Sample records for increased winter snowfall

  1. Impact of declining Arctic sea ice on winter snowfall

    PubMed Central

    Liu, Jiping; Curry, Judith A.; Wang, Huijun; Song, Mirong; Horton, Radley M.

    2012-01-01

    While the Arctic region has been warming strongly in recent decades, anomalously large snowfall in recent winters has affected large parts of North America, Europe, and east Asia. Here we demonstrate that the decrease in autumn Arctic sea ice area is linked to changes in the winter Northern Hemisphere atmospheric circulation that have some resemblance to the negative phase of the winter Arctic oscillation. However, the atmospheric circulation change linked to the reduction of sea ice shows much broader meridional meanders in midlatitudes and clearly different interannual variability than the classical Arctic oscillation. This circulation change results in more frequent episodes of blocking patterns that lead to increased cold surges over large parts of northern continents. Moreover, the increase in atmospheric water vapor content in the Arctic region during late autumn and winter driven locally by the reduction of sea ice provides enhanced moisture sources, supporting increased heavy snowfall in Europe during early winter and the northeastern and midwestern United States during winter. We conclude that the recent decline of Arctic sea ice has played a critical role in recent cold and snowy winters. PMID:22371563

  2. 21st century projections of snowfall and winter severity across central-eastern North America

    NASA Astrophysics Data System (ADS)

    Notaro, M.; Lorenz, D. J.; Hoving, C.; Schummer, M.

    2014-12-01

    Statistically downscaled climate projections from nine global climate models (GCMs) are used to force a snow accumulation and ablation model (SNOW-17) across the central-eastern North American Landscape Conservation Cooperatives (LCCs) to develop high-resolution projections of snowfall, snow depth, and winter severity index (WSI) by the mid- and late 21st century. Here, we use projections of a cumulative WSI (CWSI) known to influence autumn-winter waterfowl migration to demonstrate the utility of SNOW-17 results. The application of statistically downscaled climate data and a snow model leads to a better representation of lake processes in the Great Lakes Basin, topographic effects in the Appalachian Mountains, and spatial patterns of climatological snowfall, compared to the original GCMs. Annual mean snowfall is simulated to decline across the region, particularly in early winter (December-January), leading to a delay in the mean onset of the snow season. Due to a warming-induced acceleration of snowmelt, the percentage loss in snow depth exceeds that of snowfall. Across the Plains and Prairie Potholes LCC and Upper Midwest and Great Lakes LCC, daily snowfall events are projected to become less common, but more intense. The greatest reductions in the number of days per year with a present snowpack are expected close to the historical position of the -5°C isotherm in DJFM, around 44°N. The CWSI is projected to decline substantially during December-January, leading to increased likelihood of delays in timing and intensity of autumn-winter waterfowl migrations.

  3. Winter Snowfall Turns an Emerald White

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Ireland's climate is normally mild due to the nearby Gulf Stream, but the waning days of 2000 saw the Emerald Isle's green fields swathed in an uncommon blanket of white. The contrast between summer and winter is apparent in this pair of images of southwestern Ireland acquired by MISR's vertical-viewing (nadir) camera on August 23, 2000 (left) and December 29, 2000 (right). The corresponding Terra orbit numbers are 3628 and 5492, respectively.

    The year 2000 brought record-breaking weather to the British Isles. England and Wales experienced the wettest spring and autumn months since 1766. Despite being one of the warmest years in recent history, a cold snap arrived between Christmas and New Year's Day. According to the UK Meteorological Office, the 18 centimeters (7 inches) of snow recorded at Aldergrove, Northern Ireland, on December 27-28 was the deepest daily fall since 1930.

    Prominent geographical features visible in the MISR images include Galway Bay near the top left. Further south, the mouth of the River Shannon, the largest river in the British Isles, meets the Atlantic Ocean. In the lower portions of the images are the counties of Limerick, Kerry and Cork.

    MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology

  4. Lunch Brie ng The winter of 2009-2010 broke snowfall accumulation and extreme cold records in cities and rural communities

    E-print Network

    ­ Lunch Brie ng ­ The winter of 2009-2010 broke snowfall accumulation and extreme cold records.S. is not the only nation experiencing harsh winters. Europe saw unprecedented snowfalls and record cold temperatures Geophysical Union (AGU), and the Weather Coalition. These sponsoring groups share in common a dedication

  5. Creating a United States Snowfall Regionalization Based on Frequency

    NASA Astrophysics Data System (ADS)

    Kluver, D.

    2014-12-01

    A snowfall regionalization is developed for the conterminous United States using variability of snowfall frequency. Principal components analysis and cluster analysis are used to group stations together over the time period 1930 to 2007. Seven snowfall regions are identified, which correspond to predominant storm tracks across the United States. These are: the southeast, the south central Plains and southwest, the Ohio River Valley and mid-Atlantic, the Pacific Northwest, and three sub-regions in the Upper-Midwest. Quantile regression is used to identify how the frequency distributions at each region change over the period of record. The Pacific Northwest and southeastern regions are experiencing significant declines in median and large frequency winters. The Northern part of the upper-Midwest region is experiencing significant increasing trends in all percentiles of snowfall frequencies.

  6. Snowfall Retrivals Using a Video Disdrometer

    NASA Astrophysics Data System (ADS)

    Newman, A. J.; Kucera, P. A.

    2004-12-01

    A video disdrometer has been recently developed at NASA/Wallops Flight Facility in an effort to improve surface precipitation measurements. One of the goals of the upcoming Global Precipitation Measurement (GPM) mission is to provide improved satellite-based measurements of snowfall in mid-latitudes. Also, with the planned dual-polarization upgrade of US National Weather Service weather radars, there is potential for significant improvements in radar-based estimates of snowfall. The video disdrometer, referred to as the Rain Imaging System (RIS), was deployed in Eastern North Dakota during the 2003-2004 winter season to measure size distributions, precipitation rate, and density estimates of snowfall. The RIS uses CCD grayscale video camera with a zoom lens to observe hydrometers in a sample volume located 2 meters from end of the lens and approximately 1.5 meters away from an independent light source. The design of the RIS may eliminate sampling errors from wind flow around the instrument. The RIS operated almost continuously in the adverse conditions often observed in the Northern Plains. Preliminary analysis of an extended winter snowstorm has shown encouraging results. The RIS was able to provide crystal habit information, variability of particle size distributions for the lifecycle of the storm, snowfall rates, and estimates of snow density. Comparisons with coincident snow core samples and measurements from the nearby NWS Forecast Office indicate the RIS provides reasonable snowfall measurements. WSR-88D radar observations over the RIS were used to generate a snowfall-reflectivity relationship from the storm. These results along with several other cases will be shown during the presentation.

  7. A Snowfall Impact Scale Derived from Northeast Storm Snowfall Distributions

    Microsoft Academic Search

    Paul J. Kocin; Louis W. Uccellini

    2004-01-01

    A Northeast snowfall impact scale (NESIS) is presented to convey a measure of the impact of heavy snowfall in the Northeast urban corridor, a region that extends from southern Virginia to New England. The scale is derived from a synoptic climatology of 30 major snowstorms in the Northeast urban corridor and applied to the snowfall distribution of 70 snowstorms east

  8. Sensitivity Experiments on the Orographic Snowfall over the Mountainous Region of Northern Japan

    Microsoft Academic Search

    Kazuo Saito; Masataka MURAKAMI; Takayo Matsuo; Hakaru Mizuno

    1996-01-01

    Numerical experiments on the orographic snowfall over the mountainous region of northern Japan in winter are conducted using a 2-dimensional non-hydrostatic model with a cloud microphysical parameterization which predicts not only the mixing ratio of water species but also the number density of ice species. The orographic effect on the snowfall is investigated by sensitivity tests from cloud microphysical aspects.

  9. Future snowfall in western and central Europe projected with a high-resolution regional climate model ensemble

    NASA Astrophysics Data System (ADS)

    Vries, Hylke; Lenderink, Geert; Meijgaard, Erik

    2014-06-01

    Snowfall frequency and intensity are influenced strongly by climate change. Here we separate the basic frequency change resulting from a gradually warming climate, from the intensity changes, by focusing on snowfall on days where the mean temperature is below freezing (Hellmann days). Using an ensemble of simulations, obtained with the high-resolution regional climate model KNMI-RACMO2 driven by the EC-EARTH global climate model and RCP4.5 and RCP8.5 forcing scenarios, we show that in addition to the strong decrease in the number of Hellmann days, also a substantial reduction in the mean Hellmann-day snowfall can be expected over large parts of western and central Europe. Moreover, seasonal snowfall extremes display trends that are comparable or even larger. Projected intensity reductions are locally as large as -30% per degree warming, thus being in sharp contrast to mean winter precipitation, which increases in most future climate scenarios. Exceptions are the high Alps and parts of Scandinavia, which may see an increase of up to +10% per degree warming.

  10. Measuring Snowfall with Solar Panels

    USGS Multimedia Gallery

    Using the device pictured here, government scientists are measuring snowfall in remote areas with a bucket, a small windmill, and the sun -- all the while saving money, energy, and ultimately helping to save lives. ...

  11. Unusually cold and dry winters increase mortality in Australia.

    PubMed

    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. PMID:25460613

  12. Increasing Sun Protection in Winter Outdoor Recreation

    PubMed Central

    Walkosz, Barbara J.; Buller, David B.; Andersen, Peter A.; Scott, Michael D.; Dignan, Mark B.; Cutter, Gary R.; Maloy, Julie A.

    2009-01-01

    Background Unprotected and excessive exposure to ultraviolet radiation (UVR) is the primary risk factor for skin cancer. Design A pair-matched, group-randomized, pre-test/post-test, quasi-experimental design, with ski resorts as the unit of randomization, tested the effectiveness of Go Sun Smart, a multi-channel skin cancer prevention program. Independent samples of guests were taken at baseline (2001) and follow-up (2002); data were analyzed in 2006. Setting and Participants A total of 6516 adult guests at 26 ski resorts in the western U.S. and Canada were recruited, consented, and interviewed on chairlifts. This study was nested within an occupational intervention for ski resort workers. Intervention Ski resorts were pair-matched and randomized to receive Go Sun Smart, which consisted of print, electronic, visual, and interpersonal skin cancer prevention messages. Main Outcome Measures Sun-protection behaviors, sunburning, recall of sun-protection messages, and the association of message exposure to sun protection. Results The difference in recall of all sun-protection messages, messages on signs and posters, and the Go Sun Smart logo was significant between the intervention and control resorts. Reported use of sun-protection practices was higher by guests at intervention ski areas using more (a higher dose of) Go Sun Smart materials. Intervention-group guests who recalled a sun-safety message were more likely to practice sun safety than intervention-group guests who did not recall a message and control-group guests. Conclusions While the mere implementation of Go Sun Smart did not produce sun-safety improvements, Go Sun Smart appeared to be effective for guests who encountered and remembered it. Many factors can work against message exposure. Signage seemed to produce the greatest increase in exposure to sun-safety messages. PMID:18471586

  13. A Snowfall Impact Scale Derived from Northeast Storm Snowfall Distributions.

    NASA Astrophysics Data System (ADS)

    Kocin, Paul J.; Uccellini, Louis W.

    2004-02-01

    A Northeast snowfall impact scale (NESIS) is presented to convey a measure of the impact of heavy snowfall in the Northeast urban corridor, a region that extends from southern Virginia to New England. The scale is derived from a synoptic climatology of 30 major snowstorms in the Northeast urban corridor and applied to the snowfall distribution of 70 snowstorms east of the Rocky Mountains. NESIS is similar in concept to other meteorological scales that are designed to simplify complex phenomena into an easily understood range of values. The Fujita scale for tornadoes and the Saffir Simpson scale for hurricanes measure the potential for destruction to property and loss of life by wind-related damage (and storm surge for Saffir Simpson) through use of a categorical ranking (0 or 1 5).

  14. Improving Radar Snowfall Measurements Using a Video Disdrometer

    NASA Astrophysics Data System (ADS)

    Newman, A. J.; Kucera, P. A.

    2005-05-01

    A video disdrometer has been recently developed at NASA/Wallops Flight Facility in an effort to improve surface precipitation measurements. The recent upgrade of the UND C-band weather radar to dual-polarimetric capabilities along with the development of the UND Glacial Ridge intensive atmospheric observation site has presented a valuable opportunity to attempt to improve radar estimates of snowfall. The video disdrometer, referred to as the Rain Imaging System (RIS), has been deployed at the Glacial Ridge site for most of the 2004-2005 winter season to measure size distributions, precipitation rate, and density estimates of snowfall. The RIS uses CCD grayscale video camera with a zoom lens to observe hydrometers in a sample volume located 2 meters from end of the lens and approximately 1.5 meters away from an independent light source. The design of the RIS may eliminate sampling errors from wind flow around the instrument. The RIS has proven its ability to operate continuously in the adverse conditions often observed in the Northern Plains. The RIS is able to provide crystal habit information, variability of particle size distributions for the lifecycle of the storm, snowfall rates, and estimates of snow density. This information, in conjunction with hand measurements of density and crystal habit, will be used to build a database for comparisons with polarimetric data from the UND radar. This database will serve as the basis for improving snowfall estimates using polarimetric radar observations. Preliminary results from several case studies will be presented.

  15. Perennial Forage Kochia for Increased Production of Winter Grazed Pastures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grazing forage kochia (Kochia prostrata) during fall/winter has improved livestock health and reduced winter feeding costs. The objectives of this study were to compare forage production/quality and livestock performance of traditional winter pastures versus pastures with forage kochia. Two kochia...

  16. Effects of extraordinary snowfall on traffic safety.

    PubMed

    Seeherman, Joshua; Liu, Yi

    2015-08-01

    Snowfall affects traffic safety by causing changes in roadway surface and visibility that result in crashes, spinouts, and breakdowns. Using data collected at a site that regularly receives nearly 1000cm of snow during the snow season, this study examines the impact of snowfall quantity, gap between snow events, and weather conditions on crash and incident frequencies. Estimation results from regression analysis show that snowfall severity significantly impacts crashes and incidents but the impact diminishes marginally with each additional centimeter of snow. Gap has a significant fixed effect on crashes but its impact on incidents varies significantly across observations. The effect of the mixed precipitation condition is smaller in comparison to an all-snow condition. These results will help inform policy for snow removal and traffic enforcement in areas of high snowfall. PMID:26024836

  17. Measuring Snowfall From Satellite Microwave Observations

    NASA Astrophysics Data System (ADS)

    Liu, G.

    2014-12-01

    Snowfall is one of the important components in the global hydrological cycle. However, snowfall retrieval from satellite observations is very difficult (compared to rainfall retrieval) because of several reasons including weak radiative signal, surface contamination, cloud liquid water masking, etc. Several satellite sensors currently in operation are potentially capable of detecting and estimating snowfall, for example, cloud radar onboard CloudSat and high frequency microwave radiometers (SSMIS, MHS, GMI) on NOAA, MetOP, S-NPP, DMSP and GPM satellites. In this paper, we report our research results on how to best use these sensors to extract snowfall information. Specifically, we (1) studied the global snowfall frequency and rate distributions based on multiple years of CloudSat observations; (2) investigated the optimal channel selection for snowfall retrieval using collocated satellite SSMIS (19-183 GHz) and ground radar (NMQ) data; (3) developed a retrieval algorithm in which radar data (CloudSat and/or NMQ) are used as truth to train high-frequency passive microwave data and use high-frequency passive microwave data to broaden spatial and temporal coverage. Finally, retrievals based on observations from several satellites are compared with each other and compared with surface observations.

  18. An indoor public space for a winter city

    E-print Network

    Crane, Justin Fuller

    2005-01-01

    Winter is a marginalized season in North American design. Even though most cities in the northern United States and Canada have winter conditions-snowfall, ice, freezing temperatures, and long nights-for substantial portions ...

  19. Lake-Effect Snowfall over Lake Michigan.

    NASA Astrophysics Data System (ADS)

    Braham, Roscoe R., Jr.; Dungey, Maureen J.

    1995-05-01

    Aircraft measurements of snow particle size spectra from 36 flights on 26 snowy days are used to estimate snow precipitation rates over Lake Michigan. Results show that average rates during 14 wind-parallel-type lake-effect storms increased from the upwind shore to about midlake and then were essentially uniform (1.5 2 mm day1, liquid water equivalent) to the downwind shore. Snow from midlake bands and shoreline bands maximized over the lake. The position of the maximum during these types of lake-effect storms depends on meteorological conditions. In any given case it may be near either shore or anywhere between them. This study combines 12 cases of midlake and shoreline bands. The resulting cross-lake snow profile shows a broad maximum reaching over 4 mm day1 near midlake. The single sample maximum snow precipitation rate encountered in this study was 77.7 mm day1. The average cross-lake profile from combining 26 cases of lake-effect storms shows that snowfall into the lake is considerably greater than one would expect from a linear interpolation between values measured along either shore.An attempt is made to estimate the average increase in snow over lake Michigan resulting from combined lake-effect and large-scale cyclonic storms. The result is interesting but not considered very reliable because it depends upon the relative frequencies of different types of lake-effect storms as well as overtake snow rates from large-scale cyclonic storms; neither is well known.

  20. The 8th-10 th January 2009 snowfalls: a case of Mediterranean warm advection event

    NASA Astrophysics Data System (ADS)

    Aguado, F.; Ayensa, E.; Barriga, M.; Del Hoyo, J.; Fernández, A.; Garrido, N.; Martín, A.; Martín, F.; Roa, I. Martínez, A.; Pascual, R.

    2009-09-01

    From 8 th to 10 th of January 2009, significant snowfalls were reported in many areas of the Iberian Peninsula and the Balearic Islands. This relevant event was very important from the meteorological and social impact point of views. The snow affected many zones, especially the regions of Madrid, Castilla & León and Castilla-La Mancha (Spanish central plateau) with the persistence and thickness of solid precipitation. Up to twenty-five centimetres of snow were reported in some places. On 9th of January the snowfalls caused great social and media impact due to the fact that they took place in the early hours in the Madrid metropolitan areas, affecting both air traffic and land transport. The "Madrid-Barajas" airport was closed and the city was collapsed during several hours. A study of this situation appears in the poster. The snowstorm was characterized by the previous irruption of an European continental polar air mass, that subsequently interacted with a wet and warm air mass of Mediterranean origin, all preceded by low level easterly flows. This type of snowfall is called "warm advection". These winter situations are very efficient from precipitation point of view, generating significant snowfalls and affecting a lot of areas.

  1. Snowfall and avalanche synchronization: beyond observational statistics

    NASA Astrophysics Data System (ADS)

    Crouzy, Benoît; Forclaz, Romain; Sovilla, Betty; Corripio, Javier; Perona, Paolo

    2015-04-01

    We present a methodology for quantifying the synchronization between snowfall and avalanches in relation to slope and terrain properties at the detachment zone. Focusing on a particular field situation (SLF study site, Vallée de la Sionne, Valais, Switzerland), we present a dataset consisting of 549 avalanche events and use a stochastic framework (Perona et al., Proceedings of the Royal Society A, 2012) for capturing the avalanche statistics with a minimal number of ingredients. Over the observation period (7 years), meteorological data was collected and pictures of the slope were taken every 30 minutes. For the avalanche events, slope, aspect, coordinates and altitude of the detachment zone are available from georeferenced images, and the timing of the events can be obtained from selecting the images before and after avalanche events. All model parameters can directly be computed from meteorological data (snow depth evolution), except for one parameter: the state-dependent avalanche release rate, which aggregates the influence of slope and terrain properties. From the timing distribution of the precipitation events and of the avalanche events, we calibrate the model and fix the value of the missing parameter by maximizing the likelihood of the field observations, conditional to the value of the model parameter. We carefully discuss confidence intervals for our parameter estimation. The calibrated model allows us to obtain statistical properties of the avalanches in our study site, beyond observational statistics. We compute the synchronization between snowfall and avalanches for low and high slopes, which in turn allows us to derive the return period of avalanche events (dependent and independent on the release depth). We obtain the critical event magnitude above which the return period of avalanche events with release depth h* is shorter than the return period of snowfall with equal deposited snow depth h*. Finally, using the concept of information entropy, we quantify the uncertainty in predicting the occurrence of an avalanche from the observation of snowfall.

  2. Snowfall in the Himalayas: an uncertain future from a little-known past

    NASA Astrophysics Data System (ADS)

    Viste, E.; Sorteberg, A.; Renssen, H.

    2015-06-01

    Snow and ice provide large amounts of meltwater to the Indus, Ganges and Brahmaputra rivers. This study combines present-day observations and reanalysis data with climate model projections to estimate the amount of snow falling over the basins today and in the last decades of the 21st century. Estimates of present-day snowfall based on a combination of temperature and precipitation from reanalysis data and observations vary by factors of 2-4. The spread is large, not just between the reanalysis and the observations but also between the different observational data sets. With the strongest anthropogenic forcing scenario (RCP8.5), the climate models project reductions in annual snowfall by 30-50% in the Indus Basin, 50-60% in the Ganges Basin and 50-70% in the Brahmaputra Basin by 2071-2100. The reduction is due to increasing temperatures, as the mean of the models show constant or increasing precipitation throughout the year in most of the region. With the strongest anthropogenic forcing scenario, the mean elevation where rain changes to snow - the rain/snow line - creeps upward by 400-900 m, in most of the region by 700-900 meters. The largest relative change in snowfall is seen in the upper westernmost sub-basins of the Brahmaputra. With the strongest forcing scenario, most of this region will have temperatures above freezing, especially in the summer. The projected reduction in annual snowfall is 65-75%. In the upper Indus, the effect of a warmer climate on snowfall is less extreme, as most of the terrain is high enough to have temperatures sufficiently far below freezing today. A 20-40% reduction in annual snowfall is projected.

  3. Characteristics of easterly-induced snowfall in Yeongdong and its relationship to air-sea temperature difference

    NASA Astrophysics Data System (ADS)

    Nam, Hyoung-Gu; Kim, Byung-Gon; Han, Sang-Ok; Lee, Chulkyu; Lee, Seoung-Soo

    2014-08-01

    Characteristics of snowfall episodes have been investigated for the past ten years in order to study its association with lowlevel stability and air-sea temperature difference over the East Sea. In general, the selected snowfall episodes have similar synoptic setting such as the Siberian High extended to northern Japan along with the Low passing by the southern Korean Peninsula, eventually resulting in the easterly flow in the Yeongdong region. Especially in the heavy snowfall episodes, convective unstable layers have been identified over the East sea due to relatively warm sea surface temperature (SST) about 8˜10°C and specifically cold pool around 1˜2 km above the surface level (ASL), which can be derived from Regional Data Assimilation and Prediction System (RDAPS), but that have not been clearly exhibited in the weak snowfall episodes. The basic mechanism to initiate snowfall around Yeongdong seems to be similar to that of lake-effect snowstorms around Great Lakes in the United States (Kristovich et al., 2003). Difference of equivalent potential temperature ( ? e ) between 850 hPa and surface as well as difference between air and sea temperatures altogether gradually began to increase in the pre-snowfall period and reached their maximum values in the course of the period, whose air (850 hPa) — sea temperature difference and snowfall intensity in case of the heavy snowfall episodes are almost larger than 20°C and 6 tims greater than the weak snowfall episodes, respectively. Interestingly, snowfall appeared to begin in case of an air-sea temperature difference exceeding over 15°C. The current analysis is overall consistent with the previous finding (Lee et al., 2012) that an instabilityinduced moisture supply to the lower atmosphere from the East sea, being cooled and saturated in the lower layer, so to speak, East Sea-Effect Snowfall (SES), would make a low-level ice cloud which eventually moves inland by the easterly flow. In addition, a longlasting synoptic characteristics and convergence-induced invigoration also appear to play the important roles in the severe snowstorms. Improvements in our understanding of mesoscale sea-effect snowstorms require detailed in-situ and remote sensing observations over and around East Sea since observations of the concurrent thermodynamic and microphysical characteristics have not been available there and this study emphasizes the importance of low level stability as quantitative estimation of moist static energy generation over the East Sea.

  4. Altered snowfall and soil disturbance influence the early life stage transitions and recruitment of a native and invasive grass in a cold desert.

    PubMed

    Gornish, Elise S; Aanderud, Zachary T; Sheley, Roger L; Rinella, Mathew J; Svejcar, Tony; Englund, Suzanne D; James, Jeremy J

    2015-02-01

    Climate change effects on plants are expected to be primarily mediated through early life stage transitions. Snowfall variability, in particular, may have profound impacts on seedling recruitment, structuring plant populations and communities, especially in mid-latitude systems. These water-limited and frequently invaded environments experience tremendous variation in snowfall, and species in these systems must contend with harsh winter conditions and frequent disturbance. In this study, we examined the mechanisms driving the effects of snowpack depth and soil disturbance on the germination, emergence, and establishment of the native Pseudoroegnaria spicata and the invasive Bromus tectorum, two grass species that are widely distributed across the cold deserts of North America. The absence of snow in winter exposed seeds to an increased frequency and intensity of freeze-thaw cycles and greater fungal pathogen infection. A shallower snowpack promoted the formation of a frozen surface crust, reducing the emergence of both species (more so for P. spicata). Conversely, a deeper snowpack recharged the soil and improved seedling establishment of both species by creating higher and more stable levels of soil moisture availability following spring thaw. Across several snow treatments, experimental disturbance served to decrease the cumulative survival of both species. Furthermore, we observed that, regardless of snowpack treatment, most seed mortality (70-80%) occurred between seed germination and seedling emergence (November-March), suggesting that other wintertime factors or just winter conditions in general limited survival. Our results suggest that snowpack variation and legacy effects of the snowpack influence emergence and establishment but might not facilitate invasion of cold deserts. PMID:25539620

  5. Peculiarities of the nighttime winter foF2 increase over Irkutsk

    Microsoft Academic Search

    Olga Pirog; Marat Deminov; Galina Deminova; Gelii Zherebtsov; Nelya Polekh

    2011-01-01

    An analysis of properties and peculiarities of the nighttime winter foF2 increases (NWI) in the East Siberia is made on data of ionospheric station Irkutsk in the periods 1958–1992 and 2002–2009 and the empirical model of the F2 layer critical frequency under the geomagnetic quiet conditions deduced from these data (model Q-F2). It is revealed, that the NWI is the

  6. Snowfall-Driven Growth in East Antarctic Ice Sheet Mitigates Recent Sea-Level Rise

    Microsoft Academic Search

    Curt H. Davis; Yonghong Li; Joseph R. McConnell; Markus M. Frey; Edward Hanna

    2005-01-01

    Satellite radar altimetry measurements indicate that the East Antarctic ice-sheet interior north of 81.6°S increased in mass by 45 +\\/- 7 billion metric tons per year from 1992 to 2003. Comparisons with contemporaneous meteorological model snowfall estimates suggest that the gain in mass was associated with increased precipitation. A gain of this magnitude is enough to slow sea-level rise by

  7. Cross Validation of Spaceborne and Ground Polarimetric Radar Snowfall Retrievals

    NASA Astrophysics Data System (ADS)

    Wen, Y.; Hong, Y.; Cao, Q.; Kirstetter, P.; Gourley, J. J.; Zhang, J.

    2013-12-01

    Snow, as a primary contribution to regional or even global water budgets is of critical importance to our society. For large-scale weather monitoring and global climate studies, satellite-based snowfall observations with ground validations have become highly desirable. Ground-based polarimetric weather radar is the powerful validation tool that provides physical insight into the development and interpretation of spaceborne snowfall retrievals. This study aims to compare and resolve discrepancies in snowfall detection and estimation between Cloud Profiling Radar (CPR) on board NASA's Cloudsat satellite and new polarimetric National Mosaic and Multi-sensor QPE (NMQ) system (Q3) developed by OU and NOAA/NSSL scientists. The Global Precipitation Measurement Mission with its core satellite scheduled for launch in 2014 will carry active and passive microwave instrumentation anticipated to detect and estimate snowfall or snowpack. This study will potentially serve as the basis for global validation of space-based snowfall products and also invite synergistic development of coordinated space-ground multisensor snowfall products.

  8. Influence of projected snow and sea-ice changes on future climate in heavy snowfall region

    NASA Astrophysics Data System (ADS)

    Matsumura, S.; Sato, T.

    2011-12-01

    Snow/ice albedo and cloud feedbacks are critical for climate change projection in cryosphere regions. However, future snow and sea-ice distributions are significantly different in each GCM. Thus, surface albedo in cryosphere regions is one of the causes of the uncertainty for climate change projection. Northern Japan is one of the heaviest snowfall regions in the world. In particular, Hokkaido is bounded on the north by the Okhotsk Sea, where is the southernmost ocean in the Northern Hemisphere that is covered with sea ice during winter. Wintertime climate around Hokkaido is highly sensitive to fluctuations in snow and sea-ice. The purpose of this study is to evaluate the influence of global warming on future climate around Hokkaido, using the Pseudo-Global-Warming method (PGW) by a regional climate model. The boundary conditions of the PGW run were obtained by adding the difference between the future (2090s) and past (1990s) climates simulated by coupled general circulation model (MIROC3.2 medres), which is from the CMIP3 multi-model dataset, into the 6-hourly NCEP reanalysis (R-2) and daily OISST data in the past climate (CTL) run. The PGW experiments show that snow depth significantly decreases over mountainous areas and snow cover mainly decreases over plain areas, contributing to higher surface warming due to the decreased snow albedo. Despite the snow reductions, precipitation mainly increases over the mountainous areas because of enhanced water vapor content. However, precipitation decreases over the Japan Sea and the coastal areas, indicating the weakening of a convergent cloud band, which is formed by convergence between cold northwesteries from the Eurasian continent and anticyclonic circulation over the Okhotsk Sea. These results suggest that Okhotsk sea-ice decline may change the atmospheric circulation and the resulting effect on cloud formation, resulting in changes in winter snow or precipitation. We will also examine another CMIP3 model (MRI-CGCM2.3.2), which sensitivity of surface albedo to surface air temperature is the lowest in the CMIP3 models.

  9. Decadal increase of organic compounds in winter and spring atmospheric aerosols in East Asia

    NASA Astrophysics Data System (ADS)

    Kundu, S.; Kawamura, K.; Kobayashi, M.; Tachibana, E.; Lee, M.; Jung, J.

    2014-12-01

    A rapid economic growth in China and other East Asian countries may have changed molecular level organic composition of atmospheric aerosols in East Asia. Molecular level composition is required to better evaluate the roles of organic aersols on climate, air quality and public health. Diacids and oxoacids account for a significant fraction of atmospheric organic matter and their secondary sources are more important than their primary sources. Atmospheric aerosol samples (n = 698) were collected during 2001-2008 at Gosan site in Jeju Island, South Korea. They were analyzed for saturated (C2-C10), unsaturated aliphatic (C4-C5), multifunctional (C3-C7) and aromatic (C8) diacids and oxoacids (C2-C9). According to monthly average concentration, oxalic acid (C2) is the most abundant followed by malonic acid (C3) and succinic acid (C4) in the homologous series of saturated diacids (C2-C10) whereas glyoxylic acid (?C2) is most abundant in the homologous series of oxoacids (C2-C9). The monthly median, 25th percentile and 75th percentile concentrations of saturated and multifunctional diacids and oxoacids showed the highest in spring (March-May). In contrast, those concentrations for unsaturated aliphatic and aromatic diacids were observed the highest in winter (December-February). The monthly median and percentile (25th and 75th) concentrations of all diacids and oxoacids showed the second peak in the autumn (September-November) while those concentrations were recorded lowest in summer (June-August). A steady increment or decrement was not found in the monthly median and percentile (25th and 75th) concentrations of diacids and oxoacids in any month. However, the curve fitting of those concentrations over the study period shows an incremental trend for major diacids and oxoacids in winter and spring. For example, the monthly median, 25th percentile and 75th percentile concentrations of all major diacids and oxoacids increased up to 3 times from 2001 to 2008 in winter and spring. This study for the first time demonstrates the decadal increase of organic aerosols in East Asia and we discuss the bimodal seasonal variations and incremental trend of organic aerosols based on the annual behavior of ozone, carbon monoxide, and air mass transport pattern in East Asia.

  10. Effect of reduced winter precipitation and increased temperature on watershed solute flux, 1988-2002, Northern Michigan

    USGS Publications Warehouse

    Stottlemyer, R.; Toczydlowski, D.

    2006-01-01

    Since 1987 we have studied weekly change in winter (December-April) precipitation, snowpack, snowmelt, soil water, and stream water solute flux in a small (176-ha) Northern Michigan watershed vegetated by 65-85 year-old northern hardwoods. Our primary study objective was to quantify the effect of change in winter temperature and precipitation on watershed hydrology and solute flux. During the study winter runoff was correlated with precipitation, and forest soils beneath the snowpack remained unfrozen. Winter air temperature and soil temperature beneath the snowpack increased while precipitation and snowmelt declined. Atmospheric inputs declined for H+, NO 3- , NH 4+ , dissolved inorganic nitrogen (DIN), and SO 42- . Replicated plot-level results, which could not be directly extrapolated to the watershed scale, showed 90% of atmospheric DIN input was retained in surface shallow (<15 cm deep) soils while SO 42- flux increased 70% and dissolved organic carbon (DOC) 30-fold. Most stream water base cation (C B), HCO 3- , and Cl- concentrations declined with increased stream water discharge, K+, NO 3- , and SO 42- remained unchanged, and DOC and dissolved organic nitrogen (DON) increased. Winter stream water solute outputs declined or were unchanged with time except for NO 3- and DOC which increased. DOC and DIN outputs were correlated with the percentage of winter runoff and stream discharge that occurred when subsurface flow at the plot-level was shallow (<25 cm beneath Oi). Study results suggest that the percentage of annual runoff occurring as shallow lateral subsurface flow may be a major factor regulating solute outputs and concentrations in snowmelt-dominated ecosystems. ?? Springer 2006.

  11. Climatic Warming Increases Winter Wheat Yield but Reduces Grain Nitrogen Concentration in East China

    PubMed Central

    Deng, Aixing; Song, Zhenwei; Zhang, Baoming; Zhang, Weijian

    2014-01-01

    Climatic warming is often predicted to reduce wheat yield and grain quality in China. However, direct evidence is still lacking. We conducted a three-year experiment with a Free Air Temperature Increase (FATI) facility to examine the responses of winter wheat growth and plant N accumulation to a moderate temperature increase of 1.5°C predicted to prevail by 2050 in East China. Three warming treatments (AW: all-day warming; DW: daytime warming; NW: nighttime warming) were applied for an entire growth period. Consistent warming effects on wheat plant were recorded across the experimental years. An increase of ca. 1.5°C in daily, daytime and nighttime mean temperatures shortened the length of pre-anthesis period averagely by 12.7, 8.3 and 10.7 d (P<0.05), respectively, but had no significant impact on the length of the post-anthesis period. Warming did not significantly alter the aboveground biomass production, but the grain yield was 16.3, 18.1 and 19.6% (P<0.05) higher in the AW, DW and NW plots than the non-warmed plot, respectively. Warming also significantly increased plant N uptake and total biomass N accumulation. However, warming significantly reduced grain N concentrations while increased N concentrations in the leaves and stems. Together, our results demonstrate differential impacts of warming on the depositions of grain starch and protein, highlighting the needs to further understand the mechanisms that underlie warming impacts on plant C and N metabolism in wheat. PMID:24736557

  12. Atmospheric Variability And Its Influence On Winter Hydroclimate In Upstate New York

    NASA Astrophysics Data System (ADS)

    Millar, S. W.

    2008-12-01

    Hydroclimatic trends are frequently used to assess regional impacts of global climate change, requiring that the combined effects of linear trends and non-linear quasi-periodic fluctuations associated with hemispheric- scale teleconnections be identified. Separating these effects is especially problematic outside the statistical nodes of influence, such as in the Great Lakes drainage area of Upstate New York (UNY). Daily mean temperature, precipitation and snowfall data, and streamflow were analyzed from 1950 to 2007, to determine relationships between regional hydroclimate and atmospheric teleconnections. Non-parameteric testing was used: the Mann-Kendall trend test to assess linear changes; and the Kruskal-Wallis and multiple comparison tests to observe differences due to the NAO, ENSO, PNA, and PDO teleconnections. The results highlight five key findings: the importance of the NAO on regional temperatures in December; the significance of the PNA and PDO on January hydroclimate; the role of ENSO in March snowfall; a strong linear trend in October of increasing precipitation, decreasing temperature and increasing streamflow; and a strong linear increase in snowfall in the lake snow-affected regions. Teleconnection linkages generally parallel relationships observed in neighboring regions; however, effects in UNY follow an intra-seasonal variation in Atlantic and Pacific influences. For winter forecasting these results suggest an affinity with New England in December, Ohio River Valley in January, and the Great Lakes in March. Aside from the NAO, the lack of regional coherence suggests, that although subhemispheric-scale linkages exist, they are not the dominant signal; the increasing January snowfall is a long-term linear change.

  13. Elevated streamflows increase dam passage by juvenile coho salmon during winter: Implications of climate change in the Pacific Northwest

    USGS Publications Warehouse

    Kock, Tobias J.; Liedtke, Theresa L.; Rondorf, Dennis W.; Serl, John D.; Kohn, Mike; Bumbaco, Karin A.

    2012-01-01

    A 4-year evaluation was conducted to determine the proportion of juvenile coho salmon Oncorhynchus kisutch passing Cowlitz Falls Dam, on the Cowlitz River, Washington, during winter. River and reservoir populations of coho salmon parr were monitored using radiotelemetry to determine if streamflow increases resulted in increased downstream movement and dam passage. This was of interest because fish that pass downstream of Cowlitz Falls Dam become landlocked in Riffe Lake and are lost to the anadromous population. Higher proportions of reservoir-released fish (0.391-0.480) passed Cowlitz Falls Dam than did river-released fish (0.037-0.119). Event-time analyses demonstrated that streamflow increases were important predictors of dam passage rates during the study. The estimated effect of increasing streamflows on the risk of dam passage varied annually and ranged from 9% to 75% for every 28.3 m3/s increase in streamflow. These results have current management implications because they demonstrate the significance of dam passage by juvenile coho salmon during winter months when juvenile fish collection facilities are typically not operating. The results also have future management implications because climate change predictions suggest that peak streamflow timing for many watersheds in the Pacific Northwest will shift from late spring and early summer to winter. Increased occurrence of intense winter flood events is also expected. Our results demonstrate that juvenile coho salmon respond readily to streamflow increases and initiate downstream movements during winter months, which could result in increased passage at dams during these periods if climate change predictions are realized in the coming decades.

  14. WRF simulations of two extreme snowfall events associated with contrasting extratropical cyclones over the western and central Himalaya

    NASA Astrophysics Data System (ADS)

    Norris, J.; Carvalho, L. M. V.; Jones, C.; Cannon, F.

    2015-04-01

    Two extreme snowfall events associated with extratropical cyclones, one interacting with the western and one with the central Himalaya, are simulated with the Weather Research and Forecasting (WRF) model over 8 days. One event in January 1999 was driven by a longwave trough over west Asia, with the cyclone becoming terrain-locked in the western Himalayan notch. Another event in March 2006 was driven by a trough further south and east, facilitating the passage of two successive cyclones along the entire Himalayan ridge, drawing moisture from warm tropical waters. These flow patterns are typical for extreme winter precipitation in the western and central Himalaya, respectively, but were amplified in these two cases. In the WRF simulations, snowfall is confined to the western Himalaya in the January simulation, while a near-continuous band of accumulated snowfall along the Himalayan ridge forms in the March simulation. Precipitation rate throughout both simulations is largely determined by cross-barrier moisture flux, which is generally greatest wherever the cyclonic winds converge on the mountains at each time. However, the March 2006 simulation evolves in an environment with greater convective instability upwind of and moisture transport toward the mountains than in the January 1999 event. Hence, greater precipitation rates and more solid snowbands are generated in the March than in the January simulation. However, due to the terrain-locking of the cyclone in the January event, individual locations receive more persistent snowfall, so that the greatest 8 day accumulations are similar between the two events, although these accumulations are more widespread in the March event.

  15. Digital Investigation of Great Lakes Regional Snowfall, 1951-1980

    E-print Network

    Laboratory 2205 Commonwealth Boulevard Ann Arbor, Michigan 48105-1593, U.S.A. A snowfall database the concept of geographically-defined normals and new windowing techniques. The potential for incorporation can be done with this digital database. 67 #12;DATAIIASE The database used in this study is described

  16. Peculiarities of the night-time winter increase in the critical frequency of F2 layer over Irkutsk

    Microsoft Academic Search

    Olga Pirog; Gelii Zherebtsov; Nelya Polekh; Marat Deminov; Galina Deminova

    2010-01-01

    We present an analysis of peculiarities of the night-time winter foF2 increase (NWI) in the East Siberia. Data from ionospheric station Irkutsk (52.5 N. 104.0 E) in the periods 1958-1992, 2002-2010 and the empirical model of the F2 layer critical frequency under magnetically quiet conditions deduced from these data (model Q-F2) are used in this study. Based on the model

  17. Effect of sea surface temperature errors on snowfall1 in WRF: a case study of a heavy snowfall event in2

    E-print Network

    Park, Rokjin

    32 simulations were run for the Yellow Sea during December 2012, when a severe33 snowfall occurred. The changes in surface air temperature over39 the Yellow Sea were positively correlated with a warm (or cold surface temperature, Snowfall, WRF, Yellow Sea, OSTIA49 #12;3 1. Introduction50 Sea surface temperature

  18. An Evaluation of Satellite Retrievals of Snowfall in Regions of Complex Terrain

    NASA Astrophysics Data System (ADS)

    Reed, K. A.; Nesbitt, S. W.; Kulie, M.; L'Ecuyer, T. S.; Wood, N.

    2013-12-01

    Snowfall in regions of complex terrain plays an important role in the global hydrologic cycle, and can have major physical and social implications ranging from water resource management, to flash flooding, to climate change impacts. Due to the diversity of impacts that can result from snowfall, the ability to directly observe and measure snowfall in real-time is of great importance. However, the physical limitations of ground-based radars particularly in complex terrain and the lack of spatially complete measurement networks in mountainous regions make high-resolution ground-based snowfall observations a challenging task. Spaceborne satellite retrievals of snowfall such as those that will be made possible by the Global Precipitation Measurement (GPM) mission offer the ability to make high spatial and temporal resolution measurements that are otherwise not possible using traditional ground-based methods. This study seeks to investigate the skill level of current spaceborne snowfall products over the complex terrain of the Rocky Mountains in the western United States. Satellite derived snowfall products from measurements obtained via instruments including the CloudSat Cloud Profiling Radar (CPR), EOS Aqua Advanced Microwave Scanning Radiometer for EOS (AMSR-E), and GCOM-W1 Advanced Microwave Scanning Radiometer 2 (AMSR2) are evaluated using ground-based observations such as the Natural Resources Conservation Service Snow Telemetry (SNOTEL) data and the NCEP Stage IV data. Satellite derived snowfall variables including snowfall rate and snow water equivalent are compared to ground-based observations to determine the overall accuracy and skill level of current satellite derived snowfall products in the region of interest. An analysis is also done to determine how the accuracy and skill level change based on varying snowfall regimes such as light, moderate, and heavy snowfall events. The knowledge gained will be used to determine how satellite derived snowfall measurements in regions of complex terrain may be improved upon for future missions including GPM.

  19. Response of daily snowfall extremes to climate change: theory and simulations

    NASA Astrophysics Data System (ADS)

    O'Gorman, P. A.

    2014-12-01

    Snowfall is sensitive to climate change through changes in air temperature, humidity, and dynamics. Because of the sensitivity to temperature, annual-mean snowfall is expected to decrease in a warming climate except in very cold regions. However, it is shown here that CMIP5 models simulate smaller fractional changes in the intensities of daily snowfall extremes than in mean snowfall for many regions and months of the year. An asymptotic theory is introduced for snowfall extremes based on the temperature dependencies of the rain-snow transition and precipitation extremes. The theory accounts for the main features of the response of snowfall extremes to warming in the simulations. A variant of the theory that better accounts for the role of dynamics will also be discussed.

  20. Heat shock induces production of reactive oxygen species and increases inner mitochondrial membrane potential in winter wheat cells.

    PubMed

    Fedyaeva, A V; Stepanov, A V; Lyubushkina, I V; Pobezhimova, T P; Rikhvanov, E G

    2014-11-01

    Heat shock leads to oxidative stress. Excessive ROS (reactive oxygen species) accumulation could be responsible for expression of genes of heat-shock proteins or for cell death. It is known that in isolated mammalian mitochondria high protonic potential on the inner membrane actuates the production of ROS. Changes in viability, ROS content, and mitochondrial membrane potential value have been studied in winter wheat (Triticum aestivum L.) cultured cells under heat treatment. Elevation of temperature to 37-50°C was found to induce elevated ROS generation and increased mitochondrial membrane potential, but it did not affect viability immediately after treatment. More severe heat exposure (55-60°C) was not accompanied by mitochondrial potential elevation and increased ROS production, but it led to instant cell death. A positive correlation between mitochondrial potential and ROS production was observed. Depolarization of the mitochondrial membrane by the protonophore CCCP inhibited ROS generation under the heating conditions. These data suggest that temperature elevation leads to mitochondrial membrane hyperpolarization in winter wheat cultured cells, which in turn causes the increased ROS production. PMID:25540005

  1. Projected increases in summer and winter UK sub-daily precipitation extremes from high-resolution regional climate models

    NASA Astrophysics Data System (ADS)

    Chan, S. C.; Kendon, E. J.; Fowler, H. J.; Blenkinsop, S.; Roberts, N. M.

    2014-08-01

    Summer (June-July-August JJA) UK precipitation extremes projections from two UK Met Office high-resolution (12 km and 1.5 km) regional climate models (RCMs) are shown to be resolution dependent. The 1.5 km RCM projects a uniform (\\approx 10%) increase in 1 h JJA precipitation intensities across a range of return periods. The 12 km RCM, in contrast, projects decreases in short return period (??5 years) events but strong increases in long return period (?20 years) events. We have low physical and statistical confidence in the 12 km RCM projections for longer return periods. Both models show evidence for longer dry periods between events. In winter (December-January-February DJF), the models show larger return level increases (?40%). Both DJF projections are consistent with results from previous work based on coarser resolution models.

  2. On the characteristics of atmospheric circulation associated with snowfall in NW Greece

    Microsoft Academic Search

    E. E. Houssos; C. J. Lolis; A. Bartzokas

    2009-01-01

    In this work the main atmospheric circulation types, associated with snowfall events in NW Greece, are examined. Also, a validation procedure is followed in order to investigate to what extent the circulation types revealed are related with snowfall in NW Greece. For this purpose, two datasets are used. The first one consists of 6-hourly values of mean sea level pressure,

  3. Early stage de-etiolation increases the ferulic acid content in winter triticale seedlings under full sunlight conditions.

    PubMed

    Hura, Tomasz; Hura, Katarzyna; Grzesiak, Maciej

    2010-12-01

    In the presented work an attempt has been made to estimate the phenolics content and its implication for the protection of the photosynthetic apparatus in course of a plant's de-etiolation. The experiments were carried out on two genotypes of winter triticale varying in their resistance to drought. The activity of the photosynthetic apparatus was monitored by taking measurements of chlorophyll fluorescence and chlorophyll/carotenoids content. Analyses of the total pool of phenolic compounds and ferulic acid as well as l-phenylalanine ammonia lyase activity were completed. The first illuminations of etiolated seedlings induced a chlorophyll synthesis, which was followed by the increasing activity of the photosynthetic apparatus in both studied genotypes. Piano exhibited a higher values of the maximum quantum efficiency of photosystem II primary photochemistry during de-etiolation than Imperial. These results may just indicate that for Imperial, the delivery of photons to the reaction centres exceeded the capacity of the photosynthetic apparatus to transduce this energy via electron transport. An increase in the content of ferulic acid was more noticeable for Piano and seems to be a consequence of adaptation to the new light conditions. It should be taken into account, that an increase of ferulic acid content during early stage of de-etiolation, may limit the photoinhibition of photosynthesis whenever radiation is excessive for the photosynthetic apparatus. PMID:20719528

  4. A Winter's Tale

    NSDL National Science Digital Library

    This resource explores winter weather and frozen precipitation. The page on precipitation points out that snow and rain are both water and explains how the different forms of frozen precipitation (snow, sleet, freezing rain) occur. There is a page on cirrus clouds that explains their characterstics and how they may affect climate by reflecting solar radiation or reducing outgoing infrared energy from Earth. The Jet Stream page explains the characteristics of these high-speed rivers of air, including what causes them and their effect on weather and climate. There is also a feature on the esthetic wonders of frozen water, including halos produced by ice crystals in the air, sparkling of snowflakes, why fresh snow squeaks when stepped on, and why it is silent during a snowfall. A bibliography is also provided.

  5. Sorting out non-sorted circles: Effects of winter climate change on the Collembola community of cryoturbated subarctic tundra

    NASA Astrophysics Data System (ADS)

    Krab, Eveline; Monteux, Sylvain; Becher, Marina; Blume-Werry, Gesche; Keuper, Frida; Klaminder, Jonatan; Kobayashi, Makoto; Lundin, Erik J.; Milbau, Ann; Roennefarth, Jonas; Teuber, Laurenz Michael; Weedon, James; Dorrepaal, Ellen

    2015-04-01

    Non-sorted circles (NSC) are a common type of cryoturbated (frost-disturbed) soil in the arctic and store large amounts of soil organic carbon (SOC) by the burial of organic matter. They appear as sparsely vegetated areas surrounded by denser tundra vegetation, creating patterned ground. Snowfall in the arctic is expected to increase, which will modify freezing intensity and freeze-thaw cycles in soils, thereby impacting on SOC dynamics. Vegetation, soil fauna and microorganisms, important drivers of carbon turnover, may benefit directly from the altered winter conditions and the resulting reduction in cryoturbation, but may also impact each other through trophic cascading. We investigated how Collembola, important decomposer soil fauna in high latitude ecosystems, are affected by increased winter insulation and vegetation cover. We subjected NSC in North-Swedish subarctic alpine tundra to two years of increased thermal insulation (snow fences or fiber cloth) in winter and spring, increasing soil temperatures and strongly reducing freeze-thaw frequency. From these NSC we sampled the Collembola community in: (i) the non-vegetated center, (ii) sparsely vegetated parts in the center and (iii) the vegetated domain surrounding NSC. To link changes in Collembola density and community composition to SOC dynamics, we included measurements of decomposer activity, dissolved organic carbon (DOC) and total extractable nitrogen (TN). We observed differences in Collembola density, community composition and soil fauna activity between the sampling points in the NSC. Specifically Collembola diversity increased with the presence of vegetation and density was higher in the vegetated outer domains. Increased winter insulation did not affect diversity but seemed to negatively affect density and decomposer activity in the vegetated outer domains. Interestingly, SOM distribution over NSC changed with snow addition (also to a lesser extent with fleece insulation) towards less SOM in the vegetated outer domains. This corresponded to a general decrease in Collembola density and activity and to alterations in carbon mobilization (a decrease in extractable DOC). Changing SOM distribution in shallower soil layers might be an important mechanism by which increased snowfall in winter will affect subarctic patterned soils and its carbon dynamics. Our results indicate that the bottom-up effects of altered SOM availability and the establishment of vegetation are more likely to drive the decomposer community and its activity than direct winter-warming effects. Eventually, the extent to which SOM will redistribute and vegetation will expand into the non-vegetated parts of NSC will determine the magnitude of effects on decomposers and their activity. The new balance between plant productivity, SOC burial and carbon released by decomposers, will determine the fate of the large amounts of carbon stored in cryoturbated soils.

  6. A new look at lake-effect snowfall trends in the Laurentian Great Lakes using a temporally homogeneous data set

    Microsoft Academic Search

    Kenneth E. Kunkel; Leslie Ensor; Michael Palecki; David Easterling; David Robinson; Kenneth G. Hubbard; Kelly Redmond

    2009-01-01

    Snowfall data are subject to quality issues that affect their usefulness for detection of climate trends. A new analysis of lake-effect snowfall trends utilizes a restricted set of stations identified as suitable for trends analysis based on a careful quality assessment of long-term observation stations in the lake-effect snowbelts of the Laurentian Great Lakes. An upward trend in snowfall was

  7. The Influence of Regional Storm Tracking and Teleconnections on Winter Precipitation in the Northeastern United States

    Microsoft Academic Search

    James A. Bradbury; Barry D. Keim; Cameron P. Wake

    2003-01-01

    Secular changes in regional storm tracking are examined as physical mechanisms for observed teleconnections between the New England hydroclimate and four predictor variables: the Southern Oscillation Index, the North Atlantic Oscillation, the Pacific Decadal Oscillation, and regional sea-surface temperatures. The main modes of New England winter precipitation, snowfall, and cyclone variability are resolved using varimax rotated principal component analysis. The

  8. High Frequency Microwave-based Snowfall Rate Estimation using an Artificial Neural Network Approach

    NASA Astrophysics Data System (ADS)

    Zahraei, A.; Hernandez, C.; Mahani, S. E.; Khanbilvardi, R.

    2012-12-01

    There are regions in the world with significant dependency on the melted water from accumulated snow to strive against freshwater resources scarcity. In the U.S, there are several states including California and Arizona where melting snow plays an important role to manage growing unmet freshwater demand. Nevertheless, an accurate estimate of snowfall is always a major challenge for water resources management communities. Arguably, ground-based gauges and radar have been utilized to measure snowfall. Considering the sparse network or lack of spatial coverage of ground-based instruments, it is required to deploy satellite-based technologies without existing ground-based sensors limitations and errors. Sensitivity of high frequency microwave (MW) range of electromagnetic to ice particles and snowflakes lead us to use satellite-based MW brightness temperature (BT) to estimate snowfall rate. To meet the main objective of this study that is using satellite-retrieved microwave signals to improve capability of snowfall rate estimation from space, we are developing a multi-frequency algorithm based on an artificial neural network (ANN) system. The developed algorithm will estimate snowfall rate using microwave frequencies from the Advanced Microwave Sounding Unit (AMSU)-B. The preliminary results show that any combination of MW channels including high frequency band of 183±7 GHz is more related to snowfall amount than the ones without this channel. These results also reveal the promising performance of the ANN-based models in the estimation of snowfall in higher latitude and mountainous regions with average correlation coefficient of 0.55 for independent validation cases.

  9. Respiration and Microbial Dynamics in Two Subarctic Ecosystems during Winter and Spring Thaw: Effects of Increased Snow Depth

    E-print Network

    Grogan, Paul

    ), and the thermal insulation of snow cover restricts winter soil temperature minima despite low air temperatures activity in plants and soil microbes of the Arctic was traditionally assumed to be very low during the cold insulates the soil, reduces temperature fluctuations, and const

  10. Summer-winter hemispheric asymmetry of the sudden increase in ionospheric total electron content and of the O\\/N2 ratio: Solar activity dependence

    Microsoft Academic Search

    T. Tsugawa; S.-R. Zhang; Y. Otsuka; J. Sato; A. Saito; Y. Zhang; L. J. Paxton

    2007-01-01

    The solar activity dependence of the summer-winter hemispheric asymmetry (SWHA) of the sudden increase in total electron content (SITEC) due to solar flares and of the O\\/N2 ratio is statistically analyzed using global GPS-total electron content data and TIMED Global Ultraviolet Imager column O\\/N2 ratio data. We focus on observations with nonnegligible residuals of the solar zenith angle (SZA) dependency

  11. Winter Storm

    NSDL National Science Digital Library

    Sarah

    2009-09-28

    This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. Does increased humidity usually increase of decrease your chances for rain? 4. What happens when there is ...

