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1

Impact of declining Arctic sea ice on winter snowfall  

PubMed Central

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

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

2012-01-01

2

Dust Activity during Winter Time in East Asia and Snowfall Obervations and Simulations in Taiwan  

NASA Astrophysics Data System (ADS)

Taiwan has relatively frequent snowfall in mountain during winter among regions of the same latitude. The phenomenon is contributed by Taiwan's unique topography - high and steep mountains, and geographical location - sitting on the route the continental polar air mass travels from its birthplace to the ocean, contribute to this phenomenon. Snow occurence, in addition to the freezing-point temperature, when two requirements are met: sufficient vapor and the condensation nuclei in the air. This study pursues the causes of the snowfall activity in Taiwan, the relations between the East Asian dust aerosol and the snowfall activity in Taiwan, and the impacts the climate changes have on the snowfall activity in Taiwan. In this study, Yushan snowfall activity from 1995~2011 and related atmosphere circulations were examined using SYNOP data, NCEP/DOE reanalysis atmospheric data, the observations of the Central Weather Bureau's Yushan Weather Station and the Taiwan Air Quality Monitoring Network of the Environment Protect Administration, Executive Yuan. To provide a quantitative measure of snowfall events and dust activity, a snowfall activity index (SAI) and the DAI Index by Yu et al. (2010) were defined. The time series of yearly SAI and DAI show that East Asian dust storm activity and Taiwan snowfall marked interannual variations during 1995 ~ 2011. For active years such as 2008, 2010, and 2011, SAI was hundreds of times larger than that for inactive years such as 1996, 1999 and 2003; and DAI in active years such as 2001 and 2002 was several tens of times larger than that in inactive years such as 1997 and 2003. In active years when the EAT (East Asian Trough) was shifted eastward, the strength of WPH (West Pacific High) increased in the south and an anticyclone thus occurred. This anticyclone introduced anomalous southwesterly flows along the southeastern coast of mainland China and over Taiwan, resulting in a wetter-than-normal atmosphere in support of snowfall. Oppositely, for inactive years, drier-than-normal atmosphere appeared and consequently sluggish snowfall seasons followed. A SVD (singular value decomposition) analysis of the Asian synoptic circulation indicated that the connection between the pressure dipoles and the position of EAT is strong in 1998, 1999, 2001, 2002, 2003, 2010, and 2011. It significantly affects both of the snowfall and dust activities. In summary, snowfall active years usually occurred when the East Asian dust storm was inactive. Nevertheless, the snowfall activity increased in Taiwan if there was dust event and the dust aerosol successfully transported to Taiwan. This finding is also demonstrated in the model simulation of this study.

Tsai, L.

2013-12-01

3

Winter Snowfall Turns an Emerald White  

NASA Technical Reports Server (NTRS)

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

2001-01-01

4

Snowfall increases future ice discharge from Antarctica  

NASA Astrophysics Data System (ADS)

Future sea level rise is one of the major impacts of anthropogenic climate change. While enhanced snowfall over Antarctica as projected in regional as well as global climate models constitutes a comparably certain negative future contribution to global sea level, the largest uncertainty arises from the dynamic ice discharge from Antarctica. Here we show that these two processes are not independent, but that future ice discharge is enhanced up to three times due to additional snowfall under global warming. The effect exceeds that of surface warming as well as that of basal ice-shelf melting and is due to the difference in surface elevation change caused by snowfall on grounded and floating ice. As a result of their dynamic similarity, the ratio between basal-melt-induced- and snowfall-induced ice loss is relatively independent of the specific representation of the transition zone. In an ensemble of simulations, capturing ice-physics uncertainty, the additional dynamic ice loss along the coastline compensates between 30 and 65% of the ice gain due to enhanced snowfall over the entire continent. The reported effect thus strongly counters a potential negative contribution to global sea level by the Antarctic Ice Sheet.

Winkelmann, R.; Levermann, A.; Martin, M. A.; Frieler, K.

2012-12-01

5

Changes in winter snowfall/precipitation ratio in the contiguous United States  

NASA Astrophysics Data System (ADS)

The precipitation falling as rain or snow has different impact on regional water resources and their annual distribution. Shift from solid to liquid form of precipitation following the increase of the surface air temperatures could be quite important because such change could influence the timing of spring runoff and cause water shortage in summer. In this study, the ratio of snowfall to precipitation (S/P) for November-March in the contiguous United States is analyzed and temperature effects on the changes of S/P are examined for 1949-2005. Major results show that the S/P ratio has been decreasing strongly in the Pacific Northwest and the central United States. The S/P decreased slightly in the eastern United States. In the Pacific Northwest, the changes of S/P are attributed to decrease of both snowfall and precipitation with snowfall decreasing at a greater rate. In the central United States, decrease of the S/P ratio resulted primarily from the decrease of snowfall and increase of the winter precipitation. Averaged over the contiguous United States, the changes of S/P are mainly related to the changes of the snowfall and with little effect from changes of winter precipitation. Decreases of the S/P ratio are largest in March and least in January. The significant decreases of the S/P ratio are associated with large increase in mean winter wet-day temperatures in the western and central United States. Weak warming in the eastern United States concurred with weak and no change of S/P.

Feng, Song; Hu, Qi

2007-08-01

6

Increased future ice discharge from Antarctica owing to higher snowfall  

NASA Astrophysics Data System (ADS)

Anthropogenic climate change is likely to cause continuing global sea-level rise, but some processes within the Earth system may mitigate the magnitude of the projected effect. Regional and global climate models simulate enhanced snowfall over Antarctica, which would provide a direct offset of the future contribution to global sea level rise from cryospheric mass loss and ocean expansion. Uncertainties exist in modelled snowfall, but even larger uncertainties exist in the potential changes of dynamic ice discharge from Antarctica. Here we show that snowfall and discharge are not independent, but that future ice discharge will increase by up to three times as a result of additional snowfall under global warming. Our results, based on an ice-sheet model forced by climate simulations through to the end of 2500, show that the enhanced discharge effect exceeds the effect of surface warming as well as that of basal ice-shelf melting, and is due to the difference in surface elevation change caused by snowfall on grounded versus floating ice. Although different underlying forcings drive ice loss from basal melting versus increased snowfall, similar ice dynamical processes are nonetheless at work in both; therefore results are relatively independent of the specific representation of the transition zone. In an ensemble of simulations designed to capture ice-physics uncertainty, the additional dynamic ice loss along the coastline compensates between 30 and 65 per cent of the ice gain due to enhanced snowfall over the entire continent. This results in a dynamic ice loss of up to 1.25 metres in the year 2500 for the strongest warming scenario.

Winkelmann, Ricarda; Levermann, Anders; Martin, Maria A.; Frieler, Katja

2013-04-01

7

Increased future ice discharge from Antarctica owing to higher snowfall.  

PubMed

Anthropogenic climate change is likely to cause continuing global sea level rise, but some processes within the Earth system may mitigate the magnitude of the projected effect. Regional and global climate models simulate enhanced snowfall over Antarctica, which would provide a direct offset of the future contribution to global sea level rise from cryospheric mass loss and ocean expansion. Uncertainties exist in modelled snowfall, but even larger uncertainties exist in the potential changes of dynamic ice discharge from Antarctica and thus in the ultimate fate of the precipitation-deposited ice mass. Here we show that snowfall and discharge are not independent, but that future ice discharge will increase by up to three times as a result of additional snowfall under global warming. Our results, based on an ice-sheet model forced by climate simulations through to the end of 2500 (ref. 8), show that the enhanced discharge effect exceeds the effect of surface warming as well as that of basal ice-shelf melting, and is due to the difference in surface elevation change caused by snowfall on grounded versus floating ice. Although different underlying forcings drive ice loss from basal melting versus increased snowfall, similar ice dynamical processes are nonetheless at work in both; therefore results are relatively independent of the specific representation of the transition zone. In an ensemble of simulations designed to capture ice-physics uncertainty, the additional dynamic ice loss along the coastline compensates between 30 and 65 per cent of the ice gain due to enhanced snowfall over the entire continent. This results in a dynamic ice loss of up to 1.25 metres in the year 2500 for the strongest warming scenario. The reported effect thus strongly counters a potential negative contribution to global sea level by the Antarctic Ice Sheet. PMID:23235878

Winkelmann, R; Levermann, A; Martin, M A; Frieler, K

2012-12-13

8

Synoptic Mechanisms Associated with Snowfall Increases to the Lee of Lakes Erie and Ontario  

NASA Astrophysics Data System (ADS)

Snowfall is a cyrospheric variable that impacts nearly every sector of society. Because of its societal importance, snowfall is a logical variable to be used as an indicator of potential global environmental change. This study investigates the mechanisms responsible for large observed snowfall increases across the eastern Great Lakes region of the USA. Results indicate that mean snowfall amounts across sections of western New York and north-western Pennsylvania have increased by up to 100 cm over the 60-year period encompassing the snowfall seasons 1930-1931 through to 1989-1990. A synoptic climatological approach is utilized to identify consistent synoptic-scale atmospheric patterns responsible for snowfall across the region. Nine synoptic types are identified as producing significan t snowfall in the study area; five with synoptic characteristics indicative of lake-effect snowfall and four evidencing characteristics of snowfall associated with cyclonic influence.An examination of the seasonal frequency of the nine synoptic types indicates a substantial increase in the frequency of the five lake-effect synoptic types and a long-term decrease in the numbers of cyclone synoptic types over the period 1950-1951 through to 1981-1982. Information concerning trends in the frequency and the intensity of each of the nine snowfall-producing synoptic types was combined to produce a modelled snowfall change due to frequency and intensity variations over the period. Trends in the frequency and intensity of the synoptic patterns associated with lake- effect snowfall explain the majority of the observed snowfall increase across the region. Variations in the synoptic types associated with cyclonically induced snowfall are shown to be unimportant to snowfall changes across the eastern Great Lakes area. Possible reasons for increases in the frequency and the intensity of the lake-effect synoptic types are discussed.

Leathers, Daniel J.; Ellis, Andrew W.

1996-10-01

9

Winter snowfall and summer photosynthesis for the Great Basin Desert shrubs Artemisia tridentata and Purshia tridentata.  

NASA Astrophysics Data System (ADS)

Snowfall provides the majority of soil water recharge in many western high-elevation North American ecosystems, but climate change may alter the magnitude and timing of snowfall and snow melt events thereby affecting ecosystem processes. Experiments were conducted to test hypotheses about multi-scale linkages of antecedent snow depth variation with soil water content and physiological performance of deeply-rooted shrubs in the western Great Basin Desert. Snow depth was manipulated using eight 50-year old snow fences near Mammoth Lakes, California, USA. Water potential and photosynthetic gas exchange were measured annually in early summer (1 - 2 mo following snowmelt), between 2004 and 2008 for Artemisia tridentata (Asteraceae) and Purshia tridentata (Rosaceae) on plots with increased ("+ snow"), decreased ("- snow") and ambient snow depth. Seasonal patterns were measured from May - September 2005, and four to five months after snowmelt in wet and dry years. Snow depth on +snow plots was about twice that of ambient-depth plots in most years. Depth was about 20% lower on -snow plots. Soil water content in May on +snow plots was roughly double that on ambient and 220% of that on -snow plots. Water potential patterns varied across daily, seasonal, and annual scales, but only on a few occasions was there a significant snow-depth effect. Stomatal conductance (gs) and CO2 assimilation (A) increased for several months after snowmelt in 2005, but there were only a few times when there was a snow depth effect. Photosynthetic gas exchange reflected inter-annual snow depth, but the magnitude of the variation was lower. There was a threshold response of A to October 1 - June 1 cumulative precipitation. For A. tridentata, A differed as a function of Snow Water Equivalents (SWE) across five years of measurements. Results suggest that plant water relations for these two deeply-rooted shrub species are resilient to variation in winter snow depth and subsequent spring soil water availability, and instantaneous photosynthesis may be more influenced by temperature and VPD.

Loik, M. E.; Griffith, A. B.; Alpert, H.; Concilio, A. L.; Martinson, S. J.

2011-12-01

10

Increasing Great Lake-Effect Snowfall during the Twentieth Century: A Regional Response to Global Warming?  

Microsoft Academic Search

The influence of the Laurentian Great Lakes on the climate of surrounding regions is significant, especially in leeward settings where lake-effect snowfall occurs. Heavy lake-effect snow represents a potential natural hazard and plays important roles in winter recreational activities, agriculture, and regional hydrology. Changes in lake-effect snowfall may represent a regional-scale manifestation of hemispheric-scale climate change, such as that associated

Adam W. Burnett; Matthew E. Kirby; Henry T. Mullins; William P. Patterson

2003-01-01

11

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

12

Projected changes in snowfall extremes and interannual variability of snowfall in the western United States  

NASA Astrophysics Data System (ADS)

Projected warming will have significant impacts on snowfall accumulation and melt, with implications for water availability and management in snow-dominated regions. Changes in snowfall extremes are confounded by projected increases in precipitation extremes. Downscaled climate projections from 20 global climate models were bias-corrected to montane Snowpack Telemetry stations across the western United States to assess mid-21st century changes in the mean and variability of annual snowfall water equivalent (SFE) and extreme snowfall events, defined by the 90th percentile of cumulative 3 day SFE amounts. Declines in annual SFE and number of snowfall days were projected for all stations. Changes in the magnitude of snowfall event quantiles were sensitive to historical winter temperature. At climatologically cooler locations, such as in the Rocky Mountains, changes in the magnitude of snowfall events mirrored changes in the distribution of precipitation events, with increases in extremes and less change in more moderate events. By contrast, declines in snowfall event magnitudes were found for all quantiles in warmer locations. Common to both warmer and colder sites was a relative increase in the magnitude of snowfall extremes compared to annual SFE and a larger fraction of annual SFE from snowfall extremes. The coefficient of variation of annual SFE increased up to 80% in warmer montane regions due to projected declines in snowfall days and the increased contribution of snowfall extremes to annual SFE. In addition to declines in mean annual SFE, more frequent low-snowfall years and less frequent high-snowfall years were projected for every station.

Lute, A. C.; Abatzoglou, J. T.; Hegewisch, K. C.

2015-02-01

13

Simulated CO2 Snowfalls and Baroclinic Waves in the Northern Winter Polar Atmosphere on Mars: Feasibility of Forecasts  

NASA Astrophysics Data System (ADS)

The seasonal CO2 polar cap is formed from ice particles that have fallen from the atmosphere as well as those condensed directly on the surface. The possible occurrence of CO2 snowfall in the winter polar regions have been observed, and previous simulation studies have indicated that the longitudinal irregularities of CO2 ice clouds in the northern polar region seemed to be linked to local weather phenomena. Transient planetary waves are the prominent dynamical feature during northern winters in the martian atmosphere, and this study focuses on revealing the mechanism of how the dynamical influence of transient planetary waves affects the occurrences of CO2 ice clouds, snowfalls and formations of seasonal CO2 polar cap in high latitudes during northern winters. The DRAMATIC (Dynamics, RAdiation, MAterial Transport and their mutual InteraCtions) MGCM, which is used for this study, is based on a Japanese terrestrial model (CCSR/NIES/FRCGC MIROC) with a spectral solver for the three-dimensional primitive equations. In this simulation the horizontal resolution is set at about 5.6 5.6 (~333 km at equator), the vertical grid consists of 69 ?-levels with the top of the model at about 100 km. Realistic topography, albedo, thermal inertia and roughness data for the Mars surface are included. Radiative effects of CO2 gas (considering only LTE) and dust, in solar and infrared wavelengths, are taken into account. We have implemented a simple scheme representing the formation and transport of CO2 ice clouds into our MGCM, and investigated snowfall in high latitudes during northern winters. The MGCM simulations showed that the CO2 ice clouds are formed at altitudes of up to ~40 km in the northern polar region (northward of 70 N) during winter, which is consistent with the observations (MRO-MCS and MGS-MOLA). In addition, we found that the occurrence of the CO2 ice clouds correlated to a large degree with the cold phases of transient planetary waves. In the altitudes above ~15 km, the cloud formations are very much aligned with the baroclinic waves with zonal wavenumber of 1 and 5-6 sols period. In the lower altitudes the baroclinic waves components with shorter periods (~3 sols) also affect the cloud formations. The fate of ice particles during sedimentation depends on the thermal structure below because it takes ~0.2 sols for particles to descend from 25 km to the surface, which is much shorter than the periods of the transient waves. We found that ice particles formed up to ~20 km can reach the surface in the form of snowfall in certain longitude regions (in 30 W-60 E), while in others these particles likely sublimate in the lower warmer atmospheric layers. Given the regular nature of such atmospheric waves on Mars, the results of this study suggest that the snowstorms may be predicted several weeks in advance. It is simply impossible to predict the snowfall somewhere on Earth in such a long time ahead, but this may be different on Mars. For missions to Mars aiming to explore these regions with rovers, such weather forecasts would offer the possibility of choosing a route that avoids heavy snow storms.

Kuroda, T.; Medvedev, A. S.; Kasaba, Y.; Hartogh, P.

2013-12-01

14

Spatial and Temporal Trends of Snowfall in Central New York - A Lake Effect Dominated Region  

NASA Astrophysics Data System (ADS)

Central New York is located in one of the snowiest regions in the United States, with the city of Syracuse, New York the snowiest metropolis in the nation. Snowfall in the region generally begins in mid-November and lasts until late-March. Snow accumulation occurs from a multitude of conditions: frontal systems, mid-latitude cyclones, Nor'easters, and most notably lake-effect storms. Lake effect snowfall (LES) is a difficult parameter to forecast due to the isolated and highly variable nature of the storm. Consequently, studies have attempted to determine changes in snowfall for lake-effect dominated regions. Annual snowfall patterns are of particular concern as seasonal snowfall totals are vital for water resources, winter businesses, agriculture, government and state agencies, and much more. Through the use of snowfall, temperature, precipitation, and location data from the National Weather Service's Cooperative Observer Program (COOP), spatial and temporal changes in snowfall for Central New York were determined. In order to determine climatic changes in snowfall, statistical analyses were performed (i.e. least squares estimation, correlations, principal component analyses, etc.) and spatial maps analyzed. Once snowfall trends were determined, factors influencing the trends were examined. Long-term snowfall trends for CNY were positive for original stations (0.46 +/- 0.20 in. yr -1) and homogenously filtered stations (0.23 +/- 0.20 in. yr -1). However, snowfall trends for shorter time-increments within the long-term period were not consistent, as positive, negative, and neutral trends were calculated. Regional differences in snowfall trends were observed for CNY as typical lake-effect areas (northern counties, the Tug Hill Plateau and the Southern Hills) experienced larger snowfall trends than areas less dominated by LES. Typical lake-effect months (December - February) experienced the greatest snowfall trend in CNY compared to other winter months. The influence of teleconnections on seasonal snowfall in CNY was not pronounced; however, there was a slight significant (5%) correlation (< 0.35) with the Atlantic Multidecadal Oscillation. It was not clear if changes in air temperature or changes in precipitation were the cause of variations in snowfall trends. It was also inconclusive if the elevation or distance from Lake Ontario resulted in increased snowfall trends. Results from this study will aid in seasonal snowfall forecasts in CNY, which can be used to predict future snowfall. Even though the study area is regionally specific, the methods may be applied to other lake effect dominated areas to determine temporal and spatial variations in snowfall. This study will enhance climatologists and operational forecasters' awareness and understanding of snowfall, especially lake effect snowfall in CNY.

Hartnett, Justin Joseph

15

Influences of Arctic Oscillation and Madden-Julian Oscillation on cold surges and heavy snowfalls over Korea: A case study for the winter of 20092010  

Microsoft Academic Search

In the winter of 20092010, frequent and long-lasting cold weather affected Korea. Four major cold surges and several heavy snowfall events were observed, including a record-breaking event on 4 January 2010. These four cold surges had distinct properties with regard to their relationships to the phases of the Arctic Oscillation (AO) and the Madden-Julian Oscillation (MJO), suggesting the possible influences

Tae-Won Park; Chang-Hoi Ho; Song Yang; Jee-Hoon Jeong

2010-01-01

16

Comparisons of Snowfall Measurements in Complex Terrain Made During the 2010 Winter Olympics in Vancouver  

NASA Astrophysics Data System (ADS)

Solid precipitation (SP) intensity () using four automatic gauges, Pluvio, PARSIVEL (PArticle, SIze and VELocity), FD12P and POSS, and radar reflectivity factor () using the POSS and PARSIVEL were measured at a naturally sheltered station (VOA) located at high level (1,640 m) on the Whistler Mountain in British Colombia, Canada. The R s and other standard meteorological parameters were collected from March 2009, and from November 2009, to February 2010. The wind speed (ws) measured during this period ranged from 0 to 4.5 ms-1, with a mean value of 0.5 ms-1. The temperature varied from 4 to -17 C. The SP amount reported by the PARSIVEL was higher than that reported by the Pluvio by more than a factor of 2, while the FD12P and POSS measured relatively smaller amounts, but much closer to that reported by the Pluvio and manual measurements. The dependence of R s from the PARSIVEL on wind speed was examined, but no significant dependence was found. The PARSIVEL's precipitation retrieval algorithm was modified and tested using three different snow density size relationships ( ? s- D) reported in literature. It was found that after modification of the algorithm, the derived R s amounts using the raw data agreed reasonably well with the Pluvio. Statistical analysis shows that more than 95 % of data measured by POSS appears to correlates well with the reflectivity factors determined using the three ? s- D relationships. The automated Pluvio accumulation and manually determined daily SP amount (SPm) measured during five winter months were compared. The mean ratio (MR) and the mean difference (MD), and the correlation coefficient ( r) calculated using the data collected using the two methods, were found to be 0.96, 0.4 and 0.6 respectively, indicating respectable agreement between these two methods, with only the Pluvio underestimating the amount by about 4 %.

Boudala, Faisal S.; Isaac, George A.; Rasmussen, Roy; Cober, Stewart G.; Scott, Bill

2014-01-01

17

Snowfall Rate Retrieval Using Passive Microwave Measurements and Its Applications in Weather Forecast and Hydrology  

NASA Technical Reports Server (NTRS)

(AMSU), Microwave Humidity Sounder (MHS) and Advance Technology Microwave Sounder (ATMS). ATMS is the follow-on sensor to AMSU and MHS. Currently, an AMSU and MHS based land snowfall rate (SFR) product is running operationally at NOAA/NESDIS. Based on the AMSU/MHS SFR, an ATMS SFR algorithm has also been developed. The algorithm performs retrieval in three steps: snowfall detection, retrieval of cloud properties, and estimation of snow particle terminal velocity and snowfall rate. The snowfall detection component utilizes principal component analysis and a logistic regression model. It employs a combination of temperature and water vapor sounding channels to detect the scattering signal from falling snow and derives the probability of snowfall. Cloud properties are retrieved using an inversion method with an iteration algorithm and a two-stream radiative transfer model. A method adopted to calculate snow particle terminal velocity. Finally, snowfall rate is computed by numerically solving a complex integral. The SFR products are being used mainly in two communities: hydrology and weather forecast. Global blended precipitation products traditionally do not include snowfall derived from satellites because such products were not available operationally in the past. The ATMS and AMSU/MHS SFR now provide the winter precipitation information for these blended precipitation products. Weather forecasters mainly rely on radar and station observations for snowfall forecast. The SFR products can fill in gaps where no conventional snowfall data are available to forecasters. The products can also be used to confirm radar and gauge snowfall data and increase forecasters' confidence in their prediction.

Meng, Huan; Ferraro, Ralph; Kongoli, Cezar; Yan, Banghua; Zavodsky, Bradley; Zhao, Limin; Dong, Jun; Wang, Nai-Yu

2015-01-01

18

Role of extreme snowfall events in interannual variability of snowfall accumulation in the western United States  

NASA Astrophysics Data System (ADS)

Water resources in the western United States are contingent on interannual variations in snowpack. Interannual snowpack variability has been attributed to large-scale climate patterns including the El Nio-Southern Oscillation (ENSO), however, the contribution of snowfall frequency and extreme snowfall events to this variability are less well quantified. Long-term records from Snowpack Telemetry and Cooperative Observer Program stations in the 11 western states were used to investigate these relationships by considering the number of snowfall days and snowfall water equivalent (SFE) of extreme snowfall events. The top decile of snowfall events contributed 20-38% of annual SFE, depending on the region. An average of 65% and 69% of the interannual variability in annual SFE was explained by snowfall days and SFE of top decile snowfall events, respectively, with extreme events being a more significant predictor at most stations. The latitudinal dipole in SFE during ENSO phases results from changes in snowfall frequency and extreme events. In the Pacific Northwest, above normal SFE during La Nia winters was a product of both larger contributions from extremes and more snowfall days, while below normal SFE during El Nio winters was primarily associated with a substantial reduction in extremes. Conversely, annual SFE during ENSO phases in the mountains of Arizona was more closely linked to fluctuations in snowfall days than extremes. Results indicate the importance of extreme snowfall events in shaping interannual variability in water resources and suggest that improved predictive ability may inform better water resource management now and in the coming decades.

Lute, A. C.; Abatzoglou, J. T.

2014-04-01

19

Contrasting responses of mean and extreme snowfall to climate change.  

PubMed

Snowfall is an important element of the climate system, and one that is expected to change in a warming climate. Both mean snowfall and the intensity distribution of snowfall are important, with heavy snowfall events having particularly large economic and human impacts. Simulations with climate models indicate that annual mean snowfall declines with warming in most regions but increases in regions with very low surface temperatures. The response of heavy snowfall events to a changing climate, however, is unclear. Here I show that in simulations with climate models under a scenario of high emissions of greenhouse gases, by the late twenty-first century there are smaller fractional changes in the intensities of daily snowfall extremes than in mean snowfall over many Northern Hemisphere land regions. For example, for monthly climatological temperatures just below freezing and surface elevations below 1,000metres, the 99.99th percentile of daily snowfall decreases by 8% in the multimodel median, compared to a 65% reduction in mean snowfall. Both mean and extreme snowfall must decrease for a sufficiently large warming, but the climatological temperature above which snowfall extremes decrease with warming in the simulations is as high as -9C, compared to -14C for mean snowfall. These results are supported by a physically based theory that is consistent with the observed rain-snow transition. According to the theory, snowfall extremes occur near an optimal temperature that is insensitive to climate warming, and this results in smaller fractional changes for higher percentiles of daily snowfall. The simulated changes in snowfall that I find would influence surface snow and its hazards; these changes also suggest that it may be difficult to detect a regional climate-change signal in snowfall extremes. PMID:25164753

O'Gorman, Paul A

2014-08-28

20

Sunspots and Snowfall  

ERIC Educational Resources Information Center

Examination of the snowfall and total precipitation data for Rochester, New York, suggests a correlation with sunspot activity. Data from other locations tend to support the thesis, but the ability to predict yearly snowfall or total precipitation amounts from sunspot activity has yet to be developed. (Author/CP)

Starr, Richard R.

1978-01-01

21

Sensitivity of soil respiration and microbial communities to altered snowfall Zachary T. Aanderud a,1  

E-print Network

snow-covered ecosystems Seed banks Sub-zero conditions Winter CO2 ux a b s t r a c t Winter respirationSensitivity of soil respiration and microbial communities to altered snowfall Zachary T. Aanderud a in winter soil respiration may be in uenced by the effects of snowfall on microbial communities

Fierer, Noah

22

Characteristics of large snowfall events in the montane western United States as examined using snowpack telemetry (SNOTEL) data  

NASA Astrophysics Data System (ADS)

Daily snow water equivalent records from the snowpack telemetry archive are used to assess spatiotemporal characteristics of large snowfall events over the montane western United States. The largest mean annual (leading) events are found in the Pacific Northwest and Sierra Nevada. The mean leading event lasting up to 72 hours typically accounts for 10-23% of the water equivalent of annual snowfall, with the largest contribution in the Arizona/New Mexico sector. For most of the West, snowfall events in the top quartile of station distributions are most common during midwinter, but those for the Rocky Mountain states and Utah are more common during late winter or spring. Colorado also shows a secondary peak in large events during November. Large midwinter snowfall events in the marine sectors, Idaho, and Arizona/New Mexico are spatially coherent in that when observed at one station, they tend to occur at surrounding stations. Large events are less spatially coherent for drier inland regions. When annual snowfall is anomalously positive, there tends to be an increase in the number of snow days as well as a shift in the distributions toward the larger event sizes. Opposite relationships are observed for negative annual snowfall anomalies. These findings are in accord with recent studies using lower elevation data, demonstrating that the probability of extreme precipitation events is altered during El Nino or La Nina conditions.

Serreze, Mark C.; Clark, Martyn P.; Frei, Allan

2001-03-01

23

A Snowfall Impact Scale Derived from Northeast Storm Snowfall Distributions  

Microsoft Academic Search

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

Paul J. Kocin; Louis W. Uccellini

2004-01-01

24

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

NASA Astrophysics Data System (ADS)

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.

Vries, Hylke; Lenderink, Geert; Meijgaard, Erik

2014-06-01

25

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. ...

26

Increasing Sun Protection in Winter Outdoor Recreation  

PubMed Central

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

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

2009-01-01

27

Unusually cold and dry winters increase mortality in Australia.  

PubMed

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

Huang, Cunrui; Chu, Cordia; Wang, Xiaoming; Barnett, Adrian G

2015-01-01

28

A Snowfall Impact Scale Derived from Northeast Storm Snowfall Distributions.  

NASA Astrophysics Data System (ADS)

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).

Kocin, Paul J.; Uccellini, Louis W.

2004-02-01

29

Increasing sowing depth to reduce mouse damage to winter crops  

Microsoft Academic Search

Plagues of house mice (Mus domesticus) can cause severe economic damage to grain crops in southern Australia when their populations peak at sowing of winter-growing crops in autumn. Mice damage crops by locating and digging out newly sown seeds. If damage is high, farmers have to re-sow their crop. A trial was conducted to examine the effect of increasing sowing

Peter R Brown; Grant R Singleton; Colin R Tann; Ivan Mock

2003-01-01

30

Arctic warming, increasing snow cover and widespread boreal winter cooling.  

NASA Astrophysics Data System (ADS)

The global climate models predict that temperatures will warm the greatest in winter due to a positive feedback of increased greenhouse gases (GHGs) and a diminished and darker cryosphere. Furthermore, current consensus on global climate change predicts warming trends over the NH continents during boreal winter. However, recent trends in Northern Hemisphere (NH) seasonal surface temperatures diverge from these projections. For the last two decades, NH landmasses have experienced significant warming trends for all seasons except winter, when large-scale cooling trends exist instead. We propose a mechanism linking Arctic warming and winter continental cooling. Evidence suggests that summer and autumn Arctic warming trends are concurrent with increases in high-latitude moisture and an increase in autumnal Eurasian snow cover, which dynamically induces large-scale wintertime cooling. Understanding this counterintuitive response to radiative warming of the climate system has the potential to improve climate predictions at seasonal and longer timescales. We will also compare the trend analysis with the NAM to trend analysis with varying sea surface temperatures associated with El Nino/Southern Oscillation, the Pacific Decadal Oscillation, the Atlantic Multidecadal Oscillation, solar variability and diminishing Arctic sea ice.

Cohen, J.; Furtado, J.; Barlow, M.; Alexeev, V.; Cherry, J.

2012-04-01

31

An evaluation of the Wyoming gauge system for snowfall measurement  

USGS Publications Warehouse

The Wyoming snow fence (shield) has been widely used with precipitation gauges for snowfall measurement at more than 25 locations in Alaska since the late 1970s. This gauge's measurements have been taken as the reference for correcting wind-induced gauge undercatch of snowfall in Alaska. Recently, this fence (shield) was tested in the World Meteorological Organization Solid Precipitation Measurement Intercomparison Project at four locations in the United States of America and Canada for six winter seasons. At the Intercomparison sites an octagonal vertical Double Fence with a Russian Tretyakov gauge or a Universal Belfort recording gauge was installed and used as the Intercomparison Reference (DFIR) to provide true snowfall amounts for this intercomparison experiment. The intercomparison data collected were compiled at the four sites that represent a variety of climate, terrain, and exposure. On the basis of these data sets the performance of the Wyoming gauge system for snowfall observations was carefully evaluated against the DFIR and snow cover data. The results show that (1) the mean snow catch efficiency of the Wyoming gauge compared with the DFIR is about 80-90%, (2) there exists a close linear relation between the measurements of the two gauge systems and this relation may serve as a transfer function to adjust the Wyoming gauge records to obtain an estimate of the true snowfall amount, (3) catch efficiency of the Wyoming gauge does not change with wind speed and temperature, and (4) Wyoming gauge measurements are generally compatible to the snowpack water equivalent at selected locations in northern Alaska. These results are important to our effort of determining true snowfall amounts in the high latitudes, and they are also useful for regional hydrologic and climatic analyses.

Yang, D.; Kane, D.L.; Hinzman, L.D.; Goodison, B.E.; Metcalfe, J.R.; Louie, P.Y.T.; Leavesley, G.H.; Emerson, D.G.; Hanson, C.L.

2000-01-01

32

The North Atlantic Oscillation: Impact on Snowfall Conditions in the Northeastern U.S  

NASA Astrophysics Data System (ADS)

The North Atlantic Oscillation (NAO) is one of the main components of atmospheric circulation variability within the middle and high latitudes of the Northern Hemisphere, particularly impacting winter weather patterns in northeastern United States. Previous research has indicated greater snowfall totals and higher frequency of snowfall days in the Northeast during a NAO negative phase due to repeated polar outbreaks; yet, the NAO positive phase has also been associated with extreme snowfall events in this region. This study examines the relationship between the NAO and winter (December - February) snowfall totals in northeastern U.S. between 1961 and 2010. Two case studies of recent winter events with differing NAO phases were evaluated to provide insight on how both NAO phases can produce significant snowfall in portions of the Northeast. The analysis revealed an inverse relationship between the NAO phase and seasonal snowfall, with positive (negative) NAO index years associated with lower (higher) average snowfall and snowfall days. Significantly greater snowfall during the NAO negative phase was mainly located along the East Coast as well as the interior southern half of the study region. A composite analysis of various tropospheric variables (e.g., 500-hPa heights) showed NAO negative years produced greater snowfall due to more extreme weather conditions affecting the Northeast, such as below normal sea level pressure, a deepened mid-tropospheric trough and weaker upper-level westerlies that permitted more frequent polar outbreaks. The intrusion of cold polar air into the interior U.S. generates more extreme temperature gradients and produces snowfall farther south than the NAO positive phase. In addition, the eastward displacement of the storms in the NAO negative phase along with the available moisture from the Atlantic Ocean creates more snowfall along the East Coast. These results correspond to the spatial distribution of snowfall that occurred during the February 2010 winter storms that produced significant snowfall throughout most of the Northeast, particularly around the mid-Atlantic. On the other hand, stations indicating no relationship between NAO and snowfall were mainly located in western and central New York, northern Vermont, and Maine. These regions of the Northeast correspond to those that receive snowfall in either NAO phase, as exhibited in the case studies, due to the effects of nearby lakes and higher terrain related to the storm tracks through these areas. Winter storms track over this northern region (of the Northeast) regardless of NAO phase whereas snowfall in the mid-Atlantic states is more dependent on a strong southerly track (i.e. Cape Hatteras/Nor'easter low) associated with the NAO negative phase. Since western New York and northwestern Pennsylvania border Lake Ontario and Lake Erie, the stations in these regions commonly receive lake-effect snow as a result of great fetch due to the west-east orientation of both lakes. Stations in central and northern New York receive lake-effect snow as additional lift is generated when the moist air reaches the Allegheny Plateau and the Adirondack Mountains.

Budikova, D.; Widen, H.; Coleman, J. S.

2013-12-01

33

Climatological characterization of wind and snowfall in Minnesota and assessing the impacts of living snow fences  

NASA Astrophysics Data System (ADS)

Blowing and drifting snow on roadways is a common occurrence in Minnesota due to the topographic, vegetative, and winter climate characteristics of this area. Through proper road design and the use of snow fences this problem can be alleviated, however snowfall and wind climatological information must first be analyzed. Archived climatological records for locations in Minnesota were recently compiled. Snowfall time series data show a statistically significant increase of 28cm in the annual total since 1890. The increase is shown to occur for November--December while February and March show a decrease. This increase is largely due to an increase in the frequency of snow events less than 10cm. Wind data from federal observing sites in Minnesota show a correlation to landscape variability, with a high frequency of higher wind speeds in western and southern Minnesota. A snow relocation factor needed to quantify seasonal snow transport was calculated and shows a strong dependence on the wind speed distribution. A case study of the 2000--01 winter season allowed for examination of snow storage and agricultural implications of three living snow fence designs in southern Minnesota (two 8-row strips of corn, twin-row honeysuckle, single-row honeysuckle/red cedar). For a winter with high seasonal snowfall and spring rainfall, results of snow storage and modeled seasonal snow transport show good agreement for the two corn row strips. However, snow storage totaled approximately 50% of the modeled snow transport for the honeysuckle fence designs, which appeared to reach storage capacity prior to the end of the snow season. A key factor is the absence of a bottom gap, which promotes leeward displacement of the downwind drift and prevents snow deposition on the fence. Soil temperature and frost depth data show a moderation in temperatures and a decrease in freezing depth with an increase in associated snowpack depth. Post-season soil moisture shows no significant variability with respect to over-winter snowpack due to the anomalous rainfall received during and after snowmelt. Finally, crop yield samples show a 6%--36% reduction adjacent to the fence, but also show a relatively quick recovery.

