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Sample records for winter weddell gyre

  1. Annual export production in the interior Weddell Gyre estimated from a chemical mass balance of nutrients

    NARCIS (Netherlands)

    Hoppema, Mario; Baar, Hein J.W. de; Bellerby, Richard G.J.; Fahrbach, Eberhard; Bakker, Karel

    2002-01-01

    Nitrate, phosphate and silicate data are presented from 1992 austral winter and 1998 austral autumn cruises with “FS Polarstern” in the Weddell Gyre. Because in the Weddell Gyre, away from the boundary current, the surface layer is eventually formed from upwelled deep water, the difference in

  2. Transport and structure of the Weddell Gyre

    Directory of Open Access Journals (Sweden)

    E. Fahrbach

    1994-08-01

    Full Text Available A cyclonic gyre controls the advection of source waters into the formation areas of bottom water in the southern and western parts of the Weddell Sea and the subsequent transport of modified water masses to the north. Determination of the structure of the Weddell Gyre and of the associated transports was one of the objectives of the "Weddell Gyre Study" which began in September 1989 and ended in January 1993. The collected data set comprises records of moored current meters and profiles of temperature and salinity distributed along a transect between the northern tip of the Antarctic Peninsula and Kapp Norvegia. The circulation pattern on the transect is dominated by stable boundary currents of several hundred kilometers width at the eastern and western sides of the basin. They are of comparable size on both sides and provide nearly 90% of the volume transport of the gyre which amounts to 29.5 Sv. In the interior, a weak anticyclonic cell of 800 km diameter transports less than 4 Sv. Apart from the continental slopes, the near-bottom currents flow at some locations in an opposite direction to those in the water column above, indicating a significant baroclinic component of the current field. The intensity of the boundary currents is subject to seasonal fluctuations, whereas in the interior, time scales from days to weeks dominate. The large-scale circulation pattern is persistent during the years 1989 to 1991. The heat transport into the southern Weddell Sea is estimated to be 3.48×1013 W. This implies an equivalent heat loss through the sea surface of 19 W m-2, as an average value for the area south of the transect. The derived salt transport is not significantly different from zero; consequently, the salt gain by sea ice formation has to compensate almost entirely the fresh water gain from the melting ice shelves and from precipitation. Estimation of water mass formation rates from the thermohaline differences of the inflow and outflow

  3. Transport and structure of the Weddell Gyre

    Directory of Open Access Journals (Sweden)

    E. Fahrbach

    Full Text Available A cyclonic gyre controls the advection of source waters into the formation areas of bottom water in the southern and western parts of the Weddell Sea and the subsequent transport of modified water masses to the north. Determination of the structure of the Weddell Gyre and of the associated transports was one of the objectives of the "Weddell Gyre Study" which began in September 1989 and ended in January 1993. The collected data set comprises records of moored current meters and profiles of temperature and salinity distributed along a transect between the northern tip of the Antarctic Peninsula and Kapp Norvegia. The circulation pattern on the transect is dominated by stable boundary currents of several hundred kilometers width at the eastern and western sides of the basin. They are of comparable size on both sides and provide nearly 90% of the volume transport of the gyre which amounts to 29.5 Sv. In the interior, a weak anticyclonic cell of 800 km diameter transports less than 4 Sv. Apart from the continental slopes, the near-bottom currents flow at some locations in an opposite direction to those in the water column above, indicating a significant baroclinic component of the current field. The intensity of the boundary currents is subject to seasonal fluctuations, whereas in the interior, time scales from days to weeks dominate. The large-scale circulation pattern is persistent during the years 1989 to 1991. The heat transport into the southern Weddell Sea is estimated to be 3.48×1013 W. This implies an equivalent heat loss through the sea surface of 19 W m-2, as an average value for the area south of the transect. The derived salt transport is not significantly different from zero; consequently, the salt gain by sea ice formation has to compensate almost entirely the fresh water gain from the melting ice shelves and from precipitation. Estimation of water mass formation rates from the thermohaline differences of the

  4. Rapid invasion of anthropogenic CO2 into the deep circulation of the Weddell Gyre

    NARCIS (Netherlands)

    van Heuven, S.M.A.C.; Hoppema, M.; Jones, E.M.; de Baar, H.J.W.

    2014-01-01

    Data are presented for total carbon dioxide (TCO2), oxygen and nutrients from 14 cruises covering two repeat sections across the Weddell Gyre, from 1973 to 2010. Assessments of the rate of increase in anthropogenic CO2 (Cant) are made at three locations. Along the Prime Meridian, TCO2 is observed to

  5. A rapid transition from ice covered CO2–rich waters to a biologically mediated CO2 sink in the eastern Weddell Gyre

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    W. Geibert

    2008-09-01

    Full Text Available Circumpolar Deep Water (CDW, locally called Warm Deep Water (WDW, enters the Weddell Gyre in the southeast, roughly at 25° E to 30° E. In December 2002 and January 2003 we studied the effect of entrainment of WDW on the fugacity of carbon dioxide (fCO2 and dissolved inorganic carbon (DIC in Weddell Sea surface waters. Ultimately the fCO2 difference across the sea surface drives air-sea fluxes of CO2. Deep CTD sections and surface transects of fCO2 were made along the Prime Meridian, a northwest-southeast section, and along 17° E to 23° E during cruise ANT XX/2 on FS Polarstern. Upward movement and entrainment of WDW into the winter mixed layer had significantly increased DIC and fCO2 below the sea ice along 0° W and 17° E to 23° E, notably in the southern Weddell Gyre. Nonetheless, the ice cover largely prevented outgassing of CO2 to the atmosphere. During and upon melting of the ice, biological activity rapidly reduced surface water fCO2 by up to 100 μatm, thus creating a sink for atmospheric CO2. Despite the tendency of the surfacing WDW to cause CO2 supersaturation, the Weddell Gyre may well be a CO2 sink on an annual basis due to this effective mechanism involving ice cover and ensuing biological fCO2 reduction. Dissolution of calcium carbonate (CaCO3 in melting sea ice may play a minor role in this rapid reduction of surface water fCO2.

  6. Direct observation of increasing CO 2 in the Weddell Gyre along the Prime Meridian during 1973-2008

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    van Heuven, Steven M. A. C.; Hoppema, Mario; Huhn, Oliver; Slagter, Hans A.; de Baar, Hein J. W.

    2011-12-01

    The World Ocean takes up a large portion of the anthropogenic CO 2 emitted into the atmosphere. Determining the resulting increase in dissolved inorganic carbon ( CT, expressed in μmol kg -1) is challenging, particularly in the sub-surface and deep Southern Ocean where the time rate of change of CT (in μmol kg -1 decade -1) is commonly expected to be low. We present a determination of this time trend of CT in a dataset of measurements that spans 35 years comprising 10 cruises in the 1973-2008 period along the 0°-meridian in the Weddell Gyre. The inclusion of many cruises aims to generate results that are more robust than may be obtained by taking the difference between only one pair of cruises, each of which may suffer from errors in accuracy. To further improve consistency between cruises, data were adjusted in order to obtain time-invariant values of CT (and other relevant parameters) over the 35 years in the least ventilated local water body, this comprising the deeper Warm Deep Water (WDW) and upper Weddell Sea Deep Water (WSDW). It is assumed that this normalization procedure will allow trends in CT in the more intensely ventilated water masses to be more clearly observed. Time trends were determined directly in measurements of CT, and alternatively in back-calculated values of preformed CT ( CT0; i.e., the CT of the water at the time that it lost contact with the atmosphere). The determined time trends may be attributed to a combination of natural variability (in hydrography or biogeochemistry) and increased uptake of anthropogenic CO 2 from the atmosphere. In order to separate these natural and anthropogenic components, an analysis of the residuals of a multivariate linear regression (MLR), involving the complete time series of all 10 cruises, was additionally performed. This approach is referred to as the Time Series Residuals (TSR) approach. Using the direct method, the time trends of CT in the WSDW are quite small and non-significant at +0.176±0.321

  7. Bimodal Winter Haul-Out Patterns of Adult Weddell Seals (Leptonychotes weddellii) in the Southern Weddell Sea.

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    Boehme, Lars; Baker, Amy; Fedak, Mike; Årthun, Marius; Nicholls, Keith; Robinson, Patrick; Costa, Dan; Biuw, Martin; Photopoulou, Theoni

    2016-01-01

    Hauling out is an essential component of pinniped life-history. Haul-out behaviour may be affected by biological (e.g. sex, age and condition) and physical factors (e.g. food availability and environmental conditions), and identifying these factors may help explain the spatio-temporal distribution and habitat use of pinnipeds. The aim of this study is to describe observed winter haul-out patterns of adult Weddell seals in the Weddell Sea and investigate the role of potential predictors to gain insight into the way these animals interact with the physical environment in this region. We examined the haul-out behaviour in relation to available biological (i.e., diving effort, sex) and physical information (i.e., sun angle). Thirty-three satellite telemetry tags were deployed on adult Weddell seals in the southern Weddell Sea during February 2007, 2009 and 2011, following their annual moult recording information on the behavioural mode of the animal: at surface, hauled out or diving. At the end of the austral summer Weddell seals spent, on average, more than 40% of their time hauled out on the ice. Under constant light conditions, it appears that physiological factors drive sex differences in the timing and duration of haul-out behaviour, with females spending on average more time hauled out than males during daylight hours. This time spent hauled-out declined to around 15% in both sexes by the beginning of autumn and remained at this level with a clear nocturnal haul-out pattern during the winter. The time spent diving increased during this period, indicating an increase in foraging effort during the winter months, and led to a common haul-out pattern in both sexes over winter. We found a positive relationship between haul-out duration and the percentage of time spent diving prior to a haul-out in both sexes, with the exception of female daytime haul-outs early in the year.

  8. Unexpected winter phytoplankton blooms in the North Atlantic subpolar gyre

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    Lacour, L.; Ardyna, M.; Stec, K. F.; Claustre, H.; Prieur, L.; Poteau, A.; D'Alcala, M. Ribera; Iudicone, D.

    2017-11-01

    In mid- and high-latitude oceans, winter surface cooling and strong winds drive turbulent mixing that carries phytoplankton to depths of several hundred metres, well below the sunlit layer. This downward mixing, in combination with low solar radiation, drastically limits phytoplankton growth during the winter, especially that of the diatoms and other species that are involved in seeding the spring bloom. Here we present observational evidence for widespread winter phytoplankton blooms in a large part of the North Atlantic subpolar gyre from autonomous profiling floats equipped with biogeochemical sensors. These blooms were triggered by intermittent restratification of the mixed layer when mixed-layer eddies led to a horizontal transport of lighter water over denser layers. Combining a bio-optical index with complementary chemotaxonomic and modelling approaches, we show that these restratification events increase phytoplankton residence time in the sunlight zone, resulting in greater light interception and the emergence of winter blooms. Restratification also caused a phytoplankton community shift from pico- and nanophytoplankton to phototrophic diatoms. We conclude that transient winter blooms can maintain active diatom populations throughout the winter months, directly seeding the spring bloom and potentially making a significant contribution to over-winter carbon export.

  9. Modification of the deep salinity-maximum in the Southern Ocean by circulation in the Antarctic Circumpolar Current and the Weddell Gyre

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    Donnelly, Matthew; Leach, Harry; Strass, Volker

    2017-07-01

    The evolution of the deep salinity-maximum associated with the Lower Circumpolar Deep Water (LCDW) is assessed using a set of 37 hydrographic sections collected over a 20-year period in the Southern Ocean as part of the WOCE/CLIVAR programme. A circumpolar decrease in the value of the salinity-maximum is observed eastwards from the North Atlantic Deep Water (NADW) in the Atlantic sector of the Southern Ocean through the Indian and Pacific sectors to Drake Passage. Isopycnal mixing processes are limited by circumpolar fronts, and in the Atlantic sector, this acts to limit the direct poleward propagation of the salinity signal. Limited entrainment occurs into the Weddell Gyre, with LCDW entering primarily through the eddy-dominated eastern limb. A vertical mixing coefficient, κV of (2.86 ± 1.06) × 10-4 m2 s-1 and an isopycnal mixing coefficient, κI of (8.97 ± 1.67) × 102 m2 s-1 are calculated for the eastern Indian and Pacific sectors of the Antarctic Circumpolar Current (ACC). A κV of (2.39 ± 2.83) × 10-5 m2 s-1, an order of magnitude smaller, and a κI of (2.47 ± 0.63) × 102 m2 s-1, three times smaller, are calculated for the southern and eastern Weddell Gyre reflecting a more turbulent regime in the ACC and a less turbulent regime in the Weddell Gyre. In agreement with other studies, we conclude that the ACC acts as a barrier to direct meridional transport and mixing in the Atlantic sector evidenced by the eastward propagation of the deep salinity-maximum signal, insulating the Weddell Gyre from short-term changes in NADW characteristics.

  10. Biogeochemical Impact of Snow Cover and Cyclonic Intrusions on the Winter Weddell Sea Ice Pack

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    Tison, J.-L.; Schwegmann, S.; Dieckmann, G.; Rintala, J.-M.; Meyer, H.; Moreau, S.; Vancoppenolle, M.; Nomura, D.; Engberg, S.; Blomster, L. J.; Hendrickx, S.; Uhlig, C.; Luhtanen, A.-M.; de Jong, J.; Janssens, J.; Carnat, G.; Zhou, J.; Delille, B.

    2017-12-01

    Sea ice is a dynamic biogeochemical reactor and a double interface actively interacting with both the atmosphere and the ocean. However, proper understanding of its annual impact on exchanges, and therefore potentially on the climate, notably suffer from the paucity of autumnal and winter data sets. Here we present the results of physical and biogeochemical investigations on winter Antarctic pack ice in the Weddell Sea (R. V. Polarstern AWECS cruise, June-August 2013) which are compared with those from two similar studies conducted in the area in 1986 and 1992. The winter 2013 was characterized by a warm sea ice cover due to the combined effects of deep snow and frequent warm cyclones events penetrating southward from the open Southern Ocean. These conditions were favorable to high ice permeability and cyclic events of brine movements within the sea ice cover (brine tubes), favoring relatively high chlorophyll-a (Chl-a) concentrations. We discuss the timing of this algal activity showing that arguments can be presented in favor of continued activity during the winter due to the specific physical conditions. Large-scale sea ice model simulations also suggest a context of increasingly deep snow, warm ice, and large brine fractions across the three observational years, despite the fact that the model is forced with a snowfall climatology. This lends support to the claim that more severe Antarctic sea ice conditions, characterized by a longer ice season, thicker, and more concentrated ice are sufficient to increase the snow depth and, somehow counterintuitively, to warm the ice.

  11. Organic iodine in Antarctic sea ice: A comparison between winter in the Weddell Sea and summer in the Amundsen Sea

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    Granfors, Anna; Ahnoff, Martin; Mills, Matthew M.; Abrahamsson, Katarina

    2014-12-01

    Recent studies have recognized sea ice as a source of reactive iodine to the Antarctic boundary layer. Volatile iodinated compounds (iodocarbons) are released from sea ice, and they have been suggested to contribute to the formation of iodine oxide (IO), which takes part in tropospheric ozone destruction in the polar spring. We measured iodocarbons (CH3I, CH2ClI, CH2BrI, and CH2I2) in sea ice, snow, brine, and air during two expeditions to Antarctica, OSO 10/11 to the Amundsen Sea during austral summer and ANT XXIX/6 to the Weddell Sea in austral winter. These are the first reported measurements of iodocarbons from the Antarctic winter. Iodocarbons were enriched in sea ice in relation to seawater in both summer and winter. During summer, the positive relationship to chlorophyll a biomass indicated a biological origin. We suggest that CH3I is formed biotically in sea ice during both summer and winter. For CH2ClI, CH2BrI, and CH2I2, an additional abiotic source at the snow/ice interface in winter is suggested. Elevated air concentrations of CH3I and CH2ClI during winter indicate that they are enriched in lower troposphere and may take part in the formation of IO at polar sunrise.

  12. Interannual controls on Weddell Sea surface water fCO2 during the autumn–winter transition phase

    NARCIS (Netherlands)

    Bellerby, Richard G.J.; Hoppema, Mario; Fahrbach, Eberhard; Baar, Hein J.W. de; Stoll, Michel H.C.

    2004-01-01

    The fugacity of carbon dioxide (fCO2) of the surface waters of the Weddell Sea along the prime meridian has been described for the austral autumn in 1996 and 1998. For individual years, fCO2 has a strong linear relationship with sea surface temperature, although the relationships cannot be

  13. Effects of hydrographic variability on the spatial, seasonal and diel diving patterns of southern elephant seals in the eastern Weddell Sea.

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    Martin Biuw

    2010-11-01

    Full Text Available Weddell Sea hydrography and circulation is driven by influx of Circumpolar Deep Water (CDW from the Antarctic Circumpolar Current (ACC at its eastern margin. Entrainment and upwelling of this high-nutrient, oxygen-depleted water mass within the Weddell Gyre also supports the mesopelagic ecosystem within the gyre and the rich benthic community along the Antarctic shelf. We used Conductivity-Temperature-Depth Satellite Relay Data Loggers (CTD-SRDLs to examine the importance of hydrographic variability, ice cover and season on the movements and diving behavior of southern elephant seals in the eastern Weddell Sea region during their overwinter feeding trips from Bouvetøya. We developed a model describing diving depth as a function of local time of day to account for diel variation in diving behavior. Seals feeding in pelagic ice-free waters during the summer months displayed clear diel variation, with daytime dives reaching 500-1500 m and night-time targeting of the subsurface temperature and salinity maxima characteristic of CDW around 150-300 meters. This pattern was especially clear in the Weddell Cold and Warm Regimes within the gyre, occurred in the ACC, but was absent at the Dronning Maud Land shelf region where seals fed benthically. Diel variation was almost absent in pelagic feeding areas covered by winter sea ice, where seals targeted deep layers around 500-700 meters. Thus, elephant seals appear to switch between feeding strategies when moving between oceanic regimes or in response to seasonal environmental conditions. While they are on the shelf, they exploit the locally-rich benthic ecosystem, while diel patterns in pelagic waters in summer are probably a response to strong vertical migration patterns within the copepod-based pelagic food web. Behavioral flexibility that permits such switching between different feeding strategies may have important consequences regarding the potential for southern elephant seals to adapt to

  14. On the outflow of dense water from the Weddell and Ross Seas in OCCAM model

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    R. Kerr

    2012-06-01

    Full Text Available We describe the seasonal and interannual variability of volume transports in the Weddell and Ross Seas using the 1/12° 20-yr simulation of the OCCAM global ocean general circulation model. The average simulated full-depth cumulative volume transports were 28.5 ± 2.9 Sv (1 Sv ≡ 106 m3 s−1 and 13.4 ± 5.2 Sv, across the main export regions of the Weddell and Ross Seas, respectively. The values of mean outflow of Antarctic Bottom Water (AABW (defined by neutral density γn ≥ 28.27 kg m−3 from the Weddell and Ross Seas of 10.6 ± 3.1 Sv and 0.5 ± 0.7 Sv, respectively, agree with the range reported in historical observational studies. The export of Weddell Sea dense water in OCCAM is primarily determined by the strength of the Weddell Gyre. Variability in AABW export is predominantly at periods of ~1 yr and 2–4 yr.

  15. A dynamically consistent analysis of circulation and transports in the southwestern Weddell Sea

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    M. Yaremchuk

    1998-08-01

    Full Text Available An inverse model is applied for the analysis of hydrographic and current meter data collected on the repeat WOCE section SR4 in the Weddell Sea in 1989–1992. The section crosses the Weddell Sea cyclonic gyre from Kapp Norvegia to the northern end of the Antarctic Peninsula. The concepts of geostrophy, conservation of planetary vorticity and hydrostatics are combined with advective balances of active and passive properties to provide a dynamically consistent circulation pattern. Our variational assimilation scheme allows the calculation of three-dimensional velocities in the section plane. Current speeds are small except along the coasts where they reach up to 12 cm/s. We diagnose a gyre transport of 34 Sverdrup which is associated with a poleward heat transport of 28×1012 W corresponding to an average heat flux of 15 Wm–2 in the Weddell Sea south of the transect. This exceeds the estimated local flux on the transect of 2 Wm–2. As the transect is located mostly in the open ocean, we conclude that the shelf areas contribute significantly to the ocean-atmosphere exchange and are consequently key areas for the contribution of the Weddell Sea to global ocean ventilation. Conversion of water masses occuring south of the section transform 6.6±1.1 Sv of the inflowing warm deep water into approximately equal amounts of Weddell Sea deep water and Weddell Sea bottom water. The volume transport of surface water equals in the in- and outflow. This means that almost all newly formed surface water is involved in the deep and bottom water formation. Comparison with the results obtained by pure velocity interpolation combined with a hydrographic data subset indicates major differences in the derived salt transports and the water mass conversion of the surface water. The differences can be explained by deviations in the structure of the upper ocean currents to which shelf areas contribute significantly. Additionally a rigorous variance analysis is

  16. On the freshening of the northwestern Weddell Sea continental shelf

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    H. H. Hellmer

    2011-05-01

    Full Text Available We analyzed hydrographic data from the northwestern Weddell Sea continental shelf of the three austral winters 1989, 1997, and 2006 and two summers following the last winter cruise. During summer a thermal front exists at ~64° S separating cold southern waters from warm northern waters that have similar characteristics as the deep waters of the central basin of the Bransfield Strait. In winter, the whole continental shelf exhibits southern characteristics with high Neon (Ne concentrations, indicating a significant input of glacial melt water. The comparison of the winter data from the shallow shelf off the tip of the Antarctic Peninsula, spanning a period of 17 yr, shows a salinity decrease of 0.09 for the whole water column, which has a residence time of <1 yr. We interpret this freshening as being caused by a combination of reduced salt input due to a southward sea ice retreat and higher precipitation during the late 20th century on the western Weddell Sea continental shelf. However, less salinification might also result from a delicate interplay between enhanced salt input due to sea ice formation in coastal areas formerly occupied by Larsen A and B ice shelves and increased Larsen C ice loss.

  17. Southern Ocean deep convection in global climate models: A driver for variability of subpolar gyres and Drake Passage transport on decadal timescales

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    Behrens, Erik; Rickard, Graham; Morgenstern, Olaf; Martin, Torge; Osprey, Annette; Joshi, Manoj

    2016-06-01

    We investigate the individual and joint decadal variability of Southern Ocean state quantities, such as the strength of the Ross and Weddell Gyres, Drake Passage transport, and sea ice area, using the National Institute of Water and Atmospheric Research UK Chemistry and Aerosols (NIWA-UKCA) model and CMIP5 models. Variability in these quantities is stimulated by strong deep reaching convective events in the Southern Ocean, which produce an Antarctic Bottom Water-like water mass and affect the large-scale meridional density structure in the Southern Ocean. An increase in the (near) surface stratification, due to freshwater forcing, can be a precondition for subsequent strong convection activity. The combination of enhanced-gyre driven sea ice and freshwater export, as well as ongoing subsurface heat accumulation, lead to a time lag between changes in oceanic freshwater and heat content. This causes an ongoing weakening of the stratification until sudden strong mixing events emerge and the heat is released to the atmosphere. We find that strong convection reduces sea ice cover, weakens the subpolar gyres, increases the meridional density gradient and subsequently results in a positive Drake Passage transport anomaly. Results of available CMIP5 models confirm that variability in sea ice, Drake Passage transport, and the Weddell Gyre strength is enhanced if models show strong open ocean convective events. Consistent relationships between convection, sea ice, Drake Passage transport, and Ross Gyre strength variability are evident in most models, whether or not they host open ocean convection.

  18. Weddell Sea Export Pathways from Surface Drifters

    OpenAIRE

    Youngs, Madeleine K.; Thompson, Andrew F.; Flexas, M. Mar; Heywood, Karen J.

    2015-01-01

    The complex export pathways that connect the surface waters of the Weddell Sea with the Antarctic Circumpolar Current influence water mass modification, nutrient fluxes, and ecosystem dynamics. To study this exchange, 40 surface drifters, equipped with temperature sensors, were released into the northwestern Weddell Sea’s continental shelf and slope frontal system in late January 2012. Comparison of the drifter trajectories with a similar deployment in early February 2007 provides insight int...

  19. A dynamically consistent analysis of circulation and transports in the southwestern Weddell Sea

    Directory of Open Access Journals (Sweden)

    M. Yaremchuk

    Full Text Available An inverse model is applied for the analysis of hydrographic and current meter data collected on the repeat WOCE section SR4 in the Weddell Sea in 1989–1992. The section crosses the Weddell Sea cyclonic gyre from Kapp Norvegia to the northern end of the Antarctic Peninsula. The concepts of geostrophy, conservation of planetary vorticity and hydrostatics are combined with advective balances of active and passive properties to provide a dynamically consistent circulation pattern. Our variational assimilation scheme allows the calculation of three-dimensional velocities in the section plane. Current speeds are small except along the coasts where they reach up to 12 cm/s. We diagnose a gyre transport of 34 Sverdrup which is associated with a poleward heat transport of 28×1012 W corresponding to an average heat flux of 15 Wm–2 in the Weddell Sea south of the transect. This exceeds the estimated local flux on the transect of 2 Wm–2. As the transect is located mostly in the open ocean, we conclude that the shelf areas contribute significantly to the ocean-atmosphere exchange and are consequently key areas for the contribution of the Weddell Sea to global ocean ventilation. Conversion of water masses occuring south of the section transform 6.6±1.1 Sv of the inflowing warm deep water into approximately equal amounts of Weddell Sea deep water and Weddell Sea bottom water. The volume transport of surface water equals in the in- and outflow. This means that almost all newly formed surface water is involved in the deep and bottom water formation. Comparison with the results obtained by pure velocity interpolation combined with a hydrographic data subset indicates major differences in the derived salt transports and the water mass conversion of the surface water. The differences can be explained by deviations in the structure of the upper ocean currents to which shelf areas contribute significantly. Additionally a

  20. Quantification of sea ice production in Weddell Sea polynyas

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    Zentek, Rolf; Heinemann, Günther; Paul, Stephan; Stulic, Lukrecia; Timmermann, Ralph

    2017-04-01

    The regional climate model COSMO-CLM was used to perform simulations the Weddell Sea region in Antarctica for the time period 2002-2015 with the focus on atmosphere-ocean-sea ice interactions. The original model was adapted to polar regions by the use of a thermodynamic sea ice module with snow cover and an temperature-dependent albedo scheme for sea ice. The recently published topography RTopo2 was used. The model was run with nesting in ERA-Interim data in a forecast mode. Sea ice concentrations were taken from satellite measurements (AMSR-E, SSMI/S, AMSR2) and were updated daily to allow for a close-to-reality hindcast. Simulations were done with 15 km resolution for the whole period 2002-2015 with the goal to force the sea-ice ocean model FESOM. In a second step a 5 km simulation was one-way nested for the winter period (April - September) 2002-2015 to allow for a better quantification of sea ice production in the Weddell Sea. Estimates of sea ice production and comparisons of the results to remote sensing data will be presented.

  1. Diverse papillomaviruses identified in Weddell seals.

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    Smeele, Zoe E; Burns, Jennifer M; Van Doorsaler, Koenraad; Fontenele, Rafaela S; Waits, Kara; Stainton, Daisy; Shero, Michelle R; Beltran, Roxanne S; Kirkham, Amy L; Berngartt, Rachel; Kraberger, Simona; Varsani, Arvind

    2018-04-01

    Papillomaviridae is a diverse family of circular, double-stranded DNA (dsDNA) viruses that infect a broad range of mammalian, avian and fish hosts. While papillomaviruses have been characterized most extensively in humans, the study of non-human papillomaviruses has contributed greatly to our understanding of their pathogenicity and evolution. Using high-throughput sequencing approaches, we identified 7 novel papillomaviruses from vaginal swabs collected from 81 adult female Weddell seals (Leptonychotes weddellii) in the Ross Sea of Antarctica between 2014-2017. These seven papillomavirus genomes were amplified from seven individual seals, and six of the seven genomes represented novel species with distinct evolutionary lineages. This highlights the diversity of papillomaviruses among the relatively small number of Weddell seal samples tested. Viruses associated with large vertebrates are poorly studied in Antarctica, and this study adds information about papillomaviruses associated with Weddell seals and contributes to our understanding of the evolutionary history of papillomaviruses.

  2. On the near-bottom variability in the northwestern Weddell Sea

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    Schröder, M.; Hellmer, H. H.; Absy, J. M.

    The thermohaline data from the first Brazilian hydrographic cruise to the northwestern Weddell Sea (AR XVIII) revealed significant near-bottom changes in water-column properties over seasonal and interannual time scales. Favorable ice conditions in 2000 allowed a dense station coverage of the area including the main pathways for Weddell Sea deep and bottom waters. The new results are compared with the data from the 1998 German cruise ANT XV/4 and other historical data. A warming of the bottom layer was discovered that was more attributable to short-term seasonal or interannual fluctuations in the formation of cold bottom water than to a long-term trend. There was both consistency and variation between and within seasons. Invariant bottom-water characteristics were observed in different seasons (summer/winter), and variable bottom-water characteristics were observed in the same season (summer) at the same locations. This reduces the possibility of a dominant seasonal effect. Instead, we propose that the intermittent behavior of small cold-water sources along the Weddell Sea's periphery causes the variability measured in the deep northwestern Weddell Sea. The observed variability has consequences for the water-mass export across the South Scotia Ridge, as the absence of the fresher/lighter Weddell Sea Bottom Water south of South Orkney Plateau during AR XVIII might be linked to a reduced ventilation of the deep Scotia Sea. The results of this study show the need for ongoing efforts for establishing a long-term monitoring of this region with global importance.

  3. Quantification of sea ice production at coastal polynyas in the southern Weddell Sea

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    Stulic, Lukrecia; Timmermann, Ralph; Zentek, Rolf; Heinemann, Günther

    2017-04-01

    Sea ice production and associated High Salinity Shelf Water (HSSW) formation in the southern Weddell Sea is an important driver for the global thermohaline ocean circulation and determines the properties of shelf water inflow that fuels ice shelf basal melting. In the southern Weddell Sea, coastal polynyas cover 1% of the area, but contribute about 10% to the total winter sea ice production. This project aims to improve estimates of the sea ice production and HSSW formation in the southern Weddell Sea coastal polynyas by a synergy of numerical simulations and remote sensing data. Sea ice-ocean simulations are performed with the Finite Element Sea ice-Ocean Model (FESOM) with a horizontal resolution close to the Rossby radius over the whole Weddell Sea to better represent eddy dynamics. In order to asses sensitivity of polynya characteristics and HSSW formation rates to the atmospheric forcing, FESOM is forced with different reanalysis data (ERA-Interim, NCEP-CFSR). Mean sea ice growth for the simulated period (1979-2012) is lower and more localized along the coastline/ice shelf front in the NCEP-CFSR run. Differences may be attributed to the colder air temperatures and stronger offshore winds in ERA-Interim forcing. FESOM will be forced with output from the regional atmospheric model COSMO-CLM (CCLM) to further investigate sensitivity with respect to different atmospheric forcing. The best and most realistic ice production and HSSW formation estimates are expected to be obtained by assimilation of thin ice thickness data derived from MODIS retrievals into FESOM. This will lead to a high resolution data set of sea ice coverage and ice thickness fields that can be used as reference data set for other sea ice models and as an input for high-resolution atmospheric models.

  4. AWI Moored ULS Data, Weddell Sea (1990-1998)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set consists of moored Upward Looking Sonar (ULS) data from 14 stations in the Weddell Sea. Parameters in the processed data files are water pressure,...

  5. Active and Passive Microwave Determination of the Circulation and Characteristics of Weddell and Ross Sea Ice

    Science.gov (United States)

    Drinkwater, Mark R.; Liu, Xiang

    2000-01-01

    A combination of satellite microwave data sets are used in conjunction with ECMWF (Medium Range Weather Forecasts) and NCEP (National Center for Environment Prediction) meteorological analysis fields to investigate seasonal variability in the circulation and sea-ice dynamics of the Weddell and Ross Seas. Results of sea-ice tracking using SSM/I (Special Sensor Microwave Imager), Scatterometer and SAR images are combined with in-situ data derived from Argos buoys and GPS drifters to validate observed drift patterns. Seasonal 3-month climatologies of ice motion and drift speed variance illustrate the response of the sea-ice system to seasonal forcing. A melt-detection algorithm is used to track the onset of seasonal melt, and to determine the extent and duration of atmospherically-led surface melting during austral summer. Results show that wind-driven drift regulates the seasonal distribution and characteristics of sea-ice and the intensity of the cyclonic Gyre circulation in these two regions.

  6. Sea ice draft in the Weddell Sea, measured by upward looking sonars

    Directory of Open Access Journals (Sweden)

    A. Behrendt

    2013-06-01

    Full Text Available The presented database contains time-referenced sea ice draft values from upward looking sonar (ULS measurements in the Weddell Sea, Antarctica. The sea ice draft data can be used to infer the thickness of the ice. They were collected during the period 1990–2008. In total, the database includes measurements from 13 locations in the Weddell Sea and was generated from more than 3.7 million measurements of sea ice draft. The files contain uncorrected raw drafts, corrected drafts and the basic parameters measured by the ULS. The measurement principle, the data processing procedure and the quality control are described in detail. To account for the unknown speed of sound in the water column above the ULS, two correction methods were applied to the draft data. The first method is based on defining a reference level from the identification of open water leads. The second method uses a model of sound speed in the oceanic mixed layer and is applied to ice draft in austral winter. Both methods are discussed and their accuracy is estimated. Finally, selected results of the processing are presented. The data can be downloaded from doi:10.1594/PANGAEA.785565.

  7. Physical nutrient transport in the North Atlantic Subtropical Gyre

    Science.gov (United States)

    Jenkins, W.; Lott, D. E.

    2009-04-01

    Use of the helium-3 flux gauge to estimate the physically mediated flux of new nutrients to the euphotic zone of the North Atlantic subtropical gyre broadly suggests a pathway whereby inorganic nutrients that have been remineralized within the main thermocline may be returned to the seasonally accessible layer in the Sargasso Sea: the so-called "Nutrient Spiral" (Jenkins and Doney (2003), Glob. Biog. Cyc., 17(4), doi:1110.1029/2003GB002085.) The challenge, however, is identifying the exact mechanism whereby this occurs. One possible process is that of "obduction", whereby the combination of strong advection and rapidly deepening winter mixed layers result in the effective outcropping of substantial amounts of thermocline nutrients and tritiugenic helium-3. We present here a quantitative estimate based on hydrographic sections and geostrophic transports of the fluxes and transformations of both tritugenic helium-3 and nitrate within the basin, and attempt to relate these estimates to the specific shallow-water behaviors of these tracers, and their global and regional physical transports. An important constraint for these estimates lies in the evolving distributions of the transient tracers tritium and helium-3. We compare these results with other tracer-based estimates of new, net-community, and export production.

  8. Decadal changes in salinity in the oceanic subtropical gyres

    Science.gov (United States)

    Melzer, Bryce A.; Subrahmanyam, Bulusu

    2017-01-01

    We analyzed spatial and temporal salinity trends in five subtropical gyre regions over the past six decades using Simple Ocean Data Assimilation (SODA) reanalysis with a focus on the subsurface salinity of the upper 1000 m of the ocean. Our results indicate an overall salinity increase within the mixed layer, and a salinity decrease at depths greater than 200 m in the global subtropical gyres over 61 years, of which each individual gyre was analyzed in further detail. We determine that freshwater fluxes at the air-sea interface are the primary drivers of the sea surface salinity (SSS) signature over these open ocean regions by quantifying the advective contribution within the surface layer. This was demonstrated through a mixed layer salinity budget in each subtropical gyre based on the vertically integrated advection and entrainment of salt. Our analysis of decadal variability of fluxes into and out of the gyres reveals little change in the strength of the mean currents through this region despite an increase in the annual export of salt in all subtropical gyres, with the meridional component dominating the zonal. This study reveals that the salt content of E-P maximum waters advected into the subtropical gyres is increasing over time. A combination of increasing direct evaporation over the regions with increasing remote evaporation over nearby E-P maxima is believed to be the main driver in increasing salinity of the subtropical oceans, suggesting an intensification of the global water cycle over decadal time scales.

  9. Katabatic winds and polynya dynamics in the Weddell Sea region (Antarctica)

    Science.gov (United States)

    Heinemann, Günther; Ebner, Lars; Haid, Verena; Timmermann, Ralph

    2013-04-01

    The Antarctic surface wind field is dominated by a persistent katabatic flow from the interior towards the coast. Downslope winds are a result of mainly two forcing components: (1) the katabatic force (KF), which contains the forcing from a temperature inversion over sloping terrain and (2) the synoptic force (SF), which is the superimposed pressure gradient force in the free atmosphere above the inversion layer. If the slope ends close to the coastline and/or if appropriate synoptic forcing is present, wind of katabatic origin can contribute to the formation of coastal polynyas. These coastal polynyas are frequent in the Weddell Sea Region even in winter and have a strong impact on ice-ocean-atmosphere interactions. Through the enhanced energy exchange between ocean and atmosphere, these areas are known as strong sea ice producers. In consequence, polynyas have a substantial impact on bottom water formation through the production of new cold and saline water masses during the whole winter season. To investigate the polynya dynamics associated with katabatic winds, high-resolution (5km) atmospheric simulations have been performed for 6 months for the Weddell Sea Region, comprising the autumn and winter season in 2008. The simulations have been carried out using the non-hydrostatic numerical weather prediction model COSMO (Consortium for Small-scale modeling) of the DWD (German Meteorological Service) using GME (Global model extended) analysis from DWD as initial and boundary fields. Daily sea ice coverage is taken from AMSR-E (Advanced Microwave Scanning Radiometer - EOS) data. A thermodynamic sea ice model is used to simulate the sea ice surface temperatures in the COSMO model. This high-resolution atmospheric dataset was then provided for forcing the sea ice ocean model FESOM (Finite element sea ice ocean model). Linkages between pressure gradient force, composed of its katabatic and synoptic components, offshore wind regimes and polynya area are identified. The

  10. Carbonate Chemistry of the Weddell Sea from 10/9/1981 - 11/25/1981 (NODC Accession 0000121)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Carbonate data for the Weddell sea are provided from both surface samples taken along the cruise track of the US-USSR Weddell Polynya Expedition (WEPOLEX-81) and...

  11. Dissolved Fe across the Weddell Sea and Drake Passage: impact of DFe on nutrient uptake

    NARCIS (Netherlands)

    Klunder, M.B.; Laan, P.; de Baar, H.J.W.; Middag, R.; Neven, I.; Van Ooijen, J.

    2014-01-01

    This manuscript reports the first full depth distributions of dissolved iron (DFe) over a high-resolution Weddell Sea and Drake Passage transect. Very low dissolved DFe concentrations (0.01-0.1 nM range) were observed in the surface waters of the Weddell Sea, and within the Drake Passage polar

  12. Dissolved Fe across the Weddell Sea and Drake Passage : Impact of DFe on nutrient uptake

    NARCIS (Netherlands)

    Klunder, M. B.; Laan, P.; De Baar, H. J. W.; Middag, R.; Neven, I.; Van Ooijen, J.

    2014-01-01

    This manuscript reports the first full depth distributions of dissolved iron (DFe) over a high-resolution Weddell Sea and Drake Passage transect. Very low dissolved DFe concentrations (0.01-0.1 nM range) were observed in the surface waters of the Weddell Sea, and within the Drake Passage polar

  13. Albedo of the ice covered Weddell and Bellingshausen Seas

    OpenAIRE

    Weiss, A. I.; King, J. C.; Lachlan-Cope, T. A.; Ladkin, R. S.

    2012-01-01

    This study investigates the surface albedo of the sea ice areas adjacent to the Antarctic Peninsula during the austral summer. Aircraft measurements of the surface albedo, which were conducted in the sea ice areas of the Weddell and Bellingshausen Seas show significant differences between these two regions. The averaged surface albedo varied between 0.13 and 0.81. The ice cover of the Bellingshausen Sea consisted mainly of first year ice and the sea surface showed an averaged sea ice albedo o...

  14. Interannual variability of the thermohaline structure in the convective gyre of the Greenland Sea

    Science.gov (United States)

    Alekseev, G. V.; Ivanov, V. V.; Korablev, A. A.

    The temporal variability of thermohaline conditions in the Greenland Sea Convective gyre is examined on the basis of the long term observational series. The existence of two stable types of winter thermohaline structure is discovered. The transition from one type to another occurs through the pre-convective state and consequent convection. The characteristic feature ofthe pre-convective state is an increased (about 0.07 PSU above normal) surface salinity, caused by the external salt water influx. Potential temperature and salinity time series joint analysis confirms the crucial role of the surface salinity in the convection realization. An explanation of the surface to bottom overturning events and of the low frequency variability of convection activity is suggested on this basis.

  15. East Weddell Sea echinoids from the JR275 expedition

    Directory of Open Access Journals (Sweden)

    Thomas Saucède

    2015-05-01

    Full Text Available Information regarding the echinoids in this dataset is based on the Agassiz Trawl (AGT and epibenthic sledge (EBS samples collected during the British Antarctic Survey cruise JR275 on the RRS James Clark Ross in the austral summer 2012. A total of 56 (1 at the South Orkneys and 55 in the Eastern Weddell Sea Agassiz Trawl and 18 (2 at the South Orkneys and 16 in the Eastern Weddell Sea epibenthic sledge deployments were performed at depths ranging from ~280 to ~2060 m. This presents a unique collection for the Antarctic benthic biodiversity assessment of an important group of benthic invertebrates. In total 487 specimens belonging to six families, 15 genera, and 22 morphospecies were collected. The species richness per station varied between one and six. Total species richness represents 27% of the 82 echinoid species ever recorded in the Southern Ocean (David et al. 2005b, Pierrat et al. 2012, Saucède et al. 2014. The Cidaridae (sub-family Ctenocidarinae and Schizasteridae are the two most speciose families in the dataset. They comprise seven and nine species respectively. This is illustrative of the overall pattern of echinoid diversity in the Southern Ocean where 65% of Antarctic species belong to the families Schizasteridae and Cidaridae (Pierrat et al. 2012.

  16. Influence of the Atlantic subpolar gyre on the thermohaline circulation.

    Science.gov (United States)

    Hátún, Hjálmar; Sandø, Anne Britt; Drange, Helge; Hansen, Bogi; Valdimarsson, Hedinn

    2005-09-16

    During the past decade, record-high salinities have been observed in the Atlantic Inflow to the Nordic Seas and the Arctic Ocean, which feeds the North Atlantic thermohaline circulation (THC). This may counteract the observed long-term increase in freshwater supply to the area and tend to stabilize the North Atlantic THC. Here we show that the salinity of the Atlantic Inflow is tightly linked to the dynamics of the North Atlantic subpolar gyre circulation. Therefore, when assessing the future of the North Atlantic THC, it is essential that the dynamics of the subpolar gyre and its influence on the salinity are taken into account.

  17. Marine birds and mammals of the Pacific Subarctic Gyres

    Science.gov (United States)

    Springer, A.M.; Piatt, John F.; Shuntov, V.P.; Van Vliet, Gus B.; Vladimirov, V.L.; Kuzin, A.E.; Perlov, A.S.

    1999-01-01

    The importance of the subarctic gyres of the North Pacific Ocean to marine birds and mammals is poorly known because of a paucity of data spanning appropriate scales of time and space. The little information that is available indicates the western subarctic gyre (WSAG) is more productive than the eastern subarctic gyre (ESAG). In summer the WSAG supports a greater density and higher biomass of seabirds than the ESAG, including at least two species that are more abundant at nesting colonies in the eastern subarctic. Perhaps most revealing of the seabird distributions in this regard is that of southern hemisphere shearwaters (Puffinus spp.) that overwinter in the North Pacific. Their biomass is an order of magnitude greater than that of any northern hemisphere species and is three-fold greater in the WSAG than in the ESAG. Several species of cetaceans also appear to be, or to have been prior to commercial depletions, more abundant in the WSA. Among the many prey species consumed by marine birds and mammals, squids and fishes in the family Myctophidae predominate overall. Other forage species, notably euphausiids, Pacific saury (Cololabis saira) and Atka mackerel (Pleurogrammus monopterygius) are important at times to certain species. The principal exceptions to this generalization are baleen whales and small seabirds that consume zooplankton. Interannual and decadal-scale variability in the physical environment and food web production affect seabirds and marine mammals at sea and at coastal breeding locations around the margins of the gyres.

  18. AWI Moored ULS Data, Weddell Sea (1990-1998), Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set consists of moored Upward Looking Sonar (ULS) data from 14 stations in the Weddell Sea. Parameters in the processed data files are water pressure,...

  19. Studies of deep water formation and circulation in the Weddell Sea using natural and anthropogenic tracers

    International Nuclear Information System (INIS)

    Schlosser, Peter; Bayer, Reinhold

    1991-01-01

    The application of natural and anthropogenic trace substances in oceanographic studies of the Weddell Sea is reviewed. The potential of some steady-state and transient tracers (tritium, CFC-11 and CFC-12, 18 O, and helium isotopes) for studies of deep water formation and circulation is discussed on the basis of data sets collected mainly on cruises of R/V 'Polastern' to the Weddell Sea during the 1980s. CFC/ tritium ratio dating of young water masses is applied to estimate mean age and transit times of water involved in Weddell Sea Bottom Water formation. The history of the CFC-11/tritium ratio through time is derived for Weddell Sea shelf waters. (author). 36 refs.; 18 figs

  20. Multichannel Seismic Reflection Data - SCAR - Weddell Sea - 1978, SDLS CD-ROM vol 17

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are stacked multichannel marine seismic reflection data recorded during 1978 in the Weddell Sea and Queen Maud Land, Antarctica, by the Bundesanstalt fur...

  1. Benthic community productivity in the Magellan Region and in the Weddell Sea

    Directory of Open Access Journals (Sweden)

    Thomas Brey

    1999-12-01

    Full Text Available Our comparison of macrobenthic biomass, production and productivity of the Magellan region (14 - 349 m water depth and the Weddell Sea (132 - 548 m water depth is based on multi box corer samples collected in both areas. Biomass is slightly but not significantly lower in the Magellan region (7.3 g C m-2 than in the Weddell Sea (12.0 g C m-2. Annual production and P/B ratio are higher in the Magellan region (5.1 g C m-2 y-1, 0.7 y-1 as compared to the Weddell Sea (3.6 g C m-2 y-1, 0.3 y-1. In the Magellan region, Mollusca, Polychaeta and Arthropoda dominate benthic production, whereas in the Weddell Sea Polychaeta, Porifera and Echinodermata are the most productive taxa.

  2. Long-term coastal-polynya dynamics in the southern Weddell Sea from MODIS thermal-infrared imagery

    Science.gov (United States)

    Paul, S.; Willmes, S.; Heinemann, G.

    2015-11-01

    Based upon thermal-infrared satellite imagery in combination with ERA-Interim atmospheric reanalysis data, we derive long-term polynya characteristics such as polynya area, thin-ice thickness distribution, and ice-production rates for a 13-year investigation period (2002-2014) for the austral winter (1 April to 30 September) in the Antarctic southern Weddell Sea. All polynya parameters are derived from daily cloud-cover corrected thin-ice thickness composites. The focus lies on coastal polynyas which are important hot spots for new-ice formation, bottom-water formation, and heat/moisture release into the atmosphere. MODIS has the capability to resolve even very narrow coastal polynyas. Its major disadvantage is the sensor limitation due to cloud cover. We make use of a newly developed and adapted spatial feature reconstruction scheme to account for cloud-covered areas. We find the sea-ice areas in front of the Ronne and Brunt ice shelves to be the most active with an annual average polynya area of 3018 ± 1298 and 3516 ± 1420 km2 as well as an accumulated volume ice production of 31 ± 13 and 31 ± 12 km3, respectively. For the remaining four regions, estimates amount to 421 ± 294 km2 and 4 ± 3 km3 (Antarctic Peninsula), 1148 ± 432 km2 and 12 ± 5 km3 (iceberg A23A), 901 ± 703 km2 and 10 ± 8 km3 (Filchner Ice Shelf), as well as 499 ± 277 km2 and 5 ± 2 km3 (Coats Land). Our findings are discussed in comparison to recent studies based on coupled sea-ice/ocean models and passive-microwave satellite imagery, each investigating different parts of the southern Weddell Sea.

  3. Atmospheric Response to Weddell Sea Open-Ocean Polynya

    Energy Technology Data Exchange (ETDEWEB)

    Hodos, Travis [United States Air Force Academy, Colorado Springs, CO (United States); Weijer, Wilbert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-07-02

    The atmospheric conditions associated with the rare Weddell Sea open ocean polynya are investigated. The polynya has not been seen since 1976, so data on the event is scarce. The CESM high resolution model is used to investigate multiple atmospheric variables. We analyze three years of polynyas, which are also compared to three years without a polynya. The surface temperature, sensible heat flux, latent heat flux, humidity, average wind speed, precipitation, longwave flux, and shortwave flux all increased over the polynya. The sensible heat flux had a higher magnitude than the latent heat flux because conduction and convection were the primary drivers of heat flux. A combination of increased latent heat flux and humidity led to an increase in precipitation. Increased longwave downwelling flux over the polynya indicated the presence of clouds over the polynya. Lastly, the sea level pressure was consistently lower over the polynya because of the presence of a thermal low generated by thermally driven convective updrafts.

  4. Antarctophthirus carlinii (Anoplura: Echinophthiriidae), a new species from the Weddell seal Leptonychotes weddelli.

    Science.gov (United States)

    Leonardi, María Soledad; Poljak, Sebastián; Carlini, Pedro; Galliari, Juan; Bobinac, Magalí; Santos, Mercedes; Márquez, María E; Negrete, Javier

    2014-11-01

    As a part of an ongoing long-term study on the biology of pack-ice seals in Antarctica, we had the opportunity to collect lice from Weddell seals (Leptonychotes weddelli). We did not find the original description of this host-parasite association. Antarctophthirus ogmorhini had previously been reported as a parasite for the Weddell seal, but the information is, to a certain extent, confusing. During the development of the present study, we had access to literature concerning the presence of A. ogmorhini on this host, which, to our knowledge, was not determined in any of the previous works on this species. We compared lice collected from Weddell seals with A. ogmorhini obtained from the type host, the leopard seal (Hydrurga leptonyx), and we found that both species can be distinguished. The main differences are the characteristic pattern of chaetotaxy in the dorsal side of the head in lice from Weddell seals, the size and form of the pseudopenis, and the distribution and size of the fringe of setae surrounding the genital opening. Considering the conservative morphology, and ecological and evolutionary features of sucking lice, we proposed that lice from Weddell seals constitute a new species. In the present work, we described and illustrated adults of this new species collected from Weddell seals during the austral summer of 2014 at the Danco Coast, Antarctic Peninsula.

  5. Seabirds, gyres and global trends in plastic pollution

    International Nuclear Information System (INIS)

    Franeker, Jan A. van; Law, Kara Lavender

    2015-01-01

    Fulmars are effective biological indicators of the abundance of floating plastic marine debris. Long-term data reveal high plastic abundance in the southern North Sea, gradually decreasing to the north at increasing distance from population centres, with lowest levels in high-arctic waters. Since the 1980s, pre-production plastic pellets in North Sea fulmars have decreased by ∼75%, while user plastics varied without a strong overall change. Similar trends were found in net-collected floating plastic debris in the North Atlantic subtropical gyre, with a ∼75% decrease in plastic pellets and no obvious trend in user plastic. The decreases in pellets suggest that changes in litter input are rapidly visible in the environment not only close to presumed sources, but also far from land. Floating plastic debris is rapidly “lost” from the ocean surface to other as-yet undetermined sinks in the marine environment. - Highlights: • Seabirds are effective biological monitors of floating plastic marine debris. • Plastics in fulmar stomachs and in the North Atlantic gyre show similar trends. • Pre-production plastic pellets show strong decreases in fulmars and in the gyre. • These data show that floating plastics rapidly disappear from the ocean surface. - Long term studies give evidence that reduced input of plastic debris into the ocean becomes rapidly visible. Floating plastics disappear to as-yet undetermined sinks

  6. Importance of Ekman transport and gyre circulation change on seasonal variation of surface dissolved iron in the western subarctic North Pacific

    Science.gov (United States)

    Nakanowatari, Takuya; Nakamura, Tomohiro; Uchimoto, Keisuke; Nishioka, Jun; Mitsudera, Humio; Wakatsuchi, Masaaki

    2017-05-01

    Iron (Fe) is an essential nutrient for marine phytoplankton and it constitutes an important element in the marine carbon cycle in the ocean. This study examined the mechanisms controlling seasonal variation of dissolved Fe (dFe) in the western subarctic North Pacific (WSNP), using an ocean general circulation model coupled with a simple biogeochemical model incorporating a dFe cycle fed by two major sources (atmospheric dust and continental shelf sediment). The model reproduced the seasonal cycle of observed concentrations of dFe and macronutrients at the surface in the Oyashio region with maxima in winter (February-March) and minima in summer (July-September), although the simulated seasonal amplitudes are a half of the observed values. Analysis of the mixed-layer dFe budget indicated that both local vertical entrainment and lateral advection are primary contributors to the wintertime increase in dFe concentration. In early winter, strengthened northwesterly winds excite southward Ekman transport and Ekman upwelling over the western subarctic gyre, transporting dFe-rich water southward. In mid to late winter, the southward western boundary current of the subarctic gyre and the outflow from the Sea of Okhotsk also bring dFe-rich water to the Oyashio region. The contribution of atmospheric dust to the dFe budget is several times smaller than these ocean transport processes in winter. These results suggest that the westerly wind-induced Ekman transport and gyre circulation systematically influence the seasonal cycle of WSNP surface dFe concentration.

  7. Winter Weather

    Science.gov (United States)

    ... Education Centers Harwood Training Grants Videos E-Tools Winter Storms Plan. Equip. Train To prevent injuries, illnesses and Fatalities during winter storms. This page requires that javascript be enabled ...

  8. Winter MVC

    OpenAIRE

    Castellón Gadea, Pasqual

    2013-01-01

    Winter MVC és un framework de presentació basat en Spring MVC que simplifica la metodologia de configuracions. Winter MVC es un framework de presentación basado en Spring MVC que simplifica la metodología de configuraciones. Winter MVC is a presentation framework that simplifies Spring MVC configuration methodology.

  9. The western boundary current of the seasonal subtropical gyre in the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Shetye, S.R.; Gouveia, A.D.; Shenoi, S.S.C.; Sundar, D.; Michael, G.S.; Nampoothiri, G.

    , and monthly mean wind stress, we propose that the poleward current is the western boundary current of a seasonal anticyclonic subtropical gyre which forms in the Bay during January, is best developed during March-April, and decays by June. The gyre...

  10. The plastic-associated microorganisms of the North Pacific Gyre

    International Nuclear Information System (INIS)

    Carson, Henry S.; Nerheim, Magnus S.; Carroll, Katherine A.; Eriksen, Marcus

    2013-01-01

    Highlights: • Microorganisms mediate processes affecting the fate and impacts of marine plastic. • North Pacific Gyre (NPG) plastics were examined with scanning-electron microscopy. • Bacillus bacteria and pennate diatoms dominated the NPG plastic fouling community. • Bacterial abundance was patchily distributed but increased on foamed polystyrene. • Diatom abundance increased on rough surfaces and at sites with high plastic density. -- Abstract: Microorganisms likely mediate processes affecting the fate and impacts of marine plastic pollution, including degradation, chemical adsorption, and colonization or ingestion by macroorganisms. We investigated the relationship between plastic-associated microorganism communities and factors such as location, temperature, salinity, plankton abundance, plastic concentration, item size, surface roughness, and polymer type. Small plastic items from the surface of the North Pacific Gyre in 2011 were examined using scanning electron microscopy. Bacillus bacteria (mean 1664 ± 247 individuals mm −2 ) and pennate diatoms (1097 ± 154 mm −2 ) were most abundant, with coccoid bacteria, centric diatoms, dinoflagellates, coccolithophores, and radiolarians present. Bacterial abundance was patchy, but increased on foamed polystyrene. Diatom abundance increased on items with rough surfaces and at sites with high plastic concentrations. Morphotype richness increased slightly on larger fragments, and a biogeographic transition occurred between pennate diatom groups. Better characterizing this community will aid in understanding how it interacts with plastic pollution

  11. Distributed allocation of mobile sensing swarms in gyre flows

    Directory of Open Access Journals (Sweden)

    K. Mallory

    2013-09-01

    Full Text Available We address the synthesis of distributed control policies to enable a swarm of homogeneous mobile sensors to maintain a desired spatial distribution in a geophysical flow environment, or workspace. In this article, we assume the mobile sensors (or robots have a "map" of the environment denoting the locations of the Lagrangian coherent structures or LCS boundaries. Using this information, we design agent-level hybrid control policies that leverage the surrounding fluid dynamics and inherent environmental noise to enable the team to maintain a desired distribution in the workspace. We discuss the stability properties of the ensemble dynamics of the distributed control policies. Since realistic quasi-geostrophic ocean models predict double-gyre flow solutions, we use a wind-driven multi-gyre flow model to verify the feasibility of the proposed distributed control strategy and compare the proposed control strategy with a baseline deterministic allocation strategy. Lastly, we validate the control strategy using actual flow data obtained by our coherent structure experimental testbed.

  12. Distributed allocation of mobile sensing swarms in gyre flows

    Science.gov (United States)

    Mallory, K.; Hsieh, M. A.; Forgoston, E.; Schwartz, I. B.

    2013-09-01

    We address the synthesis of distributed control policies to enable a swarm of homogeneous mobile sensors to maintain a desired spatial distribution in a geophysical flow environment, or workspace. In this article, we assume the mobile sensors (or robots) have a "map" of the environment denoting the locations of the Lagrangian coherent structures or LCS boundaries. Using this information, we design agent-level hybrid control policies that leverage the surrounding fluid dynamics and inherent environmental noise to enable the team to maintain a desired distribution in the workspace. We discuss the stability properties of the ensemble dynamics of the distributed control policies. Since realistic quasi-geostrophic ocean models predict double-gyre flow solutions, we use a wind-driven multi-gyre flow model to verify the feasibility of the proposed distributed control strategy and compare the proposed control strategy with a baseline deterministic allocation strategy. Lastly, we validate the control strategy using actual flow data obtained by our coherent structure experimental testbed.

  13. Temporal variation in isotopic composition and diet of Weddell seals in the western Ross Sea

    Science.gov (United States)

    Goetz, Kimberly T.; Burns, Jennifer M.; Hückstӓdt, Luis A.; Shero, Michelle R.; Costa, Daniel P.

    2017-06-01

    Weddell seals (Leptonychotes weddellii) are important predators in the Antarctic marine ecosystem, yet little is known about their diet. Previous studies have used scat and stomach content analyses to examine Weddell seal diet, however, these methods are biased towards prey with indigestible hard parts. To provide a more complete picture of their diet, we analyzed the stable isotope composition (δ13C and δ15N values) of red blood cells (RBC, n=96, representing a time scale of weeks to months) and vibrissae (n=45, representing months to a year) collected over a three year period (2010-2012). Our objectives were to (1) examine isotopic variation in relation to Weddell seal mass, sex, season, location, percent lipid, and age, and (2) quantify the contribution of prey items to overall diet. Body mass was a significant predictor of δ13C and δ15N values for both tissues, though the strength and direction of the relationship varied by year. The prey group consisting of Pleurogramma antarcticum and Trematomus newnesi was found to be an important dietary component, but its proportional contribution to Weddell seal diet varied with the timeframe represented by each tissue type [median RBC (range): 59.2% (40.2-8 1.1%); median mean vibrissae (range): 69.3% (43.9-89.6%)]. Results from mixing models ran for each seal indicate individual variation in diet. Overall, this study presents novel information on the isotopic variation and diet of Weddell seals over two time scales and provides insight into the feeding ecology of an important Antarctic predator.

  14. The plastic-associated microorganisms of the North Pacific Gyre.

    Science.gov (United States)

    Carson, Henry S; Nerheim, Magnus S; Carroll, Katherine A; Eriksen, Marcus

    2013-10-15

    Microorganisms likely mediate processes affecting the fate and impacts of marine plastic pollution, including degradation, chemical adsorption, and colonization or ingestion by macroorganisms. We investigated the relationship between plastic-associated microorganism communities and factors such as location, temperature, salinity, plankton abundance, plastic concentration, item size, surface roughness, and polymer type. Small plastic items from the surface of the North Pacific Gyre in 2011 were examined using scanning electron microscopy. Bacillus bacteria (mean 1664 ± 247 individuals mm(-2)) and pennate diatoms (1097 ± 154 mm(-2)) were most abundant, with coccoid bacteria, centric diatoms, dinoflagellates, coccolithophores, and radiolarians present. Bacterial abundance was patchy, but increased on foamed polystyrene. Diatom abundance increased on items with rough surfaces and at sites with high plastic concentrations. Morphotype richness increased slightly on larger fragments, and a biogeographic transition occurred between pennate diatom groups. Better characterizing this community will aid in understanding how it interacts with plastic pollution. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Reversed North Atlantic gyre dynamics in present and glacial climates

    Energy Technology Data Exchange (ETDEWEB)

    Montoya, Marisa [Universidad Complutense de Madrid, Ciudad Universitaria, Dpto. Astrofisica y Ciencias de la Atmosfera, Facultad de Ciencias Fisicas, Madrid (Spain); Born, Andreas [Bjerknes Centre for Climate Research, Bergen (Norway); University of Bergen, Geophysical Institute, Bergen (Norway); Levermann, Anders [Earth System Analysis, Potsdam Institute for Climate Impact Research, Potsdam (Germany); Potsdam University, Institute of Physics, Potsdam (Germany)

    2011-03-15

    The dynamics of the North Atlantic subpolar gyre (SPG) are assessed under present and glacial boundary conditions by investigating the SPG sensitivity to surface wind-stress changes in a coupled climate model. To this end, the gyre transport is decomposed in Ekman, thermohaline, and bottom transports. Surface wind-stress variations are found to play an important indirect role in SPG dynamics through their effect on water-mass densities. Our results suggest the existence of two dynamically distinct regimes of the SPG, depending on the absence or presence of deep water formation (DWF) in the Nordic Seas and a vigorous Greenland-Scotland ridge (GSR) overflow. In the first regime, the GSR overflow is weak and the SPG strength increases with wind-stress as a result of enhanced outcropping of isopycnals in the centre of the SPG. As soon as a vigorous GSR overflow is established, its associated positive density anomalies on the southern GSR slope reduce the SPG strength. This has implications for past glacial abrupt climate changes, insofar as these can be explained through latitudinal shifts in North Atlantic DWF sites and strengthening of the North Atlantic current. Regardless of the ultimate trigger, an abrupt shift of DWF into the Nordic Seas could result both in a drastic reduction of the SPG strength and a sudden reversal in its sensitivity to wind-stress variations. Our results could provide insight into changes in the horizontal ocean circulation during abrupt glacial climate changes, which have been largely neglected up to now in model studies. (orig.)

