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Sample records for inter annual patterns

  1. Seasonal and inter-annual snowmelt patterns in the southern Sierra Nevada, California

    NASA Astrophysics Data System (ADS)

    Musselman, K. N.; Molotch, N. P.; Margulis, S. A.

    2012-12-01

    In the Sierra Nevada, seasonal snow represents a critical component of California's water resource infrastructure in that it affords reliable water during otherwise arid summers. Complex spatial, seasonal and inter-annual snowmelt patterns determine when and where that meltwater is available. Our knowledge of snowmelt dynamics is typically limited to what we can infer from sparse, point-scale snow measurement stations. Limitations such as these motivate the use of numerical snowmelt models. We evaluate the ability of the Alpine3D model system to represent three years of snow dynamics over an 1800 km2 area of Sequoia National Park. The domain spans a 3600 m elevation gradient and ecosystems ranging from semi-arid grasslands to massive sequoia stands to alpine tundra. The model results were evaluated against data from a multi-scale measurement campaign that included airborne LiDAR, clusters of snow depth sensors, repeated manual snow surveys, and automated SWE stations. Compared to these measurements, Alpine3D consistently performed well in middle elevation conifer forests; compared to LiDAR data, the mean snow depth error in forested regions was < 2%. The model also simulated the snow disappearance date within two days of that measured by regional automated sensors. At upper elevations, however, the model tended to overestimate SWE by 50% to as much as 100% in some areas and the errors were linearly correlated (R2 > 0.80, p<0.01) with the distance of the SWE measurements from the nearest precipitation gauge used to derive the model forcing. The results suggest that Alpine3D is highly accurate during the melt season and that precipitation uncertainty may be a critical limitation on snow model accuracy. Finally, an analysis of seasonal and inter-annual snowmelt patterns highlighted distinct melt differences between lower, middle, and upper elevations. Snowmelt was generally most frequent (70% - 95% of the snow-covered season) at the lower elevations where snow cover

  2. Inter-annual patterns of aggression and pair bonding in captive American flamingos (Phoenicopterus ruber).

    PubMed

    Frumkin, Nathan B; Wey, Tina W; Exnicios, Megan; Benham, Caroline; Hinton, Mitchell G; Lantz, Samantha; Atherton, Carolyn; Forde, Debbie; Karubian, Jordan

    2016-01-01

    Because zoos typically house animals for extended periods of time, longitudinal studies can play an important role in evaluating and optimizing animal care and management. For example, information on patterns of aggression and mating behavior across years can be used to monitor well-being, assess response to changes to group composition, and promote successful reproduction. Here, we report on patterns of aggression and pair bonding by American flamingos (Phoenicopterus ruber) at the Audubon Zoo, New Orleans USA across 4 years (2012-2015), a period that included a simultaneous introduction and removal of individuals in 2014. At the population level, overall rates and social network indices of aggressive interactions were relatively stable over the study period, without a strong signal of the 2014 replacement event. At the individual level, flamingos exhibited a high degree of within-individual consistency in levels of aggression initiated (W = 0.530, P < 0.001), and received (W = 0.369, P = 0.042). In terms of pair bonds, females re-paired with the same individuals across years more frequently (between 58% and 100% from year to year) than they switched mates, and no bonds were established between pre-existing and introduced individuals. These findings indicate a high degree of stability in aggression and pair bonding behavior in this population of captive flamingos, at both the population and individual level. Longitudinal studies such as this one provide an opportunity to better our understanding of flamingos and other long-lived, group-living animals along with their management needs, especially in terms of maintaining social cohesion in captivity and improving captive breeding programs.

  3. Five years of phenological monitoring in a mountain grassland: inter-annual patterns and evaluation of the sampling protocol.

    PubMed

    Filippa, Gianluca; Cremonese, Edoardo; Galvagno, Marta; Migliavacca, Mirco; Morra di Cella, Umberto; Petey, Martina; Siniscalco, Consolata

    2015-12-01

    The increasingly important effect of climate change and extremes on alpine phenology highlights the need to establish accurate monitoring methods to track inter-annual variation (IAV) and long-term trends in plant phenology. We evaluated four different indices of phenological development (two for plant productivity, i.e., green biomass and leaf area index; two for plant greenness, i.e., greenness from visual inspection and from digital images) from a 5-year monitoring of ecosystem phenology, here defined as the seasonal development of the grassland canopy, in a subalpine grassland site (NW Alps). Our aim was to establish an effective observation strategy that enables the detection of shifts in grassland phenology in response to climate trends and meteorological extremes. The seasonal development of the vegetation at this site appears strongly controlled by snowmelt mostly in its first stages and to a lesser extent in the overall development trajectory. All indices were able to detect an anomalous beginning of the growing season in 2011 due to an exceptionally early snowmelt, whereas only some of them revealed a later beginning of the growing season in 2013 due to a late snowmelt. A method is developed to derive the number of samples that maximise the trade-off between sampling effort and accuracy in IAV detection in the context of long-term phenology monitoring programmes. Results show that spring phenology requires a smaller number of samples than autumn phenology to track a given target of IAV. Additionally, productivity indices (leaf area index and green biomass) have a higher sampling requirement than greenness derived from visual estimation and from the analysis of digital images. Of the latter two, the analysis of digital images stands out as the more effective, rapid and objective method to detect IAV in vegetation development.

  4. From egg production to recruits: Connectivity and inter-annual variability in the recruitment patterns of European anchovy in the northwestern Mediterranean

    NASA Astrophysics Data System (ADS)

    Ospina-Alvarez, Andres; Catalán, Ignacio A.; Bernal, Miguel; Roos, David; Palomera, Isabel

    2015-11-01

    We show the application of a Spatially-Explicit Individual-Based Model (SEIBM) to understand the recruitment process of European anchovy. The SEIBM is applied to simulate the effects of inter-annual variability in parental population spawning behavior and intensity, and ocean dynamics, on the dispersal of eggs and larvae from the spawning area in the Gulf of Lions (GoL) towards the coastal nursery areas in the GoL and Catalan Sea (northwestern Mediterranean Sea). For each of seven years (2003-2009), we initialize the SEIBM with the real positions of anchovy eggs during the spawning peak, from an acoustics-derived eggs production model. We analyze the effect of spawners' distribution, timing of spawning, and oceanographic conditions on the connectivity patterns, growth, dispersal distance and late-larval recruitment (14 mm larva recruits, R14) patterns. The area of influence of the Rhône river plume was identified as having a high probability of larval recruitment success (64%), but up to 36% of R14 larvae end up in the Catalan Coast. We demonstrate that the spatial paths of larvae differ dramatically from year to year, and suggest potential offshore nursery grounds. We showed that our simulations are coherent with existing recruitment proxies and therefore open new possibilities for fisheries management.

  5. Inter-American Foundation Annual Report 1987.

    ERIC Educational Resources Information Center

    Inter-American Foundation, Rosslyn, VA.

    This annual report from the Inter-American Foundation (IAF), a federal development agency, includes letters from foundation officials describing the IAF-funded work in poverty areas of Latin America and the Caribbean. The report describes IAF's In-Country Support System (ICS), staffed by local professionals who assist grantees and report their…

  6. Seasonal and Inter-Annual Patterns in Ecosystem-Scale Photosynthesis and Respiration in a Temperate Forest Revealed by Isotopic Partitioning of NEE

    NASA Astrophysics Data System (ADS)

    Wehr, R. A.; Munger, J. W.; McManus, J. B.; Nelson, D. D.; Zahniser, M. S.; Wofsy, S. C.; Saleska, S. R.

    2014-12-01

    Measurements of the isotopic composition of the net ecosystem-atmosphere exchange of CO2 (NEE) can be used to partition that exchange into its photosynthetic and respiratory components on an hourly basis, without the need for a priori assumptions about the responses of those components to environmental drivers. This method relies on photosynthesis and respiration having distinct isotopic signatures, which they generally do because the photosynthetic signature varies hourly (e.g. with light availability), whereas the respiratory signature is governed mostly by soil substrate composition and so varies only daily or weekly. Since 2011, we have been measuring the isotopic composition of NEE in a temperate deciduous forest by eddy covariance, using a quantum cascade laser spectrometer. Previously presented isotopic partitioning of the 2011 growing season indicated that ecosystem photosynthesis became more efficient through the summer (with respect to light and water use) and that during the hot, dry period in July, daytime ecosystem respiration was more strongly limited by soil moisture than was nighttime respiration, leading standard non-isotopic partitioning to substantially overestimate daytime ecosystem respiration and hence photosynthesis. Here we extend our analysis to span the three-year period from 2011 through 2013, taking advantage of large inter-annual differences in the seasonal pattern of soil moisture at the forest to test the prediction that standard partitioning exaggerates daytime ecosystem respiration and photosynthesis under drought conditions, and to further explore the mechanisms behind the apparent increase in photosynthetic efficiency through the summer.

  7. Inter-American Foundation Annual Report 1989.

    ERIC Educational Resources Information Center

    Inter-American Foundation, Rosslyn, VA.

    The Inter-American Foundation (IAF), an independent agency created by Congress, funds local private organizations that support the self-help efforts of the poor in 25 Latin American and Caribbean countries. In fiscal year 1989, IAF approved 208 new grants, 175 grant supplements, and other program activities totaling over $25 million. The average…

  8. Inter-American Foundation Annual Report 1988.

    ERIC Educational Resources Information Center

    Inter-American Foundation, Rosslyn, VA.

    The Inter-American Foundation (IAF), an independent agency created by Congress, funds local private organizations that support the self-help efforts of the poor in Latin America and the Caribbean. In fiscal year 1988, IAF approved 208 new grants, 173 grant supplements, and other program activities totaling nearly $25 million. The average grant…

  9. Lakes in permafrost areas - inter- and intra-annual variations

    NASA Astrophysics Data System (ADS)

    Bartsch, Annett; Widhalm, Barbara; Leibman, Marina; Khomutov, Artem

    2016-04-01

    Climate change is pronounced in the Arctic. Increasing temperatures above the global mean are expected for most of the region. This has an effect on soil temperature and thus the extent of permafrost. Lakes are a characteristic feature of lowland permafrost. Their changes as detected with satellite data are often interpreted as indicator for climate change. They are however in many cases connected to flood plains and thus undergo seasonal changes which are not confined to the period just after snowmelt. The Yamal peninsula is one of the areas from which changes have been reported (active layer thickness measurements for more than 20 years) and where it is expected that continuous permafrost will not be present anymore towards the end of this century. It has been already shown in the past that seasonal variations are common in several parts of the peninsula. These need to be considered for longterm studies based on lake monitoring. This requires high temporal resolution which can be only achieved with high resolution radar information (SAR which is cloud independent). The ENVISAT ASAR archive provided data for initial studies covering 2007 and 2008. This time series has been now extended with TerraSAR-X to 2015 for hotspots of variations and changes (shrinking versus emerging vegetation) verified by in-situ observations. The new data also provide better spatial detail (3 m compared to 75m). Inter and intra-annual variations have been quantified in space and time. The temporal pattern has been also analyzed with respect to snowmelt timing (obtained by satellite and ground temperature observations). Results are discussed with respect to previous inundation trend studies based on global coarse resolution (>25 km) datasets which depict significant changes on the peninsula.

  10. On the use of a water balance to evaluate inter-annual terrestrial ET variability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Accurately measuring inter-annual variability in terrestrial evapotranspiration (ET) is a major challenge for efforts to detect inter-annual variability in the hydrologic cycle. Based on comparisons with annual ET values derived from a terrestrial water balance analysis, past research has cast doubt...

  11. The Greenland Sea Odden: Intra- and inter-annual variability

    USGS Publications Warehouse

    Russell, C.A.; Fischer, K.W.; Shuchman, R.A.; Josberger, E.G.

    1997-01-01

    The "Odden" is a large sea ice feature that forms in the East Greenland Sea which generally forms at the beginning of the winter season and can cover 300,000 km2. Throughout the winter, the outer edge of the Odden may advance and retreat by several hundred kilometers on time scales of a few days to weeks. Satellite passive microwave observations from 1978 through 1995 provide a continuous record of the spatial and temporal variations of this extremely dynamic phenomenon. The 17 year record shows both strong inter- and intra-annual variations in Odden extent and temporal behavior. An analysis of the satellite passive microwave derived ice area and extent time series along with meteorological data from the Arctic Drifting Buoy Network determined the meteorological forcing required for Odden growth, maintenance and decay. The key meteorological parameters which cause the rapid ice formation and decay associated with the Odden are, in order of importance, air temperature, wind speed, and wind direction. Atmospheric pressure was found not to play a significant role in the Odden events. Air temperature and wind direction are the dominant variables with temperatures below -9.5??C and winds from the west required to trigger significant Odden ice formation events. ??2004 Copyright SPIE - The International Society for Optical Engineering.

  12. Inter-annual variability in Alaskan net ecosystem CO2 exchange

    NASA Astrophysics Data System (ADS)

    Luus, Kristina; Lindaas, Jakob; Commane, Roisin; Euskirchen, Eugenie; Oechel, Walter; Zona, Donatella; Chang, Rachel; Kelly, Richard; Miller, Charles; Wofsy, Steven; Lin, John

    2015-04-01

    The high-latitude biospheric carbon cycle's responses to climate change are predicted to have an important role in determining future atmospheric concentrations of CO2. In response to warming soil and air temperatures, Arctic wetlands have been observed to increase rates of both soil C efflux and vegetation C uptake through photosynthesis. However, insights into the regional-scale consequences of these processes for net C uptake have been limited by the large uncertainties existing in process-based model estimates of Arctic net ecosystem CO2 exchange (NEE). The Polar Vegetation Photosynthesis and Respiration Model (PolarVPRM) instead provides data-driven, satellite-based estimates of high-latitude NEE, using a framework which specifically accounts for polar influences on NEE. PolarVPRM calculates NEE as the sum of respiration (R) and gross ecosystem exchange (GEE), where GEE refers to the light-dependent portion of NEE: NEE= -GEE + R. Meteorological inputs for PolarVPRM are provided by the North American Regional Reanalysis (NARR), and land surface inputs are acquired from the Moderate Resolution Imaging Spectroradiometer (MODIS). Growing season R is calculated from air temperature, and subnivean R is calculated according to soil temperature. GEE is calculated according to shortwave radiation, air temperature, and MODIS-derived estimates of soil moisture and vegetation biomass. Previously, model validation has indicated that PolarVPRM showed reasonably good agreement with eddy covariance observations at nine North American Arctic sites, of which three were used for calibration purposes. For this project, PolarVPRM NEE was calculated year-round across Alaska at a three-hourly temporal resolution and a spatial resolution of 1 6°×1 4° (latitude × longitude). The objective of this work was to gain insight into inter-annual variability in Alaskan NEE, R and GEE, and an understanding of which meteorological and land surface drivers account for these observed patterns

  13. High resolution Greenland ice sheet inter-annual mass variations combining GRACE gravimetry and Envisat altimetry

    NASA Astrophysics Data System (ADS)

    Su, Xiaoli; Shum, C. K.; Guo, Junyi; Duan, Jianbin; Howat, Ian; Yi, Yuchan

    2015-07-01

    Inter-annual mass variations of the Greenland ice sheet (GrIS) are important for improving mass balance estimates, validation of atmospheric circulation models and their potential improvement. By combining observed inter-annual variations from Gravity Recovery and Climate Experiment (GRACE) and Environmental Satellite (Envisat) altimetry data over the period from January 2003 to December 2009, we are able to estimate the nominal density, with the objective of obtaining higher resolution mass changes using altimeter data at the inter-annual scale. We find high correlations between these two inter-annual variations on the order of 0.7 over 60% of the GrIS, in particular over the west side along the central ice divide. Significant negative correlations are found in parts of Northeast and Southeast GrIS, where negative inter-annual variation correlations were also found between mass change from GRACE and snow depth from ECMWF reanalysis in a previous study. In the regions of positive correlation, the estimated nominal densities range from 383.7 ± 50.9 to 596.2 ± 34.1 kgm-3. We demonstrate the feasibility of obtaining high-resolution inter-annual mass variation over Southwest GrIS, one of the regions with positive correlations, based on density-corrected Envisat altimetry, 2003-2009. A definitive explanation for the existence of regions of negative correlation remains elusive.

  14. Extreme rainfall events can alter inter-annual biomass responses to water and N enrichment

    NASA Astrophysics Data System (ADS)

    Kong, D. L.; Lü, X. T.; Jiang, L. L.; Wu, H. F.; Miao, Y.; Kardol, P.

    2013-12-01

    Water availability has profound effects on plant growth and productivity in temperate and semiarid grasslands. However, it remains unclear how variation of inter-annual precipitation by extreme rainfall events will alter the aboveground and belowground responses of plants, and how these responses may be contingent on N availability. In this study, we examined the interactive effects of inter-annual precipitation variation and N addition on aboveground and live fine root biomass of a semiarid grassland in northern China for two consecutive years (2007 and 2008). Inter-annual variation in precipitation resulting mainly from the occurrence of extreme rainfall events in 2008 significantly affected above- and belowground plant biomass responses to water addition. In addition, variation of inter-annual precipitation by this extreme rainfall event suppressed plant responses to nitrogen addition and reduced the interaction effects between water and nitrogen addition. These effects of inter-annual precipitation fluctuation could be attributed to the negative influence of the extreme rainfall event on soil N and water availability, ultimately reducing plant rainfall use efficiency and nitrogen use efficiency. In conclusion, our results suggest ecosystem responses to water and N enrichment could be altered by inter-annual variation of precipitation regime caused by the naturally occurring extreme rainfall events.

  15. Inter-Annual Variability of Aerosol Optical Depth over East Asia during 2000-2011 summers

    NASA Astrophysics Data System (ADS)

    Liu, J.; Liu, Y.; Tao, S.

    2013-12-01

    Aerosols degrade air quality, perturb atmospheric radiation, and impact regional and global climate. Due to a rapid increase of anthropogenic emissions, aerosol loading over East Asia (EA) is markedly higher than other industrialized regions, motivating a need to characterize the evolution of aerosols and understand the associated drivers. Based on the MISR satellite data during 2000-2011, a wave-like inter-annual variation of summertime aerosol optical depth (SAOD) is observed over the highly populated North China Plain (NCP) in East Asia. Specifically, the peak to trough ratio of SAOD ranges from 1.4 to 1.6, with a period of 3-4y. This variation pattern differs apparently from what has been seen in EA emissions, indicating a periodic change in regional climate pattern during the past decade. Investigations on meteorological fields over the region reveal that the high SAOD is generally associated with enhanced Philippine Sea Anticyclone Anomaly (PSAA), which weakens southeasterlies over northeastern EA and depresses air ventilation. Alternatively, a higher temperature or lower relative humidity is found to be coincident with reduced SAOD. The behavior of PSAA has been found previously to be modulated by the El Niño southern oscillations (ENSO), which thereby could disturb the EA SAOD as well. Rather than changing coherently with the ENSO activity, SAOD peaks over the NCP are found to be accompanied by the rapid transition of El Niño warm to cold phases developed four months ahead. An index measuring the ENSO development during January-April is able to capture the inter-annual variability of NCP SAOD during 2000-2011. This indicates a need to integrate the consideration of large-scale periodic climate variability in the design of regional air quality policy.

  16. A view of annual water quality cycle and inter-annual variations in agricultural headwater catchment (Kervidy-Naizin, France)

    NASA Astrophysics Data System (ADS)

    Aubert, A.; Gascuel-odoux, C.; Merot, P.; Grimaldi, C.; Gruau, G.; Ruiz, L.

    2011-12-01

    Climatic conditions impact biotransformation and transfer of solutes. Therefore, they modify solute emissions in streams. Studying these modifications requires long term and detailed monitoring of both internal processes and river loads, which are rarely combined. The Kervidy-Naizin catchment, implemented in 1993, is part of the French network of catchment for environmental research (SOERE RBV, focused on the Critical Zone). It is an intensive agricultural catchment located in a temperate climate in Western France (Brittany) (Molenat et al., 2008; Morel et al., 2009). It presents shallow aquifers due to impervious bedrock. Both hydrology and water chemistry are monitored with a daily time step since 2000-01, as well as possible explanatory data (land use, meteorology, etc.). Concentrations in major anions in this catchment are extremely high, which make people call it a "saturated" catchment. We identified annual patterns for chloride, sulphate, dissolved organic and inorganic carbon and nitrate concentration variations. First, we considered the complete set of concentration data as function of the time. From that, we foresaw 3 cyclic temporal patterns. Then, from representing the concentrations as function of meteorological parameters, intra-annual hysteretic variations and their inter-annual variations were clearly identified. Our driving question is to know if and how climatic conditions are responsible for variations of the patterns in and between years. In winter, i.e. rainy and cold period, rainfall is closely linked to discharge because of a direct recharge to the shallow groundwater. Reversely, in transition periods (spring and fall) and hot periods, both rainfall and temperature influences discharge in relation to their range of variations. Moreover, biological processes, driven by temperature and wetness, also act during these periods. On the whole, we can emphasize the specificity of water chemistry patterns for each element. Noticeable differences

  17. Soil moisture controls on inter-annual variability of biogenic isoprene emissions and ozone

    NASA Astrophysics Data System (ADS)

    Tawfik, A. B.; Shalaby, A.; Steiner, A. L.; Zakey, A.

    2010-12-01

    Biogenic isoprene emissions directly respond to leaf temperature, photosynthetic active radiation, and soil moisture. These climate variables can be important for estimating biogenic emissions and their impact on interannual variability of ground-level ozone and secondary organic aerosol. Due to the non-linear relationship between temperature and soil moisture, observational data alone are not capable of quantifying each variable’s contribution to isoprene emissions. A process-based emissions model (the Model of Emissions of Gases and Aerosols from Nature; MEGAN) is coupled to a regional climate and chemistry model (RegCM-CLM-CHEM) to assess the contributions of environmental variables controlling isoprene emissions on climatological time scales. A fully online simulation was performed from 1994-2008 where isoprene emissions respond at each land surface time step to all environmental variables. A first order Taylor expansion method was used to determine percent contribution to inter-annual isoprene variability from each environmental variable. In July, leaf temperature accounts for more than 65% of inter-annual variations in isoprene emissions over the Plains and the Great Lakes region. However, soil moisture variations tend to dominate controls on inter-annual variability for the southeastern U.S. (> 60%). Model simulations and observational data from the Photochemical Assessment Monitoring Stations (PAMS) are implemented to estimate the effects of drought on inter-annual variations of isoprene and ozone.

  18. Inter- and intra-annual patterns of Ulva prolifera green tides in the Yellow Sea during 2007-2009, their origin and relationship to the expansion of coastal seaweed aquaculture in China.

    PubMed

    Keesing, John K; Liu, Dongyan; Fearns, Peter; Garcia, Rodrigo

    2011-06-01

    The large green-tide events that occurred in the Yellow Sea in 2008 (3489km(2)) and 2009 (4994km(2)) are shown to be novel events preceded only once by a much smaller event in 2007 (82km(2)). The blooms originated in the coastal area of Jiangsu province and spread north-east towards the Shandong Peninsula. The blooms grew at different rates and mesoscale variability in surface winds explained the differences in the spatial and temporal patterns of blooms in 2008 and 2009. The 2009 bloom was tracked to its origin immediately offshore of extensive intertidal flats between Yancheng and Nantong where recent rapid expansion of Porphyra aquaculture has occurred. We review published hypotheses which have been advanced to explain the occurrence of blooms and in light of our findings, we conclude that the accumulation and disposal of waste Ulva prolifera from Porphyra aquaculture rafts is the most likely cause of the blooms.

  19. Inter-annual variation in the foraging ecology of a brown bear population in southwest Alaska

    NASA Astrophysics Data System (ADS)

    Stricker, C. A.; Kovach, S. D.; Collins, G. H.; Farley, S. D.; Rye, R. O.; Hinkes, M. T.

    2010-12-01

    Brown bear (Ursus arctos) population size correlates with density of high-quality food resources. We report on a ten-year study (1993 - 2003) of brown bear nutritional ecology in southwestern Alaska during which changes in resource availability and density occurred. The diets of 21 female bears captured multiple years were characterized by stable isotope analysis (δ13C, δ15N, and δ34S) of guard hairs and putative diet items, followed by application of a Bayesian mixing model to derive assimilated diet estimates. Diet estimates were subsequently used to characterize individual-level resource specialization. Over the entire study period, salmon accounted for the highest proportion of bear diets (42.1%), followed by berries (24.5%), mammals (13.5%), freshwater fish (11.2%), and other plant matter (8.7%). The average salmon contribution to bear diets declined significantly from 48% to 34% following a precipitous reduction in salmon escapement mid-way through the study, after which the bear population shifted toward a more generalist diet. However, evaluation of individual animals recaptured multiple times during the study revealed variation in inter-annual dietary habits unrelated to the salmon crash. Individual variation presumably reflects local density changes in a variety of resources, with concomitant annual shifts in the degree of individual specialization. We also relate these patterns to other individual traits, such as reproductive status, home range, and habitat use to better constrain foraging habits. This study provides unique insights into the nutritional ecology of Alaskan brown bears and complements traditional wildlife studies by offering important covariates to better understand changes in population vital rates.

  20. The impact of inter-annual variability in hydrodynamic conditions on plaice settlement success

    NASA Astrophysics Data System (ADS)

    Tiessen, Meinard; Gerkema, Theo; Ruardij, Piet; van der Veer, Henk

    2014-05-01

    Using a hydrodynamic model coupled to a particle tracking routine, the impact of variability in hydrodynamic conditions on drifting plaice eggs and larvae and their successful settlement in nursery areas was studied. The life cycle of many marine fish species consists of various life stages: Spawning at open sea, pelagic egg and larval stages and often a juvenile stage bound to shallow water nursery grounds. Numerous studies have demonstrated that pelagic stages appear to be the most critical in determining ultimate year-class success, which holds true, for example, for European plaice (Pleuronectes platessa). Plaice spawning grounds in the middle of the North Sea and in the English Channel are connected to juvenile nursery areas (such as the Wadden Sea) via (semi-)passive drift governed by residual currents. Field data from especially the Balgzand nursery area have shown a strong variability in the number of plaice juveniles settling there over the years. Changes to current patterns and water temperatures are expected to strongly contribute to this inter-annual variability in settlement success. Here, we investigate these effects on pelagic plaice drift and settlement using a coupled numerical model: A 3D hydrodynamic model (GETM) was used to produce hydrodynamic data at a high spatial and temporal resolution, for the years 1994 - 2005. This data was subsequently fed into a particle tracking routine (GITM), that computed the trajectories for a million particles (representing pelagic plaice) for each year. In order to focus on the physical processes, several biological contributions such as behaviour (vertical migration) and mortality were excluded from the simulations. Spawning periods and locations, drift durations, and settlement requirements were selected around known plaice characteristics. Results showed a strong inter-annual variability in the drift direction, drift duration and settlement success of the particles, as well as in the absolute number of

  1. Measurement of inter- and intra-annual variability of landscape fire activity at a continental scale: the Australian case

    NASA Astrophysics Data System (ADS)

    Williamson, Grant J.; Prior, Lynda D.; Jolly, W. Matt; Cochrane, Mark A.; Murphy, Brett P.; Bowman, David M. J. S.

    2016-03-01

    Climate dynamics at diurnal, seasonal and inter-annual scales shape global fire activity, although difficulties of assembling reliable fire and meteorological data with sufficient spatio-temporal resolution have frustrated quantification of this variability. Using Australia as a case study, we combine data from 4760 meteorological stations with 12 years of satellite-derived active fire detections to determine day and night time fire activity, fire season start and end dates, and inter-annual variability, across 61 objectively defined climate regions in three climate zones (monsoon tropics, arid and temperate). We show that geographic patterns of landscape burning (onset and duration) are related to fire weather, resulting in a latitudinal gradient from the monsoon tropics in winter, through the arid zone in all seasons except winter, and then to the temperate zone in summer and autumn. Peak fire activity precedes maximum lightning activity by several months in all regions, signalling the importance of human ignitions in shaping fire seasons. We determined median daily McArthur forest fire danger index (FFDI50) for days and nights when fires were detected: FFDI50 varied substantially between climate zones, reflecting effects of fire management in the temperate zone, fuel limitation in the arid zone and abundance of flammable grasses in the monsoon tropical zone. We found correlations between the proportion of days when FFDI exceeds FFDI50 and the Southern Oscillation index across the arid zone during spring and summer, and Indian Ocean dipole mode index across south-eastern Australia during summer. Our study demonstrates that Australia has a long fire weather season with high inter-annual variability relative to all other continents, making it difficult to detect long term trends. It also provides a way of establishing robust baselines to track changes to fire seasons, and supports a previous conceptual model highlighting multi-temporal scale effects of climate in

  2. Inter-Annual Variation in Characteristics of Endozoochory by Wild Japanese Macaques

    PubMed Central

    Tsuji, Yamato

    2014-01-01

    Endozoochory is important to the dynamics and regeneration of forest ecosystems. Despite the universality of inter-annual variation in fruit production, few studies have addressed the sign (seed predation versus seed dispersal) and strength (frequency and quantity) of fruit-frugivore interaction and the effectiveness of endozoochory in response to the long-term temporal context. In this study I evaluated the characteristics of endozoochorous dispersal by wild Japanese macaques Macaca fuscata inhabiting deciduous forest in northern Japan for five different years. I collected 378 fecal samples from the macaques in fall (September to November) and quantified the proportion of feces containing seeds, number of seeds per fecal sample, ratio of intact seeds, and seed diversity. The proportion of feces containing seeds of any species (five-year mean: 85.9%, range: 78–97%) did not show significant inter-annual variation, while species-level proportions did. The intact ratio of seeds (mean: 83%, range: 61–98%) varied significantly both between years and between months, and this varied among dominant plant species. The number of seeds per fecal sample (mean: 78, range: 32–102) varied monthly but did not between years, and the seed diversity (mean: 0.66, range: 0.57–0.81) did not show significant inter-annual variation, both of which were attributed to longer duration of macaques’ gastro-intestinal passage time of seeds exceed their feeding bouts. This study demonstrated that frequency and success of seed dispersal over seed predation of macaque endozoochory showed inter-annual variation, indicating low specificity across the seed–macaque network. The temporal variability in the quality of seed dispersal may provide evidence of high resilience in response to fluctuating environmental conditions in the temperate forests. PMID:25272286

  3. Analysis of Seasonal and Inter-Annual Variability in Trans-Pacific Transport

    NASA Astrophysics Data System (ADS)

    Liu, J.; Mauzerall, D. L.; Horowitz, L. W.

    2004-05-01

    We use the global Model of Ozone and Related Tracers, version 2 (MOZART-2) driven with NCEP winds to conduct a simulation from 1991-2002 of the transport of nine continental tracers with uniform emissions and 2-week lifetimes. The purpose of our analysis is to both evaluate the meteorological component of the inter-annual variability of trans-Pacific transport and to derive an algorithm by which we can predict the transport. For each regions emissions we first define average seasonal time-scales for transport in order to describe the average time necessary for each regional tracer to travel from its source to a location downwind. We next define a 'transport potential', the percentage of a tracer emitted from a region that is transported across a meridional plane in the Pacific, and an 'influence potential', the percentage of a tracer emitted from a region that enters into the boundary layer or free troposphere over the United States. These 'potentials' permit a quantification of the seasonal and inter-annual variability in transport of each regional tracer and their relative contribution to the composition of downwind air masses due to the variability of meteorology. Maximum trans-Pacific transport occurs in winter and spring. The East Asian and former Soviet Union regions have the largest transport potential across the Pacific and have the largest influence potential on the U.S. boundary layer composition while the European region is of secondary importance. East Asian and Indian tracers have the largest trans-Pacific transport potential and influence potential in the U.S. free troposphere. Transport and influence potentials are both larger in the free troposphere than in the boundary layer. Vertical subsidence over the continental U.S. is an important entry route for foreign tracers, particularly in winter. Focusing on the East Asian tracer we find that maximum transport occurs at approximately 40°N in the lower to mid-troposphere. Although significant inter-annual

  4. Inter-annual variation of carbon uptake by a plantation oak woodland in south-eastern England

    NASA Astrophysics Data System (ADS)

    Wilkinson, M.; Eaton, E. L.; Broadmeadow, M. S. J.; Morison, J. I. L.

    2012-12-01

    The carbon balance of an 80-yr-old deciduous oak plantation in the temperate oceanic climate of the south-east of Great Britain was measured by eddy covariance over 12 yr (1999-2010). The mean annual net ecosystem productivity (NEP) was 486 g C m-2 yr-1 (95% CI of ±73 g C m-2 yr-1), and this was partitioned into a gross primary productivity (GPP) of 2034 ± 145 g C m-2 yr-1, over a 165 (±6) day growing season, and an annual loss of carbon through respiration and decomposition (ecosystem respiration, Reco) of 1548 ± 122 g C m-2 yr-1. Although the maximum variation of NEP between years was large (333 g C m-2 yr-1), the ratio of Reco/GPP remained relatively constant (0.76 ± 0.02 CI). Some anomalies in the annual patterns of the carbon balance could be linked to particular weather events, such as low summer solar radiation and low soil moisture content (values below 30% by volume). The European-wide heat wave and drought of 2003 did not reduce the NEP of this woodland because of good water supply from the surface-water gley soil. The inter-annual variation in estimated intercepted radiation only accounted for ~ 47% of the variation in GPP, although a significant relationship (p < 0.001) was found between peak leaf area index and annual GPP, which modified the efficiency with which incident radiation was used in net CO2 uptake. Whilst the spring start and late autumn end of the net CO2 uptake period varied substantially (range of 24 and 27 days respectively), annual GPP was not related to growing season length. Severe outbreaks of defoliating moth caterpillars, mostly Tortrix viridana L. and Operophtera brumata L., caused considerable damage to the forest canopy in 2009 and 2010, resulting in reduced GPP in these two years. Inter-annual variation in the sensitivity of Reco to temperature was found to be strongly related to summer soil moisture content. The eddy covariance estimates of NEP closely matched mensuration-based estimates, demonstrating that this forest

  5. An improved estimation of the poleward expansion of coral habitats based on the inter-annual variation of sea surface temperatures

    NASA Astrophysics Data System (ADS)

    Takao, S.; Yamano, H.; Sugihara, K.; Kumagai, N. H.; Fujii, M.; Yamanaka, Y.

    2015-12-01

    The poleward expansion of coral habitats has been observed along the Japanese coast since the 1930s. Previous modeling studies have projected a poleward expansion using decadal-mean sea surface temperatures (SSTs) in the coldest months. However, this poleward expansion could be affected by the inter-annual variation of SST in the coldest months, which has not been considered before. In this study, the simulated pattern of poleward expansion was compared between cases where coral mortality was considered based on the inter-annual variation of SST and the decadal-mean SST in the coldest months. Modeled monthly mean SSTs for historical and future global warming simulations from the most recent climate projection model (MIROC4h) were used. The poleward expansion of corals simulated by considering mortality based on the inter-annual variation of SST in the coldest months better reproduced the observed poleward expansion speed compared to the simulations without such a consideration. Our results show the importance of considering coral mortality based on the inter-annual variation of seawater temperature to produce a more realistic poleward expansion of coral habitats.

  6. Inter-annual precipitation fluctuations alter the responses of above- and belowground biomass to water and N enrichment

    NASA Astrophysics Data System (ADS)

    Kong, D. L.; Lü, X. T.; Jiang, L. L.; Wu, H. F.; Miao, Y.; Kardol, P.

    2013-08-01

    Water availability has profound effects on plant growth and productivity in temperate and semi-arid grasslands. However, it remains unclear how variation of inter-annual precipitation by extreme rainfall events will alter the aboveground and belowground responses of plants, and how these responses may be contingent on N availability. In this study, we examined the interactive effects of inter-annual precipitation variation and N addition on aboveground and live fine root biomass of a semi-arid grassland in northern China for two consecutive years (2007 and 2008). Inter-annual variation in precipitation resulting mainly from the occurrence of extreme rainfall events in 2008 significantly affected above- and belowground plant biomass responses to water addition. In addition, variation of inter-annual precipitation by this extreme rainfall event suppressed plant responses to nitrogen addition and reduced the interaction effects between water and nitrogen addition. These effects of inter-annual precipitation fluctuation could be attributed to the negative influence of the extreme rainfall event on soil N and water availability, ultimately reducing plant rainfall use efficiency and nitrogen use efficiency. In conclusion, our results suggest ecosystem responses to water and N enrichment could be altered by inter-annual variation of precipitation regime caused by the naturally occurring extreme rainfall events.

  7. Hydrological niche separation explains seasonal and inter-annual variations of vegetation dynamics in seasonally dry tropical forests

    NASA Astrophysics Data System (ADS)

    Xu, X.; Medvigy, D.; Powers, J. S.; Becknell, J. M.; Guan, K.

    2015-12-01

    Despite ample water supply, vegetation dynamics are subject to seasonal water stress in large fraction of tropical forests. These seasonally dry tropical forests (SDTFs) account for over 40% of tropical forests, harbor high biodiversity, have large potential carbon sink due to forest recovery from human disturbance and also play a critical role in global carbon budget and inter-annual variations. Plants in this biome display notably diverse responses to seasonal and inter-annual variations of water availability, especially inter-specific variations in canopy seasonality and biomass growth. Current process-based dynamic vegetation models cannot represent these diversities and are shown to perform poorly on simulating drought responses of tropical forests, calling into question of their ability to accurately simulate future changes in SDTFs. Accumulated field observations, suggest that hydrological niche separation driven by coordinated plant functional traits is associated with plants' performance under drought. Yet, it remains not clear whether the physiology-level hydrological niche separation can explain the ecosystem-level diversity observed in SDTFs. Here, we test the theory with a model-data fusion approach. We implemented a new plant hydrodynamic module that is able to track leaf water potential at sub-daily scale in ED2 model. We further incorporated a hydrological niche separation scheme based on a meta-data analysis of key functional traits in SDTFs. Simulated ecological patterns with and without hydrological niche separation were then compared with remote-sensing and long-term field observations from an SDTF site in Palo Verde, Costa Rica. Using several numerical experiments, we specifically examine the following questions: (i) Whether hydrological niche separation can explain the diversity in canopy seasonality and biomass growth? (ii) How important are the yet uncertain belowground functional traits, especially root profile in determining canopy

  8. Inter-annual Variability of Aboveground Net Primary Productivity in Regenerating Tropical Dry Forests

    NASA Astrophysics Data System (ADS)

    Powers, J. S.; Becknell, J. M.

    2015-12-01

    Globally, there are now more secondary forests regenerating following anthropogenic disturbance than primary forests. However, carbon dynamics in secondary tropical forests in general, and seasonally dry forests in particular, have not been as well studied as primary wet forests. Young, regenerating forests may be more sensitive to climatic variability than older forests because of their dynamic demographic rates. Similarly, seasonally dry tropical forests may be particularly sensitive to changes in precipitation, as tree growth is highly constrained by water availability. We examined how inter-annual variability in precipitation affected above-ground net primary productivity in chronosequences of dry forest in Costa Rica. Our sites included three forest cover types, whose distribution is linked to edaphic variation. Over our 6-yr dataset, annual rainfall varied from 1110 to 3040mm, with a 5-6 month dry season. ANPP ranged from 2.96 to 18.98 Mg ha-1 across sites that have been recovering for 7 to 67 years. Fine litter production dominated ANPP, and increased with forest age but not annual rainfall. By contrast, woody stem growth did not vary among forests that differed in age, but increased as a function of annual rainfall. These results differed by forest type. Lowland oak forests on low fertility soil had the lowest productivity and responses to rainfall, whereas forests on the highest fertility soils showed large increases in woody production with rainfall. Consistent with our expectation, younger forests on the intermediate soil type had higher variability in ANPP than older forests, but this was not significant for forests on the poor or high fertility soils. Our results highlight several important findings: 1) different components of ANPP vary in their responses to inter-annual variation in rainfall, 2) forest responses to climatic variability depend on species composition, which varies consistently with soil type in this landscape.

  9. Twenty Years of High-Resolution Sea Surface Temperature Imagery around Australia: Inter-Annual and Annual Variability

    PubMed Central

    Foster, Scott D.; Griffin, David A.; Dunstan, Piers K.

    2014-01-01

    The physical climate defines a significant portion of the habitats in which biological communities and species reside. It is important to quantify these environmental conditions, and how they have changed, as this will inform future efforts to study many natural systems. In this article, we present the results of a statistical summary of the variability in sea surface temperature (SST) time-series data for the waters surrounding Australia, from 1993 to 2013. We partition variation in the SST series into annual trends, inter-annual trends, and a number of components of random variation. We utilise satellite data and validate the statistical summary from these data to summaries of data from long-term monitoring stations and from the global drifter program. The spatially dense results, available as maps from the Australian Oceanographic Data Network's data portal (http://www.cmar.csiro.au/geonetwork/srv/en/metadata.show?id=51805), show clear trends that associate with oceanographic features. Noteworthy oceanographic features include: average warming was greatest off southern West Australia and off eastern Tasmania, where the warming was around 0.6°C per decade for a twenty year study period, and insubstantial warming in areas dominated by the East Australian Current, but this area did exhibit high levels of inter-annual variability (long-term trend increases and decreases but does not increase on average). The results of the analyses can be directly incorporated into (biogeographic) models that explain variation in biological data where both biological and environmental data are on a fine scale. PMID:24988444

  10. Twenty years of high-resolution sea surface temperature imagery around Australia: inter-annual and annual variability.

    PubMed

    Foster, Scott D; Griffin, David A; Dunstan, Piers K

    2014-01-01

    The physical climate defines a significant portion of the habitats in which biological communities and species reside. It is important to quantify these environmental conditions, and how they have changed, as this will inform future efforts to study many natural systems. In this article, we present the results of a statistical summary of the variability in sea surface temperature (SST) time-series data for the waters surrounding Australia, from 1993 to 2013. We partition variation in the SST series into annual trends, inter-annual trends, and a number of components of random variation. We utilise satellite data and validate the statistical summary from these data to summaries of data from long-term monitoring stations and from the global drifter program. The spatially dense results, available as maps from the Australian Oceanographic Data Network's data portal (http://www.cmar.csiro.au/geonetwork/srv/en/metadata.show?id=51805), show clear trends that associate with oceanographic features. Noteworthy oceanographic features include: average warming was greatest off southern West Australia and off eastern Tasmania, where the warming was around 0.6°C per decade for a twenty year study period, and insubstantial warming in areas dominated by the East Australian Current, but this area did exhibit high levels of inter-annual variability (long-term trend increases and decreases but does not increase on average). The results of the analyses can be directly incorporated into (biogeographic) models that explain variation in biological data where both biological and environmental data are on a fine scale.

  11. Trend Change Detection in NDVI Time Series: Effects of Inter-Annual Variability and Methodology

    NASA Technical Reports Server (NTRS)

    Forkel, Matthias; Carvalhais, Nuno; Verbesselt, Jan; Mahecha, Miguel D.; Neigh, Christopher S.R.; Reichstein, Markus

    2013-01-01

    Changing trends in ecosystem productivity can be quantified using satellite observations of Normalized Difference Vegetation Index (NDVI). However, the estimation of trends from NDVI time series differs substantially depending on analyzed satellite dataset, the corresponding spatiotemporal resolution, and the applied statistical method. Here we compare the performance of a wide range of trend estimation methods and demonstrate that performance decreases with increasing inter-annual variability in the NDVI time series. Trend slope estimates based on annual aggregated time series or based on a seasonal-trend model show better performances than methods that remove the seasonal cycle of the time series. A breakpoint detection analysis reveals that an overestimation of breakpoints in NDVI trends can result in wrong or even opposite trend estimates. Based on our results, we give practical recommendations for the application of trend methods on long-term NDVI time series. Particularly, we apply and compare different methods on NDVI time series in Alaska, where both greening and browning trends have been previously observed. Here, the multi-method uncertainty of NDVI trends is quantified through the application of the different trend estimation methods. Our results indicate that greening NDVI trends in Alaska are more spatially and temporally prevalent than browning trends. We also show that detected breakpoints in NDVI trends tend to coincide with large fires. Overall, our analyses demonstrate that seasonal trend methods need to be improved against inter-annual variability to quantify changing trends in ecosystem productivity with higher accuracy.

  12. Seasonal and inter-annual variation in ecosystem scale methane emission from a boreal fen

    NASA Astrophysics Data System (ADS)

    Rinne, Janne; Li, Xuefei; Raivonen, Maarit; Peltola, Olli; Sallantaus, Tapani; Haapanala, Sami; Smolander, Sampo; Alekseychik, Pavel; Aurela, Mika; Korrensalo, Aino; Mammarella, Ivan; Tuittila, Eeva-Stiina; Vesala, Timo

    2016-04-01

    Northern wetlands are one of the major sources of atmospheric methane. We have measured ecosystem scale methane emissions from a boreal fen continuously since 2005. The site is an oligotrophic fen in boreal vegetation zone situated in Siikaneva wetland complex in Southern Finland. The mean annual temperature in the area is 3.3°C and total annual precipitation 710 mm. We have conducted the methane emission measurements by the eddy covariance method. Additionally we have measured fluxes of carbon dioxide, water vapor, and sensible heat together with a suite of other environmental parameters. We have analyzed this data alongside with a model run with University of Helsinki methane model. The measured fluxes show generally highest methane emission in late summers coinciding with the highest temperatures in saturated peat zone. During winters the fluxes show small but detectable emission despite the snow and ice cover on the fen. More than 90% of the annual methane emission occurs in snow-free period. The methane emission and peat temperature are connected in exponential manner in seasonal scales, but methane emission does not show the expected behavior with water table. The lack of water table position dependence also contrasts with the spatial variation across microtopography. There is no systematic variation in sub-diurnal time scale. The general seasonal cycle in methane emission is captured well with the methane model. We will show how well the model reproduces the temperature and water table position dependencies observed. The annual methane emission is typically around 10 gC m-2. This is a significant part of the total carbon exchange between the fen and the atmosphere and about twice the estimated carbon loss by leaching from the fen area. The inter-annual variability in the methane emission is modest. The June-September methane emissions from different years, comprising most of the annual emission, correlates positively with peat temperature, but not with

  13. Inter-annual maintenance of the fine-scale genetic structure in a biennial plant.

    PubMed

    Valverde, Javier; Gómez, José María; García, Cristina; Sharbel, Timothy F; Jiménez, María Noelia; Perfectti, Francisco

    2016-11-24

    Within plant populations, space-restricted gene movement, together with environmental heterogeneity, can result in a spatial variation in gene frequencies. In biennial plants, inter-annual flowering migrants can homogenize gene frequencies between consecutive cohorts. However, the actual impact of these migrants on spatial genetic variation remains unexplored. Here, we used 10 nuclear microsatellite and one plastid genetic marker to characterize the spatial genetic structure within two consecutive cohorts in a population of the biennial plant Erysimum mediohispanicum (Brassicaceae). We explored the maintenance of this structure between consecutive flowering cohorts at different levels of complexity, and investigated landscape effects on gene flow. We found that cohorts were not genetically differentiated and showed a spatial genetic structure defined by a negative genetic-spatial correlation at fine scale that varied in intensity with compass directions. This spatial genetic structure was maintained when comparing plants from different cohorts. Additionally, genotypes were consistently associated with environmental factors such as light availability and soil composition, but to a lesser extent compared with the spatial autocorrelation. We conclude that inter-annual migrants, in combination with limited seed dispersal and environmental heterogeneity, play a major role in shaping and maintaining the spatial genetic structure among cohorts in this biennial plant.

  14. Inter-annual maintenance of the fine-scale genetic structure in a biennial plant

    PubMed Central

    Valverde, Javier; Gómez, José María; García, Cristina; Sharbel, Timothy F.; Jiménez, María Noelia; Perfectti, Francisco

    2016-01-01

    Within plant populations, space-restricted gene movement, together with environmental heterogeneity, can result in a spatial variation in gene frequencies. In biennial plants, inter-annual flowering migrants can homogenize gene frequencies between consecutive cohorts. However, the actual impact of these migrants on spatial genetic variation remains unexplored. Here, we used 10 nuclear microsatellite and one plastid genetic marker to characterize the spatial genetic structure within two consecutive cohorts in a population of the biennial plant Erysimum mediohispanicum (Brassicaceae). We explored the maintenance of this structure between consecutive flowering cohorts at different levels of complexity, and investigated landscape effects on gene flow. We found that cohorts were not genetically differentiated and showed a spatial genetic structure defined by a negative genetic-spatial correlation at fine scale that varied in intensity with compass directions. This spatial genetic structure was maintained when comparing plants from different cohorts. Additionally, genotypes were consistently associated with environmental factors such as light availability and soil composition, but to a lesser extent compared with the spatial autocorrelation. We conclude that inter-annual migrants, in combination with limited seed dispersal and environmental heterogeneity, play a major role in shaping and maintaining the spatial genetic structure among cohorts in this biennial plant. PMID:27883087

  15. Seasonal and inter-annual variability of lower stratospheric age of air spectra

    NASA Astrophysics Data System (ADS)

    Ploeger, Felix; Birner, Thomas

    2016-08-01

    Trace gas transport in the lower stratosphere is investigated by analysing seasonal and inter-annual variations of the age of air spectrum - the probability distribution of stratospheric transit times. Age spectra are obtained using the Chemical Lagrangian Model of the Stratosphere (CLaMS) driven by ERA-Interim winds and total diabatic heating rates, and using a time-evolving boundary-impulse-response (BIER) method based on multiple tracer pulses. Seasonal age spectra show large deviations from an idealized stationary uni-modal shape. Multiple modes emerge in the spectrum throughout the stratosphere, strongest at high latitudes, caused by the interplay of seasonally varying tropical upward mass flux, stratospheric transport barriers and recirculation. Inter-annual variations in transport (e.g. quasi-biennial oscillation) cause significant modulations of the age spectrum shape. In fact, one particular QBO phase may determine the spectrum's mode during the following 2-3 years. Interpretation of the age spectrum in terms of transport contributions due to the residual circulation and mixing is generally not straightforward. It turns out that advection by the residual circulation represents the dominant pathway in the deep tropics and in the winter hemisphere extratropics above 500 K, controlling the modal age in these regions. In contrast, in the summer hemisphere, particularly in the lowermost stratosphere, mixing represents the most probable pathway controlling the modal age.

  16. Thermospheric inter-annual variability and its potential connection to ENSO and stratospheric QBO

    NASA Astrophysics Data System (ADS)

    Liu, Huixin

    2016-05-01

    Using a 46-year-long dataset of the thermospheric density during 1967-2012, we examined the inter-annual variability in the thermosphere at 400 km and its potential connection to El-Nino Southern Oscillation (ENSO) and stratospheric Quasi-Biennial Oscillation (QBO). Wavelet analysis reveals two major modes of the thermosphere inter-annual oscillation, with the slower mode having an average period of ~64 months and the faster mode of ~28 months. The slower mode bears high coherence with the ENSO during 1982-2012, while the faster mode is found to vary coherently with the QBO around 1972, 1982 and 2002. Further examination reveals that the coherence between QBO and the faster mode is significantly influenced by their common coherent variation with the solar flux, while high coherence between the slower mode and ENSO is much less contaminated. Therefore, we conclude that the 28-month periodicity in thermospheric density may be caused by both QBO and solar radiation, whereas the 64-month periodicity possibly arises mainly from ENSO processes, with little/small contribution from solar radiation.

  17. Inter-Annual Variability in Tropical Cirrus Extent Simulated with a Global Chemistry Transport Model

    NASA Astrophysics Data System (ADS)

    Köhler, M. O.; MacKenzie, A. R.; Horseman, A. M.

    2014-12-01

    The extent and variability of cirrus coverage can play an important role for the transport of trace constituents through the tropical tropopause layer into the stratosphere. This is due to direct radiative effects from cirrus clouds, their impact on local water vapour abundances in the UTLS region and due to chemical processes on the surface of ice crystals. We investigate the variability of tropical cirrus cloud coverage over a period of 10 years (2004-2014) and its correlation with the Southern Oscillation Index. We use a global 3D offline chemistry transport model (SLIMCAT-Cirrus), with a parameterization of cirrus clouds formed by homogeneous nucleation. We compare the model's ability to reproduce the inter-annual variability in tropical cirrus extent with remote sensing data from satellites as well as with in-situ observations from the NASA Global Hawk in the Pacific region as part of the ATTREX campaign. Impacts from cirrus on the vertical transport from the troposphere to the stratosphere in the tropics and its inter-annual variability can be diagnosed from the model results.

  18. Inter-annual variation of carbon uptake by a plantation oak woodland in south-eastern England

    NASA Astrophysics Data System (ADS)

    Wilkinson, M.; Eaton, E. L.; Broadmeadow, M. S. J.; Morison, J. I. L.

    2012-07-01

    The carbon balance of an 80 yr old deciduous oak plantation in the temperate oceanic climate of the south-east of Britain was measured by eddy covariance over 12 yr (1999-2010). The mean annual net ecosystem productivity (NEP) was 486 g C m-2 y-1 (95% CI of ±73 g C m-2 y-1), and this was partitioned into a Gross Primary Productivity (GPP) of 2034 ± 145 g C m-2 y-1, over a 165 (±6) day growing season, and an annual loss of carbon through respiration and decomposition (ecosystem respiration, Reco) of 1548 ± 122 g C m-2 y-1. The interannual variation of NEP was large (coefficient of variation (CV) 23%), although the variation for GPP and Reco was smaller (12%) and the ratio of Reco/GPP was relatively constant (0.76 ± 0.02 CI). Some anomalies in the annual patterns of the carbon balance could be linked to particular combinations of anomalous weather events, such as high summer air temperature and low soil moisture content. The Europe-wide heat-wave and drought of 2003 had little effect on the C balance of this woodland on a surface water gley soil. Annual variation in precipitation (CV 18%) was not a main factor in the variation in NEP. The inter-annual variation in estimated intercepted radiation only accounted for ~ 47% of the variation in GPP, although a significant relationship (p<0.001) was found between peak leaf area index and annual GPP which in turn played an important role in modifying the efficiency with which incident radiation was used in net CO2 uptake. Whilst the spring start and late autumn end of the net CO2 uptake period varied substantially (range of 24 and 27 days, respectively), annual GPP was not related to growing season length. Severe outbreaks of defoliating moth caterpillars, mostly Tortrix viridana L. and Operophtera brumata L., caused considerable damage to the forest canopy in 2009 and 2010, resulting in reduced GPP in these years.

  19. Projecting pest population dynamics under global warming: the combined effect of inter- and intra-annual variations.

    PubMed

    Zidon, Royi; Tsueda, Hirotsugu; Morin, Efrat; Morin, Shai

    2016-06-01

    The typical short generation length of insects makes their population dynamics highly sensitive not only to mean annual temperatures but also to their intra-annual variations. To consider the combined effect of both thermal factors under global warming, we propose a modeling framework that links general circulation models (GCMs) with a stochastic weather generator and population dynamics models to predict species population responses to inter- and intra-annual temperature changes. This framework was utilized to explore future changes in populations of Bemisia tabaci, an invasive insect pest-species that affects multiple agricultural systems in the Mediterranean region. We considered three locations representing different pest status and climatic conditions: Montpellier (France), Seville (Spain), and Beit-Jamal (Israel). We produced ensembles of local daily temperature realizations representing current and future (mid-21st century) climatic conditions under two emission scenarios for the three locations. Our simulations predicted a significant increase in the average number of annual generations and in population size, and a significant lengthening of the growing season in all three locations. A negative effect was found only in Seville for the summer season, where future temperatures lead to a reduction in population size. High variability in population size was observed between years with similar annual mean temperatures, suggesting a strong effect of intra-annual temperature variation. Critical periods were from late spring to late summer in Montpellier and from late winter to early summer in Seville and Beit-Jamal. Although our analysis suggested that earlier seasonal activity does not necessarily lead to increased populations load unless an additional generation is produced, it is highly likely that the insect will become a significant pest of open-fields at Mediterranean latitudes above 40° during the next 50 years. Our simulations also implied that current

  20. Identification of Diurnal, Seasonal and Inter-Annual Variability Across SE Asian Field Observations of key Water Cycle Variables: Rainfall, net Radiation, Total Evaporation and River Discharge

    NASA Astrophysics Data System (ADS)

    Solera García, M. A.; Tych, W.; Chappell, N.

    2007-12-01

    The identification of periodic patterns in water cycle variables is critical to the understanding of land-atmosphere interactions, climate change and the evaluation of General Circulation Model (GCM) output. SE Asia in particular plays a very important role on the global climate because it is a large source of energy and water fluxes into the upper atmosphere. Cycle identification is carried out following the Data Based Mechanistic (DBM) philosophy, which focuses on the use of parsimonious, rigorous models which are characterised by lack of a priori assumptions, built in uncertainty analysis and final model acceptance dependent on the physical interpretation of the results. The DBM tool used here is the Unobserved Component - Dynamic Harmonic Regression (UC-DHR) model, which is a statistical method that allows the identification of variability in time series by introducing Time Variable Parameter (TVP) estimation of harmonic components. UC-DHR is not scale dependent and was thus applied to both hourly (to investigate diurnal variation) and fortnightly datasets (for intra- and inter-annual variability). The data used in the analysis has been gathered from existing catchment datasets for three regions of tropical SE Asia, namely Northern Thailand, Central Peninsular Malaysia and Northeast Borneo. These regions were chosen because they represent the hydro-climatic gradient (seasonal to equatorial) present within the tropics and because SE Asia has the most extensive set of catchment/plot studies within the humid tropics. Results show modeling tools were able to quantify the main patterns present in the observations throughout different time scales (diurnal, intra-annual and inter-annual) and the strength of the correlation pattern between the four hydro-climatic variables. The subsequent discussion focuses on the physical processes behind those patterns (e.g. diurnal variability caused by local convection due to solar heating; impact of El Niño Southern Oscillation

  1. Modelling coastal connectivity in a Western Boundary Current: Seasonal and inter-annual variability

    NASA Astrophysics Data System (ADS)

    Roughan, Moninya; Macdonald, Helen S.; Baird, Mark E.; Glasby, Tim M.

    2011-03-01

    Understanding the transport and distribution of marine larvae by ocean currents is one of the key goals of population ecology. Here we investigate circulation in the East Australian Current (EAC) and its impact on the transport of larvae and coastal connectivity. A series of Lagrangian particle trajectory experiments are conducted in summer and winter from 1992-2006 which enables us to investigate seasonal and inter-annual variability. We also estimate a mean connectivity state from the average of each of the individual realisations. Connectivity patterns are related to the movement of five individual larval species (two tropical, two temperate and one invasive species) and are found to be in qualitative agreement with historical distribution patterns found along the coast of SE Australia. We use a configuration of the Princeton Ocean Model to investigate physical processes in the ocean along the coast of SE Australia where the circulation is dominated by the EAC, a vigorous western boundary current. We assimilate hydrographic fields from a ˜10-km global analysis into a ˜3-km resolution continental shelf model to create a high-resolution hindcast of ocean state for each summer and winter from 1992-2006. Particles are released along the coast of SE Australia, and at various isobaths across the shelf (25-1000 m) over timescales ranging from 10-90 days. Upstream of the EAC separation point across-shelf release location dominates the particle trajectory length scales, whereas seasonality dominates in the southern half of the domain, downstream of the separation point. Lagrangian probability density functions show dispersion pathways vary with release latitude, distance offshore and the timescale of dispersion. Northern (southern) release sites are typified by maximum (minimum) dispersal pathways. Offshore release distance also plays a role having the greatest impact at the mid-latitude release sites. Maximum alongshore dispersion occurs at the mid-latitude release

  2. Inter-annual changes of Biomass Burning and Desert Dust and their impact over East Asia

    NASA Astrophysics Data System (ADS)

    DONG, X.; Fu, J. S.; Huang, K.

    2014-12-01

    Impact of mineral dust and biomass burning aerosols on air quality has been well documented in the last few decades, but the knowledge about their interactions with anthropogenic emission and their impacts on regional climate is very limited (IPCC, 2007). While East Asia is greatly affected by dust storms in spring from Taklamakan and Gobi deserts (Huang et al., 2010; Li et al., 2012), it also suffers from significant biomass burning emission from Southeast Asia during the same season. Observations from both surface monitoring and satellite data indicated that mineral dust and biomass burning aerosols may approach to coastal area of East Asia simultaneously, thus have a very unique impact on the local atmospheric environment and regional climate. In this study, we first investigated the inter-annual variations of biomass burning and dust aerosols emission for 5 consecutive years from 2006-2010 to estimate the upper and lower limits and correlation with meteorology conditions, and then evaluate their impacts with a chemical transport system. Our preliminary results indicated that biomass burning has a strong correlation with precipitation over Southeast Asia, which could drive the emission varying from 542 Tg in 2008 to 945 Tg in 2010, according to FLAMBE emission inventory (Reid et al., 2009). Mineral dust also demonstrated a strong dependence on wind filed. These inter-annual/annual variations will also lead to different findings and impacts on air quality in East Asia. Reference: Huang, K., et al. (2010), Mixing of Asian dust with pollution aerosol and the transformation of aerosol components during the dust storm over China in spring 2007, Journal of Geophysical Research-Atmospheres, 115. IPCC (2007), Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, New York. Li, J., et al. (2012), Mixing of Asian mineral dust with anthropogenic pollutants over East Asia: a model case study of a super-duststorm in

  3. Multi-tissue analyses reveal limited inter-annual and seasonal variation in mercury exposure in an Antarctic penguin community.

    PubMed

    Brasso, Rebecka L; Polito, Michael J; Emslie, Steven D

    2014-10-01

    Inter-annual variation in tissue mercury concentrations in birds can result from annual changes in the bioavailability of mercury or shifts in dietary composition and/or trophic level. We investigated potential annual variability in mercury dynamics in the Antarctic marine food web using Pygoscelis penguins as biomonitors. Eggshell membrane, chick down, and adult feathers were collected from three species of sympatrically breeding Pygoscelis penguins during the austral summers of 2006/2007-2010/2011. To evaluate the hypothesis that mercury concentrations in penguins exhibit significant inter-annual variation and to determine the potential source of such variation (dietary or environmental), we compared tissue mercury concentrations with trophic levels as indicated by δ(15)N values from all species and tissues. Overall, no inter-annual variation in mercury was observed in adult feathers suggesting that mercury exposure, on an annual scale, was consistent for Pygoscelis penguins. However, when examining tissues that reflected more discrete time periods (chick down and eggshell membrane) relative to adult feathers, we found some evidence of inter-annual variation in mercury exposure during penguins' pre-breeding and chick rearing periods. Evidence of inter-annual variation in penguin trophic level was also limited suggesting that foraging ecology and environmental factors related to the bioavailability of mercury may provide more explanatory power for mercury exposure compared to trophic level alone. Even so, the variable strength of relationships observed between trophic level and tissue mercury concentrations across and within Pygoscelis penguin species suggest that caution is required when selecting appropriate species and tissue combinations for environmental biomonitoring studies in Antarctica.

  4. Millennium-scale crossdating and inter-annual climate sensitivities of standing California redwoods.

    PubMed

    Carroll, Allyson L; Sillett, Stephen C; Kramer, Russell D

    2014-01-01

    Extremely decay-resistant wood and fire-resistant bark allow California's redwoods to accumulate millennia of annual growth rings that can be useful in biological research. Whereas tree rings of Sequoiadendron giganteum (SEGI) helped formalize the study of dendrochronology and the principle of crossdating, those of Sequoia sempervirens (SESE) have proven much more difficult to decipher, greatly limiting dendroclimatic and other investigations of this species. We overcame these problems by climbing standing trees and coring trunks at multiple heights in 14 old-growth forest locations across California. Overall, we sampled 1,466 series with 483,712 annual rings from 120 trees and were able to crossdate 83% of SESE compared to 99% of SEGI rings. Standard and residual tree-ring chronologies spanning up to 1,685 years for SESE and 1,538 years for SEGI were created for each location to evaluate crossdating and to examine correlations between annual growth and climate. We used monthly values of temperature, precipitation, and drought severity as well as summer cloudiness to quantify potential drivers of inter-annual growth variation over century-long time series at each location. SESE chronologies exhibited a latitudinal gradient of climate sensitivities, contrasting cooler northern rainforests and warmer, drier southern forests. Radial growth increased with decreasing summer cloudiness in northern rainforests and a central SESE location. The strongest dendroclimatic relationship occurred in our southernmost SESE location, where radial growth correlated negatively with dry summer conditions and exhibited responses to historic fires. SEGI chronologies showed negative correlations with June temperature and positive correlations with previous October precipitation. More work is needed to understand quantitative relationships between SEGI radial growth and moisture availability, particularly snowmelt. Tree-ring chronologies developed here for both redwood species have

  5. Millennium-Scale Crossdating and Inter-Annual Climate Sensitivities of Standing California Redwoods

    PubMed Central

    Carroll, Allyson L.; Sillett, Stephen C.; Kramer, Russell D.

    2014-01-01

    Extremely decay-resistant wood and fire-resistant bark allow California’s redwoods to accumulate millennia of annual growth rings that can be useful in biological research. Whereas tree rings of Sequoiadendron giganteum (SEGI) helped formalize the study of dendrochronology and the principle of crossdating, those of Sequoia sempervirens (SESE) have proven much more difficult to decipher, greatly limiting dendroclimatic and other investigations of this species. We overcame these problems by climbing standing trees and coring trunks at multiple heights in 14 old-growth forest locations across California. Overall, we sampled 1,466 series with 483,712 annual rings from 120 trees and were able to crossdate 83% of SESE compared to 99% of SEGI rings. Standard and residual tree-ring chronologies spanning up to 1,685 years for SESE and 1,538 years for SEGI were created for each location to evaluate crossdating and to examine correlations between annual growth and climate. We used monthly values of temperature, precipitation, and drought severity as well as summer cloudiness to quantify potential drivers of inter-annual growth variation over century-long time series at each location. SESE chronologies exhibited a latitudinal gradient of climate sensitivities, contrasting cooler northern rainforests and warmer, drier southern forests. Radial growth increased with decreasing summer cloudiness in northern rainforests and a central SESE location. The strongest dendroclimatic relationship occurred in our southernmost SESE location, where radial growth correlated negatively with dry summer conditions and exhibited responses to historic fires. SEGI chronologies showed negative correlations with June temperature and positive correlations with previous October precipitation. More work is needed to understand quantitative relationships between SEGI radial growth and moisture availability, particularly snowmelt. Tree-ring chronologies developed here for both redwood species have

  6. Immune function in a free-living bird varies over the annual cycle, but seasonal patterns differ between years.

    PubMed

    Hegemann, Arne; Matson, Kevin D; Both, Christiaan; Tieleman, B Irene

    2012-11-01

    A central hypothesis of eco-immunology proposes trade-offs between immune defences and competing physiological and behavioural processes, leading to immunological variation within and among annual-cycle stages, as has been revealed for some species. However, few studies have simultaneously investigated patterns of multiple immune indices over the entire annual cycle in free-living birds, and none has investigated the consistency of seasonal patterns across multiple years. We quantified lysis, agglutination, haptoglobin, leukocyte profiles, and body mass in free-living skylarks (Alauda arvensis) through two complete annual cycles and within and between four breeding seasons. The skylarks' annual cycle is characterised by annually repeated changes in energy and time budgets, social structure and diet. If trade-offs relating to these cyclic changes shape evolution, predictable intra-annual immune patterns may result. Alternatively, intra-annual immune patterns may vary among years if fluctuating environmental changes affect the cost-benefit balances of immune function. We found significant variation in immune indices and body mass across the annual cycle, and these patterns differed between years. Immune parameters differed between four breeding seasons, and in all years, lysis and agglutination increased as the season progressed independent of average levels. Population-level patterns (intra-annual, inter-annual, within breeding season) were consistent with within-individual patterns based on repeated measurements. We found little evidence for sex differences, and only haptoglobin was correlated (negatively) with body mass. We conclude that immune modulation is not simply a pre-programmed phenomenon that reflects predictable ecological changes. Instead, fluctuating environmental conditions that vary among years likely contribute to the immunological variation that we observed.

  7. Growth response of temperate mountain grasslands to inter-annual variations of snow cover duration

    NASA Astrophysics Data System (ADS)

    Choler, P.

    2015-02-01

    A remote sensing approach is used to examine the direct and indirect effects of snow cover duration and weather conditions on the growth response of mountain grasslands located above the tree line in the French Alps. Time-integrated normalized difference vegetation index (NDVIint), used as a surrogate for aboveground primary productivity, and snow cover duration were derived from a 13 year long time series of the Moderate Resolution Imaging Spectro-radiometer (MODIS). A regional-scale meteorological forcing that accounted for topographical effects was provided by the SAFRAN-Crocus-MEPRA model chain. A hierarchical path analysis was developed to analyze the multivariate causal relationships between forcing variables and proxies of primary productivity. Inter-annual variations in primary productivity were primarily governed by year-to-year variations in the length of the snow-free period and to a much lesser extent by temperature and precipitation during the growing season. A prolonged snow cover reduces the number and magnitude of frost events during the initial growth period but this has a negligeable impact on NDVIint as compared to the strong negative effect of a delayed snow melting. The maximum NDVI slightly responded to increased summer precipitation and temperature but the impact on productivity was weak. The period spanning from peak standing biomass to the first snowfall accounted for two thirds of NDVIint and this explained the high sensitivity of NDVIint to autumn temperature and autumn rainfall that control the timing of the first snowfall. The ability of mountain plants to maintain green tissues during the whole snow-free period along with the relatively low responsiveness of peak standing biomass to summer meteorological conditions led to the conclusion that the length of the snow-free period is the primary driver of the inter-annual variations in primary productivity of mountain grasslands.

  8. Growth response of temperate mountain grasslands to inter-annual variations in snow cover duration

    NASA Astrophysics Data System (ADS)

    Choler, P.

    2015-06-01

    A remote sensing approach is used to examine the direct and indirect effects of snow cover duration and weather conditions on the growth response of mountain grasslands located above the tree line in the French Alps. Time-integrated Normalized Difference Vegetation Index (NDVIint), used as a surrogate for aboveground primary productivity, and snow cover duration were derived from a 13-year long time series of the Moderate-resolution Imaging Spectroradiometer (MODIS). A regional-scale meteorological forcing that accounted for topographical effects was provided by the SAFRAN-CROCUS-MEPRA model chain. A hierarchical path analysis was developed to analyze the multivariate causal relationships between forcing variables and proxies of primary productivity. Inter-annual variations in primary productivity were primarily governed by year-to-year variations in the length of the snow-free period and to a much lesser extent by temperature and precipitation during the growing season. A prolonged snow cover reduces the number and magnitude of frost events during the initial growth period but this has a negligible impact on NDVIint as compared to the strong negative effect of a delayed snow melting. The maximum NDVI slightly responded to increased summer precipitation and temperature but the impact on productivity was weak. The period spanning from peak standing biomass to the first snowfall accounted for two-thirds of NDVIint and this explained the high sensitivity of NDVIint to autumn temperature and autumn rainfall that control the timing of the first snowfall. The ability of mountain plants to maintain green tissues during the whole snow-free period along with the relatively low responsiveness of peak standing biomass to summer meteorological conditions led to the conclusion that the length of the snow-free period is the primary driver of the inter-annual variations in primary productivity of mountain grasslands.

  9. Inter- and intra-annual variations of clumping index derived from the MODIS BRDF product

    NASA Astrophysics Data System (ADS)

    He, Liming; Liu, Jane; Chen, Jing M.; Croft, Holly; Wang, Rong; Sprintsin, Michael; Zheng, Ting; Ryu, Youngryel; Pisek, Jan; Gonsamo, Alemu; Deng, Feng; Zhang, Yongqin

    2016-02-01

    Clumping index quantifies the level of foliage aggregation, relative to a random distribution, and is a key structural parameter of plant canopies and is widely used in ecological and meteorological models. In this study, the inter- and intra-annual variations in clumping index values, derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) BRDF product, are investigated at six forest sites, including conifer forests, a mixed deciduous forest and an oak-savanna system. We find that the clumping index displays large seasonal variation, particularly for the deciduous sites, with the magnitude in clumping index values at each site comparable on an intra-annual basis, and the seasonality of clumping index well captured after noise removal. For broadleaved and mixed forest sites, minimum clumping index values are usually found during the season when leaf area index is at its maximum. The magnitude of MODIS clumping index is validated by ground data collected from 17 sites. Validation shows that the MODIS clumping index can explain 75% of variance in measured values (bias = 0.03 and rmse = 0.08), although with a narrower amplitude in variation. This study suggests that the MODIS BRDF product has the potential to produce good seasonal trajectories of clumping index values, but with an improved estimation of background reflectance.

  10. QBO Generated Inter-annual Variations of the Diurnal Tide in the Mesosphere

    NASA Technical Reports Server (NTRS)

    Mayr, Hans G.; Mengel, John G.

    2004-01-01

    We report results from a study with the Numerical Spectral Model (NSM), which produces in the mesosphere significant inter-annual variations in the diurnal tide. Applying Hines Doppler Spread Parameterization (DPS), small-scale gravity waves (GW) drive the Quasi-biennial Oscillation (QBO) and Semi-annual Oscillation (SAO). With a GW source that peaks at the equator and is taken to be isotropic and independent of season, the NSM generates near the equator a QBO with variable periods around 27 months and zonal wind amplitudes close to 20 m / s at 30 Ism. As reported earlier, the NSM reproduces the observed equinoctial maxima in the diurnal tide at altitudes around 95 km. In the present paper it is shown that the QBO modulates the tide such that the seasonal amplitude maxima can vary from one year to another by as much as 30%. Since the period of the QBO is variable, its phase relative to the seasonal cycle changes. The magnitude of the QBO modulation of the tide thus varies considerably as our long-term model simulation shows. To shed light on the underlying mechanism, the relative importance of the linearized advection terms are discussed that involve the meridional and vertical winds of the diurnal tide.

  11. QBO Generated Inter-annual Variations of the Diurnal Tide in the Mesosphere

    NASA Technical Reports Server (NTRS)

    Mayr, Hans G.; Mengel, John G.

    2004-01-01

    We report results from a study with the Numerical Spectral Model (NSM), which produces in the d i d tide significant inter-annual variations. Applying Hines' Doppler Spread Parameterization (DPS), small-scale gravity waves (GW) drive the Quasi-biennial Oscillation (QBO) and Semi-annual Oscillation (SAO). With a GW source that peaks at the equator and is taken to be isotropic and independent of season, the NSM generates a QBO with variable periods around 27 months and zonal wind amplitudes close to 20 m/s at 30 lan, As reported earlier, the NSM reproduces the observed equinoctial maxima in the diurnal tide at altitudes around 95 km. In the present paper it is shown that the QBO modulates the tide such that the seasonal amplitude maxima can vary from one year to another by as much as 30%. Since the period of the QBO is variable, its phase relative to the seasonal cycle changes. The magnitude of the QBO modulation of the tide thus varies considerably as our long-term model simulation shows. To shed light on the underlying mechanisms, we discuss (a) the relative importance of the linearized advection terms that involve the meridional and vertical winds of the diurnal tide and (b) the effects momentum deposition from GWs filtered by the QBO.