  12. Estimation of snow microphysical properties with application to millimeter-wavelength radar retrievals for snowfall rate

    NASA Astrophysics Data System (ADS)

    Wood, Norman Bryce

    The need for measuring snowfall is driven by the roles snow plays providing freshwater resources and affecting climate. Snow accumulations are an important resource for ecological and human needs and in many areas appear vulnerable to climate change. Snow cover modifies surface heat fluxes over areas extensive enough to influence climate at regional and perhaps global scales. Seasonal runoff from snowmelt, along with over-ocean snowfall, contributes to freshening in the Arctic and high-latitude North Atlantic oceans. Yet much of the Earth's area for which snowfall plays such significant roles is not well-monitored by observations. Radar reflectivity at 94 GHz is sensitive to scattering by snow particles and CloudSat, in a near-polar orbit, provides vertically resolved measurements of 94 GHz reflectivity at latitudes from 82 N to 82 S. While not global in areal coverage, CloudSat does provide observations sampled from regions where snowfall is the dominant form of precipitation and an important component of hydrologic processes. The work presented in this study seeks to exploit these observations by developing and assessing a physically-base snowfall retrieval which uses an explicit representation of snow microphysical properties. As the reflectivity-based snowfall retrieval problem is significantly underconstrained, a priori information about snow microphysical properties is required. The approaches typically used to develop relations between reflectivity and snowfall rate, so-called Ze-S relations, require assumptions about particle properties such as mass, area, fallspeed, and shape. Limited information about the distributions of these properties makes difficult the characterization of how uncertainties in the properties influence uncertainties in the Ze-S relations. To address this, the study proceeded in two parts. In the first, probability distributions for snow particle microphysical properties were assessed using optimal estimation applied to multi-sensor surface-based snow observations from a field campaign. Mass properties were moderately well determined by the observations, the area properties less so. The retrieval revealed nontrivial correlations between mass and area parameters not apparent in prior studies. Synthetic testing showed that the performance of the retrieval was hampered by uncertainties in the fallspeed forward model. The mass and area properties obtained from this retrieval were used to construct particle models including 94 GHz scattering properties for dry snow. These properties were insufficient to constrain scattering properties to match observed 94 GHz reflectivities. Vertical aspect ratio supplied a sufficient additional constraint. In the second part, the CloudSat retrieval, designed to estimate vertical profiles of snow size distribution parameters from reflectivity profiles, was applied to measurements from the field campaign and from an orbit of CloudSat observations. Uncertainties in the mass and area microphysical properties, obtained from the first part of this study, were substantial contributors to the uncertainties in the retrieved snowfall rates. Snowfall rate fractional uncertainties were typically 140% to 200%. Accumulations of snowfall calculated from the retrieval results matched observed accumulations to within 13%, however, when allowances were made for snowfall with properties likely inconsistent with the snow particle model. Information content metrics showed that the size distribution slope parameters were moderately to strongly constrained by the reflectivity observations, while the intercept parameters were determined primarily by the a priori constraints. Results from the CloudSat orbit demonstrated the ability of the CloudSat retrieval to represent a range of scene-dependent Ze-S relations.

  13. Relationship between the trajectory of mid-latitude cyclones in the eastern Pacific Ocean and the isotopic composition of snowfall in the Sierra Nevada, California

    NASA Astrophysics Data System (ADS)

    Vasquez, K. T.; Sickman, J. O.; Lucero, D. M.; Heard, A. M.

    2014-12-01

    Climate change has caused a change in the Sierra Nevada snowpack and the timing of its snowmelt, threatening a valuable water resource that provides for 25 million people and 5 million hectares of irrigated land. Understanding past and future variations in the snowpack is crucial in order to plan future water management. Of particular importance would be an archive of the variability of past snowfall, which can be recorded through the isotopic records found in local paleoproxies (e.g., diatoms). We propose to quantify the relationship between sources of atmospheric moisture in the Sierra Nevada and the isotopic composition of its snowpack to uncover whether isotopic variations recorded in paloearchives are a result of the isotopic composition of the precipitation, thereby showing whether these archives could serve as a reliable source of atmospheric moisture. Preliminary analysis conducted from December 2012 to March 2013 at Sequoia National Park resulted in statistically significant correlations between the isotopic composition of the winter snowfall and storm track trajectories. It was observed that storms originating from more northern latitudes had predominantly lighter isotopes (more negative ? 2H and ?18O) and sub-tropical/tropical Pacific storms showed more positive ? 2H and ?18O. This pattern reflects the isotopic gradient of the Pacific Ocean and can prove useful when interpreting the climatic significance of the ?2H and ?18O values in analyzed proxies. While our initial investigation was promising, the winter of 2012 -2013 was abnormally dry compared to long-term averages. Before directing our investigation to known paleoproxies, we aim to determine if the correlation between storm tracks and isotopic composition of precipitation holds in years with average and above average precipitation through analysis of archived samples from calendar years 2007 - 2011 from Giant Forest in Sequoia National Park (southern sierra) and Manzanita Lake in Lassen Volcanic National Park (northern sierra).

  14. Integrating multiple temporal scales of snowfall, soil, and plant processes at the Great Basin Desert - Sierra Nevada ecotone

    NASA Astrophysics Data System (ADS)

    Loik, M. E.

    2012-12-01

    Snowfall is the dominant hydrologic input for high elevations and latitudes of the arid- and semi-arid western United States. Many climate models envision changes in California's Sierra Nevada snow pack characteristics, which would severely impact the storage and release of water for one of the world's largest economies. Climate change threatens the sustainability of this water supply through altered snowfall timing, reduced snowpack depth, changes in snow water equivalents, earlier snowmelt, and highly-uncertain but plausible scenarios of rain-on-snow events. Climate model scenarios envision reduced snow pack and earlier melt under a warmer climate, but how will these changes affect soil and plant water relations and ecosystem processes, such as carbon storage? To address this question, experiments utilize large-scale, long-term snow fences to manipulate snow depth and melt timing at a desert-montane ecotone in eastern California, USA. A combination of instantaneous gas exchange and water potential measurements, plant community surveys, annual ring growth increments, in situ instrumentation, and long-term snow course data were used to couple physical and biological processes at daily, monthly, annual, and decadal scales. At this site, long-term April 1 snow pack depth averages 1344 mm (1928-2011) with a CV of 48%. Snow fences increased equilibrium drift snow depth by 200%. Soil moisture pulses were shorter in duration and lower in magnitude in low- than medium- or high-snowfall years. Evapotranspiration (ET) in this arid location accounted for about 37 mol m-2 d-1 of water loss from the snow pack between January 1 and May 1; sublimation was 10% of ET for the same period. Despite considerable interannual variation in snow depth and total precipitation, plant water potential stayed relatively constant over eight consecutive years, but photosynthesis was highly variable. Over the long-term, changes in snow depth and melt timing have impacted growth of only three plant species. Moreover, annual growth ring increments of the conifers Pinus jeffreyi and Pi. contorta were not equally sensitive to snow depth. Results indicate complex interactions between snow depth, soil water, and plant characteristics at multiple temporal scales, which help drive the resilience of plant processes to large interannual variations in snow depth as well as manipulated snow depth. This resilience suggests that this ecotone may be stable in the face of anticipated changes in snow depth.

  15. Spaceborne Passive Microwave Measurement of Snowfall over Land Min-Jeong Kim

    E-print Network

    Houze Jr., Robert A.

    -B observations at 89, 150 and 183.3±7, ±3, and ±1 GHz. The multi-parameter cloud model that produced brightness,16, and 17 spacecraft, provide observations at 89, 150 and 183 +1, +3, +7 GHz. Snowfall over land has been shows the distributions of the 89 and 183.3 + 7GHz brightness temperatures measured from AMSU-B at 23

  16. Winter Wonderland

    NSDL National Science Digital Library

    This data tip from Bridge, the Ocean Sciences Education Teacher Resource Center archive, includes a variety of educational sites to visit, and a data exercise on snowfall patterns using local data or historical data for Salt Lake City, Utah. Learners can also discover some of the water chemistry behind snow. The activity introduces the meteogram, a time cross-section of data for a specific surface reporting station. The data plotted include temperatures, winds, pressure, clouds and present weather.

  17. Why Does Rhinopithecus bieti Prefer the Highest Elevation Range in Winter? A Test of the Sunshine Hypothesis

    PubMed Central

    Behm, Jocelyn E.; Wang, Lin; Huang, Yong; Long, Yongcheng; Zhu, Jianguo

    2011-01-01

    Environmental factors that affect spatiotemporal distribution patterns of animals usually include resource availability, temperature, and the risk of predation. However, they do not explain the counterintuitive preference of high elevation range in winter by the black-and-white snub-nosed monkey (Rhinopithecus bieti). We asked whether variation of sunshine along with elevations is the key driving force. To test this hypothesis, we conducted field surveys to demonstrate that there was a statistically significant pattern of high elevation use during winter. We then asked whether this pattern can be explained by certain environmental factors, namely temperature, sunshine duration and solar radiation. Finally, we concluded with a possible ecological mechanism for this pattern. In this study, we employed GIS technology to quantify solar radiation and sunshine duration across the monkey's range. Our results showed that: 1) R. bieti used the high altitude range between 4100–4400 m in winter although the yearly home range spanned from 3500–4500 m; 2) both solar radiation and sunshine duration increased with elevation while temperature decreased with elevation; 3) within the winter range, the use of range was significantly correlated with solar radiation and sunshine duration; 4) monkeys moved to the areas with high solar radiation and duration following a snowfall, where the snow melts faster and food is exposed earlier. We concluded that sunshine was the main factor that influences selection of high elevation habitat for R. bieti in winter. Since some other endotherms in the area exhibit similar winter distributional patterns, we developed a sunshine hypothesis to explain this phenomenon. In addition, our work also represented a new method of integrating GIS models into traditional field ecology research to study spatiotemporal distribution pattern of wildlife. We suggest that further theoretical and empirical studies are necessary for better understanding of sunshine influence on wildlife range use. PMID:21915329

  18. Why does Rhinopithecus bieti prefer the highest elevation range in winter? A test of the sunshine hypothesis.

    PubMed

    Quan, Rui-Chang; Ren, Guopeng; Behm, Jocelyn E; Wang, Lin; Huang, Yong; Long, Yongcheng; Zhu, Jianguo

    2011-01-01

    Environmental factors that affect spatiotemporal distribution patterns of animals usually include resource availability, temperature, and the risk of predation. However, they do not explain the counterintuitive preference of high elevation range in winter by the black-and-white snub-nosed monkey (Rhinopithecus bieti). We asked whether variation of sunshine along with elevations is the key driving force. To test this hypothesis, we conducted field surveys to demonstrate that there was a statistically significant pattern of high elevation use during winter. We then asked whether this pattern can be explained by certain environmental factors, namely temperature, sunshine duration and solar radiation. Finally, we concluded with a possible ecological mechanism for this pattern. In this study, we employed GIS technology to quantify solar radiation and sunshine duration across the monkey's range. Our results showed that: 1) R. bieti used the high altitude range between 4100-4400 m in winter although the yearly home range spanned from 3500-4500 m; 2) both solar radiation and sunshine duration increased with elevation while temperature decreased with elevation; 3) within the winter range, the use of range was significantly correlated with solar radiation and sunshine duration; 4) monkeys moved to the areas with high solar radiation and duration following a snowfall, where the snow melts faster and food is exposed earlier. We concluded that sunshine was the main factor that influences selection of high elevation habitat for R. bieti in winter. Since some other endotherms in the area exhibit similar winter distributional patterns, we developed a sunshine hypothesis to explain this phenomenon. In addition, our work also represented a new method of integrating GIS models into traditional field ecology research to study spatiotemporal distribution pattern of wildlife. We suggest that further theoretical and empirical studies are necessary for better understanding of sunshine influence on wildlife range use. PMID:21915329

  19. Comparison of synoptic climatological features of the atmospheric fields in the "wintertime pressure pattern" around the Japan Islands in early winter with those in midwinter

    NASA Astrophysics Data System (ADS)

    Kato, Kuranoshin; Tomooka, Nozomi; Nishimura, Nanako; Haga, Yuichi

    2015-04-01

    In midwinter, the intense cold air outbreak frequently occurs under the so-called "wintertime pressure pattern", resulting in the huge supply of the sensible (SH) and latent (LH) heats from the Japan Sea and the heavy snowfall events in the Japan Sea side of the Japan Islands. On the other hand, the "wintertime pressure pattern" also appears frequently from November to early December (in "early winter"), although the air temperature around the Japan Islands is still rather higher than in midwinter. Kato et al. (EGU2014-3651) examined the atmospheric situations in association with the relatively large precipitation around the Japan Sea side of the Japan Islands in the "wintertime pressure pattern" even in early winter. They reported the extremely huge amount of LH and SH from the Japan Sea as in midwinter at those events, under the outbreak of the very cold Siberia air mass at least in the mature stage of that pattern. However, since the seasonal cycle of the climate system in East Asia shows the many stages with rapid transitions influenced by the Asian monsoon, the 3-dimensional structures and the atmospheric processes in the "wintertime pressure pattern" would be of rather different character between early winter and midwinter. Thus the present study performed synoptic climatological analyses on the above features in early winter by comparing with those in midwinter based on the daily weather maps by JMA, NCEP/NCAR re-analysis data, and so on, for the 1971/72 to 2009/10winter. Statistical analyses for 1971/72 to 2009/10winter revealed that, although the "wintertime pressure pattern" in early winter had rather shorter persistency than that in midwinter, the eastward surface pressure gradient around the Japan Sea area (around 40N) (corresponding to the geostrophic northerly wind component) in that pressure pattern in early winter sometimes attained the equivalent magnitude to that in midwinter. Furthermore, the increase in the appearance frequency of that pressure pattern in midwinter from that in early winter was reflected by the increase in that with the longer persistency. According to the case study for 1983/84 winter, even in the strong "wintertime pressure pattern" situations, the Siberian High began to extend to the southwestern part of the Japan Islands (around 33N) just like a part of the "moving anticyclone" as the baroclinic instability wave along that latitude in early winter. Besides, the zonal extension of the cold area intruding southward in the lower layer at those events was generally narrower than in midwinter. Further comparison of the features in the "wintertime pressure pattern" between early winter and midwinter will be also discussed in the presentation.

  20. On the characteristics of atmospheric circulation associated with snowfall in NW Greece

    NASA Astrophysics Data System (ADS)

    Houssos, E. E.; Lolis, C. J.; Bartzokas, A.

    2009-09-01

    In this work the main atmospheric circulation types, associated with snowfall events in NW Greece, are examined. Also, a validation procedure is followed in order to investigate to what extent the circulation types revealed are related with snowfall in NW Greece. For this purpose, two datasets are used. The first one consists of 6-hourly values of mean sea level pressure, temperature at 850hPa level and 500hPa height in 273 grid-points covering Europe and the Mediterranean, for the 45-year period 1/9/1957 to 31/8/2002. The second one comprises all the 6-hourly observations at the meteorological station of Ioannina (NW Greece). From the first dataset and for each meteorological parameter a data matrix is constructed consisting of 65,744 rows and 273 columns. Each column represents the time series of the parameter at each grid point and each row represents the space series (map) of the parameter at the time of each observation (4 observations per day for the 45-year period). Then, a new matrix is created by merging the matrices of MSL pressure, T-850hPa and Z-500hPa in a united matrix of 65,744 rows x 819 columns. In this way, each row represents the 3-dimensional structure of the atmosphere (based on the 3 parameters used) at the time of each observation. Next, Factor Analysis is applied on this united matrix in order to reduce the dimensionality of the data set. The 819 columns are reduced to 8 (uncorrelated Factors), describing satisfactorily the 3-dimensional structure of the atmosphere, as they explain approximately 86% of the total variance. From the second data set the observations reporting snowfall in Ioannina are found out and then a new data matrix is constructed consisting of the Factor scores rows corresponding to these observations only. In the new matrix (235 rows x 8 columns) each row describes the structure of the atmosphere over Europe and the Mediterranean in the cases of snowfall in Ioannina. Cluster Analysis (K-Means) is applied in this final matrix in order to objectively classify the 235 atmospheric structures associated with snowfall in Ioannina (NW Greece) into 9 homogeneous and distinct clusters. The optimum number of clusters is decided by using the "Jump" method, first described by Sugar and James. For each cluster the mean maps of the initial 3 meteorological parameters (MSL pressure, T-850hPa and Z-500hPa) are constructed revealing the main characteristics of the atmospheric structure during snowfall events in NW Greece. According to the main results, snowfall in NW Greece is associated with a low pressure system around Greece combined with an anticyclone over W or NW Europe, causing cold northwesterly flow over NW Greece. In the upper atmosphere, a deep 500hPa trough usually extends from W Russia to Italy and the Ionian Sea. The main differences among the 9 atmospheric structures revealed are found in the exact location of the centres of the low pressure system and the anticyclone and the exact direction of the trough axis. The final stage is an attempt to investigate whether a situation similar to one of the 9 atmospheric structures, causes snowfall in NW Greece. For this reason all the available meteorological maps were compared to the 9 created mean maps (in fact each case consists of a set of 3 maps, viz. MSL pressure, T-850, Z500). The comparisons were made by calculating the correlation coefficient between the space series of the anomalies of each case with the space series of the anomalies of the 9 mean maps. It was found that a considerable number of cases without snowfall in Ioannina are correlated well with the maps of snowfall. This can be explained by the fact that there are very many cases just before or just after snowfall in Ioannina which present an atmospheric structure very similar with the one during snowfall. Also, a couple of degrees of temperature difference may confine snowfall in higher altitudes and cause rainfall in Ioannina. Finally, it is obvious that the results would be more accurate if more meteorological parameters were used in the analysis.

  1. Correcting basin-scale snowfall in a mountainous basin using a distributed snowmelt model and remote sensing data

    NASA Astrophysics Data System (ADS)

    Shrestha, M.; Wang, L.; Koike, T.; Tsutsui, H.; Xue, Y.; Hirabayashi, Y.

    2013-09-01

    Adequate estimation of the spatial distribution of snowfall is critical in hydrologic modeling. However, this is a well-known problem in estimating basin-scale snowfall, especially in mountainous basins with data scarcity. This study focuses on correction and estimation of this spatial distribution, which considers topographic effects within the basin. A method is proposed that optimizes an altitude-based snowfall correction factor (Cfsnow). This is done through multi-objective calibration of a spatially distributed, multilayer energy and water balance-based snowmelt model (WEB-DHM-S) with observed discharge and remotely sensed snow cover data from the Moderate Resolution Imaging Spectroradiometer (MODIS). The Shuffled Complex Evolution - University of Arizona automatic search algorithm is used to obtain the optimal value of Cfsnow for minimum cumulative error in discharge and snow cover simulations. Discharge error is quantified by Nash-Sutcliffe efficiency and relative volume deviation, and snow cover error was estimated by pixel-by-pixel analysis. The study region is the heavily snow-fed Yagisawa Basin of the Upper Tone River in northeast Japan. First, the system was applied to one snow season (2002-2003), obtaining an optimized Cfsnow of 0.0007 m-1. For validation purposes, the optimized Cfsnow was implemented to correct snowfall in 2004, 2002 and 2001. Overall, the system was effective, implying improvements in correlation of simulated vs. observed discharge and snow cover. The 4 yr mean of basin-average snowfall for the corrected spatial snowfall distribution was 1160 mm (780 mm before correction). Execution of sensitivity runs against other model input and parameters indicated that Cfsnow could be affected by uncertainty in shortwave radiation and setting of the threshold air temperature parameter. Our approach is suitable to correct snowfall and estimate its distribution in poorly-gauged basins, where elevation dependence of snowfall amount is strong.

  2. Correcting basin-scale snowfall in a mountainous basin using a distributed snowmelt model and remote-sensing data

    NASA Astrophysics Data System (ADS)

    Shrestha, M.; Wang, L.; Koike, T.; Tsutsui, H.; Xue, Y.; Hirabayashi, Y.

    2014-02-01

    Adequate estimation of the spatial distribution of snowfall is critical in hydrologic modelling. However, this is a well-known problem in estimating basin-scale snowfall, especially in mountainous basins with data scarcity. This study focuses on correction and estimation of this spatial distribution, which considers topographic effects within the basin. A method is proposed that optimises an altitude-based snowfall correction factor (Cfsnow). This is done through multi-objective calibration of a spatially distributed, multilayer energy and water balance-based snowmelt model (WEB-DHM-S) with observed discharge and remotely sensed snow cover data from the Moderate Resolution Imaging Spectroradiometer (MODIS). The Shuffled Complex Evolution-University of Arizona (SCE-UA) automatic search algorithm is used to obtain the optimal value of Cfsnow for minimum cumulative error in discharge and snow cover simulations. Discharge error is quantified by Nash-Sutcliffe efficiency and relative volume deviation, and snow cover error was estimated by pixel-by-pixel analysis. The study region is the heavily snow-fed Yagisawa Basin of the Upper Tone River in northeast Japan. First, the system was applied to one snow season (2002-2003), obtaining an optimised Cfsnow of 0.0007 m-1. For validation purposes, the optimised Cfsnow was implemented to correct snowfall in 2004, 2002 and 2001. Overall, the system was effective, implying improvements in correlation of simulated versus observed discharge and snow cover. The 4 yr mean of basin-average snowfall for the corrected spatial snowfall distribution was 1160 mm (780 mm before correction). Execution of sensitivity runs against other model input and parameters indicated that Cfsnow could be affected by uncertainty in shortwave radiation and setting of the threshold air temperature parameter. Our approach is suitable to correct snowfall and estimate its distribution in poorly gauged basins, where elevation dependence of snowfall amount is strong.

  3. Rapid heat-flowing surveying of geothermal areas, utilizing individual snowfalls as calorimeters

    USGS Publications Warehouse

    White, Donald E.

    1969-01-01

    Local differences in rate of heat transfer in vapor and by conduction through the ground in hot spring areas are difficult and time-consuming to measure quantitatively. Individual heavy snowfalls provide a rapid low-cost means of measuring total heat flow from such ground. After a favorable snowfall (heavy, brief duration, little wind, air temperature near 0°C), contacts between snow-covered and snow-free ground are mapped on a suitable base. Each mapped contact, as time elapses after a specific snowfall, is a heat-flow contour representing a decreasing rate of flow. Calibration of each mapped contact or snow line is made possible by the fact that snow remains on insulated surfaces (such as the boardwalks of Yellowstone's thermal areas) long after it has melted on adjacent warm ground. Heat-flow contours mapped to date range from 450 to 5500 ?cal/cm2 sec, or 300 to 3700 times the world average of conductive heat flow. The very high rates of heat flow (2000 to > 10,000 ?cal/cm2 sec) are probably too high, and the lower heat flows determinable by the method (2 sec) may be too low. Values indicated by the method are, however, probably within a factor of 2 of the total conductive and convective heat flow. Thermal anomalies from infrared imagery are similar in shape to heat-flow contours of a test area near Old Faithful geyser. Snowfall calorimetry provides a rapid means for evaluating the imagery and computer-derived products of the infrared data in terms of heat flow.

  4. Strong fluctuation theory for scattering, attenuation, and transmission of microwaves through snowfall

    NASA Technical Reports Server (NTRS)

    Jin, Y.-Q.; Kong, J. A.

    1985-01-01

    The strong fluctuation theory is applied to the study of the atmospheric snowfall which is modeled as a layer of random discrete-scatterers medium. As functions of size distribution, fractional volume, and radius of scatterers, the relationship is illustrated between the reflectivity factor and precipitation rate, the attenuation of the centimeter and millimeter waves, and the line-of-sight transmission of coherent and incoherent wave components. The theoretical results are shown to match favorably with experimental data.

  5. A Physical Model to Determine Snowfall over Land by Microwave Radiometry

    NASA Technical Reports Server (NTRS)

    Skofronick-Jackson, G.; Kim, M.-J.; Weinman, J. A.; Chang, D.-E.

    2003-01-01

    Because microwave brightness temperatures emitted by snow covered surfaces are highly variable, snowfall above such surfaces is difficult to observe using window channels that occur at low frequencies (v less than 100 GHz). Furthermore, at frequencies v less than or equal to 37 GHz, sensitivity to liquid hydrometeors is dominant. These problems are mitigated at high frequencies (v greater than 100 GHz) where water vapor screens the surface emission and sensitivity to frozen hydrometeors is significant. However the scattering effect of snowfall in the atmosphere at those higher frequencies is also impacted by water vapor in the upper atmosphere. This work describes the methodology and results of physically-based retrievals of snow falling over land surfaces. The theory of scattering by randomly oriented dry snow particles at high microwave frequencies appears to be better described by regarding snow as a concatenation of equivalent ice spheres rather than as a sphere with the effective dielectric constant of an air-ice mixture. An equivalent sphere snow scattering model was validated against high frequency attenuation measurements. Satellite-based high frequency observations from an Advanced Microwave Sounding Unit (AMSU-B) instrument during the March 5-6, 2001 New England blizzard were used to retrieve snowfall over land. Vertical distributions of snow, temperature and relative humidity profiles were derived from the Pennsylvania State University-National Center for Atmospheric Research (PSU-NCAR) fifth-generation Mesoscale Model (MM5). Those data were applied and modified in a radiative transfer model that derived brightness temperatures consistent with the AMSU-B observations. The retrieved snowfall distribution was validated with radar reflectivity measurements obtained from the National Oceanic and Atmospheric Administration (NOAA) National Weather Service (NWS) ground-based radar network.

  6. GROUND BASED REMOTE SENSING OF SNOWFALL THROUGH ACTIVE AND PASSIVE SENSOR SYNERGY

    Microsoft Academic Search

    S. Kneifel; U. Loehnert; A. Battaglia; S. Crewell; M. Hagen; L. Hirsch

    2009-01-01

    This contribution presents first results of the DFG-funded research project TOSCA - ``Towards an Optimal estimation based Snow Characterization Algorithm''. Although snow is the predominant type of precipitation in the sub-polar and polar latitudes, not many reliable remote-sensing methods of determining the vertical distributions of micro-physical snowfall parameters (i.e. snow mass density, snow crystal size and type) today exist. These

  7. Total Ozone Mapping Spectrometer (TOMS) observations of increases in Asian aerosol in winter from 1979 to 2000

    Microsoft Academic Search

    Steven T. Massie; Omar Torres; Steven J. Smith

    2004-01-01

    Emission inventories indicate that the largest increases in SO emissions have occurred in Asia during the last 20 years. By inference, largest increases in aerosol, produced primarily by the conversion of SO to sulfate, should have occurred in Asia during the same time period. Decadal changes in regional aerosol optical depths are calculated by analyzing Total Ozone Mapping Spectrometer (TOMS)

  8. A Physical Model to Estimate Snowfall over Land using AMSU-B Observations

    NASA Technical Reports Server (NTRS)

    Kim, Min-Jeong; Weinman, J. A.; Olson, W. S.; Chang, D.-E.; Skofronick-Jackson, G.; Wang, J. R.

    2008-01-01

    In this study, we present an improved physical model to retrieve snowfall rate over land using brightness temperature observations from the National Oceanic and Atmospheric Administration's (NOAA) Advanced Microwave Sounder Unit-B (AMSU-B) at 89 GHz, 150 GHz, 183.3 +/- 1 GHz, 183.3 +/- 3 GHz, and 183.3 +/- 7 GHz. The retrieval model is applied to the New England blizzard of March 5, 2001 which deposited about 75 cm of snow over much of Vermont, New Hampshire, and northern New York. In this improved physical model, prior retrieval assumptions about snowflake shape, particle size distributions, environmental conditions, and optimization methodology have been updated. Here, single scattering parameters for snow particles are calculated with the Discrete-Dipole Approximation (DDA) method instead of assuming spherical shapes. Five different snow particle models (hexagonal columns, hexagonal plates, and three different kinds of aggregates) are considered. Snow particle size distributions are assumed to vary with air temperature and to follow aircraft measurements described by previous studies. Brightness temperatures at AMSU-B frequencies for the New England blizzard are calculated using these DDA calculated single scattering parameters and particle size distributions. The vertical profiles of pressure, temperature, relative humidity and hydrometeors are provided by MM5 model simulations. These profiles are treated as the a priori data base in the Bayesian retrieval algorithm. In algorithm applications to the blizzard data, calculated brightness temperatures associated with selected database profiles agree with AMSU-B observations to within about +/- 5 K at all five frequencies. Retrieved snowfall rates compare favorably with the near-concurrent National Weather Service (NWS) radar reflectivity measurements. The relationships between the NWS radar measured reflectivities Z(sub e) and retrieved snowfall rate R for a given snow particle model are derived by a histogram matching technique. All of these Z(sub e)-R relationships fall in the range of previously established Z(sub e)-R relationships for snowfall. This suggests that the current physical model developed in this study can reliably estimate the snowfall rate over land using the AMSU-B measured brightness temperatures.

  9. Synoptic variability of extreme snowfall in the St. Elias Mountains, Yukon, Canada

    NASA Astrophysics Data System (ADS)

    Andin, Caroline; Zdanowicz, Christian; Copland, Luke

    2015-04-01

    Glaciers in the Wrangell and St. Elias Mountains (Alaska and Yukon) are presently experiencing some of the highest regional wastage rates worldwide. While the effect of regional temperatures on glacier melt rates in this region has been investigated, comparatively little is known about how synoptic climate variations, for example in the position and strength of the Aleutian Low, modulate snow accumulation on these glaciers. Such information is needed to accurately forecast future wastage rates, glacier-water resource availability, and contributions to sea-level rise. Starting in 2000, automated weather stations (AWS) were established in the central St-Elias Mountains (Yukon) at altitudes ranging from 1190 to 5400 m asl, to collect climatological data in support of glaciological research. These data are the longest continuous year-round observations of surface climate ever obtained from this vast glaciated region. Here we present an analysis of snowfall events in the icefields of the St-Elias Mountains based on a decade-long series of AWS observations of snow accumulation. Specifically, we investigated the synoptic patterns and air mass trajectories associated with the largest snowfall events (> 25 cm/12 hours) that occurred between 2002 and 2012. Nearly 80% of these events occurred during the cold season (October-March), and in 74 % of cases the precipitating air masses originated from the North Pacific south of 50°N. Zonal air mass advection over Alaska, or from the Bering Sea or the Arctic Ocean, was comparatively rare (20%). Somewhat counter-intuitively, dominant surface winds in the St. Elias Mountains during high snowfall events were predominantly easterly, probably due to boundary-layer frictional drag and topographic funneling effects. Composite maps of sea-level pressure and 700 mb winds reveal that intense snowfall events between 2002 and 2012 were associated with synoptic situations characterized by a split, eastwardly-shifted or longitudinally-stretched Aleutian Low (AL) having an easternmost node near the Kenai Peninsula, conditions that drove a strong southwesterly upper airstream across the Gulf of Alaska towards the coast. Situations with a single-node, westerly-shifted AL were comparatively rare. The spatial configuration of the synoptic AL pressure pattern appears to play a greater role in determining snowfall amount in the central St. Elias Mountains than do pressure anomalies within the AL. The estimated snowfall gradient from coastal Alaska to the central St. Elias Mountains during intense snowfall events averaged +2.0 ± 0.7 mm/km (SWE), while the continental-side gradient from the mountains towards the Yukon plateau averaged -3.3 ± 0.9 mm/km (SWE). The findings presented here can better constrain the climatic interpretation of long proxy records of snow accumulation variations developed from glacier cores drilled in the St. Elias Mountains or nearby regions.

  10. Does undersowing winter wheat with a cover crop increase competition for resources and is it compatible with high yield?

    Microsoft Academic Search

    D. Picard; M. Ghiloufi; P. Saulas; S. de Tourdonnet

    2010-01-01

    The sustainability of cropping systems can be increased by introducing a cover crop, provided that the cover crop does not reduce the cash crop yield through competition. The cover crop may be sown at the same time as a cash crop in the crop rotation. We carried out an experiment in 1999–2000 and 2000–2001 in the Paris Basin, to analyze

  11. Winter Storms

    NSDL National Science Digital Library

    1996-01-01

    This site offers general background about winter storms as well as interactive activities to teach visitors about these storms. It also offers a teachers guide to using this site and links to other weather-related pages. There are four main topics: All About Winter Storms, Interactive Weather Maker, Interactive Winter Storm Timeline, and Ask Our Winter Storm Expert. All About Winter Storms gives general background information an a glossary of weather terms. The Weather Maker offers students a chance to control the weather through a simulation in which they affect the weather by changing variables such as humidity, equatorward temperature, and polarward temperature. The Storm Timeline offers students a chance to move up and down the timeline to learn about past winter storms. In Ask the Expert, students can email their questions to a winter storm expert and have them answered. This section also gives a brief biography of the expert.

  12. River chloride trends in snow-affected urban watersheds: increasing concentrations outpace urban growth rate and are common among all seasons.

    PubMed

    Corsi, Steven R; De Cicco, Laura A; Lutz, Michelle A; Hirsch, Robert M

    2015-03-01

    Chloride concentrations in northern U.S. included in this study have increased substantially over time with average concentrations approximately doubling from 1990 to 2011, outpacing the rate of urbanization in the northern U.S. Historical data were examined for 30 monitoring sites on 19 streams that had chloride concentration and flow records of 18 to 49 years. Chloride concentrations in most studied streams increased in all seasons (13 of 19 in all seasons; 16 of 19 during winter); maximum concentrations occurred during winter. Increasing concentrations during non-deicing periods suggest that chloride was stored in hydrologic reservoirs, such as the shallow groundwater system, during the winter and slowly released in baseflow throughout the year. Streamflow dependency was also observed with chloride concentrations increasing as streamflow decreased, a result of dilution during rainfall- and snowmelt-induced high-flow periods. The influence of chloride on aquatic life increased with time; 29% of sites studied exceeded the concentration for the USEPA chronic water quality criteria of 230 mg/L by an average of more than 100 individual days per year during 2006-2011. The rapid rate of chloride concentration increase in these streams is likely due to a combination of possible increased road salt application rates, increased baseline concentrations, and greater snowfall in the Midwestern U.S. during the latter portion of the study period. PMID:25514764

  13. Summer snowfall on the Greenland Ice Sheet: a study with the updated regional climate model RACMO2.3

    NASA Astrophysics Data System (ADS)

    Noël, B.; van de Berg, W. J.; van Meijgaard, E.; Kuipers Munneke, P.; van de Wal, R. S. W.; van den Broeke, M. R.

    2015-02-01

    We discuss Greenland ice sheet (GrIS) surface mass balance (SMB) differences between the updated polar version of the regional climate model RACMO2.3 and the previous version RACMO2.1. Among other revisions, the updated model includes an adjusted rainfall-to-snowfall conversion, producing exclusively snowfall under freezing conditions; this especially favours snowfall in summer when upper air temperatures reach the freezing point. Summer snowfall in the ablation zone of the GrIS has a pronounced effect on melt rates, affecting modelled GrIS SMB in two ways. By covering relatively dark ice with highly reflective fresh snow, these summer snowfall have the potential to locally reduce melt rates in the ablation zone of the GrIS through a snow-albedo-melt feedback. At larger scales, SMB changes are driven by differences in orographic precipitation following a shift in large-scale circulation, in combination with enhanced moisture to precipitation conversion for warm to moderately cold conditions. A detailed comparison of model output with long-term observations from automatic weather stations and ablation stakes in west Greenland shows that the model update generally improves the simulated SMB-elevation gradient as well as the representation of the surface energy balance, although significant biases remain.

  14. Deuterium content of snow as an index to winter climate in the sierra nevada area.

    PubMed

    Friedman, I; Smith, G I

    1972-05-19

    The winter of 1968-69 produced two to three times the amount of precipitation in the Sierra Nevada area, California and Nevada, as the winter of 1969-70. The deuterium content in snow cores collected at the end of each winter at the same sites, which represents the total snowfall of each interval, shows a depletion in 1968-69 of approximately 20 per mil. The higher snowfall in 1968-69 and the depletion of deuterium can be explained by an uncommonly strong westward flow of cold air over and down the western slopes of the Sierras, which interacted with an eastward flow of moist Pacific air that overrode and mixed with the cold air; this resulted in precipitation that occurred in greater than normal amounts and at a lower than normal temperature. Pluvial periods of the Pleistocene may have had the same shift in air-mass trajectory as the wet 1968-69 year. Snow cores collected in the norrmal 1970-71 winter have deuterium concentrations that resemble those of the normal 1969-70 winter. Small and nonsystematic differences in samples from these two normal winters are due to variations in climatic character as well as to factors inherent in the sampling sites. PMID:17795407

  15. Thresholds of Passive Microwave Snowfall Detection Determined Using A-Train Observations

    NASA Astrophysics Data System (ADS)

    Munchak, S. J.; Skofronick Jackson, G.; Johnson, B. T.

    2011-12-01

    In this study we explore a database of CloudSat+AMSU-B coincident overpasses to determine the minimum threshold of passive microwave detection of snowfall using the high-frequency channels available on GMI. Using the Advanced Infrared Sounder (AIRS) temperature and water vapor profiles along with a surface emissivity database developed from AMSU-B and MHS observations, clear-sky radiances are simulated and compared to AMSU-B observed radiances for all profiles with a maximum temperature less than 271 K. The ability of a scattering signal (observed brightness tempertaure colder than clear-sky brightness temperature by a threshold T) to detect snowfall (CloudSat reflectivity greater than threshold Z) is quantified using the Heidke Skill Score. The 183+/-1 and 183+/-3 GHz channels have the highest skill scores, while those channels that are sensitive to the surface (89, 150 and 183+/-7 GHz) have zero or even negative skill (depending on Z and T), implying that an emission signal (presumably from cloud water) is as good or better for detecting precipitation than a scattering signal. These results emphasize the need for proper characterization of surface emissivity and adequate representation of cloud water in cold season precipitation profiles that form the databases used for Bayesian retrievals from GMI and other GPM constellation radiometers.

  16. Remote Measurements of Snowfalls in Wakasa Bay, Japan with Airborne Millimeter- wave Imaging Radiometer and Cloud Radar

    NASA Technical Reports Server (NTRS)

    Wang, J. R.; Austin, R.; Liu, G. S.; Racette, P. E.

    2004-01-01

    In this paper we explore the application of combined millimeter-wave radar and radiometry to remotely measure snowfall. During January-February of 2003, a field campaign was conducted with the NASA P-3 aircraft in Wakasa Bay, Japan for the validation of the AMSRE microwave radiometer on board the Aqua satellite. Among the suite of instruments-on board the P-3 aircraft were the Millimeter-wave Imaging Radiometer (MIR) from the NASA Goddard Space Flight Center and the 94 GHz Airborne Cloud Radar (ACR) which is co-owned and operated by NASA Jet Propulsion Laboratory/University of Massachusetts. MIR is a total power, across-track scanning radiometer that measures radiation at the frequencies of 89, 150, 183.3 +/- 1, 183.3 +/- 3, 183.3 +/-7, 220, and 340 GHz. The MIR has flown many successful missions since its completion in May 1992. ACR is a newer instrument and flew only a few times prior to the Wakasa Bay deployment. These two instruments which are particularly well suited for the detection of snowfall functioned normally during flights over snowfall and excellent data sets were acquired. On January 14, 28, and 29 flights were conducted over snowfall events. The MIR and ACR detected strong signals during periods of snowfall over ocean and land. Results from the analysis of these concurrent data sets show that (1) the scattering of millimeter-wave radiation as detected by the MIR is strongly correlated with ACR radar reflectivity profiles, and (2) the scattering is highly frequency-dependent, the higher the frequency the stronger the scattering. Additionally, the more transparent channels of the MIR (e.g., 89, 150, and 220 GHz) are found to display ambiguous signatures of snowfall because of their exposure to surface features. Thus, the snowfall detection and retrievals of snowfall parameters, such as the ice water path (IWP) and median mass diameter (D(me)) are best conducted at the more opaque channels near 183.3 GHz and 340 GHz. Retrievals of IWP and D(me) using the MIR measurements at 183.3 and 340 GHZ are currently in progress, and the results will be compared with those derived from the ACR reflectivity profiles. Implication from this comparison will be discussed.

  17. Winter Wonderlands

    ERIC Educational Resources Information Center

    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

  18. Winter Ecology.

    ERIC Educational Resources Information Center

    Birkeland, Karl W.; Halfpenny, James C.

    1987-01-01

    Discusses some of the ecological variables involved with plant and animal survival during the winter months. Addresses the effects of changing climatic conditions on habitats, foot-loading indexes, and the overall concept of adaptation. Provides some simple teaching activities dealing with winter survival. (TW)

  19. Surviving Winter

    NSDL National Science Digital Library

    2010-11-17

    In this lesson designed to enhance literacy skills, students learn about the varied physical and behavioral adaptations that animals rely on to help them survive changing environmental conditions, such as the arrival of winter.

  20. Winter Games.

    ERIC Educational Resources Information Center

    Tarbuth, Lawson, Comp.

    Educators may find activities for indoor and outdoor winter programs in the games of the traditional Eskimo. These games are dominated by few-step operations and low level structural organization. For the most part they are quickly organized, begun, terminated, and ready to be recommenced. All types of games can be found, including quiet ones,…

  1. Winter Depression

    NSDL National Science Digital Library

    A U.K. psychologist has developed a complex mathematical formula using seven variables to predict winter's emotional low point. The good news is the worst day of the year was last week; nonetheless, seasonal depression remains a problem for many. The first link (1) is to an article about the equation worked out by Dr. Cliff Arnall, who specializes in seasonal disorders at the University of Cardiff, Wales. The second link is to a WebMD page (2) about winter depression, often referred to as Seasonal Affective Disorder (SAD). The next link (3) is to a recent news story about the results of a five-year study that found, rather than antidepressant drug therapy or air ionizers, light box therapy is the best remedy for the seasonal condition. The fourth link is to a set of Frequently Asked Questions (4) about SAD offered by Columbia Presbyterian Medical Center in New York City. The fifth link, to the Winter Depression Research Group at the University of Tromso in Norway(5), explains why Norway is a natural SAD research laboratory. The next link is to a international portal site (6) maintained by medical professionals and researchers in the field of light therapy and biological rhythms. The final webpage(7), from Psychology Today, compares the symptoms of winter depression with summer depression.

  2. Winter Math

    NSDL National Science Digital Library

    Wendy Petti

    2009-01-13

    This article by Wendy Petti presents ideas and math activities for students to explore snowflakes and winter by making estimates, by counting and by measuring. Data collection, displays and analysis ideas are also included. A list of online resources with their links provides more wintry ideas for the classroom.

  3. Rainfall and Snowfall Observations by the Airborne Dual-frequency Precipitation Radar during the Wakasa Bay Experiment

    NASA Technical Reports Server (NTRS)

    Tanelli, Simone; Im, Eastwood; Durden, Stephen L.; Meagher, Jonathan P.

    2004-01-01

    Radar data obtained through the NASA/JPL Airborne Precipitation Radar APR-2 during the Wakasa Bay Experiment in January/February 2003 were processed to obtain calibrated reflectivity measurements, rainfall/snowfall velocity measurements, classification of the surface type and detection of the boundaries of the melting layer of precipitation. In this paper the processing approach is described together with an overview of the resulting data quality and known issues.

  4. Winter Storm

    NSDL National Science Digital Library

    Miss Liz

    2010-05-26

    This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. In general, when are winds formed? 2. How can you get them to stop, when they are blowing? 3. What tends happens when there is a large difference between the temperatures? 4. What happens when there ...

  5. Winter Storm

    NSDL National Science Digital Library

    Miss Smith

    2010-09-27

    This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What usually happens when there is a large difference between the temperatures? ...

  6. Winter Storms

    NSDL National Science Digital Library

    Mr. Sappa

    2010-05-26

    This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What usually happens when there is a large difference between the temperatures? 4. What happens when there ...

  7. Winter Storm

    NSDL National Science Digital Library

    Ashley Schilling

    2010-05-26

    This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What usually happens when there is a large difference between the ...

  8. USF MAGAZINE | WINTER 200932 USF MAGAZINE | WINTER 2009 33 Wherehaveallthe

    E-print Network

    Rohr, Jason

    USF MAGAZINE | WINTER 200932 USF MAGAZINE | WINTER 2009 33 Wherehaveallthe USF Biologist Jason Rohr- phibians--and suppressing amphibian immune systems." USF MAGAZINE | WINTER 200934 USF MAGAZINE | WINTER

  9. Lessons from the unusual impacts of an abnormal winter in the USA

    NASA Astrophysics Data System (ADS)

    Changnon, Stanley A.; Changnon, David

    2005-09-01

    Economic impacts from the near record warm and snow-free winter of 2001 2 in the United States were assessed to ascertain their dimensions and relevance to issues like climate prediction and climate change. Unusual impacts resulted and embraced numerous sectors (heating/energy use, construction, tourism, insurance, government, and retail sales). Many outcomes were gains/benefits totalling 19.6 billion, with losses of 8.2 billion. Some economists identified the sizable positive impacts as a factor in the nation's recovery from an on-going recession stemming from the terrorist attacks on 11 September 2001. Understanding the impacts of such a winter reveals how climate predictions of such conditions could have great utility in minimising the losses and maximising the gains. The results also have relevance to the global warming issue since most climate models project future average winter temperature and snowfall conditions in the United States to be similar to those experienced in 2001 2.

  10. Evaluating Snowfall Detectability of NASA CloudSat with NOAA/NSSL Ground Radar-Based National Multi-sensor Mosaic QPE (NMQ)

    NASA Astrophysics Data System (ADS)

    Chen, S.; Cao, Q.; Hong, Y.; Gourley, J. J.; Hu, J.

    2013-12-01

    NASA CloudSat, carrying the first space-borne Cloud Profiling Radar (CPR), is the first satellite that provides scientific communities with global snowfall observations. The accuracy of snowfall observation and quantification at middle and high latitude area is directly correlated with the liability of satellite-based precipitation estimates. However, up-to-date there is not systematic evaluation of its snowfall detectability at regional and global scale. Validation and evaluation of CPR's capability of snowfall detection is still needed in satellite precipitation communities. The NOAA/NSSL ground radar-based National Mosaic and multi-sensor Quantitative Precipitation Estimates (QPE) (NMQ or Q2) provides the high spatiotemporal resolution (1km/5min) 2-dimensional (2D) multi-suites precipitation products as well as 3-dimensional (3D) products. Such high-resolution QPE products offer an ideal alternate to evaluate satellite-based observations and products. In this paper, the CloudSat-CPR's detectability of falling snow is systematically evaluated using NMQ-Q2 snowfall products (i.e., solid snowfall precipitation identification) over the CONUS from January 2009 to December 2012. Spatial and temporal matching is applied to obtain the most matched dataset from both observations considering their differences in spatiotemporal resolution. The evaluation results offer the insights into the performance of CPR in detecting falling snow and also demonstrate its great potential in improving the solid precipitation (snowfall) in the mid-high latitude area and high-altitude area (e.g. the Tibetan plateau). A synthetic approach of incorporating the ground-radar-based NMQ products for evaluating and integrating into spaceborne radar observations will be highly expected with the launch of Global Precipitation Measurement in 2014.

  11. Winter snow

    NSDL National Science Digital Library

    Lori Peterson

    2009-09-28

    This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. 1. What do you already know about the weather? 2. How does the weather effect you daily? Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What ...

  12. Increases in platelet and red cell counts, blood viscosity, and arterial pressure during mild surface cooling: factors in mortality from coronary and cerebral thrombosis in winter

    Microsoft Academic Search

    W R Keatinge; S R Coleshaw; F Cotter; M Mattock; M Murphy; R Chelliah

    1984-01-01

    Six hours of mild surface cooling in moving air at 24 degrees C with little fall in core temperature (0.4 degree C) increased the packed cell volume by 7% and increased the platelet count and usually the mean platelet volume to produce a 15% increase in the fraction of plasma volume occupied by platelets. Little of these increases occurred in

  13. Ground Based In-situ Measurements of Snowfall with a 2D-Video Distrometer on Mt. Zugspitze, Germany

    NASA Astrophysics Data System (ADS)

    Bernauer, F.; Schwinzerl, M.; Huerkamp, K.; Tschiersch, J.

    2014-12-01

    Measuring micro physical properties of snowfall is a challenging task that is essential in many areas of research. Some examples are wet deposition of atmospheric pollution, electromagnetic wave propagation during snowfall, avalanche and glacier research. In recent years the 2D-video-disdrometer (2DVD, Joanneum Research) has been established for ground based in-situ rain measurements. The 2DVD is an optical device that delivers shape, size and velocity information derived from a front and a side view taken from each hydrometeor falling through the sensitive area. In case of snowfall the user has to be aware of certain di ffculties that are addressed in this contribution.For our study we installed the 2DVD at the Environmental Research Station Schneefernerhaus (UFS) on Mt. Zugspitze, Germany (2650m a.s.l.). We analyzed a data set consisting of 150 days with snowfall and 70 man made observations including a classif cation according to the World Meteorologic Organization code 4677. We compared measured micro physical parameters with man made observations of shape, degree of riming and humidity of single hydrometeors and correlated the precipitation rate and total water equivalent from the 2DVD with measurements of a weighing precipitation sensor (in cooperation with the Institute for Geophysics and Meteorology, University Cologne).We show that the implementation of a matching algorithm that fi nds appropriate pairs of pictures is essential for reliable measurement results. Without the improved matching algorithm the data sets contain about 80% of hydrometeors with extreme geometries and velocities. Applying the new matching algorithm 2DVD measurements and man made observations fi t in most of the cases of calm winds. Simply summing up hydrometeor volumes derived from the measured apparent diameters leads to an overestimation of water equivalent by a factor of 10. The measurement of water equivalent is improved significantly with the use of a size-density relation for snow flakes.With the mentioned improvements in the analysis algorithm, the 2DVD is a suitable instrument for micro- and macroscopic snow event characterization. Nevertheless ground based in-situ measurement of snow properties stays a diff cult task, regarding the influence of wind fields especially at alpine mountain stations.

  14. Greenland Ice Sheet: Increased coastal thinning

    Microsoft Academic Search

    W. Krabill; E. Hanna; P. Huybrechts; W. Abdalati; J. Cappelen; B. Csatho; E. Frederick; S. Manizade; C. Martin; J. Sonntag; R. Swift; R. Thomas; J. Yungel

    2004-01-01

    Repeated laser-altimeter surveys and modelled snowfall\\/summer melt show average ice loss from Greenland between 1997 and 2003 was 80 +\\/- 12 km3 yr-1, compared to about 60 km3 yr-1 for 1993\\/4-1998\\/9. Half of the increase was from higher summer melting, with the rest caused by velocities of some glaciers exceeding those needed to balance upstream snow accumulation. Velocities of one

  15. Greenland Ice Sheet: Increased coastal thinning

    Microsoft Academic Search

    W. Krabill; E. Hanna; P. Huybrechts; W. Abdalati; J. Cappelen; B. Csatho; E. Frederick; S. Manizade; C. Martin; J. Sonntag; R. Swift; R. Thomas; J. Yungel

    2004-01-01

    Repeated laser-altimeter surveys and modelled snowfall\\/summer melt show average ice loss from Greenland between 1997 and 2003 was 80 ± 12 km3 yr?1, compared to about 60 km3 yr?1 for 1993\\/4–1998\\/9. Half of the increase was from higher summer melting, with the rest caused by velocities of some glaciers exceeding those needed to balance upstream snow accumulation. Velocities of one

  16. Winter temperature variations over the middle and lower reaches of the Yangtze River since 1736 AD

    NASA Astrophysics Data System (ADS)

    Hao, Z.-X.; Zheng, J.-Y.; Ge, Q.-S.; Wang, W.-C.

    2012-06-01

    We present statistically reconstructed mean annual winter (December-February) temperatures from the middle and lower reaches of the Yangtze River (24° N-34° N, 108° E-123° E within mainland China) extending back to 1736. The reconstructions are based on information regarding snowfall days from historical documents of the Yu-Xue-Fen-Cun archive recorded during the Qing Dynasty (1644-1911). This information is calibrated with regional winter temperature series spanning the period from 1951 to 2007. The gap from 1912 to 1950 is filled using early instrumental observations. With the reference period of 1951-2007, the 18th century was 0.76 °C colder, and the 19th century was 1.18 °C colder. However, since the 20th century, the climate has been in a warming phase, particularly in the last 30 yr, and the mean temperature from 1981 to 2007 was 0.25 °C higher than that of the reference period of 1951-2007, representing the highest temperatures of the past 300 yr. Uncertainty existed for the period prior to 1900, and possible causes of this uncertainty, such as physical processes involved in the interaction between temperature and snowfall days and changing of observers, are discussed herein.

  17. Simulation of Annual Snowfall over Colorado using a High Resolution Mesoscale Model and some Impacts of Climate Change using the Pseudo Climate Simulation Method

    NASA Astrophysics Data System (ADS)

    Rasmussen, R.; Grubisic, V.

    2010-09-01

    Snowpack is the most important water resource in the Western United States, and widely regarded as the most vulnerable. It is thus critical to provide water managers the most accurate estimate of how that resource will evolve as the climate changes, including its societal impact. The headwaters region of Colorado that includes, among others, the Colorado, Platte, Rio Grande and Arkansas Rivers, is one of the key source regions for water in the Southwest as ~85% of the streamflow for the Colorado River comes from snowmelt in this region. This region is a particularly difficult area for global climate models to properly handle, with inconsistent snowpack trends in this region from different models despite consistent predictions of temperature increases in this region from all climate models from both the 3rd and 4th IPCC reports (2001, 2007). Observations over the past 50 years in the upper Colorado River basin also reflect the same increasing temperature trend but show no identifiable trends in snowpack (Edwards and Redmond, 2005, Colorado and California Water Users Conference publication). A recent analysis of the 2007 IPCC 4th Assessment global models by Hoerling and Eischeid (2006,Southwest Hydrology) indicates that the combination of increased temperature and weak to no trends in snowfall will produce unprecedented drought conditions over the next 50 years in the Southwest due to a strong increase in evapotranspiration associated with the increased temperature. While the above predictions based on global models indicate dire consequences for the Southwest, it should also be noted that the AR4 indicates that global models typically perform poorly in mountainous regions due to the poor depiction of terrain as well as significant uncertainty in detailed hydrometeorological processes (i.e. cloud/precipitation microphysics, embedded convection and cloud-scale circulations, snowpack and snow ablation, and runoff generation in complex terrain) that currently limit model simulation skill. Colorado's headwaters region is dominated by high altitude snow melt, so climate assessments in this region using global models are particularly uncertain. However, simple increases in model resolution without clearer understanding and representation of hydroclimatic processes controlling water resources will not be sufficient for improving model performance. It is therefore critical to examine climate impacts in this region using detailed coupled atmosphere-hydrology models in order to more realistically simulate precipitation, sublimation, and runoff processes, as well as their impact on managed water systems. This paper will present results of annual snowfall, snow/rain fraction, and snowpack over Colorado based on high resolution simulations of the Weather Research and Forecast (WRF) model running at 2 km horizontal resolution using the North American Regional Reanalysis (NARR) as initial and lateral boundary conditions. Four retrospective years will be shown. Results from four Pseudo Climate simulations (Hara et al. 2008) using the four retrospective runs as the baseline will also be presented. These simulations will be forced by the mean monthly climate signal difference between current (1995 - 2004) and 2045-2055 mean conditions. The NCAR CCSM3 A1B AR4 climate runs with 6 hourly output will be used for the current and future climate model forcings.

  18. Weak precipitation, warm winters and springs impact glaciers of south slopes of Mt. Everest (central Himalaya) in the last 2 decades (1994-2013)

    NASA Astrophysics Data System (ADS)

    Salerno, F.; Guyennon, N.; Thakuri, S.; Viviano, G.; Romano, E.; Vuillermoz, E.; Cristofanelli, P.; Stocchi, P.; Agrillo, G.; Ma, Y.; Tartari, G.

    2015-06-01

    Studies on recent climate trends from the Himalayan range are limited, and even completely absent at high elevation (> 5000 m a.s.l.). This study specifically explores the southern slopes of Mt. Everest, analyzing the time series of temperature and precipitation reconstructed from seven stations located between 2660 and 5600 m a.s.l. during 1994-2013, complemented with the data from all existing ground weather stations located on both sides of the mountain range (Koshi Basin) over the same period. Overall we find that the main and most significant increase in temperature is concentrated outside of the monsoon period. Above 5000 m a.s.l. the increasing trend in the time series of minimum temperature (+0.072 °C yr-1) is much stronger than of maximum temperature (+0.009 °C yr-1), while the mean temperature increased by +0.044 °C yr-1. Moreover, we note a substantial liquid precipitation weakening (-9.3 mm yr-1) during the monsoon season. The annual rate of decrease in precipitation at higher elevations is similar to the one at lower elevations on the southern side of the Koshi Basin, but the drier conditions of this remote environment make the fractional loss much more consistent (-47% during the monsoon period). Our results challenge the assumptions on whether temperature or precipitation is the main driver of recent glacier mass changes in the region. The main implications are the following: (1) the negative mass balances of glaciers observed in this region can be more ascribed to a decrease in accumulation (snowfall) than to an increase in surface melting; (2) the melting has only been favoured during winter and spring months and close to the glaciers terminus; (3) a decrease in the probability of snowfall (-10%) has made a significant impact only at glacier ablation zone, but the magnitude of this decrease is distinctly lower than the observed decrease in precipitation; (4) the decrease in accumulation could have caused the observed decrease in glacier flow velocity and the current stagnation of glacier termini, which in turn could have produced more melting under the debris glacier cover, leading to the formation of numerous supraglacial and proglacial lakes that have characterized the region in the last decades.

  19. Winter cover biomass production and soil penetrability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Winter cover crops can benefit production systems in the southeastern US. Winter cover crops, such as rye (Secale cereale) can reduce weed pressure, increase water infiltration, and improve soil quality over a long period of time. Although several studies have focused on the effects of having a wi...

  20. Causes of the f region winter anomaly

    SciTech Connect

    Torr, D.G.; Torr, M.R.; Richards, P.G.; Richards, P.G.