  16. Distribution, density and abundance of Antarctic ice seals off Queen Maud Land and the eastern Weddell Sea

    OpenAIRE

    Gurarie, Eliezer; Bengtson, John L.; Bester, Marthán N.; Blix, Arnoldus Schytte; Cameron, Michael; Bornemann, Horst; Nordøy, Erling S.; Plötz, Joachim; Steinhage, Daniel; Boveng, Peter

    2017-01-01

    The Antarctic Pack Ice Seal (APIS) Program was initiated in 1994 to estimate the abundance of four species of Antarctic phocids: the crabeater seal Lobodon carcinophaga , Weddell seal Leptonychotes weddellii , Ross seal Ommatophoca rossii and leopard seal Hydrurga leptonyx and to identify ecological relationships and habitat use patterns. The Atlantic sector of the Southern Ocean (the eastern sector of the Weddell Sea) was surveyed by research teams from Germany, Norway and South Africa usi...

  17. How the Subpolar gyre strength influences phytoplankton blooms dynamics in the North Atlantic

    DEFF Research Database (Denmark)

    Ferreira, Ana Sofia; Payne, Mark; MacKenzie, Brian

    2012-01-01

    anomaly in chlorophyll concentrations and the gyre index was found for the southern region (region 3). Indications of a strong influence of NASPG index are related to areas within the gyre, which may have an impact in the ecosystem functioning. The results also suggest that physical forcing other than......Changes in the North Atlantic Subpolar gyre (NASPG) have been linked to the interannual variability of primary production. However, little is known about the mechanisms behind both environmental processes, and how the NASPG strength may extend its potential impacts to higher trophic levels...

  18. Food and feeding ecology of emperor penguins in the eastern Weddell Sea

    OpenAIRE

    Klages, Norbert

    1989-01-01

    The diet of the emperor penguin Aptenodytes forsteri in the eastern Weddell Sea, Antarctica was studied during October and November 1986 by stomach content analysis. Emperor penguins fed mainly on Antarctic krill Euphausia superba, Antarctic silverfish Pleuragramma antarcticum and squid Psychroteuthis glacialis. Benthic prey was not found. The prey composition suggests two different feeding strategies, shallow dives exploring the rugged underside of sea ice where krill is taken, and deep dive...

  19. Plastic pollution in the South Pacific subtropical gyre.

    Science.gov (United States)

    Eriksen, Marcus; Maximenko, Nikolai; Thiel, Martin; Cummins, Anna; Lattin, Gwen; Wilson, Stiv; Hafner, Jan; Zellers, Ann; Rifman, Samuel

    2013-03-15

    Plastic marine pollution in the open ocean of the southern hemisphere is largely undocumented. Here, we report the result of a (4489 km) 2424 nautical mile transect through the South Pacific subtropical gyre, carried out in March-April 2011. Neuston samples were collected at 48 sites, averaging 50 nautical miles apart, using a manta trawl lined with a 333 μm mesh. The transect bisected a predicted accumulation zone associated with the convergence of surface currents, driven by local winds. The results show an increase in surface abundance of plastic pollution as we neared the center and decrease as we moved away, verifying the presence of a garbage patch. The average abundance and mass was 26,898 particles km(-2) and 70.96 g km(-2), respectively. 88.8% of the plastic pollution was found in the middle third of the samples with the highest value of 396,342 particles km(-2) occurring near the center of the predicted accumulation zone. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Seabirds, gyres and global trends in plastic pollution.

    Science.gov (United States)

    van Franeker, Jan A; Law, Kara Lavender

    2015-08-01

    Fulmars are effective biological indicators of the abundance of floating plastic marine debris. Long-term data reveal high plastic abundance in the southern North Sea, gradually decreasing to the north at increasing distance from population centres, with lowest levels in high-arctic waters. Since the 1980s, pre-production plastic pellets in North Sea fulmars have decreased by ∼75%, while user plastics varied without a strong overall change. Similar trends were found in net-collected floating plastic debris in the North Atlantic subtropical gyre, with a ∼75% decrease in plastic pellets and no obvious trend in user plastic. The decreases in pellets suggest that changes in litter input are rapidly visible in the environment not only close to presumed sources, but also far from land. Floating plastic debris is rapidly "lost" from the ocean surface to other as-yet undetermined sinks in the marine environment. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. Winter Wonderlands

    Science.gov (United States)

    Coy, Mary

    2011-01-01

    Listening to people complain about the hardships of winter and the dreariness of the nearly constant gray sky prompted the author to help her sixth graders recognize and appreciate the beauty that surrounds them for nearly five months of the year in western New York. The author opines that if students could see things more artistically, the winter…

  2. Density of pack-ice seals and penguins in the western Weddell Sea in relation to ice thickness and ocean depth

    NARCIS (Netherlands)

    Florentino De Souza Silva, A.P.; Haas, C.; Franeker, van J.A.; Meesters, H.W.G.

    2008-01-01

    Aerial band transect censuses were carried out parallel with ice thickness profiling surveys in the pack ice of the western Weddell Sea during the ISPOL (Ice Station POLarstern) expedition of R.V. Polarstern from November 2004 to January 2005. Three regions were surveyed: the deep sea of the Weddell

  3. Past and present stability of the Weddell Sea sector of the Antarctic Ice Sheet

    Science.gov (United States)

    Whitehouse, P. L.; Vieli, A.; Jamieson, S.; Bentley, M.; Hein, A.; Sugden, D.

    2016-12-01

    The contribution of the Weddell Sea sector of the Antarctic Ice Sheet to sea-level rise since the Last Glacial Maximum (LGM), along with the processes controlling the past and ongoing dynamics of this sector, are poorly known. Of particular concern is the fact that significant portions of the present-day grounding line are unstably located on bathymetry that deepens towards the interior of the continent. We present new modelling results, constrained by field evidence relating to past ice extent and thickness along the Foundation Ice Stream and Thiel Trough, which suggest that the post-LGM sea-level contribution from this sector was modest, and that the grounding line is unlikely to have been located at the continental shelf break for a prolonged period during the last glacial cycle. Poorly-constrained ice shelf and ocean processes are found to play a crucial role in controlling the past configuration and stability of this sector of the ice sheet. In particular, we find that we cannot rule out a scenario in which the grounding line of the Foundation Ice Stream retreated behind present during deglaciation, and has since re-advanced. This work complements a number of recent studies, based on independent data sets, that explore the possibility that grounding line re-advance occurred within the Weddell Sea sector during the mid-to-late Holocene. If this hypothesis is correct, then current glacial isostatic adjustment models, and hence contemporary estimates of ice mass balance derived from GRACE data, will be significantly biased. Piecing together, and understanding, the reason for recent changes in ice dynamics is crucial for determining the contemporary stability of the Weddell Sea sector of the Antarctic Ice Sheet.

  4. Dynamics of decadal variability in the Atlantic subpolar gyre: a stochastically forced oscillator

    Energy Technology Data Exchange (ETDEWEB)

    Born, Andreas [University of Bern, Climate and Environmental Physics, Physics Institute, Bern (Switzerland); Oeschger Centre for Climate Change Research, Bern (Switzerland); Bjerknes Centre for Climate Research, Bergen (Norway); University of Bergen, Geophysical Institute, Bergen (Norway); Mignot, Juliette [IPSL/UPMC/CNRS/IRD/MNHN, Laboratoire d' Oceanographie et du Climat, Experimentation et Approches Numeriques, Paris (France)

    2012-07-15

    Internal variability of the Atlantic subpolar gyre is investigated in a 600 years control simulation of a comprehensive coupled climate model. The subpolar gyre shows irregular oscillations of decadal time scale with most spectral power between 15 and 20 years. Positive and negative feedback mechanisms act successively on the circulation leading to an internal oscillation. This involves periodically enhanced deep convection in the subpolar gyre center and intermittently enhanced air-sea thermal coupling. As a result, anomalies of the large-scale atmospheric circulation can be transferred to the ocean on the ocean's intrinsic time scale, exciting the oscillator stochastically. A detailed understanding of oscillatory mechanisms of the ocean and their sensitivity to atmospheric forcing holds considerable potential for decadal predictions as well as for the interpretation of proxy data records. (orig.)

  5. Phytoplankton bloom and subpolar gyre induced dynamics in the North Atlantic

    DEFF Research Database (Denmark)

    Ferreira, Ana Sofia; Hátún, H.; Counillon, F.

    represents the integrated oceanic dynamics over the Northern North Atlantic, while the timing of the spring bloom is more governed by direct atmospheric forcing during the pre-bloom weeks. We, therefore, further investigate which published theories (Sverdrup [1953], Siegel et al [2002], Huisman et al [2002...... dynamics and the subpolar gyre is complex, showing no clear spatial pattern. Our hypothesis is therefore partly refuted, probably due to the disparity in the temporal and spatial resolutions of the subpolar gyre index, compared to indices describing spring bloom dynamics. The annually averaged gyre index......], Townsend et al [1994], and Taylor and Ferrari [2011]) for bloom onset are suited for this region. We construct indicator fields and time series which in various combinations provide models consistent with the principle dynamics proposed in these theories. Using a multi-model inference approach, we...

  6. Assessing variability in the size and strength of the North Atlantic subpolar gyre

    Science.gov (United States)

    Foukal, Nicholas P.; Lozier, M. Susan

    2017-08-01

    Recent studies on the size and strength of the North Atlantic subpolar gyre (SPG) offer contrasting assessments of the gyre's temporal variability: studies that use empirical orthogonal function (EOF) analyses of satellite sea-surface height (SSH) report a rapid decline in SPG size and strength since 1992 (˜20% per decade), while concurrent in situ observations report either no trend or a slight decline. Here we investigate this discrepancy by analyzing the size and strength of the SPG with satellite SSH from 1993 to 2015 with two separate methods: indirectly via EOF analysis and more directly through measurements of the gyre center and boundary. We define the boundary of the gyre as the largest closed contour of SSH, the center as the minimum SSH, and the strength as the difference between the SSH at the boundary and the center. We identify a linear decline over the study period in the SPG strength (5.1% per decade), but find no statistically significant trend in the SPG area. The trend in the gyre strength is weaker than the EOF-based trend and is most likely below the level of detection of the in situ measurements. We conclude that the variability previously identified as a sharp decline in SPG circulation can be more appropriately attributed to basin-wide sea level rise during the satellite altimetry period. In addition, we find that the properties of the eastern SPG do not covary with the SPG size, suggesting that SPG dynamics do not control the strength of the intergyre throughput.Plain Language SummaryFor over a decade there has been a discrepancy in the observed variability of the size and strength of the subpolar gyre: satellite estimates based on the height of the sea-surface were interpreted as showing a rapid decline in the gyre since the early 1990s, while direct measurements from ships and moorings showed the gyre to be quite stable over the same time period. In this work, we reconcile these two measurement techniques by subtracting the long-term sea

  7. New taeniogyrinid species of sea cucumber from the Weddell Sea (Echinodermata: Holothuroidea: Synaptida).

    Science.gov (United States)

    O'Loughlin, P Mark; Mackenzie, Melanie; VandenSpiegel, Didier; Griffiths, Huw

    2015-08-05

    The case put by Alexei Smirnov in 2012 is accepted and the order name Synaptida Cuénot is adopted in place of Apodida Brandt. Two new Synaptida species are described for the Weddell Sea in Antarctica with single author O'Loughlin: Sigmodota magdarogera sp. nov. and Taeniogyrus bamberi sp. nov.. A specimen of Sigmodota magnibacula (Massin & Hétérier) is described. A key is provided for the genera and species of Taeniogyrinae that occur south of the Antarctic Convergence.

  8. Microbiome of Trichodesmium Colonies from the North Pacific Subtropical Gyre

    Directory of Open Access Journals (Sweden)

    Mary R. Gradoville

    2017-07-01

    Full Text Available Filamentous diazotrophic Cyanobacteria of the genus Trichodesmium, often found in colonial form, provide an important source of new nitrogen to tropical and subtropical marine ecosystems. Colonies are composed of several clades of Trichodesmium in association with a diverse community of bacterial and eukaryotic epibionts. We used high-throughput 16S rRNA and nifH gene sequencing, carbon (C and dinitrogen (N2 fixation assays, and metagenomics to describe the diversity and functional potential of the microbiome associated with Trichodesmium colonies collected from the North Pacific Subtropical Gyre (NPSG. The 16S rRNA and nifH gene sequences from hand-picked colonies were predominantly (>99% from Trichodesmium Clade I (i.e., T. thiebautii, which is phylogenetically and ecologically distinct from the Clade III IMS101 isolate used in most laboratory studies. The bacterial epibiont communities were dominated by Bacteroidetes, Alphaproteobacteria, and Gammaproteobacteria, including several taxa with a known preference for surface attachment, and were relatively depleted in the unicellular Cyanobacteria and small photoheterotrophic bacteria that dominate NPSG surface waters. Sequencing the nifH gene (encoding a subcomponent of the nitrogenase enzyme identified non-Trichodesmium diazotrophs that clustered predominantly among the Cluster III nifH sequence-types that includes putative anaerobic diazotrophs. Trichodesmium colonies may represent an important habitat for these Cluster III diazotrophs, which were relatively rare in the surrounding seawater. Sequence analyses of nifH gene transcripts revealed several cyanobacterial groups, including heterocystous Richelia, associated with the colonies. Both the 16S rRNA and nifH datasets indicated strong differences between Trichodesmium epibionts and picoplankton in the surrounding seawater, and also between the epibionts inhabiting Trichodesmium puff and tuft colony morphologies. Metagenomic and 16S r

  9. Features of the propagation of pseudorandom pulse signals from the shelf to deep water in the presence of gyre formation on the acoustic track

    Science.gov (United States)

    Akulichev, V. A.; Burenin, A. V.; Ladychenko, S. Yu.; Lobanov, V. B.; Morgunov, Yu. N.

    2017-08-01

    The paper discusses the results of an experiment conducted in the Sea of Japan in March 2016 on an acoustic track 194 km long in winter hydrological conditions. The most complex case of propagation of pseudorandom pulse signals from the shelf to deep water in the presence of gyre formation on the acoustic track. An analysis of the experimentally obtained pulse characteristics show that at all points, a maximum, in terms of amplitude, first arrival of acoustic energy is recorded. This is evidence that at a given depth horizon, pulses that have passed the shortest distance through a near-surface sound channel at small angles close to zero are received first. The calculation method of mean sound velocity on the track, based on the satellite data of surface temperature monitoring, is proposed. We expect that the results obtained with this method can be successfully used for the purposes of acoustic range finding and navigation.

  10. Interannual and Decadal Changes in Salinity in the Oceanic Subtropical Gyres

    Science.gov (United States)

    Bulusu, Subrahmanyam

    2017-04-01

    There is evidence that the global water cycle has been undergoing an intensification over several decades as a response to increasing atmospheric temperatures, particularly in regions with skewed evaporation - precipitation (E-P) patterns such as the oceanic subtropical gyres. Moreover, observational data (rain gauges, etc.) are quite sparse over such areas due to the inaccessibility of open ocean regions. In this work, a comparison of observational and model simulations are conducted to highlight the potential applications of satellite derived salinity from NASA Aquarius Salinity mission, NASA Soil Moisture and Ocean Salinity (SMOS), and ESA's Soil Moisture Active Passive (SMAP). We explored spatial and temporal salinity changes (and trends) in surface and subsurface in the oceanic subtropical gyres using Argo floats salinity data, Simple Ocean Data Assimilation (SODA) reanalysis, Estimating the Circulations & Climate of the Ocean GECCO (German ECCO) model simulations, and Hybrid Coordinate Ocean Model (HYCOM). Our results based on SODA reanalysis reveals that a positive rising trend in sea surface salinity in the subtropical gyres emphasizing evidence for decadal intensification in the surface forcing in these regions. Zonal drift in the location of the salinity maximum of the south Pacific, north Atlantic, and south Indian regions implies a change in the mean near-surface currents responsible for advecting high salinity waters into the region. Also we found out that an overall salinity increase within the mixed layer, and a subsurface salinity decrease at depths greater than 200m in the global subtropical gyres over 61 years. We determine that freshwater fluxes at the air-sea interface are the primary drivers of the sea surface salinity (SSS) signature over these open ocean regions by quantifying the advective contribution within the surface layer. This was demonstrated through a mixed layer salinity budget in each subtropical gyre based on the vertically

  11. Steep reverse bed slope at the grounding line of the Weddell Sea sector in West Antarctica

    Science.gov (United States)

    Ross, Neil; Bingham, Robert G.; Corr, Hugh F. J.; Ferraccioli, Fausto; Jordan, Tom A.; Le Brocq, Anne; Rippin, David M.; Young, Duncan; Blankenship, Donald D.; Siegert, Martin J.

    2012-06-01

    The bed of the West Antarctic Ice Sheet is, in places, more than 1.5km below sea level. It has been suggested that a positive ice-loss feedback may occur when an ice sheet's grounding line retreats across a deepening bed. Applied to the West Antarctic Ice Sheet, this process could potentially raise global sea level by more than 3m. Hitherto, attention has focussed on changes at the Siple Coast and Amundsen Sea embayment sectors of West Antarctica. Here, we present radio-echo sounding information from the ice sheet's third sector, the Weddell Sea embayment, that reveals a large subglacial basin immediately upstream of the grounding line. The reverse bed slope is steep, with about 400 m of decline over 40km. The basin floor is smooth and flat, with little small-scale topography that would delay retreat, indicating that it has been covered with marine sediment and was previously deglaciated. Upstream of the basin, well-defined glacially carved fjords with bars at their mouths testify to the position of a former ice margin about 200km inland from the present margin. Evidence so far suggests that the Weddell Sea sector of the West Antarctic Ice Sheet has been stable, but in the light of our data we propose that the region could be near a physical threshold of substantial change.

  12. Controls on Last Glacial Maximum ice extent in the Weddell Sea embayment, Antarctica

    Science.gov (United States)

    Whitehouse, Pippa L.; Bentley, Michael J.; Vieli, Andreas; Jamieson, Stewart S. R.; Hein, Andrew S.; Sugden, David E.

    2017-01-01

    The Weddell Sea sector of the Antarctic Ice Sheet is hypothesized to have made a significant contribution to sea-level rise since the Last Glacial Maximum. Using a numerical flowline model we investigate the controls on grounding line motion across the eastern Weddell Sea and compare our results with field data relating to past ice extent. Specifically, we investigate the influence of changes in ice temperature, accumulation, sea level, ice shelf basal melt, and ice shelf buttressing on the dynamics of the Foundation Ice Stream. We find that ice shelf basal melt plays an important role in controlling grounding line advance, while a reduction in ice shelf buttressing is found to be necessary for grounding line retreat. There are two stable positions for the grounding line under glacial conditions: at the northern margin of Berkner Island and at the continental shelf break. Global mean sea-level contributions associated with these two scenarios are 50 mm and 130 mm, respectively. Comparing model results with field evidence from the Pensacola Mountains and the Shackleton Range, we find it unlikely that ice was grounded at the continental shelf break for a prolonged period during the last glacial cycle. However, we cannot rule out a brief advance to this position or a scenario in which the grounding line retreated behind present during deglaciation and has since re-advanced. Better constraints on past ice sheet and ice shelf geometry, ocean temperature, and ocean circulation are needed to reconstruct more robustly past behavior of the Foundation Ice Stream.

  13. Three new species of deep-sea Gromia (Protista, Rhizaria) from the bathyal and abyssal Weddell Sea, Antarctica

    DEFF Research Database (Denmark)

    Rothe, Nina; Gooday, Andrew J.; Cedhagen, Tomas

    2009-01-01

    We describe three new species of the genus Gromia from bathyal and abyssal depths in the Weddell Sea. The new species are characterized by a combination of morphological and molecular criteria. All three species possess a distinct oral capsule and a layer of ‘honeycomb membranes’, which form the ...

  14. Trace element analysis in the serum and hair of Antarctic leopard seal, Hydrurga leptonyx, and Weddell seal, Leptonychotes weddellii

    International Nuclear Information System (INIS)

    Gray, Rachael; Canfield, Paul; Rogers, Tracey

    2008-01-01

    Leopard seal, Hydrurga leptonyx, and Weddell seal, Leptonychotes weddellii, occupy an upper trophic level within the Antarctic ecosystem and are useful indicator species in the Southern Ocean of trace element concentrations. Reference values for the concentration of 19 trace elements were determined in the serum and hair of leopard and Weddell seals sampled in Eastern Antarctica. These reference values can be used as 'baseline' levels for monitoring trace element concentrations in these species. Greater trace element concentrations were determined in hair compared to serum, indicating different time scales of trace element accumulation in these samples. For the majority of trace elements, except for Se in the leopard seal samples and Cr in the Weddell seal samples, significant regression relationships for trace element concentrations in hair and serum were not elucidated. Significant differences were determined in the concentrations of seven out of 15 elements with hair type, moult and new, in the leopard seal; concentrations in moult hair were determined to be greater than in new hair for all elements except Zn. Hair analysis was determined to be useful for monitoring exposure to trace elements and when collected off the ice from moulting seals, hair can be employed as a non-invasive sample for trace element analysis in leopard and Weddell seals

  15. Trace element analysis in the serum and hair of Antarctic leopard seal, Hydrurga leptonyx, and Weddell seal, Leptonychotes weddellii

    Energy Technology Data Exchange (ETDEWEB)

    Gray, Rachael [Faculty of Veterinary Science, University of Sydney, NSW 2006 Australia (Australia); Australian Marine Mammal Research Centre PO Box 20 Mosman, NSW 2088 (Australia)], E-mail: rgray@vetsci.usyd.edu.au; Canfield, Paul [Faculty of Veterinary Science, University of Sydney, NSW 2006 (Australia); Rogers, Tracey [Australian Marine Mammal Research Centre PO Box 20 Mosman, NSW 2088 (Australia); Evolution and Ecology Research Centre and School of Biological Earth and Environmental Sciences, University of New South Wales, NSW 2052 (Australia)

    2008-07-25

    Leopard seal, Hydrurga leptonyx, and Weddell seal, Leptonychotes weddellii, occupy an upper trophic level within the Antarctic ecosystem and are useful indicator species in the Southern Ocean of trace element concentrations. Reference values for the concentration of 19 trace elements were determined in the serum and hair of leopard and Weddell seals sampled in Eastern Antarctica. These reference values can be used as 'baseline' levels for monitoring trace element concentrations in these species. Greater trace element concentrations were determined in hair compared to serum, indicating different time scales of trace element accumulation in these samples. For the majority of trace elements, except for Se in the leopard seal samples and Cr in the Weddell seal samples, significant regression relationships for trace element concentrations in hair and serum were not elucidated. Significant differences were determined in the concentrations of seven out of 15 elements with hair type, moult and new, in the leopard seal; concentrations in moult hair were determined to be greater than in new hair for all elements except Zn. Hair analysis was determined to be useful for monitoring exposure to trace elements and when collected off the ice from moulting seals, hair can be employed as a non-invasive sample for trace element analysis in leopard and Weddell seals.

  16. Trace element analysis in the serum and hair of Antarctic leopard seal, Hydrurga leptonyx, and Weddell seal, Leptonychotes weddellii.

    Science.gov (United States)

    Gray, Rachael; Canfield, Paul; Rogers, Tracey

    2008-07-25

    Leopard seal, Hydrurga leptonyx, and Weddell seal, Leptonychotes weddellii, occupy an upper trophic level within the Antarctic ecosystem and are useful indicator species in the Southern Ocean of trace element concentrations. Reference values for the concentration of 19 trace elements were determined in the serum and hair of leopard and Weddell seals sampled in Eastern Antarctica. These reference values can be used as 'baseline' levels for monitoring trace element concentrations in these species. Greater trace element concentrations were determined in hair compared to serum, indicating different time scales of trace element accumulation in these samples. For the majority of trace elements, except for Se in the leopard seal samples and Cr in the Weddell seal samples, significant regression relationships for trace element concentrations in hair and serum were not elucidated. Significant differences were determined in the concentrations of seven out of 15 elements with hair type, moult and new, in the leopard seal; concentrations in moult hair were determined to be greater than in new hair for all elements except Zn. Hair analysis was determined to be useful for monitoring exposure to trace elements and when collected off the ice from moulting seals, hair can be employed as a non-invasive sample for trace element analysis in leopard and Weddell seals.

  17. Basic epidemiological data on metazoan parasites of notothenioid fish off James Ross Island (Prince Gustav Channel, Weddell Sea), Antarctica

    Czech Academy of Sciences Publication Activity Database

    Nezhybová, Veronika; Mašová, Š.

    2015-01-01

    Roč. 5, č. 1 (2015), s. 44-54 ISSN 1805-0689 R&D Projects: GA ČR(CZ) GBP505/12/G112 Institutional support: RVO:68081766 Keywords : Host * Notothenioid fish * Parasites * Prince Gustav Channel * Weddell Sea Subject RIV: EG - Zoology

  18. Organophosphorus esters in the oceans and possible relation with ocean gyres

    International Nuclear Information System (INIS)

    Cheng, Wenhan; Xie, Zhouqing; Blais, Jules M.; Zhang, Pengfei; Li, Ming; Yang, Chengyun; Huang, Wen; Ding, Rui; Sun, Liguang

    2013-01-01

    Four organophosphorus esters (OPEs) were detected in aerosol samples collected in the West Pacific, the Indian Ocean and the Southern Ocean from 2009 to 2010, suggesting their circumpolar and global distribution. In general, the highest concentrations were detected near populated regions in China, Australia and New Zealand. OPE concentrations in the Southern Ocean were about two orders of magnitude lower than those near major continents. Additionally, relatively high OPE concentrations were detected at the Antarctic Peninsula, where several scientific survey stations are located. The four OPEs investigated here are significantly correlated with each other, suggesting they may derive from the same source. In the circumpolar transect, OPE concentrations were associated with ocean gyres in the open ocean. Their concentrations were positively related with average vorticity in the sampling area suggesting that a major source of OPEs may be found in ocean gyres where plastic debris is known to accumulate. -- Highlights: •We provide OPE concentrations in aerosols in a circumpolar expedition. •We find strong anthropogenic source of OPE pollution. •We suggest potential relationship between ocean gyres and OPE pollution. -- Our work provides a circumpolar investigation on OPEs in the Southern Ocean and we suggest a possibility that ocean currents and gyres may act as important roles in global transport of OPEs

  19. Anticyclonic eddies increase accumulation of microplastic in the North Atlantic subtropical gyre

    NARCIS (Netherlands)

    Brach, Laurent; Deixonne, Patrick; Bernard, Marie France; Durand, Edmée; Desjean, Marie Christine; Perez, Emile; van Sebille, Erik; ter Halle, Alexandra

    2018-01-01

    There are fundamental gaps in our understanding of the fates of microplastics in the ocean, which must be overcome if the severity of this pollution is to be fully assessed. The predominant pattern is high accumulation of microplastic in subtropical gyres. Using in situ measurements from the 7th

  20. Sea ice concentration temporal variability over the Weddell Sea and its relationship with tropical sea surface temperature

    Science.gov (United States)

    Barreira, S.; Compagnucci, R.

    2007-01-01

    Principal Components Analysis (PCA) in S-Mode (correlation between temporal series) was performed on sea ice monthly anomalies, in order to investigate which are the main temporal patterns, where are the homogenous areas located and how are they related to the sea surface temperature (SST). This analysis provides 9 patterns (4 in the Amundsen and Bellingshausen Seas and 5 in the Weddell Sea) that represent the most important temporal features that dominated sea ice concentration anomalies (SICA) variability in the Weddell, Amundsen and Bellingshausen Seas over the 1979-2000 period. Monthly Polar Gridded Sea Ice Concentrations data set derived from satellite information generated by NASA Team algorithm and acquired from the National Snow and Ice Data Center (NSIDC) were used. Monthly means SST are provided by the National Center for Environmental Prediction reanalysis. The first temporal pattern series obtained by PCA has its homogeneous area located at the external region of the Weddell and Bellingshausen Seas and Drake Passage, mostly north of 60°S. The second region is centered in 30°W and located at the southeast of the Weddell. The third area is localized east of 30°W and north of 60°S. South of the first area, the fourth PC series has its homogenous region, between 30° and 60°W. The last area is centered at 0° W and south of 60°S. Correlation charts between the five Principal Components series and SST were performed. Positive correlations over the Tropical Pacific Ocean were found for the five PCs when SST series preceded SICA PC series. The sign of the correlation could relate the occurrence of an El Niño/Southern Oscillation (ENSO) warm (cold) event with posterior positive (negative) anomalies of sea ice concentration over the Weddell Sea.

  1. Long-term inter-annual variability of a cyclonic gyre in the western Irish Sea

    Science.gov (United States)

    Olbert, Agnieszka I.; Hartnett, Michael; Dabrowski, Tomasz; Mikolajewicz, Uwe

    2011-09-01

    The western Irish Sea gyre (WISG) is a cyclonic baroclinic flow around a dome of stagnant water which develops each year during the heating season in the western Irish Sea. Research was carried out to determine long-term changes in the strength of stratification within WISG and associated changes in the gyre structure, circulation patterns and retentive properties. Model simulations were carried out for the 58-year period 1951-2008. The characteristics of the gyre were quantified by means of potential energy anomaly (PEA), measuring the strength of stratification, and total kinetic energy (KE), reflecting the strength of cyclonic circulation. Additionally, long-term changes in flushing rates within the gyre were assessed. Results show that stratification in the western Irish Sea consistently begins to develop in March, increases linearly from April till June, peaks at the beginning of July and remains at close to maximum level throughout the month of July, before a start of a sharp decline at the beginning of August. The strength of stratification is significantly correlated with averaged summer air temperatures and summer wind speeds. Trend analysis of PEA shows an increase in the stratification strength over the period considered; the increase of PEA peak value is accompanied by a shortening of the gyre duration and a delay in the timing of the peak value. There is also an increasing trend in the KE value, showing that the thermal stratification plays a crucial role in the hydrography of the region. Flushing analysis shows that the stronger the stratification the lower the residence time and thus the faster the removal of the material from the western Irish Sea. Residence time within WISG shortens on average by 8 days over the 58-year period.

  2. WINTER SAECULUM

    Directory of Open Access Journals (Sweden)

    Emil Mihalina

    2017-03-01

    Full Text Available Accumulated imbalances in the economy and on the markets cause specific financial market dynamics that have formed characteristic patterns kept throughout long financial history. In 2008 Authors presented their expectations of key macroeconomic and selected asset class markets developments for period ahead based on Saeculum theory. Use of term Secular describes a specific valuation environment during prolonged period. If valuations as well as selected macro variables are considered as a tool for understanding business cycles then market cycles become much more obvious and easily understandable. Therefore over the long run, certain asset classes do better in terms of risk reward profile than others. Further on, there is no need for frequent portfolio rebalancing and timing of specific investment positions within a particular asset class market. Current stage in cycle development suggests a need for reassessment of trends and prevailing phenomena due to cyclical nture of long lasting Saeculums. Paper reviews developments in recognizable patterns of selected metrics in current Winter Saeculum dominated with prevailing forces of delivering, deflation and decrease in velocity of money.

  3. Bringing Antarctic Weddell seals to the classroom through PolarTREC

    Science.gov (United States)

    Eilers, A. A.

    2017-12-01

    PolarTREC (Teachers and Researchers Exploring and Collaborating) is an NSF funded professional development opportunity in which K-12 teachers and informal educators participated in hands-on field research experiences in the Polar Regions. The program goal is to invigorate polar science education and understanding by bringing together educators and polar researchers. This unique opportunity for educators has two main components: a 4-6 week field experience and a classroom/community connection piece. In preparation for these experiences, museum educator Alex Eilers and science team lead Dr. Jennifer Burns planned, developed and executed extensive outreach efforts for both students and the community to highlight the Weddell seal research project during the 2012, 2014 and 2016 seasons. The following outreach activities summarize the team's most successful attempts at engaging schoolchildren, teachers and the public, creating a broader impact of the Weddell seal scientific project. On-line Daily journal entries were uploaded to the PolarTREC website encouraging an active interaction between the science team and participants. A Polar Connect event offered participants a real-time, interactive internet presentation with the team. Schools A multitude of on-site presentations were made in classrooms, at teacher workshops and faculty meetings. Two 45 minute labs were developed for students visiting the museum, Animals of the Antarctic and Journey to the Poles, the latter is now included in our ongoing program repertoire. Two travelling kits, Extreme Cold Weather Gear and The Weddell Seal, were developed by museum staff and continue to circulate through schools. A multi-lesson educational module was developed by museum staff to bridge the gap between the scientific research conducted in the field and students in grades 3-8. It contains curriculum-based lessons, field data and strategic methods to assist students in analyzing the data. Community Community-wide interest

  4. Winter Weather: Frostbite

    Science.gov (United States)

    ... Safety During Fire Cleanup Wildfires PSAs Related Links Winter Weather About Winter Weather Before a Storm Prepare Your Home Prepare Your Car Winter Weather Checklists During a Storm Indoor Safety During ...

  5. Progress report on the scientific data compilation and analyses in support of the development of a CCAMLR MPA in the Weddell Sea (Antarctica)

    OpenAIRE

    Teschke, Katharina; Bornemann, Horst; Bombosch, Annette; Brey, Thomas; Brtnik, Patricia; Burkhardt, Elke; Dorschel, Boris; Feindt-Herr, Helena; Gerdes, Dieter; Gutt, Julian; Hain, Stefan; Herata, Heike; Jerosch, Kerstin; Knust, Rainer; Kock, Karl-Hermann

    2013-01-01

    At the CCAMLR meeting in 2012, the Commission welcomed the offer of Germany to take the lead in developing a Weddell Sea MPA for consideration in 2014. Subsequently, the German Federal Ministry of Food, Agriculture and Consumer Protection tasked the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research to compile and analyse scientific data for identifying areas which require particular protection in the Weddell Sea. Work under this project started mid-April 2013. This prog...

  6. A new species of Halcampella (Actiniaria, Halcampoididae from the eastern Weddell Sea and Antarctic Peninsula

    Directory of Open Access Journals (Sweden)

    Estefanía Rodríguez

    2002-03-01

    Full Text Available A new species of soft-bottom-dwelling sea anemone of the genus Halcampella is described and illustrated based on 47 specimens collected during the Polarstern cruises ANT XV/3 and ANT XVII/3 to the Antarctic Peninsula and the eastern Weddell Sea. The new Halcampella species is easily distinguishable from its congeners by the number of cycles of mesenteries and tentacles, the cnidae and the geographic distribution. The new species is described and compared to the available type material of the other species of the genus and new cnidae data are given for H. maxima Hertwig, 1888 and H. robusta Carlgren, 1931. According to other authors H. endromitata (Andres, 1881 is considered a nomen dubium and H. maxima is here proposed as the types species of the genus.

  7. Multiple deep gyres of the western North Pacific: A WOCE section along 149°E

    Science.gov (United States)

    Wijffels, Susan E.; Hall, Melinda M.; Joyce, Terrence; Torres, Daniel J.; Hacker, Peter; Firing, Eric

    1998-06-01

    The top to bottom large-scale ocean circulation in the northwest Pacific is described using a World Ocean Circulation Experiment (WOCE) onetime hydrographic section along 149°E between Papua New Guinea and Japan. The circulation is quantified using a combination of geostrophic and lowered acoustic Doppler current profiler velocity estimates. At the northern end of the section the flow regime is distinct in that the deep flow largely reflects that at the surface: the Kuroshio jet and its northern and southern recirculations have deep expressions. South of 25°N, the deep and bottom water flows do not mirror the surface flows, and the circulation assumes a highly baroclinic structure. Below the depth of local North Pacific ventilation the flow in the upper deep waters (800-2500 m) alternates in sign roughly every 10° of latitude revealing a set of deep clockwise gyres with significant transports of 40 Sv (1 Sv = 106m3s-1) for a tropical gyre (south of 6°N) and 20 Sv in a subtropical gyre (6°-24°N). These gyres provide a pathway for South Pacific influences to reach 22°N (the location of a strong water mass front) through exchange along the western boundary. Maps of properties on density surfaces suggest that the zonal extent of the upper deep water gyres found along 149°E is basin wide. Below 2500 m, flow across the section is isolated from the Philippine Sea by the Izu-Ogasawara-Mariana Ridge and the flow regime and property distribution reflect this: Lower Circumpolar Water flows west in a deep western boundary current near 10°N and coalesces at the Izu-Ogasawara-Mariana Ridge with a tongue of North Pacific Deep Water also flowing west near 15°N. About 4 Sv of a mixture of these waters flows east again near 25°N, associated with an abyssal water mass front. North of the front, the water properties are laterally homogeneous on density surfaces in the strongly recirculating gyres associated with the deep Kuroshio system.

  8. Variability in temporary emigration rates of individually marked female Weddell seals prior to first reproduction.

    Science.gov (United States)

    Stauffer, Glenn E; Rotella, Jay J; Garrott, Robert A

    2013-05-01

    In many species, temporary emigration (TE) is a phenomenon, often indicative of life-history characteristics such as dormancy, skipped reproduction, or partial migration, whereby certain individuals in a population are temporarily unobservable at a particular site. TE may be a flexible condition-dependent strategy that allows individuals to mitigate effects of adverse conditions. Consequently, TE rates ought to be highly variable, but sources of variations are poorly understood for most species. We used data from known-aged female Weddell seals (Leptonychotes weddellii) tagged in Erebus Bay, Antarctica, to investigate sources of variation in TE rates prior to reproduction and to evaluate possible implications for age-specific probability of first reproduction. TE rates were near 1 the year after birth, decreased to an average of 0.15 (SE = 0.01) by age 8, and were similar thereafter. TE rates varied substantially from year-to-year and were lower for seals that attended reproductive colonies the previous year than for seals that did not attend (e.g., ψ(i,age 8)(UU) - ψ(i, age 8)(PU) = 0.22). Recruitment rates were marginally greater for seals that did attend than for seals that did not attend colonies the previous year. For Weddell seals specifically, our results suggest that (1) motivation to attend colonies varied temporally, (2) as seals grew older they had increased motivation to attend even before reproductive maturity, and (3) seals appear to follow various attendance strategies. More broadly, our results support the idea of TE as a variable, condition-dependent strategy, and highlight the utility of TE models for providing population and life-history insights for diverse taxa.

  9. Relationship between the Northern Pacific Gyre Oscillation and tree-ring cellulose oxygen isotopes in northeastern Japan

    Science.gov (United States)

    Sakashita, Wataru; Miyahara, Hiroko; Yokoyama, Yusuke; Aze, Takahiro; Obrochta, Stephen P.; Nakatsuka, Takeshi

    2017-12-01

    The North Pacific Gyre Oscillation (NPGO) significantly imprints on hydrological fluctuations of the East Asian summer monsoon (EASM) region, but this has not yet been observed in proxy-based hydroclimate reconstructions. This study reports a tree-ring cellulose oxygen isotope (δ18O) record from northeastern Japan spanning A.D. 1927-2010, overlapping with instrumental data, which we analyzed to determine if tree-ring δ18O in northeastern Japan records a signal consistent with the NPGO. Our results indicate that the tree-ring δ18O has a significant negative correlation with May-June (MJ) precipitation, as well as with short-term MJ relative humidity variation. Time-lagged temporal-domain comparisons indicate that the tree-ring δ18O is significantly correlated with the following year March-April (MA) and MJ NPGO index before the North Pacific climate transition in the late 1980s, particularly on decadal timescales. These relationships between our tree-ring δ18O and the climate patterns in the North Pacific are consistent with the actual early-summer precipitation. Spatial spring and early-summer sea-surface temperature anomalies exhibit a NPGO-like pattern in the following year. Spatial early-summer sea-level pressure anomalies also indicate North Pacific Oscillation (NPO) like patterns in the western North Pacific. These results suggest a lagged response of the NPGO to the EASM climate changes, and tree-ring δ18O in northeast Japan has a potential linkage with NPGO index from winter to early summer of the following year.

  10. Anticyclonic eddies increase accumulation of microplastic in the North Atlantic subtropical gyre.

    Science.gov (United States)

    Brach, Laurent; Deixonne, Patrick; Bernard, Marie-France; Durand, Edmée; Desjean, Marie-Christine; Perez, Emile; van Sebille, Erik; Ter Halle, Alexandra

    2018-01-01

    There are fundamental gaps in our understanding of the fates of microplastics in the ocean, which must be overcome if the severity of this pollution is to be fully assessed. The predominant pattern is high accumulation of microplastic in subtropical gyres. Using in situ measurements from the 7th Continent expedition in the North Atlantic subtropical gyre, data from satellite observations and models, we show how microplastic concentrations were up to 9.4 times higher in an anticyclonic eddy explored, compared to the cyclonic eddy. Although our sample size is small, this is the first suggestive evidence that mesoscale eddies might trap, concentrate and potentially transport microplastics. As eddies are known to congregate nutrients and organisms, this phenomenon should be considered with regards to the potential impact of plastic pollution on the ecosystem in the open ocean. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. On the Importance of Lateral Nutrient Transport: A Shift in the New Production Paradigm for the Subtropical Ocean Gyres

    Science.gov (United States)

    Letscher, R. T.; Primeau, F.; Moore, J. K.

    2016-02-01

    A widely used assumption for estimating the strength of the organic carbon export flux is that one-dimensional vertical processes dominate the supply and loss of nutrients to the euphotic zone. However, for the North Atlantic subtropical gyre, lateral inputs of nutrients by convergent Ekman transport have been suggested to be important. Here we use a biogeochemical ocean circulation model constrained by dissolved organic matter concentration measurements to show that on annual timescales, lateral transport of organic and inorganic nitrogen (N) and phosphorus (P) from the gyre margins and its subsequent biological utilization supplies a flux that can exceed vertical nutrient supply across all subtropical gyre systems. Lateral nutrient transport supplies 25-40% of the N and 40-70% of the P necessary to balance new and export production in these regions. We also find that the proportion of the nutrient supply sustained by lateral transport in the gyres is strongly correlated with ecosystem stoichiometry, exhibiting high N:P and C:P within the gyres receiving the most nutrients laterally. Our results suggest that the predicted future decline in biological carbon export due to decreasing vertical inputs of nutrients to surface waters might be partly offset by a concomitant increase in ecosystem carbon to nutrient ratios accompanying a shift to an increased importance of lateral nutrient inputs in the subtropical gyres.

  12. The gyre-scale circulation of the North Atlantic and sea level at Brest

    Directory of Open Access Journals (Sweden)

    P. L. Woodworth

    2010-02-01

    Full Text Available The relationship between the gyre-scale circulation of the North Atlantic, represented by air pressure near to the centre of the sub-tropical gyre, and sea level measured at the eastern boundary of the ocean has been investigated using records commencing in the middle of the 18th century. These time series are twice as long as those employed in an earlier study of this relationship. Near-continuous values of annual mean sea level and mean high water from Brest, and air pressure fields for the eastern North Atlantic derived from terrestrial instrumental pressure records and ship logbook information, have been used to demonstrate that sea level on the eastern boundary does indeed appear to be related to air pressure at the centre of the gyre (subject to reservations concerning short sub-sections of data near to the ends of the records. These findings confirm the earlier conclusions but over much longer timescales. This relationship can explain at least part of the century timescale accelerations in European sea level records obtained from tide gauge and saltmarsh data. This finding has important implications for interpretation of the observed sea level rise and acceleration on the European Atlantic coast, suggesting that redistribution of water could play an important role instead of (or as well as change in ocean volume.

  13. Low post-glacial rebound rates in the Weddell Sea due to Late Holocene ice-sheet readvance.

    OpenAIRE

    Bradley, S.L.; Hindmarsh, R.C.A.; Whitehouse, P.L.; Bentley, M.J.; King, M.A.

    2015-01-01

    Many ice-sheet reconstructions assume monotonic Holocene retreat for the West Antarctic Ice Sheet, but an increasing number of glaciological observations infer that some portions of the ice sheet may be readvancing, following retreat behind the present-day margin. A readvance in the Weddell Sea region can reconcile two outstanding problems: (i) the present-day widespread occurrence of seemingly stable ice streams grounded on beds that deepen inland; and (ii) the inability of models of glacial...

  14. Effect of UV-B irradiance on the ATP content of microorganisms of the Weddell Sea (Antartica)

    Energy Technology Data Exchange (ETDEWEB)

    Vosjan, J.H.; Nieuwland, G. (Netherlands Inst. for Sea Research, Den Burg (Netherlands)); Doehler, G. (Frankfurt Universitaet (Federal Republic of Germany). Botanisches Institut)

    1990-06-01

    The effect of UV-B irradiation on the ATP content of natural assemblages of planktonic microorganisms in the upper 30-m water layer of the Weddell Sea (Antartica) was studied. After five hours of irradiation with UV (290-320 nm) of 1.35 W.m{sup -2} a 75% decrease in the ATP content of the microorganisms was observed. (author). 11 refs.; 3 figs.

  15. Effect of UV-B irradiance on the ATP content of microorganisms of the Weddell Sea (Antartica)

    International Nuclear Information System (INIS)

    Vosjan, J.H.; Nieuwland, G.; Doehler, G.

    1990-01-01

    The effect of UV-B irradiation on the ATP content of natural assemblages of planktonic microorganisms in the upper 30-m water layer of the Weddell Sea (Antartica) was studied. After five hours of irradiation with UV (290-320 nm) of 1.35 W.m -2 a 75% decrease in the ATP content of the microorganisms was observed. (author). 11 refs.; 3 figs

  16. Proposal for the establishment of a marine CCAMLR MPA in the Weddell Sea (Antarctica) – First conceptual outline

    OpenAIRE

    Teschke, Katharina; Dorschel, Boris; Gutt, Julian; Hain, Stefan; Hellmer, Hartmut; Jerosch, Kerstin; Knust, Rainer; Kock, Karl-Hermann; Schlüter, Michael; Siegel, Volker; Brey, Thomas

    2013-01-01

    In recent years, CCAMLR member states undertook substantial efforts to designate marine protected areas (MPAs) in the Southern Ocean. While MPA planning for six domains is underway, for three domains CCAMLR member states were asked to take the lead in MPA planning. At the CCAMLR meeting in 2012, the Commission welcomed the offer of Germany to take the lead in developing a Weddell Sea MPA for consideration in 2014. Subsequently, the German Federal Ministry of Food, Agriculture and Consumer Pro...

  17. Scientific background document in support of the development of a CCAMLR MPA in the Weddell Sea (Antarctica) – Version 2014

    OpenAIRE

    Teschke, Katharina; Bester, M. N.; Bornemann, Horst; Brandt, Angelika; Brtnik, Patricia; De Broyer, Claude; Burkhardt, Elke; Dieckmann, Gerhard; Flores, Hauke; Gerdes, Dieter; Griffiths, H. J.; Gutt, Julian; Hain, Stefan; Hellmer, Hartmut; Herata, Heike

    2014-01-01

    Germany intends to present the Scientific Committee the background document that provides the scientific basis for the evaluation of marine protected areas (MPAs) in the Weddell Sea. Please note, that the current state of the background document presents a comprehensive yet incomplete first version concerning chapters that have to be (further) developed or revised. The contents and structure of the document reflect also its main objectives, i.e. (i) to set out the general background and conte...

  18. Serum chemistry and antibodies against pathogens in antarctic fur seals, Weddell seals, crabeater seals, and Ross seals.

    Science.gov (United States)

    Tryland, Morten; Nymo, Ingebjørg H; Nielsen, Ole; Nordøy, Erling S; Kovacs, Kit M; Krafft, Bjørn A; Thoresen, Stein I; Åsbakk, Kjetil; Osterrieder, Klaus; Roth, Swaantje J; Lydersen, Christian; Godfroid, Jacques; Blix, Arnoldus S

    2012-07-01

    Information on health parameters, such as antibody prevalences and serum chemistry that can reveal exposure to pathogens, disease, and abnormal physiologic conditions, is scarce for Antarctic seal species. Serum samples from Antarctic fur seals (Arctocephalus gazella, n=88) from Bouvetøya (2000-2001 and 2001-2002), and from Weddell seals (Leptonychotes weddellii, n=20), Ross seals (Ommatophoca rossii, n=20), and crabeater seals (Lobodon carcinophagus, n=9) from the pack-ice off Queen Maud Land, Antarctica (2001) were analyzed for enzyme activity, and concentrations of protein, metabolites, minerals, and cortisol. Adult Antarctic fur seal males had elevated levels of total protein (range 64-99 g/l) compared to adult females and pups (range 52-79 g/l). Antarctic fur seals had higher enzyme activities of creatine kinase, lactate dehydrogenase, and amylase, compared to Weddell, Ross, and crabeater seals. Antibodies against Brucella spp. were detected in Weddell seals (37%), Ross seals (5%), and crabeater seals (11%), but not in Antarctic fur seals. Antibodies against phocine herpesvirus 1 were detected in all species examined (Antarctic fur seals, 58%; Weddell seals, 100%; Ross seals, 15%; and crabeater seals, 44%). No antibodies against Trichinella spp., Toxoplasma, or phocine distemper virus (PDV) were detected (Antarctic fur seals were not tested for PDV antibodies). Antarctic seals are challenged by reduced sea ice and increasing temperatures due to climate change, and increased anthropogenic activity can introduce new pathogens to these vulnerable ecosystems and represent a threat for these animals. Our data provide a baseline for future monitoring of health parameters of these Antarctic seal species, for tracking the impact of environmental, climatic, and anthropogenic changes in Antarctica over time.

  19. New data on Weddell seal (Leptonychotes weddellii colonies: A genetic analysis of a top predator from the Ross Sea, Antarctica.

    Directory of Open Access Journals (Sweden)

    Ighor Antunes Zappes

    Full Text Available In this paper, we studied the genetic variability in Weddell seal from colonies in Terra Nova Bay and Wood Bay, both sites located in the Ross Sea area, Antarctica. Two mitochondrial genes and one nuclear gene, with different mutation rates, were sequenced to investigate the haplotype diversity of the colonies and to test for a possible recent expansion. Fifteen microsatellites were used to analyze their genetic structure. Sequenced genes and microsatellites were also used to estimate the effective population size of the studied colonies and the Ross Sea seal population. The Ross Sea has a high density population of Weddel seals, with an estimated effective number of 50,000 females, and 1,341 individuals for the sampling area, possibly due to its high primary production. The colonies showed high diversity (Hd > 0.90 and many exclusive haplotypes (> 75%, likely a consequence of the surprisingly high site fidelity of Weddell seals, despite the proximity of the colonies. Nevertheless, there was low microsatellite differentiation between colonies, suggesting that they are part of a single larger population. Their expansion seemed to have started during the last glacial cycle (around 58,000 years ago, indicating that the Ross Sea seal populations have been present in the area for long time, probably due to the lack of hunting by humans and terrestrial predation. As a top predator, the role of Weddell seals in the Ross Sea ecology is crucial, and its demographic dynamics should be monitored to follow the future changes of such an important ecosystem.

  20. Coastal polynyas in the southern Weddell Sea: Variability of the surface energy budget

    Science.gov (United States)

    Renfrew, Ian A.; King, John C.; Markus, Thorsten

    2002-06-01

    The surface energy budget of coastal polynyas in the southern Weddell Sea has been evaluated for the period 1992-1998 using a combination of satellite observations, meteorological data, and simple physical models. The study focuses on polynyas that habitually form off the Ronne Ice Shelf. The coastal polynya areal data are derived from an advanced multichannel polynya detection algorithm applied to passive microwave brightness temperatures. The surface sensible and latent heat fluxes are calculated via a fetch-dependent model of the convective-thermal internal boundary layer. The radiative fluxes are calculated using well-established empirical formulae and an innovative cloud model. Standard meteorological variables that are required for the flux calculations are taken from automatic weather stations and from the National Centers for Environmental Production/National Center for Atmospheric Research reanalyses. The 7 year surface energy budget shows an overall oceanic warming due to the presence of coastal polynyas. For most of the period the summertime oceanic warming, due to the absorption of shortwave radiation, is approximately in balance with the wintertime oceanic cooling. However, the anomalously large summertime polynya of 1997-1998 allowed a large oceanic warming of the region. Wintertime freezing seasons are characterized by episodes of high heat fluxes interspersed with more quiescent periods and controlled by coastal polynya dynamics. The high heat fluxes are primarily due to the sensible heat flux component, with smaller complementary latent and radiative flux components. The average freezing season area-integrated energy exchange is 3.48 × 1019 J, with contributions of 63, 22, and 15% from the sensible, latent, and radiative components, respectively. The average melting season area-integrated energy exchange is -5.31 × 1019 J, almost entirely due to the radiative component. There is considerable interannual variability in the surface energy budget

  1. Diel and seasonal patterns of underwater sounds by Weddell seals, leopard seals, and killer whales in the Antarctic: When it's adaptive to be quiet

    Science.gov (United States)

    Mindach, Debrah; Thomas, Jeanette

    2005-09-01

    Automated underwater recordings taken during the austral breeding season of the Weddell seal (Leptonychotes weddellii) in Antarctica also provided data on the vocalizations of predators in the area; leopard seals (Hydrurga leptonyx) and killer whales (Orcinus orca). Weddell seals inhabit fast ice areas to give birth, mate, and molt. Near the end of the breeding season in December the fast ice often breaks out and the two pack ice predators are able to move near the Weddell seal colonies and prey on them, especially pups. Recordings were taken continuously for a 2.5-min period each hour from mid-October 1977 and late-January 1978 at Hutton Cliffs and South Turtle Rock Crack, in McMurdo Sound. The leopard seals increased their trill calls when killer whales came into the area as evidenced by an increase in their frequency-modulated squeak calls. Weddell seals decreased their vocalization rate dramatically (~10 sounds/min) compared to during the peak of the breeding season (~75 sounds/min). Perhaps by being quiet, Weddell seals do not attract predators to their area.

  2. Winter Weather Emergencies

    Science.gov (United States)

    Severe winter weather can lead to health and safety challenges. You may have to cope with Cold related health ... Although there are no guarantees of safety during winter weather emergencies, you can take actions to protect ...

  3. Winter maintenance performance measure.

    Science.gov (United States)

    2016-01-01

    The Winter Performance Index is a method of quantifying winter storm events and the DOTs response to them. : It is a valuable tool for evaluating the States maintenance practices, performing post-storm analysis, training : maintenance personnel...

  4. Winter weather demand considerations.

    Science.gov (United States)

    2015-04-01

    Winter weather has varied effects on travel behavior. Using 418 survey responses from the Northern Virginia : commuting area of Washington, D.C. and binary logit models, this study examines travel related changes under : different types of winter wea...

  5. Distribution patterns of macrozoobenthos: a comparison between the Magellan Region and the Weddell Sea (Antarctic

    Directory of Open Access Journals (Sweden)

    D. Gerdes

    1999-12-01

    Full Text Available The Joint Chilean-German-Italian Magellan Victor Hensen Campaign in October/November 1994 and the Polarstern expedition ANT XIII/4 (May 1996 yielded 207 quantitative multibox corer samples from 11 stations in the Paso Ancho (Magellan Straits, 10 stations in the Beagle Channel, and 15 stations of the shelf and continental slope off the eastern entrance of the Beagle Channel. Mean abundance values in the Magellan Region varied from 1591 Ind. M-2 in the Paso Ancho to 3643 Ind. m-2 in the Beagle Channel and 3983 Ind. m-2 on the shelf; the corresponding biomass values were 96.8 g, 301.6 g, and 119.0 g wet weight m-2 respectively. In terms of org. C the corresponding values are 4.8, 11.4, and 4.6 g m-2. Abundance (3806 Ind. m-2 and biomass (222.6 g wet weight m-2 or 7.3 g C data from the eastern Weddell Sea shelf (Polarstern expeditions ANT VI/3, 1987/88 and ANT VII/4, 1989 are in the same range. The composition of the fauna, however, reveals distinct differences.

  6. Longitudinal variability of organic nutrients in the North Atlantic subtropical gyre

    Science.gov (United States)

    Landolfi, A.; Dietze, H.; Volpe, G.

    2016-05-01

    We combine modelled timescales of ocean circulation with satellite-retrieved and in situ biogeochemical observations collected in spring along 24.5°N in the subtropical North Atlantic. Longitudinal gradients in the distribution of dissolved organic nitrogen (DON) and dissolved organic phosphorus (DOP) and in other biogeochemical parameters are associated with the longitudinal variability in physical forcing and in the eastward increase of the timescale of advective transport. The western (West of 70°W) and eastern (East of 30°W) margins of the subtropical gyre appear influenced by the productive regions of the Gulf Stream and upwelling zones off Africa, respectively. Within the oligotrophic zone between 70 and 31°W, at approximately 46°W there is a change in the nutrient-controlling factors from the western ultraoligotrophic with barely any seasonal cycle to an eastern oligotrophic environment with a more intense mixed layer dynamics. The allochthonous supply of semilabile-DOP may be important in the western sector of the oligotrophic gyre (approx. 70-46°W) where, together with the combination of shallow mixed layers, almost permanent stratification and high water temperatures create a niche for the growth of diazotrophs, which we detect from space. Turnover estimates exceeding 3 yr suggest that even reactive fractions of DON are unlikely to be a significant N source. In the eastern sector of the oligotrophic gyre (46-31°W), transit timescales longer than 3 years suggest that the allochthonous supply of the semilabile DOP is negligible due to its exhaustion. Here, an intense mixed layer dynamics favours nutrient supply from below the mixed layer. We speculate that longitudinal variability in physical forcing and gradients in the timescale of advection, combined with distinct turnover timescales of reactive fractions of DON and DOP, drive diverse phytoplankton assemblages and surface nitrogen fixation gradients across our region of investigation.

  7. Temporal Variability of Trichodesmium spp. and Diatom-Diazotroph Assemblages in the North Pacific Subtropical Gyre

    OpenAIRE

    Angelicque E. White; Katie S. Watkins-Brandt; Matthew J. Church

    2018-01-01

    In oligotrophic ocean regions such as the North Pacific Subtropical Gyre (NPSG), N2 fixation (i.e., diazotrophy) by a diverse consortium of microorganisms has been shown to contribute significantly to new production and particle export. In 2015 and 2016, we measured near-monthly abundances of the large cell-sized (> 10 μm) diazotrophic genera Trichodesmium and diatom-associated Richelia and Calothrix spp. in the NPSG via microscopy and quantitative PCR of nifH genes. Of these genera, we fi...

  8. Winter-to-winter variations in indoor radon

    International Nuclear Information System (INIS)

    Mose, D.G.; Mushrush, G.W.; Kline, S.W.

    1989-01-01

    Indoor radon concentrations in northern Virginia and central Maryland show a strong dependence on weather. Winter tends to be associated with higher than average indoor radon, and summer with lower than average. However, compared to the winter of 1986-1987, the winter of 1987-1988 was warmer and drier. Consequently, winter-to-winter indoor radon decreased by about 25%. This winter-to-winter decrease is unexpectedly large, and simulates winter-to-summer variations that have been reported

  9. Detección de anticuerpos Anti-brucella en focas de Weddell (Leptonychotes weddellii) de Cabo Shirref, Antártica Detection of anti-brucella antibodies in Weddell seals (Leptonychotes weddellii) from cape Shirref, Antarctica

    OpenAIRE

    O. BLANK; P. RETAMAL; P. ABALOS; D. TORRES

    2002-01-01

    Posterior al hallazgo de anticuerpos anti-Brucella en muestras de lobo fino antártico (Arctocephalus gazella), el estudio serológico en Pinnipedia Antárticos se continuó con el fin de determinar la presencia de anticuerpos anti-Brucella en otras especies. Se colectaron muestras de sangre y de fluido extravascular de 12 ejemplares de foca de Weddell (Leptonychotes weddellii) encontrados en el Sitio de Especial Interés Científico (SEIC) Nº 32 y sitio CCAMLR Ecosystem Monitoring Program (CEMP) N...

  10. Chemical immobilization of adult female Weddell seals with tiletamine and zolazepam: effects of age, condition and stage of lactation

    Directory of Open Access Journals (Sweden)

    Harcourt Robert G

    2006-02-01

    Full Text Available Abstract Background Chemical immobilization of Weddell seals (Leptonychotes weddellii has previously been, for the most part, problematic and this has been mainly attributed to the type of immobilizing agent used. In addition to individual sensitivity, physiological status may play an important role. We investigated the use of the intravenous administration of a 1:1 mixture of tiletamine and zolazepam (Telazol® to immobilize adult females at different points during a physiologically demanding 5–6 week lactation period. We also compared performance between IV and IM injection of the same mixture. Results The tiletamine:zolazepam mixture administered intravenously was an effective method for immobilization with no fatalities or pronounced apnoeas in 106 procedures; however, there was a 25 % (one animal in four mortality rate with intramuscular administration. Induction time was slightly longer for females at the end of lactation (54.9 ± 2.3 seconds than at post-parturition (48.2 ± 2.9 seconds. In addition, the number of previous captures had a positive effect on induction time. There was no evidence for effects due to age, condition (total body lipid, stage of lactation or number of captures on recovery time. Conclusion We suggest that intravenous administration of tiletamine and zolazepam is an effective and safe immobilizing agent for female Weddell seals. Although individual traits could not explain variation in recovery time, we suggest careful monitoring of recovery times during longitudinal studies (> 2 captures. We show that physiological pressures do not substantially affect response to chemical immobilization with this mixture; however, consideration must be taken for differences that may exist for immobilization of adult males and juveniles. Nevertheless, we recommend a mass-specific dose of 0.50 – 0.65 mg/kg for future procedures with adult female Weddell seals and a starting dose of 0.50 mg/kg for other age classes and other

  11. Nutrient co-limitation at the boundary of an oceanic gyre

    Science.gov (United States)

    Browning, Thomas J.; Achterberg, Eric P.; Rapp, Insa; Engel, Anja; Bertrand, Erin M.; Tagliabue, Alessandro; Moore, C. Mark

    2017-11-01

    Nutrient limitation of oceanic primary production exerts a fundamental control on marine food webs and the flux of carbon into the deep ocean. The extensive boundaries of the oligotrophic sub-tropical gyres collectively define the most extreme transition in ocean productivity, but little is known about nutrient limitation in these zones. Here we present the results of full-factorial nutrient amendment experiments conducted at the eastern boundary of the South Atlantic gyre. We find extensive regions in which the addition of nitrogen or iron individually resulted in no significant phytoplankton growth over 48 hours. However, the addition of both nitrogen and iron increased concentrations of chlorophyll a by up to approximately 40-fold, led to diatom proliferation, and reduced community diversity. Once nitrogen-iron co-limitation had been alleviated, the addition of cobalt or cobalt-containing vitamin B12 could further enhance chlorophyll a yields by up to threefold. Our results suggest that nitrogen-iron co-limitation is pervasive in the ocean, with other micronutrients also approaching co-deficiency. Such multi-nutrient limitations potentially increase phytoplankton community diversity.