  12. Impact of inter-annual climatic variability on ecosystem carbon exchange in two grazed temperate grasslands with contrasting drainage regimes

    NASA Astrophysics Data System (ADS)

    Choncubhair, Órlaith Ní; Humphreys, James; Lanigan, Gary

    2014-05-01

    Temperate grasslands constitute over 30% of the Earth's naturally-occurring biomes and make an important contribution towards the partial mitigation of anthropogenic greenhouse gas emissions by terrestrial ecosystems. Accumulation of carbon (C) in grassland systems predominantly takes place in below-ground repositories, enhanced by the presence of a stable soil environment with low carbon turnover rates, active rhizodeposition and high levels of residue and organic inputs. Predicted future warming is expected to increase productivity in temperate zones, thereby enhancing rates of terrestrial carbon sequestration. However, the susceptibility of many ecosystems, including grasslands, to extreme climatic events and inter-annual variability has been demonstrated previously. Temperature anomalies as well as modifications in the temporal pattern and quantity of precipitation alter the balance between carbon uptake and release processes and a mechanistic understanding of ecosystem response to such changes is still lacking. In the present study, the impact of extreme inter-annual variability in summer rainfall and temperature on carbon dynamics in two rotationally-grazed grasslands in Ireland was examined. The sites experience similar temperate climatic regimes but differ in soil drainage characteristics. Eddy covariance measurements of net ecosystem exchange of carbon were complemented by regular assessment of standing biomass, leaf cover, harvest exports and organic amendment inputs. The summers of 2012 and 2013 showed contrasting climatic conditions, with summer precipitation 93% higher and 25% lower respectively than long-term means. In addition, soil temperatures were 7% lower and 11% higher than expected. Cool, wet conditions in 2012 facilitated net carbon uptake for more than ten months of the year at the poorly-drained site, however the ecosystem switched to a net source of carbon in 2013 during months with significantly reduced rainfall. In contrast, net C

  13. Inter-annual variability of the Mediterranean thermohaline circulation in Med-CORDEX simulations

    NASA Astrophysics Data System (ADS)

    Vittoria Struglia, Maria; Adani, Mario; Carillo, Adriana; Pisacane, Giovanna; Sannino, Gianmaria; Beuvier, Jonathan; Lovato, Tomas; Sevault, Florence; Vervatis, Vassilios

    2016-04-01

    Recent atmospheric reanalysis products, such as ERA40 and ERA-interim, and their regional dynamical downscaling prompted the HyMeX/Med-CORDEX community to perform hind-cast simulations of the Mediterranean Sea, giving the opportunity to evaluate the response of different ocean models to a realistic inter-annual atmospheric forcing. Ocean numerical modeling studies have been steadily improving over the last decade through hind-cast processing, and are complementary to observations in studying the relative importance of the mechanisms playing a role in ocean variability, either external forcing or internal ocean variability. This work presents a review and an inter-comparison of the most recent hind-cast simulations of the Mediterranean Sea Circulation, produced in the framework of the Med-CORDEX initiative, at resolutions spanning from 1/8° to 1/16°. The richness of the simulations available for this study is exploited to address the effects of increasing resolution, both of models and forcing, the initialization procedure, and the prescription of the atmospheric boundary conditions, which are particularly relevant in order to model a realistic THC, in the perspective of fully coupled regional ocean-atmosphere models. The mean circulation is well reproduced by all the simulations. However, it can be observed that the horizontal resolution of both atmospheric forcing and ocean model plays a fundamental role in the reproduction of some specific features of both sub-basins and important differences can be observed among low and high resolution atmosphere forcing. We analyze the mean circulation on both the long-term and decadal time scale, and the represented inter-annual variability of intermediate and deep water mass formation processes in both the Eastern and Western sub-basins, finding that models agree with observations in correspondence of specific events, such as the 1992-1993 Eastern Mediterranean Transient, and the 2005-2006 event in the Gulf of Lion. Long

  14. Annual snowpack patterns across the Rockies: Long-term trends and associated 500-mb synoptic patterns

    SciTech Connect

    Changnon, D. ); McKee, T.B.; Doesken, N.J. )

    1993-03-01

    Winter snowpack was investigated to determine spatial and temporal climate variability in a five-state region (Colorado, Idaho, Montana, Utah, and Wyoming) in the northern Rocky Mountains, covering the period 1951-1985. Annual 1 April snowpack (SN) measurements were selected for analyses. Three basic and persistent patterns of annual SN values surfaced: years with a consistent anomaly over the entire region (wet or dry); years with a distinct north-to-south gradient; and average years. Nearly 90% of the nonaverage annual SN patterns were explained by the frequency of seven 500-mb winter synoptic patterns. The wet-north-dry-south gradient SN patterns occurred only before 1974, and the dry-north-wet-south gradient southern areas of the five-state region are due to periods when one of the two north-to-south gradient SN patterns occurred and are explained by the changes in the frequency of synoptic patterns. 20 refs., 19 figs., 6 tabs.

  15. Inter-provincial migration in Spain: temporal trends and age-specific patterns.

    PubMed

    Garcia Coll, A; Stillwell, J

    1999-01-01

    "This paper provides interpretation of the changing patterns of internal migration in Spain at the inter-provincial scale, and new analysis of age-specific migration during the 1980s using a 10% sample of anonymised records from the 1991 census. Schedules of age-specific gross migration rates are constructed and classified according to their shape and level relative to the national schedule, and the relationships between in-migration and out-migration rates are examined for four selected age groups to demonstrate how aggregate patterns of inter-provincial migration conceal a wide diversity of age specific experience."

  16. Seasonal and inter-annual turbidity variability in the Río de la Plata from 15 years of MODIS: El Niño dilution effect

    NASA Astrophysics Data System (ADS)

    Dogliotti, A. I.; Ruddick, K.; Guerrero, R.

    2016-12-01

    Spatio-temporal variability of turbidity in the Río de la Plata (RdP) estuary (Argentina) at seasonal and inter-annual timescales is analyzed from 15 years (2000-2014) of MODIS data and explained in terms of river discharges and the El Niño Southern Oscillation (ENSO). Satellite estimates were first validated using in situ turbidity measurements and then the time series of monthly averages were analyzed to assess the seasonal and inter-annual variability of turbidity. A strong seasonal variability was found in the upper and middle estuary with high turbidity from March to May and low turbidity from June to January. It was found that this variability is highly correlated to the seasonal cycle of the water discharge of the Bermejo river with a one-month delay between its peak and turbidity in the upper RdP estuary. On inter-annual time scales the influence of ENSO shows low turbidity amplitudes in the upper and middle estuary during moderate El Niño years, while the opposite pattern is observed in some La Niña years. A dilution effect during El Niño years is observed given that the main tributaries, which provide ∼92% of the liquid discharge, show water discharge increases due to excess in rain, while the Bermejo river, which provides ∼70% of the solid discharge and only 2% of the liquid discharge to the RdP, does not show this inter-decadal periodicity. In turn, increased turbidities are observed when negative RdP water discharge anomalies occurred, but this is not always related to La Niña events, since these events are not the only predictor for drought in this region.

  17. East Asian Monsoon controls on the inter-annual variability in precipitation isotope ratio in Japan

    NASA Astrophysics Data System (ADS)

    Kurita, N.; Fujiyoshi, Y.; Nakayama, T.; Matsumi, Y.; Kitagawa, H.

    2015-02-01

    To elucidate the mechanism for how the East Asian Monsoon (EAM) variability have influenced the isotope proxy records in Japan, we explore the primary driver of variations of precipitation isotopes at multiple temporal scales (event, seasonal and inter-annual scales). Using a new 1-year record of the isotopic composition of event-based precipitation and continuous near-surface water vapor at Nagoya in central Japan, we identify the key atmospheric processes controlling the storm-to-storm isotopic variations through an analysis of air mass sources and rainout history during the transport of moisture to the site, and then apply the identified processes to explain the inter-annual isotopic variability related to the EAM variability in the historical 17-year long Tokyo station record in the Global Network of Isotopes in Precipitation (GNIP). In the summer, southerly flows transport moisture with higher isotopic values from subtropical marine regions and bring warm rainfall enriched with heavy isotopes. The weak monsoon summer corresponds to enriched isotopic values in precipitation, reflecting higher contribution of warm rainfall to the total summer precipitation. In the strong monsoon summer, the sustaining Baiu rainband along the southern coast of Japan prevents moisture transport across Japan, so that the contribution of warm rainfall is reduced. In the winter, storm tracks are the dominant driver of storm-to-storm isotopic variation and relatively low isotopic values occur when a cold frontal rainband associated with extratropical cyclones passes off to the south of the Japan coast. The weak monsoon winter is characterized by lower isotopes in precipitation, due to the distribution of the cyclone tracks away from the southern coast of Japan. In contrast, the northward shift of the cyclone tracks and stronger development of cyclones during the strong monsoon winters decrease the contribution of cold frontal precipitation, resulting in higher isotopic values in

  18. Inter-rater Reliability of Sustained Aberrant Movement Patterns as a Clinical Assessment of Muscular Fatigue

    PubMed Central

    Aerts, Frank; Carrier, Kathy; Alwood, Becky

    2016-01-01

    Background: The assessment of clinical manifestation of muscle fatigue is an effective procedure in establishing therapeutic exercise dose. Few studies have evaluated physical therapist reliability in establishing muscle fatigue through detection of changes in quality of movement patterns in a live setting. Objective: The purpose of this study is to evaluate the inter-rater reliability of physical therapists’ ability to detect altered movement patterns due to muscle fatigue. Design: A reliability study in a live setting with multiple raters. Participants: Forty-four healthy individuals (ages 19-35) were evaluated by six physical therapists in a live setting. Methods: Participants were evaluated by physical therapists for altered movement patterns during resisted shoulder rotation. Each participant completed a total of four tests: right shoulder internal rotation, right shoulder external rotation, left shoulder internal rotation and left shoulder external rotation. Results: For all tests combined, the inter-rater reliability for a single rater scoring ICC (2,1) was .65 (95%, .60, .71) This corresponds to moderate inter-rater reliability between physical therapists. Limitations: The results of this study apply only to healthy participants and therefore cannot be generalized to a symptomatic population. Conclusion: Moderate inter-rater reliability was found between physical therapists in establishing muscle fatigue through the observation of sustained altered movement patterns during dynamic resistive shoulder internal and external rotation. PMID:27347241

  19. Inter-annual to inter-decadal streamflow variability in Quebec and Ontario in relation to dominant large-scale climate indices

    NASA Astrophysics Data System (ADS)

    Nalley, D.; Adamowski, J.; Khalil, B.; Biswas, A.

    2016-05-01

    The impacts of large-scale climate oscillations on hydrological systems and their variability have been documented in different parts of the world. Since hydroclimatic data are known to exhibit non-stationary characteristics, spectral analyses such as wavelet transforms are very useful in extracting time-frequency information from such data. As Canadian studies, particularly those of regions east of the Prairies, using wavelet transform-based methods to draw links between relevant climate indices [e.g., the El Niño Southern Oscillation (ENSO), the North Atlantic Oscillation (NAO), and the Pacific Decadal Oscillation (PDO)] and streamflow variability are not common, this study aims to analyze such relationships for the southern regions of Quebec and Ontario. Monthly and annual streamflow data with a record length of 55 years were used to capture streamflow variability at intra-annual, inter-annual and inter-decadal scales. The continuous wavelet transform spectra of monthly streamflow data revealed consistent significant 6- and 12-month periodicities, which are likely associated with strong seasonality factors. Its annual counterparts showed four different significant periodicities: up to 4 years, 4-6 years, 6-8 years, and greater than 8 years - all of which occurred after the late 1960s/early 1970s. Wavelet coherence analyses show that the influence of ENSO and NAO at the inter-annual scale occurs at 2-6 year periodicities, and the influence of PDO occur at periodicities up to 8 years and exceeding 16 years. Correlations between these climate indices and streamflow were computed to determine the time delay of streamflow response to the influence of ENSO, NAO, and PDO. The lag times ranged from 6-48 months (for monthly data) and 1-4 years (for annual data). This research contributes to our understanding of streamflow variability over the southern parts of Quebec and Ontario, and the role of ENSO, NAO, and PDO phenomena on this variability. These relationships can

  20. Rice Area Inter Annual Variation through a Remote Sensing Based Mapping Algorithm

    NASA Astrophysics Data System (ADS)

    Elshorbagy, A. M.; Imam, E. H.; Nour, M. H.

    2013-10-01

    Rice is the main water-consuming crop planted in Egypt Delta. Constrained with the limited water resources, mapping rice is essential for any better water resources management. Xiao (2005) developed an algorithm for rice mapping by studying the dynamics of three vegetation indices the normalized difference vegetation index (NDVI), the Enhanced Vegetation Index (EVI) and the Land surface water index (LSWI). Rice main differentiating feature is being planted in flooded land. Thus moisture sensitive index like LSWI will temporally exceed the EVI or the NDVI signalling rice transplanting. Xiao (2005) utilized MODIS free satellite imagery (500 m spatial resolution). However its coarse resolution combined with the Egyptian complex landscape raised the need for the algorithm modification. In this piece of work a low - cost rice mapping algorithm was developed. The multi resolution (MODIS 250 m red and near infrared bands) and (MODIS 500 m - shortwave infrared and blue bands) were utilized. The arable land was mapped through the utilization of the NDVI and applying it on MODIS 250 m (fine spatial resolution) scenes. The MODIS fine temporal resolution (MOD09A1 product) was utilized to study the LSWI, NDVI and EVI dynamics throughout the rice planting season. The non-arable land from MODIS 250 m was then used to refine the rice area calculated from the MODIS 500 m imagery. The algorithm was applied on the Egypt delta region in years 2008, 2009, and 2010. The mapped rice areas were enhanced from the MODIS 250 m arable mapping module and the results of the algorithm were validated against annual areas reports. There was good agreement between the estimated areas from the algorithm and the reports. Inter annual variation in rice areas was successfully mapped. In addition, the rice area and probable transplanting dates conforms to local planting practices. The findings of this study indicate that the algorithm can be used for rice mapping on a timely and frequent manner.

  1. Seasonal and inter-annual variability of dissolved inorganic nutrients along the western Antarctic Peninsula: is the Southern Annular Mode a potential driver?

    NASA Astrophysics Data System (ADS)

    Kim, H.; Martinson, D. G.; Iannuzzi, R. A.; Ducklow, H. W.

    2014-12-01

    We investigated long-term time series data to improve our understanding of phytoplankton bloom dynamics and its regulation by climate variability on the western Antarctic Peninsula (wAP). Specifically, we examined seasonal and inter-annual variability in utilization of three major inorganic nutrients (nitrate and nitrite, phosphate, silicate) by spring phytoplankton blooms and potential drivers responsible for shaping those variations, using a 20-year time series (1992-2012) near Palmer Station on the wAP. Seasonal and inter-annual covariability in the 50-m depth integrated nutrients and chlorophyll-a (Chl) was analyzed using principle component analysis. We found no linear trends in any of the nutrients or Chl, but there were strong year-to-year fluctuations in seasonal nutrient drawdown and phytoplankton blooms. On average, Chl peaked around days 290-310, stayed high for ca. 40 days, and gradually decreased to the end of the growing season (March-April). Nitrate and nitrite and phosphate behaved in the opposite way of chl-a indicating biological utilization by phytoplankton, but silicate was not utilized in all years, implying non-diatom blooms. Annual anomalies showed a cyclic pattern in Chl, with a maximum occurring every four to six years on average. These years were found to be associated with the negative phase of the Southern Annular Mode (SAM) in preceding winter. Our results suggest large-scale climate variability as a potential driver of biological utilization of nutrients and phytoplankton blooms.

  2. Inter-Annual and Decadal Changes in Tropospheric and Stratospheric Ozone

    NASA Technical Reports Server (NTRS)

    Ziemke, Jr. R.; Chandra, S.

    2011-01-01

    Ozone data beginning October 2004 from the Aura Ozone Monitoring Instrument (OMI) and Aura Microwave Limb Sounder (MLS) are used to evaluate the accuracy of the Cloud slicing technique in effort to develop long data records of tropospheric and stratospheric ozone and studying their long-term changes. Using this technique, we have produced a 32-year (1979-2010) long record of tropospheric and stratospheric ozone from the combined Total Ozone Mapping Spectrometer (Toms) and OMI. The analyses of these time series suggest that the quasi-biennial oscillation (QBO) is the dominant source of inter-annual changes of 30-40 Dobson Units (DU). Tropospheric ozone also indicates a QBO signal in the peak to peak changes varying from 2 to 7 DU. Decadal changes in global stratospheric ozone indicate a turnaround in ozone loss around mid 1990's with most of these changes occurring in the Northern Hemisphere from the subtropics to high latitudes. The trend results are generally consistent with the prediction of chemistry climate models which include the reduction of ozone destroying substances beginning in the late 1980's mandated by the Montreal Protocol.

  3. Inter- annual variability of water vapor over an equatorial coastal station using Microwave Radiometer observations.

    NASA Astrophysics Data System (ADS)

    Renju, Ramachandran Pillai; Uma, K. N.; Krishna Moorthy, K.; Mathew, Nizy; Raju C, Suresh

    The south-western region of the Indian peninsula is the gateway of Indian summer monsoon. This region experiences continuous monsoon rain for a longer period of about six months from June to November. The amount of water vapor variability is one of the important parameters to study the onset, active and break phases of the monsoon. Keeping this in view, a multi-frequency Microwave Radiometer Profiler (MRP) has been made operational for continuous measurements of water vapor over an equatorial coastal station Thiruvananthapuram (8.5(°) N, 76.9(°) E) since April 2010. The MRP estimated precipitable water vapor (PWV) for different seasons including monsoon periods have been evaluated by comparing with the collocated GPS derived water vapor and radiosonde measurements. The diurnal, seasonal and inter annual variation of water vapor has been studied for the last four years (2010-2013) over this station. The significant diurnal variability of water vapor is found only during the winter and pre-monsoon periods (Dec -April). The vertical distribution of water vapour is studied in order to understand its variability especially during the onset of monsoon. During the building up of south-west monsoon, the specific humidity increases to ˜ 10g/kg in the altitude range of 4-6 km and consistently maintained it throughout the active spells and reduces to below 2g/kg during break spells of monsoon. The instrument details and the results will be presented.

  4. Seasonal and inter-annual variations of community metabolism rates of a Posidonia oceanica seagrass meadow

    NASA Astrophysics Data System (ADS)

    Champenois, W.; Borges, A. V.

    2012-04-01

    We report gross primary production (GPP), community respiration (CR), and net community production (NCP) over Posidonia oceanica meadow at 10 m in Corsica (Bay of Revellata) based on the open water O2 mass balance from a data-set of hourly measurements with an array of three O2 optodes deployed from August 2006 to October 2009. The method was checked by comparison with discrete measurements of metabolic rates derived from benthic chamber incubations also based on the diel change of O2. This comparison was satisfactory and actually highlights the potential caveats of benthic incubation measurements related to O2 accumulation in small chambers leading to photorespiration, and an under-estimation of GPP. Our data confirmed previous P. oceanica meadows GPP and CR values, strong seasonal variations, and net autotrophy. High resolution data revealed strong inter-annual variability, with a decrease of GPP by 35% and NCP by 87% during 2006-2007 characterized by a mild and less stormy winter compared 2007-2008 and 2008-2009. P. oceanica meadows are then expected to decrease export of organic carbon to adjacent communities (decrease of NCP), since a decrease in frequency and intensity of marine storms is expected in future in the Mediterranean Sea, due to a northward shift of the Atlantic storm track.

  5. Inter-annual variations of CO2 observed by commercial airliner in the CONTRAIL project

    NASA Astrophysics Data System (ADS)

    Sawa, Yousuke; Machida, Toshinobu; Matsueda, Hidekazu; Niwa, Yosuke; Umezawa, Taku

    2016-04-01

    Since 2005, we have conducted an observation program for greenhouse gases using the passenger aircraft of the Japan Airlines named Comprehensive Observation Network for TRace gases by AIrLiner (CONTRAIL). Over the past 10 years, successful operation of Continuous CO2 Measuring Equipment (CME) has delivered more than 6 million in-situ CO2 data from about 12000 flights between Japan and Europe, Australia, North America, or Asia. The large number of CME data enable us to well characterize spatial distributions and seasonal changes of CO2 in wide regions of the globe especially the Asia-Pacific regions. While the mean growth rates for the past 10 years were about 2 ppm/year, large growth rates of about 3 ppm/year were found in the wide latitudinal bands from 30S to 70N from the second half of 2012 to the first half of 2013. The multiyear data sets have the potential to help understand the global/regional CO2 budget. One good example is the significant inter-annual difference in CO2 vertical profiles observed over Singapore between October 2014 and October 2015, which is attributable to the massive biomass burnings in Indonesia in 2015.

  6. Global and regional methane budget and its inter-annual variability

    NASA Astrophysics Data System (ADS)

    Bourakkadi, Zakia; Payan, Sébastien; Locatelli, Robin; Chevallier, Frederic; Saunois, Marielle; Bousquet, Philippe

    2016-04-01

    Methane global concentration has more than doubled since the pre-industrial times. This increase is generally caused by the anthropogenic activities like the massive use and extraction of fossil fuel, rice paddies agriculture and emissions from landfills. Space observations are very useful to monitor and quantify methane concentration in the atmosphere, in order to improve our knowledge of its sources, sinks, transport and trends. Since 2002 global methane total-columns mixing ratois from the SCanning Imaging Absorption spectroMeter for Atmospheric ChartographY (SCIAMACHY) on board ENVISAT was the first space-borne sensitive to methane in the boundary layer. However the communication with the instrument was lost in April 2012. Since January 2009 methane columns retrievals have been available also from the Thermal And Near Infrared Sensor for carbon Observations-Fourier Transform Spectrometer (TANSO-FTS), on-board the GOSAT satellite. In this study, we used measurements in the short wave infrared radiation (SWIR) from TANSO-FTS covering 5 years, from January 2010 to December 2014 to estimate global methane fluxes by inverse modeling, using the PYVAR-LMDZ model. We present here the results of global and regional methane budget, and its inter-annual variability during this period.

  7. Asynchrony in the inter-annual recruitment of lake whitefish Coregonus clupeaformis in the Great Lakes region

    USGS Publications Warehouse

    Zischke, Mitchell T.; Bunnell, David; Troy, Cary D.; Berglund, Eric K.; Caroffino, David C.; Ebener, Mark P.; He, Ji X.; Sitar, Shawn P.; Hook, Tomas O.

    2017-01-01

    Spatially separated fish populations may display synchrony in annual recruitment if the factors that drive recruitment success, particularly abiotic factors such as temperature, are synchronised across broad spatial scales. We examined inter-annual variation in recruitment among lake whitefish (Coregonus clupeaformis) populations in lakes Huron, Michigan and Superior using fishery-dependent and -independent data from 1971 to 2014. Relative year-class strength (RYCS) was calculated from catch-curve residuals for each year class across multiple sampling years. Pairwise comparison of RYCS among datasets revealed no significant associations either within or between lakes, suggesting that recruitment of lake whitefish is spatially asynchronous. There was no consistent correlation between pairwise agreement and the distance between datasets, and models to estimate the spatial scale of recruitment synchrony did not fit well to these data. This suggests that inter-annual recruitment variation of lake whitefish is asynchronous across broad spatial scales in the Great Lakes. While our method primarily evaluated year-to-year recruitment variation, it is plausible that recruitment of lake whitefish varies at coarser temporal scales (e.g. decadal). Nonetheless, our findings differ from research on some other Coregonus species and suggest that local biotic or density-dependent factors may contribute strongly to lake whitefish recruitment rather than inter-annual variability in broad-scale abiotic factors.

  8. Micro-phytoplankton community structure in the coastal upwelling zone off Concepción (central Chile): Annual and inter-annual fluctuations in a highly dynamic environment

    NASA Astrophysics Data System (ADS)

    Anabalón, V.; Morales, C. E.; González, H. E.; Menschel, E.; Schneider, W.; Hormazabal, S.; Valencia, L.; Escribano, R.

    2016-12-01

    An intensification of upwelling-favorable winds in recent decades has been detected in some of the main eastern boundary current systems, especially at higher latitudes, but the response of coastal phytoplankton communities in the Humboldt Current System (HCS) remains unknown. At higher latitudes in the HCS (35-40°S), strong seasonality in wind-driven upwelling during spring-summer coincides with an annual increase in coastal chlorophyll-a and primary production, and a dominance of micro-phytoplankton. In order to understand the effects of potential upwelling intensification on the micro-phytoplankton community in this region, annual and inter-annual variability in its structure (total and taxa-specific abundance and biomass) and its association with oceanographic fluctuations were analyzed using in situ time series data (2002-2009) from a shelf station off Concepcion (36.5°S). At the annual scale, total mean abundance and biomass, attributed to a few dominant diatom taxa, were at least one order of magnitude greater during spring-summer than autumn-winter, in association with changes in upwelling and surface salinity and temperature, whereas macro-nutrient concentrations remained relatively high all the year. At the inter-annual scale, total abundance and biomass decreased during the upwelling season of the 2006-2009 period compared with the 2002-2006 period, notably due to lower abundances of Skeletonema and Leptocylindrus, but the relative dominance of a few taxa was maintained. The 2006-2009 period was characterized by higher upwelling intensity, colder and higher salinity waters, and changes in nutrient concentrations and ratios compared with the first period. The inter-annual changes in the micro-phytoplankton community were mostly associated with changes in surface salinity and temperature (changes in upwelling intensity) but also with changes in Si/N and N/P, which relate to other land-derived processes.

  9. Seasonal and inter-annual variation of mesozooplankton in the coastal upwelling zone off central-southern Chile

    NASA Astrophysics Data System (ADS)

    Escribano, Ruben; Hidalgo, Pamela; González, Humberto; Giesecke, Ricardo; Riquelme-Bugueño, Ramiro; Manríquez, Karen

    2007-11-01

    Zooplankton sampling at Station 18 off Concepción (36°30‧S and 73°07‧W), on an average frequency of 30 days (August 2002 to December 2005), allowed the assessment of seasonal and inter-annual variation in zooplankton biomass, its C and N content, and the community structure in relation to upwelling variability. Copepods contributed 79% of the total zooplankton community and were mostly represented by Paracalanus parvus, Oithona similis, Oithona nana, Calanus chilensis, and Rhincalanus nasutus. Other copepod species, euphausiids (mainly Euphausia mucronata), gelatinous zooplankton, and crustacean larvae comprised the rest of the community. Changes in the depth of the upper boundary of the oxygen minimum zone indicated the strongly seasonal upwelling pattern. The bulk of zooplankton biomass and total copepod abundance were both strongly and positively associated with a shallow (<20 m) oxygen minimum zone; these values increased in spring/summer, when upwelling prevailed. Gelatinous zooplankton showed positive abundance anomalies in the spring and winter, whereas euphausiids had no seasonal pattern and a positive anomaly in the fall. The C content and the C/N ratio of zooplankton biomass significantly increased during the spring when chlorophyll- a was high (>5 mg m -3). No major changes in zooplankton biomass and species were found from one year to the next. We concluded that upwelling is the key process modulating variability in zooplankton biomass and its community structure in this zone. The spring/summer increase in zooplankton may be largely the result of the aggregation of dominant copepods within the upwelling region; these may reproduce throughout the year, increasing their C content and C/N ratios given high diatom concentrations.

  10. Inter-individual variability and pattern recognition of surface electromyography in front crawl swimming.

    PubMed

    Martens, Jonas; Daly, Daniel; Deschamps, Kevin; Staes, Filip; Fernandes, Ricardo J

    2016-12-01

    Variability of electromyographic (EMG) recordings is a complex phenomenon rarely examined in swimming. Our purposes were to investigate inter-individual variability in muscle activation patterns during front crawl swimming and assess if there were clusters of sub patterns present. Bilateral muscle activity of rectus abdominis (RA) and deltoideus medialis (DM) was recorded using wireless surface EMG in 15 adult male competitive swimmers. The amplitude of the median EMG trial of six upper arm movement cycles was used for the inter-individual variability assessment, quantified with the coefficient of variation, coefficient of quartile variation, the variance ratio and mean deviation. Key features were selected based on qualitative and quantitative classification strategies to enter in a k-means cluster analysis to examine the presence of strong sub patterns. Such strong sub patterns were found when clustering in two, three and four clusters. Inter-individual variability in a group of highly skilled swimmers was higher compared to other cyclic movements which is in contrast to what has been reported in the previous 50years of EMG research in swimming. This leads to the conclusion that coaches should be careful in using overall reference EMG information to enhance the individual swimming technique of their athletes.

  11. Modeling the Observed QBO and Inter-Annual Variations of the Diurnal Tide in the Mesosphere

    NASA Technical Reports Server (NTRS)

    Mayr, Hans G.; Mengel, John G.; Huang, F. T.

    2006-01-01

    In the current version of the Numerical Spectral Model (NSM), the Quasi-biennial Oscillation (QBO) is generated primarily by small-scale gravity waves (GW) from Hines' Doppler Spread Parameterization (DSP). The model does not have topography, and the planetary waves are solely generated by instabilities. We discuss a 3D modeling study that describes the QBO extending from the stratosphere into the upper mesosphere, where the oscillation produces significant inter-annual variations in the diurnal tide. The numerical results are compared with temperature measurements from the SABER (TIMED) and MLS (UARS) instruments obtained by Huang et al. (2006). With a GW source that peaks at the Equator and is taken to be isotropic and independent of season, the NSM generates a QBO with variable periods around 26 months and zonal wind amplitudes of almost 25 m/s at 30 km. As reported earlier, the NSM reproduces the observed equinoctial maxima in the diurnal tide at altitudes around 95 km. The modeled QBO modulates the tide such that the seasonal amplitude maxima can vary from one year to another by as much as 30%. To shed light on the underlying mechanisms, the relative importance of the advection terms are discussed, and they are shown to be important in the stratosphere. At altitudes above 80 km, however, the QBO-related inter-annual variations of the tide are generated primarily by GW momentum deposition. In qualitative agreement with the SABER measurements, the model generates distinct zonal-mean QBO temperature variations in the stratosphere and mesosphere. In the stratosphere, the computed amplitudes are not much smaller than those observed, and the rate of downward propagation at the Equator is reproduced. The modeled temperature amplitudes in the mesosphere, however, are much smaller than those observed. The observed and computed temperature variations of the QBO peak at the Equator but extend with phase reversals to high latitudes, in contrast to the zonal winds that are

  12. Evaluation of two GCMs in simulating rainfall inter-annual variability over Southern Africa

    NASA Astrophysics Data System (ADS)

    Klutse, Nana Ama Browne; Abiodun, Babatunde J.; Hewitson, Bruce C.; Gutowski, William J.; Tadross, Mark A.

    2016-02-01

    We evaluate the performance of two global circulation models (GCMs) over Southern Africa, as part of the efforts to improve the skill of seasonal forecast from a multi-model ensemble system over the region. The two GCMs evaluated in the study are the Community Atmosphere Model version 3 (CAM3) and the Hadley Centre Atmospheric Model version 3 (HadAM3). The study analyzed 30-year climate simulations from the models and compared the results with those from Climate Research Unit (CRU) and National Center for Environmental Prediction (NCEP) reanalysis dataset. The evaluation focused on how well the models simulate circulation features, seasonal variation of temperature and rainfall, and the inter-annual rainfall and circulations during El Niño Southern Oscillation (ENSO) years. The study also investigated the relationship between the regional rainfall from the models and global sea surface temperature (SST) during the El Niño and La Niña years. The results show that both GCMs simulate the circulation features and the seasonal cycles of rainfall and temperature fairly well. The location and magnitude of maxima and minima in surface temperature, sea level pressure (SLP), and rainfall fields are well reproduced. The maximum error in the simulated temperature fields is about 2 °, 4 mb in SLP and 8 mm/day in rainfall. However, CAM3 shows a major bias in simulating the summer rainfall; it simulates the maximum rainfall along the western part of Southern Africa, instead of the eastern part. The phase of the seasonal cycles is well reproduced, but the amplitude is underestimated over the Western Cape. Both CAM3 and HadAM3 give reasonable simulations of significant relationship between the regional rainfall and SST over the Nino 3.4 region and show that ENSO strongly drives the climate of Southern Africa. Hence, the model simulations could contribute to understanding the climate of the region and improve seasonal forecasts over Southern Africa.

  13. Spatio-temporal variation of methane over Indian region: Seasonal and inter-annual variation .

    NASA Astrophysics Data System (ADS)

    M, K.; Nair, P. R.

    2015-12-01

    Methane (CH4) has an important role in the radiation budget and chemistry in the lower and middle atmosphere as a greenhouse and reactive trace gas. The rapid developments in the agriculture and industry over India have lead to the emission of many pollutants like CO, O3, CH4, CO2, SO2 etc into the atmosphere. However, their sources, sinks and concentration levels are poorly understood because of the lack of systematic sampling and monitoring. The advent of satellite remote sensing has helped to analyze the chemical composition of atmosphere with good spatial coverage especially over tropical region which was poorly sampled with the existing surface network. This work attempts an analysis of spatial distribution, seasonal cycle and inter annual variation of CH4 over Indian region during 2003-2009 using SCIAMACHY data onboard ENVISAT. Column CH4 varies from 1740-1890 ppbv over Indian region with distinct spatial and temporal features. We observed a dependence of seasonal CH4 variation on rice cultivation, convective activities and changes in boundary layer characteristics. The comparative study using satellite, aircraft and surface measurement shown CH4 has non-homogeneity in its distribution and seasonal variation in different layers of atmosphere. A comparative study of CH4 at different hot spot regions over the globe was carried out which showed prominent hemispherical variations. Large spread in column CH4 was observed at India and Chinese region compared to other regions with a significant seasonal variability. This study points to the blending of satellite, aircraft and surface measurements for the realization of regional distribution of CH4.

  14. Study of the inter-annual ozone variation at European high latitudes

    NASA Astrophysics Data System (ADS)

    Werner, Rolf; Hoppe, Ulf-Peter; Kivi, Rigel; Stebel, Kerstin; Hansen, Georg; Gausa, Michael; von der Gathen, Peter; Orsolini, Yvan

    The study of the inter-annual ozone variation is based on data sets of the Arctic Lidar Observation of Middle Atmosphere Research (ALOMAR) (69.3° N, 16.0° E,) station at Andenes and of the stations at Sodankyl¨ (67.4° N, 26.6° E) and at Ny-Alesund (78.9° N, 11.9° E). The a data sets cover the time period from 1994 up to 2004. Additionally, the results are completed by HALOE minor gas profiles. We find a second ozone maximum near 13 -15 km, between the tropopause and the absolute ozone maximum near 17- 20 km. The maximum is built up by the combination of air mass transport and chemical ozone destruction, mainly caused by the NOx catalytic cycle, which begins after the polar night and intensifies with the increasing day length. Together with the stratospheric warming during the summer the vertical air mass transport reduces. The descent of ozone from higher to lower altitudes weakens compared to the winter period. The formation of a troposphere inversion layer is observed. The temperature inversion is stronger during the summer period and inhibits the vertical stratosphere troposphere exchange. The horizontal advection in the upper troposphere and lower stratosphere is enforced during the summer, too. The combination of these mechanisms produces a layer with a very low ozone density above the troposphere inversion layer from June/July up to the late autumn. The ozone and temperature distributions obtained from the several arctic stations are compared and the differences are discussed.

  15. Inter-annual variability in spring abundance of adult Calanus finmarchicus from the overwintering population in the southeastern Norwegian Sea

    NASA Astrophysics Data System (ADS)

    Dupont, Nicolas; Bagøien, Espen; Melle, Webjørn

    2017-03-01

    Calanus finmarchicus is the dominant copepod species in the Norwegian Sea, where it plays a key role in the ecosystem by transferring energy from primary producers to higher trophic levels. This paper analyses a 17-year time series, 1996-2012, on C. finmarchicus collected within the Atlantic Water mass along the Svinøy transect in the southeastern Norwegian Sea. We use the spring abundance of adult as a proxy for the size of C. finmarchicus' overwintered population. The inter-annual trend in spring abundance of adult C. finmarchicus in the 200-0 m depth-stratum is assessed while accounting for spring population development to the adult stage represented by day of year for sampling, inter-annual changes in timing of population development, and spatial differences. For the most oceanic stations, a significant inter-annual trend in spring abundance of adult C. finmarchicus was revealed using generalized additive models (GAM). This trend primarily consists in an increase prior to year 2000 and a decrease between years 2000 and ca. 2011. For the stations closer to the coast, the identified inter-annual trend is a decrease during a longer period from the late 90s until ca. 2011. From 2000 to 2011, our estimates suggest a 50% decrease for the most oceanic stations, and as much as an 81% decrease for the stations closer to the coast. In addition the results suggest a consistent change in phenology over the years and the stations. The predicted spring peak of overwintered adult population abundance is suggested to become shorter by 3 days, and the predicted maximum of abundance to take place 4 days earlier over the 17 years of the time-series. The results highlight significant changes in intensity and timing of the overwintered population of a key zooplankton species in the Norwegian Sea that may have important implications on the scale of an entire ecosystem.

  16. Diurnal, Seasonal and Inter-annual Variations of N2O Fluxes from Perennial Vineyard Soils in California, USA.

    NASA Astrophysics Data System (ADS)

    Suddick, E. C.; Carlisle, E. A.; Spencer, R. G.; Smart, D. R.

    2007-12-01

    The USA emits 1562 million metric tons of carbon equivalents a year, whereby this value is projected to rise by an estimated 14 % in 2012. California is the 12th major global emitter of greenhouse gases, emitting approximately 500 million metric tons of carbon equivalents a year. 84 % of greenhouse gas emissions are from CO2, 7 % and 6 % from N2O and CH4 respectively and approximately 8 % of these emissions are derived from agricultural activities. The concentration of nitrous oxide (N2O) within the atmosphere has been increasing at a rate of approximately 0.27 % per year and has mainly been attributed to agricultural practices such as land-use changes, biomass burning, nitrogen fertilization, livestock and manure management. Agriculture related activities generate from 6 to 35 Tg N2O-N per year, or about 60 to 70 % of global production. The primary biogenic sources of N2O are from terrestrial soils, which are thought to be a major source of N2O to the atmosphere and mainly involve the microbial nitrogen transformations brought about by nitrification and denitrification. The aim of this study was to quantify the seasonal and inter-annual variability of N2O emissions and nitrogen cycling from a conventionally tilled wine grape vineyard in Napa, California during a two year closed static chamber study and to also investigate the diurnal N2O flux pattern and effects of fertilization management practices on emissions within a table grape vineyard in Delano, California. Preliminary data shows that the annual N2O fluxes were influenced by soil properties, management practices and weather such as precipitation events where increases in N2O emissions were observed after irrigation or fertilization practices and immediately following rainfall. Vineyard floor and vine management will be discussed in terms of the significance management practices have upon the release of N2O emissions from vineyard soils where the high water and nitrogen fertilizer usage within these

  17. Phenological controls on inter-annual variability in ozone dry deposition velocity

    NASA Astrophysics Data System (ADS)

    Clifton, Olivia; Fiore, Arlene; Munger, J. William; Shevliakova, Elena; Horowitz, Larry; Malyshev, Sergey; Griffin, Kevin

    2016-04-01

    Our understanding of ozone removal by northern mid-latitude temperate deciduous forests is largely based on short-term observational studies, and thus year-to-year variations of this sink have received little attention. The specific pathways for ozone dry deposition include stomatal uptake and other non-stomatal processes that are poorly understood. Given the importance of ozone dry deposition to model accurately the tropospheric ozone budget and regional air quality, an improved mechanistic understanding of this ozone sink is needed. We investigate here the physical and biological controls on inter-annual variations in seasonal and diurnal cycles of ozone dry deposition velocity using nine years of hourly observations of eddy covariance ozone flux and concentration measurements at Harvard Forest, a northern mid-latitude temperate deciduous forest. We also use coincident eddy covariance water vapor flux and sensible heat flux and other micrometeorological measurements to infer stomatal conductance in order to separate the impacts of stomatal versus non-stomatal pathways on ozone deposition. There is a difference of approximately a factor of two between minimum and maximum monthly daytime mean ozone dry deposition velocities at Harvard Forest. The highest summertime mean ozone dry deposition velocities occur during 1998 and 1999 (0.72 cm/s), and similar seasonal and diurnal cycles occur in both years. The similar dry deposition velocities during these two years, however, may reflect compensation between different processes as mean daytime summertime stomatal conductance during 1998 is roughly 1.5 times higher than for 1999, suggesting large year-to-year variations in non-stomatal as well as stomatal uptake of ozone. We partition the onset and decline of the growing season each year into different periods using spring and fall phenology observations at Harvard Forest. Combining the dry deposition velocities across years during each phenological period, we find that

  18. The influence of inter-annually varying albedo on regional climate and drought

    NASA Astrophysics Data System (ADS)

    Meng, X. H.; Evans, J. P.; McCabe, M. F.

    2014-02-01

    strengthening of the second mechanism. That is, the second mechanism is stronger in a drought year compared to a normal year and this difference is larger than for the first mechanism. When both mechanisms are active, the second mechanism tends to dominate across the model domain, particularly during the 2002 drought period. The introduction of observed inter-annual variations in albedo produces an enhancement of the first mechanism and a weakening of the second mechanism during the onset of the drought.

  19. The influence of inter-annually varying albedo on regional climate and drought

    NASA Astrophysics Data System (ADS)

    Meng, X. H.; Evans, J. P.; McCabe, M. F.

    2013-05-01

    strengthening of the second mechanism. That is, the second mechanism is stronger in a drought year compared to a normal year and this difference is larger than for the first mechanism. When both mechanisms are active, the second mechanism tends to dominate across the model domain, particularly during the 2002 drought period. The introduction of observed inter-annual variations in albedo produces an enhancement of the first mechanism and a weakening of the second mechanism during the onset of the drought.

  20. Graph-Based Inter-Subject Pattern Analysis of fMRI Data

    PubMed Central

    Takerkart, Sylvain; Auzias, Guillaume; Thirion, Bertrand; Ralaivola, Liva

    2014-01-01

    In brain imaging, solving learning problems in multi-subjects settings is difficult because of the differences that exist across individuals. Here we introduce a novel classification framework based on group-invariant graphical representations, allowing to overcome the inter-subject variability present in functional magnetic resonance imaging (fMRI) data and to perform multivariate pattern analysis across subjects. Our contribution is twofold: first, we propose an unsupervised representation learning scheme that encodes all relevant characteristics of distributed fMRI patterns into attributed graphs; second, we introduce a custom-designed graph kernel that exploits all these characteristics and makes it possible to perform supervised learning (here, classification) directly in graph space. The well-foundedness of our technique and the robustness of the performance to the parameter setting are demonstrated through inter-subject classification experiments conducted on both artificial data and a real fMRI experiment aimed at characterizing local cortical representations. Our results show that our framework produces accurate inter-subject predictions and that it outperforms a wide range of state-of-the-art vector- and parcel-based classification methods. Moreover, the genericity of our method makes it is easily adaptable to a wide range of potential applications. The dataset used in this study and an implementation of our framework are available at http://dx.doi.org/10.6084/m9.figshare.1086317. PMID:25127129

  1. Inter-Annual Repeatability of Regional Dust Storms During the Martian Dusty Season (Invited)

    NASA Astrophysics Data System (ADS)

    Kass, D. M.; Kleinboehl, A.; McCleese, D. J.; Schofield, J. T.; Smith, M. D.

    2013-12-01

    We investigate the annual pattern of large (regional) dust storms during the martian dusty season--southern spring and summer (Ls 180° to 360°)--and find a repeatable pattern of three distinct storms each Mars year without a global dust storm. We use a 200 K contour in the zonal mean climatology at 50 Pa from TES/MGS and MCS/MRO to identify the regional and global dust storms and then to characterize their extent and evolution. Observations from the two instruments cover the dusty season of five mars years without a global storm: MY24, MY26, MY29, MY30 and MY31. The exact timing, duration and peak temperatures vary somewhat from year to year, but each of the three storms has distinct characteristics and behavior, and overall the years follow a very similar pattern. Each year starts with an 'A' storm pre-perihelion (between Ls 210° and 240°) in the southern mid-latitudes. It lasts for 15° to 40° of Ls and ends no later than the solstice. The storm takes 2° to 12° of Ls to reach its peak zonal mean temperatures between 210 K and 230 K. The second storm ('B' storm) each year occurs as the 'A' storm is decaying. It starts around the perihelion along the southern seasonal polar cap edge and lasts until between Ls 285° and 295°. While the storm often has the strongest warming for the year (with zonal mean peak temperatures between 210 K and 225 K), the storm's impact remains south of the tropics. The final storm each year ('C' storm) starts between Ls 305° and 320°. It lasts a relatively short 3° to 15° of Ls. However, the later the storm starts seasonally, the longer it tends to last. The peak temperatures are quite variable for the 'C' storm, ranging from 200 K to 225 K. In MY26, the 'C' storm has the highest zonal mean temperatures for the season.

  2. Intra- and Inter-annual Fluorescence Intensity Variations in Drip Water, Heshang Cave, Central China: Implications for Speleothem Palaeoclimatology

    NASA Astrophysics Data System (ADS)

    Jin, L.; Hu, C.; Li, X.; Ruan, J.; Hartland, A.

    2015-12-01

    Cave drip water acts as a signal carrier for the soil-rock-air system leading to the capture of climatic and environmental information in stalagmites. This paper seeks to develop an understanding of the environmental and climatic factors which control fluorescence variations in dripwater from in Heshang Cave, Central China. This information is essential to unravelling the significance of organic fluorescence in stalagmites and its utility in quantitative paleoclimate reconstructions. On the seasonal time scale, drip water fluorescence is largely controlled by the decomposition and translocation of dissolved organic matter in the soil, related to climate factors like temperature and precipitation. On the inter-annual time scale, longer duration monitoring data in scarce, yet this is needed to fully comprehend the influence of climate in stalagmite fluorescence time series. This study presents nine consecutive years of monthly drip water fluorescence intensity and drip rate data from two perennial drip sites in Heshang Cave. Drip water fluorescence was generally characterized by intensities in spring/summer and low intensities in autumn/winter. In dry hydrologic years, little seasonality in fluorescence signals was observed, but the opposite was observed in wet years. On the inter-annual time scale, the annual mean intensities of drip water fluorescence positively correlated with local annual rainfall with a 1-year lag (R2HS4=0.94; R2HS6=0.74). This indicates that rainfall is the main control on total drip water fluorescence (integrating across a hydrologic year), despite significant degrees of intra-annual fluorescence variation being observed between wet and dry years. These findings are of direct relevance for paleoclimate reconstruction using fluorescence intensities in stalagmites from the Asian monsoon region. Key words: fluorescence; dissolved organic matter; drip water rates; seasonality; precipitation

  3. Statistical adjustment of simulated inter-annual variability in an investigation of short-term temperature trend distributions over Canada

    NASA Astrophysics Data System (ADS)

    Grenier, Patrick; Chaumont, Diane; de Elía, Ramón

    2015-04-01

    Plausible climate trajectories towards warmer temperatures are made up of a succession of positive and negative short-term trends. Cooling trends over short durations (~ 5 to 25 years) are thus to be expected, and related probabilities have to rely on simulations from physically-based climate models. However, because simulations often present offsets in many statistical properties relative to observations, it is important to address the issue of statistical adjustment prior to characterizing expected short-term trend distributions. In this paper, we discuss the impact of statistically adjusting inter-annual variability on short-term cooling probability for locations across Canada and during the current period (2006-2035). Two methods are considered, one that uses a transfer function based on the dissimilarity between simulated and observed detrended annual temperature values (residuals) during a calibration period, and another that uses an autoregressive model of the observational residuals for generating variability. Long-term trends remain invariant in both methods. Results show that although short-term trends in individual simulations are in some cases highly impacted, cooling probabilities based on a multi-model ensemble are only slightly altered by each of the two methods, due to compensational effects. In summary, this paper presents an application where final results are robust to how simulated inter-annual variability is handled.

  4. Modeling Inter-annual Variability of Seasonal Evaporation and Storage Change Based on the Extended Budyko Framework

    NASA Astrophysics Data System (ADS)

    Chen, X.; Alimohammadi, N.; Wang, D.

    2013-12-01

    Long-term climate is the first order control on mean annual water balance, and vegetation and the interactions between climate seasonality and soil water storage change have also been found to play important roles. The purpose of this paper is to extend the Budyko hypothesis to the seasonal scale and to develop a model for inter-annual variability of seasonal evaporation and storage change. A seasonal aridity index is defined as the ratio of potential evaporation to effective precipitation, where effective precipitation is the difference between rainfall and storage change. Correspondingly, evaporation ratio is defined as the ratio of evaporation to effective precipitation. A modified Turc-Pike equation with a horizontal shift is proposed to model inter-annual variability of seasonal evaporation ratio as a function of seasonal aridity index, which includes rainfall seasonality and soil water change. The performance of the seasonal water balance model is evaluated for 277 watersheds in the United States. 99% of wet seasons and 90% of dry seasons have Nash-Sutcliffe efficiency coefficients larger than 0.5. The developed seasonal model can be applied for constructing long-term evaporation and storage change data when rainfall, potential evaporation, and runoff observations are available. On the other hand, vegetation affects seasonal water balance by controlling both evaporation and soil moisture dynamics. The correlation between NDVI and evaporation is strong particularly in wet seasons. However, the correlation between NDVI and the seasonal model parameters is only strong in dry seasons.

  5. Response of Riparian Vegetation in Australia's Largest River Basin to Inter and Intra-Annual Climate Variability and Flooding as Quantified with Landsat and MODIS

    NASA Astrophysics Data System (ADS)

    Broich, M.; Tulbure, M. G.

    2015-12-01

    Australia is a continent subject to high rainfall variability, which has major influences on runoff and vegetation dynamics. However, the resulting spatial-temporal pattern of flooding and its influence on riparian vegetation has not been quantified in a spatially explicit way. Here we focused on the floodplains of the entire Murray-Darling Basin (MDB), an area that covers over 1M km^2, as a case study. The MDB is the country's primary agricultural area with scarce water resources subject to competing demands and impacted by climate change and more recently by the Millennium Drought (1999-2009). Riparian vegetation in the MDB floodplain suffered extensive decline providing a dramatic degradation of riparian vegetation. We quantified the spatial-temporal impact of rainfall, temperature and flooding patters on vegetation dynamics at the sub- continental to local scales and across inter to intra-annual time scales based on three decades of Landsat (25k images), Bureau of Meteorology data and one decade of MODIS data. Vegetation response varied in space and time and with vegetation types, densities and location relative to areas frequently flooded. Vegetation degradation trends were observed over riparian forests and woodlands in areas where flooding regimes have changed to less frequent and smaller inundation extents. Conversely, herbaceous vegetation phenology followed primarily a 'boom' and 'bust' cycle, related to inter-annual rainfall variability. Spatial patters of vegetation degradation changed along the N-S rainfall gradient but flooding regimes and vegetation degradation patterns also varied at finer scale, highlighting the importance of a spatially explicit, internally consistent analysis and setting the stage for investigating further cross-scale relationships. Results are of interest for land and water management decisions. The approach developed here can be applied to other areas globally such as the Nile river basin and Okavango River delta in Africa or

  6. Response of Riparian Vegetation in AUSTRALIA"S Largest River Basin to Inter and Intra-Annual Climate Variability and Flooding as Quantified with Landsat and Modis

    NASA Astrophysics Data System (ADS)

    Broich, M.; Tulbure, M. G.

    2016-06-01

    Australia is a continent subject to high rainfall variability, which has major influences on runoff and vegetation dynamics. However, the resulting spatial-temporal pattern of flooding and its influence on riparian vegetation has not been quantified in a spatially explicit way. Here we focused on the floodplains of the entire Murray-Darling Basin (MDB), an area that covers over 1M km2, as a case study. The MDB is the country's primary agricultural area with scarce water resources subject to competing demands and impacted by climate change and more recently by the Millennium Drought (1999-2009). Riparian vegetation in the MDB floodplain suffered extensive decline providing a dramatic degradation of riparian vegetation. We quantified the spatial-temporal impact of rainfall, temperature and flooding patters on vegetation dynamics at the subcontinental to local scales and across inter to intra-annual time scales based on three decades of Landsat (25k images), Bureau of Meteorology data and one decade of MODIS data. Vegetation response varied in space and time and with vegetation types, densities and location relative to areas frequently flooded. Vegetation degradation trends were observed over riparian forests and woodlands in areas where flooding regimes have changed to less frequent and smaller inundation extents. Conversely, herbaceous vegetation phenology followed primarily a `boom' and `bust' cycle, related to inter-annual rainfall variability. Spatial patters of vegetation degradation changed along the N-S rainfall gradient but flooding regimes and vegetation degradation patterns also varied at finer scale, highlighting the importance of a spatially explicit, internally consistent analysis and setting the stage for investigating further cross-scale relationships. Results are of interest for land and water management decisions. The approach developed here can be applied to other areas globally such as the Nile river basin and Okavango River delta in Africa or the

  7. Temperature drives inter-annual variability of growing season CO2 and CH4 fluxes of Siberian lowland tundra

    NASA Astrophysics Data System (ADS)

    Kutzbach, Lars; Wille, Christian; Runkle, Benjamin; Schreiber, Peter; Sachs, Torsten; Langer, Moritz; Boike, Julia; Pfeiffer, Eva-Maria

    2015-04-01

    Due to the logistic and technical difficulties associated with experimental work in high latitudes, long-term measurements of CO2 and CH4 fluxes from arctic ecosystems are still rare, and published trace gas balances often rely on measurements from one or few growing seasons. The inter-annual variability of environmental conditions such as temperature, precipitation, snow cover, and timing of snow melt can be high in the Arctic, especially for regions which are influenced by both continental and maritime climates, such as the Siberian arctic lowlands. For these ecosystems, we must also expect a great inter-annual variability in the balance of trace gases. Multi-annual data sets are needed to investigate this variability and its drivers. Here we present multi-annual late summer CO2 and CH4 flux data from the Lena River Delta in the Siberian Arctic (72° N, 126° E). The study site Samoylov Island is characterized by polygonal lowland tundra, a vegetation dominated by mosses and sedges, a soil complex of Glacic, Turbic and Histic Cryosols, and an active layer depth of on average 0.5 m. Seasonal flux measurements were carried out with the eddy covariance technique during the 13-year period 2002 - 2014. Within this period, CO2 flux data overlaps during 37 days (20 July - 25 August) for 12 years, and CH4 flux data overlaps during 25 days (28 July - 21 August) for 9 years. Cumulative net ecosystem CO2 exchange (NEE) during the late summer overlap period is fairly consistent for 9 out of 12 years with a CO2 uptake of 1.9 ± 0.1 mol m-2. Three years show a clearly smaller uptake of

  8. Seasonal and Inter-annual Variation in Wood Production in Tropical Trees on Barro Colorado Island, Panama, is Related to Local Climate and Species Functional Traits

    NASA Astrophysics Data System (ADS)

    Cushman, K.; Muller-Landau, H. C.; Kellner, J. R.; Wright, S. J.; Condit, R.; Detto, M.; Tribble, C. M.

    2015-12-01

    Tropical forest carbon budgets play a major role in global carbon dynamics, but the responses of tropical forests to current and future inter-annual climatic variation remains highly uncertain. Better predictions of future tropical forest carbon fluxes require an improved understanding of how different species of tropical trees respond to changes in climate at seasonal and inter-annual temporal scales. We installed dendrometer bands on a size-stratified sample of 2000 trees in old growth forest on Barro Colorado Island, Panama, a moist lowland forest that experiences an annual dry season of approximately four months. Tree diameters were measured at the beginning and end of the rainy season since 2008. Additionally, we recorded the canopy illumination level, canopy intactness, and liana coverage of all trees during each census. We used linear mixed-effects models to evaluate how tree growth was related to seasonal and interannual variation in local climate, tree condition, and species identity, and how species identity effects related to tree functional traits. Climatic variables considered included precipitation, solar radiation, soil moisture, and climatological water deficit, and were all calculated from high-quality on-site measurements. Functional traits considered included wood density, maximum adult stature, deciduousness, and drought tolerance. We found that annual wood production was positively related to water availability, with higher growth in wetter years. Species varied in their response to seasonal water availability, with some species showing more pronounced reduction of growth during the dry season when water availability is limited. Interspecific variation in seasonal and interannual growth patterns was related to life-history strategies and species functional traits. The finding of higher growth in wetter years is consistent with previous tree ring studies conducted on a small subset of species with reliable annual rings. Together with previous

  9. An Inter-Annual Oscillation in the Western Arctic Associated with a Non Stationary Seasonally Lagged ENSO Signal

    NASA Astrophysics Data System (ADS)

    Moore, Kent; Pickart, Robert

    2015-04-01

    The late summer retreat of Arctic sea ice is one of the most dramatic and well-documented changes that has occurred in the climate system. This retreat is most pronounced in the western Arctic. Sea ice minima in this region are typically followed by years with substantially higher extents. For example, the September 2013 Arctic sea ice extent was ~30% higher than the 2012 minimum. These rebounds have caused confusion amongst the public as well as debate within the scientific and policy communities regarding this aspect of climate change. Here we demonstrate the existence of an inter-annual oscillation in the region that successfully explains the rebound of sea ice following recent minima. The oscillation is associated with local variability in atmospheric flow, including a reversal in the surface wind field, that we propose results in changes in upwelling along the shelf-edge of the Beaufort and Chukchi Seas. From the 1950s to the 1990s, the oscillation was associated with a seasonally lagged El-Nino signal, but this is no longer the case. We argue that this change represents a reduction in the influence that ENSO has on the western Arctic possibly due to the loss of the region's sea ice that has enhanced local inter-annual variability.

  10. Inter-annual changes in detritus-based food chains can enhance plant growth response to elevated atmospheric CO2.

    PubMed

    Hines, Jes; Eisenhauer, Nico; Drake, Bert G

    2015-12-01

    Elevated atmospheric CO2 generally enhances plant growth, but the magnitude of the effects depend, in part, on nutrient availability and plant photosynthetic pathway. Due to their pivotal role in nutrient cycling, changes in abundance of detritivores could influence the effects of elevated atmospheric CO2 on essential ecosystem processes, such as decomposition and primary production. We conducted a field survey and a microcosm experiment to test the influence of changes in detritus-based food chains on litter mass loss and plant growth response to elevated atmospheric CO2 using two wetland plants: a C3 sedge (Scirpus olneyi) and a C4 grass (Spartina patens). Our field study revealed that organism's sensitivity to climate increased with trophic level resulting in strong inter-annual variation in detritus-based food chain length. Our microcosm experiment demonstrated that increased detritivore abundance could not only enhance decomposition rates, but also enhance plant growth of S. olneyi in elevated atmospheric CO2 conditions. In contrast, we found no evidence that changes in the detritus-based food chains influenced the growth of S. patens. Considered together, these results emphasize the importance of approaches that unite traditionally subdivided food web compartments and plant physiological processes to understand inter-annual variation in plant production response to elevated atmospheric CO2.

  11. Inter-annual sea-ice dynamics and micro-algal biomass in winter pack ice of Marguerite Bay, Antarctica

    NASA Astrophysics Data System (ADS)

    Fritsen, Christian H.; Memmott, Jeramie; Stewart, Frank J.

    2008-09-01

    The geographic remoteness, the lack of remote sensing capabilities, and the lack of appropriate environmental sensors make the detection of seasonal trends or inter-annual variations in sea-ice microbial biomass or production processes within the pack ice of the Antarctic extremely rare. The evaluation of their inter-annual variability in the context of ice dynamics and trends in regional climate has not been possible. During the late winters of 2001 (July-August) and 2002 (August-September) we assessed sea-ice dynamics, sea-ice characteristics, and biomass of sea-ice microbiota along the Western Antarctic Peninsula. These two winters were marked by large contrasts in the dates of initial ice formation (late June in 2001 and April in 2002), which resulted in differences in the physical pack-ice characteristics. Chlorophyll a (chl a) content in ice cores differed between the study years, with 2002 having 10-fold higher chl a content. The difference in ice-core chl a content is best explained by the timing of ice formation that leads to less phytoplankton scavenging from the water column and a lack of transfer of solar energy into the pack-ice ecosystem. Such a tractable atmosphere ocean-ice-biota coupling may help in evaluating underlying processes responsible for long-term trends in recruitment cycles of upper trophic levels as well as future projections on the response of the Antarctic marine ecosystems to variability in local climate.

  12. Localised residency and inter-annual fidelity to coastal foraging areas may place sea bass at risk to local depletion

    PubMed Central

    Doyle, Thomas K.; Haberlin, Damien; Clohessy, Jim; Bennison, Ashley; Jessopp, Mark

    2017-01-01

    For many marine migratory fish, comparatively little is known about the movement of individuals rather than the population. Yet, such individual-based movement data is vitally important to understand variability in migratory strategies and fidelity to foraging locations. A case in point is the economically important European sea bass (Dicentrarchus labrax L.) that inhabits coastal waters during the summer months before migrating offshore to spawn and overwinter. Beyond this broad generalisation we have very limited information on the movements of individuals at coastal foraging grounds. We used acoustic telemetry to track the summer movements and seasonal migrations of individual sea bass in a large tidally and estuarine influenced coastal environment. We found that the vast majority of tagged sea bass displayed long-term residency (mean, 167 days) and inter-annual fidelity (93% return rate) to specific areas. We describe individual fish home ranges of 3 km or less, and while fish clearly had core resident areas, there was movement of fish between closely located receivers. The combination of inter-annual fidelity to localised foraging areas makes sea bass very susceptible to local depletion; however, the designation of protected areas for sea bass may go a long way to ensuring the sustainability of this species. PMID:28374772

  13. Inter-annual variability in the biosphere-atmosphere exchange of carbon dioxide and water vapor in adjacent pine and hardwood forests: links to drought, disturbance, and seasonality

    NASA Astrophysics Data System (ADS)

    Novick, K. A.; Ward, E. J.; Oishi, A. C.; Stoy, P. C.

    2012-12-01

    Understanding the variation in long-term biosphere-atmosphere fluxes of carbon dioxide and water vapor is necessary to characterize the benefits and services of terrestrial ecosystems, including the highly productive forests of the Southeastern United States. This study quantifies flux variability at inter-annual times scales using eight-year eddy covariance records from two co-located ecosystems in the Duke Forest (North Carolina, USA): a hardwood deciduous forest (HW) and a pine plantation (PP), which together represent the dominant forest types in the region. When averaged across the study period, annual net ecosystem exchange of CO2 (NEE) was similar in PP and HW (NEE = -560 and -520 g C m-2 y-1 in PP and HW, respectively). Variation in annual NEE was high in both ecosystems, but higher in the pine site (CV = 0.38) as compared to the hardwood site (CV = 0.23). Gross ecosystem productivity (GEP) and ecosystem respiration (RE), which together represent the primary components of NEE, were not necessarily more variable in the pine site; however, the coupling between annual GEP and RE was weaker in PP as compared to HW, contributing to higher overall variability in PP NEE. Our results identify at least two factors contributing to this decoupling: 1) an ice storm event, which reduced PP GEP while increasing or having no effect on PP RE, and 2) two severe drought events, which cause large reductions in PP GEP but not RE. Additionally, in both ecosystems, variability in GEP and NEE is strongly related to the length of the active season (r2 = 0.60 - 0.93), a variable reflecting the seasonality of carbon assimilation that is largely independent from patterns of leaf area development.

  14. Space-time variability of Indonesian rainfall at inter-annual and multi-decadal time scales

    NASA Astrophysics Data System (ADS)

    Yanto; Rajagopalan, Balaji; Zagona, Edith

    2016-11-01

    We investigated the space-time variability of wet (Nov-Apr) and dry (May-Oct) season rainfall over Indonesia, using monthly gridded rainfall data from the University of East Anglia Climatic Research Unit covering the period 1901-2012. Three complimentary techniques were employed—(1) principal component analysis to identify the dominant modes of variability, (2) wavelet spectral analysis to identify the spectral characteristics of the leading modes and their coherence with large scale climate variables and (3) Bayesian Dynamical Linear Model (BDLM) to quantify the temporal variability of the association between rainfall modes and climate variables. In the dry season when the Inter Tropical Convergence Zone (ITCZ) is to the north of the equator the leading two principal components (PCs) explain close to 50 % of the rainfall. In the wet season the ITCZ moves to the south and the leading PCs explain close to 30 % of the variance. El Niño Southern Oscillation (ENSO) is the driver of the leading modes of rainfall variability during both seasons. We find asymmetry in the teleconnections of ENSO to high and low rainfall years in the dry season. Furthermore, ENSO and the leading PCs of rainfall have spectral coherence in the inter-annual band (2-8 years) over the entire period of record and in the multi-decadal (8-16 years) band in post-1980 years. In addition, during the 1950-1980 period the second mode of variability in both seasons has a strong relationship with Pacific Decadal Oscillation. The association between ENSO and the leading mode of Indonesian rainfall has strengthened in recent decades, more so during dry season. These inter-annual and multi-decadal variability of Indonesian rainfall modulated by Pacific climate drivers has implications for rainfall and hydrologic predictability important for water resources management.

  15. Effects of seasonal and inter-annual land cover changes on the hydrology of the Upper Ganges basin, India

    NASA Astrophysics Data System (ADS)

    Tsarouchi, G.; Mijic, A.; Buytaert, W.

    2013-12-01

    In recent decades India has undergone substantial environmental change. The expansion of agricultural land area to meet the demand of a rapidly increasing population and the increasing intensification of groundwater extractions have led to an alarming drop in the water table levels. The recent floods over northern India have raised concerns about how the regional climate variations and human induced changes in landscape are influencing the temporal dynamics of climate-surface-groundwater interactions. Earlier work by the authors developed high-resolution land cover maps for northern India, based on satellite imagery, for the years 1984, 1998 and 2010. These maps were used to drive the distributed version of the land surface model JULES in order to investigate the impact of inter-annual land cover changes in the hydrology of the Upper Ganges (UG) river basin in India. However, JULES in its current version does not simulate crop growth. Since 60% of the study area is occupied by agriculture, the model was improved with routines that allow for dynamic representation of crop growth. The parametrization was done for the two main crops of the UG basin (wheat and rice), allowing for 2 cropping seasons per year. The impact of seasonal and inter-annual land cover changes was investigated by calculating variations in hydrological components such as stream flow, evapotranspiration and soil moisture. The results show that the seasonal cycle is changing a lot when crop growth is taken into account, whereas annual fluxes do not change much. The dynamic coupling of land-surface schemes and crop models is an essential step toward the analysis of future changes of water resources in India caused by climate change, land use change, and potential interactions between both. This is a prerequisite for constructing decision support tools for regional land-use planning and management.

  16. Low Spatial and Inter-Annual Variability in Evaporation from an Intensively Grazed Temperate Pasture System in New Zealand

    NASA Astrophysics Data System (ADS)

    Pronger, J.; Campbell, D.; Clearwater, M.; Rutledge, S.; Wall, A.; Schipper, L. A.

    2015-12-01

    Ecosystem scale measurements of evaporation (E) from intensively managed pasture systems are scarce and are important for informing water resource decision making, drought forecasting, and validation of Earth system models and remote sensing. We measured E from intensively grazed, unirrigated, ryegrass and clover pasture in New Zealand using eddy covariance (EC) for three years (2012 - 2014). Spatial variation in E was less than 3% during the initial study period when up to three sites were operating simultaneously. Inter-annual variability was also less than 3% over the three consecutive years (710 - 730 mm) at one site. The absence of spatial and inter-annul variation largely occurred because E was strongly controlled by net radiation (daytime half-hourly data r2 = 0.83, p < 0.01) which was relatively consistent between sites and years. However, soil moisture decreased surface conductance during seasonal drought constraining E relative to net radiation. Variation in drought severity between years caused variation in seasonal E between years, for example, a relatively severe autumn drought in 2013 reduced E over autumn by 13% compared to 2012. Coincidentally, two unusually large spring and early summer rainfall events during warm conditions later in 2013 increased summer E by 12% compared to 2012 and therefore similar annual totals were measured between years. The FAO56 Penman-Monteith model was able to accurately predict daily E over an annual cycle (r2 = 0.81) to within 5 % of measured cumulative E with a crop factor of 0.96 (determined under non water-limiting conditions) and a water stress coefficient to account for soil moisture restrictions. Intensive grazing events, that remove a large fraction of standing pasture biomass, were found to have no effect on evaporation. The absence of a grazing effect suggests that leaf area was not an important control of E, likely because increases in soil E were able to compensate for decreased transpiration.

  17. Inter- and intra-annual variations of transpiration at a rubber stand in lowland of central Cambodia

    NASA Astrophysics Data System (ADS)

    Kobayashi, Nakako; Kumagai, Tomo'omi; Miyazawa, Yoshiyuki; Matsumoto, Kazuho; Tateishi, Makiko; Tiva, Lim Khan; Mudd, Ryan; Giambelluca, Thomas; Song, Yin

    2013-04-01

    In Southeast Asia, rubber plantation is rapidly expanding, and thus understanding the level of water consumption and tree physiology is a matter of importance to know the impacts on the local hydrology. Intra- and inter-annual variations in transpiration rate (Et) at a rubber stand, growing in lowland of central Cambodia, were examined during two years based on sap flow measurements. As for seasonality, Et was generally large in the rainy season and small in the dry season, showing sharp short-time drop in synchronization with the shedding in late January. Daily stand Et was ~ 2.0 mm day-1 in 2010 and ~ 2.4 mm day-1 in 2011 at the maximum. An analysis of non-linear multiple regression for the canopy conductance (gc) in the two years showed that the stomatal response of rubber trees was well explained by the changes in solar radiation, vapour pressure deficit, soil moisture availability, leaf area, and tree diameter. Sensitivity of gc to the atmospheric drought indicates isohydric behavior of rubber trees, while the same analysis for each year showed possibility of change in leaf characteristics due to tree maturity and/or initiation of latex tapping. The best fit model also predicted relatively small sensitivity of gc to the soil moisture deficit and rapid decrease in gc under extreme drought conditions. Annual stand Et estimated with the gc obtained in the present analysis was 469 mm yr-1 in 2010, while it increased up to 658 mm yr-1 in 2011. To find out the most important environmental variables, we examined the effect of each variable by keeping the others unchanged. This hypothesis analysis showed that in the young rubber stand which were growing very rapidly, inter-annual change of stand Et was determined mainly by the tree growth rate, not by the change of surrounding environments in the air and the soil.

  18. Inter-annual variation in the response of leaf-out onset to soil moisture increase in a teak plantation in northern Thailand.

    PubMed

    Yoshifuji, Natsuko; Igarashi, Yasunori; Tanaka, Nobuaki; Tanaka, Katsunori; Sato, Takanori; Tantasirin, Chatchai; Suzuki, Masakazu

    2014-11-01

    To understand the impact of inter-annual climate change on vegetation-atmosphere mass and energy exchanges, it has become necessary to explore changes in leaf-out onset in response to climatic fluctuations. We examined the response of leaf-out and transpiration onset dates to soil moisture in a teak plantation in northern Thailand based on a 12-year leaf area index and sap flow measurements. The date of leaf-out and transpiration onset varied between years by up to 40 days, and depended on the initial date when the relative extractable water in a soil layer of 0-0.6 m (Θ) was greater than 0.2 being consistent with our previous results. Our new finding is that the delay in leaf-out and transpiration onset relative to the initial date when Θ > 0.2 increases linearly as the initial date on which Θ > 0.2 becomes earlier. The delay spans about 20 days in years when Θ > 0.2 occurs in March (the late dry season)-much earlier than usual because of heavy pre-monsoon rainfalls-while there is little delay in years when Θ > 0.2 occurs in May. This delay indicates the influence of additional factors on leaf-out onset, which controls the delay in the response of leaf-out to soil moisture increase. The results increased our knowledge about the pattern and extent of the changes in leaf phenology that occur in response to the inter-annual climate variation in tropical regions, where, in particular, such research is needed.

  19. Functional patterns in an annual grassland during an AVIRIS overflight

    NASA Technical Reports Server (NTRS)

    Gamon, John A.; Field, Christopher B.; Roberts, Dar A.; Ustin, Susan L.; Valentini, Riccardo

    1993-01-01

    This study relates Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) imagery to ground measurements of vegetation distribution, physiology, and productivity at Stanford University's Jasper Ridge Biological Preserve. Primary efforts focused on a 9-ha region of annual grassland where we completed a detailed ground-based study in conjunction with a 15 May 1991 AVIRIS overflight. Spectral mixture analysis and the normalized difference vegetation index (NDVI) calculated from AVIRIS data were used to evaluate spatial patterns of vegetation type, productivity, and potential physiological activity. Concurrent ground sampling revealed a high degree of correlation between NDVI and estimates of canopy chemistry, structure, productivity, and CO2 flux, supporting the use of imaging spectrometry to estimate spatial and temporal trends in vegetation physiology and productivity in this relatively simple grassland ecosystem. Geostatistical analyses of both ground and AVIRIS data supported the conclusion that the AVIRIS pixel size was suitable for describing the influence of major landscape features in this grassland and that spatial detail would be lost at slightly larger pixel sizes typical of other imaging spectrometers.

  20. CO2 fluxes at northern fens and bogs have opposite responses to inter-annual fluctuations in water table

    NASA Astrophysics Data System (ADS)

    Sulman, Benjamin N.; Desai, Ankur R.; Saliendra, Nicanor Z.; Lafleur, Peter M.; Flanagan, Lawrence B.; Sonnentag, Oliver; Mackay, D. Scott; Barr, Alan G.; van der Kamp, Garth

    2010-10-01

    This study compares eddy-covariance measurements of carbon dioxide fluxes at six northern temperate and boreal peatland sites in Canada and the northern United States of America, representing both bogs and fens. The two peatland types had opposite responses of gross ecosystem photosynthesis (GEP) and ecosystem respiration (ER) to inter-annual fluctuations in water table level. At fens, wetter conditions were correlated with lower GEP and ER, while at bogs wetter conditions were correlated with higher GEP and ER. We hypothesize that these contrasting responses are due to differences in the relative contributions of vascular plants and mosses. The coherence of our results between sites representing a range of average environmental conditions indicates ecosystem-scale differences in resilience to hydrological changes that should be taken into account when considering the future of peatland ecosystem services such as carbon sequestration under changing environmental conditions.

  1. Effects of climatic factors and ecosystem responses on the inter-annual variability of evapotranspiration in a coniferous plantation in subtropical China.

    PubMed

    Xu, Mingjie; Wen, Xuefa; Wang, Huimin; Zhang, Wenjiang; Dai, Xiaoqin; Song, Jie; Wang, Yidong; Fu, Xiaoli; Liu, Yunfen; Sun, Xiaomin; Yu, Guirui

    2014-01-01

    Because evapotranspiration (ET) is the second largest component of the water cycle and a critical process in terrestrial ecosystems, understanding the inter-annual variability of ET is important in the context of global climate change. Eight years of continuous eddy covariance measurements (2003-2010) in a subtropical coniferous plantation were used to investigate the impacts of climatic factors and ecosystem responses on the inter-annual variability of ET. The mean and standard deviation of annual ET for 2003-2010 were 786.9 and 103.4 mm (with a coefficient of variation of 13.1%), respectively. The inter-annual variability of ET was largely created in three periods: March, May-June, and October, which are the transition periods between seasons. A set of look-up table approaches were used to separate the sources of inter-annual variability of ET. The annual ETs were calculated by assuming that (a) both the climate and ecosystem responses among years are variable (Vcli-eco), (b) the climate is variable but the ecosystem responses are constant (Vcli), and (c) the climate is constant but ecosystem responses are variable (Veco). The ETs that were calculated under the above assumptions suggested that the inter-annual variability of ET was dominated by ecosystem responses and that there was a negative interaction between the effects of climate and ecosystem responses. These results suggested that for long-term predictions of water and energy balance in global climate change projections, the ecosystem responses must be taken into account to better constrain the uncertainties associated with estimation.

  2. Seasonal and inter-annual variability of the net ecosystem CO2 exchange of a temperate mountain grassland: effects of climate and management

    PubMed Central

    Wohlfahrt, Georg; Hammerle, Albin; Haslwanter, Alois; Bahn, Michael; Tappeiner, Ulrike; Cernusca, Alexander

    2013-01-01

    The role and relative importance of climate and cutting for the seasonal and inter-annual variability of the net ecosystem CO2 (NEE) of a temperate mountain grassland was investigated. Eddy covariance CO2 flux data and associated measurements of the green area index and the major environmental driving forces acquired during 2001-2006 at the study site Neustift (Austria) were analyzed. Driven by three cutting events per year which kept the investigated grassland in a stage of vigorous growth, the seasonal variability of NEE was primarily modulated by gross primary productivity (GPP). The role of environmental parameters in modulating the seasonal variability of NEE was obscured by the strong response of GPP to changes in the amount of green area, as well as the cutting-mediated decoupling of phenological development and the seasonal course of climate drivers. None of the climate and management metrics examined was able to explain the inter-annual variability of annual NEE. This is thought to result from (1) a high covariance between GPP and ecosystem respiration (Reco) at the annual time scale which results in a comparatively small inter-annual variation of NEE, (2) compensating effects between carbon exchange during and outside the management period, and (3) changes in the biotic response to rather than the climate variables per se. GPP was more important in modulating inter-annual variations in NEE in spring and before the first and second cut, while Reco explained a larger fraction of the inter-annual variability of NEE during the remaining, in particular the post-cut, periods. PMID:24383047

  3. Effects of Climatic Factors and Ecosystem Responses on the Inter-Annual Variability of Evapotranspiration in a Coniferous Plantation in Subtropical China

    PubMed Central

    Xu, Mingjie; Wen, Xuefa; Wang, Huimin; Zhang, Wenjiang; Dai, Xiaoqin; Song, Jie; Wang, Yidong; Fu, Xiaoli; Liu, Yunfen; Sun, Xiaomin; Yu, Guirui

    2014-01-01

    Because evapotranspiration (ET) is the second largest component of the water cycle and a critical process in terrestrial ecosystems, understanding the inter-annual variability of ET is important in the context of global climate change. Eight years of continuous eddy covariance measurements (2003–2010) in a subtropical coniferous plantation were used to investigate the impacts of climatic factors and ecosystem responses on the inter-annual variability of ET. The mean and standard deviation of annual ET for 2003–2010 were 786.9 and 103.4 mm (with a coefficient of variation of 13.1%), respectively. The inter-annual variability of ET was largely created in three periods: March, May–June, and October, which are the transition periods between seasons. A set of look-up table approaches were used to separate the sources of inter-annual variability of ET. The annual ETs were calculated by assuming that (a) both the climate and ecosystem responses among years are variable (Vcli-eco), (b) the climate is variable but the ecosystem responses are constant (Vcli), and (c) the climate is constant but ecosystem responses are variable (Veco). The ETs that were calculated under the above assumptions suggested that the inter-annual variability of ET was dominated by ecosystem responses and that there was a negative interaction between the effects of climate and ecosystem responses. These results suggested that for long-term predictions of water and energy balance in global climate change projections, the ecosystem responses must be taken into account to better constrain the uncertainties associated with estimation. PMID:24465610

  4. Inter-Annual Variability in Stream Water Temperature, Microclimate and Heat Exchanges: a Comparison of Forest and Moorland Environments

    NASA Astrophysics Data System (ADS)

    Garner, G.; Hannah, D. M.; Malcolm, I.; Sadler, J. P.