    1980-05-01

    Measurements made by the Atmosphere Explorer satellites are used to determine the causes of the f-region winter anomaly, i.e., seasonal variations which result in peak electron densities which are larger in winter than in summer. It is found that for the data examined there are 3 causes of the winter anomaly. 1) Seasonal changes in neutral composition; 2) an increase in the vibrational temperature of N/sub 2/ and hence in the rate coefficient for the reaction O/sup +/(/sup 4/S)+N/sub 2/..-->..NO/sup +/+N; 3) an increase in winter in the production of O/sup +/(/sup 4/S) due to enhanced electron quenching of O/sup +/(D). The presence of vibrational excitation is inferred from an increase in the rate coefficient for the reaction O/sup +/+N/sub 2/..-->../sup kl/ NO/sup +/+N from winter to summer at heights above 260 km. We quantitatively demonstrate that the initial increase in electron density produced in winter by causes (1) and (2) results in an increase in the quenching of O/sup +/(/sup 2/D) thereby enhancing the source of O/sup +/(/sup 4/S) ions. We estimate that causes (1) to (3) account for approx.55%, approx.20% and approx.25% respectively of the seasonal change in O/sup +/(/sup 4/S) from summer to winter at solar minimum.

  1. Winter Storms For More Information

    E-print Network

    -related brochures. You can find more information on flash flooding in the Floods... The Awesome Power brochure site http://www.nws.noaa.gov/om/water/ahps/ pdfs/Floodsbrochure_02_06.pdf. To find additional materials or sleet, heavy snowfall and cold temperatures. · People can become trapped at home or in a car, without

  2. LETTER doi:10.1038/nature11616 Increased future ice discharge from Antarctica owing

    E-print Network

    Levermann, Anders

    LETTER doi:10.1038/nature11616 Increased future ice discharge from Antarctica owing to higher snowfall over Antarctica, which would provide a direct offset of the future contribution to global sea Antarctica1,6 and thus in the ultimate fate of the precipitation- deposited ice mass. Here we show

  3. Partitioning and Transport of Organochlorine Pollutants in the Arctic: From Snowfall to Snowmelt

    NASA Astrophysics Data System (ADS)

    Rowland, G. A.; Torres, A.; Grannas, A. M.

    2009-12-01

    Volatile and semi-volatile organochlorine (OCs) compounds such as dieldrin, endosulfan and PCBs have frequently been identified as pollutants in remote polar regions, far from their anthropogenic sources. Bioaccumulation of these compounds has been previously documented and poses a potential threat to the health of individuals in Arctic subsistence communities as well as to the broader polar ecosystem. These compounds are carried to the polar regions via atmospheric transport mechanisms, but it is less clear how they partition between air, snow/ice, water and soil. Previous studies have found quantifiable concentrations of OCs in each of these compartments, but the extent to which they interact is still largely unknown. Measurements of the concentration of several organochlorine pesticides and PCB congeners in the air, ice, snowpack, and water were made near Barrow, AK, from February-April 2009 as a project within the OASIS campaign, and again during the seasonal snowmelt in May-June 2009 in conjunction with SNOWNET. Our first dataset, when combined with atmospheric measurements and physical snowpack characterization made by other participants in OASIS, allows us to better understand the seasonal accumulation of OCs on snow and ice. Our second dataset, in which we track the movement of OCs through the snowpack and into meltwater runoff, is used in conjunction with snow deposition and hydrological data collected for the SNOWNET study to present a detailed picture of the release and ultimate fate of OCs incorporated into the snowpack during winter.

  4. Delayed plumage maturation in the orchard oriole ( Icterus spurius ): tests of winter adaptation hypotheses

    Microsoft Academic Search

    David A. Enstrom

    1992-01-01

    Summary Explanations of delayed plumage maturation (DPM) in passerines have focused on potential breeding season advantages for non-definitive (subadult) plumage. In contrast, the molt constraint hypothesis (Rohwer and Butcher 1988) proposes that subadult plumage is a winter adaptation, increasing winter survivorship by decreasing intraspecific aggression (the winter status signaling hypothesis) or predation (the winter crypsis hypothesis). Under the molt constraint

  5. Retrieval of the ultraviolet effective snow albedo during 1998 winter campaign in the French Alps.

    PubMed

    Smolskaia, Irina; Masserot, Dominique; Lenoble, Jacqueline; Brogniez, Colette; de la Casinière, Alain

    2003-03-20

    A measurement campaign was carried out in February 1998 at Briançon Station, French Alps (44.9 degrees N, 6.65 degrees E, 1,310 m above sea level) in order to determine the UV effective snow albedo that was retrieved for both erythemal and UV-A irradiances from measurements and modeling enhancement factors. The results are presented for 15 cloudless days with very variable snow cover and a small snowfall in the middle of the campaign. Erythemal irradiance enhancement due to the surface albedo was found to decrease from approximately +15% to +5% with a jump to +22% after the snowfall, whereas UV-A irradiance enhancement decreased from 7% to 5% and increased to 15% after the snowfall. Thesevalues fit to effective surface albedos of 0.4, 0.1, and 0.5 for erythemal, and to effective albedos of 0.25, 0.1, and 0.4 for UV-A irradiances, respectively. An unexpected difference between the effective albedos retrieved in the two wavelength regions can be explained by the difference of the environment contribution. PMID:12665089

  6. Modeling the winter-spring transition of first-year ice in the western Weddell Sea

    NASA Astrophysics Data System (ADS)

    Jeffery, N.; Hunke, E. C.

    2014-09-01

    A new halodynamic scheme is coupled with the Los Alamos sea ice model to simulate western Weddell Sea ice during the winter-spring transition. One-dimensional temperature and salinity profiles are consistent with the warming and melt stages exhibited in first-year ice cores from the 2004 Ice Station POLarstern (ISPOL) expedition. Results are highly sensitive to snowfall. Simulations which use reanalysis precipitation data do not retain a snow cover beyond mid-December, and the warming transition occurs too rapidly. Model performance is greatly improved by prescribing a snowfall rate based on reported snow thicknesses. During ice growth prior to ISPOL, simulations indicate a period of thick snow and upper ice salinity enrichment. Gravity drainage model parameters impact the simulation immediately, while effects from the flushing parameter (snow porosity at the ice top) appear as the freeboard becomes negative. Simulations using a snow porosity of 0.3, consistent with that of wet snow, agree with salinity observations. The model does not include lateral sources of sea-water flooding, but vertical transport processes account for the high upper-ice salinities observed in ice cores at the start of the expedition. As the ice warms, a fresh upper-ice layer forms, and the high salinity layer migrates downward. This pattern is consistent with the early spring development stages of high-porosity layers observed in Antarctic sea ice that are associated with rich biological production. Future extensions of the model may be valuable in Antarctic ice-biogeochemical applications.

  7. Desiccation-tolerance of Fagus crenata blume seeds from localities of different snowfall regime in central Japan

    Microsoft Academic Search

    Emiko Maruta; Tomohiko Kamitani; Midori Okabe; Yuji Ide

    1997-01-01

    In beech (Fagus crenata Blume) forests on the Pacific Ocean side in Central Japan, snowpack depth is little and xeric conditions may prevail in winter,\\u000a in contrast to heavy snow in beech forests on the Japan Sea side. The effects of such conditions during winter on the viability\\u000a of beech seeds were studied at a beech forest on the Pacific

  8. Features of air masses associated with the deposition of Pseudomonas syringae and Botrytis cinerea by rain and snowfall.

    PubMed

    Monteil, Caroline L; Bardin, Marc; Morris, Cindy E

    2014-11-01

    Clarifying the role of precipitation in microbial dissemination is essential for elucidating the processes involved in disease emergence and spread. The ecology of Pseudomonas syringae and its presence throughout the water cycle makes it an excellent model to address this issue. In this study, 90 samples of freshly fallen rain and snow collected from 2005-2011 in France were analyzed for microbiological composition. The conditions favorable for dissemination of P. syringae by this precipitation were investigated by (i) estimating the physical properties and backward trajectories of the air masses associated with each precipitation event and by (ii) characterizing precipitation chemistry, and genetic and phenotypic structures of populations. A parallel study with the fungus Botrytis cinerea was also performed for comparison. Results showed that (i) the relationship of P. syringae to precipitation as a dissemination vector is not the same for snowfall and rainfall, whereas it is the same for B. cinerea and (ii) the occurrence of P. syringae in precipitation can be linked to electrical conductivity and pH of water, the trajectory of the air mass associated with the precipitation and certain physical conditions of the air mass (i.e. temperature, solar radiation exposure, distance traveled), whereas these predictions are different for B. cinerea. These results are pertinent to understanding microbial survival, emission sources and atmospheric processes and how they influence microbial dissemination. PMID:24722630

  9. Carbon limitation of soil respiration under winter snowpacks: potential feedbacks between growing season and winter carbon fluxes

    Microsoft Academic Search

    PAUL D. B ROOKS; K ELL

    2004-01-01

    A reduction in the length of the snow-covered season in response to a warming of high- latitude and high-elevation ecosystems may increase soil carbon availability both through increased litter fall following longer growing seasons and by allowing early winter soil frosts that lyse plant and microbial cells. To evaluate how an increase in labile carbon during winter may affect ecosystem

  10. Winter 2007 Practicing Medicine

    E-print Network

    Cui, Yan

    Winter 2007 Practicing Medicine in the Line of Fire #12; UTHealthScienceCenter University of tennessee HealtH science center Medicine Magazine Winter 2007 CommunicationsTeam Writing,Editing Sh ................................................................................................ DirectorofDevelopment VaCanT DirectorofplannedgivingVaCanT University of Tennessee Medicine Magazine

  11. Winter Math Activities

    NSDL National Science Digital Library

    Terry Kawas

    2013-01-01

    This webpage of winter math activities includes seasonal activities for patterns, graphing, symmetry, estimations, and glyphs. Other resources on this page include literature connections, links to more winter resources, and pictures of student work. Activities are centered on penguins, snowflakes, snowman, and gingerbread.

  12. Bison in Winter

    USGS Multimedia Gallery

    A plains bison in winter at Yellowstone National Park. A bison's hump is useful as a snowplow in winter when the animal swings its head from side to side to brush aside the snow to reach food underneath. The hump is composed of muscles supported by long vertebrae....

  13. Winter 2014 Economics 471

    E-print Network

    Carter, John

    Winter 2014 Economics 471: Public Finance Government Finance -- Syllabus Winter 2014 1 US Treasury intervention in the market. After covering basic prin- ciples of public finance, we will focus on the taxing Textbook: Public Finance and Public Policy (4th Edition) by Jonathan Gruber. Available at the bookstore

  14. Winter Refuge for Aedes aegypti and Ae. albopictus Mosquitoes in Hanoi during Winter

    PubMed Central

    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 <10°C. During July 2010 to March 2012, we surveyed monthly for Aedes larvae and pupae in 120 houses in 8 Hanoi districts. Aedes albopictus preferred discarded containers in summer and pupal 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. PMID:24752230

  15. Winter atmospheric circulation and river discharge in northwest Europe

    Microsoft Academic Search

    Laurens M. Bouwer; Jan E. Vermaat; Jeroen C. J. H. Aerts

    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 Großwetterlagen classification system and the North Atlantic Oscillation (NAO) index, on variation in basin-average precipitation and winter discharges

  16. Mesospheric structure and the D-region winter anomaly

    Microsoft Academic Search

    D. Offermann; H. G. Brueckelmann; K. M. Torkar; H. Widdel

    1981-01-01

    In connection with the 'winter anomaly', pronounced increases in radio wave absorption can occur during the winter within the ionospheric D-region. It is widely accepted today that the enhanced radio wave absorption is related to increases in electron density within the D-region. An investigation is conducted concerning the reasons for the rise and fall in electron density. On the basis

  17. American woodcock winter distribution and fidelity to wintering areas

    USGS Publications Warehouse

    Diefenbach, D.R.; Derleth, E.L.; Vander Haegen, W.M.; Nichols, J.D.; Hines, J.E.

    1990-01-01

    We examined winter distribution and fidelity to wintering areas for the American Woodcock (Scolopax minor), which exhibits reversed, sexual size dimorphism. Band-recovery data revealed no difference in winter distributions of different age/sex classes for woodcock from the same breeding areas. Similarly, band recoveries from woodcock banded on wintering grounds revealed no difference in fidelity to wintering sites. Males may winter north of a latitude that is optimal for survival based on physiological considerations, but they gain a reproductive advantage if they are among the first to arrive on the breeding grounds. This may explain our results, which indicate males and females have similar distribution patterns during winter.

  18. The History of Winter: A Professional Development "Teacher as Scientist" Experiential Learning Field Experience.

    NASA Astrophysics Data System (ADS)

    Gabrys, R. E.

    2007-12-01

    Each year since 2000, the NASA Goddard History of Winter (HOW) program has allowed teachers to develop an understanding of the consequences of one segment of the orbit of the tilted Earth in its path around the sun. Scientists from NASA, CRREL, and Michigan Tech, supported by the Whiteface Observatory, and the science program at Northwood School in Lake Placid, New York, use the weather and the stratigraphy in the ice and snow, consequences of the weather changes, as "teachers" in a team study of the winter record. Snow in the air and on the ground, ice, its crystal structure and axial orientation, and the ecosystem consequences of snow and ice constitute the weeklong content package. Teacher Professional Development Standards A, B, C, and D were the guiding principles in developing HOW with a content structure formulated as protocols to serve as inserts into lesson plans and inquiry guides. The concept of HOW within NASA is to provide understanding of the WHY? and WHAT? of satellite remote sensing. The content is appropriate ground validation in that techniques presented in protocols are identical to those used by professionals who study snow pits, evaluate features in snow metamorphism, and study thin sections of ice cores drilled in ice caps and glaciers. The HOW Teacher as scientist (TAS) model is a flexible model. HOW enables teachers who are required to use inquiry-based facilitation in the classroom to experience inquiry themselves. Teachers with little science content background as well as those with Science degrees have participated in HOW working alongside of the science team. Accommodations are made through differentiation of instruction so that each group leaves with a mastery of the content that is appropriate for the transition to presentation in the classroom. Each year builds on the previous year ensuring a time series record of the history of winter-by itself a learning experience. An offshoot of the NASA Goddard Center History of Winter (HOW) Program, the Global Snowflake Network (GSN) launched in the winter of 2006 engages an international audience including both formal and informal education groups. The goal is to provide an interactive online data resource in science and education for the characterization of snowfall and related weather systems. The Global Snowflake Network has been accepted as an education outreach proposal for the International Polar Year. Collaborations with other agencies and universities also with IPY-accepted proposals are now underway. HOW and the GSN are endorsed by the NASA Goddard Education Office and many of the Goddard Snow and Ice Team scientists. Together these programs offer a unique, sustainable, and proven outreach for the Cryosphere research program. Snowflakes are like frozen data points, their shape is a record of atmospheric conditions at the time of their formation. The shapes of snowflakes vary over the winter season, with the source of a weather system and over the course of a given snowfall. The objective of the Global Snowflake Network (GSN) is to create a global ground team of teachers, students, families, and researchers worldwide to identify snowflake types during the progress of snowfalls. The result is a unique and scientifically valid resource useful to meteorology and scientific modeling of Earth's Hydrosphere. The Global Snowflake Network (GSN), simultaneously a science program and an education program is presented as a simple, scientifically valid project that has the potential to spread the IPY message and produce a lasting resource to further scientific understanding of Earth's hydrology through the study of snow.

  19. Impacts of a changing winter precipitation regime on the Great Snowforest of British Columbia, Canada

    NASA Astrophysics Data System (ADS)

    Knudsvig, H.; Dery, S. J.; Coxson, D.

    2012-12-01

    Rising air temperatures have profoundly impacted British Columbia (BC) mountain ecosystems, including its Interior Wetbelt. This region supports the sole Interior Temperate Rainforest (ITR), or perhaps more appropriately "snowforest", of North America. This snowforest encompasses about 30,500 km2 and contains Western redcedar (Thuja plicata) and western hemlock (Tsuga heteropylla) in excess of 1500 years old. This region is projected to be one of the more vulnerable biogeoclimatic zones in BC due to forest operations and climate change. Loss of snow as a storage medium has the potential to negatively affect the forest. A decrease in snow water equivalent (SWE) has the potential to decrease soil moisture values; impacts of decreased water availability in this region have the possibility to affect soil moisture storage, vegetative species composition, flora and fauna interdependence, and pathogen outbreaks. Given the projected climate change in high latitude and altitude areas, this project analyzes the contemporary and potential future climate of BC's Interior Wetbelt and explores the possible environmental and ecohydrological impacts of climate change on the snowforest. Models project an increase in air temperature and precipitation but a decrease in snowfall in this region. Analyses of the snow depth, SWE, and temperature from the Upper Fraser River Basin automated snow pillow sites of the BC River Forecast Centre (RFC) were conducted; snow depth, SWE, and temperature were also measured at the field site via automated weather stations and bi-monthly snow surveys. Surveys recorded depth and SWE after observed peak accumulation and continued until snowpack was depleted in 80% of the field site. To determine the influence of precipitation on the soil moisture levels in the ITR, soil moisture and water table levels were measured for the 2011-12 water year in addition to meteorological conditions; snow, spring water, and near surface ground water samples were collected and analyzed for the environmental isotopes of deuterium and oxygen-18. Analysis of the RFC's snow pillow data shows April 1 snow depth has been highly variable in the last 25 years with an overall decline in depth and SWE values. Soil moisture values at the study site were consistent through the year but showed a peak during spring melt and a decline during August, the driest month of summer in this region. Isotopic analysis on the water samples is on-going. The Upper Fraser River Basin experienced an above-normal to record snowpack the winter of 2011-12, thus observed values may not be indicative of the overall trend for this area. Trends in this interconnected ecosystem can assist in determining impacts of climate change to northern climates.

  20. Winter Weather: Indoor Safety

    MedlinePLUS

    ... Health Matters What's New Preparation & Planning Disasters & Severe Weather Earthquakes Extreme Heat Floods Hurricanes Landslides Tornadoes Tsunamis ... Outdoor Safety Winter PSAs and Podcasts Disasters & Severe Weather Earthquakes Extreme Heat Floods Hurricanes Landslides Tornadoes Tsunamis ...

  1. Winter Weather Checklists

    MedlinePLUS

    ... Health Matters What's New Preparation & Planning Disasters & Severe Weather Earthquakes Extreme Heat Floods Hurricanes Landslides Tornadoes Tsunamis ... Weather Information on Specific Types of Emergencies Winter Weather Checklists Language: English Español (Spanish) Recommend on Facebook ...

  2. In Depth Winter Weather

    NSDL National Science Digital Library

    2012-01-01

    Winter Weather is an In-Depth Special Report form the National Center for Atmospheric Research. It contains articles, images, activities, video clips, and interactive graphs to inform learners about meteorology and weather in the colder seasons.

  3. Mesospheric structure and the D-region winter anomaly

    SciTech Connect

    Offermann, D. (Wuppertal, Gesamthochschule, Wuppertal, West Germany); Brueckelmann, H.G. (Graz Universitaet, Graz, Austria); Torkar, K.M. (Max-Planck-Institut fuer Aeronomie, Lindau ueber Northeim, West Germany)

    1981-01-01

    In connection with the 'winter anomaly', pronounced increases in radio wave absorption can occur during the winter within the ionospheric D-region. It is widely accepted today that the enhanced radio wave absorption is related to increases in electron density within the D-region. An investigation is conducted concerning the reasons for the rise and fall in electron density. On the basis of a data evaluation related to the Western European Winter Anomaly Campaign 75/76, it appears possible that turbulence is a buildup mechanism for winter anomaly. A model with only two atmospheric parameters is discussed. In this model, increased turbulence is responsible for the onset of winter anomaly, which is turned off by conditions of increasing horizontal wind speed.

  4. Warmest winter in history

    NSDL National Science Digital Library

    Payne, Laura X.

    For four days last week, the daily temperatures outside the Internet Scout Project office here in Wisconsin soared above 60 F (and on one day, above 75 F), and the lakes that surround Madison melted in one fell swoop, bringing winter to a lurching halt and restless thoughts of summer to the forefront. While such local temperature anomalies are not surprising (nor did other cities experience the same highs), in this case, they fit in with a global trend that continues to raise -- in some cases, anxious -- eyebrows. On Friday, the National Oceanic and Atmospheric Administration (NOAA) announced that this winter is the warmest on record. Surpassing recent warm winter records of 1997-1998, the winter of 1999-2000 has now clinched the somewhat dubious title of warmest winter in history. This news release comes on the coat tails of a January report from the National Academy of Sciences confirming what is already accepted among most scientists -- that global warming is real (see the January 14, 2000 Scout Report). For news and information on this warmest of winters, this week's In The News features seven sites, listed above.

  5. Atmospheric Composition under Impermeable Winter Golf Green Protections

    Microsoft Academic Search

    Philippe Rochette; Julie Dionne; Yves Castonguay; Yves Desjardins

    2006-01-01

    The utilization of impermeable winter covers on annual bluegrass (Poa annua var. reptans (Hauskn.) Timm.) golf greens as a protection against excess water and ice is increasing rapidly in Canada and elsewhere in northern climates. A study was conducted to examine the impact of these covers on the atmospheric composition over golf green turfgrass during the 1997-1998 and 1998-1999 winters

  6. Yield and yield components of winter-type safflower

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Safflower (Carthamus tinctorius L.) is a minor yet widely grown oil seed crop adapted to semi-arid regions. The nascent development of winter adapted safflower, allowing fall planting,could substantially increase seed production over spring planting. In this study four winter type safflower accessi...

  7. Introduction Modern winter barley cultivars are capable of yields in

    E-print Network

    Liskiewicz, Maciej

    that are susceptible to lodging and disease with resulting decreased yields and increased input costs. The potential are one to two weeks earlier than for winter wheat, and thus fall N uptake can be greater for win- ter barley than for winter wheat. Excessive fall barley growth can occur and result in freeze injury to stems

  8. Winter CO2 and CH4 fluxes along a trans-Alaska pipeline during three winters

    NASA Astrophysics Data System (ADS)

    Kim, Y.; Enomoto, H.; Kimura, S.; Kadosaki, G.

    2007-12-01

    This research was carried out to estimate the winter fluxes of CO2 and CH4 using the static chamber and the concentration profile methods along a trans-Alaska pipeline during three winters of 2004/5, 2005/6, and 2006/7. The 3-year averaged winter fluxes of CO2 and CH4 in taiga and tundra were 0.60±0.03 (SE; standard error) and 0.39±0.04 gCO2-C/m2/d, and 2.62±0.31 and 2.60±0.27 mgCH4-C/m2/d, respectively. This suggests that CH4 was emitted through the snowpack to the atmosphere along a latitudinal transect during the winter. Winter CH4 emission may be occurred through vascular plants such as Sedges on the tussock. The annually averaged snow depth and SWE (snow water equivalent) as well as winter emissions of CO2 and CH4 were remarkably decreased in taiga temporally. On the other hand, although the snow depth and SWE were decreased in tundra, winter emissions of CO2 and CH4 were increased with yearly. The 3-year averaged wintertime emissions of CO2 and CH4 were 115±6.4 gCO2-C/m2/season and 0.59±0.06 gCH4- C/m2/season along a trans-Alaska pipeline during three winters. This implies that winter emissions of CO2 and CH4 are an important part of the annual carbon budget in seasonally snow-covered terrain of typical boreal forest and tundra soils.

  9. Snow line analysis in the Romanian Carpathians under the influence of winter warming

    NASA Astrophysics Data System (ADS)

    Micu, Dana; Cosmin Sandric, Ionut

    2013-04-01

    The Romanian Carpathians are subject to winter warming as statistically proved by station measurements over a 47 year period (1961-2007). Herein, the snow season is considered to last from the 1st of November to the 30th of April, when snowpack usually reaches the highest stability and thickness. This paper investigates the signals of winter temperature and precipitation change at 17 mountain station located above 1,000 m, as being considered the main triggering factors of large fluctuations in snow amount and duration in these mountains. Fewer snowfalls were recorded all over the Romanian Carpathians after the mid 80s and over large mountain areas (including the alpine ones) the frequency of positive temperature extremes became higher (e.g. winter heat waves). Late Fall snowfalls and snowpack onsets (mainly in mid elevation areas, located below 1,700 m) and particularly the shifts towards early Spring snowmelts (at all the sites) were statistically proved to explain the decline of snow cover duration across the Carpathians. However, the sensitivity of snow cover duration to recent winter warming is still blurred in the high elevation areas (above 2,000 m). The trends in winter climate variability observed in the Romanian Carpathians beyond 1,000 m altitude are fairly comparable to those estimated in other European mountain ranges from observational data (e.g. the Swiss Alps, the French Alps and the Tatra Mts.). In relation to the climate change signals derived from observational data provided by low density mountain meteorological network (of about 3.3 stations per km2 in the areas above 1,000 m), the paper analysis the spatial probability and evolution trends of snow line in each winter season across the Romanian Carpathians, based on Landsat satellite data (MSS, TM and ETM+), with sufficiently high spatial (30 to 60 m) and temporal resolutions (850 images), over the 1973-2011 period. The Landsat coverage was considered suitable enough to enable an objective statistical assessment of snow line and snow cover change across the Carpathians, providing results obtained for the first time in the national specialist literature on this topic. The satellite images were bulk processed for calibration to radiance and reflectance and the Normalized Difference Standardized Index (NDSI) and Land Surface Temperature (LST) have been extracted (the latter, only for TM and ETM+) and validated with ground meteorological measurements. All NDSIs and LSTs were merged into distinct monthly images covering the entire mountain range for each 38 winters in the study period. A quantitative analysis of snow line elevation change in relation to the variability of freezing level has been conducted. The snow line change across the Romanian Carpathians derived from satellite imagery has been used as a proxy for local response of the Carpathian climate to the warming process also observed in other mountain regions of Europe. The winter warming observed in the last decades caused an upward shift of the snow line and freezing level, associated to a shrinking of snow cover area all over the Carpathians, particularly after 2000. The paper's findings explain partially the difficulties that winter tourism industry in Romania has been facing in the last years due to the lack of snow or poor snow coverage, particularly in the low elevation ski domains located below the snow reliability line

  10. Winter Storm Lesson Plan

    NSDL National Science Digital Library

    Tasia S.

    2010-09-23

    The subject of this lesson is Winter Storms. The length will be approximately 55 minutes (~15 minutes for each of the three websites and ~10 minutes for the students to create their slideshows). The slideshows may be presented the following day if not enough time is available. This lesson is intended for 4th grade and is directed towards Standard 2 of the 4th grade science core curriculum. This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Winter Storms Connection to Standards: Utah Core Curriculum: Science Standard 2 (Students will understand that the elements of weather can be observed, measured, and recorded to make predictions and determine simple weather patterns.) NETS-T: 1. Facilitate and Inspire Student Learning and Creativity - Students will be using websites and situations that ...

  11. Winter Storm (weather)

    NSDL National Science Digital Library

    Aubree Miller

    2009-09-28

    This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. First think about these questions: 1. What is your favorite aspect of winter weather? 2. How does the weather effect your everyday life? Form groups of THREE. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper... 1. In general, when are winds formed? 2. When winds are blowing, how can you ...

  12. Parental overwintering history affects the responses of Thlaspi arvense to warming winters in the North

    Microsoft Academic Search

    Timo Saarinen; Robin Lundell; Helena Åström; Heikki Hänninen

    2011-01-01

    The overwintering conditions of northern plants are expected to change substantially due to global warming. For perennial plants, winter warming may increase the risk of frost damage if the plants start dehardening prematurely. On the other hand, evergreen plants may remain photosynthetically active and thereby benefit from milder winters. The positive and negative effects of mild winters on annual plants

  13. An observational study of the D-region winter anomaly and sudden stratospheric warmings

    Microsoft Academic Search

    K. Kawahira

    1982-01-01

    An observational study of the link between the winter anomaly in ionospheric absorption and sudden stratospheric warmings for the 1967\\/1968 winter has been made. On the basis of the daily large-scale distributions of the absorption index, it is found that the winter anomaly during sudden warming could result from a NO increase induced by southward transport from the polar region,

  14. ANNUAL WINTER SCHOOLANNUAL WINTER SCHOOL Petersburg Nuclear Physics Institute

    E-print Network

    Titov, Anatoly

    ANNUAL WINTER SCHOOLANNUAL WINTER SCHOOL Petersburg Nuclear Physics Institute National Research February ­ 1 March, 2014 Petersburg Nuclear Physics Institute (PNPI) conducts the XLVIII Annual Winter Physics · Theoretical Physics School · School on Nuclear Reactor Physics · Accelerator Physics School

  15. Measuring Transpiration to Regulate Winter Irrigation Rates

    SciTech Connect

    Samuelson, Lisa [Auburn University] [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. Variation In Winter Hardiness Among Safflower Accessions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fall planted safflower (Carthamus tinctorius L.) would provide management alternatives in crop rotations and potentially increase yield. Our objective was to relate several fall growth factors to winter survival in a diverse set of 11 safflower accessions grown at Central Ferry and Pullman WA, USA....

  17. Study Abroad Winter Service Program

    E-print Network

    Liskiewicz, Maciej

    Study Abroad Winter Service Program Belize Cayo District (San Ignacio) Winter Break January 1 January 8, 2015 BELIZE Belize borders Mexico, Guatemala language, alt- hough Spanish and Kriol are commonly spoken as well. Belize is separated

  18. Winter anomaly observations at the Panska Ves Observatory \\/Czechoslovakia\\/, 1971-1973

    Microsoft Academic Search

    J. Lastovicka; P. Triska

    1976-01-01

    The results of the winter anomaly observations at the Panska Ves Observatory at 2775 kHz and 2614 kHz are studied for the winters of 1971\\/72 and 1972\\/73. Ionospheric responses to minor (1972) and major stratospheric warmings are found to be different and relatively small. A regular winter-anomaly background absorption increase with a maximum in January was observed during both winters

  19. Winter Climate Limits Subantarctic Low Forest Growth and Establishment

    PubMed Central

    Harsch, Melanie A.; McGlone, Matt S.; Wilmshurst, Janet M.

    2014-01-01

    Campbell Island, an isolated island 600 km south of New Zealand mainland (52°S, 169°E) is oceanic (Conrad Index of Continentality ?=??5) with small differences between mean summer and winter temperatures. Previous work established the unexpected result that a mean annual climate warming of c. 0.6°C since the 1940's has not led to upward movement of the forest limit. Here we explore the relative importance of summer and winter climatic conditions on growth and age-class structure of the treeline forming species, Dracophyllum longifolium and Dracophyllum scoparium over the second half of the 20th century. The relationship between climate and growth and establishment were evaluated using standard dendroecological methods and local climate data from a meteorological station on the island. Growth and establishment were correlated against climate variables and further evaluated within hierarchical regression models to take into account the effect of plot level variables. Winter climatic conditions exerted a greater effect on growth and establishment than summer climatic conditions. Establishment is maximized under warm (mean winter temperatures >7 °C), dry winters (total winter precipitation <400 mm). Growth, on the other hand, is adversely affected by wide winter temperature ranges and increased rainfall. The contrasting effect of winter warmth on growth and establishment suggests that winter temperature affects growth and establishment through differing mechanisms. We propose that milder winters enhance survival of seedlings and, therefore, recruitment, but increases metabolic stress on established plants, resulting in lower growth rates. Future winter warming may therefore have complex effects on plant growth and establishment globally. PMID:24691026

  20. Winter climate limits subantarctic low forest growth and establishment.

    PubMed

    Harsch, Melanie A; McGlone, Matt S; Wilmshurst, Janet M

    2014-01-01

    Campbell Island, an isolated island 600 km south of New Zealand mainland (52 °S, 169 °E) is oceanic (Conrad Index of Continentality ?=? -5) with small differences between mean summer and winter temperatures. Previous work established the unexpected result that a mean annual climate warming of c. 0.6 °C since the 1940's has not led to upward movement of the forest limit. Here we explore the relative importance of summer and winter climatic conditions on growth and age-class structure of the treeline forming species, Dracophyllum longifolium and Dracophyllum scoparium over the second half of the 20th century. The relationship between climate and growth and establishment were evaluated using standard dendroecological methods and local climate data from a meteorological station on the island. Growth and establishment were correlated against climate variables and further evaluated within hierarchical regression models to take into account the effect of plot level variables. Winter climatic conditions exerted a greater effect on growth and establishment than summer climatic conditions. Establishment is maximized under warm (mean winter temperatures >7 °C), dry winters (total winter precipitation <400 mm). Growth, on the other hand, is adversely affected by wide winter temperature ranges and increased rainfall. The contrasting effect of winter warmth on growth and establishment suggests that winter temperature affects growth and establishment through differing mechanisms. We propose that milder winters enhance survival of seedlings and, therefore, recruitment, but increases metabolic stress on established plants, resulting in lower growth rates. Future winter warming may therefore have complex effects on plant growth and establishment globally. PMID:24691026

  1. Late Holocene Winter Temperatures in the Eastern Mediterranean and Their Relation to Cultural Changes: The Kocain Cave Record

    NASA Astrophysics Data System (ADS)

    Mert Gokturk, Ozan; Fleitmann, Dominik; Badertscher, Seraina; Cheng, Hai; Edwards, R. Lawrence; Tuysuz, Okan

    2015-04-01

    Based on the ?13C profile of a stalagmite from the Kocain Cave in southern Turkey, we present a new proxy record of winter temperatures for the Eastern Mediterranean covering the last ~5500 years. In this region precisely-dated and highly-resolved paleoclimate records for the cold season are almost non-existent. The comparison of the most recent part of the Kocain record with meteorological observations reveals that stalagmite ?13C values correlate on decadal scale with the amount of snowfall above the cave, which correlates well with average winter temperatures. More negative ?13C values indicate higher drip rates in the cave due to more efficient infiltration during snowmelt above Kocain Cave, during colder winters. Cold periods in the rest of the record coincide with widespread glacier advances, especially with the ones in the Alps during the Bronze Age - Iron Age transition (from ~1000 BC on) and the late Little Ice Age (~1600 to 1850 AD). This further supports the interpretation of ?13C as a temperature proxy. Although winters during the Medieval Climate Anomaly were not continuously warm in the Eastern Mediterranean, winter warmth in the modern era was matched or exceeded several times in the last ~5700 years, especially during the time of Minoan civilization in Crete (~2700 to 1200 BC). Moreover, we provide evidence for the important role of winter cold and drought in the events leading to the unrest in the 16th century Anatolia during the Ottoman rule. Kocain Cave record brings insights into several climatically-induced historical changes in the Eastern Mediterranean, and has the potential to be a key record in a region with a long and vibrant history.

  2. Winter Wilderness Travel and Camping.

    ERIC Educational Resources Information Center

    Gilchrest, Norman

    Knowledge and skill are needed for safe and enjoyable travel and camping in the wilderness in winter. The beauty of snow and ice, reduced human use, and higher tolerance of animals toward humans make the wilderness attractive during winter. The uniqueness of winter travel presents several challenges that are not present in other seasons. Safety is…

  3. Lightning Protection against Winter Lightning

    Microsoft Academic Search

    Hitoshi Sugimoto

    2007-01-01

    Winter lightning, which occurs along the Sea of Japan coast, often damages transmission lines and distribution lines with the conventional lightning protection. These lines in mountainous areas suffer extensive damage from winter lightning. It is very important to investigate the features of lightning outages in detail to improve the lightning protection measures against winter lightning, therefore observations of lightning strokes

  4. Winter Playscape Dreaming

    ERIC Educational Resources Information Center

    Keeler, Rusty

    2006-01-01

    Winter, like all seasons, adds a new sense of mystery and discovery to the world of young children. It is the time when they can study snowflakes, find icicles, or observe the birds that share their yards. This article presents ideas and suggestions on how to plan a playscape. A playscape is a man-made seasonal playground for young children. It…

  5. winter 2015 Health Informatics

    E-print Network

    California at Davis, University of

    fall 2014/ winter 2015 Health Informatics Health Information Exchange Healthcare Analytics COntinUinG anD PrOfeSSiOnal eDUCatiOn HEALTH INFORMATICS ANd ANALYTICS #12;2 Advancing Health Care Through healthcare delivery and clinical effectiveness. UC Davis Extension, a leader in health informatics education

  6. Physical Oceanography Winter 2013

    E-print Network

    Thompson, Andrew

    Physical Oceanography Winter 2013 Andrew Thompson January 8, 2013 Lecture 1. Introduction This course presents an introduction to physical oceanography with a particular focus on ocean circulation. It is assumed that students taking this course have had limited prior exposure to oceanography or fluid dynamics

  7. GRAND RIVER Winter 2014

    E-print Network

    Thompson, Michael

    GRAND RIVER POST SECONDARY BOARD NEWSLETTER Winter 2014 Issue 55 P.O. Box 339 Ohsweken ON, N0A 1M0-mail: info@grpseo.org Website: www.grpseo.org Grand River Post Secondary Board Members Brenda Davis (Chair TO TOMORROW Onkwehon:we with Grand River Territory lineage are empowered through higher education within

  8. Humanities 1 Winter 2013

    E-print Network

    Blanco, Philip R.

    of these tests tend to show that human beings are not made in the image of God; they aren't smart enoughHumanities 1 Winter 2013 Professor Cox Writing Assignment No. 2 (first graded assignment) Select as you can. 2. "In Genesis and Exodus 1-23, men and women are frequently subjected to tests. The outcomes

  9. WINTER 2014 Sustainability and

    E-print Network

    Stephens, Graeme L.

    WINTER 2014 Sustainability and Renewable Energy in Costa Rica January 4 - 14 Dr. James Hoffmann, Program Director Lecturer Sustainability Studies Program E-511 Melville Library Stony Brook, NY 11794 sustainability and renewable energy. Students will spend 11 days in Costa Rica to participate in site visits

  10. Announcement Cryptography { Winter 2001

    E-print Network

    deYoung, Brad

    Announcement Cryptography { Winter 2001 A course in Cryptography is scheduled to be o#11;ered) and a computing course (AM 2120 or CS 2710 or CS 2602). Suggested Text: \\Cryptography { Theory and Practice, but doing so #12;rst requires a discussion of the discrete logarithm problem). 5. Public-Key Cryptography

  11. WINTER UNIVERSIADE CONFERENCE 2013

    E-print Network

    Di Pillo, Gianni

    WINTER UNIVERSIADE CONFERENCE 2013 December 9-10 International Interdisciplinary Conference on) Rovereto (Trento), Italy 1st Announcement www.universiadetrentino.org #12;MAIN CONFERENCE THEME The main goal of the Trentino 2013 Conference is to work on the relationship between sport and innovation

  12. Fall/ Winter 2003 In this issue

    E-print Network

    Hamilton, Kevin

    pastor in Quebec City re- corded in his diary entry for June 8th: "Bleak, cold, very uncommon weather." There are contem- porary references to snow drifts up to the axles of carriages in Quebec City. The snowstorm for significant snowfall in post-1951 modern weather records at Quebec City is May 6. The late snowstorm occurred

  13. Increased snow facilitates plant invasion in mixedgrass prairie.

    PubMed

    Blumenthlal, D; Chimner, R A; Welker, J M; Morgan, J A

    2008-07-01

    Although global change is known to influence plant invasion, little is known about interactions between altered precipitation and invasion. In the North American mixedgrass prairie, invasive species are often abundant in wet and nitrogen (N)-rich areas, suggesting that predicted changes in precipitation and N deposition could exacerbate invasion. Here, this possibility was tested by seeding six invasive species into experimental plots of mixedgrass prairie treated with a factorial combination of increased snow, summer irrigation, and N addition. Without added snow, seeded invasive species were rarely observed. Snow addition increased average above-ground biomass of Centaurea diffusa from 0.026 to 66 g m(-2), of Gypsophila paniculata from 0.1 to 7.3 g m(-2), and of Linaria dalmatica from 5 to 101 g m(-2). Given added snow, summer irrigation increased the density of G. paniculata, and N addition increased the density and biomass of L. dalmatica. Plant density responses mirrored those of plant biomass, indicating that increases in biomass resulted, in part, from increases in recruitment. In contrast to seeded invasive species, resident species did not respond to snow addition. These results suggest that increases in snowfall or variability of snowfall may exacerbate forb invasion in the mixedgrass prairie. PMID:19086291

  14. Titan's Winter Polar Vortex

    NASA Technical Reports Server (NTRS)

    Flasar, F.M.; Achterberg, R.K.; Schinder, P.J.

    2008-01-01

    Titan's atmosphere has provided an interesting study in contrasts and similarities with Earth's. While both have N$_2$ as the dominant constituent and comparable surface pressures $\\sim1$ bar, Titan's next most abundant molecule is CH$_4$, not O$_2$, and the dissociative breakup of CH$_4$ and N$_2$ by sunlight and electron impact leads to a suite of hydrocarbons and nitriles, and ultimately the photochemical smog that enshrouds the moon. In addition, with a 15.95-day period, Titan is a slow rotator compared to Earth. While the mean zonal terrestrial winds are geostrophic, Titan's are mostly cyclostrophic, whipping around the moon in as little as 1 day. Despite the different dynamical regime, Titan's winter stratosphere exhibits several characteristics that should be familiar to terrestrial meteorologists. The cold winter pole near the 1 -mbar level is circumscribed by strong winds (up to 190 m/s) that act as a barrier to mixing with airmasses at lower latitudes. There is evidence of enhancement of several organic species over the winter pole, indicating subsidence. The adiabatic heating associated with this subsidence gives rise to a warm anomaly at the 0.01-mbar level, raising the stratopause two scale heights above its location at equatorial latitudes. Condensate ices have been detected in Titan's lower stratosphere within the winter polar vortex from infrared spectra. Although not always unambiguously identified, their spatial distribution exhibits a sharp gradient, decreasing precipitously across the vortex away from the winter pole. The interesting question of whether there is important heterogeneous chemistry occurring within the polar vortex, analogous to that occurring in the terrestrial polar stratospheric clouds in the ozone holes, has not been addressed. The breakup of Titan's winter polar vortex has not yet been observed. On Earth, the polar vortex is nonlinearly disrupted by interaction with large-amplitude planetary waves. Large-scale waves have not been identified in Titan's atmosphere, so the decay of its polar vortex may be more gradual than on Earth. Observations from an extended Cassini mission into late northern spring should provide critical data indicating whether the vortex goes away with a bang or just fades away.

  15. Winter Storm Activity

    NSDL National Science Digital Library

    Mikel Barbieri

    2012-02-13

    This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What usually happens when there is a large difference between the temperatures? 4. What happens when there ...

  16. Winter weather activity

    NSDL National Science Digital Library

    Whitney Frankovic

    2009-09-28

    This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Weather Maker Simulator Use the weather simulation above to answer the following questions in complete sentences on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What usually happens when there is a large difference between the temperatures? 4. What happens when there is high ...

  17. Winter Storm Activity

    NSDL National Science Digital Library

    FerraraTechClassroom

    2012-02-06

    This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What usually happens when there is a large difference between the temperatures? 4. What happens when there ...

  18. Winter Storm Activity

    NSDL National Science Digital Library

    Kirsten Butcher

    2008-09-26

    This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What usually happens when there is a large difference between the temperatures? 4. What happens when there ...

  19. Storm Winter Activity

    NSDL National Science Digital Library

    KateOlsen58

    2009-09-28

    This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What usually happens when there is a large difference between the temperatures? 4. What happens when there ...

  20. Winter Storm Warning

    NSDL National Science Digital Library

    2009-09-28

    This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What usually happens when there is a large difference between the temperatures? 4. What happens when there ...

  1. Al's Winter Storm Activity

    NSDL National Science Digital Library

    Al

    2010-02-22

    This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What usually happens when there is a large difference between the temperatures? 4. What happens when there ...

  2. Winter Storm Activity

    NSDL National Science Digital Library

    Xuan

    2010-02-22

    This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? What is a better indicator of moisture in the air? 4. What happens when there is low ...

  3. Identification of Solid-Stem Winter Wheat Lines with Enhanced Winter Hardiness Phil Bruckner, Winter Wheat Breeder

    E-print Network

    Maxwell, Bruce D.

    Identification of Solid-Stem Winter Wheat Lines with Enhanced Winter Hardiness Phil Bruckner, Winter Wheat Breeder Project Description Montana winter wheat producers planted 2.45 million acres in 2009, 60% of which was grown in the North Central District. The leading winter wheat cultivar over

  4. winter storm activity

    NSDL National Science Digital Library

    Miss Prested

    2010-05-26

    This project explores factors that help create severe winter weather. It provides an interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What usually happens when there is a large difference between the temperatures? 4. What happens when there ...

  5. Chaffinch and Winter Wren

    NSDL National Science Digital Library

    2009-01-01

    Every morning when he walks the dog, retired professor of natural history Peter Slater can identify as many as thirty birds by their song alone. On a walk in a Scottish town with Ari Daniel Shapiro, Slater explains what two common songsters, the chaffinch and winter wren, are singing about, and how even city dwellers can learn to “bird by ear” in their own neighborhoods, with rewarding results. Also included is a Learn More section that provides background information on the scientists recorded in the podcast, lessons, images, and cool facts.

  6. Winter Survival: A Consumer's Guide to Winter Preparedness.

    ERIC Educational Resources Information Center

    Department of Energy, Washington, DC.

    This booklet discusses a variety of topics to help consumers prepare for winter. Tips for the home include: winterizing the home, dealing with a loss of heat or power failure, and what you need to have on hand. Another section gives driving tips and what to do in a storm. Health factors include suggestions for keeping warm, signs and treatment for…

  7. The winter anomaly and sudden stratospheric warmings

    Microsoft Academic Search

    J. Lastovicka

    1984-01-01

    Large-scale stratospheric warmings are examined on the basis of 22-year measurements of radio-wave absorption at the Panska Ves observatory. It is shown that these warmings, accompanied by the reversal of wind direction in the lower thermosphere, lead not to an increase but to a decrease in the radio-wave absorption in the lower ionosphere, i.e., to the disappearance of the winter

  8. Night eating syndrome and winter seasonal affective disorder

    Microsoft Academic Search

    Serge Friedman; Christian Even; Jacques Thuile; Frédéric Rouillon; Julien-Daniel Guelfi

    2006-01-01

    Night eating syndrome (NES) and winter seasonal affective disorder (SAD) share some features such as snacking for high-carbohydrate\\/high-fat food with increased weight, emotional distress, circadian disturbances, good response to serotoninergic antidepressants (SSRIs) and bright-light therapy. This study assessed the prevalence and socio-demographical and clinical correlates of the NES in a sample of 62 consecutive depressed outpatients with winter seasonal features

  9. Spirit's Winter Work Site

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Annotated Version

    This portion of an image acquired by the Mars Reconnaissance Orbiter's High Resolution Imaging Science Experiment camera shows the Spirit rover's winter campaign site. Spirit was parked on a slope tilted 11 degrees to the north to maximize sunlight during the southern winter season. 'Tyrone' is an area where the rover's wheels disturbed light-toned soils. Remote sensing and in-situ analyses found the light-toned soil at Tyrone to be sulfate rich and hydrated. The original picture is catalogued as PSP_001513_1655_red and was taken on Sept. 29, 2006.

    NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The High Resolution Imaging Science Experiment is operated by the University of Arizona, Tucson, and the instrument was built by Ball Aerospace and Technology Corp., Boulder, Colo.

  10. Summary We used the water relations model, WINWAT, to model winter water relations of three conifer species--eastern

    E-print Network

    Boyce, Richard L.

    to low rel- ative humidity, which increased transpiration rates, and low temperatures, which inhibited transpiration in the winter, e.g., low relative humidities, were more important to winter water relations in Colorado. Our results indicate that summer and winter tem- peratures and relative humidities (or

  11. WINTER 2013 Ohio State launches

    E-print Network

    WINTER 2013 Ohio State launches largest campaign in its history with celebration PAGE 6 impact 50 PAGE 22 #12;#12;winter 2013 ohio state impact 1 But for Ohio State Campaign Highlights of the big Kevin Fitzsimons Printer The Watkins Printing Company President, The Ohio State University Foundation

  12. Instructor: N. Jones Winter 2012

    E-print Network

    Instructor: N. Jones HCDE 401 Winter 2012 HCDE 401: Style and Editing in Scientific and Technical purposes and audiences. Contact Information: Office: Sieg 429F Instructor: Natasha N. Jones HCDE Department #12;Instructor: N. Jones HCDE 401 Winter 2012 Editing Objectives Develop an understanding of editing

  13. A comparison of winter mercury accumulation at forested and no-canopy sites measured with different snow sampling techniques

    USGS Publications Warehouse

    Nelson, S.J.; Johnson, K.B.; Weathers, K.C.; Loftin, C.S.; Fernandez, I.J.; Kahl, J.S.; Krabbenhoft, D.P.

    2008-01-01

    Atmospheric mercury (Hg) is delivered to ecosystems via rain, snow, cloud/fog, and dry deposition. The importance of snow, especially snow that has passed through the forest canopy (throughfall), in delivering Hg to terrestrial ecosystems has received little attention in the literature. The snowpack is a dynamic system that links atmospheric deposition and ecosystem cycling through deposition and emission of deposited Hg. To examine the magnitude of Hg delivery via snowfall, and to illuminate processes affecting Hg flux to catchments during winter (cold season), Hg in snow in no-canopy areas and under forest canopies measured with four collection methods were compared: (1) Hg in wet precipitation as measured by the Mercury Deposition Network (MDN) for the site in Acadia National Park, Maine, USA, (2) event throughfall (collected after snowfall cessation for accumulations of >8 cm), (3) season-long throughfall collected using the same apparatus for event sampling but deployed for the entire cold season, and (4) snowpack sampling. Estimates (mean ?? SE) of Hg deposition using these methods during the 91-day cold season in 2004-2005 at conifer sites showed that season-long throughfall Hg flux (1.80 ??g/m2) < snowpack Hg (2.38 ?? 0.68 ??g/m2) < event throughfall flux (5.63 ?? 0.38 ??g/m2). Mercury deposition at the MDN site (0.91 ??g/m2) was similar to that measured at other no-canopy sites in the area using the other methods, but was 3.4 times less than was measured under conifer canopies using the event sampling regime. This indicates that snow accumulated under the forest canopy received Hg from the overstory or exhibited less re-emission of Hg deposited in snow relative to open areas. The soil surface of field-scale plots were sprayed with a natural rain water sample that contained an Hg tracer (202Hg) just prior to the first snowfall to explore whether some snowpack Hg might be explained from soil emissions. The appearance of the 202Hg tracer in the snowpack (0-64% of the total Hg mass in the snowpack) suggests that movement of Hg from the soil into the snowpack is possible. However, as with any tracer study the 202Hg tracer may not precisely represent the reactivity and mobility of natural Hg in soils. ?? 2007 Elsevier Ltd. All rights reserved.

  14. Characterization of an unexpected snowfall event in Iqaluit, Nunavut, and surrounding area during the Storm Studies in the Arctic field project

    NASA Astrophysics Data System (ADS)

    Fargey, S.; Henson, W.; Hanesiak, J.; Goodson, R.

    2014-05-01

    Small accumulation precipitation events are critical for the high-latitude hydrological cycle. They contribute to more than 50% of total accumulation in the area and occur at a greater frequency than high-accumulation events. Despite their importance, the processes controlling them have not been investigated in sufficient detail. This study characterizes an unexpected high-latitude snowfall event at Iqaluit, Nunavut, and surrounding area during the Storm Studies in the Arctic field project. High-resolution data collected, from both ground based and airborne Doppler radar, along with upper air and surface observations, provided the basis for analysis of the conditions that led to the event and offer some insight as to why it was not well forecast by the Canadian operational model. Several factors worked in concert to produce this event. Low-level convection and upslope processes were important in cloud and precipitation generation over the orography upstream. When combined with additional lift from the passing of a weak trough, cloud and precipitation production were enhanced, allowing these features to penetrate over the terrain and resulted in precipitation at Iqaluit. Analysis of the global environmental multiscale limited area model (2.5 km resolution) suggests that upstream convection and upslope processes were affected by model errors. As a consequence, precipitation onset was delayed, and the total accumulation was 50% lower than the observations. Results indicate that the complexity of precipitation events in the region represents a significant challenge for predicting and modeling and understanding their role in the region's hydrological cycle.

  15. Multi-Frequency Radar and Microwave Radiometer Simulations of Surface Snowfall Events from GCPEx: Synergistic Application of In-Situ Microphysics Observations with Modeled Ice Scattering Properties

    NASA Astrophysics Data System (ADS)

    Kulie, M.; Nesbitt, S. W.; Harnos, D. S.; Heymsfield, A.; Johnson, B. T.; Tanelli, S.

    2014-12-01

    Preliminary results from a combined radar-microwave radiometer study using in-situ microphysics data and other observations from the Global Precipitation Measurement (GPM) Cold season Precipitation Experiment (GCPEx) will be presented in this study. The primary purpose of this work is to assess microwave ice particle scattering models by comparing forward model calculations with dual-frequency airborne radar and multi-frequency passive microwave observations of select surface snowfall events from GCPEx. Forward model radar and radiometer calculations require snowflake scattering properties to be integrated over particle size distributions, and both of these inherent microphysical quantities strongly influence unconstrained radar-radiometer simulations under snowing conditions. Therefore, direct airborne and ground-based ice particle size distribution measurements and other relevant microphysical properties will be used to build a physically realistic microphysical rendition of the atmospheric column to simulate both layer radar reflectivity signatures and top-of-the-atmosphere microwave radiometer brightness temperatures for select GCPEx cases. Comparisons of measured particle size distributions will also be made to particle size distribution parameter retrievals from airborne-only observations, and the subsequent sensitivity in simulated brightness temperatures will be discussed. Other simulation complicating factors (e.g., surface emissivity effects, cloud liquid water location and amount, etc.) and implications for GPM radar and radiometer retrievals will also be highlighted.

  16. Winter fuels report

    SciTech Connect

    Not Available

    1995-02-03

    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 and 30-Day outlook for temperature and precipitation and US total heating degree-days by city.

  17. Winter fuels report

    SciTech Connect

    Not Available

    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.

  18. Winter temperature variations over middle and lower reaches of the Yangtze River during the past three centuries

    NASA Astrophysics Data System (ADS)

    Hao, Z.-X.; Zheng, J.-Y.; Ge, Q.-S.; Wang, W.-C.

    2012-01-01

    We present statistically reconstructed annual winter (December-February) mean temperature in the Middle and Lower Reaches of the Yangtze River (24-34° N, east of 108° E) back to 1736. The reconstructions are based on information from snowfall days from Yu-Xue-Fen-Cun archive (one of historical documents proxies) in Qing Dynasty (1644-1911). Those information are calibrated with regional winter temperature series spanning the period 1951 to 2007 period. The gap from 1912 to 1950 is filled using early instrumental observation. With respect to the 1951-2007 climatology, the 18th century was 0.6 °C colder, and the 19th century was 1.0 °C colder. But since the 20th century, climate entered into the warming phase, particular in the last 30 yr, the mean temperature from 1981 to 2007 is 0.25 °C higher than that of climatology, a highest level of the past 300 yr. The uncertainty is existed for the period prior of 1900, and possible causes have been discussed here.

  19. Impact of Barents Sea winter air-sea exchanges on Fram Strait dense water transport

    NASA Astrophysics Data System (ADS)

    Moat, Bengamin I.; Josey, Simon A.; Sinha, Bablu

    2014-02-01

    Impacts of extreme Barents Sea air-sea exchanges are examined using the HadCM3 coupled ocean-atmosphere model. Variability in the Barents Sea winter air-sea density flux is found to be a potentially significant factor in determining changes in the southward transport of dense water through Fram Strait. The density flux variability is primarily driven by the thermal term, FT, due to heat loss to the atmosphere. The other two terms (haline flux and ice formation) play a relatively minor role. The difference in ocean circulation between winters with extreme strong and weak Barents Sea surface density flux anomalies is analyzed. This reveals an increase in strong winters of both the north-westward intermediate depth flow out of the basin and the east-west deep flows north of Spitsbergen and south through the Fram Strait. A linear fit yields a Fram Strait southward transport increase of 1.22 Sv for an increase in FT of 1 × 10-6 kg m-2 s-1. For the 10 strongest Barents Sea surface density flux winters, the Fram Strait winter southward transport increases by 2.4 Sv. This compares with a reduction of 1.0 Sv for the corresponding weakest winters. Furthermore, the properties of the southward flowing water are modified in strong density flux winters. In such winters, the Fram Strait water below 250 m is colder by up to 0.5°C and fresher by 0.05 than the climatological winter mean.

  20. Fall 2013 / Winter 2014 Dean's List Faculty of Science, Dalhousie University First Name Last Name Term(s) Erin Dempsey Winter Only

    E-print Network

    Lotze, Heike K.

    and Winter Caitlin Lynch-StauntonWinter Only Jenna Nolan Fall and Winter Kelsey MacNeil Winter Only Lyle'Hanlon Winter Only Kerolos Mousa Abdrabbo Fall and Winter Nicholas Sacre Winter Only Nasser Abdullah Fall and Winter Adam Al-Jumaily Winter Only Ahmad Alqalaf Fall and Winter Dema Al-Razani Winter Only Nicholas

  1. Winter anomaly observations at the Panská Ves Observatory (Czechoslovakia), 1971–1973

    Microsoft Academic Search

    Jan Laštovi?ka; Pavel T?íska; J. Prokop

    1976-01-01

    Summary The results of the winter anomaly observations at the Panská Ves Observatory on 2775 kHz and 2614 kHz (A3 method, feq˜1 and 0.8 MHz) are studied for the winters of 1971\\/72 and 1972\\/73. Ionospheric responses to minor (1972) and major stratospheric warmings are found to be different and relatively small. A regular winter-anomaly background absorption increase with a maximum

  2. Movements of wintering Dunlin Calidris alpina and changing habitat availability in an agricultural wetland landscape

    USGS Publications Warehouse

    Taft, O.W.; Sanzenbacher, P.M.; Haig, S.M.