  12. Gooseneck barnacles (Lepas spp. ingest microplastic debris in the North Pacific Subtropical Gyre

    Directory of Open Access Journals (Sweden)

    Miriam C. Goldstein

    2013-10-01

    Full Text Available Substantial quantities of small plastic particles, termed “microplastic,” have been found in many areas of the world ocean, and have accumulated in particularly high densities on the surface of the subtropical gyres. While plastic debris has been documented on the surface of the North Pacific Subtropical Gyre (NPSG since the early 1970s, the ecological implications remain poorly understood. Organisms associated with floating objects, termed the “rafting assemblage,” are an important component of the NPSG ecosystem. These objects are often dominated by abundant and fast-growing gooseneck barnacles (Lepas spp., which predate on plankton and larval fishes at the sea surface. To assess the potential effects of microplastic on the rafting community, we examined the gastrointestinal tracts of 385 barnacles collected from the NPSG for evidence of plastic ingestion. We found that 33.5% of the barnacles had plastic particles present in their gastrointestinal tract, ranging from one plastic particle to a maximum of 30 particles. Particle ingestion was positively correlated to capitulum length, and no blockage of the stomach or intestines was observed. The majority of ingested plastic was polyethylene, with polypropylene and polystyrene also present. Our results suggest that barnacle ingestion of microplastic is relatively common, with unknown trophic impacts on the rafting community and the NPSG ecosystem.

  13. Extending the capability of GYRE to calculate tidally forced stellar oscillations

    Science.gov (United States)

    Guo, Zhao; Gies, Douglas R.

    2016-01-01

    Tidally forced oscillations have been observed in many eccentric binary systems, such as KOI-54 and many other 'heart beat stars'. The tidal response of the star can be calculated by solving a revised stellar oscillations equations.The open-source stellar oscillation code GYRE (Townsend & Teitler 2013) can be used to solve the free stellar oscillation equations in both adiabatic and non-adiabatic cases. It uses a novel matrix exponential method which avoids many difficulties of the classical shooting and relaxation method. The new version also includes the effect of rotation in traditional approximation.After showing the code flow of GYRE, we revise its subroutines and extend its capability to calculate tidallyforced oscillations in both adiabatic and non-adiabatic cases following the procedure in the CAFein code (Valsecchi et al. 2013). In the end, we compare the tidal eigenfunctions with those calculated from CAFein.More details of the revision and a simple version of the code in MATLAB can be obtained upon request.

  14. Gooseneck barnacles (Lepas spp.) ingest microplastic debris in the North Pacific Subtropical Gyre.

    Science.gov (United States)

    Goldstein, Miriam C; Goodwin, Deborah S

    2013-01-01

    Substantial quantities of small plastic particles, termed "microplastic," have been found in many areas of the world ocean, and have accumulated in particularly high densities on the surface of the subtropical gyres. While plastic debris has been documented on the surface of the North Pacific Subtropical Gyre (NPSG) since the early 1970s, the ecological implications remain poorly understood. Organisms associated with floating objects, termed the "rafting assemblage," are an important component of the NPSG ecosystem. These objects are often dominated by abundant and fast-growing gooseneck barnacles (Lepas spp.), which predate on plankton and larval fishes at the sea surface. To assess the potential effects of microplastic on the rafting community, we examined the gastrointestinal tracts of 385 barnacles collected from the NPSG for evidence of plastic ingestion. We found that 33.5% of the barnacles had plastic particles present in their gastrointestinal tract, ranging from one plastic particle to a maximum of 30 particles. Particle ingestion was positively correlated to capitulum length, and no blockage of the stomach or intestines was observed. The majority of ingested plastic was polyethylene, with polypropylene and polystyrene also present. Our results suggest that barnacle ingestion of microplastic is relatively common, with unknown trophic impacts on the rafting community and the NPSG ecosystem.

  15. Jurassic high heat production granites associated with the Weddell Sea rift system, Antarctica

    Science.gov (United States)

    Leat, Philip T.; Jordan, Tom A.; Flowerdew, Michael J.; Riley, Teal R.; Ferraccioli, Fausto; Whitehouse, Martin J.

    2018-01-01

    The distribution of heat flow in Antarctic continental crust is critical to understanding continental tectonics, ice sheet growth and subglacial hydrology. We identify a group of High Heat Production granites, intruded into upper crustal Palaeozoic metasedimentary sequences, which may contribute to locally high heat flow beneath the West Antarctic Ice Sheet. Four of the granite plutons are exposed above ice sheet level at Pagano Nunatak, Pirrit Hills, Nash Hills and Whitmore Mountains. A new Usbnd Pb zircon age from Pirrit Hills of 178.0 ± 3.5 Ma confirms earlier Rbsbnd Sr and Usbnd Pb dating and that the granites were emplaced approximately coincident with the first stage of Gondwana break-up and the developing Weddell rift, and 5 m.y. after eruption of the Karoo-Ferrar large igneous province. Aerogeophysical data indicate that the plutons are distributed unevenly over 40,000 km2 with one intruded into the transtensional Pagano Shear Zone, while the others were emplaced within the more stable Ellsworth-Whitmore mountains continental block. The granites are weakly peraluminous A-types and have Th and U abundances up to 60.7 and 28.6 ppm respectively. Measured heat production of the granite samples is 2.96-9.06 μW/m3 (mean 5.35 W/m3), significantly higher than average upper continental crust and contemporaneous silicic rocks in the Antarctic Peninsula. Heat flow associated with the granite intrusions is predicted to be in the range 70-95 mW/m2 depending on the thickness of the high heat production granite layer and the regional heat flow value. Analysis of detrital zircon compositions and ages indicates that the high Th and U abundances are related to enrichment of the lower-mid crust that dates back to 200-299 Ma at the time of the formation of the Gondwanide fold belt and its post-orogenic collapse and extension.

  16. Heat loss in air of an Antarctic marine mammal, the Weddell seal.

    Science.gov (United States)

    Mellish, Jo-Ann; Hindle, Allyson; Skinner, John; Horning, Markus

    2015-01-01

    The conflicting needs of homeostasis in air versus water complicate our understanding of thermoregulation in marine mammals. Large-scale modeling efforts directed at predicting the energetic impact of changing sea ice conditions on polar ecosystems require a better understanding of thermoregulation in air of free-ranging animals. We utilized infrared imaging as an indirect approach to determine surface temperatures of dry, hauled-out Weddell seals (Leptonychotes weddellii, n = 35) of varying age and body condition during the Antarctic summer. The study groups provided a fivefold range in body mass and a threefold range in blubber depth. Surface temperature (T s) did not vary by body region (head, shoulder, axilla, torso, hip, flippers). Average seal T s (mean 13.9 ± 11.2 °C) was best described through a combination of the physical traits of body mass and environmental variables of ambient temperature T air, and wind speed. Additional factors of ice temperature (T ice), relative humidity and cloud cover did not improve the model. Heat transfer model estimates suggested that radiation contributed 56.6 ± 7.7 % of total heat loss. Convection and conduction accounted for the remaining 15.7 ± 12.3 and 27.7 ± 9.3 %, respectively. Heat loss by radiation was primarily influenced by body mass and wind speed, whereas convective heat loss was influenced primarily by blubber depth and wind speed. Conductive heat loss was modeled largely as a function of physical traits of mass and blubber depth rather than any environmental covariates, and therefore was substantially higher in animals in leaner condition.

  17. A High-Resolution Model of Water Mass Transformation and Transport in the Weddell Sea

    Science.gov (United States)

    Hazel, J.; Stewart, A.

    2016-12-01

    The ocean circulation around the Antarctic margins has a pronounced impact on the global ocean and climate system. One of these impacts includes closing the global meridional overturning circulation (MOC) via formation of dense Antarctic Bottom Water (AABW), which ventilates a large fraction of the subsurface ocean. AABW is also partially composed of modified Circumpolar Deep Water (CDW), a warm, mid-depth water mass whose transport towards the continent has the potential to induce rapid retreat of marine-terminating glaciers. Previous studies suggest that these water mass exchanges may be strongly influenced by high-frequency processes such as downslope gravity currents, tidal flows, and mesoscale/submesoscale eddy transport. However, evaluating the relative contributions of these processes to near-Antarctic water mass transports is hindered by the region's relatively small scales of motion and the logistical difficulties in taking measurements beneath sea ice.In this study we develop a regional model of the Weddell Sea, the largest established source of AABW. The model is forced by an annually-repeating atmospheric state constructed from the Antarctic Mesoscale Prediction System data and by annually-repeating lateral boundary conditions constructed from the Southern Ocean State Estimate. The model incorporates the full Filchner-Ronne cavity and simulates the thermodynamics and dynamics of sea ice. To analyze the role of high-frequency processes in the transport and transformation of water masses, we compute the model's overturning circulation, water mass transformations, and ice sheet basal melt at model horizontal grid resolutions ranging from 1/2 degree to 1/24 degree. We temporally decompose the high-resolution (1/24 degree) model circulation into components due to mean, eddy and tidal flows and discuss the geographical dependence of these processes and their impact on water mass transformation and transport.

  18. Tidal influences on a future evolution of the Filchner-Ronne Ice Shelf cavity in the Weddell Sea, Antarctica

    Science.gov (United States)

    Mueller, Rachael D.; Hattermann, Tore; Howard, Susan L.; Padman, Laurie

    2018-02-01

    Recent modeling studies of ocean circulation in the southern Weddell Sea, Antarctica, project an increase over this century of ocean heat into the cavity beneath Filchner-Ronne Ice Shelf (FRIS). This increase in ocean heat would lead to more basal melting and a modification of the FRIS ice draft. The corresponding change in cavity shape will affect advective pathways and the spatial distribution of tidal currents, which play important roles in basal melting under FRIS. These feedbacks between heat flux, basal melting, and tides will affect the evolution of FRIS under the influence of a changing climate. We explore these feedbacks with a three-dimensional ocean model of the southern Weddell Sea that is forced by thermodynamic exchange beneath the ice shelf and tides along the open boundaries. Our results show regionally dependent feedbacks that, in some areas, substantially modify the melt rates near the grounding lines of buttressed ice streams that flow into FRIS. These feedbacks are introduced by variations in meltwater production as well as the circulation of this meltwater within the FRIS cavity; they are influenced locally by sensitivity of tidal currents to water column thickness (wct) and non-locally by changes in circulation pathways that transport an integrated history of mixing and meltwater entrainment along flow paths. Our results highlight the importance of including explicit tidal forcing in models of future mass loss from FRIS and from the adjacent grounded ice sheet as individual ice-stream grounding zones experience different responses to warming of the ocean inflow.

  19. On the forcing mechanisms of mesocyclones in the eastern Weddell Sea region, Antarctica: Process studies using a mesoscale numerical model

    Directory of Open Access Journals (Sweden)

    Thomas Klein

    2001-04-01

    Full Text Available Development mechanisms of Antarctic mesocyclones in the eastern Weddell Sea area are examined by means of simulations with a mesoscale model using different idealized initial conditions. In one of the experiments, a mesocyclone develops over an area of open water close to the coast of the Antarctic continent. The forcing mechanisms of this mesocyclogenesis are investigated by means of sensitivity studies in which certain physical processes and the relevance of the surface conditions topography, sea surface temperature and sea ice coverage are examined. The sensitivity experiments show that the simulated mesocyclone is forced by an interaction of several forcing mechanisms at different stages of the development rather than by a single mechanism. The topography of the eastern Weddell Sea region and the summertime coastal polynia are shown to be of great importance for the mesocyclogenesis. A suitable synoptic-scale flow is necessary to support the katabatic flow over the sloped ice sheet, and to enhance the generation of cyclonic vorticity due to vertical stretching for the initial mesocyclogenesis. The diabatic process of the convergence of the sensible and latent heat fluxes in the boundary layer over the coastal polynia then becomes the dominant forcing mechanism for the further development of the mesocyclone.

  20. Interaction of additive noise and nonlinear dynamics in the double-gyre wind-driven ocean circulation

    NARCIS (Netherlands)

    Sapsis, T.; Dijkstra, H.A.

    2013-01-01

    In this paper the authors study the interactions of additive noise and nonlinear dynamics in a quasi-geostrophicmodel of the double-gyre wind-driven ocean circulation. The recently developed framework of dynamically orthogonal field theory is used to determine the statistics of the flows that arise

  1. Factors controlling phytoplankton ice-edge blooms in the marginal ice-zone of the northwestern Weddell Sea during sea ice retreat 1988 : field observations and mathematical modelling

    NARCIS (Netherlands)

    Lancelot, Christiane; Mathot, Sylvie; Veth, Cornelis; Baar, Hein de

    1993-01-01

    The factors controlling phytoplankton bloom development in the marginal ice zone of the northwestern Weddell Sea were investigated during the EPOS (Leg 2) expedition (1988). Measurements were made of physical and chemical processes and biological activities associated with the process of ice-melting

  2. The impact of gyre dynamics on the mid-depth salinity signature of the eastern North Atlantic

    Science.gov (United States)

    Burkholder, K. C.; Lozier, M. S.

    2009-04-01

    The Mediterranean Overflow Water (MOW) is widely recognized for its role in establishing the mid-depth salinity signature of the subtropical North Atlantic. However, recent work has revealed an intermittent impact of MOW on the salinity signature of the eastern subpolar basin. This impact results from a temporally variable penetration of the northward flowing branch of the MOW past Porcupine Bank into the eastern subpolar basin. It has been shown that the salinity signature of the eastern subpolar basin, in particular the Rockall Trough, varies with the state of the North Atlantic Oscillation (NAO): during persistent periods of strong winds (high NAO index), when the subpolar front moves eastward, waters in the subpolar gyre block the northward flowing MOW, preventing its entry into the subpolar gyre. Conversely, during persistent periods of weak winds (low NAO index), the front moves westward, allowing MOW to penetrate north of Porcupine Bank and into the subpolar gyre. Here, we investigate the manner in which the spatial and temporal variability in the northward penetration of the MOW and the position of the eastern limb of the subpolar front affect the mid-depth property fields not only in the subpolar gyre, but in the subtropical gyre as well. Using approximately 55 years of historical hydrographic data and output from the 1/12° FLAME model, we analyze the temporal variability of salinity along the eastern boundary and compare this variability to the position of the subpolar front in both the observational record and the FLAME model. We conclude that when the zonal position of the subpolar front moves relatively far offshore and the MOW is able to penetrate to the north, high salinity anomalies are observed at high latitudes and low salinity anomalies are observed at low latitudes. Conversely, when the frontal position shifts to the east, the MOW (and thus, the high salinity signature) is blocked, resulting in a drop in salinity anomalies at high latitudes

  3. Modelling Ecosystem Dynamics of the Oxygen Minimum Zones in the Angola Gyre and the Northern Benguela Upwelling System.

    Science.gov (United States)

    Schmidt, M.; Eggert, A.

    2016-02-01

    The Angola Gyre and the Northern Benguela Upwelling System are two major oxygen minimum zones (OMZ) of different kind connected by the system of African Eastern Boundary Currents. We discuss results from a 3-dimensional coupled biogeochemical model covering both oxygen-deficient systems. The biogeochemical model component comprises trophic levels up to zooplankton. Physiological properties of organisms are parameterized from field data gained mainly in the course of the project "Geochemistry and Ecology of the Namibian Upwelling System" (GENUS). The challenge of the modelling effort is the different nature of both systems. The Angola Gyre, located in a "shadow zone" of the tropical Atlantic, has a low productivity and little ventilation, hence a long residence time of water masses. In the northern Benguela Upwelling System, trade winds drive an intermittent, but permanent nutrient supply into the euphotic zone which fuels a high coastal productivity, large particle export and high oxygen consumption from dissimilatory processes. In addition to the local processes, oxygen-deficient water formed in the Angola Gyre is one of the source water masses of the poleward undercurrent, which feeds oxygen depleted water into the Benguela system. In order to simulate the oxygen distribution in the Benguela system, both physical transport as well as local biological processes need to be carefully adjusted in the model. The focus of the analysis is on the time scale and the relative contribution of the different oxygen related processes to the oxygen budgets in both the oxygen minimum zones. Although these are very different in both the OMZ, the model is found as suitable to produce oxygen minimum zones comparable with observations in the Benguela and the Angola Gyre as well. Variability of the oxygen concentration in the Angola Gyre depends strongly on organismic oxygen consumption, whereas the variability of the oxygen concentration on the Namibian shelf is governed mostly by

  4. Gradients in microbial methanol uptake: productive coastal upwelling waters to oligotrophic gyres in the Atlantic Ocean

    Science.gov (United States)

    Dixon, Joanna L; Sargeant, Stephanie; Nightingale, Philip D; Colin Murrell, J

    2013-01-01

    Methanol biogeochemistry and its importance as a carbon source in seawater is relatively unexplored. We report the first microbial methanol carbon assimilation rates (k) in productive coastal upwelling waters of up to 0.117±0.002 d−1 (∼10 nmol l−1 d−1). On average, coastal upwelling waters were 11 times greater than open ocean northern temperate (NT) waters, eight times greater than gyre waters and four times greater than equatorial upwelling (EU) waters; suggesting that all upwelling waters upon reaching the surface (⩽20 m), contain a microbial population that uses a relatively high amount of carbon (0.3–10 nmol l−1 d−1), derived from methanol, to support their growth. In open ocean Atlantic regions, microbial uptake of methanol into biomass was significantly lower, ranging between 0.04–0.68 nmol l−1 d−1. Microbes in the Mauritanian coastal upwelling used up to 57% of the total methanol for assimilation of the carbon into cells, compared with an average of 12% in the EU, and 1% in NT and gyre waters. Several methylotrophic bacterial species were identified from open ocean Atlantic waters using PCR amplification of mxaF encoding methanol dehydrogenase, the key enzyme in bacterial methanol oxidation. These included Methylophaga sp., Burkholderiales sp., Methylococcaceae sp., Ancylobacter aquaticus, Paracoccus denitrificans, Methylophilus methylotrophus, Methylobacterium oryzae, Hyphomicrobium sp. and Methylosulfonomonas methylovora. Statistically significant correlations for upwelling waters between methanol uptake into cells and both chlorophyll a concentrations and methanol oxidation rates suggest that remotely sensed chlorophyll a images, in these productive areas, could be used to derive total methanol biological loss rates, a useful tool for atmospheric and marine climatically active gas modellers, and air–sea exchange scientists. PMID:23178665

  5. Time dependency of the prediction skill for the North Atlantic subpolar gyre in initialized decadal hindcasts

    Science.gov (United States)

    Brune, Sebastian; Düsterhus, André; Pohlmann, Holger; Müller, Wolfgang A.; Baehr, Johanna

    2017-11-01

    We analyze the time dependency of decadal hindcast skill in the North Atlantic subpolar gyre within the time period 1961-2013. We compare anomaly correlation coefficients and temporal interquartile ranges of total upper ocean heat content and sea surface temperature for three differently initialized sets of hindcast simulations with the global coupled model MPI-ESM. All initializations use weakly coupled assimilation with the same full value nudging in the atmospheric component and different assimilation techniques for oceanic temperature and salinity: (1) ensemble Kalman filter assimilating EN4 observations and HadISST data, (2) nudging of anomalies to ORAS4 reanalysis, (3) nudging of full values to ORAS4 reanalysis. We find that hindcast skill depends strongly on the evaluation time period, with higher hindcast skill during strong multiyear trends, especially during the warming in the 1990s and lower hindcast skill in the absence of such trends. Differences between the prediction systems are more pronounced when investigating any 20-year subperiod within the entire hindcast period. In the ensemble Kalman filter initialized hindcasts, we find significant correlation skill for up to 5-8 lead years, albeit along with an overestimation of the temporal interquartile range. In the hindcasts initialized by anomaly nudging, significant correlation skill for lead years greater than two is only found in the 1980s and 1990s. In the hindcasts initialized by full value nudging, correlation skill is consistently lower than in the hindcasts initialized by anomaly nudging in the first lead years with re-emerging skill thereafter. The Atlantic meridional overturning circulation reacts on the density changes introduced by oceanic nudging, this limits the predictability in the subpolar gyre in the first lead years. Overall, we find that a model-consistent assimilation technique can improve hindcast skill. Further, the evaluation of 20 year subperiods within the full hindcast period

  6. Environmental correlates of temporary emigration for female Weddell seals and consequences for recruitment

    Science.gov (United States)

    Stauffer, Glenn E.; Rotella, Jay J.; Garrott, Robert A.; Kendall, William L.

    2014-01-01

    In colonial-breeding species, prebreeders often emigrate temporarily from natal reproductive colonies then subsequently return for one or more years before producing young. Variation in attendance–nonattendance patterns can have implications for subsequent recruitment. We used open robust-design multistate models and 28 years of encounter data for prebreeding female Weddell seals (Leptonychotes weddellii [Lesson]) to evaluate hypotheses about (1) the relationships of temporary emigration (TE) probabilities to environmental and population size covariates and (2) motivations for attendance and consequences of nonattendance for subsequent probability of recruitment to the breeding population. TE probabilities were density dependent (βˆBPOP = 0.66,  = 0.17; estimated effects [β] and standard errors of population size in the previous year) and increased when the fast-ice edge was distant from the breeding colonies (βˆDIST = 0.75,  = 0.04; estimated effects and standard errors of distance to the sea-ice edge in the current year on TE probability in the current year) and were strongly age and state dependent. These results suggest that trade-offs between potential benefits and costs of colony attendance vary annually and might influence motivation to attend colonies. Recruitment probabilities were greatest for seals that consistently attended colonies in two or more years (e.g.,  = 0.56, SD = 0.17) and lowest for seals that never or inconsistently attended prior to recruitment (e.g.,  = 0.32, SD = 0.15), where denotes the mean recruitment probability (over all years) for 10-year-old seals for the specified prebreeder state. In colonial-breeding seabirds, repeated colony attendance increases subsequent probability of recruitment to the adult breeding population; our results suggest similar implications for a marine mammal and are consistent with the hypothesis that prebreeders were motivated to attend reproductive colonies to gain reproductive skills or

  7. Asteroids, ophiuroids and holothurians from the southeastern Weddell Sea (Southern Ocean

    Directory of Open Access Journals (Sweden)

    Julian Gutt

    2014-08-01

    Full Text Available Until the early 1980s, the composition and distribution of the asteroid (starfish, ophiuroid (brittle star and holothurian (sea cucumber bottom fauna of the southeastern Weddell Sea was virtually unknown. This southernmost part of the Atlantic sector of the Southern Ocean is a typical high-latitude Antarctic region located in the circumpolar permanent pack-ice zone. It became accessible for large-scale scientific surveys only through the availability of modern ice-breaking research vessels, such as the German RV “Polarstern”. Here, we describe a dataset of the faunal composition and abundance of starfish, brittle star and sea cucumber assemblages in this area, based on collections from trawl catches carried out during three “Polarstern” cruises in 1983, 1984 and 1985. The set comprises a total of 4,509 records of abundances of 35 asteroid species (with a total of 2,089 specimens and 38 ophiuroid species (with a total of 18,484 specimens from 34 stations, as well as of 66 holothurian species (with a total of 20,918 specimens from 59 stations including zero-abundances (absences. A synthesizing zoogeographical community analysis confirms the presence of three distinct assemblages of asteroids, ophiuroids, and holothurians with highest species richness on the eastern shelf. Overall, starfishes, brittle stars and sea cucumbers were present at all sites investigated in the study area but composition and abundance of asterozoan (asteroids and ophiuroids together and holothurian fauna varied considerably. A synthesizing zoogeographical community analysis confirms the presence of three distinct assemblages of asteroids, ophiuroids, and holothurians with highest species richness on the eastern shelf. In the case of asterozoans, water depth and latitude seemed to be the most important drivers of assemblage distribution and composition. One of the holothurian assemblages was part of the rich macrozoobenthic community dominated by a diverse and

  8. Winters fuels report

    International Nuclear Information System (INIS)

    1995-01-01

    The outlook for distillate fuel oil this winter is for increased demand and a return to normal inventory patterns, assuming a resumption of normal, cooler weather than last winter. With industrial production expected to grow slightly from last winter's pace, overall consumption is projected to increase 3 percent from last winter, to 3.4 million barrels per day during the heating season (October 1, 1995-March 31, 1996). Much of the supply win come from stock drawdowns and refinery production. Estimates for the winter are from the Energy Information Administration's (EIA) 4th Quarter 1995 Short-Tenn Energy Outlook (STEO) Mid-World Oil Price Case forecast. Inventories in place on September 30, 1995, of 132 million barrels were 9 percent below the unusually high year-earlier level. Inventories of high-sulfur distillate fuel oil, the principal type used for heating, were 13 percent lower than a year earlier. Supply problems are not anticipated because refinery production and the ready availability of imports should be adequate to meet demand. Residential heating off prices are expected to be somewhat higher than last winter's, as the effects of lower crude oil prices are offset by lower distillate inventories. Heating oil is forecast to average $0.92 per gallon, the highest price since the winter of 1992-93. Diesel fuel (including tax) is predicted to be slightly higher than last year at $1.13 per gallon. This article focuses on the winter assessment for distillate fuel oil, how well last year's STEO winter outlook compared to actual events, and expectations for the coming winter. Additional analyses include regional low-sulfur and high-sulfur distillate supply, demand, and prices, and recent trends in distillate fuel oil inventories

  9. Physical and chemical data collected using bottle casts from the GENERAL SAN MARTIN in the Scotia Sea and Weddell Sea from 14 December 1963 to 11 January 1964 (NODC Accession 0000791)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Physical and chemical data were collected using bottle casts in the Scotia Sea and Weddell Sea from the GENERAL SAN MARTIN. Data were collected from 14 December 1963...

  10. Employment and winter construction

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place; Larsen, Jacob Norvig

    2011-01-01

    Reduced seasonal building activity in the construction sector is often assumed to be related to hard winter conditions for building activities and poor working conditions for construction workers, resulting in higher costs and poor quality of building products, particularly in the northern...... hemisphere. Can climatic conditions alone explain the sizeable difference in reduction in building activity in the construction sector in European countries in the winter months, or are other factors such as technology, economic cycles and schemes for financial compensation influential as well? What...... possibilities exist for reducing seasonal variation in employment? In addition to a literature review related to winter construction, European and national employment and meteorological data were studied. Finally, ministerial acts, ministerial orders or other public policy documents related to winter...

  11. Deer Wintering Areas

    Data.gov (United States)

    Vermont Center for Geographic Information — Deer winter habitat is critical to the long term survival of white-tailed deer (Odocoileus virginianus) in Vermont. Being near the northern extreme of the...

  12. Winter Bottom Trawl Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The standardized NEFSC Winter Bottom Trawl Survey was initiated in 1992 and covered offshore areas from the Mid-Atlantic to Georges Bank. Inshore strata were covered...

  13. Beaufort Gyre hydrographic data: Temperature, salinity and transmissivity data from the Louis S St. Laurent in the Arctic Ocean, 2003 - 2008 (NODC Accession 0058268)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The major goal of the observational program is to determine the variability of different components of the Beaufort Gyre fresh water (ocean and sea ice) system and...

  14. Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from GYRE in the Gulf of Mexico from 1990-02-19 to 1990-02-24 (NODC Accession 9000098)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data in this accession was collected in the Gulf of Mexico using the R/V Gyre in February 1990 under the Texas Institutions Gulf Ecosystem Research (TIGER)...

  15. Cloud amount/frequency, NITRATE and other data from GYRE in the Gulf of Mexico from 1990-07-11 to 1990-07-23 (NODC Accession 9000225)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Conductivity, Temperature and Depth (CTD) and other data were collected from Gulf of Mexico. R/V Gyre was used to collect data by Texas A&M University,...

  16. Diving into old age: muscular senescence in a large-bodied, long-lived mammal, the Weddell seal (Leptonychotes weddellii).

    Science.gov (United States)

    Hindle, Allyson G; Horning, Markus; Mellish, Jo-Ann E; Lawler, John M

    2009-03-01

    Classic aging theory postulates the absence of pronounced organismal senescence in wild animals since mortality probably occurs first. Large-bodied, long-lived mammals are a recognized exception to this tenet, yet organismal senescence has not been investigated to date in such mammals in the wild. Furthermore, oxidative stress theory of aging supports the suggestion that exercise hypoxia, as regularly incurred during apneustic foraging in diving mammals might lead to cellular dysfunction and accelerated aging. To determine if an aspect of organismal senescence occurs in wild marine mammals, we examined the pattern of skeletal muscle aging (contractile and connective tissue components of longissimus dorsi and pectoralis muscles) in free-ranging adult Weddell seals (9-26 years). The average myocyte cross-sectional area was 22% greater with age in the longissiums dorsi, but no significant increase occurred in the pectoralis. Cross-sectional area was not related to body mass. Changes in myocyte number per area were consistent with the 35-40% age-increase in extracellular space in both muscle groups. Also consistent with extracellular space remodeling, total and relative collagen contents were significantly elevated in older seals (115% in longissimus dorsi; 65% in pectoralis). The ratio of muscle myocyte to collagen declined with age (50-63%) at both sites. Additionally, a shift towards a higher ratio of type I to type III collagen occurred with advancing age in both muscle groups (79% increase in pectoralis; 49% in longissimus dorsi). We reject the classic tenet and null-hypothesis that Weddell seals do not survive to an age where muscular senescence becomes detectable.

  17. Oceanographic and topographic conditions structure benthic meiofauna communities in the Weddell Sea, Bransfield Strait and Drake Passage (Antarctic)

    Science.gov (United States)

    Veit-Köhler, Gritta; Durst, Stephan; Schuckenbrock, Jan; Hauquier, Freija; Durán Suja, Laura; Dorschel, Boris; Vanreusel, Ann; Martínez Arbizu, Pedro

    2018-03-01

    The marine environment of the tip of the Antarctic Peninsula is characterised by three oceanographically distinct regions for which we linked continental-slope meiofaunal patterns and environmental drivers on a large scale (100-300 km among ecoregions). Samples for meiofauna communities and sediment analyses were collected with a multicorer, water-column data were derived from water samples and CTD recordings. Meiofauna communities including individuals from 19 higher taxa were compared to a set of 16 environmental variables. We detected significant differences between the communities of Weddell Sea and those of Bransfield Strait and Drake Passage. The amount of phytopigments in the sediment, their freshness and the silt and clay content were driving factors for this separation. The highest meiofauna abundances were found at slopes in the Weddell Sea. Food banks may facilitate high standing stocks. There, the highest ever recorded copepod percentages for the Antarctic were related to the highest phytopigment contents while nematodes were extremely abundant even in deeper sediment layers at stations with fresh organic material. For Bransfield Strait and Drake Passage a sampling scheme of slopes and adjacent troughs was applied. The two regions were divided into three geographical "areas" with the two "habitat" types investigated for each area. Multivariate non-parametric permutational analysis of variance (PERMANOVA) showed that in Bransfield Strait slope and trough meiofauna communities differed significantly in all geographical areas while in Drake Passage this was only the case in the East. These differences were explained best by the regionally and topographically distinct characteristics of 7 out of 11 water-column and sediment-bound factors related to sediment grain size, food quantity and quality, water temperature and salinity. Environmental drivers of the benthic habitat are dependent on large-scale oceanographic conditions and are thus sensitive to changes

  18. Tidal influences on a future evolution of the Filchner–Ronne Ice Shelf cavity in the Weddell Sea, Antarctica

    Directory of Open Access Journals (Sweden)

    R. D. Mueller

    2018-02-01

    Full Text Available Recent modeling studies of ocean circulation in the southern Weddell Sea, Antarctica, project an increase over this century of ocean heat into the cavity beneath Filchner–Ronne Ice Shelf (FRIS. This increase in ocean heat would lead to more basal melting and a modification of the FRIS ice draft. The corresponding change in cavity shape will affect advective pathways and the spatial distribution of tidal currents, which play important roles in basal melting under FRIS. These feedbacks between heat flux, basal melting, and tides will affect the evolution of FRIS under the influence of a changing climate. We explore these feedbacks with a three-dimensional ocean model of the southern Weddell Sea that is forced by thermodynamic exchange beneath the ice shelf and tides along the open boundaries. Our results show regionally dependent feedbacks that, in some areas, substantially modify the melt rates near the grounding lines of buttressed ice streams that flow into FRIS. These feedbacks are introduced by variations in meltwater production as well as the circulation of this meltwater within the FRIS cavity; they are influenced locally by sensitivity of tidal currents to water column thickness (wct and non-locally by changes in circulation pathways that transport an integrated history of mixing and meltwater entrainment along flow paths. Our results highlight the importance of including explicit tidal forcing in models of future mass loss from FRIS and from the adjacent grounded ice sheet as individual ice-stream grounding zones experience different responses to warming of the ocean inflow.

  19. Geochemically tracking provenance changes in marine sediment from the South Pacific Gyre throughout the Cenozoic

    Science.gov (United States)

    Dunlea, A. G.; Murray, R. W.; Sauvage, J.; Spivack, A. J.; Harris, R. N.; D'Hondt, S. L.

    2012-12-01

    The South Pacific Gyre (SPG), characterized by extremely slow sedimentation rates, is the world's largest oceanic desert. The little eolian dust from continents in the Southern Hemisphere must traverse great distances to reach the SPG, and the ultra-oligotrophic waters minimize the biogenic flux of sediment to the seafloor. However sparse, the pelagic sediment that is ultimately found on the seafloor retains a chemical record that can be used to trace its origin. Using cores from Integrated Ocean Drilling Program Expedition 329, we trace downcore fluctuations in major, trace, and rare earth element (REE) composition and flux to yield clues to the geological, chemical, and biological evolution of the SPG throughout the Cenozoic. The shipboard scientific party generally described the completely oxic, brown pelagic clays recovered during Exp. 329 as zeolitic metalliferous clay. The homogenous, very fine-grained nature of these sediments speaks to the challenges we face in resolving eolian detrital material ("dust"), fine-grained ash (commonly altered), and authigenic aluminosilicates from one another. Based on ICP-ES and ICP-MS analyses followed by multivariate statistical treatments, we are developing chemical records from a number of sites located throughout the SPG. Building on earlier work at DSDP Site 596 (Zhou and Kyte, 1992, Paleocean., 7, 441-465), and based on backtrack paths from 100 Ma forward, we are working to construct a regionally and temporally continuous paleoclimatological history of the SPG. Preliminary La-Th-Sc concentrations from Sites U1367, U1368, and U1369 show a distinct authigenic influence, but several refractory elements retain their original provenance signature. Sediment ages are constrained using a constant-Co model, based on the geochemically similar work that Zhou and Kyte (1992) performed in the SPG. REE concentrations normalized to post-archean average shale (PAAS) reveal a negative Ce anomaly that becomes more pronounced closer to

  20. Nitrous oxide distribution and its origin in the central and eastern South Pacific Subtropical Gyre

    Directory of Open Access Journals (Sweden)

    J. Charpentier

    2007-09-01

    Full Text Available The mechanisms of microbial nitrous oxide (N2O production in the ocean have been the subject of many discussions in recent years. New isotopomeric tools can further refine our knowledge of N2O sources in natural environments. This study compares hydrographic, N2O concentration, and N2O isotopic and isotopomeric data from three stations along a coast-perpendicular transect in the South Pacific Ocean, extending from the center (Sts. GYR and EGY of the subtropical oligotrophic gyre (~26° S; 114° W to the upwelling zone (St. UPX off the central Chilean coast (~34° S. Although AOU/N2O and NO3 trends support the idea that most of the N2O (mainly from intermediate water (200–600 m comes from nitrification, N2O isotopomeric composition (intramolecular distribution of 15N isotopes expressed as SP (site preference of 15N shows low values (10 to 12permil that could be attributed to the production through of microbial nitrifier denitrification (reduction of nitrite to N2O mediated by ammonium oxidizers. The coincidence of this SP signal with high – stability layer, where sinking organic particles can accumulate, suggests that N2O could be produced by nitrifier denitrification inside particles. It is postulated that deceleration of particles in the pycnocline can modify the advection - diffusion balance inside particles, allowing the accumulation of nitrite and O2 depletion suitable for nitrifier denitrication. As lateral advection seems to be relatively insignificant in the gyre, in situ nitrifier denitrification could account for 40–50% of the N2O produced in this layer. In contrast, coastal upwelling system is characterized by O2 deficient condition and some N deficit in a eutrophic system. Here, N2O accumulates up to 480% saturation, and isotopic and

  1. Escaping the oligotrophic gyre? The year-round movements, foraging behaviour and habitat preferences of Murphy’s petrels

    OpenAIRE

    Clay, Thomas A.; Phillips, Richard A.; Manica, Andrea; Jackson, Hazel A.; Brooke, M. de L.

    2017-01-01

    The South Pacific Gyre is the world’s largest expanse of oligotrophic ocean and supports communities of endemic gadfly petrels Pterodroma spp., yet little is known about their foraging ecology in this nutrient-poor environment. We tracked Murphy’s petrels Pterodroma ultima with geolocators from Henderson Island, Pitcairn Islands, for 2 consecutive years (2011 to 2013). During pre-laying exodus, petrels travelled south and southwest of the colony, with males travelling further than females to ...

  2. The Sub-Polar Gyre Index - a community data set for application in fisheries and environment research

    Science.gov (United States)

    Berx, Barbara; Payne, Mark R.

    2017-04-01

    Scientific interest in the sub-polar gyre of the North Atlantic Ocean has increased in recent years. The sub-polar gyre has contracted and weakened, and changes in circulation pathways have been linked to changes in marine ecosystem productivity. To aid fisheries and environmental scientists, we present here a time series of the Sub-Polar Gyre Index (SPG-I) based on monthly mean maps of sea surface height. The established definition of the SPG-I is applied, and the first EOF (empirical orthogonal function) and PC (principal component) are presented. Sensitivity to the spatial domain and time series length are explored but found not to be important factors in terms of the SPG-I's interpretation. Our time series compares well with indices presented previously. The SPG-I time series is freely available online (http://dx.doi.org/10.7489/1806-1), and we invite the community to access, apply, and publish studies using this index time series.

  3. Patterns in micronekton diversity across the North Pacific Subtropical Gyre observed from the diet of longnose lancetfish (Alepisaurus ferox)

    Science.gov (United States)

    Portner, Elan J.; Polovina, Jeffrey J.; Choy, C. Anela

    2017-07-01

    We examined the diet of a common midwater predator, the longnose lancetfish (Alepisaurus ferox, n=1371), with respect to fork length, season, and capture location within the North Pacific Subtropical Gyre (NPSG). While A. ferox fed diversely across 97 prey families, approximately 70% of its diet by wet weight consisted of seven prey families (fishes: Sternoptychidae, Anoplogastridae, Omosudidae, Alepisauridae; hyperiid amphipods: Phrosinidae; octopods: Amphitretidae; polychaetes: Alciopidae). Altogether, these micronekton prey families constitute a poorly known forage community distinct from those exploited by other pelagic predators and poorly sampled by conventional methods. We demonstrate ontogenetic variation in diet between two size classes of A. ferox (consumed more fish and octopods, fewer crustaceans, and were more cannibalistic than small A. ferox. Ontogenetic shifts in vertical foraging habitat were observed as the consumption of larger and more mesopelagic prey with increasing fork length. Spatial and seasonal variation in the diet of A. ferox is consistent with expected patterns of variation in prey distribution with respect to oceanographic features of the NPSG. Within both size classes, the diets of specimens collected from the oligotrophic core of the NPSG were more diverse than those collected near the boundaries of the gyre and appeared to track seasonal variation in the position of the northern boundary of the gyre. Our data suggest seasonal and spatial variability in the composition of midwater forage communities exploited by A. ferox across the NPSG, and demonstrate that sustained monitoring of diet could provide valuable insights into long-term changes in these understudied communities.

  4. Ocean-Atmosphere CO2 Fluxes in the North Atlantic Subtropical Gyre: Association with Biochemical and Physical Factors during Spring

    Directory of Open Access Journals (Sweden)

    Macarena Burgos

    2015-08-01

    Full Text Available Sea surface partial pressure of CO2 (pCO2 was measured continuously in a transect of the North Atlantic subtropical gyre between Santo Domingo, Dominican Republic (18.1° N, 68.5° W and Vigo, Spain (41.9° N, 11.8° W during spring 2011. Additional biogeochemical and physical variables measured to identify factors controlling the surface pCO2 were analyzed in discrete samples collected at 16 sites along the transect at the surface and to a depth of 200 m. Sea surface pCO2 varied between 309 and 662 μatm, and showed differences between the western and eastern subtropical gyre. The subtropical gyre acted as a net CO2 sink, with a mean flux of −5.5 ± 2.2 mmol m−2 day−1. The eastern part of the transect, close to the North Atlantic Iberian upwelling off the Galician coast, was a CO2 source with an average flux of 33.5 ± 9.0 mmol m−2 day−1. Our results highlight the importance of making more surface pCO2 observations in the area located east of the Azores Islands since air-sea CO2 fluxes there are poorly studied.

  5. Effect of CO2 enrichment on phytoplankton photosynthesis in the North Atlantic sub-tropical gyre

    Science.gov (United States)

    Tilstone, Gavin; Šedivá, Barbora; Tarran, Glen; Kaňa, Radek; Prášil, Ondřej

    2017-11-01

    The effects of changes in CO2 concentration in seawater on phytoplankton community structure and photosynthesis were studied in the North Atlantic sub-tropical gyre. Three shipboard incubations were conducted for 48 h at ∼760 ppm CO2 and control (360 ppm CO2) from 49°N to 7°N during October and November 2010. Elevated CO2 caused a decrease in pH to ∼7.94 compared to ∼8.27 in the control. During one experiment, the biomass of nano- and picoeukaryotes increased under CO2 enrichment, but primary production decreased relative to the control. In two of the experiments the biomass was dominated by dinoflagellates, and there was a significant increase in the maximum photosynthetic rate (PmB) and light-limited slope of photosynthesis (αB) at CO2 concentrations of 760 ppm relative to the controls. 77 K emission spectroscopy showed that the higher photosynthetic rates measured under CO2 enrichment increased the connection of reversible photosystem antennae, which resulted in an increase in light harvesting efficiency and carbon fixation.

  6. The nuclear winter

    International Nuclear Information System (INIS)

    Velikhow, Y.P.

    1986-01-01

    Nuclear winter is an example of possible secondary effects, and if we speak of secondary we are thinking of small-scale second-order effects, but a nuclear winter is not a second-order effect. If you calculate the amount of heat produced by a nuclear explosion, it is a very small amount which does not have any chance of changing the Earth's climate, but a nuclear explosion drives or stars some new mechanism - the mechanism of nuclear winter - after 100 megatons of dust are transferred to the upper atmosphere. Another example of such amplification is radioactive fall-out, especially long-life radioactive fall-out after the possible elimination of the nuclear power industry, nuclear storage and distribution of storage waste around the globe. This is a very powerful amplification mechanism

  7. Ice‐flow structure and ice‐dynamic changes in the Weddell Sea sector of West Antarctica from radar-imaged internal layering

    OpenAIRE

    Bingham, Robert G.; Rippin, David M.; Karlsson, Nanna B.; Corr, Hugh F.J.; Jordan, Tom A.; Le Brocq, Anne M.; Rose, Kathryn C.; Ross, Neil; Siegert, Martin J.

    2015-01-01

    Recent studies have aroused concerns over the potential for ice draining the Weddell Sea sector of West Antarctica to figure more prominently in sea-level contributions should buttressing from the Filchner-Ronne Ice Shelf diminish. To improve understanding of how ice-stream dynamics there evolved through the Holocene, we interrogate Radio-Echo Sounding (RES) data from across the catchments of Institute and Möller Ice Streams (IIS and MIS), focusing especially on the use of internal layering t...

  8. Ice-flow structure and ice dynamic changes in the Weddell Sea sector of West Antarctica from radar-imaged internal layering

    OpenAIRE

    Bingham, Robert G.; Rippin, David; Karlsson, Nanna Bjørnholt; Corr, Hugh; Ferraccioli, F.; Jordan, Tom A.; Le Brocq, Anne M.; Kathryn, Rose C.; Ross, Neil; Siegert, Martin J.

    2015-01-01

    Recent studies have aroused concerns over the potential for ice draining the Weddell Sea sector of West Antarctica to figure more prominently in sea-level contributions should buttressing from the Filchner-Ronne Ice Shelf diminish. To improve understanding of how ice-stream dynamics there evolved through the Holocene, we interrogate Radio-Echo Sounding (RES) data from across the catchments of Institute and Möller Ice Streams (IIS and MIS), focusing especially on the use of internal layering t...

  9. New high-resolution record of Holocene climate change in the Weddell Sea from combined biomarker analysis of the Patriot Hills blue ice area

    Science.gov (United States)

    Fogwill, Christopher; Turney, Chris; Baker, Andy; Ellis, Bethany; Cooper, Alan; Etheridge, David; Rubino, Mauro; Thornton, David; Fernando, Francisco; Bird, Michale; Munksgaard, Niels

    2017-04-01

    We report preliminary analysis of biomarkers (including dissolved organic matter (DOM) and DNA) from the Patriot Hills blue ice area (BIA), from the Ellsworth Mountains in the Weddell Sea Embayment. Preliminary isotopic and multiple gas analysis (CO2, CH4, N2O and CO) demonstrate that the Holocene comprises more than 50% of the 800m long BIA record, and in combination isotopic and biomarker analysis reveals a remarkable record of centennial variability through the Holocene in this sector of the Weddell Sea. Analysis using a Horiba Aqualog - which measures the fluorescence of DOM by producing a map of the fluorescence through an excitation-emission matrix (EEM) - identifies the presence of two marine protein-like components in both modern snow pit samples and within the Holocene part of Patriot Hills BIA transect. Intriguingly, the modern seasonal trends in DOM, recorded in contemporary snow pits, have relatively low signals compared to those recorded in the mid-Holocene record, suggesting a reduction in DOM signal in contemporary times. Given that the δD excess data suggests the source of precipitation has remained constant through the Holocene, the biomarker signal must relate to multi-year marine productivity signals from the Weddell Sea. The marked variability in DOM between the mid-Holocene and contemporary times can only relate to periods of sustained, enhanced biological productivity in the Weddell Sea associated with shifts in Southern Annular Mode, sea ice variability, changes in ventilation or polynya activity. Here we discuss the possible drivers of these changes and describe how this approach at this BIA could benefit conventional ice core records regionally.

  10. Density of pack-ice seals and penguins in the western Weddell Sea in relation to ice thickness and ocean depth

    Science.gov (United States)

    Flores, Hauke; Haas, Christian; van Franeker, Jan Andries; Meesters, Erik

    2008-04-01

    Aerial band transect censuses were carried out parallel with ice thickness profiling surveys in the pack ice of the western Weddell Sea during the ISPOL (Ice Station POLarstern) expedition of R.V. Polarstern from November 2004 to January 2005. Three regions were surveyed: the deep sea of the Weddell Sea, a western continental shelf/slope region where R.V. Polarstern passively drifted with an ice floe (ISPOL), and a northern region (N). Animal densities were compared among regions and in relation to bathymetry and ice thickness distribution. Crabeater seals Lobodon carcinophaga were the most abundant species in all three regions. Their density was significantly lower in the deep sea (0.50 km -2) than in the ISPOL (1.00 km -2) and northern regions (1.21 km -2). Weddell seals Leptonychotes weddellii were not sighted in the deep-sea region, their density elsewhere ranging from 0.03 (N) to 0.08 km -2 (ISPOL). Leopard seals Hydrurga leptonyx were observed in all three areas, but could only be quantified in the deep-sea (0.05 km -2) and northern regions (0.06 km -2). The abundance of emperor penguins Aptenodytes forsteri was markedly higher in the northern (0.75 km -2) than in the ISPOL (0.13 km -2) and the deep-sea region (not quantified). Crabeater seal density was significantly related to ocean depth and modal ice thickness.

  11. Decadal Salinity Changes in the Oceanic Subtropical Gyres and Connection to Changes in the Global Water Cycle

    Science.gov (United States)

    Melzer, Bryce Andrew

    There is evidence that the global water cycle has been undergoing an intensification over several decades as a response to increasing atmospheric temperatures, particularly in regions with skewed evaporation - precipitation (E-P) patterns such as the oceanic subtropical gyres. However, observational data (rain gauges, etc.) can be quite sparse over such areas due to the inaccessibility of open ocean regions. This study utilizes in situ data, reanalysis, and model outputs to infer interannual to decadal scale trends in surface freshwater forcing within remote, evaporation-dominated subtropical regions of the ocean as they pertain to the past and present state of the global water cycle. Emphasized in this study is the importance of utilizing a wide range of ocean parameters to strengthen and validate the inferences made from any one proxy of a given parameter. A positive trend in sea surface salinity in the subtropical gyres revealed evidence for decadal intensification in the surface forcing of these regions. Zonal drift in the location of the salinity maximum of the south Pacific, north Atlantic, and south Indian regions implies a change in the mean near-surface currents responsible for advecting high salinity waters into the region. Additionally, a comparison of satellite, in situ, and model salinity datasets was conducted to highlight the potential applications of Aquarius and SMOS satellite-derived salinity products over oceanic regions of low observational density. Spatial and temporal salinity trends in the five subtropical gyre regions were also analyzed over the past six decades, with a focus on the subsurface salinity of the upper 1000 m of the ocean. Our results indicate an overall salinity increase within the mixed layer, and a salinity decrease at depths greater than 200m in the global subtropical gyres over 61 years. Our analysis of decadal variability of depth-integrated mixed layer fluxes into and out of the gyres reveals little change in the strength

  12. Titan's Emergence from Winter

    Science.gov (United States)

    Flasar, F. Michael; Achterberg, Richard; Jennings, Donald; Schinder, Paul

    2011-01-01

    We summarize the changes in Titans thermal structure derived from Cassini CIRS and radio-occultation data during the transition from winter to early spring. Titan's surface, and middle atmosphere show noticeable seasonal change, whereas that in most of the troposphere is mated. This can be understood in terms of the relatively small radiative relaxation time in the middle atmosphere and much larger time scale in the troposphere. The surface exhibits seasonal change because the heat capacity in an annual skin depth is much smaller than that in the lowest scale height of the troposphere. Surface temperatures rise 1 K at raid and high latitudes in the winter northern hemisphere and cool in the southern hemisphere. Changes in in the middle atmosphere are more complicated. Temperatures in the middle stratosphere (approximately 1 mbar) increase by a few kelvin at mid northern latitudes, but those at high latitudes first increase as that region moves out of winter shadow, and then decrease. This probably results from the combined effect of increased solar heating as the suit moves higher in the sky and the decreased adiabatic warming as the sinking motions associated with the cross-equatorial meridional cell weaken. Consistent with this interpretation, the warm temperatures observed higher up at the winter polar stratopause cool significantly.

  13. Holocene lowering of the Laurentide ice sheet affects North Atlantic gyre circulation and climate

    Science.gov (United States)

    Ivanovic, R. F.; Gregoire, L. J.; Maycock, A.; Valdes, P. J.

    2017-12-01

    The Laurentide ice sheet, which covered Canada during glacial periods, had a major influence on atmospheric circulation and surface climate, but its role in climate during the early Holocene (9-7 ka), when it was thinner and confined around Hudson Bay, is unclear. It has been suggested that the demise of the ice sheet played a role in the 8.2 ka event (an abrupt 1-3 °C Northern Hemisphere cooling lasting 160 years) through the influence of changing topography on atmospheric circulation. To test this hypothesis, and to investigate the broader implications of changing ice sheet topography for climate, we analyse a set of equilibrium climate simulations with ice sheet topographies taken at 500 year intervals from 9.5 ka to 8.0 ka. Between 9.5 and 8.0 ka, our simulations show a 2 °C cooling south of Iceland and a 1 °C warming between 40-50° N in the North Atlantic. These surface temperature changes are associated with a weakening of the subtropical and subpolar gyres caused by a decreasing wind stress curl over the mid-North Atlantic as the ice sheet lowers. The climate response is strongest during the period of peak ice volume change (9.5 ka - 8.5 ka), but becomes negligible after 8.5 ka. The climatic effects of the Laurentide ice sheet lowering are restricted to the North Atlantic sector. Thus, topographic forcing did not play a significant role in the 8.2 ka event and had only a small effect on Holocene climate change compared to the effects of changes in greenhouse gases, insolation and ice sheet meltwater.

  14. Holocene lowering of the Laurentide ice sheet affects North Atlantic gyre circulation and climate

    Science.gov (United States)

    Gregoire, Lauren J.; Ivanovic, Ruza F.; Maycock, Amanda C.; Valdes, Paul J.; Stevenson, Samantha

    2018-02-01

    The Laurentide ice sheet, which covered Canada during glacial periods, had a major influence on atmospheric circulation and surface climate, but its role in climate during the early Holocene (9-7 ka), when it was thinner and confined around Hudson Bay, is unclear. It has been suggested that the demise of the ice sheet played a role in the 8.2 ka event (an abrupt 1-3 °C Northern Hemisphere cooling lasting 160 years) through the influence of changing topography on atmospheric circulation. To test this hypothesis, and to investigate the broader implications of changing ice sheet topography for climate, we analyse a set of equilibrium climate simulations with ice sheet topographies taken at 500 year intervals from 9.5 to 8.0 ka. Between 9.5 and 8.0 ka, our simulations show a 2 °C cooling south of Iceland and a 1 °C warming between 40° and 50°N in the North Atlantic. These surface temperature changes are associated with a weakening of the subtropical and subpolar gyres caused by a decreasing wind stress curl over the mid-North Atlantic as the ice sheet lowers. The climate response is strongest during the period of peak ice volume change (9.5-8.5 ka), but becomes negligible after 8.5 ka. The climatic effects of the Laurentide ice sheet lowering during the Holocene are restricted to the North Atlantic sector. Thus, topographic forcing is unlikely to have played a major role in the 8.2 ka event and had only a small effect on Holocene climate change compared to the effects of changes in greenhouse gases, insolation and ice sheet meltwater.

  15. An abrupt weakening of the subpolar gyre as trigger of Little Ice Age-type episodes

    Science.gov (United States)

    Moreno-Chamarro, Eduardo; Zanchettin, Davide; Lohmann, Katja; Jungclaus, Johann H.

    2017-02-01

    We investigate the mechanism of a decadal-scale weakening shift in the strength of the subpolar gyre (SPG) that is found in one among three last millennium simulations with a state-of-the-art Earth system model. The SPG shift triggers multicentennial anomalies in the North Atlantic climate driven by long-lasting internal feedbacks relating anomalous oceanic and atmospheric circulation, sea ice extent, and upper-ocean salinity in the Labrador Sea. Yet changes throughout or after the shift are not associated with a persistent weakening of the Atlantic Meridional Overturning Circulation or shifts in the North Atlantic Oscillation. The anomalous climate state of the North Atlantic simulated after the shift agrees well with climate reconstructions from within the area, which describe a transition between a stronger and weaker SPG during the relatively warm medieval climate and the cold Little Ice Age respectively. However, model and data differ in the timing of the onset. The simulated SPG shift is caused by a rapid increase in the freshwater export from the Arctic and associated freshening in the upper Labrador Sea. Such freshwater anomaly relates to prominent thickening of the Arctic sea ice, following the cluster of relatively small-magnitude volcanic eruptions by 1600 CE. Sensitivity experiments without volcanic forcing can nonetheless produce similar abrupt events; a necessary causal link between the volcanic cluster and the SPG shift can therefore be excluded. Instead, preconditioning by internal variability explains discrepancies in the timing between the simulated SPG shift and the reconstructed estimates for the Little Ice Age onset.

  16. Dust, volcanic ash, and the evolution of the South Pacific Gyre through the Cenozoic

    Science.gov (United States)

    Dunlea, Ann G.; Murray, Richard W.; Sauvage, Justine; Spivack, Arthur J.; Harris, Robert N.; D'Hondt, Steven

    2015-08-01

    We examine the 0-100 Ma paleoceanographic record retained in pelagic clay from the South Pacific Gyre (SPG) by analyzing 47 major, trace, and rare earth elements in bulk sediment in 206 samples from seven sites drilled during Integrated Ocean Drilling Program Expedition 329. We use multivariate statistical analyses (Q-mode factor analysis and multiple linear regression) of the geochemical data to construct a model of bulk pelagic clay composition and mass accumulation rates (MAR) of six end-members, (post-Archean average Australian shale, rhyolite, basalt, Fe-Mn-oxyhydroxides, apatite, and excess Si). Integrating the results with Co-based age models at Sites U1365, U1366, U1369, and U1370, we link changes in MAR of these components to global oceanographic, terrestrial, and climatic transformations through the Cenozoic. Our results track the spatial extent (thousands of kilometers) of dust deposition in the SPG during the aridification of Australia. Dispersed ash is a significant component of the pelagic clay, often comprising >50% by mass, and records episodes of Southern Hemisphere volcanism. Because both are transported by wind, the correlation of dust and ash MAR depends on the site's latitude and suggests meridional shifts in the position of atmospheric circulation cells. The hydrothermal MARs provide evidence for rapid deposition from the Osbourn Trough spreading ridge before it went extinct. Excess Si MARs show that the abrupt increase in siliceous productivity observed at Site U1371 also extended at least as far north as Sites U1369 and U1370, suggesting large-scale reorganizations of oceanic Si distributions 10-8 Ma in the southern SPG.

  17. Seabed images from Southern Ocean shelf regions off the northern Antarctic Peninsula and in the southeastern Weddell Sea

    Science.gov (United States)

    Piepenburg, Dieter; Buschmann, Alexander; Driemel, Amelie; Grobe, Hannes; Gutt, Julian; Schumacher, Stefanie; Segelken-Voigt, Alexandra; Sieger, Rainer

    2017-07-01

    Recent advances in underwater imaging technology allow for the gathering of invaluable scientific information on seafloor ecosystems, such as direct in situ views of seabed habitats and quantitative data on the composition, diversity, abundance, and distribution of epibenthic fauna. The imaging approach has been extensively used within the research project DynAMo (Dynamics of Antarctic Marine Shelf Ecosystems) at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research Bremerhaven (AWI), which aimed to comparatively assess the pace and quality of the dynamics of Southern Ocean benthos. Within this framework, epibenthic spatial distribution patterns have been comparatively investigated in two regions in the Atlantic sector of the Southern Ocean: the shelf areas off the northern tip of the Antarctic Peninsula, representing a region with above-average warming of surface waters and sea-ice reduction, and the shelves of the eastern Weddell Sea as an example of a stable high-Antarctic marine environment that is not (yet) affected by climate change. The AWI Ocean Floor Observation System (OFOS) was used to collect seabed imagery during two cruises of the German research vessel Polarstern, ANT-XXIX/3 (PS81) to the Antarctic Peninsula from January to March 2013 and ANT-XXXI/2 (PS96) to the Weddell Sea from December 2015 to February 2016. Here, we report on the image and data collections gathered during these cruises. During PS81, OFOS was successfully deployed at a total of 31 stations at water depths between 29 and 784 m. At most stations, series of 500 to 530 pictures ( > 15 000 in total, each depicting a seabed area of approximately 3.45 m2 or 2.3 × 1.5 m) were taken along transects approximately 3.7 km in length. During PS96, OFOS was used at a total of 13 stations at water depths between 200 and 754 m, yielding series of 110 to 293 photos (2670 in total) along transects 0.9 to 2.6 km in length. All seabed images taken during the two cruises

  18. Editorial - The winter Atomiades

    CERN Multimedia

    Staff Association

    2011-01-01

    As we wrote in our previous editorial, the Staff Association gives direct support to sports events, such as the Atomiades, a section of the Association of Sports Communities of European Research Institutes, which brings together sportsmen and women from 38 European research centres in 13 countries (Austria, Belgium, Czech Republic, United Kingdom, Finland, France, Germany, Hungary, Italy, Luxemburg, the Netherlands, Russia, and Switzerland). The summer Atomiades take place between the months of June and September every three years. Thirteen such events have taken place since 1973, the last one in June 2009 in Berlin. As far as the winter Atomiades are concerned, also organized every three years, and alternating with the summer Atomiades, there have been eleven since 1981, the last one at the end of January this year in neighbouring France. The following article tells the wonderful adventure of the CERN staff who took part in this event. A positive outcome for CERN skiers at the winter Atomiades The 11t...

  19. Winter is losing its cool

    Science.gov (United States)

    Feng, S.

    2017-12-01

    Winter seasons have significant societal impacts across all sectors ranging from direct human health to ecosystems, transportation, and recreation. This study quantifies the severity of winter and its spatial-temporal variations using a newly developed winter severity index and daily temperature, snowfall and snow depth. The winter severity and the number of extreme winter days are decreasing across the global terrestrial areas during 1901-2015 except the southeast United States and isolated regions in the Southern Hemisphere. These changes are dominated by winter warming, while the changes in daily snowfall and snow depth played a secondary role. The simulations of multiple CMIP5 climate models can well capture the spatial and temporal variations of the observed changes in winter severity and extremes during 1951-2005. The models are consistent in projecting a future milder winter under various scenarios. The winter severity is projected to decrease 60-80% in the middle-latitude Northern Hemisphere under the business-as-usual scenario. The winter arrives later, ends earlier and the length of winter season will be notably shorter. The changes in harsh winter in the polar regions are weak, mainly because the warming leads to more snowfall in the high latitudes.

