variability of ground wetness, evaporation, and sensible heat. Dominant modes of variability of these quantities over land are physically consistent with one another and with land surface energy balance requirements. The dominant mode of precipitation variability is found to be closely related to organized convection over the tropical western Pacific Ocean. The precipitation variability has timescales in the range of 2 to 3 months and can be identified with the stationary component of the Madden-Julian Oscillation. The precipitation mode is not sensitive to the presence of interactive soil moisture but is closely linked to both the rotational and divergent components of atmospheric </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AIPC.1850j0002B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AIPC.1850j0002B">Solar hydrogen production with cerium oxides thermochemical cycle</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Binotti, Marco; Di Marcoberardino, Gioele; Biassoni, Mauro; Manzolini, Giampaolo 2017-06-01 This paper discusses the hydrogen production using a solar driven thermochemical cycle. The thermochemical cycle is based on nonstoichiometric cerium oxides redox and the solar concentration system is a solar dish. Detailed optical and redox models were developed to optimize the hydrogen production performance as function of several design parameters (i.e. concentration ratio, reactor pressures and temperatures) The efficiency of the considered technology is compared against two commercially available technologies namely PV + electrolyzer and Dish Stirling + electrolyzer. Results show that solar-to-fuel efficiency of 21.2% can be achieved at design condition assuming a concentration ratio around 5000, reduction and oxidation temperatures of 1500°C and 1275 °C. When moving to annual performance, the annual yield of the considered approach can be as high as 16.7% which is about 43% higher than the best competitive technology. The higher performance implies that higher installation costs around 40% can be accepted for the innovative concept to achieve the same cost of hydrogen. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SpWea..15..589M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SpWea..15..589M">Cosmic ray modulation and radiation dose of aircrews during the solar cycle 24/25</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Miyake, Shoko; Kataoka, Ryuho; Sato, Tatsuhiko 2017-04-01 Weak solar activity and high cosmic ray flux during the coming solar cycle are qualitatively anticipated by the recent observations that show the decline in the solar activity levels. We predict the cosmic ray modulation and resultant radiation exposure at flight altitude by using the time-dependent and three-dimensional model of the cosmic ray modulation. Our galactic cosmic ray (GCR) model is based on the variations of the solar wind speed, the strength of the heliospheric magnetic field, and the tilt angle of the heliospheric current sheet. We reproduce the 22 year variation of the cosmic ray modulation from 1980 to 2015 taking into account the gradient-curvature drift motion of GCRs. The energy spectra of GCR protons obtained by our model show good agreement with the observations by the Balloon-borne Experiment with a Superconducting magnetic rigidity Spectrometer (BESS) and the Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA) except for a discrepancy at the solar maximum. Five-year annual radiation dose around the solar minimum at the solar cycle 24/25 will be approximately 19% higher than that in the last cycle. This is caused by the charge sign dependence of the cosmic ray modulation, such as the flattop profiles in a positive polarity. </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active">16</li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active">17</li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014BGeo...11.3547C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014BGeo...11.3547C">Current systematic carbon-cycle observations and the need for implementing a policy-relevant carbon observing system</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Ciais, P.; Dolman, A. J.; Bombelli, A.; Duren, R.; Peregon, A.; Rayner, P. J.; Miller, C.; Gobron, N.; Kinderman, G.; Marland, G.; Gruber, N.; Chevallier, F.; Andres, R. J.; Balsamo, G.; Bopp, L.; Bréon, F.-M.; Broquet, G.; Dargaville, R.; Battin, T. J.; Borges, A.; Bovensmann, H.; Buchwitz, M.; Butler, J.; Canadell, J. G.; Cook, R. B.; DeFries, R.; Engelen, R.; Gurney, K. R.; Heinze, C.; Heimann, M.; Held, A.; Henry, M.; Law, B.; Luyssaert, S.; Miller, J.; Moriyama, T.; Moulin, C.; Myneni, R. B.; Nussli, C.; Obersteiner, M.; Ojima, D.; Pan, Y.; Paris, J.-D.; Piao, S. L.; Poulter, B.; Plummer, S.; Quegan, S.; Raymond, P.; Reichstein, M.; Rivier, L.; Sabine, C.; Schimel, D.; Tarasova, O.; Valentini, R.; Wang, R.; van der Werf, G.; Wickland, D.; Williams, M.; Zehner, C. 2014-07-01 A globally integrated carbon observation and analysis system is needed to improve the fundamental understanding of the global carbon cycle, to improve our ability to project future changes, and to verify the effectiveness of policies aiming to reduce greenhouse gas emissions and increase carbon sequestration. Building an integrated carbon observation system requires transformational advances from the existing sparse, exploratory framework towards a dense, robust, and sustained system in all components: anthropogenic emissions, the atmosphere, the ocean, and the terrestrial biosphere. The paper is addressed to scientists, policymakers, and funding agencies who need to have a global picture of the current state of the (diverse) carbon observations. We identify the current state of carbon observations, and the needs and notional requirements for a global integrated carbon observation system that can be built in the next decade. A key conclusion is the substantial expansion of the ground-based observation networks required to reach the high spatial resolution for CO2 and CH4 fluxes, and for carbon stocks for addressing policy-relevant objectives, and attributing flux changes to underlying processes in each region. In order to establish flux and stock diagnostics over areas such as the southern oceans, tropical forests, and the Arctic, in situ observations will have to be complemented with remote-sensing measurements. Remote sensing offers the advantage of dense spatial coverage and frequent revisit. A key challenge is to bring remote-sensing measurements to a level of long-term consistency and accuracy so that they can be efficiently combined in models to reduce uncertainties, in synergy with ground-based data. Bringing tight observational constraints on fossil fuel and land use change emissions will be the biggest challenge for deployment of a policy-relevant integrated carbon observation system. This will require in situ and remotely sensed data at much higher </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9908E..2WP','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9908E..2WP">Development of the FPI+ as facility science instrument for SOFIA cycle four observations</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Pfüller, Enrico; Wiedemann, Manuel; Wolf, Jürgen; Krabbe, Alfred 2016-08-01 The Stratospheric Observatory for Infrared Astronomy (SOFIA) is a heavily modified Boeing 747SP aircraft, accommodating a 2.5m infrared telescope. This airborne observation platform takes astronomers to flight altitudes of up to 13.7 km (45,000ft) and therefore allows an unobstructed view of the infrared universe at wavelengths between 0.3 m and 1600 m. SOFIA is currently completing its fourth cycle of observations and utilizes eight different imaging and spectroscopic science instruments. New instruments for SOFIAs cycle 4 observations are the High-resolution Airborne Wideband Camera-plus (HAWC+) and the Focal Plane Imager (FPI+). The latter is an integral part of the telescope assembly and is used on every SOFIA flight to ensure precise tracking on the desired targets. The FPI+ is used as a visual-light photometer in its role as facility science instrument. Since the upgrade of the FPI camera and electronics in 2013, it uses a thermo-electrically cooled science grade EM-CCD sensor inside a commercial-off-the-shelf Andor camera. The back-illuminated sensor has a peak quantum efficiency of 95% and the dark current is as low as 0.01 e-/pix/sec. With this new hardware the telescope has successfully tracked on 16th magnitude stars and thus the sky coverage, e.g. the area of sky that has suitable tracking stars, has increased to 99%. Before its use as an integrated tracking imager, the same type of camera has been used as a standalone diagnostic tool to analyze the telescope pointing stability at frequencies up to 200 Hz (imaging with 400 fps). These measurements help to improve the telescope pointing control algorithms and therefore reduce the image jitter in the focal plane. Science instruments benefit from this improvement with smaller image sizes for longer exposure times. The FPI has also been used to support astronomical observations like stellar occultations by the dwarf planet Pluto and a number of exoplanet transits. Especially the observation of the </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150019792','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150019792">Launch Complex 39 Observation Gantry Area (SWMU# 107) Annual Long-Term Monitoring Report (Year 1) Kennedy Space Center, Florida</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Johnson, Jill W.; Towns, Crystal 2015-01-01 This document has been prepared by Geosyntec Consultants, Inc. (Geosyntec) to present and discuss the findings of the 2014 and 2015 Long-Term Monitoring (LTM) activities that were completed at the Launch Complex 39 (LC39) Observation Gantry Area (OGA) located at the John F. Kennedy Space Center (KSC), Florida (Site). The remainder of this report includes: (i) a description of the Site location; (ii) summary of Site background and previous investigations; (iii) description of field activities completed as part of the annual LTM program at the Site; (iv) groundwater flow evaluation; (v) presentation and discussion of field and analytical results; and (vi) conclusions and recommendations. Applicable KSC Remediation Team (KSCRT) Meeting minutes are included in Attachment A. This Annual LTM Letter Report was prepared by Geosyntec Consultants (Geosyntec) for NASA under contract number NNK12CA13B, Delivery Order NNK13CA39T project number PCN ENV2188. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMGC13A1066A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMGC13A1066A">Climate change impact on the annual water balance in the northwest Florida coastal</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Alizad, K.; Wang, D.; Alimohammadi, N.; Hagen, S. C. 2012-12-01 As the largest tributary to the Apalachicola River, the Chipola River originates in southern Alabama, flows through Florida Panhandle and ended to Gulf of Mexico. The Chipola watershed is located in an intermediate climate environment with aridity index around one. Watershed provides habitat for a number of threatened and endangered animal and plant species. However, climate change affects hydrologic cycle of Chipola River watershed at various temporal and spatial scales. Studying the effects of climate variations is of great importance for water and environmental management purposes in this catchment. This research is mainly focuses on assessing climate change impact on the partitioning pattern of rainfall from mean annual to inter-annual and to seasonal scales. At the mean annual scale, rainfall is partitioned into runoff and evaporation assuming negligible water storage changes. Mean annual runoff is controlled by both mean annual precipitation and potential evaporation. Changes in long term mean runoff caused by variations of long term mean precipitation and potential evaporation will be evaluated based on Budyko hypothesis. At the annual scale, rainfall is partitioned into runoff, evaporation, and storage change. Inter-annual variability of runoff and evaporation are mainly affected by the changes of mean annual climate variables as well as their inter-annual variability. In order to model and evaluate each component of water balance at the annual scale, parsimonious but reliable models, are developed. Budyko hypothesis on the existing balance between available water and energy supply is reconsidered and redefined for the sub-annual time scale and reconstructed accordingly in order to accurately model seasonal hydrologic balance of the catchment. Models are built in the seasonal time frame with a focus on the role of storage change in water cycle. Then for Chipola catchment, models are parameterized based on a sufficient time span of historical data and the </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5453695','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5453695">Experimental and observational studies find contrasting responses of soil nutrients to climate change</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> Yuan, ZY; Jiao, F; Shi, XR; Sardans, Jordi; Maestre, Fernando T; Delgado-Baquerizo, Manuel; Reich, Peter B; Peñuelas, Josep 2017-01-01 Manipulative experiments and observations along environmental gradients, the two most common approaches to evaluate the impacts of climate change on nutrient cycling, are generally assumed to produce similar results, but this assumption has rarely been tested. We did so by conducting a meta-analysis and found that soil nutrients responded differentially to drivers of climate change depending on the approach considered. Soil carbon, nitrogen, and phosphorus concentrations generally decreased with water addition in manipulative experiments but increased with annual precipitation along environmental gradients. Different patterns were also observed between warming experiments and temperature gradients. Our findings provide evidence of inconsistent results and suggest that manipulative experiments may be better predictors of the causal impacts of short-term (months to years) climate change on soil nutrients but environmental gradients may provide better information for long-term correlations (centuries to millennia) between these nutrients and climatic features. Ecosystem models should consequently incorporate both experimental and observational data to properly assess the impacts of climate change on nutrient cycling. DOI: http://dx.doi.org/10.7554/eLife.23255.001 PMID:28570219 </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title12-vol3/pdf/CFR-2010-title12-vol3-sec226-14.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title12-vol3/pdf/CFR-2010-title12-vol3-sec226-14.pdf">12 CFR 226.14 - Determination of annual percentage rate.</a> <a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a> 2010-01-01 ... percentage point above or below the annual percentage rate determined in accordance with this section. 31a... finance charge for the billing cycle by the sum of the balances to which the periodic rates were applied... of the balance(s) to which it is applicable 32 and multiplying the quotient (expressed as a... </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSAH24A0040P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSAH24A0040P">Drivers of the Seasonal Carbon Cycle in the Coastal Gulf of Alaska</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Pilcher, D.; Siedlecki, S. A.; Hermann, A. J.; Coyle, K. O.; Mathis, J. T. 2016-02-01 The Coastal Gulf of Alaska serves as a significant carbon sink annually, but varies seasonally from net carbon efflux in winter, to net carbon uptake from spring through fall. This significant uptake of anthropogenic CO2 combined with the naturally cold, low calcium carbonate surface waters is expected to accelerate ocean acidification. Observational evidence has already detected subsurface aragonite undersaturation, likely resulting from carbon remineralization of sinking organic matter. Other processes such as storm-induced vertical mixing, glacial runoff, temperature change, and nutrient supply can further modify the carbon cycle. Improving knowledge of these seasonal processes is critical for the region's fisheries that provide substantial ecosystem services and can be adversely impacted by sub-optimal aragonite saturation conditions. We use a regional model of the Coastal Gulf of Alaska coupled to an ecosystem model with full carbonate chemistry to investigate the physical and biogeochemical mechanisms that drive the seasonal carbon cycle. Boundary conditions are set from the coarser Northeast Pacific model, with alkalinity and carbon concentrations determined from empirical relationships with salinity. Model output from a 2009 hindcast simulation is compared to observations of alkalinity and dissolved inorganic carbon concentrations for model verification and to elucidate seasonal mechanisms. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2012-08-14/pdf/2012-19840.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2012-08-14/pdf/2012-19840.pdf">77 FR 48583 - 2012 Special 301 Out-of-Cycle Review of Notorious Markets: Request for Public Comments</a> <a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a> 2012-08-14 ... TRADE REPRESENTATIVE 2012 Special 301 Out-of-Cycle Review of Notorious Markets: Request for Public... publishing the notorious market list as an ``Out of Cycle Review'' separately from the annual Special 301....gov , docket number USTR-2012-0011. Submissions should contain the term ``2012 Out-of-Cycle Review of... </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950029597&hterms=1042&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3D%2526%25231042','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950029597&hterms=1042&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3D%2526%25231042">Speeds of coronal mass ejections: SMM observations from 1980 and 1984-1989</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Hundhausen, A. J.; Burkepile, J. T.; St. Cyr, O. C. 1994-01-01 The speeds of 936 features in 673 coronal mass ejections have been determined from trajectories observed with the Solar Maximum Mission (SMM) coronagraph in 1980 and 1984 to 1989. The distribution of observed speeds has a range (from 5th to 95th percentile) of 35 to 911 km/s; the average and median speeds are 349 and 285 km/s. The speed distributions of some selected classes of mass ejections are significantly different. For example, the speeds of 331 'outer loops' range from 80 to 1042 km/s; the average and median speeds for this class of ejections are 445 and 372 km/s. The speed distributions from each year of SMM observations show significant changes, with the annual average speeds varying from 157 (1984) to 458 km/s (1985). These variations are not simply related to the solar activity cycle; the annual averages from years near the sunspot maxima and minimum are not significantly different. The widths, latitudes, and speeds of mass ejections determined from the SMM observations are only weakly correlated. In particular, mass ejection speeds vary only slightly with the heliographic latitudes of the ejection. High-latitude ejections, which occur well poleward of the active latitudes, have speeds similar to active latitude ejections. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1392950','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1392950">In Situ NMR Observation of the Temporal Speciation of Lithium Sulfur Batteries during Electrochemical Cycling</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Wang, Hao; Sa, Niya; He, Meinan The understanding of the reaction mechanism and temporal speciation of the lithium sulfur batteries is challenged by complex polysulfide disproportionation chemistry coupled with the precipitation and dissolution of species. In this report, for the first time, we present a comprehensive method to investigate lithium sulfur electrochemistry using in situ 7Li NMR spectroscopy, a technique that is capable of quantitatively capturing the evolution of the soluble and precipitated lithium (poly)sulfides during electrochemical cycling. Furthermore, through deconvolution and quantification, every lithium-bearing species was closely tracked and four-step soluble lithium polysulfide-mediated lithium sulfur electrochemistry was demonstrated in never before seen detail. Significant irreversiblemore » accumulation of Li 2S is observed on the Li metal anode after four cycles because of sulfur shuttling. We present the application of the method in order to study electrolyte/additive development and lithium protection research can be readily envisaged.« less </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1392950-situ-nmr-observation-temporal-speciation-lithium-sulfur-batteries-during-electrochemical-cycling','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1392950-situ-nmr-observation-temporal-speciation-lithium-sulfur-batteries-during-electrochemical-cycling">In Situ NMR Observation of the Temporal Speciation of Lithium Sulfur Batteries during Electrochemical Cycling</a> <a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a> Wang, Hao; Sa, Niya; He, Meinan; ... 2017-03-03 The understanding of the reaction mechanism and temporal speciation of the lithium sulfur batteries is challenged by complex polysulfide disproportionation chemistry coupled with the precipitation and dissolution of species. In this report, for the first time, we present a comprehensive method to investigate lithium sulfur electrochemistry using in situ 7Li NMR spectroscopy, a technique that is capable of quantitatively capturing the evolution of the soluble and precipitated lithium (poly)sulfides during electrochemical cycling. Furthermore, through deconvolution and quantification, every lithium-bearing species was closely tracked and four-step soluble lithium polysulfide-mediated lithium sulfur electrochemistry was demonstrated in never before seen detail. Significant irreversiblemore » accumulation of Li 2S is observed on the Li metal anode after four cycles because of sulfur shuttling. We present the application of the method in order to study electrolyte/additive development and lithium protection research can be readily envisaged.« less </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSPC13A..01S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSPC13A..01S">The Seasonal Cycle of Carbon in the Southern Pacific Ocean Observed from Biogeochemical Profiling Floats</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Sarmiento, J. L.; Gray, A. R.; Johnson, K. S.; Carter, B.; Riser, S.; Talley, L. D.; Williams, N. L. 2016-02-01 The Southern Ocean is thought to play an important role in the ocean-atmosphere exchange of carbon dioxide and the uptake of anthropogenic carbon dioxide. However, the total number of observations of the carbonate system in this region is small and heavily biased towards the summer. Here we present 1.5 years of biogeochemical measurements, including pH, oxygen, and nitrate, collected by 11 autonomous profiling floats deployed in the Pacific sector of the Southern Ocean in April 2014. These floats sampled a variety of oceanographic regimes ranging from the seasonally ice-covered zone to the subtropical gyre. Using an algorithm trained with bottle measurements, alkalinity is estimated from salinity, temperature, and oxygen and then used together with the measured pH to calculate total carbon dioxide and pCO2 in the upper 1500 dbar. The seasonal cycle in the biogeochemical quantities is examined, and the factors governing pCO2 in the surface waters are analyzed. The mechanisms driving the seasonal cycle of carbon are further investigated by computing budgets of heat, carbon, and nitrogen in the mixed layer. Comparing the different regimes sampled by the floats demonstrates the complex and variable nature of the carbon cycle in the Southern Ocean. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017IAUS..328..130D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017IAUS..328..130D">Deriving the solar activity cycle modulation on cosmic ray intensity observed by Nagoya muon detector from October 1970 until December 2012</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> de Mendonça, Rafael R. S.; Braga, Carlos. R.; Echer, Ezequiel; Dal Lago, Alisson; Rockenbach, Marlos; Schuch, Nelson J.; Munakata, Kazuoki 2017-10-01 It is well known that the cosmic ray intensity observed at the Earth's surface presents an 11 and 22-yr variations associated with the solar activity cycle. However, the observation and analysis of this modulation through ground muon detectors datahave been difficult due to the temperature effect. Furthermore, instrumental changes or temporary problems may difficult the analysis of these variations. In this work, we analyze the cosmic ray intensity observed since October 1970 until December 2012 by the Nagoya muon detector. We show the results obtained after analyzing all discontinuities and gaps present in this data and removing changes not related to natural phenomena. We also show the results found using the mass weighted method for eliminate the influence of atmospheric temperature changes on muon intensity observed at ground. As a preliminary result of our analyses, we show the solar cycle modulation in the muon intensity observed for more than 40 years. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3864727','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3864727">Dormancy cycling and persistence of seeds in soil of a cold desert halophyte shrub</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> Cao, Dechang; Baskin, Carol C.; Baskin, Jerry M.; Yang, Fan; Huang, Zhenying 2014-01-01 Background and Aims Formation of seed banks and dormancy cycling are well known in annual species, but not in woody species. In this study it was hypothesized that the long-lived halophytic cold desert shrub Kalidium gracile has a seed bank and dormancy cycling, which help restrict germination to a favourable time for seedling survival. Methods Fresh seeds were buried in November 2009 and exhumed and tested for germination monthly from May 2010 to December 2011 over a range of temperatures and salinities. Germination recovery and viability were determined after exposure to salinity and water stress. Seedling emergence and dynamics of the soil seed bank were investigated in the field. Key Results Seeds of K. gracile had a soil seed bank of 7030 seeds m−2 at the beginning of the growing season. About 72 % of the seeds were depleted from the soil seed bank during a growing season, and only 1·4 % of them gave rise to seedlings that germinated early enough to reach a stage of growth at which they could survive to overwinter. About 28 % of the seeds became part of a persistent soil seed bank. Buried seeds exhibited an annual non-dormancy/conditional dormancy (ND/CD) cycle, and germination varied in sensitivity to salinity during the cycle. Dormancy cycling is coordinated with seasonal environmental conditions in such a way that the seeds germinate in summer, when there is sufficient precipitation for seedling establishment. Conclusions Kalidium gracile has three life history traits that help ensure persistence at a site: a polycarpic perennial life cycle, a persistent seed bank and dormancy cycling. The annual ND/CD cycle in seeds of K. gracile contributes to seedling establishment of this species in the unpredictable desert environment and to maintenance of a persistent soil seed bank. This is the first report of a seed dormancy cycle in a cold desert shrub. PMID:24249808 </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AdSpR..60..257K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AdSpR..60..257K">Seasonal and solar cycle effects on TEC at 95°E in the ascending half (2009-2014) of the subdued solar cycle 24: Consistent underestimation by IRI 2012</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Kakoti, Geetashree; Bhuyan, Pradip Kumar; Hazarika, Rumajyoti 2017-07-01 TEC measured at Dibrugarh (27.5°N, 94.9°E, 17.5°N Geomag.) from 2009 to 2014 is used to study its temporal characteristics during the ascending half of solar cycle 24. The measurements provide an opportunity to assess the diurnal, seasonal and longterm predictability of the IRI 2012 (with IRI Nequick, IRI01-corr, IRI 2001topside options) during this solar cycle which is distinctively low in magnitude compared to the previous cycles. The low latitude station Dibrugarh is normally located at the poleward edge of the northern EIA. A semi-annual variation in GPS TEC is observed with the peaks occurring in the equinoxes. The peak in spring (March, April) is higher than that in autumn (September, October) irrespective of the year of observation. The spring autumn asymmetry is also observed in IRI TEC. In contrast, the winter (November, December, January, February) anomaly is evident only in high activity years. TEC bears a distinct nonlinear relationship with 10.7 cm solar flux (F10.7). TEC increases linearly with F10.7 up to about 125 sfu beyond which it tends to saturate. The correlation between TEC and solar flux is found to be a function of local time and peaks at 10:00 LT. TEC varies nonlinearly with solar EUV flux similar to its variation with F10.7. The nonlinearity is well captured by the IRI. The saturation of TEC at high solar activity is attributed to the inability of the ionosphere to accommodate more ionization after it reaches the level of saturation ion pressure. Annual mean TEC increased from the minimum in 2009 almost linearly till 2012, remains at the same level in 2013 and then increased again in 2014. IRI TEC shows a linear increase from 2009 to 2014. IRI01-corr and IRI-NeQuick TEC are nearly equal at all local times, season and year of observation while IRI-2001 simulated TEC are always higher than that simulated by the other two versions. The IRI 2012 underestimates the TEC at about all local times except for a few hours in the midday in all </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22365939-solar-cycle-producing-more-coronal-mass-ejections-than-cycle','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22365939-solar-cycle-producing-more-coronal-mass-ejections-than-cycle">IS SOLAR CYCLE 24 PRODUCING MORE CORONAL MASS EJECTIONS THAN CYCLE 23?</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Wang, Y.-M.; Colaninno, R., E-mail: yi.wang@nrl.navy.mil, E-mail: robin.colaninno@nrl.navy.mil 2014-04-01 Although sunspot numbers are roughly a factor of two lower in the current cycle than in cycle 23, the rate of coronal mass ejections (CMEs) appears to be at least as high in 2011-2013 as during the corresponding phase of the previous cycle, according to three catalogs that list events observed with the Large Angle and Spectrometric Coronagraph (LASCO). However, the number of CMEs detected is sensitive to such factors as the image cadence and the tendency (especially by human observers) to under-/overcount small or faint ejections during periods of high/low activity. In contrast to the total number, the totalmore » mass of CMEs is determined mainly by larger events. Using the mass measurements of 11,000 CMEs given in the manual CDAW catalog, we find that the mass loss rate remains well correlated with the sunspot number during cycle 24. In the case of the automated CACTus and SEEDS catalogs, the large increase in the number of CMEs during cycle 24 is almost certainly an artifact caused by the near-doubling of the LASCO image cadence after mid-2010. We confirm that fast CMEs undergo a much stronger solar-cycle variation than slow ones, and that the relative frequency of slow and less massive CMEs increases with decreasing sunspot number. We conclude that cycle 24 is not only producing fewer CMEs than cycle 23, but that these ejections also tend to be slower and less massive than those observed one cycle earlier.« less </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28738815','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28738815">Transcription through the eye of a needle: daily and annual cyclic gene expression variation in Douglas-fir needles.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Cronn, Richard; Dolan, Peter C; Jogdeo, Sanjuro; Wegrzyn, Jill L; Neale, David B; St Clair, J Bradley; Denver, Dee R 2017-07-24 Perennial growth in plants is the product of interdependent cycles of daily and annual stimuli that induce cycles of growth and dormancy. In conifers, needles are the key perennial organ that integrates daily and seasonal signals from light, temperature, and water availability. To understand the relationship between seasonal cycles and seasonal gene expression responses in conifers, we examined diurnal and circannual needle mRNA accumulation in Douglas-fir (Pseudotsuga menziesii) needles at diurnal and circannual scales. Using mRNA sequencing, we sampled 6.1 × 10 9 reads from 19 trees and constructed a de novo pan-transcriptome reference that includes 173,882 tree-derived transcripts. Using this reference, we mapped RNA-Seq reads from 179 samples that capture daily and annual variation. We identified 12,042 diurnally-cyclic transcripts, 9299 of which showed homology to annotated genes from other plant genomes, including angiosperm core clock genes. Annual analysis revealed 21,225 circannual transcripts, 17,335 of which showed homology to annotated genes from other plant genomes. The timing of maximum gene expression is associated with light intensity at diurnal scales and photoperiod at annual scales, with approximately half of transcripts reaching maximum expression +/- 2 h from sunrise and sunset, and +/- 20 days from winter and summer solstices. Comparisons with published studies from other conifers shows congruent behavior in clock genes with Japanese cedar (Cryptomeria), and a significant preservation of gene expression patterns for 2278 putative orthologs from Douglas-fir during the summer growing season, and 760 putative orthologs from spruce (Picea) during the transition from fall to winter. Our study highlight the extensive diurnal and circannual transcriptome variability demonstrated in conifer needles. At these temporal scales, 29% of expressed transcripts show a significant diurnal cycle, and 58.7% show a significant circannual cycle. Remarkably </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20090017773','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20090017773">Evidence for Solar Cycle Influence on the Infrared Energy Budget and Radiative Cooling of the Thermosphere</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Mlynczak, Martin G.; Martin-Torres, F. Javier; Marshall, B. Thomas; Thompson, R. Earl; Williams, Joshua; Turpin, TImothy; Kratz, D. P.; Russell, James M.; Woods, Tom; Gordley, Larry L. 2007-01-01 We present direct observational evidence for solar cycle influence on the infrared energy budget and radiative cooling of the thermosphere. By analyzing nearly five years of data from the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument, we show that the annual mean infrared power radiated by the nitric oxide (NO) molecule at 5.3 m has decreased by a factor of 2.9. This decrease is correlated (r = 0.96) with the decrease in the annual mean F10.7 solar index. Despite the sharp decrease in radiated power (which is equivalent to a decrease in the vertical integrated radiative cooling rate), the variability of the power as given in the standard deviation of the annual means remains approximately constant. A simple relationship is shown to exist between the infrared power radiated by NO and the F10.7 index, thus providing a fundamental relationship between solar activity and the thermospheric cooling rate for use in thermospheric models. The change in NO radiated power is also consistent with changes in absorbed ultraviolet radiation over the same time period. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.8951S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.8951S">Global synthesis of long-term cloud condensation nuclei observations</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Schmale, Julia; Henning, Silvia; Stratmann, Frank; Henzing, Bas; Schlag, Patrick; Aalto, Pasi; Keskinen, Helmi; Sellegri, Karine; Ovadnevaite, Jurgita; Krüger, Mira; Jefferson, Anne; Whitehead, James; Carslaw, Ken; Yum, Seong Soo; Kristensson, Adam; Baltensperger, Urs; Gysel, Martin 2016-04-01 Cloud condensation nuclei (CCN) are aerosol particles with the ability to activate into droplets at a given super saturation and therefore influence the microphysical and optical properties of clouds. To predict cloud radiative properties understanding the spatial and temporal variability of CCN concentrations in different environments is important. However, currently, the effects of atmospheric particles on changes in cloud radiative forcing are still the largest contribution of uncertainty in climate forcing prediction (IPCC, 2013). Numerous intensive field campaigns have already explored detailed characteristics of CCN in many locations around the world. However, these rather short-term observations can generally not address seasonal or inter-annual variations and a comparison between campaign sites is difficult due to the higher influence of specific environmental circumstances on short-term measurements results. Here, we present results of more long-term CCN and aerosol number concentrations as well as size distribution data covering at least one full year between 2006 and 2014. The 12 locations include ACTRIS stations (http://www.actris.net/) in Europe, and further sites in North America, Brazil and Korea. The sites are located in different environments allowing for temporal and spatial characterization of CCN variability in different atmospheric regimes. Those include marine, remote-continental, boreal forest, rain forest, Arctic and monsoon-influenced environments, as well as boundary layer and free tropospheric conditions. The aerosol populations and their activation behavior show significant differences across the stations. While peak concentrations of CCN are observed in summer at the high altitude sites, in the Arctic the highest concentrations occur during the Haze period in spring. The rural-marine and rural-continental sites exhibit similar CCN concentration characteristics with a relatively flat annual cycle. At some stations, e.g. in the boreal </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001PrOce..49..283B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001PrOce..49..283B">The seasonal cycle revisited: interannual variation and ecosystem consequences</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Bertram, Douglas F.; Mackas, David L.; McKinnell, Stewart M. The annual seasonal cycle accounts for much of the total temporal variability of mid- and high-latitude marine ecosystems. Although the general pattern of the seasons repeats each year, climatic variability of the atmosphere and the ocean produce detectable changes in intensity and onset timing. We use a combination of time series data from oceanographic, zooplankton and seabird breeding data to ask if and how these variations in the timing of the spring growing season affect marine populations. For the physical environment, we develop an annual index of spring timing by fitting a non-linear 2-parameter periodic function to the average weekly SST data observed in British Columbia from 1 January to the end of August each year. For each year, the phase parameter describes the timing of seasonal warming (the timing index) and the amplitude parameter describes the magnitude of the temperature increase between the fitted winter minimum and summer maximum. For the zooplankton, which have annual and strongly synchronous cycles of biomass, productivity, and developmental sequence, we use copepodite stage composition to index the timing of the annual maximum. For seabirds, we examine (1975-1999) the timing of hatching, nestling growth performance, and diet for four species of alcids at Triangle Island, British Columbia's largest seabird colony and the world's largest population of the planktivorous Cassin's auklet. Temperature, zooplankton, and seabirds have all shown recent decadal trends toward ‘earlier spring’, but the magnitudes of the timing perturbations have differed from variable to variable and from year to year. Recent (1996-1999) extreme interannual variation in spring timing and April SST helped to facilitate a mechanistic investigation of oceanographic features that affect the reproductive performance of seabirds. Our results demonstrate a significant negative relationship between the annual spring timing index (and April mean SST) and nestling growth rates </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active">17</li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active">18</li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=288864','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=288864">Gap filling strategies and error in estimating annual soil respiration</a> <a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a> Soil respiration (Rsoil) is one of the largest CO2 fluxes in the global carbon (C) cycle. Estimation of annual Rsoil requires extrapolation of survey measurements or gap-filling of automated records to produce a complete time series. While many gap-filling methodologies have been employed, there is ... </li> <li> <a target="_blank" onclick="trackOutboundLink('http://www.noaa.gov/node/1709','SCIGOVWS'); return false;" href="http://www.noaa.gov/node/1709">Record annual increase of carbon dioxide observed at Mauna Loa for 2015 |</a> <a target="_blank" href="http://www.science.gov/aboutsearch.html">Science.gov Websites</a> related to atmospheric change since the 1950's. The annual growth rate of atmospheric carbon dioxide year. Continued high emissions from fossil fuel consumption are driving the underlying growth rate over </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2013-09-20/pdf/2013-22857.