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Sample records for late summer vertical

  1. Under-ice turbulent microstructure and upper ocean vertical fluxes in the Makarov and Eurasian basins, Arctic Ocean, during late spring and late summer / autumn in 2015

    NASA Astrophysics Data System (ADS)

    Rabe, Benjamin; Janout, Markus; Graupner, Rainer; Hoelemann, Jens; Hampe, Hendrik; Hoppmann, Mario; Horn, Myriel; Juhls, Bennet; Korhonen, Meri; Nikolopoulos, Anna; Pisarev, Sergey; Randelhoff, Achim; Savy, Jean-Philippe; Villacieros Robineau, Nicolas

    2017-04-01

    The Arctic Ocean is generally assumed to be fairly quiescent when compared to many other oceans. The sea-ice cover, a strong halocline and a shallow, cold mixed-layer prevents much of the ocean to be affected by atmospheric conditions and properties of the ocean mixed-layer. In turn, the mixed-layer and the sea-ice is largely isolated from the warm layer of Atlantic origin below by the lower halocline. Yet, the content of heat, freshwater and biologically important nutrients differs strongly between these different layers. Hence, it is crucial to be able to estimate vertical fluxes of salt, heat and nutrients to understand variability in the upper Arctic Ocean and the sea-ice, including the ecosystem. Yet, it is difficult to obtain direct flux measurements, and estimates are sparse. We present several sets of under-ice turbulent microstructure profiles in the Eurasian and Makarov Basin of the Arctic Ocean from two expeditions, in 2015. These cover melt during late spring north of Svalbard and freeze-up during late summer / autumn across the Eurasian and Makarov basins. Our results are presented against a background of the anomalously warm atmospheric conditions during summer 2015 followed by unusually low temperatures in September. 4 - 24 h averages of the measurements generally show elevated dissipation rates at the base of the mixed-layer. We found highest levels of dissipation near the Eurasian continental slope and smaller peaks in the profiles where Bering Sea Summer Water (sBSW) lead to additional stratification within the upper halocline in the Makarov Basin. The elevated levels of dissipation associated with sBSW and the base of the mixed-layer were associated with the relatively low levels of vertical eddy diffusivity. We discuss these findings in the light of the anomalous conditions in the upper ocean, sea-ice and the atmosphere during 2015 and present estimates of vertical fluxes of heat, salt and other dissolved substances measured in water samples.

  2. The use of early summer mosquito surveillance to predict late summer West Nile virus activity

    USGS Publications Warehouse

    Ginsberg, Howard S.; Rochlin, Ilia; Campbell, Scott R.

    2010-01-01

    Utility of early-season mosquito surveillance to predict West Nile virus activity in late summer was assessed in Suffolk County, NY. Dry ice-baited CDC miniature light traps paired with gravid traps were set weekly. Maximum-likelihood estimates of WNV positivity, minimum infection rates, and % positive pools were generally well correlated. However, positivity in gravid traps was not correlated with positivity in CDC light traps. The best early-season predictors of WNV activity in late summer (estimated using maximum-likelihood estimates of Culex positivity in August and September) were early date of first positive pool, low numbers of mosquitoes in July, and low numbers of mosquito species in July. These results suggest that early-season entomological samples can be used to predict WNV activity later in the summer, when most human cases are acquired. Additional research is needed to establish which surveillance variables are most predictive and to characterize the reliability of the predictions.

  3. Sea Surface Temperature Forcing of the Late Indian Summer Monsoon

    NASA Astrophysics Data System (ADS)

    Terray, P.; Delecluse, P.; Labattu, S.; Terray, L.; Cassou, C.

    2002-12-01

    This paper uses recent historical data and Atmospheric General Circulation Model (AGCM) simulations in order to assess the relationships between interannual variability of the Indian Summer Monsoon (ISM) and Sea Surface Temperature (SST) anomaly patterns over the Indian and Pacific oceans. The focus is on the predictability of ISM rainfall and circulation, and its links to local (Indian Ocean) and remote (Pacific Ocean) SST forcing. Interannual variability of ISM rainfall and dynamical indices for the traditional summer monsoon season (June-September) are strongly influenced by rainfall and circulation anomalies observed during August and September, or the Late Indian Summer Monsoon (LISM). Anomalous monsoons are linked to well-defined LISM rainfall and large-scale circulation anomalies. The whole three-dimensional monsoon circulation, i.e., the east-west Walker and local Hadley circulations, fluctuates during the LISM of anomalous ISM years. LISM circulation is weakened and shifted eastward during weak ISM years. Therefore, we focus on the predictability of the LISM in this study. It is found that southern Indian Ocean SST acts as a major boundary forcing for the LISM system. Strong (weak) LISMs are preceded by significant positive (negative) SST anomalies in the southeastern subtropical Indian Ocean, off Australia. These SST anomalies are highly persistent and affect the northwestward translation of the Mascarene high from austral to boreal summer. The southeastward (northwestward) shift of this subtropical high associated with cold (warm) SST anomalies off Australia causes a weakening (strengthening) of the whole monsoon circulation through a modulation of the local Hadley cell during the LISM. Furthermore, it is suggested that the Mascarene high interacts with the underlying SST anomalies through a positive dynamical feedback mechanism, maintaining its anomalous position during the LISM. Southeastern Indian Ocean SST anomalies during boreal winter are mainly

  4. Late Holocene vertical deformation, Yellowstone National Park, Wyoming

    SciTech Connect

    Locke, W.W.; Meyer, G.A.

    1985-01-01

    Volcano-tectonic deformation has been measured within the Yellowstone caldera using precision leveling techniques. The shorelines represent originally horizontal planes, accumulated deformation of which can be observed as vertical displacement and tilt. Dating of the shorelines allows the calculation of average rates of deformation since and between episodes of shoreline formation. Shoreline elevations projected to perpendiculars to isolines on contemporary uplift correlate well for 12 km across the perpendiculars. Projections to parallels are nearly horizontal for 5 km. 1985 fieldwork will extend this line to 20 km. Both correlations imply that the pattern of contemporary uplift is an accurate model for late Holocene deformation. Maximum late Holocene rates of deformation, as determined form minimum /sup 14/C dates, are 50-75% of contemporary rates. This suggests that late Holocene deformation has 1) been episodic (50-75% of the time), 2) been oscillatory (75-90% up, 10-25% down), or 3) occurred at an increasing rate through time. Tilt and uplift rates are similar, implying little downcutting at the outlet, and rates between shorelines are similar to those since shoreline formation, implying nearly constant average rates of deformation in the past 2500 years. Local deformation has been significant throughout the late Holocene. Episodic deformation in a graben 1 km across has controlled the location of the lake outlet, thus water level. Sharp local warping has deformed some shorelines by 1 mm/yr. These faults may relate to volcanic processes or to the regional tectonic regime.

  5. Late summer zoogeography of the northern Bering and Chukchi seas

    NASA Astrophysics Data System (ADS)

    Sigler, Michael F.; Mueter, Franz J.; Bluhm, Bodil A.; Busby, Morgan S.; Cokelet, Edward D.; Danielson, Seth L.; Robertis, Alex De; Eisner, Lisa B.; Farley, Edward V.; Iken, Katrin; Kuletz, Kathy J.; Lauth, Robert R.; Logerwell, Elizabeth A.; Pinchuk, Alexei I.

    2017-01-01

    Ocean currents, water masses, and seasonal sea ice formation contribute to determining relationships among the biota of the Bering and Chukchi seas. The Bering Sea communicates with the Chukchi Sea via northward advection of water, nutrients, organic matter, and plankton through Bering Strait. We used data from concurrent surveys of zooplankton, pelagic fishes and jellyfish, epibenthic fishes and invertebrates, and seabirds to identify faunal distribution patterns and environmental factors that are related to these faunal distributions within the US portions of the Chukchi Sea shelf and Bering Sea shelf north of Nunivak Island. Regional differences in late summer (August-September) distributions of biota largely reflected the underlying hydrography. Depth, temperature, salinity, stratification, and chlorophyll a, but less so sediment-related or nutrient-related factors, were related to the distributions of the assemblages (zooplankton: depth, salinity, stratification; pelagic fishes and jellyfish: depth, stratification, chlorophyll a; epibenthic fishes and invertebrates: depth, temperature, salinity; seabirds: temperature, salinity, stratification). These six environmental factors that most influenced distributions of zooplankton, pelagic fishes/jellyfish, epibenthic fishes and invertebrate, and seabird assemblages likely can be simplified to three factors reflecting bottom depth, water mass, and their stratification and productivity (which are tightly linked in the study region). The assemblages were principally structured from nearshore to offshore and from south to north. The nearshore to offshore contrast usually was stronger in the south, where the enormous discharge of the Yukon River is more apparent and extends farther offshore, influencing zooplankton, pelagic fish/jellyfish, and seabird assemblages. Some assemblages overlapped spatially (e.g., seabird and zooplankton), indicating shared influential environmental factors or trophic linkages among

  6. [A possible late complication of Mason's vertical gastroplasty: the erosion of the vertical band].

    PubMed

    Rea, Teresa; Sigismondi, Gianni; Di Paolo, Sonia; Mitri, Francesca; Manika, Caterina; Fiordaliso, Michele; Picardi, Nicola

    2008-01-01

    To evaluate possible adverse consequences and complications following the procedure of Mason-McLeans Vertical Banded Gastroplasty (VBG), and in those cases the possibility to be related to a surgical mistake. It is based on a casuistic of more than 180 patients, submitted to this restrictive bariatric surgery in the same institution since 2001. Controls of the prescribed postop follow up revealed a very low rate of complications, as only in three cases, all of them with spontaneous presentation, there was a complication related to the banding. All the observed complications were related to a late postoperative inadequate alimentation for excess of meals, after the immediate orthodox behaviour of the first months. From the comparative evaluation of all the patients submitted to the Mason-McLean procedure it seems of the utmost evidence the importance of a correct alimentation, mainly to the low bulk of the single meal, to avoid complications and obtain the best EWL%. Adherence to the guidelines for the post op alimentation in such patients is the key to obtain the best results from the operation avoiding the side effects and complications here described.

  7. Attributing the increase in Northern Hemisphere hot summers since the late 20th century

    NASA Astrophysics Data System (ADS)

    Kamae, Youichi; Shiogama, Hideo; Watanabe, Masahiro; Kimoto, Masahide

    2014-07-01

    Anomalously high summertime temperatures have occurred with increasing frequency since the late 20th century. It is not clear why hot summers are becoming more frequent despite the recent slowdown in the rise in global surface air temperature. To examine factors affecting the historical variation in the frequency of hot summers over the Northern Hemisphere (NH), we conducted three sets of ensemble simulations with an atmospheric general circulation model. The model accurately reproduced interannual variation and long-term increase in the occurrence of hot summers. Decadal variabilities in the Pacific and Atlantic Oceans accounted for 43 ± 27% of the recent increase over the NH middle latitudes. In addition, direct influence of anthropogenic forcing also contributes to increasing the frequency since the late 20th century. The results suggest that the heat extremes can become more frequent in the coming decade even with the persistent slowdown in the global-mean surface warming.

  8. Vertical profiles of black carbon measured by a micro-aethalometer in summer in the North China Plain

    NASA Astrophysics Data System (ADS)

    Ran, Liang; Deng, Zhaoze; Xu, Xiaobin; Yan, Peng; Lin, Weili; Wang, Ying; Tian, Ping; Wang, Pucai; Pan, Weilin; Lu, Daren

    2016-08-01

    Black carbon (BC) is a dominant absorber in the visible spectrum and a potent factor in climatic effects. Vertical profiles of BC were measured using a micro-aethalometer attached to a tethered balloon during the Vertical Observations of trace Gases and Aerosols (VOGA) field campaign, in summer 2014 at a semirural site in the North China Plain (NCP). The diurnal cycle of BC vertical distributions following the evolution of the mixing layer (ML) was investigated for the first time in the NCP region. Statistical parameters including identified mixing height (Hm) and average BC mass concentrations within the ML (Cm) and in the free troposphere (Cf) were obtained for a selected dataset of 67 vertical profiles. Hm was usually lower than 0.2 km in the early morning and rapidly rose thereafter due to strengthened turbulence. The maximum height of the ML was reached in the late afternoon. The top of a full developed ML exceeded 1 km on sunny days in summer, while it stayed much lower on cloudy days. The sunset triggered the collapse of the ML, and a stable nocturnal boundary layer (NBL) gradually formed. Accordingly, the highest level Cm was found in the early morning and the lowest was found in the afternoon. In the daytime, BC was almost uniformly distributed within the ML and significantly decreased above the ML. During the field campaign, Cm averaged about 5.16 ± 2.49 µg m-3, with a range of 1.12 to 14.49 µg m-3, comparable with observational results in many polluted urban areas such as Milan in Italy and Shanghai in China. As evening approached, BC gradually built up near the surface and exponentially declined with height. In contrast to the large variability found both in Hm and Cm, Cf stayed relatively unaffected through the day. Cf was less than 10 % of the ground level under clean conditions, while it amounted to half of the ground level in some polluted cases. In situ measurements of BC vertical profiles would hopefully have an important implication for

  9. Vertical variations in the influence of the amount effect: South American Summer Monsoon Region

    NASA Astrophysics Data System (ADS)

    Samuels-Crow, K. E.; Galewsky, J.; Worden, J. R.

    2014-12-01

    Recent theoretical studies have shown that convective recycling of atmospheric water vapor gives rise to the isotope "amount effect" in which d values are lower than predicted by simple Rayleigh distillation processes (i.e. (DdD = dDvapor ­- dDRayleigh < 0‰). Several studies have linked isotopes in precipitation [e.g. Vimeux et al., 2009] and atmospheric water vapor [e.g. Samuels-Crow et al., 2014] in the tropical Andes to upwind convection associated with the South American Summer Monsoon (SASM). The vertical structure of this convective influence, however, remains unknown. Understanding the vertical structure of the amount effect over South America is essential for improving theoretical constraints and developing better models of the influence of the SASM on southern hemisphere humidity. Additionally, evaluating the vertical and lateral extent of the SASM's convective influence can provide important constraints for interpreting paleoclimate proxies in the region. We use data from the Tropospheric Emission Spectrometer (TES) to examine the vertical structure of the amount effect associated with the SASM and relate these results to regional convective precipitation and local subcloud equivalent potential temperature. Preliminary results show that DdD is below 0‰ from the boundary layer through the mid-troposphere over tropical South America during austral summer, and meridional averages show that convective precipitation is highest over these areas where DdD < 0‰ extends higher in the atmosphere. We hypothesize that the depth of convection in the monsoon region controls the vertical structure of DdD, which should also be coherently linked to local equivalent potential temperature. References Vimeux et al. (2009), Palaeogeogr Palaeocl, 281(3-4), 229-241, doi:10.1016/j.palaeo.2008.03.054. Samuels-Crow et al. (2014), J Geophys Res-Atmos, doi:10.1002/(ISSN)2169-8996.

  10. Constraints on water vapor vertical distribution at the Phoenix landing site during summer from MGS TES day and night observations

    NASA Astrophysics Data System (ADS)

    Pankine, Alexey A.; Tamppari, Leslie K.

    2015-05-01

    We present a new method to retrieve column abundances and vertical extent of the water vapor from the Mars Global Surveyor (MGS) Thermal Emission Spectrometer (TES) spectra. The new method enables retrievals from the nighttime TES spectra. The retrieval algorithm employs a new model of the vertical distribution of water vapor in the martian atmosphere. In this model water vapor is confined to a layer of finite height in the lower atmosphere. The atmosphere is dry above this 'wet' layer. Within the 'wet' layer the water vapor has a constant mixing ratio below the water ice cloud condensation height and is saturated above that height. The new retrieval method simultaneously fits the daytime and nighttime TES spectra for a given location using a single mixing ratio profile. We apply this new method to the TES spectra collected over the site of the Phoenix spacecraft landing during late northern spring and summer. Retrieved daytime column abundances are ∼1-5 pr-μm higher than in the previous TES retrieval. Nighttime column abundances are lower than the daytime abundances by ∼5-10 pr-μm due to assumed exchange with soil and predicted water ice cloud formation. The height of the 'wet' layer varies with season, reaching ∼18 km around Ls = 80-100° and decreasing to 7-10 km by Ls = 140°. Changes in the vertical extent of vapor are consistent with seasonal changes in the intensity of the turbulent mixing in the lower atmosphere and in the water ice cloud condensation height. Water vapor extends by several kilometers above the top of the boundary layer at ∼4 km, suggesting that vertical transport of vapor is not limited to the boundary layer.

  11. The influence of late summer typhoons and high river discharge on water quality in Hong Kong waters

    NASA Astrophysics Data System (ADS)

    Zhou, Weihua; Yin, Kedong; Harrison, Paul J.; Lee, Joseph H. W.

    2012-10-01

    A typhoon produces a rapid mixing and flushing event and it can be added to the list of other factors such as shallow water depth, spring tidal mixing, the Pearl River discharge, summer upwelling that make Hong Kong waters relatively resistant to eutrophication impacts. Two typhoons passed over Hong Kong waters and provided an opportunity to document the changes in water quality in late summer 2003. Before the typhoon (Aug 19-20) and during a neap tide, a large algal bloom (>10 μg Chl-a L-1) occurred in the stratified southern waters influenced by the Pearl River estuarine waters with high NO3. However, PO4 and SiO4 were drawn down to near limiting concentrations by the large bloom. After the typhoons, Chl-a decreased to 2 μg L-1 due to vertical mixing and advection. The heavy rainfall and increased river discharge quickly re-set the water column to the usual strong summer stratification in only a few days. As a result, high nutrients in the river discharge stimulated another large algal bloom a few days after the next neap tide when tidal mixing was reduced. In the southern waters, the deeper station showed stronger stratification and lower bottom dissolved oxygen (DO) than the shallower station suggesting that the low DO in the bottom water may have come from offshore transport.

  12. Vertical structure of precipitating shallow echoes observed from TRMM during Indian summer monsoon

    NASA Astrophysics Data System (ADS)

    Kumar, Shailendra

    2017-08-01

    The present study explores the properties of precipitating shallow echoes (PSEs) over the tropical areas (30°S-30°N) during Indian summer monsoon season using attenuated corrected radar reflectivity factor (Ze) measured by the Tropical Rainfall Measuring Mission satellite. Radar echoes observed in study are less than the freezing height, so they belong to warm precipitation. Radar echoes with at least 0.75 km wide are considered for finding the shallow echoes climatology. Western Ghats and adjoining ocean (Arabian sea) have the highest PSEs followed by Myanmar and Burma coast, whereas the overall west coast of Latin America consists of the lowest PSEs. Tropical oceanic areas contain fewer PSEs compared to coastal areas. Average vertical profiles show nearly similar Ze characteristics which peaks between 1.5 and 2 km altitude with model value 32-34 dBZ. Slope of Ze is higher for intense PSEs as radar reflectivity decreases more rapidly in intense PSEs.

  13. Analysis of extreme summers and prior late winter/spring conditions in central Europe

    NASA Astrophysics Data System (ADS)

    Träger-Chatterjee, C.; Müller, R. W.; Bendix, J.

    2013-05-01

    Drought and heat waves during summer in mid-latitudes are a serious threat to human health and agriculture and have negative impacts on the infrastructure, such as problems in energy supply. The appearance of such extreme events is expected to increase with the progress of global warming. A better understanding of the development of extremely hot and dry summers and the identification of possible precursors could help improve existing seasonal forecasts in this regard, and could possibly lead to the development of early warning methods. The development of extremely hot and dry summer seasons in central Europe is attributed to a combined effect of the dominance of anticyclonic weather regimes and soil moisture-atmosphere interactions. The atmospheric circulation largely determines the amount of solar irradiation and the amount of precipitation in an area. These two variables are themselves major factors controlling the soil moisture. Thus, solar irradiation and precipitation are used as proxies to analyse extreme sunny and dry late winter/spring and summer seasons for the period 1958-2011 in Germany and adjacent areas. For this purpose, solar irradiation data from the European Center for Medium Range Weather Forecast 40-yr and interim re-analysis dataset, as well as remote sensing data are used. Precipitation data are taken from the Global Precipitation Climatology Project. To analyse the atmospheric circulation geopotential data at 850 hPa are also taken from the European Center for Medium Range Weather Forecast 40-yr and interim re-analysis datasets. For the years in which extreme summers in terms of high solar irradiation and low precipitation are identified, the previous late winter/spring conditions of solar irradiation and precipitation in Germany and adjacent areas are analysed. Results show that if the El Niño-Southern Oscillation (ENSO) is not very intensely developed, extremely high solar irradiation amounts, together with extremely low precipitation

  14. Three Late Summer Cases of Tropical-extratropical Interactions Causing Precipitation In Northwestern Africa

    NASA Astrophysics Data System (ADS)

    Knippertz, P.; Fink, A.; Reiner, A.; Speth, P.

    Several stations in northwestern Africa, in particular in the semi-arid to arid zone south of the Atlas mountains, receive significant contributions to their annual rain- fall amounts from rainy episodes in late summer/early autumn. Three of such cases in September 1988 and 1990 and August/September 1999 are studied with respect to the sources and ways of transport of moisture, anomalies in the upper-level flow, such as position and speed of the Subtropical Jet (STJ), and the associated vertical profiles of divergence and vertical velocity. Beside station reports of precipitation, European Center for Medium-Range Weather Forecast (ECMWF) analysis and re-analysis wind and moisture data and METEOSAT water vapour images are considered. All three cases clearly reveal tropical-extratropical interactions. By the use of trajectory anal- ysis, convective centers over tropical Africa and the adjacent Atlantic Ocean, where moisture is transported from the low-level moist monsoon layer into middle and up- per levels, could be identified as moisture sources for the considered rainy episodes. This moisture is then advected northwards ahead of an upper-level subtropical trough, that extends to the northern edge of the Inter-Tropical Convergence Zone (ITCZ). The ITCZ is at its northernmost position at that time of the year. Most of the transport is found between 700 and 400 hPa and thus mostly above the dry Saharan Planetary Boundary Layer (PBL). Triggered by upper-level divergence ahead of the trough, oro- graphic lifting at the Atlas mountains in the southerly flow and surface heating of areas above the stabilizing trade wind inversion, convective rainfalls occur, preferably close to and downwind of the mountain chain. The maximum convergence is observed be- tween 600 and 500 hPa. Precipitation intensities are mostly small to moderate, since parts of the rain evaporate on the way down through the relatively deep and dry PBL, but in some occasions events of more than 20 mm in 12

  15. C4 plant expansion since the late Miocene and the evolution of Asian summer monsoon

    NASA Astrophysics Data System (ADS)

    Wu, H.; Guo, Z.; Guiot, J.; Yu, Y.; Ge, J.; Zhang, Y.; Peng, S.

    2015-12-01

    A dramatic expansion of C4 plant distribution occurred in the South Asia during the late Miocene and in the East Asia during the Pliocene period, with broad spatial and temporal variations. Although the event is well documented, whether subsequent expansions were caused by a decreased atmospheric CO2 concentration or climate change is a contentious issue. In this study, we used an improved inverse vegetation modeling approach that accounts for the physiological responses of C3 and C4 plants to quantitatively reconstruct the paleoclimate in the Siwalik of South Asia and in the Loess Plateau of East Asia, based on pollen and carbon isotope data. We also studied the sensitivity of the C3 and C4 plants to changes in the climate and the atmospheric CO2 concentration. We suggest that the expansion of the C4 plant distribution since the late Miocene was unlikely caused by reduced CO2 levels alone. The expansion may have been primarily triggered by regional aridification, and seasonal analysis revealed that this climate shift mainly attributed to the summer rainfall decrease. Our findings suggest that this abrupt ecological shift mainly resulted from the weakening of the Asian summer monsoon, which may related to the decrease of SST in the tropic since the late Miocene.

  16. The effect of vertical and horizontal symmetry on memory for tactile patterns in late blind individuals.

    PubMed

    Cattaneo, Zaira; Vecchi, Tomaso; Fantino, Micaela; Herbert, Andrew M; Merabet, Lotfi B

    2013-02-01

    Visual stimuli that exhibit vertical symmetry are easier to remember than stimuli symmetric along other axes, an advantage that extends to the haptic modality as well. Critically, the vertical symmetry memory advantage has not been found in early blind individuals, despite their overall superior memory, as compared with sighted individuals, and the presence of an overall advantage for identifying symmetric over asymmetric patterns. The absence of the vertical axis memory advantage in the early blind may depend on their total lack of visual experience or on the effect of prolonged visual deprivation. To disentangle this issue, in this study, we measured the ability of late blind individuals to remember tactile spatial patterns that were either vertically or horizontally symmetric or asymmetric. Late blind participants showed better memory performance for symmetric patterns. An additional advantage for the vertical axis of symmetry over the horizontal one was reported, but only for patterns presented in the frontal plane. In the horizontal plane, no difference was observed between vertical and horizontal symmetric patterns, due to the latter being recalled particularly well. These results are discussed in terms of the influence of the spatial reference frame adopted during exploration. Overall, our data suggest that prior visual experience is sufficient to drive the vertical symmetry memory advantage, at least when an external reference frame based on geocentric cues (i.e., gravity) is adopted.

  17. Temporal variation and stoichiometric ratios of organic matter remineralization in bottom waters of the northern Gulf of Mexico during late spring and summer

    NASA Astrophysics Data System (ADS)

    Xue, Jianhong; Cai, Wei-Jun; Hu, Xinping; Huang, Wei-Jen; Lohrenz, Steven E.; Gundersen, Kjell

    2015-12-01

    An improved extended optimum multiparameter (eOMP) analysis was applied to hydrographic (temperature and salinity), and water chemistry data, including dissolved oxygen (O2), nutrients (nitrate plus nitrite, phosphate, and silicate), dissolved inorganic carbon (DIC), and total alkalinity (TAlk) data collected during late spring and summer from 2006 to 2012 in bottom waters off the Louisiana coast, to explore the dynamics and stoichiometry of DIC production during the development and maintenance of summer hypoxia. Our analysis demonstrated that DIC in bottom water was relatively low from April to June, but increased significantly in July, peaked in August, and dropped slightly in September. Furthermore, DIC production resulted from both aerobic organic carbon (OC) respiration and denitrification, as well as substantial loss due to vertical mixing with surface water. The average summer gross OC respiration rate was estimated to be 0.19 g C m-2 d-1, with the highest values occurring in late summer when hypoxic conditions dominated. We also found that Corg/N/P/-O2 remineralization ratios for aerobic respiration were generally consistent with the classic Redfield ratio (106/16/1/138) except individual C/N and C/P ratios were slightly lower, indicating that marine OC was the major source of the DIC production in the bottom water. This study quantified the role of temporal bottom-water microbial respiration to seasonal DIC dynamics and provided a means for studying the stoichiometry of biogeochemical processes in coastal waters.

  18. The impact of warming climate on late summer snow cover in northwestern Finland

    NASA Astrophysics Data System (ADS)

    Kivinen, S.; Kaarlejärvi, E.; Jylhä, K.; Räisänen, J.

    2012-04-01

    Snowbeds and snow patches are characteristic features of arctic and alpine regions and are classified as endangered habitats due to the warming climate. We studied interannual variation of late summer snow cover and the factors affecting it in sub-arctic Enontekiö Lapland, northwestern Finland in years 2000, 2004, 2006, and 2009. Snow cover at 30 m resolution was derived from Landsat TM and ETM+ images obtained between 27 July and 4 August using a normalized difference snow index (NDSI). A generalized linear model (GLM) was constructed for the number (0 - 4) of snow occurrence years in 1-km grid squares. Explanatory variables in the model were elevation, terrain ruggedness, insolation and aspect. Variation in climatic conditions in the study region was examined using temperature and precipitation data from 1995 to 2009 (Finnish Meteorological Institute) and climate scenarios derived from the ENSEMBLES and PRUDENCE simulations extending to the period of 2070-2099. Late summer snow covered 23.0 km2 in 2000, 2.7 km2 in 2004, 1.5 km2 in 2006, and 5.0 km2 in 2009 of the 3176.5 km2 study area (mean altitude 727 m, maximum altitude 1310 m). The decline of snow cover was most prominent below 900 meters and on southern and western slopes. In year 2000, approximately a half of the snow cover was found above 900 meters (where 7% of the total study area is located) compared to circa 75% in 2004 and 2006, and 62% in 2009. Analyses at the 1-km resolution showed that in 19 % of the study squares there was late summer snow at least in one of the four years. Elevation and terrain ruggedness were the strongest explanatory variables for the number of snow occurrence year in a univariate GLM model. The GLM model including all variables explained 73% of the variation in the number of snow occurrence years. The interannual variation in late summer snow cover reflects the climatic variation in the study region. The mean annual temperature increased on average by 0.16°C per year during

  19. Has the prediction of the South China Sea summer monsoon improved since the late 1970s?

    NASA Astrophysics Data System (ADS)

    Fan, Yi; Fan, Ke; Tian, Baoqiang

    2016-12-01

    Based on the evaluation of state-of-the-art coupled ocean-atmosphere general circulation models (CGCMs) from the ENSEMBLES (Ensemble-based Predictions of Climate Changes and Their Impacts) and DEMETER (Development of a European Multimodel Ensemble System for Seasonal to Interannual Prediction) projects, it is found that the prediction of the South China Sea summer monsoon (SCSSM) has improved since the late 1970s. These CGCMs show better skills in prediction of the atmospheric circulation and precipitation within the SCSSM domain during 1979-2005 than that during 1960-1978. Possible reasons for this improvement are investigated. First, the relationship between the SSTs over the tropical Pacific, North Pacific and tropical Indian Ocean, and SCSSM has intensified since the late 1970s. Meanwhile, the SCSSM-related SSTs, with their larger amplitude of interannual variability, have been better predicted. Moreover, the larger amplitude of the interannual variability of the SCSSM and improved initializations for CGCMs after the late 1970s contribute to the better prediction of the SCSSM. In addition, considering that the CGCMs have certain limitations in SCSSM rainfall prediction, we applied the year-to-year increment approach to these CGCMs from the DEMETER and ENSEMBLES projects to improve the prediction of SCSSM rainfall before and after the late 1970s.

  20. Evidence for ice-free summers in the late Miocene central Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Stein, Ruediger; Fahl, Kirsten; Schreck, Michael; Knorr, Gregor; Niessen, Frank; Forwick, Matthias; Gebhardt, Catalina; Jensen, Laura; Kaminski, Michael; Kopf, Achim; Matthiessen, Jens; Jokat, Wilfried; Lohmann, Gerrit

    2016-04-01

    Although the permanently to seasonally ice-covered Arctic Ocean is a unique and sensitive component in the Earth's climate system, the knowledge of its long-term climate history remains very limited due to the restricted number of pre-Quaternary sedimentary records. During Polarstern Expedition PS87/2014, we discovered multiple submarine landslides along Lomonosov Ridge. Removal of younger sediments from steep headwalls has led to exhumation of Miocene sediments close to the seafloor. Here we document the presence of IP25 as a proxy for spring sea-ice cover and alkenone-based summer sea-surface temperatures >4 °C that support a seasonal sea-ice cover with an ice-free summer season being predominant during the late Miocene in the central Arctic Ocean. A comparison of our proxy data with Miocene climate simulations seems to favour either relatively high late Miocene atmospheric CO2 concentrations and/or a weak sensitivity of the model to simulate the magnitude of high-latitude warming in a warmer than modern climate.

  1. Evidence for ice-free summers in the late Miocene central Arctic Ocean.

    PubMed

    Stein, Ruediger; Fahl, Kirsten; Schreck, Michael; Knorr, Gregor; Niessen, Frank; Forwick, Matthias; Gebhardt, Catalina; Jensen, Laura; Kaminski, Michael; Kopf, Achim; Matthiessen, Jens; Jokat, Wilfried; Lohmann, Gerrit

    2016-04-04

    Although the permanently to seasonally ice-covered Arctic Ocean is a unique and sensitive component in the Earth's climate system, the knowledge of its long-term climate history remains very limited due to the restricted number of pre-Quaternary sedimentary records. During Polarstern Expedition PS87/2014, we discovered multiple submarine landslides along Lomonosov Ridge. Removal of younger sediments from steep headwalls has led to exhumation of Miocene sediments close to the seafloor. Here we document the presence of IP25 as a proxy for spring sea-ice cover and alkenone-based summer sea-surface temperatures >4 °C that support a seasonal sea-ice cover with an ice-free summer season being predominant during the late Miocene in the central Arctic Ocean. A comparison of our proxy data with Miocene climate simulations seems to favour either relatively high late Miocene atmospheric CO2 concentrations and/or a weak sensitivity of the model to simulate the magnitude of high-latitude warming in a warmer than modern climate.

  2. Late summer net community production in the central Arctic Ocean using multiple approaches

    NASA Astrophysics Data System (ADS)

    Ulfsbo, Adam; Cassar, Nicolas; Korhonen, Meri; van Heuven, Steven; Hoppema, Mario; Kattner, Gerhard; Anderson, Leif G.

    2014-10-01

    Large-scale patterns of net community production (NCP) were estimated during the late summer cruise ARK-XXVI/3 (TransArc, August/September 2011) to the central Arctic Ocean. Several approaches were used based on the following: (i) continuous measurements of surface water oxygen to argon ratios (O2/Ar), (ii) underway measurements of surface partial pressure of carbon dioxide (pCO2), (iii) discrete samples of dissolved inorganic carbon, and (iv) dissolved inorganic nitrogen and phosphate. The NCP estimates agreed well within the uncertainties associated with each approach. The highest late summer NCP (up to 6 mol C m-2) was observed in the marginal sea ice zone region. Low values (<1 mol C m-2) were found in the sea ice-covered deep basins with a strong spatial variability. Lowest values were found in the Amundsen Basin and moderate values in the Nansen and Makarov Basins with slightly higher estimates over the Mendeleev Ridge. Our findings support a coupling of NCP to sea ice coverage and nutrient supply and thus stress a potential change in spatial and temporal distribution of NCP in a future Arctic Ocean. To follow the evolution of NCP in space and time, it is suggested to apply one or several of these approaches in shipboard investigations with a time interval of 3 to 5 years.

  3. Evidence for ice-free summers in the late Miocene central Arctic Ocean

    PubMed Central

    Stein, Ruediger; Fahl, Kirsten; Schreck, Michael; Knorr, Gregor; Niessen, Frank; Forwick, Matthias; Gebhardt, Catalina; Jensen, Laura; Kaminski, Michael; Kopf, Achim; Matthiessen, Jens; Jokat, Wilfried; Lohmann, Gerrit

    2016-01-01

    Although the permanently to seasonally ice-covered Arctic Ocean is a unique and sensitive component in the Earth's climate system, the knowledge of its long-term climate history remains very limited due to the restricted number of pre-Quaternary sedimentary records. During Polarstern Expedition PS87/2014, we discovered multiple submarine landslides along Lomonosov Ridge. Removal of younger sediments from steep headwalls has led to exhumation of Miocene sediments close to the seafloor. Here we document the presence of IP25 as a proxy for spring sea-ice cover and alkenone-based summer sea-surface temperatures >4 °C that support a seasonal sea-ice cover with an ice-free summer season being predominant during the late Miocene in the central Arctic Ocean. A comparison of our proxy data with Miocene climate simulations seems to favour either relatively high late Miocene atmospheric CO2 concentrations and/or a weak sensitivity of the model to simulate the magnitude of high-latitude warming in a warmer than modern climate. PMID:27041737

  4. Ocean forcing to the interdecadal change of summer rainfall in China around the late-1990s

    NASA Astrophysics Data System (ADS)

    Liu, Y.

    2016-12-01

    Previous studies indicated an interdecadal change in the summer rainfall over China around the late-1990s, and accompanying this interdecadal change, the summer rainfall increased over Southern China and decreased over Northern China, featuring an anomalous "south-flood-north-drought" pattern. The present work, using the observational and numerical studies, investigated the global atmospheric circulation changes and the oceanic role that related to this intedecadal change. Results showed that this interdecadal change had a global climate change background, corresponding to the interdecadal change, the summer atmospheric circulation experienced notable changes with symmetric features in the northern and southern hemisphere. And the global sea surface temperature (SST) revealed remarkable changes as well, having SST warming over Indian Ocean and Atlantic Ocean, and La Niña-like/PDO-like SST anomalies (SSTA) over Pacific Ocean. These features suggested this interdecadal change may be a response to the tropical Ocean SST forcing, especially the tropical Pacific Ocean SST changes. The numerical results using an AGCM forced by the tropical SSTA, especially the tropical Pacific Ocean SSTA, resembled the observational results, confirming the Ocean's role in the intedecadal change. The possible mechanism whereby the tropical SSTA triggering the interdecadal change was explored as well. There may be two ways: (1) Anomalous convection over tropical and subtropical areas induced the tropical SSTA excited baroclinic Rossby waves which propagated polarward causing the extratropical circulation changes; (2) Owing to the tropical SSTA forcing, the subtropical westerly jet in the northern hemisphere weakened and shifted polarward. Changes in the subtropical jet influenced the stationary and transient eddy momentum flux which affected the eddy-induced mean merdional circulation, inducing ascending motion over subtropics and descending motion in the middle latitude. Through above

  5. The horizontal and vertical structure of noctilucent clouds: Small scale dynamics in the summer mesopause region

    NASA Astrophysics Data System (ADS)

    Baumgarten, Gerd; Fiedler, Jens; Lübken, Franz-Josef; Stober, Gunter

    2017-04-01

    Noctilucent clouds (NLC) are thin ice clouds forming in the summer mesopause region at high latitudes. Their highly structured appearance has attracted scientific interest since more than 130 years as they are found at an altitude of about 83 km where the atmosphere pressure is about 5 orders of magnitude lower than at the earth surface. The structured appearance of NLC has been linked to atmospheric waves and their transition to turbulence, these clouds are therefore used as tracers for dynamics in a height region that is difficult to study otherwise. We use the ALOMAR RMR-lidar, located in Northern Norway at 69°N, that is able to measure NLC with sub-second resolution. Although the ice particles in NLC are only a few tenths of nanometer their size can be measured when observing the clouds at different colors. In combination with ground and space based cameras or radars the horizontal structure is investigated on scales from meters to hundreds of kilometers. We present recent results indicating that the rich structures of NLC - that are even visible to the naked eye - are caused by the peculiar nature of the clouds. Lidar observations give evidence that at times the brightest part of NLC is confined to 100 m vertical extend, giving a superior resolution to small scale atmosphere dynamics compared to, e.g., airglow layers in the Mesosphere lower Thermosphere region.

  6. Thermal structure and dust loading of the Martian atmosphere during late southern summer - Mariner 9 revisited

    NASA Astrophysics Data System (ADS)

    Santee, M.; Crisp, D.

    1993-02-01

    Thermal emission spectra recorded by the Mariner 9 IR interferometer spectrometer (IRIS) are used to investigate the temperature structure and dust loading of the Martian atmosphere. The analysis is restricted to a subset of the IRIS data consisting of approximately 2400 spectra in a 12-day period extending from LS of 343 to 348 deg, corresponding to late southern summer on Mars. The largest column-integrated 9-micron dust optical depths (about 0.4) occur over the equatorial regions. The highest atmospheric temperatures (greater than 260 K) are found at low altitudes near the subsolar latitude (about 6 deg S), while the coldest temperatures (less than 150 K) are found at levels near 1.0 mbar over the winter pole. The existence of a net zonally averaged meridional circulation with rising motion at low latitudes, poleward flow at altitudes above 40 km, and subsidence over the poles is suggested.

  7. Black-footed ferret areas of activity during late summer and fall at Meeteetse, Wyoming

    USGS Publications Warehouse

    Fagerstone, K.A.; Biggins, D.E.

    2011-01-01

    Radiotelemetry was used during 1983 and 1984 to collect information on short-term areas of activity for black-footed ferrets (Mustela nigripes) near Meeteetse, Wyoming. This population ultimately provided ferrets for the captive-breeding program that bred and released offspring into the wild since 1991. We fitted 5 adult ferrets and 13 juveniles with radiotransmitters and followed their movements during late summer and fall. Adult males had 7-day areas of activity that were >6 times as large as those of adult females. Activity areas of adult males varied little in coverage or location on a weekly basis, but females sequentially shifted their areas. Unlike juvenile females, juvenile males tended to leave their natal colonies. ?? 2011 American Society of Mammalogists.

  8. Thermal structure and dust loading of the Martian atmosphere during late southern summer - Mariner 9 revisited

    NASA Technical Reports Server (NTRS)

    Santee, Michelle; Crisp, David

    1993-01-01

    Thermal emission spectra recorded by the Mariner 9 IR interferometer spectrometer (IRIS) are used to investigate the temperature structure and dust loading of the Martian atmosphere. The analysis is restricted to a subset of the IRIS data consisting of approximately 2400 spectra in a 12-day period extending from LS of 343 to 348 deg, corresponding to late southern summer on Mars. The largest column-integrated 9-micron dust optical depths (about 0.4) occur over the equatorial regions. The highest atmospheric temperatures (greater than 260 K) are found at low altitudes near the subsolar latitude (about 6 deg S), while the coldest temperatures (less than 150 K) are found at levels near 1.0 mbar over the winter pole. The existence of a net zonally averaged meridional circulation with rising motion at low latitudes, poleward flow at altitudes above 40 km, and subsidence over the poles is suggested.

  9. Modeling Late-Summer Distribution of Golden Eagles (Aquila chrysaetos) in the Western United States

    PubMed Central

    Gardner, Grant

    2016-01-01

    Increasing development across the western United States (USA) elevates concerns about effects on wildlife resources; the golden eagle (Aquila chrysaetos) is of special concern in this regard. Knowledge of golden eagle abundance and distribution across the western USA must be improved to help identify and conserve areas of major importance to the species. We used distance sampling and visual mark-recapture procedures to estimate golden eagle abundance from aerial line-transect surveys conducted across four Bird Conservation Regions in the western USA between 15 August and 15 September in 2006–2010, 2012, and 2013. To assess golden eagle-habitat relationships at this scale, we modeled counts of golden eagles seen during surveys in 2006–2010, adjusted for probability of detection, and used land cover and other environmental factors as predictor variables within 20-km2 sampling units randomly selected from survey transects. We found evidence of positive relationships between intensity of use by golden eagles and elevation, solar radiation, and mean wind speed, and of negative relationships with the proportion of landscape classified as forest or as developed. The model accurately predicted habitat use observed during surveys conducted in 2012 and 2013. We used the model to construct a map predicting intensity of use by golden eagles during late summer across our ~2 million-km2 study area. The map can be used to help prioritize landscapes for conservation efforts, identify areas where mitigation efforts may be most effective, and identify regions for additional research and monitoring. In addition, our map can be used to develop region-specific (e.g., state-level) density estimates based on the latest information on golden eagle abundance from a late-summer survey and aid designation of geographic management units for the species. PMID:27556735

  10. Modeling Late-Summer Distribution of Golden Eagles (Aquila chrysaetos) in the Western United States.

    PubMed

    Nielson, Ryan M; Murphy, Robert K; Millsap, Brian A; Howe, William H; Gardner, Grant

    2016-01-01

    Increasing development across the western United States (USA) elevates concerns about effects on wildlife resources; the golden eagle (Aquila chrysaetos) is of special concern in this regard. Knowledge of golden eagle abundance and distribution across the western USA must be improved to help identify and conserve areas of major importance to the species. We used distance sampling and visual mark-recapture procedures to estimate golden eagle abundance from aerial line-transect surveys conducted across four Bird Conservation Regions in the western USA between 15 August and 15 September in 2006-2010, 2012, and 2013. To assess golden eagle-habitat relationships at this scale, we modeled counts of golden eagles seen during surveys in 2006-2010, adjusted for probability of detection, and used land cover and other environmental factors as predictor variables within 20-km2 sampling units randomly selected from survey transects. We found evidence of positive relationships between intensity of use by golden eagles and elevation, solar radiation, and mean wind speed, and of negative relationships with the proportion of landscape classified as forest or as developed. The model accurately predicted habitat use observed during surveys conducted in 2012 and 2013. We used the model to construct a map predicting intensity of use by golden eagles during late summer across our ~2 million-km2 study area. The map can be used to help prioritize landscapes for conservation efforts, identify areas where mitigation efforts may be most effective, and identify regions for additional research and monitoring. In addition, our map can be used to develop region-specific (e.g., state-level) density estimates based on the latest information on golden eagle abundance from a late-summer survey and aid designation of geographic management units for the species.

  11. Late Holocene Indian summer monsoon variations recorded at Lake Erhai, Southwestern China

    NASA Astrophysics Data System (ADS)

    Xu, Hai; Zhou, Xinying; Lan, Jianghu; Liu, Bin; Sheng, Enguo; Yu, Keke; Cheng, Peng; Wu, Feng; Hong, Bin; Yeager, Kevin M.; Xu, Sheng

    2015-03-01

    In this study we report changes in Indian summer monsoon (ISM) intensity during the past ~ 3500 yr inferred from proxy indices at Lake Erhai, southwestern China. Both the pollen concentrations and other proxy indices, including sediment grain size, total organic carbon contents (TOC), and elemental contents (e.g., Fe, Al), clearly indicate a long term decreasing trend in ISM intensity over the late Holocene. During the period from approximately AD 750 to AD 1200, pollen concentrations of conifer and broadleaf trees, and herbs reached the lowest levels over the past ~ 3500 yr; while the pollen percentages of both herbs and broadleaf trees increased, suggesting a significant medieval drought. The grain size, TOC, and elemental contents also support an arid climate during the medieval period. The Little Ice Age (LIA) at Lake Erhai was characterized as cold and wet. The medieval and LIA climatic patterns at Lake Erhai were similar to those over most of the ISM areas, but anti-phase with those over East Asian summer monsoon (EASM) areas. We suspect that sea surface temperature variations in the Indo-Pacific oceans and the related land-sea thermal contrasts may be responsible for such hydroclimatic differences between EASM and ISM areas.

  12. Pre-AP® Science Vertical Teams Summer Institute Evaluation Summary: A One-Year Follow-Up. Research Note 2012-1

    ERIC Educational Resources Information Center

    Laitusis, Vytas; Barry, Carol

    2012-01-01

    This study evaluated the effect of a pilot Pre-AP® Science Vertical Team Summer Institute on teacher practices and perceptions of the program. The overarching goals of the Vertical Teams Institute were focused on the tools needed to build or strengthen an AP® Vertical Team and to align science curriculum across grade levels. The evaluation also…

  13. Horizontal Divergence and Vertical Velocity Adjacent to the Pyrenees Measured During the Boundary Layer Late Afternoon & Sunset Turbulence (BLLAST) Experiment

    NASA Astrophysics Data System (ADS)

    Faloona, I. C.; Lothon, M.

    2014-12-01

    Because of the dominant influence of surface solar heating on atmospheric boundary layer (ABL) flows, the character and even underlying theories of turbulence vary diurnally over the continents. While great strides have been made in our understanding of the stable boundary layers that prevail overnight, the period of transition from a convective daytime to a stable nighttime ABL remains a very challenging problem in no small part because of its inherently non-stationary nature and because both of the main forcings, wind stress and surface heat flux, tend to flag at this time of day. These underexplored topics motivated the Boundary Layer Late Afternoon and Sunset Turbulence (BLLAST) field experiment held in the summer of 2011 at the CNRS Laboratorie d'Aerologie in Campistrous, France. On three of the twelve intensive observational days of the experiment, three rawinsondes were launched simultaneously approximately 3 km apart throughout the afternoon transition in order to directly measure mesoscale horizontal divergence in the ABL and lower free troposphere. Using the assumption of incompressibility, the observed divergence is integrated and a vertical profile of mean vertical wind is derived for the lower troposphere. Although the magnitude of the inferred vertical winds are much larger than expected (of order 0.1 ms-1), the measurements do indicate a clear trend in afternoon subsidence giving way to evening uplift at the site, which is within ~10 km of the Pyrenees' foothills. The observed transition from low-level divergence to convergence was accompanied by a deep surface pressure minimum that fluctuated by nearly 300 Pa diurnally, and we propose that it is likely related to the reversal of the plain-mountain circulation across the region. The impact of such behavior on boundary layer growth and entrainment during the afternoon hours are discussed along with evidence of similar behavior observed elsewhere in mountainous terrain.

  14. Frequency spectra and vertical profiles of wind fluctuations in the summer Antarctic mesosphere revealed by MST radar observations

    NASA Astrophysics Data System (ADS)

    Sato, Kaoru; Kohma, Masashi; Tsutsumi, Masaki; Sato, Toru

    2017-01-01

    Continuous observations of polar mesosphere summer echoes at heights from 81-93 km were performed using the first Mesosphere-Stratosphere-Troposphere/Incoherent Scatter radar in the Antarctic over the three summer periods of 2013/2014, 2014/2015, and 2015/2016. Power spectra of horizontal and vertical wind fluctuations, and momentum flux spectra in a wide-frequency range from (8 min)-1 to (20 days) -1 were first estimated for the Antarctic summer mesosphere. The horizontal (vertical) wind power spectra obey a power law with an exponent of approximately -2 (-1) at frequencies higher than the inertial frequency of (13 h)-1 and have isolated peaks at about 1 day and a half day. In addition, an isolated peak of a quasi-2 day period is observed in the horizontal wind spectra but is absent from the vertical wind spectra, which is consistent with the characteristics of a normal-mode Rossby-gravity wave. Zonal (meridional) momentum flux spectra are mainly positive (negative), and large fluxes are observed in a relatively low-frequency range from (1 day)-1 to (1 h)-1. A case study was performed to investigate vertical profiles of momentum fluxes associated with gravity waves and time mean winds on and around 3 January 2015 when a minor stratospheric warming occurred in the Northern Hemisphere. A significant momentum flux convergence corresponding to an eastward acceleration of 200 m s-1 d-1 was observed before the warming and became stronger after the warming when mean zonal wind weakened. The strong wave forcing roughly accorded with the Coriolis force of mean meridional winds.

  15. Late Cenozoic genus Fupingopollenites development and its implications for the Asian summer monsoon (ASM) evolution

    NASA Astrophysics Data System (ADS)

    Miao, Y.; Song, C.; Fang, X.; Meng, Q.; Zhang, P.; Wu, F.; Yan, X.

    2015-12-01

    An extinct palynomorph, Fupingopollenites, was used as the basis for a discussion of the late Cenozoic Asian summer monsoon (ASM) evolution and its possible driving forces. Based on the spatial and temporal variations in its percentages across Inner and East Asia, we found that Fupingopollenites mainly occurred in East Asia, with boundaries to the NE of ca. 42°N, 135°E and NW of ca. 36°N, 103°E during the Early Miocene (ca. 23-17 Ma). This region enlarged westwards, reaching the eastern Qaidam Basin (ca. 36°N, 97.5°E) during the Middle Miocene (ca. 17-11 Ma), before noticeably retreating to a region bounded to the NW at ca. 33°N, 105°E during ca. 11-5.3 Ma. The region then shrank further in the Pliocene, with the NE boundary shrinking southwards to about 35°N, 120°E; the area then almost disappeared during the Pleistocene (2.6-0 Ma). The flourishing and subsequent extinction of Fupingopollenites is indicative of a narrow ecological amplitude with a critical dependence on habitat humidity and temperature (most likely mean annual precipitation (MAP) >1000 mm and mean annual temperature (MAT) >10°C). Therefore, the Fupingopollenites geographic distribution can indicate the humid ASM evolution during the late Cenozoic, revealing that the strongest ASM period occurred during the Middle Miocene Climate Optimum (MMCO, ~17-14 Ma), after which the ASM weakened coincident with global cooling. We argue that the global cooling played a critical role in the ASM evolution, while the Tibetan Plateau uplifts made a relatively small contribution. This result was supported by a Miocene pollen record at the Qaidam Basin, inner Asia and the contemporaneously compiled pollen records across the Eurasia.

  16. Late cenozoic vertical movements of non-volcanic islands in the Banda Arc area

    NASA Astrophysics Data System (ADS)

    De Smet, M. E. M.; Fortuin, A. R.; Tjokrosapoetro, S.; Van Hinte, J. E.

    During onshore campaigns of the Snellius-II Expedition late Cenozoic sections were recorded and systematically sampled on the non-volcanic outer Banda Arc Islands of Timor, Buton, Buru, Seram and Kai. Microfaunal studies provided age and palaeobathymetric data to construct geohistory diagrams. Geohistory analysis of field and laboratory data allows to calculate rates of vertical movements of the island basements. The vertical movements were intermittent and differed widely from place to place in the arc; short periods of uplift alternated with longer periods of tectonic rest or subsidence and lateral variations in timing and magnitude seem to be more the rule than the exception. Movements affected larger segments of the arc at about the same time, especially since the late Pliocene, when widespread vertical movements started, which led to the present configuration of the arc. Rates of uplift or subsidence differed within each segment. On an intermediate scale, deformation has the character of tilting or doming of whole islands or parts of islands. On a local scale, various types of deformation occur. Calculated duration of uplift pulses is in the order of a million years where less than 50 cm·ka -1 of vertical movements are involved. Sections, however, with a high time stratigraphic resolutions show pulses of uplift with a duration of only some hundreds of thousands of years and rates of more than 500 cm·ka -1. The duration of such pulses therefore is comparable to that of eustatic third order sea level changes. But because their amplitude is an order of magnitude larger, this implies that in tectonically active areas eustatic signals, preserved in the sedimentary record, will be overprinted by tectonics, i.e. will be difficult to disentangle from the tectonic signal.

  17. Wetting and greening Tibetan Plateau in early summer since the late 1970s due to advanced Asian summer monsoon onset

    NASA Astrophysics Data System (ADS)

    Zhang, Wenxia; Zhou, Tianjun; Zhang, Lixia

    2016-04-01

    Known as the "the world water tower", the Tibetan Plateau (TP) is the origin of the ten largest rivers in Asia, breeding more than 1.4 billion people, and exerts substantial influences on water resources, agriculture, and ecosystems in downstream countries. This region is one of the most susceptible areas around the world to changing climate due to the high elevation. Observed evidence have shown significant climate changes over the TP, including surface air warming and moistening, glaciers shrinking, winds stilling, solar dimming, and atmospheric heat source weakening. However, as an essential part of the hydrological cycle, precipitation changes on the TP remain an ambiguous picture. Changes in precipitation vary largely with different seasons, time periods and climate zones considered. This study shows a robust increase in precipitation amount over the TP in May, when the rainy season starts, over the period 1979-2014 (31% relative to the climatology). The wetting trend is spatially consistent over the south-eastern TP, to which both precipitation frequency and intensity contribute. Circulation trends show that the wetting TP in May is resulted from the advanced onset of Asian summer monsoon, which onsets 1~2 pentads earlier since 1979. It intensified water vapor transport from the Bay of Bengal (BOB) to south of the TP in May and local anomalous convection. This relationship is further validated by the significant correlation coefficient (0.47) between the onset dates of Asian summer monsoon (particularly the BOB summer monsoon, 0.68) and precipitation over the south-eastern TP in May. The wetting TP in May has further exerted profound impacts on the hydrological cycle and ecosystem, such as moistening the soil and animating vegetation activities throughout early summer. Both decadal variations of soil moisture (from May to June) and Normalized Difference Vegetation Index (NDVI) (from May to July) coincide well with that of precipitation over the south

  18. On the Vertical Distribution of Mean Vertical Velocities in the Convective Regions during Wet and Dry Spells of Indian Summer Monsoon over Gadanki

    NASA Astrophysics Data System (ADS)

    Uma, K. N.; Kishore Kumar, K.; Shankar Das, Siddarth; Satyanarayana, T. M.; Rao, T. N.

    Indian MST radar observations of vertical distribution of mean vertical velocities (w) in con-vective regions during the wet and dry spells of Indian summer monsoon over a tropical station Gadanki (13.50N, 79.20 E) are discussed. The composite w profile for wet spell consistently shows a single peak at 13 km whereas during dry spell it shows two peaks one at 5 and another at 11-13 km. The characteristics of this altitudinal distribution in w are discussed in terms of background wind and thermal structure during both these spells of monsoon. Background w obtained from NCEP/NCAR reanalysis shows subsidence throughout the depth of the tro-posphere during the dry spell of monsoon over Gadanki. The analysis of background wind and thermal structure clearly revealed the enhanced wind shear and temperature inversion in the middle troposphere and are found to be the main reasons for the observed double peak w structure during the dry spell of monsoon. The present analysis for the first time brought out the mechanisms responsible for a distinct vertical distribution in w during wet and dry spells of monsoon over Gadanki.

  19. Late summer and fall wave climate in the Beaufort and Chukchi Seas, 2000-2014

    NASA Astrophysics Data System (ADS)

    Fan, Y.; Rogers, W.; Thomson, J.; Stopa, J.

    2016-02-01

    Jim Thomson, Applied Physics Laboratory, University of Washington, Seattle, WA According to IPCC, "warming in the Arctic, as indicated by daily maximum and minimum temperatures, has been as great as in any other part of the world." Some regions within the Arctic have warmed even more rapidly, with Alaska and western Canada's temperature rising by 3 to 4 °C (5.40 to 7.20 °F). Arctic ice is getting thinner, melting and rupturing. The polar ice cap as a whole is shrinking. Images from NASA satellites show that the area of permanent ice cover is contracting at a rate of 9 percent each decade. If this trend continues, summers in the Arctic could become ice-free by the end of the century. Arctic storms thus have the potential to create large waves in the region. Ocean waves can also penetrate remarkable distances into ice fields and impact sea-ice thermodynamics by breaking up ice floes and accelerating ice melting during the summer (Asplin et al 2012); or influencing sea-ice growth and hence the morphology of the mature ice sheet during the winter (Lange et al 1989). Waves breaking on the shore could also affect the coastlines, where melting permafrost is already making shores more vulnerable to erosion. Preliminary wave model results from four selected years suggests that the sea state of the Beaufort and Chukchi seas is controlled by the wind forcing and the amount of ice-free water available to generate surface waves. In particular, larger waves are more common in years with low or late sea ice cover. Trends in amount of wave energy impinging on the ice edge, however, are inconclusive. To better understand the potential effect of surface wave on the advance/retreat of ice edges and the coastlines. 15 years (2000 to 2014) of surface wave simulations in the Arctic Ocean using WAVEWATCH III will be conducted. Wind and ice forcing are obtained from the ERA-interim global reanalysis produced by the European Centre for Medium-Range Weather Forecasts (ECMWF). Wave energy

  20. Multi-Summer Climatology of Cumuli at SGP site: Vertical Structure

    SciTech Connect

    Kassianov, Evgueni I.; Berg, Larry K.

    2011-10-01

    We perform a case study for estimating the impact of the vertical distribution of cloud fraction on the normalized cloud radiative forcing (CRF) using a decade-long (2000-2009) high resolution dataset of cloud macrophysical and radiative properties. This dataset is developed for fair-weather cumuli (FWC) observed at the U.S. Department of Energy's Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site. The design of the case study reduces effects associated with non-cloud factors, such as the diurnal changes of aerosol loading and solar zenith angle. The results of the case study suggest that the impact of the vertical cloud structure can be substantial. Therefore, taking into account the vertical distribution of clouds would be beneficial for more comprehensive parameterizations aimed to portray the complex interactions between clouds and radiation more accurately

  1. Influence of Amur River discharge on phytoplankton photophysiology in the Sea of Okhotsk during late summer

    NASA Astrophysics Data System (ADS)

    Isada, Tomonori; Iida, Takahiro; Liu, Hongbin; Saitoh, Sei-Ichi; Nishioka, Jun; Nakatsuka, Takeshi; Suzuki, Koji

    2013-04-01

    We investigated the photosynthetic parameters of phytoplankton in the Sea of Okhotsk during the late summer of 2006 to characterize their spatiotemporal variability and to test the hypothesis that discharge from the Amur River could influence the algal photophysiology. The highest maximum quantum yield of carbon fixation in photosynthesis (Φcmax; 0.098 mol C mol photons-1) was found near the Amur River mouth, where nitrate was depleted. However, none of the photosynthetic parameters, including primary productivity (PP) at the surface, were correlated with temperature, daily photosynthetically available radiation (PAR), or ambient nutrient concentrations. Variations in Φcmax depended on the variations in not only the mean chlorophyll a specific absorption coefficient of phytoplankton (ā*ph) but also the slope index of the absorption coefficient of phytoplankton (aph slope), an indicator for the ratio of nonphotosynthetic carotenoids to photosynthetic carotenoids. These results indicated that the phytoplankton assemblages acclimated to the ambient light conditions by regulating their cellular pigments. Additionally, ā*ph and euphotic depth (Zeu) were significantly correlated with salinity, suggesting that photoacclimation of the phytoplankton assemblages observed in this study could be induced by discharge of Amur River. Because spatiotemporal variations in PP were concomitant with Φcmax, ā*ph, and the chlorophyll a concentration, PP models based on inherent optical property (IOP) were suitable for estimating PP in the Sea of Okhotsk. This study is the first to investigate the factors controlling phytoplankton photophysiology in the Sea of Okhotsk, one of the highest primary production areas in the world.

  2. Late-Summer Tundra Methane Concentrations and Fluxes on the North Slope of Alaska

    NASA Astrophysics Data System (ADS)

    Smith, J. P.; Suriben, R. S.; Coffin, R. B.; Boyd, T. J.; Rose, P. S.; Douglas, T. A.; Millholland, L. C., IV; Boudart, E. R.; Woods, J. E.

    2014-12-01

    Scientific evidence indicates wide-scale changes in Arctic climate. The Arctic contains large expanses of tundra with permafrost, or permanently frozen subsoil. Climate change impacts on the tundra have the potential to enhance biogenic methane (CH4) production in thawed, active soils or release CH4 trapped in or below the permafrost. Methane is a highly effective greenhouse gas so CH4 released from thawing tundra or melting massive ice features constitutes a potential positive feedback to Arctic climate change. In August, 2013 the U.S. Naval Research Laboratory (NRL-6114) led an expedition to investigate late-summer tundra CH4 concentrations and fluxes on the North Slope of Alaska near Prudhoe Bay. Permafrost cores were collected to measure tundra CH4 concentrations and soil parameters and a series of gas traps were deployed to measure tundra CH4 flux at 9 locations spread across a study area of ~1800 km2. Thaw probe measurements at each site provided information on the depth of the seasonally-thawed (active) layer. Results show large differences in tundra CH4 concentrations with depth through the active layer and into the upper permafrost terrain and fine-scale variability in daily CH4 flux over a relatively small spatial area. It is likely that variations in biogeochemical and geomorphological characteristics such as soil composition, microbial activity, moisture type, active layer composition and extent from site-to-site control the CH4 regime. In order to provide more accurate estimates of permafrost tundra CH4 storage and fluxes, controls on CH4 variability from location to location must be better understood. Further research is required to quantify and predict tundra CH4 flux in order to better understand the potential impact it will have on Arctic climate, particularly if, as predicted, climate warming leads to the liberation of permafrost carbon in these landscapes.

