These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

HF Doppler and VHF radar observations of upper atmospheric disturbances caused by weak cold front during winter time  

NASA Technical Reports Server (NTRS)

The simultaneous use of the Taiwan VHF radar and the HF Doppler sounder for remote measurement of three-dimensional winds, gravity waves, and density perturbations at mesospheric and thermospheric heights is demonstrated. A special event of atmospheric disturbances caused by propagating gravity waves excited by weak convective motions in winter time were investigated. The three-dimensional wind velocities at different heights were determined, and the frequency, horizontal wavelength, vertical wavelength, and phase velocity of the gravity waves were measured. The subtropical, low-latitude site makes the VHF radar and HF Doppler array systems unique, and the observations especially valuable for space projects dealing with low-latitude atmosphere.

Hung, R. J.; Lee, C. C.; Gao, M.; Johnson, D. L.; Yang, F. W.

1990-01-01

2

Cold fronts in cool core clusters  

E-print Network

Cold fronts have been detected both in merging and in cool core clusters, where little or no sign of a merging event is present. A systematic search of sharp surface brightness discontinuities performed on a sample of 62 galaxy clusters observed with XMM-Newton shows that cold fronts are a common feature in galaxy clusters. Indeed most (if not all) of the nearby clusters (z cold front. Understanding the origin and the nature of a such frequent phenomenon is clearly important. To gain insight on the nature of cold fronts in cool core clusters we have undertaken a systematic study of all contact discontinuities detected in our sample, measuring surface brightness, temperature and when possible abundance profiles across the fronts. We measure the Mach numbers for the cold fronts finding values which range from 0.2 to 0.9; we also detect a discontinuities in the metal profile of some clusters.

S. Ghizzardi; S. Molendi; M. Rossetti; A. Leccardi

2006-11-13

3

Metal Enrichment Discriminators of Cold Fronts  

E-print Network

Cold fronts are sharp surface brightness discontinuities characterized by a jump in gas temperature accompanied by a decline in X-ray surface brightness such that the gas pressure remains continuous across the front and, thus, these structures differ from bow shocks. Models suggest that cold fronts can be generated by external mechanisms involving the accretion of a subsystem with a remnant "cold core". However, internal mechanisms can also create cold fronts, such as gravitational scattering of subclumps or cD oscillation around the bottom of the potential well. These competing models for their formation can be discriminated through the measurements of the SN Type contamination across the front, which in turn can be determined from metal abundance ratios as measured from an ensemble of elements. Here we present the preliminary results of such analysis using a sample of clusters observed with Chandra.

Renato Dupke

2005-11-18

4

Metal Enrichment Discriminators of Cold Fronts  

E-print Network

Cold fronts are sharp surface brightness discontinuities characterized by a jump in gas temperature accompanied by a decline in X-ray surface brightness such that the gas pressure remains continuous across the front and, thus, these structures differ from bow shocks. Models suggest that cold fronts can be generated by external mechanisms involving the accretion of a subsystem with a remnant "cold core". However, internal mechanisms can also create cold fronts, such as gravitational scattering of subclumps or cD oscillation around the bottom of the potential well. These competing models for their formation can be discriminated through the measurements of the SN Type contamination across the front, which in turn can be determined from metal abundance ratios as measured from an ensemble of elements. Here we present the preliminary results of such analysis using a sample of clusters observed with Chandra.

Dupke, R

2005-01-01

5

Low-Level Cloud Response to the Gulf Stream1 Front in Winter using CALIPSO2  

E-print Network

_cloud_text_r1.docx #12;2 Abstract23 A sharp sea surface temperature front develops between the warm water of the Gulf24 Stream and cold continental shelf water in boreal winter. This front has a substantial25 impact through sea level pressure adjustment with ascending33 motion over the warm water and descending motion

Xie, Shang-Ping

6

Cloud Vertical Distribution across Warm and Cold Fronts in CloudSatCALIPSO Data and a General Circulation Model  

E-print Network

of the relationship between the cloudiness and relative humidity fields in- dicates that water vapor is not lifted extratropical warm and cold fronts are obtained using two consecutive winters of CloudSat­Cloud­Aerosol Lidar

7

Cold Microphysics in California Winter Precipitation  

NASA Astrophysics Data System (ADS)

Numerical simulation of two Sierra Nevada wintertime precipitation events by the MM5 model is verified with available microphysical and surface precipitation data. The role of cold microphysical processes in modulating surface precipitation variability is investigated together with the sensitivity of surface precipitation to various microphysical factors associated with cold microphysical processes. In addition to the verification of the simulated precipitation and wind field for these two winter precipitation cases, the verification of the microphysical properties simulated by the GSFC ice microphysics scheme in the MM5 model is new in this work. We describe a methodology to relate model simulated cloud microphysical variables, such as the mixing ratios of rain, snow, graupel, cloud ice, and cloud water, to the observed or estimated variables from cloud microphysical probes such as 1D-C, 2D-C, and 2D-P. It is found that without the Hallett-Mossop ice multiplication process the GSFC ice microphysical scheme fails to reproduce the observed dense cloud ice particle region around -5aC in two cases. The inclusion of this second cloud ice production processes in the model microphysics scheme helps to reproduce this detected region with the order of magnitude of simulated number concentration of cloud ice being close to the observed by the 1D-C and 2D-C probes. This indicates that this ice-producing process is vital for accurate simulation of microphysical properties although its existence increases by only 5% the mean areal precipitation in the Folsom Lake basin for the two case studies. In addition, it is found that the simulation of number concentration of precipitating particles depends on the accurate selection of the intercept N0 of snow particle size distribution. This parameter can modify mean area precipitation in the Folsom Lake basin by about 7- 10%, that is, more significantly than the Hallett-Mossop process. Division of precipitation types and comparison between the simulations with/without the riming process reveal that (a) graupel (or rimed snow) is the dominant precipitation type especially in the windward slope and (b) the riming process is critical for distributing precipitation in the direction normal to barrier. This suggests parameterizing graupel riming in microphysics schemes and investigating its effects on the improvement of QPF.

Wang, J.; Georgakakos, K. P.

2006-12-01

8

Cyclone and cold front evolution over the Intermountain West  

NASA Astrophysics Data System (ADS)

Over the Intermountain West, cyclones and cold fronts can bring about dramatic sensible weather changes that impact the rapidly growing population of the region, yet the basic mechanisms contributing to their intensification and evolution are not well understood. This dissertation investigates these mechanisms using a multi-faceted approach that includes observational analysis, real-data model simulations, and idealized model simulations. Chapter 2 presents an observational analysis of the 15 Apr 2002 Tax Day Storm, which featured the strongest cyclone and cold front to pass through Salt Lake City, Utah in recent history. In particular, we establish the role of a newly identified feature, the Great Basin Confluence Zone (GBCZ), in cyclone and frontal evolution. This region of contraction (confluent deformation and divergence) extends downstream from the Sierra Nevada and is initially nonfrontal, but becomes the locus for frontogenesis and cyclogenesis. Chapter 3 uses real-data and idealized modeling studies to examine the role of the Sierra Nevada in Intermountain cold front evolution. Using model simulations of another strong case of Intermountain frontogenesis from 25 Mar 2006 with and without the Sierra Nevada, we show that the range produces a leeward warm anomaly, increasing the cross-front potential temperature contrast, and also enhances contraction along the front. Idealized baroclinic wave simulations in which we vary the initial cyclone position are used to show how the influence of the Sierra Nevada varies for differing synoptic patterns and frontal orientations. This work advances our understanding of the mechanisms important to cyclone and frontal evolution over mountainous terrain and should contribute to improved analysis and forecasting of cyclones and fronts over the Intermountain West.

West, Gregory Lucas

9

Fast Simulations of Gas Sloshing and Cold Front Formation  

NASA Technical Reports Server (NTRS)

We present a simplified and fast method for simulating minor mergers between galaxy clusters. Instead of following the evolution of the dark matter halos directly by the N-body method, we employ a rigid potential approximation for both clusters. The simulations are run in the rest frame of the more massive cluster and account for the resulting inertial accelerations in an optimised way. We test the reliability of this method for studies of minor merger induced gas sloshing by performing a one-to-one comparison between our simulations and hydro+N-body ones. We find that the rigid potential approximation reproduces the sloshing-related features well except for two artifacts: the temperature just outside the cold fronts is slightly over-predicted, and the outward motion of the cold fronts is delayed by typically 200 Myr. We discuss reasons for both artifacts.

Roediger, E.; ZuHone, J. A.

2012-01-01

10

Fast Simulations of Gas Sloshing and Cold Front Formation  

NASA Technical Reports Server (NTRS)

We present a simplified and fast method for simulating minor mergers between galaxy clusters. Instead of following the evolution of the dark matter halos directly by the N-body method, we employ a rigid potential approximation for both clusters. The simulations are run in the rest frame of the more massive cluster and account for the resulting inertial accelerations in an optimised way. We test the reliability of this method for studies of minor merger induced gas sloshing by performing a one-to-one comparison between our simulations and hydro+N-body ones. We find that the rigid potential approximation reproduces the sloshing-related features well except for two artefacts: the temperature just outside the cold fronts is slightly over-predicted, and the outward motion of the cold fronts is delayed by typically 200 Myr. We discuss reasons for both artefacts.

Roediger, E.; ZuHone, J. A.

2011-01-01

11

Nitrogen and phosphorus distributions across the thermohaline front in Kii Channel in winter  

Microsoft Academic Search

We have studied nitrogen and phosphorus distributions across the thermohaline front in Kii Channel in winter by using engine-cooling sea water of a ferry boat. On Dec. 1986 and Jan. 1987, differences of PO4?P and DIN across the front are recognized. Especially in the latter case, differences of nutrients concentrations across the front are very obvious. But differences of nutrients

Ichiro Yuasa; Eisuke Hashimoto; Hideki Ueshima

1993-01-01

12

On a theory of the evolution of surface cold fronts  

NASA Technical Reports Server (NTRS)

The governing vorticity and divergence equations in the surface layer are derived and the roles of the different terms and feedback mechanisms are investigated in semigeostrophic and nongeostrophic cold-frontal systems. A planetary boundary layer model is used to perform sensitivity tests to determine that in a cold front the ageostrophic feedback mechanism as defined by Orlanski and Ross tends to act as a positive feedback mechanism, enhancing vorticity and convergence growth. Therefore, it cannot explain the phase shift between convergence and vorticity as simulated by Orlanski and Ross. An alternative plausible, though tentative, explanation in terms of a gravity wave is offered. It is shown that when the geostrophic deformation increases, nonlinear terms in the divergence equation may become important and further destabilize the system.

Levy, Gad; Bretherton, Christopher S.

1987-01-01

13

A Review of Cold Fronts with Prefrontal Troughs and Wind Shifts DAVID M. SCHULTZ  

E-print Network

in Friedman (1989, 128­134) for more information on the short-lived forerunner.] A dif- ferent type of coldA Review of Cold Fronts with Prefrontal Troughs and Wind Shifts DAVID M. SCHULTZ Cooperative The conceptual model of a classical surface-based cold front consists of a sharp temperature decrease coincident

Schultz, David

14

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

15

Habitat suitability index models: greater white-fronted goose (wintering). [Anser albifrons  

Microsoft Academic Search

A review and synthesis of available information were used to develop models for indexing the potential suitability of agricultural and natural wetland habitats for wintering white-fronted geese (Anser albifrons). The model is scaled to produce indices of habitat suitability from 0 (unsuitable habitat) to 1.0 (optimal habitat) primarily for wintering habitat in southwest Louisiana and southwest Texas. Habitat suitability indices

Kaminski

1986-01-01

16

A HIGH FIDELITY SAMPLE OF COLD FRONT CLUSTERS FROM THE CHANDRA ARCHIVE  

SciTech Connect

This paper presents a sample of 'cold front' clusters selected from the Chandra archive. The clusters are selected based purely on the existence of surface brightness edges in their Chandra images which are modeled as density jumps. A combination of the derived density and temperature jumps across the fronts is used to select nine robust examples of cold front clusters: 1ES0657 - 558, Abell 1201, Abell 1758N, MS1455.0+2232, Abell 2069, Abell 2142, Abell 2163, RXJ1720.1+2638, and Abell 3667. This sample is the subject of an ongoing study aimed at relating cold fronts to cluster merger activity, and understanding how the merging environment affects the cluster constituents. Here, temperature maps are presented along with the Chandra X-ray images. A dichotomy is found in the sample in that there exists a subsample of cold front clusters which are clearly mergers based on their X-ray morphologies, and a second subsample of clusters which harbor cold fronts, but have surprisingly relaxed X-ray morphologies, and minimal evidence for merger activity at other wavelengths. For this second subsample, the existence of a cold front provides the sole evidence for merger activity at X-ray wavelengths. We discuss how cold fronts can provide additional information which may be used to constrain merger histories, and also the possibility of using cold fronts to distinguish major and minor mergers.

Owers, Matt S. [School of Physics, University of New South Wales, Sydney, NSW 2052 (Australia); Nulsen, Paul E. J.; Markevitch, Maxim [Harvard Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Couch, Warrick J., E-mail: mowers@astro.swin.edu.a [Center for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn, VIC 3122 (Australia)

2009-10-20

17

Thermohaline front at the mouth of Tokyo Bay in winter  

Microsoft Academic Search

A detailed structure of the remarkable thermohaline front, which exists from late autumn to early spring at the mouth of Tokyo Bay, Japan, is investigated by the field observation and the simple numerical experiment. The fresh, cool and nutrient-rich coastal water and the salty, warm and nutrient-poor offshore water converge in the surface layer at the thermohaline front. These two

T. Yanagi; A. Isobe; T. Saino; T. Ishimaru

1989-01-01

18

Rapid uplift of nonmethane hydrocarbons in a cold front over central Europe  

E-print Network

Rapid uplift of nonmethane hydrocarbons in a cold front over central Europe R. M. Purvis,1 A. C between the PBL and FT was observed for all short and medium lifetime hydrocarbons (e.g., average iso of a cold front, a rapid uplift of reactive carbon from the boundary layer to the mid free troposphere

Hoskins, Brian

19

Effect of a Simulated Cold-Front on Hatching Success of Yellow Perch Eggs  

E-print Network

Effect of a Simulated Cold-Front on Hatching Success of Yellow Perch Eggs Andrew C. Jansena, Brian (Perea jlavescens) egg and larval stages has been associated with stronger year classes, whereas an abrupt drop in temperature associated with a cold-front during this period can result in weaker

20

Influence of the Gulf Stream on the Barents Sea ice retreat and Eurasian coldness during early winter  

NASA Astrophysics Data System (ADS)

Abnormal sea-ice retreat over the Barents Sea during early winter has been considered a leading driver of recent midlatitude severe winters over Eurasia. However, causal relationships between such retreat and the atmospheric circulation anomalies remains uncertain. Using a reanalysis dataset, we found that poleward shift of a sea surface temperature front over the Gulf Stream likely induces warm southerly advection and consequent sea-ice decline over the Barents Sea sector, and a cold anomaly over Eurasia via planetary waves triggered over the Gulf Stream region. The above mechanism is supported by the steady atmospheric response to the diabatic heating anomalies over the Gulf Stream region obtained with a linear baroclinic model. The remote atmospheric response from the Gulf Stream would be amplified over the Barents Sea region via interacting with sea-ice anomaly, promoting the warm Arctic and cold Eurasian pattern.

Sato, Kazutoshi; Inoue, Jun; Watanabe, Masahiro

2014-08-01

21

Habitat suitability index models: greater white-fronted goose (wintering). [Anser albifrons  

SciTech Connect

A review and synthesis of available information were used to develop models for indexing the potential suitability of agricultural and natural wetland habitats for wintering white-fronted geese (Anser albifrons). The model is scaled to produce indices of habitat suitability from 0 (unsuitable habitat) to 1.0 (optimal habitat) primarily for wintering habitat in southwest Louisiana and southwest Texas. Habitat suitability indices are designed for use with Habitat Evaluations Procedures previously developed by the US Fish and Wildlife Service.

Kaminski, R.M.

