Note: This page contains sample records for the topic winter cold front from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: November 12, 2013.
1

Cold Front Characteristics  

NSDL National Science Digital Library

In this activity, students will study animations of several atmospheric variables (air temperature, dew point, solar radiation, rainfall, and wind) to investigate the characteristics of weather produced by a cold front passage. Working in small groups, they will view animations from two different cases, identify patterns and changes, and answer questions about what they see. Links to a student worksheet, to the animations, and to viewing software are provided.

2

Cold fronts in galaxy clusters  

NASA Astrophysics Data System (ADS)

Context. Cold fronts have been observed in several galaxy clusters. Understanding their nature and origin is extremely important for investigating the internal dynamics of clusters. Aims: To gain insight into the nature of these features, we carry out a statistical investigation of their occurrence in a sample of galaxy clusters observed with XMM-Newton and correlate this occurrence with different cluster properties. Methods: We selected a sample of 45 clusters starting from the B55 flux limited sample (Edge et al. 1990, MNRAS, 245, 559) and performed a systematic search for cold fronts. Results: We find that a large fraction of clusters host at least one cold front. Cold fronts are easily detected in all systems that are manifestly undergoing a merger event in the plane of the sky, while the presence of these features in the remaining clusters is related to a steep entropy gradient, in agreement with theoretical expectations. Assuming that cold fronts in cool core clusters are triggered by minor merger events, we estimate a minimum of 1/3 merging events per halo per Gyr. Appendix is only available in electronic form at http://www.aanda.org

Ghizzardi, S.; Rossetti, M.; Molendi, S.

2010-06-01

3

Mesoscale observations of surface fronts and low pressure centres in Canadian East Coast winter storms  

Microsoft Academic Search

The movements of surface cold and warm fronts and low pressure centres have been observed in several Atlantic Canada winter storms. Statistical aspects of the ‘well-defined’ surface fronts (7 warm and 6 cold) are presented. Surface wind direction change was considered as the best indicator of the boundaries of the front; frontal zone widths ranged from 23 to 144 km.

Peter A. Taylor; James R. Salmon; Ronald E. Stewart

1993-01-01

4

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 11.69°C, non-woven + buried improve the 10.09°C. D900 no glue cotton + enhanced membrane covering the grape surface <=-5°C 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 1.57°C, the underground at 30 cm temperature has increased 1.08°C, 60cm, underground buried than the processing temperature has increased 1.54°C, 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

5

Compare and contrast warm and cold fronts  

NSDL National Science Digital Library

This pair of Earth science animations show students what happens at cold and warm fronts as clouds are formed by the interaction of warm air and cool air. The cool front animation depicts cumulonimbus clouds forming as a cold front moves into a region of warm air and forces the warm air to rise. In contrast, the warm front animation shows how warm air, moving over cold air, causes a progression of nimbostratus to cirrus clouds to form. Movie controls allow students to repeat, pause, or step through the animations, which can give students more time to analyze the images. Copyright 2005 Eisenhower National Clearinghouse

Education, Terc. C.; Littell, Mcdougal

2003-01-01

6

Compare and Contrast Warm and Cold Fronts  

NSDL National Science Digital Library

In weather, fronts are defined as the boundaries between different air masses. Depending on the direction of movement and the characteristics of the air involved, different types of fronts form. This visualization shows the movement of warm and cold fronts as well as the characteristic clouds that are generated by each. A background essay and discussion questions are included.

2011-02-18

7

Mesoscale observations of surface fronts and low pressure centres in Canadian East Coast winter storms  

NASA Astrophysics Data System (ADS)

The movements of surface cold and warm fronts and low pressure centres have been observed in several Atlantic Canada winter storms. Statistical aspects of the ‘well-defined’ surface fronts (7 warm and 6 cold) are presented. Surface wind direction change was considered as the best indicator of the boundaries of the front; frontal zone widths ranged from 23 to 144 km. Average values of wind shifts were 107° for the cold fronts and 85° for warm fronts. Several case studies are presented, based primarily on surface MesoNet data (near Halifax, Nova Scotia and on Sable Island). In two of the cold fronts, there was a two-stage surface structure and rapid evolution as the front passed over the MesoNet. In some cases, both warm and cold, the wind shift and temperature change were coincident while in others they were not. In particular we observed that wind shifts often started 20 30 min ahead of the start of a temperature decrease in these cold frontal passages. A possible mechanism for this is discussed. We found little or no evidence of along-front structure in our data although other investigators have found considerable along-front variation on scales of 0(10 km). Observations of the passage of one low pressure centre are presented. In a second case, surface temperature changes indicated an apparent low pressure centre passage through the Sable Island MesoNet but closer inspection provides an alternative interpretation.

Taylor, Peter A.; Salmon, James R.; Stewart, Ronald E.

1993-03-01

8

Shocks and cold fronts in galaxy clusters  

NASA Astrophysics Data System (ADS)

The currently operating X-ray imaging observatories provide us with an exquisitely detailed view of the Megaparsec-scale plasma atmospheres in nearby galaxy clusters. At z<0.05, the Chandra's 1 angular resolution corresponds to linear resolution of less than a kiloparsec, which is smaller than some interesting linear scales in the intracluster plasma. This enables us to study the previously unseen hydrodynamic phenomena in clusters: classic bow shocks driven by the infalling subclusters, and the unanticipated “cold fronts,” or sharp contact discontinuities between regions of gas with different entropies. The ubiquitous cold fronts are found in mergers as well as around the central density peaks in “relaxed” clusters. They are caused by motion of cool, dense gas clouds in the ambient higher-entropy gas. These clouds are either remnants of the infalling subclusters, or the displaced gas from the cluster's own cool cores. Both shock fronts and cold fronts provide novel tools to study the intracluster plasma on microscopic and cluster-wide scales, where the dark matter gravity, thermal pressure, magnetic fields, and ultrarelativistic particles are at play. In particular, these discontinuities provide the only way to measure the gas bulk velocities in the plane of the sky. The observed temperature jumps at cold fronts require that thermal conduction across the fronts is strongly suppressed. Furthermore, the width of the density jump in the best-studied cold front is smaller than the Coulomb mean free path for the plasma particles. These findings show that transport processes in the intracluster plasma can easily be suppressed. Cold fronts also appear less prone to hydrodynamic instabilities than expected, hinting at the formation of a parallel magnetic field layer via magnetic draping. This may make it difficult to mix different gas phases during a merger. A sharp electron temperature jump across the best-studied shock front has shown that the electron proton equilibration timescale is much shorter than the collisional timescale; a faster mechanism has to be present. To our knowledge, this test is the first of its kind for any astrophysical plasma. We attempt a systematic review of these and other results obtained so far (experimental and numerical), and mention some avenues for further studies.

Markevitch, Maxim; Vikhlinin, Alexey

2007-05-01

9

Interactions among the winter monsoon, ocean eddy and ocean thermal front in the South China Sea  

NASA Astrophysics Data System (ADS)

Sea surface temperature (SST) in boreal winter shows a robust feature of ocean front west of Luzon Island where a cyclonic ocean eddy is associated with the winter northeast monsoon. Our analyses further show that cold (warm) water is located in the northwest (southeast) part of the Luzon eddy due to ocean advection, forming the west Luzon front. The results suggest a novel mechanism of the positive feedback among the winter monsoon, ocean eddy and ocean front over the South China Sea. A strong positive wind stress curl associated with the winter monsoon and mountainous islands produces the Luzon eddy. With eddy heat advection, the Luzon eddy is accompanied by negative (positive) SST anomalies in the northwest (southwest) part of the eddy, inducing the west Luzon thermal front. The SST anomalies can further force an anomalous wind pattern that converges onto the positive SST anomalies and diverges from the negative SST anomalies. The anomalous wind distribution in turn enhances the positive wind stress curl west of Luzon Island.

Wang, Guihua; Li, Jiaxun; Wang, Chunzai; Yan, Yunwei

10

Cold Front Cloud Morphometry: a Climatological Assessment Using Satellite Imagery  

Microsoft Academic Search

This research focused upon cold front cloud bands (CFCBs) as they appear on weather observational satellite imagery. Statistical relationships were established between the shape and configuration (morphometry) of the CFCBs and the characteristics of maritime tropical (mT) and continental polar (cP) air masses which meet to form the cold front. An electronic graphics calculator was used to measure CFCBs from

Louis Michael Trapasso

1980-01-01

11

Does cold winter weather produce depressive symptoms?  

NASA Astrophysics Data System (ADS)

To examine whether harsh winter weather is associated with depressive symptoms, 45 healthy subjects from Minnesota were compared to 42 subjects from California near the end of the winter season. No differences in the prevalence of depressive symptoms were found between the two groups.

Garvey, Michael J.; Goodes, Mike; Furlong, Candy; Tollefson, Gary D.

1988-06-01

12

Effects of cold fronts on MODIS-derived sensible and latent heat fluxes in Itumbiara reservoir (Central Brazil)  

NASA Astrophysics Data System (ADS)

In this work we investigate the cold front passage effects on sensible and latent heat flux in a tropical hydroelectric reservoir. The study area, Itumbiara reservoir (Goiás State/Brazil) at the beginning of the austral winter, is characterized by the presence of a weak thermal stratification and the passage of several cold fronts from higher latitudes of South America. Sensible and latent heat fluxes were estimated considering the atmospheric boundary layer stability. In situ and MODIS water surface temperature data were used to adjust the coefficients for momentum and heat exchanges between water and atmosphere and spatialize the sensible and latent heat fluxes. The results showed that during a cold front event the sensible heat flux can be up to five times greater than the flux observed before. The latent heat flux tends to decrease during the cold front but increase again after the passage. The highest values of heat loss were observed at littoral zone and some Reservoir's embayment. The heat loss intensification can be separated in two moments: first, during the cold front passage, when the wind speed increases and the air temperature decreases; second, after the cold front passage, with air humidity decreasing. This can be considered a key process to understanding the heat loss in the Itumbiara reservoir.

Curtarelli, Marcelo; Alcântara, Enner; Rennó, Camilo; Stech, José

2013-11-01

13

Cold Fronts Research Programme: Progress, Future Plans, and Research Directions.  

NASA Astrophysics Data System (ADS)

Following the analysis of data collected during Phases land II of the Cold Fronts Research Programme (CFRP) a conceptual model for the Australian summertime "cool change" has been proposed. The model provides a focus and a framework for the design of Phase III.The model is based on data gathered from a mesoscale network centered on Mount Gambier, South Australia, and includes the coastal waters to the west and relatively flat terrain to the east. The first objective of Phase III is to generalize the model so that it is applicable to the ocean waters to the far west of Mount Gambier and to the more rugged terrain farther to the east in the vicinity of Melbourne, Victoria. The remaining objectives concentrate on resolving unsatisfactory aspects of the model such as the evolution of convective lines and the relationship between the surface cold front and the upper-tropospheric cold pool and its associated jet stream.The integrated nature of the Cold Fronts Research Programme has meant that it has stimulated a wide range of research activities that extend beyond the field observations. The associated investigations include climatological, theoretical, and numerical modeling studies.

Ryan, B. F.; Wilson, K. J.; Garratt, J. R.; Smith, R. K.

1985-09-01

14

The discharge front structure in coastal zone of the Laptev Sea in winter season  

Microsoft Academic Search

In the Arctic region the discharge front is poor studied phenomenon, especially in cold season. We investigated thermohaline structure in the south-eastern part of the Laptev Sea (the Buor-Khaya Bay) where front has been forming under the ice cover. It is identified by strong horizontal temperature and salinity gradients. Front location and its dimension are under the influence of the

Nina Savelieva; Anatoly Salyuk

2010-01-01

15

Models of warm and cold regimes of the winter stratosphere  

NASA Astrophysics Data System (ADS)

Research of fields of geopotential height, temperature, zonal and meridional wind in stratosphere was carried out using the Met Office data for winter seasons from 1991/1992 to 2006-2007. The above analyzes shows that change within season thermodynamic values at high latitudes during the winter is higher than seasonal or longitudinal change. Hence the average models of the cold periods of high latitudes and average monthly values have a limited applicability. In 1982 International Standard Organization (ISO) also acknowledged the necessity for creating of special models for "warm" and "cold" regimes of the high latitude winter stratosphere. Warm and cold stratosphere states were distinguished by the presence or absence of stratospheric warmings of variable intensity exceeding 10 hPa. Special maps and latitude-longitude cuts of mean values and mean square deviations of the geopotential height, temperature, zonal and meridional wind have been created for these regimes. Models of "warm" and "cold" regimes also included zonal harmonics with wave numbers 1 and 2 for all observed meteorological fields

Guryanov, Vladimir

16

An N-shape thermal front in the western South Yellow Sea in winter  

Microsoft Academic Search

An N-shape thermal front in the western South Yellow Sea (YS) in winter was detected using Advanced Very High Resolution Radiation\\u000a (AVHRR) Sea Surface Temperature data and in-situ observations with a merged front-detecting method. The front, which exists\\u000a from late October through early March, consists of western and eastern wings extending roughly along the northeast-southwest\\u000a isobaths with a southeastward middle

Fan Wang; Chuanyu Liu

2009-01-01

17

On the water thermal response to the passage of cold fronts: initial results for Itumbiara reservoir (Brazil)  

NASA Astrophysics Data System (ADS)

The passage of meteorological systems such as cold fronts or convergence zones over reservoirs can cause significant modifications in several aquatic variables. Cold fronts coming from higher latitudes and reaching the Southeastern Brazilian territory modify the mean wind field and have important impact over physical, chemical and biological processes that act in the hydroelectric reservoirs. The mean period of cold front passages along the Southeastern Brazilian coast is 6 days during the winter and between 11 and 14 days in the summer. Most of these fronts also affect the hinterland of São Paulo, Minas Gerais and Goiás states. The objective of this work is to analyze the influence of cold front passages in the thermal stratification and water quality of the Itumbiara hydroelectric reservoir which is located in Minas Gerais and Goiás. The characterization of cold front passages over the study area was done through the analysis of GOES satellite images. The analyzed data set includes time series of meteorological (wind direction and intensity, short-wave radiation, air temperature, relative humidity, atmospheric pressure) and water temperature in four depths (5, 12, 20 and 40 m). The data set was acquired in the interior of the reservoir by an autonomous anchored buoy system at a sampling rate of 1 h. The stratification was assessed by non-dimensional parameter analysis. The lake number an indicator of the degree of stability and mixing in the reservoir was used in this analysis. We will show that during the cold front all atmospheric parameters respond and this response are transferred immediately to the water surface. The main effect is observed in the water column, when the heat loss in the surface allows the upwelling events caused by convective cooling due to the erosion of thermal stratification.

Alcântara, E. H.; Bonnet, M. P.; Assireu, A. T.; Stech, J. L.; Novo, E. M. L. M.; Lorenzzetti, J. A.

2010-12-01

18

Cold Fronts with and without Prefrontal Wind Shifts in the Central United States  

Microsoft Academic Search

Time series of cold fronts from stations in the central United States possess incredible variety. For example, time series of some cold fronts exhibit a sharp temperature decrease coincident with a pressure trough and a distinct wind shift. Other time series exhibit a prefrontal trough and wind shift that precedes the temperature decrease associated with the front by several hours.

David M. Schultz

2004-01-01

19

New Perspectives on Intermountain Cyclones and Cold Fronts  

NASA Astrophysics Data System (ADS)

The topography in and around the Intermountain West strongly affects the genesis, migration, and lysis of extratropical cyclones and cold fronts. In this presentation, we summarize new perspectives on Intermountain cyclone and cold-front evolution derived from recent climatological, observational, and modeling studies based on high-density observations and high-resolution reanalyses and numerical simulations. Recent high-resolution reanalyses show that Intermountain cyclone activity is greatest in two distinct regions. The first, which we call the Great Basin cyclone region, extends northeastward from the southern high Sierra to the Great Salt Lake Basin of northwest Utah. The second, which we call the Canyonlands cyclone region, lies over the upper Colorado River Basin of southeast Utah, a lowland region between the mountains and plateaus of central Utah and the Colorado Rockies. Composites of strong Intermountain cyclones generated in cross-Sierra (210-300°) 500-hPa flow show that cyclogenesis is preceeded by the development of the Great Basin Confluence Zone (GBCZ), a regional airstream boundary that extends downstream from the Sierra Nevada. Cyclogenesis occurs along the GBCZ as large-scale ascent develops over the Intermountain West in advance of an approaching upper-level trough. Flow splitting around the high Sierra and the presence of low-level baroclinity along the GBCZ suggest that Intermountain Cyclogenesis might be better conceptualized from a potential vorticity perspective than from traditional quasigeostrophic models of lee cyclogenesis. Surface observations indicate that the frequency of strong cold-frontal passages increases dramatically from the Cascade-Sierra Mountains to northern Utah, suggesting that the Intermountain West is a frequent cold-frontal breeding ground. Two case studies help illustrate the mechanisms contributing to these strong cold-frontal passages. During the 2002 Tax Day Cyclone, strong contraction (i.e., deformation and convergence) along the GBCZ forms an airstream boundary that is initially non-frontal, but becomes the locus for surface frontogenesis as it collects and concentrates baroclinity from the northern Great Basin. During the 25 March 2006 event, a highly mobile frontal system that moves discretely across the Sierra-Cascade Mountains and western Nevada and develops rapidly over eastern Nevada. Numerical sensitivity studies indicate that the the interaction of southwesterly pre-frontal flow with the formidable southern High Sierra produces a leeward orographic warm anomaly that enhances the cross-front temperature contrast.

Steenburgh, W. J.; West, G.; Neuman, C.; Shafer, J.; Jeglum, M.; Bosart, L. F.; Lee, T.

2011-12-01

20

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 45°23? 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

21

Dust storms generated by mesoscale cold fronts in the Tarim Basin, Northwest China  

Microsoft Academic Search

By the numerical experiments, we clarify the regional wind systems that generate dust storms in the Tarim basin, Northwest China. In the basin, dust storms are generated by a mesoscale cold wind system induced by a synoptic-scale cold air mass behind a cold front. The intruding course of the mesoscale cold wind into the basin can be classified into three

Isao Aoki; Yasunori Kurosaki; Ryoichi Osada; Tomonori Sato; Fujio Kimura

2005-01-01

22

Winter habitat preferences for Florida manatees and vulnerability to cold.  

PubMed

To survive cold winter periods most, if not all, Florida manatees rely on warm-water refuges in the southern two-thirds of the Florida peninsula. Most refuges are either warm-water discharges from power plant and natural springs, or passive thermal basins that temporarily trap relatively warm water for a week or more. Strong fidelity to one or more refuges has created four relatively discrete Florida manatee subpopulations. Using statewide winter counts of manatees from 1999 to 2011, we provide the first attempt to quantify the proportion of animals using the three principal refuge types (power plants, springs, and passive thermal basins) statewide and for each subpopulation. Statewide across all years, 48.5% of all manatees were counted at power plant outfalls, 17.5% at natural springs, and 34.9 % at passive thermal basins or sites with no known warm-water features. Atlantic Coast and Southwest Florida subpopulations comprised 82.2% of all manatees counted (45.6% and 36.6%, respectively) with each subpopulation relying principally on power plants (66.6% and 47.4%, respectively). The upper St. Johns River and Northwest Florida subpopulations comprised 17.8% of all manatees counted with almost all animals relying entirely on springs (99.2% and 88.6% of those subpopulations, respectively). A record high count of 5,076 manatees in January 2010 revealed minimum sizes for the four subpopulations of: 230 manatees in the upper St. Johns River; 2,548 on the Atlantic Coast; 645 in Northwest Florida; and 1,774 in Southwest Florida. Based on a comparison of carcass recovery locations for 713 manatees killed by cold stress between 1999 and 2011 and the distribution of known refuges, it appears that springs offer manatees the best protection against cold stress. Long-term survival of Florida manatees will require improved efforts to enhance and protect manatee access to and use of warm-water springs as power plant outfalls are shut down. PMID:23527063

Laist, David W; Taylor, Cynthia; Reynolds, John E

2013-03-20

23

The discharge front structure in coastal zone of the Laptev Sea in winter season  

NASA Astrophysics Data System (ADS)

In the Arctic region the discharge front is poor studied phenomenon, especially in cold season. We investigated thermohaline structure in the south-eastern part of the Laptev Sea (the Buor-Khaya Bay) where front has been forming under the ice cover. It is identified by strong horizontal temperature and salinity gradients. Front location and its dimension are under the influence of the Lena River discharge. The front dynamics resulted in specifics of vertical thermohaline structure, which is characterized by baroclinic and thermoclinic constituents. In a short distance from the river mouth the front is baroclinic (isotherms and isohalines remain parallel to each other). Another type of front (thermoclinic) is formed at the periphery of the front (isohalines intersect isotherms at an angle of up to 90°). The first mechanism of thermoclinicity is isopycnic convergence of river water in lower horizons because of its cooling near the ice. The second mechanism works at the periphery of the front, where horizontal stratification is weaken, and frontal convergence is resulted in isopycnic intrusions of cold water under the relatively warm fresh water. The intrusion's cross section in the Bay made about 50-85 km and thickness varied from 3-5 up to 15m depending on the Lena River discharge. The temperature of intrusions is lower than at bottom water. The interleaving cold and warm freshened water inside the intrusion is a result of double diffusion process. Water of the intrusion is enriched with dissolved oxygen and facilitates to ventilation of water in the coastal zone under the ice. The calculated heat content of bottom water testifies about its origin from the outer shelf of the Laptev Sea while the T-S characteristics of intrusion is close connected to the inner shelf.

Savelieva, Nina; Salyuk, Anatoly

2010-05-01

24

Cold winter temperatures condition the egg-hatching dynamics of a grape disease vector  

NASA Astrophysics Data System (ADS)

The leafhopper Scaphoideus titanus is the vector of a major phytoplasma grapevine disease, Flavescence dorée. The vector’s distribution is in Eastern and Northern Europe, and its population dynamics varies as a function of vineyard latitude. We tested the hypothesis that hatching dynamics are cued by cold temperatures observed in winter. We exposed eggs from a natural population to simulated “cold” and “mild” winters and varied the exposure time at 5 °C from 0 to 63 days. We show that temperature cooling mainly affected the onset of hatching and is negatively correlated to the cold time exposure. The majority of hatchings occurred more quickly in cold rather than in mild winter simulated conditions, but there was no significant difference between the duration of hatching of eggs whatever the cold time exposure. In agreement with the Northern American origin of the vector, the diapause termination and thus the timing regulation of egg hatching require cold winters.

Chuche, Julien; Thiéry, Denis

2009-07-01

25

Challenging the merger-sloshing cold front paradigm with an observation of A2142  

NASA Astrophysics Data System (ADS)

A2142 is the first cluster in which cold fronts were observed. Two striking surface brightness discontinuities are visible even to an untrained eye in Chandra images and the pressure profiles are almost continuous across them, providing textbook examples of cold fronts. However, A2142 does not fit within the now dominant scenario, that describes cold fronts either as the edges of merging subclusters or as the cool cores ``sloshing'' in the potential well of their host cluster. This ambiguity may be due to an incomplete picture of the dynamical state of A2142 or alternatively to the inadequacy of the current scenario of cold front formation. We propose a 50 ks XMM-Newton observation to characterize the dynamical state of A2142 well enough to resolve this issue.

Rossetti, Mariachiara

2010-10-01

26

MINOR MERGER-INDUCED COLD FRONTS IN ABELL 2142 AND RXJ1720.1+2638  

SciTech Connect

We present evidence for the existence of substructure in the 'relaxed appearing' cold front clusters Abell 2142 and RXJ1720.1+2638. The detection of these substructures was made possible by comprehensive multi-object optical spectroscopy obtained with the Hectospec and DEep Imaging Multi-Object Spectrograph instruments on the 6.5 m MMT and 10 m Keck II telescope, respectively. These observations produced 956 and 400 spectroscopically confirmed cluster members within a projected radius of 3 Mpc from the centers of A2142 and RXJ1720.1+2638, respectively. The substructure manifests itself as local peaks in the spatial distribution of member galaxies and also as regions of localized velocity substructure. For both Abell 2142 and RXJ1720.1+2638, we identify group-scale substructures which, when considering the morphology of the cold fronts and the time since pericentric passage of a perturber estimated from the cold front radii, could plausibly have perturbed the cluster cores and generated the cold fronts observed in Chandra images. The results presented here are consistent with cold fronts being the result of merger activity and with cold fronts in relaxed appearing clusters being due to minor merger activity.

Owers, Matt S.; Couch, Warrick J. [Center for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn, VIC 3122 (Australia); Nulsen, Paul E. J., E-mail: mowers@astro.swin.edu.au [Harvard Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2011-11-10

27

Effects of Stratification on Surface Frontogenesis: Warm and Cold Fronts  

Microsoft Academic Search

The role of the ambient stratification in semigeostrophic surface frontogenesis is examined. Model fronts forming in regions of large static stability 1) are weaker, 2) are tilted more toward the horizontal, and 3) propagate more slowly toward the warm air than fronts forming in regions of small static stability.These results are discussed in light of the differences between warm and

Peter R. Bannon

1984-01-01

28

Cold front induced changes on the Florida panhandle shelf during October 2008  

NASA Astrophysics Data System (ADS)

A significant step transition between seasonally stratified and destratified hydrographic conditions occurred during an October 2008 cruise to the Florida Panhandle Shelf along a cross-shelf transect that was sampled before and after a cold front passed through the area. Meteorological measurements from nearby ocean and land-based stations characterized the event. Cross-shelf continuous Acrobat profiles and discrete CTD stations characterized water column hydrographic patterns, while mid-shelf multicorer and box corer samples characterized sediment texture and nutrients. Water samples collected from selected depths biased toward the sediment interface were analyzed for nutrient content and phytoplankton community composition. Pre-front, the cross-shelf water column exhibited vertical stratification with complex temperature and salinity patterns. A prominent near-bottom chlorophyll a maximum of ˜1.5 ?g L-1 between the 25-35 m isobaths occurred with the 1% light level at ˜18 m depth and a near-bottom nitrate+nitrite (NO3-+NO2-) maximum >3 ?M between the 30-40 m isobaths. HPLC-determined phytoplankton community composition in the near-bottom chlorophyll a maximum consisted of gyroxanthin-containing dinoflagellates (Karenia brevis) and less abundant diatoms, both verified by FlowCAM analysis, mixed with detectable cryptophytes and chlorophytes. Sediment trends based on limited core replicates suggested the sediments were a potential source of nutrients to near-bottom populations of K. brevis and that shell hash could provide abundant pore space for K. brevis incursions. Between the 40-50 m isobaths, diatoms, cryptophytes and chlorophytes dominated near-bottom, gyroxanthin-containing dinoflagellates and prasinophytes occurred throughout the water column, and cyanophytes dominated near-surface. Post-front, the cross-shelf water column exhibited destratification with temperature and salinity increasing offshore. A chlorophyll a maximum of ˜0.75 ?g Chl a L-1 left the sediment between 25-35 m isobaths and extended offshore especially in the lower water column with the 1% light level at ˜15 m depth and NO3-+NO2- concentrations ˜2 ?M to the 60 m isobath. HPLC-determined phytoplankton community composition of the offshore plume retained the signature of gyroxanthin-containing dinoflagellates and chlorophytes. Between the 30-50 m isobaths, prasinophytes increased in the lower water column, while cyanophytes increased at all depths across the shelf. The observed step transition from stratification to destratification on the Florida Panhandle Shelf contributed to altered phytoplankton community patterns in response to predominant downwelling favorable winds. Pre-front, K. brevis cells were broadly distributed cross-shelf, but concentrated near-bottom between the 25-35 m isobaths and staged for prolific bloom seeding in response to the upwelling favorable west winds more typical of spring-summer. Post-front, K. brevis cells were mixed throughout the mid-shelf water column and were staged for diffuse bloom seeding in response to either the downwelling or upwelling favorable winds occurring fall-winter. Cyanophytes located predominantly near-surface offshore pre-front, were ubiquitous cross-shelf and more closely associated with K. brevis post-front.

Kamykowski, D.; Pridgen, K. Grabowski; Morrison, J. M.; McCulloch, A. A.; Nyadjro, E. S.; Thomas, C. A.; Sinclair, G. A.

2013-02-01

29

Cold-Active Winter Rye Glucanases with Ice-Binding Capacity12  

PubMed Central

Extracellular pathogenesis-related proteins, including glucanases, are expressed at cold temperatures in winter rye (Secale cereale) and display antifreeze activity. We have characterized recombinant cold-induced glucanases from winter rye to further examine their roles and contributions to cold tolerance. Both basic ?-1,3-glucanases and an acidic ?-1,3;1,4-glucanase were expressed in Escherichia coli, purified, and assayed for their hydrolytic and antifreeze activities in vitro. All were found to be cold active and to retain partial hydrolytic activity at subzero temperatures (e.g. 14%–35% at ?4°C). The two types of glucanases had antifreeze activity as measured by their ability to modify the growth of ice crystals. Structural models for the winter rye ?-1,3-glucanases were developed on which putative ice-binding surfaces (IBSs) were identified. Residues on the putative IBSs were charge conserved for each of the expressed glucanases, with the exception of one ?-1,3-glucanase recovered from nonacclimated winter rye in which a charged amino acid was present on the putative IBS. This protein also had a reduced antifreeze activity relative to the other expressed glucanases. These results support the hypothesis that winter rye glucanases have evolved to inhibit the formation of large, potentially fatal ice crystals, in addition to having enzymatic activity with a potential role in resisting infection by psychrophilic pathogens. Glucanases of winter rye provide an interesting example of protein evolution and adaptation aimed to combat cold and freezing conditions.

Yaish, Mahmoud W.F.; Doxey, Andrew C.; McConkey, Brendan J.; Moffatt, Barbara A.; Griffith, Marilyn

2006-01-01

30

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.

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

1970-01-01

31

Effects of salicylic acid and cold on freezing tolerance in winter wheat leaves  

Microsoft Academic Search

The effects of salicylic acid (SA) (0.01, 0.1 and 1 mM) and cold on freezing tolerance (freezing injury and ice nucleation activity) were investigated in winter wheat (Triticum aestivum cv. Dogu-88) grown under control (20\\/18 °C for 15, 30 and 45-day) and cold (15\\/10 °C for 15-day, 10\\/5 °C for 30-day and 5\\/3 °C for 45-day) conditions. Cold acclimatisation caused

Esen Ta?gín; Ökke? Atící; Barbaros Nalbanto?lu

2003-01-01

32

Chitinase Genes Responsive to Cold Encode Antifreeze Proteins in Winter Cereals1  

PubMed Central

Antifreeze proteins similar to two different chitinases accumulate during cold acclimation in winter rye (Secale cereale). To determine whether these cold-responsive chitinases require post-translational modification to bind to ice, cDNAs coding for two different full-length chitinases were isolated from a cDNA library produced from cold-acclimated winter rye leaves. CHT9 is a 1,193-bp clone that encodes a 31.7-kD class I chitinase and CHT46 is a 998-bp clone that codes for a 24.8-kD class II chitinase. Chitinase-antifreeze proteins purified from the plant were similar in mass to the predicted mature products of CHT9 and CHT46, thus indicating that there was little chemical modification of the amino acid sequences in planta. To confirm these results, the mature sequences of CHT9 and CHT46 were expressed in Escherichia coli and the products of both cDNAs modified the growth of ice. Transcripts of both genes accumulated late in cold acclimation in winter rye. Southern analysis of winter rye genomic DNA indicated the presence of a small gene family homologous to CHT46. In hexaploid wheat, CHT46 homologs mapped to the homeologous group 1 chromosomes and were expressed in response to cold and drought. We conclude that two novel cold-responsive genes encoding chitinases with ice-binding activity may have arisen in winter rye and other cereals through gene duplication.

Yeh, Sansun; Moffatt, Barbara A.; Griffith, Marilyn; Xiong, Fei; Yang, Daniel S.C.; Wiseman, Steven B.; Sarhan, Fathey; Danyluk, Jean; Xue, Yi Qi; Hew, Choy L.; Doherty-Kirby, Amanda; Lajoie, Gilles

2000-01-01

33

The impact of winter cold weather on acute myocardial infarctions in Portugal.  

PubMed

Mortality due to cardiovascular diseases shows a seasonal trend that can be associated with cold weather. Portugal is the European country with the highest excess winter mortality, but nevertheless, the relationship between cold weather and health is yet to be assessed. The main aim of this study is to identify the contribution of cold weather to cardiovascular diseases within Portugal. Poisson regression analysis based on generalized additive models was applied to estimate the influence of a human-biometeorological index (PET) on daily hospitalizations for myocardial infarction. The main results revealed a negative effect of cold weather on acute myocardial infarctions in Portugal. For every degree fall in PET during winter, there was an increase of up to 2.2% (95% CI = 0.9%; 3.3%) in daily hospital admissions. This paper shows the need for public policies that will help minimize or, indeed, prevent exposure to cold. PMID:23410618

Vasconcelos, João; Freire, Elisabete; Almendra, Ricardo; Silva, Giovani L; Santana, Paula

2013-02-11

34

High mortality of Pacific oysters in a cold winter in the North-Frisian Wadden Sea  

NASA Astrophysics Data System (ADS)

Mortality of introduced Pacific oysters ( Crassostrea gigas) was studied in the northern Wadden Sea in response to an ice winter. After a decade of mild winters, in January and February 2010, the first severe winter occurred since the Pacific oysters became dominant on former intertidal blue mussel ( Mytilus edulis) beds in the North-Frisian Wadden Sea. After the ice winter, mortality of Pacific oysters on densely populated beds in the List tidal basin reached about 90%, indicating much higher losses in comparison to former mild winters. At lower densities between the islands of Amrum and Föhr, oysters were less or even not affected. Although Pacific oysters are assumed to be very tolerant to frost, the duration of cold water- and air temperatures accompanied by mechanical stress of the ice burden might have caused the high mortality in the winter 2009/2010 in formerly dense beds.

Büttger, Heike; Nehls, Georg; Witte, Sophia

2011-12-01

35

Autumn growth and cold hardening of winter wheat under simulated climate change  

Microsoft Academic Search

Plant responses to elevated CO2 are governed by temperature, and at low temperatures the beneficial effects of CO2 may be lost. To document the responses of winter cereals grown under cold conditions at northern latitudes, autumn growth of winter wheat exposed to ambient and elevated levels of temperature (+2.5°C), CO2 (+150 µmol mol), and shade (?30%) was studied in open-top

Hans M. Hanslin; Leiv M. Mortensen

2010-01-01

36

The cold tongue in the South China Sea during boreal winter and its interaction with the atmosphere  

Microsoft Academic Search

A distinct cold tongue has recently been noticed in the South China Sea during the winter monsoon, with the cold tongue temperature\\u000a minimum occurring in the January or February. This cold tongue shows significant links with the Maritime Continent’s rainfall\\u000a during the winter period. The cold tongue and its interaction with the Maritime Continent’s weather were studied using Reynolds\\u000a SST

Hamza Varikoden; A. A. Samah; C. A. Babu

2010-01-01

37

Effects of cold front passage on turbulent fluxes over a large inland water  

NASA Astrophysics Data System (ADS)

Turbulent fluxes of sensible and latent heat over a large inland water in southern USA were measured using the eddy covariance method through the year of 2008. In addition, net radiation, air temperatures and relative humidity, and water temperature in different depths were also measured. The specific objective of this study is to examine effects of a cold front passage on the surface energy fluxes. For the typical cold front event selected from April 11 to 14, air temperature decreased by 16°C, while surface temperature only dropped 6°C. Atmospheric vapor pressure decreased by 1.6 kPa, while that in the water-air interface dropped 0.7 kPa. The behavior difference in the water-air interface was caused by the passage of cold, dry air masses immediately behind the cold front. During the cold front event, sensible heat and latent heat flux increased by 171 W m-2 and 284 W m-2, respectively. Linear aggression analysis showed that the sensible heat flux was proportional to the product of wind speed and the temperature gradient of water-air interface, with a correlation coefficient of 0.95. Latent heat flux was proportional to the product of wind speed and vapor pressure difference between the water surface and overlaying atmosphere, with a correlation coefficient of 0.81. Also, the correlations between both fluxes and the wind speed were weak. This result indicated that the strong wind associated with the cold front event contributed to the turbulent mixing, which indirectly enhanced surface energy exchange between the water surface and the atmosphere. The relationship between the water heat storage energy and turbulent fluxes was also examined.

Zhang, Q.; Liu, H.

2011-12-01

38

Orographic low-level clouds of Southeast Asia during the cold surges of the winter monsoon  

NASA Astrophysics Data System (ADS)

This study is an examination of low clouds over Southeast Asia during northern fall and winter using albedo values derived from visible images, cloud-top temperatures from infrared radiation images from the Multi-functional Transport Satellite 1 (MTSAT-1), and rainfall-top height (storm height) from precipitation radar (PR) on the Tropical Rainfall Measuring Mission (TRMM) satellites. To understand the cloud and precipitation activities associated with the winter monsoon cold surges along the eastern coast of the Indochina Peninsula, atmospheric circulation data from the Japanese 25-year reanalysis (JRA-25) were used.The results showed that low clouds were frequently observed in December, January, and February. In October and November, rainfall activity was relatively high, whereas, in northern winter, it was low, although the winter monsoon northeasterly was strong in both cases. The cloud-top height and storm height decreased with the seasonal march from northern fall to winter.Also examined in this study were the temporal variations in cloud activity on shorter time scales than those of the seasonal march. Concurrent with the cold surges along the eastern coast of the Eurasia, clouds varied on synoptic and intraseasonal time scales. The timing of low-cloud formation corresponded to the beginning of the cold surges. However, the low clouds along the eastern coast of the Indochina Peninsula may remain during the weakening phase of the cold surges.

Takahashi, Hiroshi G.

2013-09-01

39

Export of Asian pollution during two cold front episodes of the TRACE-P experiment  

Microsoft Academic Search

Two cold front episodes were sampled during the two flights out of Yokota, Japan, during the Transport and Chemical Evolution Over the Pacific (TRACE-P) experiment during March 2001. The data from these two flights are examined using a mesoscale three-dimensional model. We show how these cyclonic systems have impacted the export of pollution out of the Asian continent. We contrast

C. Mari; M. J. Evans; P. I. Palmer; D. J. Jacob; G. W. Sachse

2004-01-01

40

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.

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

2013-01-01

41

The Interruption of Alpine Foehn by a Cold Front. Part II: Numerical Simulations  

NASA Astrophysics Data System (ADS)

In this work the interaction of Alpine foehn winds with a cold front is investigated. Despite the wealth of studies on south foehn in the region of Innsbruck during the last century not much is known about the dynamics of foehn breakdown. In most cases, the interruption of foehn is connected with a cold front, which approaches the Alps from northerly or northwesterly directions. The resulting change of warm and dry southerly winds to a cold and moist airmass may occur within less than an hour. The objective of this study is to receive a better understanding of the dynamical processes connected with the collision of two airflows from opposing directions in an Alpine valley by means of numerical simulations conducted with the Weather Research and Forecasting (WRF) Model, Version 3.1. For this purpose a foehn event at the Special Observing Period (SOP) of the Mesoscale Alpine Programme (MAP) has been chosen. On 6 November 1999 a cold front impinged on the Alps and caused the breakdown of the foehn flow. The investigations are mainly focused on the Austrian Inn- and Wipp Valley, which has been one of the target areas during the MAP SOP. The results from the mesoscale model are compaired against the large available observational data set, including surface station, radiosonde and lidar measurements. Nested model runs provide the ability to investigate a wide range of temporal and spatial scales. The model is able to capture the blocking of moist air south of the Alps during foehn and the deformation of the cold front by the mountain range north of the Alps. To quantitatively describe the exchange of air masses in a given box near Innsbruck a mass budget calculation has been accomplished. The most prominent feature is a sudden increase of the inflow from the west during the cold front passage. The fine-scale structure of the cold front, which shows the nature of a density current, is determined with an additional one-way nested high-resolution simulation in the Wipp Valley. Futhermore, the sensitivity of the model results on the initial and boundary conditions, which are based on different ECMWF analysis products, is studied. Apart from these tests, it is shown, that the quality of the numerical simulations strongly depends on the type of boundary-layer parametrization used in the model.

Dautz, E.; Gohm, A.

2010-09-01

42

A cold-regulated nucleic acid-binding protein of winter wheat shares a domain with bacterial cold shock proteins.  

PubMed

The molecular mechanisms of cold acclimation are still largely unknown; however, it has been established that overwintering plants such as winter wheat increases freeze tolerance during cold treatments. In prokaryotes, cold shock proteins are induced by temperature downshifts and have been proposed to function as RNA chaperones. A wheat cDNA encoding a putative nucleic acid-binding protein, WCSP1, was isolated and found to be homologous to the predominant CspA of Escherichia coli. The putative WCSP1 protein contains a three-domain structure consisting of an N-terminal cold shock domain with two internal conserved consensus RNA binding domains and an internal glycine-rich region, which is interspersed with three C-terminal CX(2)CX(4)HX(4)C (CCHC) zinc fingers. Each domain has been described independently within several nucleotide-binding proteins. Northern and Western blot analyses showed that WCSP1 mRNA and protein levels steadily increased during cold acclimation, respectively. WCSP1 induction was cold-specific because neither abscisic acid treatment, drought, salinity, nor heat stress induced WCSP1 expression. Nucleotide binding assays determined that WCSP1 binds ssDNA, dsDNA, and RNA homopolymers. The capacity to bind dsDNA was nearly eliminated in a mutant protein lacking C-terminal zinc fingers. Structural and expression similarities to E. coli CspA suggest that WCSP1 may be involved in gene regulation during cold acclimation. PMID:12122010

Karlson, Dale; Nakaminami, Kentaro; Toyomasu, Tomonobu; Imai, Ryozo

2002-07-16

43

Long cold winters give higher stream water dissolved organic carbon (DOC) concentrations during snowmelt  

NASA Astrophysics Data System (ADS)

We show that long cold winters enhanced the stream water dissolved organic carbon (DOC) concentrations during the following spring flood. Using a 15 year stream record from a boreal catchment, we demonstrate that the interannual variation in DOC concentrations during spring flood was related to the discharge, and winter climate. That discharge is important for DOC concentration agrees with previous studies. By controlling for discharge we could detect that the winter climatic conditions during the preceding winter affected the soil water DOC concentrations, which in turn affected the concentrations in the stream. The results from the stream time-series were also supported by a riparian soil frost experiment, which showed that a long period of soil frost promoted high DOC concentrations in the soil water.

Gren, A. Ã.; Haei, M.; Köhler, S.; Bishop, K.; Laudon, H.

2010-06-01

44

The extremely cold 2009-2010 winter and its relationship with the Arctic oscillation  

NASA Astrophysics Data System (ADS)

The Northern-Hemisphere high-latitude continents experienced extremely cold weathers in winter 2009-2010. In the present paper, we show that the cold winter was associated with the activity of the Arctic oscillation (AO), which demonstrated the strongest negative polarity over the past six decades and persisted from December, 2009 to March, 2010. It is found that variations of the surface AO was closely linked to stratospheric polar vortex anomalies, and that the surface AO phases followed downward propagation of stratospheric Northern-Hemisphere Annular mode (NAM) anomalies during the winter. The case of 2009-2010 winter provides us with a typical example that anomalous stratospheric signals can be used to improve skills of long-range weather forecast and intra-seasonal climate prediction in winter time. We also show that the El Niño event, which started developing from May 2009, might contribute the formation of exceptionally negative and persistent AO and stratospheric NAM, particularly over North Pacific and North America.

Wen, Xin-Yu; Hu, Yong-Yun; Liu, Ji-Ping

2013-10-01

45

Winter sports athletes: long-term effects of cold air exposure.  

