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Sample records for late summer vertical

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

    USGS Publications Warehouse

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

    2010-01-01

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

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

    SciTech Connect

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

    1985-01-01

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

  3. Contribution of the phase transition of Pacific Decadal Oscillation to the late 1990s' shift in East China summer rainfall

    NASA Astrophysics Data System (ADS)

    zhu, yali

    2016-04-01

    Based on our previous study, the interdecadal changes in summer rainfall over East China in the late 1990s are further explored here. The increased local rising motion is implicated as the dominant factor of increased rainfall in the lower Huang-Huai River valley (LHR). Both the observation and numerical experiments using Community Atmosphere Model, version 4 suggest that the negative Pacific Decadal Oscillation (PDO) mode can result in rising anomalies and thus more rainfall in the LHR. The East Asian westerly jet stream (EAWJS) is suggested as a bridge to link the Pacific sea surface temperature anomalies and East Asian summer rainfall. Model results reveal that the negative PDO mode can lead to significant easterly anomalies over East Asia. As a result, the EAWJS is weakened and shifts poleward, which coincides with observed changes in EAWJS after the late 1990s. In addition, weakened and poleward shifted EAWJS can result in an anomalous ascending motion to its south (in the LHR) by modulating the jet-related secondary meridional-vertical circulation. Consequently, rainfall increased in the LHR after the late 1990s. Besides, the positive Atlantic Meridional Oscillation can only induce insignificant changes over East Asia and partly counteract the negative PDO effect there.

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

    NASA Astrophysics Data System (ADS)

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

    2012-10-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-08-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-10-01

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

  14. Biological and physical forcings of late summer chlorophyll blooms at 30°N in the oligotrophic Pacific

    NASA Astrophysics Data System (ADS)

    Wilson, Cara; Villareal, Tracy A.; Maximenko, Nikolai; Bograd, Steven J.; Montoya, Joseph P.; Schoenbaechler, Caimee A.

    Large chlorophyll blooms have been observed with ocean color satellite data in late summer near 30°N, 135-155°W in the oligotrophic subtropical Pacific. Although blooms do not develop every year, their timing and location are consistent when they do appear. Their biological and physical forcings are unknown. Here we examine biological and physical data from a number of cruises along 30°N in the eastern Pacific between 1980 and 2004, focusing on biological data from a cruise that fortuitously sampled a small chlorophyll bloom in July 2002. The climatological bloom location is characterized by elevated levels of Rhizosolenia diatom mats as well as endosymbiotic and unicellular nitrogen fixation. We conclude that nitrogen fixation and the vertical migration of Rhizosolenia diatom mats below the nutricline are likely mechanisms for the supply of new nitrogen to fuel the chlorophyll blooms and that both mechanisms could be at work. The blooms occur in the eastern gyre of the North Pacific, a region characterized by converging weak surface currents that create an environment favorable for accumulation of positively buoyant particles such as Rhizosolenia mats. These blooms could have important ecosystem consequences by impacting local carbon fluxes and serving as an aggregation point for pelagic animals.

  15. The vertical structure of cloud radiative heating over the Indian subcontinent during summer monsoon

    NASA Astrophysics Data System (ADS)

    Johansson, E.; Devasthale, A.; L'Ecuyer, T.; Ekman, A. M. L.; Tjernström, M.

    2015-10-01

    Clouds forming during the summer monsoon over the Indian subcontinent affect its evolution through their radiative impact as well as the release of latent heat. While the latter is previously studied to some extent, comparatively little is known about the radiative impact of different cloud types and the vertical structure of their radiative heating/cooling effects. Therefore, the main aim of this study is to partly fill this knowledge gap by investigating and documenting the vertical distributions of the different cloud types associated with the Indian monsoon and their radiative heating/cooling using the active radar and lidar sensors onboard CloudSat and CALIPSO. The intraseasonal evolution of clouds from May to October is also investigated to understand pre-to-post monsoon transitioning of their radiative heating/cooling effects. The vertical structure of cloud radiative heating (CRH) follows the northward migration and retreat of the monsoon from May to October. Throughout this time period, stratiform clouds radiatively warm the middle troposphere and cool the upper troposphere by more than ±0.2 K day-1 (after weighing by cloud fraction), with the largest impacts observed in June, July and August. During these months, the fraction of high thin cloud remains high in the tropical tropopause layer (TTL). Deep convective towers cause considerable radiative warming in the middle and upper troposphere, but strongly cool the base and inside of the TTL. This cooling is stronger during active (-1.23 K day-1) monsoon periods compared to break periods (-0.36 K day-1). The contrasting radiative warming effect of high clouds in the TTL is twice as large during active periods than in break periods. These results highlight the increasing importance of CRH with altitude, especially in the TTL. Stratiform (made up of alto- and nimbostratus clouds) and deep convection clouds radiatively cool the surface by approximately -100 and -400 W m-2 respectively while warming the

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

    USGS Publications Warehouse

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

    2011-01-01

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

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

    PubMed Central

    Gardner, Grant

    2016-01-01

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

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

    PubMed

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

    2016-01-01

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

  19. Impact of sea surface temperature trend on late summer Asian rainfall in the twentieth century

    NASA Astrophysics Data System (ADS)

    Bian, Qiying; Lu, Riyu

    2013-05-01

    impact of the global sea surface temperature (SST) warming trend, which is the leading mode of SST variability, on late summer Asian rainfall is analyzed based on the simulations of five atmospheric general circulation models, which are performed by the U. S. Climate Variability and Predictability Drought Working Group. Our evaluations of the model outputs indicate that these models roughly capture the main features of climatological rainfall and circulations over Asia and the western North Pacific (WNP), but they simulate a too strong monsoon trough and a too northward shifted in the subtropical anticyclone in the WNP and fail to reproduce the rain belt over East Asia. It is found that all of the models simulate an intensified WNP subtropical high (WNPSH) in late summer, an enhanced precipitation in the tropical Indian Ocean and the maritime continent, and a suppressed precipitation in the South Asian monsoon region, the South China Sea, and the Philippine Sea, when the models are forced with the SST trend, which is characterized by a significant increase in the Indian Ocean and western Pacific. All these changes are suggested to be dynamically coherent. The warmer SST trend in the Indian Ocean and western Pacific may suppress precipitation over the Philippine Sea and thus result in a lower tropospheric anticyclonic circulation over the subtropical WNP. The warmer SSTs in the Indian Ocean may also be responsible for the anomalous easterlies and resultant less rainfall over the South Asian monsoon region. The precipitation changes forced by the SST trend are similar in the maritime continent but show an apparent difference over East Asia, in comparison with the observed rainfall trend over lands. The possible reasons for this difference are discussed.

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

    PubMed

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

    2016-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

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

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

    NASA Astrophysics Data System (ADS)

    Faloona, I. C.; Lothon, M.

    2014-12-01

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

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

    USGS Publications Warehouse

    Hagstrum, J.T.; Lipman, P.W.

    1991-01-01

    The Tucson Mountains of southern Arizona are the site of an Upper Cretaceous caldera from which the rhyolitic Cat Mountain Tuff was erupted at about 72 Ma. Two magnetic units within the Cat Mountain Tuff are distinguished by paleomagnetic data in both the northern and southern Tucson Mountains. The available paleomagnetic data indicate that rocks in southern Arizona have not remained unrotated with respect to North America since Late Cretaceous time and that vertical axis rotations may have played an important role in the region during Laramide deformation. -from Authors

  4. Late-summer food of red-winged blackbirds in a fresh tidal-river marsh

    USGS Publications Warehouse

    Meanley, B.

    1961-01-01

    During late summer in the Delaware Valley and Chesapeake Bay region, hundreds of thousands of Red-winged Blackbirds feed in wild rice beds of fresh tidal-river marshes. The period during which wild rice seed is available coincides with the ripening period of a part of the corn crop, and there is evidence to indicate that the availability of the wild rice reduces bird feeding pressure on corn in the area. The importance of wild rice and other marsh plants to the redwing during the period when wild rice seed is available was studied further by field observations and by analysis of stomach contents of 130 birds collected in wild rice beds of the Patuxent River in southern Maryland. Seeds of marsh plants formed the bulk of the food of redwings collected. Dotted smartweed, wild rice, and Walter?s millet were the most important food plants. Corn was the fourth most important item. It occurred in 35, approximately one-fourth, of the stomachs

  5. Distribution and Diet of 0+ Fish within a Canyon-Shaped European Reservoir in Late Summer

    NASA Astrophysics Data System (ADS)

    Vaek, Mojmír; Kubeka, Jan; Matna, Josef; Sea, Jaromír

    2006-05-01

    The distribution and diet of age 0+ fish were studied in the deep canyon-shaped ímov Reservoir (Czech Republic), which is characterized by a longitudinal trophic gradient. During late summer of two years, 0+ fish were sampled from inshore and offshore habitats along the longitudinal reservoir axis. Offshore catches of 0+ fish from the surface layer were dominated by roach (Rutilus rutilus ), bream (Abramis brama ) and perch (Perca fluviatilis ), whereas in the deeper open water perch predominated. Inshore catches of 0+ fish were constituted mainly by perch and roach. The proportions of roach in the inshore catches were highest at the upper and most eutrophic part of the reservoir, whereas the proportions of perch in the inshore catches were higher at the downstream areas. Total catches of both inshore and offshore 0+ fish increased upstream in the reservoir. Offshore 0+ perch were of consistently smaller size than inshore 0+ perch. Inshore 0+ perch had significantly smaller size at the upstream reservoir part than at the downstream, more lacustrine regions. The diet of both inshore and offshore 0+ fish consisted predominantly of crustacean zooplankton. Perch diet was generally dominated both by cladocerans and copepods, whereas roach diet consisted chiefly of cladocerans.

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

    NASA Astrophysics Data System (ADS)

    Zhang, Wenxia; Zhou, Tianjun; Zhang, Lixia

    2016-04-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2011-02-01

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

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

    SciTech Connect

    Kassianov, Evgueni I.; Berg, Larry K.

    2011-10-01

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

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

    SciTech Connect

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

    1993-08-01

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

  10. Evolution of Vertical Moist Thermodynamic Structure Associated with the Indian Summer Monsoon 2010 in a Regional Climate Model

    NASA Astrophysics Data System (ADS)

    Raju, A.; Parekh, Anant; Gnanaseelan, C.

    2014-07-01

    The 2010 boreal summer marked a worldwide abnormal climate. An unprecedented heat wave struck East Asia in July and August 2010. In addition to this, the tropical Indian Ocean was abnormally warm during the summer of 2010. Several heavy rainfall events and associated floods were also reported in the Indian monsoon region. During the season, the monsoon trough (an east-west elongated area of low pressure) was mostly located south of its normal position and monsoon low pressure systems moved south of their normal tracks. This resulted in an uneven spatial distribution with above-normal rainfall over peninsular and Northwest India, and deficient rainfall over central and northeastern parts of India, thus prediction (and simulation) of such anomalous climatic summer season is important. In this context, evolution of vertical moist thermodynamic structure associated with Indian summer monsoon 2010 is studied using regional climate model, reanalysis and satellite observations. This synergised approach is the first of its kind to the best of our knowledge. The model-simulated fields (pressure, temperature, winds and precipitation) are comparable with the respective in situ and reanalysis fields, both in intensity and geographical distribution. The correlation coefficient between model and observed precipitation is 0.5 and the root-mean-square error (RMSE) is 4.8 mm day-1. Inter-comparison of model-simulated fields with satellite observations reveals that the midtropospheric temperature [Water vapour mixing ratio (WVMR)] has RMSE of 0.5 K (1.6 g kg-1), whereas the surface temperature (WVMR) has RMSE of 3.4 K (2.2 g kg-1). Similarly, temporal evolution of vertical structure of temperature with rainfall over central Indian region reveals that the baroclinic nature of monsoon is simulated by the model. The midtropospheric warming associated with rainfall is captured by the model, whereas the model failed to capture the surface response to high and low rainfall events. The

  11. The vertical structure of cloud radiative heating over the Indian subcontinent during summer monsoon

    NASA Astrophysics Data System (ADS)

    Johansson, E.; Devasthale, A.; L'Ecuyer, T.; Ekman, A. M. L.; Tjernström, M.

    2015-02-01

    Every year the monsoonal circulation over the Indian subcontinent gives rise to a variety of cloud types that differ considerably in their ability to heat or cool the atmosphere. These clouds in turn affect monsoon dynamics via their radiative impacts, both at the surface and in the atmosphere. New generation of satellites carrying active radar and lidar sensors are allowing realistic quantification of cloud radiative heating (CRH) by resolving the vertical structure of the atmosphere in an unprecedented detail. Obtaining this information is a first step in closing the knowledge gap in our understanding of the role that different clouds play as regulators of the monsoon and vice versa. Here, we use collocated CloudSat-CALIPSO data sets to understand following aspects of cloud-radiation interactions associated with Indian monsoon circulation. (1) How does the vertical distribution of CRH evolve over the Indian continent throughout monsoon season? (2) What is the absolute contribution of different clouds types to the total CRH? (3) How do active and break periods of monsoon affect the distribution of CRH? And finally, (4) what are the net radiative effects of different cloud types on surface heating? In general, the vertical structure of CRH follows the northward migration and the retreat of monsoon from May to October. It is found that the alto- and nimbostratus clouds intensely warm the middle troposphere and equally strongly cool the upper troposphere. Their warming/cooling consistently exceeds ±0.2 K day-1 (after weighing by vertical cloud fraction) in monthly mean composites throughout the middle and upper troposphere respectively, with largest impact observed in June, July and August. Deep convective towers cause considerable warming in the middle and upper troposphere, but strongly cool the base and inside of the tropical tropopause layer (TTL). Such cooling is stronger during active (-1.23 K day-1) monsoon conditions compared to break periods (-0.36 K day-1

  12. Vertical biogenic particle flux during Austral summer in the Antarctic Peninsula area

    NASA Astrophysics Data System (ADS)

    Anadón, Ricardo; Alvarez-Marqués, Florentina; Fernández, Emilio; Varela, Manuel; Zapata, Manuel; Gasol, Josep M.; Vaqué, Dolors

    During both FRUELA cruises, we performed eight circum-diel stations in the Bellingshausen Sea (South of Drake Passage), and the Bransfield and Gerlache straits, where MULTITRAP sediment-traps were deployed for periods of 24 h in order to study carbon (C) and nitrogen (N) export from the photic layer. Two types of regions were visited: High chlorophyll a (Chl a) areas dominated by large-sized diatoms (>10 μm), and low Chl a areas dominated by Cryptomonas sp. or microflagellates. The vertical fluxes of C, N, and Chl a, and the number of fecal pellets (FP) were measured, and the taxonomic composition of the sedimented microplankton was analysed; the results compared to the standing stocks in the water column overlaying the sediment traps. We measured higher carbon export rates in the diatom-dominated regions (Gerlache Strait), than in the stations dominated by small phytoplankton (Bransfield Strait and Bellingshausen Sea). The measured C-fluxes ranged from 115 to 800 mg C m -2 day -1. Typical C : N ratio (by atoms) varied from 5.5 to 16.4. Nitrogen export, however, was not directly related to C export and, thus, we measured changes in the C : N ratio with stations having higher abundance of FP or detritus presenting higher C : N ratios. Variations in the vertical C-flux were related to biological variables such as FP number, algal community composition (quantitative counts and qualitative SEM observations), and photosynthetic and prokaryotic activity of the sedimented material. We calculated photic layer loss rates of C, N, Chl a (0.53-8.0% day -1) and of the different microplankton taxonomic entities (0.27-9.5% day -1). Some exceptionally high loss values were found for Cryptophyceae during Fruela 96. The obtained results are discussed within the conceptual framework set by the relationships between phytoplankton size and food web structure, and concomitant carbon export from the photic layer.

  13. Summer Temperatures of Late Eocene to Early Oligocene Freshwaters: a Multi-proxy Approach

    NASA Astrophysics Data System (ADS)

    David, M. P.; Grimes, S. T.; Hooker, J. J.; Collinson, M.

    2004-12-01

    We report northern hemisphere summer palaeotemperatures derived from multiple palaeoproxies from the Hamphire Basin Eocene-Oligocene succession. Continental freshwater \\delta18O values have been determined at six horizons spanning a 3 ma interval across the Eocene-Oligocene boundary from large sets of analyses of rodent tooth enamel phosphate. Surface water \\delta18O values permit use of associated carbonate and phosphate thermometers (gastropods, charophyte gyrogonites and fish otoliths) to bracket either the mean summer growing season temperature (gastropods), the mean temperature of the warmest months of the growing season (fish otoliths) and the mean temperature of a single month in the latter part of the growing season (charophtyte gyrogonites). We argue that calculated temperatures, which range from 26\\deg C to 37\\deg C are independent of freshwater evaporation effects and of variations in initial seawater \\delta18O that may be modified by distal changes in ice volume. The time averaged mean palaeotemperatures for each fossil horizon are generally indicative of warm mesothermal conditions. However, the large standard deviations on each of the summer season palaeotemperatures suggest climate perturbations during these times and/or that the period of mineralization of the rodent teeth encompasses some seasonal variation. This succession is a key interval where the positive \\delta18O shift in the early Oligocene marine foraminiferal isotope record identifies the onset of the Antarctic Oi-1 glaciation. The data suggest there was no significant summer temperature fall across the Oi-1 glaciation itself. This result is concordant with several other recent studies in suggesting that the majority of the isotopic shift in the marine realm across the Oi-1 glaciation is linked to ice volume, not temperature change. Our new approach has allowed us to put numerical values on summer season temperatures as well as to reconstruct relative temperature change across this

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

    NASA Astrophysics Data System (ADS)

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

    2016-02-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

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

    PubMed

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

    2014-09-14

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-06-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

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

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

    NASA Astrophysics Data System (ADS)

    Xing, Nan; Li, Jianping; Wang, Lanning

    2016-09-01

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

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

    NASA Astrophysics Data System (ADS)

    Xing, Nan; Li, Jianping; Wang, Lanning

    2016-04-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

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

    NASA Astrophysics Data System (ADS)

    Pelto, M.

    2011-12-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  5. Paleomagnetic investigation of late Neogene vertical axis rotation and remagnetization in central coastal California

    NASA Astrophysics Data System (ADS)

    Horns, Daniel M.; Verosub, Kenneth L.

    1995-03-01

    Outcrops of shallow marine sedimentary rocks of the Neogene Purisima Formation and Santa Cruz Mudstone occur throughout the Santa Cruz Mountains and along the coast of Santa Cruz and San Mateo counties in California. Within the Santa Cruz Mountains, the Purisima Formation has been extensively folded and offset by reverse faults. Along the coast, the Purisima Formation and Santa Cruz Mudstone are only gently folded although the Purisima Formation is cut by the San Gregorio Fault Zone. Previous paleomagnetic studies have shown that vertical axis rotation has occurred within some parts of the San Gregorio Fault Zone. As part of a kinematic study of the San Gregorio Fault Zone, this paleomagnetic investigation of the Purisima Formation and Santa Cruz Mudstone was conducted to determine the extent of the vertical axis rotation. The characteristic paleomagnetic directions of the Purisima Formation and Santa Cruz Mudstone, which we interpret as the primary directions, indicate that a clockwise vertical axis rotation of 35 deg to 60 deg has occurred throughout the San Gregorio Zone, whereas no rotation has occurred away from the fault zone. This result suggests that vertical axis rotation is fundamentally related to shear across the San Gregorio Fault Zone. Our work also indicates that while the Purisima Formation and Santa Cruz Mudstone along the coast have retained their primary magnetizations, the Purisima Formation within the Santa Cruz Mountains has been remagnetized after folding.

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

    PubMed

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

    2015-12-01

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

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

    PubMed

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

    2015-12-01

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

  8. Century-scale variability in late-summer rainfall events recorded over seven centuries in subannually laminated lacustrine sediments, White Pass, British Columbia

    NASA Astrophysics Data System (ADS)

    Cockburn, Jaclyn M. H.; Lamoureux, Scott F.

    2007-03-01

    Formation of annually laminated sediments in Summit Lake, White Pass, British Columbia is controlled by runoff generated by snowpack and glacier melt and major rainfall events. The 700-yr varve record is divided into two subannual series (early and late) based on sedimentological criteria and sedimentary structures within each varve. A comparison of recent subannual laminae with nearby meteorological records supports the interpretation they are formed by river discharge events generated by major snow and glacier melt events and large late-summer rainfall events. A significant correlation exists between the late subannual thickness series and the size of the largest rainfall events in late summer. The long record indicates there was an abrupt increase in the thickness and frequency of major rainfall-induced sedimentary events at the end of the seventeenth century. In addition, the frequency of laminae generated by early runoff events also increased. However, early subannual varve thickness component remains statistically the same as the thickness prior to the end of the seventeenth century. This suggests the change in varve thickness at this time is due to increases in major late-summer rainfall frequency rather than increased sediment availability caused by regional Little Ice Age glacier advances.

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

    NASA Astrophysics Data System (ADS)

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

    2014-04-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  12. Interdecadal changes on the seasonal prediction of the western North Pacific summer climate around the late 1970s and early 1990s

    NASA Astrophysics Data System (ADS)

    Li, Chaofan; Lu, Riyu; Dong, Buwen

    2016-04-01

    Identifying predictability and the corresponding sources for the western North Pacific (WNP) summer climate in the case of non-stationary teleconnections during recent decades benefits for further improvements of long-range prediction on the WNP and East Asian summers. In the past few decades, pronounced increases on the summer sea surface temperature (SST) and associated interannual variability are observed over the tropical Indian Ocean and eastern Pacific around the late 1970s and over the Maritime Continent and western-central Pacific around the early 1990s. These increases are associated with significant enhancements of the interannual variability for the lower-tropospheric wind over the WNP. In this study, we further assess interdecadal changes on the seasonal prediction of the WNP summer anomalies, using May-start retrospective forecasts from the ENSEMBLES multi-model project in the period 1960-2005. It is found that prediction of the WNP summer anomalies exhibits an interdecadal shift with higher prediction skills since the late 1970s, particularly after the early 1990s. Improvements of the prediction skills for SSTs after the late 1970s are mainly found around tropical Indian Ocean and the WNP. The better prediction of the WNP after the late 1970s may arise mainly from the improvement of the SST prediction around the tropical eastern Indian Ocean. The close teleconnections between the tropical eastern Indian Ocean and WNP summer variability work both in the model predictions and observations. After the early 1990s, on the other hand, the improvements are detected mainly around the South China Sea and Philippines for the lower-tropospheric zonal wind and precipitation anomalies, associating with a better description of the SST anomalies around the Maritime Continent. A dipole SST pattern over the Maritime Continent and the central equatorial Pacific Ocean is closely related to the WNP summer anomalies after the early 1990s. This teleconnection mode is quite

  13. The Asian summer monsoon: an intercomparison of CMIP5 vs. CMIP3 simulations of the late 20th century

    NASA Astrophysics Data System (ADS)

    Sperber, K. R.; Annamalai, H.; Kang, I.-S.; Kitoh, A.; Moise, A.; Turner, A.; Wang, B.; Zhou, T.

    2013-11-01

    The boreal summer Asian monsoon has been evaluated in 25 Coupled Model Intercomparison Project-5 (CMIP5) and 22 CMIP3 GCM simulations of the late twentieth Century. Diagnostics and skill metrics have been calculated to assess the time-mean, climatological annual cycle, interannual variability, and intraseasonal variability. Progress has been made in modeling these aspects of the monsoon, though there is no single model that best represents all of these aspects of the monsoon. The CMIP5 multi-model mean (MMM) is more skillful than the CMIP3 MMM for all diagnostics in terms of the skill of simulating pattern correlations with respect to observations. Additionally, for rainfall/convection the MMM outperforms the individual models for the time mean, the interannual variability of the East Asian monsoon, and intraseasonal variability. The pattern correlation of the time (pentad) of monsoon peak and withdrawal is better simulated than that of monsoon onset. The onset of the monsoon over India is typically too late in the models. The extension of the monsoon over eastern China, Korea, and Japan is underestimated, while it is overestimated over the subtropical western/central Pacific Ocean. The anti-correlation between anomalies of all-India rainfall and Niño3.4 sea surface temperature is overly strong in CMIP3 and typically too weak in CMIP5. For both the ENSO-monsoon teleconnection and the East Asian zonal wind-rainfall teleconnection, the MMM interannual rainfall anomalies are weak compared to observations. Though simulation of intraseasonal variability remains problematic, several models show improved skill at representing the northward propagation of convection and the development of the tilted band of convection that extends from India to the equatorial west Pacific. The MMM also well represents the space-time evolution of intraseasonal outgoing longwave radiation anomalies. Caution is necessary when using GPCP and CMAP rainfall to validate (1) the time

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

    NASA Technical Reports Server (NTRS)

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

    2014-01-01

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

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

    USGS Publications Warehouse

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

    2008-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

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

    PubMed

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

    2015-09-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-09-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

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

  2. Late Neogene evolution of the East Asian monsoon revealed by terrestrial mollusk record in Western Chinese Loess Plateau: From winter to summer dominated sub-regime

    NASA Astrophysics Data System (ADS)

    Li, Fengjiang; Rousseau, Denis-Didier; Wu, Naiqin; Hao, Qingzhen; Pei, Yunpeng

    2008-10-01

    More and more evidence indicates that the onset of the East Asian (EA) monsoon can be traced back to the Oligocene-Miocene boundary (at about 23 Ma). However, the process of its evolution is still less well-known until now. Here we investigate its late Neogene evolution by analyzing a terrestrial mollusk sequence, from the Chinese Loess Plateau (CLP), covering the period between 7.1 and 3.5 Ma. Considering the modern ecological requirements of these organisms, we were able to define two groups of cold-aridiphilous (CA) and thermo-humidiphilous (TH) species, representing the EA winter and summer monsoon variations, respectively, as previously defined in the Quaternary glacial-interglacial cycles. Variations in these two groups indicate two different monsoon dominated periods during 7.1-3.5 Ma. First, between 7.1 and 5.5 Ma, the EA winter monsoon, with a 100-kyr periodicity, was dominant. Second, between 5.1 and 4 Ma, the EA summer monsoon dominated, with a 41-kyr periodicity. Furthermore, our mollusk record yields valuable evidence for a late Miocene-Pliocene transition of about 400 kyr from winter monsoon dominated towards summer monsoon dominated, associated with a periodicity transition from weak 100 kyr to 41 kyr. The strengthened winter monsoon interval, with a 100-kyr periodicity, is coeval with orbital-scale global ice-volume changes, in conjunction with the uplift of the Tibetan Plateau which probably reinforced the winter monsoon sub-regime. Conversely, closures of the Panama and Indonesian seaways, associated with changes in obliquity between 5.1 and 4 Ma, are probably major forcing factors for the observed dominant summer monsoon with 41-kyr frequency, favoring heat and moisture transports between low and high latitudes to allow TH mollusks to grow and develop in the CLP.

  3. Upwelling and surface cold patches in the Yellow Sea in summer: Effects of tidal mixing on the vertical circulation

    NASA Astrophysics Data System (ADS)

    Lü, Xingang; Qiao, Fangli; Xia, Changshui; Wang, Guansuo; Yuan, Yeli

    2010-04-01

    A three-dimensional, prognostic, wave-tide-circulation coupled numerical model is developed to study the effects of tidal mixing on the summertime vertical circulation in the Yellow Sea (YS). The distribution and mechanisms of upwelling are investigated by numerical means. Validated by historical tide gauge data, satellite sea surface temperature (SST) data, and cruise observation data, the model shows satisfactory performances in reproducing the dominant tidal system and three-dimensional sea temperature structure. Model results suggest that strong tidal mixing plays an important role in the formation of the vertical circulation in the YS. The Yellow Sea Cold Water Mass (YSCWM) is fringed by typical tidal mixing fronts (TMFs), which separate the cold, stratified water at the offshore side from the warm, well-mixed, shallow water at the other side. Considerable baroclinic gradient across the TMF makes the frontal zone the spot where the most active vertical circulation occurs; a secondary circulation is triggered with a distinct upwelling branch occurring mainly on the mixed side of the front. The numerical model produces systematic upwelling belts surrounding the YSCWM, and the upwelling is essentially induced by the TMF over sloping topography. The relative importance of tidal mixing and wind forcing for upwelling is further examined in numerical experiments. The southerly wind enhances the upwelling off the western coasts, but its overall influences in the whole YS are less important than tidal mixing. As shown by both satellite data and numerical modeling, the summertime SST field in the YS is featured by the stable existence of several site-selective surface cold patches (SCPs), most of which scatter in the waters off convex coastlines. One of the SCPs is found off Subei Bank, and the others are located off the eastern tip of Shandong Peninsula and off the three tips of Korean Peninsula. Two processes give rise to the SCP: on the one hand, TMF

  4. The vertical distribution of PM2.5 and boundary-layer structure during summer haze in Beijing

    NASA Astrophysics Data System (ADS)

    Sun, Yang; Song, Tao; Tang, Guiqian; Wang, Yuesi

    2013-08-01

    Between August 1, 2009, and August 16, 2009, physical observations of the atmospheric boundary layer and synchronous vertical observations of atmospheric particles were conducted from the Beijing 325 m meteorological tower, where the particulate matter with a diameter of 2.5 μm or less (PM2.5) analysis meters were stationed at a three-floor platform with altitudes of 8 m, 120 m and 280 m, respectively. Meanwhile, the atmospheric temperatures, relative humidity, wind speeds and wind directions between 8 m and 320 m were observed online at 15 different altitude intervals. The backscattering coefficient of aerosols in the boundary-layer atmosphere within 2.5 km height was also observed using a backscattered laser ceilometer. The observations showed that the PM2.5 pollution in the atmosphere from the ground up to 280 m in Beijing was quite high on August 2009, with a maximum of 200 μg m-3. Within 280 m, the vertical distribution of PM2.5 was inhomogeneous, with a maximum difference of up to 116 μg m-3 between levels in the night residual layer and at the ground. The high concentration of particles in the residual layer reached the ground by the next morning through convection, thus becoming severe pollutants. The PM2.5 in the near-surface layer was directly related to the reduction of ultra-violet radiation (UV), with a correlation coefficient of -0.57. Under steady weather conditions, the topographic mountain-valley breezes in Beijing superposed the land-sea breezes, resulting in a specific breath-like diurnal variation in wind direction. As a result, the PM2.5 mixed and increased in the regional area, leading to serious dust-haze pollution. Within 320 m of the boundary layer, the vertical distributions of temperature, humidity, wind speed and wind direction were inhomogeneous, and these patterns were the major factors influencing the distribution and variation of PM2.5 concentration. Under steady weather conditions, the reverse distribution of relative humidity

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

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

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

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

    USGS Publications Warehouse

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

    2007-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Bhat, G. S.; Kumar, Shailendra

    2015-03-01

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

  8. [MAX-DOAS measurements of NO2 column densities and vertical distribution at Ny-Alesund, Arctic during summer].

    PubMed

    Luo, Yu-Han; Sun, Li-Guang; Liu, Wen-Qing; Xie, Pin-Hua; Si, Fu-Qi; Zhou, Hai-Jin

    2012-09-01

    The multi-axis differential optical absorption spectroscopy (MAX-DOAS), one of the remote sensing techniques for trace gases measurements, is sensitive to the lower atmosphere by eliminating the influence of stratosphere retrieved from zenith-sky spectroscopy. Ground-based MAX-DOAS measurements were carried out to observe NO2 at Ny-Alesund, Arctic from 5th Jul to 1st Aug 2011. The differential slant column densities (DSCDs) of NO2 at four off-axis angles showed typical pattern of tropospheric absorbers. Based on the assumption that NO2 was well mixed in 0-1 km of the troposphere, the mean mixing ratio of NO2 during the measurement period was 1.023E11 molec x cm(-3). The fluctuation of NO2 might be related to the fossil fuel combustions and the photochemical reactions. The vertical distribution of NO2 at 0-3 km showed that NO2 was mainly originated from boundary layer of sea surface. PMID:23240391

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

    NASA Astrophysics Data System (ADS)

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

    2016-10-01

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

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

    USGS Publications Warehouse

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

    1998-01-01

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

  11. Late Neogene East Asian monsoon: from winter to summer dominated sub-regime and periodicity transition from 100 kyr to 41 kyr

    NASA Astrophysics Data System (ADS)

    Li, F.; Rousseau, D.-D.; Wu, N.; Hao, Q.; Pei, Y.

    2009-04-01

    More and more evidence indicates that the onset of the East Asian (EA) monsoon can be traced back to the Oligocene-Miocene boundary (at about 23 Ma). However, the process of its evolution is still less well known until now. Here we investigate its late Neogene evolution by analyzing a terrestrial mollusk sequence, from the Chinese Loess Plateau (CLP), covering the period between 7.1 and 3.5 Ma. Considering the modern ecological requirements of these organisms, we were able to define two groups of cold-aridiphilous (CA) and thermo-humidiphilous (TH) species, representing the EA winter and summer monsoon variations, respectively, as previously defined in the Quaternary glacial-interglacial cycles. Variations in these two groups indicate two different monsoon dominated periods during 7.1-3.5 Ma. First, between 7.1 and 5.5 Ma, the EA winter monsoon, with a 100 kyr periodicity, was dominant. Second, between 5.1 and 4 Ma, the EA summer monsoon dominated, with a 41 kyr periodicity. Furthermore, our mollusk record yields valuable evidence for a late Miocene-Pliocene transition of about 400 kyr from winter monsoon dominated towards summer monsoon dominated, associated with a periodicity transition from weak 100 kyr to 41 kyr. The strengthened winter monsoon interval, with a 100 kyr periodicity, is coeval with orbital-scale global ice volume changes, in conjunction with the uplift of the Tibetan Plateau which probably reinforced the winter monsoon sub-regime. Conversely, closures of the Panama and Indonesian seaways, associated with changes in obliquity between 5.1 and 4 Ma, are probably major forcing factors for the observed dominant summer monsoon with 41 kyr frequency, favoring heat and moisture transports between low and high latitudes to allow TH mollusks to grow and develop in the CLP. The transition from a 100 kyr dominated interval towards a 41 kyr dominated one is contrary to the mid-Pleistocene transition (MPT), which corresponds to ice volume expansion at high

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

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

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

  13. Booktalking: Avoiding Summer Drift

    ERIC Educational Resources Information Center

    Whittingham, Jeff; Rickman, Wendy A.

    2015-01-01

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

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

    USGS Publications Warehouse

    Schemel, Laurence E.; Cox, Marisa H.

    2005-01-01

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

  15. The distribution of bioluminescence and chlorophyll during the late summer in the North Atlantic: Maps and a predictive model

    NASA Astrophysics Data System (ADS)

    Ondercin, Daniel G.; Atkinson, Charles A.; Kiefer, Dale A.

    1995-04-01

    During August 1991 an instrument array (the Paravane) was towed continuously for several days over long distances in the North Atlantic and around the Marine Light-Mixed Layer (MLML) mooring (60°N, 21°W). Among other sensors, the Paravane carried a thermistor, a fluorometer that measured the fluorescence emitted by chlorophyll a, a bathyphotometer that measured stimulable bioluminescence, and a beam transmissometer that measured the volume attenuation coefficient at 490 nm. The record of these biooptical measurements provides a detailed description of the upper 150 m of the water column as well as of diel variability. An examination of the transects, which covered a latitudinal range from 43°N to 60°N and a longitudinal range from 13°W to 54°W, indicates that in the colder and more northerly waters most of the chlorophyll a, attenuation, and bioluminescence were found within the surface mixed layer. In the warmer waters to the south, there were subsurface maxima for all three parameters. We have used the Paravane records to test a model that provides predictions of the vertical distribution of chlorophyll a, bioluminescence, and beam attenuation from oceanographie parameters that characterize the surface mixed layer: temperature, chlorophyll a concentration, irradiance incident to the sea surface, mixed layer depth, and nitrate concentration. The first three parameters can be measured from sensors aboard satellites while the last two parameters can be obtained from oceanographie databases. The model is based upon a description of the acclimation of the phytoplankton, an assumption about the vertical distribution of phytoplankton within the euphotic zone, and an empirical description of the relationship between bioluminescence, light intensity, and phytoplankton concentration.

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

    NASA Astrophysics Data System (ADS)

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

    2016-02-01

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

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

    NASA Astrophysics Data System (ADS)

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

    1998-12-01

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

  18. Short scale variations in nutrients, ectoenzymatic activities and bottom-up effects on bacterial production and community structure during late summer-autumn transition in the open NW Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    van Wambeke, F.; Ghiglione, J.-F.; Nedoma, J.; Mével, G.; Raimbault, P.

    2009-01-01

    We examined the vertical and temporal dynamics of nutrients, ectoenzymatic activities under late summer-fall transition period (September-October 2004) in NW Mediterranean Sea in relation to temporal change in factors limiting bacterial production. The depth of the mixed layer (12.8±5.3 m) was extremely stable until the onset of the destratification period after 11 October, creating a zone where diffusion of nutrient from the much deeper phosphacline (69±12 m) and nitracline (50±8 m) was probably strongly limited. However during the second half of the cruise, a shallowing of nutriclines occured, particularly marked for nitracline. Hence, the nitrate to phosphate ratio within the mixed layer, although submitted to a high short term variability, shifted the last week of the cruise from 1.1±1.2 to 4.6±3.8, and nitrate increased by a factor 2 (0.092±0.049 μM). A corresponding switch from more than one limitation (PN) to P-only limitation of bacterial production was observed during the month as detected by enrichment bioassays. Differences in the identity of the limiting nutrient in surface (5 m: N and P at the beginning, strictly P at the end of the study) versus 80 m (labile carbon) influence greatly bacterial community structure shift between these two layers. The two communities (5 and 80 m) reacted rapidly (24 h) to changes in nutrient concentrations by drastic modification of total and active population assemblages resulting in changes in activity. For bacterial production values less than 10 ng C l-1h-1 (associated to deeper layers), aminopeptidase and lipase exhibited higher activity relative to production whereas phosphatase varied in the same proportions than BP on the range of activities tested. Our results illustrate the effect of bottom-up control on bacterial community structure and activities in the epipelagic NW Mediterranean Sea.

  19. Variations of the summer Somali and Australia cross-equatorial flows and the implications for the Asian summer monsoon

    NASA Astrophysics Data System (ADS)

    Zhu, Yali

    2012-05-01

    The temporal variations during 1948-2010 and vertical structures of the summer Somali and Australia cross-equatorial flows (CEFs) and the implications for the Asian summer monsoon were explored in this study. The strongest southerly and northerly CEFs exist at 925 hPa and 150 hPa level, respectively. The low-level Somali (LLS) CEFs were significantly connected with the rainfall in most regions of India (especially the monsoon regions), except in a small area in southwest India. In comparison to the climatology, the low-level Australia (LLA) CEFs exhibited stronger variations at interannual time scale and are more closely connected to the East Asian summer monsoon circulation than to the LLS CEFs. The East Asian summer monsoon circulation anomalies related to stronger LLA CEFs were associated with less water vapor content and less rainfall in the region between the middle Yellow River and Yangtze River and with more water vapor and more rainfall in southern China. The sea-surface temperature anomalies east of Australia related to summer LLA CEFs emerge in spring and persist into summer, with implications for the seasonal prediction of summer rainfall in East Asia. The connection between the LLA CEFs and East Asian summer monsoon rainfall may be partly due to its linkage with El Nino-Southern Oscillation. In addition, both the LLA and LLS CEFs exhibited interdecadal shifts in the late 1970s and the late 1990s, consistent with the phase shifts of Pacific Decadal Oscillation (PDO).