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2013-09-20/pdf/2013-22857.pdf">78 FR 57924 - 2013 Special 301 Out-Of-Cycle Review of Notorious Markets: Request For Public Comments</a> <a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a> 2013-09-20 ...-Of-Cycle Review of Notorious Markets: Request For Public Comments AGENCY: Office of the United States... market list as an ``Out-of-Cycle Review'' separately from the annual Special 301 report. This review of... Out-of-Cycle Review of Notorious Markets'' in the ``Type Comment'' field on http://www.regulations.gov... </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1198482-variable-stoichiometry-dissolved-organic-matter-cycling-community-earth-system-model','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1198482-variable-stoichiometry-dissolved-organic-matter-cycling-community-earth-system-model">Variable C : N : P stoichiometry of dissolved organic matter cycling in the Community Earth System Model</a> <a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a> Letscher, R. T.; Moore, J. K.; Teng, Y. -C.; ... 2014-06-16 Dissolved organic matter (DOM) plays an important role in the ocean's biological carbon pump by providing an advective/mixing pathway for ~ 20% of export production. DOM is known to have a stoichiometry depleted in nitrogen (N) and phosphorus (P) compared to the particulate organic matter pool, a~fact that is often omitted from biogeochemical-ocean general circulation models. However the variable C : N : P stoichiometry of DOM becomes important when quantifying carbon export from the upper ocean and linking the nutrient cycles of N and P with that of carbon. Here we utilize recent advances in DOM observational data coveragemore » and offline tracer-modeling techniques to objectively constrain the variable production and remineralization rates of the DOM C / N / P pools in a simple biogeochemical-ocean model of DOM cycling. The optimized DOM cycling parameters are then incorporated within the Biogeochemical Elemental Cycling (BEC) component of the Community Earth System Model and validated against the compilation of marine DOM observations. The optimized BEC simulation including variable DOM C : N : P cycling was found to better reproduce the observed DOM spatial gradients than simulations that used the canonical Redfield ratio. Global annual average export of dissolved organic C, N, and P below 100 m was found to be 2.28 Pg C yr -1 (143 Tmol C yr -1), 16.4 Tmol N yr -1, and 1 Tmol P yr -1, respectively with an average export C : N : P stoichiometry of 225 : 19 : 1 for the semilabile (degradable) DOM pool. DOC export contributed ~ 25% of the combined organic C export to depths greater than 100 m.« less </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.B54C..06R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.B54C..06R">Nitrogen and Phosphorus Plant Uptake During Periods with no Photosynthesis Accounts for About Half of Global Annual Uptake</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Riley, W. J.; Zhu, Q.; Tang, J. 2017-12-01 Uncertainties in current Earth System Model (ESM) predictions of terrestrial carbon-climate feedbacks over the 21st century are as large as, or larger than, any other reported natural system uncertainties. Soil Organic Matter (SOM) decomposition and photosynthesis, the dominant fluxes in this regard, are tightly linked through nutrient availability, and the recent Coupled Model Inter-comparison Project 5 (CMIP5) used for climate change assessment had no credible representations of these constraints. In response, many ESM land models (ESMLMs) have developed dynamic and coupled soil and plant nutrient cycles. Here we quantify terrestrial carbon cycle impacts from well-known observed plant nutrient uptake mechanisms ignored in most current ESMLMs. In particular, we estimate the global role of plant root nutrient competition with microbes and abiotic process at night and during the non-growing season using the ACME land model (ALMv1-ECA-CNP) that explicitly represents these dynamics. We first demonstrate that short-term nutrient uptake dynamics and competition between plants and microbes are accurately predicted by the model compared to 15N and 33P isotopic tracer measurements from more than 20 sites. We then show that global nighttime and non-growing season nitrogen and phosphorus uptake accounts for 46 and 45%, respectively, of annual uptake, with large latitudinal variation. Model experiments show that ignoring these plant uptake periods leads to large positive biases in annual N leaching (globally 58%) and N2O emissions (globally 68%). Biases these large will affect modeled carbon cycle dynamics over time, and lead to predictions of ecosystems that have overly open nutrient cycles and therefore lower capacity to sequester carbon. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006JGRC..11111010S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006JGRC..11111010S">The large-scale freshwater cycle of the Arctic</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Serreze, Mark C.; Barrett, Andrew P.; Slater, Andrew G.; Woodgate, Rebecca A.; Aagaard, Knut; Lammers, Richard B.; Steele, Michael; Moritz, Richard; Meredith, Michael; Lee, Craig M. 2006-11-01 This paper synthesizes our understanding of the Arctic's large-scale freshwater cycle. It combines terrestrial and oceanic observations with insights gained from the ERA-40 reanalysis and land surface and ice-ocean models. Annual mean freshwater input to the Arctic Ocean is dominated by river discharge (38%), inflow through Bering Strait (30%), and net precipitation (24%). Total freshwater export from the Arctic Ocean to the North Atlantic is dominated by transports through the Canadian Arctic Archipelago (35%) and via Fram Strait as liquid (26%) and sea ice (25%). All terms are computed relative to a reference salinity of 34.8. Compared to earlier estimates, our budget features larger import of freshwater through Bering Strait and larger liquid phase export through Fram Strait. While there is no reason to expect a steady state, error analysis indicates that the difference between annual mean oceanic inflows and outflows (˜8% of the total inflow) is indistinguishable from zero. Freshwater in the Arctic Ocean has a mean residence time of about a decade. This is understood in that annual freshwater input, while large (˜8500 km3), is an order of magnitude smaller than oceanic freshwater storage of ˜84,000 km3. Freshwater in the atmosphere, as water vapor, has a residence time of about a week. Seasonality in Arctic Ocean freshwater storage is nevertheless highly uncertain, reflecting both sparse hydrographic data and insufficient information on sea ice volume. Uncertainties mask seasonal storage changes forced by freshwater fluxes. Of flux terms with sufficient data for analysis, Fram Strait ice outflow shows the largest interannual variability. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMSH43B2808I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMSH43B2808I">SSI Variations in the visible as observed with SOLAR/SOLSPEC during cycle 24 - Comparison with SORCE/SIM.</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Irbah, A.; Damé, L.; Meftah, M.; Bekki, S.; Bolsée, D. 2017-12-01 The solar spectral irradiance (SSI) and its temporal variations are of prime importance to apprehend the physics of the Sun and to understand its effects on Earth climate through changes of atmospheric properties. Ground based measurements of SSI are indeed affected by the Earth atmosphere and space observations are therefore required to perform adequate observations. Only a few long series of SSI space measurements were obtained these last decades. The SOLSPEC instrument of the SOLAR payload on the International Space Station (ISS) has recorded one of them from April 2008 to February 2017 covering almost the whole solar cycle 24. The instrument is a spectro-radiometer recording data of the Sun from 166 to 3088 nm. Operated from the ISS in a harsh environment it needed appropriate processing methods to extract significant scientific results from noise and instrumental effects. We present the methods used to process the data to evidence visible SSI variations during cycle 24. We discuss the results obtained showing SSI variations in phase with solar activity. We compare them with SORCE/SIM measurements. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED504232.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED504232.pdf">Now What? Youth at the Crossroads. 2008 Annual Report</a> <a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a> Children's Aid Society, 2008 2008-01-01 This annual report focuses on teens returning from incarceration in the juvenile justice system. With alarmingly high recidivism rates, many of these young people cycle in and out of the justice system for the rest of their lives. The report includes a brief history of the organization and its commitment to the well-being of New York City… </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20080045496&hterms=Qbo&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DQbo','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20080045496&hterms=Qbo&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DQbo">Modeling the Observed QBO and Inter-Annual Variations of the Diurnal Tide in the Mesosphere</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Mayr, Hans G.; Mengel, John G.; Huang, F. T. 2006-01-01 In the current version of the Numerical Spectral Model (NSM), the Quasi-biennial Oscillation (QBO) is generated primarily by small-scale gravity waves (GW) from Hines' Doppler Spread Parameterization (DSP). The model does not have topography, and the planetary waves are solely generated by instabilities. We discuss a 3D modeling study that describes the QBO extending from the stratosphere into the upper mesosphere, where the oscillation produces significant inter-annual variations in the diurnal tide. The numerical results are compared with temperature measurements from the SABER (TIMED) and MLS (UARS) instruments obtained by Huang et al. (2006). With a GW source that peaks at the Equator and is taken to be isotropic and independent of season, the NSM generates a QBO with variable periods around 26 months and zonal wind amplitudes of almost 25 m/s at 30 km. As reported earlier, the NSM reproduces the observed equinoctial maxima in the diurnal tide at altitudes around 95 km. The modeled QBO modulates the tide such that the seasonal amplitude maxima can vary from one year to another by as much as 30%. To shed light on the underlying mechanisms, the relative importance of the advection terms are discussed, and they are shown to be important in the stratosphere. At altitudes above 80 km, however, the QBO-related inter-annual variations of the tide are generated primarily by GW momentum deposition. In qualitative agreement with the SABER measurements, the model generates distinct zonal-mean QBO temperature variations in the stratosphere and mesosphere. In the stratosphere, the computed amplitudes are not much smaller than those observed, and the rate of downward propagation at the Equator is reproduced. The modeled temperature amplitudes in the mesosphere, however, are much smaller than those observed. The observed and computed temperature variations of the QBO peak at the Equator but extend with phase reversals to high latitudes, in contrast to the zonal winds that are </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999JMS....19..173H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999JMS....19..173H">Modelling the pelagic nitrogen cycle and vertical particle flux in the Norwegian sea</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Haupt, Olaf J.; Wolf, Uli; v. Bodungen, Bodo 1999-02-01 A 1D Eulerian ecosystem model (BIological Ocean Model) for the Norwegian Sea was developed to investigate the dynamics of pelagic ecosystems. The BIOM combines six biochemical compartments and simulates the annual nitrogen cycle with specific focus on production, modification and sedimentation of particles in the water column. The external forcing and physical framework is based on a simulated annual cycle of global radiation and an annual mixed-layer cycle derived from field data. The vertical resolution of the model is given by an exponential grid with 200 depth layers, allowing specific parameterization of various sinking velocities, breakdown of particles and the remineralization processes. The aim of the numerical experiments is the simulation of ecosystem dynamics considering the specific biogeochemical properties of the Norwegian Sea, for example the life cycle of the dominant copepod Calanus finmarchicus. The results of the simulations were validated with field data. Model results are in good agreement with field data for the lower trophic levels of the food web. With increasing complexity of the organisms the differences increase between simulated processes and field data. Results of the numerical simulations suggest that BIOM is well adapted to investigate a physically controlled ecosystem. The simulation of grazing controlled pelagic ecosystems, like the Norwegian Sea, requires adaptations of parameterization to the specific ecosystem features. By using seasonally adaptation of the most sensible processes like utilization of light by phytoplankton and grazing by zooplankton results were greatly improved. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110004191','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110004191">Observed Seasonal to Decadal-Scale Responses in Mesospheric Water Vapor</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Remsberg, Ellis 2010-01-01 The 14-yr (1991-2005) time series of mesospheric water vapor from the Halogen Occultation Experiment (HALOE) are analyzed using multiple linear regression (MLR) techniques for their6 seasonal and longer-period terms from 45S to 45N. The distribution of annual average water vapor shows a decrease from a maximum of 6.5 ppmv at 0.2 hPa to about 3.2 ppmv at 0.01 hPa, in accord with the effects of the photolysis of water vapor due to the Lyman-flux. The distribution of the semi-annual cycle amplitudes is nearly hemispherically symmetric at the low latitudes, while that of the annual cycles show larger amplitudes in the northern hemisphere. The diagnosed 11-yr, or solar cycle, max minus min, water vapor values are of the order of several percent at 0.2 hPa to about 23% at 0.01 hPa. The solar cycle terms have larger values in the northern than in the southern hemisphere, particularly in the middle mesosphere, and the associated linear trend terms are anomalously large in the same region. Those anomalies are due, at least in part, to the fact that the amplitudes of the seasonal cycles were varying at northern mid latitudes during 1991-2005, while the corresponding seasonal terms of the MLR model do not allow for that possibility. Although the 11-yr variation in water vapor is essentially hemispherically-symmetric and anti-phased with the solar cycle flux near 0.01 hPa, the concurrent temperature variations produce slightly colder conditions at the northern high latitudes at solar minimum. It is concluded that this temperature difference is most likely the reason for the greater occurrence of polar mesospheric clouds at the northern versus the southern high latitudes at solar minimum during the HALOE time period. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26569108','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26569108">Strategic Grassland Bird Conservation throughout the Annual Cycle: Linking Policy Alternatives, Landowner Decisions, and Biological Population Outcomes.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Drum, Ryan G; Ribic, Christine A; Koch, Katie; Lonsdorf, Eric; Grant, Evan; Ahlering, Marissa; Barnhill, Laurel; Dailey, Thomas; Lor, Socheata; Mueller, Connie; Pavlacky, David C; Rideout, Catherine; Sample, David 2015-01-01 Grassland bird habitat has declined substantially in the United States. Remaining grasslands are increasingly fragmented, mostly privately owned, and vary greatly in terms of habitat quality and protection status. A coordinated strategic response for grassland bird conservation is difficult, largely due to the scope and complexity of the problem, further compounded by biological, sociological, and economic uncertainties. We describe the results from a collaborative Structured Decision Making (SDM) workshop focused on linking social and economic drivers of landscape change to grassland bird population outcomes. We identified and evaluated alternative strategies for grassland bird conservation using a series of rapid prototype models. We modeled change in grassland and agriculture cover in hypothetical landscapes resulting from different landowner decisions in response to alternative socio-economic conservation policy decisions. Resulting changes in land cover at all three stages of the annual cycle (breeding, wintering, and migration) were used to estimate changes in grassland bird populations. Our results suggest that successful grassland bird conservation may depend upon linkages with ecosystem services on working agricultural lands and grassland-based marketing campaigns to engage the public. With further development, spatial models that link landowner decisions with biological outcomes can be essential tools for making conservation policy decisions. A coordinated non-traditional partnership will likely be necessary to clearly understand and systematically respond to the many conservation challenges facing grassland birds. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4646652','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4646652">Strategic Grassland Bird Conservation throughout the Annual Cycle: Linking Policy Alternatives, Landowner Decisions, and Biological Population Outcomes</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> Drum, Ryan G.; Ribic, Christine A.; Koch, Katie; Lonsdorf, Eric; Grant, Evan; Ahlering, Marissa; Barnhill, Laurel; Dailey, Thomas; Lor, Socheata; Mueller, Connie; Pavlacky, David C.; Rideout, Catherine; Sample, David 2015-01-01 Grassland bird habitat has declined substantially in the United States. Remaining grasslands are increasingly fragmented, mostly privately owned, and vary greatly in terms of habitat quality and protection status. A coordinated strategic response for grassland bird conservation is difficult, largely due to the scope and complexity of the problem, further compounded by biological, sociological, and economic uncertainties. We describe the results from a collaborative Structured Decision Making (SDM) workshop focused on linking social and economic drivers of landscape change to grassland bird population outcomes. We identified and evaluated alternative strategies for grassland bird conservation using a series of rapid prototype models. We modeled change in grassland and agriculture cover in hypothetical landscapes resulting from different landowner decisions in response to alternative socio-economic conservation policy decisions. Resulting changes in land cover at all three stages of the annual cycle (breeding, wintering, and migration) were used to estimate changes in grassland bird populations. Our results suggest that successful grassland bird conservation may depend upon linkages with ecosystem services on working agricultural lands and grassland-based marketing campaigns to engage the public. With further development, spatial models that link landowner decisions with biological outcomes can be essential tools for making conservation policy decisions. A coordinated non-traditional partnership will likely be necessary to clearly understand and systematically respond to the many conservation challenges facing grassland birds. PMID:26569108 </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70173532','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70173532">Strategic Grassland Bird Conservation throughout the annual cycle: Linking policy alternatives, landowner decisions, and biological population outcomes</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Drum, Ryan G.; Ribic, Christine; Koch, Katie; Lonsdorf, Eric V.; Grant, Edward C.; Ahlering, Marissa; Barnhill, Laurel; Dailey, Thomas; Lor, Socheata; Mueller, Connie; Pavlacky, D.C.; Rideout, Catherine; Sample, David W. 2015-01-01 Grassland bird habitat has declined substantially in the United States. Remaining grasslands are increasingly fragmented, mostly privately owned, and vary greatly in terms of habitat quality and protection status. A coordinated strategic response for grassland bird conservation is difficult, largely due to the scope and complexity of the problem, further compounded by biological, sociological, and economic uncertainties. We describe the results from a collaborative Structured Decision Making (SDM) workshop focused on linking social and economic drivers of landscape change to grassland bird population outcomes. We identified and evaluated alternative strategies for grassland bird conservation using a series of rapid prototype models. We modeled change in grassland and agriculture cover in hypothetical landscapes resulting from different landowner decisions in response to alternative socio-economic conservation policy decisions. Resulting changes in land cover at all three stages of the annual cycle (breeding, wintering, and migration) were used to estimate changes in grassland bird populations. Our results suggest that successful grassland bird conservation may depend upon linkages with ecosystem services on working agricultural lands and grassland-based marketing campaigns to engage the public. With further development, spatial models that link landowner decisions with biological outcomes can be essential tools for making conservation policy decisions. A coordinated non-traditional partnership will likely be necessary to clearly understand and systematically respond to the many conservation challenges facing grassland birds. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..1212851B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..1212851B">Establishing a baseline precipitation and temperature regime for the Guianas from observations and reanalysis data</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Bovolo, C. Isabella; Pereira, Ryan; Parkin, Geoff; Wagner, Thomas 2010-05-01 annual average spatial correlations are examined between modelled ERA40 and observed time series comparing the seasonal cycles and the yearly, monthly and monthly anomaly time series. This is to evaluate if the reanalysis data correctly reproduces the areally averaged observed mean annual precipitation, interannual variability and seasonal precipitation cycle over the region. Results show that reanalysis precipitation for the region compares favourably with areally averaged observations where available, although the model underestimates precipitation in some zones of higher elevation. Also ERA40 data is slightly positively biased along the coast and negatively biased inland. Comparisons between observed and modelled data show that although correlations of annual time series are low (<0.6), correlations of monthly time series reach 0.8 demonstrating that the model captures much of the seasonal variation in precipitation. However correlations between monthly precipitation anomalies, where the averaged seasonal cycle has been removed from the comparison, are lower (< 0.6). As precipitation observations are not assimilated into the reanalysis these results provide a good validation of model performance. The seasonal cycle of precipitation is found to be highly variable across the region. Two wet-seasons (June and December) occur in northern Guyana which relate to the twice yearly passage of the inter-tropical convergence zone whereas a single wet season (April-August) occurs in the savannah zone, which stretches from Venezuela through the southern third of Guyana. The climate transition zone lies slightly north of the distinctive forest-savannah boundary which suggests that the boundary may be highly sensitive to future alterations in climate, such as those due to climate change or deforestation. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRC..122.1608P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRC..122.1608P">The ocean mixed layer under Southern Ocean sea-ice: Seasonal cycle and forcing</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Pellichero, Violaine; Sallée, Jean-Baptiste; Schmidtko, Sunke; Roquet, Fabien; Charrassin, Jean-Benoît 2017-02-01 The oceanic mixed layer is the gateway for the exchanges between the atmosphere and the ocean; in this layer, all hydrographic ocean properties are set for months to millennia. A vast area of the Southern Ocean is seasonally capped by sea-ice, which alters the characteristics of the ocean mixed layer. The interaction between the ocean mixed layer and sea-ice plays a key role for water mass transformation, the carbon cycle, sea-ice dynamics, and ultimately for the climate as a whole. However, the structure and characteristics of the under-ice mixed layer are poorly understood due to the sparseness of in situ observations and measurements. In this study, we combine distinct sources of observations to overcome this lack in our understanding of the polar regions. Working with elephant seal-derived, ship-based, and Argo float observations, we describe the seasonal cycle of the ocean mixed-layer characteristics and stability of the ocean mixed layer over the Southern Ocean and specifically under sea-ice. Mixed-layer heat and freshwater budgets are used to investigate the main forcing mechanisms of the mixed-layer seasonal cycle. The seasonal variability of sea surface salinity and temperature are primarily driven by surface processes, dominated by sea-ice freshwater flux for the salt budget and by air-sea flux for the heat budget. Ekman advection, vertical diffusivity, and vertical entrainment play only secondary roles. Our results suggest that changes in regional sea-ice distribution and annual duration, as currently observed, widely affect the buoyancy budget of the underlying mixed layer, and impact large-scale water mass formation and transformation with far reaching consequences for ocean ventilation. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910023242&hterms=raman+KOH&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Draman%2BKOH','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910023242&hterms=raman+KOH&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Draman%2BKOH">Raman spectral observation of a new phase observed in nickel electrodes cycled to failure</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Loyselle, Patricia L.; Shan, X.; Cornilsen, B. C.; Reid, Margaret A. 1991-01-01 A new phase is reported in nickel electrodes from Ni/H2 boilerplate cells which were cycled to failure in electrolyte of variable KOH concentration (21 to 36 percent). Raman spectra clearly show the presence of this phase, and these spectra have been used to estimate the amounts present on these electrodes. Ten of 12 electrodes examined contain this new phase. The cycle life at higher KOH concentrations (31 and 36 percent) was greatly reduced, and nickel electrodes from these cells exhibited extensive amounts of this new phase. The presence of this new phase correlates with cell failure defined by low end of discharge voltages. It is proposed that the lowered capacity and failure of these electrodes was caused by loss of active mass and formation of a phase with reduced electrochemical activity. These results indicate that formation of the new phase is accelerated at higher KOH concentrations. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMGC21E0990G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMGC21E0990G">How well do CMIP5 Climate Models Reproduce the Hydrologic Cycle of the Colorado River Basin?</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Gautam, J.; Mascaro, G. 2017-12-01 The Colorado River, which is the primary source of water for nearly 40 million people in the arid Southwestern states of the United States, has been experiencing an extended drought since 2000, which has led to a significant reduction in water supply. As the water demands increase, one of the major challenges for water management in the region has been the quantification of uncertainties associated with streamflow predictions in the Colorado River Basin (CRB) under potential changes of future climate. Hence, testing the reliability of model predictions in the CRB is critical in addressing this challenge. In this study, we evaluated the performances of 17 General Circulation Models (GCMs) from the Coupled Model Intercomparison Project Phase Five (CMIP5) and 4 Regional Climate Models (RCMs) in reproducing the statistical properties of the hydrologic cycle in the CRB. We evaluated the water balance components at four nested sub-basins along with the inter-annual and intra-annual changes of precipitation (P), evaporation (E), runoff (R) and temperature (T) from 1979 to 2005. Most of the models captured the net water balance fairly well in the most-upstream basin but simulated a weak hydrological cycle in the evaporation channel at the downstream locations. The simulated monthly variability of P had different patterns, with correlation coefficients ranging from -0.6 to 0.8 depending on the sub-basin and the models from same parent institution clustering together. Apart from the most-upstream sub-basin where the models were mainly characterized by a negative seasonal bias in SON (of up to -50%), most of them had a positive bias in all seasons (of up to +260%) in the other three sub-basins. The models, however, captured the monthly variability of T well at all sites with small inter-model variabilities and a relatively similar range of bias (-7 °C to +5 °C) across all seasons. Mann-Kendall test was applied to the annual P and T time-series where majority of the models </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.C41E0729M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.C41E0729M">FirnCover: Observations on the evolution of firn compaction, firn temperatures and porosity in the interior of the Greenland ice sheet</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> MacFerrin, M. J.; Stevens, C.; Colgan, W. T.; Waddington, E. D.; Abdalati, W. 2016-12-01 As Greenland warms, increasing amounts of summer meltwater are changing the behavior of snow and firn in high-elevation regions of the ice. The Firn Compaction Verification and Reconnaissance (FirnCover) network in Greenland provides real-time measurements of compaction, firn temperatures and other observations across Greenland's interior, ranging from regions of dry snow to areas of heavy melt and refreezing. Here we present results from FirnCover measurements that illustrate a distinct shift in seasonal thermal cycles within the firn in regions with increased melt, whereby seasonal temperature cycles are both enhanced (in magnitude) and delayed (in timing) in response to increased latent heat from refreezing. Seasonal firn-compaction rates correlate strongly with these thermal cycles. Comparisons to historical cores illustrate that despite warming temperatures, compaction rates have not changed substantially in dry-snow regions of Greenland where meltwater has not yet been generated to a significant degree. In regions with enhanced melt and refreezing, historical comparisons indicate annual rates of compaction have dramatically increased in recent decades. In regions where near-surface firn has exceeded a critical saturation cutoff, water has begun to run off downhill rather than refreezing in years of high melt. In such regions these seasonal thermal cycles (and corresponding compaction rates) are greatly reduced due to the isolation of deep firn from meltwater above. We present current observations that suggest such saturated regions are rapidly expanding in Greenland in response to warming and enhanced summer melt. We outline the strong implications these observations have for interpreting Greenland's seasonal and inter-annual mass balance from airborne and satellite altimetry, as well as for the future evolution of runoff from Greenland's interior in a warming climate. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930013949','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930013949">Annual and longitudinal variations of the Pacific North Equatorial Countercurrent</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Lolk, Nina K. 1992-01-01 The climatological annual cycle of the Pacific North Equatorial Countercurrent (NECC) simulated by an ocean general circulation model (OGCM) was studied. The longitudinal variation of transports, degree of geostrophy, and the relationship between Ekman pumping and vertical displacement of the thermocline were emphasized. The longitudinal variation was explored using six sections along 150 deg E, 180 deg, 160 deg W, 140 deg W, 125 deg W, and 110 deg W. A primitive equation OGCM of the Pacific Ocean was run for three years and the fields used were from the third year. The fields consisted of zonal, meridional, and vertical current components and temperature and salinity averaged every three days. The model was forced with the Hellerman and Rosenstein climatological wind stress. The mean annual eastward transport (19.9 Sv) was largest at 160 deg W. The maximum-current boundaries along 160 deg W were 9.2 deg N (1.0 deg), 5.1 deg N (1.1 deg), and 187 m (90.6 m). The annual-cycle amplitude of the NECC was greatest between 160 deg W and 140 deg W. Although the NECC is geostrophic to the first order, deviations from geostrophy were found in the boreal spring and summer near the southern boundary and near the surface. Meridional local acceleration played a role between 3 deg N-5 deg N. </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active">18</li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active">19</li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20160013894&hterms=cycles&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dcycles','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20160013894&hterms=cycles&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dcycles">Comparison of OMI NO2 Observations and Their Seasonal and Weekly Cycles with Ground-Based Measurements in Helsinki</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Ialongo, Iolanda; Herman, Jay; Krotkov, Nick; Lamsal, Lok; Boersma, Folkert; Hovila, Jari; Tamminen, Johanna 2016-01-01 We present the comparison of satellite-based OMI (Ozone Monitoring Instrument) NO2 products with ground-based observations in Helsinki. OMI NO2 total columns, available from standard product (SP) and DOMINO algorithm, are compared with the measurements performed by the Pandora spectrometer in Helsinki in 2012. The relative difference between Pandora 21 and OMI SP retrievals is 4 and 6 for clear sky and all sky conditions, respectively. DOMINO NO2 retrievals showed slightly lower total columns with median differences about 5 and 14 for clear sky and all sky conditions, respectively. Large differences often correspond to cloudy autumn-winter days with solar zenith angles above 65. Nevertheless, the differences remain within the retrieval uncertainties. Furthermore, the weekly and seasonal cycles from OMI, Pandora and NO2 surface concentrations are compared. Both satellite- and ground-based data show a similar weekly cycle, with lower NO2 levels during the weekend compared to the weekdays as result of reduced emissions from traffic and industrial activities. Also the seasonal cycle shows a similar behavior, even though the results are affected by the fact that most of the data are available during spring-summer because of cloud cover in other seasons. This is one of few works in which OMI NO2 retrievals are evaluated in an urban site at high latitudes (60N). Despite the city of Helsinki having relatively small pollution sources, OMI retrievals have proved to be able to describe air quality features and variability similar to surface observations. This adds confidence in using satellite observations for air quality monitoring also at high latitudes. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED427610.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED427610.pdf">The Life Cycle of Academic Management Fads. ASHE Annual Meeting Paper.</a> <a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a> Birnbaum, Robert This study reviewed the literature to trace the evolution and life cycles of seven management techniques related to higher education. The seven case studies involved analysis of a selected sample of periodical, monograph, and technical literature from 1960 to the present. The literature base on each management technique was reviewed in reference… </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008JGRD..11310105L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008JGRD..11310105L">Assessment of surface air temperature over the Arctic Ocean in reanalysis and IPCC AR4 model simulations with IABP/POLES observations</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Liu, Jiping; Zhang, Zhanhai; Hu, Yongyun; Chen, Liqi; Dai, Yongjiu; Ren, Xiaobo 2008-05-01 The surface air temperature (SAT) over the Arctic Ocean in reanalyses and global climate model simulations was assessed using the International Arctic Buoy Programme/Polar Exchange at the Sea Surface (IABP/POLES) observations for the period 1979-1999. The reanalyses, including the National Centers for Environmental Prediction Reanalysis II (NCEP2) and European Centre for Medium-Range Weather Forecast 40-year Reanalysis (ERA40), show encouraging agreement with the IABP/POLES observations, although some spatiotemporal discrepancies are noteworthy. The reanalyses have warm annual mean biases and underestimate the observed interannual SAT variability in summer. Additionally, NCEP2 shows an excessive warming trend. Most model simulations (coordinated by the International Panel on Climate Change for its Fourth Assessment Report) reproduce the annual mean, seasonal cycle, and trend of the observed SAT reasonably well, particularly the multi-model ensemble mean. However, large discrepancies are found. Some models have the annual mean SAT biases far exceeding the standard deviation of the observed interannul SAT variability and the across-model standard deviation. Spatially, the largest inter-model variance of the annual mean SAT is found over the North Pole, Greenland Sea, Barents Sea and Baffin Bay. Seasonally, a large spread of the simulated SAT among the models is found in winter. The models show interannual variability and decadal trend of various amplitudes, and can not capture the observed dominant SAT mode variability and cooling trend in winter. Further discussions of the possible attributions to the identified SAT errors for some models suggest that the model's performance in the sea ice simulation is an important factor. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.B41C1952U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.B41C1952U">Increased resiliency and activity of microbial mediated carbon cycling enzymes in diversified bioenergy cropping systems</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Upton, R.; Bach, E.; Hofmockel, K. S. 2017-12-01 Microbes are mediators of soil carbon (C) and are influenced in membership and activity by nitrogen (N) fertilization and inter-annual abiotic factors. Microbial communities and their extracellular enzyme activities (EEA) are important parameters that influence ecosystem C cycling properties and are often included in microbial explicit C cycling models. In an effort to generate model relevant, empirical findings, we investigated how both microbial community structure and C degrading enzyme activity are influenced by inter-annual variability and N inputs in bioenergy crops. Our study was performed at the Comparison of Biofuel Systems field-site from 2011 to 2014, in three bioenergy cropping systems, continuous corn (CC) and two restored prairies, both fertilized (FP) and unfertilized (P). We hypothesized microbial community structure would diverge during the prairie restoration, leading to changes in C cycling enzymes over time. Using a sequencing approach (16S and ITS) we determined the bacterial and fungal community structure response to the cropping system, fertilization, and inter-annual variability. Additionally, we used EEA of β-glucosidase, cellobiohydrolase, and β-xylosidase to determine inter-annual and ecosystem impacts on microbial activity. Our results show cropping system was a main effect for microbial community structure, with corn diverging from both prairies to be less diverse. Inter-annual changes showed that a drought occurring in 2012 significantly impacted microbial community structure in both the P and CC, decreasing microbial richness. However, FP increased in microbial richness, suggesting the application of N increased resiliency to drought. Similarly, the only year in which C cycling enzymes were impacted by ecosystem was 2012, with FP supporting higher potential enzymatic activity then CC and P. The highest EEA across all ecosystems occurred in 2014, suggesting the continued root biomass and litter build-up in this no till system </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25353240','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25353240">Radiation exposure of German aircraft crews under the impact of solar cycle 23 and airline business factors.