  20. Energetics of breath-hold hunting: modeling the effects of aging on foraging success in the Weddell seal.

    Science.gov (United States)

    Hindle, Allyson G; Horning, Markus

    2010-06-07

    A simulation model was developed to predict age-related changes in foraging energetics of individual Weddell seals, Leptonychotes weddellii. Aging in diving animals is interesting because their characteristic cyclic sequence of apneustic hunting and eupnea should elevate oxidative stress, possibly accelerating aging. Such a hypothesis can be evaluated by modeling energetics of constrained, time-partitioned activities with well-defined costs. Three possible consequences of physiological aging in divers were specified and appraised. The model examined the potential impacts of age-related decline in muscle contractile ability, increased buoyancy, and reduced aerobic dive limit, alone and in combination, on a daily energy budget. A uniform age effect evident in model outputs is reduced foraging efficiency. The components of this net effect are exacerbated for sub-optimal behavioral-response settings or environmental conditions. The model predicts that with advancing age, efficiency declines increase for aging scenarios in the following order: simulated 'young' adults; 'old' seals with increased buoyancy; 'old' seals with reduced aerobic dive limit; 'old' seals having reduced muscle contractile efficiency; and, 'old' seals with all three conditions. The model indicates narrowed behavioral options to maintain positive energy balance in older animals, suggesting that behavioral plasticity may not allow older animals to compensate for age-related performance constraints. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  1. Low post-glacial rebound rates in the Weddell Sea due to Late Holocene ice-sheet readvance

    Science.gov (United States)

    Bradley, Sarah L.; Hindmarsh, Richard C. A.; Whitehouse, Pippa L.; Bentley, Michael J.; King, Matt A.

    2015-03-01

    Many ice-sheet reconstructions assume monotonic Holocene retreat for the West Antarctic Ice Sheet, but an increasing number of glaciological observations infer that some portions of the ice sheet may be readvancing, following retreat behind the present-day margin. A readvance in the Weddell Sea region can reconcile two outstanding problems: (i) the present-day widespread occurrence of seemingly stable ice streams grounded on beds that deepen inland; and (ii) the inability of models of glacial isostatic adjustment to match present-day uplift rates. By combining a suite of ice loading histories that include a readvance with a model of glacial isostatic adjustment we report substantial improvements to predictions of present-day uplift rates, including reconciling one problematic observation of land sinking. We suggest retreat behind present grounding lines occurred when the bed was lower, and isostatic recovery has since led to shallowing, ice sheet re-grounding and readvance. The paradoxical existence of grounding lines in apparently unstable configurations on reverse bed slopes may be resolved by invoking the process of unstable advance, in accordance with our load modelling.

  2. Biogeochemistry of a low-activity cold seep in the Larsen B area, western Weddell Sea, Antarctica

    Directory of Open Access Journals (Sweden)

    J. Gutt

    2009-11-01

    Full Text Available First videographic indication of an Antarctic cold seep ecosystem was recently obtained from the collapsed Larsen B ice shelf, western Weddell Sea (Domack et al., 2005. Within the framework of the R/V Polarstern expedition ANTXXIII-8, we revisited this area for geochemical, microbiological and further videographical examinations. During two dives with ROV Cherokee (MARUM, Bremen, several bivalve shell agglomerations of the seep-associated, chemosynthetic clam Calyptogena sp. were found in the trough of the Crane and Evans glacier. The absence of living clam specimens indicates that the flux of sulphide and hence the seepage activity is diminished at present. This impression was further substantiated by our geochemical observations. Concentrations of thermogenic methane were moderately elevated with 2 μM in surface sediments of a clam patch, increasing up to 9 μM at a sediment depth of about 1 m in the bottom sections of the sediment cores. This correlated with a moderate decrease in sulphate from about 28 mM at the surface down to 23.4 mM, an increase in sulphide to up to 1.43 mM and elevated rates of the anaerobic oxidation of methane (AOM of up to 600 pmol cm−3 d−1 at about 1 m below the seafloor. Molecular analyses indicate that methanotrophic archaea related to ANME-3 are the most likely candidates mediating AOM in sediments of the Larsen B seep.

  3. Long-term observations of theWeddell Sea Anomaly based on the Swarm, CHAMP and DEMETER missions

    Science.gov (United States)

    Slominska, E.

    2016-12-01

    Normalized density difference index (INDD) was introduced for the purpose of detection of such phenomena as the Weddell Sea Anomaly (WSA). With this basic approach, we are capable of identifying spatial and temporal occurrence of anomalies exhibiting reversed diurnal cycle, characterized by greater ionospheric plasma densities observed in the post-sunset hours, when compared to day-time ones. Development of the WSA together with similar phenomenon observed in the Northern Hemisphere, named as the Mid-latitude Summer Nighttime Anomaly is documented with three satellite missions Swarm, DEMETER, and CHAMP. Since the generation of discussed anomalies is still an open issue, multi-mission and multi-instrumental observations at various altitudes should improve our understanding of the phenomena, and verify the role of several potential mechanisms used for explanation. Among mentioned mechanisms, combined result of thermospheric wind, solar photo-ionization, and the local magnetic field configuration is taken as a most comprehensive explanation. Analysis based on long-term trends of observations from three missions and six satellites are aimed at the proper parametrization of the phenomenon. Using spatial gradients in the magnetic field components derived from Swarm A/B/C magnetometers, we discuss longitudinal distributions and variations of anomalies. The study quantifies hemispheric differences between two anomalies, as well as temporal trends concerning the solar cycle.

  4. Diversity and Activity of Communities Inhabiting Plastic Debris in the North Pacific Gyre

    Science.gov (United States)

    Bryant, Jessica A.; Clemente, Tara M.; Viviani, Donn A.; Fong, Allison A.; Thomas, Kimberley A.; Kemp, Paul; Karl, David M.; White, Angelicque E.

    2016-01-01

    oceanic macrobiota, including mammals and birds, are well documented, little is known about its influence on smaller marine residents, including microbes that have key roles in ocean biogeochemistry. Our work provides a new perspective on microbial communities inhabiting microplastics that includes its effect on microbial biogeochemical activities and a description of the cross-domain communities inhabiting plastic particles. This study is among the first molecular ecology, plastic debris biota surveys in the North Pacific Subtropical Gyre. It has identified fundamental differences in the functional potential and taxonomic composition of plastic-associated microbes versus planktonic microbes found in the surrounding open-ocean habitat. Author Video: An author video summary of this article is available. PMID:27822538

  5. Diversity and Activity of Communities Inhabiting Plastic Debris in the North Pacific Gyre.

    Science.gov (United States)

    Bryant, Jessica A; Clemente, Tara M; Viviani, Donn A; Fong, Allison A; Thomas, Kimberley A; Kemp, Paul; Karl, David M; White, Angelicque E; DeLong, Edward F

    2016-01-01

    , including mammals and birds, are well documented, little is known about its influence on smaller marine residents, including microbes that have key roles in ocean biogeochemistry. Our work provides a new perspective on microbial communities inhabiting microplastics that includes its effect on microbial biogeochemical activities and a description of the cross-domain communities inhabiting plastic particles. This study is among the first molecular ecology, plastic debris biota surveys in the North Pacific Subtropical Gyre. It has identified fundamental differences in the functional potential and taxonomic composition of plastic-associated microbes versus planktonic microbes found in the surrounding open-ocean habitat. Author Video : An author video summary of this article is available.

  6. Autonomous Sampling of Remote Phytoplankton Blooms in the North Pacific Subtropical Gyre (July-Aug. 2015).

    Science.gov (United States)

    Anderson, E. E.; Wilson, C.; Villareal, T. A.

    2016-12-01

    Satellite ocean color data regularly reveals the existence of large (103 km2) phytoplankton blooms in the North Pacific Ocean that can persist for weeks to months and are often associated with N2 fixing diatom symbioses. The basin size and inability to accurately forecast these blooms makes sampling these events difficult outside of the time series at Station ALOHA. We used an autonomous Wave Glider surface vehicle (Honey Badger) to conduct a large regional survey well north of HI to examine bloom composition and key species distribution. Honey Badger was equipped with a gpCTD, downward looking camera, 2 C3 fluorometers, wind and wave sensors, a Turner Designs' Phytoflash, and a Sequoia Scientific LISST-Holo for imaging cells. Most of the data collected was available in near-real time through NOAA's ERDDAP data server. The 159 day mission began 1 June 2015 and covered 6800 km. From 1 July 2015 to 31 August 2015, Honey Badger transited from low levels of chlorophyll-a (chl) (0.06±0.01 mg m-3), through a mesoscale­ bloom, and then into a broad regional chl increase (0.08±0.01 mg m-3) as noted by the AQUA MODIS satellite. Phytoplankton cell counts (> 14,000 Hemiaulus cells L-1) and increased nocturnal Fv:Fm yields (maximum > 0.61) were concurrent with the 0.1 µg Chl L-1 bloom. A separate bloom of the Rhizosolenia-Richelia symbiosis was noted (> 3,000 Rhizosolenia-Richelia cells L-1) within a smaller, short-lived bloom with a biovolume 2.1 times higher than the rest of the southern transect. The broad regional chl increase in the southern leg of the transit was concurrent with a sustained Hemiaulus increase to 102 cells L-1. Diel patterns in Fv:Fm did not suggest Fe limitation anywhere in the transect. Elevated yields were found only in the diatom increases. Honey Badger and the instruments it carried were useful tools for the investigation of remote bloom dynamics in the Eastern North Pacific Subtropical Gyre.

  7. Contrasting distributions of dissolved gaseous mercury concentration and evasion in the North Pacific Subarctic Gyre and the Subarctic Front

    Science.gov (United States)

    Kim, Hyunji; Rhee, Tae Siek; Hahm, Doshik; Hwang, Chung Yeon; Yang, Jisook; Han, Seunghee

    2016-04-01

    The distribution of dissolved gaseous mercury (DGM) and the oxidation-reduction processes of mercury (Hg) in the surface and subsurface ocean are currently understudied despite their importance in ocean-atmosphere interactions. We investigated the Hg(0) evasion and the DGM distribution at water depths of 2-500 m in the Subarctic Front, Western Subarctic Gyre, and Bering Sea of the Northwestern Pacific. The mean DGM concentration in the surface mixed water (evasion flux were significantly higher in the Subarctic Front (125±5.0 fM and 15 pmol m-2 h-1, respectively), which typically has lower nutrient levels and higher primary production, than in the Western Subarctic Gyre and the Bering Sea (74±18 fM and 3.2±1.2 pmol m-2 h-1, respectively). The variation in the chlorophyll-a concentration and extracellular protease activity predicted 54% and 48% of the DGM variation, respectively, in the euphotic zone (2-50 m). The DGM concentration in aphotic intermediate water (415±286 fM) was positively correlated to the apparent oxygen utilization (AOU; r2=0.94 and pevasion is closely linked to primary production in euphotic water and organic remineralization in aphotic intermediate water. The oceanic alterations in these factors may induce significant modification in Hg redox speciation in the Northwestern Pacific.

  8. Sea ice circulation around the Beaufort Gyre: The changing role of wind forcing and the sea ice state

    Science.gov (United States)

    Petty, Alek A.; Hutchings, Jennifer K.; Richter-Menge, Jacqueline A.; Tschudi, Mark A.

    2016-05-01

    Sea ice drift estimates from feature tracking of satellite passive microwave data are used to investigate seasonal trends and variability in the ice circulation around the Beaufort Gyre, over the multidecadal period 1980-2013. Our results suggest an amplified response of the Beaufort Gyre ice circulation to wind forcing, especially during the late 2000s. We find increasing anticyclonic ice drift across all seasons, with the strongest trend in autumn, associated with increased ice export out of the southern Beaufort Sea (into the Chukchi Sea). A flux gate analysis highlights consistency across a suite of drift products. Despite these seasonal anticyclonic ice drift trends, a significant anticyclonic wind trend occurs in summer only, driven, in-part, by anomalously anticyclonic winds in 2007. Across all seasons, the ice drift curl is more anticyclonic than predicted from a linear relationship to the wind curl in the 2000s, compared to the 1980s/1990s. The strength of this anticyclonic ice drift curl amplification is strongest in autumn and appears to have increased since the 1980s (up to 2010). In spring and summer, the ice drift curl amplification occurs mainly between 2007 and 2010. These results suggest nonlinear ice interaction feedbacks (e.g., a weaker, more mobile sea ice pack), enhanced atmospheric drag, and/or an increased role of the ocean. The results also show a weakening of the anticyclonic wind and ice circulation since 2010.

  9. Slow acidification of the winter mixed layer in the subarctic western North Pacific

    Science.gov (United States)

    Wakita, Masahide; Nagano, Akira; Fujiki, Tetsuichi; Watanabe, Shuichi

    2017-08-01

    We used carbon dioxide (CO2) system data collected during 1999-2015 to investigate ocean acidification at time series sites in the western subarctic region of the North Pacific Ocean. The annual mean pH at station K2 decreased at a rate of 0.0025 ± 0.0010 year-1 mostly in response to oceanic uptake of anthropogenic CO2. The Revelle factor increased rapidly (0.046 ± 0.022 year-1), an indication that the buffering capacity of this region of the ocean has declined faster than at other time series sites. In the western subarctic region, the pH during the winter decline at a slower rate of 0.0008 ± 0.0004 year-1. This was attributed to a reduced rate of increase of dissolved inorganic carbon (DIC) and an increase of total alkalinity (TA). The reduction of DIC increase was caused by the decline of surface water density associated with the pycnocline depression and the reduction of vertical diffusion flux from the upper pycnocline. These physical changes were probably caused by northward shrinkage of the western subarctic gyre and global warming. Meanwhile, the contribution of the density decline to the TA increase is canceled out by that of the reduced vertical diffusive flux. We speculated that the winter TA increase is caused mainly by the accumulation of TA due to the weakened calcification by organisms during the winter.

  10. Decontamination and winter conditions

    International Nuclear Information System (INIS)

    Quenild, C.; Tveten, U.

    1984-12-01

    The report deals with two decontamonation experiments under winter conditions. A snow-covered parking lot was contaminated, and the snow was subsequently removed using standard snow-moving equipment. The snow left behind was collected and the content of contaminant was determined. A non-radioactive contaminant was used. A decontamination factor exceeding 100 was obtained. Although the eksperimental conditions were close to ideal, it is reason to believe that extremely efficient removal of deposited materials on a snow surface is achivable. In another investigation, run-off from agricultural surface, contaminated while covered with snow, was measured A lycimeter was used in this experiment. A stable layer of ice and snow was allowed to form before contamination. The run-off water was collected at each thaw period until all snow and ice was gone. Cs-134 was used as contaminant. Roughly 30% of the Cs-134 with which the area was contaminated ran off with the melt water. Following a reactor accident situation, this would have given a corresponding reduction in the long term doses. Both of these experiments show that consequence calculation assumptions, as they are currently applied to large accident assessment, tend to overestimate the consequences resulting from accidents taking place under winter conditions

  11. Winter School Les Houches

    CERN Document Server

    Lannoo, Michel; Bastard, Gérald; Voos, Michel; Boccara, Nino

    1986-01-01

    The Winter School held in Les Houches on March 12-21, 1985 was devoted to Semiconductor Heterojunctions and Superlattices, a topic which is recognized as being now one of the most interesting and active fields in semiconductor physics. In fact, following the pioneering work of Esaki and Tsu in 1970, the study of these two-dimensional semiconductor heterostructures has developed rapidly, both from the point of view of basic physics and of applications. For instance, modulation-doped heterojunctions are nowadays currently used to investigate the quantum Hall effect and to make very fast transistors. This book contains the lectures presented at this Winter School, showing in particular that many aspects of semiconductor heterojunctions and super­ lattices were treated, extending from the fabrication of these two-dimensional systems to their basic properties and applications in micro-and opto-electron­ ics. Among the subjects which were covered, one can quote as examples: molecular beam epitaxy and metallorgani...

  12. Measurements for winter road maintenance

    OpenAIRE

    Riehm, Mats

    2012-01-01

    Winter road maintenance activities are crucial for maintaining the accessibility and traffic safety of the road network at northerly latitudes during winter. Common winter road maintenance activities include snow ploughing and the use of anti-icing agents (e.g. road salt, NaCl). Since the local weather is decisive in creating an increased risk of slippery conditions, understanding the link between local weather and conditions at the road surface is critically important. Sensors are commonly i...

  13. Winter fuels report

    Energy Technology Data Exchange (ETDEWEB)

    1990-11-29

    The Winter Fuels Report is intended to provide concise, timely information to the industry, the press, policymakers, consumers, analysts, and state and local governments on the following topics: distillate fuel oil net production, imports and stocks for all PADD's and product supplied on a US level; propane net product supplied on a US level; propane net production, imports and stocks for Petroleum Administration for Defense Districts (PADD) I, II, and III; natural gas supply and disposition and underground storage for the United States and consumption for all PADD's; residential and wholesale pricing data for propane and heating oil for those states participating in the joint Energy Information Administration (EIA)/State Heating Oil and Propane Program; crude oil and petroleum price comparisons for the United States and selected cities; and US total heating degree-days by city. 27 figs, 12 tabs.

  14. Winter fuels report

    Energy Technology Data Exchange (ETDEWEB)

    1995-02-17

    The Winter Fuels Report is intended to provide consise, timely information to the industry, the press, policymakers, consumers, analysts, and State and local governments on the following topics: Distillate fuel oil net production, imports and stocks on a US level and for all Petroleum Administration for Defense Districts (PADD) and product supplied on a US level; Natural gas supply and disposition and underground storage for the US and consumption for all PADD`s as well as selected National average prices; Residential and wholesale pricing data for heating oil and propane for those States participating in the joint Energy Information Administration (EIA)/State Heating Oil and Propane Program; Crude oil and petroleum price comparisons for the US and selected cities; and A 6-10 Day and 30-Day outlook for temperature and precipitation and US total heating degree days by city.

  15. Winter fuels report

    International Nuclear Information System (INIS)

    1995-01-01

    The Winter Fuels Report is intended to provide concise, timely information to the industry, the press, policymakers, consumers, analysts, and State and local governments on the following topics: distillate fuel oil net production, imports and stocks on a US level and for all Petroleum Administration for Defense Districts (PADD) and product supplied on a US level; propane net production, imports and stocks on a US level and for PADD's I, II, and III; natural gas supply and disposition and underground storage for the US and consumption for all PADD's, as well as selected National average prices; residential and wholesale pricing data for heating oil and propane for those States participating in the joint Energy Information Administration (EIA)/State Heating Oil and Propane Program; crude oil and petroleum price comparisons for the US and selected cities; and a 6-10 day, 30-Day, and 90-Day outlook for temperature and precipitation and US total heating degree-days by city

  16. Stamena winter wheat variety

    Directory of Open Access Journals (Sweden)

    Mišić Todor

    2001-01-01

    Full Text Available Stamena is a winter wheat variety developed at the Institute of Field and Vegetable Crops in Novi Sad, Yugoslavia. It was released by the Federal Commission for varietals Approval in 1999. Stamena was developed by crossing genetically divergent and highly productive parents Lasta and Rodna (Breeders: T. Mišić. N. Mladenov, Z. Jerković and R. Jevtić. Spike is white, smooth, awn less, medium compact with 18-21 spike lets. The grain is vitreous and dark red (Triticum aestivum L. ssp. vulgar e var. lutescens. Stamena is a medium early variety, 1 day earlier than Partizanka and 3 days earlier than Jugoslavija (Table 4. It has excellent resistance to winterkilling, as in very winter hardy Partizanka. The average stem height is 78 cm, with a good resistance to lodging. Stamena has field resistance to leaf rust (Pucce, recondita tritict, horizontal resistance, which is the type of resistance that modern wheat breeding is interested in. The resistance to stem rust (Pucce, graminis tritict is good and to powdery mildew (Erysiphegraminis tritici very good. The 1000 grain mass is about 32 g and volume grain mass 81.3 kg/hi. (Table 2. Stamena is classified in the subgroup A-l. It has excellent milling and baking quality and it belong to the 1st technological group (quality enhancer. The quantity of dry gluten is about 9%. The variety Stamena is a very productive, with the genetic potential for grain above 11 t/ha suitable for growing on fertile and less fertile soils. It has started to be grown commercially in 2000.

  17. Optimal Cross Hedging Winter Canola

    OpenAIRE

    Kim, Seon-Woong; Brorsen, B. Wade; Yoon, Byung-Sam

    2014-01-01

    Winter canola in the southern Great Plains has shown large price fluctuations and there have been questions about which futures market could be used to reduce price risk. Our results indicate that the optimal futures contract to cross hedge winter canola is soybean oil futures.

  18. Gross community production and metabolic balance in the South Pacific Gyre, using a non intrusive bio-optical method

    Directory of Open Access Journals (Sweden)

    H. Claustre

    2008-03-01

    Full Text Available The very clear waters of the South Pacific Gyre likely constitute an end-member of oligotrophic conditions which remain essentially unknown with respect to its impact on carbon fixation and exportation. We describe a non-intrusive bio-optical method to quantify the various terms of a production budget (Gross community production, community losses, net community production in this area. This method is based on the analysis of the diel cycle in Particulate Organic Carbon (POC, derived from high frequency measurements of the particle attenuation coefficient cp. We report very high integrated rates of Gross Community Production within the euphotic layer (average of 846±484 mg C m−2 d−1 for 17 stations that are far above any rates determined using incubation techniques for such areas. Furthermore we show that the daily production of POC is essentially balanced by the losses so that the system cannot be considered as net heterotrophic. Our results thus agree well with geochemical methods, but not with incubation studies based on oxygen methods. We stress to the important role of deep layers, below the euphotic layer, in contributing to carbon fixation when incident irradiance at the ocean surface is high (absence of cloud coverage. These deep layers, not considered up to know, might fuel part of the heterotrophic processes in the upper layer, including through dissolved organic carbon. We further demonstrate that, in these extremely clear and stratified waters, integrated gross community production is proportional to the POC content and surface irradiance via an efficiency index ψ GCP*, the water column cross section for Gross Community Production. We finally discuss our results in the context of the role of oligotrophic gyre in the global carbon budget and of the possibility of using optical proxies from space for the development of growth community rather than primary production

  19. Seasonal changes in nutrients, chlorophyll a and the phytoplankton assemblage of the western subarctic gyre in the Pacific Ocean

    Science.gov (United States)

    Mochizuki, Mamiko; Shiga, Naonobu; Saito, Masaru; Imai, Keiri; Nojiri, Yukihiro

    The standing stock and species composition of phytoplankton (>10 μm) were studied using monthly water samples collected at Stn KNOT (Kyodo North Pacific Ocean Time Series; 44°N, 155°E) in the western subarctic gyre in the Pacific Ocean through June 1998 to June 1999 (except for January-April 1999) and January-February 2000. One-liter water samples were preserved in 1% neutrally buffered formalin. Identification and enumeration of phytoplankton were made with an inverted microscope. Nutrients did not appear to be depleted for phytoplakton growth during any season. The vertical distribution of phytoplankton was primarily restricted by the pycnocline, and the bulk of phytoplankton assemblage existed within the surface mixed layer. In July, however, some senescent cells were observed at 200 m. Phytoplankton abundance clearly showed a spring maximum (i.e. spring bloom) in May. The seasonal change in cell numbers, however, did not coincide closely with the change in chlorophyll a concentration. Centric diatoms, which were composed of Thalassiosira, Chaetoceros, and Coscinodiscus, dominated all year round, and showed temporal succession. Pennate diatoms (mostly Neodenticula seminae and Fragilariopsis) increased only during the spring bloom. Dinoflagellates (mostly Gymnodinium and Prorocentrum) were low in abundance, although they increased in summer when the phytoplankton standing stock was low. Silicoflagellate abundance was extremely low. Comparing the annual species composition of phytoplankton between Stn KNOT and Stn P (50°N, 145°W) in the Alaskan Gyre, there was a remarkable difference between the two sites. The phytoplankton assemblage at Stn P is characterized by a high abundance of Rhizosolenia alata and low abundance of Thalassiosira. In contrast, Thalassiosira dominates at Stn KNOT during most seasons.

  20. Seasonality and vertical structure of microbial communities in an ocean gyre.

    Science.gov (United States)

    Treusch, Alexander H; Vergin, Kevin L; Finlay, Liam A; Donatz, Michael G; Burton, Robert M; Carlson, Craig A; Giovannoni, Stephen J

    2009-10-01

    Vertical, seasonal and geographical patterns in ocean microbial communities have been observed in many studies, but the resolution of community dynamics has been limited by the scope of data sets, which are seldom up to the task of illuminating the highly structured and rhythmic patterns of change found in ocean ecosystems. We studied vertical and temporal patterns in the microbial community composition in a set of 412 samples collected from the upper 300 m of the water column in the northwestern Sargasso Sea, on cruises between 1991 and 2004. The region sampled spans the extent of deep winter mixing and the transition between the euphotic and the upper mesopelagic zones, where most carbon fixation and reoxidation occurs. A bioinformatic pipeline was developed to de-noise, normalize and align terminal restriction fragment length polymorphism (T-RFLP) data from three restriction enzymes and link T-RFLP peaks to microbial clades. Non-metric multidimensional scaling statistics resolved three microbial communities with distinctive composition during seasonal stratification: a surface community in the region of lowest nutrients, a deep chlorophyll maximum community and an upper mesopelagic community. A fourth microbial community was associated with annual spring blooms of eukaryotic phytoplankton that occur in the northwestern Sargasso Sea as a consequence of winter convective mixing that entrains nutrients to the surface. Many bacterial clades bloomed in seasonal patterns that shifted with the progression of stratification. These richly detailed patterns of community change suggest that highly specialized adaptations and interactions govern the success of microbial populations in the oligotrophic ocean.

  1. Winter fuels report

    Energy Technology Data Exchange (ETDEWEB)

    1990-10-04

    The Winter Fuels Report is intended to provide concise, timely information to the industry, the press, policymakers, consumers, analysts, and state and local governments on the following topics: distillate fuel oil net production, imports and stocks for all PADD's and product supplied on a US level; propane net production, imports and stocks for Petroleum Administration for Defense Districts (PADD) I, II, and III; natural gas supply and disposition, underground storage, and consumption for all PADD's; residential and wholesale pricing data for propane and heating oil for those states participating in the joint Energy Information Administration (EIA)/State Heating Oil and Propane Program; crude oil price comparisons for the United States and selected cities; and US total heating degree-days by city. This report will be published weekly by the EIA starting the first week in October 1990 and will continue until the first week in April 1991. The data will also be available electronically after 5:00 p.m. on Thursday during the heating season through the EIA Electronic Publication System (EPUB). 12 tabs.

  2. Klaus Winter (1930 - 2015)

    CERN Multimedia

    2015-01-01

    We learned with great sadness that Klaus Winter passed away on 9 February 2015, after a long illness.   Klaus was born in 1930 in Hamburg, where he obtained his diploma in physics in 1955. From 1955 to 1958 he held a scholarship at the Collège de France, where he received his doctorate in nuclear physics under the guidance of Francis Perrin. Klaus joined CERN in 1958, where he first participated in experiments on π+ and K0 decay properties at the PS, and later became the spokesperson of the CHOV Collaboration at the ISR. Starting in 1976, his work focused on experiments with the SPS neutrino beam. In 1984 he joined Ugo Amaldi to head the CHARM experiment, designed for detailed studies of the neutral current interactions of high-energy neutrinos, which had been discovered in 1973 using the Gargamelle bubble chamber at the PS. The unique feature of the detector was its target calorimeter, which used large Carrara marble plates as an absorber material. From 1984 to 1991, Klau...

  3. Winter fuels report

    Energy Technology Data Exchange (ETDEWEB)

    1995-01-13

    The Winter Fuels Report is intended to provide concise, timely information to the industry, the press, policymakers, consumers, analysts, and State and local governments on the following topics: distillate fuel oil net production, imports and stocks on a US level and for all Petroleum Administration for Defense Districts (PADD) and product supplied on a US level; propane net production, imports and stocks on a US level and for PADD`s I, II, and III; natural gas supply and disposition and underground storage for the US and consumption for all PADD`s, as well as selected National average prices; residential and wholesale pricing data for heating oil and propane for those States participating in the joint Energy Information Administration (EIA)/State Heating Oil and Propane Program; crude oil and petroleum price comparisons for the US and selected cities; and a 6-10 day, 30-Day, and 90-Day outlook for temperature and precipitation and US total heating degree-days by city.

  4. Coping with the loss of large, energy-dense prey: a potential bottleneck for Weddell Seals in the Ross Sea.

    Science.gov (United States)

    Salas, Leo; Nur, Nadav; Ainley, David; Burns, Jennifer; Rotella, Jay; Ballard, Grant

    2017-01-01

    Extraction of Antarctic toothfish (Dissostichus mawsoni) in the Ross Sea began in 1997, following a management plan that targets the largest fish with a goal of reducing the spawning biomass by 50% over 35 yr. We investigate the potential long-term consequences of the reduced availability of this prey for Weddell seals (Leptonychotes weddellii). Energy demands in seals are acute, especially immediately following lactation, when females must recover substantial mass and cope with molting costs. We tested the hypothesis that toothfish are critically important for adult female seals during this period. Toothfish body mass is three orders of magnitude greater, and its energy density nearly double that of the most common seal prey, Antarctic silverfish (Pleuragramma antarcticum). Reduction or elimination of toothfish consumption could impair a female's ability to sufficiently recover and successfully produce a pup in the following pupping season. Our goals are to (1) illustrate mechanisms and conditions whereby toothfish depletion might plausibly affect seal population trends; (2) identify measurable parameters of the seals' ecology that may help better understand the potential negative impact of toothfish depletion on seal populations; and (3) promote a precautionary management approach for the fishery that includes monitoring of seal populations We constructed a set of inter-linked models of seal diving behavior, physiological condition, and demography based on existing information. We evaluate the effect of the following factors on seal mass recovery and intrinsic population growth rates: fishery depletion rate, daily diving limits, probability of a successful dive, and body mass recovery target. We show that loss of toothfish has the greatest potential impact on seal populations' growth rate. Under some scenarios, populations may decrease at >10% per year. Critical parameters to better understand fishery impacts include prevalence and size of toothfish in the seals

  5. Evaluating the demographic buffering hypothesis with vital rates estimated for Weddell seals from 30years of mark-recapture data

    Science.gov (United States)

    Rotella, J.J.; Link, W.A.; Chambert, T.; Stauffer, G.E.; Garrott, R.A.

    2012-01-01

    1.Life-history theory predicts that those vital rates that make larger contributions to population growth rate ought to be more strongly buffered against environmental variability than are those that are less important. Despite the importance of the theory for predicting demographic responses to changes in the environment, it is not yet known how pervasive demographic buffering is in animal populations because the validity of most existing studies has been called into question because of methodological deficiencies. 2.We tested for demographic buffering in the southern-most breeding mammal population in the world using data collected from 5558 known-age female Weddell seals over 30years. We first estimated all vital rates simultaneously with mark-recapture analysis and then estimated process variance and covariance in those rates using a hierarchical Bayesian approach. We next calculated the population growth rate's sensitivity to changes in each of the vital rates and tested for evidence of demographic buffering by comparing properly scaled values of sensitivity and process variance in vital rates. 3.We found evidence of positive process covariance between vital rates, which indicates that all vital rates are affected in the same direction by changes in annual environment. Despite the positive correlations, we found strong evidence that demographic buffering occurred through reductions in variation in the vital rates to which population growth rate was most sensitive. Process variation in vital rates was inversely related to sensitivity measures such that variation was greatest in breeding probabilities, intermediate for survival rates of young animals and lowest for survival rates of older animals. 4.Our work contributes to a small but growing set of studies that have used rigorous methods on long-term, detailed data to investigate demographic responses to environmental variation. The information from these studies improves our understanding of life

  6. Evaluating the demographic buffering hypothesis with vital rates estimated for Weddell seals from 30 years of mark-recapture data.

    Science.gov (United States)

    Rotella, Jay J; Link, William A; Chambert, Thierry; Stauffer, Glenn E; Garrott, Robert A

    2012-01-01

    1. Life-history theory predicts that those vital rates that make larger contributions to population growth rate ought to be more strongly buffered against environmental variability than are those that are less important. Despite the importance of the theory for predicting demographic responses to changes in the environment, it is not yet known how pervasive demographic buffering is in animal populations because the validity of most existing studies has been called into question because of methodological deficiencies. 2. We tested for demographic buffering in the southern-most breeding mammal population in the world using data collected from 5558 known-age female Weddell seals over 30 years. We first estimated all vital rates simultaneously with mark-recapture analysis and then estimated process variance and covariance in those rates using a hierarchical Bayesian approach. We next calculated the population growth rate's sensitivity to changes in each of the vital rates and tested for evidence of demographic buffering by comparing properly scaled values of sensitivity and process variance in vital rates. 3. We found evidence of positive process covariance between vital rates, which indicates that all vital rates are affected in the same direction by changes in annual environment. Despite the positive correlations, we found strong evidence that demographic buffering occurred through reductions in variation in the vital rates to which population growth rate was most sensitive. Process variation in vital rates was inversely related to sensitivity measures such that variation was greatest in breeding probabilities, intermediate for survival rates of young animals and lowest for survival rates of older animals. 4. Our work contributes to a small but growing set of studies that have used rigorous methods on long-term, detailed data to investigate demographic responses to environmental variation. The information from these studies improves our understanding of life

  7. Winter Safety Tips for Older Adults

    Science.gov (United States)

    Winter Safety Tips for Older Adults Expert Information from Healthcare Professionals Who Specialize in the Care of ... thick clothing. Think about getting your thermals! –Essential winter wears: hats, gloves or preferably mittens, winter coat, ...

  8. Essential Outdoor Sun Safety Tips for Winter

    Science.gov (United States)

    ... Vitamin D Essential Outdoor Sun Safety Tips for Winter Winter sports enthusiasts are at increased risk for overexposure ... associated with sun exposure. "It's easy to associate winter with frostbite and windburn, but most people are ...

  9. Long-term changes of South China Sea surface temperatures in winter and summer

    Science.gov (United States)

    Park, Young-Gyu; Choi, Ara

    2017-07-01

    Utilizing available atmospheric and oceanographic reanalysis data sets, the long-term trend in South China Sea (SCS) sea surface temperature (SST) between 1950 and 2008 and the governing processes are investigated. Both winter and summer SST increased by comparable amounts, but the warming patterns and the governing processes were different. Strong warming in winter occurred in a deep central area, and during summer in the southern region. In winter the net heat flux into the sea increased, contributing to the warming. The spatial pattern of the heat flux, however, was different from that of the warming. Heat flux increased over the coastal area where warming was weaker, but decreased over the deeper area where warming was stronger. The northeasterly monsoon wind weakened lowering the shoreward Ekman transport and the sea surface height gradient. The cyclonic gyre which transports cold northern water to the south weakened, thereby warming the ocean. The effect was manifested more strongly along the southward western boundary current inducing warming in the deep central part. In summer however, the net surface heat flux decreased and could not contribute to the warming. Over the southern part of the SCS, the weakening of the southwesterly summer monsoon reduced southeastward Ekman transport, which is parallel to the mean SST gradient. Southeastward cold advection due to Ekman transport was reduced, thereby warming the surface near the southeastern boundary of the SCS. Upwelling southeast of Vietnam was also weakened, raising the SST east of Vietnam contributing to the southern summer warming secondarily. The weakening of the winds in each season was the ultimate cause of the warming, but the responses of the ocean that lead to the warming were different in winter and summer.

  10. Spatial variations in microbial community composition in surface seawater from the ultra-oligotrophic center to rim of the South Pacific Gyre.

    Directory of Open Access Journals (Sweden)

    Qi Yin

    Full Text Available Surface seawater in the South Pacific Gyre (SPG is one of the cleanest oceanic environments on earth, and the photosynthetic primary production is extremely low. Despite the ecological significance of the largest aquatic desert on our planet, microbial community composition in the ultra-oligotrophic seawater remain largely unknown. In this study, we collected surface seawater along a southern transect of the SPG during the Integrated Ocean Drilling Program (IODP Expedition 329. Samples from four distinct sites (Sites U1368, U1369, U1370 and U1371 were examined, representing ~5400 kilometers of transect line from the gyre heart to the edge area. Real-time PCR analysis showed 16S rRNA gene abundance in the gyre seawater, ranging from 5.96×10(5 to 2.55×10(6 copies ml(-1 for Bacteria and 1.17×10(3 to 1.90×10(4 copies ml(-1 for Archaea. The results obtained by statistic analyses of 16S rRNA gene clone libraries revealed the community composition in the southern SPG area: diversity richness estimators in the gyre center (Sites U1368 & U1369 are generally lower than those at sites in the gyre edge (Sites U1370 & U1371 and their community structures are clearly distinguishable. Phylogenetic analysis showed the predominance of Proteobacteria (especially Alphaproteobacteria and Cyanobacteria in bacterial 16S rRNA gene clone libraries, whereas phylotypes of Betaproteobacteria were only detected in the central gyre. Archaeal 16S rRNA genes in the clone libraries were predominated by the sequences of Marine Group II within the Euryarchaeota, and the Crenarchaeota sequences were rarely detected, which is consistent with the real-time PCR data (only 9.9 to 22.1 copies ml(-1. We also performed cultivation of heterotrophic microbes onboard, resulting in 18.9% of phylogenetically distinct bacterial isolates at least at the species level. Our results suggest that the distribution and diversity of microbial communities in the SPG surface seawater are closely

  11. A synthesis of the environmental response of the North and South Atlantic Sub-Tropical Gyres during two decades of AMT

    Science.gov (United States)

    Aiken, Jim; Brewin, Robert J. W.; Dufois, Francois; Polimene, Luca; Hardman-Mountford, Nick J.; Jackson, Thomas; Loveday, Ben; Hoya, Silvana Mallor; Dall'Olmo, Giorgio; Stephens, John; Hirata, Takafumi

    2017-11-01

    Anthropogenically-induced global warming is expected to decrease primary productivity in the subtropical oceans by strengthening stratification of the water column and reducing the flux of nutrients from deep-waters to the sunlit surface layers. Identification of such changes is hindered by a paucity of long-term, spatially-resolved, biological time-series data at the basin scale. This paper exploits Atlantic Meridional Transect (AMT) data on physical and biogeochemical properties (1995-2014) in synergy with a wide range of remote-sensing (RS) observations from ocean colour, Sea Surface Temperature (SST), Sea Surface Salinity (SSS) and altimetry (surface currents), combined with different modelling approaches (both empirical and a coupled 1-D Ecosystem model), to produce a synthesis of the seasonal functioning of the North and South Atlantic Sub-Tropical Gyres (STGs), and assess their response to longer-term changes in climate. We explore definitive characteristics of the STGs using data of physical (SST, SSS and peripheral current systems) and biogeochemical variables (chlorophyll and nitrate), with inherent criteria (permanent thermal stratification and oligotrophy), and define the gyre boundary from a sharp gradient in these physical and biogeochemical properties. From RS data, the seasonal cycles for the period 1998-2012 show significant relationships between physical properties (SST and PAR) and gyre area. In contrast to expectations, the surface layer chlorophyll concentration from RS data (CHL) shows an upward trend for the mean values in both subtropical gyres. Furthermore, trends in physical properties (SST, PAR, gyre area) differ between the North and South STGs, suggesting the processes responsible for an upward trend in CHL may vary between gyres. There are significant anomalies in CHL and SST that are associated with El Niño events. These conclusions are drawn cautiously considering the short length of the time-series (1998-2012), emphasising the need

  12. Winter/Summer Monsoon Experiment

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Winter/Summer Monsoon Experiment (MONEX) was conducted during the First Global GARP (Global Atmospheric Research Program) Experiment (FGGE). An international...

  13. Imagery, laboratory analysis and sediment analysis oceanographic data collected aboard the GYRE in the Gulf of Mexico from 2010-09-13 to 2010-09-16 in response to the Deepwater Horizon Oil Spill event (NODC Accession 0084568)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Imagery, laboratory analysis and sediment analysis oceanographic data were collected aboard the GYRE in the Gulf of Mexico from 2010-09-13 to 2010-09-16 in response...

  14. Chemical, physical, profile and other oceanographic data collected aboard the GYRE in the Gulf of Mexico from 2010-09-19 to 2010-09-28 in response to the Deepwater Horizon Oil Spill event (NODC Accession 0074904)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Chemical, physical, profile, imagery, laboratory analysis and sediment analysis oceanographic data were collected aboard the GYRE in the Gulf of Mexico from...

  15. Chemical, physical, profile and other oceanographic data collected aboard the GYRE in the Gulf of Mexico from 2010-10-01 to 2010-10-03 in response to the Deepwater Horizon Oil Spill event (NODC Accession 0074906)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Chemical, physical, profile, imagery, laboratory analysis and sediment analysis oceanographic data were collected aboard the GYRE in the Gulf of Mexico from...

  16. Chemical, physical, profile and other oceanographic data collected aboard the GYRE in the Gulf of Mexico from 2010-09-25 to 2010-09-28 in response to the Deepwater Horizon Oil Spill event (NODC Accession 0074905)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Chemical, physical, profile, imagery, laboratory analysis and sediment analysis oceanographic data were collected aboard the GYRE in the Gulf of Mexico from...

  17. Chemical, physical, profile and other oceanographic data collected aboard the GYRE in the Gulf of Mexico from 2010-10-07 to 2010-10-20 in response to the Deepwater Horizon Oil Spill event (NODC Accession 0069127)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Chemical, physical, profile, imagery, laboratory analysis and sediment analysis oceanographic data were collected aboard the GYRE in the Gulf of Mexico from...

  18. Temperature and other data collected using visual observations and other instruments in the Mid-Atlantic Bight and other Seas from GYRE from 01 August 1985 to 26 May 1990 (NODC Accession 9300074)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature and other data were collected using visual observations, bottle casts, and other instruments from GYRE and other platforms in the Mid-Atlantic Bight and...

  19. Benthic organisms and marine toxic substances and pollutants data collected using net casts and other instruments from the GYRE and other platforms in NW Atlantic Ocean from 11 November 1983 to 30 July 1986 (NODC Accession 8800192)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic organisms and marine toxic substances and pollutants were collected using net casts, sediment sampler, and other instruments from the GYRE and other...

  20. The meaning of nuclear winter

    International Nuclear Information System (INIS)

    Geiger, H.J.

    1987-01-01

    In this paper the author reviews the history and origins of the basic ideas underlying nuclear winter; and findings and predictions of several groups regarding this topic. The author reviews some of the further developments and scientific analyses regarding nuclear winter since the initial announcements of 1983, touching on some of the revisions and controversies and trying to indicate the current status of the field

  1. Uplift rates from a new high-density GPS network in Palmer Land indicate significant late Holocene ice loss in the southwestern Weddell Sea

    DEFF Research Database (Denmark)

    Wolstencroft, Martin; King, Matt A.; Whitehouse, Pippa L

    2015-01-01

    a potentially large correction to account for the isostatic response of the solid Earth to ice-load changes since the Last Glacial Maximum. In this study, we combine glacial isostatic adjustment modelling with a new GPS dataset of solid Earth deformation for the southern Antarctic Peninsula to test the current...... understanding of ice history in this region. A sufficiently complete history of past ice-load change is required for glacial isostatic adjustment models to accurately predict the spatial variation of ongoing solid Earth deformation, once the independently-constrained effects of present-day ice mass loss have...... been accounted for. Comparisons between the GPS data and glacial isostatic adjustment model predictions reveal a substantial misfit. The misfit is localized on the southwestern Weddell Sea, where current ice models under-predict uplift rates by approximately 2 mm yr−1. This under-prediction suggests...

  2. The gastropod-symbiotic sea anemone genus Isosicyonis Carlgren, 1927 (Actiniaria: Actiniidae: a new species from the Weddell Sea (Antarctica that clarifies the taxonomic position of the genus

    Directory of Open Access Journals (Sweden)

    Estefanía Rodríguez

    2008-03-01

    Full Text Available A second species of the sea anemone genus Isosicyonis is described and illustrated from 16 specimens collected in the Weddell Sea (Antarctica on the Polarstern cruises ANT XVII/3, ANT XXI/2 and ANT XXIII/8. Isosicyonis striata n. sp. is easily distinguishable externally from the other species of the genus Isosicyonis alba by its pattern: white longitudinal stripes on the column, oral disc, and tentacles. It is also distinguished by internal features including the retractor muscles, parietobasilar muscles, marginal sphincter muscles, number of mesenteries, and cnidae. The genus Isosycionis is currently only known from the Southern Ocean. Both species of Isosicyonis live in association with a gastropod, with a single sea anemone occupying almost the whole shell of its gastropod host. The description of this new species, and our re-examination of Isosicyonis alba, resolves the controversial higher taxonomic position of the genus, confirming its placement within the Endomyaria.

  3. Biological oceanography, biogeochemical cycles, and pelagic ecosystem functioning of the east-central South Pacific Gyre: focus on Easter Island and Salas y Gómez Island

    OpenAIRE

    Von Dassow , Peter; Collado-Fabbri , Silvana

    2014-01-01

    International audience; The Exclusive Economic Zone of Chile defined by Easter Island and Salas y Gómez Island is in the South Pacific Subtropical Gyre (SPSG), putting it at the center of the most oligotrophic and biomass poor waters in the world. Only 10 biological oceanographic expeditions have entered this zone in 105 years (1905-2010). We review key aspects of the plankton ecosystem and biogeochemical function relevant for the understanding of and conservation planning for marine environm...

  4. Uplift rates from a new high-density GPS network in Palmer Land indicate significant late Holocene ice loss in the southwestern Weddell Sea

    Science.gov (United States)

    Wolstencroft, Martin; King, Matt A.; Whitehouse, Pippa L.; Bentley, Michael J.; Nield, Grace A.; King, Edward C.; McMillan, Malcolm; Shepherd, Andrew; Barletta, Valentina; Bordoni, Andrea; Riva, Riccardo E. M.; Didova, Olga; Gunter, Brian C.

    2015-10-01

    The measurement of ongoing ice-mass loss and associated melt water contribution to sea-level change from regions such as West Antarctica is dependent on a combination of remote sensing methods. A key method, the measurement of changes in Earth's gravity via the GRACE satellite mission, requires a potentially large correction to account for the isostatic response of the solid Earth to ice-load changes since the Last Glacial Maximum. In this study, we combine glacial isostatic adjustment modelling with a new GPS dataset of solid Earth deformation for the southern Antarctic Peninsula to test the current understanding of ice history in this region. A sufficiently complete history of past ice-load change is required for glacial isostatic adjustment models to accurately predict the spatial variation of ongoing solid Earth deformation, once the independently-constrained effects of present-day ice mass loss have been accounted for. Comparisons between the GPS data and glacial isostatic adjustment model predictions reveal a substantial misfit. The misfit is localized on the southwestern Weddell Sea, where current ice models under-predict uplift rates by approximately 2 mm yr-1. This under-prediction suggests that either the retreat of the ice sheet grounding line in this region occurred significantly later in the Holocene than currently assumed, or that the region previously hosted more ice than currently assumed. This finding demonstrates the need for further fieldwork to obtain direct constraints on the timing of Holocene grounding line retreat in the southwestern Weddell Sea and that GRACE estimates of ice sheet mass balance will be unreliable in this region until this is resolved.

  5. Bibliography on Cold Regions Science and Technology, Volume 46, Part 2, 1992

    Science.gov (United States)

    1992-01-01

    eng1 46-1074 Radar backscatter measurements during the Winter Weddell Abramov Glacier and the runoff in its basin (1989. p.85- Aakjaer. P.D. Gyre Study...eng1 46-4917 Xiang. D.X. Meiasurement and characterization of the pressure-sinkage Ice engineering design for marinas 11991. p 524-533. engj Effect t...regime of Global change and the carbon balance of arctic Variation of snow water equivalent and struanflow in the Abramov Glacier and the runofl in its

  6. Sensitivity of North Atlantic subpolar gyre and overturning to stratification-dependent mixing: response to global warming

    Energy Technology Data Exchange (ETDEWEB)

    Marzeion, Ben [Massachusetts Institute of Technology, EAPS, Cambridge, MA (United States); Nansen Environmental and Remote Sensing Center and Bjerknes Centre for Climate Research, Bergen (Norway); University of Innsbruck, Tropical Glaciology Group, Institute of Geography, Innsbruck (Austria); Levermann, Anders [Potsdam University, Earth System Analysis, Potsdam Institute for Climate Impact Research and Institute of Physics, Potsdam (Germany); Mignot, Juliette [Universite Pierre et Marie Curie, LOCEAN, Paris (France)

    2010-04-15

    We use a reduced complexity climate model with a three-dimensional ocean component and realistic topography to investigate the effect of stratification-dependent mixing on the sensitivity of the North Atlantic subpolar gyre (SPG), and the Atlantic meridional overturning circulation (AMOC), to idealized CO{sub 2} increase and peaking scenarios. The vertical diffusivity of the ocean interior is parameterized as {kappa} {proportional_to} N {sup -{alpha}}, where N is the local buoyancy frequency. For all parameter values 0 {<=} {alpha} {<=} 3, we find the SPG, and subsequently the AMOC, to weaken in response to increasing CO{sub 2} concentrations. The weakening is significantly stronger for {alpha} {>=} {alpha}{sub cr} {approx} 1.5. Depending on the value of {alpha}, two separate model states develop. These states remain different after the CO{sub 2} concentration is stabilized, and in some cases even after the CO{sub 2} concentration has been decreased again to the pre-industrial level. This behaviour is explained by a positive feedback between stratification and mixing anomalies in the Nordic Seas, causing a persistent weakening of the SPG. (orig.)

  7. Quantitation of persistent organic pollutants adsorbed on plastic debris from the Northern Pacific Gyre's "eastern garbage patch".

    Science.gov (United States)

    Rios, Lorena M; Jones, Patrick R; Moore, Charles; Narayan, Urja V

    2010-12-01

    Floating marine plastic debris was found to function as solid-phase extraction media, adsorbing and concentrating pollutants out of the water column. Plastic debris was collected in the North Pacific Gyre, extracted, and analyzed for 36 individual PCB congeners, 17 organochlorine pesticides, and 16 EPA priority PAHs. Over 50% contained PCBs, 40% contained pesticides, and nearly 80% contained PAHs. The PAHs included 2, 3 and 4 ring congeners. The PCBs were primarily CB-11, 28, 44, 52, 66, and 101. The pesticides detected were primarily p,p-DDTs and its metabolite, o,p-DDD, as well as BHC (a,b,g and d). The concentrations of pollutants found ranged from a few ppb to thousands of ppb. The types of PCBs and PAHs found were similar to those found in marine sediments. However, these plastic particles were mostly polyethylene which is resistant to degradation and although functioning similarly to sediments in accumulating pollutants, these had remained on or near the ocean surface. Particles collected included intact plastic items as well as many pieces less than 5 mm in size.

  8. New Carbon Source From Microbial Degradation of Pre-Production Resin Pellets from the North Pacific Gyre

    Science.gov (United States)

    Neal, A.; Mielke, R.; Stam, C. N.; Gonsior, M.; Tsapin, A. I.; Lee, G.; Leftwich, B.; Narayan, R.; Coleman, H.; Argyropoulos, N.; Sheavly, S. B.; Gorby, Y. A.

    2011-12-01

    Numerous pollutants are transported through the world's oceans that impact oceanic health. Diffuse sources include land-based runoff, atmospheric depositions, shipping industry wastes, and others. Synthetic polymer marine debris is a multi-faceted problem that includes interactions with environmental toxins, carbon cycling systems, ocean surface chemistry, fine minerals deposition, and nano-particles. The impact that synthetic polymer-microbe interactions have on carbon input into the open ocean is poorly understood. Here we demonstrate that both biotic and abiotic processes contribute to degradation of pre-production resin pellets (PRPs), in open ocean environments and new methodologies to determine carbon loss from this synthetic polymer debris. Our data shows that material degradation of environmental polyethylene PRPs can potentially deposit 13 mg/g to 65 mg/g of carbon per PRP into our marine environments. Environmental pre-production resin pellets were collected on the S/V Kaisei cruise in 2009 which covered over 3,000 nautical miles and sampled over 102,000 m3 of the first 15cm of the water column in the Subtropical Convergence Zone of the North Pacific Gyre. Environmental PRP degradation and the role microbial communities play in this was evaluated using a combination of Fourier transform infrared spectroscopy, environmental scanning electron microscopy, scanning transmission electron microscopy, X-ray microtomography, and ArcGIS mapping. More research is needed to understand the environmental impact of this new carbon source arising from synthetic polymers as they degrade in oceanic environments.

  9. Organic carbon budget for the eastern boundary of the North Atlantic subtropical gyre: major role of DOC in mesopelagic respiration.

    Science.gov (United States)

    Santana-Falcón, Yeray; Álvarez-Salgado, Xosé Antón; Pérez-Hernández, María Dolores; Hernández-Guerra, Alonso; Mason, Evan; Arístegui, Javier

    2017-08-31

    Transports of suspended particulate (POC susp ) and dissolved (DOC) organic carbon are inferred from a box-model covering the eastern boundary of the North Atlantic subtropical gyre. Corresponding net respiration rates (R) are obtained from a net organic carbon budget that is based on the transport estimates, and includes both vertical and lateral fluxes. The overall R in the mesopelagic layer (100-1500 m) is 1.6 ± 0.4 mmol C m -2 d -1 . DOC accounts for up to 53% of R as a result of drawdown of organic carbon within Eastern North Atlantic Central Water (ENACW) that is entrained into sinking Mediterranean Overflow Water (MOW) that leads to formation of Mediterranean water (MW) at intermediate depths (~900 m). DOC represents 90% of the respired non-sinking organic carbon. When converted into oxygen units, the computed net respiration rate represents less than half the oxygen utilization rates (OUR) reported for the mesopelagic waters of the subtropical North Atlantic. Mesoscale processes in the area, not quantified with our approach, could account in part for the OUR differences observed between our carbon budget and other published studies from the North Atlantic, although seasonal or interannual variability could also be responsible for the difference in the estimates.

  10. Plastic ingestion in oceanic-stage loggerhead sea turtles (Caretta caretta) off the North Atlantic subtropical gyre.

    Science.gov (United States)

    Pham, Christopher K; Rodríguez, Yasmina; Dauphin, Axelle; Carriço, Rita; Frias, João P G L; Vandeperre, Frederic; Otero, Vanessa; Santos, Marco R; Martins, Helen R; Bolten, Alan B; Bjorndal, Karen A

    2017-08-15

    Juvenile oceanic-stage sea turtles are particularly vulnerable to the increasing quantity of plastic coming into the oceans. In this study, we analysed the gastrointestinal tracts of 24 juvenile oceanic-stage loggerheads (Caretta caretta) collected off the North Atlantic subtropical gyre, in the Azores region, a key feeding ground for juvenile loggerheads. Twenty individuals were found to have ingested marine debris (83%), composed exclusively of plastic items (primarily polyethylene and polypropylene) identified by μ-Fourier Transform Infrared Spectroscopy. Large microplastics (1-5mm) represented 25% of the total number of debris and were found in 58% of the individuals sampled. Average number of items was 15.83±6.09 (±SE) per individual, corresponding to a mean dry mass of 1.07±0.41g. The results of this study demonstrate that plastic pollution acts as another stressor for this critical life stage of loggerhead turtles in the North Atlantic. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Warmer, deeper, and greener mixed layers in the North Atlantic subpolar gyre over the last 50 years.

    Science.gov (United States)

    Martinez, Elodie; Raitsos, Dionysios E; Antoine, David

    2016-02-01

    Shifts in global climate resonate in plankton dynamics, biogeochemical cycles, and marine food webs. We studied these linkages in the North Atlantic subpolar gyre (NASG), which hosts extensive phytoplankton blooms. We show that phytoplankton abundance increased since the 1960s in parallel to a deepening of the mixed layer and a strengthening of winds and heat losses from the ocean, as driven by the low frequency of the North Atlantic Oscillation (NAO). In parallel to these bottom-up processes, the top-down control of phytoplankton by copepods decreased over the same time period in the western NASG, following sea surface temperature changes typical of the Atlantic Multi-decadal Oscillation (AMO). While previous studies have hypothesized that climate-driven warming would facilitate seasonal stratification of surface waters and long-term phytoplankton increase in subpolar regions, here we show that deeper mixed layers in the NASG can be warmer and host a higher phytoplankton biomass. These results emphasize that different modes of climate variability regulate bottom-up (NAO control) and top-down (AMO control) forcing on phytoplankton at decadal timescales. As a consequence, different relationships between phytoplankton, zooplankton, and their physical environment appear subject to the disparate temporal scale of the observations (seasonal, interannual, or decadal). The prediction of phytoplankton response to climate change should be built upon what is learnt from observations at the longest timescales. © 2015 John Wiley & Sons Ltd.

  12. Coordinated gene expression between Trichodesmium and its microbiome over day-night cycles in the North Pacific Subtropical Gyre.

    Science.gov (United States)

    Frischkorn, Kyle R; Haley, Sheean T; Dyhrman, Sonya T

    2018-04-01

    Trichodesmium is a widespread, N 2 fixing marine cyanobacterium that drives inputs of newly fixed nitrogen and carbon into the oligotrophic ecosystems where it occurs. Colonies of Trichodesmium ubiquitously occur with heterotrophic bacteria that make up a diverse microbiome, and interactions within this Trichodesmium holobiont could influence the fate of fixed carbon and nitrogen. Metatranscriptome sequencing was performed on Trichodesmium colonies collected during high-frequency Lagrangian sampling in the North Pacific Subtropical Gyre (NPSG) to identify possible interactions between the Trichodesmium host and microbiome over day-night cycles. Here we show significantly coordinated patterns of gene expression between host and microbiome, many of which had significant day-night periodicity. The functions of the co-expressed genes suggested a suite of interactions within the holobiont linked to key resources including nitrogen, carbon, and iron. Evidence of microbiome reliance on Trichodesmium-derived vitamin B12 was also detected in co-expression patterns, highlighting a dependency that could shape holobiont community structure. Collectively, these patterns of expression suggest that biotic interactions could influence colony cycling of resources like nitrogen and vitamin B12, and decouple activities, like N 2 fixation, from typical abiotic drivers of Trichodesmium physiological ecology.

  13. Distribution of ultraphytoplankton in the western part of the North Pacific subtropical gyre during a strong La Niña condition: relationship with the hydrological conditions

    Directory of Open Access Journals (Sweden)

    M. Girault

    2013-09-01

    Full Text Available The distribution of ultraphytoplankton was investigated in the western North Pacific Subtropical Gyre (NPSG during La Niña, a cold phase of El Niño Southern Oscillation (ENSO. Observations were conducted in a north-south transect (33.6–13.25° N along the 141.5° E meridian in order to study the ultraplankton assemblages in various oligotrophic conditions. Analyses were performed at the single cell level by analytical flow cytometry. Five ultraphytoplankton groups (Prochlorococcus, Synechococcus, picoeukaryotes, nanoeukaryotes and nanocyanobacteria-like defined by their optical properties were enumerated in three different areas visited during the cruise: the Kuroshio region, the subtropical Pacific gyre and a transition zone between the subtropical Pacific gyre and the Warm pool. Prochlorococcus outnumbered the other photoautotrophs in all the investigated areas. However, in terms of carbon biomass, an increase in the relative contribution of Synechococcus, picoeukaryotes and nanoeukaryotes was observed from the centre of the subtropical gyre to the Kuroshio area. In the Kuroshio region, a peak of abundance of nanoeukaryotes observed at the surface suggested an increase in nutrients likely due to the vicinity of a cold cyclonic eddy. In contrast, in the salinity front along the isohaline 35 and anticyclonic eddy located around 22.83° N, the mainly constant distribution of Prochlorococcus from the surface down to 150 m characterised the dominance by these microorganisms in high salinity and temperature zone. Results suggested that the distribution of nanocyanobacteria-like is also closely linked to the salinity front rather than low phosphate concentration. The maximum abundance of ultraphytoplankton was located above the SubTropical Counter Current (STCC at depths > 100 m where higher nutrient concentrations were measured. Finally, comparison of the ultraphytoplankton concentrations during El Niño (from the literature and La Niña (this

  14. Polonium-210 and lead-210 in the Southern Polar Ocean: Naturally occurring tracers of biological and hydrographical processes in the surface waters of the Antarctic Circumpolar Current and the Weddell Sea

    International Nuclear Information System (INIS)

    Friedrich, J.

    1997-01-01

    In this thesis the distribution of 210 Po and 210 Pb in the upper 600 m of the Antarctic Circumpolar Current and the Weddell Sea was investigated along north-south transects in austral spring and autumn. 210 Po and 210 Pb can serve as sensitive tracers for the special hydrographic conditions of the Antarctic Circumpolar Current and the Weddell Sea as well as for biological processes during phytoplankton blooms. The 210 Po/ 210 Pb disequilibrium was used as a tracer for particle export. This tracer integrates export on a timescale of 276 days because of the 138 day half-life of 210 Po and complements the 234 Th/ 238 U disequilibrium as another tracer for plankton production and export on a shorter timescale of several weeks. (orig.) [de

  15. IDRC Bulletin — Winter 2017

    International Development Research Centre (IDRC) Digital Library (Canada)

    2018-01-16

    Jan 16, 2018 ... In this issue, read the research results from our Safe and Inclusive Cities program and don't forget that the Joint Canada-Israel Health Research Program 2018 call is now open. IDRC Bulletin logo IDRC Bulletin — Winter 2017. Featured this month. View of Port-au-Prince in Haiti, March 30, 2016. Safe and ...

  16. Learning through a Winter's Tale

    Science.gov (United States)

    Vidotto, Kristie

    2010-01-01

    In this article, the author shares her experience during the final semester of Year 11 Theatre Studies when she performed a monologue about Hermione from "The Winter's Tale". This experience was extremely significant to her because it nearly made her lose faith in one of the most important parts of her life, drama. She believes this…

  17. Winter School on Coding Theory

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 8; Issue 8. Winter School on Coding Theory. Information and Announcements Volume 8 Issue 8 August 2003 pp 111-111. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/008/08/0111-0111. Resonance ...

  18. Nuclear Winter: The Continuing Debate.

    Science.gov (United States)

    1987-03-23

    prospect of human annihilation. Speculation about the environmental results of a ’long darkness’ were considered by Paul Ehrlich .10 The term nuclear winter...Washington D.C., 1983 The Cold and the Dark: The World after Nuclear War, by Paul Ehrlich , et al. New York: Norton, 1984. (QH545 N83 C66 1983k Caldicott

  19. Investigating the Trophic Ecology of the Fish Genus Cyclothone in the North Pacific Subtropical Gyre Using Stable Isotope Techniques

    Science.gov (United States)

    Gloeckler, K.; Ko, W.; Choy, C. A.; Hannides, C. C.; Close, H. G.; Popp, B. N.; Drazen, J.