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

    NASA Astrophysics Data System (ADS)

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

    2010-05-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

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

    USGS Publications Warehouse

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

    1977-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  6. Seasonal overturning circulation in the Red Sea: 1. Model validation and summer circulation

    NASA Astrophysics Data System (ADS)

    Yao, Fengchao; Hoteit, Ibrahim; Pratt, Larry J.; Bower, Amy S.; Zhai, Ping; Köhl, Armin; Gopalakrishnan, Ganesh

    2014-04-01

    The overturning circulation in the Red Sea exhibits a distinct seasonally reversing pattern and is studied using high-resolution MIT general circulation model simulations. In the first part of this study, the vertical and horizontal structure of the summer overturning circulation and its dynamical mechanisms are presented from the model results. The seasonal water exchange in the Strait of Bab el Mandeb is successfully simulated, and the structures of the intruding subsurface Gulf of Aden intermediate water are in good agreement with summer observations in 2011. The model results suggest that the summer overturning circulation is driven by the combined effect of the shoaling of the thermocline in the Gulf of Aden resulting from remote winds in the Arabian Sea and an upward surface slope from the Red Sea to the Gulf of Aden set up by local surface winds in the Red Sea. In addition, during late summer two processes associated, respectively, with latitudinally differential heating and increased salinity in the southern Red Sea act together to cause the reversal of the contrast of the vertical density structure and the cessation of the summer overturning circulation. Dynamically, the subsurface northward pressure gradient force is mainly balanced by vertical viscosity resulting from the vertical shear and boundary friction in the Strait of Bab el Mandeb. Unlike some previous studies, the three-layer summer exchange flows in the Strait of Bab el Mandeb do not appear to be hydraulically controlled.

  7. The impact of the 2003 summer heat wave and the 2005 late cold wave on the phytoplankton in the north-eastern English Channel.

    PubMed

    Gómez, Fernando; Souissi, Sami

    2008-09-01

    The phytoplankton composition was investigated at two fixed stations in the north-eastern English Channel from November 1997 to December 2005. The warmest temperatures in European historical records were recorded in August 2003. This event was associated with an exceptional abundance peak of the dinoflagellates Akashiwo sanguinea (9600 cells L(-1)) and Ceratium fusus. The lowest February temperatures for the 1998-2005 period were recorded in 2005, coinciding with the absence, for the first time in recent decades, of the spring bloom of Phaeocystis globosa. The 'de-eutrophication', mainly the reduction of river nutrient loads, is progressively reducing the magnitude of the Phaeocystis blooms. Exceptionally in 2005, the colder temperatures increased water column mixing, favouring the dominance of tychoplanktonic diatoms until early March (pre-bloom period). The delay in spring stratification, lower light availability due to turbidity (resuspended sediment) and organic matter, and competition with tychoplanktonic diatoms contributed to retard the timing of the spring phytoplankton bloom and disadvantage the development of Phaeocystis. The summer 2003 European heat wave is expected to have had little influence on total annual primary production, because it occurred at mid-summer, the period of lowest annual phytoplankton abundance. However, the anomalous weather in the second half of winter 2005 did affect the annual primary production.

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

    NASA Astrophysics Data System (ADS)

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

    2016-02-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2012-09-01

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

  10. Signals of the South China Sea summer rainfall variability in the Indian Ocean

    NASA Astrophysics Data System (ADS)

    He, Zhuoqi; Wu, Renguang; Wang, Weiqiang

    2016-05-01

    The present study investigates signals of the South China Sea (SCS) summer rainfall variability in the Indian Ocean. It is found that the SCS summer rainfall has a negative relationship with December-January-February (DJF) western-equatorial Indian Ocean (WIO) sea surface temperature (SST), a positive relationship with an asymmetric mode of precipitation anomalies in the tropical Indian Ocean during March-April-May (MAM), and a positive relationship with June-July-August (JJA) South Indian Ocean (SIO) SST. The WIO SST anomalies induce same-sign southeast Indian Ocean SST anomalies through an anomalous zonal vertical circulation. The southeast Indian Ocean SST anomalies last from late winter to early summer and induce opposite-sign SCS summer rainfall anomalies via an anomalous meridional vertical circulation. The asymmetric mode influences the SCS summer rainfall variation via the North Indian Ocean (NIO) SST anomalies with significant cloud-radiation and wind-evaporation effect. Positive (negative) SIO SST anomalies drive an anomalous direct circulation between the SIO and the NIO, and an anomalous indirect circulation between the NIO and the SCS which facilitates the occurrence of cyclonic (anti-cyclonic) wind anomalies over the SCS-western North Pacific and results in positive (negative) SCS summer rainfall anomalies. Partial correlation analysis indicates that the influence of DJF WIO SST anomalies and JJA SIO SST anomalies on the SCS summer rainfall is partly ENSO-independent, while the MAM asymmetric mode is mostly related to the preceding DJF eastern Pacific SST anomalies.

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

    PubMed Central

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

    2014-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2011-02-01

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

  13. The microwave emissivity variability of snow covered first-year sea ice from late winter to early summer: a model study

    NASA Astrophysics Data System (ADS)

    Willmes, S.; Nicolaus, M.; Haas, C.

    2013-12-01

    Satellite observations of microwave brightness temperatures between 19 GHz and 85 GHz are the main data source for operational sea-ice monitoring. However, the sea ice microwave emissivity is subject to pronounced seasonal variations and shows significant hemispheric contrasts that mainly arise from differences in the rate and strength of snow metamorphism and melt. We use the thermodynamic snow model SNTHERM and the microwave emission model MEMLS to identify the contribution of regional patterns in atmospheric energy fluxes to surface emissivity variations on Arctic and Antarctic sea ice between 2000 and 2009. The obtained emissivity data reveal a pronounced seasonal cycle with a large regional variability. The emissivity variability increases from winter to early summer and is more pronounced in the Antarctic. In the pre-melt period (January-May, July-November) the variations in surface microwave emissivity due to diurnal, regional and inter-annual variability of atmospheric forcing reach up to 3.4%, 4.3%, and 9.7% for 19 GHz, 37 GHz and 85 GHz channels, respectively. Small but significant emissivity trends can be observed in the Weddell Sea during November and December as well as in Fram Strait during February. The obtained emissivity data lend themselves for an assessment of sea-ice concentration and snow-depth algorithm accuracies.

  14. The microwave emissivity variability of snow covered first-year sea ice from late winter to early summer: a model study

    NASA Astrophysics Data System (ADS)

    Willmes, S.; Nicolaus, M.; Haas, C.

    2014-05-01

    Satellite observations of microwave brightness temperatures between 19 GHz and 85 GHz are the main data sources for operational sea-ice monitoring and retrieval of ice concentrations. However, microwave brightness temperatures depend on the emissivity of snow and ice, which is subject to pronounced seasonal variations and shows significant hemispheric contrasts. These mainly arise from differences in the rate and strength of snow metamorphism and melt. We here use the thermodynamic snow model SNTHERM forced by European Re-Analysis (ERA) interim data and the Microwave Emission Model of Layered Snowpacks (MEMLS), to calculate the sea-ice surface emissivity and to identify the contribution of regional patterns in atmospheric conditions to its variability in the Arctic and Antarctic. The computed emissivities reveal a pronounced seasonal cycle with large regional variability. The emissivity variability increases from winter to early summer and is more pronounced in the Antarctic. In the pre-melt period (January-May, July-November) the standard deviations in surface microwave emissivity due to diurnal, regional and inter-annual variability of atmospheric forcing reach up to Δɛ = 0.034, 0.043, and 0.097 for 19 GHz, 37 GHz and 85 GHz channels, respectively. Between 2000 and 2009, small but significant positive emissivity trends were observed in the Weddell Sea during November and December as well as in Fram Strait during February, potentially related to earlier melt onset in these regions. The obtained results contribute to a better understanding of the uncertainty and variability of sea-ice concentration and snow-depth retrievals in regions of high sea-ice concentrations.

  15. Summer Astronomy

    ERIC Educational Resources Information Center

    Riddle, Bob

    2004-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2012-08-01

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

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

    PubMed Central

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

    2012-01-01

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

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

    USGS Publications Warehouse

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

    2012-01-01

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

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

    PubMed

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

    2012-01-01

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

  20. Do Tropical Cyclones Provide a Look at Past Changes in the Late Summer-Early Fall Jet Stream from Anomalously Low Stable Isotope Ratios in the Southern Greenland Ice Cores?

    NASA Astrophysics Data System (ADS)

    Lawrence, J. R.; Sodemann, H.; Rinn, J.; Ogle, M.; Dessler, A. E.

    2009-12-01

    Tropical cyclones have been shown to produce rain and water vapor with anomalously low stable isotope ratios. Detailed examination of tropical cyclones with GOES satellite water vapor images covering Atlantic tropical cyclones for the years 2000 to 2008 show that between 0 and 4 tropical cyclones, after making a transition to extra-tropical cyclones, appear to pass over Greenland and thereby may deposit snow having an anomalously low isotope value. Further investigation using ECWMF data and a European regional model and examination of upper level (850, 700 and 500 mb) surface maps created using NCEP re-analysis data confirm this. From 2000 to 2008 there is a decreasing trend in the number of transitioning tropical cyclones that make it to Greenland. The positioning of troughs in the Rossby waves seems to be controlling this trend. Precipitation over southern Greenland at the Dye 2 and 3 ice sites is sufficiently high that individual transitioning tropical cyclones might leave a detectable isotopic record. Therefore, a record of the characteristics of the late summer-early fall Jet Stream over North America going back perhaps centuries is a possibility.

  1. Summer Skies

    ERIC Educational Resources Information Center

    Science Scope, 2005

    2005-01-01

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

  2. Summer Opportunities.

    ERIC Educational Resources Information Center

    Winds of Change, 2002

    2002-01-01

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

  3. Summer Programs.

    ERIC Educational Resources Information Center

    Toussaint, Isabella H.

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

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

    NASA Astrophysics Data System (ADS)

    Charidemou, Miros; Hall, Ian; Ziegler, Martin

    2015-04-01

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

  5. Boost Reading Skills by Summer

    ERIC Educational Resources Information Center

    Fink, Jennifer L. W.

    2012-01-01

    The end of the school year is in sight, but it's not too late to help lower-level readers catch up. Experts across the country were asked about the most common obstacles to reading success--and effective ways to over-come them. Their insights and tips can help a teacher make a real difference before summer begins.

  6. Polar Summer

    NASA Technical Reports Server (NTRS)

    2005-01-01

    30 December 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows eroding mesas of frozen carbon dioxide in the martian south polar residual cap. During the summer season, the scarps that bound each pit and mesa in the south polar region become dark as carbon dioxide sublimes away. The darkening might result from the roughening of the surfaces from which ice is subliming, or from the concentration of trace amounts of dust on these slopes, or both.

    Location near: 84.7oS, 48.2oW Image width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Summer

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

    NASA Astrophysics Data System (ADS)

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

    2014-10-01

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

  8. Intensified impact of northern tropical Atlantic SST on tropical cyclogenesis frequency over the western North Pacific after the late 1980s

    NASA Astrophysics Data System (ADS)

    Cao, Xi; Chen, Shangfeng; Chen, Guanghua; Wu, Renguang

    2016-08-01

    Previous studies suggest that spring SST anomalies over the northern tropical Atlantic (NTA) affect the tropical cyclone (TC) activity over the western North Pacific (WNP) in the following summer and fall. The present study reveals that the connection between spring NTA SST and following summer-fall WNP TC genesis frequency is not stationary. The influence of spring NTA SST on following summer-fall WNP TC genesis frequency is weak and insignificant before, but strong and significant after, the late 1980s. Before the late 1980s, the NTA SST anomaly-induced SST anomalies in the tropical central Pacific are weak, and the response of atmospheric circulation over the WNP is not strong. As a result, the connection between spring NTA SST and following summer-fall WNP TC genesis frequency is insignificant in the former period. In contrast, after the late 1980s, NTA SST anomalies induce pronounced tropical central Pacific SST anomalies through an Atlantic-Pacific teleconnection. Tropical central Pacific SST anomalies further induce favorable conditions for WNP TC genesis, including vertical motion, mid-level relative humidity, and vertical zonal wind shear. Hence, the connection between NTA SST and WNP TC genesis frequency is significant in the recent period. Further analysis shows that the interdecadal change in the connection between spring NTA SST and following summer-fall WNP TC genesis frequency may be related to the climatological SST change over the NTA region.

  9. Indian Summer

    SciTech Connect

    Galindo, E.

    1997-08-01

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

  10. THE VERTICAL

    NASA Technical Reports Server (NTRS)

    Albert, Stephen L.; Spencer, Jeffrey B.

    1994-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

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

  12. Next Generation Summer School

    NASA Astrophysics Data System (ADS)

    Eugenia, Marcu

    2013-04-01

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

  13. The annual cycle of vertical mixing and restratification in the Northern Gulf of Eilat/Aqaba (Red Sea) based on high temporal and vertical resolution observations

    NASA Astrophysics Data System (ADS)

    Carlson, Daniel F.; Fredj, Erick; Gildor, Hezi

    2014-02-01

    The stratification in the Northern Gulf of Eilat/Aqaba follows a well-known annual cycle of well-mixed conditions in winter, surface warming in spring and summer, maximum vertical temperature gradient in late summer, and erosion of stratification in fall. The strength and structure of the stratification influences the diverse coral reef ecosystem and also affects the strength of the semi-diurnal tidal currents. Long-term (13 months) moored thermistor data, combined with high temporal and vertical resolution density profiles in deep water, show that transitions from summer to fall and winter to spring/summer occur in unpredictable, pulses and are not slow and gradual, as previously deduced from monthly hydrographic measurements and numerical simulations forced by monthly climatologies. The cooling and deepening of the surface layer in fall is marked by a transition to large amplitude, semi-diurnal isotherm displacements in the stratified intermediate layer. Stratification is rebuilt in spring and summer by intermittent pulses of warm, buoyant water that can increase the upper 100-150 m by 2 °C that force surface waters down 100-150 m over a matter of days. The stratification also varies in response to short-lived eddies and diurnal motions during winter. Thus, the variability in the stratification exhibits strong depth and seasonal dependence and occurs over range of timescales: from tidal to seasonal. We show that monthly or weekly single-cast hydrographic data under-samples the variability of the stratification in the Gulf and we estimate the error associated with single-cast assessments of the stratification.

  14. The News, Summer 1999-Summer 2000.

    ERIC Educational Resources Information Center

    Robertson, Trische, Ed.

    2000-01-01

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

  15. Slowing the Summer Slide

    ERIC Educational Resources Information Center

    Smith, Lorna

    2012-01-01

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

  16. Summer Library Reading Programs

    ERIC Educational Resources Information Center

    Fiore, Carole D.

    2007-01-01

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

  17. Summer Television Project.

    ERIC Educational Resources Information Center

    Evansville-Vanderburgh School Corp., IN.

    Three general goals guided the creation of this summer education project: to maintain academic basic skills over the summer months, to involve parents in the learning process, and to involve teachers in reading inservice training. The summer television programs available to all Indiana children are "Ride the Reading Rocket" for grade 2; "Catch a…

  18. Summer Correspondence Program.

    ERIC Educational Resources Information Center

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

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

  19. Slithering into Summer

    ERIC Educational Resources Information Center

    Scott, Catherine; Matthews, Catherine

    2012-01-01

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

  20. Summer Programs for Educators

    ERIC Educational Resources Information Center

    Curriculum Review, 2009

    2009-01-01

    There are so many great ways to extend oneself professionally--or personally--over the summer. This paper presents several opportunities for summer 2009: (1) The Teacher-to-Teacher Initiative; (2) Courage to Teach; (3) University of South Carolina's Summer Institute in Computer Science; (4) Online Program in Online Teaching; and (5) College Board…

  1. Vertical structure of recent Arctic warming.

    PubMed

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

    2008-01-01

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

  2. Hydromania: Summer Science Camp Curriculum.

    SciTech Connect

    Moura, Joan

    1995-07-01

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

  3. West Nile virus cluster analysis and vertical transmission in Culex pipiens complex mosquitoes in Sacramento and Yolo Counties, California, 2011.

    PubMed

    Fechter-Leggett, Ethan; Nelms, Brittany M; Barker, Christopher M; Reisen, William K

    2012-12-01

    West Nile virus (WNV) is now endemic in California, with annual transmission documented by the statewide surveillance system. Although much is known about the horizontal avian-mosquito transmission cycle, less is known about vertical transmission under field conditions, which may supplement virus amplification during summer and provide a mechanism to infect overwintering female mosquitoes during fall. The current study identified clusters of WNV-infected mosquitoes in Sacramento and Yolo Counties, CA, during late summer 2011 and tested field-captured ovipositing female mosquitoes and their progeny for WNV RNA to estimate the frequency of vertical transmission. Space-time clustering of WNV-positive Culex pipiens complex pools was detected in the northern Elk Grove area of Sacramento County between July 18 and September 18, 2011 (5.22 km radius; p<0.001 and RR=7.80). Vertical transmission by WNV-infected females to egg rafts was 50% and to larvae was 40%. The estimated minimal filial infection rate from WNV-positive, ovipositing females was 2.0 infected females/1,000. The potential contribution of vertical transmission to WNV maintenance and amplification are discussed. PMID:23181869

  4. Martian north polar cap summer water cycle

    NASA Astrophysics Data System (ADS)

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

    2016-10-01

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

  5. Summer library reading programs.

    PubMed

    Fiore, Carole D

    2007-01-01

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

  6. Summer Harvest in Saratov, Russia

    NASA Technical Reports Server (NTRS)

    2002-01-01

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

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

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

  7. Book Your Summer Vacation

    ERIC Educational Resources Information Center

    Texley, Juliana

    2012-01-01

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

  8. Celebrate Summer with Reading

    ERIC Educational Resources Information Center

    Texley, Juliana

    2007-01-01

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

  9. Under Summer Skies

    ERIC Educational Resources Information Center

    Texley, Juliana

    2009-01-01

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

  10. School Construction Summer Slam

    ERIC Educational Resources Information Center

    Jensen, Richard F.

    2012-01-01

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

  11. Your Best Summer Ever

    ERIC Educational Resources Information Center

    Cleaver, Samantha

    2012-01-01

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

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

    USGS Publications Warehouse

    TeWinkel, Leslie M.; Fleischer, Guy W.

    1999-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-06-01

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

  14. Late paternities.

    PubMed

    Cohen, Jean

    2007-06-01

    Late paternities are frequent. Very often these couples ask for medically assisted procreation. In general, it is considered that the couple should not be treated differently from the couple where the father is younger. Recent studies show a certain number of specific risks linked to the late paternities. Doctors and society do not act in the same way towards men and women: a 'sensible age' for women to no longer attempt pregnancy has been set in many countries at 42 years of age, whereas men aged 80 can benefit from IVF attempts and be reimbursed by the state or insurance companies. This is an obvious inequity. PMID:17579995

  15. IISME Summer Fellowship Program

    NASA Technical Reports Server (NTRS)

    1998-01-01

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

  16. Vertical profiles of N2O5 along with CH4, N2O, and H2O in the late Arctic winter retrieved from MIPAS-B infrared limb emission measurements

    NASA Astrophysics Data System (ADS)

    Wetzel, G.; von Clarmann, T.; Oelhaf, H.; Fischer, H.

    1995-11-01

    Vertical profiles of N2O5, CH4, N2O, and H2O inside the arctic vortex were retrieved from nighttime infrared limb emission spectra obtained during a flight of the Michelson interferometer for passive atmospheric sounding, balloonborne version (MIPAS-B) Fourier spectrometer from Kiruna (Sweden, 68°N) on March 14/15, 1992, as part of the European Arctic Stratospheric Ozone Experiment. Spectra were analyzed by a nonlinear multiparameter least squares fitting procedure in combination with an onion-peeling retrieval algorithm. The N2O5 results were derived from the intensity of the v12 band near 8 μm. These data represent the first ever reported N2O5 profile inside the polar vortex. Between 21.5 and 31.7 km altitude, N2O5 mixing ratios from 0.38 to 0.74 parts per billion by volume (ppbv) were inferred. Below 21.5 km there is a steep decrease in the mixing ratio toward values lower than 0.07 ppbv at 18.9 and 16.1 km. This discontinuity in the vertical profile correlates in altitude with the bulk of the Pinatubo aerosol layer inside the arctic vortex. N2O5 concentrations are calculated as a function of time since local sunset by using initial NO2 concentrations, O3 concentrations, aerosol surface area densities, and reaction rate coefficients, as found in the literature; calculated N2O5 concentrations are consistent with the MIPAS results. These suggest efficient heterogeneous hydrolysis of N2O5 having taken place on sulphate aerosol particles. Retrieved CH4 and N2O profiles reflect the subsided polar vortex air.

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

    USGS Publications Warehouse

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

    2012-01-01

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

  18. The Purdue Summer Internship

    ERIC Educational Resources Information Center

    Hamilton, William; And Others

    1976-01-01

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

  19. Chemical Physics Summer School

    SciTech Connect

    2002-06-28

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

  20. Summer Success Story.

    ERIC Educational Resources Information Center

    Matika, Francis W.

    1994-01-01

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

  1. Summer Water Safety Guide

    MedlinePlus

    ... this flyer at your pool, community center and beach bulletin boards. • Visit RedCross. org for more swimming ... GREAT SUMMER SAVINGS AT RED CROSS STORE! VINTAGE BEACH TOWEL ALL RED CROSS GEAR USE DISCOUNT CODE: ...

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

    NASA Technical Reports Server (NTRS)

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

    2010-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-10-01

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

  4. Has the intensity of the interannual variability in summer rainfall over South China remarkably increased?

    NASA Astrophysics Data System (ADS)

    Fan, Ke; Xu, Zhiqing; Tian, Baoqiang

    2014-04-01

    It is indicated in this paper that there were substantial differences of interannual variability (IIV) in summer rainfall over South China (RSC) among 1960-1977, 1978-1988, and 1989-2010. Notably, both IIV and mean RSC have significantly increased after 1992/1993. Relative to 1978-1988, the percentage increase of standard deviation (SD) of RSC is 230.32 % for 1993-2010. It indicates remarkable increase in IIV of RSC occurred 1993-2010, concurrent with rainfall increase. The results show that the mid-tropospheric meridional gradient of temperature over East Asia weakened in the later period, resulting in an anomalous cyclonic circulation, transporting more tropospheric moisture to South China and an upward motion at the middle and low levels of the troposphere. Meanwhile, IIV in the mid-tropospheric meridional gradient of temperature over East Asia resulted in IIVs both in the anomalous cyclonic circulation and in vertically integrated moisture content over South China. This scenario led to a significant increase in the IIV of summer rainfall over South China. Compared to 1978-1988, a greater increase in the IIV of warming over Mongolia-northeastern China and of excessive spring snow depth over the southeastern Tibetan Plateau were responsible for the increase in the IIV of the mid-tropospheric meridional gradient of the East Asian temperature during 1993-2010. Moreover, another slight increase in the IIV of summer rainfall over South China occurred in 1960-1977 relative to 1978-1988, which partly resulted from the weakening East Asian summer monsoon variability in the late 1970s.

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

    USGS Publications Warehouse

    Abookire, A.A.; Piatt, J.F.; Norcross, B.L.

    2001-01-01

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

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

    ERIC Educational Resources Information Center

    Johnson, Elfriede Nemetz

    1973-01-01

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

  7. Outside the paradigm: satellite discoveries of large summer chlorophyll blooms

    NASA Astrophysics Data System (ADS)

    Wilson, C.

    2010-12-01

    It is becoming increasingly rare to discover a new natural phenomenon on our planet that we don’t understand. Such a discovery has been made from satellite data showing the consistence occurrence of summer chlorophyll blooms in both the eastern region of the North Pacific Subtropical Gyre and in the southern Indian Ocean off of Madagascar. In the open ocean, outside of upwelling regions, phytoplankton blooms generally occur in the springtime, when sufficient light because available to utilize nutrients brought into the mixed-layer by winter mixing. Neither the NE Pacific blooms nor the blooms off of Madagascar fit this paradigm. The North Pacific blooms appear as ocean oases in the middle of the oligotrophic gyre, without an obvious source of nutrients to sustain the elevated chlorophyll. These blooms have a consistent seasonality, developing in the late summer, July-Sept, and lasting anywhere between 6 weeks to 5 months. Although they do not appear every year, they have been observed in 12 of 18 years of satellite ocean color data. These features are quite extensive, spanning hundreds of kms; the largest observed bloom, in 1997, matched the size of California (>400,000 km2). The blooms also have a consistent location, developing northeast of Hawaii, in the region bounded by 27-33°N and 135-155°W. Based on available in-situ data from the region it has been proposed that nitrogen fixation and the vertical migration of Rhizosolenia diatom mats below the nutricline as two possible mechanisms supplying nutrients (nitrogen) to these blooms. However, it remains unknown what physical conditions cause the blooms to develop in this one very specific spot of the N. Pacific. Satellite ocean color data has also led to the discovery of large chlorophyll blooms that develop east of Madagascar in Feb-Apr (austral summer). These blooms originate at the southern tip of Madagascar and extend eastward to 70°E, covering a distance of ~2500 km. In the SeaWiFS era (1997-present

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  10. International Summer Programs.

    ERIC Educational Resources Information Center

    Cox, June

    1979-01-01

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

  11. A Flying Summer Camp

    ERIC Educational Resources Information Center

    Mercurio, Frank X.

    1975-01-01

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

  12. Summer Youth Forestry Institute

    ERIC Educational Resources Information Center

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

    2013-01-01

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

  13. Summer Service, 1963.

    ERIC Educational Resources Information Center

    Brown, Michael J.

    1993-01-01

    The author's experiences in community service at a Quaker summer work camp 30 years ago taught him more about himself than about the community in which he helped. National service needs to include an organizing orientation that allows the strengths of both participants and community members to flourish. (SLD)

  14. Use Your Summer Wisely

    ERIC Educational Resources Information Center

    Vick, Julie Miller; Furlong, Jennifer S.

    2007-01-01

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

  15. Summer Reading That Inspires

    ERIC Educational Resources Information Center

    Texley, Juliana

    2012-01-01

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

  16. My Summer Vacation

    ERIC Educational Resources Information Center

    Galus, Pamela

    2010-01-01

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

  17. Summer by the Book

    ERIC Educational Resources Information Center

    Texley, Judiana

    2005-01-01

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

  18. Bright Beginnings: Summer Kindergarten.

    ERIC Educational Resources Information Center

    New York City Board of Education, Brooklyn, NY. Div. of Curriculum and Instruction.

    The summer kindergarten program described in this guide is designed to meet the needs of children according to their stages of development and experience. The curriculum grows out of children's interests, learning styles, strengths, and stages of development. Direct experiences though which children can explore and discover constitute the core of…

  19. Active Healthy Summer

    ERIC Educational Resources Information Center

    Elliott, Eloise

    2005-01-01

    Summer break is almost here for most elementary teachers and students. Warmer weather and additional free time to make choices create more opportunities to be physically active, whether home alone or out with friends and family. This article describes ways by which physical education specialists can encourage students' physical activity by…

  20. Waunakee's Summer Science Program.

    ERIC Educational Resources Information Center

    O'Neil, J. Peter

    1981-01-01

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

  1. Summer Opportunities for Students.

    ERIC Educational Resources Information Center

    Winds of Change, 2003

    2003-01-01

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

  2. Summer Options for Teenagers.

    ERIC Educational Resources Information Center

    Ware, Cindy

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

  3. Help for the Summer

    ERIC Educational Resources Information Center

    Greifner, Laura

    2006-01-01

    Throngs of people cover the concrete walkways of Dorney Park, an amusement park about an hour north of Philadelphia. Employees under the age of 18 make up about 40 percent of the park's summer workforce, and, park officials say, are even more crucial to its operations later in the season, when college-student employees go back to school and…

  4. Superheroes and Summer Reading.

    ERIC Educational Resources Information Center

    Meyer, Ron; Buckner, Joyce

    1980-01-01

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

  5. Books for Summer Reading.

    ERIC Educational Resources Information Center

    Phi Delta Kappan, 1991

    1991-01-01

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

  6. Summer Fish Camp.

    ERIC Educational Resources Information Center

    Remick, Dennis; Pulu, Tupou L.

    The booklet presents a description and illustrates, with photographs, the Eskimo lifestyle and the kinds of activities that occur at a summer fish camp on the Yukon River. Eleven suggested activities are listed for the teacher to present when using the booklet. Activities include studying the map of Alaska; tracing the life cycle of the fish;…

  7. Books for Summer Reading.

    ERIC Educational Resources Information Center

    Phi Delta Kappan, 1993

    1993-01-01

    Recommends fine fiction for summer reading, including Nadine Gordimer's "My Son's Story" (1991), Lillian Smith's "Strange Fruit" (1944), Josephine Hart's "Damage" (1991), Jane Smiley's "A Thousand Acres" (1991), and George Eliot's "Middlemarch" (1874). Nonfiction suggestions include Harlan Lane's "Mask of Benevolence" (1992), Diane Ackerman's "A…

  8. Summer Study Abroad.

    ERIC Educational Resources Information Center

    Cohen, Gail A., Ed.

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

  9. Books for Summer Reading.

    ERIC Educational Resources Information Center

    Phi Delta Kappan, 1996

    1996-01-01

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

  10. Dissociated Vertical Deviation

    MedlinePlus

    ... Eye Terms Conditions Frequently Asked Questions Español Condiciones Chinese Conditions Dissociated Vertical Deviation En Español Read in Chinese What is Dissociated Vertical Deviation (DVD)? DVD is ...

  11. National Board to Certify Schoolteachers to Be Chartered This Summer.

    ERIC Educational Resources Information Center

    Evangelauf, Jean

    1987-01-01

    A national board to certify teachers is expected to be chartered by late this summer and begin issuing certificates within five years. The objective is to establish high standards for teacher competence with voluntary certification, not replacement of state licensing. The plan has received widespread support. (MSE)

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

    ERIC Educational Resources Information Center

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

    2007-01-01

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

  13. Summer Reading Summer Not: How Project READS Can Advance Equity

    ERIC Educational Resources Information Center

    Kim, James S.

    2010-01-01

    This paper has three goals. First, it describes the broader research on summer reading loss. Second, it discusses how research and development efforts informed the key components of Project READS (Reading Enhances Achievement During Summer), a scaffolded voluntary summer reading intervention for children in grades 3 to 5. The second part of the…

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

    ERIC Educational Resources Information Center

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

    2012-01-01

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

  15. The Summer School Alpbach

    NASA Astrophysics Data System (ADS)

    Gitsch, Michaela; Manoharan, Periasamy K.

    2015-02-01

    Sixty young, highly qualified European science and engineering students converge annually for stimulating 10 days of work in the Austrian Alps. Four teams are formed, each of which designs a space mission, which are then judged by a jury of experts. Students learn how to approach the design of a satellite mission and explore new and startling ideas supported by experts. The Summer School Alpbach enjoys more than 30 years of tradition in providing in-depth teaching on different topics of space science and space technology, featuring lectures and concentrated working sessions on mission studies in self-organised working groups. The Summer School is organised by the Austrian Research Promotion Agency (FFG) and co-sponsored by the European Space Agency (ESA), the International Space Science Institute (ISSI), and the national space authorities of its member and cooperating states.

  16. Summer South Polar Cap

    NASA Technical Reports Server (NTRS)

    2004-01-01

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

  17. Summer 2014 Pathways Report

    NASA Technical Reports Server (NTRS)

    Hand, Zachary

    2014-01-01

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

  18. The Vertical File.

    ERIC Educational Resources Information Center

    Czopek, Vanessa

    The process of establishing the vertical file for a new branch library is traced; suggestions for making the vertical file a better resource are offered; and guidelines covering the general objective, responsibility for selection and maintenance, principles of selection, and scope of the collection for vertical files are presented. A four-item…

  19. Goddard Summer Interns: Alejandro Arambula

    NASA Video Gallery

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

  20. Vertical bounce of two vertically aligned balls

    NASA Astrophysics Data System (ADS)

    Cross, Rod

    2007-11-01

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

  1. Vertical cable surveys deliver additional seismic data

    SciTech Connect

    1995-12-01

    Texaco and a Norwegian seismic firm have patented a new system for deploying hydrophones on vertical cables for offshore surveys. The system was used in Texaco North Sea UK Ltd.`s Strathspey field during the summer. The new technique was introduced in the article, ``Peaceful use for war technology,`` published in Texaco UK`s Agenda monthly news magazine, October 1995. That article is summarized here. Using technology developed by the US Navy for antisubmarine warfare, the vertical-cable survey relies on hydrophones attached at regular intervals vertically along cables secured to the ocean floor and held taut by a buoy. The shooting vessel fires the airguns in a pattern over a large area on the surface, over and around the cables. The cables are then moved to a new location and the process is repeated, up to six times in the Strathspey application described here.

  2. Vertical axis wind turbine

    SciTech Connect

    Kato, Y.; Seki, K.; Shimizu, Y.

    1981-01-27

    Wind turbines are largely divided into vertical axis wind turbines and propeller (Horizontal axis) wind turbines. The present invention discloses a vertical axis high speed wind turbine provided with a starting and braking control system. This vertical axis wind turbine is formed by having blades of a proper airfoil fitted to respective supporting arms provided radially from a vertical rotary axis by keeping the blade span-wise direction in parallel with the axis and being provided with a low speed control windmill in which the radial position of each operating piece varies with a centrifugal force produced by the rotation of the vertical rotary axis.

  3. Vertical axis wind turbines

    DOEpatents

    Krivcov, Vladimir; Krivospitski, Vladimir; Maksimov, Vasili; Halstead, Richard; Grahov, Jurij

    2011-03-08

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

  4. Summer Learning: Accelerating Student Success

    ERIC Educational Resources Information Center

    Pitcock, Sarah; Seidel, Bob

    2015-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

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

  6. 2003 SOLAS Summer School

    NASA Technical Reports Server (NTRS)

    McGillis, Wade R.

    2003-01-01

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

  7. Summer temperature and summer monsoon history on the Tibetan plateau during the last 400 years recorded by tree rings

    NASA Astrophysics Data System (ADS)

    Bräuning, Achim; Mantwill, Bernd

    2004-12-01

    Global circulation models predict an increase of summer monsoon precipitation in High Asia as a consequence of global warming. The shortness of available meteorological records requires the reconstruction of past climate variability. However, high-resolution climate proxy records from the Tibetan plateau are scarce and of limited spatial representativeness. Here we present first evidence of increased summer monsoon intensity from the Tibetan plateau based on reconstructions of late summer (August and September) temperature and rainfall from a network of 22 maximum latewood density (MLD) chronologies of high-elevation conifer sites. After 1980, a decrease in MLD points to an increase of Indian summer monsoon activity in southern Tibet unprecedented during the past 350 years.

  8. Signatures of Currency Vertices

    NASA Astrophysics Data System (ADS)

    Holme, Petter

    2009-03-01

    Many real-world networks have broad degree distributions. For some systems, this means that the functional significance of the vertices is also broadly distributed, in other cases the vertices are equally significant, but in different ways. One example of the latter case is metabolic networks, where the high-degree vertices — the currency metabolites — supply the molecular groups to the low-degree metabolites, and the latter are responsible for the higher-order biological function, of vital importance to the organism. In this paper, we propose a generalization of currency metabolites to currency vertices. We investigate the network structural characteristics of such systems, both in model networks and in some empirical systems. In addition to metabolic networks, we find that a network of music collaborations and a network of e-mail exchange could be described by a division of the vertices into currency vertices and others.

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

    NASA Astrophysics Data System (ADS)

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

    2016-07-01

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

  10. Offset vertical radar profiling

    USGS Publications Warehouse

    Witten, A.; Lane, J.

    2003-01-01

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

  11. Vertical Axis Wind Turbine

    2002-04-01

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

  12. Assessment of Summer 1997 motor gasoline price increase

    SciTech Connect

    1998-05-01

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

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

    PubMed

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

    2015-03-01

    Culicoides sonorensis (Wirth & Jones) is the principal North American vector of bluetongue virus (BTV). BTV infection of livestock is distinctly seasonal (late summer and fall) in temperate regions of the world such as California, which has led to speculation regarding vertical transmission of the virus within the midge vector as a potential mechanism for interseasonal maintenance ("overwintering") of the virus. To evaluate potential vertical transmission of BTV in its midge vector, we fed adult midges BTV-spiked blood and used a BTV-specific quantitative reverse transcriptase polymerase chain reaction assay to evaluate parent, egg, and progeny stages of laboratory-reared C. sonorensis for the presence of viral nucleic acid. Whereas BTV nucleic acid was weakly detected in egg batches of virus-fed female midges, virus was never detected in subsequent progeny stages (larvae, pupae, and F1 generation adults). Similarly, BTV was not detected in pools of larvae collected from the waste-water lagoon of a BTV-endemic dairy farm in northern California during the seasonal period of virus transmission. Collectively, these results indicate that BTV is not readily transmitted vertically in C. sonorensis, and that persistence of the virus in long-lived parous female midges is a more likely mechanism for overwintering of BTV in temperate regions. PMID:26336312

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

    PubMed Central

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

    2015-01-01

    Culicoides sonorensis (Wirth & Jones) is the principal North American vector of bluetongue virus (BTV). BTV infection of livestock is distinctly seasonal (late summer and fall) in temperate regions of the world such as California, which has led to speculation regarding vertical transmission of the virus within the midge vector as a potential mechanism for interseasonal maintenance (“overwintering”) of the virus. To evaluate potential vertical transmission of BTV in its midge vector, we fed adult midges BTV-spiked blood and used a BTV-specific quantitative reverse transcriptase polymerase chain reaction assay to evaluate parent, egg, and progeny stages of laboratory-reared C. sonorensis for the presence of viral nucleic acid. Whereas BTV nucleic acid was weakly detected in egg batches of virus-fed female midges, virus was never detected in subsequent progeny stages (larvae, pupae, and F1 generation adults). Similarly, BTV was not detected in pools of larvae collected from the waste-water lagoon of a BTV-endemic dairy farm in northern California during the seasonal period of virus transmission. Collectively, these results indicate that BTV is not readily transmitted vertically in C. sonorensis, and that persistence of the virus in long-lived parous female midges is a more likely mechanism for overwintering of BTV in temperate regions. PMID:26336312

  15. Vertical axis windmill

    SciTech Connect

    Campbell, J.S.

    1980-04-08

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

  16. Conducting Summer School in Agriculture

    ERIC Educational Resources Information Center

    Lloyd, Melvin

    1976-01-01

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

  17. Laser tracking for vertical control

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

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

  18. Summer-time salinity variability in the North Atlantic subtropical gyre; comparison of freshening events observed in June 2006 and in July-August 2012

    NASA Astrophysics Data System (ADS)

    Reverdin, G. P.; Morisset, S.; David, L.; Boutin, J.; Martin, N.; Marié, L.; Gaillard, F.; Centurioni, L. R.; Font, J.; Salvador, J.; Ward, B.; Diverrès, D.

    2012-12-01

    The largest surface salinity in the world ocean away from semi-enclosed seas is found in late summer in the North Atlantic subtropical gyre near 25-26°N 35-40°W, where it often exceeds 37.7 psu. This region is the site of the SPURS experiment. We examined all thermosalinograph data between 2002 and 2012 from two ships regularly crossing this region, the MN Colibri and MN Toucan. The data show that this region presents a minimum of spatial variability in summer, but is interspersed by occasional tongues of lower salinity, the best observed instance having happened in June 2006. In this case, we interpret the feature as advected from the north by southward currents in front of a high feature propagating to the west as Rossby waves. In the same region, recent salinity observations from instrumented drifters indicate occasional drops (by 0.3) in July and August 2012. We will discuss how advection and vertical stirring contribute to the surface salinity budget of these features. Data from the Strasse cruise surveys in August 2012 will be used to further diagnose the summer-time surface salinity budget in this region.

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

    ERIC Educational Resources Information Center

    Alabama Public Library Service, Montgomery.