Shulski, Martha Elizabeth Durr

34

Decreased winter severity increases viability of a montane frog population.  

PubMed

Many proximate causes of global amphibian declines have been well documented, but the role that climate change has played and will play in this crisis remains ambiguous for many species. Breeding phenology and disease outbreaks have been associated with warming temperatures, but, to date, few studies have evaluated effects of climate change on individual vital rates and subsequent population dynamics of amphibians. We evaluated relationships among local climate variables, annual survival and fecundity, and population growth rates from a 9-year demographic study of Columbia spotted frogs (Rana luteiventris) in the Bitterroot Mountains of Montana. We documented an increase in survival and breeding probability as severity of winter decreased. Therefore, a warming climate with less severe winters is likely to promote population viability in this montane frog population. More generally, amphibians and other ectotherms inhabiting alpine or boreal habitats at or near their thermal ecological limits may benefit from the milder winters provided by a warming climate as long as suitable habitats remain intact. A more thorough understanding of how climate change is expected to benefit or harm amphibian populations at different latitudes and elevations is essential for determining the best strategies to conserve viable populations and allow for gene flow and shifts in geographic range. PMID:20421473

McCaffery, Rebecca M; Maxell, Bryce A

2010-05-11

35

Decreased winter severity increases viability of a montane frog population  

PubMed Central

Many proximate causes of global amphibian declines have been well documented, but the role that climate change has played and will play in this crisis remains ambiguous for many species. Breeding phenology and disease outbreaks have been associated with warming temperatures, but, to date, few studies have evaluated effects of climate change on individual vital rates and subsequent population dynamics of amphibians. We evaluated relationships among local climate variables, annual survival and fecundity, and population growth rates from a 9-year demographic study of Columbia spotted frogs (Rana luteiventris) in the Bitterroot Mountains of Montana. We documented an increase in survival and breeding probability as severity of winter decreased. Therefore, a warming climate with less severe winters is likely to promote population viability in this montane frog population. More generally, amphibians and other ectotherms inhabiting alpine or boreal habitats at or near their thermal ecological limits may benefit from the milder winters provided by a warming climate as long as suitable habitats remain intact. A more thorough understanding of how climate change is expected to benefit or harm amphibian populations at different latitudes and elevations is essential for determining the best strategies to conserve viable populations and allow for gene flow and shifts in geographic range. PMID:20421473

McCaffery, Rebecca M.; Maxell, Bryce A.

2010-01-01

36

Wintering range expansion and increase of sika deer in Nikko in relation to global warming  

Microsoft Academic Search

This paper analyzes the expansion of sika deer (Cervus nippon) wintering ground in relation to global warming in Nikko, central Honshu, Japan. The sika wintering ground of 1993-1994 expanded toward snowy areas compared to that of 1980-1982, and the sika density increased both in new and traditional wintering grounds. Information on snow accumulation and winter deer distribution was collected by

Yuchun Li; Naoki Maruyama; Masaaki Koganezawa; Nobuo Kanzaki

1996-01-01

37

Extreme snowfall events in the western United States: Variability, change, and implications for water resource management  

NASA Astrophysics Data System (ADS)

In the western United States, seasonal snow accumulation largely determines water resource availability. Natural climate variability and anthropogenic climate change present challenges to water managers who must distribute a highly allocated water supply to satisfy many competing objectives. Extreme snowfall events are found to contribute 20-38% of annual snowfall water equivalent (SFE) and shape nearly 70% of interannual variability in annual SFE on average. By midcentury, increasing temperatures are projected to decrease the size of extreme snowfall events and the portion of annual SFE contributed by these events. Projected increases in the interannual variability of extreme snowfall events are expected to enhance interannual variability in annual SFE, resulting in less and more variable snowfall in the future. We present a SFE analysis tool that utilizes the strong relationships between annual SFE and extreme events to provide probabilistic guidance for seasonal SFE forecasts.

Lute, Abigail C.

38

Declining summer snowfall in the Arctic: causes, impacts and feedbacks  

NASA Astrophysics Data System (ADS)

Recent changes in the Arctic hydrological cycle are explored using in situ observations and an improved atmospheric reanalysis data set, ERA-Interim. We document a pronounced decline in summer snowfall over the Arctic Ocean and Canadian Archipelago. The snowfall decline is diagnosed as being almost entirely caused by changes in precipitation form (snow turning to rain) with very little influence of decreases in total precipitation. The proportion of precipitation falling as snow has decreased as a result of lower-atmospheric warming. Statistically, over 99% of the summer snowfall decline is linked to Arctic warming over the past two decades. Based on the reanalysis snowfall data over the ice-covered Arctic Ocean, we derive an estimate for the amount of snow-covered ice. It is estimated that the area of snow-covered ice, and the proportion of sea ice covered by snow, have decreased significantly. We perform a series of sensitivity experiments in which inter-annual changes in snow-covered ice are either unaccounted for, or are parameterized. In the parameterized case, the loss of snow-on-ice results in a substantial decrease in the surface albedo over the Arctic Ocean, that is of comparable magnitude to the decrease in albedo due to the decline in sea ice cover. Accordingly, the solar input to the Arctic Ocean is increased, causing additional surface ice melt. We conclude that the decline in summer snowfall has likely contributed to the thinning of sea ice over recent decades. The results presented provide support for the existence of a positive feedback in association with warming-induced reductions in summer snowfall.

Screen, James A.; Simmonds, Ian

2012-06-01

39

Microwave signatures of snowfall using a combined modeling and multi-instrument observational approach  

NASA Astrophysics Data System (ADS)

Microwave snowfall retrievals have received increased attention in recent years due to the upcoming launch of the joint NASA/JAXA Global Precipitation Measurement (GPM) mission. GPM's core satellite will feature a dual-frequency Ku/Ka-band radar and multi-frequency passive microwave radiometer that will provide the first combined active/passive microwave observations of snowfall at higher latitudes. This study initially explores a GPM proxy observational dataset comprised of coincident CloudSat, AMSR-E, and higher frequency MHS microwave observations associated with frozen precipitation to illustrate the microwave scattering signature of different snowfall events. Multi-frequency microwave signatures of deeper, synoptic snowfall events will be compared to shallow, convective lake-effect snow events to illustrate the complexity of using scattering signatures for snowfall retrievals. Additionally, recent modeling work has highlighted potentially unique triple-frequency radar signatures of snowfall using non-spherical aggregate snowflake models. These modeling results will constrain the snowflake scattering properties, while the observational dataset will be used to assess multi-frequency microwave simulations using aggregate snowflake models. Particular attention will be focused on snowfall events with low columnar cloud liquid water contents to better isolate the scattering effects of frozen hydrometeors.

Kulie, M.; Hiley, M.; Bennartz, R.

2011-12-01

40

When Elk are Excluded, Aspen Growth Dramatically Increases  

USGS Multimedia Gallery

Climate change in the form of reduced snowfall in mountains is causing powerful and cascading shifts in montane plant and bird communities through the increased ability of elk to stay at high elevations over winter and consume plants. Here,you can see an example of the difference in aspe...

41

An indoor public space for a winter city  

E-print Network

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 ...

Crane, Justin Fuller

2005-01-01

42

A climatology of snowfall-temperature relationships in Canada  

Microsoft Academic Search

A better understanding of potential climate change impacts on the global hydrological cycle requires knowledge of the interaction between air temperature and water in its various forms. One important example is the effect of air temperature on snowfall. Proper parameterization of the snowfall-temperature relationship in climate models is essential for accurate prediction of future snowfall changes that might arise from

Robert E. Davis; Michael B. Lowit; Paul C. Knappenberger; David R. Legates

1999-01-01

43

The snowfall chemistry collector intercomparison test (SCCIT)  

Microsoft Academic Search

The Snowfall Chemistry Collector Intercomparison Test (SCCIT) took place as part of a field experiment of the PRocessing of Emissions by Clouds and Precipitation (PRECP) program during January and February 1986 in western New York. SCCIT compared the chemical composition and equivalent water depth of snow collected with a large, bag-lined can (used by the PRECP community for a concurrent

D. L. Sisterson; J. D. Shannon; P. H. Daum; P. J. Klotz; D. J. Luecken; D. J. Hall

1989-01-01

44

Production System Techniques to Increase Nitrogen Use Efficiency in Winter Wheat  

Microsoft Academic Search

Most current research on winter wheat (Triticum aestivum L.) focuses on increasing yields of either grain or plant biomass. Increased production costs and environmental awareness will promote the development of methods to increase the efficiency of applied nutrients. Nitrogen (N) is often the most limiting nutrient for cereal grain production and represents one of the highest input costs in agricultural

W. E. Thomason; W. R. Raun; G. V. Johnson; K. W. Freeman; K. J. Wynn; R. W. Mullen

2002-01-01

45

Effects of Snowfall on Drifting Snow and Wind Structure Near a Surface  

NASA Astrophysics Data System (ADS)

Wind-tunnel and numerical experiments were performed to investigate the effects of snowfall on the wind profile and the development of drifting snow. Wind profiles and mass-flux profiles of drifting snow were measured with and without artificial snowfall over a snow surface within the tunnel. Wind and shear-stress profiles and the impact speeds of the snowflakes during snowfall were also investigated numerically. During snowfall, snowflakes transfer part of their horizontal momentum to the air, which increases the stress close to the snow surface; however, the resultant modifications of the wind profiles are small. Because snowflakes have large momentum, the decomposed snow crystals that result from their collision with a surface can form a saltation layer, even over a hard snow surface where entrainment of the grains from the surface does not occur. Additionally, during snowfall, the threshold friction velocity can be lower than the impact threshold because snowflake fragmentation facilitates snow drifting. The broken crystals contribute to the increase in the number of drifting snow grains, even below the impact threshold.

Nemoto, Masaki; Sato, Takeshi; Kosugi, Kenji; Mochizuki, Shigeto

2014-09-01

46

Microbial response to increasing temperatures during winter in arable soils  

NASA Astrophysics Data System (ADS)

Climate scenarios predict increasing temperatures and higher precipitation rates in late fall to early spring, both holding the potential to modify carbon and nutrient dynamics in soils by altering snow pack thickness and soil frost events. When soils are frozen, a small amount of unfrozen water allows microorganisms to remain active at temperatures down to -10 C. We carried out a field experiment on the microbial use of maize straw. We compared soils of two different clay contents and used latitude as a proxy for climate. Microcosms with sieved soil were mixed with chopped maize leaf straw (C/N 17) at a rate of 1 mg C g-1 dry soil, un-amended microcosms served as control. Results indicated that C-mineralization rates were independent from clay content. However, the microbial use of maize derived nitrogen was only increased in the soil with 13% clay compared to 33% clay in the other soil. Microbial responses to climate changes can be expected to be very specific due to characteristics of the soil and/or the location.

Lukas, Stefan; Potthoff, Martin; Joergensen, Rainer Georg

2014-05-01

47

Snowfall Rate Retrieval using NPP ATMS Passive Microwave Measurements  

NASA Technical Reports Server (NTRS)

Passive microwave measurements at certain high frequencies are sensitive to the scattering effect of snow particles and can be utilized to retrieve snowfall properties. Some of the microwave sensors with snowfall sensitive channels are Advanced Microwave Sounding Unit (AMSU), Microwave Humidity Sounder (MHS) and Advance Technology Microwave Sounder (ATMS). ATMS is the follow-on sensor to AMSU and MHS. Currently, an AMSU and MHS based land snowfall rate (SFR) product is running operationally at NOAA/NESDIS. Based on the AMSU/MHS SFR, an ATMS SFR algorithm has been developed recently. The algorithm performs retrieval in three steps: snowfall detection, retrieval of cloud properties, and estimation of snow particle terminal velocity and snowfall rate. The snowfall detection component utilizes principal component analysis and a logistic regression model. The model employs a combination of temperature and water vapor sounding channels to detect the scattering signal from falling snow and derive the probability of snowfall (Kongoli et al., 2014). In addition, a set of NWP model based filters is also employed to improve the accuracy of snowfall detection. Cloud properties are retrieved using an inversion method with an iteration algorithm and a two-stream radiative transfer model (Yan et al., 2008). A method developed by Heymsfield and Westbrook (2010) is adopted to calculate snow particle terminal velocity. Finally, snowfall rate is computed by numerically solving a complex integral. The ATMS SFR product is validated against radar and gauge snowfall data and shows that the ATMS algorithm outperforms the AMSU/MHS SFR.

Meng, Huan; Ferraro, Ralph; Kongoli, Cezar; Wang, Nai-Yu; Dong, Jun; Zavodsky, Bradley; Yan, Banghua; Zhao, Limin

2014-01-01

48

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

NASA Astrophysics Data System (ADS)

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 (RCP 8.5), 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 m. 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.

Viste, E.; Sorteberg, A.

2015-01-01

49

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

NASA Astrophysics Data System (ADS)

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 810C and specifically cold pool around 12 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 20C 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 15C. 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.

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

2014-08-01

50

Analysis of a snowfall event produced by mountains waves in Guadarrama Mountains (Spain)  

NASA Astrophysics Data System (ADS)

Heavy snowfall events are fairly uncommon precipitation processes in the Iberian Peninsula. When large amounts of snow accumulate in large cities with populations that are unaccustomed to or unprepared for heavy snow, these events have a major impact on their daily activities. On 16 January 2013, an extreme snowstorm occurred in Guadarrama Mountains (Madrid, Spain) during an experimental winter campaign as a part of the TECOAGUA Project. Strong northwesterly winds, high precipitation and temperatures close to 0C were detected throughout the whole day. During this episode, it was possible to continuously take measurements of different variables involved in the development of the convection using a multichannel microwave radiometer (MMWR). The significant increase in the cloud thickness observed vertically by the MMWR and registered precipitation of 43 mm in 24 hours at the station of Navacerrada (Madrid) led us to consider that we were facing an episode of strong winter convection. Images from the Meteosat Second Generation (MSG) satellite suggested that the main source of the convection was the formation of mountain waves on the south face of the Guadarrama Mountains. The event was simulated in high resolution using the WRF mesoscale model, an analysis of which is based on the observational simulations and data. Finally, the continuous measurements obtained with the MMWR allowed us to monitor the vertical situation above the Guadarrama Mountains with temporal resolution of 2 minutes. This instrument has a clear advantage in monitoring short-term episodes of this kind in comparison to radiosondes, which usually produce data at 0000 and 1200 UTC. Acknowledgements This study was supported by the following grants: GRANIMETRO (CGL2010-15930); MICROMETEO (IPT-310000-2010-22). The authors would like to thank the Regional Government of Castile-Len for its financial support through the project LE220A11-2.

Gascn, Estbaliz; Snchez, Jos Luis; Fernndez-Gonzlez, Sergio; Merino, Andrs; Lpez, Laura; Garca-Ortega, Eduardo

2014-05-01

51

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

PubMed

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

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

2015-02-01

52

Increase in Indoleacetic Acid Oxidase Activity of Winter Wheat by Cold Treatment and Gibberellic Acid 1  

PubMed Central

The activity of indoleacetic acid oxidase increased 10-fold during 40 days of cold treatment of winter wheat seedlings. Puromycin and 6-methyl purine inhibited indoleacetic acid oxidase development in the cold. Addition of gibberellic acid stimulated indoleacetic acid oxidase development during germination at room temperature and during cold treatment. Amo-1618 inhibited indoleacetic acid oxidase development before and during cold treatment. Indoleacetic acid treatment increased indoleacetic acid oxidase activity during germination at room temperature while no significant effect on activity was observed during cold treatment. PMID:16657327

Bolduc, Reginald J.; Cherry, Joe H.; Blair, Byron O.

1970-01-01

53

Snowfall induced severe pile-ups in southern Finland on 17 March 2005  

NASA Astrophysics Data System (ADS)

Weather has a great impact on road traffic and several studies have shown that accident risk increases especially during wintry weather conditions. Heavy snowfall, rain or sleet on an icy road surface and formation of hoar frost can make the driving conditions hazardous. Poor visibility, caused by snowfall or dense fog can increase the accident risk significantly and severe pile-ups on highways are possible. The risk for accidents increases, when many drivers can't adjust their speed to the worsening driving conditions even though the hazard is visible. This study presents a severe pile-up case that occurred in southern Finland near Helsinki city on Thursday 17 March 2005. Before this occasion, cold and clear weather prevailed for many days and the driving conditions were mostly fair. On 17 March a low pressure was approaching southern Finland from west. Light snowfall reached the Helsinki metropolitan area early in the morning and it was followed by a band of dense snowfall. During the rush hours, just before 0800 h, pile-ups occurred on four separate highways near Helsinki city almost at the same time (within about ten minutes). In total, almost 300 cars were crashed, 3 persons died and more than 60 persons got injured. The occurrence of dense snowfall during the rush hours had a great impact on driving conditions. The drivers heading towards Helsinki from north or northeast drove at first in clear, dry conditions, with only local light snowfall. But the sudden worsening of weather (and visibility) was a surprise for many although warnings for poor driving conditions were issued the previous evening on radio and TV. In addition to this, automatic vehicle speed measurements showed that the mean speed that morning was only a few km/h lower than on a normal day. When studying the weather situation, it appeared that near the surface there was a thin layer of cold air (2 m temperature being -5-8 degrees) and warmer air above it. In this kind of situation super cooled water can exist in the lower troposphere, and this was also supported by dual-polarization radar observations. This fact might have had a positive impact on the slipperiness of the roads, although freezing drizzle was mainly observed only just after the passage of the dense snowfall and occurrence of the crashes. Due to low surface temperature, preventative anti-icing with salting could not be carried out early that morning (except for the western part of the area). So the snow got packed on the road surface by traffic, causing slippery conditions. In a case like this, real-time warning methods and changing speed limits could be the main way to prevent massive accidents. Dense observation network consisting of road weather observations (including visibility) and radar data should be utilized in the real-time warnings. Dense snowfall is a substantial risk for traffic on highways and severe pile-ups have occurred lately for example in Czech Republic and Austria (during March 2008).

Juga, I.; Hippi, M.

2009-09-01

54

Variable increases in cold hardiness induced in winter rape by plant growth regulators  

Microsoft Academic Search

Triazole and conventional growth regulators were tested for their ability to extend cold hardiness and improve the winter\\u000a survival of winter rape (Brassica napus L.). Winter rape plants were grown in the field (Ottawa 4523? N) and in growth cabinets. Plant growth regulators (PGRs)\\u000a were applied during the early vegetative stage and the plants were allowed to cold harden. Cold-hardened

M. J. Morrison; C. J. Andrews

1992-01-01

55

Effects of small temperature increase and subchronic acid stress on juvenile rainbow trout during winter  

SciTech Connect

Increasing water temperatures, as predicted by global warming are potentially problematic to freshwater fish, whose body temperature is set by their environment. In addition, fish living in softwater lakes face the detrimental effects of acid rain. To determine the cost of living in a warmer climate, two ninety day exposures were conducted during the winter in softwater. In the first exposure, fish were fed to satiation twice daily, while in the second exposure, fish were fed 1% of their wet body weight every four days. Monthly sampling was conducted to determine while body energy reserves: protein, lipids and carbohydrates, and changes in plasma Na and Cl concentrations. Oxygen consumption and nitrogen waste excretion rates were also measured. Fish exposed to acid and fed to satiation showed no ionoregulatory disturbances, an atypical result. Moreover, fish exposed to pH 5.2 had increased appetites, resulting in increased growth. In comparison, fish in the second exposure that were fed a limited ration and exposed to pH 5.2 had a greater mortality rate and lower plasma Na and Cl concentrations, with greater detrimental effects observed in fish exposed to +2 C above ambient. The findings suggest that NaCl present in commercial fish food may compensate for bronchial ion loss during acid exposure, as a result of a stimulation of appetite.

D`Cruz, L.M.; Morgan, I.J.; Wood, C.M. [McMaster Univ., Hamilton, Ontario (Canada)

1995-12-31

56

Effects of Restricted Water Availability and Increased Temperature on the Grain Filling, Drying and Quality of Winter Wheat  

Microsoft Academic Search

Experiments in controlled environments examined the effects of the timing and severity of drought, and increased temperature, on grain development of Hereward winter wheat. Environmental effects on grain specific weight, protein content, Hagberg Falling Number, SDS-sedimentation volume, and sulphur content were also studied. Drought and increased temperature applied before the end of grain filling shortened the grain filling period and

M. J. Gooding; R. H. Ellis; P. R. Shewry; J. D. Schofield

2003-01-01

57

Increased winter soil temperature variability enhances nitrogen cycling and soil biotic activity in temperate heathland and grassland mesocosms  

NASA Astrophysics Data System (ADS)

Winter air temperatures are projected to increase in the temperate zone, whereas snow cover is projected to decrease, leading to increased soil temperature variability, and potentially to changes in nutrient cycling. Here, we experimentally evaluated the effects of increased winter soil temperature variability on selected aspects of the N-cycle in mesocosms containing different plant community compositions. The experiment was replicated at two sites, a colder mountainous upland site with high snow accumulation and a warmer and drier lowland site. Increased soil temperature variability enhanced soil biotic activity for both sites during winter, as indicated by 35% higher nitrogen (N) availability in the soil solution, 40% higher belowground decomposition and a 25% increase in the potential activity of the enzyme cellobiohydrolase. The mobilization of N differed between sites, and the 15N signal in leaves was reduced by 31% in response to winter warming pulses, but only at the cold site, with significant reductions occurring for three of four tested plant species at this site. Furthermore, there was a trend of increased N leaching in response to the recurrent winter warming pulses. Overall, projected winter climate change in the temperate zone, with less snow and more variable soil temperatures, appears important for shifts in ecosystem functioning (i.e. nutrient cycling). While the effects of warming pulses on plant N mobilization did not differ among sites, reduced plant 15N incorporation at the colder temperate site suggests that frost damage may reduce plant N uptake in a warmer world, with important implications for nitrogen cycling and nitrogen losses from ecosystems.

Schuerings, J.; Jentsch, A.; Hammerl, V.; Lenz, K.; Henry, H. A. L.; Malyshev, A. V.; Kreyling, J.

2014-12-01

58

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

PubMed Central

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 1.5C 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. 1.5C 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

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

2014-01-01

59

Climatic warming increases winter wheat yield but reduces grain nitrogen concentration in east China.  

PubMed

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 1.5C 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. 1.5C 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

Tian, Yunlu; Zheng, Chengyan; Chen, Jin; Chen, Changqing; Deng, Aixing; Song, Zhenwei; Zhang, Baoming; Zhang, Weijian

2014-01-01

60

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

USGS Publications Warehouse

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.

Stottlemyer, R.; Toczydlowski, D.

2006-01-01

61

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

USGS Publications Warehouse

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.

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

2012-01-01

62

Twentieth century Antarctic air temperature and snowfall simulations by IPCC climate models  

E-print Network

Twentieth century Antarctic air temperature and snowfall simulations by IPCC climate models Andrew sets of Antarctic near-surface air temperature and snowfall accumulation with 20th century simulations Assessment Report. Annual Antarctic snowfall accumulation trends in the GCMs agree with observations during

Howat, Ian M.

63

Iron-Superoxide Dismutase Expression in Transgenic Alfalfa Increases Winter Survival without a Detectable Increase in Photosynthetic Oxidative Stress Tolerance1  

PubMed Central

To determine whether overexpression of Fe-superoxide (SOD) dismutase would increase superoxide-scavenging capacity and thereby improve the winter survival of transgenic alfalfa (Medicago sativa L.) plants, two genotypes were transformed with the vector pEXSOD10, which contains a cDNA for Arabidopsis Fe-SOD with a chloroplast transit peptide and cauliflower mosaic virus 35S promoter. A novel Fe-SOD was detected by native PAGE in both greenhouse- and field-grown transgenic plants, but activity varied among independent transgenic plants. The increased Fe-SOD activity was associated with increased winter survival over 2 years in field trials, but not with oxidative stress tolerance as measured by resistance of leaves to methyl viologen, a superoxide generator. Total shoot dry matter production over 2 harvest years was not associated with Fe-SOD activity. There was no detectable difference in the pattern of primary freezing injury, as shown by vital staining, nor was there additional accumulation of carbohydrates in field-acclimated roots of the transgenic alfalfa plants. We did not detect any difference in growth of one transgenic plant with high Fe-SOD activity compared with a non-transgenic control. Therefore, the improvement in winter survival did not appear to be a consequence of improved oxidative stress tolerance associated with photosynthesis, nor was it a consequence of a change in primary freezing injury. We suggest that Fe-SOD overexpression reduced secondary injury symptoms and thereby enhanced recovery from stresses experienced during winter. PMID:10759538

McKersie, Bryan D.; Murnaghan, Julia; Jones, Kim S.; Bowley, Stephen R.

2000-01-01

64

Can supplemental food increase winter survival of a threatened cottontail rabbit?  

Microsoft Academic Search

Populations of New England cottontails (Sylvilagus transitionalis) have declined substantially in recent decades in response to habitat loss and fragmentation. Among some remnant populations, cottontails occupy small patches of thicket habitat where they experience high mortality rates as a consequence of limited food during winter. This limitation causes rabbits to forage away from cover where they are exposed to predators.

T. Weidman; J. A. Litvaitis

2011-01-01

65

UTDG -101, a late-maturing orchardgrass germplasm with increased winter hardiness and forage quality  

Technology Transfer Automated Retrieval System (TEKTRAN)

There is a need to identify novel germplasm that is late-maturing, winter hardy, and nutritious that can be incorporated into current orchardgrass breeding programs. The United States Department of Agriculture - Agricultural Research Service announces the public release of a late-maturing orchardgr...

66

Impacts of Severe Winter Weather during December 1989 in the Lake Erie Snowbelt.  

NASA Astrophysics Data System (ADS)

December 1989 was the coldest December in over 100 years in the Lake Erie snowbelt of Ohio, Pennsylvania, and New York. Mean temperatures of 9C were 7C lower than average and extreme minima reached 30C. Snow fell on 20 to 25 days of the month and snowfall totals of 100 to 200 cm were twice the December average. Some locations reported record snowfalls and the greatest snow depths of this century. Several segments of society were studied to assess the impacts of this severe winter weather.The severe weather had minimal impacts on school districts. Over half (54%) of the districts had no closures due to snow but costs for snow removal increased for schools. Ski centers reported a 50% to 100% increase in revenues over December 1988 and the best December skiing in many years. Lake ports had higher operating costs and loss of shipments. Costs for snow and ice control on Interstate 90 (I-90) in the snowbelt increased at least $1326 km1 over December 1988, but traffic flow was maintained. Person-hours spent on snow and ice control on I-90 increased 59%. An average of 111 000 kg km1 (200 tons mile1) of salt and grit was spread on I-90, an increase of 50 000 kg km1 (89 tons mile1) over December 1988. Colleges, airports, agriculture, hospitals, urban mass transit, electric utilities, and government agencies had only minor disruptions due to the severe winter weather.

Schmidlin, Thomas W.

1993-04-01

67

The Potential of Five Winter-grown Crops to Reduce Root-knot Nematode Damage and Increase Yield of Tomato  

PubMed Central

Broccoli (Brassica oleracea), carrot (Daucus carota), marigold (Tagetes patula), nematode-resistant tomato (Solanum lycopersicum), and strawberry (Fragaria ananassa) were grown for three years during the winter in a root-knot nematode (Meloidogyne incognita) infested field in Southern California. Each year in the spring, the tops of all crops were shredded and incorporated in the soil. Amendment with poultry litter was included as a sub-treatment. The soil was then covered with clear plastic for six weeks and M. incognita-susceptible tomato was grown during the summer season. Plastic tarping raised the average soil temperature at 13 cm depth by 7C.The different winter-grown crops or the poultry litter did not affect M. incognita soil population levels. However, root galling on summer tomato was reduced by 36%, and tomato yields increased by 19% after incorporating broccoli compared to the fallow control. This crop also produced the highest amount of biomass of the five winter-grown crops. Over the three-year trial period, poultry litter increased tomato yields, but did not affect root galling caused by M. incognita. We conclude that cultivation followed by soil incorporation of broccoli reduced M. incognita damage to tomato. This effect is possibly due to delaying or preventing a portion of the nematodes to reach the host roots. We also observed that M. incognita populations did not increase under a host crop during the cool season when soil temperatures remained low (< 18C). PMID:22736848

Lpez-Prez, Jose Antonio; Roubtsova, Tatiana; de Cara Garca, Miguel

2010-01-01

68

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

E-print Network

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

Park, Rokjin

69

Quantifying snowfall and avalanche release synchronization: A case study  

NASA Astrophysics Data System (ADS)

We quantify the synchronization between snowfall and natural avalanches in relation to terrain properties at the detachment zone. We analyze field statistics of 549 avalanche events in terms of slope, aspect, timing, coordinate, and release area, identified by a georeferencing procedure applied on terrestrial photography. The information from the digital pictures, together with associated meteorological data, provides us with the input needed for model calibration, namely, the magnitude of snowfall, the snow compaction rate, and the timing of precipitation and of avalanche events. Synchronization between snowfall and avalanches is established for different slope categories. We obtain an average probability of release after a snow event of 30% and 16% for the high- and low-slope categories (average slope 44 and 36, respectively). Using the notion of information entropy, we quantify the uncertainty in predicting avalanche occurrence from a snow event. The steeper slopes correspond to a larger entropy in avalanche prediction. Further, the presented method allows us to establish the return period of avalanches without requiring a long series of data. When considering events regardless of their release depth, the avalanches had a return period of 48 days (higher slopes) and 88 days (lower slopes). Finally, we determine the average daily detachment rate as a function of snow depth and the return period of avalanches as a function of the release depth.

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

2015-02-01

70

Social perceptions versus meteorological observations of snow and winter along the Front Range  

NASA Astrophysics Data System (ADS)

This research aims to increase understanding of Front Range residents' perceptions of snow, winter and hydrologic events. This study also investigates how an individual's characteristics may shape perceptions of winter weather and climate. A survey was administered to determine if perceptions of previous winters align with observed meteorological data. The survey also investigated how individual characteristics influence perceptions of snow and winter weather. The survey was conducted primarily along the Front Range area of the state of Colorado in the United States of America. This is a highly populated semi-arid region that acts as an interface between the agricultural plains to the east that extend to the Mississippi River and the Rocky Mountains to the west. The climate is continental, and while many people recreate in the snowy areas of the mountains, most live where annual snowfall amounts are low. Precipitation, temperature, and wind speed datasets from selected weather stations were analyzed to determine correct survey responses. Survey analysis revealed that perceptions of previous winters do not necessarily align with observed meteorological data. The mean percentage of correct responses to all survey questions was 36.8%. Further analysis revealed that some individual characteristics (e.g. winter recreation, source of winter weather information) did influence correct responses to survey questions.

Milligan, William James, IV

71

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

SciTech Connect

Emission inventories indicate that the largest increases in SO{sub 2} emissions have occurred in Asia during the last 20 years. By inference, largest increases in aerosol, produced primarily by the conversion of SO{sub 2} 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) vertical aerosol optical depths (converted to 550 nm) from 1979 to 2000 on a 1{sup o} by 1{sup o} global grid. The anthropogenic component of the TOMS aerosol record is maximized by examining the seasonal cycles of desert dust and Boreal fire smoke, and identifying the months of the year for which the desert dust and Boreal fire smoke are least conspicuous. Gobi and Taklimakan desert dust in Asia is prevalent in the TOMS record during spring, and eastern Siberian smoke from Boreal forest fires is prevalent during summer. Aerosol trends are calculated on a regional basis during winter (November-February) to maximize the anthropogenic component of the aerosol record. Large increases in aerosol optical depths between 1979 and 2000 are present over the China coastal plain and the Ganges river basin in India. Aerosol increased by 17% per decade during winter over the China coastal plain, while SO{sub 2} emissions over the same geographical region increased by 33% per decade.

Massie, Steven T.; Torres, O.; Smith, Steven J.

2004-12-01

72

Hemispheric and Interannual Comparisons of Polar Winter CO2 Clouds on Mars  

NASA Astrophysics Data System (ADS)

Polar carbon dioxide snow clouds contribute substantial material to the seasonal caps of Mars, in addition to direct surface frost formation. Snow clouds also affect the polar heat budget through two primary mechanisms: 1) snow particles decrease polar infrared emissivity during winter, and 2) fine-grained snow deposits increase solar albedo during summer. These effects can strongly alter the seasonal cap mass budget, and possibly explain the existence of the perennial CO2 deposits near the Martian south pole. Mapping the distribution and quantifying the abundance of CO2 snowfall therefore has important implications for the study of Mars' present-day climate. The phenomenon of condensing martian air is of course also interesting in its own right, from an atmospheric science perspective. We used data primarily from the Mars Climate Sounder (MCS) onboard the Mars Reconnaissance Orbiter to investigate the occurrence and properties (optical depth, particle size, altitude) of CO2 clouds in the winter polar regions. MCS retrieved temperature and aerosol opacity profiles now span four Mars years (MY28-MY31), allowing direct inter-annual comparisons for selected locations and seasons. Examples of observed inter-annual variability include decreased snowfall likely due to disruption of the northern polar vortex during the global dust storm of MY28. We also observe very distinct patterns of condensation in the northern and southern hemispheres, with cloud activity being much more intense in the northern hemisphere, but confined to higher latitudes, than in the south. Northern polar winter cloud activity is also distinctly bimodal in time, whereas southern winter cloud activity is evenly distributed over the winter season. In this presentation, we will present a summary of these observations and explore possible explanations for the variability in polar cloud phenomena.

Hayne, P. O.; Kleinboehl, A.; Heavens, N. G.; Paige, D. A.; Schofield, J. T.; Kass, D. M.; Shirley, J. H.; McCleese, D. J.

2013-12-01

73

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

PubMed

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 37-50C 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 (55-60C) 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

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

2014-11-01

74

Long term CO2 enrichment in a temperate grassland increases soil respiration during late autumn and winter  

NASA Astrophysics Data System (ADS)

Soil respiration of terrestrial ecosystems, a major component in the global carbon cycle may comprise a potential positive feedback to elevated atmospheric CO2 concentrations. However, analyses reflecting seasonal variability of soil CO2 fluxes under long term CO2 enrichment including winter soil respiration are rare. At the Giessen free-air CO2 enrichment in a temperate grassland (Gi-FACE), adding +20% to the ambient CO2 concentration since 1998, we analyzed the seasonal dynamics of soil respiration including dormant seasons. We defined five seasons, with respect to management practices and phenological cycles. For a period of three years (2008-2010), we performed weekly measurements of soil respiration with an LI-8100 soil CO2 efflux survey chamber from four vegetation-free subplots per FACE or control plot and tested for a CO2 effect within the defined seasons. The results revealed a pronounced and repeated increase of soil respiration during winter dormancy. However, during spring and summer season, characterized by strong above- and below-ground plant growth, no significant change in soil respiration was observed at the Gi-FACE under elevated CO2. This suggests (i) that measuring soil respiration only during the vegetative growth period in CO2 enrichment experiments may underestimate the true soil-respiratory CO2 loss (i.e. overestimate the C sequestered), (ii) that additional C assimilated by plants during the growing period, getting transferred below-ground until autumn, will quickly be lost again via enhanced heterotrophic respiration during the off-season, driving the increased winter soil respiration under elevated CO2.

Keidel, Lisa; Moser, Gerald; Kammann, Claudia; Grnhage, Ludger; Mller, Christoph

2014-05-01

75

Long-term continuous monitoring of mercury in the Russian arctic: winter increase of atmospheric mercury depletion events  

NASA Astrophysics Data System (ADS)

Among pollutants mercury is a major environmental concern due to its ecological hazard. The mercury can reside in the atmosphere for a long time high, and it is a reason of its global propagation in the Northern Hemisphere and elevated mercury concentrations are reported in the Arctic environment. First time, in 1995, the effect of atmospheric mercury depletion in the troposphere was found at the Canadian station Alert. This phenomenon (called the Atmospheric Mercury Depletion Event - AMDE) is observed during April-June, when the Polar sunrise starts till the end of the snowmelt. The same effect was reported for other polar stations situated to the north of 60 N. Long-term continuous monitoring of gaseous elemental mercury in the surface air at the polar station Amderma (69,720N; 61,620E) using the analyzer Tekran 2537A has been conducted from Jun 2001 to date. Individual measurements were collected every thirty minutes. It has been shown, that during eleven years of observations the AMDEs were observed every year, from the end of March till early June. For the winter period (Dec-Feb) these events of the atmospheric mercury depletion were registered from 2010 to 2013, which had not been observed before. A large number of hours during the day, when the concentration of mercury was recorded at level of below 1 ng/m3, was registered during Dec-Feb. The sun declination above the horizon is negative, and solar activity is still not enough to trigger the photochemical reactions. The these last 3 years confirmed a tendency to displacement of AMDEs to the winter season, which leads to an additional factor entry of mercury in various biological objects, due to the additional deposition of various forms of mercury on the snowpack. At the same time, especially during the winter seasons, there is a substantial increase (up to 8 times) of AMDEs, compared with the previous years. In particular, in winter 2013 the maximum number of AMDs reached 31 cases. The explanation can be the following: the withdrawal of elemental mercury from the atmosphere may be caused by deposition of mercury on marine aerosol particles. Marine aerosol concentration increases in the case of exemption from coastal ice (Kara Sea) and, simultaneously, at the time when the northern wind direction is dominating. When the southern wind direction is prevailing, the deposition of mercury on anthropogenic aerosols transported from the middle latitudes is taken place. Acknowledgement - Financial support for the monitoring program was provided by Environment Canada, AMAP Secretariate and Russian Federal Service for Hydrometeorology and Environmental Monitoring.