    2016-02-01

    The meso- and bathypelagic fish genus Cyclothone, commonly known as bristlemouths, are the most abundant vertebrates on the planet. Despite their abundance, little is known about their trophic ecology. A few studies have used traditional stomach content analysis and found that the majority of individuals had empty stomachs and a few contained copepod and ostracod remains. We used bulk tissue carbon and nitrogen isotopes, and compound-specific nitrogen isotope analysis of amino acids (AA-CSIA) to investigate the trophic ecology of this genus from individuals collected at Station ALOHA, in the North Pacific Subtropical Gyre. Two cosmopolitan species were abundant, the shallower living Cyclothone alba (425-625 m) and the deeper living Cyclothone pallida (600 - 1300 m), and appear to have different feeding ecologies. While the bulk 13C and 15N contents of C. alba were similar to those of other zooplanktivorous micronekton, the bulk 13C and 15N contents of C. pallida were much higher than those of zooplanktivorous micronekton and suggest either (1) that they feed at a similar trophic level to large predatory fishes such as Thunnus albacares and Coryphaena hipurrus or (2) that the baseline isotopic values of their food web are substantially different. AA-CSIA showed that the trophic position (TP) of C. pallida was 2.3 - 3.2 (±0.28), that is, much lower than the TP of large predatory fishes. Additionally, the δ15N values of the `source' amino acid phenylalanine (d15NPHE) were very high, indicating baseline isotopic values within the range of bacterially-altered suspended particles. Suspended particles have often been overlooked as a significant source of carbon in the deep sea despite discrepancies between the supply of carbon via sinking particles and estimated demand of carbon by deep sea organisms. These results suggest that a suspended particle based food web is important to at least some deep-sea fauna.

  20. Winter movement dynamics of black brant

    Science.gov (United States)

    Lindberg, Mark S.; Ward, David H.; Tibbitts, T. Lee; Roser, John

    2007-01-01

    Although North American geese are managed based on their breeding distributions, the dynamics of those breeding populations may be affected by events that occur during the winter. Birth rates of capital breeding geese may be influenced by wintering conditions, mortality may be influenced by timing of migration and wintering distribution, and immigration and emigration among breeding populations may depend on winter movement and timing of pair formation. We examined factors affecting movements of black brant (Branta bernicla nigricans) among their primary wintering sites in Mexico and southern California, USA, (Mar 1998–Mar 2000) using capture–recapture models. Although brant exhibited high probability (>0.85) of monthly and annual fidelity to the wintering sites we sampled, we observed movements among all wintering sites. Movement probabilities both within and among winters were negatively related to distance between sites. We observed a higher probability both of southward movement between winters (Mar to Dec) and northward movement between months within winters. Between-winter movements were probably most strongly affected by spatial and temporal variation in habitat quality as we saw movement patterns consistent with contrasting environmental conditions (e.g., La Niña and El Niño southern oscillation cycles). Month-to-month movements were related to migration patterns and may also have been affected by differences in habitat conditions among sites. Patterns of winter movements indicate that a network of wintering sites may be necessary for effective conservation of brant.

  1. Wintering ecology of adult North American ospreys

    Science.gov (United States)

    Washburn, Brian E.; Martell, Mark S.; Bierregaard, Richard O.; Henny, Charles J.; Dorr, Brian S.; Olexa, Thomas J.

    2014-01-01

    North American Ospreys (Pandion haliaetus) typically migrate long distances to their wintering grounds in the tropics. Beyond the general distribution of their wintering range (i.e., the Caribbean, South America, and Central America), very little is known about the wintering ecology of these birds. We used satellite telemetry to determine the duration of wintering period, to examine the characteristics of wintering areas used by Ospreys, and to quantify space use and activity patterns of wintering Ospreys. Adult Ospreys migrated to wintering sites and exhibited high wintering site fidelity among years. Overall, Ospreys wintered on river systems (50.6%) more than on lakes (19.0%), and use of coastal areas was (30.4%) intermediate. Ospreys remained on their wintering grounds for an average of 154 d for males and 167 d for females. Locations of wintering Ospreys obtained via GPS-capable satellite telemetry suggest these birds move infrequently and their movements are very localized (i.e., 2 and 1.4 km2, respectively. Overall, our findings suggest wintering adult North American Ospreys are very sedentary, demonstrating a pattern of limited daily movements and high fidelity to a few select locations (presumably roosts). We suggest this wintering strategy might be effective for reducing the risk of mortality and maximizing energy conservation.

  2. Activity report of the 40th Japanese Antarctic Research Expedition wintering party in 1999-2000

    Directory of Open Access Journals (Sweden)

    Hiroshi Miyaoka

    2011-03-01

    Full Text Available The 40th Japanese Antarctic Research Expedition (JARE-40 wintering party, with 40 members, has successfully conducted the third-year project of the Vth five-year JARE program, over the period from 1st February 1999 to 31st January 2000, at Syowa Station, Antarctica.The framework of the JARE-40 wintering party program was the same as those of JARE-38 and JARE-39, comprising three routine observation programs and project/monitoring research observation programs in upper atmospheric physics, atmospheric sciences and glaciology, geophysics, and biology. In addition to many continuing projects, several new observations were started: 50MHz/112MHz aurora radars and a VLF wave receiver as part of the ionosphere program, aerosol sonde observations of Polar Stratospheric Clouds (PSCs as part of the meteorological program, HF/MF radars as part of the upper atmospheric physics program, frequent VLBI experiments as part of the geophysics program, and biological field surveys (including two dives, including monitoring of the undersea behavior of Weddell seals using bio-logging devices.In terms of inland field surveys, two parties were organized: fuel transportation and glaciological/meteorological observations along the route to Mizuho Station in August-September and to Dome Fuji/Yamato air-basecamp in November-January. These surveys involved snow sampling, precise GPS positioning, and sub-glacial surveys using three types of ice radar.Logistical activities, conducted in cooperation with the JARE-40 summer party, included the construction of a second summer lodge, the startup of a second 300 kVA generator and co-generator system, the development of a sewage plant, solar power panels, an access road to the A-heliport, and the cleanup of disused buildings. During the wintering period, efforts were directed towards the maintenance of all facilities at Syowa Station, safety management, and practical support for field operations.The Antarctic Environmental

  3. Classification guide: Sochi 2014 Paralympic Winter Games

    OpenAIRE

    2014-01-01

    The Sochi 2014 Paralympic Winter Games classification guide is designed to provide National Paralympic Committees (NPCs) and International Federations (IFs) with information about the classification policies and procedures that will apply to the Sochi 2014 Paralympic Winter Games.

  4. Decadal Variations of the Western Subarctic Gyre and Main Pycnocline Depth due to Wind Stress Change in the Northern North Pacific

    Science.gov (United States)

    Nagano, A.; Wakita, M.

    2017-12-01

    From the late 1990s to the early 2000s, the western subarctic gyre of the North Pacific, a cyclonic circulation in the western subarctic region, shrank northward associated with a decadal increase of sea surface height (SSH). This gyre change displaced the main pycnocline (halocline) downward and is expected to contribute to the deepening of the overlying temperature minimum layer. This is considered to affect the biogeochemical conditions in the western subarctic region, where is known as substantially slow ocean acidification region. In this study, on the basis of wind stress field data in the subpolar region (40˚N—54˚N, 160˚E—135˚W) during 1979—2014 provided by U.S. National Centers for Environmental Prediction/National Center for Atmospheric Research reanalysis, we estimated the variation in SSH, solving the vorticity gradient equation on the beta plane. Decadal increase in SSH at Station K2 (47˚N, 160˚E), representative point of the western subarctic region, was well produced by the calculation, and the correlation coefficient with altimetric SSH exceeds 0.6. The calculated SSH variation consists of the variations due to the barotropic and baroclinic Rossby wave modes. The gyre shrinkage is found to be caused primarily by the barotropic response to the wind change in the whole subpolar region and secondary by the first baroclinic response. Meanwhile, the decadal deepening of the main pycnocline at K2 is attributed to the baroclinic responses of the higher (second, third, and fourth) vertical modes to the local wind change.

  5. Leadership in American Indian Communities: Winter Lessons

    Science.gov (United States)

    Metoyer, Cheryl A.

    2010-01-01

    Winter lessons, or stories told in the winter, were one of the ways in which tribal elders instructed and directed young men and women in the proper ways to assume leadership responsibilities. Winter lessons stressed the appropriate relationship between the leader and the community. The intent was to remember the power and purpose of that…

  6. Ultraphytoplankton basin-scale distribution in the eastern Mediterranean Sea in winter: link to hydrodynamism and nutrients

    Directory of Open Access Journals (Sweden)

    M. Denis

    2010-07-01

    Full Text Available The basin-scale distribution of ultraphytoplankton (<10 μm was determined in the upper 200 m of the eastern Mediterranean Sea during the winter season. Four clusters were resolved by flow cytometry on the basis of their optical properties and identified as Synechococcus, Prochlorococcus, pico- (<3 μm and nanoeukaryotes (3–10 μm. Synechococcus was the most abundant population (maximum abundance of about 37 000 cells cm−3 and contributed up to 67.7% to the overall ultraphytoplanktonic carbon biomass, whereas the contribution of Prochlorococcus never exceeded 6.5%. The maximum integrated carbon biomass was 1763, 453, 58 and 571 mg C m−2 for nanoeukaryotes, picoeukaryotes, Prochlorococcus and Synechococcus respectively. Water mass properties were analyzed on the basis of temperature and salinity distributions in order to account for the general circulation and locate the main hydrodynamic structures (fronts, gyres, transition between western and eastern basins. The effect of the main hydrodynamic structures and nutrients on the ultraphytoplankton distribution was investigated. No positive correlation between nutrients and phytoplankton could be established when considering large scales. However, below 50 m depth, nutrient ratios between particular stations were correlated to corresponding density ratios. In contrast, significant relationships were found between Synechococcus abundance and density, resulting from the impact of a gyre in southern Adriatic basin and a thermohaline front in the Ionian basin. A significant relationship was also found between picoeukaryotes and salinity in the comparison of western and eastern Mediterranean Sea.

  7. Winter to winter recurrence of atmospheric circulation anomalies over East Asia and its impact on winter surface air temperature anomalies.

    Science.gov (United States)

    Zhao, Xia; Yang, Guang

    2017-01-01

    The persistence of atmospheric circulation anomalies over East Asia shows a winter to winter recurrence (WTWR) phenomenon. Seasonal variations in sea level pressure anomalies and surface wind anomalies display significantly different characteristics between WTWR and non-WTWR years. The WTWR years are characterized by the recurrence of both a strong (weak) anomalous Siberian High and an East Asian winter monsoon over two successive winters without persistence through the intervening summer. However, anomalies during the non-WTWR years have the opposite sign between the current and ensuing winters. The WTWR of circulation anomalies contributes to that of surface air temperature anomalies (SATAs), which is useful information for improving seasonal and interannual climate predictions over East Asia and China. In the positive (negative) WTWR years, SATAs are cooler (warmer) over East Asia in two successive winters, but the signs of the SATAs are opposite in the preceding and subsequent winters during the non-WTWR years.

  8. Hydrography and circulation of the Bay of Bengal during early winter, 1983

    Digital Repository Service at National Institute of Oceanography (India)

    Suryanarayana, A.; Murty, V.S.N.; Rao, D.P.

    flowing eastern boundary current from north of 8 degrees N west of the Andaman-Nicobar Islands and, to its west, a large cyclonic gyre between 19 degrees and 13 degrees N. The wind stress curl for November suggests that this gyre is primarily wind driven...

  9. Communicating Certainty About Nuclear Winter

    Science.gov (United States)

    Robock, A.

    2013-12-01

    I have been spending much of my time in the past several years trying to warn the world about the continuing danger of nuclear weapons, and that the solution is a rapid reduction in the nuclear arsenal. I feel that a scientist who discovers dangers to society has an ethical duty to issue a warning, even if the danger is so scary that it is hard for people to deal with. The debate about nuclear winter in the 1980s helped to end the nuclear arms race, but the planet still has enough nuclear weapons, even after reductions planned for 2017 under the New START treaty, to produce nuclear winter, with temperatures plunging below freezing in the summer in major agricultural regions, threatening the food supply for most of the planet. New research by myself, Brian Toon, Mike Mills, and colleagues over the past six years has found that a nuclear war between any two countries, such as India and Pakistan, using 50 atom bombs each of the size dropped on Hiroshima could produce climate change unprecedented in recorded human history, and a world food crisis because of the agricultural effects. This is much less than 1% of the current global arsenal. Communicating certainty - what we know for sure - has been much more effective than communicating uncertainty. The limited success I have had has come from persistence and serendipity. The first step was to do the science. We have published peer-reviewed articles in major journals, including Science, Nature, Proceedings of the National Academy of Sciences, Journal of Geophysical Research, Atmospheric Chemistry and Physics, Physics Today, and Climatic Change. But policymakers do not read these journals. Through fairly convoluted circumstances, which will be described in this talk, we were able to get papers published in Scientific American and the Bulletin of Atomic Scientists. I have also published several encyclopedia articles on the subject. As a Lead Author of Chapter 8 (Radiative Forcing) of the recently published Fifth Assessment

  10. Winter therapy for the accelerators

    CERN Document Server

    Corinne Pralavorio

    2016-01-01

    Hundreds of people are hard at work during the year-end technical stop as all the accelerators are undergoing maintenance, renovation and upgrade operations in parallel.   The new beam absorber on its way to Point 2 before being lowered into the LHC tunnel for installation. The accelerator teams didn’t waste any time before starting their annual winter rejuvenation programme over the winter. At the end of November, as the LHC ion run was beginning, work got under way on the PS Booster, where operation had already stopped. On 14 December, once the whole complex had been shut down, the technical teams turned their attention to the other injectors and the LHC. The year-end technical stop (YETS) provides an opportunity to carry out maintenance work on equipment and repair any damage as well as to upgrade the machines for the upcoming runs. Numerous work projects are carried out simultaneously, so good coordination is crucial. Marzia Bernardini's team in the Enginee...

  11. The infauna of three widely distributed sponge species (Hexactinellida and Demospongiae) from the deep Ekström Shelf in the Weddell Sea, Antarctica

    Science.gov (United States)

    Kersken, Daniel; Göcke, Christian; Brandt, Angelika; Lejzerowicz, Franck; Schwabe, Enrico; Anna Seefeldt, Meike; Veit-Köhler, Gritta; Janussen, Dorte

    2014-10-01

    Due to their high abundance and large body size sponges have a central position in Antarctic zoobenthos, where they form the most extensive sponge grounds of the world. Though research on Antarctic benthos communities is quite established, research on sponge-associated infauna communities is scarce. We analyzed associated infauna of fifteen individuals of the sponge species Mycale (Oxymycale) acerata Kirkpatrick, 1907 (Demospongiae: Mycalina), Rossella antarctica Carter, 1872 and R. racovitzae Topsent, 1901 (both Hexactinellida: Lyssacinosida). Samples were collected from the deep Ekström Shelf at 602 m in the South-Eastern Weddell Sea, Antarctica, during the ANT XXIV-2 (SYSTCO I) expedition of RV Polarstern. The number of species, α- and β-diversity and the significantly different species composition of infauna communities related to sponge species were calculated, the latter via cluster analysis. The sponge-associated infauna consisted of five phyla: Foraminifera, Nematoda, Polychaeta, Mollusca and Arthropoda. In total 11,463 infaunal specimens were extracted and we found at least 76 associated species. Highest values of α-diversity were calculated for a sample of R. antarctica with a Shannon-Index of 1.84 and Simpson-Index of 0.72 respectively. Our results of the cluster-analysis show significant differences between infauna communities and a unique species composition for single sponge species. Polychaetes of the genus Syllis Lamarck, 1818 were numerous in M. acerata and genera like Pionosyllis Malmgren, 1867 and Cirratulus Lamarck, 1801 were numerous in R. antarctica. Individuals of the amphipod species Seba cf. dubia Schellenberg, 1926 were often found in R. antarctica and R. racovitzae while Colomastix fissilingua Schellenberg, 1926 was frequent in samples of M. acerata. Molluscs were present in M. acerata and R. antarctica but absent in R. racovitzae.

  12. Volume distribution for particles between 3.5 to 2000 μm in the upper 200 m region of the South Pacific Gyre

    Directory of Open Access Journals (Sweden)

    L. Stemmann

    2008-03-01

    Full Text Available The French JGOFS BIOSOPE cruise crossed the South Pacific Gyre (SPG on a transect between the Marquesas Islands and the Chilean coast on a 7500 km transect (8° S–34° S and 8° W–72° W. The number and volume distributions of small (3.5<d<30 μm and large particles (d>100 μm were analysed combining two instruments, the HIAC/Royco Counter (for the small particles and the Underwater Video Profiler (UVP, for the large particles. For the HIAC analysis, samples were collected from 12 L CTD Rosette bottles and immediately analysed on board while the UVP provided an estimate of in situ particle concentrations and size in a continuous profile. Out of 76 continuous UVP and 117 discrete HIAC vertical profiles, 25 had both sets of measurements, mostly at a site close to the Marquesas Islands (site MAR and one in the center of the gyre (site GYR. At GYR, the particle number spectra from few μm to few mm were fit with power relationships having slopes close to −4. At MAR, the high abundance of large objects, probably living organisms, created a shift in the full size spectra of particles such that a single slope was not appropriate. The small particle pool at both sites showed a diel pattern while the large did not, implying that the movement of mass toward the large particles does not take place at daily scale in the SPG area. Despite the relatively simple nature of the number spectra, the volume spectra were more variable because what were small deviations from the straight line in a log-log plot were large variations in the volume estimates. In addition, the mass estimates from the size spectra are very sensitive to crucial parameters such as the fractal dimension and the POC/Dry Weight ratio. Using consistent values for these parameters, we show that the volume of large particles can equal the volume of the smaller particles. However the proportion of material in large particles decreased from the mesotrophic conditions at the

  13. Interactions of dissolved CO

    NARCIS (Netherlands)

    De Baar, H.J.W.; van Heuven, S.M.A.C.; Abouchami, W.; Xue, Z.; Galer, S.J.G.; Rehkämper, M.; Middag, R.; van Ooijen, J.

    2017-01-01

    Here we report the first ever observations of a strong correlation in ocean surface waters of the dissolved δ114Cdwith dissolved CO2. This is observed in the Southern Ocean along the 0°W meridian in both the AntarcticCircumpolar Current and the Weddell Gyre, as well as in the Weddell Sea proper,

  14. 33 CFR 100.109 - Winter Harbor Lobster Boat Race, Winter Harbor, ME.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Winter Harbor Lobster Boat Race, Winter Harbor, ME. 100.109 Section 100.109 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY REGATTAS AND MARINE PARADES SAFETY OF LIFE ON NAVIGABLE WATERS § 100.109 Winter Harbor...

  15. Biological oceanography, biogeochemical cycles, and pelagic ecosystem functioning of the east-central South Pacific Gyre: focus on Easter Island and Salas y Gómez Island

    Directory of Open Access Journals (Sweden)

    Peter von Dassow

    2014-10-01

    Full Text Available The Exclusive Economic Zone of Chile defined by Easter Island and Salas y Gómez Island is in the South Pacific Sub-tropical Gyre (SPSG, putting it at the center of the most oligotrophic and biomass poor waters in the world. Only 10 biological oceanographic expeditions have entered this zone in 105 years (19052010. We review key aspects of the plankton ecosystem and biogeochemical function relevant for the understanding of and conservation planning for marine environments. Plankton production is limited by lack of dissolved inorganic fixed nitrogen, not phosphorous. Higher organic nitrogen levels might be biologically unavailable. Short-term experiments suggested iron is not limiting, yet iron still likely limits nitrogen fixation, and thus production, at longer time scales, as the presence of nitrogen-fixers is exceptionally low compared to other ocean gyres. Plankton function is dominated by the smallest unicellular organisms, picoplankton (<3 μm in diameter. The SPSG represents a center of high biodiversity for picoplankton, as well as heterotrophic organisms such as tinntinids, siphonophores, and possibly amphipods, although data for key zooplankton, such as copepods, are lacking. Many groups exhibit negative relationships between diversity and total plankton biomass. High diversity might result from dispersal from a very large metacommunity and minimal competition within functional groups. Whether an island-mass effect causes a real or apparent increase in plankton biomass around Easter Island must be confirmed by high-resolution sampling in situ. Long-term threats to the planktonic ecosystem may include climate change-enhanced ocean stratification and plastic marine debris accumulation. Finally, priorities for future research are highlighted.

  16. Animals in Winter. Young Discovery Library Series.

    Science.gov (United States)

    de Sairigne, Catherine

    This book is written for children 5 through 10. Part of a series designed to develop their curiosity, fascinate them and educate them, this volume introduces the habits of a variety of animals during the winter. Topics include: (1) surviving during winter, including concepts such as migration, hibernation, and skin color change; (2) changing…

  17. How to Have a Healthy Winter | Poster

    Science.gov (United States)

    Without a doubt, winter is here. Between the icy weather and the recent hustle and bustle of the holidays, everyone is at an increased risk of getting sick. With that in mind, Occupational Health Services has a few simple tips for staying healthy this winter.

  18. Belichten Zantedeschia in winter biedt perspectief

    NARCIS (Netherlands)

    Leeuwen, van P.J.; Trompert, J.P.T.

    2011-01-01

    Zantedeschia produceert in de Nederlandse winter geen bloemen. In de praktijk wordt met assimilatiebelichting wel bloei in de winter verkregen met de cultivar 'Crystal Blush'. Onderzoek door PPO laat zien welke hoeveelheid licht nodig is en dat ook gekleurde Zantedeschia's van een goede kwaliteit

  19. Nuclear Winter: Scientists in the Political Arena

    Science.gov (United States)

    Badash, Lawrence

    2001-03-01

    The nuclear winter phenomenon is used to illustrate the many paths by which scientific advice reaches decision makers in the United States government. Because the Reagan administration was hostile to the strategic policy that the scientific discovery seemed to demand, the leading proponent of nuclear winter, Carl Sagan, used his formidable talent for popularization to reach a larger audience.

  20. 43 CFR 423.37 - Winter activities.

    Science.gov (United States)

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Winter activities. 423.37 Section 423.37 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF RECLAMATION, DEPARTMENT OF THE....37 Winter activities. (a) You must not tow persons on skis, sleds, or other sliding devices with a...

  1. 36 CFR 1002.19 - Winter activities.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Winter activities. 1002.19... RECREATION § 1002.19 Winter activities. (a) Skiing, snowshoeing, ice skating, sledding, innertubing.... (c) Failure to abide by area designations or activity restrictions established under this section is...

  2. 36 CFR 2.19 - Winter activities.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Winter activities. 2.19... RESOURCE PROTECTION, PUBLIC USE AND RECREATION § 2.19 Winter activities. (a) Skiing, snowshoeing, ice... designations or activity restrictions established under this section is prohibited. ...

  3. Chapter 7: Migration and winter ecology

    Science.gov (United States)

    Deborah M. Finch; Jeffrey F. Kelly; Jean-Luc E. Cartron

    2000-01-01

    The willow flycatcher (Empidonax traillii) is a Neotropical migrant that breeds in North America, but winters in Central and northern South America. Little specific information is known about migration and wintering ecology of the southwestern willow flycatcher (E. t. extimus) (Yong and Finch 1997). Our report applies principally...

  4. Interim Report 'Winter smog and traffic'.

    NARCIS (Netherlands)

    Bloemen, H.; Blom, T.; Bogaard, van den C.; Boluyt, N.; Bree, van L.; Brunekreef, B.; Hoek, G.; Zee, van der S.

    1994-01-01

    This report presents a halfway score of the research project "Winter smog and Traffic", one of the themes of the research programme "Air Pollution and Health". A state of the art is presented of the health effects associated with exposure to winter smog and of the toxicological effects caused by the

  5. Aluminium toxicity in winter wheat

    Directory of Open Access Journals (Sweden)

    Szabó A.

    2015-01-01

    Full Text Available Aluminium is the most frequent metal of the earth crust; it occurs mainly as biologically inactive, insoluble deposit. Environmental problems, industrial contaminations and acid rains increase the soil acidity, leading to the mobilization of Al. Half of the world’s potential arable lands are acidic; therefore, Al-toxicity decreases crop productivity. Wheat is a staple food for 35% of the world population. The effects of Al-stress (0.1 mM were studied on winter wheat; seedlings were grown hydroponically, at acidic pH. After two weeks, the root weight was decreased; a significant difference was found in the P- and Ca-content. The shoot weight and element content changed slightly; Al-content in the root was one magnitude higher than in the shoot, while Al-translocation was limited. The root plasma membrane H+-ATPase has central role in the uptake processes; Al-stress increased the Mg2+-ATPase activity of the microsomal fraction.

  6. Application of remotely piloted aircraft systems in observing the atmospheric boundary layer over Antarctic sea ice in winter

    Directory of Open Access Journals (Sweden)

    Marius O. Jonassen

    2015-10-01

    Full Text Available The main aim of this paper is to explore the potential of combining measurements from fixed- and rotary-wing remotely piloted aircraft systems (RPAS to complement data sets from radio soundings as well as ship and sea-ice-based instrumentation for atmospheric boundary layer (ABL profiling. This study represents a proof-of-concept of RPAS observations in the Antarctic sea-ice zone. We present first results from the RV Polarstern Antarctic winter expedition in the Weddell Sea in June–August 2013, during which three RPAS were operated to measure temperature, humidity and wind; a fixed-wing small unmanned meteorological observer (SUMO, a fixed-wing meteorological mini-aerial vehicle, and an advanced mission and operation research quadcopter. A total of 86 RPAS flights showed a strongly varying ABL structure ranging from slightly unstable temperature stratification near the surface to conditions with strong surface-based temperature inversions. The RPAS observations supplement the regular upper air soundings and standard meteorological measurements made during the campaign. The SUMO and quadcopter temperature profiles agree very well and, excluding cases with strong temperature inversions, 70% of the variance in the difference between the SUMO and quadcopter temperature profiles can be explained by natural, temporal, temperature fluctuations. Strong temperature inversions cause the largest differences, which are induced by SUMO's high climb rates and slow sensor response. Under such conditions, the quadcopter, with its slower climb rate and faster sensor, is very useful in obtaining accurate temperature profiles in the lowest 100 m above the sea ice.

  7. The oceanography of winter leads

    Science.gov (United States)

    Morison, J. H.; McPhee, M. G.; Curtin, T. B.; Paulson, C. A.

    1992-07-01

    Leads in pack ice have long been considered important to the thermodynamics of the polar regions. A winter lead affects the ocean around it because it is a density source. As the surface freezes, salt is rejected and forms more dense water which sinks under the lead. This sets up a circulation with freshwater flowing in from the sides near the surface and dense water flowing away from the lead at the base of the mixed layer. If the mixed layer is fully turbulent, this pattern may not occur; rather, the salt rejected at the surface may simply mix into the surface boundary layer. In either event the instability produced at the surface of leads is the primary source of unstable buoyancy flux and, as such, exerts a strong influence on the mixed layer. Here as many as possible of the disparate and almost anecdotal observations of lead oceanography are assembled and combined with theoretical arguments to predict the form and scale of oceanographic disturbances caused by winter leads. The experimental data suggest the velocity disturbances associated with lead convection are about 1-5 cm s-1. These appear as jets near the surface and the base of the mixed layer when ice velocities across the lead are less than about 5 cm s-1. The salinity disturbances are about 0.01 to 0.05 psu. Scaling arguments suggest that the geostrophic currents set up by the lead density disturbances are also of the order of 1-5 cm s-1. The disturbances are most obvious when freezing is rapid and ice velocity is low because the salinity and velocity disturbances in the upper ocean are not smeared out by turbulence. In this vein, lead convection may be characterized at one extreme as free convection in which the density disturbance forces the circulation. At the other extreme, lead convection may be characterized as forced convection in which the density disturbance is mixed rapidly by boundary layer turbulence. The lead number Lo, which is the ratio of the pressure term to the turbulence term in the

  8. Half a Century of Schladming Winter Schools

    International Nuclear Information System (INIS)

    Pietschmann, H.

    2012-01-01

    The Schladming Winter Schools have started as early as in 1962. Over the times the yearly Schools have closely followed the actual developments in nuclear, particle, or more generally, in theoretical physics. Several new achievements have first been dealt with in length in the lectures at the Schladming Winter School. It has seen very prominent lecturers, among them a series of Nobel laureates (some of them reporting on their works even before they got their Nobel prizes). I will try to highlight the role of the Schladming Winter Schools in pro- mulgating new developments of theoretical physics in depth at the lectures given over the past 50 years. (author)

  9. Physical and chemical data collected by bottle and CTD in the Gulf of Mexico from the R/V Gyre and R/V Pelican, April 2004 - July 2009 to help resolve the dominant oceanographic processes that control the timing, duration, and severity of hypoxia of the region (NODC Accession 0088164)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Physical and chemical oceanographic observational data collected by bottle and CTD in the Gulf of Mexico from the R/V Gyre and R/V Pelican, April 2004 - July 2009....

  10. Temperature profile data collected using bottle casts from the GYRE and WECOMA from the NE Pacific Ocean during the International Decade of ocean Exploration / North Pacific Experiment / Hawaii-Tahiti Shuttle (IDOE/NORPAX/HITIS) project, 1979-02-08 to 1980-06-14 (NODC Accession 8600359)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Oceanographic Station Data and temperature, depth, and other data were collected using meteorological sensors, secchi disks, and bottle casts from GYRE and WECOMA in...

  11. Temperature profile data from STD/CTD casts from the GYRE and other platforms from the NW Atlantic Ocean during the International Decade of Ocean Exploration / combination of USSR POLYGON project and US MODE (IDOE/POLYMODE) project, 1978-05-20 to 1978-07-14 (NODC Accession 8600032)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature and salinity profile data were collected using STD/CTD casts from GYRE and other platforms in the NW Atlantic Ocean from May 20, 1978 to July 14, 1978....

  12. Nutrient and physical profile data from four Microbial Exchanges and Coupling in Coastal Atlantic Systems (MECCAS) cruises collected aboard the R/V Gyre at the mouth of the Chesapeake Bay and northern Atlantic Ocean from February 17, 1985 to September 7, 1986 (NODC Accession 8800324)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Microbial Exchanges and Coupling in Coastal Atlantic Systems (MECCAS) cruise data collected aboard the R/V Gyre at the mouth of the Chesapeake Bay and northern...

  13. Physical and other data from current meters, bottle casts, CTD casts, meteorological sensors, and other instruments from the GYRE as part of the Texas-Louisiana Shelf Circulation and Transport Processes Study (LATEX PART A) from 09 April 1992 to 02 October 1994 (NODC Accession 9500056)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Physical and other data were collected from current meters, bottle casts, CTD casts, meteorological sensors, and other instruments from the GYRE from 09 April 1992...

  14. Unusial winter 2011/2012 in Slovakia

    Czech Academy of Sciences Publication Activity Database

    Faško, P.; Lapin, M.; Matejovič, P.; Pecho, Jozef

    2012-01-01

    Roč. 15, č. 1 (2012), s. 19-26 ISSN 1335-339X Institutional support: RVO:68378289 Keywords : winter characteristics * climate variabilit * climate change * global warming Subject RIV: DG - Athmosphere Sciences, Meteorology

  15. Habitat characteristics of wintering Wood Warbler Phylloscopus ...

    African Journals Online (AJOL)

    Habitat characteristics of wintering Wood Warbler Phylloscopus sibilatrix in the Centre Region of Cameroon: conservation implications. Taku Awa II, Tsi A Evaristus, Robin C Whytock, Tsetagho Guilain, John Mallord ...

  16. VT Mean Winter Precipitation - 1971-2000

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) ClimatePrecip_PRECIPW7100 includes mean winter precipitation data (October through March) for Vermont (1971-2000). It's a raster dataset derived...

  17. Winter cooling in the northern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    PrasannaKumar, S.; Prasad, T.G.

    The upper thermo-haline structure and the surface meteorological parameters of the central and eastern Arabian Sea during the inter-monsoon (April-May, 1994) and winter monsoon (February-March, 1995) periods, were analysed to understand physical...

  18. Overview of climatic effects of nuclear winter

    International Nuclear Information System (INIS)

    Jones, E.M.; Malone, R.C.

    1985-01-01

    A general description of the climatic effects of a nuclear war are presented. This paper offers a short history of the subject, a discussion of relevant parameters and physical processes, and a description of plausible nuclear winter scenario. 9 refs

  19. Drought and Winter Drying (Pest Alert)

    Science.gov (United States)

    USDA Forest Service

    Drought and winter drying have periodically caused major damage to trees. Drought reduces the amount of water available in the soil. In the case of winter drying, the water may be in the soil, but freezing of the soil makes the water unavailable to the tree. In both cases, more water is lost through transpiration than is available to the plant. Symptoms of drought and...

  20. Coming to grips with nuclear winter

    International Nuclear Information System (INIS)

    Scherr, S.J.

    1985-01-01

    This editorial examines the politics related to the concept of nuclear winter which is a term used to describe temperature changes brought on by the injection of smoke into the atmosphere by the massive fires set off by nuclear explosions. The climate change alone could cause crop failures and lead to massive starvation. The author suggests that the prospect of a nuclear winter should be a deterrent to any nuclear exchange

  1. Wet winter pore pressures in railway embankments

    OpenAIRE

    Briggs, Kevin M; Smethurst, Joel A; Powrie, William; O'Brien, Anthony S

    2013-01-01

    This paper demonstrates the influence of extreme wet winter weather on pore water pressures within clay fill railway embankments, using field monitoring data and numerical modelling. Piezometer readings taken across the London Underground Ltd network following the wet winter of 2000/2001 were examined, and showed occurrences of hydrostatic pore water pressure within embankments but also many readings below this. A correlation was found between the maximum pore water pressures and the permeabi...

  2. Impact of the blue mussel

    NARCIS (Netherlands)

    Jacobs, P.; Riegman, R.; van der Meer, J.

    2015-01-01

    The accumulation of carbon within the Weddell Gyre and its exchanges across the gyre boundaries are investigated with three recent full-depth oceanographic sections enclosing this climatically important region. The combination of carbon measurements with ocean circulation transport estimates from a

  3. Winter barley mutants created in the Ukraine

    International Nuclear Information System (INIS)

    Zayats, O.M.

    2001-01-01

    Full text: Increasing fodder and protein production is one of the objectives of the development of agriculture in Ukraine. Higher productivity of fodder crops, due to new highly productive varieties, is the means to meet this aim. Winter barley is an important crop for fodder purposes. The climate of the Ukraine is favourable for growing this crop. The areas used for the growth of winter barley are however, small (500,000-550,000 ha) and there is a shortage of good quality varieties. The main aim of the work was therefore to create new varieties of highly productive winter barley, of good quality. The new varieties and mutation lines of winter barley were created under the influence of water solutions of N-nitroso-N-methylurea (NMH - 0,012, 0,005%), N-nitroso-N-ethylurea (NEH - 0,05; 0.025; 0,012%) ethyleneimine (EI - 0,02; 0,01; 0,005%) on winter barley seeds of the varieties of local and foreign selections. On the basis of many years of investigations (1984-94) the following mutations were described: hard-grained, winter-hardiness, earliness, middle-maturity, late-maturity, wide and large leaves, narrow leaves, multinodal, great number of leaves, great number of flowers, strong stem (lodging resistant), tallness, semi-dwarfness, dwarfness, and high productivity. Particularly valuable are mutants with high productivity of green bulk. Their potential yield is 70 t/ha. As a result of the work two varieties of winter barley 'Shyrokolysty' and 'Kormovy' were released into the State register of plant varieties of the Ukraine. The other valuable mutant genotypes are used in cross breeding programmes. (author)

  4. Mid-Holocene Strengthening of the Bering Strait Inflow to the Arctic and its Linkage With the North Atlantic Subpolar Gyre Circulation

    Science.gov (United States)

    Yamamoto, M.; Nam, S. I.; Polyak, L.; Kobayashi, D.; Suzuki, K.; Irino, T.; Shimada, K.

    2017-12-01

    The Bering Strait inflow (BSI) is an important element of the Arctic Ocean circulation system. We report records of the chlorite/illite ratios in three sediment cores from the northern Chukchi Sea providing insights into the long-term dynamics of the BSI during the Holocene. The BSI approximation by the chlorite/illite record, despite a considerable geographic variability, consistently shows intensified flow from the Bering Sea to the Arctic during the middle Holocene, which is attributed primarily to the effect of higher atmospheric pressure over the Aleutian Basin. The intensified BSI was associated with decrease in sea-ice concentrations and increase in marine production, as indicated by biomarker concentrations, suggesting a major influence of the BSI on sea-ice and biological conditions in the Chukchi Sea. Multi-century to millennial fluctuations, presumably controlled by solar activity, were also identified. This middle Holocene strengthening of the BSI was coeval with intense subpolar gyre circulation in the North Atlantic. We propose that the BSI is linked with the North Atlantic circulation via an atmospheric teleconnection between the Aleutian and Icelandic Lows.

  5. Estimating winter survival of winter wheat by simulations of plant frost tolerance

    NARCIS (Netherlands)

    Bergjord Olsen, A.K.; Persson, T.; Wit, de A.; Nkurunziza, L.; Sindhøj, E.; Eckersten, H.

    2018-01-01

    Based on soil temperature, snow depth and the grown cultivar's maximum attainable level of frost tolerance (LT50c), the FROSTOL model simulates development of frost tolerance (LT50) and winter damage, thereby enabling risk calculations for winter wheat survival. To explore the accuracy of this

  6. Key areas for wintering North American herons

    Science.gov (United States)

    Mikuska, T.; Kushlan, J.A.; Hartley, S.

    1998-01-01

    Nearly all North American heron populations are migratory, but details of where they winter are little known. Locations where North American herons winter were identified using banding recovery data. North American herons winter from Canada through northern South America but especially in eastern North America south of New York, Florida, California, Louisiana, Texas, Mexico and Cuba, these areas accounting for 63% of winter recoveries. We identified regions where recoveries for various species clustered as 'key areas.' These forty-three areas constitute a network of areas that hold sites that likely are important to wintering herons. The relative importance of each area and site within the network must be evaluated by further on the ground inventory. Because of biases inherent in the available data, these hypothesized key areas are indicative rather than exhaustive. As a first cut, this network of areas can serve to inform further inventory activities and can provide an initial basis to begin planning for the year-round conservation of North American heron populations.

  7. Contribution of allelopathy and competition to weed suppression by winter wheat, triticale and winter rye

    DEFF Research Database (Denmark)

    Reiss, Antje; Fomsgaard, Inge S.; Mathiassen, Solvejg Kopp

    of competitive traits, such as early vigour, crop height and leaf area index and presence of phytotoxic compounds of the group of benzoxazinoids to weed suppression. Four cultivars of each of the winter cereals wheat, triticale and rye were grown in field experiments at two locations. Soil samples were taken...... 2016. Competitive traits were measured throughout the growing season. Partial least squares regression with weed biomass as response variable was used for modelling. Competitive traits, as well as benzoxazinoid concentrations contributed significantly to the models on winter wheat, winter triticale...... and winter rye data and explained 63, 69 and 58% of the variance in weed biomass in the first two components, respectively. Consequently, it can be concluded that competitive, as well as allelopathic traits, contributed significantly to weed suppressive outcome in winter cereals. This knowledge...

  8. Root development of fodder radish and winter wheat before winter in relation to uptake of nitrogen

    DEFF Research Database (Denmark)

    Wahlström, Ellen Margrethe; Hansen, Elly Møller; Mandel, A.

    2015-01-01

    The nitrate (N) present in soil at the end of autumn is prone to leach during winter and spring in temperate climates if not taken up by plants. In Denmark catch crops are used as a regulatory tool to reduce N leaching and therefore a shift from winter cereals to spring cereals with catch crops has...... occurred. Quantitative data is missing on N leaching of a catch crop compared to a winter cereal in a conventional cereal-based cropping system. The aim of the study was to investigate whether fodder radish (Raphanus sativus L.) (FR) would be more efficient than winter wheat (Triticum aestivum L.) (WW......) at depleting the soil of mineral nitrogen (Nmin) before winter. A secondary aim was to study the agreement between three different root measuring methods: root wash (RW), core break (CB) and minirhizotron (MR). The third aim of the was to correlate the N uptake of FR and WW with RLD. An experiment was made...

  9. Variability in winter climate and winter extremes reduces population growth of an alpine butterfly.

    Science.gov (United States)

    Roland, Jens; Matter, Stephen F

    2013-01-01

    We examined the long-term, 15-year pattern of population change in a network of 21 Rocky Mountain populations of Parnassius smintheus butterflies in response to climatic variation. We found that winter values of the broadscale climate variable, the Pacific Decadal Oscillation (PDO) index, were a strong predictor of annual population growth, much more so than were endogenous biotic factors related to population density. The relationship between PDO and population growth was nonlinear. Populations declined in years with extreme winter PDO values, when there were either extremely warm or extremely cold sea surface temperatures in the eastern Pacific relative to that in the western Pacific. Results suggest that more variable winters, and more frequent extremely cold or warm winters, will result in more frequent decline of these populations, a pattern exacerbated by the trend for increasingly variable winters seen over the past century.

  10. Winter refuge for Aedes aegypti and Ae. albopictus mosquitoes in Hanoi during Winter.

    Science.gov (United States)

    Tsunoda, Takashi; Cuong, Tran Chi; Dong, Tran Duc; Yen, Nguyen Thi; Le, Nguyen Hoang; Phong, Tran Vu; Minakawa, Noboru

    2014-01-01

    Dengue occurs throughout the year in Hanoi, Vietnam, despite winter low temperatures density drastically decreased in winter. Aedes aegypti preferred concrete tanks and this preference increased in winter. Even in winter, the lowest water temperature found in concrete tanks was >14°C, exceeding the developmental zero point of Ae. aegypti. Although jars, drums and concrete tanks were the dominant containers previously (1994-97) in Hanoi, currently the percentage of residences with concrete tanks was still high while jars and drums were quite low. Our study showed that concrete tanks with broken lids allowing mosquitoes access were important winter refuge for Ae. aegypti. We also indicate a concern about concrete tanks serving as foci for Ae. aegypti to expand their distribution in cooler regions.

  11. The engineering approach to winter sports

    CERN Document Server

    Cheli, Federico; Maldifassi, Stefano; Melzi, Stefano; Sabbioni, Edoardo

    2016-01-01

    The Engineering Approach to Winter Sports presents the state-of-the-art research in the field of winter sports in a harmonized and comprehensive way for a diverse audience of engineers, equipment and facilities designers, and materials scientists. The book examines the physics and chemistry of snow and ice with particular focus on the interaction (friction) between sports equipment and snow/ice, how it is influenced by environmental factors, such as temperature and pressure, as well as by contaminants and how it can be modified through the use of ski waxes or the microtextures of blades or ski soles. The authors also cover, in turn, the different disciplines in winter sports:  skiing (both alpine and cross country), skating and jumping, bob sledding and skeleton, hockey and curling, with attention given to both equipment design and on the simulation of gesture and  track optimization.

  12. Prevalence of operator fatigue in winter maintenance operations.

    Science.gov (United States)

    Camden, Matthew C; Medina-Flintsch, Alejandra; Hickman, Jeffrey S; Bryce, James; Flintsch, Gerardo; Hanowski, Richard J

    2018-02-02

    Similar to commercial motor vehicle drivers, winter maintenance operators are likely to be at an increased risk of becoming fatigued while driving due to long, inconsistent shifts, environmental stressors, and limited opportunities for sleep. Despite this risk, there is little research concerning the prevalence of winter maintenance operator fatigue during winter emergencies. The purpose of this research was to investigate the prevalence, sources, and countermeasures of fatigue in winter maintenance operations. Questionnaires from 1043 winter maintenance operators and 453 managers were received from 29 Clear Road member states. Results confirmed that fatigue was prevalent in winter maintenance operations. Over 70% of the operators and managers believed that fatigue has a moderate to significant impact on winter maintenance operations. Approximately 75% of winter maintenance operators reported to at least sometimes drive while fatigued, and 96% of managers believed their winter maintenance operators drove while fatigued at least some of the time. Furthermore, winter maintenance operators and managers identified fatigue countermeasures and sources of fatigue related to winter maintenance equipment. However, the countermeasures believed to be the most effective at reducing fatigue during winter emergencies (i.e., naps) were underutilized. For example, winter maintenance operators reported to never use naps to eliminate fatigue. These results indicated winter maintenance operations are impacted by operator fatigue. These results support the increased need for research and effective countermeasures targeting winter maintenance operator fatigue. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. [Winter sport injuries in childhood (author's transl)].

    Science.gov (United States)

    Hausbrandt, D; Höllwarth, M; Ritter, G

    1979-01-01

    3374 accidents occurring on the field of sport during the years 1975--1977 accounted for 19% of all accidents dealt with at the Institute of Kinderchirurgie in Graz. 51% of the accidents were caused by the typical winter sports: skiing, tobogganing, ice-skating and ski-jumping with skiing accounting for 75% of the accidents. The fracture localization typical of the different kinds of winter sport is dealt with in detail. The correct size and safety of the equipment were found to be particularly important in the prevention of such accidents in childhood.

  14. Severe European winters in a secular perspective

    Science.gov (United States)

    Hoy, Andreas; Hänsel, Stephanie

    2017-04-01

    Temperature conditions during the winter time are substantially shaped by a strong year-to-year variability. European winters since the late 1980s - compared to previous decades and centuries - were mainly characterised by a high temperature level, including recent record-warm winters. Yet, comparably cold winters and severe cold spells still occur nowadays, like recently observed from 2009 to 2013 and in early 2017. Central England experienced its second coldest December since start of observations more than 350 years ago in 2010, and some of the lowest temperatures ever measured in northern Europe (below -50 °C in Lapland) were recorded in January 1999. Analysing thermal characteristics and spatial distribution of severe (historical) winters - using early instrumental data - helps expanding and consolidating our knowledge of past weather extremes. This contribution presents efforts towards this direction. We focus on a) compiling and assessing a very long-term instrumental, spatially widespread and well-distributed, high-quality meteorological data set to b) investigate very cold winter temperatures in Europe from early measurements until today. In a first step, we analyse the longest available time series of monthly temperature averages within Europe. Our dataset extends from the Nordic countries up to the Mediterranean and from the British Isles up to Russia. We utilise as much as possible homogenised times series in order to ensure reliable results. Homogenised data derive from the NORDHOM (Scandinavia) and HISTALP (greater alpine region) datasets or were obtained from national weather services and universities. Other (not specifically homogenised) data were derived from the ECA&D dataset or national institutions. The employed time series often start already during the 18th century, with Paris & Central England being the longest datasets (from 1659). In a second step, daily temperature averages are involved. Only some of those series are homogenised, but

  15. Nuclear winter: The evidence and the risks

    International Nuclear Information System (INIS)

    Greene, O.

    1985-01-01

    Global concern over nuclear extinction, centered on the holocaust itself, now has turned to the more terrifying consequences of a post-war nuclear winter: ''the long-term effects - destruction of the environment, spread of epidemic diseases, contamination by radioactivity, and ... collapse of agriculture-[that] would spread famine and death to every country.'' Nuclear Winter, the latest in a series of studies by a number of different groups is clinical, analytical, systematic, and detailed. Two physicists and biologist analyze the effects on the climate, plants, animals, and living systems; the human costs; the policy implications

  16. Mechanical weed control in organic winter wheat

    OpenAIRE

    Euro Pannacci; Francesco Tei; Marcello Guiducci

    2017-01-01

    Three field experiments were carried out in organic winter wheat in three consecutive years (exp. 1, 2005-06; exp. 2, 2006- 07; exp. 3, 2007-08) in central Italy (42°57’ N - 12°22’ E, 165 m a.s.l.) in order to evaluate the efficacy against weeds and the effects on winter wheat of two main mechanical weed control strategies: i) spring tine harrowing used at three different application times (1 passage at T1, 2 passages at the time T1, 1 passage at T1 followed by 1 passage at T1 + 14 days) in t...

  17. Nuclear winter: The evidence and the risks

    Energy Technology Data Exchange (ETDEWEB)

    Greene, O.

    1985-01-01

    Global concern over nuclear extinction, centered on the holocaust itself, now has turned to the more terrifying consequences of a post-war nuclear winter: ''the long-term effects - destruction of the environment, spread of epidemic diseases, contamination by radioactivity, and ... collapse of agriculture-(that) would spread famine and death to every country.'' Nuclear Winter, the latest in a series of studies by a number of different groups is clinical, analytical, systematic, and detailed. Two physicists and biologist analyze the effects on the climate, plants, animals, and living systems; the human costs; the policy implications.

  18. Stay Safe and Healthy This Winter!

    Centers for Disease Control (CDC) Podcasts

    2010-11-23

    In this podcast for kids, the Kidtastics offer some simple ways to stay safe and healthy during the winter holiday season.  Created: 11/23/2010 by CDC Office of Women’s Health.   Date Released: 11/23/2010.

  19. Music Activities for Lemonade in Winter

    Science.gov (United States)

    Cardany, Audrey Berger

    2014-01-01

    "Lemonade in Winter: A Book About Two Kids Counting Money" is a children's book about math; however, when sharing it in the music classroom, street cries and clapping games emerge. Jenkins' and Karas' book provides a springboard to lessons addressing several music elements, including form, tempo, and rhythm, as well as…

  20. Winter Video Series Coming in January | Poster

    Science.gov (United States)

    The Scientific Library’s annual Summer Video Series was so successful that it will be offering a new Winter Video Series beginning in January. For this inaugural event, the staff is showing the eight-part series from National Geographic titled “American Genius.” 

  1. Winter Wheat Root Growth and Nitrogen Relations

    DEFF Research Database (Denmark)

    Rasmussen, Irene Skovby

    in winter wheat (Triticum aestivum L). Field experiments on the effect of sowing date, N fertilization and cultivars were conducted on a sandy loam soil in Taastrup, Denmark. The root studies were conducted by means of the minirhizotron method. Also, a field experiment on the effect of defoliation and N...

  2. Highway user expectations for ITD winter maintenance.

    Science.gov (United States)

    2014-07-01

    Providing a high Level of Service (LOS) to ensure the safety and mobility for the traveling public is a key objective for winter : maintenance operations. The goal of this research was to obtain a better understanding of Idaho highway users expect...

  3. Winter chemistry of North Slope lakes

    Science.gov (United States)

    Chambers, M. K.; White, D. M.; Lilly, M. R.; Hinzman, L. D.; Hilton, K. M.; Busey, R.

    2006-12-01

    Lakes are important water resources on the North Slope of Alaska. Oilfield exploration and production requires water for facility use as well as transportation. Ice road construction requires winter extraction of fresh water. Since most North Slope lakes are relatively shallow, the quantity and quality of the water remaining under the ice by the end of the winter are important environmental management issues. Currently permits are based on the presence of overwintering fish populations and their sensitivity to low oxygen. Sampling during the winter of 2004 2005 sheds light on the winter chemistry of several pumped lakes and one unpumped lake on the North Slope. Dissolved oxygen, conductivity, pH, and temperature profiles were taken along with ice thickness and water depth measurements. Water samples were extracted and analyzed for Na, Ca, K, Mg, Fe, DOC, and alkalinity in the laboratory. Lake properties, rather than pumping activities, were the best predictors of oxygen depletion, with the highest levels of dissolved oxygen maintained in the lake with the least dissolved constituents. As would be expected, specific conductance increased with depth in the lake while dissolved oxygen decreased with depth. Dissolved oxygen and specific conductance data suggested that the lakes began to refresh in May. The summarized data provides a view of North Slope lake chemistry trends, while continued studies investigate the chemical impacts of pumping North Slope lakes through continued sampling and modeling efforts.

  4. Modeling winter moth Operophtera brumata egg phenology

    NARCIS (Netherlands)

    Salis, Lucia; Lof, Marjolein; Asch, van Margriet; Visser, Marcel E.

    2016-01-01

    Understanding the relationship between an insect's developmental rate and temperature is crucial to forecast insect phenology under climate change. In the winter moth Operophtera brumata timing of egg-hatching has severe fitness consequences on growth and reproduction as egg-hatching has to match

  5. How marketers handled deliveries last winter

    Energy Technology Data Exchange (ETDEWEB)

    1984-10-01

    A special study on how fuel oil marketers handled deliveries last winter is presented. A questionnaire was sent to the marketers asking how many fuel oil trucks they had, how penalties for small deliveries are assessed, and if many customers are calling for a summer fill. The results of the questionnaire are presented.

  6. Impact of warm winters on microbial growth

    Science.gov (United States)

    Birgander, Johanna; Rousk, Johannes; Axel Olsson, Pål

    2014-05-01

    Growth of soil bacteria has an asymmetrical response to higher temperature with a gradual increase with increasing temperatures until an optimum after which a steep decline occurs. In laboratory studies it has been shown that by exposing a soil bacterial community to a temperature above the community's optimum temperature for two months, the bacterial community grows warm-adapted, and the optimum temperature of bacterial growth shifts towards higher temperatures. This result suggests a change in the intrinsic temperature dependence of bacterial growth, as temperature influenced the bacterial growth even though all other factors were kept constant. An intrinsic temperature dependence could be explained by either a change in the bacterial community composition, exchanging less tolerant bacteria towards more tolerant ones, or it could be due to adaptation within the bacteria present. No matter what the shift in temperature tolerance is due to, the shift could have ecosystem scale implications, as winters in northern Europe are getting warmer. To address the question of how microbes and plants are affected by warmer winters, a winter-warming experiment was established in a South Swedish grassland. Results suggest a positive response in microbial growth rate in plots where winter soil temperatures were around 6 °C above ambient. Both bacterial and fungal growth (leucine incorporation, and acetate into ergosterol incorporation, respectively) appeared stimulated, and there are two candidate explanations for these results. Either (i) warming directly influence microbial communities by modulating their temperature adaptation, or (ii) warming indirectly affected the microbial communities via temperature induced changes in bacterial growth conditions. The first explanation is in accordance with what has been shown in laboratory conditions (explained above), where the differences in the intrinsic temperature relationships were examined. To test this explanation the

  7. Holocene dynamics in the Bering Strait inflow to the Arctic and the Beaufort Gyre circulation based on sedimentary records from the Chukchi Sea

    Directory of Open Access Journals (Sweden)

    M. Yamamoto

    2017-09-01

    Full Text Available The Beaufort Gyre (BG and the Bering Strait inflow (BSI are important elements of the Arctic Ocean circulation system and major controls on the distribution of Arctic sea ice. We report records of the quartz ∕ feldspar and chlorite ∕ illite ratios in three sediment cores from the northern Chukchi Sea, providing insights into the long-term dynamics of the BG circulation and the BSI during the Holocene. The quartz ∕ feldspar ratio, interpreted as a proxy of the BG strength, gradually decreased during the Holocene, suggesting a long-term decline in the BG strength, consistent with an orbitally controlled decrease in summer insolation. We propose that the BG rotation weakened as a result of the increasing stability of sea-ice cover at the margins of the Canada Basin, driven by decreasing insolation. Millennial to multi-centennial variability in the quartz ∕ feldspar ratio (the BG circulation is consistent with fluctuations in solar irradiance, suggesting that solar activity affected the BG strength on these timescales. The BSI approximation by the chlorite ∕ illite record, despite a considerable geographic variability, consistently shows intensified flow from the Bering Sea to the Arctic during the middle Holocene, which is attributed primarily to the effect of higher atmospheric pressure over the Aleutian Basin. The intensified BSI was associated with decrease in sea-ice concentrations and increase in marine production, as indicated by biomarker concentrations, suggesting a major influence of the BSI on sea-ice and biological conditions in the Chukchi Sea. Multi-century to millennial fluctuations, presumably controlled by solar activity, were also identified in a proxy-based BSI record characterized by the highest age resolution.

  8. Holocene dynamics in the Bering Strait inflow to the Arctic and the Beaufort Gyre circulation based on sedimentary records from the Chukchi Sea

    Science.gov (United States)

    Yamamoto, Masanobu; Nam, Seung-Il; Polyak, Leonid; Kobayashi, Daisuke; Suzuki, Kenta; Irino, Tomohisa; Shimada, Koji

    2017-09-01

    The Beaufort Gyre (BG) and the Bering Strait inflow (BSI) are important elements of the Arctic Ocean circulation system and major controls on the distribution of Arctic sea ice. We report records of the quartz / feldspar and chlorite / illite ratios in three sediment cores from the northern Chukchi Sea, providing insights into the long-term dynamics of the BG circulation and the BSI during the Holocene. The quartz / feldspar ratio, interpreted as a proxy of the BG strength, gradually decreased during the Holocene, suggesting a long-term decline in the BG strength, consistent with an orbitally controlled decrease in summer insolation. We propose that the BG rotation weakened as a result of the increasing stability of sea-ice cover at the margins of the Canada Basin, driven by decreasing insolation. Millennial to multi-centennial variability in the quartz / feldspar ratio (the BG circulation) is consistent with fluctuations in solar irradiance, suggesting that solar activity affected the BG strength on these timescales. The BSI approximation by the chlorite / illite record, despite a considerable geographic variability, consistently shows intensified flow from the Bering Sea to the Arctic during the middle Holocene, which is attributed primarily to the effect of higher atmospheric pressure over the Aleutian Basin. The intensified BSI was associated with decrease in sea-ice concentrations and increase in marine production, as indicated by biomarker concentrations, suggesting a major influence of the BSI on sea-ice and biological conditions in the Chukchi Sea. Multi-century to millennial fluctuations, presumably controlled by solar activity, were also identified in a proxy-based BSI record characterized by the highest age resolution.

  9. Nuclear Winter: The implications for civil defense

    International Nuclear Information System (INIS)

    Chester, C.V.; Perry, A.M.; Hobbs, B.F.

    1987-01-01

    ''Nuclear Winter'' is the term given to hypothesized cooling in the northern hemisphere following a nuclear war due to injection of smoke from burning cities into the atmosphere. The voluminous literature on this subject produced since the original paper in 1983 by Turco, Toon, Ackerman, Pollack, and Sagen (TTAPS) has been reviewed. The widespread use of 3-dimensional global circulation models have resulted in reduced estimates of cooling; 15 to 25 0 C for a summer war and a few degrees for a winter war. More serious may be the possibility of suppression of convective precipitation by the altered temperature profiles in the atmosphere. However, very large uncertainties remain in input parameters, the models, and the results of calculations. We believe the state of knowledge about nuclear winter is sufficiently developed to conclude: Neither cold nor drought are likely to be direct threats to human survival for populations with the wherewithal to survive normal January temperatures; The principal threat from nuclear winter is to food production, and could present problems to third parties without food reserves; and Loss of a crop year is neither a new nor unexpected threat from nuclear war to the US and the Soviet Union. Both have at least a year's food reserve at all times. Both face formidable organizational problems in distributing their reserves in a war-damaged environment. The consequences of nuclear winter could be expected to fall more heavily on the Soviet Union than the US due to its higher latitude and less productive agriculture. This may be especially true if disturbances of rainfall amounts and distribution persist for more than a year. 6 refs

  10. Nuclear Winter: Implications for civil defense

    Energy Technology Data Exchange (ETDEWEB)

    Chester, C.V.; Perry, A.M.; Hobbs, B.F.

    1988-05-01

    ''Nuclear Winter'' is the term given to the cooling hypothesized to occur in the Northern Hemisphere following a nuclear war as the result of the injection of smoke from burning cities into the atmosphere. The voluminous literature on this subject produced since the paper was published in 1983 by Turco, Toon, Ackerman, Pollack, and Sagen (TTAPS) has been reviewed. Three-dimensional global circulation models have resulted in reduced estimates of cooling---15 to 25/degree/C for a summer war and a few degrees for a winter war. More serious may be the possibility of suppression of convective precipitation by the altered temperature profiles in the atmosphere. However, very large uncertainties remain in input parameters, the models, and the results of calculations. We believe the state of knowledge about nuclear winter is sufficiently developed to conclude: Neither cold nor drought is likely to be a direct threat to human survival for populations with the wherewithal to survive normal January temperatures. The principal threat from nuclear winter is to food production, and this could present problems to third parties who are without food reserves. Loss of a crop year is neither a new nor an unexpected threat from nuclear war to the United States and the Soviet Union. Both have at least a year's food reserve at all times. Both face formidable organizational problems in distributing their reserves in a war-damaged environment. The consequences of nuclear winter could be expected to fall more heavily on the Soviet Union than the United States due to its higher latitude and less productive agriculture. This may be especially true if disturbances of rainfall amounts and distribution persist for more than a year.

  11. Toward enabling winter occupations: testing a winter coat designed for older adults.

    Science.gov (United States)

    Green, Stephanie L; Boger, Jennifer N; Mihailidis, Alex

    2011-02-01

    Previous research indicates that older adults have difficulties using winter clothing, which contributes to their risk of isolation during winter. Research has also shown that a winter coat that requires less flexibility, strength, and dexterity would help support this population. This pilot study evaluated the measured and perceived effectiveness of a winter coat prototype that had a funnel sleeve design. Eight older adults trialed three coats (the participant's own coat, a coat fitted with sleeve gripper, and the prototype coat), which were evaluated though shoulder range of motion measurements and by the participant completing a survey. Less shoulder range of motion was used to put on the prototype coat. Survey findings support range of motion data that Sleeve Gripper has limited utility. A funnel sleeve design may require less range of motion at the shoulder compared to other coats.

  12. India Annual Winter Cropped Area, 2001-2016

    Data.gov (United States)

    National Aeronautics and Space Administration — India Annual Winter Cropped Area, 2001 - 2016 consists of annual winter cropped areas for most of India (except the Northeastern states) from 2000-2001 to 2015-2016....