    2012-12-01

    Riparian forest is recognised as important for moderating stream temperature variability and has the potential to mitigate thermal extremes in a changing climate. Previous research on the heat exchanges controlling water column temperature has often been short-term or seasonally-constrained, with the few multi-year studies limited to a maximum of two years. This study advances previous work by providing a longer-term perspective which allows assessment of inter-annual variability in stream temperature, microclimate and heat exchange dynamics between a semi-natural woodland and a moorland (no trees) reach of the Girnock Burn, a tributary of the Scottish Dee. Automatic weather stations collected 15-minute data over seven consecutive years, which to our knowledge is a unique data set in providing the longest term perspective to date on stream temperature, microclimate and heat exchange processes. Results for spring-summer indicate that the presence of a riparian canopy has a consistent effect between years in reducing the magnitude and variability of mean daily water column temperature and daily net energy totals. Differences in the magnitude and variability in net energy fluxes between the study reaches were driven primarily by fluctuations in net radiation and latent heat fluxes in response to between- and within-year variability in growth of the riparian forest canopy at the forest and prevailing weather conditions at both the forest and moorland. This research provides new insights on the inter-annual variability of stream energy exchanges for moorland and forested reaches under a wide range of climatological and hydrological conditions. The findings therefore provide a more robust process basis for modelling the impact of changes in forest practice and climate change on river thermal dynamics.

  5. Inter-annual rainfall variations and suicide in New South Wales, Australia, 1964-2001

    NASA Astrophysics Data System (ADS)

    Nicholls, Neville; Butler, Colin D.; Hanigan, Ivan

    2006-01-01

    The suicide rate in New South Wales is shown to be related to annual precipitation, supporting a widespread and long-held assumption that drought in Australia increases the likelihood of suicide. The relationship, although statistically significant, is not especially strong and is confounded by strong, long-term variations in the suicide rate not related to precipitation variations. A decrease in precipitation of about 300 mm would lead to an increase in the suicide rate of approximately 8% of the long-term mean suicide rate.

  6. Spatial and inter-annual variability of the macrobenthic communities within a coastal lagoon (Óbidos lagoon) and its relationship with environmental parameters

    NASA Astrophysics Data System (ADS)

    Carvalho, Susana; Moura, Ana; Gaspar, Miguel B.; Pereira, Paula; Cancela da Fonseca, Luís; Falcão, Manuela; Drago, Teresa; Leitão, Francisco; Regala, João

    2005-05-01

    The present work aims to analyse spatial and inter-annual variability in the benthic environment within the Óbidos lagoon, assessing the relationships between environmental characteristics and macrobenthic distribution patterns. Sediment samples were collected in February 2001 and 2002 for the study of macrofauna and biogeochemical parameters (sediment grain size, organic matter, organic carbon, chlorophyll a, and phaeopigments). Comparing 2001 to 2002, a general increase in the number of species, diversity and equitability indices was observed throughout the study area. Likewise, there was an increase of phytopigments and organic matter contents in the upper sediment layer. Based on the macrobenthic community patterns and environmental variables three main areas could be distinguished in both years: an outer area near the inlet mostly influenced by the sea, with very depressed number of species and abundance, and dominated by Saccocirrus papillocercus, Lekanesphaera levii, Microphthalmus similis and Nephtys cirrosa; an intermediate area located in the central part of the lagoon characterized by sandy sediment and low organic carbon, and colonized by a high diverse community with Hydrobia ulvae, Cerastoderma edule and Abra ovata as the most characteristic species; and the innermost area of the lagoon with muddy enriched sediments dominated by Heteromastus filiformis, oligochaetes, Scrobicularia plana, Cyathura carinata, Corophium acherusicum, phoronids, insect larvae and Corbula gibba. Deposit-feeders were dominant in the muddy sediments from the inner area, where suspension-feeders were also abundant. Carnivores were associated with clean sandy sediments from the inlet area and herbivores were more abundant within the central area.

  7. Inter-annual variation in American redstart (Setophaga ruticilla) plumage colour is associated with rainfall and temperature during moult: an 11-year study.

    PubMed

    Reudink, Matthew W; McKellar, Ann E; Marini, Kristen L D; McArthur, Sarah L; Marra, Peter P; Ratcliffe, Laurene M

    2015-05-01

    Carotenoid-based colouration plays an important role in sexual signaling in animals as an honest indicator of individual quality during mate choice and competitive interactions. However, few studies have examined how natural variation in weather conditions influences inter-annual variation in the expression of ornamentation, potentially through affecting the dietary availability of carotenoids. In this study, we examine variation in the expression of carotenoid-based plumage colouration in relation to temperature and rainfall during the pre-moulting and moulting period over 11 years in a population of American redstarts, Setophaga ruticilla, breeding in eastern Canada. We used reflectance spectrometry of tail feathers collected from male and female redstarts to relate feather colour with weather conditions the previous breeding season during the months over which redstarts are likely to moult (June-September). At a population level, birds expressed feathers with higher red chroma and lower brightness in years following high July rainfall and low August temperature. The pattern was stronger in males, but was generally consistent across ages and sexes. Analyses of feathers from repeatedly captured birds indicated that the above patterns could be explained by individual change in feather colour. We suggest that higher rainfall during the moulting period may increase insect abundance and the availability of dietary carotenoids. This is among the first studies to show effects of weather conditions on a sexual signalling trait, which may have important consequences for sexual selection, mate choice, and the reliability of putative signals.

  8. Reconciling intra and inter annual oxygen isotope variability in the White Mountain Bristlecone Pine chronology

    NASA Astrophysics Data System (ADS)

    Berkelhammer, M.; Stott, L. D.

    2008-12-01

    The δ18O of tree-ring cellulose is a function of both the isotopic composition of the soil water and the climatic conditions at the leaf boundary, which affect the magnitude of oxygen isotope fractionations during photosynthesis. Separating the dual-influence of water isotope composition and environmental influences on the final cellulosic product remains a serious challenge in attempts to utilize the cellulosic data for climate reconstructions. In many alpine environments such as the White Mountains of California, the isotopic composition of the soil water pool is established by winter-time precipitation whereas tree growth occurs months later during summer. In this location the δ18O of cellulose has both a winter precipitation influence and a summer environmental influence and the two may vary independently. We utilize 2 isotopic datasets from the White Mountain Bristlecone Pine chronology to argue that the year to year δ18O variations in homogenized whole-ring (early and late wood) cellulose captures the source water (winter) signature while the within-ring isotope variations reflect a systematic response to growing seasonal climate conditions. Thus, by comparing the shape and amplitude of the intra-annual isotope cycle we can distinguish changes in growing season temperature and humidity from year to year or low frequency changes in the isotopic composition of the source water. The intra-annual data for this study utilized over 40 annual growth rings that were sub-sampled at a near-weekly resolution (6-12 samples per ring). We selected wood that grew during the Medieval Climate Anomaly, the Little Ice Age, and an extended drought period at 2ky BP in order to evaluate how growing-season conditions differed between these distinct climatic intervals. The data exhibit a pervasive intra annual cycle whose amplitude and shape remains fairly constant irrespective of the width or the mean isotopic composition of the ring. We are able to generate a similar intra

  9. Inter-Annual Variability of Fledgling Sex Ratio in King Penguins

    PubMed Central

    Viblanc, Vincent A.; Gachot-Neveu, Hélène; Beaugey, Magali; Le Maho, Yvon; Le Bohec, Céline

    2014-01-01

    As the number of breeding pairs depends on the adult sex ratio in a monogamous species with biparental care, investigating sex-ratio variability in natural populations is essential to understand population dynamics. Using 10 years of data (2000–2009) in a seasonally monogamous seabird, the king penguin (Aptenodytes patagonicus), we investigated the annual sex ratio at fledging, and the potential environmental causes for its variation. Over more than 4000 birds, the annual sex ratio at fledging was highly variable (ranging from 44.4% to 58.3% of males), and on average slightly biased towards males (51.6%). Yearly variation in sex-ratio bias was neither related to density within the colony, nor to global or local oceanographic conditions known to affect both the productivity and accessibility of penguin foraging areas. However, rising sea surface temperature coincided with an increase in fledging sex-ratio variability. Fledging sex ratio was also correlated with difference in body condition between male and female fledglings. When more males were produced in a given year, their body condition was higher (and reciprocally), suggesting that parents might adopt a sex-biased allocation strategy depending on yearly environmental conditions and/or that the effect of environmental parameters on chick condition and survival may be sex-dependent. The initial bias in sex ratio observed at the juvenile stage tended to return to 1∶1 equilibrium upon first breeding attempts, as would be expected from Fisher’s classic theory of offspring sex-ratio variation. PMID:25493708

  10. Inter-Sentential Patterns of Code-Switching: A Gender-Based Investigation of Male and Female EFL Teachers

    ERIC Educational Resources Information Center

    Gulzar, Malik Ajmal; Farooq, Muhammad Umar; Umer, Muhammad

    2013-01-01

    This article has sought to contribute to discussions concerning the value of inter-sentential patterns of code-switching (henceforth ISPCS) particularly in the context of EFL classrooms. Through a detailed analysis of recorded data produced in that context, distinctive features in the discourse were discerned which were associated with males' and…

  11. Inter-annual variations of methane emission from an open fen on the Qinghai-Tibetan Plateau: a three-year study.

    PubMed

    Chen, Huai; Wu, Ning; Wang, Yanfen; Zhu, Dan; Zhu, Qiu'an; Yang, Gang; Gao, Yongheng; Fang, Xiuqin; Wang, Xu; Peng, Changhui

    2013-01-01

    The study aimed to understand the inter-annual variations of methane (CH(4)) emissions from an open fen on the Qinghai-Tibetan Plateau (QTP) from 2005 to 2007. The weighted mean CH(4) emission rate was 8.37±11.32 mg CH(4) m(-2 )h(-1) during the summers from 2005 to 2007, falling in the range of CH(4) fluxes reported by other studies, with significant inter-annual and spatial variations. The CH(4) emissions of the year of 2006 (2.11±3.48 mg CH(4) m(-2 )h(-1)) were 82% lower than the mean value of the years 2005 and 2007 (13.91±17.80 mg CH(4) m(-2 )h(-1) and 9.44±14.32 mg CH(4) m(-2 )h(-1), respectively), responding to the inter-annual changes of standing water depths during the growing season of the three years. Significant drawdown of standing water depth is believed to cause such significant reduction in CH(4) emissions from wetlands in the year 2006, probably through changing the methanogen composition and decreasing its community size as well as activating methanotrophs to enhance CH(4) oxidation. Our results are helpful to understand the inter-annual variations of CH(4) emission and provide a more reasonable regional budget of CH(4) emission from wetlands on the QTP and even for world-wide natural wetlands under climate change.

  12. Inter-annual variation of NDVI over Korea Peninsula using harmonic analysis

    NASA Astrophysics Data System (ADS)

    Kim, In-hwan; Han, Kyung-Soo; Pi, Kyoung-Jin; Park, Soo-Jae; Kim, Sang-Il

    2010-10-01

    Global warming and climatic changes due to human activities impact on marine and terrestrial ecosystems, which feedbacks to climate system. These negative feedbacks amplify or accelerate again global climate change. In particular, life cycle of vegetation sensitively vary according to global climate change. This study attempts to analyze quantitatively vegetation change in Korea peninsula using harmonic analysis. Satellite data was extracted from SPOT/VEGETATION S10 MVC (Maximum Value Composite) NDVI (Normalized Difference Vegetation Index) products during 10 years (1999 to 2008) around Korea peninsula. This NDVI data set was pre-processed to correct noise pixels cause by cloud and ground wetness. Variation of vegetation life cycle was analyzed through amplitudes and phases of annual harmonic components (first harmonic components) per year for two land cover types (cropland and forest). The results clearly show that the peak of vegetation life cycle in Korea peninsula is brought forward to early. Especially, it represents that the phases over low latitudes area between 32.8°N and 38°N steadily decrease every year both forest and cropland. The study estimated that phase values moved up approximately 0.5 day per year in cropland and 0.8 day per year in forest.

  13. Inter-annual and seasonal trends in cetacean distribution, density and abundance off southern California

    NASA Astrophysics Data System (ADS)

    Campbell, Gregory S.; Thomas, Len; Whitaker, Katherine; Douglas, Annie B.; Calambokidis, John; Hildebrand, John A.

    2015-02-01

    Trends in cetacean density and distribution off southern California were assessed through visual line-transect surveys during thirty-seven California Cooperative Oceanic Fisheries Investigations (CalCOFI) cruises from July 2004-November 2013. From sightings of the six most commonly encountered cetacean species, seasonal, annual and overall density estimates were calculated. Blue whales (Balaenoptera musculus), fin whales (Balaenoptera physalus) and humpback whales (Megaptera novaeangliae) were the most frequently sighted baleen whales with overall densities of 0.91/1000 km2 (CV=0.27), 2.73/1000 km2 (CV=0.19), and 1.17/1000 km2 (CV=0.21) respectively. Species specific density estimates, stratified by cruise, were analyzed using a generalized additive model to estimate long-term trends and correct for seasonal imbalances. Variances were estimated using a non-parametric bootstrap with one day of effort as the sampling unit. Blue whales were primarily observed during summer and fall while fin and humpback whales were observed year-round with peaks in density during summer and spring respectively. Short-beaked common dolphins (Delphinus delphis), Pacific white-sided dolphins (Lagenorhynchus obliquidens) and Dall's porpoise (Phocoenoidesdalli) were the most frequently encountered small cetaceans with overall densities of 705.83/1000 km2 (CV=0.22), 51.98/1000 km2 (CV=0.27), and 21.37/1000 km2 (CV=0.19) respectively. Seasonally, short-beaked common dolphins were most abundant in winter whereas Pacific white-sided dolphins and Dall's porpoise were most abundant during spring. There were no significant long-term changes in blue whale, fin whale, humpback whale, short-beaked common dolphin or Dall's porpoise densities while Pacific white-sided dolphins exhibited a significant decrease in density across the ten-year study. The results from this study were fundamentally consistent with earlier studies, but provide greater temporal and seasonal resolution.

  14. Inter-annual dynamics of abyssal polychaete communities in the North East Pacific and North East Atlantic—A family-level study

    NASA Astrophysics Data System (ADS)

    Laguionie-Marchais, C.; Billett, D. S. M.; Paterson, G. L. D.; Ruhl, H. A.; Soto, E. H.; Smith, K. L., Jr.; Thatje, S.

    2013-05-01

    Characterising how deep-sea communities change on contemporary time-scales and understanding underlying ecosystem processes has become important under changing climate and the rise in the exploitation of deep-sea resources. However, little is known about these dynamics and processes. Long-term observations from which inter-annual variations can be detected are scarce in the deep sea. This study examines inter-annual changes in density, family richness and evenness, family and functional group rank abundance distributions of infaunal polychaetes at two abyssal stations in the North East Pacific (Station M, 1991 to 2005) and in the North East Atlantic (Porcupine Abyssal Plain, 1991 to 1999). The two long-term data sets were used to investigate not only if polychaete community structure and composition varied at inter-annual scales in terms of diversity and rank abundance distributions but also if any changes were related to previous observations in megafauna and environmental factors at each locality. The polychaete community structure at each locality was analysed using univariate statistics as well as multivariate ordination techniques based on Bray-Curtis similarity of the yearly family density. Sub-surface deposit feeders, such as Paraonidae, dominated the North East Pacific, whereas surface deposit feeders, such as Cirratulidae, dominated the North East Atlantic. Both stations showed inter-annual variations in density, family evenness and rank abundance distributions. The greatest changes occurred in 1998 in both time series when polychaete densities peaked, and switches in the rank abundance of the most abundant families and functional groups took place. Inter-annual variations in the polychaete community were correlated with a limited number of holothurian species changes, but no correlation was found with particulate organic matter flux or climate indices. Ecological and environmental factors behind the family-level changes remain elusive. Overall, changes in

  15. A novel method for diagnosing seasonal to inter-annual surface ocean carbon dynamics from bottle data using neural networks

    NASA Astrophysics Data System (ADS)

    Sasse, T. P.; McNeil, B. I.; Abramowitz, G.

    2013-06-01

    The ocean's role in modulating the observed 1-7 Pg C yr-1 inter-annual variability in atmospheric CO2 growth rate is an important, but poorly constrained process due to current spatio-temporal limitations in ocean carbon measurements. Here, we investigate and develop a non-linear empirical approach to predict inorganic CO2 concentrations (total carbon dioxide (CT) and total alkalinity (AT)) in the global ocean mixed layer from hydrographic properties (temperature, salinity, dissolved oxygen and nutrients). The benefit of this approach is that once the empirical relationship is established, it can be applied to hydrographic datasets that have better spatio-temporal coverage, and therefore provide an additional constraint to diagnose ocean carbon dynamics globally. Previous empirical approaches have employed multiple linear regressions (MLR) and relied on ad hoc geographic and temporal partitioning of carbon data to constrain complex global carbon dynamics in the mixed layer. Synthesizing a new global CT/AT carbon bottle dataset consisting of ~33 000 measurements in the open ocean mixed layer, we develop a neural network based approach to better constrain the non-linear carbon system. The approach classifies features in the global biogeochemical dataset based on their similarity and homogeneity in a self-organizing map (SOM; Kohonen, 1988). After the initial SOM analysis, which includes geographic constraints, we apply a local linear optimizer to the neural network, which considerably enhances the predictive skill of the new approach. We call this new approach SOMLO, or self-organizing multiple linear output. Using independent bottle carbon data, we compare a traditional MLR analysis to our SOMLO approach to capture the spatial CT and AT distributions. We find the SOMLO approach improves predictive skill globally by 19% for CT, with a global capacity to predict CT to within 10.9 μmol kg-1 (9.2 μmol kg-1 for AT). The non-linear SOMLO approach is particularly

  16. Climatic Effects on the Inter-Annual Variability of Carbon Fluxes for North America and Europe

    NASA Astrophysics Data System (ADS)

    Tomelleri, E.; Carvalhais, N.; Migliavacca, M.; Reichstein, M.; Fluxnet Lathuille Synthesis Team (Cf. Www. Fluxdata. Org)

    2010-12-01

    The connection between climate variability and global carbon cycle has already been shown to be linked with the North Atlantic Oscillation (NAO) (1). A positive phase of the NAO is associated with more and stronger winter storms crossing the North Atlantic on a more northerly route, causing major anomalies in sea surface temperature, currents and convective activity throughout the North Atlantic. A long-term trend towards very positive values has culminated in the early 1990s, and since then a decreasing trend is happening (1). Identification of the climatic drivers of the net ecosystem fluxes is becoming a rising issue. In particular the effects of year-to-year climate variability on regional budgets and the understanding of the underlying biogeochemical processes are of fundamental importance due to the intensification of extreme climatic events like precipitation (2) and drought events (3). We identified the relations between climatic variability (i.e. NAO) and the regional carbon budgets of North America and Europe over the period from 1989 to 2008. In doing this we kept special focus both on temporal and spatial scale. For this purpose we took advantage of the high-density of FLUXNET measurement sites in these areas. We applied a radiation use efficiency model for gross primary production (4) combined with a semi-empirical total ecosystem respiration model (5). As drivers for the model we used climatic and fraction of absorbed photosynthetically active radiation (FPAR) records. We utilized in-situ calibrated model parameters to estimate the regional ecosystem carbon fluxes. The model was spatially applied according to the similarity in the climatic-phenological space of each grid pixel with the measurement site to which it was calibrated (e.g., 6). We found that for Europe NAO could explain NEE variability in a reasonable way for northern and southern Europe, but for the mid-latitude region this was not the case. For North America the patterns were less clear

  17. The ScaLIng Macroweather Model (SLIMM) and monthly and inter annual regional forecasting.

    NASA Astrophysics Data System (ADS)

    Lovejoy, S.; Del Rio Amador, L.; Sloman, L.

    2015-12-01

    compare it with actual skill based on hindcasts for monthly, seasonal and annual resolutions. A comparison between our results and previous results using LIM or other GCM's is also shown. The prediction skill obtained for the temperature field have been improved by incorporating some other fields and performing an analogous analysis on the generalized state-vectors.

  18. Uncovering patterns of inter-urban trip and spatial interaction from social media check-in data.

    PubMed

    Liu, Yu; Sui, Zhengwei; Kang, Chaogui; Gao, Yong

    2014-01-01

    The article revisits spatial interaction and distance decay from the perspective of human mobility patterns and spatially-embedded networks based on an empirical data set. We extract nationwide inter-urban movements in China from a check-in data set that covers half a million individuals within 370 cities to analyze the underlying patterns of trips and spatial interactions. By fitting the gravity model, we find that the observed spatial interactions are governed by a power law distance decay effect. The obtained gravity model also closely reproduces the exponential trip displacement distribution. The movement of an individual, however, may not obey the same distance decay effect, leading to an ecological fallacy. We also construct a spatial network where the edge weights denote the interaction strengths. The communities detected from the network are spatially cohesive and roughly consistent with province boundaries. We attribute this pattern to different distance decay parameters between intra-province and inter-province trips.

  19. Uncovering Patterns of Inter-Urban Trip and Spatial Interaction from Social Media Check-In Data

    PubMed Central

    Liu, Yu; Sui, Zhengwei; Kang, Chaogui; Gao, Yong

    2014-01-01

    The article revisits spatial interaction and distance decay from the perspective of human mobility patterns and spatially-embedded networks based on an empirical data set. We extract nationwide inter-urban movements in China from a check-in data set that covers half a million individuals within 370 cities to analyze the underlying patterns of trips and spatial interactions. By fitting the gravity model, we find that the observed spatial interactions are governed by a power law distance decay effect. The obtained gravity model also closely reproduces the exponential trip displacement distribution. The movement of an individual, however, may not obey the same distance decay effect, leading to an ecological fallacy. We also construct a spatial network where the edge weights denote the interaction strengths. The communities detected from the network are spatially cohesive and roughly consistent with province boundaries. We attribute this pattern to different distance decay parameters between intra-province and inter-province trips. PMID:24465849

  20. Inter-annual surface evolution of an Antarctic blue-ice moraine using multi-temporal DEMs

    NASA Astrophysics Data System (ADS)

    Westoby, M. J.; Dunning, S. A.; Woodward, J.; Hein, A. S.; Marrero, S. M.; Winter, K.; Sugden, D. E.

    2015-11-01

    Multi-temporal and fine resolution topographic data products are being increasingly used to quantify surface elevation change in glacial environments. In this study, we employ 3-D digital elevation model (DEM) differencing to quantify the topographic evolution of a blue-ice moraine complex in front of Patriot Hills, Heritage Range, Antarctica. Terrestrial laser scanning (TLS) was used to acquire multiple topographic datasets of the moraine surface at the beginning and end of the austral summer season in 2012/2013 and during a resurvey field campaign in 2014. A complementary topographic dataset was acquired at the end of season 1 through the application of Structure-from-Motion (SfM) photogrammetry to a set of aerial photographs taken from an unmanned aerial vehicle (UAV). Three-dimensional cloud-to-cloud differencing was undertaken using the Multiscale Model to Model Cloud Comparison (M3C2) algorithm. DEM differencing revealed net uplift and lateral movement of the moraine crests within season 1 (mean uplift ∼ 0.10 m), with lowering of a similar magnitude in some inter-moraine depressions and close to the current ice margin. Our results indicate net uplift across the site between seasons 1 and 2 (mean 0.07 m). This research demonstrates that it is possible to detect dynamic surface topographical change across glacial moraines over short (annual to intra-annual) timescales through the acquisition and differencing of fine-resolution topographic datasets. Such data offer new opportunities to understand the process linkages between surface ablation, ice flow, and debris supply within moraine ice.

  1. Inter-annual Controls on Oxygen Isotopes of Precipitaion in the Asian Monsoon Region

    NASA Astrophysics Data System (ADS)

    Yang, H.; Johnson, K. R.; Griffiths, M. L.; Yoshimura, K.

    2015-12-01

    18Op of annual rainfall may be influenced by ENSO and IOD.As a case study, after detrending, Laos δ18Op from IsoGSM since 1900 AD is moderately correlated with the NINO3.4 index (r=0.53) and with the IOD index at a lag of 1 year (r = -0.35). This indicates that interannual variability of δ18Op at our site is likely controlled by ENSO.

  2. Steady inter and intra-annual decrease in the vocalization frequency of Antarctic blue whales.

    PubMed

    Gavrilov, Alexander N; McCauley, Robert D; Gedamke, Jason

    2012-06-01

    Time averaged narrow-band noise near 27 Hz produced by vocalizations of many distant Antarctic blue whales intensifies seasonally from early February to late October in the ocean off Australia's South West. Spectral characteristics of long term patterns in this noise band were analyzed using ambient noise data collected at the Comprehensive Nuclear-Test-Ban Treaty hydroacoustic station off Cape Leeuwin, Western Australia over 2002-2010. Within 7 day averaged noise spectra derived from 4096-point FFT (∼0.06 Hz frequency resolution), the -3-dB width of the spectral peak from the upper tone of Antarctic blue whale vocalization was about 0.5 Hz. The spectral frequency peak of this tonal call was regularly but not gradually decreasing over the 9 years of observation from ∼27.7 Hz in 2002 to ∼26.6 Hz in 2010. The average frequency peak steadily decreased at a greater rate within a season at 0.4-0.5 Hz/season but then in the next year recovered to approximately the mean value of the previous season. A regression analysis showed that the interannual decrease rate of the peak frequency of the upper tonal call was 0.135 ± 0.003 Hz/year over 2002-2010 (R(2) ≈ 0.99). Possible causes of such a decline in the whale vocalization frequency are considered.

  3. Robustness of cluster synchronous patterns in small-world networks with inter-cluster co-competition balance

    SciTech Connect

    Zhang, Jianbao; Ma, Zhongjun; Chen, Guanrong

    2014-06-15

    All edges in the classical Watts and Strogatz's small-world network model are unweighted and cooperative (positive). By introducing competitive (negative) inter-cluster edges and assigning edge weights to mimic more realistic networks, this paper develops a modified model which possesses co-competitive weighted couplings and cluster structures while maintaining the common small-world network properties of small average shortest path lengths and large clustering coefficients. Based on theoretical analysis, it is proved that the new model with inter-cluster co-competition balance has an important dynamical property of robust cluster synchronous pattern formation. More precisely, clusters will neither merge nor split regardless of adding or deleting nodes and edges, under the condition of inter-cluster co-competition balance. Numerical simulations demonstrate the robustness of the model against the increase of the coupling strength and several topological variations.

  4. Seasonal and Inter-Annual Changes in the Distribution of Dominant Phytoplancton Groups in the Global Ocean

    NASA Astrophysics Data System (ADS)

    Severine, A.; Cyril, M.; Yves, D.; Laurent, B.; Hubert, L.

    2006-12-01

    The fate of fixed organic carbon in the ocean strongly varies with the phytoplankton group that makes photosynthesis. The monitoring of phytoplankton groups in the global ocean is thus of primary importance to evaluate and improve ocean carbon models. A new method (PHYSAT; Alvain et al., 2005) enables to distinguish between four different groups from space using SeaWiFS ocean color measurements. In addition to these four initial phytoplankton groups, which are diatoms, Prochlorococcus, Synecochoccus and haptophytes, we show that PHYSAT is also capable of identifying blooms of phaeocystis and coccolithophorids. Daily global SeaWiFS level-3 data from September 1997 to December 2004 were processed using PHYSAT. We present here the first monthly mean global climatology of the dominant phytoplankton groups. The seasonal cycle is discussed, with particular emphasis on the succession of phytoplankton groups during the North Atlantic spring bloom and on the coexistence of large phaeocystis and diatoms blooms during winter in the Austral Ocean. We also present the inter-annual variability for the 1998-2004 period. The contribution of diatoms to the total chlorophyll is highly variable (up to a factor of two) from one year to the other in both Atlantic and Austral Oceans, suggesting a significant variability in organic carbon export by diatoms in these regions. On the opposite, the phaeocystis contribution is less variable in the Austral Ocean.

  5. Satellite observations reveal little inter-annual variability in the radiant flux from the Mount Erebus lava lake

    NASA Astrophysics Data System (ADS)

    Wright, Robert; Pilger, Eric

    2008-11-01

    Satellite remote sensing represents a mature technology for long-term monitoring of volcanic activity at Mount Erebus, either independently or as a complement to field instrumentation. Observations made on 4290 discrete occasions over a six year period by NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) indicate that the radiant flux from the volcano's summit crater (and by inference, the lava lake contained therein), while variable on the time scale of days to weeks, has varied little on an inter-annual basis over this period. The average radiant flux from the lake during this time was 15 MW, with a maximum flux of 100 MW. Such heat flux time-series have been shown to act as a reliable proxy for general levels of activity at erupting volcanoes around the world, particularly when these time-series are of a long duration. The apparent stability of Erebus' power output is in marked contrast to fluxes observed at three other terrestrial volcanoes, Erta 'Ale (Ethiopia), Nyiragongo (Democratic Republic of Congo) and Ambrym (Vanuatu), which, while also hosting active lava lakes, all exhibit much greater variability in radiant flux over the same period of time. The results presented in this paper are confluent with those obtained from geochemical considerations of the Erebus' degassing regime, and confirm that remarkably stable open-system volcanism appears to be characteristic of this long-active volcano.

  6. Inter-cohort growth patterns of pharaoh cuttlefish Sepia pharaonis (Sepioidea: Sepiidae) in Eastern Arabian Sea.

    PubMed

    Sasikumarl, Geetha; Mohamed, K S; Bhat, U S

    2013-03-01

    Sepia pharaonis is an important commercial species endemic to the tropical Indo-Pacific region. Despite its commercial significance, only few information on natural populations is available. This study was aimed to describe the aspects of size-composition, length-weight relationship, catch rates, seasonal recruitment and inter-cohort growth patterns of S. pharaonis population (Clade C), distributed along the Eastern Arabian Sea (South-West coast of India). For this, the Dorsal Mantle Length (DML) and weight of cuttlefishes was obtained from commercial trawl catches, from April 2002 to October 2006. Data was analyzed by normal length-weight methods such as von Bertalanffy. A total of 12454 cuttlefishes, ranging in length from four to 41cm were analyzed. Size-composition patterns discriminated two pulses in recruitment to the fishery, discernible by a decrease in the monthly mean size of the population. The DMLs of the two seasonal cohorts were subjected to modal-progression analysis using the Bhattacharya's method for the estimation of growth. The estimated parameters Linfinity and K in von Bertalanffy Growth Function (VBGF) were used to model growth curves in length for the cohorts. The first cohort, (post-monsoon cohort) which supports the major fishery, was composed of medium-sized, fast growing individuals, whereas the second cohort (pre-monsoon cohort), comprised of slow growing and large-sized individuals. There were differential growth characteristics between the sexes and the life span was estimated at less than 2.3 years for males and 2.1 years for females. Negative allometric growth in weight (W) with length (L) was observed for males (W=0.33069.L2.5389) and females (W=0.32542.L26057). The females were heavier compared to males at any given mantle length, and the males were found to attain larger ultimate lengths. The major fishing season for cuttlefish was from May to November, when higher monthly catch rates of 1.67-13.02kg/h were observed in comparison

  7. Inter-annual variability of exchange processes at the outer Black Sea shelf

    NASA Astrophysics Data System (ADS)

    Shapiro, Georgy; Wobus, Fred; Yuan, Dongliang; Wang, Zheng

    2014-05-01

    vertical discretisation (s-on-top-of-z) and other improved parameters of the model set-up as in Shapiro et al. (2013). The model was run for the period from 1979 to 2012 with water discharges from 8 main rivers, exchanges through Bosporus and meteo forcing from the Drakkar Forcing Set 5.2 (Brodeau et al, 2010). The model was spun-up from climatological temperature and salinity in January using a semi-diagnostic adjustment method. Each annual simulation started from the same initial state on 1 January without data assimilation. The data for the warm period from 1 May to 31 October of each year were used for the following analysis. The model has been validated against in-situ (based on 77867 stations) and night-time satellite monthly mean SST observations. The model also captures well the major features seen on snapshot satellite images. A simulated daily climatology was created by averaging the temperature values over the 34-year simulation. Anomalies were calculated as the deviations of the snapshot temperatures from their climatological values. The correlation between the temperature anomalies of BSW on the outer shelf and those in the CIL waters in the deep sea were computed as well as water transports between these water masses across the shelf break. The BSW on the outer shelf are defined as the waters between the density level σθ=14.2 kg m3 (i.e. the bottom of the surface mixed layer) and the seabed (max z=150 m at the shelf break). The corresponding data from open sea CIL waters in the northwest part of the deep Black Sea were taken from the depth range between σθ=14.2 and z=150 m. The computed Pierson correlation between summer temperatures of BSW and the deep sea CIL is R = 0.90. This significant correlation is in agreement with the analysis from observational data of Shapiro et al. (2011). In order to reveal a physical link between the BSW and CIL, the in-out transports of water with σθ ≥14.2 across the shelf break were computed for each day and then

  8. Impact of Precipitation Patterns on Biomass and Species Richness of Annuals in a Dry Steppe

    PubMed Central

    Yan, Hong; Liang, Cunzhu; Li, Zhiyong; Liu, Zhongling; Miao, Bailing; He, Chunguang; Sheng, Lianxi

    2015-01-01

    Annuals are an important component part of plant communities in arid and semiarid grassland ecosystems. Although it is well known that precipitation has a significant impact on productivity and species richness of community or perennials, nevertheless, due to lack of measurements, especially long-term experiment data, there is little information on how quantity and patterns of precipitation affect similar attributes of annuals. This study addresses this knowledge gap by analyzing how quantity and temporal patterns of precipitation affect aboveground biomass, interannual variation aboveground biomass, relative aboveground biomass, and species richness of annuals using a 29-year dataset from a dry steppe site at the Inner Mongolia Grassland Ecosystem Research Station. Results showed that aboveground biomass and relative aboveground biomass of annuals increased with increasing precipitation. The coefficient of variation in aboveground biomass of annuals decreased significantly with increasing annual and growing-season precipitation. Species richness of annuals increased significantly with increasing annual precipitation and growing-season precipitation. Overall, this study highlights the importance of precipitation for aboveground biomass and species richness of annuals. PMID:25906187

  9. Impact of precipitation patterns on biomass and species richness of annuals in a dry steppe.

    PubMed

    Yan, Hong; Liang, Cunzhu; Li, Zhiyong; Liu, Zhongling; Miao, Bailing; He, Chunguang; Sheng, Lianxi

    2015-01-01

    Annuals are an important component part of plant communities in arid and semiarid grassland ecosystems. Although it is well known that precipitation has a significant impact on productivity and species richness of community or perennials, nevertheless, due to lack of measurements, especially long-term experiment data, there is little information on how quantity and patterns of precipitation affect similar attributes of annuals. This study addresses this knowledge gap by analyzing how quantity and temporal patterns of precipitation affect aboveground biomass, interannual variation aboveground biomass, relative aboveground biomass, and species richness of annuals using a 29-year dataset from a dry steppe site at the Inner Mongolia Grassland Ecosystem Research Station. Results showed that aboveground biomass and relative aboveground biomass of annuals increased with increasing precipitation. The coefficient of variation in aboveground biomass of annuals decreased significantly with increasing annual and growing-season precipitation. Species richness of annuals increased significantly with increasing annual precipitation and growing-season precipitation. Overall, this study highlights the importance of precipitation for aboveground biomass and species richness of annuals.

  10. Inter-rater reliability for movement pattern analysis (MPA): measuring patterning of behaviors versus discrete behavior counts as indicators of decision-making style

    PubMed Central

    Connors, Brenda L.; Rende, Richard; Colton, Timothy J.

    2014-01-01

    The unique yield of collecting observational data on human movement has received increasing attention in a number of domains, including the study of decision-making style. As such, interest has grown in the nuances of core methodological issues, including the best ways of assessing inter-rater reliability. In this paper we focus on one key topic – the distinction between establishing reliability for the patterning of behaviors as opposed to the computation of raw counts – and suggest that reliability for each be compared empirically rather than determined a priori. We illustrate by assessing inter-rater reliability for key outcome measures derived from movement pattern analysis (MPA), an observational methodology that records body movements as indicators of decision-making style with demonstrated predictive validity. While reliability ranged from moderate to good for raw counts of behaviors reflecting each of two Overall Factors generated within MPA (Assertion and Perspective), inter-rater reliability for patterning (proportional indicators of each factor) was significantly higher and excellent (ICC = 0.89). Furthermore, patterning, as compared to raw counts, provided better prediction of observable decision-making process assessed in the laboratory. These analyses support the utility of using an empirical approach to inform the consideration of measuring patterning versus discrete behavioral counts of behaviors when determining inter-rater reliability of observable behavior. They also speak to the substantial reliability that may be achieved via application of theoretically grounded observational systems such as MPA that reveal thinking and action motivations via visible movement patterns. PMID:24999336

  11. Inter-annual fluctuations of zooplankton communities in the Bay of Villefranche-sur-mer from 1995 to 2005 (Northern Ligurian Sea, France)

    NASA Astrophysics Data System (ADS)

    Vandromme, P.; Stemmann, L.; Berline, L.; Gasparini, S.; Mousseau, L.; Prejger, F.; Passafiume, O.; Guarini, J.-M.; Gorsky, G.

    2011-11-01

    An integrated analysis of the pelagic ecosystems of the Ligurian Sea is performed combining time series (1995-2005) of several zooplankton groups (one group for copepods smaller than 0.724 mm3 and nine groups for individuals larger than 0.724 mm3, i.e. large copepods, decapod larvæ, other crustaceans, chaetognaths, appendicularians, pteropods, thaliaceans, gelatinous predators and other zooplankton), chlorophyll-a, nutrients, salinity, temperature, density, and local weather at Point B coastal station (Northern Ligurian Sea). From 1995 to 2000 winters were wet and mild resulting in lower winter sea surface density. These years showed lower than average nutrients and zooplankton concentrations while chlorophyll-a biomass was high. After 2000, winters were colder and dryer resulting in higher sea surface density. Nutrients and zooplankton showed higher concentrations while chlorophyll-a was lower than average. The ca. 2000 change was observed for most zooplankton groups with a one-year delay for some groups. Inter-annual variability within each period was also observed. The observed patterns suggest that the pelagic ecosystem trophic state at the studied point is mostly set by the winter forcing on the vertical mixing that upwells nutrients to the surface sustaining primary production. Surprisingly, low chlorophyll-a biomass in high nitrate and zooplankton conditions during the well mixed years suggest that phytoplankton biomass is controlled by grazers. The proposed mechanisms of stronger winter vertical mixing hold for most of the time series, but specific years with contradicting patterns suggest also the possible influence of the summer climate. A review of recent literature suggests that changes in the pelagic ecosystem are not limited to the studied site but concern also the central Ligurian Sea.

  12. Effects of clouds on the Earth radiation budget; Seasonal and inter-annual patterns

    NASA Technical Reports Server (NTRS)

    Dhuria, Harbans L.

    1992-01-01

    Seasonal and regional variations of clouds and their effects on the climatological parameters were studied. The climatological parameters surface temperature, solar insulation, short-wave absorbed, long wave emitted, and net radiation were considered. The data of climatological parameters consisted of about 20 parameters of Earth radiation budget and clouds of 2070 target areas which covered the globe. It consisted of daily and monthly averages of each parameter for each target area for the period, Jun. 1979 - May 1980. Cloud forcing and black body temperature at the top of the atmosphere were calculated. Interactions of clouds, cloud forcing, black body temperature, and the climatological parameters were investigated and analyzed.

  13. Inter-annual Variations and Decadal Trends in Surface Equatorial Pacific Phosphate Concentrations: Coral Records from the Line Islands

    NASA Astrophysics Data System (ADS)

    Sinclair, D. J.; Sherrell, R. M.; LaVigne, M.; Tudhope, A. W.; Cobb, K.

    2011-12-01

    Coralline P/Ca is a newly-calibrated proxy for oceanic phosphate concentration (LaVigne et al. 2010, Anagnostuou et al. 2011). This proxy is an important tool for reconstructing tropical ocean nutrient dynamics, especially in remote regions, such as the equatorial Pacific Ocean, which are poorly covered by instrumental records. Here we present P/Ca records in 4 Porites corals from the Line Islands in the central Equatorial Pacific spanning the last ~ 30 years. The coral from Jarvis Island (0°22'S) has a significantly higher P/Ca concentration than two independent coral records from Christmas Island (1°53'N), and a coral from Fanning Island (3°51'N). This is consistent with the strong meridional gradient in surface phosphate in the central equatorial Pacific. All corals record a long-term 2-fold decrease in phosphate concentration from the mid 1970s to the mid 1990s, in agreement with observed slowing of the Pacific Meridional Overturning Circulation (McPhadden and Zhang 2002). On inter-annual time scales, the corals all capture strong El Niño events as a decrease in surface phosphate consistent with deepening of the eastern Pacific thermocline. The magnitude of this suppression is significantly larger in the Jarvis Island coral, again consistent with its location in the high phosphate tongue in the equatorial Pacific. The Jarvis Island coral record shows hints of a decadal oscillation in P which so far does not appear to be captured by the Christmas Island coral. Further analyses are underway to extend these records and to study P dynamics in other Line Island corals. Our preliminary results suggest that Porites corals are recording P variations in the central Pacific which accord with known oceanographic changes. This study demonstrates the potential for reconstructing nutrient dynamics at annual to multidecadal resolutions. Citations LaVigne M., Matthews K. A., Grottoli A. G., Cobb K. M., Anagnostou E., Cabioch G., and Sherrell R. M. (2010) Coral skeleton P

  14. Evaluating the effects of China's pollution control on inter-annual trends and uncertainties of atmospheric mercury emissions

    NASA Astrophysics Data System (ADS)

    Zhao, Y.; Zhong, H.; Zhang, J.; Nielsen, C. P.

    2014-10-01

    China's atmospheric mercury (Hg) emissions of anthropogenic origin have been effectively restrained through the national policy of air pollution control. Improved methods based on available field measurements are developed to quantify the benefits of Hg abatement through various emission control measures. Those measures include increased use of flue gas desulfurization (FGD) and selective catalyst reduction (SCR) systems for power sector, precalciners with fabric filter (FF) for cement production, machinery coking with electrostatic precipitator (ESP) for iron and steel production, and advanced manufacturing technologies for nonferrous metal smelting. Declining trends in emissions factors for those sources are revealed, leading to a much slower growth of national total Hg emissions than that of energy and economy, from 679 in 2005 to 750 metric tons (t) in 2012. In particular, nearly half of emissions from the above-mentioned four types of sources are expected to be reduced in 2012, attributed to expansion of technologies with high energy efficiencies and air pollutant removal rates after 2005. The speciation of Hg emissions keeps stable for recent years, with the mass fractions of around 55, 39 and 6% for Hg0, Hg2+ and Hgp, respectively. The lower estimate of Hg emissions than previous inventories is supported by limited chemistry simulation work, but middle-to-long term observation on ambient Hg levels is further needed to justify the inter-annual trends of estimated Hg emissions. With improved implementation of emission controls and energy saving, 23% reduction in annual Hg emissions for the most optimistic case in 2030 is expected compared to 2012, with total emissions below 600 t. While Hg emissions are evaluated to be gradually constrained, increased uncertainties are quantified with Monte-Carlo simulation for recent years, particularly for power and certain industrial sources. The uncertainty of Hg emissions from coal-fired power plants, as an example

  15. Predicting Distribution and Inter-Annual Variability of Tropical Cyclone Intensity from a Stochastic, Multiple-Linear Regression Model

    NASA Astrophysics Data System (ADS)

    Lee, C. Y.; Tippett, M. K.; Sobel, A. H.; Camargo, S. J.

    2014-12-01

    We are working towards the development of a new statistical-dynamical downscaling system to study the influence of climate on tropical cyclones (TCs). The first step is development of an appropriate model for TC intensity as a function of environmental variables. We approach this issue with a stochastic model consisting of a multiple linear regression model (MLR) for 12-hour intensity forecasts as a deterministic component, and a random error generator as a stochastic component. Similar to the operational Statistical Hurricane Intensity Prediction Scheme (SHIPS), MLR relates the surrounding environment to storm intensity, but with only essential predictors calculated from monthly-mean NCEP reanalysis fields (potential intensity, shear, etc.) and from persistence. The deterministic MLR is developed with data from 1981-1999 and tested with data from 2000-2012 for the Atlantic, Eastern North Pacific, Western North Pacific, Indian Ocean, and Southern Hemisphere basins. While the global MLR's skill is comparable to that of the operational statistical models (e.g., SHIPS), the distribution of the predicted maximum intensity from deterministic results has a systematic low bias compared to observations; the deterministic MLR creates almost no storms with intensities greater than 100 kt. The deterministic MLR can be significantly improved by adding the stochastic component, based on the distribution of random forecasting errors from the deterministic model compared to the training data. This stochastic component may be thought of as representing the component of TC intensification that is not linearly related to the environmental variables. We find that in order for the stochastic model to accurately capture the observed distribution of maximum storm intensities, the stochastic component must be auto-correlated across 12-hour time steps. This presentation also includes a detailed discussion of the distributions of other TC-intensity related quantities, as well as the inter-annual

  16. Climate and the Individual: Inter-Annual Variation in the Autumnal Activity of the European Badger (Meles meles)

    PubMed Central

    Noonan, Michael J.; Markham, Andrew; Newman, Chris; Trigoni, Niki; Buesching, Christina D.; Ellwood, Stephen A.; Macdonald, David W.

    2014-01-01

    We establish intra-individual and inter-annual variability in European badger (Meles meles) autumnal nightly activity in relation to fine-scale climatic variables, using tri-axial accelerometry. This contributes further to understanding of causality in the established interaction between weather conditions and population dynamics in this species. Modelling found that measures of daylight, rain/humidity, and soil temperature were the most supported predictors of ACTIVITY, in both years studied. In 2010, the drier year, the most supported model included the SOLAR*RH interaction, RAIN, and30cmTEMP (w = 0.557), while in 2012, a wetter year, the most supported model included the SOLAR*RH interaction, and the RAIN*10cmTEMP (w = 0.999). ACTIVITY also differed significantly between individuals. In the 2012 autumn study period, badgers with the longest per noctem activity subsequently exhibited higher Body Condition Indices (BCI) when recaptured. In contrast, under drier 2010 conditions, badgers in good BCI engaged in less per noctem activity, while badgers with poor BCI were the most active. When compared on the same calendar dates, to control for night length, duration of mean badger nightly activity was longer (9.5 hrs ±3.3 SE) in 2010 than in 2012 (8.3 hrs ±1.9 SE). In the wetter year, increasing nightly activity was associated with net-positive energetic gains (from BCI), likely due to better foraging conditions. In a drier year, with greater potential for net-negative energy returns, individual nutritional state proved crucial in modifying activity regimes; thus we emphasise how a ‘one size fits all’ approach should not be applied to ecological responses. PMID:24465376

  17. Accounting for inter-annual and seasonal variability in regionalization of hydrologic response in the Great Lakes basin

    NASA Astrophysics Data System (ADS)

    Kult, J. M.; Fry, L. M.; Gronewold, A. D.

    2012-12-01

    Methods for predicting streamflow in areas with limited or nonexistent measures of hydrologic response typically invoke the concept of regionalization, whereby knowledge pertaining to gauged catchments is transferred to ungauged catchments. In this study, we identify watershed physical characteristics acting as primary drivers of hydrologic response throughout the US portion of the Great Lakes basin. Relationships between watershed physical characteristics and hydrologic response are generated from 166 catchments spanning a variety of climate, soil, land cover, and land form regimes through regression tree analysis, leading to a grouping of watersheds exhibiting similar hydrologic response characteristics. These groupings are then used to predict response in ungauged watersheds in an uncertainty framework. Results from this method are assessed alongside one historical regionalization approach which, while simple, has served as a cornerstone of Great Lakes regional hydrologic research for several decades. Our approach expands upon previous research by considering multiple temporal characterizations of hydrologic response. Due to the substantial inter-annual and seasonal variability in hydrologic response observed over the Great Lakes basin, results from the regression tree analysis differ considerably depending on the level of temporal aggregation used to define the response. Specifically, higher levels of temporal aggregation for the response metric (for example, indices derived from long-term means of climate and streamflow observations) lead to improved watershed groupings with lower within-group variance. However, this perceived improvement in model skill occurs at the cost of understated uncertainty when applying the regression to time series simulations or as a basis for model calibration. In such cases, our results indicate that predictions based on long-term characterizations of hydrologic response can produce misleading conclusions when applied at shorter

  18. Climate and the individual: inter-annual variation in the autumnal activity of the European badger (Meles meles).

    PubMed

    Noonan, Michael J; Markham, Andrew; Newman, Chris; Trigoni, Niki; Buesching, Christina D; Ellwood, Stephen A; Macdonald, David W

    2014-01-01

    We establish intra-individual and inter-annual variability in European badger (Meles meles) autumnal nightly activity in relation to fine-scale climatic variables, using tri-axial accelerometry. This contributes further to understanding of causality in the established interaction between weather conditions and population dynamics in this species. Modelling found that measures of daylight, rain/humidity, and soil temperature were the most supported predictors of ACTIVITY, in both years studied. In 2010, the drier year, the most supported model included the SOLAR*RH interaction, RAIN, and 30cmTEMP (w = 0.557), while in 2012, a wetter year, the most supported model included the SOLAR*RH interaction, and the RAIN*10cmTEMP (w = 0.999). ACTIVITY also differed significantly between individuals. In the 2012 autumn study period, badgers with the longest per noctem activity subsequently exhibited higher Body Condition Indices (BCI) when recaptured. In contrast, under drier 2010 conditions, badgers in good BCI engaged in less per noctem activity, while badgers with poor BCI were the most active. When compared on the same calendar dates, to control for night length, duration of mean badger nightly activity was longer (9.5 hrs ±3.3 SE) in 2010 than in 2012 (8.3 hrs ±1.9 SE). In the wetter year, increasing nightly activity was associated with net-positive energetic gains (from BCI), likely due to better foraging conditions. In a drier year, with greater potential for net-negative energy returns, individual nutritional state proved crucial in modifying activity regimes; thus we emphasise how a 'one size fits all' approach should not be applied to ecological responses.

  19. Inter-annual variability of summertime CO2 exchange in Northern Eurasia inferred from GOSAT XCO2

    NASA Astrophysics Data System (ADS)

    Ishizawa, M.; Mabuchi, K.; Shirai, T.; Inoue, M.; Morino, I.; Uchino, O.; Yoshida, Y.; Belikov, D.; Maksyutov, S.

    2016-10-01

    Northern Eurasia is one of the largest terrestrial carbon reservoirs on the Earth’s surface. However, since the coverage of surface CO2 observations is still limited, the response to the climate variability remains uncertain. We estimated monthly CO2 fluxes for three sub-regions in Northern Eurasia (north of ˜60°N), Northeastern Europe, Western Siberia and Eastern Siberia, using CO2 retrievals from the Japanese Greenhouse Gases Observing SATellite (GOSAT). The variations of estimated CO2 fluxes were examined in terms of the regional climate variability, for the three consecutive growing seasons of 2009-2011. The CO2 fluxes estimated using GOSAT data are highly correlated with the surface temperature anomalies in July and August (r > 0.8) while no correlation is found in the CO2 fluxes estimated only using surface observations. The estimated fluxes from GOSAT data exhibit high negative correlations with one-month lagged positive precipitation anomalies in late summer (r > -0.7) through surface temperature and the Normalized Difference Vegetation Index (NDVI). The results indicate that GOSAT data reflects the changes in terrestrial biospheric processes responding to climate anomalies. In 2010, a large part of Eurasia experienced an extremely hot and dry summer, while cold and wet weather conditions were recorded in Western Siberia. The CO2 fluxes estimated from GOSAT data showed a reduction of net CO2 uptake in Northeastern Europe and Eastern Siberia, but the enhancement of net CO2 uptake in Western Siberia. These opposite sub-regional flux anomalies can be explained by the different climate anomalies on a sub-regional scale in Northern Eurasia. Thus, this study demonstrates that space-based observations by GOSAT compensate for the lack of ground-based observational coverage so as to better capture the inter-annually varying atmosphere-terrestrial biosphere CO2 exchange on a regional scale.

  20. Inter-annual variability of stream temperature, micro-climate and heat exchange dynamics: a comparison of forest and moorland environments

    NASA Astrophysics Data System (ADS)

    Garner, G.; Hannah, D. M.; Malcolm, I. A.; Sadler, J. P.

    2012-04-01

    Riparian woodland is recognised as important in moderating stream temperature variability and offers potential to mitigate thermal extremes under a warming climate. Previous research on the heat exchanges determining water column temperature has been often short-term, or seasonally-constrained, with the few long term year-round studies limited to a maximum of two years. This paper addresses these research gaps by comparing inter-annual variability in stream temperature, micro-climate and heat exchange dynamics between stream reaches of contrasting riparian landuse. Automatic weather stations (AWS) were installed in semi-natural woodland and moorland (no trees) reaches of the Girnock Burn, an upland tributary of the Aberdeenshire Dee. Data were collected across all seasons over seven calendar years. This research yields, for the first time, a long-term perspective on temporal differences in river heat exchange processes associated with riparian landuse under a range of hydroclimatological conditions. Results indicate that the presence of a riparian canopy has a persistent effect year-to-year in reducing mean and maximum daily water column temperature under a variety of hydrological and meteorological conditions. Woodland and moorland reaches display similar inter-annual variability in daily water column temperature range during spring and early summer, but in mid-summer and autumn woodland inter-annual variability is reduced greatly compared with moorland. Higher inter-annual variability (indicated by standard deviations) in spring and early summer water temperature ranges at both sites are attributed to increasing day length and solar radiation receipt, which a developing forest canopy at the woodland site is not able to mitigate. Once the full riparian canopy, hence maximum shading potential, is established (mid-summer) inter-annual variability in woodland temperature range is reduced greatly. The magnitude of woodland water temperature range is greater in spring

  1. Intra-annual patterns in adult band-tailed pigeon survival estimates

    USGS Publications Warehouse

    Casazza, Michael L.; Coates, Peter S.; Overton, Cory T.; Howe, Kristy H.

    2015-01-01

    Implications: We present the first inter-seasonal analysis of survival probability of the Pacific coast race of band-tailed pigeons and illustrate important temporal patterns that may influence future species management including harvest strategies and disease monitoring.

  2. Class and University Education: Inter-Generational Patterns in Canada. NALL Working Paper.

    ERIC Educational Resources Information Center

    Livingstone, D. W.; Stowe, Susan

    Young people from lower class origins continue to face major barriers to university education in Canada. This paper documents both substantial inter-generational class mobility and continuing inequalities in formal educational attainments by class origins. While Canada now has the world's higher educational attainments in its youth cohort and has…

  3. Seasonal and inter-annual variability of sea surface temperature at the east coast fishing area off Peninsular Malaysia

    NASA Astrophysics Data System (ADS)

    Nurul Ridani, S.; Mustapha, M. A.; Lihan, T.; Ku Kassim, K. Y.; Raja Bidin, R. H.

    2015-09-01

    Empirical orthogonal function (EOF) analysis was used to study a time-series of the aqua MODIS data imageries in the exclusive economic zone of east coast off Peninsular Malaysia. Temporal and spatial characteristics were examined to determine the dominant pattern of sea surface temperature (SST) variability from January 2003 to December 2011.The data were analysed from daily Level 1A (1km spatial resolution) to monthly composites Level 3 data using SeaDAS and ERDAS imagine software. Four modes was obtained from the analysis with the highest variance (7.9%) represented by mode 1 which explained the seasonal cycle. Mode 2 (5.11 % of total variance) showed positive and negative peak signal during March and April and in October and November with variability near the Kelantan and Pahang waters that indicated the inter monsoon. Mode 3 (3.8 % of variance) shows variability near the Terengganu, Kelantan and Johor waters to the open sea during July and August and in May and June representing the Southwest monsoon. Mode 4 (3.36 %) showed positive signal during November and December with strong signal near Pahang and Kelantan waters while weak signal was detected near Terengganu and Kelantan's open sea representing the Northeast monsoon. The SST variability was influenced by the monsoonal system which originated by the wind forcing condition that influences circulation in the study area.

  4. Inter-annual precipitation variabiity inferred from late Holocene speleothem records from Fiji: implications for SPCZ localisation and ENSO behaviour

    NASA Astrophysics Data System (ADS)

    Mattey, D.; Stephens, M.; Hoffmann, D.; Brett, M.

    2015-12-01

    The modern tropical Fiji climate is characterised by seasonal rainfall controlled by the position of the South Pacific Convergence Zone (SPCZ). Interannual rainfall is strongly modulated on decadal timescales by ENSO with higher rainfall associated with La Nina events. Voli Voli cave near Sigatoga (Viti Levu) is a stream passage that has been monitored since 2009. A U-Th dated laminated speleothem spans a 1500 year interval across the transition from the Medieval Warm Period into the Little Ice Age marked by a fabric change from finely laminated calcite with thin clay layers, to white well-laminated calcite. The older record is characterised by rising δ13C values followed by a rapid decrease in δ13C around 1200 AD. Evidence from cave monitoring shows that cave air CO2 levels are strongly seasonal as a result of greater ventilation by winter trade winds and high resolution δ13C record shows regularly spaced peaks correlated with paired laminae and cycles in P and S which provide annual markers driven by rainfall and seasonal ventilation. δ18O values remain relatively unchanged throughout the record but micromilling at sub-annual resolution reveals systematic cycles in δ18O that span groups of paired laminae with an inferred periodicity of 3-7 years i.e. a similar frequency to modern ENSO. The presence of these sub-decadal cycles in δ18O may be a result of a combination of factors. The amplitude of 2-3‰ would be equivalent to an amount-effect related change in annual precipitation of around 50% but an additional smoothing process, perhaps a result of aquifer storage, is required to attenuate interannual variance in precipitation. The Voli Voli record provides evidence of an underlying climatic change to more frequent La Niña conditions from 1200 AD and may be associated with increased conflict, shifts in settlements and changes in subsistence strategies on the island. Coeval speleothem isotope records from tropical Pacific Islands provide a provide a

  5. Intra- and inter-speaker variations of formant pattern for lateral syllables in Standard Chinese.

    PubMed

    Zhang, Cuiling; van de Weijer, Joost; Cui, Jingxu

    2006-05-10

    Speech variation of speakers is a crucial issue for speaker recognition and identification, especially for forensic practice. Greater intra-speaker variation is one main reason for incorrect speaker identification in real forensic situations. Understanding the stability of acoustic parameters and their variation in speech is therefore significant for the evaluation of effective parameters for speaker identification. In this paper, all vowels in Standard Chinese including five monophthongs, eight diphthongs and four triphthongs were combined with lateral /l/. Finally, 15 lateral syllables with different tones for 10 speakers were selected and acoustically analyzed. Central frequencies of the first four formants for each syllable were measured for quantitative comparison of intra- and inter-speaker variation in order to provide a general idea of speaker variation in Standard Chinese, and finally serving for forensic application. Results show that the overall intra-speaker variation is less than the inter-speaker variation in great extent under laboratory condition though occasionally they are contrary. This supports the basis for forensic speaker identification, that is, intra-speaker variation should be less than inter-speaker variation in many acoustic features, and further validates the probability and reliability of forensic speaker identification.

  6. Impacts of high inter-annual variability of rainfall on a century of extreme hydrologic regime of northwest Australia

    NASA Astrophysics Data System (ADS)

    Rouillard, A.; Skrzypek, G.; Dogramaci, S.; Turney, C.; Grierson, P. F.

    2015-04-01

    Long-term hydrologic records provide crucial reference baselines of natural variability that can be used to evaluate potential changes in hydrologic regimes and their impacts. However, there is a dearth of studies of the hydrologic regimes for tropical drylands where intraseasonal and interannual variability in magnitude and frequency of precipitation are extreme. Here, we sought to identify the main hydroclimatic determinants of the strongly episodic flood regime of a large catchment in the semi-arid, subtropical northwest of Australia and to establish the background of hydrologic variability for the region over the last century. We used a monthly sequence of satellite images to quantify surface water expression on the Fortescue Marsh, the largest water feature of inland northwest Australia, from 1988 to 2012. We used this sequence together with instrumental rainfall data to build a statistical model with multiple linear regression and reconstruct monthly history of floods and droughts since 1912. We found that severe and intense regional rainfall events, as well as the sequence of recharge events both within and between years, determine surface water expression on the floodplain (i.e. total rainfall, number of rain days and carried-over inundated area; R2adj = 0.79; p value < 0.001, ERMSP = 56 km2). The most severe reconstructed inundation over the last century was in March 2000 (1000 km2), which is less than the 1300 km2 area required to overflow to the adjacent catchment. The Fortescue Marsh was completely dry for 32% of all years, for periods of up to four consecutive years. Extremely wet years (seven of the 100 years) caused the Marsh to remain inundated for up to 12 months; only 25% of years (9% of all months) had floods of greater than 300 km2. The prolonged, severe and consecutive yearly inundations between 1999 and 2006 were unprecedented compared to the last century. While there is high inter-annual variability in the system, if the frequency and

  7. Potential Influence of Arctic Sea Ice to the Inter-annual Variations of East Asian Spring Precipitation

    NASA Astrophysics Data System (ADS)

    Li, Xinxin; Wu, Zhiwei; Li, Yanjie

    2016-04-01

    Arctic sea ice (ASI) and its potential climatic impacts have received increasing attention during the past decades, yet the relevant mechanisms are far from being understood, particularly on how anomalous ASI affects climate in midlatitudes. The spring precipitation takes up as much as 30% of the annual total and has significant influences to agriculture in East Asia. Here, observed evidence and numerical experiment results manifest that the ASI variability in the Norwegian Sea and the Barents Sea in preceding winter is intimately connected with interannual variations of the East Asian spring precipitation (EAP). The former can explain about 14% of the total variances of the latter. The ASI anomalies persist from winter through the ensuing spring and excite downstream tele-connections of a distinct Rossby wave train prevailing over the Eurasian continent. For the reduced ASI, such a wave train pattern is usually associated with an anomalous low pressure center over Mongolian Plateau, which accelerates the East Asian subtropical westerly jet. The intensified subtropical westerly jet, concurrent with lower-level convergence and upper-level divergence, enhances the local convection and consequently favors rich spring precipitation over East Asia. For the excessive ASI, the situation tends to be opposite. Given that seasonal prediction of the EAP remains a challenging issue, the winter ASI variability may provide another potential predictability source besides El Niño-Southern Oscillation.

  8. Intra- and inter-annual trends in phosphorus loads and comparison with nitrogen loads to Rehoboth Bay, Delaware (USA)

    NASA Astrophysics Data System (ADS)

    Volk, Jennifer A.; Scudlark, Joseph R.; Savidge, Karen B.; Andres, A. Scott; Stenger, Robert J.; Ullman, William J.

    2012-01-01

    Monthly phosphorus loads from uplands, atmospheric deposition, and wastewater to Rehoboth Bay (Delaware) were determined from October 1998 to April 2002 to evaluate the relative importance of these three sources of P to the Bay. Loads from a representative subwatershed were determined and used in an areal extrapolation to estimate the upland load from the entire watershed. Soluble reactive phosphorus (SRP) and dissolved organic P (DOP) are the predominant forms of P in baseflow and P loads from the watershed are highest during the summer months. Particulate phosphorus (PP) becomes more significant in stormflow and during periods with more frequent or larger storms. Atmospheric deposition of P is only a minor source of P to Rehoboth Bay. During the period of 1998-2002, wastewater was the dominant external source of P to Rehoboth Bay, often exceeding all other P sources combined. Since 2002, however, due to technical improvements to the sole wastewater plant discharging directly to the Bay, the wastewater contribution of P has been significantly reduced and upland waters are now the principal source of P on an annualized basis. Based on comparison of N and P loads, primary productivity and biomass carrying capacity in Rehoboth Bay should be limited by P availability. However, due to the contrasting spatial and temporal patterns of N and P loading and perhaps internal cycling within the ecosystem, spatial and temporal variations in N and P-limitation within Rehoboth Bay are likely.

  9. Intra- and inter-annual trends in phosphorus loads and comparison with nitrogen loads to Rehoboth Bay, Delaware (USA)

    USGS Publications Warehouse

    Volk, J.A.; Scudlark, J.R.; Savidge, K.B.; Andres, A.S.; Stenger, R.J.; Ullman, W.J.

    2012-01-01

    Monthly phosphorus loads from uplands, atmospheric deposition, and wastewater to Rehoboth Bay (Delaware) were determined from October 1998 to April 2002 to evaluate the relative importance of these three sources of P to the Bay. Loads from a representative subwatershed were determined and used in an areal extrapolation to estimate the upland load from the entire watershed. Soluble reactive phosphorus (SRP) and dissolved organic P (DOP) are the predominant forms of P in baseflow and P loads from the watershed are highest during the summer months. Particulate phosphorus (PP) becomes more significant in stormflow and during periods with more frequent or larger storms. Atmospheric deposition of P is only a minor source of P to Rehoboth Bay. During the period of 1998-2002, wastewater was the dominant external source of P to Rehoboth Bay, often exceeding all other P sources combined. Since 2002, however, due to technical improvements to the sole wastewater plant discharging directly to the Bay, the wastewater contribution of P has been significantly reduced and upland waters are now the principal source of P on an annualized basis. Based on comparison of N and P loads, primary productivity and biomass carrying capacity in Rehoboth Bay should be limited by P availability. However, due to the contrasting spatial and temporal patterns of N and P loading and perhaps internal cycling within the ecosystem, spatial and temporal variations in N and P-limitation within Rehoboth Bay are likely. ?? 2011 Elsevier Ltd.

  10. Preserving prairies: Understanding temporal and spatial patterns of invasive annual bromes in the Northern Great Plains

    USGS Publications Warehouse

    Ashton, Isabel; Symstad, Amy; Davis, Christopher; Swanson, Daniel J.

    2016-01-01

    Two Eurasian invasive annual brome grasses, cheatgrass (Bromus tectorum) and Japanese brome (Bromus japonicus), are well known for their impact in steppe ecosystems of the western United States where these grasses have altered fire regimes, reduced native plant diversity and abundance, and degraded wildlife habitat. Annual bromes are also abundant in the grasslands of the Northern Great Plains (NGP), but their impact and ecology are not as well studied. It is unclear whether the lessons learned from the steppe will translate to the mixed-grass prairie where native plant species are adapted to frequent fires and grazing. Developing a successful annual brome management strategy for National Park Service units and other NGP grasslands requires better understanding of (1) the impact of annual bromes on grassland condition; (2) the dynamics of these species through space and time; and (3) the relative importance of environmental factors within and outside managers' control for these spatiotemporal dynamics. Here, we use vegetation monitoring data collected from 1998 to 2015 in 295 sites to relate spatiotemporal variability of annual brome grasses to grassland composition, weather, physical environmental characteristics, and ecological processes (grazing and fire). Concern about the impact of these species in NGP grasslands is warranted, as we found a decline in native species richness with increasing annual brome cover. Annual brome cover generally increased over the time of monitoring but also displayed a 3- to 5-yr cycle of reduction and resurgence. Relative cover of annual bromes in the monitored areas was best predicted by park unit, weather, extant plant community, slope grade, soil composition, and fire history. We found no evidence that grazing reduced annual brome cover, but this may be due to the relatively low grazing pressure in our study. By understanding the consequences and patterns of annual brome invasion, we will be better able to preserve and restore

  11. Inter-dependent tissue growth and Turing patterning in a model for long bone development

    NASA Astrophysics Data System (ADS)

    Tanaka, Simon; Iber, Dagmar

    2013-10-01

    The development of long bones requires a sophisticated spatial organization of cellular signalling, proliferation, and differentiation programs. How such spatial organization emerges on the growing long bone domain is still unresolved. Based on the reported biochemical interactions we developed a regulatory model for the core signalling factors IHH, PTCH1, and PTHrP and included two cell types, proliferating/resting chondrocytes and (pre-)hypertrophic chondrocytes. We show that the reported IHH-PTCH1 interaction gives rise to a Schnakenberg-type Turing kinetics, and that inclusion of PTHrP is important to achieve robust patterning when coupling patterning and tissue dynamics. The model reproduces relevant spatiotemporal gene expression patterns, as well as a number of relevant mutant phenotypes. In summary, we propose that a ligand-receptor based Turing mechanism may control the emergence of patterns during long bone development, with PTHrP as an important mediator to confer patterning robustness when the sensitive Turing system is coupled to the dynamics of a growing and differentiating tissue. We have previously shown that ligand-receptor based Turing mechanisms can also result from BMP-receptor, SHH-receptor, and GDNF-receptor interactions, and that these reproduce the wildtype and mutant patterns during digit formation in limbs and branching morphogenesis in lung and kidneys. Receptor-ligand interactions may thus constitute a general mechanism to generate Turing patterns in nature.

  12. Seasonal changes in spatial patterns of two annual plants in the Chihuahuan Desert, USA

    USGS Publications Warehouse

    Yin, Z.-Y.; Guo, Q.; Ren, H.; Peng, S.-L.

    2005-01-01

    Spatial pattern of a biotic population may change over time as its component individuals grow or die out, but whether this is the case for desert annual plants is largely unknown. Here we examined seasonal changes in spatial patterns of two annuals, Eriogonum abertianum and Haplopappus gracilis, in initial (winter) and final (summer) densities. The density was measured as the number of individuals from 384 permanent quadrats (each 0.5 m ?? 0.5 m) in the Chihuahuan Desert near Portal, Arizona, USA. We used three probability distributions (binomial, Poisson, and negative binomial or NB) that represent three basic spatial patterns (regular, random, and clumped) to fit the observed frequency distributions of densities of the two annuals. Both species showed clear clumped patterns as characterized by the NB and had similar inverse J-shaped frequency distribution curves in two density categories. Also, both species displayed a reduced degree of aggregation from winter to summer after the spring drought (massive die-off), as indicated by the increased k-parameter of the NB and decreased values of another NB parameter p, variance/mean ratio, Lloyd's Index of Patchiness, and David and Moore's Index of Clumping. Further, we hypothesized that while the NB (i.e., Poisson-logarithmic) well fits the distribution of individuals per quadrat, its components, the Poisson and logarithmic, may describe the distributions of clumps per quadrat and of individuals per clump, respectively. We thus obtained the means and variances for (1) individuals per quadrat, (2) clumps per quadrat, and (3) individuals per clump. The results showed that the decrease of the density from winter to summer for each plant resulted from the decrease of individuals per clump, rather than from the decrease of clumps per quadrat. The great similarities between the two annuals indicate that our observed temporal changes in spatial patterns may be common among desert annual plants. ?? Springer 2005.

  13. Factors Affecting the Inter-annual to Centennial Time Scale Variability of All Indian Summer Monsoon Rainfall

    NASA Astrophysics Data System (ADS)

    Malik, Abdul; Brönnimann, Stefan

    2016-04-01

    to statistically significant positive. We conclude that the positive relation between AISMR and solar activity, as found by other authors, is due to the combined effect of AMO, PDO and multi-decadal ENSO variability on AISMR. The solar activity influences the ICFs and this influence is then transmitted to AISMR. Further, we find that there is statistically positive intrinsic relation between AISMR and AMO from 26 to 100 year time scales which is modulated by ICFs (PDO, ENSO) and ECFs. PDO, ENSO, and solar activity weaken this intrinsic relationship whereas the combined effect of ECFc (solar activity, volcanic eruptions, CO2, & tropospheric aerosol optical depth) results in strengthening of this relationship from 70 to 100 year time scales. There is a negative intrinsic relation between AISMR and PDO which is not statistically significant at any time scale. However this relationship becomes statistically significant only in the presence of combined effect of North Atlantic SSTs and ENSO (4-39 year time scale) and individual effect of TSI (3-26 year time scale) on AISMR. We also find that there is statistical significant negative relationship between AISMR and ENSO on inter-annual to centennial time scale and the strength of this relationship is modulated by solar activity from 3 to 40 year time scale.

  14. The inter-annual variability of mesosphere-thermosphere nightglow intensities and their possible coupling with cosmic factors and lower atmosphere climatology

    NASA Astrophysics Data System (ADS)

    Didebulidze, Goderdzi; Todua, Maya

    2016-07-01

    Possible coupling of the inter-annual/seasonal variations of the mesosphere-thermosphere-ionosphere parameters with cosmic factors and climatology of the lower atmosphere are considered using the nightglow intensity observations from Abastumani (41.75 E; 42.82 E) of (a) the mesopause hydroxyl OH(8-3) bands (maximum luminous layer about 87 km), (b) the thermosphere oxygen green 557.7 nm line (main maximum of luminous layer in the lower thermosphere at about 95 km and small part from the ionosphere F2 region with its peak at about 230-280 km) and (c) the red 630.0 nm line (emitted from the ionosphere F2 region with maximum luminous layer about 230-280 km), which include three eleven-year solar cycles. The observed inter-annual variations of the OH bands and green line, along with their maximal values at spring (March-April) and fall (September-October) equinoxial periods, which are noticed also from other regions, exhibit additional maxima in June. The red line intensity mainly tends to decrease at equinoxial months, while it is maximal in summer and is accompanied by relatively small increase in June (compared to May and July). Maximal values of OH band and green line intensities in June are observed both in maximum and minimum phases of solar activity. This is considered as a manifestation of the features of the upper and lower atmosphere dynamical coupling of this region of Caucasus. The importance of atmospheric gravity waves and tidal motions in the observed specifics of seasonal changes of the lower and upper atmosphere-ionosphere coupling processes is indicated. The seasonal distribution tidal motions like changes of the mesopause and lower thermosphere with 6-12 hours period variations are demonstrated, which could be in situ developed and also coupled with lower atmosphere climatology. The daily mean temperature (with maximum in August) and its changes with heights (maximum in June) can influence cloud covering of this region and thus on generation of

  15. Local network parameters can affect inter-network phase lags in central pattern generators.

    PubMed

    Jones, S R; Kopell, N

    2006-01-01

    Weakly coupled phase oscillators and strongly coupled relaxation oscillators have different mechanisms for creating stable phase lags. Many oscillations in central pattern generators combine features of each type of coupling: local networks composed of strongly coupled relaxation oscillators are weakly coupled to similar local networks. This paper analyzes the phase lags produced by this combination of mechanisms and shows how the parameters of a local network, such as the decay time of inhibition, can affect the phase lags between the local networks. The analysis is motivated by the crayfish central pattern generator used for swimming, and uses techniques from geometrical singular perturbation theory.