Pankratov, Fidel; Mahura, Alexander; Popov, Valentin; Katz, Oleg

2014-05-01

76

Effects of Snowfalls on Motor Vehicle Collisions, Injuries, and Fatalities  

PubMed Central

Objectives. We estimated the effects of snowfalls on US traffic crash rates between 1975 and 2000. Methods. We linked all recorded fatal crashes (1.4 million) for the 48 contiguous states from 1975 through 2000 to daily state weather data. For a subsample including 17 states during the 1990s, we also linked all recorded property-damage-only crashes (22.9 million) and nonfatal-injury crashes (13.5 million) to daily weather data. Employing negative binomial regressions, we investigated the effects of snowfall on crash counts. Fixed effects and other controls were included to address potential confounders. Results. Snow days had fewer fatal crashes than dry days (incidence rate ratio [IRR] = 0.93; 95% confidence interval [CI] = 0.90, 0.97), but more nonfatal-injury crashes (IRR = 1.23; 95% CI = 1.18, 1.29) and property-damage-only crashes (IRR=1.45; 95% CI=1.38, 1.52). The first snowy day of the year was substantially more dangerous than other snow days in terms of fatalities (IRR = 1.14; 95% CI=1.08, 1.21), particularly for elderly drivers (IRR=1.34; 95% CI=1.23, 1.50). Conclusions. The toll of snow-related crashes is substantial. Our results may help estimate the potential benefits of safety innovations currently proposed by meteorology and traffic safety experts. PMID:15623871

Eisenberg, Daniel; Warner, Kenneth E.

2005-01-01

77

Sensitivity of an energy balance climate model with predicted snowfall rates  

NASA Technical Reports Server (NTRS)

A snowfall parameterization and a polar-ice-sheet model are developed and applied to the two-level zonally averaged seasonal energy-balance climate model of Held and Suarez (1979), and sensitivity experiments involving changes in insolation are performed both with and without ice sheets. The results are presented in tables and graphs, and the hydrological-cycle response to insolation changes is found to be similar to that predicted by global-circulation models employing prescribed precipitation levels, with a somewhat higher sensitivity in the snow line. The area covered by ice sheets in the ice-sheet models is shown to be greater than that covered by permanent snow in the models without ice sheets, an effect attributed to lower surface temperatures over the ice. It is inferred that an increase in the solar constant can cause increased high-latitude precipitation but not an ice age.

Bowman, K. P.

1985-01-01

78

[Effects of asymmetric warming on the growth characteristics and yield components of winter wheat under free air temperature increased].  

PubMed

In 2007-2009, a field warming experiment was performed in Nanjing of Jiangsu Province, China to investigate the effects of asymmetric warming (all-day warming, AW; daytime warming from 6:00 to 18:00, DW; and nighttime warming from 18:00 to 6:00, NW) on the growth and development of winter wheat under free air temperature increase (FATI). Asymmetric warming increased the effective tillers and decreased the ineffective tillers. In CK plot, the ineffective tillers were 2.6, 1.7 and 3.5 times of those in AW, DW and NW plots, while the effective tillers were decreased by 13.7%, 3.2%, and 0.5%, respectively. Asymmetric warming also increased the plant height, flag leaf area, and the total green leaf area and green leaf ratio at flowing stage. In treatments AW, DW, and NW, the plant height was increased by 5.6%, 4.5%, and 1.3%, flag leaf area increased by 45.7%, 39.4% and 26.1%, total green leaf area increased by 25.1%, 29.8%, and 17.3%, and green leaf ratio increased by 37.7%, 43.3%, and 38.7%, respectively, compared with CK. As for the yield components, the spikelet number per panicle and the filled grain number per panicle in treatments AW, DW and NW were increased by 4.1%, 5.7%, and 1.7%, and by 2.2%, 5.3%, and 2.6%, respectively. Though the grain/leaf ratio in treatments AW, DW, and NW was decreased by 15.3%, 8.5%, and 11.3%, the thousand-grain mass in the treatments was increased by 6.9%, 6.2% and 11.8%, and thus, the yield per unit was increased by 27.0%, 40.1%, and 18.3%, respectively, compared to the CK. Our results suggested that under anticipated warming, the winter wheat productivity in eastern China would be further enhanced. PMID:21657024

Tian, Yun-lu; Chen, Jin; Deng, Ai-xing; Zheng, Jian-chu; Zhang, Wei-jian

2011-03-01

79

Development of the Pan-Arctic Snowfall Reconstruction: New Land-Based Solid Precipitation Estimates for 194099  

E-print Network

Development of the Pan-Arctic Snowfall Reconstruction: New Land-Based Solid Precipitation Estimates) ABSTRACT A new product, the Pan-Arctic Snowfall Reconstruction (PASR), is developed to address the problem employed for estimating pan-arctic snowfall. The NASA Interannual-to-Seasonal Prediction Project Catch

Dery, Stephen

80

INCIDENCE OF PLAGUE ASSOCIATED WITH INCREASED WINTER-SPRING PRECIPITATION IN NEW MEXICO  

Microsoft Academic Search

Plague occurs episodically in many parts of the world, and some outbreaks appear to be related to increased abundance of rodents and other mammals that serve as hosts for vector fleas. Climate dynamics may influence the abundance of both fleas and mammals, thereby having an indirect effect on human plague incidence. An understanding of the relationship between climate and plague

ROBERT R. PARMENTER; EKTA PRATAP YADAV; CHERYL A. PARMENTER; PAUL ETTESTAD; KENNETH L. GAGE

81

Exploring Alternate Parameterizations for Snowfall with Validation from Satellite and Terrestrial Radars  

NASA Technical Reports Server (NTRS)

Increases in computational resources have allowed operational forecast centers to pursue experimental, high resolution simulations that resolve the microphysical characteristics of clouds and precipitation. These experiments are motivated by a desire to improve the representation of weather and climate, but will also benefit current and future satellite campaigns, which often use forecast model output to guide the retrieval process. Aircraft, surface and radar data from the Canadian CloudSat/CALIPSO Validation Project are used to check the validity of size distribution and density characteristics for snowfall simulated by the NASA Goddard six-class, single-moment bulk water microphysics scheme, currently available within the Weather Research and Forecast (WRF) Model. Widespread snowfall developed across the region on January 22, 2007, forced by the passing of a midlatitude cyclone, and was observed by the dual-polarimetric, C-band radar King City, Ontario, as well as the NASA 94 GHz CloudSat Cloud Profiling Radar. Combined, these data sets provide key metrics for validating model output: estimates of size distribution parameters fit to the inverse-exponential equations prescribed within the model, bulk density and crystal habit characteristics sampled by the aircraft, and representation of size characteristics as inferred by the radar reflectivity at C- and W-band. Specified constants for distribution intercept and density differ significantly from observations throughout much of the cloud depth. Alternate parameterizations are explored, using column-integrated values of vapor excess to avoid problems encountered with temperature-based parameterizations in an environment where inversions and isothermal layers are present. Simulation of CloudSat reflectivity is performed by adopting the discrete-dipole parameterizations and databases provided in literature, and demonstrate an improved capability in simulating radar reflectivity at W-band versus Mie scattering assumptions.

Molthan, Andrew L.; Petersen, Walter A.; Case, Jonathan L.; Dembek, Scott R.; Jedlovec, Gary J.

2009-01-01

82

Exploring Alternative Parameterizations for Snowfall with Validation from Satellite and Terrestrial Radars  

NASA Technical Reports Server (NTRS)

Increases in computational resources have allowed operational forecast centers to pursue experimental, high resolution simulations that resolve the microphysical characteristics of clouds and precipitation. These experiments are motivated by a desire to improve the representation of weather and climate, but will also benefit current and future satellite campaigns, which often use forecast model output to guide the retrieval process. The combination of reliable cloud microphysics and radar reflectivity may constrain radiative transfer models used in satellite simulators during future missions, including EarthCARE and the NASA Global Precipitation Measurement. Aircraft, surface and radar data from the Canadian CloudSat/CALIPSO Validation Project are used to check the validity of size distribution and density characteristics for snowfall simulated by the NASA Goddard six-class, single moment bulk water microphysics scheme, currently available within the Weather Research and Forecast (WRF) Model. Widespread snowfall developed across the region on January 22, 2007, forced by the passing of a mid latitude cyclone, and was observed by the dual-polarimetric, C-band radar King City, Ontario, as well as the NASA 94 GHz CloudSat Cloud Profiling Radar. Combined, these data sets provide key metrics for validating model output: estimates of size distribution parameters fit to the inverse-exponential equations prescribed within the model, bulk density and crystal habit characteristics sampled by the aircraft, and representation of size characteristics as inferred by the radar reflectivity at C- and W-band. Specified constants for distribution intercept and density differ significantly from observations throughout much of the cloud depth. Alternate parameterizations are explored, using column-integrated values of vapor excess to avoid problems encountered with temperature-based parameterizations in an environment where inversions and isothermal layers are present. Simulation of CloudSat reflectivity is performed by adopting the discrete-dipole parameterizations and databases provided in literature, and demonstrate an improved capability in simulating radar reflectivity at W-band versus Mie scattering assumptions.

Molthan, Andrew L.; Petersen, Walter A.; Case, Jonathan L.; Dembek, Scott R.

2009-01-01

83

Exploring Alternative Parameterizations for Snowfall with Validation from Satellite and Terrestrial Radars  

NASA Astrophysics Data System (ADS)

Increases in computational resources have allowed operational forecast centers to pursue experimental, high resolution simulations that resolve the microphysical characteristics of clouds and precipitation. These experiments are motivated by a desire to improve the representation of weather and climate, but will also benefit current and future satellite campaigns, which often use forecast model output to guide the retrieval process. The combination of reliable cloud microphysics and radar reflectivity may constrain radiative transfer models used in satellite simulators during future missions, including EarthCARE and the NASA Global Precipitation Measurement. Aircraft, surface and radar data from the Canadian CloudSat/CALIPSO Validation Project are used to check the validity of size distribution and density characteristics for snowfall simulated by the NASA Goddard six-class, single-moment bulk water microphysics scheme, currently available within the Weather Research and Forecast (WRF) Model. Widespread snowfall developed across the region on January 22, 2007, forced by the passing of a midlatitude cyclone, and was observed by the dual-polarimetric, C-band radar King City, Ontario, as well as the NASA 94 GHz CloudSat Cloud Profiling Radar. Combined, these data sets provide key metrics for validating model output: estimates of size distribution parameters fit to the inverse-exponential equations prescribed within the model, bulk density and crystal habit characteristics sampled by the aircraft, and representation of size characteristics as inferred by the radar reflectivity at C- and W-band. Specified constants for distribution intercept and density differ significantly from observations throughout much of the cloud depth. Alternate parameterizations are explored, using column-integrated values of vapor excess to avoid problems encountered with temperature-based parameterizations in an environment where inversions and isothermal layers are present. Simulation of CloudSat reflectivity is performed by adopting the discrete-dipole parameterizations and databases provided in literature, and demonstrate an improved capability in simulating radar reflectivity at W-band versus Mie scattering assumptions.

Molthan, A.; Petersen, W. A.; Case, J.; Dembek, S.

2009-12-01

84

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.

85

Increase in body size is correlated to warmer winters in a passerine bird as inferred from time series data  

PubMed Central

Climate change is expected to affect natural populations in many ways. One way of getting an understanding of the effects of a changing climate is to analyze time series of natural populations. Therefore, we analyzed time series of 25 and 20years, respectively, in two populations of the citril finch (Carduelis citrinella) to understand the background of a dramatic increase in wing length in this species over this period, ranging between 1.3 and 2.9 phenotypic standard deviations. We found that the increase in wing length is closely correlated to warmer winters and in one case to rain in relation to temperature in the summer. In order to understand the process of change, we implemented seven simulation models, ranging from two nonadaptive models (drift and sampling), and five adaptive models with selection and/or phenotypic plasticity involved and tested these models against the time series of males and females from the two population separately. The nonadaptive models were rejected in each case, but the results were mixed when it comes to the adaptive models. The difference in fit of the models was sometimes not significant indicating that the models were not different enough. In conclusion, the dramatic change in mean wing length can best be explained as an adaptive response to a changing climate. PMID:25628864

Bjrklund, Mats; Borras, Antoni; Cabrera, Josep; Senar, Juan Carlos

2015-01-01

86

Increase in body size is correlated to warmer winters in a passerine bird as inferred from time series data.  

PubMed

Climate change is expected to affect natural populations in many ways. One way of getting an understanding of the effects of a changing climate is to analyze time series of natural populations. Therefore, we analyzed time series of 25 and 20years, respectively, in two populations of the citril finch (Carduelis citrinella) to understand the background of a dramatic increase in wing length in this species over this period, ranging between 1.3 and 2.9 phenotypic standard deviations. We found that the increase in wing length is closely correlated to warmer winters and in one case to rain in relation to temperature in the summer. In order to understand the process of change, we implemented seven simulation models, ranging from two nonadaptive models (drift and sampling), and five adaptive models with selection and/or phenotypic plasticity involved and tested these models against the time series of males and females from the two population separately. The nonadaptive models were rejected in each case, but the results were mixed when it comes to the adaptive models. The difference in fit of the models was sometimes not significant indicating that the models were not different enough. In conclusion, the dramatic change in mean wing length can best be explained as an adaptive response to a changing climate. PMID:25628864

Bjrklund, Mats; Borras, Antoni; Cabrera, Josep; Senar, Juan Carlos

2015-01-01

87

Modeling changes in extreme snowfall events in the Central Rocky Mountains Region with the Fully-Coupled WRF-Hydro Modeling System  

NASA Astrophysics Data System (ADS)

Modeling of extreme weather events often require very finely resolved treatment of atmospheric circulation structures in order to produce and localize large magnitudes of moisture fluxes that result in extreme precipitation. This is particularly true for cool season orographic precipitation processes where the representation of landform can significantly influence vertical velocity profiles and cloud moisture entrainment rates. In this work we report on recent progress in high resolution regional climate modeling of the Colorado Headwaters region using an updated version of the Weather Research and Forecasting (WRF) model and a hydrological extension package called WRF-Hydro. Previous work has shown that the WRF-Hydro modeling system forced by high resolution WRF model output can produce credible depictions of winter orographic precipitation and resultant monthly and annual river flows. Here we present results from a detailed study of an extreme springtime snowfall event that occurred along the Colorado Front Range in March of 2003. First an analysis of the simulated streamflows resulting from the melt out of that event are presented followed by an analysis of projected streamflows from the event where the atmospheric forcing in the WRF model is perturbed using the Psuedo-Global-Warming (PGW) perturbation methodology. Results from the impact of warming on total precipitation, snow-rain partitioning and surface hydrological fluxes (evapotranspiration and runoff) will be discussed in the context of how potential changes in temperature impact the amount of precipitation, the phase of precipitation (rain vs. snow) and the timing and amplitude of streamflow responses. It is shown that under the assumptions of the PGW method, intense precipitation rates increase during the event and, more importantly, that more precipitation falls as rain versus snow which significantly amplifies the runoff response from one where runoff is produced gradually to where runoff is more rapidly translated into streamflow values that approach significant flooding risks.

gochis, David; rasmussen, Roy; Yu, Wei; Ikeda, Kyoko

2014-05-01

88

Snowfall in the Northwest Iberian Peninsula: Synoptic Circulation Patterns and Their Influence on Snow Day Trends  

PubMed Central

In recent decades, a decrease in snowfall attributed to the effects of global warming (among other causes) has become evident. However, it is reasonable to investigate meteorological causes for such decrease, by analyzing changes in synoptic scale patterns. On the Iberian Peninsula, the Castilla y Len region in the northwest consists of a central plateau surrounded by mountain ranges. This creates snowfalls that are considered both an important water resource and a transportation risk. In this work, we develop a classification of synoptic situations that produced important snowfalls at observation stations in the major cities of Castilla y Len from 1960 to 2011. We used principal component analysis (PCA) and cluster techniques to define four synoptic patterns conducive to snowfall in the region. Once we confirmed homogeneity of the series and serial correlation of the snowfallday records at the stations from 1960 to 2011, we carried out a Mann-Kendall test. The results show a negative trend at most stations, so there are a decreased number of snowfall days. Finally, variations in these meteorological variables were related to changes in the frequencies of snow events belonging to each synoptic pattern favorable for snowfall production at the observatory locations. PMID:25152912

Merino, Andrs; Fernndez, Sergio; Hermida, Luca; Lpez, Laura; Snchez, Jos Luis; Garca-Ortega, Eduardo; Gascn, Estbaliz

2014-01-01

89

Lawn Winterization  

NSDL National Science Digital Library

Contrary to what many people think, Fall is the time of year when your turf needs attention. The following three steps need to be completed before the first snowfall: Apply Fertilizer Lower Mower Height Drain Secondary Water System Fall fertilization is best because the lawn has passed through the stressful summer months and needs to rebuild itself. Fall Lawn Care Guide ...

Miss Melrose

2006-10-13

90

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

NASA Astrophysics Data System (ADS)

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 1837 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.

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

2012-12-01

91

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

Microsoft Academic Search

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

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

2009-01-01

92

Winter Storm  

NSDL National Science Digital Library

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 ...

Sarah

2009-09-28

93

Clover cover crops under-sown in winter wheat increase yield of subsequent spring barleyEffect of N dose and companion grass  

Microsoft Academic Search

Four two-year field trials, arranged in randomised split-plots, were carried out in southern Sweden with the aim of determining whether reduced N fertiliser dose in winter wheat production with spring under-sown clover cover crops, with or without perennial ryegrass in the seed mixture, would increase the clover biomass and hence the benefits of the cover crops in terms of the

Gran Bergkvist; Maria Stenberg; Johanna Wetterlind; Birgitta Bth; Sara Elfstrand

2011-01-01

94

Total Lightning Observations within Electrified Snowfall using Polarimetric Radar, LMA, and NLDN Measurements  

NASA Technical Reports Server (NTRS)

Four electrified snowfall cases are examined using total lightning measurements from lightning mapping arrays (LMAs), and the National Lightning Detection Network (NLDN) from Huntsville, AL and Washington D.C. In each of these events, electrical activity was in conjunction with heavy snowfall rates, sometimes exceeding 5-8 cm hr-1. A combination of LMA, and NLDN data also indicate that many of these flashes initiated from tall communications towers and traveled over large horizontal distances. During events near Huntsville, AL, the Advanced Radar for Meteorological and Operational Research (ARMOR) C-band polarimetric radar was collecting range height indicators (RHIs) through regions of heavy snowfall. The combination of ARMOR polarimetric radar and VHF LMA observations suggested contiguous layer changes in height between sloping aggregate-dominated layers and horizontally-oriented crystals. These layers may have provided ideal conditions for the development of extensive regions of charge and resultant horizontal propagation of the lightning flashes over large distances.

Schultz, Christopher J.; Carey, Lawerence D.; Brunning, Eric C.; Blakeslee, Richard

2013-01-01

95

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.

96

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

NASA Astrophysics Data System (ADS)

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.

Loik, M. E.

2012-12-01

97

Lidar-Radar Measurements of Snowfall Edwin W. Eloranta--Univ. Of Wisconsin  

E-print Network

Lidar-Radar Measurements of Snowfall Edwin W. Eloranta--Univ. Of Wisconsin Aerodynamic flow around a lidar-radar based technique to measure the downward flux of snow at an altitude of ~100m. When particles the square of the mass of the average snowflake. For particles large compared to the wavelength, the lidar

Eloranta, Edwin W.

98

Effect of storm trajectories on snowfall chemistry in Rocky Mountain National Park, Colorado  

USGS Publications Warehouse

Snowfall samples from snowstorms lasting 1 to 4 days were collected near the Bear Lake snow telemetry (SnoTel) site in Rocky Mountain National Park, Colorado (ROMO), during the 1998-99 snowfall season to determine if storms moving in from different directions affect the chemistry of precipitation in the park. Storm pathways to Bear Lake during snowfall events were estimated using the HYSPLIT4 backward-trajectory model developed by the National Oceanic and Atmospheric Administration. Deposition of acidic ions of nitrate and sulfate in snowfall during the study varied substantially (two- to threefold) depending on storm trajectory because air masses traversing the park originated from different surrounding areas, including some having large sources of emissions of nitrate and sulfate. Concentrations of nitrate and sulfate in samples were lowest when storms reached ROMO from north and east of the park and were elevated when air masses traveled from the west where a number of power plants are located. Concentrations were highest in storms reaching ROMO from the south, a region with urban areas including Metropolitan Denver.

Ingersoll, G.P.; Tonnessen, K.A.; Campbell, D.H.; Glass, B.R.; Torizzo, A.O.

2001-01-01

99

Remote sensing analysis of a Mediterranean thundersnow and low-altitude heavy snowfall event  

NASA Astrophysics Data System (ADS)

On the 8 of March 2010 a heavy snowfall accompanied by lightning occurred over Catalonia (NE Spain), in the Western Mediterranean. Total lightning observations included 101 cloud-to-ground flashes and 169 intra-cloud flashes. Precipitation amounts in 24 h exceeded 100 mm and snow depths over low altitude terrain, where snow is rare, surpassed 30 cm. Snow accumulations collapsed the regional communication transport network and the border with France was closed several hours. Occurrence of wet snow combined with increasingly strong winds caused widespread damage over large forest areas estimated in more than 20 MEur and affected dramatically the high voltage power line distribution grid due to ice accretion, particularly in NE Catalonia where 33 high power electrical towers were knocked down. The meteorological framework at synoptic scale was dominated at low levels by a northern flow over Iberia due to a blocking high pressure system on the British Isles, and an upper level cold trough, which favoured a rapid cyclogenesis over the Mediterranean (9.2 hPa drop in 12 h). Weather radar observations indicated predominance of stratiform precipitation and some low-topped convection, with maximum reflectivities and tops mostly below 40 dBZ and 4 km respectively. The presence of mesoscale gravity waves, caused by wind-shear instability, is suggested as a triggering element for convection and subsequent lightning. Comparison of accumulated precipitation and lightning maps indicated clusters of lightning data unrelated to precipitation maxima. Further investigation of total lightning characteristics and co-located radar observations suggested a triggering effect by tall telecommunication towers inducing cloud-to-ground flashes and subsequent intra-cloud lightning.

Bech, Joan; Pineda, Nicolau; Rigo, Tomeu; Aran, Montserrat

2013-04-01

100

Scattering by Nonspherical Ice Particles at High Microwave Frequencies and Its Application to Snowfall Retrievals (Invited)  

NASA Astrophysics Data System (ADS)

Despite their great significance in modulating the Earth radiation budget and the global hydrological cycle, cloud ice water and snow precipitation remain to be the most inadequately measured geophysical variables. One promising approach is to estimate the ice water amount and/or snowfall rate by measuring the scattering signatures at microwave frequencies by either active (radars) or passive radiometers) remote sensing. Satellite data from CloudSat radar and future GPM radiometers provide excellent opportunities to retrieve cloud ice water and snowfall globally. To develop an algorithm that converts the observed radar reflectivity or brightness temperature to ice water amount or snowfall rate, one must know the single-scattering properties, i.e., scattering cross sections, phase functions, etc., of the ice/snow particles. The nonspherical nature of ice particles adds one more layer of complexity to the cloud/precipitation retrieval problem that has already been complicated by the uncertainties of particle size distributions, surface contaminations, beam-filling problems, etc. The ultimate goal of this study is to find the most appropriate way in representing ice particle scattering in radar reflectivity and radiative transfer calculations. In this talk, we first review previous studies related to the scattering of nonspherical ice particles at the microwave spectrum, and demonstrate some of the advantages and pitfalls in approximating ice particles as spheres with an assigned density in radiative transfer and radar reflectivity calculations. Then, our current effort to build an comprehensive single-scattering database of realistic ice/snow particles by using Discrete Dipole Approximation calculations will be introduced. In particular, our effort in designing realistic snowflakes with many constituent ice crystals based on observed structural properties of snowflakes will be introduced. The single-scattering properties of these snowflakes and the possible implications to snowfall remote sensing will be discussed. Finally, we will present the research results on applying the above database to retrieve global snowfall climatology from CloudSat data and to build a snowfall-brightness temperature library.

Liu, G.

2010-12-01

101

Future increases in Arctic precipitation linked to local evaporation and sea-ice retreat.  

PubMed

Precipitation changes projected for the end of the twenty-first century show an increase of more than 50 per cent in the Arctic regions. This marked increase, which is among the highest globally, has previously been attributed primarily to enhanced poleward moisture transport from lower latitudes. Here we use state-of-the-art global climate models to show that the projected increases in Arctic precipitation over the twenty-first century, which peak in late autumn and winter, are instead due mainly to strongly intensified local surface evaporation (maximum in winter), and only to a lesser degree due to enhanced moisture inflow from lower latitudes (maximum in late summer and autumn). Moreover, we show that the enhanced surface evaporation results mainly from retreating winter sea ice, signalling an amplified Arctic hydrological cycle. This demonstrates that increases in Arctic precipitation are firmly linked to Arctic warming and sea-ice decline. As a result, the Arctic mean precipitation sensitivity (4.5 per cent increase per degree of temperature warming) is much larger than the global value (1.6 to 1.9 per cent per kelvin). The associated seasonally varying increase in Arctic precipitation is likely to increase river discharge and snowfall over ice sheets (thereby affecting global sea level), and could even affect global climate through freshening of the Arctic Ocean and subsequent modulations of the Atlantic meridional overturning circulation. PMID:24805239

Bintanja, R; Selten, F M

2014-05-22

102

Winters fuels report  

SciTech Connect

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

NONE

1995-10-27

103

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

Microsoft Academic Search

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)

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

2004-01-01

104

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

NASA Astrophysics Data System (ADS)

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.

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

2013-09-01

105

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

NASA Astrophysics Data System (ADS)

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.

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

2014-02-01

106

Lake-effect snowfall in Western New York and surface temperatures of Lakes Erie and Ontario  

E-print Network

Force Environmental Technical Applications Center, the National Climatic Center, the Great Lakes Environmental Research Lab, Mr. George Grisham of Griffiss AFB, Mr. Kurt P. Aiverson of the Buffalo Area Chamber of Commerce, and the Buffalo District.... CONCLUSIONS AND RECOMMENDATIONS 105 a. Conclusions 105 b. Recommendations 107 REFERENCES. 109 APPENDIX A. APPENDIX B. VITA, 114 115 116 LIST OF TABLES Table Title Page Comparati. ve snowfall totals for Buffalo, New York. Characteristics of lake...

Agrella, William

1978-01-01

107

A Physical Model to Determine Snowfall over Land by Microwave Radiometry  

NASA Technical Reports Server (NTRS)

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.

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

2003-01-01

108

Winter Weather  

MedlinePLUS

... Matters What's New A - Z Index Disasters & Severe Weather Earthquakes Extreme Heat Floods Hurricanes Landslides Tornadoes Tsunamis Volcanoes Wildfires Winter Weather Winter Weather Language: English Espaol (Spanish) Recommend on Facebook Tweet ...

109

Total lightning within electrified snowfall using LMA, NLDN and WTLN measurements  

NASA Astrophysics Data System (ADS)

Three electrified snowfall cases are examined using total lightning measurements from lightning mapping arrays (LMAs), the National Lightning Detection Network (NLDN) and the WeatherBug Total Lightning Network (WTLN). Two events are from the Mid-Atlantic region of the US, while the third is from a heavy snowfall event in the Southeast US. In each of these events, electrical activity was in conjunction with heavy snowfall rates, sometimes exceeding 5-8 cm per hour. A combination of LMA, NLDN and WTLN data indicate that many of these flashes initiated from tall communications towers and traveled over large horizontal distances, consistent with flashes in the trailing stratiform regions of mature MCSs. Sequencing of leader development and discharge episodes, and their polarities, are inferred by combining WTLN and LMA. In one extensive tower strike, alternating ground and cloud discharge components stimulated further leader development and ground strikes. During the Southeast US event, the Advanced Radar for Meteorological and Operational Research (ARMOR) C-band dual polarimetric radar was collecting range height indicators (RHIs). The combination of ARMOR dual polarimetric radar and VHF LMA observations suggested contiguous layer changes in height between sloping aggregate-dominated layers and horizontally-oriented crystals. These layers may have provided ideal conditions for the development of extensive regions of charge and resultant horizontal propagation of the lightning flashes over large distances.

Schultz, C. J.; Bruning, E. C.; Carey, L. D.; Petersen, W. A.; Heckman, S.

2011-12-01

110

Weather Support to Deicing Decision Making (WSDDM): A Winter Weather Nowcasting System.  

NASA Astrophysics Data System (ADS)

This paper describes a winter weather nowcasting system called Weather Support to Deicing Decision Making (WSDDM), designed to provide airline, airport, and air traffic users with winter weather information relevant to their operations. The information is provided on an easy to use graphical display and characterizes airport icing conditions for nonmeteorologists. The system has been developed and refined over a series of winter-long airport demonstrations at Denver's Stapleton International Airport, Chicago's O'Hare International Airport, and New York's LaGuardia Airport. The WSDDM system utilizes commercially available weather information in the form of Next Generation Weather Radar WSR-88D radar reflectivity data depicted as color coded images on a window of the display and Aviation Routine Weather Report (METAR) surface weather reports from Automated Surface Observating System stations and observers. METAR information includes wind speed and direction, air temperature, and precipitation type/rate, which are routinely updated on an hourly basis or more frequently if conditions are changing. Recent studies have shown that the liquid equivalent snowfall rate is the most important factor in determining the holdover time of a deicing fluid. However, the current operational snowfall intensity reported in METARs is based on visibility, which has been shown to give misleading information on liquid equivalent rates in many cases due to the wide variation in density and shape of snow. The particular hazard has been identified as high visibility-high snowfall conditions. The WSDDM system addresses this potentially hazardous condition through the deployment of snow gauges at an airport. These snow gauges report real-time estimates of the liquid equivalent snowfall rate once every minute to WSDDM users. The WSDDM system also provides 30-min nowcasts of liquid equivalent snowfall rate through the use of a real-time calibration of radar reflectivity and snow gauge snowfall rate. This paper discusses the development of the system, including the development of new wind shields for snow gauges to improve catch efficiency, as well as the development of the above mentioned real-time method to convert radar reflectivity to snowfall rate on the ground using snow gauges. In addition, we discuss results from a user evaluation of the system, as well as results from an efficiency and safety benefits study of the system.

Rasmussen, Roy; Dixon, Mike; Hage, Frank; Cole, Jeff; Wade, Chuck; Tuttle, John; McGettigan, Starr; Carty, Thomas; Stevenson, Lloyd; Fellner, Warren; Knight, Shelly; Karplus, Eli; Rehak, Nancy

2001-04-01

111

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

NASA Technical Reports Server (NTRS)

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.

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

2008-01-01

112

Winter Storms  

NSDL National Science Digital Library

This site offers general background about winter storms as well as interactive activities to teach visitors about these storms. It also offers a teacher's 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.

1996-01-01

113

Snow climate baseline conditions and trends in Croatia relevant to winter tourism  

NASA Astrophysics Data System (ADS)

The presence of snow along a portion of the Croatian highlands has enabled the development of winter tourism that is primarily oriented toward snow-related activities. Snow is more abundant and stays on the ground longer in the mountainous district of Gorski kotar (south eastern edge of the Alps) and on Mount Velebit (Dinaric Alps), which have elevations of up to 1,600 m and are close to the Adriatic coast than over the inland hilly region of north western Croatia where the summits are not more than approximately 1,000 m high. Basic information about the snow conditions at these locations was gathered for this study, including the annual cycle and probabilities for various snow parameters at different altitudes. As requested by the Croatian Ski Association, the relation between the air temperature and the relative humidity was investigated to determine the feasibility of artificial snowmaking. The snow parameters are highly correlated to air temperature, surface air pressure and precipitation, with certain differences occurring as a result of the altitude. Since the beginning of the second half of the twentieth century, winter warming and a significant increase in the mean air pressure (more anticyclonic situations) have been detected at all sites. Winter precipitation totals decreased at medium altitudes and increased at the summit of Mount Velebit, but these trends were not significant. The frequency of precipitation days and of snowfall decreased whereas an increasing fraction of the precipitation days at high altitudes involved solid precipitation. In contrast, a decreasing fraction of the precipitation days at medium altitudes involved solid precipitation, probably because of the different warming intensities at different altitudes. The mean daily snow depth and the duration of snow cover both slightly decreased at medium altitudes whereas the snow cover duration slightly increased at the mountainous summit of Mount Velebit.

Gaji?-?apka, M.

2011-08-01

114

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

NASA Astrophysics Data System (ADS)

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.

Nol, 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

115

Coupling of winter climate transitions to snow and clouds over the Prairies  

NASA Astrophysics Data System (ADS)

Using data from 13 climate stations on the Canadian Prairies, together with opaque cloud cover and daily snow depth, to analyze the winter climate transitions with snow, we find that a snow cover acts as a fast climate switch. Surface temperature falls by about 10 K with fresh snowfall and rises by a similar amount with snowmelt, while the daily range of relative humidity falls to around 5-15% with snow cover. These are robust climate signals. For every 10% decrease in days with snow cover over the Canadian Prairies, the mean October to April climate is warmer by about 1.4 K. Stratifying by daily mean opaque cloud cover across snow transitions shows the rapid shift within 5 days from a diurnal cycle dominated by shortwave cloud forcing to one dominated by longwave cloud forcing. We calculate the change in the surface radiative budget with snow using surface albedo data from the Moderate Resolution Imaging Spectroradiometer and station longwave data. We find that with the fall-winter snow transitions, the surface radiative heating is reduced by 50 Wm-2, with 69% coming from the reduced net shortwave flux, resulting from the increased surface albedo and a small increase in effective cloud albedo, and 31% from a reduced incoming longwave flux. This drop in surface radiative heating is sufficient to produce a drop in the surface radiometric skin temperature of 11 K. We find that in winter, the monthly mean diurnal climate is more closely coupled to the diurnal shortwave forcing than the mean diurnal climate.

Betts, Alan K.; Desjardins, Raymond; Worth, Devon; Wang, Shusen; Li, Junhua

2014-02-01

116

Winter Thunderstorms  

Microsoft Academic Search

THOSE of your readers who may observe thunderstorms in the British Isles during the winter months would give great assistance to an investigation of thunderstorms on which I am engaged if they would report by postcard when they observe lightning or thunder during this winter. When sheet lightning is observed at night the time and direction should be given, and

Charles J. P. Cave

1915-01-01

117

Winter Weeds.  

ERIC Educational Resources Information Center

Try to learn all you can about a plant in the winter. As the season changes, you can see what the dried seed pod is like in bloom. You are a convert if you notice a spectacular show of summer wildflowers and wonder what sort of winter weed will result. (Author/CM)

Lindberg, Lois

1981-01-01

118

Winter Wonderlands  

ERIC Educational Resources Information Center

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

Coy, Mary

2011-01-01

119

Numerical diagnosis of a heavy snowfall event in the center of the Iberian Peninsula  

NASA Astrophysics Data System (ADS)

On 4 March 2011, an exceptionally heavy snowfall event affected the Madrid region on the central Iberian Peninsula. At altitudes of 1200 m, snowfall reached a record of 34 cm in 24 h and produced considerable damage and disruption to electricity distribution and transport systems. Maximum intensity precipitation was identified between 1600 and 1800 UTC. Associated precipitation was particularly intense in the Guadarrama Mountains (at the center of the Peninsula, near Madrid). Analysis of Meteosat Second Generation (MSG) satellite images revealed a dark area, generated by a stratospheric intrusion originating in the Atlantic and reaching the Iberian Peninsula. We studied synoptic conditions and mesoscale factors involved in the event, using the Weather Research and Forecasting (WRF) model. This permitted analysis of the evolution of the dry intrusion caused by a tropopause fold, its movement, and frontogenesis-related mechanisms during its crossing of the Guadarrama Mountains. The blocking of a wet warm mass at altitude owing to a descent of the tropopause but mainly at low levels because of orographic effects, helped concentrate moisture and generate potential instability (PI). This was subsequently released in deep convection, owing to the formation of frontogenesis.

Gascn, E.; Snchez, J. L.; Charalambous, D.; Fernndez-Gonzlez, S.; Lpez, L.; Garca-Ortega, E.; Merino, A.

2015-02-01

120

Can we estimate precipitation rate during snowfall using a scanning terrestrial LiDAR?  

NASA Astrophysics Data System (ADS)

Accurate snowfall measurements in windy areas have proven difficult. To examine a new approach, we have installed an automatic scanning terrestrial LiDAR at Mammoth Mountain, CA. With this LiDAR, we have demonstrated effective snow depth mapping over a small study area of several hundred m2. The LiDAR also produces dense point clouds by detecting falling and blowing hydrometeors during storms. Daily counts of airborne detections from the LiDAR show excellent agreement with automated and manual snow water equivalent measurements, suggesting that LiDAR observations have the potential to directly estimate precipitation rate. Thus, we suggest LiDAR scanners offer advantages over precipitation radars, which could lead to more accurate precipitation rate estimates. For instance, uncertainties in mass-diameter and mass-fall speed relationships used in precipitation radar, combined with low reflectivity of snow in the microwave spectrum, produce errors of up to 3X in snowfall rates measured by radar. Since snow has more backscatter in the near-infrared wavelengths used by LiDAR compared to the wavelengths used by radar, and the LiDAR detects individual hydrometeors, our approach has more potential for directly estimating precipitation rate. A key uncertainty is hydrometeor mass. At our study site, we have also installed a Multi Angle Snowflake Camera (MASC) to measure size, fallspeed, and mass of individual hydrometeors. By combining simultaneous MASC and LiDAR measurements, we can estimate precipitation density and rate.