  3. Late Holocene Asian summer monsoon variability reflected by δ18O in tree-rings from Tibetan junipers

    NASA Astrophysics Data System (ADS)

    Grießinger, Jussi; Bräuning, Achim; Helle, Gerd; Thomas, Axel; Schleser, Gerhard

    2011-02-01

    Recent warming in High Asia might have a strong impact on Asian summer monsoon variability with consequences for the hydrological cycle. Based on correlations between climate data, the tree-ring δ18O of high-elevation junipers is an indicator of August precipitation. Thus, our 800-year long annually resolved oxygen isotope series reflects long-term variations in summer monsoon activity on the southern Tibetan plateau. Summer precipitation was reduced during 13th-15th centuries and since the 19th century, whereas the Little Ice Age period (15th-19th century) was rather moist. The late 20th century was among the driest periods during the past 800 years, showing a tendency to slightly wetter conditions after AD 1990.

  4. Vertical tectonics in northern Escanaba Trough as recorded by thick late Quaternary turbidites

    USGS Publications Warehouse

    Normark, W.R.; Serra, F.

    2001-01-01

    Escanaba Trough, the southernmost segment of the Gorda Ridge, is filled by as much as 500 m of late Quaternary turbidite and hemipelagic sediment. Coring at Deep Sea Drilling Project Site 35 and Ocean Drilling Program (ODP) Sites 1037 and 1038 together with 4.5-kHz deep-tow and 3.5-kHz surface-ship seismic reflection profiles enable a distinct pattern of reflections to be mapped throughout Escanaba Trough in the upper part of this sediment fill. The uppermost 80 m of turbidite sediment, which includes at least 11 turbidity current events, were deposited in 3200 m. The turbidity currents were trapped upon entering Escanaba Trough, resulting in all of the sediment in suspension in the flows being deposited. The thickness of the turbidite layers reflects both the flow thickness and the vertical grain concentration within the flow that deposited the layer. Variations in the turbidite thickness with respect to water depth can be used to estimate the degree of relative vertical movement within the floor of Escanaba Trough. In the area of hydrothermal activity near ODP Site 1038, uplift of as much as 140 m has occurred over the past 8 kyr. Copyright 2001 by the American Geophysical Union.

  5. Zooplankton data: Vertical distributions of zooplankton in the Norweigian and Greenland Seas during summer, 1989

    SciTech Connect

    Lane, P.V.Z.; Smith, S.L.; Schwarting, E.M.

    1993-08-01

    Recent studies of zooplankton populations in the Greenland Sea have focused on processes at the Marginal Ice Zone (MIZ) and the areas immediately adjacent to it under the ice and in open water. These studies have shown a relatively short period of intense secondary productivity which is closely linked temporally and spatially to phytoplankton blooms occurring near the ice edge in spring and early summer. During the summer of 1989 we participated in a project focusing on benthic and water column processes in the basins of the Norwegian and Greenland Seas. This study allowed us to compare biological processes at the MIZ with those occurring in the open waters of the Greenland Sea, and to compare processes at both of these locations with those in the Norwegian Sea. The data presented in this report are the results of zooplankton net tows covering the upper 1000 meters of the water column over the Norwegian Sea basin and the Greenland Sea basin, and the upper 500 meters of open water adjacent to the MIZ in the Greenland Sea. Sampling was conducted between 12 and 29 July 1989.

  6. Proteome dataset of subcutaneous adipose tissue obtained from late pregnant dairy cows during summer heat stress and winter seasons.

    PubMed

    Zachut, M; Kra, G; Livshitz, L; Portnick, Y; Yakoby, S; Friedlander, G; Levin, Y

    2017-06-01

    Adipose tissue has a central role in the regulation of metabolism in dairy cows, and many proteins expressed in this tissue are involved in metabolic responses to stress (Peinado et al., 2012) [1]. Environmental heat stress is one of the main stressors limiting production in dairy cattle (Fuquay, 1981; West, 2003) [2], [3], and there is a complex interaction between heat stress and the transition period from late pregnancy to onset of lactation, which is manifested in heat-stressed late-gestation cows (Tao and Dahl, 2013) [4]. We recently defined the proteome of adipose tissue in peripartum dairy cows, identifying 586 proteins of which 18.9% were differentially abundant in insulin-resistant compared to insulin-sensitive adipose tissue (Zachut, 2015) [5]. That study showed that proteomic techniques constitute a valuable tool for identifying novel biomarkers in adipose tissue that are related to metabolic adaptation to stress in dairy cows. The objective of the present work was to examine the adipose tissue proteome under thermo-neutral or seasonal heat stress conditions in late pregnant dairy cows. We have collected subcutaneous adipose tissue biopsies from 10 late pregnant dairy cows during summer heat stress and from 8 late pregnant dairy cows during winter season, and identified and quantified 1495 proteins in the adipose tissues. This dataset of adipose tissue proteome from dairy cows adds novel information on the variety of proteins that are abundant in this tissue during late pregnancy under thermo-neutral as well as heat stress conditions. Differential abundance of 107 (7.1%) proteins was found between summer and winter adipose. These results are discussed in our recent research article (Zachut et al., 2017) [6].

  7. Vertical distribution of suspended particulate matter in the Caspian Sea in early summer

    NASA Astrophysics Data System (ADS)

    Kravchishina, M. D.; Lein, A. Yu.; Pautova, L. A.; Klyuvitkin, A. A.; Politova, N. V.; Novigatsky, A. N.; Silkin, V. A.

    2016-11-01

    The features of the vertical distribution of chlorophyll a, particulate organic carbon and its isotopic composition, total suspended particulate matter (SPM), and the structure of the phytoplankton community in the Middle and South Caspian Sea in May-June 2012 are discussed. The subsurface chlorophyll a maximum (SCM) was found everywhere at depths of 20 to 40-60 m. The position of this layer is confined to the depth of the seasonal thermocline, which is determined by the development of a cold-water (dark) phytocenosis. The genesis of this layer was studied. The increase in chlorophyll a concentration in this layer is caused by an abundance of phytoplankton or an increased concentration of this phytopigments per algal cell. The highest values of the studied organic compounds and phytoplankton biomass are revealed as close to the seasonal thermocline extending from the southern periphery of the Derbent Depression to the Apsheron Sill, which is determined by the bottom topography. The presence of chlorophyll a at depths exceeding 300 m (up to ≥1 mg/m3) was revealed. This was supported by findings of individual algal cells containing chlorophyll a and even their accumulations in the deep water layer. The most probable mechanisms responsible for the presence of these cells at the deep water level are discussed in the paper. The vertical distribution of the values of the organic carbon isotopic composition is primarily controlled by the vertical structure of phytoplankton and chlorophyll a in the water column up to 500 m and by biogeochemical processes at the redox barrier ( 600 m layer). The relative stability of chlorophyll a and the stability of pheophytin a in anaerobic environments were verified. A significant amount of weakly transformed chlorophyll a was found close the sea bottom.

  8. Late Cretaceous paleomagnetism of the Tucson Mountains: Implications for vertical axis rotations in south central Arizona

    NASA Astrophysics Data System (ADS)

    Hagstrum, Jonathan T.; Lipman, Peter W.

    1991-09-01

    The Tucson Mountains of southern Arizona are the site of an Upper Cretaceous caldera from which the rhyolitic Cat Mountain Tuff was erupted at about 72 Ma. Two magnetic units within the Cat Mountain Tuff are distinguished by paleomagnetic data in both the northern and southern Tucson Mountains. The resurgent Amole pluton (≃72 Ma) in the northern Tucson Mountains was emplaced soon after eruption of the Cat Mountain Tuff but cooled and was magnetized after northeastward tilting (50°-85°) of the adjacent caldera-fill sequence. Petrologic and paleomagnetic data indicate that the lower magnetic unit of the Cat Mountain Tuff caps the Silver Bell Mountains to the northwest. A previous paleomagnetic investigation (N = 34) indicates that the Silver Bell Mountains have been rotated clockwise 30°±16° (95% confidence level) about a vertical axis relative to cratonic North America. A similar paleomagnetic study of Upper Cretaceous volcanic, volcaniclastic, and intrusive units in the Tucson Mountains (N = 26) indicates that these rocks have been rotated 7°±14° clockwise relative to stable North America. A direct comparison of paleomagnetic directions for the lower unit of the Cat Mountain Tuff shows a 17°±10° clockwise rotation between the Silver Bell Mountains and the Tucson Mountains which supports the relative accuracy of the absolute rotations determined for these two mountain ranges. Preliminary paleomagnetic directions for middle Tertiary units from the Silver Bell and Tucson Mountains are consistent with clockwise rotation having occurred prior to deposition of these rocks. Clockwise rotation of crustal blocks in southern Arizona likely was associated with strike-slip movement on major northwest trending faults in the region, and this movement may have been related to oblique subduction of oceanic plates along the western continental margin in Late Cretaceous and early Tertiary time. The available paleomagnetic data indicate that rocks in southern Arizona

  9. The Vertical Characteristics of Temperature inside Summer Monsoon Precipitating Clouds as Measured by TRMM PR and IGRA

    NASA Astrophysics Data System (ADS)

    Fu, Yun-Fei

    2017-04-01

    To reveal the nature of the vertical structure of temperature and humidity inside precipitating clouds, a quasi-spatiotemporal synchronization dataset of temperature and humidity profiles, collocated with precipitation profiles, is generated in this study by merging Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) and the Integrated Global Radiosonde Archive (IGRA) from 1998 to 2012. Based on this dataset, the characteristics of precipitation, temperature, humidity and convective available potential energy (CAPE) in the East Asian Summer Monsoon (EASM) region and Indian Summer Monsoon (ISM) region are investigated. Case studies indicate wet air in the atmospheric column inside deep convective precipitating clouds, together with weak wind in the upper atmosphere; while for stratiform precipitating clouds, wet air occurs below the layer of 850 hPa, accompanied by decreasing humidity and strengthening wind with height. Statistics illustrate a heavier precipitation intensity in the EASM region than in the ISM region, and the heights of storm tops can reach 17 km and 12 km for convective and stratiform precipitation, respectively, in the EASM region. Usually, the height of storm tops in the ISM is 1 km lower than that in the EASM region. Moreover, results also indicate that convective precipitation in the ISM is greatly impacted by the propagation of the monsoon. The significant difference of temperature for the precipitation scenario between the EASM region and ISM region also appears near the surface, i.e. about 4°C higher in the ISM than in the EASM region. Generally, relative dryer air occurs inside convective precipitating clouds in the ISM region, as compared to in the EASM region, and there is a larger CAPE precipitation scenario in the ISM region than in the EASM region.

  10. Late-summer sea ice segmentation with multi-polarisation SAR features in C and X band

    NASA Astrophysics Data System (ADS)

    Fors, Ane S.; Brekke, Camilla; Doulgeris, Anthony P.; Eltoft, Torbjørn; Renner, Angelika H. H.; Gerland, Sebastian

    2016-02-01

    In this study, we investigate the potential of sea ice segmentation by C- and X-band multi-polarisation synthetic aperture radar (SAR) features during late summer. Five high-resolution satellite SAR scenes were recorded in the Fram Strait covering iceberg-fast first-year and old sea ice during a week with air temperatures varying around 0 °C. Sea ice thickness, surface roughness and aerial photographs were collected during a helicopter flight at the site. Six polarimetric SAR features were extracted for each of the scenes. The ability of the individual SAR features to discriminate between sea ice types and their temporal consistency were examined. All SAR features were found to add value to sea ice type discrimination. Relative kurtosis, geometric brightness, cross-polarisation ratio and co-polarisation correlation angle were found to be temporally consistent in the investigated period, while co-polarisation ratio and co-polarisation correlation magnitude were found to be temporally inconsistent. An automatic feature-based segmentation algorithm was tested both for a full SAR feature set and for a reduced SAR feature set limited to temporally consistent features. In C band, the algorithm produced a good late-summer sea ice segmentation, separating the scenes into segments that could be associated with different sea ice types in the next step. The X-band performance was slightly poorer. Excluding temporally inconsistent SAR features improved the segmentation in one of the X-band scenes.

  11. Extreme late-summer drought causes neutral annual carbon balance in southwestern ponderosa pine forests and grasslands

    NASA Astrophysics Data System (ADS)

    Kolb, Thomas; Dore, Sabina; Montes-Helu, Mario

    2013-03-01

    We assessed the impacts of extreme late-summer drought on carbon balance in a semi-arid forest region in Arizona. To understand drought impacts over extremes of forest cover, we measured net ecosystem production (NEP), gross primary production (GPP), and total ecosystem respiration (TER) with eddy covariance over five years (2006-10) at an undisturbed ponderosa pine (Pinus ponderosa) forest and at a former forest converted to grassland by intense burning. Drought shifted annual NEP from a weak source of carbon to the atmosphere to a neutral carbon balance at the burned site and from a carbon sink to neutral at the undisturbed site. Carbon fluxes were particularly sensitive to drought in August. Drought shifted August NEP at the undisturbed site from sink to source because the reduction of GPP (70%) exceeded the reduction of TER (35%). At the burned site drought shifted August NEP from weak source to neutral because the reduction of TER (40%) exceeded the reduction of GPP (20%). These results show that the lack of forest recovery after burning and the exposure of undisturbed forests to late-summer drought reduce carbon sink strength and illustrate the high vulnerability of forest carbon sink strength in the southwest US to predicted increases in intense burning and precipitation variability.

  12. Inverse relation between summer and winter monsoon strength during late Holocene: continental molecular isotopic record from the Indian subcontinent

    NASA Astrophysics Data System (ADS)

    Sanyal, P.; Basu, S.; Pillai, A.; Singh, P.; Ratnam, J.; Sankaran, M.; Amibili, A.

    2015-12-01

    The Indian monsoon shapes the livelihood of ca. 40% of world's population. Despite dedicated efforts, comprehensive picture of monsoon variability has proved elusive largely due to the absence of long-term qualitative high-resolution record from key climatic zones and variability of monsoon with respect to various forcing mechanisms (e.g., solar insolation) and teleconnections (e.g., El Niño-Southern Oscillation, Indian Ocean Dipole). In this study, high-resolution molecular (n-alkane) isotopic (δD and δ13C ratios) reconstruction of mid-late Holocene (~5.0 cal ka) climate has been undertaken using lacustrine sediments from two climatically sensitive regions; (i) Arid Banni grasslands, western India with dominant moisture source derived from Indian summer monsoon (June-September) and (ii) Semi-arid Ennamangalam lake, south India with significant fraction of rainfall received during winter period (October to December) from Northeast (NE) monsoon. The climate reconstruction from western India based on δDn-alkane values shows prevalence of intensified monsoon until ca. 3 cal ka followed by gradual decrease in the precipitation. In contrast, climate reconstruction from south India is characterized by more negative δDn-alkane (intensified precipitation) values during late Holocene (~2.5 cal ka). The compilation of paleoclimate records shows that the precipitation pattern in Banni region responded linearly to gradually changing insolation and additionally amplified by climate systems like ENSO. However, intensified monsoon in South India shows strengthened NE monsoonal precipitation during late Holocene. The spatial inhomogeneity in the palaeohydrological record can be attributed to the persistence of inverse relationship between summer and winter monsoon. In addition, strong positive correlation between δDn-alkane and δ13Cn-alkane values from both region shows that the relative abundance of C3-C4 plants in the contemporary ecosystems are governed by rainfall

  13. Evaluation of modeled vertical aerosol distributions over east-Asia using in-situ and satellite data during summer 2008

    NASA Astrophysics Data System (ADS)

    Quennehen, Boris; Raut, Jean-Christophe; Law, Kathy S.; Thomas, Jennie L.; Ancellet, Gérard; Bazureau, Ariane; Daskalakis, Nikos; Kim, Sang-Woo; Yoon, Soon-Chang; Zhu, Tong; Pelon, Jacques

    2013-04-01

    As part of the EU ECLIPSE project, which aims to quantify the climate impact of short lived climate forcers (SLCFs), including aerosols, black carbon and ozone, regional models are being used to evaluate global model performance for specific case studies. Here, we present results using regional WRF-Chem simulations over east-Asia. Results are compared to data from field campaigns which took place in summer 2008 and from long-term measurement stations. This study will, in a first step, evaluate the ability of the model to simulate aerosol physical, chemical and optical properties, with a focus on pollution layers. In a second step, the radiative impact of such layers over east-Asia will be investigated as a function of their position relative to clouds. The WRF-Chem regional model was run using MOZART gas phase chemistry and the MOSAIC aerosol scheme and was evaluated against available measurements for the period August to September 2008. The model was run using ECLIPSE anthropogenic and GFEDv3.1 fire emissions for 2008, while initial and boundary conditions were specified from the TM4 global chemical transport model. The radiative impact of pollution aerosol layers has already been investigated but less is known about the influence of vertical layering in the atmosphere. Such layers might have different radiative impacts whether they are below or above clouds and in that sense, a better understanding of their spatial extent is critical. Information about pollution aerosol layers and clouds optical properties and positions over East-Asia are determined using observations from CALIPSO. The radiative impact of these layers is simulated and compared to the observations. In addition to satellite observations, model results are evaluated against trace gas and aerosol data from aircraft campaigns over eastern Asia in summer 2008 (e.g., CAREBEIJING and CAPMEX) and ground-based measurements (e.g., NIES and ABC). In this study, we assess aerosol total concentrations and size

  14. Dynamics of late spring and summer phytoplankton communities on Georges Bank, with emphasis on diatoms, Alexandrium spp., and other dinoflagellates

    NASA Astrophysics Data System (ADS)

    Gettings, Rachel M.; Townsend, David W.; Thomas, Maura A.; Karp-Boss, Lee

    2014-05-01

    We analyzed the distribution, abundance, and succession patterns of major phytoplankton taxa on Georges Bank in relation to hydrography, nutrients, and size-fractionated chlorophyll concentrations (>20 μm; <20 μm) on three oceanographic cruises from late spring through summer 2008 (28 April-5 May, 27 May-4 June, and 27 June-3 July). The April-May phytoplankton community was dominated numerically by the diatoms Skeletonema spp., Thalassiosira spp., Coscinodiscus spp., and Chaetoceros spp., with highest total diatom cell densities exceeding 200,000 cells l-1 on the Northeast Peak. In May-June, low nitrate and silicate concentrations over the Bank, along with patches of slightly elevated ammonium, were apparently supporting a predominantly dinoflagellate population; the toxic dinoflagellate Alexandrium spp. reached 13,000 cells l-1. Diatom cell densities on the second cruise in May-June were less than 60,000 cells l-1 and their spatial distributions did not overlap with the highest cell densities of Alexandrium spp. or other dinoflagellates. On the third and last cruise, in June-July, reduced nitrate and silicate concentrations were accompanied by a shift in the phytoplankton community: Alexandrium spp. cell densities were lower and heterotrophic and mixotrophic dinoflagellates, notably Polykrikos spp., Gyrodinium spp., Gymnodinium spp., and Prorocentrum spp., had become more abundant. Patches of regenerated silicate during the June-July period appeared to support a post-spring-bloom diatom community on the central crest of the Bank (total diatom cell densities >180,000 cellsl-1) of Leptocylindrus spp., Dactyliosolen spp., and Guinardia flaccida. Multivariate statistical analyses of phytoplankton taxa and station locations revealed distinct assemblages of diatom and dinoflagellate taxa on the Bank throughout the late spring and summer. Results are interpreted in the ecological context of earlier-reported laboratory culture experiments on the competitive interactions

  15. Late summer photosynthesis and storage carbohydrates in walnut (Juglans regia L.): Feed-back and feed-forward effects.

    PubMed

    Moscatello, Stefano; Proietti, Simona; Augusti, Angela; Scartazza, Andrea; Walker, Robert P; Famiani, Franco; Battistelli, Alberto

    2017-09-01

    The effect of late summer - autumn limitation of phloem export on growth, photosynthesis and storage carbohydrate accumulation, was evaluated in walnut (Juglans regia L.). This was done by girdling current years shoots, with either all or with only a third of the leaves left in place. Nineteen days after girdling, photosynthesis was greatly reduced and after 46 days, it was about 70% lower in both girdling treatments compared to the control (ungirdled shoots). This reduction is consistent with a feed-back effect of an increased carbohydrate content of the leaves. At the end of the experiment (46 days after girdling), the radial growth of girdled shoots was increased at their base but not at their apical part compared to the control. Girdling increased the accumulation of sucrose in the bark at the base of the shoot and of starch in the bark and in the wood of the shoot apical part. The activity of ADP-glucose pyrophosphorylase in wood increased in the apical part of girdled shoots. The results suggest that a high availability of carbohydrates elicits a feed-forward action on the shoot sink size and activity (radial growth and storage carbohydrate accumulation). Further, for the first time in tree wood we found an increased total activity of AGP induced by an increased assimilate availability. Moreover, the results indicated that, in late summer - autumn, CO2 uptake by leaves of the deciduous tree walnut is strongly dependent on export of photosynthates from the crown. Therefore, carbon uptake in this period depends largely on the availability of effective storage sinks where newly produced assimilates can be accumulated. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  16. Vitamin D status and its determinants in children and adults among families in late summer in Denmark.

    PubMed

    Madsen, Katja H; Rasmussen, Lone B; Mejborn, Heddie; Andersen, Elisabeth W; Mølgaard, Christian; Nissen, Janna; Tetens, Inge; Andersen, Rikke

    2014-09-14

    The impact of the familial relationship on vitamin D status has not been investigated previously. The objective of the present cross-sectional study was to assess serum 25-hydroxyvitamin D (25(OH)D) concentration and its determinants in children and adults among families in late summer in Denmark (56°N). Data obtained from 755 apparently healthy children (4-17 years) and adults (18-60 years) recruited as families (n 200) in the VitmaD study were analysed. Blood samples were collected in September-October, and serum 25(OH)D concentration was measured by liquid chromatography-tandem MS. Information on potential determinants was obtained using questionnaires. The geometric mean serum 25(OH)D concentration was 72·1 (interquartile range 61·5-86·7) nmol/l (range 9-162 nmol/l), with 9 % of the subjects having 25(OH)D concentrations < 50 nmol/l. The intra-family correlation was 0·27 in all subjects, 0·24 in the adults and 0·42 in the children. Serum 25(OH)D concentration was negatively associated with BMI (P< 0·001) and positively associated with dietary vitamin D intake (P= 0·008), multivitamin use (P= 0·019), solarium use (P= 0·006), outdoor stay (P= 0·001), sun preference (P= 0·002) and sun vacation (P< 0·001), but was not associated with lifestyle-related factors in the adults when these were assessed together with the other determinants. In conclusion, the majority of children and adults among the families had serum 25(OH)D concentrations >50 nmol/l in late summer in Denmark. Both dietary and sun-related factors were determinants of vitamin D status and the familial component was stronger for the children than for the adults.

  17. Atmospheric and surface temperatures and airborne dust amounts during late southern summer from Mariner 9 IRIS data

    NASA Technical Reports Server (NTRS)

    Santee, M.; Crisp, D.

    1992-01-01

    The temperature structure and dust loading of the Martian atmosphere are investigated using thermal emission spectra recorded in 1972 by the Mariner 9 infrared interferometer spectrometer (IRIS). The analysis focuses on a subset of data consisting of approximately 2400 spectra obtained near the end of the southern summer season (L(sub s) equal to 343 deg to 348 deg), after the global dust storm had largely abated and airborne dust amounts were subsiding to background values. Simultaneous retrieval of the vertical distribution of both atmospheric temperature and dust optical depth is accomplished through an iterative procedure which is performed on each individual spectrum. The atmospheric transmittances are calculated using a Voigt quasi-random band model, which includes absorption by CO2 and dust, but neglects the effects of multiple scattering. Vertical profiles of temperature and dust optical depth are obtained using modified algorithms. These profiles are used to construct global maps of temperature and dust optical depth as functions of latitude (+/- 90 deg), altitude (approximately 0-50 km), and local time of day.

  18. Amplified melt and flow of the Greenland ice sheet driven by late-summer cyclonic rainfall

    NASA Astrophysics Data System (ADS)

    Doyle, Samuel H.; Hubbard, Alun; van de Wal, Roderik S. W.; Box, Jason E.; van As, Dirk; Scharrer, Kilian; Meierbachtol, Toby W.; Smeets, Paul C. J. P.; Harper, Joel T.; Johansson, Emma; Mottram, Ruth H.; Mikkelsen, Andreas B.; Wilhelms, Frank; Patton, Henry; Christoffersen, Poul; Hubbard, Bryn

    2015-08-01

    Intense rainfall events significantly affect Alpine and Alaskan glaciers through enhanced melting, ice-flow acceleration and subglacial sediment erosion, yet their impact on the Greenland ice sheet has not been assessed. Here we present measurements of ice velocity, subglacial water pressure and meteorological variables from the western margin of the Greenland ice sheet during a week of warm, wet cyclonic weather in late August and early September 2011. We find that extreme surface runoff from melt and rainfall led to a widespread acceleration in ice flow that extended 140 km into the ice-sheet interior. We suggest that the late-season timing was critical in promoting rapid runoff across an extensive bare ice surface that overwhelmed a subglacial hydrological system in transition to a less-efficient winter mode. Reanalysis data reveal that similar cyclonic weather conditions prevailed across southern and western Greenland during this time, and we observe a corresponding ice-flow response at all land- and marine-terminating glaciers in these regions for which data are available. Given that the advection of warm, moist air masses and rainfall over Greenland is expected to become more frequent in the coming decades, our findings portend a previously unforeseen vulnerability of the Greenland ice sheet to climate change.

  19. Contrasting ice sheet response to early and late summer rapid supraglacial lake drainage events on the Greenland Ice Sheet

    NASA Astrophysics Data System (ADS)

    Stevens, L. A.; Behn, M. D.; Das, S. B.; Joughin, I. R.; Herring, T.; King, M. A.; McGuire, J. J.

    2013-12-01

    Across much of the ablation region of the western Greenland Ice Sheet, hydro-fracture events related to supraglacial lake drainages rapidly deliver large volumes of meltwater to the bed and create conduits providing efficient surface-to-bed drainage networks for the remainder of the summer melt season. Using a network of 20 GPS stations installed in 2011, and supplemented with a smaller network operating back to 2006, we observe ice surface motion during a series of lake draining hydro-fracture events. These data are used to investigate (1) the location and propagation geometry of the fracture opening and (2) the acceleration of ice in response to the rapid input of surface meltwater to the bed. Observations at the same location show varying surface motion following early versus late summer rapid lake drainage events from multiple years. During a late-season (July 29) rapid drainage in 2006, results from a single GPS station show velocity in the direction of mean ice flow and surface uplift returned to pre-drainage values within ~24 hours (Das et al., 2008), indicating the large subglacial meltwater pulse was efficiently dissipated into the subglacial hydrologic network. In contrast, an early-season (June 11) rapid drainage at the same lake in 2011 induced uplift that persisted for much longer. Specifically, we find that elevations at stations nearest the moulin did not return to pre-drainage elevations for 4 to 8 days post-drainage, suggesting a more inefficient subglacial hydrologic system during the early summer season. These results indicate that the ice-sheet response is modulated, at least in part, by the seasonal evolution of the subglacial hydrological system. We also plan to investigate new GPS data from 2 rapid drainage events in the early portion of the melt season in 2012 and 2013. Findings from these events will ultimately improve our understanding of the mechanics of ice-sheet hydro-fracture and the influence of surface meltwater on ice-sheet flow.

  20. Dynamic-analogue correction of the decadal change of East Asian summer precipitation in the late 1990s

    NASA Astrophysics Data System (ADS)

    Gong, Zhiqiang; Li, Shangfeng; Hu, Po; Shen, Baizhu; Feng, Guolin

    2016-06-01

    This paper systematically evaluates the deviations that appear in the hindcasts of the East Asian summer precipitation (EASP) decadal change in the late 1990s in two global coupled models (BCC_CGCM and BCC_CSM). The possible causes for the deviations between the model hindcasts and observations are analyzed. The results show that the hindcasts of EASP by BCC_CGCM and BCC_CSM deviate from observations, with the anomaly correlation coefficient (ACC) being -0.01 and -0.09 for the two models, respectively. The SST anomalies in North and West Pacific and the SST index values predicted by the two models also deviate from the observations, indicating that inconsistent SST fields may be the key factor leading to the deviation in the prediction of the EASP decadal shift. Thus, a dynamic-analogue scheme is proposed to correct the precipitation hindcasts by using SSTs, where SST and EASP are highly correlated, to select historical analogue cases. Cross validations show that the average ACC of the temporal-latitude distribution of the EASP between the corrected hindcasts and observations is 0.18 for BCC_CGCM and 0.02 for BCC_CSM; both are much higher than the uncorrected hindcasts. Applying the dynamic-analogue correction scheme in both models successfully improves prediction of the EASP decadal change in the late 1990s.

  1. Effect of the early and late onset of summer monsoon over the Bay of Bengal on Asian precipitation in May

    NASA Astrophysics Data System (ADS)

    Xing, Nan; Li, Jianping; Wang, Lanning

    2016-09-01

    The impact of early and late Bay of Bengal (BoB) summer monsoon (BoBSM) onset on Asian precipitation in May is investigated. When the BoBSM occurs earlier (later), May rainfall tends to be enhanced (suppressed) in the southern Indian peninsula (SIP), the Indochinese peninsula (ICP), southwest China (SWC) and the South China Sea (SCS), while south China (SC) rainfall tends to be suppressed (enhanced). When the BoBSM occurs earlier than the climatological mean (late April), strong convective activity emerges earlier over the BoB, which causes local strong convective heating earlier. Then, earlier spread of heating in the BoB towards both sides leads to earlier retreat of the subtropical highs in the western Pacific (WPSH) and Indian Ocean outwards the BoB. Thus, compared to the climatological mean, the two subtropical highs present larger retreat outwards the BoB and smaller meridional extent over the SCS and Arabian Sea in May, which contributes to positive heating anomalies over the SCS and Arabian Sea. Therefore, anomalous cyclonic circulations occur over the BoB, SCS and Arabian Sea in May. Anomalous cyclonic circulation is favorable for low-level convergence over the SIP, and thus resulting in local heavy rainfall. Associated with cyclonic circulation anomalies over the BoB and SCS, anomalous low-level convergent winds and ascending flows favor positive precipitation anomalies in the ICP, SWC, and SCS, while anomalous northeasterlies and descending flows affected by the southward retreat of the WPSH lessen SC rainfall. In late onset years the opposite occurs.

  2. Effect of the early and late onset of summer monsoon over the Bay of Bengal on Asian precipitation in May

    NASA Astrophysics Data System (ADS)

    Xing, Nan; Li, Jianping; Wang, Lanning

    2016-04-01

    The impact of early and late Bay of Bengal (BoB) summer monsoon (BoBSM) onset on Asian precipitation in May is investigated. When the BoBSM occurs earlier (later), May rainfall tends to be enhanced (suppressed) in the southern Indian peninsula (SIP), the Indochinese peninsula (ICP), southwest China (SWC) and the South China Sea (SCS), while south China (SC) rainfall tends to be suppressed (enhanced). When the BoBSM occurs earlier than the climatological mean (late April), strong convective activity emerges earlier over the BoB, which causes local strong convective heating earlier. Then, earlier spread of heating in the BoB towards both sides leads to earlier retreat of the subtropical highs in the western Pacific (WPSH) and Indian Ocean (IOSH) outwards the BoB. Thus, compared to the climatological mean, the two subtropical highs present larger retreat outwards the BoB and smaller meridional extent over the SCS and Arabian Sea in May, which contributes to positive heating anomalies over the SCS and Arabian Sea. Therefore, anomalous cyclonic circulations occur over the BoB, SCS and Arabian Sea in May. Anomalous cyclonic circulation is favorable for low-level convergence over the SIP, and thus resulting in local heavy rainfall. Associated with cyclonic circulation anomalies over the BoB and SCS, anomalous low-level convergent winds and ascending flows favor positive precipitation anomalies in the ICP, SWC, and SCS, while anomalous northeasterlies and descending flows affected by the southward retreat of the WPSH lessen SC rainfall. In late onset years the opposite occurs.

  3. Reconstruction of Late Glacial summer temperatures from chironomid assemblages in Lac Lautrey (Jura, France)

    NASA Astrophysics Data System (ADS)

    Heiri, Oliver; Millet, Laurent

    2005-01-01

    A chironomid-July air temperature inference model based on chironomid assemblages in the surface sediments of 81 Swiss lakes was used to reconstruct Late Glacial July air temperatures at Lac Lautrey (Jura, Eastern France). The transfer-function was based on weighted averaging-partial least squares (WA-PLS) regression and featured a leave-one-out cross-validated coefficient of determination (r2) of 0.80, a root mean square error of prediction (RMSEP) of 1.53 ° C, and was applied to a chironomid record consisting of 154 samples covering the Late Glacial period back to the Oldest Dryas. The model reconstructed July air temperatures of 11-12 ° C during the Oldest Dryas, increasing temperatures between 14 and 16.5 ° C during the Bølling, temperatures around 16.5-17.0 ° C for most of the Allerød, temperatures of 14-15 ° C during the Younger Dryas and temperatures of ca. 16.5 ° C during the Preboreal. The Lac Lautrey record features a two-step July air temperature increase after the Oldest Dryas, with an abrupt temperature increase of ca. 3-3.5 ° C at the Oldest Dryas/Bølling transition followed by a more gradual warming between ca. 14 200 and 13 700 BP. The transfer-function reconstructs a less rapid cooling at the Allerød/Younger Dryas transition than other published records, possibly an artefact caused by the poor analogue situation during the earliest Younger Dryas, and an abrupt warming at the Younger Dryas/Holocene transition. During the Allerød, two centennial-scale 1.5-2.0 ° C coolings are apparent in the record. Although chronologically not well constrained, the first of these cold events may be synchronous with the beginning of the Gerzensee Oscillation. The second is inferred just before deposition of the Laachersee tephra at Lac Lautrey and is therefore coeval with the end of the Gerzensee Oscillation. In contrast to the Greenland oxygen isotope records, the Lac Lautrey palaeotemperature reconstruction lacks a clearly defined Greenland

  4. Late Pleistocene-Holocene vegetation and Indian summer monsoon record from the Lahaul, Northwest Himalaya, India

    NASA Astrophysics Data System (ADS)

    Rawat, Suman; Gupta, Anil K.; Sangode, S. J.; Srivastava, Priyeshu; Nainwal, H. C.

    2015-04-01

    The high resolution Holocene paleomonsoon records from Northwest (NW) Himalaya are limited. The carbon isotope (δ13C), Total organic carbon (TOC) and pollen analysis were therefore carried out from a peat-lake sediment sequence developed in alpine meadows of the Chandra valley, Lahaul, NW Himalaya, in order to reconstruct centennial to millennial scale vegetational changes and Indian summer monsoon (ISM) variability during the Holocene. The chronology of peat-lake sediments is constrained with 9 AMS 14C dates. The recovered non-arboreal pollen (NAP) suggested that during Holocene alpine desert-steppe, meadows and shrubs growing along the stream had developed in the Lahaul valley whereas arboreal pollens (AP) e.g. Pinus, Quercus, Cedrus and Ulmus presently growing in the southern hill slopes of Pir Panjal range indicated moisture carrying monsoonal air flow from the South. The increased δ13C and low TOC values between ∼12,880 and 11,640 calibrated years before present (cal yr BP) suggested weakening of ISM and low organic carbon production corresponding to the Younger Dryas (YD) cold event. The gradual depletion in carbon isotope ratio from ∼11,640 to 8810 cal yr BP indicated enhanced precipitation in the Chandra valley in response of increased ISM strength in early Holocene. The short spell of cold and dry climate with gradual decrease in ISM intensity between ca 10,398 and 9778 cal yr BP is closely linked with Bond event-7. The other prominent cold-dry events recorded in present study are (i) ∼8810 to 8117 cal yr BP roughly corresponding to global 8.2 ka cold event, (ii) ∼4808 to 4327 cal yr BP closely preceding the global 4.2 ka cold-arid period, and (iii) ∼1303 to 1609 cal AD corresponding to Little Ice Age (LIA) event. The expansion of thermophillous broad leaved taxa viz. Betula utilis, Alnus nepalensis, Quercus semicarpifolia and Juglans regia and effective growth of meadow vegetation such as grasses, Caryophyllaceae and Artemisia along with

  5. Utility of late summer transient snowline migration rate on Taku Glacier, Alaska

    NASA Astrophysics Data System (ADS)

    Pelto, M.

    2011-12-01

    On Taku Glacier, Alaska a combination of field observations of snow water equivalent (SWE) from snowpits and probing in the vicinity of the transient snowline (TSL) are used to quantify the mass balance gradient. The balance gradient derived from the TSL and SWE measured in snowpits at 1000 m from 1998-2010 ranges from 2.6-3.8 mm m-1. Probing transects from 950 m-1100 m directly measure SWE and yield a slightly higher balance gradient of 3.3-3.8 mm m-1. The TSL on Taku Glacier is identified in MODIS and Landsat 4 and 7 Thematic Mapper images for 31 dates during the 2004-2010 period to assess the consistency of its rate of rise and reliability in assessing ablation for mass balance assessment. For example, in 2010, the TSL was 750 m on 28 July, 800 m on 5 August, 875 m on 14 August, 925 m on 30 August, and 975 m on 20 September. The mean observed probing balance gradient was 3.3 mm m-1, combined with the TSL rise of 3.7 m day-1 yields an ablation rate of 12.2 mm day-1 from mid-July to mid-Sept, 2010. The TSL rise in the region from 750-1100 m on Taku Glacier during eleven periods each covering more than 14 days during the ablation season indicates a mean TSL rise of 3.7 m day-1, the rate of rise is relatively consistent ranging from 3.1 to 4.4 m day-1. This rate is useful for ascertaining the final ELA if images or observations are not available near the end of the ablation season. The mean ablation from 750-1100 m during the July-September period determined from the TSL rise and the observed balance gradient is 11-13 mm day-1 on Taku Glacier during the 2004-2010 period. The potential for providing an estimate of bn from TSL observations late in the melt season from satellite images combined with the frequent availability of such images provides a means for efficient mass balance assessment in many years and on many glaciers.

  6. Ice-free summers predominant in the late Miocene central Arctic Ocean - New insights from a proxy-modeling approach

    NASA Astrophysics Data System (ADS)

    Stein, Ruediger; Fahl, Kirsten; Schreck, Michael; Knorr, Gregor; Forwick, Matthias; Lohmann, Gerrit; Niessen, Frank

    2016-04-01

    During Polarstern Expedition PS87/2014, we discovered multiple submarine landslides over a distance of >350 km along Lomonosov Ridge between about 81°N and 84°N (Stein, 2015). The load and erosional behaviour of an extended ice sheet/shelf that probably occurred during major Quaternary glaciations, may have caused physical conditions that triggered these landslides and major down-slope transport of sediments at this part of Lomonosov Ridge (Stein et al., 2016 and further references therein). The removal of younger sediments from steep headwalls has led to exhumation of Miocene to early Quaternary sediments close to the seafloor, allowing the retrieval of such old sediments by gravity coring and multi-proxy studies of theses sediments. Within one of these studies (Stein et al., 2016), we used for the first time the sea-ice biomarker IP25 (for background of approach see Belt et al., 2007; Müller et al., 2009, 2011) together with alkenone-based sea-surface temperatures (SST) to reconstruct upper Miocene Arctic Ocean sea-ice and SST conditions. The presence of IP25 as proxy for spring sea-ice cover and alkenone-based relatively warm summer SST of >4 °C support a seasonal sea-ice cover with an ice-free summer season being dominant during (most of) the late Miocene central Arctic Ocean. A comparison of our proxy data with Miocene climate simulations seems to favour either relatively high late Miocene atmospheric CO2 concentrations and/or an overly weak sensitivity of the model to simulate the magnitude of high-latitude warming in a warmer than modern climate. References: Belt, S.T., Massé, G., Rowland, S.J., Poulin, M., Michel, and C., LeBlanc, B., 2007. A novel chemical fossil of palaeo sea ice: IP25, Organic Geochemistry 38, 16-27. Müller, J., Massé, G., Stein, R., and Belt, S., 2009. Extreme variations in sea ice cover for Fram Strait during the past 30 ka. Nature Geoscience, DOI: 10.1038/NGEO665. Müller, J., Wagner, A., Fahl, K., Stein, R., Prange, M., and

  7. Late summer disease symptoms in western Washington red raspberry fields associated with co-occurrence of Phytophthora rubi, Verticillium dahliae, and Pratylenchus penetrans

    USDA-ARS?s Scientific Manuscript database

    60% of the $109 million processed by the U.S. red raspberry industry is in northern Washington. In 2012, late summer disease symptoms were observed in many raspberry fields. These symptoms were initially attributed to Verticillium dahliae, but other soilborne pathogens (Phytophthora rubi, Pratylench...

  8. Herbage intake and milk production of late-lactation dairy cows offered a second-year chicory crop during summer.

    PubMed

    Muir, S K; Ward, G N; Jacobs, J L

    2015-12-01

    Chicory (Cichorum intybus L.) is a summer-active forage herb which has been proposed as an option to increase summer feed supply, increase dry matter intake, nutrient intake, and milk yield from nonirrigated dairy production systems in southern Australia. Dry matter intake, nutrient intake, milk yield, and yield of milk fat and protein of predominantly Holstein-Friesian dairy cows in late lactation consuming 3 herbage-based diets (4 replicates per treatment) were measured. The 3 grazed herbages were second-year chicory (CHIC) and perennial ryegrass (Lolium perenne L.; PRG) monocultures and a mixed sward (~50:50) of chicory and perennial ryegrass (MIX). All diets (CHIC, PRG, and MIX) were supplemented with alfalfa (Medicago sativa L.) hay (5.5kg of DM/cow per day) and an energy-based concentrate pellet (4.0kg of DM/cow per day). There were no significant differences in milk yield (12.0 to 12.6kg/d across the treatments) or the yield of milk fat (539 to 585g/d) and milk protein (433 to 447g/d) between the 3 herbage-based diets. No differences in DMI (17.9 to 19.2kg/d) or estimated metabolizable energy intake (173 to 185MJ/d) were noted between treatments. Estimated metabolizable energy concentrations in the forages on offer were lower in CHIC than PRG (7.6 vs. 8.2MJ/kg of dry matter), but the concentration in consumed herbage was not different (9.1 vs. 9.2MJ/kg of dry matter); as such, potential for increased milk yield in cows offered CHIC was limited. Increased concentration of polyunsaturated fatty acids was observed in chicory herbage compared with perennial ryegrass. This was associated with increased milk conjugated linoleic acid and milk polyunsaturated fatty acids when chicory formed part of the diet (CHIC compared to PRG and MIX). Chicory could be used as an alternative to perennial ryegrass in summer; however, the developmental stage of chicory will influence concentrations of metabolizable energy and neutral detergent fiber and, therefore, intake and milk

  9. Analysis of late spring-summer temperatures for Western Hungary based on vine, grain tithes and harvest records

    NASA Astrophysics Data System (ADS)

    Kiss, A.; Wilson, R.

    2009-04-01

    In Western Hungary, phenological evidence such as the beginning of grape ripening, vine harvest, tithe collection dates and, to some extent, harvested amounts, can provide proxy based evidence for late spring-summer temperatures. These data are almost continuous from the early 17th century, with some sporadic observations from the late 16th century. Based on these historical vine and grain series, this presentation describes the current status of historical climatology in Hungary. We initially focus on town council protocols, tithe and town accounts and vine harvest dates from the town of Kőszeg (Western Hungary). The historical series correlate well, over the 18th-19th century period, with Buda May-July temperature series, the Vienna-Burgerspital series (developed by Strömmer, E. 2003), and shorter eastern Hungarian series (e.g. Kecskemét and Gyöngyös). We also present preliminary historical data from Sopron (60 km north of Kőszeg) which show the potential of extending the regional proxy information almost continuously back to the early 16th, and with sporadic data to the 15th century. The complicated nature of the data is described (e.g. with respect to the normality of the data distribution) and we present methods to transform and composite the data into homogenous, homoscedastic time-series that can be used for proxy based calibration. Finally, a preliminary May-July temperature reconstruction is described which was derived using methods commonly used in dendroclimatology. All series and analyses presented were developed within the framework of the EU project 'Millenium'.

  10. Microbial community structure along 18°W (39°N-44.5°N) in the NE Atlantic in late summer 2001 (POMME programme)

    NASA Astrophysics Data System (ADS)

    Fernández, Camila; Thyssen, Melilotus; Denis, Michel

    The spatial and vertical distribution of heterotrophic prokaryotes and ultraphytoplankton (< 10 μm) was investigated by flow cytometry in the NE Atlantic Ocean (Programme Océan Multidisciplinaire Méso Echelle, POMME 3 cruise, 39°N-45°N) with the aim to document the relationships between these distributions and the hydrodynamic features prevailing in the NE Atlantic. A particular interest was given to the north-south transect 18°W (12 stations) because it crossed an anticyclonic cold-core SWODDY-type eddy (slope water oceanic anticyclonic eddy) and was sampled within less than 3 days. Four ultraphytoplankton (< 10 μm) groups ( Prochlorococcus, Synechococcus, pico- and nanoeukaryotes) were distinguished by flow cytometry on the basis of their optical properties (scatter, natural fluorescence). Three heterotrophic prokaryotes groups were resolved (two High Nucleic Acid: HNA1 and HNA2 and one Low Nucleic Acid: LNA) after nucleic acid staining. Results showed significant latitudinal variations in biogeochemical parameters as well as in ultraphytoplankton and heterotrophic prokaryote distribution. The inner domain of the eddy also showed variations in heterotrophic prokaryote abundances with respect to the spring situation [Thyssen, M., Lefèvre, D., Caniaux, G., Ras, J., Dugrais, L., Fernández I.C., Denis, M., 2005. Spatial distribution of heterotrophic bacteria in the North East Atlantic (POMME study area) during spring 2001. J. Geophys. Res., 110, C07S16, doi:10.1029/2004JC002670], with higher values of HNA2 during late summer. The same trend was observed on the abundance of cyanobacteria ( Prochlorococcus, Synechococcus) and small size ultraphytoplankton. Despite the observed differences in microbial distributions inside and outside the eddy, the biological features appeared insufficient to independently characterize this anticyclonic eddy and provide information on its microbial dynamics.

  11. Mid-late Holocene Paleoflood Reconstruction at Tianchi Lake, Liupan Mountains and its Possible Relation with Asian Summer Monsoon

    NASA Astrophysics Data System (ADS)

    Zhang, C.; Zhou, A.; Zhao, C.

    2016-12-01

    The flood, one of the major natural hazards, resulted in serious damages and losses of human life and economy frequently all over the world. As we see, human activity intensify the risk of flood hazards by changing global water cycle. However, the instrumental data only limited to the last 150 years, are too short to identify decadal to centennial-scale climatic fluctuations and discuss the climate-flood relationship. Therefore, we present a 6200-year long flood reconstruction from East Asian monsoon margin, based on reliable dated sedimentry flood deposits in Tianchi Lake. We display that 13 great floods are recorded in EM1 (end-member 1) decomposed from grain-size and these are verified by other proxies such as elements, redness and paleoflood records reconstructed from the Yellow River and its tributaries in northern China and historical documents in Weihe River. Furthermore, compared to late-Holocene, the frequency of great floods enhance substantially between 6200Cal yr BP and 4000Cal yr BP when Asian summer monsoon is strengthen. The incresed flood frequncy may be triggered by ENSO and rising of SST over West Pacific related to solar activity. In the paleoclimatic perspective, this paper point out that we should pay more attention to furture flood under the background of global warming

  12. Oak tree ring stable isotope records of late-summer and autumn temperature changes in the Eastern European lowlands

    NASA Astrophysics Data System (ADS)

    Nagavciuc, Viorica; Persoiu, Aurel; McCarroll, Danny; Loader, Neil J.; Popa, Ionel

    2017-04-01

    composition in earlywood during the last 115 years is 27.2 ‰ for δ18O and -23.4 ‰ for δ13C‰, and 28.9 ‰ for δ18O and -23.8‰ for δ13C for late wood, respectively. We observed a good correlation between the δ18OLW with δ18Oprec at BM and mean temperature during the summer season (June-July-August, JJA) and between δ18OEW with δ18Oprec and precipitation amount at BM during the previous year's autumn (September-October-November, SON). Based on the 115 years long chronology of isotopic composition and tree ring width, we found a high coefficient of correlation between δ18OEW, δ18OLW, δ13CEW δ13CLW and temp, pp amount, sunshine and cloud cover (coefficient of correlation varies between 0.42 and 0.63). Mean coefficient of correlation between TRW and t is -0.2 and 0.3 for precipitation. δ18OEW and δ13CEW are correlated with previous year's late autumn temp, and inversely correlated with previous year's autumn cloud cover (r = -0.54) and precipitation amount (r= -0.47). Also, we have found a good correlation of 0.4 with the winter, North Atlantic Oscillation index. δ18OLW and δ13CLW have a good correlation with late summer temperature and sunshine duration (r=0.63), and inverse correlation with late summer cloud cover (r=-0.56) and pp (r=-0.54). Stable isotopes in the earlywood of low altitude oak tree rings oak represent a good proxy indicator for cloud cover and precipitation amount from previous year's autumn and, stable isotopes in latewood represent a good proxy indicator for summer temperature and sunshine duration. We conclude that the stable isotopic composition of tree rings have considerable potential for paleoclimatic reconstruction even in areas such as lowland Romania, where climate does not strongly constrain tree growth and TRW has very limited potential for paleoclimatic reconstruction. Thanks to CLIMFOR 18SEE., PNII-RU-TE-2014-4-1993

  13. Recent ice cap snowmelt in Russian High Arctic and anti-correlation with late summer sea ice extent

    NASA Astrophysics Data System (ADS)

    Zhao, Meng; Ramage, Joan; Semmens, Kathryn; Obleitner, Friedrich

    2014-04-01

    Glacier surface melt dynamics throughout Novaya Zemlya (NovZ) and Severnaya Zemlya (SevZ) serve as a good indicator of ice mass ablation and regional climate change in the Russian High Arctic. Here we report trends of surface melt onset date (MOD) and total melt days (TMD) by combining multiple resolution-enhanced active and passive microwave satellite datasets and analyze the TMD correlations with local temperature and regional sea ice extent. The glacier surface snowpack on SevZ melted significantly earlier (-7.3 days/decade) from 1992 to 2012 and significantly longer (7.7 days/decade) from 1995 to 2011. NovZ experienced large interannual variability in MOD, but its annual mean TMD increased. The snowpack melt on NovZ is more sensitive to temperature fluctuations than SevZ in recent decades. After ruling out the regional temperature influence using partial correlation analysis, the TMD on both archipelagoes is statistically anti-correlated with regional late summer sea ice extent, linking land ice snowmelt dynamics to regional sea ice extent variations.

  14. Dark layers of the late Quaternary Japan Sea: Marine records of the East Asian summer monsoon fluctuation

    NASA Astrophysics Data System (ADS)

    Ikehara, K.; Usami, K.

    2009-12-01

    The late Quaternary sediments of the Japan Sea is characterized by the alternation of dark and light colored layers. Temporal occurrence of the dark layers has similar pattern with the Dansgaard-Oeschger cycle in the Greenland ice cores. It is considered that the dark layers were formed under the high primary productivity conditions related to enhanced inflow of nutrient-rich East China Sea surface water. We analyzed the sediment color with 0.2 mm intervals of a core collected from the central Japan Sea, and planktonic/benthic foraminiferal assemblages of another core from the southern Japan Sea. The results indicate the clear difference between the dark layers of MIS5 and of MIS 3-4. Higher productivity was expected for the former period but due to the relatively higher ventilation (lateral supply) of dissolved oxygen during the period, the dark layer formation occurred under the delicate balance between the oxygen consumption and supply. On the other hand, during MIS3-4, dark layer had sharp base and finely laminated, and low oxygen tolerant benthic foraminifera was dominant in the dark layer. This suggests that the dark layer formation was mainly controlled by not degradation at the sediment surface but the development of low-oxygen bottom water. The difference of the mechanism of dark layer formation was controlled by the global eustatic sea level changes and the East Asian summer monsoon fluctuation related to the mid-latitude insolation.

  15. Late-orogenic vertical movements within the arc of the SW Alps and Ligurian Alps

    NASA Astrophysics Data System (ADS)

    Bertotti, G.; Mosca, P.

    2009-09-01

    Mainly on the basis of seismic data, we reconstruct magnitude and timing of Miocene to Present vertical movements in the region of the Savigliano basin, an up to 4 km thick succession of Neogene to Quaternary sediments accumulated inside the Alpine arc at the western termination of the Po Plain. We focus, in particular, on the margins of the basin which are the link between the mountain range and the subsiding basin. Seismic data from these regions allow for the definition of upward and downward vertical movements (uplift-exhumation and subsidence) with a spatial and temporal resolution which cannot be attained by other methods. The eastern, southern and western margins of the Savigliano basin display very different geometries of the sedimentary bodies and, therefore, document different vertical movements during Miocene to Present times. The eastern part of the Savigliano basin, and the regions to the E, experienced subsidence followed by exhumation. The southern margin of the basin, in the Cuneo area, was much more stable with Miocene to present formations all pinching-out close to the present day outcropping position of the basement-sedimentary cover contact. In the W, seismic sections record a stage of tilting until the Burdigalian, followed by generalized subsidence which affected also the adjacent regions of the SW Alps. The overall pattern of vertical movements is essentially controlled by the NW-ward migration of a syncline-anticline couple with the synclinal axis presently located in the center of the Savigliano basin. The width of the folds is in the order of 30-60 km (1/2 wavelength). In map view, the trace of the fold axes changes from N-S in the Savigliano basin to E-W in the Alessandria basin.

  16. Coupling the Mars Dust and Water Cycles: Investigating the Role of Clouds in Controlling the Vertical Distribution of Dust During N. H. Summer

    NASA Technical Reports Server (NTRS)

    Kahre, M. A.; Haberle, R. M.; Hollingsworth, J. L.; Wilson, R. J.

    2014-01-01

    The dust cycle is critically important for the current climate of Mars. The radiative effects of dust impact the thermal and dynamical state of the atmosphere (Gierasch and Goody, 1968; Haberle et al., 1982; Zurek et al., 1992). Although dust is present in the Martian atmosphere throughout the year, the level of dustiness varies with season. The atmosphere is generally the dustiest during northern fall and winter and the least dusty during northern spring and summer (Smith, 2004). Dust particles are lifted into the atmosphere by dust storms that range in size from meters to thousands of kilometers across (Cantor et al., 2001). During some years, regional storms combine to produce hemispheric or planet encircling dust clouds that obscure the surface and raise atmospheric temperatures by as much as 40 K (Smith et al., 2002). Key recent observations of the vertical distribution of dust indicate that elevated layers of dust exist in the tropics and sub-tropics throughout much of the year (Heavens et al., 2011). These observations have brought particular focus on the processes that control the vertical distribution of dust in the Martian atmosphere. The goal of this work is to further our understanding of how clouds in particular control the vertical distribution of dust, particularly during N. H. spring and summer

  17. Late Cenozoic Vertical Motions of the Coachella Valley Using Apatite U-Th/He and 4/3He Thermochronometry

    NASA Astrophysics Data System (ADS)

    Mason, C. C.; Spotila, J. A.; Fame, M. L.; Dorsey, R. J.; Shuster, D. L.

    2015-12-01

    The Coachella Valley of southern California (USA) is a late Cenozoic transform-related sedimentary basin created by top-to-the-east extension on the West Salton detachment fault and dextral strike-slip offset on the San Andreas fault (Axen and Fletcher, 1998), which has continued to subside as a result of northeastward tilting since initiation of the San Jacinto fault ca. 1.2 Ma. Though it is generally agreed that these large regional faults are responsible for creation of high relief and deep subsidence in the Coachella Valley, the timing, magnitude, and geometries of fault offsets on these structures are still debated. This project applies an integrated source-to-sink approach to investigate tectonic models for evolution of the Pacific-North American plate boundary as recorded in the world-class natural laboratory of the Coachella Valley. In this study we integrate new thermochronometry-constrained kinematic models with tectonostratigraphic interpretations to help quantify the timing, rates, and magnitudes of tectonically driven vertical crustal motions and resulting mass fluxes. We sampled bedrock for U-Th/He (A-He) thermochronometry in the Mecca Hills, Santa Rosa, San Jacinto, and Little San Bernardino Mountains in both spatially focused and widely distributed areas. We also present new results from apatite 4/3He thermochronometry to help constrain the most recent exhumation histories. A-He results reveal spatially variable exhumation ages. The southwest Santa Rosa Mountains experienced late Miocene-early Pliocene exhumation along their southwest flank, while new A-He ages from ranges bounding Coachella Valley reveal complex uplift histories. We integrate our data set with previously published thermochronometric data to improve a regional synthesis of late Cenozoic vertical motions of the Coachella Valley.

  18. Climate inferences between paleontological, geochemical, and geophysical proxies in Late Pleistocene lacustrine sediments from Summer Lake, Oregon, western Great Basin

    NASA Astrophysics Data System (ADS)

    Heaton, Eric; Thompson, Greg; Negrini, Rob; Wigand, Peter

    2016-04-01

    Paleontological, geochemical, and geophysical data from western Great Basin pluvial Summer Lake, Oregon have established a high resolution paleoclimate record during the late Pleistocene Mono Lake Excursion (~34.75 ka), Dansgaard-Oeschger interstadials 6-8, and the end of Heinrich Even 4 (~38 ka). Proxies of grain-size, magnetic susceptibility, carbon/nitrogen ratio, ostracode analysis and palynology from a depocenter core show new results with improved age control regarding high amplitude, high frequency changes in lake level, lake temperature, and regional precipitation and temperature which correspond directly with colder/warmer and respectively drier/wetter climates as documented with Northern Atlantic Greenland ice core data. Results from geophysical and geochemical analysis, and the presence of ostracode Cytherissa lacustris consistently demonstrate the correspondence of low lake conditions and colder water temperatures during Dansgaard-Oeschger stadials and the Mono Lake Excursion. The opposite holds true during interstadials. Smaller grain size, increases in carbon/nitrogen ratio and consistent absence of C. lacustris suggest periods of increased discharge into the lake, increased lake level, and warmer water temperatures. Warmer/wetter climate conditions are confirmed during interstadials 7 and 8 from pollen analysis. Existence of Atriplex, Rosaceae, Chrysothamnus and Ambrosia, and pollen ratios of Juniperus/Dip Pinus and (Rosaceae+Atriplex+Poaceae+Chrysothamnus+Ambrosia)/(Pinus+Picea+T. mertensiana+Sarcobatus) suggest warmer/wetter semi-arid woodland conditions during interstadials 7 and 8. This contrasts with absences in these pollens and pollen ratios indicating colder/drier continental montane woodland conditions during stadials and the Mono Lake Excursion. Increases in Juniper/Dip Pinus ratio suggest a warmer/wetter climate during interstadial 6 however additional proxies do not demonstrate comparative warmer/wetter climate, deeper lake level or

  19. The Impact of Enhanced Summer Thaw, Hillslope Disturbances, and Late Season Rainfall on Solute Fluxes from High Arctic Headwater Catchments

    NASA Astrophysics Data System (ADS)

    Lafreniere, M. J.; Lamoureux, S. F.

    2011-12-01

    This study examines variations in the composition and total seasonal fluxes of dissolved solutes in several small High Arctic headwater catchments at the Cape Bounty Arctic Watershed Observatory (CBAWO), Melville Island, Nunavut (74°54'N, 109°35'W) over multiple snowmelt seasons (2007, 2008, 2009) with contrasting climate and permafrost active layer conditions. Climate warming in the High Arctic will affect a number processes that will alter the hydrological and biogeochemical exports from the landscape. Climate change is projected to alter precipitation regimes, resulting in increases in both winter and summer precipitation in the High Arctic, thereby altering hydrological regimes. Warming will result in thickening of the seasonal active layer, which will alter hydrological flow paths and water and solute sources. Additionally, active layer thickening and permafrost warming is also project to enhance the development of thermokarst features, including hillslope disturbances, such as active layer detachment slides and retrogressive thaw slumps. This research compares the flux of inorganic and organic solutes emanating from a group of catchments that were subject to a range hillslope disturbances, or active layer detachment slides (ALDs), at the end of summer 2007. One of the catchments, Goose, was not subject to any disturbance, while active layer slides covered between 6% and 46% of the catchment area in the disturbed catchments. It was hypothesised that solute fluxes would increase primarily with increasing extent and degree of disturbance. This however, was not observed. Rather, comparing five sites with varying degrees of disturbance in 2009 illustrates that on a specific area and specific volume of runoff basis, solute fluxes were unrelated to disturbance extent. Comparing two catchments that were monitored from 2007 (pre-disturbance) through to 2009 (2 yrs post disturbance), shows that both catchments were subject to solute flux increases, however the solute

  20. The late treatment of vertical orbital dystopia resulting from an orbital roof fracture.

    PubMed

    Horowitz, J H; Persing, J A; Winn, H R; Edgerton, M T

    1984-12-01

    Traumatic fracture of the orbital roof is uncommon and it may be unrecognized at the time of injury. In this article we describe a patient with progressive vertical orbital dystopia four years after he sustained a fracture of his "frontal" bone. Surgical exploration revealed an orbital roof fracture complicated by a chronic dural leak. An intracranial-extracranial approach through a modified frontal craniotomy provided excellent visualization to elevate the bony orbit and globe safely and repair the dural tear. Our study illustrates the need to correct residual soft tissue deformity at a second operation. Orbital roof fracture is a complex injury and is best treated by a multispecialty team using the methods learned from the treatment of patients with congenital orbital dystopia.

  1. Predicted Impacts of Conjunctive Water Management Scenarios on Late Summer Streamflow in an Agricultural Groundwater Basin with Limited Storage, Scott Valley, CA.

    NASA Astrophysics Data System (ADS)

    Tolley, D. G., III; Foglia, L.; Harter, T.

    2015-12-01

    Late summer streamflow for the Scott River in northern California has decreased approximately 50% since the mid 1960's, resulting in increased water temperatures and disconnection of the stream. This negatively impacts aquatic habitat of fish species such as coho and fall-run Chinook salmon. In collaboration with local stakeholders, the Scott Valley Integrated Hydrologic Model has been developed, which combines a water budget model and a groundwater-surface water model (MODFLOW) of the 200 km2 basin. The goal of the integrated model is to better understand the hydrologic system of the valley and explore effects of different conjunctive management scenarios on late summer streamflow. The groundwater model has a 100 m lateral resolution with aggregated monthly stresses over a 21 year simulation period (1990-2011). The Scott River and tributaries are represented using the streamflow routing (SFR) package. A sensitivity analysis and calibration were performed by hand using 812 head observations from 50 wells in the basin and average daily streamflow observations from a USGS stream gauge during the simulation period. The calibrated model was used to evaluate two different management scenarios: 1) in-lieu recharge where surface-water instead of groundwater is used to irrigate fields near the river while streamflow is sufficiently high, and 2) managed aquifer recharge during the winter months on agricultural fields located in gulches on the eastern side of the valley using existing infrastructure. Preliminary results indicate that implementation of conjunctive water management may increase late summer streamflow at the gauging station by 1-2 cubic feet per second (cfs), a significant amount given that flows are around 10-20 cfs during this time. This increase in flow during the late summer decreases the length of dry reaches both spatially and temporally, allowing for earlier reconnection of the Scott River and decreased stress on fish.