PubMed

Athletes such as skaters and skiers inhale large volumes of cold air during exercise and shift from nasal to mouth breathing. Endurance athletes, like cross-country skiers, perform at 80% or more of their maximal oxygen consumption and have minute ventilations in excess of 100 l/min. Cold air is always dry, and endurance exercise results in loss of water and heat from the lower respiratory tract. In addition, athletes can be exposed to indoor and outdoor pollutants during the competitive season and during all-year training. Hyperpnoea with cold dry air represents a significant environmental stress to the airways. Winter athletes have a high prevalence of respiratory symptoms and airway hyper-responsiveness to methacholine and hyperpnoea. The acute effects of exercise in cold air are neutrophil influx as demonstrated in lavage fluid and airway epithelial damage as demonstrated by bronchoscopy. Upregulation of pro-inflammatory cytokines has been observed in horses. Chronic endurance training damages the epithelium of the small airways in mice. Airway inflammation has been observed on bronchoscopy of cross-country skiers and in dogs after a 1100-mile endurance race in Alaska. Neutrophilic and lymphocytic inflammation with remodelling is present in bronchial biopsies from skiers. Repeated peripheral airway hyperpnoea with dry air causes inflammation and remodelling in dogs. As it is currently unknown if these airway changes are reversible upon cessation of exposure, preventive measures to diminish exposure of the lower airways to cold air should be instituted by all winter sports athletes. PMID:22267570

Sue-Chu, Malcolm

2012-01-20

46

Cold temperature increases winter fruit removal rate of a bird-dispersed shrub.  

SciTech Connect

Kwit, C., D. J. Levey; C. H. Greenberg, S. F. Pearson, J.P. McCarty, and S. Sargent. Cold temperature increases winter fruit removal rate of a bird-dispersed shrub. Oecologia. 139:30-34. Abstract: We tested the hypothesis that winter removal rates of fruits of wax myrtle, Myrica cerifera, are higher in colder winters. Over a 9-year period, we monitored M. cerifera fruit crops in 13 0.1-ha study plots in South Carolina, U.S.A. Peak ripeness occurred in November, whereas peak removal occurred in the coldest months, December and January. Mean time to fruit removal within study plots was positively correlated with mean winter temperatures, thereby supporting our hypothesis. This result, combined with the generally low availability of winter arthropods, suggests that fruit abundance may play a role in determining winter survivorship and distribution of permanent resident and short-distance migrant birds. From the plant's perspective, it demonstrates inter-annual variation in the temporal component of seed dispersal, with possible consequences for post-dispersal seed and seedling ecology.

Charles Kwit; Douglas J. Levey; Cathryn H. Greenberg; Scott F. Pearson; John P. McCarty; Sarah Sargent

2004-01-10

47

Occurrence of shallow cold flows in the winter atmospheric boundary layer of interior of Alaska  

NASA Astrophysics Data System (ADS)

During winters, the absence of solar radiation combined with clear skies and weak synoptic forcing enables cold pooling in the complex topographic basins of interior Alaska. Under these conditions, shallow, small-scale cold flows originating within, or flowing from, north-facing semi-enclosed basins are able to penetrate the frigid atmospheric boundary layer (ABL) of the open south-facing basins. This paper introduces the Winter Boundary Layer Experiment carried out during three consecutive periods in Fairbanks (2009-2011) and examines observational results illustrating the changes in the mean and turbulent state of the ABL during the occurrence of shallow flows. Observations introduced here demonstrate that during flow penetration, surface layer stratification is destroyed allowing mixing and thermal stabilization of the basin cooling regime. Evidence of upper level ABL thermal turbulence related to shear driven flow is introduced and discussed. Basin-scale turbulent heat fluxes are shown to reach -20 Wm-2 during flow occurrence.

Fochesatto, Gilberto J.; Mayfield, John A.; Starkenburg, Derek P.; Gruber, Matthew A.; Conner, James

2013-10-01

48

Malate metabolism and reactions of oxidoreduction in cold-hardened winter rye (Secale cereale L.) leaves  

Microsoft Academic Search

In cold-hardened leaves (CHL) of winter rye (Secale cereale L.) much higher levels of malate were detected by 13C-NMR than in non-hardened leaves (NHL). As this was not observed previously, malate metabolism of CHL was studied in more detail by bio- chemical assays. The activities of several enzymes of malate metabolism, NADP-malate dehydrogenase, NAD-malate dehydrogenase, phosphoenolpyruvate carboxylase, and NADP-malic enzyme,

Frauke Crecelius; Peter Streb; Jurgen Feierabend

2003-01-01

49

Variability of Near-Ground Ozone Concentrations During Cold Front Passages – a Possible Effect of Tropopause Folding Events  

Microsoft Academic Search

The analysis of surface ozone variability requires besides chemicalstudies the consideration of meteorological conditions and dynamicprocesses. Our research focuses on the mechanisms in connection with coldfront passages. A statistical study and case studies of cold front passageswere carried out at six German ground-based sites during the year 1990.After the passage of cold fronts three typical developments of thenear-ground ozone concentrations

H. Kunz; P. Speth

1997-01-01

50

Fine-scale observations of the structure and evolution of a tornadic cold front  

NASA Astrophysics Data System (ADS)

On 29 November 2011 a strong cold front crossed the UK. An intense, narrow rain band accompanied the front over northern England, along which several small tornadoes developed. The vertical structure of the front was sampled as it approached the UK, using dropsondes and in-situ aircraft measurements, as part of the DIAbatic influences on Mesoscale structures in ExTratropical storms (DIAMET) field campaign. One-minute-resolution data from the Met Office's network of automatic weather stations (AWSs) were used to investigate the structure of the surface front as it crossed the UK. 'Time-to-space' conversion of the AWS data, using a system motion vector estimated from sequences of radar data, permitted a fine-scale analysis of the surface frontal structure and its variation in the along-front direction. On the 28th, operational Unified Model output and aircraft dropsondes showed two separate fronts in the eastern Atlantic Ocean. By the morning of the 29th, dropsondes south of Ireland presented some features consistent with kata (also known as 'split') fronts, with two distinct, but overlapping dry intrusions, each overrunning saturated air below. Each dry intrusion was associated with a local maximum in the cross-front wind component, with a forward-directed, front-relative flow of ~ 5 - 10 m/s. Radar data showed the presence of multiple, narrow rain bands over Ireland and western extremities of the UK early on the 29th, as the front moved within range of the UK radar network. Over Ireland, the merger of at least two separate rain bands was observed. The merged band intensified and accelerated eastwards, leading to a single, intense, bowing line segment over northern England, along which the tornadoes occurred. In contrast, over southern England, no merger occurred, and the frontal zone was characterised by multiple rain bands for the duration of the observation period. The surface data showed markedly different structure in the temperature, wind and pressure fields in these two regions. Observational analyses, derived from the surface and dropsonde data, will be presented, with a particular focus on the observed differences in frontal structure over northern and southern England. Possible reasons for the differences will be discussed. A comparison with available operational model data will also be presented.

Clark, Matt; Rosenberg, Phil; Parker, Doug

2013-04-01

51

Medieval Irish chronicles reveal persistent volcanic forcing of severe winter cold events, 431–1649 CE  

NASA Astrophysics Data System (ADS)

Explosive volcanism resulting in stratospheric injection of sulfate aerosol is a major driver of regional to global climatic variability on interannual and longer timescales. However, much of our knowledge of the climatic impact of volcanism derives from the limited number of eruptions that have occurred in the modern period during which meteorological instrumental records are available. We present a uniquely long historical record of severe short-term cold events from Irish chronicles, 431–1649 CE, and test the association between cold event occurrence and explosive volcanism. Thirty eight (79%) of 48 volcanic events identified in the sulfate deposition record of the Greenland Ice Sheet Project 2 ice-core correspond to 37 (54%) of 69 cold events in this 1219 year period. We show this association to be statistically significant at the 99.7% confidence level, revealing both the consistency of response to explosive volcanism for Ireland’s climatically sensitive Northeast Atlantic location and the large proportional contribution of volcanism to historic cold event frequencies here. Our results expose, moreover, the extent to which volcanism has impacted winter-season climate for the region, and can help to further resolve the complex spatial patterns of Northern Hemisphere winter-season cooling versus warming after major eruptions.

Ludlow, Francis; Stine, Alexander R.; Leahy, Paul; Murphy, Enda; Mayewski, Paul A.; Taylor, David; Killen, James; Baillie, Michael G. L.; Hennessy, Mark; Kiely, Gerard

2013-06-01

52

Simulation of wave damping during a cold front over the muddy Atchafalaya shelf  

NASA Astrophysics Data System (ADS)

The Atchafalaya Shelf off the Louisiana coast in the United States is characterized by fine grained sediments dispersing into the shelf from the lower Atchafalaya River and Wax Lake outlets. Rapid seaward flushing of the sediment-laden river plumes, due to water level set-down during cold front passages forms a fluid mud layer close to the bottom, which effectively dampens the wave energy. In this study, the performance of a phase-averaged spectral wave model was skill assessed based on the wave data recorded close to the southern periphery of the mud zone during several days in March 2009. Separation of wave spectra into sea and swell partitions showed that the wave model overestimated the sea waves generated by northerly wind during the cold front passage. A non-stationary scheme was needed to solve the wave action balance equation to include the wind dynamics during the cold front passages over the study area. A recently developed mud-induced dissipation term was improved by modifying its algorithm for solving the implicit dispersion equation. The modified model became efficient enough to be used for non-stationary calculations. The thickness, density, kinematic viscosity of the mud layer, and its offshore extent were determined by trial and error. The mud-induced energy dissipation term enabled the model to reproduce the energy attenuation of short waves by the fluid mud. A high value of mud viscosity (0.01-0.1 m2/s) was required to obtain good agreement with in situ measurements when the maximum wave height occurred. However, the model using lower values of mud viscosity (0.001-0.01 m2/s) was more successful in reproducing the measured wave spectra from a few hours after the maximum wave activity. The simulation results also showed that presence of fluid mud with high value of mud viscosity hindered the wave growth in shallow water due to suppression of high frequency waves.

Siadatmousavi, Seyed Mostafa; Allahdadi, M. Nabi; Chen, Qin; Jose, F.; Roberts, H. H.

2012-09-01

53

MERGING COLD FRONTS IN THE GALAXY PAIR NGC 7619 AND NGC 7626  

SciTech Connect

We present results from Chandra observations of the galaxy pair NGC 7619 and NGC 7626, the two dominant members of the Pegasus group. The X-ray images show a brightness edge associated with each galaxy, which we identify as merger cold fronts. The edges are sharp, and the axes of symmetry of the edges are roughly antiparallel, suggesting that these galaxies are falling toward one another in the plane of the sky. The detection of merger cold fronts in each of the two dominant member galaxies implies a merging subgroup scenario, since the alternative is that the galaxies are falling into a preexisting {approx}1 keV halo without a dominant galaxy of its own, and such objects are not observed. We estimate the three-dimensional velocities from the cold fronts and, using the observed radial velocities of the galaxies, show that the velocity vectors are indeed most likely close to the plane of the sky, with a relative velocity of {approx}1190 km s{sup -1}. The relative velocity is consistent with what is expected from the infall of two roughly equal mass subgroups whose total viral mass equals that of the Pegasus group. We conclude that the Pegasus cluster is most likely currently forming from a major merger of two subgroups, dominated by NGC 7619 and NGC 7626. NGC 7626 contains a strong radio source, consisting of a core with two symmetric jets, and radio lobes. Although we find no associated structure in the X-ray surface brightness map, the temperature map reveals a clump of cool gas just outside the southern lobe, presumably entrained by the lobe, and possibly an extension of cooler gas into the lobe itself. The jet axis is parallel with the projected direction of motion of NGC 7626 (inferred from the symmetry axis of the merger cold front), and the southern leading jet is foreshortened as compared to the northern trailing one, possibly due to the additional ram pressure encountered by the forward jet.

Randall, S. W.; Jones, C.; Kraft, R.; Forman, W. R.; O'Sullivan, E. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States)

2009-05-10

54

Winter storm impacts on chenier plain coast of southwestern Louisiana  

Microsoft Academic Search

Stormy conditions associated with periodic winter cold front passages are closely related to transport of suspended sediment to the continental shelf, coastal erosion, and coastal progradation along shoreline sectors where abundant fine-grained sediments are stored on the inner shelf. Cold front passages occur between October and April on 3 to 5-day cycles. Their typical northwest to southeast direction of approach,

H. H. Roberts; O. K. Huh; S. A. Hsue; L. J. Jr. Rouse; D. A. Rickman

1989-01-01

55

Carbon dioxide variability during cold front passages and fair weather days at a forested mountaintop site  

NASA Astrophysics Data System (ADS)

This study describes temporal carbon dioxide (CO2) changes at a new meteorological site on a mountaintop in the Virginia Blue Ridge Mountains during the first year of measurements. Continental mountaintop locations are increasingly being used for CO2 monitoring, and investigations are needed to better understand measurements made at these locations. We focus on CO2 mixing ratio changes on days with cold front passages and on fair weather days. Changes in CO2 mixing ratios are largest during cold front passages outside the growing season and on clear, fair weather days in the growing season. 67% (60%) of the frontal passages during the non-growing (growing) season have larger postfrontal than prefrontal CO2 mixing ratios. The increase in CO2 mixing ratio around the frontal passage is short-lived and coincides with changes in CO and O3. The CO2 increase can therefore be used as an additional criterion to determine the timing of frontal passages at the mountaintop station. The CO2 increase can be explained by an accumulation of trace gases along frontal boundaries. The magnitude and duration of the CO2 increase is affected by the wind speed and direction that determine the source region of the postfrontal air. Southward-moving fronts result in the largest prolonged period of elevated CO2, consistent with the postfrontal advection of air from the Northeastern United States where anthropogenic contributions are relatively large compared to other areas in the footprint of the mountaintop station. These anthropogenic contributions to the CO2 changes are confirmed through concurrent CO measurements and output from NOAA’s CarbonTracker model.

Lee, Temple R.; de Wekker, Stephan F. J.; Andrews, Arlyn E.; Kofler, Jonathan; Williams, Jonathan

2012-01-01

56

Detecting spring after a long winter: coma or slow vigilance in cold, hypoxic turtles?  

PubMed

Many freshwater turtle species can spend the winter submerged in ice-covered lakes by lowering their metabolism, and it has been proposed that such severe metabolic depression render these turtles comatose. This raises the question of how they can detect the arrival of spring and respond in a sensible way to sensory information during hibernation. Using evoked potentials from cold or hypoxic turtles exposed to vibration and light, we show that hibernating turtles maintain neural responsiveness to light stimuli during prolonged hypoxia. Furthermore, turtles held under hibernation conditions for 14 days increase their activity when exposed to light or elevated temperatures, but not to vibration or increased oxygen. It is concluded that hibernating turtles are not comatose, but remain vigilant during overwintering in cold hypoxia, allowing them to respond to the coming of spring and to adjust their behaviour to specific sensory inputs. PMID:24108677

Madsen, Jesper G; Wang, Tobias; Beedholm, Kristian; Madsen, Peter T

2013-10-09

57

Geographic variation in Bar-headed geese Anser indicus: connectivity of wintering and breeding grounds across a broad front.  

USGS Publications Warehouse

The connectivity and frequency of exchange between sub-populations of migratory birds is integral to understanding population dynamics over the entire species' range. True geese are highly philopatric and acquire lifetime mates during the winter, suggesting that the number of distinct sub-populations may be related to the number of distinct wintering areas. In the Bar-headed Goose Anser indicus, a species found exclusively in Central Asia, the connectivity between breeding and wintering areas is not well known. Their migration includes crossing a broad front of the Himalaya Cordillera, a significant barrier to migration for most birds. Many Bar-headed Geese fly to breeding areas on the Tibetan-Qinghai Plateau (TQP), the highest plateau in the world. From 2005-2008, 60 Bar-headed Geese were captured and marked with satellite transmitters in Nepal (n = 2), India (n = 6), China (n = 29), and Mongolia (n = 23) to examine their migration and distribution. Distinct differences were observed in their migration corridors and timing of movements, including an apparent leap-frog migration pattern for geese from Mongolia. Measurements of geese from Mongolia were larger than their counterparts from China, providing some evidence of morphological differences. Alteration of habitats in China, including the warming effects of climate change on glaciers increasing runoff to TQP wetlands, may be changing goose migration patterns and timing. With the exception of one individual, all geese from Qinghai Lake, China wintered in the southern TQP near Lhasa, and their increasing numbers in that region may be related to the effects of climate change and agricultural development. Thus, our findings document both morphological and geographical variation in sub-populations of Bar-headed Geese, but their resilience to environmental change may be lost if migratory short-stopping results in larger congregations restricted to a smaller number of wintering areas.

Takekawa, John Y.; Heath, Shane R.; Douglas, David C.; Perry, William M.; Javed, Salim; Newman, Scott H.; Suwal, Rajendra N.; Rahman, Asad R.; Choudhury, Binod C.; Prosser, Diann J.; Yan, Baoping; Hou, Yuansheng; Batbayar, Nyambayar; Natsagdorj, Tseveenmayadag; Bishop, Charles M.; Butler, Patrick J.; Frappell, Peter B.; Milsom, William K.; Scott, Graham R.; Hawkes, Lucy A.; Wikelski, Martin

2009-01-01

58

Cold fronts and multi-temperature structures in the core of Abell 2052  

NASA Astrophysics Data System (ADS)

Context. The physics of the coolest phases in the hot intra-cluster medium (ICM) of clusters of galaxies is yet to be fully unveiled. X-ray cavities blown by the central active galactic nucleus (AGN) contain enough energy to heat the surrounding gas and stop cooling, but locally blobs or filaments of gas appear to be able to cool to low temperatures of 104 K. In X-rays, however, gas with temperatures lower than 0.5 keV is not observed. Aims: We aim to find spatial and multi-temperature structures in the hot gas of the cooling-core cluster Abell 2052 that contain clues on the physics involved in the heating and cooling of the plasma. Methods: 2D maps of the temperature, entropy, and iron abundance are derived from XMM-Newton data of Abell 2052. For the spectral fitting, we use differential emission measure (DEM) models to account for the multi-temperature structure. Results: About 130 kpc South-West of the central galaxy, we discover a discontinuity in the surface brightness of the hot gas which is consistent with a cold front. Interestingly, the iron abundance jumps from ~0.75 to ~0.5 across the front. In a smaller region to the North-West of the central galaxy we find a relatively high contribution of cool 0.5 keV gas, but no X-ray emitting gas is detected below that temperature. However, the region appears to be associated with much cooler H? filaments in the optical waveband. Conclusions: The elliptical shape of the cold front in the SW of the cluster suggests that the front is caused by sloshing of the hot gas in the clusters gravitational potential. This effect is probably an important mechanism to transport metals from the core region to the outer parts of the cluster. The smooth temperature profile across the sharp jump in the metalicity indicates the presence of heat conduction and the lack of mixing across the discontinuity. The cool blob of gas NW of the central galaxy was probably pushed away from the core and squeezed by the adjacent bubble, where it can cool efficiently and relatively undisturbed by the AGN. Shock induced mixing between the two phases may cause the 0.5 keV gas to cool non-radiatively and explain our non-detection of gas below 0.5 keV.

de Plaa, J.; Werner, N.; Simionescu, A.; Kaastra, J. S.; Grange, Y. G.; Vink, J.

2010-11-01

59

Climatic background of cold and wet winter in southern China: part I observational analysis  

NASA Astrophysics Data System (ADS)

This study explores the climate background of anomalous wet and cold winter in southern China, focusing on results in January when most of its disastrous snowstorms and freezing rainfall events were observed. Based on the ERA-40 reanalysis and Climate Research Unit (CRU) observed precipitation and surface temperature monthly data for the period of 1959-2001, the difference between normalised monthly precipitation and temperature is used to define a simple index which reflects the intensity of the wet and cold condition in the region. It offers a good agreement with an index defined by daily weather station data observed in the region. Then, through simple correlation analyses we focus on exploring the dominant physical and dynamical processes leading to such climatic anomalies. While we acknowledge the contribution of the cold/dry air penetrated from the north, the importance of maintaining a warm and moist airflow from the south is highlighted, including an enhanced Middle East Jet Stream (MEJS) and southwesterly flow over Indochina Peninsula and South China Sea region. Strong vertical share of meridional wind, with enhanced northerly flow near the surface and southerly flow in the low to middle troposphere, leads to significant temperature and moisture inversions. These are consistent with results from synoptic analyses of the severe January 2008 event which was not included in the correlation calculations and thus suggest the 2008 event was not an unusual event although it was very intense. In the third part, we use a partial least-square statistical method to uncover dominant SST patterns corresponding to such climatic conditions. By comparing results for the periods of 1949-1978 and 1978-2007, we demonstrate the shift of dominant SST patterns responsible for the wet and cold anomalies. Shifting from "conventional" ENSO SST patterns to ENSO Modoki-like conditions in recent decades partially explains the unstable relationship between ENSO and Asian winter monsoon. Meanwhile, the importance of SST conditions in extra-tropic Pacific and Indian oceans is acknowledged. Finally, we developed a forecasting model which uses SST condition in October to predict the occurrence of the anomalous wet and cold January in the region and reasonable forecasting skill is obtained.

Zhang, Huqiang; Qin, Jun; Li, Yun

2011-12-01

60

The Effects of Cold Acclimation of Winter Wheat Plants on Changes in CO 2 Exchange and Phenolic Compound Formation  

Microsoft Academic Search

We studied CO2 exchange and phenolic compound production in various organs of unhardened and hardened winter wheat (Triticum aestivum L.) plants. The rates of CO2 assimilation at saturating illumination (photosynthesis) and CO2 evolution in darkness (respiration) declined substantially at the autumnal decrease of ambient temperature. However, because of a higher cold resistance of photosynthesis, the ratio of photosynthesis to respiration

N. V. Zagoskina; N. A. Olenichenko; S. V. Klimov; N. V. Astakhova; E. A. Zhivukhina; T. I. Trunova

2005-01-01

61

Research on winter-hardiness: deacclimation resistance, reacclimation ability, photoprotection strategies, and a cold acclimation protocol design  

Technology Transfer Automated Retrieval System (TEKTRAN)

Freezing is a major environmental stress during the annual cycle of temperate zone perennials. Freeze- injury can occur due to mid-winter temperatures that are colder than the tolerance threshold of a tissue / plant or due to untimely freezing temperatures before cold acclimation (development of fre...

62

Winter warming facilitates range expansion: cold tolerance of the butterfly Atalopedes campestris.  

PubMed

Our ability to predict ecological and evolutionary responses to climate change requires an understanding of the mechanistic links between climate and range limits. The warming trend over the past half-century has generated numerous opportunities to develop much-needed case studies of these links. Species that are only limited by climatic factors are likely to shift range quickly during periods of warming. Such species directly impact recipient communities and indicate trends that will become more widespread. Because minimum temperature (T (min)) is rising at twice the rate of maximum temperature, species with this range-limiting factor may be especially responsive to global warming. In this study, I test the hypothesis that rising T (min) has directly affected the range of a skipper butterfly. Atalopedes campestris has moved northward rapidly this century, recently colonizing eastern Washington where January T (min) has risen 3 degrees C in 50 years. The results show that: 1. A. campestris' range lies completely within the -4 degrees C January average minimum isotherm, and that recently colonized areas were below this threshold earlier this century. 2. In acute cold stress experiments, -4 to -7 degrees C proved to be a critical thermal limit: median supercooling point was -6.3 degrees C, and minimum lethal temperature (LT50 with 12-h exposure) was -5.7 degrees C. 3. In chronic cold stress experiments, survivorship declined sharply in diurnally fluctuating thermal regimes typical of the current range edge. High mortality occurred under constant 0 degrees C conditions as well as in fluctuating regimes, implying that thermal insulation from snow would not protect A. campestris. 4. There was no evidence of evolution in cold tolerance at the range margin, despite strong selection. Thus, winter warming was apparently a prerequisite for the range expansion. Characteristics of this species that seem to be associated with its rapid response are that it is an opportunistic species, it is not habitat or dispersal limited, and it is constrained by T (min). PMID:12684862

Crozier, Lisa

2003-04-09

63

Chemical characteristics of PM2.5 and organic aerosol source analysis during cold front episodes in Hong Kong, China  

NASA Astrophysics Data System (ADS)

In this study, we investigate the influence of long-range transport (LRT) episodes brought in by cold front on the concentration levels of PM2.5, major aerosol constituents, organic tracers, and PM2.5 source characteristics in Hong Kong, China. PM2.5 samples were collected during January-March 2004 and January-March 2005 and analyzed for major constituents and organic tracer species. Synoptic weather conditions and characteristics of common air pollutants were used to categorize the sampling days to three groups, i.e., groups mainly affected by local emissions or regional transport (RT) or cold front LRT. Concentrations of PM2.5 mass and its major constituents during cold-front days were lower than those during RT-dominated periods but higher than those during local emissions-dominated periods. Source apportionment using chemical mass balance (CMB) indicates that vehicular exhaust was a significant primary OC source of mainly local emissions, making average contributions of 1.82, 1.50, and 2.39 ?g C m- 3 to OC in the local, LRT, and RT sample groups, respectively. During cold front periods, primary OC concentrations attributable to biomass burning and coal combustion were approximately triple and double, respectively, those during periods dominated by local emissions. Suspended dust, a minor primary OC source (0.24-0.40 ?g C m- 3), also showed increased contribution during cold fronts. The unexplained OC by CMB (i.e., total OC minus apportioned primary OC), an approximate indicator for secondary OC, was a significant fraction of OC (> 48%) and its mass concentration was much higher in the cold front LRT and RT sample groups (6.37 and 9.48 ?g C m- 3) than in the local sample group (3.8 ?g C m- 3). Source analysis as well as tracer concentration variation shows that biomass burning OC and water soluble organic carbon (WSOC) were correlated, suggesting biomass burning as a significant contributor to WSOC.

Li, Yun-Chun; Yu, Jian Zhen; Ho, Steven Sai Hang; Yuan, Zibing; Lau, Alexis K. H.; Huang, Xiao-Feng

2012-11-01

64

Magnetohydrodynamic Simulations of the Formation of Cold Fronts in Clusters of Galaxies: Effects of Anisotropic Viscosity  

NASA Astrophysics Data System (ADS)

We carried out three-dimensional magnetohydrodynamic simulations to study the effects of plasma viscosity on the formation of sharp discontinuities of density and temperature distributions, cold fronts, in clusters of galaxies. By fixing the gravitational potential that confines the cool, dense plasma in a moving subcluster, we simulated its interaction with the hot, lower density plasma around the subcluster. At the initial state, the intracluster medium (ICM) is assumed to be threaded by uniform magnetic fields. The enhancement of plasma viscosity along the direction of magnetic fields is incorporated as anisotropic viscosity depending on the direction of magnetic fields. We found that the Kelvin-Helmholtz instability at the surface of the subcluster grows even in models with anisotropic viscosity, because its effects on the velocity shear across the magnetic field lines are suppressed. We also found that magnetic fields around the interface between the subcluster and ICM are amplified even in the presence of viscosity, while magnetic fields behind the subcluster are amplified up to ?-1 ~ 0.01 in models with viscosity, whereas they are amplified up to ?-1 ~ 0.1 in models without viscosity, where ? is the ratio of gas pressure to magnetic pressure.

Suzuki, Kentaro; Ogawa, Takayuki; Matsumoto, Yosuke; Matsumoto, Ryoji

2013-05-01

65

A coastal front in the Sea of Iyo  

Microsoft Academic Search

In winter a remarkable coastal front is formed off the southeastern coast of the Kunisaki Peninsula in the Sea of Iyo in the western part of the Seto Inland Sea. This coastal front is generated in late November when the density difference between onshore colder water and offshore warmer water vanishes due to the cooling effect of the cold atmosphere.

Tetsuo Yanagi

1980-01-01

66

Calcium Interacts with Antifreeze Proteins and Chitinase from Cold-Acclimated Winter Rye1  

PubMed Central

During cold acclimation, winter rye (Secale cereale) plants accumulate pathogenesis-related proteins that are also antifreeze proteins (AFPs) because they adsorb onto ice and inhibit its growth. Although they promote winter survival in planta, these dual-function AFPs proteins lose activity when stored at subzero temperatures in vitro, so we examined their stability in solutions containing CaCl2, MgCl2, or NaCl. Antifreeze activity was unaffected by salts before freezing, but decreased after freezing and thawing in CaCl2 and was recovered by adding a chelator. Ca2+ enhanced chitinase activity 3- to 5-fold in unfrozen samples, although hydrolytic activity also decreased after freezing and thawing in CaCl2. Native PAGE, circular dichroism, and Trp fluorescence experiments showed that the AFPs partially unfold after freezing and thawing, but they fold more compactly or aggregate in CaCl2. Ruthenium red, which binds to Ca2+-binding sites, readily stained AFPs in the absence of Ca2+, but less stain was visible after freezing and thawing AFPs in CaCl2. We conclude that the structure of AFPs changes during freezing and thawing, creating new Ca2+-binding sites. Once Ca2+ binds to those sites, antifreeze activity, chitinase activity and ruthenium red binding are all inhibited. Because free Ca2+ concentrations are typically low in the apoplast, antifreeze activity is probably stable to freezing and thawing in planta. Ca2+ may regulate chitinase activity if concentrations are increased locally by release from pectin or interaction with Ca2+-binding proteins. Furthermore, antifreeze activity can be easily maintained in vitro by including a chelator during frozen storage.

Stressmann, Maja; Kitao, Satoshi; Griffith, Marilyn; Moresoli, Christine; Bravo, Leon A.; Marangoni, Alejandro G.

2004-01-01

67

Cataloguing Severe Winter Cold Snaps in the Eastern and Midwestern United States for Medium-Range Predictability  

NASA Astrophysics Data System (ADS)

Severe winter weather can be extremely disruptive to daily life and the economy. Accurate forecasts of cold outbreaks are crucial for health and safety, as well as for emergency planning by governments and the transportation and energy sectors. Short-range winter storm warnings have become much more accurate in recent years, however forecasts in the medium-range on the order of two-weeks to a month remain a challenge. To improve probabilistic forecasts, in both accuracy and lead-time, a historical catalog is prepared to describe the evolution of each winter cold outbreak from 1948, including relevant weather-climate connections. A severe cold index (SCI) for the eastern/Midwestern U.S. is constructed for the 1948/49-2008/09 winter periods, where the SCI is a local daily measure of threshold exceedance, taken as the 5th percentile of daily temperatures. The duration and spatial extent of cold spells are also explicitly considered and an “event set” of discrete cold outbreaks is designed based on the historic data. Principal components analysis is applied to surface and atmospheric observations (NCEP Reanalysis and other sources) to identify the predominant weather regimes in each season, and the evolution of these regimes. The SCI is then evaluated to identify consistent precursors. Relationships with relevant climate modes such as ENSO, NAO, PDO, MJO, etc. are used together with the annually-isolated weather regimes to develop statistical models and qualitative rules-of-thumb for use in medium-range to seasonal forecasts. The products are currently designed as a tool for operational meteorologists in forecasting energy demand, but could be functional for other end-users.

Guirguis, K.; Gershunov, A.; Bennett, S.

2009-12-01

68

The relationship of winter season North Atlantic blocking frequencies to extreme cold or dry spells in the ERA-40  

NASA Astrophysics Data System (ADS)

Atmospheric blocking is an important source of low-frequency variability. We apply a blocking detection and tracking method to ERA-40 data for the Atlantic-European region to assess linkages to extreme events, that is, cold and dry spells in the extended winter season (November-April). The method is feature-oriented, identifies 500-hPa geopotential height maxima, and connects them with a next-neighbourhood search in time. The analysis reveals a statistically significant decrease of number of blocking events over the period of ERA-40. Winters with an increased number of blocking events are associated with negative temperature anomalies over Central to Eastern Europe and dryer conditions, whereas Southern Europe experiences warmer and wetter conditions during such episodes. Using extreme value statistics we show evidence that cold spells, and to some extent dry spells, are strongly associated with extremes in blocking frequency. The number of cold spell days increases with the duration of blocking events indicating that cold spells need time to establish during blocking events, thus return periods of cold spells are longer than those for blocking events. This behaviour is not found for the relation of dry spells with blocking events. Still, blocking episodes have a higher occurrence of dry spells than climatology.

Buehler, Tania; Raible, Christoph C.; Stocker, Thomas F.

2010-11-01

69

The relationship of winter season North Atlantic blocking frequencies to extreme cold or dry spells in the ERA-40  

NASA Astrophysics Data System (ADS)

Atmospheric blocking is an important source of low-frequency variability. We apply a blocking detection and tracking method to ERA-40 data for the Atlantic-European region to assess linkages to extreme events, that is, cold and dry spells in the extended winter season (November-April). The method is feature-oriented, identifies 500-hPa geopotential height maxima, and connects them with a next-neighbourhood search in time. The analysis reveals a statistically significant decrease of number of blocking events over the period of ERA-40. Winters with an increased number of blocking events are associated with negative temperature anomalies over Central to Eastern Europe and dryer conditions, whereas Southern Europe experiences warmer and wetter conditions during such episodes. Using extreme value statistics we show evidence that cold spells, and to some extent dry spells, are strongly associated with extremes in blocking frequency. The number of cold spell days increases with the duration of blocking events indicating that cold spells need time to establish during blocking events, thus return periods of cold spells are longer than those for blocking events. This behaviour is not found for the relation of dry spells with blocking events. Still, blocking episodes have a higher occurrence of dry spells than climatology.

Buehler, Tania; Raible, Christoph C.; Stocker, Thomas F.

2011-03-01

70

Cold, Northern Winters: The Importance of Temperature to Overwinter Mortality of Age0 White Crappies  

Microsoft Academic Search

Survival during the first winter of life can influence the recruitment of many fishes. We used field sampling and laboratory experiments to explore the mechanisms underlying first winter growth and survival of white crappie Pomoxis annularis, which exhibits variable recruitment. We sampled age-0 white crappies from four Ohio reservoirs before winter to evaluate whether large individuals had a greater energy

Arthur B. McCollum; David B. Bunnell; Roy A. Stein

2003-01-01

71

The thermal performance of a Roof-Pond integrated to a building for heating during Cold-Winter Desert climate conditions in Saudi Arabia  

Microsoft Academic Search

This study reports an experiment to investigate the feasibility of a passive heating roof-pond system on an existing room in the cold winter conditions of Riyadh, Saudi Arabia. Statistical analyses of data recorded during the winter season of 1996–97, are carried out to evaluate the thermal peformance of the proposed system. Total effective heating and the heating power of the

N. Al-Hemiddi

1999-01-01

72

Creation and tidal advection of a cold salinity front in Storfjorden: 2. Supercooling induced by turbulent mixing of cold water  

NASA Astrophysics Data System (ADS)

Measurements near the edge of fast ice in Freemansundet, Svalbard, reveal mixing processes associated with tidal advection of a sharp front in salinity, including possible supercooling induced by double diffusion in a fully turbulent water column. The front translated back and forth with the semidiurnal tide between an area of mobile (drifting) ice in Storfjorden proper, and the narrow sound covered by fast ice. Water on each side of the front was near its salinity-determined freezing temperature. Instruments deployed about 400 m into the sound from the fast ice edge measured current, temperature, conductivity, and turbulence quantities through several tidal cycles. Turbulence data illustrate that as the steep horizontal salinity (density) gradient advected past the measurement site, vertical shear near the fast-ice base induced marked flood/ebb asymmetry in turbulent mixing. As fresher water entered the sound on the flood phase, inward transport of denser water near the upper boundary was retarded, leading to statically unstable conditions and enhanced turbulence. The opposite occurred during ebb tide, as denser water underran lighter. Transient episodes of supercooling accompanied frontal passage on both flood and ebb phases. The most likely explanation for a zone of supercooled water within the strongly mixed frontal region is that during mixing of fresher, slightly warmer (but still at freezing) water from outside with saltier, colder water in the sound, the former constituent lost heat faster than gaining salt. This interpretation (differing turbulent diffusivities for heat and salt) challenges strict application of Reynolds analogy for highly turbulent shear flow.

McPhee, Miles G.; Skogseth, Ragnheid; Nilsen, Frank; Smedsrud, Lars H.

2013-08-01

73

Thermal sensation and comfort in women exposed repeatedly to whole-body cryotherapy and winter swimming in ice-cold water  

Microsoft Academic Search

Whole-body cryotherapy (WBC; ?110 °C) and winter swimming (WS) in ice-cold water are severe ambient cold exposures, which are voluntarily practiced by humans in minimal clothing. The purpose was to examine thermal sensation and thermal comfort associated with WBC and WS. Twenty women similar in body mass index, age, physical activity, and use of hormonal contraception were pairwise randomized either

Juhani Smolander; Marja Mikkelsson; Juha Oksa; Tarja Westerlund; Juhani Leppäluoto; Pirkko Huttunen

2004-01-01

74

Identification of quantitative trait loci and associated candidate genes for low-temperature tolerance in cold-hardy winter wheat.  

PubMed

Low-temperature (LT) tolerance is an important economic trait in winter wheat (Triticum aestivum L.) that determines the plants' ability to cope with below freezing temperatures. Essential elements of the LT tolerance mechanism are associated with the winter growth habit controlled by the vernalization loci (Vrn-1) on the group 5 chromosomes. To identify genomic regions, which in addition to vrn-1 determine the level of LT tolerance in hexaploid wheat, two doubled haploid (DH) mapping populations were produced using parents with winter growth habit (vrn-A1, vrn-B1, and vrn-D1) but showing different LT tolerance levels. A total of 107 DH lines were analyzed by genetic mapping to produce a consensus map of 2,873 cM. The LT tolerance levels for the Norstar (LT(50)=-20.7 degrees C) x Winter Manitou (LT(50)=-14.3 degrees C) mapping population ranged from -12.0 to -22.0 degrees C. Single marker analysis and interval mapping of phenotyped lines revealed a major quantitative trait locus (QTL) on chromosome 5A and a weaker QTL on chromosome 1D. The 5A QTL located 46 cM proximal to the vrn-A1 locus explained 40% of the LT tolerance variance. Two C-repeat Binding Factor (CBF) genes expressed during cold acclimation in Norstar were located at the peak of the 5A QTL. PMID:16775685

Båga, Monica; Chodaparambil, Sanjay V; Limin, Allen E; Pecar, Marin; Fowler, D Brian; Chibbar, Ravindra N

2006-06-15

75

Creation and tidal advection of a cold salinity front in Storfjorden: 1. Polynya dynamics  

NASA Astrophysics Data System (ADS)

Hydrographical measurements from the Storfjorden polynya document the presence of an abrupt front in near-freezing water dividing saline water recently created by a polynya event, from less saline water originating further south. This event occurred days before the survey with estimated heat flux ˜400 W m-2 over the polynya. Brine-enriched shelf water (BSW) is observed downslope toward deeper parts of Storfjorden, and BSW from earlier polynya events overflows the sill. Current measurements from a nearby sound, Freemansundet, document tidal currents exceeding 80 cm s-1 that displaced the front back and forth beneath the measurement site on fast ice ˜400 m from the polynya edge. Front displacement of ˜12 km is documented and mainly due to the M2 component superimposed on a mean residual current of 0.28 m s-1 into the sound induced by southerly wind during the survey. Complex topography imposes baroclinic tidal currents with strong vertical shear in the fast ice-covered sound, and with significant cross-channel flow. Supercooling events indicated in the hydrographical time series, and likely enhanced frazil ice production, are associated with double-diffusive turbulent mixing when the salinity front passes. In this way, these measurements indicate a novel ice production process along the edge of tidally induced latent heat polynyas where salinity fronts are generated. Turbulence increases (decreases) during flood (ebb) due to the destabilization (stabilization) of the water column when the salinity front passes the measurement site. Double-diffusive turbulent mixing related to tidal advection of salinity front below fast ice is pursued in a companion paper.

Skogseth, Ragnheid; McPhee, Miles G.; Nilsen, Frank; Smedsrud, Lars H.

2013-07-01

76

Extreme temperature contrast of the year 2012 in Greece: An exceptionally cold winter and a record breaking summer  

NASA Astrophysics Data System (ADS)

During the past decade several regions all over Europe have experienced severe heat waves with serious social and environmental impacts. The year of 2003 was characterized by record breaking high temperatures for central Europe, while the year of 2007 was a remarkably warm year of the majority of the Eastern Mediterranean. During this year, three major heat waves were detected in Greece during summer and abnormally high temperatures were also observed through the cold season of 2007. It was found that the winter minimum temperatures were statistically more extreme than the summer maxima. Moreover, exceptionally high maximum and minimum temperatures occurred in November of 2010 affection the entire Greek region while September of the following year was also characterized by large departures of maximum temperatures from the long term mean values and the highest minimum temperature average in comparison to the reference period 1958-2000. The past year (2012) could also be characterized as a year of extremes. This time a temperature contrast was detected in the domain of study with a prolonged cold - season spell during winter and new record - breaking extreme maximum and minimum summer temperatures. More specifically it was found that the summer of 2012 was the warmest one since 1958. The whole season was characterized by long - lasting warm conditions with large departures from the long term (up to 4oC for Tmax) and this warming phenomenon was more intense during July and August. In contrast the winter season (December 2011 - February 2012) was found to be in the ten coldest winters of the last 55 years. The departures from the mean are lower than summer (1oC to 1.5oC negative anomalies) but most of the days were found to have lower Tmax, Tmin and Tmean values than the average daily temperatures of the period 1958-2000. Finally, it is worth mentioning that the year of 2012 was characterized by the highest annual temperature range reaching up to 26oC in several stations. Consequently, these abnormal cold (warm) conditions during the winter (summer) months motivated the present study in order to conduct a statistical analysis of these temperature extremes and their characteristics in addition to an investigation of the synoptic large scale atmospheric conditions which possibly result to this year of contrasts. Acknowledgments: This study has been supported by the Research Committee of the Aristotle University of Thessaloniki.

Tolika, Konstantia; Anagnostopoulou, Christina; Maheras, Panagiotis; Velikou, Kondylia

2013-04-01

77

Cold temperature increases winter fruit removal rate of a bird-dispersed shrub  

Microsoft Academic Search

We tested the hypothesis that winter removal rates of fruits of wax myrtle, Myrica cerifera, are higher in colder winters. Over a 9-year period, we monitored M. cerifera fruit crops in 13 0.1-ha study plots in South Carolina, U.S.A. Peak ripeness occurred in November, whereas peak removal occurred in the coldest months, December and January. Mean time to fruit removal

Charles Kwit; Douglas J. Levey; Cathryn H. Greenberg; Scott F. Pearson; John P. McCarty; Sarah Sargent

2004-01-01

78

The relation of extreme North Atlantic blocking frequencies, cold and dry spells in ERA-40 in winter  

NASA Astrophysics Data System (ADS)

One of the most prominent features of mid-latitude atmospheric variability is blocking. Blocking events are anticyclones with an equivalent barotropic signature and persistent in time. The longer than synoptic day-to-day time scales has led to intrinsic interest during the last decades aiming to expand the predictability beyond classical numerical weather prediction. The study aims to present the extreme behavior of blocking and to investigate relations to other extreme events, like cold and dry spells. To assess the behavior of blocking events we developed a new event-based method. The method identifies 500-hPa geopotential height maxima and tracks these relative maxima with a next-neighborhood search in time. This new method agrees with the reference grid-point based method in the deduced climatological pattern of blocking frequency. Applying the method to ERA-40 data in winter for the Atlantic-European region we found a trend towards a reduction of blocking episodes. The mean surface temperature and precipitation shows a clear response: winters with an increased number of blocking events are associated with negative temperature anomalies over central to eastern Europe and dryer conditions, whereas southern Europe experiences warmer and wetter conditions during such episodes. Using extreme value statistics, we show evidence that cold spells and to some extent dry spells are strongly associated with extremes in blocking frequency over central Europe. We also showed that cold spells need time to establish during blocking events, thus return periods of cold spells are longer than those for blocking events.

Raible, C. C.; Buehler, T.; Stocker, T. F.