1986-07-01

22

A link between reduced Barents-Kara sea ice and cold winter extremes over northern continents  

Microsoft Academic Search

The recent overall Northern Hemisphere warming was accompanied by several severe northern continental winters, as for example, extremely cold winter 20052006 in Europe and northern Asia. Here we show that anomalous decrease of wintertime sea ice concentration in the Barents-Kara (B-K) seas could bring about extreme cold events like winter 20052006. Our simulations with the ECHAM5 general circulation model demonstrate

Vladimir Petoukhov; Vladimir A. Semenov

2010-01-01

23

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 dore. The vectors 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; Thiry, Denis

2009-07-01

24

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

PubMed

The leafhopper Scaphoideus titanus is the vector of a major phytoplasma grapevine disease, Flavescence dore. 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 degrees 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. PMID:19401803

Chuche, Julien; Thiry, Denis

2009-07-01

25

THE PROPERTIES OF X-RAY COLD FRONTS IN A STATISTICAL SAMPLE OF SIMULATED GALAXY CLUSTERS  

SciTech Connect

We examine the incidence of cold fronts in a large sample of galaxy clusters extracted from a (512 h {sup -1} Mpc) hydrodynamic/N-body cosmological simulation with adiabatic gas physics computed with the Enzo adaptive mesh refinement code. This simulation contains a sample of roughly 4000 galaxy clusters with M {>=}10{sup 14} M{sub sun} at z = 0. For each simulated galaxy cluster, we have created mock 0.3-8.0 keV X-ray observations and spectroscopic-like temperature maps. We have searched these maps with a new automated algorithm to identify the presence of cold fronts in projection. Using a threshold of a minimum of 10 cold front pixels in our images, corresponding to a total comoving length L{sub cf}>156 h {sup -1} kpc, we find that roughly 10%-12% of all projections in a mass-limited sample would be classified as cold front clusters. Interestingly, the fraction of clusters with extended cold front features in our synthetic maps of a mass-limited sample trends only weakly with redshift out to z = 1.0. However, when using different selection functions, including a simulated flux limit, the trending with redshift changes significantly. The likelihood of finding cold fronts in the simulated clusters in our sample is a strong function of cluster mass. In clusters with M>7.5 x 10{sup 14} M{sub sun} the cold front fraction is 40%-50%. We also show that the presence of cold fronts is strongly correlated with disturbed morphology as measured by quantitative structure measures. Finally, we find that the incidence of cold fronts in the simulated cluster images is strongly dependent on baryonic physics.

Hallman, Eric J.; Skillman, Samuel W.; Smith, Britton D.; Burns, Jack O. [Center for Astrophysics and Space Astronomy, Department of Astrophysics and Planetary Sciences, University of Colorado at Boulder, Boulder, CO 80309 (United States); Jeltema, Tesla E. [UCO/Lick Observatories, 1156 High St., Santa Cruz, CA 95064 (United States); O'Shea, Brian W. [Department of Physics and Astronomy and Lyman Briggs College, Michigan State University, East Lansing, MI 48824 (United States); Norman, Michael L., E-mail: ehallman@cfa.harvard.ed [Center for Astrophysics and Space Sciences, University of California at San Diego, La Jolla, CA 92093 (United States)

2010-12-10

26

The Central American cold surge: an observational analysis of the deep southward penetration of North American cold fronts  

E-print Network

studies of cold fmnts in Central America, frequency estimates were ambiguous, simply ranging from rare to common. Maximum equatorward penetration estimates were more specific, but just as varied, ranging from central Nicaragua (Portig, 1976; Snow, 1976...THE CENTRAL AMERICAN COLD SURGE: AN OBSERVATIONAL ANALYSIS OF THE DEEP SOUTHWARD PENETRATION OF NORTH AMERICAN COLD FRONTS A Thesis by PHILIP JOHN REDING Submitted to the Office of Graduate Studies of Texas A &M University in partial...

Reding, Philip John

2012-06-07

27

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

Microsoft Academic Search

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

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

1992-01-01

28

Winter Habitat Preferences for Florida Manatees and Vulnerability to Cold  

PubMed Central

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.

2013-01-01

29

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

2013-01-01

30

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

NASA Astrophysics Data System (ADS)

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

Milligan, William James, IV

31

Know before you go. Don't get left out in the cold. Prepare your vehicle for winter weather.  

E-print Network

Know before you go. Don't get left out in the cold. Prepare your vehicle for winter weather. Do you drive during winter? Winter weather is hard on your vehicle and its engine. Here are some tips to help tire air pressure frequently, as it decreases in cold weather. 2. Get your car winter ready

Kavanagh, Karen L.

32

Three-dimensional Magnetohydrodynamic Simulations of Cold Fronts in Magnetically Turbulent ICM  

E-print Network

Steep gradients of temperature and density, called cold fronts, are observed by Chandra in a leading edge of subclusters moving through the intracluster medium (ICM). The presence of cold fronts indicates that thermal conduction across the front is suppressed by magnetic fields. We carried out three-dimensional magnetohydrodynamic (MHD) simulations including anisotropic thermal conduction of a subcluster moving through a magnetically turbulent ICM. We found that turbulent magnetic fields are stretched and amplified by shear flows along the interface between the subcluster and the ambient ICM. Since magnetic fields reduce the efficiency of thermal conduction across the front, the cold front survives at least 1 Gyr. We also found that a moving subcluster works as an amplifier of magnetic fields. Numerical results indicate that stretched turbulent magnetic fields accumulate behind the subcluster and are further amplified by vortex motions. The moving subcluster creates a long tail of ordered magnetic fields, in which the magnetic field strength attains plasma beta < 10.

Naoki Asai; Naoya Fukuda; Ryoji Matsumoto

2007-03-20

33

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

34

COLD FRONTS AND GAS SLOSHING IN GALAXY CLUSTERS WITH ANISOTROPIC THERMAL CONDUCTION  

SciTech Connect

Cold fronts in cluster cool cores should be erased on short timescales by thermal conduction, unless protected by magnetic fields that are 'draped' parallel to the front surfaces, suppressing conduction perpendicular to the sloshing fronts. We present a series of MHD simulations of cold front formation in the core of a galaxy cluster with anisotropic thermal conduction, exploring a parameter space of conduction strengths parallel and perpendicular to the field lines. Including conduction has a strong effect on the temperature distribution of the core and the appearance of the cold fronts. Though magnetic field lines are draping parallel to the front surfaces, preventing conduction directly across them, the temperature jumps across the fronts are nevertheless reduced. The geometry of the field is such that the cold gas below the front surfaces can be connected to hotter regions outside via field lines along directions perpendicular to the plane of the sloshing motions and along sections of the front that are not perfectly draped. This results in the heating of this gas below the front on a timescale of a Gyr, but the sharpness of the density and temperature jumps may nevertheless be preserved. By modifying the gas density distribution below the front, conduction may indirectly aid in suppressing Kelvin-Helmholtz instabilities. If conduction along the field lines is unsuppressed, we find that the characteristic sharp jumps seen in Chandra observations of cold front clusters do not form. Therefore, the presence of cold fronts in hot clusters is in contradiction with our simulations with full Spitzer conduction. This suggests that the presence of cold fronts in hot clusters could be used to place upper limits on conduction in the bulk of the intracluster medium. Finally, the combination of sloshing and anisotropic thermal conduction can result in a larger flux of heat to the core than either process in isolation. While still not sufficient to prevent a cooling catastrophe in the very central (r {approx} 5 kpc) regions of the cool core (where something else is required, such as active galactic nucleus feedback), it reduces significantly the mass of gas that experiences a cooling catastrophe outside those small radii.

ZuHone, J. A.; Markevitch, M. [Astrophysics Science Division, Laboratory for High Energy Astrophysics, Code 662, NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States)] [Astrophysics Science Division, Laboratory for High Energy Astrophysics, Code 662, NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Ruszkowski, M. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States)] [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States); Lee, D. [The Flash Center for Computational Science, The University of Chicago, 5747 S. Ellis, Chicago, IL 60637 (United States)] [The Flash Center for Computational Science, The University of Chicago, 5747 S. Ellis, Chicago, IL 60637 (United States)

2013-01-10

35

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

36

Magnetohydrodynamic Simulations of the Formation of Cold Fronts in Clusters of Galaxies including Heat Conduction  

E-print Network

Recent Chandra observations of clusters of galaxies revealed the existence of a sharp ridge in the X-ray surface brightness where the temperature drops across the front. This front is called the cold front. We present the results of two-dimensional magnetohydrodynamic simulations of the time evolution of a dense subcluster plasma moving in a cluster of galaxies. Anisotropic heat conduction along the magnetic field lines is included. In the models without magnetic fields, the numerical results indicate that the heat conduction from the hot ambient plasma heats the cold dense plasma of the subcluster and diffuses out the cold front. When magnetic fields exist in a cluster of galaxies, however, cold fronts can be maintained because the heat conduction across the magnetic field lines is suppressed. We found that, even when the magnetic fields in a cluster of galaxies are disordered, heat conduction across the front is restricted because the magnetic field lines are stretched along the front. Numerical results reproduced the X-ray intensity distribution observed in the A3667 cluster of galaxies.

Naoki Asai; Naoya Fukuda; Ryoji Matsumoto

2004-04-07

37

Arctic Oscillation and Cold Surge in the Northern Hemisphere at 2009\\/2010 Winter  

Microsoft Academic Search

The cause of the cold surge occurred at 2009\\/2010 winter over northern hemisphere was investigated. During the boreal winter (December-January-February) of 2009\\/2010, the surface temperature was extremely lower than normal years by more than 5C over North-east Asia, Europe, and North America. The cold air outbreak was due to the stronger northerly winds in troposphere at mid latitudes associated with

S. Kim; B. Kim; H. Lee; Y. Kim

2010-01-01

38

Cold truths: how winter drives responses of terrestrial organisms to climate change.  

PubMed

Winter is a key driver of individual performance, community composition, and ecological interactions in terrestrial habitats. Although climate change research tends to focus on performance in the growing season, climate change is also modifying winter conditions rapidly. Changes to winter temperatures, the variability of winter conditions, and winter snow cover can interact to induce cold injury, alter energy and water balance, advance or retard phenology, and modify community interactions. Species vary in their susceptibility to these winter drivers, hampering efforts to predict biological responses to climate change. Existing frameworks for predicting the impacts of climate change do not incorporate the complexity of organismal responses to winter. Here, we synthesise organismal responses to winter climate change, and use this synthesis to build a framework to predict exposure and sensitivity to negative impacts. This framework can be used to estimate the vulnerability of species to winter climate change. We describe the importance of relationships between winter conditions and performance during the growing season in determining fitness, and demonstrate how summer and winter processes are linked. Incorporating winter into current models will require concerted effort from theoreticians and empiricists, and the expansion of current growing-season studies to incorporate winter. PMID:24720862

Williams, Caroline M; Henry, Hugh A L; Sinclair, Brent J

2015-02-01

39

Arctic Oscillation and the Northern Hemisphere Cold Surge at 2009\\/2010 Winter  

Microsoft Academic Search

The cause of the cold surge occurred at 2009\\/2010 winter over northern hemisphere was investigated. During December 2009, the surface temperature was extremely lower by more than 10C over parts of northern hemisphere. The cold air outbreak was due to the stronger northerly winds in troposphere at mid latitudes associated with the substantially weaker Arctic Oscillation (AO) polarity with the

S.-J. Kim; B.-M. Kim; H.-H. Lee; Y.-J. Kim

2010-01-01

40

Chandra Analysis of Abell 496 - No Chemical Gradients Across Cold Fronts  

E-print Network

We present the results of a spatially-resolved spectroscopic analysis of the galaxy cluster Abell 496 with the S3 chip on-board the Chandra satellite. We confirm the presence of a central positive temperature gradient consistent with a cooling flow, but with a minimum gas temperature of ~0.5-0.9 keV. The cluster also exhibits sharp edges in gas density and temperature which are consistent with "cold front" substructures. The iron abundance profile is not radially symmetric relative to the cluster center. Towards the direction of the most prominent (northerly) cold front, the iron abundance is roughly flat, with nearly solar values. In the opposite (southerly) direction from the center, the iron abundance distribution shows an "off-center" peak. Various abundance ratios suggest that the heavy elements in the central regions of the cluster are dominated by SN Ia ejecta. However, for radii greater than 100 kpc, the abundance ratios vary in such a way that different abundance ratios provide very different estimates of the proportion of SN Ia/II ejecta. Nonetheless, observed abundances and abundance ratios are continuous across the cold fronts, which suggests that the cold fronts are not likely to be the result of a subcluster merger. We suggest instead that the cold fronts in A496 are caused by "sloshing" of the central cooling flow gas, induced by the motion of the cD about the cluster center.

Renato A. Dupke; Raymond E. White III

2002-12-13

41

The Effect of Viscosity on Sloshing Cold Fronts in Galaxy Clusters  

NASA Astrophysics Data System (ADS)

Cold fronts, which are contact discontinuities in the intracluster medium of galaxy clusters, should be disrupted by Kelvin-Helmholtz instabilities. However, most cold fronts appear to be very smooth and the signatures of significant disruption by instabilities appear to be absent. Therefore, cold fronts may be used to place constraints on ICM viscosity. We perform numerical simulations of gas sloshing in galaxy cluster cores using the Athena MHD code, comparing the effects of isotropic Spitzer viscosity and anisotropic Braginskii viscosity on the gas properties. We find that simulations with anisotropic Braginskii viscosity or isotropic Spitzer viscosity with a suppression factor of f 0.1 give results that are very close to the observations in terms of suppressing K-H instabilities. Using synthetic X-ray observations, we show it is difficult to distinguish between these two models. This suggests that the combination of magnetic fields and Braginskii viscosity is sufficient to explain the observed smoothness of sloshing cold fronts. We find that sloshing-driven turbulence is only modestly reduced by Braginskii viscosity. We also perform simulations including anisotropic thermal conduction. We find that including Braginskii viscosity in these simulations has no effect on the evolution of cold fronts; they are smeared out by thermal conduction.

ZuHone, J.; Markevitch, M.; Stone, J.; Kunz, M.; Biffi, V.

2014-07-01

42

Researchers Probe Why Colds Are More Likely in Winter  

MedlinePLUS

... 2015) Tuesday, January 6, 2015 Related MedlinePlus Page Common Cold TUESDAY, Jan. 6, 2015 (HealthDay News) -- Though it's ... to beat back the rhinovirus that causes the common cold. "It has been long known that the rhinovirus ...

43

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?gn; kke? Atc; Barbaros Nalbanto?lu

2003-01-01

44

Chitinase genes responsive to cold encode antifreeze proteins in winter cereals.  

PubMed

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. PMID:11080301

Yeh, S; Moffatt, B A; Griffith, M; Xiong, F; Yang, D S; Wiseman, S B; Sarhan, F; Danyluk, J; Xue, Y Q; Hew, C L; Doherty-Kirby, A; Lajoie, G

2000-11-01

45

The Effect of Anisotropic Viscosity on Cold Fronts in Galaxy Clusters  

NASA Astrophysics Data System (ADS)

Cold frontscontact discontinuities in the intracluster medium (ICM) of galaxy clustersshould be disrupted by Kelvin-Helmholtz (K-H) instabilities due to the associated shear velocity. However, many observed cold fronts appear stable. This opens the possibility of placing constraints on microphysical mechanisms that stabilize them, such as the ICM viscosity and/or magnetic fields. We performed exploratory high-resolution simulations of cold fronts arising from subsonic gas sloshing in cluster cores using the grid-based Athena MHD code, comparing the effects of isotropic Spitzer and anisotropic Braginskii viscosity (expected in a magnetized plasma). Magnetized simulations with full Braginskii viscosity or isotropic Spitzer viscosity reduced by a factor f ~ 0.1 are both in qualitative agreement with observations in terms of suppressing K-H instabilities. The rms velocity of turbulence within the sloshing region is only modestly reduced by Braginskii viscosity. We also performed unmagnetized simulations with and without viscosity and find that magnetic fields have a substantial effect on the appearance of the cold fronts, even if the initial field is weak and the viscosity is the same. This suggests that determining the dominant suppression mechanism of a given cold front from X-ray observations (e.g., viscosity or magnetic fields) by comparison with simulations is not straightforward. Finally, we performed simulations including anisotropic thermal conduction, and find that including Braginskii viscosity in these simulations does not significantly affect the evolution of cold fronts; they are rapidly smeared out by thermal conduction, as in the inviscid case.

ZuHone, J. A.; Kunz, M. W.; Markevitch, M.; Stone, J. M.; Biffi, V.