  16. North Atlantic Simulations in Coordinated Ocean-Ice Reference Experiments Phase II (CORE-II) . Part II; Inter-Annual to Decadal Variability

    NASA Technical Reports Server (NTRS)

    Danabasoglu, Gokhan; Yeager, Steve G.; Kim, Who M.; Behrens, Erik; Bentsen, Mats; Bi, Daohua; Biastoch, Arne; Bleck, Rainer; Boening, Claus; Bozec, Alexandra; Canuto, Vittorio M.; Howard, Armando M.; Kelley, Maxwell

    2015-01-01

    Simulated inter-annual to decadal variability and trends in the North Atlantic for the 1958-2007 period from twenty global ocean - sea-ice coupled models are presented. These simulations are performed as contributions to the second phase of the Coordinated Ocean-ice Reference Experiments (CORE-II). The study is Part II of our companion paper (Danabasoglu et al., 2014) which documented the mean states in the North Atlantic from the same models. A major focus of the present study is the representation of Atlantic meridional overturning circulation (AMOC) variability in the participating models. Relationships between AMOC variability and those of some other related variables, such as subpolar mixed layer depths, the North Atlantic Oscillation (NAO), and the Labrador Sea upper-ocean hydrographic properties, are also investigated. In general, AMOC variability shows three distinct stages. During the first stage that lasts until the mid- to late-1970s, AMOC is relatively steady, remaining lower than its long-term (1958-2007) mean. Thereafter, AMOC intensifies with maximum transports achieved in the mid- to late-1990s. This enhancement is then followed by a weakening trend until the end of our integration period. This sequence of low frequency AMOC variability is consistent with previous studies. Regarding strengthening of AMOC between about the mid-1970s and the mid-1990s, our results support a previously identified variability mechanism where AMOC intensification is connected to increased deep water formation in the subpolar North Atlantic, driven by NAO-related surface fluxes. The simulations tend to show general agreement in their representations of, for example, AMOC, sea surface temperature (SST), and subpolar mixed layer depth variabilities. In particular, the observed variability of the North Atlantic SSTs is captured well by all models. These findings indicate that simulated variability and trends are primarily dictated by the atmospheric datasets which include

  17. North Atlantic simulations in Coordinated Ocean-ice Reference Experiments phase II (CORE-II). Part II: Inter-annual to decadal variability

    NASA Astrophysics Data System (ADS)

    Danabasoglu, Gokhan; Yeager, Steve G.; Kim, Who M.; Behrens, Erik; Bentsen, Mats; Bi, Daohua; Biastoch, Arne; Bleck, Rainer; Böning, Claus; Bozec, Alexandra; Canuto, Vittorio M.; Cassou, Christophe; Chassignet, Eric; Coward, Andrew C.; Danilov, Sergey; Diansky, Nikolay; Drange, Helge; Farneti, Riccardo; Fernandez, Elodie; Fogli, Pier Giuseppe; Forget, Gael; Fujii, Yosuke; Griffies, Stephen M.; Gusev, Anatoly; Heimbach, Patrick; Howard, Armando; Ilicak, Mehmet; Jung, Thomas; Karspeck, Alicia R.; Kelley, Maxwell; Large, William G.; Leboissetier, Anthony; Lu, Jianhua; Madec, Gurvan; Marsland, Simon J.; Masina, Simona; Navarra, Antonio; Nurser, A. J. George; Pirani, Anna; Romanou, Anastasia; Salas y Mélia, David; Samuels, Bonita L.; Scheinert, Markus; Sidorenko, Dmitry; Sun, Shan; Treguier, Anne-Marie; Tsujino, Hiroyuki; Uotila, Petteri; Valcke, Sophie; Voldoire, Aurore; Wang, Qiang; Yashayaev, Igor

    2016-01-01

    Simulated inter-annual to decadal variability and trends in the North Atlantic for the 1958-2007 period from twenty global ocean - sea-ice coupled models are presented. These simulations are performed as contributions to the second phase of the Coordinated Ocean-ice Reference Experiments (CORE-II). The study is Part II of our companion paper (Danabasoglu et al., 2014) which documented the mean states in the North Atlantic from the same models. A major focus of the present study is the representation of Atlantic meridional overturning circulation (AMOC) variability in the participating models. Relationships between AMOC variability and those of some other related variables, such as subpolar mixed layer depths, the North Atlantic Oscillation (NAO), and the Labrador Sea upper-ocean hydrographic properties, are also investigated. In general, AMOC variability shows three distinct stages. During the first stage that lasts until the mid- to late-1970s, AMOC is relatively steady, remaining lower than its long-term (1958-2007) mean. Thereafter, AMOC intensifies with maximum transports achieved in the mid- to late-1990s. This enhancement is then followed by a weakening trend until the end of our integration period. This sequence of low frequency AMOC variability is consistent with previous studies. Regarding strengthening of AMOC between about the mid-1970s and the mid-1990s, our results support a previously identified variability mechanism where AMOC intensification is connected to increased deep water formation in the subpolar North Atlantic, driven by NAO-related surface fluxes. The simulations tend to show general agreement in their temporal representations of, for example, AMOC, sea surface temperature (SST), and subpolar mixed layer depth variabilities. In particular, the observed variability of the North Atlantic SSTs is captured well by all models. These findings indicate that simulated variability and trends are primarily dictated by the atmospheric datasets which

  18. Root-associated fungi of Vaccinium carlesii in subtropical forests of China: intra- and inter-annual variability and impacts of human disturbances

    PubMed Central

    Zhang, Yanhua; Ni, Jian; Tang, Fangping; Pei, Kequan; Luo, Yiqi; Jiang, Lifen; Sun, Lifu; Liang, Yu

    2016-01-01

    Ericoid mycorrhiza (ERM) are expected to facilitate establishment of ericaceous plants in harsh habitats. However, diversity and driving factors of the root-associated fungi of ericaceous plants are poorly understood. In this study, hair-root samples of Vaccinium carlesii were taken from four forest types: old growth forests (OGF), secondary forests with once or twice cutting (SEC I and SEC II), and Cunninghamia lanceolata plantation (PLF). Fungal communities were determined using high-throughput sequencing, and impacts of human disturbances and the intra- and inter-annual variability of root-associated fungal community were evaluated. Diverse fungal taxa were observed and our results showed that (1) Intra- and inter-annual changes in root-associated fungal community were found, and the Basidiomycota to Ascomycota ratio was related to mean temperature of the sampling month; (2) Human disturbances significantly affected structure of root-associated fungal community of V. carlesii, and two secondary forest types were similar in root-associated fungal community and were closer to that of the old growth forest; (3) Plant community composition, edaphic parameters, and geographic factors significantly affected root-associated fungal communities of V. carlesii. These results may be helpful in better understanding the maintenance mechanisms of fungal diversity associated with hair roots of ERM plants under human disturbances. PMID:26928608

  19. Differential Annual Movement Patterns in a Migratory Species: Effects of Experience and Sexual Maturation

    PubMed Central

    Jorge, Paulo E.; Sowter, David; Marques, Paulo A. M.

    2011-01-01

    Some animals migrate long distances to exploit important seasonal food resources in the northern regions of the northern hemisphere, whilst avoiding winter starvation. Changes in the individual's age and navigational skills are likely to affect migration, which in turn influences the geographic distribution of individuals. Processes such as sexual maturation and navigational abilities are affected by age, and age is thus a key factor in understanding migration patterns and differences in distribution ranges. In the present study, we investigated the effects of age on the geographic distribution of a population of Lesser Black-backed Gulls Larus fuscus throughout its annual cycle, by analyzing a dataset of 19,096 records from 10,000 color-ringed gulls. In contrast to previous assumptions, the results showed that gulls were geographically segregated by age throughout the entire annual cycle, rather than showing a geographic age-related cline only in the wintering areas. This asymmetric distribution results from a reduction in the annual range of sexually mature gulls, and the differential distribution of mature and immature individuals (mature birds remained in more northern areas, compared to immature birds, throughout the annual cycle). Furthermore, although immature gulls travelled longer distances than adults, they initiated their fall migration with short movements, in contrast to adults that migrated using longer movements. The effects identified in this study explain the non-homogenous distribution of populations throughout the annual cycle, with wide implications for the development of effective human health policies and/or wildlife management strategies. PMID:21799853

  20. Evaluation of spatial productivity patterns in an annual grassland during an AVIRIS overflight

    NASA Technical Reports Server (NTRS)

    Gamon, John A.; Field, Christopher B.; Ustin, Susan L.

    1992-01-01

    In May 1991, coincident with an Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) overflight, a ground-based study covering 9 hectares of an annual grassland was completed. There were two goals of this ground study: (1) obtain ecologically and physiologically meaningful data for relating AVIRIS images to canopy structure, biochemistry, and physiology; and (2) evaluate the suitability of the 20-m AVIRIS pixel size for depicting detailed spatial patterns of productivity.

  1. Seasonal, inter-annual and solar cycle variability of the quasi two day wave in the low-latitude mesosphere and lower thermosphere

    NASA Astrophysics Data System (ADS)

    Rao, N. Venkateswara; Ratnam, M. Venkat; Vedavathi, C.; Tsuda, T.; Murthy, B. V. Krishna; Sathishkumar, S.; Gurubaran, S.; Kumar, K. Kishore; Subrahmanyam, K. V.; Rao, S. Vijaya Bhaskara

    2017-01-01

    We analyzed 17 years (1993-2009) of horizontal winds measured by the medium frequency (MF) radar located at Tirunelveli (8.7°N, 77.8°E) and 10 years (2005-2014) of horizontal winds measured by a meteor radar located at Thumba (8.5°N, 77°E) to examine the seasonal, inter-annual, and solar cycle variability of the Quasi-Two Day Wave (QTDW) in the mesosphere and lower thermosphere region. These two radars are nearly co-located, but differ in their measurement technique. Comparison of the estimated QTDW amplitudes by the two radars shows that the amplitudes are larger in the meteor radar than those in the MF radar. The difference between the amplitudes is larger in May in the zonal component and in April and September in the meridional one. Furthermore, the differences are larger in the meridional component. The QTDWs in both the radars show a strong semi-annual oscillation (SAO). In addition, the meridional QTDW amplitudes of both the MF and meteor radars show a distinct enhancement in the month of October. While the whole spectra of QTDWs contribute to the SAO amplitudes, only 45-50 h waves contribute to the October enhancement. The amplitudes of the QTDWs, in general, show large inter-annual variability. The QTDW amplitudes from both the radars show modulation at period of quasi-biennial oscillation. The QTDWs of the MF radar show a small negative correlation with solar activity while those of meteor radar do not show any correlation. The above aspects are discussed in the light of current understanding of the QTDWs.

  2. Impact of intra- versus inter-annual snow depth variation on water relations and photosynthesis for two Great Basin Desert shrubs.

    PubMed

    Loik, Michael E; Griffith, Alden B; Alpert, Holly; Concilio, Amy L; Wade, Catherine E; Martinson, Sharon J

    2015-06-01

    Snowfall provides the majority of soil water in certain ecosystems of North America. We tested the hypothesis that snow depth variation affects soil water content, which in turn drives water potential (Ψ) and photosynthesis, over 10 years for two widespread shrubs of the western USA. Stem Ψ (Ψ stem) and photosynthetic gas exchange [stomatal conductance to water vapor (g s), and CO2 assimilation (A)] were measured in mid-June each year from 2004 to 2013 for Artemisia tridentata var. vaseyana (Asteraceae) and Purshia tridentata (Rosaceae). Snow fences were used to create increased or decreased snow depth plots. Snow depth on +snow plots was about twice that of ambient plots in most years, and 20 % lower on -snow plots, consistent with several down-scaled climate model projections. Maximal soil water content at 40- and 100-cm depths was correlated with February snow depth. For both species, multivariate ANOVA (MANOVA) showed that Ψ stem, g s, and A were significantly affected by intra-annual variation in snow depth. Within years, MANOVA showed that only A was significantly affected by spatial snow depth treatments for A. tridentata, and Ψ stem was significantly affected by snow depth for P. tridentata. Results show that stem water relations and photosynthetic gas exchange for these two cold desert shrub species in mid-June were more affected by inter-annual variation in snow depth by comparison to within-year spatial variation in snow depth. The results highlight the potential importance of changes in inter-annual variation in snowfall for future shrub photosynthesis in the western Great Basin Desert.

  3. Inter-decadal patterns of population and dietary change in sea otters at Amchitka Island, Alaska

    USGS Publications Warehouse

    Watt, J.; Siniff, D.B.; Estes, J.A.

    2000-01-01

    After having been hunted to near-extinction in the Pacific maritime fur trade, the sea otter population at Amchitka Island, Alaska increased from very low numbers in the early 1900s to near equilibrium density by the 1940s. The population persisted at or near equilibrium through the 1980s, but declined sharply in the 1990s in apparent response to increased killer whale predation. Sea otter diet and foraging behavior were studied at Amchitka from August 1992 to March 1994 and the data compared with similar information obtained during several earlier periods. In contrast with dietary patterns in the 1960s and 1970s, when the sea otter population was at or near equilibrium density and kelp-forest fishes were the dietary mainstay, these fishes were rarely eaten in the 1990s. Benthic invertebrates, particularly sea urchins, dominated the otter's diet from early summer to midwinter, then decreased in importance during late winter and spring when numerous Pacific smooth lumpsuckers (a large and easily captured oceanic fish) were eaten. The occurrence of spawning lumpsuckers in coastal waters apparently is episodic on a scale of years to decades. The otters' recent dietary shift away from kelp-forest fishes is probably a response to the increased availability of lumpsuckers and sea urchins (both high-preference prey). Additionally, increased urchin densities have reduced kelp beds, thus further reducing the availability of kelp-forest fishes. Our findings suggest that dietary patterns reflect changes in population status and show how an ecosystem normally under top-down control and limited by coastal zone processes can be significantly perturbed by exogenous events.

  4. Climate effects on inter- and intra-annual larch stemwood anomalies in the Mongolian forest-steppe

    NASA Astrophysics Data System (ADS)

    Khishigjargal, Mookhor; Dulamsuren, Choimaa; Leuschner, Hanns Hubert; Leuschner, Christoph; Hauck, Markus

    2014-02-01

    Climate response of tree-ring width and intra-annual wood anomalies were studied in stands of Siberian larch (Larix sibirica) on Mt. Bogd Uul in the forest-steppe ecotone of Mongolia. Climate on Mt. Bogd Uul is characterized by an increase of the annual mean temperature by 1.5 K between 1965 and 2007, the lack of a long-term trend for annual precipitation and, with it, an increase in aridity. Tree-ring width increases with increasing June precipitation of the current year (June) and increasing late summer precipitation of the previous year. In >100-year old trees, also a negative correlation of tree-ring width with the July temperature of the year prior to tree-ring formation was found. Decreasing tree-ring width with increasing snowfall in December can be explained with the protection of the frost-sensitive eggs of gypsy moth by snow cover, which is a major herbivore of larch in Mongolia and causes reduction in the annual stem increment. The most significant change in wood anatomy was the decline of wide latewood, which is attributable to the increase of summer days with a mean temperature > 15 °C and drought periods in summer without precipitation. Increasing summer drought is also thought to have caused the repeated occurrence of missing rings since the 1960s, which were not observed in the late 19th and early 20th centuries.

  5. Inter vs. intraglycosidic acetal linkages control sulfation pattern in semi-synthetic chondroitin sulfate.

    PubMed

    Laezza, Antonio; De Castro, Cristina; Parrilli, Michelangelo; Bedini, Emiliano

    2014-11-04

    Microbial-sourced unsulfated chondroitin could be converted into chondroitin sulfate (CS) polysaccharide by a multi-step strategy relying upon benzylidenation and acetylation reactions as key-steps for its regioselective protection. By conducting the two reactions one- or two-pots, CSs with different sulfation patterns could be obtained at the end of the semi-synthesis. In particular, a CS polysaccharide possessing sulfate groups randomly distributed between positions 4 and 6 of N-acetyl-galactosamine (GalNAc) units could be obtained through the two-pots route, whereas the one-pot pathway allowed an additional sulfation at position 3 of some glucuronic acid (GlcA) units. This difference was ascribed to the stabilization of a labile interglycosidic benzylidene acetal involving positions O-3 and O-6 of some GlcA and GalNAc, respectively, when the benzylidene-acetylation reactions were conducted in a one-pot fashion. Isolation and characterization of a polysaccharide intermediate showing interglycosidic acetal moieties was accomplished.

  6. Inter-annual Variability of Biomass Burning Aerosol Optical Depth in Southern Amazonia, and the Impact of These Aerosols on the Diurnal Cycle of Solar Flux Reduction

    NASA Astrophysics Data System (ADS)

    Eck, T. F.; Holben, B. N.; Schafer, J. S.; Artaxo, P.; Yamasoe, M. A.; Procopio, A. S.; Prins, E. M.; Feltz, J. M.; Smirnov, A.; Dubovik, O.; Reid, J. S.

    2002-12-01

    The inter-annual variability of the magnitude of biomass burning in southern Amazonia has been relatively large over the last decade. The extent of the burning in the latter half of a given dry season (July-October) depends largely on the rainfall amount and timing, with drought years exhibiting many more fires and smoke than average. Additionally, new regulations aimed at controlling burning may also affect inter-annual variability. We present measurements of aerosol optical depth (AOD) from biomass burning smoke as measured by AERONET sites in Rondonia and Mato Grosso from 1993-2002. These AOD measurements are shown to follow similar inter-annual variability as the fire counts determined by the multi-spectral radiance measurements obtained with GOES-8. However, the AOD at these sites exhibit relatively little diurnal variation despite a very large diurnal cycle in satellite detected fire counts. In order to quantify the changes in the diurnal cycle of solar flux reduction as a result of aerosol attenuation at the peak of the burning season, we model the diurnal cycle of total shortwave (SW; 300-4000 nm), photosynthetically active radiation (PAR; 400-700 nm), and Ultraviolet- A (UVA; 320-400 nm) fluxes in mid-September using the AERONET monthly average AOD measurements (AOD(550 nm) = 1.11). These average diurnal cycle flux reductions show significant temporal delays in the morning for equivalent flux levels in all three spectral bands, of ~50 min to 2 hr 15 min at mid-morning (midpoint between sunrise and solar noon). The largest time delays in flux occur in the UVA band and the smallest in the total SW broadband due to a rapid decrease in AOD as wavelength increases for the accumulation mode smoke aerosols. The time delays in solar flux have implications for possible delay of the onset of cumulus convection, the shortening of the photo-period when plants photosynthesize, and reduced time interval for UVA fluxes which may have implications for photochemical

  7. Soil wetting patterns of vegetation and inter-patches following single and repeated wildfires

    NASA Astrophysics Data System (ADS)

    González, Óscar; Malvar, Maruxa; van den Elsen, Erik; Hosseini, mohammadreza; Coelho, Celeste; Ritsema, Coen; Bautista, Susana; Keizer, Jan Jacob; Cerdà, Artemi

    2015-04-01

    Although wildfires spread in Mediterranean areas are considered a natural processes, the expected increase in fire frequency has raised concerns about the systems' future resilience (Pausas, 2004). Besides more frequent, future wildfires can become more severe and produce more pronounced changes in topsoil properties, vegetation and litter (Cerdá and Mataix-Solera, 2009). To deal with challenges, the EU funded CASCADE and RECARE projects, which are currently assessing soil threats and tipping-points for land degradation in a climatic gradient across Europe. The present research was developed in Portugal and aims to find relationships between fire frequency and soil wetting patterns following single versus repeated wildfires. In September 2012, a wildfire burnt 3000 ha. of Pine stands and shrub vegetation in the vicinity of Viseu district, North-Central Portugal. Analyses according to the available burnt-area maps (1975-2012), discriminated areas that has been burned 1x (called SD) and 4x (called D) times. In order to evaluate the post-fire soil surface moisture patterns, 6 slopes (3 in SD and 3 in D) were selected and a balanced experimental design with 72 soil moisture sensors (EC5 and GS3, from Decagon devices) was implemented under shrubs (n=18) and on bare (n=18) soil environments, at 2.5 cm and 7.5 cm soil depth each. The spatio-temporal occurrence of soil water repellence (SWR) (Keizer et al., 2008; Prats et al., 2013; Santos et al., 2014) was monthly assessed through the MED test at 2.5 cm and 7.5 cm soil depth into 5 sampling points located at regular distances along a transect running from the top to bottom of a selected slope in SD and D. Automatic and totalize rainfall gauges were also installed across the study area. Preliminary results showed that soil wetting patterns and SWR occurrence differs between SD, D sites and, between soil environment (under shrubs and on bare soil areas). SWR were more pronounced on the SD than in D, affecting soil wetting

  8. Inter-nesting habitat-use patterns of loggerhead sea turtles: Enhancing satellite tracking with benthic mapping

    USGS Publications Warehouse

    Hart, Kristen M.; Zawada, David G.; Fujisaki, Ikuko; Lidz, Barbara H.

    2010-01-01

    The loggerhead sea turtle Caretta caretta faces declining nest numbers and bycatches from commercial longline fishing in the southeastern USA. Understanding spatial and temporal habitat-use patterns of these turtles, especially reproductive females in the neritic zone, is critical for guiding management decisions. To assess marine turtle habitat use within the Dry Tortugas National Park (DRTO), we used satellite telemetry to identify core-use areas for 7 loggerhead females inter-nesting and tracked in 2008 and 2009. This effort represents the first tracking of DRTO loggerheads, a distinct subpopulation that is 1 of 7 recently proposed for upgrading from threatened to endangered under the US Endangered Species Act. We also used a rapid, high-resolution, digital imaging system to map benthic habitats in turtle core-use areas (i.e. 50% kernel density zones). Loggerhead females were seasonal residents of DRTO for 19 to 51 d, and individual inter-nesting habitats were located within 1.9 km (2008) and 2.3 km (2009) of the nesting beach and tagging site. The core area common to all tagged turtles was 4.2 km2 in size and spanned a depth range of 7.6 to 11.5 m. Mapping results revealed the diversity and distributions of benthic cover available in the core-use area, as well as a heavily used corridor to/from the nesting beach. This combined tagging-mapping approach shows potential for planning and improving the effectiveness of marine protected areas and for developing spatially explicit conservation plans.

  9. Tropospheric ozone trends and carbon monoxide inter-annual variabilities using MOZAIC data (O3 from 1994-2007, CO from 2002-2007).

    NASA Astrophysics Data System (ADS)

    Zbinden, R. M.; Cammas, J.-P.; Thouret, V.; Nédélec, P.

    2009-04-01

    MOZAIC program (Marenco al, 1998) is performing 13 years of very accurate O3, H2O measurements and 6 years for CO with the support of airliners on commercial aircraft. Data from take off and landing for 3 clusters of airports over Germany, East of U.S.A. and Japan with more than 21000 vertical profiles all together and a 50m resolution from ground to 11 km altitude are selected to derive tropospheric ozone trends and on a shorter period carbon monoxide tropospheric inter annual variabilities. Methodology to access to tropospheric columns as defined in Zbinden et al. (2006) is improved here by taking into account an estimation of the MOZAIC unvisited tropospheric layer up when the tropopause is not reach by the aircraft during ascent or descent phase. As tropospheric ozone trend is sensitive to tropopause altitude we try to estimate its impact on tropospheric column contents. Defined as the 2pvu potential vorticity surface, we notice a tropopause general increase over the period from +140m over Germany to +680m over Japan and a winter decrease from -80 to -200m. On one hand, trends from tropospheric O3 monthly time-series are always positive for O3 in the range [+0.9, +1.1 %/year] and on the other hand CO inter-annual variabilities are always negative in the range [-2.2, -2.8%/year]. Discussion about stratospheric intrusion contents as pure tropospheric air mass will be excluded from this presentation. Seasonal aspect of O3 tropospheric trends exhibits a winter-spring major increase [+0.7, +1.5 %/year] and a minor summer-fall increase [0,+0.8 %/year]. CO inter-annual variabilities seem highly decreasing during summer-fall [-4.5, -1.5 %/year] and during winter-spring inter-annual variabilities is found a minor lessening is in the range [0, -2.6%/year]. Contribution of boundary layer, mid-troposphere and upper-troposphere to the tropospheric trends will be detailed. We will also underline the influence of the observational time with a special focus on Germany, most

  10. Establishment of woody riparian vegetation in relation to annual patterns of streamflow, Bill Williams River, Arizona

    USGS Publications Warehouse

    Shafroth, P.B.; Auble, G.T.; Stromberg, J.C.; Patten, D.T.

    1998-01-01

    Previous studies have revealed the close coupling of components of annual streamflow hydrographs and the germination and establishment of Populus species. Key hydrograph components include the timing and magnitude of flood peaks, the rate of decline of the recession limb, and the magnitude of base flows. In this paper, we retrospectively examine establishment of four woody riparian species along the Bill Williams River, Arizona, USA, in the context of annual patterns of streamflow for the years 1993-1995. The four species examined were the native Populus fremontii, Salix gooddingii, and Baccharis salicifolia and the exotic Tamarix ramosissima. We modeled locations suitable for germination of each species along eight study transects by combining historic discharge data, calculated stage-discharge relationships, and seed-dispersal timing observations. This germination model was a highly significant predictor of seedling establishment. Where germination was predicted to occur, we compared values of several environmental variables in quadrats where we observed successful establishment with quadrats where establishment was unsuccessful. The basal area of mature woody vegetation, the maximum annual depth to ground water, and the maximum rate of water-table decline were the variables that best discriminated between quadrats with and without seedlings. The results of this study suggest that the basic components of models that relate establishment of Populus spp. to annual patterns of streamflow may also be applicable to other woody riparian species. Reach-to-reach variation in stage-discharge relationships can influence model parameters, however, and should be considered if results such as ours are to be used in efforts to prescribe reservoir releases to promote establishment of native riparian vegetation.

  11. Sea level anomaly on the Patagonian continental shelf: Trends, annual patterns and geostrophic flows.

    PubMed

    Ruiz Etcheverry, L A; Saraceno, M; Piola, A R; Strub, P T

    2016-04-01

    We study the annual patterns and linear trend of satellite sea level anomaly (SLA) over the southwest South Atlantic continental shelf (SWACS) between 54ºS and 36ºS. Results show that south of 42°S the thermal steric effect explains nearly 100% of the annual amplitude of the SLA, while north of 42°S it explains less than 60%. This difference is due to the halosteric contribution. The annual wind variability plays a minor role over the whole continental shelf. The temporal linear trend in SLA ranges between 1 and 5 mm/yr (95% confidence level). The largest linear trends are found north of 39°S, at 42°S and at 50°S. We propose that in the northern region the large positive linear trends are associated with local changes in the density field caused by advective effects in response to a southward displacement of the South Atlantic High. The causes of the relative large SLA trends in two southern coastal regions are discussed as a function meridional wind stress and river discharge. Finally, we combined the annual cycle of SLA with the mean dynamic topography to estimate the absolute geostrophic velocities. This approach provides the first comprehensive description of the seasonal component of SWACS circulation based on satellite observations. The general circulation of the SWACS is northeastward with stronger/weaker geostrophic currents in austral summer/winter. At all latitudes, geostrophic velocities are larger (up to 20 cm/s) close to the shelf-break and decrease toward the coast. This spatio-temporal pattern is more intense north of 45°S.

  12. Sea level anomaly on the Patagonian continental shelf: Trends, annual patterns and geostrophic flows

    PubMed Central

    Saraceno, M.; Piola, A. R.; Strub, P. T.

    2016-01-01

    Abstract We study the annual patterns and linear trend of satellite sea level anomaly (SLA) over the southwest South Atlantic continental shelf (SWACS) between 54ºS and 36ºS. Results show that south of 42°S the thermal steric effect explains nearly 100% of the annual amplitude of the SLA, while north of 42°S it explains less than 60%. This difference is due to the halosteric contribution. The annual wind variability plays a minor role over the whole continental shelf. The temporal linear trend in SLA ranges between 1 and 5 mm/yr (95% confidence level). The largest linear trends are found north of 39°S, at 42°S and at 50°S. We propose that in the northern region the large positive linear trends are associated with local changes in the density field caused by advective effects in response to a southward displacement of the South Atlantic High. The causes of the relative large SLA trends in two southern coastal regions are discussed as a function meridional wind stress and river discharge. Finally, we combined the annual cycle of SLA with the mean dynamic topography to estimate the absolute geostrophic velocities. This approach provides the first comprehensive description of the seasonal component of SWACS circulation based on satellite observations. The general circulation of the SWACS is northeastward with stronger/weaker geostrophic currents in austral summer/winter. At all latitudes, geostrophic velocities are larger (up to 20 cm/s) close to the shelf‐break and decrease toward the coast. This spatio‐temporal pattern is more intense north of 45°S. PMID:27840784

  13. Soil moisture redistribution and its effect on inter-annual active layer temperature and thickness variations in a dry loess terrace in Adventdalen, Svalbard

    NASA Astrophysics Data System (ADS)

    Schuh, Carina; Frampton, Andrew; Hvidtfeldt Christiansen, Hanne

    2017-02-01

    High-resolution field data for the period 2000-2014 consisting of active layer and permafrost temperature, active layer soil moisture, and thaw depth progression from the UNISCALM research site in Adventdalen, Svalbard, is combined with a physically based coupled cryotic and hydrogeological model to investigate active layer dynamics. The site is a loess-covered river terrace characterized by dry conditions with little to no summer infiltration and an unsaturated active layer. A range of soil moisture characteristic curves consistent with loess sediments is considered and their effects on ice and moisture redistribution, heat flux, energy storage through latent heat transfer, and active layer thickness is investigated and quantified based on hydro-climatic site conditions. Results show that soil moisture retention characteristics exhibit notable control on ice distribution and circulation within the active layer through cryosuction and are subject to seasonal variability and site-specific surface temperature variations. The retention characteristics also impact unfrozen water and ice content in the permafrost. Although these effects lead to differences in thaw progression rates, the resulting inter-annual variability in active layer thickness is not large. Field data analysis reveals that variations in summer degree days do not notably affect the active layer thaw depths; instead, a cumulative winter degree day index is found to more significantly control inter-annual active layer thickness variation at this site. A tendency of increasing winter temperatures is found to cause a general warming of the subsurface down to 10 m depth (0.05 to 0.26 °C yr-1, observed and modelled) including an increasing active layer thickness (0.8 cm yr-1, observed and 0.3 to 0.8 cm yr-1, modelled) during the 14-year study period.

  14. Inter-annual variability of NDVI in response to long-term warming and fertilization in wet sedge and tussock tundra.

    PubMed

    Boelman, Natalie T; Stieglitz, Marc; Griffin, Kevin L; Shaver, Gaius R

    2005-05-01

    This study explores the relationship between the normalized difference vegetation index (NDVI) and aboveground plant biomass for tussock tundra vegetation and compares it to a previously established NDVI-biomass relationship for wet sedge tundra vegetation. In addition, we explore inter-annual variation in NDVI in both these contrasting vegetation communities. All measurements were taken across long-term experimental treatments in wet sedge and tussock tundra communities at the Toolik Lake Long Term Ecological Research (LTER) site, in northern Alaska. Over 15 years (for wet sedge tundra) and 14 years (for tussock tundra), N and P were applied in factorial experiments (N, P and N+P), air temperature was increased using greenhouses with and without N+P fertilizer, and light intensity was reduced by 50% using shade cloth. during the peak growing seasons of 2001, 2002, and 2003, NDVI measurements were made in both the wet sedge and tussock tundra experimental treatment plots, creating a 3-year time series of inter-annual variation in NDVI. We found that: (1) across all tussock experimental tundra treatments, NDVI is correlated with aboveground plant biomass (r2 = 0.59); (2) NDVI-biomass relationships for tussock and wet sedge tundra communities are community specific, and; (3) NDVI values for tussock tundra communities are typically, but not always, greater than for wet sedge tundra communities across all experimental treatments. We suggest that differences between the response of wet sedge and tussock tundra communities in the same experimental treatments result from the contrasting degree of heterogeneity in species and functional types that characterize each of these Arctic tundra vegetation communities.

  15. The effect of inter-annual variability of consumption, production, trade and climate on crop-related green and blue water footprints and inter-regional virtual water trade: A study for China (1978-2008).

    PubMed

    Zhuo, La; Mekonnen, Mesfin M; Hoekstra, Arjen Y

    2016-05-01

    Previous studies into the relation between human consumption and indirect water resources use have unveiled the remote connections in virtual water (VW) trade networks, which show how communities externalize their water footprint (WF) to places far beyond their own region, but little has been done to understand variability in time. This study quantifies the effect of inter-annual variability of consumption, production, trade and climate on WF and VW trade, using China over the period 1978-2008 as a case study. Evapotranspiration, crop yields and green and blue WFs of crops are estimated at a 5 × 5 arc-minute resolution for 22 crops, for each year in the study period, thus accounting for climate variability. The results show that crop yield improvements during the study period helped to reduce the national average WF of crop consumption per capita by 23%, with a decreasing contribution to the total from cereals and increasing contribution from oil crops. The total consumptive WFs of national crop consumption and crop production, however, grew by 6% and 7%, respectively. By 2008, 28% of total water consumption in crop fields in China served the production of crops for export to other regions and, on average, 35% of the crop-related WF of a Chinese consumer was outside its own province. Historically, the net VW within China was from the water-rich South to the water-scarce North, but intensifying North-to-South crop trade reversed the net VW flow since 2000, which amounted 6% of North's WF of crop production in 2008. South China thus gradually became dependent on food supply from the water-scarce North. Besides, during the whole study period, China's domestic inter-regional VW flows went dominantly from areas with a relatively large to areas with a relatively small blue WF per unit of crop, which in 2008 resulted in a trade-related blue water loss of 7% of the national total blue WF of crop production. The case of China shows that domestic trade, as governed by

  16. Parental Choice of Schooling, Learning Processes and Inter-Ethnic Friendship Patterns: The Case of Malay Students in Chinese Primary Schools in Malaysia

    ERIC Educational Resources Information Center

    Sua, Tan Yao; Ngah, Kamarudin; Darit, Sezali Md.

    2013-01-01

    This study surveys 200 Malay students enrolled in three Chinese primary schools in relation to three issues, i.e., parental choice of schooling, learning processes and inter-ethnic friendship patterns. The three issues are explored through a combination of quantitative and qualitative research methodologies. Parental expectations for their…

  17. Influence of seasonal and inter-annual hydro-meteorological variability on surface water fecal coliform concentration under varying land-use composition.

    PubMed

    St Laurent, Jacques; Mazumder, Asit

    2014-01-01

    Quantifying the influence of hydro-meteorological variability on surface source water fecal contamination is critical to the maintenance of safe drinking water. Historically, this has not been possible due to the scarcity of data on fecal indicator bacteria (FIB). We examined the relationship between hydro-meteorological variability and the most commonly measured FIB, fecal coliform (FC), concentration for 43 surface water sites within the hydro-climatologically complex region of British Columbia. The strength of relationship was highly variable among sites, but tended to be stronger in catchments with nival (snowmelt-dominated) hydro-meteorological regimes and greater land-use impacts. We observed positive relationships between inter-annual FC concentration and hydro-meteorological variability for around 50% of the 19 sites examined. These sites are likely to experience increased fecal contamination due to the projected intensification of the hydrological cycle. Seasonal FC concentration variability appeared to be driven by snowmelt and rainfall-induced runoff for around 30% of the 43 sites examined. Earlier snowmelt in nival catchments may advance the timing of peak contamination, and the projected decrease in annual snow-to-precipitation ratio is likely to increase fecal contamination levels during summer, fall, and winter among these sites. Safeguarding drinking water quality in the face of such impacts will require increased monitoring of FIB and waterborne pathogens, especially during periods of high hydro-meteorological variability. This data can then be used to develop predictive models, inform source water protection measures, and improve drinking water treatment.

  18. Inter- and intra-annual variation of water footprint of crops and blue water scarcity in the Yellow River basin (1961-2009)

    NASA Astrophysics Data System (ADS)

    Zhuo, La; Mekonnen, Mesfin M.; Hoekstra, Arjen Y.; Wada, Yoshihide

    2016-01-01

    The Yellow River Basin (YRB), the second largest river basin of China, has experienced a booming agriculture over the past decades. But data on variability of and trends in water consumption, pollution and scarcity in the YRB are lacking. We estimate, for the first time, the inter- and intra-annual water footprint (WF) of crop production in the YRB for the period 1961-2009 and the variation of monthly scarcity of blue water (ground and surface water) for 1978-2009, by comparing the blue WF of agriculture, industry and households in the basin to the maximum sustainable level. Results show that the average overall green (from rainfall) and blue (from irrigation) WFs of crops in the period 2001-2009 were 14% and 37% larger, respectively, than in the period 1961-1970. The annual nitrogen- and phosphorus-related grey WFs (water required to assimilate pollutants) of crop production grew by factors of 24 and 36, respectively. The green-blue WF per ton of crop reduced significantly due to improved crop yields, while the grey WF increased because of the growing application of fertilizers. The ratio of blue to green WF increased during the study period resulting from the expansion of irrigated agriculture. In the period 1978-2009, the annual total blue WFs related to agriculture, industry and households varied between 19% and 52% of the basin's natural runoff. The blue WF in the YRB generally peaks around May-July, two months earlier than natural peak runoff. On average, the YRB faced moderate to severe blue water scarcity during seven months (January-July) per year. Even in the wettest month in a wet year, about half of the area of the YRB still suffered severe blue water scarcity, especially in the basin's northern part.

  19. The dynamics of avian influenza in Lesser Snow Geese: implications for annual and migratory infection patterns.

    PubMed

    Samuel, Michael D; Hall, Jeffrey S; Brown, Justin D; Goldberg, Diana R; Ip, Hon; Baranyuk, Vasily V

    2015-10-01

    Wild water birds are the natural reservoir for low-pathogenic avian influenza viruses (AIV). However, our ability to investigate the epizootiology of AIV in these migratory populations is challenging and, despite intensive worldwide surveillance, remains poorly understood. We conducted a cross-sectional, retrospective analysis in Pacific Flyway Lesser Snow Geese, Chen caerulescens, to investigate AIV serology and infection patterns. We collected nearly 3000 sera samples from Snow Geese at two breeding colonies in Russia and Canada during 1993-1996 and swab samples from >4000 birds at wintering and migration areas in the United States during 2006-2011. We found seroprevalence and annual seroconversion varied considerably among years. Seroconversion and infection rates also differed between Snow Goose breeding colonies and wintering areas, suggesting that AIV exposure in this gregarious waterfowl species is likely occurring during several phases (migration, wintering, and potentially breeding areas) of the annual cycle. We estimated AIV antibody persistence was longer (14 months) in female geese compared to males (6 months). This relatively long period of AIV antibody persistence suggests that subtype-specific serology may be an effective tool for detection of exposure to subtypes associated with highly pathogenic AIV. Our study provides further evidence of high seroprevalence in Arctic goose populations, and estimates of annual AIV seroconversion and antibody persistence for North American waterfowl. We suggest future AIV studies include serology to help elucidate the epizootiological dynamics of AIV in wild bird populations.

  20. Inter-annual rainfall variability in the eastern Antilles and coupling with the regional and intra-seasonal circulation

    NASA Astrophysics Data System (ADS)

    Jury, Mark R.

    2016-11-01

    Climate variability in the eastern Antilles island chain is analyzed via principal component analysis of high-resolution monthly rainfall in the period 1981-2013. The second mode reflecting higher rainfall in July-October season between Martinique and Grenada is the focus of this study. Higher rainfall corresponds with a weakened trade wind and boundary current along the southern edge of the Caribbean. This quells the coastal upwelling off Venezuela and builds the freshwater plume east of Trinidad. There is corresponding upper easterly wind flow that intensifies passing tropical waves. During a storm event over the Antilles on 4-5 October 2010, there was inflow from east of Guyana where low salinity and high sea temperatures enable surplus latent heat fluxes. A N-S convective rain band forms ˜500 km east of the cyclonic vortex. Many features at the weather timescale reflect the seasonal correlation and composite difference maps and El Nino Southern Oscillation (ENSO) modulation of oceanic inter-basin transfers.

  1. Satellite-measured seasonal and inter-annual chlorophyll variability in the Northeast Pacific and Coastal Gulf of Alaska

    NASA Astrophysics Data System (ADS)

    Brickley, Peter J.; Thomas, Andrew C.

    2004-01-01

    Four years (September 1997-August 2001) of SeaWiFS ocean-color satellite data are used to present the first synoptic quantification of chlorophyll variability on seasonal and interannual timescales over the Northeast Pacific and Coastal Gulf of Alaska. Low light levels and/or cloud during November-January prevent examination of winter patterns. The climatological seasonal patterns show shelf-intensified chlorophyll (by a factor of 3 or more) around the entire basin, extending up to 300 m beyond the shelfbreak along the eastern margin and south of Kodiak Island, with peaks in May and again but weaker in August-September. Over the central basin, concentrations are minimum in February (<0.4 mg m -3), have no spring peak, and increase steadily over the season to a maximum (˜0.7 mg m -3) in September-October. The dominant mode (27% of total variance) of an empirical orthogonal function (EOF) decomposition of the monthly image time series shows interannual variability is strongest during the spring peak around the periphery of the basin with minima in 1998 and 2001. The second and third modes (8% and 7%) capture additional spring interannual variability in patterns strongly related to the shelfbreak west of Kayak Island (144°W) and in more diffuse mesoscale patterns in the eastern GOA. Cross-shelf chlorophyll variability (0-400 km offshore) at three locations contrasts strong seasonality and spring bloom development offshore, over the shelf break, in the northern GOA (off Seward) with weaker seasonality over the shelf off the Queen Charlotte Islands. The shelf between Prince William Sound and Kodiak Island consistently develops a spring along-shelf gradient in chlorophyll, maximum over the western end of the shelf. Comparisons to wind and surface temperature anomalies suggest that interannual differences in the strength of the spring bloom are more strongly related to wind forcing the previous winter than temperature anomalies associated with the 1997/98 El Nino.

  2. Inter-annual associations between precipitation and human incidence of West Nile virus in the United States.

    PubMed

    Landesman, William J; Allan, Brian F; Langerhans, R Brian; Knight, Tiffany M; Chase, Jonathan M

    2007-01-01

    Higher-than-average precipitation levels may cause mosquito outbreaks if mosquitoes are limited by larval habitat availability. Alternatively, recent ecological research suggests that drought events can lead to mosquito outbreaks the following year due to changes in food web structure. By either mechanism, these mosquito outbreaks may contribute to human cases of West Nile Virus (WNV) in the recent United States outbreak. Using countylevel precipitation and human WNV incidence data (2002-2004), we tested the impacts of above and below-average rainfall on the prevalence of WNV in human populations both within and between years. We found evidence that human WNV incidence is most strongly associated with annual precipitation from the preceding year. Human outbreaks of WNV are preceded by above-average rainfall in the eastern United States and below-average rainfall in the western United States in the prior year. While no direct mechanism may be determined from this study, we hypothesize that differences in the ecology of mosquito vectors may be responsible for the opposite relationships between precipitation and WNV outbreaks between the eastern and western United States.

  3. Annual and seasonal patterns of insect succession on decomposing remains at two locations in Western Australia.

    PubMed

    Voss, Sasha C; Spafford, Helen; Dadour, Ian R

    2009-12-15

    This study considered annual, seasonal and shorter term variation in patterns of insect succession onto decomposing remains at two contrasting locations in Western Australia, bushland and agricultural. The degree of consistency in insect succession patterns over spatial and temporal scales was evaluated through multivariate analysis of occurrence-based distance matrices. Insect assemblages were strongly correlated between locations, within corresponding time periods, indicating that patterns of insect succession were similar between localised sites within the same broad geographic area. This suggests that there is reasonable scope for the application of baseline succession data generated at a single study site to a range of decomposition sites within a given region. Differences were largely due to species absences at the agricultural site. Three species of Coleoptera were identified as possible representatives of bushland habitat, Ptomaphila lacrymosa (Silphidae), Omorgus tatei (Trogidae) and Helea castor (Tenebrionidae), and may be indicative of post mortem movement between habitat types. Within locations, variation in insect assemblages was not significant between years. Within years, insect assemblages varied significantly over time on a seasonal time scale and as decomposition progressed through defined decomposition stages. Forensically relevant data detailing the seasonal pattern of insect succession onto decomposing remains for Western Australia are reported. Additional focus has been directed towards hymenopteran parasitoids that frequent decomposing remains and parasitise Diptera colonisers. Parasitoids can be used to provide an extended PMI timeframe in cases where traditional forensic indicators have completed their development.

  4. Inter- and intra-annual variability of fluvial sediment transport in the proglacial river Riffler Bach (Weißseeferner, Ötztal Alps, Tyrol)

    NASA Astrophysics Data System (ADS)

    Baewert, Henning; Weber, Martin; Morche, David

    2015-04-01

    The hydrology of a proglacial river is strongly affected by glacier melting. Due to glacier retreat the effects of snow melt and rain storms will become more important in future decades. Additionally, the development of periglacial landscapes will play a more important role in the hydrology of proglacial rivers. The importance of paraglacial sediment sources in sediment budgets of glacier forefields is increasing, while the role of glacial erosion is declining. In two consecutive ablation seasons the fluvial sediment transport of the river Riffler Bach in the Kaunertal (Tyrol/Austria) was quantified. The catchment area of this station is 20 km² with an altitudinal range from 1929 m to 3518 m above msl. The "Weißseeferner" glacier (2.34 km² in 2012) is the greatest of the remaining glaciers. An automatic water sampler (AWS 2002) and a probe for water level were installed were installed at the outlet of the catchment. In order to calculate annual stage-discharge-relations, discharge (Q) was repeatedly measured with current meters. Concurrent to the discharge measurements bed load was collected using a portable Helley-Smith sampler. Bed load (BL) samples were weighted and sieved in the laboratory to gain annual bed load rating curves and grain size distributions. In 2012, 154 water samples were sampled during 7 periods and subsequently filtered to quantify suspended sediment concentrations (SSC). A Q-SSC-relation was calculated for every period due to the high variability in suspended sediment transport. In addition, the grain size distribution of the filtered material was determined by laser diffraction analysis. In 2013, the same procedure was performed for 232 water samples which were collected during 9 periods. Meteorological data were logged at the climate station "Weißsee", which is located in the centre of the study area. First results show a high variability of discharge and solid sediment transport both at the inter-annual as well as at the intra-annual

  5. Predicting Rift Valley Fever Inter-epidemic Activities and Outbreak Patterns: Insights from a Stochastic Host-Vector Model

    PubMed Central

    Pedro, Sansao A.; Abelman, Shirley; Tonnang, Henri E. Z.

    2016-01-01

    Rift Valley fever (RVF) outbreaks are recurrent, occurring at irregular intervals of up to 15 years at least in East Africa. Between outbreaks disease inter-epidemic activities exist and occur at low levels and are maintained by female Aedes mcintoshi mosquitoes which transmit the virus to their eggs leading to disease persistence during unfavourable seasons. Here we formulate and analyse a full stochastic host-vector model with two routes of transmission: vertical and horizontal. By applying branching process theory we establish novel relationships between the basic reproduction number, R0, vertical transmission and the invasion and extinction probabilities. Optimum climatic conditions and presence of mosquitoes have not fully explained the irregular oscillatory behaviour of RVF outbreaks. Using our model without seasonality and applying van Kampen system-size expansion techniques, we provide an analytical expression for the spectrum of stochastic fluctuations, revealing how outbreaks multi-year periodicity varies with the vertical transmission. Our theory predicts complex fluctuations with a dominant period of 1 to 10 years which essentially depends on the efficiency of vertical transmission. Our predictions are then compared to temporal patterns of disease outbreaks in Tanzania, Kenya and South Africa. Our analyses show that interaction between nonlinearity, stochasticity and vertical transmission provides a simple but plausible explanation for the irregular oscillatory nature of RVF outbreaks. Therefore, we argue that while rainfall might be the major determinant for the onset and switch-off of an outbreak, the occurrence of a particular outbreak is also a result of a build up phenomena that is correlated to vertical transmission efficiency. PMID:28002417

  6. InterVA versus Spectrum: how comparable are they in estimating AIDS mortality patterns in Nairobi's informal settlements?

    PubMed Central

    Oti, Samuel Oji; Wamukoya, Marilyn; Mahy, Mary; Kyobutungi, Catherine

    2013-01-01

    Background The Spectrum computer package is used to generate national AIDS mortality estimates in settings where vital registration systems are lacking. Similarly, InterVA-4 (the latest version of the InterVA programme) is used to estimate cause-of-mortality data in countries where cause-specific mortality data are not available. Objective This study aims to compare trends in adult AIDS-related mortality estimated by Spectrum with trends from the InterVA-4 programme applied to data from a Health and Demographic Surveillance System (HDSS) in Nairobi, Kenya. Design A Spectrum model was generated for the city of Nairobi based on HIV prevalence data for Nairobi and national antiretroviral therapy coverage, underlying mortality, and migration assumptions. We then used data, generated through verbal autopsies, on 1,799 deaths that occurred in the HDSS area from 2003 to 2010 among adults aged 15–59. These data were then entered into InterVA-4 to estimate causes of death using probabilistic modelling. Estimates of AIDS-related mortality rates and all-cause mortality rates from Spectrum and InterVA-4 were compared and presented as annualised trends. Results Spectrum estimated that HIV prevalence in Nairobi was 7%, while the HDSS site measured 12% in 2010. Despite this difference, Spectrum estimated higher levels of AIDS-related mortality. Between 2003 and 2010, the proportion of AIDS-related mortality in Nairobi decreased from 63 to 40% according to Spectrum and from 25 to 16% according to InterVA. The net AIDS-related mortality in Spectrum was closer to the combined mortality rates when AIDS and tuberculosis (TB) deaths were included for InterVA-4. Conclusion Overall trends in AIDS-related deaths from both methods were similar, although the values were closer when TB deaths were included in InterVA. InterVA-4 might not accurately differentiate between TB and AIDS deaths. PMID:24160914

  7. Diversity in plant hydraulic traits explains seasonal and inter-annual variations of vegetation dynamics in seasonally dry tropical forests.

    PubMed

    Xu, Xiangtao; Medvigy, David; Powers, Jennifer S; Becknell, Justin M; Guan, Kaiyu

    2016-10-01

    We assessed whether diversity in plant hydraulic traits can explain the observed diversity in plant responses to water stress in seasonally dry tropical forests (SDTFs). The Ecosystem Demography model 2 (ED2) was updated with a trait-driven mechanistic plant hydraulic module, as well as novel drought-phenology and plant water stress schemes. Four plant functional types were parameterized on the basis of meta-analysis of plant hydraulic traits. Simulations from both the original and the updated ED2 were evaluated against 5 yr of field data from a Costa Rican SDTF site and remote-sensing data over Central America. The updated model generated realistic plant hydraulic dynamics, such as leaf water potential and stem sap flow. Compared with the original ED2, predictions from our novel trait-driven model matched better with observed growth, phenology and their variations among functional groups. Most notably, the original ED2 produced unrealistically small leaf area index (LAI) and underestimated cumulative leaf litter. Both of these biases were corrected by the updated model. The updated model was also better able to simulate spatial patterns of LAI dynamics in Central America. Plant hydraulic traits are intercorrelated in SDTFs. Mechanistic incorporation of plant hydraulic traits is necessary for the simulation of spatiotemporal patterns of vegetation dynamics in SDTFs in vegetation models.

  8. Biogeochemical variations at the Porcupine Abyssal Plain Sustained Observatory (PAP-SO) in the northeast Atlantic Ocean, from weekly to inter-annual time scales

    NASA Astrophysics Data System (ADS)

    Hartman, S. E.; Jiang, Z.-P.; Turk, D.; Lampitt, R. S.; Frigstad, H.; Ostle, C.

    2014-08-01

    We present high-resolution autonomous measurements of carbon dioxide partial pressure p(CO2) taken in situ at the Porcupine Abyssal Plain sustained observatory (PAP-SO) in the Northeast Atlantic (49° N, 16.5° W; water depth of 4850 m) for the period 2010 to 2012. Measurements of p(CO2) made at 30 m depth on a sensor frame are compared with other autonomous biogeochemical measurements at that depth (including chlorophyll a-fluorescence and nitrate concentration data) to analyse weekly to seasonal controls on p(CO2) flux in the inter-gyre region of the North Atlantic. Comparisons are also made with in situ regional time-series data from a ship of opportunity and mixed layer depth (MLD) measurements from profiling Argo floats. There is a persistent under saturation of CO2 in surface waters throughout the year which gives rise to a perennial CO2 sink. Comparison with an earlier dataset collected at the site (2003 to 2005) confirms seasonal and inter-annual changes in surface seawater chemistry. There is year-to-year variability in the timing of stratification and deep winter mixing. The 2010 to 2012 period shows an overall increase in p(CO2) values when compared to the 2003-2005 period. This is despite similar surface temperature, wind speed and MLD measurements between the two periods of time. Future work should incorporate daily CO2 flux measurements made using CO2 sensors at 1 m depth and the in situ wind speed data now available from the UK Met Office Buoy.

  9. Biogeochemical variations at the Porcupine Abyssal Plain Sustained Observatory (PAP-SO) in the northeast Atlantic Ocean, from weekly to inter-annual time scales

    NASA Astrophysics Data System (ADS)

    Hartman, Susan; Lampitt, Richard

    2015-04-01

    We present high-resolution autonomous measurements of carbon dioxide partial pres- sure p(CO2) taken in situ at the Porcupine Abyssal Plain sustained observatory (PAP- SO) in the northeast Atlantic (49N, 16.5W; water depth of 4850 m) for the period 2010 to 2012. Measurements of p(CO2) made at 30 m depth on a sensor frame are compared with other autonomous biogeochemical measurements at that depth (including chlorophyll a-fluorescence and nitrate concentration data) to analyse weekly to seasonal controls on p(CO2) flux in the inter-gyre region of the North Atlantic. Comparisons are also made with in situ regional time-series data from a ship of opportunity and mixed layer depth (MLD) measurements from profiling Argo floats. There is a persistent under saturation of CO2 in surface waters throughout the year which gives rise to a perennial CO2 sink. Comparison with an earlier dataset collected at the site (2003 to 2005) confirms seasonal and inter-annual changes in surface seawater chemistry. There is year-to-year variability in the timing of deep winter mixing and the intensity of the spring bloom. The 2010-2012 period shows an overall increase in p(CO2) values when compared to the 2003-2005 period as would be expected from increases due to anthropogenic CO2 emissions. The surface temperature, wind speed and MLD measurements are similar for both periods of time. Future work should incorporate daily CO2 flux measurements made using CO2 sensors at 1 m depth and the in situ wind speed data now available from the UK Met Office Buoy.

  10. Biogeochemical variations at the Porcupine Abyssal Plain sustained Observatory in the northeast Atlantic Ocean, from weekly to inter-annual timescales

    NASA Astrophysics Data System (ADS)

    Hartman, S. E.; Jiang, Z.-P.; Turk, D.; Lampitt, R. S.; Frigstad, H.; Ostle, C.; Schuster, U.

    2015-02-01

    We present high-resolution autonomous measurements of carbon dioxide partial pressure p(CO2) taken in situ at the Porcupine Abyssal Plain sustained Observatory (PAP-SO) in the northeast Atlantic (49° N, 16.5° W; water depth of 4850 m) for the period 2010-2012. Measurements of p(CO2) made at 30 m depth on a sensor frame are compared with other autonomous biogeochemical measurements at that depth (including chlorophyll a fluorescence and nitrate concentration data) to analyse weekly to seasonal controls on p(CO2) flux in the inter-gyre region of the North Atlantic. Comparisons are also made with in situ regional time series data from a ship of opportunity and mixed layer depth (MLD) measurements from profiling Argo floats. There is a persistent under-saturation of CO2 in surface waters throughout the year which gives rise to a perennial CO2 sink. Comparison with an earlier data set collected at the site (2003-2005) confirms seasonal and inter-annual changes in surface seawater chemistry. There is year-to-year variability in the timing of deep winter mixing and the intensity of the spring bloom. The 2010-2012 period shows an overall increase in p(CO2) values when compared to the 2003-2005 period as would be expected from increases due to anthropogenic CO2 emissions. The surface temperature, wind speed and MLD measurements are similar for both periods of time. Future work should incorporate daily CO2 flux measurements made using CO2 sensors at 1 m depth and the in situ wind speed data now available from the UK Met Office Buoy.

  11. Inter-annual Tropospheric Aerosol Variability in Late Twentieth Century and its Impact on Tropical Atlantic and West African Climate by Direct and Semi-direct Effects

    SciTech Connect

    Evans, Katherine J; Hack, James J; Truesdale, John; Mahajan, Salil; Lamarque, J-F

    2012-01-01

    A new high-resolution (0.9$^{\\circ}$x1.25$^{\\circ}$ in the horizontal) global tropospheric aerosol dataset with monthly resolution is generated using the finite-volume configuration of Community Atmosphere Model (CAM4) coupled to a bulk aerosol model and forced with recent estimates of surface emissions for the latter part of twentieth century. The surface emissions dataset is constructed from Coupled Model Inter-comparison Project (CMIP5) decadal-resolution surface emissions dataset to include REanalysis of TROpospheric chemical composition (RETRO) wildfire monthly emissions dataset. Experiments forced with the new tropospheric aerosol dataset and conducted using the spectral configuration of CAM4 with a T85 truncation (1.4$^{\\circ}$x1.4$^{\\circ}$) with prescribed twentieth century observed sea surface temperature, sea-ice and greenhouse gases reveal that variations in tropospheric aerosol levels can induce significant regional climate variability on the inter-annual timescales. Regression analyses over tropical Atlantic and Africa reveal that increasing dust aerosols can cool the North African landmass and shift convection southwards from West Africa into the Gulf of Guinea in the spring season in the simulations. Further, we find that increasing carbonaceous aerosols emanating from the southwestern African savannas can cool the region significantly and increase the marine stratocumulus cloud cover over the southeast tropical Atlantic ocean by aerosol-induced diabatic heating of the free troposphere above the low clouds. Experiments conducted with CAM4 coupled to a slab ocean model suggest that present day aerosols can shift the ITCZ southwards over the tropical Atlantic and can reduce the ocean mixed layer temperature beneath the increased marine stratocumulus clouds in the southeastern tropical Atlantic.

  12. Evaluating the effects of China's pollution controls on inter-annual trends and uncertainties of atmospheric mercury emissions

    NASA Astrophysics Data System (ADS)

    Zhao, Y.; Zhong, H.; Zhang, J.; Nielsen, C. P.

    2015-04-01

    China's anthropogenic emissions of atmospheric mercury (Hg) are effectively constrained by national air pollution control and energy efficiency policies. In this study, improved methods, based on available data from domestic field measurements, are developed to quantify the benefits of Hg abatement by various emission control measures. Those measures include increased use of (1) flue gas desulfurization (FGD) and selective catalyst reduction (SCR) systems in power generation; (2) precalciner kilns with fabric filters (FF) in cement production; (3) mechanized coking ovens with electrostatic precipitators (ESP) in iron and steel production; and (4) advanced production technologies in nonferrous metal smelting. Investigation reveals declining trends in emission factors for each of these sources, which together drive a much slower growth of total Hg emissions than the growth of China's energy consumption and economy, from 679 metric tons (t) in 2005 to 750 t in 2012. In particular, estimated emissions from the above-mentioned four source types declined 3% from 2005 to 2012, which can be attributed to expanded deployment of technologies with higher energy efficiencies and air pollutant removal rates. Emissions from other anthropogenic sources are estimated to increase by 22% during the period. The species shares of total Hg emissions have been stable in recent years, with mass fractions of around 55, 39, and 6% for gaseous elemental Hg (Hg0), reactive gaseous mercury (Hg2+), and particle-bound mercury (Hgp), respectively. The higher estimate of total Hg emissions than previous inventories is supported by limited simulation of atmospheric chemistry and transport. With improved implementation of emission controls and energy saving, a 23% reduction in annual Hg emissions from 2012 to 2030, to below 600 t, is expected at the most. While growth in Hg emissions has been gradually constrained, uncertainties quantified by Monte Carlo simulation for recent years have increased

  13. The Influences of Drought and Land-Cover Conversion on Inter-Annual Variation of NPP in the Three-North Shelterbelt Program Zone of China Based on MODIS Data

    PubMed Central

    Wu, Chaoyang; Zhang, Bing; Huete, Alfredo; Zhang, Xiaoyang; Sun, Rui; Lei, Liping; Huang, Wenjing; Liu, Liangyun; Liu, Xinjie; Li, Jun; Luo, Shezhou; Fang, Bin

    2016-01-01

    Terrestrial ecosystems greatly contribute to carbon (C) emission reduction targets through photosynthetic C uptake.Net primary production (NPP) represents the amount of atmospheric C fixed by plants and accumulated as biomass. The Three-North Shelterbelt Program (TNSP) zone accounts for more than 40% of China’s landmass. This zone has been the scene of several large-scale ecological restoration efforts since the late 1990s, and has witnessed significant changes in climate and human activities.Assessing the relative roles of different causal factors on NPP variability in TNSP zone is very important for establishing reasonable local policies to realize the emission reduction targets for central government. In this study, we examined the relative roles of drought and land cover conversion(LCC) on inter-annual changes of TNSP zone for 2001–2010. We applied integrated correlation and decomposition analyses to a Standardized Evapotranspiration Index (SPEI) and MODIS land cover dataset. Our results show that the 10-year average NPP within this region was about 420 Tg C. We found that about 60% of total annual NPP over the study area was significantly correlated with SPEI (p<0.05). The LCC-NPP relationship, which is especially evident for forests in the south-central area, indicates that ecological programs have a positive impact on C sequestration in the TNSP zone. Decomposition analysis generally indicated that the contributions of LCC, drought, and other Natural or Anthropogenic activities (ONA) to changes in NPP generally had a consistent distribution pattern for consecutive years. Drought and ONA contributed about 74% and 23% to the total changes in NPP, respectively, and the remaining 3% was attributed to LCC. Our results highlight the importance of rainfall supply on NPP variability in the TNSP zone. PMID:27348303

  14. Numerical simulation of inter-annual variations in the properties of the upper mixed layer in the Black Sea over the last 34 years

    NASA Astrophysics Data System (ADS)

    Shapiro, Georgy I.; Wobus, Fred; Zatsepin, Andrei G.; Akivis, Tatiana M.; Zanacchi, Marcus; Stanichny, Sergey

    2014-05-01

    The Black Sea is a nearly land-locked basin where a combination of salt and heat budgets results in a unique thermohaline water mass structure. An important feature of the Black Sea is that oxygen is dissolved and rich sea life made possible only in the upper water levels. This is due to a strong pycnocline which cannot be mixed even by strong winds or winter convection (Shapiro, 2008). The upper mixed layer (UML) with a nearly uniform temperature profile and a very sharp seasonal thermocline at its lower boundary develops during the summer season (Sur & Ilyin, 1997). The deepening of the UML has an important effect on the supply of nutrients into the euphotic upper layer from the underlying nutrient-rich water mass. The temperature of the UML at any given location is dependent on the surface heat flux, horizontal advection of heat, the depth and the rate of deepening of the UML. In this study we use a 3D ocean circulation model, NEMO-SHELF (O'Dea et al, 2012) to simulate the parameters of the UML in the Black Sea over the last 34 years. The model has horizontal resolution of 1/12×1/16 degrees and 33 layers in the vertical. The vertical discretization uses a hybrid enveloped s-z grid developed in Shapiro et al. (2012). The model is spun up from climatology (Suvorov et al., 2004); it is forced by the Drakkar Forcing Set v5.2 (Brodeau et al., 2010, Meinvielle et al., 2013) and river discharges from 8 major rivers are included. For each year the model is run from 1st January and the data for the period April to October are used for analysis. The sea surface temperature produced by the model is compared with satellite data ( Modis-Aqua, 2013) to show a good agreement. The model simulations are validated against in-situ observations (BSERP-3, 2004; Piotukh et al., 2011). The analysis is performed for the deep basin where the depth of the sea is greater than 1000m. It clearly shows the inter-annual variations of both the SST and the depth of UML. The depth of UML is

  15. Annual migratory patterns of long-billed curlews in the American west

    USGS Publications Warehouse

    Page, Gary W.; Warnock, Nils; Tibbitts, T. Lee; Jorgensen, Dennis; Hartman, C. Alex; Stenzel, Lynne E.

    2014-01-01

    Effective conservation of migratory species requires comprehensive knowledge of annual movement patterns. Such information is sparse for the Long-billed Curlew (Numenius americanus), a North American endemic shorebird of conservation concern. To test hypotheses about individual and area differences in migratory patterns across western North America, we tagged 29 curlews with satellite transmitters at breeding sites in Oregon, Nevada, and Montana. Transmissions from 28 birds for up to 4 years demonstrated that all wintered within the species’ known winter range, including 9 from Oregon tracked to agricultural areas of California’s Central Valley; 5 from Nevada tracked to the Central Valley, northern Gulf of California, or west coast of Baja California, Mexico; and 14 from Montana that wintered inland, from the Texas Panhandle south to the Mexican Plateau, or near the Gulf of Mexico. Montana breeders migrated east of the Rocky Mountains and traveled more than twice the distance of Oregon and Nevada breeders. Montana birds also stopped more often and longer during most passages. As a group, curlews arrived on their Oregon breeding grounds earlier than in Montana, while males preceded females in Montana and possibly Oregon. No consistent pattern emerged between sexes in departure from breeding areas, although within pairs males departed later than their mates. Individuals exhibited strong fidelity to breeding and wintering sites, and many birds showed a strong propensity for agricultural regions during winter. Our results underscore the importance of studying

  16. The inter-annual variability of the Yellow Sea Warm Current surface axis and its influencing factors

    NASA Astrophysics Data System (ADS)

    Song, Dehai; Bao, Xianwen; Wang, Xiaohua; Xu, Lingling; Lin, Xiaopei; Wu, Dexing

    2009-09-01

    Based on the Pathfinder sea surface temperature (PFSST), the surface axis and its pattern of the Yellow Sea Warm Current (YSWC) are discussed. A structure of double-warm-tongue is found in February and it varies in different years. Two indexes are calculated to represent the westward shift (WSI) and northward extension (NEI) of the warm water in the Yellow Sea (YS). Wavelet analysis illustrates that the WSI and NEI have prominent periods of 3-6 years and 3-4 years, respectively. The Empirical Orthogonal Function (EOF) decomposition is applied to the winter wind stress curl and the Kuroshio Current (KC) transport, which are believed to play important roles in forcing the variability of the YSWC surface axis. Statistics shows that the WSI is significantly related with the second EOF mode of the wind stress curl in February, which may force the YSWC surface axis moving westward and maintaining the double warm tongues because of its opposite curl in the YSWC domain. The first EOF mode of wind stress curl in January is propitious for inducing the warm tongue in the YS to advance more northward. Hence, the wind stress curls both in January and in February could force variations of the YSWC surface axis; however, the effect of the January wind stress curl is relatively weaker than that of the February. The relationship between the NEI and the KC transport is remarkable, and it seems that the stronger KC supplies more power to push the YSWC northward against the southward wind.

  17. Inter-annual and Long-term Temperature Variations in the Mesopause Region at High Latitudes Generated by the Stratospheric QBO

    NASA Technical Reports Server (NTRS)

    Mayr, Hans G.; Mengel, John G.; Huang, Frank T.

    2007-01-01

    The Numerical Spectral Model (NSM) simulates the Quasi-biennial Oscillation (QBO) that dominates the zonal circulation of the lower stratosphere at low latitudes. In the model, the QBO is generated with parameterized small-scale gravity waves (GW), which are partially augmented in 3D with planetary waves owing to baroclinic instability. Due to GW filtering, the QBO extends into the upper mesosphere, evident in UARS zonal wind and TIMED temperature measurements. While the QBO zonal winds are confined to equatorial latitudes, even in simulations with latitude-independent wave source, the associated temperature variations extend to high latitudes. The meridional circulation redistributes some of the QBO energy to focus it partially onto the Polar Regions. The resulting QBO temperature variations away from the equator tend to increase at higher altitudes to produce inter-annual variations that can exceed 5 K in the polar mesopause region -- and our 3D model simulations show that the effect is variable from year to year and can produce large differences between the two hemispheres, presumably due to interactions involving the seasonal variations. Modeling studies with the NSM have shown that long-term variations can also be generated by the QBO interacting with the seasonal cycles through OW node-filtering. A 30-month QBO, optimally synchronized by the 6-month Semi-Annual Oscillation (SAO), thus produces a 5-year or semi-decadal (SD) oscillation -- and observational evidence for that has been provided by a recent analysis of stratospheric NCEP data. In a simulation with the 2D version of the NSM, this SD oscillation extends into the upper mesosphere, and we present results to show that the related temperature variations could contribute significantly to the long-term variations of the polar mesopause region. Quasi-decadal variations could furthermore arise from the modeled solar cycle modulations of the QBO and 12-month annual oscillation. Our numerical results are

  18. Inter-annual dynamics of the Barents Sea red king crab (Paralithodes camtschaticus) stock indices in relation to environmental factors

    NASA Astrophysics Data System (ADS)

    Dvoretsky, Alexander G.; Dvoretsky, Vladimir G.

    2016-12-01

    Knowledge of relationships between environmental variables and biological processes can greatly improve fisheries assessment and management in commercially important species. We analyzed the effects of environmental factors (climatic indices and water temperature) on the stock characteristics (total population number, number of pre-recruits and number of legal males) of the red king crab (Paralithodes camtschaticus), an introduced species in the Barents Sea. Stock trends in red king crab appear to be related to decadal climate shifts. Abundances were negatively related to the North Atlantic Oscillation index (NAO) in August and positively related to water temperature in late winter-early summer. Total and commercial stock abundance were negatively correlated with the lag-1 Arctic Oscillation index (AO) in August and the lag-2 winter NAO index. The total number of P. camtschaticus was most strongly associated with water temperature in spring and summer and NAO/AO indices in April and May. Lagged NAO indices in February and August (9 or 10 yr) had a positive relationship to the commercial stock of P. camtschaticus. These findings suggest that temperature conditions of current and previous year affect natural mortality of larvae and juvenile red king crabs. Warmer temperature conditions lead to increased biomass of red king crab food items. Negative correlations between climatic indices and the red king crab stocks may be associated with predator pressure on juvenile red king crabs or higher mortality because of predator or parasite pressure and diseases. The associations between stock indices and environmental variables could help better predict recruitment patterns of P. camtschaticus.

  19. Inter-annual variability of urolithiasis epidemic from semi-arid part of Deccan Volcanic Province, India: climatic and hydrogeochemical perspectives.

    PubMed

    Kale, Sanjay S; Ghole, Vikram Shantaram; Pawar, N J; Jagtap, Deepak V

    2014-01-01

    Semi-arid Karha basin from Deccan Volcanic Province, India was investigated for inter-annual variability of urolithiasis epidemic. The number of reported urolith patient, weather station data and groundwater quality results was used to assess impact of geoenvironment on urolithiasis. Data of 7081 urolith patient were processed for epidemiological study. Gender class, age group, year-wise cases and urolith type were studied in epidemiology. Rainfall, temperature, pan evaporation and sunshine hours were used to correlate urolithiasis. Further, average values of groundwater parameters were correlated with the number of urolith episodes. A total of 52 urolith samples were collected from hospitals and analysed using FTIR technique to identify dominant urolith type in study area. Result shows that male population is more prone, age group of 20-40 is more susceptible and calcium oxalate uroliths are dominant in study area. Year-wise distribution revealed that there is steady increase in urolithiasis with inflation in drought years. In climatic parameters, hot days are significantly correlated with urolithiasis. In groundwater quality, EC, Na and F are convincingly correlated with urolith patients, which concludes the strong relation between geo-environment and urolithiasis.

  20. Climate response and spatial-temporal model on the inter-annual change of winter temperature-salinity in the East China Sea

    NASA Astrophysics Data System (ADS)

    Yang, Jin-kun; Miao, Qing-sheng; Yang, Yang; Xu, Shan-shan

    2017-01-01

    Spatial distributions and time variation characteristics were analyzed using Rotated Empirical Orthogonal Function (REOF) and spectrum analysis methods using surface and bottom temperature and salinity data in February of 1976-2013 along 30°N section in the East China Sea. Result showed that temperature trends can be divided into western part and east part, salinity trend divided into western, middle and eastern part. The first mode of surface temperature presented a quasi-equilibrium trend and the range was higher in the near-shore than the offshores, first mode of bottom temperature presented a decreasing trend; surface salinity had a decreasing trend and the extent was higher in the near-shore than the offshores, the bottom salinity showed a decreasing trend in recent years. The temperature inter-annual variability related to El Niño closely; short-term shocks of salinity related to El Niño, and long-term changes had something to do with PDO.

  1. Inter-Annual Variability of Currents, Temperature and Salinity during 1998-2012 in a High-Resolution Ocean Model of the Western Indian Ocean

    NASA Astrophysics Data System (ADS)

    Jensen, T. G.; Ko, D. S.; Wijesekera, H. W.

    2014-12-01

    A simulation of the 3-dimensional ocean temperature, salinity and currents of from 1998 through 2012 was done using the Navy Coastal Ocean Model (NCOM) with a 6-km resolution and 40 vertical sigma-z levels. The forcing is 3-hourly atmospheric output from the Navy's Operational Global Prediction System (NOGAPS). The boundary conditions are provided by the 1/8o Global NCOM model. In addition, 8 semi-diurnal and diurnal tidal components and monthly climatological discharges of 37 rivers are included. The model assimilates satellite altimeter data, AVHRR SST and synthetic temperature and salinity profiles from the Modular Ocean Data Assimilation System (MODAS). The model output is filtered to remove tides and saved as daily averages. From out analysis we find large inter-annual variability in the strength of the South Equatorial Counter Current and in the subsurface temperature cold anomaly associated with Seyshelles-Chagos thermocline ridge. The cold anomaly was significantly reduced in 2007 during which had a rare co-occurrence of La Nina and positive Indian Ocean Dipole conditions. Year to year variability in the equatorial currents affects the Somali Current and the time of development and strength of the Great Whirl during the southwest monsoon.

  2. Intra- and Inter-Individual Variation in Self-Reported Code-Switching Patterns of Adult Multilinguals

    ERIC Educational Resources Information Center

    Dewaele, Jean-Marc; Li, Wei

    2014-01-01

    The present study is a large-scale quantitative analysis of intra-individual variation (linked to type of interlocutor) and inter-individual variation (linked to multilingualism, sociobiographical variables and three personality traits) in self-reported frequency of code-switching (CS) among 2116 multilinguals. We found a significant effect of…

  3. Understanding Historical Human Migration Patterns and Interbreeding (JGI Seventh Annual User Meeting 2012: Genomics of Energy and Environment)

    ScienceCinema

    Willerslev, Eske [University of Copenhagen

    2016-07-12

    Eske Willerslev from the University of Copenhagen on "Understanding Historical Human Migration Patterns and Interbreeding Using the Ancient Genomes of a Palaeo-Eskimo and an Aboriginal Australian" at the 7th Annual Genomics of Energy & Environment Meeting on March 21, 2012 in Walnut Creek, California.

  4. Universal Inverse Power-Law Distribution for Fractal Fluctuations in Dynamical Systems: Applications for Predictability of Inter-Annual Variability of Indian and USA Region Rainfall

    NASA Astrophysics Data System (ADS)

    Selvam, A. M.

    2017-01-01

    Dynamical systems in nature exhibit self-similar fractal space-time fluctuations on all scales indicating long-range correlations and, therefore, the statistical normal distribution with implicit assumption of independence, fixed mean and standard deviation cannot be used for description and quantification of fractal data sets. The author has developed a general systems theory based on classical statistical physics for fractal fluctuations which predicts the following. (1) The fractal fluctuations signify an underlying eddy continuum, the larger eddies being the integrated mean of enclosed smaller-scale fluctuations. (2) The probability distribution of eddy amplitudes and the variance (square of eddy amplitude) spectrum of fractal fluctuations follow the universal Boltzmann inverse power law expressed as a function of the golden mean. (3) Fractal fluctuations are signatures of quantum-like chaos since the additive amplitudes of eddies when squared represent probability densities analogous to the sub-atomic dynamics of quantum systems such as the photon or electron. (4) The model predicted distribution is very close to statistical normal distribution for moderate events within two standard deviations from the mean but exhibits a fat long tail that are associated with hazardous extreme events. Continuous periodogram power spectral analyses of available GHCN annual total rainfall time series for the period 1900-2008 for Indian and USA stations show that the power spectra and the corresponding probability distributions follow model predicted universal inverse power law form signifying an eddy continuum structure underlying the observed inter-annual variability of rainfall. On a global scale, man-made greenhouse gas related atmospheric warming would result in intensification of natural climate variability, seen immediately in high frequency fluctuations such as QBO and ENSO and even shorter timescales. Model concepts and results of analyses are discussed with reference

  5. Modeling effects of inter-annual variability in meteorological and land use conditions on coupled water and energy cycling in the cultivated African Sahel

    NASA Astrophysics Data System (ADS)

    Velluet, C.; Demarty, J.; Cappelaere, B.; Braud, I.; Boulain, N.; Favreau, G.; Charvet, G.; Ramier, D.; Issoufou, H.; Boucher, M.; Mainassara, I.; Chazarin, J.; Oï, M.; Yahou, H.; Benarrosh, N.; Ibrahim, M.

    2012-12-01

    In the dry tropics in general and in the African Sahel in particular, hydro-ecosystems are very sensitive to climate variability and land management. In the Niamey region of South-West Niger, a severe multi-decadal drought together with large-scale vegetation clearing coincided with an unexpected increase in surface and ground water resources. Such an apparent paradoxical situation illustrates the complex way in which climate and land cover interactions control the Sahelian water cycle dynamics. This stresses the importance of understanding and reliably modeling water/energy transfers in the local soil-plant-atmosphere system, under contrasted meteorological and surface conditions. This study investigates the effects of the inter-annual variability of meteorological and land use conditions on the coupled water and energy cycles in the cultivated Sahel over a 5-year period. This is based on a comprehensive multi-year field dataset acquired for a millet crop field and a fallow savannah, the two main land cover types of South-West Niger (Wankama catchment in the mesoscale AMMA-CATCH Niger observatory, part of the French-initiated RBV network). It includes atmospheric forcing, seasonal course of vegetation phenology, soil properties and model validation variables (net radiation, turbulent fluxes, soil heat/water profiles), for the two fields. The study area is typical of Central Sahel conditions, with 400-600 mm annual rainfall concentrated in the 4-5 month wet season. Soils are mainly sandy and prone to surface crusting, leading to a strong vertical contrast in hydrodynamic properties. The SiSPAT process-based model used solves the 1D mass and heat transfer system of equations in the soil, including vapor phase and coupled with a two-component (bare soil and vegetation) water and energy budget at the surface-atmosphere interface. The study explores whether such a model can be accurately calibrated and validated for the two sites using realistic-parameter values. The

  6. Atmospheric mercury measurements at a suburban site in the Mid-Atlantic United States: Inter-annual, seasonal and diurnal variations and source-receptor relationships

    NASA Astrophysics Data System (ADS)

    Ren, Xinrong; Luke, Winston T.; Kelley, Paul; Cohen, Mark D.; Artz, Richard; Olson, Mark L.; Schmeltz, David; Puchalski, Melissa; Goldberg, Daniel L.; Ring, Allison; Mazzuca, Gina M.; Cummings, Kristin A.; Wojdan, Lisa; Preaux, Sandra; Stehr, Jeff W.