LeWinter, A. L.; Bair, E. H.; Davis, R. E.; Finnegan, D. C.; Gutmann, E. D.; Dozier, J.

2012-12-01

121

How does the spaceborne radar blind zone affect derived surface snowfall statistics in polar regions?  

NASA Astrophysics Data System (ADS)

Global statistics of snowfall are currently only available from the CloudSat satellite. But CloudSat cannot provide observations of clouds and precipitation within the so-called blind zone, which is caused by ground-clutter contamination of the CloudSat radar and covers the last 1200 m above land/ice surface. In this study, the impact of the blind zone of CloudSat on derived snowfall statistics in polar regions is investigated by analyzing three 12 month data sets recorded by ground-based Micro Rain Radar (MRR) at the Belgian Princess Elisabeth station in East Antarctica and at Ny-lesund and Longyearbyen in Svalbard, Norway. MRR radar reflectivity profiles are investigated in respect to vertical variability in the frequency distribution, changes in the number of observed snow events, and impacts on total precipitation. Results show that the blind zone leads to reflectivity being underestimated by up to 1 dB, the number of events being altered by 5% and the precipitation amount being underestimated by 9 to 11 percentage points. Besides investigating a blind zone of 1200 m, the impacts of a reduced blind zone of 600 m are also analyzed. This analysis will help in assessing future missions with a smaller blind zone. The reduced blind zone leads to improved representation of mean reflectivity but does not improve the bias in event numbers and precipitation amount.

Maahn, Maximilian; Burgard, Clara; Crewell, Susanne; Gorodetskaya, Irina V.; Kneifel, Stefan; Lhermitte, Stef; Van Tricht, Kristof; Lipzig, Nicole P. M.

2014-12-01

122

An Airborne Profiling Radar Study of the Impact of Glaciogenic Cloud Seeding on Snowfall from Winter Orographic Clouds  

E-print Network

column in Nature, it was argued that ``. . . weather modification is one of those areas in which science the most widely practiced method of intentional weather modification for the last few decades (e variability of weather conditions and the small size of the dataset. 1. Introduction In a 2008 editorial

Geerts, Bart

123

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

NASA Technical Reports Server (NTRS)

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.

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

2004-01-01

124

Summer C Fixation of Salix arctic is Altered by Prior Winter Snow Regimes: Photosynthetic Responses to Long-Term Snow Increases in the High Arctic of NW Greenland  

NASA Astrophysics Data System (ADS)

Climate models and snow measurements on Greenland show increased precipitation in addition to warming in the High Arctic. Because polar semi-deserts may be water limited, additional snow and snow melt water, may alleviate mid-summer drought and promote additional carbon fixation. We investigated the long-term (10 years of experimental snow increases) consequences of additional winter snow as it effects subsequent summer gas exchange of Salix arctica in a polar semi-desert tundra ecosystem in NW Greenland (76.6N, 68.6W). In 2011, measurements of gas exchange physiology were conducted along a transect from high to ambient snow accumulation in mid-July. In 2012, gas exchange was measured in high and ambient snow zones between late June and early August. In 2012, the seasonal patterns of ?18O of xylem water and soil water between 5 and 20 cm below the soil surface was measured to determine if snow accumulation influences the water sources and depth of water used by S. arctica. In 2011, photosynthesis in the deep snow zones was lower than in the ambient snow zone; similar results were observed for leaf N content. Carbon isotope composition (?13C) of S. arctica leaves did not differ between deep and ambient snow zones suggesting a similar season-long relationship between photosynthesis and stomatal conductance in both locations. In 2012, there was a trend towards higher photosynthesis at the height of the growing season in the deep snow zones. Light response curves in 2012 suggest higher maximum photosynthesis in the deep snow zones compared to the ambient zones. Regardless of prior winter snow accumulation, S. arctica appears to derive nearly all its xylem water from the top 5 cm of the soil. There is little evidence that differences in photosynthetic physiology result directly from increased soil moisture associated with high snow, rather the effect appears more complex. Much of the increased snow accumulation will run-off of these systems when the soils are still frozen in the spring. Rather, deeper snow may be changing the soil and plant N cycle and altering the availability of N to plants possibly through the delayed onset of the growing season in high snow zones compared to regions with ambient snow accumulation. Finally, we note that weather differed considerably between 2011 and 2012. In 2011, a typical summer dry period was observed such that soils dried considerably. During 2012, repeated precipitation events from mid-June to late July maintained high soil moisture content. It appears that additional snow accumulation effects on High Arctic plant C fixation may be complex and involve a combined effect on both soil water, soil and plant N dynamics, and the relative effects may be predicated by the quantity and timing of precipitation during the growing season.

Leffler, A.; Welker, J. M.; Sullivan, P. F.; Maseyk, K. S.

2012-12-01

125

Nutrition for winter sports.  

PubMed

Winter sports are played in cold conditions on ice or snow and often at moderate to high altitude. The most important nutritional challenges for winter sport athletes exposed to environmental extremes include increased energy expenditure, accelerated muscle and liver glycogen utilization, exacerbated fluid loss, and increased iron turnover. Winter sports, however, vary greatly regarding their nutritional requirements due to variable physiological and physique characteristics, energy and substrate demands, and environmental training and competition conditions. What most winter sport athletes have in common is a relatively lean physique and high-intensity training periods, thus they require greater energy and nutrient intakes, along with adequate food and fluid before, during, and after training. Event fuelling is most challenging for cross-country skiers competing in long events, ski jumpers aiming to reduce their body weight, and those winter sport athletes incurring repeated qualification rounds and heats. These athletes need to ensure carbohydrate availability throughout competition. Finally, winter sport athletes may benefit from dietary and sport supplements; however, attention should be paid to safety and efficacy if supplementation is considered. PMID:22150424

Meyer, Nanna L; Manore, Melinda M; Helle, Christine

2011-01-01

126

Surviving Winter  

NSDL National Science Digital Library

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.

2010-11-17

127

Nuclear Winter.  

ERIC Educational Resources Information Center

"Nuclear Winter" was recently coined to describe the climatic and biological effects of a nuclear war. These effects are discussed based on models, simulations, scenarios, and projections. Effects on human populations are also considered. (JN)

Ehrlich, Anne

1984-01-01

128

Winter Weather  

NSDL National Science Digital Library

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 affects our everyday lives. Some days it's sunny and some days its not. The years weather is split up into seasons. 1. What are the four seasons? 2. What kind of weather do you see in the summer? 3. What kind of weather is unique to winter? 4. ...

Mrs. Bellows

2009-09-28

129

Characteristics of large snowfall events in the montane western United States as examined using snowpack telemetry (SNOTEL) data  

Microsoft Academic Search

Daily snow water equivalent records from the snowpack telemetry archive are used to assess spatiotemporal characteristics of large snowfall events over the montane western United States. The largest mean annual (leading) events are found in the Pacific Northwest and Sierra Nevada. The mean leading event lasting up to 72 hours typically accounts for 10-23% of the water equivalent of annual

Mark C. Serreze; Martyn P. Clark; Allan Frei

2001-01-01

130

Winter range arrival and departure of white-tailed deer in northeastern Minnesota  

USGS Publications Warehouse

I analyzed 364 spring and 239 fall migrations by 194 white-tailed deer (Odocoileus virginianus) from 1975 to 1993 in northeastern Minnesota to determine the proximate cause of arrivals on and departures from winter ranges. The first autumn temperatures below -7?C initiated fall migrations for 14% (95% confidence interval (CI) = 0-30) of female deer prior to snowfall in three autumns, but only 2% remained on winter ranges. During 14 autumns, the first temperatures below -7?C coincidental with snowfalls elicited migration in 45% (95% CI = 34-57) of females, and 91 % remained on winter ranges. Arrival dates failed to correlate with independent variables of temperature and snow depth, precluding predictive modeling of arrival on winter ranges. During 13 years, a mean of 80% of females permanently arrived on winter ranges by 31 December. Mean departure dates from winter ranges varied annually (19 March - 4 May) and between winter ranges (14 days) and according to snow depth (15-cm differences). Only 15 - 41 % of deer departed when snow depths were> 30 cm but 80% had done so by the time of lO-cm depths. Mean weekly snow depths in March (18-85 cm) and mean temperature in April (0.3 -8.1 ?c) explained most of the variation in mean departure dates from two winter ranges (Ely, R2 = 0.87, P < 0.0005, n = 19 springs; Isabella, R2 = 0.85, P = 0.0001, n = 12 springs). Mean differences between observed mean departure dates and mean departure dates predicted from equations ranged from 3 days (predictions within the study area) to 8 days (predictions for winter ranges 100-440 km distant).

Nelson, M.E.

1995-01-01

131

The motion of mesoscale snowbands in Northeast U.S. winter storms  

NASA Astrophysics Data System (ADS)

The distribution of snowfall accumulation attending winter storms is a product of both precipitation intensity and duration. Many heavy snowfall events are associated with distinct mesoscale snowbands that strongly modulate snowfall accumulation. Mesoscale snowbands are known to be favored within environments characterized by frontogenesis in the presence of weak moist symmetric or gravitational stabilities. Although the development of mesoscale snowbands often can be anticipated at 24--36-h ranges, anticipating band residence time at a fixed location remains a forecasting challenge. However, given that snowband residence time is related to characteristics of band motion, improved understanding of band motion presents an opportunity to improve snowfall accumulation forecasts. This study investigates environmental attributes associated with specific snowband motion characteristics. A classification scheme for snowband motion is developed, wherein bands are categorized into four modes: laterally translating, laterally quasi-stationary, pivoting, and hybrid. Laterally translating bands exhibit predominantly cross-axis motion, thereby favoring quasi-uniform snowfall accumulation along their paths. In contrast, laterally quasi-stationary bands are characterized by near-zero cross-axis motion, favoring heavy snowfall accumulation along a narrow corridor that may extend for several hundred kilometers. Pivoting bands exhibit pronounced rotation such that heavy snowfall accumulation is particularly favored near the center of rotation. Finally, hybrid bands are dominated by along-axis motion, but with a concurrent cross-axis component of motion. Using archived WSR-88D data, snowband events in the northeast U.S. between 2005 and 2010 have been subjectively identified and classified according to this scheme. Gridded data from the 0.5 resolution NCEP Climate Forecast System Reanalysis are used to identify environmental features associated with band motion characteristics. Results indicate that patterns of the low-to-midlevel kinematic fields, temperature advection, along- and cross-isentrope projections of the Q vector, and vertical wind shear in the near-band environment are useful in distinguishing between snowband modes. Composite fields, case studies, and conceptual models are presented to illustrate synoptic-scale features associated with different snowband motion characteristics.

Kenyon, Jaymes S.

132

Winter Hydrographer  

USGS Multimedia Gallery

Robert Bradley, a hydrologic technician with the Massachusetts USGS Office, headed to Maine to experience a winter ice measurement trip with Laura Flight, a hydrologic technician from the Maine USGS Office. Robert, originally from Florida, went to Aroostook County with Laura and got smacked in the f...

133

Winter Workshop.  

ERIC Educational Resources Information Center

Materials on 11 topics presented at a winter workshop for Quebec outdoor educators have been compiled into this booklet. Action story, instant replay, shoe factory, sound and action, and find an object to fit the description are described and recommended as group dynamic activities. Directions for five games (Superlative Selection; Data

Council of Outdoor Educators of Quebec, Montreal.

134

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.

135

Winter Games.  

ERIC Educational Resources Information Center

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,

Tarbuth, Lawson, Comp.

136

Monitoring a convective winter episode of the Iberian Peninsula using a multichannel microwave radiometer  

NASA Astrophysics Data System (ADS)

On 4 March 2011, a heavy snowfall episode affected the central Iberian Peninsula. Under the TECOAGUA Project (aimed at the study of winter cloud masses that produce snow in the Guadarrama Mountains near Madrid), measurements using a ground-based multichannel microwave radiometer (MMWR) with vertical range 10 km recorded this episode of winter convection embedded within stratiform precipitation. In contrast to radiosondes, data retrieval from the MMWR has a clear advantage for identifying hazardous weather phenomena of short duration, such as winter convective episodes. From these continuous measurements, we analyzed the behavior of variables such as temperature, surface pressure, relative humidity, liquid water content, liquid water path, water vapor content, and integrated water vapor throughout the day. The continuous measurements also permitted construction of skew-T log-P profiles every 15 min during the convective episode, indicating vertical evolution of an event with an appearance similar to a "zipper" in which temperature and dew point temperature profiles are "closed" from the surface to 400 hPa and "reopen" at the end of the event. Finally, we selected six indices of stability most suitable for the study of winter convection, namely, the Showalter index, low-topped convection index, most unstable lifted index, most unstable convective available potential energy (MUCAPE), convective inhibition, and MUCAPE level of free convection. Each of these indices has been evaluated for their capacity to warn of meteorological conditions leading to a convective heavy snowfall event.

Gascn, E.; Snchez, J. L.; Fernndez-Gonzlez, S.; Hermida, L.; Lpez, L.; Garca-Ortega, E.; Merino, A.

2015-02-01

137

The Impacts of Changes in Snowfall on Soil Greenhouse Gas Emissions Using an Automated Chamber System  

NASA Astrophysics Data System (ADS)

Snow cover has decreased in many regions of the northern hemisphere and is projected to decrease further in most. The reduced snow cover may enhance soil freezing and increase the depth of frost. The frequency of freeze-thaw cycles is likely to increase due to the reduction of snowpack thickness. Freeze and thaw cycles can strongly affect soil C and N dynamics. The pulses of N2O and CO2 emissions from soil after thawing have been reported in various studies. However, most studies were based on the controlled laboratory conditions or low resolution static chamber methods in situ. Near-continuous automated chambers provide the temporal resolution needed for capturing short-lived pulses of greenhouse gases after intermittent melting events. We investigated the winter and spring response of soil greenhouse gas emissions (CO2, CH4 and N2O) to changes of snow depth using an automated chamber system. This study was established in 2010 at the Kellogg Biological Station (KBS) in southwest Michigan. The plot was no till rotational (corn-soybean-wheat) cropland, most recently in corn. The experiment was a completely randomized design (CRD) with three levels of snow depth: ambient, double, and no snow. Each level had four replicates. Twelve automated chambers were randomly assigned to treatments and greenhouse gas fluxes measured 4 times per day in each plot. There were more freeze-thaw cycles in the no snow treatment than in the ambient and double snow treatments. Soil temperature at 5 cm depth was more variable in the no snow treatment than in the ambient and double snow treatments. CH4 fluxes were uniformly low with no significant difference across three treatments. CO2 showed expected seasonal changes with the highest emission in spring and lowest emissions through the winter. N2O peaks were higher in spring due to freeze thaw effects and cumulative N2O fluxes were substantially higher in the no snow treatment than in the ambient and double snow treatments.

Ruan, L.; Kahmark, K.; Robertson, G.

2012-12-01

138

Winter Storms  

NSDL National Science Digital Library

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 ...

Mr. Sappa

2010-05-26

139

Winter Storm  

NSDL National Science Digital Library

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? ...

Miss Smith

2010-09-27

140

Winter Storm  

NSDL National Science Digital Library

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 ...

Ashley Schilling

2010-05-26

141

Winter Storm  

NSDL National Science Digital Library

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 ...

Miss Liz

2010-05-26

142

Winter snow  

NSDL National Science Digital Library

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 ...

Lori Peterson

2009-09-28

143

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

NASA Astrophysics Data System (ADS)

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.

Changnon, Stanley A.; Changnon, David

2005-09-01

144

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

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

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

1984-01-01

145

Insulation grapes cold winter effect  

NASA Astrophysics Data System (ADS)

Purposes: The study of several insulation in cold conditions in Xinjiang Gobi Grape safe winter effect. Procedures and Method: The use of real-time U-plate thermometer to measure temperature changes recorded instrument to study the severe winter conditions, several insulation effect at different depths of grape root, and the cold resistance of winter grape roots at different depths variation; research in the coming year the spring and summer seasons, blooming the results of several insulation grape growth and development. Results: Several insulation Gobi Grape security winter better, surface temperature is largely improved compared with the control. The D900 collodions+ enhanced membrane to improve the 11.69C, non-woven + buried improve the 10.09C. D900 no glue cotton + enhanced membrane covering the grape surface <=-5C continuous days of relatively non-woven + buried reduce eight days underground 30cm, a decrease of 5 days. D900 no glue cotton + Enhanced membrane covering the minimum grape underground temperature than the non-woven+ buried there is a significant improvement of the surface temperature has increased 1.57C, the underground at 30 cm temperature has increased 1.08C, 60cm, underground buried than the processing temperature has increased 1.54C, the insulation effect. Conclusions: Xinjiang cold conditions, the D900 without glue cotton+ film way cover the grapes can live through the winter, is to protect the winter safety of the grapes and grape production.

Guo, Shao-jie; Li, Ming; Ying, Liang-fu

146

Total Lightning Observations within Electrified Snowfall using Polarimetric Radar LMA, and NWN Measurements  

NASA Technical Reports Server (NTRS)

Tall structures play and important role in development of winter time lightning flashes.To what extent still needs to be assessed. Tower initiated flashes typically occur as banded structures pass near/overhead. Hi resolution RHI s from polarimetric radar show that the lightning has a tendency to propagate through layered structures within these snowstorms.

Schultz, Christopher J.; Bruning, Eric C.; Carey, Lawrence D.; Blakeslee, Richard J.

2013-01-01

147

Evaluation of DFIR and Bush Gauge Snowfall Measurements at Boreal Forest Sites in Saskatchewan/Canada and Valdai/Russia  

NASA Astrophysics Data System (ADS)

Snowfall is important to cold region climate and hydrology including Canada. Large uncertainties and biases exist in gauge-measured precipitation datasets and products. These uncertainties affect important decision-making, water resources assessments, climate change analyses, and calibrations of remote sensing algorithms and land surface models. Efforts have been made at both the national and international levels to quantity the errors/biases in precipitation measurements, such as the WMO Solid Precipitation Intercomparison Experiment (WMO-SPICE). Both the DFIR (double fence intercomparison reference) and the bush shielded gauge have been used in the past as a reference measurement for solid precipitation and they both have been selected as the references for the current SPICE project. Previous analyses of the DFIR vs. the bush (manual Tretyakov) gauge data collected at the Valdai station in Russia suggest DFIR undercatch of snowfall by up to 10% for high wind conditions. A regression relationship between the 2 systems was derived and used for the last WMO gauge intercomparison. Given the importance of the DFIR as the reference for the WMO SPICE project, it is necessary to re-examine and update the DFIR and bush gauge relationship. As part of Canada's contribution to the WMO SPICE project, a test site has been set up by EC/ASTD/WSDT in the southern Canadian Boreal forest to compare the DFIR and bush gauges. This site, called the Caribou Creek, has been installed within a modified young Jack Pine forest stand - north of Prince Albert in Saskatchewan. This study compiles and analyzes recent DFIR and bush gauge data from both the Valdai and Caribou Creek sites. This presentation summarizes the results of data analyses, and evaluates the performance of both references for snowfall observations in the northern regions. The methods and results of this research will directly support the WMO SPICE project and contribute to cold region hydrology and climate change research.

Yang, D.; Smith, C.

2013-12-01

148

Evolution of summer Arctic sea ice albedo in CCSM4 simulations: Episodic summer snowfall and frozen summers  

NASA Astrophysics Data System (ADS)

albedo of Arctic sea ice is calculated from summertime output of twentieth century Community Climate System Model v.4 (CCSM4) simulations. This is compared with an empirical record based on the generalized observations of the summer albedo progression along with melt onset dates determined from remote sensing. Only the contributions to albedo from ice, snow, and ponds are analyzed; fractional ice area is not considered in this assessment. Key factors dictating summer albedo evolution are the timing and extent of ponding and accumulation of snow. The CCSM4 summer sea ice albedo decline was found, on average, to be less pronounced than either the empirical record or the CLARA-SAL satellite record. The modeled ice albedo does not go as low as the empirical record, nor does the low summer albedo last as long. In the model, certain summers were found to retain snow on sea ice, thus inhibiting ice surface melt and the formation or retention of melt ponds. These "frozen" summers were generally not the summers with the largest spring snow accumulation, but were instead summers that received at least trace snowfall in June or July. When these frozen summers are omitted from the comparison, the model and empirical records are in much better agreement. This suggests that the representation of summer Arctic snowfall events and/or their influence on the sea ice conditions are not well represented in CCSM4 integrations, providing a target for future model development work.

Light, Bonnie; Dickinson, Suzanne; Perovich, Donald K.; Holland, Marika M.

2015-01-01

149

Catastrophic winter storms: An escalating problem  

Microsoft Academic Search

Winter storms are a major weather problem in the USA and their losses have been rapidly increasing. A total of 202 catastrophic\\u000a winter storms, each causing more than $1 million in damages, occurred during 19492003, and their losses totaled $35.2 billion\\u000a (2003 dollars). Catastrophic winter storms occurred in most parts of the contiguous USA, but were concentrated in the eastern

2007-01-01

150

Efficient N Management Using Winter Oilseed Rape  

Microsoft Academic Search

\\u000a During the last decades the acreage of winter oilseed rape has been increased considerably in Europe. Rapeseed can take up\\u000a a large amount of nitrogen before winter (?>?100kgN???ha) and thus prevent nitrate leaching and pollution. Winter wheat\\u000a is often grown subsequently, using oilseed rape as a favorable preceding crop. However, under wheat large nitrogen losses\\u000a via leaching are frequently observed

Klaus Sieling; Henning Kage

151

Ross River virus infection surveillance in the Greater Perth Metropolitan area--has there been an increase in cases in the winter months?  

PubMed

An increase in off-season (June to September) Ross River virus (RRV) notifications from the greater Perth metropolitan area was observed from 2006 to 2009. We investigated the increase to determine whether it is likely to have reflected a true increase in off-season cases. A single positive RRV IgM test result is sufficient for RRV notification but where follow-up testing was performed, the positive predictive value of an IgM test where IgG was negative was very low in the off-season and also in the season when using the only commercially available test kit. The increase in off-season notifications was not associated with an increase in off-season testing. Some Perth laboratories use more stringent notification criteria than the nationally agreed RRV case definition, and the geographical distribution of samples tested varies between laboratories. Our findings make a strong case to change the nationally agreed case definition for RRV to not accept a single IgM positive test result as laboratory definitive evidence where the IgG is negative. Our study also identified a range of challenges in interpreting changes in seasonal patterns and geographical distribution of RRV. Any such observed changes should be investigated through further data analysis and/or mosquito trapping and testing in order to assess validity. PMID:25222206

Selvey, Linda A; Donnelly, Jenny A; Lindsay, Michael D; PottumarthyBoddu, Sudha; D'Abrera, Victoria C; Smith, David W

2014-06-01

152

Changes in natural development of shores caused by artificial disturbance, increased cyclonic activity and related warmer winters in the Sillame case study area (Estonia, Gulf of Finland, Baltic Sea)  

NASA Astrophysics Data System (ADS)

Prior to the founding of the town of Sillame in 1946 when a waste depository facility was constructed across the sediment path moving along the shore on Cape Pite, the shores nearby were one litho dynamic system with good natural balance. The shores there today are no longer in a state of dynamic equilibrium. This study analyzes how construction along the shore, increased cyclonic activity and related warmer winters has affected Sillamae's shores and how the shores are likely to evolve in the future. One of the aims is to detect the share of each factor to the the total changes on the shores of that specific location and compare the results with the previous studies carried out in more opened shores in west Estonian Archipelago. For purposes of this study, we undertook field observations to measure changes in the rate of erosion and accumulation of shore sediment. Waste depository is conserved and its shores are well protected by now. Sillame harbor has been established at the same place. Our analysis of shore processes and our direct observations indicate that the shores east of the harbor are still strongly influenced by the sea and far from dynamical equilibrium. Over the last few decades, the average date by which the Gulf of Finland has gradually shifted from December to January, and the average date by which such ice begins to break-up has shifted earlier. As a result, the period during which wave action is free to impact the coast is longer. Such greater lack of ice cover is exposing the shores to more stormy winter months. Accordingly, as a result of increasing cyclonic activity the development of the shores in Sillame has accelerated and the areas affected by erosion are widening.

Tnisson, Hannes; Kont, Are; Rivis, Reimo; Orviku, Kaarel; Suursaar, lo; Jaagus, Jaak

2010-05-01

153

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)

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.

Rasmussen, R.; Grubisic, V.

2010-09-01

154

NORTHWARD EXPANSION OF THE WINTERING RANGE OF RICHARDSON'S MERLIN  

Microsoft Academic Search

The wintering range of Richardson's Merlin (Falco columbarius richardsonii) has recently been acknowledged to include the Canadian prairies. An analysis of Christmas Bird Counts over a 27-year period revealed that these Merlin populations have significantly increased in Canadian urban counts, and farther south on United States counts in the more traditional wintering range. The increase in wintering Merlins in the

PAUL C. JAMES; LYNN W. OLIPHANT; IAN G. WAtIENWIN

155

High Resolution Simulation of Annual Snowfall and Snowpack over Colorado and some Impacts of Climate Change using the Pseudo Climate Simulation Method  

NASA Astrophysics Data System (ADS)

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). 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. Colorados headwaters region is dominated by high altitude snow melt, so climate assessments in this region using global models are particularly uncertain. 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.

Rasmussen, R.; Ikeda, K.; Liu, C.; Gochis, D.; Chen, F.; Tewari, M.; Dudhia, J.; Thompson, G.; Barlage, M. J.; Miller, K.; Yates, D.; Grubisic, V.; Arsenault, K.

2009-12-01

156

The effect of topography and sea surface temperature on heavy snowfall in the Yeongdong region: A case study with high resolution WRF simulation  

NASA Astrophysics Data System (ADS)

An analysis of the heavy snowfall that occurred on 11-14 February 2011 in the Yeongdong region along the eastern coast is presented. Relevant characteristics based on observation and model simulations are discussed with a focus on the times of maximum snowfall in Gangneung (GN) and Daegwallyong (DG). This event was considered part of the typical snowfall pattern that frequently occurs in the Yeongdong region due to the prevailing northeasterly flow. The control simulation using the high resolution Weather Research and Forecasting (WRF) model (1 km 1 km) showed reasonable performance in capturing the spatial distribution and temporal evolution of precipitation. The area of precipitation maxima appeared to propagate from the plain coastal region further into the inland mountainous region, in relation to the location of convergence zone. In addition, a series of sensitivity experiments were performed to investigate the effect of topography and sea surface temperature (SST) on the formation of heavy snowfall. The change of topography tended to modulate the topographically induced mechanical flow, and thereby modify the precipitation distribution, which highlights the importance of an elaborate representation of the topography. On the other hand, the sensitivity experiment to prescribe positive (negative) SST forcing shows the enhanced (suppressed) precipitation amount due to the change of the sensible and latent heat fluxes.

Jung, Sun-Hee; Im, Eun-Soon; Han, Sang-Ok

2012-08-01

157

Winter Weather Emergencies  

MedlinePLUS

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

158

Nutrition Frontiers - Winter 2010  

Cancer.gov

Nutrition Frontiers - Winter 2010 Winter 2010 Volume 1, Issue 1 Dear Colleague, Welcome to the first issue of Nutrition Frontiers, a quarterly newsletter from the Nutritional Science Research Group (NSRG), Division of Cancer Prevention, NCI. In this

159

Winter and Summer Views of the Salt Lake Region  

NASA Technical Reports Server (NTRS)

Magnificent views of the region surrounding Salt Lake City, Utah are captured in these winter and summer images from the Multi-angle Imaging SpectroRadiometer's vertical-viewing (nadir) camera. Salt Lake City, situated near the southeastern shore of the Great Salt Lake, is host to the 2002 Winter Olympic Games, which open Friday, February 8. Venues for five of the scheduled events are at city (indoor) locations, and five in mountain (outdoor) facilities. All ten can be found within the area contained in these images. Some of the outdoor events take place at Ogden, situated north of Salt Lake City and at Park City, located to the east. Salt Lake City is surrounded by mountains including the Wasatch Range to the east, and the temperature difference between the Great Salt Lake and the overlying atmosphere enhances the moisture content of winter storms. These factors, in combination with natural cloud seeding by salt crystals from the lake, are believed to result in greater snowfall in neighboring areas compared to more distant locales. In addition to the obvious difference in snow cover between the winter and summer views, water color changes in parts of the Great Salt Lake are apparent in these images. The distinctly different coloration between the northern and southern arms of the Great Salt Lake is the result of a rock-filled causeway built in 1953 to support a permanent railroad. The causeway has resulted in decreased circulation between the two arms and higher salinity on the northern side. The southern part of the lake includes the large Antelope Island, and at full resolution a bridge connecting it to the mainland can be discerned. These images are natural color views acquired on February 8, 2001 and June 16, 2001, respectively. Each image represents an area of about 220 kilometers x 285 kilometers. Image courtesy NASA/GSFC/LaRC/JPL, MISR Team.

2002-01-01

160

Winter QPF Sensitivities to Snow Parameterizations and Comparisons to NASA CloudSat Observations  

NASA Technical Reports Server (NTRS)

Steady increases in computing power have allowed for numerical weather prediction models to be initialized and run at high spatial resolution, permitting a transition from larger scale parameterizations of the effects of clouds and precipitation to the simulation of specific microphysical processes and hydrometeor size distributions. Although still relatively coarse in comparison to true cloud resolving models, these high resolution forecasts (on the order of 4 km or less) have demonstrated value in the prediction of severe storm mode and evolution and are being explored for use in winter weather events . Several single-moment bulk water microphysics schemes are available within the latest release of the Weather Research and Forecast (WRF) model suite, including the NASA Goddard Cumulus Ensemble, which incorporate some assumptions in the size distribution of a small number of hydrometeor classes in order to predict their evolution, advection and precipitation within the forecast domain. Although many of these schemes produce similar forecasts of events on the synoptic scale, there are often significant details regarding precipitation and cloud cover, as well as the distribution of water mass among the constituent hydrometeor classes. Unfortunately, validating data for cloud resolving model simulations are sparse. Field campaigns require in-cloud measurements of hydrometeors from aircraft in coordination with extensive and coincident ground based measurements. Radar remote sensing is utilized to detect the spatial coverage and structure of precipitation. Here, two radar systems characterize the structure of winter precipitation for comparison to equivalent features within a forecast model: a 3 GHz, Weather Surveillance Radar-1988 Doppler (WSR-88D) based in Omaha, Nebraska, and the 94 GHz NASA CloudSat Cloud Profiling Radar, a spaceborne instrument and member of the afternoon or "A-Train" of polar orbiting satellites tasked with cataloguing global cloud characteristics. Each system provides a unique perspective. The WSR-88D operates in a surveillance mode, sampling cloud volumes of Rayleigh scatterers where reflectivity is proportional to the sixth moment of the size distribution of equivalent spheres. The CloudSat radar provides enhanced sensitivity to smaller cloud ice crystals aloft, as well as consistent vertical profiles along each orbit. However, CloudSat reflectivity signatures are complicated somewhat by resonant Mie scattering effects and significant attenuation in the presence of cloud or rain water. Here, both radar systems are applied to a case of light to moderate snowfall within the warm frontal zone of a cold season, synoptic scale storm. Radars allow for an evaluation of the accuracy of a single-moment scheme in replicating precipitation structures, based on the bulk statistical properties of precipitation as suggested by reflectivity signatures.

Molthan, Andrew; Haynes, John M.; Jedlovec, Gary J.; Lapenta, William M.

2009-01-01

161

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

NASA Astrophysics Data System (ADS)

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.

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

2009-12-01

162

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

E-print Network

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

Levermann, Anders

163

Evolution of MLS Ozone and the Polar Vortex During Winter  

NASA Technical Reports Server (NTRS)

The evolution of polar ozone observed by the Upper Atmosphere Research Satellite Microwave Limb Sounder is described for the northern hemisphere (NH) winters of 1991/1992, 1992/1993, and 1993/1994, and the southern hemisphere (SH) winters of 1992 and 1993. Ozone in the mid-stratospheric vortex increases over the winter, with largest increases associated with stratospheric warmings, and a much larger increase in the NH than in the SH.

Manney, G. L.; Froidevaux, L.; Waters, J. W.; Zurek, R. W.

1994-01-01

164

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

NASA Astrophysics Data System (ADS)

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.

Jeffery, N.; Hunke, E. C.

2014-09-01

165

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

PubMed

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

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

2014-11-01

166

Winter 2014 Economics 471  

E-print Network

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

Carter, John

167

Winter Olympic Sports  

NSDL National Science Digital Library

Exploring Winter Olympic Sports Let's take a look at some of the different winter olympic sports Alpine Skiing Biathalon Bobsleigh Cross country Curling Figure Skating Freestyle skiing Ice Hockey Luge Nordic Combined Short track speed skating Skeleton Ski Jumping Snowboard Speed Skating ...

Mrs. Keller

2010-01-23

168

Winter 2013 + Dream scholarships  

E-print Network

Winter 2013 + Dream scholarships + Autism spectrum disorder + Teen sleep + 2011-12 donor roster from around CEHD 6 research highlights Autism spectrum disorder, resilience, concussions, and more 20 of tested federal TRiO programs 18 a long winter's nap Q&A with Kyla Wahlstrom about teen sleep, school

Ciocan-Fontanine, Ionut

169

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....

170

Winter Math Activities  

NSDL National Science Digital Library

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.

Terry Kawas

2013-01-01

171

Winter Art Education Project  

ERIC Educational Resources Information Center

The purpose of this article is to describe how the Department of Art Education at the University of Lapland in Finland has developed winter art as a method of environmental and community-based art education. I will focus on the Snow Show Winter Art Education Project, a training project funded by the European Union and the State Provincial Office

Jokela, Timo

2007-01-01

172

Winter, Your Car, and You  

MedlinePLUS

... Toggle navigation Public News and Resources Winter Your Car and You Winter, Your Car and You Start with a checkup that includes: ... a car shut. News and Resources Winter Your Car and You Get the Facts This page is ...

173

Lessons learned from the snow emergency management of winter season 2008-2009 in Piemonte  

NASA Astrophysics Data System (ADS)

The winter season 2008-2009 has been characterized by heavy snowfalls over the whole Piemonte, in the Western Alps region. The snowfalls have been exceptional because of their earliness, persistence and intensity. The impact on the regional environment and territory has been relevant, also from the economical point of view, as well as the effort of the people involved in the forecasting, prevention and fighting actions. The environmental induced effects have been shown until late spring. The main critical situations have been arisen from the snowfalls earliness in season, the several snow precipitation events over the plains, the big amount of snow accumulation on the ground, as well as the anomaly with respect to the last 30 years climatic trend of snow conditions in Piemonte. The damage costs to the public property caused by the snowfalls have been estimated by the Regione Piemonte to be 470 million euros, giving evidence of the real emergency dimension of the event, never occurred during the last 20 years. The technical support from the Regional Agency for Environmental Protection of Regione Piemonte (Arpa Piemonte) to the emergency management allowed to analyse and highlight the direct and induced effects of the heavy snowfalls, outlining risk scenarios characterized by different space and time scales. The risk scenarios deployment provided a prompt recommendation list, both for the emergency management and for the natural phenomena evolution surveillance planning to assure the people and property safety. The risk scenarios related to the snow emergency are different according to the geographical and anthropic territory aspects. In the mountains, several natural avalanche releases, characterized frequently by a large size, may affect villages, but they may also interrupt the main and secondary roads both down in the valleys and small villages road access, requiring a long time for the complete and safe snow removal and road re-opening. The avalanches often cause the service breakdowns and damage the infrastructures in the built-up areas and the forest heritage. Critical situations due to the snow loading and the snow removal necessity involve all the mountain people directly. Over the plain and the hill country, where the new snow density is generally high giving rise to effects related to its load capacity, to the isolation of little residential and rural settlements, several damages on the secondary road system due to the tree and tree branch falls comes up , together with many public services interruptions (electric power and telephone), warehouse and barn collapses, determining a widespread critical situation. The urban and commuting traffic during the snow emergency enhances the difficulties related to the road management and traffic control over the whole road system in the plains, even with little snow accumulation on the ground. Critical situations may also arise from road frost and intense freezing spells. The operational implementation of the technical rules for the snow emergency management, tested the first time during the event in a dynamic way, pointed out its drawbacks and potentiality, highlighting the "emergency preparedness" importance at different institutional levels, with the population and stakeholder involvement. Some measures have to be especially underlined: the coordination of the snow monitoring over the territory performed by the local operators (avalanche activity and linked damages reporting) and the steps taken locally; the improvement of the tools for the snow pack evaluation to drive the avalanche artificial triggering off, in case of snow mass hazard assessment, and their regional coordination. Moreover it is important to define the standard, acknowledged and accepted prevention actions suited to minimize the heavy snowfall effects, with particular attention to the viableness,to the school systemopening/closing and to the preventive information care in order to avoid the missing perception of the risk. Special attention must be paid to the hydrogeological risk condition ass

Bovo, Dr.; Pelosini, Dr.; Cordola, Dr.

2009-09-01

174

Impacts of a Destructive and Well-Observed Cross-Country Winter Storm.  