2015-01-01

46

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 Fhr, 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.

Bttger, Heike; Nehls, Georg; Witte, Sophia

2011-12-01

47

Geographic variation in migration chronology and winter distribution of midcontinent greater white-fronted geese  

USGS Publications Warehouse

We evaluated spatial and temporal differences in migratory behavior among different breeding groups of midcontinent greater white-fronted geese (Anser albifrons) using band-recovery data and observations of neck collared geese during migration and winter. Birds from different breeding areas were initially delineated by geographic distance into 6 banding reference areas (BRAs): 1) interior Alaska, 2) North Slope of Alaska, 3) western Northwest Territories (NWT), 4) western Nunavut, 5) central Nunavut, and 6) eastern Nunavut. The banding groups also differed by breeding habitat, with geese from interior Alaska nesting in the boreal forest (taiga), and all other groups breeding in tundra habitats. Geese from interior Alaska migrated earlier during autumn, and were more likely to winter farther south (in Mexico) than geese from other breeding areas. Geese banded in central and eastern Nunavut (Queen Maud Gulf and Inglis River) wintered farther east (in Louisiana) than geese from other breeding areas. Small-scale (within-state) geographic segregation of wintering flocks was evidenced by the recent (post-1990) nearly exclusive use of a new wintering area in north central Texas by geese from interior Alaska. Segregation among BRAs was also apparent in Mexico, where taiga geese were found predominantly in the central Highlands (states of Zacatecas and Durango), whereas tundra geese mostly used states along the Gulf Coast (primarily Tamaulipas). Interior Alaska birds initiated spring migration earlier than geese from other areas, and were more likely than others to stop in the Rainwater Basin of Nebraska, a region where cholera outbreaks periodically kill thousands of geese. Geese from interior Alaska were the first to arrive at spring staging areas in prairie Canada where BRAs exhibited spatial delineation (a longitudinal cline) in relation to breeding areas. Our results show significant geographic and temporal variation among taiga and tundra breeding cohorts during autumn, winter, and spring. Temporal and spatial differences in migratory behavior may allow management practices that accommodate potential demographic differences between taiga and tundra populations.

Ely, Craig R.; Nieman, Daniel J.; Alisauskas, Ray T.; Schmutz, Joel A.; Hines, James E.

2013-01-01

48

Unusually cold and dry winters increase mortality in Australia.  

PubMed

Seasonal patterns in mortality have been recognised for decades, with a marked excess of deaths in winter, yet our understanding of the causes of this phenomenon is not yet complete. Research has shown that low and high temperatures are associated with increased mortality independently of season; however, the impact of unseasonal weather on mortality has been less studied. In this study, we aimed to determine if unseasonal patterns in weather were associated with unseasonal patterns in mortality. We obtained daily temperature, humidity and mortality data from 1988 to 2009 for five major Australian cities with a range of climates. We split the seasonal patterns in temperature, humidity and mortality into their stationary and non-stationary parts. A stationary seasonal pattern is consistent from year-to-year, and a non-stationary pattern varies from year-to-year. We used Poisson regression to investigate associations between unseasonal weather and an unusual number of deaths. We found that deaths rates in Australia were 20-30% higher in winter than summer. The seasonal pattern of mortality was non-stationary, with much larger peaks in some winters. Winters that were colder or drier than a typical winter had significantly increased death risks in most cities. Conversely summers that were warmer or more humid than average showed no increase in death risks. Better understanding the occurrence and cause of seasonal variations in mortality will help with disease prevention and save lives. PMID:25460613

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

2015-01-01

49

The influence of subtropical cold fronts on the surface energy balance of a semi-arid site  

Microsoft Academic Search

The passage of subtropical cold fronts through central Australia produces the only significant mesoscale meteorological features in the region. The interaction of these cold fronts with the surface energy balance strongly affects the local weather and climate. The surface energy balance was measured at a semi-arid site in Alice Springs, central Australia, to determine how it was influenced by the

Jason Beringer; Nigel J. Tapper

2000-01-01

50

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

E-print Network

Export of Asian pollution during two cold front episodes of the TRACE-P experiment C. Mari how these cyclonic systems have impacted the export of pollution out of the Asian continent. We of pollution are met during flight 13 (i.e., the occurrences of the warm conveyor belt near the source regions

Palmer, Paul

51

Hydrodynamic Simulations of A Moving Substructure in A Cluster of Galaxies: Cold Fronts and Turbulence Generation  

E-print Network

We perform three dimensional hydrodynamical simulations of a moving substructure in a cluster of galaxies. We investigate dynamical evolution of the intracluster medium (ICM) in and around the substructure moving radially in the larger cluster's gravitational potential, and its observational consequences. After the substructure passes the larger cluster's center, a bow shock and clear contact discontinuity form in front of it. The contact discontinuity looks like a sharp cold front in the X-ray image synthesized from the simulation results. This agrees with a structure found in 1E 0657-56. The flow structure remains laminar before the first turnaround because the ram-pressure stripping is dominant over the development of Kelvin-Helmholtz instabilities on the boundary between the substructure and the ambient ICM. When a subcluster oscillates radially around the larger cluster's center, both Kelvin-Helmholtz and Rayleigh-Taylor instabilities develop well and the flow structure becomes highly turbulent. Around the turnaround, the subcluster's cold gas is pushed out of its potential well. Therefore, the cold gas component appears to be in front of the subcluster. A relatively blunt cold front appears in the simulated X-ray image because the contact discontinuity is perturbed by Rayleigh-Taylor instabilities. This can explain the ICM structure found in A168.

Motokazu Takizawa

2005-05-13

52

Concurrent variation between the East Asian subtropical jet and polar front jet during persistent snowstorm period in 2008 winter over southern China  

NASA Astrophysics Data System (ADS)

The concurrent variation features between the East Asian subtropical jet and polar front jet were investigated during persistent snowstorm period in 2007/2008 winter over southern China. The East Asian subtropical jet was divided into two parts: (1) the plateau jet, located along the southern side of the Tibetan Plateau, and (2) the ocean jet, situated at the southeastern Japan Island. The concurrent intensity variation among the polar front jet, plateau jet, and ocean jet and the associated atmospheric anomalous signals were examined. A possible mechanism for concurrent variation among the three jets was also investigated from a perspective of synoptic-scale transient eddy activities (STEA). The enhanced plateau jet was simultaneously correlated with the weakened polar front jet, while the variation of the ocean jet lagged the variation of the plateau jet (polar front jet) about 5 days. The concurrent variation between the plateau jet and the polar front jet acted as an important bridge that linked the snowstorm to the atmospheric anomalous signals associated with the cold and warm air activities. Due to the opposite trends of STEA variation over the southern and northern sides of the Tibetan Plateau, the plateau jet and the polar front jet exhibited a significant concurrent variation feature. The STEA anomalies over the plateau jet and polar front jet regions propagated downstream to the East Asian coast as a wave train along the southern and northern sides of the Tibetan Plateau, respectively, resulting in a 5 day lag variation relationship between the ocean jet and the plateau jet (polar front jet).

Liao, Zhijie; Zhang, Yaocun

2013-06-01

53

Cold fronts in the Colombian Caribbean Sea and their relationship to extreme wave events  

NASA Astrophysics Data System (ADS)

Extreme ocean waves in the Caribbean Sea are commonly related to the effects of storms and hurricanes during the months of June through November. The collapse of 200 m of the Puerto Colombia pier in March 2009 revealed the effects of meteorological phenomena other than storms and hurricanes that may be influencing the extreme wave regime in the Colombian Caribbean. The marked seasonality of these atmospheric fronts was established by analyzing the meteorological-marine reports of the Instituto de Hidrologa, Meteorologa y Estudios Ambientales of Colombia (IDEAM, based on its initials in Spanish) and the Centro de Investigacin en Oceanografa y Meteorologa of Colombia (CIOH, based on its initials in Spanish) during the last 16 yr. The highest number of cold fronts was observed during the months of January, February, and March, with 6 fronts occurring per year. An annual trend was observed and the highest number of fronts occurred in 2010 (20 in total); moreover, an annual strong relationship between the maximum average wave values and the cold fronts in the central zone of the Colombian Caribbean during the first three months of the year was established. In addition, the maximum values of the significant height produced by the passage of cold fronts during the last 16 yr were identified. Although the Colombian Caribbean has been affected by storms and hurricanes in the past, this research allows us to conclude that there is a strong relationship between cold fronts and the largest waves in the Colombian Caribbean during the last 16 yr, which have caused damage to coastal infrastructure. We verified that the passage of a cold front corresponded to the most significant extreme wave event of the last two decades in the Colombian Caribbean, which caused the structural collapse of the Puerto Colombia pier, located near the city of Barranquilla, between 5 and 10 March 2009. This information is invaluable when evaluating average and extreme wave regimes for the purpose of informing the design of structures in this region of the Caribbean.

Ortiz-Royero, J. C.; Otero, L. J.; Restrepo, J. C.; Ruiz, J.; Cadena, M.

2013-11-01

54

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

55

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

2002-09-20

56

Larger zooplankton in Danish lakes after cold winters: are winter fish kills of importance?  

Microsoft Academic Search

Winter fish kills can be intense under ice in shallow lakes, and have cascading effects on the food web and ultimately on\\u000a lake water clarity. In maritime Western Europe, winters are usually mild, but occasional colder periods may also have strong\\u000a effects on lake fish communities. Global warming may have disproportionate effects by delaying freezing and shortening the\\u000a period of

D. Balayla; T. L. Lauridsen; M. Sndergaard; E. Jeppesen

2010-01-01

57

Robust Arctic sea-ice influence on the frequent Eurasian cold winters in past decades  

NASA Astrophysics Data System (ADS)

Over the past decade, severe winters occurred frequently in mid-latitude Eurasia, despite increasing global- and annual-mean surface air temperatures. Observations suggest that these cold Eurasian winters could have been instigated by Arctic sea-ice decline, through excitation of circulation anomalies similar to the Arctic Oscillation. In climate simulations, however, a robust atmospheric response to sea-ice decline has not been found, perhaps owing to energetic internal fluctuations in the atmospheric circulation. Here we use a 100-member ensemble of simulations with an atmospheric general circulation model driven by observation-based sea-ice concentration anomalies to show that as a result of sea-ice reduction in the Barents-Kara Sea, the probability of severe winters has more than doubled in central Eurasia. In our simulations, the atmospheric response to sea-ice decline is approximately independent of the Arctic Oscillation. Both reanalysis data and our simulations suggest that sea-ice decline leads to more frequent Eurasian blocking situations, which in turn favour cold-air advection to Eurasia and hence severe winters. Based on a further analysis of simulations from 22 climate models we conclude that the sea-ice-driven cold winters are unlikely to dominate in a warming future climate, although uncertainty remains, due in part to an insufficient ensemble size.

Mori, Masato; Watanabe, Masahiro; Shiogama, Hideo; Inoue, Jun; Kimoto, Masahide

2014-12-01

58

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

PubMed Central

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

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

2013-01-01

59

Energy-saving Renovation Technology Studies of Existing Residential Building in the Hot Summer and Cold Winter Summer Zone  

E-print Network

and Cold Winter Summer Zone Meining Dong 1 Jiahua Li 2 (Southwest University of Science and Technology,621010) dong_meining@tom.com Abstract: The hot summer and cold winter zones are some of the key national construction energy..., above all else, the temperature always falls fiercely in the whole area in the winter following gale and 1.Meining DONG Female 1981.3 Graduate student of Civil engineering and Architecture College of Southwest University of Science...

Dong, M.; Li, J.

2006-01-01

60

EVALUATON OF MID-WINTER COLD HARDINESS AMONG 25 RABBITEYE BLUEBERRY (VACCINIUM ASHEI READE) CULTIVARS  

Technology Transfer Automated Retrieval System (TEKTRAN)

The mid-winter cold hardiness of 25 rabbiteye (V. ashei) blueberry cultivars was assayed across two years using a shoot freezing assay. LT50 values (i.e. temperature at which 50% of buds are damaged) for the cultivars ranged from -24.9 C for Pearl River (a 50% V. ashei derivative) to -13.7 C for...

61

Orographic effects during winter cold air outbreaks over the Sea of Japan (East Sea): Results  

E-print Network

Orographic effects during winter cold air outbreaks over the Sea of Japan (East Sea): Results from over the Sea of Japan (East Sea) [JES] has been the object of a number of investigations (Dorman et al 27599 Abstract We study the effects of the coastal topography on the western shore of the Sea of Japan

Scotti, Alberto

62

The climatology of East Asian winter monsoon and cold surges from 1979--1995 NCEP/NCAR reanalyses  

SciTech Connect

The East Asian winter monsoon, which is associated with the Siberian high and active cold surges, is one of the most energetic monsoon circulation systems. The dramatic shift of northeasterlies and the outbreak of cold surges dominate the winter weather and local climate in the East Asian region, and may exert a strong impact on the extratropical and tropical planetary-scale circulations and influence the SSTs in the tropical western Pacific. General characteristics of the winter monsoon and cold surges and their possible link with tropical disturbances are revealed in many observational studies. Little attention has been given to the climatological aspects of the winter monsoon and cold surges. The purpose of this study is to compile and document the East Asian mean winter circulation, and present the climatology of cold surges and the Siberian high based on the 1979--1995 NCEP/NCAR reanalyses. Of particular interest is the interannual variation of winter monsoon circulation and cold surge events. Given that the cold surge activity and the Indonesian convection are much reduced during the 1982--83 period, one of the goals is to determine whether there exists a statistically significant relationship between ENSO and the interannual variation of winter monsoon and cold surges.

Yi Zhang; Sperber, K.; Boyle, J.

1996-04-01

63

Summer and winter drought in a cold desert ecosystem (Colorado Plateau) part II: effects on plant carbon assimilation and growth  

Microsoft Academic Search

We investigated the effects of winter and summer drought on a shrub\\/grass community of the Colorado Plateau in western North America, a winter-cold, summer-hot desert that receives both winter and summer precipitation. Summer, winter and yearlong drought treatments were imposed for 2 consecutive years using rainout shelters. We chose three perennial species for this study, representing different rooting patterns and

S. Schwinning; B. I. Starr; J. R. Ehleringer

2005-01-01

64

Merging Cold Fronts in the Galaxy Pair NGC 7619 and NGC 7626  

NASA Astrophysics Data System (ADS)

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 ~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 ~1190 km s-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.

2009-05-01

65

On the width of cold fronts in clusters of galaxies due to conduction  

E-print Network

We consider the impact of thermal conduction in clusters of galaxies on the (unmagnetized) interface between a cold gaseous cloud and a hotter gas flowing over the cloud (the so-called cold front). We argue that near the stagnation point of the flow conduction creates a spatially extended layer of constant thickness $\\Delta$, where $\\Delta$ is of order $\\sim\\sqrt{kR/U}$, and $R$ is the curvature radius of the cloud, $U$ is the velocity of the flow at infinity, and $k$ is the conductivity of the gas. For typical parameters of the observed fronts, one finds $\\Delta \\ll R$. The formation time of such a layer is $\\sim R/U$. Once the layer is formed, its thickness only slowly varies with time and the quasi-steady layer may persist for many characteristic time scales. Based on these simple arguments one can use the observed width of the cold fronts in galaxy clusters to constrain the effective thermal conductivity of the intra-cluster medium.

F. Xiang; E. Churazov; K. Dolag; V. Springel; A. Vikhlinin

2007-06-01

66

A novel plant defensin-like gene of winter wheat is specifically induced during cold acclimation.  