    2016-12-01

    Different atmospheric mercury forms have been measured at a suburban site in Beltsville, Maryland in the Mid-Atlantic United States since 2007 to investigate their inter-annual, seasonal and diurnal variabilities. Average concentrations and standard deviations of hourly measurements from 2007 to 2015 were 1.41 ± 0.23 ng m-3 for gaseous elemental mercury (GEM), 4.6 ± 33.7 pg m-3 for gaseous oxidized mercury (GOM), and 8.6 ± 56.8 pg m-3 for particulate-bound mercury (PBM). Observations show that on average, the rates of decrease were 0.020 ± 0.007 ng m-3 yr-1 (or 1.3 ± 0.5% yr-1, statistically significant, p-value < 0.01) for GEM, 0.54 ± 0.19 pg m-3 yr-1 (or 7.3 ± 2.6% yr-1, statistically significant, p-value < 0.01) for GOM, and 0.15 ± 0.35 pg m-3 yr-1 (or 1.6 ± 3.8% yr-1, statistically insignificant, p-value > 0.01) for PBM over this nine-year period. In addition, the collocated annual mercury wet deposition decreased at a rate of 0.51 ± 0.24 μg m-2 yr-2 (or 4.2 ± 1.9% yr-1, statistically insignificant, p-value > 0.01). Diurnal variation of GEM shows a slight peak in the morning, likely due to the shallow boundary layer. Seasonal variation of GEM shows lower levels in fall. Both diurnal variations of GOM and PBM show peaks in the afternoon likely due to the photochemical production of reactive mercury from the oxidation of GEM and the influence of boundary layer processes. Seasonally, GOM measurements show high levels in spring and constant low levels in the other three seasons, while PBM measurements exhibit higher levels from late fall to early spring and lower levels from late spring to fall. These measurement data were analyzed using the HYSPLIT back trajectory model in order to examine possible source-receptor relationships at this suburban site. Trajectory frequency analysis shows that high GEM/GOM/PBM events were generally associated with high frequencies of the trajectories passing through areas with high mercury emissions, while low GEM

  7. Inter-annual trend of the primary contribution of ship emissions to PM2.5 concentrations in Venice (Italy): Efficiency of emissions mitigation strategies

    NASA Astrophysics Data System (ADS)

    Contini, Daniele; Gambaro, Andrea; Donateo, Antonio; Cescon, Paolo; Cesari, Daniela; Merico, Eva; Belosi, Franco; Citron, Marta

    2015-02-01

    Ships and harbour emissions are currently increasing, due to the increase of tourism and trade, with potential impact on global air pollution and climate. At local scale, in-port ship emissions influence air quality in coastal areas impacting on health of coastal communities. International legislations to reduce ship emissions, both at Worldwide and European levels, are mainly based on the use of low-sulphur content fuel. In this work an analysis of the inter-annual trends of primary contribution, ε, of tourist shipping to the atmospheric PM2.5 concentrations in the urban area of Venice has been performed. Measurements have been taken in the summer periods of 2007, 2009 and 2012. Results show a decrease of ε from 7% (±1%) in 2007 to 5% (±1%) in 2009 and to 3.5% (±1%) in 2012. The meteorological and micrometeorological conditions of the campaigns were similar. Tourist ship traffic during measurement campaigns increased, in terms of gross tonnage, of about 25.4% from 2007 to 2009 and of 17.6% from 2009 to 2012. The decrease of ε was associated to the effect of a voluntary agreement (Venice Blue Flag) for the use of low-sulphur content fuel enforced in the area between 2007 and 2009 and to the implementation of the 2005/33/CE Directive in 2010. Results show that the use of low-sulphur fuel could effectively reduce the impact of shipping to atmospheric primary particles at local scale. Further, voluntary agreement could also be effective in reducing the impact of shipping on local air quality in coastal areas.

  8. Integrating inter- and intra-annual tree-ring width, carbon isotopes and anatomy: responses to climate variability in a temperate oak forest

    NASA Astrophysics Data System (ADS)

    Granda, Elena; Bazot, Stéphane; Fresneau, Chantal; Boura, Anaïs; Faccioni, Georgia; Damesin, Claire

    2015-04-01

    While many forests are experiencing strong tree declines due to climate change in temperate ecosystems, others nearby to those declining show no apparent signs of decline. This could be due to particular microsite conditions or, for instance, to a higher plasticity of given traits that allow a better performance under stressful conditions. We studied oak functional mechanisms (Quercus petraea) leading to the apparently healthy status of the forest and their relation to the observed climatic variability. This study was conducted in the Barbeau Forest (northern France), where cores from mature trees were collected. Three types of functional traits (secondary growth, physiological variables - δ13C and derived Δ13C and iWUE- and several anatomical ones -e.g. vessel area, density-) were recorded for each ring for the 1991-2011 period, distinguishing EW from LW in all measured traits. Among the three types of functional traits, those related to growth experienced the highest variability both between years and between individuals, followed by anatomical and physiological ones. Secondary growth maintained a constant trend during the study period. Instead, ring, EW and LW δ13C slightly declined from 1991 to 2011. Additional intra-ring δ13C analyses allowed for a more detailed understanding of the seasonal dynamics within each year. In particular, the year 2007 (an especially favorable climatic year during the growing season) showed the lowest δ13C values during the EW-LW transition for the whole study period. Inter-annual anatomical traits varied in their responses, but in general, no temporal trends were found. The results from structural equation modeling (SEM) showed direct relationships of seasonal climate and growth, as well as indirect relationships mediated by anatomical and physiological traits. We further discuss the implications of these results on future forest responses to ongoing climate changes.

  9. Seasonal and Inter-annual Changes in Photosynthetic and Soil Respiratory Processes in a Cool-temperate Deciduous Forest on a Mountainous Landscape in Japan.

    NASA Astrophysics Data System (ADS)

    Muraoka, H.; Noh, N. J.; Saitoh, T. M.; Nagao, A.; Noda, H. M.; Kuribayashi, M.; Nagai, S.

    2015-12-01

    Carbon budget of terrestrial ecosystems is one of the most crucial themes in ecosystem sciences under current and future climate changes as it would affect our Earth system. Remote sensing and modeling analysis studies from continental to global scales have been indicating that the recent climate change is influential to photosynthetic processes in terrestrial vegetation such as forests and grasslands, by altering phenology (seasonal change) and foliage biomass. In addition, increasing temperature and possibly changing photosynthetic activities of plants are influential to soil carbon dynamics. Our deeper and broader understandings on such photosynthetic and respiratory processes governing carbon cycle and hence budget of terrestrial ecosystems are critical to detect the changes of ecosystem processes and the functions in changing environments, as they would influence the biodiversity, ecosystem services and Earth system.In order to reveal the nature of temporal changes in photosynthetic and respiratory processes in forest ecosystems, we have been conducting multi-disciplinary observations of ecophysiological and optical properties for canopy photosynthesis in a cool-temperate deciduous forest since 2003 ("Takayama site", contributing to AsiaFlux and JaLTER). In addition, open-field warming experiments have been conducted since 2011 to examine the possible influence of near-future warming condition on forest canopy photosynthesis and soil respiration. (1) Our long-term measurements of leaf and canopy photosynthesis revealed that their phenology is influenced by inter-annual variation of micrometeorological conditions. (2) Combined analysis of leaf-canopy photosynthesis and optical properties enabled us to estimate the forest photosynthetic productivity at regional scale by satellite data. (3) Open-field warming experiments suggested that tree foliage and soil processes would acclimate to near-future warming conditions.

  10. Analysis of the seasonal and inter-annual variations, and long-term trends of ozone in the metropolitan area of Monterrey, Mexico

    NASA Astrophysics Data System (ADS)

    Yassmany Hernández Paniagua, Iván; Clemitshaw, Kevin C.; Mendoza, Alberto

    2016-04-01

    Since 1993, high-precision and high-frequency measurements of ambient O3 have been recorded at 5 sites within the metropolitan area of Monterrey, the third largest city in Mexico. O3was measured by the Integral Environmental Monitoring System of the Nuevo Leon State Government using commercially available, conventional UV photometry instrumentation (precision better than ±1 ppb). The datasets exhibit variations on differing time-scales of minutes to hours, with evidence of seasonal cycles and inter-annual variability. The O3 diurnal cycles vary with length of daylight, which influences its formation and loss via photochemistry. No apparent influence is observed in the amplitudes of O3 diurnal cycles recorded during weekdays with higher emissions from fossil fuel combustion than at weekends, although larger amplitudes occur at sites with polluted air from industrial areas. Seasonal cycles are driven by the variation in solar radiation and changes in emissions of primary precursors, VOCs and NOX. Maximum O3 mixing ratios were recorded in spring, and minimum values in winter, with a secondary trough during summer due to the advection of clean air masses from the Gulf of Mexico. The largest spring maxima are recorded downwind of an industrial area likely due photochemical processing of VOCs and NOx, with the lowest recorded in a highly populated area due to reaction of O3 and NO. At all sites, decreasing seasonal amplitudes were observed during 1993-1998, followed by persistent increases from 1998 to 2014. Wind sector analyses were carried out by splitting the wind direction into 8 categories (45°). At all sites, the highest O3 mixing ratios were recorded from the E and SE sectors, with lowest values recorded in air masses from the W and NW. Wind sector analysis of primary precursors (such as VOCs, CO, NOX) reveal that sources are dominated by emissions from industrial regions in Monterrey and surrounding areas. The largest annual growth rates for the E and SE

  11. Regional and inter-annual variability in Atlantic zooplankton en route to the Arctic Ocean: potential effects of multi-path Atlantic water advection through Fram Strait and the Barents Sea

    NASA Astrophysics Data System (ADS)

    Kwasniewski, Slawomir; Gluchowska, Marta; Trudnowska, Emilia; Ormanczyk, Mateusz; Walczowski, Waldemar; Beszczynska-Moeller, Agnieszka

    2016-04-01

    The Arctic is among the regions where the climate change effects on ecosystem will be the most rapid and consequential, with Arctic amplification recognized as an integral part of the process. Great part of the changes are forced by advection of warm waters from the North Atlantic and the expected modifications of Arctic marine ecosystem will be induced not only by changing environmental conditions but also as a result of introducing Atlantic biota. Thus, the knowledge of physical and biological heterogeneity of Atlantic inflow is requisite for understanding the effects of climate change on biological diversity and ecosystem functioning in the Arctic. The complex and variable two-branched structure of the Atlantic Water flow via Fram Strait and the Barents Sea most likely has a strong influence on the ocean biology in these regions, especially in the pelagic realm. Zooplankton are key components of marine ecosystems which form essential links between primary producers and grazer/predator consumers, thus they are important for functioning of the biological carbon pump. Changes in zooplankton distribution and abundance may have cascading effects on ecosystem functioning, with regulatory effects on climate. Based on data collected in summers of 2012-2014, within the scope of the Polish-Norwegian PAVE research project, we investigate zooplankton distribution, abundance and selected structural characteristics of communities, in relation to water mass properties in the Atlantic Water complex flow to the Arctic Ocean. The main questions addressed here are: what are the differences in zooplankton patterns between the Fram Strait and Barents Sea branches, and how does the inter-annual variability of Atlantic Water advection relate to changes in zooplankton? The results of the investigation are precondition for foreseeing changes in the pelagic realm in the Arctic Ocean and are necessary for constructing and tuning plankton components of ecosystem models.

  12. Geospatial and temporal patterns of annual cholera outbreaks in Matlab, Bangladesh

    NASA Astrophysics Data System (ADS)

    Majumder, M. S.; de Klerk, K.; Meyers, D.

    2012-12-01

    Cholera is a waterborne diarrheal disease endemic to Bangladesh, resulting in 1 million diagnoses annually. Such disease burden results in incalculable lost wages and treatment expenses, taken from the pockets of an already impoverished society. Two seasonally correlated outbreaks of cholera occur in Bangladesh every year. In the spring and early summer, the Bay of Bengal - which serves as a natural reservoir for the cholera bacteria - flows inland, causing the first outbreak amongst coastal communities. Waste containing the cholera bacteria enters the sewage system and remains untreated due to poor water and sanitation infrastructure. Therefore, during the following monsoon season, flooding of cholera-contaminated sewage into drinking water sources results in a second outbreak. Though considered common knowledge among local populations, this geographic and temporal progression has not been empirically verified in the current literature. The aim of our ongoing study is to systematically analyze the seasonal trajectory of endemic cholera in Bangladesh. This paper discusses the results obtained from a comprehensive survey of available cholera data from the International Centre of Diarrheal Disease Research, Bangladesh (ICDDR,B) in Matlab, Bangladesh. Matlab thana is a near-coastal community that consists of 142 villages. Monsoon season takes place from June through October. Due to its proximity to the Meghna River, which opens into the Bay of Bengal, the area experiences significant flooding during these months. Using 10 years of geographically referenced cholera data, cases were plotted in time and space. Preliminary patterns suggest that villages closer to the Meghna River experience the majority of the area's cholera outbreaks and that case count is highest in late spring and late fall. April/May and November/December represent 25% and 23% of total annual case counts respectively. Moreover, villages further from the coastline demonstrate 57% higher relative

  13. How tropical cyclone inter-annual timing and trajectory control gross primary productivity in the SE US at seasonal and annual timescales and impacts on mountain forest eco-hydrology

    NASA Astrophysics Data System (ADS)

    Lowman, L.; Barros, A.

    2015-12-01

    Tropical cyclones (TCs) are an important source of freshwater input to the SE US eco-hydrologic function. Soil moisture, a temporal integral of precipitation, is critical to plant photosynthesis and carbon assimilation. In this study, we investigate the impact TCs have on gross primary productivity (GPP) in the SE US using the physically-based Duke Coupled Hydrology Model with Vegetation (DCHM-V) which includes coupled water and energy cycles and a biochemical representation of photosynthesis. A parsimonious evaluation of model-estimated GPP against all available AmeriFlux data in the SE US is presented. We characterize the seasonality of vegetation activity in the SE US by simulating water, energy, and carbon fluxes using the DCHM-V at high spatial (4 km) and temporal (30-min) resolution over the period 2002 - 2012. The model is run offline using atmospheric forcing data from NLDAS-2, precipitation from StageIV, and phenology indices from MODIS FPAR/LAI. Analysis of model results show the tendency for low GPP to occur in the Appalachian Mountains during peak summer months when water stress limits stomatal function. We contrast these simulations with model runs where periods of TC activity are replaced with the monthly climatological diurnal cycle from NARR. Results show that the timing and trajectory of TCs are key to understanding their impact on GPP across the SE US. Specifically: 1) Timing of moisture input from TCs greatly influences the vegetation response. TCs during peak summer months increase GPP and years with TCs falling in peak summer months see much higher annual GPP averages; 2) Years of drought and low plant productivity (2006-2007, 2011-2012) in the SE US tend to have TCs that fall later in the year when the additional moisture input does not have a significant impact on vegetation activity; and 3) TC path impacts regional GPP averages. The mountain region shows large inter- and intra-annual variability in plant productivity and high sensitivity to

  14. Inter-annual variability of surface ozone at coastal (Dumont d'Urville, 2004-2014) and inland (Concordia, 2007-2014) sites in East Antarctica

    NASA Astrophysics Data System (ADS)

    Legrand, Michel; Preunkert, Susanne; Savarino, Joël; Frey, Markus M.; Kukui, Alexandre; Helmig, Detlev; Jourdain, Bruno; Jones, Anna E.; Weller, Rolf; Brough, Neil; Gallée, Hubert

    2016-07-01

    Surface ozone has been measured since 2004 at the coastal East Antarctic site of Dumont d'Urville (DDU), and since 2007 at the Concordia station located on the high East Antarctic plateau. This paper discusses long-term changes, seasonal and diurnal cycles, as well as inter-annual summer variability observed at these two East Antarctic sites. At Concordia, near-surface ozone data were complemented by balloon soundings and compared to similar measurements done at the South Pole. The DDU record is compared to those obtained at the coastal site of Syowa, also located in East Antarctica, as well as the coastal sites of Neumayer and Halley, both located on the coast of the Weddell Sea in West Antarctica. Surface ozone mixing ratios exhibit very similar seasonal cycles at Concordia and the South Pole. However, in summer the diurnal cycle of ozone is different at the two sites with a drop of ozone in the afternoon at Concordia but not at the South Pole. The vertical distribution of ozone above the snow surface also differs. When present, the ozone-rich layer located near the ground is better mixed and deeper at Concordia (up to 400 m) than at the South Pole during sunlight hours. These differences are related to different solar radiation and wind regimes encountered at these two inland sites. DDU appears to be the coastal site where the impact of the late winter/spring bromine chemistry is the weakest, but where the impact of elevated ozone levels caused by NOx snow emissions from the high Antarctic plateau is the highest. The highest impact of the bromine chemistry is seen at Halley and Neumayer, and to a lesser extent at Syowa. These three sites are only weakly impacted by the NOx chemistry and the net ozone production occurring on the high Antarctic plateau. The differences in late winter/spring are attributed to the abundance of sea ice offshore from the sites, whereas those in summer are related to the topography of East Antarctica that promotes the katabatic flow

  15. Differential responses of seabirds to inter-annual environmental change in the continental shelf and oceanic habitats of southeastern Bering Sea

    NASA Astrophysics Data System (ADS)

    Yamamoto, T.; Kokubun, N.; Kikuchi, D. M.; Sato, N.; Takahashi, A.; Will, A.; Kitaysky, A. S.; Watanuki, Y.

    2015-11-01

    Seasonal sea-ice cover has been decreasing in the southeastern Bering Sea shelf, which might affect ecosystem dynamics and availability of food resources to marine top predators breeding in the region. In this study, we investigated the foraging responses of two seabird species, surface-foraging red-legged kittiwakes Rissa brevirostris (hereafter, RLKI) and pursuit-diving foraging thick-billed murres Uria lomvia (TBMU) to the inter-annual change in environmental conditions. Between the study years, winter ice retreated earlier and summer water temperatures were warmer in 2014 compared to those in 2013. At-sea distributions of RLKI and TBMU breeding on St. George Island, the largest seabird colony in the region, were recorded using GPS loggers, and blood samples were taken to examine their physiological condition and isotopic foraging niche in a given year. RLKI foraging occurred mostly over the oceanic basin in both years. TBMU, however, foraged mostly over the shelf, but showed a relatively higher use of the shelf break and oceanic basin in the colder year, 2013. The foraging distances from the colony peaked at 250-300 km in 2013 and, bimodally, at 150-250 and 300-350 km in 2014 for RLKI, and tended to be farther in 2013 compared to those in 2014 for TBMU. Plasma levels of corticosterone did not differ between years in RLKI, but differed in TBMU, showing higher levels of physiological stress incurred by murres during the colder year, 2013. δ13N (a proxy of trophic level of prey) did not differ between the years in either RLKI or TBMU, while δ13C (a proxy of prey origin) were lower in 2014 than in 2013 in both species, suggesting possible differences in influx of oceanic prey items into foraging areas. These results suggest that the response of ecosystem dynamics to climate variability in the southeast Bering Sea may differ between the ocean basin and continental shelf regions, which, in turn, may generate differential responses in seabirds relying on those

  16. Inter-annual Variability of Evapotranspiration in a Semi-arid Oak-savanna Ecosystem: Measured and Modeled Buffering to Precipitation Changes

    NASA Astrophysics Data System (ADS)

    Raz-Yaseef, N.; Sonnentag, O.; Kobayashi, H.; Baldocchi, D. D.

    2010-12-01

    Precipitation (P) is the primary control on vegetation dynamics and productivity, implying that climate induced disturbances in frequency and timing of P are intimately coupled with fluxes of carbon, water and energy. Future climate change is expected to increase extreme rainfall events as well as droughts, suggesting linked vegetation changes to an unknown extent. Semi-arid climates experience large inter-annual variability (IAV) in P, creating natural conditions adequate to study how year-to-year changes in P affect atmosphere-biosphere fluxes. We used a 10-year flux database collected at a semi-arid savanna site in order to: (1) define IAV in P by means of frequency and timing; (2) investigate how changes in P affect the ecohydrology of the forest and its partitioning into the main vapor fluxes, and (3) evaluate model capability to predict IAV of carbon and water fluxes above and below the canopy. This is based on the perception that the capability of process-oriented models to construct the deviation, and not the average, is important in order to correctly predict ecosystem sensitivity to climate change. Our research site was a low density and low LAI (0.8) semi-arid (P=523±180 mm yr-1) savanna site, combined of oaks and grass, and located at Tonzi ranch, California. Measurements of carbon and water fluxes above and below the tree canopy using eddy covariance and supplementary measurements have been made since 2001. Measured fluxes were compared to modeled based on two bio-meteorological process-oriented ecosystem models: BEPS and 3D-CAONAK. Our results show that IAV in P was large, and standard deviation (STD) was 38% of the average. Accordingly, the wet soil period (measured volumetric water content > 8%) varied between 156 days in dry years to 301 days in wet years. IAV of the vapor fluxes were lower than that of P (STD was 17% for the trees and 23% for the floor components), suggesting on ecosystem buffering to changes in P. The timing of grass green up

  17. Molecular phylogenetics of Micromeria (Lamiaceae) in the Canary Islands, diversification and inter-island colonization patterns inferred from nuclear genes.

    PubMed

    Puppo, Pamela; Curto, Manuel; Gusmão-Guedes, Joana; Cochofel, Jaqueline; Pérez de Paz, Pedro Luis; Bräuchler, Christian; Meimberg, Harald

    2015-08-01

    Here we reconstruct the evolutionary history of Micromeria in the Canary Islands using eight nuclear markers. Our results show two centers of diversification for Micromeria, one in the eastern islands Gran Canaria and Lanzarote, the other in the western islands, Tenerife, La Palma and El Hierro. Suggested directions of inter-island colonization are the following: Gran Canaria to Lanzarote and La Gomera; Tenerife to La Palma (from the paleoisland of Teno), to El Hierro (from the younger, central part), and to La Gomera and Madeira (from the paleoislands). Colonization of La Gomera probably occurred several times from Gran Canaria and Tenerife. The taxonomic implications of these results are discussed. Incongruence among the different markers was evaluated and, using next generation sequencing, we investigated if this incongruence is due to gene duplication.

  18. Academic Calendar Change Impact on Enrollment Patterns and Instructional Outcomes. AIR 1983 Annual Forum Paper.

    ERIC Educational Resources Information Center

    Coleman, Daniel; And Others

    The effects of a calendar change from the quarter system to the semester system on enrollment patterns, student credit hour productivity, grading patterns, and course completion patterns were investigated. Enrollment and grade pattern data were collected for nine Florida public universities and Iowa State University, for 1980-1982. Additionally, a…

  19. Inter-annual variability of air mass and acidified pollutants transboundary exchange in the north-eastern part of the EANET region

    NASA Astrophysics Data System (ADS)

    Gromov, Sergey A.; Trifonova-Yakovleva, Alisa; Gromov, Sergey S.

    2016-04-01

    ]. This dataset provides comprehensive monthly statistics on the wind meteorological regime at the stations of interest in a given range of altitudes. Based on long-term source observational data, the dataset is assumed being representative up to date, which allowed us to estimate monthly pollutant fluxes for the years 2006-2008 over segments of the Russian border and its whole [4]. In the current phase of our study, we calculate the inter-annual variations in the transboundary pollutant fluxes for 2000-2012 using longer-term EANET data and transient changes in air mass fluxes derived from the meteorological wind fields from ERA INTERIM re-analysis [5]. We gauge similar average air transport terms and dynamics from the statistical and reanalysis data, which bolsters our earlier findings. The reanalysis data, being naturally more variable, convolutes the variations in net air fluxes and pollutant concentrations into several episodes we emphasise, in addition to the integral pollutant transfer terms we estimate. At last, we discuss on the possibility of climate change effect on the flux strength and dynamics together with regional air quality tendencies in North-East Asia countries. References: Izrael, Yu.A., et al.: Monitoring of the Transboundary Air Pollution Transport. Gidrometeoizdat, Leningrad, 303 p., 187 (in Russian). Akimoto H., et al.: Periodic Report of the State of Acid Deposition in East Asia. Part I: Regional Assessment. EANET-UNEP/RRC.AP-ADORC, 258 p., 2006. Brukhan, F.F.: Aeroclimatic Characteristics of the Mean Winds over USSR (ed. Ignatjushina E.N.). Gidrometeoizdat, Moscow, 54 p., 1984 (in Russian). Gromov S.A., et al.: First-order evaluation of transboundary pollution fluxes in areas of EANET stations in Eastern Siberia and the Russian Far East. EANET Science Bulletin, vol. 3, pp. 195-203, 2013. Dee, D. P., et al.: The ERA-Interim reanalysis: configuration and performance of the data assimilation system, Quart. J. Royal Met. Soc., 137, 553-597, doi: 10

  20. Reconciling patterns of inter-ocean molecular variance from four classes of molecular markers in blue marlin (Makaira nigricans).

    PubMed

    Buonaccorsi, V P; McDowell, J R; Graves, J E

    2001-05-01

    Different classes of molecular markers occasionally yield discordant views of population structure within a species. Here, we examine the distribution of molecular variance from 14 polymorphic loci comprising four classes of molecular markers within approximately 400 blue marlin individuals (Makaira nigricans). Samples were collected from the Atlantic and Pacific Oceans over 5 years. Data from five hypervariable tetranucleotide microsatellite loci and restriction fragment length polymorphism (RFLP) analysis of whole molecule mitochondrial DNA (mtDNA) were reported and compared with previous analyses of allozyme and single-copy nuclear DNA (scnDNA) loci. Temporal variance in allele frequencies was nonsignificant in nearly all cases. Mitochondrial and microsatellite loci revealed striking phylogeographic partitioning among Atlantic and Pacific Ocean samples. A large cluster of alleles was present almost exclusively in Atlantic individuals at one microsatellite locus and for mtDNA, suggesting that, if gene flow occurs, it is likely to be unidirectional from Pacific to Atlantic oceans. Mitochondrial DNA inter-ocean divergence (FST) was almost four times greater than microsatellite or combined nuclear divergences including allozyme and scnDNA markers. Estimates of Neu varied by five orders of magnitude among marker classes. Using mathematical and computer simulation approaches, we show that substantially different distributions of FST are expected from marker classes that differ in mode of inheritance and rate of mutation, without influence of natural selection or sex-biased dispersal. Furthermore, divergent FST values can be reconciled by quantifying the balance between genetic drift, mutation and migration. These results illustrate the usefulness of a mitochondrial analysis of population history, and relative precision of nuclear estimates of gene flow based on a mean of several loci.

  1. Intra- and inter-group coordination patterns reveal collective behaviors of football players near the scoring zone.

    PubMed

    Duarte, Ricardo; Araújo, Duarte; Freire, Luís; Folgado, Hugo; Fernandes, Orlando; Davids, Keith

    2012-12-01

    This study examined emergent coordination processes in collective patterns of behavior in 3 vs 3 sub-phases of the team sport of association football near the scoring zone. We identified coordination tendencies for the centroid (i.e., team center) and surface area (i.e., occupied space) of each sub-group of performers (n=20 plays). We also compared these kinematic variables at three key moments of play using mixed-model ANOVAs. The centroids demonstrated a strong symmetric relation that described the coordinated attacking/defending actions of performers in this sub-phase of play. Conversely, analysis of the surface area of each team did not reveal a clear coordination pattern between sub-groups. But the difference in the occupied area between the attacking and defending sub-groups significantly increased over time. Findings emphasized that major changes in sub-group behaviors occurred just before an assisted pass was made (i.e., leading to a loss of stability in the 3 vs 3 sub-phases).

  2. Seasonal and Inter-Annual Variations in Carbon Dioxide Exchange over an Alpine Grassland in the Eastern Qinghai-Tibetan Plateau.

    PubMed

    Shang, Lunyu; Zhang, Yu; Lyu, Shihua; Wang, Shaoying

    2016-01-01

    This work analyzed carbon dioxide exchange and its controlling factors over an alpine grassland on the eastern Qinghai-Tibetan Plateau. The main results show that air temperature and photosynthetically active radiation are two dominant factors controlling daily gross primary production. Soil temperature and soil water content are the main factors controlling ecosystem respiration. Canopy photosynthetic activity is also responsible for the variation of daily ecosystem respiration other than environmental factors. No clear correlation between net ecosystem exchange and environmental factors was observed at daily scale. Temperature sensitive coefficient was observed to increase with larger soil water content. High values of temperature sensitive coefficient occurred during the periods when soil water content was high and grass was active. Annual integrated net ecosystem exchange, gross primary production and ecosystem respiration were -191, 1145 and 954 g C m-2 for 2010, and -250, 975 and 725 g C m-2 for 2011, respectively. Thus, this alpine grassland was a moderate carbon sink in both of the two years. Compared to alpine grasslands on the Qinghai-Tibetan Plateau, this alpine grassland demonstrated a much greater potential for carbon sequestration than others. Annual precipitation is a dominant factor controlling the variation of annual net ecosystem exchange over this grassland. The difference in gross primary production between the two years was not caused by the variation in annual precipitation. Instead, air temperature and the length of growing season had an important impact on annual gross primary production. Variation of annual ecosystem respiration was closely related to annual gross primary production and soil water content during the growing season.

  3. Seasonal and Inter-Annual Variations in Carbon Dioxide Exchange over an Alpine Grassland in the Eastern Qinghai-Tibetan Plateau

    PubMed Central

    Shang, Lunyu; Zhang, Yu; Lyu, Shihua; Wang, Shaoying

    2016-01-01

    This work analyzed carbon dioxide exchange and its controlling factors over an alpine grassland on the eastern Qinghai-Tibetan Plateau. The main results show that air temperature and photosynthetically active radiation are two dominant factors controlling daily gross primary production. Soil temperature and soil water content are the main factors controlling ecosystem respiration. Canopy photosynthetic activity is also responsible for the variation of daily ecosystem respiration other than environmental factors. No clear correlation between net ecosystem exchange and environmental factors was observed at daily scale. Temperature sensitive coefficient was observed to increase with larger soil water content. High values of temperature sensitive coefficient occurred during the periods when soil water content was high and grass was active. Annual integrated net ecosystem exchange, gross primary production and ecosystem respiration were -191, 1145 and 954 g C m-2 for 2010, and -250, 975 and 725 g C m-2 for 2011, respectively. Thus, this alpine grassland was a moderate carbon sink in both of the two years. Compared to alpine grasslands on the Qinghai-Tibetan Plateau, this alpine grassland demonstrated a much greater potential for carbon sequestration than others. Annual precipitation is a dominant factor controlling the variation of annual net ecosystem exchange over this grassland. The difference in gross primary production between the two years was not caused by the variation in annual precipitation. Instead, air temperature and the length of growing season had an important impact on annual gross primary production. Variation of annual ecosystem respiration was closely related to annual gross primary production and soil water content during the growing season. PMID:27861616

  4. ENSO- and PDO-modulated SST Reconstructions From the Anthropocene Into the Last 2 Millennia: Planktonic Foraminiferal Mg/Ca Evidence at Inter-annual Resolution From San Lázaro Basin (NE Pacific)

    NASA Astrophysics Data System (ADS)

    Mortyn, P.; Martinez-Boti, M. A.; Herguera, J. C.

    2008-12-01

    On inter-annual time scales, the El Niño / Southern Oscillation (ENSO) climatic phenomenon is the largest driver of change in the ocean-atmosphere system. As such, it is a primary interest to understand how modern global warming has impacted ENSO, and how the marine sedimentary archive records this linkage in the southern California Current (CC). This would allow detailed comparison against other high-resolution archives, such as corals, and an improved ability to interpret past events as potential analogs for the future of ENSO. Furthermore, such reconstructions in recent millennia are crucial, since they record pre- anthropogenic climates under interglacial (warm) boundary conditions that allow us to characterize the nature of modern influence on this system. Here we present sub-decadal reconstructions of sea surface temperature (SST), derived from the Mg/Ca ratio of the shallow-dwelling planktonic foraminifera Globigerinoides ruber. The samples come from San Lázaro Basin in the southern Baja California continental margin (25° N; 112° W), situated beneath the dynamic boundary of the cool eastern Pacific boundary CC of northern origin, and the warm subtropical water masses of southern origin. The bottom of this coastal basin (maximum depth of 540m) is bathed by oxygen-depleted waters that flow over a shallow sill at 370m. High levels of primary production and export of biogenic particles to depth ensue from strong seasonal upwelling processes during spring to early summer. This combination of high sediment production and preservation in an area very sensitive to ENSO impact allows for a high-resolution reconstruction of inter-annual climatic phenomena in this unique eastern boundary current setting. For our highest temporal detail, we examine 2 cores at interannual resolution for the past ~90 years, which we use to validate our proxy against instrumental SSTs. This variability is effectively traced by Mg/Ca in G. ruber, which has an affinity for warmer waters

  5. Proceedings of the Second Annual Symposium on Mathematical Pattern Recognition and Image Analysis Program

    NASA Technical Reports Server (NTRS)

    Guseman, L. F., Jr. (Principal Investigator)

    1984-01-01

    Several papers addressing image analysis and pattern recognition techniques for satellite imagery are presented. Texture classification, image rectification and registration, spatial parameter estimation, and surface fitting are discussed.

  6. Dosimetric consequences of inter-fraction breathing-pattern variation on radiotherapy with personalized motion-assessed margins.

    PubMed

    Kavanagh, A; McQuaid, D; Evans, P; Webb, S; Guckenberger, M

    2011-11-21

    The data from eight patients who had undergone stereotactic body radiotherapy were selected due to their 4D-CT planning scans showing that their tumours had respiratory induced motion trajectories of large amplitude (greater than 9 mm in cranio-caudal direction). Radiotherapy plans with personalized motion-assessed margins were generated for these eight patients. The margins were generated by inverse 4D planning on an eight-bin phase-sorted 4D-CT scan. The planning was done on an in-house software system with a non-rigid registration stage being completed using freely available software. The resultant plans were then recalculated on a 4D-CT scan taken later during the course of treatment. Simulated image-guided patient set-up was used to align the geometric centres of the tumour region and minimize any misalignment between the two reconstructions. In general, the variation in the patient breathing patterns was found to be very small. Consequently, the degradation of the mean dose to the tumour region was found to be around a few percent (<3%) and hence was not a large effect.

  7. Spatial Pattern and Scale Influence Invader Demographic Response to Simulated Precipitation Change in an Annual Grassland Community.

    PubMed

    Skaer Thomason, Meghan J; Rice, Kevin J

    2017-01-01

    It is important to predict which invasive species will benefit from future changes in climate, and thereby identify those invaders that need particular attention and prioritization of management efforts. Because establishment, persistence, and spread determine invasion success, this prediction requires detailed demographic information. Explicit study of the impact of pattern on demographic response is particularly important for species that are naturally patchy, such as the invasive grass, Aegilops triuncialis. In the northern California Coast Range, where climate change may increase or decrease mean annual rainfall, we conducted a field experiment to understand the interaction of climate change and local-scale patterning on the demography of A. triuncialis. We manipulated precipitation (reduced, ambient, or augmented), seed density, and seeding pattern. Demographic and environmental data were collected for three years following initial seeding. Pattern and scale figure prominently in the demographic response of A. triuncialis to precipitation manipulation. Pattern interacts with precipitation and seeding density in its influence on per-plant seed output. Although per-plot seed production was highest when seeds were not aggregated, per-plant seed output was higher in aggregated patches. Results suggest aggregation of invasive A. triuncialis reduces the detrimental impact of interspecific competition in its invaded community, and that interspecific competition per se has a stronger impact than intraspecific competition.

  8. Mean annual precipitation explains spatiotemporal patterns of Cenozoic mammal beta diversity and latitudinal diversity gradients in North America.

    PubMed

    Fraser, Danielle; Hassall, Christopher; Gorelick, Root; Rybczynski, Natalia

    2014-01-01

    Spatial diversity patterns are thought to be driven by climate-mediated processes. However, temporal patterns of community composition remain poorly studied. We provide two complementary analyses of North American mammal diversity, using (i) a paleontological dataset (2077 localities with 2493 taxon occurrences) spanning 21 discrete subdivisions of the Cenozoic based on North American Land Mammal Ages (36 Ma--present), and (ii) climate space model predictions for 744 extant mammals under eight scenarios of future climate change. Spatial variation in fossil mammal community structure (β diversity) is highest at intermediate values of continental mean annual precipitation (MAP) estimated from paleosols (∼ 450 mm/year) and declines under both wetter and drier conditions, reflecting diversity patterns of modern mammals. Latitudinal gradients in community change (latitudinal turnover gradients, aka LTGs) increase in strength through the Cenozoic, but also show a cyclical pattern that is significantly explained by MAP. In general, LTGs are weakest when continental MAP is highest, similar to modern tropical ecosystems in which latitudinal diversity gradients are weak or undetectable. Projections under modeled climate change show no substantial change in β diversity or LTG strength for North American mammals. Our results suggest that similar climate-mediated mechanisms might drive spatial and temporal patterns of community composition in both fossil and extant mammals. We also provide empirical evidence that the ecological processes on which climate space models are based are insufficient for accurately forecasting long-term mammalian response to anthropogenic climate change and inclusion of historical parameters may be essential.

  9. Spatial Pattern and Scale Influence Invader Demographic Response to Simulated Precipitation Change in an Annual Grassland Community

    PubMed Central

    2017-01-01

    It is important to predict which invasive species will benefit from future changes in climate, and thereby identify those invaders that need particular attention and prioritization of management efforts. Because establishment, persistence, and spread determine invasion success, this prediction requires detailed demographic information. Explicit study of the impact of pattern on demographic response is particularly important for species that are naturally patchy, such as the invasive grass, Aegilops triuncialis. In the northern California Coast Range, where climate change may increase or decrease mean annual rainfall, we conducted a field experiment to understand the interaction of climate change and local-scale patterning on the demography of A. triuncialis. We manipulated precipitation (reduced, ambient, or augmented), seed density, and seeding pattern. Demographic and environmental data were collected for three years following initial seeding. Pattern and scale figure prominently in the demographic response of A. triuncialis to precipitation manipulation. Pattern interacts with precipitation and seeding density in its influence on per-plant seed output. Although per-plot seed production was highest when seeds were not aggregated, per-plant seed output was higher in aggregated patches. Results suggest aggregation of invasive A. triuncialis reduces the detrimental impact of interspecific competition in its invaded community, and that interspecific competition per se has a stronger impact than intraspecific competition. PMID:28046090

  10. The dynamics of avian influenza in western Arctic snow geese: implications for annual and migratory infection patterns

    USGS Publications Warehouse

    Samuel, Michael D.; Hall, Jeffrey S.; Brown, Justin D.; Goldberg, Diana R.; Ip, Hon S.; Baranyuk, Vasily V.

    2015-01-01

    Wild water birds are the natural reservoir for low-pathogenic avian influenza viruses (AIV). However, our ability to investigate the epizootiology of AIV in these migratory populations is challenging, and despite intensive worldwide surveillance, remains poorly understood. We conducted a cross-sectional, retrospective analysis in Pacific Flyway lesser snow geese Chen caerulescens to investigate AIV serology and infection patterns. We collected nearly 3,000 sera samples from snow geese at 2 breeding colonies in Russia and Canada during 1993-1996 and swab samples from > 4,000 birds at wintering and migration areas in the United States during 2006-2011. We found seroprevalence and annual seroconversion varied considerably among years. Seroconversion and infection rates also differed between snow goose breeding colonies and wintering areas, suggesting that AIV exposure in this gregarious waterfowl species is likely occurring during several phases (migration, wintering and potentially breeding areas) of the annual cycle. We estimated AIV antibody persistence was longer (14 months) in female geese compared to males (6 months). This relatively long period of AIV antibody persistence suggests that subtype-specific serology may be an effective tool for detection of exposure to subtypes associated with highly-pathogenic AIV. Our study provides further evidence of high seroprevalence in Arctic goose populations, and estimates of annual AIV seroconversion and antibody persistence for North American waterfowl. We suggest future AIV studies include serology to help elucidate the epizootiological dynamics of AIV in wild bird populations.

  11. Annual patterns and budget of CO2 flux in an Alaskan arctic tussock tundra ecosystem at Atqasuk, Alaska

    NASA Astrophysics Data System (ADS)

    Oechel, W. C.; Kalhori, A. A.; Burba, G. G.; Gioli, B.

    2013-12-01

    Arctic ecosystem functioning is not only critically affected by climate change, but also has the potential for major positive feedbacks on climate. There is however relatively little information available on the role, patterns, and vulnerabilities of CO2 fluxes during the non-summer seasons. Presented here is a year-around study of CO2 fluxes in an Alaskan Arctic tussock tundra ecosystem. Also presented are key environmental controls on CO2 fluxes as well as possible impacts of likely changes in season timing. This is aided by a new empirical quantification of seasons in the Arctic based on net radiation, which can help describe seasonal responses to greenhouse gas fluxes under climate change. The fluxes were computed using standard FluxNet methodology and corrected using standard WPL density terms, adjusted for influences of instrument surface heating. The results showed that the non-summer season comprises a significant source of carbon to the atmosphere. The summer period was a net sink of 10.83 g C m-2 yr-1, while the non-summer seasons released more than four times the CO2 uptake observed in the summer, resulting in a net annual source of 37.6 g C m-2 yr-1 to the atmosphere. This shows a change in this region of the Arctic from a long-term annual sink of CO2 from the atmosphere to an annual source of CO2 from the terrestrial ecosystem and soils to the atmosphere. The results presented here demonstrate that nearly continuous observations may be required in order to accurately calculate the annual NEE of Arctic ecosystems, and to build predictive understanding that can be used to estimate, with confidence, Arctic fluxes under future conditions. Daily CO2 fluxes over the year, average daily net radiation, average daily PAR, average daily air temperature and average daily soil respiration (at -5 cm).

  12. Clinical venous thromboembolism following joint surgery: effect of extended thromboprophylaxis on its annual frequency and postoperative pattern over 22 years.

    PubMed

    Dahl, Ola E; Gudmundsen, Tor E; Pripp, Are H; Aanesen, Joakim J

    2014-03-01

    We describe annual incidences and 6-month postoperative patterns of clinical venous thromboembolism (VTE) in 9078 patients undergoing major joint surgery in a Scandinavian hospital. In cohort I (1989-1999), low-molecular-weight heparin thromboprophylaxis for 7 to 10 days was uniformly introduced, 5-week thromboprophylaxis becoming routine after total hip replacement (THR), partially applied after hip fracture surgery (HFS), but not used after total knee replacement (TKR) thereafter (2003-2011; cohort II). Mean annual VTE incidence was lower in cohort II than in cohort I after THR and HFS but not after TKR. In cohort I, the cumulative VTE incidence increased sharply during the first 5 postoperative weeks in all groups, subsequently plateauing up to 6 months postsurgery. In cohort II, this incidence remained low and stable during 5 weeks post-THR, rising gradually up to 6 months, with a comparable but less pronounced pattern following HFS but not TKR. In conclusion, the VTE risk after major joint surgery seems to persist after 5- and 1-week prophylaxis in patients undergoing hip surgery and TKR, respectively.

  13. Mouse white adipocytes and 3T3-L1 cells display an anomalous pattern of carnitine palmitoyltransferase (CPT) I isoform expression during differentiation. Inter-tissue and inter-species expression of CPT I and CPT II enzymes.

    PubMed Central

    Brown, N F; Hill, J K; Esser, V; Kirkland, J L; Corkey, B E; Foster, D W; McGarry, J D

    1997-01-01

    The outer mitochondrial membrane enzyme carnitine palmitoyltransferase I (CPT I) represents the initial and regulated step in the beta-oxidation of fatty acids. It exists in at least two isoforms, denoted L (liver) and M (muscle) types, with very different kinetic properties and sensitivities to malonyl-CoA. Here we have examined the relative expression of the CPT I isoforms in two different models of adipocyte differentiation and in a number of rat tissues. Adipocytes from mice, hamsters and humans were also evaluated. Primary monolayer cultures of undifferentiated rat preadipocytes expressed solely L-CPT I, but significant levels of M-CPT I emerged after only 3 days of differentiation in vitro; in the mature cell M-CPT I predominated. In sharp contrast, the murine 3T3-L1 preadipocyte expressed essentially exclusively L-CPT I, both in the undifferentiated state and throughout the differentiation process in vitro. This was also true of the mature mouse white fat cell. Fully developed adipocytes from the hamster and human behaved similarly to those of the rat. Thus the mouse white fat cell differs fundamentally from those of the other species examined in terms of tis choice of a key regulatory enzyme in fatty acid metabolism. In contrast, brown adipose tissue from all three rodents displayed the same isoform profiles, each expressing overwhelmingly M-CPT I. Northern blot analysis of other rat tissues established L-CPT I as the dominant isoform not only in liver but also in kidney, lung, ovary, spleen, brain, intestine and pancreatic islets. In addition to its primacy in skeletal muscle, heart and fat, M-CPT I was also found to dominate the testis. The same inter-tissue isoform pattern (with the exception of white fat) was found in the mouse. Taken together, the data bring to light an intriguing divergence between white adipocytes of the mouse and other mammalian species. They also raise a cautionary note that should be considered in the choice of animal model used

  14. Dealing with Variability: Inter and Intra-annual Climate Variability and its Impacts on Water Availability in the 19th Century Northeastern United States

    NASA Astrophysics Data System (ADS)

    Aloysius, N. R.; Witherell, B. B.; Allen, T. L.; Arrigo, J. S.; Vorosmarty, C. J.

    2009-12-01

    Freshwater plays a critical role in preserving the biological and hydrological functions of the terrestrial ecosystems that sustain civilization. Hydrologic processes shape the distribution, structure, and dynamics of biological systems, while the feedbacks from biological systems impact the hydrologic cycle. Climate is the main driver that adds dynamics to the hydrologic cycle. In order to identify the changes and variability in the Northeast region’s climate and to understand their impacts on the hydrological cycle, we are conducting an assessment of the region’s climate. Annual and monthly time series of precipitation and temperature data collected for one hundred locations in the region, spanning from Maine to Virginia, during the period 1800 to 1920 are analyzed to assess the spatial and temporal variations in climate. It has been reported that the region’s climate during the 19th century is largely modulated by climatic oceanicity and the sunspot rhythm, and, that human influence did not have significant impact on the regional climate. Our preliminary findings do not show significant variations in the mean annual climate, but show variations in intra-annual climate, particularly monthly precipitation. Based on the review of historical documents, the intra-annual variation in precipitation was a concern of water resource planners during the 19th century. The present research attempts to bring out linkages between spatial and temporal variations in the regional climate and water availability. Additional information on land cover, measured and modeled runoff for a selected location will be used as case study to highlight climate variability and its impact on water availability.

  15. Distinct structural neural patterns of trait physical and social anhedonia: evidence from cortical thickness, subcortical volumes and inter-regional correlations.

    PubMed

    Wang, Yi; Deng, Yi; Fung, Germaine; Liu, Wen-hua; Wei, Xin-hua; Jiang, Xin-qing; Lui, Simon S Y; Cheung, Eric F C; Chan, Raymond C K

    2014-12-30

    Anhedonia is an enduring trait accounting for the reduced capacity to experience pleasure. Few studies have investigated the brain structural features associated with trait anhedonia. In this study, the relationships between cortical thickness, volume of subcortical structures and scores on the Chapman physical and social anhedonia scales were examined in a non-clinical sample (n=72, 35 males). FreeSurfer was used to examine the cortical thickness and the volume of six identified subcortical structures related to trait anhedonia. We found that the cortical thickness of the superior frontal gyrus and the volume of the pallidum in the left hemisphere were correlated with anhedonia scores in both physical and social aspects. Specifically, positive correlations were found between levels of social anhedonia and the thickness of the postcentral and the inferior parietal gyri. Cortico-subcortical inter-correlations between these clusters were also observed. Our findings revealed distinct correlation patterns of neural substrates with trait physical and social anhedonia in a non-clinical sample. These findings contribute to the understanding of the pathologies underlying the anhedonia phenotype in schizophrenia and other psychiatric disorders.

  16. Annual primary production: Patterns and mechanisms of change in a nutrient-rich tidal ecosystem

    USGS Publications Warehouse

    Jassby, Alan D.; Cloern, James E.; Cole, B.E.

    2002-01-01

    Although nutrient supply often underlies long-term changes in aquatic primary production, other regulatory processes can be important. The Sacramento-San Joaquin River Delta, a complex of tidal waterways forming the landward portion of the San Francisco Estuary, has ample nutrient supplies, enabling us to examine alternate regulatory mechanisms over a 21-yr period. Delta-wide primary productivity was reconstructed from historical water quality data for 1975–1995. Annual primary production averaged 70 g C m−2, but it varied by over a factor of five among years. At least four processes contributed to this variability: (1) invasion of the clam Potamocorbula amurensis led to a persistent decrease in phytoplankton biomass (chlorophyll a) after 1986; (2) a long-term decline in total suspended solids—probably at least partly because of upstream dam construction—increased water transparency and phytoplankton growth rate; (3) river inflow, reflecting climate variability, affected biomass through fluctuations in flushing and growth rates through fluctuations in total suspended solids; and (4) an additional pathway manifesting as a long-term decline in winter phytoplankton biomass has been identified, but its genesis is uncertain. Overall, the Delta lost 43% in annual primary production during the period. Given the evidence for food limitation of primary consumers, these findings provide a partial explanation for widespread Delta species declines over the past few decades. Turbid nutrient-rich systems such as the Delta may be inherently more variable than other tidal systems because certain compensatory processes are absent. Comparisons among systems, however, can be tenuous because conclusions about the magnitude and mechanisms of variability are dependent on length of data record.  

  17. Mesosphere-thermosphere regions coupling with the lower atmosphere through the inter-annual variations of the hydroxyl OH(8-3) bands, the oxygen 557.7 nm and 630.0 nm lines nightglow intensities

    NASA Astrophysics Data System (ADS)

    Didebulidze, Goderdzi; Javakhishvili, Giorgi; Todua, Maya; Toriashvili, Lekso

    2016-04-01

    The characteristics of the inter-annual/seasonal distributions of the mid-latitude nightglow intensities of the mesopause hydroxyl OH(8-3) bands (maximum luminous layer about 87 km), the thermosphere oxygen green 557.7 nm (main maximum of luminous layer in the lower thermosphere at about 95 km) and the red 630.0 nm line (emitted from the ionosphere F2 region with maximum luminous layer about 230-280 km) intensities are considered by observations from Abastumani (41.75 E; 42.82 E). The observed inter-annual variations of the OH bands and green line, along with the maximal values at spring (March-April) and fall (September-October) equinoxial periods which are noticed also from other regions, exhibit maxima in June as well. The red line intensity mainly tends to decrease at equinoxial months, while it is maximal in summer and is accompanied by relatively small increase in June (compared to May and July). Maximal values of OH band and green line intensities in June are observed both in maximum and minimum phases of solar activity. This is considered as a manifestation of the features of upper and lower atmosphere dynamical coupling of this region of the South Caucasus. Such dynamical coupling can involve the ionosphere F2 region and can be accompanied by relative decrease of the red line intensity in June. It is observed that the increase of OH band and green line intensities is accompanied by the red line intensity decrease at the end of March and beginning of April, which also is considered as a manifestation of lower and upper atmosphere dynamical coupling. Acknowledgements: This work has been supported by Shota Rustaveli National Science Foundation Grants no. 31/56 and 31/81.

  18. Inter-annual and geographical variations in the extent of bare ice and dark ice on the Greenland ice sheet derived from MODIS satellite images

    NASA Astrophysics Data System (ADS)

    Shimada, Rigen; Takeuchi, Nozomu; Aoki, Teruo

    2016-04-01

    Areas of dark ice have appeared on the Greenland ice sheet every summer in recent years. These are likely to have a great impact on the mass balance of the ice sheet because of their low albedo. We report annual and geographical variations in the bare ice and dark ice areas that appeared on the Greenland Ice Sheet from 2000 to 2014 by using MODIS satellite images. The July monthly mean of the extent of bare ice showed a positive trend over these 15 years, and large annual variability ranging from 89,975 km2 to 279,075 km2, 5% and 16% of the entire ice sheet, respectively. The extent of dark ice also showed a positive trend and varied annually, ranging from 3,575 km2 to 26,975 km2, 4% and 10% of the bare ice extent. These areas are geographically varied, and their expansion is the greatest on the western side, particularly the southwestern side of the ice sheet. The bare ice extent correlates strongly with the monthly mean air temperature in July, suggesting that the extent was determined by snow melt. The dark ice extent also correlates with the air temperature; however, the correlation is weaker. The dark ice extent further correlates negatively with solar radiation. This suggests that the extent of dark ice is not only controlled by snow melt on the ice, but also by changes in the surface structures of the bare ice surface, such as cryoconite holes, which are associated with impurities appearing on the ice surface.

  19. Intra- and inter-annual uranium concentration variability in a Belizean stalagmite controlled by prior aragonite precipitation: A new tool for reconstructing hydro-climate using aragonitic speleothems

    NASA Astrophysics Data System (ADS)

    Jamieson, Robert A.; Baldini, James U. L.; Brett, Marianne J.; Taylor, Jessica; Ridley, Harriet E.; Ottley, Chris J.; Prufer, Keith M.; Wassenburg, Jasper A.; Scholz, Denis; Breitenbach, Sebastian F. M.

    2016-10-01

    Aragonitic speleothems are increasingly utilised as palaeoclimate archives due to their amenability to high precision U-Th dating. Proxy records from fast-growing aragonitic stalagmites, precisely dated to annual timescales, can allow investigation of climatic events occurring on annual or even sub-annual timescales with minimal chronological uncertainty. However, the behaviour of many trace elements, such as uranium, in aragonitic speleothems has not thus far been as well constrained as in calcitic speleothems. Here, we use uranium concentration shifts measured across primary calcite-to-aragonite mineralogical transitions in speleothems to calculate the distribution coefficient of uranium in aragonitic speleothems (derived DU = 3.74 ± 1.13). Because our calculated DU is considerably above 1 increased prior aragonite precipitation due to increased karst water residence time should strongly control stalagmite aragonite U/Ca values. Consequently, uranium concentrations in aragonitic speleothems should act as excellent proxies for effective rainfall. We test this using a high-resolution ICP-MS derived trace element dataset from a Belizean stalagmite. YOK-G is an aragonitic stalagmite from Yok Balum cave in Belize with an extremely robust monthly-resolved chronology built using annual δ13C cycles. We interpret seasonal U/Ca variations in YOK-G as reflecting changes in the amount and seasonality of prior aragonite precipitation driven by variable rainfall amounts. The U/Ca record strongly suggests that modern drying has occurred in Belize, and that this drying was primarily caused by a reduction in wet season rainfall. This is consistent with published stable isotope data from YOK-G also very strongly suggesting modern rainfall reductions, previously interpreted as the result of southward ITCZ displacement. Our results strongly suggest that U/Ca values in aragonitic speleothems are excellent proxies for rainfall variability. This new tool, combined with the

  20. Climatic controls on hurricane patterns: a 1200-y near-annual record from Lighthouse Reef, Belize

    NASA Astrophysics Data System (ADS)

    Denommee, K. C.; Bentley, S. J.; Droxler, A. W.

    2014-01-01

    Tropical cyclones (TCs) are powerful agents of destruction, and understanding climatic controls on TC patterns is of great importance. Over timescales of seasons to several decades, relationships among TC track, frequency, intensity and basin-scale climate changes are well documented by instrumental records. Over centuries to millennia, climate-shift influence on TC regimes remains poorly constrained. To better understand these relationships, records from multiple locations of TC strikes spanning millennia with high temporal resolution are required, but such records are rare. Here we report on a highly detailed sedimentary proxy record of paleo-TC strikes from the Blue Hole of Lighthouse Reef, Belize. Our findings provide an important addition to other high-resolution records, which collectively demonstrate that shifts between active and inactive TC regimes have occurred contemporaneously with shifts hemispheric-scale oceanic and atmospheric circulation patterns such as MDR SSTs and NAO mode, rather than with changes in local climate phenomena as has previously been suggested.

  1. Climatic controls on hurricane patterns: a 1200-y near-annual record from Lighthouse Reef, Belize.

    PubMed

    Denommee, K C; Bentley, S J; Droxler, A W

    2014-01-27

    Tropical cyclones (TCs) are powerful agents of destruction, and understanding climatic controls on TC patterns is of great importance. Over timescales of seasons to several decades, relationships among TC track, frequency, intensity and basin-scale climate changes are well documented by instrumental records. Over centuries to millennia, climate-shift influence on TC regimes remains poorly constrained. To better understand these relationships, records from multiple locations of TC strikes spanning millennia with high temporal resolution are required, but such records are rare. Here we report on a highly detailed sedimentary proxy record of paleo-TC strikes from the Blue Hole of Lighthouse Reef, Belize. Our findings provide an important addition to other high-resolution records, which collectively demonstrate that shifts between active and inactive TC regimes have occurred contemporaneously with shifts hemispheric-scale oceanic and atmospheric circulation patterns such as MDR SSTs and NAO mode, rather than with changes in local climate phenomena as has previously been suggested.

  2. Overestimation of soil CO2 fluxes from closed chamber measurements at low atmospheric turbulence biases the diurnal pattern and the annual soil respiration budget

    NASA Astrophysics Data System (ADS)

    Braendholt, Andreas; Steenberg Larsen, Klaus; Ibrom, Andreas; Pilegaard, Kim

    2016-04-01

    Precise quantification of the diurnal and seasonal variation of soil respiration (Rs) is crucial to correctly estimate annual soil carbon fluxes as well as to correctly interpret the response of Rs to biotic and abiotic factors on different time scale. In this study we found a systematic effect of low atmospheric turbulence on continuous hourly Rs measurements with closed chambers throughout one year in a temperate Danish beech forest. Using friction velocity (u⋆) measured at the site above the canopy, we filtered out chamber flux data measured at low atmospheric turbulence. The non-filtered data showed a clear diurnal pattern of Rs across all seasons with highest fluxes during night time suggesting an implausible negative temperature sensitivity of Rs. When filtering out data at low turbulence, the annually averaged diurnal pattern changed, such that the highest Rs fluxes were seen during day time, i.e. following the course of soil temperatures. This effect on the diurnal pattern was due to low turbulence primarily occurring during night time. We calculated different annual Rs budgets by filtering out fluxes for different levels of u⋆. The highest annual Rs budget was found when including all data and it decreased with an increasing u⋆ filter threshold. Our results show that Rs was overestimated at low atmospheric turbulence throughout the year and that this overestimation considerably biased the diurnal pattern of Rs and led to an overestimation of the annual Rs budget. Thus we recommend that that any analysis of the diurnal pattern of Rs must consider overestimation of Rs at low atmospheric turbulence, to yield unbiased diurnal patterns. This is crucial when investigating temperature responses and potential links between CO2 production and Rs on a short time scale, but also for correct estimation of annual Rs budgets. Acknowledgements: This study was funded by the free Danish Ministry for Research, Innovation and higher Education, the free Danish Research

  3. Origins of streamflow in a crystalline basement catchment in a sub-humid Sudanian zone: The Donga basin (Benin, West Africa): Inter-annual variability of water budget

    NASA Astrophysics Data System (ADS)

    Séguis, L.; Kamagaté, B.; Favreau, G.; Descloitres, M.; Seidel, J.-L.; Galle, S.; Peugeot, C.; Gosset, M.; Le Barbé, L.; Malinur, F.; Van Exter, S.; Arjounin, M.; Boubkraoui, S.; Wubda, M.

    2011-05-01

    SummaryDuring the last quarter of the 20th century, West Africa underwent a particularly intense and generalized drought. During this period, the biggest drops in streamflow were observed in the Sudanian zone rather than in the Sahelian zone, but the reasons are still poorly understood. In 2000, a meso-scale hydrological observatory was set up in the sub-humid Sudanian zone of the Upper Ouémé Valley (Benin). Three embedded catchments of 12-586 km 2 located on a crystalline bedrock were intensively instrumented to document the different terms of the water budget and to identify the main streamflow generating processes and base-flow mechanisms at different scales. Geophysical, hydrological and geochemical data were collected throughout the catchments from 2002 to 2006. Crossing these data helped define their hydrological functioning. The region has seasonal streamflow, and the permanent groundwater in the weathered mantle does not drain to rivers, instead, seasonal perched groundwaters are the major contributor to annual streamflow. The perched groundwaters are mainly located in seasonally waterlogged sandy layers in the headwater bottom-lands called bas-fonds in French-speaking West Africa of 1st order streams. During the period 2003-2006, regolith groundwater recharge ranged between 10% and 15% of the annual rainfall depth. Depletion of permanent groundwater during the dry season is probably explained by local evapotranspiration which was seen not to be limited to gallery forests. During the 4-year study period, a reduction of 20% in annual rainfall led to a 50% reduction in streamflow. This reduction was observed in the two components of the flow: direct runoff and drainage of perched groundwater. Thanks to the comprehensive dataset obtained, the results obtained for the Donga experimental catchment are now being extrapolated to the whole upper Ouémé valley, which can be considered as representative of sub-humid Sudanian rivers flowing on a crystalline

  4. Climatic controls on hurricane patterns: a 1200-y near-annual record from Lighthouse Reef, Belize

    PubMed Central

    Denommee, K. C.; Bentley, S. J.; Droxler, A. W.

    2014-01-01

    Tropical cyclones (TCs) are powerful agents of destruction, and understanding climatic controls on TC patterns is of great importance. Over timescales of seasons to several decades, relationships among TC track, frequency, intensity and basin-scale climate changes are well documented by instrumental records. Over centuries to millennia, climate-shift influence on TC regimes remains poorly constrained. To better understand these relationships, records from multiple locations of TC strikes spanning millennia with high temporal resolution are required, but such records are rare. Here we report on a highly detailed sedimentary proxy record of paleo-TC strikes from the Blue Hole of Lighthouse Reef, Belize. Our findings provide an important addition to other high-resolution records, which collectively demonstrate that shifts between active and inactive TC regimes have occurred contemporaneously with shifts hemispheric-scale oceanic and atmospheric circulation patterns such as MDR SSTs and NAO mode, rather than with changes in local climate phenomena as has previously been suggested. PMID:24464265

  5. In Search of the E. coli Compounds that Change the Antibiotic Production Pattern of Streptomyces coelicolor During Inter-species Interaction.

    PubMed

    Mavituna, Ferda; Luti, Khalid Jaber Kadhum; Gu, Lixing

    2016-08-01

    The aim of this work was to investigate the interaction between E.coli and Streptomyces coelicolor A3 (2) for the increased production of undecylprodigiosin and identify the E. coli actives mediating this inter-species interaction. The antibiotics of interest were the red-pigmented undecylprodigiosin and blue-pigmented actinorhodin. Pure cultures of S. coelicolor in a defined medium produced higher concentrations of actinorhodin compared to those of undecylprodigiosin. The latter however, is more important due to its immunosuppressive and antitumor properties. As a strategy to increase undecylprodigiosin production, we added separately, live cells and heat-killed cells of E. coli C600, and the cell-free supernatant of E. coli culture to S. coelicolor cultures in shake flasks. The interaction with live cells of E. coli altered the antibiotic production pattern and undecylprodigiosin production was enhanced by 3.5-fold compared to the pure cultures of S. coelicolor and actinorhodin decreased by 15-fold. The heat-killed cells of E. coli however, had no effect on antibiotic production. In all cases, growth and glucose consumption of S. coelicolor remained almost the same as those observed in the pure culture indicating that the changes in antibiotic production were not due to nutritional stress. Results with cell-free supernatant of E. coli culture indicated that the interaction between S. coelicolor and E. coli was mediated via diffusible molecule(s). Using a set of extraction procedures and agar-well diffusion bioassays, we isolated and preliminarily identified a class of compounds. For the preliminary verification, we added the compound which was the common chemical structural moiety in this class of compounds to the pure S. coelicolor cultures. We observed similar effects on antibiotic production as with the live E. coli cells and their supernatant indicating that this class of compounds secreted by E. coli indeed could act as actives during interspecies

  6. Rainfall Control of Karst Solution and the Inter/Intra Annual Hydrogeochemical Evolution of Cave Dripwater: A Long-term, Site-specific Study, Soreq Cave, Israel

    NASA Astrophysics Data System (ADS)

    Burstyn, Yuval; Bar-Matthews, Miryam; Ayalon, Avner; Matthews, Alan

    2016-04-01

    Speleothem laminae preserve climate information transferred to the cave via dripwater. High spatial resolution methods allow in situ measurement of geochemical and isotopic proxies at seasonal resolution. Existing hydrogeochemical calibration models suggest that high rainfall inhibits karst water chemical evolution, resulting in low δ 18O values, and low Mg/Ca and Sr/Ca ratios that are not necessarily correlated. Drought periods display opposite chemical behaviour owing to lower infiltration rates and increased Prior Calcite Precipitation (PCP). This study aims to provide a site-specific, high-resolution hydrogeochemical calibration for the Soreq Cave. We examine four sites that were continuously sampled since 1990. Four main rainfall conditions are characterized: very wet years, average, drought and very dry years. Two sites are fed by 'fast drips', which only become active after ˜ 250mm rainfall has accumulated since the beginning of the winter season. Two sites, located deeper in the cave, are fed by 'slow drips' that are active all year round. Drip rate measurements identify two main reservoirs - fissure and matrix - that mainly differ in residence time. The δ 18O of fissure water is closer to that of mean annual rainfall (˜ -6 ‰VSMOW), while matrix values are higher (˜ -3.5 ‰VSMOW). Two main Sr and Mg sources are identified - dolomitic bedrock (Mg/Ca ˜ 700 mM/M, Sr/Ca ˜ 0.4 mM/M) and soil leachate (Mg/Ca ˜ 300 mM/M, Sr/Ca ˜ 1.1 mM/M). Most cave dripwater evolves from ˜ 1:1 soil-bedrock solution. PCP effect on dripwater solution at each site is estimated by comparing the ln(Mg/Ca) vs ln(Sr/Ca) linear slope to the PCP slope calculated using cave specific D(Mg) and D(Sr). Soreq Cave PCP slope is similar to the global slope of 0.88± 0.13. The composition and chemical evolution of each reservoir and its contribution to water influx at each site is primarily governed by annual effective infiltration. Higher seasonal amplitude in δ 18O, Mg/Ca and Sr

  7. Using Novel Approaches in Process-Based Modeling for Interpreting Inter-Annual Variability in Tree Ring Widths, Wood Density Profiles, and Cellulose Isotopic Ratios

    NASA Astrophysics Data System (ADS)

    Friend, A. D.; Babst, F.; Belmecheri, S.; Frank, D. C.; Hacket Pain, A. J.; Hayat, A.; Poulter, B.; Rademacher, T. T.; Trouet, V.

    2015-12-01

    Time series annual of tree ring width, density variation, and oxygen and carbon isotopic compositions have the potential to substantially increase our knowledge of forest responses to environmental variation. However, their interpretation is not straightforward due to the simultaneous influences of a number of confounding factors, including carry-over effects from previous years, variable resource allocation with size, age, and canopy position, species-specific physiologies, and complex interactions between forcings such as temperature, soil moisture, and atmospheric CO2. Here we attempt to tease these factors apart and so substantially improve the interpretability of tree ring archives through the construction and application of novel approaches within a process-based model of individual tree growth. The model incorporates descriptions of xylem cell division, expansion, and secondary wall thickening, apical and lateral meristem activities with internal controls from internal signals, internal carbon storage, and the dynamics of canopy photosynthesis, stomatal movements, evapotranspiration, canopy temperatures, and soil moisture. Alternative treatments of isotopic fractionation and growth controls are evaluated using measured datasets. We demonstrate how this new model approach can be used to assess the information contained in tree rings concerning the influence of increasing atmospheric CO2 over the past century on growth and water use efficiency at a range of sites.

  8. Mercury in the Blue Marlin (Makaira nigricans) from the Southern Gulf of California: Tissue Distribution and Inter-Annual Variation (2005-2012).

    PubMed

    Vega-Sánchez, B; Ortega-García, S; Ruelas-Inzunza, J; Frías-Espericueta, M; Escobar-Sánchez, O; Guzmán-Rendón, J

    2017-02-01

    With the aim of knowing annual variations of Hg concentrations in muscle and liver of blue marlin (Makaira nigricans) from the southern Gulf of California, fish were collected between 2005 and 2012 in three areas. In general, Hg levels were more elevated in liver than in muscle. Variations of Hg concentrations in muscle and liver among the studied years were not significant. Hg levels in muscle and liver increased significantly with length and weight of fish. In comparison to other studies, Hg levels in muscle and liver were lower. With respect to maximum permissible limits (1.0 µg g(-1) wet weight) of Hg in Mexico, the average concentration (1.91 µg g(-1) wet weight) in the edible portion (muscle) of blue marlin was over the legal limit; this issue is worth research efforts in relation to the rate of ingestion of this species and the co-occurrence of selenium in the edible portion.

  9. Assessing Seasonal and Inter-Annual Variations of Lake Surface Areas in Mongolia during 2000-2011 Using Minimum Composite MODIS NDVI

    PubMed Central

    Kang, Sinkyu; Hong, Suk Young

    2016-01-01

    A minimum composite method was applied to produce a 15-day interval normalized difference vegetation index (NDVI) dataset from Moderate Resolution Imaging Spectroradiometer (MODIS) daily 250 m reflectance in the red and near-infrared bands. This dataset was applied to determine lake surface areas in Mongolia. A total of 73 lakes greater than 6.25 km2in area were selected, and 28 of these lakes were used to evaluate detection errors. The minimum composite NDVI showed a better detection performance on lake water pixels than did the official MODIS 16-day 250 m NDVI based on a maximum composite method. The overall lake area detection performance based on the 15-day minimum composite NDVI showed -2.5% error relative to the Landsat-derived lake area for the 28 evaluated lakes. The errors increased with increases in the perimeter-to-area ratio but decreased with lake size over 10 km2. The lake area decreased by -9.3% at an annual rate of -53.7 km2 yr-1 during 2000 to 2011 for the 73 lakes. However, considerable spatial variations, such as slight-to-moderate lake area reductions in semi-arid regions and rapid lake area reductions in arid regions, were also detected. This study demonstrated applicability of MODIS 250 m reflectance data for biweekly monitoring of lake area change and diagnosed considerable lake area reduction and its spatial variability in arid and semi-arid regions of Mongolia. Future studies are required for explaining reasons of lake area changes and their spatial variability. PMID:27007233

  10. Assessing Seasonal and Inter-Annual Variations of Lake Surface Areas in Mongolia during 2000-2011 Using Minimum Composite MODIS NDVI.

    PubMed

    Kang, Sinkyu; Hong, Suk Young

    2016-01-01

    A minimum composite method was applied to produce a 15-day interval normalized difference vegetation index (NDVI) dataset from Moderate Resolution Imaging Spectroradiometer (MODIS) daily 250 m reflectance in the red and near-infrared bands. This dataset was applied to determine lake surface areas in Mongolia. A total of 73 lakes greater than 6.25 km2in area were selected, and 28 of these lakes were used to evaluate detection errors. The minimum composite NDVI showed a better detection performance on lake water pixels than did the official MODIS 16-day 250 m NDVI based on a maximum composite method. The overall lake area detection performance based on the 15-day minimum composite NDVI showed -2.5% error relative to the Landsat-derived lake area for the 28 evaluated lakes. The errors increased with increases in the perimeter-to-area ratio but decreased with lake size over 10 km(2). The lake area decreased by -9.3% at an annual rate of -53.7 km(2) yr(-1) during 2000 to 2011 for the 73 lakes. However, considerable spatial variations, such as slight-to-moderate lake area reductions in semi-arid regions and rapid lake area reductions in arid regions, were also detected. This study demonstrated applicability of MODIS 250 m reflectance data for biweekly monitoring of lake area change and diagnosed considerable lake area reduction and its spatial variability in arid and semi-arid regions of Mongolia. Future studies are required for explaining reasons of lake area changes and their spatial variability.

  11. Productivity and phenological responses of natural vegetation to present and future inter-annual climate variability across semi-arid river basins in Chile.

    PubMed

    Glade, Francisco E; Miranda, Marcelo D; Meza, Francisco J; van Leeuwen, Willem J D

    2016-12-01

    Time series of vegetation indices and remotely sensed phenological data offer insights about the patterns in vegetation dynamics. Both are useful sources of information for analyzing and monitoring ecosystem responses to environmental variations caused by natural and anthropogenic drivers. In the semi-arid region of Chile, climate variability and recent severe droughts in addition to land-use changes pose threats to the stability of local ecosystems. Normalized difference vegetation index time series (2000-2013) data from the moderate resolution imaging spectroradiometer (MODIS) was processed to monitor the trends and patterns of vegetation productivity and phenology observed over the last decade. An analysis of the relationship between (i) vegetation productivity and (ii) precipitation and temperature data for representative natural land-use cover classes was made. Using these data and ground measurements, productivity estimates were projected for two climate change scenarios (RCP2.6 and RCP8.5) at two altitudinal levels. Results showed negative trends of vegetation productivity below 2000 m a.s.l. and positive trends for higher elevations. Phenology analysis suggested that mountainous ecosystems were starting their growing period earlier in the season, coinciding with a decreased productivity peak during the growing season. The coastal shrubland/grassland land cover class had a significant positive relation with rainfall and a significant negative relation with temperature, suggesting that these ecosystems are vulnerable to climate change. Future productivity projections indicate that under an RCP8.5 climate change scenario, productivity could decline by 12% in the period of 2060-2100, leading to a severe vegetation degradation at lower altitudes and in drier areas.

  12. Grape harvest and yield responses to inter-annual changes in temperature and precipitation in an area of north-east Spain with a Mediterranean climate.

    PubMed

    Camps, Josep Odó; Ramos, María Concepción

    2012-09-01

    This study presents an analysis of temperature and precipitation trends and their impact on grape harvests in the Penedès region (NE Spain). It includes analyses of maximum, minimum and mean daily temperatures (for both the growing and ripening seasons) and daily rainfall (for the hydrological year, the growing season and each phenological stage) for three observatories in the immediate area. We analysed a series of factors: beginning and end harvest dates; the day on which a given potential alcoholic degree was reached; and yield for several varieties of grape grown in the area in relation to climatic variables. Maximum temperatures increased at all the observatories, with greater values being recorded in recent years (1996-2009) than in previous decades (1960s-2000s): we observed increases in average growing season temperatures of 0.11°C per year for the period 1996-2009 vs 0.04°C per year for the period 1960-2009 at Vilafranca del Penedès. These temperature changes were due mainly to increases in maximum temperatures and an increase in the incidence of extreme heat (number of days with T > 30°C). Crop evapotranspiration also increased significantly during the same period. The Winkler index also increased, so the study area would correspond to region IV according to that climatic classification. There were no significant trends in annual rainfall but rainfall recorded between bloom and veraison decreased significantly at the three observatories, with the greatest decrease corresponding to the period 1996-2009. The dates on which harvests started and ended showed a continuous advance (of between -0.7 and -1.1 days per year, depending on the variety), which was significantly correlated with the average mean and maximum daily growing season temperatures (up to -7.68 days for 1°C increase). Winegrape yield was influenced by the estimated water deficit (crop evapotranspiration minus precipitation) in the bloom-veraison period; this value increased due to a

  13. Grape harvest and yield responses to inter-annual changes in temperature and precipitation in an area of north-east Spain with a Mediterranean climate

    NASA Astrophysics Data System (ADS)

    Camps, Josep Odó; Ramos, María Concepción

    2012-09-01

    This study presents an analysis of temperature and precipitation trends and their impact on grape harvests in the Penedès region (NE Spain). It includes analyses of maximum, minimum and mean daily temperatures (for both the growing and ripening seasons) and daily rainfall (for the hydrological year, the growing season and each phenological stage) for three observatories in the immediate area. We analysed a series of factors: beginning and end harvest dates; the day on which a given potential alcoholic degree was reached; and yield for several varieties of grape grown in the area in relation to climatic variables. Maximum temperatures increased at all the observatories, with greater values being recorded in recent years (1996-2009) than in previous decades (1960s-2000s): we observed increases in average growing season temperatures of 0.11°C per year for the period 1996-2009 vs 0.04°C per year for the period 1960-2009 at Vilafranca del Penedès. These temperature changes were due mainly to increases in maximum temperatures and an increase in the incidence of extreme heat (number of days with T > 30°C). Crop evapotranspiration also increased significantly during the same period. The Winkler index also increased, so the study area would correspond to region IV according to that climatic classification. There were no significant trends in annual rainfall but rainfall recorded between bloom and veraison decreased significantly at the three observatories, with the greatest decrease corresponding to the period 1996-2009. The dates on which harvests started and ended showed a continuous advance (of between -0.7 and -1.1 days per year, depending on the variety), which was significantly correlated with the average mean and maximum daily growing season temperatures (up to -7.68 days for 1°C increase). Winegrape yield was influenced by the estimated water deficit (crop evapotranspiration minus precipitation) in the bloom-veraison period; this value increased due to a

  14. Reconstructing inter annual Indonesian river discharge by high-resolution LA-ICPMS geochemistry and UV-luminescence scanning of corals

    NASA Astrophysics Data System (ADS)

    Nagtegaal, R.; Bergh, van den, G.; Pascher, K.; Jochum, K. P.; Brummer, G. A.