2009-04-01

79

Cold core eddies and fronts of the Antarctic Circumpolar Current south of New Zealand from in situ and satellite data  

NASA Astrophysics Data System (ADS)

The meridional heat flux required to balance the heat lost by ocean to atmosphere at high latitudes must be accomplished by some mechanism other than mean advection and the heat flux by eddies crossing the Antarctic Circumpolar Current (ACC) may be a candidate. In this study, the positions of the main ACC fronts are determined based on 23 expendable bathythermographs (XBT) transects collected from 1994 to 2010 and are compared with those detected through satellite altimetry. Then, cold core anomalies in XBT sections are identified and altimetry is used to follow the spatial-temporal evolution of these cold, low sea level anomalies. Mean values of main parameters, such as speed (0.35 km/h), lifetime (79 weeks), and diameter (105 km), are estimated. Moreover, estimations of rotational speed (0.9-76.8 cm/s), ocean surface layer heat content along temperature sections and eddy available heat anomaly (mean value -9.74 × 109 Jm-2) give a wider description of the detected eddies. In our study area, the spawning of eddies is found to occur downstream of the Southeast Indian Ridge and in correspondence of the polar front (PF) with regard to the ACC frontal structure. The contribution of eddies to the global heat budget is not only linked to their ability to cross the ACC fronts but also to the capacity of keeping partially unaltered the properties of water inside them. Analysis of the relation between the translation and rotational speeds shows that a typical eddy may effectively be a significant part (0.8%) of the net meridional heat transport across the PF with a mean heat content/anomaly of -7.65 × 1019 J.

Cotroneo, Yuri; Budillon, Giorgio; Fusco, Giannetta; Spezie, Giancarlo

2013-05-01

80

THE POTENTIAL OF COLD-TOLERANT AVOCADO INTRODUCTIONS IN BREEDING FOR ENHANCED WINTER HARDINESS  

Microsoft Academic Search

Artificial chilling tests reported previously have been continued and indicate that the cold tolerance of a specific avocado seed parent (introduction M-18686) is inherited by an appreciable number of seedlings raised from open pollination. A minority of the second- generation seedlings from this population withstands artificial chilling tests as well as the original introduction, and the cold tolerance of the

R. J. Knight

81

Use of "Cold Spell" indices to quantify excess chronic obstructive pulmonary disease (COPD) morbidity during winter (November to March 2000-2007): case study in Porto.  

PubMed

The aim of this study was to examine the relationship between the occurrence of cold episodes and excess hospital admissions for chronic obstructive pulmonary disease (COPD) in Porto, Portugal, in order to further understand the effects of cold weather on health in milder climates. Excess COPD winter morbidity was calculated from admissions for November to March (2000-2007) in the Greater Porto Metropolitan Area (GPMA). Cold spells were identified using several indices (Díaz, World Meteorological Organization, Cold Spell Duration Index, Australian Index and Ondas' Project Index) for the same period. Excess admissions in the periods before and after the occurrence of cold spells were calculated and related to the cold spells identified. The COPD seasonal variation admission coefficient (CVSA) showed excess winter admissions of 59 %, relative to other months. The effect of cold spell on the aggravation of COPD occurs with a lag of at least 2 weeks and differs according to the index used. This study indicates the important role of the persistence of cold periods of at least 2 weeks duration in the increase in COPD admissions. The persistence of moderate temperatures (Tmin ?5 °C) for a week can be more significant for increasing COPD admissions than very low temperatures (Tmin???1.6 °C) for just a few days. The Ondas projects' index provides the most accurate detection of the negative impacts of cold persistency on health, while the Diaz index is better at evaluating the consequences of short extreme cold events. PMID:23274835

Monteiro, Ana; Carvalho, Vânia; Góis, Joaquim; Sousa, Carlos

2012-12-30

82

Polar Winter: A Biological Model for Impact Events and Related Dark\\/Cold Climatic Changes  

Microsoft Academic Search

Models of the climatic perturbation caused by a large scale extraterrestrial impact predict an injection of dust into the stratosphere. This would cause the onset of environmental conditions whose two principal characteristics are a prolonged period of darkness and reduced global temperatures. Similar scenarios follow large scale volcanic eruptions, wildfires and they are predicted for a nuclear winter following a

Charles S. Cockell; M. Dale Stokes

1999-01-01

83

On the home front: The cold war legacy of the Hanford nuclear site  

SciTech Connect

The Hanford plutonium factory in Washington State is among the oldest and largest relics of the Cold War and is also among the dirtiest. In this book, the author states that the release of radiaoactive and toxic waste without public knowledge poses fundamental questions about American democracy. No conclusive answers to the problems at Hanford are presented, although the important questions are addressed. The reviewer feels the book may be of use as a reference catalog, within its context as a piece essentially concerned with public relations.

Stenehjem Gerber, M.

1992-01-01

84

Proteome Analysis of Cold Response in Spring and Winter Wheat (Triticum aestivum) Crowns Reveals Similarities in Stress Adaptation and Differences in Regulatory Processes between the Growth Habits.  

PubMed

A proteomic response to cold treatment (4 °C) has been studied in crowns of a frost-tolerant winter wheat cultivar Samanta and a frost-sensitive spring wheat cultivar Sandra after short-term (3 days) and long-term (21 days) cold treatments. Densitometric analysis of 2-D differential in gel electrophoresis (2D-DIGE) gels has resulted in the detection of 386 differentially abundant protein spots, which reveal at least a two-fold change between experimental variants. Of these, 58 representative protein spots have been selected for MALDI-TOF/TOF identification, and 36 proteins have been identified. The identified proteins with an increased relative abundance upon cold in both growth habits include proteins involved in carbohydrate catabolism (glycolysis enzymes), redox metabolism (thioredoxin-dependent peroxidase), chaperones, as well as defense-related proteins (protein revealing similarity to thaumatin). Proteins exhibiting a cold-induced increase in the winter cultivar include proteins involved in regulation of stress response and development (germin E, lectin VER2), while proteins showing a cold-induced increase in the spring cultivar include proteins involved in restoration of cell division and plant growth (eIF5A2, glycine-rich RNA-binding protein, adenine phosphoribosyltransferase). These results provide new insights into cold acclimation in spring and winter wheat at the proteome level and enrich our previous work aimed at phytohormone dynamics in the same plant material. PMID:24047233

Kosová, Klára; Vítámvás, Pavel; Planchon, Sébastien; Renaut, Jenny; Vanková, Radomíra; Prášil, Ilja Tom

2013-09-18

85

The response of Carlos Botelho (Lobo, Broa) Reservoir to the passage of cold fronts as reflected by physical, chemical, and biological variables.  

PubMed

This paper describes and discusses the impacts of the passage of cold fronts on the vertical structure of the Carlos Botelho (Lobo-Broa) Reservoir as demonstrated by changes in physical, chemical, and biological variables. The data were obtained with a continuous system measuring 9 variables in vertical profiles in the deepest point of the reservoir (12 m) coupled with climatological information and satellite images, during a 32-day period in July and August, 2003. During periods of incidence of cold fronts the reservoir presented vertical mixing. After the dissipation of the cold fronts a period of stability followed with thermal, chemical, and biological (chlorophyll-a) stratification. Climatological data obtained during the cold front passage showed lower air temperature, higher wind speed and lower solar radiation. The response of this reservoir can exemplify a generalized process in all shallow reservoirs in the Southeast Brazil and could have several implications for management, particularly in relation to the phytoplankton population dynamics and development of cyanobacterial blooms. Using this as a basis, a predictive model will be developed with the aim of advancing management strategies specially for the drinking water reservoirs of the Metropolitan Region of São Paulo. PMID:15195377

Tundisi, J G; Matsumura-Tundisi, T; Arantes Júnior, J D; Tundisi, J E; Manzini, N F; Ducrot, R

2004-08-25

86

Proteins Involved in Distinct Phases of Cold Hardening Process in Frost Resistant Winter Barley (Hordeum vulgare L.) cv Luxor  

PubMed Central

Winter barley is an economically important cereal crop grown in higher latitudes and altitudes where low temperatures represent an important environmental constraint limiting crop productivity. In this study changes in proteome of leaves and crowns in a frost tolerant winter barley cv. Luxor in relation to short and long term periods of cold followed by a brief frost treatment were studied in order to disclose proteins responsible for the cold hardening process in distinct plant tissues. The mentioned changes have been monitored using two dimensional difference gel electrophoresis (2D-DIGE) with subsequent peptide-mapping protein identification. Regarding approximately 600–700 distinct protein spots detected on 2D gels, there has been found at least a two-fold change after exposure to low temperatures in about 10% of proteins in leaves and 13% of proteins in crowns. Protein and nitrogen metabolic processes have been influenced by low temperature to a similar extent in both tissues while catabolism, carbohydrate metabolism and proteins involved in stress response have been more affected in crowns than in leaves. The range of changes in protein abundance was generally higher in leaves and chloroplast proteins were frequently affected which suggests a priority to protect photosynthetic apparatus. Overall, our data proved existence of slightly different response strategies to low temperature stress in crowns and leaves, i.e., tissues with different biological role. Moreover, there have been found several proteins with large increase in accumulation, e.g., 33 kDa oxygen evolving protein of photosystem II in leaves and “enhanced disease susceptibility 1” in crowns; these proteins might have potential to indicate an enhanced level of frost tolerance in barley.

Hlavackova, Iva; Vitamvas, Pavel; Santrucek, Jiri; Kosova, Klara; Zelenkova, Sylva; Prasil, Ilja Tom; Ovesna, Jaroslava; Hynek, Radovan; Kodicek, Milan

2013-01-01

87

Proteins Involved in Distinct Phases of Cold Hardening Process in Frost Resistant Winter Barley (Hordeum vulgare L.) cv Luxor.  

PubMed

Winter barley is an economically important cereal crop grown in higher latitudes and altitudes where low temperatures represent an important environmental constraint limiting crop productivity. In this study changes in proteome of leaves and crowns in a frost tolerant winter barley cv. Luxor in relation to short and long term periods of cold followed by a brief frost treatment were studied in order to disclose proteins responsible for the cold hardening process in distinct plant tissues. The mentioned changes have been monitored using two dimensional difference gel electrophoresis (2D-DIGE) with subsequent peptide-mapping protein identification. Regarding approximately 600-700 distinct protein spots detected on 2D gels, there has been found at least a two-fold change after exposure to low temperatures in about 10% of proteins in leaves and 13% of proteins in crowns. Protein and nitrogen metabolic processes have been influenced by low temperature to a similar extent in both tissues while catabolism, carbohydrate metabolism and proteins involved in stress response have been more affected in crowns than in leaves. The range of changes in protein abundance was generally higher in leaves and chloroplast proteins were frequently affected which suggests a priority to protect photosynthetic apparatus. Overall, our data proved existence of slightly different response strategies to low temperature stress in crowns and leaves, i.e., tissues with different biological role. Moreover, there have been found several proteins with large increase in accumulation, e.g., 33 kDa oxygen evolving protein of photosystem II in leaves and "enhanced disease susceptibility 1" in crowns; these proteins might have potential to indicate an enhanced level of frost tolerance in barley. PMID:23584021

Hlavá?ková, Iva; Vítámvás, Pavel; Santr??ek, Ji?í; Kosová, Klára; Zelenková, Sylva; Prášil, Ilja Tom; Ovesná, Jaroslava; Hynek, Radovan; Kodí?ek, Milan

2013-04-12

88

Viability of the cyanobacterium Planktothrix rubescens in the cold and dark, related to over-winter survival and summer recruitment in Lake Zürich  

Microsoft Academic Search

Over the winter many phytoplankton in deep lakes encounter prolonged periods of dark and cold. Survival times of the planktonic cyanobacterium Planktothrix rubescens were assessed by isolating single filaments of six strains in separate tubes that were stored at 4–5° C in the dark for 2–16 weeks and then incubating them at 20° C in the light. Viable filaments grew

Daryl P. Holland; Anthony E. Walsby

2008-01-01

89

Optimum insulation thickness of residential roof with respect to solar-air degree-hours in hot summer and cold winter zone of china  

Microsoft Academic Search

Thermal protection of building envelope is one of the most effective ways for building energy conservation. In this study, the determination of optimum insulation thickness for residential roof with different surface colors is studied based on life cycle cost analysis and solar-air degree-hours in four typical cities of hot summer and cold winter zone of China. Four insulation materials including

Jinghua Yu; Liwei Tian; Changzhi Yang; Xinhua Xu; Jinbo Wang

2011-01-01

90

European cold winter 2009-2010: How unusual in the instrumental record and how reproducible in the ARPEGE-Climat model?  

NASA Astrophysics Data System (ADS)

Boreal winter 2009-2010 made headlines for cold anomalies in many countries of the northern mid-latitudes. Northern Europe was severely hit by this harsh winter in line with a record persistence of the negative phase of the North Atlantic Oscillation (NAO). In the present study, we first provide a wider perspective on how unusual this winter was by using the recent 20th Century Reanalysis. A weather regime analysis shows that the frequency of the negative NAO was unprecedented since winter 1939-1940, which is then used as a dynamical analog of winter 2009-2010 to demonstrate that the latter might have been much colder without the background global warming observed during the twentieth century. We then use an original nudging technique in ensembles of global atmospheric simulations driven by observed sea surface temperature (SST) and radiative forcings to highlight the relevance of the stratosphere for understanding if not predicting such anomalous winter seasons. Our results demonstrate that an improved representation of the lower stratosphere is necessary to reproduce not only the seasonal mean negative NAO signal, but also its intraseasonal distribution and the corresponding increased probability of cold waves over northern Europe.

Ouzeau, G.; Cattiaux, J.; Douville, H.; Ribes, A.; Saint-Martin, D.

2011-06-01

91

The cold European winter of 2005-2006 assisted the spread and persistence of H5N1 influenza virus in wild birds.  

PubMed

In January 2006, a major cold spell affected Europe, coinciding with an increase of H5N1 influenza virus detected in wild birds, mostly dead mute swans, starting along the River Danube and the Mediterranean coast line. Subsequently H5N1 detections in wild birds were concentrated in central and western parts of Europe, reaching a peak in mid February. We tested the hypothesis that the geographic distribution of these H5N1 infections was modulated by the long-term wintering line, the 0 °C isotherm marking the limit beyond which areas are largely unsuitable for wintering waterfowl. Given the particularly cold 2005-2006 European winter, we also considered the satellite-derived contemporary frost conditions. This brought us to select the long-term maximum rather than the mean January 0 °C isotherm as the best approximation for the 2005-2006 wintering line. Our analysis shows that H5N1 detection sites were closer to the wintering line than would be expected by chance, even when the geographic distribution of water bird wintering sites was accounted for. We argue that partial frost conditions in water bodies are conducive to bird congregation, and this may have enhanced H5N1 transmission and local spread. Because the environmental virus load also would build up in these hot spots, H5N1 virus may have readily persisted during the spring, at least in cooler areas. We conclude that H5N1 introduction, spread, and persistence in Europe may have been enhanced by the cold 2005-2006 winter. PMID:20686815

Ottaviani, Daniela; de la Rocque, S; Khomenko, S; Gilbert, M; Newman, S H; Roche, B; Schwabenbauer, K; Pinto, J; Robinson, T P; Slingenbergh, J

2010-08-05

92

Pretreatment of landfill leachate using deep shaft aeration bioreactor (DSAB) in cold winter season.  

PubMed

A pilot-scale deep shaft aeration bioreactor (DSAB) with 110 m in depth and 0.5m in diameter for the pretreatment of landfill leachate in winter was operated at a daily treatment scale of around 10-20 tons. It was found that the performance of the DSAB mainly depended on the inflow loads and concentrations of pollutants. NH3-N, TN, COD, TOC removals of 66-94%, 41-64%, 67-87%, 55-92% at organic load rate of 1.7-9.4 g CODL(-1)day(-1) and hydraulic retention time of 1-2d were obtained using DSAB, respectively, with the lowest ambient temperature of -3 °C. The effluent COD can be reduced to below 1000 mg/L, an acceptable level for advanced treatment using reverse osmosis system, when the influent COD was below 7000 mg/L at 10t/d. The EEM and GPC analysis implied that the non-biodegradable contaminants such as humic- and fulvic-like DOM dominated in the organic fractions of the effluent, which rendered the biological treatment ineffective. Compared with 20-40% removals obtained using traditional biological processes below 15 °C, DSAB showed a higher treatment efficiency for COD and NH3-N, even though at adverse conditions of poor carbon source, lower C/N ratio and high nitrite concentrations in the leachate of test. PMID:23542320

Niu, Jing; Zhang, Tongju; He, Yijia; Zhou, Haiyan; Zhao, Aihua; Zhao, Youcai

2013-03-06

93

Structure of the Cold Front Observed in SESAME-AVE III and its Comparison with the Hoskins-Bretherton Frontogenesis Model.  

NASA Astrophysics Data System (ADS)

A cold front which passed through the dense network of the SESAME-AVE (Severe Environmental Storms and Mesoscale Experiment-Atmospheric Variability Experiment) on 25-26 April 1979 was investigated. Rawinsonde data collected from 23 special stations and 19 National Weather Service stations at three-hour intervals for a 24-hour period were used along with hourly surface data, radar summary charts and GOES-East satellite images. Severe storms formed along the surface front during this period. The analysis focused on the vertical circulation across the frontal surface at low levels.The major features of the cold frontal system that emerged from an analysis of this unique data set include a familiar direct vertical circulation, with moist warm air ascending just above the surface front. However, the upgliding motion was intercepted by a secondary circulation at middle levels. The analysis result was compared with model predictions of Hoskins and Bretherton (1972) as calculated by Blumen (1980). Several features of the observed front were found to agree qualitatively well with the model prediction. These include: a) Both the horizontal temperature gradient and the vertical component of vorticity have their maxima near the ground surface; b) The horizontal gradient of potential temperature is smaller in the warm air region than in the cold air region; c) The temperature inversion layer representing the frontal surface is located behind and below the axis of the maximum cyclonic relative vorticity. However, the model is found to be less successful in predicting the low-level convergence field; the observed surface convergence and cyclonic vorticity are of the same order of magnitude and concentrated in zones of approximately the same width of 300 km. The observed maximum ascending motion is located at low levels, rather than in middle levels as predicted. The subsidence in the cold air region is also much stronger than the model prediction.

Ogura, Yoshi; Portis, Diane

1982-12-01

94

Enhanced vertical mixing associated with a nocturnal cold front passage and its impact on near-surface temperature and ozone concentration  

NASA Astrophysics Data System (ADS)

A sudden rise in surface temperature is sometimes observed during the nighttime hours with the passage of cold fronts. The physics contributing to such nocturnal warming events and their potential impacts on atmospheric chemistry are not yet fully understood. In this study, a nocturnal warming event associated with a cold front passage in Oklahoma on 3 April 2006 is simulated with the Weather Research and Forecasting model with Chemistry (WRF/Chem). During the prefrontal period under clear-sky and calm conditions, surface radiative cooling resulted in a decoupled shallow surface layer in which air temperature and wind speed decreased quickly and ozone was removed efficiently by chemical reactions. During the passage of the cold front, strong wind shear enhanced turbulent mixing, which weakened the temperature inversion near the surface. Warmer and ozone-richer air from aloft was mixed downward to the surface. Thus, a sudden warming and nocturnal secondary ozone maxima were observed near the surface. Dry deposition of ozone at the surface was also enhanced in this warming event.

Hu, Xiao-Ming; Klein, Petra M.; Xue, Ming; Shapiro, Alan; Nallapareddy, Anita

2013-04-01

95

A Winter Survival Unit.  

ERIC Educational Resources Information Center

|The article is a condensation of materials from the winter survival unit of a Canadian snow ecology course. The unit covers: cold physiology, frostbite, snowblindness, hypothermia, winter campout, and survival strategies. (SB)|

Phillips, Ronald E.

1979-01-01

96

A Winter Survival Unit.  

ERIC Educational Resources Information Center

The article is a condensation of materials from the winter survival unit of a Canadian snow ecology course. The unit covers: cold physiology, frostbite, snowblindness, hypothermia, winter campout, and survival strategies. (SB)

Phillips, Ronald E.

1979-01-01

97

Bio-optical properties and ocean color algorithms for coastal waters influenced by the Mississippi River during a cold front.  

PubMed

During the passage of a cold front in March 2002, bio-optical properties examined in coastal waters impacted by the Mississippi River indicated that westward advective flows and increasing river discharge containing high concentrations of nonalgal particles contributed significantly to surface optical variability. A comparison of seasonal data from three cruises indicated spectral models of absorption and scattering to be generally consistent with other coastal environments, while their parameterization in terms of chlorophyll (Chl) alpha concentration showed seasonal variability. The exponential slope of the colored dissolved organic matter (CDOM) averaged 0.0161+/-0.00054 nm(-1) and nonalgal absorption averaged 0.011 nm(-1) with deviations from general trends observed due to anomalous water properties. Although the phytoplankton specific absorption coefficients varied over a wide range [0.02 to 0.1 m2 (mg Chl)(-1) at 443 nm] being higher in offshore surface waters, values of phytoplankton absorption spectra at the Sea-Viewing Wide Field-of-View Sensor (SeaWiFS) wave bands were highly correlated to modeled values. Particulate scattering characteristics were similar to observations for other coastal waters, while backscattering ratios were on average lower in phytoplankton-dominated surface waters (0.011+/-0.003) and higher in low Chl near-bottom waters (0.0191+/-0.0045). Average percent differences in remote sensing reflectance Rrs derived from modeled and in-water radiometric measurements were highest in the blue wave bands (52%) and at locations with more stratified water columns. SeaWiFS estimates of Chl and CDOM absorption derived using regional empirical algorithms were highly correlated to in situ data. PMID:16983431

D'Sa, Eurico J; Miller, Richard L; Del Castillo, Carlos

2006-10-01

98

A Investigation of Colorado Front Range Winter Storms Using a Nonhydrostatic Mesoscale Numerical Model Designed for Operational Use  

NASA Astrophysics Data System (ADS)

State-of-the-art data sources such as Doppler radar, automated surface observations, wind profiler, digital satellite, and aircraft reports are for the first time providing the capability to generate real-time, operational three-dimensional gridded data sets with sufficient spatial and temporal resolutions to diagnose the structure and evolution of mesoscale systems. A prototype data assimilation system of this type, called the Local Analysis and Prediction System (LAPS), is being developed at the National Oceanic and Atmospheric System's Forecast Systems Laboratory (FSL). The investigation utilizes the three-dimensional LAPS analyses for initialization of the full physics, nonhydrostatic Regional Atmospheric Modeling System (RAMS) model developed at the Colorado State University to create a system capable of generating operational mesoscale predictions. The LAPS/RAMS system structured for operational use can add significant value to existing operational model output and can provide an improved scientific understanding of mesoscale weather events. The results are presented through two case study analyses, the 7 January 1992 Colorado Front Range blizzard and the 8-9 March 1992 eastern Colorado snow storm. Both cases are ideal for this investigation due to the significant mesoscale variation observed in the precipitation and flow structure. The case study results demonstrate the ability to successfully detect and predict mesoscale features using a mesoscale numerical model initialized with high resolution (10 km horizontal grid interval), non-homogeneous data. The strong influence of the Colorado topography on the resultant flow is suggested by the generation of a lee vortex that frequently develops east of the Front Range and south of the Cheyenne Ridge in stable, northwest synoptic flow. The lee vortex exhibits surface flow characteristics that are similar to results from low Froude number flow around an isolated obstacle. A series of numerical experiments using RAMS with idealized topography and horizontally homogeneous initial conditions are presented to investigate typical low Froude number flow characteristics in the vicinity of barriers representative of the Colorado topography. The results are compared to the findings of previous investigations and to the case study observations and numerical predictions.

Snook, John Stover

99

Meteorological influences of eddy-resolving ocean assimilation around the cold tongue to the north of the Japanese islands during winter 2004/2005  

NASA Astrophysics Data System (ADS)

Use of ocean data assimilation in meteorological applications is expected to reveal the influence of cloud-covered oceanic mesoscale processes on wintertime weather and climate in coastal areas. In particular, eddy-resolving Ocean Circulation Model (OCM) data assimilation that reproduces seasonally persistent oceanic mesoscale eddies is useful when simulating coastal precipitation. In the present study, the OCM-assimilation sea surface temperature (SST) is applied to a long-term atmospheric simulation over the Japan/East Sea area in the 2004/2005 winter season (December-February, DJF), to investigate seasonal and daily influences of oceanic mesoscale eddies on precipitation. The simulated winter precipitation is improved by the OCM assimilation via the DJF evaporation around a cold tongue. The strong intrusion of the southeast-directed cold tongue reduces the degree of overestimation by coastal precipitation simulations in December and January. In contrast, the ocean assimilation barely improves the simulation results in February because of weak intrusion of the cold tongue. In December and January, an abruptly large anomaly of northwesterly surface wind (> 1 m s-1) resulting from the OCM assimilation often influences 3-hour precipitation in the downstream area of the cold tongue. In contrast, the slowly-varying anomaly of evaporation does not necessarily lead to daily precipitation anomalies, although the DJF evaporation anomaly is important in the DJF precipitation.

Maeda, Yuko; Yamamoto, Masaru; Hirose, Naoki

2011-08-01

100

Long-Term Growth Under Elevated CO2 Suppresses Biotic Stress Genes in Non-Acclimated, But Not Cold-Acclimated Winter Wheat.  

PubMed

This study compared the photosynthetic performance and the global gene expression of the winter hardy wheat Triticum aestivum cv Norstar grown under non-acclimated (NA) or cold-acclimated (CA) conditions at either ambient CO2 or elevated CO2. CA Norstar maintained comparable light-saturated and CO2-saturated rates of photosynthesis but lower quantum requirements for PSII and non-photochemical quenching relative to NA plants even at elevated CO2. Neither NA nor CA plants were sensitive to feedback inhibition of photosynthesis at elevated CO2. Global gene expression using microarray combined with bioinformatics analysis revealed that genes affected by elevated CO2 were three times higher in NA (1,022 genes) compared with CA (372 genes) Norstar. The most striking effect was the down-regulation of genes involved in the plant defense responses in NA Norstar. In contrast, cold acclimation reversed this down-regulation due to the cold induction of genes involved in plant pathogenesis resistance; and cellular and chloroplast protection. These results suggest that elevated CO2 has less impact on plant performance and productivity in cold-adapted winter hardy plants in the northern climates compared with warmer environments. Selection for cereal cultivars with constitutively higher expression of biotic stress defense genes may be necessary under elevated CO2 during the warm growth period and in warmer climates. PMID:23969557

Kane, Khalil; Dahal, Keshav P; Badawi, Mohamed A; Houde, Mario; Hüner, Norman P A; Sarhan, Fathey

2013-08-21

101

Gelation in protein extracts from cold acclimated and non-acclimated winter rye (Secale cereale L. cv Musketeer).  

PubMed

A protein gel is a three-dimensional network consisting of molecular interactions between biopolymers that entrap a significant volume of a continuous liquid phase (water). Molecular interactions in gels occur at junction zones within and between protein molecules through electrostatic forces, hydrogen bonding, hydrophobic associations (van der Waals attractions) and covalent bonding. Gels have the physicochemical properties of both solids and liquids, and are extremely important in the production and stability of a variety of foods, bioproducts and pharmaceuticals. In this study, gelation was induced in phenol extracted protein fractions from non-acclimated (NA) and cold-acclimated (CA) winter rye (Secale cereale L. cv Musketeer) leaf tissue after repeated freeze-thaw treatments. Gel formation only occurred at high pH (pH 12.0) and a minimum of 3-4 freeze-thaw cycles were required. The gel was thermally stable and only a specific combination of chemical treatments could disrupt the gel network. SDS-PAGE analysis identified ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco) as the major protein component in the gel, although Rubisco itself did not appear to be a factor in gelation. Raman spectroscopy suggested changes in protein secondary structure during freeze-thaw cycles. Overall, the NA and CA gels were similar in composition and structure, with the exception that the CA gel appeared to be amyloidic in nature based on thioflavin T (ThT) fluorescence. Protein gelation, particularly in the apoplast, may confer protection against freeze-induced dehydration and potentially have a commercial application to improve frozen food quality. PMID:23348601

Lim, Ze Long; Low, Nicholas H; Moffatt, Barbara A; Gray, Gordon R

2013-01-21

102

The change of chlorophyll fluorescence parameters in winter barley during recovery after freezing shock and as affected by cold acclimation and irradiance.  

PubMed

The change of chlorophyll fluorescence parameters in froze leaves of 3 leaf-age seedlings were examined using two winter barley cultivars (Chumai 1 and Mo 103) differing in cold tolerance to investigate physiological response to low temperature as affected by cold acclimation (under 3/1 degrees C, day/night for 5 days before freezing treatment) and irradiation size (high irradiance: 380+/-25 micromol m(-2)s(-1) and low irradiance: 60+/-25 micromol m(-2)s(-1)) during recovery. The results showed that non-lethal freezing shock (exposed to -8 degrees C for 18 h) did not obviously affect maximum quantum efficiency in photosystem II (PSII), but dramatically increased non-photochemical quenching and reduced effective quantum yield in PSII. Cold acclimation significantly improved stability of photosynthetic function of leaves after freezing stress through buffering excessive energy and alleviating photoinhibition during recovery, indicating it increased recovery ability of barley plants from freezing injury. High irradiance was quite harmful to the stability of PSII in barley plants during recovery from freezing injury. The electron transport rate of PSII varied with cold-acclimation, irradiance and genotype. Cold acclimation caused significant increase in electron transport rate of PSII for relatively tolerant cultivar Mo 103, but not for relatively sensitive cultivar Chumai 1. It can be concluded that some chlorophyll fluorescence parameters during recovery from freezing shock may be used as the indicators in identification and evaluation of cold tolerance in barley. PMID:17977737

Dai, Fei; Zhou, Meixue; Zhang, Guoping

2007-10-15

103

Cold-front driven storm erosion and overwash in the central part of the Isles Dernieres, a Louisiana barrier-island arc  

USGS Publications Warehouse

Tropical and extratropical storms produce significant erosion on the barrier islands of Louisiana. Over the past 100 years, such storms have produced at least 2 km of northward beach-face retreat and the loss of 63% of the surface area of the Isles Dernieres, a low-lying barrier-island arc along the central Louisiana coast. Elevations on the islands within the arc are typically less than 2 m above mean sea level. The islands typically have a washover-flat topography with occasional, poorly developed, dune-terrace topography consisting of low-lying and broken dunes. The central part of the arc consists of salt-marsh deposits overlain by washover sands along the Gulf of Mexico shoreline. Sand thicknesses range from zero behind the beach, to less than 2 m under the berm crest, and back to zero in the first nearshore trough. The sand veneer is sufficiently thin that storms can strip all the sand from the beach face, exposing the underlying marsh deposits. The geomorphic changes produced by cold fronts, a type of extratropical storm that commonly affect the Isles Dernieres between late fall and early spring are described. Between August 1986 and September 1987, repeated surveys along eleven shore-normal transects that covered 400 m of shoreline revealed the timing and extent of cold-front-produced beach change along a typical section of the central Isles Dernieres. During the study period, the beach face retreated approximately 20 m during the cold-front season but did not rebuild during the subsequent summer. Because the volume of sand deposited on the backshore (5600 m3) was less than the volume of material lost from the beach face (19,200 m3), approximately 13,600 m3 of material disappeared. Assuming that underlying marsh deposits decrease in volume in direct proportion to the amount of beach-face retreat, an estimate of the mud loss during the study period is 14,000 m3. Thus, the decrease in volume along the profiles can be accounted for without removing any sand from the area, suggesting that a major effect of cold fronts is first to strip the sand from the beach face and then to erode the underlying marsh deposits. After being eroded, the mud is lost from the islands because currents transport it away from the islands. ?? 1990.

Dingler, J. R.; Reiss, T. E.

1990-01-01

104

Significant relationships among frost tolerance and net photosynthetic rate, water use efficiency and dehydrin accumulation in cold-treated winter oilseed rapes.  

PubMed

Five winter oilseed rape cultivars (Benefit, Californium, Cortes, Ladoga, Navajo) were subjected to 30 days of cold treatment (4°C) to examine the effect of cold on acquired frost tolerance (FT), dehydrin (DHN) content, and photosynthesis-related parameters. The main aim of this study was to determine whether there are relationships between FT (expressed as LT50 values) and the other parameters measured in the cultivars. While the cultivar Benefit accumulated two types of DHNs (D45 and D35), the other cultivars accumulated three additional DHNs (D97, D47, and D37). The similar-sized DHNs (D45 and D47) were the most abundant; the others exhibited significantly lower accumulations. The highest correlations were detected between LT50 and DHN accumulation (r=-0.815), intrinsic water use efficiency (WUEi; r=-0.643), net photosynthetic rate (r=-0.628), stomatal conductance (r=0.511), and intracellular/intercellular CO2 concentration (r=0.505). Those cultivars that exhibited higher Pn rate in cold (and further a significant increase in WUEi) had higher levels of DHNs and also higher FT. No significant correlation was observed between LT50 and E, PRI, or NDVI. Overall, we have shown the selected physiological parameters to be able to distinguish different FT cultivars of winter oilseed rape. PMID:24054752

Urban, Milan Old?ich; Klíma, Miroslav; Vítámvás, Pavel; Vašek, Jakub; Hilgert-Delgado, Alois Albert; Ku?era, Vratislav

2013-09-18

105

Cold season CH4 and CO2 emission from boreal peat bogs (West Siberia): Winter fluxes and thaw activation dynamics  

NASA Astrophysics Data System (ADS)

The conventional chamber technique was used to measure CH4 and CO2emission to the atmosphere from snow-covered ombrotrophic bogs (57°N, 82°E, Plotnikovo, West Siberia). The average ± standard deviation values for CH4 and CO2fluxes in mid-February were found to be equal mg m-2 d-15.0 ± 3.7 and 69±52, respectively. The contribution of cold season to annual methane fluxes varied from 3.5 to 11% depending on the calculation method and was similar to that found in Alaska and northern Minnesota. The vertical profiles of gases in snow were linear implying the applicability of the simple diffusion equation under steady state conditions. The diffusion reduction factor due to porous resistance and tortuousity of snowpack was 0.18 and 0.29 for methane and carbon dioxide, respectively. Thus snow forms only a passive cap which controls the gas concentration at the snow-soil interface, while gas flux into the atmosphere is controlled by gas production in the soil. The fresh samples of frozen peat soil incubated under laboratory conditions at constant temperature -16°C displayed very slow, but steady respiration varied from 0.05 to 0.2 mg CO2-C d-1 dm-3depending on peat sampling depth. Although this activity was 200-300 times lower than soil respiration in summertime, it was enough to support the observed in situ winter CO2 emission. The thaw and subsequent peat incubation at 15°C accelerated gas formation up to 2-5 mg CO2-C and 1.2 mg CH4-C h-1 dm-3of peat after 3-4 days of incubation followed by a decline by 1 order of magnitude and approaching a new steady state level. Although the mechanism of freeze-thaw activation needs further clarification, it was nevertheless possible to simulate the observed activation dynamics by a mathematical model which accounts for the burst of microbial growth on nutrients released into soil from frost-damaged cells.

Panikov, N. S.; Dedysh, S. N.

2000-12-01

106

Tongue-shaped frontal structure and warm water intrusion in the southern Yellow Sea in winter  

Microsoft Academic Search

In winter, a thermohaline front forms at the Yellow Sea (YS) entrance where the warm and saline Cheju Warm Current (CWC) water meets cold coastal water. The frontal structure, as well as the northwestward intrusion of the warm water, was investigated by analyzing conductivity-temperature-depth (CTD) data, tracks of drifting floats, moored current data, and satellite images. The CWC water advances

Heung-Jae Lie; Cheol-Ho Cho; Seok Lee

2009-01-01

107

On the effects of vertical air velocity on winter precipitation types  

Microsoft Academic Search

The various precipitation types formed within winter storms (such as snow, wet snow and freezing rain) of- ten lead to very hazardous weather conditions. These types of precipitation often occur during the passage of a warm front as a warm air mass ascends over a cold air mass. To address this issue further, we used a one-dimensional kine- matic cloud

J. M. Thériault; R. E. Stewart

2007-01-01

108

On the effects of vertical air velocity on winter precipitation types  

Microsoft Academic Search

The various precipitation types formed within winter storms (such as snow, wet snow and freezing rain) often lead to very hazardous weather conditions. These types of precipitation often occur during the passage of a warm front as a warm air mass ascends over a cold air mass. To address this issue further, we used a one-dimensional kinematic cloud model to

J. M. Thériault; R. E. Stewart

2007-01-01

109

Nutrition for winter sports  

Microsoft Academic Search

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

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

2011-01-01

110

Winter variation in physiological status of cold stored and freshly lifted semi-evergreen Quercus nigra seedlings  

Microsoft Academic Search

Water oak (Quercus nigra L.) is a tardily deciduous species commonly planted in afforestation projects in the Lower Mississippi River Alluvial Valley, USA. Field performance is often marked by low survival rates and top dieback, which may be associated with poor physiological quality of planting stock. • We investigated physiological status of cold stored (2-4 ?C; CS) and freshly lifted

Rosa C. Goodman; Douglass F. Jacobs; Kent G. Apostol; Barrett C. Wilson; Emile S. Gardiner

2009-01-01

111

Synergism of riverine and winter storm-related sediment transport processes in Louisiana's coastal wetlands  

SciTech Connect

The roles of various mechanisms that supply sediments from major sources, including rivers and the nearshore shelf, to coastal Louisiana are not well understood or quantified, temporally or spatially. Recent studies reveal that an important association between riverine sediment input and the cyclic passage of winter storms results in a periodic supply of suspended sediments to coastal marshlands. The fact that these two mechanisms coincide maximizes the availability of particulate matter for counteracting coastal land loss. Overbank sedimentation is one mechanism that supplies sediment from rivers to coastal wetlands. It occurs when stages exceed bankfull, most commonly in winter and spring. The timing of riverine sedimentation events is also related to suspended sediment concentrations and loads, which are also consistently greater during the winter and early spring months. During high discharge years, more sediment is available in winter than in other seasons, because at such times the sediment concentration and load maxima generally precede discharge maxima by several months. This period of maximum suspended sediment availability is coincident with the most severe winter storm activity, which elevates water levels near the coast and enhances suspended sediment transport to wetlands. Cold fronts also serve as a mechanism for suspended sediment transport, and qualitative observations suggest that during a typical cold-front passage onshore transport of suspended sediments is more likely. Prefrontal stages of winter cold-front passages along the Louisiana coast are characterized by prolonged periods of high wave action from the southerly quadrants, water level setup along the coast, and strong alongshore as well as onshore transport. At these times, suspended sediments from riverine input and the nearshore shelf are mobilized by the combination of riverine and cold front-related processes.

Mossa, J. (Geological Survey, Baton Rouge, LA (USA)); Roberts, H.H. (Louisiana State Univ., Baton Rouge (USA))

1990-09-01

112

Plasma membrane lipid alterations associated with cold acclimation of winter rye seedlings (Secale cereale L. cv Puma)  

SciTech Connect

Highly enriched plasma membrane fractions were isolated from leaves of nonacclimated (NA) and acclimated (ACC) rye (Secale cereale L. cv Puma) seedlings. Collectively, free sterols, steryl glucosides, and acylated steryl glucosides constituted > 50 mole % of the total lipid in both NA and ACC plasma membrane fractions. Glucocerebrosides containing hydroxy fatty acids constituted the major glycolipid class of the plasma membrane, accounting for 16 mole % of the total lipid. Phospholipids, primarily phosphatidylcholine and phosphatidylethanolamine with lesser amounts of phosphatidylglycerol, phosphatidic acid, phosphatidylserine, and phosphatidylinositol, comprised only 32 mole% of the total lipid in NA samples. Following cold acclimation, free sterols increased from 33 to 44 mole %, while steryl glucosides and acylated steryl glucosides decreased from 15 to 6 mole % and 4 to 1 mole %, respectively. Sterol analyses of these lipid classes demonstrated that free {beta}-sitosterol increased from 21 to 32 mole % (accounting for the increase in free sterols as a class) at the expense of sterol derivatives containing {beta}-sitosterol. Glucocerebrosides decreased from 16 to 7 mole % of the total lipid following cold acclimation. In addition, the relative proportions of associated hydroxy fatty acids, including 22:0 (h), 24:0 (h), 22:1 (h), and 24:1 (h) were altered. The phospholipid content of the plasma membrane fraction increased to 42 mole % of the total lipid following cold acclimation. Although the relative proportions of the individual phospholipids did not change appreciably after cold acclimation, there were substantial differences in the molecular species. Di-unsaturated molecular species of phosphatidylcholine and phosphatidylethanolamine increased following acclimation. These results demonstrate that cold acclimation results in substantial changes in the lipid composition of the plasma membrane.

Lynch, D.V.; Steponkus, P.L. (Cornell Univ., Ithaca, NY (USA))

1987-01-01

113

Winter World Explorations  

NSDL National Science Digital Library

Cold winter weather can cause us to retreat into our indoor shells biding our time until the warmer days return. However, there is much to explore outside during the wintertime and the following sites share some important reasons and cautionary tips for Winter World Explorations. The first website, Princeton University's Outdoor Action Guide to Winter Camping by Rick Curtis, provides a thorough overview of Winter Camping including sections on Winter Travel, Snowshoeing Basics, Winter Water, and more. This site also provides links to OA Guides for Winter Shelters, and Hypothermia and Cold Injuries (1). The second site, from the Search and Rescue Society of British Columbia deals specifically with Hypothermia including useful information on Physiology, Signs, Symptoms, and Treatment Considerations (2). The third website, SnowSchool, is an innovative educational field program designed for 4th and 5th graders where "kids venture out into America's winter wildlands to discover all the living creatures under the snow." SnowSchool is a program of Winter Wildlands Alliance and "the nation's largest on-snow winter ecology education program" with 27 sites across the United States (3). The fourth website from the Minnesota DNR is a feature on Winter Bird Feeding which includes specific information about Winter Foods, Seeds and Mixes, Suet, Feeders, and Winter Feeder Layout (4). The fifth website, The Native Conifers of North America, is an excellent and very comprehensive online introduction and field guide to conifer species native to North America. The site includes A Key to the Genera and Species, sections on Selected Conifers from Different Parts of North America, and many beautiful photographs and line drawings (5). The sixth website (6) hosts an article on Winter Nutrition: Tips for people who exercise in the cold by nutrition counselor Nancy Clark, MS, RD. In her article, Ms. Clark answers common winter exercise questions like Why do I shiver when I get cold?, and Why do I feel hungrier in the winter than in the summer? Speaking of being hungrier in the winter, the final two websites offer recipes for winter stews and soups, a perfect way to end a day of winter exploring. One website offers a Hearty Winter Stew recipe from the University of Michigan Health System-Nutrition Services (7}. The other website, from The Ohio State University Extension -- Family Nutrition Program Newsletter tells us that January is National Soup Month, and offers recipes for stews, soups, and even instructions for bread soup bowls (8).

114

A comparison of the immunochemical affinity of cytoplasmic, mitochondrial and nuclear proteins of winter rye ( Secale cereale L.) to a 310 kD stress protein in control plants and during exposure to cold stress  

Microsoft Academic Search

An investigation of immunochemical affinity to stress protein CSP 310 proteins among the native cytoplasmic, mitochondrial and nuclear proteins of winter rye (Secale cereale L.) was carried out by PAGE-electrophoresis in control plants and in plants during exposure to cold stress. Western blotting showed that among the native proteins of all cellular fractions of control plants investigated there was immunochemical

A. V Kolesnichenko; V. V Zykova; V. K Voinikov

2000-01-01

115

Winter variation in physiological status of cold stored and freshly lifted semi-evergreen Quercus nigra seedlings  

Microsoft Academic Search

– \\u000a \\u000a • Water oak (Quercus nigra L.) is a tardily deciduous species commonly planted in afforestation projects in the Lower Mississippi River Alluvial Valley,\\u000a USA. Field performance is often marked by low survival rates and top dieback, which may be associated with poor physiological\\u000a quality of planting stock.\\u000a \\u000a \\u000a \\u000a \\u000a – \\u000a \\u000a • We investigated physiological status of cold stored (2–4 °C; CS)

Rosa C. Goodman; Douglass F. Jacobs; Kent G. Apostol; Barrett C. Wilson; Emile S. Gardiner

2009-01-01

116

Ultrastructural Changes during Swelling and Contraction of Mitochondria from Cold-hardened and Non-hardened Winter Wheat.  