PubMed

A novel cDNA clone, Tad1, was isolated from crown tissue of winter wheat after differential screening of cold acclimation-induced genes. The Tad1 cDNA encoded a 23kDa polypeptide with a potential N-terminal signal sequence. The putative mature sequence showed striking similarity to plant defensins or gamma-thionins, representing low molecular size antipathogenic polypeptides. High levels of Tad1 mRNA accumulation occurred within one day of cold acclimation in crown tissue and the level was maintained throughout 14 days of cold acclimation. Similar rapid induction was observed in young seedlings treated with low temperature but not with exogenous abscisic acid. In contrast to defensins from other plant species, neither salicylic acid nor methyl jasmonate induced expression of Tad1. The recombinant mature form of TAD1 polypeptide inhibited the growth of the phytopathogenic bacteria, Pseudomonas cichorii; however, no antifreeze activity was detected. Collectively, these data suggested that Tad1 is induced in cold-acclimated winter wheat independent of major defense signaling(s) and is involved in low temperature-induced resistance to pathogens during winter hardening. PMID:12379218

Koike, Michiya; Okamoto, Takashi; Tsuda, Sakae; Imai, Ryozo

2002-10-18

67

Variability in cold front activities modulating cool-season evaporation from a southern inland water in the USA  

NASA Astrophysics Data System (ADS)

Understanding seasonal variations in the evaporation of inland waters (e.g., lakes and reservoirs) is important for water resource management as well as the prediction of the hydrological cycles in response to climate change. We analyzed eddy covariance-based evaporation measurements from the Ross Barnett Reservoir (3226'N, 9002'W which is always ice-free) in central Mississippi during the cool months (i.e., September-March) of 2007 and 2008, and found that the variability in cold front activities (i.e., passages of cold fronts and cold/dry air masses behind cold fronts) played an important role in modulating the exchange of sensible (H) and latent (?E) heat fluxes. Our analysis showed that 2007's warmer cool season had smaller mean H and ?E than 2008's cooler cool season. This implies that the warmer cool season did not accelerate evaporation and heat exchange between the water surface and the atmosphere. Instead, more frequent cold fronts and longer periods of cold/dry air masses behind the cold fronts in 2008 resulted in overall larger H and ?E as compared with 2007, this primarily taking the form of sporadic short-term rapid 'pulses' of H and ?E losses from the water's surface. These results suggest that future climate-induced changes in frequency of cold fronts and the meteorological properties of the air masses behind cold fronts (e.g., wind speeds, temperature, and humidity), rather than other factors of climate change, would produce significant variations in the water surface's energy fluxes and subsequent evaporation rates.

Liu, Heping; Blanken, Peter D.; Weidinger, Tamas; Nordbo, Annika; Vesala, Timo

2011-04-01

68

Heat production in cold and long scotophase acclimated and winter acclimatized rodents  

NASA Astrophysics Data System (ADS)

Heat production by means of oxygen consumptionVo2 (at Ta = 6 C, 25 C, 30 C, and 32 C) and non-shivering thermogenesis (NST) were studied in individuals of a diurnal rodent ( Rhabdomys pumilio) and a nocturnal rodent ( Praomys natalensis). The studied mice were acclimated to cold at Ta=8C with a photoperiod of LD 12:12. On the otherhand specimens of these two species were acclimated at Ta=25C with a long scotophase LD8:16. The results were compared with a control group (Ta=25 C, LD 12:12) and winter acclimatized individuals of both species.Vo2 in cold acclimated mice of both species was significantly increased when compared to the control group and was even higher than the winter acclimatized group when measured below the lower critical temperature. Long scotophase acclimated mice of both species also increased their oxygen consumption significantly when compared to the control group. NST was significantly increased in long scotophase acclimated mice from both species when compared to the control group. The results of this study indicate that the effects of acclimation to long scotophase are similar to those of cold acclimation. As changes in photoperiod are regular, it may be assumed that heat production mechanisms in acclimatization to winter will respond to changes in photoperiodicity.

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

1980-09-01

69

Characterization and expression patterns of five Winter Rye ??-1,3-endoglucanases and their role in cold acclimation.  

E-print Network

??Winter rye produces ice-modifying antifreeze proteins upon cold treatment. Two of these antifreeze proteins are members of the large, highly conserved, ??-1,3-endoglucanase family. This project (more)

McCabe, Shauna

2007-01-01

70

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 Irelands 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

71

Cold-induced bradycardia in man during sleep in Arctic winter nights  

NASA Astrophysics Data System (ADS)

Two young male Caucasians volunteered for a study on the effects of cold exposure during night sleep in winter in the Arctic. The 14-day experiment was divided in three consecutive periods, baseline (2 nights), cold exposure (10 night) and recovery (2 nights). Both baseline and recovery data were obtained in neutral thermal conditions in a laboratory. The subjects slept in a sleeping bag under an unheated tent during the cold exposure. Apart from polysomnographic and body temperature recordings, electrocardiograms were taken through a telemetric system for safety purposes. Heart rates were noted at 5-min intervals and averaged hourly. In both environmental conditions, heart rate decreased within the first two hours of sleep. Comparison of the data obtained during cold exposure vs. thermal neutrality revealed lower values of heart rate in the cold, while body temperatures remained within normal range. This cold-induced bradycardia supervening during night sleep is discussed in terms of the occurrence of a vagal reflex preventing central blood pressure to rise.

Buguet, A. G. C.

1987-03-01

72

Changes in winter cold surges over Southeast China: 1961 to 2012  

NASA Astrophysics Data System (ADS)

The present study investigates the overall changes in occurrences of winter cold surges over Southeast China for the period 1961-2012, using instrumental observations, reanalysis and model simulation datasets. Based on objectively defined criteria, cold surges were classified into 3 types according to their dynamical origin as inferred from daily evolution patterns of surface pressure systems with a focus on the Siberian High (SH): type A with an amplification of a quasi-stationary SH associated with high-pressure anomalies over the Ural mountains, type B with a developing SH associated with fast traveling upper-level waves, and type C with a high-pressure originated in the Arctic. Examination of the long-term change in cold surge occurrences shows different interdecadal variations among the 3 types. During 1961-2012, type A events (37.8%) decreased, while type B events, accounting for the majority (52.5%) of total winter cold surges, increased slightly. The contribution by type C to the total occurrence of the cold surges was small (8.8%) compared to that of A and B, but it became more frequent in the latest decade, related to the tendency of the Arctic Oscillation (AO) being more in its negative phase. Overall, we found slightly increased occurrences of cold surges over Southeast China since the early 1980s, despite the weakened SH intensity and warmer mean temperature compared to previous decades. The climate model projections of the phase 5 of the Coupled Model Intercomparison Project (CMIP5) suggests similar trend in the late 21st century under warmer climate.

Ou, Tinghai; Chen, Deliang; Jeong, Jee-Hoon; Linderholm, Hans W.; Zhou, Tianjun

2015-01-01

73

A Spontaneous Generation of the Magnetic Field and Suppression of the Heat Conduction in Cold Fronts  

E-print Network

We have determined the physical mechanism responsible for the plasma instabilities, which was first found by Ramani and Laval (1978), associated with anisotropic velocity distributions induced by the temperature gradient in which there are growing low frequency transverse magnetic waves, even in the absence of background magnetic fields. We have shown that the physical mechanism responsible for the growth of one of the modes is identical to the Weibel instability. The nonlinear saturation level of the instability is also provided by considering the wave-particle interactions. The non-linear evolutions of the magnetic fields after the saturation are speculated. The results are applied to the cold fronts which is one of the newly discovered structures in clusters of galaxies by the Chandra X-ray observatory. We predict the existence of the magnetic field of $\\sim 10\\mu$G tangential to the surface over the entire region of the cold front surface and that the heat conduction is significantly suppressed by the trapping of the electrons by the generated magnetic fields. The instability may provide a new possibility on the origin of cosmic magnetic field.

Nobuhiro Okabe; Makoto Hattori

2003-09-19

74

Abell 1201: The anatomy of a cold front cluster from combined optical and X-ray data  

E-print Network

We present a combined X-ray and optical analysis of the cold front cluster Abell 1201 using archival Chandra, data and multi-object spectroscopy taken with the 3.9m Anglo Australian and 6.5m Multiple Mirror Telescopes. This paper represents the first in a series presenting a study of a sample of cold front clusters selected from the Chandra, archives with the aim of relating cold fronts to merger activity, understanding the dynamics of mergers and their effect on the cluster constituents. The Chandra X-ray imagery of Abell 1201 reveals two conspicuous surface brightness discontinuities, which are shown to be cold fronts, and a remnant core structure. Temperature maps reveal a complex multi-phase temperature structure with regions of hot gas interspersed with fingers of cold gas. Our optical analysis is based on a sample of 321 confirmed members, whose mean redshift is z=0.1673 +/- 0.0002 and velocity dispersion is 778 +/- 36 km/s. We search for dynamical substructure and find clear evidence for multiple localized velocity substructures coincident with over-densities in the galaxy surface density. Most notably, we find structure coincident with the remnant X-ray core. Despite the clear evidence for dynamical activity, we find the peculiar velocity distribution does not deviate significantly from Gaussian. We apply two-body dynamical analyses in order to assess which of the substructures are bound, and thus dynamically important in terms of the cluster merger history. We propose that the cold fronts in Abell 1201 are a consequence of its merger with a smaller subunit, which has induced gas motions that gave rise to `sloshing' cold fronts. Abell 1201 illustrates the value of combining multi-wavelength data and multiple substructure detection techniques when attempting to ascertain the dynamical state of a cluster.

Matt S. Owers; Paul E. J. Nulsen; Warrick J. Couch; Maxim Markevitch; Gregory B. Poole

2008-10-25

75

Dynamics and ecological consequences of avian influenza virus infection in greater white-fronted geese in their winter staging areas.  

PubMed

Recent outbreaks of highly pathogenic avian influenza (HPAI) in poultry have raised interest in the interplay between avian influenza (AI) viruses and their wild hosts. Studies linking virus ecology to host ecology are still scarce, particularly for non-duck species. Here, we link capture-resighting data of greater white-fronted geese Anser albifrons albifrons with the AI virus infection data collected during capture in The Netherlands in four consecutive winters. We ask what factors are related to AI virus prevalence and whether there are ecological consequences associated with AI virus infection in staging white-fronted geese. Mean seasonal (low pathogenic) AI virus prevalence ranged between 2.5 and 10.7 per cent, among the highest reported values for non-duck species, and occurred in distinct peaks with near-zero prevalence before and after. Throat samples had a 2.4 times higher detection frequency than cloacal samples. AI virus infection was significantly related to age and body mass in some but not other winters. AI virus infection was not related to resighting probability, nor to maximum distance travelled, which was at least 191 km during the short infectious lifespan of an AI virus. Our results suggest that transmission via the respiratory route could be an important transmission route of AI virus in this species. Near-zero prevalence upon arrival on their wintering grounds, in combination with the epidemic nature of AI virus infections in white-fronted geese, suggests that white-fronted geese are not likely to disperse Asian AI viruses from their Siberian breeding grounds to their European wintering areas. PMID:20200028

Kleijn, D; Munster, V J; Ebbinge, B S; Jonkers, D A; Mskens, G J D M; Van Randen, Y; Fouchier, R A M

2010-07-01

76

Spatial Use by Wintering Greater White-Fronted Geese Relative to a Decade of Habitat Change in California's  

Microsoft Academic Search

We investigated the effect of recent habitat changes in California's Central Valley on wintering Pacific greater white-fronted geese (Anser albifrons frontalis) by comparing roost-to-feed distances, distributions, population range sizes, and habitat use during 1987-1990 and 1998- 2000. These habitat changes included wetland restoration and agricultural land enhancement due to the 1990 implementation of the Central Valley Joint Venture, increased land

JOSHUA T. ACKERMAN; JOHN Y. TAKEKAWA; DENNIS L. ORTHMEYER; JOSEPH P. FLESKES; JULIE L. YEE; KAMMIE L. KRUSE

77

Spatial Use by Wintering Greater White-Fronted Geese Relative to a Decade of Habitat Change in California's Central Valley  

Microsoft Academic Search

Abstract We investigated,the effect of recent,habitat changes,in Californias Central Valley on,wintering,Pacific greater,white-fronted,geese,(Anser albifrons frontalis) by comparing roost-to-feed distances, distributions, population range sizes, and habitat use during 19871990 and 1998 2000. These habitat changes included wetland restoration and agricultural land enhancement,due to the 1990 implementation of the Central Valley Joint Venture, increased land area used for rice (Oryza sativa) production, and

JOSHUA T. ACKERMAN; JOHN Y. TAKEKAWA; DENNIS L. ORTHMEYER; JOSEPH P. FLESKES; JULIE L. YEE; KAMMIE L. KRUSE

2006-01-01

78

Dynamics and ecological consequences of avian influenza virus infection in greater white-fronted geese in their winter staging areas  

PubMed Central

Recent outbreaks of highly pathogenic avian influenza (HPAI) in poultry have raised interest in the interplay between avian influenza (AI) viruses and their wild hosts. Studies linking virus ecology to host ecology are still scarce, particularly for non-duck species. Here, we link captureresighting data of greater white-fronted geese Anser albifrons albifrons with the AI virus infection data collected during capture in The Netherlands in four consecutive winters. We ask what factors are related to AI virus prevalence and whether there are ecological consequences associated with AI virus infection in staging white-fronted geese. Mean seasonal (low pathogenic) AI virus prevalence ranged between 2.5 and 10.7 per cent, among the highest reported values for non-duck species, and occurred in distinct peaks with near-zero prevalence before and after. Throat samples had a 2.4 times higher detection frequency than cloacal samples. AI virus infection was significantly related to age and body mass in some but not other winters. AI virus infection was not related to resighting probability, nor to maximum distance travelled, which was at least 191 km during the short infectious lifespan of an AI virus. Our results suggest that transmission via the respiratory route could be an important transmission route of AI virus in this species. Near-zero prevalence upon arrival on their wintering grounds, in combination with the epidemic nature of AI virus infections in white-fronted geese, suggests that white-fronted geese are not likely to disperse Asian AI viruses from their Siberian breeding grounds to their European wintering areas. PMID:20200028

Kleijn, D.; Munster, V. J.; Ebbinge, B. S.; Jonkers, D. A.; Mskens, G. J. D. M.; Van Randen, Y.; Fouchier, R. A. M.

2010-01-01

79

Characteristics of atmospheric circulation associated with cold surge occurrences in East Asia: A case study during 2005\\/06 winter  

Microsoft Academic Search

The characteristics of the upper-level circulation and thermodynamical properties for the period when two distinct cold surges\\u000a broke out over East Asia during the 2005\\/06 winter are investigated. From early December 2005 to early January 2006, exceptionally\\u000a cold weather lasted for approximately one month due to two successive cold surges that took place on 2 December 2005 and 2\\u000a January

Tae-Won Park; Jee-Hoon Jeong; Chang-Hoi Ho; Seong-Joong Kim

2008-01-01

80

Winter variability of aeolian sediment transport threshold on a cold-climate dune  

NASA Astrophysics Data System (ADS)

Changes in surface conditions on cold-climate aeolian dunes are pronounced; during winter dunes are wet, snow covered, and/or frozen for extended periods of time. It is unknown how the critical wind speed for sediment transport (threshold) varies and how threshold may influence sediment transport predictions. Although the impact of surface conditions on threshold has been examined in synthetic experiments (wind tunnels), complicated feedbacks between threshold, sand transport, and surface conditions that occur in natural environments suggest that a ground-based empirical approach may provide enhanced insight. In this study we investigate threshold variability for 73 days during fall-winter-spring surface conditions from 18 November 2008 to 30 May 2009 in the Bigstick Sand Hills of Saskatchewan, Canada. Simultaneous measurements of threshold and atmospheric variables (air temperature, relative humidity, solar radiation, wind speed and direction) were used to examine the extent to which surface erodibility was regulated by meteorology. Time-lapse images of the surface from a co-located camera were used for quality control and interpreting changes in the surface affecting threshold. Results reveal that threshold varied throughout the deployment (25-75% quartiles: 6.92-8.28 m s- 1; mean: 7.79 m s- 1). Threshold variability was especially evident at two scales: (i) event timescale and (ii) seasonal timescale. Event-scale variability peaked during mid-winter; in one event the threshold varied by 6 m s- 1 in 2 h with freezing and re-freezing of the surface and relatively constant atmospheric conditions. The causes of event-scale variability are complex though qualitatively related to changes of wind direction, antecedent meteorological conditions, and vertical variations of grain-scale bonding agents such as pore ice and moisture. Seasonal-scale changes manifested as an increase in threshold during fall, peaking in mid-winter, and decreasing in spring. Increased threshold in mid-winter was linked to lower insolation and air temperature, suggesting low erodibility due to the presence of pore ice. Correlation coefficients of threshold versus atmospheric variables yielded relatively weak correlations (air temperature: r = - 0.322; relative humidity: r = 0.388; solar radiation: r = - 0.309) that also varied according to wind direction, suggesting that the link between atmospheric conditions and surface erodibility on cold-climate dunes is complex. This contrasts with results from field-based studies in warmer climates and controlled wind tunnel experiments, which show a more direct link between atmospheric variables (temperature and humidity) and surface erodibility. Nevertheless, our results do show a seasonal pattern of threshold that could be important for modeling cold-climate aeolian sediment transport.