    2011-12-01

    Degradation of many coral reefs around the world is linked to land-based activities. Soil erosion due to land-use changes results in increased quantities of sediment to local river systems which are, in many cases, discharged directly onto the reefs systems. The Berau delta/barrier reef system, located offshore NE Kalimantan, Indonesia, is characterized by a unique and pristine reef system that exists in close proximity of the Berau river mouth. Over the last decades deforestation and mining activities have considerably increased in the region. Our project aimed to assess the impact of those land-use changes in relation to sediment supply to the reef system over the last decades. Corals archive historical sedimentation records as they entrap terrigenous sediments into their skeleton and thus can be used to identify periods of decreased or enhanced sediment supply associated with anthropogenic induced land-use changes and natural variations in freshwater discharge. We investigate cores drilled from living Porites sp. coral colonies collected in the North Eastern part of the Berau delta >20 km from the river mouth. The annually banded cores were analyzed for Ba/Ca and Y/Ca ratios using LA-ICPMS in combination with spectral luminescence scanning (SLS) as a measure for terrestrial sediment input and soil erosion. Three coral luminescence records were used to establish a 28-year composite record of sediment discharge. The year to year variability of sediment supply to the reef system is evidently regulated by the El Niño Southern Oscillation climate system (ENSO). Especially positive phases of the Nino 3.4 index (= El Niño) have a strong negative effect on the sediment supply to the reef system which clearly diminished during the El Niño years 82-83, 92 and 97-98. We also conclude that for the Berau region, Y/Ca rather than Ba/Ca correlates well with precipitation records which is supported by the relation to the spectral luminescence results. Despite the fact that

  15. Characterizing intra and inter annual variability of storm events based on very high frequency monitoring of hydrological and chemical variables: what can we learn about hot spots and hot moments from continuous hydro-chemical sensors ?

    NASA Astrophysics Data System (ADS)

    Fovet, O.; Thelusma, G.; Humbert, G.; Dupas, R.; Jaffrezic, A.; Grimaldi, C.; Faucheux, M.; Gilliet, N.; Hamon, Y.; Gruau, G.

    2015-12-01

    Storm events are hot moments of emission for several dissolved and particulate chemical species at major stake for water quality (e.g. dissolved organic carbon DOC, suspended sediments, phosphorus, NH4). During such events, the solutes or particles are exported from heterogeneous sources through various pathways to stream or are possibly stored in retention hot spots temporary. This leads to specific integrated signals at the outlet at the scale of storm events. The dynamics of such events are also very short especially in headwater catchments where their total duration ranges over 10h to 3 days, with very quick variations in stream flow and concentrations at the outlet occurring in a few hours. Thus for investigating properly event processes, high frequency monitoring of flow and water quality is required. We analysed 103 storm events in a 5 km2 agricultural headwater catchment, part of the AgrHys Observatory, on the basis of a 3-year-long data set which combined meterological (Rainfall), hydrological (flow and piezometry), and water quality (turbidity, conductivity, DOC and NO3 concentrations) data recorded at very high frequencies (from 1 to 20 min) thanks to dedicated sensors. We described the storm events using simple (1 variable) and combined (2 variables) descriptors for characterizing level and dynamics of flow (Q), groundwater levels, and concentrations (C) but also the C-Q relationships. Three intra annual periods have been previously defined for base flow dynamic according to shallow groundwater table variations so that they correspond to different connectivity status in the catchment. The seasonal and inter-annual variability of the storm events have been analysed using the descriptors and based on these predefined periods. Principal component analysis based on storm chemical descriptors led to discriminate these three seasons while storm hydrological descriptors are less variable between them. Finally we used a clustering method to build a typology of

  16. A 150 year record of inter-annual climate variability and organic carbon burial in Santa Monica and Santa Barbara Basins

    SciTech Connect

    Hagadorn, J.W.; Stott, L.D.; Sinha, A.; Rincon, M. . Dept. of Geological Sciences); Schimmelmann, A. . Scripps Inst. of Oceanography)

    1992-01-01

    Stable isotopic measurements were conducted on total organic carbon (TOC) and fossil planktonic foraminifera in laminated sediments collected from Santa Monica and Santa Barbara Basins, California Borderland, in order to investigate relationships between climatic variability and organic carbon burial. These data currently provide biannual sample resolution back to 1750 AD. During the past 150 years, there has been a positive covariance between the carbon isotopic composition of fossil planktonic foraminifera and of TOC. Periods of increased delta C-13 of TOC and foraminifera correspond to higher organic carbon burial in Santa Monica and Santa Barbara Basins. When combined, these patterns are interpreted as variation in productivity within the basins. Isotopic variability in TOC and planktonic foraminifera is significantly higher prior to 1900 AD. Although spring sea surface temperatures were also significantly more variable during this period, the authors do not recognize a systematic relationship between temperature and organic carbon burial. Spectral analysis of isotopic compositions of fossil foraminifera calcite, TOC, organic carbon burial and lamination frequency in the sediments reveal distinct spectral peaks at 5 and 7.7 years, corresponding to ENSO/El Nino frequencies. Additional spectral peaks occur at 19 and 20 years. Previous time series analyses of tree ring width records indicate similar decadal-scale frequencies and suggest a possible link to solar and/or lunar nodal tidal cycles. While these initial results suggest a relationship between climate-cyclicity, primary productivity and organic carbon burial, the phase relationship cannot be deciphered from this preliminary data set.

  17. Utilizing continuous measurements of delta^{13}C_r, delta18O_r, and net ecosystem exchange of CO_2 and H_2O to understand the effects of inter-annual variability in drought on ecosystem functioning

    NASA Astrophysics Data System (ADS)

    Osuna, J. L.; McDowell, N. G.; Shim, J. H.; Rahn, T.; Pockman, W.

    2011-12-01

    In the semi-arid Southwestern US, seasonal drought has strengthened in recent years due to both a decrease in winter precipitation and delayed onset of the summer monsoon. A process-based understanding of ecosystem response to increased drought stress is vital to predicting the long-term stability of semi-arid biomes. To understand the processes responsible for inter-annual and seasonal variability in net ecosystem carbon and water fluxes, we compared nearly continuous measurements of ecosystem scale respiration (R_e) from an eddy covariance system with the stable carbon and oxygen isotope signals in ecosystem respired CO_2 (delta^{13}C_r and delta^{18}O_r) measured continuously by a tunable diode laser spectrometer (TDL) sampling at various canopy heights at the same site. The study site, at Los Alamos National Laboratory, converted from pitilde{n}on juniper woodland to juniper woodland after over 90% of pitilde{n}ons died in 2002-2003 following multiple years of enhanced drought leaving a high necromass at the site. We analyzed the relationships between the Bowen ratio, delta^{18}O_r, daily and annual accumulated NEE, and delta^{13}C_r to understand the (de)coupling between the response of transpiration and respiration under varying degrees of drought stress. Additionally, we explored the variability in the lag and intensity of ecosystem response to precipitation pulses depending on antecedent conditions. The response of delta^{18}O_r was more consistent across years and seasons whereas variability in the contribution of autotrophic versus heterotrophic respiration appeared to cause differing responses of delta^{13}C_r to drought stress and precipitation pulses. This result was supported by the diurnal CO_2 and H_2O fluxes indicating nearly immediate transpirational water loss initiated by most precipitation pulses. Annual accumulated precipitation (versus pulse size) was a better indicator of delta^{13}C_ r response (i.e. relative contributions of autotrophic

  18. Atmospheric deposition as an important nitrogen load to a typical agro-ecosystem in the Huang-Huai-Hai Plain. 2. Seasonal and inter-annual variations and their implications (2008-2012)

    NASA Astrophysics Data System (ADS)

    Huang, Ping; Zhang, Jiabao; Ma, Donghao; Wen, Zhaofei; Wu, Shengjun; Garland, Gina; Pereira, Engil Isadora Pujol; Zhu, Anning; Xin, Xiuli; Zhang, Congzhi

    2016-03-01

    Atmospheric nitrogen (N) deposition, an important N source to agro-ecosystems, has increased intensively in China during recent decades. However, knowledge on temporal variations of total N deposition and their influencing factors is limited due to lack of systematic monitoring data. In this study, total N deposition, including dry and wet components, was monitored using the water surrogate surface method for a typical agro-ecosystem with a winter wheat (Triticum aestivum L.) and summer maize (Zea mays L.) rotation system in the Huang-Huai-Hai Plain from May 2008 to April 2012. The results indicated that annual total N deposition ranged from 23.8 kg N ha-1 (2009-2010) to 40.3 kg N ha-1 (2008-2009) and averaged 31.8 kg N ha-1. Great inter-annual variations were observed during the sampling period, due to differences in annual rainfall and gaseous N losses from farmlands. Monthly total N deposition varied greatly, from less than 0.6 kg N ha-1 (January, 2010) to over 8.0 kg N ha-1 (August, 2008), with a mean value of 2.6 kg N ha-1. In contrast to wet deposition, dry portions generally contributed more to the total, except in the precipitation-intensive months, accounting for 65% in average. NH4+ -N was the dominant species in N deposition and its contribution to total deposition varied from 6% (December, 2009) to 79% (July, 2008), averaging 53%. The role of organic N (O-N) in both dry and wet deposition was equal to or even greater than that of NO3- -N. Influencing factors such as precipitation and its seasonal distribution, reactive N sources, vegetation status, field management practices, and weather conditions were responsible for the temporal variations of atmospheric N deposition and its components. These results are helpful for reducing the knowledge gaps in the temporal variations of atmospheric N deposition and their influencing factors in different ecosystems, to improve the understandings on N budget in the typical agro-ecosystem, and to provide references

  19. Seasonal and inter-annual eutrophication dynamics in a hypereutrophic shallow coastal lagoon from ten years of satellite observations and in-situ data

    NASA Astrophysics Data System (ADS)

    Pitarch, Jaime; Ruiz-Verdú, Antonio; Soria, Juan M.; Santoleri, Rosalia

    2016-04-01

    The Albufera de Valencia (39.33 N, 0.37 W) is a hypereutrophic shallow coastal lagoon, having a near round shape of ~ 5 km diameter and ~ 1 m average depth. At the west side, the lake is separated from the sea by a narrow land strip, but three artificial channels allow connection to the sea, regulated by gates. The rest of the lake is surrounded by rice fields that were made by gaining surface from the lake around a century ago. Nowadays, the ecological state of the lake is very degraded. Freshwater inflow is insufficient and residence time is too high. Despite some improvements in waste water treatment, high loads of sediment-stored nutrients are often resuspended due to habitual strong winds and made available for primary production. The previously abundant bottom vegetation disappeared decades ago and secchi depth does not reach more than few tens of centimeters. The lake suffers from cyanobacterial blooms and massive fish deaths. Despite its vital importance as a coastal wetland in the western Mediterranean region, its water quality is not routinely monitored, so its seasonality and eventual blooming events have not been sistematically studied. In this study, we aim at filling this gap using satellite data. Medium-resolution satellite-borne sensors constitute an appropriate tool for this sake due to the lake's medium size and little cloud cover time over the region. In particular, the European MERIS sensor (2002-2012) is specially well suited due to its unique spectral bands configuration for cyanobacterial detection. Apart from the utility of the results themselves, study of this sensor provides a strong baseline for operational utilization of its successor, the new-coming European Sentinel 3-OLCI sensor. We have processed the full archived MERIS archived data. By adequate choice of band ratios and posterior calibration to in-situ samples, the time series of chlorophyll concentration is derived. Derived seasonality reveals a pattern that is determined by the

  20. Effect of climate, intra and inter-annual variability, on nutrients emission (C,N, P) in stream water: lessons from an agricultural long term observatory of the temperate zone

    NASA Astrophysics Data System (ADS)

    Gascuel-Odoux, Chantal; Remi, Dupas; Patrick, Durand; Ophélie, Fovet; Gerard, Gruau; Anne, Jaffrezic; Guillaume, Humbert; Philippe, Merot; Gu, Sen

    2016-04-01

    Agriculture greatly contributes to modify C, N and P cycles, particularly in animal breeding regions due to high inputs. Climatic conditions, intra and inter-annual variabilities, modify nutrient stream water emissions, acting in time on transfer and transformation, accumulation and mobilization processes, connecting and disconnecting in time different compartments (soil, riparian areas, groundwater). In agricultural catchments, nutrient perturbations are dominated by agricultural land use, and decoupling human activities and climate effects is far from easy. Climate change generally appears as a secondary driver compared to land use. If studied, generally only one nutrient is considered. Only long term, high frequency and multiple element data series can decouple these two drivers. The Kervidy-Naizin watershed belongs to the AgrHyS environmental research observatory (http://www6.inra.fr/ore_agrhys_eng), itself included in RBV (French catchment network of the CZO). On this catchment, 6 years of daily data on DOC, NO3, SRP, TP concentrations allow us to analyze the effect of seasonal and inter-annual climatic variabilities on water quality (C, N, P). Different papers have been published on the effect of climate on nitrate (Molenat et al, 2008), SRP and TP (Dupas et al, 2015) and DOC (Humbert et al, 2015). We will present first results comparing the effect of climate on these three major solute forms of C, N and P. While C and P dynamics are very close and controlled by fluctuation of water table downslope, i.e. in riparian areas, mobilizing C and P in time, nitrate dynamics is controlled by GW dynamics upslope acting as the major N reservoir. As example, the dryness conditions in summer appears a key factor of the C and P emissions in autumn. All the three solute forms interact when anoxic conditions are observed in riparian zones. These basic processes explain how climatic variability can influence and explain interactions between C, N and P emissions in stream

  1. Bidirectional recovery patterns of Mojave Desert vegetation in an aqueduct pipeline corridor after 36 years: II. Annual plants

    USGS Publications Warehouse

    Berry, Kristin H.; Mack, Jeremy S.; Weigand, James F.; Gowan, Timothy A.; LaBerteaux, Denise

    2015-01-01

    We studied recovery of winter annual plants in a 97-m wide disturbed aqueduct corridor in the Mojave Desert 36 years after construction. We established plots at 0, 20, and 40 m from the road verge at the corridor center and at 100 m in undisturbed vegetation. We recorded 47 annual species, of which 41 were native and six were exotic. Exotic species composed from 64 to 91% of total biomass. We describe a bilateral process of recovery: from the road verge to the outward edge of the corridor and from undisturbed habitat into the corridor. Native annual plants significantly increased in richness from road verge to undisturbed vegetation, but not in density, biomass, or cover. In contrast, exotic annual plants increased in density, biomass, cover and richness with increasing distance from the road verge. The species of colonizing shrubs and type of canopy cover affected density, biomass, and richness of annuals. Species composition of native annuals differed significantly by distance, suggesting secondary succession. In general, native annuals were closer to achieving recovery on the 40-m plots than at the road verge. Recovery estimates were in centuries and dependent on location, canopy type, and whether considering all annuals or natives only.

  2. Do physicians/researchers trade stock based on privileged information? A closer look at trading patterns surrounding the annual ASCO conference.

    PubMed

    Donath, Elie; Eisenberg, Mark J

    2012-01-01

    The goal of this paper was to assess whether, given the opportunity, physicians/researchers would try to profit (by trading stocks) from information that only they were made privy to. The Annual ASCO (American Society of Clinical Oncology) Conference, the largest annual oncology conference, provided the perfect venue to fully explore this question. Up until 2008, ASCO abstracts were released exclusively to ASCO members (i.e., physicians, oncologists) two weeks prior to the conference, and many speculated about unusual trading patterns during these two weeks. In 2008, in response to concerns about such illicit activities, ASCO changed this policy (by distributing these abstracts instead to the general public). We decided to take a closer look at these trading patterns to determine the true impact of ASCO's 2008 decision and whether the differences prior to and following 2008 reveal something about the likelihood of physicians/researchers to profit from "privileged information."

  3. Seasonal and Inter-Annual Patterns of Phytoplankton Community Structure in Monterey Bay, CA Derived from AVIRIS Data During the 2013-2015 HyspIRI Airborne Campaign

    NASA Astrophysics Data System (ADS)

    Palacios, S. L.; Thompson, D. R.; Kudela, R. M.; Negrey, K.; Guild, L. S.; Gao, B. C.; Green, R. O.; Torres-Perez, J. L.

    2015-12-01

    There is a need in the ocean color community to discriminate among phytoplankton groups within the bulk chlorophyll pool to understand ocean biodiversity, to track energy flow through ecosystems, and to identify and monitor for harmful algal blooms. Imaging spectrometer measurements enable use of sophisticated spectroscopic algorithms for applications such as differentiating among coral species, evaluating iron stress of phytoplankton, and discriminating phytoplankton taxa. These advanced algorithms rely on the fine scale, subtle spectral shape of the atmospherically corrected remote sensing reflectance (Rrs) spectrum of the ocean surface. As a consequence, these algorithms are sensitive to inaccuracies in the retrieved Rrs spectrum that may be related to the presence of nearby clouds, inadequate sensor calibration, low sensor signal-to-noise ratio, glint correction, and atmospheric correction. For the HyspIRI Airborne Campaign, flight planning considered optimal weather conditions to avoid flights with significant cloud/fog cover. Although best suited for terrestrial targets, the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) has enough signal for some coastal chlorophyll algorithms and meets sufficient calibration requirements for most channels. However, the coastal marine environment has special atmospheric correction needs due to error that may be introduced by aerosols and terrestrially sourced atmospheric dust and riverine sediment plumes. For this HyspIRI campaign, careful attention has been given to the correction of AVIRIS imagery of the Monterey Bay to optimize ocean Rrs retrievals for use in estimating chlorophyll (OC3 algorithm) and phytoplankton functional type (PHYDOTax algorithm) data products. This new correction method has been applied to several image collection dates during two oceanographic seasons - upwelling and the warm, stratified oceanic period for 2013 and 2014. These two periods are dominated by either diatom blooms (occasionally toxic) or red tides. Results presented include chlorophyll and phytoplankton community structure and in-water validation data for these dates during these two seasons.

  4. Using MODIS Normalized Difference Vegetation Index to monitor seasonal and inter-annual dynamics of wetland vegetation in the Great Artesian Basin: a baseline for assessment of future changes in a unique ecosystem

    NASA Astrophysics Data System (ADS)

    Petus, C.; Lewis, M.; White, D.

    2012-07-01

    The Great Artesian Basin mound springs (Australia) are unique wetland ecosystems of great significance. However, these unique ecosystems are endangered by anthropogenic water extraction. Relationships have been established between the vegetated wetland area and the discharge associated with individual springs, providing a potential means of monitoring groundwater flow using measurements of wetland area. Previous studies using this relationship to monitor Great Artesian Basin springs have used aerial photography or high resolution satellite images, giving sporadic temporal information. These "snapshot " studies need to be placed within a longer and more regular context to better assess changes in response to aquifer draw-downs. In this study, the potential of medium resolution MODIS Normalized Difference Vegetation Index data for studying the long-term and high frequency temporal dynamics of wetland vegetation at the Dalhousie Spring Complex of the GAB is tested. Photosynthetic activity within Dalhousie wetlands could be differentiated from surrounding land responses. The study showed good correlation between wetland vegetated area and groundwater flow, but also the important influence of natural species phenologies, rainfall, and human activity on the observed seasonal and inter-annual vegetation dynamic. Declining trends in the extent of wetland areas were observed over the 2000- 2009 period followed by a return of wetland vegetation since 2010. This study underlined the need to continue long-term medium resolution satellite studies of the Great Artesian Basin as these data provide a good understanding of variability within the wetlands, give temporal context for less frequent studies and a strong baseline for assessment of future changes.

  5. The role of meltwater variability in modulating diurnal to inter-annual ice-sheet flow: New insights from a ~decade of high-temporal resolution GPS observations on the western Greenland margin

    NASA Astrophysics Data System (ADS)

    Stevens, L. A.; Behn, M. D.; Das, S. B.; Joughin, I.; van den Broeke, M.; Herring, T.; McGuire, J. J.

    2015-12-01

    Meltwater-driven processes across the ablation zone of the Greenland Ice Sheet are controlled by seasonal fluxes as well as shorter-term variability in surface melt. Few high-temporal resolution GPS observations of ice-sheet flow extend for longer than a couple years, limiting multiyear analyses of seasonal variability in ice-sheet flow. Using a small GPS network installed at ~1000-m above sea level (m a.s.l.) operating from 2006-2014, and supplemented with a larger array of 20 GPS stations installed from 2011­-2014, we observe nine years of ice-sheet surface motion on the western margin of the Greenland Ice Sheet. The GPS array spans a horizontal distance of 30 km across an elevation range of 700-1250 m a.s.l., and captures the ice-sheet's velocity response to the seasonal melt cycle. By combining the GPS array measurements with temperature, precipitation, and runoff estimates from the Regional Atmospheric Climate Model (RACMO), we examine the relationship between ice-sheet flow and surface melt variability both at the seasonal scale (i.e., during melt onset, summer melt season and melt cessation) as well as during transient high melt periods such as precipitation events, anomalously high melt episodes, and supraglacial lake drainages. We observe varying surface motion following early versus late summer extended melt events, with early-season extended melt events inducing longer sustained speed-up than late summer events. We also examine differences in the timing of melt onset and magnitude, comparing the anomalously high runoff observed across the ice sheet in 2010 and 2012 against the average to low runoff observed in the years comprising the remainder of the record. This nearly decadal record improves our understanding of the role of meltwater variability in modulating ice-sheet flow on diurnal to inter-annual timescales.

  6. Inter-Seasonal and Annual Co-Variation of Smallholder Production Portfolios, Volumes and Incomes with Rainfall and Flood Levels in the Amazon Estuary: Implications for Building Livelihood Resilience to Increasing Variability of Hydro-Climatic Regimes

    NASA Astrophysics Data System (ADS)

    Vogt, N. D.; Fernandes, K.; Pinedo-Vasquez, M.; Brondizio, E. S.; Almeida, O.; Rivero, S.; Rabelo, F. R.; Dou, Y.; Deadman, P.

    2014-12-01

    In this paper we investigate inter-seasonal and annual co-variations of rainfall and flood levels with Caboclo production portfolios, and proportions of it they sell and consume, in the Amazon Estuary from August 2012 to August 2014. Caboclos of the estuary maintain a diverse and flexible land-use portfolio, with a shift in dominant use from agriculture to agroforestry and forestry since WWII (Vogt et al., 2014). The current landscape is configured for acai, shrimp and fish production. In the last decade the frequency of wet seasons with anomalous flood levels and duration has increased primarily from changes in rainfall and discharge from upstream basins. Local rainfall, though with less influence on extreme estuarine flood levels, is reported to be more sporadic and intense in wet season and variable in both wet and dry seasons, for yet unknown reasons. The current production portfolio and its flexibility are felt to build resilience to these increases in hydro-climatic variability and extreme events. What is less understood, for time and costliness of daily measures at household levels, is how variations in flood and rainfall levels affect shifts in the current production portfolio of estuarine Caboclos, and the proportions of it they sell and consume. This is needed to identify what local hydro-climatic thresholds are extreme for current livelihoods, that is, that most adversely affect food security and income levels. It is also needed identify the large-scale forcings driving those extreme conditions to build forecasts for when they will occur. Here we present results of production, rainfall and flood data collected daily in households from both the North and South Channel of the Amazon estuary over last two years to identify how they co-vary, and robustness of current production portfolio under different hydro-climatic conditions.

  7. Inter-annual and Intra-annual Variability in River Flow and Inundation in African River Systems: Results from a new pan-African Land-surface Model Validated against Earth Observations

    NASA Astrophysics Data System (ADS)

    Dadson, S. J.

    2014-12-01

    The role of surface-water flooding in controlling fluxes of water and carbon between the land and the atmosphere is increasingly recognized in studies of the Earth system. Simultaneous advances in remote earth observation and large-scale land-surface and hydrological modeling promise improvements in our ability to understand these linkages, and suggest that improvements in prediction of river flow and inundation extents may result. Here we present an analysis of newly-available observational estimates of surface water inundation obtained through satellite Earth observation with results from simulations produced by using the Joint UK Land Environment Simulator (JULES) land-surface model operating at 0.5 degree resolution over the African continent. The model was forced with meteorological input from the WATCH Forcing Data for the period 1981-2001 and sensitivity to various model configurations and parameter settings were tested. Both the PDM and TOPMODEL sub-grid scale runoff generation schemes were tested for parameter sensitivities, with the evaluation focussing on simulated river discharge in sub-catchments of the Congo, Nile, Niger, Orange, Okavango and Zambezi rivers. It was found that whilst the water balance in each of the catchments can be simulated with acceptable accuracy, the individual responses of each river vary between model configurations so that there is no single runoff parameterization scheme or parameter values that yields optimal results across all catchments. We trace these differences to the model's representation of sub-surface flow and make some suggestions to improve the performance of large-scale land-surface models for use in similar applications. Our findings also demonstrate links between episodes of extensive surface water flooding and large-scale climatic indices, although the pattern of correlations contains a level of spatial and temporal detail that warrants careful attention to the climatology of individual situations. These

  8. Tactile perception of nonpainful unpleasantness in relation to perceived roughness: effects of inter-element spacing and speed of relative motion of rigid 2-D raised-dot patterns at two body loci.

    PubMed

    Kitada, Ryo; Sadato, Norihiro; Lederman, Susan J

    2012-01-01

    Rigid surfaces consisting of spatially jittered 2-D raised-dot patterns with different inter-element spacings were moved back and forth across the skin at three different speeds (10-fold range). Within each psychophysical experiment, participants numerically estimated the perceived magnitude of either unpleasantness (nonpainful) or roughness of 2-D raised-dot surfaces applied to two stationary body sites (experiment 1: fingers; experiment 2: forearm). The psychophysical functions for the two types of perceptual judgment were highly similar at both body loci; more specifically, the perceived magnitude of unpleasantness and roughness both increased monotonically as a power function of increasing inter-element spacing, with the rate of growth declining at the upper end of the continuum. These results suggest that inter-element spacing is a critical determinant of the perceived magnitude of unpleasantness (nonpainful), as well as of roughness. Each perceptual judgment also increased as a function of increasing relative speed at both body loci. However, the magnitude of this effect was significantly greater for perceived unpleasantness than for perceived roughness; conversely, the speed effect was significantly greater on the forearm than on the fingers. Several possible explanations for these findings are considered.

  9. Patterns of Larval Sucker Emigration from the Sprague and Lower Williamson Rivers of the Upper Klamath Basin, Oregon, Prior to the Removal of Chiloquin Dam - 2006 Annual Report

    USGS Publications Warehouse

    Ellsworth, Craig M.; Tyler, Torrey J.; VanderKooi, Scott P.; Markle, Douglas F.

    2009-01-01

    in larval drift at Chiloquin occurred approximately 1.5 to 2.0 hours after sunset. Nightly peak larval drift varied by location; larvae were captured earlier in the evening at sites closer to known spawning locations than sites farther away from these areas. The highest numerical catches of sucker-sized eggs were at Chiloquin indicating that this site is in close proximity to a spawning area. Numerical catches of older, more developed larval and juvenile suckers also were highest at Chiloquin. This may be due to the turbulent nature of this site, which could have swept larger fish into the drift. Proportional catches of older, more developed larval and juvenile suckers were highest at Sycan, Lone Pine, Power Station, and Fremont Bridge. This indicates these sites are located nearer to sucker nursery areas rather than spawning areas. Very few larval LRS were collected at Fremont Bridge at the south end of Upper Klamath Lake. Larval KLS-SNS densities at Fremont Bridge were the third highest of the seven sampling sites. Peak drift of larval KLS-SNS at Fremont Bridge occurred the week after peak drift of larval KLS-SNS at Williamson. Although inter-annual variation continues to appear in the larval drift data, our results continue to show consistent patterns of larval emigration in the drainage basin. In combination with data collected from the spawning movements and destinations of radio-tagged and PIT-tagged adult suckers, this larval drift data will provide a baseline standard by which to determine the effects of dam removal on the spawning distribution of endangered Klamath Basin suckers in the Sprague River.

  10. Effects of simulated daily precipitation patterns on annual plant populations depend on life stage and climatic region

    PubMed Central

    Köchy, Martin

    2008-01-01

    Background To improve the understanding of consequences of climate change for annual plant communities, I used a detailed, grid-based model that simulates the effect of daily rainfall variability on individual plants in five climatic regions on a gradient from 100 to 800 mm mean annual precipitation (MAP). The model explicitly considers moisture storage in the soil. I manipulated daily rainfall variability by changing the daily mean rain (DMR, rain volume on rainy days averaged across years for each day of the year) by ± 20%. At the same time I adjusted intervals appropriately between rainy days for keeping the mean annual volume constant. In factorial combination with changing DMR I also changed MAP by ± 20%. Results Increasing MAP generally increased water availability, establishment, and peak shoot biomass. Increasing DMR increased the time that water was continuously available to plants in the upper 15 to 30 cm of the soil (longest wet period, LWP). The effect of DMR diminished with increasing humidity of the climate. An interaction between water availability and density-dependent germination increased the establishment of seedlings in the arid region, but in the more humid regions the establishment of seedlings decreased with increasing DMR. As plants matured, competition among individuals and their productivity increased, but the size of these effects decreased with the humidity of the regions. Therefore, peak shoot biomass generally increased with increasing DMR but the effect size diminished from the semiarid to the mesic Mediterranean region. Increasing DMR reduced via LWP the annual variability of biomass in the semiarid and dry Mediterranean regions. Conclusion More rainstorms (greater DMR) increased the recharge of soil water reservoirs in more arid sites with consequences for germination, establishment, productivity, and population persistence. The order of magnitudes of DMR and MAP overlapped partially so that their combined effect is important for

  11. INTER-GENERATION OCCUPATIONAL MOBILITY IN BRITAIN,

    DTIC Science & Technology

    The aim in the paper is to bring together, review and, as far as possible, to synthesize the research findings on inter-generation occupational ...empirical studies and other relevant work, the pattern and rates of inter-generation occupational mobility in Britain are described. They are then

  12. Nutrient intake and nutrient patterns and risk of lung cancer among heavy smokers: results from the COSMOS screening study with annual low-dose CT.

    PubMed

    Gnagnarella, Patrizia; Maisonneuve, Patrick; Bellomi, Massimo; Rampinelli, Cristiano; Bertolotti, Raffaella; Spaggiari, Lorenzo; Palli, Domenico; Veronesi, Giulia

    2013-06-01

    The role of nutrients in lung cancer aetiology remains controversial and has never been evaluated in the context of screening. Our aim was to investigate the role of single nutrients and nutrient patterns in the aetiology of lung cancer in heavy smokers. Asymptomatic heavy smokers (≥20 pack-years) were invited to undergo annual low-dose computed tomography. We assessed diet using a self-administered food frequency questionnaire and collected information on multivitamin supplement use. We performed principal component analysis identifying four nutrient patterns and used Cox proportional Hazards regression to assess the association between nutrients and nutrients patterns and lung cancer risk. During a mean follow-up of 5.7 years, 178 of 4,336 participants were diagnosed with lung cancer by screening. We found a significant risk reduction of lung cancer with increasing vegetable fat consumption (HR for highest vs. lowest quartile = 0.50, 95% CI = 0.31-0.80; P-trend = 0.02). Participants classified in the high "vitamins and fiber" pattern score had a significant risk reduction of lung cancer (HR = 0.57; 95% CI = 0.36-0.90, P-trend = 0.01). Among heavy smokers enrolled in a screening trial, high vegetable fat intake and adherence to the "vitamin and fiber" nutrient pattern were associated with reduced lung cancer incidence.

  13. The Rates and Spatial Patterns of Annual Riverbank Erosion Revealed Through Terrestrial Laser Scanner Surveys of the South River, Virginia

    NASA Astrophysics Data System (ADS)

    O'Neal, M. A.; Pizzuto, J. E.

    2011-12-01

    Between 2006 and 2008 A.D., we completed annual surveys of two mercury-contaminated eroding banks, one forested and the other grass covered, along the gravel-bed, bedrock South River in Virginia. Gridded digital terrain models with a resolution of 0.05 m were created from bank topography data collected using a terrestrial laser scanner. The forested bank retreated nearly 1 m around two leaning trees, while elsewhere the extent of bank retreat was negligible. On the grassy bank, retreat was controlled by the creation of small overhanging clumps of turf at the top of the bank, their occasional failure, and the ultimate removal of failed debris from the bank toe. Partial autocorrelation analysis of vertically integrated bank retreat demonstrates that bank profile erosion is virtually uncorrelated at horizontal distances greater than about 1 m on both banks, a length scale of approximately 1/2 the bank height. This extensive streamwise variability suggests that widely spaced profile data cannot adequately represent bank erosion at these sites. Additional analysis of our comprehensive spatial data also indicates that traditional bank profile surveys with any spacing greater than 1 m would result in measurement errors exceeding 10%, an important conclusion for assessing annual rates of mercury loading into the South River from bank erosion. Our results suggest that 3-dimensional gridded bare-earth models of bank topography may be required to accurately measure annual bank retreat in similar river systems.

  14. Application of point-process statistical tools to stable isotopes in xylem water for the study of inter- and intra-specific interactions in water uptake patterns in a mixed stand of Pinus halepensis Mill. and Quercus ilex L.

    NASA Astrophysics Data System (ADS)

    Comas, Carles; del Castillo, Jorge; Voltas, Jordi; Ferrio, Juan Pedro

    2013-04-01

    The stable isotope composition of xylem water reflects has been used to assess inter-specific differences in uptake patterns, revealing synergistic and competition processes in the use of water resources (see e.g. Dawson et al. 1993). However, there is a lack of detailed studies on spatial and temporal variability of inter- and intra-specific competition within forest stands. In this context, the aim of this work was to compare the isotope composition of xylem water (δ18O , δ2H) in two common Mediterranean tree species, Quercus ilex L. and Pinus halepensis Mill, in order to understand their water uptake patterns throughout the growing season. In addition, we analyze the spatial variability of xylem water, to get insight into inter-specific strategies employed to cope with drought and the interaction between the individuals. Our first hypothesis was that both species used different strategies to cope with drought by uptaking water at different depths; and our second hypothesis was that individual trees would behave in different manner according to the distance to their neighbours as well as to whether the neighbour is from one species or the other. The study was performed in a mixed stand where both species are nearly co-dominant, adding up to a total of 33 oaks and 77 pines (plot area= 893 m2). We sampled sun-exposed branches of each tree six times over the growing season, and extracted the xylem water with a cryogenic trap. The isotopic composition of the water was determined using a Picarro Water Analizer L2130-i. Tree mapping for spatial analysis was done using a high resolution GPS technology (Trimble GeoExplorer 6000). For the spatial analysis, we used the pair-correlation function to study intra-specific tree configuration and the bivariate pair correlation function to analyse the inter-specific spatial configurations (Stoyan et al 1995). Moreover, the isotopic composition of xylem water was assumed to be a mark associated to each tree and analysed as a

  15. The influence of watershed characteristics on spatial patterns of trends in annual scale streamflow variability in the continental U.S.

    NASA Astrophysics Data System (ADS)

    Rice, Joshua S.; Emanuel, Ryan E.; Vose, James M.

    2016-09-01

    As human activity and climate variability alter the movement of water through the environment the need to better understand hydrologic cycle responses to these changes has grown. A reasonable starting point for gaining such insight is studying changes in streamflow given the importance of streamflow as a source of renewable freshwater. Using a wavelet assisted method we analyzed trends in the magnitude of annual scale streamflow variability from 967 watersheds in the continental U.S. (CONUS) over a 70 year period (1940-2009). Decreased annual variability was the dominant pattern at the CONUS scale. Ecoregion scale results agreed with the CONUS pattern with the exception of two ecoregions closely divided between increases and decreases and one where increases dominated. A comparison of trends in reference and non-reference watersheds indicated that trend magnitudes in non-reference watersheds were significantly larger than those in reference watersheds. Boosted regression tree (BRT) models were used to study the relationship between watershed characteristics and the magnitude of trends in streamflow. At the CONUS scale, the balance between precipitation and evaporative demand, and measures of geographic location were of high relative importance. Relationships between the magnitude of trends and watershed characteristics at the ecoregion scale exhibited differences from the CONUS results and substantial variability was observed among ecoregions. Additionally, the methodology used here has the potential to serve as a robust framework for top-down, data driven analyses of the relationships between changes in the hydrologic cycle and the spatial context within which those changes occur.

  16. Foundations for a syntatic pattern recognition system for genomic DNA sequences. [Annual] report, 1 December 1991--31 March 1993

    SciTech Connect

    Searles, D.B.

    1993-03-01

    The goal of the proposed work is the creation of a software system that will perform sophisticated pattern recognition and related functions at a level of abstraction and with expressive power beyond current general-purpose pattern-matching systems for biological sequences; and with a more uniform language, environment, and graphical user interface, and with greater flexibility, extensibility, embeddability, and ability to incorporate other algorithms, than current special-purpose analytic software.

  17. Inferring the annual migration patterns of fall armyworm (Lepidoptera: Noctuidae) in the United States from mitochondrial haplotypes

    PubMed Central

    Nagoshi, Rodney N; Meagher, Robert L; Hay-Roe, Mirian

    2012-01-01

    Spodoptera frugiperda (J. E. Smith) or fall armyworm is an important agricultural pest of a number of crops in the western hemisphere. In the United States, infestations in corn acreages extend from the Mexican to the Canadian border. Because fall armyworm does not survive prolonged freezing, the infestations annually affecting most of North America are migrants from southern Texas and Florida, where winter temperatures are mild and host plants are available. A haplotype method was developed that can distinguish between these two geographically distant overwintering populations, with the potential to delineate the associated migratory pathways. Several years of collections from major corn-producing areas in the southern, central, and eastern United States were used to map the geographical distribution of the fall armyworm haplotypes. From these haplotype profiles, it was possible to develop the most detailed description yet of the annual northward movements of fall armyworm. The consistency of these results with past studies and the implications on our understanding of fall armyworm biology are discussed. A better understanding of fall armyworm populations and their movement is critical for the development of strategies to predict infestation levels and eventually control this pest in the United States. PMID:22957154

  18. Inter- and intraannual growth patterns of urban small-leaved lime (Tilia cordata mill.) at two public squares with contrasting microclimatic conditions

    NASA Astrophysics Data System (ADS)

    Moser, Astrid; Rahman, Mohammad A.; Pretzsch, Hans; Pauleit, Stephan; Rötzer, Thomas

    2016-12-01

    The effects of urban conditions on tree growth have been investigated in an increasing number of studies over the last decades, emphasizing the harsh environment of cities. Urban trees often grow in highly paved, compacted sites with consequently less soil moisture, higher soil temperatures, and greater vapor pressure deficits. However, there is still a knowledge gap regarding the impact of harsh paved environments on urban tree growth during drought years on the growth patterns of urban trees. The present study investigated the structure and growth of the common urban tree species small-leaved lime (Tilia cordata) at a highly paved public square (CPS) compared with a contrasting more open, greener square (OGS). Continuously, measured high precision dendrometer data along with meteorological data of the extreme dry and warm summer 2015 as well as dendrochronological data of the sampled trees were investigated to analyze tree growth during a drought year. The results highlight different tree dimensions and growth patterns of the trees at both sites, influenced by tree age and distinct site conditions. While the trees at OGS grew up to 2.5 mm from July until mid of August, the trees at CPS had only 0.4-mm diameter increment. After the initial expansion at CPS, tree diameter contracted again during summer to the point of shrinkage (up to 0.8 mm) at the end of our investigation. Further drought year analysis confirmed the patterns of significant stem growth reductions in the consecutive two years following the drought. A correlation analysis revealed that transpiration, air temperature, and vapor pressure deficit were negatively correlated with the daily diameter growth, whereas precipitation had a strong positive effect. Due to high transpiration rates associated with anisohydric water use behavior, T. cordata was able to provide evaporative cooling even during drought. However, this anisohydric behavior resulted in substantial growth decline afterwards especially at

  19. Inter- and intraannual growth patterns of urban small-leaved lime (Tilia cordata mill.) at two public squares with contrasting microclimatic conditions.

    PubMed

    Moser, Astrid; Rahman, Mohammad A; Pretzsch, Hans; Pauleit, Stephan; Rötzer, Thomas

    2016-12-16

    The effects of urban conditions on tree growth have been investigated in an increasing number of studies over the last decades, emphasizing the harsh environment of cities. Urban trees often grow in highly paved, compacted sites with consequently less soil moisture, higher soil temperatures, and greater vapor pressure deficits. However, there is still a knowledge gap regarding the impact of harsh paved environments on urban tree growth during drought years on the growth patterns of urban trees. The present study investigated the structure and growth of the common urban tree species small-leaved lime (Tilia cordata) at a highly paved public square (CPS) compared with a contrasting more open, greener square (OGS). Continuously, measured high precision dendrometer data along with meteorological data of the extreme dry and warm summer 2015 as well as dendrochronological data of the sampled trees were investigated to analyze tree growth during a drought year. The results highlight different tree dimensions and growth patterns of the trees at both sites, influenced by tree age and distinct site conditions. While the trees at OGS grew up to 2.5 mm from July until mid of August, the trees at CPS had only 0.4-mm diameter increment. After the initial expansion at CPS, tree diameter contracted again during summer to the point of shrinkage (up to 0.8 mm) at the end of our investigation. Further drought year analysis confirmed the patterns of significant stem growth reductions in the consecutive two years following the drought. A correlation analysis revealed that transpiration, air temperature, and vapor pressure deficit were negatively correlated with the daily diameter growth, whereas precipitation had a strong positive effect. Due to high transpiration rates associated with anisohydric water use behavior, T. cordata was able to provide evaporative cooling even during drought. However, this anisohydric behavior resulted in substantial growth decline afterwards especially

  20. The Late Pleistocene-Holocene community development in Central and SE-Europe in direct fossil record: scope of the approach, common patterns and inter-regional differences.

    NASA Astrophysics Data System (ADS)

    Horacek, Ivan; Lozek, Vojen

    2010-05-01

    The information provided by modern instrumental approaches (molecular phylogeography, ancient DNA analyses, large scale radiocarbon datings etc.) refined the knowledge on Late Quaternary faunal development and range history of particular taxa in essential way. Nevertheless, the direct fossil record remains still an essential substrate in study of that topics, and to reveal all the information, that it may provide, and integrate it with the outputs of the other approaches presents one of the essential aim of the present meeting. Unfortunately, the immediate use of fossil record for the paleoecologic and paleobiogeographic inferences is often limited by its fragmentarity (both in temporal and spatial respects), taphonomic influences and/or locally specific post-sedimentary effects which all may bias it in a considerable degree. Hence, each particular record is to be carefully reexamined in respect to all factor which may bias it - unfortunately, often it is not too easy to respond that task, particularly when the record is retrived from secondary sources. It should also be remembered that the records representing narrow time slices without a robust lithostratigraphic context do not provide any information on the historical and contextual setting of the respective faunal situation. Such information that is essential for reconstructions of paleobiogeography of community development and similar locally-sensitive phenomena can only be retrived from the continuous sedimentary series which establish the sequence of particular faunal events by direct superposition. A sufficiently dense network of such series provides than a possibility of direct inter-regional comparisons and a high resolution information on the paleobiogeography of the Late Pleistocene-Holocene rearrangements of mammalian communities, local variation in history of particular species and its community context. We illustrate productivity of such approach on with aid of the fossil record obtained from

  1. Regional climate pattern during two millennia estimated from annual tree rings of Yaku cedar trees: a hint for solar variability?

    NASA Astrophysics Data System (ADS)

    Muraki, Yasushi; Mitsutani, Takumi; Shibata, Shoichi; Kuramata, Syuichi; Masuda, Kimiaki; Nagaya, Kentaro

    2015-02-01

    We analyzed trees that have survived on Yaku island (Yakushima) for 2,000 years. Quite surprisingly, the Fourier and wavelet analyses of the annual growth rate identified 2 cycles of periodicities of 11 and (24 ± 4) years during the Oort, Wolf, Spörer, Maunder, and Dalton minima. The 11-year periodicity originated from solar activity, while the (24 ± 4)-year periodicity may be related to the Pacific Decadal Oscillation (PDO). In particular, we have discovered an 11-year periodicity in the meteorological daylight-hour data from Yakushima in the month of June during 1938 to 2013 and a 24-year periodicity in July. The growth rate of the tree rings may be affected by the variation of the daylight hour.

  2. Broad-scale sampling of primary freshwater fish populations reveals the role of intrinsic traits, inter-basin connectivity, drainage area and latitude on shaping contemporary patterns of genetic diversity.

    PubMed

    Sousa-Santos, Carla; Robalo, Joana I; Pereira, Ana M; Branco, Paulo; Santos, José Maria; Ferreira, Maria Teresa; Sousa, Mónica; Doadrio, Ignacio

    2016-01-01

    Background. Worldwide predictions suggest that up to 75% of the freshwater fish species occurring in rivers with reduced discharge could be extinct by 2070 due to the combined effect of climate change and water abstraction. The Mediterranean region is considered to be a hotspot of freshwater fish diversity but also one of the regions where the effects of climate change will be more severe. Iberian cyprinids are currently highly endangered, with over 68% of the species raising some level of conservation concern. Methods. During the FISHATLAS project, the Portuguese hydrographical network was extensively covered (all the 34 river basins and 47 sub-basins) in order to contribute with valuable data on the genetic diversity distribution patterns of native cyprinid species. A total of 188 populations belonging to 16 cyprinid species of Squalius, Luciobarbus, Achondrostoma, Iberochondrostoma, Anaecypris and Pseudochondrostoma were characterized, for a total of 3,678 cytochrome b gene sequences. Results. When the genetic diversity of these populations was mapped, it highlighted differences among populations from the same species and between species with identical distribution areas. Factors shaping the contemporary patterns of genetic diversity were explored and the results revealed the role of latitude, inter-basin connectivity, migratory behaviour, species maximum size, species range and other species intrinsic traits in determining the genetic diversity of sampled populations. Contrastingly, drainage area and hydrological regime (permanent vs. temporary) seem to have no significant effect on genetic diversity. Species intrinsic traits, maximum size attained, inter-basin connectivity and latitude explained over 30% of the haplotype diversity variance and, generally, the levels of diversity were significantly higher for smaller sized species, from connected and southerly river basins. Discussion. Targeting multiple co-distributed species of primary freshwater fish allowed

  3. Broad-scale sampling of primary freshwater fish populations reveals the role of intrinsic traits, inter-basin connectivity, drainage area and latitude on shaping contemporary patterns of genetic diversity

    PubMed Central

    Robalo, Joana I.; Pereira, Ana M.; Branco, Paulo; Santos, José Maria; Ferreira, Maria Teresa; Sousa, Mónica; Doadrio, Ignacio

    2016-01-01

    Background. Worldwide predictions suggest that up to 75% of the freshwater fish species occurring in rivers with reduced discharge could be extinct by 2070 due to the combined effect of climate change and water abstraction. The Mediterranean region is considered to be a hotspot of freshwater fish diversity but also one of the regions where the effects of climate change will be more severe. Iberian cyprinids are currently highly endangered, with over 68% of the species raising some level of conservation concern. Methods. During the FISHATLAS project, the Portuguese hydrographical network was extensively covered (all the 34 river basins and 47 sub-basins) in order to contribute with valuable data on the genetic diversity distribution patterns of native cyprinid species. A total of 188 populations belonging to 16 cyprinid species of Squalius, Luciobarbus, Achondrostoma, Iberochondrostoma, Anaecypris and Pseudochondrostoma were characterized, for a total of 3,678 cytochrome b gene sequences. Results. When the genetic diversity of these populations was mapped, it highlighted differences among populations from the same species and between species with identical distribution areas. Factors shaping the contemporary patterns of genetic diversity were explored and the results revealed the role of latitude, inter-basin connectivity, migratory behaviour, species maximum size, species range and other species intrinsic traits in determining the genetic diversity of sampled populations. Contrastingly, drainage area and hydrological regime (permanent vs. temporary) seem to have no significant effect on genetic diversity. Species intrinsic traits, maximum size attained, inter-basin connectivity and latitude explained over 30% of the haplotype diversity variance and, generally, the levels of diversity were significantly higher for smaller sized species, from connected and southerly river basins. Discussion. Targeting multiple co-distributed species of primary freshwater fish allowed

  4. Remapping annual precipitation in mountainous areas based on vegetation patterns: a case study in the Nu River basin

    NASA Astrophysics Data System (ADS)

    Zhou, Xing; Ni, Guang-Heng; Shen, Chen; Sun, Ting

    2017-02-01

    Accurate high-resolution estimates of precipitation are vital to improving the understanding of basin-scale hydrology in mountainous areas. The traditional interpolation methods or satellite-based remote sensing products are known to have limitations in capturing the spatial variability of precipitation in mountainous areas. In this study, we develop a fusion framework to improve the annual precipitation estimation in mountainous areas by jointly utilizing the satellite-based precipitation, gauge measured precipitation, and vegetation index. The development consists of vegetation data merging, vegetation response establishment, and precipitation remapping. The framework is then applied to the mountainous areas of the Nu River basin for precipitation estimation. The results demonstrate the reliability of the framework in reproducing the high-resolution precipitation regime and capturing its high spatial variability in the Nu River basin. In addition, the framework can significantly reduce the errors in precipitation estimates as compared with the inverse distance weighted (IDW) method and the TRMM (Tropical Rainfall Measuring Mission) precipitation product.

  5. Patterns of floodplain sediment deposition along the regulated lower Roanoke River, North Carolina: annual, decadal, centennial scales

    USGS Publications Warehouse

    Hupp, Cliff R.; Schenk, Edward R.; Kroes, Daniel; Willard, Debra A.; Townsend, Phil A.; Peet, Robert K.

    2015-01-01

    The lower Roanoke River on the Coastal Plain of North Carolina is not embayed and maintains a floodplain that is among the largest on the mid-Atlantic Coast. This floodplain has been impacted by substantial aggradation in response to upstream colonial and post-colonial agriculture between the mid-eighteenth and mid-nineteenth centuries. Additionally, since the mid-twentieth century stream flow has been regulated by a series of high dams. We used artificial markers (clay pads), tree-ring (dendrogeomorphic) techniques, and pollen analyses to document sedimentation rates/amounts over short-, intermediate-, and long-term temporal scales, respectively. These analyses occurred along 58 transects at 378 stations throughout the lower river floodplain from near the Fall Line to the Albemarle Sound. Present sediment deposition rates ranged from 0.5 to 3.4 mm/y and 0.3 to 5.9 mm/y from clay pad and dendrogeomorphic analyses, respectively. Deposition rates systematically increased from upstream (high banks and floodplain) to downstream (low banks) reaches, except the lowest reaches. Conversely, legacy sediment deposition (A.D. 1725 to 1850) ranged from 5 to about 40 mm/y, downstream to upstream, respectively, and is apparently responsible for high banks upstream and large/wide levees along some of the middle stream reaches. Dam operations have selectively reduced levee deposition while facilitating continued backswamp deposition. A GIS-based model predicts 453,000 Mg of sediment is trapped annually on the floodplain and that little watershed-derived sediment reaches the Albemarle Sound. Nearly all sediment in transport and deposited is derived from the channel bed and banks. Legacy deposits (sources) and regulated discharges affect most aspects of present fluvial sedimentation dynamics. The lower river reflects complex relaxation conditions following both major human alterations, yet continues to provide the ecosystem service of sediment trapping.

  6. Patterns of floodplain sediment deposition along the regulated lower Roanoke River, North Carolina: Annual, decadal, centennial scales

    NASA Astrophysics Data System (ADS)

    Hupp, C. R.; Schenk, E. R.; Kroes, D. E.; Willard, D. A.; Townsend, P. A.; Peet, R. K.

    2015-01-01

    The lower Roanoke River on the Coastal Plain of North Carolina is not embayed and maintains a floodplain that is among the largest on the mid-Atlantic Coast. This floodplain has been impacted by substantial aggradation in response to upstream colonial and post-colonial agriculture between the mid-eighteenth and mid-nineteenth centuries. Additionally, since the mid-twentieth century stream flow has been regulated by a series of high dams. We used artificial markers (clay pads), tree-ring (dendrogeomorphic) techniques, and pollen analyses to document sedimentation rates/amounts over short-, intermediate-, and long-term temporal scales, respectively. These analyses occurred along 58 transects at 378 stations throughout the lower river floodplain from near the Fall Line to the Albemarle Sound. Present sediment deposition rates ranged from 0.5 to 3.4 mm/y and 0.3 to 5.9 mm/y from clay pad and dendrogeomorphic analyses, respectively. Deposition rates systematically increased from upstream (high banks and floodplain) to downstream (low banks) reaches, except the lowest reaches. Conversely, legacy sediment deposition (A.D. 1725 to 1850) ranged from 5 to about 40 mm/y, downstream to upstream, respectively, and is apparently responsible for high banks upstream and large/wide levees along some of the middle stream reaches. Dam operations have selectively reduced levee deposition while facilitating continued backswamp deposition. A GIS-based model predicts 453,000 Mg of sediment is trapped annually on the floodplain and that little watershed-derived sediment reaches the Albemarle Sound. Nearly all sediment in transport and deposited is derived from the channel bed and banks. Legacy deposits (sources) and regulated discharges affect most aspects of present fluvial sedimentation dynamics. The lower river reflects complex relaxation conditions following both major human alterations, yet continues to provide the ecosystem service of sediment trapping.

  7. Annual trend patterns of phytoplankton species abundance belie homogeneous taxonomical group responses to climate in the NE Atlantic upwelling.

    PubMed

    Bode, Antonio; Estévez, M Graciela; Varela, Manuel; Vilar, José A

    2015-09-01

    Phytoplankton is a sentinel of marine ecosystem change. Composed by many species with different life-history strategies, it rapidly responds to environment changes. An analysis of the abundance of 54 phytoplankton species in Galicia (NW Spain) between 1989 and 2008 to determine the main components of temporal variability in relation to climate and upwelling showed that most of this variability was stochastic, as seasonality and long term trends contributed to relatively small fractions of the series. In general, trends appeared as non linear, and species clustered in 4 groups according to the trend pattern but there was no defined pattern for diatoms, dinoflagellates or other groups. While, in general, total abundance increased, no clear trend was found for 23 species, 14 species decreased, 4 species increased during the early 1990s, and only 13 species showed a general increase through the series. In contrast, series of local environmental conditions (temperature, stratification, nutrients) and climate-related variables (atmospheric pressure indices, upwelling winds) showed a high fraction of their variability in deterministic seasonality and trends. As a result, each species responded independently to environmental and climate variability, measured by generalized additive models. Most species showed a positive relationship with nutrient concentrations but only a few showed a direct relationship with stratification and upwelling. Climate variables had only measurable effects on some species but no common response emerged. Because its adaptation to frequent disturbances, phytoplankton communities in upwelling ecosystems appear less sensitive to changes in regional climate than other communities characterized by short and well defined productive periods.

  8. A Year in the Life: Annual Patterns of CO2 and CH4 from a Northern Finland Peatland, Including Anaerobic Methane Oxidation and Summer Ebullition Rates

    NASA Astrophysics Data System (ADS)

    Miller, K.; Lipson, D.; Biasi, C.; Dorodnikov, M.; Männistö, M.; Lai, C. T.

    2014-12-01

    The major ecological controls on methane (CH4) and carbon dioxide (CO2) fluxes in northern wetland systems are well known, yet estimates of source/sink magnitudes are often incongruous with measured rates. This mismatch persists because holistic flux datasets are rare, preventing 'whole picture' determinations of flux controls. To combat this, we measured net CO2 and CH4 fluxes from September 2012-2013 within a peatland in northern Lapland, Finland. In addition, we performed in situ manipulations and in vitro soil incubations to quantify anaerobic methane oxidation and methanogenic rates as they related to alternative electron acceptor availability. Average annual fluxes varied substantially between different depressions within the wetland, a pattern that persisted through all seasons. Season was a strong predictor of both CO2 and CH4 flux rates, yet CH4 rates were not related to melt-season 10cm or 30cm soil temperatures, and only poorly predicted with air temperatures. We found evidence for both autumnal and spring thaw CH4 bursts, collectively accounting for 26% of annual CH4 flux, although the autumnal burst was more than 5 fold larger than the spring burst. CH4 ebullition measured throughout the growing season augmented the CH4 source load by a factor of 1.5, and was linked with fine-scale spatial heterogeneity within the wetland. Surprisingly, CH4 flux rates were insensitive to Fe(III) and humic acid soil amendments, both of which amplified CO2 fluxes. Using in vitro incubations, we determined anaerobic methane oxidation and methanogenesis rates. Measured anaerobic oxidation rates showed potential consumption of between 6-39% of the methane produced, contributing approximately 1% of total carbon dioxide flux. Treatments of nitrate, sulfate and ferric iron showed that nitrate suppressed methanogenesis, but were not associated with anaerobic oxidation rates.

  9. Responses of the Bering-Chukchi Shelf Circulation at Synoptic and Inter-Annual Time Scales to the Location, Strength, and Direction of North Pacific and Western Arctic Winds

    NASA Astrophysics Data System (ADS)

    Danielson, S. L.; Weingartner, T.; Hedstrom, K.; Aagaard, K.; Woodgate, R. A.; Curchitser, E. N.; Stabeno, P. J.

    2014-12-01

    We develop a conceptual model of the closely co-dependent Bering shelf, Bering Strait, and Chukchi shelf circulation fields by evaluating the effects of wind stress over the North Pacific and western Arctic. This conceptual model suggests Bering Strait transport anomalies are primarily set by the longitudinal location of the Aleutian Low, which drives oppositely signed anomalies at synoptic and annual time scales. Synoptic time scale variations in shelf currents result from local wind forcing and remotely generated continental shelf waves, whereas annual variations are driven by basin scale adjustments to wind stress that alter the magnitude of the along-strait (meridional) pressure gradient. In particular, we show that storms centered over the Bering Sea excite continental shelf waves on the eastern Bering shelf that carry northward velocity anomalies northward through Bering Strait and along the Chukchi coast. The integrated effect of these storms tends to decrease the northward Bering Strait transport at annual to decadal time scales by imposing cyclonic wind stress curl over the Aleutian Basin and the Western Subarctic Gyre. Ekman suction then increases the water column density through isopycnal uplift, thereby decreasing the dynamic height, sea surface height, and along-strait pressure gradient. Storms displaced eastward over the Gulf of Alaska generate an opposite set of Bering shelf and Aleutian Basin responses. While Ekman pumping controls Canada Basin dynamic heights [Proshutinsky et al., 2002], we do not find evidence for a strong relation between Beaufort Gyre sea surface height variations and the annually averaged Bering Strait throughflow. Over the western Chukchi and East Siberian seas easterly winds promote coastal divergence, which also increases the along-strait pressure head, as well as generates shelf waves that impinge upon Bering Strait from the northwest.

  10. Climate change impact on the annual water balance in the northwest Florida coastal

    NASA Astrophysics Data System (ADS)

    Alizad, K.; Wang, D.; Alimohammadi, N.; Hagen, S. C.

    2012-12-01

    As the largest tributary to the Apalachicola River, the Chipola River originates in southern Alabama, flows through Florida Panhandle and ended to Gulf of Mexico. The Chipola watershed is located in an intermediate climate environment with aridity index around one. Watershed provides habitat for a number of threatened and endangered animal and plant species. However, climate change affects hydrologic cycle of Chipola River watershed at various temporal and spatial scales. Studying the effects of climate variations is of great importance for water and environmental management purposes in this catchment. This research is mainly focuses on assessing climate change impact on the partitioning pattern of rainfall from mean annual to inter-annual and to seasonal scales. At the mean annual scale, rainfall is partitioned into runoff and evaporation assuming negligible water storage changes. Mean annual runoff is controlled by both mean annual precipitation and potential evaporation. Changes in long term mean runoff caused by variations of long term mean precipitation and potential evaporation will be evaluated based on Budyko hypothesis. At the annual scale, rainfall is partitioned into runoff, evaporation, and storage change. Inter-annual variability of runoff and evaporation are mainly affected by the changes of mean annual climate variables as well as their inter-annual variability. In order to model and evaluate each component of water balance at the annual scale, parsimonious but reliable models, are developed. Budyko hypothesis on the existing balance between available water and energy supply is reconsidered and redefined for the sub-annual time scale and reconstructed accordingly in order to accurately model seasonal hydrologic balance of the catchment. Models are built in the seasonal time frame with a focus on the role of storage change in water cycle. Then for Chipola catchment, models are parameterized based on a sufficient time span of historical data and the

  11. Invasion of a semi-arid shrubland by annual grasses increases autotrophic and heterotrophic soil respiration rates due to altered soil moisture and temperature patterns

    NASA Astrophysics Data System (ADS)

    Mauritz, M.; Hale, I.; Lipson, D.

    2010-12-01

    Shrub <-> grassland conversions are a globally occurring phenomenon altering habitat structure, quality and nutrient cycling. Grasses and shrubs differ in their above and belowground biomass allocation, root architecture, phenology, litter quality and quantity. Conversion affects soil microbial communities, soil moisture and temperature and carbon (C) allocation patterns. However, the effect of conversion on C storage is regionally variable and there is no consistent direction of change. In Southern California invasion by annual grasses is a major threat to native shrub communities and it has been proposed that grass invasion increases NPP and ecosystem C storage (Wolkovich et al, 2009). In order to better understand how this shrub <-> grassland conversion changes ecosystem C storage it is important to understand the partitioning of soil respiration into autotrophic and heterotrophic components. Respiration was measured in plots under shrubs and grasses from February when it was cold and wet to July when it was hot and dry, capturing seasonal transitions in temperature and water availability. Roots were excluded under shrubs and grasses with root exclusion cores to quantify heterotrophic respiration. Using total soil respiration (Rt) = autotrophic respiration (root) (Ra)+ heterotrophic respiration (microbial) (Rh) the components contributing to total soil respiration can be evaluated. Respiration, soil moisture and temperature were measured daily at four hour intervals using Licor 8100 automated chamber measurements. Throughout the measurement period, Rt under grasses exceeded Rt under shrubs. Higher Rt levels under grasses were mainly due to higher Ra in grasses rather than changes in Rh. On average grass Ra was almost double shrub Ra. Higher grass respiration levels are partially explained by differences in soil moisture and temperature between shrubs and grasses. Respiration rates responded similarly to seasonal transitions regardless of treatment although Ra

  12. Inter-comparison of hydro-climatic regimes across northern catchments: Synchronicity, resistance and resilience

    USGS Publications Warehouse

    Carey, S.K.; Tetzlaff, D.; Seibert, J.; Soulsby, C.; Buttle, J.; Laudon, H.; McDonnell, J.; McGuire, K.; Caissie, D.; Shanley, J.; Kennedy, M.; Devito, K.; Pomeroy, J.W.

    2010-01-01

    The higher mid-latitudes of the Northern Hemisphere are particularly sensitive to climate change as small differences in temperature determine frozen ground status, precipitation phase, and the magnitude and timing of snow accumulation and melt. An international inter-catchment comparison program, North-Watch, seeks to improve our understanding of the sensitivity of northern catchments to climate change by examining their hydrological and biogeochemical responses. The catchments are located in Sweden (Krycklan), Scotland (Mharcaidh, Girnock and Strontian), the United States (Sleepers River, Hubbard Brook and HJ Andrews) and Canada (Catamaran, Dorset and Wolf Creek). This briefing presents the initial stage of the North-Watch program, which focuses on how these catchments collect, store and release water and identify 'types' of hydro-climatic catchment response. At most sites, a 10-year data of daily precipitation, discharge and temperature were compiled and evaporation and storage were calculated. Inter-annual and seasonal patterns of hydrological processes were assessed via normalized fluxes and standard flow metrics. At the annual-scale, relations between temperature, precipitation and discharge were compared, highlighting the role of seasonality, wetness and snow/frozen ground. The seasonal pattern and synchronicity of fluxes at the monthly scale provided insight into system memory and the role of storage. We identified types of catchments that rapidly translate precipitation into runoff and others that more readily store water for delayed release. Synchronicity and variance of rainfall-runoff patterns were characterized by the coefficient of variation (cv) of monthly fluxes and correlation coefficients. Principal component analysis (PCA) revealed clustering among like catchments in terms of functioning, largely controlled by two components that (i) reflect temperature and precipitation gradients and the correlation of monthly precipitation and discharge and (ii

  13. Fungiform papilla pattern: EGF regulates inter-papilla lingual epithelium and decreases papilla number by means of PI3K/Akt, MEK/ERK, and p38 MAPK signaling.

    PubMed

    Liu, Hong-Xiang; Henson, Bradley S; Zhou, Yanqiu; D'Silva, Nisha J; Mistretta, Charlotte M

    2008-09-01

    Fungiform papillae are epithelial taste organs that form on the tongue, requiring differentiation of papillae and inter-papilla epithelium. We tested roles of epidermal growth factor (EGF) and the receptor EGFR in papilla development. Developmentally, EGF was localized within and between papillae whereas EGFR was progressively restricted to inter-papilla epithelium. In tongue cultures, EGF decreased papillae and increased cell proliferation in inter-papilla epithelium in a concentration-dependent manner, whereas EGFR inhibitor increased and fused papillae. EGF preincubation could over-ride disruption of Shh signaling that ordinarily would effect a doubling of fungiform papillae. With EGF-induced activation of EGFR, we demonstrated phosphorylation in PI3K/Akt, MEK/ERK, and p38 MAPK pathways; with pathway inhibitors (LY294002, U0126, SB203580) the EGF-mediated decrease in papillae was reversed, and synergistic actions were shown. Thus, EGF/EGFR signaling by means of PI3K/Akt, MEK/ERK, and p38 MAPK contributes to epithelial cell proliferation between papillae; this biases against papilla differentiation and reduces numbers of papillae.

  14. Ranking inter-relationships between clusters

    NASA Astrophysics Data System (ADS)

    Wang, Tingting; Chen, Feng; Phoebe Chen, Yi-Ping

    2011-12-01

    The evaluation of the relationships between clusters is important to identify vital unknown information in many real-life applications, such as in the fields of crime detection, evolution trees, metallurgical industry and biology engraftment. This article proposes a method called 'mode pattern + mutual information' to rank the inter-relationship between clusters. The idea of the mode pattern is used to find outstanding objects from each cluster, and the mutual information criterion measures the close proximity of a pair of clusters. Our approach is different from the conventional algorithms of classifying and clustering, because our focus is not to classify objects into different clusters, but instead, we aim to rank the inter-relationship between clusters when the clusters are given. We conducted experiments on a wide range of real-life datasets, including image data and cancer diagnosis data. The experimental results show that our algorithm is effective and promising.

  15. Longitudinal Inter-Comparison of Modeled and Measured West Greenland Ice Sheet Meltwater Runoff Losses (2004-2014)

    NASA Astrophysics Data System (ADS)

    Moustafa, S.; Rennermalm, A. K.; Tedesco, M.; Mote, T. L.; Koenig, L.; Smith, L. C.; Hagedorn, B.; Overeem, I.; Sletten, R. S.; Mikkelsen, A. B.; Hasholt, B.; Hall, D. K.

    2015-12-01

    Increased surface meltwater runoff, that exits the Greenland ice sheet (GrIS) margin via supra-, en-, and sub-glacial drainage networks into fjords, pro-glacial lakes and rivers, accounts for half or more of total mass loss. Despite its importance, modeled meltwater runoff fluxes are poorly constrained, primarily due to a lack of direct in situ observations. Here, we present the first ever longitudinal (north-south) inter-comparison of a multi-year dataset (2004-2014) of discharge for four drainage basins - Watson, Akuliarusiarsuup Kuua, Naujat Kuat, and North Rivers - along West Greenland. These in situ hydrologic measurements are compared with modeled runoff output from Modèle Atmosphérique Régional (MAR) regional climate model, and the performance of the model is examined. An analysis of the relationship between modeled and actual ice sheet runoff patterns is assessed, and provides insight into the model's ability to capture inter-annual and intra-annual variability, spatiotemporal patterns, and extreme melt events. This study's findings will inform future development and parameterization of ice sheet surface mass balance models.

  16. Ultrasound Annual, 1984

    SciTech Connect

    Sanders, R.C.; Hill, M.C.

    1984-01-01

    The 1984 edition of Ultrasound Annual explores new applications of ultrasound in speech and swallowing and offers guidelines on the use of ultrasound and nuclear medicine in thyroid and biliary tract disease. Other areas covered include Doppler sonography of the abdomen, intraoperative abdominal ultrasound, sonography of the placenta, ultrasound of the neonatal head and abdomen, and sonographic echo patterns created by fat.

  17. Solar induced inter-annual variability of ozone

    NASA Astrophysics Data System (ADS)

    Fytterer, Tilo; Nieder, Holger; Perot, Kristell; Sinnhuber, Miriam; Stiller, Gabriele; Urban, Joachim

    2014-05-01

    Measurements by the Michelson Interferometer for Passive Atmospheric Sounding instrument on board the ENVIromental SATellite from 2005 - 2011 are used to investigate the impact of solar and geomagnetic activity on O3 in the stratosphere and mesosphere inside the Antarctic polar vortex. It is known from observations that energetic particles, mainly originating from the sun, precipitate in the Earth atmosphere and produce odd nitrogen NOx (N + NO + NO2) in the upper mesosphere and lower thermosphere, which is transported downwards into the stratosphere during polar winter. Results from global chemistry-transport models suggest that this leads to a depletion of O3 down to ~30 km at high latitudes during winter. Therefore it appears promising to search for a link between high energetic particles and O3 in actual data sets. Thus in this study, correlation analysis between a 26 days average centred around 1 Apr, 1 May and 1 Jun of several solar/geomagnetic indices (Ap index, F10.7 cm solar radio flux, Lyman-alpha, 2 MeV electrons flux) and 26 day running means from 1 Apr - 1 Nov of O3 in the altitude range from 20 - 70 km were performed. The results reveal negative correlation coefficients propagating downwards throughout the polar winter, at least for the Ap index and the 2 MeV electrons flux. Comparisons with TIMED/SABER and Odin/SMR O3 data are in moderate agreement, also showing a descending negative signal in either indices, but only for the correlation with 1 Apr.

  18. Real-time PCR for detection of Strongyloides stercoralis in human stool samples from Côte d'Ivoire: diagnostic accuracy, inter-laboratory comparison and patterns of hookworm co-infection.

    PubMed

    Becker, Sören L; Piraisoody, Nivetha; Kramme, Stefanie; Marti, Hanspeter; Silué, Kigbafori D; Panning, Marcus; Nickel, Beatrice; Kern, Winfried V; Herrmann, Mathias; Hatz, Christoph F; N'Goran, Eliézer K; Utzinger, Jürg; von Müller, Lutz

    2015-10-01

    Human infections with the helminth species Strongyloides stercoralis encompass a wide clinical spectrum, ranging from asymptomatic carriage to life-threatening disease. The diagnosis of S. stercoralis is cumbersome and the sensitivity of conventional stool microscopy is low. New molecular tools have been developed to increase sensitivity. We compared the diagnostic accuracy of real-time PCR with microscopy for the detection of S. stercoralis and hookworm in human stool samples, and investigated the inter-laboratory agreement of S. stercoralis-specific real-time PCR in two European laboratories. Stool specimens from 256 randomly selected individuals in rural Côte d'Ivoire were examined using three microscopic techniques (i.e. Kato-Katz, Koga agar plate (KAP) and Baermann (BM)). Additionally, ethanol-fixed stool aliquots were subjected to molecular diagnosis. The prevalence of S. stercoralis and hookworm infection was 21.9% and 52.0%, respectively, whilst co-infections were detected in 35 (13.7%) participants. The diagnostic agreement between real-time PCR and microscopy was excellent when both KAP and BM tested positive for S. stercoralis, but was considerably lower when only one microscopic technique was positive. The sensitivity of KAP, BM and real-time PCR for detection of S. stercoralis as compared to a combination of all diagnostic techniques was 21.4%, 37.5% and 76.8%, respectively. The inter-laboratory agreement of S. stercoralis-specific PCR was substantial (κ=0.63, p<0.001). We conclude that a combination of real-time PCR and stool microscopy shows high accuracy for S. stercoralis diagnosis. Besides high sensitivity, PCR may also enhance specificity by reducing microscopic misdiagnosis of morphologically similar helminth larvae (i.e. hookworm and S. stercoralis) in settings where both helminth species co-exist.

  19. Projected changes in the annual wind-wave cycle

    NASA Astrophysics Data System (ADS)

    Stopa, Justin; Hemer, Mark

    2016-04-01

    The uneven distribution of the sun's energy directly and indirectly drives physical atmosphere and ocean processes. This creates intricate spatial patterns within the seasonal cycle where higher order harmonics are seen to play an important role in regional climates. The annual cycle and associated harmonics are the strongest oscillations within the climate system and describe the majority of variance across the oceans. Consequently when studying climate oscillations, it is common practice to remove the seasonal cycle in order to elucidate inter-annual cycles. Furthermore the annual cycle plays an important role in the evolution of other inter-annual oscillations through non-linear coupling (e.g ENSO). Despite the important role of the seasons within the climate system very few studies describe the seasonality with any rigor. Therefore our focus is to describe the higher harmonics linked to the annual cycle and how they are expected to evolve in a changing climate. Using simulations from the Coordinated Ocean Wave Climate Project, the seasonality of multiple mid and end of the 21st century wind-wave climate projections are analyzed relative to historical experiment forced simulations. A comparison of various GCM forced wave simulations to reanalysis datasets reveals that a multi-model ensemble best describes the seasons. This ensemble is used to describe the changes within the wave seasonality. A systematic analysis reveals the primary mode of the seasons is relatively unchanged in the mid and end century. The largest changes occur in the second and third modes. The second mode defines the shift or translation within the seasons while the third mode characterizes relative change between the seasonal extremes (ie sharpening or flattening of the waveform). The relative changes in the second and third modes are not homogeneous and intricate patterns are revealed. Certain regions have sharper contrast in seasonality while other regions have a longer strong season. In

  20. Spatial and temporal patterns of morel fruiting.

    PubMed

    Mihail, Jeanne D; Bruhn, Johann N; Bonello, Pierluigi

    2007-03-01

    The biotic and abiotic factors conditioning morel fruit body production are incompletely known. We examined spatial and temporal patterns of Morchella esculenta fruiting over five years in a wooded site in Missouri, USA. Fruiting onset was inversely correlated with spring air and soil temperatures, whereas abundance was positively correlated with rain events (>10mm) during the 30 d preceding fruiting. The two years with the greatest fruiting had the shortest fruiting seasons (6-7d). Fruiting season length was positively correlated with soil warming, suggesting that a narrow range of optimum soil temperatures favour the explosive production of fruit bodies. All woody stems of at least 1cm diam were mapped and stem diameter and crown condition were noted. Morel fruit bodies were significantly closer to stems of Carya spp., Tilia americana and Ulmus americana than predicted by the frequencies of these woody species or their contribution to the total basal area on the site. Although intra-annual clustering of fruit bodies was often observed, inter-annual clustering was not. The spatial pattern of M. esculenta fruiting appears to be associated with vegetation pattern, whereas the onset and abundance of fruiting are determined by the interaction of spring temperatures with availability of supporting precipitation.

  1. Structure and palaeoenvironmental implications of inter-branch coenosteum-rich skeleton in corymbose Acropora species

    NASA Astrophysics Data System (ADS)

    Sadler, J.; Webb, G. E.; Nothdurft, L. D.

    2015-03-01

    Coral reefs provide an increasingly important archive of palaeoclimate data that can be used to constrain climate model simulations. Reconstructing past environmental conditions may also provide insights into the potential of reef systems to survive changes in the Earth's climate. Reef-based palaeoclimate reconstructions are predominately derived from colonies of massive Porites, with the most abundant genus in the Indo-Pacific— Acropora—receiving little attention owing to their branching growth trajectories, high extension rates and secondary skeletal thickening. However, inter-branch skeleton (consisting of both coenosteum and corallites) near the bases of corymbose Acropora colonies holds significant potential as a climate archive. This region of Acropora skeleton is atypical, having simple growth trajectories with parallel corallites, approximately horizontal density banding, low apparent extension rates and a simple microstructure with limited secondary thickening. Hence, inter-branch skeleton in Acropora bears more similarities to the coralla of massive corals, such as Porites, than to traditional Acropora branches. Cyclic patterns of Sr/Ca ratios in this structure suggest that the observed density banding is annual in nature, thus opening up the potential to use abundant corymbose Acropora for palaeoclimate reconstruction.

  2. InterAction Database (IADB)

    Cancer.gov

    The InterAction Database includes demographic and prescription information for more than 500,000 patients in the northern and middle Netherlands and has been integrated with other systems to enhance data collection and analysis.

  3. Scrophularia arguta, a widespread annual plant in the Canary Islands: a single recent colonization event or a more complex phylogeographic pattern?

    PubMed

    Valtueña, Francisco Javier; López, Josefa; Álvarez, Juan; Rodríguez-Riaño, Tomás; Ortega-Olivencia, Ana

    2016-07-01

    Many studies have addressed evolution and phylogeography of plant taxa in oceanic islands, but have primarily focused on endemics because of the assumption that in widespread taxa the absence of morphological differentiation between island and mainland populations is due to recent colonization. In this paper, we studied the phylogeography of Scrophularia arguta, a widespread annual species, in an attempt to determine the number and spatiotemporal origins of dispersal events to Canary Islands. Four different regions, ITS and ETS from nDNA and psbA-trnH and psbJ-petA from cpDNA, were used to date divergence events within S. arguta lineages and determine the phylogenetic relationships among populations. A haplotype network was obtained to elucidate the phylogenetic relationships among haplotypes. Our results support an ancient origin of S. arguta (Miocene) with expansion and genetic differentiation in the Pliocene coinciding with the aridification of northern Africa and the formation of the Mediterranean climate. Indeed, results indicate for Canary Islands three different events of colonization, including two ancient events that probably happened in the Pliocene and have originated the genetically most divergent populations into this species and, interestingly, a recent third event of colonization of Gran Canaria from mainland instead from the closest islands (Tenerife or Fuerteventura). In spite of the great genetic divergence among populations, it has not implied any morphological variation. Our work highlights the importance of nonendemic species to the genetic richness and conservation of island flora and the significance of the island populations of widespread taxa in the global biodiversity.