NASA Astrophysics Data System (ADS)

A winter storm that crossed the continental United States in mid-February 1990 produced hazardous weather across a vast area of the nation. A wide range of severe weather was reported, including heavy snowfall; freezing rain and drizzle; thunderstorms with destructive winds, lightning, large hail, and tornadoes; prolonged heavy rain with subsequent flooding; frost damage to citrus orchards; and sustained destructive winds not associated with thunderstorms. Low-end preliminary estimates of impacts included 9 deaths, 27 injuries, and $120 million of property damage. At least 35 states and southeastern Canada were adversely affected. The storm occurred during the field operations of four independent atmospheric research projects that obtained special, detailed observations of it from the Rocky Mountains to the eastern great Lakes.

Martner, Brooks E.; Rauber, Robert M.; Ramamurthy, Mohan K.; Rasmussen, Roy M.; Prater, Erwin T.

1992-02-01

175

Winter Storm Fire Safety  

MedlinePLUS

... electrical fires. Encourage safe holiday decoration displays, including candles. Suggest ways to safely cook indoors. Outreach materials ... fire #safetytip: always use a flashlight - not a candle - for emergency lighting. Facebook During a winter storm, ...

176

The Winter Is Past.  

ERIC Educational Resources Information Center

Teacher, writer, and naturalist Phyllis S. Busch takes the reader on an early evening woodland walk in March, describing the many changes in plants and animals that are perceptible by sight, smell, and sound as nature awakens from winter. (NEC)

Busch, Phyllis S.

1985-01-01

177

Water transport under winter conditions  

Microsoft Academic Search

Winter as well as summer floods result in soil loss and sedimentation. Up to now the winter events cannot be adequately predicted. This paper focuses on the infiltration processes under frozen winter conditions in order to model soil erosion processes in winter by adapting the computer model EROSION 3D [Schmidt, J., Werner, M. v., 2000. Modeling Sediment and Heavy Metal

Astrid Weigert; Jrgen Schmidt

2005-01-01

178

Science of Winter  

NSDL National Science Digital Library

Is it true that no two snowflakes are alike? What happens to mosquitoes when the mercury drops? National Geographic Channel explores the planet's most extreme season. This engaging three-minute video discusses the astronomical basis for winter, and other seasons, based on the angle of incidence of the sun's rays relative to the Northern and Southern Hemispheres, as well as the components of intense winter storms.

179

Winter Storm Activity  

NSDL National Science Digital Library

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 affects our everyday lives. Some days it's sunny and some days its not. The years weather is split up into seasons. 1. What are the four seasons? 2. What kind of weather do you see in the summer? 3. What kind of weather is unique to winter? 4. What ...

Jennifer Haight

2010-02-22

180

The long summer: pre-wintering temperatures affect metabolic expenditure and winter survival in a solitary bee.  

PubMed

The impact of climate change on insect populations depends on specific life cycle traits and physiological adaptations. The solitary bee Osmia lignaria winters as a pre-emergent adult, and requires a period of cold temperature for winter diapause completion. It is a univoltine species, and diapause induction does not depend on photoperiod. To understand the potential effects of longer summers on O. lignaria populations, we exposed individuals to three treatments simulating early, mid and late winter arrivals, and measured respiration rates, metabolic expenditure, weight loss, fat body depletion, lipid levels and winter mortality. The early-winter treatment disrupted diapause development, but had no apparent negative effects on fitness. In contrast, late-winter bees had a greater energetic expenditure (1.5-fold), weight (1.4-fold) and lipid (2-fold) loss, greater fat body depletion, and a 19% increase in mortality compared to mid-winter bees. We also monitored adult eclosion and arrival of winter temperatures under natural conditions in four years. We found a positive correlation between mean degree-day accumulation during pre-wintering (a measure of asynchrony between adult eclosion and winter arrival) and yearly winter mortality. Individually, bees experiencing greater degree-day accumulations exhibited reduced post-winter longevity. Timing of adult eclosion in O. lignaria is dependent on the duration of the prepupal period, which occurs in mid-summer, is also diapause-mediated, and is longer in populations from southerly latitudes. In a global warming scenario, we expect long summer diapause phenotypes to replace short summer diapause phenotypes, effectively maintaining short pre-wintering periods in spite of delayed winter arrivals. PMID:21910996

Sgolastra, Fabio; Kemp, William P; Buckner, James S; Pitts-Singer, Theresa L; Maini, Stefano; Bosch, Jordi

2011-12-01

181

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

NASA Astrophysics Data System (ADS)

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.

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

2012-12-01

182

Winter and Summer Views of the Salt Lake Region  

NASA Technical Reports Server (NTRS)

Magnificent views of the region surrounding Salt Lake City, Utah are captured in these winter and summer images from the Multi-angle Imaging SpectroRadiometer's vertical-viewing (nadir) camera. Salt Lake City, situated near the southeastern shore of the Great Salt Lake, is host to the 2002 Winter Olympic Games, which open Friday, February 8. Venues for five of the scheduled events are at city (indoor) locations, and five in mountain (outdoor) facilities. All ten can be found within the area contained in these images. Some of the outdoor events take place at Ogden, situated north of Salt Lake City and at Park City, located to the east.

Salt Lake City is surrounded by mountains including the Wasatch Range to the east, and the temperature difference between the Great Salt Lake and the overlying atmosphere enhances the moisture content of winter storms. These factors, in combination with natural cloud seeding by salt crystals from the lake, are believed to result in greater snowfall in neighboring areas compared to more distant locales.

In addition to the obvious difference in snow cover between the winter and summer views, water color changes in parts of the Great Salt Lake are apparent in these images. The distinctly different coloration between the northern and southern arms of the Great Salt Lake is the result of a rock-filled causeway built in 1953 to support a permanent railroad. The causeway has resulted in decreased circulation between the two arms and higher salinity on the northern side. The southern part of the lake includes the large Antelope Island, and at full resolution a bridge connecting it to the mainland can be discerned.

These images are natural color views acquired on February 8, 2001 and June 16, 2001, during Terra orbits 6093 and 7957, respectively. Each image represents an area of about 220 kilometers x 285 kilometers.

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.

2002-01-01

183

Winter 1994 Weather and Ice Conditions for the Laurentian Great Lakes.  

NASA Astrophysics Data System (ADS)

The Laurentian Great Lakes developed their most extensive ice cover in over a decade during winter 1994 [December-February 1993/94 (DJF 94)]. Extensive midlake ice formation started the second half of January, about 2 weeks earlier than normal. Seasonal maximal ice extent occurred in early February, again about 2 weeks earlier than normal. Winter 1994 maximum (normal) ice coverages on the Great Lakes are Lake Superior 96% (75%), Lake Michigan 78% (45%), Lake Huron 95% (68%), Lake Erie 97% (90%), and Lake Ontario 67% (24%). Relative to the prior 31 winters (1963-93), the extent of seasonal maximal ice cover for winter 1994 for the Great Lakes taken as a unit is exceeded by only one other winter (1979); however, other winters for individual Great Lakes had similar maximal ice covers.Anomalously strong anticyclonic circulation over the central North Pacific (extending to the North Pole) and an abnormally strong polar vortex centered over northern Hudson Bay combined to produce a circulation pattern that brought frequent air masses of Arctic and polar origin to the eastern third of North America. New records were set for minimum temperatures on 19 January 1994 at many locations in the Great Lakes region. A winter severity index consisting of the average November-February air temperatures averaged over four sites on the perimeter of the Great Lakes (Duluth, Minnesota; Sault Ste. Marie, Michigan; Detroit, Michigan; and Buffalo, New York) indicates that winter 1994 was the 21st coldest since 1779. The unseasonably cold air temperatures produced much-above-normal ice cover over the Great Lakes and created problems for lake shipping. Numerous fatalities and injuries were attributed to the winter weather, which included several ice and snow storms. The much-below-normal air temperatures resulted in enhanced lake-effect snowfall along downwind lake shores, particularly during early to midwinter, prior to extensive ice formation in deeper lake areas. The low air temperatures were also responsible for record 1-day electrical usage and multimillion dollar costs associated with snow removal, U.S. and Canadian Coast Guard operational assistance to ships beset in ice, damage to ships by ice, damage to public and private property by river ice jams and associated flooding, frozen underground water pipes, and damage to fruit trees.

Assel, Raymond A.; Janowiak, John E.; Young, Sharolyn; Boyce, Daron

1996-01-01

184

Winter Storm Lesson Plan  

NSDL National Science Digital Library

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 ...

Tasia S.

2010-09-23

185

The Fabled Maine Winter  

NSDL National Science Digital Library

No study of Maine weather would be complete without analysis of the year of 1816 - the year with no summer in an area from western Pennsylvania and New York, up through Quebec and across to Maine and the Canadian maritimes. In this five-unit lesson, students will investigate the causes and effects of the Fabled Maine Winter by exploring a variety of data sources. They will locate, graph, and analyze meteorological and climatological data for Portland, Maine, for more recent years to try to find one that most closely resembles the fabled Maine winter of 1816.

186

Winter Storm (weather)  

NSDL National Science Digital Library

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 ...

Aubree Miller

2009-09-28

187

WINTERING OF LESSER GOLDEN-PLOVERS IN EASTERN NORTH AMERICA  

Microsoft Academic Search

Although said to winter entirely in southern South America, Lesser Golden- Plovers (Pluvialis dominica dominica) have been recorded in eastern North America in small numbers throughout the winter. A literature search indicates that records are regular through December, most of them probably of late fall migrants, and again increase in late February, probably of early spring migrants. There are at

DENNIS R. PAULSON; DAVID S. LEE

188

Winter Biological Processes Could Help Convert Arctic Tundra to Shrubland  

Microsoft Academic Search

In arctic Alaska, air temperatures have warmed 0.5 degrees Celsius (?C) per decade for the past 30 years, with most of the warming coming in winter. Over the same period, shrub abundance has increased, perhaps a harbinger of a conversion of tundra to shrubland. Evidence suggests that winter biological processes are contributing to this conversion through a positive feedback that

MATTHEW STURM; JOSH SCHIMEL; GARY MICHAELSON; JEFFREY M. WELKER; STEVEN F. OBERBAUER; GLEN E. LISTON; JACE FAHNESTOCK; VLADIMIR E. ROMANOVSKY

2005-01-01

189

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...

190

Phenological and ecological consequences of changes in winter snowpack in the Colorado Rocky Mountains  

NASA Astrophysics Data System (ADS)

The date the snowpack disappears in spring is an important seasonal event at high altitudes because it determines the beginning of the growing season, which in turn influences the phenology of plant growth and flowering, and thus the availability of these resources for animal consumers. At our study site at 2,900m in the Colorado Rocky Mountains, the Rocky Mountain Biological Laboratory, snowmelt now averages two weeks earlier than in 1975. Earlier snowmelt results from a combination of lower snowfall (38 cm less since 1975), dust storms (increasing in frequency, which reduces the snowpack albedo), and warmer spring temperatures (April minimum temperature has increased 3.1C since 1973; 2012 April mean temperature was 3.4C above the 38-year mean). There is also a trend of increasing annual precipitation falling as rain instead of snow. We have monitored flowering phenology and abundance for about 100 species of plants in permanent plots since 1973, and use this record to look at how the change in timing of snowmelt has affected flowering. There is significant variation among years in flowering phenology (e.g., about six weeks difference between 2011 and 2012), with a mid-season decline in flowering abundance becoming apparent as the growing season starts earlier. The date of the last hard frost has not been changing in concert with the earlier growing season, with the consequence that many species now have flower buds developed that are then damaged or killed by frost. In 2012, snowmelt date was 23 April, and frost events on 27 May (-11.7C) and 11 June (-5.6C) did significant damage to vegetation of some species and to flower buds of many species. For example, flower abundance of the aspen sunflower Helianthella quinquenervis was 0.002% of 2011's flowering. In the absence of seed production, the demography of some plant species is likely being affected. Some animal species are also being affected by the changes in length and temperature of winter. New species of mammals, birds, and insects have begun to reproduce and overwinter at our field site in the past decade, and hibernators have changed the phenology of emergence from hibernation. Marmots now put on much more fat before entering hibernation. Interactions among species such as pollination and seed predation have also been affected by the changes in snowpack and phenology. For example, although both migratory hummingbirds and their floral resources are changing phenology, they are not changing at the same rate, leading to mismatches in their historical synchrony; hummingbirds now arrive well after their earliest food plant has begun to flower. A similar loss of synchrony appears to be affecting bumble bees as they emerge from overwintering underground, and one of their earliest nectar sources. Seed predator flies and moths, and their parasitoids, are probably being affected by the absence of seeds from species sensitive to frost. Thus many aspects of high-altitude ecological communities are being affected by the ongoing changes in depth of winter snowpack and the timing of its melting.

Inouye, D. W.; McKinney, A. M.

2012-12-01

191

Deciduous Plant Twigs in Winter  

ERIC Educational Resources Information Center

Describing, via illustration and narrative, the winter twigs found in the U.S., this article presents a sophisticated discussion of: beech, white ash, aspen, sycamore, red oak, butternut, and other winter twigs. (JC)

Clark, Eloise

1977-01-01

192

Winter Weather Introduction  

E-print Network

equipment. Organize and implement CF-FO operational plans. Review all procedures with CF-FO Managers the labor and equipment hours. #12;Campus Facilities-Energy Management Clear the coal road and interiorWinter Weather Management #12;Introduction Campus Facilities Staff Other Campus Organizations

Taylor, Jerry

193

Announcement Cryptography { Winter 2001  

E-print Network

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

deYoung, Brad

194

Winter and Specialty Wheat  

Microsoft Academic Search

Wheat is the most widely grown crop in the world. Winter wheat is primarily common wheat (2n = 6x = 42) which has extensive germplasm resources that are used in breeding, often for disease and insect resistance. Though\\u000a wheat can be used as a forage crop and its grain for animal feed, the primary uses of common wheat are to

P. Baenziger; R. Graybosch; D. Van Sanford; W. Berzonsky

195

GRAND RIVER Winter 2014  

E-print Network

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

Thompson, Michael

196

PLCO News, Winter 2001  

Cancer.gov

PLCO News, Winter 2001 Cancer Information Service If you have a question about cancer, call and speak with a trained specialist at NCI's Cancer Information Service (CIS). The CIS operates a nationwide toll-free telephone hotline Monday-Friday, 9:00 a.m.

197

PLCO News, Winter 2001  

Cancer.gov

PLCO News, Winter 2001 Trial Update Enrollment goal: 148,000 Total enrollment (as of November 30, 2000): 152,139 Men enrolled: 75,565 Women enrolled: 76,574 Number of people enrolled at age: 55-59 49,944 60-64 47,058

198

WINTER 2014 Sustainability and  

E-print Network

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

Stephens, Graeme L.

199

Winter Here and Now.  

ERIC Educational Resources Information Center

This book contains a wide variety of winter-oriented ideas and activities that can be adapted to all elementary grade levels and can also be integrated into existing mathematics, science, social studies, and/or art programs. The activities aim to help students develop the skills of observation, appreciation, and problem solving as well as

Finlay, Joy

200

Winter Playscape Dreaming  

ERIC Educational Resources Information Center

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

Keeler, Rusty

2006-01-01

201

Physical Oceanography Winter 2013  

E-print Network

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

Thompson, Andrew

202

Measuring Transpiration to Regulate Winter Irrigation Rates  

SciTech Connect

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.

Samuelson, Lisa [Auburn University] [Auburn University

2006-11-08

203

The Winter Olympics--On Ice.  

ERIC Educational Resources Information Center

Describes several science activities designed around the upcoming Winter Olympics ice skating events which demonstrate the scientific principles behind the sport. Students learn that increasing the pressure on ice will lead to the ice melting, the principle involved in the spinning swing, and the technology of skates and skating outfits. (PVD)

Hoover, Barbara G.

1998-01-01

204

Lightning Protection against Winter Lightning  

Microsoft Academic Search

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

Hitoshi Sugimoto

2007-01-01

205

Winter Wilderness Travel and Camping.  

ERIC Educational Resources Information Center

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

Gilchrest, Norman

206

Improved antioxidative protection in winter swimmers.  

PubMed

Adaptation to oxidative stress is an improved ability to resist the damaging effects of reactive oxygen species, resulting from pre-exposure to a lower dose. Changes in uric acid and glutathione levels during ice-bathing suggest that the intensive voluntary short-term cold exposure of winter swimming produces oxidative stress. We investigated whether the repeated oxidative stress in winter swimmers results in improved antioxidative adaptation. We obtained venous blood samples from winter swimmers and determined important components of the antioxidative defense system in the erythrocytes or blood plasma: reduced and oxidized glutathione (GSH and GSSG), and the activities of superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (Cat). The control group consisted of healthy people who had never participated in winter swimming. The baseline concentration of GSH and the activities of erythrocytic SOD and Cat, were higher in winter swimmers. We interpret this as an adaptative response to repeated oxidative stress, and postulate it as a new basic molecular mechanism of increased tolerance to environmental stress. PMID:10396606

Siems, W G; Brenke, R; Sommerburg, O; Grune, T

1999-04-01

207

Wintering site interchange amongst Greenland White-fronted Geese Anser albifrons flavirostris captured at Wexford Slobs, Ireland  

Microsoft Academic Search

The maximum count of Greenland White-fronted Geese wintering at Wexford, south-east Ireland (where over a third of the population winters) increased from 7910 in 1984\\/85 to 9530 in 1989\\/90. Although the population tends to be highly site-loyal on the wintering grounds, 14% of 700 marked geese seen in two consecutive winters changed site. Counts elsewhere in the wintering range and

S. M. Warren; A. J. Walsh; O. J. Merne; H. J. Wilson; A. D. Fox

1992-01-01

208

Winter climate limits subantarctic low forest growth and establishment.  

PubMed

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

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

2014-01-01

209

Winter Climate Limits Subantarctic Low Forest Growth and Establishment  

PubMed Central

Campbell Island, an isolated island 600 km south of New Zealand mainland (52S, 169E) 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. 0.6C 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

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

2014-01-01

210

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

Microsoft Academic Search

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

Timo Saarinen; Robin Lundell; Helena strm; Heikki Hnninen

2011-01-01

211

Titan's Winter Polar Vortex  

NASA Technical Reports Server (NTRS)

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.

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

2008-01-01

212

Winter Storm Activity  

NSDL National Science Digital Library

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 ...

Mikel Barbieri

2012-02-13

213

Storm Winter Activity  

NSDL National Science Digital Library

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 ...

KateOlsen58

2009-09-28

214

Winter Storm Activity  

NSDL National Science Digital Library

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 ...

Xuan

2010-02-22

215

Winter Storm Activity  

NSDL National Science Digital Library

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 ...

Kirsten Butcher

2008-09-26

216

Al's Winter Storm Activity  

NSDL National Science Digital Library

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 ...

Al

2010-02-22

217

Winter Storm Activity  

NSDL National Science Digital Library

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 ...

FerraraTechClassroom

2012-02-06

218

Winter weather activity  

NSDL National Science Digital Library

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 ...

Whitney Frankovic

2009-09-28

219

Winter Storm Warning  

NSDL National Science Digital Library

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 ...

2009-09-28

220

winter storm applicator  

NSDL National Science Digital Library

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. What causes the wind to blow. 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 ...

cory jones

2009-09-28

221

Nutritional condition of Pacific Black Brant wintering at the extremes of their range  

USGS Publications Warehouse

Endogenous stores of energy allow birds to survive periods of severe weather and food shortage during winter. We documented changes in lipid, protein, moisture, and ash in body tissues of adult female Pacific Black Brant (Branta bernicla nigricans) and modeled the energetic costs of wintering. Birds were collected at the extremes of their winter range, in Alaska and Baja California, Mexico. Body lipids decreased over winter for birds in Alaska but increased for those in Baja California. Conversely, body protein increased over winter for Brant in Alaska and remained stable for birds in Baja California. Lipid stores likely fuel migration for Brant wintering in Baja California and ensure winter survival for those in Alaska. Increases in body protein may support earlier reproduction for Brant in Alaska. Predicted energy demands were similar between sites during late winter but avenues of expenditure were different. Birds in Baja California spent more energy on lipid synthesis while those in Alaska incurred higher thermoregulatory costs. Estimated daily intake rates of eelgrass were similar between sites in early winter; however, feeding time was more constrained in Alaska because of high tides and short photoperiods. Despite differences in energetic costs and foraging time, Brant wintering at both sites appeared to be in good condition. We suggest that wintering in Alaska may be more advantageous than long-distance migration if winter survival is similar between sites and constraints on foraging time do not impair body condition. ?? The Cooper Ornithological Society 2006.

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

2006-01-01

222

Researchers Probe Why Colds Are More Likely in Winter  

MedlinePLUS

... features on this page, please enable JavaScript. Researchers Probe Why Colds Are More Likely in Winter Animal ... to congregate indoors with other people in smaller spaces -- could put people at an increased risk, rather ...

223

Natural snowfall reveals large-scale flow structures in the wake of a 2.5-MW wind turbine.  

PubMed

To improve power production and structural reliability of wind turbines, there is a pressing need to understand how turbines interact with the atmospheric boundary layer. However, experimental techniques capable of quantifying or even qualitatively visualizing the large-scale turbulent flow structures around full-scale turbines do not exist today. Here we use snowflakes from a winter snowstorm as flow tracers to obtain velocity fields downwind of a 2.5-MW wind turbine in a sampling area of ~36 36?m(2). The spatial and temporal resolutions of the measurements are sufficiently high to quantify the evolution of blade-generated coherent motions, such as the tip and trailing sheet vortices, identify their instability mechanisms and correlate them with turbine operation, control and performance. Our experiment provides an unprecedented in situ characterization of flow structures around utility-scale turbines, and yields significant insights into the Reynolds number similarity issues presented in wind energy applications. PMID:24960397

Hong, Jiarong; Toloui, Mostafa; Chamorro, Leonardo P; Guala, Michele; Howard, Kevin; Riley, Sean; Tucker, James; Sotiropoulos, Fotis

2014-01-01

224

Winter thunderstorms in central Europe in the past and the present  

NASA Astrophysics Data System (ADS)

Thunderstorms in the territories of the Czech Republic and neighbouring countries are almost exclusively the only phenomena occurring in the warm season. In the cold half of the year, from October to March, an average incidence of thunderstorms is only 2%, with the least occurrence being recorded in January. Yet, winter thunderstorms are dangerous particularly for air traffic because during them, the cloud base is rapidly falling down and visibility is suddenly worsening due to heavy snowfall. Notwithstanding these facts, the issue of their occurrence in the central European space has been paid little attention so far. Long years of study into historical weather extremes in the territory of the Czech Republic revealed over 10 chronicle entries on the occurrence of winter thunderstorms in the period between November and February from the 16th to the beginning of the 20th centuries. The irregular phenomenon was even devoted three occasional prints in central Europe in the second half of the 16th century, two of which were issued in Germany. Fires caused by winter thunderstorms were no sporadic cases. The occurrence of thunderstorms in winter was apparently associated with the passage of pronounced cold fronts. This can be documented on cases from the end of December 1555 when heavy thunderstorms and consequent fires were recorded within a short period of time in Holland, Germany and in Czech lands. It is assumed that the situation in 1627 was similar when a winter thunderstorm was recorded in Prague and in Holeov, southeastern Moravia on 28 December. In February 1581, a thunderstorm in Prague became one of three unusual events publicized by the local occasional newspaper. The beginning of modern studies into winter thunderstorms dates back to the 1960s with the use of lightning flash counters and later also with the use of systems for large-scale lightning flash detection and localization. However, more comprehensive meteorological and climatological assessments of their occurrence are still missing. The authors of the paper aim at outlining possibilities of the incidence of winter thunderstorms in the present and at contributing with some answers to the question of the long-term fluctuation of their frequency.

Munzar, Jan; Franc, Marek

225

Impact of warm winters on microbial growth  

NASA Astrophysics Data System (ADS)

Growth of soil bacteria has an asymmetrical response to higher temperature with a gradual increase with increasing temperatures until an optimum after which a steep decline occurs. In laboratory studies it has been shown that by exposing a soil bacterial community to a temperature above the community's optimum temperature for two months, the bacterial community grows warm-adapted, and the optimum temperature of bacterial growth shifts towards higher temperatures. This result suggests a change in the intrinsic temperature dependence of bacterial growth, as temperature influenced the bacterial growth even though all other factors were kept constant. An intrinsic temperature dependence could be explained by either a change in the bacterial community composition, exchanging less tolerant bacteria towards more tolerant ones, or it could be due to adaptation within the bacteria present. No matter what the shift in temperature tolerance is due to, the shift could have ecosystem scale implications, as winters in northern Europe are getting warmer. To address the question of how microbes and plants are affected by warmer winters, a winter-warming experiment was established in a South Swedish grassland. Results suggest a positive response in microbial growth rate in plots where winter soil temperatures were around 6 C above ambient. Both bacterial and fungal growth (leucine incorporation, and acetate into ergosterol incorporation, respectively) appeared stimulated, and there are two candidate explanations for these results. Either (i) warming directly influence microbial communities by modulating their temperature adaptation, or (ii) warming indirectly affected the microbial communities via temperature induced changes in bacterial growth conditions. The first explanation is in accordance with what has been shown in laboratory conditions (explained above), where the differences in the intrinsic temperature relationships were examined. To test this explanation the temperature relationships of the bacterial community from winter-warmed plots and plots with ambient soil temperatures were compared. No change in optimum temperature for growth could be detected, indicating that the microbial community has not been warm-adapted. This fits with what was seen also in the laboratory experiment where no changes in temperature response occurred when exposing bacteria to temperatures below 10 C within two months. The increase in activity measured during winter should thereby be due to changes in environmental factors, which will be further investigated. One big difference between heated and control plots was that heated plots were snow free during the entire winter, while control plots were covered by a 10 cm snow cover. The plant community composition and flowering time also differed in the warmed and ambient plot.

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

2014-05-01

226

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

E-print Network

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

Maxwell, Bruce D.

227

Increased snow facilitates plant invasion in mixedgrass prairie.  

PubMed

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

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

2008-07-01

228

winter storm activity  

NSDL National Science Digital Library

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 ...

Miss Prested

2010-05-26

229

Big6 Winter Production  

NSDL National Science Digital Library

Goals: a. Students will be able to identify the four seasons. b. Students will be able to identify three animals (bear, goose, moose) and know their lifestyle patterns in congruence with the four seasons, especially Winter months. c. Students will develop an understanding of their environment. 2nd Grade Standard III: Students will develop an understanding of their environment Objective 2: Observe and describe weather Goal C: Describe how weather affects people and weather Lesson Objectives: a. Identify the seasons and represent each with pictures and songs. b. Observe and describe typical weather for each of ...

Mrs. Cook

2010-11-05

230

Ensemble Applications in Winter  

NSDL National Science Digital Library

This lesson provides an introduction to ensemble forecast systems using an operational case study of the Blizzard of 2013 in Southern Ontario. The module uses models available to forecasters in the Meteorological Service of Canada, including Canadian and U.S. global and regional ensembles. After briefly discussing the rationale for ensemble forecasting, the module presents small lessons on probabilistic ensemble products useful in winter weather forecasting, immediately followed by forecast applications to a southern Ontario case. The learner makes forecasts for the Ontario Storm Prediction Center area and, in the short range, for the Toronto metropolitan area. An additional section applies a probabilistic aviation product to forecasts for Toronto Pearson International Airport.

COMET

2014-04-22

231

of Washington WINTER QUARTER 1994  

E-print Network

University of Washington Bulletin WINTER QUARTER 1994 Student Telephone Assisted Registration..............................................................................................6 On-leave - GraduateStudents...............................................................10 Address ChangeTelephone Service....:..................................................7 Overload

Kaminsky, Werner

232

Large-Scale Changes of Soil Wetness Induced by an Increase in Atmospheric Carbon Dioxide.  

NASA Astrophysics Data System (ADS)

The change in soil wetness in response to an increase of atmospheric concentration of carbon dioxide is investigated by two versions of a climate model which consists of a general circulation model of the atmosphere and a static mixed layer ocean. In the first version of the model, the distribution of cloud cover is specified whereas it is computed in the second version incorporating the interaction among cloud cover, radiative transfer and the atmospheric circulation. The CO2-induced changes of climate and hydrology are evaluated based upon a comparison between two quasi-equilibrium climates of a model with a normal and an above normal concentration of atmospheric carbon dioxide.It is shown that, in response to a doubling (or quadrupling) of atmospheric carbon dioxide, soil moisture is reduced in summer over extensive midcontinental regions of both North America and Eurasia in middle and high latitudes. Based upon the budget analysis of heat and water, the physical mechanisms responsible for the CO2-induced changes of soil moisture are determined for the following four regions: northern Canada, northern Siberia, the Great Plains of North America and southern Europe. It is found that, over northern Canada and northern Siberia, the CO2-induced reduction of soil moisture in summer results from the earlier occurrence of the snowmelt season followed by a period of intense evaporation. Over the Great Plains of North America, the earlier termination of the snowmelt season also contributes to the reduction of soil moisture during the summer season. In addition, the rainy period of late spring ends earlier, thus enhancing the CO2-induced reduction of soil moisture in summer. In the model with variable cloud cover, the summer dryness over the Great Plains is enhanced further by a reduction of cloud amount and precipitation in the lower model atmosphere. This reduction of cloud amount increases the solar energy reaching the continental surface and the rate of potential evaporation. Both the decrease of precipitation and the increase of potential evaporation further reduce the soil moisture during early summer and help to maintain it at a low level throughout the summer. Over Southern Europe, the CO2-induced reduction of soil wetness occurs in a qualitatively similar manner, although the relative magnitude of the contribution from the change in snowmelt is smaller.During winter, soil moisture increases poleward of 30N in response to an increase of atmospheric carbon dioxide. Because of the CO2-induced warming, a greater fraction of the total precipitation occurs as rainfall rather than snowfall. The warmer atmosphere also causes the accumulated snow cover to melt during winter. Both processes act to increase the soil moisture in all four regions during the winter season. The increase of soil moisture is enhanced further in high latitudes due to the increase of precipitation resulting from the penetration of warm, moisture-rich air into higher latitudes.The CO2-induced warming of the lower model troposphere increases with increasing latitude. The present analysis suggests that the changes of soil wetness described in this investigation are controlled by the latitudinal profile of the warming and are very broad scale, mid-continental phenomena.

Manabe, S.; Wetherald, R. T.

1987-04-01

233

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

NASA Astrophysics Data System (ADS)

Studies on recent climate trends from the Himalayan range are limited, and even completely absent at high elevation. This contribution specifically explores the southern slopes of Mt. Everest (central Himalaya), analyzing the minimum, maximum, and mean temperature and precipitation time series reconstructed from seven stations located between 2660 and 5600m a.s.l. over the last twenty years (1994-2013). We complete this analysis with data from all the existing ground weather stations located on both sides of the mountain range (Koshi Basin) over the same period. Overall we observe that the main and more significant increase in temperature is concentrated outside of the monsoon period. At higher elevations minimum temperature (0.072 0.011 C a-1, p < 0.001) increased far more than maximum temperature (0.009 0.012 C a-1, p > 0.1), while mean temperature increased by 0.044 0.008 C a-1, p < 0.05. Moreover, we note a substantial precipitation weakening (9.3 1.8mm a-1, p < 0.01 during the monsoon season). The annual rate of decrease at higher elevation is similar to the one at lower altitudes on the southern side of the Koshi Basin, but here the drier conditions of this remote environment make the fractional loss much more consistent (47% during the monsoon period). This study contributes to change the perspective on which climatic driver (temperature vs. precipitation) led mainly the glacier responses in the last twenty years. The main implications are the following: (1) the negative mass balances of glaciers observed in this region can be more ascribed to less accumulation due to weaker precipitation than to an increase of melting processes. (2) The melting processes have only been favored during winter and spring months and close to the glaciers terminus. (3) A decreasing of the probability of snowfall has significantly interested only the glaciers ablation zones (10%, p < 0.05), but the magnitude of this phenomenon is decidedly lower than the observed decrease of precipitation. (4) The lesser accumulation could be the cause behind the observed lower glacier flow velocity and the current stagnation condition of tongues, which in turn could have trigged melting processes under the debris glacier coverage, leading to the formation of numerous supraglacial and proglacial lakes that have characterized the region in the last decades. Without demonstrating the causes that could have led to the climate change pattern observed at high elevation, we conclude by listing the recent literature on hypotheses that accord with our observations.

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

2014-12-01

234

Pocahontas and The Winter's Tale  

Microsoft Academic Search

This essay argues what is on the face of it a ludicrous claim: that Shakespeare's play The Winter's Tale can profitably be read in the light of the story of the Algonquian princess Pocahontas. The reason that this seems ludicrous is quite simply that The Winter's Tale was almost certainly written before Shakespeare can have heard of Pocahontas, and in

Lisa Hopkins

2005-01-01

235

Winter Adapted Games First-Years Wanted!!!  

E-print Network

Winter Adapted Games aka WAG First-Years Wanted!!! Be a part of WAG ... one of the best events. The Winter Adapted Games (WAG) is an all-day winter event organized by students in the School of Kinesiology

Abolmaesumi, Purang

236

Winter fuels report  

SciTech Connect

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.

Not Available

1995-02-17

237

Winter Clouds Over Mie  

NASA Technical Reports Server (NTRS)

12 March 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) red wide angle image shows late winter clouds over the 104 km (65 mi) diameter crater, Mie. Cellular clouds occur in the lower martian atmosphere, surrounding Mie Crater. Their cloudtops are at an altitude that is below the crater rim. Higher than the crater rim occurs a series of lee wave clouds, indicating air circulation moving from west/northwest (left) toward the east/southeast (right). Mie Crater is located in Utopia Planitia, not too far from the Viking 2 landing site, near 48.5 N, 220.4 W. Sunlight illuminates this January 2004 scene from the lower left.

2004-01-01

238

Winter fuels report  

SciTech Connect

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.

Not Available

1995-02-03

239

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

USGS Publications Warehouse

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.

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

2008-01-01

240

[Effects of irrigation time on the growth and water- and fertilizer use efficiencies of winter wheat].  

PubMed

A field experiment was conducted to study the effects of irrigation time before wintering (November 10th, November 25th, and December 10th) and in spring (March 5th, re-greening stage; and April 5th, jointing stage) on the growth, dry matter translocation, water use efficiency (WUE), and fertilizer use efficiency (FUE) of winter wheat after returning corn straw into soil. The irrigation time before wintering mainly affected the wheat population size before wintering and at jointing stage, whereas the irrigation time in spring mainly affected the spike number, grain yield, dry matter translocation, WUE, and FUE. The effects of irrigation time before wintering to the yield formation of winter wheat were closely related to the irrigation time in spring. When the irrigation time in spring was at re-greening stage, the earlier the irrigation time before wintering, the larger the spike number and the higher the grain yield; when the irrigation time in spring was at jointing stage, the delay of the irrigation time before wintering made the spike number and grain yield decreased after an initial increase, the kernel number per plant increased, while the 1000-kernel mass was less affected. The WUE, nutrition uptake, and FUE all decreased with the delay of the irrigation time before wintering, but increased with the delay of the irrigation time in spring. Therefore, under the conditions of returning corn straw into soil and sowing when the soil had enough moisture, to properly advance the irrigation time before wintering could make the soil more compacted, promote the tillering and increase the population size before winter, and in combining the increased irrigation at jointing stage, could control the invalid tillering in early spring, increase the spiking rate, obtain stable kernel mass, and thus, increase the WUE and FUE, realizing water-saving and high efficiency for winter wheat cultivation. PMID:23359935

Dang, Jian-You; Pei, Xue-Xia; Wang, Jiao-Ai; Zhang, Jing; Cao, Yong; Zhang, Ding-Yi

2012-10-01

241

Meso-scale modeling and radiative transfer simulations of a snowfall event over France at microwaves for passive and active modes and evaluation with satellite observations  

NASA Astrophysics Data System (ADS)

Microwave passive and active radiative transfer simulations are performed with the Atmospheric Radiative Transfer Simulator (ARTS) for a mid-latitude snowfall event, using outputs from the Meso-NH mesoscale cloud model. The results are compared to the corresponding microwave observations available from MHS and CloudSat. The spatial structures of the simulated and observed brightness temperatures show an overall agreement since the large-scale dynamical structure of the cloud system is reasonably well captured by Meso-NH. However, with the initial assumptions on the single scattering properties of snow, there is an obvious underestimation of the strong scattering observed in regions with large frozen hydrometeor quantities. A sensitivity analysis of both active and passive simulations to the microphysical parameterizations is conducted. Simultaneous analysis of passive and active calculations provides strong constraints on the assumptions made to simulate the observations. Good agreements are obtained with both MHS and CloudSat observations when the single scattering properties are calculated using the "soft sphere" parameterization from Liu (2004), along with the Meso-NH outputs. This is an important step toward building a robust dataset of simulated measurements to train a statistically-based retrieval scheme.

Galligani, V. S.; Prigent, C.; Defer, E.; Jimenez, C.; Eriksson, P.; Pinty, J.-P.; Chaboureau, J.-P.

2014-07-01

242

Winter fuels report  

SciTech Connect

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.

Not Available

1995-01-27

243

Winter fuels report  

SciTech Connect

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.

Not Available

1990-10-04

244

Winter fuels report  

SciTech Connect

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.

Not Available

1995-01-13

245

Winter fuels report  

SciTech Connect

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.