Barchyn, Thomas E.; Hugenholtz, Chris H.

2012-12-01

81

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

PubMed Central

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.

2013-01-01

82

Research aircraft observations of the mesoscale and microscale structure of a cold front over the eastern Pacific Ocean  

NASA Technical Reports Server (NTRS)

The structure of an oceanic cold front is described on the basis of research aircraft observations taken during the Ocean Storms field experiment. Synoptic and mesoscale analyses compare the structure of an upper-level jet-front system observed slightly downstream from the wind speed maximum to its structure in the upstream entrance region. Stratospheric potential vorticity and ozone were found within the frontal zone down to about 800 mb. Microscale analyses of the front near the sea surface were carried out for a portion of the front having the signature of a 'rope' cloud in satellite imagery. A narrow (less than 1 km) zone of upward motion (about 4 m/s) and of horizontal shear (about 0.01/s) characterized the front near the surface. Significant alongfront variability was found, including lateral displacements in the frontal zone where there were weaker updrafts.

Bond, Nicholas A.; Shapiro, M. A.

1991-01-01

83

Characterization and effects of cold fronts in the Colombian Caribbean Coast and their relationship to extreme wave events  

NASA Astrophysics Data System (ADS)

Extreme ocean waves in the Caribbean Sea are commonly related to the effects of storms and hurricanes during the months of June through November. The collapse of 200 m of the Puerto Colombia pier in March 2009 revealed the effects of meteorological phenomena other than storms and hurricanes that may be influencing the extreme wave regime in the Colombian Caribbean. The marked seasonality of these atmospheric fronts was established by analyzing the meteorological-marine reports of Instituto de Hidrologa, Meteorologa y Estudios Ambientales of Colombia (IDEAM, based on its initials in Spanish) and Centro de Investigacin en Oceanografa y Meteorologa of Colombia (CIOH, based on its initials in Spanish). The highest occurrences were observed during the months of January, February, and March, with 6 fronts occurring per year. An annual trend was not observed, although the highest number of fronts occurred in 2010 (20 in total). An annual strong relationship between the maximum average wave values and the cold fronts, in the central zone of the Colombian Caribbean during the first three months of the year was established. In addition, the maximum values of the significant height produced by the passage of cold fronts during the last 16 yr were identified. Although the Colombian Caribbean has been affected by storms and hurricanes in the past, this research allows us to conclude that, there is a strong relationship between cold fronts and the largest waves in the Colombian Caribbean during the last 16 yr, which have caused damage to coastal infrastructure. We verified that the passage of a cold front corresponded to the most significant extreme wave event of the last two decades in the Colombian Caribbean, which caused the structural collapse of the Puerto Colombia pier, located near the city of Barranquilla, between 5 and 10 March 2009. This information is invaluable when evaluating average and extreme wave regimes for the purpose of informing the design of structures in this region of the Caribbean.

Ortiz-Royero, J. C.; Otero, L. J.; Restrepo, J. C.; Ruiz, J.; Cadena, M.

2013-07-01

84

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

E-print Network

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

85

Summer and winter drought in a cold desert ecosystem (Colorado Plateau) part I: effects on soil water and plant water uptake  

Microsoft Academic Search

We investigated the effects of winter and summer drought on plants of the Colorado Plateau in western North America. This winter-cold, summer-hot desert region receives both winter and summer precipitation. Droughts were imposed for two consecutive years using rainout shelters. Here, we examine drought effects on the hydrologic interactions between plants and soil. We chose three perennial species for this

S. Schwinning; B. I. Starr; J. R. Ehleringer

2005-01-01

86

Plant development affects the cold-induced expression of plant defence-related transcripts in winter wheat  

Microsoft Academic Search

In winter cereals, low temperature hardening, plant age and genotype are known to influence the expression of resistance to snow mould diseases. A study was undertaken to determine the effects of genotype, plant age and duration of cold hardening on the temporal expression of the PR-protein and other defence-related protein transcripts under controlled environment conditions, and in the field during

D. A Gaudet; A Laroche; M Frick; R Huel; B Puchalski

2003-01-01

87

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

88

Geographic variation in Bar-headed Geese Anser indicus: Connectivity of wintering areas 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. ?? Wildfowl & Wetlands Trust.

Takekawa, J.Y.; Heath, S.R.; Douglas, D.C.; Perry, W.M.; Javed, S.; Newman, S.H.; Suwal, R.N.; Rahmani, A.R.; Choudhury, B.C.; Prosser, D.J.; Yan, B.; Hou, Y.; Batbayar, N.; Natsagdorj, T.; Bishop, C.M.; Butler, P.J.; Frappell, P.B.; Milsom, W.K.; Scott, G.R.; Hawkes, L.A.; Wikelski, M.

2009-01-01

89

MAGNETOHYDRODYNAMIC SIMULATIONS OF THE FORMATION OF COLD FRONTS IN CLUSTERS OF GALAXIES: EFFECTS OF ANISOTROPIC VISCOSITY  

SciTech Connect

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 {beta}{sup -1} {approx} 0.01 in models with viscosity, whereas they are amplified up to {beta}{sup -1} {approx} 0.1 in models without viscosity, where {beta} is the ratio of gas pressure to magnetic pressure.

Suzuki, Kentaro; Ogawa, Takayuki; Matsumoto, Yosuke; Matsumoto, Ryoji, E-mail: suzukikn@astro.s.chiba-u.ac.jp, E-mail: ogawa@astro.s.chiba-u.ac.jp, E-mail: ymatumot@astro.s.chiba-u.ac.jp, E-mail: matumoto@astro.s.chiba-u.ac.jp [Department of Physics, Graduate School of Science, Chiba University, Inage-ku, Chiba 263-8522 (Japan)

2013-05-10

90

SLOSHING COLD FRONTS IN GALAXY GROUPS AND THEIR PERTURBING DISK GALAXIES: AN X-RAY, OPTICAL, AND RADIO CASE STUDY  

SciTech Connect

We present a combined X-ray, optical, and radio analysis of the galaxy group IC 1860 using the currently available Chandra and XMM data, multi-object spectroscopy data from the literature, and Giant Metrewave Radio Telescope (GMRT) data. The Chandra and XMM imaging and spectroscopy reveal two surface brightness discontinuities at 45 and 76 kpc shown to be consistent with a pair of cold fronts. These features are interpreted as due to sloshing of the central gas induced by an off-axis minor merger with a perturber. This scenario is further supported by the presence of a peculiar velocity of the central galaxy IC 1860 and the identification of a possible perturber in the optically disturbed spiral galaxy IC 1859. The identification of the perturber is consistent with the comparison with numerical simulations of sloshing. The GMRT observation at 325 MHz shows faint, extended radio emission contained within the inner cold front, as seen in some galaxy clusters hosting diffuse radio mini-halos. However, unlike mini-halos, no particle reacceleration is needed to explain the extended radio emission, which is consistent with aged radio plasma redistributed by the sloshing. There is a strong analogy between the X-ray and optical phenomenology of the IC 1860 group and that of two other groups, NGC 5044 and NGC 5846, showing cold fronts. The evidence presented in this paper is among the strongest supporting the currently favored model of cold-front formation in relaxed objects and establishes the group scale as a chief environment for studying this phenomenon.

Gastaldello, Fabio; Di Gesu, Laura; Ghizzardi, Simona; Rossetti, Mariachiara [IASF-Milano, INAF, via Bassini 15, I-20133 Milan (Italy); Giacintucci, Simona [Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States); Girardi, Marisa [Dipartimento di Fisica, Universita degli Studi di Trieste, Sezione di Astronomia, via Tiepolo 11, I-34133 Trieste (Italy); Roediger, Elke [Jacobs University Bremen, P.O. Box 750 561, D-28725 Bremen (Germany); Brighenti, Fabrizio [Dipartimento di Astronomia, Universita di Bologna, via Ranzani 1, I-40127 Bologna (Italy); Buote, David A.; Humphrey, Philip J. [Department of Physics and Astronomy, University of California at Irvine, 4129 Frederick Reines Hall, Irvine, CA 92697-4575 (United States); Eckert, Dominique [ISDC Data Centre for Astrophysics, Geneva Observatory, ch. d'Ecogia, 16, CH-1290 Versoix (Switzerland); Ettori, Stefano [INAF, Osservatorio Astronomico di Bologna, via Ranzani 1, I-40127 Bologna (Italy); Mathews, William G. [UCO/Lick Observatory, University of California at Santa Cruz, 1156 High Street, Santa Cruz, CA 95064 (United States)

2013-06-10

91

WITHIN AND AMONG-YEAR EFFECTS OF COLD FRONTS ON MIGRATING RAPTORS AT HAWK MOUNTAIN, PENNSYLVANIA, 1934-1991  

Microsoft Academic Search

ABsTRAcr.--Cold-front passage has long been associated with south-bound raptor migration in northeastern North America. We used Hawk Mountain Sanctuary's 55-year database to calculate abundance indices of 14 raptor species at the site. These indices, together with data taken from coincidental U.S. Department of Commerce daily weather maps, were used to investigate the extent to which raptor migration at Hawk Mountain

PAUL E. ALLEN; LAURIE J. GOODRICH; KEITH L. BILDSTEIN

92

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

93

CSCI 3060U/ENGR 3980U -Winter 2013 Course Project Assignment #1 -Front End Requirements  

E-print Network

and in true XP fashion represent those requirements as a set of requirements tests. Create and organize a complete set of requirements tests for the Front End of the Ticket Selling Service, to test for every required behaviour. Do not write any programs yet. Each test should be a complete test session input stream

Bradbury, Jeremy S.

94

Fronts and orography  

Microsoft Academic Search

Summary Theoretical work on the impact of orography on cold fronts is reviewed and related to observations. This paper contains the following sections:1.Introduction2.Passive scalar fronts3.Shallow water fronts4.Fronts in deformation flows5.Orographic jets6.Cold-air damming7.Fhn and fronts8.Fronts in valleys9.Cold surges10.Lee cyclogenesis11.Orographic rain and fronts12.Pressure drag13.Numerical simulations14.Analysis

J. Egger; K. P. Hoinka

1992-01-01

95

A model study of the effects of river discharges and interannual variation of winds on the plume front in winter in Pearl River Estuary  

NASA Astrophysics Data System (ADS)

A three-dimensional numerical model, Estuarine, Coastal and Ocean Modeling System with Sediments (ECOMSED), is employed to study the mechanism of plume front in the Pearl River Estuary (PRE) in detail. The model is forced by winds, tides and river discharges. The modeled results of tidal elevation, current velocity and salinity are in reasonable agreement with observational data in the PRE. By analyzing momentum and saltwater transport balance equations, it is found that the wind stress term, the pressure gradient term and the local time derivative term of velocity are dominant in the momentum equation, while the local time derivative term, the horizontal advective term and the vertical mixing term of salinity are dominant in the salinity transport equation. The residual current at surface along the plume front is seaward and stronger, whilst that in the bottom layer is mainly landward. A series of sensitive experiments is also run to examine the responses of plume front to changes of river discharges at different inlets in Lingdingyang Bay and interannual variation of northeast winds in winter. The location of plume front responds differently to the change of river discharge at different inlets. An increase in the river discharge at Dahu inlet seems to affect the location of plume front most among the four river inlets, it makes the plume front move eastward and southward wholly; the variation of river discharge at Nansha or Fengmamiao inlet on the location of plume front is more local and weaker; whilst the variation of river discharge at Hengmen inlet has little effect on the plume front. The location of plume front also changes in response to the interannual variation of northeast winds in winter, the stronger or the more eastward the winds are, the more westward the plume front moves, and only in the northern PRE, the response of plume front to the variation of wind speeds is largely different from that to the variation of wind directions.

Zheng, Shu; Guan, Weibing; Cai, Shuqun; Wei, Xing; Huang, Daji

2014-02-01

96

A cold inducible multidomain cystatin from winter wheat inhibits growth of the snow mold fungus, Microdochium nivale  

Microsoft Academic Search

A novel cold-induced cystatin cDNA clone (TaMDC1) was isolated from cold acclimated winter wheat crown tissue by using a macroarray-based differential screening method. The deduced amino acid sequence consisted of a putative N-terminal secretory signal peptide of 37 amino acids and a mature protein (mTaMDC1) with a molecular mass of 23kDa. The mTaMDC1 had a highly conserved N-terminal cystatin domain

Petya Koeva Christova; Nikolai Kirilov Christov; Ryozo Imai

2006-01-01

97

Interactions between cold hardening and Microdochium nivaleinfection on expression of pathogenesis-related genes in winter wheat  

Microsoft Academic Search

Cold hardening induces snow mould resistance in cereals and grasses. The mechanism for this induced resistance is not fully understood. The accumulation of transcripts encoding sucrose synthase and the pathogenesis-related proteins (PR-proteins) chitinase, ?-1,3-glucanase, peroxidase and PR-1a were studied in hardened and non-hardened winter wheat at several time points after inoculation with the snow mouldMicrodochium nivale.Sucrose synthase was induced by

. Ergon; S. S. Klemsdal; A. M. Tronsmo

1998-01-01

98

A cold inducible multidomain cystatin from winter wheat inhibits growth of the snow mold fungus, Microdochium nivale.  

PubMed

A novel cold-induced cystatin cDNA clone (TaMDC1) was isolated from cold acclimated winter wheat crown tissue by using a macroarray-based differential screening method. The deduced amino acid sequence consisted of a putative N-terminal secretory signal peptide of 37 amino acids and a mature protein (mTaMDC1) with a molecular mass of 23 kDa. The mTaMDC1 had a highly conserved N-terminal cystatin domain and a long C-terminal extension containing a second region, which exhibited partial similarity to the cystatin domain. The recombinant mTaMDC1 was purified from Escherichia coli and its cysteine proteinase inhibitory activity against papain was analyzed. The calculated Ki value of 5.8 x 10(-7) M is comparable to those reported for other phytocystatins. Northern and western blot analyses showed elevated expression of TaMDC1 mRNA and protein during cold acclimation of wheat. In addition to cold, accumulation of the TaMDC1 message was induced by other abiotic stresses including drought, salt and ABA treatment. Investigation of in vitro antifungal activity of mTaMDC1 showed strong inhibition on the mycelium growth of the snow mold fungus Microdochium nivale. Hyphae growth was totally inhibited in the presence of 50 mug/ml mTaMDC1 and morphological changes such as swelling, fragmentation and sporulation of the fungus were observed. The mechanisms of the in vitro antifungal effects and the possible involvement of TaMDC1 in cold induced snow mold resistance of winter wheat are discussed. PMID:16320069

Christova, Petya Koeva; Christov, Nikolai Kirilov; Imai, Ryozo

2006-05-01

99

A Wild Ride for Abell 2443: A High Impact Velocity Merger with a Shock, Cold Front, and Relic  

NASA Astrophysics Data System (ADS)

The dynamical state of galaxy clusters is revealed through X-ray features such as shocks and cold-fronts as well as radio features such as diffuse synchrotron emission. Abell 2443 is host to a shock edge, cold-front contact discontinuity, and ultra-steep spectrum radio relic. These features all point toward a cluster undergoing a significant merger but our recent deep Chandra data have revealed a more complex picture. We see a double-tailed X-ray tail reminiscent of that in 'El Gordo'. This structure appears to trace the trajectory of the merging subcomponent and suggests that it is highly inclined with respect to the line of sight. Separating the X-ray emission of the merging tailed component from that of its surroundings (the main cluster) suggests, through spectral fits, that the two components of Abell 2443 have a relative line of sight velocity difference of over 3000 km/s. Ahead of the merging component is where the ultra-steep spectrum radio relic appears co-spatial with the outgoing shock edge from this violent collision.

Clarke, T.; Mroczkowski, T.; Randall, S.; Sarazin, C.; Intema, H.; Giacintucci, S.; Blanton, E.

2014-07-01

100

'Only old ladies would do that': age stigma and older people's strategies for dealing with winter cold.  