  2. Descriptions of the Animas River-Cement Creek Confluence and Mixing Zone Near Silverton, Colorado, During the Late Summers of 1996-1997

    DTIC Science & Technology

    2005-01-01

    Descriptions of the Animas River-Cement Creek Confluence and Mixing Zone near Silverton , Colorado, during the Late Summers of 1996 and 1997 U.S...circum-neutral Animas River in a high-elevation region of the San Juan Mountains near Silverton , Colorado. Cement Creek is acidic and enriched in metals...Animas River drains an extensively mineralized caldera in the San Juan Mountains near Silverton , Colorado (Yager and Bove, 2002). This is an area of

  3. Dike orientations in the late jurassic independence dike swarm and implications for vertical-axis tectonic rotations in eastern California

    USGS Publications Warehouse

    Hopson, R.F.; Hillhouse, J.W.; Howard, K.A.

    2008-01-01

    Analysis of the strikes of 3841 dikes in 47 domains in the 500-km-long Late Jurassic Independence dike swarm indicates a distribution that is skewed clockwise from the dominant northwest strike. Independence dike swarm azimuths tend to cluster near 325?? ?? 30??, consistent with initial subparallel intrusion along much of the swarm. Dike azimuths in a quarter of the domains vary widely from the dominant trend. In domains in the essentially unrotated Sierra Nevada block, mean dike azimuths range mostly between 300?? and 320??, with the exception of Mount Goddard (247??). Mean dike azimuths in domains in the Basin and Range Province in the Argus, Inyo, and White Mountains areas range from 291?? to 354?? the mean is 004?? in the El Paso Mountains. In the Mojave Desert, mean dike azimuths range from 318?? to 023??, and in the eastern Transverse Ranges, they range from 316?? to 051??. Restoration for late Cenozoic vertical-axis rotations, suggested by paleodeclinations determined from published studies from nearby Miocene and younger rocks, shifts dike azimuths into better agreement with azimuths measured in the tectonically stable Sierra Nevada. This confirms that vertical-axis tectonic rotations explain some of the dispersion in orientation, especially in the Mojave Desert and eastern Transverse Ranges, and that the dike orientations can be a useful if imperfect guide to tectonic rotations where paleomagnetic data do not exist. Large deviations from the main trend of the swarm may reflect (1) clockwise rotations for which there is no paleomagnetic evidence available, (2) dike intrusions of other ages, (3) crack filling at angles oblique or perpendicular to the main swarm, (4) pre-Miocene rotations, or (5) unrecognized domain boundaries between dike localities and sites with paleomagnetic determinations. ?? 2008 The Geological Society of America.

  4. Unexpected consequences of a drier world: evidence that delay in late summer rains biases the population sex ratio of an insect.

    PubMed

    Bonal, Raul; Hernández, Marisa; Espelta, Josep M; Muñoz, Alberto; Aparicio, José M

    2015-09-01

    The complexity of animal life histories makes it difficult to predict the consequences of climate change on their populations. In this paper, we show, for the first time, that longer summer drought episodes, such as those predicted for the dry Mediterranean region under climate change, may bias insect population sex ratio. Many Mediterranean organisms, like the weevil Curculio elephas, become active again after summer drought. This insect depends on late summer rainfall to soften the soil and allow adult emergence from their underground refuges. We found that, as in many protandric species, more C. elephas females emerged later in the season. Male emergence timing was on average earlier and also more dependent on the beginning of late summer rainfall. When these rains were delayed, the observed weevil sex ratio was biased towards females. So far, the effects of global warming on animal sex ratios has been reported for temperature-dependent sex determination in reptiles. Our results show that rainfall timing can also bias the sex ratio in an insect, and highlight the need for keeping a phenological perspective to predict the consequences of climate change. We must consider not just the magnitude of the predicted changes in temperature and rainfall but also the effects of their timing.

  5. Unexpected consequences of a drier world: evidence that delay in late summer rains biases the population sex ratio of an insect

    PubMed Central

    Bonal, Raul; Hernández, Marisa; Espelta, Josep M.; Muñoz, Alberto; Aparicio, José M.

    2015-01-01

    The complexity of animal life histories makes it difficult to predict the consequences of climate change on their populations. In this paper, we show, for the first time, that longer summer drought episodes, such as those predicted for the dry Mediterranean region under climate change, may bias insect population sex ratio. Many Mediterranean organisms, like the weevil Curculio elephas, become active again after summer drought. This insect depends on late summer rainfall to soften the soil and allow adult emergence from their underground refuges. We found that, as in many protandric species, more C. elephas females emerged later in the season. Male emergence timing was on average earlier and also more dependent on the beginning of late summer rainfall. When these rains were delayed, the observed weevil sex ratio was biased towards females. So far, the effects of global warming on animal sex ratios has been reported for temperature-dependent sex determination in reptiles. Our results show that rainfall timing can also bias the sex ratio in an insect, and highlight the need for keeping a phenological perspective to predict the consequences of climate change. We must consider not just the magnitude of the predicted changes in temperature and rainfall but also the effects of their timing. PMID:26473046

  6. The extent of ocean acidification on aragonite saturation state along the Washington-Oregon continental shelf margin in late summer 2012

    NASA Astrophysics Data System (ADS)

    Feely, R. A.; Alin, S. R.; Hales, B. R.; Juranek, L.; Greeley, D.

    2012-12-01

    The Washington-Oregon continental shelf region is exposed to conditions of low aragonite saturation state during the late spring/early summer upwelling season. However, the extent of its evolution in late summer/early fall has been largely unknown. Along this continental margin, ocean acidification, upwelling, biological productivity, and respiration processes in subsurface waters are major contributors to the variability in dissolved inorganic carbon (DIC), pH and aragonite saturation state. The persistence of water with aragonite saturation state <1 on the continental shelf off Washington and Oregon has been previously identified and could have profound ecological consequences for benthic and pelagic calcifying organisms such as mussels, oysters, abalone, echinoderms, and pteropods. In the late summer of 2012 we studied the extent of acidification conditions employing shipboard cruises and profiling gliders. We conducted several large-scale chemical and hydrographic surveys of the region in order to better understand the interrelationships between these natural and human-induced processes and their effects on aragonite saturation. We will compare the results of these new surveys with our previous work in 2011 and 2007.

  7. Observations of atmospheric pollutants vertical distribution in Shanghai during summer using MAX-DOAS and Lidar measurements

    NASA Astrophysics Data System (ADS)

    Xing, Chengzhi; Liu, Cheng; Wang, Shanshan; Chan, Ka Lok; Hu, Qihou; Dong, Yunsheng; Fan, Guangqiang; Su, Wenjing; Zhang, Tianshu; Liu, Jianguo

    2017-04-01

    Ground based Multi-axis differential optical absorption spectroscopy (MAX-DOAS) measurements have been performed during Shanghai (N30.8, E121.5) campaign, China, in May 2016. In this study, vertical profiles of aerosol extinction coefficient, NO2 and HCHO concentration were retrieved using Heidelberg Profile algorithm. The O3 profiles were detected by Lidar. For the aerosol profiles result, we found the a priori profile play an important role in the retrieval. The aerosol profile was improved when a Gaussian priori was used in the retrieval. And it show a good correlation with the profile measured by the Mie-Scattering Polarization Lidar. There is also a good correlation between retrieved NO2 VCDs and OMI data. In addition, the ozone vertical profiles changed obviously and have different characteristic during the campaign. And the ozone new production not only occurred near surface ground but also at the higher altitude (about 1.3km). In order to determine the production of ozone, the horizontal and vertical wind field, PBL (plant boundary layer) were analyzed. We found that the high ozone concentration at ground and 1.3 km is not dominant by the horizontal and vertical transport of ozone itself. Compared to the retrieved NO2 and HCHO profiles, a similar trend between O3 and HCHO was observed. As a consequence, a meaningful conclusion can be reached. The PO3 (the production of ozone) in the near surface ground and high altitude is a VOC-limited condition.

  8. Clay mineralogical and geochemical proxies of the East Asian summer monsoon evolution in the South China Sea during Late Quaternary

    PubMed Central

    Chen, Quan; Liu, Zhifei; Kissel, Catherine

    2017-01-01

    The East Asian summer monsoon controls the climatic regime of an extended region through temperature and precipitation changes. As the East Asian summer monsoon is primarily driven by the northern hemisphere summer insolation, such meteorological variables are expected to significantly change on the orbital timescale, influencing the composition of terrestrial sediments in terms of both mineralogy and geochemistry. Here we present clay mineralogy and major element composition of Core MD12-3432 retrieved from the northern South China Sea, and we investigate their relationship with the East Asian summer monsoon evolution over the last 400 ka. The variability of smectite/(illite + chlorite) ratio presents a predominant precession periodicity, synchronous with the northern hemisphere summer insolation changes and therefore with that of the East Asian summer monsoon. Variations in K2O/Al2O3 are characterized by eccentricity cycles, increasing during interglacials when the East Asian summer monsoon is enhanced. Based on the knowledge of sediment provenances, we suggest that these two proxies in the South China Sea are linked to the East Asian summer monsoon evolution with different mechanisms, which are (1) contemporaneous chemical weathering intensity in Luzon for smectite/(illite + chlorite) ratio and (2) river denudation intensity for K2O/Al2O3 ratio of bulk sediment. PMID:28176842

  9. Clay mineralogical and geochemical proxies of the East Asian summer monsoon evolution in the South China Sea during Late Quaternary

    NASA Astrophysics Data System (ADS)

    Chen, Quan; Liu, Zhifei; Kissel, Catherine

    2017-02-01

    The East Asian summer monsoon controls the climatic regime of an extended region through temperature and precipitation changes. As the East Asian summer monsoon is primarily driven by the northern hemisphere summer insolation, such meteorological variables are expected to significantly change on the orbital timescale, influencing the composition of terrestrial sediments in terms of both mineralogy and geochemistry. Here we present clay mineralogy and major element composition of Core MD12-3432 retrieved from the northern South China Sea, and we investigate their relationship with the East Asian summer monsoon evolution over the last 400 ka. The variability of smectite/(illite + chlorite) ratio presents a predominant precession periodicity, synchronous with the northern hemisphere summer insolation changes and therefore with that of the East Asian summer monsoon. Variations in K2O/Al2O3 are characterized by eccentricity cycles, increasing during interglacials when the East Asian summer monsoon is enhanced. Based on the knowledge of sediment provenances, we suggest that these two proxies in the South China Sea are linked to the East Asian summer monsoon evolution with different mechanisms, which are (1) contemporaneous chemical weathering intensity in Luzon for smectite/(illite + chlorite) ratio and (2) river denudation intensity for K2O/Al2O3 ratio of bulk sediment.

  10. Clay mineralogical and geochemical proxies of the East Asian summer monsoon evolution in the South China Sea during Late Quaternary.

    PubMed

    Chen, Quan; Liu, Zhifei; Kissel, Catherine

    2017-02-08

    The East Asian summer monsoon controls the climatic regime of an extended region through temperature and precipitation changes. As the East Asian summer monsoon is primarily driven by the northern hemisphere summer insolation, such meteorological variables are expected to significantly change on the orbital timescale, influencing the composition of terrestrial sediments in terms of both mineralogy and geochemistry. Here we present clay mineralogy and major element composition of Core MD12-3432 retrieved from the northern South China Sea, and we investigate their relationship with the East Asian summer monsoon evolution over the last 400 ka. The variability of smectite/(illite + chlorite) ratio presents a predominant precession periodicity, synchronous with the northern hemisphere summer insolation changes and therefore with that of the East Asian summer monsoon. Variations in K2O/Al2O3 are characterized by eccentricity cycles, increasing during interglacials when the East Asian summer monsoon is enhanced. Based on the knowledge of sediment provenances, we suggest that these two proxies in the South China Sea are linked to the East Asian summer monsoon evolution with different mechanisms, which are (1) contemporaneous chemical weathering intensity in Luzon for smectite/(illite + chlorite) ratio and (2) river denudation intensity for K2O/Al2O3 ratio of bulk sediment.

  11. Effects of the Pearl River plume on the vertical structure of coastal currents in the Northern South China Sea during summer 2008

    NASA Astrophysics Data System (ADS)

    Shu, Yeqiang; Chen, Ju; Yao, Jinglong; Pan, Jiayi; Wang, Weiwen; Mao, Huabin; Wang, Dongxiao

    2014-12-01

    Analyses of moored current meter data from the South China Sea (SCS) Coastal Oceanographic Process Experiment Pilot Project (SCOPE-PP) reveal that strong spatial variation in the vertical structure of coastal currents in the northern SCS (NSCS) was caused by the interaction between the Pearl River plume (PRP) and the alongshore coastal jet. Observations indicate that the NSCS coastal current was generally eastward, spreading the PRP water eastward. The lighter brackish plume residing on the top of the saline, coastal water strengthened the stratification near the surface and blocked the downward momentum transport, resulting in a strong vertical shear of the velocity at the mooring site S205. Meanwhile, the plume water raised the sea level. Because of the geostrophic balance in the across-shore direction, the eastward coastal current in the upper layer strengthened on the onshore side (near S205) and weakened on the offshore side (near S206 and S305) due to the plume water intrusion. Therefore, the vertical shear of the velocity was enhanced at S205 and reduced at S206 and S305. Moreover, because the plume varied substantially with the wind, the vertical shear of the velocity responding to the wind was different between S205 and S206. The numerical simulation during summer 2008 confirms that the PRP enhances (weakens) the vertical shear of the velocity on the onshore (offshore) side by increasing (decreasing) the upper-layer current by about 0.2 m s-1 and decreasing (increasing) the middle-layer current slightly.

  12. Enhanced solar activity influence on the summer temperature variability of the southeast margin of the Qinghai-Tibetan Plateau in the late Holocene

    NASA Astrophysics Data System (ADS)

    Chang, Jie; Zhang, Enlou; Liu, Enfeng; Shulmeister, James

    2017-04-01

    We present two quantitative chironomid-based Holocene summer temperature records from the southeast margin of the Qinghai-Tibetan Plateau (QTP). The records are from two alpine lakes (Tiancai and Heihai) located at the elevation of close to 4000 m above sea level from Yunnan Province. The mean July temperatures were quantified by applying a transfer function model (r2 = 0.63, RMSEP = 2.3 °C) developed based on a 100-lake modern calibration dataset of south-west China. The results were validated using standard reconstruction diagnostics. Both records show that the total summer temperature variation is within 2.5 °C. The records also show that the overall pattern broadly matches the declining trend of the summer insolation at 30°N and the Asian Summer Monsoon records. The general declining trend is punctuated by a few warm and cool intervals on the centennial scale. We observed a periodicity pattern in the mean July temperature variability and these fluctuations are possibly related to both the solar irradiance and the summer monsoon changes. Solar activity may have played an enhanced role on the highland summer temperature changes in the late Holocene when the monsoon influence to south-western China is generally weakened. More comprehensive investigations are needed to clarify the relationship between solar activity, the East Asian and Indian Ocean summer monsoons and the response of alpine climate in order to disentangle these or the combined effects on the climate change in the broad region of south-western China.

  13. Paleolatitudinal changes in vertical facies transitions recording late Paleozoic glaciations: a case study from eastern Australia

    NASA Astrophysics Data System (ADS)

    Fielding, C. R.; Frank, T. D.; Shultis, A. I.

    2011-12-01

    Stratigraphic records of the complex and multi-phase late Paleozoic Ice Age (LPIA) have been examined over a 2000 km paleo-polar to paleo-mid latitude transect from Tasmania to Queensland, eastern Australia. In this presentation, we summarize changes in facies assemblages within glacial and nonglacial epochs and the transitions between them, within the coastal to shallow marine Permian succession. In the earliest Permian P1 glacial interval, facies represent proximal proglacial to locally glacial environments in Tasmania (TAS), and an array of mainly marine proglacial to glacimarine environments in New South Wales (NSW) and Queensland (QLD). A trend of more ice-proximal to less ice-proximal facies assemblages is evident from south to north. The end of P1 is represented both by abrupt flooding trends in some areas and by thicker intervals of more gradually fining-upward facies recording progressive deepening elsewhere. The onset of the Sakmarian/Artinskian P2 glacial interval is best-exposed in southern NSW, where an abrupt change to marine proglacial facies is accompanied by evidence for deepening, suggesting isostatic loading of the sedimentary surface. P2 glacial facies are more proximal in NSW than in QLD. Both P1 and P2 intervals preserve complex internal stratigraphy, in many cases recording multiple glacial-interglacial cycles. The close of P2 is again recorded in a variety of ways, with many sections showing a gradual fining-upward and decrease in indicators of glacial conditions. The Kungurian to Capitanian P3 and P4 glacial intervals are in general represented by less proximal facies than their predecessors, typically intervals of outsize clast-bearing mudrocks and sandstones. These in many areas show diffuse boundaries with the nonglacial facies that enclose them. Furthermore, no significant paleolatitudinal changes in the P3 and P4 facies assemblages are evident from TAS to QLD. The documented patterns support the view that the P1 glacial represents the

  14. Radiative energy budget estimates for the 1979 southwest summer monsoon

    NASA Technical Reports Server (NTRS)

    Ackerman, Steven A.; Cox, Stephen K.

    1987-01-01

    A major objective of the summer monsoon experiment (SMONEX) was the determination of the heat sources and sinks associated with the southwest summer monsoon. The radiative component is presented here. The vertically integrated tropospheric radiation energy budget is negative and varies significantly as a function of monsoon activity. The gradient in the latitudinal mean tropospheric cooling reverses between the winter periods and the late spring/early summer periods. The radiative component of the vertical profile of the diabatic heating is derived. These profiles are a strong function of the stage of the monsoon as well as the geographic region. In general, the surface experiences a net gain of radiative energy during the late spring and early summer periods. During the winter periods, areas northward of 25 N display net surface losses, while the remaining areas exhibit net gains.

  15. Comparison of aerosol optical properties at the sub-arctic stations ALOMAR-Andenes, Abisko and Sodankylä in late spring and summer 2007

    NASA Astrophysics Data System (ADS)

    Rodríguez, E.; Toledano, C.; Cachorro, V.; de Leeuw, G.; De Frutos, A.; Gausa, M.; Holben, B.

    2012-04-01

    Aerosol concentration and aerosol type, retrieved from observations with CIMEL sun-photometers at three sub-arctic locations at the Scandinavian Peninsula are presented. The observations were made at ALOMAR-Andenes in Norway, Abisko in Sweden and Sodankylä in Finland. This field campaign took place in late spring and summer 2007 as part of the activities of the International Polar Year (IPY) within the POLARCAT project at ALOMAR and Abisko. Aerosol properties were characterized using the relationship between the aerosol optical depth and the Ångström Exponent. The characteristics of the predominant aerosol type and microphysics are largely determined by the location of the site (continental or coastal). During summer the fine mode particles dominate, as indicated by the fine mode volume fraction and the Ångström Exponent. The aerosol concentration was on average very low, except during an event in which long-range transported aerosols (dust and pollution) were detected.

  16. The vertical structure of ozone and water vapor profiles in Lhasa within Asia summer monsoon anticyclone during the stratospheric intrusion

    NASA Astrophysics Data System (ADS)

    Li, Dan; Vogel, Bärbel; Bian, Jianchun; Müller, Rolf; Günther, Gebhard; Bai, Zhixuan; Li, Qian; Fan, Qiujun; Zhang, Jinqiang

    2017-04-01

    A stratospheric intrusion process occurred over the southeastern side of the Asia summer monsoon (ASM) region is investigated using the balloon-borne measurements of ozone and water vapor during 18-20 August 2013. Data from Lhasa (29.66° N, 91.14° E, above sea level (asl.) 3,650 m) show that the positive relative change of the ozone mixing ratios in the tropopause layer attained to 90 % on 19 and 20 August. The backward trajectory calculation from CLaMS model and the satellite data from the ozone monitoring instrument (OMI) and the atmospheric infrared sounder (AIRS) indicate that the (stratospheric) air parcels intruded (originated) from the Northeast Asia to the southeastern edge of the ASM anticyclone. Meanwhile, typhoon Utor occurred over the sourtheastern edge of the ASM and lasted from 8 to 18 August 2013. The convection associated with Utor uplifted air with low ozone from the Western Pacific to the middle/upper troposphere. Air parcels with high ozone from the high latitude and with low ozone from the Western Pacific met at the sourtheastern side of the ASM and then transported westward to Lhasa over long-distances (˜2,000 km). In addition, the laminated identification method is used to identify the laminae structure of the ozone and water vapor profiles from the middle troposphere to the lower stratosphere in Lhasa, confirming the role of the dynamic disturbance (e.g., Rossby and gravity wave)

  17. Differential response of planktonic primary, bacterial, and dimethylsulfide production rates to vertically-moving and static incubations in upper mixed-layer summer sea waters

    NASA Astrophysics Data System (ADS)

    Galí, M.; Simó, R.; Pérez, G. L.; Ruiz-González, C.; Sarmento, H.; Royer, S.-J.; Fuentes-Lema, A.; Gasol, J. M.

    2013-05-01

    Microbial plankton experience fluctuations in total solar irradiance and in its spectral composition as they are vertically moved by turbulence in the oceanic upper mixed layer (UML). The fact that the light exposure is not static but dynamic may have important consequences for biogeochemical processes and ocean-atmosphere fluxes. However, most biogeochemical processes other than primary production, like bacterial production or dimethylsulfide (DMS) production, are seldom measured in sunlight and even less often in dynamic light fields. We conducted four experiments in oligotrophic summer stratified Mediterranean waters, where a sample from the UML was incubated in ultraviolet (UV)-transparent bottles at three fixed depths within the UML and on a vertically-moving basket across the same depth range. We assessed the response of the phyto- and bacterioplankton community with physiological indicators based on flow cytometry singe-cell measurements, Fast Repetition Rate fluorometry (FRRf), phytoplankton pigment concentrations and particulate light absorption. Dynamic light exposure caused a disruption of the photoinhibition and photoacclimation processes associated to ultraviolet radiation (UVR), which slightly alleviated bacterial photoinhibition but did not favor primary production. Gross DMS production (GPDMS) decreased sharply with depth in parallel to shortwave UVR, and displayed a dose-dependent response that mixing did not significantly disrupt. To our knowledge, we provide the first measurements of GPDMS under in situ UV-inclusive optical conditions.

  18. Vertical structure of cumulonimbus towers and intense convective clouds over the South Asian region during the summer monsoon season

    NASA Astrophysics Data System (ADS)

    Bhat, G. S.; Kumar, Shailendra

    2015-03-01

    The vertical structure of radar reflectivity factor in active convective clouds that form during the South Asian monsoon season is reported using the 2A25 version 6 data product derived from the precipitation radar measurements on board the Tropical Rainfall Measuring Mission satellite. We define two types of convective cells, namely, cumulonimbus towers (CbTs) and intense convective cells (ICCs). CbT is defined referring to a reflectivity threshold of 20 dBZ at 12 km altitude and is at least 9 km thick. ICCs are constructed referring to reflectivity thresholds at 8 km and 3 km altitudes. Cloud properties reported here are based on 10 year climatology. It is observed that the frequency of occurrence of CbTs is highest over the foothills of Himalayas, plains of northern India and Bangladesh, and minimum over the Arabian Sea and equatorial Indian Ocean west of 90°E. The regional differences depend on the reference height selected, namely, small in the case of CbTs and prominent in 6-13 km height range for ICCs. Land cells are more intense than the oceanic ones for convective cells defined using the reflectivity threshold at 3 km, whereas land versus ocean contrasts are not observed in the case of CbTs. Compared to cumulonimbus clouds elsewhere in the tropics, the South Asian counterparts have higher reflectivity values above 11 km altitude.

  19. Inferences about winter temperatures and summer rains from the late Quaternary record of C4 perennial grasses and C3 desert shrubs in the northern Chihuahuan Desert

    NASA Astrophysics Data System (ADS)

    Holmgren, Camille A.; Norris, Jodi; Betancourt, Julio L.

    2007-02-01

    Late Quaternary histories of two North American desert biomes - C4 grasslands and C3 shrublands - are poorly known despite their sensitivity and potential value in reconstructing summer rains and winter temperatures. Plant macrofossil assemblages from packrat midden series in the northern Chihuahuan Desert show that C4 grasses and annuals typical of desert grassland persisted near their present northern limits throughout the last glacial-interglacial cycle. By contrast, key C3 desert shrubs appeared somewhat abruptly after 5000 cal. yr BP. Bioclimatic envelopes for select C4 and C3 species are mapped to interpret the glacial-interglacial persistence of desert grassland and the mid-to-late Holocene expansion of desert shrublands. The envelopes suggest relatively warm Pleistocene temperatures with moist summers allowed for persistence of C4 grasses, whereas winters were probably too cold (or too wet) for C3 desert shrubs. Contrary to climate model results, core processes associated with the North American Monsoon and moisture transport to the northern Chihuahuan Desert remained intact throughout the last glacial-interglacial cycle. Mid-latitude effects, however, truncated midsummer (July-August) moisture transport north of 35° N. The sudden expansion of desert shrublands after 5000 cal. yr BP may be a threshold response to warmer winters associated with increasing boreal winter insolation, and enhanced El Niño-Southern Oscillation variability. Published in 2006 by John Wiley & Sons, Ltd.

  20. Inferences about winter temperatures and summer rains from the late Quaternary record of C4 perennial grasses and C3 desert shrubs in the northern Chihuahuan Desert

    USGS Publications Warehouse

    Holmgren, Camille A.; Norris, Jodi; Betancourt, Julio L.

    2007-01-01

    Late Quaternary histories of two North American desert biomes—C4 grasslands and C3 shrublands—are poorly known despite their sensitivity and potential value in reconstructing summer rains and winter temperatures. Plant macrofossil assemblages from packrat midden series in the northern Chihuahuan Desert show that C4 grasses and annuals typical of desert grassland persisted near their present northern limits throughout the last glacial-interglacial cycle. By contrast, key C3 desert shrubs appeared somewhat abruptly after 5000cal.yrBP. Bioclimatic envelopes for select C4 and C3 species are mapped to interpret the glacial-interglacial persistence of desert grassland and the mid-to-late Holocene expansion of desert shrublands. The envelopes suggest relatively warm Pleistocene temperatures with moist summers allowed for persistence of C4 grasses, whereas winters were probably too cold (or too wet) for C3 desert shrubs. Contrary to climate model results, core processes associated with the North American Monsoon and moisture transport to the northern Chihuahuan Desert remained intact throughout the last glacial-interglacial cycle. Mid-latitude effects, however, truncated midsummer (July-August) moisture transport north of 35° N. The sudden expansion of desert shrublands after 5000cal.yrBP may be a threshold response to warmer winters associated with increasing boreal winter insolation, and enhanced El Niño-Southern Oscillation variability.

  1. Transport of trace metals (Mn, Fe, Ni, Zn and Cd) in the western Arctic Ocean (Chukchi Sea and Canada Basin) in late summer 2012

    NASA Astrophysics Data System (ADS)

    Kondo, Yoshiko; Obata, Hajime.; Hioki, Nanako; Ooki, Atsushi; Nishino, Shigeto; Kikuchi, Takashi; Kuma, Kenshi

    2016-10-01

    through scavenging processes. Based on the phase distributions of Fe and Mn, which were calculated as ratios between the LP and D fractions, different behaviors between Fe and Mn were expressed during lateral transportation. The concentration of TD-Fe declined rapidly via removal of LP-Fe from the water column, whereas the concentration of TD-Mn declined more slowly through the transformation of D-Mn into LP-Mn. In contrast, the concentrations of D-Cd, D-Zn and D-Ni were more strongly correlated with phosphate levels, which suggest that, like phosphate, the distributions of Cd, Zn and Ni were generally controlled by the internal biogeochemical cycles of the ocean interior. Based on the findings of studies that have previously evaluated the concentration maxima of Ni, Zn and Cd within the halocline layer in the Canada Basin near the Canadian Arctic Archipelago, the elevated Ni, Zn and Cd concentrations in the halocline layer may extend across the Canada Basin from the Chukchi Sea shelf-break area. The determination coefficients for correlations with phosphate concentration varied between the concentrations of Ni, Zn and Cd, which suggest that the sources of these trace metals, such as sediments and sea-ice melting, affected their patterns of distributions differently. Our findings reveal the importance and impact of the halocline layer for the transport of trace metals in the western Arctic Ocean during the late summer. The existence of rich and various sources likely sustained the high concentrations of trace metals and their unique profiles in this region.

  2. Booktalking: Avoiding Summer Drift

    ERIC Educational Resources Information Center

    Whittingham, Jeff; Rickman, Wendy A.

    2015-01-01

    Summer drift, otherwise known as loss of reading comprehension skills or reading achievement, has been a well-known and well-documented phenomenon of public education for decades. Studies from the late twentieth century to the present have demonstrated a slowdown in summer drift attributed to specific summer reading programs addressing motivation…

  3. Late Pleistocene C4 plant dominance and summer rainfall in the southwestern United States from isotopic study of herbivore teeth

    USGS Publications Warehouse

    Connin, S.L.; Betancourt, J.; Quade, Jay

    1998-01-01

    Patterns of climate and C4 plant abundance in the southwestern United States during the last glaciation were evaluated from isotopic study of herbivore tooth enamel. Enamel ??13C values revealed a substantial eastward increase in C4 plant consumption for Mammuthus spp., Bison spp., Equus spp., and Camelops spp. The ??13C values were greatest in Bison spp. (-6.9 to + 1.7???) and Mammuthus spp. (-9.0 to +0.3???), and in some locales indicated C4-dominated grazing. The ??13C values of Antilocaprids were lowest among taxa (-12.5 to -7.9???) and indicated C3 feeding at all sites. On the basis of modern correlations between climate and C4 grass abundance, the enamel data imply significant summer rain in parts of southern Arizona and New Mexico throughout the last glaciation. Enamel ??18O values range from +19.0 to +31.0??? and generally increase to the east. This pattern could point to a tropical or subtropical source of summer rainfall. At a synoptic scale, the isotope data indicate that interactions of seasonal moisture, temperature, and lowered atmospheric pCO2 determined glacial-age C4 abundance patterns.

  4. A comparison between late summer 2012 and 2013 water masses, macronutrients, and phytoplankton standing crops in the northern Bering and Chukchi Seas

    NASA Astrophysics Data System (ADS)

    Danielson, Seth L.; Eisner, Lisa; Ladd, Carol; Mordy, Calvin; Sousa, Leandra; Weingartner, Thomas J.

    2017-01-01

    Survey data from the northern Bering and Chukchi sea continental shelves in August-September 2012 and 2013 reveal inter-annual differences in the spatial structure of water masses along with statistically significant differences in thermohaline properties, chemical properties, and phytoplankton communities. We provide a set of water mass definitions applicable to the northern Bering and Chukchi continental shelves, and we find that the near-bottom Bering-Chukchi Summer Water (BCSW) was more saline in 2012 and Alaskan Coastal Water (ACW) was warmer in 2013. Both of these water masses carried higher nutrient concentrations in 2012, supporting a larger chlorophyll a biomass that was comprised primarily of small (<10 μm) size class phytoplankton, so the classical relation between higher nutrient loads and larger phytoplankton does not hold for this region in late summer. The distributions of phytoplankton biomass and size structure reveal linkages between the wind fields, seafloor topography, water mass distributions and the pelagic production. The water mass structure, including the strength and location of stratification and fronts, respectively, differed primarily because of the August regional wind field, which was more energetic in 2012 but was more persistent in direction in 2013. High concentrations of ice in winter and early spring in 2012 and 2013 resembled conditions of the 1980s and early 1990s but the regional ice retreat rate has accelerated in the late 1990s and 2000s so the summer and fall ice concentrations more closely resembled those of the last two decades. Our data show that wind forcing can shut down the Alaskan Coastal Current in the NE Chukchi Sea for periods of weeks to months during the ice-covered winter and during the summer when buoyancy forcing is at its annual maximum. We hypothesize that a decrease in salinity and nutrients from 2012 to 2013 was a consequence of a decreased net Bering Strait transport from 2011 to 2012. Biological

  5. Temporal variations of the microwave signatures of sea ice during the late spring and early summer near Mould Bay, NWT

    NASA Technical Reports Server (NTRS)

    Grenfell, T. C.; Lohanick, A. W.

    1985-01-01

    It has been shown that passive microwave imagery obtained from satellite-borne sensors provides an important basis for the study of the polar regions. Because of the optical thinness of high-latitude clouds at microwave frequencies, radiometry can provide all-weather all-time observing capability. However, in order to clarify observational uncertainties and investigate the information content of passive microwave imagery, detailed ground-based observations are needed. Multifrequency data are also required to utilize the strong spectral dependence of both the dielectric properties of liquid water and volume scattering. The present investigation has the aim to provide information of the considered type for the calibration and interpretation of satellite observations of the Arctic during the summer season. Attention is given to instruments and calibration, the field program and the state of the ice cover, and the results.

  6. Establishment of the South Asian high over the Indo-China Peninsula during late spring to summer

    NASA Astrophysics Data System (ADS)

    Wang, Lijuan; Dai, Aiguo; Guo, Shuaihong; Ge, Jing

    2017-02-01

    The establishment of the upper-level South Asian high (SAH) over the Indo-China Peninsula (ICP) during late boreal spring and its possible causes are investigated using long-term NCEP-NCAR and ERA-40 reanalysis and satellite-observed OLR data. Results show that, from early March to mid-April, deep convection stays south of 6°N over the northern Sumatran islands. As the maximum solar radiation moves over the latitudes of the ICP (10°-20°N) in late April, the air over the ICP becomes unstable. It ascends over the ICP and descends over the adjacent waters to the east and west. This triggers deep convection over the ICP that induces large latent heating and strong updrafts and upper-level divergence, leading to the formation of an upper-level anticyclonic circulation and the SAH over the ICP. During early to mid-May, deep convection over the ICP intensifies and extends northwards to the adjacent waters. Strong latent heating from deep convection enhances and maintains the strong updrafts and upper-level divergence, and the SAH is fully established by mid-May. Thus, the seasonal maximum solar heating and the land-sea contrast around the ICP provide the basic conditions for deep convection to occur preferentially over the ICP, which leads to the formation of the SAH over the ICP from late April to mid-May. Simulations using RegCM4 also indicate that the diabatic heating over the ICP is conducive to the generation and development of upperlevel anticyclonic circulation, which leads to an earlier establishment of the SAH.

  7. Descriptions of the Animas River-Cement Creek confluence and mixing zone near Silverton, Colorado, during the late summers of 1996 and 1997

    USGS Publications Warehouse

    Schemel, Laurence E.; Cox, Marisa H.

    2005-01-01

    Acidic waters from Cement Creek discharge into the circum-neutral Animas River in a high-elevation region of the San Juan Mountains near Silverton, Colorado. Cement Creek is acidic and enriched in metals and sulfate because it is fed by discharges from abandoned mines and natural mineral deposits. Mixing with the Animas River raises the pH and produces precipitates of iron and aluminum (oxy)hydroxides, which in turn can adsorb other metals. This confluence was studied in 1996 and 1997 to better understand mixing and sorption processes which are common during the neutralization of acidic streams. The photographs in this report show flow braiding and other features that influenced the way the two streams mixed during the late summers of the two years. They also show 'banding' due to incomplete mixing and 'opalescence' due to chemical reactions and the formation of colloidal-size particles in the mixing zone.

  8. Abundance, biomass, vertical migration and estimated development rate of the copepod Calanus finmarchicus in the southern Gulf of Maine during late spring

    NASA Astrophysics Data System (ADS)

    Durbin, Edward G.; Gilman, Sharon L.; Campbell, Robert G.; Durbin, Ann G.

    Abundance, biomass, diel vertical migration and estimated in situ development in the copepod Calanus finmarchicus were investigated during late spring in 1988 and 1989 in the southern Gulf of Maine. This region is an important feeding ground for the planktivorous right whale, Eubalaena glacialis. The 1988 study took place during the declining spring bloom, with phytoplankton biomass variable, but relatively high. The 1989 study occurred after seasonal stratification, and phytoplankton biomass was low. During the 1988 cruise the dominant stage in C. finmarchicus shifted from C1-C2 to C4-C5. Stage durations during 1988 (4.0 days for C3 and 6.6 days for C4), estimated from the temporal change in stage distribution, were similar to maximal values observed in the laboratory. In contrast, during 1989 stages C4 and C5 were dominant throughout the study period and development rate was slow (estimated C4 stage duration about 24 days). Diel vertical migration patterns changed, from an absence of migration at the first two 1988 stations where younger stages predominated (C1-C3), to a very strong diel vertical migration at the later 1988 stations where stages C3-C3 predominated. This was not a simple ontogenetic change in migratory behavior since all copepodite stages at each station showed similar patterns. During 1989 dense aggregations of C. finmarchicus remained in the surface layer both day and night, and no diel vertical migration was observed. A small, nonmigratory population of late-stage C. finmarchicus was found at depth. Individual body size of these copepods was considerably greater than those found at the surface. Differences in development rate between years reflect differences in the food environment, brought about by seasonal hydrographic changes and the development of more intense stratification. Diel vertical migration patterns, however, did not show a simple relation with food availability, and it is suggested that predation may play an important role in

  9. Orbital-scale nonlinear response of East Asian summer monsoon to its potential driving forces in the late Quaternary

    NASA Astrophysics Data System (ADS)

    Yi, Liang; Shi, Zhengguo; Tan, Liangcheng; Deng, Chenglong

    2017-06-01

    We conducted a statistical study to characterize the nonlinear response of the East Asian summer monsoon (EASM) to its potential forcing factors over the last 260 ka on orbital timescales. We find that both variation in solar insolation and global ice volume were responsible for the nonlinear forcing of orbital-scale monsoonal variations, accounting for 80% of the total variance. Specifically, EASM records with dominated precession variance exhibit a more sensitive response to changes in solar insolation during intervals of enhanced monsoon strength, but are less sensitive during intervals of reduced monsoon strength. In the case of global ice volume with 100-ka variance, this difference is not one of sensitivity but rather a difference in baseline conditions, such as the relative areas of land and sea which affected the land-sea thermal gradient. We therefore suggest that EASM records with dominated precession variance recorded the signal of a shift in the location of the Inter-tropical Convergence Zone, and the associated changes in the incidence of torrential rainfall; while for proxies with dominated 100-ka variance, it recorded changes in the land-sea thermal gradient via its effects on non-torrential precipitation.

  10. Shift in principal equilibrium current from a vertical to a toroidal one towards the initiation of a closed flux surface in ECR plasmas in the LATE device

    NASA Astrophysics Data System (ADS)

    Kuroda, Kengoh; Wada, Manato; Uchida, Masaki; Tanaka, Hitoshi; Maekawa, Takashi

    2016-02-01

    In toroidal electron cyclotron resonance (ECR) plasmas under a weak external vertical field {{B}\\text{V}} a part of the pressure driven vertical charge separation current returns along the helical field lines, generating a toroidal current. The rest circulates via the conducting vacuum vessel. Only the toroidal current contributes to the production of a closed flux surface. Both the toroidal and vertical currents are an equilibrium current that provides a radial force by the interaction with the vertical field and the toroidal field, respectively, to counter-balance the outward pressure ballooning force. We have done experiments using 2.45 GHz microwaves in the low aspect ratio torus experiment (LATE) device to investigate in what way and how much the toroidal current is generated towards the initiation of a closed flux surface. In steady discharges by {{P}\\text{inj}}=1.5 kW under various {{B}\\text{V}} both the pressure and the toroidal current become large with {{B}\\text{V}} . When {{B}\\text{V}}=6.8 G, a toroidal current of 290 A is generated and the vertical field is reduced to 1.2 G inside the current channel, being close to the initiation of a closed flux surface. In this plasma the return current does not obey Ohm’s law. Instead, the return current flows so that the electric force on the electron fluid is balanced with the pressure gradient along the field lines. Near the top and bottom boundaries superthermal electrons flow beyond the potential barrier onto the walls along the field lines. In another discharge by the low power of {{P}\\text{inj}}=1.0 kW under {{B}\\text{V}}=8.3 G, both the toroidal current and the pressure steadily increase for an initial duration of 1.1 s and then abruptly jump, generating an initial closed flux surface. While the counter force from the vertical current is initially dominant, that from the toroidal current gradually increases and becomes four times larger than that from the vertical current just before the initiation

  11. Late-summer mass deposition of gelatinous phytodetritus along the slope of the N.W. European Continental Margin

    NASA Astrophysics Data System (ADS)

    de Wilde, P. A. W. J.; Duineveld, G. C. A.; Berghuis, E. M.; Lavaleye, M. S. S.; Kok, A.

    1998-12-01

    In the period 1993-1995 the OMEX area has been visited 3 times to address the question of across-slope transport of suspended matter from the shelf to the deep sea. By analyzing phytopigments and nucleic acids in the sediment and water of the N.W. European Continental slope and rise seasonal patterns of benthic food input were investigated and relation between input and the structure and activity of the benthic community were explored. Chloropigments in the surface sediments indicated that a spring bloom effect could be traced down to about 2500 m. During late August 1995 heavy deposits of gelatinous matter, characterized by high concentrations of chloropigments and nucleic acids, were detected all over the ocean floor of the outer slope and continental rise below 3500 m. It is estimated that this mucus layer had a carbon load of 250 mmol C m -2 over an area of 50,000 km 2. The recent state of the mucus allowed us to search for its origin. Characteristic pigment composition and the presence of coccoliths pointed to prymnesiophytes (coccolithophorids) as a major contributor, but dinoflagellates (peridinin) and green algae (chlorophyll-b, lutein) must have contributed as well. Simultaneous observations of the overlying water column, deep chlorophyll maximum, revealed the presence of a coccolithophorid bloom in a recent stage of disintegration at St. III. An obvious relation with the mucus carpet, however, could not be indicated. This, and the significant differences in pigment composition and pigment ratios at the various deep stations lead us to understand that the extended mucus field at the Celtic slope originates from different, more or less synoptically occurring surface blooms. The presence of large `vacuum-cleaning' sea-cucumbers is considered indicative of the occurrence of phytodetritus pulses.

  12. Spatiotemporal dynamics of visual vertical judgments: early and late brain mechanisms as revealed by high-density electrical neuroimaging.

    PubMed

    Lopez, C; Mercier, M R; Halje, P; Blanke, O

    2011-05-05

    Constructing and updating an internal model of verticality is fundamental for maintaining an erect posture and facilitating visuo-spatial processing. The judgment of the visual vertical (VV) has been intensively studied in psychophysical investigations and relies mainly on the integration of visual and vestibular signals, although a contribution of postural and somatosensory signals has been reported. Here we used high-density 192-channel evoked potential (EP) mapping and distributed source localization techniques to reveal the neural mechanisms of VV judgments. VV judgments (judging the orientation of visual lines with respect to the subjective vertical) were performed with and without a tilted visual frame. EP mapping revealed a sequence of neural processing steps (EP maps) of which two were specific for VV judgments. An early EP map, observed at ∼75-105 ms post-stimulus, was localized in right lateral temporo-occipital cortex. A later EP map (∼260-290 ms) was localized in bilateral temporo-occipital and parieto-occipital cortex. These data suggest that early VV-related neural processing involves the lateral and ventral visual stream and is related to visual processing concerning orientation, attention and comparison. The later, more dorsal, activation involves multimodal cortex subtending a constantly available and updated internal model of the vertical that we can refer to for the control of one's posture, actions, and visuo-spatial processing. Copyright © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.

  13. Inter-annual variability of H2O ice deposits observed in late summer, at the time of minimum extent of the Southern polar cap of Mars

    NASA Astrophysics Data System (ADS)

    Langevin, Y.; Seelos, K.; Russel, P.; Bibring, J.-P.; Gondet, B.; Vincendon, M.

    2012-04-01

    Extended regions exhibiting water ice signatures have been observed by OMEGA on Mars Express at the boundary of the CO2 perennial cap during the first months of operation of the mission [1]. This period in late summer ( Ls 335°-340° corresponds to the minimum extent of the ice coverage around the South pole. The retreat of the South seasonal cap, spectrally dominated by CO2 frost [2, 3] ends at Ls 310° - 315° for years which do not present a global dust storm [4], and the first signs of H2O frost re-condensation are observed before the fall equinox (Ls 0°). A large outlier had been identified by OMEGA observations at longitudes from 290°E to 10°E. It was shown to extend over an area representing ~ 25% of the surface of the perennial cap by Themis observations [5]. The H2O covered regions at the boundary of the cap and within the outlier have an intermediate albedo (30-35%) between that of the perennial cap (> 60%) and that of surrounding terrains (~ 20%). It is interesting to note that these regions are those still covered by bright ice at Ls 310° [4] , which have been spectrally identified as CO2 ice [2]. The retreat of the seasonal cap is therefore delayed by ~ 1 month over H2O ice deposits. In late 2009, OMEGA observations of the South cap at the time of minimum extent (Ls 340°) showed a much larger extent of H2O ice signatures compared to what had been observed in early 2004 [1]. H2O ice covered regions appeared homogeneous at the km scales corresponding to OMEGA observations. A series of CRISM observations were planned for the next southern fall season (mid-2011), in order to further investigate the time variability of the southern H2O ice deposits within the outlier. The FOV of CRISM does not make it possible to map large regions at full regions, and we focused on areas within or at the boundary of the outlier. The results demonstrate that the extent of the outlier in 2011 is more similar to 2004 than to 2009. Another important result is that within

  14. Influence of a large late summer precipitation event on food limitation and grasshopper population dynamics in a northern Great Plains grassland.

    PubMed

    Branson, David H

    2008-06-01

    The complex interplay between grasshoppers, weather conditions, and plants that cause fluctuations in grasshopper populations remains poorly understood, and little is known about the ecological processes that generate grasshopper outbreaks. Grasshopper populations respond to interacting extrinsic and intrinsic factors, with yearly and decadal weather patterns and the timing of precipitation all potentially important. The effects of initial and increasing grasshopper densities on grasshopper survival and reproductive correlates were examined at a northern mixed-grass prairie site through manipulations of grasshopper densities inside 10-m2 cages. High-quality grass growth occurred after a 9.1-cm mid-August rain. Reduced proportional survival was apparent in the two higher density treatments before the rain, indicative of food-limited density-dependent mortality. However, the large late summer rainfall event mediated the effects of exploitative competition on demographic characteristics because of the high-quality vegetation growth. This led to weaker effects of food limitation on survival and reproduction at the end of the experiment. The results indicate a direct link between weather variation, resource quality and grasshopper population dynamics led to a severe grasshopper outbreak and show that infrequent large precipitation events can have significant effects on population dynamics. Additional research is needed to examine the importance of infrequent large precipitation events on grasshopper population dynamics in grassland ecosystems.

  15. Anomalous western Pacific subtropical high during late summer in weak La Niña years: Contrast between 1981 and 2013

    NASA Astrophysics Data System (ADS)

    Xue, Feng; Fan, Fangxing

    2016-12-01

    Both 1981 and 2013 were weak La Niña years with a similar sea surface temperature (SST) anomaly in the tropical Pacific, yet the western Pacific subtropical high (WPSH) during August exhibited an opposite anomaly in the two years. A comparison indicates that, in the absence of a strong SST anomaly in the tropics, the cold advection from Eurasian high latitudes and the convection of the western Pacific warm pool play important roles in influencing the strength and position of the WPSH in August. In August 1981, the spatial pattern of 500 hPa geopotential height was characterized by a meridional circulation with a strong ridge in the Ural Mountains and a deep trough in Siberia, which provided favorable conditions for cold air invading into the lower latitudes. Accordingly, the geopotential height to the north of the WPSH was reduced by the cold advection anomaly from high latitudes, resulting in an eastward retreat of the WPSH. Moreover, an anomalous cyclonic circulation in the subtropical western Pacific, excited by enhanced warm pool convection, also contributed to the eastward retreat of the WPSH. By contrast, the influence from high latitudes was relatively weak in August 2013 due to a zonal circulation pattern over Eurasia, and the anomalous anticyclonic circulation induced by suppressed warm pool convection also facilitated the westward extension of the WPSH. Therefore, the combined effects of the high latitude and tropical circulations may contribute a persistent anomaly of the WPSH in late summer, despite the tropical SST anomaly being weak.

  16. Late Quaternary evolution of the East Asian summer monsoon: Clay and magnetic mineralogical records retrieved from the northern South China Sea

    NASA Astrophysics Data System (ADS)

    Chen, Q.; Liu, Z.; Kissel, C.

    2016-12-01

    East Asian monsoon is a major component of global monsoon system. Acting as the largest marginal sea in the western Pacific, the South China Sea is a natural laboratory recording East Asian monsoon evolution. In order to reconstruct the late Quaternary evolution of the monsoon, we analyzed in details the 50.8-m-long Core MD12-3432 retrieved from the northern South China Sea at 2125 m water depth. Carbonate and magnetic stratigraphy indicates that Core MD12-3432 covers the last 400 ka. Clay mineralogical analysis was performed every 10 cm using XRD method. Bulk magnetic properties (susceptibility, NRM, ARM, and IRM) were measured on u-channel samples with a resolution of 2 cm. Cumulative log Gaussian decomposition analysis was performed on 33 high resolution IRM acquisition curves to evaluate the contribution of coercivity components. Three-axis thermal demagnetization was conducted on 14 samples to identify the nature of magnetic minerals. Clay mineral assemblage of Core MD12-3432 is dominated by smectite (23-59%) and illite (22-43%), with minor chlorite (13-27%) and kaolinite (4-13%). Because smectite is formed by rapid chemical weathering of volcanic rocks in Luzon, while illite and chlorite are primary minerals formed by physical erosion, smectite/(illite+chlorite) ratio constitutes a proxy of chemical weathering intensity. Magnetic fraction of Core MD12-3432 is composed by minerals with different coercivities, the relative proportion of which varies along the core. The high coercivity is carried by hematite and the low coercivity fraction is mainly composed by magnetite with some iron-sulphides. Luzon is the most efficient source of magnetite because of the rapid eluviation and weathering of volcanic rocks, while the Pearl River basin is the only source that produces hematite mainly through physical degradation of bedrocks. Thus, the bulk coercivity as indicated by S-ratio can serve as a proxy of chemical weathering. Both indicators, smectite

  17. Distributions of low molecular weight dicarboxylic acids, ketoacids and α-dicarbonyls in the marine aerosols collected over the Arctic Ocean during late summer

    NASA Astrophysics Data System (ADS)

    Kawamura, K.; Ono, K.; Tachibana, E.; Charriére, B.; Sempéré, R.

    2012-11-01

    Oxalic and other small dicarboxylic acids have been reported as important water-soluble organic constituents of atmospheric aerosols from different environments. Their molecular distributions are generally characterized by the predominance of oxalic acid (C2) followed by malonic (C3) and/or succinic (C4) acids. In this study, we collected marine aerosols from the Arctic Ocean during late summer in 2009 when sea ice was retreating. The marine aerosols were analyzed for the molecular distributions of dicarboxylic acids as well as ketocarboxylic acids and α-dicarbonyls to better understand the source of water-soluble organics and their photochemical processes in the high Arctic marine atmosphere. We found that diacids are more abundant than ketoacids and α-dicarbonyls, but their concentrations are generally low (< 30 ng m-3), except for one sample (up to 70 ng m-3) that was collected near the mouth of Mackenzie River during clear sky condition. Although the molecular compositions of diacids are in general characterized by the predominance of oxalic acid, a depletion of C2 was found in two samples in which C4 became the most abundant. Similar depletion of oxalic acid has previously been reported in the Arctic aerosols collected at Alert after polar sunrise and in the summer aerosols from the coast of Antarctica. Because the marine aerosols that showed a depletion of C2 were collected under the overcast and/or foggy conditions, we suggest that a photochemical decomposition of oxalic acid may have occurred in aqueous phase of aerosols over the Arctic Ocean via the photo dissociation of oxalate-Fe (III) complex. We also determined stable carbon isotopic compositions (δ13C) of bulk aerosol carbon and individual diacids. The δ13C of bulk aerosols showed -26.5‰ (range: -29.7 to -24.7‰, suggesting that marine aerosol carbon is derived from both terrestrial and marine organic materials. In contrast, oxalic acid showed much larger δ13C values (average: -20.9‰, range

  18. Distributions of low molecular weight dicarboxylic acids, ketoacids and α-dicarbonyls in the marine aerosols collected over the Arctic Ocean during late summer

    NASA Astrophysics Data System (ADS)

    Kawamura, K.; Ono, K.; Tachibana, E.; Charriére, B.; Sempéré, R.

    2012-08-01

    Oxalic and other small dicarboxylic acids have been reported as important water-soluble organic constituents of atmospheric aerosols from different environments. Their molecular distributions are generally characterized by the predominance of oxalic acid (C2) followed by malonic (C3) and/or succinic (C4) acids. In this study, we collected marine aerosols from the Arctic Ocean during late summer in 2009 when sea ice is retreated. The marine aerosols were analyzed for the molecular distributions of dicarboxylic acids as well as ketocarboxylic acids and α-dicarbonyls to better understand the source of water-soluble organics and their photochemical processes in the high Arctic marine atmosphere. We found that diacids are more abundant than ketoacids and α-dicarbonyls, but their concentrations are generally low (< 30 ng m-3), except for one sample (up to 70 ng m-3) that was collected near the mouth of Mackenzie River during clear sky condition. Although the molecular compositions of diacids are in general characterized by the predominance of oxalic acid, a depletion of C2 was found in two samples in which C4 became the most abundant. Similar depletion of oxalic acid has previously been reported in the Arctic aerosols collected at Alert after polar sunrise and in the summer aerosols from the coastal Antarctica. Because the marine aerosols that showed a depletion of C2 were observed under the overcast and/or foggy conditions, we suggest that a photochemical decomposition of oxalic acid may have occurred in aqueous phase of aerosols over the Arctic Ocean via the photo dissociation of oxalate-Fe (III) complex. We also determined stable carbon isotopic compositions (δ13C) of bulk aerosol carbon and individual diacids. The δ13C of bulk aerosols showed -26.5‰ (range: -29.7‰ to -24.7‰), suggesting that marine aerosol carbon is derived from both terrestrial and marine organic materials. In contrast, oxalic acid showed much larger δ13C values (average: -20.9‰, range

  19. Late Quaternary vegetation and climate dynamics at the northern limit of the East Asian summer monsoon and its regional and global-scale controls

    NASA Astrophysics Data System (ADS)

    Leipe, Christian; Nakagawa, Takeshi; Gotanda, Katsuya; Müller, Stefanie; Tarasov, Pavel E.

    2015-05-01

    A late Quaternary pollen record from northern Sakhalin Island (51.34°N, 142.14°E, 15 m a.s.l.) spanning the last 43.7 ka was used to reconstruct regional climate dynamics and vegetation distribution by using the modern analogue technique (MAT). The long-term trends of the reconstructed mean annual temperature (TANN) and precipitation (PANN), and total tree cover are generally in line with key palaeoclimate records from the North Atlantic region and the Asian monsoon domain. TANN largely follows the fluctuations in solar summer insolation at 55°N. During Marine Isotope Stage (MIS) 3, TANN and PANN were on average 0.2 °C and 700 mm, respectively, thus very similar to late Holocene/modern conditions. Full glacial climate deterioration (TANN = -3.3 °C, PANN = 550 mm) was relatively weak as suggested by the MAT-inferred average climate parameters and tree cover densities. However, error ranges of the climate reconstructions during this interval are relatively large and the last glacial environments in northern Sakhalin could be much colder and drier than suggested by the weighted average values. An anti-phase relationship between mean temperature of the coldest (MTCO) and warmest (MTWA) month is documented during the last glacial period, i.e. MIS 2 and 3, suggesting more continental climate due to sea levels that were lower than present. Warmest and wettest climate conditions have prevailed since the end of the last glaciation with an optimum (TANN = 1.5 °C, PANN = 800 mm) in the middle Holocene interval (ca 8.7-5.2 cal. ka BP). This lags behind the solar insolation peak during the early Holocene. We propose that this is due to continuous Holocene sea level transgression and regional influence of the Tsushima Warm Current, which reached maximum intensity during the middle Holocene. Several short-term climate oscillations are suggested by our reconstruction results and correspond to Northern Hemisphere Heinrich and Dansgaard-Oeschger events, the B

  20. The role of biophysical indicators in the reconstruction of long-term late-spring - summer temperatures for the region of Western Hungary and Eastern Austria

    NASA Astrophysics Data System (ADS)

    Kiss, Andrea; Wilson, Rob; Holawe, Franz; Strömmer, Elisabeth; Bariska, István.

    2010-05-01

    , Sopron and Bratislava series and all presented analyses were developed within the framework of the EU project 'Millenium'. The Austrian series are partly based on published series (Pribram 1938, Lauscher 1985, Strömmer 2003) although in some cases modified and extended for this study, as well as newly developed data. The present work is a continuation of the 'Analysis of late spring-summer temperatures for Western Hungary based on vine, grain tithes and harvest records', presented at the annual congress of EGU in 2009 (Kiss and Wilson 2009). References Böhm, R., Jones, P.D., Hiebl, J., Frank, D., Brunetti, M., Maugeri and M. 2009: The early instrumental warm-bias: a solution for long central European temperature series 1760-2007. Climatic Change, doi: 10.1007/s10584-009-9649-4. Kiss, A. and Wilson, R. 2009: Analysis of late spring-summer temperatures for Western Hungary based on vine, grain tithes and harvest records. Geophysical Research Abstracts Vol 11, EGU2009-10945-1. Lauscher, F. 1985: Beiträge zur Wetterchronik seit dem Mittelalter. In: Sitzungsberichte, Abtheilung II, Mathematische, Physikalische und Technische Wissenschaften, Band 194, Heft 1-3. pp. 93-131. Leijonhufvud, L., Wilson, R., Möberg, A., Söderberg, J., Retső, D. and Söderlind, U. 2009: Five centuries of Stockholm winter/spring temperatures reconstructed from documentary evidence and instrumental observations. Climatic Change, doi: 10.1007/s10584-009-9650-y. Pribram, A. F. 1938: Materialien zur Geschichte der Preise und Löhne in Österreich. Band. I. Carl Ueberreuters Verlag, Wien. pp. 364-370. Strömmer, E. 2003: Klima-Geschichte. Methoden der Rekonstruction und historische Perspektive. Ostösterreich 1700 bis 1830. Forschungen und Beiträge zur Wiener Stadtgescichte 39. Franz Deuticke, Wien. pp. 59-71.

  1. Inconsistent Climate Inferences between Pollen and other Paleontological, Geochemical, and Geophysical Proxies in Late Pleistocene Lacustrine Sediments from Summer Lake, Oregon, Western Great Basin

    NASA Astrophysics Data System (ADS)

    Heaton, E.; Thompson, G.; Negrini, R. M.; Wigand, P. E.

    2015-12-01

    This study has established a high resolution paleoclimate record from western Great Basin pluvial Summer Lake, Oregon during the late Pleistocene Mono Lake Excursion (~34 ka), Dansgaard-Oeschger (D-O) interstadials 7 and 8, and the end of Heinrich Even 4 (~38 ka). Proxies of grain-size, carbon/nitrogen (C/N) ratio, ostracode analysis and palynology from a depocenter core show new results regarding high amplitude, high frequency changes in lake level, precipitation and temperature which correspond directly with colder/warmer and respectively drier/wetter climates as documented with Northern Atlantic Greenland ice core data. The granulometry, geochemical, and ostracode results consistently demonstrate the correspondence of low lake conditions and colder water temperatures during D-O stadials and warmer/wetter climate during interstadials. These results are contradicted by the pollen results. Existence of cold temperature spores Botrychium and Selaginella coincide with increases in Artemisia, Atriplex, Sarcobatus, Cyperaceae and decreases in Pinus, also suggesting periods of colder/drier climate and shallower lake levels but the timing does not match that of those conditions inferred by the other methods. Granulometry, geochemical, and ostracode proxies denote cold periods and low lake levels roughly between 37.5-35.6 ka and 34.6-33.8 ka. Pollen analysis suggests near-opposite time intervals with cold periods roughly 38-37.5 ka, 35.6-35 ka. This pollen inconsistency suggests the possibility of (1) a millennial-scale lag response of vegetation to climate change, (2) runoff from stadial precipitation causing influx in pollen abundances and variety found in the depocenter core, or (3) turbulent mixing from shallow lake level causing resuspension and redeposition of pollen (Bradley 1999).

  2. The role of vertical land movements on late 19th century sea level rise at Cuxhaven, Germany

    NASA Astrophysics Data System (ADS)

    Niehüser, Sebastian; Jensen, Jürgen; Wahl, Thomas; Dangendorf, Sönke; Hofstede, Jacobus

    2015-04-01

    Tide gauges, located along the world's coastlines, represent one of the most important data sources with information about sea level change back into the 17th century, bridging the gap between paleo proxies and modern remote sensing data sources. While the worldwide coverage of tide gauges has increased considerably since the mid-20th century, there are only a few gauges available providing information about regional sea level changes before 1900. Furthermore, these tide gauge measurements are often contaminated by local vertical land movements (VLM) resulting from tectonic processes or local anthropogenic interventions. Such non-climatic effects need to be removed from the raw data to uncover climate signals, which are important, for instance, for answering the question whether and when sea level started to accelerate from the nearly constant rates over the past 2000 years. Here we focus on one of these long tide gauge records: Cuxhaven, which is located in the German Bight and provides uninterrupted digital time series of tidal high and low water levels since 1843. The record has been extensively studied during the past decades with respect to regional and global sea level rise. However, a question that still remains is the role of local subsidence before 1900 at the lighthouse of Cuxhaven, located close to the tide gauge. In 1855 Lentz installed a granite height mark at the lighthouse, which was later used as a proxy for VLMs of the tide gauge itself. The height of the control mark was derived by a levelling between Hamburg and Cuxhaven. These levellings were repeated five times between 1855 and 1900 and later evaluated by Siefert and Lassen (1985) with respect to the role of local subsidence. Based on a linear regression of individual levellings Siefert and Lassen (1985) concluded that the lighthouse subsided by an average rate of 2.8 mm/yr (1855-1875: 4.2 mm/yr; 1876-1890: 2 mm/yr; 1890-1900: 1.2 mm/yr). However, due to the massive uncertainties of these early

  3. Late Quaternary depositional history, Holocene sea-level changes, and vertical crustal movement, southern San Francisco Bay, California

    USGS Publications Warehouse

    Atwater, Brian F.; Hedel, Charles W.; Helley, Edward J.