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

  20. Climate Impacts of the Loss of Summer Sea ice in the Beaufort Sea Since 2007

    NASA Astrophysics Data System (ADS)

    Overland, J. E.; Wood, K. R.; Bond, N. A.

    2012-12-01

    There has been a sequence of five warm, substantially sea ice-free summers in the Beaufort Sea since 2007 that suggest the question of whether they herald a long-term shift and "new normal" in Arctic climate. While the overall thinning of the Arctic sea ice pack is due in part to large-scale anthropogenic forcing, there are additional regional coupled air-sea ice-ocean interactions that also contribute to Arctic Amplification. The summers of 2007-2011 in the Beaufort Sea featured strong easterly wind anomalies and an Arctic Dipole pressure pattern that advected Chukchi Sea water and warm, fresh water from the MacKenzie River plume to the north, causing early melting of the sea ice, followed by rapid surface warming and enhanced upper ocean heat content and stratification due to reduced surface albedo. The Beaufort Sea south of 76° N has been absorbing almost double the amount of shortwave radiation over the last five years than in the past, roughly enough to melt 1.5 x 106 km2 of 1 m thick sea ice each year. The consequence of this heating was revealed by waveglider and satellite measurements of 6-10 C ocean temperatures in the upper 6 meters during summer 2011, perhaps the largest temperature anomalies of the Northern Hemisphere. The causes of the unusual weather pattern of the summers of 2007-2011 are generally unknown, but may relate to a more stationary blocking pattern over North America. The added upper ocean warmth means a late start to ice formation in the fall, and hence anomalous heating of the atmosphere. In response, lower atmospheric stratification is reduced allowing more vertical mixing, and higher temperatures increase the geopotential thickness and create an upward bowing of geopotential heights into the mid-troposphere. This added heating disrupts the Arctic atmospheric circulation causing regional atmospheric flow meanders, which result in different events further downstream in the subarctic during different years as persistent Arctic climate

  1. Quality of Summer Teachers Examined

    ERIC Educational Resources Information Center

    Sawchuk, Stephen

    2011-01-01

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

  2. Reverse Transfer Project, Summer 1986.

    ERIC Educational Resources Information Center

    Reis, Elizabeth

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

  3. Special Handbook: The Summer Scholar

    ERIC Educational Resources Information Center

    Thaler, Pat Koch; Shapiro, Sonya

    1978-01-01

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

  4. Evaluation of Summer Bridge Programs

    ERIC Educational Resources Information Center

    Garcia, Lisa D.; Paz, Chiara C.

    2009-01-01

    Many colleges and universities in the United States offer summer programs for their incoming students. While programs are structured and administered in a variety of ways and target various student populations, the most common type of summer bridge program aims to serve historically underrepresented students and students of low socioeconomic…

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

    SciTech Connect

    Li, Yuefeng; Leung, Lai-Yung R.

    2013-02-01

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

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

    PubMed

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

    2001-08-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

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

  8. Micromachined electrostatic vertical actuator

    DOEpatents

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

    1999-10-19

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

  9. NEWS: AAPT Summer Meeting

    NASA Astrophysics Data System (ADS)

    Mellema, Steve

    2000-11-01

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

  10. Climatology and dynamics of summer tropopause folds over the eastern Mediterranean and the Middle East

    NASA Astrophysics Data System (ADS)

    Tyrlis, E.; Skerlak, B.; Sprenger, M.; Wernli, H.; Zittis, G.; Lelieveld, J.

    2013-12-01

    A climatology of tropopause folds is presented that focus on the summer events occurring over the Eastern Mediterranean and the Middle East (EMME) based on the ERA-Interim dataset. The methodology employs an algorithm that detects folds as areas featuring multiple crossings of the dynamical tropopause and allows their classification according to their vertical extent. Our results confirm the findings of an earlier 1-year climatology that recognized a global ';hot spot' of fold activity over a sector extending from the eastern Mediterranean to Afghanistan, in the vicinity of the subtropical jet. Two distinct maxima of activity are recognized over Turkey and Iran-Afghanistan where fold occurrence exceeds 25%. Rarely, deep folds form over the Levantine Basin and Iran at surprising low latitudes. This summertime increase in fold activity defies the zonal mean seasonal cycle over the subtropics and it is driven by the South Asian Monsoon. From late spring, the EMME is gradually brought under the influence of the zonally asymmetric background state induced by the monsoon, which features an elevated tropopause and depression of isentropic surfaces. As areas of sharply sloping isentropes develop especially over the eastern Mediterranean and Iran-Afghanistan, subsidence and fold formation are favored. The monsoon also drives the interannual variability of EMME fold activity. An upward trend in fold activity is identified, especially during May that can be attributed to the recent advanced monsoon onset and the deeper convective activity throughout summer. This stronger upper level monsoon signature promotes enhanced upper level baroclinicity over the EMME that favors folding.

  11. NEWS: AAPT Summer Meeting

    NASA Astrophysics Data System (ADS)

    Mellema, Steve

    2000-11-01

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

  12. The Summer of Hydrogen

    NASA Technical Reports Server (NTRS)

    Weber, Philip

    2008-01-01

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

  13. The year without a summer

    NASA Astrophysics Data System (ADS)

    Luterbacher, J.; Pfister, C.

    2015-04-01

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

  14. Goddard Summer Interns: Danielle Wood

    NASA Video Gallery

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

  15. Potentials Unlimited: A Summer Happening.

    ERIC Educational Resources Information Center

    Croskery, Beverly; Marten, Mary Elizabeth

    1980-01-01

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

  16. Goddard Summer Interns: Andy Ryan

    NASA Video Gallery

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

  17. The large-scale frozen-in anticyclone in the 2011 Arctic summer stratosphere

    NASA Astrophysics Data System (ADS)

    Allen, Douglas R.; Douglass, Anne R.; Strahan, Susan E.

    2013-03-01

    The 2011 Arctic stratospheric final warming was characterized by a large-scale frozen-in anticyclone (FrIAC) that rapidly displaced the winter polar vortex, establishing unusually strong polar easterlies. A comprehensive overview of the 2011 FrIAC is provided using meteorological analyses, Microwave Limb Sounder (MLS) N2O observations, and N2O simulations from the Global Modeling Initiative (GMI) 3-D chemistry and transport model and the Van Leer Icosahedral Triangular Advection (VITA) 2-D (latitude × longitude) isentropic transport model. A vortex edge diagnostic is used to determine the FrIAC boundary, allowing quantification of several FrIAC properties. The 2011 FrIAC originated over North Africa in late March and traveled eastward and poleward over 2 weeks, forming a strong anticyclone that extended from ~580-2100 K potential temperature (~25-50 km). Low potential vorticity (PV) was transported to the pole with the FrIAC in early April; during May, most of the PV signature decayed due to diabatic processes. A small remnant negative PV anomaly persisted near the pole until mid-June. Tracer equivalent latitude was low initially and remained low throughout the summer. GMI, VITA, and MLS showed elevated N2O in the FrIAC, although the peak value was smaller in GMI due to a subtropical low bias. The high-resolution (~20 km) VITA filamentary structure quantitatively matched most of the features observed by MLS when smoothed to match the MLS resolution. The high-N2O anomaly persisted in the middle stratosphere over 4 months until late August, when it was destroyed by horizontal and vertical shearing, combined with photochemical processes.

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

    NASA Astrophysics Data System (ADS)

    Jury, Mark R.

    2016-02-01

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

  19. Summer Final Report

    NASA Technical Reports Server (NTRS)

    Makidi, Nitou

    2012-01-01

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

  20. Seasonal variation of diel vertical migration of zooplankton from ADCP backscatter time series data in the Lazarev Sea, Antarctica

    NASA Astrophysics Data System (ADS)

    Cisewski, Boris; Strass, Volker H.; Rhein, Monika; Krägefsky, Sören

    2010-01-01

    Ten-month time series of mean volume backscattering strength (MVBS) and vertical velocity obtained from three moored acoustic Doppler current profilers (ADCPs) deployed from February until December 2005 at 64°S, 66.5°S and 69°S along the Greenwich Meridian were used to analyse the diel vertical zooplankton migration (DVM) and its seasonality and regional variability in the Lazarev Sea. The estimated MVBS exhibited distinct patterns of DVM at all three mooring sites. Between February and October, the timing of the DVM and the residence time of zooplankton at depth were clearly governed by the day-night rhythm. Mean daily cycles of the ADCP-derived vertical velocity were calculated for successive months and showed maximum ascent and descent velocities of 16 and -15 mm s -1. However, a change of the MVBS pattern occurred in late spring/early austral summer (October/November), when the zooplankton communities ceased their synchronous vertical migration at all three mooring sites. Elevated MVBS values were then concentrated in the uppermost layers (<50 m) at 66.5°S. This period coincided with the decay of sea ice coverage at 64°S and 66.5°S between early November and mid-December. Elevated chlorophyll concentrations, which were measured at the end of the deployment, extended from 67°S to 65°S and indicated a phytoplankton bloom in the upper 50 m. Thus, we propose that the increased food supply associated with an ice edge bloom caused the zooplankton communities to cease their DVM in favour of feeding.

  1. OH vertical column abundance - Tropical measurements

    NASA Astrophysics Data System (ADS)

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

    1990-09-01

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

  2. OH vertical column abundance - Tropical measurements

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

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

  3. Vertical shaft windmill

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

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

  4. Vertical axis windmill

    SciTech Connect

    Zheug, Y.K.

    1984-03-06

    A vertical axis windmill has a blade pivotally connected to a rotatable support structure on an axis passing through its center of gravity which is arranged to lie forward of its aerodynamic center whereby the blade automatically swings outwardly and inwardly when moving on the windward and leeward sides respectively of the axis of rotation of said support means.

  5. Vertical shaft windmill

    SciTech Connect

    Grana, D.C.; Inge, S.V. Jr.

    1983-11-15

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

  6. Aiding Vertical Guidance Understanding

    NASA Technical Reports Server (NTRS)

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

    1998-01-01

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

  7. Warm summers during Younger Dryas cold reversal over Eurasia

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

  9. Summer Fun in the Sun

    NASA Astrophysics Data System (ADS)

    Alexander, D.; Noldon, D.

    2002-05-01

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

  10. Hottest summers the new normal

    NASA Astrophysics Data System (ADS)

    Camargo, Suzana J.; Seth, Anji

    2016-08-01

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

  11. Summer Ice and Carbon Dioxide

    NASA Astrophysics Data System (ADS)

    Kukla, G.; Gavin, J.

    1981-10-01

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

  12. Summer ice and carbon dioxide

    SciTech Connect

    Kukla, G.; Gavin, J.

    1981-10-30

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

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

    ERIC Educational Resources Information Center

    Browne, Daniel

    2013-01-01

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

  14. 1998 Complex Systems Summer School

    SciTech Connect

    1998-12-15

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

  15. Jamming in Vertical Channels

    NASA Astrophysics Data System (ADS)

    Baxter, G. William; Steel, Fiona

    2011-03-01

    We study jamming of low aspect-ratio cylindrical Delrin grains in a vertical channel. Grain heights are less than their diameter so the grains resemble antacid tablets, coins, or poker chips. These grains are allowed to fall through a vertical channel with a square cross section where the channel width is greater than the diameter of a grain and constant throughout the length of the channel with no obstructions or constrictions. Grains are sometimes observed to form jams, stable structures supported by the channel walls with no support beneath them. The probability of jam occurrence and the strength or robustness of a jam is effected by grain and channel sizes. We will present experimental measurements of the jamming probability and jam strength in this system and discuss the relationship of these results to other experiments and theories. Supported by an Undergraduate Research Grant from Penn State Erie, The Behrend College.

  16. Jamming in Vertical Channels

    NASA Astrophysics Data System (ADS)

    Baxter, G. William; McCausland, Jeffrey; Steel, Fiona

    2010-03-01

    We experimentally study jamming of cylindrical grains in a vertical channel. The grains have a low aspect-ratio (height/diameter < 1) so their shape is like antacid tablets or poker chips. They are allowed to fall through a vertical channel with a square cross section. The channel width is greater than the diameter of a grain and constant throughout the length of the channel with no obstructions or constrictions. It is observed that grains sometimes jam in this apparatus. In a jam, grains form a stable structure from one side of the channel to the other with nothing beneath them. Jams may be strong enough to support additional grains above. The probability of a jam occurring is a function of the grain height and diameter. We will present experimental measurements of the jamming probability in this system and discuss the relationship of these results to other experiments and theories.

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

    PubMed Central

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

    2015-01-01

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

  18. Water deficit and induction of summer dormancy in perennial Mediterranean grasses

    PubMed Central

    Volaire, Florence; Seddaiu, Giovanna; Ledda, Luigi; Lelievre, François

    2009-01-01

    Background and Aims Summer dormancy is a trait conferring superior drought survival in Mediterranean perennial grasses. As the respective roles of environmental factors and water deficit on induction of summer dormancy are unclear, the effect of intense drought were tested under contrasting day lengths in a range of forage and native grasses. Methods Plants of Poa bulbosa, Dactylis glomerata ‘Kasbah’ and Lolium arundinaceum ‘Flecha’ were grown in pots (a) from winter to summer in a glasshouse and subjected to either an early or a late-spring drought period followed by a summer water deficit and (b) in controlled conditions, with long days (LD, 16 h) or short days (SD, 9 h) and either full irrigation or water deficit followed by rehydration. Leaf elongation, senescence of aerial tissues and dehydration of basal tissues were measured to assess dormancy. Endogenous abscisic acid (ABA) in basal tissues was determined by monoclonal immunoassay analysis. Key Results Even under irrigation, cessation of leaf elongation, senescence of lamina and relative dehydration of basal tissues were triggered only by a day length longer than 13 h 30 min (late spring and LD) in plants of Poa bulbosa and Dactylis glomerata ‘Kasbah’ which exhibit complete dormancy. Plants of Lolium arundinaceum ‘Flecha’ maintained leaf growth under irrigation irrespective of the day length since its dormancy is incomplete. ABA concentrations were not higher during late-spring drought than early, and could not be associated with spring dormancy induction. In summer, ABA concentration in bulbs of the desiccation-tolerant Poa were greater than in basal tissues of other species. Conclusions The results of both experiments tend to invalidate the hypothesis that water deficit has a role in early summer-dormancy induction in the range of tested grasses. However, a late-spring drought tends to increase plant senescence and ABA accumulation in basal tissues of forage grasses which could enhance

  19. GLEANINGS FROM A SUMMER INSTITUTE.

    ERIC Educational Resources Information Center

    Twin City Inst. for Talented Youth, St. Paul, Minn.

    IN THIS REPORT TO THE ENGLISH TEACHING PROFESSION, THE TWIN CITY INSTITUTE STAFF DESCRIBES ITS CURRICULUM EXPERIMENTATION WITH ACADEMICALLY TALENTED HIGH SCHOOL STUDENTS DURING THE SUMMER OF 1967. THE FOLLOWING COURSES ARE BRIEFLY DISCUSSED IN THEIR REPORTS--(1) COMPOSITION AND RHETORIC, IN WHICH THEORY AND PRACTICE WERE BALANCED, AND EXPOSITION…

  20. Make Summer Your Growing Season.

    ERIC Educational Resources Information Center

    Simons, Harriet

    1982-01-01

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

  1. Summer 1993 Transient Student Report.

    ERIC Educational Resources Information Center

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

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

  2. The Oklahoma Summer Arts Institute.

    ERIC Educational Resources Information Center

    Suttle, Denise

    1982-01-01

    Programs were offered for fine arts students, 14-18 years old, in nine areas: orchestra, ballet, modern dance, acting, creative writing, mime, painting, printmaking, and photography. Guest artists also participated. The effect of the summer session upon the work of the students is easily recognizable. (RM)

  3. Why Have a Summer Program?

    ERIC Educational Resources Information Center

    Crownover, Jerry

    1976-01-01

    Farmers, agribusinessmen, students, and the community need the help and support of a 12-month program in vocational agriculture. Experience programs, leadership training, local and county fairs, agricultural mechanics programs, teachers' organizations, student recruitment, and adult programs would suffer if summer programs are eliminated. (MS)

  4. Summer Technical Institute. Final Report.

    ERIC Educational Resources Information Center

    Packard, Beth

    The Summer Technical Institute project was funded by the Arizona Department of Education to encourage sex equity in vocational education in the state. The project was designed to (1) encourage young women to consider technical careers, (2) provide activities to promote success and self-confidence, (3) provide an opportunity for young women to…

  5. Welcome to LANL Summer 2012

    SciTech Connect

    Bishop, Alan

    2012-06-19

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

  6. Summer Reading Goes High Tech

    ERIC Educational Resources Information Center

    Fink, Jennifer L. W.

    2012-01-01

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

  7. The Encouragement of Summer Enrollment.

    ERIC Educational Resources Information Center

    Montgomery, David C.

    1982-01-01

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

  8. Arctic Sea Ice, Summer 2014

    NASA Video Gallery

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

  9. 1988 Award Winning Summer Programs.

    ERIC Educational Resources Information Center

    Exceptional Parent, 1989

    1989-01-01

    Briefly described are four award winning summer programs including a Massachusetts Girl Scout camp which mainstreams girls with disabilities; a New York camp serving siblings of children with disabilities; a Texas camp which utilizes volunteers to serve disabled children who may have serious medical conditions; and a California camp offering…

  10. Award Winning Summer Programs--1987.

    ERIC Educational Resources Information Center

    Exceptional Parent, 1988

    1988-01-01

    Four award-winning summer programs provide opportunities for disabled children. Agassiz Village integrates physically disabled, inner-city, suburban, and rural campers. Camp Challenge serves hearing-impaired children and their families. Minspeak provides hands-on experience with assistive equipment and techniques for nonspeaking children, parents,…

  11. Development and Testing of the Variable Vertical Resolution Fourth Order GCM

    NASA Technical Reports Server (NTRS)

    Helfand, H. M.; Dlouhy, R.; Pfaendtner, J.; Takacs, L. L.

    1985-01-01

    The vertical coordinate of the Fourth Order Model has been generalized so that the model can now run with an arbitrary number of vertical layers and so that the thicknesses of these layers can be arbitrarily specified (in the sigma coordinate). This Variable Vertical Resolution (VVR) version of the Fourth Order Model will soon replace the current production model. To assess the skill of the VVR model, it has been run with 9 equally spaced layers and compared with the current production model. In two Northern Hemispheric winter cases and one summer case, the two models were virtually identical in forecast skill for 6 to 7 days. After that the VVR model was slightly better in the winter cases and the production model was slightly better in the summer case. The only exception to this was that after 2 days the production model gave slightly more skillful 500 mb forecasts in the tropics for the summer case.

  12. Investigation of summer monsoon rainfall variability in Pakistan

    NASA Astrophysics Data System (ADS)

    Hussain, Mian Sabir; Lee, Seungho

    2016-08-01

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

  13. Features of clouds and convection during the pre- and post-onset periods of the Asian summer monsoon

    NASA Astrophysics Data System (ADS)

    Wang, Yi; Wang, Chenghai

    2016-02-01

    The statistical characteristics of the vertical structure of clouds in the Asian summer monsoon region are investigated using two CloudSat standard products (Geometrical Profiling Product (GEOPROF) and GEOPROF-lidar) during the pre- and post-onset periods of the Asian summer monsoon, from April to August in 2007-2010. The characteristics of the vertical structure of clouds are analyzed and compared for different underlying surfaces in four subregions during this period. Also analyzed are the evolution of precipitation and hydrometeors with the northward advance of the Asian summer monsoon, and different hydrometeor characteristics attributed to the underlying surface features. The results indicate that the vertical cloud amounts increase significantly after the summer monsoon onset; this increase occurs first in the upper troposphere and then at lower altitudes over tropical regions (South Asian and tropical Northwest Pacific regions). The heights of the cloud top ascend, and the vertical height between the top and the base of the whole cloud increases. Single-layer (SL) and double-layer (DL) hydrometeors contribute over half and one third of the cloudiness in these 5 months (April to August), respectively. The multilayer frequencies increase in four different regions, and cloud layer depths (CLD) increase after the summer monsoon onset. These changes are stronger in tropical regions than in subtropical regions, while the vertical distance between cloud layers (VDCL) deceases in tropical regions and increases in subtropical regions.

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

    NASA Astrophysics Data System (ADS)

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

    2004-09-01

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

  15. Summer foods of lesser scaup in subarctic taiga

    USGS Publications Warehouse

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

    1970-01-01

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

  16. Youth Indicators of Late-M Dwarfs

    NASA Astrophysics Data System (ADS)

    Feldman, Daniel; Cruz, K.; Lépine, S.; Alpert, N.

    2011-01-01

    We present a study in which we searched for a correlation between weak Na absorption doublet (8183Å, 8194Å) and strong H-Alpha emission (6563Å) in late-M dwarf stars (M6-M9), as both are indicative of youth. Our sample consists of late-M Dwarfs from the LSPM Survey (Lépine and Shara, 2005), which contain stars with measured proper motions of mu > 40 mas/yr. Measurements for emission and absorption strength were made using spectral indices. Our preliminary results are presented; future work will include a similar analysis of early type M Dwarfs, as well as kinematics. This work was funded by the CUNY Summer Undergraduate Research Program, as well as the CUNY Macaulay Honors College, and we acknowledge the hospitality of the American Museum of Natural History.

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

    NASA Astrophysics Data System (ADS)

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

    2016-09-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-07-01

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

  19. 'Endurance' Untouched (vertical)

    NASA Technical Reports Server (NTRS)

    2004-01-01

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

  20. Par Pond vegetation status Summer 1995 -- Summary

    SciTech Connect

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

    1996-01-01

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

  1. 76 FR 38307 - Fisheries of the Northeastern United States; Recreational Management Measures for the Summer...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-30

    ... 2011 summer flounder, scup, and black sea bass fisheries was published on April 21, 2011 (76 FR 22350... previously established by rulemaking conducted in late 2010 (75 FR 81498; December 28, 2010). The 2011... recreational fishery. NMFS implemented Framework Adjustment 2 to the FMP on July 29, 2001 (66 FR 36208),...

  2. Vertical wind turbine

    SciTech Connect

    Danson, D.P.

    1988-08-16

    This patent describes a wind driven turbine of the vertical axis type comprising: (a) a support base; (b) a generally vertical column rotatably mounted to the support base; (c) upper and lower support means respectively mounted on the column for rotation therewith; wind driven blades connected between the upper and lower support means for rotation about the column and each blade being individually rotatable about a blade axis extending longitudinally through the blade to vary a blade angle of attach thereof relative to wind velocity during rotation about the column; and (e) control means for variably adjusting angles of attack of each blade to incident wind, the control means including a connecting rod means having drive means for rotating each blade about the associated blade axis in response to radial movement of the connecting rod means and control shaft pivotally mounted within the column and having a first shaft portion connected to the connecting rod means and a second shaft portion radially offset from the first shaft portion and pivotally connected to radially displace the first portion and thereby the connecting rod means to vary the blade angles of attack during rotation about the column.

  3. Artists Paint ... Summer: Grade 2

    ERIC Educational Resources Information Center

    Herberholz, Barbara

    2012-01-01

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

  4. Summer Series 2012 - Shashi Buluswar

    ScienceCinema

    Shashi Buluswar

    2016-07-12

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

  5. Chemical and Biological Summer Poisons

    PubMed Central

    Lees, Ronald E. M.

    1972-01-01

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

  6. SNOWMASS (DPF Community Summer Study)

    SciTech Connect

    Cronin-Hennessy, et al, Daniel

    2013-08-06

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

  7. Summer Series 2012 - Shashi Buluswar

    SciTech Connect

    Shashi Buluswar

    2012-08-08

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  9. Cloud-Scale Vertical Velocity and Turbulent Dissipation Rate Retrievals

    DOE Data Explorer

    Shupe, Matthew

    2013-05-22

    Time-height fields of retrieved in-cloud vertical wind velocity and turbulent dissipation rate, both retrieved primarily from vertically-pointing, Ka-band cloud radar measurements. Files are available for manually-selected, stratiform, mixed-phase cloud cases observed at the North Slope of Alaska (NSA) site during periods covering the Mixed-Phase Arctic Cloud Experiment (MPACE, late September through early November 2004) and the Indirect and Semi-Direct Aerosol Campaign (ISDAC, April-early May 2008). These time periods will be expanded in a future submission.

  10. Ticket to a First Class Summer.

    ERIC Educational Resources Information Center

    Instructor, 1987

    1987-01-01

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

  11. Summer Travel: Plan Ahead To Stay Healthy

    MedlinePlus

    ... This Issue Features Summer Travel Strange Migrations and Killer Cramps Health Capsules How Secondhand Smoke Affects the ... healthy.” search Features Summer Travel Strange Migrations and Killer Cramps Wise Choices Links Plan for Healthy Travel ...

  12. Vertical profile of 137Cs in soil.

    PubMed

    Krstić, D; Nikezić, D; Stevanović, N; Jelić, M

    2004-12-01

    In this paper, a vertical distribution of 137Cs in undisturbed soil was investigated experimentally and theoretically. Soil samples were taken from the surroundings of the city of Kragujevac in central Serbia during spring-summer of 2001. The sampling locations were chosen in such a way that the influence of soil characteristics on depth distribution of 137Cs in soil could be investigated. Activity of 137Cs in soil samples was measured using a HpGe detector and multi-channel analyzer. Based on vertical distribution of 137Cs in soil which was measured for each of 10 locations, the diffusion coefficient of 137Cs in soil was determined. In the next half-century, 137Cs will remain as the source of the exposure. Fifteen years after the Chernobyl accident, and more than 30 years after nuclear probes, the largest activity of 137Cs is still within 10 cm of the upper layer of the soil. This result confirms that the penetration of 137Cs in soil is a very slow process. Experimental results were compared with two different Green functions and no major differences were found between them. While both functions fit experimental data well in the upper layer of soil, the fitting is not so good in deeper layers. Although the curves obtained by these two functions are very close to each other, there are some differences in the values of parameters acquired by them. PMID:15388151

  13. Multicolored Vertical Silicon Nanowires

    SciTech Connect

    Seo, Kwanyong; Wober, Munib; Steinvurzel, P.; Schonbrun, E.; Dan, Yaping; Ellenbogen, T.; Crozier, K. B.

    2011-04-13

    We demonstrate that vertical silicon nanowires take on a surprising variety of colors covering the entire visible spectrum, in marked contrast to the gray color of bulk silicon. This effect is readily observable by bright-field microscopy, or even to the naked eye. The reflection spectra of the nanowires each show a dip whose position depends on the nanowire radii. We compare the experimental data to the results of finite difference time domain simulations to elucidate the physical mechanisms behind the phenomena we observe. The nanowires are fabricated as arrays, but the vivid colors arise not from scattering or diffractive effects of the array, but from the guided mode properties of the individual nanowires. Each nanowire can thus define its own color, allowing for complex spatial patterning. We anticipate that the color filter effect we demonstrate could be employed in nanoscale image sensor devices.

  14. Summer Session: A Time for Innovation

    ERIC Educational Resources Information Center

    Mola, Monty

    2013-01-01

    Summer is almost here (at least for those of us who teach semesters). Many of us are taking a well-deserved break to spend time with our families, conduct research, travel, and myriad other activities. Some of us, however, will be teaching summer school. For those of us lucky enough to be teaching this summer, we have one suggestion: Be bold!…

  15. Close the Achievement Gap with Summer Learning

    ERIC Educational Resources Information Center

    Huggins, Gary

    2012-01-01

    Summer vacation from school can bring afternoons at the swimming pool, family vacations, and maybe a spirit-filled summer camp that ignites a passion for art or rock climbing. But for many children, summer also means setbacks in learning that take a tremendous toll on teaching and student performance over time. PTA leaders can make a vital…

  16. Finding Funds to Move Summer Learning Forward

    ERIC Educational Resources Information Center

    Seidel, Bob

    2015-01-01

    Summer learning loss creates a permanent drag on the US education system. With the generous support of the Charles Stewart Mott Foundation, the National Summer Learning Association (NSLA) developed "Moving Summer Learning Forward: A Strategic Roadmap for Funding in Tough Times" to provide out-of-school time programs, school districts,…

  17. Direct Observation of Ultralow Vertical Emittance using a Vertical Undulator

    SciTech Connect

    Wootton, Kent

    2015-09-17

    In recent work, the first quantitative measurements of electron beam vertical emittance using a vertical undulator were presented, with particular emphasis given to ultralow vertical emittances [K. P. Wootton, et al., Phys. Rev. ST Accel. Beams, 17, 112802 (2014)]. Using this apparatus, a geometric vertical emittance of 0.9 #6;± 0.3 pm rad has been observed. A critical analysis is given of measurement approaches that were attempted, with particular emphasis on systematic and statistical uncertainties. The method used is explained, compared to other techniques and the applicability of these results to other scenarios discussed.

  18. Observation of Picometer Vertical Emittance with a Vertical Undulator

    NASA Astrophysics Data System (ADS)

    Wootton, K. P.; Boland, M. J.; Dowd, R.; Tan, Y.-R. E.; Cowie, B. C. C.; Papaphilippou, Y.; Taylor, G. N.; Rassool, R. P.

    2012-11-01

    Using a vertical undulator, picometer vertical electron beam emittances have been observed at the Australian Synchrotron storage ring. An APPLE-II type undulator was phased to produce a horizontal magnetic field, which creates a synchrotron radiation field that is very sensitive to the vertical electron beam emittance. The measured ratios of undulator spectral peak heights are evaluated by fitting to simulations of the apparatus. With this apparatus immediately available at most existing electron and positron storage rings, we find this to be an appropriate and novel vertical emittance diagnostic.

  19. Variation in winter snowpack depth and duration influences summer soil respiration in a subalpine meadow

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

    Subalpine meadows in the Sierra Nevada rely on the depth and duration of the winter snowpack to supply ample water to restore the water table in the meadow during the spring snowmelt. This study examines the role that interannual variability in the winter snowpack plays in the overall rate of summer soil respiration along a hydrologic gradient in a subalpine meadow. Carbon dioxide efflux from the meadow was measured from June through September in 2011 and 2012 using soil collars and a LICOR 8100A infrared gas analyzer. Preliminary results show that soil respiration rates are influenced by the hydrologic gradient across the meadow, with drier regions peaking earlier in the summer as compared to wetter regions. We also show that high snowpack years can suppress soil respiration in the meadow until late in the summer season as compared to low snowpack years, where soil respiration peaks early in the summer.

  20. Summer North Atlantic Oscillation: decadal change, impact, and possible mechanisms

    NASA Astrophysics Data System (ADS)

    Sun, J.

    2010-12-01

    Summer North Atlantic Oscillation: decadal change, impact, and possible mechanisms Jianqi Sun, Huijun Wang, and Wei Yuan Nansen-Zhu International Research Centre (NZC), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China. Email: sunjq@mail.iap.ac.cn It is well known that the North Atlantic Oscillation (NAO) is strong in winter, so most previous studies focused on the NAO in winter time. However, actually the NAO is also one of the teleconnection patterns that have a year-round presence. For example, some studies have indicated that the summer North Atlantic Oscillation (SNAO) is still a dominant pattern over the North Atlantic region. So it is of importance to investigate the SNAO’s variability and influences. Our recent studies revealed that the summer (SNAO) experienced a significant decadal change around the late 1970s, with the southern action center located farther eastward after the late 1970s as compared to before. Such decadal change of the SNAO pattern altered its relationship with the Northern Hemispheric summer climate. In the period before the late 1970s, the connection of the SNAO on the Northern Hemispheric land surface air temperature is weak, but after that time the impact of the SNAO is significantly enhanced. Our further analysis indicated that the decadal change of the SNAO pattern is to some extend attributed to the decadal variability of the Mediterranean-Black Sea (MBS) sea surface temperature (SST). In 1951-1975, the variability of the MBS SST is quite weak, but in 1978-2002 it becomes more active. The active MBS SST can enhance the interaction between the sea and its overlying atmosphere, thus strengthening the activity of the east part of the SNAO southern center after the late 1970s and consequently producing an eastward SNAO southern center shift. This observational analysis result is further confirmed by sensitivity experiments. Besides the MBS SST, the decadal variability of the tropical Atlantic SST

  1. Mapping High Latitude Gravity Wave Amplitudes over Antarctica during Summer

    NASA Astrophysics Data System (ADS)

    Badenhausen, P.; Millan, R. M.; Gerrard, A. J.

    2015-12-01

    Appropriate inclusion of gravity wave amplitudes into general circulation models is required to get accurate atmospheric circulation characteristics. However, high latitude gravity wave amplitudes are particularly difficult to obtain due to the challenging experimental and logistical constraints in these regions. In this study, we present gravity wave climatology of high latitudes during austral summer conditions over the Antarctic continent. These data were obtained using high-resolution GPS measurements aboard long duration high altitude balloon flights that were flown as part of the NASA Balloon Array for Radiation-belt Relativistic Electron Losses (BARREL) mission in December 2013-February 2014 and December 2012-February 2013. The results show increased gravity wave activity along the coast of the Antarctic continent, particularly over the Peninsula and Halley Bay, whereas at higher latitudes, particularly over regions near the South Pole, gravity wave amplitudes decrease substantially. Through use of horizontal winds data, we obtained measurements of the vertical transport of horizontal momentum fluxes, which were unusually high for the summer high latitude lower stratosphere. Such unique measurements as these are immediately applicable to understanding of upwelling in the summer middle atmosphere as well as to the formation of overlaying mesospheric clouds formation.

  2. On the relationship between Indian Ocean Dipole-Indian Summer Monsoon and Summer North Atlantic Oscillation

    NASA Astrophysics Data System (ADS)

    Sundaram, S.; Stenchikov, G. L.

    2013-12-01

    Using 60 years of observed and re-analysis data sets a link between positive Indian Ocean dipole (PIOD), Indian Summer Monsoon (ISM) and Summer North Atlantic Oscillation (SNAO) is proposed. When positive IOD years occur independently without Elnino the presence of positive phase of SNAO is noticed. In such cases over the Atlantic region the centers of action associated with SNAO is shifted northward leading to the change in the mean position of Atlantic jet and storm tracks. Persistence of storm tracks at the new location amounts to a stationary waves, which have a barotropic structure in the vertical. Therefore, the temperature anomalies associated with the stationary wave influences the Tropospheric Temperature (TT), which is clearly seen in the average TT anomaly, showing warming over southern Eurasia and India. This affects the north-south TT gradient in the monsoon region and influences the ISM (Goswami et al., 2006). Concurrently the local Hadley cell associated with PIOD strengthens and enhances the anomalous subsidence over the Mediterranean/Sahara region which in turn strengthens the Azores high and the hence the SNAO itself. Thus the combined influence of PIOD and SNAO produces a positive feed back mechanism for ISM. On the other hand most of the PIOD years co-occurring with Elnino years are accompanied by the negative phase of SNAO. The analysis of the atmospheric circulation clearly indicates the Pacific North American (PNA) type pattern, which negatively influence the SNAO (Huang et al., 1998). This is consistent with the observation that ISM is not enhanced in all PIOD years. The analysis of 60 years historic sea surface temperature runs with the high resolution atmospheric model shows that the model is able to reproduce these teleconnections.

  3. Nile behaviour and Late Palaeolithic humans in Upper Egypt during the Late Pleistocene

    NASA Astrophysics Data System (ADS)

    Vermeersch, Pierre M.; Van Neer, Wim

    2015-12-01

    , even in late summer.

  4. Continental Summer Dryness in the New GFDL Climate Model

    NASA Astrophysics Data System (ADS)

    Findell, K. L.; Delworth, T. L.

    2003-12-01

    In this work, we revisit the question of continental summer drying in a doubled-CO2 environment using the latest version of the Geophysical Fluid Dynamics Labs (GFDL) model of the atmosphere and land surface coupled to a mixed layer (slab) ocean. Two highly significant differences between this new model and earlier GFDL models are the increased resolution (2.5° longitude x 2.0° latitude and 17 vertical levels vs. 3.75° longitude x 2.25° latitude and 14 vertical levels for the previous model), and the inclusion of both a diurnal cycle and a seasonal cycle (the earlier models only had the latter). Results from these earlier models showed, among other things, an increase in wintertime rainfall over most mid-latitude continental regions when CO2 is doubled, an earlier snowmelt season and onset of springtime evaporation, and a higher ratio of evaporation to precipitation in summer. These factors led to large-scale increases in soil moisture in winter and decreases in summer in mid-latitudes in the doubled-CO2 experiment. The new model shows similar results, and the processes discussed above are important in this model as well. In addition, we find that changes in atmospheric circulation are playing an important role in regional hydrologic changes, particularly in Western Europe. Additional experiments have been run to isolate the feedback from the land surface from the role of the atmospheric changes caused by the doubling of CO2. These simulations show that the CO2 impacts alone explain the majority of the results, while the land surface feedbacks serve to strengthen the observed signals. Experiments to isolate the role of the CO2-induced changes to the sea surface temperature on the atmospheric circulation are currently underway.

  5. Inversions of vertical transfers between the Atlantic and Mediterranean waters by meteorological forcing in the Strait of Gibraltar

    NASA Astrophysics Data System (ADS)

    Sánchez-Román, Antonio; Jordà, Gabriel; Sannino, Gianmaria; Gomis, Damià

    2014-05-01

    The Strait of Gibraltar is the scenario of a very energetic baroclinic exchange between Atlantic and Mediterranean waters: fresh and warm Atlantic waters enter into the Mediterranean while salty and cold Mediterranean waters outflow to the Atlantic. Those water fluxes fluctuate at different timescales, the most important of which is the semidiurnal one. Other less important but non-negligible source of variability is the meteorological forcing that induces fluctuations in the range of few days of period and the seasonal and interannual variations. Moreover, the two-way exchange is influenced by vertical transfers of heat, salt and mass between the Mediterranean and Atlantic waters during their passage through the Strait. This fact modifies their TS properties having impact on the net heat and salt exchanges of the Mediterranean Sea with the global ocean. The aim of this work is to analyse the temporal variability of vertical transfers between the Atlantic and Mediterranean waters along their path through the Strait of Gibraltar, with emphasis on the reversal episodes of those vertical transports along the Strait. To do that we analyse the outputs of a numerical simulation covering the entire Mediterranean basin (1/6º of spatial resolution) with enhanced resolution in the area of the Strait (1/200º). Another special feature of this model is that it was only forced through the specification of both the atmospheric pressure and heat & water fluxes at the sea surface so, it does not include the forcing exerted by tides. Tides were excluded from the experiment to further investigate the effects of a realistic atmospheric forcing over the mean flow. The vertical fluxes between layers present enhanced fluctuations between late autumn and wintertime for all years investigated. On the contrary, minimum values are obtained in summer. This result is ascribed to the sensitivity of the horizontal exchange flows to the passage of atmospheric systems over the Mediterranean

  6. ON-LINE TOOLS FOR PROPER VERTICAL POSITIONING OF VERTICAL SAMPLING INTERVALS DURING SITE ASSESSMENT

    EPA Science Inventory

    This presentation presents on-line tools for proper vertical positioning of vertical sampling intervals during site assessment. Proper vertical sample interval selection is critical for generate data on the vertical distribution of contamination. Without vertical delineation, th...