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Frasch, Gerhard; Kammerer, Lothar; Karofsky, Ralf; Schlosser, Andrea; Stegemann, Ralf 2014-12-01 The exposure of German aircraft crews to cosmic radiation varies both with solar activity and operational factors of airline business. Data come from the German central dose registry and cover monthly exposures of up to 37,000 German aircraft crewmembers that were under official monitoring. During the years 2004 to 2009 of solar cycle 23 (i.e., in the decreasing phase of solar activity), the annual doses of German aircraft crews increased by an average of 20%. Decreasing solar activity allows more galactic radiation to reach the atmosphere, increasing high-altitude doses. The rise results mainly from the less effective protection from the solar wind but also from airline business factors. Both cockpit and cabin personnel differ in age-dependent professional and social status. This status determines substantially the annual effective dose: younger cabin personnel and the elder pilots generally receive higher annual doses than their counterparts. They also receive larger increases in their annual dose when the solar activity decreases. The doses under this combined influence of solar activity and airline business factors result in a maximum of exposure for German aircrews for this solar cycle. With the increasing solar activity of the current solar cycle 24, the doses are expected to decrease again. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.B43I..03F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.B43I..03F">Initializing carbon cycle predictions from the Community Land Model by assimilating global biomass observations</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Fox, A. M.; Hoar, T. J.; Smith, W. K.; Moore, D. J. 2017-12-01 The locations and longevity of terrestrial carbon sinks remain uncertain, however it is clear that in order to predict long-term climate changes the role of the biosphere in surface energy and carbon balance must be understood and incorporated into earth system models (ESMs). Aboveground biomass, the amount of carbon stored in vegetation, is a key component of the terrestrial carbon cycle, representing the balance of uptake through gross primary productivity (GPP), losses from respiration, senescence and mortality over hundreds of years. The best predictions of current and future land-atmosphere fluxes are likely from the integration of process-based knowledge contained in models and information from observations of changes in carbon stocks using data assimilation (DA). By exploiting long times series, it is possible to accurately detect variability and change in carbon cycle dynamics through monitoring ecosystem states, for example biomass derived from vegetation optical depth (VOD), and use this information to initialize models before making predictions. To make maximum use of information about the current state of global ecosystems when using models we have developed a system that combines the Community Land Model (CLM) with the Data Assimilation Research Testbed (DART), a community tool for ensemble DA. This DA system is highly innovative in its complexity, completeness and capabilities. Here we described a series of activities, using both Observation System Simulation Experiments (OSSEs) and real observations, that have allowed us to quantify the potential impact of assimilating VOD data into CLM-DART on future land-atmosphere fluxes. VOD data are particularly suitable to use in this activity due to their long temporal coverage and appropriate scale when combined with CLM, but their absolute values rely on many assumptions. Therefore, we have had to assess the implications of the VOD retrieval algorithms, with an emphasis on detecting uncertainty due to </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.B51D0330P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.B51D0330P">Using CarbonTracker carbon flux estimates to improve a terrestrial carbon cycle model</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Peters, W.; Krol, M.; Miller, J. B.; Tans, P. P.; Carvalhais, N.; Schaefer, K. 2009-12-01 Estimates of net ecosystem exchange (NEE) from NOAA’s CarbonTracker CO2 data assimilation system show patterns of annual net uptake not represented in most terrestrial carbon cycle models. This is mainly because such models lack information on the land-use history of individual ecosystems, which is the main driver of long-term mean carbon exchange. Instead, they assume the biosphere to be in steady-state, with annual gross photosynthesis equalling ecosystem respiration everywhere. This limits their use in interpreting observations of carbon dynamics such as with eddy-covariance techniques or through atmospheric CO2 records. We have implemented a method that takes the long-term mean NEE estimates from CarbonTracker to derive the size of the dominant carbon pool in each ecosystem of the SIBCASA biosphere model. With the new pool sizes, the SIBCASA model is no longer in steady-state and reproduces annual carbon uptake patterns from CarbonTracker. We will show that the non steady-state SIBCASA model is not only much more consistent with the atmospheric CO2 record, but also with independent data on standing wood biomass and forest age from the Forest Inventory and Analysis (FIA) Program of the U.S. Forest Service. Four years of CarbonTracker NEE are needed to reliably derive a long term mean for this process, and we use three other years from CarbonTracker to evaluate the non steady state SIBCASA NEE. We will furthermore show that the non steady-state SIBCASA NEE is a much better first-guess for the CarbonTracker data assimilation process, allowing more confidence in its final NEE estimate, and reducing a systematic bias in CarbonTracker modeled atmospheric CO2. This overcomes a long standing issue in inverse modeling, and opens the way for further assessment and improvement of carbon cycle models such as SIBCASA. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22661454-tracking-solar-cycle-through-ibex-observations-energetic-neutral-atom-flux-variations-heliospheric-poles','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22661454-tracking-solar-cycle-through-ibex-observations-energetic-neutral-atom-flux-variations-heliospheric-poles">TRACKING THE SOLAR CYCLE THROUGH IBEX OBSERVATIONS OF ENERGETIC NEUTRAL ATOM FLUX VARIATIONS AT THE HELIOSPHERIC POLES</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Reisenfeld, D. B.; Janzen, P. H.; Bzowski, M., E-mail: dan.reisenfeld@umontana.edu, E-mail: paul.janzen@umontana.edu, E-mail: bzowski@cbk.waw.pl With seven years of Interstellar Boundary Explorer ( IBEX ) observations, from 2009 to 2015, we can now trace the time evolution of heliospheric energetic neutral atoms (ENAs) through over half a solar cycle. At the north and south ecliptic poles, the spacecraft attitude allows for continuous coverage of the ENA flux; thus, signal from these regions has much higher statistical accuracy and time resolution than anywhere else in the sky. By comparing the solar wind dynamic pressure measured at 1 au with the heliosheath plasma pressure derived from the observed ENA fluxes, we show that the heliosheath pressure measuredmore » at the poles correlates well with the solar cycle. The analysis requires time-shifting the ENA measurements to account for the travel time out and back from the heliosheath, which allows us to estimate the scale size of the heliosphere in the polar directions. We arrive at an estimated distance to the center of the ENA source region in the north of 220 au and in the south a distance of 190 au. We also find a good correlation between the solar cycle and the ENA energy spectra at the poles. In particular, the ENA flux for the highest IBEX energy channel (4.3 keV) is quite closely correlated with the areas of the polar coronal holes, in both the north and south, consistent with the notion that polar ENAs at this energy originate from pickup ions of the very high speed wind (∼700 km s{sup −1}) that emanates from polar coronal holes.« less </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22126712-hemispheric-asymmetries-polar-solar-wind-observed-ulysses-near-minima-solar-cycles','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22126712-hemispheric-asymmetries-polar-solar-wind-observed-ulysses-near-minima-solar-cycles">HEMISPHERIC ASYMMETRIES IN THE POLAR SOLAR WIND OBSERVED BY ULYSSES NEAR THE MINIMA OF SOLAR CYCLES 22 AND 23</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Ebert, R. W.; Dayeh, M. A.; Desai, M. I. 2013-05-10 We examined solar wind plasma and interplanetary magnetic field (IMF) observations from Ulysses' first and third orbits to study hemispheric differences in the properties of the solar wind and IMF originating from the Sun's large polar coronal holes (PCHs) during the declining and minimum phase of solar cycles 22 and 23. We identified hemispheric asymmetries in several parameters, most notably {approx}15%-30% south-to-north differences in averages for the solar wind density, mass flux, dynamic pressure, and energy flux and the radial and total IMF magnitudes. These differences were driven by relatively larger, more variable solar wind density and radial IMF betweenmore » {approx}36 Degree-Sign S-60 Degree-Sign S during the declining phase of solar cycles 22 and 23. These observations indicate either a hemispheric asymmetry in the PCH output during the declining and minimum phase of solar cycles 22 and 23 with the southern hemisphere being more active than its northern counterpart, or a solar cycle effect where the PCH output in both hemispheres is enhanced during periods of higher solar activity. We also report a strong linear correlation between these solar wind and IMF parameters, including the periods of enhanced PCH output, that highlight the connection between the solar wind mass and energy output and the Sun's magnetic field. That these enhancements were not matched by similar sized variations in solar wind speed points to the mass and energy responsible for these increases being added to the solar wind while its flow was subsonic.« less </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018SoPh..293...18M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018SoPh..293...18M">On the Performance of Multi-Instrument Solar Flare Observations During Solar Cycle 24</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Milligan, Ryan O.; Ireland, Jack 2018-02-01 observations for solar-flare research is discussed with respect to instruments projected to begin operations during Solar Cycle 25, such as the Daniel K. Inouye Solar Telescope, Solar Orbiter, and Parker Solar Probe. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22173463','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22173463">Generation separation in simple structured life cycles: models and 48 years of field data on a tea tortrix moth.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Yamanaka, Takehiko; Nelson, William A; Uchimura, Koichiro; Bjørnstad, Ottar N 2012-01-01 Population cycles have fascinated ecologists since the early nineteenth century, and the dynamics of insect populations have been central to understanding the intrinsic and extrinsic biological processes responsible for these cycles. We analyzed an extraordinary long-term data set (every 5 days for 48 years) of a tea tortrix moth (Adoxophyes honmai) that exhibits two dominant cycles: an annual cycle with a conspicuous pattern of four or five single-generation cycles superimposed on it. General theory offers several candidate mechanisms for generation cycles. To evaluate these, we construct and parameterize a series of temperature-dependent, stage-structured models that include intraspecific competition, parasitism, mate-finding Allee effects, and adult senescence, all in the context of a seasonal environment. By comparing the observed dynamics with predictions from the models, we find that even weak larval competition in the presence of seasonal temperature forcing predicts the two cycles accurately. None of the other mechanisms predicts the dynamics. Detailed dissection of the results shows that a short reproductive life span and differential winter mortality among stages are the additional life-cycle characteristics that permit the sustained cycles. Our general modeling approach is applicable to a wide range of organisms with temperature-dependent life histories and is likely to prove particularly useful in temperate systems where insect pest outbreaks are both density and temperature dependent. © 2011 by The University of Chicago. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PASA...35....2V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PASA...35....2V">Probing the Baryon Cycle of Galaxies with SPICA Mid- and Far-Infrared Observations</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> van der Tak, F. F. S.; Madden, S. C.; Roelfsema, P.; Armus, L.; Baes, M.; Bernard-Salas, J.; Bolatto, A.; Bontemps, S.; Bot, C.; Bradford, C. M.; Braine, J.; Ciesla, L.; Clements, D.; Cormier, D.; Fernández-Ontiveros, J. A.; Galliano, F.; Giard, M.; Gomez, H.; González-Alfonso, E.; Herpin, F.; Johnstone, D.; Jones, A.; Kaneda, H.; Kemper, F.; Lebouteiller, V.; De Looze, I.; Matsuura, M.; Nakagawa, T.; Onaka, T.; Pérez-González, P.; Shipman, R.; Spinoglio, L. 2018-01-01 The SPICA mid- and far-infrared telescope will address fundamental issues in our understanding of star formation and ISM physics in galaxies. A particular hallmark of SPICA is the outstanding sensitivity enabled by the cold telescope, optimised detectors, and wide instantaneous bandwidth throughout the mid- and far-infrared. The spectroscopic, imaging, and polarimetric observations that SPICA will be able to collect will help in clarifying the complex physical mechanisms which underlie the baryon cycle of galaxies. In particular, (i) the access to a large suite of atomic and ionic fine-structure lines for large samples of galaxies will shed light on the origin of the observed spread in star-formation rates within and between galaxies, (ii) observations of HD rotational lines (out to 10 Mpc) and fine structure lines such as [C ii] 158 μm (out to 100 Mpc) will clarify the main reservoirs of interstellar matter in galaxies, including phases where CO does not emit, (iii) far-infrared spectroscopy of dust and ice features will address uncertainties in the mass and composition of dust in galaxies, and the contributions of supernovae to the interstellar dust budget will be quantified by photometry and monitoring of supernova remnants in nearby galaxies, (iv) observations of far-infrared cooling lines such as [O i] 63 μm from star-forming molecular clouds in our Galaxy will evaluate the importance of shocks to dissipate turbulent energy. The paper concludes with requirements for the telescope and instruments, and recommendations for the observing strategy. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20000024892&hterms=Evaporation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DEvaporation','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20000024892&hterms=Evaporation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DEvaporation">Further Evaluation of an Emperical Equation for Annual Total Evaporation</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Choudhury, Bhaskar J. 1999-01-01 An empirical equation for annual total evaporation based on annual precipitation and net radiation was found to provide evaporation within 10% of the observed values at seven locations within temperate and tropical regions, but it overestimated evaporation by 90% at one location within the tundra region. A synthesis of observations at two other locations within the tundra region gives overestimates of about 65%. A general analysis of observed precipitation, net radiation, and runoff within the tundra region shows that the empirical equation is generally biased to overestimate annual evaporation within the tundra region. A theoretical analysis is being done to understand the reason behind this bias. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19950004187','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19950004187">Annual variability of ozone along alpine hillsides</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Putz, Erich; Kosmus, Walter 1994-01-01 Over a period of more than two years (March 1989 till June 1991) ozone and nitrogen dioxide have been monitored along twelve alpine hillsides in the Austrian alps. The profiles had a height-resolution of 100 m and cover a range between 400 m and 1800 m asl, that is 100 m to 1100 m above the bottom of the valleys. They were situated in remote rural areas as well as in the vicinity of polluted urban and industrial areas. Both trace gases were monitored by means of integral chemical (SAM-surface active monitor) methods with a measuring cycle of two weeks. The concentration of ozone exhibits a substantial annual variation over the entire height range. In summer, highest ozone levels are observed near the ground and at the top of the mountains, whereas in winter the maxima are found mainly in the crest regions. The overall ozone burden shows a relative maximum near the temperature inversion layer in the valleys and an absolute maximum at the crest. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70034990','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70034990">Population cycles are highly correlated over long time series and large spatial scales in two unrelated species: Greater sage-grouse and cottontail rabbits</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Fedy, B.C.; Doherty, K.E. 2011-01-01 Animal species across multiple taxa demonstrate multi-annual population cycles, which have long been of interest to ecologists. Correlated population cycles between species that do not share a predator-prey relationship are particularly intriguing and challenging to explain. We investigated annual population trends of greater sage-grouse (Centrocercus urophasianus) and cottontail rabbits (Sylvilagus sp.) across Wyoming to explore the possibility of correlations between unrelated species, over multiple cycles, very large spatial areas, and relatively southern latitudes in terms of cycling species. We analyzed sage-grouse lek counts and annual hunter harvest indices from 1982 to 2007. We show that greater sage-grouse, currently listed as warranted but precluded under the US Endangered Species Act, and cottontails have highly correlated cycles (r = 0. 77). We explore possible mechanistic hypotheses to explain the synchronous population cycles. Our research highlights the importance of control populations in both adaptive management and impact studies. Furthermore, we demonstrate the functional value of these indices (lek counts and hunter harvest) for tracking broad-scale fluctuations in the species. This level of highly correlated long-term cycling has not previously been documented between two non-related species, over a long time-series, very large spatial scale, and within more southern latitudes. ?? 2010 US Government. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18048294','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18048294">Control of the annual cycle in birds: endocrine constraints and plasticity in response to ecological variability.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Dawson, Alistair 2008-05-12 This paper reviews information from ecological and physiological studies to assess how extrinsic factors can modulate intrinsic physiological processes. The annual cycle of birds is made up of a sequence of life-history stages: breeding, moult and migration. Each stage has evolved to occur at the optimum time and to last for the whole duration of time available. Some species have predictable breeding seasons, others are more flexible and some breed opportunistically in response to unpredictable food availability. Photoperiod is the principal environmental cue used to time each stage, allowing birds to adapt their physiology in advance of predictable environmental changes. Physiological (neuroendocrine and endocrine) plasticity allows non-photoperiodic cues to modulate timing to enable individuals to cope with, and benefit from, short-term environmental variability. Although the timing and duration of the period of full gonadal maturation is principally controlled by photoperiod, non-photoperiodic cues, such as temperature, rainfall or food availability, could potentially modulate the exact time of breeding either by fine-tuning the time of egg-laying within the period of full gonadal maturity or, more fundamentally, by modulating gonadal maturation and/or regression. The timing of gonadal regression affects the time of the start of moult, which in turn may affect the duration of the moult. There are many areas of uncertainty. Future integrated studies are required to assess the scope for flexibility in life-history strategies as this will have a critical bearing on whether birds can adapt sufficiently rapidly to anthropogenic environmental changes, in particular climate change. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/6896176','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/6896176">Environmental Sciences Division annual progress report for period ending September 30, 1983</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Not Available 1984-04-01 This annual report summarizes activities in the Aquatic Ecology, Earth Sciences, Environmental Analyses, and Terrestrial Ecology sections, as well as in the Fossil Energy, Biomass, Low-Level Waste Research and Management, and Global Carbon Cycle Programs. Separate abstracts have been prepared for each section. (ACR) </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014GBioC..28..757P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014GBioC..28..757P">Characterizing the annual cycle of African dust transport to the Caribbean Basin and South America and its impact on the environment and air quality</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Prospero, Joseph M.; Collard, François-Xavier; Molinié, Jack; Jeannot, Alexis 2014-07-01 Decades of aerosol measurements on Barbados have yielded a detailed picture of African mineral dust transport to the Caribbean Basin that shows a strong seasonal cycle with a maximum in boreal summer and a minimum in winter. Satellite aerosol products suggest that in spring, there is a comparable transport to northeastern South America. Here we characterize the complete annual cycle of dust transport to the western Atlantic by linking the Barbados record to multiyear records of airborne particulate matter less than 10 µm diameter (PM10) measured in air quality programs at Cayenne (French Guiana) and Guadeloupe. Comparisons of PM10 at these sites with concurrent dust measurements at Barbados demonstrate that high PM10 levels are almost entirely due to dust. Cayenne PM10 peaks in spring in a cycle which is consistent with satellite aerosol optical depth and suggests that the Sahel is the dominant source. The persistent transport of dust during much of the year could impact a wide range of environmental processes over a broad region that extends from the southern United States to the Amazon Basin. Finally, the average 24 h PM10 concentrations at Cayenne and Guadeloupe frequently exceed the World Health Organization air quality guideline. Thus soil dust PM10 could be a significant, but generally unrecognized, health factor at western Atlantic sites and also in other relatively remote regions affected by long-range dust from Africa. Because dust emissions and transport are highly sensitive to climate variability, climate change in coming decades could greatly affect a wide range of biogeochemical processes and human health in this region. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/56104','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/56104">Transcription through the eye of a needle: daily and annual cyclic gene expression variation in Douglas-fir needles</a> <a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a> Richard Cronn; Peter C. Dolan; Sanjuro Jogdeo; Jill L. Wegrzyn; David B. Neale; J. Bradley St. Clair; Dee R. Denver 2017-01-01 Background: Perennial growth in plants is the product of interdependent cycles of daily and annual stimuli that induce cycles of growth and dormancy. In conifers, needles are the key perennial organ that integrates daily and seasonal signals from light, temperature, and water availability. To understand the relationship between seasonal... </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1564021','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1564021">Control of annual reproductive cycle in the subtropical house sparrow (Passer domesticus): evidence for conservation of photoperiodic control mechanisms in birds</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> Trivedi, Amit K; Rani, Sangeeta; Kumar, Vinod 2006-01-01 Background In many birds, day length (=photoperiod) regulates reproductive cycle. The photoperiodic environment varies between different seasons and latitudes. As a consequence, species at different latitudes may have evolved separate photoperiodic strategies or modified them as per their adaptive need. We studied this using house sparrow as a model since it is found worldwide and is widely investigated. In particular, we examined whether photoperiodism in house sparrows (Passer domesticus) at 27°N, 81°E shared features with those exhibited by its conspecifics at high latitudes. Results Initial experiment described in the wild and captive conditions the gonad development and molt (only in captives) cycles over a 12-month period. Both male and female sparrows had similar seasonal cycles, linked with annual variations in day length; this suggested that seasonal reproduction in house sparrows was under the photoperiodic control. However, a slower testis and attenuated follicular growth among captives indicated that other (supplementary) factors are also involved in controlling the reproductive cycle. Next experiment examined if sparrows underwent seasonal variations in their response to stimulatory effects of long day lengths. When birds were transferred every month over a period of 1 year to 16 hours light:8 hours darkness (16L:8D) for 17–26 weeks, there was indeed a time-of-year effect on the growth-regression cycle of gonads. The final experiment investigated response of house sparrows to a variety of light-dark (LD) cycles. In the first set, sparrows were exposed for 31 weeks to photoperiods that were close to what they receive in between the period from sunrise to sunset at this latitude: 9L:15D (close to shortest day length in December), 12L:12D (equinox, in March and September) 15L:9D (close to longest day length in June). They underwent testicular growth and regression and molt in 12L and 15L photoperiods, but not in 9L photoperiod. In the second set </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active">19</li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active">20</li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5937139','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5937139">A Lagrangian analysis of cold cloud clusters and their life cycles with satellite observations</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> Esmaili, Rebekah Bradley; Tian, Yudong; Vila, Daniel Alejandro; Kim, Kyu-Myong 2018-01-01 Cloud movement and evolution signify the complex water and energy transport in the atmosphere-ocean-land system. Detecting, clustering, and tracking clouds as semi-coherent cluster objects enables study of their evolution which can complement climate model simulations and enhance satellite retrieval algorithms, where there are large gaps between overpasses. Using an area-overlap cluster tracking algorithm, in this study we examine the trajectories, horizontal extent, and brightness temperature variations of millions of individual cloud clusters over their lifespan, from infrared satellite observations at 30-minute, 4-km resolution, for a period of 11 years. We found that the majority of cold clouds were both small and short-lived and that their frequency and location are influenced by El Niño. More importantly, this large sample of individually tracked clouds shows their horizontal size and temperature evolution. Longer lived clusters tended to achieve their temperature and size maturity milestones at different times, while these stages often occurred simultaneously in shorter lived clusters. On average, clusters with this lag also exhibited a greater rainfall contribution than those where minimum temperature and maximum size stages occurred simultaneously. Furthermore, by examining the diurnal cycle of cluster development over Africa and the Indian subcontinent, we observed differences in the local timing of the maximum occurrence at different life cycle stages. Over land there was a strong diurnal peak in the afternoon while over the ocean there was a semi-diurnal peak composed of longer-lived clusters in the early morning hours and shorter-lived clusters in the afternoon. Building on regional specific work, this study provides a long-term, high-resolution, and global survey of object-based cloud characteristics. PMID:29744257 </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29744257','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29744257">A Lagrangian analysis of cold cloud clusters and their life cycles with satellite observations.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Esmaili, Rebekah Bradley; Tian, Yudong; Vila, Daniel Alejandro; Kim, Kyu-Myong 2016-10-16 Cloud movement and evolution signify the complex water and energy transport in the atmosphere-ocean-land system. Detecting, clustering, and tracking clouds as semi-coherent cluster objects enables study of their evolution which can complement climate model simulations and enhance satellite retrieval algorithms, where there are large gaps between overpasses. Using an area-overlap cluster tracking algorithm, in this study we examine the trajectories, horizontal extent, and brightness temperature variations of millions of individual cloud clusters over their lifespan, from infrared satellite observations at 30-minute, 4-km resolution, for a period of 11 years. We found that the majority of cold clouds were both small and short-lived and that their frequency and location are influenced by El Niño. More importantly, this large sample of individually tracked clouds shows their horizontal size and temperature evolution. Longer lived clusters tended to achieve their temperature and size maturity milestones at different times, while these stages often occurred simultaneously in shorter lived clusters. On average, clusters with this lag also exhibited a greater rainfall contribution than those where minimum temperature and maximum size stages occurred simultaneously. Furthermore, by examining the diurnal cycle of cluster development over Africa and the Indian subcontinent, we observed differences in the local timing of the maximum occurrence at different life cycle stages. Over land there was a strong diurnal peak in the afternoon while over the ocean there was a semi-diurnal peak composed of longer-lived clusters in the early morning hours and shorter-lived clusters in the afternoon. Building on regional specific work, this study provides a long-term, high-resolution, and global survey of object-based cloud characteristics. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20170003683','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20170003683">A Lagrangian Analysis of Cold Cloud Clusters and Their Life Cycles With Satellite Observations</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Esmaili, Rebekah Bradley; Tian, Yudong; Vila, Daniel Alejandro; Kim, Kyu-Myong 2016-01-01 Cloud movement and evolution signify the complex water and energy transport in the atmosphere-ocean-land system. Detecting, clustering, and tracking clouds as semi coherent cluster objects enables study of their evolution which can complement climate model simulations and enhance satellite retrieval algorithms, where there are large gaps between overpasses. Using an area-overlap cluster tracking algorithm, in this study we examine the trajectories, horizontal extent, and brightness temperature variations of millions of individual cloud clusters over their lifespan, from infrared satellite observations at 30-minute, 4-km resolution, for a period of 11 years. We found that the majority of cold clouds were both small and short-lived and that their frequency and location are influenced by El Nino. More importantly, this large sample of individually tracked clouds shows their horizontal size and temperature evolution. Longer lived clusters tended to achieve their temperature and size maturity milestones at different times, while these stages often occurred simultaneously in shorter lived clusters. On average, clusters with this lag also exhibited a greater rainfall contribution than those where minimum temperature and maximum size stages occurred simultaneously. Furthermore, by examining the diurnal cycle of cluster development over Africa and the Indian subcontinent, we observed differences in the local timing of the maximum occurrence at different life cycle stages. Over land there was a strong diurnal peak in the afternoon while over the ocean there was a semi-diurnal peak composed of longer-lived clusters in the early morning hours and shorter-lived clusters in the afternoon. Building on regional specific work, this study provides a long-term, high-resolution, and global survey of object-based cloud characteristics. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23011299','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23011299">Nitrogen cycle and ecosystem services in the Brazilian La Plata Basin: anthropogenic influence and climate change.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Watanabe, M; Ortega, E; Bergier, I; Silva, J S V 2012-08-01 The increasing human demand for food, raw material and energy has radically modified both the landscape and biogeochemical cycles in many river basins in the world. The interference of human activities on the Biosphere is so significant that it has doubled the amount of reactive nitrogen due to industrial fertiliser production (Haber-Bosch), fossil fuel burning and land-use change over the last century. In this context, the Brazilian La Plata Basin contributes to the alteration of the nitrogen cycle in South America because of its huge agricultural and grazing area that meets the demands of its large urban centres - Sao Paulo, for instance - and also external markets abroad. In this paper, we estimate the current inputs and outputs of anthropogenic nitrogen (in kg N.km(-2).yr(-1)) in the basin. In the results, we observe that soybean plays a very important role in the Brazilian La Plata, since it contributes with an annual entrance of about 1.8 TgN due to biological nitrogen fixation. Moreover, our estimate indicates that the export of soybean products accounts for roughly 1.0 TgN which is greater than the annual nitrogen riverine exports from Brazilian Parana, Paraguay and Uruguay rivers together. Complimentarily, we built future scenarios representing changes in the nitrogen cycle profile considering two scenarios of climate change for 2070-2100 (based on IPCC's A2 and B2) that will affect land-use, nitrogen inputs, and loss of such nutrients in the basin. Finally, we discuss how both scenarios will affect human well-being since there is a connection between nitrogen cycle and ecosystem services that affect local and global populations, such as food and fibre production and climate regulation. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25487951','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25487951">Annual burning of a tallgrass prairie inhibits C and N cycling in soil, increasing recalcitrant pyrogenic organic matter storage while reducing N availability.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Soong, Jennifer L; Cotrufo, M Francesca 2015-06-01 Grassland ecosystems store an estimated 30% of the world's total soil C and are frequently disturbed by wildfires or fire management. Aboveground litter decomposition is one of the main processes that form soil organic matter (SOM). However, during a fire biomass is removed or partially combusted and litter inputs to the soil are substituted with inputs of pyrogenic organic matter (py-OM). Py-OM accounts for a more recalcitrant plant input to SOM than fresh litter, and the historical frequency of burning may alter C and N retention of both fresh litter and py-OM inputs to the soil. We compared the fate of these two forms of plant material by incubating (13) C- and (15) N-labeled Andropogon gerardii litter and py-OM at both an annually burned and an infrequently burned tallgrass prairie site for 11 months. We traced litter and py-OM C and N into uncomplexed and organo-mineral SOM fractions and CO2 fluxes and determined how fire history affects the fate of these two forms of aboveground biomass. Evidence from CO2 fluxes and SOM C:N ratios indicates that the litter was microbially transformed during decomposition while, besides an initial labile fraction, py-OM added to SOM largely untransformed by soil microbes. Additionally, at the N-limited annually burned site, litter N was tightly conserved. Together, these results demonstrate how, although py-OM may contribute to C and N sequestration in the soil due to its resistance to microbial degradation, a long history of annual removal of fresh litter and input of py-OM infers N limitation due to the inhibition of microbial decomposition of aboveground plant inputs to the soil. These results provide new insight into how fire may impact plant inputs to the soil, and the effects of py-OM on SOM formation and ecosystem C and N cycling. © 2014 John Wiley & Sons Ltd. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18409654','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18409654">Emissions from photovoltaic life cycles.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Fthenakis, Vasilis M; Kim, Hyung Chul; Alsema, Erik 2008-03-15 Photovoltaic (PV) technologies have shown remarkable progress recently in terms of annual production capacity and life cycle environmental performances, which necessitate timely updates of environmental indicators. Based on PV production data of 2004-2006, this study presents the life-cycle greenhouse gas emissions, criteria pollutant emissions, and heavy metal emissions from four types of major commercial PV systems: multicrystalline silicon, monocrystalline silicon, ribbon silicon, and thin-film cadmium telluride. Life-cycle emissions were determined by employing average electricity mixtures in Europe and the United States during the materials and module production for each PV system. Among the current vintage of PV technologies, thin-film cadmium telluride (CdTe) PV emits the least amount of harmful air emissions as it requires the least amount of energy during the module production. However, the differences in the emissions between different PV technologies are very small in comparison to the emissions from conventional energy technologies that PV could displace. As a part of prospective analysis, the effect of PV breeder was investigated. Overall, all PV technologies generate far less life-cycle air emissions per GWh than conventional fossil-fuel-based electricity generation technologies. At least 89% of air emissions associated with electricity generation could be prevented if electricity from photovoltaics displaces electricity from the grid. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AtmEn..38.1181S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AtmEn..38.1181S">Seasonal cycle of indoor-VOCs: comparison of apartments and cities</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Schlink, U.; Rehwagen, M.; Damm, M.; Richter, M.; Borte, M.; Herbarth, O. On the basis of 2103 measurements of volatile organic compounds (VOCs) in indoor air we study the intensity of a seasonal pattern. The data are representative for the German population and were gathered in different cities (Leipzig, München, Köln), in rooms of different type (children's, living, sleeping rooms, and other rooms), and in households of smokers and non-smokers. In addition to the randomly selected different apartments that were sampled each month, we repeatedly measured in a fixed set of 10 apartments. The analysis comprised concentrations of 30 VOCs belonging to the groups of alkanes, cycloalkanes, aromatics, volatile halogenated hydrocarbons, and terpenes. The annual cycle for total VOC concentrations was observed at every site. Seasonality proved to be the most dominant pattern, but it may be modified by further factors, such as the city, the considered VOC component, and the type of the considered room. Highest concentrations occurred during the winter months and amount to approximately three to four times the summer burden. As seasonality may bias the results of health effect studies we fit a seasonal model to our measurements and develop a procedure for seasonal adjustment, which enables to roughly estimate the annual peak concentration utilizing one monthly observation. The seasonal pattern proved to be a general feature of indoor VOC concentrations and, therefore, this adjustment procedure may be generally applicable. For Leipzig, München, and Köln we present site-specific adjustment factors for indoor concentrations of aromatics, terpenes, and alkanes. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20010095500&hterms=productivity&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dproductivity','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20010095500&hterms=productivity&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dproductivity">Observations of Ocean Primary Productivity Using MODIS</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Esaias, Wayne E.; Abbott, Mark R.; Koblinsky, Chester J. (Technical Monitor) 2001-01-01 Measuring the magnitude and variability of oceanic net primary productivity (NPP) represents a key advancement toward our understanding of the dynamics of marine ecosystems and the role of the ocean in the global carbon cycle. MODIS observations make two new contributions in addition to continuing the bio-optical time series begun with Orbview-2's SeaWiFS sensor. First, MODIS provides weekly estimates of global ocean net primary productivity on weekly and annual time periods, and annual empirical estimates of carbon export production. Second, MODIS provides additional insight into the spatial and temporal variations in photosynthetic efficiency through the direct measurements of solar-stimulated chlorophyll fluorescence. The two different weekly productivity indexes (first developed by Behrenfeld & Falkowski and by Yoder, Ryan and Howard) are used to derive daily productivity as a function of chlorophyll biomass, incident daily surface irradiance, temperature, euphotic depth, and mixed layer depth. Comparisons between these two estimates using both SeaWiFS and MODIS data show significant model differences in spatial distribution after allowance for the different integration depths. Both estimates are strongly dependence on the accuracy of the chlorophyll determination. In addition, an empirical approach is taken on annual scales to estimate global NPP and export production. Estimates of solar stimulated fluorescence efficiency from chlorophyll have been shown to be inversely related to photosynthetic efficiency by Abbott and co-workers. MODIS provides the first global estimates of oceanic chlorophyll fluorescence, providing an important proof of concept. MODIS observations are revealing spatial patterns of fluorescence efficiency which show expected variations with phytoplankton photo-physiological parameters as measured during in-situ surveys. This has opened the way for research into utilizing this information to improve our understanding of oceanic NPP </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5990867','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5990867">Taxonomic and Functional Responses of Soil Microbial Communities to Annual Removal of Aboveground Plant Biomass</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> Guo, Xue; Zhou, Xishu; Hale, Lauren; Yuan, Mengting; Feng, Jiajie; Ning, Daliang; Shi, Zhou; Qin, Yujia; Liu, Feifei; Wu, Liyou; He, Zhili; Van Nostrand, Joy D.; Liu, Xueduan; Luo, Yiqi; Tiedje, James M.; Zhou, Jizhong 2018-01-01 Clipping, removal of aboveground plant biomass, is an important issue in grassland ecology. However, few studies have focused on the effect of clipping on belowground microbial communities. Using integrated metagenomic technologies, we examined the taxonomic and functional responses of soil microbial communities to annual clipping (2010–2014) in a grassland ecosystem of the Great Plains of North America. Our results indicated that clipping significantly (P < 0.05) increased root and microbial respiration rates. Annual temporal variation within the microbial communities was much greater than the significant changes introduced by clipping, but cumulative effects of clipping were still observed in the long-term scale. The abundances of some bacterial and fungal lineages including Actinobacteria and Bacteroidetes were significantly (P < 0.05) changed by clipping. Clipping significantly (P < 0.05) increased the abundances of labile carbon (C) degrading genes. More importantly, the abundances of recalcitrant C degrading genes were consistently and significantly (P < 0.05) increased by clipping in the last 2 years, which could accelerate recalcitrant C degradation and weaken long-term soil carbon stability. Furthermore, genes involved in nutrient-cycling processes including nitrogen cycling and phosphorus utilization were also significantly increased by clipping. The shifts of microbial communities were significantly correlated with soil respiration and plant productivity. Intriguingly, clipping effects on microbial function may be highly regulated by precipitation at the interannual scale. Altogether, our results illustrated the potential of soil microbial communities for increased soil organic matter decomposition under clipping land-use practices. PMID:29904372 </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMGC23K..17H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMGC23K..17H">The future of the North American carbon cycle - projections and associated climate change</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Huntzinger, D. N.; Chatterjee, A.; Cooley, S. R.; Dunne, J. P.; Hoffman, F. M.; Luo, Y.; Moore, D. J.; Ohrel, S. B.; Poulter, B.; Ricciuto, D. M.; Tzortziou, M.; Walker, A. P.; Mayes, M. A. 2016-12-01 Approximately half of anthropogenic emissions from the burning of fossil fuels is taken up annually by carbon sinks on the land and in the oceans. However, there are key uncertainties in how carbon uptake by terrestrial, ocean, and freshwater systems will respond to, and interact with, climate into the future. Here, we outline the current state of understanding on the future carbon budget of these major reservoirs within North America and the globe. We examine the drivers of future carbon cycle changes, including carbon-climate feedbacks, atmospheric composition, nutrient availability, and human activity and management decisions. Progress has been made at identifying vulnerabilities in carbon pools, including high-latitude permafrost, peatlands, freshwater and coastal wetlands, and ecosystems subject to disturbance events, such as insects, fire and drought. However, many of these processes/pools are not well represented in current models, and model intercomparison studies have shown a range in carbon cycle response to factors such as climate and CO2 fertilization. Furthermore, as model complexity increases, understanding the drivers of model spread becomes increasingly more difficult. As a result, uncertainties in future carbon cycle projections are large. It is also uncertain how management decisions and policies will impact future carbon stocks and flows. In order to guide policy, a better understanding of the risk and magnitude of North American carbon cycle changes is needed. This requires that future carbon cycle projections be conditioned on current observations and be reported with sufficient confidence and fully specified uncertainties. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28311508','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28311508">The plurennial life cycles of the European Tettigoniidae (Insecta: Orthoptera) : 1. The effect of temperature on embryonic development and hatching.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Ingrisch, Sigfrid 1986-11-01 The effect of temperature on embryonic development, voltinism, and hatching was studied in the laboratory in eggs of 21 Central and Southeastern European Tettigoniidae species. In most species, the embryo has to arrive at a postkatatrepsis stage prior to the onset of cold to be able to hatch in the following spring. The rate of embryonic development differs: quickly developing species need 4 weeks at 24°C (prior to cold) and almost all eggs hatch after the first cold treatment, slowly developing species would need 8-12 weeks to do the same. In Central Europe, warmth is not enough for the slowly developing species to have an univoltine life cycle, but they could have it in southern Europe. Most species make use of a dormancy sequence to pass successive winters as follows: an initial embryonic dormancy (either quiscence or diapause in embryonic stage 4) and a final diapause in embryonic stage 23/24. Additionally, 3 forms of aestivation or summer dormancy were observed facultatively: an initial diapause in embryonic stage 4 (induced and terminated at 30°C), a median dormancy shortly before or after katatrepsis (at 30°C), and a penultimate diapause in embryonic stage 20 (at 24°C).The life cycles of the European Tettigoniidae species can follow one of 3 types: 1. annual life cycle (no initial embryonic dormancy); 2. annual or biennial depending on whether laid early or late; 3. biennial or many year life cycle (up to 8 years due to a prolonged initial diapause). </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2759978','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2759978">Observation, Assisting, Apprenticeship: Cycles of Visual and Kinesthetic Learning in Dental Education</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> Horst, Jeremy A.; Clark, Matthew D.; Lee, Andrew H. 2009-01-01 Dentists are self-selected for visual and kinesthetic learning preferences. Watching another practitioner perform treatment can be incredibly didactic, both before and after learning the procedure. This missing part of dental education has the capacity to play a tremendous role in dental education for all levels of practitioner. Dental students in their clinical years begin to realize the meaning of dentistry as a practice, a set of skills that are never perfected. Abundant evidence demonstrates that cycling between observation and practice enhances procedural learning and retention, yet this mechanism is vastly underused in dental education. Collaborative treatment paradigms, wherein the able student assists a more experienced practitioner, can create mentorship. Learning potentially esoteric information or subtle nuances of clinical acumen is facilitated by the contextual framework of the clinical environment and is strengthened by emotional attachments through interpersonal interactions. In this article, we explore the evidence surrounding mentorship and clinical observation both before and after students are given the responsibilities of patient care, which together recapitulate clinical apprenticeship. Finally, we present examples of how apprenticeship can be brought back to dental education, including evaluation of a clinical assisting program that we implemented and explanation of a hypothetical faculty-student practice partnership model. PMID:19648563 </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26659186','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26659186">An observational radiative constraint on hydrologic cycle intensification.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> DeAngelis, Anthony M; Qu, Xin; Zelinka, Mark D; Hall, Alex 2015-12-10 Intensification of the hydrologic cycle is a key dimension of climate change, with substantial impacts on human and natural systems. A basic measure of hydrologic cycle intensification is the increase in global-mean precipitation per unit surface warming, which varies by a factor of three in current-generation climate models (about 1-3 per cent per kelvin). Part of the uncertainty may originate from atmosphere-radiation interactions. As the climate warms, increases in shortwave absorption from atmospheric moistening will suppress the precipitation increase. This occurs through a reduction of the latent heating increase required to maintain a balanced atmospheric energy budget. Using an ensemble of climate models, here we show that such models tend to underestimate the sensitivity of solar absorption to variations in atmospheric water vapour, leading to an underestimation in the shortwave absorption increase and an overestimation in the precipitation increase. This sensitivity also varies considerably among models due to differences in radiative transfer parameterizations, explaining a substantial portion of model spread in the precipitation response. Consequently, attaining accurate shortwave absorption responses through improvements to the radiative transfer schemes could reduce the spread in the predicted global precipitation increase per degree warming for the end of the twenty-first century by about 35 per cent, and reduce the estimated ensemble-mean increase in this quantity by almost 40 per cent. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010pcms.confE.106L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010pcms.confE.106L">Hydrological cycle in the Danube basin in present and projected future climate conditions: a models' intercomparison perspective</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Lucarini, V. 2010-09-01 We present an intercomparison and verification analysis of several GCMs and RCMs included in the 4th IPCC assessment report on their representation of the hydrological cycle on the Danube river basin for present and (in the case of the GCMs) projected future climate conditions. The basin-scale properties of the hydrological cycle are computed by spatially integrating the precipitation, evaporation, and runoff fields using the Voronoi-Thiessen tessellation formalism. Large discrepancies exist among RCMs for the monthly climatology as well as for the mean and variability of the annual balances, and only few data sets are consistent with the observed discharge values of the Danube at its Delta. This occurs in spite of common nesting of the RCMs into the same run of the same AGCM, and even if the driving AGCM provides itself an excellent estimate. We find consistently that, for a given model, increases in the resolution do not alter the net water balance, while speeding up the hydrological cycle through the enhancement of both precipitation and evaporation by the same amount. We propose that the atmospheric components of RCMs still face difficulties in representing the water balance even on a relatively large scale. Moreover, since for some models the hydrological balance estimates obtained with the runoff fields do not agree with those obtained via precipitation and evaporation, some deficiencies of the land models are also apparent. In the case of the GCMs, the span of the model- simulated mean annual water balances is of the same order of magnitude of the observed Danube discharge of the Delta; the true value is within the range simulated by the models. Some land components seem to have deficiencies since there are cases of violation of water conservation when annual means are considered. The overall performance and the degree of agreement of the GCMs are, surprisingly, comparable to those of the RCMs. Both RCMs and GCMs greatly outperform the NCEP-NCAR and ERA-40 </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24607594','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24607594">Effects of a cycle training course on children's cycling skills and levels of cycling to school.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Ducheyne, Fabian; De Bourdeaudhuij, Ilse; Lenoir, Matthieu; Cardon, Greet 2014-06-01 The primary aim of the present study was to evaluate the short- and longer-term effects of a cycle training on children's cycling skills. A second aim of the study was to examine the effects of a cycle training, with and without parental involvement, on levels of cycling to school and on parental attitudes towards cycling. Three participating schools were randomly assigned to the "intervention" (25 children), the "intervention plus parent" (34 children) or "control" condition (35 children). A cycle training (four sessions of 45 min) took place only in the intervention schools. Parents in the "intervention plus parent" condition were asked to assist their child in completing weekly homework tasks. Children's cycling skills were assessed, using a practical cycling test. All participating children also received a short parental questionnaire on cycling behavior and parental attitudes towards cycling. Assessments took place at baseline, within 1 week after the last session and at 5-months follow-up. Repeated measure analyses were conducted to evaluate the effects of the cycle training. Children's total cycling skill score increased significantly more from pre to post and from pre to 5-months follow-up in the intervention group than in the control group. On walking with the bicycle (F=1.6), cycling in a straight line (F=2.6), cycling a slalom (F=1.9), cycling over obstacles (F=2.1), cycling on a sloping surface (F=1.7) and dismounting the bicycle (F=2.0), the cycle training had no effect. For all other cycling skills, significant improvements were observed on short- and longer-term. No significant intervention effects were found on children's cycling to school levels (F=1.9) and parental attitudes towards cycling. The cycle training course was effective in improving children's cycling skills and the improvements were maintained 5 months later. However, the cycle training course was not effective in increasing children's cycling to school levels. Copyright © 2014 </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20070009843','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20070009843">An Examination of Sunspot Number Rates of Growth and Decay in Relation to the Sunspot Cycle</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Wilson, Robert M.; Hathaway, David H. 2006-01-01 On the basis of annual sunspot number averages, sunspot number rates of growth and decay are examined relative to both minimum and maximum amplitudes and the time of their occurrences using cycles 12 through present, the most reliably determined sunspot cycles. Indeed, strong correlations are found for predicting the minimum and maximum amplitudes and the time of their occurrences years in advance. As applied to predicting sunspot minimum for cycle 24, the next cycle, its minimum appears likely to occur in 2006, especially if it is a robust cycle similar in nature to cycles 17-23. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.A31B0063M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.A31B0063M">Analyzing the carbon cycle with the local ensemble transform Kalman filter, online transport model and real observation data</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Maki, T.; Sekiyama, T. T.; Shibata, K.; Miyazaki, K.; Miyoshi, T.; Yamada, K.; Yokoo, Y.; Iwasaki, T. 2011-12-01 In the current carbon cycle analysis, inverse modeling plays an important role. However, it requires enormous computational resources when we deal with more flux regions and more observations. The local ensemble transform Kalman filter (LETKF) is an alternative approach to reduce such problems. We constructed a carbon cycle analysis system with the LETKF and MRI (Meteorological Research Institute) online transport model (MJ98-CDTM). In MJ98-CDTM, an off-line transport model (CDTM) is directly coupled with the MRI/JMA GCM (MJ98). We further improved vertical transport processes in MJ98-CDTM from previous study. The LETKF includes enhanced features such as smoother to assimilate future observations, adaptive inflation and bias correction scheme. In this study, we use CO2 observations of surface data (continuous and flask), aircraft data (CONTRAIL) and satellite data (GOSAT), although we plan to assimilate AIRS tropospheric CO2 data. We developed a quality control system. We estimated 3-day-mean CO2 flux at a resolution of T42. Here, only CO2 concentrations and fluxes are analyzed whereas meteorological fields are nudged by the Japanese reanalysis (JCDAS). The horizontal localization length scale and assimilation window are chosen to be 1000 km and 3 days, respectively. The results indicate that the assimilation system works properly, better than free transport model run when we validate with independent CO2 concentration observational data and CO2 analysis data. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMSH42B..07W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMSH42B..07W">Annual Properties of Transverse Waves in the Corona over most of Solar Cycle 24</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Weberg, M. J.; Morton, R. J.; McLaughlin, J. A. 2017-12-01 Waves are an omnipresent feature in heliophysical plasmas. In particular, transverse (or "Alfvénic") waves have been observed at a wide range of spatial and temporal scales within the corona and solar wind. These waves play a key role in transporting energy through the solar atmosphere and are also thought to contribute to the heating and acceleration of the solar wind. Previous studies of low-frequency (< 10 mHz) transverse waves in coronal loops and polar plumes have provided tantalizing glimpses at specific time periods, however few, if any, systematic studies have been performed spanning long time scales. In this study, we combine recent advancements in the automated detection and measurement of low-frequency transverse waves with over 7 years of SDO / AIA data to provide a detailed picture of coronal transverse waves in polar plumes and, for the first time, begin to examine their long-term behaviour. We measure waves at three different heights in each of eight, four-hour periods spanning May 2010 - May 2017. We find that the bulk wave parameters within these 24 regions are largely consistent over most of a solar cycle. However, there is some evidence for smaller-scale variations both with height and over time periods of a few years. We also discuss total energy flux estimations based on the full wave power spectra, which yields a more nuanced picture than previous values based on summary statistics. Overall, this work expands our view of wave processes in the corona and is relevant to both theoretical and modelling considerations of energy transport within the solar atmosphere. Crucially, these initial results suggest that the energy flux provided by the low-frequency transverse waves varies little over the solar cycle, potentially indicating that the waves provide a consistent source of energy to the corona and beyond. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.A53G..04B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.A53G..04B">Monsoons and ITCZ in TRACMIP, the Tropical Rain belts with an Annual cycle and Continent - Model Intercomparison Project</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Biasutti, M.; Voigt, A.; Scheff, J. 2016-12-01 TRACMIP consists of a set of five experiments performed by an ensemble of GCMs and conceived as a link in the hierarchy between the CFMIP/CMIP5 Aqua experiments and the CMIP5 comprehensive simulations. The basic configuration is an aquaplanet AGCM coupled to a slab ocean. By using interactive sea-surface temperatures and seasonally-varying insolation TRACMIP fills the gap between Aquaplanets with prescribed SSTs and fully-coupled realistic CMIP5 simulations. Adding to the basic Aquaplanet configuration a highly-idealized tropical continent allows the investigation of the role of zonal asymmetries in the dynamics of the ITCZ and of the source of the observed differences between land convection and monsoon circulations on one hand, and oceanic convection in the ITCZ and the Warm Pool on the other. Finally, by including both key forcings of the future (greenhouse gases) and of the Holocene (orbital changes in insolation), TRACMIP contributes to the "past to future (P2F)" efforts to connect the climate response to different forcings via a basic understanding of the mechanisms at play. TRACMIP includes the participation of both CMIP5 comprehensive climate models and a simplified model that neglects cloud and water-vapor radiative feedbacks, thus allowing a more direct connection between GCMs results and theoretical studies of tropical rain belt dynamics. We will present preliminary results from the ensemble, aiming to examine the mechanisms controlling tropical precipitation in the context of forced variability. First and foremost, we are interested in the largest forced variation: the annual cycle. We will draw out the similarities and the distinctions between the climatologies of the oceanic and continental rain bands, study the ways in which the two interact with each other, and investigate the extent to which established zonal-mean ITCZ frameworks contain information about regional rainfall characteristics. Second, we will investigate the response to quadrupling the </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20090017763&hterms=pay&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dpay','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20090017763&hterms=pay&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dpay">Predicting the Sunspot Cycle</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Hathaway, David H. 2009-01-01 The 11-year sunspot cycle was discovered by an amateur astronomer in 1844. Visual and photographic observations of sunspots have been made by both amateurs and professionals over the last 400 years. These observations provide key statistical information about the sunspot cycle that do allow for predictions of future activity. However, sunspots and the sunspot cycle are magnetic in nature. For the last 100 years these magnetic measurements have been acquired and used exclusively by professional astronomers to gain new information about the nature of the solar activity cycle. Recently, magnetic dynamo models have evolved to the stage where they can assimilate past data and provide predictions. With the advent of the Internet and open data policies, amateurs now have equal access to the same data used by professionals and equal opportunities to contribute (but, alas, without pay). This talk will describe some of the more useful prediction techniques and reveal what they say about the intensity of the upcoming sunspot cycle. </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active">20</li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active">21</li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014sf2a.conf..523S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014sf2a.conf..523S">Helioseismic inferences of the solar cycles 23 and 24: GOLF and VIRGO observations</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Salabert, D.; García, R. A.; Jiménez, A. 2014-12-01 The Sun-as-a star helioseismic spectrophotometer GOLF and photometer VIRGO instruments onboard the SoHO spacecraft are collecting high-quality, continuous data since April 1996. We analyze here these unique datasets in order to investigate the peculiar and weak on-going solar cycle 24. As this cycle 24 is reaching its maximum, we compare its rising phase with the rising phase of the previous solar cycle 23. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23603066','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23603066">Cardiac hypertrophy and structural and metabolic remodeling related to seasonal dormancy in the first annual cycle in tegu lizards.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> da Silveira, Lilian Cristina; do Nascimento, Lucas Francisco R; Colquhoun, Alison; Abe, Augusto S; de Souza, Silvia Cristina R 2013-07-01 Morpho-functional adjustments in the heart of juvenile tegu lizards (Tupinambis merianae) were analyzed at distinct seasonal periods to investigate how the demands of growth and of energy saving are reconciled during the first annual cycle. The relative ventricular mass (Mv) was 31% and 69% larger in late autumn and winter dormancy, respectively, compared to early autumn. This effect did not persist during unfed arousal, suggesting that protein accumulates in the heart during hypometabolism and is degraded on arousal. Both the hypertrophy and the atrophy were disproportionate in the largest individuals. In contrast, Mv was smaller in lizards that were starved during spring activity compared to fed lizards, this effect being larger in smaller individuals. In late autumn and winter dormancy the spongy myocardium had 8% of the section area covered by lacunary spaces, which expanded after food intake during arousal and reached 29% in spring activity together with higher density of cardiomyocytes. Total and soluble proteins per mass unity were unchanged, and maximum activities of selected enzymes suggest sustained glycolytic and aerobic capacities during hypometabolism. Results indicate that important structural adjustments occur in the heart in anticipation of dormancy, and that the protein balance in the tissue is maintained at winter temperatures ~17°C. Copyright © 2013 Elsevier Inc. All rights reserved. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JASTP.133...79B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JASTP.133...79B">Tropospheric temperature climatology and trends observed over the Middle East</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Basha, Ghouse; Marpu, P. R.; Ouarda, T. B. M. J. 2015-10-01 In this study, we report for the first time, the upper air temperature climatology, and trends over the Middle East, which seem to be significantly affected by the changes associated with hot summer and low precipitation. Long term (1985-2012) radiosonde data from 12 stations are used to derive the mean temperature climatology and vertical trends. The study was performed by analyzing the data at different latitudes. The vertical profiles of air temperature show distinct behavior in terms of vertical and seasonal variability at different latitudes. The seasonal cycle of temperature at the 100 hPa, however, shows an opposite pattern compared to the 200 hPa levels. The temperature at 100 hPa shows a maximum during winter and minimum in summer. Spectral analysis shows that the annual cycle is dominant in comparison with the semiannual cycle. The time-series of temperature data was analyzed using the Bayesian change point analysis and cumulative sum method to investigate the changes in temperature trends. Temperature shows a clear change point during the year 1999 at all stations. Further, Modified Mann-Kendall test was applied to study the vertical trend, and analysis shows statistically significant lower tropospheric warming and cooling in upper troposphere after the year 1999. In general, the magnitude of the trend decreases with altitude in the troposphere. In all the latitude bands in lower troposphere, significant warming is observed, whereas at higher altitudes cooling is noticed based on 28 years temperature observations over the Middle East. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JGRA..123..848L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JGRA..123..848L">The 11 Year Solar Cycle Response of the Equatorial Ionization Anomaly Observed by GPS Radio Occultation</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Li, King-Fai; Lin, Li-Ching; Bui, Xuan-Hien; Liang, Mao-Chang 2018-01-01 We have retrieved the latitudinal and vertical structures of the 11 year solar cycle modulation on ionospheric electron density using 14 years of satellite-based radio occultation measurements utilizing the Global Positioning System. The densities at the crests of the equatorial ionization anomaly (EIA) in the subtropics near 300 km in 2003 and 2014 (high solar activity with solar 10.7 cm flux, <fi>F</fi>10.7 ≈ 140 solar flux unit (sfu)) were 3 times higher than that in 2009 (low solar activity <fi>F</fi>10.7 ≈ 70 sfu). The higher density is attributed to the elevated solar extreme ultraviolet and geomagnetic activity during high solar activity periods. The location of the EIA crests moved 50 km upward and 10° poleward, because of the enhanced E × B force. The EIA in the northern hemisphere was more pronounced than that in the southern hemisphere. This interhemispheric asymmetry is consistent with the effect of enhanced transequatorial neutral wind. The above observations were reproduced qualitatively by the two benchmark runs of the Thermosphere-Ionosphere-Electrodynamics General Circulation Model. In addition, we have studied the impact of the 11 year solar cycle on the 27 day solar cycle response of the ionospheric electron density. Beside the expected modulation on the amplitude of the 27 day solar variation due to the 11 year solar cycle, we find that the altitude of the maximal 27 day solar response is unexpectedly 50 km higher than that of the 11 year solar response. This is the first time that a vertical dependence of the solar responses on different time scales is reported. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.B13E1808F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.B13E1808F">Annual global tree cover estimated by fusing optical and SAR satellite observations</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Feng, M.; Sexton, J. O.; Channan, S.; Townshend, J. R. 2017-12-01 Tree cover defined structurally as the proportional, vertically projected area of vegetation (including leaves, stems, branches, etc.) of woody plants above a given height affects terrestrial energy and water exchanges, photosynthesis and transpiration, net primary production, and carbon and nutrient fluxes. Tree cover provides a measurable attribute upon which forest cover may be defined. Changes in tree cover over time can be used to monitor and retrieve site-specific histories of forest disturbance, succession, and degradation. Measurements of Earth's tree cover have been produced at regional, national, and global extents. However, most representations are static, and those for which multiple time periods have been produced are neither intended nor adequate for consistent, long-term monitoring. Moreover, although a substantial proportion of change has been shown to occur at resolutions below 250 m, existing long-term, Landsat-resolution datasets are either produced as static layers or with annual, five- or ten-year temporal resolution. We have developed an algorithms to retrieve seamless and consistent, sub-hectare resolution estimates of tree-canopy from optical and radar satellite data sources (e.g., Landsat, Sentinel-2, and ALOS-PALSAR). Our approach to estimation enables assimilation of multiple data sources and produces estimates of both cover and its uncertainty at the scale of pixels. It has generated the world's first Landsat-based percent tree cover dataset in 2013. Our previous algorithms are being adapted to produce prototype percent-tree and water-cover layers globally in 2000, 2005, and 2010—as well as annually over North and South America from 2010 to 2015—from passive-optical (Landsat and Sentinel-2) and SAR measurements. Generating a global, annual dataset is beyond the scope of this support; however, North and South America represent all of the world's major biomes and so offer the complete global range of environmental sources of error and </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050060913','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050060913">Estimating Coastal Turbidity using MODIS 250 m Band Observations</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Davies, James E.; Moeller, Christopher C.; Gunshor, Mathew M.; Menzel, W. Paul; Walker, Nan D. 2004-01-01 Terra MODIS 250 m observations are being applied to a Suspended Sediment Concentration (SSC) algorithm that is under development for coastal case 2 waters where reflectance is dominated by sediment entrained in major fluvial outflows. An atmospheric correction based on MODIS observations in the 500 m resolution 1.6 and 2.1 micron bands is used to isolate the remote sensing reflectance in the MODIS 25Om resolution 650 and 865 nanometer bands. SSC estimates from remote sensing reflectance are based on accepted inherent optical properties of sediment types known to be prevalent in the U.S. Gulf of Mexico coastal zone. We present our findings for the Atchafalaya Bay region of the Louisiana Coast, in the form of processed imagery over the annual cycle. We also apply our algorithm to selected sites worldwide with a goal of extending the utility of our approach to the global direct broadcast community. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1052929-simulation-annual-biogeochemical-cycles-nutrient-balance-phytoplankton-bloom-do-puget-sound-using-unstructured-grid-model','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1052929-simulation-annual-biogeochemical-cycles-nutrient-balance-phytoplankton-bloom-do-puget-sound-using-unstructured-grid-model">Simulation of annual biogeochemical cycles of nutrient balance, phytoplankton bloom(s), and DO in Puget Sound using an unstructured grid model</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Khangaonkar, Tarang; Sackmann, Brandon; Long, Wen 2012-08-14 Nutrient pollution from rivers, nonpoint source runoff, and nearly 100 wastewater discharges is a potential threat to the ecological health of Puget Sound with evidence of hypoxia in some basins. However, the relative contributions of loads entering Puget Sound from natural and anthropogenic sources, and the effects of exchange flow from the Pacific Ocean are not well understood. Development of a quantitative model of Puget Sound is thus presented to help improve our understanding of the annual biogeochemical cycles in this system using the unstructured grid Finite-Volume Coastal Ocean Model framework and the Integrated Compartment Model (CE-QUAL-ICM) water quality kinetics.more » Results based on 2006 data show that phytoplankton growth and die-off, succession between two species of algae, nutrient dynamics, and dissolved oxygen in Puget Sound are strongly tied to seasonal variation of temperature, solar radiation, and the annual exchange and flushing induced by upwelled Pacific Ocean waters. Concentrations in the mixed outflow surface layer occupying approximately 5–20 m of the upper water column show strong effects of eutrophication from natural and anthropogenic sources, spring and summer algae blooms, accompanied by depleted nutrients but high dissolved oxygen levels. The bottom layer reflects dissolved oxygen and nutrient concentrations of upwelled Pacific Ocean water modulated by mixing with biologically active surface outflow in the Strait of Juan de Fuca prior to entering Puget Sound over the Admiralty Inlet. The effect of reflux mixing at the Admiralty Inlet sill resulting in lower nutrient and higher dissolved oxygen levels in bottom waters of Puget Sound than the incoming upwelled Pacific Ocean water is reproduced. Finally, by late winter, with the reduction in algal activity, water column constituents of interest, were renewed and the system appeared to reset with cooler temperature, higher nutrient, and higher dissolved oxygen waters from the </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27680704','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27680704">Projected land photosynthesis constrained by changes in the seasonal cycle of atmospheric CO2.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Wenzel, Sabrina; Cox, Peter M; Eyring, Veronika; Friedlingstein, Pierre 2016-10-27 Uncertainties in the response of vegetation to rising atmospheric CO 2 concentrations contribute to the large spread in projections of future climate change. Climate-carbon cycle models generally agree that elevated atmospheric CO 2 concentrations will enhance terrestrial gross primary productivity (GPP). However, the magnitude of this CO 2 fertilization effect varies from a 20 per cent to a 60 per cent increase in GPP for a doubling of atmospheric CO 2 concentrations in model studies. Here we demonstrate emergent constraints on large-scale CO 2 fertilization using observed changes in the amplitude of the atmospheric CO 2 seasonal cycle that are thought to be the result of increasing terrestrial GPP. Our comparison of atmospheric CO 2 measurements from Point Barrow in Alaska and Cape Kumukahi in Hawaii with historical simulations of the latest climate-carbon cycle models demonstrates that the increase in the amplitude of the CO 2 seasonal cycle at both measurement sites is consistent with increasing annual mean GPP, driven in part by climate warming, but with differences in CO 2 fertilization controlling the spread among the model trends. As a result, the relationship between the amplitude of the CO 2 seasonal cycle and the magnitude of CO 2 fertilization of GPP is almost linear across the entire ensemble of models. When combined with the observed trends in the seasonal CO 2 amplitude, these relationships lead to consistent emergent constraints on the CO 2 fertilization of GPP. Overall, we estimate a GPP increase of 37 ± 9 per cent for high-latitude ecosystems and 32 ± 9 per cent for extratropical ecosystems under a doubling of atmospheric CO 2 concentrations on the basis of the Point Barrow and Cape Kumukahi records, respectively. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GBioC..29..223S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GBioC..29..223S">Seasonality of biological and physical controls on surface ocean CO2 from hourly observations at the Southern Ocean Time Series site south of Australia</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Shadwick, E. H.; Trull, T. W.; Tilbrook, B.; Sutton, A. J.; Schulz, E.; Sabine, C. L. 2015-02-01 The Subantarctic Zone (SAZ), which covers the northern half of the Southern Ocean between the Subtropical and Subantarctic Fronts, is important for air-sea CO2 exchange, ventilation of the lower thermocline, and nutrient supply for global ocean productivity. Here we present the first high-resolution autonomous observations of mixed layer CO2 partial pressure (pCO2) and hydrographic properties covering a full annual cycle in the SAZ. The amplitude of the seasonal cycle in pCO2 (˜60 μatm), from near-atmospheric equilibrium in late winter to ˜330 μatm in midsummer, results from opposing physical and biological drivers. Decomposing these contributions demonstrates that the biological control on pCO2 (up to 100 μatm), is 4 times larger than the thermal component and driven by annual net community production of 2.45 ± 1.47 mol C m-2 yr-1. After the summer biological pCO2 depletion, the return to near-atmospheric equilibrium proceeds slowly, driven in part by autumn entrainment into a deepening mixed layer and achieving full equilibration in late winter and early spring as respiration and advection complete the annual cycle. The shutdown of winter convection and associated mixed layer shoaling proceeds intermittently, appearing to frustrate the initiation of production. Horizontal processes, identified from salinity anomalies, are associated with biological pCO2 signatures but with differing impacts in winter (when they reflect far-field variations in dissolved inorganic carbon and/or biomass) and summer (when they suggest promotion of local production by the relief of silicic acid or iron limitation). These results provide clarity on SAZ seasonal carbon cycling and demonstrate that the magnitude of the seasonal pCO2 cycle is twice as large as that in the subarctic high-nutrient, low-chlorophyll waters, which can inform the selection of optimal global models in this region. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19980237265','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19980237265">A Comparison of Wolf's Reconstructed Record of Annual Sunspot Number with Schwabe's Observed Record of 'Clusters of Spots' for the Interval of 1826-1868</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Wilson, Robert M. 1997-01-01 On the basis of a comparison of Wolf s reconstructed record of yearly averages of sunspot number against Schwabe's observations of yearly counts of 'clusters of spots' (i.e., the yearly number of newly appearing sunspot groups) during the interval of 1826-1868, one infers that Wolf probably misplaced and underestimated the maximum amplitude for cycle 7. In particular, Schwabe's data suggest that the maximum amplitude for cycle 7 occurred in 1828 rather than in 1830 and that it measured about 86.3 (+/-13.9; i.e., the 90% confidence level) rather than 70.4. If true, then, the ascent and descent durations for cycle 7 should be 5 years each instead of 7 and 3 years, respectively. Likewise, on the basis of the same comparison, one infers that the maximums for cycles 8 and 9, occurring, respectively, in 1837 and 1848, were of comparable size (approximately 130), although, quite possibly, the one for cycle 8 may have been smaller. Lastly, presuming the continued action of the 'odd-even' effect (i.e., the odd-numbered following cycle of Hale even-odd cycle pairs having a maximum amplitude that is of comparable or larger size than the even-numbered leading cycle) during the earlier pre-modem era of cycles 6-9, one infers that Wolf's estimate for the size of cycle 6 probably is too low. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ThApC.tmp..494A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ThApC.tmp..494A">Trend and change point analyses of annual precipitation in the Souss-Massa Region in Morocco during 1932-2010</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Abahous, H.; Ronchail, J.; Sifeddine, A.; Kenny, L.; Bouchaou, L. 2017-11-01 In the context of an arid area such as Souss Massa Region, the availability of time series analysis of observed local data is vital to better characterize the regional rainfall configuration. In this paper, dataset of monthly precipitation collected from different local meteorological stations during 1932-2010, are quality controlled and analyzed to detect trend and change points. The temporal distribution of outliers shows an annual cycle and a decrease of their number since the 1980s. The results of the standard normal homogeneity test, penalized maximal t test, and Mann-Whitney-Pettit test show that 42% of the series are homogeneous. The analysis of annual precipitation in the region of Souss Massa during 1932-2010 shows wet conditions with a maximum between 1963 and 1965 followed by a decrease since 1973. The latter is identified as a statistically significant regional change point in Western High Atlas and Anti Atlas Mountains highlighting a decline in long-term average precipitation. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29564539','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29564539">Assessing seasonal changes in animal diets with stable-isotope analysis of amino acids: a migratory boreal songbird switches diet over its annual cycle.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Gómez, Camila; Larsen, Thomas; Popp, Brian; Hobson, Keith A; Cadena, Carlos Daniel 2018-05-01 Tools to study seasonal changes in animal diets are needed to address a wide range of ecological questions. This is especially true of migratory animals that experience distinct environments where diets may be substantially different. However, tracking diets of individuals that move vast distances has proven difficult. Compound-specific isotope analysis has emerged as a valuable tool to study diets but has been little used to study dietary changes of migratory animals. Using this technique, we quantify seasonal variation in the annual diet of a migratory songbird (gray-cheeked thrush, Catharus minimus) and test the hypothesis that migrants change their diet in response to the energetic requirements of different periods of the annual cycle. By measuring δ 13 C and δ 15 N values of amino acids from feathers grown on the breeding grounds, blood formed during migration and claw grown on the wintering grounds, we found that migration is associated with greater consumption of fruit, compared to the breeding or wintering periods. This was confirmed by the lower trophic position of blood compared to feather and claw, by a decrease in the δ 15 N value of the source amino acid phenylalanine in blood as a function of days of stopover, and by the positive correlation between δ 15 N and δ 13 C values of phenylalanine in blood, and not in feather or claw. This study illustrates how isotopic analysis of amino acids can contribute to understand food webs, seasonal dietary changes and metabolic routing of nutrients in migratory animals. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1409967-observational-radiative-constraint-hydrologic-cycle-intensification','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1409967-observational-radiative-constraint-hydrologic-cycle-intensification">An observational radiative constraint on hydrologic cycle intensification</a> <a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a> DeAngelis, Anthony M.; Qu, Xin; Zelinka, Mark D.; ... 2015-12-09 We report that intensification of the hydrologic cycle is a key dimension of climate change, with substantial impacts on human and natural systems. A basic measure of hydrologic cycle intensification is the increase in global-mean precipitation per unit surface warming, which varies by a factor of three in current-generation climate models (about 1–3 per cent per kelvin). Part of the uncertainty may originate from atmosphere–radiation interactions. As the climate warms, increases in shortwave absorption from atmospheric moistening will suppress the precipitation increase. This occurs through a reduction of the latent heating increase required to maintain a balanced atmospheric energy budget.more » Using an ensemble of climate models, here we show that such models tend to underestimate the sensitivity of solar absorption to variations in atmospheric water vapour, leading to an underestimation in the shortwave absorption increase and an overestimation in the precipitation increase. This sensitivity also varies considerably among models due to differences in radiative transfer parameterizations, explaining a substantial portion of model spread in the precipitation response. Consequently, attaining accurate shortwave absorption responses through improvements to the radiative transfer schemes could reduce the spread in the predicted global precipitation increase per degree warming for the end of the twenty-first century by about 35 per cent, and reduce the estimated ensemble-mean increase in this quantity by almost 40 per cent.« less </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70029262','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70029262">An empirical model for estimating annual consumption by freshwater fish populations</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Liao, H.; Pierce, C.L.; Larscheid, J.G. 2005-01-01 Population consumption is an important process linking predator populations to their prey resources. Simple tools are needed to enable fisheries managers to estimate population consumption. We assembled 74 individual estimates of annual consumption by freshwater fish populations and their mean annual population size, 41 of which also included estimates of mean annual biomass. The data set included 14 freshwater fish species from 10 different bodies of water. From this data set we developed two simple linear regression models predicting annual population consumption. Log-transformed population size explained 94% of the variation in log-transformed annual population consumption. Log-transformed biomass explained 98% of the variation in log-transformed annual population consumption. We quantified the accuracy of our regressions and three alternative consumption models as the mean percent difference from observed (bioenergetics-derived) estimates in a test data set. Predictions from our population-size regression matched observed consumption estimates poorly (mean percent difference = 222%). Predictions from our biomass regression matched observed consumption reasonably well (mean percent difference = 24%). The biomass regression was superior to an alternative model, similar in complexity, and comparable to two alternative models that were more complex and difficult to apply. Our biomass regression model, log10(consumption) = 0.5442 + 0.9962??log10(biomass), will be a useful tool for fishery managers, enabling them to make reasonably accurate annual population consumption predictions from mean annual biomass estimates. ?? Copyright by the American Fisheries Society 2005. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/EJ1055167.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/EJ1055167.pdf">Adopting Technology: Using Student Qualitative Data and Gartner's Hype Cycle</a> <a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a> Grundmeyer, Trent 2014-01-01 Technology is changing education. School leaders are charged with purchasing and leveraging technology to maximize an ever-changing landscape of teaching and learning. They have many factors to consider as they make decisions about what specific technologies to purchase for their schools. Gartner's Hype Cycle is an annually published report that… </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140002611','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140002611">Meridional Flow Variations in Cycles 23 and 24: Active Latitude Control of Sunspot Cycle Amplitudes</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Hathaway, David H.; Upton, Lisa 2013-01-01 We have measured the meridional motions of magnetic elements observed in the photosphere over sunspot cycles 23 and 24 using magnetograms from SOHO/MDI and SDO/HMI. Our measurements confirm the finding of Komm, Howard, and Harvey (1993) that the poleward meridional flow weakens at cycle maxima. Our high spatial and temporal resolution analyses show that this variation is in the form of a superimposed inflow toward the active latitudes. This inflow is weaker in cycle 24 when compared to the inflow in 23, the stronger cycle. This systematic modulation of the meridional flow should also modulate the amplitude of the following sunspot cycle through its influence on the Sun's polar fields. The observational evidence and the theoretical consequences (similar to those of Cameron and Schussler (2012)) will be described. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20000108881','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20000108881">Examination of Solar Cycle Statistical Model and New Prediction of Solar Cycle 23</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Kim, Myung-Hee Y.; Wilson, John W. 2000-01-01 Sunspot numbers in the current solar cycle 23 were estimated by using a statistical model with the accumulating cycle sunspot data based on the odd-even behavior of historical sunspot cycles from 1 to 22. Since cycle 23 has progressed and the accurate solar minimum occurrence has been defined, the statistical model is validated by comparing the previous prediction with the new measured sunspot number; the improved sunspot projection in short range of future time is made accordingly. The current cycle is expected to have a moderate level of activity. Errors of this model are shown to be self-correcting as cycle observations become available. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22257847-fuel-cycle-cost-uncertainty-from-nuclear-fuel-cycle-comparison','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22257847-fuel-cycle-cost-uncertainty-from-nuclear-fuel-cycle-comparison">Fuel cycle cost uncertainty from nuclear fuel cycle comparison</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Li, J.; McNelis, D.; Yim, M.S. 2013-07-01 This paper examined the uncertainty in fuel cycle cost (FCC) calculation by considering both model and parameter uncertainty. Four different fuel cycle options were compared in the analysis including the once-through cycle (OT), the DUPIC cycle, the MOX cycle and a closed fuel cycle with fast reactors (FR). The model uncertainty was addressed by using three different FCC modeling approaches with and without the time value of money consideration. The relative ratios of FCC in comparison to OT did not change much by using different modeling approaches. This observation was consistent with the results of the sensitivity study for themore » discount rate. Two different sets of data with uncertainty range of unit costs were used to address the parameter uncertainty of the FCC calculation. The sensitivity study showed that the dominating contributor to the total variance of FCC is the uranium price. In general, the FCC of OT was found to be the lowest followed by FR, MOX, and DUPIC. But depending on the uranium price, the FR cycle was found to have lower FCC over OT. The reprocessing cost was also found to have a major impact on FCC.« less </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1198058-variable-stoichiometry-dissolved-organic-matter-cycling-community-earth-system-model','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1198058-variable-stoichiometry-dissolved-organic-matter-cycling-community-earth-system-model">Variable C : N : P stoichiometry of dissolved organic matter cycling in the Community Earth System Model</a> <a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a> Letscher, R. T.; Moore, J. K.; Teng, Y. -C.; ... 2015-01-12 Dissolved organic matter (DOM) plays an important role in the ocean's biological carbon pump by providing an advective/mixing pathway for ~ 20% of export production. DOM is known to have a stoichiometry depleted in nitrogen (N) and phosphorus (P) compared to the particulate organic matter pool, a fact that is often omitted from biogeochemical ocean general circulation models. However the variable C : N : P stoichiometry of DOM becomes important when quantifying carbon export from the upper ocean and linking the nutrient cycles of N and P with that of carbon. Here we utilize recent advances in DOM observationalmore » data coverage and offline tracer-modeling techniques to objectively constrain the variable production and remineralization rates of the DOM C : N : P pools in a simple biogeochemical-ocean model of DOM cycling. The optimized DOM cycling parameters are then incorporated within the Biogeochemical Elemental Cycling (BEC) component of the Community Earth System Model (CESM) and validated against the compilation of marine DOM observations. The optimized BEC simulation including variable DOM C : N : P cycling was found to better reproduce the observed DOM spatial gradients than simulations that used the canonical Redfield ratio. Global annual average export of dissolved organic C, N, and P below 100 m was found to be 2.28 Pg C yr -1 (143 Tmol C yr -1, 16.4 Tmol N yr -1, and 1 Tmol P yr -1, respectively, with an average export C : N : P stoichiometry of 225 : 19 : 1 for the semilabile (degradable) DOM pool. Dissolved organic carbon (DOC) export contributed ~ 25% of the combined organic C export to depths greater than 100 m.« less </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006E%26PSL.242..143L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006E%26PSL.242..143L">Oscillations in land surface hydrological cycle</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Labat, D. 2006-02-01 Hydrological cycle is the perpetual movement of water throughout the various component of the global Earth's system. Focusing on the land surface component of this cycle, the determination of the succession of dry and humid periods is of high importance with respect to water resources management but also with respect to global geochemical cycles. This knowledge requires a specified estimation of recent fluctuations of the land surface cycle at continental and global scales. Our approach leans towards a new estimation of freshwater discharge to oceans from 1875 to 1994 as recently proposed by Labat et al. [Labat, D., Goddéris, Y., Probst, JL, Guyot, JL, 2004. Evidence for global runoff increase related to climate warming. Advances in Water Resources, 631-642]. Wavelet analyses of the annual freshwater discharge time series reveal an intermittent multiannual variability (4- to 8-y, 14- to 16-y and 20- to 25-y fluctuations) and a persistent multidecadal 30- to 40-y variability. Continent by continent, reasonable relationships between land-water cycle oscillations and climate forcing (such as ENSO, NAO or sea surface temperature) are proposed even though if such relationships or correlations remain very complex. The high intermittency of interannual oscillations and the existence of persistent multidecadal fluctuations make prediction difficult for medium-term variability of droughts and high-flows, but lead to a more optimistic diagnostic for long-term fluctuations prediction. </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active">21</li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active">22</li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18..222Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18..222Y">Analysis of the seasonal and inter-annual variations, and long-term trends of ozone in the metropolitan area of Monterrey, Mexico</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Yassmany Hernández Paniagua, Iván; Clemitshaw, Kevin C.; Mendoza, Alberto 2016-04-01 Since 1993, high-precision and high-frequency measurements of ambient O3 have been recorded at 5 sites within the metropolitan area of Monterrey, the third largest city in Mexico. O3was measured by the Integral Environmental Monitoring System of the Nuevo Leon State Government using commercially available, conventional UV photometry instrumentation (precision better than ±1 ppb). The datasets exhibit variations on differing time-scales of minutes to hours, with evidence of seasonal cycles and inter-annual variability. The O3 diurnal cycles vary with length of daylight, which influences its formation and loss via photochemistry. No apparent influence is observed in the amplitudes of O3 diurnal cycles recorded during weekdays with higher emissions from fossil fuel combustion than at weekends, although larger amplitudes occur at sites with polluted air from industrial areas. Seasonal cycles are driven by the variation in solar radiation and changes in emissions of primary precursors, VOCs and NOX. Maximum O3 mixing ratios were recorded in spring, and minimum values in winter, with a secondary trough during summer due to the advection of clean air masses from the Gulf of Mexico. The largest spring maxima are recorded downwind of an industrial area likely due photochemical processing of VOCs and NOx, with the lowest recorded in a highly populated area due to reaction of O3 and NO. At all sites, decreasing seasonal amplitudes were observed during 1993-1998, followed by persistent increases from 1998 to 2014. Wind sector analyses were carried out by splitting the wind direction into 8 categories (45°). At all sites, the highest O3 mixing ratios were recorded from the E and SE sectors, with lowest values recorded in air masses from the W and NW. Wind sector analysis of primary precursors (such as VOCs, CO, NOX) reveal that sources are dominated by emissions from industrial regions in Monterrey and surrounding areas. The largest annual growth rates for the E and SE </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.B33B0481Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.B33B0481Z">Evaluate the seasonal cycle and interannual variability of carbon fluxes and the associated uncertainties using modeled and observed data</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Zeng, F.; Collatz, G. J.; Ivanoff, A. 2013-12-01 We assessed the performance of the Carnegie-Ames-Stanford Approach - Global Fire Emissions Database (CASA-GFED3) terrestrial carbon cycle model in simulating seasonal cycle and interannual variability (IAV) of global and regional carbon fluxes and uncertainties associated with model parameterization. Key model parameters were identified from sensitivity analyses and their uncertainties were propagated through model processes using the Monte Carlo approach to estimate the uncertainties in carbon fluxes and pool sizes. Three independent flux data sets, the global gross primary productivity (GPP) upscaled from eddy covariance flux measurements by Jung et al. (2011), the net ecosystem exchange (NEE) estimated by CarbonTracker, and the eddy covariance flux observations, were used to evaluate modeled fluxes and the uncertainties. Modeled fluxes agree well with both Jung's GPP and CarbonTracker NEE in the amplitude and phase of seasonal cycle, except in the case of GPP in tropical regions where Jung et al. (2011) showed larger fluxes and seasonal amplitude. Modeled GPP IAV is positively correlated (p < 0.1) with Jung's GPP IAV except in the tropics and temperate South America. The correlations between modeled NEE IAV and CarbonTracker NEE IAV are weak at regional to continental scales but stronger when fluxes are aggregated to >40°N latitude. At regional to continental scales flux uncertainties were larger than the IAV in the fluxes for both Jung's GPP and CarbonTracker NEE. Comparisons with eddy covariance flux observations are focused on sites within regions and years of recorded large-scale climate anomalies. We also evaluated modeled biomass using other independent continental biomass estimates and found good agreement. From the comparisons we identify the strengths and weaknesses of the model to capture the seasonal cycle and IAV of carbon fluxes and highlight ways to improve model performance. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.6542R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.6542R">Seasonal and inter-annual variation in ecosystem scale methane emission from a boreal fen</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Rinne, Janne; Li, Xuefei; Raivonen, Maarit; Peltola, Olli; Sallantaus, Tapani; Haapanala, Sami; Smolander, Sampo; Alekseychik, Pavel; Aurela, Mika; Korrensalo, Aino; Mammarella, Ivan; Tuittila, Eeva-Stiina; Vesala, Timo 2016-04-01 Northern wetlands are one of the major sources of atmospheric methane. We have measured ecosystem scale methane emissions from a boreal fen continuously since 2005. The site is an oligotrophic fen in boreal vegetation zone situated in Siikaneva wetland complex in Southern Finland. The mean annual temperature in the area is 3.3°C and total annual precipitation 710 mm. We have conducted the methane emission measurements by the eddy covariance method. Additionally we have measured fluxes of carbon dioxide, water vapor, and sensible heat together with a suite of other environmental parameters. We have analyzed this data alongside with a model run with University of Helsinki methane model. The measured fluxes show generally highest methane emission in late summers coinciding with the highest temperatures in saturated peat zone. During winters the fluxes show small but detectable emission despite the snow and ice cover on the fen. More than 90% of the annual methane emission occurs in snow-free period. The methane emission and peat temperature are connected in exponential manner in seasonal scales, but methane emission does not show the expected behavior with water table. The lack of water table position dependence also contrasts with the spatial variation across microtopography. There is no systematic variation in sub-diurnal time scale. The general seasonal cycle in methane emission is captured well with the methane model. We will show how well the model reproduces the temperature and water table position dependencies observed. The annual methane emission is typically around 10 gC m-2. This is a significant part of the total carbon exchange between the fen and the atmosphere and about twice the estimated carbon loss by leaching from the fen area. The inter-annual variability in the methane emission is modest. The June-September methane emissions from different years, comprising most of the annual emission, correlates positively with peat temperature, but not with </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017BGeo...14.4755K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017BGeo...14.4755K">Reviews and syntheses: guiding the evolution of the observing system for the carbon cycle through quantitative network design</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Kaminski, Thomas; Rayner, Peter Julian 2017-10-01 Various observational data streams have been shown to provide valuable constraints on the state and evolution of the global carbon cycle. These observations have the potential to reduce uncertainties in past, current, and predicted natural and anthropogenic surface fluxes. In particular such observations provide independent information for verification of actions as requested by the Paris Agreement. It is, however, difficult to decide which variables to sample, and how, where, and when to sample them, in order to achieve an optimal use of the observational capabilities. Quantitative network design (QND) assesses the impact of a given set of existing or hypothetical observations in a modelling framework. QND has been used to optimise in situ networks and assess the benefit to be expected from planned space missions. This paper describes recent progress and highlights aspects that are not yet sufficiently addressed. It demonstrates the advantage of an integrated QND system that can simultaneously evaluate a multitude of observational data streams and assess their complementarity and redundancy. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRA..12212274S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRA..12212274S">Flux Enhancements of > 30 keV Electrons at Low Drift Shells L < 1.2 During Last Solar Cycles</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Suvorova, A. V. 2017-12-01 We present results of statistical analysis of enhancements of >30 keV electrons observed by the NOAA/POES satellites during solar cycles 23 and 24 (1998-2016) at low drift shells L < 1.2, so-called forbidden zone. We collected 1,750 days ( 25% of the total time) when fluxes of the forbidden energetic electrons (FEE) exceeded 103 (cm2 s sr)-1. We found 530 days, when FEE fluxes reached high intensity from 104 up to 107 (cm2 s sr)-1. It was found that the FEE enhancements were observed mostly often at the declining phases and solar minimum. More than 85% of the events occurred under fast solar wind (V > 450 km/s), high substorm activity (AL >150 nT), and enhanced interplanetary electric field perturbations (VδB > 1.5 mV/m). The FEE occurrence rate peaks around the local midnight. We have also found a quite unexpected annual variation of the FEE occurrence rate with a pronounced maximum from May to September, a minor peak in December-January, and minima at the equinoxes. The May-September peak, persisting at different solar cycle phases, was assumed to originate from high conductivity in the auroral ionosphere, which is controlled by the dipole tilt angle and provides better conditions for penetration of electric field perturbations into the inner magnetosphere. This allows explanation of the shape and amplitude of annual variation in the FEE occurrence rate from the convolution of the solar wind driver with the penetration conditions. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040095308','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040095308">QBO Generated Inter-annual Variations of the Diurnal Tide in the Mesosphere</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Mayr, Hans G.; Mengel, John G. 2004-01-01 We report results from a study with the Numerical Spectral Model (NSM), which produces in the mesosphere significant inter-annual variations in the diurnal tide. Applying Hines Doppler Spread Parameterization (DPS), small-scale gravity waves (GW) drive the Quasi-biennial Oscillation (QBO) and Semi-annual Oscillation (SAO). With a GW source that peaks at the equator and is taken to be isotropic and independent of season, the NSM generates near the equator a QBO with variable periods around 27 months and zonal wind amplitudes close to 20 m / s at 30 Ism. As reported earlier, the NSM reproduces the observed equinoctial maxima in the diurnal tide at altitudes around 95 km. In the present paper it is shown that the QBO modulates the tide such that the seasonal amplitude maxima can vary from one year to another by as much as 30%. Since the period of the QBO is variable, its phase relative to the seasonal cycle changes. The magnitude of the QBO modulation of the tide thus varies considerably as our long-term model simulation shows. To shed light on the underlying mechanism, the relative importance of the linearized advection terms are discussed that involve the meridional and vertical winds of the diurnal tide. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040171679&hterms=Qbo&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DQbo','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040171679&hterms=Qbo&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DQbo">QBO Generated Inter-annual Variations of the Diurnal Tide in the Mesosphere</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Mayr, Hans G.; Mengel, John G. 2004-01-01 We report results from a study with the Numerical Spectral Model (NSM), which produces in the d i d tide significant inter-annual variations. Applying Hines' Doppler Spread Parameterization (DPS), small-scale gravity waves (GW) drive the Quasi-biennial Oscillation (QBO) and Semi-annual Oscillation (SAO). With a GW source that peaks at the equator and is taken to be isotropic and independent of season, the NSM generates a QBO with variable periods around 27 months and zonal wind amplitudes close to 20 m/s at 30 lan, As reported earlier, the NSM reproduces the observed equinoctial maxima in the diurnal tide at altitudes around 95 km. In the present paper it is shown that the QBO modulates the tide such that the seasonal amplitude maxima can vary from one year to another by as much as 30%. Since the period of the QBO is variable, its phase relative to the seasonal cycle changes. The magnitude of the QBO modulation of the tide thus varies considerably as our long-term model simulation shows. To shed light on the underlying mechanisms, we discuss (a) the relative importance of the linearized advection terms that involve the meridional and vertical winds of the diurnal tide and (b) the effects momentum deposition from GWs filtered by the QBO. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15264543','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15264543">The annual cycle of primary productivity in a tropical estuary: the inner regions of the Golfo de Nicoya, Costa Rica.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Gocke, K; Cortés, J; Murillo, M M 2001-12-01 A one year cycle of primary productivity (PP) was studied using the "light and dark bottle" technique in the Golfo de Nicoya, located at 10 degrees N and 85 degrees W at the Pacific coast of Costa Rica. Samples were always incubated at 0, 1, 2, 3 and 4 m depth for 5 hrs from 8:30 till 13:30. The measurements were performed twice per month, first around high tide and one week later at low tide to account for tidal influences. This routine study was supplemented by special measurements about regional and short-term variations of primary productivity using the 14C-method, which mainly served to account for the shortcomings of the routinely employed incubation technique. The upper Golfo de Nicoya is an extremely productive, phytoplankton dominated estuarine system with an annual gross PP of 1037, a net PP of 610 and a community respiration of 427 g C m(-2) a(-1). Highest monthly PP values occurred during the dry season and at the beginning of the rainy season. Peaks in primary productivity coincided with massive blooms of red tide forming algae. Internal biological dynamics, estuarine circulation and land run-off are the most important nutrient sources. High water turbidity reduces the euphotic layer to 4-5 m depth, making the underwater light regime the rate limiting factor. On an annual basis, 41% of the organic carbon produced in the system is already consumed in the euphotic layer. Considering the entire water column (mean depth at mean tidal water level is around 7.7 m) 79% is consumed in the pelagial. Taking into account the organic material consumed and stored in the sediments the carbon budget of the upper gulf is probably balanced. Since, however, the system receives a considerable amount of organic material from its terrestrial surroundings (especially from the mangrove forests), a surplus of organic carbon is exported from the upper Golfo de Nicoya, which enhances the overall water productivity of the lower gulf and the adjacent area. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018GeoRL..45.2404P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018GeoRL..45.2404P">Evaluating Surface Radiation Fluxes Observed From Satellites in the Southeastern Pacific Ocean</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Pinker, R. T.; Zhang, B.; Weller, R. A.; Chen, W. 2018-03-01 This study is focused on evaluation of current satellite and reanalysis estimates of surface radiative fluxes in a climatically important region. It uses unique observations from the STRATUS Ocean Reference Station buoy in a region of persistent marine stratus clouds 1,500 km off northern Chile during 2000-2012. The study shows that current satellite estimates are in better agreement with buoy observations than model outputs at a daily time scale and that satellite data depict well the observed annual cycle in both shortwave and longwave surface radiative fluxes. Also, buoy and satellite estimates do not show any significant trend over the period of overlap or any interannual variability. This verifies the stability and reliability of the satellite data and should make them useful to examine El Niño-Southern Oscillation variability influences on surface radiative fluxes at the STRATUS site for longer periods for which satellite record is available. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5080864','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5080864">Sea level anomaly on the Patagonian continental shelf: Trends, annual patterns and geostrophic flows</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> Saraceno, M.; Piola, A. R.; Strub, P. T. 2016-01-01 Abstract We study the annual patterns and linear trend of satellite sea level anomaly (SLA) over the southwest South Atlantic continental shelf (SWACS) between 54ºS and 36ºS. Results show that south of 42°S the thermal steric effect explains nearly 100% of the annual amplitude of the SLA, while north of 42°S it explains less than 60%. This difference is due to the halosteric contribution. The annual wind variability plays a minor role over the whole continental shelf. The temporal linear trend in SLA ranges between 1 and 5 mm/yr (95% confidence level). The largest linear trends are found north of 39°S, at 42°S and at 50°S. We propose that in the northern region the large positive linear trends are associated with local changes in the density field caused by advective effects in response to a southward displacement of the South Atlantic High. The causes of the relative large SLA trends in two southern coastal regions are discussed as a function meridional wind stress and river discharge. Finally, we combined the annual cycle of SLA with the mean dynamic topography to estimate the absolute geostrophic velocities. This approach provides the first comprehensive description of the seasonal component of SWACS circulation based on satellite observations. The general circulation of the SWACS is northeastward with stronger/weaker geostrophic currents in austral summer/winter. At all latitudes, geostrophic velocities are larger (up to 20 cm/s) close to the shelf‐break and decrease toward the coast. This spatio‐temporal pattern is more intense north of 45°S. PMID:27840784 </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JAVSO..40..407L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JAVSO..40..407L">Flares, Fears, and Forecasts: Public Misconceptions About the Sunspot Cycle</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Larsen, K. 2012-06-01 Among the disaster scenarios perpetrated by 2012 apocalypse aficionados is the destruction of humankind due to solar flares and coronal mass ejections (CMEs). These scenarios reflect common misconceptions regarding the solar cycle. This paper (based on an annual meeting poster) sheds light on those misconceptions and how the AAVSO Solar Section can address them. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19960045438','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19960045438">On the Importance of Cycle Minimum in Sunspot Cycle Prediction</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Wilson, Robert M.; Hathaway, David H.; Reichmann, Edwin J. 1996-01-01 The characteristics of the minima between sunspot cycles are found to provide important information for predicting the amplitude and timing of the following cycle. For example, the time of the occurrence of sunspot minimum sets the length of the previous cycle, which is correlated by the amplitude-period effect to the amplitude of the next cycle, with cycles of shorter (longer) than average length usually being followed by cycles of larger (smaller) than average size (true for 16 of 21 sunspot cycles). Likewise, the size of the minimum at cycle onset is correlated with the size of the cycle's maximum amplitude, with cycles of larger (smaller) than average size minima usually being associated with larger (smaller) than average size maxima (true for 16 of 22 sunspot cycles). Also, it was found that the size of the previous cycle's minimum and maximum relates to the size of the following cycle's minimum and maximum with an even-odd cycle number dependency. The latter effect suggests that cycle 23 will have a minimum and maximum amplitude probably larger than average in size (in particular, minimum smoothed sunspot number Rm = 12.3 +/- 7.5 and maximum smoothed sunspot number RM = 198.8 +/- 36.5, at the 95-percent level of confidence), further suggesting (by the Waldmeier effect) that it will have a faster than average rise to maximum (fast-rising cycles have ascent durations of about 41 +/- 7 months). Thus, if, as expected, onset for cycle 23 will be December 1996 +/- 3 months, based on smoothed sunspot number, then the length of cycle 22 will be about 123 +/- 3 months, inferring that it is a short-period cycle and that cycle 23 maximum amplitude probably will be larger than average in size (from the amplitude-period effect), having an RM of about 133 +/- 39 (based on the usual +/- 30 percent spread that has been seen between observed and predicted values), with maximum amplitude occurrence likely sometime between July 1999 and October 2000. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28797249','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28797249">Wind conditions on migration influence the annual survival of a neotropical migrant, the western yellow-breasted chat (Icteria virens auricollis).</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Huang, Andrew C; Bishop, Christine A; McKibbin, René; Drake, Anna; Green, David J 2017-08-10 Long-distance migratory birds in North America have undergone precipitous declines over the past half-century. Although the trend is clear, for many migrating species underpinning the exact causes poses a challenge to conservation due to the numerous stressors that they encounter. Climate conditions during all phases of their annual cycle can have important consequences for their survival. Here, using 15 years of capture-recapture dataset, we determined the effects of various climate factors during the breeding, wintering, and migrating stages on the annual survival of a western yellow-breasted chat (Icteria virens auricollis) population breeding in southwestern Canada. El Niño effects over the entire annual cycle had little influence on the annual apparent survival of yellow-breasted chats. However, we found evidence that wind conditions during migration, specifically average westerly wind speed or the frequency of storm events, had significant adverse effects on adult annual apparent survival. In comparison, precipitation levels on wintering ground had little to no influence on adult annual apparent survival, whereas growing degree days on the breeding ground had moderate but positive effects. In the face of climate change and its predicted impacts on climate processes, understanding the influence of weather conditions on the survival of migrating birds can allow appropriate conservation strategies to be adopted for chats and other declining neotropical migrants. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16778887','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16778887">The importance of the diurnal and annual cycle of air traffic for contrail radiative forcing.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Stuber, Nicola; Forster, Piers; Rädel, Gaby; Shine, Keith 2006-06-15 Air traffic condensation trails, or contrails, are believed to have a net atmospheric warming effect, although one that is currently small compared to that induced by other sources of human emissions. However, the comparably large growth rate of air traffic requires an improved understanding of the resulting impact of aircraft radiative forcing on climate. Contrails have an effect on the Earth's energy balance similar to that of high thin ice clouds. Their trapping of outgoing longwave radiation emitted by the Earth and atmosphere (positive radiative forcing) is partly compensated by their reflection of incoming solar radiation (negative radiative forcing). On average, the longwave effect dominates and the net contrail radiative forcing is believed to be positive. Over daily and annual timescales, varying levels of air traffic, meteorological conditions, and solar insolation influence the net forcing effect of contrails. Here we determine the factors most important for contrail climate forcing using a sophisticated radiative transfer model for a site in southeast England, located in the entrance to the North Atlantic flight corridor. We find that night-time flights during winter (December to February) are responsible for most of the contrail radiative forcing. Night flights account for only 25 per cent of daily air traffic, but contribute 60 to 80 per cent of the contrail forcing. Further, winter flights account for only 22 per cent of annual air traffic, but contribute half of the annual mean forcing. These results suggest that flight rescheduling could help to minimize the climate impact of aviation. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20060026207','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20060026207">Observational Evidence of Impacts of Aerosols on Seasonal-to-Interannual Variability of the Asian Monsoon</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Lau, K.-M.; Kim, K.-M.; Hsu, N. C. 2006-01-01 Observational evidences are presented showing that the Indian subcontinent and surrounding regions are subject to heavy loading of absorbing aerosols (dust and black carbon), with strong seasonality closely linked to the monsoon annual rainfall cycle. Increased loading of absorbing aerosols over the Indo-Gangetic Plain in April-May is associated with a) increased heating of the upper troposphere over the Tibetan Plateau, b) an advance of the monsoon rainy season, and c) subsequent enhancement of monsoon rainfall over the South Asia subcontinent, and reduction over East Asia. Also presented are radiative transfer calculations showing how differential solar absorption by aerosols over bright surface (desert or snow cover land) compared to dark surface (vegetated land and ocean), may be instrumental in triggering an aerosol-monsoon large-scale circulation and water cycle feedback, consistent with the elevated heat pump hypothesis (Lau et al. 2006). </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRD..12210246R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRD..12210246R">The East Asian Atmospheric Water Cycle and Monsoon Circulation in the Met Office Unified Model</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Rodríguez, José M.; Milton, Sean F.; Marzin, Charline 2017-10-01 In this study the low-level monsoon circulation and observed sources of moisture responsible for the maintenance and seasonal evolution of the East Asian monsoon are examined, studying the detailed water budget components. These observational estimates are contrasted with the Met Office Unified Model (MetUM) climate simulation performance in capturing the circulation and water cycle at a variety of model horizontal resolutions and in fully coupled ocean-atmosphere simulations. We study the role of large-scale circulation in determining the hydrological cycle by analyzing key systematic errors in the model simulations. MetUM climate simulations exhibit robust circulation errors, including a weakening of the summer west Pacific Subtropical High, which leads to an underestimation of the southwesterly monsoon flow over the region. Precipitation and implied diabatic heating biases in the South Asian monsoon and Maritime Continent region are shown, via nudging sensitivity experiments, to have an impact on the East Asian monsoon circulation. By inference, the improvement of these tropical biases with increased model horizontal resolution is hypothesized to be a factor in improvements seen over East Asia with increased resolution. Results from the annual cycle of the hydrological budget components in five domains show a good agreement between MetUM simulations and ERA-Interim reanalysis in northern and Tibetan domains. In simulations, the contribution from moisture convergence is larger than in reanalysis, and they display less precipitation recycling over land. The errors are closely linked to monsoon circulation biases. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010JGRD..11520308I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010JGRD..11520308I">Stratospheric influence on the seasonal cycle of nitrous oxide in the troposphere as deduced from aircraft observations and model simulations</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Ishijima, Kentaro; Patra, Prabir K.; Takigawa, Masayuki; Machida, Toshinobu; Matsueda, Hidekazu; Sawa, Yosuke; Steele, L. Paul; Krummel, Paul B.; Langenfelds, Ray L.; Aoki, Shuji; Nakazawa, Takakiyo 2010-10-01 The atmospheric N2O variations between the Earth's surface and the lower stratosphere, simulated by an atmospheric general circulation model-based chemistry transport model (ACTM), are compared with aircraft and satellite observations. We validate the newly developed ACTM simulations of N2O for loss rate and transport in the stratosphere using satellite observations from the Aura Microwave Limb Sounder (Aura-MLS), with optimized surface fluxes for reproducing N2O trends observed at the surface stations. Observations in the upper troposphere/lower stratosphere (UT/LS) obtained by the Japan AirLines commercial flights commuting between Narita (36°N), Japan, and Sydney (34°S), Australia, have been used to study the role of stratosphere-troposphere exchange (STE) on N2O variability near the tropopause. Low N2O concentration events in the UT region are shown to be captured statistically significantly by the ACTM simulation. This is attributed to successful reproduction of stratospheric air intrusion events and N2O vertical/horizontal gradients in the lower stratosphere. The meteorological fields and N2O concentrations reproduced in the ACTM are used to illustrate the mechanisms of STE and subsequent downward propagation of N2O-depleted stratospheric air in the troposphere. Aircraft observations of N2O vertical profile over Surgut (West Siberia, Russia; 61°N), Sendai-Fukuoka (Japan; 34°N-38°N), and Cape Grim (Tasmania, Australia; 41°S) have been used to estimate the relative contribution of surface fluxes, transport seasonality in the troposphere, and STE to N2O seasonal cycles at different altitude levels. Stratospheric N2O tracers are incorporated in the ACTM for quantitative estimation of the stratospheric influence on tropospheric N2O. The results suggest strong latitude dependency of the stratospheric contribution to the tropospheric N2O seasonal cycle. The periods of seasonal minimum in the upper troposphere, which are spring over Japan and summer over Surgut </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23713246','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23713246">[A wavelet analysis on the onset cycle of scarlet fever in Beijing and its relationship with theory of five evolutive phases and six climatic factors].</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Fu, Bang-ze; Tang, Qiao-ling; Huang, Ling; He, Juan 2013-03-01 To explore the onset cycle of scarlet fever in Beijing and its association with theory of five evolutive phases and six climatic factors (FEPSCF). Based on the monthly scarlet fever data from 1970 to 2004, Complex Morlet wavelet was adopted to analyze the annual incidence and the incidence of six climatic factors in the past 35 years. Its association with the cycles of FEP-SCF was explored. The features of heavenly stems and earthly branches in the year that the wave peak corresponded and their correlations with doctrine of FEPSCF were analyzed. The annual incidence of scarlet fever and the incidence of FEPSCF had two main cycles, i.e., 5 years and 28 years. The 5-year primary cycle was consistent with 5-year cycle of FEPSCF theory. The high incidence year of 5-year primary cycle was Jinyun. The cycle of five evolutive phases was consistent with the onset cycle of scarlet fever. The quasi-periodic phenomenon and multi-cycle superimposed phenomenon of FEPSCF theory existed in the incidence of scarlet fever. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRD..12213387Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRD..12213387Z">The Diurnal Cycle of Clouds and Precipitation at the ARM SGP Site: An Atmospheric State-Based Analysis and Error Decomposition of a Multiscale Modeling Framework Simulation</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Zhao, Wei; Marchand, Roger; Fu, Qiang 2017-12-01 Long-term reflectivity data collected by a millimeter cloud radar at the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site are used to examine the diurnal cycle of clouds and precipitation and are compared with the diurnal cycle simulated by a Multiscale Modeling Framework (MMF) climate model. The study uses a set of atmospheric states that were created specifically for the SGP and for the purpose of investigating under what synoptic conditions models compare well with observations on a statistical basis (rather than using case studies or seasonal or longer time scale averaging). Differences in the annual mean diurnal cycle between observations and the MMF are decomposed into differences due to the relative frequency of states, the daily mean vertical profile of hydrometeor occurrence, and the (normalized) diurnal variation of hydrometeors in each state. Here the hydrometeors are classified as cloud or precipitation based solely on the reflectivity observed by a millimeter radar or generated by a radar simulator. The results show that the MMF does not capture the diurnal variation of low clouds well in any of the states but does a reasonable job capturing the diurnal variations of high clouds and precipitation in some states. In particular, the diurnal variations in states that occur during summer are reasonably captured by the MMF, while the diurnal variations in states that occur during the transition seasons (spring and fall) are not well captured. Overall, the errors in the annual composite are due primarily to errors in the daily mean of hydrometeor occurrence (rather than diurnal variations), but errors in the state frequency (that is, the distribution of weather states in the model) also play a significant role. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMGC41A1006Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMGC41A1006Z">Tropical rainforests dominate multi-decadal variability of the global carbon cycle</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Zhang, X.; Wang, Y. P.; Peng, S.; Rayner, P. J.; Silver, J.; Ciais, P.; Piao, S.; Zhu, Z.; Lu, X.; Zheng, X. 2017-12-01 Recent studies find that inter-annual variability of global atmosphere-to-land CO2 uptake (NBP) is dominated by semi-arid ecosystems. However, the NBP variations at decadal to multi-decadal timescales are still not known. By developing a basic theory for the role of net primary production (NPP) and heterotrophic respiration (Rh) on NBP and applying it to 100-year simulations of terrestrial ecosystem models forced by observational climate, we find that tropical rainforests dominate the multi-decadal variability of global NBP (48%) rather than the semi-arid lands (35%). The NBP variation at inter-annual timescales is almost 90% contributed by NPP, but across longer timescales is progressively controlled by Rh that constitutes the response from the NPP-derived soil carbon input (40%) and the response of soil carbon turnover rates to climate variability (60%). The NBP variations of tropical rainforests is modulated by the ENSO and the PDO through their significant influences on temperature and precipitation at timescales of 2.5-7 and 25-50 years, respectively. This study highlights the importance of tropical rainforests on the multi-decadal variability of global carbon cycle, suggesting that we need to carefully differentiate the effect of NBP long-term fluctuations associated with ocean-related climate modes on the long-term trend in land sink. </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active">22</li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active">23</li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AAS...204.3603B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AAS...204.3603B">Stellar magnetic cycles</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Baliunas, S. L. 2004-05-01 Is hope for understanding the solar magnetic cycle to be found in stars? Observations of stars with significant sub-surface convective zones -- masses smaller than about 1.5 solar masses on the lower main sequence and many types of cool, post-main-sequence stars -- indicate the presence of surface and atmospheric inhomogeneities analogous to solar magnetic features, making stellar magnetic activity a cosmically widespread phenomenon. Observations have been made primarily in visible wavelengths, and important information has also been derived from the ultraviolet and x-ray spectrum regions. Interannual to interdecadal variability of spectrum indicators of stellar magnetic features is common, and in some cases similar in appearance to the 11-year sunspot cycle. Successful models of the physical processes responsible for stellar magnetic cycles, typically cast as a magnetohydrodynamic dynamo, require advances in understanding not only convection but also the magnetic field's interaction with it. The observed facts that underpin the hope for models will be summarized. Properties of stellar magnetic cycles will be compared and contrasted with those of the sun, including inferences from paleo-environmental reservoirs that contain information on solar century- to millennial-scale magnetic variability. Partial support of this research came from NASA NAG5-7635, NRC COBASE, CRDF 322, MIT-MSG 5710001241, JPL 1236821, AF 49620-02-1-0194, Richard Lounsberry Foundation, Langley-Abbot, Rollins, Scholarly Studies and James Arthur Funds (Smithsonian Institution) and several generous individuals. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998AnGeo..16..974S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998AnGeo..16..974S">Annual and seasonal variations in the low-latitude topside ionosphere</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Su, Y. Z.; Bailey, G. J.; Oyama, K.-I. 1998-08-01 Annual and seasonal variations in the low-latitude topside ionosphere are investigated using observations made by the Hinotori satellite and the Sheffield University Plasmasphere Ionosphere Model (SUPIM). The observed electron densities at 600 km altitude show a strong annual anomaly at all longitudes. The average electron densities of conjugate latitudes within the latitude range +/-25° are higher at the December solstice than at the June solstice by about 100 during daytime and 30 during night-time. Model calculations show that the annual variations in the neutral gas densities play important roles. The model values obtained from calculations with inputs for the neutral densities obtained from MSIS86 reproduce the general behaviour of the observed annual anomaly. However, the differences in the modelled electron densities at the two solstices are only about 30 of that seen in the observed values. The model calculations suggest that while the differences between the solstice values of neutral wind, resulting from the coupling of the neutral gas and plasma, may also make a significant contribution to the daytime annual anomaly, the E×B drift velocity may slightly weaken the annual anomaly during daytime and strengthen the anomaly during the post-sunset period. It is suggested that energy sources, other than those arising from the 6 difference in the solar EUV fluxes at the two solstices due to the change in the Sun-Earth distance, may contribute to the annual anomaly. Observations show strong seasonal variations at the solstices, with the electron density at 600 km altitude being higher in the summer hemisphere than in the winter hemisphere, contrary to the behaviour in NmF2. Model calculations confirm that the seasonal behaviour results from effects caused by transequatorial component of the neutral wind in the direction summer hemisphere to winter hemisphere. Acknowledgements. We thank all the members of the Exos-D project team, especially K. Tsuruda and H. Oya </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/911579','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/911579">Financing Strategies For A Nuclear Fuel Cycle Facility</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> David Shropshire; Sharon Chandler 2006-07-01 To help meet the nation’s energy needs, recycling of partially used nuclear fuel is required to close the nuclear fuel cycle, but implementing this step will require considerable investment. This report evaluates financing scenarios for integrating recycling facilities into the nuclear fuel cycle. A range of options from fully government owned to fully private owned were evaluated using DPL (Decision Programming Language 6.0), which can systematically optimize outcomes based on user-defined criteria (e.g., lowest lifecycle cost, lowest unit cost). This evaluation concludes that the lowest unit costs and lifetime costs are found for a fully government-owned financing strategy, due tomore » government forgiveness of debt as sunk costs. However, this does not mean that the facilities should necessarily be constructed and operated by the government. The costs for hybrid combinations of public and private (commercial) financed options can compete under some circumstances with the costs of the government option. This analysis shows that commercial operations have potential to be economical, but there is presently no incentive for private industry involvement. The Nuclear Waste Policy Act (NWPA) currently establishes government ownership of partially used commercial nuclear fuel. In addition, the recently announced Global Nuclear Energy Partnership (GNEP) suggests fuels from several countries will be recycled in the United States as part of an international governmental agreement; this also assumes government ownership. Overwhelmingly, uncertainty in annual facility capacity led to the greatest variations in unit costs necessary for recovery of operating and capital expenditures; the ability to determine annual capacity will be a driving factor in setting unit costs. For private ventures, the costs of capital, especially equity interest rates, dominate the balance sheet; and the annual operating costs, forgiveness of debt, and overnight costs dominate the costs </li> <li> <a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED573083.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED573083.pdf">A Growth Model for the Academic Program Life Cycle (APLC): A Theoretical and Empirical Analysis. IR Applications, Volume 33</a> <a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a> Acquah, Edward H. K. 2012-01-01 The academic program life cycle (APLC) concept states each program's life flows through several stages: introduction, growth, maturity, and decline. A mixed-influence diffusion growth model is fitted to annual enrollment data on academic programs to analyze the factors determining progress of academic programs through their life cycles. The… </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010BGeo....7.2061I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010BGeo....7.2061I">Multi-model analysis of terrestrial carbon cycles in Japan: limitations and implications of model calibration using eddy flux observations</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Ichii, K.; Suzuki, T.; Kato, T.; Ito, A.; Hajima, T.; Ueyama, M.; Sasai, T.; Hirata, R.; Saigusa, N.; Ohtani, Y.; Takagi, K. 2010-07-01 Terrestrial biosphere models show large differences when simulating carbon and water cycles, and reducing these differences is a priority for developing more accurate estimates of the condition of terrestrial ecosystems and future climate change. To reduce uncertainties and improve the understanding of their carbon budgets, we investigated the utility of the eddy flux datasets to improve model simulations and reduce variabilities among multi-model outputs of terrestrial biosphere models in Japan. Using 9 terrestrial biosphere models (Support Vector Machine - based regressions, TOPS, CASA, VISIT, Biome-BGC, DAYCENT, SEIB, LPJ, and TRIFFID), we conducted two simulations: (1) point simulations at four eddy flux sites in Japan and (2) spatial simulations for Japan with a default model (based on original settings) and a modified model (based on model parameter tuning using eddy flux data). Generally, models using default model settings showed large deviations in model outputs from observation with large model-by-model variability. However, after we calibrated the model parameters using eddy flux data (GPP, RE and NEP), most models successfully simulated seasonal variations in the carbon cycle, with less variability among models. We also found that interannual variations in the carbon cycle are mostly consistent among models and observations. Spatial analysis also showed a large reduction in the variability among model outputs. This study demonstrated that careful validation and calibration of models with available eddy flux data reduced model-by-model differences. Yet, site history, analysis of model structure changes, and more objective procedure of model calibration should be included in the further analysis. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.G21C..07B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.G21C..07B">Continental-scale water fluxes from continuous GPS observations of Earth surface loading</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Borsa, A. A.; Agnew, D. C.; Cayan, D. R. 2015-12-01 After more than a decade of observing annual oscillations of Earth's surface from seasonal snow and water loading, continuous GPS is now being used to model time-varying terrestrial water fluxes on the local and regional scale. Although the largest signal is typically due to the seasonal hydrological cycle, GPS can also measure subtle surface deformation caused by sustained wet and dry periods, and to estimate the spatial distribution of the underlying terrestrial water storage changes. The next frontier is expanding this analysis to the continental scale and paving the way for incorporating GPS models into the National Climate Assessment and into the observational infrastructure for national water resource management. This will require reconciling GPS observations with predictions from hydrological models and with remote sensing observations from a suite of satellite instruments (e.g. GRACE, SMAP, SWOT). The elastic Earth response which transforms surface loads into vertical and horizontal displacements is also responsible for the contamination of loading observations by tectonic and anthropogenic transients, and we discuss these and other challenges to this new application of GPS. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19990018406','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19990018406">Evidence for Solar-Cycle Forcing and Secular Variation in the Armagh Observatory Temperature Record</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Wilson, Robert M. 1998-01-01 A prominent feature of previous long-term temperature studies has been the appearance of warming since the 1880s, this often being taken as evidence for anthropogenic-induced global warming. In this investigation, the long-term, annual, mean temperature record (1844-1992) of the Armagh Observatory (Armagh, North Ireland), a set of temperature data based on maximum and minimum thermometers that predates the 1880s and correlates well with northern hemispheric and global standards, is examined for evidence of systematic variation, in particular, as related to solar-cycle forcing and secular variation. Indeed, both appear to be embedded within the Armagh data. Removal of these effects, each contributing about 8% to the overall reduction in variance, yields residuals that are randomly distributed. Application of the 10-year moving average to the residuals, furthermore, strongly suggests that the behavior of the residuals is episodic, inferring that (for extended periods of time) temperatures at Armagh sometimes were warmer or cooler (than expected), while at other times they were stable. Comparison of cyclic averages of annual mean temperatures against the lengths of the associated Hale cycles (i.e., the length of two, sequentially numbered, even-odd sunspot cycle pairs) strongly suggests that the temperatures correlate inversely (r = -0.886 at less than 2% level of significance) against the length of the associated Hale cycle. Because sunspot cycle 22 ended in 1996, the present Hale cycle probably will be shorter than average, implying that temperatures at Armagh over this Hale cycle will be warmer (about 9.31 q 0.23 C at the 90% confidence level) than average (= 9.00 C). </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70191922','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70191922">CO2 cycle</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Titus, Timothy N.; Byrne, Shane; Colaprete, Anthony; Forget, Francois; Michaels, Timothy I.; Prettyman, Thomas H. 2017-01-01 This chapter discusses the use of models, observations, and laboratory experiments to understand the cycling of CO2 between the atmosphere and seasonal Martian polar caps. This cycle is primarily controlled by the polar heat budget, and thus the emphasis here is on its components, including solar and infrared radiation, the effect of clouds (water- and CO2-ice), atmospheric transport, and subsurface heat conduction. There is a discussion about cap properties including growth and regression rates, albedos and emissivities, grain sizes and dust and/or water-ice contamination, and curious features like cold gas jets and araneiform (spider-shaped) terrain. The nature of the residual south polar cap is discussed as well as its long-term stability and ability to buffer atmospheric pressures. There is also a discussion of the consequences of the CO2 cycle as revealed by the non-condensable gas enrichment observed by Odyssey and modeled by various groups. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018BGeo...15.2851P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018BGeo...15.2851P">The seasonal cycle of pCO2 and CO2 fluxes in the Southern Ocean: diagnosing anomalies in CMIP5 Earth system models</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Precious Mongwe, N.; Vichi, Marcello; Monteiro, Pedro M. S. 2018-05-01 The Southern Ocean forms an important component of the Earth system as a major sink of CO2 and heat. Recent studies based on the Coupled Model Intercomparison Project version 5 (CMIP5) Earth system models (ESMs) show that CMIP5 models disagree on the phasing of the seasonal cycle of the CO2 flux (FCO2) and compare poorly with available observation products for the Southern Ocean. Because the seasonal cycle is the dominant mode of CO2 variability in the Southern Ocean, its simulation is a rigorous test for models and their long-term projections. Here we examine the competing roles of temperature and dissolved inorganic carbon (DIC) as drivers of the seasonal cycle of pCO2 in the Southern Ocean to explain the mechanistic basis for the seasonal biases in CMIP5 models. We find that despite significant differences in the spatial characteristics of the mean annual fluxes, the intra-model homogeneity in the seasonal cycle of FCO2 is greater than observational products. FCO2 biases in CMIP5 models can be grouped into two main categories, i.e., group-SST and group-DIC. Group-SST models show an exaggeration of the seasonal rates of change of sea surface temperature (SST) in autumn and spring during the cooling and warming peaks. These higher-than-observed rates of change of SST tip the control of the seasonal cycle of pCO2 and FCO2 towards SST and result in a divergence between the observed and modeled seasonal cycles, particularly in the Sub-Antarctic Zone. While almost all analyzed models (9 out of 10) show these SST-driven biases, 3 out of 10 (namely NorESM1-ME, HadGEM-ES and MPI-ESM, collectively the group-DIC models) compensate for the solubility bias because of their overly exaggerated primary production, such that biologically driven DIC changes mainly regulate the seasonal cycle of FCO2. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AIPC.1850f0002G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AIPC.1850f0002G">Advanced power cycles and configurations for solar towers: Modeling and optimization of the decoupled solar combined cycle concept</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> García-Barberena, Javier; Olcoz, Asier; Sorbet, Fco. Javier 2017-06-01 CSP technologies are essential to allow large shares of renewables into the grid due to their unique ability to cope with the large variability of the energy resource by means of technically and economically feasible thermal energy storage (TES) systems. However, there is still the need and sought to achieve technological breakthroughs towards cost reductions and increased efficiencies. For this, research on advanced power cycles, like the Decoupled Solar Combined Cycle (DSCC) is, are regarded as a key objective. The DSCC concept is, basically, a Combined Brayton-Rankine cycle in which the bottoming cycle is decoupled from the operation of the topping cycle by means of an intermediate storage system. According to this concept, one or several solar towers driving a solar air receiver and a Gas Turbine (Brayton cycle) feed through their exhaust gasses a single storage system and bottoming cycle. This general concept benefits from a large flexibility in its design. On the one hand, different possible schemes related to number and configuration of solar towers, storage systems media and configuration, bottoming cycles, etc. are possible. On the other, within a specific scheme a large number of design parameters can be optimized, including the solar field size, the operating temperatures and pressures of the receiver, the power of the Brayton and Rankine cycles, the storage capacity and others. Heretofore, DSCC plants have been analyzed by means of simple steady-state models with pre-stablished operating parameters in the power cycles. In this work, a detailed transient simulation model for DSCC plants has been developed and is used to analyze different DSCC plant schemes. For each of the analyzed plant schemes, a sensitivity analysis and selection of the main design parameters is carried out. Results show that an increase in annual solar to electric efficiency of 30% (from 12.91 to 16.78) can be achieved by using two bottoming Rankine cycles at two different </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28474999','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28474999">Cell division cycle 45 promotes papillary thyroid cancer progression via regulating cell cycle.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Sun, Jing; Shi, Run; Zhao, Sha; Li, Xiaona; Lu, Shan; Bu, Hemei; Ma, Xianghua 2017-05-01 Cell division cycle 45 was reported to be overexpressed in some cancer-derived cell lines and was predicted to be a candidate oncogene in cervical cancer. However, the clinical and biological significance of cell division cycle 45 in papillary thyroid cancer has never been investigated. We determined the expression level and clinical significance of cell division cycle 45 using The Cancer Genome Atlas, quantitative real-time polymerase chain reaction, and immunohistochemistry. A great upregulation of cell division cycle 45 was observed in papillary thyroid cancer tissues compared with adjacent normal tissues. Furthermore, overexpression of cell division cycle 45 positively correlates with more advanced clinical characteristics. Silence of cell division cycle 45 suppressed proliferation of papillary thyroid cancer cells via G1-phase arrest and inducing apoptosis. The oncogenic activity of cell division cycle 45 was also confirmed in vivo. In conclusion, cell division cycle 45 may serve as a novel biomarker and a potential therapeutic target for papillary thyroid cancer. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/6392855','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/6392855">Cell cycle phases in the unequal mother/daughter cell cycles of Saccharomyces cerevisiae.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Brewer, B J; Chlebowicz-Sledziewska, E; Fangman, W L 1984-11-01 During cell division in the yeast Saccharomyces cerevisiae mother cells produce buds (daughter cells) which are smaller and have longer cell cycles. We performed experiments to compare the lengths of cell cycle phases in mothers and daughters. As anticipated from earlier indirect observations, the longer cell cycle time of daughter cells is accounted for by a longer G1 interval. The S-phase and the G2-phase are of the same duration in mother and daughter cells. An analysis of five isogenic strains shows that cell cycle phase lengths are independent of cell ploidy and mating type. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSPC51A..05L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSPC51A..05L">Insights Into Intermediate Ocean Barium Cycling From Deep-Sea Bamboo Coral Records on the California Margin</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> LaVigne, M.; Serrato Marks, G.; Freiberger, M. M.; Miller, H. R.; Hill, T. M.; McNichol, A. P.; Lardie Gaylord, M. 2016-02-01 Dissolved barium (BaSW) has been linked to several biogeochemical processes such as the cycling and export of nutrients, organic carbon (Corg), and barite in surface and intermediate oceans. The dynamic nature of barium cycling in the water column has been demonstrated on short timescales (days-weeks) while sedimentary records have documented geologic-scale changes in barite preservation driven by export production. Our understanding of how inter-annual-decadal scale climate variability impacts these biogeochemical processes currently lacks robust instrumental and paleoceanographic records. Recent work has calibrated and demonstrated the reproducibility of a new BaSW proxy in California Current System (CCS) bamboo corals (Ba/Ca) using a coral depth transect spanning the CCS oxygen minimum zone (792-2055m water depth). New `reconnaissance' radiocarbon data identifying the bomb 14C spike in coral proteinaceous nodes and sclerochronological analyses of calcitic internodes are used to assign chronologies to the CCS coral records. Century-long coral records from 900-1500m record 4-7 year long increases in Ba/Ca ( 10-70 nmol/kg BaSW) at depths where rapid barite cycling occurs on day-weekly timescales. The BaSW peaks punctuate the coral records at different time periods and depths and do not coincide with inter-annual/decadal climate transitions (e.g. ENSO/PDO). Stable surface productivity and coral δ15N records indicate that Corg export from CCS surface waters has been relatively constant over the past century. Thus, the inter-annual scale BaSW peaks recorded by the 900-1500m corals more likely reflect periods of decreased barite formation (and/or increased dissolution) via reduced bacterial Corg respiration or barite saturation state. Paleoceanographic BaSW records and continued research on barium cycling in the modern ocean have the potential to elucidate the mechanisms linking intermediate water carbon and barium cycling, climate, and ocean oxygenation in the past. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20889829','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20889829">Natural annual cycle of heat shock protein expression in land snails: desert versus Mediterranean species of Sphincterochila.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Arad, Zeev; Mizrahi, Tal; Goldenberg, Shoshana; Heller, Joseph 2010-10-15 Land snails are subject to daily and seasonal variations in temperature and in water availability, and have evolved annual cycles of activity and aestivation as part of their survival strategy. We tested in the field whether adaptation to different habitats affects the endogenous levels of heat shock proteins (HSPs) in two closely related Sphincterochila snail species, a desiccation-resistant desert species, Sphincterochila zonata, and a Mediterranean-type, desiccation-sensitive species, S. cariosa. We examined HSP levels in various tissues of snails during aestivation and after resumption of activity. Our study shows that, during aestivation, S. cariosa had higher standing stocks of Hsp70 in the foot and the hepatopancreas, and of small HSPs (sHSPs) in all the examined tissues, whereas S. zonata had higher stocks of Hsp70 in the kidney and of Hsp90 in the kidney and in the hepatopancreas. Arousal induced a general upregulation of HSPs, except for Hsp90, the expression of which in the foot was higher during aestivation. We suggest that the stress protein machinery is upregulated during arousal in anticipation of possible oxidative stress ensuing from the accelerating metabolic rate and the exit from the deep hypometabolic state. Our findings support the concept that, in land snails, aestivation and activity represent two distinct physiological states, and suggest that land snails use HSPs as important components of the aestivation mechanism, and as part of their survival strategy during and after arousal. Our study also indicates that adaptation to different habitats results in the development of distinct strategies of HSP expression with likely consequences for the ecology and distribution of land snails. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009SPD....40.2403M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009SPD....40.2403M">The Unusual Minimum of Cycle 23: Observations and Interpretation</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Martens, Petrus C.; Nandy, D.; Munoz-Jaramillo, A. 2009-05-01 The current minimum of cycle 23 is unusual in its long duration, the very low level to which Total Solar Irradiance (TSI) has fallen, and the small flux of the open polar fields. The deep minimum of TSI seems to be related to an unprecedented dearth of polar faculae, and hence to the small amount of open flux. Based upon surface flux transport models it has been suggested that the causes of these phenomena may be an unusually vigorous meridional flow, or even a deviation from Joy's law resulting in smaller Joy angles than usual for emerging flux in cycle 23. There is also the possibility of a connection with the recently inferred emergence in polar regions of bipoles that systematically defy Hale's law. Much speculation has been going on as to the consequences of this exceptional minimum: are we entering another global minimum, is this the end of the 80 year period of exceptionally high solar activity, or is this just a statistical hiccup? Dynamo simulations are underway that may help answer this question. As an aside it must be mentioned that the current minimum of TSI puts an upper limit in the TSI input for global climate simulations during the Maunder minimum, and that a possible decrease in future solar activity will result in a very small but not insignificant reduction in the pace of global warming. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.B31I..05B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.B31I..05B">Water, Carbon, and Nutrient Cycling Following Insect-induced Tree Mortality: How Well Do Plot-scale Observations Predict Ecosystem-Scale Response?