PubMed

Concerns over the welfare of older people in winter have led to interventions and advice campaigns meant to improve their ability to keep warm, but older people themselves are not always willing to follow these recommendations. In this paper we draw on an in-depth study that followed twenty one older person households in the UK over a cold winter and examined various aspects of their routine warmth-related practices at home and the rationales underpinning them. We find that although certain aspects of ageing did lead participants to feel they had changing warmth needs, their practices were also shaped by the problematic task of negotiating identities in the context of a wider stigmatisation of older age and an evident resistance to ageist discourses. After outlining the various ways in which this was manifest in our study, we conclude by drawing out the implications for future policy and research. PMID:21606000

Day, Rosie; Hitchings, Russell

2011-07-01

101

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

102

Ossification of ungular cartilages in front feet of cold-blooded trotters - a clinical radiographic evaluation of development over time.  

PubMed

BackgroundIt has not yet been shown that ossification of ungular cartilages (OUC) is a pathological condition. Beside heredity, factors such as sex, age, repeated concussion, local trauma, hoof and body size have been suggested as contributing factors for OUC development. By comparing radiographs of front hooves from cold-blooded trotters with different age we wanted to evaluate when development of OUC in cold-blooded trotters occurs and if and when it stabilizes in relation to age and workload. Diagnosis and grading of OUC were based on radiological field examinations of 649 Swedish and Norwegian cold-blooded trotters front hooves. A hundred and forty-seven of the horses were re-examined 3-13 years (mean age 9, median 8 years) after the first occasion. All radiographs were evaluated blind, using two different grading systems for OUC. Work load, in form of number of races completed, and body size score were collected from official data. Four statistical ordinal regression models were used, compared and evaluated.ResultsWe identified a breakpoint at 2.80.38 years of age when ossification ends and proposed a simpler grading system with more consistent results. There was no significant correlation between body size and grade of OUC. Comparison of different statistical methods for evaluation of ordinal data revealed a piecewise linear regression model as most suitable.ConclusionsIndividuals with OUC developed this condition during the stage of life when their hooves develop in size. Results from this study can assist equine practitioners when examining and for understanding this condition in their clinical work and is also beneficial for the Scandinavian equine industry when devising breeding programs. PMID:25359553

Hedenstrm, Ulf O; Olsson, Ulf; Holm, Arne W; Wattle, Ove S

2014-10-30

103

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  

NASA Astrophysics Data System (ADS)

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 (Daz, 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.

Monteiro, Ana; Carvalho, Vnia; Gis, Joaquim; Sousa, Carlos

2013-11-01

104

ANALYTICAL APPROACH THE MASS DISTRIBUTION FUNCTION SUBHALOS AND COLD FRONTS GALAXY CLUSTERS  

E-print Network

Fujita, Craig Sarazin, 2 Masahiro Nagashima, 1 Taihei Yano Received January accepted May ABSTRACT galaxies: clusters: general galaxies: halos large­scale structure of universe X­rays: galaxies: clusters dark matter, the cold dark matter (CDM) theory vides a remarkably successful description large­scale

Sarazin, Craig

105

Comparison of subjective symptoms and cold prevention measures in winter between traffic control workers and construction workers in Japan.  

PubMed

To help making comfortable workplaces and to prevent health disorders induced by the exposure to moderate cold in two different groups of out-door workers, we conducted a survey to compare subjective symptoms and cold prevention measures in winter between traffic control workers and construction workers. The subjects of this study were 98 male traffic control workers and 149 male workers engaged in building construction. Work loads of traffic control workers and construction workers were estimated at RMR1-2 and RMR2-4, respectively. All subjects were asked to complete a self-administered questionnaire covering age, occupational career, working figure, present illness, past history of diseases, individual preventive measures to the cold, subjective symptoms in the winter (43 items) and subjective symptoms occurred during daytime working in the winter (6 items). In two parts of the construction workplaces (the place where a morning assembly was held and on the 7th floor of the construction site) dry bulb, wet bulb and globe temperatures were measured in January. Windchill Index (kcal/cm,(2) x h) was calculated by the measured dry bulb temperature and wind velocity. Mean values of dry bulb temperature between 9:00 and 16:30 in the place where a morning assembly was held for three days were between 4.8 +/- 1.2 degrees C at 9:00 am and 9.3 +/- 1.1 degrees C at noon. Mean values of Windchill Index in the place where a morning assembly was held were between 490.8+/-23.9 kcal/cm(2) x h at 9:30 am and 608.2+/-47.3 kcal/cm(2) x h at 2:30 pm. Occupational career, monthly working days, daily working hours, one way commuting hours, and daily smoking numbers of the traffic control workers were significantly shorter than the construction workers (p<0.01). There were no significant differences in the prevalence of chillness in the arms and legs between the traffic control workers (5.1%) and the construction workers (0.7%). Prevalence of wearing a warm underwear, body warmer, warm trousers, underpants, warm socks, shoe warmer and muffler in the traffic control workers were significantly higher than the construction workers. The subjective symptoms in winter complained most frequently were shoulder stiffness (51.0%), finger cold sensation (50.0%) and neck stiffness (48.0%) in the traffic control workers, and were easy to get fatigued (49.0%), lumbago (48.3%) and finger cold sensation (47.7%) in the construction workers. On the basis of the results obtained, it is clearly shown that the two groups are at the risk of disorders due to their working environment. Therefore, these workers are needed to undergo occupational health programs for prevention of cold exposure disorders. Applications of preventive countermeasures for both groups are discussed. PMID:19531914

Inaba, Ryoichi; Kurokawa, Junichi; Mirbod, Seyed Mohammad

2009-07-01

106

Cold fronts and metal anisotropies in the X-ray cool core of the galaxy cluster Zw 1742+3306  

NASA Astrophysics Data System (ADS)

Context. In recent years, our understanding of the cool cores of galaxy clusters has changed. Once thought to be relatively simple places where gas cools and flows towards the centre, now they are believed to be very dynamic places where heating from the central active galactic nucleus (AGN) and cooling, as inferred from active star formation, molecular gas, and H? nebulosity, find an uneasy energetic balance. Aims: We want to characterize the X-ray properties of the nearby cool-core cluster Zw 1742+3306, selected because it is bright at X-ray (with a flux greater than 10-11 erg s-1 cm-2 in the 0.1-2.4 keV band) and H? wavelengths (H? luminosity >1040 erg s-1). Methods: We used Chandra data to analyse the spatial and spectral properties of the cool core of Zw 1742+3306, a galaxy cluster at z = 0.0757 that emits in H? and presents the brightest central galaxy located in a diffuse X-ray emission with multiple peaks in surface brightness. Results: We show that the X-ray cool core of the galaxy cluster Zw 1742+3306 is thermodynamically very active with evidence of cold fronts and a weak shock in the surface brightness map and of an apparently coherent, elongated structure with metallicity greater than the value measured in the surrounding ambient gas by about 50%. This anisotropic structure is 280 90 kpc2 and is aligned with the cold fronts and with the X-ray emission on larger scales. We suggest that all these peculiarities in the X-ray emission of Zw 1742+3306 are either a very fine-tuned output of a sloshing gas in the cluster core or the product of a metal-rich outflow from the central AGN.

Ettori, S.; Gastaldello, F.; Gitti, M.; O'Sullivan, E.; Gaspari, M.; Brighenti, F.; David, L.; Edge, A. C.

2013-07-01

107

Shelf circulation prior to and post a cold front event measured from vessel-based acoustic Doppler current profiler  

NASA Astrophysics Data System (ADS)

Shelf circulation impacted by a shift in wind regime during the passage of an atmospheric cold front system is studied with a field survey over the mid-shelf of the South Atlantic Bight between Oct 4 and 9, 2004. Weak southerly winds preceded the cold front for a few days, followed by a rapid shift in wind direction and strengthening of northeasterly winds over a few more days. More than 93 h of acoustic Doppler current profiler (ADCP) data were obtained along an equilateral triangle of 105 km in perimeter, which was continuously occupied for 11 times. A harmonic analysis was applied to extract tidal and subtidal wind-driven flow components by collapsing the 93 hour data into one M2 tidal period. It was found that the cross-shelf flow was barely affected by the wind while the along-shelf flow responded with a spatially uniform and almost steadily increasing mean flow velocity, superimposed on an oscillatory tidal current. The wind induced along-shelf transport was estimated to be ~ 0.3 Sv over the inner and middle shelf. The net cross-shelf transport was negligible. Apparently, the northeasterly wind causes an along-shelf current which was subject to Coriolis force that sets up an increasing coastal sea level pressure gradient as the water kept piling up against the coast, which was confirmed by tide gauge data. The observations found that the flow field prior to the strong winds had more complicated structures including eddy-like features, while after the strong northeasterly winds, the flow became eddy free and uniform in space. A theoretical model solved by a Laplace Transform was used to examine the wind-driven flow mechanism and the results were compared with the observations of net along-shelf flow velocity.

Li, Chunyan; Chen, Changsheng

2014-11-01

108

Correlation between Cold- and Drought-Induced Frost Hardiness in Winter Wheat and Rye Varieties.  

PubMed

Exposure of six wheat (Triticum aestivum L.) and one rye (Secale cereale L.) cultivar to 40% relative humidity for 24 hours induced the same degree of freezing tolerance in seedling epicotyls as did cold conditioning for 4 weeks at 2 degrees C.Frost hardiness varietal relationships were the same in desiccation-stressed and cold-hardened seedlings. Drought stress could, therefore, be used as a rapid and simple method for inducing frost hardiness in seedling shoots in replacement of cold conditioning. PMID:16662170

Cloutier, Y; Siminovitch, D

1982-01-01

109

IRREGULAR SLOSHING COLD FRONTS IN THE NEARBY MERGING GROUPS NGC 7618 AND UGC 12491: EVIDENCE FOR KELVIN-HELMHOLTZ INSTABILITIES  

SciTech Connect

We present results from two {approx}30 ks Chandra observations of the hot atmospheres of the merging galaxy groups centered around NGC 7618 and UGC 12491. Our images show the presence of arc-like sloshing cold fronts (CFs) wrapped around each group center and {approx}100 kpc long spiral tails in both groups. Most interestingly, the CFs are highly distorted in both groups, exhibiting 'wings' along the fronts. These features resemble the structures predicted from non-viscous hydrodynamic simulations of gas sloshing, where Kelvin-Helmholtz instabilities (KHIs) distort the CFs. This is in contrast to the structure seen in many other sloshing and merger CFs, which are smooth and featureless at the current observational resolution. Both magnetic fields and viscosity have been invoked to explain the absence of KHIs in these smooth CFs, but the NGC 7618/UGC 12491 pair are two in a growing number of both sloshing and merger CFs that appear distorted. Magnetic fields and/or viscosity may be able to suppress the growth of KHIs at the CFs in some clusters and groups, but clearly not in all. We propose that the presence or absence of KHI distortions in CFs can be used as a measure of the effective viscosity and/or magnetic field strengths in the intracluster medium.

Roediger, E. [School of Engineering and Science, Jacobs University Bremen, Campus Ring 1, 28759 Bremen (Germany); Kraft, R. P.; Machacek, M. E.; Forman, W. R.; Nulsen, P. E. J.; Jones, C.; Murray, S. S., E-mail: e.roediger@jacobs-university.de [Harvard/Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2012-08-01

110

Lower Stratospheric Temperature Differences Between Meteorological Analyses in two cold Arctic Winters and their Impact on Polar Processing Studies  

NASA Technical Reports Server (NTRS)

A quantitative intercomparison of six meteorological analyses is presented for the cold 1999-2000 and 1995-1996 Arctic winters. The impacts of using different analyzed temperatures in calculations of polar stratospheric cloud (PSC) formation potential, and of different winds in idealized trajectory-based temperature histories, are substantial. The area with temperatures below a PSC formation threshold commonly varies by approximately 25% among the analyses, with differences of over 50% at some times/locations. Freie University at Berlin analyses are often colder than others at T is less than or approximately 205 K. Biases between analyses vary from year to year; in January 2000. U.K. Met Office analyses were coldest and National Centers for Environmental Prediction (NCEP) analyses warmest. while NCEP analyses were usually coldest in 1995-1996 and Met Office or NCEP[National Center for Atmospheric Research Reanalysis (REAN) warmest. European Centre for Medium Range Weather Forecasting (ECMWF) temperatures agreed better with other analyses in 1999-2000, after improvements in the assimilation model. than in 1995-1996. Case-studies of temperature histories show substantial differences using Met Office, NCEP, REAN and NASA Data Assimilation Office (DAO) analyses. In January 2000 (when a large cold region was centered in the polar vortex), qualitatively similar results were obtained for all analyses. However, in February 2000 (a much warmer period) and in January and February 1996 (comparably cold to January 2000 but with large cold regions near the polar vortex edge), distributions of "potential PSC lifetimes" and total time spent below a PSC formation threshold varied significantly among the analyses. Largest peaks in "PSC lifetime" distributions in January 2000 were at 4-6 and 11-14 days. while in the 1996 periods, they were at 1-3 days. Thus different meteorological conditions in comparably cold winters had a large impact on expectations for PSC formation and on the discrepancies between different meteorological analyses. Met Office. NCEP, REAN, ECMWF and DAO analyses are commonly used for trajectory calculations and in chemical transport models; the choice of which analysis to use can strongly influence the results of such studies.

Manney, Gloria L.; Sabutis, Joseph L.; Pawson, Steven; Santee, Michelle L.; Naujokat, Barbara; Swinbank, Richard; Gelman, Melvyn E.; Ebisuzaki, Wesley; Atlas, Robert (Technical Monitor)

2001-01-01

111

Synoptic climatological study on precipitation in the Hokuriku District of Central Japan associated with the cold air outbreak in early winter (With Comparison to that in midwinter for the 1983/1984 winter)  

NASA Astrophysics Data System (ADS)

In midwinter, heavy snowfall events are often brought in the Japan Sea side of the Japan Islands by the organized convective snowfall systems in the cold air outbreak situations. However, although the air temperature around the Japan Islands is still rather higher from November to early December ("early winter"), the "wintertime pressure pattern" often appears due to the considerable development of the Siberian high already in that season. Since the seasonal cycle in East Asia shows great variety with many rapid seasonal transitions influenced by the Asian monsoon system, detailed comparison of the daily precipitation climatology and the relating atmospheric processes in the cold air outbreak situations between early winter and midwinter would give us an interesting information for comprehending the overall aspects of such seasonal cycle there. Thus the present study firstly examined the daily precipitation climatology mainly at Takada, as an example for Hokuriku District, during the early to mid- winter of 1970/71 to 2009/10. Then the detailed analyses were made for the 1983/1984 winter (one of the coldest winters during that period) based on the operational meteorological data by JMA, including the ocean buoy data in the southern part of the Japan Sea for evaluating the sensible and the latent heat fluxes from the sea (referred to as SH and LH, respectively). The total precipitation at Takada in early winter was as large as in midwinter, although it was brought mainly not as snow but as rain. Such large climatological value was mainly reflected by the precipitation in the "wintertime pressure pattern" with large contribution of the days with more than 30 mm/day. Interestingly, mean daily precipitation in the "wintertime pressure pattern" in early winter was greater than in midwinter. It is noted that such features were generally found even in the latter half of the analysis period when the warmer winter years appeared more frequently than in the former half. According to the case study for 1983/84 winter, although the "wintertime pressure pattern" appeared rather frequently already from early November, each event of that pattern tended to persist only a several days. In addition, the organization of the shallow convective clouds in the cold air outbreak situation as often found in midwinter was not clearly observed. However, strong cold air advection in early winter as in midwinter over the warm underlying sea, at least in the mature stage of each "wintertime pressure situation", seems to enable the extremely huge amount of LH and the equivalently intense SH to that in midwinter, resulting in the large daily precipitation there through the enhancement of the air mass transformation process over the Japan Sea.

Kato, Kuranoshin; Nishimura, Nanako; Haga, Yuichi

2014-05-01

112

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 600700 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

Hlav?kov, Iva; Vtmvs, Pavel; antr??ek, Ji?; Kosov, Klra; Zelenkov, Sylva; Pril, Ilja Tom; Ovesn, Jaroslava; Hynek, Radovan; Kod?ek, Milan

2013-01-01

113

In vitro evaluation mimics influences of winter cold water ingestion on ruminal function  

Technology Transfer Automated Retrieval System (TEKTRAN)

Ingestion of cold feed and water may suddenly reduce ruminal temperature, which could result in decreased microbial activity and diet digestibility. The objective of this study was to investigate the association between critical rumen in vitro incubation temperature and activity of ruminal microorga...