  7. Costs and benefits of late nesting in cliff swallows.

    PubMed

    Brown, Charles R; Roche, Erin A; O'Brien, Valerie A

    2015-02-01

    Many organisms of temperate latitudes exhibit declines in reproductive success as the breeding season advances. Experiments can delay the onset of reproduction for early breeders to investigate the consequences of late nesting, but it is rarely possible to observe a distinct second round of nesting in species that normally nest only once. The colonial cliff swallow (Petrochelidon pyrrhonota) is a migratory songbird that has a relatively short breeding season in the western Great Plains, USA, with birds rarely nesting late in the summer. Previous work suggested that ectoparasitism is a primary reason why reproductive success in this species declines over the summer. At colony sites where nests were fumigated to remove ectoparasitic swallow bugs (Oeciacus vicarius), cliff swallows frequently undertook a distinct round of late nesting after previously fledging young that year. Mark-recapture revealed that late-nesting pairs at these colonies produced fewer offspring that survived to the next breeding season, and that survival of late-nesting adults was lower during the next year, relative to pairs nesting earlier in the season. These reproductive costs applied in the absence of ectoparasites and likely reflect other environmental costs of late nesting such as seasonal declines in food availability or a delayed start of fall migration. Despite the costs, the estimated fitness for perennial early-and-late nesters in the absence of ectoparasites was equivalent to that of birds that nested only early in the season. The collective disadvantages of late nesting likely constrain most cliff swallows to raising a single brood in the middle latitudes of North America.

  8. 4. VIEW OF VERTICAL BORING MACHINE. (Bullard) Vertical turning lathe ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. VIEW OF VERTICAL BORING MACHINE. (Bullard) Vertical turning lathe (VTL). Machining the fixture for GE Turboshroud. G.S. O'Brien, operator. - Juniata Shops, Machine Shop No. 1, East of Fourth Avenue at Third Street, Altoona, Blair County, PA

  9. Late-term abortion.

    PubMed

    Epner, J E; Jonas, H S; Seckinger, D L

    1998-08-26

    Recent proposed federal legislation banning certain abortion procedures, particularly intact dilatation and extraction, would modify the US Criminal Code such that physicians performing these procedures would be liable for monetary and statutory damages. Clarification of medical procedures is important because some of the procedures used to induce abortion prior to viability are identical or similar to postviability procedures. This article reviews the scientific and medical information on late-term abortion and late-term abortion techniques and includes data on the prevalence of late-term abortion, abortion-related mortality and morbidity rates, and legal issues regarding fetal viability and the balance of maternal and fetal interests. According to enacted American Medical Association (AMA) policy, the use of appropriate medical terminology is critical in defining late-term abortion procedures, particularly intact dilatation and extraction, which is a variant of but distinct from dilatation and evacuation. The AMA recommends that the intact dilatation and extraction procedure not be used unless alternative procedures pose materially greater risk to the woman and that abortions not be performed in the third trimester except in cases of serious fetal anomalies incompatible with life. Major medical societies are urged to collaborate on clinical guidelines on late-term abortion techniques and circumstances that conform to standards of good medical practice. More research on the advantages and disadvantages of specific abortion procedures would help physicians make informed choices about specific abortion procedures. Expanded ongoing data surveillance systems estimating the prevalence of abortion are also needed. PMID:9728645

  10. Late-term abortion.

    PubMed

    Epner, J E; Jonas, H S; Seckinger, D L

    1998-08-26

    Recent proposed federal legislation banning certain abortion procedures, particularly intact dilatation and extraction, would modify the US Criminal Code such that physicians performing these procedures would be liable for monetary and statutory damages. Clarification of medical procedures is important because some of the procedures used to induce abortion prior to viability are identical or similar to postviability procedures. This article reviews the scientific and medical information on late-term abortion and late-term abortion techniques and includes data on the prevalence of late-term abortion, abortion-related mortality and morbidity rates, and legal issues regarding fetal viability and the balance of maternal and fetal interests. According to enacted American Medical Association (AMA) policy, the use of appropriate medical terminology is critical in defining late-term abortion procedures, particularly intact dilatation and extraction, which is a variant of but distinct from dilatation and evacuation. The AMA recommends that the intact dilatation and extraction procedure not be used unless alternative procedures pose materially greater risk to the woman and that abortions not be performed in the third trimester except in cases of serious fetal anomalies incompatible with life. Major medical societies are urged to collaborate on clinical guidelines on late-term abortion techniques and circumstances that conform to standards of good medical practice. More research on the advantages and disadvantages of specific abortion procedures would help physicians make informed choices about specific abortion procedures. Expanded ongoing data surveillance systems estimating the prevalence of abortion are also needed.

  11. Doppler-shifting effects on frequency spectra of gravity waves observed near the summer mesopause at high latitude

    NASA Technical Reports Server (NTRS)

    Fritts, David C.; Wang, Ding-Yi

    1991-01-01

    Results are presented of radar observations of horizontal and vertical velocities near the summer mesopause at Poker Flat (Alaska), showing that the observed vertical velocity spectra were influenced strongly by Doppler-shifting effects. The horizontal velocity spectra, however, were relatively insensitive to horizontal wind speed. The observed spectra are compared with predicted spectra for various models of the intrinsic motion spectrum and degrees of Doppler shifting.

  12. A simple model for the interaction between vertical eddy heat fluxes and static stability

    NASA Technical Reports Server (NTRS)

    Gutowski, W. J., Jr.

    1985-01-01

    A numerical model for studying the interaction of vertical eddy heat fluxes and vertical temperature structure in midlatitude regions is described. The temperature profile for the model was derived from calculations of the equilibrium among heating rates in simplified representations of large-scale vertical eddy heat flux, moist convection and radiation. An eddy flux profile is calculated based on the quasi-geostrophic, liner baroclinic instability of a single wave. Model equilibrium states for summer and winter conditions are compared with observations, and the results are discussed in detail.

  13. Convective cloud top vertical velocity estimated from geostationary satellite rapid-scan measurements

    NASA Astrophysics Data System (ADS)

    Hamada, Atsushi; Takayabu, Yukari N.

    2016-05-01

    We demonstrate that the rate of development of cumulus clouds, as inferred from the so-called geostationary satellite "rapid-scan" measurements, is a good proxy for convective cloud top vertical velocity related to deep convective clouds. Convective cloud top vertical velocity is estimated from the decreasing rate of infrared brightness temperature observed by the Multi-functional Transport SATellite-1R (MTSAT-1R) over the ocean south of Japan during boreal summer. The frequency distribution of the estimated convective cloud top vertical velocity at each height is shown to distribute lognormally, and it is consistent with the statistical characteristics of direct measurements acquired in previous studies.

  14. Late archaic settlement systems in the northern Rio Grande

    SciTech Connect

    Vierra, Bradley J.

    2003-01-01

    Last year at these meetings I proposed a possible seasonal transhumance pattern for the Late Archaic in the northern Rio Grande region. This pattern involved the movement of groups from the lowland juniper-savanna grasslands in the early summer, to the upland ponderosa pindmixed conifer forests in the mid to late summer, and then back down to the piiion-juniper woodlands during the fall. The Rio Grande Valley was also used for winter habitation sites. Following on this research, I take the next step by studying the inter-assemblage variability represented in a sample of open-air sites located within each of these vegetation communities. The results indicate that there are significant differences in reduction tactics represented between valley habitation vs., upland campsites, and that these site sites are linked together by obsidian procurement patterns.

  15. Summer faculty fellowship program, 1984

    NASA Technical Reports Server (NTRS)

    Spencer, J. H. (Compiler)

    1984-01-01

    Since 1964, the National Aeronautics and Space Administration (NASA) has supported a program of summer faculty fellowships for engineering and science educators. In a series of collaborations between NASA research and development centers and nearby universities, engineering faculty members spend 10 or 11 weeks working with professional peers on research. The Summer Faculty Program Committee of the American Society of Engineering Education supervises the programs. Objectives: (1) to further the professional knowledge of a qualified between participants and NASA; (3) to enrich and refresh the research and teaching activities of participants institutions; and (4) to contribute to the research objectives of the NASA center. Program Description: College or university faculty members will be appointed as research fellows to spend 10 weeks in cooperative research and study at the NASA-Langley Research Center. The fellow will devote approximately 90 percent of the time to a research problem and the remaining time to a study program. The study program will consist of lectures and seminars on topics of general interest or that are directly relevant to the fellow's research project. The lecturers and seminar leaders will be distinguished scientists and engineers from NASA, education, or industry.

  16. Average vertical and zonal F region plasma drifts over Jicamarca

    SciTech Connect

    Fejer, B.G.; Gonzalez, S.A. ); de Paula, E.R. Utah State Univ., Logan ); Woodman, R.F. )

    1991-08-01

    The seasonal averages of the equatorial F region vertical and zonal plasma drifts are determined using extensive incoherent scatter radar observations from Jicamarca during 1968-1988. The late afternoon and nighttime vertical and zonal drifts are strongly dependent on the 10.7-cm solar flux. The authors show that the evening prereversal enhancement of vertical drifts increases linearly with solar flux during equinox but tends to saturate for large fluxes during southern hemisphere winter. They examine in detail, for the first time, the seasonal variation of the zonal plasma drifts and their dependence on solar flux and magnetic activity. The seasonal effects on the zonal drifts are most pronounced in the midnight-morning sector. The nighttime eastward drifts increase with solar flux for all seasons but decrease slightly with magnetic activity. The daytime westward drifts are essentially independent of season, solar cycle, and magnetic activity.

  17. South Asian Summer Monsoon in CMIP5 GCMs

    NASA Astrophysics Data System (ADS)

    Ashfaq, M.; Rastogi, D.; Touma, D. E.

    2012-12-01

    Many Global Climate Models (GCMs) in the IPCC Fourth Assessment Report (AR4) suffered from substantial biases in their simulation of processes that govern summer monsoon dynamics in South Asia, leading to uncertainties in the simulation of monsoon response to future increases in greenhouse forcing. In order to test the ability of the current generation of GCMs that are part of the Coupled Model Inter-comparison Project Phase 5 (CMIP5) in the simulation of South Asian summer monsoon dynamics, we analyze the outputs from their historic simulations that correspond to 1970-1999 period. The analyses include the comparison of multiple monsoon indices including those representing monsoon onset, local circulations and global teleconnections, at seasonal, intra-seasonal and inter-annual time scales. We find that most of the GCMs are unable to simulate the timing of the summer monsoon onset over land, leading to substantial biases in seasonal precipitation means and variability, and intra-seasonal precipitation distribution. These errors are partly due to the fact that the majority of the GCMs exhibit a shift in the annual monsoon cycle with most of them exhibiting a precipitation peak in August in contrast to the observed peak in July, and that most of the GCMs substantially underestimate the strength of meridional troposhepric temperature gradient and vertical easterly shear during the summer season. We also find many models with low skill in the simulation of intra-seasonal temperature variability, and monsoon connection with local Hadley circulation and ENSO variability. These results have important implications for the reliability of future climate projections and impact assessments over South Asia.

  18. Late Mitochondrial Acquisition, Really?

    PubMed Central

    Degli Esposti, Mauro

    2016-01-01

    This article provides a timely critique of a recent Nature paper by Pittis and Gabaldón that has suggested a late origin of mitochondria in eukaryote evolution. It shows that the inferred ancestry of many mitochondrial proteins has been incorrectly assigned by Pittis and Gabaldón to bacteria other than the aerobic proteobacteria from which the ancestor of mitochondria originates, thereby questioning the validity of their suggestion that mitochondrial acquisition may be a late event in eukaryote evolution. The analysis and approach presented here may guide future studies to resolve the true ancestry of mitochondria. PMID:27289097

  19. Lateness to School Remediation Game

    ERIC Educational Resources Information Center

    Ugwuegbulam, Charles N.; Ibrahim, Haj. Naheed

    2015-01-01

    Primary and secondary school in Nigeria encourage punctuality to school yet a good number of the learners came late to school. This is especially true in the case of day students. Learners who come late to school are usually punished in one way or the other yet the lateness to school phenomenon still persist. Lateness to school behaviour affects…

  20. Latitude and longitude vertical disparities.

    PubMed

    Read, Jenny C A; Phillipson, Graeme P; Glennerster, Andrew

    2009-12-09

    The literature on vertical disparity is complicated by the fact that several different definitions of the term "vertical disparity" are in common use, often without a clear statement about which is intended or a widespread appreciation of the properties of the different definitions. Here, we examine two definitions of retinal vertical disparity: elevation-latitude and elevation-longitude disparities. Near the fixation point, these definitions become equivalent, but in general, they have quite different dependences on object distance and binocular eye posture, which have not previously been spelt out. We present analytical approximations for each type of vertical disparity, valid for more general conditions than previous derivations in the literature: we do not restrict ourselves to objects near the fixation point or near the plane of regard, and we allow for non-zero torsion, cyclovergence, and vertical misalignments of the eyes. We use these expressions to derive estimates of the latitude and longitude vertical disparities expected at each point in the visual field, averaged over all natural viewing. Finally, we present analytical expressions showing how binocular eye position-gaze direction, convergence, torsion, cyclovergence, and vertical misalignment-can be derived from the vertical disparity field and its derivatives at the fovea.

  1. The Gains from Vertical Scaling

    ERIC Educational Resources Information Center

    Briggs, Derek C.; Domingue, Ben

    2013-01-01

    It is often assumed that a vertical scale is necessary when value-added models depend upon the gain scores of students across two or more points in time. This article examines the conditions under which the scale transformations associated with the vertical scaling process would be expected to have a significant impact on normative interpretations…

  2. Scale Shrinkage in Vertical Equating.

    ERIC Educational Resources Information Center

    Camilli, Gregory; And Others

    1993-01-01

    Three potential causes of scale shrinkage (measurement error, restriction of range, and multidimensionality) in item response theory vertical equating are discussed, and a more comprehensive model-based approach to establishing vertical scales is described. Test data from the National Assessment of Educational Progress are used to illustrate the…

  3. Kinematic and diabatic vertical velocity climatologies from a chemistry climate model

    NASA Astrophysics Data System (ADS)

    Marinke Hoppe, Charlotte; Ploeger, Felix; Konopka, Paul; Müller, Rolf

    2016-05-01

    The representation of vertical velocity in chemistry climate models is a key element for the representation of the large-scale Brewer-Dobson circulation in the stratosphere. Here, we diagnose and compare the kinematic and diabatic vertical velocities in the ECHAM/Modular Earth Submodel System (MESSy) Atmospheric Chemistry (EMAC) model. The calculation of kinematic vertical velocity is based on the continuity equation, whereas diabatic vertical velocity is computed using diabatic heating rates. Annual and monthly zonal mean climatologies of vertical velocity from a 10-year simulation are provided for both kinematic and diabatic vertical velocity representations. In general, both vertical velocity patterns show the main features of the stratospheric circulation, namely, upwelling at low latitudes and downwelling at high latitudes. The main difference in the vertical velocity pattern is a more uniform structure for diabatic and a noisier structure for kinematic vertical velocity. Diabatic vertical velocities show higher absolute values both in the upwelling branch in the inner tropics and in the downwelling regions in the polar vortices. Further, there is a latitudinal shift of the tropical upwelling branch in boreal summer between the two vertical velocity representations with the tropical upwelling region in the diabatic representation shifted southward compared to the kinematic case. Furthermore, we present mean age of air climatologies from two transport schemes in EMAC using these different vertical velocities and analyze the impact of residual circulation and mixing processes on the age of air. The age of air distributions show a hemispheric difference pattern in the stratosphere with younger air in the Southern Hemisphere and older air in the Northern Hemisphere using the transport scheme with diabatic vertical velocities. Further, the age of air climatology from the transport scheme using diabatic vertical velocities shows a younger mean age of air in the

  4. Changes in Susceptibility to Heat During the Summer: A Multicountry Analysis

    PubMed Central

    Gasparrini, Antonio; Guo, Yuming; Hashizume, Masahiro; Lavigne, Eric; Tobias, Aurelio; Zanobetti, Antonella; Schwartz, Joel D.; Leone, Michela; Michelozzi, Paola; Kan, Haidong; Tong, Shilu; Honda, Yasushi; Kim, Ho; Armstrong, Ben G.

    2016-01-01

    Few studies have examined the variation in mortality risk associated with heat during the summer. Here, we apply flexible statistical models to investigate the issue by using a large multicountry data set. We collected daily time-series data of temperature and mortality from 305 locations in 9 countries, in the period 1985–2012. We first estimated the heat-mortality relationship in each location with time-varying distributed lag non-linear models, using a bivariate spline to model the exposure-lag-response over lag 0–10. Estimates were then pooled by country through multivariate meta-analysis. Results provide strong evidence of a reduction in risk over the season. Relative risks for the 99th percentile versus the minimum mortality temperature were in the range of 1.15–2.03 in early summer. In late summer, the excess was substantially reduced or abated, with relative risks in the range of 0.97–1.41 and indications of wider comfort ranges and higher minimum mortality temperatures. The attenuation is mainly due to shorter lag periods in late summer. In conclusion, this multicountry analysis suggests a reduction of heat-related mortality risk over the summer, which can be attributed to several factors, such as true acclimatization, adaptive behaviors, or harvesting effects. These findings may have implications on public health policies and climate change health impact projections. PMID:27188948

  5. Changes in Susceptibility to Heat During the Summer: A Multicountry Analysis.

    PubMed

    Gasparrini, Antonio; Guo, Yuming; Hashizume, Masahiro; Lavigne, Eric; Tobias, Aurelio; Zanobetti, Antonella; Schwartz, Joel D; Leone, Michela; Michelozzi, Paola; Kan, Haidong; Tong, Shilu; Honda, Yasushi; Kim, Ho; Armstrong, Ben G

    2016-06-01

    Few studies have examined the variation in mortality risk associated with heat during the summer. Here, we apply flexible statistical models to investigate the issue by using a large multicountry data set. We collected daily time-series data of temperature and mortality from 305 locations in 9 countries, in the period 1985-2012. We first estimated the heat-mortality relationship in each location with time-varying distributed lag non-linear models, using a bivariate spline to model the exposure-lag-response over lag 0-10. Estimates were then pooled by country through multivariate meta-analysis. Results provide strong evidence of a reduction in risk over the season. Relative risks for the 99th percentile versus the minimum mortality temperature were in the range of 1.15-2.03 in early summer. In late summer, the excess was substantially reduced or abated, with relative risks in the range of 0.97-1.41 and indications of wider comfort ranges and higher minimum mortality temperatures. The attenuation is mainly due to shorter lag periods in late summer. In conclusion, this multicountry analysis suggests a reduction of heat-related mortality risk over the summer, which can be attributed to several factors, such as true acclimatization, adaptive behaviors, or harvesting effects. These findings may have implications on public health policies and climate change health impact projections.

  6. Changes in Susceptibility to Heat During the Summer: A Multicountry Analysis.

    PubMed

    Gasparrini, Antonio; Guo, Yuming; Hashizume, Masahiro; Lavigne, Eric; Tobias, Aurelio; Zanobetti, Antonella; Schwartz, Joel D; Leone, Michela; Michelozzi, Paola; Kan, Haidong; Tong, Shilu; Honda, Yasushi; Kim, Ho; Armstrong, Ben G

    2016-06-01

    Few studies have examined the variation in mortality risk associated with heat during the summer. Here, we apply flexible statistical models to investigate the issue by using a large multicountry data set. We collected daily time-series data of temperature and mortality from 305 locations in 9 countries, in the period 1985-2012. We first estimated the heat-mortality relationship in each location with time-varying distributed lag non-linear models, using a bivariate spline to model the exposure-lag-response over lag 0-10. Estimates were then pooled by country through multivariate meta-analysis. Results provide strong evidence of a reduction in risk over the season. Relative risks for the 99th percentile versus the minimum mortality temperature were in the range of 1.15-2.03 in early summer. In late summer, the excess was substantially reduced or abated, with relative risks in the range of 0.97-1.41 and indications of wider comfort ranges and higher minimum mortality temperatures. The attenuation is mainly due to shorter lag periods in late summer. In conclusion, this multicountry analysis suggests a reduction of heat-related mortality risk over the summer, which can be attributed to several factors, such as true acclimatization, adaptive behaviors, or harvesting effects. These findings may have implications on public health policies and climate change health impact projections. PMID:27188948

  7. Centropages behaviour: Swimming and vertical migration

    NASA Astrophysics Data System (ADS)

    Alcaraz, Miguel; Saiz, Enric; Calbet, Albert

    2007-02-01

    The evolutionary success of any species living in a variable environment depends on its capacity to enhance the probability of finding food and mates, and escaping predators. In the case of copepods of the genus Centropages, as in all planktonic copepods, their swimming behaviour is closely tied to these vital aspects, and shows a high degree of plasticity and adaptive capacity. Swimming mechanisms of Centropages change radically during development, mainly in the transition between naupliar stages to the 1st copepodite; nauplii do not produce feeding currents, whereas copepodites do. Adults and late developmental stages of C. typicus, C. hamatus and C. velificatus spend most of the time in slow swimming and resting breaks, with occasional and brief fast swimming (escape reactions) and grooming events. Slow swimming is closely related to the creation of feeding currents, and results from the beating of the cephalic appendages in a “fling and clap” manner. The proportion of time allocated to the different swimming activities depends on sensory cues like type and concentration of food, presence of potential mates, light intensity, hydrodynamic flow, etc. The responses of Centropages to changes in flow velocity fluctuations (small-scale turbulence) are similar to the escape responses (fast swimming) triggered by the presence of potential predators. Centropages generally have standard nocturnal vertical migration patterns involving considerable vertical displacements. This behaviour is closely related to the narrow spectral sensitivity and the low intensity threshold of the genus, and has important consequences for the active vertical transport of matter and energy. The variety of responses of Centropages to environmental changes, and in general all the aspects related to its swimming behaviour seem to be controlled by the trade-off between energetic gains (food intake), losses (swimming energy expenditure), and predation risk. Behavioural plasticity and adaptation

  8. Classification of typical summer rainfall patterns in the East China monsoon region and their association with the East Asian summer monsoon

    NASA Astrophysics Data System (ADS)

    Yang, Liu; Zhao, Junhu; Feng, Guolin

    2016-06-01

    In this study, the summer rainfall patterns in the East China monsoon region during 1951-2015 were objectively classified into four typical categories: the northern China rainfall pattern (NCP), the intermediate rainfall pattern (IRP), the Yangtze River rainfall pattern (YRP), and the South China rainfall pattern (SCP). The periods of the four patterns show significant decadal characteristics. The NCP occurred mainly between the late 1950s and the early 1980s, and the IRP in the late 1950s to the early 1970s and the 2000s. The YRP occurred mainly between the 1980s and the 1990s, and the SCP between the mid-1990s and the early 21st century. The relationship between the East Asian summer monsoon index (EASM I WF) and the four rainfall patterns was comparatively analyzed. The results confirmed that the four rainfall patterns have obvious differences in the EASM. In the NCP, IRP, or SCP years, the EASM I WF primarily showed a positive phase and a strong summer monsoon; in the YRP years, the EASM I WF primarily showed a negative phase and a weak summer monsoon.

  9. The Onset of Early Season Rainfall and its Mid-Summer Cessation in the Caribbean.

    NASA Astrophysics Data System (ADS)

    Allen, T. L.; Mapes, B. E.

    2014-12-01

    The annual rainfall cycle for the Caribbean basin reveals a distinct bimodal pattern with peaks during the late spring and late summer months. A relative minimum during the mid-summer, known as the mid-summer drought (MSD) separates the early rainfall season (ERS) from the late rainfall season. Accumulated rainfall totals during the ERS appear as a quasi-stationary rain-belt stretching across the Caribbean from the southwest to the northeast. We place late spring rains in the Caribbean in context of other subtropical convergence zones in order to address the onset and cessation of the ERS while also offering an explanation of a Caribbean rain-belt pattern. Upper tropospheric westerlies, mid-tropospheric positive temperature advection, and moist low level poleward flow are the three primary ingredients that conspire to produce the first peak of the annual bimodal rain signal and the related Caribbean early season rain-belt. The MSD ensues as the primary ingredients weaken across the Caribbean and enhanced rainfall shifts north along the North Atlantic Convergence Zone (NACZ). Seasonal rainfall totals from the ERS through the MSD periods reveal a continuous rain-belt that extends from the Caribbean to the NACZ termed the Caribbean Atlantic Rain-belt (CAR-belt). The Car-belt is present in the long term mean, but has signs of interannual variability.

  10. North Polar Layers in Summer

    NASA Technical Reports Server (NTRS)

    2004-01-01

    15 October 2004 It is now early summer in the northern hemisphere on Mars, and this means that the ices of the north polar cap are in full retreat. Exposed from beneath seasonal frost are the eroded layers of what Mars scientists suspect are composed of a mixture of dust and ice (and in some layers, sand). This October 2004 Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows some of the north polar layers exposed on a moderately-dipping slope. The bright material at the top of the image is water ice frost; the triangular features are thought to be caused by wind erosion of the frost. This image is located near 87.1oN, 267.4oW, and covers an area about 3 km (1.9 mi) wide. Sunlight illuminates the scene from the lower left.

  11. Vertical bloch line memory

    NASA Technical Reports Server (NTRS)

    Katti, R.; Wu, J.; Stadler, H.

    1990-01-01

    Vertical Bloch Line (VBL) memory is a recently conceived, integrated, solid-state, block-access, VLSI memory which offers the potential of 1Gbit/sq cm real storage density, gigabit per second data rates, and sub-millisecond average access times simultaneously at relatively low mass, volume, and power values when compared to alternative technologies. VBL's are micromagnetic structures within magnetic domain walls which can be manipulated using magnetic fields from integrated conductors. The presence or absence of VBL pairs are used to store binary information. At present, efforts are being directed at developing a single-chip memory using 25Mbit/sq cm technology in magnetic garnet material which integrates, at a single operating point, the writing, storage, reading, and amplification functions needed in a memory. This paper describes the current design architecture, functional elements, and supercomputer simulation results which are used to assist the design process. The current design architecture uses three metal layers, two ion implantation steps for modulating the thickness of the magnetic layer, one ion implantation step for assisting propagation in the major line track, one NiFe soft magnetic layer, one CoPt hard magnetic layer, and one reflective Cr layer for facilitating magneto-optic observation of magnetic structure. Data are stored in a series of elongated magnetic domains, called stripes, which serve as storage sites for arrays of VBL pairs. The ends of these stripes are placed near conductors which serve as VBL read/write gates. A major line track is present to provide a source and propagation path for magnetic bubbles. Writing and reading, respectively, are achieved by converting magnetic bubbles to VBL's and vice versa. The output function is effected by stretching a magnetic bubble and detecting it magnetoresistively. Experimental results from the past design cycle created four design goals for the current design cycle. First, the bias field ranges

  12. Estimates of the seasonal mean vertical velocity fields of the extratropical Northern Hemisphere

    NASA Technical Reports Server (NTRS)

    White, G. H.

    1983-01-01

    Indirect methods are employed to estimate the wintertime and summertime mean vertical velocity fields of the extratropical Northern Hemisphere and intercomparisons are made, together with comparisons with mean seasonal patterns of cloudiness and precipitation. Twice-daily NMC operational analyses produced general circulation statistics for 11 winters and 12 summers, permitting calculation of the seasonal NMC averages for 6 hr forecasts, solution of the omega equation, integration of continuity equation downward from 100 mb, and solution of the thermodynamic energy equation in the absence of diabatic heating. The methods all yielded similar vertical velocity patterns; however, the magnitude of the vertical velocities could not be calculated with great accuracy. Orography was concluded to have less of an effect in summer than in winter, when winds are stronger.

  13. A quantitative study of the summer slide in science of elementary school students

    NASA Astrophysics Data System (ADS)

    Donovan, Giovanna Guadagno

    Concerned parents and educators agree children learn best when the rhythm of instruction is continuous with practice and application of skills. Long summer breaks may interrupt the flow of formal school learning leading some students to forget previous instruction. A review of the previous school work is generally required in the fall upon return from the summer vacation. Investigating summer vacation and equity issues, Jamar (1994) noted that more affluent students may "return to school in the fall with a considerable educational advantage over their less advantaged peers as a result of either additional school-related learning, or lower levels of forgetting, over the summer months (p. 1)". The population of 402 fifth grade students from a suburban New England school district participated in this study. The district administered the science subtest of the TerraNova 2 (TN2) assessment in late May 2007 (pre-test data) and in September 2007 (post-test data). These archived data, including gender and student socioeconomic status (SES) levels (as referenced by free or reduced lunch status), were analyzed for an ex-post facto causal comparison study to identify the phenomenon of summer slide in science of fifth graders enrolled in six elementary schools. The ANOVA statistical model was used calculating the repeated measures factor of time (pre/post summer vacation) on the science content area. Subsequent two-way ANOVAS, with one repeated-measures factor (time of testing) explored the existence of similar/different patterns by gender and by SES levels. Two questions guided this study. First, does the summer slide phenomenon exist in science education? Second, if the summer slide in science phenomenon exists in science education, then does SES impact it? Does the summer slide in science phenomenon differ between genders? Findings suggest that the summer slide phenomenon exists in science; SES and gender does not affect the overall science test scores. However, SES impacts

  14. Vertical plate motions in the West Siberian Basin

    NASA Astrophysics Data System (ADS)

    Vibe, Yulia; Clark, Stuart

    2015-04-01

    The West Siberian Basin is one of the world's largest sedimentary basins representing an important source of oil and gas. The Basin's history includes long periods of very slow subsidence coupled with periods of erosion and uplift. Despite that the Basin has been broadly explored the causes of these vertical motions are not yet understood. In this study we analyse the vertical motions by the means of backstripping. The new backstripping results refined by the paleo-water depth data give estimates of the subsidence and uplift rate. These results show a peculiar character of the vertical motions where the region of maximum subsidence migrated from the north to the south several times during the Basin's history. Such southward propagation of subsidence happened in the Late Jurassic, Aptian and in the Paleogene periods. The newly constrained local eustatic curve indicates that the Basin's vertical motions do not reflect the global sea level changes, but the more complicated tectonic processes. We put different data sets of the Basin's sediments and crust structure together with the new backstripping results in order to understand better the vertical motions and the processes underlying the irregular subsidence and uplift pattern of the West Siberian Basin

  15. Summertime, Summer Teens: Summer School Enrollment and the Youth Labor Force.

    ERIC Educational Resources Information Center

    Stringer, Tiffany

    2003-01-01

    Describes changes in how teenagers spend their summers and at the trends in summer school enrollment. Discusses teens' labor force participation and includes information about types of jobs, hours they work, wages, and teenage workers' rights. (JOW)

  16. Vertical axis wind turbine airfoil

    DOEpatents

    Krivcov, Vladimir; Krivospitski, Vladimir; Maksimov, Vasili; Halstead, Richard; Grahov, Jurij Vasiljevich

    2012-12-18

    A vertical axis wind turbine airfoil is described. The wind turbine airfoil can include a leading edge, a trailing edge, an upper curved surface, a lower curved surface, and a centerline running between the upper surface and the lower surface and from the leading edge to the trailing edge. The airfoil can be configured so that the distance between the centerline and the upper surface is the same as the distance between the centerline and the lower surface at all points along the length of the airfoil. A plurality of such airfoils can be included in a vertical axis wind turbine. These airfoils can be vertically disposed and can rotate about a vertical axis.

  17. Visualize Vertical Connectedness (Middle Ground).

    ERIC Educational Resources Information Center

    van Allen, Lanny

    1996-01-01

    Discusses the possibility of vertical connectedness in K-12 education through references to journal articles and the author's own reflections. Suggests that middle school teachers may be leaders in a movement toward eliminating redundancy and gaps between grade levels. (TB)

  18. Vertically scanned laser sheet microscopy.

    PubMed

    Dong, Di; Arranz, Alicia; Zhu, Shouping; Yang, Yujie; Shi, Liangliang; Wang, Jun; Shen, Chen; Tian, Jie; Ripoll, Jorge

    2014-01-01

    Laser sheet microscopy is a widely used imaging technique for imaging the three-dimensional distribution of a fluorescence signal in fixed tissue or small organisms. In laser sheet microscopy, the stripe artifacts caused by high absorption or high scattering structures are very common, greatly affecting image quality. To solve this problem, we report here a two-step procedure which consists of continuously acquiring laser sheet images while vertically displacing the sample, and then using the variational stationary noise remover (VSNR) method to further reduce the remaining stripes. Images from a cleared murine colon acquired with a vertical scan are compared with common stitching procedures demonstrating that vertically scanned light sheet microscopy greatly improves the performance of current light sheet microscopy approaches without the need for complex changes to the imaging setup and allows imaging of elongated samples, extending the field of view in the vertical direction.

  19. Horizontal and Vertical Line Designs.

    ERIC Educational Resources Information Center

    Johns, Pat

    2003-01-01

    Presents an art lesson in which students learn about the artist Piet Mondrian and create their own abstract artworks. Focuses on geometric shapes using horizontal and vertical lines. Includes background information about the artist. (CMK)

  20. Late Babylonian Astrology

    NASA Astrophysics Data System (ADS)

    Steele, John M.

    The last five centuries BC saw the development of several new forms of astrology in Babylonia. Key to these new astrological techniques was the invention of the zodiac in about 400 BC. These new forms of astrology include personal horoscopes, astral medicine, and the exploitation of geometrical relationships between the position of heavenly bodies. Several Late Babylonian astrological doctrines were later adopted within Greek astrology.

  1. Public Library YA Program Roundup. Fantastic Fiestas in the Library: Florida Teens Connect with Their Caribbean and Hispanic Roots; Read Any Good Movies Lately? Conducting YA Book and Movie Discussions; How To Survive a Summer Book Club: A Dialogue; What Do Teens Read in One Day? A Teen Read Week Log; Reading Rocks Music Revue; BookBusters! Spring Cleaning for Books, Teens, and Senior Citizens; Intergenerational Internet; Medieval Murder in the Library.

    ERIC Educational Resources Information Center

    Wexler, Sydna R.; Vaillancourt, Renee J.; Gillispie, Julie; Engdale, Adam; Lane, David; Welch, Rollie; Honnold, RoseMary; Hall, Tracie; Katz, Jeff; Bartlett, Linda

    2001-01-01

    These eight articles describe successful public library programs for teens. Highlights include programs emphasizing immigrants' cultures; viewing film adaptations from appropriate books; summer book discussion groups; using music to promote reading; using teen and senior citizen volunteers to help restore books; teens as computer tutors for other…

  2. Summer/winter stratification variability in the central part of the South Brazil Bight

    NASA Astrophysics Data System (ADS)

    Castro, Belmiro M.

    2014-10-01

    Analysis of the hydrographic data collected during seven consecutive high resolution summer/winter cruises in the central part of the South Brazil Bight off the coastal city of Ubatuba confirmed an observable summer/winter stratification variability of the shelf waters. The maximum bulk stratification occurred at mean distances of 85.6 km and 39.1 km from the coast in the austral winter and summer cruises, respectively. Estimates of the equivalent mixing power of the physical processes that increase or decrease the stratification in the inner and middle shelves showed that both shelf regions would be vertically well mixed were it not for buoyancy advection. In the inner shelf, buoyancy advection was associated with the along-shelf transport of low salinity waters originating from river runoff. In the middle shelf, buoyancy advection was due to the oceanic South Atlantic Central Water intrusions toward the coast.

  3. Greater effect of increasing shrub height on winter versus summer soil temperature

    NASA Astrophysics Data System (ADS)

    Paradis, Mélissa; Lévesque, Esther; Boudreau, Stéphane

    2016-08-01

    Shrub expansion is increasingly observed in arctic and subarctic environments. The development of shrub structure may significantly impact the abiotic environment at the local scale. Our objective was to reconstruct the development of the vertical structure of Betula glandulosa Michx. and to evaluate its effects on winter and summer soil temperature and on snow depth. Stratified sampling of the shrub revealed that shrub biomass distribution followed a similar pattern in stands of contrasting heights. Woody biomass was maximal in the lower stratum and relatively stable in the intermediate strata, while the foliar biomass tracked the vertical development of the shrub structure. Dendrochronological analysis revealed that shrub stands are relatively young; most of the dominant stems started their development after 1990. Shrub height was positively associated with both the dominant stem age and its vertical growth rate. Temperature differences among sites were greater during winter (ca 10 °C) than during summer (ca 2 °C), while the sum of freezing degree-days varied from 680 °C to 2125 °C. Shrub height was the most plausible variable explaining snow depth, winter ground level temperature and the sum of freezing degree-days. However, woody biomass in the 30–40 cm strata best explained summer ground level temperature. Our results suggest that the development of a shrub structure will have far-reaching consequences on the abiotic environment of subarctic ecosystems.

  4. Greater effect of increasing shrub height on winter versus summer soil temperature

    NASA Astrophysics Data System (ADS)

    Paradis, Mélissa; Lévesque, Esther; Boudreau, Stéphane

    2016-08-01

    Shrub expansion is increasingly observed in arctic and subarctic environments. The development of shrub structure may significantly impact the abiotic environment at the local scale. Our objective was to reconstruct the development of the vertical structure of Betula glandulosa Michx. and to evaluate its effects on winter and summer soil temperature and on snow depth. Stratified sampling of the shrub revealed that shrub biomass distribution followed a similar pattern in stands of contrasting heights. Woody biomass was maximal in the lower stratum and relatively stable in the intermediate strata, while the foliar biomass tracked the vertical development of the shrub structure. Dendrochronological analysis revealed that shrub stands are relatively young; most of the dominant stems started their development after 1990. Shrub height was positively associated with both the dominant stem age and its vertical growth rate. Temperature differences among sites were greater during winter (ca 10 °C) than during summer (ca 2 °C), while the sum of freezing degree-days varied from 680 °C to 2125 °C. Shrub height was the most plausible variable explaining snow depth, winter ground level temperature and the sum of freezing degree-days. However, woody biomass in the 30-40 cm strata best explained summer ground level temperature. Our results suggest that the development of a shrub structure will have far-reaching consequences on the abiotic environment of subarctic ecosystems.

  5. Summer Camp of Mathematical Modeling in China

    ERIC Educational Resources Information Center

    Tian, Xiaoxi; Xie, Jinxing

    2013-01-01

    The Summer Camp of Mathematical Modeling in China is a recently created experience designed to further Chinese students' academic pursuits in mathematical modeling. Students are given more than three months to research on a mathematical modeling project. Researchers and teams with outstanding projects are invited to the Summer Camp to present…

  6. I Know What You Did Last Summer

    ERIC Educational Resources Information Center

    Opalinski, Gail; Ellers, Sherry; Goodman, Amy

    2004-01-01

    This article describes the revised summer school program developed by the Anchorage (AK) School District for students who received poor grades in their core classes or low scores in the Alaska Benchmark Examinations or California Achievement Tests. More than 500 middle school students from the district spent five weeks during the summer honing…

  7. Six for Summer: Professional Learning Opportunities

    ERIC Educational Resources Information Center

    Curran, Ben

    2014-01-01

    Teaching is and always has been a year-round job. Even when educators are not working during the summer months, they are always planning for the year ahead. This has not changed in the 21st century. In fact, teachers might work harder now than ever. While summer is the perfect time for teachers to relax and recharge their batteries, it also…

  8. Summer Melts Immigrant Students' College Plans

    ERIC Educational Resources Information Center

    Naranjo, Melissa M.; Pang, Valerie Ooka; Alvarado, Jose Luis

    2016-01-01

    Many college-intending students find themselves dealing with the undermatch and summer melt phenomena. Undermatch refers to the situation where academically-successful high-school graduates choose not to go to any college or to go to a local community college not commensurate with their academic achievements. Summer melt describes how students may…

  9. Summer Reading Activities--Way back When.

    ERIC Educational Resources Information Center

    Locke, Jill L.

    1992-01-01

    Describes three public library summer reading programs for children in the 1890s: Hewins' Vacation Reading Club; the Carnegie Library of Pittsburgh's Summer Playground Program; and the Library League of Cleveland. The growth of similar programs and related reports in the library literature of the early twentieth century are discussed, and summer…

  10. 1995 Summer Opportunities for American Indian Students.

    ERIC Educational Resources Information Center

    ORBIS Associates, Washington, DC.