Not Available

1994-10-01

246

Temperature and Resource Availability May Interactively Affect Over-Wintering Success of Juvenile Fish in a  

E-print Network

/Aquatic Ecology, Lund University, Lund, Sweden Abstract The predicted global warming may affect freshwater systems, the projected increase of winter temperatures may have important effects on the over- winter biology of a range water temperatures have been increasing during the last decades, most likely due to global warming (e

247

PHYSICS 122 LABORATORY (Winter, 2014)  

E-print Network

- 1 - PHYSICS 122 LABORATORY (Winter, 2014) COURSE GOALS 1. Learn how Chiang 235 Physics chiang@physics.ucdavis.edu 402-7113 Tony Tyson 514 Physics tyson@physics.ucdavis.edu 752-3830 TEACHING ASSISTANTS: Joe Mitchell 512

Yoo, S. J. Ben

248

PHYSICS 122 LABORATORY (Winter, 2015)  

E-print Network

- 1 - PHYSICS 122 LABORATORY (Winter, 2015) COURSE GOALS 1. Learn how Tyson 514 Physics tyson@physics.ucdavis.edu 752-3830 Xiangdong Zhu 235 Physics zhu@physics.ucdavis.edu 402-7113 TEACHING ASSISTANTS: Andrew Bradshaw 518

Yoo, S. J. Ben

249

Effect of canopy removal on snowpack quantity and quality, Fraser experimental forest, Colorado  

NASA Astrophysics Data System (ADS)

Snowpack peak water equivalent (PWE), ion concentration, content, and spatial distribution of ion load data from spring 1987-1996 in a 1 ha clearcut and adjacent forested plots vegetated by mature Picea engelmannii and Abies lasiocarpa in the Fraser experimental forest (FEF), Colorado are presented. Our objectives were: (1) to see if a forest opening might redistribute snowfall, snowpack moisture, and snowpack chemical content, and (2) to examine the importance of canopy interception on snowpack quantity and chemistry. On an average, the canopy intercepted 36% of snowfall. Interception was correlated with snowfall amount, snowpack PWE beneath the canopy, and air temperature. Canopy removal increased snowpack PWE to >90% cumulative snowfall inputs. Snowpack K +, H +, and NH 4+ concentrations on the clearcut were lower and NO 3- higher than in the snowpack beneath the forested plots. Cumulative snowfall K + input was less than in the clearcut snowpack; H + inputs were greater in snowfall than in the snowpack of any plot; and inorganic N (NO 3- and NH 4+) inputs from snowfall to the clearcut were greater than to the forested plots. Processes accounting for the differences between snowfall inputs and snowpack ion content were leaching of organic debris in the snowpack, differential elution of the snowpack, and canopy retention. There were significant trends by year in snowpack ion content at PWE without similar trends in snowfall inputs. This finding coupled with snowpack ion elution bring into question the use of snowpack chemistry as an indicator of winter atmospheric inputs in short-term studies.

Stottlemyer, R.; Troendle, C. A.

2001-05-01

250

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

Winter Only Kelsey Bennett Fall and Winter Jade Aurat Winter Only Heidi Bentley Fall and Winter Jacob Allison Barry Winter Only Paul Bissonnette Fall and Winter Melanie Barry Winter Only Stephanie Blandford

Lotze, Heike K.

251

Winter in Hellas Basin  

NASA Technical Reports Server (NTRS)

[figure removed for brevity, see original site]

Right now on Mars it is winter in the southern hemisphere. This means that the usually cloudy Hellas Basin is relatively free from clouds. Even though there is little cloud cover, the atmosphere is still much thicker due to the deeper basin compared to elsewhere on Mars, making image details not as crisp as when viewed through thinner atmosphere. In the center of the image are several dark streaks which originate from the side of a higher standing butte. The dark material is likely being eroded from a single layer within the cliff face. Wind has moved some of the eroded dark material to form the streaks.

Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

2002-01-01

252

RETRACTED ARTICLE: Space and time distributions of major winter storms in the United States  

Microsoft Academic Search

Winter storms are a major weather problem in the United States and their losses have been rapidly increasing. A total of 202\\u000a catastrophic winter storms involving ice storms, blizzards, and snowstorms, each causing >$5million in damages, occurred\\u000a during 19492003, and their losses totaled $35.2billion (2003 dollars). Catastrophic winter storms occurred in most parts\\u000a of the contiguous United States, but were

2008-01-01

253

Modeling Winter Cereal Grain Canopies for Legume Intercrop Establishment  

Technology Transfer Automated Retrieval System (TEKTRAN)

As energy demands continue to increase and wheat (Triticum aestivum L.) prices remain high, more North Central U.S. corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] producers may convert some production acres to wheat. Including a winter cereal grain in the rotation increases the opportunity ...

254

Winter CO2 fluxes in a boreal forest  

USGS Publications Warehouse

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.

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

1997-01-01

255

Confounded winter and spring phenoclimatology on large herbivore ranges  

USGS Publications Warehouse

Annual variation in winter severity and growing season vegetation dynamics appear to influence the demography of temperate herbivores but parsing winter from spring effects requires independent metrics of environmental conditions specific to each season. We tested for independence in annual variation amongst four common metrics used to describe winter severity and early growing season vegetation dynamics across the entire spatial distribution of elk (Cervus elaphus) in Wyoming from 1989 to 2006. Winter conditions and early growing season dynamics were correlated in a specific way. Winters with snow cover that ended early tended to be followed by early, but slow, rises in the normalized difference vegetation index (NDVI), while long winters with extended periods of snow cover were often followed by late and rapid rises in NDVI. Across the 35 elk ranges, 0.486.8 % of the variation in the rate of increase in NDVIs in spring was explained by the date snow cover disappeared from SNOTEL stations. Because phenoclimatological metrics are correlated across seasons and shifting due to climate change, identifying environmental constraints on herbivore fitness, particularly migratory species, is more difficult than previously recognized.

Christianson, David; Klaver, Robert W.; Middleton, Arthur; Kauffman, Matthew

2013-01-01

256

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

USGS Publications Warehouse

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.

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

1988-01-01

257

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

USGS Publications Warehouse

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.

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

2009-01-01

258

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

NASA Astrophysics Data System (ADS)

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 Mnsterland 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.

von Wulffen, Anja

2014-05-01

259

The Impact of Winter Heating on Air Pollution in China  

PubMed Central

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 20042012. 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

Xiao, Qingyang; Ma, Zongwei; Li, Shenshen; Liu, Yang

2015-01-01

260

The impact of winter heating on air pollution in China.  

PubMed

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

Xiao, Qingyang; Ma, Zongwei; Li, Shenshen; Liu, Yang

2015-01-01

261

Winter climate change: a critical factor for temperate vegetation performance.  

PubMed

Winter ecological processes are important drivers of vegetation and ecosystem functioning in temperate ecosystems. There, winter conditions are subject to rapid climate change. The potential loss of a longer-lasting snow cover with implications to other plant-related climate parameters and overwintering strategies make the temperate zone particularly vulnerable to winter climate change. A formalized literature search in the ISI Web of Science shows that plant related research on the effects of winter climate change is generally underrepresented. Temperate regions in particular are rarely studied in this respect, although the few existing studies imply strong effects of winter climate change on species ranges, species compositions, phenology, or frost injury. The generally positive effect of warming on plant survival and production may be counteracted by effects such as an increased frost injury of roots and shoots, an increased insect pest risk, or a disrupted synchrony between plants and pollinators. Based on the literature study, gaps in current knowledge are discussed. Understanding the relative effects of interacting climate parameters, as well as a stronger consideration of shortterm events and variability of climatic conditions is urgent. With respect to plant response, it would be particularly worthwhile to account for hidden players such as pathogens, pollinators, herbivores, or fungal partners in mycorrhization. PMID:20715613

Kreyling, Juergen

2010-07-01

262

Physiological responses of Yellowstone bison to winter nutritional deprivation  

USGS Publications Warehouse

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.

DelGiudice, Glenn D.; Singer, Francis J.; Seal, Ulysses S.; Bowser, Gillian

1994-01-01

263

Winter Weather: Hypothermia  

MedlinePLUS

... to an unconscious person. After body temperature has increased, keep the person dry and wrapped in a warm blanket, including the head and neck. Get medical attention as soon as possible. A person with severe ...

264

Seasonal dependence of peroxy radical concentrations at a northern hemisphere marine boundary layer site during summer and winter: evidence for photochemical activity in winter  

NASA Astrophysics Data System (ADS)

Peroxy radicals (HO2+?RO2) were measured at the Weybourne Atmospheric Observatory (52 N, 1 E), Norfolk using a PEroxy Radical Chemical Amplifier (PERCA) during the winter and summer of 2002. The peroxy radical diurnal cycles showed a marked difference between the winter and summer campaigns with maximum concentrations of 12 pptv at midday in the summer and maximum concentrations as high as 30 pptv (10 min averages) in winter at night. The corresponding nighttime peroxy radical concentrations were not as high in summer (3 pptv). The peroxy radical concentration shows a distinct anti-correlation with increasing NOx during the daylight hours. At night, peroxy radicals increase with increasing NOx indicative of the role of NO3 chemistry. The average diurnal cycles for net ozone production, N(O3) show a large variability in ozone production, P(O3), and a large ozone loss, L(O3) in summer relative to winter. For a daylight average, net ozone production in summer than winter (1.510.5 ppbv h-1 and 1.110.47 ppbv h-1 respectively) but summer shows more variability of (meteorological) conditions than winter. The variability in NO concentration has a much larger effect on N(O3) than the peroxy radical concentrations. Photostationary state (PSS) calculations show an NO2 lifetime of 5 min in summer and 21 min in the winter, implying that steady-state NO-NO2 ratios are not always attained during the winter months. The results show an active peroxy radical chemistry at night and the ability of winter to make oxidant. The net effect of this with respect to production of ozone in winter is unclear owing to the breakdown in the photostationary state.

Fleming, Z. L.; Monks, P. S.; Rickard, A. R.; Bandy, B. J.; Brough, N.; Green, T. J.; Reeves, C. E.; Penkett, S. A.

2006-08-01

265

Estimation of economically optimum seed rates for winter wheat from series of trials  

E-print Network

Estimation of economically optimum seed rates for winter wheat from series of trials C. M. THEOBALD of recent trials for winter wheat (Triticum aestivum L.) have influenced farming practice in the UK early, wheat can compensate for reduced plant populations by increased tiller production. Results from

Theobald, Chris

266

REPRODUCTION OF MELOIDOGYNE INCOGNITA ON WINTER COVER CROPS USED IN COTTON PRODUCTION  

Technology Transfer Automated Retrieval System (TEKTRAN)

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 will depend on soil temperature and how good of a host the cover crop is for M. incognita. ...

267

Microbial Biomass and Activities in Soil Aggregates Affected by Winter Cover Crops  

Microsoft Academic Search

vegetable cropping systems (Burket et al., 1997); how- ever, it is unclear whether legumes or nonlegumes are Winter cover crops may increase soil organic matter (SOM) and the most suitable for this task. Leguminous winter cover improve soil structure in intensively managed summer vegetable crop- ping systems. Our study examined the influence of three cover crop crops have the potential

I. C. Mendes; A. K. Bandick; R. P. Dick; P. J. Bottomley

1999-01-01

268

Winter Cereal Cover Crop Removal Strategy Affects Spring Soil Nitrate Levels  

Microsoft Academic Search

The use of winter cereal cover crops in no-till row crop systems has increased in the North Central Corn Belt. Timing of the cover crop removal can be managed to improve nitrogen availability for subsequently grown crops. Growers utilizing cover crop systems have several alternatives regarding the removal strategy for the winter cereal cover crop prior to seeding rotational corn

M. R. Jewett; K. D. Thelen

2007-01-01

269

Oligosaccharina new systemic factor in the acquisition of freeze tolerance in winter plants  

Microsoft Academic Search

The acquisition of freeze tolerance in winter plants involves, among other cellular responses, activated catabolism of cell wall polysaccharides, thereby liberating oligosaccharides. One of these was identified as an oligosaccharin (physiologically active fragment) that most likely originates from hemicelluloses. Treatment of winter wheat seedlings with the oligosaccharin at 2C increased their freeze tolerance by ?30%. Results obtained to date suggest

Aleksey I Zabotin; Tatyana S Barisheva; Irina A Larskaya; Tatyana E Toroshina; Oksana V Trofimova; Michael G Hahn; Olga A Zabotina

2005-01-01

270

Wintering ecology of adult North American ospreys  

USGS Publications Warehouse

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

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

2014-01-01

271

Prepare Your Home for Winter Weather  

MedlinePLUS

... Matters What's New A - Z Index Disasters & Severe Weather Earthquakes Extreme Heat Floods Hurricanes Landslides Tornadoes Tsunamis ... Wildfires Winter Weather Prepare Your Home for Winter Weather Language: English Espaol (Spanish) Recommend on Facebook Tweet ...

272

Severe Weather 101: Winter Weather Basics  

MedlinePLUS

... main types of precipitation are snow, sleet or freezing rain. Why can winter storms be so dangerous? ... to make a winter storm. Cold air. Below freezing temperatures in the clouds and near the ground ...

273

Take Steps to Avoid Winter Falls  

MedlinePLUS

... features on this page, please enable JavaScript. Take Steps to Avoid Winter Falls Check the traction of ... of injuries during the winter, but there are steps you can take to help stay on your ...

274

36 CFR 2.19 - Winter activities.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Winter activities. 2.19 Section 2.19...PROTECTION, PUBLIC USE AND RECREATION 2.19 Winter activities. (a) Skiing, snowshoeing...abide by area designations or activity restrictions established...

2010-07-01

275

36 CFR 1002.19 - Winter activities.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Winter activities. 1002.19 Section 1002...PROTECTION, PUBLIC USE AND RECREATION 1002.19 Winter activities. (a) Skiing, snowshoeing...abide by area designations or activity restrictions established...

2010-07-01

276

36 CFR 2.19 - Winter activities.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Winter activities. 2.19 Section 2.19...PROTECTION, PUBLIC USE AND RECREATION 2.19 Winter activities. (a) Skiing, snowshoeing...abide by area designations or activity restrictions established...

2011-07-01

277

36 CFR 1002.19 - Winter activities.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Winter activities. 1002.19 Section 1002...PROTECTION, PUBLIC USE AND RECREATION 1002.19 Winter activities. (a) Skiing, snowshoeing...abide by area designations or activity restrictions established...

2011-07-01

278

43 CFR 423.37 - Winter activities.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 2014-10-01 false Winter activities. 423.37 Section...Rules of Conduct 423.37 Winter activities. (a) You...within 300 yards of dams, power plants, pumping plants, spillways, stilling...

2014-10-01

279

43 CFR 423.37 - Winter activities.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Winter activities. 423.37 Section...Rules of Conduct 423.37 Winter activities. (a) You...within 300 yards of dams, power plants, pumping plants, spillways, stilling...

2010-10-01

280

43 CFR 423.37 - Winter activities.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Winter activities. 423.37 Section...Rules of Conduct 423.37 Winter activities. (a) You...within 300 yards of dams, power plants, pumping plants, spillways, stilling...

2011-10-01

281

43 CFR 423.37 - Winter activities.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Winter activities. 423.37 Section...Rules of Conduct 423.37 Winter activities. (a) You...within 300 yards of dams, power plants, pumping plants, spillways, stilling...

2013-10-01

282

Exploring the severe winter haze in Beijing  

NASA Astrophysics Data System (ADS)

Extreme haze episodes repeatedly shrouded Beijing during the winter of 2012-2013, causing major environmental and health problems. To better understand these extreme events, we analyzed the hourly observation data of PM2.5 and its major chemical composition, with support of model simulations. Severe winter haze was shown to result from stable synoptic meteorological conditions over a large part of northeastern China, rather than from an abrupt increase in emissions. Build-up of secondary species, including organics, sulfate, nitrate, and ammonium, was the major driving force behind these polluted periods. The contribution of organic matter decreased with increasing pollution level while sulfate and nitrate contributions increased. Correspondingly, the ratio of secondary organic carbon to elemental carbon decreased and had a stable diurnal pattern during heavily polluted periods, indicating weakened photochemical activity due to the dimming effect of high loading of aerosol particles. Under such conditions, the strong increase in sulfate and nitrate contributions to PM2.5 was attributed to an elevated conversion ratio, reflecting more active heterogeneous reactions with gradually increasing relative humidity. Moreover, we found that high aerosol concentration was a regional phenomenon. The accumulation process of aerosol particles occurred successively from southeast cities to Beijing. The "apparent" sharp increase in PM2.5 concentration of up to several hundred ?g m-3 per hour recorded in Beijing represented rapid "recovery" from an "interruption" to the continuous pollution accumulation over the region, rather than purely local chemical production. This suggests that regional transport of pollutants played an important role during these severe pollution events.

Zheng, G. J.; Duan, F. K.; Ma, Y. L.; Cheng, Y.; Zheng, B.; Zhang, Q.; Huang, T.; Kimoto, T.; Chang, D.; Su, H.; Pschl, U.; Cheng, Y. F.; He, K. B.

2014-07-01

283

Department of History Winter 2013  

E-print Network

Department of History Winter 2013 HTST 541.2 ­ Topics in the History of Science: History of Madness & Psychiatry in the Western Context Tuesday 14:00 ­ 16:45 PM Social Sciences Building ­ SS 613 ­ 618 Campus perspectives and technologies, as they gave rise to conceptions of biological psychiatry and the neuroscience

Habib, Ayman

284

Defending the Axioms Winter 2009  

E-print Network

Defending the Axioms Winter 2009 This course is concerned with the question of how set theoretic axioms are properly defended, of what counts as a good reason to regard a given statement methodological matters -- which axioms and on what grounds? -- and metaphysical/epistemological matters -- what

Barrett, Jeffrey A.

285

Schedule of Classes Winter 2006  

E-print Network

, Associate Registrar, phone 310-206-4028 or e-mail clindstrom@registrar.ucla.edu. E. Lee Kinsey Teaching and additional seating was installed. Effective Winter Quarter, they will be renamed to honor E. Lee Kinsey Kinsey Science Teaching Pavilion. NOTE: In the online Schedule of Classes, the rooms are listed as KNSY

Grether, Gregory

286

Data Analysis II Winter 2009  

E-print Network

with categorical variables P 11-12 2/12 Trend analysis P 13 2/17 Missing Data and Nonorthogonal Designs K&W 14 21 Data Analysis II Psy 612 CRN 24631 Winter 2009 1000-1120 UH Chiles 125 Instructor: Robert Mauro graduate level data analysis sequence. This course is devoted to topics in multiple regression with special

Lockery, Shawn

287

Data Analysis II Winter 2011  

E-print Network

. Class notes available on Blackboard Other Useful Books: Analysis of Variance & Experimental Design Hays 11-12 1/20 Trend Analysis P 13 Complex Analysis of Variance 1/25 Representation of Experimental1 Data Analysis II Psy 612 CRN 25146 Winter 2011 1000-1120 TR Gerlinger 242 Instructor: Robert

Lockery, Shawn

288

Remembering Winter: Toward a Molecular  

E-print Network

in the movie version of "The Wizard of Oz" Like the scarecrow, plants do not have a brain, but plants have,imbibedbarleyseedcouldbeplacedout- doors in the late winter to acquire the ability to flower (as cited in 43). The term vernaliza- tion

Raines, Ronald T.

289

UNIVERSITY LIBRARY Winter Quarter 2014  

E-print Network

, April 29 · Enroll on the HR Learning Management System · Simple online skills survey in March March 4 University Library Town Hall 14 #12;Program Management · Program management not limited to library managersUC DAVIS UNIVERSITY LIBRARY TOWN HALL Winter Quarter 2014 March 4, 2014 UC Davis University Library

Ferrara, Katherine W.

290

Reducing winter injury in blackberries  

Technology Transfer Automated Retrieval System (TEKTRAN)

We evaluated the combination of primocane training and cane positioning techniques using a rotatable cross-arm (RCA) trellis system and covering plants in winter to protect buds and canes from freezing temperatures in Apache, Boysenberry, Siskiyou, and Triple Crown blackberry. After tying p...

291

ENERGETICS OF TWO WINTERING RAPTORS  

Microsoft Academic Search

We present a deterministic model for predicting daily energy expenditure of two raptors--femaie American Kestrels (Falco sparverius) and Whim-tailed Kites (Elanus leucurus)-- wintering in coastal northwestern California. Inputs to the model include body mass, air temper- ature, photoperiod, energy expenditure of flight, and relative portions of the daytime spent in flight and nonflight activities. A simplified version of the model

JAMES R. KOPLIN; MICHAEL W. COLLOPY; ALBERT R. BAMMANN; HOWARD LEVENSON

1980-01-01

292

Britannica Sporting Record: The Winter Games  

NSDL National Science Digital Library

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.

Encyclopaedia Britannica, Inc.

293

An assessment of the potential and impacts of winter water banking in the Sokh aquifer, Central Asia  

Microsoft Academic Search

The dynamics of artificial recharge of winter surface flows coupled with increased summer groundwater use for irrigation in\\u000a the Sokh aquifer (Central Asia) have been investigated. Water release patterns from the giant Toktogul reservoir have changed,\\u000a as priority is now given to hydropower generation in winter in Kyrgyzstan. Winter flows have increased and summer releases\\u000a have declined, but the Syr

Inna Gracheva; Akmal Karimov; Hugh Turral; F. Miryusupov

2009-01-01

294

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

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Winter Harbor Lobster Boat Race, Winter Harbor, ME. 100.109 Section...100.109 Winter Harbor Lobster Boat Race, Winter Harbor, ME. (a) Regulated...commander may delay, modify, or cancel the race as conditions or circumstances...

2010-07-01

295

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...

296

Size-Related, First Winter Mortality of Freshwater Fishes  

Microsoft Academic Search

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

Michael L. Toneys; Daniel W. Coble

1979-01-01

297

ORIGINAL PAPER Climatology of winter transition days for the contiguous  

E-print Network

as cold fronts and warm fronts during the winter season. Among the two less common subtypes, transition. The relative frequencies of wintertime warm and cold fronts have changed over the period 1951­2007. Relative cold front frequency has significantly increased in the Northeast and Midwest regions, and warm front

Sheridan, Scott

298

STOCKPILED FORAGE KOCHIA TO MAINTAIN BEEF COWS DURING WINTER  

Technology Transfer Automated Retrieval System (TEKTRAN)

Extending grazing into the fall and winter, as opposed to feeding of harvested forages, can increase the sustainability of cattle ranching in the western U.S. This study was conducted to determine the economic value of grazing stockpiled forage kochia (Kochia prostrata [L.] Scrad.) and crested whea...

299

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 ...

300

Water use in a winter camelina soybean double crop system  

Technology Transfer Automated Retrieval System (TEKTRAN)

Double-cropping winter camelina (Camelina sativa) followed by soybean (Glycine max) may increase land-use efficiency by producing food and biofuel in a single season and is a viable cropping system for the northern Corn Belt. However, regional success of double-cropping, especially under dryland con...

301

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

ERIC Educational Resources Information Center

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

Sheridan Coll. (Ontario).

302

Children's School December 2013 Winter Bird Feeding  

E-print Network

Children's School December 2013 Winter Bird Feeding As winter approaches and you have extra time for family activities, consider attracting wild birds to your best windows for observation by hanging bird feeders outside them. The food you provide helps birds that do not migrate south in the winter because

303

Varietal Trials Results Wheat, Hard Red Winter  

E-print Network

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

Thomas, David D.

304

Spring grazing winter cereals in Montana  

Technology Transfer Automated Retrieval System (TEKTRAN)

Winter wheat (Triticum aestivum L.) is widely utilized for winter pasture and grain production in the central and southern US plains. Under rainfed conditions in the northern Great Plains, winter wheat seldom achieves adequate fall biomass for grazing, and little is known about the impacts of grazi...

305

Winter Industry Tour Start: Corvallis, Oregon  

E-print Network

Winter Industry Tour 10 Start: Corvallis, Oregon The purpose of Winter Industry Tour is to provide. Where is the group planning on traveling to next year? Stay involved to "My favorite part of Winter Boardman, Oregon Underground Tours Pendleton, ORegon Beef Northwest Madison Farm Canola Plant Echo, Oregon

Tullos, Desiree

306

USF MAGAZINE | WINTER 200828 Oceans of Evidence  

E-print Network

USF MAGAZINE | WINTER 200828 Oceans of Evidence DOUGALLAN/GETTYIMAGES #12;USF MAGAZINE | WINTER of plant domestication and agriculture in some locations. Then, about 300 years ago, the "Little Ice Age in on global warming. BY RANDOLPH FILLMORE C #12;USF MAGAZINE | WINTER 200830 For decades, measuring

Meyers, Steven D.

307

The Winter Environment. Environmental Education Curriculum.  

ERIC Educational Resources Information Center

Winter seems to hold more mysteries than any other season. It changes the behavior of wildlife and also brings about drastic changes in plant life. This unit, designed around the following two ideas: (1) to develop an appreciation and understanding of the winter season and (2) to understand how plants and wildlife are affected by the winter

Topeka Public Schools, KS.

308

Winter cover crops influence Amaranthus palmeri establishment  

Technology Transfer Automated Retrieval System (TEKTRAN)

Winter cover crops were evaluated for their effect on Palmer amaranth (PA) suppression in cotton production. Cover crops examined included rye and four winter legumes: narrow-leaf lupine, crimson clover, Austrian winter pea, and cahaba vetch. Each legume was evaluated alone and in a mixture with rye...

309

Daily movements of female mallards wintering in Southwestern Louisiana  

USGS Publications Warehouse

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.

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

2011-01-01

310

Winter fuels report. Week ending, October 21, 1994  

SciTech Connect

Demand for distillate fuel oil is expected to show a slight decline this winter (October 1, 1994-March 31, 1995) from last, according to the Energy Information Administration`s (EIA) 4th Quarter 1994 Short-Term Energy Outlook (STEO) Mid-World Oil Price Case forecast. EIA projects winter demand to decline one percent to 3.3 million barrels per day, assuming normal weather conditions. The effects of expected moderate growth in the economy and industrial production will likely be offset by much warmer temperatures than those a year ago. EIA projects prices for both residential heating oil and diesel fuel to be moderately higher than prices last winter. Increases are likely, primarily because crude oil prices are expected to be higher than they were a year earlier (Table FE5).

Zitomer, M.; Griffith, A.; Zyren, J.

1994-10-01

311

Night eating syndrome and winter seasonal affective disorder.  

PubMed

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 (DSM-IV criteria). Depression was assessed with the 29 item-HDRS and Sigh-SAD version and with the 7-item depression subscale of the Hospital Anxiety and Depression scale. The prevalence of NES was low (4.8%). Patients suffering from NES were significantly older with a greater duration of the illness. NES was not related to depression and to Body Mass Index. NES and winter SAD are not overlapping disorders. PMID:16632073

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

2006-07-01

312

Winter planning. Quantity surveying.  

PubMed

During Christmas and new year 1999-2000 there will be eight bank holiday or weekend days. Emergency admissions are likely to be high during this period. A mathematical model can be used to calculate how many beds will need to be empty on Christmas day in order to cope with an increase in emergency admissions afterwards. In this study of a 781-bed acute hospital, a minimum of 209 beds--equivalent to seven wards--will need to be empty on Christmas day. This model is derived from information on the patient administration system and could be used by all hospitals to plan care. PMID:10621327

Davison, A; Bowhay, S

1999-09-30

313

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

USGS Publications Warehouse

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.

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

2007-01-01

314

Seasonal dependence of peroxy radical concentrations at a Northern hemisphere marine boundary layer site during summer and winter: evidence for radical activity in winter  

NASA Astrophysics Data System (ADS)

Peroxy radicals (HO2+? RO2) were measured at the Weybourne Atmospheric Observatory (52 N, 1 E), Norfolk using a PEroxy Radical Chemical Amplifier (PERCA) during the winter and summer of 2002. The peroxy radical diurnal cycles showed a marked difference between the winter and summer campaigns with maximum concentrations of 12 pptv at midday in the summer and maximum concentrations as high as 30 pptv (10 min averages) in winter at night. The corresponding nighttime peroxy radical concentrations were not as high in summer (3 pptv). The peroxy radical concentration shows a distinct anti-correlation with increasing NOx during the daylight hours. At night, peroxy radicals increase with increasing NOx indicative of the role of NO3 chemistry. The average diurnal cycles for net ozone production, N(O3) show a large variability in ozone production, P(O3), and a large ozone loss, L(O3) in summer relative to winter. For a daylight average, net ozone production in summer was higher than winter (1.510.5 ppbv h-1 and 1.110.47 ppbv h-1, respectively). The variability in NO concentration has a much larger effect on N(O3) than the peroxy radical concentrations. Photostationary state (PSS) calculations show an NO2 lifetime of 5 min in summer and 21 minutes in the winter, implying that steady-state NO-NO2 ratios are not always attained during the winter months. The results show an active peroxy radical chemistry at night and that significant oxidant levels are sustained in winter. The net effect of this with respect to production of ozone in winter is unclear owing to the breakdown in the photostationary state.

Fleming, Z. L.; Monks, P. S.; Rickard, A. R.; Bandy, B. J.; Brough, N.; Green, T. J.; Reeves, C. E.; Penkett, S. A.

2006-12-01

315

Writing TAFS for Winter Weather  

NSDL National Science Digital Library

"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 airports 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.

2014-09-14

316

Community Ordination Utilizing Winter Stoneflies  

NSDL National Science Digital Library

This resource is a manual for instructing a field exercise in ecology, in which students sample winter stonefly communities to explore community structure and dynamics, and to gain experience with the techniques of ordination. This exercise is suitable for general ecology, community ecology, or invertebrate biology courses. The field methodologies could be supplemented by more current ordination techniques, such as computer programs which reduce the protracted calculations and allow more in depth exploration of different ordination techniques.

Vinnedge M. Lawrence (Washington and Jefferson College; )

1988-01-01

317

Nuclear Winter PowerPoint  

NSDL National Science Digital Library

This one-hour slide presentation on the theory of nuclear winter discusses the potentially catastrophic effects that large-scale nuclear warfare might have on Earth's atmosphere and climate. Topics include the nature of the world's current nuclear arsenal, climate model results, phenomena that might produce analogous impacts (forest fires, city fires, volcanic eruptions, extinction of the dinosaurs), impacts on humans, and policy implications.

Alan Robock

2005-07-04

318

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

PubMed Central

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

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

2013-01-01

319

Winter Biological Processes Could Help Convert Arctic Tundra to Shrubland  

NSDL National Science Digital Library

This peer-reviewed article from BioScience investigates the change from tundra to shrubland in the arctic. In arctic Alaska, air temperatures have warmed 0.5 degrees Celsius (C) per decade for the past 30 years, with most of the warming coming in winter. Over the same period, shrub abundance has increased, perhaps a harbinger of a conversion of tundra to shrubland. Evidence suggests that winter biological processes are contributing to this conversion through a positive feedback that involves the snow-holding capacity of shrubs, the insulating properties of snow, a soil layer that has a high water content because it overlies nearly impermeable permafrost, and hardy microbes that can maintain metabolic activity at temperatures of ?6C or lower. Increasing shrub abundance leads to deeper snow, which promotes higher winter soil temperatures, greater microbial activity, and more plant-available nitrogen. High levels of soil nitrogen favor shrub growth the following summer. With climate models predicting continued warming, large areas of tundra could become converted to shrubland, with winter processes like those described here possibly playing a critical role.

MATTHEW STURM, JOSH SCHIMEL, GARY MICHAELSON, JEFFREY M. WELKER, STEVEN F. OBERBAUER, GLEN E. LISTON, JACE FAHNESTOCK, and VLADIMIR E. ROMANOVSKY (; )

2005-01-01

320

What do we know about winter active ground beetles (Coleoptera, Carabidae) in Central and Northern Europe?  

PubMed

This paper summarizes the current knowledge on winter active Carabidae in Central and Northern Europe. In total 73 winter active species are listed, based on literature and own observations. Ground beetles are among the three most numerous Coleoptera families active during the autumn to spring period. The winter community of Carabidae is composed both of larvae (mainly autumn breeding species) and adults, as well as of epigeic species and those inhabiting tree trunks. Supranivean fauna is characterized by lower species diversity than the subnivean fauna. The activity of ground beetles decreases in late autumn, is lowest during mid-winter and increases in early spring. Carabidae are noted as an important food source in the diet of insectivorous mammals. They are also predators, hunting small winter active invertebrates. PMID:21738431

Jasku?a, Radomir; Soszy?ska-Maj, Agnieszka

2011-01-01

321

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

PubMed Central

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

Schrder, Arne

2013-01-01

322

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

PubMed

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

Princ, Karine; Zuckerberg, Benjamin

2015-02-01

323

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

NASA Astrophysics Data System (ADS)

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.

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

2013-11-01

324

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

USGS Publications Warehouse

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 19912000. 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 4.610.1 kg ha?1with winter cover crops resulting in a reduction rate of 2767% 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?1when 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.

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

2013-01-01

325

Communicating Certainty About Nuclear Winter  

NASA Astrophysics Data System (ADS)

I have been spending much of my time in the past several years trying to warn the world about the continuing danger of nuclear weapons, and that the solution is a rapid reduction in the nuclear arsenal. I feel that a scientist who discovers dangers to society has an ethical duty to issue a warning, even if the danger is so scary that it is hard for people to deal with. The debate about nuclear winter in the 1980s helped to end the nuclear arms race, but the planet still has enough nuclear weapons, even after reductions planned for 2017 under the New START treaty, to produce nuclear winter, with temperatures plunging below freezing in the summer in major agricultural regions, threatening the food supply for most of the planet. New research by myself, Brian Toon, Mike Mills, and colleagues over the past six years has found that a nuclear war between any two countries, such as India and Pakistan, using 50 atom bombs each of the size dropped on Hiroshima could produce climate change unprecedented in recorded human history, and a world food crisis because of the agricultural effects. This is much less than 1% of the current global arsenal. Communicating certainty - what we know for sure - has been much more effective than communicating uncertainty. The limited success I have had has come from persistence and serendipity. The first step was to do the science. We have published peer-reviewed articles in major journals, including Science, Nature, Proceedings of the National Academy of Sciences, Journal of Geophysical Research, Atmospheric Chemistry and Physics, Physics Today, and Climatic Change. But policymakers do not read these journals. Through fairly convoluted circumstances, which will be described in this talk, we were able to get papers published in Scientific American and the Bulletin of Atomic Scientists. I have also published several encyclopedia articles on the subject. As a Lead Author of Chapter 8 (Radiative Forcing) of the recently published Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), I inserted a paragraph pointing out that volcanic eruptions serve as an analog that supports new work on nuclear winter. This is the first time that nuclear winter has been in the IPCC report. I will tell the story of the discussions within our chapter, with review editors, and with the IPCC leadership that resulted in a box in Chapter 8 that discusses nuclear winter. We gave a briefing to John Holdren, the President's Science Advisor, about the work. Daniel Ellsberg, Fidel Castro, and Mikhail Gorbachev found out about our work, and used the results to appeal for nuclear abolition. In 2013 the work was featured at the Conference on the Humanitarian Impact of Nuclear Weapons in Oslo, Norway attended by 132 nations, and I gave a TEDx talk, I published an opinion piece on the CNN website, and I gave an invited public lecture in Nagasaki, Japan, all about the climatic consequences of nuclear war. I am now using Twitter and Facebook to communicate about nuclear winter. The threat that nuclear weapons pose to the planet is a much easier problem to solve than global warming. We need to eliminate nuclear weapons so we have the luxury of working on the global warming problem without the possibility of the existential global threat still posed by the global nuclear arsenal.

Robock, A.

2013-12-01

326

Comparison of generalist predators in winter-flooded and conventionally managed rice paddies and identification of their limiting factors.  

PubMed

Winter-flooding of rice paddies without the application of agricultural chemicals is attracting attention as a new agricultural method for enhancing the habitat conditions of wintering waterfowl in rice paddy ecosystems throughout Japan and east Asia. Conditions in these paddies are expected to result in restoration of not only the winter habitats of waterfowl but also those of other taxonomic groups during the rice growing season. In this study, we tested whether the diversity of summer spiders--ubiquitous predators in rice paddies--was higher in the winter-flooded paddies than in the conventional ones by conducting field measurements in 31 winter-flooded and 7 conventional paddies. Limiting factors of spiders in the winter-flooded paddies were then examined. Results revealed that both the density and species richness of spiders were significantly higher in the winter-flooded paddies than in the conventional ones both before and after the insecticide application against pecky rice bug Stenotus rubrovittatus (Matsumura)(Hemiptera: Miridae) to conventional paddies. In addition, spider density and species richness in the winter-flooded paddies correlated with the availability of two prey groups--chironomids and other nematocera. These findings suggest that in the winter-flooded paddies the diversity of generalist predators is higher than in the conventional ones during the rice-growing season and that the combination of management at both the landscape and field level is likely more effective for increasing spider abundance in winter-flooded paddies. PMID:25140294

Takada, Mayura B; Takagi, Shun; Iwabuchi, Shigeki; Mineta, Takuya; Washitani, Izumi

2014-01-01

327

Condensation during Titan's Polar Winter  

NASA Astrophysics Data System (ADS)

Titan is currently experiencing winter in its northern hemisphere and the lower atmosphere of its north polar region has been in prolonged darkness since the solstice in October 2002. As a result, the north polar region is currently characterised by cold stratospheric temperatures and there is enrichment of trace gases due to downward atmospheric motion (e.g. Teanby et al., Icarus 181 pp. 243-255, 2006). These conditions make the polar winter very suitable for cloud formation in the stratosphere. A simple transport and condensation model has been made to explore condensation processes in Titan's northern stratosphere. In the model, the atmosphere is advected downwards and clouds are formed as the saturation pressure of various gases is reached. Upper limits of the gases C4N2 and propionitrile (C2H5CN) were determined from Cassini Composite Infrared Spectrometer data to assess scenarios of chemical disequilibrium where the gas phase is far less abundant than the solid phase. The upper limit for C4N2 is 9e-9, which discounts the massive C4N2 build-up in the polar winter proposed by Samuelson et al. (PSS 45, pp. 941-948, 1997) to explain the observed C4N2 cloud at the Voyager epoch. The propionitrile upper limit is 8e-9, which is several orders of magnitude less than needed to create the condensate feature at 220 cm-1 of Khanna (Icarus 177, pp. 116-121) and de Kok et al. (Icarus, in press), assuming it is propionitrile ice, under the steady-state conditions explored by the aformentioned model. HCN ice seems to play an important role in the formation of a massive polar cloud (Haze B in de Kok et al., Icarus, in press), because of the unavailability of sufficient condensable gas other than HCN (and possibly HC3N) to produce the condensate features seen in far-infrared spectra at 220 cm-1.

de Kok, Remco; Irwin, P. G.; Teanby, N. A.; Fletcher, L. N.; Howett, C. J.; Calcutt, S. B.; Bowles, N. E.; Taylor, F. W.