    1977-01-01

    Sediments collected for bridge foundation studies at southern San Francisco Bay, Calif., record estuaries that formed during Sangamon (100,000 years ago) and post-Wisconsin (less than 10,000 years ago) high stands of sea level. The estuarine deposits of Sangamon and post-Wisconsin ages are separated by alluvial and eolian deposits and by erosional unconformities and surfaces of nondeposition, features that indicate lowered base levels and oceanward migrations of the shoreline accompanying low stands of the sea. Estuarine deposits of mid-Wisconsin age appear to be absent, suggesting that sea level was not near its present height 30,000–40,000 years ago in central California. Holocene sea-level changes are measured from the elevations and apparent 14C ages of plant remains from 13 core samples. Uncertainties of ±2 to ±4 m in the elevations of the dated sea levels represent the sum of errors in determination of (1) sample elevation relative to present sea level, (2) sample elevation relative to sea level at the time of accumulation of the dated material, and (3) postdepositional subsidence of the sample due to compaction of underlying sediments. Sea level in the vicinity of southern San Francisco Bay rose about 2 cm/yr from 9,500 to 8,000 years ago. The rate of relative sea-level rise then declined about tenfold from 8,000 to 6,000 years ago, and it has averaged 0.1–0.2 cm/yr from 6,000 years ago to the present. This submergence history indicates that the rising sea entered the Golden Gate 10,000–11,000 years ago and spread across land areas as rapidly as 30 m/yr until 8,000 years ago. Subsequent shoreline changes were more gradual because of the decrease in rate of sea-level rise. Some of the sediments under southern San Francisco Bay appear to be below the level at which they initially accumulated. The vertical crustal movement suggested by these sediments may be summarized as follows: (1) Some Quaternary(?) sediments have sustained at least 100 m of

  4. Preliminary Vertical Slip Rate for the West Tahoe Fault from six new Cosmogenic 10Be Exposure Ages of Late Pleistocene Glacial Moraines at Cascade Lake, Lake Tahoe, California

    NASA Astrophysics Data System (ADS)

    Pierce, I. K. D.; Wesnousky, S. G.; Kent, G. M.; Owen, L. A.

    2015-12-01

    The West Tahoe Fault is the primary range bounding fault of the Sierra Nevada at the latitude of Lake Tahoe. It is a N-NW striking, east dipping normal fault that has a pronounced onshore quaternary scarp extending from highway 50 southwest of Meyers, CA to Emerald Bay. At Cascade Lake, the fault cuts and progressively offsets late Pleistocene right lateral moraines. The fault vertically offsets the previously mapped Tahoe moraine ~83 m and the Tioga moraine ~23 m, measured from lidar data. Seventeen samples were collected for 10Be cosmogenic age analysis from boulders on both the hanging and footwalls of the fault along the crests of these moraines.We report here the initial analysis of 6 of these boulders and currently await processing of the remainder. The 10Be exposure ages of 3 boulders each on the younger Tioga and older Tahoe moraines range from 12.7 +/- 1.6 to 20.7 +/- 3.3 ka and 13.3 +/- 2.1 to 72.5 +/- 8.8 ka, respectively. Using the oldest ages as minima, these preliminary results suggest that the slip rate has averaged ~1 mm/yr since the penultimate glaciation, in accord with estimates of previous workers, and place additional bounds on the age of glaciation in the Lake Tahoe basin. The Last Glacial Maxima and penultimate glaciation near Lake Tahoe thus appear to coincide with the Tioga and Tahoe II glaciations of the Eastern Sierra.

  5. Late Mesozoic to Early Cenozoic components of vertical separation across the Møre Trøndelag Fault complex, Norway

    NASA Astrophysics Data System (ADS)

    Redfield, T. F.; Braathen, A.; Gabrielsen, R. H.; Osmundsen, P. T.; Torsvik, T. H.; Andriessen, P. A. M.

    2005-01-01

    Low temperature apatite fission track (AFT) data from two horizontal transects across the Møre-Trøndelag Fault Complex (MTFC) and along the coast of the Fosen peninsula have defined a complicated series of structural blocks whose exhumation to temperatures cooler than the uppermost apatite Partial Annealing Zone (PAZ) occurred during a broad Mesozoic to Cenozoic time span. The ˜100 million year cooling difference between the innermost and outermost blocks indicates they were subjected to very different exhumation pathways. Track length histograms and inverse model results also suggest that significant differences in thermal histories are present over very short horizontal distances. In conjunction with the offshore geological evidence, the AFT data and models strongly suggest that the innermost zones of the MTFC underwent between 2 and 4 km of structurally controlled net vertical rock column uplift/subsidence following latest Cretaceous time, and potentially much of the Tertiary as well. The up-to-the-east down-to-the-west relative offset at the Norwegian margin is interpreted in terms of a flexed, nearly broken lithospheric plate architectural model for late Mesozoic and Tertiary Scandes mountain building, whose driving force was likely dominanted by erosionally induced loading/unloading at the margin.

  6. High resolution satellite microwave record of Russian High Arctic snowmelt timing, duration, and relation to late summer sea ice extent (Invited)

    NASA Astrophysics Data System (ADS)

    Ramage, J. M.; Zhao, M.; Semmens, K. A.; Obleitner, F.

    2013-12-01

    and passive microwave satellite data, and analyze the TMD correlations with local temperature and regional sea ice extent. MOD for the icecaps is defined as the first day when more than 90% of ice-covered pixels start melting and is derived from multiple sensors between 1992 and 2012. Total TMD are the cumulative number of days that experienced melt days over the entire year, including short-lived events before or after the main melt season. The glacier surface snowpack on SevZ melted significantly earlier (-7.3 days/decade) from 1992 to 2012 and significantly longer (7.7 days/decade) from 1995 to 2011. NovZ experienced large interannual variability in MOD, but its annual mean TMD increased. The snowpack melt on NovZ is more sensitive to temperature fluctuations than SevZ in recent decades. The TMD on both archipelagoes is statistically anti-correlated with regional late summer sea ice extent, linking land ice melt dynamics to regional sea ice extent variations.

  7. Late Paleozoic vertical crustal growth of Western Junggar, Xinjiang in China: evidence from petrology and Nd isotope in charnockites and alkaline granites

    NASA Astrophysics Data System (ADS)

    Xian, W. S.; Sun, M.; Zhang, L. F.; Zhao, G. C.; Malpas, J.

    2003-04-01

    underplating of mantle-derived magmas. Laser Raman microspectrometer studies indicate that the fluid inclusions in quartz crystals of charnockites are exclusively C0_2-rich, suggesting that C0_2 may have played an important role in the petrogenesis of charnockites. Nd isotopic data reveal a juvenile nature of the lower crust in the studied area. ɛNd(t) values increase from the granulite enclaves through the charnockites and alkaline granites to the latest intermediate dykes, indicating that more and more mantle components were involved during the formation and evolution of the western Junggar granitoid complex. Based on this study and our previous data, we propose the following scenario for the vertical growth of the crust in the western Junggar area during the late Paleozoic. At ˜305 Ma, the western Junggar area (probably in the whole Central Asian Orogen) underwent an extensional event and large amounts of mantle-sourced magmas (basaltic magmas) were underplated beneath the bottom of the lower crust, which resulted in the partial melting of the lower crust to form the charnockites. Subsequently, at ˜274Ma, the newly-formed lower crust from underplating basalts was heated and partially melted to produce granitic magmas that formed numerous alkaline granites in the area. This conclusion is further supported by the presence of fine-grained, myrmekitic clinopyroxenes within coarse-grained othopyroxene in the charnockites, which we interpret as an anatectic texture that formed during the emplacement of alkaline granitic magmas with higher temperature (e.g. 900^oC). Therefore, we believe that the understating of basaltic magmas has played an important role in the formation of the charnockites and alkaline granite, that has resulted in a significant vertical growth of the western Junggar crust in the late Paleozoic time.

  8. The Role of Late Summer Melt Pond Water Layers in the Ocean Mixed Layer on Enhancing Ice/Ocean Albedo Feedbacks in the Arctic

    NASA Astrophysics Data System (ADS)

    Stanton, T. P.; Shaw, W. J.

    2016-02-01

    Drainage of surface melt pond water into the top of the ocean mixed layer is seen widely in the Arctic ice pack in later summer (for example Gallaher et al 2015). Under calm conditions, this fresh water forms a thin, stratified layer immediately below the ice which is dynamically decoupled from the thicker, underlying seasonal mixed layer by the density difference between the two layers. The ephemeral surface layer is significantly warmer than the underlying ocean water owing to the higher freezing temperature of the fresh melt water. How the presence of this warm ephemeral layer enhances basal melt rate and speeds the destruction of the floes is investigated. High resolution timeseries measurements of T/S profiles in the 2m of the ocean immediately below the ice, and eddy-correlation fluxes of heat, salt and momentum 2.5m below the ice were made from an Autonomous Ocean Flux Buoy over a 2 month interval in later summer of 2015 as a component of the ONR Marginal Ice Zone project. The stratification and turbulent forcing observations are used with a 1 D turbulence closure model to understand how momentum and incoming radiative energy are stored and redistributed within the ephemeral layer. Under low wind forcing conditions both turbulent mixing energy and the water with high departure from freezing are trapped in the ephemeral layer by the strong density gradient at the base of the layer, resulting in rapid basal melting. This case is contrasted with model runs where the ephemeral layer heat is allowed to mix across the seasonal mixed layer, which results in slower basal melt rates. Consequently, the salinity-trapped warm ephemeral layer results in the formation of more open water earlier in the summer season, in turn resulting in increased cumulative heating of the ocean mixed layer, enhancing ice/ocean albedo feedbacks.

  9. Composition and distribution of planktonic ciliates in the southern South China Sea during late summer: Comparison between surface and 75 m deep layer

    NASA Astrophysics Data System (ADS)

    Liu, Huaxue; Shen, Pingping; Li, Chunhou; Chen, Zuozhi; Qi, Zhanhui; Huang, Honghui

    2016-02-01

    Ciliates are very important components in most marine ecosystem. They are trophic link between the microbial food web and grazing food chain. In this study, ciliates were collected from 11 sites in the southern South China Sea (SCS) during August 25 to September 28, 2011. Their composition and distribution at the surface and 75 m deep depth of the ocean were studied. A total of 30 species belonging to 22 genera were identified, and 22 species of 15 genera were Tintinnids. Eutintinnus fraknoii and E. stramentus were the most common species. The other dominants were strombidiids ciliates including Strombidium conicum and S. globosaneum, which were followed by the tide form, Mesodinium pulex. Ciliates abundance ranged from 46 ind L-1 to 368 ind L-1 in the open sites, 46-368 ind L-1 at surface and 73-198 ind L-1 at 75 m deep layer. In the Yongshu reef, ciliates abundance ranged from 167 ind L-1 to 365 ind L-1 in the water column, similar to that in Sanya coral reef waters. Ciliates composition showed obvious difference between surface and 75 m deep layer at station S2 ( P < 0.05), while no similar result was observed at other sites. At 75 m deep layer, salinity was negatively related to mixed layer depth ( P < 0.05), but positively to chlorophyll a concentration ( P < 0.05), indicating that the change of vertical mixing in water column influenced vertical distribution of ciliates in the southern SCS.

  10. Multi-scale, multi-year investigations of H2O ice deposits observed in late summer, at the time of minimum extent of the Southern polar cap of Mars

    NASA Astrophysics Data System (ADS)

    Langevin, Y.; Seelos, K.; Russell, P.; Bibring, J.-P.; Vincendon, M.; Gondet, B.

    2012-09-01

    Extended regions exhibiting water ice signatures have been observed by OMEGA on Mars Express at the boundary of the CO2 perennial cap during the first months of operation of the mission [1]. This period in late summer (Ls 335°-340°) corresponds to the minimum extent of the ice coverage around the South pole. The retreat of the South seasonal cap, spectrally dominated by CO2 frost [2, 3] ends at Ls 310° - 315° for years which do not present a global dust storm [4], and the first signs of H2O frost recondensation are observed before the fall equinox (Ls 0°). A large outlier had been identified by OMEGA observations at longitudes from 290°E to 10°E. It was shown to extend over an area representing ~ 25% of the surface of the perennial cap by Themis observations [5]. The H2O covered regions at the boundary of the cap and within the outlier have an intermediate albedo (30-35%) between that of the perennial cap (> 60%) and that of surrounding terrains (~ 20%). These southern surface H2O ice deposits constitute a major source of atmospheric H2O at the end of the Southern summer. They are much smaller in extent than the northern perennial cap and they are exposed to sunlight for 2 months in late summer instead of 6 months in the North over the whole summer. This is in line with the highly asymmetric seasonal cycle of atmospheric water [6, 7]. In late 2009, OMEGA observations of the South cap at the time of minimum extent (Ls 340°) showed a much larger extent of H2O ice signatures compared to what had been observed in early 2004 [1]. H2O ice covered regions appeared homogeneous at the km scales corresponding to OMEGA observations. A series of CRISM observations were planned for the next southern fall season (mid-2011), in order to further investigate the time variability of the southern H2O ice deposits within the outlier at the 20 m scale (CRISM high resolution mode). Combining OMEGA and CRISM observations demonstrates that variegation of surface H2O ice is mainly

  11. Summer Astronomy

    ERIC Educational Resources Information Center

    Riddle, Bob

    2004-01-01

    This brief article describes what can be expected of the skies in the summer of 2004 with quite a few celestial thrills to anticipate. In addition to the planet viewing opportunities, there is a very rare Venus transit of the Sun and the annual Perseid meteor shower. The 2004 summer also marks both an end and beginning for the Cassini/Huygens…

  12. Summer Doldrums.

    ERIC Educational Resources Information Center

    Muchnick, Bruce

    2002-01-01

    For camp staff, factors that contribute to the summer doldrums are weather, level of general fatigue, unsatisfied expectations, sensory overload, accumulation of negative "self-talk," and an underlying sense of hurry. Strategies for overcoming summer doldrums involve novelty and stress management, and include promoting health, challenging…

  13. Summer Astronomy

    ERIC Educational Resources Information Center

    Riddle, Bob

    2004-01-01

    This brief article describes what can be expected of the skies in the summer of 2004 with quite a few celestial thrills to anticipate. In addition to the planet viewing opportunities, there is a very rare Venus transit of the Sun and the annual Perseid meteor shower. The 2004 summer also marks both an end and beginning for the Cassini/Huygens…

  14. Spatial variability of the species composition, abundance, and productivity of the phytoplankton in the white sea in the late summer period

    NASA Astrophysics Data System (ADS)

    Ilyash, L. V.; Radchenko, I. G.; Kuznetsov, L. L.; Lisitzyn, A. P.; Martynova, D. M.; Novigatskiy, A. N.; Chul'Tsova, A. L.

    2011-02-01

    The species composition, cell concentration ( N), and biomass ( B) of the phytoplankton, as well as the chlorophyll a (Chl a) concentration, primary production ( PP), and the concentrations of the dissolved inorganic micronutrients (phosphorus, silica, nitrogen as nitrite), were estimated for Kandalaksha Bay (KB), Dvina Bay (DB), and the basin (Bas) of the White Sea in August of 2004. The micronutrient concentrations were lower compared to the average long-term values for the summer period. The Chl a concentration varies from 0.9 to 2.0 mg/m3 for most of the studied areas, reaching up to 7.5 mg/m3 in the Northern Dvina River estuary. The surface water layer of the DB was the most productive area, where the PP reached up to 270-375 mg C/(m3 day). The phytoplankton biomass varied from 11 to 205 mg C/m3 with the highest values observed in the Bas and DB. Three groups of stations were defined during the analysis of the phytoplankton's species composition similarity. The dinoflagellates Dinophysis norvegica and Ceratium fusus were particular to the phytoplankton assemblages in the KB; the diatom Ditylum brightwellii was particular to the upper and central parts of the DB. These three phytoplankton species were less abundant in the Bas.

  15. Non-serotinous woody plants behave as aerial seed bank species when a late-summer wildfire coincides with a mast year.

    PubMed

    Pounden, Edith; Greene, David F; Michaletz, Sean T

    2014-10-01

    Trees which lack obvious fire-adaptive traits such as serotinous seed-bearing structures or vegetative resprouting are assumed to be at a dramatic disadvantage in recolonization via sexual recruitment after fire, because seed dispersal is invariably quite constrained. We propose an alternative strategy in masting tree species with woody cones or cone-like structures: that the large clusters of woody tissue in a mast year will sufficiently impede heat transfer that a small fraction of seeds can survive the flaming front passage; in a mast year, this small fraction would be a very large absolute number.In Kootenay National Park in British Columbia, we examined regeneration by Engelmann spruce (Picea engelmannii), a non-serotinous conifer, after two fires, both of which coincided with mast years. Coupling models of seed survivorship within cones and seed maturation schedule to a spatially realistic recruitment model, we show that (1) the spatial pattern of seedlings on a 630 m transect from the forest edge into the burn was best explained if there was in situ seed dissemination by burnt trees; (2) in areas several hundred meters from any living trees, recruitment density was well correlated with local prefire cone density; and (3) spruce was responding exactly like its serotinous codominant, lodgepole pine (Pinus contorta).We conclude that non-serotinous species can indeed behave like aerial seed bank species in mast years if the fire takes place late in the seed maturation period. Using the example of the circumpolar boreal forest, while the joint probability of a mast year and a late-season fire will make this type of event rare (we estimate P = 0.1), nonetheless, it would permit a species lacking obvious fire-adapted traits to occasionally establish a widespread and abundant cohort on a large part of the landscape.

  16. Non-serotinous woody plants behave as aerial seed bank species when a late-summer wildfire coincides with a mast year

    PubMed Central

    Pounden, Edith; Greene, David F; Michaletz, Sean T

    2014-01-01

    Abstract Trees which lack obvious fire-adaptive traits such as serotinous seed-bearing structures or vegetative resprouting are assumed to be at a dramatic disadvantage in recolonization via sexual recruitment after fire, because seed dispersal is invariably quite constrained. We propose an alternative strategy in masting tree species with woody cones or cone-like structures: that the large clusters of woody tissue in a mast year will sufficiently impede heat transfer that a small fraction of seeds can survive the flaming front passage; in a mast year, this small fraction would be a very large absolute number. In Kootenay National Park in British Columbia, we examined regeneration by Engelmann spruce (Picea engelmannii), a non-serotinous conifer, after two fires, both of which coincided with mast years. Coupling models of seed survivorship within cones and seed maturation schedule to a spatially realistic recruitment model, we show that (1) the spatial pattern of seedlings on a 630 m transect from the forest edge into the burn was best explained if there was in situ seed dissemination by burnt trees; (2) in areas several hundred meters from any living trees, recruitment density was well correlated with local prefire cone density; and (3) spruce was responding exactly like its serotinous codominant, lodgepole pine (Pinus contorta). We conclude that non-serotinous species can indeed behave like aerial seed bank species in mast years if the fire takes place late in the seed maturation period. Using the example of the circumpolar boreal forest, while the joint probability of a mast year and a late-season fire will make this type of event rare (we estimate P = 0.1), nonetheless, it would permit a species lacking obvious fire-adapted traits to occasionally establish a widespread and abundant cohort on a large part of the landscape. PMID:25614797

  17. A Comparison Between Late Summer 2012 and 2013 Water Masses, Macronutrients, and Phytoplankton Standing Crops in the Northern Bering and Chukchi Seas

    NASA Astrophysics Data System (ADS)

    Danielson, S. L.; Eisner, L. B.; Ladd, C. A.; Mordy, C. W.; Sousa, L.; Weingartner, T.

    2016-02-01

    Survey data from the northern Bering and Chukchi sea continental shelves in August-September 2012 and 2013 reveal interannual differences in the spatial structure of water masses along with statistically significant differences in thermohaline and chemical properties and phytoplankton communities. We find that the near-bottom Bering-Chukchi Summer Water (BCSW) was more saline in 2012 and Alaskan Coastal Waters (ACW) were warmer in 2013. Both carried higher nutrient concentrations in 2012, supporting a larger chlorophyll a standing crop biomass that was comprised primarily of small (<10 μm) size class phytoplankton. The location of phytoplankton biomass concentrations and their size compositions reveal linkages between the wind fields, seafloor topography, water masses, and the pelagic production. The horizontal structure of the shelf water masses differed in part because of the August regional wind field, which was more energetic in 2012 but was more persistent in direction in 2013. ACW were found all along the coast from Nunivak Island to Point Barrow in 2012, but in response to the persistent wind of 2013 ACW was not found north of Ledyard Bay. Instead, the 2013 NE Chukchi shelf was flooded with cold and fresh waters derived from ice melt waters (MW) that resided above cold and salty Bering-Chukchi Winter Waters (BCWW). Similarly, in the northern Bering Sea, low-salinity coastal waters from western Alaska were driven offshore to a greater extent in 2013, while in 2012 they were found more confined to shore and more prominently extended northward through Bering Strait. The water mass distributions together with the winds and limited surface current data suggest that the NE Chukchi Alaskan Coastal Current (ACC) was shut down for a time in August and September 2013. Our results have implications for the fate of fresh water, heat, and pelagic production on the Bering-Chukchi shelves.

  18. Summer Programs

    ERIC Educational Resources Information Center

    Schumann, Herbert

    1975-01-01

    Summer employment and participation in professional programs offer the vocational agriculture teacher the unique opportunity to attain excellence in his program. Most administrators appreciate the teacher's efforts and the resulting well-planned and implemented programs. (MW)

  19. Summer Triangle

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    A conspicuous asterism which dominates the northern sky during summer, comprising the bright stars Vega (α Lyrae, apparent magnitude 0.03), Deneb (α Cygni, apparent magnitude 1.25) and Altair (α Aquilae, apparent magnitude 0.76). Vega, by far the most brilliant star in the northern summer sky, is also the brightest to pass overhead (within 13° of the zenith), with the exception of Capella (α Auri...

  20. Late-summer zooplankton community structure, abundance, and distribution in the Hudson Bay system (Canada) and their relationships with environmental conditions, 2003-2006

    NASA Astrophysics Data System (ADS)

    Estrada, Rafael; Harvey, Michel; Gosselin, Michel; Starr, Michel; Galbraith, Peter S.; Straneo, Fiammetta

    2012-08-01

    weakly stratified Arctic-North Atlantic waters coming from southwestern Davis Strait (inflow). In general, the RDA models tested among the HBS regions were very consistent with its general surface circulation pattern for summer conditions in terms of environmental variables and distinct zooplankton assemblages. Overall, zooplankton biomass and diversity indices (H‧, J‧, and S) were lower in the most stratified environment (i.e., HB) than in the deeper (FB) and more dynamic (HS) regions. The results of this work clearly show that the spatial differentiation and structure of the zooplankton communities are strongly influenced by the hydrodynamic conditions in the HBS that, trough their actions on temperature, salinity, stratification, mixing conditions and depth strata, lead to the spatial differentiation of these communities.

  1. Evidence of Late-Summer Mating Readiness and Early Sexual Maturation in Migratory Tree-Roosting Bats Found Dead at Wind Turbines

    PubMed Central

    Cryan, Paul M.; Jameson, Joel W.; Baerwald, Erin F.; Willis, Craig K. R.; Barclay, Robert M. R.; Snider, E. Apple; Crichton, Elizabeth G.

    2012-01-01

    Understanding animal mating systems is an important component of their conservation, yet the precise mating times for many species of bats are unknown. The aim of this study was to better understand the details and timing of reproductive events in species of bats that die most frequently at wind turbines in North America, because such information can help inform conservation strategies. We examined the reproductive anatomy of hoary bats (Lasiurus cinereus), eastern red bats (L. borealis), and silver-haired bats (Lasionycteris noctivagans) found dead beneath industrial-scale wind turbines to learn more about when they mate. We evaluated 103 L. cinereus, 18 L. borealis, and 47 Ln. noctivagans from wind energy facilities in the United States and Canada. Histological analysis revealed that most male L. cinereus and L. borealis, as well as over half the Ln. noctivagans examined had sperm in the caudae epididymides by late August, indicating readiness to mate. Testes regression in male hoary bats coincided with enlargement of seminal vesicles and apparent growth of keratinized spines on the glans penis. Seasonality of these processes also suggests that mating could occur during August in L. cinereus. Spermatozoa were found in the uterus of an adult female hoary bat collected in September, but not in any other females. Ovaries of all females sampled had growing secondary or tertiary follicles, indicating sexual maturity even in first-year females. Lasiurus cinereus, L. borealis, and Ln. noctivagans are the only North American temperate bats in which most first-year young of both sexes are known to sexually mature in their first autumn. Our findings provide the first detailed information published on the seasonal timing of mating readiness in these species most affected by wind turbines. PMID:23094065

  2. Evidence of late-summer mating readiness and early sexual maturation in migratory tree-roosting bats found dead at wind turbines

    USGS Publications Warehouse

    Cryan, P.M.; Jameson, J.W.; Baerwald, E.F.; Willis, C.K.R.; Barclay, R.M.R.; Snider, E.A.; Crichton, E.G.

    2012-01-01

    Understanding animal mating systems is an important component of their conservation, yet the precise mating times for many species of bats are unknown. The aim of this study was to better understand the details and timing of reproductive events in species of bats that die most frequently at wind turbines in North America, because such information can help inform conservation strategies. We examined the reproductive anatomy of hoary bats (Lasiurus cinereus), eastern red bats (L. borealis), and silver-haired bats (Lasionycteris noctivagans) found dead beneath industrial-scale wind turbines to learn more about when they mate. We evaluated 103 L. cinereus, 18 L. borealis, and 47 Ln. noctivagans from wind energy facilities in the United States and Canada. Histological analysis revealed that most male L. cinereus and L. borealis, as well as over half the Ln. noctivagans examined had sperm in the caudae epididymides by late August, indicating readiness to mate. Testes regression in male hoary bats coincided with enlargement of seminal vesicles and apparent growth of keratinized spines on the glans penis. Seasonality of these processes also suggests that mating could occur during August in L. cinereus. Spermatozoa were found in the uterus of an adult female hoary bat collected in September, but not in any other females. Ovaries of all females sampled had growing secondary or tertiary follicles, indicating sexual maturity even in first-year females. Lasiurus cinereus, L. borealis, and Ln. noctivagans are the only North American temperate bats in which most first-year young of both sexes are known to sexually mature in their first autumn. Our findings provide the first detailed information published on the seasonal timing of mating readiness in these species most affected by wind turbines.

  3. Evidence of late-summer mating readiness and early sexual maturation in migratory tree-roosting bats found dead at wind turbines.

    PubMed

    Cryan, Paul M; Jameson, Joel W; Baerwald, Erin F; Willis, Craig K R; Barclay, Robert M R; Snider, E Apple; Crichton, Elizabeth G

    2012-01-01

    Understanding animal mating systems is an important component of their conservation, yet the precise mating times for many species of bats are unknown. The aim of this study was to better understand the details and timing of reproductive events in species of bats that die most frequently at wind turbines in North America, because such information can help inform conservation strategies. We examined the reproductive anatomy of hoary bats (Lasiurus cinereus), eastern red bats (L. borealis), and silver-haired bats (Lasionycteris noctivagans) found dead beneath industrial-scale wind turbines to learn more about when they mate. We evaluated 103 L. cinereus, 18 L. borealis, and 47 Ln. noctivagans from wind energy facilities in the United States and Canada. Histological analysis revealed that most male L. cinereus and L. borealis, as well as over half the Ln. noctivagans examined had sperm in the caudae epididymides by late August, indicating readiness to mate. Testes regression in male hoary bats coincided with enlargement of seminal vesicles and apparent growth of keratinized spines on the glans penis. Seasonality of these processes also suggests that mating could occur during August in L. cinereus. Spermatozoa were found in the uterus of an adult female hoary bat collected in September, but not in any other females. Ovaries of all females sampled had growing secondary or tertiary follicles, indicating sexual maturity even in first-year females. Lasiurus cinereus, L. borealis, and Ln. noctivagans are the only North American temperate bats in which most first-year young of both sexes are known to sexually mature in their first autumn. Our findings provide the first detailed information published on the seasonal timing of mating readiness in these species most affected by wind turbines.

  4. Late summer distribution and stoichiometry of dissolved N, Si and P in the Southern Ocean near Heard and McDonald Islands on the Kerguelen Plateau

    NASA Astrophysics Data System (ADS)

    Chase, Z.; Bowie, A. R.; Blain, S.; Holmes, T.; Rayner, M.; Sherrin, K.; Tonnard, M.; Trull, T. W.

    2016-12-01

    The Kerguelen plateau in the Southern Indian Ocean is a naturally iron-fertilised region surrounded by iron-limited, High Nutrient Low Chlorophyll waters. The Heard Earth Ocean Biosphere Interaction (HEOBI) project sampled waters south of the Polar Front in the vicinity of Heard and McDonald Islands (HIMI) in January and February 2016. Fe fertilised waters over the plateau generally exhibited high phytoplankton biomass and photosynthetic competency (as in previous studies and satellite observations), but interestingly, phytoplankton biomass was low near HIMI, though photosynthetic competency was high. In plateau waters away from HIMI, silicic acid (Si) concentrations were strongly depleted in surface waters, averaging 3 μM, while nitrate concentrations were close to 25 μM. Relative to the remnant winter water, this represents an average seasonal drawdown of 32 μM Si and only 8 μM nitrate. Though absolute drawdown was lower at an HNLC reference site south of Heard Island, the drawdown ratio was similarly high (∆Si: ∆N 4-5). The average N:P drawdown ratio was 12, typical for a diatom-dominated system (Weber and Deutsch 2010). N:P drawdown was positively correlated with Si drawdown, perhaps indicative of an impact of Fe on both seasonal Si drawdown and diatom N:P uptake (Price 2005). In the well-mixed, shallow waters (< 200 m) around HIMI nutrient concentrations were elevated, with no surface nutrient depletion. Nutrient concentrations near the islands were generally consistent with input from vertical mixing of the regional nutrient profile. However, N* values (N* = N - P*16) near the islands were anomalously low (-5 to -7) relative to the regional nutrient profile (N* 3). Subsurface minima in N* (as low as -6) were observed just below the pycnocline at several plateau stations. If negative N* values here are indicative of intense remineralisation of P-rich organic matter, and possible preferential remineralisation of P (Blain et al. 2015), these observations

  5. Summer Opportunities.

    ERIC Educational Resources Information Center

    Winds of Change, 2002

    2002-01-01

    This directory describes 24 summer internships and cooperative education programs for college students, especially in the science, engineering, and technology fields. A few programs are specifically for American Indians, minority groups, or college-bound high school students. Program entries include a brief description, skills and background…

  6. Pilgrim Summer.

    ERIC Educational Resources Information Center

    Trenouth, Peter

    1986-01-01

    Relates the experiences of a teacher's summer working as an "Englishman" on the "Mayflower" II, focusing on questions asked by tourists such as "Where are the other two ships?" Considering the misperceptions of history demonstrated by both young and old Americans, reflects that perhaps there was no "golden…

  7. Summer Skies

    ERIC Educational Resources Information Center

    Science Scope, 2005

    2005-01-01

    During the evening hours of the summer of 2005, there will be numerous opportunities to observe several of the brighter planets as they move along their respective orbits, overtaking and passing one another, performing a planetary dance with the choreography set to orbital speeds. With the exception of Mars, the visible planets will all be in the…

  8. Summer Camp.

    ERIC Educational Resources Information Center

    Burns, Maxine; And Others

    Government regulation of children's summer camps, particularly involving health and safety standards, is discussed in a series of brief interviews with camp directors and representatives of camp associations. Transcribed from the National Public Radio weekly broadcast, "Options in Education," the program includes a lengthy montage of…

  9. Summer Programs.

    ERIC Educational Resources Information Center

    Toussaint, Isabella H.

    An intensive 6-week summer readiness program held in the Beaver Area School District, Beaver, Pennsylvania, developed linguistic facility among 15 preschool children. Daily activities included discussion, picture study, creative arts, field trips, developing experience charts, and other nonlanguage arts activities. A combined experiential,…

  10. Summer Journal.

    ERIC Educational Resources Information Center

    Evansville-Vanderburgh School Corp., IN.

    This student activity book is intended for junior high or high school students. Originally written to be used in a summer television course, the material can be adapted to a regular class situation. The wide variety of materials are relevant to courses in reading, literature, composition, speech, psychology, and social studies. The book includes…

  11. Summer Camp.

    ERIC Educational Resources Information Center

    Pfisterer, Bill

    About 50 participants and 8 supervisors attended the Summer Camp. Visitors were encouraged and parents often came to see what their kids were doing. Before arriving at camp, the students learned how important balancing the supplies was when loading the boats. On the way to camp, students studied the: (1) landmarks so that they could find their way…

  12. Summer Skies

    ERIC Educational Resources Information Center

    Science Scope, 2005

    2005-01-01

    During the evening hours of the summer of 2005, there will be numerous opportunities to observe several of the brighter planets as they move along their respective orbits, overtaking and passing one another, performing a planetary dance with the choreography set to orbital speeds. With the exception of Mars, the visible planets will all be in the…

  13. Fish distribution studies near N Reactor, Summer 1983

    SciTech Connect

    Dauble, D.D.; Page, T.L.

    1984-06-01

    This report summarizes field studies that were initiated in July 1983 to provide estimates of the relative distribution of late-summer outmigrant juvenile salmonids and juvenile resident fish upstream of the N Reactor 009 Outfall. Chinook salmon are among the fish species most sensitive to thermal effects, and impacts to the juvenile outmigrant populations are of particular concern to state and federal regulatory and fisheries management agencies. Therefore, the distribution studies were conducted from late July through September, a period when high ambient river temperatures and low river flows make these salmonid populations most susceptible to thermal effects. In addition, data were not available on the spatial distribution of outmigrant juvenile chinook salmon in late summer. Information on the relative distribution of resident fish populations was also gathered. Previous studies of midstream distribution of juvenile resident fish were limited to a description of ichthyoplankton populations (Beak Consultants, Inc. 1980 Page et al. 1982), and no data were available on vertical or horizontal distribution of juvenile resident fish species near N Reactor. Relative densities and spatial distribution estimates of juvenile salmonid and resident fish species will be used in conjunction with laboratory thermal effects studies (Neitzel et al. 1984) and with plume characterization studies (Ecker et al. 1983) to assess potential impacts of thermal discharge on fish populations near N Reactor.

  14. Late-summer Martian Dust Storm

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This is an image of Mars taken from orbit by the Mars Reconnaissance Orbiter's Mars Color Imager (MARCI). The Red Planet's polar ice-cap is in the middle of the image. Captured in this image is a 37,000 square-kilometer (almost 23,000 miles) dust storm that moved counter-clockwise through the Phoenix landing site on Oct 11, 2008, or Sol 135 of the mission.

    Viewing this image as if it were the face of a clock, Phoenix is shown as a small white dot, located at about 10 AM. The storm, which had already passed over the landing site earlier in the day, is located at about 9:30 AM.

  15. Reconstructing the Late Pleistocene Southern Ocean biological pump using the vertical gradient of Cd/Ca in planktic and benthic foraminifera

    NASA Astrophysics Data System (ADS)

    Charidemou, Miros; Hall, Ian; Ziegler, Martin

    2015-04-01

    The Southern Ocean is a particularly important region in the global carbon cycle because its wind-driven upwelling regime brings CO2-rich deep waters to the ocean surface. However, outgassing of CO2 to the atmosphere is ultimately determined by the efficiency of the soft-tissue biological pump which transfers carbon back into the deep sea. Biological productivity in the Southern Ocean on glacial-interglacial timescales is thought to be influenced by the availability of iron from terrestrial dust sources (Martin, 1990). However, the exact nature of the relationship between productivity and dust flux is still debated (Ziegler et al., 2013; Martinez-Garcia et al., 2014) and remains unclear for earlier times such as during the Middle Pleistocene Transition (MPT). Changes in the strength of the soft-tissue biological pump can be reconstructed with relative ease by measuring carbon isotopes in planktic and benthic foraminifera and quantifying the vertical gradient between them (Ziegler et al., 2013). Our ultimate aim is to use this technique to reconstruct changes in the biological pump in the Southern Ocean during the MPT, when a sharp rise in dust flux is observed in the sedimentary record (Martinez-Garcia et al., 2011). This will allow us to assess the contribution of changes in the Southern Ocean biological pump to the climatic reorganisation that occurred during the MPT. However, before the Δδ13C record is constructed for the MPT it is vital to confirm that this method is indeed a reliable proxy for the soft-tissue biological pump. Records of Δδ13C can be influenced by changes in the whole ocean inventory of δ13C, changes in circulation and changes in the degree of fractionation between the ocean and the atmosphere. The impact of inventory and circulation changes can be minimised by careful selection of study sites and by targeting foraminifera that live within specific water masses. However, deviations of Δδ13C from the biological signal could certainly

  16. Decapod crustacean larval communities in the Balearic Sea (western Mediterranean): Seasonal composition, horizontal and vertical distribution patterns

    NASA Astrophysics Data System (ADS)

    Torres, Asvin P.; Dos Santos, Antonina; Balbín, Rosa; Alemany, Francisco; Massutí, Enric; Reglero, Patricia

    2014-10-01

    Decapod crustaceans are the main target species of deep water bottom trawl fisheries in the Balearic Sea but little is known about their larval stages. This work focuses on the species composition of the decapod larval community, describing the main spatio-temporal assemblages and assessing their vertical distribution. Mesozooplankton sampling was carried out using depth-stratified sampling devices at two stations located over the shelf break and the mid slope, in the north-western and southern Mallorca in late autumn 2009 and summer 2010. Differences among decapod larvae communities, in terms of composition, adult's habitat such as pelagic or benthic, and distribution patterns were observed between seasons, areas and station. Results showed that for both seasons most species and developmental stages aggregated within the upper water column (above 75 m depth) and showed higher biodiversity in summer compared to late autumn. Most abundant species were pelagic prawns (e.g., Sergestidae) occurring in both seasons and areas. The larval assemblages' distributions were different between seasonal hydrographic scenarios and during situations of stratified and non-stratified water column. The vertical distribution patterns of different larval developmental stages in respect to the adult's habitat were analyzed in relation to environmental variables. Fluorescence had the highest explanatory power. Four clearly different vertical patterns were identified: two corresponding to late autumn, which were common for all the main larval groups and other two in summer, one corresponding to larvae of coastal benthic and the second to pelagic species larvae.

  17. Experimental and natural vertical transmission of West Nile virus by California Culex (Diptera: Culicidae) mosquitoes.

    PubMed

    Nelms, Brittany M; Fechter-Leggett, Ethan; Carroll, Brian D; Macedo, Paula; Kluh, Susanne; Reisen, William K

    2013-03-01

    Culex (Diptera: Culicidae) mosquitoes, the primary summer vectors of West Nile virus (family Flaviviridae, genus Flavivirus, WNV), also may serve as overwintering reservoir hosts. Detection of WN viral RNA from larvae hatched from eggs deposited by infected females during late summer and fall may provide evidence for the vertical passage of WNV to overwintering cohorts. To determine whether vertical transmission to the overwintering generation occurs in populations of Culex mosquitoes throughout California, larvae from naturally infected females were tested by family for WN viral RNA by real-time quantitative reverse transcription-polymerase chain reaction during August through October 2011. Viral RNA was detected in 34 of 934 Culex tarsalis Coquillett and Cx. pipiens complex females that laid viable egg rafts. From these egg rafts, first-instar larvae from nine families tested positive, yielding an overall field vertical transmission rate of 26% (n = 34). To determine whether the WNV may be lost transtadially during development to the adult stage, first-instar larvae and adult progeny from experimentally infected Cx. pipiens complex females were assessed for the presence and quantity of WN viral RNA. Most (approximately 75%) WNV infections were lost from positive families during larval development to the adult stage. In field and laboratory studies, only infected mothers with mean cycle threshold scores < or = 20 vertically transmitted WNV to larval progeny, adult progeny, or both. In summary, vertical transmission of WNV was detected repeatedly in naturally infected Culex mosquitoes collected throughout California during late summer and fall, with females having high titered infections capable of passing WNV onto their progeny destined for overwintering.

  18. Indian Summer

    SciTech Connect

    Galindo, E.

    1997-08-01

    This paper focuses on preserving and strengthening two resources culturally and socially important to the Shoshone-Bannock Indian Tribe on the Fort Hall Reservation in Idaho; their young people and the Pacific-Northwest Salmon. After learning that salmon were not returning in significant numbers to ancestral fishing waters at headwater spawning sites, tribal youth wanted to know why. As a result, the Indian Summer project was conceived to give Shoshone-Bannock High School students the opportunity to develop hands-on, workable solutions to improve future Indian fishing and help make the river healthy again. The project goals were to increase the number of fry introduced into the streams, teach the Shoshone-Bannock students how to use scientific methodologies, and get students, parents, community members, and Indian and non-Indian mentors excited about learning. The students chose an egg incubation experiment to help increase self-sustaining, natural production of steelhead trout, and formulated and carried out a three step plan to increase the hatch-rate of steelhead trout in Idaho waters. With the help of local companies, governmental agencies, scientists, and mentors students have been able to meet their project goals, and at the same time, have learned how to use scientific methods to solve real life problems, how to return what they have used to the water and land, and how to have fun and enjoy life while learning.

  19. WNS summer surveillance: DATA

    USGS Publications Warehouse

    Ballmann, Anne

    2017-01-01

    Bats occupying hibernacula during summer months may play an important role in the epidemiology of white-nose syndrome (WNS). For example, bats exposed to viable Pseudogymnoascus destructans (Pd), the causative agent of WNS, in late summer could spread the fungus by transmitting it to other bats or to other locations suitable for establishment of new environmental reservoirs. To explore risks for transmission of Pd during the non-hibernal season, we screened bats using hibernacula between July 18 to August 22, 2012 and associated environmental samples for presence of Pd. Study sites within the eastern United States included six hibernacula known to harbor Pd and two hibernacula in which bats with WNS had not been previously observed. Standard demographic and morphometric data were recorded for bats captured from inside each study site. Sample types evaluated for the presence of Pd included bat wing swabs, guano pellets from individual bats, swabs of hibernaculum walls, and sediments from the hibernaculum floor. Additionally, swabs of various trapping and processing equipment and clothing worn into study sites were evaluated for the presence of Pd.

  20. Next Generation Summer School

    NASA Astrophysics Data System (ADS)

    Eugenia, Marcu

    2013-04-01

    On 21.06.2010 the "Next Generation" Summer School has opened the doors for its first students. They were introduced in the astronomy world by astronomical observations, astronomy and radio-astronomy lectures, laboratory projects meant to initiate them into modern radio astronomy and radio communications. The didactic programme was structure as fallowing: 1) Astronomical elements from the visible spectrum (lectures + practical projects) 2) Radio astronomy elements (lectures + practical projects) 3) Radio communication base (didactic- recreative games) The students and professors accommodation was at the Agroturistic Pension "Popasul Iancului" situated at 800m from the Marisel Observatory. First day (summer solstice day) began with a practical activity: determination of the meridian by measurements of the shadow (the direction of one vertical alignment, when it has the smallest length). The experiment is very instructive and interesting because combines notions of physics, spatial geometry and basic astronomy elements. Next day the activities took place in four stages: the students processed the experimental data obtained on first day (on sheets of millimetre paper they represented the length of the shadow alignments according the time), each team realised its own sun quadrant, point were given considering the design and functionality of these quadrant, the four teams had to mimic important constellations on carton boards with phosphorescent sticky stars and the students, accompanied by the professors took a hiking trip to the surroundings, marking the interest point coordinates, using a GPS to establish the geographical coronations and at the end of the day the students realised a small map of central Marisel area based on the GPS data. On the third day, the students were introduced to basic notions of radio astronomy, the principal categories of artificial Earth satellites: low orbit satellites (LEO), Medium orbit satellites (MEO) and geostationary satellites (GEO

  1. THE VERTICAL

    NASA Technical Reports Server (NTRS)

    Albert, Stephen L.; Spencer, Jeffrey B.

    1994-01-01

    'THE VERTICAL' computer keyboard is designed to address critical factors which contribute to Repetitive Motion Injuries (RMI) (including Carpal Tunnel Syndrome) in association with computer keyboard usage. This keyboard splits the standard QWERTY design into two halves and positions each half 90 degrees from the desk. In order to access a computer correctly. 'THE VERTICAL' requires users to position their bodies in optimal alignment with the keyboard. The orthopaedically neutral forearm position (with hands palms-in and thumbs-up) reduces nerve compression in the forearm. The vertically arranged keypad halves ameliorate onset occurrence of keyboard-associated RMI. By utilizing visually-reference mirrored mylar surfaces adjustable to the user's eye, the user is able to readily reference any key indicia (reversed) just as they would on a conventional keyboard. Transverse adjustability substantially reduces cumulative musculoskeletal discomfort in the shoulders. 'THE VERTICAL' eliminates the need for an exterior mouse by offering a convenient finger-accessible curser control while the hands remain in the vertically neutral position. The potential commercial application for 'THE VERTICAL' is enormous since the product can effect every person who uses a computer anywhere in the world. Employers and their insurance carriers are spending hundreds of millions of dollars per year as a result of RMI. This keyboard will reduce the risk.

  2. Observed changes in the vertical profile of stratopheric nitrous oxide at Thule, Greenland, February - March 1992

    NASA Technical Reports Server (NTRS)

    Emmons, Louisa K.; Reeves, John M.; Shindell, Drew T.; Dezafra, Robert L.

    1994-01-01

    Using a ground-based mm-wave spectrometer, we have observed stratospheric N2O over Thule, Greenland (76.3 N, 68.4 W) during late February and March, 1992. Vertical profiles of mixing ratio ranging from 16 to 50 km were recovered from molecular emission spectra. The profiles of early March show an abrupt increase in the lower-stratosphere N2O mixing ratio similar to the spring-to-summer change associated with the break up of the Antarctic polar vortex. This increase is correlated with changes in potential vorticity, air temperature, and ozone mixing ratio.

  3. Global distribution of summer chlorophyll blooms in the oligotrophic gyres

    NASA Astrophysics Data System (ADS)

    Wilson, Cara; Qiu, Xuemei

    2008-08-01

    Chlorophyll blooms consistently develop in the oligotrophic NE Pacific in late summer, isolated from land masses and sources of higher chlorophyll waters. These blooms are potentially driven by nitrogen fixation, or by vertically migrating phytoplankton, and a better understanding of their ubiquity could improve our estimate of the global nitrogen fixation rate. Here, global SeaWiFS chlorophyll data from 1997 to 2007 are examined to determine if similar blooms occur in other oligotrophic gyres. Our analysis revealed blooms in five other areas. Two of these are regions where blooms have been previously identified: the SW Pacific and off the southern tip of Madagascar. Previously, unnoticed summer blooms were also identified in the NE and SW Atlantic and in a band along 10°S in the Indian Ocean. There is considerable variation in the intensity and frequency of blooms in the different regions, occurring the least frequently in the Atlantic Ocean. The blooms that develop along 10°S in the Indian Ocean are unique in that they are clearly associated with a hydrographic feature, the 10°S thermocline ridge, which explains the bloom within a conventional upwelling scenario. The environment and timing of the blooms, developing in oligotrophic waters in late summer, are conducive to both nitrogen fixers and vertically migrating phytoplankton, which require a relatively stable water column. However, the specific locations of the chlorophyll blooms generally do not coincide with areas of maximum levels of nitrogen fixation or Trichodesmium. The NE Pacific chlorophyll blooms develop in a region with a very high SiO 4/NO 3 ratio, where silicate will not be a limiting nutrient for diatoms. The blooms often develop between eddies, wrapping around the periphery of anti-cyclonic features. However, none of the areas where the blooms develop have particularly high eddy kinetic energy, from either a basin-scale or a mesoscale perspective, suggesting that other factors, such as

  4. Summer Precipitation Patterns Alter Soil Moisture and Carbon Dynamics in a High Elevation Meadow

    NASA Astrophysics Data System (ADS)

    Arnold, C. L.; Berhe, A. A.; Ghezzehei, T. A.

    2014-12-01

    High elevation meadow ecosystems in the Sierra Nevada Mountains and beyond are expected to experience shifts in precipitation patterns over the coming century. While the majority of precipitation falls in the form of rain and snow during the winter months, smaller discrete precipitation events occur during the summer months. These events play an important role in regulating soil moisture dynamics, and biogeochemical cycling of essential elements, including carbon and nitrogen. Preliminary data from a large subalpine meadow in Yosemite National Park, shows a marked decrease in the number of June, July and August pulse events over the last 30 years and a shift toward more smaller events earlier in June and infrequent larger events in July and August. In order to better understand the overall impact these changes have on carbon cycling in meadow ecosystems, detailed studies of current ecosystem functioning is critical. The overall objective of this study is to clarify the spatial and temporal distribution of soil moisture and carbon dioxide fluxes in response to precipitation pulses extending from spring melt through late summer in dry vs. wet meadow sites at a high elevation ecosystem. We found that: (1) Vertical and horizontal heterogeneity in soil moisture is a function of the timing, amount and duration of summer convective precipitation pulse events; (2) The effect of summer convective precipitation pulse events on soil respiration is most heavily influenced by timing between events rather than the magnitude of each event, with more pronounced effects in dry rather than wet meadow locations.

  5. The News, Summer 1999-Summer 2000.

    ERIC Educational Resources Information Center

    Robertson, Trische, Ed.

    2000-01-01

    This document contains five quarterly issues of The News, published Summer 1999 through Summer 2000 by the Community College League of California. The following items are contained in this document: "Grant Writing Success Depends on Resources, Information and Staff,""College Theaters Perform Balancing Act with Community,…

  6. Slithering into Summer

    ERIC Educational Resources Information Center

    Scott, Catherine; Matthews, Catherine

    2012-01-01

    The summer provides a unique opportunity for children to further their interests in science, especially science in the out-of-doors. Once school is out for the summer, there is seemingly unlimited time, with no strict curriculum guidelines to follow. For students with a passion for the out-of-doors, summer science camps and school-based summer…

  7. Summer Correspondence Program.

    ERIC Educational Resources Information Center

    Sulphur Springs Union Elementary School District, Canyon Country, CA.

    THE FOLLOWING IS THE FULL TEXT OF THIS DOCUMENT: The goals of the Summer Correspondence Program have been to help students maintain their basic skills and avoid summer fall-out, as well as to promote parent involvement and positive community relations. After Proposition 13 left no funds for continuation of summer school programs, Sulphur Springs…

  8. Slowing the Summer Slide

    ERIC Educational Resources Information Center

    Smith, Lorna

    2012-01-01

    Research shows that summer slide--the loss of learning over the summer break--is a huge contributor to the achievement gap between low-income students and their higher-income peers. In fact, some researchers have concluded that two-thirds of the 9th-grade reading achievement gap can be explained by unequal access to summer learning opportunities…

  9. Slithering into Summer

    ERIC Educational Resources Information Center

    Scott, Catherine; Matthews, Catherine

    2012-01-01

    The summer provides a unique opportunity for children to further their interests in science, especially science in the out-of-doors. Once school is out for the summer, there is seemingly unlimited time, with no strict curriculum guidelines to follow. For students with a passion for the out-of-doors, summer science camps and school-based summer…

  10. Summer Library Reading Programs

    ERIC Educational Resources Information Center

    Fiore, Carole D.

    2007-01-01

    Virtually all public libraries in the United States provide some type of summer library reading program during the traditional summer vacation period. Summer library reading programs provide opportunities for students of many ages and abilities to practice their reading skills and maintain skills that are developed during the school year. Fiore…

  11. Summer School: Unfulfilled Promise.

    ERIC Educational Resources Information Center

    Denton, David R.

    This report reviews the research on summer school and demonstrates that summer school makes a difference in students' lives if it is done right. A survey of more than 1,000 schools in the southern United States found that one-third of the responding schools did not offer summer school, many programs being the victims of budget cuts. Of those…

  12. Vertical structure of recent Arctic warming.

    PubMed

    Graversen, Rune G; Mauritsen, Thorsten; Tjernström, Michael; Källén, Erland; Svensson, Gunilla

    2008-01-03

    Near-surface warming in the Arctic has been almost twice as large as the global average over recent decades-a phenomenon that is known as the 'Arctic amplification'. The underlying causes of this temperature amplification remain uncertain. The reduction in snow and ice cover that has occurred over recent decades may have played a role. Climate model experiments indicate that when global temperature rises, Arctic snow and ice cover retreats, causing excessive polar warming. Reduction of the snow and ice cover causes albedo changes, and increased refreezing of sea ice during the cold season and decreases in sea-ice thickness both increase heat flux from the ocean to the atmosphere. Changes in oceanic and atmospheric circulation, as well as cloud cover, have also been proposed to cause Arctic temperature amplification. Here we examine the vertical structure of temperature change in the Arctic during the late twentieth century using reanalysis data. We find evidence for temperature amplification well above the surface. Snow and ice feedbacks cannot be the main cause of the warming aloft during the greater part of the year, because these feedbacks are expected to primarily affect temperatures in the lowermost part of the atmosphere, resulting in a pattern of warming that we only observe in spring. A significant proportion of the observed temperature amplification must therefore be explained by mechanisms that induce warming above the lowermost part of the atmosphere. We regress the Arctic temperature field on the atmospheric energy transport into the Arctic and find that, in the summer half-year, a significant proportion of the vertical structure of warming can be explained by changes in this variable. We conclude that changes in atmospheric heat transport may be an important cause of the recent Arctic temperature amplification.

  13. RHIC VERTICAL AC DIPOLE COMMISSIONING.

    SciTech Connect

    BAI,M.; DELONG,J.; HOFF,L.; PAI,C.; PEGGS,S.; PIACENTINO,J.; OERTER,B.; ODDO,P.; ROSER,T.; SATOGATA,T.; TRBOJEVIC,D.; ZALTSMAN,A.

    2002-06-02

    The RHIC vertical ac dipole was installed in the summer of 2001. The magnet is located in the interaction region between sector 3 and sector 4 common to both beams. The resonant frequency of the ac dipole was first configured to be around half of the beam revolution frequency to act as a spin flipper. At the end of the RHIC 2002 run, the ac dipole frequency was reconfigured for linear optics studies. A 0.35 mm driven betatron oscillation was excited with the vertical ac dipole and the vertical betatron functions and phase advances at each beam position monitor (BPM) around the RHIC yellow ring were measured using the excited coherence. We also recorded horizontal turn-by-turn beam positions at each BPM location to investigate coupling effects. Analysis algorithms and measurement results are presented.

  14. Hydromania: Summer Science Camp Curriculum.

    SciTech Connect

    Moura, Joan

    1995-07-01

    In 1992, Bonneville Power Administration (BPA) and the US Department of Energy (DOE) began a collaborative pilot project with the Portland Parks and Recreation Community Schools Program and others to provide summer science camps to children in Grades 4--6. Camps run two weeks in duration between late June and mid-August. Sessions are five days per week, from 9 a.m. to 3 p.m. In addition to hands-on science and math curriculum, at least three field trips are incorporated into the educational learning experience. The purpose of the BPA/DOE summer camps is to make available opportunities for fun, motivating experiences in science to students who otherwise would have difficulty accessing them. This includes inner city, minority, rural and low income students. Public law 101-510, which Congress passed in 1990, authorizes DOE facilities to establish collaborative inner-city and rural partnership programs in science and math. A primary goal of the BPA summer hands on science camps is to bring affordable science camp experiences to students where they live. It uses everyday materials to engage students` minds and to give them a sense that they have succeeded through a fun hands-on learning environment.

  15. The Measurements of Affinity Constants of Osmptrophs For P and Release Rates of P From Microbial Food Web From Late Summer To Early Winter In The Bay of Villefranche, The NW Mediterranean

    NASA Astrophysics Data System (ADS)

    Tanaka, T.; Rassoulzadegan, F.; Thingstad, T. F.

    Orthophosphate uptake by bacteria and phytoplankton was measured with 32P for wa- ter from the Bay of Villefranche (NW Mediterranean) from September to December 2001. The 32P release rate was measured for waters with different size of micro- bial community. During this period, the thermocline was gradually declined and the vertical mixing started, showing the transition from nutrient depleted to replete pe- riods. Before the vertical mixing started, orthophosphate turnover time ranged from 1 to 5 h. The fraction of orthophosphate uptake was dominated (mean 70%) by the 0.6-2 µm fraction where cyanobacteria biomass was dominant. Based on the theo- retical considerations proposed by Thingstad and Rassoulzadegan (1999), the affinity constants were estimated for bacteria, cyanobacteria and autotrophic nanoflagellates, respectively. They ranged from 0.001 to 0.028 L/nM-P/h for bacteria, from 0.047 to 0.103 L/nM-P/h for cyanobacteria and from 0.002 to 0.032 L/nM-P/h for autotrophic nanoflagellates when 32P turnover time was relatively shorter (<5 h). This may sup- port the previous report in which cyanobacteria were dominant in the primary pro- duction in autumn at the study site. The 32P release rates after the addition of cold chase were always less than 0.5%/h. This release appeared to be from the 0.2-0.6 or 0.6-2 µm fractions. The increase of 32P in the >2 µm fraction suggests P transfer by predation. Virus appeared to not contribute to 32P release from bacteria during the study period. These results indicate long P turnover times within particulate fraction and thus less contribution of P release from microbial food web.

  16. Martian north polar cap summer water cycle

    NASA Astrophysics Data System (ADS)

    Brown, Adrian J.; Calvin, Wendy M.; Becerra, Patricio; Byrne, Shane

    2016-10-01

    A key outstanding question in Martian science is "are the polar caps gaining or losing mass and what are the implications for past, current and future climate?" To address this question, we use observations from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) of the north polar cap during late summer for multiple Martian years, to monitor the summertime water cycle in order to place quantitative limits on the amount of water ice deposited and sublimed in late summer. We establish here for the first time the summer cycle of water ice absorption band signatures on the north polar cap. We show that in a key region in the interior of the north polar cap, the absorption band depths grow until Ls = 120, when they begin to shrink, until they are obscured at the end of summer by the north polar hood. This behavior is transferable over the entire north polar cap, where in late summer regions 'flip' from being net sublimating into net condensation mode. This transition or 'mode flip' happens earlier for regions closer to the pole, and later for regions close to the periphery of the cap. The observations and calculations presented herein estimate that on average a water ice layer ∼70 microns thick is deposited during the Ls = 135-164 period. This is far larger than the results of deposition on the south pole during summer, where an average layer 0.6-6 microns deep has been estimated by Brown et al. (2014) Earth Planet. Sci. Lett., 406, 102-109.

  17. Summer library reading programs.

    PubMed

    Fiore, Carole D

    2007-01-01

    Virtually all public libraries in the United States provide some type of summer library reading program during the traditional summer vacation period. Summer library reading programs provide opportunities for students of many ages and abilities to practice their reading skills and maintain skills that are developed during the school year. Fiore summarizes some of the research in the field and relates it to library programs and usage by students. Several traditional and innovative programs from U.S. and Canadian libraries are described. She concludes with a call for further research related to summer library reading programs.

  18. Sea-ice retreat controls timing of summer plankton blooms in the Eastern Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Janout, Markus A.; Hölemann, Jens; Waite, Anya M.; Krumpen, Thomas; Appen, Wilken-Jon; Martynov, Fedor

    2016-12-01

    Two full-year mooring records of sea-ice, physical, and bio-optical parameters illuminate tight temporal coupling between the retreating seasonal ice edge and the summer phytoplankton bloom on the Laptev Sea shelf. Our records showed no sign of pelagic under-ice blooms despite available nutrients and thinning sea ice in early summer, presumably because stratification had not yet developed. Chlorophyll blooms were detected immediately after the ice retreated in late May 2014 and late July 2015. Despite radically different timing, the blooms were similar in both magnitude and length, interpreted as community-level nutrient limitation. Acoustic backscatter records suggest the delayed 2015 bloom resulted in lower zooplankton abundance, perhaps due to a timing mismatch between ice algal and pelagic blooms and unfavorable thermal conditions. Our observations provide classical examples of ice-edge blooms and further emphasize the complexity of high-latitude shelves and the need to understand vertical mixing processes important for stratification and nutrient fluxes.

  19. Late Mio-Pliocene chemical weathering of the Yulong porphyry Cu deposit in the eastern Tibetan Plateau constrained by goethite (U-Th)/He dating: Implication for Asian summer monsoon

    NASA Astrophysics Data System (ADS)

    Deng, Xiao-Dong; Li, Jian-Wei; Shuster, David L.

    2017-08-01

    Chemical weathering has provided a potentially important feedback between tectonic forcing and climate evolution of the Asian continent, although precise constraints on the timing and history of weathering are only variably documented. Here, we use goethite (U-Th)/He and 4He/3He geochronology to constrain the timing and rates of chemical weathering at the Yulong porphyry Cu deposit on the eastern Tibetan Plateau. Goethite grains have (U-Th)/He ages ranging from 6.73 ± 0.51 to 0.53 ± 0.04 Ma that correlate with independent paleoclimatic proxies inferred from supergene Mn-oxides and loess deposits under variable tectonic regimes and vegetation zones over the southeastern Asia. This correlation indicates that regional climatic conditions, especially monsoonal precipitation, controlled chemical weathering and goethite precipitation in a vast area of southeastern Asia. The goethite ages suggest that the Asian summer monsoon was relatively strong from 7 to 4.6 Ma, but weakened between 4.6 and 4 Ma, and then significantly intensified from 4 to 2 Ma. The precipitation ages of goethites collected along a 100-m-thick weathering profile decrease with depth, and indicate a downward propagation of the weathering front at rates of <6.7, 53.5 ± 10.8, and 4.8 ± 0.6 m/Ma during the intervals of 7-4, 4-2, and 2-0.7 Ma, respectively. The rapid propagation of weathering front during 4-2 Ma was caused by abrupt lowering of the water table, which was possibly related to local surface uplift or reorganization of the river systems in southeastern Tibet during this period.

  20. Summer Harvest in Saratov, Russia

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Russia's Saratov Oblast (province) is located in the southeastern portion of the East-European plain, in the Lower Volga River Valley. Southern Russia produces roughly 40 percent of the country's total agricultural output, and Saratov Oblast is the largest producer of grain in the Volga region. Vegetation changes in the province's agricultural lands between spring and summer are apparent in these images acquired on May 31 and July 18, 2002 (upper and lower image panels, respectively) by the Multi-angle Imaging SpectroRadiometer (MISR).

    The left-hand panels are natural color views acquired by MISR's vertical-viewing (nadir) camera. Less vegetation and more earth tones (indicative of bare soils) are apparent in the summer image (lower left). Farmers in the region utilize staggered sowing to help stabilize yields, and a number of different stages of crop maturity can be observed. The main crop is spring wheat, cultivated under non-irrigated conditions. A short growing season and relatively low and variable rainfall are the major limitations to production. Saratov city is apparent as the light gray pixels on the left (west) bank of the Volga River. Riparian vegetation along the Volga exhibits dark green hues, with some new growth appearing in summer.