    This document contains information on summer academic programs offered to American Indian and Alaska Native junior high and high school students. Included are mathematics and science summer programs offered to high school students by the American Indian Science and Engineering Society at universities in Oklahoma, New Mexico, Wisconsin, Iowa,…

  11. Lasting Consequences of the Summer Learning Gap

    ERIC Educational Resources Information Center

    Alexander, Karl L.; Entwisle, Doris R.; Olson, Linda Steffel

    2007-01-01

    Prior research has demonstrated that summer learning rooted in family and community influences widens the achievement gap across social lines, while schooling offsets those family and community influences. In this article, we examine the long-term educational consequences of summer learning differences by family socioeconomic level. Using data…

  12. Summer Programming in Rural Communities: Unique Challenges

    ERIC Educational Resources Information Center

    Phillips, Ruthellen; Harper, Stacey; Gamble, Susan

    2007-01-01

    During the past several decades, child poverty rates have been higher in rural than in urban areas, and now 2.5 million children live in deep poverty in rural America. Studies indicate that poor children are most affected by the typical "summer slide." Summer programming has the ability to address the issues of academic loss, nutritional loss, and…

  13. Academic Camps: Why Spend Summer in Class?

    ERIC Educational Resources Information Center

    Rigby, Kristin

    2005-01-01

    Gifted students tend to be drawn to summer gifted programs because of their high level of motivation and their drive to experience an academic challenge (Olszewski-Kubilius & Lee, 2004). Concurrently, academic summer programs yield numerous social-emotional, educational, and family benefits for gifted young people. One of the most beneficial…

  14. Fantasy Quest: Summer Library Program 1997.

    ERIC Educational Resources Information Center

    Thieling, Kaileen R.; Hudspeth, Jean

    This document presents the 1997 Mississippi summer library program for children. Highlights include: planning a summer library program; promotion and tips on writing publicity releases; radio spots (samples); press releases (samples); a sample letter to parents; a general bibliography; selected promotional resources; supply sources; recipes. Also…

  15. Report on the 2008 ISAGA Summer School

    ERIC Educational Resources Information Center

    van de Westelaken, Marleen

    2011-01-01

    This article reports on the 2008 ISAGA Summer School held in New Delhi (Gurgaon), India. This Summer School was hosted by the Institute for Integrated Learning in Management. Participants came from all over the world. This year's theme was "The Art and Science of Simulation and Gaming Design and Facilitation for Business and Management."

  16. Manual for a Summer Reading Program.

    ERIC Educational Resources Information Center

    Medina, Sue O.

    This manual provides suggestions for materials and projects to carry out a summer reading program for children based on a monster theme. The planning process outlined may be used as a "how-to" guide for developing summer reading programs on other themes as well. In addition to general guidelines, the manual provides information on the following…

  17. Districts Add Web Courses for Summer

    ERIC Educational Resources Information Center

    Borja, Rhea R.

    2005-01-01

    More and more school districts, as well as for-profit companies and nonprofit organizations, are offering Internet-based summer classes in core subjects, such as algebra and reading, and electives such as creative writing. In this article, the author discusses the growth of enrollment in online education for summer. The logistical ease of…

  18. Finding the Resources for Summer Learning Programs

    ERIC Educational Resources Information Center

    Sundius, M. Jane

    2007-01-01

    Research on summer learning losses has unambiguous implications for America: all children need learning opportunities in the summer. But how and when policymakers, educators, and youth service providers will fashion appropriate programming are far less clear. At the root of this problem is the need to vastly increase, stabilize, and coordinate…

  19. A New Vision for Summer School

    ERIC Educational Resources Information Center

    Smink, Jeff

    2012-01-01

    Summer school makes an unlikely candidate for a bright spot in education reform during these difficult economic times. It occupies a long-held negative place in U.S. culture, prompting dread in the hearts of many former and current students. Summer school conjures up images of sitting in hot classrooms and receiving remedial instruction while…

  20. Coping – Late Side Effects

    Cancer.gov

    Cancer treatment can cause late side effects that may not show up for months or years after treatment. These late effects may include heart and lung problems, bone loss, eye and hearing changes, lymphedema, and other problems

  1. The influence of winter cloud on summer sea ice in the Arctic, 1983-2013

    NASA Astrophysics Data System (ADS)

    Letterly, Aaron; Key, Jeffrey; Liu, Yinghui

    2016-03-01

    Arctic sea ice extent has declined dramatically over the last two decades, with the fastest decrease and greatest variability in the Beaufort, Chukchi, and East Siberian Seas. Thinner ice in these areas is more susceptible to changes in cloud cover, heat and moisture advection, and surface winds. Using two climate reanalyses and satellite data, it is shown that increased wintertime surface cloud forcing contributed to the 2007 summer sea ice minimum. An analysis over the period 1983-2013 reveals that reanalysis cloud forcing anomalies in the East Siberian and Kara Seas precondition the ice pack and, as a result, explain 25% of the variance in late summer sea ice concentration. This finding was supported by Moderate Resolution Imaging Spectroradiometer cloud cover anomalies, which explain up to 45% of the variance in sea ice concentration. Results suggest that winter cloud forcing anomalies in this area have predictive capabilities for summer sea ice anomalies across much of the central and Eurasian Arctic.

  2. Strong release of methane on Mars in northern summer 2003.

    PubMed

    Mumma, Michael J; Villanueva, Geronimo L; Novak, Robert E; Hewagama, Tilak; Bonev, Boncho P; Disanti, Michael A; Mandell, Avi M; Smith, Michael D

    2009-02-20

    Living systems produce more than 90% of Earth's atmospheric methane; the balance is of geochemical origin. On Mars, methane could be a signature of either origin. Using high-dispersion infrared spectrometers at three ground-based telescopes, we measured methane and water vapor simultaneously on Mars over several longitude intervals in northern early and late summer in 2003 and near the vernal equinox in 2006. When present, methane occurred in extended plumes, and the maxima of latitudinal profiles imply that the methane was released from discrete regions. In northern midsummer, the principal plume contained approximately 19,000 metric tons of methane, and the estimated source strength (>/=0.6 kilogram per second) was comparable to that of the massive hydrocarbon seep at Coal Oil Point in Santa Barbara, California. PMID:19150811

  3. Characterizing the onset and demise of the Indian summer monsoon

    NASA Astrophysics Data System (ADS)

    Noska, Ryne; Misra, Vasubandhu

    2016-05-01

    An objective index of the onset and demise of the Indian summer monsoon (ISM) is introduced. This index has the advantage of simplicity by using only one variable, which is the spatially averaged all-India rainfall, a reliably observed quantity for more than a century. The proposed onset index is shown to be insensitive to all historic false onsets. By definition, now the seasonal mean rainfall anomalies become a function of variations in onset and demise dates, rendering their monitoring to be very meaningful. This new index provides a comprehensive representation of the seasonal evolution of the ISM by capturing the corresponding changes in large-scale dynamic and thermodynamic variables. We also show that the interannual variability of the onset date of the ISM is associated with El Niño-Southern Oscillation (ENSO) with early (late) onsets preceded by cold (warm) ENSO.

  4. The soil electric potential signature of summer drought

    NASA Astrophysics Data System (ADS)

    Outcalt, S. I.; Hinkel, K. M.

    1990-03-01

    During the period from late April to early August, a timeseries of soil electric potential measurements in the upper 15 cm of mineral soil were collected daily at the University of Michigan Botanical Gardens using an automatic data collection system. These data, after conversion to a surrogate measure of electrolyte concentration, provide a unique record of the 1988 summer drought in a continental location. The effects of rainfall-dewfall electrolyte dilution, evaporation-induced electrolyte concentration and upward-downward soil water advection are well-illustrated in the data. These observations demonstrate that soil electric potential is an easily measured variable of high information content, especially when collected with other system-linked environmental data.

  5. Late embryogenesis abundant proteins

    PubMed Central

    Olvera-Carrillo, Yadira; Reyes, José Luis

    2011-01-01

    Late Embryogenesis Abundant (LEA) proteins accumulate at the onset of seed desiccation and in response to water deficit in vegetative plant tissues. The typical LEA proteins are highly hydrophilic and intrinsically unstructured. They have been classified in different families, each one showing distinctive conserved motifs. In this manuscript we present and discuss some of the recent findings regarding their role in plant adaptation to water deficit, as well as those concerning to their possible function, and how it can be related to their intrinsic structural flexibility. PMID:21447997

  6. Relations between winter climatic variables and April streamflows in New England and implications for summer streamflows

    USGS Publications Warehouse

    Hodgkins, Glenn A.; Dudley, Robert W.; Schalk, Luther F.

    2012-01-01

    A period of much below normal streamflow in southern New England during April 2012 raised concerns that a long-term period of drought could evolve through late spring and summer, leading to potential water availability issues. To understand better the relations between winter climatic variables and April streamflows, April streamflows from 31 streamflow gages in New England that drain relatively natural watersheds were tested for year-to-year correlation with winter precipitation and air temperature from nearby meteorological sites. Higher winter (December through March) precipitation is associated with higher April streamflows at many gages in northern and central New England. This implies that snowpack accumulation is an important mechanism for winter water storage and subsequently important for spring streamflows in this area. Higher March air temperatures are associated with lower April streamflows at many gages in central and southern New England, likely because the majority of snowmelt runoff occurs before April in warm years. A warm March 2012 contributed to early snowmelt runoff in New England and to much below normal April streamflows in southern New England. However, no strong relation was found between historical April streamflows and late-spring or summer streamflows in New England. The lack of a strong relation implies that summer precipitation, rather than spring conditions, controls summer streamflows.

  7. Summer low flows in New England during the 20th Century

    USGS Publications Warehouse

    Hodgkins, G.A.; Dudley, R.W.; Huntington, T.G.

    2005-01-01

    High springtime river flows came earlier by one to two weeks in large parts of northern New England during the 20th Century. In this study it was hypothesized that late spring/early summer recessional flows and late summer/early fall low flows could also be occurring earlier. This could result in a longer period of low flow recession and a decrease in the magnitude of low flows. To test this hypothesis, variations over time in the magnitude and timing of low flows were analyzed. To help understand the relation between low flows and climatic variables in New England, low flows were correlated with air temperatures and precipitation. Analysis of data from 23 rural, unregulated rivers across New England indicated little evidence of consistent changes in the timing or magnitude of late summer/early fall low flows during the 20th Century. The interannual variability in the timing and magnitude of the low flows in northern New England was explained much more by the interannual variability in precipitation than by the interannual variability of air temperatures. The highest correlation between the magnitude of the low flows and air temperatures was with May through November temperatures (r = -0.37, p = 0.0017), while the highest correlation with precipitation was with July through August precipitation (r = 0.67, p < 0.0001). (JAWRA) (Copyright ?? 2005).

  8. Predictability of Euro-Russian blocking in summer of 2010

    NASA Astrophysics Data System (ADS)

    Matsueda, Mio

    2011-03-01

    Eastern Europe and Western Russia experienced a strong heat wave during the summer of 2010. Maximum temperatures exceeded 40°C in early August, resulting in over 15,000 deaths and many wildfires, inflicting large economic losses on Russia. The heat wave resulted from strong atmospheric blocking that persisted over the Euro-Russian region from late June to early August. This study investigates the predictabilities of extreme Euro-Russian blocking and of the blocking-induced extreme surface temperatures in the summer of 2010, using medium-range ensemble forecasts. The results show that the blocking in June-August (JJA) of 2010 was easily predictable, even for a lead time of +216 hr; however, the blocking that occurred from 30th July to 9th August showed a lower predictability in forecasts over +144 hr compared with other blocking occurrences in JJA of 2010. This low predictability resulted in the failure to predict the extreme temperatures associated with the mature blocking in early August. Most of the forecasts predicted a decay of the blocking earlier than that observed.

  9. Impact of vertical and horizontal advection on nutrient distribution in the southeast Pacific

    NASA Astrophysics Data System (ADS)

    Barceló-Llull, Bàrbara; Mason, Evan; Capet, Arthur; Pascual, Ananda

    2016-08-01

    An innovative approach is used to analyze the impact of vertical velocities associated with quasi-geostrophic (QG) dynamics on the redistribution and uptake of nitrate in the southeast Pacific (SEP). A total of 12 years of vertical and horizontal currents are derived from an observation-based estimate of the ocean state. Horizontal velocities are obtained through the application of thermal wind balance to weekly temperature and salinity fields. Vertical velocities are estimated by integration of the QG omega equation. Seasonal variability of the synthetic vertical velocity and kinetic energy associated with the horizontal currents is coincident, with peaks in austral summer (November-December) in accord with published observations. The impact of vertical velocity on SEP nitrate uptake rates is assessed by using two Lagrangian particle tracking experiments that differ according to vertical forcing (ω = ωQG vs. ω = 0). From identical initial distributions of nitrate-tagged particles, the Lagrangian results show that vertical motions induce local increases in nitrate uptake reaching up to 30 %. Such increases occur in low uptake regions with high mesoscale activity. Despite being weaker than horizontal currents by a factor of up to 10-4, vertical velocity associated with mesoscale activity is demonstrated to make an important contribution to nitrate uptake, hence productivity, in low uptake regions.

  10. ASCOS - the "Arctic Summer Cloud-Ocean Study"

    NASA Astrophysics Data System (ADS)

    Tjernström, M.; Leck, C.

    2008-12-01

    Understanding the effects of clouds on climate still constitute one of the largest challenges and this is perhaps more true in the Arctic than elsewhere. Clouds have the single largest impact on the surface energy budget and thus control a significant fraction of the melting and freezing of sea ice. At the same time, we know less of about cloud formation in the Arctic than elsewhere; this fact is also reflected in modeling results for the Arctic. ASCOS is an interdisciplinary experimental program, with its field phase in the central Arctic onboard the Swedish icebreaker Oden during August and early September 2008; the timing was chosen to bee during the late summer melt and into the intial surface freeze. Within ASCOS seventeen research groups from eleven countries, with fourteen nationalities, came together to attempt understanding the formation of Arctic summer clouds, their impact on summer melt and initiation of the surface freeze up. ASCOS is among the broadest projects in IPY. ASCOS brings marine biology and chemistry, physical oceanography, meteorology, atmospheric gas phase and particulate chemistry and physics into the same experiment to observe aerosols, cloud condensation and ice nuclei formation, cloud formation, interaction between clouds and surface energy balance and with larger scale weather. Observations were performed on board the ice breaker and on the ice during a three week ice drift, by in situ or remote sensing instruments. ASCOS is an IPY program under the umbrella of AICI-IPY, and is affiliated with several other IPY project, and is also a part of DAMOCLESA. The presentation will provide a brief overview of ASCOS and show examples of the benefits of the interdisciplinary and international approach of ASCOS.

  11. Summer Dormancy in Perennial Temperate Grasses

    PubMed Central

    VOLAIRE, FLORENCE; NORTON, MARK

    2006-01-01

    • Background and Aims Dormancy has been extensively studied in plants which experience severe winter conditions but much less so in perennial herbaceous plants that must survive summer drought. This paper reviews the current knowledge on summer dormancy in both native and cultivated perennial temperate grasses originating from the Mediterranean Basin, and presents a unified terminology to describe this trait. • Scope Under severe drought, it is difficult to separate the responses by which plants avoid and tolerate dehydration from those associated with the expression of summer dormancy. Consequently, this type of endogenous (endo-) dormancy can be tested only in plants that are not subjected to moisture deficit. Summer dormancy can be defined by four criteria, one of which is considered optional: (1) reduction or cessation of leaf production and expansion; (2) senescence of mature foliage; (3) dehydration of surviving organs; and (4, optional) formation of resting organs. The proposed terminology recognizes two levels of summer dormancy: (a) complete dormancy, when cessation of growth is associated with full senescence of foliage and induced dehydration of leaf bases; and (b) incomplete dormancy, when leaf growth is partially inhibited and is associated with moderate levels of foliage senescence. Summer dormancy is expressed under increasing photoperiod and temperature. It is under hormonal control and usually associated with flowering and a reduction in metabolic activity in meristematic tissues. Dehydration tolerance and dormancy are independent phenomena and differ from the adaptations of resurrection plants. • Conclusions Summer dormancy has been correlated with superior survival after severe and repeated summer drought in a large range of perennial grasses. In the face of increasing aridity, this trait could be used in the development of cultivars that are able to meet agronomic and environmental goals. It is therefore important to have a better

  12. Avoidance of late abortion.

    PubMed

    1979-11-24

    Induced abortion is now a common procedure in the United States and Britain. Methods for performing induced abortion are reviewed. Menstrual regulation, aspiration with a hand-held syringe and a flexible cannula within 6 weeks of the last period, is not often practiced in Britain. Several developing countries are using this simple technique to advantage. Vacuum aspiration in the 1st 12 weeks of pregnancy is the main method being used everywhere for 1st trimester procedures. Mortality rates with this method are low and, in well-organized clinics with experienced personnel, the rates can be reduced even further. It is agreed that 2nd trimester procedures are more complex, both physically and emotionally. In the last several years, dilatation and evacuation (D&E) has increased in popularity for 2nd trimester procedures. Dilation of the cervix is generally accomplished with laminaria, evacuation of the uterus with forceps, and then suction curettage applied. This procedure has replaced intraamniotic infusion, hysterotomy, and hysterectomy as the most commonly - practiced method, despite its need for special surgical skills and good clinical backup. Follow-up of abortions is difficult. Different long-term effects have been noted with different abortion procedures. Early abortion seems to have only a modest effect, if that. Whether late abortion has long-lasting effects remains open to question. Late abortion should be avoided.

  13. Final Report - Summer Visit 2010

    SciTech Connect

    Bank, R

    2011-09-12

    During my visit to LLNL during the summer of 2010, I worked on algebraic multilevel solvers for large sparse systems of linear equations arising from discretizations of partial differential equations. The particular solver of interest is based on ILU decomposition. The setup phase for this AMG solve is just the single ILU decomposition, and its corresponding error matrix. Because the ILU uses a minimum degree or similar sparse matrix ordering, most of the fill-in, and hence most of the error, is concentrated in the lower right corner of the factored matrix. All of the major multigrid components - the smoother, the coarse level correction matrices, and the fine-to-coarse and coarse-to-fine rectangular transfer matrices, are defined in terms of various blocks of the ILU factorization. Although such a strategy is not likely to be optimal in terms of convergence properties, it has a relatively low setup cost, and therefore is useful in situations where setup costs for more traditional AMG approaches cannot be amortized over the solution of many linear systems using the same matrix. Such a situation arises in adaptive methods, where often just one linear system is solved at each step of an adaptive feedback loop, or in solving nonlinear equations by approximate Newton methods, where the approximate Jacobian might change substantially from iteration to iteration. In general terms, coarse levels are defined in terms of successively smaller lower right blocks of the matrix, typically decreasing geometrically in order. The most difficult issue was the coarse grid correction matrix. The preconditioner/smoother for a given level is just the corresponding lower right blocks of the ILU factorization. The coarse level matrix itself is just the Schur complement; this matrix is not known exactly using just the ILU decomposition in the setup phase. Thus we approximate this matrix using various combinations of the preconditioning matrix and the error matrix. During my visit, several

  14. The Summer Robotic Autonomy Course

    NASA Technical Reports Server (NTRS)

    Nourbakhsh, Illah R.

    2002-01-01

    We offered a first Robotic Autonomy course this summer, located at NASA/Ames' new NASA Research Park, for approximately 30 high school students. In this 7-week course, students worked in ten teams to build then program advanced autonomous robots capable of visual processing and high-speed wireless communication. The course made use of challenge-based curricula, culminating each week with a Wednesday Challenge Day and a Friday Exhibition and Contest Day. Robotic Autonomy provided a comprehensive grounding in elementary robotics, including basic electronics, electronics evaluation, microprocessor programming, real-time control, and robot mechanics and kinematics. Our course then continued the educational process by introducing higher-level perception, action and autonomy topics, including teleoperation, visual servoing, intelligent scheduling and planning and cooperative problem-solving. We were able to deliver such a comprehensive, high-level education in robotic autonomy for two reasons. First, the content resulted from close collaboration between the CMU Robotics Institute and researchers in the Information Sciences and Technology Directorate and various education program/project managers at NASA/Ames. This collaboration produced not only educational content, but will also be focal to the conduct of formative and summative evaluations of the course for further refinement. Second, CMU rapid prototyping skills as well as the PI's low-overhead perception and locomotion research projects enabled design and delivery of affordable robot kits with unprecedented sensory- locomotory capability. Each Trikebot robot was capable of both indoor locomotion and high-speed outdoor motion and was equipped with a high-speed vision system coupled to a low-cost pan/tilt head. As planned, follow the completion of Robotic Autonomy, each student took home an autonomous, competent robot. This robot is the student's to keep, as she explores robotics with an extremely capable tool in the

  15. The boreal summer intraseasonal oscillation simulated by four Chinese AGCMs participating in the CMIP5 project

    NASA Astrophysics Data System (ADS)

    Zhao, Chongbo; Zhou, Tianjun; Song, Lianchun; Ren, Hongli

    2014-09-01

    The performances of four Chinese AGCMs participating in the Coupled Model Intercomparison Project Phase 5 (CMIP5) in the simulation of the boreal summer intraseasonal oscillation (BSISO) are assessed. The authors focus on the major characteristics of BSISO: the intensity, significant period, and propagation. The results show that the four AGCMs can reproduce boreal summer intraseasonal signals of precipitation; however their limitations are also evident. Compared with the Climate Prediction Center Merged Analysis of Precipitation (CMAP) data, the models underestimate the strength of the intraseasonal oscillation (ISO) over the eastern equatorial Indian Ocean (IO) during the boreal summer (May to October), but overestimate the intraseasonal variability over the western Pacific (WP). In the model results, the westward propagation dominates, whereas the eastward propagation dominates in the CMAP data. The northward propagation in these models is tilted southwest-northeast, which is also different from the CMAP result. Thus, there is not a northeast-southwest tilted rain belt revolution off the equator during the BSISO's eastward journey in the models. The biases of the BSISO are consistent with the summer mean state, especially the vertical shear. Analysis also shows that there is a positive feedback between the intraseasonal precipitation and the summer mean precipitation. The positive feedback processes may amplify the models' biases in the BSISO simulation.

  16. Vertical motion simulator familiarization guide

    NASA Technical Reports Server (NTRS)

    Danek, George L.

    1993-01-01

    The Vertical Motion Simulator Familiarization Guide provides a synoptic description of the Vertical Motion Simulator (VMS) and descriptions of the various simulation components and systems. The intended audience is the community of scientists and engineers who employ the VMS for research and development. The concept of a research simulator system is introduced and the building block nature of the VMS is emphasized. Individual sections describe all the hardware elements in terms of general properties and capabilities. Also included are an example of a typical VMS simulation which graphically illustrates the composition of the system and shows the signal flow among the elements and a glossary of specialized terms, abbreviations, and acronyms.

  17. Measurements of vertical bar Vcb vertical bar and vertical bar Vub vertical bar at BaBar

    SciTech Connect

    Rotondo, M.

    2005-10-12

    We report results from the BABAR Collaboration on the semileptonic B decays, highlighting the measurements of the magnitude of the Cabibbo-Kobayashi-Maskawa matrix elements Vub and Vcb. We describe the techniques used to obtain the matrix element |Vcb| using the measurement of the inclusive B {yields} Xclv process and a large sample of exclusive B {yields} D*lv decays. The vertical bar Vub vertical bar matrix elements has been measured studying different kinematic variables of the B {yields} Xulv process, and also with the exclusive reconstruction of B {yields} {pi}({rho})lv decays.

  18. Late Quaternary stratigraphy, sedimentology, and geochemistry of an underfilled lake basin in the Puna (north-west Argentina)

    USGS Publications Warehouse

    McGlue, Michael M.; Cohen, Andrew S.; Ellis, Geoffrey S.; Kowler, Andrew L.

    2013-01-01

    Depositional models of ancient lakes in thin-skinned retroarc foreland basins rarely benefit from appropriate Quaternary analogues. To address this, we present new stratigraphic, sedimentological and geochemical analyses of four radiocarbon-dated sediment cores from the Pozuelos Basin (PB; northwest Argentina) that capture the evolution of this low-accommodation Puna basin over the past ca. 43 cal kyr. Strata from the PB are interpreted as accumulations of a highly variable, underfilled lake system represented by lake-plain/littoral, profundal, palustrine, saline lake and playa facies associations. The vertical stacking of facies is asymmetric, with transgressive and thin organic-rich highstand deposits underlying thicker, organic-poor regressive deposits. The major controls on depositional architecture and basin palaeogeography are tectonics and climate. Accommodation space was derived from piggyback basin-forming flexural subsidence and Miocene-Quaternary normal faulting associated with incorporation of the basin into the Andean hinterland. Sediment and water supply was modulated by variability in the South American summer monsoon, and perennial lake deposits correlate in time with several well-known late Pleistocene wet periods on the Altiplano/Puna plateau. Our results shed new light on lake expansion–contraction dynamics in the PB in particular and provide a deeper understanding of Puna basin lakes in general.

  19. Rainfall regime changes and trends in Botswana Kalahari Transect's late summer precipitation

    NASA Astrophysics Data System (ADS)

    Mphale, K. M.; Dash, S. K.; Adedoyin, A.; Panda, S. K.

    2014-04-01

    Sixty-year-long January-March (JFM) rainfall data from four (4) stations along the Kalahari Transect were analyzed for long-term trends and abrupt changes in rainfall regimes. On average, JFM rainfall accounts for more than 50 % of annual rainfall in the region. Mann-Kendall trend test has shown an insignificant heterogeneous trend in the seasonal rainfall of -1.097, 0.029, -0.407, and -1.327 mm/year for Maun, Ghanzi, Tsabong, and Tshane, respectively. An abrupt change in rainfall regimes in these areas was investigated and was found to occur in the year 1982 for all stations. The change is related to large-scale atmospheric circulations. Analysis of large-scale atmospheric circulations before 1982 over the region has shown the formation of a tropical low pressure convective system over the Kalahari Transect. The tropical system shifted eastward after 1982 to be centered over southeastern southern Africa with a significant reduction in rainfall over the Kalahari. A direct impact of this is the livestock-induced overgrazing which has lead to excessive removal of palatable herbaceous species thereby giving woody species, such as Accacia mellifera and Grewia flava, a competitive edge for dominance in the ecosystems. Seed production of A. mellifera depends on rainfall; therefore, abrupt changes in rainfall regimes impact livelihood and eco-tourism industry. The correlation studies between rainfall anomalies and NINO3.4 indices show a reduction in the influence of El-Niño Southern Oscillation on the Kalahari Transect rainfall after 1982.

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

    NASA Astrophysics Data System (ADS)

    Pelto, M.

    2011-05-01

    On Taku Glacier, Alaska a combination of field observations of snow water equivalent (SWE) from snowpits and probing in the vicinity of the transient snowline (TSL) are used to quantify the mass balance gradient. The balance gradient is determined from the difference in elevation and SWE from the TSL to snowpits at 1000 m from 1998-2010 and ranges from 2.6-3.8 mm m-1. Probing transects from 950 m-1100 m directly measure SWE and yield a slightly higher balance gradient of 3.3-3.8 mm m-1. TSL is identified in MODIS and Landsat 4 and 7 Thematic Mapper imagery for 31 dates during the 2004-2010 period on Taku Glacier to assess the consistency of its rate of rise and usefulness in assessing mass balance. In 2010, the TSL rose from 750 m on 28 July, 800 m on 5 August, 875 m on 14 August, 925 m on 30 August, and to 975 m on 20 September. The mean observed probing balance gradient was 3.3 mm m-1 and TSL rise was 3.7 m day-1, yielding an ablation rate of 12.2 mm day-1 on Taku Glacier from mid-July to mid-September. A comparison of the TSL rise in the region from 750-1100 m on Taku Glacier during eleven different periods of more than 14 days during the ablation season with repeat imagery indicates a mean TSL rise of 3.7 m day-1 on Taku Glacier, the rate of rise is relatively consistent ranging from 3.0 to 4.8 m day-1. This is useful for ascertaining the final ELA if imagery or observations are not available within a week or two of the end of the ablation season. From mid-July-mid-September the mean ablation from 750-1100 m determined from the TSL rise and the observed balance gradient varied from 11 to 18 mm day-1 on Taku Glacier during the 2004-2010 period.

  1. Southern European rainfall reshapes the early-summer circumglobal teleconnection after the late 1970s

    NASA Astrophysics Data System (ADS)

    Liu, Xiangwen; Wu, Tongwen; Yang, Song; Li, Tim; Jie, Weihua; Zhang, Li; Wang, Zaizhi; Liang, Xiaoyun; Li, Qiaoping; Cheng, Yanjie; Ren, Hongli; Fang, Yongjie; Nie, Suping

    2016-08-01

    By conducting several sets of hindcast experiments using the Beijing Climate Center Climate System Model, which participates in the Sub-seasonal to Seasonal (S2S) Prediction Project, we systematically evaluate the model's capability in forecasting MJO and its main deficiencies. In the original S2S hindcast set, MJO forecast skill is about 16 days. Such a skill shows significant seasonal-to-interannual variations. It is found that the model-dependent MJO forecast skill is more correlated with the Indian Ocean Dipole (IOD) than with the El Niño-Southern Oscillation. The highest skill is achieved in autumn when the IOD attains its maturity. Extended skill is found when the IOD is in its positive phase. MJO forecast skill's close association with the IOD is partially due to the quickly strengthening relationship between MJO amplitude and IOD intensity as lead time increases to about 15 days, beyond which a rapid weakening of the relationship is shown. This relationship transition may cause the forecast skill to decrease quickly with lead time, and is related to the unrealistic amplitude and phase evolutions of predicted MJO over or near the equatorial Indian Ocean during anomalous IOD phases, suggesting a possible influence of exaggerated IOD variability in the model. The results imply that the upper limit of intraseasonal predictability is modulated by large-scale external forcing background state in the tropical Indian Ocean. Two additional sets of hindcast experiments with improved atmosphere and ocean initial conditions (referred to as S2S_IEXP1 and S2S_IEXP2, respectively) are carried out, and the results show that the overall MJO forecast skill is increased to 21-22 days. It is found that the optimization of initial sea surface temperature condition largely accounts for the increase of the overall MJO forecast skill, even though the improved initial atmosphere conditions also play a role. For the DYNAMO/CINDY field campaign period, the forecast skill increases to 27 days in S2S_IEXP2. Nevertheless, even with improved initialization, it is still difficult for the model to predict MJO propagation across the western hemisphere-western Indian Ocean area and across the eastern Indian Ocean-Maritime Continent area. Especially, MJO prediction is apparently limited by various interrelated deficiencies (e.g., overestimated IOD, shorter-than-observed MJO life cycle, Maritime Continent prediction barrier), due possibly to the model bias in the background moisture field over the eastern Indian Ocean and Maritime Continent. Thus, more efforts are needed to correct the deficiency in model physics in this region, in order to overcome the well-known Maritime Continent predictability barrier.

  2. Internal wave damping in the East China in late summer 2014

    NASA Astrophysics Data System (ADS)

    Kuh Kang, Sok; Lee, Jae Hak; Park, Jae-Hun; Kim, Eun Jin; Hong, Chang Su

    2016-04-01

    A field measurement was carried out to observe generation, propagation and damping of the internal waves on the continental shelf around 31N in the East China Sea during September 16-27, 2014. Two trawl-resistant bottom mount ADCPs (M1, M2) were deployed along 126.5oE with 10 km apart. Over the 10 km distance the dominant frequency internal wave group with periods around 500 s is estimated to dissipate its energy by about 30%. The damping process appears to be partly related with the higher-mode evolution at the downward station M1, compared with the 1st-mode dominancy at the upstream station (M2). Our observations suggest that the damping processes of internal waves on the continental shelf of the East China Sea occur by rather complicated manners than by the simple process due to frictional decaying. This work was partially supported by KIOST projects (PE99396)and this research has been performed as collaborative research project of project No (Development of HPC-based management system againstnational scale disaster) and supported by the KOREA INSTITUTE of SCIENCE and TECHNOLOGY INFORMATION (KISTI).

  3. Vertical tail buffeting of fighter aircraft

    NASA Astrophysics Data System (ADS)

    Lee, B. H. K.

    2000-04-01

    Vertical tail buffeting at high angles of attack is a phenomenon associated with the impact of vortical flows generated by the aircraft on the fins. This poses a serious problem for both single- and twin-tail fighter aircraft from the point of view of combat maneuverability and structural integrity. The research activities to understand the flow physics with an aim to alleviate buffet loads were quite intense during the period from the late 1970s to the early 1990s. Most of the investigations were carried out on the F/A-18 mainly because of two international programs involving countries that operate the F/A-18 in their air force. This review begins with a description of the water tunnel experiments showing some flow visualization results of the leading-edge extension (LEX) burst vortical flows. Wind tunnel studies on a 1/9 scale F/A-18 model in Australia, a 1/6.65 scale model in the United Kingdom, a 6% scale model in Canada, 12%, 16% and full-scale models in the United States are summarized. Scale effects can be deduced from the various sub- and full-scale models tested. Flight test results conducted on the High Alpha Research Vehicle in the United States and on an instrumented CF-18 test aircraft in Canada are presented. The accuracy of analytical methods utilizing wind tunnel data to predict buffet loads at flight conditions is discussed. The use of CFD to compute vertical fin buffeting is challenging and requires a large amount of computing power. A brief exposure to the methodology is given and results from the only available computational case study carried out by NASA Ames are compared with wind tunnel and flight test data. A short introduction to statistical non-stationary effects is given. Hysteresis effect of the LEX vortex burst on the buffet loads is discussed, and a statistical non-stationary buffet prediction method is outlined. This review provides a useful reference to the results collected from the High Alpha Technology Program, The Technical

  4. Summer diapause induced by high temperatures in the oriental tobacco budworm: ecological adaptation to hot summers.

    PubMed

    Liu, Zhudong; Xin, Yucui; Zhang, Yanan; Fan, Jianting; Sun, Jianghua

    2016-01-01

    Summer diapause in Helicoverpa assulta (Hübner), which prolongs the pupal stage, particularly in males, is induced by high temperatures. In the laboratory, 3(rd)-, 4(th)-, 6(th)-instar and prepupal larvae were exposed to high temperatures - 33 and 35 °C with a photoperiod of LD16:8 - until pupation to induce summer diapause. The results showed that the incidence of summer diapause was influenced by temperature, stage exposed, and sex. The higher the temperature, the more often summer diapause was attained. Sixth-instar and prepupal larvae were the sensitive stages for summer diapause induction. H. assulta summer-diapausing pupae needed diapause development to resume development when temperatures became favorable. Furthermore, both body mass and energy storage capacity (lipid and glycogen) were significantly affected by diapause rather than sex, and were significantly higher in summer-diapausing pupae than in non-diapausing pupae. In addition, the body mass loss and respiration rate showed that the rate of metabolism in the summer-diapausing pupae was consistently lower than in non-diapausing pupae, which were significantly affected by diapause and pupal age. We conclude that summer diapause in H. assulta is a true diapause, and H. assulta has evolved mechanisms to accumulate energy storage and to lower its metabolism to adapt to hot summers. PMID:27271223

  5. Summer diapause induced by high temperatures in the oriental tobacco budworm: ecological adaptation to hot summers

    PubMed Central

    Liu, Zhudong; Xin, Yucui; Zhang, Yanan; Fan, Jianting; Sun, Jianghua

    2016-01-01

    Summer diapause in Helicoverpa assulta (Hübner), which prolongs the pupal stage, particularly in males, is induced by high temperatures. In the laboratory, 3rd-, 4th-, 6th-instar and prepupal larvae were exposed to high temperatures – 33 and 35 °C with a photoperiod of LD16:8 – until pupation to induce summer diapause. The results showed that the incidence of summer diapause was influenced by temperature, stage exposed, and sex. The higher the temperature, the more often summer diapause was attained. Sixth-instar and prepupal larvae were the sensitive stages for summer diapause induction. H. assulta summer-diapausing pupae needed diapause development to resume development when temperatures became favorable. Furthermore, both body mass and energy storage capacity (lipid and glycogen) were significantly affected by diapause rather than sex, and were significantly higher in summer-diapausing pupae than in non-diapausing pupae. In addition, the body mass loss and respiration rate showed that the rate of metabolism in the summer-diapausing pupae was consistently lower than in non-diapausing pupae, which were significantly affected by diapause and pupal age. We conclude that summer diapause in H. assulta is a true diapause, and H. assulta has evolved mechanisms to accumulate energy storage and to lower its metabolism to adapt to hot summers. PMID:27271223

  6. Late-Holocene rodent middens from Rio Limay, Neuquen Province, Argentina

    USGS Publications Warehouse

    Markgraf, Vera; Betancourt, J.; Rylander, K.A.

    1997-01-01

    Pollen analysis of late-Holocene amberat deposits from two caves near the forest-steppe ecotone in northern Patagonia documents a major shift from Austrocedrus-Nothofagus forest to steppe shrub assemblages some time after 1800 and before 1300 BP. The probable explanation of the reduction of tree taxa calls for either drier summers or intensified land use or a combination of both.

  7. Bottom up effects on bacterioplankton growth and composition during summer-autumn transition in the open NW Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    van Wambeke, F.; Ghiglione, J.-F.; Nedoma, J.; Mével, G.; Raimbault, P.

    2009-04-01

    We examined the vertical and temporal dynamics of nutrients, ectoenzymatic activities under late summer-fall transition period (September-October 2004) in NW Mediterranean Sea in relation to temporal change in factors limiting bacterial production. The depth of the mixed layer (12.8±5.3 m) was extremely stable until the onset of the destratification period after 11 October, creating a zone where diffusion of nutrient from the much deeper phosphacline (69±12 m) and nitracline (50±8 m) was probably strongly limited. However after 1st October, a shallowing of nutriclines occured, particularly marked for nitracline. Hence, the nitrate to phosphate ratio within the mixed layer, although submitted to a high short term variability, shifted the last week of the cruise from 1.1±1.2 to 4.6±3.8, and nitrate increased by a factor 2 (0.092±0.049 μM). A corresponding switch from more than one limitation (PN) to P-only limitation of bacterial production was observed during the month as detected by enrichment bioassays. Differences in the identity of the limiting nutrient in surface (5 m: N and P at the beginning, strictly P at the end of the study) versus 80 m (labile carbon) influence greatly bacterial community structure shift between these two layers. The two communities (5 and 80 m) reacted rapidly (24 h) to changes in nutrient concentrations by drastic modification of total and active population assemblages resulting in changes in activity. For bacterial production values less than 10 ng C l-1 h-1 (associated to deeper layers), aminopeptidase and lipase exhibited higher activity relative to production whereas phosphatase varied in the same proportions than BP on the range of activities tested. Our results illustrate the effect of bottom-up control on bacterial community structure and activities in the epipelagic NW Mediterranean Sea.

  8. Different characteristics of the quasi-biweekly oscillation over the South China Sea in two boreal summer stages

    NASA Astrophysics Data System (ADS)

    Wang, Xu; Chen, Guanghua; Huang, Ronghui

    2016-10-01

    This study investigates different evolutions and spatial structures of the quasi-biweekly oscillation (QBWO) over the South China Sea (SCS) during the early (May-June, MJ) and late (August-September, AS) summers of 1991-2010. During the MJ stage, a local QBWO in convection is dominant over the SCS, which is strengthened by the southwestward extension of QBWO anomaly from the east of Japan. In contrast, the QBWO during the AS stage originates from the east of the Philippines and propagates northwestward and then westward until attaining maturation over the SCS, followed by a gradual decay while moving westward. Regarding the circulations, the QBWO during the MJ stage is accompanied by a wave train of lower-level circulation anomalies extending from the SCS to the North Pacific. However, it is found that a wave train exists from the equator to the north of the SCS during the AS stage. In the vertical structures, the QBWO exhibits a northeast tilted relative vorticity with height during the MJ stage, while a vorticity anomaly extending from the surface up to near 300 hPa, but with an opposite above during the AS stage. In general, the QBWO active phases during both stages are characterized by the low-level convergence and cold anomaly and upper-level divergence and warm anomaly, with a strong upward motion. However, the cold anomaly at the low level is prominent during the MJ stage in contrast to that during the AS stage. And the warm anomaly at the upper level reveals a distinct enhancement from the MJ to AS stage.