    2008-01-01

    Few studies have assessed how the dynamics of wetland bird movements relate to changing resource availability, particularly at more than one spatial scale. Within western Oregon's Williamette Valley, we examined winter resident Dunlin Calidris alpina movements in relation to a decrease in availability of preferred shorebird foraging habitat from early to late winter of 1999-2000. By tracking movements of 15 (early winter) and 12 (late winter) radiomarked individuals, we calculated home ranges and characterized presence/absence of a preference for shorebird foraging habitat during each winter period. Between periods, we compared: (1) percentage of shorebird habitat in home ranges to its availability in the landscape (regional preference), (2) percentage of radio locations in shorebird habitat to its availability within home ranges (local preference) and (3) relative use of roost sites. Concurrent with a 75% decrease in available shorebird habitat from early to late winter, average home range sizes increased by a factor of 3.8. At a regional scale, home ranges in early winter included a significantly greater percentage of shorebird foraging habitat than was available in the wider landscape. However, by late winter, the percent of shorebird habitat in home ranges did not match availability in the landscape. At the local scale, for both winter periods Dunlin were located in shorebird foraging habitat more often than expected given availability of habitat within home ranges [Correction added after online pub-lication 23 May 2008: sentence amended]. An increase in the number of roosts used from early to late winter implies possible reliance on additional sites in late winter for foraging opportunities. Results suggest that wet, unvegetated habitat is sought by Dunlin throughout winter, but individuals could not select home ranges in late winter that fully compensated for seasonal loss of habitat. ?? 2008 The Authors.

  3. Charred Forests Increase Snow Albedo Decay: Watershed-Scale Implications of the Postfire Snow Albedo Effect

    NASA Astrophysics Data System (ADS)

    Gleason, K. E.; Nolin, A. W.

    2014-12-01

    Recent work shows that after a high severity forest fire, approximately 60% more solar radiation reaches the snow surface due to the reduction in canopy density. Also, significant amounts of black carbon (BC) particles and larger burned woody debris (BWD) are shed from standing charred trees, which concentrate on the snowpack, darken its surface, and reduce snow albedo by 50% during ablation. The postfire forest environment drives a substantial increase in net shortwave radiation at the snowpack surface, driving earlier and more rapid melt, however hydrologic models do not explicitly incorporate forest fire disturbance effects to snowpack dynamics. In this study we characterized, parameterized, and validated the postfire snow albedo effect: how the deposition and concentration of charred forest debris decreases snow albedo, increases snow albedo decay rates, and drives an earlier date of snow disappearance. For three study sites in the Oregon High Cascade Mountains, a 2-yr old burned forest, a 10-yr burned forest, and a nearby unburned forest, we used a suite of empirical data to characterize the magnitude and duration of the postfire effect to snow albedo decay. For WY 2012, WY2013, and WY2014 we conducted spectral albedo measurements, snow surface sampling, in-situ snow and meteorological monitoring, and snow energy balance modeling. From these data we developed a new parameterization which represents the postfire effect to snow albedo decay as a function of days-since-snowfall. We validated our parameterization using a physically-based, spatially-distributed snow accumulation and melt model, in-situ snow monitoring, net snowpack radiation, and remote sensing data. We modeled snow dynamics across the extent of all burned area in the headwaters of the McKenzie River Basin and validated the watershed-scale implications of the postfire snow albedo effect using in-situ micrometeorological and remote sensing data. This research quantified the watershed scale postfire effects to snow albedo and snow melt in the Oregon High Cascades, and provided a new parameterization of forest fire effects to high elevation winter water storage.

  4. Development of a snowfall–snowmelt routine for mountainous terrain for the soil water assessment tool (SWAT)

    Microsoft Academic Search

    T. A. Fontaine; T. S. Cruickshank; J. G. Arnold; R. H. Hotchkiss

    2002-01-01

    The soil water assessment tool (SWAT) is a hydrologic model originally developed to evaluate water resources in large agricultural basins. SWAT was not designed to model heterogeneous mountain basins typical of the western United States, and as a result, has performed poorly when applied to mountainous locations. The intent of this study was to increase the versatility of SWAT by

  5. The Challenge of Winter Backpacking.

    ERIC Educational Resources Information Center

    Cavanaugh, Michael; Mapes, Alan

    1981-01-01

    Tips and techniques for safe and enjoyable winter backpacking are offered. Topics covered include cross county skis, snowshoes, clothing, footwear, shelter, sleeping bags, food, hypothermia prevention, as well as general rules and requirements. (CO)

  6. Winter Weather Frequently Asked Questions

    MedlinePLUS

    ... Health Matters What's New Preparation & Planning Disasters & Severe Weather Earthquakes Extreme Heat Floods Hurricanes Landslides Tornadoes Tsunamis ... Weather Information on Specific Types of Emergencies Winter Weather Frequently Asked Questions Language: English Español (Spanish) Recommend ...

  7. Winter CO2 fluxes in a boreal forest

    USGS Publications Warehouse

    Winston, G.C.; Sundquist, E.T.; Stephens, B.B.; Trumbore, S.E.

    1997-01-01

    We measured soil respiration during two winters in three different ecotypes of the BOREAS northern study area. The production of CO2 was continuous throughout the winter and, when totaled for the winter of 1994-1995, was equivalent to the release of ???40-55 g C/m2 from the soil surface. As soils cooled in the early winter, the CO2 production rate decreased in a manner that appeared to be exponentially related to shallow soil temperatures. This exponential relationship was not observed when soils began to warm, possibly indicating that there may be additional or different processes responsible for increased CO2 production during winter warming events. We also measured CO2 concentrations in soil gas and the ??14C of the soil CO2. These measurements show that the CO2 produced in winter is not simply the return to the atmosphere of the carbon fixed during the previous growing season. We suggest that the wintertime production of CO2 originates, at least in part, from the decomposition of old organic carbon stored at depth in the soil.

  8. Winter CO2 fluxes in a boreal forest

    NASA Astrophysics Data System (ADS)

    Winston, G. C.; Sundquist, E. T.; Stephens, B. B.; Trumbore, S. E.

    1997-12-01

    We measured soil respiration during two winters in three different ecotypes of the BOREAS northern study area. The production of CO2 was continuous throughout the winter and, when totaled for the winter of 1994-1995, was equivalent to the release of ˜40-55 g C/m2 from the soil surface. As soils cooled in the early winter, the CO2 production rate decreased in a manner that appeared to be exponentially related to shallow soil temperatures. This exponential relationship was not observed when soils began to warm, possibly indicating that there may be additional or different processes responsible for increased CO2 production during winter warming events. We also measured CO2 concentrations in soil gas and the ?14C of the soil CO2. These measurements show that the CO2 produced in winter is not simply the return to the atmosphere of the carbon fixed during the previous growing season. We suggest that the wintertime production of CO2 originates, at least in part, from the decomposition of old organic carbon stored at depth in the soil.

  9. Change in abundance of pacific brant wintering in alaska: evidence of a climate warming effect?

    USGS Publications Warehouse

    Ward, D.H.; Dau, C.P.; Lee, T.; Sedinger, J.S.; Anderson, B.A.; Hines, J.E.

    2009-01-01

    Winter distribution of Pacific Flyway brant (Branta bernicla nigricans) has shifted northward from lowtemperate areas to sub-Arctic areas over the last 42 years. We assessed the winter abundance and distribution of brant in Alaska to evaluate whether climate warming may be contributing to positive trends in the most northern of the wintering populations. Mean surface air temperatures during winter at the end of the Alaska Peninsula increased about 1??C between 1963 and 2004, resulting in a 23% reduction in freezing degree days and a 34% decline in the number of days when ice cover prevents birds from accessing food resources. Trends in the wintering population fluctuated with states of the Pacific Decadal Oscillation, increasing during positive (warm) phases and decreasing during negative (cold) phases, and this correlation provides support for the hypothesis that growth in the wintering population of brant in Alaska is linked to climate warming. The size of the wintering population was negatively correlated with the number of days of strong northwesterly winds in November, which suggests that the occurrence of tailwinds favorable for migration before the onset of winter was a key factor in whether brant migrated from Alaska or remained there during winter. Winter distribution of brant on the Alaska Peninsula was highly variable and influenced by ice cover, particularly at the heavily used Izembek Lagoon. Observations of previously marked brant indicated that the Alaska wintering population was composed primarily of birds originating from Arctic breeding colonies that appear to be growing. Numbers of brant in Alaska during winter will likely increase as temperatures rise and ice cover decreases at high latitudes in response to climate warming. ?? The Arctic Institute of North America.

  10. Winter fuels report

    SciTech Connect

    Not Available

    1995-01-27

    The Winter Fuels Report is intended to provide concise, timely information to the industry, the press, policymakers, consumers, analysis, 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.

  11. Winter fuels report

    SciTech Connect

    Not Available

    1994-10-01

    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.

  12. Winter fuels report

    SciTech Connect

    Not Available

    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.

  13. Winter fuels report

    SciTech Connect

    Not Available

    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.

  14. Distribution patterns during winter and fidelity to wintering areas of American black ducks

    USGS Publications Warehouse

    Diefenbach, D.R.; Nichols, J.D.; Hines, J.E.

    1988-01-01

    The distribution patterns during winter of American black ducks were compared among age-sex classes using band recivery data. In addition, fidelity to wintering areas was compared between sexes and between coastal and inland wintering sites.

  15. Strong Costs and Benefits of Winter Acclimatization in Drosophila melanogaster

    PubMed Central

    Schou, Mads Fristrup; Loeschcke, Volker; Kristensen, Torsten Nygaard

    2015-01-01

    Studies on thermal acclimation in insects are often performed on animals acclimated in the laboratory under conditions that are not ecologically relevant. Costs and benefits of acclimation responses under such conditions may not reflect costs and benefits in natural populations subjected to daily and seasonal temperature fluctuations. Here we estimated costs and benefits in thermal tolerance limits in relation to winter acclimatization of Drosophila melanogaster. We sampled flies from a natural habitat during winter in Denmark (field flies) and compared heat and cold tolerance of these to that of flies collected from the same natural population, but acclimated to 25 °C or 13 °C in the laboratory (laboratory flies). We further obtained thermal performance curves for egg-to-adult viability of field and laboratory (25 °C) flies, to estimate possible cross-generational effects of acclimation. We found much higher cold tolerance and a lowered heat tolerance in field flies compared to laboratory flies reared at 25 °C. Flies reared in the laboratory at 13 °C exhibited the same thermal cost-benefit relations as the winter acclimatized flies. We also found a cost of winter acclimatization in terms of decreased egg-to-adult viability at high temperatures of eggs laid by winter acclimatized flies. Based on our findings we suggest that winter acclimatization in nature can induce strong benefits in terms of increased cold tolerance. These benefits can be reproduced in the laboratory under ecologically relevant rearing and testing conditions, and should be incorporated in species distribution modelling. Winter acclimatization also leads to decreased heat tolerance. This may create a mismatch between acclimation responses and the thermal environment, e.g. if temperatures suddenly increase during spring, under current and expected more variable future climatic conditions. PMID:26075607

  16. Scenario-based risk analysis of winter snowstorms in the German lowlands

    NASA Astrophysics Data System (ADS)

    von Wulffen, Anja

    2014-05-01

    The northern German lowlands are not especially known for a high frequency of snowfall events. Nevertheless under certain synoptic conditions Lake-Effect-like phenomena caused by the proximity especially of the Baltic Sea can lead to significantly reinforced snowfall intensities that are often accompanied by rather high wind speeds. This makes for infrequent but potentially disastrous snowstorms in a region less accustomed to snow impacts. One possible consequence of an infrastructure failure cascade resulting from severe and longer-lasting snowstorms is a regional disruption of the food supply chain. In the context of "just-in-time"-logistics and the accompanying decrease of storage capabilities, this poses a significant threat to the population's food security. Within the project NeuENV ("New strategies to ensure sufficient food supply in case of crisis in Germany") a snowstorm in the German lowlands involving widespread disruptions of the transportation infrastructure as well as power failures is therefore used as one model for future food supply chain disruptions. In order to obtain a reliable evaluation of the supply chain and crisis management resilience, a detailed snowstorm scenario is being developed. For this purpose, a database of impact reports of past snowstorm events is assembled and analysed to obtain a comprehensive overview of potential infrastructure impairments and failures. Examples of events analysed in this context include the winter 1978/79 with its disastrous snow drifts that commonly attained heights of 3m to 5m leading to a transportation infrastructure collapse across a wide area, the wet snow event in November 2005 in the Münsterland region that caused power failures for up to 250.000 homes, and more recent snowstorms such as Daisy in January 2010. A catalogue of thresholds for relevant parameters indicating when significant failures can be expected is then compiled through a comparison of impact reports with the detailed meteorological conditions. Based on these findings, an exemplary synoptic evolution of a snowstorm leading to representative infrastructure failure cascades is constructed. In a next step, an extrapolation of this obtained scenario to future climate and societal conditions as well as plausible more extreme but not yet observed meteorological conditions is planned in order to obtain a thorough analysis of possible threats to the German food distribution system and a strong foundation for future disaster mitigation planning efforts.

  17. The Impact of Winter Heating on Air Pollution in China

    PubMed Central

    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

  18. The impact of winter heating on air pollution in China.

    PubMed

    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

  19. Winter anomaly in ionospheric absorption of radio waves over half a sunspot cycle

    Microsoft Academic Search

    B. M. Patel; J. C. Patel; K. M. Kotadia

    1973-01-01

    The winter anomaly in ionospheric absorption is studied at a mid-latitude station over half a solar cycle. It is shown that the anomalous increases of absorption on some days in winter are better correlated with 10 mb-level geopotential height than with temperature at that level. The anomaly is most marked in the month of January. It was about 168% in

  20. Evidence for continued transmission of parasitic nematodes in reindeer during the Arctic winter

    Microsoft Academic Search

    O Halvorsen; A Stien; J Irvine; R Langvatn; S Albon

    1999-01-01

    Living in the high Arctic, the Svalbard reindeer (Rangifer tarandus platyrhynchus) and its trichostrongyle nematodes experience a long cold winter from October to late May\\/early June. Over this period, transmission would be expected to be low. However, in culled reindeer the abundance of infection increased from autumn to late winter, providing evidence for continued transmission within this period. To our

  1. Wintering habitat use by houbara bustards Chlamydotis undulata in Abu Dhabi and implications for management

    Microsoft Academic Search

    Patrick E. Osborne; Frédéric Launay; Derek Gliddon

    1997-01-01

    Houbara bustards Chlamydotis undulata are uncommon winter visitors to Abu Dhabi. People attempting to increase numbers are considering establishing reserves and restoring habitats but they are hampered by poor knowledge of the bird's requirements. We studied winter habitat use by recording the locations of three satellite-tagged houbara, verified by the presence of tracks, and detailed habitat assessments at the landscape

  2. Increasing biomass of winter wheat using sorghum biochars

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The fertility of highly weathered Ultisols in the southeastern Coastal Plain region of United States is low. In this region, intensive crop production depletes soil nutrients and reduces soil organic carbon (C). Application of crop residues in agricultural systems is an important factor in the contr...

  3. Physiological responses of Yellowstone bison to winter nutritional deprivation

    USGS Publications Warehouse

    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 < 0.001) trends of urinary potassium: 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.

  4. Incidence of mass movement processes after an historical episode of heavy snowfall in the Asturian Massif (Northern Spain)

    NASA Astrophysics Data System (ADS)

    Garcia-Hernandez, Cristina; Ruiz-Fernández, Jesús; Gallinar, David

    2015-04-01

    This research examines a mass movement event caused in the context of the Great Blizzard of 1888, one of the most severe recorded blizzards in the history of Europe, whose implications go far beyond. In the Asturian Massif the episode consisted in four linked and consecutive snowstorms that took place between the 14th of February 1888 and the 8th of April 1888, creating snow covers with a depth ranging between 5 and 7 m, snow avalanches and flooding, causing dozens of deaths and large material damage. The Asturian Massif belongs to the Atlantic-climate area and is composed mainly by sedimentary and metamorphic paleozoic rocks. Many sectors of the Massif are between 1.000 and 2.000 m a.s.l., and its topography is characterized by a great height difference and steep slopes. Because of the lack of deep soils suitable for farming, the main traditional activity has been livestock keeping, and goods traffic. We have devised a method that enables the reconstruction of this event on the basis of nivo-meteorogical conditions, geographical location and socio-economic impact. The mass movement episode has been studied through the issues of 6 newspapers published in Asturias between the 20th of January and 30th of May 1888, the ancient meteorological station data of the University of Oviedo, and field work. A logical database structure has been designed with the aim to store and cross the information for statistical analysis. Thirty six mass movement worthy of consideration were documented, 28 of them causing material damage (six homes destroyed and at least 22 interruptions with the traffic flow on roads, highways and railways). Ten high- and mid-elevation mountain municipalities were affected by mass movement. We must consider that only the most important events, or those that happened in crowded places, have been considered by the newspapers, so the total number of mass movements should be considered as a minimum figure. We have got to identify and classify 27 of them; 16 as landslides, 5 as rockfalls, 4 as mixed typology of rockfalls with a big amount of mud, and 2 as debris flow. One person died as a consecuence of a rockfall. Thirty out of thirty six events anthropic intervention is proved. It acted as a prior conditioning where the previous topography has been modified (in 29 cases), either as a direct triggering mechanism at least in one landslide episode. The sequence analysis of the events shows that their number and frequency increases with episodes of snow melting during the snowstorm breaks, announcing the highest instabilities on 10th and 11th of March, coinciding with a rainfall peak. However the connection with the rainfall episode seems weak compared with the one than can be settled with the rise of temperatures and the resulting melting intensification. It caused the progressive water saturation of surface formations, that reached a maximum during the second break, triggering 20 events during the 11th of March 1888.

  5. A Large-Droplet Mode and Prognostic Number Concentration of Cloud Droplets in the Colorado State University Regional Atmospheric Modeling System (RAMS). Part II: Sensitivity to a Colorado Winter Snowfall Event

    Microsoft Academic Search

    Stephen M. Saleeby; William R. Cotton

    2005-01-01

    This paper is the second in a two-part series describing recent additions to the microphysics module of the Regional Atmospheric Modeling System (RAMS) at Colorado State University. These changes include the addition of a large-cloud-droplet mode (40-80 m in diameter) into the liquid-droplet spectrum and the parameterization of cloud-droplet nucleation through activation of cloud condensation nuclei (CCN) and giant CCN

  6. Winter Break Activities and Attractions Fighting the Winter Blues

    E-print Network

    Mountziaris, T. J.

    -oriented at night - Fireworks; midnight "ball-raising" at Hotel Northampton - Festival of the arts: a single bargain and veggies at the Amherst Winter Farmer's Market - Saturdays 10-2pm at the Amherst Regional Middle School Y World Class Markets with Big Y Express Cards $14 with Silver Coin/Card o $16 with Big Y Express

  7. Winter cover crops impact on corn production in semiarid regions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cover crops have been proposed as a technique to increase soil health. This study examined the impact of winter brassica cover crop cocktails grown after wheat (Triticum aestivum) on corn yields; corn yield losses due to water and N stress; soil bacteria to fungi ratios; mycorrhizal markers; and ge...

  8. THE URBAN HEAT ISLAND IN WINTER AT BARROW, ALASKA

    Microsoft Academic Search

    KENNETH M. HINKEL; FREDERICK E. NELSON; JULIANNE H. BELLa

    The village of Barrow, Alaska, is the northernmost settlement in the USA and the largest native community in the Arctic. The population has grown from about 300 residents in 1900 to more than 4600 in 2000. In recent decades, a general increase of mean annual and mean winter air temperature has been recorded near the centre of the village, and

  9. Registration of 'NI04421' hard red winter wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water for irrigation is a major constraint in the Great Plains and it is expected that the proportion of irrigated crop land to grow irrigated wheat will increase to conserve irrigation water. 'NI04421' (Reg. No. PI 659690) hard red winter wheat (Triticum aestivum L.) was developed cooperatively by...

  10. Evapotranspiration of deficit irrigated sorghum and winter wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Deficit irrigation commonly is used in regions with reduced or limited irrigation capacity to increase water use efficiency (WUE). This research measured winter wheat (Triticum aestivum L.) and sorghum (Sorghum bicolor L. Moench) water use (ET) and yields so WUE could be determined. Two precision ...

  11. Small Grain Winter Cover Crops for Corn and Soybean

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Winter cover crops are plants that cover the soil between harvest and planting of summer annual grain crops. While doing this, cover crops perform important environmental functions that include reducing soil erosion, accumulating nutrients, and increasing soil carbon. This educational module provide...

  12. KPI Graduate Executive Summary Report, Summer 2000-Winter 2001.

    ERIC Educational Resources Information Center

    Sheridan Coll. (Ontario).

    Summarizes findings from the Key Performance Indicator Satisfaction Survey administered by Sheridan College in the summer 2000, fall 2000, and winter 2001 terms. This survey was administered in compliance with the Ontario government's efforts to increase the accountability of the Colleges of Applied Arts and Technology through the measurement of…

  13. Winter carbon dioxide fluxes in humid-temperate pastures

    Microsoft Academic Search

    Howard Skinner

    2007-01-01

    Because of their vast size, grazing lands have the potential to sequester significant quantities of carbon, slowing the increase in atmospheric CO2 and reducing the risk of global warming. Although CO2 uptake during the growing season can be substantial, losses during winter months reduce annual sequestration, potentially turning grazing lands into net carbon sources. The goal of this research was

  14. Size-Related, First Winter Mortality of Freshwater Fishes

    Microsoft Academic Search

    Michael L. Toneys; Daniel W. Coble

    1979-01-01

    To determine if first winter mortality were greater for small than for large freshwater fish, we conducted eight experiments in lakes and hatchery ponds during which fish were measured in late fall and early spring. Overwinter increase in mean length of the bluegill, Lepomis macrochirus, in one lake and largemouth bass, Micropterus salmoides, in another could have been caused by

  15. Registration of 'NE01481' hard red winter wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    'NE01481' (Reg. No. PI 659689) hard red winter wheat (Triticum aestivum L.) was developed cooperatively by the Nebraska Agricultural Experiment Station and the USDA-ARS and released in April, 2010. Nebraska wheat growers, in addition to superior agronomic performance, would like to have increased r...

  16. Bromus species in winter wheat-population dynamics and competitiveness.

    PubMed

    Moray, R; Büchse, A; Hurle, K

    2003-01-01

    The infestation of Bromus species in small grains, especially in winter cereals has increased over recent years. In some areas winter wheat growers consider Bromus spp. as their worst grass weed. Besides yield reduction, Bromus spp. cause lodging and complication of harvest. In Germany the two most dominant species are Bromus sterilis (L.) and Bromus secalinus (L.). In order to develop control strategies the population dynamics of the weeds were investigated. Based on the results a deterministic mathematical model using differential and algebraic equations was used to estimate changes in the population of the two Bromus species. PMID:15149129

  17. Daily movements of female mallards wintering in Southwestern Louisiana

    USGS Publications Warehouse

    Link, P.T.; Afton, A.D.; Cox, R.R., Jr.; Davis, B.E.

    2011-01-01

    Understanding daily movements of waterfowl is crucial to management of winter habitats, especially along the Gulf Coast where hunting pressure is high. Radio-telemetry was used to investigate movements of female Mallards (Anas platyrchychos) wintering in southwestern Louisiana. Movement distances were analyzed from 2,455 paired locations (diurnal and nocturnal) of 126 Mallards during winters 2004-2005 and 2005-2006 to assess effects of winter, female age, areas closed (Lacassine National Wildlife Refuge [LAC], Cameron Prairie National Wildlife Refuge [CAM], Amoco Pool [AMOCO] or open to hunting [OPEN]), and habitat type, including all interactions. Movement distances from the various land management categories were not consistent by age, date, or by winter. Flight distances from LAC increased with date, whereas those from CAM and OPEN did not vary significantly by date. Female Mallards moved short distances between diurnal and nocturnal sites (ranging from 3.1 to 15.0 km by land management category), suggesting that they are able to meet their daily energy requirements within a smaller area than Northern Pintails (Anas acuta, hereafter Pintails), and thus minimize transit energy costs.

  18. Mass dynamics of wintering Pacific Black Brant: Body, adipose tissue, organ, and muscle masses vary with location

    USGS Publications Warehouse

    Mason, D.D.; Barboza, P.S.; Ward, D.H.

    2007-01-01

    We compared body size and mass of the whole body, organs, adipose tissue, and muscles of adult Pacific Black Brant (Branta bernicla nigricans (Lawrence, 1846)) collected concurrently in Alaska and Baja California during the fall, winter, and spring of 2002-2003. Head and tarsal lengths of males were similar between sites and slightly larger for females in Alaska than in Baja California. Brant appear to operate under similar physiological bounds, but patterns of nutrient allocation differ between sites. Birds wintering in Alaska lost similar amounts of adipose tissue during early winter as birds in Baja California gained during late winter before migration. Masses of the body, adipose tissue, and flight muscles during mid-winter were similar between sites. Seasonal adipose tissue deposition may, therefore, equally favor winter residency or long-distance migration. Gonad and liver masses increased in late winter for birds in Alaska but not for those in Baja California, suggesting birds wintering in Baja may delay reproductive development in favor of allocating reserves needed for migration. Phenotypic flexibility allows Brant to use widely divergent wintering sites. The wintering location of Brant likely depends more upon changes in environmental conditions and food availability, than upon physiological differences between the two wintering populations. ?? 2007 NRC.

  19. MSU University News Winter pea and lentil offer growers a way to diversify winter

    E-print Network

    Maxwell, Bruce D.

    MSU University News Winter pea and lentil offer growers a way to diversify winter wheat systems August 13, 2003 Ag researchers are studying winter peas and lentils to see whether they offer enough yield advantage over spring peas and lentils that they would make a better rotation choice for winter

  20. Britannica Sporting Record: The Winter Games

    NSDL National Science Digital Library

    Encyclopaedia Britannica, Inc.

    Encyclopaedia Britannica's Olympic Winter Games site offers detailed Olympic information and history. Offerings include an overview of the Olympic movement, histories of each of the past seventeen Olympic Winter Games, articles about the events included in the Winter Games, biographies of past competitors, and a searchable Olympic Record database. This well-researched site provides an interesting backdrop for this year's Winter Games in Nagano, Japan.

  1. Varietal Trials Results Wheat, Hard Red Winter

    E-print Network

    Thomas, David D.

    Varietal Trials Results Wheat, Hard Red Winter 47 Winter wheat varieties were compared in trial plots at Crookston, Lamberton, Roseau and St. Paul. Wheat varieties were grown in replicated plots. These winter wheat trials are not designed for crop (species) compar- isons because the various crops are grown

  2. CULTIVAR DESCRIPTION CDC Kestrel winter wheat

    E-print Network

    Saskatchewan, University of

    CULTIVAR DESCRIPTION CDC Kestrel winter wheat D. B. Fowler Crop Development Centre, University 17 December 1996, accepted 12 August 1997. Fowler, D. B. 1997. CDC Kestrel winter wheat. Can. J. Plant Sci. 77: 673­675. CDC Kestrel is a lodging-resistant, high-yielding, semidwarf winter wheat

  3. CULTIVAR DESCRIPTION CDC Clair winter wheat

    E-print Network

    Saskatchewan, University of

    CULTIVAR DESCRIPTION CDC Clair winter wheat D. B. Fowler Crop Development Centre, University 17 December 1996, accepted 12 August 1997. Fowler, D. B. 1997. CDC Clair winter wheat. Can. J. Plant Sci. 77: 669­671. CDC Clair is a high-yielding, strong-strawed, semi- dwarf winter wheat (Triticum

  4. Shifting covariability of North American summer monsoon precipitation with antecedent winter precipitation

    USGS Publications Warehouse

    McCabe, G.J.; Clark, M.P.

    2006-01-01

    Previous research has suggested that a general inverse relation exists between winter precipitation in the southwestern United states (US) and summer monsoon precipitation. In addition, it has been suggested that this inverse relation between winter precipitation and the magnitude of the southwestern US monsoon breaks down under certain climatic conditions that override the regional winter/monsoon precipitation relations. Results from this new study indicate that the winter/monsoon precipitation relations do not break down, but rather shift location through time. The strength of winter/monsoon precipitation relations, as indexed by 20-year moving correlations between winter precipitation and monsoon precipitation, decreased in Arizona after about 1970, but increased in New Mexico. The changes in these correlations appear to be related to an eastward shift in the location of monsoon precipitation in the southwestern US. This eastward shift in monsoon precipitation and the changes in correlations with winter precipitation also appear to be related to an eastward shift in July/August atmospheric circulation over the southwestern US that resulted in increased monsoon precipitation in New Mexico. Results also indicate that decreases in sea-surface temperatures (SSTs) in the central North Pacific Ocean also may be associated with th changes in correlations between winter and monsoon precipitation. Copyright ?? 2006 Royal Meteorological Society.

  5. The transformation of frequency distributions of winter precipitation to spring streamflow probabilities in cold regions; case studies from the Canadian Prairies

    NASA Astrophysics Data System (ADS)

    Shook, Kevin; Pomeroy, John; van der Kamp, Garth

    2015-02-01

    Hydrological processes alter the states and/or locations of water, and so they can be regarded as being transformations of the properties of the time series of input variables to those of output variables, such as the transformation of precipitation to streamflow. Semi-arid cold regions such as the Canadian Prairies have extremely low annual streamflow efficiencies because of high infiltration rates, large surface water storage capacities, high evaporation rates and strong climate seasonality. As a result snowfall produces the majority of streamflow. It is demonstrated that the probability distributions of Prairie spring streamflows are controlled by three frequency transformations. The first is the transformation of snowfall by wind redistribution and ablation over the winter to form the spring snowpack. The second transformation is the melt of the spring snowpack to produce runoff over frozen agricultural soils. The third is the transformation of runoff to streamflow by the filling and spilling of depressional storage by connecting fields, ponds, wetlands and lakes. Each transformation of the PDF of the input variable to that of the output variable is demonstrated at a number of locations in the Canadian Prairies and is explained in terms of the hydrological processes causing the transformation. The resulting distributions are highly modified from that of precipitation, and the modification depends on which processes dominate streamflow formation in each basin. The results demonstrate the need to consider the effect of the interplay among hydrological processes, climate and basin characteristics in transforming precipitation frequency distributions into those of streamflow for the design of infrastructure and for water management.

  6. Winter 2010 EVENTS FOCUS: RUSSIA

    E-print Network

    Eustice, Ryan

    Winter 2010 EVENTS FOCUS: RUSSIA Tue, Jan 12, 4-5:30 pm WCED/CREES/Ford School Lecture. "U.S.-Russia Relations: Status of the `Reset'." John Beyrle, U.S. Ambassador to Russia. Co-sponsors: International Policy and literature, Oberlin College. Wed, Feb 3, 12-1:30 pm CREES Brown Bag. "Nostalgia in Post-Socialist Russia

  7. Winter 1998 UC SANTA CRUZ

    E-print Network

    California at Santa Cruz, University of

    Winter 1998 UC SANTA CRUZ T O D AY ' S S T U D E N T S Plus: elementary school kids discover the university, behind-the-scenes learning, building the tools of modern astronomy R E V I E W #12;s chancellor that it is--that one important measure of the vitality of any university is the caliber of students

  8. ASIAN DEVELOPMENT ECONOMICS Winter 2014

    E-print Network

    Carter, John

    ASIAN DEVELOPMENT ECONOMICS ECON 375 Winter 2014 INSTRUCTOR: Dr. Meenakshi Rishi OFFICE HOURS: 296-2078 EMAIL: rishim@seattleu.edu COURSE DESCRIPTION: The Asian continent is home to more than half of the individual experiences of different Asian countries as they have grown and developed since the 1960s

  9. Ecological Genetics Winter Term 2010

    E-print Network

    Adl, Sina

    slides, and other communications, announcements, etc. Lectures : Monday, Wednesday and Friday, 1BIOL 3044 Ecological Genetics Winter Term 2010 Course Outline Course Description The interface.Latta@Dal.ca Course Webpage: http://ucis.dal.ca/services/other_services/ILO/ I will use a BLS web site to post lecture

  10. Shifting mirrors: adaptive changes in retinal reflections to winter darkness in Arctic reindeer.

    PubMed

    Stokkan, Karl-Arne; Folkow, Lars; Dukes, Juliet; Neveu, Magella; Hogg, Chris; Siefken, Sandra; Dakin, Steven C; Jeffery, Glen

    2013-12-22

    Arctic reindeer experience extreme changes in environmental light from continuous summer daylight to continuous winter darkness. Here, we show that they may have a unique mechanism to cope with winter darkness by changing the wavelength reflection from their tapetum lucidum (TL). In summer, it is golden with most light reflected back directly through the retina, whereas in winter it is deep blue with less light reflected out of the eye. The blue reflection in winter is associated with significantly increased retinal sensitivity compared with summer animals. The wavelength of reflection depends on TL collagen spacing, with reduced spacing resulting in shorter wavelengths, which we confirmed in summer and winter animals. Winter animals have significantly increased intra-ocular pressure, probably produced by permanent pupil dilation blocking ocular drainage. This may explain the collagen compression. The resulting shift to a blue reflection may scatter light through photoreceptors rather than directly reflecting it, resulting in elevated retinal sensitivity via increased photon capture. This is, to our knowledge, the first description of a retinal structural adaptation to seasonal changes in environmental light. Increased sensitivity occurs at the cost of reduced acuity, but may be an important adaptation in reindeer to detect moving predators in the dark Arctic winter. PMID:24174115

  11. Forage kochia (Kochia Prostrata) increases nutritional value, carrying capacity, and livestock performance on semiarid rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extending the grazing season into the fall and winter increases the sustainability of livestock production by reducing winter feed costs. However, without exception, stockpiled range grasses do not meet nutritional requirements for ruminant livestock. This study compared fall/winter grazing of tra...

  12. The History of Winter and the Global Snowflake Network, Engaging Teachers and Students in Science Field Research in Snow and Ice

    NASA Astrophysics Data System (ADS)

    Bender, K. J.; Wasilewski, P. J.; Gabrys, R. E.

    2006-05-01

    A weeklong Professional development/"Teacher as scientist" Cryosphere science training camp held annually in February in Lake Placid, NY, the History of Winter program (HOW) has been serving teachers in the NASA Goddard Space Flight Center service area since 2000. Currently, HOW participants include university faculty interested in enhancing their pre-service science education programs, in-service teachers and pre-service education students. HOW utilizes a stratified professional development approach to science content mastery and delivery while involving participants in scientific field research. Each year program components and resources are added to HOW to provide continued, sustainable interest in the program and to support participants as they continue their HOW experience. An offshoot of the HOW Program, the Global Snowflake Network (GSN) launched in the winter of 2006 engages an international audience including both formal and informal education groups. The goal is to provide an interactive online data resource in science and education for the characterization of snowfall and related weather systems. The Global Snowflake Network has been accepted as an education outreach proposal for the International Polar Year. Collaborations with other agencies and universities also with IPY-accepted proposals are now underway. HOW and the GSN are endorsed by the NASA Goddard Education Office and many of the Goddard Snow and Ice scientists. Together these programs offer a unique, sustainable, and proven outreach for the Cryosphere research program.

  13. Studless Winter Tires

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Goodyear Tire and Rubber Company developed a material for Johnson Space Center used as parachute shrouds to soft land the Vikings through the tenuous Martian atmosphere and has been adapted to new radial tire five times stronger than steel. Fiber has a chain-like molecular structure that gives it incredible strength in proportion to its weight. Material is expected to increase tread life by 10,000 miles.

  14. Winter speed-up of quiescent surge-type glaciers in Yukon, Canada

    NASA Astrophysics Data System (ADS)

    Abe, T.; Furuya, M.

    2015-06-01

    Glacier surges often initiate in winter, but the mechanism remains unclear in contrast to the well-known summer speed-up at normal glaciers. To better understand the mechanism, we used radar images to examine spatial-temporal changes in the ice velocity of surge-type glaciers near the border of Alaska and the Yukon, focusing on their quiescent phase. We found significant accelerations in the upstream region from autumn to winter, regardless of surging episodes. Moreover, the winter speed-up propagated from upstream to downstream. Given the absence of surface meltwater input in winter, we suggest the presence of water storage near the base that does not directly connect to the surface, yet can promote basal sliding through increased water pressure. Our findings have implications for the modelling of glacial hydrology in winter, which may help us better understand glacier dynamics.

  15. Electron densities during winter anomalous absorption of different intensity observed at 37.1 deg N, 6.73 deg W, during winter 1975\\/76. I, II

    Microsoft Academic Search

    H. U. Widdel; G. Rose; K. Spenner; M. Friedrich; K. M. Torkar

    1979-01-01

    The paper describes in situ measurements of electron concentration in the D-region of the ionosphere obtained with various probe techniques during the Western European Winter Anomaly Campaign in 1975\\/76. Electron density profiles were measured when the amount of absorption was low, medium, or winter-anomalous at time of launch. The electron density increased at heights between 75 and 95 km when

  16. Abrupt Decline in the Arctic Winter Sea Ice Cover

    NASA Technical Reports Server (NTRS)

    Comiso, Josefino C.

    2007-01-01

    Maximum ice extents in the Arctic in 2005 and 2006 have been observed to be significantly lower (by about 6%) than the average of those of previous years starting in 1979. Since the winter maxima had been relatively stable with the trend being only about -1.5% per decade (compared to about -10% per decade for the perennial ice area), this is a significant development since signals from greenhouse warming are expected to be most prominent in winter. Negative ice anomalies are shown to be dominant in 2005 and 2006 especially in the Arctic basin and correlated with winds and surface temperature anomalies during the same period. Progressively increasing winter temperatures in the central Arctic starting in 1997 is observed with significantly higher rates of increase in 2005 and 2006. The Atlantic Oscillation (AO) indices correlate weakly with the sea ice and surface temperature anomaly data but may explain the recent shift in the perennial ice cover towards the western region. Results suggest that the trend in winter ice is finally in the process of catching up with that of the summer ice cover.

  17. Density- and Size-Dependent Winter Mortality and Growth of Late Chaoborus flavicans Larvae

    PubMed Central

    Schröder, Arne

    2013-01-01

    Winter processes such as overwinter survival and growth of individuals can have wide-ranging consequences for population dynamics and communities within and across seasons. In freshwater organisms winter processes have been mainly studied in fish despite that invertebrates also have substantial impacts on lake and pond food webs. One of the major invertebrate consumers in lake and ponds is the planktonic larvae of the dipteran insect Chaoborus spec. However, while much is known about Chaoborus feeding ecology, behaviour and structuring role in food webs, its winter ecology and how it affects its populations are poorly understood. Here size- and density-dependent winter mortality and body growth of late Chaoborus flavicans larvae were quantified over naturally occurring size and density ranges in autumn and under natural winter conditions using two field enclosure experiments. Winter mortality increased with autumn density but decreased with autumn body size while winter growth rates decreased with autumn density and body sizes. There was also a density- and size-independent background mortality component. The proportion of pupae found in spring decreased strongly and exponentially with autumn density. These results may explain the commonly observed univoltine life cycle and multi-annual density fluctuations in northern Chaoborus populations. They further demonstrate the relevance of winter processes and conditions for freshwater invertebrates and ecosystems. PMID:24124517

  18. Monitoring the global-scale winter anomaly of total electron contents using GPS data

    NASA Astrophysics Data System (ADS)

    Huo, X. L.; Yuan, Y. B.; Ou, J. K.; Zhang, K. F.; Bailey, G. J.

    2009-08-01

    The winter anomaly phenomenon of Total Electron Contents (TEC) at latitudes 15°-60°N and 15°S-60°S is presented using GPS carrier-phase data obtained from GPS stations during 2002. The correlation between the [O/N2] ratio estimated using the NRLMSISE-00 atmospheric model and the TEC winter anomaly is also investigated. The numerical results show that the TEC winter anomaly in different regions of the world tends to be dominated by different factors. In North America, the TEC winter anomaly is strongly affected by the magnetospheric processes in high latitudes and the [O/N2] ratio. In the Euro-Africa and Russia-Asia regions, the TEC winter anomaly depends mainly on the [O/N2] ratio at the latitude band of 30°-60°N, and the extent of the TEC winter anomaly gradually decreases from 60°N to 30°N. The extent of the TEC winter anomaly increases at the latitude band of 15°-30°N due to the influence of the meridional neutral wind and the seasonal changes of the subsolar point. However, the TEC winter anomaly was not observed in southern hemisphere in 2002. The TEC equinoctial asymmetries in the northern and southern hemisphere are also presented using GPS TEC values collected in March and September 2002.

  19. Climate change in our backyards: the reshuffling of North America's winter bird communities.

    PubMed

    Princé, Karine; Zuckerberg, Benjamin

    2015-02-01

    Much of the recent changes in North American climate have occurred during the winter months, and as result, overwintering birds represent important sentinels of anthropogenic climate change. While there is mounting evidence that bird populations are responding to a warming climate (e.g., poleward shifts) questions remain as to whether these species-specific responses are resulting in community-wide changes. Here, we test the hypothesis that a changing winter climate should favor the formation of winter bird communities dominated by warm-adapted species. To do this, we quantified changes in community composition using a functional index--the Community Temperature Index (CTI)--which measures the balance between low- and high-temperature dwelling species in a community. Using data from Project FeederWatch, an international citizen science program, we quantified spatiotemporal changes in winter bird communities (n = 38 bird species) across eastern North America and tested the influence of changes in winter minimum temperature over a 22-year period. We implemented a jackknife analysis to identify those species most influential in driving changes at the community level and the population dynamics (e.g., extinction or colonization) responsible for these community changes. Since 1990, we found that the winter bird community structure has changed with communities increasingly composed of warm-adapted species. This reshuffling of winter bird communities was strongest in southerly latitudes and driven primarily by local increases in abundance and regional patterns of colonization by southerly birds. CTI tracked patterns of changing winter temperature at different temporal scales ranging from 1 to 35 years. We conclude that a shifting winter climate has provided an opportunity for smaller, southerly distributed species to colonize new regions and promote the formation of unique winter bird assemblages throughout eastern North America. PMID:25322929

  20. Assessing winter cover crop nutrient uptake efficiency using a water quality simulation model

    NASA Astrophysics Data System (ADS)

    Yeo, I.-Y.; Lee, S.; Sadeghi, A. M.; Beeson, P. C.; Hively, W. D.; McCarty, G. W.; Lang, M. W.

    2013-11-01

    Winter cover crops are an effective conservation management practice with potential to improve water quality. Throughout the Chesapeake Bay Watershed (CBW), which is located in the Mid-Atlantic US, winter cover crop use has been emphasized and federal and state cost-share programs are available to farmers to subsidize the cost of winter cover crop establishment. The objective of this study was to assess the long-term effect of planting winter cover crops at the watershed scale and to identify critical source areas of high nitrate export. A physically-based watershed simulation model, Soil and Water Assessment Tool (SWAT), was calibrated and validated using water quality monitoring data and satellite-based estimates of winter cover crop species performance to simulate hydrological processes and nutrient cycling over the period of 1991-2000. Multiple scenarios were developed to obtain baseline information on nitrate loading without winter cover crops planted and to investigate how nitrate loading could change with different winter cover crop planting scenarios, including different species, planting times, and implementation areas. The results indicate that winter cover crops had a negligible impact on water budget, but significantly reduced nitrate leaching to groundwater and delivery to the waterways. Without winter cover crops, annual nitrate loading was approximately 14 kg ha-1, but it decreased to 4.6-10.1 kg ha-1 with winter cover crops resulting in a reduction rate of 27-67% at the watershed scale. Rye was most effective, with a potential to reduce nitrate leaching by up to 93% with early planting at the field scale. Early planting of winter cover crops (~30 days of additional growing days) was crucial, as it lowered nitrate export by an additional ~2 kg ha-1 when compared to late planting scenarios. The effectiveness of cover cropping increased with increasing extent of winter cover crop implementation. Agricultural fields with well-drained soils and those that were more frequently used to grow corn had a higher potential for nitrate leaching and export to the waterways. This study supports the effective implement of winter cover crop programs, in part by helping to target critical pollution source areas for winter cover crop implementation.

  1. Assessing winter cover crop nutrient uptake efficiency using a water quality simulation model

    USGS Publications Warehouse

    Yeo, In-Young; Lee, Sangchui; Sadeghi, Ali M.; Beeson, Peter C.; Hively, Wells D.; McCarty, Greg W.; Lang, Megan W.

    2013-01-01

    Winter cover crops are an effective conservation management practice with potential to improve water quality. Throughout the Chesapeake Bay Watershed (CBW), which is located in the Mid-Atlantic US, winter cover crop use has been emphasized and federal and state cost-share programs are available to farmers to subsidize the cost of winter cover crop establishment. The objective of this study was to assess the long-term effect of planting winter cover crops at the watershed scale and to identify critical source areas of high nitrate export. A physically-based watershed simulation model, Soil and Water Assessment Tool (SWAT), was calibrated and validated using water quality monitoring data and satellite-based estimates of winter cover crop species performance to simulate hydrological processes and nutrient cycling over the period of 1991–2000. Multiple scenarios were developed to obtain baseline information on nitrate loading without winter cover crops planted and to investigate how nitrate loading could change with different winter cover crop planting scenarios, including different species, planting times, and implementation areas. The results indicate that winter cover crops had a negligible impact on water budget, but significantly reduced nitrate leaching to groundwater and delivery to the waterways. Without winter cover crops, annual nitrate loading was approximately 14 kg ha?1, but it decreased to 4.6–10.1 kg ha?1 with winter cover crops resulting in a reduction rate of 27–67% at the watershed scale. Rye was most effective, with a potential to reduce nitrate leaching by up to 93% with early planting at the field scale. Early planting of winter cover crops (~30 days of additional growing days) was crucial, as it lowered nitrate export by an additional ~2 kg ha?1 when compared to late planting scenarios. The effectiveness of cover cropping increased with increasing extent of winter cover crop implementation. Agricultural fields with well-drained soils and those that were more frequently used to grow corn had a higher potential for nitrate leaching and export to the waterways. This study supports the effective implement of winter cover crop programs, in part by helping to target critical pollution source areas for winter cover crop implementation.

  2. Writing TAFS for Winter Weather

    NSDL National Science Digital Library

    COMET

    2009-09-22

    "Writing TAFs for Winter Weather" is the fourth unit in the Distance Learning Aviation Course 2 (DLAC2) series on producing TAFs that meet the needs of the aviation community. In addition to providing information about tools for diagnosing winter weather and its related impacts, the module extends the Practically Perfect TAF (PPTAF) process to address an airport’s operational thresholds. By understanding the thresholds at airports for which they produce TAFs, forecasters will be better able to produce a PPTAF. The unit also examines how to communicate effectively the logic and uncertainty using the aviation forecast discussion (AvnFD) and addresses maintaining an effective TAF weather watch and updating the TAF proactively.

  3. Stimulation of Phospholipid Biosynthesis during Frost Hardening of Winter Wheat.

    PubMed

    Willemot, C

    1975-02-01

    Lipids were labeled with (33)P during frost hardening of two varieties of winter wheat (Triticum aestivum), hardy Kharkov and much less hardy Champlein. The main labeled compounds were phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, and phosphatidylglycerol. With time of incorporation the proportion of the radioactivity incorporated into the lipids increased in phosphatidylcholine, especially in Kharkov and at 1 C. During hardening, phospholipid synthesis was greatly stimulated in Kharkov, but much less in Champlein. The proportion of the phospholipids synthesized changed only little with hardening, with a trend towards an increase in phosphatidylcholine. Increased phospholipid synthesis does not seem to be a prerequisite to hardening in winter wheat. However, a high rate of phospholipid synthesis may be required to maintain frost resistance. PMID:16659082

  4. Nowcasting of meteorological risks during the winter season using the "Integrated Meteorological Observation Network in Castilla y León, (Spain)"

    NASA Astrophysics Data System (ADS)

    Guerrero-Higueras, Ángel Manuel; López, Laura; Merino, Andrés; Sánchez, José Luis; Matía, Pedro; Lorente, José Manuel; Hermida, Lucía; Nafría, David; Ortiz de Galisteo, José Pablo; Marcos, José Luis; García-Ortega, Eduardo

    2013-04-01

    The location of Castilla y León within the Iberian Peninsula and its territorial extension make its meteorological risks diverse. The integration of various observation networks, both public and private, in the Observation Network of Castilla y León, allows us to follow the risks in real-time. One of the most frequent risks in the winter season is snow precipitation. In the present paper, we compared WRF numerical model predictions of snowfall for Castilla y León with data from the meteorological observation network and observations from the MSG satellite. Furthermore, frosts were more frequent in the area, to the point that there are parts of the study area with frost during the entire year. Thus, the data from the network allows us to determine the area where frost was registered. Finally, the situations with fog, especially with advective and radiative characteristics, are frequent in the center and south of the plateau, especially in the winter season. Additionally, the Observation Network allows us to know the areas with fog in real-time. The Observation Network is managed using a new platform, developed by Group for Atmospheric Physics, known as MeteoNet, which allows for the prompt extraction of a concrete parameter in a specific location, or, the spatial representation of a parameter determined for the entire study area. Furthermore, the management system developed for the data allows for the total representation of data from the WRF prediction model, with satellite images, observation network, radar data, etc., which is converted into a very useful tool for following risks and validating algorithms in Castilla y León. Acknowledgements The authors would like to thank the Regional Government of Castilla y León for its financial support through the project LE220A11-2.

  5. Impacts of extreme winter warming events on plant physiology in a sub-Arctic heath community.

    PubMed

    Bokhorst, Stef; Bjerke, Jarle W; Davey, Matthew P; Taulavuori, Kari; Taulavuori, Erja; Laine, Kari; Callaghan, Terry V; Phoenix, Gareth K

    2010-10-01

    Insulation provided by snow cover and tolerance of freezing by physiological acclimation allows Arctic plants to survive cold winter temperatures. However, both the protection mechanisms may be lost with winter climate change, especially during extreme winter warming events where loss of snow cover from snow melt results in exposure of plants to warm temperatures and then returning extreme cold in the absence of insulating snow. These events cause considerable damage to Arctic plants, but physiological responses behind such damage remain unknown. Here, we report simulations of extreme winter warming events using infrared heating lamps and soil warming cables in a sub-Arctic heathland. During these events, we measured maximum quantum yield of photosystem II (PSII), photosynthesis, respiration, bud swelling and associated bud carbohydrate changes and lipid peroxidation to identify physiological responses during and after the winter warming events in three dwarf shrub species: Empetrum hermaphroditum, Vaccinium vitis-idaea and Vaccinium myrtillus. Winter warming increased maximum quantum yield of PSII, and photosynthesis was initiated for E. hermaphroditum and V. vitis-idaea. Bud swelling, bud carbohydrate decreases and lipid peroxidation were largest for E. hermaphroditum, whereas V. myrtillus and V. vitis-idaea showed no or less strong responses. Increased physiological activity and bud swelling suggest that sub-Arctic plants can initiate spring-like development in response to a short winter warming event. Lipid peroxidation suggests that plants experience increased winter stress. The observed differences between species in physiological responses are broadly consistent with interspecific differences in damage seen in previous studies, with E. hermaphroditum and V. myrtillus tending to be most sensitive. This suggests that initiation of spring-like development may be a major driver in the damage caused by winter warming events that are predicted to become more frequent in some regions of the Arctic and that may ultimately drive plant community shifts. PMID:20497369

  6. Periphyton dynamics in a subalpine mountain stream during winter

    USGS Publications Warehouse

    Gustina, G.W.; Hoffmann, J.P.

    2000-01-01

    We conducted two experiments to determine the activity of and factors which control periphyton during winter in Stevensville Brook, Vermont. The first experiment during winter/spring 1994 examined the effect of a 300 to 450% difference in light and doubling of flow (low and high light, slow and fast flow) on periphyton chlorophyll a (chl a) and ash-free dry mass (AFDM) from stream rocks and artificial substrata. A second experiment was performed to determine whether periphyton was nitrogen or phosphorus limited. In addition, stream water was sampled during fall/winter 1994/95 for nitrate (NO3), ammonia (NH4), soluble reactive phosphorus (SRP), and total phosphorus (TP) to determine the availability of nutrients in Stevensville Brook. Increases of up to 250% for AFDM and 600% for chl a during the first study indicated robust activity throughout the winter despite low temperatures and light. Flow had a negative effect and sampling date was found to have a significant effect on periphyton biomass (chl a and AFDM) while light was found to influence increases in AFDM on clay tiles only. Water analyses showed that SRP was less than 0.001 mg L-1, NH4 and TP were low and often undetectable, and NO3 remained at about 0.20 mg L-1. Results from the nutrient enrichment experiment showed a significant response of chl a to P but not N and no response of AFDM to enrichment with either N or P. In Stevensville Brook during winter, the algal community, as represented by the chl a concentration, is predominantly controlled by phosphorus concentrations and is influenced to a lesser extent by flow; the periphyton community as a whole, represented by AFDM, is controlled mostly by stream flow and light.