    The right-hand panels are multi-angle composites created with red band data from MISR's 60-degree backward, nadir and 60-degree forward-viewing cameras displayed as red, green and blue respectively. In these images, color variations serve as a proxy for changes in angular reflectance, and the spring and summer views were processed identically to preserve relative variations in brightness between the two dates. Urban areas and vegetation along the Volga banks look similar in the two seasonal multi-angle composites. The agricultural areas, on the other hand, look strikingly different. This can be attributed to differences in brightness and texture between bare soil and vegetated land. The chestnut-colored soils in

  1. Summer Harvest in Saratov, Russia

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Russia's Saratov Oblast (province) is located in the southeastern portion of the East-European plain, in the Lower Volga River Valley. Southern Russia produces roughly 40 percent of the country's total agricultural output, and Saratov Oblast is the largest producer of grain in the Volga region. Vegetation changes in the province's agricultural lands between spring and summer are apparent in these images acquired on May 31 and July 18, 2002 (upper and lower image panels, respectively) by the Multi-angle Imaging SpectroRadiometer (MISR).

    The left-hand panels are natural color views acquired by MISR's vertical-viewing (nadir) camera. Less vegetation and more earth tones (indicative of bare soils) are apparent in the summer image (lower left). Farmers in the region utilize staggered sowing to help stabilize yields, and a number of different stages of crop maturity can be observed. The main crop is spring wheat, cultivated under non-irrigated conditions. A short growing season and relatively low and variable rainfall are the major limitations to production. Saratov city is apparent as the light gray pixels on the left (west) bank of the Volga River. Riparian vegetation along the Volga exhibits dark green hues, with some new growth appearing in summer.

    The right-hand panels are multi-angle composites created with red band data from MISR's 60-degree backward, nadir and 60-degree forward-viewing cameras displayed as red, green and blue respectively. In these images, color variations serve as a proxy for changes in angular reflectance, and the spring and summer views were processed identically to preserve relative variations in brightness between the two dates. Urban areas and vegetation along the Volga banks look similar in the two seasonal multi-angle composites. The agricultural areas, on the other hand, look strikingly different. This can be attributed to differences in brightness and texture between bare soil and vegetated land. The chestnut-colored soils in

  2. School Construction Summer Slam

    ERIC Educational Resources Information Center

    Jensen, Richard F.

    2012-01-01

    Every school has a list of renovations, upgrades and repairs that need attention, but many are too distracting and disruptive to carry out during the school year. Often, the best time to address these nagging construction projects is during the summer when students are on break and the campus is quieter. Although these "summer slammers" often are…

  3. Book Your Summer Vacation

    ERIC Educational Resources Information Center

    Texley, Juliana

    2012-01-01

    Summer's the time for teachers to travel, not only physically from the confines of the classroom to exotic places, but vicariously, through the magic of books. Summer adventures help teachers expand their experience and enrich their store of context so that they can offer their students more when school resumes in the fall. That's why each year…

  4. Book Your Summer Vacation

    ERIC Educational Resources Information Center

    Texley, Juliana

    2012-01-01

    Summer's the time for teachers to travel, not only physically from the confines of the classroom to exotic places, but vicariously, through the magic of books. Summer adventures help teachers expand their experience and enrich their store of context so that they can offer their students more when school resumes in the fall. That's why each year…

  5. Under Summer Skies

    ERIC Educational Resources Information Center

    Texley, Juliana

    2009-01-01

    There's no better way to celebrate 2009, the International Year of Astronomy, than by curling up with a good book under summer skies. To every civilization, in every age, the skies inspired imagination and scientific inquiry. There's no better place to start your summer reading than under their influence. Here are a few selections identified by…

  6. Your Best Summer Ever

    ERIC Educational Resources Information Center

    Cleaver, Samantha

    2012-01-01

    "It must be nice to have summers off." Only other teachers know just how short summer is, with much of August devoted to planning for the new school year. This article offers 17 fresh ideas for exploring, making money, and preparing for next year. Plus, a reading list that hits all the marks!

  7. Celebrate Summer with Reading

    ERIC Educational Resources Information Center

    Texley, Juliana

    2007-01-01

    School is out and the summer is full of both official and unofficial holidays that prompt us to enjoy science and the profession of sharing it. As in past years, the reviewers and editors of "NSTA Recommends"--ready and willing to share their enthusiasm for reading with you--have been gathering suggestions for the summer. So along with your beach…

  8. Celebrate Summer with Reading

    ERIC Educational Resources Information Center

    Texley, Juliana

    2007-01-01

    School is out and the summer is full of both official and unofficial holidays that prompt us to enjoy science and the profession of sharing it. As in past years, the reviewers and editors of "NSTA Recommends"--ready and willing to share their enthusiasm for reading with you--have been gathering suggestions for the summer. So along with your beach…

  9. Under Summer Skies

    ERIC Educational Resources Information Center

    Texley, Juliana

    2009-01-01

    There's no better way to celebrate 2009, the International Year of Astronomy, than by curling up with a good book under summer skies. To every civilization, in every age, the skies inspired imagination and scientific inquiry. There's no better place to start your summer reading than under their influence. Here are a few selections identified by…

  10. The summer-fall anticyclonic eddy west of Luzon: Structure and evolution in 2012 and interannual variability

    NASA Astrophysics Data System (ADS)

    Wang, Xia; Fang, Wendong; Chen, Rongyu; Cai, Shuqun

    2017-08-01

    The Conductivity-Temperature-Depth (CTD) and acoustic Doppler current profiler (ADCP) measurements along 18°N off the western Luzon in the South China Sea (SCS), collected during a cruise from August 12-14, 2012, were used to explore the vertical structure of an anticyclonic eddy (AE) during the observational period. Further, the French Archiving, Validation and Interpretation of Satellite Oceanographic data (AVISO) sea level anomaly (SLA) and corresponding anomalous surface geostrophic velocity were used to study the temporal evolution of the AE. The vertical structure of the AE along 18°N in August 2012 showed a trough located near 117.5°E. The AE extended vertically downward and its distinct feature was identifiable to 200 m depth. Seasonal variations of SLA indicate that the AE lasted for 5 months (June to early November), going through the growth and nearly stationary period from mid-June to late August and then propagating westward along 18°N with varying phase speeds and shapes to the continental slope off the southeastern Hainan Island during late September to November. Furthermore, T-S characteristics suggest that the AE was generated off the western Luzon. Interannual variations of the summer (July-September) SLA presented by Empirical Orthogonal Function analysis, indicates that the local circulation was enhanced by the anomalous anticyclonic eddy along 18°N in the years of 2008, 2010, 2012 and 2013 during the period from1993 to 2014.

  11. Vertical migration and nighttime distribution of adult bloaters in Lake Michigan

    USGS Publications Warehouse

    TeWinkel, Leslie M.; Fleischer, Guy W.

    1999-01-01

    The vertical migration and nighttime vertical distribution of adult bloaters Coregonus hoyi were investigated during late summer in Lake Michigan using acoustics simultaneously with either midwater or bottom trawling. Bloaters remained on or near bottom during the day. At night, bloaters were distributed throughout 30-65 m of water, depending on bottom depth. Shallowest depths of migration were not related to water temperature or incident light. Maximum distances of migration increased with increasing bottom depth. Nighttime midwater densities ranged from 0.00 to 6.61 fish/1,000 mA? and decreased with increasing bottom depth. Comparisons of length distributions showed that migrating and nonmigrating bloaters did not differ in size. However, at most sites, daytime bottom catches collected a greater proportion of larger individuals compared with nighttime midwater or bottom catches. Mean target strengths by 5-m strata indicated that migrating bloaters did not stratify by size in the water column at night. Overall, patterns in frequency of empty stomachs and mean digestive state of prey indicated that a portion of the bloater population fed in the water column at night. Bloater diet composition indicated both midwater feeding and bottom feeding. In sum, although a portion of the bloater population fed in the water column at night, bloaters were not limited to feeding at this time. This research confirmed that bloaters are opportunistic feeders and did not fully support the previously proposed hypothesis that bloater vertical migration is driven by the vertically migrating macroinvertebrate the opossom shrimp Mysis relicta.

  12. Building Enrollment in Summer Programs.

    ERIC Educational Resources Information Center

    Child Care Information Exchange, 1994

    1994-01-01

    Presents suggestions from 17 day-care center directors on ways to improve summer enrollment. Suggestions include marketing summer programs early; offering reasonable fees, with reduced fees for low-income families; organizing new or different summer programs; creating a summer camp atmosphere; offering short-term summer programs; and including…

  13. IISME Summer Fellowship Program

    NASA Technical Reports Server (NTRS)

    1998-01-01

    During the summer of 1997, NASA-Ames scientists served as mentors to six teachers who worked as IISME (Industry Initiatives for Science and Math Education) Teacher Fellows over the summer. These six teachers were among 91 IISME Teacher Fellows working at various corporate, government agency, and university sites throughout the San Francisco Bay Area. These NASA-Ames fellowship positions are described in brief. One requirement of the IISME Summer Fellowship program is that teachers develop a personal Action Plan for classroom transfer. These Action Plans are published in abstract form in an annual catalog. I have also attached the abstracts of NASA-Ames teachers.

  14. IISME Summer Fellowship Program

    NASA Technical Reports Server (NTRS)

    1998-01-01

    During the summer of 1997, NASA-Ames scientists served as mentors to six teachers who worked as IISME (Industry Initiatives for Science and Math Education) Teacher Fellows over the summer. These six teachers were among 91 IISME Teacher Fellows working at various corporate, government agency, and university sites throughout the San Francisco Bay Area. These NASA-Ames fellowship positions are described in brief. One requirement of the IISME Summer Fellowship program is that teachers develop a personal Action Plan for classroom transfer. These Action Plans are published in abstract form in an annual catalog. I have also attached the abstracts of NASA-Ames teachers.

  15. Evolution of the Southern Hemisphere Subpolar Middle Atmosphere during Summer and Autumn.

    NASA Astrophysics Data System (ADS)

    Miles, T.; Grose, W. L.; Remsberg, E. E.; Lingenfelser, G.

    1994-03-01

    The evolution of zonal wind and zonal wavenumber one (wave 1) in the Southern Hemisphere subpolar middle atmosphere is described for the period December 1978-May 1979 using temperature and ozone measurements from the Limb Infrared Monitor of the Stratosphere (LIMS) experiment.In late December maximum zonal easterlies of 70 m s1 are observed at 0.1 mb, 60°S. A zonal flow reversal occurs during late February and westerlies subsequently increase to 60-70 m s1 in the upper stratosphere by April-May. LIMS zonal winds are compared with rocketsonde measurements and nadir sounder (derived) winds for summer and autumn. Although quantitative agreement is found at stratospheric levels, substantial discrepancies are evident in the mesosphere, most likely a reflection of sampling and resolution differences in the respective datasets.Stationary and traveling wave 1 temperature disturbances (amplitudes 1-2 K at 60°S) are observed by LIMS during summer. The stationary wave is confined to the lower stratosphere near the level of zero zonal mean wind flow, whereas the traveling wave is prominent in the middle stratosphere, moves west at a rate similar to the zonal-mean wind, and exhibits a vertical-meridional structure similar to a P14 normal mode Rossby wave. A substantial intensification of wave 1 activity occurs during autumn (amplitudes 5-10 K), which is found to be associated with an upward-directed Eliassen-Palm flux near the subpolar tropopause level. Evidence relating wave 1 activity in the lower-middle stratosphere to the occurrence of zonal ozone perturbations of 10%-20% amplitude is presented for summer and autumn.

  16. The Purdue Summer Internship

    ERIC Educational Resources Information Center

    Hamilton, William; And Others

    1976-01-01

    Describes a program in which college agricultural education majors between their junior and senior years are placed with vocational agriculture teachers to gain experience in conducting a summer vocational agriculture program. (HD)

  17. Cashing In on Summer.

    ERIC Educational Resources Information Center

    Instructor, 1980

    1980-01-01

    Suggests ways teachers can use their talents and expertise to create jobs for themselves that supply extra income during the summer. These "moonlighting" ideas include tutoring, giving guided tours, planning weddings, and starting exercise classes. (SJL)

  18. Summer Success Story.

    ERIC Educational Resources Information Center

    Matika, Francis W.

    1994-01-01

    Pennsylvania's Beaver Valley Intermediate Unit built a collaborative 2-week summer academy, opening it to students in the other 14 school districts in the county. Cooperation among all the districts provided students opportunities for expanded learning experiences. (MLF)

  19. Books for Summer Reading.

    ERIC Educational Resources Information Center

    Phi Delta Kappan, 1993

    1993-01-01

    Recommends fine fiction for summer reading, including Nadine Gordimer's "My Son's Story" (1991), Lillian Smith's "Strange Fruit" (1944), Josephine Hart's "Damage" (1991), Jane Smiley's "A Thousand Acres" (1991), and George Eliot's "Middlemarch" (1874). Nonfiction suggestions include Harlan Lane's…

  20. A Summer Camp Assessment.

    ERIC Educational Resources Information Center

    Pratte, Janice L.; DiNardi, Salvatore R.

    1979-01-01

    Reported are the results of a project assessing the impact of a revised Massachusetts sanitary code on 500 summer camps for children. The study compared camp compliances with the proposed regulations to the level of compliance with existing regulations. (BT)

  1. Chemical Physics Summer School

    SciTech Connect

    2002-06-28

    The Gordon Research Conference (GRC) on Chemical Physics Summer School was held at Roger Williams University, Bristol, RI. Emphasis was placed on current unpublished research and discussion of the future target areas in this field.

  2. What controls early or late onset of tropical North Atlantic hurricane season?

    NASA Astrophysics Data System (ADS)

    Zuo, Heng; Li, Tim; Liu, Jia; Peng, Melinda

    2016-06-01

    The occurrence of first hurricane in early summer signifies the onset of an active Atlantic hurricane season. The interannual variation of this hurricane onset date is examined for the period 1979-2013. It is found that the onset date has a marked interannual variation. The standard deviation of the interannual variation of the onset day is 17.5 days, with the climatological mean onset happening on July 23. A diagnosis of tropical cyclone (TC) genesis potential index (GPI) indicates that the major difference between an early and a late onset group lies in the maximum potential intensity (MPI). A further diagnosis of the MPI shows that it is primarily controlled by the local SST anomaly (SSTA). Besides the SSTA, vertical shear and mid-tropospheric relative humidity anomalies also contribute significantly to the GPI difference between the early and late onset groups. It is found that the anomalous warm (cold) SST over the tropical Atlantic, while uncorrelated with the Niño3 index, persists from the preceding winter to concurrent summer in the early (late) onset group. The net surface heat flux anomaly always tends to damp the SSTA, which suggests that ocean dynamics may play a role in maintaining the SSTA in the tropical Atlantic. The SSTA pattern with a maximum center in northeastern tropical Atlantic appears responsible for generating the observed wind and moisture anomalies over the main TC development region. A further study is needed to understand the initiation mechanism of the SSTA in the Atlantic.

  3. Modeling the Frozen-In Anticyclone in the 2005 Arctic Summer Stratosphere

    NASA Technical Reports Server (NTRS)

    Allen, D. R.; Douglass, A. R.; Manney, G. L.; Strahan, S. E.; Krosschell, J. C.; Trueblood, J.

    2010-01-01

    Immediately following the breakup of the 2005 Arctic spring stratospheric vortex, a tropical air mass, characterized by low potential vorticity (PV) and high nitrous oxide (N2O), was advected poleward and became trapped in the easterly summer polar vortex. This feature, known as a "Frozen-In Anticyclone (FrIAC)", was observed in Earth Observing System (EOS) Aura Microwave Limb Sounder (MLS) data to span the potential temperature range from approximately 580 to 1100 K (approximately 25 to 40 km altitude) and to persist from late March to late August 2005. This study compares MLS N2O observations with simulations from the Global Modeling Initiative (GMI) chemistry and transport model, the GEOS-5/MERRA Replay model, and the VanLeer Icosahedral Triangular Advection isentropic transport model to elucidate the processes involved in the lifecycle of the FrIAC which is here divided into three distinct phases. During the "spin-up phase" (March to early April), strong poleward flow resulted in a tight isolated anticyclonic vortex at approximately 70-90 deg N, marked with elevated N2O. GMI, Replay, and VITA all reliably simulted the spin-up of the FrIAC, although the GMI and Replay peak N2O values were too low. The FrIAC became trapped in the developing summer easterly flow and circulated around the polar region during the "anticyclonic phase" (early April to the end of May). During this phase, the FrIAC crossed directly over the pole between the 7th and 14th of April. The VITA and Replay simulations transported the N2O anomaly intact during this crossing, in agreement with MLS, but unrealistic dispersion of the anomaly occurred in the GMI simulation due to excessive numerical mixing of the polar cap. The vortex associated with the FrIAC was apparently resistant to the weak vertical hear during the anticyclonic phase, and it thereby protected the embedded N20 anomaly from stretching. The vortex decayed in late May due to diabatic processes, leaving the N2O anomaly exposed to

  4. Effect of sea-ice melt on inherent optical properties and vertical distribution of solar radiant heating in Arctic surface waters

    NASA Astrophysics Data System (ADS)

    Granskog, Mats A.; Pavlov, Alexey K.; Sagan, Sławomir; Kowalczuk, Piotr; Raczkowska, Anna; Stedmon, Colin A.

    2015-10-01

    The inherent optical properties (IOPs) of Polar Waters (PW) exiting the Arctic Ocean in the East Greenland Current (EGC) and of the inflowing Atlantic waters (AW) in the West Spitsbergen Current (WSC) were studied in late summer when surface freshening due to sea-ice melt was widespread. The absorption and attenuation coefficients in PW were significantly higher than previous observations from the western Arctic. High concentrations of colored dissolved organic matter (CDOM) resulted in 50-60% more heat deposition in the upper meters relative to clearest natural waters. This demonstrates the influence of terrigenous organic material inputs on the optical properties of waters in the Eurasian basin. Sea-ice melt in CDOM-rich PW decreased CDOM absorption, but an increase in scattering nearly compensated for lower absorption, and total attenuation was nearly identical in the sea-ice meltwater layer. This suggests a source of scattering material associated with sea-ice melt, relative to the PW. In the AW, melting sea-ice forms a stratified surface layer with lower absorption and attenuation, than well-mixed AW waters in late summer. It is likely that phytoplankton in the surface layer influenced by sea-ice melt are nutrient limited. The presence of a more transparent surface layer changes the vertical radiant heat absorption profile to greater depths in late summer both in EGC and WSC waters, shifting accumulation of solar heat to greater depths and thus this heat is not directly available for ice melt during periods of stratification.

  5. Vertical constituent transport in the mesosphere

    NASA Technical Reports Server (NTRS)

    Strobel, Darrell F.; Summers, Michael E.; Bevilacqua, Richard M.; Deland, Matthew T.; Allen, Mark

    1987-01-01

    Ground-based microwave spectroscopy measurements of mesospheric CO and H2O vertical mixing ratio profiles are used to infer vertical mixing rates in the upper mesosphere. The CO and H2O data consistently imply vertical eddy diffusion coefficients in the 70- to 85-km region of 100,000-200,000 sq cm/s during spring through summer at midlatidues. Although chemical acceleration of vertical transport is substantial for O and O3, below the mesopause, the divergences of their associated fluxes are modest, with at most a factor of 2 effect on the concentrations of O and O3 for measured variability in gravity wave activity. Comparison of Solar Mesosphere Explorer (SME) O3 data with model results reinforces the conclusions of slow vertical mixing in the upper mesosphere as a consequence of the reduced HO(x) catalytic loss of odd oxygen. The changes in chemical rate constants recommended by Rusch and Eckman (1985), in conjunction with slow vertical mixing, yield good agreement with SME O3 data. The slow vertical mixing deduced in this study is consistent with upper limits obtained from studies of the mesospheric heat budget and could be construed as evidence for an advectively controlled mesosphere. A comparison of the vertical eddy diffusion coefficients for momentum stresses, constituent transport, and heat transport suggests that the eddy Prandtl number must be of order 10.

  6. Vertical constituent transport in the mesosphere

    NASA Astrophysics Data System (ADS)

    Strobel, Darrell F.; Summers, Michael E.; Bevilacqua, Richard M.; Deland, Matthew T.; Allen, Mark

    1987-06-01

    Ground-based microwave spectroscopy measurements of mesospheric CO and H2O vertical mixing ratio profiles are used to infer vertical mixing rates in the upper mesosphere. The CO and H2O data consistently imply vertical eddy diffusion coefficients in the 70- to 85-km region of 100,000-200,000 sq cm/s during spring through summer at midlatidues. Although chemical acceleration of vertical transport is substantial for O and O3, below the mesopause, the divergences of their associated fluxes are modest, with at most a factor of 2 effect on the concentrations of O and O3 for measured variability in gravity wave activity. Comparison of Solar Mesosphere Explorer (SME) O3 data with model results reinforces the conclusions of slow vertical mixing in the upper mesosphere as a consequence of the reduced HO(x) catalytic loss of odd oxygen. The changes in chemical rate constants recommended by Rusch and Eckman (1985), in conjunction with slow vertical mixing, yield good agreement with SME O3 data. The slow vertical mixing deduced in this study is consistent with upper limits obtained from studies of the mesospheric heat budget and could be construed as evidence for an advectively controlled mesosphere. A comparison of the vertical eddy diffusion coefficients for momentum stresses, constituent transport, and heat transport suggests that the eddy Prandtl number must be of order 10.

  7. Understanding the influence of predation on introduced fishes on juvenile salmonids in the Columbia River Basin: Closing some knowledge gaps. Late summer and fall diet and condition of smallmouth bass, walleye, and channel catfish in the middle Columbia River, USA. Interim Report of Research 2011.

    USGS Publications Warehouse

    Rose, Brien P.; Hansen, Gabriel S.; Weaver,; Ayers,; Van Dyke, Erick S.; Mesa, Matthew G.

    2012-01-01

    American shad Alosa sapidissima in the middle Columbia River (MCR)—a high energy food available in the summer and fall—may be contributing to the increased growth and enhanced condition of nonnative piscivores. To test this hypothesis we quantified the late summer and autumn diets of smallmouth bass Micropterus dolomieu, walleye Sander vitreus, and channel catfish Ictalurus punctatus in the three lowermost reservoirs on the Columbia River (Bonneville [BON], The Dalles [TDA], and John Day [JDA]). The diet of smallmouth bass (SMB) was fairly similar among reservoirs, with crustaceans (52–82%) and fish (13–38%) being the dominant prey groups by percent mass. Cottidae were usually the dominant fish prey in the diet of SMB at all areas and the contribution of juvenile shad ranged from 0–8.2%. Fish (mostly Cyprinidae and Cottidae) were always the dominant prey item for walleye (WAL) at all areas and at all times, ranging from 70–100% of their diet by mass. Juvenile American shad composed from 10–27% (by mass) of the diet of walleye, depending on area and month. For channel catfish (CHC), the most common prey items consumed were crustaceans (20%–80% by mass) and unidentified items (30%–80%). Fish represented a relatively small component (< 4%) of their diet. We also evaluated the condition of SMB and WAL by determining relative weights (Wr) and hepatosomatic indices (HSI). Mean Wr for SMB greater than 300 mm ranged from 0.89 to 0.94 depending on area and month and showed a significant increase from August to September for fish in BON only. Overall, mean Wr of WAL was similar at all areas, ranging from 0.89–0.91, and increased significantly from September to mid-October and November for fish in TDA only. Overall, mean HSI of SMB ranged from 1.18 to 1.48, did not differ between fish in different reservoirs, and increased significantly from September to mid-October and November for fish from the lower JDA only. Mean HSI of WAL was significantly higher in

  8. Juvenile groundfish habitat in Kachemak Bay, Alaska, during late summer

    USGS Publications Warehouse

    Abookire, Alisa A.; Piatt, J.F.; Norcross, Brenda L.

    2001-01-01

    We investigated the habitat of juvenile groundfishes in relation to depth, water temperature, and salinity in Kachemak Bay, Alaska. Stations ranging in depth from 10 to 70 m and with sand or mud-sand substrates were sampled with a small-meshed beam trawl in August-September of 1994 to 1999. A total of 8,201 fishes were captured, comprising at least 52 species. Most fishes (91%) had a total length 5% of the total catch) were flathead sole Hippoglossoides elassodon, slim sculpin Radulinus asprellus, Pacific halibut Hippoglossus stenolepis, and arrowtooth flounder Atheresthes stomias. Depth accounted for most of the spatial variability in juvenile groundfish abundance, and neither temperature nor salinity was correlated with fish abundance. Juvenile groundfishes concentrated in either shallow (less than or equal to 20 m) or deep (50-70 m) water, with co-occurrence of some species between 30-40 m. Shallow fishes were the rock soles, Pacific halibut, and great sculpin Myoxocephalus polyacanthocephalus. Deep species were flathead sole, slim sculpin, spinycheek starsnout Bathyagonus infraspinatus, rex sole Glyptocephalus zachirus, tadpole sculpin Psychrolutes paradoxus, and whitebarred prickleback Poroclinus rothrocki. This 6-year study provides baseline data on relative abundance and distribution of juvenile groundfishes in Kachemak Bay and may provide a useful tool for predicting the presence of species in similar habitats in other areas of Alaska.

  9. Numerical study of 1998 late summer flood in East Asia

    NASA Astrophysics Data System (ADS)

    Sun, Wen-Yih; Min, Ki-Hong; Chern, Jiun-Dar

    2011-02-01

    The Purdue Regional Model (PRM) is applied to study the evolution of regional climate and weather systems during the heavy precipitation over Korea and China between 30 July and 18 August 1998. The results show that heavy rainfall along the Mei-yu and Changma front was due to the combination of: (1) an anomalous 850 hPa subtropical high, (2) a stronger baroclinicity around 40°N over eastern Asia and a low pressure located to the north of the front, and (3) an excessive evaporation from abnormal wet, warm land. The precipitation ended by 18 August when the subtropical high had retreated and the low pressure in Mongolia moved away from Asia continent. The model reproduced in great detail the observed baroclinic waves to the north, subtropical high and low-level jet to the south, and the front with heavy precipitation extending from southern China, and the Korean peninsula to Japan. High correlations are found for mass, momentum, and moisture fields between model simulation and the European Center for Medium Range Weather Forecast (ECMWF) reanalysis for the 20-day means.

  10. NASA Captures Images of a Late Summer Flare [detail

    NASA Image and Video Library

    2017-09-27

    On Aug. 24, 2014, the sun emitted a mid-level solar flare, peaking at 8:16 a.m. EDT. NASA's Solar Dynamics Observatory captured images of the flare, which erupted on the left side of the sun. Solar flares are powerful bursts of radiation. Harmful radiation from a flare cannot pass through Earth's atmosphere to physically affect humans on the ground, however -- when intense enough -- they can disturb the atmosphere in the layer where GPS and communications signals travel. This close-up of a moderate flare on Aug. 24, 2014, shows light in the 131 and 171 Angstrom wavelengths. The former wavelength, usually colorized in teal, highlights the extremely hot material of a flare. The latter, usually colorized in gold, highlights magnet loops in the sun's atmosphere. To see how this event may affect Earth, please visit NOAA's Space Weather Prediction Center at spaceweather.gov, the U.S. government's official source for space weather forecasts, alerts, watches and warnings. This flare is classified as an M5 flare. M-class flares are ten times less powerful than the most intense flares, called X-class flares. Credit: NASA/Goddard/SDO NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

  11. NASA Captures Images of a Late Summer Flare

    NASA Image and Video Library

    2017-09-27

    On Aug. 24, 2014, the sun emitted a mid-level solar flare, peaking at 8:16 a.m. EDT. NASA's Solar Dynamics Observatory captured images of the flare, which erupted on the left side of the sun. Solar flares are powerful bursts of radiation. Harmful radiation from a flare cannot pass through Earth's atmosphere to physically affect humans on the ground, however -- when intense enough -- they can disturb the atmosphere in the layer where GPS and communications signals travel. To see how this event may affect Earth, please visit NOAA's Space Weather Prediction Center at spaceweather.gov, the U.S. government's official source for space weather forecasts, alerts, watches and warnings. This flare is classified as an M5 flare. M-class flares are ten times less powerful than the most intense flares, called X-class flares. Credit: NASA/Goddard/SDO NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

  12. The Forest, Part 4: Late Summer and Fall

    ERIC Educational Resources Information Center

    Johnson, Elfriede Nemetz

    1973-01-01

    Briefly describes the ecology of a deciduous forest, and suggests activities for observing and appreciating the changes that occur during the Fall. Simple experiments relating to mosses and lichens are outlined. (JR)

  13. Evaporation Duct Occurrences in the Northeast Atlantic during Late Summer.

    DTIC Science & Technology

    1980-09-01

    near 100%, decreasing rapidly in the first few meters to ambient values which depend on varying meteorological conditions. The decrease of hu~midity...Z*) and is a measure of the strength of the evaporation duct. AMBIENT RELATIVE t HlUMIDITY UJ UJ 9 9 EVAPORATION I- 100% 4EVAPORATION DUCT HEIGHT...infrared imagery, 3 August, III-- (Tf’. I7s *N II Me A6A p40V tip Figure 30. M P v’isual imager, 23 August, 22 .1 34. Figiire 31. EMP infrared imagen , 23

  14. The Forest, Part 4: Late Summer and Fall

    ERIC Educational Resources Information Center

    Johnson, Elfriede Nemetz

    1973-01-01

    Briefly describes the ecology of a deciduous forest, and suggests activities for observing and appreciating the changes that occur during the Fall. Simple experiments relating to mosses and lichens are outlined. (JR)

  15. My Summer Vacation

    ERIC Educational Resources Information Center

    Galus, Pamela

    2010-01-01

    In this article, a science teacher from the Midwest reflects on her summer vacation to the Gulf of Mexico. She felt that this vacation would help improve her teaching about the environmental problems in the gulf and elsewhere. After all, anyone can show photos of oil-laden birds and dead sea turtles and read news clips of a distant place, but to…

  16. Summer Opportunities for Students.

    ERIC Educational Resources Information Center

    Winds of Change, 2003

    2003-01-01

    Eleven summer internships, work experience programs, research opportunities, and courses are described. Some offer stipends. Some are specifically for American Indian, minority, disadvantaged, or disabled students in high school or college. Most are in science or engineering related fields. Each entry contains a brief program description,…

  17. Three-Dimensional Summer.

    ERIC Educational Resources Information Center

    Hoffman, Carl

    1997-01-01

    Sponsored by the Appalachian Regional Commission, the Oak Ridge National Laboratory's annual Summer Science Honors Academy is a hands-on experience in science for secondary school students and teachers from throughout Appalachia. The program inspires students to pursue scientific careers and provides teachers with ways to integrate…

  18. Summer Employment for Youth.

    ERIC Educational Resources Information Center

    Jeppson, David L.; Hammer, Fran

    1992-01-01

    This article describes the Summer Work Experience Program developed by 3 agencies in Dallas, Texas, for students (ages 14-18) with visual impairments. The article describes student training; expectations for employees; attitudes of students, parents, and employers; and problems encountered. (JDD)

  19. Use Your Summer Wisely

    ERIC Educational Resources Information Center

    Vick, Julie Miller; Furlong, Jennifer S.

    2007-01-01

    Academics welcome summer with a collective sigh of relief. Finally they can get to those tasks that are nearly impossible to accomplish during a busy academic year: working on that manuscript, completing the revisions on an article, learning the new laboratory technique from the colleague across the hall. However, those going on the job market in…

  20. Summer Study Abroad.

    ERIC Educational Resources Information Center

    Cohen, Gail A., Ed.

    This catalog describes summer study abroad programs around the world for students of college age and up. The included information was obtained from surveys conducted by the Institute of International Education in September 1978. The catalog contains programs of interest to the pre-college student who wants to improve his language skills before…

  1. 2016 SUMMER BLAST PICNIC

    NASA Image and Video Library

    2016-06-09

    MARSHALL SPACE FLIGHT CENTER DIRECTOR TODD MAY CASTS HIS BALLOT IN THE HOMEMADE ICE CREAM CONTEST DURING THE GREAT EXCHANGE SUMMER BLAST SOCIAL, PRESENTED JUNE 9 BY THE MARSHALL EXCHANGE. THE EXCHANGE IS A NON-APPROPRIATED-FUND ACTIVITY THAT AIMS TO CONTRIBUTE TO THE WELFARE, EFFICIENCY AND MORALE OF MARSHALL TEAM MEMBERS, OTHER GOVERNMENT PERSONNEL, RETIRED NASA EMPLOYEES AND THEIR FAMILIES.

  2. Books for Summer Reading.

    ERIC Educational Resources Information Center

    Phi Delta Kappan, 1992

    1992-01-01

    Advises administrators to use their summers to relax and recharge their intellectual batteries. Reading suggestions include Edith Wharton's "House of Mirth," Charlotte Perkins Gilman's "The Yellow Wallpaper," Amy Tan's "Joy Luck Club," China Achebe's "Things Fall Apart," Paule Marshall's "The Chosen…

  3. Books for Summer Reading.

    ERIC Educational Resources Information Center

    [Editors

    2001-01-01

    Teachers and education professors suggest various nonfiction and fiction books for summer reading enjoyment, from Robert Putnam's "Bowling Alone," C.A. Bowers's "Let Them Eat Data," and Larry McMurtry's "Roads: Driving America's Great Highways" to Kent Hauf's "Plainsong, J.M. Coetzee's "Disgrace," and Michael Cunningham's "The Hours." (MLH)

  4. Books for Summer Reading.

    ERIC Educational Resources Information Center

    [Editors

    2001-01-01

    Teachers and education professors suggest various nonfiction and fiction books for summer reading enjoyment, from Robert Putnam's "Bowling Alone," C.A. Bowers's "Let Them Eat Data," and Larry McMurtry's "Roads: Driving America's Great Highways" to Kent Hauf's "Plainsong, J.M. Coetzee's "Disgrace," and Michael Cunningham's "The Hours." (MLH)

  5. International Summer Programs.

    ERIC Educational Resources Information Center

    Cox, June

    1979-01-01

    The article describes five summer programs for gifted and talented students offered internationally. The programs outlined are workshops in the publication arts, a study of humanistic development; computer science, writing, and photography workshops; a language study; a historical/social study of English history; and a workshop on photography,…

  6. Summer Youth Forestry Institute

    ERIC Educational Resources Information Center

    Roesch, Gabrielle E.; Neuffer, Tamara; Zobrist, Kevin

    2013-01-01

    The Summer Youth Forestry Institute (SYFI) was developed to inspire youth through experiential learning opportunities and early work experience in the field of natural resources. Declining enrollments in forestry and other natural resource careers has made it necessary to actively engage youth and provide them with exposure to careers in these…

  7. A Flying Summer Camp

    ERIC Educational Resources Information Center

    Mercurio, Frank X.

    1975-01-01

    Describes a five-day summer camp which provided 12 children, ages 9-14, with a complete flying experience. The training consisted of ground school and one hour actual flying time, including the basics of aircraft control and a flight prepared and executed by the students. (MLH)

  8. Use Your Summer Wisely

    ERIC Educational Resources Information Center

    Vick, Julie Miller; Furlong, Jennifer S.

    2007-01-01

    Academics welcome summer with a collective sigh of relief. Finally they can get to those tasks that are nearly impossible to accomplish during a busy academic year: working on that manuscript, completing the revisions on an article, learning the new laboratory technique from the colleague across the hall. However, those going on the job market in…

  9. Summer by the Book

    ERIC Educational Resources Information Center

    Texley, Judiana

    2005-01-01

    Teachers are usually avid readers, but the pressures of the school year often prevent the sort of thoughtful professional development that a good book can provide. That's why a summer reading list is such a great option, to refresh and renew the scientist within. At the National Science Teachers Association (NSTA), a group of teachers works all…

  10. Waunakee's Summer Science Program.

    ERIC Educational Resources Information Center

    O'Neil, J. Peter

    1981-01-01

    Describes Waunakee Community School's six-week Summer Science Program for students entering the seventh grade. Students are selected for this science enrichment program on the basis of interest, ability, and maturity. Program content includes wetlands, forests, prairies, and animals, concluding with a camping trip. (DS)

  11. 1968 ABC Summer Program.

    ERIC Educational Resources Information Center

    Kerr, Frances M.; Russell, Valerie E.

    A talent development project at Mount Holyoke College, part of A Better Chance (ABC)-Independent Schools Talent Search program, was offered during the summer of 1968 to 71 disadvantaged high school students from 13 states. Major aims of the program were to help these students with college potential to strengthen their academic skills and…

  12. Summer Options for Teenagers.

    ERIC Educational Resources Information Center

    Ware, Cindy

    This guide to more than 1,000 summer programs for teenagers encompasses recreational and academic programs sponsored by colleges, universities, independent schools, foundations, museums, nonprofit organizations, and for-profit businesses. Every program listed accepts students age 13-18; some programs also accept participants older or younger.…

  13. Books for Summer Reading.

    ERIC Educational Resources Information Center

    Phi Delta Kappan, 1991

    1991-01-01

    To help replenish educators' supply of ideas, "Kappan" editors suggest several books for summer reading, including many noncurrent titles not specifically on education such as Peter Novick's "That Noble Dream," Joy Kogawa's "Obasan," Zora Neale Hurston's "Their Eyes Were Watching God," Kate Chopin's "The Awakening," Willa Cather's "My Antonia,"…

  14. Summer Learning That Sticks

    ERIC Educational Resources Information Center

    Browne, Daniel

    2017-01-01

    A new RAND Corporation study shows that voluntary summer programs can benefit children from low-income families, particularly those with high attendance. Programs studied in five school districts had several elements in common: a mix of academics and enrichment activities, certified teachers, small class sizes, full-day programming provided five…

  15. My Summer Vacation

    ERIC Educational Resources Information Center

    Galus, Pamela

    2010-01-01

    In this article, a science teacher from the Midwest reflects on her summer vacation to the Gulf of Mexico. She felt that this vacation would help improve her teaching about the environmental problems in the gulf and elsewhere. After all, anyone can show photos of oil-laden birds and dead sea turtles and read news clips of a distant place, but to…

  16. Summer Reading That Inspires

    ERIC Educational Resources Information Center

    Texley, Juliana

    2012-01-01

    Why did you decide on science as a career? For many, it was the inspiration of a mentor or model--an explorer who could communicate excitement and a sense of adventure to others. During the school year, teachers take on that role of motivator for students. But as they recharge over summer break, it is great to treat themselves again to the stories…

  17. Books for Summer Reading.

    ERIC Educational Resources Information Center

    Phi Delta Kappan, 1996

    1996-01-01

    Suggests several novels for educators' summer reading enjoyment, including classics by Robert Pirsig, Robertson Davies, John Steinbeck, Albert Camus, and Charles Dickens. Educators might also read Alex Kotlowitz's "There Are No Children Here" (Doubleday, 1991) and Sharon Quint's "Schooling Homeless Children" (Teachers College Press, 1994) to gain…

  18. Books for Summer Reading.

    ERIC Educational Resources Information Center

    Phi Delta Kappan, 1992

    1992-01-01

    Advises administrators to use their summers to relax and recharge their intellectual batteries. Reading suggestions include Edith Wharton's "House of Mirth," Charlotte Perkins Gilman's "The Yellow Wallpaper," Amy Tan's "Joy Luck Club," China Achebe's "Things Fall Apart," Paule Marshall's "The Chosen…

  19. Books for Summer Reading.

    ERIC Educational Resources Information Center

    Phi Delta Kappan, 1995

    1995-01-01

    Recommends many books for summer reading enjoyment, concentrating on historical and contemporary fiction. Different cultures clash in William T. Vollman's "Fathers and Crows" and John Demos's adventuresome "Unredeemed Captive." Other suggestions: "Snow Falling on Cedar Mountain" (David Gutterman) and "Foxfire" (Joyce Carol Oates). For professional…

  20. Superheroes and Summer Reading.

    ERIC Educational Resources Information Center

    Meyer, Ron; Buckner, Joyce

    1980-01-01

    To combat summer learning loss among remedial readers, teachers and consultants in the Omaha, Nebraska, Title I program designed a series of comic-book reading units and mailed them to students' homes. Parents were pleased with the project and it appeared that less reading skill had been lost by September. (SJL)

  1. Summer Youth Forestry Institute

    ERIC Educational Resources Information Center

    Roesch, Gabrielle E.; Neuffer, Tamara; Zobrist, Kevin

    2013-01-01

    The Summer Youth Forestry Institute (SYFI) was developed to inspire youth through experiential learning opportunities and early work experience in the field of natural resources. Declining enrollments in forestry and other natural resource careers has made it necessary to actively engage youth and provide them with exposure to careers in these…

  2. Summer Study Abroad.

    ERIC Educational Resources Information Center

    Cohen, Gail A., Ed.

    This catalog describes summer study abroad programs around the world for students of college age and up. The included information was obtained from surveys conducted by the Institute of International Education in September 1978. The catalog contains programs of interest to the pre-college student who wants to improve his language skills before…

  3. Books for Summer Reading.

    ERIC Educational Resources Information Center

    Phi Delta Kappan, 1991

    1991-01-01

    To help replenish educators' supply of ideas, "Kappan" editors suggest several books for summer reading, including many noncurrent titles not specifically on education such as Peter Novick's "That Noble Dream," Joy Kogawa's "Obasan," Zora Neale Hurston's "Their Eyes Were Watching God," Kate Chopin's "The Awakening," Willa Cather's "My Antonia,"…

  4. Three-Dimensional Summer.

    ERIC Educational Resources Information Center

    Hoffman, Carl

    1997-01-01

    Sponsored by the Appalachian Regional Commission, the Oak Ridge National Laboratory's annual Summer Science Honors Academy is a hands-on experience in science for secondary school students and teachers from throughout Appalachia. The program inspires students to pursue scientific careers and provides teachers with ways to integrate…

  5. Books for Summer Reading.

    ERIC Educational Resources Information Center

    Phi Delta Kappan, 1996

    1996-01-01

    Suggests several novels for educators' summer reading enjoyment, including classics by Robert Pirsig, Robertson Davies, John Steinbeck, Albert Camus, and Charles Dickens. Educators might also read Alex Kotlowitz's "There Are No Children Here" (Doubleday, 1991) and Sharon Quint's "Schooling Homeless Children" (Teachers College Press, 1994) to gain…

  6. Summer Learning That Sticks

    ERIC Educational Resources Information Center

    Browne, Daniel

    2017-01-01

    A new RAND Corporation study shows that voluntary summer programs can benefit children from low-income families, particularly those with high attendance. Programs studied in five school districts had several elements in common: a mix of academics and enrichment activities, certified teachers, small class sizes, full-day programming provided five…

  7. International Summer Programs.

    ERIC Educational Resources Information Center

    Cox, June

    1979-01-01

    The article describes five summer programs for gifted and talented students offered internationally. The programs outlined are workshops in the publication arts, a study of humanistic development; computer science, writing, and photography workshops; a language study; a historical/social study of English history; and a workshop on photography,…

  8. Temporal variability of vertical export flux at the DYFAMED time-series station (Northwestern Mediterranean Sea)

    NASA Astrophysics Data System (ADS)

    Heimbürger, Lars-Eric; Lavigne, Héloïse; Migon, Christophe; D'Ortenzio, Fabrizio; Estournel, Claude; Coppola, Laurent; Miquel, Juan-Carlos

    2013-12-01

    high vertical export flux. This resulted from the combination of particularly strong summer stratification and the erosion of the thermocline by wind gales in late summer, with the subsequent release of the organic particulates accumulated above the pycnocline (Martín and Miquel, 2010).

  9. EOS Microwave Limb Sounder Observations of 'Frozen-in' Anticyclonic Air in Arctic Summer

    NASA Technical Reports Server (NTRS)

    Manney, G. L.; Livesey, N. J.; Jimenez, C. J.; Pumphrey, H. C.; Santee, M. L.; MacKenzie, I. A.; Waters, J. W.

    2006-01-01

    A previously unreported phenomenon, a 'frozen-in' anticyclone (FrIAC) after the 2005 Arctic spring vortex breakup, was discovered in Earth Observing System (EOS) Microwave Limb Sounder (MLS) long-lived trace gas data. A tongue of low-latitude (high-N2O, low-H2O) air was drawn into high latitudes and confined in a tight anticyclone, then advected intact in the summer easterlies through late August. A similar feature in O3 disappeared by early April as a result of chemical processes. The FrIAC was initially advected upright at nearly the same speed at all levels from approx.660 to 1300 K (approx.25-45 km); increasing vertical wind shear after early June tilted the FrIAC and weakened it at higher levels. The associated feature in PV disappeared by early June; transport calculations fail to reproduce the remarkable persistence of the FrIAC, suggesting deficiencies in summer high-latitude winds. The historical PV record suggests that this phenomenon may have occurred several times before. The lack of a persistent signature in O3 or PV, along with its small size and rapid motion, make it unlikely that a FrIAC could have been reliably identified without hemispheric daily longlived trace gas profiles such as those from EOS MLS.

  10. Two distinct mechanisms on East Asian surface temperature variability during summer

    NASA Astrophysics Data System (ADS)

    Yeh, Sang-Wook; Won, Yujin; Yeo, Sae-Rim; Yim, Bo Young

    2016-04-01

    The surface air temperature (SAT) in East Asia was examined in order to find global scale versus local scale factors that affected its variability during the summer (June-July-August). It was found that there exist a distinguished sub-seasonal variation, showing remarkable differences in its variability between early summer (June) and late summer (July and August). In particular, we pay attention to the variability of Korean SAT. This study revealed that Korean SAT during early and late summer is affected by different principal modes of SAT over East Asia domain. In particular, there was a significant warming trend in the Korean SAT during early summer, which was primarily influenced by a global warming trend that manifested in East Asia. Meanwhile, there exists the local scale variability of the Korean SAT, which is independent from the global warming signal. During late summer, on the other hand, the SAT variability in Korea was not significantly influenced by a warming trend, although the warming signal still accounts for majority of the SAT variance over East Asia. Instead, Korean SAT during late summer appears to be closely related to the atmospheric variability originated from the western tropical sea surface temperature (SST) forcing. These results implied that the East Asian SAT variability during early and late summer has different sources.

  11. Late results.

    PubMed

    Daly, B D

    1999-08-01

    Pneumonectomy is performed for a number of benign and malignant conditions. It is most commonly performed for lung cancer. Adjuvant and neoadjuvant protocols have increased the number of these operations being performed and the long-term results are improving. Pneumonectomy may also be performed for metastases to lung and for mesothelioma with encouraging results. Some bronchial adenomas require pneumonectomy. Treatment of resistant mycobacteria or the complications of tuberculosis frequently require pneumonectomy. Late bronchopleural fistulae, esophagopleural fistulae, and empyema may occur.

  12. Making Summer Count: How Summer Programs Can Boost Children's Learning

    ERIC Educational Resources Information Center

    McCombs, Jennifer Sloan; Augustine, Catherine; Schwartz, Heather; Bodilly, Susan; McInnis, Brian; Lichter, Dahlia; Cross, Amanda Brown

    2012-01-01

    During summer vacation, many students lose knowledge and skills. By the end of summer, students perform, on average, one month behind where they left off in the spring. Participation in summer learning programs should mitigate learning loss and could even produce achievement gains. Indeed, educators and policymakers increasingly promote summer…

  13. Making Summer Count: How Summer Programs Can Boost Children's Learning

    ERIC Educational Resources Information Center

    McCombs, Jennifer Sloan; Augustine, Catherine; Schwartz, Heather; Bodilly, Susan; McInnis, Brian; Lichter, Dahlia; Cross, Amanda Brown

    2012-01-01

    During summer vacation, many students lose knowledge and skills. By the end of summer, students perform, on average, one month behind where they left off in the spring. Participation in summer learning programs should mitigate learning loss and could even produce achievement gains. Indeed, educators and policymakers increasingly promote summer…

  14. Summer 2014 Pathways Report

    NASA Technical Reports Server (NTRS)

    Hand, Zachary

    2014-01-01

    Over the summer I had the exciting opportunity to work for NASA at the Kennedy Space Center as a Mission Assurance Engineering intern. When I was offered a position in mission assurance for the Safety and Mission Assurance directorate's Launch Services Division, I didn't really know what I would be doing, but I knew it would be an excellent opportunity to learn and grow professionally. In this report I will provide some background information on the Launch Services Division, as well as detail my duties and accomplishments during my time as an intern. Additionally, I will relate the significance of my work experience to my current academic work and future career goals. This report contains background information on Mission Assurance Engineering, a description of my duties and accomplishments over the summer of 2014, and relates the significance of my work experience to my school work and future career goals. It is a required document for the Pathways program.

  15. Summer South Polar Cap

    NASA Technical Reports Server (NTRS)

    2004-01-01

    13 April 2004 The martian south polar residual ice cap is composed mainly of frozen carbon dioxide. Each summer, a little bit of this carbon dioxide sublimes away. Pits grow larger, and mesas get smaller, as this process continues from year to year. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a view of a small portion of the south polar cap as it appeared in mid-summer in January 2004. The dark areas may be places where the frozen carbon dioxide contains impurities, such as dust, or places where sublimation of ice has roughened the surface so that it appears darker because of small shadows cast by irregularities in the roughened surface. The image is located near 86.9oS, 7.6oW. The image covers an area about 3 km (1.9 mi) across. Sunlight illuminates the scene from the upper left.

  16. The summer of 1974

    NASA Astrophysics Data System (ADS)

    Flatté, Stanley M.

    2003-04-01

    In the early 1970s, Garrett and Munk summarized oceanographers' knowledge of ocean internal waves in a reference statistical spectrum. Almost at the same time, Hardin and Tappert introduced the parabolic equation into ocean acoustics. In the summer of 1974, Flatté and Tappert [J. Acoust. Soc. Am. 58, 1151-1159 (1975)] helped bring these two ideas together by simulating 100-Hz acoustic propagation through an approximate version of the Garrett-Munk spectrum to a range of 100 km, in order to help understand the effects caused by internal waves on acoustic fluctuations. The history of that summer will be discussed, along with a movie made at that time. The influence of that work on subsequent developments will be discussed.

  17. The Summer of Supermoons

    NASA Astrophysics Data System (ADS)

    McCarter, Tricia

    2014-08-01

    Two perigee full moons appeared in the sky this summer, one on 12 July and one on 10 August, and a third will appear on 9 September. Perigee is the moment the Moon passes closest to the Earth. Although the appearance of these moons is not extraordinary—they occur, on average, between four and six times per year—the 10 August moon was the brightest and closest of all the perigee moons that will appear this year.

  18. [Allergies in summer].

    PubMed

    Pelkonen, Anna

    2011-01-01

    Summertime allergic symptoms include sneezing, running and stuffy nose, burning and itching eyes and wheal formation on the skin. In Finland the problems in allergic people during the spring and summer are mainly associated with the pollen of birch, alder, hazel, grasses and mugwort. The efficacy of drugs used for the treatment of seasonal allergic rhinitis varies. Treatment is usually initiated with a non-sedating antihistamine, and nasally sprayable corticosteroids can be used if the symptoms are more severe.

  19. Manufacturing Dissent: Labor Revitalization, Union Summer and Student Protest

    ERIC Educational Resources Information Center

    Van Dyke, Nella; Dixon, Marc; Carlon, Helen

    2007-01-01

    During the late 1990s, college students across the United States mobilized around labor issues. Our research explores whether this explosion of student protest activity was generated, in part, by concerted efforts of the AFL-CIO through its Union Summer college student internship program. A statistical analysis of factors influencing the location…

  20. Manufacturing Dissent: Labor Revitalization, Union Summer and Student Protest

    ERIC Educational Resources Information Center

    Van Dyke, Nella; Dixon, Marc; Carlon, Helen

    2007-01-01

    During the late 1990s, college students across the United States mobilized around labor issues. Our research explores whether this explosion of student protest activity was generated, in part, by concerted efforts of the AFL-CIO through its Union Summer college student internship program. A statistical analysis of factors influencing the location…

  1. Martian north pole summer temperatures: dirty water ice.

    PubMed

    Kieffer, H H; Chase, S C; Martin, T Z; Miner, E D; Palluconi, F D

    1976-12-11

    Broadband thermal and reflectance observations of the martian north polar region in late summer yield temperatures for the residual polar cap near 205 K with albedos near 43 percent. The residual cap and several outlying smaller deposits are water ice with included dirt; there is no evidence for any permanent carbon dioxide polar cap.

  2. Martian north pole summer temperatures - Dirty water ice

    NASA Technical Reports Server (NTRS)

    Kieffer, H. H.; Martin, T. Z.; Chase, S. C., Jr.; Miner, E. D.; Palluconi, F. D.

    1976-01-01

    Broadband thermal and reflectance observations of the Martian north polar region in late summer yield temperatures for the residual polar cap near 205 K with albedos near 43 percent. The residual cap and several outlying smaller deposits are water ice with included dirt; there is no evidence for any permanent carbon dioxide polar cap.

  3. Martian north pole summer temperatures - Dirty water ice

    NASA Technical Reports Server (NTRS)

    Kieffer, H. H.; Martin, T. Z.; Chase, S. C., Jr.; Miner, E. D.; Palluconi, F. D.

    1976-01-01

    Broadband thermal and reflectance observations of the Martian north polar region in late summer yield temperatures for the residual polar cap near 205 K with albedos near 43 percent. The residual cap and several outlying smaller deposits are water ice with included dirt; there is no evidence for any permanent carbon dioxide polar cap.

  4. Goddard Summer Interns: Alejandro Arambula

    NASA Image and Video Library

    Alejandro Arambula is an aerospace engineering student at M.I.T. and a 2011 summer intern in Goddard's Propulsion Lab. This summer he is working with his mentor Khary Parker in building a test asse...

  5. Arctic Summer Ice Processes

    NASA Technical Reports Server (NTRS)

    Holt, Benjamin

    1999-01-01

    The primary objective of this study is to estimate the flux of heat and freshwater resulting from sea ice melt in the polar seas. The approach taken is to examine the decay of sea ice in the summer months primarily through the use of spaceborne Synthetic Aperture Radar (SAR) imagery. The improved understanding of the dynamics of the melt process can be usefully combined with ice thermodynamic and upper ocean models to form more complete models of ice melt. Models indicate that more heat is absorbed in the upper ocean when the ice cover is composed of smaller rather than larger floes and when there is more open water. Over the course of the summer, floes disintegrate by physical forcing and heating, melting into smaller and smaller sizes. By measuring the change in distribution of floes together with open water over a summer period, we can make estimates of the amount of heating by region and time. In a climatic sense, these studies are intended to improve the understanding of the Arctic heat budget which can then be eventually incorporated into improved global climate models. This work has two focus areas. The first is examining the detailed effect of storms on floe size and open water. A strong Arctic low pressure storm has been shown to loosen up the pack ice, increase the open water concentration well into the pack ice, and change the distribution of floes toward fewer and smaller floes. This suggests episodic melting and the increased importance of horizontal (lateral) melt during storms. The second focus area is related to an extensive ship-based experiment that recently took place in the Arctic called Surface Heat Budget of the Arctic (SHEBA). An icebreaker was placed purposely into the older pack ice north of Alaska in September 1997. The ship served as the base for experimenters who deployed extensive instrumentation to measure the atmosphere, ocean, and ice during a one-year period. My experiment will be to derive similar measurements (floe size, open

  6. Arctic Summer Ice Processes

    NASA Technical Reports Server (NTRS)

    Holt, Benjamin

    1999-01-01

    The primary objective of this study is to estimate the flux of heat and freshwater resulting from sea ice melt in the polar seas. The approach taken is to examine the decay of sea ice in the summer months primarily through the use of spaceborne Synthetic Aperture Radar (SAR) imagery. The improved understanding of the dynamics of the melt process can be usefully combined with ice thermodynamic and upper ocean models to form more complete models of ice melt. Models indicate that more heat is absorbed in the upper ocean when the ice cover is composed of smaller rather than larger floes and when there is more open water. Over the course of the summer, floes disintegrate by physical forcing and heating, melting into smaller and smaller sizes. By measuring the change in distribution of floes together with open water over a summer period, we can make estimates of the amount of heating by region and time. In a climatic sense, these studies are intended to improve the understanding of the Arctic heat budget which can then be eventually incorporated into improved global climate models. This work has two focus areas. The first is examining the detailed effect of storms on floe size and open water. A strong Arctic low pressure storm has been shown to loosen up the pack ice, increase the open water concentration well into the pack ice, and change the distribution of floes toward fewer and smaller floes. This suggests episodic melting and the increased importance of horizontal (lateral) melt during storms. The second focus area is related to an extensive ship-based experiment that recently took place in the Arctic called Surface Heat Budget of the Arctic (SHEBA). An icebreaker was placed purposely into the older pack ice north of Alaska in September 1997. The ship served as the base for experimenters who deployed extensive instrumentation to measure the atmosphere, ocean, and ice during a one-year period. My experiment will be to derive similar measurements (floe size, open

  7. Summer Migrant Education Administrative Manual.

    ERIC Educational Resources Information Center

    North Carolina State Dept. of Public Instruction, Raleigh.

    This manual helps local education agencies (LEAs) create and develop summer school programs for children of migrant workers in North Carolina. It includes models for summer programs in music, art, vocational education, reading, language arts and math. The manual includes sections on financing, planning, student transportation, summer lunch…

  8. Summer Learning: Accelerating Student Success

    ERIC Educational Resources Information Center

    Pitcock, Sarah; Seidel, Bob

    2015-01-01

    As numerous studies from 1906 on have confirmed, children lose ground in learning if they lack opportunities for building skills over the summer. Nonetheless, summer learning loss comes up but rarely in the national discussion of education reform. By the end of summer, students perform on average one month behind where they left off in the spring.…

  9. Summer Learning: Accelerating Student Success

    ERIC Educational Resources Information Center

    Pitcock, Sarah; Seidel, Bob

    2015-01-01

    As numerous studies from 1906 on have confirmed, children lose ground in learning if they lack opportunities for building skills over the summer. Nonetheless, summer learning loss comes up but rarely in the national discussion of education reform. By the end of summer, students perform on average one month behind where they left off in the spring.…

  10. Vertical bounce of two vertically aligned balls

    NASA Astrophysics Data System (ADS)

    Cross, Rod

    2007-11-01

    When a tennis ball rests on top of a basketball and both drop to the floor together, the tennis ball is projected vertically at high speed. A mass-spring model of the impact, as well as air track data, suggest that the tennis ball should be projected at relatively low speed. Measurements of the forces on each ball and the bounce of vertically aligned superballs are used to resolve the discrepancy.

  11. Vertical heat transfer based on direct microstructure measurements in the ice-free Pacific-side Arctic Ocean: the role and impact of the Pacific water intrusion

    NASA Astrophysics Data System (ADS)

    Kawaguchi, Y.; Kikuchi, T.; Inoue, R.

    2014-12-01

    This study quantifies diapycnal mixing and vertical heat transfer in the Pacific side of the Arctic Ocean, where sea-ice cover has disappeared between July and September in the last few decades. We conducted microstructure measurements in the open water region around the Canada Basin from late summer to fall in 2009 and 2010 using RV Mirai. In the study domain, the dissipation rate of turbulent kinetic energy, ɛ, is typically as low level as O(10-10) W kg-1, resulting in vertical heat diffusivity of O(10-7) m2 s-1, which is close to the molecular diffusivity of heat, suggesting comparatively little predominance of mechanical turbulent mixing. An exception is the case at the Barrow Canyon, where the strong baroclinic throughflow generates substantial vertical mixing, producing ɛ >O(10-7) W kg-1, because of the shear flow instability. Meanwhile, in the confluence region, where the warm/salty Pacific water and the cold/fresh Arctic basin water encounter, the micro-temperature profiles revealed a localized enhancement in vertical diffusivity of heat, reaching O(10-5) m2 s-1 or greater. In this region, an intrusion of warm Pacific water creates a horizontally interleaved structure, where the double-diffusive mixing facilitates vertical heat transfer between the intruding Pacific water and the surrounding basin waters.

  12. Vertical axis wind turbines

    DOEpatents

    Krivcov, Vladimir [Miass, RU; Krivospitski, Vladimir [Miass, RU; Maksimov, Vasili [Miass, RU; Halstead, Richard [Rohnert Park, CA; Grahov, Jurij [Miass, RU

    2011-03-08

    A vertical axis wind turbine is described. The wind turbine can include a top ring, a middle ring and a lower ring, wherein a plurality of vertical airfoils are disposed between the rings. For example, three vertical airfoils can be attached between the upper ring and the middle ring. In addition, three more vertical airfoils can be attached between the lower ring and the middle ring. When wind contacts the vertically arranged airfoils the rings begin to spin. By connecting the rings to a center pole which spins an alternator, electricity can be generated from wind.

  13. Improvement of vertical profiles of raindrop size distribution from micro rain radar using 2D video disdrometer measurements

    NASA Astrophysics Data System (ADS)

    Adirosi, E.; Baldini, L.; Roberto, N.; Gatlin, P.; Tokay, A.

    2016-03-01

    A measurement scheme aimed at investigating precipitation properties based on collocated disdrometer and profiling instruments is used in many experimental campaigns. Raindrop size distribution (RSD) estimated by disdrometer is referred to the ground level; the collocated profiling instrument is supposed to provide complementary estimation at different heights of the precipitation column above the instruments. As part of the Special Observation Period 1 of the HyMeX (Hydrological Cycle in the Mediterranean Experiment) project, conducted between 5 September and 6 November 2012, a K-band vertically pointing micro rain radar (MRR) and a 2D video disdrometer (2DVD) were installed close to each other at a site in the historic center of Rome (Italy). The raindrop size distributions collected by 2D video disdrometer are considered to be fairly accurate within the typical sizes of drops. Vertical profiles of raindrop sizes up to 1085 m are estimated from the Doppler spectra measured by the micro rain radar with a height resolution of 35 m. Several issues related to vertical winds, attenuation correction, Doppler spectra aliasing, and range-Doppler ambiguity limit the performance of MRR in heavy precipitation or in convection, conditions that frequently occur in late summer or in autumn in Mediterranean regions. In this paper, MRR Doppler spectra are reprocessed, exploiting the 2DVD measurements at ground to estimate the effects of vertical winds at 105 m (the most reliable MRR lower height), in order to provide a better estimation of vertical profiles of raindrop size distribution from MRR spectra. Results show that the reprocessing procedure leads to a better agreement between the reflectivity computed at 105 m from the reprocessed MRR spectra and that obtained from the 2DVD data. Finally, vertical profiles of MRR-estimated RSDs and their relevant moments (namely median volume diameter and reflectivity) are presented and discussed in order to investigate the

  14. PMSE dependence on long-period vertical motions

    SciTech Connect

    Cho, J.Y.N.; Morley, R.L.

    1995-05-15

    The authors analyze the temporal relationship between PMSE (polar mesosphere summer echoes) and long-period vertical motions using the Poker Flat, Alaska radar data. The results show that the vertical velocity leads PMSE by 90{degrees} to 180{degrees} with a possible upward trend in phase with increasing frequency. They show that this is consistent with the current PMSE theories which depend primarily upon the presence of charged ice aerosols for the enhancement of radar scatter. 23 refs., 2 figs.