  13. AGA predicts winter jump in residential gas price

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    The American Gas Association predicts the average heating bill for residential gas consumers could increase by as much as 18% this winter. AGA Pres. Mike Baly said, Last year's winter was warmer than normal. If the 1992-93 winter is similar, AGA projects that residential natural gas heating bills will go up about 6%. If we see a return to normal winter weather, our projection show the average bill could rise by almost 18%

  14. Seed wintering and deterioration characteristics between weedy and cultivated rice

    OpenAIRE

    Baek, Jung-Sun; Chung, Nam-Jin

    2012-01-01

    Background Incidences of weedy rice continuously occurred in paddy fields because its shattering seeds were able to over-winter. In this research, the seed deterioration of weedy rice was investigated compared with cultivated rice, and the wintering characteristics of these two types of rice were investigated with the field wintering test, freezing resistance test, and accelerated aging test. Results For the wintering test, the seeds of weedy rice were placed on the soil surface of a paddy wi...

  15. Measuring Transpiration to Regulate Winter Irrigation Rates

    Energy Technology Data Exchange (ETDEWEB)

    Samuelson, Lisa [Auburn University

    2006-11-08

    Periodic transpiration (monthly sums) in a young loblolly pine plantation between ages 3 and 6 was measured using thermal dissipation probes. Fertilization and fertilization with irrigation were better than irrigation alone in increasing transpiration of young loblolly pines during winter months, apparently because of increased leaf area in fertilized trees. Irrigation alone did not significantly increase transpiration compared with the non-fertilized and non-irrigated control plots.

  16. Catastrophic winter storms. An escalating problem

    Energy Technology Data Exchange (ETDEWEB)

    Changnon, S.A. [Changnon Climatologist, Mahomet, IL 61853 (United States)

    2007-09-15

    Winter storms are a major weather problem in the USA and their losses have been rapidly increasing. A total of 202 catastrophic winter storms, each causing more than $1 million in damages, occurred during 1949-2003, and their losses totaled $35.2 billion (2003 dollars). Catastrophic winter storms occurred in most parts of the contiguous USA, but were concentrated in the eastern half of the nation where 88% of all storm losses occurred. They were most frequent in the Northeast climate district (95 storms), and were least frequent in the West district (14 catastrophic storms). The annual average number of storms is 3.7 with a 1-year high of 9 storms, and 1 year had no storms. Temporal distributions of storms and their losses exhibited considerable spatial variability across the nation. For example, when storms were very frequent in the Northeast, they were infrequent elsewhere, a result of spatial differences in storm-producing synoptic weather conditions over time. The time distribution of the nation's 202 storms during 1949-2003 had a sizable downward trend, whereas the nation's storm losses had a major upward trend for the 55-year period. This increase over time in losses, given the decrease in storm incidences, was a result of significant temporal increases in storm sizes and storm intensities. Increases in storm intensities were small in the northern sections of the nation, but doubled across the southern two-thirds of the nation, reflecting a climatic shift in conditions producing intense winter storms.

  17. Postharvest tillage reduces Downy Brome infestations in winter wheat

    Science.gov (United States)

    In the Pacific Northwest, downy brome continues to infest winter wheat producing regions especially in low-rainfall areas where the winter wheat-summer fallow rotation is the dominate production system. In Washington, a study was conducted for 2 years at each of two locations in the winter wheat -su...

  18. An NOy Algorithm for Arctic Winter 2000

    Science.gov (United States)

    Loewenstein, M.; Jost, H.; Greenblatt, J. B.; Podolske, J. R.; Gao, R. S.; Popp, P. J.; Toon, G. C.; Webster, C. R.; Herman, R. L.; Hurst, D. F.; hide

    2000-01-01

    NOy, total reactive nitrogen, and the long-lived tracer N2O, nitrous oxide, were measured by both in situ and remote sensing instruments during the Arctic winter 1999-2000 SAGE III Ozone Loss and Validation Experiment (SOLVE). The correlation function NOy:N2O observed before the winter Arctic vortex forms, which is known as NOy(sup), is an important reference relationship for conditions in the evolving vortex. NOy(sup) can, with suitable care, be used to quantify vortex denitrification by sedimentation of polar stratospheric cloud particles when NOy data is taken throughout the winter. Observed NOy values less than the reference value can be interpreted in terms of semi-permanent removal of active nitrogen by condensation and sedimentation processes. In this paper we present a segmented function representing NOy(sup) applicable over the full range of altitudes sampled during SOLVE. We also assess the range of application of this function and some of its limitations.

  19. The influence of sowing period and seeding norm on autumn vegetation, winter hardiness and yield of winter cereal crops

    Directory of Open Access Journals (Sweden)

    Potapova G. N.

    2017-10-01

    Full Text Available the winter wheat and triticale in the middle part of the Ural Mountains haven’t been seeded before. The technology of winter crop cultivation should be improved due to the production of new varieties of winter rye. Winter hardiness and yield of winter rye are higher in comparison with winter triticale and especially with winter wheat. The sowing period and the seeding rate influence the amount of yield and winter hardiness. The winter hardiness of winter cereals and the yield of the rye variety Iset sowed on August 25 and the yield of the triticale variety Bashkir short-stalked and wheat Kazanskaya 560 sowed on August 15 were higher. It is important to sow winter grain in local conditions in the second half of August. The sowing this period allows to provide plants with the necessary amount of positive temperatures (450–500 °C. This helps the plants to form 3–4 shoots of tillering and a mass of 10 dry plants reaching 3–5 grams. The winter grain crops in the middle part of the Ural Mountains should be sown with seeding rates of 6 and 7 million of sprouting grains per 1 ha, and the seeds must be cultivated with fungicidal preparation before seeding.

  20. Sources and transformation of dissolved and particulate organic nitrogen in the North Pacific Subtropical Gyre indicated by compound-specific δ15N analysis of amino acids

    Science.gov (United States)

    Yamaguchi, Yasuhiko T.; McCarthy, Matthew D.

    2018-01-01

    This study explores the use of compound-specific nitrogen isotopes of amino acids (δ15NAA) of coupled dissolved and particulate organic nitrogen (DON, PON) samples as a new approach to examine relative sources, transformation processes, and the potential coupling of these two major forms of N cycle in the ocean water column. We measured δ15NAA distributions in high-molecular-weight dissolved organic nitrogen (HMW DON) and suspended PON in the North Pacific Subtropical Gyre (NPSG) from surface to mesopelagic depths. A new analytical approach achieved far greater δ15NAA measurement precision for DON than earlier work, allowing us to resolve previously obscured differences in δ15NAA signatures, both with depth and between ON pools. We propose that δ15N values of total hydrolysable amino acids (THAA) represents a proxy for proteinaceous ON δ15N values in DON and PON. Together with bulk δ15N values, this allows δ15N values and changes in bulk, proteinaceous, and ;other-N; to be directly evaluated. These novel measurements suggest three main conclusions. First, the δ15NAA signatures of both surface and mesopelagic HMW DON suggest mainly heterotrophic bacterial sources, with mesopelagic HMW DON bearing signatures of far more degraded material compared to surface material. These results contrast with a previous proposal that HMW DON δ15NAA patterns are essentially ;pre-formed; by cyanobacteria in the surface ocean, undergo little change with depth. Second, different δ15NAA values and patterns of HMW DON vs. suspended PON in the surface NPSG suggest that sources and cycling of these two N reservoirs are surpisingly decoupled. Based on molecular δ15N signatures, we propose a new hypothesis that production of surface HMW DON is ultimately derived from subsurface nitrate, while PON in the mixed layer is strongly linked to N2 fixation and N recycling. In contrast, the comparative δ15NAA signatures of HMW DON vs. suspended PON in the mesopelagic also suggest a

  1. Ekman currents and Mixed Layer depth in the North Atlantic subtropical gyre. Observations and Mercator analysis PSY2V4R2-R4.

    Science.gov (United States)

    Sommer, Anna; Reverdin, Gilles; Boutin, Jacqueline; Drillet, Yann

    2017-04-01

    The study is focused on the ocean currents and was motivated by estimating the role of Ekman transport in seasonal salinity variability in the North Atlantic subtropical gyre region of maximum salinity (SSS-max region). Traditionally, one separates in the 'low frequency currents', geostrophic and Ekman components (stationary response to wind stress). The surface geostrophic part can be estimated from altimetry, and estimates of 'residuals' ('Ekman') are available at 15m from drifts of drogued SVP drifters. However, direct estimates are usually not available at other depths, and there is an issue with its vertical structure, and how deep it extends. Thus, we also examined Mercator analysis PSYV4R2-R4 for the same period and region (August 2012-July 2014). We show the comparison of average Ekman currents in ML estimated by the widely used formula τei∗90- ρfh (where h is MLD) and residual currents (difference between total current in ML and geostrophic current estimated from SSH) in Mercator analysis PSYV4R2-R4. Residual Mercator current averaged in ML is larger than the Ekman current estimated by the formula, with RMS differences on the order of 0.02 m/s. Part of the difference can be due to the increments in Mercator data assimilation that we expect to be small at the weekly time scales that we consider. The differences can also result from Ekman transport penetrating below MLD (h). The issue might come from MLD not always coinciding with the Ekman Depth and in the weekly averaging. We also find a difference in the behavior of the Ekman currents at 15m between drifters and the Mercator analysis. Such differences strongly modify how Ekman contributes to advection and salinity variability in the ML. For example, Ekman advection estimated from Mercator analysis for the period August 2012-December 2014 in this SSS-max region is -0.88 pss/yr compared to what we would deduce from observations and the formula τei∗90- ρfh, which is estimated as -0.17 pss/yr.

  2. Spectrum of winter dermatoses in rural Yemen.

    Science.gov (United States)

    Al-Kamel, Mohamed A

    2016-05-01

    Surveys that have been carried out to determine the prevalence of skin diseases in rural Yemen are scarce or not available. To investigate the spectrum of winter dermatoses in a rural Yemeni community. A retrospective study was conducted at the dermatology outpatient clinic of the Al-Helal Specialized Hospital (Radaa' district of Al Bayda' Governorate) using data analysis of 700 selected records of patients managed during four months of the 2013-14 winter season. Seven hundred patients with 730 diseases were reported in this study; the major bulk of patients (46.57%) were in the >18-40-year age group, and females outnumbered males. By far, dermatitis, eczematous, and allergic disorders (38.49%) topped the list of the most frequent skin disorders groups, followed by skin infections and infestations (20%) and the pigmentary disorders (13.70%) group. Contact dermatitis (10.68%) was the most prevalent skin disorder, followed by hyperpigmentations (8.77%), acne (8.08%), viral infections (5.75%), atopic dermatitis (5.62%), and parasitic infestations (5.34%). This survey has documented the spectrum of winter dermatoses in a rural Yemeni community but also reflects the pattern of common dermatoses in the whole country. Dermatitis, eczematous, and allergic disorders, skin infections, and pigmentary disorders are the commonest groups. Contact dermatitis is the most prevalent disorder, and leishmaniasis is the most prevalent skin infectious disease. Climate, occupational, social, and environmental factors are the main contributors. Such statistics can form an important basis for community-based health policies. © 2015 The International Society of Dermatology.

  3. Does Zoning Winter Recreationists Reduce Recreation Conflict?

    Science.gov (United States)

    Miller, Aubrey D.; Vaske, Jerry J.; Squires, John R.; Olson, Lucretia E.; Roberts, Elizabeth K.

    2017-01-01

    Parks and protected area managers use zoning to decrease interpersonal conflict between recreationists. Zoning, or segregation, of recreation—often by non-motorized and motorized activity—is designed to limit physical interaction while providing recreation opportunities to both groups. This article investigated the effectiveness of zoning to reduce recreation conflict in the Vail Pass Winter Recreation Area in Colorado, USA. Despite a zoning management system, established groomed travel routes were used by both non-motorized recreationists (backcountry skiers, snowboarders, snowshoers) and motorized recreationists (snowmobilers). We hypothesized that persistent recreation conflict reported by non-motorized recreationists was the result of recreation occurring in areas of mixed non-motorized and motorized use, mostly along groomed routes. We performed a geospatial analysis of recreation [from Global Positioning System (GPS) points, n = 1,233,449] in the Vail Pass Winter Recreation Area to identify areas of mixed non-motorized and motorized use. We then surveyed non-motorized recreationists ( n = 199) to test whether reported conflict is higher for respondents who traveled in areas of mixed-use, compared with respondents traveling outside areas of mixed-use. Results from the geospatial analysis showed that only 0.7 % of the Vail Pass Winter Recreation Area contained recreation from both groups, however that area contained 14.8 % of all non-motorized recreation and 49.1 % of all motorized recreation. Survey analysis results showed higher interpersonal conflict for all five standard conflict variables among non-motorized respondents who traveled in areas of mixed-use, compared with those traveling outside mixed-use areas. Management implications and recommendations for increasing the effectiveness of zoning are provided.

  4. CARROT SEED GROWING THROUGH WINTERING SEEDLINGS

    Directory of Open Access Journals (Sweden)

    A. P. Zvedenuk

    2017-01-01

    Full Text Available The results of research work on carrot seed growing through wintering seedlings carried out at laboratory of seed studies and seed production of Transnistrian Research Institute of Agriculture, on the soil of the first terrace at the rive Dniester were presented in the article. Seed bearing plants of garden carrot ‘Krasavka’ were the object of the study. The seeds were sown to produce the seedlings on 15-16 August. In the first decade of December the plants were covered with white agrotextile with density 23g/m2 that was removed at the beginning of April. The proportion of plant that passed the winter depending on a year of cultivation was 95-100% under argotextile, and 50-80% in open plot. The plants under agrotextile reached 28 cm a high and had 5-7 well-developed leaves, while those on the open plot were at phase of active foliage growing about 10-13 cm. long. Thus, for early mechanized planting in optimal terms the wintering seedlings grown under agrotextile had the best biometrical characteristics. Moreover the outcome of carrot seedlings was 1.2-1.25 million per hectare. Such quantity of seedlings was sufficient to plant 9-10 ha of carrot plants, where the coefficient of multiplication reached 9-10, and only 3 when growing seeds through mother plant as biennial culture. Viability of seed plants grown through seedlings was 100%. Losses of plant with weight 120-150 grams from damage caused by diseases was 23%. The seed yield, when growing seedlings was 639 kg/ha, but growing through plants was 332 kg/ha. The seed outcome suitable for precise mechanized sowing through seedling growing was 77%, where seed germination was 90%, with seed fraction 1.51 and >2.0 mm. It was essentially improved their yielding characteristics. Seed outcome from this fraction obtained through planting method was 32%. The proportion of seeds in fraction 1-1.5 mm was 68%. For mechanized single-seed sowing, the seeds can be used only after mini-coating. The seed

  5. Efficiency of foliar dressing of winter wheat

    Directory of Open Access Journals (Sweden)

    Л. В. Худолій

    2017-06-01

    Full Text Available Purpose. To elaborate winter wheat cultivation technologies based on balanced fertilizer system that combines application of mineral fertilizers and the increase of their efficiency by the use of preparations with microelements. Methods. Field and laboratory studies, mathematical and statistical analysis. Results. During 2011–2013, the effect of cultivation technologies on the formation of yield and quality of winter wheat varie­ty ‘Benefis’ (pea is a predecessor was studied. In case of alternative technologies that provided adding only by-products of the predecessor, the yield of winter wheat was 3.73 t/ha when using integrated protection system, and it was increased to 4.22 t/ha with grain quality of the 4th–5th class of the group B when foliar dressing was applied. Resource saving technologies of cultivation with restricted use of fertilizers (Р45К45N30(II+30(IV provided productivity at the level of 5.19–5.61 t/ha with grain quality of the 2nd–3rd class of the group A. Grain yield of 6.27 t/ha of the 2nd class quality was obtained by the use of intensive cultivation technology, which included application of mineral fertilizers (Р90К90N30(II+60(IV+30(VIII in addition to the use of predecessor’s by-products and foliar dressing. The highest yield of grain (6.71 t/ha on average during all years of the study with the 1st class of the group A quality was provided by energy-intensive technology, which included application of P135K135N60(II+75(IV+45(VIII with embedding of predecessor’s by-products into the soil and foliar dressing. Conclusions. It was established that in the northern part of the Forest-Steppe zone of Ukraine the highest productivity of winter wheat was obtained in dark gray podzolic soils using the energy-intensive technology with application of P135K135N60(II+75(IV+45(VIII against the background of predecessor’s by-products embedded into the soil in case of integrated plant protection, and foliar dres

  6. Mechanical weed control in organic winter wheat

    Directory of Open Access Journals (Sweden)

    Euro Pannacci

    2017-12-01

    Full Text Available Three field experiments were carried out in organic winter wheat in three consecutive years (exp. 1, 2005-06; exp. 2, 2006- 07; exp. 3, 2007-08 in central Italy (42°57’ N - 12°22’ E, 165 m a.s.l. in order to evaluate the efficacy against weeds and the effects on winter wheat of two main mechanical weed control strategies: i spring tine harrowing used at three different application times (1 passage at T1, 2 passages at the time T1, 1 passage at T1 followed by 1 passage at T1 + 14 days in the crop sowed at narrow (traditional row spacing (0.15 m; and ii split-hoeing and finger-weeder, alone and combined at T1, in the crop sowed at wider row spacing (0.30 m. At the time T1 winter wheat was at tillering and weeds were at the cotyledons-2 true leaves growth stage. The experimental design was a randomized block with four replicates. Six weeks after mechanical treatments, weed ground cover (% was rated visually using the Braun-Blanquet coverabundance scale; weeds on three squares (0.6×0.5 m each one per plot were collected, counted, weighed, dried in oven at 105°C to determine weed density and weed above-ground dry biomass. At harvest, wheat ears density, grain yield, weight of 1000 seeds and hectolitre weight were recorded. Total weed flora was quite different in the three experiments. The main weed species were: Polygonum aviculare L. (exp. 1 and 2, Fallopia convolvulus (L. Á. Löve (exp. 1 and 3, Stachys annua (L. L. (exp. 1, Anagallis arvensis L. (exp. 2, Papaver rhoeas L. (exp.3, Veronica hederifolia L. (exp. 3. In the winter wheat sowed at narrow rows, 2 passages with spring-tine harrowing at the same time seems to be the best option in order to reconcile a good efficacy with the feasibility of treatment. In wider rows spacing the best weed control was obtained by split hoeing alone or combined with finger-weeder. The grain yield, on average 10% higher in narrow rows, the lower costs and the good selectivity of spring-tine harrowing

  7. NS Pudarka: A new winter wheat cultivar

    Directory of Open Access Journals (Sweden)

    Hristov Nikola

    2014-01-01

    Full Text Available The high-yielding, medium late winter wheat cultivar NS Pudarka was developed by crossing genetic divergent parents: line NMNH-07 and cv. NS 40S and Simonida. In cultivar NS Pudarka genes responsible for high yield potential, very good technological quality, resistance to lodging, low temperature and diseases, were successfully combined. It was registered by Ministry of agriculture, forestry and water management of Serbia Republic in 2013. This cultivar has wide adaptability and stability of yield that enable growing in different environments with optimal agricultural practice. On the base of technological quality this cultivar belongs to the second quality class, A2 farinograph subgroup and second technological group.

  8. Warmed Winter Water Temperatures Alter Reproduction in Two Fish Species.

    Science.gov (United States)

    Firkus, Tyler; Rahel, Frank J; Bergman, Harold L; Cherrington, Brian D

    2018-02-01

    We examined the spawning success of Fathead Minnows (Pimephales promelas) and Johnny Darters (Etheostoma nigrum) exposed to elevated winter water temperatures typical of streams characterized by anthropogenic thermal inputs. When Fathead Minnows were exposed to temperature treatments of 12, 16, or 20 °C during the winter, spawning occurred at 16 and 20 °C but not 12 °C. Eggs were deposited over 9 weeks before winter spawning ceased. Fathead Minnows from the three winter temperature treatments were then exposed to a simulated spring transition. Spawning occurred at all three temperature treatments during the spring, but fish from the 16° and 20 °C treatment had delayed egg production indicating a latent effect of warm winter temperatures on spring spawning. mRNA analysis of the egg yolk protein vitellogenin showed elevated expression in female Fathead Minnows at 16 and 20 °C during winter spawning that decreased after winter spawning ceased, whereas Fathead Minnows at 12 °C maintained comparatively low expression during winter. Johnny Darters were exposed to 4 °C to represent winter temperatures in the absence of thermal inputs, and 12, 16, and 20 °C to represent varying degrees of winter thermal pollution. Johnny Darters spawned during winter at 12, 16, and 20 °C but not at 4 °C. Johnny Darters at 4 °C subsequently spawned following a simulated spring period while those at 12, 16, and 20 °C did not. Our results indicate elevated winter water temperatures common in effluent-dominated streams can promote out-of-season spawning and that vitellogenin expression is a useful indicator of spawning readiness for fish exposed to elevated winter temperatures.

  9. Warmed Winter Water Temperatures Alter Reproduction in Two Fish Species

    Science.gov (United States)

    Firkus, Tyler; Rahel, Frank J.; Bergman, Harold L.; Cherrington, Brian D.

    2018-02-01

    We examined the spawning success of Fathead Minnows ( Pimephales promelas) and Johnny Darters ( Etheostoma nigrum) exposed to elevated winter water temperatures typical of streams characterized by anthropogenic thermal inputs. When Fathead Minnows were exposed to temperature treatments of 12, 16, or 20 °C during the winter, spawning occurred at 16 and 20 °C but not 12 °C. Eggs were deposited over 9 weeks before winter spawning ceased. Fathead Minnows from the three winter temperature treatments were then exposed to a simulated spring transition. Spawning occurred at all three temperature treatments during the spring, but fish from the 16° and 20 °C treatment had delayed egg production indicating a latent effect of warm winter temperatures on spring spawning. mRNA analysis of the egg yolk protein vitellogenin showed elevated expression in female Fathead Minnows at 16 and 20 °C during winter spawning that decreased after winter spawning ceased, whereas Fathead Minnows at 12 °C maintained comparatively low expression during winter. Johnny Darters were exposed to 4 °C to represent winter temperatures in the absence of thermal inputs, and 12, 16, and 20 °C to represent varying degrees of winter thermal pollution. Johnny Darters spawned during winter at 12, 16, and 20 °C but not at 4 °C. Johnny Darters at 4 °C subsequently spawned following a simulated spring period while those at 12, 16, and 20 °C did not. Our results indicate elevated winter water temperatures common in effluent-dominated streams can promote out-of-season spawning and that vitellogenin expression is a useful indicator of spawning readiness for fish exposed to elevated winter temperatures.

  10. Aspen Winter Conferences on High Energy

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2011-02-12

    The 2011 Aspen Winter Conference on Particle Physics was held at the Aspen Center for Physics from February 12 to February 18, 2011. Ninety-four participants from ten countries, and several universities and national labs attended the workshop titled, "New Data From the Energy Frontier." There were 54 formal talks, and a considerable number of informal discussions held during the week. The week's events included a public lecture ("The Hunt for the Elusive Higgs Boson" given by Ben Kilminster from Ohio State University) and attended by 119 members of the public, and a physics cafe geared for high schoolers that is a discussion with physicists. The 2011 Aspen Winter Conference on Astroparticle physics held at the Aspen Center for Physics was "Indirect and Direct Detection of Dark Matter." It was held from February 6 to February 12, 2011. The 70 participants came from 7 countries and attended 53 talks over five days. Late mornings through the afternoon are reserved for informal discussions. In feedback received from participants, it is often these unplanned chats that produce the most excitement due to working through problems with fellow physicists from other institutions and countries or due to incipient collaborations. In addition, Blas Cabrera of Stanford University gave a public lecture titled "What Makes Up Dark Matter." There were 183 members of the general public in attendance. Before the lecture, 45 people attended the physics cafe to discuss dark matter. This report provides the attendee lists, programs, and announcement posters for each event.

  11. Regional greenhouse gas emissions from cultivation of winter wheat and winter rapeseed for biofuels in Denmark

    DEFF Research Database (Denmark)

    Elsgaard, Lars; Olesen, Jørgen E; Hermansen, John Erik

    2013-01-01

    by such regional factors as soil conditions, climate and input of agrochemicals. Here we analysed at a regional scale the greenhouse gas (GHG) emissions associated with cultivation of winter wheat for bioethanol and winter rapeseed for rapeseed methyl ester (RME) under Danish conditions. Emitted CO2 equivalents...... (CO2eq) were quantified from the footprints of CO2, CH4 and N2O associated with cultivation and the emissions were allocated between biofuel energy and co-products. Greenhouse gas emission at the national level (Denmark) was estimated to 22.1 g CO2eq MJ−1 ethanol for winter wheat and 26.0 g CO2eq MJ−1...... RME for winter rapeseed. Results at the regional level (level 2 according to the Nomenclature of Territorial Units for Statistics [NUTS]) ranged from 20.0 to 23.9 g CO2eq MJ−1 ethanol and from 23.5 to 27.6 g CO2eq MJ−1 RME. Thus, at the regional level emission results varied by up to 20%. Differences...

  12. Winter-APK voor bijen : Helpt u deze winter mee bij het praktijkonderzoek?

    NARCIS (Netherlands)

    Som de Cerff, B.; Cornelissen, B.; Moens, F.

    2013-01-01

    Om de risico’s van een aanrijding bij sneeuw en gladheid te verminderen, laten steeds meer automobilisten bij het monteren van winterbanden ook een wintercontrole uitvoeren. Zou een dergelijke controle voor de winter ook schade aan onze volken in de vorm van wintersterfte kunnen verminderen? Dat zou

  13. Simulation of Winter Wheat Yield with WOFOST in County Scale

    OpenAIRE

    Ma, Shangjie; Pei, Zhiyuan; He, Yajuan; Wang, Lianlin; Ma, Zhiping

    2015-01-01

    International audience; Winter wheat is mainly planted in water shortage area, such as North China and Northwest China. As a key field management measure, irrigation plays an important role in the production of winter wheat. This paper focuses on the improvement of regional winter wheat yield estimation technique in county scale by adjusting the irrigation management measure in crop growth model. The WOFOST (World Food Study) model was used by dividing the whole county into a number of EMUs (...

  14. Wintering bald eagle trends in northern Arizona, 1975-2000

    Science.gov (United States)

    Teryl G. Grubb

    2003-01-01

    Between 1975 and 2000, 4,525 sightings of wintering bald eagles (Haliaeetus leucocephalus) were recorded at Mormon Lake in northern Arizona. Numbers of wintering eagles fluctuated little in the 20 years from 1975 through 1994 (5.5 ± 3.0 mean sightings per day). However, during the winters of 1995 through 1997 local record highs of 59 to 118 eagles...

  15. Evaluation and Economic Value of Winter Weather Forecasts

    OpenAIRE

    Snyder, Derrick William

    2014-01-01

    State and local highway agencies spend millions of dollars each year to deploy winter operation teams to plow snow and de-ice roadways. Accurate and timely weather forecast information is critical for effective decision making. Students from Purdue University partnered with the Indiana Department of Transportation to create an experimental winter weather forecast service for the 2012-2013 winter season in Indiana to assist in achieving these goals. One forecast product, an hourly timeline of ...

  16. The History of Winter: teachers as scientists

    Science.gov (United States)

    Koenig, L.; Courville, Z.; Wasilewski, P. J.; Gow, T.; Bender, K. J.

    2013-12-01

    The History of Winter (HOW) is a NASA Goddard Space Flight Center-funded teacher enrichment program that was started by Dr. Peter Wasilewski (NASA), Dr. Robert Gabrys (NASA) and Dr. Tony Gow (Cold Regions Research and Engineering Laboratory, or CRREL) in 2001 and continues with support and involvement of scientists from both the NASA Cryospheric Sciences Laboratory and CREEL. The program brings educators mostly from middle and high schools but also from state parks, community colleges and other institutions from across the US to the Northwood School (a small, private boarding school) in Lake Placid, NY for one week to learn about several facets of winter, polar, and snow research, including the science and history of polar ice core research, lake ice formation and structure, snow pack science, winter ecology, and remote sensing including current and future NASA cryospheric missions. The program receives support from the Northwood School staff to facilitate the program. The goal of the program is to create 'teachers as scientists' which is achieved through several hands-on field experiences in which the teachers have the opportunity to work with polar researchers from NASA, CRREL and partner Universities to dig and sample snow pits, make ice thin sections from lake ice, make snow shelters, and observe under-ice lake ecology. The hands-on work allows the teachers to use the same tools and techniques used in polar research while simultaneously introducing science concepts and activities to support their classroom work. The ultimate goal of the program is to provide the classroom teachers with the opportunity to learn about current and timely cryospheric research as well as to engage in real fieldwork experiences. The enthusiasm generated during the week-long program is translated into classroom activities with guidance from scientists, teachers and educational professionals. The opportunity to engage with polar researchers, both young investigators and renowned

  17. Late Holocene Plankton Domain Shifts in the North Pacific Subtropical Gyre Revealed by Amino Acid Specific δ13C and δ15N Records from Proteinaceous Deep-Sea Corals

    Science.gov (United States)

    Sherwood, O.; McMahon, K.; Guilderson, T. P.; Mccarthy, M. D.

    2014-12-01

    Recent observations from station ALOHA have framed a new paradigm about the dynamic nature of subtropical ocean gyres. These vast regions are now known to vary physically and biologically, over a range of timescales, with important implications for the export of carbon to the deep ocean. In the largest of these gyres, the North Pacific subtropical gyre (NPSG), primary production has increased in recent decades despite a reduction in nutrient supply to surface waters. This is thought to be the result of a shift in plankton community structure from mostly eukaryotes to mostly dinitrogen-fixing prokaryotes. It remains uncertain, however, whether the recent plankton community domain shift can be linked to cyclical climate variability or a long-term global warming trend. To establish historical trends, we analyzed nitrogen (δ15N) and carbon (δ13C) isotopic records preserved in the skeletons of extraordinarily long-lived, proteinaceous deep-sea corals, which feed on, and therefore serve as a proxy for, exported productivity. Specimens of Hawaiian gold coral (Kulamanamana haumeaae) were collected from the Hawaiian archipelago and sampled across the skeletal growth rings to generate high-resolution (5 yr), millennial-length records of "bulk" δ15N and δ13C. After a millennium of relatively minor fluctuation, δ15N decreased by up to 2 per mil between 1850 and the present. Analysis of amino-acid-specific δ15N on a subset of the samples, combined with isotopic mass balance between nitrate and nitrogen fixation, implied a 17 to 27 % increase in nitrogen fixation as the underlying cause for the observed trends. This interpretation is supported by analysis of the δ13C of essential amino acids, which serve as isotopic fingerprints of primary producer origin. Together, these independent lines of evidence describe a domain shift from a dominantly eukaryotic to dinitrogen-fixing prokaryotic plankton community. This shift has been ongoing since the end of the Little Ice Age

  18. Home advantage in the Winter Paralympic Games 1976-2014.

    Science.gov (United States)

    Wilson, Darryl; Ramchandani, Girish

    2017-01-01

    There is a limited amount of home advantage research concerned with winter sports. There is also a distinct lack of studies that investigate home advantage in the context of para sport events. This paper addresses this gap in the knowledge by examining home advantage in the Winter Paralympic Games. Using a standardised measure of success, we compared the performances of host nations at home with their own performances away from home between 1976 and 2014. Both country level and individual sport level analysis is conducted for this time period. Comparisons are also drawn with the Winter Olympic Games since 1992, the point from which both the Winter Olympic Games and the Winter Paralympic Games have been hosted by the same nations and in the same years. Clear evidence of a home advantage effect in the Winter Paralympic Games was found at country level. When examining individual sports, only alpine skiing and cross country skiing returned a significant home advantage effect. When comparing home advantage in the Winter Paralympic Games with the Winter Olympic Games for the last seven host nations (1992-2014), we found that home advantage was generally more pronounced (although not a statistically significant difference) in the case of the former. The causes of home advantage in the Winter Paralympic Games are unclear and should be investigated further.

  19. Energy market barometer report - Winter 2016

    International Nuclear Information System (INIS)

    Schleich, Joachim; Cartel, Melodie; Shao, Evan; Vernay, Anne-Lorene

    2017-01-01

    This Winter 2016 edition of the Grenoble Ecole de Management (GEM) Energy Market Barometer explores the opinion of French energy experts about the decentralization of the electricity sector in France. French experts were also asked where the focus of French energy policy should be in the next five years. Key findings: - French energy experts sense a clear trend toward the decentralization of the French electricity system; - Technology innovation and self-sufficiency for corporations and municipalities are the two major promises of decentralization; - The major barriers to faster decentralization in France are the high price of energy storage systems and the lack of political will; - 74% of experts believe that energy efficiency should be a top priority for French energy policy in the next five years; - Reducing greenhouse gas emissions and facilitating the decentralization of the electricity sector should also be a top priority for French energy policy in the next five years; - Experts are divided over the future of nuclear energy

  20. Landsat Science Team: 2016 winter meeting summary

    Science.gov (United States)

    Schroeder, Todd; Loveland, Thomas; Wulder, Michael A.; Irons, James R.

    2016-01-01

    The winter meeting of the joint U.S. Geological Survey (USGS)–NASA Landsat Science Team (LST) was held January 12-14, 2016, at Virginia Tech University in Blacksburg, VA. LST co-chairs Tom Loveland [USGS’s Earth Resources Observation and Science Data Center (EROS)—Senior Scientist] and Jim Irons [NASA’s Goddard Space Flight Center (GSFC)—Landsat 8 Project Scientist] welcomed more than 50 participants to the three-day meeting. The main objectives of this meeting focused on identifying priorities and approaches to improve the global moderate-resolution satellite record. Overall, the meeting was geared more towards soliciting team member recommendations on several rapidly evolving issues, than on providing updates on individual research activities. All the presentations given at the meeting are available at landsat.usgs. gov//science_LST_january2016.php.

  1. Chemical profile of Taxodium distichum winter cones

    Directory of Open Access Journals (Sweden)

    Đapić Nina M.

    2017-01-01

    Full Text Available This work is concerned with the chemical profile of Taxodium distichum winter cones. The extract obtained after maceration in absolute ethanol was subjected to qualitative analysis by gas chromatography/mass spectrometry and quantification was done by gas chromatography/ flame ionization detector. The chromatogram revealed the presence of 53 compounds, of which 33 compounds were identified. The extract contained oxygenated monoterpenes (12.42%, sesquiterpenes (5.18%, oxygenated sesquiterpenes (17.41%, diterpenes (1.15%, and oxygenated diterpenes (30.87%, while the amount of retinoic acid was 0.32%. Monoacylglycerols were detected in the amount of 4.32%. The most abundant compounds were: caryophyllene oxide (14.27%, 6,7-dehydro-ferruginol (12.49%, bornyl acetate (10.96%, 6- deoxy-taxodione (9.50% and trans-caryophyllene (4.20%.

  2. On the relation between ionospheric winter anomalies and solar wind

    International Nuclear Information System (INIS)

    Rumi, G.C.

    2001-01-01

    There are two different winter anomalies. A small one that appears in connection with ionization at relatively low latitudes in the bottom of the D-region of the ionosphere. There, the electron densities in the winter happen to be less than should be expected. On the other hand, the classic winter anomaly is present when in the winter the upper D-region, again at relatively low latitudes, has more ionization than should be expected. Both these effects are due to the slant compression of the geomagnetic field produced by the solar wind in the wind in the winter season (which is, of course, the summer season when reference is made to events in the other hemisphere). It is shown that the small winter anomaly is a consequence of a hemispheric imbalance in the flux of galactic cosmic rays determined by the obliquely distorted geomagnetic field. It is shown that the standard winter anomaly can be ascribed to the influx of a super solar wind, which penetrates into the Earth's polar atmosphere down to E-region, heights and, duly concentrated through a funneling action at the winter pole of the distorted geomagnetic field, slows down the winter polar vortex. An equatorward motion of the polar air with its content of nitric oxide brings about the excess of ionization in the upper D-region at lower latitudes. The experimentally observed rhythmic recurrence of the upper winter anomaly is correlated to a possible rhythmic recurrence of the super solar wind. The actual detection of the upper winter anomaly could yield some information on the velocity of the basic solar wind. A by-product of the present analysis, the determination of Γ, the coefficient of collisional detachment of the electrons from the O 2 - ions, is presented in the Appendix

  3. CAN WINTER DEPRESSION BE PREVENTED BY LIGHT TREATMENT

    NARCIS (Netherlands)

    MEESTERS, Y; LAMBERS, PA; JANSEN, JHC; BOUHUYS, AL; BEERSMA, DGM; VANDENHOOFDAKKER, RH

    1991-01-01

    The administration of light at the development of the first signs of a winter depression appears to prevent it from developing into a full-blown depression. No patient from a group of 10 treated in this way developed any signs of depression during the rest of the winter season, while five of seven

  4. A winter severity index for the state of Maine.

    Science.gov (United States)

    2009-01-01

    Winter maintenance in the Sate of Maine consumes around twenty percent of the Bureau of : Maintenance and Operations budget each year. Costs are directly related to the length and severity : of a winter season. In addition, the cost of materials and ...

  5. Changes occurring in plain, straining and winter yoghurt during the ...

    African Journals Online (AJOL)

    In this study, winter yoghurt, straining yoghurt and yoghurt samples produced from homogenized and non-homogenized sheep and a mixture of sheep and cows milks were evaluated during the storage periods. Winter yoghurt, straining yoghurt and yoghurt samples were stored in sterile jars in the refrigerator (4°C).

  6. Can winter depression be prevented by light treatment?

    NARCIS (Netherlands)

    Meesters, Ybe; Lambers, Petrus A.; Jansen, Jacob; Bouhuys, Antoinette L.; Beersma, Domien G.M.; Hoofdakker, Rutger H. van den

    1991-01-01

    The administration of light at the development of the first signs of a winter depression appears to prevent it from developing into a full-blown depression. No patient from a group of 10 treated in this way developed any signs of depression during the rest of the winter season, while five of seven

  7. The decline in winter excess mortality in The Netherlands

    NARCIS (Netherlands)

    Kunst, A. E.; Looman, C. W.; Mackenbach, J. P.

    1991-01-01

    In most countries, numbers of deaths rise considerably during the winter season. This winter excess in mortality has, however, been declining during recent decades. The causes of this decline are hardly known. This paper attempts to derive a number of hypotheses on the basis of a detailed

  8. The elusive gene for keratolytic winter erythema | Hull | South ...

    African Journals Online (AJOL)

    Keratolytic winter erythema (KWE), also known as Oudtshoorn skin disease, is characterised by a cyclical disruption of normal epidermal keratinisation affecting primarily the palmoplantar skin with peeling of the palms and soles, which is worse in the winter. It is a rare monogenic, autosomal dominant condition of unknown ...

  9. Zimbabwean fourth social workers conference and winter school ...

    African Journals Online (AJOL)

    Such steps include running the Annual Social Workers Conference & Winter School. This annual observance creates a platform to showcase the goals and accomplishments of diverse social work professionals in the country, give a report on progress and convening a social work winter school for exchanging professional ...

  10. AGROTECHNOLOGY OF WINTER CABBAGE SEED PRODUCTION IN CONDITION OF DAGESTAN

    Directory of Open Access Journals (Sweden)

    N. M. Velizhanov

    2013-01-01

    Full Text Available Soil-climatic conditions of the South region of Dagestan are suitable for growing of winter cabbage. The yield of winter cab-bage in Dagestan farms is still very low because of low quality of seeds and non'observance of rules of cabbage seed production.

  11. Baraitser–Winter syndrome: An additional Arab patient | Henedy ...

    African Journals Online (AJOL)

    Baraitser–Winter syndrome: An additional Arab patient. MMA Henedy, MJ Marafie, SJ Abulhasan. Abstract. An Arab child is presented herein with a phenotype that fits the rare Baraitser–Winter syndrome. Her clinical features included a unilateral iris coloboma, ptosis, hypertelorism, epicanthic folds, broad nasal bridge, full ...

  12. Overhead irrigation increased winter chilling and floral bud ...

    African Journals Online (AJOL)

    Eucalyptus nitens requires a sufficiently cold winter to produce flower buds. In areas in South Africa where E. nitens commercial plantations as well as breeding and production seed orchards are located, winter chilling is often insufficient for floral bud initiation. Hence, under such conditions, E. nitens floral bud and seed ...

  13. Prevalence of hematozoa infections among breeding and wintering Rusty Blackbirds

    Science.gov (United States)

    William H. Barnard; Claudia Mettke-Hofmann; Steven M. Matsuoka

    2010-01-01

    The Rusty Blackbird (Euphagus carolinus) has declined precipitously over the past several decades,and stressors on both the breeding and wintering grounds are suspected causes. Over 3 years, we collected blood samples from breeding birds in Alaska and Maine and from wintering birds in Mississippi and Arkansas to determine the prevalence of hematozoan infections at...

  14. The phenotypic diversity and fruit characterization of winter squash ...

    African Journals Online (AJOL)

    PRECIOUS

    2010-01-11

    Jan 11, 2010 ... Winter squash are one of the most important Cucurbit crops in Turkey. Winter squash populations show great diversity in morphological characteristics, particularly fruit length, fruit diameter, fruit shape, fruit brightness, skin thickness , flesh thickness and colour in the Black Sea region of. Turkey. In this ...

  15. Changes occurring in plain, straining and winter yoghurt during the ...

    African Journals Online (AJOL)

    user

    2011-02-28

    Feb 28, 2011 ... Department of Food Engineering, Faculty of Agriculture, Yuzuncu Yil University, 65080 Van, Turkey. Accepted 18 January ... cow milk for production of winter yoghurt, which is one of the most liked traditional .... Changes occurring in winter yoghurt samples during the storage periods. Impact factor. Factor.

  16. Controls on winter ecosystem respiration in temperate and boreal ecosystems

    Science.gov (United States)

    T. Wang; P. Ciais; S.L. Piao; C. Ottle; P. Brender; F. Maignan; A. Arain; A. Cescatti; D. Gianelle; C. Gough; L Gu; P. Lafleur; T. Laurila; B. Marcolla; H. Margolis; L. Montagnani; E. Moors; N. Saigusa; T. Vesala; G. Wohlfahrt; C. Koven; A. Black; E. Dellwik; A. Don; D. Hollinger; A. Knohl; R. Monson; J. Munger; A. Suyker; A. Varlagin; S. Verma

    2011-01-01

    Winter CO2 fluxes represent an important component of the annual carbon budget in northern ecosystems. Understanding winter respiration processes and their responses to climate change is also central to our ability to assess terrestrial carbon cycle and climate feedbacks in the future. However, the factors influencing the spatial and temporal...

  17. Comparing effects of Winter Universiade (2011) and European ...

    African Journals Online (AJOL)

    ... both positive and negative effects of these two events have high averages. In other words, positive and negative effects were detected in both the Winter Universiade held in Erzurum and the European Youth Olympic Festival held in Trabzon. Key words: Mega sport events; Local spectator impressions; Winter Universiade; ...

  18. Controls on winter ecosystem respiration in temperate and boreal ecosystems

    NARCIS (Netherlands)

    Ciais, P.; Wang, T.; Piao, S.L.; Ottlé, C.; Brender, P.; Moors, E.J.

    2011-01-01

    Winter CO2 fluxes represent an important component of the annual carbon budget in northern ecosystems. Understanding winter respiration processes and their responses to climate change is also central to our ability to assess terrestrial carbon cycle and climate feedbacks in the future. However, the

  19. Downtown People Mover (DPM) Winterization Test Demonstration : Otis Elevator

    Science.gov (United States)

    1982-01-01

    The Otis Elevator Company Transportation Technology Division (OTIS-TTD) Downtown People Mover (DPM) Winterization Test Demonstration Final Report covers the 1978-79 and 1979-80 winter periods. Tests were performed at the Otis test track in Denver, Co...

  20. Weed seed germination in winter cereals under contrasting tillage systems

    DEFF Research Database (Denmark)

    Scherner, Ananda

    2015-01-01

    Grass weeds and Gallium aparine are major weed problems in North European arable cropping systems with high proportions of winter crops, especially winter wheat (Clarke et al., 2000; Melander et al., 2008). Problems are accentuated where inverting tillage is omitted, as weed seeds tend to accumul...

  1. Identifying the potential wintering sites of the globally threatened ...

    African Journals Online (AJOL)

    The Aquatic Warbler is a threatened Afro-Palaearctic migrant with a largely unknown distribution in the winter (non-breeding) season. Protection of wintering sites may be crucial for the conservation of the species. Previous studies have identified extensive areas of north-western sub-Saharan Africa that could potentially be ...

  2. 32th Winter Workshop on Nuclear Dynamics

    CERN Document Server

    2016-01-01

    The 32nd edition of the Winter Workshop will be held 28 February - 5 March 2016, Hotel Resort Fort Royal Guadeloupe in Guadeloupe a French overseas territory, is an island group in the southern Caribbean Sea. As with previous years, the workshop will bring together scientists from all fields of nuclear physics for engaging and friendly exchanges of ideas. Much emphasis will be on the recent LHC, RHIC and SPS heavy ion results, but advances in the ongoing and future programs at FAIR, FRIB, EIC, JLab and NICA and will also be featured. The meeting will start with a welcome reception on the evening of Sunday, February 28. The workshop program will commence on Monday morning and run until Saturday. We recommend to arrive on Sunday and leave on Sunday. Talks will be as usual 25+5 minutes, there will be no parallel sessions. If you are interested in presenting your work, please fill out the registration form prior to the registration deadline. After the program committee has met we will confirm your talk via indivi...

  3. Geophysical forecast: industry expects busy winter season

    Energy Technology Data Exchange (ETDEWEB)

    Ludwick, J.

    1997-11-01

    Survey results by the Canadian Association of Geophysical Contractors were discussed. According to the survey, all of the sector`s 65 crews will be fully utilized this winter, although no activity records are expected. Charges are likely to be slightly higher than last year. At least some of the increase will go towards increased pay to attract more workers into the field in an effort to counter the labour shortage in the seismic industry. Contractors must compete with other sectors such as construction, which is booming as a result of Alberta`s burgeoning economy. The Slave Lake and Rocky Mountain House regions are expected to be the hottest in Alberta. Southeastern Saskatchewan also promises to be the site of increased activity due to the growing interest in the Red River oil play. Another reason for the increased activity may be the use of innovative technology such as that employed by Enertec Geophysical Service Limited. It will pilot-test its newly acquired PowerProbe technology, which is said to be able to immediately detect the presence of hydrocarbons.

  4. Comparison of East Asian winter monsoon indices

    Directory of Open Access Journals (Sweden)

    Gao Hui

    2007-01-01

    Full Text Available Four East Asian winter monsoon (EAWM indices are compared in this paper. In the research periods, all the indices show similar interannual and decadal-interdecadal variations, with predominant periods centering in 3–4 years, 6.5 years and 9–15 years, respectively. Besides, all the indices show remarkable weakening trends since the 1980s. The correlation coefficient of each two indices is positive with a significance level of 99%. Both the correlation analyses and the composites indicate that in stronger EAWM years, the Siberian high and the higher-level subtropical westerly jet are stronger, and the Aleutian low and the East Asia trough are deeper. This circulation pattern is favorable for much stronger northwesterly wind and lower air temperature in the subtropical regions of East Asia, while it is on the opposite in weaker EAWM years. Besides, EAWM can also exert a remarkable leading effect on the summer monsoon. After stronger (weaker EAWM, less (more summer precipitation is seen over the regions from the Yangtze River valley of China to southern Japan, while more (less from South China Sea to the tropical western Pacific.

  5. Report 3 energy market barometer - Winter 2014

    International Nuclear Information System (INIS)

    Schleich, Joachim; Cateura, Olivier; Faure, Corinne; Jacob, Jojo; Javaudin, Laurent; Molecke, Greg; Olsthoorn, Mark; Pinkse, Jonatan; Shomali, Azadeh; Vernay, Anne-Lorene

    2015-01-01

    This Winter 2014 edition of the Grenoble Ecole de Management (GEM) Energy Market Barometer documents the French energy experts' estimates of the future electricity mix in France and in the European Union, their assessment of the regulatory conditions in France for investments in energy technologies, and their expectations about the development of energy and CO 2 -certificate prices. Key findings: - Fewer than one in four experts believes that the target to decrease nuclear power's share of the French power mix to 50% by 2025 will be met; - The share of renewable energy sources (other than hydropower) in the French power mix is expected to almost quadruple by 2030; - Renewable energy sources (other than hydropower) are believed to become the dominating source of electricity in the EU in 2030; - About two thirds of the experts think that current regulatory conditions in France are particularly accommodating for investments in energy efficiency and renewable energies; - Experts are divided over how supportive current and future regulatory conditions are for encouraging investments in nuclear power in France; - Electricity prices are expected to remain stable over the next six months but to increase over the next 5 years; - Oil prices are expected to continue to decrease over the next six month, but increase over the next 5 years; - CO 2 certificate prices are expected to rise only in the medium to longer term but levels remain rather low

  6. Novel psychrotolerant picocyanobacteria isolated from Chesapeake Bay in the winter.

    Science.gov (United States)

    Xu, Yongle; Jiao, Nianzhi; Chen, Feng

    2015-08-01

    Picocyanobacteria are major primary producers in the ocean, especially in the tropical or subtropical oceans or during warm seasons. Many "warm" picocyanobacterial species have been isolated and characterized. However, picocyanobacteria in cold environments or cold seasons are much less studied. In general, little is known about the taxonomy and ecophysiology of picocyanobacteria living in the winter. In this study, 17 strains of picocyanobacteria were isolated from Chesapeake Bay, a temperate estuarine ecosystem, during the winter months. These winter isolates belong to five distinct phylogenetic lineages, and are distinct from the picocyanobacteria previously isolated from the warm seasons. The vast majority of the winter isolates were closely related to picocyanobacteria isolated from other cold environments like Arctic or subalpine waters. The winter picocyanobacterial isolates were able to maintain slow growth or prolonged dormancy at 4°C. Interestingly, the phycoerythrin-rich strains outperformed the phycocyanin-rich strains at cold temperature. In addition, winter picocyanobacteria changed their morphology when cultivated at 4°C. The close phylogenetic relationship between the winter picocyanobacteria and the picocyanobacteria living in high latitude cold regions indicates that low temperature locations select specific ecotypes of picocyanobacteria. © 2015 Phycological Society of America.

  7. Relationship of deer and moose populations to previous winters' snow

    Science.gov (United States)

    Mech, L.D.; McRoberts, R.E.; Peterson, R.O.; Page, R.E.

    1987-01-01

    (1) Linear regression was used to relate snow accumulation during single and consecutive winters with white-tailed deer (Odocoileus virginianus) fawn:doe ratios, mosse (Alces alces) twinning rates and calf:cow ratios, and annual changes in deer and moose populations. Significant relationships were found between snow accumulation during individual winters and these dependent variables during the following year. However, the strongest relationships were between the dependent variables and the sums of the snow accumulations over the previous three winters. The percentage of the variability explained was 36 to 51. (2) Significant relationships were also found between winter vulnerability of moose calves and the sum of the snow accumulations in the current, and up to seven previous, winters, with about 49% of the variability explained. (3) No relationship was found between wolf numbers and the above dependent variables. (4) These relationships imply that winter influences on maternal nutrition can accumulate for several years and that this cumulative effect strongly determines fecundity and/or calf and fawn survivability. Although wolf (Canis lupus L.) predation is the main direct mortality agent on fawns and calves, wolf density itself appears to be secondary to winter weather in influencing the deer and moose populations.

  8. Autumn Weather and Winter Increase in Cerebrovascular Disease Mortality

    LENUS (Irish Health Repository)

    McDonagh, R

    2016-11-01

    Mortality from cerebrovascular disease increases in winter but the cause is unclear. Ireland’s oceanic climate means that it infrequently experiences extremes of weather. We examined how weather patterns relate to stroke mortality in Ireland. Seasonal data for Sunshine (% of average), Rainfall (% of average) and Temperature (degrees Celsius above average) were collected for autumn (September-November) and winter (December-February) using official Irish Meteorological Office data. National cerebrovascular mortality data was obtained from Quarterly Vital Statistics. Excess winter deaths were calculated by subtracting (nadir) 3rd quarter mortality data from subsequent 1st quarter data. Data for 12 years were analysed, 2002-2014. Mean winter mortality excess was 24.7%. Winter mortality correlated with temperature (r=.60, p=0.04). Rise in winter mortality correlated strongly with the weather in the preceding autumn (Rainfall: r=-0.19 p=0.53, Temperature: r=-0.60, p=0.03, Sunshine, r=0.58, p=0.04). Winter cerebrovascular disease mortality appears higher following cool, sunny autum

  9. Sage-grouse habitat selection during winter in Alberta

    Science.gov (United States)

    Carpenter, Jennifer L.; Aldridge, Cameron L.; Boyce, Mark S.

    2010-01-01

    Greater sage-grouse (Centrocercus urophasianus) are dependent on sagebrush (Artemisia spp.) for food and shelter during winter, yet few studies have assessed winter habitat selection, particularly at scales applicable to conservation planning. Small changes to availability of winter habitats have caused drastic reductions in some sage-grouse populations. We modeled winter habitat selection by sage-grouse in Alberta, Canada, by using a resource selection function. Our purpose was to 1) generate a robust winter habitat-selection model for Alberta sage-grouse; 2) spatially depict habitat suitability in a Geographic Information System to identify areas with a high probability of selection and thus, conservation importance; and 3) assess the relative influence of human development, including oil and gas wells, in landscape models of winter habitat selection. Terrain and vegetation characteristics, sagebrush cover, anthropogenic landscape features, and energy development were important in top Akaike's Information Criterionselected models. During winter, sage-grouse selected dense sagebrush cover and homogenous less rugged areas, and avoided energy development and 2-track truck trails. Sage-grouse avoidance of energy development highlights the need for comprehensive management strategies that maintain suitable habitats across all seasons. ?? 2010 The Wildlife Society.

  10. Winter season mortality: will climate warming bring benefits?

    Science.gov (United States)

    Kinney, Patrick L.; Schwartz, Joel; Pascal, Mathilde; Petkova, Elisaveta; Le Tertre, Alain; Medina, Sylvia; Vautard, Robert

    2015-06-01

    Extreme heat events are associated with spikes in mortality, yet death rates are on average highest during the coldest months of the year. Under the assumption that most winter excess mortality is due to cold temperature, many previous studies have concluded that winter mortality will substantially decline in a warming climate. We analyzed whether and to what extent cold temperatures are associated with excess winter mortality across multiple cities and over multiple years within individual cities, using daily temperature and mortality data from 36 US cities (1985-2006) and 3 French cities (1971-2007). Comparing across cities, we found that excess winter mortality did not depend on seasonal temperature range, and was no lower in warmer vs. colder cities, suggesting that temperature is not a key driver of winter excess mortality. Using regression models within monthly strata, we found that variability in daily mortality within cities was not strongly influenced by winter temperature. Finally we found that inadequate control for seasonality in analyses of the effects of cold temperatures led to spuriously large assumed cold effects, and erroneous attribution of winter mortality to cold temperatures. Our findings suggest that reductions in cold-related mortality under warming climate may be much smaller than some have assumed. This should be of interest to researchers and policy makers concerned with projecting future health effects of climate change and developing relevant adaptation strategies.

  11. Wintering Golden Eagles on the coastal plain of South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Vukovich, Mark [USDA Forest Service-Savannah River, New Ellenton, SC (United States); Turner, Kelsey L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River Ecology Lab. (SREL); Univ. of Georgia, Aiken, SC (United States); Grazia, Tracy E. [USDA Forest Service, New Ellenton, SC (United States). Savannah River; Mims, Thiomas [USDA Forest Service, New Ellenton, SC (United States). Savannah River; Beasley, James C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River Ecology Lab. (SREL); Univ. of Georgia, Aiken, SC (United States); Kilgo, John C. [USDA Forest Service-Savannah River, New Ellenton, SC (United States)

    2015-10-01

    Golden Eagles (Aquila chrysaetos) are rare winter residents in eastern North America, with most found along the Appalachian Mountains and few reported on the coastal plain of the Carolinas. We used remote cameras baited with wild pig (Sus scrofa) and white-tailed deer (Odocoileus virginianus) carcasses to detect, age, and individually identify Golden Eagles on the U.S. Department of Energy’s Savannah River Site on the coastal plain of South Carolina. We identified eight individual Golden Eagles during the winters of 2013–2014 and 2014–2015, with one detected during both winters. We detected eagles for 19 and 66 calendar days during the winters of 2013–2014 and 2014–2015, respectively, with two adult eagles detected for 30 and 31 calendar days in 2014–2015. Eagles typically scavenged on carcasses for a few days, left, and then returned when cameras were baited with another carcass, suggesting they had remained in the area. These observations suggest that large tracts of forests on the coastal plain may be important wintering areas for some Golden Eagles and, further, that other areas in the coastal plain of the southeastern United States may also harbor wintering eagles. Identification of wintering areas of Golden Eagles in the east will be an important step in the conservation of this protected species, and camera traps baited with carcasses can be an effective tool for such work.

  12. Regional greenhouse gas emissions from cultivation of winter wheat and winter rapeseed for biofuels in Denmark

    Energy Technology Data Exchange (ETDEWEB)

    Elsgaard, Lars; Olesen, Joergen E.; Hermansen, John E.; Kristensen, Inge T.; Boergesen, Christen D. [Dept. of Agroecology, Aarhus Univ., Tjele (Denmark)], E-mail: lars.elsgaard@agrsci.dk

    2013-04-15

    Biofuels from bioenergy crops may substitute a significant part of fossil fuels in the transport sector where, e.g., the European Union has set a target of using 10% renewable energy by 2020. Savings of greenhouse gas emissions by biofuels vary according to cropping systems and are influenced by such regional factors as soil conditions, climate and input of agrochemicals. Here we analysed at a regional scale the greenhouse gas (GHG) emissions associated with cultivation of winter wheat for bioethanol and winter rapeseed for rapeseed methyl ester (RME) under Danish conditions. Emitted CO{sub 2} equivalents (CO{sub 2}eq) were quantified from the footprints of CO{sub 2}, CH{sub 4} and N{sub 2}O associated with cultivation and the emissions were allocated between biofuel energy and co-products. Greenhouse gas emission at the national level (Denmark) was estimated to 22.1 g CO{sub 2}eq MJ{sup 1} ethanol for winter wheat and 26.0 g CO{sub 2}eq MJ{sup 1} RME for winter rapeseed. Results at the regional level (level 2 according to the Nomenclature of Territorial Units for Statistics [NUTS]) ranged from 20.0 to 23.9 g CO{sub 2}eq MJ{sup 1} ethanol and from 23.5 to 27.6 g CO{sub 2}eq MJ{sup 1} RME. Thus, at the regional level emission results varied by up to 20%. Differences in area-based emissions were only 4% reflecting the importance of regional variation in yields for the emission result. Fertilizer nitrogen production and direct emissions of soil N{sub 2}O were major contributors to the final emission result and sensitivity analyses showed that the emission result depended to a large extent on the uncertainty ranges assumed for soil N{sub 2}O emissions. Improvement of greenhouse gas balances could be pursued, e.g., by growing dedicated varieties for energy purposes. However, in a wider perspective, land-use change of native ecosystems to bioenergy cropping systems could compromise the CO{sub 2} savings of bioenergy production and challenge the targets set for biofuel

  13. Winter chilling speeds spring development of temperate butterflies.

    Science.gov (United States)

    Stålhandske, Sandra; Gotthard, Karl; Leimar, Olof

    2017-07-01

    Understanding and predicting phenology has become more important with ongoing climate change and has brought about great research efforts in the recent decades. The majority of studies examining spring phenology of insects have focussed on the effects of spring temperatures alone. Here we use citizen-collected observation data to show that winter cold duration, in addition to spring temperature, can affect the spring emergence of butterflies. Using spatial mixed models, we disentangle the effects of climate variables and reveal impacts of both spring and winter conditions for five butterfly species that overwinter as pupae across the UK, with data from 1976 to 2013 and one butterfly species in Sweden, with data from 2001 to 2013. Warmer springs lead to earlier emergence in all species and milder winters lead to statistically significant delays in three of the five investigated species. We also find that the delaying effect of winter warmth has become more pronounced in the last decade, during which time winter durations have become shorter. For one of the studied species, Anthocharis cardamines (orange tip butterfly), we also make use of parameters determined from previous experiments on pupal development to model the spring phenology. Using daily temperatures in the UK and Sweden, we show that recent variation in spring temperature corresponds to 10-15 day changes in emergence time over UK and Sweden, whereas variation in winter duration corresponds to 20 days variation in the south of the UK versus only 3 days in the south of Sweden. In summary, we show that short winters delay phenology. The effect is most prominent in areas with particularly mild winters, emphasising the importance of winter for the response of ectothermic animals to climate change. With climate change, these effects may become even stronger and apply also at higher latitudes. © 2017 The Authors. Journal of Animal Ecology © 2017 British Ecological Society.

  14. Quantifying Subsidence in the 1999-2000 Arctic Winter Vortex

    Science.gov (United States)

    Greenblatt, Jeffery B.; Jost, Hans-juerg; Loewenstein, Max; Podolske, James R.; Bui, T. Paul; Elkins, James W.; Moore, Fred L.; Ray, Eric A.; Sen, Bhaswar; Margitan, James J.; hide

    2000-01-01

    Quantifying the subsidence of the polar winter stratospheric vortex is essential to the analysis of ozone depletion, as chemical destruction often occurs against a large, altitude-dependent background ozone concentration. Using N2O measurements made during SOLVE on a variety of platforms (ER-2, in-situ balloon and remote balloon), the 1999-2000 Arctic winter subsidence is determined from N2O-potential temperature correlations along several N2O isopleths. The subsidence rates are compared to those determined in other winters, and comparison is also made with results from the SLIMCAT stratospheric chemical transport model.

  15. Notes on winter feeding behavior and molt in Wilson's phalaropes

    Science.gov (United States)

    Burger, J.; Howe, M.

    1975-01-01

    Wilson's Phalaropes, Steganopus tricolor, migrate in late summer from the prairie regions of North America to their wintering grounds in the highlands of Peru and the inland and coastal waters of Chile, Bolivia, Paraguay, Uruguay, and Argentina (Holmes 1939, Meyer de Schauensee 1970). Reports on these birds from their wintering habitat are few. This paper describes numbers, feeding behavior, and molt of Wilson's Phalaropes wintering in a freshwater marsh in central Argentina. Fieldwork in Argentina was conducted by the senior author. The junior author analyzed molt patterns of birds collected there and added data he collected in North Dakota in 1968 and 1969.