2007-10-01

328

Winter Precipitation in Southeast China: Interdecadal and Interannual variability  

NASA Astrophysics Data System (ADS)

Interdecadal variability of observed winter (DJF) precipitation in Southeast China (1961 to 2010) is characterized by the first EOF of the three-monthly Standardized Precipitation Index (SPI) subjected to a 9-year running mean, while the differences from the original describe the interannual fluctuations. For both time scales the dominating spatial modes represent similar features involving the East Asian Winter Monsoon (EAWM) and the Arctic Oscillation (AO). Dynamic composite analysis (based on NCEP/NCAR and ERA-40 reanalyses) reveals the following results: (i) Interdecadal SPI-variations show a nonlinear trend from a dryer state in the 1970s via an increase during the 1980s towards stabilization on wetter conditions commencing with the 1990s. The associated large-scale circulation features are derived from composites of the wetter (1988-2002) and dryer (1962-1976) period. Increasing wetness in Southeast China is attributed to a weakened East Asian Winter Monsoon (EAWM) which, due to weaker northerlies along the east coast of China, favors northward transport of warm and humid air from tropical oceans to South China. After the 1980s the reduced EAWM, in turn, is related to low-level warming over high-latitude Eurasia due to stronger Arctic Oscillation (AO) by warmer zonal temperature advection. This demonstrates the role of AO in determining the nonlinear trend observed in winter precipitation over South China. (ii) Interannual variability of winter precipitation in Southeast China is related to EAWM modulated by the East Asian Trough (EAT); a weaker (stronger) EAT than normal will weaken (strengthen) EAWM, leading to abundant (less) precipitation in Southeast China.

Zhang, ling; Zhu, xiuhua; Fraedrich, Klaus; Zhi, xiefei

2013-04-01

329

Winter warming from large volcanic eruptions  

NASA Technical Reports Server (NTRS)

An examination of the Northern Hemisphere winter surface temperature patterns after the 12 largest volcanic eruptions from 1883-1992 shows warming over Eurasia and North America and cooling over the Middle East which are significant at the 95 percent level. This pattern is found in the first winter after tropical eruptions, in the first or second winter after midlatitude eruptions, and in the second winter after high latitude eruptions. The effects are independent of the hemisphere of the volcanoes. An enhanced zonal wind driven by heating of the tropical stratosphere by the volcanic aerosols is responsible for the regions of warming, while the cooling is caused by blocking of incoming sunlight.

Robock, Alan; Mao, Jianping

1992-01-01

330

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

PubMed

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

Winder, V L; Emslie, S D

2011-01-01

331

Impacts of winter storms on air-sea gas exchange  

NASA Astrophysics Data System (ADS)

The objective of this study is to investigate air-sea gas exchange during winter storms, using field measurements from Ocean Station Papa in the Northeast Pacific (50N, 145W). We show that increasing gas transfer rates are coincident with increasing winds and deepening depth of bubble penetration, and that this process depends on sea state. Wave-breaking is shown to be an important factor in the gas transfer velocity during the peaks of the storms, increasing the flux rates by up to 20%. Gas transfer rates and concentrations can exhibit asymmetry, reflecting a sudden increase with the onset of a storm, and gradual recovery stages.

Zhang, Weiqing; Perrie, Will; Vagle, Svein

2006-07-01

332

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

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

Queitsch, Christine

333

Development of a Model System to Identify Differences in Spring and Winter Oat  

PubMed Central

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

Chawade, Aakash; Lindn, Pernilla; Brutigam, Marcus; Jonsson, Rickard; Jonsson, Anders; Moritz, Thomas; Olsson, Olof

2012-01-01

334

Nuclear winter or nuclear fall?  

NASA Astrophysics Data System (ADS)

Climate is universal. If a major modern nuclear war (i.e., with a large number of small-yield weapons) were to happen, it is not even necessary to have a specific part of the world directly involved for there to be cause to worry about the consequences for its inhabitants and their future. Indeed, smoke from fires ignited by the nuclear explosions would be transported by winds all over the world, causing dark and cold. According to the first study, by Turco et al. [1983], air surface temperature over continental areas of the northern mid-latitudes (assumed to be the nuclear war theatre) would fall to winter levels even in summer (hence the term nuclear winter) and induce drastic climatic conditions for several months at least. The devastating effects of a nuclear war would thus last much longer than was assumed initially. Discussing to what extent these estimations of long-term impacts on climate are reliable is the purpose of this article.

Berger, Andr

335

TRUE WINTER RANGE OF THE VEERY (CATHARUS FUSCESCENS): LESSONS FOR DETERMINING WINTER RANGES OF SPECIES THAT WINTER IN THE TROPICS  

Microsoft Academic Search

Most recent references describe the winter range of the Veery (Catharus fus- cescens) as including an extensive area from northern Colombia, Venezuela, and Guyana south to south-central Brazil. Analysis of seasonal distribution of specimen records in South America, however, shows that 91 of 105 specimens were taken during spring and fall, not winter; the remaining 14, taken from 2 December

J. V. Remsen Jr.

2001-01-01

336

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

Microsoft Academic Search

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 Skne, the southernmost province in Sweden. In 1992, soils and winter

Jan. E. Eriksson; Mats Sderstrm

1996-01-01

337

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...

338

Temperature and Resource Availability May Interactively Affect OverWintering Success of Juvenile Fish in a Changing Climate  

Microsoft Academic Search

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,

Jakob Brodersen; Jos Luis Rodriguez-Gil; Mikael Jnsson; Lars-Anders Hansson; Christer Brnmark; P. Anders Nilsson; Alice Nicolle; Olof Berglund; Mary O'Connor

2011-01-01

339

An adaptable urban house designed for the southern Brazilian climate - emphasis on summer and winter thermal comfort  

Microsoft Academic Search

SUMMARY The climate in southern Brazil is characterised by mild winters and hot-humid summers which requires the design to be adaptable to the often conflicting summer and winter requirements. In the residential sector, air conditioning consumption is still low, but it has been growing significantly along with an increase in people's purchasing power which emphasizes the importance of encouraging a

Marianne Costella

340

Social status does not affect resting metabolic rate in wintering dark-eyed junco (Junco hyemalis).  

PubMed

Studies of wintering birds have demonstrated a correlation between social rank and energy expenditures. It is assumed that dominance is energetically costly because of increased activity, possibly caused by elevated androgen levels. As winter acclimatization leads to an increase in metabolic rate, maintaining dominance status in a cold climate can be a substantial challenge. We measured resting metabolic rates in dominant and subordinate dark-eyed juncos (Junco hyemalis) living in small groups in a controlled winter environment. We found no significant effect of social rank when controlling for body size. It has been shown previously that high testosterone levels during the nonbreeding season can lead to higher body conductance, fat loss, and higher nocturnal body temperature. A hypothesis explaining our result is that for juncos it is preferable to maintain low androgen levels during winter and to maintain social rank using a mechanism other than higher agonistic activity. PMID:10801401

Vzina, F; Thomas, D W

2000-01-01

341

Dynamic interactions of snow and plants in the boreal forest, winter 2011-2012 revealed by time-lapse photography and LiDAR  

NASA Astrophysics Data System (ADS)

The winter blanket of snow in the boreal forest is anything but still. In winter 2011-2012 we followed the evolution of a snowpack on a boreal forest plot (0.5 ha) from first snowfall to the beginning of the melt in springtime. We used multiple methods such as time-lapse ground-based LiDAR (Light Detection and Ranging), time-lapse photography, imagery from a suspended cableway, snow-depth sensors, and frequent manual snow-pits. The experimental site is located near Fairbanks, Alaska, a typical boreal forest underlain by permafrost with sparse black spruce, larch, willow, and dwarf birch. We observed snowpack properties to be greatly affected by the vegetation substrate. Interactions between snow and plants are mainly dependent on falling snow properties (rate, wetness), plant heights and stiffness, plant canopy structure (leaves, number of branches, density), succession of weather events (wind before or after snow, thaw events) and pre-existing snow depth. Time-lapse imagery shows interception of snow by trees and shrubs controlled by air-temperature and wind events. LiDAR and snow pit measurements show one class of flexible shrubs (i.e. dwarf birch) bending under load, while a second class (willows) were far stiffer and resisted bending. Where dwarf birch branches were dense, it prevented snow from reaching the ground, leaving a significant air space under the snowpack. This vertical air gap can be as high as 10% of the total snow depth by the end of winter. Improving our understanding of the dynamic relationships between plants and snow is a fundamental key for studying boreal snow physics and snow ecology.

Filhol, S. V.; Sturm, M.

2012-12-01

342

Changing number of Canada geese wintering in different regions of the Atlantic Flyway  

USGS Publications Warehouse

During the past 40 years, profound changes have occurred in the number of Canada geese (Branta canadensis) wintering in different regions of the Atlantic Flyway. To explain the declining number of wintering geese in the Chesapeake and Carolina regions and the increasing number in the mid-Atlantic region from 1984 to 1989, I tested several hypotheses concerning regional differences in production, survival, and movement. The observation of migratory geese neckbanded in northern Quebec and throughout the winter grounds, and the lack of a regional difference in the proportion of young in the harvest, indicated that regional differences in production on the breeding grounds was unlikely to explain the observed changes in mid-winter number. Average annual survival rates were highest for geese in the Chesapeake and lowest for geese in the mid-Atlantic indicating that differential survival between regions did not cause the large changes in mid-winter numbers between regions. Geese were more likely to move to, and remain in, the Chesapeake than any other region. Estimated movement patterns did not match observed changes in mid-winter counts. Consequently, the observed changes in number of wintering geese from 1984 to 1989 could not be explained by my analyses of differential production, survival, or movement. The survival and movement analyses, however, were based largely on data from migratory, northern breeding geese. In the aerial Midwinter Waterfowl Survey, migratory, northern-breeding geese cannot be distinguished from local, southern-breeding geese. The changes in mid-winter numbers may result from declining numbers of migratory, northern-breeding geese wintering in the Chesapeake and Carolinas and increasing numbers of local, southem-breeding geese remaining in the mid-Atlantic.

Hestbeck, J.B.

1998-01-01

343

Evidence of a change in water chemistry in Canada's subarctic associated with enhanced winter streamflow  

NASA Astrophysics Data System (ADS)

winter streamflow is a characteristic of a nival/pluvial regime that has emerged in parts of the subarctic Canadian Shield because of increasingly common late summer rains. This phenomenon is part of a widespread trend toward higher winter streamflow in watersheds across the circumpolar north. There may be implications for biogeochemical systems as streamflow regimes undergo these types of changes associated with climate warming. Streamflow and geochemical fluxes were observed over 2 years with different winter flow conditions in a subarctic Canadian Shield catchment. Results show that higher wintertime loads of carbon and solutes associated with enhanced winter streamflow were in association with an expansion of contributing areas to run off over what would have existed during typical winter recession. Furthermore, the wet fall conditions that lead to enhanced winter streamflow require water tables close to the topographic surface in highly conductive organic soil layers, which is a similar to the condition during the spring melt. Fall rainfall-runoff leaves an ample volume of water in the lakes that are ubiquitous in this landscape. This water maintains winter streamflow during a time when it traditionally would have ceased. A slowing of biological activity under lake ice increases net mineralization and nitrification rates. This convergence of nitrogen cycling and winter streamflow produced a disproportionate flux of inorganic nitrogen from the study catchment. A conceptual model of how enhanced winter streamflow changes water chemistry in a lake-dominated shield landscape is proposed and may be used as a benchmark to guide hypotheses of process interactions, change in other landscapes, or across scales.

Spence, C.; Kokelj, S. V.; Kokelj, S. A.; McCluskie, M.; Hedstrom, N.

2015-01-01

344

Hibernation in an Antarctic Fish: On Ice for Winter  

PubMed Central

Active metabolic suppression in anticipation of winter conditions has been demonstrated in species of mammals, birds, reptiles and amphibians, but not fish. This is because the reduction in metabolic rate in fish is directly proportional to the decrease in water temperature and they appear to be incapable of further suppressing their metabolic rate independently of temperature. However, the Antarctic fish (Notothenia coriiceps) is unusual because it undergoes winter metabolic suppression irrespective of water temperature. We assessed the seasonal ecological strategy by monitoring swimming activity, growth, feeding and heart rate (fH) in N. coriiceps as they free-ranged within sub-zero waters. The metabolic rate of wild fish was extrapolated from fH recordings, from oxygen consumption calibrations established in the laboratory prior to fish release. Throughout the summer months N. coriiceps spent a considerable proportion of its time foraging, resulting in a growth rate (Gw) of 0.180.2% day?1. In contrast, during winter much of the time was spent sedentary within a refuge and fish showed a net loss in Gw (?0.050.05% day?1). Whilst inactive during winter, N. coriiceps displayed a very low fH, reduced sensory and motor capabilities, and standard metabolic rate was one third lower than in summer. In a similar manner to other hibernating species, dormancy was interrupted with periodic arousals. These arousals, which lasted a few hours, occurred every 412 days. During arousal activity, fH and metabolism increased to summer levels. This endogenous suppression and activation of metabolic processes, independent of body temperature, demonstrates that N. coriiceps were effectively putting themselves on ice during winter months until food resources improved. This study demonstrates that at least some fish species can enter a dormant state similar to hibernation that is not temperature driven and presumably provides seasonal energetic benefits. PMID:18320061

Campbell, Hamish A.; Fraser, Keiron P. P.; Bishop, Charles M.; Peck, Lloyd S.; Egginton, Stuart

2008-01-01

345

Comparison of camel tear proteins between summer and winter  

PubMed Central

Purpose Proteins in the tear fluid have positive effects on maintaining the integrity and stabilization of the tear film, which is affected by several environmental factors. The aim of this study is to investigate seasonal variation of protein patterns in camel tears collected during the summer and winter season. Methods Tears from both eyes of 50 clinically normal camels (Camelus dromedarius) were collected in the summer (June July) and in the winter (December January) respectively. Pooled tear protein samples from two seasons were separated by SDSPAGE and two-dimensional electrophoresis (2-DE). Protein spots of differential expression in two season gels were excised and subjected to in-gel digestion and identification by matrix assisted laser desorption/ionization-time of flight/time of flight-mass spectrum (MALDI-TOF/TOF-MS) analysis. Two differentially expressed proteins, lactoferrin (LF) and vitelline membrane outer layer protein 1 homolog (VMO1 homolog), were validated by western blotting. Results Thirteen well resolved bands were detected in SDSPAGE gels of both summer and winter camel tears. By band densitometry, significantly higher intensities of band 6, 7, 11, and lower intensity of band 13 were observed in the summer group compared to the winter group. In 2-DE profiles of camel tears, four protein spots were found expressed differentially in two seasons. Further protein identification by MALDI-TOF/TOF-MS and confirmation by western blotting indicated that there was a significant decrease in LF (p=0.002) and an increase in VMO1 homolog (p=0.042) in tears in the summer compared to the winter. Conclusions The seasonal variation of camel tear fluids has been found in the composition of proteins, including LF and VMO1 homolog. This result will expand our knowledge of physiologic characteristics of tear fluids and establish a foundation for the mechanistic studies and clinical practices on ocular surface disorders. PMID:21293736

Chen, Ziyan; Shamsi, Farrukh A.; Li, Kaijun; Huang, Qiang; Al-Rajhi, Ali A.; Chaudhry, Imtiaz A.

2011-01-01

346

Herbivory on shoalgrass by wintering redheads in Texas  

USGS Publications Warehouse

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.

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

1994-01-01

347

Animals in Winter. Young Discovery Library Series.  

ERIC Educational Resources Information Center

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

de Sairigne, Catherine

348

Nuclear Winter: Scientists in the Political Arena  

NASA Astrophysics Data System (ADS)

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

Badash, Lawrence

2001-03-01

349

CMPUT 631 Winter 2013 Robotics: Visual Navigation  

E-print Network

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

Zhang, Hong

350

Ghana Winter Study Tour 2014 Application Instructions  

E-print Network

Ghana Winter Study Tour 2014 Application Instructions Program Requirements: Applicants normally or to send it via email attachment. 2. Write a concise essay in which you describe your interest in the Ghana/02/2014 #12;Ghana Winter Study Tour 2014 Financial Aid Procedures Financial aid is applicable to this program

Suzuki, Masatsugu

351

Winter Icing and Storms Project (WISP)  

Microsoft Academic Search

Field studies in support of the Winter Icing and Storms Project (WISP) were conducted in the Colorado Front Range area from 1 February to 31 March 1990(WISP90) and from 15 January to 5 April 1991 (WISP91). The main goals of the project are to study the processes leading to the formation and depletion of supercooled liquid water in winter storms

Roy Rasmussen; Marcia Politovich; John Marwitz; Wayne Sand; John McGinley; John Smart; Roger Pielke; Steve Rutledge; Doug Wesley; Greg Stossmeister; Ben Bernstein; Kim Elmore; Nick Powell; Ed Westwater; B. Boba Stankov; Don Burrows

1992-01-01

352

ANS 2006 WINTER MEETING & Nuclear Technology Expo  

E-print Network

ANS 2006 WINTER MEETING & Nuclear Technology Expo "Ensuringthe for their support of the 2006 ANS Winter Meeting & Nuclear Technology Expo; Embedded Topical Meeting: TOFE 2006 support of the ANS Expo Special Events: Bechtel Nuclear Power BWX Technologies, Inc. Doosan HF Controls

Krings, Axel W.

353

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...

354

Influencing Travel Behaviour in a Winter City  

Microsoft Academic Search

Like many urban Canadians, Winnipeg residents view winter as a time to settle indoors and quickly scuttle from house to car to workplace or store. Children are prohibited by school division policy from playing outside during recess when the temperatures dip below -25 C. In Winnipeg winters, outdoor activity becomes seen by many as something to avoid. How does this

Beth McKechnie

355

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...

356

AN EVALUATION OF WINTER BIRD POPULATION STUDIES  

Microsoft Academic Search

HE only large body of data on population sizes of birds in winter is that contained in the winter bird population studies published annually since 1948 in Audubon Field Notes (now American Birds). The method used in these studies (Kolb, 1965) is that an observer traverses an area of known size six or more times (hereafter termed \\

RICHARD BREWER

357

PLCO News, Fall/Winter 1998  

Cancer.gov

PLCO News, Fall/Winter 1998 Volume 1, Number 2 ----- Fall/Winter 1998 TABLE OF CONTENTS Notes from theNCI's PLCO Project Office Meet John GohaganMeet Phil Prorok From Lab to Life Possible prostate cancer prevention with vitamin E and selenium

358

PLCO News, Fall/Winter 1998  

Cancer.gov

PLCO News, Fall/Winter 1998 Volume 1, Number 2 ----- Fall/Winter 1998 Trial Update Enrollment goal: 148,000 Total enrollment (as of September 30, 1998): 111,515 Men enrolled: 58,283 Women enrolled: 53,232 Number of people enrolled

359

PLCO News, Fall/Winter 1998  

Cancer.gov

PLCO News, Fall/Winter 1998 Volume 1, Number 2 ----- Fall/Winter 1998 Cancer Information Center If you have a question about cancer you can call and speak with a trained specialist at NCI's Cancer Information Service (CIS). The CIS operates a toll-free,

360

Ecological Energetics of Wintering Merlins Falco columbarius  

Microsoft Academic Search

The ability to maintain a balanced energ), budget through extendedperiods of ther- mal stress isa major determinant in the survival of birds resident in the north tem- perate zone during winter. We developed a time-energy budget for winter-accli- mated merlins ( Falco columbarius) to examine the relationship between energy expenditure and temperature, wind, and radiation and to learn how merlins

Ian G. Warkentin; Nigel H. West

361

Vernalization and epigenetics: how plants remember winter  

Microsoft Academic Search

One of the remarkable aspects of the promotion of flowering by vernalization is that plants have evolved the ability to measure a complete winter season of cold and to remember this prior cold exposure in the spring. Recent work in Arabidopsis demonstrates the molecular basis of this memory of winter: vernalization causes changes in the chromatin structure of a flowering

Sibum Sung; Richard M Amasino

2004-01-01

362

Plant improvement Winter climatic comparison between France  

E-print Network

Plant improvement Winter climatic comparison between France and New Zealand: effects of frost in the field before the 1987/1988 winter at all sites and also in spring 1988 at Angers. Plant death to have been derived from plants collected at lower latitude and low altitude sites. Popula- tions

Paris-Sud XI, Universit de

363

CULTIVAR DESCRIPTION CDC Kestrel winter wheat  

E-print Network

of the Canada Western Red Winter Wheat class. Key words: Triticum aestivum L., cultivar description, wheat (BAROC). Mots cls: Triticum aestivum L., description de cultivar, bl (d'automne) CDC Kestrel is a high-yielding, semidward winter wheat (Triticum aestivum L.) that was developed at the Crop Development Centre, University

Saskatchewan, University of

364

Winter Term University of Oldenburg (Core Provider)  

E-print Network

Evaluation Modul Winter Term Titel Wind Energy Wind Energy I Wind Tutorial Wind Energy Systems Wind Energy Conversion (Lab) Excursion/Wind/DEWI Modul Winter Term Titel Solar Energy PV Systems I Solar Thermal I Solar Tutorial PV Cell Characteristics (Lab) Solar

Habel, Annegret

365

Excess Winter Mortality and Cold Temperatures in a Subtropical City, Guangzhou, China  

PubMed Central

Background A significant increase in mortality was observed during cold winters in many temperate regions. However, there is a lack of evidence from tropical and subtropical regions, and the influence of ambient temperatures on seasonal variation of mortality was not well documented. Methods This study included 213,737 registered deaths from January 2003 to December 2011 in Guangzhou, a subtropical city in Southern China. Excess winter mortality was calculated by the excess percentage of monthly mortality in winters over that of non-winter months. A generalized linear model with a quasi-Poisson distribution was applied to analyze the association between monthly mean temperature and mortality, after controlling for other meteorological measures and air pollution. Results The mortality rate in the winter was 26% higher than the average rate in other seasons. On average, there were 1,848 excess winter deaths annually, with around half (52%) from cardiovascular diseases and a quarter (24%) from respiratory diseases. Excess winter mortality was higher in the elderly, females and those with low education level than the young, males and those with high education level, respectively. A much larger winter increase was observed in out-of-hospital mortality compared to in-hospital mortality (45% vs. 17%). We found a significant negative correlation of annual excess winter mortality with average winter temperature (rs=-0.738, P=0.037), but not with air pollution levels. A 1 C decrease in monthly mean temperature was associated with an increase of 1.38% (95%CI:0.34%-2.40%) and 0.88% (95%CI:0.11%-1.64%) in monthly mortality at lags of 0-1 month, respectively. Conclusion Similar to temperate regions, a subtropical city Guangzhou showed a clear seasonal pattern in mortality, with a sharper spike in winter. Our results highlight the role of cold temperature on the winter mortality even in warm climate. Precautionary measures should be strengthened to mitigate cold-related mortality for people living in warm climate. PMID:24116214

Yang, Jun; Chau, Patsy Yuen-Kwan; Yang, Lin; Chen, Ping-Yan; Wong, Chit-Ming

2013-01-01

366

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

USGS Publications Warehouse

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.

Kelly, V.J.

1996-01-01

367

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

Microsoft Academic Search

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.

David L. Swanson

2001-01-01

368

Ecotoxicological simulation modeling: effects of agricultural chemical exposure on wintering burrowing owls  

E-print Network

to insecticides may be a factor in the decline of their population. Burrowing owls wintering in southern Texas use agricultural culverts in cotton fields as roost sites, which may increase their risk of exposure to agricultural chemicals, either through... ingestion of contaminated prey or through dermal exposure to agricultural runoff. Simulation modeling was used to characterize the risks to individual burrowing owls wintering in agricultural landscapes in southern Texas due to effects of exposure...

Engelman, Catherine Allegra

2008-10-10

369

Does the lack of vernalization requirement interfere with winter survival of oilseed rape plants?  

Microsoft Academic Search

Recent studies (Rapacz 1999) have shown that cultivars of spring-type oilseed rape are able to cold-acclimate to the level\\u000a comparable with winter cultivars, but only after prehardening which results both in the increase of photosynthetic activity\\u000a and in growth cessation. It is commonly known that under field conditions spring-type cultivars could not survive winter.\\u000a Present studies were undertaken to explain

Marcin Rapacz; Ewa Chilmonik

2000-01-01

370

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

Microsoft Academic Search

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

Gregorio Moreno-Rueda

371

Proline biosynthesis in winter plants due to exposure to low temperatures  

Microsoft Academic Search

The content of bound proline sharply increased in proteins of different organs of young plants of winter rape and winter wheat\\u000a exposed for 72 h to temperatures from 0 to 2 C while it decreased only in root tips of wheat plants. Free proline which at\\u000a 20 C occurs in all plant organs only in trace amounts, accumulated considerably after

M. tefl; I. Tr?ka; P. Vrtn

1978-01-01

372

Winter Olympics Physics and Biomechanics  

NSDL National Science Digital Library

Many Winter Olympic sports are greatly dependent on technique, engineering, and/or gravity. For example, during luge, while gravity is accelerating the sled up to 80 mph down the track, the slider must use good technique to steer the sled and minimize air resistance. To excel in these type of sports, it is helpful to have a full appreciation of physics and biomechanics. Physics is a broad field which includes mechanics, electricity, magnetism, optics, etc., and biomechanics is the study of the mechanics of living systems. In the module we will use the sports of luge and figure skating to teach you four basic mechanical concepts: linear kinematics, linear dynamics, projectile motion, and conservation of angular momentum. In addition, we have developed a glossary which defines and illustrates all the physics terminology you will need to complete this module.

373

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

NASA Astrophysics Data System (ADS)

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 Nio-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 Nio than in neutral or La Nia winters. Production and value of tomatoes were higher in La Nia winters. The yield response can be explained by increased rainfall, reduced daily maximum temperatures, and reduced solar radiation in El Nio 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 Nio events have important implications for both producers and consumers of winter vegetables, and suggest opportunities for further research.

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

1999-01-01

374

Connection between autumn Sea Surface Temperature and winter precipitation in the Iberian Peninsula  

NASA Astrophysics Data System (ADS)

The oceanic influence on winter precipitation in the Iberian Peninsula has been evidenced in numerous scientific papers. Large-scale forecasting models generally use variables such as Sea Surface Temperature (SST), soil moisture and ice cover, but they are not very accurate yet. Using observational data, this paper analyzes the influence of North Atlantic and Mediterranean SST on winter precipitation in the Iberian Peninsula between October 1951 and September 2011. First, trends of both data sets have been calculated to study their behavior during the past six decades, showing an overall increase of SST and a substantial decrease in winter precipitation in the Iberian Peninsula, except in eastern and south-eastern regions. Then, connection patterns between autumn Sea Surface Temperature Anomalies and winter precipitation have been studied to identify ocean regions that may be used as potential predictors of winter precipitation. After applying a Principal Component Analysis to cluster the information provided by the 1431 measuring points of a SST grid with a small number of variables, the Principal Components extracted were introduced into a Multiple Linear Regression algorithm in order to obtain an estimation of winter precipitation in each river basin. The validation process has shown that the algorithm explains nearly 50% of inter-annual variability of winter precipitation in the basins of the Iberian Peninsula with a strongly oceanic influence; this percentage is somewhat lower in the Mediterranean regions.

Fernndez-Gonzlez, Sergio; Pereira, Susana C.; Castro, Amaya; Rocha, Alfredo; Fraile, Roberto

2014-10-01

375

Temperature characteristics of winter roost-sites for birds and mammals: tree cavities and anthropogenic alternatives  

NASA Astrophysics Data System (ADS)

The microclimate of potential roost-sites is likely to be a crucial determinant in the optimal roost-site selection of endotherms, in particular during the winter season of temperate zones. Available roost-sites for birds and mammals in European high trunk orchards are mainly tree cavities, wood stacks and artificial nest boxes. However, little is known about the microclimatic patterns inside cavities and thermal advantages of using these winter roost-sites. Here, we simultaneously investigate the thermal patterns of winter roost-sites in relation to winter ambient temperature and their insulation capacity. While tree cavities and wood stacks strongly buffered the daily cycle of temperature changes, nest boxes showed low buffering capacity. The buffering effect of tree cavities was stronger at extreme ambient temperatures compared to temperatures around zero. Heat sources inside roosts amplified ? T (i.e., the difference between inside and outside temperatures), particularly in the closed roosts of nest boxes and tree cavities, and less in the open wood stacks with stronger circulation of air. Positive ? T due to the installation of a heat source increased in cold ambient temperatures. These results suggest that orchard habitats in winter show a spatiotemporal mosaic of sites providing different thermal benefits varying over time and in relation to ambient temperatures. At cold temperatures tree cavities provide significantly higher thermal benefits than nest boxes or wood stacks. Thus, in winter ecology of hole-using endotherms, the availability of tree cavities may be an important characteristic of winter habitat quality.

Grebler, Martin U.; Widmer, Silv; Korner-Nievergelt, Frnzi; Naef-Daenzer, Beat

2014-07-01

376

Changes in the structure of the rhizosphere complex of actinomycetes in the ontogenesis of winter rye  

NASA Astrophysics Data System (ADS)

Changes in the taxonomic structure of actinomycetes in the rhizosphere of winter rye ( Secale cereale L.) growing on acid soddy-podzolic soil were studied. During the first stages of ontogenesis of winter rye, the rhizosphere complex of mycelial prokaryotes was characterized by a relatively level generic structure (with respect to the indices of abundance and frequency of particular genera), low values of the species diversity, and low domination frequency of the species from the Streptomyces genus. The numbers and species diversity of the streptomycetes increased during the further growth of the winter rye, so that streptomycetes became a dominant group in the complex of the rhizosphere actinomycetes. According to the two-way ANOVA, the population density of the Micromonospora and the Streptosporangium genera in the rhizosphere was mainly dictated by the winter rye variety, whereas the population density of the streptomycetes depended on the particular stage of the winter rye development. The differences between the actinomycetal complexes characteristic of different varieties of winter rye at the early stages of its development was leveled by the end of the winter rye growth.

Shirokikh, I. G.; Merzaeva, O. V.; Zenova, G. M.

2006-06-01

377

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

PubMed

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

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

2012-10-01

378

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

PubMed

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

Durn, Jorge; Rodrguez, Alexandra; Morse, Jennifer L; Groffman, Peter M

2013-09-01

379

Record-breaking Ozone Loss during Arctic Winter 2010/2011: Comparison with Arctic Winter 1996/1997  

NASA Astrophysics Data System (ADS)

Polar processing and chemical ozone loss is analysed during the Arctic winter/spring 2010/2011. The analyses with temperatures and potential vorticity (PV) data show a prolonged vortex from early December through mid-April. The PV maps illustrate strong vortex persistence in the lower stratosphere between 450 and 675 K, showing similar evolution with time. The minimum temperatures extracted from ECMWF data at 40-90N show values below 195 K for a record period of first week of December through second week of April, indicating the longest period of colder temperatures for 17 years. At 10 hPa, there was a warming of about 10 K at 60N and 40 K at 90N around mid-January. The heat flux also showed high values in line with the increase in temperatures, of about 425 m K/s at 60N at the same pressure level. However, the westerlies were strong (e.g. 35-45 m/s at 60N) enough to keep the vortex intact until mid-April. Because of the cold temperatures in late winter and early spring, large areas of Polar Stratospheric Clouds (PSC) were found in the 400-600 K isentropic level range. Though the maximum values of PSCs area are smaller compared to other cold winters such as 2005, the extended period of presence of PSCs during this winter was exceptional, especially in late February-mid-March, in agreement with the cold temperatures during the period. Ozone loss analyses with high resolution Mimosa-Chim chemical transport model simulations show that the loss started by early January, and was about 0.5 ppmv in late January. The loss progressed slowly to 1 ppmv by the end of February, and then intensified by early March. The ozone depletion estimated by the passive method finds a maximum value of about 2-2.3 ppmv by the end of March-early April in the 450-550K range inside the vortex, which coincides with the areas of PSCs and high chlorine activation. This is the largest loss ever estimated with this model for any Arctic winter. It is consistent with the unprecedented chlorine activation that occurred in the winter, as the modeled ClO values show about 1.7 ppbv in early January and about 1 ppbv in March at 450-550K. This is longest period of chlorine activation noted among the Arctic winters. The ozone partial column loss reaches about 115-150 DU in the range 350 - 550 K. These model results for ozone, ozone loss and ClO are in good agreement with those found from Aura Microwave Limb Sounder observations. Since the winter 1996/1997 was also very cold in March - April, a comparison between both winters 2011 and 1997 will be presented, based on temperature, PV, Heat flux data and ozone loss estimations. Similarities and differences in the polar processing and ozone loss during both winters will be discussed using various measurements and model simulations. Copyright 2011. All rights reserved.

Godin Beekmann, S.; Kuttipurath, J.; Lefvre, F.; Santee, M. L.; Froidevaux, L.

2011-12-01

380

Red spruce decline---Winter injury and air pollutants  

SciTech Connect

There has been a widespread decline in growth of red spruce (Picea rubens Sarg.) since 1960 in the eastern United States. There is evidence that this decline is at least partly attributable to age- and density-related growth patterns, particularly at lower elevations. Mortality has been severe at high elevation sites where similar episodes have occasionally occurred in the last 100 years. At these sites, periods of low growth preceding 1960 were related to periods with warm late summers and cold early winters. Since 1960, this relationship no longer holds, although there is an association with unusual deviations from mean temperatures. There are field reports that one of the main causes of reduced growth and mortality is apical dieback induced by severe winter conditions. Preliminary observations suggest that high elevation red spruce may not be sufficiently hardened to tolerate low autumn temperatures. However, appearance of injury in the spring, association of injury with wind exposure and correlation of provenance susceptibility with cuticular transpiration rates, including the importance of desiccation injury. Sensitivity to both types of winter injury may be increased by air pollutants (particularly ozone and less probably, acid mist or excess nitrogen deposition). Nutrient deficiency (particularly magnesium and to a lesser extent potassium) may also increase cold sensitivity. The nature and extent of these interactions are being actively researched for red spruce. 48 refs.

Roberts, T.M. (Central Electricity Research Labs., Leatherhead (UK))

1989-10-01

381

Climate warming will not decrease winter mortality  

NASA Astrophysics Data System (ADS)

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.

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

2014-03-01

382

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

PubMed

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

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

2014-10-01

383

Role of roots in winter water relations of Engelmann spruce saplings.  

PubMed

Roots play a role in maintaining foliar water balance in subalpine conifer saplings during winter. We used deuterium-labeled water to demonstrate that roots of Engelmann spruce (Picea engelmannii Parry) take up water during the late-winter-early spring period. Based on a root severing experiment, we conclude that small, snow-covered saplings were largely dependent on root water uptake to meet winter transpiration needs, whereas larger saplings relied more on water stored in stem sapwood. Both water uptake and water stored in roots appeared to be critical for the survival of saplings exposed above the snowpack during the late-winter-early spring period, when sap reserves were insufficient to meet increasing transpirational demands. PMID:10562407

Boyce; Lucero

1999-11-01

384

[Population trends and behavioral observations of wintering common cranes (Grus grus) in Yancheng Nature Reserve].  

PubMed

To understand the population status and behavioural features of wintering common cranes in the Yancheng Nature Reserve, two transects were established and population trends were monitored every month over five recent winters from 2008 to 2013. Wintering behaviours were also observed in order to explore the possible effects of family size and age on time budgets. Results indicated that the populations were stable with a range of 303 to 707 individuals. Negative effects of coastal developments were not found on the wintering population of common cranes, which might be related to their diets and preference for artificial wetland habitats. We found a significant effect of age on time budgets, with juveniles spending more time feeding and less time alerting, which might be related to the needs of body development and skill learning. Family size did not affect the time budgets of the cranes, which indicated that adults did not increase vigilance investment even when raising a larger family. PMID:24115655

Li, Zhong-Qiu; Wang, Zhi; Ge, Chen

2013-10-01

385

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

USGS Publications Warehouse

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.

Herring, G.; Collazo, J.A.

2006-01-01

386

Winter weather versus group thermoregulation: what determines survival in hibernating mammals?  