  9. Is Summer Reading Itself an Old Adage?

    ERIC Educational Resources Information Center

    Lockerbie, D. Bruce

    1970-01-01

    Maintains that traditional summer reading assignments discourage students' pleasurable responses to reading; based on a paper presented at annual convention of National Council of Teachers of English (59th, Washington, D.C., November 29, 1969). (RD)

  10. NASA Kicks Off Summer of Innovation

    NASA Video Gallery

    NASA Administrator Charlie Bolden, astronaut Leland Melvin and others joined students at NASA's Jet Propulsion Laboratory in California to kick off the Summer of Innovation, an initiative to engage...

  11. Report to DHS on Summer Internship 2006

    SciTech Connect

    Beckwith, R H

    2006-07-26

    This summer I worked at Lawrence Livermore National Laboratory in a bioforensics collection and extraction research group under David Camp. The group is involved with researching efficiencies of various methods for collecting bioforensic evidence from crime scenes. The different methods under examination are a wipe, swab, HVAC filter and a vacuum. The vacuum is something that has particularly gone uncharacterized. My time was spent mostly on modeling and calculations work, but at the end of the summer I completed my internship with a few experiments to supplement my calculations. I had two major projects this summer. My first major project this summer involved fluid mechanics modeling of collection and extraction situations. This work examines different fluid dynamic models for the case of a micron spore attached to a fiber. The second project I was involved with was a statistical analysis of the different sampling techniques.

  12. Romping through Summer in a Wheelchair.

    ERIC Educational Resources Information Center

    Nolan, Karen

    1981-01-01

    Children with physical handicaps can participate in many of the same summer camp activities as non-disabled persons. Described are the programs at Camp Merry Heart, operated by New Jersey's Easter Seal Society. (WB)

  13. Quartz Mountain/Oklahoma Summer Arts Institute.

    ERIC Educational Resources Information Center

    Frates, Mary Y.; Madeja, Stanley S.

    1982-01-01

    Describes the Quartz Mountain Oklahoma Summer Arts Institute program. It is designed to nurture artistic talent and to provide intensive arts experiences in music, dance, theater, and the visual arts for talented students aged 14-18. (AM)

  14. How to Spend Your Summer Vacation.

    ERIC Educational Resources Information Center

    Louviere, James P.; Mungas, Jenny

    1994-01-01

    A high school senior describes her adventures as part of an eight-week glacier expedition in Alaska and British Columbia. Also includes information on how to obtain unique summer enrichment opportunities for teachers and students. (ZWH)

  15. Evolution of dynamic and thermodynamic fields during the Indian summer monsoon onset in the initialised atmosphere-ocean seasonal forecasting model of the UK Met Office

    NASA Astrophysics Data System (ADS)

    Menon, Arathy; Turner, Andrew; Martin, Gill

    2016-04-01

    The onset of the Indian summer monsoon has significant influence on the agricultural planning that affects food production and the gross domestic product of the country. Hence understanding and prediction of the monsoon onset is of paramount importance. Here we use hindcast simulations from the Met Office fully coupled atmosphere-ocean Global Seasonal Forecast System 5 (GloSea5) to study the monsoon onset over India. The GloSea5 hindcast simulations are produced for three different start dates in late April or early May prior to the monsoon season and the atmosphere and ocean components are both initialized. Rather than focus on skill metrics of the performance at simulating the onset timing, we use common objective indices of the onset circulation and wind shears in the meridional (Wang-Fan) and vertical (Webster-Yang) directions to determine the monsoon onset over India. We find that the dynamic indices obtained from GloSea5 ensemble mean are consistent with those from the ERA-Interim reanalysis dataset. GloSea5 is also very effective in capturing the spatial pattern of the monsoon rainfall progression following the onset. We next analyse the composite evolution of various dynamic and thermodynamic fields associated with these indices, focusing on recent findings suggesting the importance of dry air incursions above the surface from the northwest. We further extend our analysis by looking at the physical mechanisms leading to onset in the GloSea5 simulations, and examine case studies comparing late and early onset years in both the model hindcasts and reanalysis data.

  16. Summer Events at the Scientific Library | Poster

    Cancer.gov

    Two exciting events are coming this summer from the Scientific Library—the annual Student Science Jeopardy Tournament and the Summer Video Series. This year, the 10th Annual Student Science Jeopardy Tournament will be held on Wednesday, July 20, beginning at 10 a.m. in the auditorium of Building 549. The event will also be streamed live to the Advanced Technology Research Facility (ATRF), room E1203.

  17. 1895: Dr W G Grace's golden summer.

    PubMed Central

    Toghill, P.

    1995-01-01

    One hundred years ago there was another wonderful summer. Dr. W G Grace, England's greatest cricketer, in his 47th year, completed his "century of centuries" and scored 2346 runs. This remarkable achievement was celebrated with enthusiasm and affection by the Victorian public. In more practical terms generous testimonials raised 9073 pound sterling 8s 6d, which made it a golden summer in more ways than one. Images p618-a PMID:7663257

  18. Observed evidence of the anomalous South China Sea western boundary current during the summers of 2010 and 2011

    NASA Astrophysics Data System (ADS)

    Shu, Yeqiang; Xue, Huijie; Wang, Dongxiao; Xie, Qiang; Chen, Ju; Li, Jian; Chen, Rongyu; He, Yunkai; Li, Daning

    2016-02-01

    Seven years of directly measured current data from a mooring in the Xisha area of the South China Sea (SCS), together with shipboard ADCP and satellite data, have shown the western boundary current (WBC) anomaly and its vertical structure during the summers of 2010 and 2011. The observed WBC presented obvious year-to-year variability, especially in the summer. Overall, the summer mean velocity at the mooring site over 7-year (2007-2013) was northeastward. The moored ADCP showed that the northeastward velocity was particularly strong in the summer of 2010, but the increase was confined in the upper 120 m. In contrast, the northeastward current disappeared throughout the observed depth range (from 50 to 450 m) in the summer of 2011. Even at the deepest observed position, the monthly velocity anomalies reached 14 cm s-1 westward and 12 cm s-1 southward in the zonal and meridional directions, respectively. Both the Vietnam offshore current (VOC) and double gyres in the western SCS disappeared and the southern anticyclonic gyre expanded to strengthened the northward WBC in the summer of 2010. However, in summer of 2011, the VOC intensified, and the northern cyclonic gyre enlarged with its northern edge reaching 18°N, slightly north of mooring site, which weakened the northeastward WBC. The observed SCS circulation anomalies during 2010 and 2011 were mainly induced by the basin-scale wind field anomalies associated with the 2009/2010 El Niño and 2010/2011 La Niña.

  19. Regional tree growth and inferred summer climate in the Winnipeg River basin, Canada, since AD 1783

    NASA Astrophysics Data System (ADS)

    St. George, Scott; Meko, David M.; Evans, Michael N.

    2008-09-01

    A network of 54 ring-width chronologies is used to estimate changes in summer climate within the Winnipeg River basin, Canada, since AD 1783. The basin drains parts of northwestern Ontario, northern Minnesota and southeastern Manitoba, and is a key area for hydroelectric power production. Most chronologies were developed from Pinus resinosa and P. strobus, with a limited number of Thuja occidentalis, Picea glauca and Pinus banksiana. The dominant pattern of regional tree growth can be recovered using only the nine longest chronologies, and is not affected by the method used to remove variability related to age or stand dynamics from individual trees. Tree growth is significantly, but weakly, correlated with both temperature (negatively) and precipitation (positively) during summer. Simulated ring-width chronologies produced by a process model of tree-ring growth exhibit similar relationships with summer climate. High and low growth across the region is associated with cool/wet and warm/dry summers, respectively; this relationship is supported by comparisons with archival records from early 19th century fur-trading posts. The tree-ring record indicates that summer droughts were more persistent in the 19th and late 18th century, but there is no evidence that drought was more extreme prior to the onset of direct monitoring.

  20. Drier summers cancel out the CO2 uptake enhancement induced by warmer springs.

    PubMed

    Angert, A; Biraud, S; Bonfils, C; Henning, C C; Buermann, W; Pinzon, J; Tucker, C J; Fung, I

    2005-08-01

    An increase in photosynthetic activity of the northern hemisphere terrestrial vegetation, as derived from satellite observations, has been reported in previous studies. The amplitude of the seasonal cycle of the annually detrended atmospheric CO(2) in the northern hemisphere (an indicator of biospheric activity) also increased during that period. We found, by analyzing the annually detrended CO(2) record by season, that early summer (June) CO(2) concentrations indeed decreased from 1985 to 1991, and they have continued to decrease from 1994 up to 2002. This decrease indicates accelerating springtime net CO(2) uptake. However, the CO(2) minimum concentration in late summer (an indicator of net growing-season uptake) showed no positive trend since 1994, indicating that lower net CO(2) uptake during summer cancelled out the enhanced uptake during spring. Using a recent satellite normalized difference vegetation index data set and climate data, we show that this lower summer uptake is probably the result of hotter and drier summers in both mid and high latitudes, demonstrating that a warming climate does not necessarily lead to higher CO(2) growing-season uptake, even in high-latitude ecosystems that are considered to be temperature limited.

  1. Physics and the Vertical Jump

    ERIC Educational Resources Information Center

    Offenbacher, Elmer L.

    1970-01-01

    The physics of vertical jumping is described as an interesting illustration for motivating students in a general physics course to master the kinematics and dynamics of one dimensional motion. The author suggests that mastery of the physical principles of the jump may promote understanding of certain biological phenomena, aspects of physical…

  2. Vertical transmission of Theileria lestoquardi in sheep.

    PubMed

    Zakian, Amir; Nouri, Mohammad; Barati, Farid; Kahroba, Hooman; Jolodar, Abbas; Rashidi, Fardokht

    2014-07-14

    This is the first report of an outbreak of Theileria lestoquardi abortion and stillbirth in a mob of 450 ewes in July 2012, during which, approximately 35 late-term ewes lost their fetuses over a 5-day period. A dead ewe and her aborted fetus were transported to the Ahvaz Veterinary Hospital for the diagnostic evaluation. The microbial cultures from the ewe vaginal discharges and fetal abomasal contents and the liver were negative. The blood films of the ewe and her fetus contained Theileria piroplasms and the impression smears from ewe liver and fetal spleen were positive for Theileria Koch blue bodies. The DNA was extracted from the liver and spleen of ewe and her fetus, respectively, and analyzed by polymerase chain reaction (PCR) using specific primers derived from the nucleotide sequences of 18S ribosomal DNA (rDNA) gene of T. lestoquardi. A single fragment of 428-bp fragment was amplified. The PCR product was directly sequenced and the alignment of the sequence with similar sequences in GenBank(®) showed 100% identities with 18S rDNA gene of T. lestoquardi. The present study is the first report of the T. lestoquardi vertical transmission that could be related to the abortion.

  3. Effects of cumulus parameterization closures on simulations of summer precipitation over the continental United States

    NASA Astrophysics Data System (ADS)

    Qiao, Fengxue; Liang, Xin-Zhong

    2016-09-01

    This study examines the effects of five cumulus closure assumptions on simulations of summer precipitation in the continental U.S. by utilizing an ensemble cumulus parameterization (ECP) that incorporates multiple alternate closure schemes into a single cloud model formulation. Results demonstrate that closure algorithms significantly affect the summer mean, daily frequency and intensity, and diurnal variation of precipitation, with strong regional dependence. Overall, the vertical velocity (W) closure produces the smallest summer mean biases, while the moisture convergence (MC) closure most realistically reproduces daily variability. Both closures have advantages over others in simulating U.S. daily rainfall frequency distribution, though both slightly overestimate intense rain events. The MC closure is superior at capturing summer rainfall amount, daily variability, and heavy rainfall frequency over the Central U.S., but systematically produces wet biases over the North American Monsoon (NAM) region and Southeast U.S., which can be reduced by using the W closure. The instability tendency (TD) and the total instability adjustment (KF) closures are better at capturing observed diurnal signals over the Central U.S. and the NAM, respectively. The results reasonably explain the systematic behaviors of several major cumulus parameterizations. A preliminary experiment combining two optimal closures (averaged moisture convergence and vertical velocity) in the ECP scheme significantly reduced the wet (dry) biases over the Southeast U.S. in the summer of 1993 (2003), and greatly improved daily rainfall correlations over the NAM. Further improved model simulation skills may be achieved in the future if optimal closures and their appropriate weights can be derived at different time scales based on specific climate regimes.

  4. Vertical Sextants give Good Sights

    NASA Astrophysics Data System (ADS)

    Dixon, Mark

    Many texts stress the need for marine sextants to be held precisely vertical at the instant that the altitude of a heavenly body is measured. Several authors lay particular emphasis on the technique of the instrument in a small arc about the horizontal axis to obtain a good sight. Nobody, to the author's knowledge, however, has attempted to quantify the errors involved, so as to compare them with other errors inherent in determining celestial position lines. This paper sets out to address these issues and to pose the question: what level of accuracy of vertical alignment can reasonably be expected during marine sextant work at sea ?When a heavenly body is brought to tangency with the visible horizon it is particularly important to ensure that the sextant is held in a truly vertical position. To this end the instrument is rocked gently about the horizontal so that the image of the body describes a small arc in the observer's field of vision. As Bruce Bauer points out, tangency with the horizon must be achieved during the process of rocking and not a second or so after rocking has been discontinued. The altitude is recorded for the instant that the body kisses the visible horizon at the lowest point of the rocking arc, as in Fig. 2. The only other visual clue as to whether the sextant is vertical is provided by the right angle made by the vertical edge of the horizon glass mirror with the horizon. There may also be some input from the observer's sense of balance and his hand orientation.

  5. Effect of groundwater springs on NO3/- concentrations during summer in Catskill Mountain streams

    USGS Publications Warehouse

    Burns, Douglas A.; Murdoch, Peter S.; Lawrence, G.B.; Michel, R.L.

    1998-01-01

    Groundwater and stream water data collected at three headwater catchments in the Neversink River watershed indicate that base flow is sustained by groundwater from two sources: a shallow flow system within the till and soil and a deep flow system within bedrock fractures and bedding planes that discharges as perennial springs. Data from eight wells finished near the till/bedrock interface indicate that saturated conditions are not maintained in the shallow flow system during most summers. In contrast, the discharge of a perennial spring remained constant during two summer rainstorms, providing evidence that the deep flow system is disconnected from the shallow flow system in summer. Discharge from perennial springs was the principal source of streamflow in a headwater reach during low flow. Mean NO3/- concentrations were 20-25 ??mol L-1 in five perennial springs during the summer but only 5-10 ??mol L-1 in shallow groundwater. Thus the deep flow system does not reflect typical NO3/- concentrations in the soil during summer. A hydrologic budget at a headwater drainage reveals that March and late fall are the principal groundwater recharge periods. Residence time modeling based on analyses of 18O and 35S indicates that groundwater in the deep flow system is 6-22 months old. These data indicate that summer base flow largely originates from previous dormant seasons when available soil NO3/- is greater. In these Catskill watersheds, high base flow concentrations of NO3/- during summer do not provide sufficient evidence that the atmospheric N deposition rate exceeds the demand of terrestrial vegetation.

  6. Effect of groundwater springs on NO3- concentrations during summer in Catskill Mountain streams

    NASA Astrophysics Data System (ADS)

    Burns, Douglas A.; Murdoch, Peter S.; Lawrence, Gregory B.; Michel, Robert L.

    1998-08-01

    Groundwater and stream water data collected at three headwater catchments in the Neversink River watershed indicate that base flow is sustained by groundwater from two sources: a shallow flow system within the till and soil and a deep flow system within bedrock fractures and bedding planes that discharges as perennial springs. Data from eight wells finished near the till/bedrock interface indicate that saturated conditions are not maintained in the shallow flow system during most summers. In contrast, the discharge of a perennial spring remained constant during two summer rainstorms, providing evidence that the deep flow system is disconnected from the shallow flow system in summer. Discharge from perennial springs was the principal source of streamflow in a headwater reach during low flow. Mean NO3- concentrations were 20-25 μmol L-1 in five perennial springs during the summer but only 5-10 μmol L-1 in shallow groundwater. Thus the deep flow system does not reflect typical NO3- concentrations in the soil during summer. A hydrologic budget at a headwater drainage reveals that March and late fall are the principal groundwater recharge periods. Residence time modeling based on analyses of 18O and 35S indicates that groundwater in the deep flow system is 6-22 months old. These data indicate that summer base flow largely originates from previous dormant seasons when available soil NO3- is greater. In these Catskill watersheds, high base flow concentrations of NO3- during summer do not provide sufficient evidence that the atmospheric N deposition rate exceeds the demand of terrestrial vegetation.

  7. Abrupt change of the mid-summer climate in central east China by the influence of atmospheric pollution

    NASA Astrophysics Data System (ADS)

    Xu, Qun

    Following the great flooding of summer 1998, the mid-lower Yangtze Basin further suffered from another large flooding in summer 1999. Successive droughts through 3 recent summers (1997-1999) appeared in north China in addition, leading to an abnormal summer climate pattern of "north drought with south flooding". Such southward move of the summer monsoon rainy belt in east China started in the late 1970s-early 1980s. Its main cause may not be a purely natural climate change, but the acceleration of industrialization in east China could play a major role by emitting large volumes of SO 2, especially from the rapidly growing rural factories of east China. The annual release of SO 2 in China exceeded 20 Tg during 1992-1998, so dense sulfate aerosols covered the central east China which significantly reduced the sunlight. Although present estimates for the changes of clear sky global solar radiation may include some error, they show that the negative radiative forcing of sulfate aerosols in central east China by far exceeds the effect of greenhouse warming in summer. Hence the mid-summer monsoon rainy belt of east China has a trend moving southward in 21 recent years (1979-1999), showing the very sensitive characteristic of the summer monsoon system to the change in heat equilibrium of the land surface. The occurrence rate of summer climate pattern of "north drought with south flooding" in east China during 21 recent years is the largest since AD 950; such anomalous climate has brought large losses to China. The only possible way to reverse this southward trend of summer monsoon rainy belt is to significantly reduce air pollution by using more clean energy. Recently, the PRC has paid serious attention to this problem by adopting a series of countermeasures.

  8. Seasonal variations in vertical migration of glacier lanternfish, Benthosema glaciale.

    PubMed

    Dypvik, Eivind; Røstad, Anders; Kaartvedt, Stein

    2012-01-01

    The seasonal variations in glacier lanternfish (Benthosema glaciale) vertical distribution and diel vertical migration (DVM) were studied by use of a bottom-mounted upward-facing 38 kHz echo sounder deployed at 392 m depth and cabled to shore in Masfjorden (~60°52'N, ~5°24'E), Norway. Acoustic data from July 2007-October 2008 were analyzed, and scattering layers below ~220 m during daytime were attributed to glacier lanternfish based on net sampling in this, and previous studies, as well as from analysis of the acoustic data. At these depths, three different diel behavioral strategies were apparent: normal diel vertical migration (NDVM), inverse DVM (IDVM), and no DVM (NoDVM). NoDVM was present all year, while IDVM was present in autumn and winter, and NDVM was present during spring and summer. The seasonal differences in DVM behavior seem to correlate with previously established seasonal distribution of prey. We hypothesize that in regions with seasonally migrating zooplankton, such as where calanoid copepods overwinter at depth, similar plasticity in DVM behavior might occur in other populations of lanternfishes.

  9. Seasonal variations in vertical migration of glacier lanternfish, Benthosema glaciale.

    PubMed

    Dypvik, Eivind; Røstad, Anders; Kaartvedt, Stein

    2012-01-01

    The seasonal variations in glacier lanternfish (Benthosema glaciale) vertical distribution and diel vertical migration (DVM) were studied by use of a bottom-mounted upward-facing 38 kHz echo sounder deployed at 392 m depth and cabled to shore in Masfjorden (~60°52'N, ~5°24'E), Norway. Acoustic data from July 2007-October 2008 were analyzed, and scattering layers below ~220 m during daytime were attributed to glacier lanternfish based on net sampling in this, and previous studies, as well as from analysis of the acoustic data. At these depths, three different diel behavioral strategies were apparent: normal diel vertical migration (NDVM), inverse DVM (IDVM), and no DVM (NoDVM). NoDVM was present all year, while IDVM was present in autumn and winter, and NDVM was present during spring and summer. The seasonal differences in DVM behavior seem to correlate with previously established seasonal distribution of prey. We hypothesize that in regions with seasonally migrating zooplankton, such as where calanoid copepods overwinter at depth, similar plasticity in DVM behavior might occur in other populations of lanternfishes. PMID:24391274

  10. Late Cretaceous sea level from a paleoshoreline

    SciTech Connect

    McDonough, K.J.; Cross, T.A. )

    1991-04-10

    The contemporary elevation of a Late Cenomanian ({approx}93 Ma) shoreline was determined at five localities along the tectonically stable, eastern margin of the Cretaceous Western Interior Seaway, North America. This shoreline, represented by marine-to-nonmarine facies transitions in strata of the Greenhorn sequence (UZA-2 cycle of Haq et al. (1987)), was identified from outcrop and borehole data. Biostratigraphic zonations constrained the geologic age at each locality. Sequence stratigraphic correlations, based on identifying discrete progradational units and the surfaces that separate them, were used to refine age correlations to better than 100 kyr between localities. A single Cenomanian shoreline was correlated within a single progradational unit, and its elevation was determined at five localities. This paleostrandline occurs 265-286m above present-day sea level, at an average elevation of 276 m. Isostatic and flexural corrections were applied to remove the effects of postdepositional vertical movement, including sediment compaction by loading, uplift due to erosion, and glacial loading and rebound. Errors inherent in each measurement and each correction were estimated. Corrections and their cumulative error estimates yield a Late Cenomanian elevation of 269{plus minus}87 m above present sea level. The corrected elevation approximates sea level at 93 Ma and provides a measure of Late Cenomanian eustasy prior to the Early Turonian highstand. Establishing the absolute value for eustasy at a single point in geologic time provides a frame of reference for calibrating relative sea level curves, as well as constraining the magnitudes of tectonic subsidence, sediment flux, and other variables that controlled water depth and relative sea level.

  11. Late glacial climate estimates for southern Nevada: The ostracode fossil record

    SciTech Connect

    Forester, R.M.; Smith, A.J.

    1995-10-01

    Climate change plays an important role in determining as possible long term hydrological performance of the potential high level nuclear waste repository within Yucca Mountain, Nevada. Present-day global circulation results in this region having an arid to semi-arid climate characterized by hot and relatively dry summers. Global circulation during the late glacial (about 14 to 20 ka) was very different from the present-day. Preliminary study of late-glacial fossil ostracodes from {open_quotes}marsh deposits{close_quotes} in the upper Las Vegas Valley suggests mean annual precipitation may have been four times higher, while mean annual temperature may have been about 10{degrees}C cooler than today. A major difference between present-day and late-glacial climate was likely the existence of cooler, cloudier, and wetter summers in the past.

  12. Ionospheric vertical drift response at a mid-latitude station

    NASA Astrophysics Data System (ADS)

    Kouba, Daniel; Koucká Knížová, Petra

    2016-07-01

    Vertical plasma drift data measured at a mid-latitude ionospheric station Pruhonice (50.0 ° N, 14.6 ° E) were collected and analysed for the year 2006, a year of low solar and geomagnetic activity. Hence these data provide insight into the drift behaviour during quiet conditions. The following typical diurnal trend is evident: a significant decay to negative values (downward peak) at dawn; generally less pronounced downward peak at dusk hours. Magnitude of the downward drift varies during the year. Typically it reaches values about 20 ms-1 at dawn hours and 10 ms-1 at dusk hours. Maximum dawn magnitude of about 40 ms-1 has been detected in August. During daytime the vertical drifts increases from the initial small downward drifts to zero drift around noon and to small upward drifts in the afternoon. Night-time drift values display large variability around a near zero vertical drift average. There is a significant trend to larger downward drift values near dawn and a less pronounced decrease of the afternoon upward vertical drifts near sunset. Two regular downward peaks of the drift associated with the dawn and dusk are general characteristics of the analysed data throughout the year 2006. Their seasonal course corresponds to the seasonal course of the sunrise and sunset. The duration of prevailing negative drift velocities forming these peaks and thus the influence of the dawn/dusk on the drift velocity is mostly 1.5-3 h. The dawn effect on vertical drift tends to be larger than the effect of the dusk. The observed magnitude of the sunrise and sunset peaks show significant annual course. The highest variability of the magnitude is seen during winter. High variability is detected till March equinox and again after September equinox. Around solstice, both peaks reaches lowest values. After that, the magnitudes of the drift velocity increase smoothly till maxima in summer (August). The vertical drift velocity course is smooth between June solstice and September

  13. Large-scale urbanization effects on eastern Asian summer monsoon circulation and climate

    NASA Astrophysics Data System (ADS)

    Chen, Haishan; Zhang, Ye; Yu, Miao; Hua, Wenjian; Sun, Shanlei; Li, Xing; Gao, Chujie

    2016-07-01

    Impacts of large-scale urbanization over eastern China on East Asian summer monsoon circulation and climate are investigated by comparing three 25-year climate simulations with and without incorporating modified land cover maps reflecting two different idealized large-scale urbanization scenarios. The global atmospheric general circulation model CAM4.0 that includes an urban canopy parameterization scheme is employed in this study. The large-scale urbanization over eastern China leads to a significant warming over most of the expanded urban areas, characterized by an increase of 3 K for surface skin temperature, 2.25 K for surface air temperature, significant warming of both daily minimum and daily maximum air temperatures, and 0.4 K for the averaged urban-rural temperature difference. The urbanization is also accompanied by an increase in surface sensible heat flux, a decrease of the net surface shortwave and long-wave radiation, and an enhanced surface thermal heating to the atmosphere in most Eastern Asia areas. It is noted that the responses of the East Asian summer monsoon circulation exhibits an evident month-to-month variation. Across eastern China, the summer monsoon in early summer is strengthened by the large-scale urbanization, but weakened (intensified) over southern (northern) part of East Asia in late summer. Meanwhile, early summer precipitation is intensified in northern and northeastern China and suppressed in south of ~35°N, but late summer precipitation is evidently suppressed over northeast China, the Korean Peninsula and Japan with enhancements in southern China, the South China Sea, and the oceanic region south and southeast of the Taiwan Island. This study highlights the evidently distinct month-to-month responses of the monsoon system to the large-scale urbanization, which might be attributed to different basic states, internal feedbacks (cloud, rainfall) as well as a dynamic adjustment of the atmosphere. Further investigation is required

  14. Seasonal changes in partial, reverse diel vertical migrations of cisco Coregonus artedi.

    PubMed

    Ahrenstorff, T D; Hrabik, T R

    2016-09-01

    The objectives of this study were to (1) document changes in partial, reverse diel vertical migrations (DVM) patterns of cisco Coregonus artedi in Ten Mile Lake, MN, U.S.A., throughout the year and (2) evaluate the mechanisms that may cause shifts in migration behaviour. Results indicated that C. artedi vertical distributions remained deep in the water column during the day and night of the spring and autumn, which was related to a low risk, low reward strategy. During summer, a partial migration occurred where a portion of the population remained deeper according to the low risk, low reward strategy, while the other portion performed a more extensive high risk, high reward reverse DVM. In winter, C. artedi did not migrate because there were only low risk, low reward conditions present at all depths. The extensive partial, reverse DVM during summer probably increased the growth potential of C. artedi, helping individuals survive in a lake with low zooplankton prey resources. PMID:27455948

  15. Seasonal changes in partial, reverse diel vertical migrations of cisco Coregonus artedi.

    PubMed

    Ahrenstorff, T D; Hrabik, T R

    2016-09-01

    The objectives of this study were to (1) document changes in partial, reverse diel vertical migrations (DVM) patterns of cisco Coregonus artedi in Ten Mile Lake, MN, U.S.A., throughout the year and (2) evaluate the mechanisms that may cause shifts in migration behaviour. Results indicated that C. artedi vertical distributions remained deep in the water column during the day and night of the spring and autumn, which was related to a low risk, low reward strategy. During summer, a partial migration occurred where a portion of the population remained deeper according to the low risk, low reward strategy, while the other portion performed a more extensive high risk, high reward reverse DVM. In winter, C. artedi did not migrate because there were only low risk, low reward conditions present at all depths. The extensive partial, reverse DVM during summer probably increased the growth potential of C. artedi, helping individuals survive in a lake with low zooplankton prey resources.

  16. Coastal influence on vertical pollutant partitioning

    NASA Astrophysics Data System (ADS)

    Peake, D.

    Coastal outflow describes the horizontal ventilation of pollutants from the continental boundary layer (CBL) by advection above the shallower marine boundary layer. Passive tracers incorporated in the Met Office Unified Model (MetUM) are used to simulate coastal outflow over the eastern United States for the summer of 2004. The results are interpreted with a simple box-model containing a diurnally varying CBL height and uniform wind flow. Ventilation by coastal outflow from the US occurs at the same magnitude as vertical ventilation into the free troposphere for the eastern half of the US. The diurnal variability in coastal outflow is determined by the lifetime of the tracer and the cycle of CBL height. Over the diurnal cycle, pollutants with lifetimes less than 24 hours experience a maximum in the evening and a minimum in the mid-morning. Pollutants with lifetimes greater than 24 hours undergo continuous coastal outflow with little diurnal variability. The dominant parameters in this study are tracer lifetime α, wind-speed U and width of emissions (i.e. land) L. The box-model indicates the presence of a critical threshold, αU/L ≈ 10, above which increasing the cross-coastal wind speed decreases coastal out-flow by reducing the availability of tracer in the residual layer to undergo coastal outflow at night. Of tracer advected across the coast in the MetUM simulation, 65% and 67% of tracer with 3- and 24-hour lifetimes undergo coastal outflow respectively. For the 24-hour tracer, the box-model has the highest correlation with the MetUM simulation when the advection rate U/L≈ 2 x 10-5s-1. Given the observed wind speed the distance near the coast over which emissions significantly contribute to coastal outflow is ≈ 100-110km.

  17. Spirit Near 'Stapledon' on Sol 1802 (Vertical)

    NASA Technical Reports Server (NTRS)

    2009-01-01

    NASA Mars Exploration Rover Spirit used its navigation camera for the images assembled into this full-circle view of the rover's surroundings during the 1,802nd Martian day, or sol, (January 26, 2009) of Spirit's mission on the surface of Mars. North is at the top.

    This view is presented as a vertical projection with geometric seam correction.

    Spirit had driven down off the low plateau called 'Home Plate' on Sol 1782 (January 6, 2009) after spending 12 months on a north-facing slope on the northern edge of Home Plate. The position on the slope (at about the 9-o'clock position in this view) tilted Spirit's solar panels toward the sun, enabling the rover to generate enough electricity to survive its third Martian winter. Tracks at about the 11-o'clock position of this panorama can be seen leading back to that 'Winter Haven 3' site from the Sol 1802 position about 10 meters (33 feet) away. For scale, the distance between the parallel wheel tracks is about one meter (40 inches).

    Where the receding tracks bend to the left, a circular pattern resulted from Spirit turning in place at a soil target informally named 'Stapledon' after William Olaf Stapledon, a British philosopher and science-fiction author who lived from 1886 to 1950. Scientists on the rover team suspected that the soil in that area might have a high concentration of silica, resembling a high-silica soil patch discovered east of Home Plate in 2007. Bright material visible in the track furthest to the right was examined with Spirit's alpha partical X-ray spectrometer and found, indeed, to be rich in silica.

    The team laid plans to drive Spirit from this Sol 1802 location back up onto Home Plate, then southward for the rover's summer field season.

  18. Observations of the summer Red Sea circulation

    NASA Astrophysics Data System (ADS)

    Sofianos, Sarantis S.; Johns, William E.

    2007-06-01

    Aiming at exploring and understanding the summer circulation in the Red Sea, a cruise was conducted in the basin during the summer of 2001 involving hydrographic, meteorological, and direct current observations. The most prominent feature, characteristic of the summer circulation and exchange with the Indian Ocean, is a temperature, salinity, and oxygen minimum located around a depth of 75 m at the southern end of the basin, associated with Gulf of Aden Intermediate Water inflowing from the Gulf of Aden during the summer season as an intruding subsurface layer. Stirring and mixing with ambient waters lead to marked increases in temperature (from 16.5 to almost 33°C) and salinity (from 35.7 to more than 38 psu) in this layer by the time it reaches midbasin. The observed circulation presents a very vigorous pattern with strong variability and intense features that extend the width of the basin. A permanent cyclone, detected in the northern Red Sea, verifies previous observations and modeling studies, while in the central sector of the basin a series of very strong anticyclones were observed with maximum velocities exceeding 1 m/s. The three-layer flow pattern, representative of the summer exchange between the Red Sea and the Gulf of Aden, is observed in the strait of Bab el Mandeb. In the southern part of the basin the layer flow is characterized by strong banking of the inflows and outflows against the coasts. Both surface and intermediate water masses involved in the summer Red Sea circulation present prominent spatial variability in their characteristics, indicating that the eddy field and mixing processes play an important role in the summer Red Sea circulation.

  19. Four Views of Mars in Northern Summer

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Four faces of Mars as seen on March 30, 1997 are presented in this montage of NASA Hubble Space Telescope images. Proceeding in the order upper-left, upper-right, lower-left, lower-right, Mars has rotated about ninety degrees between each successive time step. For example the Tharsis volcanoes, which are seen (between 7:30 and 9 o'clock positions) in mid-morning in the UPPER-RIGHT view, are seen near the late afternoon edge of the planet (about 3 o'clock position) in the lower-left image. All of these color images are composed of individual red (673 nanometers), green (502 nm), and blue (410 nm) Planetary Camera exposures.

    Upper left: This view is centered on Ares Valles, where Pathfinder will land on July 4, 1997; the Valles Marineris canyon system stretches to the west across the lower left portion of the planet, while the bright, orangish desert of Arabia Planitia is to the east. The bright polar water-ice cap, surrounded by a dark ring of sand dunes, is obvious in the north; since it is northern summer and the pole is tilted toward us, the residual north polar cap is seen in its entirety in all four images. Acidalia Planitia, the prominent dark area fanning southward from the polar region, is thought to have a surface covered with dark sand. Numerous 'dark wind streaks' are visible to the south of Acidalia, resulting from wind-blown sand streaming out of the interiors of craters.

    Upper right: The Tharsis volcanos and associated clouds are prominent in the western half of this view. Olympus Mons, spanning 340 miles (550 km) across its base and reaching an elevation of 16 miles (25 km), extends through the cloud deck near the western limb, while (from the south) Arsia Mons, Pavonis Mons, and Ascraeus Mons are to the west of center. Valles Marineris stretches to the east, and the Pathfinder landing site is shrouded in clouds near the afternoon limb.

    Lower left: This relatively featureless sector of Mars stretches from the Elysium volcanic region in the

  20. Illusory Late Heavy Bombardments.

    PubMed

    Boehnke, Patrick; Harrison, T Mark

    2016-09-27

    The Late Heavy Bombardment (LHB), a hypothesized impact spike at ∼3.9 Ga, is one of the major scientific concepts to emerge from Apollo-era lunar exploration. A significant portion of the evidence for the existence of the LHB comes from histograms of (40)Ar/(39)Ar "plateau" ages (i.e., regions selected on the basis of apparent isochroneity). However, due to lunar magmatism and overprinting from subsequent impact events, virtually all Apollo-era samples show evidence for (40)Ar/(39)Ar age spectrum disturbances, leaving open the possibility that partial (40)Ar* resetting could bias interpretation of bombardment histories due to plateaus yielding misleadingly young ages. We examine this possibility through a physical model of (40)Ar* diffusion in Apollo samples and test the uniqueness of the impact histories obtained by inverting plateau age histograms. Our results show that plateau histograms tend to yield age peaks, even in those cases where the input impact curve did not contain such a spike, in part due to the episodic nature of lunar crust or parent body formation. Restated, monotonically declining impact histories yield apparent age peaks that could be misinterpreted as LHB-type events. We further conclude that the assignment of apparent (40)Ar/(39)Ar plateau ages bears an undesirably high degree of subjectivity. When compounded by inappropriate interpretations of histograms constructed from plateau ages, interpretation of apparent, but illusory, impact spikes is likely. PMID:27621460

  1. Illusory Late Heavy Bombardments.

    PubMed

    Boehnke, Patrick; Harrison, T Mark

    2016-09-27

    The Late Heavy Bombardment (LHB), a hypothesized impact spike at ∼3.9 Ga, is one of the major scientific concepts to emerge from Apollo-era lunar exploration. A significant portion of the evidence for the existence of the LHB comes from histograms of (40)Ar/(39)Ar "plateau" ages (i.e., regions selected on the basis of apparent isochroneity). However, due to lunar magmatism and overprinting from subsequent impact events, virtually all Apollo-era samples show evidence for (40)Ar/(39)Ar age spectrum disturbances, leaving open the possibility that partial (40)Ar* resetting could bias interpretation of bombardment histories due to plateaus yielding misleadingly young ages. We examine this possibility through a physical model of (40)Ar* diffusion in Apollo samples and test the uniqueness of the impact histories obtained by inverting plateau age histograms. Our results show that plateau histograms tend to yield age peaks, even in those cases where the input impact curve did not contain such a spike, in part due to the episodic nature of lunar crust or parent body formation. Restated, monotonically declining impact histories yield apparent age peaks that could be misinterpreted as LHB-type events. We further conclude that the assignment of apparent (40)Ar/(39)Ar plateau ages bears an undesirably high degree of subjectivity. When compounded by inappropriate interpretations of histograms constructed from plateau ages, interpretation of apparent, but illusory, impact spikes is likely.

  2. Modeling late Paleozoic glaciation

    SciTech Connect

    Crowley, T.J.; Baum, S.K. )

    1992-06-01

    Late Paleozoic glaciation on Gondwana is associated with changes in geography, solar luminosity, and estimated CO{sub 2} levels. To assess the relative importance of these boundary conditions, the authors conducted a suite of climate model simulations for the periods before, during, and after peak mid-Carboniferous ({approximately}300 Ma) glaciation (340, 300, and 255 and 225 Ma, respectively). Orbital insolation values favorable for glaciation and interglaciation were used for each time interval. Results indicate that changes in geography cause significant changes in snow area, but the temporal trend is not consistent with the geologic record for glaciation. Combined CO{sub 2}-plus-geography changes yield the best agreement with observations. In addition, interglacial orbital configurations result in almost ice-free conditions for the glacial interval at 300 Ma, at a time of low CO{sub 2}. The large simulated glacial-interglacial snowline fluctuations for Permian-Carboniferous time may explain cyclothem fluctuations at these times. Overall, results support the importance of the CO{sub 2} paradigm, but also indicate that a fuller understanding of past climate change requires consideration of paleogeographic, luminosity, and orbital insolation changes.

  3. Vertically Integrated Circuits at Fermilab

    SciTech Connect

    Deptuch, Grzegorz; Demarteau, Marcel; Hoff, James; Lipton, Ronald; Shenai, Alpana; Trimpl, Marcel; Yarema, Raymond; Zimmerman, Tom; /Fermilab

    2009-01-01

    The exploration of the vertically integrated circuits, also commonly known as 3D-IC technology, for applications in radiation detection started at Fermilab in 2006. This paper examines the opportunities that vertical integration offers by looking at various 3D designs that have been completed by Fermilab. The emphasis is on opportunities that are presented by through silicon vias (TSV), wafer and circuit thinning and finally fusion bonding techniques to replace conventional bump bonding. Early work by Fermilab has led to an international consortium for the development of 3D-IC circuits for High Energy Physics. The consortium has submitted over 25 different designs for the Fermilab organized MPW run organized for the first time.