  15. Saturn, Approaching Northern Summer

    NASA Image and Video Library

    2016-09-15

    Since NASA's Cassini spacecraft arrived at Saturn in mid-2004, the planet's appearance has changed greatly. The shifting angle of sunlight as the seasons march forward has illuminated the giant hexagon-shaped jet stream around the north polar region, and the subtle bluish hues seen earlier in the mission have continued to fade. Earlier views obtained in 2004 and 2009 (see PIA06077 and PIA11667) demonstrate how drastically the illumination has changed. This view shows Saturn's northern hemisphere in 2016, as that part of the planet nears its northern hemisphere summer solstice in May 2017. Saturn's year is nearly 30 Earth years long, and during its long time there, Cassini has observed winter and spring in the north, and summer and fall in the south. The spacecraft will complete its mission just after northern summer solstice, having observed long-term changes in the planet's winds, temperatures, clouds and chemistry. Cassini scanned across the planet and its rings on April 25, 2016, capturing three sets of red, green and blue images to cover this entire scene showing the planet and the main rings. The images were obtained using Cassini's wide-angle camera at a distance of approximately 1.9 million miles (3 million kilometers) from Saturn and at an elevation of about 30 degrees above the ring plane. The view looks toward the sunlit side of the rings from a sun-Saturn-spacecraft angle, or phase angle, of 55 degrees. Image scale on Saturn is about 111 miles (178 kilometers) per pixel. The exposures used to make this mosaic were obtained just prior to the beginning of a 44-hour movie sequence. http://photojournal.jpl.nasa.gov/catalog/PIA21046

  16. 2003 SOLAS Summer School

    NASA Technical Reports Server (NTRS)

    McGillis, Wade R.

    2003-01-01

    In 2003, the United States provided support for the participation of 18 students, three research assistants, and seven lecturers in the first international Surface Ocean Lower Atmosphere Study (SOLAS) Summer School. The purpose of this school was to introduce graduate students and young researchers to different components of SOLAS research including biogeochemical interactions and feedbacks, exchange processes, and air-sea fluxes. Support was provided through grants from: NASA (contact: Charles Trees); NSF (contact: Anne-Marie Schmoltner); NOAA (contact: Kathy Tedesco); and ONR (contact: Ronald Ferek).

  17. Northern Summer on Titan

    NASA Image and Video Library

    2017-06-14

    NASA's Cassini spacecraft sees bright methane clouds drifting in the summer skies of Saturn's moon Titan, along with dark hydrocarbon lakes and seas clustered around the north pole. Compared to earlier in Cassini's mission, most of the surface in the moon's northern high latitudes is now illuminated by the sun. The image was taken with the Cassini spacecraft narrow-angle camera on June 9, 2017, using a spectral filter that preferentially admits wavelengths of near-infrared light centered at 938 nanometers. Cassini obtained the view at a distance of about 315,000 miles (507,000 kilometers) from Titan. https://photojournal.jpl.nasa.gov/catalog/PIA21615

  18. 2003 SOLAS Summer School

    NASA Technical Reports Server (NTRS)

    McGillis, Wade R.

    2003-01-01

    In 2003, the United States provided support for the participation of 18 students, three research assistants, and seven lecturers in the first international Surface Ocean Lower Atmosphere Study (SOLAS) Summer School. The purpose of this school was to introduce graduate students and young researchers to different components of SOLAS research including biogeochemical interactions and feedbacks, exchange processes, and air-sea fluxes. Support was provided through grants from: NASA (contact: Charles Trees); NSF (contact: Anne-Marie Schmoltner); NOAA (contact: Kathy Tedesco); and ONR (contact: Ronald Ferek).

  19. Using polar mesosphere summer echoes and stratospheric/mesospheric winds to explain summer mesopause jumps in Antarctica

    NASA Astrophysics Data System (ADS)

    Lübken, Franz-Josef; Latteck, Ralph; Becker, Erich; Höffner, Josef; Murphy, Damian

    2017-09-01

    Recent high resolution temperature measurements by resonance lidar occasionally showed a sudden mesopause altitude increase by ∼5 km and an associated mesopause temperature decrease by ∼10 K at Davis (69°S). In this paper we present further observations which are closely related to this 'mesopause jump', namely the increase of mean height of polar mesospheric summer echoes (PMSE) observed by a VHF radar, very strong westward winds in the upper mesosphere measured by an MF radar, and relatively large eastward winds in the stratosphere taken from reanalysis. We present a detailed explanation of mesopause jumps. They occur only when stratospheric winds are moderately eastward and mesospheric winds are strongly westward. Under these conditions, gravity waves with comparatively large eastward phase speeds can pass the stratosphere and propagate to the lower thermosphere because their vertical wavelengths in the mesosphere are rather large which implies enhanced dynamical stability. When finally breaking in the lower thermosphere, these waves drive an enhanced residual circulation that causes a cold and high-altitude mesopause. The conditions for a mesopause jump occur only in the Southern Hemisphere (SH) and are associated with the late breakdown of the polar vortex. Mesopause jumps are primarily, but not only, observed prior and close to solstice. Our study also shows that during the onset of PMSE in the SH, stratospheric zonal winds are still eastward (up to 30 m/s), and that the onset is not closely related to the transition of the stratospheric circulation. Unlike previously published results with polar mesospheric clouds, we find an overall poor correlation between PMSE onset and the date of the vortex breakdown.

  20. Occurrence of human respiratory syncytial virus in summer in Japan.

    PubMed

    Shobugawa, Y; Takeuchi, T; Hibino, A; Hassan, M R; Yagami, R; Kondo, H; Odagiri, T; Saito, R

    2017-01-01

    In temperate zones, human respiratory syncytial virus (HRSV) outbreaks typically occur in cold weather, i.e. in late autumn and winter. However, recent outbreaks in Japan have tended to start during summer and autumn. This study examined associations of meteorological conditions with the numbers of HRSV cases reported in summer in Japan. Using data from the HRSV national surveillance system and national meteorological data for summer during the period 2007-2014, we utilized negative binomial logistic regression analysis to identify associations between meteorological conditions and reported cases of HRSV. HRSV cases increased when summer temperatures rose and when relative humidity increased. Consideration of the interaction term temperature × relative humidity enabled us to show synergistic effects of high temperature with HRSV occurrence. In particular, HRSV cases synergistically increased when relative humidity increased while the temperature was ⩾28·2 °C. Seasonal-trend decomposition analysis using the HRSV national surveillance data divided by 11 climate divisions showed that summer HRSV cases occurred in South Japan (Okinawa Island), Kyushu, and Nankai climate divisions, which are located in southwest Japan. Higher temperature and higher relative humidity were necessary conditions for HRSV occurrence in summer in Japan. Paediatricians in temperate zones should be mindful of possible HRSV cases in summer, when suitable conditions are present.

  1. Site Location Details, Air Pollution Monitoring Equipment Used, Aircraft Flight Path Information, and Deployment Configuration for the DISCOVER-AQ (Deriving Information on Surface Conditions from COlumn and VERtically Resolved Observations Relevant to Air Quality) Field Campaign in Colorado: Summer 2014

    EPA Science Inventory

    For EPA, this Summer 2014, Denver CO, DISCOVER-AQ field research activity focused on assessing Federal Reference Methods (FRMs) and Federal Equivalent Methods (FEMs) for ozone (O3) and Nitrogen Dioxide (NO2), while comparing their operational performance to each other and to smal...

  2. Site Location Details, Air Pollution Monitoring Equipment Used, Aircraft Flight Path Information, and Deployment Configuration for the DISCOVER-AQ (Deriving Information on Surface Conditions from COlumn and VERtically Resolved Observations Relevant to Air Quality) Field Campaign in Colorado: Summer 2014

    EPA Science Inventory

    For EPA, this Summer 2014, Denver CO, DISCOVER-AQ field research activity focused on assessing Federal Reference Methods (FRMs) and Federal Equivalent Methods (FEMs) for ozone (O3) and Nitrogen Dioxide (NO2), while comparing their operational performance to each other and to smal...

  3. Vertical Axis Wind Turbine

    SciTech Connect

    Homicz, Greg

    2002-04-01

    Blade fatigue life is an important element in determining the economic viability of the Vertical-Axis Wind Turbine (VAWT). VAWT-SAL Vertical Axis Wind Turbine- Stochastic Aerodynamic Loads Ver 3.2 numerically simulates the stochastic (random0 aerodynamic loads of the Vertical-Axis Wind Turbine (VAWT) created by the atomspheric turbulence. The program takes into account the rotor geometry, operating conditions, and assumed turbulence properties.

  4. Offset vertical radar profiling

    USGS Publications Warehouse

    Witten, A.; Lane, J.

    2003-01-01

    Diffraction tomography imaging was applied to VRP data acquired by vertically moving a receiving antenna in a number of wells. This procedure simulated a vertical downhole receiver array. Similarly, a transmitting antenna was sequentially moved along a series of radial lines extending outward from the receiver wells. This provided a sequence of multistatic data sets and, from each data set, a two-dimensional vertical cross-sectional image of spatial variations in wave speed was reconstructed.

  5. Vertical fluxes of nitrate in the seasonal nitracline of the Atlantic sector of the Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Randelhoff, Achim; Fer, Ilker; Sundfjord, Arild; Tremblay, Jean-Éric; Reigstad, Marit

    2016-07-01

    This study compiles colocated oceanic observations of high-resolution vertical profiles of nitrate concentration and turbulent microstructure around the Svalbard shelf slope, covering both the permanently ice-free Fram Strait and the pack ice north of Svalbard. The authors present an overview over the seasonal evolution of the distribution of nitrate and its relation to upper ocean stratification. The average upward turbulent diffusive nitrate flux across the seasonal nitracline during the Arctic summer season is derived, with average values of 0.3 and 0.7 mmol m-2 d-1 for stations with and without ice cover, respectively. The increase under ice-free conditions is attributed to different patterns of stratification under sea ice versus open water. The nitrate flux obtained from microstructure measurements lacked a seasonal signal. However, bottle incubations indicate that August nitrate uptake was reduced by more than an order of magnitude relative to the May values. It remains inconclusive whether the new production was limited by an unidentified factor other than NO3- supply in late summer, or the uptake was underestimated by the incubation method.

  6. Vertical structure and seasonal evolution of the cold intermediate layer in the Baltic Proper

    NASA Astrophysics Data System (ADS)

    Stepanova, N. B.

    2017-08-01

    Vertical T,S structure of waters of the cold intermediate layer (CIL) is examined on the base of high-resolution CTD profiles obtained in the Baltic Sea Proper in spring and early-summer periods. Basic elements of the structure of the CIL are identified and possible mechanisms responsible for their formation are suggested. Seasonal evolution of the CIL structure is considered. Its four stages are discussed: formation in early spring; late-spring adjustment; slow summer-time modification; and fall/winter-time washing-out/preconditioning to the next cycle. The mechanisms of mixing and stirring which could be responsible for the observed features of the CIL structure are discussed. It is proposed to consider the Baltic CIL not as a phenomenon which appears during the warm season only, but as a manifestation of a permanently current process of basin-scale water exchange. Further targeted investigations are urged disclosing the role of this exchange in general thermo-haline circulation of the Baltic Sea.

  7. Assessment of Summer 1997 motor gasoline price increase

    SciTech Connect

    1998-05-01

    Gasoline markets in 1996 and 1997 provided several spectacular examples of petroleum market dynamics. The first occurred in spring 1996, when tight markets, following a long winter of high demand, resulted in rising crude oil prices just when gasoline prices exhibit their normal spring rise ahead of the summer driving season. Rising crude oil prices again pushed gasoline prices up at the end of 1996, but a warm winter and growing supplies weakened world crude oil markets, pushing down crude oil and gasoline prices during spring 1997. The 1996 and 1997 spring markets provided good examples of how crude oil prices can move gasoline prices both up and down, regardless of the state of the gasoline market in the United States. Both of these spring events were covered in prior Energy Information Administration (EIA) reports. As the summer of 1997 was coming to a close, consumers experienced yet another surge in gasoline prices. Unlike the previous increase in spring 1996, crude oil was not a factor. The late summer 1997 price increase was brought about by the supply/demand fundamentals in the gasoline markets, rather than the crude oil markets. The nature of the summer 1997 gasoline price increase raised questions regarding production and imports. Given very strong demand in July and August, the seemingly limited supply response required examination. In addition, the price increase that occurred on the West Coast during late summer exhibited behavior different than the increase east of the Rocky Mountains. Thus, the Petroleum Administration for Defense District (PADD) 5 region needed additional analysis (Appendix A). This report is a study of this late summer gasoline market and some of the important issues surrounding that event.

  8. Good Old Summer Time

    NASA Image and Video Library

    2017-07-31

    Saturn's northern hemisphere reached its summer solstice in mid-2017, bringing continuous sunshine to the planet's far north. The solstice took place on May 24, 2017. The Cassini mission is using the unparalleled opportunity to observe changes that occur on the planet as the Saturnian seasons turn. This view looks toward the sunlit side of the rings from about 17 degrees above the ring plane. The image was taken with the Cassini spacecraft wide-angle camera on April 17, 2017 using a spectral filter which preferentially admits wavelengths of near-infrared light centered at 939 nanometers. The view was acquired at a distance of approximately 733,000 miles (1.2 million kilometers) from Saturn. Image scale is 44 miles (70 kilometers) per pixel. https://photojournal.jpl.nasa.gov/catalog/PIA21337

  9. Dunes in Northern Summer

    NASA Image and Video Library

    2017-02-01

    This dune field formed near the base of the North Polar cap. Dunes require a source of loose particulate material to form. The source of the northern dune fields around the polar cap may be from the layers of dusty ice that are eroded by strong polar winds. This image was taken during the Martian northern summer, so there is no frost present on the dunes. The dunes closest to the base of the polar cap are long and parallel, indicating strong winds from the direction of the cap. As they get farther away from the polar cap, they start to form more crescent shaped dunes, called barchan dunes. Repeated observations by HiRISE of dunes like these show measurable changes in some locations. This discovery adds to the growing evidence that there are active processes happening all over the surface of Mars today. http://photojournal.jpl.nasa.gov/catalog/PIA11181

  10. Conducting Summer School in Agriculture

    ERIC Educational Resources Information Center

    Lloyd, Melvin

    1976-01-01

    Course objectives, student competencies, and class session schedules are outlined for two high school vocational agriculture summer courses: Livestock and Livestock Products Evaluation and Agribusiness Leadership Seminar. (MS)

  11. Lack of Evidence for Laboratory and Natural Vertical Transmission of Bluetongue Virus in Culicoides sonorensis (Diptera: Ceratopogonidae).

    PubMed

    Osborne, C J; Mayo, C E; Mullens, B A; McDermott, E G; Gerry, A C; Reisen, W K; MacLachlan, N J

    2015-03-01

    Culicoides sonorensis (Wirth & Jones) is the principal North American vector of bluetongue virus (BTV). BTV infection of livestock is distinctly seasonal (late summer and fall) in temperate regions of the world such as California, which has led to speculation regarding vertical transmission of the virus within the midge vector as a potential mechanism for interseasonal maintenance ("overwintering") of the virus. To evaluate potential vertical transmission of BTV in its midge vector, we fed adult midges BTV-spiked blood and used a BTV-specific quantitative reverse transcriptase polymerase chain reaction assay to evaluate parent, egg, and progeny stages of laboratory-reared C. sonorensis for the presence of viral nucleic acid. Whereas BTV nucleic acid was weakly detected in egg batches of virus-fed female midges, virus was never detected in subsequent progeny stages (larvae, pupae, and F1 generation adults). Similarly, BTV was not detected in pools of larvae collected from the waste-water lagoon of a BTV-endemic dairy farm in northern California during the seasonal period of virus transmission. Collectively, these results indicate that BTV is not readily transmitted vertically in C. sonorensis, and that persistence of the virus in long-lived parous female midges is a more likely mechanism for overwintering of BTV in temperate regions. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America.

  12. Traumatic vertical atlantoaxial dislocation.

    PubMed

    Payer, M; Wetzel, S; Kelekis, A; Jenny, B

    2005-08-01

    We present a case of traumatic vertical atlantoaxial dislocation of 16 millimetres with a fatal outcome. We hypothesize that this extremely rare traumatic vertical atlantoaxial dislocation results from insufficiency of the C1/C2 facet capsules after rupture of the tectorial membrane and the alar ligaments.

  13. Vertical axis windmill

    SciTech Connect

    Campbell, J.S.

    1980-04-08

    A vertical axis windmill is described which involves a rotatable central vertical shaft having horizontal arms pivotally supporting three sails that are free to function in the wind like the main sail on a sail boat, and means for disabling the sails to allow the windmill to be stopped in a blowing wind.

  14. Have a Bearable Summer: '86 Summer Reading Program Planning Manual.

    ERIC Educational Resources Information Center

    Jackson, Mary

    Because studies have found that children can lose a year in their reading skills and motivation during summers, this planning guide suggests ways for librarians to interest children in a summer reading program by appealing to their fascination with bears and teddy bears. The guide is organized chronologically, beginning with a timetable, followed…

  15. Tsunami Summer! 2003 Young Adult Summer Library Program.

    ERIC Educational Resources Information Center

    Alabama Public Library Service, Montgomery.

    This manual is designed to assist public libraries in Alabama with setting up "Tsunami Summer!," a summer program for young adults, i.e., students in grades 6 through 12. The manual contains the following sections: (1) Publicity and Promotion; (2) Working with Schools; (3) Involving the Students, including teen volunteers, teen advisory…

  16. Supplemental Summer Literacy Instruction: Implications for Preventing Summer Reading Loss

    ERIC Educational Resources Information Center

    McDaniel, Sara C.; McLeod, Ragan; Carter, Coddy L.; Robinson, Cecil

    2017-01-01

    Summer reading loss is a prevalent problem that occurs primarily for students who are not exposed to or encouraged to read at home or in summer programs when school is out. This problem prevails among early readers from low-income backgrounds. This study provided 31 six and seven-year-old children with a structured guided reading program through…

  17. Evaluation of a Summer Reading Program to Reduce Summer Setback

    ERIC Educational Resources Information Center

    Johnston, Jessica; Riley, Jessica; Ryan, Carey; Kelly-Vance, Lisa

    2015-01-01

    Summer setback, which is defined as a decline in academic achievement over the summer months, occurs in many academic areas but seems especially problematic in reading. We assessed students from a midwestern parochial school serving predominantly students from a low--socioeconomic status background for their reading achievement before they left…

  18. Laser tracking for vertical control

    NASA Technical Reports Server (NTRS)

    Dunn, Peter; Torrence, Mark; Pavlis, Erricos; Kolenkiewicz, Ron; Smith, David

    1993-01-01

    The Global Laser Tracking Network has provided LAGEOS ranging data of high accuracy since the first MERIT campaign in late 1983 and we can now resolve centimeter-level three dimensional positions of participating observatories at monthly intervals. In this analysis, the station height estimates have been considered separately from the horizontal components, and can be determined by the strongest stations with a formal standard error of 2 mm using eight years of continuous observations. The rate of change in the vertical can be resolved to a few mm/year, which is at the expected level of several geophysical effects. In comparing the behavior of the stations to that predicted by recent models of post-glacial rebound, we find no correlation in this very small effect. Particular attention must be applied to data and survey quality control when measuring the vertical component, and the survey observations are critical components of the geodynamic results. Seasonal patterns are observed in the heights of most stations, and the possibility of secular motion at the level of several millimeters per year cannot be excluded. Any such motion must be considered in the interpretation of horizontal inter-site measurements, and can help to identify mechanisms which can cause variations which occur linearly with time, seasonally, or abruptly.

  19. Secular increase of the total vertical column abundance of carbon monoxide above central Europe since 1950

    NASA Technical Reports Server (NTRS)

    Zander, R.; Demoulin, PH.; Ehhalt, D. H.; Schmidt, U.; Rinsland, C. P.

    1989-01-01

    The secular increase of the total vertical column abundance of carbon monoxide has been derived from sets of infrared solar spectra recorded from an altitude of 3.58 km at the Jungfraujoch Station, Switzerland, in 1950-1951 and in 1985-1987. The results are based on equivalent width measurements of the R3 line of the 1-0 vibration-rotation band of (C-12)(0-16) at 2159.30/cm. The set of 1985-1987 observations indicates a strong seasonal cycle in the total column abundance of CO, with a + or - 25 percent modulation between minimum values in late summer and the maximum values in late winter. Variability on shorter time scales is also present in both the old and recent data sets. The mean cumulative rate of increase of the total column abundance of CO above the Jungfraujoch is found to be (0.85 + or - 0.20) percent/yr between 1950-1951 and 1985-1987. The present findings are compared with trends reported in earlier studies.

  20. Educational Merit of Summer Programs.

    ERIC Educational Resources Information Center

    Miller, Larry E.; Parks, Darrell L.

    1981-01-01

    Advisory committees from the horticultural and agricultural mechanics industries were surveyed to determine the educational merits and criticalness of students acquiring specific experiences available only during the summer months. In horticulture, summer experience was indicated to be essential to 60 (26.1 percent) of the duty/task categories.…

  1. Quality of Summer Teachers Examined

    ERIC Educational Resources Information Center

    Sawchuk, Stephen

    2011-01-01

    A hefty body of evidence documents the phenomenon of "summer learning loss," but consensus on the attributes of effective summer intervention, especially when it comes to access to high-quality teaching for students most at risk of falling behind, is only starting to emerge. Now, though, a handful of districts are beginning to wrestle with the…

  2. Special Handbook: The Summer Scholar

    ERIC Educational Resources Information Center

    Thaler, Pat Koch; Shapiro, Sonya

    1978-01-01

    No longer is summer ushered in with that old "no more lessons, no more books" refrain. There are plenty of vacation learning opportunities--in and around New York, at college campuses, and even abroad--for all age groups. Here is a roundup of this summer's offerings. (Editor)

  3. Reverse Transfer Project, Summer 1986.

    ERIC Educational Resources Information Center

    Reis, Elizabeth

    In 1986, a Reverse Transfer Project was initiated at Moraine Valley Community College (MVCC) in order to promote the summer school attendance at MVCC of "reverse transfer" students (i.e., students who attended another institution during the regular academic year). A mailing, containing a cover letter, informational brochure, summer catalog, and…

  4. Potential impacts of the Arctic on interannual and interdecadal summer precipitation over China

    SciTech Connect

    Li, Yuefeng; Leung, Lai-Yung R.

    2013-02-01

    After the end of the 1970s, there has been a tendency for enhanced summer precipitation over South China and the Yangtze River valley and drought over North China and Northeastern China. Coincidentally, Arctic ice concentration has decreased since the late 1970s, with larger reduction in summer than spring. However, the Arctic warming is more significant in spring than summer, suggesting that spring Arctic conditions could be more important in their remote impacts. This study investigates the potential impacts of the Arctic on summer precipitation in China. The leading spatial patterns and time coefficients of the unfiltered, interannual, and interdecadal precipitation (1960-2008) modes were analyzed and compared using empirical orthogonal function (EOF) analysis, which shows that the first three EOFs can capture the principal precipitation patterns (northern, central and southern patterns) over eastern China. Regression of the Arctic spring and summer temperature onto the time coefficients of the leading interannual and interdecadal precipitation modes shows that interdecadal summer precipitation in China is related to the Arctic spring warming, but the relationship with Arctic summer temperature is weak. Moreover, no notable relationships were found between the first three modes of interannual precipitation and Arctic spring or summer temperatures. Finally, correlations between summer precipitation and the Arctic Oscillation (AO) index from January to August were investigated, which indicate that summer precipitation in China correlates with AO only to some extent. Overall, this study suggests important relationships between the Arctic spring temperature and summer precipitation over China at the interdecadal time scale.

  5. On the linkage between the Asian summer monsoon and tropopause fold activity over the eastern Mediterranean and the Middle East

    NASA Astrophysics Data System (ADS)

    Tyrlis, Evangelos; Å kerlak, Bojan; Sprenger, Michael; Wernli, Heini; Zittis, George; Lelieveld, Jos

    2014-03-01

    A climatology of tropopause folds occurring over the Eastern Mediterranean and the Middle East (EMME) has been established using the ERA-Interim reanalyses for the years 1979-2012. The methodology employs an algorithm that detects folds at grid points where the vertical profile features multiple crossings of the dynamical tropopause and allows their classification according to their vertical extent. Our results confirm the findings of an earlier 1 year climatology that recognized a global "hot spot" of summertime fold activity between the eastern Mediterranean and central Asia, in the vicinity of the subtropical jet. Two distinct maxima of activity are identified over Turkey and Iran-Afghanistan where fold frequency exceeds 25%. Occasionally, medium and deep folds form over the two regions at surprisingly low latitudes. This summertime peak in fold activity diverges from the zonal mean seasonal cycle over the subtropics and is driven by the South Asian Monsoon. Starting in late spring, the EMME is gradually brought under the influence of the zonally asymmetric background state induced by the monsoon. As areas of sharply sloping isentropes develop especially over the eastern Mediterranean and Iran-Afghanistan, subsidence and fold formation are favored. Further investigation of the reanalysis data provided empirical evidence that the monsoon also drives the interannual variability of EMME fold activity. An upward trend in fold activity is identified, especially in May, attributed to the recent advanced monsoon onset and the deepening convective activity throughout summer, which promotes upper-level baroclinicity over the EMME and favors folding.

  6. Leaf morphology and photosynthetic adjustments among deciduous broad-leaved trees within the vertical canopy profile.

    PubMed

    Koike, T; Kitao, M; Maruyama, Y; Mori, S; Lei, T T

    2001-08-01

    Photosynthetic acclimation of deciduous broad-leaved tree species was studied along a vertical gradient within the canopy of a multi-species deciduous forest in northern Japan. We investigated variations in (1) local light regime and CO2 concentration ([CO2]), and (2) morphological (area, thickness and area per mass), biochemical (nitrogen and chlorophyll concentrations) and physiological (light-saturated photosynthetic rate) attributes of leaves of seven major species on three occasions (June, August and October). We studied early successional species, alder (Alnus hirsuta (Spach) Rupr.) and birch (Betula platyphylla var. japonica (Miq.) Hara); gap phase species, walnut (Juglans ailanthifolia Carrière) and ash (Fraxinus mandshurica var. japonica Rupr.); mid-successional species, basswood (Tilia japonica (Miq.) Simonk.) and elm (Ulmus davidiana var. japonica (Rehd.) Nakai); and the late-successional species, maple (Acer mono Bunge). All but maple initiated leaf unfolding from the lower part of the crown. The [CO2] within the vertical profile ranged from 320-350 ppm in the upper canopy to 405-560 ppm near the ground. The lowest and highest ambient [CO2] occurred during the day and during the night, respectively. This trend was observed consistently during the summer, but not when trees were leafless. Chlorophyll concentration was positively related to maximum photosynthetic rate within, but not among, species. Leaf senescence started from the inner part of the crown in alder and birch, but started either in the outer or top portion of the canopy of ash, basswood and maple. Chlorophyll (Chl) to nitrogen ratio in leaves increased with decreasing photon flux density. However, Chl b concentration in all species remained stable until the beginning of leaf senescence. Maximum photosynthetic rates observed in sun leaves of early successional species, gap phase or mid-successional species, and late successional species were 12.5-14.8 micromol m(-2) s(-1), 4.1-7.8 micromol

  7. The Summer Mesopause Region at Davis, Antarctica 2010 - 2012

    NASA Astrophysics Data System (ADS)

    Höffner, J.

    2014-12-01

    In cooperation with the Australian Antarctic Division mesopause temperatures, iron densities and NLC were measured at Davis, 69°S by the mobile Fe-Doppler-Lidar of the IAP. Within 2 years more than 2900 hours of observations have been obtained throughout the season. We will present quasi-continuous measurements of temperature profiles in the southern hemisphere mesopause region during the transition from winter to summer in 2011/2012. In a period of 120 days around solstice we have performed lidar observations for a total of 736 hours. PMSE was simultaneously observed by the nearby Davis-MST Radar. The winter/summer transition is identified by a downward shift of the mesopause which occurs on 8 November 2011. Soon after transition, mesopause heights and temperatures are similar to the northern hemisphere (NH) colatitude summer (88 km, 130 K). Around solstice the Mesopause is elevated for several days by 4-5 km and is colder than typical NH temperatures by 10 K. In this period individual profiles show temperatures as low as 100 K. The occurrence of polar mesosphere summer echoes is closely connected to low temperatures. Below 88 to 90 km and in the main summer season of 2011/2012 temperatures at Davis are generally warmer compared to the NH by 5-15 K, whereas temperatures are generally colder above 90 km. The first NLC observed by the lidar occurred very late in the season close to solstice. Most NLC occurred during a period of comparable warm temperatures and high iron number densities in early January. The late occurrence is in agreement with long term observations by the Davis-Lidar (AAD). The late occurrence is a major difference compared to the co-latitude Andoya, 69° N.

  8. Micromachined electrostatic vertical actuator

    SciTech Connect

    Lee, A.P.; Sommargren, G.E.; McConaghy, C.F.; Krulevitch, P.A.

    1999-10-19

    A micromachined vertical actuator utilizing a levitational force, such as in electrostatic comb drives, provides vertical actuation that is relatively linear in actuation for control, and can be readily combined with parallel plate capacitive position sensing for position control. The micromachined electrostatic vertical actuator provides accurate movement in the sub-micron to micron ranges which is desirable in the phase modulation instrument, such as optical phase shifting. For example, compact, inexpensive, and position controllable micromirrors utilizing an electrostatic vertical actuator can replace the large, expensive, and difficult-to-maintain piezoelectric actuators. A thirty pound piezoelectric actuator with corner cube reflectors, as utilized in a phase shifting diffraction interferometer can be replaced with a micromirror and a lens. For any very precise and small amplitudes of motion, micromachined electrostatic actuation may be used because it is the most compact in size, with low power consumption and has more straightforward sensing and control options.

  9. Micromachined electrostatic vertical actuator

    DOEpatents

    Lee, Abraham P.; Sommargren, Gary E.; McConaghy, Charles F.; Krulevitch, Peter A.

    1999-10-19

    A micromachined vertical actuator utilizing a levitational force, such as in electrostatic comb drives, provides vertical actuation that is relatively linear in actuation for control, and can be readily combined with parallel plate capacitive position sensing for position control. The micromachined electrostatic vertical actuator provides accurate movement in the sub-micron to micron ranges which is desirable in the phase modulation instrument, such as optical phase shifting. For example, compact, inexpensive, and position controllable micromirrors utilizing an electrostatic vertical actuator can replace the large, expensive, and difficult-to-maintain piezoelectric actuators. A thirty pound piezoelectric actuator with corner cube reflectors, as utilized in a phase shifting diffraction interferometer can be replaced with a micromirror and a lens. For any very precise and small amplitudes of motion` micromachined electrostatic actuation may be used because it is the most compact in size, with low power consumption and has more straightforward sensing and control options.

  10. The vertical distribution of Mars water vapor

    NASA Technical Reports Server (NTRS)

    Davies, D. W.

    1979-01-01

    Analysis of observations made from the Viking 1 Orbiter indicates that the water vapor over the Viking 1 landing site is uniformly mixed with the atmosphere and not concentrated near the surface. The analysis incorporates the effects of atmospheric scattering and explains why previous earth-based observations showed a strong diurnal variation in water content. It also explains the lack of an early morning fog and removes the necessity of daily exchange of large amounts of water between the surface and the atmosphere. A water vapor volume mixing ratio of 1.5 x 10 to the -4th is inferred for the Viking 1 site in late summer.

  11. The vertical distribution of Mars water vapor

    NASA Technical Reports Server (NTRS)

    Davies, D. W.

    1979-01-01

    Analysis of observations made from the Viking 1 Orbiter indicates that the water vapor over the Viking 1 landing site is uniformly mixed with the atmosphere and not concentrated near the surface. The analysis incorporates the effects of atmospheric scattering and explains why previous earth-based observations showed a strong diurnal variation in water content. It also explains the lack of an early morning fog and removes the necessity of daily exchange of large amounts of water between the surface and the atmosphere. A water vapor volume mixing ratio of 1.5 x 10 to the -4th is inferred for the Viking 1 site in late summer.

  12. NEWS: AAPT Summer Meeting

    NASA Astrophysics Data System (ADS)

    Mellema, Steve

    2000-11-01

    The 2000 Summer Meeting of the American Association of Physics Teachers (AAPT) was held from 28~July-2~August at the University of Guelph in Ontario, Canada. Despite somewhat rainy weather throughout the week, the annual gathering was an enjoyable one, filled with interesting talks on the state of physics education in North America. Using a new scheduling format for the summer meeting, all of the paid workshops and tutorials were held on Saturday and Sunday 29-30 July. The invited and contributed papers for the main AAPT meeting were then presented on Monday, Tuesday and Wednesday. As had been done in 1999 in San Antonio, a two-day tandem meeting dedicated to Physics Education Research (PER) was held on Wednesday and Thursday 2-3 August, immediately after the main AAPT meeting. Over the three days of the main meeting, 60 sessions were held under the sponsorship of various AAPT committees. These included sessions (numbers in parentheses) organized by the committees on Apparatus (1), Astronomy Education (3), Awards (2), Computers (5), Graduate Education (2), High Schools (1), History and Philosophy (1), Instructional Media (3), International Education (1), Laboratories (2), Pre-High School Education (2), Programs (4), Professional Concerns (6), Research in Physics Education (8), Science Education for the Public (2), Two-Year Colleges (5), Undergraduate Education (7) and Women in Physics (4). Figure 1. Guelph Church of Our Lady. The main meeting opened on Sunday evening with an invited lecture by Dr John J Simpson from the host institution, the University of Guelph, describing the Sudbury Neutrino Observatory. At the ceremonial session that began the activities on Monday morning, recognition was given to Clifford Swartz for his almost 30 years of service as Editor of the AAPT journal, The Physics Teacher. This was followed by an invited talk by Jim Nelson from Seminole County Public School in Florida, who received the Excellence in Pre-College Teaching Award. The

  13. The Summer of Hydrogen

    NASA Technical Reports Server (NTRS)

    Weber, Philip

    2008-01-01

    Ground crew veterans at Kennedy Space Center still talk about what they call "the summer of hydrogen"-the long, frustrating months in 1990 when the shuttle fleet was grounded by an elusive hydrogen leak that foiled our efforts to fill the orbiter's external fuel tank. Columbia (STS-35) was on Launch Pad A for a scheduled May 30 launch when we discovered the hydrogen leak during - tanking. The external fuel tank is loaded through the orbiter. Liquid hydrogen flows through a 17-inch umbilical between the orbiter and the tank. During fueling, we purge the aft fuselage with gaseous nitrogen to reduce the risk of fire, and we have a leak-detection system in the mobile launch platform, which samples (via tygon tubing) the atmosphere in and around the vehicle, drawing it down to a mass spectrometer that analyzes its composition. When we progressed to the stage of tanking where liquid hydrogen flows through the vehicle, the concentration of hydrogen approached four percent-the limit above which it would be dangerously flammable. We had a leak. We did everything we could think of to find it, and the contractor who supplied the flight hardware was there every day, working alongside us. We did tanking tests, which involved instrumenting the suspected leak sources, and cryo-loaded the external tank to try to isolate precisely where the leak originated. We switched out umbilicals; we replaced the seals between the umbilical and the orbiter. We inspected the seals microscopically and found no flaws. We replaced the recirculation pumps, and we found and replaced a damaged teflon seal in a main propulsion system detent cover, which holds the prevalve-the main valve supplying hydrogen to Space Shuttle Main Engine 3 -in the open position. The seal passed leak tests at ambient temperature but leaked when cryogenic temperatures were applied. We added new leak sensors-up to twenty at a time and tried to be methodical in our placements to narrow down the possible sources of the problem

  14. The year without a summer

    NASA Astrophysics Data System (ADS)

    Luterbacher, J.; Pfister, C.

    2015-04-01

    The 1815 eruption of Tambora caused an unusually cold summer in much of Europe in 1816. The extreme weather led to poor harvests and malnutrition, but also demonstrated the capability of humans to adapt and help others in worse conditions.

  15. Summer Alterations in Youth Fitness.

    ERIC Educational Resources Information Center

    Hastad, Douglas N.; Pangrazi, Robert P.

    1983-01-01

    A study investigated changes in children's physical fitness during summer vacation. Children's cardiorespiratory fitness decreased, as did their body weight, especially for boys. Fall curriculum offerings should be designed to accommodate detrained students. (PP)

  16. Goddard Summer Interns: Andy Ryan

    NASA Image and Video Library

    Andy Ryan is an intern staff assistant with the Lunar and Planetary Science Academy. This summer the LPSA traveled to the Channeled Scablands of eastern Washington to study and map the geology of t...

  17. Potentials Unlimited: A Summer Happening.

    ERIC Educational Resources Information Center

    Croskery, Beverly; Marten, Mary Elizabeth

    1980-01-01

    The article describes Potentials Unlimited, a summer camp program for gifted intermediate grade students in Cincinnati, Ohio. Aspects covered include priorities in selecting curricular activities and some of the camp activities themselves. (DLS)

  18. Goddard Summer Interns: Danielle Wood

    NASA Image and Video Library

    Profile of Goddard intern Danielle Wood. Danielle is interning at Goddard in the Innovative Partnerships Program and at NASA Headquarters in the Office of the Chief Technologist in the summer of 20...

  19. Summer of Innovation Kick Off

    NASA Image and Video Library

    2010-06-09

    Erin Gilbert, Director of Professional Development from the National Summer Learning Associations, motivates teachers and middle school students during the kick off of NASA's Summer of Innovation program at the Jet Propulsion Laboratory in Pasadena, Calif., Thursday, June 10, 2010. Through the program, NASA will engage thousands of middle school students and teachers in stimulating math and science-based education programs with the goal of increasing the number of future scientists, mathematicians, and engineers. Photo Credit: (NASA/Bill Ingalls)

  20. Vertical axis wind turbine

    SciTech Connect

    Cubbers, J.

    1993-07-13

    A vertical axis wind turbine is described comprising: a vertically extending axle supported for rotation about a vertical axis; a series of wind vanes arranged around said axle; support means supporting each of said wind vanes on said axle, each of said wind vanes comprising a substantially flat main panel section of flexible material draped vertically by said support means to extend in a circumferential direction; each of said wind vanes including at least one pocket comprised of a substantially flat overlayer panel of flexible material overlying the outside of said wind vane flexible material panel section and attached thereto along a vertical side by a seam and also attached thereto along the top and bottom, but unattached along the other side to form a normally closed pocket which is able to flare open when wind is blowing from the unattached side thereof and thereby catch said wind, said pocket collapsing when wind blows from the attached side of said overlayer by said overlayer panel again overlying said main panel section.

  1. Summer climate of Madagascar and monsoon pulsing of its vortex

    NASA Astrophysics Data System (ADS)

    Jury, Mark R.

    2016-02-01

    This study analyzes the climate of Madagascar (12°-26°S, 43°-50°E) and its relation to the Indian Ocean during austral summer (Dec-Mar). Moisture converges onto a standing easterly wave and floods are prevalent in late summer. All-island daytime land temperatures exceed 38 °C in October and are ~4 °C above sea temperatures during summer. Analysis of thermally induced diurnal convection and circulation revealed inflow during the afternoon recirculated from the southeastern mountains and the warm Mozambique Channel. Summer rainfall follows latent and sensible heat flux during the first half of the day, and gains a surplus by evening via thunderstorms over the western plains. At the inter-annual time-scale, 2.3 years oscillations in all-island rainfall appear linked with the stratospheric quasi-biennial oscillation and corresponding 80 Dobson Unit ozone fluctuations during flood events. Wet spells at frequencies from 11-27 days derive from locally-formed tropical cyclones and NW-cloud bands. Flood case studies exhibit moisture recycling in the confluence zone between the sub-tropical anticyclone and the lee-side vortex. Hovmoller analysis of daily rainfall reinforces the concept of local generation and pulsing by cross-equatorial (Indian winter) monsoon flow rather than zonal atmospheric waves. Since the surface water budget is critical to agriculture in Madagascar, this study represents a further step to understand its meso-scale summer climate.

  2. Summer Final Report

    NASA Technical Reports Server (NTRS)

    Makidi, Nitou

    2012-01-01

    The summer of 2012 has been filled with many memorable events and activities. As an intern, I had responsibilities that had to be fulfilled. My tour of duty was completed as an administrative student trainee in the Information Technology and Communications Services Business Office (IT-A). In accordance with the Business Objectives and Agreement of the Business Office and my performance plan, I was to provide business office support, improve business, project management, and technical work processes. With this being stated, I supported a project called "The Big Move Project" (TBMP), which will take course over the next several years. The Big Move Project is the planning of the Information Technology (IT) Directorate's relocation to various buildings in the course of upcoming years, when designs and the building of Central Campus have been completed. Working directly with my supervisor and the project manager, I was responsible for gathering both administrative and operational area requirements for the Information Technology (IT) Directorate, along with its outsourced support and contractors, such as IMCS, NICS, and ACES. My first action was to create rubrics that will serve as a guideline for the information that should be given by each branch of IT. After receiving that information via a few KAITS actions, I was able to start the consolidation process, and begin working on a presentation. A SharePoint was created shortly after for others to view the progression of the project, which I managed. During the consolidation ofthis information, I would occasionally present to the IT Deputy Director and IT Chiefs. The draft of this presentation was shown to employees of Center Operations (T A) and stakeholders-IT Chief Officers and contractor managers-in the relocation of IT to make them aware of what requirements must be met that will enable IT to be accommodated appropriately in the design of Central Campus Phase 11-the time in which IT and its contractors are scheduled

  3. Physical mechanisms of the seasonal, subseasonal, and high-frequency variability in the seasonal cycle of summer precipitation in Korea

    NASA Astrophysics Data System (ADS)

    Kim, Kwang-Yul; Roh, Joon-Woo; Lee, Dong-Kyou; Jhun, Jong-Ghap

    2010-07-01

    Three distinct physical mechanisms in the seasonal cycle of the 120 day (19 May to 15 September) summer precipitation in Korea (126°E-130°E, 33°N-38°N) were identified using the 1979-2008 observed precipitation records at 61 Korea Meteorological Administration stations. Detailed space-time structures of the physical mechanisms of precipitation variability were derived using the daily National Center for Environmental Prediction/National Center for Atmospheric Research reanalysis data over Asia (80°E-180°E, 0°-60°N). The seasonal cycle of summertime precipitation in Korea exhibits three principal temporal scales (seasonal, subseasonal, and high-frequency components) of variability, each with distinct physical mechanisms. The seasonal component represents the variability associated with the evolution of the Asian summer monsoon, specifically the East Asia summer monsoon, governed primarily by large-scale circulation as a result of changes in sea level pressure contrasts between the Asian continent and the surrounding oceans. The arrival and the duration of a monsoon front primarily shape the seasonal evolution of precipitation in Korea. The bimodal peaks are due to the low-level circulation change as a result of redistribution of temperature and, subsequently, of sea level pressure during summer. The subseasonal component has characteristic time scales of 10-30 days and is associated with eastward-moving upper-level disturbances at ˜40°N. The upper-level disturbances affect the meridional circulations, resulting in low-level convergence/divergence not only underneath but also to the south and to the north of the disturbance. From mid-July to mid-August, the subseasonal component is more clearly observable, and the period of oscillations is generally shorter, than during early or late summer. The high-frequency component with time scales of less than 10 days is associated with midlatitude baroclinic Rossby waves; synoptic-scale variations of upper

  4. Indian Summer Monsoon influence on the Arabian Peninsula Summer Climate

    NASA Astrophysics Data System (ADS)

    Attada, Raju; Prasad Dasari, Hari; Omar, Knio; Hoteit, Ibrahim

    2017-04-01

    The Indian Summer Monsoon (ISM) is as an integral component of the atmospheric global circulation. During summer, the mid-latitude zone of baroclinic waves in the Middle East region are pushed northward under the influence of ISM. We investigate the impact of ISM on the atmospheric circulation over the Arabian Peninsula on interannual time scale. We analyze various atmospheric variables derived from ECMWF reanalysis. We apply a composite analysis to study the circulation variability over the Middle East during extreme monsoon years. The extreme (strong and weak) monsoon years are identified based on All India Precipitation Index during 1979-2015. Our analysis reveals that ISM is a fundamental driver of the summer circulation over the Middle East. More specifically, during extreme monsoons: (i) the lower tropospheric winds are enhanced and dominated by persistent northerlies along with intensified subsidence due to adiabatic warming, (ii) A prominent baroclinic structure in circulation anomalies are observed, (iii) a meridional shift of the upper tropospheric jet stream (subtropical jet) is noticeable during weak monsoon years; this shift favors a strong Rossby wave response and has a consequent impact on summer circulations over the Middle East, (iv) the upper tropospheric wind anomalies show a well organized train of Rossby waves during strong monsoon years, and (v) Intensification of thermal signal during strong monsoon over West Asia has been noticed. We will present these findings and further discuss the monsoon dynamics controlling the summer Arabian Peninsula circulation.

  5. [Duane vertical surgical treatment].

    PubMed

    Merino, M L; Gómez de Liaño, P; Merino, P; Franco, G

    2014-04-01

    We report 3 cases with a vertical incomitance in upgaze, narrowing of palpebral fissure, and pseudo-overaction of both inferior oblique muscles. Surgery consisted of an elevation of both lateral rectus muscles with an asymmetrical weakening. A satisfactory result was achieved in 2 cases, whereas a Lambda syndrome appeared in the other case. The surgical technique of upper-insertion with a recession of both lateral rectus muscles improved vertical incomitance in 2 of the 3 patients; however, a residual deviation remains in the majority of cases. Copyright © 2011 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.

  6. A vertical cephalometric analysis.

    PubMed

    Alió Sanz, Juan J; Iglesias Conde, Carmen

    2007-01-01

    Correctly assessing open-bite malocclusions has remained problematic because clinicians have not had entirely reliable methods of determining the exact amount of skeletal and dental contributions to the problem. A new cephalometric technique, the vertical cephalometric analysis, offers orthodontists a system that precisely identifies the percentage of skeletal and dentoalveolar components that open-bite patients have. The vertical cephalometric analysis offers a discriminating diagnostic method for evaluating, diagnosing, and treatment planning for patients with open bite. This technique will allow clinicians to classify patients with accuracy, as well as to establish prognoses and select therapies.

  7. Warm summers during Younger Dryas cold reversal over Eurasia

    NASA Astrophysics Data System (ADS)

    Schenk, Frederik; Muschitiello, Francesco; Heikkilä, Miaja; Väliranta, Minna; Tarasov, Lev; Brandefelt, Jenny; Johansson, Arne; Näslund, Jens-Ove; Wohlfarth, Barbara

    2016-04-01

    The Younger Dryas cold reversal (GS-1) sticks out as a major stadial interrupting the mid to late deglaciation with a sharp temperature drop of several degrees around the North Atlantic with global teleconnections. The abrupt return to a very cold glacial-like ocean state introduces a strong temperature anomaly to the climate system contrasting the high solar radiation received by northern summers. Here we show that, in contrast to earlier coarse resolution climate simulations of the Younger Dryas, these competing factors result in rather warm summer conditions over Eurasia comparable to the preceding warm period of the late Allerød (GI-1a). Despite up to 10 K colder sea-surface-temperatures in summer, our high resolution simulation with the Community Earth System Model 1 (CESM1.0.5) suggests that the presence of large ice sheets over Scandinavia, Spitsbergen and the Kara Sea significantly modifies atmospheric flow in summer preventing cold westerly winds from the Atlantic to impact the continent. Instead, fluid dynamics around ice sheets deflect winds to the north or south along the coasts supported by divergent flow from ice domes, stratification and increased tendency to high pressure and atmospheric blocking. Consistent with our model simulation, we show that temperature reconstructions derived from an extended compilation of multi-proxy lake records (chironomids, aquatic pollen, macrofossils) suggest warm July conditions of 13-17° C for continental Europe with exception of coastal and high elevation sites. The analysis of simulated growing degree days, season length and first results from paleo lake modelling driven by climate model output suggests that severe winter to spring conditions significantly delay and shorten the vegetation season but do not produce cold summers as previously simulated.

  8. Aiding Vertical Guidance Understanding

    NASA Technical Reports Server (NTRS)

    Feary, Michael; McCrobie, Daniel; Alkin, Martin; Sherry, Lance; Polson, Peter; Palmer, Everett; McQuinn, Noreen

    1998-01-01

    A two-part study was conducted to evaluate modern flight deck automation and interfaces. In the first part, a survey was performed to validate the existence of automation surprises with current pilots. Results indicated that pilots were often surprised by the behavior of the automation. There were several surprises that were reported more frequently than others. An experimental study was then performed to evaluate (1) the reduction of automation surprises through training specifically for the vertical guidance logic, and (2) a new display that describes the flight guidance in terms of aircraft behaviors instead of control modes. The study was performed in a simulator that was used to run a complete flight with actual airline pilots. Three groups were used to evaluate the guidance display and training. In the training, condition, participants went through a training program for vertical guidance before flying the simulation. In the display condition, participants ran through the same training program and then flew the experimental scenario with the new Guidance-Flight Mode Annunciator (G-FMA). Results showed improved pilot performance when given training specifically for the vertical guidance logic and greater improvements when given the training and the new G-FMA. Using actual behavior of the avionics to design pilot training and FMA is feasible, and when the automated vertical guidance mode of the Flight Management System is engaged, the display of the guidance mode and targets yields improved pilot performance.

  9. Vertical shaft windmill

    NASA Technical Reports Server (NTRS)

    Grana, D. C.; Inge, S. V., Jr. (Inventor)

    1983-01-01

    A vertical shaft has several equally spaced blades mounted. Each blade consists of an inboard section and an outboard section skew hinged to the inboard section. The inboard sections automatically adjust their positions with respect to the fixed inboard sections with changes in velocity of the wind. This windmill design automatically governs the maximum rotational speed of shaft.

  10. Changes in the association between summer temperature and mortality in Seoul, South Korea

    NASA Astrophysics Data System (ADS)

    Ha, Jongsik; Kim, Ho

    2013-07-01

    The health impact of climate change depends on various conditions at any given time and place, as well as on the person. Temporal variations in the relationship between high temperature and mortality need to be explored in depth to explain how changes in the level of exposure and public health interventions modify the temperature-mortality relationship. We examined changes in the relationship between human mortality and temperature in Seoul, which has the highest population in South Korea, considering the change in population structure from 1993-2009. Poisson regression models were used to estimate short-term temperature-related mortality impacts. Temperature-related risks were divided into two "time periods" of approximately equal length (1993 and 1995-2000, and 2001-2009), and were also examined according to early summer and late summer. Temperature-related mortality in summer over the past 17 years has declined. These decreasing patterns were stronger for cardiovascular disease-related mortality than for all non-accidental deaths. The novel finding is that declines in temperature-related mortality were particularly noteworthy in late summer. Our results indicate that temperature-related mortality is decreasing in Seoul, particularly during late summer and, to a lesser extent, during early summer. This information would be useful for detailed public health preparedness for hot weather.

  11. OH vertical column abundance - Tropical measurements

    NASA Astrophysics Data System (ADS)

    Burnett, Clyde R.; Minschwaner, Kenneth R.; Burnett, Elizabeth B.

    1990-09-01

    Measurements of the vertical column abundance of atmospheric hydroxyl (OH) have been made during the period 1987-1989 at the National Weather Service (NWS) station at Moen, Truk, Federated States of Micronesia (7 deg N, 152 deg E). A total of 384 independent data sets was obtained. Tropical OH abundance levels average about 22 percent above corresponding mid-latitude values, with OH levels during late winter and early spring up to 50 percent above those observed at 40 deg N. Stratospheric wind and temperature data obtained from the daily NWS radiosonde data are examined for correlations with the OH results.

  12. OH vertical column abundance - Tropical measurements

    NASA Technical Reports Server (NTRS)

    Burnett, Clyde R.; Minschwaner, Kenneth R.; Burnett, Elizabeth B.

    1990-01-01

    Measurements of the vertical column abundance of atmospheric hydroxyl (OH) have been made during the period 1987-1989 at the National Weather Service (NWS) station at Moen, Truk, Federated States of Micronesia (7 deg N, 152 deg E). A total of 384 independent data sets was obtained. Tropical OH abundance levels average about 22 percent above corresponding mid-latitude values, with OH levels during late winter and early spring up to 50 percent above those observed at 40 deg N. Stratospheric wind and temperature data obtained from the daily NWS radiosonde data are examined for correlations with the OH results.

  13. Diel feeding behavior and ingestion rate in the copepod Calanus finmarchicus in the southern Gulf of Maine during late spring

    NASA Astrophysics Data System (ADS)

    Durbin, Edward G.; Campbell, Robert G.; Gilman, Sharon L.; Durbin, Ann G.

    In situ feeding was measured on late stage Calanus finmarchicus in the southern Gulf of Maine during late spring 1988 and 1989. The region is a spring feeding ground for the planktivorous right whale, Eubalaena glacialis. Measurements in 1988 were made during the declining spring bloom, when phytoplankton showed considerable spatial variability. 1989 observations were made after summer stratification had become established, when phytoplankton biomass was low and dominated by the <7 μm size fraction. In situ ingestion rates of C. finmarchicus reflected these differences in food, and ranged from 30.2% body C day -1 at a spring bloom station to 0.6% body C day -1 after stratification. These values compare with a maximum ingestion rate of 44.3% body C day -1 measured in a shipboard grazing experiment using cultured algae as food, and indicate that C. finmarchicus became food limited in the southern Gulf of Maine after stratification. Calanus finmarchicus diet feeding behavior and diet vertical migration patterns changed during the seasonal progression from spring bloom to summer stratification. Diet feeding rhythms and vertical migration were absent during the bloom, but developed as the bloom declined. During the post-bloom stratified conditions, diet feeding rhythms continued but vertical migration ceased. Most of the C. finmarchicus population remained near the surface, while a small population of nonmigratory individuals resided at depth and appeared to be feeding upon sedimented spring bloom diatoms. At the spring bloom station C. finmarchicus ingested only a small proportion of the phytoplankton standing stock in the > 7 μm size fraction (2.9% day -1), reflecting the high biomass of phytoplankton and the stage composition of the C. finmarchicus population, dominated by early copepodite stages with low biomass. In contrast, at the post-bloom stations in 1989, the dense surface aggregations of C. finmarchicus populations were dominated by late copepodite stages

  14. Summer Fun in the Sun

    NASA Astrophysics Data System (ADS)

    Alexander, D.; Noldon, D.

    2002-05-01

    We report here on the development of a program to incorporate a math/science component, emphasizing space science and solar physics, into an existing set of summer activities sponsored by the National Youth Sports Program (NYSP). NYSP provides summer sports and classroom training components to youth whose families fall within federal poverty guidelines. Recently, a partnership between Lockheed Martin Solar and Astrophysics Lab. and Chabot Community College received NASA IDEAS funding to develop a summer curriculum in math and science to augment the already successful program. This provides an opportunity to significantly enhance the experience of the participating students by giving them access to the latest in space data and direct interaction with space scientists. This paper discusses our goals, our approach and the current status of our curricular materials. We would like to acknowledge funding by the National Youth Sports Program and NASA IDEAS.

  15. Hottest summers the new normal

    NASA Astrophysics Data System (ADS)

    Camargo, Suzana J.; Seth, Anji

    2016-08-01

    With the rise in temperature due to anthropogenic climate change, the occurrence of hot summers, temperature extremes and heat waves is increasing globally. Projections for the coming decades to century indicate increases in the occurrence, magnitude and duration of these events. In a recent paper, Mueller et al (2016 Environ. Res. Lett. 11 044011) showed that half of summers are expected to be ‘hot’ (warmer than the warmest on record) across much of the world in one or two decades. While these results are consistent with earlier work, what is new here includes (i) an earlier timing of emergence of the hot summer signal and (ii) additional confidence due to the rigorous statistical examination of the observations and the analyses of the latest improved suite of model experiments. The potential impacts of these projections on society are extremely serious.

  16. Summer Monsoon, Kalahari Desert, Africa

    NASA Image and Video Library

    1992-11-01

    STS052-152-047 (22 Oct- 1 Nov 1992) --- The Kalahari Desert had not seen any significant rainfall for months before the launch of STS-52. Here, Shuttle astronauts have captured the onset of the (Southern Hemisphere) summer monsoon over the Kalahari Desert, as illustrated by the large thunderstorm towers poking up through the sun's terminator. The summer monsoon, with its associated thunderstorms, generally lasts from November through March. Scientist observers of this area report that the summer monsoon contributes most of the annual rainfall to this environmentally sensitive area. Shuttle nadir position: 28.0 degrees south, 25.1 degrees east. The center of the scene is 22.0 degrees south, 25.0 degrees east, 16:20:04 GMT.

  17. Summer ice and carbon dioxide

    SciTech Connect

    Kukla, G.; Gavin, J.

    1981-10-30

    The extent of Antarctic pack ice in the summer, as charted from satellite imagery, decreased by 2.5 million square kilometers between 1973 and 1980. The U.S. Navy and Russian atlases and whaling and reseach ship reports from the 1930's indicate that summer ice conditions earlier in this century were heavier than the current average. Surface air temperatures along the seasonally shifting belt of melting snow between 55/sup o/ and 80/sup o/N during spring and summer were higher in 1974 to 1978 than in 1934 to 1938. The observed departures in the two hemispheres qualitatively agree with the predicted impact of an increase in atmospheric carbon dioxide. However, since it is not known to what extent the changes in snow and ice cover and in temperature can be explained by the natural variability of the climate system or by other processes unrelated to carbon dioxide, a cause-and-effect relation cannot yet be established.

  18. Summer Ice and Carbon Dioxide

    NASA Astrophysics Data System (ADS)

    Kukla, G.; Gavin, J.

    1981-10-01

    The extent of Antarctic pack ice in the summer, as charted from satellite imagery, decreased by 2.5 million square kilometers between 1973 and 1980. The U.S. Navy and Russian atlases and whaling and research ship reports from the 1930's indicate that summer ice conditions earlier in this century were heavier than the current average. Surface air temperatures along the seasonally shifting belt of melting snow between 55 degrees and 80 degrees N during spring and summer were higher in 1974 to 1978 than in 1934 to 1938. The observed departures in the two hemispheres qualitatively agree with the predicted impact of an increase in atmospheric carbon dioxide. However, since it is not known to what extent the changes in snow and ice cover and in temperature can be explained by the natural variability of the climate system or by other processes unrelated to carbon dioxide, a cause-and-effect relation cannot yet be established.

  19. Turbulent Mixing and Vertical Heat Transfer in the Surface Mixed Layer of the Arctic Ocean: Implication of a Cross-Pycnocline High-Temperature Anomaly

    NASA Astrophysics Data System (ADS)

    Kawaguchi, Yusuke; Takeda, Hiroki

    2017-04-01

    This study focuses on the mixing processes in the vicinity of surface mixed layer (SML) of the Arctic Ocean. Turbulence activity and vertical heat transfer are quantitatively characterized in the Northwind Abyssal Plain, based on the RV Mirai Arctic cruise, during the transition from late summer to early winter 2014. During the cruise, noticeable storm events were observed, which came over the ship's location and contributed to the deepening of the SML. According to the ship-based microstructure observation, within the SML, the strong wind events produced enhanced dissipation rates of turbulent kinetic energy in the order of magnitude of ɛ = 10-6-10-4W kg-1. On thermal variance dissipation rate, χ increases toward the base of SML, reaching O(10-7) K2 s-1, resulting in vertical heat flux of O(10) W m-2. During the occasional energetic mixing events, the near-surface warm water was transferred downward and penetrated through the SML base, creating a cross-pycnocline high-temperature anomaly (CPHTA) at approximately 20-30 m depth. Near CPHTA, the vertical heat flux was anomalously magnified to O(10-100) W m-2. Following the fixed-point observation, in the regions of marginal and thick ice zones, the SML heat content was monitored using an autonomous drifting buoy, UpTempO. During most of the ice-covered period, the ocean-to-ice turbulent heat flux was dominant, rather than the diapycnal heat transfer across the SML bottom interface.

  20. Think Summer: Early Planning, Teacher Support Boost Summer Learning Programs

    ERIC Educational Resources Information Center

    Browne, Daniel

    2013-01-01

    A fundamental problem that continues to plague educators is the achievement gap between low-income and higher-income students. In the ongoing search for solutions, one of the more promising approaches is expanding opportunities for learning, particularly in the summer. This article describes a project funded by The Wallace Foundation that offers…

  1. Think Summer: Early Planning, Teacher Support Boost Summer Learning Programs

    ERIC Educational Resources Information Center

    Browne, Daniel

    2013-01-01

    A fundamental problem that continues to plague educators is the achievement gap between low-income and higher-income students. In the ongoing search for solutions, one of the more promising approaches is expanding opportunities for learning, particularly in the summer. This article describes a project funded by The Wallace Foundation that offers…

  2. 1998 Complex Systems Summer School

    SciTech Connect

    1998-12-15

    For the past eleven years a group of institutes, centers, and universities throughout the country have sponsored a summer school in Santa Fe, New Mexico as part of an interdisciplinary effort to promote the understanding of complex systems. The goal of these summer schools is to provide graduate students, postdoctoral fellows and active research scientists with an introduction to the study of complex behavior in mathematical, physical, and living systems. The Center for Nonlinear Studies supported the eleventh in this series of highly successful schools in Santa Fe in June, 1998.

  3. Vertical Structure and Vertical Evolution of Halogen Activation Events Observed by Autonomous Buoys

    NASA Astrophysics Data System (ADS)

    Simpson, W. R.; Peterson, P.; Burd, J.

    2015-12-01

    Heterogeneous reactions on saline surfaces release reactive halogen species in the Arctic during late winter / spring (Feb--May). These reactive halogens drastically alter the photooxidative environment, removing ozone and oxidizing mercury and hydrocarbons. Both the snowpack and suspended particles / blowing snow possess surfaces that can sustain this chemistry, leading to variations in reactive halogen vertical profiles and temporal evolution of those profiles. This chemistry also occurs in a typically stable (inverted) atmospheric structure that hinders vertical mixing, limiting the vertical extent of snowpack influence. In this presentation, Multiple-AXis Differential Optical Absorption Spectroscopy (MAXDOAS) of bromine monoxide (BrO) along with optimal estimation inversions are used to measure the vertical structure of BrO. The effective mixing height of the BrO layer varies with atmospheric stability, and an event is shown where a shallow but highly concentrated layer of surface BrO encounters sea-ice-lead-induced convection that vertically mixes the BrO higher, initially diluting the surface concentration. Over time, the surface concentration recovers and the now thicker layer grows to a higher column density of BrO. Understanding of the relationship between BrO event intensity and meteorological situations can help to understand BrO chemistry and remote sensing and assist in prediction of how reactive halogens may respond to a changing Arctic climate.