  16. Urban emissions of water vapor in winter

    Science.gov (United States)

    Salmon, Olivia E.; Shepson, Paul B.; Ren, Xinrong; Marquardt Collow, Allison B.; Miller, Mark A.; Carlton, Annmarie G.; Cambaliza, Maria O. L.; Heimburger, Alexie; Morgan, Kristan L.; Fuentes, Jose D.; Stirm, Brian H.; Grundman, Robert; Dickerson, Russell R.

    2017-09-01

    Elevated water vapor (H2Ov) mole fractions were occasionally observed downwind of Indianapolis, IN, and the Washington, D.C.-Baltimore, MD, area during airborne mass balance experiments conducted during winter months between 2012 and 2015. On days when an urban H2Ov excess signal was observed, H2Ov emission estimates range between 1.6 × 104 and 1.7 × 105 kg s-1 and account for up to 8.4% of the total (background + urban excess) advected flow of atmospheric boundary layer H2Ov from the urban study sites. Estimates of H2Ov emissions from combustion sources and electricity generation facility cooling towers are 1-2 orders of magnitude smaller than the urban H2Ov emission rates estimated from observations. Instances of urban H2Ov enhancement could be a result of differences in snowmelt and evaporation rates within the urban area, due in part to larger wintertime anthropogenic heat flux and land cover differences, relative to surrounding rural areas. More study is needed to understand why the urban H2Ov excess signal is observed on some days, and not others. Radiative transfer modeling indicates that the observed urban enhancements in H2Ov and other greenhouse gas mole fractions contribute only 0.1°C d-1 to the urban heat island at the surface. This integrated warming through the boundary layer is offset by longwave cooling by H2Ov at the top of the boundary layer. While the radiative impacts of urban H2Ov emissions do not meaningfully influence urban heat island intensity, urban H2Ov emissions may have the potential to alter downwind aerosol and cloud properties.

  17. Energy market barometer report - Winter 2015

    International Nuclear Information System (INIS)

    Schleich, Joachim; Cartel, Melodie; Javaudin, Laurent; Molecke, Greg; Olsthoorn, Mark; Vernay, Anne-Lorene

    2016-01-01

    This Winter 2015 edition of the Grenoble Ecole de Management (GEM) Energy Market Barometer gauged the expectations of French energy experts regarding the low oil price and its consequences on alternative energy technologies. The experts were also asked about the investment climate for energy technologies in France. Key findings: - The energy experts consider the current low oil price a temporary phenomenon. The price of a barrel of crude oil (Brent) to reach US$ 55 at the end of the year (2016). About three quarters of respondents expect the price of oil to increase in 5 years and to exceed US$ 100 per barrel within 10 years. - The current weak price of crude oil is thought to have an adverse impact on the amount of investment in renewables for heat generation, in biofuels, and in energy efficiency technologies. - The experts view the current regulatory environment in France for investments in renewables, e-mobility, smart grids and energy efficiency favorably. They expect it to continue to improve over the next 5 years. However, nuclear energy and natural gas will not see their investment climate improved. - The recent developments on the global and national political stage have not moved most energy and CO 2 price expectations. The experts chart a progressive yet under-whelming raise in the price of CO 2 certificates in the medium to long term, from currently 8.5 euro/ton to euro 10-15 euro/ton in 5 years and 20-25 euro/ton in 10 years. - Prices of electricity, oil and natural gas are expected to rise in the medium term but remain stable over the next six months temporary phenomenon. Coal is the only energy carrier for which experts expect a decrease in price over the next five years

  18. Real-time weed detection, decision making and patch spraying in maize, sugarbeet, winter wheat and winter barley

    DEFF Research Database (Denmark)

    Gerhards, R; Christensen, Svend

    2003-01-01

    with weed infestation levels higher than the economic weed threshold; a review of such work is provided. This paper presents a system for site-specific weed control in sugarbeet (Beta vulgaris L.), maize (Zea mays L.), winter wheat (Triticum aestivum L.) and winter barley (Hordeum vulgare L.), including...... online weed detection using digital image analysis, computer-based decision making and global positioning systems (GPS)-controlled patch spraying. In a 4-year study, herbicide use with this map-based approach was reduced in winter cereals by 60% for herbicides against broad-leaved weeds and 90% for grass...

  19. NEFSC 2001 Winter Bottom Trawl Survey (AL0102, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The objectives of the cruise are to: (1) determine the winter distribution and relative abundance of fish and selected invertebrate species; (2) collect biological...

  20. NEFSC 2000 Winter Bottom Trawl Survey (AL0001, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The objectives of the cruise are to: (1) determine the winter distribution and relative abundance of fish and selected invertebrate species; (2) collect biological...

  1. Comparison of winter temperature profiles in asphalt and concrete pavements.

    Science.gov (United States)

    2014-06-01

    The objectives of this research were to 1) determine which pavement type, asphalt or concrete, has : higher surface temperatures in winter and 2) compare the subsurface temperatures under asphalt and : concrete pavements to determine the pavement typ...

  2. JTEL Winter School for Advanced Technologically Enhanced Learning

    NARCIS (Netherlands)

    Glahn, Christian; Gruber, Marion

    2010-01-01

    Glahn, C., & Gruber, M. (2010). JTEL Winter School for Advanced Technologically Enhanced Learning. In ~mail. Das Magazin des Tiroler Bildungsinstituts, 01/10, März (p. 3-4). Innsbruck: Grillhof, Medienzentrum.

  3. Prediction of thermal behavior of pervious concrete pavements in winter.

    Science.gov (United States)

    2017-05-15

    Because application of pervious concrete pavement (PCPs) has extended to cold-climate regions of the United States, the safety and : mobility of PCP installations during the winter season need to be maintained. Timely application of salt, anti-icing,...

  4. zimbabwean fourth social workers conference and winter school

    African Journals Online (AJOL)

    cswserver

    commercial 4.0 International License. ZIMBABWEAN FOURTH SOCIAL WORKERS CONFERENCE AND WINTER. SCHOOL. Noah Mudenda. The Council of Social Workers (CSW or Council) was established under the Social Workers Act 27:21 ...

  5. Reindeer (Rangifer tarandus and climate change: Importance of winter forage

    Directory of Open Access Journals (Sweden)

    Thrine Moen Heggberget

    2002-06-01

    Full Text Available As a consequence of increasing greenhouse gas concentrations, climate change is predicted to be particularly pronounced, although regionally variable, in the vast arctic, sub-arctic and alpine tundra areas of the northern hemisphere. Here, we review winter foraging conditions for reindeer and caribou (Rangifer tarandus living in these areas, and consider diet, forage quality and distribution, accessibility due to snow variation, and effects of snow condition on reindeer and caribou populations. Finally, we hypothesise how global warming may affect wild mountain reindeer herds in South Norway. Energy-rich lichens often dominate reindeer and caribou diets. The animals also prefer lichens, and their productivity has been shown to be higher on lichen-rich than on lichen-poor ranges. Nevertheless, this energy source appears to be neither sufficient as winter diet for reindeer or caribou (at least for pregnant females nor necessary. Some reindeer and caribou populations seem to be better adapted to a non-lichen winter diet, e.g. by a larger alimentary tract. Shrubs appear to be the most common alternative winter forage, while some grasses appear to represent a good, nutritionally-balanced winter diet. Reindeer/caribou make good use of a wide variety of plants in winter, including dead and dry parts that are digested more than expected based on their fibre content. The diversity of winter forage is probably important for the mineral content of the diet. A lichen-dominated winter diet may be deficient in essential dietary elements, e.g. minerals. Sodium in particular may be marginal in inland winter ranges. Our review indicates that most Rangifer populations with lichen-dominated winter diets are either periodically or continuously heavily harvested by humans or predators. However, when population size is mainly limited by food, accessible lichen resources are often depleted. Plant studies simulating climatic change indicate that a warmer, wetter

  6. NEFSC 1999 Winter Bottom Trawl Survey (AL9902, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The objectives of the cruise are to: (1) determine the winter distribution and relative abundance of fish and selected invertebrate species; (2) collect biological...

  7. Nearshore hydrography off Visakhapatnam, East coast of India, during winter

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, B.P.; RameshBabu, V.

    Based on hydrographic data and time series data of currents and temperature, the nearshore hydrographic structure during winter (November, 1981) has been studied to examine the possibility of discharging industrial effluents into the nearby sea...

  8. Research on best practices for winter weather operations.

    Science.gov (United States)

    2012-10-01

    There is a growing need to identify actionable practices relative to winter weather operations. Because of the : potential and inherent hazards during cold weather, it has become increasingly important to ensure that these : practices can be effectiv...

  9. Nitrogen uptake in the northeastern Arabian Sea during winter cooling

    Digital Repository Service at National Institute of Oceanography (India)

    Kumar, S.; Ramesh, R.; Dwivedi, R.M.; Raman, M.; Sheshshayee, M.S.; DeSouza, W.

    technique are presented. In this relatively underexplored region, productivity is high during winter due to supply of nutrients by convective mixing caused by the cooling of the surface by the northeast monsoon winds. Studies done during different months...

  10. Characteristic features of winter precipitation and its variability over ...

    Indian Academy of Sciences (India)

    Keywords. Northwest India; winter precipitation; western disturbances; rabi crops; precipitation variability; precipitation epochs. ... The precipitation is mainly associated with the sequence of synoptic systems known as 'western disturbances'. The precipitation has ... National Atmospheric Research Laboratory, Tirupati, India.

  11. Parameters of apple tree variety resistant to winter unfavorable conditions

    OpenAIRE

    Krasova, N.

    2013-01-01

    Uncontrolled factors of the environment significantly reduce apple yielding power. Tree winter resistance is considered to be one of the basic indexes of adaptation. Certain resistant apple varieties have been revealed. The problem of manifestation of the mechanism of the resistance to winter unfavorable conditions is considered in this paper. A positive tendency has been revealed at the relationship between the contents of saccharose, proline, anthocyans, cyanidines and proteins in one-year ...

  12. Are cold winters in Europe associated with low solar activity?

    International Nuclear Information System (INIS)

    Lockwood, M; Harrison, R G; Woollings, T; Solanki, S K

    2010-01-01

    Solar activity during the current sunspot minimum has fallen to levels unknown since the start of the 20th century. The Maunder minimum (about 1650-1700) was a prolonged episode of low solar activity which coincided with more severe winters in the United Kingdom and continental Europe. Motivated by recent relatively cold winters in the UK, we investigate the possible connection with solar activity. We identify regionally anomalous cold winters by detrending the Central England temperature (CET) record using reconstructions of the northern hemisphere mean temperature. We show that cold winter excursions from the hemispheric trend occur more commonly in the UK during low solar activity, consistent with the solar influence on the occurrence of persistent blocking events in the eastern Atlantic. We stress that this is a regional and seasonal effect relating to European winters and not a global effect. Average solar activity has declined rapidly since 1985 and cosmogenic isotopes suggest an 8% chance of a return to Maunder minimum conditions within the next 50 years (Lockwood 2010 Proc. R. Soc. A 466 303-29): the results presented here indicate that, despite hemispheric warming, the UK and Europe could experience more cold winters than during recent decades.

  13. Polar vortex evolution during Northern Hemispheric winter 2004/05

    Directory of Open Access Journals (Sweden)

    T. Chshyolkova

    2007-06-01

    Full Text Available As a part of the project "Atmospheric Wave Influences upon the Winter Polar Vortices (0–100 km" of the CAWSES program, data from meteor and Medium Frequency radars at 12 locations and MetO (UK Meteorological Office global assimilated fields have been analyzed for the first campaign during the Northern Hemispheric winter of 2004/05. The stratospheric state has been described using the conventional zonal mean parameters as well as Q-diagnostic, which allows consideration of the longitudinal variability. The stratosphere was cold during winter of 2004/05, and the polar vortex was relatively strong during most of the winter with relatively weak disturbances occurring at the end of December and the end of January. For this winter the strongest deformation with the splitting of the polar vortex in the lower stratosphere was observed at the end of February. Here the results show strong latitudinal and longitudinal differences that are evident in the stratospheric and mesospheric data sets at different stations. Eastward winds are weaker and oscillations with planetary wave periods have smaller amplitudes at more poleward stations. Accordingly, the occurrence, time and magnitude of the observed reversal of the zonal mesospheric winds associated with stratospheric disturbances depend on the local stratospheric conditions. In general, compared to previous years, the winter of 2004/05 could be characterized by weak planetary wave activity at stratospheric and mesospheric heights.

  14. WATER NEEDS FOR WINTER BEAN CROP

    Directory of Open Access Journals (Sweden)

    A.E. Klar

    1997-09-01

    Full Text Available A study of water use by bean winter crop (Phaseolus vulgaris, L., cv. Carioca was carried out in a Red Yellow Latosol, clay texture. A furrow irrigation system maintained soil water potentials higher than -40 KPa. Two broadcast nitrogen treatments (0 and 30 kg N/ha were applied 25 days after planting. The major objectives were to study the nitrogen and evapotranspiration interaction and measure the crop coefficients (Kc. The maximum average evapotranspiration (ETm was 1.71 mm/day, or 157.16 mm over 92 days of observations; the ETm values for the vegetative (1, flowering (2 and pod formation (3 phases were 1.48, 2.35, and 1.50 mm/day, respectively, for the 30 kg/ha nitrogen treatment, and 1.48, 1.88 and 1.45 mm/day for the no nitrogen treatment. The crop coefficients (Kc = ETm / ETo were 0.62 and 0.78 for the phase 1, 0.80 and 1.10 for the phase 2, 0.45 and 0.55 for the phase 3 and 0.61 and 0.80 for the entire cycle, based on the FAO-Penman and Class A Pan reference methods (ETo, respectively. The latter one was the best approach to estimate maximum water use by winter bean crop. Nitrogen treatments did not affect evapotranspiration significantly. However, the measured evapotranspiration obtained from the water balance method was 59.78 and 27.12% higher in the flowering than in the vegetative phase, respectively, under 30 and 0 kg N/ha.Um estudo sobre o uso de água do feijoeiro de inverno (Phaseolus vulgaris L. cv. Carioca foi realizado num solo Latossol Vermelho Amarelo de textura argilosa. Um sistema de sulcos de infiltração foi usado para proceder a irrigação com o intuito de manter o solo em potenciais de água superiores a -40,0 KPa. Duas doses de aplicação de N em cobertura (0 a 30 Kg N/ha foram colocados 25 dias após o plantio. Os principais objetivos do estudo foram: avaliar a interação entre as duas doses de N com a evapotranspiração e medir os coeficientes de cultura (Kc. A evapotranspiração média máxima (ETm foi 1,71 mm

  15. SERSO: Summer sun against winter ice; SERSO: Mit Sommer-Sonne gegen Winter-Glatteis

    Energy Technology Data Exchange (ETDEWEB)

    Eugster, W.J. [Polydynamics Engineering, Zuerich (Switzerland); Hess, K. [Polydynamics Engineering, Bremgarten-Bern (Switzerland); Hopkirk, R.J. [Polydynamics Engineering, Maennedorf (Switzerland)

    1997-12-01

    Road surfaces absorb energy from the incoming solar radiation in the summer months. The SERSO project was conceived to collect this energy, store it and reuse it during the following winter period to eliminate ice formation on those same road surfaces. The acronym SERSO (Sonnenenergierueckgewinnung aus Strassenoberflaechen) means `solar energy recuperation from road surfaces`. This pilot unit having been conceived, researched an applied to a bridge on the Swiss national expressway A8 near Daerligen on the south side of the lake of Thun was officially opened on 22nd August 1994. Heat exchanger tubes carrying a water/glycol heat transfer fluid were built into the roadbed on the bridge, covering a total area of some 1`300 m{sup 2}. In summer these collect heat from the exposed carriageways, which is then transported in a closed hydraulic circuit to the neighbouring cylindrical underground rock heat storage volume. Within a diameter of 31.5 m and a depth of 65 m heat is exchanged between the heat transfer fluid and the rock via an array of 91 borehole heat exchangers. The operation of the pilot plant has been accompanied by detailed measurement campaign, whereby a total of 132 sensors are interrogated by remote datalogger. The data consist of temperature measurements at several depths and positions both in the roadbed and in the rock storage volume, of energy fluxes in the hydraulic system and of relevant meteorological data. The experiences gianed during the first two years of operation have shown that sufficient heat can indeed be collected in summer to maintain the bridge free of ice during the following winter. Moreover the energy balances derived from the measurements in the low temperature rock heat store have confirmed the predicted storage efficiency. (orig./AKF) [Deutsch] cVerkehrsflaechen heizen sich im Sommer durch Sonneneinstrahlung stark auf. Diese Sommerwaerme zu sammeln, zwischenzuspeichern und im Winter zur Verhinderung von Glatteisbildung wieder zu

  16. Winter survival of Scots pine seedlings under different snow conditions.

    Science.gov (United States)

    Domisch, Timo; Martz, Françoise; Repo, Tapani; Rautio, Pasi

    2018-04-01

    Future climate scenarios predict increased air temperatures and precipitation, particularly at high latitudes, and especially so during winter. Soil temperatures, however, are more difficult to predict, since they depend strongly on the fate of the insulating snow cover. 'Rain-on-snow' events and warm spells during winter can lead to thaw-freeze cycles, compacted snow and ice encasement, as well as local flooding. These adverse conditions could counteract the otherwise positive effects of climatic changes on forest seedling growth. In order to study the effects of different winter and snow conditions on young Scots pine (Pinus sylvestris L.) seedlings, we conducted a laboratory experiment in which 80 1-year-old Scots pine seedlings were distributed between four winter treatments in dasotrons: ambient snow cover (SNOW), compressed snow and ice encasement (ICE), flooded and frozen soil (FLOOD) and no snow (NO SNOW). During the winter treatment period and a 1.5-month simulated spring/early summer phase, we monitored the needle, stem and root biomass of the seedlings, and determined their starch and soluble sugar concentrations. In addition, we assessed the stress experienced by the seedlings by measuring chlorophyll fluorescence, electric impedance and photosynthesis of the previous-year needles. Compared with the SNOW treatment, carbohydrate concentrations were lower in the FLOOD and NO SNOW treatments where the seedlings had almost died before the end of the experiment, presumably due to frost desiccation of aboveground parts during the winter treatments. The seedlings of the ICE treatment showed dead needles and stems only above the snow and ice cover. The results emphasize the importance of an insulating and protecting snow cover for small forest tree seedlings, and that future winters with changed snow patterns might affect the survival of tree seedlings and thus forest productivity.

  17. 77 FR 7000 - Fisheries of the Northeastern United States; Northeast Multispecies Fishery; Gulf of Maine Winter...

    Science.gov (United States)

    2012-02-10

    ... Fishery; Gulf of Maine Winter Flounder Catch Limit Revisions AGENCY: National Marine Fisheries Service... criteria for Gulf of Maine (GOM) winter flounder and associated increases in GOM winter flounder catch... year (FY) 2011 GOM winter flounder catch levels, including Overfishing Levels (OFLs), Acceptable...

  18. Mapping of QTLs for leaf area and the association with winter ...

    African Journals Online (AJOL)

    Variations in plant architecture are often associated with the ability of plants to survive cold stress during winter. In studies of winter hardiness in lentil, it appeared that small leaf area was associated with improved winter survival. Based on this observation, the inheritance of leaf area and the relationship with winter ...

  19. 75 FR 76405 - Winter Bee, Inc., Provisional Acceptance of a Settlement Agreement and Order

    Science.gov (United States)

    2010-12-08

    ... CONSUMER PRODUCT SAFETY COMMISSION [CPSC Docket No. 11-C0002] Winter Bee, Inc., Provisional...(e).\\1\\ Published below is a provisionally-accepted Settlement Agreement with Winter Bee, Inc... 1. In accordance with 16 CFR 1118.20, Winter Bee, Inc. (``Winter Bee'') and the staff (``Staff'') of...

  20. Addressing challenges for youths with mobility devices in winter conditions.

    Science.gov (United States)

    Morales, Ernesto; Lindsay, Sally; Edwards, Geoffrey; Howell, Lori; Vincent, Claude; Yantzi, Nicole; Gauthier, Véronique

    2018-01-01

    Winter-related research about the experience of navigating in the urban context has mostly focused on the elderly population with physical disabilities. The aim of this project was to explore potential design solutions to enhance young people's mobility devices and the built environment to improve accessibility and participation in winter. A multi-method qualitative design process included the following steps: (1) in-depth interviews; (2) photo elicitation; (3) individual co-design sessions; and (4) group co-design sessions (i.e., focus group). The participants were 13 youths (nine males and four females), aged 12-21, who used a wheelchair (12 power chair users and one manual wheelchair), for some with their parents, others without their parents, according to the parents' willingness to participate or not in the study (n = 13). The first two authors conducted group co-design sessions with mechanical engineers and therapists/clinicians in two Canadian cities to discuss the feasibility of the designs. Results (findings): The youths and their parents reported different winter-related challenges and proposed specific design solutions to enhance their participation and inclusion in winter activities. Seven of these designs were presented at two group co-design sessions of therapists/clinicians and engineers. Two designs were found to be feasible: (1) a traction device for wheelchairs in snow and (2) a mat made of rollers to clean snow and dirt from tires. The results of this research highlight the frustrations and challenges youths who use wheelchairs encounter in winter and a need for new solutions to ensure greater accessibility in winter. Therapists/clinicians and designers should address winter-related accessibility problems in areas with abundant snow. Implications for Rehabilitation Several studies show that current urban contexts do not necessarily respond accurately to the needs of individuals with limited mobility. Winter-related research about the

  1. THE EVOLUTION OF THE WINTER PARALYMPIC GAMES AND SPORTS

    Directory of Open Access Journals (Sweden)

    Vasilios Giovanis

    2015-03-01

    Full Text Available Purpose: The aim of this research was to record and the evolution of the winter paralympic games and sports since 1976 until 2010. The history of the Winter Paralympic Games is relatively recent compared to that one of the Olympic Games. The first Games were held in 1976 in Ornskoldsvik, Sweden and the most recent, 38 years later in 2014, in Sochi, Russia. This article will examine the Winter Paralympic Games up until the ones in 2010 in Vancouver, Canada. During these years, there have been many changes in relation to the Games itself, the governing body of the Paralympic Movement, the sports’ facilities, the sports involved and sports’ categories. The motivation for writing this paper was the need to record and gather all of these items in one paper. Gathering information for the Winter Paralympic Games will be an important theoretical background. This information will create a database for the structure of the governing body of the Paralympic Games, for the organization of the Games [Local Organizing Committee (LOC, venues and equipment], for the evolution of the Winter Paralympic Sports and the categories of the athletes, as well as the evolution of the athletes’ and sports’ participation. Material : The research material that was used was mainly from the bibliography and records of the International Paralympic Committee (IPC, from the Official Post Games Reports and the Internet, while the research method that was used was descriptive. Moreover, the use of diagrams will depict the distribution of the participation of athletes and countries in each Games. Results : The participation of countries grew continuously and steadily from 16 to 44, during the years of 1976 to 2010 respectively. Regarding the athletes’ participation, starting in the first Games with 198 athletes, they reached the number of 502 in the 2010 Vancouver Winter Paralympic Games. The participation percentages of the athletes coming from Europe constituted the bulk

  2. Genetic architecture of winter hardiness and frost tolerance in triticale.

    Directory of Open Access Journals (Sweden)

    Wenxin Liu

    Full Text Available Abiotic stress experienced by autumn-sown crops during winter is of great economic importance as it can have a severe negative impact on yield. In this study, we investigated the genetic architecture of winter hardiness and frost tolerance in triticale. To this end, we used a large mapping population of 647 DH lines phenotyped for both traits in combination with genome-wide marker data. Employing multiple-line cross QTL mapping, we identified nine main effect QTL for winter hardiness and frost tolerance of which six were overlapping between both traits. Three major QTL were identified on chromosomes 5A, 1B and 5R. In addition, an epistasis scan revealed the contribution of epistasis to the genetic architecture of winter hardiness and frost tolerance in triticale. Taken together, our results show that winter hardiness and frost tolerance are complex traits that can be improved by phenotypic selection, but also that genomic approaches hold potential for a knowledge-based improvement of these important traits in elite triticale germplasm.

  3. Suitability of Starch Syrups for Winter Feeding of Honeybee Colonies

    Directory of Open Access Journals (Sweden)

    Semkiw Piotr

    2016-12-01

    Full Text Available Three different starch syrups available on the Polish market for winter feeding of bees were evaluated for two consecutive beekeeping seasons (2012/2013 and 2013/2014. Sugar syrup and inverted sucrose syrup were used as the control. Winter feeding was conducted at two times: earlier and later in the season. After supplementation of winter feeding was stopped, we measured colony strength (number of combs covered by bees and brood area. After overwintering (spring 2013 and 2014, we estimated the influence of these foods on: bee mortality during overwintering (number of dead bees in winter debris, food consumption, colony strength and brood area in spring (two measurements in three-week intervals, development dynamics and honey yield from spring flow. An analysis of the results for the parameters assessed before overwintering, after its end and during spring development did not show significant differences between bee colonies fed with different types of food. No relevant difficulties concerning food crystallisation were encountered. The analysed syrups turned out to be as suitable for winter feeding of bees as sugar and inverted sucrose syrups.

  4. Learning at old age: a study on winter bees

    Directory of Open Access Journals (Sweden)

    Andreas Behrends

    2010-04-01

    Full Text Available Ageing is often accompanied by a decline in learning and memory abilities across the animal kingdom. Understanding age-related changes in cognitive abilities is therefore a major goal of current research. The honey bee is emerging as a novel model organism for age-related changes in brain function, because learning and memory can easily be studied in bees under controlled laboratory conditions. In addition, genetically similar workers naturally display life expectancies from six weeks (summer bees to six months (winter bees. We studied whether in honey bees, extreme longevity leads to a decline in cognitive functions. Six-month-old winter bees were conditioned either to odours or to tactile stimuli. Afterwards, long-term memory and discrimination abilities were analysed. Winter bees were kept under different conditions (flight /no flight opportunity to test for effects of foraging activity on learning performance. Despite their extreme age, winter bees did not display an age-related decline in learning or discrimination abilities, but had a slightly impaired olfactory long-term memory. The opportunity to forage indoors led to a slight decrease in learning performance. This suggests that in honey bees, unlike in most other animals, age per se does not impair associative learning. Future research will show which mechanisms protect winter bees from age-related deficits in learning.

  5. Marine assemblages respond rapidly to winter climate variability.

    Science.gov (United States)

    Morley, James W; Batt, Ryan D; Pinsky, Malin L

    2017-07-01

    Even species within the same assemblage have varied responses to climate change, and there is a poor understanding for why some taxa are more sensitive to climate than others. In addition, multiple mechanisms can drive species' responses, and responses may be specific to certain life stages or times of year. To test how marine species respond to climate variability, we analyzed 73 diverse taxa off the southeast US coast in 26 years of scientific trawl survey data and determined how changes in distribution and biomass relate to temperature. We found that winter temperatures were particularly useful for explaining interannual variation in species' distribution and biomass, although the direction and magnitude of the response varied among species from strongly negative, to little response, to strongly positive. Across species, the response to winter temperature varied greatly, with much of this variation being explained by thermal preference. A separate analysis of annual commercial fishery landings revealed that winter temperatures may also impact several important fisheries in the southeast United States. Based on the life stages of the species surveyed, winter temperature appears to act through overwinter mortality of juveniles or as a cue for migration timing. We predict that this assemblage will be responsive to projected increases in temperature and that winter temperature may be broadly important for species relationships with climate on a global scale. © The Authors Global Change Biology Published by John Wiley & Sons Ltd.

  6. Winter storm-related injuries in Oklahoma, January 2007.

    Science.gov (United States)

    Piercefield, Emily; Wendling, Tracy; Archer, Pam; Mallonee, Sue

    2011-02-01

    A January 2007 ice storm occurred in Oklahoma, causing power outages and hazardous travel conditions. The objective of this investigation was to describe the nature of winter storm-related injuries among Oklahoma residents, to determine populations at risk, and to inform prevention-planning personnel. Winter storm-related injuries were a temporarily reportable condition; all acute-care hospitals and the state medical examiner logged storm-related injuries and deaths during January 12-30, 2007. Medical records were retrospectively abstracted. Risk of injury was described by demographic group, injury type, and mechanism. Among 6,047 persons experiencing winter storm-related injuries, 74% were injured in falls, 13% in motor-vehicle collisions (MVCs), 8% while sledding, 1% by unintentional carbon monoxide poisoning, 1% in cleanup activities, and 3% by other mechanisms. Median age of injured persons was 39years. Persons aged ≥ 40 years were 1.4 times more likely to experience falls as the cause of injury than those aged falls were twice as likely as other mechanisms to cause fractures among persons aged ≥ 40 years. Injured persons aged older persons were more likely to experience falls and fractures. Prevention messages for winter storm-related injuries should target winter-driving safety tips to younger adults and precautions regarding falls to older adults. Published by Elsevier Ltd.

  7. Physiological responses of Yellowstone bison to winter nutritional deprivation

    Science.gov (United States)

    DelGiudice, Glenn D.; Singer, Francis J.; Seal, Ulysses S.; Bowser, Gillian

    1994-01-01

    Because nutrition is critically related to other aspects of bison (Bison bison) ecology, and the winter ranges inhabited by bison in Yellowstone National Park (YNP) are ecologically diverse, it was important to determine if nutritional deprivation differences occurred among winter ranges. We used chemistry profiles of urine suspended in snow to compare nutritional deprivation of bison from January to April 1988 on 4 sampling areas of 3 winter ranges in YNP. Declining (P creatinine ratios in bison on all 4 sampling areas indicated progressive nutritional deprivation through late March. Concurrent increases (P ≤ 0.001) in mean urea nitrogen: creatinine ratios from late February through late march in 3 of 4 areas suggested that increased net catabolism was occurring. Diminished creatinine ratios of sodium and phosphorus reflected low dietary intake of these minerals throughout winter. Mean values and trends of urinary characteristics indicated nutritional deprivation varied among 3 winter ranges in YNP. Continued physiological monitoring of nutritional deprivation, along with detailed examination of other aspects of the bison's ecology, will provide greater insight into the role of ungulate nutrition in the dynamics of such a complex system and improve management.

  8. Weather Support for the 2002 Winter Olympic and Paralympic Games.

    Science.gov (United States)

    Horel, J.; Potter, T.; Dunn, L.; Steenburgh, W. J.; Eubank, M.; Splitt, M.; Onton, D. J.

    2002-02-01

    The 2002 Winter Olympic and Paralympic Games will be hosted by Salt Lake City, Utah, during February-March 2002. Adverse weather during this period may delay sporting events, while snow and ice-covered streets and highways may impede access by the athletes and spectators to the venues. While winter snowstorms and other large-scale weather systems typically have widespread impacts throughout northern Utah, hazardous winter weather is often related to local terrain features (the Wasatch Mountains and Great Salt Lake are the most prominent ones). Examples of such hazardous weather include lake-effect snowstorms, ice fog, gap winds, downslope windstorms, and low visibility over mountain passes.A weather support system has been developed to provide weather information to the athletes, games officials, spectators, and the interested public around the world. This system is managed by the Salt Lake Olympic Committee and relies upon meteorologists from the public, private, and academic sectors of the atmospheric science community. Weather forecasting duties will be led by National Weather Service forecasters and a team of private, weather forecasters organized by KSL, the Salt Lake City NBC television affiliate. Other government agencies, commercial firms, and the University of Utah are providing specialized forecasts and support services for the Olympics. The weather support system developed for the 2002 Winter Olympics is expected to provide long-term benefits to the public through improved understanding,monitoring, and prediction of winter weather in the Intermountain West.

  9. Winter climate change: a critical factor for temperate vegetation performance.

    Science.gov (United States)

    Kreyling, Juergen

    2010-07-01

    Winter ecological processes are important drivers of vegetation and ecosystem functioning in temperate ecosystems. There, winter conditions are subject to rapid climate change. The potential loss of a longer-lasting snow cover with implications to other plant-related climate parameters and overwintering strategies make the temperate zone particularly vulnerable to winter climate change. A formalized literature search in the ISI Web of Science shows that plant related research on the effects of winter climate change is generally underrepresented. Temperate regions in particular are rarely studied in this respect, although the few existing studies imply strong effects of winter climate change on species ranges, species compositions, phenology, or frost injury. The generally positive effect of warming on plant survival and production may be counteracted by effects such as an increased frost injury of roots and shoots, an increased insect pest risk, or a disrupted synchrony between plants and pollinators. Based on the literature study, gaps in current knowledge are discussed. Understanding the relative effects of interacting climate parameters, as well as a stronger consideration of shortterm events and variability of climatic conditions is urgent. With respect to plant response, it would be particularly worthwhile to account for hidden players such as pathogens, pollinators, herbivores, or fungal partners in mycorrhization.

  10. Unusually cold and dry winters increase mortality in Australia.

    Science.gov (United States)

    Huang, Cunrui; Chu, Cordia; Wang, Xiaoming; Barnett, Adrian G

    2015-01-01

    Seasonal patterns in mortality have been recognised for decades, with a marked excess of deaths in winter, yet our understanding of the causes of this phenomenon is not yet complete. Research has shown that low and high temperatures are associated with increased mortality independently of season; however, the impact of unseasonal weather on mortality has been less studied. In this study, we aimed to determine if unseasonal patterns in weather were associated with unseasonal patterns in mortality. We obtained daily temperature, humidity and mortality data from 1988 to 2009 for five major Australian cities with a range of climates. We split the seasonal patterns in temperature, humidity and mortality into their stationary and non-stationary parts. A stationary seasonal pattern is consistent from year-to-year, and a non-stationary pattern varies from year-to-year. We used Poisson regression to investigate associations between unseasonal weather and an unusual number of deaths. We found that deaths rates in Australia were 20-30% higher in winter than summer. The seasonal pattern of mortality was non-stationary, with much larger peaks in some winters. Winters that were colder or drier than a typical winter had significantly increased death risks in most cities. Conversely summers that were warmer or more humid than average showed no increase in death risks. Better understanding the occurrence and cause of seasonal variations in mortality will help with disease prevention and save lives. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Migration and winter distribution of the Chestnutcollared Longspur

    Directory of Open Access Journals (Sweden)

    Ellison Kevin

    2017-12-01

    Full Text Available The Chestnut-collared Longspur (Calcarius ornatus is one of five grassland songbirds, endemic within North America, with populations that have declined >65% since the 1960s. These species breed and winter in the northern and southern Great Plains, respectively. Identifying migration routes, wintering sites, and the timing of their habitat use is key for understanding the relative magnitude of threats across the annual cycle and effectively targeting habitats for conservation. We tracked migratory movements of seven Chestnut-collared Longspurs with light-level geolocators deployed in Canada. Individuals wintered up to 112-1,200km apart. All followed the Central Flyway, circumvented high-elevation terrain, and traveled east of the breeding location. Unlike most songbirds, the durations of spring and fall migrations were similar; on average 42 ± 7d and 41 ± 5d during fall and spring migrations, respectively, for an approximately 2,000km migration; this highlights the need to better understand habitat requirements during migration for grassland songbirds. Using geospatial habitat data, we assessed winter distribution overlap with four other endemic grassland songbirds; wintering range overlapped 63-99%. Future studies should use more precise devices (e.g., archival GPS units, programmed for data collection dates from this study, to identify specific migratory sites for better conserving this and associated grassland species.

  12. Temperature-associated dynamics of songbird winter distributions and abundances.

    Science.gov (United States)

    Butler, J Russell; MacMynowski, Dena P; Laurent, Chad; Root, Terry L

    2007-12-01

    Using Christmas Bird Count data, we analyze the annual spatio-temporal abundances of six passerine species in the upper Great Plains, US (1960-1990). This study provides new insight into how global warming could cause separation of species within present-day communities. We find that winter relative abundances of similarly-sized songbirds are differentially affected by ambient winter temperature. As such, average annual winter temperature fluctuations (i.e., severity of winter) are significantly (P < 0.05) correlated with the relative abundances of three species while the other three are not. Our conditional probability-of-occurrence analysis indicates that the abundances of the three temperature-associated species declined markedly below -4 degrees C while the abundances of the other three species fluctuated little from 8 degrees C to -16 degrees C. We conclude that even in colder climates i) the winter distributions of some, but not all, songbirds are directly or indirectly limited by temperature; and ii) these birds have dynamic abundances that can quickly respond to temperature changes.

  13. Polonium-210 and lead-210 in the Southern Polar Ocean: Naturally occurring tracers of biological and hydrographical processes in the surface waters of the Antarctic Circumpolar Current and the Weddell Sea; Polonium-210 und Blei-210 im Suedpolarmeer: Natuerliche Tracer fuer biologische und hydrographische Prozesse im Oberflaechenwasser des Antarktischen Zirkumpolarstroms und des Weddellmeeres

    Energy Technology Data Exchange (ETDEWEB)

    Friedrich, J.

    1997-11-01

    In this thesis the distribution of {sup 210}Po and {sup 210}Pb in the upper 600 m of the Antarctic Circumpolar Current and the Weddell Sea was investigated along north-south transects in austral spring and autumn. {sup 210}Po and {sup 210}Pb can serve as sensitive tracers for the special hydrographic conditions of the Antarctic Circumpolar Current and the Weddell Sea as well as for biological processes during phytoplankton blooms. The {sup 210}Po/{sup 210}Pb disequilibrium was used as a tracer for particle export. This tracer integrates export on a timescale of 276 days because of the 138 day half-life of {sup 210}Po and complements the {sup 234}Th/{sup 238}U disequilibrium as another tracer for plankton production and export on a shorter timescale of several weeks. (orig.) [Deutsch] In der vorliegenden Arbeit wurde die Verteilung von Blei-210 und seinem Enkelnuklid Polonium-210 im Antarktischen Zirkumpolarstrom und im Weddellmeer bis 600 m Tiefe in mehreren meridionalen Transekten im australen Fruehjahr und Herbst waehrend der `Polarstern`-Expeditionen ANT-X/6 und ANT-XI/4 untersucht. Die Verteilung von {sup 210}Pb und {sup 210}Po wird von mehreren Faktoren beeinflusst, sowohl durch die Advektion von Wassermassen im Antarktischen Zirkumpolarstrom und im Weddellmeer als auch von biologischen Prozessen z.B. innerhalb einer Planktonbluete. Bevor die Verteilungsmuster von {sup 210}Pb und {sup 210}Po jedoch als Tracer fuer einen Prozess genutzt werden koennen, muss der Effekt der einzelnen Faktoren auf die Verteilung betrachtet werden. (orig.)

  14. Echo Meadows Project Winter Artificial Recharge.

    Energy Technology Data Exchange (ETDEWEB)

    Ziari, Fred

    2002-12-19

    This report discusses the findings of the Echo Meadows Project (BPA Project 2001-015-00). The main purpose of this project is to artificially recharge an alluvial aquifer, WITH water from Umatilla River during the winter high flow period. In turn, this recharged aquifer will discharge an increased flow of cool groundwater back to the river, thereby improving Umatilla River water quality and temperature. A considerable side benefit is that the Umatilla River should improve as a habitat for migration, spanning, and rearing of anadromous and resident fish. The scope of this project is to provide critical baseline information about the Echo Meadows and the associated reach of the Umatilla River. Key elements of information that has been gathered include: (1) Annual and seasonal groundwater levels in the aquifer with an emphasis on the irrigation season, (2) Groundwater hydraulic properties, particularly hydraulic conductivity and specific yield, and (3) Groundwater and Umatilla River water quality including temperature, nutrients and other indicator parameters. One of the major purposes of this data gathering was to develop input to a groundwater model of the area. The purpose of the model is to estimate our ability to recharge this aquifer using water that is only available outside of the irrigation season (December through the end of February) and to estimate the timing of groundwater return flow back to the river. We have found through the data collection and modeling efforts that this reach of the river had historically returned as much as 45 cubic feet per second (cfs) of water to the Umatilla River during the summer and early fall. However, this return flow was reduced to as low as 10 cfs primarily due to reduced quantities of irrigation application, gain in irrigation efficiencies and increased groundwater pumping. Our modeling indicated that it is possible to restore these critical return flows using applied water outside of the irrigation season. We further

  15. Phytoplankton and pigment patterns across frontal zones in the Atlantic sector of the Southern Ocean

    NARCIS (Netherlands)

    van Leeuwe, Maria A.; Kattner, Gerhard; van Oijen, Tim; de Jong, Jeroen T. M.; de Baar, Hein J.W.

    2015-01-01

    Phytoplankton distribution and concentrations of macronutrients and iron were studied in the Polar Frontal Zone (PFZ) and the eastern Weddell Gyre of the Southern Ocean, during austral autumn. HPLC analysis of algal pigments was combined with microscopy observations to assess algal distribution.

  16. The long term variation in the ionospheric winter absorption anomaly

    International Nuclear Information System (INIS)

    Beynon, W.J.G.; Williams, E.R.

    1976-01-01

    An analysis of vertical incidence absorption data for a mid-latitude station (Freiburg 48 0 N 7.5 0 E) for the 13-year period 1957 to 1969 shows that there is a solar cycle variation both in the number of winter anomaly days and in the magnitude of the absorption anomaly. The magnitude of this variation is discussed in relation to solar X-ray flux and to geomagnetic disturbance. The magnitude of winter anomaly absorption is a maximum in the frequency range 2 to 2.5 MHz. Comparison of the winter anomaly phenomenon at a range of mid-latitude stations suggests that there may be small longitude variation in the magnitude of the phenomenon. (author)

  17. The impact of winter heating on air pollution in China.

    Science.gov (United States)

    Xiao, Qingyang; Ma, Zongwei; Li, Shenshen; Liu, Yang

    2015-01-01

    Fossil-fuel combustion related winter heating has become a major air quality and public health concern in northern China recently. We analyzed the impact of winter heating on aerosol loadings over China using the MODIS-Aqua Collection 6 aerosol product from 2004-2012. Absolute humidity (AH) and planetary boundary layer height (PBL) -adjusted aerosol optical depth (AOD*) was constructed to reflect ground-level PM2.5 concentrations. GIS analysis, standard statistical tests, and statistical modeling indicate that winter heating is an important factor causing increased PM2.5 levels in more than three-quarters of central and eastern China. The heating season AOD* was more than five times higher as the non-heating season AOD*, and the increase in AOD* in the heating areas was greater than in the non-heating areas. Finally, central heating tend to contribute less to air pollution relative to other means of household heating.

  18. Controls on winter ecosystem respiration in temperate and boreal ecosystems

    Directory of Open Access Journals (Sweden)

    T. Wang

    2011-07-01

    Full Text Available Winter CO2 fluxes represent an important component of the annual carbon budget in northern ecosystems. Understanding winter respiration processes and their responses to climate change is also central to our ability to assess terrestrial carbon cycle and climate feedbacks in the future. However, the factors influencing the spatial and temporal patterns of winter ecosystem respiration (Reco of northern ecosystems are poorly understood. For this reason, we analyzed eddy covariance flux data from 57 ecosystem sites ranging from ~35° N to ~70° N. Deciduous forests were characterized by the highest winter Reco rates (0.90 ± 0.39 g C m−2 d−1, when winter is defined as the period during which daily air temperature remains below 0 °C. By contrast, arctic wetlands had the lowest winter Reco rates (0.02 ± 0.02 g C m−2 d−1. Mixed forests, evergreen needle-leaved forests, grasslands, croplands and boreal wetlands were characterized by intermediate winter Reco rates (g C m−2 d−1 of 0.70(±0.33, 0.60(±0.38, 0.62(±0.43, 0.49(±0.22 and 0.27(±0.08, respectively. Our cross site analysis showed that winter air (Tair and soil (Tsoil temperature played a dominating role in determining the spatial patterns of winter Reco in both forest and managed ecosystems (grasslands and croplands. Besides temperature, the seasonal amplitude of the leaf area index (LAI, inferred from satellite observation, or growing season gross primary productivity, which we use here as a proxy for the amount of recent carbon available for Reco in the subsequent winter, played a marginal role in winter CO2 emissions from forest ecosystems. We found that winter Reco sensitivity to temperature variation across space (

  19. Ice and mineral licks used by caribou in winter

    Directory of Open Access Journals (Sweden)

    Douglas C. Heard

    1990-09-01

    Full Text Available In winter, barren-ground caribou obtain minerals from ice and soil licks. Between December and April we have seen caribou cratering on the surface of frozen lakes and licking the ice. Ice samples from eight licks on four lakes contained concentrations of calcium, magnesium, sodium, potassium, phosphorus, chloride and sulphate many times higher than in the surrounding unlicked ice or than would be expected in lake water. Soil licks being used in March and June had high concentrations of calcium, magnesium, sodium phosphorus and potassium. In winter caribou may be seeking supplements of all of the major mineral elements (calcium, magnesium, sodium and potassium at ice and soil licks because lichens, their staple winter diet, are low in minerals and may also reduce the absorption of some minerals.

  20. The Impact of Winter Heating on Air Pollution in China

    Science.gov (United States)

    Xiao, Qingyang; Ma, Zongwei; Li, Shenshen; Liu, Yang

    2015-01-01

    Fossil-fuel combustion related winter heating has become a major air quality and public health concern in northern China recently. We analyzed the impact of winter heating on aerosol loadings over China using the MODIS-Aqua Collection 6 aerosol product from 2004–2012. Absolute humidity (AH) and planetary boundary layer height (PBL) -adjusted aerosol optical depth (AOD*) was constructed to reflect ground-level PM2.5 concentrations. GIS analysis, standard statistical tests, and statistical modeling indicate that winter heating is an important factor causing increased PM2.5 levels in more than three-quarters of central and eastern China. The heating season AOD* was more than five times higher as the non-heating season AOD*, and the increase in AOD* in the heating areas was greater than in the non-heating areas. Finally, central heating tend to contribute less to air pollution relative to other means of household heating. PMID:25629878

  1. Effects of sowing time on pink snow mould, leaf rust and winter damage in winter rye varieties in Finland

    Directory of Open Access Journals (Sweden)

    M. SERENIUS

    2008-12-01

    Full Text Available Disease infection in relation to sowing time of winter rye (Secale cereale was studied in southern Finland in order to compare overwintering capacity of modern rye varieties and to give recommendations for rye cultivation. This was done by using three sowing times and four rye varieties in field trials conducted at three locations in 1999–2001. The early sown rye (beginning of August was severely affected by diseases caused by Puccinia recondita and Microdochium nivale, whereas postponing sowing for two weeks after the recommended sowing time resulted in considerably less infection. The infection levels of diseases differed among rye varieties. Finnish rye varieties Anna and Bor 7068 were more resistant to snow mould and more winter hardy than the Polish variety Amilo, or the German hybrid varieties Picasso and Esprit. However, Amilo was the most resistant to leaf rust. In the first year snow mould appeared to be the primary cause of winter damage, but in the second year the winter damage was positively correlated with leaf rust. No significant correlation between frit fly infestation and winter damage or disease incidence of snow mould or leaf rust was established. The late sowing of rye (in the beginning of September is recommended in Finland, particularly with hybrid varieties, to minimize the need for chemical plant protection in autumn.;

  2. Sustainable winter cities: Future directions for planning, policy and design

    Science.gov (United States)

    Pressman, Norman E. P.

    Attempts to generate a "climate-responsive" northern urban form are part of a relatively recent phenomenon and field of investigation. In conjunction with the international "winter cities" movement, the need has been established for explicit, systematic inquiry directed toward national and local action to improve the comfort and lifestyles of all northern inhabitants. It is important to recognize that winter-induced discomforts exist and that they must be acknowledged in planning theory and practice. For northern cities to function more satisfactorily, the negative impacts of winter must be reduced while its beneficial characteristics are enhanced. While not all summer activities can or should be abandoned during winter, proper micro-climatic control is essential if human life is to be retained outside. The outdoor season should be extended since so much indoor isolation occurs. The main principles to be incorporated in exemplary "winter city" design should be contact with nature, year-round usability, user participation, cultural continuity, and the creation of comfortable micro-climatic conditions throughout much of the city's open spaces. All valuable sources of inspiration must be harnessed in the attempt to mediate between organic regionalism and internationalism, on the one hand, and romanticism and pragmatic realism, on the other. Creating optimum conditions for human well-being, habitation, work and intellectual development in each of the four seasons is vital under harsh environments. Adopting a climate-sensitive approach to planning policy and urban design can render everyday life less stressful, especially during the lengthy winter periods found in many northern latitude and high altitude settings.

  3. Vancouver winters: Environmental influences on inpatient adult orthopaedic trauma demographics

    International Nuclear Information System (INIS)

    Noordin, S.; Masri, B. A.

    2014-01-01

    Objective: To compare the pattern of adult inpatient orthopaedic injuries admitted at three Vancouver hospitals following one of the worst winter snowstorms in the region with the preceding control winter period. Methods: The surveillance study was conducted at the University of British Columbia, Vancouver, Canada, 2007 to 2010. Inpatient adult admissions for orthopaedic injuries at three hospitals were recorded, including age, gender, anatomic location of injury, type of fracture (open or closed), fixation method (internal versus external fixation), and length of acute care hospital stay. Comparisons between admissions during this weather pattern and admission during a previous winter with minimal snow were made. SPSS 19 was used for statistical analysis. Results: Of the 511 patients admitted under Orthopaedic trauma service during the significant winter snowstorms of December 2008 - January 2009, 100 (19.6%) (CI: 16.2%-23.2%) were due to ice and snow, whereas in the preceding mild winter only 18 of 415 (4.3%) (CI: 2.5%-6.8%) cases were related to snow (p<0.05). Ankle and wrist fractures were the most frequent injuries during the index snow storm period (p<0.05). At all the three institutions, 97 (96.5%) fractures were closed during the snowstorm as opposed to 17 (95%) during the control winter period. Internal fixation in 06 (89%) fractures as opposed to external fixation in 12 (11%) patients was the predominant mode of fixation across the board during both time periods. Conclusion: The study demonstrated a significantly higher inpatient orthopaedic trauma volume during the snowstorm more rigorous prospective studies need to be designed to gain further insight to solving these problems from a public health perspective. (author)

  4. The importance of agricultural lands for Himalayan birds in winter.

    Science.gov (United States)

    Elsen, Paul R; Kalyanaraman, Ramnarayan; Ramesh, Krishnamurthy; Wilcove, David S

    2017-04-01

    The impacts of land-use change on biodiversity in the Himalayas are poorly known, notwithstanding widespread deforestation and agricultural intensification in this highly biodiverse region. Although intact primary forests harbor many Himalayan birds during breeding, a large number of bird species use agricultural lands during winter. We assessed how Himalayan bird species richness, abundance, and composition during winter are affected by forest loss stemming from agriculture and grazing. Bird surveys along 12 elevational transects within primary forest, low-intensity agriculture, mixed subsistence agriculture, and intensively grazed pastures in winter revealed that bird species richness and abundance were greatest in low-intensity and mixed agriculture, intermediate in grazed pastures, and lowest in primary forest at both local and landscape scales; over twice as many species and individuals were recorded in low-intensity agriculture than in primary forest. Bird communities in primary forests were distinct from those in all other land-use classes, but only 4 species were unique to primary forests. Low-, medium-, and high-intensity agriculture harbored 32 unique species. Of the species observed in primary forest, 80% had equal or greater abundance in low-intensity agricultural lands, underscoring the value of these lands in retaining diverse community assemblages at high densities in winter. Among disturbed landscapes, bird species richness and abundance declined as land-use intensity increased, especially in high-intensity pastures. Our results suggest that agricultural landscapes are important for most Himalayan bird species in winter. But agricultural intensification-especially increased grazing-will likely result in biodiversity losses. Given that forest reserves alone may inadequately conserve Himalayan birds in winter, comprehensive conservation strategies in the region must go beyond protecting intact primary forests and ensure that low-intensity agricultural

  5. Proceedings of the EuBIC Winter School 2017

    DEFF Research Database (Denmark)

    Willems, Sander; Bouyssié, David; David, Matthieu

    2017-01-01

    The 2017 EuBIC Winter School was held from January 10th to January 13th 2017 in Semmering, Austria. This meeting gathered international researchers in the fields of bioinformatics and proteomics to discuss current challenges in data analysis and biological interpretation. This article outlines...... the scientific program and exchanges that took place on this occasion and presents the current challenges of this ever-growing field. Biological significance The EUPA bioinformatics community (EuBIC) organized its first winter school in January 2017. This successful event illustrates the growing need...

  6. Winter distribution of Calanus finmarchicus in the Northeast Atlantic

    DEFF Research Database (Denmark)

    Heath, M.R.; Fraser, J.G.; Gislason, A.

    2000-01-01

    Data from plankton sampling and Optical Plankton Counter deployments during six cruises between December of 1994 and 1999 have been used to derive a composite three-dimensional distribution of the abundance of Calanus finmarchicus during winter (December-January) in the Norwegian Sea and Northeast...... Northeast Atlantic, the concentration of wintering animals is around 30% of that in the Norwegian Sea and the vertical distribution is more diffuse and on average deeper. Modelling studies have shown that the overwinter distribution and transport are key factors determining the spatial persistence of C...

  7. Tebuconazole Regulates Fatty Acid Composition of Etiolated Winter Wheat Seedlings

    OpenAIRE

    A.V. Korsukova; T.G. Gornostai; O.I. Grabelnych; N.V. Dorofeev; T.P. Pobezhimova; N.A. Sokolova; L.V. Dudareva; V.K. Voinikov

    2016-01-01

    The fatty acid composition of shoots of unhardened and hardened to cold etiolated winter wheat seedlings grown from seeds treated with tebuconazole-based protectant «Bunker» (content of tebuconazole 60 grams per liter, g/L), and the seedlings frost resistance has been studied. It is shown that treatment of winter wheat seeds by «Bunker» preparation (1,5 microliter per gram of seeds, µl/g) is accompanied by an increase of the fatty acids unsaturation in the shoots and increase of the seedlings...

  8. Travel in adverse winter weather conditions by blind pedestrians.

    Science.gov (United States)

    2015-08-31

    Winter weather creates many orientation and mobility (O&M) challenges for people who are visually impaired. Getting the cane tip stuck is one of the noticeable challenges when traveling in snow, particularly when the walking surface is covered in dee...

  9. Identification of vernalization responsive genes in the winter wheat ...

    Indian Academy of Sciences (India)

    1College of Agriculture, Henan University of Science and Technology, Luoyang 471003, People's Republic of China. 2National Engineering ... Key Laboratory of Wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou 450002,. People's ..... Entz M. and Fowler D. 1991 Agronomic performance of winter.

  10. Variation in winter metabolic reduction between sympatric amphibians

    Czech Academy of Sciences Publication Activity Database

    Podhajský, Luděk; Gvoždík, Lumír

    2016-01-01

    Roč. 201, November (2016), s. 110-114 ISSN 1095-6433 R&D Projects: GA ČR(CZ) GA15-07140S Institutional support: RVO:68081766 Keywords : Caloric reserves * Ichthyosaura * Lissotriton * Metabolic rate * Newt * Oxygen consumption * Respirometry * Salamander * Thermal sensitivity * Wintering Subject RIV: EG - Zoology Impact factor: 1.812, year: 2016

  11. Winter habitat associations of diurnal raptors in Californias Central Valley

    Science.gov (United States)

    Pandolrno, E.R.; Herzog, M.P.; Hooper, S.L.; Smith, Z.

    2011-01-01

    The wintering raptors of California's Central Valley are abundant and diverse. Despite this, little information exists on the habitats used by these birds in winter. We recorded diurnal raptors along 19 roadside survey routes throughout the Central Valley for three consecutive winters between 2007 and 2010. We obtained data sufficient to determine significant positive and negative habitat associations for the White-tailed Kite (Elanus leucurus), Bald Eagle {Haliaeetus leucocephalus), Northern Harrier (Circus cyaneus), Red-tailed Hawk (Buteo jamaicensis), Ferruginous Hawk (Buteo regalis), Rough-legged Hawk (Buteo lagopus), American Kestrel (Falco sparverius), and Prairie Falcon (Falco mexicanus). The Prairie Falcon and Ferruginous and Rough-legged hawks showed expected strong positive associations with grasslands. The Bald Eagle and Northern Harrier were positively associated not only with wetlands but also with rice. The strongest positive association for the White-tailed Kite was with wetlands. The Red-tailed Hawk was positively associated with a variety of habitat types but most strongly with wetlands and rice. The American Kestrel, Northern Harrier, and White-tailed Kite were positively associated with alfalfa. Nearly all species were negatively associated with urbanized landscapes, orchards, and other intensive forms of agriculture. The White-tailed Kite, Northern Harrier, Redtailed Hawk, Ferruginous Hawk, and American Kestrel showed significant negative associations with oak savanna. Given the rapid conversion of the Central Valley to urban and intensive agricultural uses over the past few decades, these results have important implications for conservation of these wintering raptors in this region.

  12. Periphyton biomass on artificial substrates during the summer and winter

    Directory of Open Access Journals (Sweden)

    Altevir Signor

    2015-01-01

    Full Text Available This study evaluated the periphyton production on artificial substrates considering it as a source of low cost live food for fish. Blades of artificial substrates such as wood, black plastic, acrylic, fiberglass, ceramics and glass (all with 144cm2 blades, 24 for each substrate were submerged 20.0cm below the water column for 35 days in the winter and 42 days in the summer. The blades were randomly installed in 200m3 pond and evaluated for the biomass production at different phases during the summer and winter. Four blades of each substrate were collected weekly, and the periphytic community was carefully scraped with a spatula and fixed in 4% formaldehyde. The periphytic biomass productivity was evaluated by artificial substrate area and per day. The results evidenced the characteristic periodicity in periphyton biomass production and a significant variability in the collect period and season in the different artificial substrates used. Ceramic and wood showed the best results in the summer while wood showed the best results in the winter. The priphyton biomass productions differ among periods, substrates and seasons. Wood and ceramics could be indicated for periphyton biomass production in either winter or summer.

  13. Short Communication A vetch winter cover crop can improve ...

    African Journals Online (AJOL)

    A high nitrogen (N) fertiliser requirement can be a deterrent to the adoption of conservation agriculture (CA). A field trial was carried out to test whether a high biomass-yielding vetch (Vicia dasycarpa L.) winter cover crop can be used to improve N response and profitability of a subsequent maize (Zea mays L.) crop under ...

  14. Drinking behaviour in sows kept outdoors during the winter months

    DEFF Research Database (Denmark)

    Andersen, Heidi Mai-Lis; Pedersen, Lene Juul

    2014-01-01

    tIn the light of the EU regulation, “pigs must have permanent access to a sufficient quantityof fresh water” and the practical problems it provides farmers during winter to keep waterfree of ice, the aim of this study was to investigate the influence of periods with frost onthe diurnal pattern of...

  15. Genetic Potential of Winter Wheat Grain Quality in Central Asia

    Science.gov (United States)

    Abugaliyeva, Aigul I.; Morgounov, Alexey I.

    2016-01-01

    The grain quality of winter wheat varies significantly by cultivars and growing region, not previously differentiated by end-use (baking, confectionery, etc.) in the national breeding programs. In these conditions it is advisable to determine the genetic potential and analyze the actual grain quality. Determining the genetic potential requires the…

  16. Stay Warm in Winter (A Minute of Health with CDC)

    Centers for Disease Control (CDC) Podcasts

    2015-02-26

    Hypothermia occurs when the core body temperature is less than 95 degrees. This podcast discusses strategies to prevent hypothermia due to frigid winters temperatures.  Created: 2/26/2015 by MMWR.   Date Released: 2/26/2015.

  17. RESEARCH NOTE THE PERFOR]\\IANCE DURING WINTER, OF ...

    African Journals Online (AJOL)

    THE PERFOR]\\IANCE DURING WINTER, OF HETFERS FED GRASS SILAGE, MADE UNDER. UNFAVOURABLE WEATHER CONDITIONS AND E. curvula HAY, PRODUCED. FROM THE SAME SWARD. Receipt of MS: 06-10-1981. A. van Niekerk. Cedara Agriculrural Research Station, PlBag X9059, Pietermaritzburg ...

  18. Baraitser–Winter syndrome: An additional Egyptian patient with ...

    African Journals Online (AJOL)

    We report a 3.5 year old male child, second in order of birth of non consanguineous Egyptian parents with Baraitser–Winter syndrome (BRWS). The patient had bilateral colobomas of the iris and choroid. Our patient had also retinal hypoplasia, which was not reported previously in this syndrome, bilateral congenital ptosis, ...

  19. Changes in nutrient composition of kikuyu foggage as winter ...

    African Journals Online (AJOL)

    Natal from five adjoining paddocks to measure the changes in nutrient composition of the foggage as winter progressed. Leaves and stems were separated. The first samples collected on the 18th of May contained green to dry material at a ratio ...

  20. Hydrographic features of the Lakshadweep (Laccadives) sea during winter

    Digital Repository Service at National Institute of Oceanography (India)

    Das, V.K.

    Hydrographic features of the Lakshadweep Sea during winter have been studied using the data collected in December during the 13th cruise of R.V. Gaveshani. The mixed layer depth in this region varies between 30 and 70 m. The thickness...

  1. Christian IV's Winter Room and Studiolo at Rosenborg Castle

    DEFF Research Database (Denmark)

    Wadum, Jørgen

    2015-01-01

    An account of the creation of the highly decorated ensemble forming the Winter Room and the Writing Room, Christian 4s private quarters at Rosenborg Castle. Art historical, technical analysis reveals new evidence on the working practice of Danish and Antwerp artists and craftsmen in the first...

  2. Evaluation of drought tolerance indices among some winter ...

    African Journals Online (AJOL)

    The main purpose of this study was to evaluate the effect of drought stress on seed yield of some winter rapeseed cultivars and to study relevant drought tolerance indices, along with identifying resistant cultivars to drought stress. Plant materials were sown in split plot arrangement based on a randomized complete blocks ...

  3. Winter survival of Harmonia axyridis in The Netherlands

    NARCIS (Netherlands)

    Raak-van den Berg, C.L.; Stam, J.M.; Jong, de P.W.; Hemerik, L.; Lenteren, van J.C.

    2012-01-01

    Since the establishment of Harmonia axyridis in Europe, populations of native ladybirds have decreased. Overwintering survival is one of the aspects of the biology of H. axyridis that may contribute to its firm establishment in and invasion of a new area. In this study winter survival of five wild

  4. Travels in Tartary : Decoding Ten Export Winter Landscapes

    NARCIS (Netherlands)

    Poel, van der R.H.M.