  7. Development of a model system to identify differences in spring and winter oat.

    PubMed

    Chawade, Aakash; Lindén, Pernilla; Bräutigam, Marcus; Jonsson, Rickard; Jonsson, Anders; Moritz, Thomas; Olsson, Olof

    2012-01-01

    Our long-term goal is to develop a Swedish winter oat (Avena sativa). To identify molecular differences that correlate with winter hardiness, a winter oat model comprising of both non-hardy spring lines and winter hardy lines is needed. To achieve this, we selected 294 oat breeding lines, originating from various Russian, German, and American winter oat breeding programs and tested them in the field in south- and western Sweden. By assaying for winter survival and agricultural properties during four consecutive seasons, we identified 14 breeding lines of different origins that not only survived the winter but also were agronomically better than the rest. Laboratory tests including electrolytic leakage, controlled crown freezing assay, expression analysis of the AsVrn1 gene and monitoring of flowering time suggested that the American lines had the highest freezing tolerance, although the German lines performed better in the field. Finally, six lines constituting the two most freezing tolerant lines, two intermediate lines and two spring cultivars were chosen to build a winter oat model system. Metabolic profiling of non-acclimated and cold acclimated leaf tissue samples isolated from the six selected lines revealed differential expression patterns of 245 metabolites including several sugars, amino acids, organic acids and 181 hitherto unknown metabolites. The expression patterns of 107 metabolites showed significant interactions with either a cultivar or a time-point. Further identification, characterisation and validation of these metabolites will lead to an increased understanding of the cold acclimation process in oats. Furthermore, by using the winter oat model system, differential sequencing of crown mRNA populations would lead to identification of various biomarkers to facilitate winter oat breeding. PMID:22253782

  8. Mercury in wintering seabirds, an aggravating factor to winter wrecks?

    PubMed

    Fort, Jérôme; Lacoue-Labarthe, Thomas; Nguyen, Hanh Linh; Boué, Amélie; Spitz, Jérôme; Bustamante, Paco

    2015-09-15

    Every year, thousands of seabirds are cast ashore and are found dead along the coasts of North America and Western Europe. These massive mortality events called 'winter wrecks' have generally been attributed to harsh climatic conditions and prolonged storms which affect bird energy balance and impact their body condition. Nevertheless, additional stress factors, such as contaminant body burden, could potentially cumulate to energy constraints and actively contribute to winter wrecks. However, the role played by these additional factors in seabird massive winter mortality has received little attention to date. In February/March 2014, an unprecedented seabird wreck occurred along the Atlantic French coasts during which >43,000 seabirds were found dead. By analyzing mercury (Hg) concentrations in various tissues collected on stranded birds, we tested the hypothesis that Hg played a significant role in this mortality. More specifically, we aimed to (1) describe Hg contamination in wintering seabirds found along the French coasts in 2014, and (2) determine if Hg concentrations measured in some vital organs such as kidney and brain reached toxicity thresholds that could have led to deleterious effects and to an enhanced mortality. We found some of the highest Hg levels ever reported in Atlantic puffins, common guillemots, razorbills and kittiwakes. Measured concentrations ranged from 0.8 to 3.6?g·g(-1) of dry weight in brain, 1.3 to 7.2?g·g(-1) in muscle, 2.5 to 13.5?g·g(-1) in kidney, 2.9 to 18.6?g·g(-1) in blood and from 3.1 to 19.5?g·g(-1) in liver. Hg concentrations in liver and brain were generally below the estimated acute toxicity levels. However, kidney concentrations were not different than those measured in the liver, and above levels associated to renal sub-lethal effects, suggesting a potential Hg poisoning. We concluded that although Hg was not directly responsible for the high observed mortality, it has been a major aggravating stress factor for emaciated birds already on the edge. Importantly, this study also demonstrated that total blood, which can be non-lethally collected in seabirds, can be used as a predictor of Hg contamination in other tissues. PMID:25984703

  9. Mercury in breeding and wintering Nelson's Sparrows (Ammodramus nelsoni).

    PubMed

    Winder, V L; Emslie, S D

    2011-01-01

    The objective of this study was to increase our understanding of Hg exposure in birds with obligate ties to coastal salt marsh and inland wetland systems. Many species filling such niches are of conservation concern because of reduced size and quality of vital habitats. We used Nelson's Sparrow (Ammodramus nelsoni) as an indicator of regional mercury (Hg) availability in its breeding and wintering salt marsh and wetland habitats. Blood, breast feathers and the first primary feather were sampled from Nelson's Sparrows wintering in North Carolina coastal salt marshes and breeding in wetland systems in North Dakota (A. n. nelsoni) and Ontario, Canada (A. n. alterus). Wintering Nelson's Sparrow breast feathers contained 3.0 times as much Hg as birds breeding in North Dakota and 2.4 times as much Hg as those breeding in Ontario. Breeding Nelson's Sparrows in North Dakota exhibited blood Hg levels 4.9 times as high as those from birds breeding along James Bay and 7.6 times as high as those wintering in North Carolina. These results provide significant insight on the timing of molt in this species as well as how Hg exposure varies regionally and seasonally for these birds. Further, our results provide a better understanding of how and where Hg exposure may be a threat to Nelson's Sparrows and other birds with obligate ties to aquatic systems. PMID:21082242

  10. Contrasts between symptoms of summer depression and winter depression.

    PubMed

    Wehr, T A; Giesen, H A; Schulz, P M; Anderson, J L; Joseph-Vanderpool, J R; Kelly, K; Kasper, S; Rosenthal, N E

    1991-12-01

    Epidemiological studies and studies of clinical populations suggest that there are primarily two opposite patterns of seasonally recurring depressions: summer depression and winter depression. In addition, there is preliminary evidence that the two seasonal types of depression may have opposite types of vegetative symptoms. In the present study, we prospectively monitored symptoms of depression in 30 patients with recurrent summer depression and 30 sex-matched patients with recurrent winter depression and compared the symptom profiles of the two groups. Consistent with predictions based on the earlier reports, we found that winter depressives were more likely to have atypical vegetative symptoms, with increased appetite, carbohydrate craving, weight gain and hypersomnia, and that summer depressives were more likely to have endogenous vegetative symptoms, with decreased appetite and insomnia. A cluster analysis performed on the patients' symptom profiles without reference to season of occurrence of their episodes separated 78% of the summer depressives and winter depressives from each other on the basis of their symptoms (chi 2 = 19.29, P less than 0.001). PMID:1791262

  11. a Climatology of Extreme Minimum Winter Temperatures in Ohio

    NASA Astrophysics Data System (ADS)

    Edgell, Dennis Joe

    The Extreme Minimum Winter Temperature (EMWT) is the coldest temperature recorded each winter at a given weather station. This variable is a measure of winter temperature stress. Extreme cold influences the geographic distribution of plants, and is a prime control for the production of some valuable fruit crops grown in Ohio. EMWT values are often used to map plant hardiness zones, however the magnitude of EMWT and the date that it occurs has varied widely from year to year. Climatic variables rarely remain constant over time, and the plant hardiness zones could shift significantly if the climate changes and there is a trend towards warmer EMWTs. Plants that have their present geographic ranges limited by cold winter temperatures could increase their spatial extent. Furthermore, EMWT has impacts on human health and has applications for architecture. EMWTs at eighty-nine weather stations in Ohio were analyzed. Summary statistics and return period intervals for critical EMWTs are tabulated and mapped. Return period maps may be more useful for environmental planning than plant hardiness zone maps based on average EMWT, especially in a variable climate. Graphical methods, curve fitting and a probability model for the mean were utilized to examine the long term trend. The EMWT has not warmed during the known climatic record of this variable in Ohio. This study demonstrates the need for more applied climatological studies based on the observed climate record, not obscured by the assumptions of the global warming paradigm.

  12. Changes in winter warming events in the Nordic Arctic Region

    NASA Astrophysics Data System (ADS)

    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 pattern with a strong increase in warm spells for the next 50 years.

  13. Soil aggregates and their associated carbon and nitrogen content in winter annual pastures using different tillage management options

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Traditionally, winter annual pastures are established on grazing areas that are steeply sloping and not regarded as suitable for row-crop production. Using conventional (CT) tillage methods to prepare these fragile lands for winter annual pastures leads to increased erosion and rapid soil degradatio...

  14. Impact of elevated temperature on the growth, survival, and trophic dynamics of winter flounder larvae: a mesocosm study

    Microsoft Academic Search

    Aimee A. Keller; Grace Klein-MacPhee

    2000-01-01

    Winter flounder (Pseudopleuronectes americanus ) is a dominant commercial fish in Narragansett Bay, Rhode Island, and yet factors controlling its recruitment remain unclear. An experiment was conducted with six 13-m 3 land- based mesocosms (5 m deep) from February to April 1997 to address the impact of increased temperature (+3°C) on growth, survival, and trophic dynamics of winter flounder larvae.

  15. Cadmium in Soil and Winter Wheat Grain in Southern Sweden: I. Factors Influencing Cd Levels in Soils and Grain

    Microsoft Academic Search

    Jan. E. Eriksson; Mats Söderström

    1996-01-01

    The guideline level for Cd contents in cereals of 100 ?g kg proposed by the Codex Committee on Cereals, Pulses and Legumes has increased concern regarding Cd levels in Swedish winter wheat. In this study, Cd levels in soil and grain and factors influencing these variables were investigated in Skåne, the southernmost province in Sweden. In 1992, soils and winter

  16. Winter WeatherWinter WeatherWinter WeatherWinter Weather Tips to prepare your carTips to prepare your carTips to prepare your carTips to prepare your car

    E-print Network

    Queitsch, Christine

    Winter WeatherWinter WeatherWinter WeatherWinter Weather Tips to prepare your carTips to prepare your carTips to prepare your carTips to prepare your car for winterfor winterfor winterfor winter Charge it. Cold weather is tough on batteries. At zero degrees, a car's battery loses about 60 percent

  17. An analysis of US propane markets, winter 1996-1997

    SciTech Connect

    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.

  18. Vol. 4, No. 1 Winter 200506Vol. 4, No. 1 Winter 200506 Informatics

    E-print Network

    Zhou, Yaoqi

    Vol. 4, No. 1 · Winter 2005­06Vol. 4, No. 1 · Winter 2005­06 LEAD Informatics Researchers Take the in Hurricane Prediction LEAD Informatics Researchers Take the in Hurricane Prediction #12;Vol. 4, No. 1 WINTER with the School of Informatics, and is mailed to all alumni of the School of Informatics. For information about

  19. Partial Support for Winter Wheat Laboratory Marker-Assisted-Selection Program Phil Bruckner, Winter Wheat Breeder

    E-print Network

    Maxwell, Bruce D.

    Partial Support for Winter Wheat Laboratory Marker-Assisted-Selection Program Phil Bruckner, Winter Wheat Breeder Project Description Marker-assisted selection (MAS) is an established plant breeding with limited technological capabilities such as ours. The MSU winter wheat program conducted a laboratory MAS

  20. Multistate proteomics analysis reveals novel strategies used by a hibernator to precondition the heart and conserve ATP for winter heterothermy.

    PubMed

    Grabek, Katharine R; Karimpour-Fard, Anis; Epperson, L Elaine; Hindle, Allyson; Hunter, Lawrence E; Martin, Sandra L

    2011-11-21

    The hibernator's heart functions continuously and avoids damage across the wide temperature range of winter heterothermy. To define the molecular basis of this phenotype, we quantified proteomic changes in the 13-lined ground squirrel heart among eight distinct physiological states encompassing the hibernator's year. Unsupervised clustering revealed a prominent seasonal separation between the summer homeotherms and winter heterotherms, whereas within-season state separation was limited. Further, animals torpid in the fall were intermediate to summer and winter, consistent with the transitional nature of this phase. A seasonal analysis revealed that the relative abundances of protein spots were mainly winter-increased. The winter-elevated proteins were involved in fatty acid catabolism and protein folding, whereas the winter-depleted proteins included those that degrade branched-chain amino acids. To identify further state-dependent changes, protein spots were re-evaluated with respect to specific physiological state, confirming the predominance of seasonal differences. Additionally, chaperone and heat shock proteins increased in winter, including HSPA4, HSPB6, and HSP90AB1, which have known roles in protecting against ischemia-reperfusion injury and apoptosis. The most significant and greatest fold change observed was a disappearance of phospho-cofilin 2 at low body temperature, likely a strategy to preserve ATP. The robust summer-to-winter seasonal proteomic shift implies that a winter-protected state is orchestrated before prolonged torpor ensues. Additionally, the general preservation of the proteome during winter hibernation and an increase of stress response proteins, together with dephosphorylation of cofilin 2, highlight the importance of ATP-conserving mechanisms for winter cardioprotection. PMID:21914784

  1. Use of urease inhibitors and urea fertilizers on winter wheat

    Microsoft Academic Search

    AJ Schlegel; DW Nelson; LE Sommers

    1987-01-01

    Phosphoroamide urease inhibitors were evaluated for their ability to increase grain protein and yield of winter wheat (Triticum aestivum L.) when added to surfaceapplied urea-based fertilizers. Six urease inhibitors [trichloroethyl phosphorodiamidate, diethyl phosphoric triamide, dimethyl phosphoric triamide, N-(diaminophosphinyl)-cyclohexylamine, N-benzyl-N-methyl phosphoric triamide, and phenylphosphorodiamide] were evaluated. Nitrogen treatments were urea prills, urea solution, and ureaammonium nitrate (UAN) solution broadcast and UAN

  2. Vitamin D3 enhances mood in healthy subjects during winter

    Microsoft Academic Search

    Allen T. G. Lansdowne; S. C. Provost

    1998-01-01

    Mood changes synchronised to the seasons exist on a continuum between individuals, with anxiety and depression increasing\\u000a during the winter months. An extreme form of seasonality is manifested as the clinical syndrome of seasonal affective disorder\\u000a (SAD) with carbohydrate craving, hypersomnia, lethargy, and changes in circadian rhythms also evident. It has been suggested\\u000a that seasonality and the symptoms of SAD

  3. Selenium Accumulation in Sea Ducks Wintering at Lake Ontario

    Microsoft Academic Search

    Michael L. Schummer; Shannon S. Badzinski; Scott A. Petrie; Yu-Wei Chen; Nelson Belzile

    2010-01-01

    Numbers of wintering sea ducks, including buffleheads (Bucephala albeola; BUFF), common goldeneyes (Bucephala clangula; COGO), and long-tailed ducks (Clangula hyemalis; LTDU), increased substantially at Lake Ontario after Dreissenid mussels (Dreissena bugensis and D. polymorpha) colonized the Great Lakes. Invertebrates, including Dreissenid mussels, are major diving duck prey items that can transfer\\u000a some trace elements, such as selenium (Se) to higher

  4. In situ measurements of midlatitude ClO in winter

    Microsoft Academic Search

    D. W. Toohey; J. G. Anderson; W. H. Brune; K. R. Chan

    1991-01-01

    In situ measurements of ClO in the winter lower stratosphere are presented for six flights of the NASA ER-2 aircraft from 38°N to 61°N. Enhanced abundances, increasing in severity with data, were observed below 20 km, where HCl and ClONOâ dominate the inorganic chlorine budget. The greatest mixing ratios, over 150 pptv, were encountered on February 20 and 21, 1989,

  5. Recovery of photosynthetic capacity in Vaccinium vitis - idaea during mild spells in winter

    Microsoft Academic Search

    Timo Saarinen; Robin Lundell; Heikki Hänninen

    Recent studies suggest that evergreen plants may maintain their photosynthetic capacity through the winter. Since mild winters\\u000a are predicted to be more frequent in the future, the metabolic activity of plants is also likely to increase. The aim of the\\u000a present study was to assess how various environmental factors, such as temperature, photoperiod and preceding frost, affect\\u000a the recovery of

  6. Trade-off between immune response and body mass in wintering house sparrows ( Passer domesticus )

    Microsoft Academic Search

    Gregorio Moreno-Rueda

    Immunity is necessary in order to fight parasites and pathogens, but immune protection also incurs a cost for the hosts. Therefore,\\u000a immunity should be traded against other fitness-related traits. Body mass, as a function of body reserves, is important in\\u000a birds of temperate zones during winter. Sedentary temperate birds usually increase body mass just before winter to survive\\u000a a period

  7. Does diurnal variation in body mass affect take-off ability in wintering willow tits?

    Microsoft Academic Search

    CECILIA KULLBERG

    1998-01-01

    Recently, some empirical studies have shown an effect of body mass on take-off ability in birds, supporting the theory that birds with increased fat loads face a greater predation risk. Small wintering birds accumulate fat reserves of about 10% of their fat-free body mass during the day to survive long, cold, winter nights. Theoretically, mass-dependent predation risk could be an

  8. The winter Arctic Oscillation, the timing of spring, and carbon fluxes in the Northern Hemisphere

    Microsoft Academic Search

    Kevin Schaefer; A. Scott Denning; Owen Leonard

    2005-01-01

    Various observations show trends toward warmer and earlier springs in the Northern Hemisphere. We hypothesize that the positive trend in the winter Arctic Oscillation (AO) has led to higher winter temperatures, advanced spring, and increased seasonal amplitudes in atmospheric CO2. To test this hypothesis, we modeled leaf-out and terrestrial carbon fluxes using the Simple Biosphere model, Version 2 (SiB2) and

  9. Are summit metabolism and thermogenic endurance correlated in winter-acclimatized passerine birds?

    Microsoft Academic Search

    David L. Swanson

    2001-01-01

    Small birds exhibiting marked winter improvement of cold tolerance also show elevated summit metabolic rates (maximum cold-induced metabolic rate) in winter relative to summer. However, relatively large increases in cold tolerance can occur with only minor increments of maximum cold-induced metabolic rate and geographic variation in cold tolerance is not always positively correlated with variation in maximum cold-induced metabolic rate.

  10. Dissolved oxygen in the Tualatin River, Oregon, during winter flow conditions, 1991 and 1992

    USGS Publications Warehouse

    Kelly, V.J.

    1996-01-01

    Throughout the winter period, November through April, wastewater treatment plants in the Tualatin River Basin discharge from 10,000 to 15,000 pounds per day of biochemical oxygen demand to the river. These loads often increase substantially during storms when streamflow is high. During the early winter season, when streamflow is frequently less than the average winter flow, the treatment plants discharge about 2,000 pounds per day of ammonia. This study focused on the capacity of the Tualatin River to assimilat oxygen-demanding loads under winter streamflow conditions during the 1992 water year, with an emphasis on peak-flow conditions in the river, and winter-base-flow conditions during November 1992. Concentrations of dissolved oxygen throughout the main stem of the river during the winter remained generally high relative to the State standard for Oregon of 6 milligrams per liter. The most important factors controlling oxygen consumption during winter-low-flow conditions were carbonaceous biochemical oxygen demand and input of oxygen-depleted waters from tributaries. During peak-flow conditions, reduced travel time and increased dilution associated with the increased streamflow minimized the effect of increased oxygen-demanding loads. During the base-flow period in November 1992, concentrations of dissolved oxygen were consistently below 6 milligrams per liter. A hydrodynamic water-quality model was used to identify the processes depleting dissolved oxygen, including sediment oxygen demand, nitrification, and carbonaceous biochemical oxygen demand. Sediment oxygen demand was the most significant factor; nitrification was also important. Hypothetical scenarios were posed to evaluate the effect of different wastewater treatment plant loads during winter-base-flow conditions. Streamflow and temperature were significant factors governing concentrations of dissolved oxygen in the main-stem river.

  11. Herbivory on shoalgrass by wintering redheads in Texas

    USGS Publications Warehouse

    Mitchell, C.A.; Custer, T.W.; Zwank, P.J.

    1994-01-01

    An estimated 80% of redheads (Aythya americana) winter on the Laguna Madre of south Texas and Mexico and feed almost exclusively on shoalgrass (Halodule wrightii) rhizomes. Shoalgrass abundance has decreased by 60% over the past 30 years, and because the effects of shoalgrass loss on wintering redheads are unknown, we initiated a study to define habitat selection criteria and document the effect of wintering redheads on shoalgrass in the lower Laguna Madre, Texas. Redheads consumed an average of 75% of shoalgrass rhizome biomass at collection sites each winter. When rhizome biomass was grazed to a mean biomass of ltoreq 0.18 g dry mass/core (approximately 10 g dry mass/ml), shoalgrass did not recover to its previous level the following growing season. Thirty-three percent of the sites (10) were grazed below 0.18 g dry mass/core during both years of the study, while 64% (19) were grazed below 0.18 g during 1 or the other of the 2 winters. Ramet number was positively correlated (P lt 0.001, r-2 = 0.54) with rhizome biomass; however, this relationship was influenced by grazing intensity. Heavy grazing reduced the amount of rhizome attached to each ramet compared with ungrazed ramets. Grazing had no effect on root biomass (P = 0.388), rhizome moisture content (P = 0.553), or soil magnesium, phosphorous, and potassium (P = 0.102, 0.499, 0.162, respectively). Redhead presence increased (P = 0.042) soil nitrogen levels. Foraging areas selected by redheads within the lower Laguna Madre had lower (P = 0.026) salinities (24 ppt) than areas not selected (35 ppt). Redheads did not select foraging areas in relation to crude protein levels in rhizomes. Shoalgrass habitat in the Laguna Madre should be protected from further losses and enhanced where possible.

  12. Selenium accumulation in sea ducks wintering at Lake Ontario.

    PubMed

    Schummer, Michael L; Badzinski, Shannon S; Petrie, Scott A; Chen, Yu-Wei; Belzile, Nelson

    2010-04-01

    Numbers of wintering sea ducks, including buffleheads (Bucephala albeola; BUFF), common goldeneyes (Bucephala clangula; COGO), and long-tailed ducks (Clangula hyemalis; LTDU), increased substantially at Lake Ontario after Dreissenid mussels (Dreissena bugensis and D. polymorpha) colonized the Great Lakes. Invertebrates, including Dreissenid mussels, are major diving duck prey items that can transfer some trace elements, such as selenium (Se) to higher trophic levels. Se can be problematic for waterfowl and it often has been detected at elevated levels in organisms using the Great Lakes. There are, however, few data on hepatic Se concentrations in sea ducks, particularly during the winter at Lake Ontario. In this study, we evaluated interspecific differences and temporal trends in hepatic Se concentrations among BUFF (n = 77), COGO (n = 77), and LTDU (n = 79) wintering at Lake Ontario. All three species accumulated Se throughout winter, but COGO did so at a higher rate than did BUFF and LTDU. Overall, Se concentrations were higher in LTDU [mean = 22.7; 95% CI = 20.8-24.8 microg/g dry weight (dw)] than in BUFF ([mean = 12.3; 95% CI = 11.6-13.1 microg/g dw) and COGO ([mean = 12.0; 95% CI = 10.7-3.5 microg/g dw) throughout the winter. Se concentrations were deemed elevated (>33 microg/g dw) in 0%, 5%, and 19% of BUFF, COGO, and LTDU, respectively. Presently there are no data on Se toxicity end points for these species, so it is unclear how acquiring concentrations of these magnitudes affect their short- and long-term health or reproduction. PMID:19653029

  13. Responses of the photosynthetic apparatus to winter conditions in broadleaved evergreen trees growing in warm temperate regions of Japan.

    PubMed

    Tanaka, Chizuru; Nakano, Takashi; Yamazaki, Jun-Ya; Maruta, Emiko

    2015-01-01

    Photosynthetic characteristics of two broadleaved evergreen trees, Quercus myrsinaefolia and Machilus thunbergii, were compared in autumn and winter. The irradiance was similar in both seasons, but the air temperature was lower in winter. Under the winter conditions, net photosynthesis under natural sunlight (Anet) in both species dropped to 4 ?mol CO2 m(-2) s(-1), and the quantum yield of photosystem II (PSII) photochemistry in dark-adapted leaves (Fv/Fm) also dropped to 0.60. In both species the maximum carboxylation rates of Rubisco (V(cmax)) decreased, and the amount of Rubisco increased in winter. A decline in chlorophyll (Chl) concentration and an increase in the Chl a/b ratio in winter resulted in a reduction in the size of the light-harvesting antennae. From measurements of Chl a fluorescence parameters, both the relative fraction and the energy flux rates of thermal dissipation through other non-photochemical processes were markedly elevated in winter. The results indicate that the photosynthetic apparatus in broadleaved evergreen species in warm temperate regions responds to winter through regulatory mechanisms involving the downregulation of light-harvesting and photosynthesis coupled with increased photoprotective thermal energy dissipation to minimize photodamage in winter. These mechanisms aid a quick restart of photosynthesis without the development of new leaves in the following spring. PMID:25500451

  14. Winter climate change effects on soil C and N cycles in urban grasslands.

    PubMed

    Durán, Jorge; Rodríguez, Alexandra; Morse, Jennifer L; Groffman, Peter M

    2013-09-01

    Despite growing recognition of the role that cities have in global biogeochemical cycles, urban systems are among the least understood of all ecosystems. Urban grasslands are expanding rapidly along with urbanization, which is expected to increase at unprecedented rates in upcoming decades. The large and increasing area of urban grasslands and their impact on water and air quality justify the need for a better understanding of their biogeochemical cycles. There is also great uncertainty about the effect that climate change, especially changes in winter snow cover, will have on nutrient cycles in urban grasslands. We aimed to evaluate how reduced snow accumulation directly affects winter soil frost dynamics, and indirectly greenhouse gas fluxes and the processing of carbon (C) and nitrogen (N) during the subsequent growing season in northern urban grasslands. Both artificial and natural snow reduction increased winter soil frost, affecting winter microbial C and N processing, accelerating C and N cycles and increasing soil : atmosphere greenhouse gas exchange during the subsequent growing season. With lower snow accumulations that are predicted with climate change, we found decreases in N retention in these ecosystems, and increases in N2 O and CO2 flux to the atmosphere, significantly increasing the global warming potential of urban grasslands. Our results suggest that the environmental impacts of these rapidly expanding ecosystems are likely to increase as climate change brings milder winters and more extensive soil frost. PMID:23630015

  15. El Niño-Southern Oscillation Impacts on Winter Vegetable Production in Florida*.

    NASA Astrophysics Data System (ADS)

    Hansen, James W.; Jones, James W.; Kiker, Clyde F.; Hodges, Alan W.

    1999-01-01

    Florida's mild winters allow the state to play a vital role in supplying fresh vegetables for U.S. consumers. Producers also benefit from premium prices when low temperatures prevent production in most of the country. This study characterizes the influence of the El Niño-Southern Oscillation (ENSO) on the Florida vegetable industry using statistical analysis of the response of historical crop (yield, prices, production, and value) and weather variables (freeze hazard, temperatures, rainfall, and solar radiation) to ENSO phase and its interaction with location and time of year. Annual mean yields showed little evidence of response to ENSO phase and its interaction with location. ENSO phase and season interacted to influence quarterly yields, prices, production, and value. Yields (tomato, bell pepper, sweet corn, and snap bean) were lower and prices (bell pepper and snap bean) were higher in El Niño than in neutral or La Niña winters. Production and value of tomatoes were higher in La Niña winters. The yield response can be explained by increased rainfall, reduced daily maximum temperatures, and reduced solar radiation in El Niño winters. Yield and production of winter vegetables appeared to be less responsive to ENSO phase after 1980; for tomato and bell pepper, this may be due to improvements in production technology that mitigate problems associated with excess rainfall. Winter yield and price responses to El Niño events have important implications for both producers and consumers of winter vegetables, and suggest opportunities for further research.

  16. A metagenomic assessment of winter and summer bacterioplankton from Antarctica Peninsula coastal surface waters.

    PubMed

    Grzymski, Joseph J; Riesenfeld, Christian S; Williams, Timothy J; Dussaq, Alex M; Ducklow, Hugh; Erickson, Matthew; Cavicchioli, Ricardo; Murray, Alison E

    2012-10-01

    Antarctic surface oceans are well-studied during summer when irradiance levels are high, sea ice is melting and primary productivity is at a maximum. Coincident with this timing, the bacterioplankton respond with significant increases in secondary productivity. Little is known about bacterioplankton in winter when darkness and sea-ice cover inhibit photoautotrophic primary production. We report here an environmental genomic and small subunit ribosomal RNA (SSU rRNA) analysis of winter and summer Antarctic Peninsula coastal seawater bacterioplankton. Intense inter-seasonal differences were reflected through shifts in community composition and functional capacities encoded in winter and summer environmental genomes with significantly higher phylogenetic and functional diversity in winter. In general, inferred metabolisms of summer bacterioplankton were characterized by chemoheterotrophy, photoheterotrophy and aerobic anoxygenic photosynthesis while the winter community included the capacity for bacterial and archaeal chemolithoautotrophy. Chemolithoautotrophic pathways were dominant in winter and were similar to those recently reported in global 'dark ocean' mesopelagic waters. If chemolithoautotrophy is widespread in the Southern Ocean in winter, this process may be a previously unaccounted carbon sink and may help account for the unexplained anomalies in surface inorganic nitrogen content. PMID:22534611

  17. A SIMPLE WINTER PROTECTION SYSTEM FOR BLACKBERRIES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little commercial blackberry production exists in areas with severe winters (minimum winter temperatures below ­18 degrees C and short growing seasons. In this study, we evaluated the combination of simple cultural practices, a modified rotatable cross-arm (RCA) trellis system, and covering plants ...

  18. A SIMPLE WINTER PROTECTION SYSTEM FOR BLACKBERRIES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little commercial blackberry production exists in areas with severe winters (minimum winter temperatures below -12 degrees C and short growing seasons. In this study, we evaluated the combination of simple cultural practices, a modified rotatable cross-arm (RCA) trellis system, and covering plants w...

  19. Winter huddling groups in the striped mouse

    Microsoft Academic Search

    C. Schradin; M. Schubert; N. Pillay

    2006-01-01

    Huddling is a strategy to avoid heat loss and thus save energy and is often observed in birds and rodents, which, because of their small body size, are prone to relatively high heat loss. Huddling might thus explain group-living in some cases, such as the winter huddling groups described for several northern hemisphere rodents. Here we describe winter hud- dling

  20. CMPUT 631 Winter 2013 Robotics: Visual Navigation

    E-print Network

    Zhang, Hong

    Navigation: State-of-the-Art · DARPA Grand Challenge 2004/2005 · DARPA Urban Challenge (2008) · Cummins: "Robots that fly" (GRASP Lab, 2011) · Big dog and Petman (Boston Dynamics, 2008, 2010) · DARPA Robotics sets ­Credit for creativity CMPUT 631 Winter 2013 CMPUT 631 Winter 2013 DARPA Grand Challenge 2004

  1. Vegetables and grass winter covers in rotation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rotation of different crops may allow for extended usage of crop land. The early maturing ryegrass (Lolium multiflorum Lam.), cv. Shiwasuaoba, and the later maturing cv. Gulf, were planted as over-wintering covers. Controls consisted of a fall planted winter wheat cultivar and bare soil. The fol...

  2. Disturbance to wintering western snowy plovers

    Microsoft Academic Search

    Kevin D. Lafferty

    2001-01-01

    In order to better understand the nature of disturbances to wintering snowy plovers, I observed snowy plovers and activities that might disturb them at a beach near Devereux Slough in Santa Barbara, California, USA. Disturbance (activity that caused plovers to move or fly) to wintering populations of threatened western snowy plovers was 16 times higher at a public beach than

  3. Endothermic heat production in honeybee winter clusters.

    PubMed

    Stabentheiner, Anton; Pressl, Helga; Papst, Thomas; Hrassnigg, Norbert; Crailsheim, Karl

    2003-01-01

    In order to survive cold northern winters, honeybees crowd tightly together in a winter cluster. Present models of winter cluster thermoregulation consider the insulation by the tightly packed mantle bees as the decisive factor for survival at low temperatures, mostly ignoring the possibility of endothermic heat production. We provide here direct evidence of endothermic heat production by 'shivering' thermogenesis. The abundance of endothermic bees is highest in the core and decreases towards the surface. This shows that core bees play an active role in thermal control of winter clusters. We conclude that regulation of both the insulation by the mantle bees and endothermic heat production by the inner bees is necessary to achieve thermal stability in a winter cluster. PMID:12477904

  4. Short winters threaten temperate fish populations.

    PubMed

    Farmer, Troy M; Marschall, Elizabeth A; Dabrowski, Konrad; Ludsin, Stuart A

    2015-01-01

    Although climate warming is expected to benefit temperate ectotherms by lengthening the summer growing season, declines in reproductive success following short, warm winters may counter such positive effects. Here we present long-term (1973-2010) field patterns for Lake Erie yellow perch, Perca flavescens, which show that failed annual recruitment events followed short, warm winters. Subsequent laboratory experimentation and field investigations revealed how reduced reproductive success following short, warm winters underlie these observed field patterns. Following short winters, females spawn at warmer temperatures and produce smaller eggs that both hatch at lower rates and produce smaller larvae than females exposed to long winters. Our research suggests that continued climate warming can lead to unanticipated, negative effects on temperate fish populations. PMID:26173734

  5. Impact of the winter North Atlantic Oscillation (NAO) on the Western Pacific (WP) pattern in the following winter through Arctic sea ice and ENSO

    NASA Astrophysics Data System (ADS)

    Tachibana, Yoshihiro; Oshika, Miki; Nakamura, Tetsu

    2015-04-01

    This study tested the hypothesis that Asian weather and climate in a given winter can be predicted 1 year in advance. On the basis of a 51-year statistical analysis of reanalysis data, we propose for the first time that the positive phase of the Western Pacific (WP) pattern in the winter is linked to the negative phase of the North Atlantic Oscillation (NAO) in the previous winter, and vice versa. We show that there are two possible mechanisms responsible for this interannual remote linkage. One is an Arctic mechanism. Extensive Arctic sea ice in the summer after a negative NAO acts as a bridge to the positive phase of the WP in the next winter. The negative (positive) phase of the winter NAO changes oceanic currents in the North Atlantic and weakens (strengthens) oceanic heat transport into the Arctic. This weakened (strengthened) heat transport also slows down (speeds up) the reduction of sea ice in the spring. A condition of more (less) ice than normal then persists until the season of ice freezing in autumn. In winter, all of the Arctic Ocean is covered by sea ice, regardless of the autumn ice area. Less (more) ice production during the freezing season reduces (increases) the heat released from the ocean to the atmosphere in the Arctic. An anomalously small (large) heat flux excites stationary Rossby wave propagation, which induces warm (cold) advection to Japan. The other mechanism involves the tropics. An El Niño occurrence after a negative winter NAO acts as another bridge to the positive phase of the WP in the following winter. The timescale of the Arctic route is nearly decadal, whereas that of the tropical route is about 3-5 years. The tropical mechanism indicates that the NAO remotely excites an El Niño in the second half of the following year. A process perhaps responsible for the El Niño occurrence was investigated statistically. A negative NAO in the winter increases Eurasian snow cover. This anomalous snow cover then intensifies the cold air outbreak from Asia to the western tropical Pacific. This outbreak can intensify the westerly wind burst and excite El Niño in the following year. We suggest that the phase of the NAO in the winter could be a predictor of the WP in the following year. Detailed is in Oshika, Tachibana and Nakamura in Climate Dynamics (2014), DOI: 10.1007/s00382-014-2384-1.

  6. Field investigations of winter transmission of eastern equine encephalitis virus in Florida.

    PubMed

    Bingham, Andrea M; Burkett-Cadena, Nathan D; Hassan, Hassan K; McClure, Christopher J W; Unnasch, Thomas R

    2014-10-01

    Studies investigating winter transmission of Eastern equine encephalitis virus (EEEV) were conducted in Hillsborough County, Florida. The virus was detected in Culiseta melanura and Anopheles quadrimaculatus in February 2012 and 2013, respectively. During the winter months, herons were the most important avian hosts for all mosquito species encountered. In collections carried out in the summer of 2011, blood meals taken from herons were still common, but less frequently encountered than in winter, with an increased frequency of mammalian- and reptile-derived meals observed in the summer. Four wading bird species (Black-crowned Night Heron [Nycticorax nycticorax], Yellow-crowned Night Heron [Nyctanassa violacea], Anhinga [Anhinga anhinga], and Great Blue Heron [Ardea herodias]) were most frequently fed upon by Cs. melanura and Culex erraticus, suggesting that these species may participate in maintaining EEEV during the winter in Florida. PMID:25070997

  7. Lesser scaup winter foraging and nutrient reserve acquisition in east-central Florida

    USGS Publications Warehouse

    Herring, G.; Collazo, J.A.

    2006-01-01

    Lesser scaup (Aythya affinis) populations have been declining since the late 1970s. One of the explanations to account for this decline, the spring-condition hypothesis (SCH), is based on the premise that scaup are limited by their ability to acquire or maintain nutrient reserves during migration to the breeding grounds, leading to an impairment of their reproductive potential. Available evidence suggests that endogenous reserves required for reproduction are obtained at a later stage of migration or after arrival at the breeding grounds, not wintering sites. However, only one study has addressed body-condition levels on a southern wintering site in the last decade, with results limited to the wintering grounds on the Mississippi Flyway. We documented foraging behavior, nutrient levels, and body mass of lesser scaup in east-central Florida, USA, where 62% of the Atlantic Flyway population overwinters, during the winters of 2002 and 2003. Diurnal foraging did not increase seasonally. Nocturnal foraging increased seasonally by 76% or 43 minutes per night in females and by 478% or 1.9 hours per night in males. Measures of body condition did not change seasonally during 2002 for either sex. Between early and later winter in 2003 corrected body mass (CBM) and lipid reserves of male scaup increased 77 g and 39 g, respectively. Our results suggest that lesser scaup maintain or may slightly improve their physiological condition in east-central Florida during winter. Lower body mass and differences in nutrient levels in east-central Florida, compared to a wintering site in Louisiana, likely stem from geographic variation and lower thermal requirements associated with the warmer Florida environment. Lesser scaup depart Florida with sufficient reserves to initiate spring migration, but they maximize nutrient reserves used during reproduction elsewhere during migration or on the breeding grounds. These results suggest that maintaining the ecological integrity of this wintering ground is critical in minimizing winter mortality and preventing it from becoming an ancillary factor in current declines. Future research should address understanding survival rates during spring migration and at critical staging areas to provide new insight into the ramifications of scaup leaving wintering habitats such as MINWR with lower body condition than at other wintering sites in other flyways.

  8. Increasing Knowledge Increasing Knowledge 29

    E-print Network

    Fay, Noah

    28 Increasing Knowledge Increasing Knowledge 29 Expanding Leadership 36 Building Partnerships 43 the world. The challenges ahead are large, but WSP is preparing to meet them by increasing knowledge, expanding leadership, building partnerships, and seeking solutions. #12;29 Increasing Knowledge Increasing

  9. Climate warming will not decrease winter mortality

    NASA Astrophysics Data System (ADS)

    Staddon, Philip L.; Montgomery, Hugh E.; Depledge, Michael H.

    2014-03-01

    It is widely assumed by policymakers and health professionals that the harmful health impacts of anthropogenic climate change will be partially offset by a decline in excess winter deaths (EWDs) in temperate countries, as winters warm. Recent UK government reports state that winter warming will decrease EWDs. Over the past few decades, however, the UK and other temperate countries have simultaneously experienced better housing, improved health care, higher incomes and greater awareness of the risks of cold. The link between winter temperatures and EWDs may therefore no longer be as strong as before. Here we report on the key drivers that underlie year-to-year variations in EWDs. We found that the association of year-to-year variation in EWDs with the number of cold days in winter ( <5 °C), evident until the mid 1970s, has disappeared, leaving only the incidence of influenza-like illnesses to explain any of the year-to-year variation in EWDs in the past decade. Although EWDs evidently do exist, winter cold severity no longer predicts the numbers affected. We conclude that no evidence exists that EWDs in England and Wales will fall if winters warm with climate change. These findings have important implications for climate change health adaptation policies.

  10. Variability of Winter Air Temperature in Mid-Latitude Europe

    NASA Technical Reports Server (NTRS)

    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 cover and precipitable water are from the National Centers for Environmental Prediction (NCEP) Reanalysis.

  11. Field Demonstration of Automated Demand Response for Both Winter and Summer Events in Large Buildings in the Pacific Northwest

    SciTech Connect

    Piette, Mary Ann; Kiliccote, Sila; Dudley, Junqiao H.

    2011-11-11

    There are growing strains on the electric grid as cooling peaks grow and equipment ages. Increased penetration of renewables on the grid is also straining electricity supply systems and the need for flexible demand is growing. This paper summarizes results of a series of field test of automated demand response systems in large buildings in the Pacific Northwest. The objective of the research was two fold. One objective was to evaluate the use demand response automation technologies. A second objective was to evaluate control strategies that could change the electric load shape in both winter and summer conditions. Winter conditions focused on cold winter mornings, a time when the electric grid is often stressed. The summer test evaluated DR strategies in the afternoon. We found that we could automate both winter and summer control strategies with the open automated demand response communication standard. The buildings were able to provide significant demand response in both winter and summer events.

  12. Increased carrying capacity with perennial forage kochia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Carrying capacity can be increased on grass-dominated rangeland pastures by including perennial forage kochia (Kochia prostrata) as one of the plant components. The objectives of the study reported here were to compare the differences of traditional winter pastures versus pastures with forage kochi...

  13. Autumn–winter diet of Grey Partridges Perdix perdix in winter crops, stubble fields and fallows

    Microsoft Academic Search

    Grzegorz Or?owski; Joanna Czarnecka; Marek Panek

    2011-01-01

    Capsule Diet composition differed significantly between winter cereals, winter oil-seed rape, stubble fields and permanent fallows.Aims To determine the composition of the diet of Grey Partridges in autumn and winter in four agricultural land-cover types, characteristic of lowland areas of Central Europe.Methods Faecal analysis was used to determine diet. Multivariate analysis of variance (manova), Simpson Index of Diversity (sid) and

  14. Winter climate change and coastal wetland foundation species: salt marshes vs. mangrove forests in the southeastern United States.

    PubMed

    Osland, Michael J; Enwright, Nicholas; Day, Richard H; Doyle, Thomas W

    2013-05-01

    We live in an era of unprecedented ecological change in which ecologists and natural resource managers are increasingly challenged to anticipate and prepare for the ecological effects of future global change. In this study, we investigated the potential effect of winter climate change upon salt marsh and mangrove forest foundation species in the southeastern United States. Our research addresses the following three questions: (1) What is the relationship between winter climate and the presence and abundance of mangrove forests relative to salt marshes; (2) How vulnerable are salt marshes to winter climate change-induced mangrove forest range expansion; and (3) What is the potential future distribution and relative abundance of mangrove forests under alternative winter climate change scenarios? We developed simple winter climate-based models to predict mangrove forest distribution and relative abundance using observed winter temperature data (1970-2000) and mangrove forest and salt marsh habitat data. Our results identify winter climate thresholds for salt marsh-mangrove forest interactions and highlight coastal areas in the southeastern United States (e.g., Texas, Louisiana, and parts of Florida) where relatively small changes in the intensity and frequency of extreme winter events could cause relatively dramatic landscape-scale ecosystem structural and functional change in the form of poleward mangrove forest migration and salt marsh displacement. The ecological implications of these marsh-to-mangrove forest conversions are poorly understood, but would likely include changes for associated fish and wildlife populations and for the supply of some ecosystem goods and services. PMID:23504931

  15. Winter climate change and coastal wetland foundation species: salt marshes vs. mangrove forests in the southeastern United States

    USGS Publications Warehouse

    Osland, Michael J.; Day, Richard H.; Doyle, Thomas W.; Enwright, Nicholas

    2013-01-01

    We live in an era of unprecedented ecological change in which ecologists and natural resource managers are increasingly challenged to anticipate and prepare for the ecological effects of future global change. In this study, we investigated the potential effect of winter climate change upon salt marsh and mangrove forest foundation species in the southeastern United States. Our research addresses the following three questions: (1) What is the relationship between winter climate and the presence and abundance of mangrove forests relative to salt marshes; (2) How vulnerable are salt marshes to winter climate change-induced mangrove forest range expansion; and (3) What is the potential future distribution and relative abundance of mangrove forests under alternative winter climate change scenarios? We developed simple winter climate-based models to predict mangrove forest distribution and relative abundance using observed winter temperature data (1970–2000) and mangrove forest and salt marsh habitat data. Our results identify winter climate thresholds for salt marsh–mangrove forest interactions and highlight coastal areas in the southeastern United States (e.g., Texas, Louisiana, and parts of Florida) where relatively small changes in the intensity and frequency of extreme winter events could cause relatively dramatic landscape-scale ecosystem structural and functional change in the form of poleward mangrove forest migration and salt marsh displacement. The ecological implications of these marsh-to-mangrove forest conversions are poorly understood, but would likely include changes for associated fish and wildlife populations and for the supply of some ecosystem goods and services.

  16. Individual inconsistencies in basal and summit metabolic rate highlight flexibility of metabolic performance in a wintering passerine.

    PubMed

    Cortés, Pablo Andrés; Petit, Magali; Lewden, Agnès; Milbergue, Myriam; Vézina, François

    2015-03-01

    Resident passerines inhabiting high latitude environments are faced with strong seasonal changes in thermal conditions and energy availability. Summit metabolic rate (maximal metabolic rate elicited by shivering during cold exposure: M(sum)) and basal metabolic rate (BMR) vary in parallel among seasons and increase in winter due to cold acclimatization, and these adjustments are thought to be critical for survival. Wintering individuals expressing consistently higher M(sum) and BMR could therefore be seen as better performers with higher chances of winter survival than those exhibiting lower metabolic performance. In this study, we calculated repeatability to evaluate temporal consistency of body mass, BMR and M(sum) within and across three consecutives winters in black-capped chickadees (Poecile atricapillus). We found that body mass was significantly repeatable both within and across winters (R 0.51-0.90). BMR (R 0.29-0.47) was only repeatable within winter while M(sum) was repeatable both among (R 0.33-0.49) and within winters (R 0.33-0.49) with the magnitude and significance of repeatability in both variables depending on the year and whether they were corrected for body mass or body size. The patterns of repeatability observed among years also differed between the two variables. Our findings suggest that the relative ranking of individuals in winter metabolic performance is affected by local ecological conditions and can change within relatively short periods of time. PMID:25690265

  17. [Avian diversity in Wuhu City in summer and winter].

    PubMed

    Li, Yongmin; Wu, Xiaobing

    2006-02-01

    From May 2004 to February 2005, an investigation was made on the avian communities in four typical habitats, i.e., village and farmland, urban woodlot, floodplain, and riverine wetland in Wuhu City, with the related diversity indices analyzed. A total of 117 species belonging to 15 orders and 31 families was recorded. The avian species and G-F index in village and farmland, urban woodlot, and floodplain were higher in summer than in winter, while the species number, Shannon-Wiener index and Pielou index in riverine wetland were significantly higher in winter than in summer. The avian species and G-F index in urban woodlot were the highest, and the Shannon-Wiener index and Pielou index in floodplain were higher than those in other three habitats. The highest density was observed in village and farmland in summer and in urban woodlot in winter, being 31.1140 and 42.9160 ind x hm(-2), respectively. The avian species, density, Shannon-Wiener index and G-F index in riverine wetland were the lowest. Avian diversity could be enhanced by increasing spatial heterogeneity and reducing human disturbance. PMID:16706052

  18. [Paediatric emergencies; example of the management of winter epidemics].

    PubMed

    Mercier, Jean-Christophe; Bellettre, Xavier; Lejay, Émilie; Desmarest, Marie; Titomanlio, Luigi

    2015-01-01

    Every year, epidemics of viral bronchiolitis and gastroenteritis occur with a significant increase in the number of visits (by a factor 1.8) and hospitalisations that can over-exceed bed capacity leading to transfer sick children to other hospitals. This kind of hospital 'crisis' is not limited to paediatrics, big cities or western nations. It is a worldwide worrying problem. Because our hospital sits in the Northern districts of Paris where a large community of m.ncants lives in poverty, our number of visits is high (mean 250 per day), and winter epidemics further jeopardise the difficult equilibrium achieved between quality management and waiting times. Thus, we have taken various initiatives in terms of organisation of the paediatric emergency department and other wards, including a "fast track" clinic, the opening of beds dedicated to winter epidemics, the institution of a "bed manager" in order to more easily find a bed, and a larger use of home hospitalisations. Furthermore, we created a specific committee which may decide on various indicators of tension whether it is necessary to cancel programmed hospitalisations or surgery.in order to resolve the emergency crisis. This kind of organisation can serve as a model for other hospitals facing winter epidemics crises. PMID:25842428

  19. Dynamical roles of planetary waves on the winter anomaly in the middle and lower latitudes

    Microsoft Academic Search

    K. Kawahira

    1985-01-01

    The winter anomaly of radio wave absorption in the ionospheric D region (65 to 90 km), caused by a factor of about ten increase in electron density, has been considered to be due to a factor of about ten increase of the nitric oxide concentration and\\/or a few tens of degrees Kelvin temperature rise due to a strong temperature dependency

  20. Simulating the winter North Atlantic Oscillation: the roles of internal variability and greenhouse gas forcing

    Microsoft Academic Search

    T. J. Osborn

    2004-01-01

    Analysis of simulations with seven coupled climate models demonstrates that the observed variations in the winter North Atlantic Oscillation (NAO), particularly the increase from the 1960s to the 1990s, are not compatible with either the internally generated variability nor the response to increasing greenhouse gas forcing simulated by these models. The observed NAO record can be explained by a combination

  1. MKTG 456: International Marketing Winter 2012 Syllabus

    E-print Network

    Carter, John

    MKTG 456: International Marketing Winter 2012 Syllabus Class Meeting Times: Tuesday/Thursday 10 and by appointment (usually available after class) COURSE DESCRIPTION Addresses market segmentation, product analyze international marketing problems/opportunities and apply marketing concepts for solutions

  2. Probabilistic Weather Forecasting for Winter Road Maintenance

    E-print Network

    Washington at Seattle, University of

    Probabilistic Weather Forecasting for Winter Road Maintenance Veronica J. Berrocal, Adrian E are needed. Currently, anti-icing decisions are usually based on deterministic weather forecasts. However. Starting with deterministic numerical weather predictions, they produce a joint predictive probability dis

  3. How to Find Insects Weathering the Winter.

    ERIC Educational Resources Information Center

    Brody, Jane

    1979-01-01

    Discusses how and where to find insects and other invertebrates in winter, as well as how to collect samples in order to watch those animals reappear in spring. Includes crickets, honey bees, mosquitoes, house flies, and butterflies and moths. (MA)

  4. CHEMICAL ENGINEERING Fall 2013-Winter 2014

    E-print Network

    California at Davis, University of

    ADVANCED CHEMICAL ENGINEERING Fall 2013-Winter 2014 Certificate Program CONTINUING AND PROFESSIONAL EDUCATIONCONTINUING AND PROFESSIONAL EDUCATION #12;About the Advanced Chemical Engineering Certificate Program The new Advanced Chemical Engineering Certificate Program offers professionals in chemi- cal engineering

  5. Samantha Woodward Winter 2011-2012

    E-print Network

    to simply achieve the tightest compression possible and save storage space on a computer, or compress Woodward BIOC 218 Winter 2011-2012 3 need for full genome databases valid. At this point some researchers

  6. AMAT/PMAT 4282 { Winter 2001 Cryptography

    E-print Network

    deYoung, Brad

    AMAT/PMAT 4282 { Winter 2001 Cryptography Instructor #15; Name: Dr. David Pike #15; OÆce: Henrietta Number Theory) and a computing course (AMAT 2120 or CS 2710 or CS 2602). #15; Textbook: \\Cryptography

  7. Winter water relations of New England conifers and factors influencing their upper elevational limits. II. Modeling.

    PubMed

    Boyce, Richard L; Vostral, Chandra B; Friedland, Andrew J

    2002-08-01

    We used the water relations model, WINWAT, to model winter water relations of three conifer species-eastern hemlock (Tsuga canadensis (L.) Carr.), eastern white pine (Pinus strobus L.) and red pine (P. resinosa Ait.)-growing at their upper elevational limits on Mt. Ascutney, Vermont, USA, in the winters of 1997 and 1999. Modeled relative water contents remained above 60% in the two youngest foliar age classes of all three species during both winters, indicating that desiccation stress in winter is not responsible for setting the upper elevational limits of these species at this site under present climatic conditions. WINWAT indicated that winter water relations of these low-elevational species were sensitive to low relative humidity, which increased transpiration rates, and low temperatures, which inhibited recharge, but are much less sensitive to summer climate than in the case of subalpine conifers in Colorado. Our results indicate that summer and winter temperatures and relative humidities (or precipitation/potential evapotranspiration ratios) should be incorporated into climate change models designed to simulate future tree distributions. PMID:12184984

  8. Winter feeding activity of the common starfish (Asterias rubens L.): The role of temperature and shading

    NASA Astrophysics Data System (ADS)

    Agüera, Antonio; Trommelen, Michel; Burrows, Frances; Jansen, Jeroen M.; Schellekens, Tim; Smaal, Aad

    2012-08-01

    In the Wadden Sea common starfish is an important predator of mussel beds which in turn are relevant ecological and economic resource. To improve the management of mussel seedbeds, knowledge is required on over winter predation, a factor affecting mussel survival. The aim of this study was to assess the importance of A. rubens feeding activity during winter and how it relates with changes in temperature. Feeding activity of starfish was monitored during a full winter. The potential impact of temperature change on starfish-mussel seed interactions during winter was analysed. The factor shading was included, as changes in light intensity appear to be a primary governing factor for the timing of feeding activity. The results showed that temperature limits feeding rate and feeding activity of starfish during winter. However, starfish feeding rate exhibited very high sensitivity to temperature changes. Light intensity affected both feeding rate and feeding activity. It is concluded that starfish may not be an important factor destabilising seedbeds during a mean winter, but its importance may grow along with the increasing temperature due to climate change.

  9. [Effects of different irrigation modes in winter wheat growth season on the grain yield and water use efficiency of winter wheat-summer maize].

    PubMed

    Wang, Hai-xia; Li, Yu-yi; Ren, Tian-zhi; Pang, Huan-cheng

    2011-07-01

    Three irrigation modes in winter wheat growth season were carried out in Heilonggang basin of North China Plain to investigate their effects on the grain yield, water consumption, and water use efficiency (WUE) of winter wheat-summer maize. The three irrigation modes included irrigation before sowing (75 mm, W1), irrigation before sowing and at jointing stage (75 mm + 90 mm, W2), and irrigation before sowing, at jointing stage, and at filling stage (75 mm + 90 mm + 60 mm, W3). With the irrigation modes W2 and W3, the increment of the annual yield of winter wheat-summer maize was 8.7% and 12.5% higher than that with W1, respectively. The water consumption in winter wheat growth season decreased with increasing irrigation amount, while that in summer maize growth season increased with the increasing irrigation amount in winter wheat growth season. The WUE of winter wheat with the irrigation mode W2 was 11.1% higher than that with W3, but the WUE of summer maize had less difference between irrigation modes W2 and W3. The annual WUE (WUE(T)) of W2 and W1 was 21.28 and 21.60 kg(-1) x mm x hm(-2), being 7.8% and 9.4% higher than that of W3, respectively. Considering the annual yield, water consumption, and WUE, irrigation mode W2 could be the advisable mode for water-saving and high-yielding. PMID:22007452

  10. Simulating the influences of various fire regimes on caribou winter habitat

    USGS Publications Warehouse

    Rupp, T.S.; Olson, M.; Adams, L.G.; Dale, B.W.; Joly, Kyle; Henkelman, J.; Collins, W.B.; Starfield, A.M.

    2006-01-01

    Caribou are an integral component of high-latitude ecosystems and represent a major subsistence food source for many northern people. The availability and quality of winter habitat is critical to sustain these caribou populations. Caribou commonly use older spruce woodlands with adequate terrestrial lichen, a preferred winter forage, in the understory. Changes in climate and fire regime pose a significant threat to the long-term sustainability of this important winter habitat. Computer simulations performed with a spatially explicit vegetation succession model (ALFRESCO) indicate that changes in the frequency and extent of fire in interior Alaska may substantially impact the abundance and quality of winter habitat for caribou. We modeled four different fire scenarios and tracked the frequency, extent, and spatial distribution of the simulated fires and associated changes to vegetation composition and distribution. Our results suggest that shorter fire frequencies (i.e., less time between recurring fires) on the winter range of the Nelchina caribou herd in eastern interior Alaska will result in large decreases of available winter habitat, relative to that currently available, in both the short and long term. A 30% shortening of the fire frequency resulted in a 3.5-fold increase in the area burned annually and an associated 41% decrease in the amount of spruce-lichen forest found on the landscape. More importantly, simulations with more frequent fires produced a relatively immature forest age structure, compared to that which currently exists, with few stands older than 100 years. This age structure is at the lower limits of stand age classes preferred by caribou from the Nelchina herd. Projected changes in fire regime due to climate warming and/or additional prescribed burning could substantially alter the winter habitat of caribou in interior Alaska and lead to changes in winter range use and/or population dynamics. ?? 2006 by the Ecological Society of America.

  11. The Importance of Winter for Controlling the Growing Season Net Ecosystem Exchange (NEE) of Boreal Forests

    NASA Astrophysics Data System (ADS)

    Oquist, M. G.; Peichl, M.; Ottosson Lofvenius, M.; Nilsson, M. B.

    2014-12-01

    It is becoming increasingly apparent that the winter season of high latitudes can be important for controlling a range of ecological and biogeochemical properties of northern ecosystems. Here we evaluate the importance of winter conditions on the carbon exchange between boreal forest systems and the atmosphere during the following growing season in order to elucidate any influence of inter-seasonal "memory" effects on carbon exchange properties of boreal forest ecosystems. The study is based on 5 years of continuous eddy covariance measurements at two ca 50 year old Norway spruce stands situated in mid- and northern Sweden, respectively (a total of 10 site years). The growing season net ecosystem exchange (NEE) ranged from -530 to -60 g C m-2 (negative values indicates carbon sinks). Environmental conditions during the growing season (e.g. temperature, radiation, length) only weakly explained the year-to-year variability in NEE. In contrast, up to 75% of the variation could be explained by the severity of the preceding winter (defined as the lowest observed average weekly air temperature) using an exponential response function. After warm winters the carbon sink properties were high as compared to those observed after cold winters. The winter conditions markedly affected the systems potential for carbon uptake in early summer. This presentation will address the potential mechanisms underpinning the observed correlations linking growing season carbon exchange to the conditions of the preceding winter. The influence of winter on the partitioned carbon fluxes of ecosystem respiration and gross primary productivity, respectively, will also be addressed. The results strongly indicate that controls on boreal forest carbon exchange can transcend across seasons. Understanding these mechanisms are integral for understanding the environmental drivers of atmospheric carbon exchange, allowing for accurate predictions of boreal forest NEE under both present and future climates.

  12. Climate Change Affects Winter Chill for Temperate Fruit and Nut Trees

    PubMed Central

    Luedeling, Eike; Girvetz, Evan H.; Semenov, Mikhail A.; Brown, Patrick H.

    2011-01-01

    Background Temperate fruit and nut trees require adequate winter chill to produce economically viable yields. Global warming has the potential to reduce available winter chill and greatly impact crop yields. Methodology/Principal Findings We estimated winter chill for two past (1975 and 2000) and 18 future scenarios (mid and end 21st century; 3 Global Climate Models [GCMs]; 3 greenhouse gas emissions [GHG] scenarios). For 4,293 weather stations around the world and GCM projections, Safe Winter Chill (SWC), the amount of winter chill that is exceeded in 90% of all years, was estimated for all scenarios using the “Dynamic Model” and interpolated globally. We found that SWC ranged between 0 and about 170 Chill Portions (CP) for all climate scenarios, but that the global distribution varied across scenarios. Warm regions are likely to experience severe reductions in available winter chill, potentially threatening production there. In contrast, SWC in most temperate growing regions is likely to remain relatively unchanged, and cold regions may even see an increase in SWC. Climate change impacts on SWC differed quantitatively among GCMs and GHG scenarios, with the highest GHG leading to losses up to 40 CP in warm regions, compared to 20 CP for the lowest GHG. Conclusions/Significance The extent of projected changes in winter chill in many major growing regions of fruits and nuts indicates that growers of these commodities will likely experience problems in the future. Mitigation of climate change through reductions in greenhouse gas emissions can help reduce the impacts, however, adaption to changes will have to occur. To better prepare for likely impacts of climate change, efforts should be undertaken to breed tree cultivars for lower chilling requirements, to develop tools to cope with insufficient winter chill, and to better understand the temperature responses of tree crops. PMID:21629649

  13. Does Day Length Affect Winter Bird Distribution? Testing the Role of an Elusive Variable

    PubMed Central

    Carrascal, Luis M.; Santos, Tomás; Tellería, José L.