PubMed

Mitochondria isolated from both 2 and 24 C grown winter wheat (Triticum aestivum L.) undergo spontaneous swelling in isomolar KCI solutions, but only 24 C mitochondria exhibit a substrate-induced contraction response. Electron microscopic examination revealed that 24 C mitochondria have more clearly defined cristae, less matrix material, and are generally more electron-dense than 2 C mitochondria. During swelling, the matrix material of both 2 and 24 C mitochondria expands and the mitochondria become less electron-dense. After partial swelling, 24 C mitochondria contract upon addition of succinate, and regain structural characteristics similar to those of untreated mitochondria. In contrast, mitochondria from 2 C seedlings continue to swell after addition of substrate, and many of the mitochondria become irregular in shape and lose much of their matrix material. A comparison of results obtained from absorbancy measurements, electron microscopy, and a Coulter Counter indicate that swelling and contraction involve changes both in over-all volume, and internal structural characteristics of mitochondria from 2 and 24 C grown seedlings. Electron microscopic examination of shoot cells showed that mitochondria in 24 C grown seedlings possessed more recognizable cristae and greater internal organization than mitochondria in 2 C seedlings. PMID:16659827

Pomeroy, M K

1977-02-01

117

The effects of day and night temperatures during early growth of winter oilseed rape ( Brassica napus L. var. oleifera cv. Górcza?ski) seedlings on their morphology and cold acclimation responses  

Microsoft Academic Search

Studies on the effects of temperature during the early stage of growth on frost resistance of winter rape seedlings under\\u000a controlled conditions were performed. It was found that cold acclimation responses of plants were affected to a great extent\\u000a by the conditions of the seedlings early growth. During this period, when the day temperatures were reduced to the range from

Marcin Rapacz

1998-01-01

118

A study on a snowband associated with a coastal front and cold-air damming event of 3-4 February 1998 along the eastern coast of the Korean Peninsula  

NASA Astrophysics Data System (ADS)

A 24-h simulation with the Advanced Regional Prediction System (ARPS) nonhydrostatic model is performed for the heavy snowfall event of 3-4 February 1998 along the eastern coast of Korean Peninsula; the results are used to understand the snowfall process, including why the precipitation maxima formed along the Yeongdong coastal region rather than over the mountain slope and ridge top during. The numerical simulation with a 4-km horizontal grid spacing and 43 levels reproduces very well the narrow snowband located off the eastern Korean coast, away from, instead of over, the Yeongdong coastal mountain range. The general evolution of the snowband agrees quite well with radar observations, while the water-equivalent precipitation amount agrees reasonably well with radar precipitation estimate. The simulation results clearly show that the snow band developed due to the lifting by a coastal front that developed because of the damming of cold air against the eastern slope of the coastal mountain range. The damming was enhanced by the advection of cold air by a low-level mountain-parallel jet from the north, formed due to geostrophic adjustment as the on-shore upslope air was decelerated by the mountain blocking. As the onshore flow weakened later due to synoptic-scale flow pattern change, the cold front propagated off shore and the precipitation dissipated.

Lee, Jae-Gyoo; Xue, Ming

2013-03-01

119

Winter storms over Canada  

Microsoft Academic Search

Various type of winter storms occur over Canada and produce major impacts on society. Canada is subjected to extra?tropical cyclones with all their embedded structures, as well as blizzards, mountain?induced storms, lake effect storms and polar lows. Many of these storms are accompanied by heavy precipitation in the form of snow or freezing precipitation, bitterly cold conditions, strong winds, and

R. E. Stewart; D. Bachand; R. R. Dunkley; A. C. Giles; B. Lawson; L. Legal; S. T. Miller; B. P. Murphy; M. N. Parker; B. J. Paruk; M. K. Yau

1995-01-01

120

Climatology of winter transition days for the contiguous USA, 1951-2007  

NASA Astrophysics Data System (ADS)

In middle and high latitudes, climate change could impact the frequency and characteristics of frontal passages. Although transitions between air masses are significant features of the general circulation that influence human activities and other surface processes, they are much more difficult to objectively identify than single variables like temperature or even extreme events like fires, droughts, and floods. The recently developed Spatial Synoptic Classification (SSC) provides a fairly objective means of identifying frontal passages. In this research, we determine the specific meteorological patterns represented by the SSC's Transition category, a "catch-all" group that attempts to identify those days that cannot be characterized as a single, homogeneous air mass type. The result is a detailed transition climatology for the continental USA. We identify four subtypes of the Transition category based on intra-day sea level pressure change and dew point temperature change. Across the contiguous USA, most transition days are identified as cold fronts and warm fronts during the winter season. Among the two less common subtypes, transition days in which the dew point temperature and pressure both rise are more frequently observed across the western states, and days in which both variables fall are more frequently observed in coastal regions. The relative frequencies of wintertime warm and cold fronts have changed over the period 1951-2007. Relative cold front frequency has significantly increased in the Northeast and Midwest regions, and warm front frequencies have declined in the Midwest, Rocky Mountain, and Pacific Northwest regions. The overall shift toward cold fronts and away from warm fronts across the northern USA arises from a combination of an enhanced ridge over western North America and a northward shift of storm tracks throughout the mid-latitudes. These results are consistent with projections of climate change associated with elevated greenhouse gas concentrations.

Hondula, David M.; Davis, Robert E.

2011-01-01

121

Cold Weather and Cardiovascular Disease  

MedlinePLUS

Cold Weather and Cardiovascular Disease Updated:Dec 11,2012 The fall and winter seasons will bring cooler temperatures, and ... and snow. It’s important to know how cold weather can affect your heart, especially if you have ...

122

Fluctuations of the thermal fronts off northeastern Taiwan  

NASA Astrophysics Data System (ADS)

A high-resolution sea surface temperature (SST) data derived from several satellites is used to investigate the variability of the thermal front off northeastern Taiwan. Hidden by a dominant annual cycle, the SST data cannot reveal the thermal front fluctuation in the form of Hovmöller diagram. An innovative methodology has been applied to the SST satellite imagery to derive the SST Standardized Index (SSTSI), capable of revealing the frontal variability with multiple time scales. Principal component analysis shows that the SSTSI variation consists mainly of two modes. Mode 1 represents a strong annual cycle related to the seasonal reversal of the monsoonal winds. The temperature gradient is enhanced in winter and a cold dome is observed off northern Taiwan in summer. Mode 2 is highly correlated with the upstream Kuroshio variability. The shoreward (seaward) migration of the thermal front takes place when the Kuroshio transport weakens (strengthens). The results are consistent with transports estimated by tidal gauge measurements, satellite altimeter-based sea level anomaly, and surface flow patterns derived from high-frequency radars. Mode 2 is coherent with the Kuroshio transport through the East Taiwan Channel at periods of 120 and 45 d with a time lag of 40 and 11 d, respectively. This 120 d fluctuation is due to the interaction between westward-propagating eddies and the Kuroshio east of Taiwan, while the 45 d signal arises from the Kuroshio's self-instability. The interannual variations of the SST pattern in winter and summer are also discussed.

Hsin, Yi-Chia; Chiang, Tzu-Ling; Wu, Chau-Ron

2011-10-01

123

Stationary fronts prolong bad weather  

NSDL National Science Digital Library

These simple animated GIF's are activated with cursor rollover and picture the standoff when neither the warm front nor the cold front is advancing. On a weather map the stationary front is marked by alternating triangles and half circles with the triangles pointing toward the warm air and the circles pointing toward the cooler air. The overriding of warm air on the cooler air can bring several days of cloudy, inclement weather. While the front appears to touch the ground the actual boundary between air masses can be thousands of feet aloft and hundreds of miles away.

Herne, John; Today, Usa

124

Objective fronts  

NASA Astrophysics Data System (ADS)

This paper addresses the long-standing problem of plotting atmospheric fronts objectively. A thermodynamic definition of a front is proposed. Time-independent diagnostic quantities are then devised according to this definition. These can be computed from any gridded dataset. Fronts are then plotted, without human intervention, by utilising standard graphics package facilities, such as contouring, to represent the diagnostics. The methodology includes applying threshold criteria to erase automatically fronts which are thermally weak. By tuning these criteria a good match with subjective fronts is obtained. In addition, the objective surface fronts very often coincide with troughs in surface pressure, implying that a thermodynamic definition is sufficient. The objective front-plotting is further developed to recognise split fronts, and ana- and kata-front characteristics. Many examples are presented; these illustrate how objective fronts are potentially a very powerful tool for both forecasting and research. At the Joint Centre for Mesoscale Meteorology plots and animations showing objective fronts have been produced on a daily basis for many months now.

Hewson, T. D.

1998-03-01

125

Cold injuries.  

PubMed

There are two categories of cold injury. The first is hypothermia, which is a systemic injury to cold, and the second is frostbite, which is a local injury. Throughout history, entire armies, from George Washington to the Germans on the Russian Front in World War II, have fallen prey to prolonged cold exposure. Cold injury is common and can occur in all seasons if ambient temperature is lower than the core body temperature. In the 1985 Boston Marathon, even though it was 76 degrees and sunny, there were 75 runners treated for hypothermia. In general, humans adapt poorly to cold exposure. Children are at particular risk because of their relatively greater surface area/body mass ratio, causing them to cool even more rapidly than adults. Because of this, the human's best defense against cold injury is to limit his/her exposure to cold and to dress appropriately. If cold injury has occurred and is mild, often simple passive rewarming such as dry blankets and a warm room are sufficient treatment. PMID:17630517

Kruse, R J

1995-01-01

126

Livable Winter Cities--Leisure Attitudes and Activities.  

ERIC Educational Resources Information Center

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

Neal, Larry; Coles, Roger, Ed.

1989-01-01

127

Warm winter spells in the Swiss Alps: Strong heat waves in a cold season? A study focusing on climate observations at the Saentis high mountain site  

Microsoft Academic Search

Investigations conducted for several Swiss mountain climatological sites, and in particular the Saentis high mountain site at 2,500 m above sea level, show that positive temperature anomalies during the winter season currently exceed those of all other seasons. These ``heat waves'' exhibit daily maximum temperature anomalies sometimes in excess of 16°C, and are observed to have increased substantially since the

Martin Beniston

2005-01-01

128

PM10 modeling of Beijing in the winter  

NASA Astrophysics Data System (ADS)

The megacity of Beijing, China, has had an air pollution problem since the 1990s. The concentrations of particulate matter with an aerodynamic diameter less than 10 ?m (PM10) in Beijing in the winter of 2000 were high; the average value of 188 ?g m -3 was nearly four times the first grade national standard of 50 ?g m -3. The CALPUFF modeling system was used to simulate PM10 dispersion from 1 January 2000 to 29 February 2000. We used near real-time landcover data from the moderate resolution imaging spectroradiometer (MODIS). Statistical evaluation indicated that the model agreed well with the observations. The fluctuations of 24-h PM10 concentrations followed the winter synoptic winds. Cold air from the northwest or north intruded over Beijing for average periods of 4 days in winter, accompanied by high wind speeds. PM10 was swept out of Beijing after the cold fronts and accumulated again once the winds stopped, until the next cold air intrusion. Capital Steel Corporation Limited contributed 46% of the PM10 mass concentrations observed in the Shijingshan industrial area, and had little effect on the eastern part or the center of Beijing. The other industrial regions distributed in southeastern Beijing accounted for an average of 18% of the PM10 in Beijing. Boilers associated with coal consumption mostly for winter heating contributed 31%. Motor vehicles and road dust contributed 5% and 13%, respectively. The total of residential heating in old houses and restaurants contributed approximately 7%. The primary PM10 emissions from electrical generating units were relatively low. Some suggestions are proposed for reducing PM10 pollution in Beijing.

Song, Yu; Zhang, Minsi; Cai, Xuhui

129

Weather fronts and acute myocardial infarction  

NASA Astrophysics Data System (ADS)

Some methodological aspects are discussed of the investigation of acute infarct myocarditis (AIM) in relation to weather fronts. Results of a new method of analysis are given. Data were analysed from about the hour of the onset of symptoms, and led to the diagnosis of AIM either immediately or within a few hours or days (3019 cases observed over 4.5 years during 1982 1986 in Plzen, Czechoslovakia). Weather classification was based on three factors (the type of the foregoing front, the type of the subsequent front, the time section of the time interval demarcated by the passage of the surfaces of the fronts). AIM occurrence increased in particular types of weather fronts: (i) by 30% during 7 12 h after a warm front, if the time span between fronts exceeded 24 h; (ii) by 10% in time at least 36 h distant from the foregoing cold or occlusion front and from the succeeding warm or occlusion front; (iii) by 20% during 0 2 h before the passage of the front, provided the foregoing front was not warm and the interval between fronts exceeded 5 h. AIM occurrence decreased by 15% 20% for time span between fronts > 24 h at times 6 11, 6 23 and 6 35 h before a coming warm or occlusion front (for interfrontal intervals 25 48, 49 72 and possibly > 72 h), and also at 12 23 and possibly 12 35 h before a cold front (for intervals 49 72 and possibly > 72 h), if the foregoing front was cold or an occlusion front.

Kveton, Vit

1991-03-01

130

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

1996-01-01

131

Wintertime sea surface temperature fronts in the Taiwan Strait  

NASA Astrophysics Data System (ADS)

We present wintertime variations and distributions of sea surface temperature (SST) fronts in the Taiwan Strait by applying an entropy-based edge detection method to 10-year (1996-2005) satellite SST images with grid size of 0.01°. From climatological monthly mean maps of SST gradient magnitude in winter, we identify four significant SST fronts in the Taiwan Strait. The Mainland China Coastal Front is a long frontal band along the 50-m isobath near the Chinese coast. The sharp Peng-Chang Front appears along the Peng-Hu Channel and extends northward around the Chang-Yuen Ridge. The Taiwan Bank Front evolves in early winter. As the winter progresses, the front becomes broad and moves toward the Chinese coast, connecting to the Mainland China Coastal Front. The Kuroshio Front extends northeastward from the northeastern tip of Taiwan with a semicircle-shape curving along the 100-m isobath.

Chang, Yi; Shimada, Teruhisa; Lee, Ming-An; Lu, Hsueh-Jung; Sakaida, Futoki; Kawamura, Hiroshi

2006-12-01

132

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

133

Plant performance in a warmer world: general responses of plants from cold, northern biomes and the importance of winter and spring events  

Microsoft Academic Search

During the past three decades the Earth has warmed with a rate unprecedented during the past 1000 years. There is already\\u000a ample evidence that this fast climate warming has affected a broad range of organisms, including plants. Plants from high-latitude\\u000a and high-altitude sites (‘cold biomes’) are especially sensitive to climate warming. In this paper we (1) review the response\\u000a in

R. Aerts; J. H. C. Cornelissen; E. Dorrepaal

134

Plant Performance in a Warmer World: General Responses of Plants from Cold, Northern Biomes and the Importance of Winter and Spring Events  

Microsoft Academic Search

During the past three decades the Earth has warmed with a rate unprecedented during the past 1000 years. There is already\\u000a ample evidence that this fast climate warming has affected a broad range of organisms, including plants. Plants from high-latitude\\u000a and high-altitude sites (‘cold biomes’) are especially sensitive to climate warming. In this paper we (1) review the response\\u000a in

R. Aerts; J. H. C. Cornelissen; E. Dorrepaal

2006-01-01

135

Cold-air cyclogenesis along the Gulf-Stream front: investigation of diabatic impacts on cyclone development, frontal structure, and track  

NASA Astrophysics Data System (ADS)

On 24 25 February 1989 a storm brought high winds and moderate to heavy snow to the U.S. East Coast. The storm is noteworthy for its rapid mesoscale development within a polar air mass at relatively low latitudes and for the difficulty experienced by operational NWP models and forecasters in predicting the storm’s impact. This paper investigates the mesoscale structure and evolution of the cold-air cyclone through analysis of enhanced data sets collected during the \\underlineExperiment on \\underlineRapidly \\underlineIntensifying \\underlineCyclones over the \\underlineAtlantic (ERICA). Results are presented from numerical sensitivity studies of the impact of diabatic heating on storm structure and track using the Mesoscale Atmospheric Simulation System (MASS) model.

Businger, S.; Graziano, T. M.; Kaplan, M. L.; Rozumalski, R. A.

2005-03-01

136

Air Masses and Fronts - Fronts and the Surface Weather Map.  

National Technical Information Service (NTIS)

Explains the use of surface weather maps and shows how fronts form from warm and cold air. Shows how weather patterns appear on the map and discusses general wind directions, wind shifts, low pressure trough, frontal surfaces, and temperature changes. Als...

1994-01-01

137

Winter Festival.  

ERIC Educational Resources Information Center

This is one of a series of elementary readers written in Cantonese and English and designed to familiarize children with the traditional major Chinese festivals celebrated by the Chinese in America. This booklet describes the occasion for the Winter Festival (the beginning of winter) and follows a Chinese-American family in its preparation for and…

Lew, Gordon

138

Winter Festival.  

ERIC Educational Resources Information Center

|This is one of a series of elementary readers written in Cantonese and English and designed to familiarize children with the traditional major Chinese festivals celebrated by the Chinese in America. This booklet describes the occasion for the Winter Festival (the beginning of winter) and follows a Chinese-American family in its preparation for…

Lew, Gordon

139

Winter mortality and its causes.  

PubMed

In the 1970s scientific research focussed for the first time on dramatic rises in mortality every winter, and on smaller rises in unusually hot weather. Following the recent decline in influenza epidemics, approximately half of excess winter deaths are due to coronary thrombosis. These peak about two days after the peak of a cold spell. Approximately half the remaining winter deaths are caused by respiratory disease, and these peak about 12 days after peak cold. The rapid coronary deaths are due mainly to haemoconcentration resulting from fluid shifts during cold exposure; some later coronary deaths are secondary to respiratory disease. Heat related deaths often result from haemoconcentration resulting from loss of salt and water in sweat. With the possible exception of some tropical countries, global warming can be expected to reduce cold related deaths more than it increases the rarer heat related deaths, but statistics on populations in different climates suggest that, given time, people will adjust to global warming with little change in either mortality. Some measures may be needed to control insect borne diseases during global warming, but current indications are that cold will remain the main environmental cause of illness and death. Air pollution in cities may also still be causing some deaths, but these are hard to differentiate from the more numerous deaths due to associated cold weather, and clear identification of pollution deaths may need more extensive data than is currently available. PMID:12546188

Keatinge, W R

2002-11-01

140

Evolution of a Cold Front Encountering Steep Quasi-2D Terrain: Coordinated Aircraft Observations on 8 9 December 2001 during IMPROVE-2.  

NASA Astrophysics Data System (ADS)

Research aircraft observations from the 8 9 December 2001 case of the second phase of the Improvement of Microphysical Parameterization through Operational Verification Experiment (IMPROVE-2) describe the evolution of a wide cold-frontal rainband (WCFR) during its eastward advance from the Pacific coastline to a point 200 km inland over the Cascade Mountains of Oregon. This analysis has two objectives: first, to illustrate the rapid weakening of the circulation associated with a landfalling WCFR and the relationship of these changes to terrain-induced airflow modifications, and second, to quantify the degree to which this weakening impacted cloud microphysical properties such as liquid water content, ice particle concentrations, and precipitation rate. The kinematic structure of the WCFR is detailed using Doppler radar observations from a NOAA P-3 aircraft, while some concomitant cloud microphysical properties are documented using flight-level measurements from the University of Washington Convair-580 aircraft. An accompanying the fifth-generation Pennsylvania State University National Center for Atmospheric Research (PSU NCAR) Mesoscale Model (MM5) control simulation (nested to a horizontal resolution of 4 km over the IMPROVE-2 domain) provides a mesosynoptic context and thermodynamic information to complement the aircraft observations. To the authors’ knowledge, this case study represents the most complete documentation obtained to date of the rapid modifications that may occur when a frontal rainband progresses from coastal waters into a region of prominent terrain.

Bond, N. A.; Smull, B. F.; Stoelinga, M. T.; Woods, C. P.; Haase, A.

2005-10-01

141

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.

Foundation, Wgbh E.

2010-12-13

142

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

143

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. 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. ...

Brieanne

2011-02-14

144

Production and Depletion of Supercooled Liquid Water in a Colorado Winter Storm.  

NASA Astrophysics Data System (ADS)

During the 1990 Winter Icing and Storms Project (WISP), a shallow cold front passed through northeastern Colorado, followed by a secondary cold front. A broad high pressure area behind the initial front set up a Denver cyclone circulation within a well-mixed boundary layer, which was capped by a stable, nearly saturated layer of air left in place by the initial cold front. As the secondary cold front passed through the WISP domain, these layers of air were lifted. The lifted boundary layer formed only broken cloud, but the lifted moist layer formed a stratiform cloud that contained high liquid water contents. Cloud characteristics were measured in situ with a research aircraft, and remotely by ground-based radars, microwave radiometers, and a lidar ceilometer. Moderate to severe icing conditions were reported by aircraft flying in the area during the event and also affected the flight of the research aircraft through an increase in drag on the airframe. Liquid water was depleted in portions of the lower stratiform cloud as ice crystals, produced in midlevel clouds embedded in westerly flow, fell into the lower cloud, and quickly rimed to form showers of graupel at the ground. After these midlevel clouds passed over the area, liquid production resumed. Supercooled liquid cloud persisted for 36 h as cloud formed within the surface cold air mass behind the secondary cold front as it entered the Denver area and was lifted over the local terrain.The evolution of weather events is discussed using a variety of datasets, including radar, surface mesonet, balloon-borne soundings, research aircraft, satellite imagery, microwave radiometers, and standard National Weather Service observations. By combining information from these varied sources, processes governing the production and depletion of supercooled liquid from the synoptic to the microscale are examined. The storm is also discussed in terms of its potential for causing moderate to severe aircraft icing. The effect of accreted ice on the research aircraft is described, as are implications of the meteorology for detection and forecasting inflight icing.

Politovich, Marcia K.; Bernstein, Ben C.

1995-12-01

145

The January 2009 anomalous precipitation associated with the “Tail-end of the Cold Front” weather system in Northern and Eastern Mindanao (Philippines): Natural hazards, impacts and risk reductions  

NASA Astrophysics Data System (ADS)

In the first half of January 2009, the southern Philippine island of Mindanao was overwhelmed by numerous natural disasters caused by the passage of the tail-end of the cold front. This otherwise ordinary weather condition was accompanied by unusually heavy precipitation sustained over a period of several days. This triggered numerous landslides and caused many drainage systems to swell, flooding huge tracts of low lying areas that have not experienced similar events in the recent past. Many communities were caught unprepared for the calamity. The amount and extent of damage reflect both the magnitude of the natural disaster itself and the community's nominal level of disaster-preparedness. In view of the increasing atmospheric moisture levels and the likelihood that global warming will affect the weather patterns, there is a possibility that similar weather disturbances can become more frequent. Therefore, there is an urgent need for disaster risk management programs to be developed or enhanced at the local community level especially in areas most vulnerable to weather-related natural hazards, in light of changing global climatic patterns.

Faustino-Eslava, Decibel V.; Yumul, Graciano P., Jr.; Servando, Nathaniel T.; Dimalanta, Carla B.

2011-03-01

146

Ponds Freeze in Winter -- Why Doesn't the Ocean?  

NSDL National Science Digital Library

In this activity, learners explore how salt water freezes in comparison to fresh water. Use this experiment to consider how pond animals survive cold winters in comparison to animals that live in the ocean. This resource includes information about freezing points as well as examples of how different animals respond to the winter cold.

Aquarium, New E.

2011-01-01

147

Vertical Structure of Local Fronts Observed in Kanto, Japan  

Microsoft Academic Search

This paper focuses on two cases of a local front that formed ahead of a synoptic cold front under a southwesterly inflow in the Kanto region. Vertical sounding data provided by an observation network of the Tsukuba Area Precipitation Studies (TAPS) enabled a detailed investigation of the mesoscale structure in the vicinity of the local front from its formation through

Naoko SEINO; Hiroshi YOSHIKADO; Fumiaki KOBAYASHI; Junji SATO

2003-01-01

148

Chemical depletion of Arctic ozone in winter 1999\\/2000  

Microsoft Academic Search

During Arctic winters with a cold, stable stratospheric circulation, reactions on the surface of polar stratospheric clouds (PSCs) lead to elevated abundances of chlorine monoxide (ClO) that, in the presence of sunlight, destroy ozone. Here we show that PSCs were more widespread during the 1999\\/2000 Arctic winter than for any other Arctic winter in the past two decades. We have

M. Rex; R. J. Salawitch; N. R. P. Harris; P. von der Gathen; G. O. Braathen; A. Schulz; H. Deckelmann; M. Chipperfield; B.-M. Sinnhuber; E. Reimer; R. Alfier; R. Bevilacqua; K. Hoppel; M. Fromm; J. Lumpe; H. Küllmann; A. Kleinböhl; H. Bremer; M. von König; K. Künzi; D. Toohey; H. Vömel; E. Richard; K. Aikin; H. Jost; J. B. Greenblatt; M. Loewenstein; J. R. Podolske; C. R. Webster; G. J. Flesch; D. C. Scott; R. L. Herman; J. W. Elkins; E. A. Ray; F. L. Moore; D. F. Hurst; P. Romashkin; G. C. Toon; B. Sen; J. J. Margitan; P. Wennberg; R. Neuber; M. Allart; B. R. Bojkov; H. Claude; J. Davies; W. Davies; H. De Backer; H. Dier; V. Dorokhov; H. Fast; Y. Kondo; E. Kyrö; Z. Litynska; I. S. Mikkelsen; M. J. Molyneux; E. Moran; T. Nagai; H. Nakane; C. Parrondo; F. Ravegnani; P. Skrivankova; P. Viatte; V. Yushkov

2002-01-01

149

Nuclear winter  

Microsoft Academic Search

The 13 speakers at the October 1983 Conference on the World After Nuclear War each contributed specialized knowledge to the climatic and biological effects of nuclear war. The author highlights the findings of the TTAPS (named for its authors) study and confirmation by Soviet scientists on the nuclear winter. Atmospheric consequences would come from debris blocking sunlight and creating conditions

Ehrlich

1984-01-01

150

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.

151

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…

Coy, Mary

2011-01-01

152

Winter's Tale  

NSDL National Science Digital Library

This resource explores winter weather and frozen precipitation. Precipitation (in the form of snow, sleet and freezing rain) is explained, as are a variety of cloud types and generation, the nature and generation of the jet stream, and the aesthetic wonders of frozen water. A bibliography is also provided.

153

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.

154

Phospholipase A2 activity during cold acclimation of wheat  

Technology Transfer Automated Retrieval System (TEKTRAN)

Phospholipase A2 (EC 3.1.1.4; PLA2) activity in wheat (Triticum aestivum L.) crown tissue from plants undergoing cold acclimation and/or chilling stress was investigated in a moderately cold tolerant winter wheat, a spring wheat, and a poorly cold tolerant winter wheat. Activity levels were inv...

155

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

156

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 ...

Sappa, Mr.

2010-05-26

157

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? ...

Smith, Miss

2010-09-27

158

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 ...

Liz, Miss

2010-05-26

159

`Thermohaline front' off the east coast of India and its generating mechanism  

NASA Astrophysics Data System (ADS)

Physical oceanography measurements reveal a strong salinity (0.18 psu km-1) and temperature (0.07 °C km-1) front off the east coast of India in December 1997. T-S diagrams suggest lateral mixing between the fresh water at the coast and the ambient warmer, saltier water. This front seems to be the result of southward advection of fresh and cool water, formed in the northern Bay of Bengal during the monsoon, by the East Indian Coastal Current, as suggested by the large-scale salinity structure in the SODA re-analysis and the anti-cyclonic gyre in the northwestern Bay of Bengal during winter. The data further reveals an offshore front in January, which appears to be the result of a meso-scale re-circulation around an eddy, bringing cold and freshwater from the northern Bay of Bengal further away from the shore. Our cruise data hence illustrates that very strong salinity fronts can appear in the Bay of Bengal after the monsoon, as a result of intense coastal circulation and stirring by eddies.

Hareesh Kumar, Panangattu Viswanathan; Mathew, Basil; Ramesh Kumar, Madathiparambil Ranganatha; Raghunadha Rao, Akula; Jagadeesh, Puvvala Surya Venkata; Radhakrishnan, Kalarickal Gopalan; Shyni, Thiyyadi Nandakumar

2013-09-01

160

How Cold Is Cold?  

NSDL National Science Digital Library

Heat and cold are often difficult concepts for children to understand. First, our everyday sloppy language gives them a predisposition to such common misconceptions as cold being a substance that moves from place to place. Our colloquial language often re

Konicek-Moran, Richard

2008-04-01

161

Medicines In My Home: Know Your Medicines for Colds, Fever ...  

Center for Drug Evaluation (CDER)

Text Version... Pain Winter is here and its a season filled with holidays, snow, school vacation (yippee!)… and winter cold and flu season. ... More results from www.fda.gov/downloads/drugs/resourcesforyou

162

Some characteristics of the surface boundary layer of a strong cold air process over southern China  

NASA Astrophysics Data System (ADS)

In southern China, cold air is a common weather process during the winter season; it can cause strong wind, sharp temperature decreases, and even the snow or freezing rain events. However, the features of the atmospheric boundary layer during cold air passage are not clearly understood due to the lack of comprehensive observation data, especially regarding turbulence. In this study, four-layer gradient meteorological observation data and one-layer, 10-Hz ultrasonic anemometer-thermometer monitoring data from the northern side of Poyang Lake were employed to study the main features of the surface boundary layer during a strong cold-air passage over southern China. The results show that, with the passage of a cold air front, the wind speed exhibits low-frequency variations and that the wind systematically descends. During the strong wind period, the wind speed increases with height in the surface layer. Regular gust packets are superimposed on the basic strong wind flow. Before the passage of cold air, the wind gusts exhibit a coherent structure. The wind and turbulent momentum fluxes are small, although the gusty wind momentum flux is slightly larger than the turbulent momentum flux. However, during the invasion of cold air, both the gusty wind and turbulent momentum fluxes increase rapidly with wind speed, and the turbulent momentum flux is larger than the gusty wind momentum flux during the strong wind period. After the cold air invasion, this structure almost disappears.

Liu, Ximing; Cheng, Xueling; Wu, Qiong; Fu, Minning; Zeng, Qingcun

2013-01-01

163

Cold waves in Serbia  

NASA Astrophysics Data System (ADS)

Climate extreme indices allow the assessment of changes in extreme climate events. The cold Spell Duration Indice (CSDI), from which the duration and severity of the cold waves are estimated, was applied to the seasonal series of the daily minimum temperatures at 15 meteorological stations in Serbia during the period 1949 to 2012. An analysis of the daily minimum temperatures during the winter season revealed that the longest (up to 20-22 days) and most severe cold waves were recorded in 1954, 1956, 1963 and 1983. In the transient seasons, the cooling episodes were observed in 1983 and 1988 (autumn season) and in 1987 (spring season) followed with a great reduction in duration and severity of cold waves. During the summer season, only in 1962, the longest (from 6 to 8 days) and most intense cold wave was registered almost over the whole territory of Serbia.

Unkasevic, Miroslava; Tosic, Ivana

2013-04-01

164

Spatiotemporal variability of thermal front features in the Baltic Sea 2010-2011  

NASA Astrophysics Data System (ADS)

Regions of the formation of the thermal front in the Baltic Sea (a direct manifestation of the lacustrine thermal bar), and its specific features, were analyzed on the basis of subsurface temperature and salinity. Data were obtained from 25 horizontal tows along sections in the southern and central parts of the Baltic Sea during spring 2010 and autumn/winter 2010/2011. The width of the front was approximately 5-30 km, and the front lifetime was 1.5 months. Horizontal temperature ranged from 0.7 to 2.5°C; thus, the temperature gradient was one- to twofold larger than the long-term monthly mean equivalent. Analysis of hourly temperature and salinity data from the Arkona basin and at the Darss Sill, obtained at 2 m depth, indicated that the surface temperature increased during the transition through temperatures of maximum density at a rate of approximately 0.01-0.02°C/h between 3-5 days; which is 1.4- to 5-fold higher than values before and after this period. The thermal front simultaneously propagated along the main sea axis (due to the significant salinity and buoyancy flux variations from south to north), and from the shallow parts towards the deep parts of the Baltic Sea. Therefore, the horizontal advection of the cold/warm waters clearly contributes to the speed increase of the thermal front at the end of the respective season. The speed of the thermal front propagation from south to north was approximately 28 km/day at the end of the spring period of 2010 (based on field data). This was considerably higher in comparison with the typical values of the lacustrine thermal bar speeds; however, it accords with estimates for a basin with depth/salinity horizontal variation.

Demchenko, N. Yu.; Chubarenko, I. P.

2012-11-01

165

Ocean circulation and fronts as related to ice melt-back in the Chukchi Sea  

Microsoft Academic Search

In summer at the edge of the retreating ice pack in the Chukchi Sea, a sharp temperature and salinity front is formed as the result of ice melt by warm surface water from the south. Beneath this front another front is present, formed from the juxtaposition of the resident winter bottom water under the ice and a water transitional between

Robert G. Paquette; Robert H. Bourke

1981-01-01

166

Leap Day 2012 Severe Storm Front  

NASA Video Gallery

This movie was created using GOES-13 visible and infrared satellite imagery from Feb. 28 at 1245 UTC (7:45 a.m. EST) through March 1, and shows the progression of the cold front and associated low pressure area moving over the central U.S. that triggered at least 20 tornadoes and severe weather on February 29, 2012.

Karl Hille

2012-03-01

167

Equatorial Front Between Peru and Galapagos.  

National Technical Information Service (NTIS)

The equatorial front, lying between Peru and the Galapagos, is a narrow, shallow feature separating the cold, salty waters of the Peru Current from the warmer and fresher tropical waters farther north. As one passes southward into the Peru Current, the tr...

W. S. Wooster

1969-01-01

168

Where Does Bluetongue Virus Sleep in the Winter?  

Microsoft Academic Search

Bluetongue recently spread to northern Europe for the first time. Outbreaks in temperate regions are often interrupted by cold weather, but may reappear months later. Where, then, might bluetongue virus sleep in the winter?

Anthony Wilson; Karin Darpel; Philip Scott Mellor

2008-01-01

169

FRIGIDA-related genes are required for the winter-annual habit in Arabidopsis  

Microsoft Academic Search

In temperate climates, the prolonged cold temperature of winter serves as a seasonal landmark for winter-annual and biennial plants. In these plants, flowering is blocked before winter. In Arabidopsis thaliana, natural variation in the FRIGIDA (FRI) gene is a major determinate of the rapid-cycling vs. winter-annual flowering habits. In winter-annual accessions of Arabidopsis, FRI activity blocks flowering through the up-regulation

Scott D. Michaels; Isabel C. Bezerra; Richard M. Amasino

2004-01-01

170

Discovering the Azores front/current system with SeaWiFS imagery  

NASA Astrophysics Data System (ADS)

Ocean Colour (OC) sensors have been primarily used in biological studies. More recently, OC information has been attracting the attention of oceanographers, as a potential method for revealing physical structures in the ocean. In this study, OC data obtained from SeaWiFS imagery is used, for the first time, to detect the weak Azores Current (AzC) and the associated Azores Front (AzF). Previous studies show that the frontal interface is well seen on SST imagery only during the cold season, while it is disguised during the warm season through the formation of a strong seasonal thermocline. With SeaWiFS imagery, the frontal interface is well identified around 34° N as an asymmetric zonally stretched band of higher near-surface chlorophyll a (CHL a) values north of the AzF, accompanied by a sharp decrease to the south. Quasi-stationary meanders, previously derived from SST fields for the same region, are also well observed in OC imagery. Monthly-averaged Chl a along a meridional cross-section shows that, from spring to autumn, the front is clearly visible. In winter, differences across the front are less pronounced, and the front is more easily identified on SST fields. OC gradients weaken to the east, corresponding to the general weakening of the AzC. In situ CTD data reveal a sharp and meandering thermohaline and dissolved oxygen front ocated at 33-34.5° N and 31° W. This study suggests that OC imagery, combined with other sensors, provide an important tool to investigate ocean dynamic variability, by helping to detect frontal zones with great precision.

Martins, Ana M.; Bashmachnikov, Igor L.; Lafon, Virginie M.; Mendonca, Ana H.; Jose, Felix; Figueiredo, Miguel P.; Macedo, Luis M.

2004-11-01

171

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

Microsoft Academic Search

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

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

172

The mesoscale structure of fronts within extratropical cyclones over the ocean  

Microsoft Academic Search

Analyses of the finescale structure of a cold and warm front within oceanic extratropical cyclones are presented. The primary data platforms used in this study were airborne Doppler radars. The oceanic cold front was characterized by precipitation core and gap regions. The precipitation cores appear to form as a result of the combined effects of horizontal shearing instability and the

Brian Lance Bosart

2000-01-01

173

Common Cold  

MedlinePLUS

... nose, coughing - everyone knows the symptoms of the common cold. It is probably the most common illness. In ... avoid colds. There is no cure for the common cold. For relief, try Getting plenty of rest Drinking ...

174

Antifreeze Protein Produced Endogenously in Winter Rye Leaves 1  

PubMed Central

After cold acclimation, winter rye (Secale cereale L.) is able to withstand the formation of extracellular ice at freezing temperatures. We now show, for the first time, that cold-acclimated winter rye plants contain endogenously produced antifreeze protein. The protein was extracted from the apoplast of winter rye leaves, where ice forms during freezing. After partial purification, the protein was identified as antifreeze protein because it modified the normal growth pattern of ice crystals and depressed the freezing temperature of water noncolligatively. Images Figure 1 Figure 3 Figure 4

Griffith, Marilyn; Ala, Paul; Yang, Daniel S. C.; Hon, Wai-Ching; Moffatt, Barbara A.

1992-01-01

175

Winter Weather at Valley Forge 1777-1778: A Lesson in Climatic Reconstruction.  

ERIC Educational Resources Information Center

Notes that the story of George Washington's encampment at Valley Forge is seldom told without reference to the bitter cold winter Washington and his troops endured. Shows how to use historical reports of weather information to allow students to judge for themselves whether the winter at Valley Forge then was harsher than winters in the same area…

Ansley, Mary Jane; Pritchard, Sandra F.

1987-01-01

176

On Future European Cold Spells  

NASA Astrophysics Data System (ADS)

Many studies exist that show that in a warming future climate, European winter cold spells will become less frequent, less intense, and less persistent. Indeed, many metrics like, the annual number of frost days, the number of ice days, and winter heating degree days (known from the energy sector) do show significant negative trends. Yet the anomalous circulations that lead to the cold spells appear not to show such strong negative trends. With advection being the most important source for temperature variability at mid-latitudes, and especially for Western Europe, this brings forward the idea that the non-uniform pattern of global warming itself, and the modification of the mean (westerly) circulation must be the key-factors to explain the changes in cold-spell statistics. These two factors mainly affect the mean and variance of the winter probability density function. It is shown that many of the future changes in cold-spell statistics are indeed readily explained by taking into account only changes of the (increased) mean and (reduced) variance of the daily winter temperature probability density function.

de Vries, H.; Haarsma, R. J.; Hazeleger, W.

2012-04-01

177

Science of Winter  

NSDL National Science Digital Library

Science of Winter is a collection of activities, lessons, interactives, images, or other content illustrating or demonstrating scientific aspects of winter weather, conditions, processes, or phenomena, appropriate for middle school, informal education, and general audiences.

2009-07-30

178

Winter tornadoes in Ireland: The case of the Athlone tornado of 12 January 2004  

NASA Astrophysics Data System (ADS)

Records to date show that the maximum frequency of tornadoes in Ireland is during the summer months of July and August. However, significant tornadoes have also occurred during the winter months. This study identifies the main characteristics of such events in Ireland and examines one particular case that occurred on 12th January 2004 in the town of Athlone, County Westmeath. It occurred at approximately 2000 UTC, during the hours of darkness. This, together with the severe weather that occurred at the same time, minimised the eyewitness evidence. But site investigations established a recognisable, narrow damage track approximately 4.15 km long and local witness evidence suggests it lasted between 15 and 20 min. The synoptic environment for this event consisted of a cold front that was crossing Ireland from the west. This was in close proximity to a strong jet streak at 300 hPa and an upper level trough with an intense cold pool of air. Overall there was very modest instability. However, both horizontal and vertical wind shear was very marked, at middle levels and, in particular, low levels up to 800 hPa. This appears to have played the major role in the development of a favourable environment for the tornado. Mesoscale detail from radar images suggests that the tornado occurred in a storm cell behind the cold front along a surface boundary between the rear outflow from a storm cell ahead of it and surface winds from the SSW. It is also suggested that low level wind speed shear may have produced a downburst into the flank of the Athlone storm cell and created a bow echo of particularly small space time dimensions, a mere 11 km long lasting for up to 30 min. The tornado occurred in the northern ‘bookend’ portion of the bow echo. If so, this is the first record of a bow echo tornado for Ireland.

Tyrrell, John

2007-02-01

179

WINTER COVER CROPS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Winter cover crops (WCC) are important universal tools that can be used to conserve environmental sustainability. In general, the term 'winter cover crop' is used to describe a cover crop grown to protect the soil during the winter fallow period. A cover crop can be used even during summer, especial...

180

Stationary superfluid turbulent fronts  

NASA Astrophysics Data System (ADS)

Stationary fronts of superfluid turbulence have been produced in small nonuniform channels. The front occurs at that position in the channel where the local velocity reaches the critical value. Converging and diverging flows in a channel of circular cross section and diverging flow in a channel of rectangular cross section have been studied. The front in the diverging circular channel is anomalous, becoming unstable at a position near the middle of the channel.

Tough, J. T.; Kafkalidis, J. F.; Klinich, G.; Murphy, P. J.; Castiglione, J.

1994-02-01

181

Front Matter: Volume 8821  

NASA Astrophysics Data System (ADS)

This PDF file contains the front matter associated with SPIE Proceedings Volume 8821, including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.

Plesniak, Adam P.

2013-09-01

182

Front Matter: Volume 8823  

NASA Astrophysics Data System (ADS)

This PDF file contains the front matter associated with SPIE Proceedings Volume 8823, including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.

Eldada, Louay A.; Heben, Michael J.

2013-09-01

183

Front Matter: Volume 8914  

NASA Astrophysics Data System (ADS)

This PDF file contains the front matter associated with SPIE Proceedings Volume 8914 including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.

SPIE, Proceedings of

2013-08-01

184

Front Matter: Volume 8912  

NASA Astrophysics Data System (ADS)

This PDF file contains the front matter associated with SPIE Proceedings Volume 8912 including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.

SPIE, Proceedings of

2013-08-01

185

Front Matter: Volume 8825  

NASA Astrophysics Data System (ADS)

This PDF file contains the front matter associated with SPIE Proceedings Volume 8825, including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.

Dhere, Neelkanth G.; Wohlgemuth, John H.; Lynn, Kevin W.

2013-09-01

186

Front Matter: Volume 8826  

NASA Astrophysics Data System (ADS)

This PDF file contains the front matter associated with SPIE Proceedings Volume 8826, including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.

Reutzel, Edward W.

2013-09-01

187

Front Matter: Volume 8905  

NASA Astrophysics Data System (ADS)

This PDF file contains the front matter associated with SPIE Proceedings Volume 8905 including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.

Amzajerdian, Farzin; Aksnes, Astrid; Chen, Weibiao; Gao, Chunqing; Zheng, Yongchao; Wang, Cheng

2013-09-01

188

Front Matter: Volume 8827  

NASA Astrophysics Data System (ADS)

This PDF file contains the front matter associated with SPIE Proceedings Volume 8827, including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.

Eich, Manfred; Nunzi, Jean-Michel; Jakubiak, Rachel

2013-09-01

189

Front Matter: Volume 8904  

NASA Astrophysics Data System (ADS)

This PDF file contains the front matter associated with SPIE Proceedings Volume 8904, including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.

Tünnermann, Andreas; Liu, Zejin; Wang, Pu; Tang, Chun

2013-09-01

190

Front Matter: Volume 8824  

NASA Astrophysics Data System (ADS)

This PDF file contains the front matter associated with SPIE Proceedings Volume 8824, including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.