  4. Dynamics of a deep-water seagrass population on the Great Barrier Reef: annual occurrence and response to a major dredging program

    PubMed Central

    York, Paul H.; Carter, Alex B.; Chartrand, Kathryn; Sankey, Tonia; Wells, Linda; Rasheed, Michael A.

    2015-01-01

    Global seagrass research efforts have focused on shallow coastal and estuarine seagrass populations where alarming declines have been recorded. Comparatively little is known about the dynamics of deep-water seagrasses despite evidence that they form extensive meadows in some parts of the world. Deep-water seagrasses are subject to similar anthropogenic threats as shallow meadows, particularly along the Great Barrier Reef lagoon where they occur close to major population centres. We examine the dynamics of a deep-water seagrass population in the GBR over an 8 year period during which time a major capital dredging project occurred. Seasonal and inter-annual changes in seagrasses were assessed as well as the impact of dredging. The seagrass population was found to occur annually, generally present between July and December each year. Extensive and persistent turbid plumes from a large dredging program over an 8 month period resulted in a failure of the seagrasses to establish in 2006, however recruitment occurred the following year and the regular annual cycle was re-established. Results show that despite considerable inter annual variability, deep-water seagrasses had a regular annual pattern of occurrence, low resistance to reduced water quality but a capacity for rapid recolonisation on the cessation of impacts. PMID:26279474

  5. Inter-Hemispheric Oscillations in Human Sleep

    PubMed Central

    Imbach, Lukas L.; Werth, Esther; Kallweit, Ulf; Sarnthein, Johannes; Scammell, Thomas E.; Baumann, Christian R.

    2012-01-01

    Sleep is generally categorized into discrete stages based on characteristic electroencephalogram (EEG) patterns. This traditional approach represents sleep architecture in a static way, but it cannot reflect variations in sleep across time and across the cortex. To investigate these dynamic aspects of sleep, we analyzed sleep recordings in 14 healthy volunteers with a novel, frequency-based EEG analysis. This approach enabled comparison of sleep patterns with low inter-individual variability. We then implemented a new probability dependent, automatic classification of sleep states that agreed closely with conventional manual scoring during consolidated sleep. Furthermore, this analysis revealed a previously unrecognized, interhemispheric oscillation during rapid eye movement (REM) sleep. This quantitative approach provides a new way of examining the dynamic aspects of sleep, shedding new light on the physiology of human sleep. PMID:23144920

  6. Inter-hemispheric oscillations in human sleep.

    PubMed

    Imbach, Lukas L; Werth, Esther; Kallweit, Ulf; Sarnthein, Johannes; Scammell, Thomas E; Baumann, Christian R

    2012-01-01

    Sleep is generally categorized into discrete stages based on characteristic electroencephalogram (EEG) patterns. This traditional approach represents sleep architecture in a static way, but it cannot reflect variations in sleep across time and across the cortex. To investigate these dynamic aspects of sleep, we analyzed sleep recordings in 14 healthy volunteers with a novel, frequency-based EEG analysis. This approach enabled comparison of sleep patterns with low inter-individual variability. We then implemented a new probability dependent, automatic classification of sleep states that agreed closely with conventional manual scoring during consolidated sleep. Furthermore, this analysis revealed a previously unrecognized, interhemispheric oscillation during rapid eye movement (REM) sleep. This quantitative approach provides a new way of examining the dynamic aspects of sleep, shedding new light on the physiology of human sleep.

  7. Demographic and spatiotemporal patterns of avian influenza infection at the continental scale, and in relation to annual life cycle of a migratory host

    USGS Publications Warehouse

    Nallar, Rodolfo; Papp, Zsuzsanna; Epp, Tasha; Leighton, Frederick A.; Swafford, Seth R.; DeLiberto, Thomas J.; Dusek, Robert J.; Ip, Hon S.; Hall, Jeffrey S.; Berhane, Yohannes; Gibbs, Samantha E.J.; Soos, Catherine

    2015-01-01

    Since the spread of highly pathogenic avian influenza (HPAI) H5N1 in the eastern hemisphere, numerous surveillance programs and studies have been undertaken to detect the occurrence, distribution, or spread of avian influenza viruses (AIV) in wild bird populations worldwide. To identify demographic determinants and spatiotemporal patterns of AIV infection in long distance migratory waterfowl in North America, we fitted generalized linear models with binominal distribution to analyze results from 13,574 blue-winged teal (Anas discors, BWTE) sampled in 2007 to 2010 year round during AIV surveillance programs in Canada and the United States. Our analyses revealed that during late summer staging (July-August) and fall migration (September-October), hatch year (HY) birds were more likely to be infected than after hatch year (AHY) birds, however there was no difference between age categories for the remainder of the year (winter, spring migration, and breeding period), likely due to maturing immune systems and newly acquired immunity of HY birds. Probability of infection increased non-linearly with latitude, and was highest in late summer prior to fall migration when densities of birds and the proportion of susceptible HY birds in the population are highest. Birds in the Central and Mississippi flyways were more likely to be infected compared to those in the Atlantic flyway. Seasonal cycles and spatial variation of AIV infection were largely driven by the dynamics of AIV infection in HY birds, which had more prominent cycles and spatial variation in infection compared to AHY birds. Our results demonstrate demographic as well as seasonal, latitudinal and flyway trends across Canada and the US, while illustrating the importance of migratory host life cycle and age in driving cyclical patterns of prevalence.

  8. Trends in linezolid susceptibility patterns: report from the 2002-2003 worldwide Zyvox Annual Appraisal of Potency and Spectrum (ZAAPS) Program.

    PubMed

    Anderegg, Tamara R; Sader, Helio S; Fritsche, Thomas R; Ross, James E; Jones, Ronald N

    2005-07-01

    Linezolid is an important oxazolidinone antimicrobial for the treatment of infections caused by Gram-positive cocci, especially vancomycin-resistant enterococci and oxacillin-resistant Staphylococcus aureus (ORSA). Since its introduction, however, ribosomal mutations have been detected that produce resistance; thus, longitudinal surveillance remains necessary to monitor for emerging resistance in all geographic areas of oxazolidinone use. The 2003 Zyvox Annual Appraisal of Potency and Spectrum (ZAAPS) Program compared linezolid minimum inhibitory concentration (MIC) results with 13-15 comparator antimicrobial agents (8089 isolates) and also with results from an earlier surveillance period (2002). Sampling institutions in the United States of America (USA), Canada, Europe (seven nations), South America (three nations) and the Asia-Pacific (three nations) referred 200 Gram-positive cocci to the central laboratory for MIC processing and identification confirmation. Linezolid resistance (MIC > or = 8 mg/L) was established by alternative susceptibility testing methods as well as by ribosomal target characterisation. Concurrent drug use data were collected. Linezolid activity against the six major organism groups did not vary between years or geographic areas. In contrast, penicillin resistance increased 2% in Streptococcus pneumoniae; macrolide resistance was stable among beta-haemolytic streptococci (19-21%), but increased in S. pneumoniae (+2%); ORSA rates increased 4%; and vancomycin resistance in enterococci was present, but varied markedly by region. Non-clonal linezolid-resistant isolates were detected, each having the same G2576U 23S rRNA target mutation. Furthermore, the first linezolid-resistant, non-USA isolate (S. aureus in Greece) was observed, apparently related to linezolid use. In 2003, near complete activity for linezolid against Gram-positive isolates was again documented (99.93% susceptible) in the ZAAPS Program. Rare linezolid-resistant isolates were

  9. Large inter annual variation in air quality during the annual festival 'Diwali' in an Indian megacity.

    PubMed

    Parkhi, Neha; Chate, Dilip; Ghude, Sachin D; Peshin, Sunil; Mahajan, Anoop; Srinivas, Reka; Surendran, Divya; Ali, Kaushar; Singh, Siddhartha; Trimbake, Hanumant; Beig, Gufran

    2016-05-01

    A network of air quality and weather monitoring stations was established under the System of Air Quality Forecasting and Research (SAFAR) project in Delhi. We report observations of ozone (O3), nitrogen oxides (NOx), carbon monoxide (CO) and particulate matter (PM2.5 and PM10) before, during and after the Diwali in two consecutive years, i.e., November 2010 and October 2011. The Diwali days are characterised by large firework displays throughout India. The observations show that the background concentrations of particulate matter are between 5 and 10 times the permissible limits in Europe and the United States. During the Diwali-2010, the highest observed PM10 and PM2.5 mass concentration is as high as 2070µg/m3 and 1620μg/m(3), respectively (24hr mean), which was about 20 and 27 times to National Ambient Air Quality Standards (NAAQS). For Diwali-2011, the increase in PM10 and PM2.5 mass concentrations was much less with their peaks of 600 and of 390μg/m(3) respectively, as compared to the background concentrations. Contrary to previous reports, firework display was not found to strongly influence the NOx, and O3 mixing ratios, with the increase within the observed variability in the background. CO mixing ratios showed an increase. We show that the large difference in 2010 and 2011 pollutant concentrations is controlled by weather parameters.

  10. What attracts elk onto cattle pasture? Implications for inter-species disease transmission.

    PubMed

    Pruvot, M; Seidel, D; Boyce, M S; Musiani, M; Massolo, A; Kutz, S; Orsel, K

    2014-11-15

    In Southwest Alberta, beef cattle and wild elk (Cervus elaphus) have similar habitat preferences. Understanding their inter-species contact structure is important for assessing the risk of pathogen transmission between them. These spatio-temporal patterns of interactions are shaped, in part, by range management and environmental factors affecting elk distribution. In this study, resource selection modeling was used to identify factors influencing elk presence on cattle pasture and elk selection of foraging patches; furthermore, consequences for inter-species disease transmission were discussed. Data on pasture management practices and observations of elk were collected from 15 ranchers during interviews. Pasture use by elk was defined based on telemetry data (from GPS collars deployed on 168 elk in 7 herds) and rancher observations. At the patch scale, foraging patches used by elk were identified by spatio-temporal cluster analysis of telemetry data, whereas available patches were randomly generated outside the area delimited by used patches. For pastures and patches, landscape and human-managed features were characterized using remote sensing data and interviews, respectively. Attributes of available and used pastures (or patches) were compared using resource selection functions, on annual and seasonal (or annual and monthly) time scales. Additionally, intensity of pasture use was modeled using negative binomial regression. Cultivated hay land and mineral supplements were associated with elk presence on cattle pastures, whereas pastures with manure fertilization and higher traffic-weighted road densities were less likely to be used by elk. The effects of landscape (elevation, aspect, water access) and vegetation (forest cover, Normalized Difference Vegetation Index) characteristics on patch selection were consistent with typical elk habitat requirements. The presence of cattle and the traffic-weighted road density were negatively associated with patch selection

  11. Recurring patterns in bacterioplankton dynamics during coastal spring algae blooms

    PubMed Central

    Teeling, Hanno; Fuchs, Bernhard M; Bennke, Christin M; Krüger, Karen; Chafee, Meghan; Kappelmann, Lennart; Reintjes, Greta; Waldmann, Jost; Quast, Christian; Glöckner, Frank Oliver; Lucas, Judith; Wichels, Antje; Gerdts, Gunnar; Wiltshire, Karen H; Amann, Rudolf I

    2016-01-01

    A process of global importance in carbon cycling is the remineralization of algae biomass by heterotrophic bacteria, most notably during massive marine algae blooms. Such blooms can trigger secondary blooms of planktonic bacteria that consist of swift successions of distinct bacterial clades, most prominently members of the Flavobacteriia, Gammaproteobacteria and the alphaproteobacterial Roseobacter clade. We investigated such successions during spring phytoplankton blooms in the southern North Sea (German Bight) for four consecutive years. Dense sampling and high-resolution taxonomic analyses allowed the detection of recurring patterns down to the genus level. Metagenome analyses also revealed recurrent patterns at the functional level, in particular with respect to algal polysaccharide degradation genes. We, therefore, hypothesize that even though there is substantial inter-annual variation between spring phytoplankton blooms, the accompanying succession of bacterial clades is largely governed by deterministic principles such as substrate-induced forcing. DOI: http://dx.doi.org/10.7554/eLife.11888.001 PMID:27054497

  12. Patterns of Heart Attacks

    DTIC Science & Technology

    2010-06-01

    36 5.1 Pattern of gradually increasing occurrence of COPD .............................................. 37 5.2 Pattern of...deaths [1]. According to the Heart Disease and Stroke Statistics - 2010 Update from the American Heart Association, the estimated annual incidence of MI...7]. The study combined the insurance claims from the Medicare and the Manitoba Health Services Commission claims database with hospitalization

  13. IPRO--InterProfessional Project.

    ERIC Educational Resources Information Center

    Chang, Morris; Luh, Ding Bang

    The ability to work with different professions in a project-oriented setting is critical to today's engineering education. InterProfession (IPRO) projects, a three-credit course at the Illinois Institute of Technology, are integrated into the curriculum. Through these industry-sponsored projects, students will deal with real world engineering…

  14. Inter-Sectoral Educational Planning.

    ERIC Educational Resources Information Center

    Organisation for Economic Cooperation and Development, Paris (France).

    This book contains papers discussing inter-sectoral educational planning in countries belonging to the Organisation for Economic Co-operation and Development (OECD). Intersectoral educational planning is interpreted as educational policy formation by any country which takes into consideration influences generated by that country's social and…

  15. Evaluating Inter-Organizational Relationships.

    ERIC Educational Resources Information Center

    Intriligator, Barbara A.

    This paper presents a paradigm for evaluating an inter-organizational relationship (IOR) wherein two or more independent organizations agree to pool their authority, resources, and energies in order to achieve the goals they desire. Indicators of IOR effectiveness are clustered into four major categories: organizational situations, structural…

  16. Concussion induces gait inter-joint coordination variability under conditions of divided attention and obstacle crossing.

    PubMed

    Chiu, Shiu-Ling; Osternig, Louis; Chou, Li-Shan

    2013-09-01

    This study investigated the effect of concussion on the pattern and variability of inter-joint coordination during level walking (Level), obstacle crossing (OB), and walking with a concurrent cognitive test (ATT). Gait analyses of 23 concussed and 23 matched healthy adults were performed. Continuous relative phase (CRP), derived from phase angles of two adjacent joints, was used to assess inter-joint coordination. Cross-correlation measures and root-mean-square (RMS) differences were used to compare CRP patterns of the Level condition to those of OB and ATT conditions, respectively. Deviation phase (DP) was used to evaluate variability of inter-joint coordination for each task. For hip-knee and knee-ankle CRP patterns, RMS differences between OB and Level and between ATT and Level in concussed subjects were significantly greater than those of healthy adults. No significant group differences were detected for the cross-correlation measures of hip-knee and knee-ankle CRP patterns. In stance phase, a significant task effect on DP values was detected in hip-knee inter-joint coordination. For knee-ankle inter-joint coordination, concussed subjects showed significantly greater DP values than healthy controls during OB and ATT. In swing phase, concussed individuals showed greater DP values in hip-knee and knee-ankle inter-joint coordination compared to healthy controls. The findings suggest that the ability to modulate inter-joint coordination patterns when accommodating to gait perturbations is affected by concussion.

  17. Seasonal variations in the stable oxygen isotope ratio of wood cellulose reveal annual rings of trees in a Central Amazon terra firme forest.

    PubMed

    Ohashi, Shinta; Durgante, Flávia M; Kagawa, Akira; Kajimoto, Takuya; Trumbore, Susan E; Xu, Xiaomei; Ishizuka, Moriyoshi; Higuchi, Niro

    2016-03-01

    In Amazonian non-flooded forests with a moderate dry season, many trees do not form anatomically definite annual rings. Alternative indicators of annual rings, such as the oxygen (δ(18)Owc) and carbon stable isotope ratios of wood cellulose (δ(13)Cwc), have been proposed; however, their applicability in Amazonian forests remains unclear. We examined seasonal variations in the δ(18)Owc and δ(13)Cwc of three common species (Eschweilera coriacea, Iryanthera coriacea, and Protium hebetatum) in Manaus, Brazil (Central Amazon). E. coriacea was also sampled in two other regions to determine the synchronicity of the isotopic signals among different regions. The annual cyclicity of δ(18)Owc variation was cross-checked by (14)C dating. The δ(18)Owc showed distinct seasonal variations that matched the amplitude observed in the δ(18)O of precipitation, whereas seasonal δ(13)Cwc variations were less distinct in most cases. The δ(18)Owc variation patterns were similar within and between some individual trees in Manaus. However, the δ(18)Owc patterns of E. coriacea differed by region. The ages of some samples estimated from the δ(18)Owc cycles were offset from the ages estimated by (14)C dating. In the case of E. coriacea, this phenomenon suggested that missing or wedging rings may occur frequently even in well-grown individuals. Successful cross-dating may be facilitated by establishing δ(18)Owc master chronologies at both seasonal and inter-annual scales for tree species with distinct annual rings in each region.

  18. Synchoronous inter-hemispheric alpine glacier advances during the Late Glacial?

    NASA Astrophysics Data System (ADS)

    Bakke, Jostein; Paasche, Øyvind

    2016-04-01

    The termination of the last glaciation in both hemispheres was a period of rapid climate swings superimposed on the overall warming trend, resulting from large-scale reorganizations of the atmospheric and oceanic circulation patterns in both hemispheres. Environmental changes during the deglaciation have been inferred from proxy records, as well as by model simulations. Several oscillations took place both in northern and southern hemispheres caused by melt water releases such as during the Younger Dryas in north and the Antarctic Cold Reversal in south. However, a consensus on the hemispheric linkages through ocean and atmosphere are yet to be reached. Here we present a new multi-proxy reconstruction from a sub-annually resolved lake sediment record from Lake Lusvatnet in Arctic Norway compared with a new reconstruction from the same time interval at South Georgia, Southern Ocean, suggesting inter-hemispheric climate linkages during the Bølling/Allerød time period. Our reconstruction of the alpine glacier in the lake Lusvatnet catchment show a synchronous glacier advance with the Birch-hill moraine complex in the Southern Alps, New Zealand during the Intra Allerød Cooling period. We propose these inter hemispheric climate swings to be forced by the northward migration of the southern Subtropical Front during the Antarctic Cold Reversal. Such a northward migration of the Subtropical Front is shown in model simulation and in palaeorecords to reduce the Agulhas leakage impacting the strength of the Atlantic meridional overturning circulation. We simply ask if this can be the carrier of rapid climate swings from one hemisphere to another? Our high-resolution reconstructions provide the basis for an enhanced understanding of the tiny balance between migration of the Subtropical Front in the Southern Ocean and the teleconnection to northern hemisphere.

  19. 36 CFR 12.5 - Interments.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... REGULATIONS § 12.5 Interments. (a) Who may be interred. A person's eligibility for burial in a national... in accordance with NPS policy and VA Policy. (b) Burial permit. (1) A burial permit is required in... interred prior to receipt of a burial permit. (3) The superintendent shall process a burial permit...

  20. 36 CFR 12.5 - Interments.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... REGULATIONS § 12.5 Interments. (a) Who may be interred. A person's eligibility for burial in a national... in accordance with NPS policy and VA Policy. (b) Burial permit. (1) A burial permit is required in... interred prior to receipt of a burial permit. (3) The superintendent shall process a burial permit...

  1. 36 CFR 12.5 - Interments.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... REGULATIONS § 12.5 Interments. (a) Who may be interred. A person's eligibility for burial in a national... in accordance with NPS policy and VA Policy. (b) Burial permit. (1) A burial permit is required in... interred prior to receipt of a burial permit. (3) The superintendent shall process a burial permit...

  2. 36 CFR 12.5 - Interments.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... REGULATIONS § 12.5 Interments. (a) Who may be interred. A person's eligibility for burial in a national... in accordance with NPS policy and VA Policy. (b) Burial permit. (1) A burial permit is required in... interred prior to receipt of a burial permit. (3) The superintendent shall process a burial permit...

  3. 36 CFR 12.5 - Interments.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... REGULATIONS § 12.5 Interments. (a) Who may be interred. A person's eligibility for burial in a national... in accordance with NPS policy and VA Policy. (b) Burial permit. (1) A burial permit is required in... interred prior to receipt of a burial permit. (3) The superintendent shall process a burial permit...

  4. Phenological Differences Promote Coexistence in Sonoran Desert Winter Annuals

    NASA Astrophysics Data System (ADS)

    Kimball, S.; Angert, A.; Huxman, T.; Venable, L.

    2008-12-01

    Identifying trait differences is an important step toward understanding differential demographic responses to the same environmental fluctuations. In the Sonoran Desert, winter annual plants exhibit high demographic variability due to variation in precipitation, and patterns of demographic variability are related to species position along a tradeoff axis between relative growth rate (RGR) and water-use efficiency (WUE). Prior investigation revealed that species with high RGR and low WUE have greater inter-annual variability than species with low RGR and high WUE. In this study, we use long-term census data, climate records, and plot data to investigate timing of germination, reproduction, and senescence of several winter annual species in multiple years to test whether phenology relates to demographic variability and position along the tradeoff axis. We also use climate records to describe germination niches of the species and make predictions regarding future community composition. We hypothesized that seasonal phenology would differ such that demographically 'buffered' species (low RGR-high WUE) would germinate, flower, and senesce earlier in the season due to an ability to utilize small amounts of rain and photosynthesize at low temperatures. In contrast, we hypothesized that the demographically 'variable' species (high RGR-low WUE) would germinate later in the season, only after enough rain had fallen to break seed dormancy. Consistent with our hypothesis, buffered species did germinate and reproduce earlier in the season than variable species. Contrary to our hypothesis, buffered species also survived later into the season. Variable species germinated later, reproduced quickly, and senesced earlier in the season. These results show that phenology promotes coexistence by partitioning resource use. Germination niches and climate data suggest that buffered species may increase in abundance through time.

  5. Numerical simulation of fluorescent annual layer in stalagmites: implication for extracting sub-annual information

    NASA Astrophysics Data System (ADS)

    Onishi, Yuri; Sasaki, Hana; Ishihara, Yoshiro; Yoshimura, Kazuhisa

    2016-04-01

    Fluorescent annual layers are frequently reported from stalagmites in various caves of the world. In recent years, fluorescent asymmetrical patterns in annual layers, such as fluorescent intensity growing upward and interrupting at uppermost part in a layer, have also been reported. Since the formation of annual layers in stalagmites is probably influenced by the accumulation rates of calcite and fulvic acids in dripwaters, the parameters controlling the fluorescent asymmetrical patterns of annual layers are not clarified. In this study, we reviewed various types of fluorescence patterns in annual layers reported from Japan, and simulated them considering the accumulation conditions of stalagmite and the amount of fulvic acids in dripwaters. Hence, it is suggested that formation of various types of fluorescent annual layer is influenced by (1) seasonal fluctuations in the accumulation rate of stalagmites and the amounts of fulvic acids in dripwaters, (2) seasonal time lags between favorable conditions for stalagmite accumulation and the predominant season for accumulation of fulvic acids in dripwaters, and (3) durations of the lags. The time lags are caused by seasonal gaps between variations in the amounts of fulvic acids in dripwaters and the accumulation rates of stalagmite influenced by dripwater intervals and cave air conditions. The results of this study will provide new insight into the seasonal signature in annual layers and suggest that the geochemical information bias from stalagmites can be evaluated from analyses of the annual layer patterns.

  6. Strange-face illusions during inter-subjective gazing.

    PubMed

    Caputo, Giovanni B

    2013-03-01

    In normal observers, gazing at one's own face in the mirror for a few minutes, at a low illumination level, triggers the perception of strange faces, a new visual illusion that has been named 'strange-face in the mirror'. Individuals see huge distortions of their own faces, but they often see monstrous beings, archetypal faces, faces of relatives and deceased, and animals. In the experiment described here, strange-face illusions were perceived when two individuals, in a dimly lit room, gazed at each other in the face. Inter-subjective gazing compared to mirror-gazing produced a higher number of different strange-faces. Inter-subjective strange-face illusions were always dissociative of the subject's self and supported moderate feeling of their reality, indicating a temporary lost of self-agency. Unconscious synchronization of event-related responses to illusions was found between members in some pairs. Synchrony of illusions may indicate that unconscious response-coordination is caused by the illusion-conjunction of crossed dissociative strange-faces, which are perceived as projections into each other's visual face of reciprocal embodied representations within the pair. Inter-subjective strange-face illusions may be explained by the subject's embodied representations (somaesthetic, kinaesthetic and motor facial pattern) and the other's visual face binding. Unconscious facial mimicry may promote inter-subjective illusion-conjunction, then unconscious joint-action and response-coordination.

  7. Salt bridges at the inter-ring interface regulate the thermostat of GroEL.

    PubMed

    Sot, Begoña; Galán, Asier; Valpuesta, Jose María; Bertrand, Sara; Muga, Arturo

    2002-09-13

    The chaperonin GroEL consists of a double-ring structure made of identical subunits and displays unusual allosteric properties caused by the interaction between its constituent subunits. Cooperative binding of ATP to a protein ring allows binding of GroES to that ring, and at the same time negative inter-ring cooperativity discharges the ligands from the opposite ring, thus driving the protein-folding cycle. Biochemical and electron microscopy analysis of wild type GroEL, a single-ring mutant (SR1), and two mutants with one inter-ring salt bridge of the chaperonin disrupted (E461K and E434K) indicate that these ion pairs form part of the interactions that allow the inter-ring allosteric signal to be transmitted. The wild type-like activities of the ion pair mutants at 25 degrees C are in contrast with their lack of inter-ring communication and folding activity at physiological temperatures. These salt bridges stabilize the inter-ring interface and maintain the inter-ring spacing so that functional communication between protein heptamers takes place. The characterization of GroEL hybrids containing different amounts of wild type and mutant subunits also indicates that as the number of inter-ring salt bridges increases the functional properties of the hybrids recover. Taken together, these results strongly suggest that inter-ring salt bridges form a stabilizing ring-shaped, ionic zipper that ensures inter-ring communication at the contact sites and therefore a functional protein-folding cycle. Furthermore, they regulate the chaperonin thermostat, allowing GroEL to distinguish physiological (37 degrees C) from stress temperatures (42 degrees C).

  8. Inter-satellite links for cubesats

    NASA Astrophysics Data System (ADS)

    Budianu, A.; Castro, T. J. W.; Meijerink, A.; Bentum, M. J.

    Realizing inter-satellite links is a must for ensuring the success of cubesat swarm missions. Nevertheless, it has hardly been considered until now. The communication systems for cubesats have to deal with a few peculiar demands regarding consumed power, geometry and throughput. Depending on the type of application, required data rates can go up to tens of megabits per second, while power consumption and physical size are limited by the platform. The proposed communication scheme will combine power-efficient modulation and channel coding with multiple access and spread spectrum techniques, enabling the deployment of multiple satellites. Apart from this, the antenna system has to be designed such that links can be established and maintained independent of the satellites' orientation. An electrically steerable radiation pattern is achieved by placing antennas on each face of the cube. Conformal beamforming provides the system with 5 dBi gain for any desired direction of transmission, eliminating the need for attitude control. Furthermore, using planar antennas reduces the complexity of the mechanical part as they require no deployment.

  9. Inter-individual cognitive variability in children with Asperger's syndrome

    PubMed Central

    Gonzalez-Gadea, Maria Luz; Tripicchio, Paula; Rattazzi, Alexia; Baez, Sandra; Marino, Julian; Roca, Maria; Manes, Facundo; Ibanez, Agustin

    2014-01-01

    Multiple studies have tried to establish the distinctive profile of individuals with Asperger's syndrome (AS). However, recent reports suggest that adults with AS feature heterogeneous cognitive profiles. The present study explores inter-individual variability in children with AS through group comparison and multiple case series analysis. All participants completed an extended battery including measures of fluid and crystallized intelligence, executive functions, theory of mind, and classical neuropsychological tests. Significant group differences were found in theory of mind and other domains related to global information processing. However, the AS group showed high inter-individual variability (both sub- and supra-normal performance) on most cognitive tasks. Furthermore, high fluid intelligence correlated with less general cognitive impairment, high cognitive flexibility, and speed of motor processing. In light of these findings, we propose that children with AS are characterized by a distinct, uneven pattern of cognitive strengths and weaknesses. PMID:25132817

  10. Inter-individual cognitive variability in children with Asperger's syndrome.

    PubMed

    Gonzalez-Gadea, Maria Luz; Tripicchio, Paula; Rattazzi, Alexia; Baez, Sandra; Marino, Julian; Roca, Maria; Manes, Facundo; Ibanez, Agustin

    2014-01-01

    Multiple studies have tried to establish the distinctive profile of individuals with Asperger's syndrome (AS). However, recent reports suggest that adults with AS feature heterogeneous cognitive profiles. The present study explores inter-individual variability in children with AS through group comparison and multiple case series analysis. All participants completed an extended battery including measures of fluid and crystallized intelligence, executive functions, theory of mind, and classical neuropsychological tests. Significant group differences were found in theory of mind and other domains related to global information processing. However, the AS group showed high inter-individual variability (both sub- and supra-normal performance) on most cognitive tasks. Furthermore, high fluid intelligence correlated with less general cognitive impairment, high cognitive flexibility, and speed of motor processing. In light of these findings, we propose that children with AS are characterized by a distinct, uneven pattern of cognitive strengths and weaknesses.

  11. Elevation Pattern in Growth Coherency on the Southeastern Tibetan Plateau

    PubMed Central

    Lyu, Lixin; Deng, Xu; Zhang, Qi-Bin

    2016-01-01

    It is generally expected that inter-annual changes in radial growth among trees would be similar to the increase in altitude due to the limitation of increasingly harsher climatic factors. Here, we examine whether this pattern exists in alpine forests on the southeastern Tibetan Plateau. Increment cores were collected from mature trees at the lower, middle and upper limits of balfour spruce (Picea likiangensis var. balfouriana (Rehd. et Wils.) Hillier ex Slsvin) forests at the Buze and Yela Mountains in Basu County, Changdu Prefecture of Tibet, China. The treeline elevations are 4320 m and 4510 m a.s.l. for Buze and Yela, respectively. Tree-ring widths were measured, crossdated, and detrended to obtain a sequence of ring-width indices for each individual sample. Annual growth rate, climate sensitivity, growth-climate relationships, and growth synchrony among trees were calculated and compared across altitudes. In Buze Mountain, the annual growth rate of trees has no significant difference across altitudes. The mean sensitivity of trees is lower at the treelines than at lower elevations. Tree growth has stronger correlation with winter temperature at upper elevations than at lower elevations, has significant correlation with moisture, not temperature, in the growing season, and the growth response to moisture is lower at the treeline than at lower elevations. The correlation among individual tree-ring sequences is lower at the treeline than at sites at lower elevation. In Yela Mountain, the characterisitics of annual growth rate, mean sensitivity, tree growth-climate relationships, and inter-serial correlation are similar to those in Buze, but their differences along altitudinal gradients are less significant as those in Buze. Our data do not support the general expectation of growth convergence among individuals with increasing altitude. We conclude that individual heterogeneity and microhabitat diversity are important features for treeline trees that may dampen

  12. Education Policy and the 'Inter'-Regnum

    ERIC Educational Resources Information Center

    Hartley, David

    2007-01-01

    In the UK, the vocabulary of public services is becoming infused with the prefixes "inter"-, "multi-" and "co-". Public-sector agencies are being encouraged to adopt"'multi"- or "inter-agency" configurations; "workforce reform" seeks to dissolve once-impermeable professional boundaries;…

  13. Inter-laboratory comparison measurements of radiochemical laboratories in Slovakia.

    PubMed

    Meresová, J; Belanová, A; Vrsková, M

    2010-01-01

    The first inter-laboratory comparison organized by the radiochemistry laboratory of Water Research Institute (WRI) in Bratislava was carried out in 1993 and since then is it realized on an annual basis and about 10 radiochemical laboratories from all over Slovakia are participating. The gross alpha and gross beta activities, and the activity concentrations of (222)Rn, tritium, and (226)Ra, and U(nat) concentration in synthetic water samples are compared. The distributed samples are covering the concentration range prevailing in potable and surface waters and are prepared by dilution of certified reference materials. Over the course of the years 1993-2008, we observed the improvement in the quality of results for most of the laboratories. However, the success rate of the gross alpha determination activity is not improving as much as the other parameters.

  14. Annual Energy Review 1999

    SciTech Connect

    Seiferlein, Katherine E.

    2000-07-01

    A generation ago the Ford Foundation convened a group of experts to explore and assess the Nation’s energy future, and published their conclusions in A Time To Choose: America’s Energy Future (Cambridge, MA: Ballinger, 1974). The Energy Policy Project developed scenarios of U.S. potential energy use in 1985 and 2000. Now, with 1985 well behind us and 2000 nearly on the record books, it may be of interest to take a look back to see what actually happened and consider what it means for our future. The study group sketched three primary scenarios with differing assumptions about the growth of energy use. The Historical Growth scenario assumed that U.S. energy consumption would continue to expand by 3.4 percent per year, the average rate from 1950 to 1970. This scenario assumed no intentional efforts to change the pattern of consumption, only efforts to encourage development of our energy supply. The Technical Fix scenario anticipated a “conscious national effort to use energy more efficiently through engineering know-how." The Zero Energy Growth scenario, while not clamping down on the economy or calling for austerity, incorporated the Technical Fix efficiencies plus additional efficiencies. This third path anticipated that economic growth would depend less on energy-intensive industries and more on those that require less energy, i.e., the service sector. In 2000, total energy consumption was projected to be 187 quadrillion British thermal units (Btu) in the Historical Growth case, 124 quadrillion Btu in the Technical Fix case, and 100 quadrillion Btu in the Zero Energy Growth case. The Annual Energy Review 1999 reports a preliminary total consumption for 1999 of 97 quadrillion Btu (see Table 1.1), and the Energy Information Administration’s Short-Term Energy Outlook (April 2000) forecasts total energy consumption of 98 quadrillion Btu in 2000. What energy consumption path did the United States actually travel to get from 1974, when the scenarios were drawn

  15. [Effect of climate change on the fisheries conununity pattern in the overwintering ground of open waters of northern East China Sea].

    PubMed

    Liu, Zun-lei; Yuan, Xing-wei; Yang, Lin-lin; Yan, Li-ping; Tian, Yong-jun; Chen, Jia-hua

    2015-03-01

    Data sets of 26 fisheries target species from the fishery-depen-dent and fishery-independent surveys in the overwintering ground of open waters of northern East China Sea (OW-NECS), combined sea surface temperature (SST), were used to examine the links between diversity index, pattern of common variability and climate changes based on the principal component analysis (PCA) and generalized additive model (GAM). The results showed that the shift from a cold regime to a warm regime was detected in SST during the 1970s-2011 with step changes around 1982/ 1983. SST increased during the cold regime and the warm regime before 1998 (warming trend period, 1972-1998), and decreased during the warm regime after 1998 (cooling trend period, 1999-2011). Shannon diversity index was largely dependent on the filefish, which contributed up to 50% of the total production as a single species, with low diversity in the waters of the OW-NECS, during the late 1980s and early 1990s. Excluding the filefish, the diversity index linearly increased and decreased during 1972-1998 and 1999-2011, respectively. The variation pattern generally corresponds with the trend in water temperature, strongly suggesting the effect of the SST on the diversity. The first two components (PC1 and PC2) of PCA for target species, which accounted for 32.43% of the total variance, showed evident decadal variation patterns with a step change during 1992-1999 and inter-annual variability with short-period fluctuation, respectively. It seems that PC1 was associated with large scale climatic change, while PC2 was related to inter-annual oceanographic variability such as ENSO events. Linear fitting results showed winEOF1 had significant effect on PC1, and GAM analysis for PC1 showed that winter EOF1 (winEOF1) and summer EOF2 (sumEOF2) can explain 88.9% of the total variance. Nonlinear effect was also found between PC2 and win EOF1, indicating that the fish community structure, which had predominantly decadal/inter-annual

  16. Patterns of Broken Patterns

    NASA Astrophysics Data System (ADS)

    Field, R. W.; Park, G. B.; Changala, P. B.; Baraban, J. H.; Stanton, J. F.; Merer, A. J.

    2013-06-01

    Spectroscopy - it is all about patterns. Some patterns look so indescribably complicated that, unlike pornography, you do not know one when you see one. It is tempting to say that, at high vibrational excitation, interactions among normal mode basis states are so strong and widespread that all patterns are obliterated. But this is not true. When normal mode frequencies are in near integer multiple ratios, polyads emerge. A polyad is a robust pattern often comprising many vibrational eigenstates. Each such pattern might span many hundreds of cm^{-1}, and it is inevitable that several unrelated polyad patterns overlap. When polyads overlap, it might seem impossible to disentangle them. However, the key to disentanglement is that polyads come in families in which successive generations are related by harmonic oscillator matrix element selection and scaling rules. Families of polyads are described by families of scaling-based effective Hamiltonian matrices, {H}^{{eff}}. No matter how complex and overlapped, the polyad {H}^{{eff}} serves as a magic decoder for picking out the polyad pattern. Sometimes the polyad patterns are systematically broken (a meta-pattern), owing to proximity to an isomerization barrier, as occurs in highly excited bending levels of the S_{1} state of HCCH, which encode the trans-cis minimum energy isomerization path. Quantum Chemists often dismiss {H}^{{eff}} models, precisely because they are models that do not express the full dimensionality of the complete Hamiltonian. But an {H}^{{eff}} explains rather than describes. Shunning {H}^{{eff}}s is like throwing out the baby with the bath water. Don't do it!

  17. O the Genesis of Anomalous SST and Rainfall Patterns Over the Tropical Atlantic Basin

    NASA Astrophysics Data System (ADS)

    Nobre, Paulo

    Empirical orthogonal functions (EOFs), correlation, and composite analyses are used to investigate the evolution of phenomena associated with sea surface temperature (SST) and rainfall variability over the tropical Atlantic. The most important findings in this research are as follows. 1. The well known droughts over northeastern Brazil (Nordeste) are a local manifestation of a much larger -scale anomalies pattern encompassing the whole equatorial Atlantic and Amazon region. 2. The large-scale dipole-like anomalous rainfall pattern over the equatorial Atlantic and Amazon in March, April, and May (MAM), which is the rainy season for Nordeste region, is a consequence of meridional displacements of the inter-tropical convergence zone (ITCZ). In particular, negative rainfall anomalies to the south of the equator during MAM are related to an early withdrawal of ITCZ towards the warm SST anomalies over the northern tropical Atlantic. Concurrent with the rainfall anomaly dipole, there are large-scale patterns of SST and wind stress over the tropical Atlantic Ocean which also show a prominent dipole-like structure. The dipole patterns of SST and surface wind stress are the most dominant mode of interannual variability. Weaker trade winds are associated with warmer SST; stronger trade winds with cooler SST. 3. The spatial structure of (dipole-like) anomalous SST, rainfall and surface wind stress during MAM are clearly a modulation of the annual cycle for that season. The similarity between the patterns of interannual variability and MAM seasonal anomalies (departure from the annual mean) is quite remarkable. 4. Previous work has suggested the direct influence of the El Nino/Southern Oscillation (ENSO) on the southern Atlantic. This study brings observational evidence that ENSO effect over the northern Atlantic may happen through teleconnection patterns into higher latitudes of the Northern Hemisphere. The teleconnection effects over the northern Atlantic are out of phase

  18. Improving the Accuracy of Laplacian Estimation with Novel Variable Inter-Ring Distances Concentric Ring Electrodes

    PubMed Central

    Makeyev, Oleksandr; Besio, Walter G.

    2016-01-01

    Noninvasive concentric ring electrodes are a promising alternative to conventional disc electrodes. Currently, the superiority of tripolar concentric ring electrodes over disc electrodes, in particular, in accuracy of Laplacian estimation, has been demonstrated in a range of applications. In our recent work, we have shown that accuracy of Laplacian estimation can be improved with multipolar concentric ring electrodes using a general approach to estimation of the Laplacian for an (n + 1)-polar electrode with n rings using the (4n + 1)-point method for n ≥ 2. This paper takes the next step toward further improving the Laplacian estimate by proposing novel variable inter-ring distances concentric ring electrodes. Derived using a modified (4n + 1)-point method, linearly increasing and decreasing inter-ring distances tripolar (n = 2) and quadripolar (n = 3) electrode configurations are compared to their constant inter-ring distances counterparts. Finite element method modeling and analytic results are consistent and suggest that increasing inter-ring distances electrode configurations may decrease the truncation error resulting in more accurate Laplacian estimates compared to respective constant inter-ring distances configurations. For currently used tripolar electrode configuration, the truncation error may be decreased more than two-fold, while for the quadripolar configuration more than a six-fold decrease is expected. PMID:27294933

  19. School of Optometry at Inter American University.

    ERIC Educational Resources Information Center

    Hofstetter, Henry W.

    1981-01-01

    The optometry program at the Inter American University in Puerto Rico is profiled, with highlights of admission criteria, temporary and permanent facilities, faculty, governance structure, curriculum, research opportunities, and relationship with the university as a whole. (MSE)

  20. Synchronous inter-hemispheric alpine glacier advances during the Antarctic Cold Reversal

    NASA Astrophysics Data System (ADS)

    Bakke, J.; Bradley, R. S.; Dahl, S.; Balascio, N. L.

    2013-12-01

    The termination of the last glaciation in both hemispheres was a period of rapid climate oscillations superimposed on the overall warming trend, resulting from large-scale reorganizations of the atmospheric and oceanic circulation patterns in both hemispheres. Environmental changes during the deglaciation have been inferred from proxy records, as well as by model simulations. Several oscillations took place in both the northern and southern hemispheres caused by melt water releases such as during the Younger Dryas in the north and the Antarctic Cold Reversal in the south. However, a consensus on the hemispheric linkages through ocean and atmosphere are yet to be reached. Here we present a new multi-proxy reconstruction from a sub-annually resolved lake sediment record from lake Lusvatnet in arctic Norway suggesting inter-hemispheric climate linkages during the Bølling/Allerød time period. Our reconstruction of the Lusvatnet cirque glacier shows a synchronous glacier advance with the Birch-hill moraine complex in the Southern Alps, New Zealand, during the Intra Allerød Cooling. We propose these inter-hemispheric climate oscillations to be forced by the northward migration of the southern Subtropical Front during the Antarctic Cold Reversal. Such a northward migration of the Subtropical Front is shown in model simulation and in palaeorecords to reduce the Agulhas leakage impacting the strength of the Atlantic meridional overturning circulation. The Bølling-Allerød time period was a warm interval in the North Atlantic with a strong Atlantic meridional overturning circulation setting the stage for the later fresh water forcing of the Younger Dryas cold reversal with reduced overturning. Two minor cold reversals, the Older Dryas and the Intra Allerød Cooling, took place during this time span and we suggest a reduction in the Agulhas leakage during peak cooling over Antarctica as the mechanism teleconnecting arctic rapid climate oscillations with rapid climate

  1. Access to Inter-Organization Computer Networks.

    DTIC Science & Technology

    1985-08-01

    provided to the M1T Laboratory for Computer Science by the IBM Corporation . 2 . . o Access to Inter-Organization Computer Networks Abstract Whcn two or...4: Example of category tables for the MIT Multics system. 170 Figure 8-5: Example of category tables for corporate R&D. 172 Figure 12- 1: Background...mail use at Digital Equipment Corporation . He compared the costs of two different internal electronic mail systems with telephone and inter-office

  2. Inter-comparison of precipitable water among reanalyses and its effect on downscaling in the tropics

    NASA Astrophysics Data System (ADS)

    Takahashi, H. G.; Fujita, M.; Hara, M.

    2012-12-01

    This paper compared precipitable water (PW) among four major reanalyses. In addition, we also investigated the effect of the boundary conditions on downscaling in the tropics, using a regional climate model. The spatial pattern of PW in the reanalyses agreed closely with observations. However, the absolute amounts of PW in some reanalyses were very small compared to observations. The discrepancies of the 12-year mean PW in July over the Southeast Asian monsoon region exceeded the inter-annual standard deviation of the PW. There was also a discrepancy in tropical PWs throughout the year, an indication that the problem is not regional, but global. The downscaling experiments were conducted, which were forced by the different four reanalyses. The atmospheric circulation, including monsoon westerlies and various disturbances, was very small among the reanalyses. However, simulated precipitation was only 60 % of observed precipitation, although the dry bias in the boundary conditions was only 6 %. This result indicates that dry bias has large effects on precipitation in downscaling over the tropics. This suggests that a simulated regional climate downscaled from ensemble-mean boundary conditions is quite different from an ensemble-mean regional climate averaged over the several regional ones downscaled from boundary conditions of the ensemble members in the tropics. Downscaled models can provide realistic simulations of regional tropical climates only if the boundary conditions include realistic absolute amounts of PW. Use of boundary conditions that include realistic absolute amounts of PW in downscaling in the tropics is imperative at the present time. This work was partly supported by the Global Environment Research Fund (RFa-1101) of the Ministry of the Environment, Japan.

  3. A single-substrate model to interpret high-resolution intra-annual stable isotope signals in tree ring cellulose

    NASA Astrophysics Data System (ADS)

    Ogée, J.; Barbour, M. M.; Dewar, R. C.; Wingate, L.; Bert, D.; Bosc, A.; Lambrot, C.; Stievenard, M.; Bariac, T.; Berbigier, P.; Loustau, D.

    2007-12-01

    High-resolution measurements of the carbon and oxygen stable isotope composition of cellulose in annual tree rings (δ13Ccellulose and δ18Ocellulose, respectively) reveal well-defined seasonal patterns that could contain valuable records of past climate and tree function. Interpreting these signals is nonetheless complex because they not only record the signature of current assimilates, but also depend on carbon allocation dynamics within the trees. Here, we will present a single-substrate model for wood growth in order to interpret qualitatively and quantitatively these seasonal isotopic signals. We will also show how this model can relate to more complex models of phloem transport and cambial activity. The model will then be tested against an isotopic intra-annual chronology collected on a Pinus pinaster tree equipped with point dendrometers and growing on a Carboeurope site where climate, soil and flux variables are also monitored. The empirical δ13Ccellulose and δ18Ocellulose signals exhibit dynamic seasonal patterns with clear differences between years, which makes it suitable for model testing. We will show how our simple model of carbohydrate reserves, forced by sap flow and eddy covariance measurements, enables us to interpret these seasonal and inter-annual patterns. Finally, we will present a sensitivity analysis of the model, showing how gas-exchange parameters, carbon and water pool sizes or wood maturation times affect these isotopic signals. Acknowledgements: this study benefited from the CarboEurope-IP Bray site facilities and was funded by the French INSU programme Eclipse, with an additional support from the INRA department EFPA.

  4. Quantifying Inter-Segmental Coordination during the Instep Soccer Kicks

    PubMed Central

    LI, YUMENG; ALEXANDER, MARION; GLAZEBROOK, CHERYL; LEITER, JEFF

    2016-01-01

    In order to generate a high ball speed in soccer, the inter-segmental coordination of the kicking leg is critical. The purpose of this study was to quantify the coordination between the thigh and shank movement in the sagittal plane during instep kicks. Eleven female soccer players were video recorded using a high-speed (80 Hz) video camera during penalty kicks. Hip, knee and ankle joint centers of the right leg were digitized, and the movement was analyzed using Dartfish TeamPro (6.0). The thigh and shank segment angles were generated, and the coordination was quantified using the cross-correlation and the vector coding method. Four coordination patterns were defined based on coupling angles: in-phase, anti-phase, thigh-phase and shank-phase. The time spent in each coordination pattern was analyzed. The cross-correlation coefficient was positive for all the participants, indicating that the two segments rotated with similar patterns. Based on the vector coding method, we observed dominant coordination patterns of shank-phase and in-phase during the backswing and forward swing phase, respectively. We hope the outcomes of our study could provide a better understanding of soccer kicking coordination and benefit training young soccer players. Future studies may use the methodology and outcomes in the present study to investigate the coordination of different levels of players to better understand the process of skill acquisition. PMID:27990225

  5. On the relationship between large-scale climate modes and regional synoptic patterns that drive Victorian rainfall

    NASA Astrophysics Data System (ADS)

    Verdon-Kidd, D. C.; Kiem, A. S.

    2009-04-01

    In this paper regional (synoptic) and large-scale climate drivers of rainfall are investigated for Victoria, Australia. A non-linear classification methodology known as self-organizing maps (SOM) is used to identify 20 key regional synoptic patterns, which are shown to capture a range of significant synoptic features known to influence the climate of the region. Rainfall distributions are assigned to each of the 20 patterns for nine rainfall stations located across Victoria, resulting in a clear distinction between wet and dry synoptic types at each station. The influence of large-scale climate modes on the frequency and timing of the regional synoptic patterns is also investigated. This analysis revealed that phase changes in the El Niño Southern Oscillation (ENSO), the Indian Ocean Dipole (IOD) and/or the Southern Annular Mode (SAM) are associated with a shift in the relative frequency of wet and dry synoptic types on an annual to inter-annual timescale. In addition, the relative frequency of synoptic types is shown to vary on a multi-decadal timescale, associated with changes in the Inter-decadal Pacific Oscillation (IPO). Importantly, these results highlight the potential to utilise the link between the regional synoptic patterns derived in this study and large-scale climate modes to improve rainfall forecasting for Victoria, both in the short- (i.e. seasonal) and long-term (i.e. decadal/multi-decadal scale). In addition, the regional and large-scale climate drivers identified in this study provide a benchmark by which the performance of Global Climate Models (GCMs) may be assessed.

  6. Annual Growth Bands in Hymenaea courbaril

    SciTech Connect

    Westbrook, J A; Guilderson, T P; Colinvaux, P A

    2004-02-09

    One significant source of annual temperature and precipitation data arises from the regular annual secondary growth rings of trees. Several tropical tree species are observed to form regular growth bands that may or may not form annually. Such growth was observed in one stem disk of the tropical legume Hymenaea courbaril near the area of David, Panama. In comparison to annual reference {Delta}{sup 14}C values from wood and air, the {Delta}{sup 14}C values from the secondary growth rings formed by H. courbaril were determined to be annual in nature in this one stem disk specimen. During this study, H. courbaril was also observed to translocate recently produced photosynthate into older growth rings as sapwood is converted to heartwood. This process alters the overall {Delta}{sup 14}C values of these transitional growth rings as cellulose with a higher {Delta}{sup 14}C content is translocated into growth rings with a relatively lower {Delta}{sup 14}C content. Once the annual nature of these growth rings is established, further stable isotope analyses on H. courbaril material in other studies may help to complete gaps in the understanding of short and of long term global climate patterns.

  7. Stem tilting in the inter-tropical cactus Echinocactus platyacanthus: an adaptive solution to the trade-off between radiation acquisition and temperature control.

    PubMed

    Herce, M F; Martorell, C; Alonso-Fernandez, C; Boullosa, L F V V; Meave, J A

    2014-05-01

    While plants require radiation for photosynthesis, radiation in warm deserts can have detrimental effects from high temperatures. This dilemma may be solved through plant morphological attributes. In cold deserts, stem tilting keeps reproductive organs warm by increasing radiation interception at the cost of decreased annual light interception. Conversely, little is known about stem tilting in warm deserts. We hypothesised that stem tilting in Echinocactus platyacanthus prevents high temperatures near the apex, where reproduction occurs. The study was conducted in the warm, inter-tropical portion of the Chihuahuan Desert, Mexico. We found that cacti preferentially tilted towards the south, which reduced temperatures of reproductive organs during the hot season, but increased total annual near-apex PAR interception. Tilting also maximised reproduction, a likely consequence of temperature control but perhaps also of the difficulty in translocating photosynthates in cacti; therefore, annual energy acquisition near floral meristems may be largely allocated to reproduction. Unlike plants of higher latitudes, in inter-tropical deserts sunlight at noon comes either from the north or the south, depending on the season, and thus stem tilting may more strongly affect total annual radiation received in different portions of the stem. Inter-tropical cacti can synchronise reproduction with irradiance peaks if flowering occurs in a specific (north or south) portion of the stem; also, they effectively solve the conflict between maximising annual PAR interception and minimising temperature at the hottest time of day. Notably, the two inter-tropical cacti in which stem tilting has been studied successfully solve this conflict.

  8. Annual Energy Review, 2008

    SciTech Connect

    2009-06-01

    The Annual Energy Review (AER) is the Energy Information Administration's (EIA) primary report of annual historical energy statistics. For many series, data begin with the year 1949. Included are statistics on total energy production, consumption, trade, and energy prices; overviews of petroleum, natural gas, coal, electricity, nuclear energy, renewable energy, and international energy; financial and environment indicators; and data unit conversions.

  9. Intra- and Inter-Rater Reliability of the Modified Tuck Jump Assessment

    PubMed Central

    Fort-Vanmeerhaeghe, Azahara; Montalvo, Alicia M.; Lloyd, Rhodri S.; Read, Paul; Myer, Gregory D.

    2017-01-01

    The Tuck Jump Assessment (TJA) is a clinician-friendly screening tool that was designed to support practitioners with identification of neuromuscular deficits associated with anterior cruciate ligament injury. This study aimed to evaluate the inter- and intra-rater reliability of the modified scoring (0 to 2) TJA to add an additional range of objectivity for each criterion. A total of 24 elite youth volleyball athletes (12 males and 12 females) were included in this study. Each participant’s recorded performance of the TJA was scored independently by two raters across ten criteria using the modified scale. The two raters then scored the same videos one week later. Another investigator who was blind to the identity of the raters analyzed the scores from both raters for each participant. Kappa coefficient (k) and percentage of exact agreement (PEA) for both intra- and inter-rater reliability were analyzed for each item. Intraclass correlation coefficients (ICC) were calculated to determine intra- and inter-rater reliability of the modified TJA total score. Intra- and inter-rater k was good to excellent for most items (0.65-0.91). Average PEA between the two raters and two sessions ranged from 83.3 to 100% in all scored items. The ICC for the total score was excellent in both inter- and inter-rater correlations (0.94-0.96). This research demonstrated that the modified version of the TJA predominantly shows good to excellent intra- and inter-rater reliability in all analyzed criteria. Key points The modified TJA shows good to excellent intra- and inter-rater reliability. This test is useful for assessing repeated jump-landing technique. This test provides a user-friendly option for assessing high-risk movement patterns. PMID:28344460

  10. Bimanual passive movement: functional activation and inter-regional coupling.

    PubMed

    Macaluso, Emiliano; Cherubini, Andrea; Sabatini, Umberto

    2007-01-01

    The aim of this study was to investigate intra-regional activation and inter-regional connectivity during passive movement. During fMRI, a mechanic device was used to move the subject's index and middle fingers. We assessed four movement conditions (unimanual left/right, bimanual symmetric/asymmetric), plus Rest. A conventional intra-regional analysis identified the passive stimulation network, including motor cortex, primary and secondary somatosensory cortex, plus the cerebellum. The posterior (sensory) part of the sensory-motor activation around the central sulcus showed a significant modulation according to the symmetry of the bimanual movement, with greater activation for asymmetric compared to symmetric movements. A second set of fMRI analyses assessed condition-dependent changes of coupling between sensory-motor regions around the superior central sulcus and the rest of the brain. These analyses showed a high inter-regional covariation within the entire network activated by passive movement. However, the specific experimental conditions modulated these patterns of connectivity. Highest coupling was observed during the Rest condition, and the coupling between homologous sensory-motor regions around the left and right central sulcus was higher in bimanual than unimanual conditions. These findings demonstrate that passive movement can affect the connectivity within the sensory-motor network. We conclude that implicit detection of asymmetry during bimanual movement relies on associative somatosensory region in post-central areas, and that passive stimulation reduces the functional connectivity within the passive movement network. Our findings open the possibility to combine passive movement and inter-regional connectivity as a tool to investigate the functionality of the sensory-motor system in patients with very poor mobility.

  11. Integrated coding-aware intra-ONU scheduling for passive optical networks with inter-ONU traffic

    NASA Astrophysics Data System (ADS)

    Li, Yan; Dai, Shifang; Wu, Weiwei

    2016-12-01

    Recently, with the soaring of traffic among optical network units (ONUs), network coding (NC) is becoming an appealing technique for improving the performance of passive optical networks (PONs) with such inter-ONU traffic. However, in the existed NC-based PONs, NC can only be implemented by buffering inter-ONU traffic at the optical line terminal (OLT) to wait for the establishment of coding condition, such passive uncertain waiting severely limits the effect of NC technique. In this paper, we will study integrated coding-aware intra-ONU scheduling in which the scheduling of inter-ONU traffic within each ONU will be undertaken by the OLT to actively facilitate the forming of coding inter-ONU traffic based on the global inter-ONU traffic distribution, and then the performance of PONs with inter-ONU traffic can be significantly improved. We firstly design two report message patterns and an inter-ONU traffic transmission framework as the basis for the integrated coding-aware intra-ONU scheduling. Three specific scheduling strategies are then proposed for adapting diverse global inter-ONU traffic distributions. The effectiveness of the work is finally evaluated by both theoretical analysis and simulations.

  12. InterCon Travel Health: Case B

    ERIC Educational Resources Information Center

    Truman, Gregory E.; Pachamanova, Dessislava A.; Goldstein, Michael A.

    2010-01-01

    InterCon provides services to health insurers of foreign tourists who travel to the United States and Canada. Management wants to implement a new information system that will deal with several operational problems, but it is having difficulty securing the capital resources to fund the system's development. After an initial failure, the chief…

  13. "1970" Inter-Agency Health Meeting (Navajo).

    ERIC Educational Resources Information Center

    Arizona Commission of Indian Affairs, Phoenix.

    An inter-agency health meeting regarding health services for Navajo Indians is reported on in this document. The meeting, sponsored by the Arizona Commission of Indian Affairs, involved agencies such as the U.S. Public Health Service, Bureau of Indian Affairs, and the Navajo Tribe. Included in the proceedings are reports and remarks by…

  14. Inter-organisational response to disasters.

    PubMed

    Paturas, James L; Smith, Stewart R; Albanese, Joseph; Waite, Geraldine

    2016-01-01

    Inter-organisational communication failures during times of real-world disasters impede the collaborative response of agencies responsible for ensuring the public's health and safety. In the best of circumstances, communications across jurisdictional boundaries are ineffective. In times of crisis, when communities are grappling with the impact of a disaster, communications become critically important and more complex. Important factors for improving inter-organisational communications are critical thinking and problem-solving skills; inter-organisational relationships; as well as strategic, tactical and operational communications. Improving communication, critical thinking, problem-solving and decision-making requires a review of leadership skills. This discussion begins with an analysis of the existing disaster management research and moves to an examination of the importance of inter-organisational working relationships. Before a successful resolution of a disaster by multiple levels of first responders, the group of organisations must have a foundation of trust, collegiality, flexibility, expertise, openness, relational networking and effective communications. Leaders must also be prepared to improve leadership skills through continual development in each of these foundational areas.

  15. First Footing Inter-Faith Dialogue

    ERIC Educational Resources Information Center

    Luby, Antony

    2014-01-01

    This article examines an action research project on inter-faith dialogue within the sensitive context of Catholic pupils being taught Catholic religious education in state-funded secondary schools. Twenty pupils in S3 and S4 (Year 10 and Year 11) participated in a series of three paired conversations that focused primarily on science and religion,…

  16. Increasing security in inter-chip communication

    DOEpatents

    Edwards, Nathan J; Hamlet, Jason; Bauer, Todd; Helinski, Ryan

    2014-10-28

    An apparatus for increasing security in inter-chip communication includes a sending control module, a communication bus, and a receiving control module. The communication bus is coupled between the sending control module and the receiving control module. The sending control module operates to send data on the communication bus, disable the communication bus when threats are detected, or both.

  17. Quantification of annual carbon emissions from deforestation in South America

    NASA Astrophysics Data System (ADS)

    Song, X.; Huang, C.; Townshend, J. R.

    2013-12-01

    Tropical deforestation is the second largest source of carbon emissions to the atmosphere and also one of the most uncertain components of the global carbon cycle. Current estimates of carbon emissions from deforestation have errors as much as ×50%. This substantial uncertainty range stems in part from the uncertain estimate of changes in forest area as well as the lack of spatially explicit information on biomass density. Here we use multiple sources satellite data to quantify carbon emissions from deforestation in South America on a year-to-year basis from 2000 to 2010. We first use time-series multi-spectral images to map the spatial extent of forest loss. We then spatially match the area of deforestation with initial biomass density to quantify the committed carbon emissions from forest loss. Our results reveal that the five countries with the highest deforestation related emissions in South America are Brazil, Bolivia, Colombia, Argentina, and Chile. Their average annual emission rates are 218 TgC/yr, 23 TgC/yr, 16 TgC/yr, 14 TgC/yr and 11 TgC/yr, respectively. However, there are substantial inter-annual variations. Emissions in both Brazil and Argentina increased initially until 2005, and then declined. But Bolivia had a steady increasing trend in its emission over the 10 years. The coefficient of variation of annual emissions in these five countries ranges from 36% to 45%, indicating considerable inter-annual variations in carbon emissions from deforestation in these countries. These spatially explicit, multi-year emission estimates may be used as a baseline for REDD+ or other related emission mitigation efforts. The trends and large inter-annual variations in deforestation related emissions as revealed in this study should be considered in evaluating the performance of such efforts.

  18. Mountain hemlock growth responds to climatic variability at annual and decadal time scales

    USGS Publications Warehouse

    Peterson, D.W.; Peterson, D.L.

    2001-01-01

    Improved understanding of tree growth responses to climate is needed to model and predict forest ecosystem responses to current and future climatic variability. We used dendroecological methods to study the effects of climatic variability on radial growth of a subalpine conifer, mountain hemlock (Tsuga mertensiana). Tree-ring chronologies were developed for 31 sites, spanning the latitudinal and elevational ranges of mountain hemlock in the Pacific Northwest. Factor analysis was used to identify common patterns of inter-annual growth variability among the chronologies, and correlation and regression analyses were used to identify climatic factors associated with that variability. Factor analysis identified three common growth patterns, representing groups of sites with different climate-growth relationships. At high-elevation and midrange sites in Washington and northern Oregon, growth was negatively correlated with spring snowpack depth, and positively correlated with growth-year summer temperature and the winter Pacific Decadal Oscillation index (PDO). In southern Oregon, growth was negatively correlated with spring snowpack depth and previous summer temperature, and positively correlated with previous summer precipitation. At the low-elevation sites, growth was mostly insensitive to annual climatic variability but displayed sensitivity to decadal variability in the PDO opposite to that found at high-elevation sites. Mountain hemlock growth appears to be limited by late snowmelt, short growing seasons, and cool summer temperatures throughout much of its range in the Pacific Northwest. Earlier snowmelt, higher summer temperatures, and lower summer precipitation in southern Oregon produce conditions under which growth is limited by summer temperature and/or soil water availability. Increasing atmospheric CO2 concentrations could produce warmer temperatures and reduced snowpack depths in the next century. Such changes would likely increase mountain hemlock growth

  19. Extracting Inter-business Relationship from World Wide Web

    NASA Astrophysics Data System (ADS)

    Jin, Yingzi; Matsuo, Yutaka; Ishizuka, Mitsuru

    Social relation plays an important role in a real community. Interaction patterns reveal relations among actors (such as persons, groups, companies), which can be merged into valuable information as a network structure. In this paper, we propose a new approach to extract inter-business relationship from the Web. Extraction of relation between a pair of companies is realized by using a search engine and text processing. Since names of companies co-appear coincidentaly on the Web, we propose an advanced algorithm which is characterized by addition of keywords (or we call relation words) to a query. The relation words are obtained from either an annotated corpus or the Web. We show some examples and comprehensive evaluations on our approach.

  20. The annual cycles of phytoplankton biomass

    USGS Publications Warehouse

    Winder, M.; Cloern, J.E.

    2010-01-01

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

  1. Climate Impacts of Inter-hemispherically Asymmetric Radiative Forcing

    NASA Astrophysics Data System (ADS)

    Clark, S.; Ming, Y.; Held, I.

    2015-12-01

    It has been demonstrated in a number of modeling studies that the tropical circulation of the atmosphere is sensitive to changes in the inter-hemispheric energy budget. Examples of perturbations to the inter-hemispheric energy budget include changes in the Atlantic Meridional Overturning Circulation or spatially heterogeneous changes in the distribution of radiatively active aerosols. Whether aspects of the response of the circulation to the forcing are dependent on the forcing's latitudinal position is the subject of this study. Here we investigate the impact of the location of the asymmetric perturbation on the tropical circulation in the context of the gross moist stability framework using simulations from both an idealized moist model and a comprehensive GCM. In each model we artificially impose a negative radiative forcing between 0 and 30 degrees North and 30 and 90 degrees North, and discuss changes in precipitation patterns, meridional moist static energy transport, zonal mean mass streamfunction, and gross moist stability. In the idealized moist model, for a given asymmetric negative radiative forcing, the ITCZ shift is greater when the forcing is placed in the tropics instead of the extratropics. This difference in behavior can partially be explained by the fact that in the tropical case we decrease the net shortwave radiation at the equator, while in the extratropical case it is left unchanged. From Bischoff and Schneider (2014), decreasing the shortwave radiation at the equator increases the sensitivity of the ITCZ position to the moist static energy flux there. However we show that this increase in sensitivity cannot fully explain the differences seen between the idealized tropical and extratropical cases. In the full GCM, due to zonal asymmetries, the response in the tropical and extratropical cases is more complicated; an interesting result from those cases in the full GCM is that over the Sahel and Maritime Continent we see opposing precipitation

  2. 2010 Annual Report

    SciTech Connect

    2010-01-01

    This annual report includes: an overview of Western; approaches for future hydropower and transmission service; major achievements in FY 2010; FY 2010 customer Integrated Resource Planning, or IRP, survey; and financial data.

  3. Natural gas annual 1994

    SciTech Connect

    1995-11-17

    The Natural Gas Annual provides information on the supply and disposition of natural gas to a wide audience including industry, consumers, Federal and State agencies, and educational institutions. The 1994 data are presented in a sequence that follows natural gas (including supplemental supplies) from its production to its end use. This is followed by tables summarizing natural gas supply and disposition from 1990 to 1994 for each Census Division and each State. Annual historical data are shown at the national level.

  4. Natural gas annual 1995

    SciTech Connect

    1996-11-01

    The Natural Gas Annual provides information on the supply and disposition of natural gas to a wide audience including industry, consumers, Federal and State agencies, and educational institutions. The 1995 data are presented in a sequence that follows natural gas (including supplemental supplies) from its production to its end use. This is followed by tables summarizing natural gas supply and disposition from 1991 to 1995 for each Census Division and each State. Annual historical data are shown at the national level.

  5. TARDEC Annual Report 2010

    DTIC Science & Technology

    2011-06-15

    working on specific technologies, such as automotive capabilities, materials and software development. The benefits of these collaborations are two-fold...ANNUAL REPORT U.S. ARMY TANK AUTOMOTIVE RESEARCH, DEVELOPMENT AND ENGINEERING CENTER TWO THOUSAND TEN Report Documentation Page Form ApprovedOMB No...unlimited 13. SUPPLEMENTARY NOTES Tank- Automotive Research Development and Engineering Center (TARDEC) Fiscal Year (FY) 10 Annual Report 14. ABSTRACT

  6. Air-sea interactions and oceanic processes in the development of different Atlantic Niño patterns

    NASA Astrophysics Data System (ADS)

    Martin-Rey, Marta; Polo, Irene; Rodríguez-Fonseca, Belén; Lazar, Alban

    2016-04-01

    Atlantic Niño is the leading mode of inter-annual variability of the tropical Atlantic basin at inter-annual time scales. A recent study has put forward that two different Atlantic Niño patterns co-exist in the tropical Atlantic basin during negative phases of the Atlantic Multidecadal Oscillation. The leading mode, Basin-Wide (BW) Atlantic Niño is characterized by an anomalous warming extended along the whole tropical basin. The second mode, the Dipolar (D) Atlantic Niño presents positive Sea Surface Temperature (SST) anomalies in the central-eastern equatorial band, surrounded by negative ones in the North and South tropical Atlantic. The BW Atlantic Niño is associated with a weakening of both Azores and Sta Helena High, which reduces the tropical trades during previous autumn-winter. On the other hand, the D-Atlantic Niño is related to a strengthening of the Azores and a weakening of Helena High given rise to a meridional Sea Level Pressure (SLP) gradient that originates an intensification of the subtropical trades and anomalous westerlies along the equatorial band. This different wind forcing suggests that different oceanic processes could act in the development of the BW and D Atlantic Niño patterns. For this reason, an inter-annual simulation with the ocean NEMO model has been performed and the heat budget analysis has been analysed for each Atlantic Niño mode. The results suggest that the two Atlantic Nino configurations have different timing. The heat budget analysis reveals that BW Atlantic Nino SST pattern is due to anomalous air-sea heat fluxes in the south tropical and western equatorial Atlantic during the autumn-winter, while vertical processes are responsible of the warming in the central and eastern part of the basin during late-winter and spring. For the D-Atlantic Nino, the subtropical cooling is attributed to turbulent heat fluxes, the equatorial SST signal is mainly forced by vertical entrainment. The role of the oceanic waves in the

  7. Inter-arm blood pressure differences in young, healthy patients.

    PubMed

    Grossman, Alon; Prokupetz, Alex; Gordon, Barak; Morag-Koren, Nira; Grossman, Ehud

    2013-08-01

    The prevalence and magnitude of inter-arm BP difference (IAD) in young healthy patients is not well characterized. Flight academy applicants and designated aviators undergo annual evaluation that includes blood pressure (BP) measurement on both arms. All BP measurements performed from January 1, 2012, to April 30, 2012, were recorded and IAD was calculated. Results were compared between patients in whom BP was initially measured in the right arm (group 1), those in whom BP was initially measured in the left arm (group 2), and those in whom the arm in which BP was initially measured was not recorded (group 3). A total of 877 healthy patients had BP measured during the study period. In the entire group, mean systolic BP was the same in both arms. Absolute IAD was 5.6±5.5 mm Hg for systolic and 4.7±4.5 mm Hg for diastolic BP. IAD >10 mm Hg was recorded in 111 (12.6%) and 77 (8.8%) patients for systolic and diastolic BP, respectively. IAD was the same in the 3 groups and was unrelated to age, body mass index, and heart rate, but was related to systolic BP. IAD is common in young healthy patients, is not dependent on which arm was measured first, and unrelated to age, body mass index, and heart rate.

  8. Nutrient stoichiometry in winter wheat: Element concentration pattern reflects developmental stage and weather

    NASA Astrophysics Data System (ADS)

    Weih, M.; Pourazari, F.; Vico, G.

    2016-10-01

    At least 16 nutrient elements are required by plants for growth and survival, but the factors affecting element concentration and their temporal evolution are poorly understood. The objective was to investigate i) element concentration pattern in winter wheat as affected by crop developmental stage and weather, and ii) whether, in the short term, element stoichiometry reflects the type of preceding crop. We assessed the temporal trajectories of element concentration pattern (N, P, K, Ca, Mg, S, Mn, Fe, Cu, Na, Zn) across the life cycle (from seed to seed) of winter wheat field-grown in cool-temperate Sweden during two years with contrasting weather and when cultivated in monoculture or after different non-wheat preceding crops. We found strong influence of developmental stage on concentration pattern, with the greatest deviation from grain concentrations found in plants at the start of stem elongation in spring. Inter-annual differences in weather affected stoichiometry, but no evidence was found for a short-term preceding–crop effect on element stoichiometry. Winter wheat element stoichiometry is similar in actively growing plant tissues and seeds. Nitrogen exerts a strong influence on the concentration pattern for all elements. Three groups of elements with concentrations changing in concert were identified.

  9. Nutrient stoichiometry in winter wheat: Element concentration pattern reflects developmental stage and weather

    PubMed Central

    Weih, M.; Pourazari, F.; Vico, G.

    2016-01-01

    At least 16 nutrient elements are required by plants for growth and survival, but the factors affecting element concentration and their temporal evolution are poorly understood. The objective was to investigate i) element concentration pattern in winter wheat as affected by crop developmental stage and weather, and ii) whether, in the short term, element stoichiometry reflects the type of preceding crop. We assessed the temporal trajectories of element concentration pattern (N, P, K, Ca, Mg, S, Mn, Fe, Cu, Na, Zn) across the life cycle (from seed to seed) of winter wheat field-grown in cool-temperate Sweden during two years with contrasting weather and when cultivated in monoculture or after different non-wheat preceding crops. We found strong influence of developmental stage on concentration pattern, with the greatest deviation from grain concentrations found in plants at the start of stem elongation in spring. Inter-annual differences in weather affected stoichiometry, but no evidence was found for a short-term preceding–crop effect on element stoichiometry. Winter wheat element stoichiometry is similar in actively growing plant tissues and seeds. Nitrogen exerts a strong influence on the concentration pattern for all elements. Three groups of elements with concentrations changing in concert were identified. PMID:27775050

  10. Nutrient stoichiometry in winter wheat: Element concentration pattern reflects developmental stage and weather.

    PubMed

    Weih, M; Pourazari, F; Vico, G

    2016-10-24

    At least 16 nutrient elements are required by plants for growth and survival, but the factors affecting element concentration and their temporal evolution are poorly understood. The objective was to investigate i) element concentration pattern in winter wheat as affected by crop developmental stage and weather, and ii) whether, in the short term, element stoichiometry reflects the type of preceding crop. We assessed the temporal trajectories of element concentration pattern (N, P, K, Ca, Mg, S, Mn, Fe, Cu, Na, Zn) across the life cycle (from seed to seed) of winter wheat field-grown in cool-temperate Sweden during two years with contrasting weather and when cultivated in monoculture or after different non-wheat preceding crops. We found strong influence of developmental stage on concentration pattern, with the greatest deviation from grain concentrations found in plants at the start of stem elongation in spring. Inter-annual differences in weather affected stoichiometry, but no evidence was found for a short-term preceding-crop effect on element stoichiometry. Winter wheat element stoichiometry is similar in actively growing plant tissues and seeds. Nitrogen exerts a strong influence on the concentration pattern for all elements. Three groups of elements with concentrations changing in concert were identified.

  11. Volatiles in Inter-Specific Bacterial Interactions

    PubMed Central

    Tyc, Olaf; Zweers, Hans; de Boer, Wietse; Garbeva, Paolina

    2015-01-01

    The importance of volatile organic compounds for functioning of microbes is receiving increased research attention. However, to date very little is known on how inter-specific bacterial interactions effect volatiles production as most studies have been focused on volatiles produced by monocultures of well-described bacterial genera. In this study we aimed to understand how inter-specific bacterial interactions affect the composition, production and activity of volatiles. Four phylogenetically different bacterial species namely: Chryseobacterium, Dyella, Janthinobacterium, and Tsukamurella were selected. Earlier results had shown that pairwise combinations of these bacteria induced antimicrobial activity in agar media whereas this was not the case for monocultures. In the current study, we examined if these observations were also reflected by the production of antimicrobial volatiles. Thus, the identity and antimicrobial activity of volatiles produced by the bacteria were determined in monoculture as well in pairwise combinations. Antimicrobial activity of the volatiles was assessed against fungal, oomycetal, and bacterial model organisms. Our results revealed that inter-specific bacterial interactions affected volatiles blend composition. Fungi and oomycetes showed high sensitivity to bacterial volatiles whereas the effect of volatiles on bacteria varied between no effects, growth inhibition to growth promotion depending on the volatile blend composition. In total 35 volatile compounds were detected most of which were sulfur-containing compounds. Two commonly produced sulfur-containing volatile compounds (dimethyl disulfide and dimethyl trisulfide) were tested for their effect on three target bacteria. Here, we display the importance of inter-specific interactions on bacterial volatiles production and their antimicrobial activities. PMID:26733959

  12. Exposure to Inter-Parental Conflict Across 10 Years of Childhood: Data from the Longitudinal Study of Australian Children.

    PubMed

    Westrupp, Elizabeth M; Rose, Natalie; Nicholson, Jan M; Brown, Stephanie J

    2015-09-01

    Rates of child exposure to inter-parental conflict are high and appear to be increasing, with at least one million Australian children affected annually. To-date, there is no established prevalence for inter-parental conflict that includes the more common but less severe forms for young families in the wider Australian community. The current study aims were to examine the prevalence, persistence, and the individual, family and socio-economic context of inter-parental conflict. Data were from four waves of the Baby (n = 4,898) and Kindergarten (n = 4,182) cohorts of the Longitudinal Study of Australian Children. Verbal and physical inter-parental conflict was measured using the Argumentative Relationship Scale. More than 1 in 3 mothers (35-36%) reported any verbal and/or physical conflict. Prevalence of verbal conflict at each wave (10-13%) was higher than physical conflict (4-10%), with low co-occurrence (1-3%). Report of inter-parental conflict at one wave only was most common (19%); although 13% of mothers reported conflict at two waves; and 5-6% reported persistent conflict across three or more waves. Social disadvantage was consistently associated with report at one-wave only and persistent inter-parental conflict. Extrapolated to the Australian population, an estimated 1.9 million children are likely to be affected by inter-parental conflict within any 6 years of the early-to-middle childhood period. Establishing accurate prevalence and understanding the social context of the less severe but most common forms of inter-parental conflict will allow family and child support services to allocate finite resources more effectively and develop targeted interventions to promote children's positive development.