</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Brooks, P. D.; Barnard, H. R.; Biederman, J. A.; Borkhuu, B.; Edburg, S. L.; Ewers, B. E.; Gochis, D. J.; Gutmann, E. D.; Harpold, A. A.; Hicke, J. A.; Pendall, E.; Reed, D. E.; Somor, A. J.; Troch, P. A. 2011-12-01 Widespread tree mortality caused by insect infestations and drought has impacted millions of hectares across western North America in recent years. Although previous work on post-disturbance responses (e.g. experimental manipulations, fire, and logging) provides insight into how water and biogeochemical cycles may respond to insect infestations and drought, we find that the unique nature of these drivers of tree mortality complicates extrapolation to larger scales. Building from previous work on forest disturbance, we present a conceptual model of how temporal changes in forest structure impact the individual components of energy balance, hydrologic partitioning, and biogeochemical cycling and the interactions among them. We evaluate and refine this model using integrated observations and process modeling on multiple scales including plot, stand, flux tower footprint, hillslope, and catchment to identify scaling relationships and emergent patterns in hydrological and biogeochemical responses. Our initial results suggest that changes in forest structure at point or plot scales largely have predictable effects on energy, water, and biogeochemical cycles that are well captured by land surface, hydrological, and biogeochemical models. However, observations from flux towers and nested catchments suggest that both the hydrological and biogeochemical effects observed at tree and plot scales may be attenuated or exacerbated at larger scales. Compensatory processes are associated with attenuation (e.g. as transpiration decreases, evaporation and sublimation increase), whereas both attenuation and exacerbation may result from nonlinear scaling behavior across transitions in topography and ecosystem structure that affect the redistribution of energy, water, and solutes. Consequently, the effects of widespread tree mortality on ecosystem services of water supply and carbon sequestration will likely depend on how spatial patterns in mortality severity across the landscape </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012SPIE.8524E..0TC','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012SPIE.8524E..0TC">A decadal observation of vegetation dynamics using multi-resolution satellite images</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Chiang, Yang-Sheng; Chen, Kun-Shan; Chu, Chang-Jen 2012-10-01 Vegetation cover not just affects the habitability of the earth, but also provides potential terrestrial mechanism for mitigation of greenhouse gases. This study aims at quantifying such green resources by incorporating multi-resolution satellite images from different platforms, including Formosat-2(RSI), SPOT(HRV/HRG), and Terra(MODIS), to investigate vegetation fractional cover (VFC) and its inter-/intra-annual variation in Taiwan. Given different sensor capabilities in terms of their spatial coverage and resolution, infusion of NDVIs at different scales was used to determine fraction of vegetation cover based on NDVI. Field campaign has been constantly conducted on a monthly basis for 6 years to calibrate the critical NDVI threshold for the presence of vegetation cover, with test sites covering IPCC-defined land cover types of Taiwan. Based on the proposed method, we analyzed spatio- temporal changes of VFC for the entire Taiwan Island. A bimodal sequence of VFC was observed for intra-annual variation based on MODIS data, with level around 5% and two peaks in spring and autumn marking the principal dual-cropping agriculture pattern in southwestern Taiwan. Compared to anthropogenic-prone variation, the inter-annual VFC (Aug.-Oct.) derived from HRV/HRG/RSI reveals that the moderate variations (3%) and the oscillations were strongly linked with regional climate pattern and major disturbances resulting from extreme weather events. Two distinct cycles (2002-2005 and 2005-2009) were identified in the decadal observations, with VFC peaks at 87.60% and 88.12% in 2003 and 2006, respectively. This time-series mapping of VFC can be used to examine vegetation dynamics and its response associated with short-term and long-term anthropogenic/natural events. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.nist.gov/srd/nist-standard-reference-database-49','NISTDBS'); return false;" href="https://www.nist.gov/srd/nist-standard-reference-database-49">Vapor Compression Cycle Design Program (CYCLE_D)</a> <a target="_blank" href="http://srdata.nist.gov/gateway/gateway?search=keyword">National Institute of Standards and Technology Data Gateway</a> SRD 49 NIST Vapor Compression Cycle Design Program (CYCLE_D) (PC database for purchase) The CYCLE_D database package simulates the vapor compression refrigeration cycles. It is fully compatible with REFPROP 9.0 and covers the 62 single-compound refrigerants . Fluids can be used in mixtures comprising up to five components. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.H31F1268H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.H31F1268H">Water Cycle Missions for the Next Decade</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Houser, P. R. 2013-12-01 The global water cycle describes the circulation of water as a vital and dynamic substance in its liquid, solid, and vapor phases as it moves through the atmosphere, oceans and land. Life in its many forms exists because of water, and modern civilization depends on learning how to live within the constraints imposed by the availability of water. The scientific challenge posed by the need to observe the global water cycle is to integrate in situ and space-borne observations to quantify the key water-cycle state variables and fluxes. The vision to address that challenge is a series of Earth observation missions that will measure the states, stocks, flows, and residence times of water on regional to global scales followed by a series of coordinated missions that will address the processes, on a global scale, that underlie variability and changes in water in all its three phases. The accompanying societal challenge is to foster the improved use of water data and information as a basis for enlightened management of water resources, to protect life and property from effects of extremes in the water cycle. A major change in thinking about water science that goes beyond its physics to include its role in ecosystems and society is also required. Better water-cycle observations, especially on the continental and global scales, will be essential. Water-cycle predictions need to be readily available globally to reduce loss of life and property caused by water-related natural hazards. Building on the 2007 Earth Science Decadal Survey, NASA's Plan for a Climate-Centric Architecture for Earth Observations and Applications from Space , and the 2012 Chapman Conference on Remote Sensing of the Terrestrial Water Cycle, a workshop was held in April 2013 to gather wisdom and determine how to prepare for the next generation of water cycle missions in support of the second Earth Science Decadal Survey. This talk will present the outcomes of the workshop including the intersection between </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19900003172','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19900003172">The onset of the solar active cycle 22</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Ahluwalia, H. S. 1989-01-01 There is a great deal of interest in being able to predict the main characteristics of a solar activity cycle (SAC). One would like to know, for instance, how large the amplitude (R sub m) of a cycle is likely to be, i.e., the annual mean of the sunspot numbers at the maximum of SAC. Also, how long a cycle is likely to last, i.e., its period. It would also be interesting to be able to predict the details, like how steep the ascending phase of a cycle is likely to be. Questions like these are of practical importance to NASA in planning the launch schedule for the low altitude, expensive spacecrafts like the Hubble Space Telescope, the Space Station, etc. Also, one has to choose a proper orbit, so that once launched the threat of an atmospheric drag on the spacecraft is properly taken into account. Cosmic ray data seem to indicate that solar activity cycle 22 will surpass SAC 21 in activity. The value of R sub m for SAC 22 may approach that of SAC 19. It would be interesting to see whether this prediction is borne out. Researchers are greatly encouraged to proceed with the development of a comprehensive prediction model which includes information provided by cosmic ray data. </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active">23</li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active">24</li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.C33C1209N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.C33C1209N">A full year of snow on sea ice observations and simulations - Plans for MOSAiC 2019/20</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Nicolaus, M.; Geland, S.; Perovich, D. K. 2017-12-01 The snow cover on sea on sea ice dominates many exchange processes and properties of the ice covered polar oceans. It is a major interface between the atmosphere and the sea ice with the ocean underneath. Snow on sea ice is known for its extraordinarily large spatial and temporal variability from micro scales and minutes to basin wide scales and decades. At the same time, snow cover properties and even snow depth distributions are among the least known and most difficult to observe climate variables. Starting in October 2019 and ending in October 2020, the international MOSAiC drift experiment will allow to observe the evolution of a snow pack on Arctic sea ice over a full annual cycle. During the drift with one ice floe along the transpolar drift, we will study snow processes and interactions as one of the main topics of the MOSAiC research program. Thus we will, for the first time, be able to perform such studies on seasonal sea ice and relate it to previous expeditions and parallel observations at different locations. Here we will present the current status of our planning of the MOSAiC snow program. We will summarize the latest implementation ideas to combine the field observations with numerical simulations. The field program will include regular manual observations and sampling on the main floe of the central observatory, autonomous recordings in the distributed network, airborne observations in the surrounding of the central observatory, and retrievals of satellite remote sensing products. Along with the field program, numerical simulations of the MOSAiC snow cover will be performed on different scales, including large-scale interaction with the atmosphere and the sea ice. The snow studies will also bridge between the different disciplines, including physical, chemical, biological, and geochemical measurements, samples, and fluxes. The main challenge of all measurements will be to accomplish the description of the full annual cycle. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFMIN11B1028P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFMIN11B1028P">Semantic Data Integration and Ontology Use within the Global Earth Observation System of Systems (GEOSS) Global Water Cycle Data Integration System</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Pozzi, W.; Fekete, B.; Piasecki, M.; McGuinness, D.; Fox, P.; Lawford, R.; Vorosmarty, C.; Houser, P.; Imam, B. 2008-12-01 The inadequacies of water cycle observations for monitoring long-term changes in the global water system, as well as their feedback into the climate system, poses a major constraint on sustainable development of water resources and improvement of water management practices. Hence, The Group on Earth Observations (GEO) has established Task WA-08-01, "Integration of in situ and satellite data for water cycle monitoring," an integrative initiative combining different types of satellite and in situ observations related to key variables of the water cycle with model outputs for improved accuracy and global coverage. This presentation proposes development of the Rapid, Integrated Monitoring System for the Water Cycle (Global-RIMS)--already employed by the GEO Global Terrestrial Network for Hydrology (GTN-H)--as either one of the main components or linked with the Asian system to constitute the modeling system of GEOSS for water cycle monitoring. We further propose expanded, augmented capability to run multiple grids to embrace some of the heterogeneous methods and formats of the Earth Science, Hydrology, and Hydraulic Engineering communities. Different methodologies are employed by the Earth Science (land surface modeling), the Hydrological (GIS), and the Hydraulic Engineering Communities; with each community employing models that require different input data. Data will be routed as input variables to the models through web services, allowing satellite and in situ data to be integrated together within the modeling framework. Semantic data integration will provide the automation to enable this system to operate in near-real-time. Multiple data collections for ground water, precipitation, soil moisture satellite data, such as SMAP, and lake data will require multiple low level ontologies, and an upper level ontology will permit user-friendly water management knowledge to be synthesized. These ontologies will have to have overlapping terms mapped and linked together. so </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/207882-annually-laminated-sequences-internal-structure-some-belgian-stalagmites-importance-paleoclimatology','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/207882-annually-laminated-sequences-internal-structure-some-belgian-stalagmites-importance-paleoclimatology">Annually laminated sequences in the internal structure of some Belgian stalagmites -- Importance for paleoclimatology</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Genty, D.; Quinif, Y. 1996-01-01 Fifteen stalagmites from four caves and one sealed tunnel in southern Belgium are composed of alternations of annually deposited white-porous and dark-compact laminae. This is demonstrated by comparing the number of laminae with the local history of the site for modern stalagmites and with radioisotopic ages for Late Glacial and Holocene stalagmites. Annual cyclicity in the internal structure of these speleothems is explained by the highly seasonal variations of the water excess, which influences underground water flow. Comparison between climatic data and modern stalagmites of a closed tunnel shows that growth laminae can record climatic variations: (1) there is amore » good correlation (R = 0.84) between lamina thickness in a stalagmite and water excess; (2) during years with a high water excess, dark-compact laminae are more developed, which makes the speleothem darker. Vertical successions of several laminae represent microsequences that may have recorded climatic variations with a time resolution of 1/2 year. In a Late Glacial stalagmite, successive laminae microsequences form very regular cycles of 11 years separated by a thick dark-compact lamina. It is supported that, as for modern stalagmites, the thick dark-compact lamina corresponds to a period of high water excess. Hence, this 11-year cycle may reflect a climatic cycle.« less </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.B22A..04W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.B22A..04W">Incorporating Ecosystem Experiments and Observations into Process Models of Forest Carbon and Water Cycles: Challenges and Solutions</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Ward, E. J.; Thomas, R. Q.; Sun, G.; McNulty, S. G.; Domec, J. C.; Noormets, A.; King, J. S. 2015-12-01 Numerous studies, both experimental and observational, have been conducted over the past two decades in an attempt to understand how water and carbon cycling in terrestrial ecosystems may respond to changes in climatic conditions. These studies have produced a wealth of detailed data on key processes driving these cycles. In parallel, sophisticated models of these processes have been formulated to answer a variety of questions relevant to natural resource management. Recent advances in data assimilation techniques offer exciting new possibilities to combine this wealth of ecosystem data with process models of ecosystem function to improve prediction and quantify associated uncertainty. Using forests of the southeastern United States as our focus, we will specify how fine-scale physiological (e.g. half-hourly sap flux) can be scaled up with quantified error for use in models of stand growth and hydrology. This approach represents an opportunity to leverage current and past research from experiments including throughfall displacement × fertilization (PINEMAP), irrigation × fertilization (SETRES), elevated CO2 (Duke and ORNL FACE) and a variety of observational studies in both conifer and hardwood forests throughout the region, using a common platform for data assimilation and prediction. As part of this discussion, we will address variation in dominant species, stand structure, site age, management practices, soils and climate that represent both challenges to the development of a common analytical approach and opportunities to address questions of interest to policy makers and natural resource managers. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.S51C2701H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.S51C2701H">Seasonal Changes in Atmospheric Noise Levels and the Annual Variation in Pigeon Homing Performance</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Hagstrum, J. T.; McIsaac, H. P.; Drob, D. P. 2015-12-01 The remarkable navigational ability of homing pigeons (Columba livia) is influenced by a number of factors, an unknown one of which causes the "Wintereffekt"1 or annual variation in homing performance. Minima in homeward orientation and return speeds have been observed in winter, with maxima in summer, during repetitive pigeon releases from single sites near experimental lofts in Wilhelmshaven, Göttingen, and Munich, Germany, and near Pisa, Italy1-4. Overall the annual variation is more pronounced in northern Germany than Italy4, and both mature and juvenile cohorts respond to this seasonal factor. Older, more experienced pigeons are better at compensating for its effects than naïve ones, but are still affected after numerous releases. The narrow low-frequency band of atmospheric background noise (microbaroms; 0.1-0.3 Hz) also varies with an annual cycle that generally has higher amplitudes in winter than in summer depending on location5. In addition, homing pigeons, and possibly other birds, apparently use infrasonic signals of similar frequency as navigational cues6, and a seasonal variation in background noise levels could cause corresponding changes in signal-to-noise ratios and thus in homing performance. The annual variation in homing performance, however, was not observed during long-term pigeon releases at two sites in eastern North America. The annual and geographic variability in homing performance in the northern hemisphere can be explained to a first order by seasonal changes in infrasonic noise sources related to ocean storm activity, and to the direction and intensity of stratospheric winds. In addition, increased dispersion in departure bearings of individual birds for some North American releases were likely caused by additional infrasonic noise associated with severe weather events during tornado and Atlantic hurricane seasons. 1Kramer, G. & von Saint Paul, U., J. Ornithol. 97, 353-370 (1956); 2Wallraff, H. G., Z. Tierpsychol. 17, 82-113 (1960 </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4122154','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4122154">Skin Cancer, Irradiation, and Sunspots: The Solar Cycle Effect</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> Zurbenko, Igor 2014-01-01 Skin cancer is diagnosed in more than 2 million individuals annually in the United States. It is strongly associated with ultraviolet exposure, with melanoma risk doubling after five or more sunburns. Solar activity, characterized by features such as irradiance and sunspots, undergoes an 11-year solar cycle. This fingerprint frequency accounts for relatively small variation on Earth when compared to other uncorrelated time scales such as daily and seasonal cycles. Kolmogorov-Zurbenko filters, applied to the solar cycle and skin cancer data, separate the components of different time scales to detect weaker long term signals and investigate the relationships between long term trends. Analyses of crosscorrelations reveal epidemiologically consistent latencies between variables which can then be used for regression analysis to calculate a coefficient of influence. This method reveals that strong numerical associations, with correlations >0.5, exist between these small but distinct long term trends in the solar cycle and skin cancer. This improves modeling skin cancer trends on long time scales despite the stronger variation in other time scales and the destructive presence of noise. PMID:25126567 </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AAS...22741801Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AAS...22741801Z">Studying the outflow-core interaction with ALMA Cycle 1 observations of the HH 46/47 molecular outflow</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Zhang, Yichen; Arce, Hector G.; Mardones, Diego; Dunham, Michael; Garay, Guido; Noriega-Crespo, Alberto; Corder, Stuartt; Offner, Stella; Cabrit, Sylvie 2016-01-01 We present ALMA Cycle 1 observations of the HH 46/47 molecular outflow which is driven by a low-mass Class 0/I protostar. Previous ALMA Cycle 0 12CO observation showed outflow cavities produced by the entrainment of ambient gas by the protostellar jet and wide-angle wind. Here we present analysis of observation of 12CO, 13CO, C18O and other species using combined 12m array and ACA observations. The improved angular resolution and sensitivity allow us to detect details of the outflow structure. Specially, we see that the outflow cavity wall is composed of two or more layers of outflowing gas, which separately connect to different shocked regions along the outflow axis inside the cavity, suggesting the outflow cavity wall is composed of multiple shells entrained by a series of jet bow-shock events. The new 13CO and C18O data also allow us to trace relatively denser and slower outflow material than that traced by the 12CO. These species are only detected within about 1 to 2 km/s from the cloud velocity, tracing the outflow to lower velocities than what is possible using only the 12CO emission. Interestingly, the cavity wall of the red lobe appears at very low outflow velocities (as low as ~0.2 km/s). In addition, 13CO and C18O allow us to correct for the CO optical depth, allowing us to obtain more accurate estimates of the outflow mass, momentum and kinetic energy. Applying the optical depth correction significantly increases the previous mass estimate by a factor of 14. The outflow kinetic energy distribution shows that even though the red lobe is mainly entrained by jet bow-shocks, most of the outflow energy is being deposited into the cloud at the base of the outflow cavity rather than around the heads of the bow shocks. The estimated total mass, momentum, and energy of the outflow indicate that the outflow has the ability to disperse the parent core. We found possible evidence for a slowly moving rotating outflow in CS. Our 13CO and C18O observations also trace a </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.G12A..06R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.G12A..06R">Annual Geocenter Motion from Space Geodesy and Models</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Ries, J. C. 2013-12-01 Ideally, the origin of the terrestrial reference frame and the center of mass of the Earth are always coincident. By construction, the origin of the reference frame is coincident with the mean Earth center of mass, averaged over the time span of the satellite laser ranging (SLR) observations used in the reference frame solution, within some level of uncertainty. At shorter time scales, tidal and non-tidal mass variations result in an offset between the origin and geocenter, called geocenter motion. Currently, there is a conventional model for the tidally-coherent diurnal and semi-diurnal geocenter motion, but there is no model for the non-tidal annual variation. This annual motion reflects the largest-scale mass redistribution in the Earth system, so it essential to observe it for a complete description of the total mass transport. Failing to model it can also cause false signals in geodetic products such as sea height observations from satellite altimeters. In this paper, a variety of estimates for the annual geocenter motion are presented based on several different geodetic techniques and models, and a ';consensus' model from SLR is suggested. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFM.H13A0959L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFM.H13A0959L">Emerging Technologies for Integrating Multi-Scale Observations of the Hydrologic Cycle</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Logan, W. S.; Potter, K. W.; Wood, E. F. 2007-12-01 The results are presented of a recent National Research Council study on examining the potential for integrating spaceborne observations with complementary airborne and ground-based observations to gain holistic understanding of hydrologic and related biogeochemical and ecological processes and to help support water and related land-resource management. The study was motivated by the interrelated challenges of population growth, global climate change, and regional changes in land use and land management that will increasingly stress water resources around the world. Meeting these challenges will require significant improvement in our management of water resources, which in turn will require improvements in our capacity to understand and quantify the hydrologic cycle and its interactions with the natural and built environment. Recent and potential future technological innovations in sensors (in-situ, airborne, and space-borne) and sensor networks, cyber-infrastructure, data assimilation, modeling, and decision-support tools offer unprecedented opportunities to improve our capacity to observe, understand, and manage hydrologic systems. The committee investigated a number of aspects to turning this potential into a reality. These included development and field deployment of land-based chemical and biological sensors; the role of airborne remote sensing; interagency gaps between the steps of sensor development, demonstration, and operational deployment; the coordination of federal responsibilities for measurement, monitoring and modeling; and getting the new information to those who can use it. A variety of case studies were used to illustrate the needs and opportunities for new measurement capacity, including hydrologic monitoring in the Everglades, water quantity and quality in the Southern High Plains, malaria in Sub-Saharan Africa, hydroclimatic research in the Arctic, hydrologic extremes and water quality in the Neuse River watershed, and mountain hydrology in the </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ClDy...49.4171G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ClDy...49.4171G">Interannual and low-frequency variability of Upper Indus Basin winter/spring precipitation in observations and CMIP5 models</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Greene, Arthur M.; Robertson, Andrew W. 2017-12-01 An assessment is made of the ability of general circulation models in the CMIP5 ensemble to reproduce observed modes of low-frequency winter/spring precipitation variability in the region of the Upper Indus basin (UIB) in south-central Asia. This season accounts for about two thirds of annual precipitation totals in the UIB and is characterized by "western disturbances" propagating along the eastward extension of the Mediterranean storm track. Observational data are utilized for for spatiotemporal characterization of the precipitation seasonal cycle, to compute seasonalized spectra and finally, to examine teleconnections, in terms of large-scale patterns in sea-surface temperature (SST) and atmospheric circulation. Annual and lowpassed variations are found to be associated primarily with SST modes in the tropical and extratropical Pacific. A more obscure link to North Atlantic SST, possibly related to the North Atlantic Oscillation, is also noted. An ensemble of 31 CMIP5 models is then similarly assessed, using unforced preindustrial multi-century control runs. Of these models, eight are found to reproduce well the two leading modes of the observed seasonal cycle. This model subset is then assessed in the spectral domain and with respect to teleconnection patterns, where a range of behaviors is noted. Two model families each account for three members of this subset. The degree of within-family similarity in behavior is shown to reflect underlying model differences. The results provide estimates of unforced regional hydroclimate variability over the UIB on interannual and decadal scales and the corresponding far-field influences, and are of potential relevance for the estimation of uncertainties in future water availability. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080006637','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080006637">Anticipating Cycle 24 Minimum and Its Consequences</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Wilson, Robert M.; Hathaway, David H. 2007-01-01 On the basis of the 12-mo moving average of monthly mean sunspot number (R) through November 2006, cycle 23 has persisted for 126 mo, having had a minimum of 8.0 in May 1996, a peak of 120.8 in April 2000, and an ascent duration of 47 mo. In November 2006, the 12-mo moving average of monthly mean sunspot number was 12.7, a value just outside the upper observed envelope of sunspot minimum values for the most recent cycles 16-23 (range 3.4-12.3), but within the 90-percent prediction interval (7.8 +/- 6.7). The first spotless day during the decline of cycle 23 occurred in January 2004, and the first occurrence of 10 or more and 20 or more spotless days was February 2006 and April 2007, respectively, inferring that sunspot minimum for cycle 24 is imminent. Through May 2007, 121 spotless days have accumulated. In terms of the weighted mean latitude (weighed by spot area) (LAT) and the highest observed latitude spot (HLS) in November 2006, 12-mo moving averages of these parameters measured 7.9 and 14.6 deg, respectively, these values being the lowest values yet observed during the decline of cycle 23 and being below corresponding mean values found for cycles 16-23. As yet, no high-latitude new-cycle spots have been seen nor has there been an upturn in LAT and HLS, these conditions having always preceded new cycle minimum by several months for past cycles. Together, these findings suggest that cycle 24 s minimum amplitude still lies well beyond November 2006. This implies that cycle 23 s period either will lie in the period "gap" (127-134 mo), a first for a sunspot cycle, or it will be longer than 134 mo, thus making cycle 23 a long-period cycle (like cycle 20) and indicating that cycle 24 s minimum will occur after July 2007. Should cycle 23 prove to be a cycle of longer period, a consequence might be that the maximum amplitude for cycle 24 may be smaller than previously predicted. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1325985-three-dimensional-features-outer-heliosphere-due-coupling-between-interstellar-interplanetary-magnetic-fields-iv-solar-cycle-model-based-ulysses-observations','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1325985-three-dimensional-features-outer-heliosphere-due-coupling-between-interstellar-interplanetary-magnetic-fields-iv-solar-cycle-model-based-ulysses-observations">Three-dimensional features of the outer heliosphere due to coupling between the interstellar and interplanetary magnetic fields. IV. Solar cycle model based on Ulysses observations</a> <a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a> Pogorelov, N. V.; Suess, S. T.; Borovikov, S. N.; ... 2013-06-26 The solar cycle has a profound influence on the solar wind (SW) interaction with the local interstellar medium (LISM) on more than one timescales. Also, there are substantial differences in individual solar cycle lengths and SW behavior within them. The presence of a slow SW belt, with a variable latitudinal extent changing within each solar cycle from rather small angles to 90°, separated from the fast wind that originates at coronal holes substantially affects plasma in the inner heliosheath (IHS)—the SW region between the termination shock (TS) and the heliopause (HP). The solar cycle may be the reason why themore » complicated flow structure is observed in the IHS by Voyager 1. Here, we show that a substantial decrease in the SW ram pressure observed by Ulysses between the TS crossings by Voyager 1 and 2 contributes significantly to the difference in the heliocentric distances at which these crossings occurred. The Ulysses spacecraft is the source of valuable information about the three-dimensional and time-dependent properties of the SW. Its unique fast latitudinal scans of the SW regions make it possible to create a solar cycle model based on the spacecraft in situ measurements. On the basis of our analysis of the Ulysses data over the entire life of the mission, we generated time-dependent boundary conditions at 10 AU from the Sun and applied our MHD-neutral model to perform a numerical simulation of the SW-LISM interaction. We analyzed the global variations in the interaction pattern, the excursions of the TS and the HP, and the details of the plasma and magnetic field distributions in the IHS. The resulting numbers are compared with Voyager data as functions of time in the spacecraft frame. We also discuss solar cycle effects which may be reasons for the recent decrease in the TS particles (ions accelerated to anomalous cosmic-ray energies) flux observed by Voyager 1.« less </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22140113-three-dimensional-features-outer-heliosphere-due-coupling-between-interstellar-interplanetary-magnetic-fields-iv-solar-cycle-model-based-ulysses-observations','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22140113-three-dimensional-features-outer-heliosphere-due-coupling-between-interstellar-interplanetary-magnetic-fields-iv-solar-cycle-model-based-ulysses-observations">THREE-DIMENSIONAL FEATURES OF THE OUTER HELIOSPHERE DUE TO COUPLING BETWEEN THE INTERSTELLAR AND INTERPLANETARY MAGNETIC FIELDS. IV. SOLAR CYCLE MODEL BASED ON ULYSSES OBSERVATIONS</a> <a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a> Pogorelov, N. V.; Zank, G. P.; Suess, S. T. 2013-07-20 The solar cycle has a profound influence on the solar wind (SW) interaction with the local interstellar medium (LISM) on more than one timescales. Also, there are substantial differences in individual solar cycle lengths and SW behavior within them. The presence of a slow SW belt, with a variable latitudinal extent changing within each solar cycle from rather small angles to 90 Degree-Sign , separated from the fast wind that originates at coronal holes substantially affects plasma in the inner heliosheath (IHS)-the SW region between the termination shock (TS) and the heliopause (HP). The solar cycle may be the reasonmore » why the complicated flow structure is observed in the IHS by Voyager 1. In this paper, we show that a substantial decrease in the SW ram pressure observed by Ulysses between the TS crossings by Voyager 1 and 2 contributes significantly to the difference in the heliocentric distances at which these crossings occurred. The Ulysses spacecraft is the source of valuable information about the three-dimensional and time-dependent properties of the SW. Its unique fast latitudinal scans of the SW regions make it possible to create a solar cycle model based on the spacecraft in situ measurements. On the basis of our analysis of the Ulysses data over the entire life of the mission, we generated time-dependent boundary conditions at 10 AU from the Sun and applied our MHD-neutral model to perform a numerical simulation of the SW-LISM interaction. We analyzed the global variations in the interaction pattern, the excursions of the TS and the HP, and the details of the plasma and magnetic field distributions in the IHS. Numerical results are compared with Voyager data as functions of time in the spacecraft frame. We discuss solar cycle effects which may be reasons for the recent decrease in the TS particles (ions accelerated to anomalous cosmic-ray energies) flux observed by Voyager 1.« less </li> <li> <a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=algae&id=EJ758423','ERIC'); return false;" href="https://eric.ed.gov/?q=algae&id=EJ758423">Seeing the Carbon Cycle</a> <a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a> Drouin, Pamela; Welty, David J.; Repeta, Daniel; Engle-Belknap, Cheryl A.; Cramer, Catherine; Frashure, Kim; Chen, Robert 2006-01-01 In this article, the authors present a classroom experiment that was developed to introduce middle school learners to the carbon cycle. The experiment deals with transfer of CO[subscript 2] between liquid reservoirs and the effect CO[subscript 2] has on algae growth. It allows students to observe the influence of the carbon cycle on algae growth,… </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.8848S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.8848S">Annual dynamics of halite precipitation in the Dead Sea: In situ observations and their geological implications</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Sirota, Ido; enzel, Yehouda; Lensky, Nadav G. 2017-04-01 Layered halite sequences deposited in deep basins throughout the geological record. However, analogues of such sequences are commonly studied in sallow environments. Here we study active precipitation of halite layers from the only modern analog for deep, halite-precipitating basin, the hypersaline Dead Sea. In situ observations in the Dead Sea link seasonal thermohaline stratification, halite saturation, and the characteristics of the actively forming halite layers. The spatiotemporal evolution of halite precipitation in the Dead Sea was characterized by means of monthly observations of the i) lake thermohaline stratification (temperature, salinity, and density), ii) degree of halite saturation, and iii) textural evolution of the active halite deposits. We present the observed relationships between textural characteristics of layered halite deposits (i.e. grain size, consolidation, and roughness) and the degree of saturation, which in turn reflected the limnology and hydro-climatology. The lakefloor is divided into two principle environments: A deep, hypolimnetic and a shallow, epilimnetic lakefloor. In the deeper hypolimnetic lakefloor halite continuously precipitates with seasonal variations: (a) during summer, consolidated coarse halite crystals form rough surfaces under slight super-saturation. (b) During winter, unconsolidated, fine halite crystals form smooth seafloor deposits under high supersaturation. The observations also emphasize the thought regarding seasonal alternation of halite crystallization mechanism. The shallow epilimnetic lake floor is highly influenced by the seasonal temperature variations, and by intensive summer dissolution of part of the previous year's halite deposit which results in thin sequences with annual unconformities. This emphasizes the control of temperature seasonality on the precipitated halite layers characteristics. In addition, precipitation of halite in the hypolimnetic floor, on the expense of the dissolution of the </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18171656','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18171656">Transcriptional profiles of the annual growth cycle in Populus deltoides.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Park, Sunchung; Keathley, Daniel E; Han, Kyung-Hwan 2008-03-01 Cycling between vegetative growth and dormancy is an important adaptive mechanism in temperate woody plants. To gain insights into the underlying molecular mechanisms, we carried out global transcription analyses on stem samples from poplar (Populus deltoides Bartr. ex Marsh.) trees grown in the field and in controlled environments. Among seasonal changes in the transcriptome, up-regulation of defense-related genes predominated in early winter, whereas signaling-related genes were up-regulated during late winter. Cluster analysis of the differentially expressed genes showed that plants regulated seasonal growth by integrating environmental factors with development. Short day lengths induced some cold-associated genes without concomitant low temperature exposure, and enhanced the expression of some genes when combined with low temperature exposure. These mechanisms appear to maintain closer synchrony between cold hardiness and climate than would be achieved through responses to temperature alone. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRG..122..528S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRG..122..528S">Assimilation of repeated woody biomass observations constrains decadal ecosystem carbon cycle uncertainty in aggrading forests</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Smallman, T. L.; Exbrayat, J.