Sulima, Oleg V.; Conibeer, Gavin

2013-09-01

191

Front Matter: Volume 6986  

NASA Astrophysics Data System (ADS)

This PDF file contains the front matter associated with SPIE Proceedings Volume 6986, including the Title Page, Copyright information, Table of Contents, Introduction, and the Conference Committee listing.

SPIE, Proceedings of

2008-05-01

192

Front Matter: Volume 8454  

NASA Astrophysics Data System (ADS)

This PDF file contains the front matter associated with SPIE Proceedings Volume 8454, including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.

SPIE, Proceedings of

2012-05-01

193

Interannual Variation of Cold Frontal Activity in Spring in Mongolia  

Microsoft Academic Search

In Mongolia and northern China, most of the dust storms in spring occur in association with a passage of cold front formed at the leading edge of cold air outbreak. In this study, we propose an index to evaluate a cold frontal activity by identifying \\

Masamitsu HAYASAKI; Seiji SUGATA; H. L. TANAKA

2006-01-01

194

The after-effects of temperature and irradiance during early growth of winter oilseed rape ( Brassica napus L. var. oleifera, cv. Górcza?ski) seedlings on the progress of their cold acclimation  

Microsoft Academic Search

Experiments performed under controlled conditions showed that level of PPFD (photosynthetic photon flux density) during early\\u000a seedlings growth (preceding cold acclimation at +2 °C) was not the key factor for the development of frost resistance. It\\u000a did not modify the beneficial effects of prehardening (Rapacz 1997, in this issue) at moderately low (+12 °C) day temperature.\\u000a \\u000a Now I have shown

Marcin Rapacz

1998-01-01

195

Common Cold  

NSDL National Science Digital Library

This Web site provides comprehensive information, selected by medical doctors, about the common cold. The goal is to provide a framework for critical thinking which will allow informed decisions about medical care for the common cold. The section entitled Understanding Colds gives a detailed overview of how the cold virus invades the human body and how cold symptoms are caused. Information about preventing colds, and some of the complications that can occur are also included. The Special Features section includes one of the most interesting parts of the site -- Myths of the Common Cold. This site should be interesting to almost anyone, but perhaps more so for those of us who have recently had a cold.

2007-12-12

196

Common cold  

MedlinePLUS

... C for preventing and treating the common cold. Cochrane Database of Systematic Reviews 2007, Issue 3. Art. ... M, Das RR. Zinc for the common cold. Cochrane Database of Systematic Reviews 2011, Issue 2. Art. ...

197

The isotopic composition of precipitation from a winter storm - a case study with the limited-area model COSMOiso  

NASA Astrophysics Data System (ADS)

Stable water isotopes are valuable tracers of the atmospheric water cycle, and potentially provide useful information also on weather-related processes. In order to further explore this potential, the water isotopes H218O and HDO are incorporated into the limited-area model COSMO. In a first case study, the new COSMOiso model is used for simulating a winter storm event in January 1986 over the eastern United States associated with intense frontal precipitation. The modelled isotope ratios in precipitation and water vapour are compared to spatially distributed ?18O observations. COSMOiso very accurately reproduces the statistical distribution of ?18O in precipitation, and also the synoptic-scale spatial pattern and temporal evolution agree well with the measurements. Perpendicular to the front that triggers most of the rainfall during the event, the model simulates a gradient in the isotopic composition of the precipitation, with high ?18O values in the warm air and lower values in the cold sector behind the front. This spatial pattern is created through an interplay of large scale air mass advection, removal of heavy isotopes by precipitation at the front and microphysical interactions between rain drops and water vapour beneath the cloud base. This investigation illustrates the usefulness of high resolution, event-based model simulations for understanding the complex processes that cause synoptic-scale variability of the isotopic composition of atmospheric waters. In future research, this will be particularly beneficial in combination with laser spectrometric isotope observations with high temporal resolution.

Pfahl, S.; Wernli, H.; Yoshimura, K.

2012-02-01

198

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

199

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

2011-09-01

200

East Asian winter monsoon: results from eight AMIP models  

Microsoft Academic Search

.  ?This study evaluates simulations of the East Asian winter monsoon in eight GCMs that participated in the Atmospheric Model\\u000a Intercomparison Project (AMIP). In addition to validating the mean state of the winter monsoon, the cold surge and its transient\\u000a properties, which includes the frequency, intensity, preferred propagation tracks, and the evolution patterns of the surges,\\u000a are examined. GCM simulated temporal

Y. Zhang; K. R. Sperber; J. S. Boyle; M. Dix; L. Ferranti; A. Kitoh; K. M. Lau; K. Miyakoda; D. Randall; L. Takacs; R. Wetherald

1997-01-01

201

Isolation and functional characterization of cold-regulated promoters, by digitally identifying peach fruit cold-induced genes from a large EST dataset  

Microsoft Academic Search

BACKGROUND: Cold acclimation is the process by which plants adapt to the low, non freezing temperatures that naturally occur during late autumn or early winter. This process enables the plants to resist the freezing temperatures of winter. Temperatures similar to those associated with cold acclimation are also used by the fruit industry to delay fruit ripening in peaches. However, peaches

Andrés Tittarelli; Margarita Santiago; Andrea Morales; Lee A Meisel; Herman Silva

2009-01-01

202

Primary cold agglutinin disease: a case report.  

PubMed

Chronic cold agglutinin disease is a subgroup of auto-immune haemolytic anaemia. Primary cold agglutinin disease has traditionally been defined by the absence of any underlying or associated disease. It usually affects elderly. The term cold refers to the fact that the auto-antibody involved reacts with red cells poorly or not at all at 37 degrees C, whereas it reacts strongly at lower temperature. Here a case of severe pallor, jaundice and red colour urine in winter season for last 10 years diagnosed as a case of primary cold agglutinin disease is reported.The patient was managed conservatively. PMID:23738411

Das, Susanta Kumar; Ghosh, Amritava; Banerjee, Niloy; Khaskil, Sudarshan; Mukherjee, Sabya Sachi

2012-10-01

203

Front Matter: Volume 8911  

NASA Astrophysics Data System (ADS)

This PDF file contains the front matter associated with SPIE Proceedings Volume 8911, including the Title Page, Copyright information, Table of Contents, Introduction (if any), and Conference Committee listing.

Gu, Min; Yuan, Xiaocong; Qiu, Min

2013-08-01

204

Front Matter: Volume 8908  

NASA Astrophysics Data System (ADS)

This PDF file contains the front matter associated with SPIE Proceedings Volume 8908, including the Title Page, Copyright information, Table of Contents, Invited Panel Discussion, and Conference Committee listing.

SPIE, Proceedings of

2013-08-01

205

Front Matter: Volume 8910  

NASA Astrophysics Data System (ADS)

This PDF file contains the front matter associated with SPIE Proceedings Volume 8910, including the Title Page, Copyright information, Table of Contents, Introduction (if any), and Conference Committee listing.

Zhang, Lifu; Yang, Jianfeng

2013-08-01

206

Front Matter: Volume 8909  

NASA Astrophysics Data System (ADS)

This PDF file contains the front matter associated with SPIE Proceedings Volume 8909, including the Title Page, Copyright information, Table of Contents, Introduction (if any), and Conference Committee listing.

Rahm, Marco; Vodopyanov, Konstantin; Shi, Wei; Zhang, Cunlin

2013-08-01

207

Front Matter: Volume 8906  

NASA Astrophysics Data System (ADS)

This PDF file contains the front matter associated with SPIE Proceedings Volume 8906, including the Title Page, Copyright information, Table of Contents, Invited Panel Discussion, and Conference Committee listing.

SPIE, Proceedings of

2013-08-01

208

Front Matter: Volume 8808  

NASA Astrophysics Data System (ADS)

This PDF file contains the front matter associated with SPIE Proceedings Volume 8808, including the Title Page, Copyright information, Table of Contents, Invited Panel Discussion, and Conference Committee listing.

SPIE, Proceedings of

2013-09-01

209

Front Matter: Volume 8809  

NASA Astrophysics Data System (ADS)

This PDF file contains the front matter associated with SPIE Proceedings Volume 8809, including the Title Page, Copyright information, Table of Contents, Invited Panel Discussion, and Conference Committee listing.

SPIE, Proceedings of

2013-09-01

210

Front Matter: Volume 8609  

NASA Astrophysics Data System (ADS)

This PDF file contains the front matter associated with SPIE Proceedings Volume 8609, including the Title Page, Copyright information, Table of Contents, Introduction (if any), and Conference Committee listing.

2013-03-01

211

Front Matter: Volume 7017  

NASA Astrophysics Data System (ADS)

This PDF file contains the front matter associated with SPIE Proceedings Volume 7017, including the Title Page, Copyright information, Table of Contents, Introduction (if any), and the Conference Committee listing.

SPIE, Proceedings of

2008-07-01

212

The Store Front School.  

ERIC Educational Resources Information Center

Describes the Store Front School project, a program of cooperative education aimed at rekindling students' interest in school and helping them earn their diplomas. The school conducts classes in an office in a shopping mall where the students work. (ABB)

Forrest, Barbara

1986-01-01

213

Nuclear winter: the implications for civil defense  

SciTech Connect

It is generally believed possible for some range of heavy nuclear attacks directed against cities that significant but not lethal climate alteration will ensue for at least a few weeks. Three-dimensional global circulation models being developed and used at Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), and the National Center for Atmospheric Research for a reasonable attack size seem to be converging on a temperature depression of the order of 10 to 15/degree/C, averaged over all land areas of the temperate region of the northern hemisphere. Temperature depressions as large as 25/degree/C are predicted in the interiors of continents for attacks in the summertime. Winter wars produce temperature depressions of only a few degrees. The authors have drawn the following implications for civil defense of the possibility of nuclear winter: (1) Neither cold nor drought is likely to be a direct threat to human survival. (2) The principal threat of nuclear winter is to agriculture. (3) Nuclear winter does not present an entirely new threat from nuclear war to the United States or the Soviet Union. (4) The consequences of nuclear winter would fall more heavily on the Soviet Union.

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

1987-01-01

214

Air Masses and Fronts  

NSDL National Science Digital Library

In this activity, which builds on the previous activity 'Air Masses', students will examine sets of maps of air temperature and wind speed (prepared by the teacher) and learn to recognize fronts (transition zones between two dissimilar air masses). As they examine the maps, which show conditions spanning several hours of time, they will identify two distinct air masses, the frontal boundary, whether the front is moving in time and in what direction it is moving.

215

Early Childhood: The World in Winter.  

ERIC Educational Resources Information Center

Various winter activities and experiences for young children are suggested. These include a getting ready for winter walk in the fall, winter birds, winter clothing, traveling in winter, winter sky watch, and others. (JN)

McIntyre, Margaret, Ed.

1983-01-01

216

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 ...

Keller, Mrs.

2010-01-23

217

Investigation of Cold Overflow Over the Iceland/Faeroes Ridge.  

National Technical Information Service (NTIS)

Hydrographic data were analyzed to determine spatial and temporal variability of the overflow of cold, fresh Arctic water over the Iceland/Faeroes Ridge into the Iceland Basin during both winter and summer. Regions of frequent intermittent overflow were l...

P. A. Tunnicliffe

1990-01-01

218

Cold Fusion.  

ERIC Educational Resources Information Center

|Discusses ways of preparing school-building roofs for the winter season by paying attention to common problem areas. Also highlights the use of white elastomeric roof coatings, their benefits, and considerations when applying them. (GR)|

Dutton, Eileen; Salazar, Chris

1998-01-01

219

Thermoregulatory responses of young and older men to cold exposure  

Microsoft Academic Search

Summary  Nine young (20–25 years) and ten older (60–71 years) men, matched for body fatness and surface area :mass ratio, underwent cold tests in summer and winter. The cold tests consisted of a 60-min exposure, wearing only swimming trunks, to an air temperature of 17°C (both seasons) and 12°C (winter only). Rectal (T\\u000are) and mean skin (\\u000a$$\\\\overline T $$

Yoshimitsu Inoue; Mikio Nakao; Tsutomu Araki; Hiroyuki Ueda

1992-01-01

220

Intensification of Ocean Fronts by Down-Front Winds  

Microsoft Academic Search

Many ocean fronts experience strong local atmospheric forcing by down-front winds, that is, winds blowing in the direction of the frontal jet. An analytic theory and nonhydrostatic numerical simulations are used to demonstrate the mechanism by which down-front winds lead to frontogenesis. When a wind blows down a front, cross-front advection of density by Ekman flow results in a destabilizing

Leif N. Thomas; Craig M. Lee

2005-01-01

221

Adaptation related to cytokines in man: effects of regular swimming in ice-cold water  

Microsoft Academic Search

Summary The cytokine response after thermal stress (sauna + swimming in ice-cold water) was investigated in subjectively healthy persons. Two groups were studied at the end of the winter season: habitual and inexperi- enced winter swimmers. Blood was collected at rest, after a sauna bath and after a short swim in ice-cold water. Conventional methods and ELISA kits were used

B. Dugueand; E. Leppanen

222

Fronts in Large Marine Ecosystems  

Microsoft Academic Search

Oceanic fronts shape marine ecosystems; therefore front mapping and characterization are among the most important aspects of physical oceanography. Here we report on the first global remote sensing survey of fronts in the Large Marine Ecosystems (LME). This survey is based on a unique frontal data archive assembled at the University of Rhode Island. Thermal fronts were automatically derived with

Igor M. Belkin; Peter C. Cornillon; Kenneth Sherman

2009-01-01

223

Sea surface temperature variability of the Iceland-Faeroe Front  

NASA Astrophysics Data System (ADS)

Several advanced very high resolution radiometer (AVHRR) images with spatial resolution of 1.1-3.3 km, together with several concurrent aircraft-deployed expendable bathythermograph (AXBT) surveys and conductivity-temperature-depth (CTD) stations, from spring 1989 are used to describe the Iceland-Faeroe sea surface temperature (SST) front. In the AVHRR images, SST fronts are located by maximizing |?SST|. Single, large gradient segments of the SST front do exist, with some exceeding 100 km in length, indicating a multiple frontal structure. These single frontal lines are also segments where |?2SST| is small, and they can be followed uniquely by a single isotherm eastward from Iceland for a distance of 300 km. With a 35-km sampled AXBT survey, two small subsurface cold eddies were located south of the surface front in an area 170 km × 270 km east of Iceland. From a May 1987 AVHRR image on 1.1-km resolution, a population of seven such cold eddies are found between Iceland and the Faroes. They appear to be generated along the surface expression of the Iceland Faroes front and populate the northern slope of the Iceland-Faroes Ridge. Historical data from towed high-resolution instruments suggest that the cold eddies are ˜30-50 km in size and uplift the main thermocline by 150 m.

Niiler, Pearn P.; Piacsek, Steve; Neuberg, Lucas; Warn-Varnas, Alex

1992-11-01

224

Cold Intolerance  

MedlinePLUS

... Professionals Excerpt from the Handbook on the Late Effects of Poliomyelitis for Physicians and Survivors © Cold Intolerance Many polio survivors report that their feet have always been cold to the touch, their skin a purplish color. As they age, their limbs become more sensitive ...

225

Comment on 'Marine GIS: Identification of mesoscale oceanic thermal fronts  

Microsoft Academic Search

In this paper, we aim to clear up a significant conceptual error in the use of the ‘sink method’ as presented by Valavanis et al. (2005) for oceanic thermal front detection. We argue that the features identified by the authors in their paper are mostly cyclonic or cold ring eddies in the Aegean Sea.

F. J. Simmonds; X. H. Wang; B. G. Lees

2009-01-01

226

The interannual variability of East Asian Winter Monsoon and its relation to the summer monsoon  

Microsoft Academic Search

Based on the NCEP\\/ NCAR reanalysis data the interannual variability of the East Asian winter mon-soon (EAWM) is studied with\\u000a a newly defined EAWM intensity index. The marked features for a strong (weak) winter monsoon include strong (weak) northerly\\u000a winds along coastal East Asia, cold (warm) East Asian continent and surrounding sea and warm (cold) ocean from the subtropical\\u000a central

Chen Wen; Hans-F. Graf; Huang Ronghui

2000-01-01

227

Effects of Surface Drag on Fronts within Numerically Simulated Baroclinic Waves  

Microsoft Academic Search

A comparative analysis of simulations of baroclinic waves with and without surface drag is presented, with particular reference to surface features. As in recent studies, the present simulations show that, compared to simulations with no drag, those with surface drag are less inclined to develop a secluded warm sector, and that drag weakens the warm front while the cold front

Richard Rotunno; William C. Skamarock; Chris Snyder

1998-01-01

228

Automobile front body construction  

SciTech Connect

This patent describes an automobile front body structure having an engine compartment and also having a pair of spaced first longitudinal frames extending beneath the engine compartment in a direction longitudinally of an automobile and connected at a rear end to a floor panel. The structure comprises: suspension arm support members secured to front ends of the first longitudinal frames, respectively, for the support of left-hand and right-hand suspension arms; and a transverse connecting member extending between the first longitudinal frames in a direction widthwise of the automobile and having its opposite ends connected to the respective support members.

Harasaki, H.

1987-06-23

229

Lakota Winter Counts  

NSDL National Science Digital Library

Different human societies across the millennia have sought to record their histories in a multitude of ways, and the Lakota people of the Northern Plains elected to record their experiences through what are known as winter counts. These winter counts are essentially histories or calendars in which events are recorded by pictures, with one picture for each year. These rather fascinating documents were used in conjunction with extensive oral histories, and as such, most of these events were widely known and recognized by a majority of the Lakota. This particular website from the National Anthropological Archives at the Smithsonian National Museum of Natural History allows visitors to view these winter counts, learn more about the Lakota, and view interviews with contemporary Lakota people about the winter counts. The site also contains an audio glossary and a number of helpful resources for educators.

230

Yuma Winter Microclimate.  

National Technical Information Service (NTIS)

This study consists of an analysis of winter temperatures at and near the ground and wind velocities at standard heights, at three sites within Yuma Proving Ground. Two of the sites were selected for their representativeness of surface types characterizin...

H. L. Ohman R. L. Pratt

1966-01-01

231

Concussion in Winter Sports  

MedlinePLUS

... to... Añadir en... Favorites Delicious Digg Google Bookmarks Concussion in Winter Sports Get prepared for concussions on and off the ... professionals Learn more about CDC's Heads Up initiatives . Concussion in Sports NFL/CDC Poster for Professional Players and Young ...

232

Winter Weather Emergencies  

MedlinePLUS

... there are no guarantees of safety during winter weather emergencies, you can take actions to protect yourself. You should have a disaster plan. Being prepared can help reduce fear, anxiety and losses. Centers for Disease Control and Prevention

233

Damage and compensatory effects of winter drought on winter wheat  

Microsoft Academic Search

Field experiments were carried out to investigate the damage and compensatory effects of winter drought on winter wheat. The results of the study show that, after winter drought, the growth and development of winter wheat, display obviously dual effects of damage and compensatory. The productive tiller percentage increases while spike number per hectare reduces. Plant height does not change significantly,

Xiu-Shan Tan; Bao-Xing Ye; Jian-Jie Bi

2011-01-01

234

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 ...

Haight, Jennifer

2010-02-22

235

Forecasting minimum temperature during winter and maximum temperature during summer at Delhi  

Microsoft Academic Search

A knowledge of minimum temperature during winter and maximum temperature during summer is a very useful for individuals, as well as for organisations whose workers and machines have to operate in the open, e.g. the armed forces, railways, roadways, tourism, etc. Accurate forecasts of minimum temperature during winter help in the prediction of cold-wave conditions and those of maximum temperature

U. C. Mohanty; N. Ravi; O. P. Madan; R. K. Paliwal

1997-01-01

236

Stream Gradient-Related Movement and Growth of Atlantic Salmon Parr during Winter  

Microsoft Academic Search

There has been considerable focus on winter studies of Atlantic salmon Salmo salar parr during the last two decades. However, a lack of knowledge exists about the linkage between the physical conditions, including ice, and parr behavior in flow environments during the cold season. In this study, the movement and growth of Atlantic salmon parr were studied during winter in

Morten Stickler; Eva C. Enders; Curtis J. Pennell; David Cote; Knut Alfredsen; David A. Scruton

2008-01-01

237

Plasticity in body temperature and metabolic capacity sustains winter activity in a small endotherm ( Rattus fuscipes)  

Microsoft Academic Search

Small mammals that remain active throughout the year at a constant body temperature have a much greater energy and food requirement in winter. Lower body temperatures in winter may offset the increased energetic cost of remaining active in the cold, if cellular metabolism is not constrained by a negative thermodynamic effect. We aimed to determine whether variable body temperatures can

Elsa J. Glanville; Frank Seebacher

2010-01-01

238

Antifreeze Proteins in Winter Rye Leaves Form Oligomeric Complexes1  

PubMed Central

Antifreeze proteins (AFPs) similar to three pathogenesis-related proteins, a glucanase-like protein (GLP), a chitinase-like protein (CLP), and a thaumatin-like protein (TLP), accumulate during cold acclimation in winter rye (Secale cereale) leaves, where they are thought to modify the growth of intercellular ice during freezing. The objective of this study was to characterize the rye AFPs in their native forms, and our results show that these proteins form oligomeric complexes in vivo. Nine proteins were separated by native-polyacrylamide gel electrophoresis from apoplastic extracts of cold-acclimated winter rye leaves. Seven of these proteins exhibited multiple polypeptides when denatured and separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. After isolation of the individual proteins, six were shown by immunoblotting to contain various combinations of GLP, CLP, and TLP in addition to other unidentified proteins. Antisera produced against individual cold-induced winter rye GLP, CLP, and TLP all dramatically inhibited glucanase activity in apoplastic extracts from cold-acclimated winter rye leaves, and each antiserum precipitated all three proteins. These results indicate that each of the polypeptides may be exposed on the surface of the protein complexes. By forming oligomeric complexes, AFPs may form larger surfaces to interact with ice, or they may simply increase the mass of the protein bound to ice. In either case, the complexes of AFPs may inhibit ice growth and recrystallization more effectively than the individual polypeptides.

Yu, Xiao-Ming; Griffith, Marilyn

1999-01-01

239

Energy-efficient facelift prepares plant for Wisconsin winter  

SciTech Connect

After investing several years ''energizing'' the interior operations of its processing plant, R-Line Foods personnel invested in an exterior facelift which added a thermal envelope of insulation to the building. Radiating energy more evenly, the new facade eliminated cold winter drafts and improved employee comfort.

Not Available

1984-09-01

240

Warmest winter in history  

NSDL National Science Digital Library

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

Payne, Laura X.

241

Order parameter equations for front transitions: Nonuniformly curved fronts  

NASA Astrophysics Data System (ADS)

Kinematic equations for the motion of slowly propagating, weakly curved fronts in bistable media are derived. The equations generalize earlier derivations where algebraic relations between the normal front velocity and its curvature are assumed. Such relations do not capture the dynamics near nonequilibrium Ising-Bloch (NIB) bifurcations, where transitions between counterpropagating Bloch fronts may spontaneously occur. The kinematic equations consist of coupled integro-differential equations for the front curvature and the front velocity, the order parameter associated with the NIB bifurcation. They capture the NIB bifurcation, the instabilities of Ising and Bloch fronts to transverse perturbations, the core structure of a spiral wave, and the dynamic process of spiral wave nucleation.

Hagberg, Aric; Meron, Ehud

1998-11-01

242

The Front Door.  

ERIC Educational Resources Information Center

|A campus's physical presence typically serves as the "front door" for key audiences and important constituencies, creating an initial and often enduring image within the community from which it hopes to attract students, faculty, and staff. Effective real-estate management presents opportunities to design a more inviting welcome sign.…

Bulls, Herman E.; Greenberger, Jeffrey S.

1998-01-01

243

At the ideological front  

Microsoft Academic Search

In an effort to understand the critical culture of the 1930s and Kenneth Burke's place in it, this essay explores the meaning of the thirties, the role the American Communist Party played during this period, popular front politics, and the lens of McCarthyism through which these issues have been refracted. Burke's book Permanence and Change was first published in 1935.

Philip C. Wander

1991-01-01

244

Glaciology: From the front  

NASA Astrophysics Data System (ADS)

The causes of recent dynamic thinning of Greenland's outlet glaciers have been debated. Realistic simulations suggest that changes at the marine fronts of these glaciers are to blame, implying that dynamic thinning will cease once the glaciers retreat to higher ground.

Price, Stephen

2009-02-01

245

Front Range Branch Officers  

NASA Astrophysics Data System (ADS)

The Front Range Branch of AGU has installed officers for 1990: Ray Noble, National Center for Atmospheric Research, chair; Sherry Oaks, U.S. Geological Survey, chair-elect; Howard Garcia, NOAA, treasurer; Catharine Skokan, Colorado School of Mines, secretary. JoAnn Joselyn of NOAA is past chair. Members at large are Wallace Campbell, NOAA; William Neff, USGS; and Stephen Schneider, NCAR.

246

Winter precipitation change in South China in recent decades  

NASA Astrophysics Data System (ADS)

Precipitation change is one of important climate researches in China, but winter precipitation variation in South China has not been studied so frequently. In China, it is rainy when hot; so summer precipitation is usually one focus in research, esp. in South China. However, winter precipitation and its change influence people profoundly in South China, also. The most recent example is what happened over South China in winter 2008. In this winter, millions of people suffered from the unusual cold and snowy winter. It led to huge loss in economy and traffic as well. Roads closed and railway stations were jammed and crowded with people; many planes were grounded for heavy snow and bad weather. Transmission lines faulted in the mountains. The ommunication signals were affected. Everyday food supply including vegetables and meats had to be delayed or interrupted. In some city even water supply was interrupted. And garbage in the city was piled up. Just in this winter the snow depth and coverage area in many places in South China broke or equaled the historical records. In fact, it isn't the only one unusual winter precipitation event in South China. Since 1950s, several freezing and snowy winters struck the South in China. In this research, winter precipitation change in recent years in South China has been discussed based on the precipitation observations. The associated large scale atmospheric circulation change is also analyzed. It is found that snowy winter in South China hardly comes in most periods of 2000s, but in recent decades this heavy snow in winter has appeared several times as observations shows. This phenomenon could be related to the large scale atmospheric circulation change.

Cai, Jingning

2013-04-01

247

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; Jürgen Schmidt

2005-01-01

248

Winter North Atlantic Oscillation, temperature and ischaemic heart disease mortality in three English counties  

NASA Astrophysics Data System (ADS)

As cold weather is an ischaemic heart disease (IHD) risk factor, year-to-year variations of the level of IHD mortality may be partly determined by inter-annual variations in winter climate. This paper investigates whether there is any association between the level of IHD mortality for three English counties and the winter North Atlantic Oscillation (NAO), which exerts a fundamental control on the nature of the winter climate over Western Europe. Correlation and regression analysis was used to explore the nature of the association between IHD mortality and a climate index (CI) that represents the interaction between the NAO and temperature across England for the winters 1974 1975 to 1989 1999. Statistically significant inverse associations between the CI and the level of IHD mortality were found. Generally, high levels of winter IHD mortality are associated with a negative CI, which represents winters with a strong negative phase of the NAO and anomalously low temperatures across England. Moreover, the nature of the CI in the early stages of winter appears to exert a fundamental control on the general level of winter IHD mortality. Because winter climate is able to explain a good proportion of the inter-annual variability of winter mortality, long-lead forecasting of winter IHD mortality appears to be a possibility. The integration of climate-based health forecasts into decision support tools for advanced general winter emergency service and capacity planning could form the basis of an effective adaptive strategy for coping with the health effects of harsh winters.

McGregor, Glenn R.

2005-01-01

249

Surface wind response to oceanic fronts  

NASA Astrophysics Data System (ADS)

The response of surface winds to ocean fronts characterized by sharp gradients in both sea surface temperature (SST) and ocean currents was analyzed using scatterometer (NSCAT and QuikSCAT) wind data and Gulf Stream path positions in conjunction with simulations made with the Pennsylvania State University (PSU)-National Center for Atmospheric Research (NCAR) Mesoscale Model (MM5). All match-ups, between each scatterometer pass and the Gulf Stream path, were visually examined and only those for which the wind field was free of atmospheric fronts or large curvature over a reasonably straight segment of the Gulf Stream were selected. Ten match-ups met these criteria for the period studied from 16 September 1996 to 29 June 1997 for NSCAT and from 24 July 1999 to 31 December 2000 for QuikSCAT. Changes in the modeled surface wind field across the front in each of the ten cases agree well with changes in the observed winds. Our findings suggest that the perturbation pressure gradient resulting from the thermal forcing by the front accounts for the decrease in wind speed when moving from warm to cold water and the increase observed in the converse. In the cases examined, the adjustment of the surface wind to the front occurred as a result of the vertical motion induced by horizontal divergence/convergence and advection in the marine atmospheric boundary layer (MABL). The dynamical forcing associated with strong surface currents is also shown to modify scatterometer-derived winds. Finally the numerical simulations suggest that the dynamical and thermal effects are very nearly additive.

Song, Qingtao; Cornillon, Peter; Hara, Tetsu

2006-12-01

250

9. DETAIL OF INTERIOR OF FRONT PORCH SHOWING FRONT ENTRY ...  

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

9. DETAIL OF INTERIOR OF FRONT PORCH SHOWING FRONT ENTRY (LEFT) AND BLANK WALL (CENTER) CORRESPONDING TO LOCATION OF INTERIOR VAULTS. VIEW TO SOUTHEAST. - Boise Project, Boise Project Office, 214 Broadway, Boise, Ada County, ID

251

4. BARRACKS, WITH PARKING LOT IN FRONT, FRONT AND RIGHT ...  

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

4. BARRACKS, WITH PARKING LOT IN FRONT, FRONT AND RIGHT SIDES, LOOKING SOUTH. - NIKE Missile Base SL-40, Barracks No. 2, North end of base, southeast of Barracks No. 1 & northeast of Mess Hall, Hecker, Monroe County, IL

252

1. BARRACKS, WITH PARKING LOT IN FRONT, FRONT, LOOKING SOUTHWEST. ...  

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

1. BARRACKS, WITH PARKING LOT IN FRONT, FRONT, LOOKING SOUTHWEST. - NIKE Missile Base SL-40, Barracks No. 2, North end of base, southeast of Barracks No. 1 & northeast of Mess Hall, Hecker, Monroe County, IL

253

35. EAST FRONT OF POWERHOUSE AND CAR BARN: East front ...  

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

35. EAST FRONT OF POWERHOUSE AND CAR BARN: East front of powerhouse and car barn. 'Annex' is right end of building. - San Francisco Cable Railway, Washington & Mason Streets, San Francisco, San Francisco County, CA

254

PAF1-complex-mediated histone methylation of FLOWERING LOCUS C chromatin is required for the vernalization-responsive, winter-annual habit in Arabidopsis  

Microsoft Academic Search

The winter-annual habit (which typically involves a requirement for exposure to the cold of winter to flower in the spring) in Arabidopsis thaliana is mainly due to the repression of flowering by relatively high levels of FLC expression. Exposure to prolonged cold attenuates FLC expression through a process known as vernalization and thus permits flowering to occur in the spring.

Yuehui He; Mark R. Doyle; Richard M. Amasino

2004-01-01

255

Winter habitat selection by a montane forest bird assemblage: the effects of solar radiation  

Microsoft Academic Search

A relationship between sunlight and bird abundance in cold climates may seem intuitive and perhaps obvi- ous. However, there is, surprisingly, little or no evidence to support it. We investigated the effects of solar radiation on the winter abundance of insectivorous birds inhabiting a Mediterranean montane forest with a high frequency of cold, cloudless days. We censused birds by ear

Daniel L. Huertas; José A. Díaz

2001-01-01

256

Extratropical Atmospheric Response to Equatorial Atlantic Cold Tongue Anomalies  

Microsoft Academic Search

Abstract The extra-tropical atmospheric response to the equatorial cold tongue mode,in the Atlantic Ocean has been investigated with the coupled ocean-atmosphere model SPEEDO. Similar as in the observations the model simulates a lagged co-variability between the equatorial cold tongue mode,during late boreal summer,and the east Atlantic pattern a few months later in early winter. The equatorial cold tongue mode,attains its

Reindert J. Haarsma; Wilco Hazeleger

2007-01-01

257

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 ...

S., Tasia

2010-09-23

258

When hot water freezes before cold  

Microsoft Academic Search

I suggest that the origin of the Mpemba effect (the freezing of hot water before cold) is due to freezing-point depression by solutes, either gaseous or solid, whose solubility decreases with increasing temperature so that they are removed when water is heated. The solutes are concentrated ahead of the freezing front by zone refining in water that has not been

J. I. Katz

2009-01-01

259

Cold injuries.  

PubMed

Exposure to cold can produce a variety of injuries that occur as a result of man's inability to adapt to cold. These injuries can be divided into localized injury to a body part, systemic hypothermia, or a combination of both. Body temperature may fall as a result of heat loss by radiation, evaporation, conduction, and convection. Hypothermia or systemic cold injury occurs when the core body temperature has decreased to 35 degrees C (95 degrees F) or less. The causes of hypothermia are either primary or secondary. Primary, or accidental, hypothermia occurs in healthy individuals inadequately clothed and exposed to severe cooling. In secondary hypothermia, another illness predisposes the individual to accidental hypothermia. Hypothermia affects multiple organs with symptoms of hypothermia that vary according to the severity of cold injury. The diagnosis of hypothermia is easy if the patient is a mountaineer who is stranded in cold weather. However, it may be more difficult in an elderly patient who has been exposed to a cold environment. In either case, the rectal temperature should be checked with a low-reading thermometer. The general principals of prehospital management are to (1) prevent further heat loss, (2) rewarm the body core temperature in advance of the shell, and (3) avoid precipitating ventricular fibrillation. There are two general techniques of rewarming--passive and active. The mechanisms of peripheral cold injury can be divided into phenomena that affect cells and extracellular fluids (direct effects) and those that disrupt the function of the organized tissue and the integrity of the circulation (indirect effects). Generally, no serious damage is seen until tissue freezing occurs. The mildest form of peripheral cold injury is frostnip. Chilblains represent a more severe form of cold injury than frostnip and occur after exposure to nonfreezing temperatures and damp conditions. Immersion (trench) foot, a disease of the sympathetic nerves and blood vessels in the feet, is observed in shipwreck survivors or in soldiers whose feet have been wet, but not freezing, for long periods. Patients with frostbite frequently present with multisystem injuries (e.g., systemic hypothermia, blunt trauma, substance abuse). The freezing of the corneas has been reported to occur in individuals who keep their eyes open in high wind-chill situations without protective goggles (e.g., snowmobilers, cross-country skiers). PMID:15715518

Long, William B; Edlich, Richard F; Winters, Kathryne L; Britt, L D

2005-01-01

260

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.

261

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 ...

Miller, Aubree

2009-09-28

262

Nuclear Winter: Implications for civil defense  

SciTech Connect

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

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

1988-05-01

263

A stochastic model of chromatin modification: cell population coding of winter memory in plants.  

PubMed

Biological memory, a sustained cellular response to a transient stimulus, has been found in many natural systems. The best example in plants is the winter memory by which plants can flower in favorable conditions in spring. For this winter memory, epigenetic regulation of FLOWERING LOCUS C (FLC), which acts as a floral repressor, plays a key role. Exposure to prolonged periods of cold results in the gradual suppression of FLC, which allows plants to measure the length of cold and to flower only after a sufficiently long winter. Although many genes involved in histone modifications have been isolated, molecular mechanisms of winter memory are not well understood. Here, we develop a model for chromatin modification, in which the dynamics of a single nucleosome are aggregated to on/off behavior of FLC expression at the cellular level and further integrated to a change of FLC expression at the whole-plant level. We propose cell-population coding of winter memory: each cell is described as a bistable system that shows heterogeneous timing of the transition from on to off in FLC expression under cold and measures the length of cold as the proportion of cells in the off state. This mechanism well explains robust FLC regulation and stable inheritance of winter memory after cell division in response to noisy signals. Winter memory lasts longer if deposition of the repressive histone mark occurs faster. A difference in deposition speed would discriminate between stable maintenance of FLC repression in annuals and transient expression in perennials. PMID:22381539

Satake, Akiko; Iwasa, Yoh

2012-02-23

264

The East Greenland Polar Front in autumn  

NASA Astrophysics Data System (ADS)

Closely spaced salinity and temperature measurements in the region of the East Greenland Polar Front from 75°N to 79°N in October-November 1981 are presented. The Return Atlantic Current (RAC), having a core of relatively warm and saline Atlantic Intermediate Water (AIW) (T = 0.5° to 3.0°C, S = 34.9 to 35.0), was found everywhere along a steep front separating it from the colder, fresher Polar Water. A narrow frontal jet was found to have velocities greater than 0.80 m/s where the station density was great enough to resolve its concentrated character. Notable fine structure was present, especially in the warm AIW just east of the front. A cold, saline water, forming a knee in the temperature-salinity correlation, was present in the upper margins of the RAC. The knee is formed primarily by warm AIW or Atlantic water flowing under the upper layers of water flowing from the Arctic Ocean. Calculations are presented to show that an initially isothermal underflow could be modified to a thick thermocline by double diffusion. Calculations of the rate of cooling of fine-structure elements by double diffusion indicate that the fine structure would have a limited lifetime (about 12 days) if its waters were not continually replenished.

Paquette, Robert G.; Bourke, Robert H.; Newton, John F.; Perdue, William F.

1985-05-01

265

Winter Weather FAQs  

MedlinePLUS

... lower your body temperature. What is the best clothing for cold weather? Adults and children should wear: ... coat and shoes several layers of loose-fitting clothing Be sure the outer layer of your clothing ...

266

Variation in the Hatteras Front density and velocity structure Part 2: Historical setting  

NASA Astrophysics Data System (ADS)

On the continental shelf near Cape Hatteras, cool fresh Mid-Atlantic Bight and warm salty South Atlantic Bight shelf waters converge alongshelf 90% of the time, causing strong alongshelf gradients in temperature and salinity known as the ‘Hatteras Front’. The resulting density gradient supports strong shoreward velocities in the cross-shelf oriented ‘nose’, of the Front in wintertime. To investigate further, the Frontal Interactions near Cape Hatteras (FINCH) project used shipboard ADCP and a towed undulating CTD to examine Hatteras Front property, density and velocity fields in August 2004, January 2005, and July 2005. Strong property gradients were encountered across the nose of the Hatteras Front in all cases, but the density gradient, dynamic height gradient, and observed along-front cross-shelf velocities evolved in time. FINCH along-Front velocities were strong and shoreward in fall and winter, and weakly mixed shoreward and seaward in July. Several archived data sets were examined, and demonstrate that the density evolution and wind forcing seen in FINCH are characteristic of other years. Evidence suggests the width of the Hatteras Front does not vary dramatically in time, so that consistently large fall and winter density contrast across the Front implies consistently large shoreward velocities along it in winter. Weak density contrasts across the Hatteras Front in spring suggest the magnitude and sign of springtime density gradients and along-Front velocities could vary interannually. Recruitment success of commercially important stocks on the shelf that depend on cross-shelf transport may thus be affected year to year.

Savidge, Dana K.; Austin, Jay A.; Blanton, Brian O.

2013-02-01

267

From genotype to phenotype: unraveling the complexities of cold adaptation in forest trees  

Microsoft Academic Search

Adaptation to winter cold in temperate and boreal trees involves complex genetic, physiological, and devel- opmental processes. Genecological studies demonstrate the existence of steep genetic clines for cold adaptation traits in relation to environmental (mostly temperature related) gradients. Population differentiation is generally stronger for cold adaptation traits than for other quantitative traits and allozymes. Therefore, these traits appear to be

Glenn T. Howe; Sally N. Aitken; David B. Neale; Kathleen D. Jermstad; Nicholas C. Wheeler; Tony H. H. Chen

2003-01-01

268

COLD TRAP  

DOEpatents

An improved linear-flow cold trap is designed for highvacuum applications such as mitigating back migration of diffusion pump oil moiecules. A central pot of liquid nitrogen is nested within and supported by a surrounding, vertical, helical coil of metai sheet, all enveloped by a larger, upright, cylindrical, vacuum vessel. The vertical interstices between successive turns of the coil afford lineal, axial, high-vacuum passages between open mouths at top and bottom of said vessel, while the coil, being cold by virtue of thermal contact of its innermost turn with the nitrogen pot, affords expansive proximate condensation surfaces. (AEC)

Milleron, N.

1963-03-12

269

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

270

The News. Winter 2007  

ERIC Educational Resources Information Center

|This Winter 2007 quarterly newsletter from the Community College League of California includes: (1) Incumbents: Some Win, Some Lose in November Trustee Elections; (2) Voters Approve $2 Billion in Bonds; (3) Photos from the "Together We Can" conference; (4) Report, Media Criticize Transfer, Completion Rates and Colleges; (5) District Leader…

Giles, Ray, Ed.

2007-01-01

271

Teaching Ecology in Winter.  

ERIC Educational Resources Information Center

|Presents ideas for teaching ecology in the winter. Suggested topic areas or units include snow insulation and density, snowflakes and snow crystals, goldenrod galls, bird behavior, survival techniques, bacteriology and decomposition, trees and keying, biomass and productivity, pollution, and soil organisms. A sample student activity sheet is…

Clearing: Nature and Learning in the Pacific Northwest, 1984

1984-01-01

272

Unusual Winter Storm, Hawaii.  

National Technical Information Service (NTIS)

From January 8 to 11, 1980, the Hawaiian Islands experienced some of the most severe weather from a winter storm in recent years. Even though rainfall was over 20 inches in some places, the most noteworthy and damaging aspects of this storm episode were t...

H. E. Rosendal

1980-01-01

273

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

274

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.

275

Winter- and summertime continental influences on tropospheric O3 and CO observed by TES over the western North Atlantic Ocean  

NASA Astrophysics Data System (ADS)

The distributions of tropospheric ozone (O3) and carbon monoxide (CO), and the synoptic factors regulating these distributions over the western North Atlantic Ocean during winter and summer were investigated using profile retrievals from the Tropospheric Emission Spectrometer (TES) for 2004-2006. Seasonal composites of TES retrievals, reprocessed to remove the influence of the a priori on geographical and seasonal structure, exhibited strong seasonal differences. At the 681 hPa level during winter months of December, January and February (DJF) the composite O3 mixing ratios were uniformly low (~45 ppbv), but continental export was evident in a channel of enhanced CO (100-110 ppbv) flowing eastward from the US coast. In summer months June, July, and August (JJA) O3 mixing ratios were variable (45-65 ppbv) and generally higher due to increased photochemical production. The summer distribution also featured a channel of enhanced CO (95-105 ppbv) flowing northeastward around an anticyclone and exiting the continent over the Canadian Maritimes around 50° N. Offshore O3-CO slopes were generally 0.15-0.20 mol mol-1 in JJA, indicative of photochemical O3 production. Composites for 4 predominant synoptic patterns or map types in DJF suggested that export to the lower free troposphere (681 hPa level) was enhanced by the warm conveyor belt airstream of mid-latitude cyclones while stratospheric intrusions increased TES O3 levels at 316 hPa. A major finding in the DJF data was that offshore 681 hPa CO mixing ratios behind cold fronts could be enhanced up to >150 ppbv likely by lofting from the surface via shallow convection resulting from rapid destabilization of cold air flowing over much warmer ocean waters. In JJA composites for 3 map types showed that the general export pattern of the seasonal composites was associated with a synoptic pattern featuring the Bermuda High. However, weak cyclones and frontal troughs could enhance offshore 681 hPa CO mixing ratios to >110 ppbv with O3-CO slopes >0.50 mol mol-1 south of 45° N. Intense cyclones, which were not as common in the summer, enhanced export by lofting of boundary layer pollutants from over the US and also provided a possible mechanism for transporting pollutants from boreal fire outflow southward to the US east coast. Overall, for winter and summer the TES retrievals showed substantial evidence of air pollution export to the western North Atlantic Ocean with the most distinct differences in distribution patterns related to strong influences of mid-latitude cyclones in winter and the Bermuda High anticyclone in summer.