    2013-01-01

    The Chinese export paintings collection of the National Museum of Ethnology in Leiden includes ten winter views in Tartary painted on canvas. That these ten paintings have never before been studied as a group has inspired the present author to conduct research into their origins, the findings of

  5. GLOBAL DECREASES IN TOTAL OZONE DURING THE WINTER MONTHS

    OpenAIRE

    タカオ, トシノリ; Toshinori, TAKAO

    1990-01-01

    Global network of total ozone measurements by Dobson spectrophotometer shows ozone decrease in recent years. At midlatitudes of the Northern Hemisphere, ozone loss was significant during the winter months of 1983 and 1985. In some regions, there is a positive correlation between the annual mean of total ozone amounts and the solar cycle.

  6. Identification of a nucleopolyhedrovirus in winter moth populations from Massachusetts

    Science.gov (United States)

    John P. Burand; Anna Welch; Woojin Kim; Vince D' Amico; Joseph S. Elkinton

    2011-01-01

    The winter moth, Operophtera brumata, originally from Europe, has recently invaded eastern Massachusetts. This insect has caused widespread defoliation of many deciduous tree species and severely damaged a variety of crop plants in the infested area including apple, strawberry, and especially blueberry.

  7. Stay Warm in Winter (A Cup of Health with CDC)

    Centers for Disease Control (CDC) Podcasts

    2015-02-26

    When frigid winter temperatures hit the U.S., the risk for unhealthy exposure to cold increases substantially. In this podcast, Dr. Jonathan Meiman discusses the dangers of exposure to extremely cold temperatures.  Created: 2/26/2015 by MMWR.   Date Released: 2/26/2015.

  8. Inferring the links between breeding and wintering grounds in a ...

    African Journals Online (AJOL)

    We used mitochondrial DNA data from wintering populations of the Great Reed Warbler (Acrocephalus arundinaceus) in western (Nigeria), southern (Botswana and Zambia) and eastern (Kenya) Africa, as well as from several Eurasian breeding populations, to compare genetic differentiation and haplotype sharing between ...

  9. Food habits of bald eagles wintering in northern Arizona

    Science.gov (United States)

    Teryl G. Grubb; Roy G. Lopez

    2000-01-01

    We used pellets collected from roosts to supplement incidental foraging observations to identify prey species of Bald Eagles (Haliaeetus leucoughalus) and to evaluate spatial and temporal trends in their food habits while wintering in northern Arizona between 1994-96. We analyzed 1057 pellets collected from 14 roosts, and identified five mammal and...

  10. Performance of Chlorella sorokiniana under simulated extreme winter conditions

    NARCIS (Netherlands)

    Cuaresma, M.; Buffing, M.F.; Janssen, M.G.J.; Lobato, C.V.; Wijffels, R.H.

    2012-01-01

    High annual microalgae productivities can only be achieved if solar light is efficiently used through the different seasons. During winter the productivity is low because of the light and temperature conditions. The productivity and photosynthetic efficiency of Chlorella sorokiniana were assessed

  11. Nutrition Frontiers - Winter 2017 | Division of Cancer Prevention

    Science.gov (United States)

    Volume 8, Issue 1 Dear Colleague, The winter issue of Nutrition Frontiers showcases gut permeability and calcium supplementation, potential chemopreventive effects of dietary DHM for lung tumorigenesis, and the role of the MCP-1 chemokine on adiposity and inflammation. Learn about our spotlight investigator, Dr. Gregory Lesinski, and his research on dietary interventions to

  12. Nutrition Frontiers - Winter 2018 | Division of Cancer Prevention

    Science.gov (United States)

    Dear Colleague, The winter issue of Nutrition Frontiers showcases the chemopreventive activity of sulforaphane, how a high fat, high cholesterol diet may impact hepatocellular carcinoma, and p53 activation from benzyl isothiocyanate. Meet our spotlight investigator, Dr. John Groopman, and his research on detoxication of air pollutants with a broccoli supplement. Learn about

  13. Wintering Golden Eagles on the coastal plain of South Carolina

    Science.gov (United States)

    Mark Vukovich; K.L. Turner; T.E. Grazia; T. Mims; J.C. Beasley; John Kilgo

    2015-01-01

    Golden Eagles (Aquila chrysaetos) are rare winter residents in eastern North America, with most found along the Appalachian Mountains and few reported on the coastal plain of the Carolinas. We used remote cameras baited with wild pig (Sus scrofa) and white-tailed deer (Odocoileus virginianus) carcasses to detect, age, and individually identify Golden Eagles on the U.S...

  14. Sagebrush-ungulate relationships on the Northern Yellowstone Winter Range

    Science.gov (United States)

    Carl L. Wambolt

    2005-01-01

    Sagebrush (Artemisia) taxa have historically been the landscape dominants over much of the Northern Yellowstone Winter Range (NYWR). Their importance to the unnaturally large ungulate populations on the NYWR throughout the twentieth century has been recognized since the 1920s. Sagebrush-herbivore ecology has been the focus of research on the NYWR for...

  15. Acute effects of winter air pollution on respiratory health

    NARCIS (Netherlands)

    Zee, van der S.

    1999-01-01

    In this thesis, acute respiratory health effects of exposure to winter air pollution are investigated in panels of children (7-11 yr) and adults (50-70 yr) with and without chronic respiratory symptoms, living in urban and non-urban areas in the Netherlands. The study was performed during

  16. Sustainable use of winter Durum wheat landraces under ...

    African Journals Online (AJOL)

    ... the two checks cultivars. Bi- plot analysis showed that some promising lines with reasonable grain yields, good quality parameters, winter hardiness and drought tolerances among yellow rust resistance durum wheat landraces can be selected for semiarid conditions of Mediterranean countries for sustainable production.

  17. Forest management strategy, spatial heterogeneity, and winter birds in Washington.

    Science.gov (United States)

    B. Haveri; A.B. Carey

    2000-01-01

    Ecological management of second-growth forest holds great promise for conservation of biodiversity, yet little experimental evidence exists to compare alternative management approaches. Wintering birds are one of several groups of species most likely to be influenced by forest management activities. We compared species richness and proportion of stand area used over...

  18. Feeding habits of songbirds in East Texas clearcuts during winter

    Science.gov (United States)

    Donald W. Worthington; R. Montague Jr. Whiting; James G. Dickson

    2004-01-01

    This east Texas study was undertaken to determine the importance of seeds of forbs, grasses, and woody shrubs to songbirds wintering in young pine plantations which had been established utilizing the clearcut regeneration system. The feeding habits and preferences of four species of songbirds, northern cardinals (Cardinalis cardinalis), song sparrows...

  19. Winter and spring variation in daily milk yield and mineral ...

    African Journals Online (AJOL)

    This study was conducted to determine the effects of genotype and season on daily milk yield (DMY) and mineral composition of pasture-based dairy cows. This was done by collecting data from 20 Friesian, 20 Jersey and 20 Friesian × Jersey crossbred cows in the early stage of their 4th parity in winter and spring, ...

  20. Experimental log hauling through a traditional caribou wintering area

    Directory of Open Access Journals (Sweden)

    Harold G. Cumming

    1998-03-01

    Full Text Available A 3-year field experiment (fall 1990-spring 1993 showed that woodland caribou (Rangifer tarandus caribou altered their dispersion when logs were hauled through their traditional wintering area. Unlike observations in control years 1 and 3, radio-collared caribou that had returned to the study area before the road was plowed on January 6 of the experimental year 2, moved away 8-60 km after logging activities began. Seasonal migration to Lake Nipigon islands usually peaked in April, but by February 22 of year 2, 4 of the 6 had returned. The islands provide summer refuge from predation, but not when the lake is frozen. Tracks in snow showed that some caribou remained but changed locations. They used areas near the road preferentially in year 1, early year 2, and year 3, but moved away 2-5 km after the road was plowed in year 2. In a nearby undisturbed control area, no such changes occurred. Caribou and moose partitioned habitat on a small scale; tracks showed gray wolf (Canis lupus remote from caribou but close to moose tracks. No predation on caribou was observed within the wintering area; 2 kills were found outside it. Due to the possibility of displacing caribou from winter refugia to places with higher predation risk, log hauling through important caribou winter habitat should be minimized.

  1. Soil water potential requirement for germination of winter wheat

    Science.gov (United States)

    In semi-arid climates seed is often sown into soil with inadequate water for rapid germination. This study was designed to measure the soil water potential limits for rapid, adequate, and marginal germination of winter wheat (Triticum aestivum L.). We also tested for differences between cultivars an...

  2. Effect of winter nutritional levels on subsequent growth of beef ...

    African Journals Online (AJOL)

    Die invloed van verskillende wintervoedingspeile op die prestasie van 300 Simmentalerspeenverse (sewe maande oud) op somerveld, is oor 'n periode van drie jaar ondersoek. Gedurende die tweede winter na speen (as 18-maande-oud diere) is die verse gevoer om 'n dekmassa van 330 kg (op 26 maande) te bereik.

  3. Winter atmospheric circulation and river discharge in northwest Europe

    NARCIS (Netherlands)

    Bouwer, L.M.; Aerts, J.C.J.H.; Vermaat, J.E.

    2006-01-01

    More frequent western atmospheric circulation over Europe results in increased precipitation in winter, and could result in increasing river discharges. We made a quantitative assessment of the impact of variation in atmospheric circulation, defined by the frequency of western circulation in the

  4. River catchment rainfall series analysis using additive Holt–Winters ...

    Indian Academy of Sciences (India)

    Conventional ways that determine rainfalltrends can only provide a general result in single direction for the whole study period. In this study, rainfall series were modelled using additive Holt–Winters method to examine the rainfall pattern in Langat River Basin, Malaysia. Nine homogeneous series of more than 25 years data ...

  5. Effects of school closures, 2008 winter influenza season, Hong Kong

    OpenAIRE

    Leung, GM; Chan, KH; Lam, CLH; Cowling, BJ; Cheng, CKY; Lau, EHY; Kovar, J; Peiris, JSM

    2008-01-01

    In winter 2008, kindergartens and primary schools in Hong Kong were closed for 2 weeks after media coverage indicated that 3 children had died, apparently from influenza. We examined prospective influenza surveillance data before, during, and after the closure. We did not find a substantial effect on community transmission.

  6. Evaluation of drought tolerance indices among some winter ...

    African Journals Online (AJOL)

    Administrator

    2011-09-14

    watering stress treatments, Irrigation “time- .... STI and GMP were studied for selecting drought-tolerant cultivars in winter rapeseed cultivars. To do so, the 3D scatter plot was used because it allowed drought-tolerant cultivars ...

  7. Use of seeded exotic grasslands by wintering birds

    Science.gov (United States)

    George, Andrew D.; O'Connell, Timothy J.; Hickman, Karen R.; Leslie,, David M.

    2013-01-01

    Despite widespread population declines of North American grassland birds, effects of anthropogenic disturbance of wintering habitat of this guild remain poorly understood. We compared avian abundance and habitat structure in fields planted by the exotic grass Old World bluestem (Bothriochloa ischaemum; OWB) to that in native mixed-grass prairie. During winters of 2007-2008 and 2008-2009, we conducted bird and vegetation surveys in six native grass and six OWB fields in Garfield, Grant, and Alfalfa counties, Oklahoma. We recorded 24 species of wintering birds in native fields and 14 species in OWB monocultures. While vegetation structure was similar between field types, abundance of short-eared owls (Asio flammeus), northern harriers (Circus cyaneus) and Smith's longspurs (Calcarius pictus) was higher in OWB fields during at least one year. The use of OWB fields by multiple species occupying different trophic positions suggested that vegetation structure of OWB can meet habitat requirements of some wintering birds, but there is insufficient evidence to determine if it provides superior conditions to native grasses.

  8. Supplementary winter feeding and reproduction of beef heifers on ...

    African Journals Online (AJOL)

    Supplementary winter feeding and reproduction of beef heifers on Dohne sourveld. JA Erasmus, HH Barnard. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for ...

  9. Feasibility of winter cover crop production under rainfed conditions ...

    African Journals Online (AJOL)

    Low winter rainfall poses a challenge to production of high biomass from cover crops, which is necessary for the success of conservation agriculture systems in the Eastern Cape Province of South Africa. An experiment was conducted to evaluate the adaptability of white oats (Avena sativa), grazing vetch (Vicia dasycarpa), ...

  10. Effect of winter nutritional levels on subsequent growth of beef ...

    African Journals Online (AJOL)

    Effect of winter nutritional levels on subsequent growth of beef heifers in the. Highland Sourveld of Natal. A. van Niekerk* and R. Kernick. Department of Agriculture and Water Supply, Private Bag X9059, Pietermaritzburg 3200, Republic of South Africa. A.W. Lishman. Department of Animal Science, University of Natal, P.O. ...

  11. Geomagnetic Field Variation during Winter Storm at Localized ...

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... 67.52° N; 23.38° E. We have studied all the geomagnetic storms that occurred during winter season of the year 2004–2005. We observed that at Southern Hemisphere the variation is large as compared to the Northern Hemisphere. Geomagnetic field components vary when the interplanetary magnetic field ...

  12. Tebuconazole Regulates Fatty Acid Composition of Etiolated Winter Wheat Seedlings

    Directory of Open Access Journals (Sweden)

    A.V. Korsukova

    2016-05-01

    Full Text Available The fatty acid composition of shoots of unhardened and hardened to cold etiolated winter wheat seedlings grown from seeds treated with tebuconazole-based protectant «Bunker» (content of tebuconazole 60 grams per liter, g/L, and the seedlings frost resistance has been studied. It is shown that treatment of winter wheat seeds by «Bunker» preparation (1,5 microliter per gram of seeds, µl/g is accompanied by an increase of the fatty acids unsaturation in the shoots and increase of the seedlings frost resistance (–8°C, 24 h. The most pronounced decrease in the content of saturated palmitic acid and increase in the content of unsaturated α-linolenic acid were observed during cold hardening of winter wheat seedlings grown from seeds treated by tebuconazole-based protectant. It is concluded that the seeds treatment with tebuconazole-based protectant causes changes of fatty acid composition of winter wheat seedlings to increase their frost resistance.

  13. Wintering bird response to fall mowing of herbaceous buffers

    Science.gov (United States)

    Blank, P.J.; Parks, J.R.; Dively, G.P.

    2011-01-01

    Herbaceous buffers are strips of herbaceous vegetation planted between working agricultural land and streams or wetlands. Mowing is a common maintenance practice to control woody plants and noxious weeds in herbaceous buffers. Buffers enrolled in Maryland's Conservation Reserve Enhancement Program (CREP) cannot be mowed during the primary bird nesting season between 15 April and 15 August. Most mowing of buffers in Maryland occurs in late summer or fall, leaving the vegetation short until the following spring. We studied the response of wintering birds to fall mowing of buffers. We mowed one section to 10-15 cm in 13 buffers and kept another section unmowed. Ninety-two percent of birds detected in buffers were grassland or scrub-shrub species, and 98% of all birds detected were in unmowed buffers. Total bird abundance, species richness, and total avian conservation value were significantly greater in unmowed buffers, and Savannah Sparrows (Passerculus sandwichensis), Song Sparrows (Melospiza melodia), and White-throated Sparrows (Zonotrichia albicollis) were significantly more abundant in unmowed buffers. Wintering bird use of mowed buffers was less than in unmowed buffers. Leaving herbaceous buffers unmowed through winter will likely provide better habitat for wintering birds. ?? 2011 by the Wilson Ornithological Society.

  14. Changes of Winter Oilseed Rape Plant Survival During Vegetation

    Directory of Open Access Journals (Sweden)

    Balodis Oskars

    2015-07-01

    Full Text Available Winter oilseed rape (Brassica napus L. significance among field crops is unchangeable in Latvia in the last decade. Plant density of winter oilseed rape during growth period is influenced by plant development in autumn and plant wintering. The aim of four year (2008 – 2011 research in the LLU Research and Study farm “Vecauce” was to investigate the influence of agronomical factors (sowing date, sowing rate, fungicide (metkonazole application and meteorological factors on two type (line, hybrid winter oilseed rape varieties plant density changes from sowing till harvesting. Plant density in autumn, spring and during harvesting was influenced also by meteorological parameters such as air temperature and precipitation. On four year average, field germination was observed from 66% to 95%. Sowing date significantly (p0.05 influenced by fungicide as growth regulator application in autumn in any trial year. Influence of sowing date and sowing rate on the total plant density at harvest time was significant in all trial years (p<0.05 for both varieties. At higher sowing rate the plant loss during growing period was higher than at lower rates.

  15. Mangrove species' responses to winter air temperature extremes in China

    Science.gov (United States)

    Chen, Luzhen; Wang, Wenqing; Li, Qingshun Q.; Zhang, Yihui; Yang, Shengchang; Osland, Michael J.; Huang, Jinliang; Peng, Congjiao

    2017-01-01

    The global distribution and diversity of mangrove forests is greatly influenced by the frequency and intensity of winter air temperature extremes. However, our understanding of how different mangrove species respond to winter temperature extremes has been lacking because extreme freezing and chilling events are, by definition, relatively uncommon and also difficult to replicate experimentally. In this study, we investigated species-specific variation in mangrove responses to winter temperature extremes in China. In 10 sites that span a latitudinal gradient, we quantified species-specific damage and recovery following a chilling event, for mangrove species within and outside of their natural range (i.e., native and non-native species, respectively). To characterize plant stress, we measured tree defoliation and chlorophyll fluorescence approximately one month following the chilling event. To quantify recovery, we measured chlorophyll fluorescence approximately nine months after the chilling event. Our results show high variation in the geographic- and species-specific responses of mangroves to winter temperature extremes. While many species were sensitive to the chilling temperatures (e.g., Bruguiera sexangula and species in the Sonneratia and Rhizophora genera), the temperatures during this event were not cold enough to affect certain species (e.g., Kandelia obovata, Aegiceras corniculatum, Avicennia marina, and Bruguiera gymnorrhiza). As expected, non-native species were less tolerant of winter temperature extremes than native species. Interestingly, tidal inundation modulated the effects of chilling. In comparison with other temperature-controlled mangrove range limits across the world, the mangrove range limit in China is unique due to the combination of the following three factors: (1) Mangrove species diversity is comparatively high; (2) winter air temperature extremes, rather than means, are particularly intense and play an important ecological

  16. ULUDAĞ WINTER TOURISM and ITS IMPORTANCE IN THE ECONOMIC DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    Sema AY

    2016-08-01

    Full Text Available Tourism that is a regional means of development is closely related with the local economic development. Winter tourism is a set of activities and relationships composed of trips made to the regions which are located in the heart of ski sports and accordingly with slopes and snow, accommodations and other services. Since winter tourism mainly consists of a number of activities depending on snowy environments, it requires locations with certain height and slope which will also allow the execution of other nature sports such as walking, climbing etc. besides skiing and snowboarding. Uludağ, the most popular winter sports center that is 30 km away from the Bursa city center has significant natural advantages in terms of winter tourism. However, with the recently changing tourism demands in winter tourism, developments have been taking place in the types of tourism. Uludağ having natural advantages have not been able to sufficiently benefit from these advantages and cannot make use of its existing potential. Besides the countries having sucessful snow resorts of Europe such as Austria, France, Switzerland, Italy and Andorra, Romania and Bulgaria are also increasing their competitiveness in the international markets in recent years with ambitious investments. When Uludağ that is in the location of the largest snow resort in Turkey is compared with these resorts, it is thought that there is a way to go in the field of winter tourism. Starting from this idea, in the research, it is aimed to identify the contribution of Uludağ to the local economic development and the potentials for increasing this contribution. Towards the mentioned aim, the study will be carried out based on field research. In the conclusion of the study, it is planned to submit the proposals focused on policy and strategy to be followed in terms of having Uludağ use its potential in the most efficient way and provide more contribution to the local economy. In addition, its

  17. Changes in winter warming events in the Nordic Arctic Region

    Science.gov (United States)

    Vikhamar-Schuler, Dagrun; Isaksen, Ketil; Haugen, Jan Erik; Bjerke, Jarle Werner; Tømmervik, Hans

    2015-04-01

    In recent years winter warming events are frequently reported from Arctic areas. Extraordinarily warm weather episodes, occasionally combined with intense rainfall, cause severe ecological disturbance and great challenges for Arctic infrastructure. For example, the formation of ground ice due to winter rain or melting prevents reindeer from grazing, leads to vegetation browning, and impacts soil temperatures. The infrastructure may be affected by avalanches and floods resulting from intense snowmelt. The aim of our analysis is to study changes in warm spells during winter in the Nordic Arctic Region, here defined as the regions in Norway, Sweden and Finland north of the Arctic circle (66.5°N), including the Arctic islands Svalbard and Jan Mayen. Within this study area we have selected the longest available high quality observation series with daily temperature and precipitation. For studying future climate we use available regionally downscaled scenarios. We analyse three time periods: 1) the past 50-100 years, 2) the present (last 15 years, 2000-2014) and 3) the future (next 50-100 years). We define an extended winter season (October-April) and further divide it into three subseasons: 1) Early winter (October and November), 2) Mid-winter (December, January and February) and 3) Late-winter (March and April). We identify warm spells using two different classification criteria: a) days with temperature above 0°C (the melting temperature); and b) days with temperature in excess of the 90th percentile of the 1985-2014 temperature for each subseason. Both wet and dry warm spells are analysed. We compare the results for the mainland stations (maritime and inland stations) with the Arctic islands. All stations have very high frequency of warm weather events in the period 1930-1940s and for the last 15 years (2000-2014). For the most recent period the largest increase in number of warm spells are observed at the northernmost stations. We also find a continuation of this

  18. Hibernation in an antarctic fish: on ice for winter.

    Directory of Open Access Journals (Sweden)

    Hamish A Campbell

    Full Text Available Active metabolic suppression in anticipation of winter conditions has been demonstrated in species of mammals, birds, reptiles and amphibians, but not fish. This is because the reduction in metabolic rate in fish is directly proportional to the decrease in water temperature and they appear to be incapable of further suppressing their metabolic rate independently of temperature. However, the Antarctic fish (Notothenia coriiceps is unusual because it undergoes winter metabolic suppression irrespective of water temperature. We assessed the seasonal ecological strategy by monitoring swimming activity, growth, feeding and heart rate (f(H in N. coriiceps as they free-ranged within sub-zero waters. The metabolic rate of wild fish was extrapolated from f(H recordings, from oxygen consumption calibrations established in the laboratory prior to fish release. Throughout the summer months N. coriiceps spent a considerable proportion of its time foraging, resulting in a growth rate (G(w of 0.18 +/- 0.2% day(-1. In contrast, during winter much of the time was spent sedentary within a refuge and fish showed a net loss in G(w (-0.05 +/- 0.05% day(-1. Whilst inactive during winter, N. coriiceps displayed a very low f(H, reduced sensory and motor capabilities, and standard metabolic rate was one third lower than in summer. In a similar manner to other hibernating species, dormancy was interrupted with periodic arousals. These arousals, which lasted a few hours, occurred every 4-12 days. During arousal activity, f(H and metabolism increased to summer levels. This endogenous suppression and activation of metabolic processes, independent of body temperature, demonstrates that N. coriiceps were effectively 'putting themselves on ice' during winter months until food resources improved. This study demonstrates that at least some fish species can enter a dormant state similar to hibernation that is not temperature driven and presumably provides seasonal energetic

  19. Cold truths: how winter drives responses of terrestrial organisms to climate change.

    Science.gov (United States)

    Williams, Caroline M; Henry, Hugh A L; Sinclair, Brent J

    2015-02-01

    Winter is a key driver of individual performance, community composition, and ecological interactions in terrestrial habitats. Although climate change research tends to focus on performance in the growing season, climate change is also modifying winter conditions rapidly. Changes to winter temperatures, the variability of winter conditions, and winter snow cover can interact to induce cold injury, alter energy and water balance, advance or retard phenology, and modify community interactions. Species vary in their susceptibility to these winter drivers, hampering efforts to predict biological responses to climate change. Existing frameworks for predicting the impacts of climate change do not incorporate the complexity of organismal responses to winter. Here, we synthesise organismal responses to winter climate change, and use this synthesis to build a framework to predict exposure and sensitivity to negative impacts. This framework can be used to estimate the vulnerability of species to winter climate change. We describe the importance of relationships between winter conditions and performance during the growing season in determining fitness, and demonstrate how summer and winter processes are linked. Incorporating winter into current models will require concerted effort from theoreticians and empiricists, and the expansion of current growing-season studies to incorporate winter. © 2014 The Authors. Biological Reviews © 2014 Cambridge Philosophical Society.

  20. Planning of traumatological hospital resources for a major winter sporting event as illustrated by the 2005 Winter Universiad.

    Science.gov (United States)

    Oberladstaetter, J; Kamelger, F S; Rosenberger, R; Dallapozza, Ch; Struve, P; Luger, T; Fink, Ch; Attal, R

    2009-03-01

    The 22nd Student World Winter Games took place in January 2005 in Innsbruck and Seefeld, Austria. Exactly 1,500 athletes of 50 nationalities competed in 69 events in ten winter sports. A total number of 750 functionaries, 800 volunteers and 85,000 spectators participated in the second largest winter sports event behind the Olympic winter games. The aim of this study was to evaluate the needed resources to ensure traumatological care for an event of that size. At the medical "call-center" all consultations, as well as patient data, diagnosis, and medical treatment were recorded using a preset protocol. Further, all patients treated in the University Hospital Innsbruck were registered with an emphasis on trauma patients. Forty-eight of 65 patients transported to the hospital as a result of the Universiade were trauma patients, 37 of whom were athletes. The gender distribution was 34:14 (m:f). Ice hockey players had the highest rate of injury (25% of all injured athletes), followed by alpine skiers (20.8% of injured athletes). The highest ISS was nine. Forty-three patients got ambulatory treatment, five were admitted to the hospital and surgical treatment was conducted in three cases. Mean patient number was 4.8 per day. No additional personnel, structural, or technical hospital resources were needed to accommodate a large winter sports event like the Universiad. Thus, a level-B trauma center with an emergency room and independent traumatological department with around the clock surgical capability seems to be sufficient to provide traumatological care for an event of this size if the possibility of patient transport to a larger facility exists in the case of catastrophic events.

  1. Influence of Honey Bee Genotype and Wintering Method on Wintering Performance of Varroa destructor (Parasitiformes: Varroidae)-Infected Honey Bee (Hymenoptera: Apidae) Colonies in a Northern Climate.

    Science.gov (United States)

    Bahreini, Rassol; Currie, Robert W

    2015-08-01

    The objective of this study was to assess the effectiveness of a cooperative breeding program designed to enhance winter survival of honey bees (Apis mellifera L.) when exposed to high levels of varroa (Varroa destructor Anderson and Trueman) in outdoor-wintered and indoor-wintered colonies. Half of the colonies from selected and unselected stocks were randomly assigned to be treated with late autumn oxalic acid treatment or to be left untreated. Colonies were then randomly assigned to be wintered either indoors (n = 37) or outdoors (n = 40). Late autumn treatment with oxalic acid did not improve wintering performance. However, genotype of bees affected colony survival and the proportion of commercially viable colonies in spring, as indicated by greater rates of colony survival and commercially viable colonies for selected stock (43% survived and 33% were viable) in comparison to unselected stock (19% survived and 9% were viable) across all treatment groups. Indoor wintering improved spring bee population score, proportion of colonies surviving, and proportion of commercially viable colonies relative to outdoor wintering (73% of selected stock and 41% of unselected stock survived during indoor wintering). Selected stock showed better "tolerance" to varroa as the selected stock also maintained higher bee populations relative to unselected stock. However, there was no evidence of "resistance" in selected colonies (reduced mite densities). Collectively, this experiment showed that breeding can improve tolerance to varroa and this can help minimize colony loss through winter and improve colony wintering performance. Overall, colony wintering success of both genotypes of bees was better when colonies were wintered indoors than when colonies were wintered outdoors. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. Variability of Winter Air Temperature in Mid-Latitude Europe

    Science.gov (United States)

    Otterman, J.; Ardizzone, J.; Atlas, R.; Bungato, D.; Cierniewski, J.; Jusem, J. C.; Przybylak, R.; Schubert, S.; Starr, D.; Walczewski, J.

    2002-01-01

    The aim of this paper is to report extreme winter/early-spring air temperature (hereinafter temperature) anomalies in mid-latitude Europe, and to discuss the underlying forcing to these interannual fluctuations. Warm advection from the North Atlantic in late winter controls the surface-air temperature, as indicated by the substantial correlation between the speed of the surface southwesterlies over the eastern North Atlantic (quantified by a specific Index Ina) and the 2-meter level air temperatures (hereinafter Ts) over Europe, 45-60 deg N, in winter. In mid-March and subsequently, the correlation drops drastically (quite often it is negative). This change in the relationship between Ts and Ina marks a transition in the control of the surface-air temperature: absorption of insolation replaces the warm advection as the dominant control. This forcing by maritime-air advection in winter was demonstrated in a previous publication, and is re-examined here in conjunction with extreme fluctuations of temperatures in Europe. We analyze here the interannual variability at its extreme by comparing warm-winter/early-spring of 1989/90 with the opposite scenario in 1995/96. For these two December-to-March periods the differences in the monthly mean temperature in Warsaw and Torun, Poland, range above 10 C. Short-term (shorter than a month) fluctuations of the temperature are likewise very strong. We conduct pentad-by-pentad analysis of the surface-maximum air temperature (hereinafter Tmax), in a selected location, examining the dependence on Ina. The increased cloudiness and higher amounts of total precipitable water, corollary effects to the warm low-level advection. in the 1989/90 winter, enhance the positive temperature anomalies. The analysis of the ocean surface winds is based on the Special Sensor Microwave/Imager (SSM/I) dataset; ascent rates, and over land wind data are from the European Centre for Medium-Range Weather Forecasts (ECMWF); maps of 2-m temperature, cloud

  3. Proactive approach to transportation resource allocation under severe winter weather emergencies.

    Science.gov (United States)

    2012-01-01

    Severe winter weather dramatically reduces road transportation infrastructure : serviceability and decreases safety throughout Oklahoma. Although it has relatively mild winters : when compared with northern regions of the United States, Oklahoma has ...

  4. Identifying the African Wintering Grounds of Hybrid Flycatchers Using a Multi-Isotope (d

    NARCIS (Netherlands)

    Veen, T.; Hjernquist, M.B.; Van Wilgenburg, S.L.; Hobson, K.A.; Folmer, E.; Font, L.; Klaassen, M.

    2014-01-01

    Migratory routes and wintering grounds can have important fitness consequences, which can lead to divergent selection on populations or taxa differing in their migratory itinerary. Collared (Ficedula albicollis) and pied (F. hypoleuca) flycatchers breeding in Europe and wintering in different

  5. Seeking explanations for recent changes in abundance of wintering Eurasian Wigeon (Anas penelope) in northwest Europe

    DEFF Research Database (Denmark)

    Fox, Anthony David; Dalby, Lars; Christensen, Thomas Kjær

    2016-01-01

    the range. However, because over 75% of the population of over 1 million individuals winters in Belgium, the Netherlands, UK and France, there was no evidence for a major movement in the centre of gravity of the wintering distribution. Between-winter changes in overall flyway abundance were highly......We analysed annual changes in abundance of Eurasian Wigeon (Anas penelope) derived from mid-winter International Waterbird Census data throughout its northwest European flyway since 1988 using log-linear Poisson regression modelling. Increases in abundance in the north and east of the wintering...... range (Norway, Sweden, Denmark, Germany, Switzerland), stable numbers in the central range (Belgium,Netherlands,UKand France) and declining abundance in the west and south of the wintering range (Spain and Ireland) suggest a shift in wintering distribution consistent with milder winters throughout...

  6. Landscape composition influences farm management effects on farmland birds in winter: A pan-European approach

    NARCIS (Netherlands)

    Geiger, F.; Snoo, de G.R.; Berendse, F.

    2010-01-01

    This study examined the effects of agricultural intensity, various farming practices, landscape composition and vegetation cover on the abundance and species richness of wintering farmland birds, assessed simultaneously across seven European regions. The abundance and species richness of wintering

  7. Winter Community Structure Changes in Frazil Ice and Open Water in Riverine Systems

    National Research Council Canada - National Science Library

    White, K

    2004-01-01

    ...) that examined dissolved oxygen (DO) levels and changes in river microbiology during winter, periods of low water temperature, and periods of ice-cover, with the objective of providing guidance for winter water-quality modeling...

  8. Quantifying uncertainty in real time performance measurement for highway winter maintenance operations - phase 2.

    Science.gov (United States)

    2014-10-01

    Winter weather in Iowa is often unpredictable and can have an adverse impact on traffic flow. The Iowa Department of : Transportation (Iowa DOT) attempts to lessen the impact of winter weather events on traffic speeds with various proactive : mainten...

  9. Seed deterioration in flooded agricultural fields during winter

    Science.gov (United States)

    Nelms, C.O.; Twedt, D.J.

    1996-01-01

    We determined rate of seed deterioration for 3 crops (corn, rice, and soybean) and 8 weeds commonly found in agricultural fields and moist-soil management units in the Mississippi Alluvial Valley (MAV). The weeds were broadleaf signalgrass (Brachiaria platyphylla), junglerice barnyardgrass (Echinochloa colonum), morningglory (Ipomoea sp.), panic grass (Panicum sp.), bull paspalum (Paspalum boscianum), red rice (Oryza sativa), hemp sesbania (Sesbania exaltata), and bristlegrass (Setaria sp.). Weed seeds, except morningglory, deteriorated slower than corn and soybean, whereas rice decomposed slower than all weed seeds except red rice and bull paspalum. For land managers desiring to provide plant food for wintering waterfowl, rice is clearly the most persistent small grain crop in the MAV. Persistence of weed seeds under flooded conditions throughout winter makes them a cost-effective alternative to traditional crops on land managed for waterfowl.

  10. Sources of Nitrogen for Winter Wheat in Organic Cropping Systems

    DEFF Research Database (Denmark)

    Petersen, Søren O; Schjønning, Per; Olesen, Jørgen E

    2013-01-01

    mineralizable N (PMN), microbial biomass N (MBN)] were monitored during two growth periods; at one site, biomass C/N ratios were also determined. Soil for labile N analysis was shielded from N inputs during spring application to isolate cumulated system effects. Potentially mineralizable N and MBN were...... explained 76 and 82% of the variation in grain N yields in organic cropping systems in 2007 and 2008, showing significant effects of, respectively, topsoil N, depth of A horizon, cumulated inputs of N, and N applied to winter wheat in manure. Thus, soil properties and past and current management all......In organic cropping systems, legumes, cover crops (CC), residue incorporation, and manure application are used to maintain soil fertility, but the contributions of these management practices to soil nitrogen (N) supply remain obscure. We examined potential sources of N for winter wheat (Triticum...

  11. Unusually amplified summer or winter indoor levels of radon

    International Nuclear Information System (INIS)

    Gammage, R.B.; Dudney, C.S.; Wilson, D.L.

    1993-01-01

    The ratios of winter/summer indoor radon levels for houses in different regions of the southern Appalachians are characterized by individual log-normal distributions with geometric means both above and below unity. In some counties and cities, subpopulations of houses have unusually exaggerated winter/summer ratios of indoor radon, as well as high indoor radon levels, during periods of either warm or cool weather. It is proposed that in many instances, houses are communicating with larger than normal underground reservoirs of radon-bearing air in hilly karst terrains; differences between the outdoor and underground air temperatures are believed to provide density gradients producing aerostatic pressure differences for seasonally directed underground transport and subsequently elevated indoor radon. These seasonal movements of air are analogous to the well-known underground chimney effects, which produce interzonal flows of air inside caves

  12. Energy emergency planning guide: Winter 1977-78

    Energy Technology Data Exchange (ETDEWEB)

    1977-11-01

    This Energy Emergency Planning Guide for Winter, 1977-78 has been prepared in order to: identify and evaluate actions available to deal with energy emergencies this winter; provide an advance indication to the public of those actions considered most likely to be taken by the government, and provide industry, state, and local governments with suggestions about actions which they can take to deal with energy emergencies. The Guide contains specifications for over 50 standby programs and procedures, recommended implementation guidelines for using these programs keyed to a pre-emergency phase and three phases of shortfalls, and a design for an Energy Emergency Center. Flexible implementation guidelines are proposed for natural gas, petroleum, electricity/coal, and propane shortages. (MCW)

  13. Investigation of Pedestrian Comfort with Wind Chill during Winter

    Directory of Open Access Journals (Sweden)

    Hyungkeun Kim

    2018-01-01

    Full Text Available Two types of methods are used to evaluate pedestrian comfort: pedestrian wind comfort and outdoor thermal comfort. To accurately ascertain the outdoor wind environment, wind speed is the only parameter considered. However, pedestrians may still feel discomfort when the perceived temperature is low, even though the wind comfort criterion has been satisfactorily fulfilled. The purpose of this study is, therefore, to investigate pedestrian comfort when the perceived temperature is low, especially in winter conditions. To achieve this, a pedestrian survey was conducted, and 588 respondents completed a questionnaire. The results show that pedestrians feel discomfort when the WCET (Wind Chill Equivalent Temperature is low, with almost 40 percent of respondents answering that they feel discomfort in these conditions. In conclusion, the threshold wind speed of the winter season could be determined to be lower than that of the existing comfort criteria by applying the WCET.

  14. [Production of auxins by the endophytic bacteria of winter rye].

    Science.gov (United States)

    Merzaeva, O V; Shirokikh, I G

    2010-01-01

    The ability of the actinomycetes and coryneform bacteria isolated from the root tissues of winter rye to produce auxin in a liquid culture was studied. The isolates of coryneform bacteria produced indolyl-3-acetic acid (IAA) into the medium in the amount of 9.0-95.0 microg/ml and the isolates of actinomycetes in the amount of 39.5-83.0 microg/ml. The maximal IAA accumulation in culture liquid of actinomycetes coincided, in general, with the beginning of the stationary growth phase. The dependences of IAA synthesis by actinomycetes on the composition and pH of nutrient medium, tryptophan concentration, and aeration conditions were determined. Biological activity of the bacterial IAA was assessed. Treatment of winter rye seeds with coryneform auxin-producing bacteria increased the germination capacity and enhanced an intensive seedling growth in vitro.

  15. Pattern recognition analysis of polar clouds during summer and winter

    Science.gov (United States)

    Ebert, Elizabeth E.

    1992-01-01

    A pattern recognition algorithm is demonstrated which classifies eighteen surface and cloud types in high-latitude AVHRR imagery based on several spectral and textural features, then estimates the cloud properties (fractional coverage, albedo, and brightness temperature) using a hybrid histogram and spatial coherence technique. The summertime version of the algorithm uses both visible and infrared data (AVHRR channels 1-4), while the wintertime version uses only infrared data (AVHRR channels 3-5). Three days of low-resolution AVHRR imagery from the Arctic and Antarctic during January and July 1984 were analyzed for cloud type and fractional coverage. The analysis showed significant amounts of high cloudiness in the Arctic during one day in winter. The Antarctic summer scene was characterized by heavy cloud cover in the southern ocean and relatively clear conditions in the continental interior. A large region of extremely low brightness temperatures in East Antarctica during winter suggests the presence of polar stratospheric cloud.

  16. A successful forecast of an El Nino winter

    International Nuclear Information System (INIS)

    Kerr, R.A.

    1992-01-01

    This year, for the first time, weather forecasters used signs of a warming in the tropical Pacific as the basis for a long-range prediction of winter weather patterns across the United States. Now forecasters are talking about the next step: stretching the lead time for such forecasts by a year or more. That seems feasible because although this Pacific warming was unmistakable by the time forecasters at the National Weather Service's Climate Analysis Center (CAC) in Camp Springs, Maryland, issued their winter forecast, the El Nino itself had been predicted almost 2 years in advance by a computer model. Next time around, the CAC may well be listening to the modelers and predicting El Nino-related patterns of warmth and flooding seasons in advance

  17. [Morphophysiological and Behavioral Adaptations of Elk to Wintering].

    Science.gov (United States)

    Glushkov, V M; Kuznetsov, G V

    2015-01-01

    This paper studies morphometric parameters (body weight, weight of internal organs, body size, etc.) in 170 elk of various sex and age obtained in the Vyatka taiga area in winter. A number of physiological parameters (specific metabolism and thermal conductivity, heat loss rate, etc.) characterizing the metabolic rate and energy balance in the body were calculated for model animals (calf, male, and female). It is noted that in the transition from the first to the second half of winter the specific metabolism in model animals decreased from 20.6, 16.9, and 15.9 to 18.7, 15.4, and 14.5 kcal/(kg day), respectively. It is shown that changes in the rhythm of motor activity of elk are synchronized with the daily air temperature and the maximum flight distance depends on the amount of energy received by the body with food.

  18. Recrystallization and damage of ice in winter sports.

    Science.gov (United States)

    Seymour-Pierce, Alexandra; Lishman, Ben; Sammonds, Peter

    2017-02-13

    Ice samples, after sliding against a steel runner, show evidence of recrystallization and microcracking under the runner, as well as macroscopic cracking throughout the ice. The experiments that produced these ice samples are designed to be analogous to sliding in the winter sport of skeleton. Changes in the ice fabric are shown using thick and thin sections under both diffuse and polarized light. Ice drag is estimated as 40-50% of total energy dissipation in a skeleton run. The experimental results are compared with visual inspections of skeleton tracks, and to similar behaviour in rocks during sliding on earthquake faults. The results presented may be useful to athletes and designers of winter sports equipment.This article is part of the themed issue 'Microdynamics of ice'. © 2016 The Author(s).

  19. An analysis of US propane markets, winter 1996-1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-06-01

    In late summer 1996, in response to relatively low inventory levels and tight world oil markets, prices for crude oil, natural gas, and products derived from both began to increase rapidly ahead of the winter heating season. Various government and private sector forecasts indicated the potential for supply shortfalls and sharp price increases, especially in the event of unusually severe winter weather. Following a rapid runup in gasoline prices in the spring of 1996, public concerns were mounting about a possibly similar situation in heating fuels, with potentially more serious consequences. In response to these concerns, the Energy Information Administration (EIA) participated in numerous briefings and meetings with Executive Branch officials, Congressional committee members and staff, State Energy Offices, and consumers. EIA instituted a coordinated series of actions to closely monitor the situation and inform the public. This study constitutes one of those actions: an examination of propane supply, demand, and price developments and trends.

  20. Summer fallow soil management - impact on rainfed winter wheat

    DEFF Research Database (Denmark)

    Li, Fucui; Wang, Zhaohui; Dai, Jian

    2014-01-01

    Summer fallow soil management is an important approach to improve soil and crop management in dryland areas. In the Loess Plateau regions, the annual precipitation is low and varies annually and seasonally, with more than 60% concentrated in the summer months from July to September, which...... is the summer fallow period in the winter wheat-summer fallow cropping system. With bare fallow in summer as a control, a 3-year location-fixed field experiment was conducted in the Loess Plateau to investigate the effects of wheat straw retention (SR), green manure (GM) planting, and their combination on soil...... water retention (WR) during summer fallow, winter wheat yield, and crop water use and nitrogen (N) uptake. The results showed that SR increased soil WR during summer fallow by 20 mm on average compared with the control over 3 experimental years but reduced the grain yield by 8% in the third year...

  1. Black brant from Alaska staging and wintering in Japan

    Science.gov (United States)

    Derksen, Dirk V.; Bollinger, K.S.; Ward, David H.; Sedinger, J.S.; Miyabayashi, Y.

    1996-01-01

    Black brant (Branta bernicla nigricans) nest in colonies in arctic Canada, Alaska, and Russia (Derksen and Ward 1993, Sedinger et al. 1993). Virtually the entire population stages in fall at Izembek Lagoon near the tip of the Alaska Peninsula (Bellrose 1976) before southward migration (Dau 1992) to winter habitats in British Columbia, Washington, Oregon, California, and Baja California (Subcommittee on Black Brant 1992). A small number of black brant winter in Japan, Korea, and China (Owen 1980). In Japan 3,000–5,000 brant of unknown origin stop over in fall, and a declining population (in the northern islands (Brazil 1991, Miyabayashi et al. 1994). Here, we report sightings of brant in Japan that were marked in Alaska and propose a migration route based on historical and recent observations and weather patterns.

  2. Evaluation of the operation efficiency of solar panels in winter

    Science.gov (United States)

    Burakova, A. D.; Burakova, L. N.; Anisimov, I. A.; Burakova, O. D.

    2017-06-01

    The article deals with the issue of increasing the comfort and safety of life in cities by applying an alternative energy source for power supply of transport infrastructure facilities. Due to the peculiarity of the Russian Federation territory location, most cities are characterized by a long winter period, which makes it necessary to consider the features of using solar panels under these conditions. It has been established that the efficiency of solar panels depends on their type and location, the presence of snow cover on their surface, and the ambient air temperature. It has been revealed that flexible solar panels have some advantages that determine their ability to be used for power supply of transport infrastructure facilities. In the paper, the optimum angle of inclination of rigid solar panels in the winter period of the year is determined.

  3. OIT Times Newsletter: Volume 3, Number 1, Winter 2000

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, L.

    1999-12-16

    The Winter 2000 edition of the OIT Times newsletter, a quarterly publication produced by the Office of Industrial Technologies, highlights the 1999 start-up projects, announces the OIT solicitation schedule for FY2000, and features the success of the Ohio diecasting showcase. One of the quarterly highlights was Secretary Richardson's presentation of a Certificate of Partnership to Malden Mills CEO Aaron Feuerstein at the dedication of the plant's new, advanced cogeneration system.

  4. Stratospheric influence on Northern Hemisphere winter climate variability

    Science.gov (United States)

    Ouzeau, Gaelle; Douville, Herve; Saint Martin, David

    2010-05-01

    Despite significant improvements in observing and data assimilation systems, long-range dynamical forecasting remains a difficult challenge for the climate modelling community. The skill of operational seasonal forecasting systems is particularly poor in the northern extratropics where seas surface temperature (SST) has a weaker influence than in the Tropics. It is therefore relevant to look for additional potential sources of long-range climate predictability in the stratosphere using ensembles of global atmospheric simulations. Besides a control experiment where the ARPEGE-Climat model is only driven by SST, parallel simulations have been performed in which an additional control on climate variability has been accounted for through the nudging of the northern extratropical stratosphere towards the ERA40 reanalysis. Though idealized, this original experiment design allows us to compare the relative contribution of the lower and upper boundary forcings on the simulated tropospheric variability. Results show that the stratospheric nudging improves the climatology and interannual variability of the mid-latitude troposphere, especially in winter in the Northern Hemisphere. Major impacts are found in particular on the simulation of the Arctic and North Atlantic oscillations (AO and NAO). Case studies were carried out for the 1976-1977 and 1988-1989 winters, corresponding to extreme phases of the AO. Results confirm the robustness of the positive impact of the nudging, especially for winter 1976-1977 corresponding to relatively weak SST anomalies in the tropical Pacific. A sensitivity study to the model resolution shows that a well-resolved stratosphere is not necessary for the nudging to be efficient. Besides seasonal mean results, analysis of the day-to-day variability in winter allowed us to better understand the stratospheric polar vortex influence on the tropospheric circulation in the Northern Hemisphere mid-latitudes.

  5. PM10 modeling of Beijing in the winter

    Science.gov (United States)

    Song, Yu; Zhang, Minsi; Cai, Xuhui

    The megacity of Beijing, China, has had an air pollution problem since the 1990s. The concentrations of particulate matter with an aerodynamic diameter less than 10 μm (PM10) in Beijing in the winter of 2000 were high; the average value of 188 μg m -3 was nearly four times the first grade national standard of 50 μg m -3. The CALPUFF modeling system was used to simulate PM10 dispersion from 1 January 2000 to 29 February 2000. We used near real-time landcover data from the moderate resolution imaging spectroradiometer (MODIS). Statistical evaluation indicated that the model agreed well with the observations. The fluctuations of 24-h PM10 concentrations followed the winter synoptic winds. Cold air from the northwest or north intruded over Beijing for average periods of 4 days in winter, accompanied by high wind speeds. PM10 was swept out of Beijing after the cold fronts and accumulated again once the winds stopped, until the next cold air intrusion. Capital Steel Corporation Limited contributed 46% of the PM10 mass concentrations observed in the Shijingshan industrial area, and had little effect on the eastern part or the center of Beijing. The other industrial regions distributed in southeastern Beijing accounted for an average of 18% of the PM10 in Beijing. Boilers associated with coal consumption mostly for winter heating contributed 31%. Motor vehicles and road dust contributed 5% and 13%, respectively. The total of residential heating in old houses and restaurants contributed approximately 7%. The primary PM10 emissions from electrical generating units were relatively low. Some suggestions are proposed for reducing PM10 pollution in Beijing.

  6. Farmers’ Market Expands to Offer Products in Winter | Poster

    Science.gov (United States)

    By Carolynne Keenan, Contributing Writer The 2013 National Cancer Institute (NCI) at Frederick Farmers’ Market regular season may have closed, but that doesn’t mean customers who want fresh produce, handmade crafts, and other homemade goodies from local vendors are out of luck. Winter Markets, which began Jan. 7, will be held every other Tuesday, from 11 a.m. to 1 p.m., in front of Building 549 or in the Café Room, depending on the weather.

  7. Evaluation of winter temperatures on apple budbreak using grafted twigs

    Directory of Open Access Journals (Sweden)

    Fernando José Hawerroth

    2013-09-01

    Full Text Available Temperature is the main climate factor related to induction, maintenance and dormancy release in apple (Malus domestica Borkh.. The inadequate chilling exposure in apples causes budbreak problems, resulting in decrease in yield potential. Thus, the knowledge of physiological principles and environmental factors determining the dormancy phenomenon, especially winter temperature effects, it is necessary for the efficient selection of cultivars in a productive region. In addition, it is indispensable to adapt the orchard management aiming to decrease the problems caused by lack chilling during winter. The objective of this study was to evaluate the influence of different thermal conditions during the dormancy period on budbreak of apple cultivars. One-year-old twigs of 'Castel Gala' and 'Royal Gala' cultivars, grafted on M7 rootstock, were submitted to temperatures of 5, 10 and 15ºC for different exposure periods (168; 336; 672; 1,008 and 1,344 hours. After treatments execution, the plants were kept in a greenhouse at 25ºC. Budbreak was quantified when accumulated 3,444; 6,888; 10,332; 13,776; 17,220 and 20,664 GDHºC after temperature treatments. The cultivars responded differently to temperature effect during the winter period. The temperature of 15ºC during winter shows a greater effectiveness on 'Castel Gala' apple budbreak while in the 'Royal Gala' apples the temperatures of 5 and 10ºC show better performance. 'Castel Gala' cultivar (low chilling requirement may supply its physiological necessities, may be capable to budburst, even when subjected to higher temperatures in relation to 'Royal Gala' apples (high chilling requirement.

  8. Winter School on Mirror Symmetry, Vector Bundles and Lagrangian Submanifolds

    CERN Document Server

    Yau, S-T

    2002-01-01

    The collection of articles in this volume are based on lectures presented during the Winter School on Mirror Symmetry held at Harvard University. There are many new directions suggested by mirror symmetry which could potentially have very rich connections in physics and mathematics. This book brings together the latest research in a major area of mathematical physics, including the recent progress in mirror manifolds and Lagrangian submanifolds. In particular, several articles describing homological approach and related topics are included.

  9. Twentieth Century Winter Changes in Southern Hemisphere Synoptic Weather Modes

    OpenAIRE

    Frederiksen, Jorgen S.; Frederiksen, Carsten S.

    2011-01-01

    During the last sixty years, there have been large changes in the southern hemisphere winter circulation and reductions in rainfall particularly in the southern Australian region. Here we examine the corresponding changes in dynamical modes of variability ranging from storm tracks, onset-of-blocking modes, northwest cloud-band disturbances, Antarctic low-frequency modes, intraseasonal oscillations, and African easterly waves. Our study is performed using a global two-level primitive equation ...

  10. Naval War College Review. Volume 61, Number 1, Winter 2008

    Science.gov (United States)

    2008-01-01

    years in France at the Paris Institute of Political Science. He also holds mas- ter’s degrees in public administration (finance) from Harvard and in...Mari- time Strategy. Spring 2007:17–26 Barnett, Roger W. Strategic Culture and Its Relationship to Naval Strategy. Winter 2007: 24–34 Bollinger ...It Take to Make a Thousand-Ship Navy? Autumn 2007:135–37 History—Naval and Maritime Bollinger , Marty. Did a Soviet Merchant Ship Encounter the Pearl

  11. The effects of changes in snow depth on winter recreation

    Czech Academy of Sciences Publication Activity Database

    Zahradníček, Pavel; Rožnovský, J.; Štěpánek, Petr; Farda, Aleš; Brzezina, J.

    2016-01-01

    Roč. 7, č. 1 (2016), s. 44-54 ISSN 1804-2821 R&D Projects: GA MŠk(CZ) LO1415; GA ČR GA13-04291S; GA ČR(CZ) GA14-12262S Institutional support: RVO:67179843 Keywords : new snow * total snow depth * climate change * climate models * winter recreations Subject RIV: EH - Ecology, Behaviour

  12. The long darkness: Psychological and moral perspectives on nuclear winter

    International Nuclear Information System (INIS)

    Grinspoon, L.

    1986-01-01

    The aftermath of nuclear war - a sustained period of devastation called nuclear winter - would threaten the survival of civilization, even of the human species. In this book some opponents of the arms race describe the consequences of nuclear warfare and offer explanations - drawn from their knowledge of psychiatry, history, religion, and biology - for the irrational behavior of political leaders who risk these consequences and for the reluctance of ordinary citizens to face the horror of the nuclear threat

  13. Factors affecting food choices by birds in winter

    OpenAIRE

    Korencová, Petra

    2010-01-01

    I studied food choices of four small passerine species in winter on an artifical source of food, a bird feeder. I did experiments with two different types of food. I proposed that birds would prefer the type of food with higher contain of fat and calories. Food preferences were shown, but independently on calories contain. Greenfinches always selected sunflower seeds. I conclude, this species is affected by tradition, because it is usually fed by sunflower seeds in all bird feeders in vicinit...

  14. Mapping wintering waterfowl distributions using weather surveillance radar.

    Science.gov (United States)

    Buler, Jeffrey J; Randall, Lori A; Fleskes, Joseph P; Barrow, Wylie C; Bogart, Tianna; Kluver, Daria

    2012-01-01

    The current network of weather surveillance radars within the United States readily detects flying birds and has proven to be a useful remote-sensing tool for ornithological study. Radar reflectivity measures serve as an index to bird density and have been used to quantitatively map landbird distributions during migratory stopover by sampling birds aloft at the onset of nocturnal migratory flights. Our objective was to further develop and validate a similar approach for mapping wintering waterfowl distributions using weather surveillance radar observations at the onset of evening flights. We evaluated data from the Sacramento, CA radar (KDAX) during winters 1998-1999 and 1999-2000. We determined an optimal sampling time by evaluating the accuracy and precision of radar observations at different times during the onset of evening flight relative to observed diurnal distributions of radio-marked birds on the ground. The mean time of evening flight initiation occurred 23 min after sunset with the strongest correlations between reflectivity and waterfowl density on the ground occurring almost immediately after flight initiation. Radar measures became more spatially homogeneous as evening flight progressed because birds dispersed from their departure locations. Radars effectively detected birds to a mean maximum range of 83 km during the first 20 min of evening flight. Using a sun elevation angle of -5° (28 min after sunset) as our optimal sampling time, we validated our approach using KDAX data and additional data from the Beale Air Force Base, CA (KBBX) radar during winter 1998-1999. Bias-adjusted radar reflectivity of waterfowl aloft was positively related to the observed diurnal density of radio-marked waterfowl locations on the ground. Thus, weather radars provide accurate measures of relative wintering waterfowl density that can be used to comprehensively map their distributions over large spatial extents.

  15. The injury experience at the 2010 winter paralympic games.

    Science.gov (United States)

    Webborn, Nick; Willick, Stuart; Emery, Carolyn A

    2012-01-01

    The objective of this study was to examine incidence proportion and the characteristics of athlete injuries sustained during the 2010 Vancouver Paralympic Games. Descriptive epidemiological study. All medical venues at the 2010 Vancouver Paralympic Games, Canada. A total of 505 athletes from 44 National Paralympic Committees participating in the 2010 Vancouver Winter Paralympic Games. Baseline covariates included sport specificity (ie, ice sledge hockey, alpine skiing, Nordic skiing, wheelchair curling), gender, age, and disability classification. All injuries that occurred during the 2010 Vancouver Paralympic Games. "Injury" was defined as any sport-related musculoskeletal complaint that caused the athlete to seek medical attention during the study period, regardless of the athlete's ability to continue with training or competition. The Injury Surveillance System identified a total of 120 injuries among 505 athletes [incidence proportion = 23.8% (95% confidence interval, 20.11-27.7)] participating in the 2010 Winter Paralympic Games. There was a similar injury incidence proportion among male (22.8%) and female (26.6%) athletes [incidence rate ratio = 1.1 (95% confidence interval, 0.7-1.7)]. Medical encounters for musculoskeletal complaints were generated in 34% of all sledge hockey athletes, 22% of alpine ski racers, 19% of Nordic skiers, and 18% of wheelchair curling athletes. The Injury Surveillance System identified sport injuries in 24% of all athletes participating in the 2010 Winter Paralympic Games. The injury risk was significantly higher than during the 2002 (9.4%) and 2006 (8.4%) Winter Paralympic Games. This may reflect improved data collection systems but also highlights the high risk of acute injury in alpine skiing and ice sledge hockey at Paralympic Games. These data will assist future Organizing Committees with the delivery of medical care to athletes with a disability and guide future injury prevention research.

  16. Naval War College Review. Volume 62, Number 1, Winter 2009

    Science.gov (United States)

    2009-01-01

    Africa and its constituent nations and people than the United States has customarily brought to bear on policy. This vision must be couched in reality...The Man Who Invented the Pacific War (London: Mac - donald, 1990). 1 4 0 N A V A L W A R C O L L E G E R E V I E W T:\\Academic\\NWC Review\\Winter 2009

  17. Hellsgate Winter Range : Wildlife Mitigation Project. Preliminary Environmental Assessment.

    Energy Technology Data Exchange (ETDEWEB)

    United States. Bonneville Power Administration.

    1995-01-01

    The Bonneville Power Administration proposes funding the Hellsgate Winter Range Wildlife Mitigation Project in cooperation with the Colville Convederated Tribes and Bureau of Indian Affairs. This Preliminary Environmental Assessment examines the potential environmental effects of acquiring and managing property for wildlife and wildlife habitat within a large project area. The Propose action is intended to meet the need for mitigation of wildlife and wild life habitat that was adversely affected by the construction of Grand Coulee and Chief Joseph Dams and their reservoirs.

  18. Interdecadal variability of winter precipitation in Southeast China

    OpenAIRE

    Zhang, L.; Zhu, X.; Fraedrich, K.; Sielmann, F.; Zhi, X.

    2014-01-01

    Interdecadal variability of observed winter precipitation in Southeast China (1961–2010) is characterized by the first empirical orthogonal function of the three-monthly Standardized Precipitation Index (SPI) subjected to a 9-year running mean. For interdecadal time scales the dominating spatial modes represent monopole features involving the Arctic Oscillation (AO) and the sea surface temperature (SST) anomalies. Dynamic composite analysis (based on NCEP/NCAR reanalyzes) reveals the followin...

  19. Winter: Public Enemy #1 for Accessibility EXPLORING NEW SOLUTIONS

    Directory of Open Access Journals (Sweden)

    Ernesto Morales

    2014-05-01

    Full Text Available Abstract: Winter is expensive. For countries situated in the northern hemisphere, closer to the north pole, such as Canada, Russia and Scandinavia, winter requires the acquisition of special clothing, car tires, and sports equipment, snow removal or plowing from the streets, and is associated with the presence of ice patches, along with accidents and illnesses associated with cold weather. Fall-related injuries due to winter conditions have been estimated to cost the Canadian health care system $ 2.8 billion a year. However, the greatest cost snow entails every year is the social isolation of seniors as well as wheelchair and walker users. This results from the lack of accessibility, as it is difficult to circulate on snow-covered streets even for the able-bodied. Social isolation has been associated with other negative consequences such as depression and even suicide. This exploratory pilot study aimed at finding possible and feasible design solutions for improving the accessibility of sidewalks during winter conditions. For this project we used a Co-Design methodology. Stakeholders (City of Quebec representatives, designers, urban planners, occupational therapists, and adults with motor, visual and aural disabilities were invited to participate in the design process. In order to meet the objectives, two main steps were carried out: 1. Conception of the design solutions (through Co-design sessions in a Focus-group format with seniors, designers and researchers; and 2. Validation of the design solutions (consultation with experts and stakeholders. The results are a wide variety of possible and feasible solutions, including the reorganisation of the snow-removal procedure and the development of heated curb cuts. This project was funded by the City of Quebec in partnership with the Centre interdisciplinaire de recherche en réadaptation et intégration sociale (CIRRIS. Ultimately, the project sought to explore possible solutions to be implemented

  20. Remote Diagnosis of Nitrogen Status in Winter Oilseed Rape

    Science.gov (United States)

    Liu, S.

    2016-12-01

    Winter oilseed rape is one of the most important oilseed crops in the world. Compared with cereal crops, it requires high amount of nitrogen (N) supplies, but it is also characterized by low N use efficiency. The N nutrition index (NNI), defined as the ratio of the actual plant N concentration (PNC) to the critical PNC at a given biomass level, has been widely used to diagnose plant N status and to aid optimizing N fertilization. But traditional techniques to determine NNI in the lab are time-consuming and expensive. Remote sensing provides a promising approach for large-scale and rapid monitoring and diagnosis of crop N status. In this study, we conducted the experiment in the winter oilseed rape field with eight fertilization treatments in the growing season of 2014 and 2015. PNC, dry mass, and canopy spectra were measured during the different growth stages of winter oilseed rape. The N dilution curve was developed with measurements, and NNI was computed and analyzed for different treatments and different growth stage. For the same treatment, NNI decreased as more leaves were developing. Two methods were applied to remotely estimating NNI for winter oilseed rape: (1) NNI was estimated directly with vegetation indices (VIs) derived from canopy spectra; (2) the actual PNC and the critical PNC at the given biomass level were estimated separately with different types of VIs, and NNI was then computed with the two parts of the estimations. We found that VIs based solely on bands in the visible region provided the most accurate estimates of PNC. Estimating NNI directly with VIs had better performance than estimating the actual PNC and the critical PNC separately.