114

Dominant black-capped chickadees pay no maintenance energy costs for their wintering status and are not better at enduring cold than subordinate individuals.  

PubMed

Winter requires physiological adjustments in northern resident passerines. Cold acclimatization is generally associated with an increase in physiological maintenance costs, measured as basal metabolic rate (BMR), and cold endurance, reflected by summit metabolic rate (M(sum)). However, several northern species also form social groups in winter and a bird's hierarchical position may influence the size of its metabolically active organs as well as its BMR. Winter metabolic performance in these species may therefore reflect a complex set of adjustments to both seasonal climatic variations and social environment. We studied the effect of social status on parameters of cold acclimatization (body mass, size of fat reserves and pectoral muscles, BMR and M(sum)) in free-living black-capped chickadees (Poecile atricapillus). Birds that were structurally large and heavy for their body size, mostly dominant individuals, carried more fat reserves and had larger pectoral muscles. However, social status had little effect on metabolic performance in the cold. Indeed, M(sum) was independent of social rank while mass-corrected BMR was slightly lower in dominant individuals, likely due to a statistical dilution effect caused by large metabolically inactive fat reserves. BMR and M(sum), whether considered in terms of whole-animal values, corrected for body mass or body size were nevertheless correlated, suggesting a functional link between these metabolic components. Our results therefore indicate that the energy cost of social dominance is not a generalized phenomenon in small wintering birds. PMID:22037961

Lewden, Agns; Petit, Magali; Vzina, Franois

2012-04-01

115

The bow shock, cold fronts and disintegrating cool core in the merging galaxy group RX J0751.3+5012  

NASA Astrophysics Data System (ADS)

We present a new Chandra X-ray observation of the off-axis galaxy group merger RX J0751.3+5012. The hot atmospheres of the two colliding groups appear highly distorted by the merger. The images reveal arc-like cold fronts around each group core, produced by the motion through the ambient medium, and the first detection of a group merger shock front. We detect a clear density and temperature jump associated with a bow shock of Mach number M = 1.9 0.4 ahead of the northern group. Using galaxy redshifts and the shock velocity of 1100 300 km s-1, we estimate that the merger axis is only 10 from the plane of the sky. From the projected group separation of 90 kpc, this corresponds to a time since closest approach of 0.1 Gyr. The northern group hosts a dense, cool core with a ram pressure stripped tail of gas extending 100 kpc. The sheared sides of this tail appear distorted and broadened by Kelvin-Helmholtz instabilities. We use the presence of this substructure to place an upper limit on the magnetic field strength and, for Spitzer-like viscosity, show that the development of these structures is consistent with the critical perturbation length above which instabilities can grow in the intragroup medium. The northern group core also hosts a galaxy pair, UGC 4052, with a surrounding IR and near-UV ring 40 kpc in diameter. The ring may have been produced by tidal stripping of a smaller galaxy by UGC 4052 or it may be a collisional ring generated by a close encounter between the two large galaxies.

Russell, H. R.; Fabian, A. C.; McNamara, B. R.; Edge, A. C.; Sanders, J. S.; Nulsen, P. E. J.; Baum, S. A.; Donahue, M.; O'Dea, C. P.

2014-10-01

116

Evaluating the role of fronts in habitat overlaps between cold and warm water species in the western North Pacific: A proof of concept  

NASA Astrophysics Data System (ADS)

Cold- and warm-water species' fishing grounds show a spatial synchrony around fronts in the western North Pacific (WNP). However, it is not yet clear whether a front (thermal, salinity or chlorophyll) acts as an absolute barrier to fish migration on either side or its structure allows interaction of species with different physiological requirements. Our objective was to assess potential areas of overlap between cold- and warm-water species using probabilities of presence derived from fishery datasets and remotely sensed environment data in the Kuroshio-Oyashio region in the WNP. Fishery data comprised skipjack tuna (Katsuwonus pelamis) fishing locations and proxy presences (derived from fishing night light images) for neon flying squid (Ommastrephes bartrami) and Pacific saury (Cololabis saira). Monthly (August-November) satellite remotely sensed sea-surface temperature, chlorophyll-a and sea-surface height anomaly images were used as environment data. Maximum entropy (MaxEnt) models were used to determine probabilities of presence (PoP) for each set of fishery and environment data for the area 35-45N and 140-160E. Maps of both sets of PoPs were compared and areas of overlap identified using a combined probability map. Results indicated that areas of spatial overlap existed among the species habitats, which gradually widened from September to November. The reasons for these overlaps include the presence of strong thermal/ocean-color gradients between cold Oyashio and warm Kuroshio waters, and also the presence of the sub-arctic front. Due to the high abundance of food along frontal zones, the species use the fronts as foraging grounds while confining within physiologically tolerable waters on either side of the front. The interaction zone around the front points to areas that might be accessible to both species for foraging, which suggests intense prey-predator interaction zones.

Mugo, Robinson M.; Saitoh, Sei-Ichi; Takahashi, Fumihiro; Nihira, Akira; Kuroyama, Tadaaki

2014-09-01

117

2012/13 abnormal cold winter in Japan associated with Large-scale Atmospheric Circulation and Local Sea Surface Temperature over the Sea of Japan  

NASA Astrophysics Data System (ADS)

On Japan, wintertime cold wave has social, economic, psychological and political impacts because of the lack of atomic power stations in the era of post Fukushima world. The colder winter is the more electricity is needed. Wintertime weather of Japan and its prediction has come under the world spotlight. The winter of 2012/13 in Japan was abnormally cold, and such a cold winter has persisted for 3 years. Wintertime climate of Japan is governed by some dominant modes of the large-scale atmospheric circulations. Yasunaka and Hanawa (2008) demonstrated that the two dominant modes - Arctic Oscillation (AO) and Western Pacific (WP) pattern - account for about 65% of the interannual variation of the wintertime mean surface air temperature of Japan. A negative AO brings about cold winter in Japan. In addition, a negative WP also brings about cold winter in Japan. Looking back to the winter of 2012/13, both the negative AO and negative WP continued from October through December. If the previous studies were correct, it would have been extremely very cold from October through December. In fact, in December, in accordance with previous studies, it was colder than normal. Contrary to the expectation, in October and November, it was, however, warmer than normal. This discrepancy signifies that an additional hidden circumstance that heats Japan overwhelms these large-scale atmospheric circulations that cool Japan. In this study, we therefore seek an additional cause of wintertime climate of Japan particularly focusing 2012 as well as the AO and WP. We found that anomalously warm oceanic temperature surrounding Japan overwhelmed influences of the AO or WP. Unlike the inland climate, the island climate can be strongly influenced by surrounding ocean temperature, suggesting that large-scale atmospheric patterns alone do not determine the climate of islands. (a) Time series of a 5-day running mean AO index (blue) as defined by Ogi et al., (2004), who called it the SVNAM index. For reference, the conventional AO index is shown by the gray line. (b) a 5-day running mean WP index, (c) area-averaged Surface Air Temperature anomalies in Japan, (d) Air Temperature anomalies, (e) heat flux anomalies, and (f) Sea Surface Temperature anomalies. The boxed area on the Sea of Japan indicates the area in which the (d)-(f) indexes were calculated.

Ando, Y.; Ogi, M.; Tachibana, Y.

2013-12-01

118

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

2013-05-15

119

Southern hemisphere winter cold-air mesocyclones: climatic environments and associations with teleconnections  

NASA Astrophysics Data System (ADS)

Cold-air mesocyclones remain a forecasting challenge in the southern hemisphere middle and higher latitudes, where conventional observations are lacking. One way to improve mesocyclone predictability is to determine their larger-scale circulation environments and associations with teleconnection patterns. To help realize this objective, reanalysis datasets on atmospheric and upper-ocean synoptic variables important in mesocyclone development are composited and compared to previously published mesocyclone spatial inventories. These analyses demonstrate a consistent association between higher frequencies of mesocyclones, greater sea ice extent and large positive differences in the SST minus low-altitude air temperature fields, coinciding with enhanced westerly low-level winds having a southerly component. Composites in the 1979 2001 period also were formed for opposite phases of El Nio Southern Oscillation (ENSO), the Southern Annular Mode (SAM) and the Trans-Polar Index (TPI). Regions likely to be favorable for mesocyclone development relative to climatology were identified. The largest (smallest) variations in meso-cyclogenesis occur in the South Pacific (South Indian Ocean, south of Australia), and are dominated by ENSO. The SAM and TPI are of secondary importance, yet still influential, and exhibit strong regional-scale variations.

Claud, C.; Carleton, A. M.; Duchiron, B.; Terray, P.

2009-08-01

120

Permafrost Distribution In NW Europe During Cold Glacial Phases Suggests Extensive Winter Sea-ice Cover In The North Atlantic Ocean  

NASA Astrophysics Data System (ADS)

The relation between surface conditions in the North Atlantic Ocean and permafrost conditions in NW Europe is used to constrain the extent of North Atlantic winter sea-ice cover. We compare atmospheric model simulations with prescribed different extents of sea-ice extents with European mean annual temperatures associated with permafrost: -8C (continuous permafrost) and -4C (discontinuous permafrost). This comparison suggests that during cold phases of the last glacial, the southern margin of permafrost in western Europe was controlled by the latitude of the winter sea-ice margin in the North Atlantic Ocean. This relationship indicates that reconstructions of permafrost extent in Europe may be used to constrain past winter sea-ice con- ditions in the North Atlantic Ocean. Accordingly, extensive North Atlantic sea-ice cover southwards to at least 50N is inferred during four phases of the Weichselian Pleniglacial and Late-glacial: (1) Early Pleniglacial (74-59 cal ky BP), (2) the Hasselo stadial (41.5-40 cal ky BP), (3) the Late Pleniglacial maximum cold phase (23-19 cal ky BP), (4) the Younger Dryas (12.7-11.5 cal ky BP). The extensive sea-ice cover for the phase of maximum cold agrees with the orginal CLIMAP reconstruction for the last glacial maximum, which has recently been questioned. However, the estimate for the Younger Dryas conflicts with reconstructions based on marine proxy data.

Renssen, H.; Vandenberghe, J.

121

Dynamics and ecological consequences of avian influenza virus infection in greater white-fronted geese in their winter staging areas  

Microsoft Academic Search

Recent outbreaks of highly pathogenic avian influenza (HPAI) in poultry have raised interest in the interplay between avian influenza (AI) viruses and their wild hosts. Studies linking virus ecology to host ecology are still scarce, particularly for non-duck species. Here, we link captureresighting data of greater white-fronted geese Anser albifrons albifrons with the AI virus infection data collected during capture

D. Kleijn; V. J. Munster; B. S. Ebbinge; D. A. Jonkers; G. J. D. M. Mskens; Y. Van Randen; R. A. M. Fouchier

2010-01-01

122

Wave and Bottom Sediment Interactions over a Submerged Sand Bank during the Winter Cold-Front Season, Western Louisiana  

Microsoft Academic Search

The Louisiana coast is experiencing severe coastal land losses due to geological proc- esses and human intervention. Replenishing the eroded beaches and the barrier islands with sand from offshore borrow sites is a plausible way to restore them. To assess the potential effects of sand mining from these offshore banks, in terms of physical proc- esses, a field survey was

Daijiro Kobashi; Felix Jose; Gregory Stone

123

Effect of Severe Winter Cold on the Photosynthetic Potentials of Three Co-occurring Evergreen Woody Species in a Mediterranean Forest, Catalonia (Spain)  

NASA Astrophysics Data System (ADS)

Evergreen tree species in the Mediterranean region have to cope with a wide range of environmental stress conditions from summer drought to winter cold. The winter period can lead to photoinhibition due to a combination of high solar irradiances and chilling temperatures which can reduce the light saturation point. However, Mediterranean winter mildness can lead periodically to favourable environmental conditions above the threshold for positive carbon balance benefitting evergreen woody species in contrast to winter deciduous species. The advantage of being able to photosynthesis all year round with a significant fraction in the winter month is compensating for the lower photosynthetic potentials during spring and summer in comparison to deciduous species. In this work, we investigated the physiological behaviour of three evergreen tree species (Quercus ilex, Pinus halepensis, Arbutus undeo) co-occurring in a natural and mature Mediterranean forest after a period of mild winter conditions and their response to a sudden period of intense cold weather. Therefore, we examined in each period the photosynthetic potentials by estimating the maximum carboxylation rate (Vcmax) and the maximum electron transport rate (Jmax) through gas exchange measurements. The results indicate that all species exhibited extraordinary high photosynthetic potentials during the first period of measurement as a response to the mild conditions. However, the sudden cold period affected negatively the photosynthetic potentials of Quercus ilex and A. unedo with reduction ranging between 37 to 45 %, whereas they were observed to be only insignificantly reduced in Pinus halepensis. Our results can be explained by previous classifications into photoinhibition-avoiding (P. halpensis) and photoinhibition-tolerant (Q. ilex, A. undeo) species on the basis of their susceptibility to dynamic photoinhibition (Martinez Ferri 2000). Photoinhibition tolerant species are characterised with a more dynamic photoinhibition which is associated with fast reversible mechanisms. In contrast, photoinhibition-avoiding species are able to maintain a sustained PS II photochemical efficiency. In conclusion, our results provide new information on the photosynthetic responses of co-occurring Mediterranean evergreen tree species in a natural environment to contrasting winter conditions.

Sperlich, Dominik; Gracia, Carlos; Peuelas, Josep; Sabat, Santi

2013-04-01

124

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

125

Organic and inorganic aerosol compositions in Ulaanbaatar, Mongolia, during the cold winter of 2007 to 2008: Dicarboxylic acids, ketocarboxylic acids, and ?-dicarbonyls  

NASA Astrophysics Data System (ADS)

To investigate the distributions and sources of water-soluble organic acids in the Mongolian atmosphere, aerosol samples (PM2.5, n = 34) were collected at an urban site (47.92N, 106.90E, 1300 m above sea level) in Ulaanbaatar, the capital of Mongolia, during the cold winter. The samples were analyzed for water-soluble dicarboxylic acids (C2-C12) and related compounds (ketocarboxylic acids and ?-dicarbonyls), as well as organic carbon (OC), elemental carbon, water-soluble OC, and inorganic ions. Distributions of dicarboxylic acids and related compounds were characterized by a predominance of terephthalic acid (tPh; 130 51 ng m-3, 19% of total detected organic acids) followed by oxalic (107 28 ng m-3, 15%), succinic (63 20 ng m-3, 9%), glyoxylic (55 18 ng m-3, 8%), and phthalic (54 27 ng m-3, 8%) acids. Predominance of terephthalic acid, which has not been reported previously in atmospheric aerosols, was mainly due to uncontrolled burning of plastic bottles and bags in home stoves for heating and waste incineration during the cold winter. This study demonstrated that most of the air pollutants were directly emitted from local sources such as heat and power plants, home stoves, and automobiles. Development of an inversion layer (<700 m above ground level) over the basin of Ulaanbaatar accelerated the accumulation of pollutants, causing severe haze episodes during the winter season.

Jung, Jinsang; Tsatsral, Batmunkh; Kim, Young J.; Kawamura, Kimitaka

2010-11-01

126

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; Klma, Miroslav; Vtmvs, Pavel; Vaek, Jakub; Hilgert-Delgado, Alois Albert; Ku?era, Vratislav

2013-12-15

127

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

128

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

129

Impacts of the North India Ocean SST on the extremely cold winters of 2011 and 2012 in the region of Da Hinggan Mountains and its western areas in China  

NASA Astrophysics Data System (ADS)

The study of the winter temperatures, averaged from the records of 11 observatories in the Da Hinggan Mountains and its western areas in China (DHM-WA), identified 11 extremely cold (? - 1.5 C) and 13 extremely warm winters (? + 1.5 C) during the past 60 years (1951-2010). The winters of 2011 and 2012 are another two extremely cold events. Aimed at exploring the climate causes, a comprehensive investigation is carried out on variations of some major atmospheric circulation components. Additionally, opposite circulation regimes are verified by examining the mean 500-hPa circulation patterns and sea level pressure (SLP) corresponding to 14 warm and 18 cold sea surface temperature (SST) phases over the North India Ocean (NIO) during the period of 1951-2010. Composite of an extremely cold winter usually includes a large and strong Siberian High, a deep East Asian trough to the west, an small and weak western Pacific Subtropical High to the east, a large North Polar vortex and a weakened westerly stream over Eurasia continent accompanied by a strong meridional winds from the polar region to lower latitude. Moreover, it has been found that a favorable circulation condition associated with the extremely cold winters to DHM-WA is mainly controlled by the SST over NIO in the previous warm season (June-September); This is primarily related to changes in the intensity of the Walker and Anti-Walker circulations, which subsequently influence the major circulation components and result in an extremely cold winter in DHM-WA.