Hegarty, J.; Mao, H.; Talbot, R.

2010-04-01

276

Factors affecting outdoor exposure in winter: population-based study.  

PubMed

The extent of outdoor exposure during winter and factors affecting it were examined in a cross-sectional population study in Finland. Men and women aged 25-74 years from the National FINRISK 2002 sub-study (n=6,591) were queried about their average weekly occupational, leisure-time and total cold exposure during the past winter. The effects of gender, age, area of residence, occupation, ambient temperature, self-rated health, physical activity and education on cold exposure were analysed. The self-reported median total cold exposure time was 7 h/week (8 h men, 6 h women),<1 h/week (2 h men, 0 h women) at work, 4 h/week (5 h men, 4 h women) during leisure time and 1 h/week (1 h men, 1.5 h women) while commuting to work. Factors associated with increased occupational cold exposure among men were: being employed in agriculture, forestry and industry/mining/construction or related occupations, being less educated and being aged 55-64 years. Factors associated with increased leisure-time cold exposure among men were: employment in industry/mining/construction or related occupations, being a pensioner or unemployed, reporting at least average health, being physically active and having college or vocational education. Among women, being a housewife, pensioner or unemployed and engaged in physical activity increased leisure-time cold exposure, and young women were more exposed than older ones. Self-rated health was positively associated with leisure time cold exposure in men and only to a minor extent in women. In conclusion, the subjects reported spending 4% of their total time under cold exposure, most of it (71%) during leisure time. Both occupational and leisure-time cold exposure is greater among men than women. PMID:16788837

Mäkinen, Tiina M; Raatikka, Veli-Pekka; Rytkönen, Mika; Jokelainen, Jari; Rintamäki, Hannu; Ruuhela, Reija; Näyhä, Simo; Hassi, Juhani

2006-06-21

277

Cold War  

NSDL National Science Digital Library

Cold War is a major, 24-part series directed by renowned documentary filmmaker Jeremy Isaacs that recently premiered on CNN and BBC2. Whether or not this series will become "the definitive account of the Cold War" remains to be seen, but the research that has made it possible is quite impressive. This feature-filled, comprehensive site complements the series by offering, among other things, video previews and multimedia recaps of each episode; video, audio, and text excerpts from nearly 100 interviews filmed for the series; text from archival documents and contemporaneous Time and Russian newspaper stories; in-depth sections on Cold War culture; and a Knowledge Bank section containing a glossary, "Cold Warrior" profiles, related links, and a chronology. Additional resources include a classroom guide to the series, online Shockwave quiz games, and an online discussion group. As large as it is now, the site will continue to expand and add new features as the series progresses over the next three months.

278

Ethylene Induces Antifreeze Activity in Winter Rye Leaves1  

PubMed Central

Antifreeze activity is induced by cold temperatures in winter rye (Secale cereale) leaves. The activity arises from six antifreeze proteins that accumulate in the apoplast of winter rye leaves during cold acclimation. The individual antifreeze proteins are similar to pathogenesis-related proteins, including glucanases, chitinases, and thaumatin-like proteins. The objective of this study was to study the regulation of antifreeze activity in response to ethylene and salicyclic acid, which are known regulators of pathogenesis-related proteins induced by pathogens. Nonacclimated plants treated with salicylic acid accumulated apoplastic proteins with no antifreeze activity. In contrast, when nonacclimated plants were exposed to ethylene, both antifreeze activity and the concentration of apoplastic protein increased in rye leaves. Immunoblotting revealed that six of the seven accumulated apoplastic proteins consisted of two glucanases, two chitinases, and two thaumatin-like proteins. The ethylene-releasing agent ethephon and the ethylene precursor 1-aminocyclopropane-1-carboxylate also induced high levels of antifreeze activity at 20°C, and this effect could be blocked by the ethylene inhibitor AgNO3. When intact rye plants were exposed to 5°C, endogenous ethylene production and antifreeze activity were detected within 12 and 48 h of exposure to cold, respectively. Rye plants exposed to drought produced both ethylene and antifreeze activity within 24 h. We conclude that ethylene is involved in regulating antifreeze activity in winter rye in response to cold and drought.

Yu, Xiao-Ming; Griffith, Marilyn; Wiseman, Steven B.

2001-01-01

279

The isotopic composition of precipitation from a winter storm - a case study with the limited-area model COSMOiso  

NASA Astrophysics Data System (ADS)

Stable water isotopes are valuable tracers of the atmospheric water cycle, and potentially provide useful information also on weather-related processes. In order to further explore this potential, the water isotopes H218O and HDO are incorporated into the limited-area weather forecast and climate model COSMO. The new COSMOiso model includes an advanced microphysical scheme, a convection parameterisation and non-hydrostatic dynamics that facilitate simulations from sub-kilometre to synoptic spatial scales. In a first case study, the model is applied for simulating a winter storm event in January 1986 over the eastern United States associated with intense frontal precipitation. The modelled isotope ratios in precipitation and water vapour are compared to spatially distributed ?18O observations from a study by Gedzelman and Lawrence (1990). COSMOiso very accurately reproduces the statistical distribution of ?18O in precipitation, and also the synoptic-scale spatial pattern and temporal evolution agree well with the measurements. Deviations at single stations can partly be attributed to errors in the representation of mesoscale atmospheric structures in the model. Grounded on this overall meteorological evaluation, the model is then used for investigating the physical processes causing the synoptic-scale variability of ?18O during the selected event. Perpendicular to the front that triggers most of the rainfall, COSMOiso simulates a gradient in the isotopic composition of the precipitation, with high ?18O values in the warm air to the east and lower values in the cold sector behind the front. This spatial gradient is connected to a temporal evolution with high ?18O values in the beginning and a decrease later on at locations where the front passes by. Two major processes are identified that contribute to creating the spatial pattern. First, the advection of cold, depleted water vapour to the west of the front and warm, more enriched vapour further to the east, in concert with the progressive removal of heavy isotopes by precipitation in the frontal band, cause a large scale west-to-east gradient of ?18O of vapour and precipitation. Second, this large scale pattern is modulated by microphysical effects, namely the isotope fractionation and equilibration during the interaction of rain drops and water vapour beneath the cloud base. This investigation illustrates the usefulness of high resolution, event-based model simulations for understanding the complex processes that cause synoptic-scale variability of the isotopic composition of atmospheric waters. In future research, this will be particularly beneficial in combination with laser spectrometric isotope observations with high temporal resolution.

Pfahl, S.; Wernli, H.; Yoshimura, K.

2012-04-01

280

Simple front tracking  

SciTech Connect

A new and simplified front tracking algorithm has been developed as an aspect of the extension of this algorithm to three dimensions. Here the authors emphasize two main results: (1) a simplified description of the microtopology of the interface, based on interface crossings with cell block edges, and (2) an improved algorithm for the interaction of a tracked contact discontinuity with an untracked shock wave. For the latter question, they focus on the post interaction jump at the contact, which is a purely 1D issue. Comparisons to other methods, including the level set method, are included.

Glimm, J.; Grove, J.W.; Li, X.; Zhao, N.

1999-04-01

281

Russian winter wheat mosaic virus  

Technology Transfer Automated Retrieval System (TEKTRAN)

The chapter contains a description of the Winter wheat (Russian) mosaic disease symptoms, transmission and occurrence. Characteristics of the disease agent, Winter wheat (Russian) mosaic virus are outlined, as are control measures....

282

Surface wind response to oceanic fronts  

NASA Astrophysics Data System (ADS)

The surface wind response in mesoscale to oceanic front was analyzed by using a combination of scatterometer (NSCAT and QuikSCAT) wind data and Advanced Very High Resolution Radiometer (AVHRR) sea surface temperature (SST) data in conjunction with numerical simulations made with Pennsylvania State University (PSU)-National Center for Atmospheric Research (NCAR) Mesoscale Model (MM5). MM5 simulations of the response of the marine atmospheric boundary layer (MABL) to a sharp SST front are compared with observations made during the Frontal Air-Sea Interaction Experiment (FASINEX) in the North Atlantic. The fully three-dimensional (3D) MM5 with the Medium-Range Forecast (MRF) boundary-layer model captures the appropriate boundary-layer physics at the mesoscale for moderate wind speeds quite well as indicated by the good agreement in observed and modeled properties for Frontal Air-Sea Interaction Experiment (FASINEX). Scatterometer wind data are then combined with Gulf Stream north wall positions digitized from SST fields. Each scatterometer pass was paired with the Gulf Stream path closest in time. All match-ups were then visually examined and only those for which the Gulf Stream presented a reasonably straight segment over which the wind field was free of atmospheric fronts or large curvature were selected. Ten match-ups met these criteria for the period studied. The response of the scatterometer wind field to the SST/current front was analyzed in detail for these ten cases using MM5. The importance of pressure gradients induced by changes in air temperature, moisture, and vertical mixing across oceanic front is studied in the momentum budget analysis. Our findings suggest that the perturbation pressure resulting from the thermal forcing by the front accounts for the decrease in wind speed when moving from warm to cold water and the increase observed in the converse. The dynamical forcing associated with strong surface currents is also shown to modify scatterometer-derived winds. Finally the numerical simulations suggest that the dynamical and thermal effects are very nearly additive.

Song, Qingtao

283

Tongue-shaped frontal structure and warm water intrusion in the southern Yellow Sea in winter  

NASA Astrophysics Data System (ADS)

In winter, a thermohaline front forms at the Yellow Sea (YS) entrance where the warm and saline Cheju Warm Current (CWC) water meets cold coastal water. The frontal structure, as well as the northwestward intrusion of the warm water, was investigated by analyzing conductivity-temperature-depth (CTD) data, tracks of drifting floats, moored current data, and satellite images. The CWC water advances westward as a tongue with its tip heading westward across the YS entrance, not intruding northward along the deepest part of the YS trough, whereas a secondary warm water band is developed northwestward along the western flank of the trough. Floats in the warm tongue moved northwestward across the western frontal zone where the frontal structure was weak, reflecting the northwestward intrusion along the 50-70 m isobaths through the frontal zone. Currents in the trough do not always meet the upwind flow theory that, in an elongated basin, the wind-driven flow is upwind in the deep channel, but rather show the predominance of the southward downwind flow. Model experiments show that on the western flank of the trough, both the southeastward tide-induced residual flow and the southeastward flow due to the nonlinear effect between tide and wind are generated at the same time. Thus the intermittent intrusion of the CWC across the western frontal zone may be closely associated with the predominance of the upwind flow over the southeastward nonlinear interacted flow.

Lie, Heung-Jae; Cho, Cheol-Ho; Lee, Seok

2009-01-01

284

Quantifying Mountain Front Recharge Using Isotopic Tracers  

NASA Astrophysics Data System (ADS)

To improve our conceptual and quantitative understanding of mountain-front/mountain-block recharge (MFR) associated with the Huachuca Mountains of the Upper San Pedro River Basin in Arizona, we employed a suite of geochemical measurements including isotopic tracers and noble gases. MFR is frequently the dominant source of recharge to alluvial basins in the semiarid Basin and Range province. It consists of mountain runoff that infiltrates at the mountain front (mountain-front recharge), and percolation through the mountain bedrock that reaches the basin via the movement of deep groundwater (mountain-block recharge). The rate of MFR can be estimated from a water balance, a Darcy's law analysis, or inverse modeling of groundwater processes. Despite the large volume of research on water resources in the basin and the critical importance of MFR to the water budget, the best estimates of MFR obtained using these methods may have errors as large as 100%. We find that geochemical tracers address mechanistic questions regarding recharge seasonality, location, and rates as well as addressing groundwater flowpaths and residence times. The gradient of stable isotopes of hydrogen and oxygen in groundwater with elevation mirrors that of regional precipitation, providing a constraint on the location and seasonality of recharge. Stable isotopic signatures indicate that MFR is dominated by winter precipitation but has 1/3 or more contribution from monsoon precipitation. Detectable tritium and 14C values greater than 100 pMC for springs, shallow groundwater in mountain canyons, and from wells along the mountain front indicate decade-scale residence times. Away from the mountain front 14C values rapidly decrease, reaching 12.3±0.2 pMC near the river. This suggests total basin residence times greater than 10,000 years, consistent with past measurements. Ongoing analysis of noble gas concentrations will provide an indication of recharge conditions. The solubility of noble gases in water depends on temperature and pressure; thus, noble gas concentrations provide a means to distinguish water samples recharged at different elevations.

Wahi, A. K.; Ekwurzel, B.; Hogan, J. F.; Eastoe, C. J.; Baillie, M. N.

2005-05-01

285

From the front  

SciTech Connect

The causes of recent dynamic thinning of Greenland's outlet glaciers have been debated. Realistic simulations suggest that changes at the marine fronts of these glaciers are to blame, implying that dynamic thinning will cease once the glaciers retreat to higher ground. For the last decade, many outlet glaciers in Greenland that terminate in the ocean have accelerated, thinned, and retreated. To explain these dynamic changes, two hypotheses have been discussed. Atmospheric warming has increased surface melting and may also have increased the amount of meltwater reaching the glacier bed, increasing lubrication at the base and hence the rate of glacier sliding. Alternatively, a change in the delicate balance of forces where the glacier fronts meet the ocean could trigger the changes. Faezeh Nick and colleagues5 present ice-sheet modeling experiments that mimic the observations on Helheim glacier, East Greenland, and suggest that the dynamic behaviour of outlet glaciers follows from perturbations at their marine fronts. Greenland's ice sheet loses mass partly through surface melting and partly through fast flowing outlet glaciers that connect the vast plateau of inland ice with the ocean. Earlier ice sheet models have failed to reproduce the dynamic variability exhibited by ice sheets over time. It has therefore not been possible to distinguish with confidence between basal lubrication from surface meltwater and changes at the glaciers' marine fronts as causes for the observed changes on Greenland's outlet glaciers. But this distinction bears directly on future sea-level rise, the raison d'etre of much of modern-day glaciology: If the recent dynamic mass loss Greenland's outlet glaciers is linked to changing atmospheric temperatures, it may continue for as long as temperatures continue to increase. On the other hand, if the source of the dynamic mass loss is a perturbation at the ice-ocean boundary, these glaciers will lose contact with that perturbation after a finite amount of thinning and retreat. Therefore, the first hypothesis implies continued retreat of outlet glaciers into the foreseeable future, while the second does not -- provided the bedrock topography prohibits a connection between the retreating glacier and the ocean. Nick and coauthors test the physical mechanisms implied in each hypotbesis in an innovative ice-flow model, and use that model to try to match a time series of observations from Helheim glacier, one of Greenland's three largest outlet glaciers. Along with many observations, the simulations strongly support the contention that the recent retreat of Greenland's outlet glaciers is the result of changes at their marine fronts.Further, the simulations confirm the earlier hypotheses that bedrock topography largely controlled Helheim glacier's rapid acceleration and retreat in 2004 and 2005, and its deceleration and stabilization in 2006. Finally, the current work implies that if requirements of observational data (high-resolution bed topography) and computational resources (fine computational grid resolution) can be met, improved predictive capability for ice-sheet models is attainable. With respect to the concerns raised by the IPCC, this study signals progress.

Price, Stephen [Los Alamos National Laboratory

2009-01-01

286

Hot, Cold, and Really Cold.  

ERIC Educational Resources Information Center

|Describes a physics experiment investigating temperature prediction and the relationship between the physical properties of heat units, melting, dissolving, states of matter, and energy loss. Details the experimental setup, which requires hot and cold water, a thermometer, and ice. Notes that the experiment employs a deliberate counter-intuitive…

Leyden, Michael

1997-01-01

287

Winter Cardiovascular Diseases Phenomenon  

PubMed Central

This paper review seasonal patterns across twelve cardiovascular diseases: Deep venous thrombosis, pulmonary embolism, aortic dissection and rupture, stroke, intracerebral hemorrhage, hypertension, heart failure, angina pectoris, myocardial infarction, sudden cardiac death, venricular arrythmia and atrial fibrillation, and discuss a possible cause of the occurrence of these diseases. There is a clear seasonal trend of cardiovascular diseases, with the highest incidence occurring during the colder winter months, which have been described in many countries. This phenomenon likely contributes to the numbers of deaths occurring in winter. The implications of this finding are important for testing the relative importance of the proposed mechanisms. Understanding the influence of season and other factors is essential when seeking to implement effective public health measures.

Fares, Auda

2013-01-01

288

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 ...

Butcher, Kirsten

2008-09-26

289

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

290

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

291

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

292

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

293

AMBIPOLAR DIFFUSION-MEDIATED THERMAL FRONTS IN THE NEUTRAL INTERSTELLAR MEDIUM  

SciTech Connect

In a thermally bistable medium, cold, dense gas is separated from warm, rarefied gas by thin phase transition layers, or fronts, in which heating, radiative cooling, thermal conduction, and convection of material are balanced. We calculate the steady-state structure of such fronts in the presence of magnetic fields, including the processes of ion-neutral drift and ion-neutral frictional heating. We find that ambipolar diffusion efficiently transports the magnetic field across the fronts, leading to a flat magnetic field strength profile. The thermal profiles of such fronts are not significantly different from those of unmagnetized fronts. The near uniformity of the magnetic field strength across a front is consistent with the flat field strength-gas density relation that is observed in diffuse interstellar gas.

Stone, Jennifer M.; Zweibel, Ellen G. [Department of Astronomy, University of Wisconsin-Madison, 475 North Charter Street, Madison, WI 53706 (United States)

2010-11-20

294

Monarchs wintering in trees  

NSDL National Science Digital Library

Monarch butterflies migrate south in the fall to Mexico to avoid the harsh cold of the northern regions. They fly back toward the north in the spring. Once they reach their destination in the spring, they only have a few more weeks or so to live. They take this time to mate.

Mila Zinkova (None;)

2007-11-16

295

Staying Warm Winter Experiments  

NSDL National Science Digital Library

These experiments use simple materials to prove that a lot of one's body heat escapes from one's head and that wearing a hat stops some of this heat loss. In addition, students consider how sitting directly on cold ground will cause one to lose heat faster than sitting on insulating material.

296

Winter convection continues in the warming southern Adriatic  

NASA Astrophysics Data System (ADS)

During winters in the eastern Mediterranean, cold winds blow over the waters of the southern portion of the Adriatic Sea, resulting in heat loss of the ocean. This cold surface water becomes denser than surrounding waters and sinks into the deep reaches of the Mediterranean Sea. This forms ‘deep water,’ or water once at the ocean's surface that now has sunk to depths of 1500 meters and more. The Southern Adriatic Pit (SAP) is the convection site and source for the Eastern Mediterranean Deep Water (EMDW). Since the late 1980s, the SAP has been monitored almost every year because of its importance in driving the eastern Mediterranean deep circulation convection cell.

Civitarese, Giuseppe; Ga?i?, Miroslav; Cardin, Vanessa; Ibello, Valeria

297

Zooplankton data report: Winter MIZEX, 1987  

SciTech Connect

The Marginal Ice Zone Experiment (MIZEX) was an interdisciplinary, international Arctic research program designed to study the atmospheric, oceanic, and ice interactions in the Fram Strait region of the Greenland Sea. This report focuses on zooplankton data collected during the winter MIZEX program of 1987. The primary objectives of our group during MIZEX 87 were to study the distribution of zooplankton species in relation to the ice-edge, the Polar Front, and the mesoscale eddy field, and to study zooplanktonic physiology just prior to the spring phytoplankton bloom. The data in this report are quantitative analyses of zooplankton samples collected while aboard the research vessel HAKON MOSBY during MIZEX 87. This is the third in a series of data reports on zooplankton collected in the Fram Strait region during the MIZEX project. A complete catalog of the reports generated from the MIZEX program is archived at the National Snow and Ice Data Center in Boulder, Colorado, USA. 1 ref., 3 tabs.

Smith, S.L.; Lane, P.V.Z.; Schwartling, E.M.; Beck, B.

1988-12-01

298

Hydrodynamic and sedimentary responses to two contrasting winter storms on the inner shelf of the northern Gulf of Mexico  

Microsoft Academic Search

Results are presented from the deployment of three bottom-mounted instrumentation systems in water depths of 6–9 m on the sandy inner shelf of Louisiana, USA. The 61-day deployment included nine cold front passages that were associated with large increases in wind speed. Two of the most energetic cold front passages were characterized by distinct meteorological, hydrodynamic, bottom boundary layer, and

David A. Pepper; Gregory W. Stone

2004-01-01

299

Investigations of a Winter Mountain Storm in Utah. Part II: Mesoscale Structure, Supercooled Liquid Water Development, and Precipitation Processes.  

NASA Astrophysics Data System (ADS)

A comprehensive analysis of a deep winter storm system during its passage over the Tushar Mountains of southwestern Utah is reported. The case study, drawn from the 1985 Utah/NOAA cooperative weather modification experiment, is divided into descriptions of the synoptic and kinematic properties in Part I, and storm structure and composition here in Part II. In future parts of this series, the turbulence structure and indicated cloud seeding potential will be evaluated. The analysis presented here in Part II focuses on multiple remote sensor and surface microphysical observations collected from a midbarrier (2.57 km MSL) field site. The collocated remote sensors were a dual-channel microwave radiometer, a polarization lidar, and a Ka-band Doppler radar. These data are supplemented by upwind, valley-based C-band Doppler radar observations, which provided a considerably larger-scale view of the storm.In general, storm properties above the barrier were either dominated by barrier-level orographic clouds or propagating mesoscale cloud systems. The orographic cloud component consisted of weakly (3° to 10°C) supercooled liquid water (SLW) clouds in the form of an extended barrier-wide cap cloud that contained localized SLW concentrations. The spatial SLW distribution was linked to topographical features surrounding the midbarrier site, such as abrupt terrain rises and nearby ridges. This orographic cloud contributed to precipitation primarily through the riming of particles sedimenting from aloft, and also to some extent through an ice multiplication process involving graupel growth. In contrast, mesoscale precipitation bands associated with a slowly moving cold front generated much more significant amounts of snowfall. These precipitation bands periodically disrupted the shallow orographic SLW clouds. Mesoscale vertical circulations appear to have been particularly important in SLW and precipitation production along the leading edges of the bands. Since the SLW clouds during the latter part of the storm were based at the frontal boundary, SLW and precipitation gradually diminished as the barrier became submerged under the cold front.Based on a winter storm conceptual model, we conclude that low-level orographic SLW clouds, when decoupled from the overlying ice cloud layers of the storm, are generally inefficient producers of precipitation due to the typically warm temperatures at these altitudes in our region.

Sassen, Kenneth; Huggins, Arlen W.; Long, Alexis B.; Snider, Jack B.; Meitín, Rebecca J.

1990-06-01

300

Gust Front Case Studies Handbook.  

National Technical Information Service (NTIS)

Gust fronts produce low altitude wind shear that can be hazardous to aircraft operations, especially during takeoff and landing. Radar meterologists have long been able to identify gust front signatures in Doppler radar data, but in order to use the radar...

D. L. Klingle

1985-01-01

301

Stability of Generalized Transition Fronts  

Microsoft Academic Search

We study the qualitative properties of the generalized transition fronts for the reaction- diusion equations with the spatially inhomogeneous nonlinearity of the ignition type. We show that transition fronts are unique up to translation in time and are globally exponentially stable for the solutions of the Cauchy problem. The results hold for reaction rates that have arbitrary spatial variations provided

Antoine MelletJames Nolen; Jean-Michel Roquejore; Lenya Ryzhik

2009-01-01

302

Fronts on the Continental Shelf  

Microsoft Academic Search

A well-defined class of fronts occurring in the shelf seas around the United Kingdom during the summer months marks the boundary between stratified and vertically mixed regimes. The occurrence of these fronts may be interpreted in terms of the distribution of available turbulent kinetic energy from the tidal currents and wind stress and the bouyancy flux input at the surface.

J. H. Simpson; C. M. Allen; N. C. G. Morris

1978-01-01

303

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 ...

Prested, Miss

2010-05-26

304

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 ...

Cook, Mrs.

2010-11-05

305

COLD TRAPS  

DOEpatents

A cold trap is presented for removing a condensable component from a gas mixture by cooling. It consists of a shell, the exterior surface of which is chilled by a refrigerant, and conductive fins welded inside the shell to condense the gas, and distribute the condensate evenly throughout the length of the trap, so that the trap may function until it becomes completely filled with the condensed solid. The contents may then be removed as either a gas or as a liquid by heating the trap. This device has particuinr use as a means for removing uranium hexafluoride from the gaseous diffusion separation process during equipment breakdown and repair periods.

Thompson, W.I.

1958-09-30

306

Traveling fronts of copper deposition.  

PubMed

We report the experimental observation of traveling fronts during the electroless deposition of copper on passive steel substrates. The low-carbon steel samples are passivated in nitric acid prior to the plating experiment, thus creating a thin, protective oxide layer on the steel surface. The deposition experiments are carried out from slightly acidic (pH 3.2) copper sulfate solution and copper nitrate solution with the latter showing front propagation only in the presence of chloride ions. For up to 30 s, fronts propagate with constant velocities in the range from 0.5 to 5 mm/s depending on the experimental conditions. This phase of constant-speed propagation gives way to accelerating fronts and very rapid, spatially unstructured deposition. Front-mediated plating is observed over a wide range of cupric ion concentration and constitutes a striking and unexpected example for pattern formation in electrochemical systems. PMID:12197727

Thouvenel-Romans, Stephanie; Agladze, Konstantin; Steinbock, Oliver

2002-09-01

307

Sierra Nevada Winter Storms: a Study Using Microwave Radiometry, Ice Crystal and Isotopic Analysis Technique  

NASA Astrophysics Data System (ADS)

An observational study has been made of ice-phase winter storm clouds over the Sierra Nevada mountains. In Part I, two microwave radiometers, one designed with a spinning reflector to shed precipitation particles while the other radiometer's reflector was fixed, are compared. The absence/presence of contaminated periods in the data was attributed to difference in design. These apparent contaminated periods led to lower correlation coefficients between the radiometers. Comparison of radiometer and rawinsonde resulted in a correlation coefficient of 0.97 for the spinning reflector as opposed to 0.8 for the fixed reflector radiometer. In Part II, stable water isotopes were used to study mesoscale and microscale storm modifications by the Sierra Nevada. Initially, a low level warm front lay across the region and its elevation lowered with time from 2.5 km to 1.7 km. This decrease of frontal surface height was accompanied by a steady increase in the delta ^{18}O values. In the pre-cold frontal period, the delta^{18 }O values at the upwind site signified warmer origin ice crystals than the downwind site. This is explained by orographic effects and the production of supercooled liquid water at low elevations on the upslope side. The delta^{18}O value peaked around -13perthous which translates to an "equivalent temperature" of -10.7^circC for ice phase water capture at the upwind site. At the downwind site, this was some 5 to 6 centigrade degrees colder. During surface cold front passage, the differences in delta^{18}O at the two sites are small probably because, during frontal passage, the orography plays a less significant role in the precipitation production process. In Part III, observations of precipitation rates, ice crystals, wind and supercooled liquid water (SLW) upwind and downwind of the Sierra Nevada are presented. Observations show that the stage of development of the storms was important in the liquid and vapor development. High SLW, and increased riming were located before the frontal passage. Duration of SLW as observed by the radiometers, was always shorter over the downwind station. Heavy riming was associated with precipitation decrease while high precipitation rates were correlated with high number fraction of aggregate crystals. Aggregation was found to be an important process for precipitation development over the downwind station.

Demoz, Belay Berhane

308

Dispersant Effectiveness Testing in Cold Water on Four Alaskan Crude Oils.  

National Technical Information Service (NTIS)

In the winter of 2003, shortly after dispersant testing began at Ohmsett, five Alaskan crude oils including Alaskan North Slope (ANS), Endicott, Pt. McIntyre, Northstar and Middleground Shoals were tested in cold-water conditions. Corexit 9527 dispersant ...

2006-01-01

309

Cold Urticaria  

PubMed Central

Sera were obtained from the venous effluents of cold-challenged arms of patients with idiopathic cold urticaria without plasma or serum cryoproteins; these sera exhibited increased neutrophil chemotactic activity without alterations of the complement system. A two- to fourfold augmentation of the base-line neutrophil chemotactic activity of serum from the immersed extremity began within 1 min, peaked at 2 min, and returned to base-line levels within 15 min, whereas there was no change in the serum chemotactic activity in the control arm. The augmented chemotactic activity in the serum specimens from the challenged arm of each patient appeared in a high molecular-weight region, as assessed by the difference in activity recovered after Sephadex G-200 gel filtration of the paired lesional and control specimens. Sequential purification of this high molecular-weight activity by anion- and cation-exchange chromatography revealed a single peak of activity at both steps. The partially purified material continued to exhibit a high molecular weight, being excluded on Sepharose 4B, and had a neutral isoelectric point. The partially purified material showed a preferential chemotactic activity for neutrophilic polymorphonuclear leukocytes, required a gradient for expression of this function, and exhibited a capacity to deactivate this cell type. This active principle, termed high molecular-weight neutrophil chemotactic factor, exhibited a time-course of release that could be superimposed upon that of histamine and the low molecular-weight eosinophil chemotactic factor and may represent another mast cell-derived mediator.

Wasserman, Stephen I.; Soter, Nicholas A.; Center, David M.; Austen, K. Frank

1977-01-01

310

Holocene winter climate variability in mid-latitude western North America.  

PubMed

Water resources in western North America depend on winter precipitation, yet our knowledge of its sensitivity to climate change remains limited. Similarly, understanding the potential for future loss of winter snow pack requires a longer perspective on natural climate variability. Here we use stable isotopes from a speleothem in southwestern Oregon to reconstruct winter climate change for much of the past 13,000 years. We find that on millennial time scales there were abrupt transitions between warm-dry and cold-wet regimes. Temperature and precipitation changes on multi-decadal to century timescales are consistent with ocean-atmosphere interactions that arise from mechanisms similar to the Pacific Decadal Oscillation. Extreme cold-wet and warm-dry events that punctuated the Holocene appear to be sensitive to solar forcing, possibly through the influence of the equatorial Pacific on the winter storm tracks reaching the US Pacific Northwest region. PMID:23187619

Ersek, Vasile; Clark, Peter U; Mix, Alan C; Cheng, Hai; Edwards, R Lawrence

2012-01-01

311

Formation of surface to bottom fronts over steep topography  

SciTech Connect

Imposed horizontal density differences in a laterally unbounded rotating fluid across a bottom of variable depth lead to the formation of surface to bottom fronts with enhanced asymmetry. In a two-layer fluid, the down-slope spillage of heavy fluid leads to greater lower layer penetration than the extent of upper layer advance in the opposite direction. These finite amplitude movements generate barotropic flows that have the same direction as the velocity in the layer that thins as a result of the movement. Lower-layer movements up the depth gradient enhance the generation of lower-layer flow due to vortex foreshortening and favor a barotropic flow in the same direction. In contrast, lower-layer movements down the depth gradient enhance the upper-layer flow for the same reason and favor a barotropic flow in the direction of that flow. Extended down-slope movement of heavy fluids also leads to the formation of isolated heavy fluid lens over the bottom, within which the flow is reminiscent of observed bottom currents such as that associated with the cold, dense Norwegian Sea water south of the Denmark Strait (Smith, 1976). In addition to bodily displacing the front in the Ekman sense, uniform surface stress directed with deep (shallow) fluid to the right flattens (sharpens) the front. The displacement of the front as a whole also gives rise to additional vortex stretching that leads to further deviation from symmetry in the cross-front distribution of the barotropic transport.

Hsueh, Y.; Cushman-Roisin, B.

1983-01-20

312

Over the counter medicines for colds  

Microsoft Academic Search

Over the counter (OTC) medicines may be defined as medicines that are freely available to the public without a prescription\\u000a from a doctor. Self-medication for common cold is now encouraged by most government health authorities in order not to overload\\u000a health resources in winter. This chapter examines the efficacy of the different groups of medicines for the relief of common

Ronald Eccles

313

Problem of the Old and the Cold*  

PubMed Central

A pilot winter study of body temperatures using new measuring techniques was tested on 72 volunteers aged 65 or more living in Portsmouth. The body temperatures were related to their environmental temperature and living conditions. No case of serious hypothermia was found, but the study confirms that elderly people have lower body temperatures and suggests that the coldest individuals tended to be the least aware of discomfort from the cold; this may well place them “at risk” for developing hypothermia.

Fox, R. H.; MacGibbon, R.; Davies, Louise; Woodward, Patricia M.

1973-01-01

314

Winter North Atlantic Oscillation, temperature and ischaemic heart disease mortality in three English counties  

Microsoft Academic Search

As cold weather is an ischaemic heart disease (IHD) risk factor, year-to-year variations of the level of IHD mortality may be partly determined by inter-annual variations in winter climate. This paper investigates whether there is any association between the level of IHD mortality for three English counties and the winter North Atlantic Oscillation (NAO), which exerts a fundamental control on

Glenn R McGregor

2005-01-01

315

Atmospheric turbulence structure in the vicinity of an oceanic front  

NASA Astrophysics Data System (ADS)

Fast response data taken aboard the National Oceanic and Atmospheric Administration WP-3D aircraft are used to determine the structure of atmospheric boundary layer turbulence on either side of a well-developed sea surface temperature front southwest of Bermuda. The data were taken on February 17, 1986, as part of the Frontal Air-Sea Interaction Experiment (FASINEX). A broad region of low-humidity air extending from 15 km to 35 km south of the front is probably due to the presence of a frontally induced secondary circulation. Evidence for a secondary flow is found in both the time series of atmospheric variables and the statistics obtained from conditionally sampled updrafts and downdrafts in the transect across the SST front. Larger sea-air temperature and humidity difference on the warm (south) side of the front give rise to surface layer sensible and latent heat and buoyancy fluxes that are larger than those on the cold side. Turbulence structure appears to be influenced as much by the presence of strong wind shear at the top of the boundary layer as by differing conditions at the surface on either side of the front. A larger rate of entrainment on the warm side of the front is indicated by the greater influence of low-momentum air from the overlying shear layer on updrafts in the upper part of the mixed layer, as well as the more frequent overtunning of cool/moist updrafts and warm/dry downdrafts. It is conjectured that the larger entrainment rate is due to the interaction between the inversion layer and more energetic updrafts produced by greater surface forcing on the warm side of the front.

Jodha, Siri; Khalsa, Singh; Greenhut, Gary K.

1989-04-01

316

O the Air-Mass Temperature Distribution in the Middle and High Troposphere in Winter  

Microsoft Academic Search

To place the upper-air analysis of baroclinic fields such as those associated with the polar front and the jet stream on a firmer basis, winter temperature data for selected stations in North America and the British Isles are analyzed. From the form of temperature frequency distributions for these stations at various levels in the middle and higher troposphere, it is

D. P. McIntyre

1950-01-01

317

Metabolic and Ultrastructural Changes in Winter Wheat during Ice Encasement Under Field Conditions 1  

PubMed Central

The effect of ice encasement on the physiological, metabolic, and ultrastructural properties of winter wheat (Triticum aestivum L.) grown under field conditions was examined by artificially encasing winter wheat in ice during early winter. Cold hardiness and survival of ice-encased seedlings declined less rapidly in Kharkov, a cold-hardy cultivar than in Fredrick, a less hardy cultivar. Ethanol did not accumulate in non-iced seedlings, but increased rapidly upon application of an ice sheet. Lactic acid accumulated in both cultivars during late autumn, prior to ice encasement, and elevated levels of lactic acid were maintained throughout the winter in seedlings from both iced and non-iced plots. The rate of O2 consumption of shoot tissue of seedlings from non-iced plots remained relatively constant throughout the winter, but declined rapidly in seedlings from ice encased plots. Major ultrastructural changes did not occur in shoot apex cells of non-iced winter wheat seedlings during cold hardening under field conditions. However, the imposition of an ice cover in early January resulted in a proliferation of the endoplasmic reticulum membrane system of the cells, frequently resulting in the formation of concentric whorls of membranes, often enclosing cytoplasmic organelles. Electrondense areas within the cytoplasm which appeared to be associated with the expanded endoplasmic reticulum were also frequently observed. ImagesFIG. 3FIG. 4FIG. 5FIG. 6FIG. 7FIG. 8

Pomeroy, M. Keith; Andrews, Christopher J.

1978-01-01

318

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.

319

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

320

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

321

The anomalous winter of 1783-1784: Was the Laki eruption or an analog of the 2009-2010 winter to blame?  

NASA Astrophysics Data System (ADS)

The multi-stage eruption of the Icelandic volcano Laki beginning in June, 1783 is speculated to have caused unusual dry fog and heat in western Europe and cold in North America during the 1783 summer, and record cold and snow the subsequent winter across the circum-North Atlantic. Despite the many indisputable impacts of the Laki eruption, however, its effect on climate, particularly during the 1783-1784 winter, may be the most poorly constrained. Here we test an alternative explanation for the unusual conditions during this time: that they were caused primarily by a combined negative phase of the North Atlantic Oscillation (NAO) and an El Niño-Southern Oscillation (ENSO) warm event. A similar combination of NAO-ENSO phases was identified as the cause of record cold and snowy conditions during the 2009-2010 winter in Europe and eastern North America. 600-year tree-ring reconstructions of NAO and ENSO indices reveal values in the 1783-1784 winter second only to their combined severity in 2009-2010. Data sources and model simulations support our hypothesis that a combined, negative NAO-ENSO warm phase was the dominant cause of the anomalous winter of 1783-1784, and that these events likely resulted from natural variability unconnected to Laki.

D'Arrigo, Rosanne; Seager, Richard; Smerdon, Jason E.; LeGrande, Allegra N.; Cook, Edward R.

2011-03-01

322

Winter North Atlantic Oscillation, temperature and ischaemic heart disease mortality in three English counties.  

PubMed

As cold weather is an ischaemic heart disease (IHD) risk factor, year-to-year variations of the level of IHD mortality may be partly determined by inter-annual variations in winter climate. This paper investigates whether there is any association between the level of IHD mortality for three English counties and the winter North Atlantic Oscillation (NAO), which exerts a fundamental control on the nature of the winter climate over Western Europe. Correlation and regression analysis was used to explore the nature of the association between IHD mortality and a climate index (CI) that represents the interaction between the NAO and temperature across England for the winters 1974-1975 to 1989-1999. Statistically significant inverse associations between the CI and the level of IHD mortality were found. Generally, high levels of winter IHD mortality are associated with a negative CI, which represents winters with a strong negative phase of the NAO and anomalously low temperatures across England. Moreover, the nature of the CI in the early stages of winter appears to exert a fundamental control on the general level of winter IHD mortality. Because winter climate is able to explain a good proportion of the inter-annual variability of winter mortality, long-lead forecasting of winter IHD mortality appears to be a possibility. The integration of climate-based health forecasts into decision support tools for advanced general winter emergency service and capacity planning could form the basis of an effective adaptive strategy for coping with the health effects of harsh winters. PMID:15290431

McGregor, Glenn R

2004-08-03

323

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

324

MHD STABILITY OF INTERSTELLAR MEDIUM PHASE TRANSITION LAYERS. I. MAGNETIC FIELD ORTHOGONAL TO FRONT  

SciTech Connect

We consider the scenario of a magnetic field orthogonal to a front separating two media of different temperatures and densities, such as cold and warm neutral interstellar gas, in a two-dimensional plane-parallel geometry. A linear stability analysis is performed to assess the behavior of both evaporation and condensation fronts when subject to incompressible, corrugational perturbations with wavelengths larger than the thickness of the front. We discuss the behavior of fronts in both super-Alfvenic and sub-Alfvenic flows. Since the propagation speed of fronts is slow in the interstellar medium (ISM), it is the sub-Alfvenic regime that is relevant, and magnetic fields are a significant influence on front dynamics. In this case, we find that evaporation fronts, which are unstable in the hydrodynamic regime, are stabilized. Condensation fronts are unstable, but for parameters typical of the neutral ISM the growth rates are so slow that steady-state fronts are effectively stable. However, the instability may become important if condensation proceeds at a sufficiently fast rate. This paper is the first in a series exploring the linear and nonlinear effects of magnetic field strength and orientation on the corrugational instability, with the ultimate goal of addressing outstanding questions about small-scale ISM structure.

Stone, Jennifer M.; Zweibel, Ellen G. [Department of Astronomy, University of Wisconsin-Madison, 475 N. Charter Street, Madison, WI 53706 (United States)

2009-05-01

325

Glycogen, not dehydration or lipids, limits winter survival of side-blotched lizards (Uta stansburiana).  

PubMed

Climate change is causing winters to become milder (less cold and shorter). Recent studies of overwintering ectotherms have suggested that warmer winters increase metabolism and decrease winter survival and subsequent fecundity. Energetic constraints (insufficient energy stores) have been hypothesized as the cause of winter mortality but have not been tested explicitly. Thus, alternative sources of mortality, such as winter dehydration, cannot be ruled out. By employing an experimental design that compared the energetics and water content of lizards that died naturally during laboratory winter with those that survived up to the same point but were then sacrificed, we attempt to distinguish among multiple possible causes of mortality. We test the hypothesis that mortality is caused by insufficient energy stores in the liver, abdominal fat bodies, tail or carcass or through excessive water loss. We found that lizards that died naturally had marginally greater mass loss, lower water content, and less liver glycogen remaining than living animals sampled at the same time. Periodically moistening air during winter reduced water loss, but this did not affect survival, calling into question dehydration as a cause of death. Rather, our results implicate energy limitations in the form of liver glycogen, but not lipids, as the primary cause of mortality in overwintering lizards. When viewed through a lens of changing climates, our results suggest that if milder winters increase the metabolic rate of overwintering ectotherms, individuals may experience greater energetic demands. Increased energy use during winter may subsequently limit individual survival and possibly even impact population persistence. PMID:22875774

Zani, Peter A; Irwin, Jason T; Rollyson, Mary E; Counihan, Jessica L; Healas, Sara D; Lloyd, Emily K; Kojanis, Lee C; Fried, Bernard; Sherma, Joseph

2012-09-01

326

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

PubMed

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. PMID:23423627

Grüebler, Martin U; Widmer, Silv; Korner-Nievergelt, Fränzi; Naef-Daenzer, Beat

2013-02-20

327

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.

Grüebler, Martin U.; Widmer, Silv; Korner-Nievergelt, Fränzi; Naef-Daenzer, Beat

2013-02-01

328

Foal behaviour in a loose housing\\/paddock environment during winter  

Microsoft Academic Search

The aim of this study was to establish some basic facts about weanling horse (Equus caballus) behaviour in a loose housing\\/paddock environment during winter. The behaviour of 10 foals (seven American Standardbred and three Finnish cold-blooded foals) was observed in a cold loose housing\\/paddock environment from December 2002 to March 2003. The time budget, circadian rhythm and effect of weather

E. Autio; M.-L. Heiskanen

2005-01-01

329

Air-sea fluxes and surface layer turbulence around a sea surface temperature front  

NASA Astrophysics Data System (ADS)

The response of the lower marine atmospheric boundary layer to sharp changes in sea surface temperature was studied in the Frontal Air-Sea Interaction Experiment (FASINEX) with aircraft and ships measuring mean and turbulence quantities, sea surface temperature, and wave state. Changing synoptic weather on 3 successive days provided cases of wind direction both approximately parallel and perpendicular to a surface temperature front. For the wind perpendicular to the front, both wind over cold-to-warm and warm-to-cold surface temperatures occurred. For the cold-to-warm case, the unstable boundary layer was observed to thicken, with increased convective activity on the warm side. For the warm-to-cold case, the surface layer buoyant stability changed from unstable to neutral or slightly stable, and the sea state and turbulence structure in the lower 100 m were immediately altered, with a large decrease in stress and slowing of the wind. Measurements for this case with two aircraft in formation at 30 and 100 m show a slightly increased stress divergence on the cold side. The turbulent velocity variances changed anisotropically across the front: the streamwise variance was practically unchanged, whereas the vertical and cross-stream variances decreased. Model results, consistent with the observations, suggest that an internal boundary layer forms at the sea surface temperature front. The ocean wave, swell, and microwave radar backscatter fields were measured from several aircraft which flew simultaneously with the low-level turbulence aircraft. Significant reductions in backscatter and wave height were observed on the cold side of the front.