    2012-01-01

    Differences in day length may act as a critical factor in bird biology by introducing time constraints in energy acquisition during winter. Thus, differences in day length might operate as a main determinant of bird abundance along latitudinal gradients. This work examines the influence of day length on the abundance of wintering crested tits (Lophophanes cristatus) in 26 localities of Spanish juniper (Juniperus thurifera) dwarf woodlands (average height of 5 m) located along a latitudinal gradient in the Spanish highlands, while controlling for the influence of food availability, minimum night temperature, habitat structure and landscape characteristics. Top regression models in the AIC framework explained 56% of variance in bird numbers. All models incorporated day length as the variable with the highest magnitude effect. Food availability also played an important role, although only the crop of ripe juniper fruits, but not arthropods, positively affected crested tit abundance. Differences in vegetation structure across localities had also a strong positive effect (average tree height and juniper tree density). Geographical variation in night temperature had no influence on crested tit distribution, despite the low winter temperatures reached in these dwarf forests. This paper demonstrates for the first time that winter bird abundance increases with day length after controlling for the effect of other environmental variables. Winter average difference in day length was only 10.5 minutes per day along the 1°47? latitudinal interval (190 km) included in this study. This amount of time, which reaches 13.5 h accumulated throughout the winter season, appears to be large enough to affect the long-term energy budget of small passerines during winter and to shape the distribution of winter bird abundance under restrictive environmental conditions. PMID:22393442

  14. Student Involvement Winter Quarter 2012 Calendar

    E-print Network

    Borenstein, Elhanan

    SAB: The Year of the Dragon 3 SAB: Dinner Theater 4 5 BLACK HISTORY MONTH 6 SAB: Bowling Night R: Comedy Night Derek Gains 9 R/F: Zumba 7-8pm 10 SAB: 4th Annual Winter Ball : Winter Wonderland STFC Special Allocations Due 11 12 13 R/F: Noon Ball 11am-1pm R/F: Boot Camp 6-7pm 14 Valentines Day SAB

  15. Wintering Steer Calves at the Spur Station. 

    E-print Network

    Jones, J. H.; Fisher, C. E.; Marion, P. T.

    1956-01-01

    trials, in most instances, were based on 3 or more years of work. Roughages used in wintering steer calves weighing 325 to 400 pounds were wheat pasture, natire grass, sorghum silage, bundle feeds and stalk fields. Protein supplements were fed... and summer gain. When stocked at the same rate, almost identical gains were made by calves grazed on all wheat and wheat-sorghum pasture combinations. The winter-grazing season averaged 54 days. Lightly grazed or summer-deferred native grass supplemented...

  16. Increasing Rigor

    ERIC Educational Resources Information Center

    Blackburn, Barbara; Williamson, Ronald

    2009-01-01

    As educators increasingly focus on increasing the level of rigor in their schools, it is important to first agree on what rigor is. Rigor is more than just the content of the lesson or even what teachers expect students to do. Too often, teachers simply raise expectations without providing appropriate support for students to succeed. True rigor…

  17. Is winter worse for stressed fish? The consequences of exogenous cortisol manipulation on over-winter survival and condition of juvenile largemouth bass.

    PubMed

    Binder, Thomas R; O'Connor, Constance M; McConnachie, Sarah H; Wilson, Samantha M; Nannini, Michael A; Wahl, David H; Cooke, Steven J

    2015-09-01

    Over-winter mortality is an important selective force for warm-water fish (e.g., centrarchids) that live in temperate habitats. Inherent challenges faced by fish during winter may be compounded by additional stressors that activate the hypothalamic-pituitary-interrenal axis, either before or during winter, leading to negative sub-lethal impacts on fish health and condition, and possibly reducing chance of survival. We used experimental cortisol manipulation to test the hypothesis that juvenile largemouth bass (Micropterus salmoides) exposed to semi-chronic elevation in cortisol prior to winter would experience higher levels of over-winter mortality, physiological alterations and impaired immune status relative to control and sham-treated bass. Over-winter survival in experimental ponds was high, averaging 83%, and did not differ among treatment groups. Over the study period, bass exhibited an average increase in mass of 19.4%, as well as a slight increase in Fulton's condition factor, but neither measure differed among groups. Hepatosomatic index in cortisol-treated bass was 23% lower than in control fish, suggesting lower energy status, but white muscle lipid content was similar across all groups. Lastly, there was no difference in spleen somatic index or parasite load among treatment groups, indicating no long-term immune impairment related to our cortisol manipulation. The current study adds to a growing body of literature on glucocorticoid manipulations where field-based findings are not consistent with laboratory-based conceptual understanding of multiple stressors. This suggests that field conditions may provide fish with opportunities to mitigate negative effects of some stressors. PMID:26006297

  18. Characteristics of foraging sites and protein status in wintering muskoxen: Insights from isotopes of nitrogen

    USGS Publications Warehouse

    Gustine, D.D.; Barboza, P.S.; Lawler, J.P.; Arthur, S.M.; Shults, B.S.; Persons, K.; Adams, L.G.

    2011-01-01

    Identifying links between nutritional condition of individuals and population trajectories greatly enhances our understanding of the ecology, conservation, and management of wildlife. For northern ungulates, the potential impacts of a changing climate to populations are predicted to be nutritionally mediated through an increase in the severity and variance in winter conditions. Foraging conditions and the availability of body protein as a store for reproduction in late winter may constrain productivity in northern ungulates, yet the link between characteristics of wintering habitats and protein status has not been established for a wild ungulate. We used a non-invasive proxy of protein status derived from isotopes of N in excreta to evaluate the influence of winter habitats on the protein status of muskoxen in three populations in Alaska (2005-2008). Multiple regression and an information-theoretic approach were used to compare models that evaluated the influence of population, year, and characteristics of foraging sites (components of diet and physiography) on protein status for groups of muskoxen. The observed variance in protein status among groups of muskoxen across populations and years was partially explained (45%) by local foraging conditions that affected forage availability. Protein status improved for groups of muskoxen as the amount of graminoids in the diet increased (-0.430 ?? 0.31, ???? 95% CI) and elevation of foraging sites decreased (0.824 ?? 0.67). Resources available for reproduction in muskoxen are highly dependent upon demographic, environmental, and physiographic constraints that affect forage availability in winter. Due to their very sedentary nature in winter, muskoxen are highly susceptible to localized foraging conditions; therefore, the spatial variance in resource availability may exert a strong effect on productivity. Consequently, there is a clear need to account for climate-topography effects in winter at multiple scales when predicting the potential impacts of climatic shifts on population trajectories of muskoxen. ?? 2011 The Authors.

  19. Soil bacteria as selective biological control agents of winter annual grass weeds in winter wheat

    Microsoft Academic Search

    Pamela A. Harris; Phillip W. Stahlman

    1996-01-01

    Many winter annual grass weeds, such as downy brome (Bromus tectorum L.) and jointed goatgrass Aegilops cylindrica Host.), are difficult to control selectively in winter wheat (Triticum aestivum L.) grown in the central and western US. The difficulty is due partially to a lack of selective chemical herbicides. Bacteria were isolated from soil and plant roots and evaluated for inhibition

  20. P/1WINTER 2014 Welcome to the Winter 2014 issue of the Stanford Cancer

    E-print Network

    Bejerano, Gill

    clinical studies and treatment expertise for complex cancers of the prostate, kidney, bladder, and testisP/1WINTER 2014 Welcome to the Winter 2014 issue of the Stanford Cancer Institute Clinical Research, and especially physicians who are considering treatment options for their patients with cancer, about clinical

  1. Flavor Characterization of Breads Made from Hard Red Winter Wheat and Hard White Winter Wheat

    Microsoft Academic Search

    CHUN-YEN CHANG; EDGAR CHAMBERS

    Cereal Chem. 69(5):556-559 Sensory flavor profiles for white pan bread and whole wheat bread impression than did HRW crust. HRW crumb was sweeter and more made from hard red winter (HRW) or hard white winter (HWW) wheat dairylike than HWW crumb. HWW crumb had a phenoliclike note not were developed by a professionally trained panel. The flavors of crust present

  2. Winter Morning in Northern Tharsis

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Mars Global Surveyor's camera, MOC, provided this hemispheric view of the northern Tharsis region on June 1, 1998. This picture shows the giant volcano, Olympus Mons, and one of the Tharsis Montes volcanoes, Ascraeus Mons. Another volcano, Alba Patera, is lurking under the haze and clouds at the top of the image. Olympus Mons is about 550 kilometers (340 miles) wide.

    MGS is now in a 'morning' orbit (when it arrived at Mars in September 1997, it was inserted into a 'late afternoon' orbit). The orbit will continue to change, about one hour a month, until aerobraking into a circular orbit is complete about seven months from now. When this picture was taken, the local time on the ground beneath the spacecraft was about 9:30 a.m. The terminator-- the line that divides night and day-- was located west of Olympus Mons (left part of the image). It is winter in the northern hemisphere of Mars, and the high latitudes (i.e., north of Olympus Mons in this picture) exhibit clouds and haze. These clouds most likely contain water ice.

    MOC images 33901 (the red wide angle image) and 33902 (the blue wide angle image) were obtained on Mars Global Surveyor's 339th orbit about the planet. The pictures were taken around 7:37 p.m. PDT on June 1, 1998.

    Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

  3. Field Observations and Modeling of the Microphysics within Winter Storms over Long Island, NY

    NASA Astrophysics Data System (ADS)

    Stark, David

    Forecasting snowfall accumulation is challenging due to limitations and uncertainties in model bulk microphysical parameterizations (BMPs). The source of these errors is often unknown, since there have been relatively few in situ observations of the microphysics (ice habit, degree of riming, and snow density) during east coast winter storms. This thesis describes the microphysical evolution and model validation within east coast winter storms observed at Stony Brook, NY (SBNY) during the 2009-2010, 2010-2011, and 2011-2012 winter seasons. Surface microphysical measurements were taken every 15 to 30 minutes using a stereo microscope and camera, and snow depth and snow density were also recorded in 15 storms over SBNY. During these storms, a vertically-pointing Ku-band radar was used to observe the vertical evolution of reflectivity and Doppler vertical velocities. A Particle Size and Velocity (PARSIVEL) disdrometer was also used to measure the surface size distribution and fall speeds of snow at SBNY. Changes in the height of the maximum vertical motion relative to the favored growth temperatures led to changes in ice habit throughout the evolution in the comma head of extratropical cyclones and two heavy snow bands. Cold type ice habits with a few plates and dendrites were observed with light riming as the surface low was located along or east of the Mid-Atlantic coast. As the cyclone moved northward towards SBNY, moderately rimed dendrites, plates, and needles were observed. Heavily rimed needles and graupel were observed near the warm front and cyclone center. Mainly needles with light riming and a snow-liquid ratio from 8:1 to 9:1 were observed 2 to 4 hours before two heavy snow bands. With the strongest frontogenetical ascent during snow band maturity, moderately rimed dendrites were observed with snow-liquid ratios from 11:1 to 13:1. Lightly rimed plates and a snow-liquid ratio of 8:1 were observed after the heavy snow bands. The WSM6, MORR, THOM2, and SBU-YLIN BMPs were validated in this study. A non-spherical snow assumption (THOM2 and SBU-YLIN) simulated a more realistic distribution of reflectivity than spherical snow assumptions in the WSM6 and MORR schemes. In heavier riming, the Doppler velocity in the WSM6, THOM2, and MORR schemes were ˜0.25 m s-1 too slow with the SBU-YLIN was 0.25 to 0.5 m s-1 too fast. For size distributions, the BMPs simulate a smaller size distribution than observed when larger aggregates are observed for D > 6 mm. For snow density forecasts, the Roebber probabilistic snow-liquid ratio approach provides more skill than using the standard 10:1 ratio or deterministic forecasts from the WRF BMPs.

  4. Association of wintering raptors with Conservation Reserve Enhancement Program grasslands in Pennsylvania

    USGS Publications Warehouse

    Wilson, A.; Brittingham, M.; Grove, G.

    2010-01-01

    Conservation grasslands can provide valuable habitat resource for breeding songbirds, but their value for wintering raptors has received little attention. We hypothesized that increased availability of grassland habitat through the Conservation Reserve Enhancement Program (CREP) has resulted in an increase or redistribution in numbers of four species of raptors in Pennsylvania since 2001. We tested this by analyzing winter raptor counts from volunteer surveys, conducted from 2001 to 2008, for Red-tailed Hawks (Buteo jamaicensis), Rough-legged Hawks (Buteo lagopus), Northern Harriers (Circus cyaneus), and American Kestrels (Falco sparverius). During that period, numbers of wintering Northern Harriers increased by more than 20% per year. Log-linear Poisson regression models show that all four species increased in the region of Pennsylvania that had the most and longest-established conservation grasslands. At the county scale (N= 67), Bayesian spatial models showed that spatial and temporal population trends of all four species were positively correlated with the amount of conservation grassland. This relationship was particularly strong for Northern Harriers, with numbers predicted to increase by 35.7% per year for each additional 1% of farmland enrolled in CREP. Our results suggest that conservation grasslands are likely the primary cause of the increase in numbers of wintering Northern Harriers in Pennsylvania since 2001. ?? 2010 The Authors. Journal of Field Ornithology ?? 2010 Association of Field Ornithologists.

  5. Winter Temperature Affects the Prevalence of Ticks in an Arctic Seabird

    PubMed Central

    Descamps, Sébastien

    2013-01-01

    The Arctic is rapidly warming and host-parasite relationships may be modified by such environmental changes. Here, I showed that the average winter temperature in Svalbard, Arctic Norway, explained almost 90% of the average prevalence of ticks in an Arctic seabird, the Brünnich’s guillemot Uria lomvia. An increase of 1°C in the average winter temperature at the nesting colony site was associated with a 5% increase in the number of birds infected by these ectoparasites in the subsequent breeding season. Guillemots were generally infested by only a few ticks (?5) and I found no direct effect of tick presence on their body condition and breeding success. However, the strong effect of average winter temperature described here clearly indicates that tick-seabird relationships in the Arctic may be strongly affected by ongoing climate warming. PMID:23750259

  6. Winter warming delays dormancy release, advances budburst, alters carbohydrate metabolism and reduces yield in a temperate shrub

    PubMed Central

    Pagter, Majken; Andersen, Uffe Brandt; Andersen, Lillie

    2015-01-01

    Global climate models predict an increase in the mean surface air temperature, with a disproportionate increase during winter. Since temperature is a major driver of phenological events in temperate woody perennials, warming is likely to induce changes in a range of these events. We investigated the impact of slightly elevated temperatures (+0.76 °C in the air, +1.35 °C in the soil) during the non-growing season (October–April) on freezing tolerance, carbohydrate metabolism, dormancy release, spring phenology and reproductive output in two blackcurrant (Ribes nigrum) cultivars to understand how winter warming modifies phenological traits in a woody perennial known to have a large chilling requirement and to be sensitive to spring frost. Warming delayed dormancy release more in the cultivar ‘Narve Viking’ than in the cultivar ‘Titania’, but advanced budburst and flowering predominantly in ‘Titania’. Since ‘Narve Viking’ has a higher chilling requirement than ‘Titania’, this indicates that, in high-chilling-requiring genotypes, dormancy responses may temper the effect of warming on spring phenology. Winter warming significantly reduced fruit yield the following summer in both cultivars, corroborating the hypothesis that a decline in winter chill may decrease reproductive effort in blackcurrant. Elevated winter temperatures tended to decrease stem freezing tolerance during cold acclimation and deacclimation, but it did not increase the risk of freeze-induced damage mid-winter. Plants at elevated temperature showed decreased levels of sucrose in stems of both cultivars and flower buds of ‘Narve Viking’, which, in buds, was associated with increased concentrations of glucose and fructose. Hence, winter warming influences carbohydrate metabolism, but it remains to be elucidated whether decreased sucrose levels account for any changes in freezing tolerance. Our results demonstrate that even a slight increase in winter temperature may alter phenological traits in blackcurrant, but to various extents depending on genotype-specific differences in chilling requirement. PMID:25802249

  7. Winter warming delays dormancy release, advances budburst, alters carbohydrate metabolism and reduces yield in a temperate shrub.

    PubMed

    Pagter, Majken; Andersen, Uffe Brandt; Andersen, Lillie

    2015-01-01

    Global climate models predict an increase in the mean surface air temperature, with a disproportionate increase during winter. Since temperature is a major driver of phenological events in temperate woody perennials, warming is likely to induce changes in a range of these events. We investigated the impact of slightly elevated temperatures (+0.76 °C in the air, +1.35 °C in the soil) during the non-growing season (October-April) on freezing tolerance, carbohydrate metabolism, dormancy release, spring phenology and reproductive output in two blackcurrant (Ribes nigrum) cultivars to understand how winter warming modifies phenological traits in a woody perennial known to have a large chilling requirement and to be sensitive to spring frost. Warming delayed dormancy release more in the cultivar 'Narve Viking' than in the cultivar 'Titania', but advanced budburst and flowering predominantly in 'Titania'. Since 'Narve Viking' has a higher chilling requirement than 'Titania', this indicates that, in high-chilling-requiring genotypes, dormancy responses may temper the effect of warming on spring phenology. Winter warming significantly reduced fruit yield the following summer in both cultivars, corroborating the hypothesis that a decline in winter chill may decrease reproductive effort in blackcurrant. Elevated winter temperatures tended to decrease stem freezing tolerance during cold acclimation and deacclimation, but it did not increase the risk of freeze-induced damage mid-winter. Plants at elevated temperature showed decreased levels of sucrose in stems of both cultivars and flower buds of 'Narve Viking', which, in buds, was associated with increased concentrations of glucose and fructose. Hence, winter warming influences carbohydrate metabolism, but it remains to be elucidated whether decreased sucrose levels account for any changes in freezing tolerance. Our results demonstrate that even a slight increase in winter temperature may alter phenological traits in blackcurrant, but to various extents depending on genotype-specific differences in chilling requirement. PMID:25802249

  8. Selenium concentrations in greater scaup and dreissenid mussels during winter on Western lake ontario.

    PubMed

    Ware, L L; Petrie, S A; Badzinski, S S; Bailey, R C

    2011-08-01

    One hypothesis for the decline of the North American greater (Aythya marila) and lesser (A. affinis) scaup population is that contaminant burdens acquired on wintering or staging areas impair reproduction or cause lethal or sublethal health effects. Recent studies have found increased selenium (Se) concentrations in scaup but have focused on the fall and spring staging periods. From January to March 2006 and December to March 2006 and 2007, we analyzed liver tissues collected from greater scaup wintering in western Lake Ontario for 16 trace elements. We also measured Se concentrations in greater scaup blood and Dreissenid mussel tissue. Se was the only trace element that occurred at increased concentrations (>10 ?g/g liver dry weight) in a substantial proportion (99%) of greater scaup livers. We also found that hepatic Se concentrations increased throughout winter and were increased in nearly all birds from January to March, suggesting that accumulation of this trace element occurred soon after their arrival in fall. Se concentrations were similar in male and female birds, but juvenile birds had higher concentrations than did adults. Blood Se concentrations were correlated to liver Se concentrations in 2006 only, suggesting that blood Se concentration is an unreliable predictor of liver concentration. Se in Dreissenid mussels generally decreased with mussel size and did not change throughout winter. Overall, our results suggest that greater scaup wintering on western Lake Ontario acquire sufficiently high Se concentrations to potentially impact their health. Thus, several indicators of health and survival should be examined in relation to Se concentrations in wintering scaup. PMID:21120462

  9. Pinatubo eruption winter climate effects: Model versus observations

    NASA Technical Reports Server (NTRS)

    Graf, HANS-F.; Kirchner, Ingo; Schult, Ingrid; Robock, Alan

    1992-01-01

    Large volcanic eruptions, in addition to the well-known effect of producing global cooling for a year or two, have been observed to produce shorter-term responses in the climate system involving non-linear dynamical processes. In this paper, we use the ECHAM2 general circulation model forced with stratospheric aerosols to test some of these ideas. Run in a perpetual-January mode, with tropical stratospheric heating from the volcanic aerosols typical of the 1982 El Chichon eruption or the 1991 Pinatubo eruption, we find a dynamical response with an increased polar night jet in the Northern Hemisphere (NH) and stronger zonal winds which extended down into the troposphere. The Azores High shifts northward with increased tropospheric westerlies at 60N and increased easterlies at 30N. Surface temperatures are higher both in northern Eurasia and North America, in agreement with observations for the NH winters or 1982-83 and 1991-92 as well as the winters following the other 10 largest volcanic eruptions since 1883.

  10. Attribution of UK Winter Floods to Anthropogenic Forcing

    NASA Astrophysics Data System (ADS)

    Schaller, N.; Alison, K.; Sparrow, S. N.; Otto, F. E. L.; Massey, N.; Vautard, R.; Yiou, P.; van Oldenborgh, G. J.; van Haren, R.; Lamb, R.; Huntingford, C.; Crooks, S.; Legg, T.; Weisheimer, A.; Bowery, A.; Miller, J.; Jones, R.; Stott, P.; Allen, M. R.

    2014-12-01

    Many regions of southern UK experienced severe flooding during the 2013/2014 winter. Simultaneously, large areas in the USA and Canada were struck by prolonged cold weather. At the time, the media and public asked whether the general rainy conditions over northern Europe and the cold weather over North America were caused by climate change. Providing an answer to this question is not trivial, but recent studies show that probabilistic event attribution is feasible. Using the citizen science project weather@home, we ran over 40'000 perturbed initial condition simulations of the 2013/2014 winter. These simulations fall into two categories: one set aims at simulating the world with climate change using observed sea surface temperatures while the second set is run with sea surface temperatures corresponding to a world that might have been without climate change. The relevant modelled variables are then downscaled by a hydrological model to obtain river flows. First results show that anthropogenic climate change led to a small but significant increase in the fractional attributable risk for 30-days peak flows for the river Thames. A single number can summarize the final result from probabilistic attribution studies indicating, for example, an increase, decrease or no change to the risk of the event occurring. However, communicating this to the public, media and other scientists remains challenging. The assumptions made in the chain of models used need to be explained. In addition, extreme events, like the UK floods of the 2013/2014 winter, are usually caused by a range of factors. While heavy precipitation events can be caused by dynamic and/or thermodynamic processes, floods occur only partly as a response to heavy precipitation. Depending on the catchment, they can be largely due to soil properties and conditions of the previous months. Probabilistic attribution studies are multidisciplinary and therefore all aspects need to be communicated properly.

  11. Increasing Yield

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize yield improvement in the 20th century represents one of the great success stories of plant breeding and agronomy. Maize grain yield in the United States has increased on average by 0.122 metric tons per hectare per year since 1945 (Figure 1). This is in sharp contrast to essentially zero gain ...

  12. Influence of food hoarding behavior on the over-winter survival of pikas in strongly seasonal environments

    Microsoft Academic Search

    Shawn F. Morrison; Graeme Pelchat; Aaron Donahue; David S. Hik

    2009-01-01

    Food hoarding is a behavioral adaptation of some herbivores to manage food availability through time and space. In strongly\\u000a seasonal environments, where summer growing seasons are short relative to winter, an earlier start to hoarding should increase\\u000a the amount of vegetation stored for winter and improve subsequent survival. We examined hoarding behavior (‘haying’) and its\\u000a impact on survival for a

  13. Analysis of Winter Operating Condition of Ground Source Heat Pump System in a Residential District of Qingdao

    Microsoft Academic Search

    Gang Wang; Binbin Zhang; Huihui Yin; Xuquan Li

    2009-01-01

    Aiming at the problem of increasing energy consumption of winter heating in northern china, a new heating system- ground source pump system has been put forward for heating. Take a residential district of Qingdao for example, analyzing and comparing dynamic characteristic of each parameter of winter start-up stage and quasi-steady-state stage of ground source heat pump, measures and ideas for

  14. Effects of drought on winter wheat yield in north China during 2012-2100

    NASA Astrophysics Data System (ADS)

    Song, Yanling; Zhao, Yanxia

    2012-08-01

    Winter wheat is one of China's most important staple food crops, and its production is strongly influenced by weather, especially droughts. As a result, the impact of drought on the production of winter wheat is associated with the food security of China. Simulations of future climate for scenarios A2 and A1B provided by GFDL-CM2, MPI_ECHAM5, MRI_CGCM2, NCAR_CCSM3, and UKMO_HADCM3 during 2001-2100 are used to project the influence of drought on winter wheat yields in North China. Winter wheat yields are simulated using the crop model WOFOST (WOrld FOod STudies). Future changes in temperature and precipitation are analyzed. Temperature is projected to increase by 3.9-5.5°C for scenario A2 and by 2.9-5.1°C for scenario A1B, with fairly large interannual variability. Mean precipitation during the growing season is projected to increase by 16.7 and 8.6 mm (10 yr)-1, with spring precipitation increasing by 9.3 and 4.8 mm (10 yr)-1 from 2012-2100 for scenarios A2 and A1B, respectively. For the next 10-30 years (2012-2040), neither the growing season precipitation nor the spring precipitation over North China is projected to increase by either scenario. Assuming constant winter wheat varieties and agricultural practices, the influence of drought induced by short rain on winter wheat yields in North China is simulated using the WOFOST crop model. The drought index is projected to decrease by 9.7% according to scenario A2 and by 10.3% according to scenario A1B during 2012-2100. This indicates that the drought influence on winter wheat yields may be relieved over that period by projected increases in rain and temperature as well as changes in the growth stage of winter wheat. However, drought may be more severe in the near future, as indicated by the results for the next 10-30 years.

  15. Foraging behavior of redheads (Aythya americana) wintering in Texas and Louisiana

    USGS Publications Warehouse

    Woodin, M.C.; Michot, T.C.

    2006-01-01

    Redheads, Aythya americana, concentrate in large numbers annually in traditional wintering areas along the western and northern rim of the Gulf of Mexico. Two of these areas are the Laguna Madre of Texas and Chandeleur Sound of Louisiana. We collected data on 54,340 activities from 103 redhead flocks in Texas and 51,650 activities from 57 redhead flocks in Louisiana. Males and females fed similarly, differing neither in levels of feeding (percent of all birds in flock that were feeding) (p>0.90) nor in percentages of birds feeding by diving, tipping, dipping, or gleaning from the surface (p>0.10). The foraging level of redheads in the upper Laguna Madre region was relatively constant throughout two winters. Foraging of redheads in early winter in Louisiana was significantly greater than redhead foraging in the upper Laguna Madre, but by late winter, foraging by redheads in Louisiana had declined to the same level as that shown by redheads foraging in the upper Laguna Madre. The overall foraging level of redheads from Chandeleur Sound was greater (41%) than that of redheads in the upper Laguna Madre (26%), yet it was quite similar to the 46% foraging level reported for redheads from the lower Laguna Madre. Redheads in the upper Laguna Madre region of Texas fed more by diving than did those in the Chandeleur Sound and the lower Laguna Madre. Diving increased in frequency in late winter. Greater reliance by redheads on diving in January and February indicates that the birds altered their foraging to feed in deeper water, suggesting that the large concentrations of redheads staging at this time for spring migration may have displaced some birds to alternative foraging sites. Our results imply that the most likely period for food resources to become limiting for wintering redheads is when they are staging in late winter. ?? Springer 2006.

  16. Environmental and physiological influences to isotopic ratios of N and protein status in a montane ungulate in winter

    USGS Publications Warehouse

    Gustine, David D.; Barboza, Perry S.; Adams, Layne G.; Wolf, Nathan B.

    2014-01-01

    Winter severity can influence large herbivore populations through a reduction in maternal proteins available for reproduction. Nitrogen (N) isotopes in blood fractions can be used to track the use of body proteins in northern and montane ungulates. We studied 113 adult female caribou for 13 years throughout a series of severe winters that reduced population size and offspring mass. After these severe winters, offspring mass increased but the size of the population remained low. We devised a conceptual model for routing of isotopic N in blood in the context of the severe environmental conditions experienced by this population. We measured ?15N in three blood fractions and predicted the relative mobilization of dietary and body proteins. The ?15N of the body protein pool varied by 4‰ and 46% of the variance was associated with year. Annual variation in ?15N of body protein likely reflected the fall/early winter diet and winter locations, yet 15% of the isotopic variation in amino acid N was due to body proteins. Consistent isotopic differences among blood N pools indicated that animals tolerated fluxes in diet and body stores. Conservation of body protein in caribou is the result of active exchange among diet and body N pools. Adult females were robust to historically severe winter conditions and prioritized body condition and survival over early investment in offspring. For a vagile ungulate residing at low densities in a predator-rich environment, protein restrictions in winter may not be the primary limiting factor for reproduction.

  17. Seasonal habitat selection by lake trout (Salvelinus namaycush) in a small Canadian shield lake: Constraints imposed by winter conditions

    USGS Publications Warehouse

    Blanchfield, P.J.; Tate, L.S.; Plumb, J.M.; Acolas, M.-L.; Beaty, K.G.

    2009-01-01

    The need for cold, well-oxygenated waters significantly reduces the habitat available for lake trout (Salvelinus namaycush) during stratification of small temperate lakes. We examined the spatial and pelagic distribution of lake trout over two consecutive summers and winters and tested whether winter increased habitat availability and access to littoral regions in a boreal shield lake in which pelagic prey fish are absent. In winter, lake trout had a narrowly defined pelagic distribution that was skewed to the upper 3 m of the water column and spatially situated in the central region of the lake. Individual core areas of use (50% Kernel utilization distributions) in winter were much reduced (75%) and spatially non-overlapping compared to summer areas, but activity levels were similar between seasons. Winter habitat selection is in contrast to observations from the stratified season, when lake trout were consistently located in much deeper waters (>6 m) and widely distributed throughout the lake. Winter distribution of lake trout appeared to be strongly influenced by ambient light levels; snow depth and day length accounted for up to 69% of the variation in daily median fish depth. More restricted habitat use during winter than summer was in contrast to our original prediction and illustrates that a different suite of factors influence lake trout distribution between these seasons. ?? Springer Science+Business Media B.V. 2009.

  18. Environmental and Physiological Influences to Isotopic Ratios of N and Protein Status in a Montane Ungulate in Winter

    PubMed Central

    Gustine, David D.; Barboza, Perry S.; Adams, Layne G.; Wolf, Nathan B.

    2014-01-01

    Winter severity can influence large herbivore populations through a reduction in maternal proteins available for reproduction. Nitrogen (N) isotopes in blood fractions can be used to track the use of body proteins in northern and montane ungulates. We studied 113 adult female caribou for 13 years throughout a series of severe winters that reduced population size and offspring mass. After these severe winters, offspring mass increased but the size of the population remained low. We devised a conceptual model for routing of isotopic N in blood in the context of the severe environmental conditions experienced by this population. We measured ?15N in three blood fractions and predicted the relative mobilization of dietary and body proteins. The ? 15N of the body protein pool varied by 4‰ and 46% of the variance was associated with year. Annual variation in ?15N of body protein likely reflected the fall/early winter diet and winter locations, yet 15% of the isotopic variation in amino acid N was due to body proteins. Consistent isotopic differences among blood N pools indicated that animals tolerated fluxes in diet and body stores. Conservation of body protein in caribou is the result of active exchange among diet and body N pools. Adult females were robust to historically severe winter conditions and prioritized body condition and survival over early investment in offspring. For a vagile ungulate residing at low densities in a predator-rich environment, protein restrictions in winter may not be the primary limiting factor for reproduction. PMID:25102057

  19. Environmental and physiological influences to isotopic ratios of N and protein status in a Montane ungulate in winter.

    PubMed

    Gustine, David D; Barboza, Perry S; Adams, Layne G; Wolf, Nathan B

    2014-01-01

    Winter severity can influence large herbivore populations through a reduction in maternal proteins available for reproduction. Nitrogen (N) isotopes in blood fractions can be used to track the use of body proteins in northern and montane ungulates. We studied 113 adult female caribou for 13 years throughout a series of severe winters that reduced population size and offspring mass. After these severe winters, offspring mass increased but the size of the population remained low. We devised a conceptual model for routing of isotopic N in blood in the context of the severe environmental conditions experienced by this population. We measured ?15N in three blood fractions and predicted the relative mobilization of dietary and body proteins. The ? 15N of the body protein pool varied by 4‰ and 46% of the variance was associated with year. Annual variation in ?15N of body protein likely reflected the fall/early winter diet and winter locations, yet 15% of the isotopic variation in amino acid N was due to body proteins. Consistent isotopic differences among blood N pools indicated that animals tolerated fluxes in diet and body stores. Conservation of body protein in caribou is the result of active exchange among diet and body N pools. Adult females were robust to historically severe winter conditions and prioritized body condition and survival over early investment in offspring. For a vagile ungulate residing at low densities in a predator-rich environment, protein restrictions in winter may not be the primary limiting factor for reproduction. PMID:25102057

  20. Effects of As on As uptake, speciation, and nutrient uptake by winter wheat (Triticum aestivum L.) under hydroponic conditions.

    PubMed

    Liu, Quanji; Hu, Chengxiao; Tan, Qiling; Sun, Xuecheng; Su, Jingjun; Liang, Yuexiang

    2008-01-01

    A hydroponic experiment was conducted to investigate the effects of arsenic (As) stress on growth, nutrition and As uptake, and speciation in shoots and roots of winter wheat (Triticum aestivum L.). Winter wheat has high tolerance to As. Most As is accumulated in the roots, and an As concentration of 4,421 mg/kg was observed at a solution concentration of 20 mg/L As. Arsenic concentrations in roots were approximately 40-100 times greater than those in shoots. Arsenic in winter wheat roots and shoots occurred as both As3+ and As5+ species, although As3+ was the main species in winter wheat tissues. Arsenic significantly decreased the biomass of winter wheat shoots and roots and affected absorption and transport of micro- and macro-elements in winter wheat tissue. Arsenic treatment significantly increased the concentrations of total Magnesium (Mg) and calcium (Ca) in shoots and enhanced the transport of Mg and Ca from roots to shoots but decreased potassium (K), nitrogen (N), and phosphorus (P) concentrations in both shoots and roots, particularly the concentration of P. Concentrations of iron, copper, and zinc in winter wheat shoots were negatively related to As rates, with correlation coefficients (R2) of 0.93, 0.94, and 0.97, respectively. PMID:18595400

  1. Supercooling and Freezing in Winter Dormant Animals

    NSDL National Science Digital Library

    William D. Schmid (University of Minnesota; )

    2008-04-11

    Winter dormant organisms, both plants and animals, have two general categories of adaptation for survival of exposure to cold climate stress. They can resist the formation of internal ice by supercooling through the production of antifreeze compounds; or, they can tolerate internal ice by addition of cryoprotectant biochemicals to their body fluids. In the latter case, nucleator chemicals may be produced to promote the formation of ice in extracellular fluids. We will use techniques to measure supercooling points of a winter dormant animal, the goldenrod gallfly, and to evaluate its seasonal production of cryoprotectant chemicals.

  2. Distribution of alewives in southeastern Lake Ontario in autumn and winter: a clue to winter mortalities

    USGS Publications Warehouse

    Bergstedt, Roger A.; O'Gorman, Robert

    1989-01-01

    Alewives Alosa pseudoharengus in the Great Lakes are thought to avoid extreme cold in winter by moving to deep water where the temperature is usually highest because of inverse thermal stratification. Information collected in Lake Ontario during autumn and winter 1981-1984 with an echo sounder and bottom and midwater trawls indicated that many alewives remained at depths above 110 m, regardless of water temperature. Alewives in the Great Lakes that did not descend to greater depths would be exposed to potentially lethal temperatures during cold winters.

  3. Winter CO2 and CH4 fluxes along a trans-Alaska pipeline during three winters

    Microsoft Academic Search

    Y. Kim; H. Enomoto; S. Kimura; G. Kadosaki

    2007-01-01

    This research was carried out to estimate the winter fluxes of CO2 and CH4 using the static chamber and the concentration profile methods along a trans-Alaska pipeline during three winters of 2004\\/5, 2005\\/6, and 2006\\/7. The 3-year averaged winter fluxes of CO2 and CH4 in taiga and tundra were 0.60±0.03 (SE; standard error) and 0.39±0.04 gCO2-C\\/m2\\/d, and 2.62±0.31 and 2.60±0.27

  4. CONTROLLING CHEATGRASS IN WINTER RANGE TO RESTORE HABITAT AND ENDEMIC FIRE

    Microsoft Academic Search

    JOSEPH G. VOLLMER; JENNIFER L. VOLLMER; RYAN AMUNDSON

    Cheatgrass (Bromus spp.), an introduced, invasive, annual grass of the Western rangelands, increases both fire frequency and intensity, competes with native species for water, space and nutrients, and is a primary cause for loss of habitat quality on elk and deer winter ranges. Studies indicate that rangeland with a 5% cheatgrass composition can become dominated by cheatgrass after a fire.

  5. Commitment and Compassion: Boston's Comprehensive Policy for the Homeless. Winter Report, December 1989.

    ERIC Educational Resources Information Center

    Emergency Shelter Commission, Boston, MA.

    The people of Boston made a commitment that no homeless person will be denied a bed, a meal, quality health care, and transportation to shelter during the winter of 1989-90. This commitment was difficult to fulfill due to a decline in services for the mentally ill, federal housing cutbacks, and an increase in the number of families living in…

  6. A Centralized Regional Database for Winter Cover Crops in Annual Cropping Systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Winter cover crops have the potential to reduce erosion, minimize losses of nitrogen and phosphorus, and increase soil carbon in annual cropping systems in the Midwest. Public support, however, for incentives to farmers to adopt cover crops is minimal. Therefore, development of location-specific rec...

  7. Effects of weather on daily body mass regulation in wintering dunlin

    Microsoft Academic Search

    John P. Kelly; Nils Warnock; Gary W. Page; Wesley W. Weathers

    We investigated the influence of changes in weather associated with winter storms on mass balance, activity and food consumption in captive dunlin (Calidris alpina) held in outdoor aviaries, and compared the aviary results with weather-related body mass differences in free-living dunlin collected at Bolinas Lagoon, California. Captive birds fed ad libitum increased their body mass at higher wind speeds and

  8. SRS Bulletin -Volume 7, No. 3 -Winter 2001 69 Modeling the Effects of Sleep Debt

    E-print Network

    Pennsylvania, University of

    SRS Bulletin - Volume 7, No. 3 - Winter 2001 69 Modeling the Effects of Sleep Debt of Medicine. Division of Sleep and Chronobiology, Department of Psychiatry, Unit for Experimental Psychiatry and desire for wakefulness at all hours of the day steadily increases. However, two fundamental neurobiologi

  9. Winter foraging by muskoxen: a hierarchical approach to patch residence time and cratering behaviour

    Microsoft Academic Search

    J. A. Schaefer; F. Messier

    1995-01-01

    We examined the temporal and spatial patterns of feeding behaviours of muskoxen during winter in the High Arctic. Pawing motions (to uncover forages beneath snow cover) were strongly aggregated into temporal bouts. Similarly, feeding stations (areas exploitable without motion of the forelegs) were aggregated into spatial patches. Muskoxen responded to greater snow accumulation at feeding sites by increasing the rates

  10. Fertilizer Facts: February 1993 Number 3 Winter Wheat Response to Chloride Fertilizers

    E-print Network

    Lawrence, Rick L.

    Engel Assoc. Prof., Soil Fertility/Plant Nutrition Land Resources and Environmental Sciences Dept to ensure adequate nutrition of these nutrients. Chloride significantly increased winter wheat grain yield.00 per bushel. Largest yield responses to 0 occurred at sites 2 and 6. Yield potential and growing season

  11. Rural Inhabitant Perceptions of Sandhill Cranes in Wintering Areas of Northern Mexico

    Microsoft Academic Search

    Ingrid Barceló; Juan Carlos Guzmán-Aranda; Felipe Chávez-Ramírez; Larkin Andrew Powell

    2012-01-01

    Trends in the mid-continent population of sandhill cranes (Grus canadensis) indicate that the species is increasing. A large proportion of this population winters in northern Mexico where possible conflicts between local inhabitants and cranes can occur. We conducted interviews of 40 rural inhabitants living near wetlands used by cranes in three Mexican states. All interviewees had knowledge of cranes and

  12. Winter intensification and water mass evolution from yearlong current meters in the Northeast Water Polynya

    Microsoft Academic Search

    R. Topp; M. Johnson

    1997-01-01

    In the summer of 1992, four current meter moorings were deployed in and later retrieved from the Northeast Water (NEW) polynya on the East Greenland Shelf by the USCGC Polar Sea. The moorings provided hourly temperature, salinity and current data for approximately one year. In the NEW, the circulation intensified and steadiness increased during winter. This intensification was most readily

  13. THE VALUE OF LUPINUS ALBUS L. CV. AU HOMER AS A WINTER COVER CROP FOR COTTON

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Successful cotton (Gossypium hirsutum L.) management in the southeastern USA with conservation tillage requires the utilization of winter cover crops to increase organic matter in the top 5 cm of the soil. The objective of our research was to test the newly-developed bitter white lupin cv. `AU Home...

  14. The winter anomaly in ionospheric absorption (with special reference to the results obtained in Spain)

    Microsoft Academic Search

    W. Dieminger

    1983-01-01

    The investigation of the winter anomaly since its discovery in 1937 is reviewed. The role played by three Spanish stations to monitor the temporal development of the ionospheric absorption over long periods is discussed. The present state of knowledge is summarized, stating that radio wave absorption changes are caused by increased electron density in the altitude range between 75 and

  15. Interaction between Macroinvertebrate Abundance and Habitat Use by Diving Ducks during Winter on Northeastern Lake Ontario

    Microsoft Academic Search

    Michael L. Schummer; Scott A. Petrie; Robert C. Bailey

    2008-01-01

    Although numbers of buffleheads (Bucephala albeola), common goldeneyes (Bucephala clangula) and long-tailed ducks (Clangula hyemalis) over-wintering on Lake Ontario have increased substantially over the past two decades, factors influencing habitat use and the potential for competition have not been investigated. The purpose of this study was to determine the relationship between prey availability and community structure of diving ducks during

  16. Reference: Biol. Brr//. 191: 92-100. (August, 1996) The Economy of Winter: Phenotypic Plasticity in

    E-print Network

    Jacobs, Lucia

    of resources. The cost of foraging increases dra- matically for temperate-zone animals during the winter. Two, a fore- brain structure used by birds and mammals to map spa- tial distributions of resources. Small,und a time to everypurpose under the heaven. -Ecclesiustes, 3.1 Behavior and neural structure evolve

  17. Influence of Mowing Artemisia tridentata ssp. wyomingensis on Winter Habitat for Wildlife

    Microsoft Academic Search

    Kirk W. Davies; Jonathan D. Bates; Dustin D. Johnson; Aleta M. Nafus

    2009-01-01

    Mowing is commonly implemented to Artemisia tridentata ssp. wyomingensis (Beetle & A. Young) S.L. Welsh (Wyoming big sagebrush) plant communities to improve wildlife habitat, increase forage production for livestock, and create fuel breaks for fire suppression. However, information detailing the influence of mowing on winter habitat for wildlife is lacking. This information is crucial because many wildlife species depended on

  18. The Interrelationships of Winter Wheat Cultivars, Crop Density and Competition of Naturally Occurring Weed Flora

    Microsoft Academic Search

    N. E. Korres; R. J. Froud-Williams

    2004-01-01

    The effects of intraspecific and interspecific competition on a wide range of winter wheat cultivars were investigated in two consecutive split plot field experiments. Significant reductions of grain yield at greatly reduced seed rates were observed in the first experiment, whereas increasing crop density up to 380 plants m in the second experiment failed to produce a significant yield response

  19. WINTER 2012 FOR ALUMNI AND FRIENDS OF THE UNIVERSITY

    E-print Network

    ILLUSTRATION BY MICHAEL GLENWOOD. 168 14 #12;FURMAN | WINTER 2012 32 FURMAN | WINTER 2012 The Outtakes of the South's best-known journalists, including Henry Grady and Ralph McGill. Here also are the papers

  20. GOES Satellite Movie of 2014 Winter Storms - Duration: 82 seconds.

    NASA Video Gallery

    This new animation of NOAA's GOES-East satellite imagery shows the movement of winter storms from January 1 to March 24 making for a snowier-than-normal winter along the U.S. East coast and Midwest...

  1. Sources and contributions of wood smoke during winter in London

    NASA Astrophysics Data System (ADS)

    Crilley, Leigh; Bloss, William; Yin, Jianxin; Beddows, David; Harrison, Roy; Zotter, Peter; Prevot, Andre; Green, David

    2014-05-01

    Determining the contribution of wood smoke in large urban centres such as London is becoming increasingly important with the changing nature of domestic heating partly due to the installation of biomass burning heaters to meet renewable energy targets imposed by the EU and also a rise in so-called recreational burning for aesthetic reasons (Fuller et al., 2013). Recent work in large urban centres (London, Paris and Berlin) has demonstrated an increase in the contribution of wood smoke to ambient particles during winter that can at times exceed traffic emissions. In Europe, biomass burning has been identified as a major cause of exceedances of European air quality limits during winter (Fuller et al., 2013). In light of the changing nature of emissions in urban areas there is a need for on-going measurements to assess the impact of biomass burning in cities like London. Therefore we aimed to determine quantitatively the contribution of biomass burning in London and surrounding rural areas. We also aimed to determine whether local emissions or regional sources were the main source of biomass burning in London. Sources of wood smoke during winter in London were investigated at an urban background site (North Kensington) and two surrounding rural sites (Harwell and Detling) by analysing selected wood smoke chemical tracers. Concentrations of levoglucosan, elemental carbon (EC), organic carbon (OC) and K+ were generally well correlated, indicating a similar source of these species at the three sites. Based on the conversion factor for levoglucosan, mean wood smoke mass at Detling, North Kensington and Harwell was 0.78, 0.87 and 1.0 µg m-3, respectively. At all the sites, biomass burning was found to be a source of OC and EC, with the largest source of OC and EC found to be secondary organic aerosols and traffic emissions, respectively. Peaks in levoglucosan concentrations at the sites were observed to coincide with low ambient temperature, suggesting domestic heating as a contributing source in London. Overall, the source of biomass burning in London was likely a background regional source from mainland Europe overlaid by high contributions from local domestic burning emissions. This could have implications when considering future control strategies during winter. References Fuller, G.W., Sciare, J., Lutz, M., Moukhtar, S., Wagener, S., 2013. New Directions: Time to tackle urban wood burning? Atmospheric Environment 68, 295-296.

  2. Winter severity predicts the timing of host shifts in the mosquito Culex erraticus

    PubMed Central

    Burkett-Cadena, Nathan D.; Hassan, Hassan K.; Eubanks, Micky D.; Cupp, Eddie W.; Unnasch, Thomas R.

    2012-01-01

    In temperate regions, seasonal epidemics of many mosquito-borne viruses are triggered when mosquito populations shift from feeding on avian to mammalian hosts. We investigated effects of temperature on the timing of bird-to-mammal shifts using an 8 year dataset of blood-meals from a mosquito (Culex erraticus) in Alabama, USA. As expected, Cx. erraticus shifted from avian to mammalian hosts each year. The timing of the shift, however, varied considerably among years. Harshness of the preceding winter (chill accumulation) explained 93 per cent of the variation in the timing of bird-to-mammal shifts, with shifts occurring later in years following harsher winters. We hypothesize that winter temperatures drive the timing of bird-to-mammal shifts through effects on host reproductive phenology. Because mosquitoes target birds during the nesting season, and bird nesting occurs later in years following colder winters, later nesting dates result in a concomitant delay in the timing of bird-to-mammal host shifts. Global increases in winter temperatures could cause significant changes in the timing of seasonal host shifts by mosquitoes, with prolonged periods of epidemic transmission of mosquito-borne diseases. PMID:22399787

  3. A new circulation index to describe variations in winter temperature in Southwest China

    NASA Astrophysics Data System (ADS)

    Shen, Lelin; Chen, Longxun; Jin, Qihua; Zhu, Yanfeng

    2015-04-01

    A new circulation index ( I SW) that can realistically describe winter temperature variations over Southwest China is defined based on analysis of the NCEP/NCAR reanalysis data (version 1) and the observations at 585 stations in China. The study period is from January 1961 to February 2011. The relationship between I SW and general circulation patterns in East Asia is also analyzed. Results show that I SW successfully captures the variations in winter temperature over Southwest China. High I SW values correspond to the intensified Mongolian high, the weakened Aleutian low, increases in the strength of the Middle East westerly jet stream over the south of the Tibetan Plateau (TP), and decreases in the strength of the subtropical westerly jet over the north of the TP. Meanwhile, the East Asian trough deepens and extends southwestward, making it easier for the cold air mass from the north to intrude Southwest China along the trough. These circulation patterns lead to a decrease in winter temperature over Southwest China (and vice versa). In addition to the East Asian winter monsoon, the two westerly jets that dominate the upper level circulation over East Asia also exert important influences on winter temperature in Southwest China, especially the Middle East westerly jet to the south of the TP.

  4. ELF-magnetic flux densities measured in a city environment in summer and winter.

    PubMed

    Straume, Aksel; Johnsson, Anders; Oftedal, Gunnhild

    2008-01-01

    Epidemiological studies have indicated a connection between extremely low frequency magnetic flux densities above 0.4 microT (time weighted average) and childhood leukemia risks. This conclusion is based mainly on indoor exposure measurements. We therefore regarded it important to map outdoor magnetic flux densities in public areas in Trondheim, Norway. Because of seasonal power consumption variations, the fields were measured during both summer and winter. Magnetic flux density was mapped 1.0 m above the ground along 17 km of pavements in downtown Trondheim. The spectrum was measured at some spots and the magnetic flux density emanated mainly from the power frequency of 50 Hz. In summer less than 4% of the streets showed values exceeding 0.4 microT, increasing to 29% and 34% on cold and on snowy winter days, respectively. The average levels were 0.13 microT (summer), 0.85 microT (winter, cold), and 0.90 microT (winter, snow), with the highest recorded value of 37 microT. High spot measurements were usually encountered above underground transformer substations. In winter electric heating of pavements also gave rise to relatively high flux densities. There was no indication that the ICNIRP basic restriction was exceeded. It would be of interest to map the flux density situation in other cities and towns with a cold climate. PMID:17786926

  5. Waterfowl density on agricultural fields managed to retain water in winter

    USGS Publications Warehouse

    Twedt, D.J.; Nelms, C.O.

    1999-01-01

    Managed water on private and public land provides habitat for wintering waterfowl in the Mississippi Valley, where flood control projects have reduced the area of natural flooding. We compared waterfowl densities on rice, soybean, and moist-soil fields under cooperative agreements to retain water from 1 November through 28 February in Arkansas and Mississippi and assessed temporal changes in waterfowl density during winter in 1991-1992 and 1992-1993. Fields flooded earlier in Arkansas, but retained water later in Mississippi. Over winter, waterfowl densities decreased in Arkansas and increased in Mississippi. Densities of waterfowl, including mallard (Anas platyrhynchos), the most abundant species observed, were greatest on moist-soil fields. However, soybean fields had the greatest densities of northern shoveler (Spatula clypeata).

  6. Carbon dioxide gas exchange of cembran pine (Pinus cembra) at the alpine timberline during winter.

    PubMed

    Wieser, G

    1997-07-01

    Winter CO(2) gas exchange of the last three flushes of cembran pine (Pinus cembra L.) was studied under ambient conditions at the alpine timberline, an ecotone with strong seasonal changes in climate. During the coldest months of the year, December to March, gas exchange was almost completely suppressed and even the highest irradiances and temperatures did not cause a significant increase in net photosynthesis compared to spring and fall. In general, daily CO(2) balance was negative between December and March except during extended warm periods in late winter. However, because twig respiration was also reduced to a minimum during the December-March period, daily carbon losses were minimal. Total measured carbon loss during the winter months was small, equalling the photosynthetic production of one to two warm days in spring or summer when average air temperature was above 6 degrees C. PMID:14759840

  7. Serious BTEX pollution in rural area of the North China Plain during winter season.

    PubMed

    Liu, Kankan; Zhang, Chenglong; Cheng, Ye; Liu, Chengtang; Zhang, Hongxing; Zhang, Gen; Sun, Xu; Mu, Yujing

    2015-04-01

    Atmospheric BTEX compounds (benzene, toluene, ethylbenzene and xylenes) in a rural site of the North China Plain (NCP) were preliminarily investigated in winter, and the outdoor concentrations (25.8-236.0?g/m(3)) were found to be much higher than those reported in urban regions. The pollution of BTEX inside a farmer's house was even more serious, with combined concentrations of 254.5-1552.9?g/m(3). Based on the ratio of benzene to toluene (1.17±0.34) measured, the serious BTEX pollution in the rural site was mainly ascribed to domestic coal combustion for heating during the winter season. With the enhancement of farmers' incomes in recent years, coal consumption by farmers in the NCP is rapidly increasing to keep their houses warm, and hence the serious air pollution in rural areas of the NCP during winter, including BTEX, should be paid great attention. PMID:25872726

  8. The relationship of blue crab abundance to winter mortality of Whooping Cranes

    USGS Publications Warehouse

    Pugesek, Bruce H.; Baldwin, Michael J.; Stehn, Thomas

    2013-01-01

    We sampled blue crab (Callinectes sapidus) numbers in marshes on the Aransas National Wildlife Refuge, Texas from 1998-2006, while simultaneously censusing the wintering population of Whooping Cranes (Grus americana) on the refuge and surrounding habitats. This was done to determine whether mortality of wintering Whooping Cranes was related to the availability of this food source. Yearly variation in crab numbers was high, ranging from a low of 0.1 crabs to a high of 3.4 crabs per 100-m transect section. Significant non-linear increases in both juvenile and adult mortality in relation to decreasing crab abundance was observed. Results suggest that some threshold of crab abundance exists in which Whooping Cranes have higher survival on their wintering grounds.

  9. Manure Storage Winter Capacity Planning Level Guidance January 1, 2013

    E-print Network

    Guiltinan, Mark

    1 Manure Storage Winter Capacity Planning Level Guidance January 1, 2013 The guidance outlined in this document is to be used to determine the Manure Storage Winter Capacity Planning Level for CAFO operations must be documented in the NMP Standard Format. For determining the manure storage winter capacity

  10. Livable Winter Cities--Leisure Attitudes and Activities.

    ERIC Educational Resources Information Center

    Neal, Larry; Coles, Roger, Ed.

    1989-01-01

    The nine articles included in this feature emphasize how leisure, recreation, health and physical activities make winter cities more livable. Specific topics include techniques for teaching about cold weather safety and cold related injuries, Arctic Winter Games, and results of a study on winter recreation in large North American communities. (IAH)

  11. Greeley Haven Mars rover to spend winter at

    E-print Network

    Rhoads, James

    Greeley Haven Mars rover to spend winter at `Greeley Haven,' named for late ASU geologist Ronald satellite launches life in new directions [9] Greeley Haven Mars rover to spend winter at `Greeley Haven Rover Opportunity is spending its fifth Martian winter, an outcrop informally named "Greeley Haven

  12. Tillage requirements for vegetables following winter annual grazing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In Alabama, over 400,000 ac of winter annuals are grazed prior to planting summer row crops. Previous research indicates that cattle grazed on ryegrass (Lolium multiflorum L.) pastures over the winter months in Alabama can be profitable, but winter grazing creates excessive compaction, which advers...

  13. New York City College of Technology WINTER 2014 Academic Calendar

    E-print Network

    Rosen, Jay

    New York City College of Technology WINTER 2014 Academic Calendar Dates Days December 31 Tuesday COLLEGE IS CLOSED January 1 Wednesday COLLEGE IS CLOSED Last day to drop Winter Session classes with 100% refund January 2 Thursday Winter Session begins January 3 Friday Last day to drop with 50% tuition refund

  14. QTL MAPPING OF WINTER HARDINESS GENES IN LENTIL

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lentil (Lens culinaris L.) germplasm with sufficient winter hardiness to survive most winters in cold northern areas is available; however, the use of that germplasm in breeding programs is hampered by variable winter conditions that make field evaluations needed for effective breeding and selection...