  4. Vertical orbital dystopia.

    PubMed

    Tan, S T; Ashworth, G; Czypionka, S; Poole, M D; Briggs, M

    1996-06-01

    Many pathologic processes may lead to vertical orbital dystopia. We reviewed 47 consecutive cases seen over a 13-year period. Twenty-nine patients underwent eye leveling procedures to improve cosmesis, 2 of these by camouflage procedures and 27 by orbital translocation. Ten patients had 16 secondary operations. There was one death, serious complications occurred in 3 patients, and nuisance complications occurred in 20 others. Seven patients developed diplopia postoperatively, and in 6 patients it was troublesome. In these, it resolved fully in 2 patients, improved to be of no consequence in 2, and in the remaining 2 troublesome symptoms persisted requiring inferior oblique muscle recession in 1. Binocular vision was never restored when not present preoperatively, and in 3 patients temporary loss occurred. There was an overall modest but significant improvement in appearance after surgery. It is concluded that vertical orbital translocation is rewarding and worthwhile.

  5. PSP toxin levels and plankton community composition and abundance in size-fractionated vertical profiles during spring/summer blooms of the toxic dinoflagellate Alexandrium fundyense in the Gulf of Maine and on Georges Bank, 2007, 2008, and 2010: 2. Plankton community composition and abundance

    PubMed Central

    Petitpas, Christian M.; Turner, Jefferson T.; Deeds, Jonathan R.; Keafer, Bruce A.; McGillicuddy, Dennis J.; Milligan, Peter J.; Shue, Vangie; White, Kevin D.; Anderson, Donald M.

    2015-01-01

    As part of the Gulf of Maine Toxicity (GOMTOX1) project, we determined Alexandrium fundyense abundance, paralytic shellfish poisoning (PSP) toxin levels in various plankton size fractions, and the community composition of potential grazers of A. fundyense in plankton size fractions during blooms of this toxic dinoflagellate in the coastal Gulf of Maine and on Georges Bank in spring and summer of 2007, 2008, and 2010. PSP toxins and A. fundyense cells were found throughout the sampled water column (down to 50 m) in the 20–64 μm size fractions. While PSP toxins were widespread throughout all size classes of the zooplankton grazing community, the majority of the toxin was measured in the 20–64 μm size fraction. A. fundyense cellular toxin content estimated from field samples was significantly higher in the coastal Gulf of Maine than on Georges Bank. Most samples containing PSP toxins in the present study had diverse assemblages of grazers. However, some samples clearly suggested PSP toxin accumulation in several different grazer taxa including tintinnids, heterotrophic dinoflagellates of the genus Protoperidinium, barnacle nauplii, the harpacticoid copepod Microsetella norvegica, the calanoid copepods Calanus finmarchicus and Pseudocalanus spp., the marine cladoceran Evadne nordmanni, and hydroids of the genus Clytia. Thus, a diverse assemblage of zooplankton grazers accumulated PSP toxins through food-web interactions. This raises the question of whether PSP toxins pose a potential human health risk not only from nearshore bivalve shellfish, but also potentially from fish and other upper-level consumers in zooplankton-based pelagic food webs. PMID:26236112

  6. PSP toxin levels and plankton community composition and abundance in size-fractionated vertical profiles during spring/summer blooms of the toxic dinoflagellate Alexandrium fundyense in the Gulf of Maine and on Georges Bank, 2007, 2008, and 2010: 2. Plankton community composition and abundance.

    PubMed

    Petitpas, Christian M; Turner, Jefferson T; Deeds, Jonathan R; Keafer, Bruce A; McGillicuddy, Dennis J; Milligan, Peter J; Shue, Vangie; White, Kevin D; Anderson, Donald M

    2014-05-01

    As part of the Gulf of Maine Toxicity (GOMTOX) project, we determined Alexandrium fundyense abundance, paralytic shellfish poisoning (PSP) toxin levels in various plankton size fractions, and the community composition of potential grazers of A. fundyense in plankton size fractions during blooms of this toxic dinoflagellate in the coastal Gulf of Maine and on Georges Bank in spring and summer of 2007, 2008, and 2010. PSP toxins and A. fundyense cells were found throughout the sampled water column (down to 50 m) in the 20-64 μm size fractions. While PSP toxins were widespread throughout all size classes of the zooplankton grazing community, the majority of the toxin was measured in the 20-64 μm size fraction. A. fundyense cellular toxin content estimated from field samples was significantly higher in the coastal Gulf of Maine than on Georges Bank. Most samples containing PSP toxins in the present study had diverse assemblages of grazers. However, some samples clearly suggested PSP toxin accumulation in several different grazer taxa including tintinnids, heterotrophic dinoflagellates of the genus Protoperidinium, barnacle nauplii, the harpacticoid copepod Microsetella norvegica, the calanoid copepods Calanus finmarchicus and Pseudocalanus spp., the marine cladoceran Evadne nordmanni, and hydroids of the genus Clytia. Thus, a diverse assemblage of zooplankton grazers accumulated PSP toxins through food-web interactions. This raises the question of whether PSP toxins pose a potential human health risk not only from nearshore bivalve shellfish, but also potentially from fish and other upper-level consumers in zooplankton-based pelagic food webs.

  7. 'Endurance' All Around Vertical)

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This 360-degree view of the terrain surrounding NASA's Mars Exploration Rover Opportunity was taken on the rover's 171st sol on Mars (July 17, 2004). It was assembled from images taken by the rover's navigation camera at a position referred to as 'site 33.' Opportunity had driven 11 meters (36 feet) into 'Endurance Crater.' The view is a vertical projection with geometrical seam correction.

  8. Hilly Surroundings (vertical)

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This 360-degree view of the terrain surrounding NASA's Mars Exploration Rover Spirit was taken on the rover's 189th sol on Mars (July 15, 2004). It was assembled from images taken by the rover's navigation camera at a position referred to as Site 72, which is at the base of the 'West Spur' portion of the 'Columbia Hills.'' The view is presented in a vertical projection with geometrical seam correction.

  9. Protective Vertical Shelters.

    DTIC Science & Technology

    1983-06-29

    on Generic MX Structures" by John Betz. 5. (AFCMD/82-013) "Finite Element Dynamic Analysis of th, DCT-2 Models" by Barry Bingham . 61 (AFCMD/82-017) "MX...facility to define the HEST structure for the GOVS tests. A SAMSON dynamic finite-element computer code provided pretest predictions of strdsses and...as piecewise linear, elastic- plastic materials. TEST DESCRIPTION Shel ter Models The generic MX vertical shelter is basically a large, reinforced

  10. Vertical bloch line memory

    NASA Technical Reports Server (NTRS)

    Katti, Romney R. (Inventor); Stadler, Henry L. (Inventor); Wu, Jiin-chuan (Inventor)

    1995-01-01

    A new read gate design for the vertical Bloch line (VBL) memory is disclosed which offers larger operating margin than the existing read gate designs. In the existing read gate designs, a current is applied to all the stripes. The stripes that contain a VBL pair are chopped, while the stripes that do not contain a VBL pair are not chopped. The information is then detected by inspecting the presence or absence of the bubble. The margin of the chopping current amplitude is very small, and sometimes non-existent. A new method of reading Vertical Bloch Line memory is also disclosed. Instead of using the wall chirality to separate the two binary states, the spatial deflection of the stripe head is used. Also disclosed herein is a compact memory which uses vertical Bloch line (VBL) memory technology for providing data storage. A three-dimensional arrangement in the form of stacks of VBL memory layers is used to achieve high volumetric storage density. High data transfer rate is achieved by operating all the layers in parallel. Using Hall effect sensing, and optical sensing via the Faraday effect to access the data from within the three-dimensional packages, an even higher data transfer rate can be achieved due to parallel operation within each layer.

  11. Summer Learning and School Achievement.

    ERIC Educational Resources Information Center

    Coleman, James

    1982-01-01

    Reviews research by Heyns and by Hayes and Grether that compared what children learned during the school year to what they learned during the summer vacation. Holds that, despite problems with these studies, they further confirm the positive effects of schooling. (GC)

  12. Summer 1993 Transient Student Report.

    ERIC Educational Resources Information Center

    Kent State Univ., Warren, OH. Office of Institutional Research.

    A study was conducted by the Trumbull Campus (TC) of Kent State University, in Ohio, to determine the motivations, objectives, and level of satisfaction of transient students, or students pursuing a degree at another institution but enrolled in courses at TC. Surveys were mailed to 50 transient students enrolled in summer 1993, with completed…

  13. Students Participate in Summer Program.

    ERIC Educational Resources Information Center

    Oliver, Jimmie Nell

    1997-01-01

    The Agricultural Research Service provides "hands-on" work experience in a research laboratory to college students interested in agriculture, science, math, and other related fields. Three Native American college students describe how participating in this summer intern program has helped them pursue their educational goals. (TD)

  14. Learners in Action, Summer 2005

    ERIC Educational Resources Information Center

    Movement for Canadian Literacy, 2005

    2005-01-01

    This Summer 2005 issue of "Learners in Action" contains the following articles: (1) Bridging Barriers to Learning (Glenn Kissman); (2) Education Really Is a Family Affair; (3) Sabrina's Story; (4) SARAW Helps Students Find Their Voice; (5) Literacy Changes Lives; and (6) Seeing STARs in Alberta.

  15. Summer Reading Goes High Tech

    ERIC Educational Resources Information Center

    Fink, Jennifer L. W.

    2012-01-01

    Not long ago, "summer reading" meant settling under a shady tree with a hefty book. Shady trees are still around, but books with pages can seem as out-of-date as vinyl records to many kids, especially older ones. Today, they scroll through content online, swipe pages on tablets, and manage a near-constant stream of media. Teachers can take…

  16. Welcome to LANL Summer 2012

    SciTech Connect

    Bishop, Alan

    2012-06-19

    Alan Bishop, Principal Associate Director for Science, Technology & Engineering, delivers a Laboratory overview and welcome to the summer student population. Topics include LANL mission, opportunities, organization, and workforce, and the briefing concludes with a more in-depth look of the student programs.

  17. Make Summer Your Growing Season.

    ERIC Educational Resources Information Center

    Simons, Harriet

    1982-01-01

    Describes the opportunities available in summer workshops and graduate programs for music teachers. The impact of the workshops and programs on improving teacher effectiveness is evaluated. Criteria are included for evaluating program offerings for their usefulness to teachers. The author offers suggestions to workshop planners to improve the…

  18. Alumni Colleges Sprout in Summer

    ERIC Educational Resources Information Center

    Morrison, Joan

    1978-01-01

    The alumni college, one of the fastest-spreading of the new developments on the summer campus, helps colleges get added income and the alumnus gets a stimulating vacation in a familiar setting. Describes some alumni college programs and a number of other promising programs introduced on different campuses in recent years. (Author/RK)

  19. Arctic Sea Ice, Summer 2014

    NASA Image and Video Library

    An animation of daily Arctic sea ice extent in summer 2014, from March 21, 2014 to Sept. 17, 2014 – when the ice appeared to reach it’s minimum extent for the year. It’s the sixth lowest minimum se...

  20. Formulating Policy for Summer Schools.

    ERIC Educational Resources Information Center

    Marriot, Helen

    1991-01-01

    Explores issues relating to the formulation of policy for summer programs for language learning, describing one university's experience with student demand, student motivation and progress, course timing and structure, academic staffing, administrative organization, student and staff evaluation, and funding. (three references) (CB)

  1. The Encouragement of Summer Enrollment.

    ERIC Educational Resources Information Center

    Montgomery, David C.

    1982-01-01

    Florida's unsuccessful statewide, 20-year effort to encourage summer enrollment began with conversion from a semester to trimester calendar, then to a quarter system, and included such incentives as tuition reduction, dormitory rate reduction, adoption of full course schedules, and mandatory enrollment. (MSE)

  2. Summer Coursework and Completing College

    ERIC Educational Resources Information Center

    Attewell, Paul; Jang, Sou Hyun

    2013-01-01

    The summer school sessions that colleges offer their undergraduates are sometimes considered supplementary activities and are rarely perceived as central to a college's mission or effectiveness. However, analyses of college transcript data that tracked a nationally-representative sample of undergraduates for several years and through multiple…

  3. Alumni Colleges Sprout in Summer

    ERIC Educational Resources Information Center

    Morrison, Joan

    1978-01-01

    The alumni college, one of the fastest-spreading of the new developments on the summer campus, helps colleges get added income and the alumnus gets a stimulating vacation in a familiar setting. Describes some alumni college programs and a number of other promising programs introduced on different campuses in recent years. (Author/RK)

  4. Investigation of summer monsoon rainfall variability in Pakistan

    NASA Astrophysics Data System (ADS)

    Hussain, Mian Sabir; Lee, Seungho

    2016-08-01

    This study analyzes the inter-annual and intra-seasonal rainfall variability in Pakistan using daily rainfall data during the summer monsoon season (June to September) recorded from 1980 to 2014. The variability in inter-annual monsoon rainfall ranges from 20 % in northeastern regions to 65 % in southwestern regions of Pakistan. The analysis reveals that the transition of the negative and positive anomalies was not uniform in the investigated dataset. In order to acquire broad observations of the intra-seasonal variability, an objective criterion, the pre-active period, active period and post-active periods of the summer monsoon rainfall have demarcated. The analysis also reveals that the rainfall in June has no significant contribution to the increase in intra-seasonal rainfall in Pakistan. The rainfall has, however, been enhanced in the summer monsoon in August. The rainfall of September demonstrates a sharp decrease, resulting in a high variability in the summer monsoon season. A detailed examination of the intra-seasonal rainfall also reveals frequent amplitude from late July to early August. The daily normal rainfall fluctuates significantly with its maximum in the Murree hills and its minimum in the northwestern Baluchistan.

  5. Synoptic drivers of 400 years of summer temperature and precipitation variability on Mt. Olympus, Greece

    NASA Astrophysics Data System (ADS)

    Klesse, Stefan; Ziehmer, Malin; Rousakis, Georgios; Trouet, Valerie; Frank, David

    2015-08-01

    The Mediterranean region has been identified as a global warming hotspot, where future climate impacts are expected to have significant consequences on societal and ecosystem well-being. To put ongoing trends of summer climate into the context of past natural variability, we reconstructed climate from maximum latewood density (MXD) measurements of Pinus heldreichii (1521-2010) and latewood width (LWW) of Pinus nigra (1617-2010) on Mt. Olympus, Greece. Previous research in the northeastern Mediterranean has primarily focused on inter-annual variability, omitting any low-frequency trends. The present study utilizes methods capable of retaining climatically driven long-term behavior of tree growth. The LWW chronology corresponds closely to early summer moisture variability (May-July, r = 0.65, p < 0.001, 1950-2010), whereas the MXD-chronology relates mainly to late summer warmth (July-September, r = 0.64, p < 0.001; 1899-2010). The chronologies show opposing patterns of decadal variability over the twentieth century (r = -0.68, p < 0.001) and confirm the importance of the summer North Atlantic Oscillation (sNAO) for summer climate in the northeastern Mediterranean, with positive sNAO phases inducing cold anomalies and enhanced cloudiness and precipitation. The combined reconstructions document the late twentieth—early twenty-first century warming and drying trend, but indicate generally drier early summer and cooler late summer conditions in the period ~1700-1900 CE. Our findings suggest a potential decoupling between twentieth century atmospheric circulation patterns and pre-industrial climate variability. Furthermore, the range of natural climate variability stretches beyond summer moisture availability observed in recent decades and thus lends credibility to the significant drying trends projected for this region in current Earth System Model simulations.

  6. Synoptic drivers of 400 years of summer temperature and precipitation variability on Mt. Olympus, Greece

    NASA Astrophysics Data System (ADS)

    Klesse, Stefan; Ziehmer, Malin; Rousakis, Georgios; Trouet, Valerie; Frank, David

    2014-09-01

    The Mediterranean region has been identified as a global warming hotspot, where future climate impacts are expected to have significant consequences on societal and ecosystem well-being. To put ongoing trends of summer climate into the context of past natural variability, we reconstructed climate from maximum latewood density (MXD) measurements of Pinus heldreichii (1521-2010) and latewood width (LWW) of Pinus nigra (1617-2010) on Mt. Olympus, Greece. Previous research in the northeastern Mediterranean has primarily focused on inter-annual variability, omitting any low-frequency trends. The present study utilizes methods capable of retaining climatically driven long-term behavior of tree growth. The LWW chronology corresponds closely to early summer moisture variability (May-July, r = 0.65, p < 0.001, 1950-2010), whereas the MXD-chronology relates mainly to late summer warmth (July-September, r = 0.64, p < 0.001; 1899-2010). The chronologies show opposing patterns of decadal variability over the twentieth century (r = -0.68, p < 0.001) and confirm the importance of the summer North Atlantic Oscillation (sNAO) for summer climate in the northeastern Mediterranean, with positive sNAO phases inducing cold anomalies and enhanced cloudiness and precipitation. The combined reconstructions document the late twentieth—early twenty-first century warming and drying trend, but indicate generally drier early summer and cooler late summer conditions in the period ~1700-1900 CE. Our findings suggest a potential decoupling between twentieth century atmospheric circulation patterns and pre-industrial climate variability. Furthermore, the range of natural climate variability stretches beyond summer moisture availability observed in recent decades and thus lends credibility to the significant drying trends projected for this region in current Earth System Model simulations.

  7. Summer foods of lesser scaup in subarctic taiga

    USGS Publications Warehouse

    Bartonek, J.C.; Murdy, H.W.

    1970-01-01

    Twenty-five adult and 38 juvenile lesser scaup (Aythya affinis) that were collected in taiga north of Great Slave Lake, Northwest Territories, had eaten almost entirely animal material (99 i?? 1 per cent, P < 0.05). Juveniles collected in mid-summer had tended to feed on free-swimming organisms such as Chaoborinae and Conchostraca; whereas juveniles collected in late summer had tended to feed, as did adults in June, on bottom-associated organisms such as amphipods, odonates, and corixids. Sampling aquatic organisms concomitantly with collecting ducks revealed that seeds, copepods, and cladocerans were seldom or never eaten; most other organisms were consumed in proportions that were not significantly different (P < 0.05) from those in the collected samples.

  8. The summer snow cover anomaly over the Tibetan Plateau and its association with simultaneous precipitation over the mei-yu-baiu region

    NASA Astrophysics Data System (ADS)

    Liu, Ge; Wu, Renguang; Zhang, Yuanzhi; Nan, Sulan

    2014-07-01

    The summer snow anomalies over the Tibetan Plateau (TP) and their effects on climate variability are often overlooked, possibly due to the fact that some datasets cannot properly capture summer snow cover over high terrain. The satellite-derived Equal-Area Scalable Earth grid (EASE-grid) dataset shows that snow still exists in summer in the western part and along the southern flank of the TP. Analysis demonstrates that the summer snow cover area proportion (SCAP) over the TP has a significant positive correlation with simultaneous precipitation over the mei-yu-baiu (MB) region on the interannual time scale. The close relationship between the summer SCAP and summer precipitation over the MB region could not be simply considered as a simultaneous response to the Silk Road pattern and the SST anomalies in the tropical Indian Ocean and tropical central-eastern Pacific. The SCAP anomaly has an independent effect and may directly modulate the land surface heating and, consequently, vertical motion over the western TP, and concurrently induce anomalous vertical motion over the North Indian Ocean via a meridional vertical circulation. Through a zonal vertical circulation over the tropics and a Kelvin wave-type response, anomalous vertical motion over the North Indian Ocean may result in an anomalous high over the western North Pacific and modulate the convective activity in the western Pacific warm pool, which stimulates the East Asia-Pacific (EAP) pattern and eventually affects summer precipitation over the MB region.

  9. Longitudinal and Vertical Spatial Gradients in the Distribution of Fish within a Canyon-shaped Reservoir

    NASA Astrophysics Data System (ADS)

    Vaek, Mojmír; Kubeka, Jan; Peterka, Jií; Ech, Martin; Dratík, Vladislav; Hladík, Milan; Prchalová, Marie; Frouzová, Jaroslava

    2004-09-01

    The large-scale spatial distribution of fish was investigated within a morphometrically simple canyon-shaped reservoir with a single major tributary and a longitudinal trophic gradient (ímov Reservoir, Czech Republic). Samples of fish were taken by Nordic survey gill nets (several mesh sizes from 8 to 70 mm knot to knot) installed as surface nets at several offshore areas located along the longitudinal axis of the reservoir. Surveys were carried out in late summer during 1999-2003. An obvious distribution gradient of fish was revealed along the longitudinal axis of the ímov Reservoir. The total relative fish abundance and biomass (catch per unit effort) decreased considerably from the upstream end of the reservoir toward the dam. Roach (Rutilus rutilus), bleak (Alburnus alburnus) and bream (Abramis brama) comprised the bulk of catches at all areas. Enhanced dominance of bream was observed in the fish assemblage at the uppermost, more eutrophic area of the reservoir. The highest number of fish species and the highest abundance of young-of-the-year fish were also observed in the tributary area. In the downstream part of the reservoir, gill net surveys along the vertical depth profiles indicated that offshore fish occupied mostly the epilimnion. Extreme flood events affected the ímov Reservoir, however, it seemed they had no significant impact on the gradients described. (

  10. Spectroscopic study of the seasonal variation of carbon monoxide vertical distribution above Kitt Peak

    NASA Technical Reports Server (NTRS)

    Pougatchev, N. S.; Rinsland, C. P.

    1995-01-01

    A method to retrieve elements of the carbon monoxide (CO) vertical distribution from ground-based high-resolution infrared solar spectra has been developed. The method is based on the fact that the total column amount retrieved by nonlinear least squares spectral fitting techniques depends on the shape of the assumed a priori profile and this dependence is a function of the absorption line intensity and the lower state energy of the transition. Four CO lines between 2057 and 2159/cm have been selected and the method has been tested on synthetic spectra. The CO total column content and average concentrations in two atmospheric layers (surface to 400 mbar and 400 mbar to the top of the atmosphere) can be retrieved with precisions of about 1% and less than 10%, respectively. Solar spectra recorded at Kitt Peak from 1982 to 1993 have been analyzed. The CO total column and the average concentration in the two layers show an asymmetrical seasonal cycle with extreme values of (1.1-2.1) x 10(exp 18) molecules cm(exp -2), (50-80) parts per billion by volume (ppbv) in the top layer and (80-160) ppbv in the bottom layer, and precisions of 1, 3, and 6%, respectively; a spring maximum and late summer minimum are observed.

  11. Ocean-atmosphere processes driving Indian summer monsoon biases in CFSv2 hindcasts

    NASA Astrophysics Data System (ADS)

    Narapusetty, Balachandrudu; Murtugudde, Raghu; Wang, Hui; Kumar, Arun

    2016-09-01

    This paper analyzes the role of the Indian Ocean (IO) and the atmosphere biases in generating and sustaining large-scale precipitation biases over Central India (CI) during the Indian summer monsoon (ISM) in the climate forecast system version 2 (CFSv2) hindcasts that are produced by initializing the system each month from January 1982 to March 2011. The CFSv2 hindcasts are characterized by a systematic dry monsoon bias over CI that deteriorate with forecast lead-times and coexist with a wet bias in the tropical IO suggesting a large-scale interplay between coupled ocean-atmosphere and land biases. The biases evolving from spring-initialized forecasts are analyzed in detail to understand the evolution of summer biases. The northward migration of the Inter Tropical Convergence Zone (ITCZ) that typically crosses the equator in the IO sector during April in nature is delayed in the hindcasts when the forecast system is initialized in early spring. Our analyses show that the delay in the ITCZ coexists with wind and SST biases and the associated processes project onto the seasonal evolution of the coupled ocean-atmosphere features. This delay in conjunction with the SST and the wind biases during late spring and early summer contributes to excessive precipitation over the ocean and leading to a deficit in rainfall over CI throughout the summer. Attribution of bias to a specific component in a coupled forecast system is particularly challenging as seemingly independent biases from one component affect the other components or are affected by their feedbacks. In the spring-initialized forecasts, the buildup of deeper thermocline in association with warmer SSTs due to the enhanced Ekman pumping in the southwest IO inhibits the otherwise typical northward propagation of ITCZ in the month of April. Beyond this deficiency in the forecasts, two key ocean-atmosphere coupled mechanisms are identified; one in the Arabian Sea, where a positive windstress curl bias in conjunction

  12. Climatology of summer Shamal wind in the Middle East

    NASA Astrophysics Data System (ADS)

    Yu, Yan; Notaro, Michael; Kalashnikova, Olga V.; Garay, Michael J.

    2016-01-01

    The Middle Eastern Shamal is a strong north-northwesterly wind, capable of lifting dust from the Tigris-Euphrates basin and transporting it to the Persian Gulf and Arabian Peninsula. The present study explores the poorly understood spatial and temporal variability of summer Shamal on the diurnal, seasonal, and interannual time scales, along with its influence on dust storm activity and sensitivity to global patterns of sea surface temperature using a comprehensive set of observational data. Statistics of the summer Shamal season are quantified for the first time, including its onset, termination, duration, and the occurrence of distinct break periods. Based on a multistation criteria, the mean onset and termination of the Shamal season occur on 30 May ± 16 days (1 standard deviation) and 16 August ± 22 days, respectively. Anomalously early (late) onset and termination of the Shamal season are typically associated with La Niña (El Niño) conditions, which favor (inhibit) the development of the Iranian heat low in spring and inhibit (favor) its persistence into late summer. Dust source regions in the Tigris-Euphrates basin and Kuwait, as well as southeastward dust transport during the summer Shamal, which cannot be detected by satellite aerosol products alone, are identified, for the first time, from the Multiangle Imaging Spectroradiometer plume motion vector products and confirmed by surface observations and lidar data. A close interrelationship has been revealed among summertime dust activity across the eastern Arabian Peninsula, frequency of Shamal days, and duration of the Shamal season on the interannual time scales.

  13. 'Endurance' Untouched (vertical)

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This navigation camera mosaic, created from images taken by NASA's Mars Exploration Rover Opportunity on sols 115 and 116 (May 21 and 22, 2004) provides a dramatic view of 'Endurance Crater.' The rover engineering team carefully plotted the safest path into the football field-sized crater, eventually easing the rover down the slopes around sol 130 (June 12, 2004). To the upper left of the crater sits the rover's protective heatshield, which sheltered Opportunity as it passed through the martian atmosphere. The 360-degree view is presented in a vertical projection, with geometric and radiometric seam correction.

  14. Gibberellic acid (GA3) effects on late season grapefruit peel oil composition

    USDA-ARS?s Scientific Manuscript database

    Gibberellic acid (GA3) is commonly applied to citrus fruit in the late summer/early autumn to delay peel maturation and extend late season quality. The effect of August/September GA3 application on oil gland composition of "Marsh" white grapefruit harvested in March 18 and April 16 from three groves...

  15. Total available carbohydrates in serviceberry after late dummer and fall burning

    Treesearch

    Benjamin Zamora; Thomas Gnojek

    2001-01-01

    Total available carbohydrate (TAC) storage and depletion was measured in late summer and fall burned and unburned serviceberry (Amelanchier alnifolia). The purpose of the study was to assess the influence of late season prescribed fire on the vigor of serviceberry, a key browse species on white-tailed deer (Odecoileus virginianus ochrourus) winter range in northeastern...

  16. Par Pond vegetation status Summer 1995 -- Summary

    SciTech Connect

    Mackey, H.E. Jr.; Riley, R.S.

    1996-01-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the newly emergent, shoreline aquatic plant communities of Par Pond began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level. These surveys continued in July, September, and late October, 1995. Communities similar to the pre-drawdown, Par Pond aquatic plant communities are becoming re-established. Emergent beds of maidencane, lotus, waterlily, and watershield are extensive and well developed. Cattail occurrence continued to increase during the summer, but large beds common to Par Pond prior to the drawdown have not formed. Estimates from SPOT HRV, remote sensing satellite data indicated that as much as 120 hectares of emergent wetlands vegetation may have been present along the Par Pond shoreline by early October, 1995. To track the continued development of macrophytes in Par Pond, future surveys throughout 1996 and 1997, along with the continued evaluation of satellite data to map the areal extent of the macrophyte beds of Par Pond, are planned.

  17. Mars' South Polar Cap in Summer

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Simultaneous infrared and visible images taken by the camera system on NASA's Mars Odyssey spacecraft show the martian south polar cap in late summer. The black areas in the infrared image are at a temperature near -125 degrees Celsius (-193 degrees Fahrenheit) and correspond to solid carbon dioxide ice. The purple regions are areas of exposed water ice at a temperature near -95 degrees Celsius (-139degrees Fahrenheit). The warmest (red) areas are classic 'dark lanes' of frost-free soil at a temperature near -55 degrees Celsius(-67 degrees Fahrenheit). The right panel shows the same infrared image with a visible image superimposed. The infrared image is approximately 32 kilometers (20 miles) wide.

    The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the 2001 Mars Odyssey mission for NASA's Office of Space Science in Washington, D.C. Investigators at Arizona State University in Tempe, the University of Arizona in Tucson and NASA's Johnson Space Center, Houston, operate the science instruments. Additional science partners are located at the Russian Aviation and Space Agency and at Los Alamos National Laboratories, New Mexico. Lockheed Martin Astronautics, Denver, is the prime contractor for the project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL.

  18. Artists Paint ... Summer: Grade 2

    ERIC Educational Resources Information Center

    Herberholz, Barbara

    2012-01-01

    A humid summer haze covers the River Seine and the grassy bank where young men and boys go swimming on Sunday. Everything seems so quiet, still, and very hot. They wear hats to protect them from the hot sun. The artist Georges Seurat used warm tones to give viewers the feeling of the hot sun. Seurat was trying to catch the dazzle of hot sunlight…

  19. Summer of Innovation Kick Off

    NASA Image and Video Library

    2010-06-09

    A performer from Los Angeles Hamilton High School's Kid Tribe entertains teachers and middle school students during the kick off of NASA's Summer of Innovation program at the Jet Propulsion Laboratory in Pasadena, Calif., Thursday, June 10, 2010. Through the program, NASA will engage thousands of middle school students and teachers in stimulating math and science-based education programs with the goal of increasing the number of future scientists, mathematicians, and engineers. Photo Credit: (NASA/Bill Ingalls)

  20. Summer of Innovation Kick Off

    NASA Image and Video Library

    2010-06-09

    NASA astronaut Leland Melvin welcomes teachers and middle school students to the kick off of NASA's Summer of Innovation program at the Jet Propulsion Laboratory in Pasadena, Calif., Thursday, June 10, 2010. Through the program, NASA will engage thousands of middle school students and teachers in stimulating math and science-based education programs with the goal of increasing the number of future scientists, mathematicians, and engineers. Photo Credit: (NASA/Bill Ingalls)

  1. Summer of Innovation Kick Off

    NASA Image and Video Library

    2010-06-09

    Jet Propulsion Laboratory Director Dr. Charles Elachi speaks with teachers and middle school students during the kick off of NASA's Summer of Innovation program at JPL in Pasadena, Calif., Thursday, June 10, 2010. Through the program, NASA will engage thousands of middle school students and teachers in stimulating math and science-based education programs with the goal of increasing the number of future scientists, mathematicians, and engineers. Photo Credit: (NASA/Bill Ingalls)

  2. Summer of Innovation Kick Off

    NASA Image and Video Library

    2010-06-09

    Teachers and middle school students react to performers from Los Angeles Hamilton High School's Kid Tribe during the kick off of NASA's Summer of Innovation program at the Jet Propulsion Laboratory in Pasadena, Calif., Thursday, June 10, 2010. Through the program, NASA will engage thousands of middle school students and teachers in stimulating math and science-based education programs with the goal of increasing the number of future scientists, mathematicians, and engineers. Photo Credit: (NASA/Bill Ingalls)

  3. Summer of Innovation Kick Off

    NASA Image and Video Library

    2010-06-09

    Performers from Los Angeles Hamilton High School's Kid Tribe entertain teachers and middle school students during the kick off of NASA's Summer of Innovation program at the Jet Propulsion Laboratory in Pasadena, Calif., Thursday, June 10, 2010. Through the program, NASA will engage thousands of middle school students and teachers in stimulating math and science-based education programs with the goal of increasing the number of future scientists, mathematicians, and engineers. Photo Credit: (NASA/Bill Ingalls)

  4. Summer of Innovation Kick Off

    NASA Image and Video Library

    2010-06-09

    NASA Administrator Charles Bolden speaks with teachers and middle school students during the kick off of NASA's Summer of Innovation program at the Jet Propulsion Laboratory in Pasadena, Calif., Thursday, June 10, 2010. Through the program, NASA will engage thousands of middle school students and teachers in stimulating math and science-based education programs with the goal of increasing the number of future scientists, mathematicians, and engineers. Photo Credit: (NASA/Bill Ingalls)

  5. Summer of Innovation Kick Off

    NASA Image and Video Library

    2010-06-09

    Julie Townsend, JPL Engineer, talks about her experiences to teachers and middle school students during the kick off of NASA's Summer of Innovation program at the Jet Propulsion Laboratory in Pasadena, Calif., Thursday, June 10, 2010. Through the program, NASA will engage thousands of middle school students and teachers in stimulating math and science-based education programs with the goal of increasing the number of future scientists, mathematicians, and engineers. Photo Credit: (NASA/Bill Ingalls)

  6. Summer of Innovation Kick Off

    NASA Image and Video Library

    2010-06-09

    NASA astronaut Stephanie Wilson talks about her experiences to teachers and middle school students during the kick off of NASA's Summer of Innovation program at the Jet Propulsion Laboratory in Pasadena, Calif., Thursday, June 10, 2010. Through the program, NASA will engage thousands of middle school students and teachers in stimulating math and science-based education programs with the goal of increasing the number of future scientists, mathematicians, and engineers. Photo Credit: (NASA/Bill Ingalls)

  7. Summer of Innovation Kick Off

    NASA Image and Video Library

    2010-06-09

    Rapper and Actor Daniel Curtis Lee performs during the kick off of NASA's Summer of Innovation program at the Jet Propulsion Laboratory in Pasadena, Calif., Thursday, June 10, 2010. Through the program, NASA will engage thousands of middle school students and teachers in stimulating math and science-based education programs with the goal of increasing the number of future scientists, mathematicians, and engineers. Photo Credit: (NASA/Bill Ingalls)

  8. Summer of Innovation Kick Off

    NASA Image and Video Library

    2010-06-09

    NASA astronaut Leland Melvin signs autographs to middle school students during the kick off of NASA's Summer of Innovation program at the Jet Propulsion Laboratory in Pasadena, Calif., Thursday, June 10, 2010. Through the program, NASA will engage thousands of middle school students and teachers in stimulating math and science-based education programs with the goal of increasing the number of future scientists, mathematicians, and engineers. Photo Credit: (NASA/Bill Ingalls)

  9. Summer of Innovation Kick Off

    NASA Image and Video Library

    2010-06-09

    NASA Administrator Charles Bolden signs autographs to middle school students during the kick off of NASA's Summer of Innovation program at the Jet Propulsion Laboratory in Pasadena, Calif., Thursday, June 10, 2010. Through the program, NASA will engage thousands of middle school students and teachers in stimulating math and science-based education programs with the goal of increasing the number of future scientists, mathematicians, and engineers. Photo Credit: (NASA/Bill Ingalls)

  10. Summer of Innovation Kick Off

    NASA Image and Video Library

    2010-06-09

    NASA Administrator Charles Bolden, center, listens as NASA astronaut Leland Melvin welcomes teachers and middle school students to the kick off of NASA's Summer of Innovation program at the Jet Propulsion Laboratory in Pasadena, Calif., Thursday, June 10, 2010. Through the program, NASA will engage thousands of middle school students and teachers in stimulating math and science-based education programs with the goal of increasing the number of future scientists, mathematicians, and engineers. Photo Credit: (NASA/Bill Ingalls)

  11. SNOWMASS (DPF Community Summer Study)

    SciTech Connect

    Cronin-Hennessy, et al, Daniel

    2013-08-06

    The 2013 Community Summer Study, known as Snowmass," brought together nearly 700 physicists to identify the critical research directions for the United States particle physics program. Commissioned by the American Physical Society, this meeting was the culmination of intense work over the past year by more than 1000 physicists that defined the most important questions for this field and identified the most promising opportunities to address them. This Snowmass study report is a key resource for setting priorities in particle physics.

  12. Chemical and Biological Summer Poisons

    PubMed Central

    Lees, Ronald E. M.

    1972-01-01

    Summer has its own special poisoning hazards for the vacationer, gardener or outdoorsman. Because of the comparative variety of accidental human poisonings from contact with these seasonal toxic substances, either artificial or natural, many family physicians are unfamiliar with their effects. Some of us, unfortunately, will be called upon to deal with them over the next few months. This article highlights some of the hazards, outlines their toxicology and summarizes the treatment of the poisoned patient. PMID:20468771

  13. Artists Paint ... Summer: Grade 2

    ERIC Educational Resources Information Center

    Herberholz, Barbara

    2012-01-01

    A humid summer haze covers the River Seine and the grassy bank where young men and boys go swimming on Sunday. Everything seems so quiet, still, and very hot. They wear hats to protect them from the hot sun. The artist Georges Seurat used warm tones to give viewers the feeling of the hot sun. Seurat was trying to catch the dazzle of hot sunlight…

  14. Summer of Innovation Kick Off

    NASA Image and Video Library

    2010-06-09

    Jet Propulsion Laboratory Manager of Elementary and Secondary Education David Seidel motivates teachers and middle school students during the kick off of NASA's Summer of Innovation program at the Jet Propulsion Laboratory in Pasadena, Calif., Thursday, June 10, 2010. Through the program, NASA will engage thousands of middle school students and teachers in stimulating math and science-based education programs with the goal of increasing the number of future scientists, mathematicians, and engineers. Photo Credit: (NASA/Bill Ingalls)

  15. Summer of Innovation Kick Off

    NASA Image and Video Library

    2010-06-09

    A group of Jet Propulsion Laboratory (JPL) engineers are recognized during the kick off of NASA's Summer of Innovation program at JPL in Pasadena, Calif., Thursday, June 10, 2010. Through the program, NASA will engage thousands of middle school students and teachers in stimulating math and science-based education programs with the goal of increasing the number of future scientists, mathematicians, and engineers. Photo Credit: (NASA/Bill Ingalls)

  16. Summer Series 2012 - Shashi Buluswar

    ScienceCinema

    Shashi Buluswar

    2016-07-12

    The last installment of the "Summer Series of Conversations" took place Wednesday, August 1, with guest Shashi Buluswar, the executive director of the LBNL Institute for Globally Transformative Technologies (LIGTT). The Institute seeks to foster the discovery, development and deployment of a generation of low-carbon, affordable technologies that will advance sustainable methods to fight global poverty. The event, was hosted by Public Affairs Head Jeff Miller.

  17. Summer Series 2012 - Shashi Buluswar

    SciTech Connect

    Shashi Buluswar

    2012-08-08

    The last installment of the "Summer Series of Conversations" took place Wednesday, August 1, with guest Shashi Buluswar, the executive director of the LBNL Institute for Globally Transformative Technologies (LIGTT). The Institute seeks to foster the discovery, development and deployment of a generation of low-carbon, affordable technologies that will advance sustainable methods to fight global poverty. The event, was hosted by Public Affairs Head Jeff Miller.

  18. Summer roosting by adult male seminole bats in the Ouachita Mountains, Arkansas

    Treesearch

    Roger W. Perry; Ronald E. Thill

    2007-01-01

    We used radiotelemetry to locate 51 diurnal roosts for 17 male Seminole bats (Lasiurus seminolus) during late spring and early summer, 2000–2005. We quantified characteristics of roost trees and sites surrounding roosts and compared those measurements with random trees and random locations. All but two roosts were located in the foliage of large...

  19. 75 FR 2820 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Quota Transfer

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-19

    ... Flounder, Scup, and Black Sea Bass Fishery Management Plan (FMP), which was published on December 17, 1993... implementing the Summer Flounder, Scup, and Black Sea Bass FMP to address late-season circumstances that... could be approved, even if the transfer request is made in the subsequent fishing year, and would be...

  20. Late-Flowering Species are Sensitive to Warming

    NASA Astrophysics Data System (ADS)

    Carter, D. L.; VanderWeide, B. L.

    2012-12-01

    Phenological advancement is one of the most prevalent responses of vegetation to warming. The prevailing view is that that early flowering species are particularly sensitive warming, with greater phenological advancement per °C warming relative to later flowering species. However, we observed a three to four month advancement of late flowering species to the extreme warmth of 2012, which motivated us to ask quantitatively whether late flowering species are indeed less sensitive to warming. We focused on responses to inter-annual variation in mean monthly, seasonal, and annual temperatures, using species for which we have ≥10 observations of first flowering near Manhattan, KS between 1891 and 2012 (n = 259). As many other studies have found, early flowering species advanced flowering with warmer temperatures during the year preceding flowering, while late flowering species appeared insensitive to warming during the year preceding flowering. At the seasonal time scale, however, both early and late flowering species responded similarly to spring warming, while late flowering species delayed flowering in response to summer warmth. This divergent response created the illusion that later flowering species were insensitive to temperatures during the year preceding flowering. When absolute values of sensitivities to temperature were summed across months, late flowering species exhibited greater sensitivity to temperature than early flowering species. Late-flowering species were also the most sensitive to variation in precipitation and advanced flowering when summers were wet. We therefore speculate that flowering for late species is delayed by warm, dry summers because both warmth and dryness exacerbate plant water stress and delay growth. Furthermore, warm spring temperatures might allow both early and late flowering species to more quickly attain size or developmental requirements for flowering. Advanced flowering in 2012 provides an extreme example of some typically

  1. Ticket to a First Class Summer.

    ERIC Educational Resources Information Center

    Instructor, 1987

    1987-01-01

    Eight reproducible pages are offered for teachers to use as a summer send-off package which contains activities extending from a child's backyard to outer space. A list of books for summer reading is included. (MT)

  2. Oxygen and carbon stable isotopes in coast redwood tree rings respond to spring and summer climate signals

    NASA Astrophysics Data System (ADS)

    Johnstone, James A.; Roden, John S.; Dawson, Todd E.

    2013-12-01

    variability in the oxygen and carbon isotope composition of tree ring cellulose was investigated in coast redwood (Sequoia sempervirens) from three sites in coastal Northern California. Middle and late wood samples from annual tree rings were compared to regional climate indices and gridded ocean-atmosphere fields for the years 1952-2003. The strongest climate-isotope relationship (r = 0.72) was found with summer (June-September) daily maximum temperature and middle wood δ13, which also responds positively to coastal sea surface temperature and negatively to summer low cloud frequency. Late wood δ18O reflects a balance between 18O-enriched summer fog drip and depleted summer rainwater, while a combined analysis of late wood δ18O and δ13C revealed sensitivity to the sign of summer precipitation anomalies. Empirical orthogonal function analysis of regional summer climate indices and coast redwood stable isotopes identified multivariate isotopic responses to summer fog and drought that correspond to atmospheric circulation anomalies over the NE Pacific and NW U.S. The presence of regional climate signals in coast redwood stable isotope composition, consistent with known mechanistic processes and prior studies, offers the potential for high-resolution paleoclimate reconstructions of the California current system from this long-lived tree species.

  3. Sea surface temperature associations with the Indian summer monsoon

    NASA Astrophysics Data System (ADS)

    Terray, P.; Delecluse, P.; Labattu, S.; Terray, L.

    2003-04-01

    This paper uses recent gridded data and Atmospheric General Circulation Model (AGCM) simulations in order to assess the relationships between interannual variability of the Indian Summer Monsoon (ISM) and Sea Surface Temperature (SST) anomaly patterns over the Indian and Pacific oceans. Interannual variability of ISM rainfall and dynamical indices for the traditional summer monsoon season (June-September) are strongly influenced by rainfall and circulation anomalies observed during August and September, or the Late Indian Summer Monsoon (LISM). Southern Indian Ocean SST acts as a major boundary forcing for the LISM system. Strong (weak) LISMs are preceded by significant positive (negative) SST anomalies in the southeastern subtropical Indian Ocean, off Australia. These SST anomalies are highly persistent and affect the northwestward translation of the Mascarene high from austral to boreal summer. The southeastward (northwestward) shift of this subtropical high associated with cold (warm) SST anomalies off Australia causes a weakening (strengthening) of the whole monsoon circulation through a modulation of the local Hadley cell during the LISM. Furthermore, it is suggested that the Mascarene high interacts with the underlying SST anomalies through a positive dynamical feedback mechanism, maintaining its anomalous position during the LISM. Southeastern Indian Ocean SST anomalies during boreal winter are mainly linked to subtropical Indian Ocean dipole events, studied by Behera and Yamagata (2001), and to the El Niño-Southern Oscillation phenomenon. An El Niño event and the associated warm SST anomalies over the southeastern Indian Ocean during boreal winter may play a key role in the development of a strong ISM by strengthening the local Hadley circulation during the LISM. On the other hand, a developing La Niña event in boreal summer may also enhance the east-west Walker circulation and the monsoon.

  4. Late Glacial and Late Holocene Paleohydrology of Central Asia

    NASA Astrophysics Data System (ADS)

    Aichner, B.; Feakins, S. J.; Mischke, S.; Herzschuh, U.; Liu, X.; Rajabov, I.; Wang, Y.; Heinecke, L.

    2013-12-01

    The goal of this study is to deepen the understanding of past climatological, ecological and hydrological changes in Central Asia, by means of organic geochemical proxies and in close cooperation with other work groups providing biological and sedimentological data. We analysed an 8 m sediment core from Lake Karakuli, a small open freshwater lake situated at an altitude of 3,657 m between the massifs of Muztagh Ata (7,546 m) and Kongur Shan (7,719 m) in western China. Additional work is in progress on a 12 m core derived from Lake Karakul in Tajikistan, a large closed saline lake situated in a tectonic graben structure at an altitude of 3,928 m. The distance between the two lakes is 130 km and basal ages of the cores are ca. 4.7 ka BP (China) and ca. 27 ka BP (Tajikistan). The lake catchments may be classified as alpine steppe to alpine deserts with mean annual temperature of ca. 0 °C and mean annual precipitation of ca. 100 mm, respectively. Summer precipitation, associated with the Indian monsoon, accounts for <30% of the annual total, whereas most precipitation is supplied by mid-latitude Westerlies between March and May. In the small Chinese lake long-chain fatty acids (FAs) were mainly attributed to terrestrial sources by compound-specific carbon isotopic analyses. In contrast δ13C values up to -14‰ for abundant mid-chain FAs suggest aquatic origins in the large Lake Karakul. Hydrogen isotopic variability is ca. 15‰ in the mid-Holocene record and ca. 60‰ in the first data derived from the Late Glacial record. In the latter, the most pronounced change from higher to lower δD-values of aquatic biomarkers is tentatively interpreted as change from arid to more humid conditions at the Late Glacial to Holocene transition. Since in Central Asia isotopic variability of precipitation mainly correlates with temperature, we interpret high resolution δD data of terrestrial long-chain FAs in the younger core to mainly reflect mid-Holocene temperature variations

  5. Late recurrence of medulloblastoma.

    PubMed

    Stevens, Brittney; Razzaqi, Faisal; Yu, Lolie; Craver, Randall

    2008-01-01

    We present a child with a cerebellar medulloblastoma, diagnosed at age three, treated with near total surgical resection, radiotherapy, and chemotherapy, that recurred 13 years after the initial diagnosis. This late recurrence exceeds the typical 10-year survival statistics that are in common use, and exceeds the Collins rule. Continued follow-up of these children is justified to increase the likelihood of detecting these late recurrences early and to learn more about these late recurrences.

  6. Close the Achievement Gap with Summer Learning

    ERIC Educational Resources Information Center

    Huggins, Gary

    2012-01-01

    Summer vacation from school can bring afternoons at the swimming pool, family vacations, and maybe a spirit-filled summer camp that ignites a passion for art or rock climbing. But for many children, summer also means setbacks in learning that take a tremendous toll on teaching and student performance over time. PTA leaders can make a vital…

  7. Summer Session: A Time for Innovation

    ERIC Educational Resources Information Center

    Mola, Monty

    2013-01-01

    Summer is almost here (at least for those of us who teach semesters). Many of us are taking a well-deserved break to spend time with our families, conduct research, travel, and myriad other activities. Some of us, however, will be teaching summer school. For those of us lucky enough to be teaching this summer, we have one suggestion: Be bold!…

  8. Summer Session Organizational Models at Canadian Universities

    ERIC Educational Resources Information Center

    Kops, Bill

    2010-01-01

    The issue of summer session organizational models continues to be of interest to summer session deans/directors and university administrators. The University of Victoria surveyed Canadian universities on this issue in 1994. Based on a similar survey done in 2009, this paper updates the status of Canadian university summer session organizational…

  9. Summer Session: A Time for Innovation

    ERIC Educational Resources Information Center

    Mola, Monty

    2013-01-01

    Summer is almost here (at least for those of us who teach semesters). Many of us are taking a well-deserved break to spend time with our families, conduct research, travel, and myriad other activities. Some of us, however, will be teaching summer school. For those of us lucky enough to be teaching this summer, we have one suggestion: Be bold!…

  10. Finding Funds to Move Summer Learning Forward

    ERIC Educational Resources Information Center

    Seidel, Bob

    2015-01-01

    Summer learning loss creates a permanent drag on the US education system. With the generous support of the Charles Stewart Mott Foundation, the National Summer Learning Association (NSLA) developed "Moving Summer Learning Forward: A Strategic Roadmap for Funding in Tough Times" to provide out-of-school time programs, school districts,…

  11. Finding Funds to Move Summer Learning Forward

    ERIC Educational Resources Information Center

    Seidel, Bob

    2015-01-01

    Summer learning loss creates a permanent drag on the US education system. With the generous support of the Charles Stewart Mott Foundation, the National Summer Learning Association (NSLA) developed "Moving Summer Learning Forward: A Strategic Roadmap for Funding in Tough Times" to provide out-of-school time programs, school districts,…

  12. 46 CFR 45.53 - Summer freeboard.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Summer freeboard. 45.53 Section 45.53 Shipping COAST... Summer freeboard. (a) Except as required in paragraph (c) of this section, the minimum freeboard in summer for a type A vessel is F in the following formula modified by the corrections in this subpart:...

  13. Summer Reading Lists: Research and Recommendations

    ERIC Educational Resources Information Center

    Lindley, Sarah; Giles, Rebecca M.; Tunks, Karyn

    2016-01-01

    Decades of research have focused on the impact of summer learning loss and effective tools in stemming the flow of knowledge lost during summer break. While reading lists have become a standard practice for addressing students' needs to maintain learning levels over the summer months, very little research has been conducted on the book lists…

  14. Shift in Indian summer monsoon onset during 1976/1977

    NASA Astrophysics Data System (ADS)

    Sahana, A. S.; Ghosh, Subimal; Ganguly, Auroop; Murtugudde, Raghu

    2015-05-01

    The Indian summer monsoon rainfall (ISMR) contributes nearly 80% of the annual rainfall over India and has a significant influence on the country’s gross domestic product through the agricultural sector. Onset of the ISMR displays substantial interannual variability and controls the crop calendar and hence the agricultural output. This variability is traditionally linked to sea surface temperature (SST) anomalies over the tropical Pacific Ocean. The tropical Pacific SST underwent a regime shift during 1976/77. We report a prominent delay in the Indian summer monsoon (ISM) onset following the regime shift. The onset dates are computed with the Hydrologic Onset and Withdrawal Index, based on vertically integrated moisture transport over the Arabian Sea (AS). The shift in onset is found to be due to the change in moisture availability over the AS. A delay in the development of easterly vertical shear reduces northward-propagating intraseasonal variability during May-June, limiting the moisture supply from the equatorial Indian Ocean (IO) to the AS. This, along with enhanced precipitation over the IO during the pre-monsoon, drives a reduction in moisture availability over the AS region from pre- to post-1976/77, delaying the ISM onset in recent decades. Our findings highlight the need for the re-assessment of the crop calendar in India, which is now based on the mean onset date computed from long-term data, without considering the regime shift or trends in onset.

  15. Summer Research Apprentice Program report. [Summer Research Apprentice Program

    SciTech Connect

    Curington, B.

    1982-01-01

    The Summer Research Apprentice Program is designed to provide students with their first look at college life while preparing them for possible careers in mathematics, science and engineering. The 23 students, enrolled as college freshmen for 8 hours of college credit, took courses in Trigonometry, College Algebra and introduction to Research (4 students were enrolled in Calculus 1 instead of Trigonometry and College Albebra). During this third year of operation, refinements were made in both the administration of the program and in the method of implementation.

  16. Cloud-Scale Vertical Velocity and Turbulent Dissipation Rate Retrievals

    DOE Data Explorer

    Shupe, Matthew

    2013-05-22

    Time-height fields of retrieved in-cloud vertical wind velocity and turbulent dissipation rate, both retrieved primarily from vertically-pointing, Ka-band cloud radar measurements. Files are available for manually-selected, stratiform, mixed-phase cloud cases observed at the North Slope of Alaska (NSA) site during periods covering the Mixed-Phase Arctic Cloud Experiment (MPACE, late September through early November 2004) and the Indirect and Semi-Direct Aerosol Campaign (ISDAC, April-early May 2008). These time periods will be expanded in a future submission.

  17. Multicolored Vertical Silicon Nanowires

    SciTech Connect

    Seo, Kwanyong; Wober, Munib; Steinvurzel, P.; Schonbrun, E.; Dan, Yaping; Ellenbogen, T.; Crozier, K. B.

    2011-04-13

    We demonstrate that vertical silicon nanowires take on a surprising variety of colors covering the entire visible spectrum, in marked contrast to the gray color of bulk silicon. This effect is readily observable by bright-field microscopy, or even to the naked eye. The reflection spectra of the nanowires each show a dip whose position depends on the nanowire radii. We compare the experimental data to the results of finite difference time domain simulations to elucidate the physical mechanisms behind the phenomena we observe. The nanowires are fabricated as arrays, but the vivid colors arise not from scattering or diffractive effects of the array, but from the guided mode properties of the individual nanowires. Each nanowire can thus define its own color, allowing for complex spatial patterning. We anticipate that the color filter effect we demonstrate could be employed in nanoscale image sensor devices.

  18. A World Vertical Network.

    DTIC Science & Technology

    1980-02-01

    and continental levelling nets into a unifiled World Vertical Network. OD ,~ 173 OITON F I OV 5 I OSOLEI tnc las 9if led SECURITY CLASSIP CATION O T...rp,0p,Xp is T(P) = V(P) - U (P) (2.2) The gravity potential of the Earth is W(P) = V(P) + ((P) (2.3) where o ( P) = w rp’ cos 2 Op corresponds to the...is, therefore, A W(P,Q) = U(P) + T(P) + 0 (P) - U(Q) - T(Q) - o (Q) (2.4) With both P and Q on the Earth’s surface, the uncertainties in the calculated

  19. Youth Indicators of Late-M Dwarfs

    NASA Astrophysics Data System (ADS)

    Feldman, Daniel; Cruz, K.; Lépine, S.; Alpert, N.

    2011-01-01

    We present a study in which we searched for a correlation between weak Na absorption doublet (8183Å, 8194Å) and strong H-Alpha emission (6563Å) in late-M dwarf stars (M6-M9), as both are indicative of youth. Our sample consists of late-M Dwarfs from the LSPM Survey (Lépine and Shara, 2005), which contain stars with measured proper motions of mu > 40 mas/yr. Measurements for emission and absorption strength were made using spectral indices. Our preliminary results are presented; future work will include a similar analysis of early type M Dwarfs, as well as kinematics. This work was funded by the CUNY Summer Undergraduate Research Program, as well as the CUNY Macaulay Honors College, and we acknowledge the hospitality of the American Museum of Natural History.

  20. Direct Observation of Ultralow Vertical Emittance using a Vertical Undulator

    SciTech Connect

    Wootton, Kent

    2015-09-17

    In recent work, the first quantitative measurements of electron beam vertical emittance using a vertical undulator were presented, with particular emphasis given to ultralow vertical emittances [K. P. Wootton, et al., Phys. Rev. ST Accel. Beams, 17, 112802 (2014)]. Using this apparatus, a geometric vertical emittance of 0.9 #6;± 0.3 pm rad has been observed. A critical analysis is given of measurement approaches that were attempted, with particular emphasis on systematic and statistical uncertainties. The method used is explained, compared to other techniques and the applicability of these results to other scenarios discussed.

  1. Observation of picometer vertical emittance with a vertical undulator.

    PubMed

    Wootton, K P; Boland, M J; Dowd, R; Tan, Y-R E; Cowie, B C C; Papaphilippou, Y; Taylor, G N; Rassool, R P

    2012-11-09

    Using a vertical undulator, picometer vertical electron beam emittances have been observed at the Australian Synchrotron storage ring. An APPLE-II type undulator was phased to produce a horizontal magnetic field, which creates a synchrotron radiation field that is very sensitive to the vertical electron beam emittance. The measured ratios of undulator spectral peak heights are evaluated by fitting to simulations of the apparatus. With this apparatus immediately available at most existing electron and positron storage rings, we find this to be an appropriate and novel vertical emittance diagnostic.

  2. Atmospheric moisture budget and its regulation on the variability of summer precipitation over the Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Wang, Ziqian; Duan, Anmin; Yang, Song; Ullah, Kalim

    2017-01-01

    Based on station observations and reanalysis data sets, the atmospheric moisture budget and its critical role in regulating the variability of summer precipitation over the Tibetan Plateau (TP) are investigated. Results indicate that the yearly variability of summer precipitation over the southern TP (STP) is mainly controlled by remote moisture transport. Local surface evaporation presents an infinitesimal interannual fluctuation, but it cannot be ignored since it is a large component of total precipitation amount in every summer. Although the incoming moisture transport at the western boundary of STP is much weaker than that at the southern boundary, it primarily influences the temporal variation of STP summer precipitation. Further analysis shows that the summer North Atlantic Oscillation (NAO) also possesses a significant impact on the variation of STP summer precipitation. A strong NAO apparently weakens the moisture transport at the western boundary, inducing less precipitation over the STP. When the NAO is strong, wave-activity flux obviously diverges eastward from the subtropical high over northwestern Europe. Then such flux converges toward the western TP, which weakens the baroclinic vertical structure of atmospheric circulation over the TP. The NAO also influences the meridional position of the Asian jet stream and modulates the specific humidity and moisture transport at the western boundary of STP. In addition, the dynamic processes of the atmosphere are more important than the thermodynamic processes in regulating the variability of TP summer precipitation.

  3. [Clinical application of maxillary sinus lift with Summers osteotome].

    PubMed

    Zhou, Lei; Xu, Shu-Lan; Xu, Shi-Tong; Huang, Jian-Sheng; Song, Guang-Bao; Zhang, Xue-Yang

    2008-06-01

    To introduce and evaluate the procedure and the effect of maxillary sinus lift with closed technique by Summers osteotome, bone grafting and simultaneous implant placement. 66 cases with severely resorbed alveolar bone in maxillary posterior region received sinus lift with Summers osteotome, simultaneously bone grafting and implants placement. The final restoration was finished at 6 months postoperatively. The operation procedure were eventless in the 66 cases, the sinus floor were elevated by 2-5 mm, three-dimensional reconstruction of the CT scan pictures showed the smooth dome profile of the lifting sites and no signs of laceration on the membrane, and there were no maxillary antritis after operation. After 6 months, no significantly bone graft resorption and good osseointegration were noticed in X-ray imaging. The final restoration was finished at this time. 12-24 months after the restoration, all implants inserted were remain, the hard and soft tissue were healthy, prosthesis were stable and functioned. X-ray showed good osseointegration in the lifting sites, the vertical resorption around the implants were less than 1 mm. With properly use of Summers osteotome, scraps of the bone in the implant sockets can be pushed into the sinus, these autogenous bone scraps were in favor of the osseogenesis and the sinus floor can be easily elevated by the method with very infrequent complications. It enlarged indication of dental implants and avoided operation of harvesting autogenous bone in other site. The method is simple and valuable to clinical application.

  4. Mapping High Latitude Gravity Wave Amplitudes over Antarctica during Summer

    NASA Astrophysics Data System (ADS)

    Badenhausen, P.; Millan, R. M.; Gerrard, A. J.

    2015-12-01

    Appropriate inclusion of gravity wave amplitudes into general circulation models is required to get accurate atmospheric circulation characteristics. However, high latitude gravity wave amplitudes are particularly difficult to obtain due to the challenging experimental and logistical constraints in these regions. In this study, we present gravity wave climatology of high latitudes during austral summer conditions over the Antarctic continent. These data were obtained using high-resolution GPS measurements aboard long duration high altitude balloon flights that were flown as part of the NASA Balloon Array for Radiation-belt Relativistic Electron Losses (BARREL) mission in December 2013-February 2014 and December 2012-February 2013. The results show increased gravity wave activity along the coast of the Antarctic continent, particularly over the Peninsula and Halley Bay, whereas at higher latitudes, particularly over regions near the South Pole, gravity wave amplitudes decrease substantially. Through use of horizontal winds data, we obtained measurements of the vertical transport of horizontal momentum fluxes, which were unusually high for the summer high latitude lower stratosphere. Such unique measurements as these are immediately applicable to understanding of upwelling in the summer middle atmosphere as well as to the formation of overlaying mesospheric clouds formation.

  5. Large Holocene summer temperature oscillations and impact on the peopling of the northeastern Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Hou, Juzhi; Huang, Yongsong; Zhao, Jiangtao; Liu, Zhonghui; Colman, Steve; An, Zhisheng

    2016-02-01

    Summer temperatures on the Tibetan Plateau (TP) significantly affect stability of glaciers that provide steady water resources to nearly half of the world population. However, lack of reliable, long-term proxy records greatly impedes understanding of regional temperature sensitivity to climate forcings. Here we present a 16 ka long, alkenone-based summer temperature record from Lake Qinghai, northeastern TP that demonstrates major regional temperature response to changes in summer insolation and Atlantic Meridional Overturning Circulation during the Holocene and late glacial. Importantly, we find a period of sustained summer temperature decline (>4°C) between 5 and 3.5 ka, which coincides with expansion of Barents Sea ice coverage and is likely driven by intensification of the Westerlies. This unusually long and pronounced regional cooling event likely delayed permanent human settlements on the high-altitude regions (>3000 m) of the TP by at least 500 years.

  6. South-north dipolar pattern around mid-1990s in Korean summer rainfall variability

    NASA Astrophysics Data System (ADS)

    Choi, Jae-Won; Cha, Yumi; Kim, Hae-Dong

    2017-06-01

    From the time series of rainfall in summer (June, July and August) in South and North Koreas for recent 28 years (1981-2008), rainfall has significantly increased in South Korea while it has significantly decreased in North Korea since 1996. In particular, the decreasing trend of summer rainfall in North Korea was more conspicuous during the second Changma (late August - mid-September). This characteristic was also found in the south-north dipolar pattern based on 1996 by empirical orthogonal function analysis using summer rainfall observed in all weather observation stations in South and North Korea. The decreasing rainfall trend in North Korea was found to be associated with the weakening of convection by anomalous northeasterlies from anomalous anticyclone centered on around Baikal Lake during summer. On the other hand, the increasing rainfall trend of South Korea was associated with the strengthened anomalous cyclone in the southern region of China, which in turn strengthened anomalous southwesterlies.