Friehe, C. A.; Shaw, W. J.; Rogers, D. P.; Davidson, K. L.; Large, W. G.; Stage, S. A.; Crescenti, G. H.; Khalsa, S. J. S.; Greenhut, G. K.; Li, F.

1991-05-01

330

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.

Chawade, Aakash; Linden, Pernilla; Brautigam, Marcus; Jonsson, Rickard; Jonsson, Anders; Moritz, Thomas; Olsson, Olof

2012-01-01

331

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 40-90°N 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 60°N and 40 K at 90°N around mid-January. The heat flux also showed high values in line with the increase in temperatures, of about 425 m K/s at 60°N at the same pressure level. However, the westerlies were strong (e.g. 35-45 m/s at 60°N) 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.; Lefèvre, F.; Santee, M. L.; Froidevaux, L.

2011-12-01

332

Eddy overturning of the Antarctic Slope Front controls glacial melting in the Eastern Weddell Sea  

NASA Astrophysics Data System (ADS)

The Eastern Weddell Sea is characterized by narrow continental shelves and Warm Deep Water (WDW) is located in close proximity to the ice shelves in this region. The exchange of WDW across the Antarctic Slope Front (ASF) determines the rate of basal ice shelf melting. Here, we present a unique data set consisting of 2351 vertical profiles of temperature and salinity collected by southern elephant seals (Mirounga leonina) and a profile beneath the Fimbul Ice Shelf (FIS), obtained via drilling through 395 m of ice. This data set reveals variations in salinity and temperature through winter, and using a conceptual model of the coastal salt budget we quantify the main exchange processes. Our data show that modified WDW, with temperatures below -1.5°C, is advected onto the shelf and into the ice shelf cavities by an eddy overturning of the ASF. The onshore Ekman flux of surface waters during summer is the main source of freshwater that leads to the formation of low salinity shelf waters in the region. The modified WDW that reaches beneath the ice shelves is too cold for basal ice shelf melting to create such low salinity water. A high-resolution model of an idealized ASF-continental shelf-ice shelf system supports the conclusions from the data analysis. The inflow of WDW onto the continental shelf and into the ice shelf cavity occurs within a bottom boundary layer where the eddy advection in the model is particularly strong, in close agreement with the observed vertical profile of temperature beneath the FIS.

NøSt, O. A.; Biuw, M.; Tverberg, V.; Lydersen, C.; Hattermann, T.; Zhou, Q.; Smedsrud, L. H.; Kovacs, K. M.

2011-11-01

333

A numerical study of gyres, thermal fronts and seasonal circulation in austral semi-enclosed gulfs  

NASA Astrophysics Data System (ADS)

This article analyses the results from a high resolution numerical model of the North Patagonian Gulfs (San Matías Gulf, SMG; Nuevo Gulf, NG; and San José Gulf, SJG), a region of the South Western Atlantic Shelf that has long been recognized for its high productivity and biodiversity. The aim of the study is to explore the physical processes that control the mean circulation and its seasonal variability with focus on the generation of recirculation features (gyres) and frontal structures. The numerical results showed that both tidal and wind forcing significantly contribute to delineate the frontal structures and the seasonal circulation in the North Patagonian Gulfs. The overall summer circulation pattern in SMG is dominated by two strong cyclonic subgyres in the northern and southern sectors while NG showed only one gulf-wide cyclonic gyre. The northern subgyre in SMG and the NG gyre are caused by the interaction of the tides and the evolving stratification driven by surface heat and freshwater fluxes. A series of sensitivity experiments showed that the formation and intensity of a summer zonal front in SMG is controlled by the wind-driven advection of cold waters from a homogenized pool generated by intense tidal mixing in the inner continental shelf (east of Valdés Península). From April to August, when winter erodes the stratification, the northern SMG subgyre and the NG gyre spin down and gradually shrink in size. At this time of the year, the western SMG and NG are occupied by an anticyclonic gyre driven by intense westerlies. In contrast, the mean circulation in SJG is dominated year-round by a pair of strong counter-rotating eddies produced by tidal rectification.

Tonini, Mariano H.; Palma, Elbio D.; Piola, Alberto R.

2013-08-01

334

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

335

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

336

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

337

Identifying the Western Pacific Salinity Front Using Aquarius Measurement  

NASA Astrophysics Data System (ADS)

Aquarius satellite mission is designed to measure high-resolution sea surface salinity both spatially and temporally. In this study, we smoothed the Aquarius salinity data on a 1/3*1/3 degree weekly gridded map over the western Pacific warm pool region. A sharp northeast-southwest oriented salinity front is seen in detail, but is not observed in the 1*1 degree monthly Argo map due to the low resolution. The salinity front (defined by the largest salinity gradient) is located close to 34.6 PSU isohaline (criteria generally used to define the location of salinity front), but is better defined with physical meanings. During the first four months of Aquarius measurement from Sep/2011-Dec/2011, the salinity front has penetrated much farther west than usual, associated with the westward shift of eastern edge of warm pool. Also, from the surface currents calculated from Ocean Surface Current Analyses - Real time (OSCAR), we notice that the strong westward currents enhance the zonal advection of sea surface temperature/salinity and bring the cold/salty water from central to western Pacific. This is related to the evolution of the central Pacific type of La Nina (i.e. cooling event centered in the central Pacific) in the end of 2011. The results also show that the salinity front shows up at the boundary between the south equatorial currents and north equatorial counter currents, suggesting the strong relationship between the formation of salinity front and the movement of salty and fresh water. Although further calibration/validation work is still ongoing, the preliminary results give us the confidence that the Aquarius measurement is going to help us better understand the fresh water flux and zonal advections in the western Pacific warm pool.

Kao, H.; Lagerloef, G.

2012-04-01

338

Cold pretreatment enhances microspore embryogenesis in oilseed rape ( Brassica napus L.)  

Microsoft Academic Search

Stress is an essential component during embryogenesis induction in microspore culture. Cold pretreatment has been used in cereal microspore culture but very seldom attempted in Brassica microspore culture. The effect of cold pretreatment of flower buds subjected to a liquid medium on microspore embryogenesis was investigated in spring and winter Brassica napus, as well as in B. rapa and B.

H. H. Gu; P. Hagberg; W. J. Zhou

2004-01-01

339

COLD-INDUCED ADAPTATIONS FOLLOWING A 225 km SCIENTIFIC EXPEDlTION IN ARCTIC CONDITIONS  

Microsoft Academic Search

Two male subjects participated in a mid-winter 14 day (225 km) north-south unsupported ski trek on Lake Winnipeg (Canada). The scientific expedition had 3 main research components. First, local (finger and hand) and whole body cold response tests were conducted before and after the expedition. These tests were designed to document adaptation to intense short term cold exposure in terms

GG Giesbrecht; MB Ducharme

340

Factors regulating Shasta Lake (California) cold water accumulation, a resource for endangered salmon conservation  

Microsoft Academic Search

Shasta Lake, in northern California, has recently experienced reduced cold water storage, making it difficult to meet downstream temperature objectives for endangered winter-run chinook salmon spawning habitat. This study used a novel form of time series analysis to examine the causes, timing, and predictability of cold water storage in Shasta Lake. This analysis detected two independent modes of variability in

D. K. Nickel; M. T. Brett; A. D. Jassby

2004-01-01

341

Summer Hot Snaps and Winter Conditions: Modelling White Syndrome Outbreaks on Great Barrier Reef Corals  

PubMed Central

Coral reefs are under increasing pressure in a changing climate, one such threat being more frequent and destructive outbreaks of coral diseases. Thermal stress from rising temperatures has been implicated as a causal factor in disease outbreaks observed on the Great Barrier Reef, Australia, and elsewhere in the world. Here, we examine seasonal effects of satellite-derived temperature on the abundance of coral diseases known as white syndromes on the Great Barrier Reef, considering both warm stress during summer and deviations from mean temperatures during the preceding winter. We found a high correlation (r2?=?0.953) between summer warm thermal anomalies (Hot Snap) and disease abundance during outbreak events. Inclusion of thermal conditions during the preceding winter revealed that a significant reduction in disease outbreaks occurred following especially cold winters (Cold Snap), potentially related to a reduction in pathogen loading. Furthermore, mild winters (i.e., neither excessively cool nor warm) frequently preceded disease outbreaks. In contrast, disease outbreaks did not typically occur following warm winters, potentially because of increased disease resistance of the coral host. Understanding the balance between the effects of warm and cold winters on disease outbreak will be important in a warming climate. Combining the influence of winter and summer thermal effects resulted in an algorithm that yields both a Seasonal Outlook of disease risk at the conclusion of winter and near real-time monitoring of Outbreak Risk during summer. This satellite-derived system can provide coral reef managers with an assessment of risk three-to-six months in advance of the summer season that can then be refined using near-real-time summer observations. This system can enhance the capacity of managers to prepare for and respond to possible disease outbreaks and focus research efforts to increase understanding of environmental impacts on coral disease in this era of rapidly changing climate.

Heron, Scott F.; Willis, Bette L.; Skirving, William J.; Eakin, C. Mark; Page, Cathie A.; Miller, Ian R.

2010-01-01

342

Winter performance of an urban stormwater pond in southern Sweden  

NASA Astrophysics Data System (ADS)

Evidence from cold regions in North America has shown that the performance of stormwater ponds differs between winter and summer. The pond hydraulics change seasonally, and winters have lowered removal efficiency due to a combination of an ice cover, cold water and de-icing salts. This study examines the function of the Bäckaslov stormwater pond under the more mild conditions of southern Sweden, where there are several snow and melt cycles per year.Event sampling in the summer of 1997 showed good removal efficiencies for nutrients, total suspended solids (TSS) and a selection of metals (Cd, Cu, Pb, Zn), but winter grab-tests taken in 1995-96 and 1997-98 suggest that the pond acts as a pollutant source under cold conditions. To better assess winter and spring pond performance, water at the inflow and outflow was sampled from January to April 2003. The low intensity of runoff delivery and slow inflow velocities meant that time- rather than flow-weighted sampling was used. Five consecutive events were sampled and analysed for TSS, chloride and the metals As, Cd, Cr, Cu, Hg, Ni, Pb and Zn. YSI probes were in place at both the inlet (pH, temperature) and outlet (pH, temperature, conductivity, dissolved oxygen) to determine the timing of pollution flows. In addition, profiles of the same quality indicators allowed snapshots of pond processes.De-icing salt has a major effect on pond hydraulics. Strong stratification occurred after each snowmelt-generated flow event and up to 80% of chloride could be retained by the pond. However, continuous conductivity measurements show that chloride is flushed between events. Ice changes retention times and causes oxygen depletion, but bed scour was not observed. Pond performance decreased during the winter and spring, albeit not as badly as the grab tests suggest. A seasonal comparison of the removal efficiencies showed that removal of Cd (75%) and Cu (49%) was about the same for summer and winter-spring, but removal of Pb, Zn and TSS dropped from 79%, 81% and 80% to 42%, 48% and 49% respectively. The removal efficiencies for the other metals sampled in 2003 were: As, 50%; Cr, 39%; Hg, 56%; Ni, 41%.

Semadeni-Davies, Annette

2006-01-01

343

Nonequilibrium Photodissociation Regions: Ionization-Dissociation Fronts  

Microsoft Academic Search

We discuss the theory of coupled ionization-dissociation fronts produced when molecular clouds are exposed to lambda < 1110 Å radiation from hot stars. A steady, composite structure is developed, which generally includes an ionized outflow away from the cloud, an ionization front, a layer of photodissociated gas, a photodissociation front, and a shock wave preceding the photodissociation front. We show

Frank Bertoldi; B. T. Draine

1996-01-01

344

Facts about the Common Cold  

MedlinePLUS

... Disease > Influenza > In-Depth-Resources Facts About the Common Cold What is a Cold? Colds are minor infections ... are no antiviral medications available for treating the common cold. Antibiotics are not useful for treating a cold, ...

345

Structure and Dynamics of Substorm Injection Fronts  

NASA Astrophysics Data System (ADS)

The Polar spacecraft spent a season in Fall 2001 sweeping through the magnetotail with it's 9 Re apogee very near the neutral sheet. During this season, it encountered many substorm injection events between geosynchronous orbit and 9 Re; most of them seen as encounters with the plasma sheet boundary layers. Of these, a small number were observed in the inner central plasma sheet in the evening sector. The lowest energy ion plasma (0.3 eV - 400 eV) in these events exhibited a wave-like character, with alternating cycles of radially inward and outward flow having a period of several minutes and a flow amplitude of approximately 50 km/sec, resulting in displacement amplitudes of order 1.5 Re. After a few cycles, these periodic flow cycles culminated in an inward "gust" associated with a classical hot plasma (keV) injection, similar to those observed at synchronous orbit. The outward flow cycles consisted of cold plasma (~1 eV temperature) similar to that in the outer plasmasphere, while the inward flow cycles consisted of counter-streaming plasma flows along the magnetic field, similar to polar or lobal wind plasmas. We interpret the wave-like behavior as associated with the azimuthal edges of a plasma injection bubble consisting of low content, dipolarizing flux tubes, and having an injection front as its central feature. The upcoming MMS mission will present opportunities for higher resolution studies of such events, which may offer significant insights into injection front structure and dynamics.

Moore, T. E.; Chandler, M. O.; Kepko, E.; Buzulukova, N. Y.; Sitnov, M. I.

2011-12-01

346

Applying Freezing Test to Quantify Cold Acclimation in Medicago truncatula  

Microsoft Academic Search

Understanding cold acclimation (CA) is important for concurrently improving autumn yield and winter survival in alfalfa (Medicago sativa L.). Medicago truncatula Gaertn., an annual relative of alfalfa, could be used to determine genetic bases of CA, if the ability and conditions required for its CA are determined. The major objective of this study was to develop a laboratory screening procedure

Allen D. Knapp; E. Charles Brummer

2008-01-01

347

Close the Door--You're Letting the Cold In!  

NSDL National Science Digital Library

Actually no, you aren't letting the cold in when you leave the door open in winter. That's a common misconception that will be gently put to rest in this chapter. There will, however, be a discussion of the tranfer of energy that makes things hotter and colder.

Robertson, William C.

2002-01-01

348

Behaviour of Thermal Density Currents in Cold Receiving Water Bodies  

Microsoft Academic Search

In cold climates, temperatures higher than the ambient have been observed near the bottom of water lakes in the vicinity of thermal discharges. Concern has been expressed about the adverse effects of such abnormally warm water on the winter ecology of lake bottoms. It is expected that the existence of a density extremum in water at 4° C and the

Yehla M. R. Marmoush

1985-01-01

349

COLD TEMPERATURE MOTOR VEHICLE EMISSIONS TESTING IN ALASKA  

EPA Science Inventory

A motor vehicle emissions testing study was conducted in Anchorage and Fairbanks during the winter of 1998-99 to collect actual measurements of initial idle emission rates. The study was performed for a sample of 111 automobiles and light-duty trucks under cold wintertime ambient...

350

Cold weather testing of photo-optics support systems  

Microsoft Academic Search

The described tests had been conducted to determine the capability of cine cameras and a tracking mount to operate successfully at the extreme cold temperatures to be encountered in support of the Operational Base Launch program. The evaluation of the entire tracking system is discussed. Attention is given to aspects of pretest preparation and winterization, a test lens modification, tracking

A. M. Fitzpatrick

1977-01-01

351

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

352

Linear stability analysis of convective chemical fronts  

NASA Astrophysics Data System (ADS)

A chemical front propagating upward in a fluid separates heavy unreacted fluid from light reacted fluid. The density difference caused by the front propagation leads to convection. Convection enhances the front speed and curves the front as it propagates upward in a tube. The convective front propagates with constant speed and is steady in a frame of reference comoving with the front. This paper presents a linear stability analysis of the convective front. The fronts are modeled using a front evolution equation coupled to Darcy's law for flow in porous media and the Navier-Stokes for viscous flow. The solutions can be either axisymmetric or nonaxisymmetric as observed in experiments in tubes. For flow in porous media, there is a region of bistability between both types, whereas in viscous flow the axisymmetric front is always unstable.

Vasquez, Desiderio A.

1997-12-01

353

The effect of simulated cold weather transport on core body temperature and behavior of broilers.  

PubMed

During the winter in Western Canada, broilers are routinely transported in ambient temperatures ranging from 0°C to -40°C, yet there is little research in this area. This study examined the physiology and behavior of broilers undergoing simulated transport at typical Western Canadian winter temperatures. Groups of 15 broilers aged 32 to 33 d were exposed to an air stream regulated to -5, -10, or -15°C. Birds were placed into a typical transport drawer. Following baseline observations, the drawer was placed into a test chamber where cold air was drawn past the birds for 3 h. Three replications were conducted at each temperature. The birds adjusted their position within the drawer based upon the temperature distribution within the drawer. In comparison to the baseline period, exposing the birds to a cold air stream caused them to avoid the front plane (P = 0.003) which was the coldest area within the drawer. The birds did not adjust their usage of the middle (P = 0.308) and rear (P = 0.640) planes, because these were the warmer areas within the drawer. The total amount of space the birds occupied within the drawer did not decrease when exposed to the test chamber (P = 0.669). The core body temperature (CBT) did not vary and was within the known normal range during the normal (P = 0.528), pre-chamber (P = 0.060), and post-chamber (P = 0.285) periods. The CBT of the birds significantly decreased during the in-chamber period (P < 0.001) and then increased during the lairage period (P < 0.001). The shrink loss (P = 0.981) and amount of time to resume feed consumption (P = 0.357) were not affected by exposing the birds to temperatures of -5°C and colder. Exposing birds to temperatures of -5°C and colder had a negative effect on the CBT of the birds. However, the birds demonstrated behaviors which mitigated the negative effect that cold exposure could have on their CBT. PMID:22010224

Strawford, M L; Watts, J M; Crowe, T G; Classen, H L; Shand, P J

2011-11-01

354

Winter Cooling of Arctic Fields.  

National Technical Information Service (NTIS)

The crystallization heat given off by the ice to the atmosphere and its effect on meteorological conditions in the Arctic is analyzed on the basis of observational data and theoretical computations. In connection with this, the interrelation of winter coo...

A. A. Drogaitsev

1971-01-01

355

Survival in the Winter Storm.  

National Technical Information Service (NTIS)

Deals with the dangers inherent in winter weather. Gives advice to the average citizen on how to prepare for severe weather conditions, explains the meaning of specific forecasts, and pints up the necessity for emergency planning by local governments.

1994-01-01

356

Survival in the Winter Storm.  

National Technical Information Service (NTIS)

Deals with the dangers inherent in winter weather. Gives advice to the average citizen on how to prepare for severe weather conditions, explains the meanings of specific forecasts, and points up the necessity for emergency planning by local governments.

1994-01-01

357

The Challenge of Winter Backpacking.  

ERIC Educational Resources Information Center

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

Cavanaugh, Michael; Mapes, Alan

1981-01-01

358

Habitat Suitability Index Models: American Black Duck (Wintering)  

USGS Publications Warehouse

INTRODUCTION The American black duck, commonly known as the black duck, is migratory and has a wide geographic range. American black ducks breed from Cape Hatteras, North Carolina, west to the Mississippi River and north through the eastern Canadian boreal forest (Bellrose 1976). The winter range extends from the Rio Grande River on the Texas coast, northeast to Lake Michigan, east to Nova Scotia, south to Florida, and west to Texas (Wright 1954). American black ducks arrive on their wintering habitats between September and early December and remain there until February to April (Bellrose 1976). Their preferred habitat varies considerably through the wintering range. Habitat use appears related to food availability, freedom from disturbance, weather, and often upon the presence of large bodies of open water. These interrelated elements are essential for meeting the energy demands and other nutritional requirements of black ducks in response to the rigors of cold weather and migration. In the Atlantic Flyway, winter populations of American black ducks concentrate in marine and estuarine wetlands (U.S. Fish and Wildlife Service 1979). They use salt marshes and small tidal bays for feeding and loafing areas. In wintering areas north of Chesapeake Bay, American black ducks frequently feed on tidal flats and rest in emergent wetlands or on ice-free bays, rivers, and coastal reservoirs. In the Chesapeake bay area, migrant and wintering American black ducks occupy a wide variety of habitats (Stewart 1962). They strongly favor brackish bays with extensive adjacent agricultural lands. Estuarine bays, coastal salt marshes, tidal fresh marshes, and adjacent impoundments receive high usage. American black ducks also concentrate in forested wetlands in and adjacent to estuaries in the South Atlantic Flyway, especially in Virginia and North Carolina.

Lewis, James C.; Garrison, Russell L.

1984-01-01

359

Community Ordination Utilizing Winter Stoneflies  

NSDL National Science Digital Library

This exercise in community ecology can be carried out in mid-winter and introduces participants to useful taxonomic and statistical procedures. Species determinations of winter stoneflies are facilitated by a computerized key featuring color illustrations. Taxonomic data are used to construct a two-dimensional ordination of the communities from which specimens were collected. Correlations are then sought between differences exhibited by communities and gradients of environmental conditions.

Vinnedge M. Lawrence (Washington and Jefferson College;)

2008-04-11

360

Changes in hematological profiles during winter field operations  

SciTech Connect

The authors have previously shown that there are changes in hematological profiles during experimental cold acclimation. They now report on hematological changes in 9 military volunteers during a 12 week winter field operation and show results similar to those observed during experimental cold acclimation. Blood was collected before and after completion of winter field operations and analyzed in a paired fashion. Hematocrit (HCT) and erythrocyte counts (RBC) were decreased; mean corpuscular hemoglobin concentration (MCHC) and plasma volume (PV), which was calculated from hemoglobin (Hb) concentration and HCT, were increased. In addition, the reticulocyte count was increased from 1.37 {plus minus} 0.10% to 2.62 {plus minus} 0.24% after completion of field operations. There was a statistically significant inverse correlation between HCT and reticulocyte count, indicating the need for an enhanced rate of red cell production. Hemoglobin concentration, leukocyte count, and mean corpuscular volume were unchanged. The RBC population, to remain at steady state during periods of chronic cold exposure, shows alterations in the number of circulating cells, Hb concentration per cell and possibly cell turnover.

Lopez, A.; Reed, L.; D'Alesandro, M. (Naval Medical Research Inst., Bethesda, MD (United States))

1991-03-11

361

Staying cold through dinner: cold-climate bats rewarm with conspecifics but not sunset during hibernation.  

PubMed

For temperate endotherms (i.e., mammals and birds) energy costs are highest during winter but food availability is lowest and many mammals depend on hibernation as a result. Hibernation is made up of energy-saving torpor bouts [periods of controlled reduction in body temperature (T b)], which are interrupted by brief periodic arousals to normothermic T b. What triggers these arousals in free-ranging hibernators is not well understood. Some temperate bats with intermittent access to flying insects during winter synchronize arousals with sunset, which suggests that, in some species, feeding opportunities influence arousal timing. We tested whether hibernating bats from a cold climate without access to food during winter also maintain a circadian rhythm for arousals or whether cues from conspecifics in the same cluster are more important. We used temperature telemetry to monitor skin temperature (T sk) of free-ranging little brown bats (Myotis lucifugus) hibernating in central Manitoba, Canada, where temperatures from 22 October to 22 March were too cold for flying insects. We found no evidence bats synchronized arousals with photoperiod but they did arouse synchronously with other bats in the same cluster. Thus, in the northern part of their range where flying insects are almost never available during winter, little brown bats exhibit no circadian pattern to arousals. Warming synchronously with others could reduce the energetic costs of arousal for individuals or could reflect disturbance of torpid bats by cluster-mates. PMID:23539327

Czenze, Zenon J; Park, Andrew D; Willis, Craig K R

2013-03-29

362

Front tracking for gas dynamics  

SciTech Connect

Front tracking is an adaptive computational method in which a lower dimensional moving grid is fitted to and follows the dynamical evolution of distinguished waves in a fluid flow. The method takes advantage of known analytic solutions, derived from the Rankine-Hugoniot relations, for idealized discontinuities. In this paper the method is applied to the Euler equations describing compressible gas dynamics. The main thrust here is validation of the front tracking method: we present results on a series of test problems for which comparison answers can be obtained by independent methods.

Chern, I.L.; Glimm, J.; McBryan, O.; Plohr, B.; Yaniv, S.

1984-05-01

363

WINTER-HARDINESS AND DEACCLIMATION BEHAVIOR OF DIVERSE BLUEBERRY (VACCINIUM SPP.) GENOTYPED UNDER FIELD CONDITIONS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Deacclimation response is an important part of adaptative success in blueberries because late-winter thaws followed by hard freezes can cause severe injury to flower buds. A study was undertaken to investigate cold-hardiness and deacclimation behavior under field conditions for 12 diverse blueberry ...

364

Tracking Water Vapor in the Winter High Arctic using the Microwave Humidity Sounder  

Microsoft Academic Search

The cold and dry conditions during the darkness of the winter High Arctic have been a challenge for the retrieval of tropospheric water vapor amounts from satellites. Water vapor remains the most important greenhouse gas even in these dry conditions and so its variability has a direct bearing on the radiative forcing at the surface. The presence of the surface-based

T. J. Duck; G. B. Lesins; J. R. Drummond

2010-01-01

365

Simultaneous Genetic Analysis of Winterhardiness Traits and Development of Winter Malting Barley Varieties  

Technology Transfer Automated Retrieval System (TEKTRAN)

The practical goal of this project is to develop winter malting barley varieties with superior cold tolerance. The basic goal is to advance our understanding of the genetics of low temperature tolerance and vernalization sensitivity. By addressing the question, “Is vernalization sensitivity required...

366

EVIDENCE OF A MAJOR GENETIC FACTOR CONDITIONING FREEZING SENSITIVITY IN WINTER WHEAT  

Technology Transfer Automated Retrieval System (TEKTRAN)

Freezing tolerance was measured in cold-acclimated F2 – derived F4 lines of winter wheat (Triticum aestivum L.) crosses 'Eltan' X Oregon Feed Wheat #5' (ORFW) and 'Tiber' X ORFW. ORFW had essentially no freezing tolerance, while 'Eltan' and 'Tiber' had about 50% survival, as measured in this study....

367

WINTER SOIL MICROCLIMATE ALTERED BY CORN RESIDUE MANAGEMENT IN THE NORTHERN CORN BELT OF THE USA  

Technology Transfer Automated Retrieval System (TEKTRAN)

Frequency and depth of soil freezing, which influence the physical state of soils in cold regions, can be altered by management of crop residues on the soil surface. This study assessed the winter thermal and water characteristics of a Barnes loam subject to no tillage and various residue treatments...

368

Warmth and comfort in the subtropical winter: a study in Brisbane schools.  

PubMed Central

Winter thermal sensations of secondary and primary school-children in Queensland are related to air temperature. Neutrality is estimated by regression analysis of over 6000 assessments and a lower comfort limit is suggested to include 80% of the children. Cold discomfort is seen as the main problem, and comparison is made to an earlier study in England.

Auliciems, A.

1975-01-01

369

Warmth and comfort in the subtropical winter: a study in Brisbane schools.  

PubMed

Winter thermal sensations of secondary and primary school-children in Queensland are related to air temperature. Neutrality is estimated by regression analysis of over 6000 assessments and a lower comfort limit is suggested to include 80% of the children. Cold discomfort is seen as the main problem, and comparison is made to an earlier study in England. PMID:1056961

Auliciems, A

1975-06-01

370

Inoculative freezing promotes winter survival in hatchling diamondback terrapin, Malaclemys terrapin  

Microsoft Academic Search

We investigated the hibernation ecology and cold hardiness of hatchling diamondback terrapins, Malaclemys terrapin (Schoepf, 1793), an estuarine species that reaches 42°N along the Atlantic Ocean. During 3 years of study, about 50% of the nests we monitored harboured hatchlings during winter, and the majority (87%) of these individuals survived despite being intermittently exposed to subfreezing temperatures. Most such exposures

P. J. Baker; J. P. Costanzo; R. Herlands; R. C. Wood

2006-01-01

371

Cold Signaling and Cold Response in Plants  

PubMed Central

Plants are constantly exposed to a variety of environmental stresses. Freezing or extremely low temperature constitutes a key factor influencing plant growth, development and crop productivity. Plants have evolved a mechanism to enhance tolerance to freezing during exposure to periods of low, but non-freezing temperatures. This phenomenon is called cold acclimation. During cold acclimation, plants develop several mechanisms to minimize potential damages caused by low temperature. Cold response is highly complex process that involves an array of physiological and biochemical modifications. Furthermore, alterations of the expression patterns of many genes, proteins and metabolites in response to cold stress have been reported. Recent studies demonstrate that post-transcriptional and post-translational regulations play a role in the regulation of cold signaling. In this review article, recent advances in cold stress signaling and tolerance are highlighted.

Miura, Kenji; Furumoto, Tsuyoshi

2013-01-01

372

Winter lipid depletion of juvenile walleye pollock Theragra chalcogramma in the Doto area, northern Japan.  

PubMed

Seasonal variation in body size and nutritional condition of juvenile walleye pollock Theragra chalcogramma was examined to elucidate the mechanism underlying their first-winter survival on the continental shelf of the Doto area, northern Japan, based on monthly samples collected over 2 years. Stored lipid mass was highest during autumn, but 93% (2004) and 80% (2005) of lipids were exhausted by the onset of winter. Lipid levels in the winter of 2004 remained low (7-14% of the autumnal maximum), and there was reduced growth rate until the spring, whereas in 2005 lipid levels were higher and more variable (10-46% of the maximum) and some growth occurred. An analysis of the allometric relationships between body size and stored energy showed that larger individuals accumulated disproportionately more energy in the autumn, but the advantage disappeared prior to the winter. In January 2004, stored lipid energy was low throughout the Doto continental shelf relative to the continental slope area. These results suggest that winter feeding opportunities on the shelf are severely limited but not completely absent. Previous studies have shown that winter temperatures on the shelf are lower than those in the slope area. It is possible that juvenile T. chalcogramma survive winter on the shelf without a high level of pre-winter lipid storage because the occasional feeding in the cold shelf water benefits energy conservation. PMID:20738491

Kooka, K; Yamamura, O; Ohkubo, N; Honda, S

2009-07-01

373

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

PubMed

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

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

2010-10-01

374

Solar forcing of winter climate variability in the Northern Hemisphere  

NASA Astrophysics Data System (ADS)

An influence of solar irradiance variations on Earth's surface climate has been repeatedly suggested, based on correlations between solar variability and meteorological variables. Specifically, weaker westerly winds have been observed in winters with a less active sun, for example at the minimum phase of the 11-year sunspot cycle. With some possible exceptions, it has proved difficult for climate models to consistently reproduce this signal. Spectral Irradiance Monitor satellite measurements indicate that variations in solar ultraviolet irradiance may be larger than previously thought. Here we drive an ocean-atmosphere climate model with ultraviolet irradiance variations based on these observations. We find that the model responds to the solar minimum with patterns in surface pressure and temperature that resemble the negative phase of the North Atlantic or Arctic Oscillation, of similar magnitude to observations. In our model, the anomalies descend through the depth of the extratropical winter atmosphere. If the updated measurements of solar ultraviolet irradiance are correct, low solar activity, as observed during recent years, drives cold winters in northern Europe and the United States, and mild winters over southern Europe and Canada, with little direct change in globally averaged temperature. Given the quasiregularity of the 11-year solar cycle, our findings may help improve decadal climate predictions for highly populated extratropical regions.

Ineson, Sarah; Scaife, Adam A.; Knight, Jeff R.; Manners, James C.; Dunstone, Nick J.; Gray, Lesley J.; Haigh, Joanna D.

2011-11-01

375

Fossils tell of mild winters in an ancient hothouse  

SciTech Connect

Fossil evidence from the Eocene points to a warmer winter climate in the continental interior (e.g. North Dakota) than that predicted by computer models. Paleobotanists have been able to quantify approximate winter mean temperatures by using leaf characteristics. As one example, leaves from colder climates have toothed edges. Leaf structure was correlated with modern climate regimes, and these relations were then applied to Eocene fossils. They found cold-month mean temperatures of 1-8[degrees]C in Wyoming and Montana, well above model predictions. Climate models can be manipulated to reproduce these temperatures, but not without overheating the entire globe. The problem could be that the Eocene atmospheric circulation was different from today, something not accounted for well by climate models.

Kerr, R.A.

1993-08-06

376

Epidemic carbon monoxide poisoning following a winter storm.  

PubMed

Hospital emergency departments were surveyed to estimate the number of patients treated for carbon monoxide (CO) poisoning after a severe winter storm disrupted electrical service in western Washington State. At least 81 persons were treated. The two main sources of CO were charcoal briquettes (54% of cases) and gasoline-powered electrical generators (40% of cases). Of the 44 persons affected by CO from burning charcoal, 40 (91%) were members of ethnic minority groups; 27 did not speak English. All persons affected by CO from generators were non-Hispanic Whites. This was the largest epidemic of storm-related CO poisoning reported in the United States. This epidemic demonstrated the need to anticipate CO poisoning as a possible consequence of winter storms in cold climates and to make preventive messages understandable to the entire population at risk, including those persons who do not understand written or spoken English. PMID:9279697

Houck, P M; Hampson, N B

377

Front Tracking for Gas Dynamics.  

National Technical Information Service (NTIS)

Front tracking is an adaptive computational method in which a lower dimensional moving grid is fitted to and follows the dynamical evolution of distinguished waves in a fluid flow. The method takes advantage of known analytic solutions, derived from the R...

I. L. Chern J. Glimm O. McBryan B. Plohr S. Yaniv

1984-01-01

378

ALGEBRAIC GRID FRONT MARCHING METHODS  

Microsoft Academic Search

The transfinite interpolation formula of grid generation that employs the Hermite interpolation formula is improved by the addition of a grid front marching method embedded with a simple grid smoother. In the test cases, the proposed method preserved approximate grid orthogonality around all the boundaries and eliminates grid nonsmooth-ness, grid slope discontinuity, and grid overlapping that occurred with the original

Yuan Chang Liou; Yih Nen Jeng

1995-01-01

379

Front-stop photo lenses  

Microsoft Academic Search

Lens systems having external pupil positions are mainly used in connection with optical scanners. In consequence, these so-called f-(Theta) lenses show barrel distortion. This paper, however, is considering the front stop lenses (FS-lenses) poor in distortion and, therefore, suitable for photographic purposes.

Eberhard Dietzsch

1993-01-01

380

Teaching the French Popular Front.  

ERIC Educational Resources Information Center

Examines the French Popular Front of 1936 as a vehicle to investigate the turbulent decade of the 1930s. Reviews current historiography and discusses various facets of Leon Blum's government, examining the interrelationship of major economic and political forces. Concludes that the French Left still faces Blum's dilemma of implementing socialism…

Wall, Irwin M.

1987-01-01

381

Diplomats on the Front Line.  

National Technical Information Service (NTIS)

International terrorism is the name we give to a low-level, world- wide war waged by many groups against many nations on behalf of many causes. It is a war in which diplomats are on the front line. More than 25 percent of all international terrorist incid...

B. M. Jenkins

1982-01-01

382

ARMING THE REVOLUTIONARY UNITED FRONT  

Microsoft Academic Search

On 7 July 1999, the government of Sierra Leone and the Revolutionary United Front (RUF) signed the Lomé Peace Agreement to end the civil war. A central component of this agreement called for the RUF to disarm. A year later, the RUF leader, Foday Sankoh, was in custody and the future of the peace accord in grave doubt. Far from

ERIC G BERMAN

2001-01-01

383

Research for the front lines  

Microsoft Academic Search

It is a truism in the sociology of science that scientific knowledge bears the imprint of particular perspectives, interests, and values. In social science, it is especially common to find that research serves the needs of managers and policymakers better than it serves the needs of front-line workers. This paper analyzes the traces of that tendency in police research. By

David Thacher

2008-01-01

384

Dispatch from the front line  

Microsoft Academic Search

How do you resist commercialization, yet appeal to audiences? How do you keep up with technology, yet not lose the human touch? No one ever said that life on the front line was easy, but where else would planetarians rather be?

J. G. Manning

1996-01-01

385

Modeling cold tolerance in the mountain pine beetle, Dendroctonus ponderosae.  

PubMed

Cold-induced mortality is a key factor driving mountain pine beetle, Dendroctonus ponderosae, population dynamics. In this species, the supercooling point (SCP) is representative of mortality induced by acute cold exposure. Mountain pine beetle SCP and associated cold-induced mortality fluctuate throughout a generation, with the highest SCPs prior to and following winter. Using observed SCPs of field-collected D. ponderosae larvae throughout the developmental season and associated phloem temperatures, we developed a mechanistic model that describes the SCP distribution of a population as a function of daily changes in the temperature-dependent processes leading to gain and loss of cold tolerance. It is based on the changing proportion of individuals in three states: (1) a non cold-hardened, feeding state, (2) an intermediate state in which insects have ceased feeding, voided their gut content and eliminated as many ice-nucleating agents as possible from the body, and (3) a fully cold-hardened state where insects have accumulated a maximum concentration of cryoprotectants (e.g. glycerol). Shifts in the proportion of individuals in each state occur in response to the driving variables influencing the opposite rates of gain and loss of cold hardening. The level of cold-induced mortality predicted by the model and its relation to extreme winter temperature is in good agreement with a range of field and laboratory observations. Our model predicts that cold tolerance of D. ponderosae varies within a season, among seasons, and among geographic locations depending on local climate. This variability is an emergent property of the model, and has important implications for understanding the insect's response to seasonal fluctuations in temperature, as well as population response to climate change. Because cold-induced mortality is but one of several major influences of climate on D. ponderosae population dynamics, we suggest that this model be integrated with others simulating the insect's biology. PMID:17412358

Régnière, Jacques; Bentz, Barbara

2007-03-03

386

Winter- and summertime continental influences on tropospheric O3 and CO observed by TES over the western North Atlantic Ocean  

NASA Astrophysics Data System (ADS)

The distribution of tropospheric O3 and CO and the regulating factors over the western North Atlantic Ocean during winter (December, January, and February, DJF) and summer (June, July, August, JJA) were investigated using retrievals from the Tropospheric Emission Spectrometer (TES) for 2004-2006. Seasonal composites of TES retrievals, reprocessed to remove the artificial geographic and seasonal structure added from the a priori, exhibited strong seasonal differences. At the 681 hPa level during winter composite O3 levels were uniformly low (~45 ppbv), but continental export was evident in a channel of enhanced CO (100-110 ppbv) flowing eastward from the US coast. In summer O3 levels were variable (45-65 ppbv) and generally higher due to increased photochemical production. The main export pathway featured a channel of enhanced CO (95-105 ppbv) flowing northeastward around an anticyclone and exiting the continent over the Canadian Maritimes around 50° N. Offshore O3-CO slopes were generally 0.15-0.20 mol mol-1 in JJA, indicative of photochemical O3 production. Composites for 4 predominant circulation patterns or map types in DJF revealed that export to the lower free troposphere (681 hPa level) was enhanced by the warm conveyor belt (WCB) airstream of cyclones while stratospheric intrusions increased TES O3 levels at 316 hPa. A major finding in the DJF data was that offshore 681 hPa CO levels behind cold fronts could be enhanced up to >150 ppbv likely by lofting from the surface via shallow convection resulting from rapid destabilization of cold air flowing over much warmer ocean waters. In JJA composites for 5 map types showed that the main export pattern of seasonal composites contained the Bermuda High as the dominate feature. However, weak cyclones and frontal troughs could enhance offshore 681 hPa CO levels to greater than 110 ppbv with O3-CO slopes >0.50 mol mol-1 south of 45° N. Intense cyclones, which were not as common in the summer, enhanced export by lofting of boundary layer pollutants from over the US and also provided a possible mechanism for transporting pollutants from boreal fire outflow southward to the US east coast.

Hegarty, J.; Mao, H.; Talbot, R.

2009-11-01

387

Elevated mixing at a front  

NASA Astrophysics Data System (ADS)

The mesoscale, submesoscale, and microscale structure of a front in the California Current was observed using a towed vehicle outfitted with microconductivity sensors. Thirteen >60 km cross-front sections from 0 to 350 m in depth were covered in 3.5 days. Objectively mapped data are fit via the Omega (?) equation to obtain vertical velocity. A composite cross-front section shows elevated mixing on the dense side within 10-20 km of the front. Water downwells and gradients are elevated there: i.e., Rossby number (Ro), horizontal strain (?), spice gradients, and microscale thermal dissipation (?). Thermal eddy diffusivity (KT) reaches 10-3 m2 s-1 and increases 3-10× from the anticyclonic to the cyclonic side with a depth mean of ˜10-4 m2 s-1. The spatial structure of KT, Ro, and ? are similar on the dense side, suggesting an energy cascade from the mesoscale via the submesoscale to the microscale. However, it is unclear whether frontogenesis, internal wave blocking by elevated vorticity, or internal wave trapping by large ? produces the elevated mixing. The mean turbulent heat flux opposes the mean restratifying, mesoscale heat flux of 10 W m-2 and may allow the front to persist. Turbulent nitrate fluxes are 0.1-0.3 mmol m-2 s-1. Chlorophyll fluorescence and beam transmission reveal a <6 km wide, ˜100 km long alongfront streamer which is a deep biomass maximum. Time scales for mixing and nutrient fluxes are 0.3-3 days, which are similar to phytoplankton growth rates and the time scale for frontal evolution.

Johnston, T. M. Shaun; Rudnick, Daniel L.; Pallã S-Sanz, E.

2011-11-01

388

Cold Stress and the Cold Pressor Test  

ERIC Educational Resources Information Center

|Temperature and other environmental stressors are known to affect blood pressure and heart rate. In this activity, students perform the cold pressor test, demonstrating increased blood pressure during a 1- to 2-min immersion of one hand in ice water. The cold pressor test is used clinically to evaluate autonomic and left ventricular function.…

Silverthorn, Dee U.; Michael, Joel

2013-01-01

389

Record low total ozone during northern winters of 1992 and 1993  

SciTech Connect

The authors look at recorded ozone data over the northern hemisphere during the winters of 1992 and 1993. They use data from the World Meteorological Organization data base. During both of these winter, there have been marked decreases in the column ozone levels over North America, Europe, and Siberia, in the latitude belt from 45[degrees]N to 65[degrees]N. During these winters there have been ten times as many days with ozone levels deviated more than 2[sigma] below the 35 year average. They seek explanations for these observations by looking at meterological information. Evidences indicate that there was transport of ozone deficient air masses during these winters. In addition cold air masses with excess ClO show evidence of having transported into the more southern latitudes. The authors conclude there is evidence for both displacement of large air masses, and increased chemical destruction potential, to have contributed to these observed decreases.

Bojkov, R.D. (World Meteorological Organization, Geneva (Switzerland))

1993-07-09

390

Skin Reactions to Cold  

PubMed Central

Although skin reactions to cold are seen surprisingly infrequently in Canada, it is important to manage them correctly when they do occur. Frostbite, cold urticarias, Raynaud's disease and phenomenon, and several miscellaneous changes are discussed.

Talpash, Orest

1976-01-01

391

Coping with Colds  

MedlinePLUS

... hanging out with someone who is smoking. And people who smoke are more likely to catch colds than people ... cold. Stay clear of smokers, too: even secondhand smoke can make people more likely to get sick. Don't use ...

392

Nuclear winter attracts additional scrutiny  

SciTech Connect

Prodded by the Natural Resources Defense Council, Congress has asked the Pentagon to provide what amounts to an environmental impact statement on the potential for nuclear weapons explosions to create enough soot and dust to cause a nuclear winter. The request has implications for arms control and civil defense as well as for weapons procurement and deployment. Little attention was given to the atmospheric and climatic effects of nuclear war until the nuclear winter concept was introduced in October of 1983. Only the Navy and the DOE took steps to follow up until pressure was put on Congress and the Pentagon for further study. Pentagon criticism of the nuclear winter presentation argues that the scenario assumptions that cities will be targeted and that a conflict will involve 5000-6500 megatons are incorrect.

Smith, R.J.