PubMed

For socially hibernating mammals, the effectiveness of huddling as a means of energy conservation should increase with group size. However, group size has only been linked to increased survival in a few hibernating species, and the relative importance of social structure versus winter conditions during hibernation remains uncertain. We studied the influence of winter weather conditions, social group composition, age-structure, and other environmental factors and individual attributes on the overwinter survival of hoary marmots (Marmota caligata) in the Yukon Territory, Canada. Juvenile hoary marmot survival was negatively correlated with the mean winter (November to May) Pacific Decadal Oscillation (PDO) index. Survival in older age-classes was negatively correlated with PDO lagged by 1 year. Social group size and structure were weakly correlated with survival in comparison to PDO. The relationship between winter PDO and survival was most likely due to the importance of snowpack as insulation during hibernation. The apparent response of hoary marmots to changing winter conditions contrasted sharply with those of other marmot species and other mammalian alpine herbivores. In conclusion, the severity of winter weather may constrain the effectiveness of group thermoregulation in socially hibernating mammals. PMID:23456241

Patil, V P; Morrison, S F; Karels, T J; Hik, D S

2013-09-01

387

Rapid climate driven shifts in wintering distributions of three common waterbird species.  

PubMed

Climate change is predicted to cause changes in species distributions and several studies report margin range shifts in some species. However, the reported changes rarely concern a species' entire distribution and are not always linked to climate change. Here, we demonstrate strong north-eastwards shifts in the centres of gravity of the entire wintering range of three common waterbird species along the North-West Europe flyway during the past three decades. These shifts correlate with an increase of 3.8C in early winter temperature in the north-eastern part of the wintering areas, where bird abundance increased exponentially, corresponding with decreases in abundance at the south-western margin of the wintering ranges. This confirms the need to re-evaluate conservation site safeguard networks and associated biodiversity monitoring along the flyway, as new important wintering areas are established further north and east, and highlights the general urgency of conservation planning in a changing world. Range shifts in wintering waterbirds may also affect hunting pressure, which may alter bag sizes and lead to population-level consequences. PMID:23509023

Lehikoinen, Aleksi; Jaatinen, Kim; Vhtalo, Anssi V; Clausen, Preben; Crowe, Olivia; Deceuninck, Bernard; Hearn, Richard; Holt, Chas A; Hornman, Menno; Keller, Verena; Nilsson, Leif; Langendoen, Tom; Tomnkov, Irena; Wahl, Johannes; Fox, Anthony D

2013-07-01

388

Evolution of microwave limb sounder ozone and the polar vortex during winter  

SciTech Connect

The evolution of polar ozone observed by the Upper Atmosphere Research Satellite (UARS) Microwave Limb Sounder (MLS) is described for the northern hemisphere (NH) winters of 1991/1992, 1992/1993, and 1993/1994 and the southern hemisphere (SH) winters of 1992 and 1993. Imterannual and interhemispheric variability in polar ozone evolution are closely related to differences in the polar vortex and to the frequency, duration and strength of stratospheric sudden warmings. Ozone in the midstratospheric vortices increases during the winter, with largest increases associated with stratospheric warmings and a much larger increase in the NH than in the SH. A smaller NH increase was observed in 1993/1994, when the middle stratospheric vortex was stronger. During strong stratospheric warmings in the NH, the upper stratospheric vortex may be so much eroded that it presents little barrier to poleward transport; in contrast, the SH vortex remains strong throughout the stratosphere during wintertime warmings, and ozone increases only below the mixing ratio peak, due to enhanced diabatic descent. Ozone mixing ratios decrease rapidly in the lower stratosphere in both SH late winters, as expected from chemical destruction due to enhanced reactive chlorine. The interplay between dynamics and chemistry is more complex in the NH lower stratosphere and interannual variability is greater. Evidence has previously been shown for chemical ozone destruction in the 1991/1992 and 1992/1993 winters.

Manney, G.L.; Froidevaux, L.; Waters, J.W.; Zurek, R.W. [Jet Propulsion Lab., California Inst. of Tech., Pasadena, CA (United States)] [Jet Propulsion Lab., California Inst. of Tech., Pasadena, CA (United States)

1995-02-01

389

Sarcocystis in American black ducks wintering in New Jersey.  

PubMed

Macrocysts of a protozoan parasite, Sarcocystis sp., were found in 28 of 173 American black ducks (Anas rubripes) examined during winters 1984-1985, 1985-1986 and 1986-1987 in south coastal New Jersey (USA). No macrocysts were detected in 80 juvenile black ducks. In adults, the prevalence of macrocysts increased from 3% (1 of 37) in 1984-1985, to 36% (12 of 33) in 1985-1986, and 65% (15 of 23) in 1986-1987. This increase could result in a greater number of harvested birds being discarded, or a change in the attitudes of waterfowl hunters towards black ducks. PMID:2117676

Costanzo, G R

1990-07-01

390

Variability of Winter Air Temperature in Mid-Latitude Europe  

NASA Technical Reports Server (NTRS)

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.

Otterman, J.; Ardizzone, J.; Atlas, R.; Bungato, D.; Cierniewski, J.; Jusem, J. C.; Przybylak, R.; Schubert, S.; Starr, D.; Walczewski, J.

2002-01-01

391

Comparison of snowpack and winter wet-deposition chemistry in the Rocky Mountains, USA: Implications for winter dry deposition  

USGS Publications Warehouse

Depth-integrated snowpack chemistry was measured just prior to maximum snowpack depth during the winters of 1992-1999 at 12 sites co-located with National Atmospheric Deposition Program/National Trend Network (NADP/NTN) sites in the central and southern Rocky Mountains, USA. Winter volume-weighted mean wet-deposition concentrations were calculated for the NADP/NTN sites, and the data were compared to snowpack concentrations using the paired t-test and the Wilcoxon signed-rank test. No statistically significant differences were indicated in concentrations of SO42- or NO3- (p>0.1). Small, but statistically significant differences (p???0.03) were indicated for all other solutes analyzed. Differences were largest for Ca2+ concentrations, which on average were 2.3??eql-1 (43%) higher in the snowpack than in winter NADP/NTN samples. Eolian carbonate dust appeared to influence snowpack chemistry through both wet and dry deposition, and the effect increased from north to south. Dry deposition of eolian carbonates was estimated to have neutralized an average of 6.9??eql-1 and a maximum of 12??eql-1 of snowpack acidity at the southernmost sites. The good agreement between snowpack and winter NADP/NTN SO42- and NO3- concentrations indicates that for those solutes the two data sets can be combined to increase data density in high-elevation areas, where few NADP/NTN sites exist. This combination of data sets will allow for better estimates of atmospheric deposition of SO42- and NO3- across the Rocky Mountain region.

Clow, D.W.; Ingersoll, G.P.; Mast, M.A.; Turk, J.T.; Campbell, D.H.

2002-01-01

392

EPS Workshop on Nuclear Winters  

NASA Astrophysics Data System (ADS)

This workshop was held in Geneva in October 1986 and was attended by invited delegates from both East (14) and West (13), members of the ACPS (5) and the President. Relevant disciplines as well as Physics were represented which lead to comprehensive discussions. The factors which have a bearing on the probabilities of a nuclear winter were reviewed using the SCOPE-ENUWAR studies as a basis. These covered the nature of a possible nuclear war; the quantities of dust and smoke thrown into the atmosphere, its particle size, height and lifetime; the resulting effects on sunlight and temperature; and the consequences for vegetation and animal life both terrestrial and marine. There are many uncertainties in such analyses. Much more work is needed on many facets. The more important were highlighted as further topics for East-West collaboration. Never the less it was concluded that:- Climatic effects involving temperature falls of only three or four degrees below normal combined with a large fall in light intensity during the growing season of cereal crops would have disastrous consequences.

Parkinson, D. H.

1988-01-01

393

Autumnwinter diet of Grey Partridges Perdix perdix in winter crops, stubble fields and fallows  

Microsoft Academic Search

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

Grzegorz Or?owski; Joanna Czarnecka; Marek Panek

2011-01-01

394

Earth-Sun Geometry: Winter Solstice Animation  

NSDL National Science Digital Library

The representation depicts the position of the Earth relative to the Sun during the southern hemisphere's winter solstice and includes line of latitude and the angle of the Sun's rays at the Tropic of Capricorn.

Michael Pidwirny

395

Probabilistic Weather Forecasting for Winter Road Maintenance  

E-print Network

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

Washington at Seattle, University of

396

Supercooling and Freezing in Winter Dormant Animals  

NSDL National Science Digital Library

This resource is a manual for instructing students in a laboratory exercise examining the effects of winter-time supercooling and freezing on animals. This lab would be a suitable supplement to animal physiology or physiological ecology courses.

William D. Schmid (University of Minnesota; )

1988-01-01

397

AMAT/PMAT 4282 { Winter 2001 Cryptography  

E-print Network

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

deYoung, Brad

398

Essential Outdoor Sun Safety Tips for Winter  

MedlinePLUS

... the risk for damage. Both snow and strong wind can wear away sunscreen and reduce its effectiveness, ... protect your skin from the bitter cold, heavy winds and winter sun, follow these important sun protection ...

399

Winter warming from large volcanic eruptions  

SciTech Connect

An examination of the Northern Hemisphere winter surface temperature patterns after the 12 largest volcanic eruptions from 1883-1992 shows warming over Eurasia and North America and cooling over the Middle East which are significant at the 95% level. This pattern is found in the first winter after tropical eruptions, in the first or second winter after midlatitude eruptions, and in the second winter after high latitude eruptions. The effects are independent of the hemisphere of the volcanoes. An enhanced zonal wind driven by heating of the tropical stratosphere by the volcanic aerosols is responsible for the regions of warming, while the cooling is caused by blocking of incoming sunlight. 21 refs., 2 figs., 1 tab.

Robock, A.; Jianping Mao (Univ. of Maryland, College Park (United States))

1992-12-24

400

Mojave sandy desert habitat in Winter (February)  

NSDL National Science Digital Library

By winter in non-drought years, the Mojave has received several inches of rain and healthy vegetation will begin to break ground by February. However, during drought years, vegetation will not experience its rapid growth season until spring.

Katie Hale (California State University, Fullerton; Student, Biological Sciences)

2007-01-06

401

How to Find Insects Weathering the Winter.  

ERIC Educational Resources Information Center

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)

Brody, Jane

1979-01-01

402

NEW INTERNSHIP FOR WINTER Interactive Ecology  

E-print Network

NEW INTERNSHIP FOR WINTER Interactive Ecology UC Santa Cruz Arboretum Internship Agency Sponsor within the California Native Plant Conservation Program in the UC Santa Cruz Arboretum. Physical activities will include building plant collections through seed germination, propagation, nursery work

Wilmers, Chris

403

Building a Weather-Ready Nation Winter Weather Safety  

E-print Network

Building a Weather-Ready Nation Winter Weather Safety NOAA/NWS Winter Weather Safety Seasonal Campaign www.weather.gov #12;Building a Weather-Ready Nation Winter Weather Hazards Winter Weather Safety www.weather.gov · Snow/Ice · Blizzards · Flooding · Cold Temperatures #12;Building a Weather

404

Winter Cereal Forages Could Help Reduce Drought By David Wichman  

E-print Network

years, the Montana Ag Experiment Station has evaluated winter spelt, winter triticale and awnless winter and grain production potential. Gil Stallknecht has been evaluating awnless winter spelt lines for both lines. Seed is not available to producers yet. One spelt development line, 'Frank,' is a selection from

Maxwell, Bruce D.

405

Examining Winter Visitor Use in Yellowstone National Park  

Microsoft Academic Search

This research was designed to assist the managers of Yellowstone National Park (YNP) in their decision making about winter visitation. The focus of this report is on winter use patterns and winter visitor preferences. It is the author's hope that this information will benefit both the quality of winter experiences and the stewardship of the park resources. This report addresses

Mae A. Davenport; Wayne A. Freimund; William T. Borrie; Robert E. Manning; William A. Valliere; Benjamin Wang

406

Solvent winterization of sunflower seed oil  

Microsoft Academic Search

Samples of oil from whole and dehulled sunflower seed were solvent winterized. The solvent mixture, 85% acetone, 15% hexane\\u000a (v\\/v), was used at solvent-in-oil concentrations of 20, 40, and 70% by wt and the samples winterized at 0, ?5, ?10, and ?15\\u000a .01 C for 4 hr. Generally, sunflower oils from whole seed remained free from cloud formation longer on

W. Herbert Morrison; James A. Robertson

1975-01-01

407

Winter survival of Eurasian woodcock Scolopax rusticola in central Italy  

USGS Publications Warehouse

The Eurasian woodcock Scolopax rusticola is a popular game bird in much of Europe. However, little is known about its population dynamics. We estimated winter survival of woodcock in a protected area with no hunting in central Italy. We radio-tagged 68 woodcocks with battery-powered radio-transmitters during 2001-2005. Woodcocks were captured in fields at night from November through February and fitted with radios. Birds were classified on capture as juveniles or adults using plumage characteristics. Woodcocks were relocated daily through March of each year or until they died, disappeared from the study area, or until their radio failed. We constructed a set of eight competing models of daily survival for the period 1 December - 28 February. Estimates of survival were obtained using the program SURVIV and Akaike's Information Criteria. The best model suggested daily survival was a constant 0.9985 (95% CI = 0.9972-0.9998), corresponding to a survival rate of 0.88 (SE = 0.05) for the 90-day winter study period. Our estimate of juvenile survival is higher than previously reported, and may reflect the protected status of the study area. Our estimates of winter survival may be helpful in managing harvested woodcock populations as well as in conserving populations in an increasingly urbanised environment. ?? Wildlife Biology (2008).

Aradis, A.; Miller, M.W.; Landucci, G.; Ruda, P.; Taddei, S.; Spina, F.

2008-01-01

408

Winter Survival of Transgenic Alfalfa Overexpressing Superoxide Dismutase1  

PubMed Central

To test the hypothesis that enhanced tolerance of oxidative stress would improve winter survival, two clones of alfalfa (Medicago sativa) were transformed with a Mn-superoxide dismutase (Mn-SOD) targeted to the mitochondria or to the chloroplast. Although Mn-SOD activity increased in most primary transgenic plants, both cytosolic and chloroplastic forms of Cu/Zn-SOD had lower activity in the chloroplast SOD transgenic plants than in the nontransgenic plants. In a field trial at Elora, Ontario, Canada, the survival and yield of 33 primary transgenic and control plants were compared. After one winter most transgenic plants had higher survival rates than control plants, with some at 100%. Similarly, some independent transgenic plants had twice the herbage yield of the control plants. Prescreening the transgenic plants for SOD activity, vigor, or freezing tolerance in the greenhouse was not effective in identifying individual transgenic plants with improved field performance. Freezing injury to leaf blades and fibrous roots, measured by electrolyte leakage from greenhouse-grown acclimated plants, indicated that the most tolerant were only 1C more freezing-tolerant than alfalfa clone N4. There were no differences among transgenic and control plants for tetrazolium staining of field-grown plants at any freezing temperature. Therefore, although many of the transgenic plants had higher winter survival rates and herbage yield, there was no apparent difference in primary freezing injury, and therefore, the trait is not associated with a change in the primary site of freezing injury. PMID:10069823

McKersie, Bryan D.; Bowley, Stephen R.; Jones, Kim S.

1999-01-01

409

[Spatial distribution characteristics of NMHCs during winter haze in Beijing].  

PubMed

NMHCs and NOx samples were simultaneously collected and analyzed in six urban and suburban representative sampling sites (Sihuan, Tian'anmen, Pinguoyuan, Fatou, Beijing Airport and Miyun) during a typical haze period in winter 2005, Beijing. The concentrations of NMHCs during the sampling period in descending order were: Sihuan (1101.29 microg x m(-3)) > Fatou (692.40 microg x m(-3)) >Tian'anmen (653.28 microg x m(-3)) >Pinguoyuan (370.27 microg x m(-3)) > Beijing Airport (350.36 microg x m(-3)) > Miyun (199.97 microg x m(-3)). Atmospheric benzene pollution in Beijing was rather serious. The ratio of NMHCs/NOx ranged from 2.1 to 6.3, indicating that the peak ozone concentrations in urban Beijing were controlled by VOCs during the sampling period. Analysis of propylene equivalent concentration and ozone formation potential showed that the NMHCs reactivity descended in the order of Sihuan > Fatou > Tian'anmen > Pinguoyuan > Beijing Airport > Miyun. B/T values (0.52 to 0.76) indicated that besides motor vehicle emission, coal combustion and other emission sources were also the sources of NHMCs in Beijing in winter. The spatial variations of isoprene in Beijing indicated that the contribution of anthropogenic sources to isoprene increased and the emissions by biogenic sources decreased in winter. The spatial variations of propane and butane indicated that LPG emissions existed in the urban region of Beijing. PMID:24640889

Duan, Jing-Chun; Peng, Yan-Chun; Tan, Ji-Hua; Hao, Ji-Ming; Chai, Fa-He

2013-12-01

410

Winter survival of transgenic alfalfa overexpressing superoxide dismutase  

PubMed

To test the hypothesis that enhanced tolerance of oxidative stress would improve winter survival, two clones of alfalfa (Medicago sativa) were transformed with a Mn-superoxide dismutase (Mn-SOD) targeted to the mitochondria or to the chloroplast. Although Mn-SOD activity increased in most primary transgenic plants, both cytosolic and chloroplastic forms of Cu/Zn-SOD had lower activity in the chloroplast SOD transgenic plants than in the nontransgenic plants. In a field trial at Elora, Ontario, Canada, the survival and yield of 33 primary transgenic and control plants were compared. After one winter most transgenic plants had higher survival rates than control plants, with some at 100%. Similarly, some independent transgenic plants had twice the herbage yield of the control plants. Prescreening the transgenic plants for SOD activity, vigor, or freezing tolerance in the greenhouse was not effective in identifying individual transgenic plants with improved field performance. Freezing injury to leaf blades and fibrous roots, measured by electrolyte leakage from greenhouse-grown acclimated plants, indicated that the most tolerant were only 1 degrees C more freezing-tolerant than alfalfa clone N4. There were no differences among transgenic and control plants for tetrazolium staining of field-grown plants at any freezing temperature. Therefore, although many of the transgenic plants had higher winter survival rates and herbage yield, there was no apparent difference in primary freezing injury, and therefore, the trait is not associated with a change in the primary site of freezing injury. PMID:10069823

McKersie; Bowley; Jones

1999-03-01

411

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

SciTech Connect

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.

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

2011-11-11

412

Winter energetics of female Indiana bats Myotis sodalis.  

PubMed

Understanding physiological limits and environmental optima is critical to developing protection strategies for endangered and threatened species. One theory to explain the decline in endangered Indiana bat Myotis sodalis populations involves increasing cave temperatures in winter hibernacula. Altered cave temperatures can raise metabolism and cause more arousals in torpid bats, both of which use more fat reserves. In addition, fluctuations in cave temperatures may cause additional arousals. Our objectives were to quantify the effect of temperature and fluctuations thereof on torpid metabolism and arousal frequency in this species. Female Indiana bats (n=36) were collected from caves just before hibernation, maintained in an environmental chamber that simulated hibernacula conditions, and had skin temperature recorded every 30 min throughout the winter. One environmental chamber containing bats (n=12) was sequentially set at 8, 6, and 4C over the winter. The second chamber containing bats (n=12) experienced the same mean temperatures, but temperature fluctuated 2C on a regular basis. Torpor bouts were longest at 4C and were not affected by temperature fluctuations. However, the temperature fluctuations appeared to cause longer arousals. Other bats (n=12) were individually placed in metabolic chambers to calculate oxygen consumption during torpor and during arousals. Torpid metabolism was affected by temperature; at 9C, it was higher than at 7 or 5C. Metabolism during arousals was not different among temperature treatments, but rates were almost 200 times higher than torpid metabolic rates. We calculated a winter energy budget and, from the energetic perspective, determined an optimum hibernation temperature (3-6C) for female Indiana bats. These findings suggest that hibernacula that provide these conditions deserve extra protection, although other factors in addition to energetics may play a role in temperature preferences. PMID:24457921

Day, Katie M; Tomasi, Thomas E

2014-01-01

413

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

USGS Publications Warehouse

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 (19702000) and mangrove forest and salt marsh habitat data. Our results identify winter climate thresholds for salt marshmangrove 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.

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

2013-01-01

414

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

PubMed

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: Msum ) 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 Msum 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 Msum 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 Msum 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. J. Exp. Zool. 323A: 179-190, 2015. 2015 Wiley Periodicals, Inc. PMID:25690265

Corts, Pablo Andrs; Petit, Magali; Lewden, Agns; Milbergue, Myriam; Vzina, Franois

2015-03-01

415

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

PubMed

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

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

2013-05-01

416

Low temperature cardiac response to exhaustive exercise in fish with different levels of winter quiescence.  

PubMed

We examined the cardiac responses of different fish species to anaerobic exercise at low temperatures (3 degrees C). Three species of sympatric warmwater fish with perceived differences in winter activity were used for this comparative study: the winter-quiescent largemouth bass (Micropterus salmoides); the winter-active white bass (Morone chrysops); and the intermediately winter-active black crappie (Pomoxis nigromaculatus). Perceived differences in winter activity were reflected in cardiac responses; e.g. basal cardiac values were lowest for largemouth bass, highest for white bass, and intermediate for black crappie. In addition, cardiac recovery was most rapid for white bass, slowest for largemouth bass and intermediate for black crappie. When disturbed at low temperatures, largemouth bass and black crappie elevated cardiac output principally through increases in heart rate despite substantial decreases in stroke volume. Conversely, white bass principally used stroke volume modulation to change cardiac output. The results of this study indicate that different species respond differently to exercise at low temperatures. Management strategies should recognize that such variation exists and ensure that management decisions are based upon an understanding of the low temperature exercise physiology and winter biology of the species of interest. PMID:12507619

Cooke, Steven J; Grant, Emily C; Schreer, Jason F; Philipp, David P; Devries, Arthur L

2003-01-01

417

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

NASA Astrophysics Data System (ADS)

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.

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

2012-08-01

418

Interdecadal and Interannual Variability of Winter Precipitation in Southeast China  

NASA Astrophysics Data System (ADS)

Interdecadal variability of observed winter (DJF) precipitation in Southeast China (1961 to 2010) is characterized by the first EOF of the three-monthly Standardized Precipitation Index (SPI) subjected to a 9-year running mean, while the differences from the original describe the interannual fluctuations. For interdecadal time scales the dominating spatial modes represent monopole features over Southeast China involving the Arctic Oscillation (AO) and the sea surface temperature (SST) anomalies over western Pacific. Dynamic composite analysis (based on NCEP/NCAR and ERA-40 reanalyzes) reveals the following results: (i) Interdecadal SPI-variations show a trend from a dryer state in the 1970s via an increase during the 1980s towards stabilization of wetter conditions commencing with the 1990s. (ii) In mid-to-high latitudes the weakened southward flow of polar airmasses induces low-level warming over Eurasia due to stronger Arctic Oscillation (AO) by warmer zonal temperature advection. This indicates that the precipitation increase in Southeast is attributed circulation anomalies over mid-to-high latitudes which are related to AO. (iii) The abnormal moisture flux along the southwestern boundary of the abnormal anticyclone over south Japan (and its anomalous south-easterlies) is modulated by the sea surface temperature (SST) anomalies over Western Pacific; a positive (negative) SST anomaly will strengthen (weaken) the warm and moist air flow, leading to abundant (less) precipitation in Southeast China. This demonstrates the collaborative effect of AO and SST anomalies in determining the nonlinear trend observed in winter precipitation over Southeast China. For interannual time scales the dominating spatial pattern also represents monopole patterns. Composite analysis (with resampling test) of the associated circulation anomalies reveals the following results: (i) The wet (dry) winter is a result of the strengthened (weakened) northward warm moist air over east coast of China, which is caused by the weakened (strengthened) East Asian Winter Monsoon (EAWM) due to weakening (strengthening) of Siberia High (SH) and eastward (westward) extending of East Asian Trough (EAT). (ii) The effects of El Nio and sea surface temperature (SST) anomalies over South China Sea (SCS) on rainfall in Southeast China are independent. El Nio years, the anomalous anticyclone (cyclone) over Philippines leads to positive (negative) anomalies of rainfall over South China, while in years with the anomalous positive (negative) SST over SCS (non-ENSO), more (less) water vapor is conveyed to Southeast China, thereby enhancing (reducing) precipitation over south of the Yangtze River. (iii) Contributions from all impact factors (EAWM, SH, EAT, El Nio events and SST SCS anomalies) do not counteract with one aother to generate the Southeast China winter precipitation variability.

Zhang, L.; Fraedrich, K.; Zhu, X.; Sielmann, F.

2013-12-01

419

Winter Ecology of the Western Burrowing Owl (Athene cunicularia hypugaea) in Southern Texas 1999-2004  

USGS Publications Warehouse

This study examines the winter ecology of the western burrowing owl (Athene cunicularia hypugaea) in five Texas counties surrounding Corpus Christi, in southern Texas. There is a substantial gap in information on the owl's life cycle during migration and non-breeding winter months; almost all previous research on western burrowing owls has been conducted during the breeding season. The western burrowing owl currently is federally threatened in Mexico, federally endangered in Canada, and in the United States is considered a National Bird of Conservation Concern by the U.S. Fish and Wildlife Service. Topics investigated included status, effectiveness of public outreach, roost sites and use of culverts and artificial burrows, roost site fidelity, diet, contaminant burdens, body mass, and ectoparasites. Early ornithological reports and a museum egg set revealed that burrowing owls once bred in southern Texas and were common in winter; however, since the 1950's they have been reported in relatively low numbers and only during winter. In this study, public outreach increased western burrowing owl detections by 68 percent. Owls selected winter roost sites with small-diameter openings, including culverts less than or equal to 16 centimeters and artificial burrows of 15 centimeters, probably because the small diameters deterred mammalian predators. Owls showed strong roost site fidelity; 15 banded birds stayed at the same roost sites within a winter, and 8 returned to the same site the following winter. The winter diet was over 90 percent insects, with crickets the primary prey. Analyses of invertebrate prey and regurgitated pellets showed that residues of all but 3 of 28 carbamate and organophosphate pesticides were detected at least once, but all were below known lethal concentrations. Mean body mass of western burrowing owls was 168 grams and was highest in midwinter. Feather lice were detected in low numbers on a few owls, but no fleas or other ectoparasites were found.

Woodin, Marc C.; Skoruppa, Mary K.; Hickman, Graham C.

2007-01-01

420

Sustainability of winter tourism in a changing climate over Kashmir Himalaya.  

PubMed

Mountain areas are sensitive to climate change. Implications of climate change can be seen in less snow, receding glaciers, increasing temperatures, and decreasing precipitation. Climate change is also a severe threat to snow-related winter sports such as skiing, snowboarding, and cross-country skiing. The change in climate will put further pressure on the sensitive environment of high mountains. Therefore, in this study, an attempt has been made to know the impact of climate change on the snow precipitation, water resources, and winter tourism in the two famous tourist resorts of the Kashmir Valley. Our findings show that winters are getting prolonged with little snow falls on account of climate change. The average minimum and maximum temperatures are showing statistically significant increasing trends for winter months. The precipitation is showing decreasing trends in both the regions. A considerable area in these regions remains under the snow and glacier cover throughout the year especially during the winter and spring seasons. However, time series analysis of LandSat MODIS images using Normalized Difference Snow Index shows a decreasing trend in snow cover in both the regions from past few years. Similarly, the stream discharge, comprising predominantly of snow- and glacier-melt, is showing a statistically significant declining trend despite the melting of these glaciers. The predicted futuristic trends of temperature from Predicting Regional Climates for Impact Studies regional climate model are showing an increase which may enhance snow-melting in the near future posing a serious threat to the sustainability of winter tourism in the region. Hence, it becomes essential to monitor the changes in temperature and snow cover depletion in these basins in order to evaluate their effect on the winter tourism and water resources in the region. PMID:24318957

Dar, Reyaz Ahmad; Rashid, Irfan; Romshoo, Shakil Ahmad; Marazi, Asif

2014-04-01

421

Effect of canopy removal on snowpack quantity and quality, fraser experimental forest, Colorado  

USGS Publications Warehouse

Snowpack peak water equivalent (PWE), ion concentration, content, and spatial distribution of ion load data from spring 1987-1996 in a 1 ha clearcut and adjacent forested plots vegetated by mature Picea engelmannii and Abies lasiocarpa in the Fraser experimental forest (FEF), Colorado are presented. Our objectives were: (1) to see if a forest opening might redistribute snowfall, snowpack moisture, and snowpack chemical content, and (2) to examine the importance of canopy interception on snowpack quantity and chemistry. On an average, the canopy intercepted 36% of snowfall. Interception was correlated with snowfall amount, snowpack PWE beneath the canopy, and air temperature. Canopy removal increased snowpack PWE to >90% cumulative snowfall inputs. Snowpack K-, H-, and NH4+ concentrations on the clearcut were lower and NO3- higher than in the snowpack beneath the forested plots. Cu mulative snowfall K+ input was less than in the clearcut snowpack; H+ inputs were greater in snowfall than in the snowpack of any plot; and inorganic N (NO3- and NH4+) inputs from snowfall to the clearcut were greater than to the forested plots. Processes accounting for the differences between snowfall inputs and snowpack ion content were leaching of organic debris in the snowpack, differential elution of the snowpack, and canopy retention. There were significant trends by year in snowpack ion content at PWE without similar trends in snowfall inputs. This finding coupled with snowpack ion elution bring into question the use of snowpack chemistry as an indicator of winter atmospheric inputs in short-term studies. ?? 2001 Elsevier Science B.V.

Stottlemyer, R.; Troendle, C.A.

2001-01-01

422

26 IAnewsletter Vol 9 No 4 Winter 2006IAnewsletter Vol 9 No 4 Winter 2006IAnewsletter http://iac.dtic.mil/iatac Countering DDoS Attacks  

E-print Network

26 IAnewsletter Vol 9 No 4 Winter 2006IAnewsletter Vol 9 No 4 Winter 2006IAnewsletter http://iac.dtic. #12;IAnewsletter Vol 9 No 4 Winter 2006IAnewsletter Vol 9 No 4 Winter 2006IAnewsletter http://iac.dtic

Stavrou, Angelos

423

UCSF Bioengineering Course Listing Winter 2012 Schedule Winter Quarter: January 9 March 23, 2012  

E-print Network

UCSF Bioengineering Course Listing Winter 2012 Schedule Winter Quarter: January 9 ­ March 23, 2012 Systems BioE 241 Magnetic Resonance Spectroscopy BioE 242 Principles of Tissue Engineering BioE 297 (270:30-5 Parnassus Nursing N-217 Parnassus Nursing N-217 A. Wynshaw-Boris wynshawBorisT@peds.ucsf.edu C. Vaisse and A

Healy, Kevin Edward

424

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

Microsoft Academic Search

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

Pamela A. Harris; Phillip W. Stahlman

1996-01-01

425

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

Microsoft Academic Search

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

CHUN-YEN CHANG; EDGAR CHAMBERS

426

Development of hard white winter wheats for a hard red winter wheat region  

Microsoft Academic Search

Hard white winter wheat (HWWW) occupies a very limited area of the USA, but its purported advantages suggest that its production in the major hard red winter wheat (HRWW) region may be feasible. Objectives of our investigations were to develop experimental HWWW lines that combined desirable attributes-grain yield, functional grain quality, and resistance to preharvest sprouting-in single genotypes for comparison

M. P. Upadhyay; G. M. Paulsen; E. G. Heyne; R. G. Sears; R. C. Hoseney

1984-01-01

427

A Comparison of Great Lakes Winter Severity and Ice Cover Winter 1990 vs. the Historical Record  

E-print Network

A Comparison of Great Lakes Winter Severity and Ice Cover Winter 1990 vs. the Historical Record R and air temperature stations listed in Table 1 and Table 2 Ice Cover and the Great Lakes - St. Lawrence temperatures - . resulted in below-normal ice covers on the southern portion of the Great Lakes. - - The St

428

Prairie Winter Play Patterns: (b) Winter and Play. Research Project 10.  

ERIC Educational Resources Information Center

This guidebook provides an empirically-based set of planning and design guidelines for the construction of winter play facilities for Canadian youth residing in locations where outdoor play in winter is curtailed for approximately 4 months of the year. Information used in developing the guidelines was derived from field observations, a literature

Thomsen, Charles H.; Borowiecka, Alexandra

429

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

E-print Network

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 technology widely used by plant breeding programs around the world to supplement and enhance field

Maxwell, Bruce D.

430

Can protein levels be economically increased?  

Technology Transfer Automated Retrieval System (TEKTRAN)

One result from the 2010 hard red winter wheat harvest was an increase of discussions on protein values across the southern great plains. The crop garnered relatively low protein values for several reasons, many of which were directly related to the weather patterns and environmental conditions. T...

431

Evolution of microwave limb sounder ozone and the polar vortex during winter  

NASA Technical Reports Server (NTRS)

The evolution of polar ozone observed by the Upper Atmosphere Research Satellite (UARS) Microwave Limb Sounder (MLS) is described for the northern hemisphere (NH) winters of 1991/1992, 1992/1993, and 1993/1994 and the southern hemisphere (SH) winters of 1992 and 1993. Imterannual and interhemispheric variability in polar ozone evolution are closely related to differences in the polar vortex and to the frequency, duration and strength of stratospheric sudden warmings. Ozone in the midstratospheric vortices increases during the winter, with largest increases associated with stratospheric warmings and a much larger increase in the NH than in the SH. A smaller NH increase was observed in 1993/1994, when the middle stratospheric vortex was stronger. During strong stratospheric warmings in the NH, the upper stratospheric vortex may be so much eroded that it presents little barrier to poleward transport; in contrast, the SH vortex remains strong throughout the stratosphere during wintertime warmings, and ozone increases only below the mixing ratio peak, due to enhanced diabatic descent. Ozone mixing ratios decrease rapidly in the lower stratosphere in both SH late winters, as expected from chemical destruction due to enhanced reactive chlorine. The interplay between dynamics and chemistry is more complex in the NH lower stratosphere and interannual variability is greater. Evidence has previously been shown for chemical ozone destruction in the 1991/1992 and 1992/1993 winters. We show here evidence suggesting some chemical destruction in late February and early March 1994. In the NH late winter lower stratosphere the pattern of high-ozone values (typical of the vortex) seen in mid-latitudes is related to the strength of the lower-stratospheric vortex, with the largest areal extent of high ozone outside the vortex in 1994, when the lower stratospheric vortex is relatively weak, and the least extent in 1993 when the lower stratospheric vortex is strongest.

Manney, G. L.; Froidevaux, L.; Waters, J. W.; Zurek, R. W.

1995-01-01

432

Patterns of leaf morphology and leaf N content in relation to winter temperatures in three evergreen tree species  

NASA Astrophysics Data System (ADS)

The competitive equilibrium between deciduous and perennial species in a new scenario of climate change may depend closely on the productivity of leaves along the different seasons of the year and on the morphological and chemical adaptations required for leaf survival during the different seasons. The aim of the present work was to analyze such adaptations in the leaves of three evergreen species ( Quercus ilex, Q. suber and Pinus pinaster) and their responses to between-site differences in the intensity of winter harshness. We explore the hypothesis that the harshness of winter would contribute to enhancing the leaf traits that allow them to persist under conditions of stress. The results revealed that as winter harshness increases a decrease in leaf size occurs in all three species, together with an increase in the content of nitrogen per unit leaf area and a greater leaf mass per unit area, which seems to be achieved only through increased thickness, with no associated changes in density. P. pinaster was the species with the most intense response to the harshening of winter conditions, undergoing a more marked thickening of its needles than the two Quercus species. Our findings thus suggest that lower winter temperatures involve an increase in the cost of leaf production of evergreen species, which must be taken into account in the estimation of the final cost and benefit balance of evergreens. Such cost increases would be more pronounced for those species that, like P. pinaster, show a stronger response to the winter cold.

Mediavilla, Sonia; Gallardo-Lpez, Victoria; Gonzlez-Zurdo, Patricia; Escudero, Alfonso

2012-09-01

433

Patterns of leaf morphology and leaf N content in relation to winter temperatures in three evergreen tree species.  

PubMed

The competitive equilibrium between deciduous and perennial species in a new scenario of climate change may depend closely on the productivity of leaves along the different seasons of the year and on the morphological and chemical adaptations required for leaf survival during the different seasons. The aim of the present work was to analyze such adaptations in the leaves of three evergreen species (Quercus ilex, Q. suber and Pinus pinaster) and their responses to between-site differences in the intensity of winter harshness. We explore the hypothesis that the harshness of winter would contribute to enhancing the leaf traits that allow them to persist under conditions of stress. The results revealed that as winter harshness increases a decrease in leaf size occurs in all three species, together with an increase in the content of nitrogen per unit leaf area and a greater leaf mass per unit area, which seems to be achieved only through increased thickness, with no associated changes in density. P. pinaster was the species with the most intense response to the harshening of winter conditions, undergoing a more marked thickening of its needles than the two Quercus species. Our findings thus suggest that lower winter temperatures involve an increase in the cost of leaf production of evergreen species, which must be taken into account in the estimation of the final cost and benefit balance of evergreens. Such cost increases would be more pronounced for those species that, like P. pinaster, show a stronger response to the winter cold. PMID:21969112

Mediavilla, Sonia; Gallardo-Lpez, Victoria; Gonzlez-Zurdo, Patricia; Escudero, Alfonso

2012-09-01

434

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

USGS Publications Warehouse

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 fo