  4. Kinematic Fitting of Detached Vertices

    SciTech Connect

    Mattione, Paul

    2007-05-01

    The eg3 experiment at the Jefferson Lab CLAS detector aims to determine the existence of the $\\Xi_{5}$ pentaquarks and investigate the excited $\\Xi$ states. Specifically, the exotic $\\Xi_{5}^{--}$ pentaquark will be sought by first reconstructing the $\\Xi^{-}$ particle through its weak decays, $\\Xi^{-}\\to\\pi^{-}\\Lambda$ and $\\Lambda\\to\\pi^{-}$. A kinematic fitting routine was developed to reconstruct the detached vertices of these decays, where confidence level cuts on the fits are used to remove background events. Prior to fitting these decays, the exclusive reaction $\\gamma D\\rightarrow pp\\pi^{-}$ was studied in order to correct the track measurements and covariance matrices of the charged particles. The $\\Lambda\\rightarrow p\\pi^{-}$ and $\\Xi^{-}\\to\\pi^{-}\\Lambda$ decays were then investigated to demonstrate that the kinematic fitting routine reconstructs the decaying particles and their detached vertices correctly.

  5. Next generation vertical electrode cells

    NASA Astrophysics Data System (ADS)

    Brown, Craig

    2001-05-01

    The concept of the vertical electrode cell (VEC) for aluminum electrowinning is presented with reference to current research. Low-temperature electrolysis allows nonconsumable metal-alloy anodes to show ongoing promise in laboratory tests. The economic and environmental advantages of the VEC are surveyed. The unique challenges of bringing VEC technology into practice are discussed. The current status of laboratory research is summarized. New results presented show that commercial purity aluminum can be produced with promisingly high current efficiency.

  6. NASA-Ames vertical gun

    NASA Technical Reports Server (NTRS)

    Schultz, P. H.

    1984-01-01

    A national facility, the NASA-Ames vertical gun range (AVGR) has an excellent reputation for revealing fundamental aspects of impact cratering that provide important constraints for planetary processes. The current logistics in accessing the AVGR, some of the past and ongoing experimental programs and their relevance, and the future role of this facility in planetary studies are reviewed. Publications resulting from experiments with the gun (1979 to 1984) are listed as well as the researchers and subjects studied.

  7. Summer programming in rural communities: unique challenges.

    PubMed

    Phillips, Ruthellen; Harper, Stacey; Gamble, Susan

    2007-01-01

    During the past several decades, child poverty rates have been higher in rural than in urban areas, and now 2.5 million children live in deep poverty in rural America. Studies indicate that poor children are most affected by the typical "summer slide." Summer programming has the ability to address the issues of academic loss, nutritional loss, and the lack of safe and constructive enrichment activities. However, poor rural communities face three major challenges in implementing summer programming: community resources, human capital, and accessibility. The success of Energy Express, a statewide award-winning six-week summer reading and nutrition program in West Virginia, documents strategies for overcoming the challenges faced by poor, rural communities in providing summer programs. Energy Express (1) uses community collaboration to augment resources and develop community ownership, (2) builds human capital and reverses the acknowledged brain drain by engaging college students and community volunteers in meaningful service, and (3) increases accessibility through creative transportation strategies. West Virginia University Extension Service, the outreach arm of the land-grant institution, partners with AmeriCorps, a national service program, and various state and local agencies and organizations to implement a program that produces robust results. PMID:17623413

  8. Summer Schools in Nuclear and Radiochemistry

    SciTech Connect

    Silber, Herbert B.

    2013-06-20

    The ACS Summer Schools in Nuclear and Radiochemistry (herein called “Summer Schools”) were funded by the U.S. Department of Energy and held at San Jose State University (SJSU) and Brookhaven National Laboratory (BNL). The Summer Schools offer undergraduate students with U.S. citizenship an opportunity to complete coursework through ACS accredited chemistry degree programs at SJSU or the State University of New York at Stony Brook (SBU). The courses include lecture and laboratory work on the fundamentals and applications of nuclear and radiochemistry. The number of students participating at each site is limited to 12, and the low student-to-instructor ratio is needed due to the intense nature of the six-week program. To broaden the students’ perspectives on nuclear science, prominent research scientists active in nuclear and/or radiochemical research participate in a Guest Lecture Series. Symposia emphasizing environmental chemistry, nuclear medicine, and career opportunities are conducted as a part of the program. The Department of Energy’s Office of Basic Energy Sciences (BES) renewed the five-year proposal for the Summer Schools starting March 1, 2007, with contributions from Biological and Environmental Remediation (BER) and Nuclear Physics (NP). This Final Technical Report covers the Summer Schools held in the years 2007-2011.

  9. Summer programming in rural communities: unique challenges.

    PubMed

    Phillips, Ruthellen; Harper, Stacey; Gamble, Susan

    2007-01-01

    During the past several decades, child poverty rates have been higher in rural than in urban areas, and now 2.5 million children live in deep poverty in rural America. Studies indicate that poor children are most affected by the typical "summer slide." Summer programming has the ability to address the issues of academic loss, nutritional loss, and the lack of safe and constructive enrichment activities. However, poor rural communities face three major challenges in implementing summer programming: community resources, human capital, and accessibility. The success of Energy Express, a statewide award-winning six-week summer reading and nutrition program in West Virginia, documents strategies for overcoming the challenges faced by poor, rural communities in providing summer programs. Energy Express (1) uses community collaboration to augment resources and develop community ownership, (2) builds human capital and reverses the acknowledged brain drain by engaging college students and community volunteers in meaningful service, and (3) increases accessibility through creative transportation strategies. West Virginia University Extension Service, the outreach arm of the land-grant institution, partners with AmeriCorps, a national service program, and various state and local agencies and organizations to implement a program that produces robust results.

  10. Principal modes of Asian summer monsoon variability: Detection and changes

    NASA Astrophysics Data System (ADS)

    Yasutomi, N.; Kimoto, M.

    2009-12-01

    Principal modes of Asian summer monsoon variability are identified. By using vertically integrated moisture flux, principal modes represent better separation than commonly used variables such as rainfall, winds and outgoing longwave radiation. An empirical orthogonal function of vertically integrated moisture flux within the South, Southeast and East Asia during summertime is analysed. Results of various analyses let us convince that the first and second EOFs of the moisture flux are the principal modes of the Asian monsoon variability. In summer, there are two modes dominant in the Asian monsoon region; one consists of low-level circulation over the subtropical western Pacific near Philippines and associated convective dipole centers located over the western Pacific and Indonesia. The other consists of El Nino-Southern Oscillation (ENSO) signal and the Pacific-Japan (PJ) pattern, called ENSO-PJ mixed mode. This pattern is detected as the first EOF mode of a simulation with an atmospheric general circulation model giving the climatological mean sea surface temperature. Furthermore, the pattern is dominant in both present climate simulation and global warming simulation using coupled GCM. A projected change shows increasing of precipitation over South China and Japan. The Pacific-Indo dipole pattern is found out to be excited without external forcing like a specific sea surface temperature anomaly. Moreover, the Pacific-Indo dipole pattern appears as the preferred structure of variability by giving small perturbations to a three-dimensionally varying basic state in summertime by using a linear baroclinic model. Factors of the basic state which help to excite and maintain the Pacific-Indo dipole pattern are examined. Free, stationary Rossby waves can be excited in the region of low-level westerly extending from the Indian Ocean to the South China Sea which blows as a part of the monsoonal flow in summer. Rossby waves at the eastern end of the low-level westerly where

  11. What Is a Summer Job Worth? The Impact of Summer Youth Employment on Academic Outcomes

    ERIC Educational Resources Information Center

    Leos-Urbel, Jacob

    2014-01-01

    This paper estimates the impact of New York City's Summer Youth Employment Program (SYEP) on school attendance and other educational outcomes in the following school year for a large sample of low-income high school students. The program provides summer jobs and training to youth aged 14 to 21, and due to high demand allocates slots through a…

  12. Development in Mexico and Central America. Fulbright-Hays Summer Seminars Abroad Program. Summer 1991.

    ERIC Educational Resources Information Center

    Institute of International Education, New York, NY.

    This document features writings and curriculum projects by teachers who traveled to Mexico and Central America in the summer of 1991 as members of a Fulbright-Hays Summer Seminar. The following items are among the 20 included: Curriculum Project: "'Escritoras Mexicanas Contemporaneas': A Survey of Mexican Women Fiction Writers" (Laura J. Beard);…

  13. Parker Migrant Summer Story. A Report from Parker Summer School Migrant Program: Kindergarten Through Grade Six.

    ERIC Educational Resources Information Center

    Pollard, Merel E., Comp.

    Before the beginning of the summer school, a workshop was held for the teachers and aides to present ways to: (1) make migrant and American Indian children more aware of their heritage and (2) help them become more familiar with career possibilities. Objectives of the summer program were: (1) career exploration; (2) cultural enrichment (i.e., art,…

  14. [Seasonal Provincial Characteristics of Vertical Distribution of Dust Loadings and Heavy Metals near Surface in City].

    PubMed

    Li, Xiao-yan; Zhang, Shu-ting

    2015-06-01

    With the emergence of urban high-rise building, the vertical space of human daily life gradually extended upward. Seasonal characteristics of vertical distribution of dust loadings and heavy metals near surface are remarkable. In this study, we collected dust deposited on the windowsill at different space height (1th-8th floor) from three buildings in Guiyang city during spring, summer, autumn and winter, and analyzed the deposition fluxes of dust and elements including Ca, Fe, Cd, Cr, Cu, Ni, Pb and Zn. The results showed that: the total changing trend of vertical distribution of dust loadings was that the deposition fluxes of dust in winter were the highest, followed by those in spring, and the deposition fluxes of dust in summer were the lowest. The degree of variation on dust loadings dependent on the change of elevation was the highest in winter, followed by that in summer, and was relatively lower in spring and autumn. The effect on dust loadings by seasonal changing was relatively heavier on windowsill on the lower level than on the higher level. The levels of elements were the highest in spring dust, while those in autumn were relatively lower. Among the 8 elements, the variability of Zn in dust related to space time variation was the most obvious, and that of Ca was weaker. The atmospheric inversion condition might be one of the reasons that improved the deposition fluxes of dust and the contents of Ph and Zn in dust during winter and spring.

  15. [Seasonal Provincial Characteristics of Vertical Distribution of Dust Loadings and Heavy Metals near Surface in City].

    PubMed

    Li, Xiao-yan; Zhang, Shu-ting

    2015-06-01

    With the emergence of urban high-rise building, the vertical space of human daily life gradually extended upward. Seasonal characteristics of vertical distribution of dust loadings and heavy metals near surface are remarkable. In this study, we collected dust deposited on the windowsill at different space height (1th-8th floor) from three buildings in Guiyang city during spring, summer, autumn and winter, and analyzed the deposition fluxes of dust and elements including Ca, Fe, Cd, Cr, Cu, Ni, Pb and Zn. The results showed that: the total changing trend of vertical distribution of dust loadings was that the deposition fluxes of dust in winter were the highest, followed by those in spring, and the deposition fluxes of dust in summer were the lowest. The degree of variation on dust loadings dependent on the change of elevation was the highest in winter, followed by that in summer, and was relatively lower in spring and autumn. The effect on dust loadings by seasonal changing was relatively heavier on windowsill on the lower level than on the higher level. The levels of elements were the highest in spring dust, while those in autumn were relatively lower. Among the 8 elements, the variability of Zn in dust related to space time variation was the most obvious, and that of Ca was weaker. The atmospheric inversion condition might be one of the reasons that improved the deposition fluxes of dust and the contents of Ph and Zn in dust during winter and spring. PMID:26387336

  16. Anxiety disorders in late life.

    PubMed Central

    Flint, A. J.

    1999-01-01

    OBJECTIVE: To review the epidemiology, clinical characteristics, and treatment of anxiety disorders in late life. QUALITY OF EVIDENCE: Epidemiologic and comorbidity data are derived from well designed random-sample community surveys. There are virtually no controlled data specific to treatment of anxiety in the elderly. Guidelines for treating anxiety disorders in late life, therefore, must be extrapolated from results of randomized controlled trials conducted in younger patients. MAIN MESSAGE: Generalized anxiety disorder and agoraphobia account for most cases of anxiety disorder in late life. Late-onset generalized anxiety is usually associated with depressive illness and, in this situation, the primary pharmacologic treatment is antidepressant medication. Most elderly people with agoraphobia do not give a history of panic attacks; exposure therapy is the preferred treatment for agoraphobia without panic. CONCLUSIONS: Physicians need to make more use of antidepressant medication and behavioural therapy and less use of benzodiazepines in treating anxiety disorders in late life. PMID:10587775

  17. First Outcomes from the National Summer Learning Study. Brief

    ERIC Educational Resources Information Center

    McCombs, Jennifer Sloan; Pane, John F.; Augustine, Catherine H.; Schwartz, Heather L.; Martorell, Paco; Zakaras, Laura

    2014-01-01

    Many students lose knowledge and skills over the long summer break, and research suggests that low-income students fall further behind over the summer than their higher-income peers. Voluntary summer learning programs may provide an opportunity to stem summer learning loss and give struggling students additional learning opportunities. The Wallace…

  18. Education in Summer: 100 Years at UW-Madison.

    ERIC Educational Resources Information Center

    Wisconsin Univ., Madison.

    College summer sessions, and specifically the summer program at the University of Wisconsin-Madison between 1885-1985 are discussed in two papers and a conference summary. In "History of Summer School at the University of Wisconsin," John W. Jenkins and Barry J. Teicher examine the emergence and nature of summer programs in the context of the…

  19. Winter and Summer Views of the Salt Lake Region

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Magnificent views of the region surrounding Salt Lake City, Utah are captured in these winter and summer images from the Multi-angle Imaging SpectroRadiometer's vertical-viewing (nadir) camera. Salt Lake City, situated near the southeastern shore of the Great Salt Lake, is host to the 2002 Winter Olympic Games, which open Friday, February 8. Venues for five of the scheduled events are at city (indoor) locations, and five in mountain (outdoor) facilities. All ten can be found within the area contained in these images. Some of the outdoor events take place at Ogden, situated north of Salt Lake City and at Park City, located to the east. Salt Lake City is surrounded by mountains including the Wasatch Range to the east, and the temperature difference between the Great Salt Lake and the overlying atmosphere enhances the moisture content of winter storms. These factors, in combination with natural cloud seeding by salt crystals from the lake, are believed to result in greater snowfall in neighboring areas compared to more distant locales. In addition to the obvious difference in snow cover between the winter and summer views, water color changes in parts of the Great Salt Lake are apparent in these images. The distinctly different coloration between the northern and southern arms of the Great Salt Lake is the result of a rock-filled causeway built in 1953 to support a permanent railroad. The causeway has resulted in decreased circulation between the two arms and higher salinity on the northern side. The southern part of the lake includes the large Antelope Island, and at full resolution a bridge connecting it to the mainland can be discerned. These images are natural color views acquired on February 8, 2001 and June 16, 2001, respectively. Each image represents an area of about 220 kilometers x 285 kilometers. Image courtesy NASA/GSFC/LaRC/JPL, MISR Team.

  20. Asian summer monsoon onset barrier and its formation mechanism

    NASA Astrophysics Data System (ADS)

    Liu, Boqi; Liu, Yimin; Wu, Guoxiong; Yan, Jinghui; He, Jinhai; Ren, Suling

    2015-08-01

    The onset process of Asian summer monsoon (ASM) is investigated based on diagnostic analysis of observations of precipitation and synoptic circulation. Results show that after the ASM commences over the eastern Bay of Bengal (BOB) around early May, the onset can propagate eastwards towards the South China Sea and western Pacific but is blocked on its westward propagation along the eastern coast of India. This blocking, termed the "monsoon onset barrier (MOB)", presents a Gill-type circulation response to the latent heating released by BOB monsoon convection. This convective condensation heating generates summertime (wintertime) vertical easterly (westerly) shear to its east (west) and facilitates air ascent (descent). The convection then propagates eastward but gets trapped on its westward path. To the east of the central BOB, the surface air temperature (SAT) cools faster than the underlying sea surface temperature (SST) due to monsoon onset. Thus more sensible heat flux supports the onset convection to propagate eastward. To the west of the central BOB, however, the land surface sensible heating over the Indian Peninsula is strengthened by the enhanced anticyclone circulation and air descent induced by the BOB monsoon heating. The strengthened upstream warm horizontal advection then produces a warm SAT center over the MOB region, which together with the in situ cooled SST reduces the surface sensible heating and atmospheric available potential energy to prevent the occurrence of free convection. Therefore, it is the change in both large-scale circulation and air-sea interaction due to BOB summer monsoon onset that contributes to the MOB formation.

  1. Lynch Ferry Hatchery - Summer Steelhead, Final Report

    SciTech Connect

    Watson, M.

    1996-05-01

    This report presents the findings of the independent audit of the Lyons Ferry Hatchery (Summer Steelhead). Lyons Ferry Hatchery is located downstream of the confluence of the Palouse and Snake rivers, about 7 miles west of Starbuck, Washington. The hatchery is used for adult collection of fall chinook and summer steelhead, egg incubation of fall chinook, spring chinook, steelhead, and rainbow trout and rearing of fall chinook, spring chinook, summer steelhead, and rainbow trout. The audit was conducted in April 1996 as part of a two-year effort that will include 67 hatcheries and satellite facilities located on the Columbia and Snake River system in Idaho, Oregon, and Washington. The hatchery operating agencies include the US Fish and Wildlife Service, Idaho Department of Fish and Game, Oregon Department of Fish and Wildlife, and Washington Department of Fish and Wildlife.

  2. Summer Research Experiences with a Laboratory Tokamak

    NASA Astrophysics Data System (ADS)

    Farley, N.; Mauel, M.; Navratil, G.; Cates, C.; Maurer, D.; Mukherjee, S.; Shilov, M.; Taylor, E.

    1998-11-01

    Columbia University's Summer Research Program for Secondary School Science Teachers seeks to improve middle and high school student understanding of science. The Program enhances science teachers' understanding of the practice of science by having them participate for two consecutive summers as members of laboratory research teams led by Columbia University faculty. In this poster, we report the research and educational activities of two summer internships with the HBT-EP research tokamak. Research activities have included (1) computer data acquisition and the representation of complex plasma wave phenomena as audible sounds, and (2) the design and construction of pulsed microwave systems to experience the design and testing of special-purpose equipment in order to achieve a specific technical goal. We also present an overview of the positive impact this type of plasma research involvement has had on high school science teaching.

  3. Summer Research Internships at Biosphere 2 Center

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Through the support of NASA's Mission to Planet Earth, Biosphere 2 Center hosted 10 research interns for a 10 week period during the summer of 1998. In addition, we were able to offer scholarships to 10 students for Columbia University summer field courses. Students participating in these programs were involved in numerous earth systems activities, collecting data in the field and conducting analyses in the laboratory. Students enrolled in the field program were expected to design independent research projects as part of their coursework. In addition to laboratory and field research, students participated in weekly research seminars by resident and visiting scientists. Field school students were involved in field trips exposing them to the geology and ecology of the region including Arizona Sonora Desert Museum, Mount Lemmon, Aravaipa Canyon and the Gulf of California. Interns participated in laboratory-based research. All students were expected to complete oral and written presentations of their work during the summer.

  4. [Vertical fractures: apropos of 2 clinical cases].

    PubMed

    Félix Mañes Ferrer, J; Micò Muñoz, P; Sánchez Cortés, J L; Paricio Martín, J J; Miñana Laliga, R

    1991-01-01

    The aim of the study is to present a clinical review of the vertical root fractures. Two clinical cases are presented to demonstrates the criteria for obtaining a correct diagnosis of vertical root fractures.

  5. Vertical separation of the two beams

    SciTech Connect

    Heifets, S.

    1985-10-01

    The author discusses the problem of design of insertion points on the SSC, and in particular keeping the length necessary for them under control. Here he considers the possibility of having vertically separated beams, without a vertical dispersion suppressor.

  6. Vertical Feature Mask Feature Classification Flag Extraction

    Atmospheric Science Data Center

    2013-03-28

      Vertical Feature Mask Feature Classification Flag Extraction This routine demonstrates extraction of the ... in a CALIPSO Lidar Level 2 Vertical Feature Mask feature classification flag value. It is written in Interactive Data Language (IDL) ...

  7. [Vertical fractures: apropos of 2 clinical cases].

    PubMed

    Félix Mañes Ferrer, J; Micò Muñoz, P; Sánchez Cortés, J L; Paricio Martín, J J; Miñana Laliga, R

    1991-01-01

    The aim of the study is to present a clinical review of the vertical root fractures. Two clinical cases are presented to demonstrates the criteria for obtaining a correct diagnosis of vertical root fractures. PMID:1659859

  8. The 1981 Summer Research Fellowship Program

    NASA Technical Reports Server (NTRS)

    Spencer, J. H. (Compiler)

    1981-01-01

    The NASA-Hampton Institute Summer Research Fellowship Program, offering capable scientists and engineers at traditionally black institutions an opportunity to participate in research activities in an environment at the Langley Research Center where basic research is of primary importance is considered. The Summer Research Fellowship Program, specifically designed to assist these faculty members in identifying areas of research which correlate positively with their individual interest and capabilities is discussed. It is also designed to help them to initiate viable research which increases their technical knowledge about how research efforts at their institutions might be increased.

  9. Vertical Profile of Aerosol Properties at Pico Mountain, Azores

    NASA Astrophysics Data System (ADS)

    Wright, K.; Mazzoleni, C.; Mazzoleni, L. R.; Dzepina, K.; Hueber, J.; China, S.; Sharma, N.

    2013-12-01

    Pico Mountain (2325m asl) is a dormant volcano in the archipelago of the Azores1500 km west of Lisbon, Portugal in the North Atlantic. It differs from typical mountain ranges such as the Alps or the Rockies, which are large and present a complex orography. Pico Mountain has a simple cone-like structure with only one main peak and is thousands of kilometers away from any other significant mountain range. In summer months, it is typical for air masses to move around the mountain rather than traveling up its face. This implies that often the peak of the mountain lies above the marine boundary layer in the free troposphere, while the lower part of the mountain is affected by marine clouds and marine air-masses. An atmospheric monitoring station, the Pico Mountain Observatory was established in 2001 in the summit caldera of the volcano at 2225m above sea level. The observatory is far from large populations or pollution sources, which makes the station ideal to study atmospheric gases and aerosols transported over long-ranges in the free troposphere. The station is reachable only by foot following a steep and strenuous hiking trail. In the summer of 2013 we began to collect vertical profiles of aerosol by carrying an instrumented backpack up to the summit of the mountain, with the goal of studying the vertical structure of atmospheric aerosols from the marine boundary layer to the free troposphere. The backpack was carried from the base of trail at 1200m asl. The backpack was equipped with the following instruments: 1. Nephelometer to measure light scattering from aerosol 2. 2-size optical particle counter (300-500 nm) 3. Portable micro-aethalometer to measure absorbing aerosols 4. SEM/TEM sampler to collect particles for off-line electron microscopy analysis 5. Battery powered data logger to measure relative humidity, temperature and pressure 6. GPS tracking device We provide a preliminary analysis of data collected in 2013 to gain insight on the vertical distribution

  10. Late Pleistocene vegetation of Kings Canyon, Sierra Nevada, California

    NASA Astrophysics Data System (ADS)

    Cole, Kenneth

    1983-01-01

    Seven packrat midden samples make possible a comparison between the modern and late Pleistocene vegetation in Kings Canyon on the western side of the southern Sierra Nevada. One modern sample contains macrofossils and pollen derived from the present-day oak-chaparral vegetation. Macrofossils from the six late Pleistocene samples record a mixed coniferous forest dominated by the xerophytic conifers Juniperus occidentalis, Pinus cf. ponderosa, and P. monophylla. The pollen spectra of these Pleistocene middens are dominated by Pinus sp., Taxodiaceae-Cupressaceae-Taxaceae (TCT), and Artemisia sp. Mesophytic conifers are represented by low macrofossil concentrations. Sequoiadendron giganteum is represented by a few pollen grains in the full glacial. Edaphic control and snow dispersal are the most likely causes of these mixed assemblages. The dominant macrofossils record a more xeric plant community than those that now occur on similar substrates at higher elevations or latitudes in the Sierra Nevada. These assemblages suggest that late Wisconsin climates were cold with mean annual precipitation not necessarily greater than modern values. This conclusion supports a model of low summer ablation allowing for the persistence of the glaciers at higher elevations during the late Wisconsin. The records in these middens also suggest that S. giganteum grew at lower elevations along the western side of the range and that P. monophylla was more widely distributed in cismontane California during the Pleistocene.

  11. [Sociological aspects of late fatherhood].

    PubMed

    Bessin, M

    2006-09-01

    Starting from a sociological research on late parenthood, the article shows quantitative and qualitative lessons on the subject--in particular concerning the fathers' perspective. Late parenthood has declined over the 20th Century, to increase again since 1980. The further exploitation of the survey EHF 99 shows the processes and the socio-demographic of late fatherhood, over three generations. This phenomenon is tightly related to the multiple descents and family recombinings. We also observe in these configurations major age differences between spouses and late relationship. The social bipolarity of this phenomenon appears clearly as far as late motherhood is concerned, but is less clear concerning fatherhood, since more blue collars and non qualified men are concerned. This difference is due to the important role played by migrants in this phenomenon. A qualitative survey conducted on the basis of biographic interviews has underlined the gendered logics of late family founding. These logics are linked to the discrepancies due to man/woman differences regarding their respective calendar of fertility and to their attitude towards work. The interviews which provide an analysis of the biographical processes of late parenthood are organised according to postponement or renewal logics, in the form of refoundation or repetition. They are linked to self-introspection and to the negotiations at work within a couple.

  12. Vertically aligned nanostructure scanning probe microscope tips

    DOEpatents

    Guillorn, Michael A.; Ilic, Bojan; Melechko, Anatoli V.; Merkulov, Vladimir I.; Lowndes, Douglas H.; Simpson, Michael L.

    2006-12-19

    Methods and apparatus are described for cantilever structures that include a vertically aligned nanostructure, especially vertically aligned carbon nanofiber scanning probe microscope tips. An apparatus includes a cantilever structure including a substrate including a cantilever body, that optionally includes a doped layer, and a vertically aligned nanostructure coupled to the cantilever body.

  13. A design for vertical crossing insertions

    SciTech Connect

    Garren, A.

    1985-10-01

    A crossing insertion designed for an SSC with vertically separated 1-in-1 beam lines is presented in this note. The author supposes that the beam lines consist of separate magnets in separate cryostats separated by about 70 cm. He then describes the design, where vertical separation is done with four vertical dipoles producing a steplike beam line.

  14. 46 CFR 108.160 - Vertical ladders.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Vertical ladders. 108.160 Section 108.160 Shipping COAST... Construction and Arrangement Means of Escape § 108.160 Vertical ladders. (a) Each vertical ladder must have... inches) apart, uniform for the length of the ladder; and (3) At least 18 centimeters (7 inches) from...

  15. 46 CFR 108.160 - Vertical ladders.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Vertical ladders. 108.160 Section 108.160 Shipping COAST... Construction and Arrangement Means of Escape § 108.160 Vertical ladders. (a) Each vertical ladder must have... inches) apart, uniform for the length of the ladder; and (3) At least 18 centimeters (7 inches) from...

  16. Vertical Lift - Not Just For Terrestrial Flight

    NASA Technical Reports Server (NTRS)

    Young, Larry A

    2000-01-01

    Autonomous vertical lift vehicles hold considerable potential for supporting planetary science and exploration missions. This paper discusses several technical aspects of vertical lift planetary aerial vehicles in general, and specifically addresses technical challenges and work to date examining notional vertical lift vehicles for Mars, Titan, and Venus exploration.

  17. Dynamic aspects of the Southern-Hemisphere medium-scale waves during the southern summer season

    NASA Technical Reports Server (NTRS)

    Chen, Tsing-Chang; Yen, Ming-Cheng; Nune, Durga P.

    1987-01-01

    The role of medium-scale waves on three dynamic aspects of the Southern-Hemisphere general circulation is examined using data generated by the FGGE analyses of the ECMWF. The momentum and sensible heat transports by the medium-scale waves are discussed. The effects of medium-scale waves on atmospheric circulation of the Southern Hemisphere during the summer, in particular the vacillation of atmospheric energetics, are investigated. The horizontal and vertical structures and the transport properties of this wave regime and their relation to downstream development in the Southern Hemisphere are analyzed. It is observed that medium-scale waves supply about a half of the total eddy transport of sensible heat and momentum; the wave regime contributes to the time average of various energy contents and energetic components of atmospheric motion during the southern summer; and the wave regime is amplified during the developing stages of downstream development.

  18. Mountain-climbing bears protect cherry species from global warming through vertical seed dispersal.

    PubMed

    Naoe, Shoji; Tayasu, Ichiro; Sakai, Yoichiro; Masaki, Takashi; Kobayashi, Kazuki; Nakajima, Akiko; Sato, Yoshikazu; Yamazaki, Koji; Kiyokawa, Hiroki; Koike, Shinsuke

    2016-04-25

    In a warming climate, temperature-sensitive plants must move toward colder areas, that is, higher latitude or altitude, by seed dispersal [1]. Considering that the temperature drop with increasing altitude (-0.65°C per 100 m altitude) is one hundred to a thousand times larger than that of the equivalent latitudinal distance [2], vertical seed dispersal is probably a key process for plant escape from warming temperatures. In fact, plant geographical distributions are tracking global warming altitudinally rather than latitudinally, and the extent of tracking is considered to be large in plants with better-dispersed traits (e.g., lighter seeds in wind-dispersed plants) [1]. However, no study has evaluated vertical seed dispersal itself due to technical difficulty or high cost. Here, we show using a stable oxygen isotope that black bears disperse seeds of wild cherry over several hundred meters vertically, and that the dispersal direction is heavily biased towards the mountain tops. Mountain climbing by bears following spring-to-summer plant phenology is likely the cause of this biased seed dispersal. These results suggest that spring- and summer-fruiting plants dispersed by animals may have high potential to escape global warming. Our results also indicate that the direction of vertical seed dispersal can be unexpectedly biased, and highlight the importance of considering seed dispersal direction to understand plant responses to past and future climate change.

  19. Mountain-climbing bears protect cherry species from global warming through vertical seed dispersal.

    PubMed

    Naoe, Shoji; Tayasu, Ichiro; Sakai, Yoichiro; Masaki, Takashi; Kobayashi, Kazuki; Nakajima, Akiko; Sato, Yoshikazu; Yamazaki, Koji; Kiyokawa, Hiroki; Koike, Shinsuke

    2016-04-25

    In a warming climate, temperature-sensitive plants must move toward colder areas, that is, higher latitude or altitude, by seed dispersal [1]. Considering that the temperature drop with increasing altitude (-0.65°C per 100 m altitude) is one hundred to a thousand times larger than that of the equivalent latitudinal distance [2], vertical seed dispersal is probably a key process for plant escape from warming temperatures. In fact, plant geographical distributions are tracking global warming altitudinally rather than latitudinally, and the extent of tracking is considered to be large in plants with better-dispersed traits (e.g., lighter seeds in wind-dispersed plants) [1]. However, no study has evaluated vertical seed dispersal itself due to technical difficulty or high cost. Here, we show using a stable oxygen isotope that black bears disperse seeds of wild cherry over several hundred meters vertically, and that the dispersal direction is heavily biased towards the mountain tops. Mountain climbing by bears following spring-to-summer plant phenology is likely the cause of this biased seed dispersal. These results suggest that spring- and summer-fruiting plants dispersed by animals may have high potential to escape global warming. Our results also indicate that the direction of vertical seed dispersal can be unexpectedly biased, and highlight the importance of considering seed dispersal direction to understand plant responses to past and future climate change. PMID:27115684

  20. Covariability of western tropical Pacific-North Pacific atmospheric circulation during summer

    PubMed Central

    Yun, Kyung-Sook; Yeh, Sang-Wook; Ha, Kyung-Ja

    2015-01-01

    North Pacific subtropical high (NPSH) is permanent high-pressure system over the Northern Pacific Ocean and it extends to the western North Pacific during the boreal summer (June-July-August), which is so called the western North Pacific subtropical high (WNPSH). Here, we examine the covariability of the NPSH-WNPSH during summer using both observation and Coupled Model Intercomparison Project phase 5 (CMIP5) model data. The statistical analyses indicate that the NPSH-WNPSH covariability shows significant decadal variability in the observations, in addition, the in-phase relationship of NPSH-WNPSH is enhanced after the mid-to-late 1990s. A dipole-like sea surface temperature (SST) pattern, i.e., a warming in the western Pacific and a cooling in the eastern Pacific, is dominant after the mid-to-late 1990s, which acts to enhance the covariability of NPSH-WNPSH by modulating the atmospheric teleconnections. However, the covariability of NPSH-WNPSH in the future climate is not much influenced by the anthropogenic forcing but it is largely characterized by the natural decadal-to-interdecadal variability, implying that the enhancement of NPSH-WNPSH covariability after the mid-to-late 1990s could be considered as part of decadal-to-interdecadal variability. PMID:26594044

  1. ?Vertical Sextants give Good Sights?

    NASA Astrophysics Data System (ADS)

    Richey, Michael

    Mark Dixon suggests (Forum, Vol. 50, 137) that nobody thus far has attempted to quantify the errors from tilt that arise while observing with the marine sextant. The issue in fact, with the related problem of what exactly is the axis about which the sextant is rotated whilst being (to define the vertical), was the subject of a lively controversy in the first two volumes of this Journal some fifty years ago. Since the consensus of opinion seems to have been that the maximum error does not necessarily occur at 45 degrees, whereas Dixon's table suggests that it does, some reiteration of the arguments may be in order.

  2. Vertical jumping and signaled avoidance

    PubMed Central

    Cándido, Antonio; Maldonado, Antonio; Vila, Jaime

    1988-01-01

    This paper reports an experiment intended to demonstrate that the vertical jumping response can be learned using a signaled-avoidance technique. A photoelectric cell system was used to record the response. Twenty female rats, divided equally into two groups, were exposed to intertrial intervals of either 15 or 40 s. Subjects had to achieve three successive criteria of acquisition: 3, 5, and 10 consecutive avoidance responses. Results showed that both groups learned the avoidance response, requiring increasingly larger numbers of trials as the acquisition criteria increased. No significant effect of intertrial interval was observed. PMID:16812559

  3. Neighbourly polytopes with few vertices

    SciTech Connect

    Devyatov, Rostislav A

    2011-10-31

    A family of neighbourly polytopes in R{sup 2d} with N=2d+4 vertices is constructed. All polytopes in the family have a planar Gale diagram of a special type, namely, with exactly d+3 black points in convex position. These Gale diagrams are parametrized by 3-trees (trees with a certain additional structure). For all polytopes in the family, the number of faces of dimension m containing a given vertex A depends only on d and m. Bibliography: 7 titles.

  4. South Asian Summer Monsoon Dynamics In A High-Resolution Nested Climate Model

    NASA Astrophysics Data System (ADS)

    Ashfaq, M.; Ying, S.; Tung, W.; Trapp, R. J.; Gao, X.; Pal, J. S.; Diffenbuagh, N. S.

    2007-12-01

    We present results from a high-resolution climate simulation of the south Asian monsoon using the Abdus Salam Centre for Theoretical Physics Regional Climate Model (RegCM3). The RegCM3 experiment consists of a 30-year integration from 1961 to 1990 performed at a 25 km grid spacing. Atmospheric boundary conditions for the integration are provided by the National Aeronautics and Space Administration (NASA) Finite Volume General Circulation Model (FVGCM). The ability of RegCM3 to simulate the dynamics of the summer monsoon is tested by comparing a number of fields with observations, including upper and lower level circulation patterns, seasonal mean precipitation and temperature, and variations in tropospheric temperature gradient and easterly vertical shear. Our results show that RegCM3 is able to simulate the dynamical features of the South Asian summer monsoon reasonably well. For instance, the seasonal reversal of tropospheric temperature gradient and strengthening of easterly vertical shear compare well with observations. Furthermore, summer monsoon onset dates over land match reasonably well with the long-term onset-climatology, and the interannual variations in the anomalies of the local Hadley circulation and summer monsoon precipitation are strongly correlated. The primary discrepancies occur over areas of high seasonal precipitation - such as the west coasts of India and Myanmar - where RegCM3 values exceed those found in the observations. Similarly, RegCM3 overestimates precipitation values on the lee side of the Western Ghats. Compared to the driving FVGCM simulation, the RegCM3 simulation shows significant improvement in spatial pattern of seasonal precipitation.

  5. 1970 External Summer Youth Opportunity Campaign.

    ERIC Educational Resources Information Center

    Federal Highway Administration (DOT), Washington, DC.

    The Federal Highway Administration exceeded its goal of 50,000 jobs in its 1970 External Summer Youth Opportunity Campaign by providing 57,646 jobs. Of the jobs available, a large majority were filled by disadvantaged youth. Various Federal and private agencies were involved in making the program work. This pamphlet describes the national youth…

  6. A Summer Course in Field Ecology

    ERIC Educational Resources Information Center

    Perkins, John F.

    1973-01-01

    Describes a high school summer program in field ecology designed to give students a first-hand understanding of their own biotic environment, to acquaint them with the organisms, relationships, and complexities of local habitats, and to introduce them to the methods and techniques of discovering and gathering information about nature. (JR)

  7. Key Actions of Successful Summer Research Mentors

    ERIC Educational Resources Information Center

    Raman, D. Raj; Geisinger, Brandi N.; Kemis, Mari R.; de la Mora, Arlene

    2016-01-01

    Summer research opportunities for undergraduates, such as those supported by the National Science Foundation's Research Experience for Undergraduates (REU) program, can be critical experiences that help persuade students to pursue research through graduate studies. Studies analyzing the key actions of successful mentors are scarce. The goal of…

  8. Mississippi Magic: Summer Library Program, 1999.

    ERIC Educational Resources Information Center

    Hudspeth, Jean; Shurden, Lynn Fletcher

    This manual for the 1999 Mississippi summer library program for preschool through elementary age children contains the following sections: (1) Introduction, including planning, promotional activities, sample radio spots and press releases, sample letters to parents, tips for including children with disabilities, a general bibliography, a…

  9. Changes in European summer temperature variability revisited

    NASA Astrophysics Data System (ADS)

    Fischer, E. M.; Rajczak, J.; Schär, C.

    2012-10-01

    Summer temperature variability has been projected to increase in Central Europe in response to anthropogenic greenhouse gas forcing. Based on an unprecedented set of global and regional climate models from the ENSEMBLES project, we assess the robustness of these projections on interannual to daily time scales. In comparison to previous analyses using PRUDENCE simulations, we find a more diverse climate change signal for interannual summer temperature variability and a clear dependence upon present-day model performance. Models that realistically represent present-day variability, tend to consistently project increasing interannual variability at the end of the 21st century. We demonstrate that the partitioning of latent and sensible heat fluxes controlled by soil moisture is crucial to understand the projected changes across the multi-model experiment. The projected increase in daily summer temperature variability is more robust and consistently simulated by all models. Likewise, all models consistently project reduced daily temperature variability in winter. Thus, it is a robust signal across the entire ensemble that in summer and south-central Europe hot extremes warm stronger than the mean, and in winter and northern Europe cold extremes warm stronger than mean temperatures.

  10. Changes in European summer temperature variability revisited

    NASA Astrophysics Data System (ADS)

    Schar, C.; Fischer, E. M.; Rajcak, J.