1984-07-06

393

On the relationship between winter thunder and the climatic change in China in the past 2200 years  

Microsoft Academic Search

An analysis of winter thunder records in China from 250 B.C. to A.D. 1900 shows that there is a relationship between the pattern\\u000a of winter thunder frequency fluctuation with that of temperature fluctuation. We hypothesized that such a temperature—thunder\\u000a relationship may possibly be due to the strong frontal movement by cold air masses of well-defined low temperature.

Pao-Kuan Wang

1980-01-01

394

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

395

Physiologically Motivated Front End for Speech Recognition.  

National Technical Information Service (NTIS)

A physiological front-end preprocessor for speech recognition was evaluated using a large isolated word database in noisy and quiet environments. The front end was based on the ensemble interval histogram (EIH) model developed by Oded Ghitza, which provid...

T. K. Nguyen R. P. Lippmann B. Gold D. B. Paul

1991-01-01

396

Interdecadal change in North Korean winter mean rainfall  

NASA Astrophysics Data System (ADS)

In the present study, it was found that there was a significant climate regime shift in 1993 from average rainfall amounts in winter (December of a year and January and February of the next year) in North Korea over the last 30 years (1982-2011). This significant climate regime shift in 1993 also appeared in empirical orthogonal function analysis conducted using the winter mean rainfall amounts observed at 26 weather observation stations in North Korea. The reason why winter mean rainfall amounts in North Korea were smaller during the period of 1994-2011 than during the period of 1982-1994 was that anomalous anticyclone was reinforced in regions near Lake Baikal while anomalous cyclone was reinforced on the sea on the east of Japan so that the winter pressure system pattern (west high-east low pattern) appeared and thus anomalous cold and dry northerlies were reinforced in most East Asian regions including North Korea. To figure out the reason why anomalous anticyclone was reinforced further in the East Asian continent in winters during the period of 1994-2011, differences in water equivalent of accumulated snow depths between the two periods were analyzed. As a result, more snow was observed in most East Asian regions during the period of 1994-2011. Therefore, anomalous anticyclone could be further reinforced in the East Asian continent because surface air temperature dropped further due to snow-albedo effect. The surface air temperature cooling deepened further in the East Asian continent during the period of 1994-2011 due to snow-albedo effect was identified through differences in sensible heat net flux between the two periods.

Choi, Ki-Seon; Kang, Sung-Dae; Kim, Hae-Dong

2013-10-01

397

Chemical depletion of Arctic ozone in winter 1999/2000  

NASA Astrophysics Data System (ADS)

During Arctic winters with a cold, stable stratospheric circulation, reactions on the surface of polar stratospheric clouds (PSCs) lead to elevated abundances of chlorine monoxide (ClO) that, in the presence of sunlight, destroy ozone. Here we show that PSCs were more widespread during the 1999/2000 Arctic winter than for any other Arctic winter in the past two decades. We have used three fundamentally different approaches to derive the degree of chemical ozone loss from ozonesonde, balloon, aircraft, and satellite instruments. We show that the ozone losses derived from these different instruments and approaches agree very well, resulting in a high level of confidence in the results. Chemical processes led to a 70% reduction of ozone for a region ˜1 km thick of the lower stratosphere, the largest degree of local loss ever reported for the Arctic. The Match analysis of ozonesonde data shows that the accumulated chemical loss of ozone inside the Arctic vortex totaled 117 ± 14 Dobson units (DU) by the end of winter. This loss, combined with dynamical redistribution of air parcels, resulted in a 88 ± 13 DU reduction in total column ozone compared to the amount that would have been present in the absence of any chemical loss. The chemical loss of ozone throughout the winter was nearly balanced by dynamical resupply of ozone to the vortex, resulting in a relatively constant value of total ozone of 340 ± 50 DU between early January and late March. This observation of nearly constant total ozone in the Arctic vortex is in contrast to the increase of total column ozone between January and March that is observed during most years.

Rex, M.; Salawitch, R. J.; Harris, N. R. P.; von der Gathen, P.; Braathen, G. O.; Schulz, A.; Deckelmann, H.; Chipperfield, M.; Sinnhuber, B.-M.; Reimer, E.; Alfier, R.; Bevilacqua, R.; Hoppel, K.; Fromm, M.; Lumpe, J.; Küllmann, H.; KleinböHl, A.; Bremer, H.; von KöNig, M.; Künzi, K.; Toohey, D.; VöMel, H.; Richard, E.; Aikin, K.; Jost, H.; Greenblatt, J. B.; Loewenstein, M.; Podolske, J. R.; Webster, C. R.; Flesch, G. J.; Scott, D. C.; Herman, R. L.; Elkins, J. W.; Ray, E. A.; Moore, F. L.; Hurst, D. F.; Romashkin, P.; Toon, G. C.; Sen, B.; Margitan, J. J.; Wennberg, P.; Neuber, R.; Allart, M.; Bojkov, B. R.; Claude, H.; Davies, J.; Davies, W.; de Backer, H.; Dier, H.; Dorokhov, V.; Fast, H.; Kondo, Y.; Kyrö, E.; Litynska, Z.; Mikkelsen, I. S.; Molyneux, M. J.; Moran, E.; Nagai, T.; Nakane, H.; Parrondo, C.; Ravegnani, F.; Skrivankova, P.; Viatte, P.; Yushkov, V.

2002-10-01

398

Firing up the front line.  

PubMed

For many organizations, achieving competitive advantage means eliciting superior performance from employees on the front line--the burger flippers, hotel room cleaners, and baggage handlers whose work has an enormous effect on customers. That's no easy task. Front line workers are paid low wages, have scant hope of advancement, and--not surprisingly--often care little about the company's performance. But then how do some companies succeed in engaging the emotional energy of rank-and-file workers? A team of researchers at McKinsey & Company and the Conference Board recently explored that question and discovered that one highly effective route is demonstrated by the U.S. Marine Corps. The Marines' approach to motivation follows the "mission, values, and pride" path, which researchers say is practical and relevant for the business world. More specifically, the authors say the Marines follow five practices: they over-invest in cultivating core value; prepare every person to lead, including front line supervisors; learn when to create teams and when to create single-leader work groups; attend to all employees, not just the top half; and encourage self-discipline as a way of building pride. The authors admit there are critical differences between the Marines and most businesses. But using vivid examples from companies such as KFC and Marriott International, the authors illustrate how the Marines' approach can be translated for corporate use. Sometimes, the authors maintain, minor changes in a company's standard operating procedure can have a powerful effect on front line pride and can result in substantial payoffs in company performance. PMID:10387573

Katzenbach, J R; Santamaria, J A

399

Structure of Stationary Photodissociation Fronts  

Microsoft Academic Search

The structure of stationary photodissociation fronts is revisited. H2 self-shielding is discussed, including the effects of line overlap. We find that line overlap is important for N(H2) >= 1020 cm-2, with a factor-of-2 suppression of pumping rates at column densities N(H2) 3 x 1020 cm-2 cm-2. We compute multiline UV pumping models and compare these with simple analytic approximations for

B. T. Draine; Frank Bertoldi

1996-01-01

400

Winter Ecology of Buggy Creek Virus (Togaviridae, Alphavirus) in the Central Great Plains  

PubMed Central

Abstract A largely unanswered question in the study of arboviruses is the extent to which virus can overwinter in adult vectors during the cold winter months and resume the transmission cycle in summer. Buggy Creek virus (BCRV; Togaviridae, Alphavirus) is an unusual arbovirus that is vectored primarily by the swallow bug (Hemiptera: Cimicidae: Oeciacus vicarius) and amplified by the ectoparasitic bug's main avian hosts, the migratory cliff swallow (Petrochelidon pyrrhonota) and resident house sparrow (Passer domesticus). Bugs are sedentary and overwinter in the swallows' mud nests. We evaluated the prevalence of BCRV and extent of infection in swallow bugs collected at different times in winter (October–early April) in Nebraska and explored other ecological aspects of this virus's overwintering. BCRV was detected in 17% of bug pools sampled in winter. Virus prevalence in bugs in winter at a site was significantly correlated with virus prevalence at that site the previous summer, but winter prevalence did not predict BCRV prevalence there the following summer. Prevalence was higher in bugs taken from house sparrow nests in winter and (in April) at colony sites where sparrows had been present all winter. Virus detected by reverse transcription (RT)-polymerase chain reaction in winter was less cytopathic than in summer, but viral RNA concentrations of samples in winter were not significantly different from those in summer. Both of the BCRV lineages (A, B) overwintered successfully, with lineage A more common at sites with house sparrows and (in contrast to summer) generally more prevalent in winter than lineage B. BCRV's ability to overwinter in its adult vector probably reflects its adaptation to the sedentary, long-lived bug and the ecology of the cliff swallow and swallow bug host–parasite system. Its overwintering mechanisms may provide insight into those of other alphaviruses of public health significance for which such mechanisms are poorly known.

Strickler, Stephanie A.; Moore, Amy T.; Knutie, Sarah A.; Padhi, Abinash; Brown, Mary Bomberger; Young, Ginger R.; O'Brien, Valerie A.; Foster, Jerome E.; Komar, Nicholas

2010-01-01

401

Disquiet on the eastern front  

Microsoft Academic Search

Even in this more relaxed post-Cold War era, Russia`s leaders believe that nuclear weapons are vital to national security. Maintaining confidence in their safety, security, and reliability is therefore essential. But whether Russia can maintain the necessary level of confidence in the face of economic chaos is uncertain. The Russian nuclear weapons complex, managed by the Ministry of Atomic Energy

Bukharin

1997-01-01

402

Multi Front-End Engineering  

NASA Astrophysics Data System (ADS)

Multi Front-End Engineering (MFE) deals with the design of multiple consistent user interfaces (UI) for one application. One of the main challenges is the conflict between commonality (all front-ends access the same application core) and variability (multiple front-ends on different platforms). This can be overcome by extending techniques from model-driven user interface engineering.We present the MANTRA approach, where the common structure of all interfaces of an application is modelled in an abstract UI model (AUI) annotated with temporal constraints on interaction tasks. Based on these constraints we adapt the AUI, e.g., to tailor presentation units and dialogue structures for a particular platform. We use model transformations to derive concrete, platform-specific UI models (CUI) and implementation code. The presented approach generates working prototypes for three platforms (GUI, web, mobile) integrated with an application core via web service protocols. In addition to static evaluation, such prototypes facilitate early functional evaluations by practical use cases.

Botterweck, Goetz

403

Effects of fluctuations on propagating fronts  

Microsoft Academic Search

Propagating fronts are seen in varieties of nonequilibrium pattern forming systems in Physics, Chemistry and Biology. In the last two decades, many researchers have contributed to the understanding of the underlying dynamics of the propagating fronts. Of these, the deterministic and mean-field dynamics of the fronts were mostly understood in late 1980s and 1990s. On the other hand, although the

Debabrata Panja

2004-01-01

404

Enzymatic activity of rodents acclimated to cold and long scotophase  

NASA Astrophysics Data System (ADS)

Rodents representative of a diurnal species ( Rhabdomys pumilio) as well as a nocturnal species ( Praomys natalensis) were acclimated to cold (Ta = 8°C) at a photoperiod of LD 12:12 and a long scotophase (LD 8; 16) at a temperature of 25° C(Ta). Control groups were kept for both species at Ta = 25° C and LD 12:12 and winter acclimated individuals were obtained during July and August to serve as further reference. Blood samples obtained from the tail were analysed for enzymes representative of three major biochemical pathways. The enzymatic activity of LDH (glycolytic pathway), MDH (Krebs cycle) and G6PDH (hexose monophosphate shunt, as an indicator of gonadal activity) were monitored to represent metabolic activity of the respective cycles. Cold acclimated as well as winter acclimatized mice revealed similar enzymatic patterns for both species and significant increases in LDH and MDH were recorded with a concurrent decrease in G6PDH activity. Specimens exposed to long scotophase exhibited similar enzymatic patterns for both species studied, but enzymatic activity was higher than those of cold acclimated individuals. From these results it is concluded that cold as well as long scotophase induce metabolic adaptations through biochemical activity in the experimental animals. The effect of long scotophase is assumed to be an important factor in the induction of winter acclimatization.

Fourie, F. Le R.; Haim, A.

1980-09-01

405

Deadly Cold: Health Hazards Due to Cold Weather. An Information Paper by the Subcommittee on Health and Long-Term Care of the Select Committee on Aging. House of Representatives, Ninety-Eighth Congress, Second Session (February 1984).  

ERIC Educational Resources Information Center

This paper, on the health hazards of cold weather for elderly persons, presents information from various sources on the death rates in winter throughout the United States. After reviewing the scope of the problem, specific health hazards associated with cold weather are discussed, i.e., hypothermia, fires, carbon monoxide poisoning, and influenza…

Congress of the U.S., Washington, DC. House Select Committee on Aging.

406

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...

407

International scientists on nuclear winter  

Microsoft Academic Search

A report by the International Council of Scientific Unions (ICSU) leads new support to the warning of extreme climatic disruptions that would follow a nuclear war. The two-volume report does not deal explicitly with public policy questions, but focuses on scientific knowledge of physical effects and biological responses. The author reviews studies made since the warning of a nuclear winter

Malone

1985-01-01

408

EPS Workshop on Nuclear Winters  

Microsoft Academic Search

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

D H Parkinson

1988-01-01

409

Select bibliography on nuclear winter  

Microsoft Academic Search

A 1982 article by P.J. Crutzen and J.W. Birks first suggested that smoke from wildland and urban fires could have a significant impact on the atmosphere. The theory of nuclear winter was first presented at the World after Nuclear War conference held in 1983. Following the conference, articles describing the potential climatic and biological consequences of a global nuclear exchange

1987-01-01

410

EPS Workshop on Nuclear Winters  

Microsoft Academic Search

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

D. H. Parkinson

1988-01-01

411

Learning through a Winter's Tale  

ERIC Educational Resources Information Center

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

Vidotto, Kristie

2010-01-01

412

Nuclear Winter Attracts Additional Scrutiny  

Microsoft Academic Search

Prodded by the Natural Resources Defense Council, Congress has asked the Pentagon to provide what amounts to an environmental impact statement on the potential for nuclear weapons explosions to create enough soot and dust to cause a nuclear winter. The request has implications for arms control and civil defense as well as for weapons procurement and deployment. Little attention was

R. Jeffrey Smith

1984-01-01

413

Nuclear Winter: The Continuing Debate.  

National Technical Information Service (NTIS)

This essay examines the debate over the climatic consequences of global nuclear war as related in the so-called Nuclear Winter hypothesis. the review examines the major components of the theory and traces development of the scientific knowledge leading to...

A. V. Nida

1987-01-01

414

Structure of the marine atmospheric boundary layer over an oceanic thermal front: SEMAPHORE experiment  

NASA Astrophysics Data System (ADS)

The Structure des Echanges Mer-Atmosphere, Proprietes des Heterogeneites Oceaniques: Recherche Experimentale (SEMAPHORE) experiment, the third phase of which took place between October 4 and November 17, 1993, was conducted over the oceanic Azores Current located in the Azores basin and mainly marked at the surface by a thermal front due to the gradient of the sea surface temperature (SST) of about 1° to 2°C per 100 km. The evolution of the marine atmospheric boundary layer (MABL) over the SST front was studied with two aircraft and a ship in different meteorological conditions. For each case, the influence of the incoming air direction with respect to the orientation of the oceanic front was taken into account. During the campaign, advanced very high resolution radiometer pictures did not show any relation between the SST field and the cloud cover. The MABL was systematically thicker on the warm side than on the cold side. The mean MABL structure described from aircraft data collected in a vertical plane crossing the oceanic front was characterized by (1) an atmospheric horizontal gradient of 1° to 2°C per 100 km in the whole depth of the mixed layer and (2) an increase of the wind intensity from the cold to the warm side when the synoptic wind blew from the cold side. The surface sensible heat (latent heat) flux always increased from the cold to the warm sector owing to the increase of the wind and of the temperature (specific humidity) difference between the surface and the air. Turbulence increased from the cold to the warm side in conjunction with the MABL thickening, but the normalized profiles presented the same structure, regardless of the position over the SST front. In agreement with the Action de Recherche Programme te Petite Echelle and Grande Echelle model, the mean temperature and momentum budgets were highly influenced by the horizontal temperature gradient. In particular, the strong ageostrophic influence in the MABL above the SST front seems linked with the secondary circulation due to the SST front.

Kwon, B. H.; BéNech, B.; Lambert, D.; Durand, P.; Druilhet, A.; Giordani, H.; Planton, S.

1998-10-01

415

Water masses, ocean fronts, and the structure of Antarctic seabird communities: Putting the eastern Bellingshausen Sea in perspective  

NASA Astrophysics Data System (ADS)

Waters off the western Antarctic Peninsula (i.e., the eastern Bellingshausen Sea) are unusually complex owing to the convergence of several major fronts. Determining the relative influence of fronts on occurrence patterns of top-trophic species in that area, therefore, has been challenging. In one of the few ocean-wide seabird data syntheses, in this case for the Southern Ocean, we analyzed ample, previously collected cruise data, Antarctic-wide, to determine seabird species assemblages and quantitative relationships to fronts as a way to provide context to the long-term Palmer LTER and the winter Southern Ocean GLOBEC studies in the eastern Bellingshausen Sea. Fronts investigated during both winter (April-September) and summer (October-March) were the southern boundary of the Antarctic Circumpolar Current (ACC), which separates the High Antarctic from the Low Antarctic water mass, and within which are embedded the marginal ice zone and Antarctic Shelf Break Front; and the Antarctic Polar Front, which separates the Low Antarctic and the Subantarctic water masses. We used clustering to determine species' groupings with water masses, and generalized additive models to relate species' densities, biomass and diversity to distance to respective fronts. Antarctic-wide, in both periods, highest seabird densities and lowest species diversity were found in the High Antarctic water mass. In the eastern Bellingshausen, seabird density in the High Antarctic water mass was lower (as low as half that of winter) than found in other Antarctic regions. During winter, Antarctic-wide, two significant species groups were evident: one dominated by Adélie penguins ( Pygoscelis adeliae) (High Antarctic water mass) and the other by petrels and prions (no differentiation among water masses); in eastern Bellingshausen waters during winter, the one significant species group was composed of species from both Antarctic-wide groups. In summer, Antarctic-wide, a High Antarctic group dominated by Adélie penguins, a Low Antarctic group dominated by petrels, and a Subantarctic group dominated by albatross were evident. In eastern Bellingshausen waters during summer, groups were inconsistent. With regard to frontal features, Antarctic-wide in winter, distance to the ice edge was an important explanatory factor for nine of 14 species, distance to the Antarctic Polar Front for six species and distance to the Shelf Break Front for six species; however, these Antarctic-wide models could not successfully predict spatial relationships of winter seabird density (individual species or total) and biomass in the eastern Bellingshausen. Antarctic-wide in summer, distance to land/Antarctic continent was important for 10 of 18 species, not a surprising result for these summer-time Antarctic breeders, as colonies are associated with ice-free areas of coastal land. Distance to the Shelf Break Front was important for 8 and distance to the southern boundary of the ACC was important for 7 species. These summer models were more successful in predicting eastern Bellingshausen species density and species diversity but failed to predict total seabird density or biomass. Antarctic seabirds appear to respond to fronts in a way similar to that observed along the well-studied upwelling front of the California Current. To understand fully the seabird patterns found in this synthesis, multi-disciplinary at-sea investigations, including a quantified prey field, are needed.

Ribic, Christine A.; Ainley, David G.; Glenn Ford, R.; Fraser, William R.; Tynan, Cynthia T.; Woehler, Eric J.

2011-07-01

416

COMPARATIVE ANALYSIS OF EXPRESSED SEQUENCE TAGS FROM COLD ACCLIMATED AND NON-ACCLIMATED LEAVES OF RHODODENDRON CATAWBIENSE MICHX  

Technology Transfer Automated Retrieval System (TEKTRAN)

Technical Summary An expressed sequence tag (EST) analysis approach was undertaken to identify major genes involved in cold acclimation of Rhododendron, a broad-leaf, woody evergreen species. Two cDNA libraries were constructed, one from winter-collected (cold acclimated, CA; leaf freezing toleranc...

417

Modeling winter hydrological processes under differing climatic conditions: Modifying WEPP  

NASA Astrophysics Data System (ADS)

Water erosion is a serious and continuous environmental problem worldwide. In cold regions, soil freeze and thaw has great impacts on infiltration and erosion. Rain or snowmelt on a thawing soil can cause severe water erosion. Of equal importance is snow accumulation and snowmelt, which can be the predominant hydrological process in areas of mid- to high latitudes and forested watersheds. Modelers must properly simulate winter processes to adequately represent the overall hydrological outcome and sediment and chemical transport in these areas. Modeling winter hydrology is presently lacking in water erosion models. Most of these models are based on the functional Universal Soil Loss Equation (USLE) or its revised forms, e.g., Revised USLE (RUSLE). In RUSLE a seasonally variable soil erodibility factor (K) was used to account for the effects of frozen and thawing soil. Yet the use of this factor requires observation data for calibration, and such a simplified approach cannot represent the complicated transient freeze-thaw processes and their impacts on surface runoff and erosion. The Water Erosion Prediction Project (WEPP) watershed model, a physically-based erosion prediction software developed by the USDA-ARS, has seen numerous applications within and outside the US. WEPP simulates winter processes, including snow accumulation, snowmelt, and soil freeze-thaw, using an approach based on mass and energy conservation. However, previous studies showed the inadequacy of the winter routines in the WEPP model. Therefore, the objectives of this study were: (1) To adapt a modeling approach for winter hydrology based on mass and energy conservation, and to implement this approach into a physically-oriented hydrological model, such as WEPP; and (2) To assess this modeling approach through case applications to different geographic conditions. A new winter routine was developed and its performance was evaluated by incorporating it into WEPP (v2008.9) and then applying WEPP to four study sites at different spatial scales under different climatic conditions, including experimental plots in Pullman, WA and Morris, MN, two agricultural drainages in Pendleton, OR, and a forest watershed in Mica Creek, ID. The model applications showed promising results, indicating adequacy of the mass- and energy-balance-based approach for winter hydrology simulation.

Dun, Shuhui

418

Shock-front broadening in polycrystalline materials  

NASA Astrophysics Data System (ADS)

We analyze a model for the evolution of shock fronts in polycrystalline materials. This model is based on the idea of Meyers and Carvalho [Mater. Sci. Eng. 24, 131 (1976)] that the shock velocity anisotropy within the polycrystal is the most important factor in shock front broadening. Our analysis predicts that the shock front width increases as the 1/2 power of the front penetration distance into the crystal. Our theoretical prediction is in plausible agreement with previous experimental results for the elastic precursor rise time, and it should therefore provide a useful shock width estimate. Furthermore, our theoretical framework is also applicable to other problems involving front propagation in heterogeneous media.

Barber, J. L.; Kadau, K.

2008-04-01

419

Effects of weather on habitat selection and behavior of mallards wintering in Nebraska  

USGS Publications Warehouse

Sex and age ratios, habitat selection, spatial characteristics, and time budgets of Mallards (Anas platyrhynchos) wintering on the Platte River in south central Nebraska were studied from mid-December to early April 1978-1980. The proportion of females and subadults in the population increased substantially from a cold to a mild winter. Radio-tagged Mallards shifted from riverine to canal roost sites during the coldest periods of the winter, seemingly because of more favorable microclimatic conditions there. Subadults ranged over larger areas during winter than did adults. Activity patterns varied with weather conditions, time of day, and habitat type. During cold periods, energetically costly activities such as aggression and courtship decreased at roost sites and the intensity of foraging activities in fields increased. Mallards were more active at riverine than canal sites during both years. High energy requirements and intense competition for scarce food appear to be primary factors limiting the northernmost distribution of Mallards in winter and causing their skewed sex and age ratios.

Jorde, D. G.; Krapu, G. L.; Crawford, R. D.; Hay, M. A.

1984-01-01

420

Convection in stable and unstable fronts.  

PubMed

Density gradients across a reaction front can lead to convective fluid motion. Stable fronts require a heavier fluid on top of a lighter one to generate convective fluid motion. On the other hand, unstable fronts can be stabilized with an opposing density gradient, where the lighter fluid is on top. In this case, we can have a stable flat front without convection or a steady convective front of a given wavelength near the onset of convection. The fronts are described with the Kuramoto-Sivashinsky equation coupled to hydrodynamics governed by Darcy's law. We obtain a dispersion relation between growth rates and perturbation wave numbers in the presence of a density discontinuity accross the front. We also analyze the effects of this density change in the transition to chaos. PMID:22400643

Elliott, Drew; Vasquez, Desiderio A

2012-01-18

421

Convection in stable and unstable fronts  

NASA Astrophysics Data System (ADS)

Density gradients across a reaction front can lead to convective fluid motion. Stable fronts require a heavier fluid on top of a lighter one to generate convective fluid motion. On the other hand, unstable fronts can be stabilized with an opposing density gradient, where the lighter fluid is on top. In this case, we can have a stable flat front without convection or a steady convective front of a given wavelength near the onset of convection. The fronts are described with the Kuramoto-Sivashinsky equation coupled to hydrodynamics governed by Darcy's law. We obtain a dispersion relation between growth rates and perturbation wave numbers in the presence of a density discontinuity accross the front. We also analyze the effects of this density change in the transition to chaos.

Elliott, Drew; Vasquez, Desiderio A.

2012-01-01

422

Unusual Southern Hemisphere Stratosphere Winter of 2002.  

National Technical Information Service (NTIS)

The southern hemisphere stratospheric winter of 2002 was the most unusual winter yet observed in the southern hemisphere climate record. Temperatures near the edge of the Antarctic polar vortex were considerably warmer than normal over the entire course o...

P. A. Newman E. R. Nash

2003-01-01

423

Winter Operations-Abrasives and Salt Brine.  

National Technical Information Service (NTIS)

The primary objective of winter maintenance operations is to improve traffic safety and efficiency during winter storm periods. Abrasives and salt brines have been successfully applied to increase traction and prevent snow and ice from bonding to road sur...

G. Pesti Y. Liu

2003-01-01

424

Seasonal forecasts of northern hemisphere winter 2009/10  

NASA Astrophysics Data System (ADS)

Northern hemisphere winter 2009/10 was exceptional for atmospheric circulation: the North Atlantic Oscillation (NAO) index was the lowest on record for over a century. This contributed to cold conditions over large areas of Eurasia and North America. Here we use two versions of the Met Office GloSea4 seasonal forecast system to investigate the predictability of this exceptional winter. The first is the then operational version of GloSea4, which uses a low top model and successfully predicted a negative NAO in forecasts produced in September, October and November 2009. The second uses a new high top model, which better simulates sudden stratospheric warmings (SSWs). This is particularly relevant for 2009/10 due to its unusual combination of a strong El Niño and an easterly quasi-biennial oscillation (QBO) phase, favouring SSW development. SSWs are shown to play an influential role in surface conditions, producing a stronger sea level pressure signal and improving predictions of the 2009/10 winter.

Fereday, D. R.; Maidens, A.; Arribas, A.; Scaife, A. A.; Knight, J. R.

2012-09-01

425

Solar forcing of winter climate variability in the northern hemisphere  

NASA Astrophysics Data System (ADS)

Observational evidence indicates a link between the 11-year solar cycle and wintertime climate of the Northern Hemisphere. Here we use the Hadley Centre coupled ocean-atmosphere climate model in idealized experiments which represent the impact of the change in the ultraviolet (UV) component only of solar forcing on the difference in climate between the solar maximum and solar minimum. The UV perturbation is estimated from extrapolation of recent SIM/SORCE satellite data and is larger than that derived from earlier measurements. Our model responds with a clear signal throughout the depth of the extratropical winter atmosphere, with a surface response to solar minimum resembling the negative phase of the North Atlantic Oscillation/Arctic Oscillation. This allows low solar activity to drive cold winters in northern Europe and the U.S. and mild winters over southern Europe and Canada with little direct change in globally averaged temperature. The resulting surface climate anomalies are large enough to play an important role in decadal climate prediction.

Ineson, S.; Scaife, A. A.; Knight, J. R.; Manners, J. C.; Dunstone, N. J.; Gray, L. J.; Haigh, J. D.

2012-04-01

426

Winter in a Svalbard Fiord Ecosystem  

Microsoft Academic Search

Data pertaining to the characteristics of an arctic fiord in winter were collected at the Polish Arctic Station situated in Hornsund at 77ON, 15OE on Svalbard. Winter in the fiord was defined in terms of climate (November-May), hydrology (January-March) and biology (November-March). The characteristic phenomena of winter in the fiord include a winter drop in the yearly biomass maximum to

J. M. WESLAWSKI; S. KWASNIEWSKI; J. WIKTOR

1991-01-01

427

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.

1998-01-01

428

Fluctuating pulled fronts and Pomerons  

SciTech Connect

I present a pedagogical discussion of the influence of particle number fluctuations on the high energy evolution in QCD. I emphasize the event-by-event description, and the correspondence with the problem of 'fluctuating pulled fronts' in statistical physics. I explain that the correlations generated by fluctuations reduce the phase-space for BFKL evolution up to saturation. Because of that, the evolution 'slows down', and the rate for the energy increase of the saturation momentum is considerably decreased. I also discuss the diagrammatic interpretation of the particle number fluctuations in terms of Pomeron loops.

Iancu, Edmond [Service de Physique Theorique, CEA/DSM/SPhT, Unite de recherche associee au CNRS, CE Saclay, F-91191 Gif-sur-Yvette (France)

2005-06-14

429

1. VIEW SOUTHWARD FROM SOUTHWEST CORNER FRONT AND ARCH STREETS ...  

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

1. VIEW SOUTHWARD FROM SOUTHWEST CORNER FRONT AND ARCH STREETS (2. N. Front Street starts at left) - North Front Street Area Study, 2-66 North Front Street (Commercial Buildings), Philadelphia, Philadelphia County, PA

430

Evolution of Fronts in the Mid-Atlantic Bight: What Exit on the Ocean Highway Off New Jersey?  

NASA Astrophysics Data System (ADS)

The New Jersey Shelf Observing System (NJSOS), a regional ocean observatory, is currently deployed in the New York Bight as part of the larger NorthEast Observing System (NEOS). Remote sensing data from an international constellation of satellites and a CODAR-type HF radar surface current array provide continuous synoptic surface maps over the shelf. For 2002 and 2003, full resolution NOAA AVHRR (~1 km) and SeaWiFS (~1.1 km, 4th reprocessing) imagery of the New York Bight region were averaged into time composites from 4 to 90 days. Long-range current maps were similarly averaged to match the scales of the satellite composites. Long-term averages of surface currents in the MAB indicate two transport pathways to the outer shelf. One originates near the mouth of New York Harbor and moves out along the Hudson Canyon. The second, originating upshelf, enters the field from the north and moves slowly toward the south. The flow along the Hudson Canyon is an alternative pathway that is a more direct transport to the shelf/slope region of the MAB. The sea surface temperature over the Hudson Canyon shows similar links to the canyon topography with cold inner shelf water following the 50 m isobath, and warmer water offshore. Similarly there is a lower chlorophyll concentration over the canyon than in the surrounding water. Although the temperature signature in the New York Bight is strongest in the winter, CODAR and surface chlorophyll measurements indicate the Hudson Canyon front occurs year round and can have significant influences on cross-shelf transport of organic material.

Kohut, J. T.; Bosch, J. A.; Schofield, O.; Glenn, S. M.

2004-12-01

431

On the simulation of winter precipitation types  

Microsoft Academic Search

Winter storms produce major problems for society, and the key responsible factor is often the varying types of precipitation. The objective of this study is to better understand the formation of different types of winter precipitation (freezing rain, ice pellets, snow, slush, wet snow and refrozen wet snow) within the varying and interacting environmental conditions in many winter storms. To

J. M. Thériault; R. E. Stewart; J. A Milbrandt; M. K. Yau

2006-01-01

432

Isolation and functional characterization of cold-regulated promoters, by digitally identifying peach fruit cold-induced genes from a large EST dataset  

PubMed Central

Background Cold acclimation is the process by which plants adapt to the low, non freezing temperatures that naturally occur during late autumn or early winter. This process enables the plants to resist the freezing temperatures of winter. Temperatures similar to those associated with cold acclimation are also used by the fruit industry to delay fruit ripening in peaches. However, peaches that are subjected to long periods of cold storage may develop chilling injury symptoms (woolliness and internal breakdown). In order to better understand the relationship between cold acclimation and chilling injury in peaches, we isolated and functionally characterized cold-regulated promoters from cold-inducible genes identified by digitally analyzing a large EST dataset. Results Digital expression analyses of EST datasets, revealed 164 cold-induced peach genes, several of which show similarities to genes associated with cold acclimation and cold stress responses. The promoters of three of these cold-inducible genes (Ppbec1, Ppxero2 and Pptha1) were fused to the GUS reporter gene and characterized for cold-inducibility using both transient transformation assays in peach fruits (in fruta) and stable transformation in Arabidopsis thaliana. These assays demonstrate that the promoter Pptha1 is not cold-inducible, whereas the Ppbec1 and Ppxero2 promoter constructs are cold-inducible. Conclusion This work demonstrates that during cold storage, peach fruits differentially express genes that are associated with cold acclimation. Functional characterization of these promoters in transient transformation assays in fruta as well as stable transformation in Arabidopsis, demonstrate that the isolated Ppbec1 and Ppxero2 promoters are cold-inducible promoters, whereas the isolated Pptha1 promoter is not cold-inducible. Additionally, the cold-inducible activity of the Ppbec1 and Ppxero2 promoters suggest that there is a conserved heterologous cold-inducible regulation of these promoters in peach and Arabidopsis. These results reveal that digital expression analyses may be used in non-model species to identify candidate genes whose promoters are differentially expressed in response to exogenous stimuli.

Tittarelli, Andres; Santiago, Margarita; Morales, Andrea; Meisel, Lee A; Silva, Herman

2009-01-01

433

Excess winter mortality in Europe: a cross country analysis identifying key risk factors  

PubMed Central

Objective: Much debate remains regarding why certain countries experience dramatically higher winter mortality. Potential causative factors other than cold exposure have rarely been analysed. Comparatively less research exists on excess winter deaths in southern Europe. Multiple time series data on a variety of risk factors are analysed against seasonal-mortality patterns in 14 European countries to identify key relations Subjects and setting: Excess winter deaths (all causes), 1988–97, EU-14. Design: Coefficients of seasonal variation in mortality are calculated for EU-14 using monthly mortality data. Comparable, longitudinal datasets on risk factors pertaining to climate, macroeconomy, health care, lifestyle, socioeconomics, and housing were also obtained. Poisson regression identifies seasonality relations over time. Results: Portugal suffers from the highest rates of excess winter mortality (28%, CI=25% to 31%) followed jointly by Spain (21%, CI=19% to 23%), and Ireland (21%, CI=18% to 24%). Cross country variations in mean winter environmental temperature (regression coefficient (ß)=0.27), mean winter relative humidity (ß=0.54), parity adjusted per capita national income (ß=1.08), per capita health expenditure (ß=-1.19), rates of income poverty (ß=-0.47), inequality (ß=0.97), deprivation (ß=0.11), and fuel poverty (ß=0.44), and several indicators of residential thermal standards are found to be significantly related to variations in relative excess winter mortality at the 5% level. The strong, positive relation with environmental temperature and strong negative relation with thermal efficiency indicate that housing standards in southern and western Europe play strong parts in such seasonality. Conclusions: High seasonal mortality in southern and western Europe could be reduced through improved protection from the cold indoors, increased public spending on health care, and improved socioeconomic circumstances resulting in more equitable income distribution.

Healy, J

2003-01-01

434

Impacts of Convective Gravity Wave Drag in the Southern Hemisphere Winter Stratosphere  

NASA Astrophysics Data System (ADS)

Excessive cold pole and stronger polar vortex in the southern hemisphere (SH) winter stratosphere are the long-lasting problem in most general circulation models (GCMs). Recent studies show that this problem is related to the underestimated model wave drag in the SH winter extratropical stratosphere, especially by underestimated or missing gravity wave drag (GWD) in the SH. Convective GWD is one of the major missing GWDs in most current GCMs that could significantly influence on the temperature and polar vortex in the SH winter stratosphere. Cumulus convection is strong in the storm track regions of the winter extratropics as well as in the tropics, and thus convectively induced gravity waves provide substantial wave drag in the SH winter stratosphere. The non-orographic GWD parameterizations that do not consider specific sources may not realistically represent the GWD in those specific regions. In this study, we use the Whole Atmosphere Community Climate Model (WACCM) and show that the temperature and wind biases in the SH winter stratosphere of the model in the June-August (JJA) climatology are significantly alleviated by including two convective gravity wave drag (GWDC) parameterizations (a columnar scheme and a ray-based scheme). The reduction in the wind biases is due to directly the addition of GWDC in the SH midlatitudes and indirectly the enhanced resolved wave drag in response to GWDC. The enhanced wave drag also improves the springtime breakdown of the SH vortex that delayed in the simulation without GWDC. The cold temperature biases are alleviated by increased downwelling in the SH winter polar regions, which stems from an increased poleward motion due to the enhanced wave drag in the midlatitudes.

Choi, H.-J.; Chun, H.-Y.

2012-04-01

435

Dynamical influence of the Tibetan Plateau on the winter monsoon over southeastern Asia  

NASA Astrophysics Data System (ADS)

Previous studies have shown (1) that the Tibetan Plateau produces a significant fraction of the two components of the Equatorial Mountain Torque (EMT) in winter, (2) that these torques are in part related to the East Asian cold surges, and (3) that the cold surges affect the convection over the maritime continent. We show here that these relations are strong enough for the convection over the Equatorial South China Sea to be associated with significant signals on the two components of the EMT that can precede by a few days and more the convection. These signals are associated to surface pressure and temperature patterns that are strongly reminiscent of the East Asian cold surges. Our results therefore show that the Tibetan Plateau couple dynamically the midlatitudes and the tropical region, and that the vectors of this dynamical coupling are the cold surges. This coupling also influences the convection over the northern Bay of Bengal, mainland southeast Asia, and Indonesia.

Mailler, Sylvain; Lott, François

2009-03-01

436

Overwintering Strategy and Mechanisms of Cold Tolerance in the Codling Moth (Cydia pomonella)  

PubMed Central

Background The codling moth (Cydia pomonella) is a major insect pest of apples worldwide. Fully grown last instar larvae overwinter in diapause state. Their overwintering strategies and physiological principles of cold tolerance have been insufficiently studied. No elaborate analysis of overwintering physiology is available for European populations. Principal Findings We observed that codling moth larvae of a Central European population prefer to overwinter in the microhabitat of litter layer near the base of trees. Reliance on extensive supercooling, or freeze-avoidance, appears as their major strategy for survival of the winter cold. The supercooling point decreases from approximately ?15.3°C during summer to ?26.3°C during winter. Seasonal extension of supercooling capacity is assisted by partial dehydration, increasing osmolality of body fluids, and the accumulation of a complex mixture of winter specific metabolites. Glycogen and glutamine reserves are depleted, while fructose, alanine and some other sugars, polyols and free amino acids are accumulated during winter. The concentrations of trehalose and proline remain high and relatively constant throughout the season, and may contribute to the stabilization of proteins and membranes at subzero temperatures. In addition to supercooling, overwintering larvae acquire considerable capacity to survive at subzero temperatures, down to ?15°C, even in partially frozen state. Conclusion Our detailed laboratory analysis of cold tolerance, and whole-winter survival assays in semi-natural conditions, suggest that the average winter cold does not represent a major threat for codling moth populations. More than 83% of larvae survived over winter in the field and pupated in spring irrespective of the overwintering microhabitat (cold-exposed tree trunk or temperature-buffered litter layer).

Rozsypal, Jan; Kostal, Vladimir; Zahradnickova, Helena; Simek, Petr

2013-01-01

437

Preventing cold-related morbidity and mortality in a changing climate.  

PubMed

Winter weather patterns are anticipated to become more variable with increasing average global temperatures. Research shows that excess morbidity and mortality occurs during cold weather periods. We critically reviewed evidence relating temperature variability, health outcomes, and adaptation strategies to cold weather. Health outcomes included cardiovascular-, respiratory-, cerebrovascular-, and all-cause morbidity and mortality. Individual and contextual risk factors were assessed to highlight associations between individual- and neighborhood-level characteristics that contribute to a person's vulnerability to variability in cold weather events. Epidemiologic studies indicate that the populations most vulnerable to variations in cold winter weather are the elderly, rural and, generally, populations living in moderate winter climates. Fortunately, cold-related morbidity and mortality are preventable and strategies exist for protecting populations from these adverse health outcomes. We present a range of adaptation strategies that can be implemented at the individual, building, and neighborhood level to protect vulnerable populations from cold-related morbidity and mortality. The existing research justifies the need for increased outreach to individuals and communities for education on protective adaptations in cold weather. We propose that future climate change adaptation research couple building energy and thermal comfort models with epidemiological data to evaluate and quantify the impacts of adaptation strategies. PMID:21592693

Conlon, Kathryn C; Rajkovich, Nicholas B; White-Newsome, Jalonne L; Larsen, Larissa; O'Neill, Marie S

2011-05-17

438

Preventing cold-related morbidity and mortality in a changing climate  

PubMed Central

Winter weather patterns are anticipated to become more variable with increasing average global temperatures. Research shows that excess morbidity and mortality occurs during cold weather periods. We critically reviewed evidence relating temperature variability, health outcomes, and adaptation strategies to cold weather. Health outcomes included cardiovascular-, respiratory-, cerebrovascular-, and all-cause morbidity and mortality. Individual and contextual risk factors were assessed to highlight associations between individual- and neighborhood- level characteristics that contribute to a person’s vulnerability to variability in cold weather events. Epidemiologic studies indicate that the populations most vulnerable to variations in cold winter weather are the elderly, rural and, generally, populations living in moderate winter climates. Fortunately, cold-related morbidity and mortality are preventable and strategies exist for protecting populations from these adverse health outcomes. We present a range of adaptation strategies that can be implemented at the individual, building, and neighborhood level to protect vulnerable populations from cold-related morbidity and mortality. The existing research justifies the need for increased outreach to individuals and communities for education on protective adaptations in cold weather. We propose that future climate change adaptation research couple building energy and thermal comfort models with epidemiological data to evaluate and quantify the impacts of adaptation strategies.

Conlon, Kathryn C; Rajkovich, Nicholas B; White-Newsome, Jalonne L; Larsen, Larissa; Neill, Marie S O

2011-01-01

439

Changes in the East Asian cold season since 2000  

NASA Astrophysics Data System (ADS)

Using NCEP-NCAR reanalysis data and observational data from meteorological stations in China, the evolution of the East Asian cold season (EACS) and its long-term changes after 2000 were studied. A monsoon tendency index (MTI), defined as the temporal difference of the East Asian monsoon index, indicates that the winter monsoon setup has been postponed in autumn, while the setup has quickened in early winter. In mid winter, the EACS breakdown process has accelerated, while it has lingered in late winter. The authors suggest that the postponement of monsoon setup in autumn may be caused by strong global warming at the lower levels, which further limits the setup time period and leads to the quickening of the setup process in early winter. Meanwhile, a north-south seesaw of temperature tendency change in China can be observed in December and February, which may be related to large-scale circulation changes in the stratosphere, characterized by a polar warming in mid winter and polar cooling in early spring. This linkage is possibly caused by the dynamical coupling between stratosphere and troposphere, via the variation of planetary wave activities. In spring, the speed of the EACS breakdown has decreased, which favors the revival of the EACS in East Asia.

Wei, Ke; Chen, Wen; Zhou, Wen

2011-01-01

440

Winter production of CO 2 and N 2 O from alpine tundra: environmental controls and relationship to inter-system C and N fluxes  

Microsoft Academic Search

Fluxes of CO2 and N2O were measured from both natural and experimentally augmented snowpacks during the winters of 1993 and 1994 on Niwot Ridge\\u000a in the Colorado Front Range. Consistent snow cover insulated the soil surface from extreme air temperatures and allowed heterotrophic\\u000a activity to continue through much of the winter. In contrast, soil remained frozen at sites with inconsistent

Paul D. Brooks; Steven K. Schmidt; Mark W. Williams

1997-01-01