-F.; Mencuccini, M.; Bloom, A. A.; Williams, M. 2017-03-01 Forest carbon sink strengths are governed by plant growth, mineralization of dead organic matter, and disturbance. Across landscapes, remote sensing can provide information about aboveground states of forests and this information can be linked to models to estimate carbon cycling in forests close to steady state. For aggrading forests this approach is more challenging and has not been demonstrated. Here we apply a Bayesian approach, linking a simple model to a range of data, to evaluate their information content, for two aggrading forests. We compare high information content analyses using local observations with retrievals using progressively sparser remotely sensed information (repeated, single, and no woody biomass observations). The net biome productivity of both forests is constrained to be a net sink with <2 Mg C ha-1 yr-1 variation across the range of inputs. However, the sequestration of particular carbon pool(s) varies with assimilated biomass information. Assimilation of repeated biomass observations reduces uncertainty and/or bias in all ecosystem C pools not just wood, compared to analyses using single or no stock information. As verification, our repeated biomass analysis explains 78-86% of variation in litter dynamics at one forest, while at the second forest total dead organic matter estimates are within observational uncertainty. The uncertainty of retrieved ecosystem traits in the repeated biomass analysis is reduced by up to 50% compared to analyses with less biomass information. This study quantifies the importance of repeated woody observations in constraining the dynamics of both wood and dead organic matter, highlighting the benefit of proposed remote sensing missions. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70032933','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70032933">Annual modulation of seismicity along the San Andreas Fault near Parkfield, CA</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Christiansen, L.B.; Hurwitz, S.; Ingebritsen, S.E. 2007-01-01 We analyze seismic data from the San Andreas Fault (SAF) near Parkfield, California, to test for annual modulation in seismicity rates. We use statistical analyses to show that seismicity is modulated with an annual period in the creeping section of the fault and a semiannual period in the locked section of the fault. Although the exact mechanism for seasonal triggering is undetermined, it appears that stresses associated with the hydrologic cycle are sufficient to fracture critically stressed rocks either through pore-pressure diffusion or crustal loading/ unloading. These results shed additional light on the state of stress along the SAF, indicating that hydrologically induced stress perturbations of ???2 kPa may be sufficient to trigger earthquakes. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950036235&hterms=solar+radiation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dsolar%2Bradiation','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950036235&hterms=solar+radiation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dsolar%2Bradiation">The roles of vertical mixing, solar radiation, and wind stress in a model simulation of the sea surface temperature seasonal cycle in the tropical Pacfic Ocean</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Chen, Dake; Busalacchi, Antonio J.; Rothstein, Lewis M. 1994-01-01 The climatological seasonal cycle of sea surface temperature (SST) in the tropical Pacific is simulated using a newly developed upper ocean model. The roles of vertical mixing, solar radiation, and wind stress are investigated in a hierarchy of numerical experiments with various combinations of vertical mixing algorithms and surface-forcing products. It is found that the large SST annual cycle in the eastern equatorial Pacific is, to a large extent, controlled by the annually varying mixed layer depth which, in turn, is mainly determined by the competing effects of solar radiation and wind forcing. With the application of our hybrid vertical mixing scheme the model-simulated SST annual cycle is much improved in both amplitude and phase as compared to the case of a constant mixed layer depth. Beside the strong effects on vertical mixing, solar radiation is the primary heating term in the surface layer heat budget, and wind forcing influences SST by driving oceanic advective processes that redistribute heat in the upper ocean. For example, the SST seasonal cycle in the western Pacific basically follows the semiannual variation of solar heating, and the cycle in the central equatorial region is significantly affected by the zonal advective heat flux associated with the seasonally reversing South Equatorial Current. It has been shown in our experiments that the amount of heat flux modification needed to eliminate the annual mean SST errors in the model is, on average, no larger than the annual mean uncertainties among the various surface flux products used in this study. Whereas a bias correction is needed to account for remaining uncertainties in the annual mean heat flux, this study demonstrates that with proper treatment of mixed layer physics and realistic forcing functions the seasonal variability of SST is capable of being simulated successfully in response to external forcing without relying on a relaxation or damping formulation for the dominant surface heat </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2008/1186/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2008/1186/">Watershed Regressions for Pesticides (WARP) for Predicting Annual Maximum and Annual Maximum Moving-Average Concentrations of Atrazine in Streams</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Stone, Wesley W.; Gilliom, Robert J.; Crawford, Charles G. 2008-01-01 Regression models were developed for predicting annual maximum and selected annual maximum moving-average concentrations of atrazine in streams using the Watershed Regressions for Pesticides (WARP) methodology developed by the National Water-Quality Assessment Program (NAWQA) of the U.S. Geological Survey (USGS). The current effort builds on the original WARP models, which were based on the annual mean and selected percentiles of the annual frequency distribution of atrazine concentrations. Estimates of annual maximum and annual maximum moving-average concentrations for selected durations are needed to characterize the levels of atrazine and other pesticides for comparison to specific water-quality benchmarks for evaluation of potential concerns regarding human health or aquatic life. Separate regression models were derived for the annual maximum and annual maximum 21-day, 60-day, and 90-day moving-average concentrations. Development of the regression models used the same explanatory variables, transformations, model development data, model validation data, and regression methods as those used in the original development of WARP. The models accounted for 72 to 75 percent of the variability in the concentration statistics among the 112 sampling sites used for model development. Predicted concentration statistics from the four models were within a factor of 10 of the observed concentration statistics for most of the model development and validation sites. Overall, performance of the models for the development and validation sites supports the application of the WARP models for predicting annual maximum and selected annual maximum moving-average atrazine concentration in streams and provides a framework to interpret the predictions in terms of uncertainty. For streams with inadequate direct measurements of atrazine concentrations, the WARP model predictions for the annual maximum and the annual maximum moving-average atrazine concentrations can be used to characterize </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active">24</li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> </div> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active">25</li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11452305','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11452305">Annual monsoon rains recorded by Jurassic dunes.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Loope, D B; Rowe, C M; Joeckel, R M 2001-07-05 Pangaea, the largest landmass in the Earth's history, was nearly bisected by the Equator during the late Palaeozoic and early Mesozoic eras. Modelling experiments and stratigraphic studies have suggested that the supercontinent generated a monsoonal atmospheric circulation that led to extreme seasonality, but direct evidence for annual rainfall periodicity has been lacking. In the Mesozoic era, about 190 million years ago, thick deposits of wind-blown sand accumulated in dunes of a vast, low-latitude desert at Pangaea's western margin. These deposits are now situated in the southwestern USA. Here we analyse slump masses in the annual depositional cycles within these deposits, which have been described for some outcrops of the Navajo Sandstone. Twenty-four slumps, which were generated by heavy rainfall, appear within one interval representing 36 years of dune migration. We interpret the positions of 20 of these masses to indicate slumping during summer monsoon rains, with the other four having been the result of winter storms. The slumped lee faces of these Jurassic dunes therefore represent a prehistoric record of yearly rain events. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5636115','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5636115">How annual course of photoperiod shapes seasonal behavior of diploid and triploid oysters, Crassostrea gigas</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> Payton, Laura; Sow, Mohamedou; Massabuau, Jean-Charles; Ciret, Pierre 2017-01-01 In this work, we study if ploidy (i.e. number of copies of chromosomes) in the oyster Crassostrea gigas may introduce differences in behavior and in its synchronization by the annual photoperiod. To answer to the question about the effect of the seasonal course of the photoperiod on the behavior of C. gigas according to its ploidy, we quantified valve activity by HFNI valvometry in situ for 1 year in both diploid and triploid oysters. Chronobiological analyses of daily, tidal and lunar rhythms were performed according the annual change of the photoperiod. In parallel, growth and gametogenesis status were measured and spawning events were detected by valvometry. The results showed that triploids had reduced gametogenesis, without spawning events, and approximately three times more growth than diploids. These differences in physiological efforts could explain the result that photoperiod (daylength and/or direction of daylength) differentially drives and modulates seasonal behavior of diploid and triploid oysters. Most differences were observed during long days (spring and summer), where triploids showed longer valve opening duration but lower opening amplitude, stronger daily rhythm and weaker tidal rhythm. During this period, diploids did major gametogenesis and spawning whereas triploids did maximal growth. Differences were also observed in terms of moonlight rhythmicity and neap-spring tidal cycle rhythmicity. We suggest that the seasonal change of photoperiod differentially synchronizes oyster behavior and biological rhythms according to physiological needs based on ploidy. PMID:29020114 </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29020114','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29020114">How annual course of photoperiod shapes seasonal behavior of diploid and triploid oysters, Crassostrea gigas.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Payton, Laura; Sow, Mohamedou; Massabuau, Jean-Charles; Ciret, Pierre; Tran, Damien 2017-01-01 In this work, we study if ploidy (i.e. number of copies of chromosomes) in the oyster Crassostrea gigas may introduce differences in behavior and in its synchronization by the annual photoperiod. To answer to the question about the effect of the seasonal course of the photoperiod on the behavior of C. gigas according to its ploidy, we quantified valve activity by HFNI valvometry in situ for 1 year in both diploid and triploid oysters. Chronobiological analyses of daily, tidal and lunar rhythms were performed according the annual change of the photoperiod. In parallel, growth and gametogenesis status were measured and spawning events were detected by valvometry. The results showed that triploids had reduced gametogenesis, without spawning events, and approximately three times more growth than diploids. These differences in physiological efforts could explain the result that photoperiod (daylength and/or direction of daylength) differentially drives and modulates seasonal behavior of diploid and triploid oysters. Most differences were observed during long days (spring and summer), where triploids showed longer valve opening duration but lower opening amplitude, stronger daily rhythm and weaker tidal rhythm. During this period, diploids did major gametogenesis and spawning whereas triploids did maximal growth. Differences were also observed in terms of moonlight rhythmicity and neap-spring tidal cycle rhythmicity. We suggest that the seasonal change of photoperiod differentially synchronizes oyster behavior and biological rhythms according to physiological needs based on ploidy. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998DPS....30.0603S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998DPS....30.0603S">The Dust Cycle Observed by Pathfinder</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Smith, P. H.; Lemmon, M. T.; Tomasko, M. G. 1998-09-01 The Imager for Mars Pathfinder observed the Sun through special filters nearly every sol throughout the 83 sol mission; a total of 1733 images of the Sun have been obtained. Optical depths at four wavelengths (450, 670, 883, and 989 nm) steadily increased from 0.4 to 0.6 during the mission (Ls 145-185). Comparing observations taken in the morning to those from the afternoon shows a general variability with the morning haze being somewhat thicker by 0.1 optical depths. Typically, the trend is more pronounced in the blue wavelength band; we interpret this to be the influence of a high level haze of water ice crystals that forms in the early morning and evaporates during the day. Small, Rayleigh scattering crystals explains the spectral signature that we measure. It may be that this upper haze layer is associated with the small, ice crystals seen by Mariner 9, the Viking orbiters, and the Phobos orbiter. UV images taken by HST show strong limb brightening that can be explained by this high level ice. Calculations of the haze lifetimes given the sedimentation rates measured from the Rover's solar panels and the magnetic targets, suggest that the haze should completely deposit onto the surface within 120 days. A primary mechanism for replenishing the haze may be the dust devils that were observed during the sol 11 gallery pan. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018BGeo...15..847G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018BGeo...15..847G">Explaining CO2 fluctuations observed in snowpacks</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Graham, Laura; Risk, David 2018-02-01 Winter soil carbon dioxide (CO2) respiration is a significant and understudied component of the global carbon (C) cycle. Winter soil CO2 fluxes can be surprisingly variable, owing to physical factors such as snowpack properties and wind. This study aimed to quantify the effects of advective transport of CO2 in soil-snow systems on the subdiurnal to diurnal (hours to days) timescale, use an enhanced diffusion model to replicate the effects of CO2 concentration depletions from persistent winds, and use a model-measure pairing to effectively explore what is happening in the field. We took continuous measurements of CO2 concentration gradients and meteorological data at a site in the Cape Breton Highlands of Nova Scotia, Canada, to determine the relationship between wind speeds and CO2 levels in snowpacks. We adapted a soil CO2 diffusion model for the soil-snow system and simulated stepwise changes in transport rate over a broad range of plausible synthetic cases. The goal was to mimic the changes we observed in CO2 snowpack concentration to help elucidate the mechanisms (diffusion, advection) responsible for observed variations. On subdiurnal to diurnal timescales with varying winds and constant snow levels, a strong negative relationship between wind speed and CO2 concentration within the snowpack was often identified. Modelling clearly demonstrated that diffusion alone was unable to replicate the high-frequency CO2 fluctuations, but simulations using above-atmospheric snowpack diffusivities (simulating advective transport within the snowpack) reproduced snow CO2 changes of the observed magnitude and speed. This confirmed that wind-induced ventilation contributed to episodic pulsed emissions from the snow surface and to suppressed snowpack concentrations. This study improves our understanding of winter CO2 dynamics to aid in continued quantification of the annual global C cycle and demonstrates a preference for continuous wintertime CO2 flux measurement systems. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JGRA..119.5800P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JGRA..119.5800P">Observations and simulations of the ionospheric lunar tide: Seasonal variability</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Pedatella, N. M. 2014-07-01 The seasonal variability of the ionospheric lunar tide is investigated using a combination of Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) observations and thermosphere-ionosphere-mesosphere electrodynamics general circulation model (TIME-GCM) simulations. The present study focuses on the seasonal variability of the lunar tide in the ionosphere and its potential connection to the occurrence of stratosphere sudden warmings (SSWs). COSMIC maximum F region electron density (NmF2) and total electron content observations reveal a primarily annual variation of the ionospheric lunar tide, with maximum amplitudes occurring at low latitudes during December-February. Simulations of the lunar tide climatology in TIME-GCM display a similar annual variability as the COSMIC observations. This leads to the conclusion that the annual variability of the lunar tide in the ionosphere is not solely due to the occurrence of SSWs. Rather, the annual variability of the lunar tide in the ionosphere is generated by the seasonal variability of the lunar tide at E region altitudes. However, compared to the observations, the ionospheric lunar tide annual variability is weaker in the climatological simulations which is attributed to the occurrence of SSWs during the majority of the years included in the observations. Introducing a SSW into the TIME-GCM simulation leads to an additional enhancement of the lunar tide during Northern Hemisphere winter, increasing the lunar tide annual variability and resulting in an annual variability that is more consistent with the observations. The occurrence of SSWs can therefore potentially bias lunar tide climatologies, and it is important to consider these effects in studies of the lunar tide in the atmosphere and ionosphere. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4183309','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4183309">Biogeographic variation in evergreen conifer needle longevity and impacts on boreal forest carbon cycle projections</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> Reich, Peter B.; Rich, Roy L.; Lu, Xingjie; Wang, Ying-Ping; Oleksyn, Jacek 2014-01-01 Leaf life span is an important plant trait associated with interspecific variation in leaf, organismal, and ecosystem processes. We hypothesized that intraspecific variation in gymnosperm needle traits with latitude reflects both selection and acclimation for traits adaptive to the associated temperature and moisture gradient. This hypothesis was supported, because across 127 sites along a 2,160-km gradient in North America individuals of Picea glauca, Picea mariana, Pinus banksiana, and Abies balsamea had longer needle life span and lower tissue nitrogen concentration with decreasing mean annual temperature. Similar patterns were noted for Pinus sylvestris across a north–south gradient in Europe. These differences highlight needle longevity as an adaptive feature important to ecological success of boreal conifers across broad climatic ranges. Additionally, differences in leaf life span directly affect annual foliage turnover rate, which along with needle physiology partially regulates carbon cycling through effects on gross primary production and net canopy carbon export. However, most, if not all, global land surface models parameterize needle longevity of boreal evergreen forests as if it were a constant. We incorporated temperature-dependent needle longevity and %nitrogen, and biomass allocation, into a land surface model, Community Atmosphere Biosphere Land Exchange, to assess their impacts on carbon cycling processes. Incorporating realistic parameterization of these variables improved predictions of canopy leaf area index and gross primary production compared with observations from flux sites. Finally, increasingly low foliage turnover and biomass fraction toward the cold far north indicate that a surprisingly small fraction of new biomass is allocated to foliage under such conditions. PMID:25225397 </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.B44B..05M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.B44B..05M">Iron cycling under oscillatory redox conditions: from observations to processes</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Meile, C. D.; Chen, C.; Barcellos, D.; Wilmoth, J.; Thompson, A. 2017-12-01 Fe oxyhydroxides play a critical role in soils through their role as structural entities, their high sorption capacity, their role as terminal electron acceptors in the respiration of organic matter, as well as their potential to affect the reactivity of that organic matter. In soils that undergo repeated fluctuations in O2 concentrations, soil iron undergoes transformations between reduced and oxidized forms. The rate of Fe(II) oxidation can govern the nature of Fe(III) oxyhydroxides formed, and hence can affect rates of OC mineralization under suboxic conditions. But it remains unclear if this same behavior occurs in soils, where Fe(II) is mainly present as surface complexes. We documented the impact of such redox oscillations on iron cycling through targeted experiments, in which the magnitude and frequency of redox oscillations were varied systematically on soils from the Luquillo Critical Zone Observatory, Puerto Rico. Our observations demonstrated that higher O2 concentrations led to a faster Fe(II) oxidation and resulted in less crystalline Fe(III)-oxyhydroxides than lower O2 concentrations. We further studied the dynamics of iron phases by amending soil slurries with isotopically-labeled 57Fe(II) and developed a numerical model to quantify the individual processes. Our model showed a higher rate of Fe(III) reduction and increased sorption capacity following the oxidation of Fe(II) at high O2 levels than at low O2 levels, and revealed rapid Fe atom exchange between solution and solid phase. Concurrent measurements of CO2 in our oscillation experiments further illustrated the importance O2 fluctuations on coupled Fe-C dynamics. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.A23F0286P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.A23F0286P">Relationships between Tropical Rainfall Events and Regional Annual Rainfall Anomalies</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Painter, C.; Varble, A.; Zipser, E. J. 2016-12-01 so as a function of annual rainfall in most tropical regions. However, select land regions such as the Congo fail to follow this tendency. Changes in seasonal and diurnal cycles of PF characteristics as a function of regional annual rainfall anomaly are also analyzed. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.3265P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.3265P">Processes Affecting the Annual Surface Energy Budget at High-Latitude Terrestrial Sites</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Persson, P. O. G.; Stone, R. S.; Grachev, A.; Matrosova, L. 2012-04-01 Instrumentation at four Study of Environmental Arctic Change (SEARCH) sites (Barrow, Eureka, Alert, and Tiksi) have been enhanced in the past 6 years, including during the 2007-2008 IPY. Data from these sites are used to investigate the annual cycle of the surface energy budget (SEB), its coupling to atmospheric processes, and for Alert, its interannual variability. The comprehensive data sets are useful for showing interactions between the atmosphere, surface, and soil at high temporal resolution throughout the annual cycle. Processes that govern the SEB variability at each site are identified, and their impacts on the SEB are quantified. For example, mesoscale modulation of the SEB caused by forcing from the local terrain (downslope wind events) and coastlines (sea and land breezes) are significant at Alert and Eureka, with these processes affecting both radiative, turbulent, and ground heat flux terms in the SEB. Sub-seasonal and interannual variations in atmospheric processes and SEB impact soil thermal structures, such as the depth and timing of the summer active layer. These analyses provide an improved understanding of the processes producing changes in surface and soil temperature, linking them through the SEB as affected by atmospheric processes. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140002703','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140002703">Meridional Flow Variations in Cycles 23 and 24: Active Latitude Control of Sunspot Cycle Amplitudes</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Hathaway, David H.; Upton, Lisa 2013-01-01 We have measured the meridional motions of magnetic elements observed in the photosphere over sunspot cycles 23 and 24 using magnetograms from SOHO/MDI and SDO/HMI. Our measurements confirm the finding of Komm, Howard, and Harvey (1993) that the poleward meridional flow weakens at cycle maxima. Our high spatial and temporal resolution analyses show that this variation is in the form of a superimposed inflow toward the active latitudes. This inflow is weaker in cycle 24 when compared to the inflow in 23, the stronger cycle. This systematic modulation of the meridional flow can modulate the amplitude of the following sunspot cycle through its influence on the Sun's polar fields. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20080030231&hterms=Qbo&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DQbo','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20080030231&hterms=Qbo&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DQbo">Inter-annual and Long-term Temperature Variations in the Mesopause Region at High Latitudes Generated by the Stratospheric QBO</a> <a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a> Mayr, Hans G.; Mengel, John G.; Huang, Frank T. 2007-01-01 The Numerical Spectral Model (NSM) simulates the Quasi-biennial Oscillation (QBO) that dominates the zonal circulation of the lower stratosphere at low latitudes. In the model, the QBO is generated with parameterized small-scale gravity waves (GW), which are partially augmented in 3D with planetary waves owing to baroclinic instability. Due to GW filtering, the QBO extends into the upper mesosphere, evident in UARS zonal wind and TIMED temperature measurements. While the QBO zonal winds are confined to equatorial latitudes, even in simulations with latitude-independent wave source, the associated temperature variations extend to high latitudes. The meridional circulation redistributes some of the QBO energy to focus it partially onto the Polar Regions. The resulting QBO temperature variations away from the equator tend to increase at higher altitudes to produce inter-annual variations that can exceed 5 K in the polar mesopause region -- and our 3D model simulations show that the effect is variable from year to year and can produce large differences between the two hemispheres, presumably due to interactions involving the seasonal variations. Modeling studies with the NSM have shown that long-term variations can also be generated by the QBO interacting with the seasonal cycles through OW node-filtering. A 30-month QBO, optimally synchronized by the 6-month Semi-Annual Oscillation (SAO), thus produces a 5-year or semi-decadal (SD) oscillation -- and observational evidence for that has been provided by a recent analysis of stratospheric NCEP data. In a simulation with the 2D version of the NSM, this SD oscillation extends into the upper mesosphere, and we present results to show that the related temperature variations could contribute significantly to the long-term variations of the polar mesopause region. Quasi-decadal variations could furthermore arise from the modeled solar cycle modulations of the QBO and 12-month annual oscillation. Our numerical results are </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GeoRL..42.4032N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GeoRL..42.4032N">Quantifying subtropical North Pacific gyre mixed layer primary productivity from Seaglider observations of diel oxygen cycles</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Nicholson, David P.; Wilson, Samuel T.; Doney, Scott C.; Karl, David M. 2015-05-01 Using autonomous underwater gliders, we quantified diurnal periodicity in dissolved oxygen, chlorophyll, and temperature in the subtropical North Pacific near the Hawaii Ocean Time-series (HOT) Station ALOHA during summer 2012. Oxygen optodes provided sufficient stability and precision to quantify diel cycles of average amplitude of 0.6 µmol kg-1. A theoretical diel curve was fit to daily observations to infer an average mixed layer gross primary productivity (GPP) of 1.8 mmol O2 m-3 d-1. Cumulative net community production (NCP) over 110 days was 500 mmol O2 m-2 for the mixed layer, which averaged 57 m in depth. Both GPP and NCP estimates indicated a significant period of below-average productivity at Station ALOHA in 2012, an observation confirmed by 14C productivity incubations and O2/Ar ratios. Given our success in an oligotrophic gyre where biological signals are small, our diel GPP approach holds promise for remote characterization of productivity across the spectrum of marine environments. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://www.aapcc.org/annual-reports/','NIH-MEDLINEPLUS'); return false;" href="http://www.aapcc.org/annual-reports/">AAPCC Annual Reports</a> <a target="_blank" href="http://medlineplus.gov/">MedlinePlus</a> ... Annual Report 2000 Annual Report 1999 Annual Report Poison Data National Poison Data System Uses for NPDS ... Elements NPDS FAQs Annual Reports Find Your Local Poison Center Poison centers offer free, private, confidential medical ... </li> <li> <a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70187191','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70187191">Climate, soil water storage, and the average annual water balance</a> <a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a> Milly, P.C.D. 1994-01-01 This paper describes the development and testing of the hypothesis that the long-term water balance is determined only by the local interaction of fluctuating water supply (precipitation) and demand (potential evapotranspiration), mediated by water storage in the soil. Adoption of this hypothesis, together with idealized representations of relevant input variabilities in time and space, yields a simple model of the water balance of a finite area having a uniform climate. The partitioning of average annual precipitation into evapotranspiration and runoff depends on seven dimensionless numbers: the ratio of average annual potential evapotranspiration to average annual precipitation (index of dryness); the ratio of the spatial average plant-available water-holding capacity of the soil to the annual average precipitation amount; the mean number of precipitation events per year; the shape parameter of the gamma distribution describing spatial variability of storage capacity; and simple measures of the seasonality of mean precipitation intensity, storm arrival rate, and potential evapotranspiration. The hypothesis is tested in an application of the model to the United States east of the Rocky Mountains, with no calibration. Study area averages of runoff and evapotranspiration, based on observations, are 263 mm and 728 mm, respectively; the model yields corresponding estimates of 250 mm and 741 mm, respectively, and explains 88% of the geographical variance of observed runoff within the study region. The differences between modeled and observed runoff can be explained by uncertainties in the model inputs and in the observed runoff. In the humid (index of dryness <1) parts of the study area, the dominant factor producing runoff is the excess of annual precipitation over annual potential evapotranspiration, but runoff caused by variability of supply and demand over time is also significant; in the arid (index of dryness >1) parts, all of the runoff is caused by variability </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMOS24B..04R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMOS24B..04R">SPURS-2: Multi-month and multi-scale observations of upper ocean salinity in a rain-dominated salinity minimum region.</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Rainville, L.; Farrar, J. T.; Shcherbina, A.; Centurioni, L. R. 2017-12-01 The Salinity Processes in the Upper-ocean Regional Study (SPURS) is a program aimed at understanding the patterns and variability of sea surface salinity. Following the first SPURS program in an evaporation-dominated region (2012-2013), the SPURS-2 program targeted wide range of spatial and temporal scales associated with processes controlling salinity in the rain-dominated Eastern Pacific Fresh Pool. Autonomous instruments were delivered in August and September 2016 using research vessels conducted observations over one complete annual cycle. The SPURS-2 field program used coordinated observations from many different autonomous platforms, and a mix of Lagrangian and Eulerian approaches. Here we discuss the motivation, implementation, and the early of SPURS-2. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21330022','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21330022">Life cycle implications of urban green infrastructure.</a> <a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a> Spatari, Sabrina; Yu, Ziwen; Montalto, Franco A 2011-01-01 Low Impact Development (LID) is part of a new paradigm in urban water management that aims to decentralize water storage and movement functions within urban watersheds. LID strategies can restore ecosystem functions and reduce runoff loadings to municipal water pollution control facilities (WPCF). This research examines the avoided energy and greenhouse gas (GHG) emissions of select LID strategies using life cycle assessment (LCA) and a stochastic urban watershed model. We estimate annual energy savings and avoided GHG emissions of 7.3 GJ and 0.4 metric tons, respectively, for a LID strategy implemented in a neighborhood in New York City. Annual savings are small compared to the energy and GHG intensity of the LID materials, resulting in slow environmental payback times. This preliminary analysis suggests that if implemented throughout an urban watershed, LID strategies may have important energy cost savings to WPCF, and can make progress towards reducing their carbon footprint. Copyright © 2011 Elsevier Ltd. All rights reserved. </li> <li> <a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2939751','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2939751">Physiology and Endocrinology of the Ovarian Cycle in Macaques</a> <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a> Weinbauer, Gerhard F.; Niehoff, Marc; Niehaus, Michael; Srivastav, Shiela; Fuchs, Antje; Van Esch, Eric; Cline, J. Mark 2009-01-01 Macaques provide excellent models for preclinical testing and safety assessment of female reproductive toxicants. Currently, cynomolgus monkeys are the predominant species for (reproductive) toxicity testing. Marmosets and rhesus monkeys are being used occasionally. The authors provide a brief review on physiology and endocrinology of the cynomolgus monkey ovarian cycle, practical guidance on assessment and monitoring of ovarian cyclicity, and new data on effects of social housing on ovarian cyclicity in toxicological studies. In macaques, cycle monitoring is achieved using daily vaginal smears for menstruation combined with cycle-timed frequent sampling for steroid and peptide hormone analysis. Owing to requirements of frequent and timed blood sampling, it is not recommended to incorporate these special evaluations into a general toxicity study design. Marmosets lack external signs of ovarian cyclicity, and cycle monitoring is done by regular determinations of progesterone. Cynomolgus and marmoset monkeys do not exhibit seasonal variations in ovarian activity, whereas such annual rhythm is pronounced in rhesus monkeys. Studies on pair- and group-housed cynomolgus monkeys revealed transient alterations in the duration and endocrinology of the ovarian cycle followed by return to normal cyclicity after approximately six months. This effect is avoided if the animals had contact with each other prior to mingling. These experiments also demonstrated that synchronization of ovarian cycles did not occur. PMID:20852722 </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMGC13L..07M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMGC13L..07M">Climate change influences on the annual onset of Lyme disease in the United States</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Monaghan, A. J.; Moore, S. M.; Sampson, K. M.; Beard, C. B.; Eisen, R. J. 2015-12-01 Lyme disease is the most commonly reported vector-borne illness in the United States. Lyme disease occurrence is highly seasonal and the annual springtime onset of cases is modulated by meteorological conditions in preceding months. A meteorological-based empirical model for Lyme disease onset week in the United States is driven with downscaled simulations from five global climate models and four greenhouse gas emissions scenarios to project the impacts of 21st century climate change on the annual onset week of Lyme disease. Projections are made individually and collectively for the 12 eastern States where >90% of cases occur. The national average annual onset week of Lyme disease is projected to become 0.4-0.5 weeks earlier for 2025-2040 (p<0.05), and 0.7-1.9 weeks earlier for 2065-2080 (p<0.01), with the largest shifts for scenarios with the highest greenhouse gas emissions. The more southerly mid-Atlantic States exhibit larger shifts (1.0-3.5 weeks) compared to the Northeastern and upper Midwestern States (0.2-2.3 weeks) by 2065-2080. Winter and spring temperature increases primarily cause the earlier onset. Greater spring precipitation and changes in humidity partially counteract the temperature effects. The model does not account for the possibility that abrupt shifts in the life cycle of Ixodes scapularis, the primary vector of the Lyme disease spirochete Borrelia burgdorferi in the eastern United States, may alter the disease transmission cycle in unforeseen ways. The results suggest 21st century climate change will make environmental conditions suitable for earlier annual onset of Lyme disease cases in the United States with possible implications for the timing of public health interventions. </li> <li> <a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ACPD...14.4745H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ACPD...14.4745H">Organosulfates and organic acids in Arctic aerosols: speciation, annual variation and concentration levels</a> <a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a> Hansen, A. M. K.; Kristensen, K.; Nguyen, Q. T.; Zare, A.; Cozzi, F.; Nøjgaard, J. K.; Skov, H.; Brandt, J.; Christensen, J. H.; Ström, J.; Tunved, P.; Krejci, R.; Glasius, M. 2014-02-01 Sources, composition and occurrence of secondary organic aerosols (SOA) in the Arctic were investigated at Zeppelin Mountain, Svalbard, and Station Nord, northeast Greenland, during the full annual cycle of 2008 and 2010 respectively. We focused on the speciation of three types of SOA tracers: organic acids, organosulfates and nitrooxy organosulfates from both anthropogenic and biogenic precursors, here presenting organosulfate concentrations and compositions during a full annual cycle and chemical speciation of organosulfates in Arctic aerosols for the first time. Aerosol samples were analysed using High Performance Liquid Chromatography coupled to a quadrupole Time-of-Flight mass spectrometer (HPLC-q-TOF-MS). A total of 11 organic acids (terpenylic acid, benzoic acid, phthalic acid, pinic acid, suberic acid, azelaic acid, adipic acid, pimelic acid, pinonic acid, diaterpenylic acid acetate (DTAA) and 3-methyl-1,2,3-butanetricarboxylic acid (MBTCA)), 12 organosulfates and one nitrooxy organosulfate were identified at the two sites. Six out of the 12 organosulfates are reported for the first time. Concentrations of organosulfates follow a distinct annual pattern at Station Nord, where high concentration were observed in late winter and early spring, with a mean total concentration of 47 (±14) ng m-3, accounting for 7 (±2)% of total organic matter, contrary to a considerably lower organosulfate mean concentration of 2 (±3) ng m-3 (accounting for 1 (±1)% of total organic matter) observed during the rest of the year. The organic acids followed the same temporal trend as the organosulfates at Station Nord; however the variations in organic acid concentrations were less pronounced, with a total mean organic acid concentration of 11.5 (±4) ng m-3 (accounting for 1.7 (±0.6)% of total organic matter) in late winter and early spring, and 2.2 (±1) ng m-3 (accounting for 0.9 (±0.4)% of total organic matter) during the rest of the year. 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Sample records for observed annual cycle