  13. Inter-annual variability of the epibiotic community on Pagurus bernhardus from Scotland

    NASA Astrophysics Data System (ADS)

    Fernandez-Leborans, Gregorio; Gabilondo, Regina

    2006-01-01

    Epibiont communities of Pagurus bernhardus and its inhabiting shell collected in the same month of two consecutive years near the Isle of Cumbrae (Scotland) were analyzed. The epibionts found were: (1) the protozoans Acineta, Conchacineta, Corynophrya, Zoothamnium, Cothurnia mobiusi, Cothurnia longipes, Chilodochona, Cryptacineta, Ephelota gemmipara and Ephelota plana; (2) the hydrozoans Leuckartiara, Clytia and Phialella; (3) the entoproct Barentsia; (4) the cirripeds Balanus balanus and Balanus crenatus; (5) the polychaetes Pomatoceros triqueter, Circeis amoricana paguri and Hydroides norvegica. Among these epibionts, a protozoan ( E. plana), two hydrozoans ( Leuckartiara, and Phialella), and the entoproct ( Barentsia) have not been described previously as epibionts on crustaceans. The protozoan, entoproct and hydrozoan epibiont species found on P. bernhardus represent the first mention of their presence on this hermit crab. The protozoan epibionts were found only on the crab, while the hydrozoan epibionts were observed on the shell and on the crab. The cirriped species were observed only on the external surface of the shell, and the polychaete species were observed on the external and internal surfaces of the shell, although Circeis was found only internally. An analysis of the distribution and density of each epibiont species on the anatomical units of the crab, as well as on the different shell areas were made. The comparison between the data of the two years showed differences with respect to the size of crabs, diversity of epibiont groups and density of epibionts. There was a significant difference between the two years with respect to the distribution of epibionts on the anatomical units of the crab, both in terms of density and biomass. The influence of some environmental parameters on these differences is considered.

  14. Inter-annual Variability of Mars Polar Processes as Observed by OMEGA/Mars Express

    NASA Astrophysics Data System (ADS)

    Langevin, Y.; Bibring, J.-P.; Plaut, J.; Vincendon, M.; Gondet, B.; Poulet, F.; Schmidt, F.

    2010-05-01

    Mars Express has now been operated successfully more than 6 earth years after orbit insertion in late 2003. Thanks to a much longer than expected lifetime of the cryocoolers, which still perform nominally, the coverage of polar regions by OMEGA now spans more than three full Mars years, from Ls 338°, M-year 26 to Ls 85°, M-year 30. Therefore, the South perennial cap (Ls 310° to Ls 0°), the South seasonal cap (Ls 0° to Ls 310°) and the North seasonal cap (Ls 170° to Ls 90°) have been observed over four successive Mars year while the North perennial cap (Ls 90° to Ls 170°) has been observed over three successive martian years. Due to the precession of the pericenter and of the orbit plane of the elliptical orbit of the satellite, the OMEGA imaging spectrometer on board this mission obtained data on polar regions at resolutions ranging from 300 m to 10 km over a wide range of Ls and local times [1, 2, 3, 4, 5]. This provides an excellent data set for comparing the evolution of seasonal caps and the spectral characteristics of the perennial caps over different Martian years. For both the perennial cap and the seasonal cap, the CO2 ice signatures dominate in the South while H2O ice signatures dominate in the North. The lag by a few weeks of the retreat of the seasonal caps observed by OMEGA between different Martian years is consistent with that of the "Crocus lines" derived from TES temperature data in 1999 - 2001 [6], with a possible link with dust storm activity in 2007. The spectral component which is not dominant (H2O in the South, CO2 in the North) shows overall consistency but significant year to year variability. CRISM/MRO observations at a much higher spatial resolution support these conclusions. 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]. As these regions show only weak albedo contrast, the observed variegation is likely linked with subsurface characteristics such as the high thermal inertia of underlying water ice rich layers at very shallow depths. This will be investigated by linking OMEGA observations with radar sounding of the subsurface by MARSIS/Mex [6] and SHARAD depending on the availability of data on regions of interest. [1] J-P. Bibring et al., Nature 428, p. 627 (2004) [2] Y. Langevin et al., Science 307, p. 1581 (2005) [3] Y. Langevin et al., Nature 442, p. 790 (2006) [4] Y. Langevin et al., J. Geophys. Res. 112, E08S12 (2007) [5] F. Schmidt et al., Icarus 200, p. 374 (2008) [5] T. Titus, H. H. Kieffer, abstract #2071, Lunar Planet. Science 33 (2002) [6] R. Jordan et al., Planet. Space Science 57, p. 1975 (2009)

  15. Digital Atlas and Evaluation of the Influence of Inter-Annual Variability on Climate Analyses

    DTIC Science & Technology

    2003-09-01

    Abstracts, Institute Nationale di Oceanografia e di Geofisica Sperimentale-OGS, Trieste, Italy 2001 р. 65 Unesco 1993: Manual of quality control procedures for validation of oceanographic data, IOC UNESCO, pp.436. 995

  16. Inter-annual variations and trends of the urban warming in Tehran

    NASA Astrophysics Data System (ADS)

    Alizadeh-Choobari, O.; Ghafarian, P.; Adibi, P.

    2016-03-01

    Urbanization is an extreme case of land-use change which amplifies in most cases the regional warming, and highly impacts a number of sensitive sectors, particularly human health. Using near-surface daily temperature records for a 63-yr period from 1951 to 2013, temperature changes over the urban city of Tehran were examined. Statistically significant warming trend of the order 0.37 °C/decade has been observed, leading to 2.3 °C rise over the entire 63-yr period, and the warming trend has been intensified in recent years. The observed warming in the urban city of Tehran has been more than triple the rate of change in the global average temperature, indicating that urbanization has had a significant warming effect. The nighttime warming (0.62 °C/decade) in the urban city of Tehran was found to be more than three times greater than the daytime warming (0.17 °C/decade), resulted in a decreasing trend in the diurnal temperature range (DTR; i.e. the difference between the daytime maximum and nighttime minimum temperatures). In a similar manner, a decreasing trend in the number of cold nights was identified, and the rate was more than twice as high as the rate of increase in the number of warm days. From a seasonal perspective, warming trends of the urban city of Tehran have been found to be nearly identical in winter and summer, with the rates of 0.35 °C/decade and 0.33 °C/decade, respectively. However, a seasonal cycle in the changes of the DTR was identified, with a stronger decrease rate in winter than summer because while the nighttime warming (which has been greater than the daytime warming) has not changed considerably from winter to summer, the daytime warming has been stronger in summer.

  17. Murres, capelin and ocean climate: Inter-annual associations across a decadal shift

    USGS Publications Warehouse

    Regular, P.M.; Shuhood, F.; Power, T.; Montevecchi, W.A.; Robertson, G.J.; Ballam, D.; Piatt, J.F.; Nakashima, B.

    2009-01-01

    To ensure energy demands for reproduction are met, it is essential that marine birds breed during periods of peak food availability. We examined associations of the breeding chronology of common murres (Uria aalge) with the timing of the inshore arrival of their primary prey, capelin (Mallotus villosus) from 1980 to 2006 across a period of pervasive change in the Northwest Atlantic ecosystem. We also assessed the influence of ocean temperature and the North Atlantic Oscillation (NAO; an index of winter climate and oceanography) on these interactions. We found a lagged linear relationship between variations in murre breeding chronology and the timing of capelin arrival in the previous year. On a decadal level, we found a non-linear threshold relationship between ocean temperature and the timing of capelin arrival and murre breeding. Centennially anomalous cold water temperatures in 1991 generated a marked shift in the timing of capelin spawning inshore and murre breeding, delaying both by more than 2 weeks. By the mid-1990s, ocean temperatures returned to pre-perturbation levels, whereas the temporal breeding responses of capelin and murres were delayed for a decade or more. Oceanographic conditions (temperature, NAO) were poor predictors of the timing of capelin arrival inshore in the current year compared to the previous one. Our findings suggest that knowledge of the timing of capelin availability in the previous year provides a robust cue for the long-lived murres, allowing them to achieve temporal overlap between breeding and peak capelin availability. ?? Springer Science+Business Media B.V. 2008.

  18. Investigatigating inter-/intra-annual variability of surface hydrology at northern high latitude from spaceborne measurements

    NASA Astrophysics Data System (ADS)

    Kang, K.; Duguay, C. R.

    2014-12-01

    Lakes encompass a large part of the surface cover in the northern boreal and tundra areas of northern Canada and are therefore a significant component of the terrestrial hydrological system. To understand the hydrologic cycle over subarctic and arctic landscapes, estimating surface parameters such as surface net radiation, soil moisture, and surface albedo is important. Although ground-based field measurements provide a good temporal resolution, these data provide a limited spatial representation and are often restricted to the summer period (from June to August), and few surface-based stations are located in high-latitude regions. In this respect, spaceborne remote sensing provides the means to monitor surface hydrology and to estimate components of the surface energy balance with reasonable spatial and temporal resolutions required for hydrological investigations, as well as for providing more spatially representative lake-relevant information than available from in situ measurements. The primary objective of this study is to quantify the sources of temporal and spatial variability in surface albedo over subarctic wetland from satellite derived albedo measurements in the Hudson Bay Lowlands near Churchill, Manitoba. The spatial variability in albedo within each land-cover type is investigated through optical satellite imagery from Landsat-5 Thematic Mapper, Landsat-7 Enhanced Thematic Mapper Plus, and Landsat-8 Operational Land Imager obtained in different seasons from spring into fall (April and October) over a 30-year period (1984-2013). These data allowed for an examination of the spatial variability of surface albedo under relatively dry and wet summer conditions (i.e. 1984, 1998 versus 1991, 2005). A detailed analysis of Landsat-derived surface albedo (ranging from 0.09 to 0.15) conducted in the Churchill region for August is inversely related to surface water fraction calculated from Landsat images. Preliminary analysis of surface albedo observed between July and August are 0.10 to 0.15, and vary due to differences in meteorological parameters such as rainfall, surface moisture and surface air temperature. Overall, spaceborne optical data are an invaluable source for investigating changes and variability in surface albedo in relation to surface hydrology over subarctic regions.

  19. Seasonal, Inter-annual and Long Term Trends in the Element Composition of Tropical Tree Rings

    NASA Astrophysics Data System (ADS)

    Verheyden, A.; Beeckman, H.; Andre, L.

    2008-12-01

    The inorganic composition of Rhizophora mucronata wood was studied on 11 stem discs collected from two mangrove forests in Kenya. The aim of this preliminary study was to assess if elements could be used as proxies of environmental and/or anthropogenic change. Earlywood and late wood were separated and analyzed on ICP-MS and ICP-OES. A remarkable synchronicity was found between ring width and Mg/Ca and Mn/Ca ratios, both of which have been used as soil pH proxies. However, there was also a negative correlation between Ca and ring width, indicating a dilution effect at higher growth rates. The essential elements P and K were significantly higher in fast growing plantation trees, suggesting that these elements might be useful as nutrient proxies in mangrove wood. A high correlation was found between Ca and Sr in the wood, indicating that probably no differentiation is made by the tree during incorporation of these elements in the wood. Since Sr/Ca of seawater is related to salinity, we suggest that the Sr/Ca in the wood could be used as a salinity proxy for tree species growing in brackish waters. Finally, a high-resolution study was also conducted using LA-ICP-MS, which revealed a high spatial variability within one ring. This high variability was the result of different concentrations in each wood cell type analyzed. The heavy metals (Cu, Zn, Pb and Cr), as well as Ba, had highest concentrations in the fibers and lowest in the vessels. On the other hand, B, Mn, Ca, P, and Sr were highest in the rays and vessels and lowest in the fibers, while Mg was the highest in the rays, but lowest in the vessels. The implications of these results for the use of trace elements to delimit chemical ring boundaries in tropical trees will be discussed.

  20. Inter-comparison of subglacial hydrological models

    NASA Astrophysics Data System (ADS)

    de Fleurian, Basile; Werder, Mauro

    2016-04-01

    The recent emergence of a number of subglacial hydrological models allows us to obtain theoretical insights on basal processes; for instance on the coupling between water pressure and the sliding of glaciers. In ice-flow models, it is relatively clear what the simulated physics ought to be. Conversely, the physical processes incorporated into subglacial hydrology models are diverse as it is yet unclear which ones are of relevance for a particular setting. An inter-comparison of hydrology models will therefore need a somewhat different approach to the one used in the many ice-flow model inter-comparisons (EISMINT, ISMIP, etc.). Here, we present a set of experiments that will allow the comparison of the behavior of different hydrology models. The design of the benchmark aims at allowing the participation of a wide range of models based on different physical approaches. We aim at evaluating the models with a focus on the effective pressure which has the most impact on the dynamics of glaciers. The aim of this inter-comparison is to provide modellers with the necessary data to make an informed decision on which subglacial hydrology model to use for a particular study.

  1. Transient inter-cellular polymeric linker.

    PubMed

    Ong, Siew-Min; He, Lijuan; Thuy Linh, Nguyen Thi; Tee, Yee-Han; Arooz, Talha; Tang, Guping; Tan, Choon-Hong; Yu, Hanry

    2007-09-01

    Three-dimensional (3D) tissue-engineered constructs with bio-mimicry cell-cell and cell-matrix interactions are useful in regenerative medicine. In cell-dense and matrix-poor tissues of the internal organs, cells support one another via cell-cell interactions, supplemented by small amount of the extra-cellular matrices (ECM) secreted by the cells. Here we connect HepG2 cells directly but transiently with inter-cellular polymeric linker to facilitate cell-cell interaction and aggregation. The linker consists of a non-toxic low molecular-weight polyethyleneimine (PEI) backbone conjugated with multiple hydrazide groups that can aggregate cells within 30 min by reacting with the aldehyde handles on the chemically modified cell-surface glycoproteins. The cells in the cellular aggregates proliferated; and maintained the cortical actin distribution of the 3D cell morphology while non-aggregated cells died over 7 days of suspension culture. The aggregates lost distinguishable cell-cell boundaries within 3 days; and the ECM fibers became visible around cells from day 3 onwards while the inter-cellular polymeric linker disappeared from the cell surfaces over time. The transient inter-cellular polymeric linker can be useful for forming 3D cellular and tissue constructs without bulk biomaterials or extensive network of engineered ECM for various applications.

  2. [Bipolar disorder: inter-episode symptoms].

    PubMed

    Azorin, J-M

    2012-12-01

    The importance of inter-episode symptoms in bipolar disorder can be traced back to the middle of the 19th century, at a time when the two fathers of the concept in France, Falret and Baillarger were opposed on the issue as to whether the presence of free intervals between the episodes had to be part or not of the disease's definition. Modern studies have reported rates between 50 and 68% for those symptoms which refer to subsyndromal manifestations present between affective episodes but that do not meet the required criteria for episodes definition. These manifestations comprise residual symptoms, prodromes, axis I comorbid psychiatric disorders, side effects of treatment, temperamental features, and comorbidity with personality disorders. Inter- episodes symptoms represent a risk factor for the occurrence of relapses and recurrences and are usually associated with impairments in functioning in almost all domains of psychosocial and family life. As they are easy to miss, it is important in clinical practice, to draw the attention of clinicians, patients and relatives to the role they have in the course of the illness. As far as their management, it may be crucial to achieve a full remission of the episodes, using adequate dosages of psychotropic drugs. Residual symptoms, prodromes as well as other inter-episode symptoms may respond to strategies based on cognitive-behaviour therapy, and/or psychoeducation.

  3. Multivariate models of inter-subject anatomical variability

    PubMed Central

    Ashburner, John; Klöppel, Stefan

    2011-01-01

    This paper presents a very selective review of some of the approaches for multivariate modelling of inter-subject variability among brain images. It focusses on applying probabilistic kernel-based pattern recognition approaches to pre-processed anatomical MRI, with the aim of most accurately modelling the difference between populations of subjects. Some of the principles underlying the pattern recognition approaches of Gaussian process classification and regression are briefly described, although the reader is advised to look elsewhere for full implementational details. Kernel pattern recognition methods require matrices that encode the degree of similarity between the images of each pair of subjects. This review focusses on similarity measures derived from the relative shapes of the subjects' brains. Pre-processing is viewed as generative modelling of anatomical variability, and there is a special emphasis on the diffeomorphic image registration framework, which provides a very parsimonious representation of relative shapes. Although the review is largely methodological, excessive mathematical notation is avoided as far as possible, as the paper attempts to convey a more intuitive understanding of various concepts. The paper should be of interest to readers wishing to apply pattern recognition methods to MRI data, with the aim of clinical diagnosis or biomarker development. It also tries to explain that the best models are those that most accurately predict, so similar approaches should also be relevant to basic science. Knowledge of some basic linear algebra and probability theory should make the review easier to follow, although it may still have something to offer to those readers whose mathematics may be more limited. PMID:20347998

  4. Late 18th to early 19th century sea-level history and inter-seismic behavior along the western Myanmar plate boundary belt recorded by coral microatolls

    NASA Astrophysics Data System (ADS)

    Liu, Sze-Chieh; Shyu, J. Bruce H.

    2016-04-01

    Along the western Myanmar plate boundary belt, the Indian-Australian plate is subducting obliquely beneath the Burma micro-plate at a rate of about 23 mm/yr. Although information about the 1762 Arakan earthquake, the only major historical event occurred along this plate boundary belt, has been delineated recently from uplifted coastal features, constraints on the inter-seismic behavior of this belt is still very limited, due to the lack of high resolution instrumental records in the area. Therefore, we utilized coral microatolls to analyze relative sea level history, in order to obtain potential information of land-level change along the western coast of Myanmar. Our sample was collected from northwestern Ramree Island, approximately 80 km away from the trench. Previous studies suggest that the coral was uplifted and killed during a local earthquake event in 1848, and recorded relative sea level history of ~80 years prior to that event. Since the highest level of survival (HLS) of coral microatolls is constrained within a few centimeters of the lowest tide level of the area, the patterns of annual growth bands of the coral microatoll in x-radiograph provide us yearly record of relative sea level, and we used U-Th dating technique to constrain the age of the coral. Our results show that this coral microatoll may have recorded the inter-seismic subsidence of northwestern Ramree Island, punctuated by several climatic events that produced die-down records of the coral growth bands. We hope the data obtained from this coral microatoll, combined with previously reported information of the area, will enable us to further understand the seismic behavior of this major plate boundary belt.

  5. Large animal grazing and temporal patterns in ecosystem services

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The shortgrass steppe ecosystem has a long evolutionary history of large animal grazing by bison, which were replaced by domesticated livestock in the mid 1800s. In addition, this ecosystem is characterized by a semi-arid environment with low annual precipitation amounts, but high inter- and intra-a...

  6. 47 CFR 25.279 - Inter-satellite service.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Technical Operations § 25.279 Inter-satellite service. (a) Any satellite communicating with other space stations may use frequencies in the inter-satellite service as indicated in § 2.106 of this chapter....

  7. Research and Clinical Center for Child Development Annual Report, 1995-1996, No. 19.

    ERIC Educational Resources Information Center

    Wakai, Kunio, Ed.; Chen, Shing-Jen, Ed.; Furutsuka, Takashi, Ed.; Shirotani, Yukari, Ed.

    This annual report discusses several topics related to the work of the Research and Clinical Center for Child Development at Hokkaido University in Japan. The articles are: (1) "Heart to Heart (Inter "Jo") Resonance: Taking Japanese Concept of Intersubjectivity Out of Everyday Life" (Shigeru Nakano); (2) "Intersubjectivity…

  8. StreamNet; 1999 Annual Report.

    SciTech Connect

    Columbia River Inter-Tribal Fish Commission

    2000-01-01

    This report was funded by the Bonneville Power Administration (BPA), US Department of Energy, as part of BPA's program to protect, mitigate, and enhance fish and wildlife affected by the development and operation of hydroelectric facilities on the Columbia River and its tributaries. The views of this report are the author's and do not necessarily represent the views of BPA. This annual report covers progress made by: Columbia River Inter-Tribal Fish Commission Idaho; Department of Fish and Game; Montana Department of Fish, Wildlife and Parks; Oregon Department of Fish and Wildlife; Pacific States Marine Fisheries Commission; Shoshone-Bannock Tribes; US Fish and Wildlife Service; Washington Department of Fish and Wildlife; and FY1999 StreamNet Quickplan.

  9. Spatiotemporal patterns of evapotranspiration along the North American east coast as influenced by multiple environmental changes

    DOE PAGES

    Yang, Qichun; Tian, Hanqin; Li, Xia; ...

    2014-08-08

    The North American east coast has experienced significant land-use and climate changes since the beginning of the 20th century. In this study, using the Dynamic Land Ecosystem Model 2.0 driven by time-series input data of land use, climate and atmospheric CO2, we examined how these driving forces have affected the spatiotemporal trends and variability of evapotranspiration (ET) in this region during 1901–2008. Annual ET in the North American east coast during this period was 648.3 ± 38.6 mm/year and demonstrated an increasing trend. Factorial model simulations indicated that climate variability explained 76% of the inter-annual ET variability. Although land-use changemore » only explained 16% of the ET temporal variability, afforestation induced the upward trend of ET and increased annual ET by 12.8 mm/year. Elevated atmospheric CO2 reduced annual ET by 0.84 mm, and its potential impacts under future atmospheric CO2 levels could be much larger than estimates for the historical 1901–2008 period. Climate change determined the spatial pattern of ET changes across the entire study area, whereas land-use changes dramatically affected ET in watersheds with significant land conversions. In spite of the multiple benefits from afforestation, its impacts on water resources should be considered in future land-use policy making. As a result, elevated ET may also affect fresh water availability for the increasing social and economic water demands.« less

  10. Spatiotemporal patterns of evapotranspiration along the North American east coast as influenced by multiple environmental changes

    SciTech Connect

    Yang, Qichun; Tian, Hanqin; Li, Xia; Tao, Bo; Ren, Wei; Chen, Guangsheng; Lu, Chaoqun; Yang, Jia; Pan, Shufen; Banger, Kamaljit; Zhang, Bowen

    2014-08-08

    The North American east coast has experienced significant land-use and climate changes since the beginning of the 20th century. In this study, using the Dynamic Land Ecosystem Model 2.0 driven by time-series input data of land use, climate and atmospheric CO2, we examined how these driving forces have affected the spatiotemporal trends and variability of evapotranspiration (ET) in this region during 1901–2008. Annual ET in the North American east coast during this period was 648.3 ± 38.6 mm/year and demonstrated an increasing trend. Factorial model simulations indicated that climate variability explained 76% of the inter-annual ET variability. Although land-use change only explained 16% of the ET temporal variability, afforestation induced the upward trend of ET and increased annual ET by 12.8 mm/year. Elevated atmospheric CO2 reduced annual ET by 0.84 mm, and its potential impacts under future atmospheric CO2 levels could be much larger than estimates for the historical 1901–2008 period. Climate change determined the spatial pattern of ET changes across the entire study area, whereas land-use changes dramatically affected ET in watersheds with significant land conversions. In spite of the multiple benefits from afforestation, its impacts on water resources should be considered in future land-use policy making. As a result, elevated ET may also affect fresh water availability for the increasing social and economic water demands.

  11. The annual temperature cycle in shelf seas

    NASA Astrophysics Data System (ADS)

    Prandle, D.; Lane, A.

    1995-05-01

    A generalized theory is developed to describe the annual temperature cycle in shelf seas. A sinusoidal approximation to the annual solar heating component, S, is assumed and the surface loss term is expressed as a constant k times the air-sea temperature difference ( T a - T s). In well-mixed seas, analytical solutions show that in shallow water the sea temperature follows closely that of the ambient air temperature with limited separate effect of solar heating. Conversely in deep water, the sea surface temperature variations will be reduced relative to that of the ambient air. Providing such deep water remains mixed vertically, the annual variation will be inversely proportional to depth and maximum temperatures will occur up to 3 months after the maximum of solar heating. Generally, the magnitude of the inter-annual variability of sea surface temperatures will be less than corresponding variability in either the effective solar heating, S, (reduced by cloud cover) or the surface loss coefficient, k, (increased by stronger winds). The annual-mean sea temperature will exceed the annual mean air temperature by the annual mean of S divided by k. The above results can be extended to partially-stratified waters so long as autumnal overturning does not occur. For such conditions, an analytical expression is derived for the annual cycle of depth-varying temperatures for mixing associated with a vertical eddy dispersion coefficient E (constant in depth and time). The time taken for solar heating to be equalized throughout the water depth, D, is given by Tv = D 2/E , for a tidal current amplitude of 20 cm s -1. Tv ranges from 3.6 days for D = 50m to231days forD = 400m. To simulate the effect of gravitational instability that produces autumnal overturning, a numerical model is used that represents the effect of daily surface heat exchanges by a series expansion. Results from this model are used to indicate the effects of stratification over a range of values of both depth

  12. Stationarity of the inter-event power-law distributions

    PubMed Central

    2017-01-01

    A number of human activities exhibit a bursty pattern, namely periods of very high activity that are followed by rest periods. Records of these processes generate time series of events whose inter-event times follow a probability distribution that displays a fat tail. The grounds for such phenomenon are not yet clearly understood. In the present work we use the freely available Wikipedia’s editing records to unravel some features of this phenomenon. We show that even though the probability to start editing is conditioned by the circadian 24 hour cycle, the conditional probability for the time interval between successive edits at a given time of the day is independent from the latter. We confirm our findings with the activity of posting on the social network Twitter. Our results suggest that there is an intrinsic humankind scheduling pattern: after overcoming the encumbrance of starting an activity, there is a robust distribution of new related actions, which does not depend on the time of day at which the activity started. PMID:28346480

  13. Gynecologic Cancer InterGroup (GCIG) consensus review for cervical adenocarcinoma.

    PubMed

    Fujiwara, Hiroyuki; Yokota, Harushige; Monk, Bradley; Treilleux, Isabelle; Devouassoux-Shisheboran, Mojgan; Davis, Alison; Kim, Jae-Weon; Mahner, Sven; Stany, Michael; Pignata, Sandro; Ray-Coquard, Isabelle; Fujiwara, Keiichi

    2014-11-01

    Cervical adenocarcinoma is known to be less common than squamous cell carcinoma of the cervix comprising approximately 25% of all cervical carcinomas. Differences in associated human papillomavirus types, patterns of spread, and prognosis call for treatments that are not always like those for squamous cancers. In this review, we report a consensus developed by the Gynecologic Cancer InterGroup surrounding cervical adenocarcinoma for epidemiology, pathology, treatment, and unanswered questions. Prospective clinical trials are needed to help develop treatment guidelines.

  14. Characterization of Regional Influenza Seasonality Patterns in China and Implications for Vaccination Strategies: Spatio-Temporal Modeling of Surveillance Data

    PubMed Central

    Yu, Hongjie; Alonso, Wladimir J.; Feng, Luzhao; Tan, Yi; Shu, Yuelong; Yang, Weizhong; Viboud, Cécile

    2013-01-01

    Background The complexity of influenza seasonal patterns in the inter-tropical zone impedes the establishment of effective routine immunization programs. China is a climatologically and economically diverse country, which has yet to establish a national influenza vaccination program. Here we characterize the diversity of influenza seasonality in China and make recommendations to guide future vaccination programs. Methods and Findings We compiled weekly reports of laboratory-confirmed influenza A and B infections from sentinel hospitals in cities representing 30 Chinese provinces, 2005–2011, and data on population demographics, mobility patterns, socio-economic, and climate factors. We applied linear regression models with harmonic terms to estimate influenza seasonal characteristics, including the amplitude of annual and semi-annual periodicities, their ratio, and peak timing. Hierarchical Bayesian modeling and hierarchical clustering were used to identify predictors of influenza seasonal characteristics and define epidemiologically-relevant regions. The annual periodicity of influenza A epidemics increased with latitude (mean amplitude of annual cycle standardized by mean incidence, 140% [95% CI 128%–151%] in the north versus 37% [95% CI 27%–47%] in the south, p<0.0001). Epidemics peaked in January–February in Northern China (latitude ≥33°N) and April–June in southernmost regions (latitude <27°N). Provinces at intermediate latitudes experienced dominant semi-annual influenza A periodicity with peaks in January–February and June–August (periodicity ratio >0.6 in provinces located within 27.4°N–31.3°N, slope of latitudinal gradient with latitude −0.016 [95% CI −0.025 to −0.008], p<0.001). In contrast, influenza B activity predominated in colder months throughout most of China. Climate factors were the strongest predictors of influenza seasonality, including minimum temperature, hours of sunshine, and maximum rainfall. Our main study

  15. International energy annual 1996

    SciTech Connect

    1998-02-01

    The International Energy Annual presents an overview of key international energy trends for production, consumption, imports, and exports of primary energy commodities in over 220 countries, dependencies, and areas of special sovereignty. Also included are population and gross domestic product data, as well as prices for crude oil and petroleum products in selected countries. Renewable energy reported in the International Energy Annual includes hydroelectric power, geothermal, solar, and wind electric power, biofuels energy for the US, and biofuels electric power for Brazil. New in the 1996 edition are estimates of carbon dioxide emissions from the consumption of petroleum and coal, and the consumption and flaring of natural gas. 72 tabs.

  16. Natural gas annual 1997

    SciTech Connect

    1998-10-01

    The Natural Gas Annual provides information on the supply and disposition of natural gas to a wide audience including industry, consumers, Federal and State agencies, and educational institutions. The 1997 data are presented in a sequence that follows natural gas (including supplemental supplies) from its production to its end use. This is followed by tables summarizing natural gas supply and disposition from 1993 to 1997 for each Census Division and each State. Annual historical data are shown at the national level. 27 figs., 109 tabs.

  17. Overview of the InterGroup protocols

    SciTech Connect

    Berket, Karlo; Agarwal, Deborah A.; Melliar-Smith, P. Michael; Moser, Louise E.

    2001-03-01

    Existing reliable ordered group communication protocols have been developed for local-area networks and do not, in general, scale well to large numbers of nodes and wide-area networks. The InterGroup suite of protocols is a scalable group communication system that introduces a novel approach to handling group membership, and supports a receiver-oriented selection of service. The protocols are intended for a wide-area network, with a large number of nodes, that has highly variable delays and a high message loss rate, such as the Internet. The levels of the message delivery service range from unreliable unordered to reliable group timestamp ordered.

  18. Application of a reduced area electrical test pattern to precise pattern registration measurements

    NASA Astrophysics Data System (ADS)

    Rominger, James P.

    1991-03-01

    A new reduced area electrically probed registration measurement pattern is described. The pattern is compatible with the Prometrix data acquisition and analysis system, and offers advantages over standard patterns in terms of patten area and versatility of use. The results of the application of the pattern to the measurement of reticle and stepper overlay are presented. With careful analysis of the data, inter- and intrafield reticle overlay errors are determined. Horizontal and vertical measurements of pattern placement within a single field and between fields showed an accuracy of greater than 67 nm and a repeatability of better than 14 nm (3 sigma).

  19. NERSC Annual Report 2005

    SciTech Connect

    Hules , John

    2006-07-31

    The National Energy Research Scientific Computing Center (NERSC) is the premier computational resource for scientific research funded by the DOE Office of Science. The Annual Report includes summaries of recent significant and representative computational science projects conducted on NERSC systems as well as information about NERSC's current and planned systems and services.

  20. Annual Research Briefs - 1996

    NASA Technical Reports Server (NTRS)

    1996-01-01

    This report contains the 1996 annual progress reports of the research fellows and students supported by the Center for Turbulence Research. Last year, CTR hosted twelve resident Postdoctoral Fellows, three Research Associates, four Senior Research Fellows, and supported one doctoral student and ten short term visitors.

  1. Annual Coal Distribution

    EIA Publications

    2016-01-01

    The Annual Coal Distribution Report (ACDR) provides detailed information on domestic coal distribution by origin state, destination state, consumer category, and method of transportation. Also provided is a summary of foreign coal distribution by coal-producing state. All data for the report year are final and this report supersedes all data in the quarterly distribution reports.

  2. Uranium industry annual 1998

    SciTech Connect

    1999-04-22

    The Uranium Industry Annual 1998 (UIA 1998) provides current statistical data on the US uranium industry`s activities relating to uranium raw materials and uranium marketing. It contains data for the period 1989 through 2008 as collected on the Form EIA-858, ``Uranium Industry Annual Survey.`` Data provides a comprehensive statistical characterization of the industry`s activities for the survey year and also include some information about industry`s plans and commitments for the near-term future. Data on uranium raw materials activities for 1989 through 1998, including exploration activities and expenditures, EIA-estimated reserves, mine production of uranium, production of uranium concentrate, and industry employment, are presented in Chapter 1. Data on uranium marketing activities for 1994 through 2008, including purchases of uranium and enrichment services, enrichment feed deliveries, uranium fuel assemblies, filled and unfilled market requirements, and uranium inventories, are shown in Chapter 2. The methodology used in the 1998 survey, including data edit and analysis, is described in Appendix A. The methodologies for estimation of resources and reserves are described in Appendix B. A list of respondents to the ``Uranium Industry Annual Survey`` is provided in Appendix C. The Form EIA-858 ``Uranium Industry Annual Survey`` is shown in Appendix D. For the readers convenience, metric versions of selected tables from Chapters 1 and 2 are presented in Appendix E along with the standard conversion factors used. A glossary of technical terms is at the end of the report. 24 figs., 56 tabs.

  3. Folklife Annual, 1987.

    ERIC Educational Resources Information Center

    Jabbour, Alan, Ed.; Hardin, James, Ed.

    This annual publication is intended to promote the documentation and study of the folklife of the United States, to share the traditions, values, and activities of U.S. folk culture, and to serve as a national forum for the discussion of ideas and issues in folklore and folklife. The articles in this collection are: (1) "Eating in the Belly…

  4. NRCC annual report, 1979

    SciTech Connect

    Not Available

    1980-11-01

    This annual report of the National Research for Computation in Chemistry (NRCC) Division describes the program of research workshops, software development, and scientific research of the Division in 1979. This year marked the first full calendar year of activity of the Division. Initial staffing in the core scientific areas was completed by the addition of a crystallographer.

  5. International Energy Annual, 1992

    SciTech Connect

    Not Available

    1994-01-14

    This report is prepared annually and presents the latest information and trends on world energy production and consumption for petroleum, natural gas, coal, and electricity. Trade and reserves are shown for petroleum, natural gas, and coal. Prices are included for selected petroleum products. Production and consumption data are reported in standard units as well as British thermal units (Btu) and joules.

  6. 2010 AAUW Annual Report

    ERIC Educational Resources Information Center

    American Association of University Women, 2010

    2010-01-01

    This report highlights some of the outstanding accomplishments of AAUW (American Association of University Women) for fiscal year 2010. This year's annual report also features stories of remarkable women who are leading the charge to break through barriers and ensure that all women have a fair chance. Sharon is working to reduce the pay gap…

  7. NERSC Annual Report 2002

    SciTech Connect

    Hules, John

    2003-01-31

    The National Energy Research Scientific Computing Center (NERSC) is the primary computational resource for scientific research funded by the DOE Office of Science. The Annual Report for FY2002 includes a summary of recent computational science conducted on NERSC systems (with abstracts of significant and representative projects), and information about NERSC's current and planned systems and service

  8. ASE Annual Conference 2010

    ERIC Educational Resources Information Center

    McCune, Roger

    2010-01-01

    In this article, the author describes the ASE Annual Conference 2010 which was held at Nottingham after a gap of 22 years. As always, the main conference was preceded by International Day, an important event for science educators from across the world. There were two strands to the programme: (1) "What works for me?"--sharing new ideas…

  9. UNICEF Annual Report. 1984.

    ERIC Educational Resources Information Center

    United Nations Children's Fund, New York, NY.

    This annual report reviews the work UNICEF has been doing to help transform the "Child Survival Revolution" from a dream into a reality. Discussion focuses primarily on child health and nutrition and other basic services for children. Throughout, the review is supplemented with profiles of program initiatives made to improve the…

  10. NERSC Annual Report 2004

    SciTech Connect

    Hules, John; Bashor, Jon; Yarris, Lynn; McCullough, Julie; Preuss, Paul; Bethel, Wes

    2005-04-15

    The National Energy Research Scientific Computing Center (NERSC) is the premier computational resource for scientific research funded by the DOE Office of Science. The Annual Report includes summaries of recent significant and representative computational science projects conducted on NERSC systems as well as information about NERSC's current and planned systems and services.

  11. Annual Conference Abstracts

    ERIC Educational Resources Information Center

    Journal of Engineering Education, 1972

    1972-01-01

    Includes abstracts of papers presented at the 80th Annual Conference of the American Society for Engineering Education. The broad areas include aerospace, affiliate and associate member council, agricultural engineering, biomedical engineering, continuing engineering studies, chemical engineering, civil engineering, computers, cooperative…

  12. TARDEC Annual Report 2011

    DTIC Science & Technology

    2012-01-01

    TARDEC ANNUAL REPORT 2011 35 Anniston Army Depot provides new Assault Breacher Vehicles for the U.S. Marine Corps. TARDEC’s liaison exchange...program has included Anniston Army Depot and increased communication and enabled support between the organizations. (U.S. Army photo.) DiMinishing

  13. Magnetic Resonance Annual, 1985

    SciTech Connect

    Kressel, H.Y.

    1985-01-01

    The inaugural volume of Magnetic Resonance Annual includes reviews of MRI of the posterior fossa, cerebral neoplasms, and the cardiovascular and genitourinary systems. A chapter on contrast materials outlines the mechanisms of paramagnetic contrast enhancement and highlights several promising contrast agents.

  14. UNICEF Annual Report, 1993.

    ERIC Educational Resources Information Center

    United Nations Children's Fund, New York, NY.

    This annual report for the United Nations Children's Fund (UNICEF) details the programs and services provided by this organization in 1992-93. Following an introduction by UNICEF's executive director, the report briefly reviews UNICEF activities for 1992, then describes specific projects in the following areas: (1) child survival and development;…

  15. UNICEF Annual Report 1983.

    ERIC Educational Resources Information Center

    United Nations Children's Fund, New York, NY.

    In introducing this annual report, the executive director of UNICEF delineates the four techniques for primary health care and basic services reported in the publication "State of the World's Children, 1982-1983." The ensuing review of UNICEF's activities illustrates highlights of the year's program cooperation, including trends and key…

  16. Annual Review 1994.

    ERIC Educational Resources Information Center

    Bernard Van Leer Foundation, The Hague (Netherlands).

    The report provides an annual report and financial review for 1994 of the Bernard van Leer Foundation, a private institution that was created for broad humanitarian purposes in 1949, and shows the varied aspects of the foundation's activities in the project field. In addition, it includes a number of feature articles which highlight specific…

  17. Annual Review 1995.

    ERIC Educational Resources Information Center

    Bernard Van Leer Foundation, The Hague (Netherlands).

    This document provides an annual report and financial review for 1995 of the Bernard van Leer Foundation, a private institution created in 1949 for broad humanitarian purposes. The report includes feature articles highlighting specific aspects of the year's activities: (1) "Growing Up in France: Parental Creches"; (2) "Changing the…

  18. Annual Conference Abstracts

    ERIC Educational Resources Information Center

    Engineering Education, 1976

    1976-01-01

    Presents the abstracts of 158 papers presented at the American Society for Engineering Education's annual conference at Knoxville, Tennessee, June 14-17, 1976. Included are engineering topics covering education, aerospace, agriculture, biomedicine, chemistry, computers, electricity, acoustics, environment, mechanics, and women. (SL)

  19. Annual Energy Outlook

    EIA Publications

    2017-01-01

    The Annual Energy Outlook provides modeled projections of domestic energy markets through 2050, and includes cases with different assumptions of macroeconomic growth, world oil prices, technological progress, and energy policies. With strong domestic production and relatively flat demand, the United States becomes a net energy exporter over the projection period in most cases.

  20. NUFFIC Annual Report, 1977.

    ERIC Educational Resources Information Center

    Netherlands Universities Foundation for International Co-operation, The Hague.

    The 1977 annual report of the Netherlands Universities Foundation for International Cooperation (NUFFIC) considers the following topics: major developments in work and policy; relationships NUFFIC has with other organizations; University Development Cooperation; developments in international education; the functioning of the Consultative Structure…

  1. Carolinas Communication Annual, 1998.

    ERIC Educational Resources Information Center

    McLennan, David B.

    1998-01-01

    This 1998 issue of "Carolinas Communication Annual" contains the following articles: "Give Me That Old Time Religion?: A Study of Religious Themes in the Rhetoric of the Ku Klux Klan" (John S. Seiter); "The Three Stooges versus the Third Reich" (Roy Schwartzman); "Interdisciplinary Team Teaching: Implementing…

  2. TACSCE Research Annual 1991.

    ERIC Educational Resources Information Center

    Lesko, Silvia Jo

    1991-01-01

    This annual contains the paper that won the 1991 President's Award of the Texas Association for Community Service and Continuing Education (TACSCE) as well as the runner-up paper and other articles. An editorial, "Learning to Crawl" (Silvia Lesko), focuses on the editor's "discovery" of the adult learner. "Ethics and…

  3. UNICEF Annual Report, 1994.

    ERIC Educational Resources Information Center

    United Nations Children's Fund, New York, NY.

    This annual report for the United Nations Children's Fund (UNICEF) describes the programs and services provided by this organization in 1993. Following an introduction by UNICEF's executive director, the report reviews regional developments in Sub-Saharan Africa, the Middle East and North Africa, East Asia and the Pacific, South Asia, Latin…

  4. Inter-esterified palm products as alternatives to hydrogenation.

    PubMed

    Idris, Nor Aini; Dian, Noor Lida Habi Mat

    2005-01-01

    Inter-esterification is one of the processes used to modify the physico-chemical characteristics of oils and fats. Inter-esterification is an acyl-rearrangement reaction on the glycerol molecule. On the other hand, hydrogenation involves addition of hydrogen to the double bonds of unsaturated fatty acids. Due to health implications of trans fatty acids, which are formed during hydrogenation, the industry needs to find alternatives to hydrogenated fats. This paper discusses some applications of inter-esterified fats, with particular reference to inter-esterified palm products, as alternatives to hydrogenation. Some physico-chemical properties of inter-esterified fats used in shortenings are discussed. With inter-esterification, more palm stearin can be incorporated in vanaspati. For confectionary fats and infant formulations, enzymatic inter-esterification has been employed.

  5. Inter-hemispheric asymmetry of Pedersen conductance

    NASA Astrophysics Data System (ADS)

    Deng, Y.; Lu, Y.; Sheng, C.; Yue, X.

    2015-12-01

    Ionospheric conductance is very important to the magnetosphere-ionosphere coupling in the high latitude region, since it connects the polar cap potential with the currents. Meanwhile, the altitudinal distribution of Pederson conductance gives us a rough idea about the altitudinal distribution of Joule heating at high latitudes. Based on the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) satellites observations of electron density profiles from 2009-2014, Pedersen conductivity has been calculated. A climatologic study of the height-integrated Pedersen conductivities in both E (100-150 km) and F (150-600 km) regions and their ratio in different seasons, solar and geomagnetic conditions have been conducted. A significant inter-hemispheric asymmetry is identified in the seasonal variation. Meanwhile, the conductance in both regions and the conductance ratio show a strong dependence on F10.7 and Ap indices. This result will strongly help our understanding of the inter-hemispheric difference in the high-latitude electrodynamics.

  6. Calibration and Assessment of the New Acropora 'Inter-Branch Skeleton' Palaeothermometer.

    NASA Astrophysics Data System (ADS)

    Sadler, J.; Webb, G. E.; Zhao, J. X.; Nothdurft, L. D.

    2014-12-01

    Coral reefs provide an increasingly important archive of palaeoclimate data that can be used to constrain climate model simulations. Reconstructing past environments may also provide insights into the potential of reef systems to survive changes in the Earth's climate. Geochemically based climate reconstructions are predominately acquired from massive Porites colonies, yet there remain significant spatial and temporal gaps in our understanding of climate evolution where no suitable coralla have been recovered. Branching corals are commonly the dominant species in modern reef facies and their abundance suggests an untapped source for this missing information. The potential of 'inter-branch skeleton' in corymbose Acropora to act as a new palaeoclimate archive is significant. Scanning Electron Microscopy of inter-branch skeleton in Acropora from Heron Reef, southern Great Barrier Reef, reveals a lack of secondary thickening deposits that typically characterize Acropora branches and renders them unsuitable for geochemical archives. Annual density banding, similar to that used for chronological determination of geochemical sampling in massive corals, is also observed within Acropora inter-branch skeleton. Clear seasonal signals in Sr/Ca within the skeletal structure will be correlated against the network of in situ temperature recorders in Heron lagoon and on the southern reef slope to provide a new palaeotemperature transfer equation.

  7. The temporal patterns of disease severity and prevalence in schistosomiasis

    SciTech Connect

    Ciddio, Manuela; Gatto, Marino Casagrandi, Renato

    2015-03-15

    Schistosomiasis is one of the most widespread public health problems in the world. In this work, we introduce an eco-epidemiological model for its transmission and dynamics with the purpose of explaining both intra- and inter-annual fluctuations of disease severity and prevalence. The model takes the form of a system of nonlinear differential equations that incorporate biological complexity associated with schistosome's life cycle, including a prepatent period in snails (i.e., the time between initial infection and onset of infectiousness). Nonlinear analysis is used to explore the parametric conditions that produce different temporal patterns (stationary, endemic, periodic, and chaotic). For the time-invariant model, we identify a transcritical and a Hopf bifurcation in the space of the human and snail infection parameters. The first corresponds to the occurrence of an endemic equilibrium, while the latter marks the transition to interannual periodic oscillations. We then investigate a more realistic time-varying model in which fertility of the intermediate host population is assumed to seasonally vary. We show that seasonality can give rise to a cascade of period-doubling bifurcations leading to chaos for larger, though realistic, values of the amplitude of the seasonal variation of fertility.

  8. The temporal patterns of disease severity and prevalence in schistosomiasis

    NASA Astrophysics Data System (ADS)

    Ciddio, Manuela; Mari, Lorenzo; Gatto, Marino; Rinaldo, Andrea; Casagrandi, Renato

    2015-03-01

    Schistosomiasis is one of the most widespread public health problems in the world. In this work, we introduce an eco-epidemiological model for its transmission and dynamics with the purpose of explaining both intra- and inter-annual fluctuations of disease severity and prevalence. The model takes the form of a system of nonlinear differential equations that incorporate biological complexity associated with schistosome's life cycle, including a prepatent period in snails (i.e., the time between initial infection and onset of infectiousness). Nonlinear analysis is used to explore the parametric conditions that produce different temporal patterns (stationary, endemic, periodic, and chaotic). For the time-invariant model, we identify a transcritical and a Hopf bifurcation in the space of the human and snail infection parameters. The first corresponds to the occurrence of an endemic equilibrium, while the latter marks the transition to interannual periodic oscillations. We then investigate a more realistic time-varying model in which fertility of the intermediate host population is assumed to seasonally vary. We show that seasonality can give rise to a cascade of period-doubling bifurcations leading to chaos for larger, though realistic, values of the amplitude of the seasonal variation of fertility.

  9. Infusing an Inter-Professional and Inter-University Perspective into Healthcare Education

    ERIC Educational Resources Information Center

    Goldberg, Lynette R.; Koontz, Jennifer Scott; Downs, David; Uhlig, Paul; Kumar, Neil G.; Shah, Sapna; Clark, Paige E.; Coiner, Christina; Crumrine, Daiquirie

    2010-01-01

    A national (USA) student-led, case-based CLinician/Administrator Relationship Improvement OrganizatioN (CLARION) competition focuses students in medical and related healthcare programs on the provision of healthcare that is safe, timely, equitable, patient-centred, effective and efficient. Students work in four-person, inter-professional teams to…

  10. Population structure among octocoral adults and recruits identifies scale dependent patterns of population isolation in The Bahamas

    PubMed Central

    Porto-Hannes, Isabel

    2015-01-01

    Patterns of dispersal and connectivity of the Caribbean gorgonian Antillogorgia elisabethae in The Bahamas were assessed in both adults and recently settled recruits from 13 sites using microsatellite loci. Adult populations along the Little Bahama Bank (LBB) exhibited a clear pattern of isolation by distance (IBD) which described 86% of the variance in pairwise genetic distances. Estimates of dispersal based on the IBD model suggested dispersal distances along the LBB on the order of 100 m. Increasing the spatial scale to include sites separated by open ocean generated an apparent IBD signal but the relationship had a greater slope and explained less of the variance. This relationship with distance reflected both stepping stone based IBD and regional differentiation probably created by ocean currents and barriers to dispersal that are correlated with geographic distance. Analysis of recruits from 4 sites on the LBB from up to 6 years did not detect differences between years nor differences with adult populations. The result suggests that neither selection on recruits nor inter-annual variation in dispersal affected adult population structure. Assignment tests of recruits indicated the most likely sources of the recruits were the local or adjacent populations. Most of the patterning in population structure in the northern Bahamas can be explained by geographic distance and oceanographic connectivity. Recognition of these complex patterns is important in developing management plans for A. elisabethae and in understanding the effects of disturbance to adult populations of A. elisabethae and similar species with limited dispersal. PMID:26157606

  11. Essentialism promotes children's inter-ethnic bias

    PubMed Central

    Diesendruck, Gil; Menahem, Roni

    2015-01-01

    The present study investigated the developmental foundation of the relation between social essentialism and attitudes. Forty-eight Jewish Israeli secular 6-year-olds were exposed to either a story emphasizing essentialism about ethnicity, or stories controlling for the salience of ethnicity or essentialism per se. After listening to a story, children's attitudes were assessed in a drawing and in an IAT task. Compared to the control conditions, children in the ethnic essentialism condition drew a Jewish and an Arab character as farther apart from each other, and the Jewish character with a more positive affect than the Arab character. Moreover, boys in the ethnic essentialism condition manifested a stronger bias in the IAT. These findings reveal an early link between essentialism and inter-group attitudes. PMID:26321992

  12. Renewable energy annual 1995

    SciTech Connect

    1995-12-01

    The Renewable Energy Annual 1995 is the first in an expected series of annual reports the Energy Information Administration (EIA) intends to publish to provide a comprehensive assessment of renewable energy. This report presents the following information on the history, status, and prospects of renewable energy data: estimates of renewable resources; characterizations of renewable energy technologies; descriptions of industry infrastructures for individual technologies; evaluations of current market status; and assessments of near-term prospects for market growth. An international section is included, as well as two feature articles that discuss issues of importance for renewable energy as a whole. The report also contains a number of technical appendices and a glossary. The renewable energy sources included are biomass (wood), municipal solid waste, biomass-derived liquid fuels, geothermal, wind, and solar and photovoltaic.

  13. International energy annual 1997

    SciTech Connect

    1999-04-01

    The International Energy Annual presents an overview of key international energy trends for production, consumption, imports, and exports of primary energy commodities in over 220 countries, dependencies, and areas of special sovereignty. Also included are population and gross domestic product data, as well as prices for crude oil and petroleum products in selected countries. Renewable energy reported in the International Energy Annual includes hydroelectric power and geothermal, solar, and wind electric power. Also included are biomass electric power for Brazil and the US, and biomass, geothermal, and solar energy produced in the US and not used for electricity generation. This report is published to keep the public and other interested parties fully informed of primary energy supplies on a global basis. The data presented have been largely derived from published sources. The data have been converted to units of measurement and thermal values (Appendices E and F) familiar to the American public. 93 tabs.

  14. Coal industry annual 1997

    SciTech Connect

    1998-12-01

    Coal Industry Annual 1997 provides comprehensive information about US coal production, number of mines, prices, productivity, employment, productive capacity, and recoverable reserves. US Coal production for 1997 and previous years is based on the annual survey EIA-7A, Coal Production Report. This report presents data on coal consumption, coal distribution, coal stocks, coal prices, and coal quality for Congress, Federal and State agencies, the coal industry, and the general public. Appendix A contains a compilation of coal statistics for the major coal-producing States. This report includes a national total coal consumption for nonutility power producers that are not in the manufacturing, agriculture, mining, construction, or commercial sectors. 14 figs., 145 tabs.

  15. Annual Energy Review 2007

    SciTech Connect

    Seiferlein, Katherine E.

    2008-06-01

    The Annual Energy Review (AER) is the Energy Information Administration's (EIA) primary report of annual historical energy statistics. For many series, data begin with the year 1949. Included are data on total energy production, consumption, and trade; overviews of petroleum, natural gas, coal, electricity, nuclear energy, renewable energy, international energy, as well as financial and environment indicators; and data unit conversion tables. Publication of this report is required under Public Law 95–91 (Department of Energy Organization Act), Section 205(c), and is in keeping with responsibilities given to the EIA under Section 205(a)(2), which states: “The Administrator shall be responsible for carrying out a central, comprehensive, and unified energy data and information program which will collect, evaluate, assemble, analyze, and disseminate data and information....”

  16. Annual recertification: fun? Wow!

    PubMed

    Amos, A

    1994-01-01

    Learning is critical to fostering a knowledge base required for maintaining currency and furthering professional development. In the ever-changing field of nephrology, most skills practised in nursing are considered to be sanctioned medical acts or added nursing skills. Therefore, annual recertification of the skills designated as sanctioned medical acts is an expectation of the College of Nurses of Ontario. The Wellesley Hospital policy indicates one time only or annual approval of the added nursing skills. The article will discuss the use of games as a creative, non-threatening educational tool in the recertification/re-approval process currently in place at The Wellesley Hospital, renal programs. In the past two years, several games or alternative teaching strategies have been utilized to assist the staff in preparing for recertification. This paper will examine the advantages and disadvantages of utilizing alternative teaching formats. Commentary regarding the response of staff nurses, nursing management and education will be highlighted.

  17. Petroleum marketing annual 1994

    SciTech Connect

    1995-08-24

    The Petroleum Marketing Annual (PMA) provides information and statistical data on a variety of crude oils and refined petroleum products. The publication presents statistics on crude oil costs and refined petroleum products sales for use by industry, government, private sector analysis, educational institutions, and consumers. Data on crude oil include the domestic first purchase price, the fob and landed cost of imported crude oil, and the refiners` acquisition cost of crude oil. Refined petroleum product sales data include motor gasoline, distillates, residuals, aviation fuels, kerosene, and propane. The Petroleum Marketing Division, Office of Oil and Gas, Energy Information Administration ensures the accuracy, quality, and confidentiality of the published data in the Petroleum Marketing Annual. For this production, all estimates have been recalculated since their earlier publication in the Petroleum Marketing Monthly (PMM). These calculations made use of additional data and corrections that were received after the PMM publication date.

  18. NASA InterCenter Collaboration Increases ROI

    NASA Technical Reports Server (NTRS)

    Lankford, Kimberly; Best, Susan; Felton, Larry; Newhouse, Marilyn

    2012-01-01

    Funding for National Aeronautics and Space Administration (NASA) space mission operations is tighter than ever in the current environment of federal government deficit reductions. Conventional wisdom would expect this environment to drive increasing competition between NASA centers for the limited available funds. However, recent inter-center activities at the Huntsville Operations Support Center (HOSC) at NASA's Marshall Space Flight Center emphasize collaboration rather than competition and demonstrate the value of partnerships to increase the return on shrinking investments. These efforts cover a variety of activities and potential returns. To facilitate sharing data from test and verification through operations without levying requirements on data format or software tools, the HOSC is working with multiple centers on an evolutionary path toward a distributed data architecture and archive. The approach reduces the required investment by allowing the partners to reuse their existing formats and tools, while facilitating gone ]stop h user visibility into and controlled access to the full complement of data regardless of user or data location. The HOSC is also working on two activities to promote sharing operations implementations and leveraging the experts and expertise across multiple NASA sites. In one, the use of Consultative Committee for Space Data Systems (CCSDS) standards for the message abstraction layer provides an interoperability layer on top of existing ground data system communication architectures. This allows missions to select the most appropriate solutions for their requirements with a minimal investment in rehosting the components in a coherent operational environment. The other emphasizes shared tools and increased remote access to minimize travel for tests and critical activities and reduce the floor space required for a dedicated operations center. This paper summarizes these and other inter-center collaboration activities at the HOSC and the

  19. Foam patterns

    DOEpatents

    Chaudhry, Anil R; Dzugan, Robert; Harrington, Richard M; Neece, Faurice D; Singh, Nipendra P; Westendorf, Travis

    2013-11-26

    A method of creating a foam pattern comprises mixing a polyol component and an isocyanate component to form a liquid mixture. The method further comprises placing a temporary core having a shape corresponding to a desired internal feature in a cavity of a mold and inserting the mixture into the cavity of the mold so that the mixture surrounds a portion of the temporary core. The method optionally further comprises using supporting pins made of foam to support the core in the mold cavity, with such pins becoming integral part of the pattern material simplifying subsequent processing. The method further comprises waiting for a predetermined time sufficient for a reaction from the mixture to form a foam pattern structure corresponding to the cavity of the mold, wherein the foam pattern structure encloses a portion of the temporary core and removing the temporary core from the pattern independent of chemical leaching.

  20. NERSC 1998 annual report

    SciTech Connect

    Hules, John

    1999-03-01

    This 1998 annual report from the National Scientific Energy Research Computing Center (NERSC) presents the year in review of the following categories: Computational Science; Computer Science and Applied Mathematics; and Systems and Services. Also presented are science highlights in the following categories: Basic Energy Sciences; Biological and Environmental Research; Fusion Energy Sciences; High Energy and Nuclear Physics; and Advanced Scientific Computing Research and Other Projects.

  1. Annual Report 1984.

    DTIC Science & Technology

    1985-01-01

    quality activities, and coordinating activities with other Federal and non-Federal basin interests groups. - , DD Fo’N, 1473 EDITION Ort NOV6S IS...Sod•’ I TABLE OF CONTENTS (CONTINUED) PAGE SECTION VII- RESERVOIR DATA SUMMARY 1. SWD MAP 2. INDEX BY BASINS 3. INDEX IN ALPHABETICAL ORDER 4. DATA...TABLES SECTION VIII - MINUTES OF THE TRINITY RIVER BASIN INTERESTS GROUP AND THE ANNUAL SWD WATER MANAGEMENT PERSONNEL MEETING 1. TRINITY RIVER BASIN

  2. NERSC 2001 Annual Report

    SciTech Connect

    Hules, John

    2001-12-12

    The National Energy Research Scientific Computing Center (NERSC) is the primary computational resource for scientific research funded by the DOE Office of Science. The Annual Report for FY2001 includes a summary of recent computational science conducted on NERSC systems (with abstracts of significant and representative projects); information about NERSC's current systems and services; descriptions of Berkeley Lab's current research and development projects in applied mathematics, computer science, and computational science; and a brief summary of NERSC's Strategic Plan for 2002-2005.

  3. 2008 annual merit review

    SciTech Connect

    None, None

    2009-01-18

    The 2008 DOE Vehicle Technologies Program Annual Merit Review was held February 25-28, 2008 in Bethesda, Maryland. The review encompassed all of the work done by the Vehicle Technologies Program: a total of 280 individual activities were reviewed, by a total of just over 100 reviewers. A total of 1,908 individual review responses were received for the technical reviews, and an additional 29 individual review responses were received for the plenary session review.

  4. NSLS annual report 1984

    SciTech Connect

    Klaffky, R.; Thomlinson, W.

    1984-01-01

    The first comprehensive Annual Report of the National Synchrotron Light Source comes at a time of great activity and forward motion for the facility. In the following pages we outline the management changes that have taken place in the past year, the progress that has been made in the commissioning of the x-ray ring and in the enhanced utilization of the uv ring, together with an extensive discussion of the interesting scientific experiments that have been carried out.

  5. Uranium industry annual 1994

    SciTech Connect

    1995-07-05

    The Uranium Industry Annual 1994 (UIA 1994) provides current statistical data on the US uranium industry`s activities relating to uranium raw materials and uranium marketing during that survey year. The UIA 1994 is prepared for use by the Congress, Federal and State agencies, the uranium and nuclear electric utility industries, and the public. It contains data for the 10-year period 1985 through 1994 as collected on the Form EIA-858, ``Uranium Industry Annual Survey.`` Data collected on the ``Uranium Industry Annual Survey`` (UIAS) provide a comprehensive statistical characterization of the industry`s activities for the survey year and also include some information about industry`s plans and commitments for the near-term future. Where aggregate data are presented in the UIA 1994, care has been taken to protect the confidentiality of company-specific information while still conveying accurate and complete statistical data. A feature article, ``Comparison of Uranium Mill Tailings Reclamation in the United States and Canada,`` is included in the UIA 1994. Data on uranium raw materials activities including exploration activities and expenditures, EIA-estimated resources and reserves, mine production of uranium, production of uranium concentrate, and industry employment are presented in Chapter 1. Data on uranium marketing activities, including purchases of uranium and enrichment services, and uranium inventories, enrichment feed deliveries (actual and projected), and unfilled market requirements are shown in Chapter 2.

  6. Finite element method modeling to assess Laplacian estimates via novel variable inter-ring distances concentric ring electrodes.

    PubMed

    Makeyev, Oleksandr; Besio, Walter G; Makeyev, Oleksandr; Besio, Walter G; Besio, Walter G; Makeyev, Oleksandr

    2016-08-01

    Noninvasive concentric ring electrodes are a promising alternative to conventional disc electrodes. Currently, superiority of tripolar concentric ring electrodes over disc electrodes, in particular, in accuracy of Laplacian estimation has been demonstrated in a range of applications. In our recent work we have shown that accuracy of Laplacian estimation can be improved with multipolar concentric ring electrodes using a general approach to estimation of the Laplacian for an (n + 1)-polar electrode with n rings using the (4n + 1)-point method for n ≥ 2. This paper takes the next step toward further improving the Laplacian estimate by proposing novel variable inter-ring distances concentric ring electrodes. Derived using a modified (4n + 1)-point method, linearly increasing and decreasing inter-ring distances tripolar (n = 2) and quadripolar (n = 3) electrode configurations are compared to their constant inter-ring distances counterparts using finite element method modeling. Obtained results suggest that increasing inter-ring distances electrode configurations may decrease the estimation error resulting in more accurate Laplacian estimates compared to respective constant inter-ring distances configurations. For currently used tripolar electrode configuration the estimation error may be decreased more than two-fold while for the quadripolar configuration more than six-fold decrease is expected.

  7. Dominance of local sensory signals over inter-segmental effects in a motor system: experiments.

    PubMed

    Borgmann, Anke; Toth, Tibor I; Gruhn, Matthias; Daun-Gruhn, Silvia; Büschges, Ansgar

    2011-12-01

    Legged locomotion requires that information local to one leg, and inter-segmental signals coming from the other legs are processed appropriately to establish a coordinated walking pattern.However, very little is known about the relative importance of local and inter-segmental signals when they converge upon the central pattern generators (CPGs) of different leg joints.We investigated this question on the CPG of the middle leg coxa–trochanter (CTr)-joint of the stick insect which is responsible for lifting and lowering the leg.We used a semi-intact preparation with an intact front leg stepping on a treadmill, and simultaneously stimulated load sensors of the middle leg.We found that middle leg load signals induce bursts in the middle leg depressor motoneurons(MNs). The same local load signals could also elicit rhythmic activity in the CPG of the middle leg CTr-joint when the stimulation of middle leg load sensors coincided with front leg stepping. However, the influence of front leg stepping was generally weak such that front leg stepping alone was only rarely accompanied by switching between middle leg levator and depressor MN activity. We therefore conclude that the impact of the local sensory signals on the levator–depressor motor system is stronger than the inter-segmental influence through front leg stepping.

  8. Turbine inter-disk cavity cooling air compressor

    DOEpatents

    Chupp, R.E.; Little, D.A.

    1998-01-06

    The inter-disk cavity between turbine rotor disks is used to pressurize cooling air. A plurality of ridges extend radially outwardly over the face of the rotor disks. When the rotor disks are rotated, the ridges cause the inter-disk cavity to compress air coolant flowing through the inter-disk cavity en route to the rotor blades. The ridges eliminate the need for an external compressor to pressurize the air coolant. 5 figs.

  9. Turbine inter-disk cavity cooling air compressor

    DOEpatents

    Chupp, Raymond E.; Little, David A.

    1998-01-01

    The inter-disk cavity between turbine rotor disks is used to pressurize cooling air. A plurality of ridges extend radially outwardly over the face of the rotor disks. When the rotor disks are rotated, the ridges cause the inter-disk cavity to compress air coolant flowing through the inter-disk cavity en route to the rotor blades. The ridges eliminate the need for an external compressor to pressurize the air coolant.

  10. Variability of annual daily maximum rainfall of Dhaka, Bangladesh

    NASA Astrophysics Data System (ADS)

    Ahammed, Faisal; Hewa, Guna Alankarage; Argue, John R.

    2014-02-01

    This paper deals with a study on rainfall characterises of Dhaka, the capital city of Bangladesh for the period of 1953 to 2009. Data were collected from Bangladesh Meteorological Department in January 2011 and found 2.84% missing data. Descriptive statistical analysis was conducted on annual rainfall, annual daily and monthly maximum rainfall. We applied Gumbel distribution function to estimate return periods of extreme rainfall events and found that annual daily maximum rainfall equal or greater than 425 mm had a return period of 100 years. Normal distribution function was adopted to forecast rainfall variability due to global climate change and found that annual daily maximum rainfall equal or greater than 200 mm might occur in any 12 years during the period of 2010 to 2066. The outcomes of this paper can be used in better understanding rainfall patterns of Dhaka, Bangladesh.

  11. Annual growth patterns of baldcypress (Taxodium distichum) along salinity gradients

    USGS Publications Warehouse

    Thomas, Brenda L.; Doyle, Thomas W.; Krauss, Ken W.

    2015-01-01

    The effects of salinity on Taxodium distichum seedlings have been well documented, but few studies have examined mature trees in situ. We investigated the environmental drivers of T. distichum growth along a salinity gradient on the Waccamaw (South Carolina) and Savannah (Georgia) Rivers. On each river, T. distichum increment cores were collected from a healthy upstream site (Upper), a moderately degraded mid-reach site (Middle), and a highly degraded downstream site (Lower). Chronologies were successfully developed for Waccamaw Upper and Middle, and Savannah Middle. Correlations between standardized chronologies and environmental variables showed significant relationships between T. distichum growth and early growing season precipitation, temperature, and Palmer Drought Severity Index (PDSI). Savannah Middle chronology correlated most strongly with August river salinity levels. Both lower sites experienced suppression/release events likely in response to local anthropogenic impacts rather than regional environmental variables. The factors that affect T. distichum growth, including salinity, are strongly synergistic. As sea-level rise pushes the freshwater/saltwater interface inland, salinity becomes more limiting to T. distichum growth in tidal freshwater swamps; however, salinity impacts are exacerbated by locally imposed environmental modifications.

  12. Patterns of Emphysema Heterogeneity

    PubMed Central

    Valipour, Arschang; Shah, Pallav L.; Gesierich, Wolfgang; Eberhardt, Ralf; Snell, Greg; Strange, Charlie; Barry, Robert; Gupta, Avina; Henne, Erik; Bandyopadhyay, Sourish; Raffy, Philippe; Yin, Youbing; Tschirren, Juerg; Herth, Felix J.F.

    2016-01-01

    Background Although lobar patterns of emphysema heterogeneity are indicative of optimal target sites for lung volume reduction (LVR) strategies, the presence of segmental, or sublobar, heterogeneity is often underappreciated. Objective The aim of this study was to understand lobar and segmental patterns of emphysema heterogeneity, which may more precisely indicate optimal target sites for LVR procedures. Methods Patterns of emphysema heterogeneity were evaluated in a representative cohort of 150 severe (GOLD stage III/IV) chronic obstructive pulmonary disease (COPD) patients from the COPDGene study. High-resolution computerized tomography analysis software was used to measure tissue destruction throughout the lungs to compute heterogeneity (≥ 15% difference in tissue destruction) between (inter-) and within (intra-) lobes for each patient. Emphysema tissue destruction was characterized segmentally to define patterns of heterogeneity. Results Segmental tissue destruction revealed interlobar heterogeneity in the left lung (57%) and right lung (52%). Intralobar heterogeneity was observed in at least one lobe of all patients. No patient presented true homogeneity at a segmental level. There was true homogeneity across both lungs in 3% of the cohort when defining heterogeneity as ≥ 30% difference in tissue destruction. Conclusion Many LVR technologies for treatment of emphysema have focused on interlobar heterogeneity and target an entire lobe per procedure. Our observations suggest that a high proportion of patients with emphysema are affected by interlobar as well as intralobar heterogeneity. These findings prompt the need for a segmental approach to LVR in the majority of patients to treat only the most diseased segments and preserve healthier ones. PMID:26430783

  13. Assessment of the MODIS-Terra Collection 006 aerosol optical depth data over the greater Mediterranean basin and inter-comparison against MODIS C005 and AERONET

    NASA Astrophysics Data System (ADS)

    Betsikas, Marios; Hatzianastassiou, Nikos; Papadimas, Christos D.; Gkikas, Antonis; Matsoukas, Christos; Sayer, Andrew; Hsu, Christina; Vardavas, Ilias

    2016-04-01

    Aerosols are one of the key factors determining the Earth's solar radiation budget. The aerosol radiative effects are strongly dependent on aerosol optical depth (AOD) which is a good measure of atmospheric aerosol loading. Therefore, understanding better the spatial and temporal patterns of AOD at both global and regional scales is important for more accurate estimations of aerosol radiative effects. Nowadays, improved globally distributed AOD products are available largely based on satellite observations. Currently, one of the most acknowledged accurate AOD dataset is the one derived from measurements of the MODerate resolution Imaging Spectroradiometer (MODIS) instrument onboard the twin Earth Observing System (EOS) Terra and Aqua satellite platforms. The MODIS aerosol retrieval algorithm, which is used to produce AOD data, is continuously improved and updated, leading to releases of successive series, named as Collections. Recently, MODIS Collection 6 (C006) dataset has been made available. Despite their advantages, satellite AOD products have to be assessed through comparisons against ground based AOD products, such as those from AERosol Robotic Network (AERONET). The aim of the present study is to assess the newest MODIS C006 AOD product over the greater Mediterranean basin. The assessment is performed through comparisons of the MODIS-Terra C006 Level-3 AOD data against corresponding data from the previous C005 MODIS dataset, as well as versus AOD data from AERONET stations within the study region. The study period extends from 2001 to 2012 and our comparisons are performed on a monthly basis. Emphasis is given on differences between the MODIS C006 AOD data and corresponding previous C005 data, as to their spatial and temporal, seasonal and inter-annual, patterns. The results show a better agreement of MODIS C006 than C005 AOD data with AERONET, while the C006 data offer a complete spatial coverage of the study region, specifically over the northern African

  14. Rheological evaluation of inter-grade and inter-batch variability of sodium alginate.

    PubMed

    Fu, Shao; Thacker, Ankur; Sperger, Diana M; Boni, Riccardo L; Velankar, Sachin; Munson, Eric J; Block, Lawrence H

    2010-12-01

    Polymeric excipients are often the least well-characterized components of pharmaceutical formulations. The aim of this study was to facilitate the QbD approach to pharmaceutical manufacturing by evaluating the inter-grade and inter-batch variability of pharmaceutical-grade polymeric excipients. Sodium alginate, a widely used polymeric excipient, was selected for evaluation using appropriate rheological methods and test conditions. The materials used were six different grades of sodium alginate and an additional ten batches of one of the grades. To compare the six grades, steady shear measurements were conducted on solutions at 1%, 2%, and 3% w/w, consistent with their use as thickening agents. Small-amplitude oscillation (SAO) measurements were conducted on sodium alginate solutions at higher concentrations (4-12% w/w) corresponding to their use in controlled-release matrices. In order to compare the ten batches of one grade, steady shear and SAO measurements were performed on their solutions at 2% w/w and 8% w/w, respectively. Results show that the potential interchangeability of these different grades used as thickening agents could be established by comparing the apparent viscosities of their solutions as a function of both alginate concentration and shear conditions. For sodium alginate used in controlled-release formulations, both steady shear behavior of solutions at low concentrations and viscoelastic properties at higher concentrations should be considered. Furthermore, among batches of the same grade, significant differences in rheological properties were observed, especially at higher solution concentrations. In conclusion, inter-grade and inter-batch variability of sodium alginate can be determined using steady shear and small-amplitude oscillation methods.

  15. Interrater reliability of the interRAI Acute Care (interRAI AC).

    PubMed

    Wellens, Nathalie I H; Van Lancker, Aurélie; Flamaing, Johan; Gray, Len; Moons, Philip; Verbeke, Geert; Boonen, Steven; Milisen, Koen

    2012-01-01

    We examined the interrater reliability of the interRAI AC. An observational study was conducted on 3 geriatric wards. Two trained raters completed independently the interRAI AC between 24 and 48 h after admission. A sample of 100 patients (age 84.5 ± 5.6 years; 45% female) was analyzed. Interrater reliability was tested using observed agreement, kappa coefficients, and intraclass correlation coefficients. The overall kappa median value for nominal items was 0.82 (almost perfect). For items on ordinal level, both the overall weighted kappa median and the intraclass correlation coefficient median were 0.86 (almost perfect). According to conventional cut-offs for interpreting kappa statistics, reliability was almost perfect (K ≥ 0.81) for 60% of all items, substantial (0.60 < K ≤ 0.80) for 26%, moderate (0.41 < K ≤ 0.60) for 10%, and poor (K ≤ 0.40) for 4% of the items. The median observed agreement was 0.89. For 83% of the items, the observed agreement was greater than 0.80. This study showed substantial or almost perfect interrater reliability for 86% of the items. In addition to previous evidence, the current results suggest that the estimates of the interrater reliability of the interRAI AC are acceptable and provide preliminary evidence that the current version is appropriate for clinical application.

  16. Inter-speaker articulatory variability during vowel-consonant-vowel sequences in twins and unrelated speakers.

    PubMed

    Weirich, Melanie; Lancia, Leonardo; Brunner, Jana

    2013-11-01

    The purpose of this study is to examine and compare the amount of inter-speaker variability in the articulation of monozygotic twin pairs (MZ), dizygotic twin pairs (DZ), and pairs of unrelated twins with the goal of examining in greater depth the influence of physiology on articulation. Physiological parameters are assumed to be very similar in MZ twin pairs in contrast to DZ twin pairs or unrelated speakers, and it is hypothesized that the speaker specific shape of articulatory looping trajectories of the tongue is at least partly dependent on biomechanical properties and the speaker's individual physiology. By means of electromagnetic articulography (EMA), inter-speaker variability in the looping trajectories of the tongue back during /VCV/ sequences is analyzed. Results reveal similar looping patterns within MZ twin pairs but in DZ pairs differences in the shape of the loop, the direction of the upward and downward movement, and the amount of horizontal sliding movement at the palate are found.

  17. AVERAGE ANNUAL SOLAR UV DOSE OF THE CONTINENTAL US CITIZEN

    EPA Science Inventory

    The average annual solar UV dose of US citizens is not known, but is required for relative risk assessments of skin cancer from UV-emitting devices. We solved this problem using a novel approach. The EPA's "National Human Activity Pattern Survey" recorded the daily ou...

  18. Improvement of Climate Model Simulation through Inter-Model Diversity: An ENSO Example

    NASA Astrophysics Data System (ADS)

    Ham, Y. G.; Kug, J. S.

    2014-12-01

    In this study, a new methodology is developed to improve the climate simulation of state-of-the-art coupled GCMs, by post-processing based on the inter-model diversity (i.e. ensemble spread from the Multi-Model Ensemble (MME)). Based on the close connection between the interannual variability and climatological state, the distinctive relation between the inter-model diversity of the interannual variability, and that of the basic state, is found. Based on this relation, the simulated interannual variabilities can be improved, by correcting their climatological bias. In order to test this methodology, the dominant inter-model difference in precipitation responses during the ENSO is investigated, and its relationship with climatological state. It is found that the dominant inter-model diversity of the ENSO precipitation in CMIP5 is associated with the zonal location shift of the positive precipitation center during El Nino. This dominant inter-model difference is significantly correlated with the difference in the basic state. The models with wetter (dryer) climatology than the climatology of the MME over the central Pacific, tend to shift positive ENSO precipitation anomalies to the east (west). Based on the model's systematic errors in atmospheric ENSO response and bias, it is shown that the models with better climatological state tend to simulate more realistic atmospheric ENSO responses. Therefore, the statistical method to correct the ENSO response by minimizing mean bias mostly improves the ENSO response. After the statistical correction, the deficiencies in simulating the MME ENSO precipitation are improved, so that the pattern correlation of tropical atmospheric MME response is increased from 0.81 before the correction, to 0.92 after the correction. In particular, this improvement is robust in the models whose original response is far from realistic. These results provide the possibility that the methodology developed in this study can also be applied to

  19. Leafing patterns and leaf traits of four evergreen shrubs in the Patagonian Monte, Argentina

    NASA Astrophysics Data System (ADS)