  7. Maintenance of Northern Summer Stationary Waves in a GCM.

    NASA Astrophysics Data System (ADS)

    Ting, Mingfang

    1994-11-01

    The maintenance of northern summer stationary waves is studied with data from a 15-year integration of the general circulation model (GCM) experiment performed at the Geophysical Fluid Dynamics Laboratory. The model has relatively high resolution (rhomboidal 30 wavenumbers, 9 vertical levels) and simulates the summertime stationary waves reasonably well.A steady, linear, baroclinic model is used to understand the various forcing mechanisms for the northern summer stationary waves. The linear model response to global diabatic heating is found to play a dominant role in maintaining the summertime stationary waves in the GCM, especially in the subtropics. This response to diabatic heating shows a baroclinic structure in the vertical with a node at about = 0.5. On the other hand, stationary nonlinear interaction terms are found to be largely responsible for the extratropical, equivalent barotropic stationary wave features. It is hypothesized that this nonlinear interaction is a result of the thermally induced stationary waves interacting with the local orography. The direct linear response to orography is found to be rather insignificant, however. Transient vorticity and heat fluxes also tend to play a negligible role in explaining the summer stationary wave patterns.Further decomposition of the linear model response to global diabatic heating indicates that the response to the Indian monsoon and the western Pacific heat source is of primary importance in determining the global stationary wave pattern. This large heat source not only determines the stationary flow features locally, but also remotely controls the flow structure over the whole Pacific, North America, and the Atlantic region. Thus, variabilities in the Indian monsoon and the western Pacific heating may exert a strong influence on the global climate variability.

  8. Late preterm: obstetric management.

    PubMed

    Meloni, Alessandra; Antonelli, Antonello; Deiana, Sara; Rocca, Alessio; Atzei, Alessandra; Paoletti, Anna Maria; Melis, Gian Benedetto

    2010-10-01

    Late preterm is the recommended definition for infants born at 34 0/7 to 36 6/7 weeks' gestation after the onset of the mother's last menstrual period. Late-preterm infants are known to have greater mortality and morbidity when compared with term infants during the neonatal period. Obstetric management plays a substantial role in influencing neonatal outcomes. We conducted a retrospective study on late-preterm births based on data collected by regional certificates of birth attendance, comparing overall data with those relative to our Department, the aim of our study was to evaluate if obstetric management, related to different delivery settings, could influence the prevalence and the method of delivery in late preterm gestational age. Preterm births represent about 10% of 25,011 births in Sardinia, and 72.6% of them are late preterm. Elective cesarean section results significantly higher in late preterm than in term deliveries. In our Department, both late-preterm delivery rate and elective cesarean sections rate were lower if compared with country region data. Obstetric management strategies play an important role in delaying deliveries and reducing late-preterm birth rates.

  9. Summer of Innovation Kick Off

    NASA Image and Video Library

    2010-06-09

    NASA Administrator Charles Bolden, left, and Jet Propulsion Laboratory Director Dr. Charles Elachi lead school students to High Bay One at JPL during the kick off of NASA's Summer of Innovation program at the Jet Propulsion Laboratory in Pasadena, Calif., Thursday, June 10, 2010. Through the program, NASA will engage thousands of middle school students and teachers in stimulating math and science-based education programs with the goal of increasing the number of future scientists, mathematicians, and engineers. Photo Credit: (NASA/Bill Ingalls)

  10. Summer of Innovation Kick Off

    NASA Image and Video Library

    2010-06-09

    NASA Administrator Charles Bolden, left, along with teachers and middle school students visit High Bay One in the Spacecraft Assembly Building as part of the kick off to NASA's Summer of Innovation program at the Jet Propulsion Laboratory in Pasadena, Calif., Thursday, June 10, 2010. Through the program, NASA will engage thousands of middle school students and teachers in stimulating math and science-based education programs with the goal of increasing the number of future scientists, mathematicians, and engineers. Photo Credit: (NASA/Bill Ingalls)

  11. Summer of Innovation Kick Off

    NASA Image and Video Library

    2010-06-09

    Jet Propulsion Laboratory Director Dr. Charles Elachi, center, and NASA Administrator Charles Bolden, right, lead school students to High Bay One at JPL during the kick off of NASA's Summer of Innovation program at the Jet Propulsion Laboratory in Pasadena, Calif., Thursday, June 10, 2010. Through the program, NASA will engage thousands of middle school students and teachers in stimulating math and science-based education programs with the goal of increasing the number of future scientists, mathematicians, and engineers. Photo Credit: (NASA/Bill Ingalls)

  12. Coupled resonator vertical cavity laser

    SciTech Connect

    Choquette, K.D.; Chow, W.W.; Hou, H.Q.; Geib, K.M.; Hammons, B.E.

    1998-01-01

    The monolithic integration of coupled resonators within a vertical cavity laser opens up new possibilities due to the unique ability to tailor the interaction between the cavities. The authors report the first electrically injected coupled resonator vertical-cavity laser diode and demonstrate novel characteristics arising from the cavity coupling, including methods for external modulation of the laser. A coupled mode theory is used model the output modulation of the coupled resonator vertical cavity laser.

  13. ON-LINE TOOLS FOR PROPER VERTICAL POSITIONING OF VERTICAL SAMPLING INTERVALS DURING SITE ASSESSMENT

    EPA Science Inventory

    This presentation presents on-line tools for proper vertical positioning of vertical sampling intervals during site assessment. Proper vertical sample interval selection is critical for generate data on the vertical distribution of contamination. Without vertical delineation, th...

  14. Inversions of vertical transfers between the Atlantic and Mediterranean waters by meteorological forcing in the Strait of Gibraltar

    NASA Astrophysics Data System (ADS)

    Sánchez-Román, Antonio; Jordà, Gabriel; Sannino, Gianmaria; Gomis, Damià

    2014-05-01

    The Strait of Gibraltar is the scenario of a very energetic baroclinic exchange between Atlantic and Mediterranean waters: fresh and warm Atlantic waters enter into the Mediterranean while salty and cold Mediterranean waters outflow to the Atlantic. Those water fluxes fluctuate at different timescales, the most important of which is the semidiurnal one. Other less important but non-negligible source of variability is the meteorological forcing that induces fluctuations in the range of few days of period and the seasonal and interannual variations. Moreover, the two-way exchange is influenced by vertical transfers of heat, salt and mass between the Mediterranean and Atlantic waters during their passage through the Strait. This fact modifies their TS properties having impact on the net heat and salt exchanges of the Mediterranean Sea with the global ocean. The aim of this work is to analyse the temporal variability of vertical transfers between the Atlantic and Mediterranean waters along their path through the Strait of Gibraltar, with emphasis on the reversal episodes of those vertical transports along the Strait. To do that we analyse the outputs of a numerical simulation covering the entire Mediterranean basin (1/6º of spatial resolution) with enhanced resolution in the area of the Strait (1/200º). Another special feature of this model is that it was only forced through the specification of both the atmospheric pressure and heat & water fluxes at the sea surface so, it does not include the forcing exerted by tides. Tides were excluded from the experiment to further investigate the effects of a realistic atmospheric forcing over the mean flow. The vertical fluxes between layers present enhanced fluctuations between late autumn and wintertime for all years investigated. On the contrary, minimum values are obtained in summer. This result is ascribed to the sensitivity of the horizontal exchange flows to the passage of atmospheric systems over the Mediterranean

  15. Vertical landing on an asteroid

    NASA Technical Reports Server (NTRS)

    Harel, D.; Geulman, M.

    1992-01-01

    This work is concerned with the final approach phase and vertical landing on an asteroid with a power-limited, electrically propelled spacecraft. With gravitational effects taken into account, a new solution to the fuel optimal vertical landing on an asteroid was obtained. In this solution, the spacecraft commanded acceleration is explicitly expressed as a function of vehicle velocity and time to go. Based on qualitative methods of analysis, the guidance strategy and the resulting trajectories were studied. It is shown that these fuel-optimal trajectories effectively assure a vertical soft landing on the asteroid. Results of numerical simulations for the vertical landing, starting from an elliptical orbit are presented.

  16. Vertical allometry: fact or fiction?

    PubMed

    Mahmood, Iftekhar; Boxenbaum, Harold

    2014-04-01

    In pharmacokinetics, vertical allometry is referred to the clearance of a drug when the predicted human clearance is substantially higher than the observed human clearance. Vertical allometry was initially reported for diazepam based on a 33-fold higher human predicted clearance than the observed human clearance. In recent years, it has been found that many other drugs besides diazepam, can be classified as drugs which exhibit vertical allometry. Over the years, many questions regarding vertical allometry have been raised. For example, (1) How to define and identify the vertical allometry? (2) How much difference should be between predicted and observed human clearance values before a drug could be declared 'a drug which follows vertical allometry'? (3) If somehow one can identify vertical allometry from animal data, how this information can be used for reasonably accurate prediction of clearance in humans? This report attempts to answer the aforementioned questions. The concept of vertical allometry at this time remains complex and obscure but with more extensive works one can have better understanding of 'vertical allometry'. Published by Elsevier Inc.

  17. 4. VIEW OF VERTICAL BORING MACHINE. (Bullard) Vertical turning lathe ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. VIEW OF VERTICAL BORING MACHINE. (Bullard) Vertical turning lathe (VTL). Machining the fixture for GE Turboshroud. G.S. O'Brien, operator. - Juniata Shops, Machine Shop No. 1, East of Fourth Avenue at Third Street, Altoona, Blair County, PA

  18. Doppler-shifting effects on frequency spectra of gravity waves observed near the summer mesopause at high latitude

    NASA Technical Reports Server (NTRS)

    Fritts, David C.; Wang, Ding-Yi

    1991-01-01

    Results are presented of radar observations of horizontal and vertical velocities near the summer mesopause at Poker Flat (Alaska), showing that the observed vertical velocity spectra were influenced strongly by Doppler-shifting effects. The horizontal velocity spectra, however, were relatively insensitive to horizontal wind speed. The observed spectra are compared with predicted spectra for various models of the intrinsic motion spectrum and degrees of Doppler shifting.

  19. Summer faculty fellowship program, 1984

    NASA Technical Reports Server (NTRS)

    Spencer, J. H. (Compiler)

    1984-01-01

    Since 1964, the National Aeronautics and Space Administration (NASA) has supported a program of summer faculty fellowships for engineering and science educators. In a series of collaborations between NASA research and development centers and nearby universities, engineering faculty members spend 10 or 11 weeks working with professional peers on research. The Summer Faculty Program Committee of the American Society of Engineering Education supervises the programs. Objectives: (1) to further the professional knowledge of a qualified between participants and NASA; (3) to enrich and refresh the research and teaching activities of participants institutions; and (4) to contribute to the research objectives of the NASA center. Program Description: College or university faculty members will be appointed as research fellows to spend 10 weeks in cooperative research and study at the NASA-Langley Research Center. The fellow will devote approximately 90 percent of the time to a research problem and the remaining time to a study program. The study program will consist of lectures and seminars on topics of general interest or that are directly relevant to the fellow's research project. The lecturers and seminar leaders will be distinguished scientists and engineers from NASA, education, or industry.

  20. Convective cloud top vertical velocity estimated from geostationary satellite rapid-scan measurements

    NASA Astrophysics Data System (ADS)

    Hamada, Atsushi; Takayabu, Yukari N.

    2016-05-01

    We demonstrate that the rate of development of cumulus clouds, as inferred from the so-called geostationary satellite "rapid-scan" measurements, is a good proxy for convective cloud top vertical velocity related to deep convective clouds. Convective cloud top vertical velocity is estimated from the decreasing rate of infrared brightness temperature observed by the Multi-functional Transport SATellite-1R (MTSAT-1R) over the ocean south of Japan during boreal summer. The frequency distribution of the estimated convective cloud top vertical velocity at each height is shown to distribute lognormally, and it is consistent with the statistical characteristics of direct measurements acquired in previous studies.

  1. Vertical 2D Heterostructures

    NASA Astrophysics Data System (ADS)

    Lotsch, Bettina V.

    2015-07-01

    Graphene's legacy has become an integral part of today's condensed matter science and has equipped a whole generation of scientists with an armory of concepts and techniques that open up new perspectives for the postgraphene area. In particular, the judicious combination of 2D building blocks into vertical heterostructures has recently been identified as a promising route to rationally engineer complex multilayer systems and artificial solids with intriguing properties. The present review highlights recent developments in the rapidly emerging field of 2D nanoarchitectonics from a materials chemistry perspective, with a focus on the types of heterostructures available, their assembly strategies, and their emerging properties. This overview is intended to bridge the gap between two major—yet largely disjunct—developments in 2D heterostructures, which are firmly rooted in solid-state chemistry or physics. Although the underlying types of heterostructures differ with respect to their dimensions, layer alignment, and interfacial quality, there is common ground, and future synergies between the various assembly strategies are to be expected.

  2. Vertically reciprocating auger

    NASA Technical Reports Server (NTRS)

    Etheridge, Mark; Morgan, Scott; Fain, Robert; Pearson, Jonathan; Weldi, Kevin; Woodrough, Stephen B., Jr.

    1988-01-01

    The mathematical model and test results developed for the Vertically Reciprocating Auger (VRA) are summarized. The VRA is a device capable of transporting cuttings that result from below surface drilling. It was developed chiefly for the lunar surface, where conventional fluid flushing while drilling would not be practical. The VRA uses only reciprocating motion and transports material through reflections with the surface above. Particles are reflected forward and land ahead of radially placed fences, which prevent the particles from rolling back down the auger. Three input wave forms are considered to drive the auger. A modified sawtooth wave form was chosen for testing, over a modified square wave or sine wave, due to its simplicity and effectiveness. The three-dimensional mathematical model predicted a sand throughput rate of 0.2667 pounds/stroke, while the actual test setup transported 0.075 pounds/stroke. Based on this result, a correction factor of 0.281 is suggested for a modified sawtooth input.

  3. Kinematic and diabatic vertical velocity climatologies from a chemistry climate model

    NASA Astrophysics Data System (ADS)

    Marinke Hoppe, Charlotte; Ploeger, Felix; Konopka, Paul; Müller, Rolf

    2016-05-01

    The representation of vertical velocity in chemistry climate models is a key element for the representation of the large-scale Brewer-Dobson circulation in the stratosphere. Here, we diagnose and compare the kinematic and diabatic vertical velocities in the ECHAM/Modular Earth Submodel System (MESSy) Atmospheric Chemistry (EMAC) model. The calculation of kinematic vertical velocity is based on the continuity equation, whereas diabatic vertical velocity is computed using diabatic heating rates. Annual and monthly zonal mean climatologies of vertical velocity from a 10-year simulation are provided for both kinematic and diabatic vertical velocity representations. In general, both vertical velocity patterns show the main features of the stratospheric circulation, namely, upwelling at low latitudes and downwelling at high latitudes. The main difference in the vertical velocity pattern is a more uniform structure for diabatic and a noisier structure for kinematic vertical velocity. Diabatic vertical velocities show higher absolute values both in the upwelling branch in the inner tropics and in the downwelling regions in the polar vortices. Further, there is a latitudinal shift of the tropical upwelling branch in boreal summer between the two vertical velocity representations with the tropical upwelling region in the diabatic representation shifted southward compared to the kinematic case. Furthermore, we present mean age of air climatologies from two transport schemes in EMAC using these different vertical velocities and analyze the impact of residual circulation and mixing processes on the age of air. The age of air distributions show a hemispheric difference pattern in the stratosphere with younger air in the Southern Hemisphere and older air in the Northern Hemisphere using the transport scheme with diabatic vertical velocities. Further, the age of air climatology from the transport scheme using diabatic vertical velocities shows a younger mean age of air in the

  4. Kinematic and diabatic vertical velocity climatologies from a chemistry climate model

    NASA Astrophysics Data System (ADS)

    Hoppe, C. M.; Ploeger, F.; Konopka, P.; Müller, R.

    2015-11-01

    The representation of vertical velocity in chemistry climate models is a key element for the representation of the large scale Brewer-Dobson-Circulation in the stratosphere. Here, we diagnose and compare the kinematic and diabatic vertical velocities in the ECHAM/Messy Atmospheric Chemistry (EMAC) model. The calculation of kinematic vertical velocity is based on the continuity equation, whereas diabatic vertical velocity is computed using diabatic heating rates. Annual and monthly zonal mean climatologies of vertical velocity from a 10 year simulation are provided for both, kinematic and diabatic vertical velocity representations. In general, both vertical velocity patterns show the main features of the stratospheric circulation, namely upwelling at low latitudes and downwelling at high latitudes. The main difference in the vertical velocity pattern is a more uniform structure for diabatic and a noisier structure for kinematic vertical velocity. Diabatic vertical velocities show higher absolute values both in the upwelling branch in the inner tropics and in the downwelling regions in the polar vortices. Further, there is a latitudinal shift of the tropical upwelling branch in boreal summer between the two vertical velocity representations with the tropical upwelling region in the diabatic representation shifted southward compared to the kinematic case. Furthermore, we present mean age of air climatologies from two transport schemes in EMAC using these different vertical velocities. The age of air distributions show a hemispheric difference pattern in the stratosphere with younger air in the Southern Hemisphere and older air in the Northern Hemisphere using the transport scheme with diabatic vertical velocities. Further, the age of air climatology from the transport scheme using diabatic vertical velocities shows younger mean age of air in the inner tropical upwelling branch and older mean age in the extratopical tropopause region.

  5. The School Library Vertical File.

    ERIC Educational Resources Information Center

    Smallwood, Carol

    1990-01-01

    Discusses the maintenance of vertical files in the school library. Topics covered include circulation, weeding, using materials for special displays, acquiring materials, policies on advertising and controversial issues, cross-references, subject headings, introducing students to vertical files, beginning a collection, and preservation. (MES)

  6. Latitude and longitude vertical disparity

    PubMed Central

    Read, Jenny C. A.; Phillipson, Graeme P.; Glennerster, Andrew

    2010-01-01

    The literature on vertical disparity is complicated by the fact that several different definitions of the term “vertical disparity” are in common use, often without a clear statement about which is intended or a widespread appreciation of the properties of the different definitions. Here, we examine two definitions of retinal vertical disparity: elevation-latitude and elevation-longitude disparity. Near the fixation point, these definitions become equivalent, but in general, they have quite different dependences on object distance and binocular eye posture, which have not previously been spelt out. We present analytical approximations for each type of vertical disparity, valid for more general conditions than previous derivations in the literature: we do not restrict ourselves to objects near the fixation point or near the plane of regard, and we allow for non-zero torsion, cyclovergence and vertical misalignments of the eyes. We use these expressions to derive estimates of the latitude and longitude vertical disparity expected at each point in the visual field, averaged over all natural viewing. Finally, we present analytical expressions showing how binocular eye position – gaze direction, convergence, torsion, cyclovergence, and vertical misalignment – can be derived from the vertical disparity field and its derivatives at the fovea. PMID:20055544

  7. Measuring Growth with Vertical Scales

    ERIC Educational Resources Information Center

    Briggs, Derek C.

    2013-01-01

    A vertical score scale is needed to measure growth across multiple tests in terms of absolute changes in magnitude. Since the warrant for subsequent growth interpretations depends upon the assumption that the scale has interval properties, the validation of a vertical scale would seem to require methods for distinguishing interval scales from…

  8. Measuring Growth with Vertical Scales

    ERIC Educational Resources Information Center

    Briggs, Derek C.

    2013-01-01

    A vertical score scale is needed to measure growth across multiple tests in terms of absolute changes in magnitude. Since the warrant for subsequent growth interpretations depends upon the assumption that the scale has interval properties, the validation of a vertical scale would seem to require methods for distinguishing interval scales from…

  9. The Gains from Vertical Scaling

    ERIC Educational Resources Information Center

    Briggs, Derek C.; Domingue, Ben

    2013-01-01

    It is often assumed that a vertical scale is necessary when value-added models depend upon the gain scores of students across two or more points in time. This article examines the conditions under which the scale transformations associated with the vertical scaling process would be expected to have a significant impact on normative interpretations…

  10. Vertical Movements On The Norwegian Atlantic Margin

    NASA Astrophysics Data System (ADS)

    Hendriks, B. W. H.; Andriessen, P. A. M.

    In order to better constrain the pattern and timing of the post-Caledonian vertical movements in northern Scandinavia, the apatite fission track dataset of Hendriks and Andriessen (2002, in press) has recently been expanded with additional AFT data and a whole new set of (U-Th)/He data. Hendriks and Andriessen (2002) found an increase of AFT ages from the Norwegian Atlantic margin (mostly Cretaceous AFT ages) to the continental interior (Devonian AFT ages). Further north, along the Barents Sea margin, AFT ages were much less variable (Triassic - Carboniferous). Because of the unique low -temperature sensitivity of the (U-Th)/He technique, with ages referrering to temperatures of ~50 to ~70°C, we can now track thermal histories in northern Scandinavia into the Paleocene. The reconstuct ed denudation history in many ways is different from that of Southern Norway (Rohrman, 1995). There, rapid Triassic - Jurassic and slow Cretaceous - Paleogene exhumation were followed by domal style postrift uplift on a regional scale in the Neogene. In contrast, Mesozoic - Cenozoic exhumation of northern Scandinavia was strongly assymetric, with the most and latest denudation on the Norwegian Atlantic margin. Also, large Neogene vertical movements here are restricted to the area of the strong negative gravity anomaly in Nordland. Away from this area, the latest phase of exhumation is a late Cretaceous- Paleogene event. This is especially clear from the (U -Th)/He ages, varying between 111 +/- 16 Ma (for the same sample the AFT age is 220 +/- 25 Ma, mean track length 12.9 µm) and 57 +/- 2 Ma (AFT age 254 +/- 21 Ma, mean track length 13.9 µm) on a vertical profile in the area of maximum elevation in the Northern Scandes (~ Northern Caledonides). Jurassic - early Cretaceous denudation (applying a geotherm of ~ 30°C/km, which has been calculated directly from the vertical profile) is about 1 +/- 0.5 km. Along the Norwegian Atlantic margin (onshore), there is considerable variation in

  11. The Summer Monsoon of 1987.

    NASA Astrophysics Data System (ADS)

    Krishnamurti, T. N.; Bedi, H. S.; Subramaniam, M.

    1989-04-01

    In this paper we have examined the evolution of a number of parameters we believe were important for our understanding of the drought over India during the summer of 1987. The list of parameters includes monthly means or anomalies of the following fields: sea surface temperatures, divergent circulations, outgoing longwave radiation, streamfunction of the lower and upper troposphere, and monthly precipitation (expressed as a percentage departure from a long-term mean). The El Niño related warm sea surface temperature anomaly and a weaker warm sea surface temperature anomaly over the equatorial Indian Ocean provide sustained convection, as reflected by the negative values of the outgoing longwave radiation. With the seasonal heating, a pronounced planetary-scale divergent circulation evolved with a center along the western Pacific Ocean. The monsoonal divergent circulation merged with that related to the El Niño, maintaining most of the heavy rainfall activity between the equatorial Pacific Ocean and east Asia. Persistent convective activity continued south of India during the entire monsoon season. Strong Hadley type overturnings with rising motions over these warm SST anomaly regions and descent roughly near 20° to 25°S was evident as early as April 1987. The subtropical high pressure areas near 20° to 25°S showed stronger than normal circulations. This was revealed by the presence of a counterclockwise streamfunction anomaly at 850 mb during April 1987. With the seasonal heating, this anomaly moved northwards and was located over the Arabian Sea and India. This countermonsoon circulation anomaly at the low levels was associated with a weaker than normal Somali jet and Arabian Sea circulation throughout this summer. The monsoon remained active along northeast India, Bangladesh, northern lndochina, and central China during the summer monsoon season. This was related to the eastward shift of the divergent circulation. An eastward shift of the upper tropospheric

  12. Classification of typical summer rainfall patterns in the East China monsoon region and their association with the East Asian summer monsoon

    NASA Astrophysics Data System (ADS)

    Yang, Liu; Zhao, Junhu; Feng, Guolin

    2017-08-01

    In this study, the summer rainfall patterns in the East China monsoon region during 1951-2015 were objectively classified into four typical categories: the northern China rainfall pattern (NCP), the intermediate rainfall pattern (IRP), the Yangtze River rainfall pattern (YRP), and the South China rainfall pattern (SCP). The periods of the four patterns show significant decadal characteristics. The NCP occurred mainly between the late 1950s and the early 1980s, and the IRP in the late 1950s to the early 1970s and the 2000s. The YRP occurred mainly between the 1980s and the 1990s, and the SCP between the mid-1990s and the early 21st century. The relationship between the East Asian summer monsoon index (EASM I WF) and the four rainfall patterns was comparatively analyzed. The results confirmed that the four rainfall patterns have obvious differences in the EASM. In the NCP, IRP, or SCP years, the EASM I WF primarily showed a positive phase and a strong summer monsoon; in the YRP years, the EASM I WF primarily showed a negative phase and a weak summer monsoon.

  13. Classification of typical summer rainfall patterns in the East China monsoon region and their association with the East Asian summer monsoon

    NASA Astrophysics Data System (ADS)

    Yang, Liu; Zhao, Junhu; Feng, Guolin

    2016-06-01

    In this study, the summer rainfall patterns in the East China monsoon region during 1951-2015 were objectively classified into four typical categories: the northern China rainfall pattern (NCP), the intermediate rainfall pattern (IRP), the Yangtze River rainfall pattern (YRP), and the South China rainfall pattern (SCP). The periods of the four patterns show significant decadal characteristics. The NCP occurred mainly between the late 1950s and the early 1980s, and the IRP in the late 1950s to the early 1970s and the 2000s. The YRP occurred mainly between the 1980s and the 1990s, and the SCP between the mid-1990s and the early 21st century. The relationship between the East Asian summer monsoon index (EASM I WF) and the four rainfall patterns was comparatively analyzed. The results confirmed that the four rainfall patterns have obvious differences in the EASM. In the NCP, IRP, or SCP years, the EASM I WF primarily showed a positive phase and a strong summer monsoon; in the YRP years, the EASM I WF primarily showed a negative phase and a weak summer monsoon.

  14. Suicides in late life.

    PubMed

    Van Orden, Kimberly; Conwell, Yeates

    2011-06-01

    Suicide in late life is an enormous public health problem that will likely increase in severity as adults of the baby boom generation age. Data from psychological autopsy studies supplemented with recent studies of suicidal ideation and attempts point to a consistent set of risk factors for the spectrum of suicidal behaviors in late life (suicide ideation, attempts, and deaths). Clinicians should be vigilant for psychiatric illness (especially depression), physical illness, pain, functional impairment, and social disconnectedness. Recent advances in late-life suicide prevention have in common collaborative, multifaceted intervention designs. We suggest that one mechanism shared by all preventive interventions shown to reduce the incidence of late-life suicide is the promotion of connectedness. For the clinician working with older adults, our recommendation is to not only consider risk factors, such as depression, and implement appropriate treatments but to enhance social connectedness as well.

  15. Suicides in Late Life

    PubMed Central

    Van Orden, Kimberly; Conwell, Yeates

    2011-01-01

    Suicide in late life is an enormous public health problem that will likely increase in severity as adults of the baby boom generation age. Data from psychological autopsy studies supplemented with recent studies of suicidal ideation and attempts point to a consistent set of risk factors for the spectrum of suicidal behaviors in late life (suicide ideation, attempts, and deaths). Clinicians should be vigilant for psychiatric illness (especially depression), physical illness, pain, functional impairment, and social disconnectedness. Recent advances in late-life suicide prevention have in common collaborative, multifaceted intervention designs. We suggest that one mechanism shared by all preventive interventions shown to reduce the incidence of late-life suicide is the promotion of connectedness. For the clinician working with older adults, our recommendation is to not only consider risk factors, such as depression, and implement appropriate treatments but to enhance social connectedness as well. PMID:21369952

  16. HAARP 2011 Summer Student Research Campaign

    DTIC Science & Technology

    2012-10-16

    AFRL-RV-PS- AFRL-RV-PS- TR-2012-0152 TR-2012-0152 HAARP 2011 SUMMER STUDENT RESEARCH CAMPAIGN Edward J. Kennedy, et al...COVERED (From - To) 18 Jul 2008 – 25 Jul 2012 4. TITLE AND SUBTITLE HAARP 2011 SUMMER STUDENT RESEARCH CAMPAIGN 5a. CONTRACT NUMBER FA8718-08-C...Summer Student Research Campaign (SSRC) was conducted at the High Frequency Active Auroral Research Program ( HAARP ) Research Station in Gakona

  17. The Onset of Early Season Rainfall and its Mid-Summer Cessation in the Caribbean.

    NASA Astrophysics Data System (ADS)

    Allen, T. L.; Mapes, B. E.

    2014-12-01

    The annual rainfall cycle for the Caribbean basin reveals a distinct bimodal pattern with peaks during the late spring and late summer months. A relative minimum during the mid-summer, known as the mid-summer drought (MSD) separates the early rainfall season (ERS) from the late rainfall season. Accumulated rainfall totals during the ERS appear as a quasi-stationary rain-belt stretching across the Caribbean from the southwest to the northeast. We place late spring rains in the Caribbean in context of other subtropical convergence zones in order to address the onset and cessation of the ERS while also offering an explanation of a Caribbean rain-belt pattern. Upper tropospheric westerlies, mid-tropospheric positive temperature advection, and moist low level poleward flow are the three primary ingredients that conspire to produce the first peak of the annual bimodal rain signal and the related Caribbean early season rain-belt. The MSD ensues as the primary ingredients weaken across the Caribbean and enhanced rainfall shifts north along the North Atlantic Convergence Zone (NACZ). Seasonal rainfall totals from the ERS through the MSD periods reveal a continuous rain-belt that extends from the Caribbean to the NACZ termed the Caribbean Atlantic Rain-belt (CAR-belt). The Car-belt is present in the long term mean, but has signs of interannual variability.

  18. Characterizing Late Quaternary Paleochannel System Evolution on the East Texas Continental Shelf

    NASA Astrophysics Data System (ADS)

    Speed, C.; Gulick, S. P. S.; Goff, J.; Swartz, J. M.; Fernandez, R.

    2016-12-01

    The northern Gulf of Mexico continental shelf plays host to a variety of buried incised valley and paleochannel systems. The formation of these incisional features is due in part to Quaternary eustatic sea level oscillations, thought largely to represent fluctuations in global ice volume. However, a complex interplay exists between the role of climate, eustasy, and autogenic sedimentary processes in the formation and evolution of paleochannel systems throughout geologic time. These elaborate channel networks act not only as a conduit for sediment transport to the outer shelf and deep sea, but also as a location for sediment storage during subsequent transgressions. Understanding the timing of incision and the internal sedimentary architecture of buried channel systems provides insight into the formational processes of the paleochannel system and the role it played in sediment transport and storage. Over 300 kilometers of ultra-high-resolution (0.5-12 kHz) CHIRP sub-bottom profile and high-resolution (40-450 Hz) two-dimensional multichannel seismic (MCS) data were collected on the inner continental shelf south of Freeport, TX during the 2015 and 2016 University of Texas Institute for Geophysics Marine Geology and Geophysics summer field course(s). The survey focused on imaging the Late Quaternary formation and evolution of the incised valley and channel system associated with the paleo-Brazos River. CHIRP data provide decimeter-scale vertical resolution imaging the upper 15-50 meters of the subsurface, while high-resolution MCS data provide vertical resolution of 1-3 meters and penetration on the order of hundreds of meters. These complementary datasets allow for an integrated stratigraphic analysis of multiple generations of Pleistocene to Holocene-aged paleochannels and key comparisons of various channel-forming processes, sediment transport mechanisms, and storage potential on the northern Gulf of Mexico continental shelf.

  19. Nile behaviour and Late Palaeolithic humans in Upper Egypt during the Late Pleistocene

    NASA Astrophysics Data System (ADS)

    Vermeersch, Pierre M.; Van Neer, Wim

    2015-12-01

    , even in late summer.

  20. Estimates of the seasonal mean vertical velocity fields of the extratropical Northern Hemisphere

    NASA Technical Reports Server (NTRS)

    White, G. H.

    1983-01-01

    Indirect methods are employed to estimate the wintertime and summertime mean vertical velocity fields of the extratropical Northern Hemisphere and intercomparisons are made, together with comparisons with mean seasonal patterns of cloudiness and precipitation. Twice-daily NMC operational analyses produced general circulation statistics for 11 winters and 12 summers, permitting calculation of the seasonal NMC averages for 6 hr forecasts, solution of the omega equation, integration of continuity equation downward from 100 mb, and solution of the thermodynamic energy equation in the absence of diabatic heating. The methods all yielded similar vertical velocity patterns; however, the magnitude of the vertical velocities could not be calculated with great accuracy. Orography was concluded to have less of an effect in summer than in winter, when winds are stronger.

  1. Methyl chloride in the UT/LS observed by CARIBIC: global distribution, Asian summer monsoon outflow, and use as a tracer for tropical air

    NASA Astrophysics Data System (ADS)

    Baker, A. K.; Umezawa, T.; Oram, D.; Sauvage, C.; Rauthe-Schoech, A.; Montzka, S. A.; Zahn, A.; Brenninkmeijer, C. A. M.

    2014-12-01

    We present spatiotemporal variations of methyl chloride (CH3Cl) in the UT/LS observed mainly by the CARIBIC passenger aircraft for the years 2005-2011. The CH3Cl mixing ratio in the UT over Europe was higher than that observed at a European surface baseline station year-round, indicative of a persistent positive vertical gradient at NH mid latitudes. A series of flights over Africa and South Asia show that CH3Cl mixing ratios increase toward tropical latitudes, and the observed UT CH3Cl level over these two regions and the Atlantic was higher than that measured at remote surface sites. Strong emissions of CH3Cl in the tropics combined with meridional transport through the UT may explain such vertical and latitudinal gradients. Comparisons with CO data indicate that non-combustion sources in the tropics dominantly contribute to forming the latitudinal gradient of CH3Cl in the UT. We also observed elevated CH3Cl and CO in air influenced by biomass burning in South America and Africa, and the enhancement ratios derived for CH3Cl to CO in those regions agree with previous observations. In contrast, correlations indicate a high CH3Cl to CO ratio of 2.9±0.5 ppt ppb-1 in the Asian summer monsoon anticyclone and domestic biofuel emissions in South Asia are inferred to be responsible. We estimated CH3Cl emissions from South Asia to be 134±23 Gg Cl yr-1, which is higher than a previous estimate due to the higher CH3Cl to CO ratio observed in this study. We also examine the use of CH3Cl as a tracer of tropical tropospheric air in the LMS, where we identified air masses with elevated CH3Cl that were however stratospheric in terms of N2O. Back trajectories suggest recent low-latitude origins of such air masses in early summer. In this season, high CH3Cl LMS air shows a clear branch connecting stratospheric and tropical tropospheric air on N2O-CH3Cl scatterplots. This distinct feature vanishes in late summer when the LMS is ventilated by tropospheric air.

  2. Vertical bloch line memory

    NASA Technical Reports Server (NTRS)

    Katti, R.; Wu, J.; Stadler, H.

    1990-01-01

    Vertical Bloch Line (VBL) memory is a recently conceived, integrated, solid-state, block-access, VLSI memory which offers the potential of 1Gbit/sq cm real storage density, gigabit per second data rates, and sub-millisecond average access times simultaneously at relatively low mass, volume, and power values when compared to alternative technologies. VBL's are micromagnetic structures within magnetic domain walls which can be manipulated using magnetic fields from integrated conductors. The presence or absence of VBL pairs are used to store binary information. At present, efforts are being directed at developing a single-chip memory using 25Mbit/sq cm technology in magnetic garnet material which integrates, at a single operating point, the writing, storage, reading, and amplification functions needed in a memory. This paper describes the current design architecture, functional elements, and supercomputer simulation results which are used to assist the design process. The current design architecture uses three metal layers, two ion implantation steps for modulating the thickness of the magnetic layer, one ion implantation step for assisting propagation in the major line track, one NiFe soft magnetic layer, one CoPt hard magnetic layer, and one reflective Cr layer for facilitating magneto-optic observation of magnetic structure. Data are stored in a series of elongated magnetic domains, called stripes, which serve as storage sites for arrays of VBL pairs. The ends of these stripes are placed near conductors which serve as VBL read/write gates. A major line track is present to provide a source and propagation path for magnetic bubbles. Writing and reading, respectively, are achieved by converting magnetic bubbles to VBL's and vice versa. The output function is effected by stretching a magnetic bubble and detecting it magnetoresistively. Experimental results from the past design cycle created four design goals for the current design cycle. First, the bias field ranges

  3. A quantitative study of the summer slide in science of elementary school students

    NASA Astrophysics Data System (ADS)

    Donovan, Giovanna Guadagno

    Concerned parents and educators agree children learn best when the rhythm of instruction is continuous with practice and application of skills. Long summer breaks may interrupt the flow of formal school learning leading some students to forget previous instruction. A review of the previous school work is generally required in the fall upon return from the summer vacation. Investigating summer vacation and equity issues, Jamar (1994) noted that more affluent students may "return to school in the fall with a considerable educational advantage over their less advantaged peers as a result of either additional school-related learning, or lower levels of forgetting, over the summer months (p. 1)". The population of 402 fifth grade students from a suburban New England school district participated in this study. The district administered the science subtest of the TerraNova 2 (TN2) assessment in late May 2007 (pre-test data) and in September 2007 (post-test data). These archived data, including gender and student socioeconomic status (SES) levels (as referenced by free or reduced lunch status), were analyzed for an ex-post facto causal comparison study to identify the phenomenon of summer slide in science of fifth graders enrolled in six elementary schools. The ANOVA statistical model was used calculating the repeated measures factor of time (pre/post summer vacation) on the science content area. Subsequent two-way ANOVAS, with one repeated-measures factor (time of testing) explored the existence of similar/different patterns by gender and by SES levels. Two questions guided this study. First, does the summer slide phenomenon exist in science education? Second, if the summer slide in science phenomenon exists in science education, then does SES impact it? Does the summer slide in science phenomenon differ between genders? Findings suggest that the summer slide phenomenon exists in science; SES and gender does not affect the overall science test scores. However, SES impacts

  4. Summer temperatures across northern North America: Regional reconstructions from 1760 using tree-ring densities

    NASA Astrophysics Data System (ADS)

    Briffa, K. R.; Jones, P. D.; Schweingruber, F. H.

    1994-12-01

    Using maximum latewood density data from a network of coniferous trees, annually resolved series of average summer half-year (April-September) temperatures have been reconstructed for three regions of North America: Alaska and the Yukon (ALAYUK), the Mackenzie valley (MACKVA), and Quebec and Labrador (QUEBLA). The reconstructions primarily express temperature variability on interannual-to-decadal timescales and extend over the period from AD 1760. These reconstructions represent an extension of the mean climate history for these regions of over 100 years. The ALAYUK series shows relatively wann summers dominating the 1770s and 1820s. The 1760s, 1810s, 1860s, and 1890s were cold; 1810 was the coldest summer over the whole region, though it was very cold in 1783 in the extreme northwest. In MACKVA the 1780s and 1790s were warm, while the 1810s, 1830s, and late 1880s were cool. The summer of 1862 was exceptionally warm and 1836 was notably cold. In QUEBLA the 1800s, 1820s, and late 1890s were relatively warm, while the 1760s and 1810s were particularly cool. The summers of 1816 and 1817 were extremely cold. The dates of the extreme cold summers in each series emphasize the strong volcanic influence on extreme high-latitude temperatures. However, the reconstructions also highlight the large regional differences in the magnitude of this influence. The severity and spatial extent of severe conditions across western North America in the summer of 1810 supports earlier hypotheses of a major volcanic eruption in 1809 for which there is no historical evidence.

  5. The formation of multiple layers of ice particles in the polar summer mesopause region

    NASA Astrophysics Data System (ADS)

    Li, H.; Wu, J.; Zhou, Z.

    2016-01-01

    This paper presents a two-dimensional theoretical model to study the formation process of multiple layers of small ice particles in the polar summer mesosphere as measured by rockets and associated with polar mesosphere summer echoes (PMSE). The proposed mechanism primarily takes into account the transport processes induced by gravity waves through collision coupling between the neutral atmosphere and the ice particles. Numerical solutions of the model indicate that the dynamic influence of wind variation induced by gravity waves can make a significant contribution to the vertical and horizontal transport of ice particles and ultimately transform them into thin multiple layers. Additionally, the pattern of the multiple layers at least partially depends on the vertical wavelength of the gravity wave, the ice particle size and the wind velocity. The results presented in this paper will be helpful to better understand the occurrence of multiple layers of PMSE as well as its variation process.

  6. Late archaic settlement systems in the northern Rio Grande

    SciTech Connect

    Vierra, Bradley J.

    2003-01-01

    Last year at these meetings I proposed a possible seasonal transhumance pattern for the Late Archaic in the northern Rio Grande region. This pattern involved the movement of groups from the lowland juniper-savanna grasslands in the early summer, to the upland ponderosa pindmixed conifer forests in the mid to late summer, and then back down to the piiion-juniper woodlands during the fall. The Rio Grande Valley was also used for winter habitation sites. Following on this research, I take the next step by studying the inter-assemblage variability represented in a sample of open-air sites located within each of these vegetation communities. The results indicate that there are significant differences in reduction tactics represented between valley habitation vs., upland campsites, and that these site sites are linked together by obsidian procurement patterns.

  7. Diel vertical migration of phytoplankton and heterotrophic flagellates in the Gulf of Riga

    NASA Astrophysics Data System (ADS)

    Olli, Kalle

    1999-12-01

    Vertical distribution of a phototrophic ciliate ( Mesodinium rubrum), autotrophic dinoflagellates ( Peridiniella catenata, Heterocapsa rotundata, Dinophysis acuminata), a cryptomonad ( Teleaulax sp.), a filamentous cyanobacterium ( Aphanizomenon flos-aquae), a non-motile chlorophyte ( Monoraphidium sp.) and two heterotrophic dinoflagellates were studied during two diel periods in spring (May 1-2 and 27-28, 1995) and summer (June 26-27 and July 6-7, 1994) in the southern part of the Gulf of Riga, the Baltic Sea. The two seasons, corresponding to the vernal bloom and summer stage, differed considerably with respect to phytoplankton community, hydrography and vertical distribution of the species. In spring the cells stayed in the upper mixed layer above a strong thermocline at 12-15 m depth, and changes in the vertical distribution were related to surface avoidance in the middle of the day. By using correspondence analysis, the vertical distribution of all the motile species were shown to differ significantly from the non-motile Monoraphidium, but not from each other. The vertical migration was reflected in a higher variability in the depth distribution patterns of the motile species, compared to Monoraphidium. In summer 1994, Aphanizomenon, Dinophysis and Teleaulax showed similar depth distribution patterns during the first period, but different from Mesodinium and the heterotrophic dinoflagellates, while during the second period all the autotrophic species had a species specific depth distribution pattern. Me. rubrum revealed a considerably different depth distribution between the two seasons, characterised by surface accumulation in spring and relatively uniform depth distribution over the whole sampling range (0-30 m) in summer. The results demonstrate different vertical niche separation strategies between species.

  8. Summertime, Summer Teens: Summer School Enrollment and the Youth Labor Force.

    ERIC Educational Resources Information Center

    Stringer, Tiffany

    2003-01-01

    Describes changes in how teenagers spend their summers and at the trends in summer school enrollment. Discusses teens' labor force participation and includes information about types of jobs, hours they work, wages, and teenage workers' rights. (JOW)

  9. Influences of castration and testosterone on spring to summer changes in release of luteinizing-hormone-releasing hormone in rabbits.

    PubMed

    Lin, W W; Ramirez, V D

    1992-09-01

    Push-pull cannulae were implanted toward the tuberal region of the hypothalamus in ten intact New Zealand male rabbits. In the first experiment, rabbits were perfused at different times after castration: 5-10 days (n = 10), 22-31 days (n = 9) and 50-64 days (n = 8). The release, mean amplitude and mean frequency of luteinizing-hormone-releasing hormone (LHRH) signals from 37 perfusions in ten animals were analysed in intact rabbits and at different times after castration. No significant changes in release of LHRH and in amplitude were observed, but the frequency was significantly higher 22-31 days after castration than in intact rabbits (intact: 0.86 +/- 0.12; castrated: 1.20 +/- 0.13 pulses h-1, P < 0.035; n = 9). In Expt 2, testosterone and placebo Silastic capsules were implanted in the castrated rabbits. Perfusions were performed in the following four periods, defined by season and time after testosterone and placebo implants: (i) spring; before implants, (ii) late spring; 0-2 weeks after implants, (iii) summer solstice; 2-4 weeks after implants and (iv) summer; 4-6 weeks after implants. Castrated rabbits were perfused during spring; castrated rabbits with testosterone capsule implants were perfused during late spring, around summer solstice and in summer and castrated rabbits with placebo implants were perfused during periods (iii) and (iv). Castrated animals with placebo implants showed no significant changes in mean LHRH release and amplitude, although the frequency was significantly higher around the summer solstice period than in castrated rabbits perfused in the spring. In castrated rabbits with testosterone implants LHRH release was significantly higher in late spring than around the summer solstice and in the summer. In addition, the concentrations of LHRH in late spring were significantly higher than those of intact and castrated animals. In contrast, mean LHRH amplitude and frequency did not change. Mean amount of LHRH released and amplitude in

  10. Watching Summer Clouds on Titan

    NASA Image and Video Library

    2016-11-04

    NASA's Cassini spacecraft watched clouds of methane moving across the far northern regions of Saturn's largest moon, Titan, on Oct. 29 and 30, 2016. Several sets of clouds develop, move over the surface and fade during the course of this movie sequence, which spans 11 hours, with one frame taken every 20 minutes. Most prominent are long cloud streaks that lie between 49 and 55 degrees north latitude. While the general region of cloud activity is persistent over the course of the observation, individual streaks appear to develop then fade. These clouds are measured to move at a speed of about 14 to 22 miles per hour (7 to 10 meters per second). There are also some small clouds over the region of small lakes farther north, including a bright cloud between Neagh Lacus and Punga Mare, which fade over the course of the movie. This small grouping of clouds is moving at a speed of about 0.7 to 1.4 miles per hour (1 to 2 meters per second). Time-lapse movies like this allow scientists to observe the dynamics of clouds as they develop, move over the surface and fade. A time-lapse movie can also help to distinguish between noise in images (for example from cosmic rays hitting the detector) and faint clouds or fog. In 2016, Cassini has intermittently observed clouds across the northern mid-latitudes of Titan, as well as within the north polar region -- an area known to contain numerous methane/ethane lakes and seas see PIA19657 and PIA17655. However, most of this year's observations designed for cloud monitoring have been short snapshots taken days, or weeks, apart. This observation provides Cassini's best opportunity in 2016 to study short-term cloud dynamics. Models of Titan's climate have predicted more cloud activity during early northern summer than what Cassini has observed so far, suggesting that the current understanding of the giant moon's changing seasons is incomplete. The mission will continue monitoring Titan's weather around the 2017 summer solstice in Titan

  11. Vertical axis wind turbine airfoil

    DOEpatents

    Krivcov, Vladimir; Krivospitski, Vladimir; Maksimov, Vasili; Halstead, Richard; Grahov, Jurij Vasiljevich

    2012-12-18

    A vertical axis wind turbine airfoil is described. The wind turbine airfoil can include a leading edge, a trailing edge, an upper curved surface, a lower curved surface, and a centerline running between the upper surface and the lower surface and from the leading edge to the trailing edge. The airfoil can be configured so that the distance between the centerline and the upper surface is the same as the distance between the centerline and the lower surface at all points along the length of the airfoil. A plurality of such airfoils can be included in a vertical axis wind turbine. These airfoils can be vertically disposed and can rotate about a vertical axis.

  12. Vertically scanned laser sheet microscopy.

    PubMed

    Dong, Di; Arranz, Alicia; Zhu, Shouping; Yang, Yujie; Shi, Liangliang; Wang, Jun; Shen, Chen; Tian, Jie; Ripoll, Jorge

    2014-01-01

    Laser sheet microscopy is a widely used imaging technique for imaging the three-dimensional distribution of a fluorescence signal in fixed tissue or small organisms. In laser sheet microscopy, the stripe artifacts caused by high absorption or high scattering structures are very common, greatly affecting image quality. To solve this problem, we report here a two-step procedure which consists of continuously acquiring laser sheet images while vertically displacing the sample, and then using the variational stationary noise remover (VSNR) method to further reduce the remaining stripes. Images from a cleared murine colon acquired with a vertical scan are compared with common stitching procedures demonstrating that vertically scanned light sheet microscopy greatly improves the performance of current light sheet microscopy approaches without the need for complex changes to the imaging setup and allows imaging of elongated samples, extending the field of view in the vertical direction.

  13. Vertical Beam Polarization at MAMI

    NASA Astrophysics Data System (ADS)

    Schlimme, B. S.; Achenbach, P.; Aulenbacher, K.; Baunack, S.; Bender, D.; Beričič, J.; Bosnar, D.; Correa, L.; Dehn, M.; Distler, M. O.; Esser, A.; Fonvieille, H.; Friščić, I.; Gutheil, B.; Herrmann, P.; Hoek, M.; Kegel, S.; Kohl, Y.; Kolar, T.; Kreidel, H.-J.; Maas, F.; Merkel, H.; Mihovilovič, M.; Müller, J.; Müller, U.; Nillius, F.; Nuck, A.; Pochodzalla, J.; Schoth, M.; Schulz, F.; Sfienti, C.; Širca, S.; Spruck, B.; Štajner, S.; Thiel, M.; Tioukine, V.; Tyukin, A.; Weber, A.

    2017-04-01

    For the first time a vertically polarized electron beam has been used for physics experiments at MAMI in the energy range between 180 and 855 MeV. The beam-normal single-spin asymmetry An, which is a direct probe of higher-order photon exchange beyond the first Born approximation, has been measured in the reaction 12C (e → , e ‧)12C . Vertical polarization orientation was necessary to measure this asymmetry with the existing experimental setup. In this paper we describe the procedure to orient the electron polarization vector vertically, and the concept of determining both its magnitude and orientation with the available setup. A sophisticated method has been developed to overcome the lack of a polarimeter setup sensitive to the vertical polarization component.

  14. Late-term abortion.

    PubMed

    Epner, J E; Jonas, H S; Seckinger, D L

    1998-08-26

    Recent proposed federal legislation banning certain abortion procedures, particularly intact dilatation and extraction, would modify the US Criminal Code such that physicians performing these procedures would be liable for monetary and statutory damages. Clarification of medical procedures is important because some of the procedures used to induce abortion prior to viability are identical or similar to postviability procedures. This article reviews the scientific and medical information on late-term abortion and late-term abortion techniques and includes data on the prevalence of late-term abortion, abortion-related mortality and morbidity rates, and legal issues regarding fetal viability and the balance of maternal and fetal interests. According to enacted American Medical Association (AMA) policy, the use of appropriate medical terminology is critical in defining late-term abortion procedures, particularly intact dilatation and extraction, which is a variant of but distinct from dilatation and evacuation. The AMA recommends that the intact dilatation and extraction procedure not be used unless alternative procedures pose materially greater risk to the woman and that abortions not be performed in the third trimester except in cases of serious fetal anomalies incompatible with life. Major medical societies are urged to collaborate on clinical guidelines on late-term abortion techniques and circumstances that conform to standards of good medical practice. More research on the advantages and disadvantages of specific abortion procedures would help physicians make informed choices about specific abortion procedures. Expanded ongoing data surveillance systems estimating the prevalence of abortion are also needed.

  15. USAF Summer Research Program - 1994 Summer Faculty Research Program Final Reports, Volume 5B, Wright Laboratory

    DTIC Science & Technology

    1994-12-01

    Research Laboratory Technical Directorates and Air Force Air Logistics Centers. Each participant provided a report of their research , and these...reports are consolidated into this annual report. 14. SUBJECT TERMS AIR FORCE RESEARCH , AIR FORCE , ENGINEERING, LABORATORIES , REPORTS, SUMMER...216-6940 UNITED STATES AIR FORCE SUMMER RESEARCH PROGRAM - 1994 SUMMER FACULTY RESEARCH PROGRAM FINAL REPORTS

  16. The Summer Slide: What We Know and Can Do about Summer Learning Loss

    ERIC Educational Resources Information Center

    Alexander, Karl, Ed.; Pitcock, Sarah, Ed.; Boulay, Matthew C., Ed.

    2016-01-01

    This book is an authoritative examination of summer learning loss, featuring original contributions by scholars and practitioners at the forefront of the movement to understand--and stem--the "summer slide." The contributors provide an up-to-date account of what research has to say about summer learning loss, the conditions in low-income…

  17. Summer Splash. 1988 Wisconsin Summer Library Program Manual. Bulletin No. 8230.

    ERIC Educational Resources Information Center

    Lamb, Donald K.; And Others

    A compilation of materials contributed by and developed with the cooperation of Wisconsin librarians and Ohio's 1987 summer reading program, this planning manual provides guidelines for planning and promoting summer programs for young people by librarians in the state of Wisconsin. The theme of the program, "Summer Splash," is intended…

  18. Summer Matters: Advocating for Summer Learning That Can Weather Political Seasons

    ERIC Educational Resources Information Center

    McQuade, Aaron

    2015-01-01

    Research has shown that an idle summer is not just boring; it can cost a student as much as two to three months of educational progress. Summer is critical to each child's development, both mind and body. Any meaningful attempts to get at America's equity divide and the consequent gap in opportunities for kids must include summer education as a…

  19. Enriching Summer Work: An Evaluation of the Summer Career Exploration Program

    ERIC Educational Resources Information Center

    McClanahan, Wendy S.; Sipe, Cynthia L.; Smith, Thomas J.

    2004-01-01

    To determine the impact of the Summer Career Exploration Program (SCEP), a privately funded summer jobs program for low-income teens, P/PV examined the lives of over 1700 applicants. These youth were randomly assigned to participate or to not participate in SCEP in the summer of 1999, and their outcomes were compared at four and twelve months…

  20. Summer Matters: Advocating for Summer Learning That Can Weather Political Seasons

    ERIC Educational Resources Information Center

    McQuade, Aaron

    2015-01-01

    Research has shown that an idle summer is not just boring; it can cost a student as much as two to three months of educational progress. Summer is critical to each child's development, both mind and body. Any meaningful attempts to get at America's equity divide and the consequent gap in opportunities for kids must include summer education as a…

  1. Greater effect of increasing shrub height on winter versus summer soil temperature

    NASA Astrophysics Data System (ADS)

    Paradis, Mélissa; Lévesque, Esther; Boudreau, Stéphane

    2016-08-01

    Shrub expansion is increasingly observed in arctic and subarctic environments. The development of shrub structure may significantly impact the abiotic environment at the local scale. Our objective was to reconstruct the development of the vertical structure of Betula glandulosa Michx. and to evaluate its effects on winter and summer soil temperature and on snow depth. Stratified sampling of the shrub revealed that shrub biomass distribution followed a similar pattern in stands of contrasting heights. Woody biomass was maximal in the lower stratum and relatively stable in the intermediate strata, while the foliar biomass tracked the vertical development of the shrub structure. Dendrochronological analysis revealed that shrub stands are relatively young; most of the dominant stems started their development after 1990. Shrub height was positively associated with both the dominant stem age and its vertical growth rate. Temperature differences among sites were greater during winter (ca 10 °C) than during summer (ca 2 °C), while the sum of freezing degree-days varied from 680 °C to 2125 °C. Shrub height was the most plausible variable explaining snow depth, winter ground level temperature and the sum of freezing degree-days. However, woody biomass in the 30-40 cm strata best explained summer ground level temperature. Our results suggest that the development of a shrub structure will have far-reaching consequences on the abiotic environment of subarctic ecosystems.

  2. Manual for a Summer Reading Program.

    ERIC Educational Resources Information Center

    Medina, Sue O.

    This manual provides suggestions for materials and projects to carry out a summer reading program for children based on a monster theme. The planning process outlined may be used as a "how-to" guide for developing summer reading programs on other themes as well. In addition to general guidelines, the manual provides information on the following…

  3. Summer Melts Immigrant Students' College Plans

    ERIC Educational Resources Information Center

    Naranjo, Melissa M.; Pang, Valerie Ooka; Alvarado, Jose Luis

    2016-01-01

    Many college-intending students find themselves dealing with the undermatch and summer melt phenomena. Undermatch refers to the situation where academically-successful high-school graduates choose not to go to any college or to go to a local community college not commensurate with their academic achievements. Summer melt describes how students may…

  4. Summer Melts Immigrant Students' College Plans

    ERIC Educational Resources Information Center

    Naranjo, Melissa M.; Pang, Valerie Ooka; Alvarado, Jose Luis

    2016-01-01

    Many college-intending students find themselves dealing with the undermatch and summer melt phenomena. Undermatch refers to the situation where academically-successful high-school graduates choose not to go to any college or to go to a local community college not commensurate with their academic achievements. Summer melt describes how students may…

  5. Six for Summer: Professional Learning Opportunities

    ERIC Educational Resources Information Center

    Curran, Ben

    2014-01-01

    Teaching is and always has been a year-round job. Even when educators are not working during the summer months, they are always planning for the year ahead. This has not changed in the 21st century. In fact, teachers might work harder now than ever. While summer is the perfect time for teachers to relax and recharge their batteries, it also…

  6. 46 CFR 45.53 - Summer freeboard.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Summer freeboard. 45.53 Section 45.53 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD LINES GREAT LAKES LOAD LINES Freeboards § 45.53 Summer freeboard. (a) Except as required in paragraph (c) of this section, the minimum freeboard in...

  7. 46 CFR 45.53 - Summer freeboard.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Summer freeboard. 45.53 Section 45.53 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD LINES GREAT LAKES LOAD LINES Freeboards § 45.53 Summer freeboard. (a) Except as required in paragraph (c) of this section, the minimum freeboard in...

  8. The Duke University Summer Transitional Program.

    ERIC Educational Resources Information Center

    Southern Regional Education Board, Atlanta, GA.

    This report describes the Summer Transitional Program (STP) at Duke University as analyzed by the principal leadership of the program and by others who participated in its evaluation. The program, initiated in the summer of 1969, was designed to provide academic and social orientation for approximately 40 participants. Evaluation of the 1969,…

  9. Summer Programming in Rural Communities: Unique Challenges

    ERIC Educational Resources Information Center

    Phillips, Ruthellen; Harper, Stacey; Gamble, Susan

    2007-01-01

    During the past several decades, child poverty rates have been higher in rural than in urban areas, and now 2.5 million children live in deep poverty in rural America. Studies indicate that poor children are most affected by the typical "summer slide." Summer programming has the ability to address the issues of academic loss, nutritional…

  10. Districts Add Web Courses for Summer

    ERIC Educational Resources Information Center

    Borja, Rhea R.

    2005-01-01

    More and more school districts, as well as for-profit companies and nonprofit organizations, are offering Internet-based summer classes in core subjects, such as algebra and reading, and electives such as creative writing. In this article, the author discusses the growth of enrollment in online education for summer. The logistical ease of…

  11. Report on the 2008 ISAGA Summer School

    ERIC Educational Resources Information Center

    van de Westelaken, Marleen

    2011-01-01

    This article reports on the 2008 ISAGA Summer School held in New Delhi (Gurgaon), India. This Summer School was hosted by the Institute for Integrated Learning in Management. Participants came from all over the world. This year's theme was "The Art and Science of Simulation and Gaming Design and Facilitation for Business and Management."

  12. Building Effective Programs for Summer Learning.

    ERIC Educational Resources Information Center

    Johnson, Peter

    Summer learning comes from reading books, singing songs, playing games, listening to stories, taking trips, and all kinds of other fun activities that kids rarely realize are actually good for them. However, this kind of summer learning can be more difficult for children of low-income and other disadvantaged families. Careful analysis of…

  13. Districts Add Web Courses for Summer

    ERIC Educational Resources Information Center

    Borja, Rhea R.

    2005-01-01

    More and more school districts, as well as for-profit companies and nonprofit organizations, are offering Internet-based summer classes in core subjects, such as algebra and reading, and electives such as creative writing. In this article, the author discusses the growth of enrollment in online education for summer. The logistical ease of…

  14. Six for Summer: Professional Learning Opportunities

    ERIC Educational Resources Information Center

    Curran, Ben

    2014-01-01

    Teaching is and always has been a year-round job. Even when educators are not working during the summer months, they are always planning for the year ahead. This has not changed in the 21st century. In fact, teachers might work harder now than ever. While summer is the perfect time for teachers to relax and recharge their batteries, it also…

  15. Academic Camps: Why Spend Summer in Class?

    ERIC Educational Resources Information Center

    Rigby, Kristin

    2005-01-01

    Gifted students tend to be drawn to summer gifted programs because of their high level of motivation and their drive to experience an academic challenge (Olszewski-Kubilius & Lee, 2004). Concurrently, academic summer programs yield numerous social-emotional, educational, and family benefits for gifted young people. One of the most beneficial…

  16. The Summer Learning of Exceptional Students

    ERIC Educational Resources Information Center

    Gershenson, Seth; Hayes, Michael S.

    2017-01-01

    The summer activities and summer learning of exceptional students--students who have an individualized education plan or who are English-language learners--are potentially important yet understudied. We analyze nationally representative survey data to fill this gap. Exceptional students are significantly less likely than their mainstream…

  17. I Know What You Did Last Summer

    ERIC Educational Resources Information Center

    Opalinski, Gail; Ellers, Sherry; Goodman, Amy

    2004-01-01

    This article describes the revised summer school program developed by the Anchorage (AK) School District for students who received poor grades in their core classes or low scores in the Alaska Benchmark Examinations or California Achievement Tests. More than 500 middle school students from the district spent five weeks during the summer honing…

  18. Summer Programming in Rural Communities: Unique Challenges

    ERIC Educational Resources Information Center

    Phillips, Ruthellen; Harper, Stacey; Gamble, Susan

    2007-01-01

    During the past several decades, child poverty rates have been higher in rural than in urban areas, and now 2.5 million children live in deep poverty in rural America. Studies indicate that poor children are most affected by the typical "summer slide." Summer programming has the ability to address the issues of academic loss, nutritional…

  19. Summer Camp of Mathematical Modeling in China

    ERIC Educational Resources Information Center

    Tian, Xiaoxi; Xie, Jinxing

    2013-01-01

    The Summer Camp of Mathematical Modeling in China is a recently created experience designed to further Chinese students' academic pursuits in mathematical modeling. Students are given more than three months to research on a mathematical modeling project. Researchers and teams with outstanding projects are invited to the Summer Camp to present…

  20. Report on the 2008 ISAGA Summer School

    ERIC Educational Resources Information Center

    van de Westelaken, Marleen

    2011-01-01

    This article reports on the 2008 ISAGA Summer School held in New Delhi (Gurgaon), India. This Summer School was hosted by the Institute for Integrated Learning in Management. Participants came from all over the world. This year's theme was "The Art and Science of Simulation and Gaming Design and Facilitation for Business and Management."