  15. SURVIVAL, EMIGRATION, AND WINTER POPULATION STRUCTURE OF HARLEQUIN DUCKS

    Microsoft Academic Search

    Fred Cooke; Gregory J. Robertson; Cyndi M. Smith; R. Ian Goudie; W. Sean Boyd

    2000-01-01

    A population of individually marked Harlequin Ducks (Histrionicus histrion- icus) at White Rock, British Columbia, Canada was examined to measure the degree of population differentiation among birds which pair during the winter months. This required an understanding of the patterns of emigration among wintering sites in different segments of the population. Some juveniles arrived at the wintering grounds accompanied by

  16. THE STATUS OF WINTERING GOLDEN-CHEEKED WARBLERS IN NICARAGUA

    Microsoft Academic Search

    DAVID I. KING; EDGARD HERRERA; SANDRA HERNANDEZ; CAROL A. LIVELY; DAVID W. MEHLMAN; JOHN H. RAPPOLE; DANA ROTH

    The Golden-cheeked Warbler (Dendroica chrysoparia) is an endangered Neotropical-Nearctic migrant that winters in Mexico and Central America. Although previous studies delineated the winter range of this species in Mexico, Guatemala and Honduras and established that wintering Golden-cheeked Warblers are closely associated with montane forest pine-oak forest with abundant narrow-leaved \\

  17. A scale analysis of the D region winter anomaly

    Microsoft Academic Search

    D. Offermann; H. G. K. Brueckelmann; J. J. Barnett; K. Labitzke; K. M. Torkar; H. U. Widdel

    1982-01-01

    A scale analysis, i.e., an estimation of typical values of important atmospheric and ionospheric parameters and time scales is performed for the meteorological type of winter anomaly at medium latitudes (40 deg N). An interpretative model of the winter anomaly is developed by a correlation analysis on the basis of data obtained from the Western European Winter Anomaly Campaign 1975\\/76

  18. a Climatology of Extreme Minimum Winter Temperatures in Ohio

    Microsoft Academic Search

    Dennis Joe Edgell

    1992-01-01

    The Extreme Minimum Winter Temperature (EMWT) is the coldest temperature recorded each winter at a given weather station. This variable is a measure of winter temperature stress. Extreme cold influences the geographic distribution of plants, and is a prime control for the production of some valuable fruit crops grown in Ohio. EMWT values are often used to map plant hardiness

  19. Cold winters and the relation to atmospheric blocking

    E-print Network

    de Vries, Hylke

    Cold winters and the relation to atmospheric blocking Hylke de Vries De Bilt, 2011 | Technical report; TR-324 #12;#12;Cold winters and the relation to atmospheric blocking Versie 1.0 Datum 12 september 2011 Status Definitief #12;#12;COLD WINTERS AND THE RELATION TO ATMOSPHERIC BLOCKING HYLKE DE

  20. 33 CFR 401.92 - Wintering and laying-up.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 false Wintering and laying-up. 401.92 Section 401.92 Navigation...General § 401.92 Wintering and laying-up. No vessel shall winter within the Seaway or lay-up within the Seaway during the navigation...

  1. 33 CFR 401.92 - Wintering and lying-up.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Wintering and lying-up. 401.92 Section 401.92 Navigation...General § 401.92 Wintering and lying-up. No vessel shall winter within the Seaway or lie-up within the Seaway during the navigation...

  2. 33 CFR 401.92 - Wintering and lying-up.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 false Wintering and lying-up. 401.92 Section 401.92 Navigation...General § 401.92 Wintering and lying-up. No vessel shall winter within the Seaway or lie-up within the Seaway during the navigation...

  3. 33 CFR 401.92 - Wintering and lying-up.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 false Wintering and lying-up. 401.92 Section 401.92 Navigation...General § 401.92 Wintering and lying-up. No vessel shall winter within the Seaway or lie-up within the Seaway during the navigation...

  4. 33 CFR 401.92 - Wintering and laying-up.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Wintering and laying-up. 401.92 Section 401.92 Navigation...General § 401.92 Wintering and laying-up. No vessel shall winter within the Seaway or lay-up within the Seaway during the navigation...

  5. Cryopreservation of winter-dormant apple buds: I -Variation in recovery with cultivar and winter conditions.

    PubMed

    Vogiatzi, C; Grout, B W W; Wetten, A; Toldam-Andersen, T B

    2011-01-01

    The widely-adopted protocol for the cryopreservation of winter buds of fruit trees, such as Malus and Pyrus, was developed in a region with a continental climate, that provides relatively hard winters with a consequent effect on adaptive plant hardiness. In this study the protocol was evaluated in a typical maritime climate (eastern Denmark) where milder winters can be expected. The survival over two winters was evaluated, looking at variation between seasons and cultivars together with the progressive reduction in survival due to individual steps in the protocol. The study confirms that under such conditions significant variation in survival can be expected and that an extended period of imposed dehydration at -4 degree C is critical for bud survival. The occurrence of freezing events during this treatment suggests that cryodehydration may be involved, as well as evaporative water loss. To optimize the protocol for maritime environments, further investigation into the water status of the explants during cryopreservation is proposed. PMID:22020415

  6. WellcomeHISTORY Issue 54, winter 2014

    E-print Network

    Rambaut, Andrew

    WellcomeHISTORY Issue 54, winter 2014 BEAUTIFULLY HIDEOUS Pioneering plastic surgery in World War I #12;2 | Wellcome HISTORY Beautifully hideous Pioneering plastic surgery in World War I Jennifer', are the first pioneering examples of modern plastic surgery from World War I. Facial and head injuries were

  7. amagazineforalumniandfriendsoftheinstituteoftechnology|fall/winter2008 Undergraduate research

    E-print Network

    Minnesota, University of

    Editor Silva Young Contributors Richard Broderick Jayme Halbritter Patrick O'Leary Kermit Pattison Maxine the science of the small has a big impact on our everyday lives By riChArd BrodEriCk Research Rewards · 16 to protect proud college history while enhancing student learning By silvA yoUng fall/winter 2008-09 Invent

  8. Garden Master Classes Winter/Spring 2012

    E-print Network

    Holsinger, Kent

    1 Garden Master Classes Winter/Spring 2012 Revised January 25, 2012 #12;2 Advanced Master Gardener Certification Requirements Certified Master Gardeners may obtain Advanced Master Gardener certification by ful. The time ac- cumulates with the first AMG/Master Gardening class taken after completing the Master Gardener

  9. Deeper Snow Enhances Winter Respiration from Both

    E-print Network

    Grogan, Paul

    Deeper Snow Enhances Winter Respiration from Both Plant-associated and Bulk Soil Carbon Pools that respiration from each was sensitive to warmer soil temperatures. Furthermore, deepened snow resulted in cooler- associated microbial respiration) and respiration derived from carbon in the bulk soil organic matter pool

  10. Philosophy of Logic Fall 2002 -Winter 2003

    E-print Network

    Barrett, Jeffrey A.

    Philosophy of Logic Fall 2002 - Winter 2003 Our goal over these two quarters is to think through in later years. See Philosophy of Logic, chapte a series of possible positions on the nature of logical truth. We will focus on the most fundamental

  11. Registration of ‘Sprinter’ hard red winter wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    High grain protein concentration and stripe rust (caused by Puccinia striiformis Westend. f. sp. tritici Eriks.) resistance are important traits for hard red winter wheat (Triticum aestivum L.) cultivars produced in the Pacific Northwest region of the United States. The objective of this research wa...

  12. PSY 330: Thinking Winter Term, 2013

    E-print Network

    Lockery, Shawn

    PSY 330: Thinking Winter Term, 2013 Time/Place: 12-1:20pm, Tuesdays, and various forms of rational and irrational reasoning and belief systems." ~ UO such as thinking, reasoning, etc. But essentially, this course focuses on how we go about

  13. Sociality of grassland birds during winter

    Microsoft Academic Search

    Joseph A. Grzybowski

    1983-01-01

    Sociality of granivorous passerine birds occupying open grassland habitats of the southcentral United States was evaluated during winter in relation to habitat cover, seed density and bird density. Habitat height and habitat density, measures of exposure to potential predation, are associated with the major distinction of social pattern between the two granivore subgroups; sparrows, which tend to be more solitary,

  14. Registration of 'Eve' winter hulless barley

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ‘Eve’ (Reg. No. CV- PI 659067 ), a six-row winter hulless barley (Hordeum vulgare L.) developed and tested as VA01H-68 by the Virginia Agricultural Experiment Station was released in May 2007. Eve was derived from the cross SC860974 / VA94-42-13. Eve is widely adapted and provides producers with ...

  15. PSY 380: Psychology of Gender Winter 2012

    E-print Network

    Lockery, Shawn

    development, personality, interpersonal relationships), and special issues pertinent to gender, (ePSY 380: Psychology of Gender CRN 27363 Winter 2012 Tuesday & Thursday, 5:00 pm ­ 6:20 pm 112 common beliefs about gender, the relationship of gender to traditional issues in psychology (e.g., moral

  16. Winter Wheat Fertilization: Post Ammonium Nitrate

    Microsoft Academic Search

    R. Byron Irvine; Guy Lafond; Randy Kutcher

    Summary The potential for overwinter losses of nitrogen by denitrification and leaching have led to the recommendation that nitrogen fertilization of winter wheat be done using ammonium nitrate broadcast in the spring. However, spring broadcast application of urea can result in significant loss of nitrogen by volatilization and immobilization by surface residues. Since prilled ammonium nitrate is not available for

  17. winter 07/08 Call for Collaboration

    E-print Network

    Mottram, Nigel

    winter 07/08 Call for Collaboration Requests A novel design concept for the `Gecko con- trolled design concepts for the `gecko controlled flow liner' for body/device interfaces in the provision according specific design criteria? · Can we develop liner adhesion by mim- icking gecko adhesive

  18. Winter 2014 VM objects -virtual pages

    E-print Network

    Toronto, University of

    CSC 369 A3 Winter 2014 #12;Agenda VM objects - virtual pages Coremap - physical pages TLB - hardware that stores mappings between virtual and physical pages Page faults #12;A3 Implement paging by writing the following functions: lpage_fault --- handles a page fault lpage_evict --- evicts an lpage from

  19. CEE 453 Winter 2003 Prestressed Concrete Design

    E-print Network

    Eberhard, Marc O.

    (pre- and post-tensioning) 2. Materials Sec. 2.1-2.7 - desirable properities - steel - concrete 3CEE 453 Winter 2003 Prestressed Concrete Design Instructor: M.O. Eberhard Office: 233 More Hall have taken a class in reinforced concrete design (e.g., CEE 452 or CEE 511), but who have not yet taken

  20. DIELECTRIC SPECTROSCOPY OF HARD RED WINTER WHEAT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The dielectric properties (components of the complex permittivity relative to free space) of ground hard red winter wheat of 11 to 25 percent moisture content were determined by dielectric spectroscopy measurements with an open-ended coaxial-line probe and impedance analyzer over the frequency range...

  1. INTERCROPPING WINTER CEREAL GRAINS AND RED CLOVER

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Energy, economic, environmental, and pest issues are leading some crop producers to diversity beyond the corn/soybean rotation dominant in Iowa. Research by Iowa State University and the United States Department of Agriculture’s National Soil Tilth Laboratory indicates intercropping of winter cereal...

  2. Prevention of Winter Mould Growth in Housing

    Microsoft Academic Search

    Bin Su

    2006-01-01

    This paper reports on a study that researched the possibility of building passive designs to prevent mould growth in housing in humid and mild winter climatic zones without permanent thermal active controls. This study also investigated indoor relative humidity related to insulation, window cross ventilation, exhaust fan ventilation and temporary heating. The study found that for controlling mould growth on

  3. Frugivory by Wintering Hermit Thrush In Louisiana

    Microsoft Academic Search

    Cheryl M. Strong; David R. Brown; Philip C. Stouffer

    2005-01-01

    We investigated the role of fruit availability in the diet of wintering Catharus guttatus Pallas (Hermit Thrushes) in southeastern Louisiana. Most fecal samples contained fruit and arthropods (N = 126), while few samples contained only arthropods (N = 32). We observed 26 species of fruiting plants at our sites, and found nine in fecal samples. Ilex vomitoria (Yaupon, 52% of

  4. CBS Sportsline: The XVII Winter Olympic Games

    NSDL National Science Digital Library

    The 18th Winter Olympic Games will be held at Nagano, Japan from February 7 to February 22, 1998. CBS TV is the American network broadcasting the games and its site is highlighted by feature stories about each sport, a schedule of events, rules, and brief individual profiles.

  5. Registration of 'Windham' Winter Feed Pea.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Winter legumes offer a unique opportunity for producers to establish a legume crop in the fall and transfer a significant portion of field preparation to the fall avoiding undesirable field conditions in the spring, and yet maintain the benefits of including a legume in the crop rotation. ‘Windham’ ...

  6. MKTG451, Marketing Research Winter, 2014

    E-print Network

    Carter, John

    -1. The book has been ordered at the SU bookstore; but, I encourage you to shop on-line. You do not need on-line. Students view the lectures outside of class. Class time is spent reviewing the lectureMKTG451, Marketing Research Winter, 2014 draft 12.3 Professor: Carl Obermiller (Pigott 511, carlo

  7. 12 Winter 2012 ShiningaLight

    E-print Network

    Barthelat, Francois

    12 Winter 2012 ShiningaLight Food Poisoning on I N D E P T H Food-borne illnesses affect more than 12 million Canadians each year. Always unpleasant, sometimes fatal, bad food takes a huge toll in the Department of Food Science and Agricultural Chemistry have been exploring the molecular underpinnings of what

  8. Population Trends of Wintering Bats in Vermont

    Microsoft Academic Search

    Stephen C. Trombulak; Philip E. Higuera; Mark DesMeules

    2001-01-01

    We report the results of all readily available inventories of wintering bats in Vermont. Surveys at 23 hibernacula were compiled from the literature and unpublished data of numerous biologists and cavers. The earliest Vermont records date back to 1934. Only five hibernacula were systematically surveyed for more than 45 years. Despite data limitations, several trends have emerged. Since the 1930s,

  9. Winter in Northern Europe (WINE) Project

    NASA Technical Reports Server (NTRS)

    Vonzahn, U.

    1982-01-01

    The scientific aims, work plan, and organization of the Middle Atmosphere Program winter in northern Europe (MAP/WINE) are described. Proposed contributions to the MAP/WINE program from various countries are enumerated. Specific atmospheric parameters to be examined are listed along with the corresponding measurement technique.

  10. WINTER DIET OF FISHERS IN BRITISH COLUMBIA

    Microsoft Academic Search

    RICHARD DW EIR; ALTON SH ARESTAD

    We identified the stomach contents of fishers (Martes pennanti) collected during winter between 1989 and 1993 from throughout British Columbia. Eighteen types of mammalian and avian prey were found in 256 stomachs. The most commonly occurring species of prey were snowshoe hares (Lepus americanus), red squirrels (Tamiasciurus hudsonicus), and southern red- backed voles (Clethrionomys gapperi). The diets of fishers varied

  11. MEASURED WINTER PERFORMANCE OF STORM WINDOWS

    E-print Network

    MEASURED WINTER PERFORMANCE OF STORM WINDOWS J. H. Klems Windows and Daylighting Group, Building comparison measurements were made between various prime/storm window combinations and a well-weatherstripped, single-hung replacement window with a low-E selective glazing. Measurements were made using an accurate

  12. TERRITORIAL BEHAVIOR OF WINTERING RED HEADED WOODPECKERS

    Microsoft Academic Search

    LAWRENCE KILHAM

    ERRITORIES of Red-headed Woodpeckers (Melanerpes erythrocephalus) were studied near Seneca, Montgomery County, Maryland, where a win- ter population was attracted to pin oaks (Quercus palustris) growing near the Chesapeake and Ohio Canal and the Potomac River. These woodpeckers appeared in September, 1956, and left in May, 1957. Their breeding grounds were unknown. The winter territories were small, well-defined, and repre-

  13. STORAGE PROTEINS IN WINTER HONEY BEES

    Microsoft Academic Search

    G. W. Otis; D. E. Wheeler; N. Buck; H. R. Mattila

    2004-01-01

    Honey bee colonies in temperate climates begin brood rearing in late winter before floral resources are available. Protein required for brood rearing comes from pollen stored in combs as well as proteins stored internally in the bees' bodies. We studied the changes in amounts of several proteins that could serve as internal storage compounds in fall-emerging bees that contributed to

  14. IMPACT OF OZONE ON WINTER WHEAT YIELD

    EPA Science Inventory

    Wheat is one of the more important agricultural crops in the USA, and the major production areas may be subjected to potentially damaging concentrations of ozone (O3). Since no information was available regarding the O3 sensitivity of winter wheat cultivars grown in the Midwest, ...

  15. PPMCSA Presentation on Winter Distillate Outlook

    NSDL National Science Digital Library

    This presentation on the Winter Distillate Outlook was created for the PPMCSA Meeting and Trade Show of this year. It gives basic information and forecasts on the prices of a variety of energy sources through a collection of slides and accompanying notes.

  16. CEE 502 Winter 2008 Dynamics of Structures

    E-print Network

    Eberhard, Marc O.

    CEE 502 Winter 2008 1 Dynamics of Structures Instructor: M.O. Eberhard Office: 233 More Hall Phone of structural dynamics, as well as typical analytical and numerical methods. · to provide students with examples Outline Reading (Chopra) I. Introduction Ch. 1 - Role of Dynamic Analysis in Structural Engineering

  17. Sea Surface Temperatures and Australian Winter Rainfall

    Microsoft Academic Search

    Neville Nicholls

    1989-01-01

    A rotated principal component analysis of Australian winter (June-August) rainfall revealed two large-scale patterns of variation which together accounted for more than half of the total rainfall variance. The first pattern was a broadband stretching from the northwest to the southeast corners of the country. The second was centered in the eastern third of the continent. The two patterns were

  18. WINTER, 19a9 Academic quality

    E-print Network

    de Lijser, Peter

    - I WINTER, 19a9 Academic quality and accreditation: A case of good news and bad news? liThe good;-~----------------------------------------------------------~ T Accreditation The issue of specialized accreditation can be divisive on campuses. It has divided departments accreditation. On the following pages are articles of how one de- partment was seen by others to be holding its

  19. Hulless winter barley for ethanol production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hulless barley is viable feedstock alternative to corn for ethanol production in areas where small grains are produced. The first barley-based ethanol plant in the US is currently under construction by Osage BioEnergy LLC in Hopewell, VA. New hulless winter barley varieties developed by Virginia T...

  20. NEW INTERNSHIP FOR WINTER Interactive Ecology

    E-print Network

    Wilmers, Chris

    NEW INTERNSHIP FOR WINTER Interactive Ecology UC Santa Cruz Arboretum Internship Agency Sponsor: Brett Hall, Director of Collections and Conservation Interactive Ecology interns will work primarily, back pack tracker, GPS, google earth, etc). The Interactive Ecology internship will also explore, more

  1. Climate Ethics, Climate Justice Winter 2014

    E-print Network

    Climate Ethics, Climate Justice Winter 2014 ENVS 411: TR, 4:00 ­ 5:50, COL 142 Instructor: Tim Description: Given the stakes, climate change is perhaps the defining issue of our age. How we respond (or don are now claiming, is this primarily an issue of ethics and justice? The implications of climate change

  2. REGISTRATION OF 'NE422T' WINTER TRITICALE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    NE422T triticale (X.Triticosecale rimpaui Wittm.) was developed cooperatively by the Nebraska Agricultural Experiment Station and the USDA-ARS. NE422T is an F3-derived F4 line that was released primarily for its superior forage production in rainfed winter cereal production systems in the central G...

  3. Northern Winter Stationary Waves: Theory and Modeling

    Microsoft Academic Search

    Isaac M. Held; Mingfang Ting; Hailan Wang

    2002-01-01

    A review is provided of stationary wave theory, the theory for the deviations from zonal symmetry of the climate. To help focus the discussion the authors concentrate exclusively on northern winter. Several theoretical issues, including the external Rossby wave dispersion relation and vertical structure, critical latitude absorption, the nonlinear response to orography, and the interaction of forced wave trains with

  4. ``Winter'' aggregations, colony cycle, and seasonal phenotypic change in the paper wasp Polistes versicolor in subtropical Brazil

    NASA Astrophysics Data System (ADS)

    Gobbi, Nivar; Noll, Fernando B.; Penna, Marcelo A. H.

    2006-10-01

    Social wasps from temperate zones have clear annual colony cycles, and the young queens hibernate during winter. In the subtropics, the only previously reported evidence for the existence of “hibernation” is the facultative winter aggregations of females during harsh climate conditions. As in temperate-zone species analyzed so far, we show in this study that in the paper wasp, Polistes versicolor, a subtropical species, body size increases as an unfavorable season approaches. Our morphological studies indicate that larger females come from winter aggregations—that is, they are new queens. Multivariate analyses indicate that size is the only variable analyzed that shows a relationship to the differences. Given the absence of a harsh climate, we suggest that the occurrence of winter aggregations in tropical P. versicolor functions to allow some females to wait for better environmental conditions to start a new nest, rather than all being obliged to start a new nest as soon as they emerge.

  5. Differences in responses of summer and winter spinach to elevated UV-B at varying soil NPK levels.

    PubMed

    Singh, Suruchi; Agrawal, Madhoolika; Agrawal, S B

    2014-05-01

    Seasonal variations in response of spinach to elevated ultraviolet-B (UV-B) during summer and winter were assessed with respect to growth, biomass, yield, NPK uptake and NPK use efficiencies at varying NPK levels. The nutrient amendments were recommended NPK (RNPK) and 1.5 times recommended NPK (1.5 RNPK). Season significantly affected the measured parameters except the number of leaves. Under ambient UV-B, the growth performance of summer spinach was better in both the NPK levels, higher being at 1.5 RNPK leading to higher nutrient uptake. However, more reduction in biomass under elevated UV-B in 1.5 RNPK was recorded during summer, while during winter in RNPK. Reduction in biomass under elevated UV-B was accompanied by the modification in its partitioning with more biomass allocation to root during summer compared to winter at both the NPK levels. NPK uptake was higher in summer, while NPK use efficiencies were higher during winter. At higher than recommended NPK level, better NPK use efficiencies were displayed during both the seasons. Increased NPK supply during winter enabled spinach to capitalize light more efficiently and hence increased biomass accumulation. Strategies for surviving elevated UV-B in winter differ from those that provided protection from the same stress when it occurs in summer. PMID:24474564

  6. Effect of enhanced UV-B radiation combined with other climate stressors on winter wheat

    NASA Astrophysics Data System (ADS)

    Gao, Wei; Zheng, Youfei; Slusser, James R.; Grant, Richard H.

    2004-10-01

    Ultraviolet radiation-B (UV-B) would increase due to the Ozone depletion. Global climatic factors, such as temperature, precipitation, evapotranspiration, soil moisture and CO2 content, are changing because of the increase of greenhouse emission and the destruction of ecosystems. Climate stress factors including enhanced UV-B irradiance have effects on crop production. Many studies have assessed the effects of enhanced UV-B on crops and impacts of global climatic change on crops separately. However, when UV-B effects were discussed, other environmental stress factors were generally neglected. It is well-known that crops in nature are seldom affected by only a single stress factor, such as UV-B radiation. The impacts of enhanced UV-B radiation can be greatly increased or decreased by other environmental stress factors. In this paper, through field and plant growth chambers experiments, combined effects of enhanced UV-B radiation with other environmental stress factors including solar visible light, temperature and soil moisture content on winter wheat were investigated. The experimental results showed that enhanced UV-B irradiance can restrain growth and development of winter wheat, which leads to reduction of plant height, leaf area, and slowing physiological activity and decreasing biomass and yield of winter wheat. The response of winter wheat to enhanced UV-B varied under different UV-B intensity and its combination with other environmental stress factors.

  7. Ecological correlates of variable organ sizes and fat loads in the most northerly-wintering shorebirds

    USGS Publications Warehouse

    Ruthrauff, Daniel R.; Dekinga, A.; Gill, R.E., Jr.; Summers, R.W.; Piersma, T.

    2013-01-01

    Shorebirds at northern latitudes during the nonbreeding season typically carry relatively large lipid stores and exhibit an up-regulation of lean tissues associated with digestion and thermogenesis. Intraspecific variation in these tissues across sites primarily reflects differences in environmental conditions. Rock (Calidris ptilocnemis (Coues, 1873)) and Purple (Calidris maritima (Brünnich, 1764)) sandpipers are closely related species having the most northerly nonbreeding distributions among shorebirds, living at latitudes up to 61°N in Cook Inlet, Alaska, and up to 71°N in northern Norway, respectively. Cook Inlet is the coldest known site used by nonbreeding shorebirds, and the region’s mudflats annually experience extensive coverage of foraging sites by sea and shore-fast ice. Accordingly, Rock Sandpipers increase their fat stores to nearly 20% of body mass during winter. In contrast, Purple Sandpipers exploit predictably ice-free rocky intertidal foraging sites and maintain low (<6.5%) fat stores. Rock Sandpipers increase the mass of lean tissues from fall to winter, including contour feathers, stomach, and liver components. They also have greater lean pectoralis and supracoracoideus muscle and liver and kidney tissues compared with Purple Sandpipers in winter. This demonstrates a combined emphasis on digestive processes and thermogenesis, whereas Purple Sandpipers primarily augment organs associated with digestive processes. The high winter fat loads and increased lean tissues of Rock Sandpipers in Cook Inlet reflect the region’s persistent cold and abundant but sporadically unavailable food resources.

  8. Winter stream temperature in the rain-on-snow zone of the Pacific northwest: influences of hillslope runoff and transient snow cover

    NASA Astrophysics Data System (ADS)

    Leach, J. A.; Moore, R. D.

    2013-10-01

    Stream temperature dynamics during winter are less well studied than summer thermal regimes, but the winter season thermal regime can be critical for fish growth and development in coastal catchments. The winter thermal regimes of Pacific Northwest headwater streams, which provide vital winter habitat for salmonids and their food sources, may be particularly sensitive to changes in climate because they can remain ice-free throughout the year and are often located in rain-on-snow zones. This study examined winter stream temperature patterns and controls in small headwater catchments within the rain-on-snow zone at the Malcolm Knapp Research Forest, near Vancouver, British Columbia, Canada. Two hypotheses were addressed by this study: (1) winter stream temperatures are primarily controlled by advective fluxes associated with runoff processes and (2) stream temperatures should be depressed during rain-on-snow events, compared to rain-on-bare-ground, due to the cooling effect of rain passing through the snowpack prior to infiltrating the soil or being delivered to the stream as saturation-excess overland flow. A reach-scale energy budget analysis of two winter seasons revealed that the advective energy input associated with hillslope runoff overwhelms the effects of energy exchanges at the stream surface during rain and rain-on-snow events. Historical stream temperature data and modelled snowpack dynamics were used to explore the influence of transient snow cover on stream temperature over 13 winters. When snow was not present, daily stream temperature during winter rain events tended to increase with increasing air temperature. However, when snow was present, stream temperature was capped at about 5 °C, regardless of air temperature. The stream energy budget modelling and historical analysis support both of our hypotheses. A key implication is that climatic warming may generate higher winter stream temperatures in the rain-on-snow zone due to both increased rain temperature and reduced cooling effect of snow cover.

  9. Winter risk estimations through infrared cameras an principal component analysis

    NASA Astrophysics Data System (ADS)

    Marchetti, M.; Dumoulin, J.; Ibos, L.

    2012-04-01

    Thermal mapping has been implemented since the late eighties to measure road pavement temperature along with some other atmospheric parameters to establish a winter risk describing the susceptibility of road network to ice occurrence. Measurements are done using a vehicle circulating on the road network in various road weather conditions. When the dew point temperature drops below road surface temperature a risk of ice occurs and therefore a loss of grip risk for circulating vehicles. To avoid too much influence of the sun, and to see the thermal behavior of the pavement enhanced, thermal mapping is usually done before dawn during winter time. That is when the energy accumulated by the road during daytime is mainly dissipated (by radiation, by conduction and by convection) and before the road structure starts a new cycle. This analysis is mainly done when a new road network is built, or when some major pavement changes are made, or when modifications in the road surroundings took place that might affect the thermal heat balance. This helps road managers to install sensors to monitor road status on specific locations identified as dangerous, or simply to install specific road signs. Measurements are anyhow time-consuming. Indeed, a whole road network can hardly be analysed at once, and has to be partitioned in stretches that could be done in the open time window to avoid temperature artefacts due to a rising sun. The LRPC Nancy has been using a thermal mapping vehicle with now two infrared cameras. Road events were collected by the operator to help the analysis of the network thermal response. A conventional radiometer with appropriate performances was used as a reference. The objective of the work was to compare results from the radiometer and the cameras. All the atmospheric parameters measured by the different sensors such as air temperature and relative humidity were used as input parameters for the infrared camera when recording thermal images. Road thermal heterogeneities were clearly identified, while usually missed by a conventional radiometer. In the case presented here, the two lanes of the road could be properly observed. Promising perspectives appeared to increase the measurement rate. Furthermore, to cope with the climatic constraints of the winter measurements as to build a dynamic winter risk, a multivariate data analysis approach was implemented. Principal component analysis was performed and enabled to set up of dynamic thermal signature with a great agreement between statistical results and field measurements.

  10. Variations in abundance of intestinal helminths of gadwalls (Anas Strepera), mottled ducks (Anas fulvigula) and ring-necked ducks (Aythya collaris) wintering in eastern Texas 

    E-print Network

    Schmid, Jennifer Lynn

    1993-01-01

    decreased through the winter, predominatly due to the increase in abundance of the genus Microsomacanthus. The highest relative density of helminth species occurred in the duodenum and cecae of the hosts. Only one helminth species (Cloacataenia megalops...

  11. The increasing incidence of snowboard-related trauma

    PubMed Central

    Hayes, John R.; Groner, Jonathan I.

    2013-01-01

    Purpose To investigate injuries among children and adolescents who participate in downhill sports. Methods We collected trauma registry data (January 1999–May 2006) from a level 1 pediatric trauma center with an average snowfall of 28 in (71 cm)/y. Cases were analyzed for injury mechanism, injury type, organ injured, Injury Severity Score, age, sex, and whether or not an operation was required. Results There were 57 snowboarders and 22 skiers admitted during the study period. Forty-one (72%) of snowboarders and 16 (73%) of skiers required operations; 32 (56%) of snowboarders and 9 (41%) of skiers sustained fractures; and 14 (25%) of snowboarders and 6 (27%) of skiers sustained abdominal injuries. (P = NS for all comparisons). Serious splenic injuries were more common in snowboarders (14% vs 4%), but the difference was not statistically significant. All skiing injuries occurred at recreational facilities (commercial skiing areas), whereas 12% of snowboard injuries occurred at home, other residence, or public parks (P = .08). The most striking finding is the rising number of snowboarding injuries and the relatively stable rate of skiing injuries (see graph). Conclusions As the popularity of snowboarding rises, snowboarding injuries in children are increasing. Pediatric surgeons should be wary of the “snowboard spleen.” PMID:18485968

  12. Climate change in winter versus the growing-season leads to different effects on soil microbial activity in northern hardwood forests

    NASA Astrophysics Data System (ADS)

    Sorensen, P. O.; Templer, P. H.; Finzi, A.

    2014-12-01

    Mean winter air temperatures have risen by approximately 2.5? C per decade over the last fifty years in the northeastern U.S., reducing the maximum depth of winter snowpack by approximately 26 cm over this period and the duration of winter snow cover by 3.6 to 4.2 days per decade. Forest soils in this region are projected to experience a greater number of freeze-thaw cycles and lower minimum winter soil temperatures as the depth and duration of winter snow cover declines in the next century. Climate change is likely to result not only in lower soil temperatures during winter, but also higher soil temperatures during the growing-season. We conducted two complementary experiments to determine how colder soils in winter and warmer soils in the growing-season affect microbial activity in hardwood forests at Harvard Forest, MA and Hubbard Brook Experimental Forest, NH. A combination of removing snow via shoveling and buried heating cables were used to induce freeze-thaw events during winter and to warm soils 5?C above ambient temperatures during the growing-season. Increasing the depth and duration of soil frost via snow-removal resulted in short-term reductions in soil nitrogen (N) production via microbial proteolytic enzyme activity and net N mineralization following snowmelt, prior to tree leaf-out. Declining mass specific rates of carbon (C) and N mineralization associated with five years of snow removal at Hubbard Brook Experimental Forest may be an indication of microbial physiological adaptation to winter climate change. Freeze-thaw cycles during winter reduced microbial extracellular enzyme activity and the temperature sensitivity of microbial C and N mineralization during the growing-season, potentially offsetting nutrient and soil C losses due to soil warming in the growing-season. Our multiple experimental approaches show that winter climate change is likely to contribute to reduced microbial activity in northern hardwood forests.

  13. Environmental contaminants in redheads wintering in coastal Louisiana and Texas

    USGS Publications Warehouse

    Michot, T.C.; Custer, T.W.; Nault, A.J.; Mitchell, C.A.

    1994-01-01

    Whole body and liver analyses indicated that wintering redheads (Aythya americana; n=70) in coastal Louisiana (one site) and Texas (two sites) were relatively free of contamination with common trace elements, organochlorines, and hydrocarbons. Most trace elements, including As, Cr, Hg, Mg, Mn, Ni, Pb, Se, Sr, and Zn, were within background concentrations in livers; levels of B, Cd, Cu, and Fe were elevated in some specimens. Only one organochlorine, DDE, was detected in redhead carcasses, but its concentration was below reported toxic levels in waterfowl. Body burdens of aliphatic and aromatic hydrocarbons were generally low, but levels of pristane, total hydrocarbons, and the ratios of phytane:n-octadecane and pristane:n-heptadecane were indicative of possible chronic exposure to petroleum. Based on brain cholinesterase assays, redheads were not recently exposed to organophosphorous or carbamate pesticides. Of 30 elements or compounds tested for seasonal differences, only Se increased from early to late winter at one of the three sites. Eight of 57 contaminants differed among the three sites; no sex or age differences were found.

  14. Environmental contaminants in redheads wintering in coastal Louisiana and Texas

    USGS Publications Warehouse

    Michot, T.C.; Custer, T.W.; Nault, A.J.; Mitchell, C.A.

    1994-01-01

    Whole body and liver analyses indicated that wintering redheads (Aythya americana; n = 70) in coastal Louisiana (one site) and Texas (two sites) were relatively free of contamination with common trace elements, organochlorines, and hydrocarbons. Most trace elements, including As, Cr, Hg, Mg, Mn, Ni, Pb, Se, Sr, and Zn, were within background concentrations in livers; levels of B, Cd, Cu, and Fe were elevated in some specimens. Only one organochlorine, DDE, was detected in redhead carcasses, but its concentration was below reported toxic levels in waterfowl. Body burdens of aliphatic and aromatic hydrocarbons were generally low, but levels of pristane, total hydrocarbons, and the ratios of phytane:n-octadecane and pristane:n-heptadecane were indicative of possible chronic exposure to petroleum. Based on brain cholinesterase assays, redheads were not recently exposed to organophosphorous or carbamate pesticides. Of 30 elements or compounds tested for seasonal differences, only Se increased from early to late winter at one of the three sites. Eight of 57 contaminants differed among the three sites; no sex or age differences were found.

  15. General circulation model simulation of mild nuclear winter effects

    NASA Astrophysics Data System (ADS)

    Pittock, A. B.; Walsh, K.; Frederiksen, J. S.

    1989-04-01

    The climatic effects of an elevated uniform global layer of purely absorbing smoke of absorption optical depth 0.2 have been simulated using a version of the 9-level spectral model of McAvaney et al. (1978). The model was run at rhomboidal wave number 21 with convective adjustment, prognostic precipitation and soil hydrology, but fixed zonally averaged climatological cloud and fixed sea surface temperature, for constant January and July conditions with and without smoke absorption. Results show a reduction in convective rainfall in the tropics and monsoonal regions of the order of 50%, with diurnal average soil surface coolings of several degrees C except in those locations where the reduction in soil moisture is sufficient to effectively stop evaporation at the surface. In that case, small increases in temperature may occur. Results over Australia are consistent with the zonal mean picture. Run in a diurnal cycle mode, the model shows that daily maximum temperatures are more strongly affected, with soil surface coolings of the order of 2° 3° C in summer (with some local warmings) and 4° 6° C in winter. Overninght minimum temperatures cool by only 1° 2° C in both summer and winter. Possible effects of a lowering of sea surface temperature, variations in cloud cover, neglect of scattering by smoke, and infrared absorption and emission by the smoke are discussed.

  16. Processes Controlling Water Vapor in the Winter Arctic Tropopause Region

    NASA Technical Reports Server (NTRS)

    Pfister, Leonhard; Selkirk, Henry B.; Jensen, Eric J.; Padolske, James; Sachse, Glen; Avery, Melody; Schoeberl, Mark R.; Mahoney, Michael J.; Richard, Erik

    2002-01-01

    This work describes transport and thermodynamic processes that control water vapor near the tropopause during the SAGE III-Ozone Loss and Validation Experiment (SOLVE), held during the Arctic 1999/2000 winter season. Aircraft-based water vapor, carbon monoxide, and ozone measurements were analyzed so as to establish how deeply tropospheric air mixes into the Arctic lowermost stratosphere and what the implications are for cloud formation and water vapor removal in this region of the atmosphere. There are three major findings. First, troposphere-to-stratosphere exchange extends into the Arctic stratosphere to about 13 km. Penetration is to similar levels throughout the winter, however, because ozone increases with altitude most rapidly in the early spring, tropospheric air mixes with the highest values of ozone in that season. The effect of this upward mixing is to elevate water vapor mixing ratios significantly above their prevailing stratospheric values of above 5ppmv. Second, the potential for cloud formation in the stratosphere is highest during early spring, with about 20% of the parcels which have ozone values of 300-350 ppbv experiencing ice saturation in a given 10 day period. Third, during early spring, temperatures at the troposphere are cold enough so that 5-10% of parcels experience relative humidities above 100%, even if the water content is as low as 5 ppmv. The implication is that during this period, dynamical processes near the Arctic tropopause can dehydrate air and keep the Arctic tropopause region very dry during early spring.

  17. Climate and smoke: an appraisal of nuclear winter.

    PubMed

    Turco, R P; Toon, O B; Ackerman, T P; Pollack, J B; Sagan, C

    1990-01-12

    The latest understanding of nuclear winter is reviewed. Considerable progress has been made in quantifying the production and injection of soot by large-scale fires, the regional and global atmospheric dispersion of the soot, and the resulting physical, environmental, and climatic perturbations. New information has been obtained from laboratory studies, field experiments, and numerical modeling on a variety of scales (plume, mesoscale, and global). For the most likely soot injections from a full-scale nuclear exchange, three-dimensional climate simulations yield midsummer land temperature decreases that average 10 degrees to 20 degrees C in northern mid-latitudes, with local cooling as large as 35 degrees C, and subfreezing summer temperatures in some regions. Anomalous atmospheric circulations caused by solar heating of soot is found to stabilize the upper atmosphere against overturning, thus increasing the soot lifetime, and to accelerate interhemispheric transport, leading to persistent effects in the Southern Hemisphere. Serious new environmental problems associated with soot injection have been identified, including disruption of monsoon precipitation and severe depletion of the stratospheric ozone layer in the Northern Hemisphere. The basic physics of nuclear winter has been reaffirmed through several authoritative international technical assessments and numerous individual scientific investigations. Remaining areas of uncertainty and research priorities are discussed in view of the latest findings. PMID:11538069

  18. Downstream movement of fall Chinook salmon juveniles in the lower Snake River reservoirs during winter and early spring

    USGS Publications Warehouse

    Tiffan, Kenneth F.; Kock, Tobias J.; Connor, William P.; Mullins, Frank; Steinhorst, R. Kirk

    2012-01-01

    We conducted a 3-year radiotelemetry study in the lower Snake River to (1) determine whether juvenile fall Chinook salmon Oncorhynchus tshawytscha pass dams during winter, when bypass systems and structures designed to prevent mortality are not operated; (2) determine whether downstream movement rate varies annually, seasonally, and from reservoir to reservoir; and (3) identify some of the factors that contribute to annual, seasonal, and spatial variation in downstream movement rate. Fall Chinook salmon juveniles moved downstream up to 169 km and at a sufficiently fast rate (7.5 km/d) such that large percentages (up to 93%) of the fish passed one or more dams during the winter. Mean downstream movement rate varied annually (9.2–11.3 km/d), increased from winter (7.5 km/d) to spring (16.4 km/d), and increased (from 6.9 to 16.8 km/d) as fish moved downstream from reservoir to reservoir. Fish condition factor at tagging explained some of the annual variation in downstream movement rate, whereas water particle velocity and temperature explained portions of the seasonal variation. An increase in migrational disposition as fish moved downstream helped to explain the spatial variation. The potential cost of winter movement might be reduced survival due to turbine passage at a time when the bypass systems and spillway passage structures are not operated. Efforts to understand and increase passage survival of winter migrants in large impoundments might help to rehabilitate some imperiled anadromous salmonid populations.

  19. Vigilance patterns of wintering Eurasian Wigeon: female benefits from male low-cost behaviour

    Microsoft Academic Search

    Steven J. Portugal; Matthieu Guillemain

    2011-01-01

    Increased vigilance in male animals has been attributed to mate guarding (male investment hypothesis), to secondary sexual\\u000a characteristics increasing predation risk (male constraint hypothesis) or for the benefit to the female (female benefits\\u000a hypothesis). We studied Eurasian Wigeon (Anas penelope) while they grazed on dry land, a ‘risky’ foraging situation, at two points during the winter period (pre- and post-pair

  20. Metabolic response to lipid infusion in fasting winter-acclimatized king penguin chicks (Aptenodytes patagonicus).

    PubMed

    Teulier, Loïc; Tornos, Jérémy; Rouanet, Jean-Louis; Rey, Benjamin; Roussel, Damien

    2013-05-01

    During the cold austral winter, king penguin chicks are infrequently fed by their parents and thus experience severe nutritional deprivation under harsh environmental conditions. These energetic constraints lead to a range of energy sparing mechanisms balanced by the maintenance of efficient thermogenic processes. The present work investigated whether the high thermogenic capacities exhibited by winter-acclimatized king penguin chicks could be related to an increase in lipid substrate supply and oxidation in skeletal muscle, the main site of thermogenesis in birds. To test this hypothesis, we examined i) the effect of an experimental rise in plasma triglyceride on the whole metabolic rate in winter-acclimatized (WA) and de-acclimatized king penguin chicks kept at thermoneutrality (TN), and ii) investigated the fuel preference of muscle mitochondria. In vivo, a perfusion of a lipid emulsion induced a small 10% increase of metabolic rate in WA chicks but not in TN group. In vitro, the oxidation rate of muscle mitochondria respiring on lipid-derived substrate was +40% higher in WA chicks than in TN, while no differences were found between groups when mitochondria oxidized carbohydrate-derived substrate or succinate. Despite an enhanced fuel selection towards lipid oxidation in skeletal muscle, a rise of circulating lipids per se was not sufficient to fully unravel the thermogenic capacity of winter-acclimatized king penguin chicks. PMID:23428720

  1. Estimating flow rates to optimize winter habitat for centrarchid fish in mississippi river (USA) backwaters

    USGS Publications Warehouse

    Johnson, B.L.; Knights, B.C.; Barko, J.W.; Gaugush, R.F.; Soballe, D.M.; James, W.F.

    1998-01-01

    The backwaters of large rivers provide winter refuge for many riverine fish, but they often exhibit low dissolved oxygen levels due to high biological oxygen demand and low flows. Introducing water from the main channel can increase oxygen levels in backwaters, but can also increase current velocity and reduce temperature during winter, which may reduce habitat suitability for fish. In 1993, culverts were installed to introduce flow to the Finger Lakes, a system of six backwater lakes on the Mississippi River, about 160 km downstream from Minneapolis, Minnesota. The goal was to improve habitat for bluegills and black crappies during winter by providing dissolved oxygen concentrations > 3 mg/L, current velocities < 1 cm/s, and temperatures < 1??C. To achieve these conditions, we used data on lake volume and oxygen demand to estimate the minimum flow required to maintain 3 mg/L of dissolved oxygen in each lake. Estimated flows ranged from 0.02 to 0.14 m3/s among lakes. Data gathered in winter 1994 after the culverts were opened, indicated that the estimated flows met habitat goals, but that thermal stratification and lake morphometry can reduce the volume of optimal habitat created.

  2. Distribution Surge Arrester Failures due to Winter Lightning and Measurement of Energy Absorption Capability of Arresters

    NASA Astrophysics Data System (ADS)

    Sugimoto, Hitoshi; Shimasaki, Katsuhiko; Kado, Hiroyuki

    Surge arresters and distribution equipments with zinc-oxide elements are used for lightning protection of overhead power distribution lines in Japan. However, these surge arresters are sometimes damaged by direct lightning strokes, especially in winter. Increasing of surge arrester failures in winter is attributed to a very large electric charge of winter lightning than that of summer lightning. For improvement of surge arresters, we have measured the energy absorption capability of surge arresters using a half cycle of alternating current with a frequency of 50Hz for simulating a winter lightning current. The mean values of arrester failure energy increased in proportion to the volume of zinc-oxide element, however the values of arrester failure energy were quite uneven. We also have observed the aspects of damaged zinc-oxide elements, and have investigated the relationship between the arrester failure energy and the failure types of zinc-oxide elements. From these results, we suggest the improvement of the energy absorption capability of distribution surge arresters, especially for the uniform energy absorption capability.

  3. Role of the SST over the East China Sea in the linkage between East Asian winter and summer monsoon variability.

    NASA Astrophysics Data System (ADS)

    Kajikawa, Y.; Seo, Y. W.; Yun, K. S.; Ha, K. J.; Johnson, R. H.

    2014-12-01

    The SST and SST gradient over the East China Sea (ECS) and the Northern South China Sea have large interannual variability in boreal winter and spring, especially in March and April. We investigated these SST and SST gradient anomalies and found the important role of these anomalies in the linkage between Asian winter and summer monsoon variability by using observational datasets during 1979-2012. The interannual variability of SST over the ECS in April shows significant warming trend. Of great interest is that the SST anomalies are confined around the ECS and not significantly related to the broad scale Pacific and Indian Ocean SST anomalies. These anomalies appear from boreal winter. The warmer SST anomalies in recent decades are well associated with the weakening of the northeasterly flow along the southern China, East Asian winter monsoon. It reduces the surface wind speed and tends to produce the warmer SST and less SST gradient during boreal winter by decreasing of evaporation and upwelling. These anomalies are maintained and enhanced until the climatological wind direction change in early summer. These warmer SST and less SST gradient anomalies lead to enhanced Meiyu rainfall over the southeastern part of China. This suggests that the increasing rainfall trend over the southern part of China in June indicated by Kajikawa et al (2012) can be explained by the weakening of the East Asian winter monsoon through the SST anomalies over the ECS.

  4. Variation in the hindgut microbial communities of the Florida manatee, Trichechus manatus latirostris over winter in Crystal River, Florida

    USGS Publications Warehouse

    Merson, Samuel D.; Ouwerkerk, Diane; Gulino, Lisa-Maree; Klieve, Athol; Bonde, Robert K.; Burgess, Elizabeth A.; Lanyon, Janet M.

    2014-01-01

    The Florida manatee, Trichechus manatus latirostris, is a hindgut-fermenting herbivore. In winter, manatees migrate to warm water overwintering sites where they undergo dietary shifts and may suffer from cold-induced stress. Given these seasonally induced changes in diet, the present study aimed to examine variation in the hindgut bacterial communities of wild manatees overwintering at Crystal River, west Florida. Faeces were sampled from 36 manatees of known sex and body size in early winter when manatees were newly arrived and then in mid-winter and late winter when diet had probably changed and environmental stress may have increased. Concentrations of faecal cortisol metabolite, an indicator of a stress response, were measured by enzyme immunoassay. Using 454-pyrosequencing, 2027 bacterial operational taxonomic units were identified in manatee faeces following amplicon pyrosequencing of the 16S rRNA gene V3/V4 region. Classified sequences were assigned to eight previously described bacterial phyla; only 0.36% of sequences could not be classified to phylum level. Five core phyla were identified in all samples. The majority (96.8%) of sequences were classified as Firmicutes (77.3 ± 11.1% of total sequences) or Bacteroidetes (19.5 ± 10.6%). Alpha-diversity measures trended towards higher diversity of hindgut microbiota in manatees in mid-winter compared to early and late winter. Beta-diversity measures, analysed through permanova, also indicated significant differences in bacterial communities based on the season.

  5. Evaluating potential effects of an industrial road on winter habitat of caribou in North-Central Alaska

    USGS Publications Warehouse

    Wilson, Ryan R.; Gustine, David D.; Joly, Kyle

    2014-01-01

    Worldwide, some caribou (Rangifer tarandus) populations are experiencing declines due partially to the expansion of industrial development. Caribou can exhibit behavioral avoidance of development, leading to indirect habitat loss, even if the actual footprint is small. Thus, it is important to understand before construction begins how much habitat might be affected by proposed development. In northern Alaska, an industrial road that has been proposed to facilitate mining transects a portion of the Western Arctic caribou herd's winter range. To understand how winter habitat use might be affected by the road, we estimated resource selection patterns during winter for caribou in a study area surrounding the proposed road. We assessed the reductions of habitat value associated with three proposed routes at three distance thresholds for disturbance. High-value winter habitat tended to occur in locally rugged areas that have not burned recently and have a high density of lichen and early dates of spring snowmelt. We found that 1.5% to 8.5% (146-848 km2) of existing high-value winter habitat in our study area might be reduced in quality. The three alternative routes were only marginally different. Our results suggest that the road would have minimal direct effects on high-value winter habitat; however, additional cumulative impacts to caribou (e.g., increased access by recreationists and hunters) should be considered before the full effects of the road can be estimated.

  6. Linking summer foraging to winter survival in yellow pine chipmunks (Tamias amoenus).

    PubMed

    Kuhn, Kellie M; Vander Wall, Stephen B

    2008-08-01

    This study links summer foraging and scatter-hoarding to winter larder-hoarding and winter survival in yellow pine chipmunks (Tamias amoenus) by comparing patterns of time allocation and winter larder contents in 2 years with very different levels of resource availability. In 2003, seed production and the number of trees and shrubs producing seeds were high. In 2004 seed crops were small. Chipmunks allocated more time to foraging when food resources were scarce (66% in 2004) compared to when they were abundant (39% in 2003). Increased time allocated to foraging in 2004 corresponded to significant decreases in time allocated to vigilance, resting, and social interactions. When seeds were scarce (i.e., in autumn 2004), chipmunks spent more time searching for cached food items than gathering seeds from plants or the ground surface. Despite the increase in foraging effort, the edible mass and caloric contents of larders were significantly smaller in 2004. In the year with low seed production, the diversity of seed species found in larders increased, and many of these seeds were of species that ripened in summer. When autumnal seed production by Jeffrey pine seeds was high, Jeffrey pine seeds were nearly the exclusive food item found in larders. Larder contents would have provisioned chipmunks for an estimated 116-257 days in 2003 and but only 6-111 days in 2004. It is likely that all chipmunks would have survived the winter of 2003 (duration approximately 110-120 days). However, none of the larders recovered in 2004 contained enough food to have provisioned the inhabitant for the approximately148-158 days of winter. PMID:18560900

  7. Comparison of winter wheat growth with multi-temporal remote sensing imagery

    NASA Astrophysics Data System (ADS)

    Xiaoyu, Song; Bei, Cui; Guijun, Yang; Haikuan, Feng

    2014-03-01

    Leaf area index (LAI) is an important index for crop growth monitoring. This paper focused on estimation of winter wheat LAI dynamics in different growth stages based on Landsat TM data. In order to retrieve wheat LAI from remote sensing data, LAI measurements were initiated when Landsat satellite pass over the study region. Three Landsat5 TM images were acquired on April 15, May 17, and June 2, 2009, corresponding to jointing stage, flowering stage and milking stage of wheat. LAI was measured at each stage in thirty wheat fields distributed in Beijing suburb. Based on the TM images, spectral indices including NDVI, MSAVI, SAVI, RDVI, SR, ISR, MSR and NLI were calculated. Univariate correlation analysis was then conducted between LAI data and corresponding TM spectral variables. The analysis results indicated that TM ISR on April 15, TM Band4 on May17, and TM ISR on June 2 were very significantly correlated with LAI, and the coefficient values were 0.736, 0.548 and 0.493, respectively. LAI map of winter wheat for whole study area was produced based on optimal non-linear correlation models. The three LAI maps were used to winter wheat growth analysis and comparison of different growth stages. Study results indicated that from April 15 to May 17, LAI value for 14.88% of winter wheat fields (9131ha) increased less than 1, 64.43 % (39421 ha) increased between 1 to 2, 20.67 % (12685 ha) increased more than 2. LAI decreased from May 17 to June 2. 45.34% of winter wheat fields (27828 ha) decreased less than1, 45.20 % (27738 ha) decreased between 1 to 2, 9.33% (5725.42 ha) decreased more than 2.

  8. Seasonal Acclimatization in Summer versus Winter to Changes in the Sweating Response during Passive Heating in Korean Young Adult Men.

    PubMed

    Lee, Jeong-Beom; Kim, Tae-Wook; Min, Young-Ki; Yang, Hun-Mo

    2015-01-01

    We investigated the sweating response during passive heating (partial submersion up to the umbilical line in 42±0.5? water, 30 min) after summer and winter seasonal acclimatization (SA). Testing was performed in July during the summer, 2011 [summer-SA; temp, 25.6±1.8?; relative humidity (RH), 82.1±8.2%] and in January during the winter, 2012 (winter-SA; temp, -2.7±2.9?; RH, 65.0±13.1%) in Cheonan (126°52'N, 33.38'E), Republic of Korea. All experiments were carried out in an automated climatic chamber (temp, 25.0±0.5?: RH, 60.0±3.0%). Fifteen healthy men (age, 23.4±2.5 years; height, 175.0±5.9 cm; weight, 65.3±6.1 kg) participated in the study. Local sweat onset time was delayed during winter-SA compared to that after summer-SA (p< 0.001). Local sweat volume, whole body sweat volume, and evaporative loss volume decreased significantly after winter-SA compared to those after summer-SA (p<0.001). Changes in basal metabolic rate increased significantly after winter-SA (p< 0.001), and tympanic temperature and mean body temperature were significantly lower after summer-SA (p<0.05). In conclusion, central sudomotor acitivity becomes sensitive to summer-SA and blunt to winter-SA in Rebubic of Korea. These results suggest that the body adjusts its temperature by economically controlling the sweating rate but does not lower the thermal dissipation rate through a more effective evaporation scheme after summer-SA than that after winter-SA. PMID:25605991

  9. Climate-driven effects of fire on winter habitat for caribou in the Alaskan-Yukon Arctic

    USGS Publications Warehouse

    Gustine, David D.; Brinkman, Todd J.; Lindgren, Michael A.; Schmidt, Jennifer I.; Rupp, T. Scott; Adams, Layne G.

    2014-01-01

    Climatic warming has direct implications for fire-dominated disturbance patterns in northern ecosystems. A transforming wildfire regime is altering plant composition and successional patterns, thus affecting the distribution and potentially the abundance of large herbivores. Caribou (Rangifer tarandus) are an important subsistence resource for communities throughout the north and a species that depends on terrestrial lichen in late-successional forests and tundra systems. Projected increases in area burned and reductions in stand ages may reduce lichen availability within caribou winter ranges. Sufficient reductions in lichen abundance could alter the capacity of these areas to support caribou populations. To assess the potential role of a changing fire regime on winter habitat for caribou, we used a simulation modeling platform, two global circulation models (GCMs), and a moderate emissions scenario to project annual fire characteristics and the resulting abundance of lichen-producing vegetation types (i.e., spruce forests and tundra >60 years old) across a modeling domain that encompassed the winter ranges of the Central Arctic and Porcupine caribou herds in the Alaskan-Yukon Arctic. Fires were less numerous and smaller in tundra compared to spruce habitats throughout the 90-year projection for both GCMs. Given the more likely climate trajectory, we projected that the Porcupine caribou herd, which winters primarily in the boreal forest, could be expected to experience a greater reduction in lichen-producing winter habitats (?21%) than the Central Arctic herd that wintered primarily in the arctic tundra (?11%). Our results suggest that caribou herds wintering in boreal forest will undergo fire-driven reductions in lichen-producing habitats that will, at a minimum, alter their distribution. Range shifts of caribou resulting from fire-driven changes to winter habitat may diminish access to caribou for rural communities that reside in fire-prone areas.