    2012-12-01

    Summer temperature variability has been projected to increase in Central Europe in response to anthropogenic greenhouse gas forcing. Based on an unprecedented set of global and regional climate models from the ENSEMBLES project, we assess the robustness of these projections on interannual to daily time scales. In comparison to previous analyses using PRUDENCE simulations, we find a more diverse climate change signal for interannual summer temperature variability and a clear dependence upon present-day model performance. Models that realistically represent present-day variability tend to consistently project increasing interannual variability at the end of the 21st century. We demonstrate that the partitioning of latent and sensible heat fluxes controlled by soil moisture is crucial to understand the projected changes across the multi-model experiment. The projected increase in daily summer temperature variability is more robust and consistently simulated by all models. Likewise, all models consistently project reduced daily temperature variability in winter. Thus, it is a robust signal across the entire ensemble that in summer and south-central Europe hot extremes warm stronger than the mean, and in winter and northern Europe cold extremes warm stronger than mean temperatures.

  11. Physics Meets Biology (LBNL Summer Lecture Series)

    ScienceCinema

    Chu, Steve [Director, LBNL

    2016-07-12

    Summer Lecture Series 2006: If scientists could take advantage of the awesomely complex and beautiful functioning of biologys natural molecular machines, their potential for application in many disciplines would be incalculable. Nobel Laureate and Director of the Lawrence Berkeley National Laboratory Steve Chu explores Possible solutions to global warming and its consequences.

  12. Summer Bridge's Effects on College Student Success

    ERIC Educational Resources Information Center

    Bir, Beth; Myrick, Mondrail

    2015-01-01

    This study considered whether participation in a rigorous, intense summer bridge program had a significant effect on the academic success of African-American male and female students in developmental education, compared to nonparticipants, at a four-year Historically Black University in terms of retention, progression, and graduation from…

  13. Urban STEM Education: A Unique Summer Experience

    ERIC Educational Resources Information Center

    White, David W.

    2013-01-01

    In April of 2010, the author was approached to write a proposal that would provide grant money for a summer program to take place at the Florida Agricultural and Mechanical University's Developmental Research School (FAMU DRS). The FAMU DRS functions as a normal K-12 school; however, it is administered by the Florida A&M University College of…

  14. National Migrant Education Summer School Directory: 1997.

    ERIC Educational Resources Information Center

    State Univ. of New York, Oneonta. Coll. at Oneonta. Eastern Stream Center on Resources and Training.

    This state-by-state directory of migrant education summer programs is intended to help educators coordinate services and instruction for migrant families and their children. All states (except Hawaii), Puerto Rico, and the District of Columbia are listed. Each state entry includes the complete mailing address, telephone and fax numbers, and e-mail…

  15. Summer Principals'/Directors' Orientation Training Module.

    ERIC Educational Resources Information Center

    Mata, Robert L.; Garcia, Richard L.

    Intended to provide current or potential project principals/directors with the basic knowledge, skills, abilities, and sensitivities needed to manage a summer migrant school project in the local educational setting, this module provides instruction in the project management areas of planning, preparation, control, and termination. The module…

  16. A Metacognitive Pedagogy: The River Summer Project

    ERIC Educational Resources Information Center

    Son, Lisa K.; Kenna, Timothy; Pfirman, Stephanie

    2007-01-01

    This article describes River Summer, an interdisciplinary, field project on the Hudson River. Using cognitive data, the team aimed to design an experience that fostered an environment implementing strategies that improve learning. The participants, 40 faculty members from 24 institutions who acted as teachers, students, or both, boarded the…

  17. 1984 Summer Scholars Participants. A Follow Up.

    ERIC Educational Resources Information Center

    Mares, Kenneth R.; And Others

    A followup study was conducted to assess the impact of two 1984 Summer Scholars Programs at the University of Missouri, Kansas City, School of Medicine, which sponsors a combined bachelor's degree and doctor of medicine (M.D.) program. The university, in cooperation with area hospitals, implemented a 4-week program to identify and motivate…

  18. Current Research: 2013 Summer Reading Suggestions

    ERIC Educational Resources Information Center

    Journal of College Science Teaching, 2013

    2013-01-01

    To supplement the summer reading of National Science Teachers Association (NSTA) members, the NSTA Committee on Research in Science Education suggested a list of science education research articles that were published in the journals of NSTA's affiliates in 2012. These articles covered a variety of topics that include learning about…

  19. What Is Summer Vacation Costing Us?

    ERIC Educational Resources Information Center

    Henkel, Tara

    2010-01-01

    This paper explores the standard traditional summer vacation model; this includes the accompanying food insecurity, loss of nutrition and the lost knowledge that must be re-taught at the beginning of each new academic year. It compares the number of academic days attended in various Industrialized Nations compared to the United States. Also,…

  20. Utilization of summer legumes as bioenergy feedstocks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sunn hemp (Crotolaria juncea), is a fast growing, high biomass yielding tropical legume that may be a possible southeastern bioenergy crop. When comparing this legume to a commonly grown summer legume—cowpeas (Vigna unguiculata), sunn hemp was superior in biomass yield and subsequent energy yield. S...

  1. Summer Programs Offer Great Ideas for Teachers

    ERIC Educational Resources Information Center

    Pantin, Travis

    2007-01-01

    Every summer, with financial support from the National Endowment for the Humanities (NEH), more than 2,500 teachers from across the U.S. participate in advanced study programs in the humanities that range from one to six weeks in length. Most of the programs are conducted at institutions of higher learning, both within the U.S. and abroad, and…

  2. Remembering Jack: A Hampshire County Summer.

    ERIC Educational Resources Information Center

    Olson, Ted

    1993-01-01

    A former counselor at a summer camp in Hampshire County (West Virginia) recalls his experiences with his campers and Jack Schaffenaker, an Appalachian "mountain man" and guitar picker. Through Jack, the campers engaged in fishing, storytelling, hiking, and folk singing, and shed some negative stereotypes about Appalachian people. (KS)

  3. A Summer Undergraduate Psychology Internship in Scotland.

    ERIC Educational Resources Information Center

    Fernald, C. D.

    2001-01-01

    Presents a program that combines a summer psychology internship with study abroad experiences. Discusses the development of the course, including its history and funding, and the selection of student participants. Describes the orientations, the internship activities, the social activities, and the Enrichment Seminar, which is required for Honors…

  4. NASA/ASEE Summer Faculty Fellowship Program

    NASA Technical Reports Server (NTRS)

    Hosler, E. Ramon (Editor); Armstrong, Dennis W. (Editor)

    1989-01-01

    The contractor's report contains all sixteen final reports prepared by the participants in the 1989 Summer Faculty Fellowship Program. Reports describe research projects on a number of different topics. Interface software, metal corrosion, rocket triggering lightning, automatic drawing, 60-Hertz power, carotid-cardiac baroreflex, acoustic fields, robotics, AI, CAD/CAE, cryogenics, titanium, and flow measurement are discussed.

  5. Report on Fulbright Summer Seminar on Indonesia.

    ERIC Educational Resources Information Center

    Christenson, Charles Elroy

    This resource packet was compiled by a participant in the Fulbright Summer Seminar on Indonesia. The materials provide information for teaching about the diaspora of Hinduism and Islamic beliefs throughout the southeast Asia archipelagoes and their influence on art and culture. The handouts supplement information on Indonesia as part of an Asian…

  6. Facilitator's Manual: Summer Transitions. Fifth Edition.

    ERIC Educational Resources Information Center

    Kuenzli, Linda A., Ed.

    A facilitator's manual for the Summer Transition Enrichment Program at Bowling Green State University is presented. The overall objectives of the program are: (1) to facilitate the transition of entering freshmen into the academic and cultural life of the university; and (2) to assist students in their personal growth and adjustment to the…

  7. Chinese Summer Schools Sell Quick Credits

    ERIC Educational Resources Information Center

    McMurtrie, Beth; Farrar, Lara

    2013-01-01

    American-style summer programs in China, catering to Chinese-born students, have taken American universities by surprise. They are yet one more player in the complex and often opaque Chinese education industry, an industry in which American colleges are finding themselves increasingly entwined. These programs have become a booming enterprise,…

  8. 1994 Summer Youth Employment Training Program Overview.

    ERIC Educational Resources Information Center

    Minnesota State Dept. of Economic Security, St. Paul.

    This report describes summer youth employment and training programs operated throughout Minnesota via the Service Delivery Area/Private Industry Council network. It provides a statistical profile of the young people served, program costs, and program outcomes. The report begins with statewide outcome information, including a statewide summary of…

  9. Facilitating a Summer Reading Book Group Program

    ERIC Educational Resources Information Center

    Malin, Ginger Goldman

    2007-01-01

    Summer book groups enhance and sustain student literacy behaviors over the break, making available an enjoyable social forum for critical-thinking and critical-reading practices to occur naturally. Significantly, the book groups grant faculty and students an informal space to connect meaningfully through reflective discussion of texts. Because…

  10. The Martian North Polar Summer Water Cycle

    NASA Astrophysics Data System (ADS)

    Brown, A. J.; Calvin, W. M.; Becerra, P.; Byrne, S.

    2016-09-01

    We report on the summer water cycle of the north polar cap and identify regions and times across the cap when the cap is in 'net deposition' and 'net sublimation' modes. This may help us to determine regions of the cap that are currently stable.

  11. Tri-District Arts Consortium Summer Program.

    ERIC Educational Resources Information Center

    Kirby, Charlotte O.

    1990-01-01

    The Tri-District Arts Consortium in South Carolina was formed to serve artistically gifted students in grades six-nine. The consortium developed a summer program offering music, dance, theatre, and visual arts instruction through a curriculum of intense training, performing, and hands-on experiences with faculty members and guest artists. (JDD)

  12. Dropout Interviews: Summer, 1982, Final Technical Report.

    ERIC Educational Resources Information Center

    Austin Independent School District, TX. Office of Research and Evaluation.

    In the summer of 1982, the Austin Independent School District (AISD) Office of Research and Evaluation (ORE) conducted a survey of dropouts. Dropouts are defined in this study as students who withdrew from AISD schools prior to receiving their high school diploma and are not known to have attended other schools. The dropouts were interviewed to…

  13. The Simeon Cadre in Formation, Summer 1970.

    ERIC Educational Resources Information Center

    Sharpo, Calvin

    This report explicates the concrete group development of a cadre of persons from Simeon High School, the University of Chicago, and the Board of Education in the summer sector of the Ford Training and Placement Program. The report is organized around crucial indices of group development, i.e., the problem of leadership. Data were collected from…

  14. Summer Sunset: A new ornamental blueberry variety

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Summer Sunset’ is a new blueberry hybrid (Vaccinium sp.) jointly released by the University of Georgia College of Agricultural and Environmental Sciences, the University of Georgia Agricultural Experiment Station, and the United States Department of Agriculture - Agricultural Research Service for t...

  15. The summer I learned to write.

    PubMed

    Scholler-Jaquish, A

    1995-01-01

    A summer course in English grammar challenged a registered nurse student to learn new behaviors and acquire effective writing skills. A confident nursing writer now, the author shares her experience for registered nurse students who continue to face some of the same challenges.

  16. What Students Do in the Summer.

    ERIC Educational Resources Information Center

    Bracey, Gerald

    2002-01-01

    Discusses results of a study and report on the academic achievement of low-socioeconomic students. The study, conducted by Johns Hopkins University researchers Alexander, Entwisle, and Olson, appears in summer 2001 issue of "Educational Evaluation and Policy Analysis." The report, "Raising Achievement and Reducing Gaps," by Paul Barton, is…

  17. Welcome Summer with Some Festive Shirts

    ERIC Educational Resources Information Center

    Moore, Temple Skelton

    2011-01-01

    This article describes an art lesson that allows students to create a bit of fun with a festive shirt that welcomes the warm, carefree summer days. In this lesson, the students investigate the connection between patterns and rhythm, create variety using different-sized designs, and discuss personal artwork and the artwork of others.

  18. Emergency Immigration Education Act Programs. Summer ESL Welcome Program for Students of Limited English Proficiency, Summer Bilingual Program, Projects Omega, Wise, and Bell. Summer 1994. OER Report.

    ERIC Educational Resources Information Center

    Roman, Elliott M.

    The Emergency Immigration Education Act supported three distinct programs in New York City in the summer of 1994: (1) the Summer English as a Second Language (ESL) Welcome Program for Students of Limited English Proficiency; (2) the Summer Bilingual Program; and (3) Projects Omega, Wise, and Bell. The projects served 3,443 students in all. The…

  19. European summer temperatures since Roman times

    NASA Astrophysics Data System (ADS)

    Luterbacher, Jürg

    2016-04-01

    The spatial context is critical when assessing present-day climate anomalies, attributing them to potential forcings and making statements regarding their frequency and severity in a long-term perspective. Recent international initiatives have expanded the number of high-quality proxy-records and developed new statistical reconstruction methods. These advances allow more rigorous regional past temperature reconstructions and, in turn, the possibility of evaluating climate models on policy-relevant, spatio-temporal scales. Here we provide a new proxy-based, annually-resolved, spatial reconstruction of the European summer (June-August) temperature fields back to 755 CE based on Bayesian hierarchical modelling (BHM), together with estimates of the European mean temperature variation since 138 BCE based on BHM and composite-plus-scaling (CPS). Our reconstructions compare well with independent instrumental and proxy-based temperature estimates, but suggest a larger amplitude in summer temperature variability than previously reported. Both CPS and BHM reconstructions indicate that the mean 20th century European summer temperature was not significantly different from some earlier centuries, including the 1st, 2nd, 8th and 10th centuries CE. The 1st century (in BHM also the 10th century) may even have been slightly warmer than the 20th century, but the difference is not statistically significant. Comparing each 50 yr period with the 1951-2000 period reveals a similar pattern. Recent summers, however, have been unusually warm in the context of the last two millennia and there are no 30-yr periods in either reconstruction that exceed the mean average European summer temperature of the last 3 decades (1986-2015 CE). A comparison with an ensemble of climate model simulations suggests that the reconstructed European summer temperature variability over the period 850-2000 CE reflects changes in both internal variability and external forcing on multi-decadal time-scales. For pan

  20. Associated Western Universities summer participant program at the Lawrence Livermore National Laboratory, Summer 1997

    SciTech Connect

    Williams, B.

    1997-08-01

    The Associated Western Universities, Inc. (AWU) supports a student summer program at Lawrence Livermore National Laboratory (LLNL). This program is structured so that honors undergraduate students may participate in the Laboratory`s research program under direct supervision of senior Laboratory scientists. Included in this report is a list of the AWU participants for the summer of 1997. All students are required to submit original reports of their summer activities in a format of their own choosing. These unaltered student reports constitute the major portion of this report.

  1. Predictability of the 1997 and 1998 South Asian Summer Monsoons

    NASA Technical Reports Server (NTRS)

    Schubert, Siegfred D.; Wu, Man Li

    2000-01-01

    The predictability of the 1997 and 1998 south Asian summer monsoon winds is examined from an ensemble of 10 Atmospheric General Circulation Model (AGCM) simulations with prescribed sea surface temperatures (SSTs) and soil moisture, The simulations are started in September 1996 so that they have lost all memory of the atmospheric initial conditions for the periods of interest. The model simulations show that the 1998 monsoon is considerably more predictable than the 1997 monsoon. During May and June of 1998 the predictability of the low-level wind anomalies is largely associated with a local response to anomalously warm Indian Ocean SSTs. Predictability increases late in the season (July and August) as a result of the strengthening of the anomalous Walker circulation and the associated development of easterly low level wind anomalies that extend westward across India and the Arabian Sea. During these months the model is also the most skillful with the observations showing a similar late-season westward extension of the easterly CD wind anomalies. The model shows little predictability or skill in the low level winds over southeast Asia during, 1997. Predictable wind anomalies do occur over the western Indian Ocean and Indonesia, however, over the Indian Ocean they are a response to SST anomalies that were wind driven and they show no skill. The reduced predictability in the low level winds during 1997 appears to be the result of a weaker (compared with 1998) simulated anomalous Walker circulation, while the reduced skill is associated with pronounced intraseasonal activity that is not well captured by the model. Remarkably, the model does produce an ensemble mean Madden-Julian Oscillation (MJO) response that is approximately in phase with (though weaker than) the observed MJ0 anomalies. This is consistent with the idea that SST coupling may play an important role in the MJO.

  2. Scaling properties of sea ice deformation during winter and summer

    NASA Astrophysics Data System (ADS)

    Hutchings, J. K.; Heil, P.; Roberts, A.

    2009-12-01

    We investigate sea ice deformation observed with ice drifting buoy arrays during two field campaigns. Ice Station POLarstern [ISPOL], deployed in the western Weddell Sea during November 2004 to January 2005, included a study of small-scale (sub-synoptic) variability in sea ice velocity and deformation using an array of 24 buoys. Upon deployment the ISPOL buoy array measured 70 km in both zonal and meridional extent, and consisted of sub-arrays that resolved sea ice deformation on scales from 10 to 70 km. The Sea Ice Experiment: Dynamic Nature of the Arctic (SEDNA) used two nested arrays of six buoys each as a backbone for the experiment, that were deployed in late March 2007. The two arrays were circular with diameter 140 km and 20 km. ISPOL and SEDNA provide insight into the scaling properties of sea ice deformation over scales of 10 to 200 km during early Astral summer and late Boreal winter. The ISPOL and SEDNA arrays were split into sets of sub-arrays with varying length scales. We find that variance of divergence decreases as the length scale increases. The mean divergence for each length scale set follows a log-linear scaling relationship with length scale. This is an independent verification of a previous result of Marsden, Stern, Lindsay and Weiss (2004). This scaling is indicative of a fractal process. Deformation occurs at linear features (cracks, leads and ridges) in the ice pack, that are distributed with scales that range from meter to hundreds of kilometers in length. The magnitude of deformation at these linear features varies by two orders of magnitude across scales. We demonstrate that the deformation at all these scales is important in the mass balance of sea ice. Which has important implications for the design of sea ice deformation monitoring systems.

  3. Helping the Habitually Late Student.

    ERIC Educational Resources Information Center

    Bergman, Jerry

    1978-01-01

    The author gives three major reasons for a student being habitually late to class: resistance, disorganization, or unavoidable schedule conflicts. He makes specific suggestions to teachers for dealing with the disorganized and resistant latecomers. (SJL)

  4. Late Blooming or Language Problem?

    MedlinePlus

    ... and Swallowing / Disorders and Diseases Late Blooming or Language Problem? Parents are smart. They listen to their ... or not their child is developing speech and language at a normal rate. If parents think that ...

  5. Vertically coupled dipolar exciton molecules

    NASA Astrophysics Data System (ADS)

    Cohen, Kobi; Khodas, Maxim; Laikhtman, Boris; Santos, Paulo V.; Rapaport, Ronen

    2016-06-01

    While the interaction potential between two dipoles residing in a single plane is repulsive, in a system of two vertically adjacent layers of dipoles it changes from repulsive interaction in the long range to attractive interaction in the short range. Here we show that for dipolar excitons in semiconductor heterostructures, such a potential may give rise to bound states if two such excitons are excited in two separate layers, leading to the formation of vertically coupled dipolar exciton molecules. Our calculations prove the existence of such bound states and predict their binding energy as a function of the layers separation as well as their thermal distributions. We show that these molecules should be observed in realistic systems such as semiconductor coupled quantum well structures and the more recent van der Waals bound heterostructures. Formation of such molecules can lead to new effects such as a collective dipolar drag between layers and new forms of multiparticle correlations, as well as to the study of dipolar molecular dynamics in a controlled system.

  6. Emergence of human influence on summer record-breaking temperatures over Europe

    NASA Astrophysics Data System (ADS)

    Bador, Margot; Terray, Laurent; Boé, Julien

    2016-01-01

    Observational analysis of Europe summer record-breaking temperatures suggests that their occurrence differs from that expected in a stationary climate since the late 1980s. The observed cold and warm record evolution is well simulated by the ensemble mean of 27 coupled models from the Coupled Model Intercomparison Project phase 5 (CMIP5). We find that this evolution is still today within the range of internal variability derived from CMIP5 preindustrial simulations. We then estimate a time of emergence of the summer record anthropogenic influence in a world under a business as usual greenhouse gas emission scenario. We suggest a time of emergence around 2020 for the cold records and 2030 for the warm ones with an uncertainty of ± 20 years. By 2100, the multimodel ensemble mean indicates a tenfold increase of the number of warm records compared to the first half of the twentieth century and the quasi-disappearance of cold records.

  7. Mars south polar spring and summer temperatures - A residual CO2 frost

    NASA Technical Reports Server (NTRS)

    Kieffer, H. H.

    1979-01-01

    Viking infrared thermal mapper (IRTM) energy measurements over the Mars south polar cap throughout the Martian spring and summer revealed complex spatial, spectral, and temporal variations. High albedos did not directly correspond with low temperatures, and as the cap shrank to its residual position, it maintained large differences in brightness temperature between the four IRTM surface-sensing bands at 7, 9, 11, and 20 microns. The late summer infrared spectral pattern can be matched by a surface consisting of CO2 frost with 20 micron emissivity of 0.8 and about 6% dark, warm soil under a dusty atmosphere of moderate infrared opacity and spectral properties similar to those measured for the Martian global dust storms. Low temperature, the absence of appreciable water vapor in the south polar atmosphere, and the absence of surface warming expected if H2O were to become exposed, all imply that the residual south polar cap was covered by solid CO2.

  8. Late and chronic Lyme disease.

    PubMed

    Donta, Sam T

    2002-03-01

    This article reviews the late and chronic manifestations of Lyme disease. Special attention is given to the chronic manifestations of the disease, detailing its pathogenesis, clinical spectrum, and laboratory criteria for the diagnosis. Based on experimental evidence and experience, approaches to the successful treatment of the late and chronic disease are outlined. Much additional work is needed to improve the understanding of the underlying pathophysiology of the disease, its diagnosis and treatment.

  9. Baja california: late cretaceous dinosaurs.

    PubMed

    Morris, W J

    1967-03-24

    Late Cretaceous dinosaurs have been discovered along the Pacific margin of Baja California. The presence of Hypacrosaurus sp. is suggestive of correlation with the Upper Edmonton Formation, Alberta. Dissimilarities between the Baja California fauna and those from contemporary units along the eastern trend of the Rocky Mountains suggest that Baja California was ecologically separated from mainland Mexico during late Campanian and early Maastrictian time. PMID:17830047

  10. Vertical Deformation of Late Quaternary Features Across Port-au-Prince Bay, Haiti

    NASA Astrophysics Data System (ADS)

    Cormier, M.; McHugh, C. M.; Gulick, S. P.; Braudy, N.; Davis, M. B.; Diebold, J. B.; Dieudonne, N.; Douilly, R.; Hornbach, M. J.; Johnson, H. E.; Mishkin, K.; Seeber, L.; Sorlien, C. C.; Steckler, M. S.; Symithe, S. J.; Templeton, J.

    2010-12-01

    As part of a project that investigated the underwater impacts of the January 12, 2010 earthquake in Haiti, we surveyed offshore structures that may have been activated during that earthquake or that might become activated in future earthquakes. Part of that survey focused on the shallow shelf area that extends north of the segment of the Enriquillo-Plantain Garden fault that just ruptured. This area is occupied by an elongated depression, 25 km long, 10 km wide, and 140 m deep. The NW-SE axis of that shallow basin is sub-parallel to that of the NW-SE anticlines that bounds Port-au-Prince Bay. The shallow basin is also rimmed by a carbonate platform that is 5-10 km-wide and ~30m deep. New multibeam bathymetric and sidescan sonar data collected across that platform highlight a series of circular dissolution structures 1-2 km across and ~80 m deep. We interpret that morphology to indicate antecedent karst topography that developed during previous glacial maxima. According to that scenario, the shallow basin off Port-au-Prince would have been isolated from the Caribbean Sea by the continuous platform, and would probably have been occupied by a lagoon. Indeed, a few high-resolution chirp profiles image what may be a paleoshoreline at about 80m depth, buried beneath a 5-8 m thick, acoustically transparent, presumably Holocene layer. Preliminary analysis indicates that the basin floor and the base of the presumably Holocene layer are perfectly horizontal in the center of the basin, but tilted down to the south at its northern edge. The presumed paleoshoreline is also shallower to the north of the basin. We propose that this tilt is driven by contraction across the NW-SE fold-and-thrust belt that runs across Hispaniola. This hypothesis remains to be tested with a more thorough geophysical and coring survey in Port-au-Prince Bay.

  11. Effect of summer throughfall exclusion, summer drought, and winter snow cover on methane fluxes in a temperate forest soil

    USGS Publications Warehouse

    Borken, W.; Davidson, E.A.; Savage, K.; Sundquist, E.T.; Steudler, P.

    2006-01-01

    Soil moisture strongly controls the uptake of atmospheric methane by limiting the diffusion of methane into the soil, resulting in a negative correlation between soil moisture and methane uptake rates under most non-drought conditions. However, little is known about the effect of water stress on methane uptake in temperate forests during severe droughts. We simulated extreme summer droughts by exclusion of 168 mm (2001) and 344 mm (2002) throughfall using three translucent roofs in a mixed deciduous forest at the Harvard Forest, Massachusetts, USA. The treatment significantly increased CH4 uptake during the first weeks of throughfall exclusion in 2001 and during most of the 2002 treatment period. Low summertime CH4 uptake rates were found only briefly in both control and exclusion plots during a natural late summer drought, when water contents below 0.15 g cm-3 may have caused water stress of methanotrophs in the A horizon. Because these soils are well drained, the exclusion treatment had little effect on A horizon water content between wetting events, and the effect of water stress was smaller and more brief than was the overall treatment effect on methane diffusion. Methane consumption rates were highest in the A horizon and showed a parabolic relationship between gravimetric water content and CH4 consumption, with maximum rate at 0.23 g H2O g-1 soil. On average, about 74% of atmospheric CH4 was consumed in the top 4-5 cm of the mineral soil. By contrast, little or no CH4 consumption occurred in the O horizon. Snow cover significantly reduced the uptake rate from December to March. Removal of snow enhanced CH4 uptake by about 700-1000%, resulting in uptake rates similar to those measured during the growing season. Soil temperatures had little effect on CH4 uptake as long as the mineral soil was not frozen, indicating strong substrate limitation of methanotrophs throughout the year. Our results suggest that the extension of snow periods may affect the annual rate

  12. Late effects from hadron therapy

    SciTech Connect

    Blakely, Eleanor A.; Chang, Polly Y.

    2004-06-01

    Successful cancer patient survival and local tumor control from hadron radiotherapy warrant a discussion of potential secondary late effects from the radiation. The study of late-appearing clinical effects from particle beams of protons, carbon, or heavier ions is a relatively new field with few data. However, new clinical information is available from pioneer hadron radiotherapy programs in the USA, Japan, Germany and Switzerland. This paper will review available data on late tissue effects from particle radiation exposures, and discuss its importance to the future of hadron therapy. Potential late radiation effects are associated with irradiated normal tissue volumes at risk that in many cases can be reduced with hadron therapy. However, normal tissues present within hadron treatment volumes can demonstrate enhanced responses compared to conventional modes of therapy. Late endpoints of concern include induction of secondary cancers, cataract, fibrosis, neurodegeneration, vascular damage, and immunological, endocrine and hereditary effects. Low-dose tissue effects at tumor margins need further study, and there is need for more acute molecular studies underlying late effects of hadron therapy.

  13. Trend analysis of tropical intraseasonal oscillations in the summer and winter during 1982-2009

    NASA Astrophysics Data System (ADS)

    Tao, Li; Zhao, Jiuwei; Li, Tim

    2015-04-01

    Based on the daily outgoing long-wave radiation (OLR) data of the National Oceanic and Atmospheric Administration (NOAA) from 1979 to 2012, we investigated the intensity changes of the 20-70-d boreal summer (June-September; JJAS) intra-seasonal oscillation (BSISO) and winter (December-February; DJF) intra-seasonal oscillation, also known as the Madden-Julian Oscillation (MJO). The results showed that the intensity of the BSISO has a significant intensifying trend during 1982-2009. On the other hand, little trend was found for boreal winter MJO during this period. The wavenumber-frequency analysis (Hayashi, 1982) was applied to separate ISO into westward propagation and eastward propagation parts. The significant intensified trend was observed over tropical Indian Ocean for the eastward-propagation BSISO. The weakened but not significant trend was observed over southern tropical Indian Ocean for the eastward-propagation MJO. To gain insight into the different ISO characteristics, the tendencies of sea surface temperature (SST) and the vertical shear of zonal wind were analyzed. The results showed that in both seasons from 1982 to 2009, the global SST trends were similar, and thus they could not be used to explain the BSISO upward trend. However, lower-tropospheric easterly shear in boreal summer over tropical Indian Ocean has a decreasing trend, while the easterly vertical shear over maritime continent was enhanced in winter. It is proposed that the reduced easterly vertical shear over tropical Indian Ocean favored the amplification of the eastward-propagating Kelvin wave, which led to the intensified eastward-propagating BSISO. The enhanced easterly vertical shear over maritime continent might be unfavorable to the amplification of the eastward-propagating Kelvin wave, but its impact was offset by the enhanced upward motion over maritime continent. As a result, there was little trend of the MJO in boreal winter. The hypothesis above was further verified by

  14. Vertical ozone characteristics in urban boundary layer in Beijing.

    PubMed

    Ma, Zhiqiang; Xu, Honghui; Meng, Wei; Zhang, Xiaoling; Xu, Jing; Liu, Quan; Wang, Yuesi

    2013-07-01

    Vertical ozone and meteorological parameters were measured by tethered balloon in the boundary layer in the summer of 2009 in Beijing, China. A total of 77 tethersonde soundings were taken during the 27-day campaign. The surface ozone concentrations measured by ozonesondes and TEI 49C showed good agreement, albeit with temporal difference between the two instruments. Two case studies of nocturnal secondary ozone maxima are discussed in detail. The development of the low-level jet played a critical role leading to the observed ozone peak concentrations in nocturnal boundary layer (NBL). The maximum of surface ozone was 161.7 ppbv during the campaign, which could be attributed to abundant precursors storage near surface layer at nighttime. Vertical distribution of ozone was also measured utilizing conventional continuous analyzers on 325-m meteorological observation tower. The results showed the NBL height was between 47 and 280 m, which were consistent with the balloon data. Southerly air flow could bring ozone-rich air to Beijing, and the ozone concentrations exceeded the China's hourly ozone standard (approximately 100 ppb) above 600 m for more than 12 h.

  15. Alpbach Summer School - a unique learning experience

    NASA Astrophysics Data System (ADS)

    Kern, K.; Aulinas, J.; Clifford, D.; Krejci, D.; Topham, R.

    2011-12-01

    The Alpbach Summer School is a ten-day program that provides a unique opportunity for young european science and engineering students, both undergraduate and graduate, to learn how to approach the entire design process of a space mission. The theme of the 2010 Summer School was "New Space Missions to Understand Climate Change", a current, challenging, very broad and complex topic. The program was established more than 35 years ago and is organised in two interrelated parts: a series of lectures held by renowned experts in the field (in the case of this specific year, climate change and space engineering experts) that provides a technical and scientific background for the workshops that follow, the core of the Summer School. For the workshops the students are split into four international, interdisciplinary teams of about 15 students. In 2010 every team had to complete a number of tasks, four in total: (1) identify climate change research gaps and design a space mission that has not yet been flown or proposed, (2) define the science objectives and requirements of the mission, (3) design a spacecraft that meets the mission requirements, which includes spacecraft design and construction, payload definition, orbit calculations, but also the satellite launch, operation and mission costs and (4) write up a short mission proposal and present the results to an expert review panel. Achieving these tasks in only a few days in a multicultural, interdisciplinary team represents a major challenge for all participants and provides an excellent practical learning experience. Over the course of the program, students do not just learn facts about climate change and space engineering, but scientists also learn from engineers and engineers from scientists. The participants have to deepen their knowledge in an often unfamiliar field, develop organisational and team-work skills and work under pressure. Moreover, teams are supported by team and roving tutors and get the opportunity to

  16. Summer Drying Under Enhanced Greenhouse Gas Warming

    NASA Astrophysics Data System (ADS)

    Roesch, A.; Wild, M.; Tschuck, P.

    2005-12-01

    Present day climate and future climate projections from the latest version of the Max Planck Institute GCM, ECHAM5, at T106 resolution are used to investigate changes in the near-surface climate, focusing on summer in Europe. For the control climate, ECHAM5 has been integrated over the period 1961 to 1990, using sea surface temperature (SST) and sea ice cover (SIC) provided by the EU project PRUDENCE. Projections of future climate are based on the SRES scenario A2 from 2071-2100. SST and SIC were inferred from a coupled transient experiment carried out at the Hadley Centre with HadCM3. In summer, precipitation in the future climate integration decreases over most of continental Europe excluding Northern Scandinavia. This leads to a distinct decrease in soil moisture, with maximum absolute changes in Central Europe and Northern Spain. The highest negative signal in evaporation is found over Southern Europe where water is already limited under present-day climate conditions. This feature is closely related to the strong decrease of the water stress factor south of approximately 46N. The Bowen ratio will decline by more than 3 during the pronounced summer drying in Southern Spain, South Italy and Greece, implying a reduced evaporative cooling and thus a strong warming. In contrast, water hardly becomes a limiting factor in Central and Northern Europe in summer. The variability of summer temperatures generally increases slightly over Central Europe. Additionally, the widening of the statistical distribution exceeds 20% in major parts in Southern Europe since these areas are more often affected by summer droughts. For precipitation, the coefficient of variance (the standard deviation divided by its mean) increases by more than 100% over major parts of the Iberian Peninsula, indicating that the normalized precipitation variability significantly increases over the strongly water-limited region. In winter, ECHAM5 simulates a water-limited climate only in a minor part of

  17. Arctic summer school onboard an icebreaker

    NASA Astrophysics Data System (ADS)

    Alexeev, Vladimir A.; Repina, Irina A.

    2014-05-01

    The International Arctic Research Center (IARC) of the University of Alaska Fairbanks conducted a summer school for PhD students, post-docs and early career scientists in August-September 2013, jointly with an arctic expedition as a part of NABOS project (Nansen and Amundsen Basin Observational System) onboard the Russian research vessel "Akademik Fedorov". Both the summer school and NABOS expedition were funded by the National Science Foundation. The one-month long summer school brought together graduate students and young scientists with specialists in arctic oceanography and climate to convey to a new generation of scientists the opportunities and challenges of arctic climate observations and modeling. Young scientists gained hands-on experience during the field campaign and learned about key issues in arctic climate from observational, diagnostic, and modeling perspectives. The summer school consisted of background lectures, participation in fieldwork and mini-projects. The mini-projects were performed in collaboration with summer school instructors and members of the expedition. Key topics covered in the lectures included: - arctic climate: key characteristics and processes; - physical processes in the Arctic Ocean; - sea ice and the Arctic Ocean; - trace gases, aerosols, and chemistry: importance for climate changes; - feedbacks in the arctic system (e.g., surface albedo, clouds, water vapor, circulation); - arctic climate variations: past, ongoing, and projected; - global climate models: an overview. An outreach specialist from the Miami Science Museum was writing a blog from the icebreaker with some very impressive statistics (results as of January 1, 2014): Total number of blog posts: 176 Blog posts written/contributed by scientists: 42 Blog views: 22,684 Comments: 1,215 Number of countries who viewed the blog: 89 (on 6 continents) The 33-day long NABOS expedition started on August 22, 2013 from Kirkenes, Norway. The vessel ("Akademik Fedorov") returned to

  18. Bowhead whale body condition and links to summer sea ice and upwelling in the Beaufort Sea

    NASA Astrophysics Data System (ADS)

    George, John C.; Druckenmiller, Matthew L.; Laidre, Kristin L.; Suydam, Robert; Person, Brian

    2015-08-01

    We examined the response of bowhead whale (Balaena mysticetus) body condition to summer sea ice conditions and upwelling-favorable winds. We used a long-term dataset collected from whales of the Bering-Chukchi-Beaufort Seas (BCB) stock to estimate various body condition indices (BCI's) for individual whales that were harvested by Alaskan Eskimos. A series of offshore regions frequented by bowhead whales in summer were delineated and used to quantify interannual summertime environmental conditions including: (a) mean open water fraction, (b) duration of melt season, (c) date of continuous freeze-up, and (d) mean upwelling-favorable wind stress. Body condition was analyzed relative to these metrics for both the preceding summer feeding season and the previous three seasons combined. Our analysis indicates a significant increase in the long-term trend in an axillary girth-based body condition index (BCIG) over the study period (1989-2011). The increase in BCIG is likely associated with the trend in overall reduction of sea ice, including increased duration of open water, changes in upwelling potential (wind stress), and possibly higher primary production in the Pacific Arctic marine ecosystem favoring water-column invertebrates. We found strong significant positive correlations between BCIG and late summer open water fraction in the Beaufort Sea and smaller nearshore areas off the Mackenzie Delta and west of Banks Island. Additionally, BCIG was positively and significantly correlated with duration of melt season, later date of freeze-up in the Beaufort Sea, and upwelling-favorable winds on the Mackenzie shelf and west of Banks Island. A strong seasonal difference in BCI's was noted for subadult bowheads, presumably associated with summer feeding; however, yearlings were found to drop in BCI over at least the first summer after weaning. Our results indicate an overall increase in bowhead whale body condition and a positive correlation with summer sea ice loss over the

  19. Rethinking the Recent Advance of Asian Summer Monsoon Onset

    NASA Astrophysics Data System (ADS)

    Xiang, B.; Wang, B.

    2012-12-01

    Understanding the monsoon onset change is of utmost importance especially for agriculture planning and water management. In the last three decades, Asian Summer Monsoon (ASM) onset has remarkably advanced, but the physical mechanisms remain elusive. Since the overall ASM onset occurs in May, we focus on the change of mean fields in May and consider enhanced mean precipitation and monsoon westerly winds as signs of advanced onset. Results show that the advanced ASM onset mainly represents a robust decadal shift in the mid-to-late 1990s, which is attributed to the mean state change in the Pacific basin characterized by a grand La Niña-like pattern. The La Niña-like mean state change controls the ASM onset through the westward propagation of Rossby waves and its interaction with the asymmetric background mean states in the Indian Ocean and western Pacific, which facilitates the amplification of the northern hemispheric perturbations as well as intensified westerly winds. Intriguingly, the abrupt decadal shifts of monsoon onset in the Arabian Sea and Bay of Bengal occur in 1999, in contrast to the South China Sea with decadal shift in 1994. Numerical experiments demonstrate that the advanced monsoon onset in the Arabian Sea and Bay of Bengal is governed by the enhanced zonal sea surface temperature (SST) gradients in the equatorial Pacific, while that in the South China Sea is primarily determined by the abrupt SST warming near the Philippine Sea.

  20. Green Summer and Icy Winter in James Bay

    NASA Technical Reports Server (NTRS)

    2001-01-01

    One year ago, in late February 2000, MISR began acquiring Earth imagery. Its 'first light' images showed a frozen James Bay in the Ontario-Quebec region of Canada. These more recent nadir-camera views of the same area illuminate stark contrasts between summer and winter. The left-hand image was acquired on August 9, 2000 (Terra orbit 3427), and the right-hand image is from January 16, 2001 (Terra orbit 5757).

    James Bay lies at the southern end of Hudson Bay. It is named for the English explorer Thomas James, who first explored the area in 1631 while searching for the Northwest Passage. Visible in these images are some of the many rivers that flow into the bay; starting at the southern tip and moving clockwise on the western side are the Harricana, Moose, Albany, and Attawapiskat. The latter enters the bay just to the west of the large, crescent-shaped Akimiski Island.

    MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.