  10. Seasonal Acclimatization in Summer versus Winter to Changes in the Sweating Response during Passive Heating in Korean Young Adult Men

    PubMed Central

    Lee, Jeong-Beom; Min, Young-Ki; Yang, Hun-Mo

    2015-01-01

    We investigated the sweating response during passive heating (partial submersion up to the umbilical line in 42±0.5? water, 30 min) after summer and winter seasonal acclimatization (SA). Testing was performed in July during the summer, 2011 [summer-SA; temp, 25.6±1.8?; relative humidity (RH), 82.1±8.2%] and in January during the winter, 2012 (winter-SA; temp, -2.7±2.9?; RH, 65.0±13.1%) in Cheonan (126°52'N, 33.38'E), Republic of Korea. All experiments were carried out in an automated climatic chamber (temp, 25.0±0.5?: RH, 60.0±3.0%). Fifteen healthy men (age, 23.4±2.5 years; height, 175.0±5.9 cm; weight, 65.3±6.1 kg) participated in the study. Local sweat onset time was delayed during winter-SA compared to that after summer-SA (p< 0.001). Local sweat volume, whole body sweat volume, and evaporative loss volume decreased significantly after winter-SA compared to those after summer-SA (p<0.001). Changes in basal metabolic rate increased significantly after winter-SA (p< 0.001), and tympanic temperature and mean body temperature were significantly lower after summer-SA (p<0.05). In conclusion, central sudomotor acitivity becomes sensitive to summer-SA and blunt to winter-SA in Rebubic of Korea. These results suggest that the body adjusts its temperature by economically controlling the sweating rate but does not lower the thermal dissipation rate through a more effective evaporation scheme after summer-SA than that after winter-SA. PMID:25605991

  11. Chem 249 Problem Set 5 Winter 2014

    E-print Network

    Chem 249 Problem Set 5 R. Corn Winter 2014 The Zeeman Effect in Hydrogen and Sodium Rabi Vectors. (YOU CAN DO BOTH 2 AND 3 IF YOU'D LIKE EXTRA CREDIT) 1. Sodium Doublet and the Zeeman Effect 1.1) We) for definitions of H0, WSO and WZ. 1.2) Pieter Zeeman won the Nobel Prize in Physics in 1902 for the splitting

  12. A winter anomaly campaign in Western Europe

    Microsoft Academic Search

    D. Offermann

    1980-01-01

    An integrated campaign of ground-based, balloon- and rocket-borne measurements was performed in Western Europe during pronounced disturbances of ionospheric D-region electron density (winter anomaly). Various atmospheric and ionospheric parameters were measured in the altitude regime 30-120 km. A large set of middle atmosphere temperature data as obtained from satellites is also available for the time period of the campaign. Some

  13. Arnold Schwarzenegger TRENDS IN SNOWFALL VERSUS

    E-print Network

    for the Western United States, 1949­2001. California Energy Commission, PIER EnergyRelated Environmental STATES, 1949­2001 Prepared For: California Energy Commission Public Interest Energy Research Program Prepared By: United States Geological Survey Scripps Institution of Oceanography PIERPROJECTREPORT

  14. Flowering time control in European winter wheat

    PubMed Central

    Langer, Simon M.; Longin, C. Friedrich H.; Würschum, Tobias

    2014-01-01

    Flowering time is an important trait in wheat breeding as it affects adaptation and yield potential. The aim of this study was to investigate the genetic architecture of flowering time in European winter bread wheat cultivars. To this end a population of 410 winter wheat varieties was evaluated in multi-location field trials and genotyped by a genotyping-by-sequencing approach and candidate gene markers. Our analyses revealed that the photoperiod regulator Ppd-D1 is the major factor affecting flowering time in this germplasm set, explaining 58% of the genotypic variance. Copy number variation at the Ppd-B1 locus was present but explains only 3.2% and thus a comparably small proportion of genotypic variance. By contrast, the plant height loci Rht-B1 and Rht-D1 had no effect on flowering time. The genome-wide scan identified six QTL which each explain only a small proportion of genotypic variance and in addition we identified a number of epistatic QTL, also with small effects. Taken together, our results show that flowering time in European winter bread wheat cultivars is mainly controlled by Ppd-D1 while the fine tuning to local climatic conditions is achieved through Ppd-B1 copy number variation and a larger number of QTL with small effects. PMID:25346745

  15. Monitoring Gully Activity in Martian Winter

    NASA Astrophysics Data System (ADS)

    Dundas, C. M.; Diniega, S.; Hansen, C. J.; Byrne, S.; McEwen, A. S.

    2012-12-01

    Recent work has shown that Martian gullies are active in the present climate, on sand dunes and on crater walls and other slopes. Observations include large-scale channel incision (particularly in dune gullies), transport of boulders, alcove collapse and extensive deposition on aprons. Hence, we find that all of the major morphological features of gullies are evolving today and that current processes do not merely degrade features formed under past orbital and climate conditions. This is particularly clear for gullies on sand dunes, which have been observed to form on smooth slopes and remain morphologically pristine despite active eolian sand transport; morphological similarities suggest that the same processes are involved in formation of gullies on non-dune slopes. Channel incision is particularly intriguing since this has been taken as evidence for liquid water in the past. In addition to the scope of changes, the other striking feature of present-day gully activity is seasonality. Changes are concentrated in the winter, suggesting an association with seasonal CO2 frost or defrosting activity; it is difficult to generate volumes of liquid water that might play a relevant role in the large-scale gully changes observed. We are conducting a campaign to monitor activity in the current Martian southern winter using the High Resolution Imaging Science Experiment (HiRISE) camera. Partway through the winter, indications of activity have already been observed in multiple gullies. We will present results from this monitoring campaign and compare this season's activity with observations from previous years.

  16. Effects of changing climate and cultivar on the phenology and yield of winter wheat in the North China Plain

    NASA Astrophysics Data System (ADS)

    Li, Kenan; Yang, Xiaoguang; Tian, Hanqin; Pan, Shufen; Liu, Zhijuan; Lu, Shuo

    2015-05-01

    Understanding how changing climate and cultivars influence crop phenology and potential yield is essential for crop adaptation to future climate change. In this study, crop and daily weather data collected from six sites across the North China Plain were used to drive a crop model to analyze the impacts of climate change and cultivar development on the phenology and production of winter wheat from 1981 to 2005. Results showed that both the growth period (GP) and the vegetative growth period (VGP) decreased during the study period, whereas changes in the reproductive growth period (RGP) either increased slightly or had no significant trend. Although new cultivars could prolong the winter wheat phenology (0.3˜3.8 days per decade for GP), climate warming impacts were more significant and mainly accounted for the changes. The harvest index and kernel number per stem weight have significantly increased. Model simulation indicated that the yield of winter wheat exhibited increases (5.0˜19.4 %) if new cultivars were applied. Climate change demonstrated a negative effect on winter wheat yield as suggested by the simulation driven by climate data only (-3.3 to -54.8 kg ha-1 year-1, except for Lushi). Results of this study also indicated that winter wheat cultivar development can compensate for the negative effects of future climatic change.

  17. Brief Chilling to Subzero Temperature Increases Cold Hardiness in the Hatchling Painted Turtle (Chrysemys picta)

    E-print Network

    Lee Jr., Richard E.

    (Chrysemys picta) * Corresponding author. Present address: Biology Department, Augustana Col- lege, Rock (Chrysemys picta) to increase cold hardiness in response to brief exposure to a subzero temper- ature. Winter

  18. Changes in the status of harvested rice fields in the Sacramento Valley, California: Implications for wintering waterfowl.

    USGS Publications Warehouse

    Miller, Michael R.; Garr, Jay D.; Coates, Peter S.

    2010-01-01

    Harvested rice fields provide critical foraging habitat for wintering waterfowl in North America, but their value depends upon post-harvest treatments. We visited harvested ricefields in the Sacramento Valley, California, during the winters of 2007 and 2008 (recent period) and recorded their observed status as harvested (standing or mechanically modified stubble), burned, plowed, or flooded. We compared these data with those from identical studies conducted during the 1980s (early period). We documented substantial changes in field status between periods. First, the area of flooded rice increased 4-5-fold, from about 15% to >40% of fields, because of a 3-4-fold increase in the percentage of fields flooded coupled with a 37-41% increase in the area of rice produced. Concurrently, the area of plowed fields increased from 35% of fields, burned fields declined from about 40% to 1%, and fields categorized as harvested declined from 22-54% to <15%. The increased flooding has likely increased access to food resources for wintering waterfowl, but this benefit may not be available to some goose species, and may be at least partially countered by the increase of plowed fields, especially those left dry, and the decrease of fields left as harvested.We encourage waterfowl managers to implement a rice field status survey in the Sacramento Valley and other North American rice growing regions as appropriate to support long-term monitoring programs and wetland habitat conservation planning for wintering waterfowl.

  19. Exceptional Bora outbreak in winter 2012: Validation and analysis of high-resolution atmospheric model simulations in the northern Adriatic area

    NASA Astrophysics Data System (ADS)

    Davolio, Silvio; Stocchi, Paolo; Benetazzo, Alvise; Bohm, Emanuele; Riminucci, Francesco; Ravaioli, Mariangela; Li, Xiao-Ming; Carniel, Sandro

    2015-09-01

    The Bora wind event occurred in winter 2012 was exceptional in terms of both meteorological effects and impact on the Adriatic Sea circulation. It was associated with intense and persistent winds, very cold temperatures all over the Mediterranean basin and heavy snowfall over the Apennines slopes exposed to north-easterly winds, and it was responsible for triggering dense water formation and driving basin-scale oceanic circulation. The cooling period (29 January-13 February) was characterized by intense air-sea exchanges of momentum and heat, whose accurate simulation is required for a proper description of atmospheric and ocean circulations. In the present study, results of a number of short-range high-resolution numerical weather prediction (NWP) model simulations for the entire Bora outbreak are discussed. The modeling chain, based on BOLAM and MOLOCH limited area models, has been implemented using initial and boundary conditions provided by different global NWP systems. Model performance has been evaluated in terms of variables of interest for oceanographic applications, such as sea surface temperature (SST), surface heat fluxes, solar radiation and near surface meteorological parameters (air temperature, wind, pressure and humidity). The validation has been undertaken through a comparison against surface data (buoys and oceanographic platforms) available at different locations in the northern Adriatic area, while advanced synthetic aperture radar (ASAR) products have been used to assess modeled wind fields on a larger scale. Model results indicate a good agreement with the observations concerning meteorological variables, in particular wind, pressure and temperature. However, large differences were found in the SST forecasts, which in turn affect also sea surface flux predictions. The uncertainties in SST forecasts are mainly ascribable to the different initialization fields provided by either the global models or satellite analyses. Thus SST initialization represents a critical issue for an accurate description of surface fluxes at least for this exceptionally severe event.

  20. Increases in the annual range of soil water storage at northern middle and high latitudes under global warming

    NASA Astrophysics Data System (ADS)

    Wu, Wen-Ying; Lan, Chia-Wei; Lo, Min-Hui; Reager, John T.; Famiglietti, James S.

    2015-05-01

    Soil water storage is a fundamental signal in the land hydrological cycle and changes in soil moisture can affect regional climate. In this study, we used simulations from Coupled Model Intercomparison Project Phase 5 archives to investigate changes in the annual range of soil water storage under global warming at northern middle and high latitudes. Results show that future warming could lead to significant declines in snowfall, and a corresponding lack of snowmelt water recharge to the soil, which makes soil water less available during spring and summer. Conversely, more precipitation as rainfall results in higher recharge to soil water during its accumulating season. Thus, the wettest month of soil water gets wetter, and the driest month gets drier, resulting in an increase of the annual range and suggesting that stronger heterogeneity in global water distribution (changing extremes) could occur under global warming; this has implications for water management and water security under a changing climate.

  1. Food Preferences of Winter Bird Communities in Different Forest Types

    PubMed Central

    Renner, Swen C.; Baur, Sofia; Possler, Astrid; Winkler, Julia; Kalko, Elisabeth K. V.; Bates, Paul J. J.; Mello, Marco A. R.

    2012-01-01

    Food availability for forest birds is a function of habitat type, forest management regime, and season. In winter, it is also impacted by variations in the weather. In the current study we assessed the food preferences of wild bird populations in two types of forest (spruce and beech) during the months of November 2010 to April 2011 in the Schwäbische Alb Biodiversity Exploratory, south-western Germany. Our aim was to investigate whether local bird communities preferred fat-rich, carbohydrate-rich or wild fruits and to determine how forest structure, seasonality and local weather conditions affected food preferences. We found higher bird activity in beech forests for the eleven resident species. We observed a clear preference for fat-rich food for all birds in both forest types. Snow cover affected activity at food stations but did not affect food preferences. Periods of extreme low temperatures increased activity. PMID:23300878

  2. The influence of snowmobile trails on coyote movements during winter in high-elevation landscapes.

    PubMed

    Gese, Eric M; Dowd, Jennifer L B; Aubry, Lise M

    2013-01-01

    Competition between sympatric carnivores has long been of interest to ecologists. Increased understanding of these interactions can be useful for conservation planning. Increased snowmobile traffic on public lands and in habitats used by Canada lynx (Lynx canadensis) remains controversial due to the concern of coyote (Canis latrans) use of snowmobile trails and potential competition with lynx. Determining the variables influencing coyote use of snowmobile trails has been a priority for managers attempting to conserve lynx and their critical habitat. During 2 winters in northwest Wyoming, we backtracked coyotes for 265 km to determine how varying snow characteristics influenced coyote movements; 278 km of random backtracking was conducted simultaneously for comparison. Despite deep snow (>1 m deep), radio-collared coyotes persisted at high elevations (>2,500 m) year-round. All coyotes used snowmobile trails for some portion of their travel. Coyotes used snowmobile trails for 35% of their travel distance (random: 13%) for a mean distance of 149 m (random: 59 m). Coyote use of snowmobile trails increased as snow depth and penetrability off trails increased. Essentially, snow characteristics were most influential on how much time coyotes spent on snowmobile trails. In the early months of winter, snow depth was low, yet the snow column remained dry and the coyotes traveled off trails. As winter progressed and snow depth increased and snow penetrability increased, coyotes spent more travel distance on snowmobile trails. As spring approached, the snow depth remained high but penetrability decreased, hence coyotes traveled less on snowmobile trails because the snow column off trail was more supportive. Additionally, coyotes traveled closer to snowmobile trails than randomly expected and selected shallower snow when traveling off trails. Coyotes also preferred using snowmobile trails to access ungulate kills. Snow compaction from winter recreation influenced coyote movements within an area containing lynx and designated lynx habitat. PMID:24367565

  3. The Influence of Snowmobile Trails on Coyote Movements during Winter in High-Elevation Landscapes

    PubMed Central

    Gese, Eric M.; Dowd, Jennifer L. B.; Aubry, Lise M.

    2013-01-01

    Competition between sympatric carnivores has long been of interest to ecologists. Increased understanding of these interactions can be useful for conservation planning. Increased snowmobile traffic on public lands and in habitats used by Canada lynx (Lynx canadensis) remains controversial due to the concern of coyote (Canis latrans) use of snowmobile trails and potential competition with lynx. Determining the variables influencing coyote use of snowmobile trails has been a priority for managers attempting to conserve lynx and their critical habitat. During 2 winters in northwest Wyoming, we backtracked coyotes for 265 km to determine how varying snow characteristics influenced coyote movements; 278 km of random backtracking was conducted simultaneously for comparison. Despite deep snow (>1 m deep), radio-collared coyotes persisted at high elevations (>2,500 m) year-round. All coyotes used snowmobile trails for some portion of their travel. Coyotes used snowmobile trails for 35% of their travel distance (random: 13%) for a mean distance of 149 m (random: 59 m). Coyote use of snowmobile trails increased as snow depth and penetrability off trails increased. Essentially, snow characteristics were most influential on how much time coyotes spent on snowmobile trails. In the early months of winter, snow depth was low, yet the snow column remained dry and the coyotes traveled off trails. As winter progressed and snow depth increased and snow penetrability increased, coyotes spent more travel distance on snowmobile trails. As spring approached, the snow depth remained high but penetrability decreased, hence coyotes traveled less on snowmobile trails because the snow column off trail was more supportive. Additionally, coyotes traveled closer to snowmobile trails than randomly expected and selected shallower snow when traveling off trails. Coyotes also preferred using snowmobile trails to access ungulate kills. Snow compaction from winter recreation influenced coyote movements within an area containing lynx and designated lynx habitat. PMID:24367565

  4. Large-scale atmospheric flow conditions and sea surface temperatures associated with hazardous winter winds in Switzerland

    NASA Astrophysics Data System (ADS)

    Welker, Christoph; Martius, Olivia

    2014-05-01

    Strong winter storms are among the most destructive meteorological hazards in Switzerland. Hazardous winter winds in northern Switzerland since the late 19th century, identified in the Twentieth Century Reanalysis (20CR) dataset spanning 1871-present and in independent historic wind speed measurements, exhibited not only pronounced interannual variability but also statistically significant variability at decadal time scales (Welker and Martius 2013). The decadal variability has periods between about 36 and 47 years. The goal of the present study is to further our understanding of the large-scale atmospheric and sea surface temperature (SST) environment in the North Atlantic (NA) and European sectors that has contributed to the occurrence of hazardous winter winds in Switzerland. The analyses cover synoptic, interannual, and decadal time scales and are based on all ensemble members of the 20CR dataset. This work further includes a detailed analysis of the link between the hazardous winter wind variability in Switzerland and important NA and Eurasian teleconnection patterns. On the synoptic time scale, the ten strongest wind events in Switzerland are examined; on longer time scales, the variability of the winter wind loss potential (WLP) in Switzerland is investigated. The WLP is a simple measure to quantify the local loss potential associated with high wind speeds (see Welker and Martius 2013 for details). The present study finds that the ten strongest wind events in Switzerland were accompanied by an increased (decreased) surface cyclone frequency to the north (south) of Switzerland, and at upper-tropospheric levels by an eastward extension of the extratropical jet stream. The events were further associated with positive SST anomalies in the eastern NA and the Mediterranean, and positive anomalies of lower-tropospheric temperature and atmospheric moisture over Western/Central Europe. On interannual time scales, the winter WLP variability in Switzerland was accompanied by a large-scale atmospheric and SST spatial pattern similar to a southeastward displacement of the winter North Atlantic Oscillation (NAO) pattern with a zonally oriented and eastward-extended jet. The spatial pattern for the decadal-scale winter WLP variability, with periods between 36 and 47 years, is in general closer to the variability pattern of the winter NAO. At periodicities of 36-47 years the winter WLP variability in Switzerland was positively correlated with the winter NAO index variability, even though the strength and statistical significance of their co-variability varied over time. The correlations between the winter WLP in Switzerland and the winter NAO and East Atlantic pattern indices was positive for most of the period since 1950, and increased considerably with time. The distinct eastward shift of the northern node of the NAO during the winters at the end of the 20th century potentially explains the improved correlation between the winter NAO variability and the WLP. Welker C, Martius O (2013) Decadal-scale variability in hazardous winds in northern Switzerland since end of the 19th century. Atmos Sci Lett. doi:10.1002/asl2.467

  5. Vitamin D Supplementation and Immune Response to Antarctic Winter

    NASA Technical Reports Server (NTRS)

    Zwart, S. R.; Mehta, S. K.; Ploutz-Snyder, R.; Bourbeau, Y.; Locke, J. P.; Pierson, D. L.; Smith, Scott M.

    2011-01-01

    Maintaining vitamin D status without sunlight exposure is difficult without supplementation. This study was designed to better understand interrelationships between periodic cholecalciferol(vitamin D3) supplementation and immune function in Antarctic workers. The effect of 2 oral dosing regimens of vitamin D3 supplementation on vitamin D status and markers of immune function were evaluated in people in Antarctica with no ultraviolet light exposure for 6 mo. Participants were given a 2,000-IU (50 g) daily (n=15) or 10,000-IU (250 g) weekly (n=14) vitamin D3 supplement for 6 mo during a winter in Antarctica. Biological samples were collected at baseline and at 3 and 6 mo. Vitamin D intake, markers of vitamin D and bone metabolism, and latent virus reactivation were determined. After 6 mo the mean (SD) serum 25-hydroxyvitamin D3 concentration increased from 56 plus or minus 17 to 79 plus or minus 16 nmol/L and 52 plus or minus 10 to 69 plus or minus 9 nmol/L in the 2,000-IU/d and 10,000-IU/wk groups (main effect over time P less than 0.001). Participants with a greater BMI (participant BMI range = 19-43 grams per square meter) had a smaller increase in 25-hydroxyvitamin D3 after 6 mo supplementation (P less than 0.05). Participants with high serum cortisoland higher serum 25-hydroxyvitamin D3 were less likely to shed Epstein-Barr virus in saliva (P less than 0.05). The doses given raised vitamin D status in participants not exposed to sunlight for 6 mo, and the efficacy was influenced by baseline vitamin D status and BMI. The data also provide evidence that vitamin D, interacting with stress, can reduce risk of latent virus reactivation during the winter in Antarctica.

  6. Family-based winter territoriality in western bluebirds, Sialia mexicana: the structure and dynamics of winter groups.

    PubMed

    Kraaijeveld, Ken; Dickinson, Janis L.

    2001-01-01

    Winter residency is characteristic of the majority of cooperatively breeding birds, but the composition and dynamics of winter groups have been examined in relatively few. In 1996-1998, we examined winter territoriality in the western bluebird, a year-round resident that shows a limited degree of helping behaviour in central coastal California, U.S.A. In spring, most western bluebirds breed as socially monogamous pairs, but a small proportion of pairs (3-16%) have additional breeding-age males helping at the nest, usually assisting parents or brothers. We found that year-round residents commonly wintered in family groups that defended territories similar to those used in spring. Winter groups had an even sex ratio and formed early in the autumn, when hatch-year birds dispersed. More females than males left their natal groups to be replaced by an influx of immigrant hatch-year birds. Winter groups typically consisted of breeders and one or two sons from the prior breeding season along with one or more immigrant females. A second period of dispersal occurred in spring when winter groups broke up and most birds other than the breeding pair left the winter territory. When they bred, yearling males and females often bred with unrelated individuals from their winter groups. Sons were more likely to remain on the study area as yearlings when they wintered with both parents than when they wintered with just one parent. We suggest that young males stay the winter due to benefits of remaining in family groups on mistletoe-based winter territories. Subsequent localized dispersal of sons then leads to opportunistic kin-based interactions later in life. Copyright 2001 The Association for the Study of Animal Behaviour. PMID:11170701

  7. Cr. Fall Winter Spring Fall Winter Spring Cr. 14 HHS 241-248 or PAC 14

    E-print Network

    Haller, Merrick

    Spring WR 121 A-G H-N O-Z BI 101 BI 102 BI 103 MB 230 MB 230 MB 230 ANS 121 ANS 121 ANS 121 SOIL 205 SOIL 205 SOIL 205 SOIL 102 SOIL 102 BOT 101 SOIL 102 Cr. Fall Winter Spring Fall Winter Spring Cr. 1 1 2 2,W,S) Math 252E Integral Calculus (F,W,S) PH 211E Gen Physics w/Calc (F,W,S) WR 327 Technical Writing (F

  8. Temperature and Resource Availability May Interactively Affect Over-Wintering Success of Juvenile Fish in a Changing Climate

    PubMed Central

    Brodersen, Jakob; Rodriguez-Gil, José Luis; Jönsson, Mikael; Hansson, Lars-Anders; Brönmark, Christer; Nilsson, P. Anders; Nicolle, Alice; Berglund, Olof

    2011-01-01

    The predicted global warming may affect freshwater systems at several organizational levels, from organism to ecosystem. Specifically, in temperate regions, the projected increase of winter temperatures may have important effects on the over-winter biology of a range of organisms and especially for fish and other ectothermic animals. However, temperature effects on organisms may be directed strongly by resource availability. Here, we investigated whether over-winter loss of biomass and lipid content of juvenile roach (Rutilus rutilus) was affected by the physiologically relatively small (2-5°C) changes of winter temperatures predicted by the Intergovernmental Panel on Climate Change (IPCC), under both natural and experimental conditions. This was investigated in combination with the effects of food availability. Finally, we explored the potential for a correlation between lake temperature and resource levels for planktivorous fish, i.e., zooplankton biomass, during five consecutive winters in a south Swedish lake. We show that small increases in temperature (+2°C) affected fish biomass loss in both presence and absence of food, but negatively and positively respectively. Temperature alone explained only a minor part of the variation when food availability was not taken into account. In contrast to other studies, lipid analyses of experimental fish suggest that critical somatic condition rather than critical lipid content determined starvation induced mortality. Our results illustrate the importance of considering not only changes in temperature when predicting organism response to climate change but also food-web interactions, such as resource availability and predation. However, as exemplified by our finding that zooplankton over-winter biomass in the lake was not related to over-winter temperature, this may not be a straightforward task. PMID:21998627

  9. NORTHEASTERN US Increased temperature

    E-print Network

    winter sea surface/ land station temperatures vary as a result of changes in the NAO index. RED Basin is greater than usual. Blue marks regions which are cooler. Sea surface temperatures are taken and river runoff This figure shows surface temperature response and some well-documented socio

  10. Hyperspectral assessment of nitrogen nutrition for winter wheat canopy using continuum-removed method

    NASA Astrophysics Data System (ADS)

    Zhang, Xuehong; Shen, Runping; Zhu, Shanyou

    2009-10-01

    The hyperspectral reflectance of canopy of winter wheat and data of leaf nitrogen accumulation (LNA) were acquired in primary growth stages under different nitrogen levels in order to monitor winter wheat status and diagnose nitrogen using remote sensing method. A new method was developed to estimate the nitrogen nutrition of winter wheat using continuum-removed method, which generally used in spectra analysis on rock and mineral. The continuum-removed method was effectively used to magnify the object spectral absorption features, and it could be convenient to extract the spectral absorption features. Based on the continuum-removed treatment and the correlation between absorption feature parameters and LNA, results show that LNA increased with increasing the nitrogen fertilization. LNA increased from the erecting stage to the booting stage and decreases from the booting to the heading stage under all nitrogen levels. It is the VNIR regions that were sensitive to LNA. By continuum removal operation, it can be found that the method magnify the subtle difference in spectral absorption characteristics arise from the nitrogen stress on winter wheat. At all stages, total area of absorption peak, left area of absorption peak, right area of absorption peak increased with increasing the nitrogen fertilization, whereas the normalized maximal absorption depth by area decreased. The correlation analysis indicated that all the absorption characteristics parameters of continuum-removed spectra highly correlated with LNA, and the correlation relationship of the whole growth cycle was stronger than that of any single growth stage. But the booting stage is the best at the several single growth stages and the NMAD is the best absorption parameter to monitoring the nitrogen of winter wheat canopy. The range 550 nm to 760 nm are the feature bands for extracting nitrogen information of canopy. The regression analysis on the whole growth period showed that the all regression models between the absorption characteristics parameters and LNA were all extremely significant (P<0.001).Therefore, continuum-removed method is a feasible method for quantificational evaluation of winter wheat LNA.

  11. Change of Landscape Structure before and after Winter Olympic Games in Nagano City

    NASA Astrophysics Data System (ADS)

    Fujii, Yoshio; Takeda, Toshiharu

    Recently it is desirable to realize the conservation of biodiversity and to create the city with symbiosis with nature even in local city. In this study, we chose Nagano City which was the site of the Winter Olympic Games as the subject of study, investigated the change of land cover by using Landsat TM data of the year 1985 and 1999 which were before and after the Winter Olympic Games, and grasped the change of landscape structure quantitatively by using landscape indices. As a result, we obtained the following conclusions. The expansion of urban area proceeded rapidly before and after the Winter Olympic Games. The area of artificial land cover in the city planning area has increased by 57%. In the meantime the areas of upland field and paddy field have decreased by 45% and 50% respectively. Therefore, agricultural land changed into urban area remarkably. It was found that the shape of paches of paddy field and upland field especially became small and the inequality of the paches decreased before and after the Winter Olympic Games. It became clear that the fragmentation has occurred in agricultural land such as paddy field, upland field and orchard.

  12. Changes in winter conditions impact forest management in north temperate forests.

    PubMed

    Rittenhouse, Chadwick D; Rissman, Adena R

    2015-02-01

    Climate change may impact forest management activities with important implications for forest ecosystems. However, most climate change research on forests has focused on climate-driven shifts in species ranges, forest carbon, and hydrology. To examine how climate change may alter timber harvesting and forest operations in north temperate forests, we asked: 1) How have winter conditions changed over the past 60 years? 2) Have changes in winter weather altered timber harvest patterns on public forestlands? 3) What are the implications of changes in winter weather conditions for timber harvest operations in the context of the economic, ecological, and social goals of forest management? Using meteorological information from Climate Data Online and Autoregressive Integrated Moving Average (ARIMA) models we document substantial changes in winter conditions in Wisconsin, including a two- to three-week shortening of frozen ground conditions from 1948 to 2012. Increases in minimum and mean soil temperatures were spatially heterogeneous. Analysis of timber harvest records identified a shift toward greater harvest of jack pine and red pine and less harvest of aspen, black spruce, hemlock, red maple, and white spruce in years with less frozen ground or snow duration. Interviews suggested that frozen ground is a mediating condition that enables low-impact timber harvesting. Climate change may alter frozen ground conditions with complex implications for forest management. PMID:25463581

  13. Circulation during winter and northerly storm events in southern Lake Michigan

    NASA Astrophysics Data System (ADS)

    Rao, Y. R.; McCormick, M. J.; Murthy, C. R.

    2004-01-01

    Moored observations of winds, currents, and temperature made off the southeastern Lake Michigan shore during 1998 to 2000 winter-spring periods are studied to describe the mean winter circulation and episodic circulation during northerly storms in Lake Michigan. Late winter-spring sediment plumes in southeastern Lake Michigan were attributed to these episodic circulation features. The winter-spring currents in southeastern Lake Michigan are quite depth independent, and the mean currents flow predominantly alongshore and toward the north. The observed currents show the signature of a forced two-gyre circulation in the southeastern basin. The interannual variability of mean and fluctuating currents is mainly due to the variability of prevailing wind-forcing. The intermittent episodic circulation influenced by northerly storms causes significant asymmetry to the mean circulation. During northerly storm episodes, the mean current speeds increased significantly, and the currents within 10 km of shore followed the surface wind stress, while farther offshore the circulation was oppositely directed. During these episodes it is also observed that the combination of directly wind-forced currents and northward propagating vorticity wave generates significant offshore transport in this region.

  14. Use of mini-refuges by female northern pintails wintering in southwestern Louisiana

    USGS Publications Warehouse

    Cox, R.R., Jr.; Afton, A.D.

    1998-01-01

    The Gulf Coast Joint Venture of the North American Waterfowl Management Plan began contracting private agricultural lands (hereafter mini-refuges) in 1988 to expand existing sanctuaries for northern pintails (Anas acuta) in southwestern Louisiana. Previous research suggested that mini-refuges may prove more attractive to pintails than permanent, open-water pools (pools) on refuges because mini-refuges provide sanctuary and food during the day, whereas pools generally provide only sanctuary (Rave and Cordes 1993). We used radiotelemetry to compare diel use of mini-refuges and pools (Lacassine Pool and Amoco Pool) by female pintails in southwestern Louisiana during winters of 1991-1992 and 1992-1993. We examined variation in use of these areas in relation to female age (immature or adult), time period (prehunting season, first hunting season, time between split hunting seasons, second hunting season, and posthunting season), and winter (1991-1992 and 1992-1993). Diurnal use of min-refuges and pools differed among time periods, but differences were not consistent between winters. Mini-refuges accounted for <2% of diurnal use by pintails in 7 of 10 time-period and winter comparisons. Diurnal use of mini-refuges was lower than that of Lacassine Pool in 8 of 10 time-period and winter comparisons. Diurnal use of mini-refuges was lower than tha of Amoco pool during first hunting season in 1992-1993, but use of these areas did not differ within other time periods and winters. Nocturnal use of mini-refuges and pools did not differ in relation to female age, time period, winter, or individual bird. Nocturnal use of mini-refuges did not differ from that of Lacassine Pool. In contrast to predictions and findings by Rave and Cordes (1993), we found that: (1) female pintails did not use mini-refuges more than pools, and (2) female pintails used mini-refuges at night. We believe that use of mini-refuges by pintails could be increased if mini-refuges were (1) located in areas of traditionally high pintail use, (2) increased in size, (3) flooded immediately prior to hunting season, and (4) cleared of dense vegetation by rolling, disking, or burning.

  15. Pre-winter lipid stores in young-of-year Atlantic salmon along a north-south gradient.

    PubMed

    Berg, O K; Finstad, A G; Solem, Ø; Ugedal, O; Forseth, T; Niemelä, E; Arnekleiv, J V; Lohrmann, A; Naesje, T F

    2009-05-01

    The pre-winter lipid stores of young-of-the-year (YOY, age 0 year) Atlantic salmon Salmo salar were analysed along a north-south gradient from c. 71 to 58 degrees N, with winter conditions ranging from >200 days of ice cover to no ice. The rivers sampled in Northern Norway represent some of the most northerly S. salar rivers. There was an increase in lipid content with increasing latitude, and mean lipid content (size adjusted to common mass) for YOY in northern rivers were almost three times higher: 0.035 g compared to 0.013 g in southern rivers. The relationship was not sensitive to variation in sampling time or variation in YOY body size. The lipid stores, however, varied markedly between rivers and also between neighbouring rivers, indicating different strategies or opportunities for pre-winter lipid storage both at latitudinal and local scales. PMID:20735641

  16. Summer snow extent heralding of the winter North Atlantic Oscillation

    Microsoft Academic Search

    Mark A. Saunders; Budong Qian; Benjamin Lloyd-Hughes

    2003-01-01

    Winter climate over the North Atlantic and European sector is modulated by the North Atlantic Oscillation (NAO). We find that the summer extent of snow cover over northern North America and northern Eurasia 1972-2001 is linked significantly (r ˜ 0.6; p < 0.01) to the upcoming winter NAO state. Summers with high\\/low snow extent precede winters of low\\/high NAO index

  17. Evaluation of transmission line arresters against winter lightning

    Microsoft Academic Search

    Takeo Wakai; Naoki Itamoto; Tetsuya Sakai; Masaru Ishii

    2000-01-01

    The authors have tested 154 kV class transmission line arresters by installing them on an instrumented tower of a double-circuit test transmission line during winter seasons since 1993. The tower is struck by natural and artificially-triggered lightning several times during each winter season. The conventional transmission line arrester designed against summer lightning was effective against winter lightning. The authors developed

  18. Reproduction of Meloidogyne incognita on Winter Cover Crops Used in Cotton Production.

    PubMed

    Timper, Patricia; Davis, Richard F; Tillman, P Glynn

    2006-03-01

    Substantial reproduction of Meloidogyne incognita on winter cover crops may lead to damaging populations in a subsequent cotton (Gossypium hirsutum) crop. The amount of population increase during the winter depends on soil temperature and the host status of the cover crop. Our objectives were to quantify M. incognita race 3 reproduction on rye (Secale cereale) and several leguminous cover crops and to determine if these cover crops increase population densities of M. incognita and subsequent damage to cotton. The cover crops tested were 'Bigbee' berseem clover (Trifolium alexandrinum), 'Paradana' balansa clover (T. balansae), 'AU Sunrise' and 'Dixie' crimson clover (T. incarnatum), 'Cherokee' red clover (T. pratense), common and 'AU Early Cover' hairy vetch (Vicia villosa), 'Cahaba White' vetch (V. sativa), and 'Wrens Abruzzi' rye. In the greenhouse tests, egg production was greatest on berseem clover, Dixie crimson clover, AU Early Cover hairy vetch, and common hairy vetch; intermediate on Balansa clover and AU Sunrise crimson clover; and least on rye, Cahaba White vetch, and Cherokee red clover. In both 2002 and 2003 field tests, enough heat units were accumulated between 1 January and 20 May for the nematode to complete two generations. Both AU Early Cover and common hairy vetch led to greater root galling than fallow in the subsequent cotton crop; they also supported high reproduction of M. incognita in the greenhouse. Rye and Cahaba White vetch did not increase root galling on cotton and were relatively poor hosts for M. incognita. Only those legumes that increased populations of M. incognita reduced cotton yield. In the southern US, M. incognita can complete one to two generations on a susceptible winter cover crop, so cover crops that support high nematode reproduction may lead to damage and yield losses in the following cotton crop. Planting rye or Meloidogyne-resistant legumes as winter cover crops will lower the risk of increased nematode populations compared to most vetches and clovers. PMID:19259434

  19. Reproduction of Meloidogyne incognita on Winter Cover Crops Used in Cotton Production

    PubMed Central

    Timper, Patricia; Davis, Richard F.; Tillman, P. Glynn

    2006-01-01

    Substantial reproduction of Meloidogyne incognita on winter cover crops may lead to damaging populations in a subsequent cotton (Gossypium hirsutum) crop. The amount of population increase during the winter depends on soil temperature and the host status of the cover crop. Our objectives were to quantify M. incognita race 3 reproduction on rye (Secale cereale) and several leguminous cover crops and to determine if these cover crops increase population densities of M. incognita and subsequent damage to cotton. The cover crops tested were ‘Bigbee’ berseem clover (Trifolium alexandrinum), ‘Paradana’ balansa clover (T. balansae), ‘AU Sunrise’ and ‘Dixie’ crimson clover (T. incarnatum), ‘Cherokee’ red clover (T. pratense), common and ‘AU Early Cover’ hairy vetch (Vicia villosa), ‘Cahaba White’ vetch (V. sativa), and ‘Wrens Abruzzi’ rye. In the greenhouse tests, egg production was greatest on berseem clover, Dixie crimson clover, AU Early Cover hairy vetch, and common hairy vetch; intermediate on Balansa clover and AU Sunrise crimson clover; and least on rye, Cahaba White vetch, and Cherokee red clover. In both 2002 and 2003 field tests, enough heat units were accumulated between 1 January and 20 May for the nematode to complete two generations. Both AU Early Cover and common hairy vetch led to greater root galling than fallow in the subsequent cotton crop; they also supported high reproduction of M. incognita in the greenhouse. Rye and Cahaba White vetch did not increase root galling on cotton and were relatively poor hosts for M. incognita. Only those legumes that increased populations of M. incognita reduced cotton yield. In the southern US, M. incognita can complete one to two generations on a susceptible winter cover crop, so cover crops that support high nematode reproduction may lead to damage and yield losses in the following cotton crop. Planting rye or Meloidogyne-resistant legumes as winter cover crops will lower the risk of increased nematode populations compared to most vetches and clovers. PMID:19259434

  20. What Is a Mild Winter? Regional Differences in Within-Species Responses to Climate Change

    PubMed Central

    Vetter, Sebastian G.; Ruf, Thomas; Bieber, Claudia; Arnold, Walter

    2015-01-01

    Climate change is known to affect ecosystems globally, but our knowledge of its impact on large and widespread mammals, and possibly population-specific responses is still sparse. We investigated large-scale and long-term effects of climate change on local population dynamics using the wild boar (Sus scrofa L.) as a model species. Our results show that population increases across Europe are strongly associated with increasingly mild winters, yet with region-specific threshold temperatures for the onset of exponential growth. Additionally, we found that abundant availability of critical food resources, e.g. beech nuts, can outweigh the negative effects of cold winters on population growth of wild boar. Availability of beech nuts is highly variable and highest in years of beech mast which increased in frequency since 1980, according to our data. We conclude that climate change drives population growth of wild boar directly by relaxing the negative effect of cold winters on survival and reproduction, and indirectly by increasing food availability. However, region-specific responses need to be considered in order to fully understand a species’ demographic response to climate change. PMID:26158846

  1. Trend changes of African airmass intrusions in the marine boundary layer over the subtropical Eastern North Atlantic region in winter

    NASA Astrophysics Data System (ADS)

    Alonso-Perez, S.; Cuevas, E.; Perez, C.; Querol, X.; Baldasano, J. M.; Draxler, R.; de Bustos, J. J.

    2011-04-01

    African dust intrusions in the marine mixing layer of the Eastern North Atlantic subtropical region (23.5°N to 35°N) are favoured in winter when the eastern edge of the Azores High covers Southwestern Europe and North Africa. In situ ground pressure observations and reanalysis from National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) and European Centre for Medium-Range Weather Forecasts (ECMWF) indicate that the Azores High has strengthened and shifted eastward in winter over the last three decades. This is evidenced by the increase over time of the Madrid-Tenerife Index which is defined as the geopotential height anomaly difference at 1000 mb between Tenerife (28.5°N; 16.3°W) and Madrid (40.5°N; 3.5°W) in winter and of the African Index which is defined as the residence time over Africa of air mass trajectories entering the subtropical Eastern North Atlantic Ocean. Barcelona Supercomputing Center/Dust Regional Atmospheric Model (BSC-DREAM) dust regional model simulations from 1958 to 2006 were performed, assuming that the soil characteristics of dust sources remained unchanged over time. Simulated winter dust concentration levels are well correlated (0.67) with the available background observations for the 1998-2004 period. The model results show a two-fold increase in winter dust concentrations over the 1980-2006 period with respect to the 1958-1979 period, corresponding to the strengthening and eastward shift of the Azores High.

  2. Physiological processes during winter dormancy and their ecological significance

    SciTech Connect

    Havranek, W.M.; Tranquillini, W.

    1995-07-01

    Lengthy and severe winters require that trees in the forests of boreal and mountain zones undergo winter dormancy. Physiologically, a high resistance to subfreezing temperatures and concomitant dehydration are necessary. To accomplish this dormancy, both physiological and structural changes are needed at the cellular level that require induction by endogenous and photoperiodic control early in autumn. Endogenous rhythmicity promotes cold hardening in early autumn and the persistence of hardiness throughout the winter. Numerous physiological functions are maintained at a reduced level, or become completely inhibited during true winter dormancy. Winter hardiness also includes the capability to minimize water loss effectively when water uptake is severely impeded or impossible. Anatomical features such as tracheids act to minimize xylem embolism during frequent freeze-thaw cycles, and {open_quotes}crown{close_quotes} tissues enable buds to stay in a dehydrated and, thus, more resistant state during winter. Both these structural features are adaptations that contribute to the dominance of conifers in cold climates. Interestingly, deciduous tree species rather than evergreen conifers dominate in the most severe winter climates, although it is not clear whether limitations during winter, during the summer growth period, or during both are most limiting to conifer tree ecology. Additional work that evaluates the importance of winter and summer growth restriction, and their interaction, is needed before a comprehensive understanding of conifer tree ecophysiology will be possible.

  3. Math 152: Linear Systems Winter 2004 1: Vectors and Geometry

    E-print Network

    Jellinek, Mark

    Math 152: Linear Systems ­ Winter 2004 1: Vectors and Geometry Vectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Description of points and the geometry of solutions to systems of equations

  4. Physical Properties of Normal Grade Biodiesel and Winter Grade Biodiesel

    PubMed Central

    Sadrolhosseini, Amir Reza; Moksin, Mohd Maarof; Nang, Harrison Lau Lik; Norozi, Monir; Yunus, W. Mahmood Mat; Zakaria, Azmi

    2011-01-01

    In this study, optical and thermal properties of normal grade and winter grade palm oil biodiesel were investigated. Surface Plasmon Resonance and Photopyroelectric technique were used to evaluate the samples. The dispersion curve and thermal diffusivity were obtained. Consequently, the variation of refractive index, as a function of wavelength in normal grade biodiesel is faster than winter grade palm oil biodiesel, and the thermal diffusivity of winter grade biodiesel is higher than the thermal diffusivity of normal grade biodiesel. This is attributed to the higher palmitic acid C16:0 content in normal grade than in winter grade palm oil biodiesel. PMID:21731429

  5. Family-based winter territoriality in western bluebirds, Sialia mexicana: the structure and dynamics of winter groups

    Microsoft Academic Search

    Ken Kraaijeveld; Janis L. Dickinson

    2001-01-01

    Winter residency is characteristic of the majority of cooperatively breeding birds, but the composition and dynamics of winter groups have been examined in relatively few. In 1996–1998, we examined winter territoriality in the western bluebird, a year-round resident that shows a limited degree of helping behaviour in central coastal California, U.S.A. In spring, most western bluebirds breed as socially monogamous

  6. Forage radish winter cover crop suppresses winter annual weeds in fall and before corn planting

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Forage radish (Raphanus sativus L. var. longipinnatus) is a new winter cover crop in the Mid-Atlantic region. The objective of this project was to characterize the repeatability, amount, and duration of weed suppression during and after a fall-planted forage radish cover crop and to quantify the sub...

  7. Habitat Suitability Index Models: Lesser Scaup (Wintering)

    USGS Publications Warehouse

    Mulholland, Rosemarie

    1985-01-01

    A review and synthesis of existing information were used to develop a model for evaluating wintering habitat quality for the lesser scaup (Aythya affinis). The model is scaled to produce an index of habitat suitability between 0.0 (unsuitable habitat) to 1.0 (optimal habitat) for Southern Atlantic and Gulf of Mexico coastal areas of the continental United States. Habitat suitability indices are designed for use with the Habitat Evaluation Procedures previously developed by the U.S. Fish and Wildlife Service Guidelines for model application and techniques for measuring model variables are provided.

  8. Redshifts of galaxies in the winter plane

    NASA Technical Reports Server (NTRS)

    Michel, April; Huchra, John

    1988-01-01

    New redshifts for 57 bright galaxies and 98 fainter galaxies in the winter galactic plane are presented. This list completes the redshifts for all galaxies in the merged Zwicky-Nilson catalog between 4 h and 8 h right ascension, above declination 0 deg, and with m(pg) of 14.5 or less. Three other bright objects in the Zwicky-Nilson catalog suspected to be galaxies are found to be a planetary nebula, an open galactic star cluster, and a reflection nebula.

  9. Echo Meadows Project Winter Artificial Recharge.

    SciTech Connect

    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 found that this water can be timed to return to the river during the desired time of the year (summer to early fall). This is because the river stage, which remains relatively high until this time, drops during the irrigation season-thereby releasing the stored groundwater and increasing river flows. A significant side benefit is that these enhanced groundwater return flows will be clean and cold, particularly as compared to the Umatilla River. We also believe that this same type of application of water could be done and the resulting stream flows could be realized in other watersheds throughout the Pacific Northwest. This means that it is critical to compare the results from this baseline report to the full implementation of the project in the next phase. As previously stated, this report only discusses the results of data gathered during the baseline phase of this project. We have attempted to make the data that has been gathered accessible with the enclosed databases and spreadsheets. We provide computer links in this report to the databases so that interested parties can fully evaluate the data that has been gathered. However, we cannot emphasize too strongly that the real value of this project is to implement the phases to come, compare the results of these future phases to this baseline and develop the science and strategies to successfully implement this concept to other rivers in the Pacific Northwest. The results from our verified and calibrated groundwater model matches the observed groundwater data and trends collected during the baseline phase. The modeling results indicate that the return flows may increase to their historic values with the addition of 1 acre-ft/acre of recharge water to the groundwater system (about 9,600 acre-feet total). What this means is that through continued recharge project, you can double to quadruple the annual baseflow of the Umatilla River during the low summer and fall flow periods as compared to the present base-flow. The cool and high quality recharge water is a significant beneficial impact to the river system.

  10. NGA/ACT Pilot Project: Increasing Course Rigor. Final Report

    ERIC Educational Resources Information Center

    ACT, Inc., 2008

    2008-01-01

    The Increasing Course Rigor Pilot Project, a joint initiative of the National Governors Association (NGA) Center for Best Practices and ACT, Inc., is one component of Phase Two of the NGA Center for Best Practices Honor States Grant Program. The project, which began in winter 2006 and concluded in summer 2007, was designed to improve the quality…

  11. Recent winter floods in Germany caused by changes in the atmospheric circulation across Europe

    Microsoft Academic Search

    H. J. Caspary

    1995-01-01

    Instationarity of the time series of annual peak discharge is demonstrated for the Enz River Basin\\/Black Forest, and the upper Danube Basin in Germany. The reason for this is a dramatic increase in frequency and persistence of the large-scale atmospheric circulation type “West cyclonic” (Wz) in winter (Dec.- Feb.). During the observation period (1926–1995) nearly all extreme flood events in

  12. Evaluation of herbicides to manage herbicide-resistant corn poppy ( Papaver rhoeas) in winter cereals

    Microsoft Academic Search

    J. Torra; A. Cirujeda; A. Taberner; J. Recasens

    2010-01-01

    Corn poppy is the most important broad-leaved weed in winter cereals in southern Europe. It is an increasing problem due to the appearance of herbicide-resistant biotypes. Experiments were conducted in north-eastern Spain with three corn poppy populations to determine the level of resistance to 2,4-D and tribenuron using seed-germination tests. Field experiments were conducted at sites from where the tested

  13. Selenium Concentrations in Greater Scaup and Dreissenid Mussels During Winter on Western Lake Ontario

    Microsoft Academic Search

    L. L. WareS; S. A. Petrie; S. S. Badzinski; R. C. Bailey

    2011-01-01

    One hypothesis for the decline of the North American greater (Aythya marila) and lesser (A. affinis) scaup population is that contaminant burdens acquired on wintering or staging areas impair reproduction or cause lethal\\u000a or sublethal health effects. Recent studies have found increased selenium (Se) concentrations in scaup but have focused on\\u000a the fall and spring staging periods. From January to

  14. Influence of Mowing Artemisia tridentata ssp. wyomingensis on Winter Habitat for Wildlife

    Microsoft Academic Search

    Kirk W. Davies; Jonathan D. Bates; Dustin D. Johnson; Aleta M. Nafus

    2009-01-01

    Mowing is commonly implemented to Artemisia tridentata ssp. wyomingensis (Beetle & A. Young) S.L. Welsh (Wyoming big sagebrush) plant communities to improve wildlife habitat, increase forage production\\u000a for livestock, and create fuel breaks for fire suppression. However, information detailing the influence of mowing on winter\\u000a habitat for wildlife is lacking. This information is crucial because many wildlife species depended on

  15. Patterns and dynamics of rest-phase hypothermia in wild and captive blue tits during winter

    Microsoft Academic Search

    Andreas Nord; Johan F. Nilsson; Maria I. Sandell; Jan-Åke Nilsson

    2009-01-01

    We evaluated biotic and abiotic predictors of rest-phase hypothermia in wintering blue tits (Cyanistes caeruleus) and also assessed how food availability influences nightly thermoregulation. On any given night, captive blue tits (with\\u000a unrestricted access to food) remained largely homeothermic, whereas free-ranging birds decreased their body temperature (T\\u000a b) by about 5°C. This was not an effect of increased stress in

  16. The impacts of climate change on the winter hardiness zones of woody plants in Europe

    NASA Astrophysics Data System (ADS)

    Gloning, Philipp; Estrella, Nicole; Menzel, Annette

    2013-08-01

    In this study, we investigated how global climate change will affect winter minimum temperatures and if, as a consequence, potential species ranges will expand or contract. Thus, Heinze and Schreiber's 1984 winter hardiness zones (WHZ) for woody plants in Europe, which are based on mean annual minimum temperatures, were updated and analyzed for recent and future changes using the ENSEMBLES data set E-OBS for recent climate and CLM-model data based on two emission scenarios (A1B and B1) for future simulated climate. For the different data sets, maps of the WHZ were created and compared. This allowed the assessment of projected changes in the development of the WHZ until the end of the twenty-first century. Our results suggested that, depending on the emission scenario used, the main shifts in the WHZ will occur for zones 8 and 9 (increase), located in Mediterranean regions, and for zone 5 (decrease), a boreal zone. Moreover, up to 85 % of the area analyzed will experience a warmer winter climate during the twenty-first century, and some areas will experience increases in two WHZ, equal to an increase of 5.6-11 °C in the mean annual minimum temperature. The probabilities of absolute minimum winter temperatures for four 30-year time periods from 1971 to 2100 were calculated in order to reveal changes associated with a general increase in temperature as well as shifts in the distribution itself. It was predicted that colder temperatures than indicated by the WHZ will occur less frequently in the future, but, depending on the region, reoccur every 5-50 years. These findings are discussed in the context of woody plant species assigned to each of the WHZ by Roloff and Bärtels (1996), with respect to a possible expansion of their range limits and the altered risk of recurring cold spells.

  17. Winter climate impacts of historical deforestation in New England

    NASA Astrophysics Data System (ADS)

    Burkakowski, Elizabeth Ann

    Deforestation in the New England region of the United States peaked around 1850, with almost 50% of the total land area cleared for pasture, lumber and timber, agriculture, and home heating. Farmland abandonment in the late-1800's led to reforestation and today New England is the most forested region in the US. This dissertation explores the hypothesis that mid-1800's deforestation led to cooler winters for two reasons: (1) increased surface albedo, a measure of surface reflectivity, and (2) decreased surface roughness length. Three chapters detail: a scaling approach to assess accuracy of albedo over forested and deforested landscapes in New Hampshire (Chapter I); the establishment of a volunteer albedo observer network to characterize albedo over deforested landscapes (Chapter II); and the validation of a regional climate model to simulate historical climate responses to deforestation (Chapter III). The results from Chapter I and II provide essential validation data for the regional climate model in Chapter III. The scaling approach shows that albedo over deforested lands is underestimated at wavelengths less than 450 nm and that tower-, airborne-, and satellite-based albedo over forests are relatively consistent across spatial scales. The regional climate model overestimates the albedo of snow-covered deciduous broadleaf forests, which may be a strong contributor to cold biases in November through January maximum temperature (TMAX) identified in the climate model. The modeling approach suggests that mid-1800's deforestation resulted in daytime cooling in the New England region. The impact on nighttime temperatures remains unclear because the model was not able to capture observed nighttime cooling patterns associated with surface roughness and atmospheric stability over open lands. 1 conclude that mid-1800's deforestation in New England contributed to cooler winters, however the magnitude of cooling at night requires improvements to snow-surface coupling in the regional climate model.

  18. Winter precipitation change in South China in recent decades

    NASA Astrophysics Data System (ADS)

    Cai, Jingning

    2013-04-01

    Precipitation change is one of important climate researches in China, but winter precipitation variation in South China has not been studied so frequently. In China, it is rainy when hot; so summer precipitation is usually one focus in research, esp. in South China. However, winter precipitation and its change influence people profoundly in South China, also. The most recent example is what happened over South China in winter 2008. In this winter, millions of people suffered from the unusual cold and snowy winter. It led to huge loss in economy and traffic as well. Roads closed and railway stations were jammed and crowded with people; many planes were grounded for heavy snow and bad weather. Transmission lines faulted in the mountains. The ommunication signals were affected. Everyday food supply including vegetables and meats had to be delayed or interrupted. In some city even water supply was interrupted. And garbage in the city was piled up. Just in this winter the snow depth and coverage area in many places in South China broke or equaled the historical records. In fact, it isn't the only one unusual winter precipitation event in South China. Since 1950s, several freezing and snowy winters struck the South in China. In this research, winter precipitation change in recent years in South China has been discussed based on the precipitation observations. The associated large scale atmospheric circulation change is also analyzed. It is found that snowy winter in South China hardly comes in most periods of 2000s, but in recent decades this heavy snow in winter has appeared several times as observations shows. This phenomenon could be related to the large scale atmospheric circulation change.

  19. Increase in liver pigmentation during natural hibernation in some amphibians

    PubMed Central

    BARNI, SERGIO; BERTONE, VITTORIO; CROCE, ANNA CLETA; BOTTIROLI, GIOVANNI; BERNINI, FRANCO; GERZELI, GIUSEPPE

    1999-01-01

    The amount/distribution of liver melanin in 3 amphibian species (Rana esculenta, Triturus a. apuanus, Triturus carnifex) was studied during 2 periods of the annual cycle (summer activity–winter hibernation) by light and electron microscopy, image analysis and microspectrofluorometry. The increase in liver pigmentation (melanin content) during winter appeared to be correlated with morphological and functional modifications in the hepatocytes, which at this period were characterised by a decrease in metabolic activity. These findings were interpreted according to the functional role (e.g. phagocytosis, cytotoxic substance inactivation) played by the pigment cell component in the general physiology of the heterothermic vertebrate liver and, in particular, in relation to a compensatory engagement of these cells against hepatocellular hypoactivity during the winter period. PMID:10473289

  20. Differential migration and an endocrine response to stress in wintering dark-eyed juncos (Junco hyemalis).

    PubMed Central

    Holberton, R L; Able, K P

    2000-01-01

    The dark-eyed junco (junco hyemalis) exhibits differential migration in autumn that, in general, results in females overwintering south of males, and young within each sex overwintering north of older birds. Individuals overwintering at higher latitudes face less predictable and more challenging environmental conditions. Rapid increases in circulating levels of the energy-regulating glucocorticosteroid, corticosterone, occur in response to environmental stressors. To establish whether the strength of acute corticosterone secretion was correlated with the probability of encountering poor environmental conditions, we compared the corticosterone stress response (e.g. initial plasma concentrations at the time of capture and 30 min later) in dark-eyed juncos overwintering in Mississippi (MS), USA, near the southern limit of their wintering range, with juncos overwintering in New York (NY), USA, near the northern limit of their wintering range. During two winters, 22 males and one female were sampled in NY; 13 males, 12 females and one bird of undetermined sex were sampled in MS. Not unexpectedly, NY birds carried greater fat reserves that resulted in a significantly higher value of energetic condition (mass corrected for wing cord cubed). There was no difference between the two winters sampled at either site, nor was there an effect of sex on patterns of corticosterone secretion in MS birds. With sexes pooled, MS and NY birds had similar baseline corticosterone levels. However, as predicted, NY birds exhibited significantly higher corticosterone concentrations 30 min after capture. These results support the hypothesis that birds wintering in less predictable, more extreme environments show a higher amplitude corticosterone response, which may enable them to adjust their behaviour and physiology more rapidly in response to environmental stressors such as storms. Adrenocortical sensitivity may be a part of the physiological milieu associated with differential migration in juncos; whether it results from endogenous differences in the migratory programmes of individuals or from acclimatization to local environmental conditions remains to be determined. PMID:11052541