Gao, Tao; Han, Jingwei; Gao, Lian; Yan, Wei

2014-08-01

130

Transcriptional responses of winter barley to cold indicate nucleosome remodelling as a specific feature of crown tissues  

Microsoft Academic Search

We report a series of microarray-based comparisons of gene expression in the leaf and crown of the winter barley cultivar\\u000a Luxor, following the exposure of young plants to various periods of low (above and below zero) temperatures. A transcriptomic\\u000a analysis identified genes which were either expressed in both the leaf and crown, or specifically in one or the other. Among

Anna Jansk; Alessio Aprile; Ji? Zme?nk; Luigi Cattivelli; Jaroslava Ovesn

2011-01-01

131

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

132

Effect of Cold Hardening on the Components of Respiratory Decarboxylation in the Light and in the Dark in Leaves of Winter Rye.  

PubMed Central

In the dark, all decarboxylation reactions are associated with the oxidase reactions of mitochondrial electron transport. In the light, photorespiration is also active in photosynthetic cells. In winter rye (Secale cereale L.), cold hardening resulted in a 2-fold increase in the rate of dark respiratory CO2 release from leaves compared with nonhardened (NH) controls. However, in the light, NH and cold-hardened (CH) leaves had comparable rates of oxidase decarboxylation and total intracellular decarboxylation. Furthermore, whereas CH leaves showed similar rates of total oxidase decarboxylation in the dark and light, NH leaves showed a 2-fold increase in total oxidase activity in the light compared with the dark. Light suppressed oxidase decarboxylation of end products of photosynthesis 2-fold in NH leaves and 3-fold in CH leaves in air. However, in high-CO2, light did not suppress the oxidase decarboxylation of end products. Thus, the decrease in oxidase decarboxylation of end products observed in the light and in air reflected glycolate-cycle-related inhibition of tricarboxylic acid cycle activity. We also showed that the glycolate cycle was involved in the decarboxylation of the end products of photosynthesis in both NH and CH leaves, suggesting a flow of fixed carbon out of the starch pool in the light. PMID:12226322

Hurry, V.; Keerberg, O.; Parnik, T.; Oquist, G.; Gardestrom, P.

1996-01-01

133

Inheritance of Cold Tolerance, Plant Height, Maturity and Other Characters in a Spring-Winter Barley Cross.  

E-print Network

. 7:77-94. Nilan, R. A. 1964. The cytology and gentics of barley 1951-62. Washington State Univ. Press. 278 pp. Reid, D. A. 1965. Inheritance of growth habit in barley (Hordeurn vulgare L. Emend. Lam.) Crop Sic. 5:141-14.5. Reid, D. A. 1963.... Winterhardiness of progenies from winter x spring barley (Hordeum vulgare, L. Enlend. Lam.) crosses. Crop Sci. 5:263-266. Rohcle, C. R. and C. F. Pulham. 1960. Genetics studies of winterhardiness in barley. Res. Bul. Seb. Agr. Exp. Sta. Xo. 193. Sclliemann...

Abo-Elenein, Rashad Ahmed; Atkins, I. M.; Pawlisch, E.; Gardenhire, J. H.; Porter, K. B.

1967-01-01

134

The effects of a mid-winter 8-week course of sub-sunburn sunbed exposures on tanning, vitamin D status and colds.  

PubMed

Like UV irradiation, which generates vitamin D(3) in the skin, the hormonally active metabolite, 1,25-dihydroxyvitamin D(3), boosts innate immunity against viruses and bacteria. Epidemiologic studies have found high vitamin D levels to be associated with lower risk of infections of the upper respiratory tract (colds). We have therefore performed an intervention study in 105 young adults (ages 18-30 years; 91% female) over a mid-winter 8-week period (January-March 2010). The participants were randomised to 3 groups: (A) subjected to 3 times a week sub-sunburn sunbed exposure (n = 35), (B) daily vitamin D supplementation, @ 1000 IU (n = 37), and (C) a control group without any intervention (n = 33). The mean serum level of 25-hydroxyvitamin D (25(OH)D) dropped from 62 to 55 nmol l(-1) in group C, while these levels rose from 62 to 109 and from 58 to 93 nmol l(-1) in groups A and B, respectively (p < 0.001). The skin on the chest darkened significantly in group A (mean difference in lightness, L*, equalled -5.7, p < 0.001), correlating significantly, but weakly, with increases in 25(OH)D (3.3 nmol l(-1) per unit drop in L*, R(2) = 0.17, p = 0.014). The percentage of self-reported colds with proper signs and symptoms was only slightly and not significantly reduced in groups A and B in comparison to group C: 57 and 51 versus 67%, respectively. Hence, the sub-sunburn sunbed treatment was effective in tanning and increasing the 25(OH)D serum level, more so than 1000 IU per day, but had no appreciable effect on colds. PMID:23104230

de Gruijl, Frank R; Pavel, Stan

2012-12-01

135

The impact of winter 2012 cold outbreak over the Northern Adriatic Sea dynamics: preliminary comparison among data and high resolution operational atmospheric models  

NASA Astrophysics Data System (ADS)

Shelf dense water formation (DWF) events may be taking place during winter time on the broad, shallow shelf in the northern region of the Adriatic basin exposed to the Bora winds, bringing cold, dry air from the north-east down the Dinaric Alps. Indeed, the resulting intense evaporation and cooling of the shelf waters may produce North Adriatic Dense Water (NAdDW), which then tends to sink and ''cascade'' all the way to the southern basin. During these rather episodic formation processes, more frequent during winter time, the main controlling factors are intense cold wind out- breaks, the ambient water density, preconditioned during late autumn, and also other factors, e.g. river discharges. When such processes of buoyancy extraction happen, several isopycnic surfaces outcrop and very often the whole water column (20-25 m deep) may be ventilated. However, the general process of northern water masses flowing to the southern part of the Adriatic basin is complex and far from being completely understood. In order to understand and model these processes, it is mandatory to utilize high resolution meteorological forcing fields and circulation models, at least to model particular events in Adriatic marine circulation, if not its longer term (e.g., seasonal) characteristics. The use of low resolution winds in fact necessarily implies a calibration factor to better match surface fluxes and to reproduce wind-driven circulation. This is particularly evident in the case of the cross-basin Bora pattern, because the complexity and small scale of Adriatic orography is often poorly reproduced in atmospheric models, while Bora flow is composed of an alternation of high and low wind speed 'strips' crossing the Adriatic in correspondence of the fine scale (10-100 km) Balkanic orographic gaps. Within the framework of activities of the Italian flagship Project "RITMARE" and of the FIRB "DECALOGO", we focused on the current meteorological modeling capabilities to describe an event of exceptionally dense water formation, registered during the 2012 winter in the northern Adriatic region. During late January and early February, indeed, the basin was characterized by a persistent and exceptional cold anomaly responsible for large energy losses due to cold and extremely strong winds. Sea waters temperatures dropped to about 6C and the Venice lagoon got partially covered by ice. In the period of interest, available measurements in the northern Adriatic Sea (temperature, salinity, density, wind speed, direction and inferred heat fluxes) were used, together with satellite measurements, to carry out a first semi-quantitative comparison among existing meteorological models implemented over the region. Namely, the work presents an intercomparison among three state-of-the-art, non-hydrostatic NWP models: COSMO-I7, WRF and MOLOCH. All models are run in operational mode, and their results are used by several Regional authorities and institutions for weather forecasting and support to civil protection decision. Therefore, this evaluation is a useful assessment preliminary to a full coupling of the above mentioned atmospheric models with existing ocean models already implemented in the region (e.g. ROMS in the COAWST system). Preliminary results show also some uncommon mesoscale structures reproduced by the models in the proximity of the central-south Italian coast, and highlight their possible influence on the local surface sea circulation. These effects will be soon explored by means of fully-coupled ocean-atmosphere models within on-going projects.

Davolio, Silvio; Miglietta, Mario M.; Carniel, Sandro; Benetazzo, Alvise; Buzzi, Andrea; Drofa, Oxana; Falco, Pierpaolo; Fantini, Maurizio; Malguzzi, Piero; Ricchi, Antonio; Russo, Aniello; Paccagnella, Tiziana; Sclavo, Mauro

2013-04-01

136

KELVIN-HELMHOLTZ INSTABILITIES AT THE SLOSHING COLD FRONTS IN THE VIRGO CLUSTER AS A MEASURE FOR THE EFFECTIVE INTRACLUSTER MEDIUM VISCOSITY  

SciTech Connect

Sloshing cold fronts (CFs) arise from minor merger triggered gas sloshing. Their detailed structure depends on the properties of the intracluster medium (ICM): hydrodynamical simulations predict the CFs to be distorted by Kelvin-Helmholtz instabilities (KHIs), but aligned magnetic fields, viscosity, or thermal conduction can suppress the KHIs. Thus, observing the detailed structure of sloshing CFs can be used to constrain these ICM properties. Both smooth and distorted sloshing CFs have been observed, indicating that the KHI is suppressed in some clusters, but not in all. Consequently, we need to address at least some sloshing clusters individually before drawing general conclusions about the ICM properties. We present the first detailed attempt to constrain the ICM properties in a specific cluster from the structure of its sloshing CF. Proximity and brightness make the Virgo Cluster an ideal target. We combine observations and Virgo-specific hydrodynamical sloshing simulations. Here, we focus on a Spitzer-like temperature-dependent viscosity as a mechanism to suppress the KHI, but discuss the alternative mechanisms in detail. We identify the CF at 90 kpc north and northeast of the Virgo center as the best location in the cluster to observe a possible KHI suppression. For viscosities {approx}> 10% of the Spitzer value KHIs at this CF are suppressed. We describe in detail the observable signatures at low and high viscosities, i.e., in the presence or the absence of KHIs. We find indications for a low ICM viscosity in archival XMM-Newton data and demonstrate the detectability of the predicted features in deep Chandra observations.

Roediger, E. [Hamburger Sternwarte, Universitaet Hamburg, Gojensbergsweg 112, D-21029 Hamburg (Germany)] [Hamburger Sternwarte, Universitaet Hamburg, Gojensbergsweg 112, D-21029 Hamburg (Germany); Kraft, R. P.; Forman, W. R.; Nulsen, P. E. J. [Harvard/Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)] [Harvard/Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Churazov, E., E-mail: eroediger@hs.uni-hamburg.de [Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Str. 1, D-85748 Garching (Germany)

2013-02-10

137

Bio-Optical Properties and Ocean Color Algorithms for Coastal Waters Influenced by the Mississippi River During a Cold Front Passage  

NASA Technical Reports Server (NTRS)

During the passage of a cold front in March 2002, bio-optical properties examined in coastal waters impacted by the Mississippi River indicated westward advective flows and increasing river discharge containing a larger nonalgal particle content 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 a concentration (Chl) showed seasonal variability. The exponential slope of the colored dissolved organic matter (CDOM) averaged 0.0161 plus or minus 0.00054 per nanometer, and for nonalgal absorption it averaged 0.011 per nanometer 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 square meters (mg Chl) sup -1)) being higher in offshore surface waters, values of phytoplankton absorption spectra at the SeaWiFS wavebands were highly correlated to modeled values. The normalized scattering spectral shapes and the mean spectrum were in agreement to observations in other coastal waters, while the backscattering ratios were on average lower in phytoplankton dominated surface waters (0.0101 plus or minus 0.002) and higher in near-bottom waters (0.0191 plus or minus 0.0045) with low Chl. Average percent differences in remote sensing reflectance R (sub rs) derived form modeled and in-eater radiometric measurements were highest in the blue wavebands (52%) and at sampling stations with a ore stratified water column. Estimates of Chl and CDOM absorption derived from SeaWiFS images generated using regional empirical algorithms were highly correlated to in situ data.

D'Sa Eurico J.; Miller, Richard L.; DelCastillo, Carlos

2006-01-01

138

Seasonal, synoptic and diurnal variation of atmospheric water-isotopologues in the boundary layer of Southwestern Germany caused by plant transpiration, cold-front passages and dewfall.  

NASA Astrophysics Data System (ADS)

Atmospheric water is an enormously crucial trace gas. It is responsible for ~70 % of the natural greenhouse effect (Schmidt et al., JGR, 2010) and carries huge amounts of latent heat. The isotopic composition of water vapor is an elegant tracer for a better understanding and quantification of the extremely complex and variable hydrological cycle in Earth's atmosphere (evaporation, cloud condensation, rainout, re-evaporation, snow), which in turn is a prerequisite to improve climate modeling and predictions. As H216O, H218O and HDO differ in vapor pressure and mass, isotope fractionation occurs due to condensation, evaporation and diffusion processes. In contrast to that, plants are able to transpire water with almost no isotope fractionation. For that reason the ratio of isotopologue concentrations in the boundary layer (BL) provides, compared to humidity measurements alone, independent and additional constraints for quantifying the strength of evaporation and transpiration. Furthermore the isotope ratios contain information about transport history of an air mass and microphysical processes, that is not accessible by humidity measurements. Within the project MUSICA (MUlti-platform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water) a commercial Picarro Analyzer L2120-i is operated at Karlsruhe in Southwestern Germany, which is continuously measuring the isotopologues H216O, HDO and H218O of atmospheric water vapor since January 2012. A one year record of H216O, HDO and H218O shows clear seasonal, synoptic and diurnal characteristics and reveals the main driving processes affecting the isotopic composition of water vapor in the Middle European BL. Changes in continental plant transpiration and evaporation throughout the year lead to a slow seasonal HDO/H216O-variation, that cannot be explained by pure Rayleigh condensation. Furthermore, cold-front passages from NW lead to fast and pronounced depletion of the HDO/H216O-ratio within minutes. Superimposed to these variations are local diurnal processes like dewfall, which cause a diurnal pattern captured by the deuterium excess.

Christner, Emanuel; Dyroff, Christoph; Kohler, Martin; Zahn, Andreas; Gonzales, Yenny; Schneider, Matthias

2013-04-01

139

Ocean backscatter across the Gulf Stream sea surface temperature front  

SciTech Connect

Ocean backscatter was measured by the Jet Propulsion Laboratory, with the airborne NUSCAT K{sub u}-band scatterometer, across the Gulf Stream sea surface temperature front during the Surface Wave Dynamics Experiment off the coast of Virginia and Maryland in the winter of 1991. Backscatter across the front between the National Oceanic and Atmospheric Administration experimental coastal buoy A (44024) on the cold side and Discus C buoy (44023) on the warm side shows a difference of more than 5 dB for vertical polarization in many cases. This large frontal backscatter change is observed in all upwind, downwind, and crosswind directions. The sea surface temperature difference measured by the buoys was about 9{degrees}C. The corresponding difference in wind speed cannot account for the large backscatter change in view of geophysical model functions depending only on neutral wind velocity such as SASS. The measured backscatter also has larger upwind-downwind and upwind-crosswind ratios compared to the model results. Furthermore, NUSCAT data reveal that upwind backscatter on the cold side was smaller than or close to crosswind backscatter on the warm side for incidence angles between 30{degrees} to 50{degrees}. This suggests that the temperature front can be detected by the scatterometer at these incidence angles for different wind directions in the cold and warm sides.

Nghiem, S.V.; Li, F.K. [California Institute of Technology, Pasadena, CA (United States)

1997-06-01

140

Printed on 100% recycled post consumer paper Winter Hike  

E-print Network

on our trails or in your own backyard during the winter. In winter when the days are cold and short, many it's cold outside, winter is a wonderful time to explore nature. Here are a few things to discover, or moths. A hole in a tree. Animals sometimes use holes in trees to escape the cold weather. A tunnel

Shyy, Wei

141

Sequence of surface meteorological variables with the passage of winter cold fronts in the United States east of the Rocky Mountains  

E-print Network

questions (even when I was unsure of what I was asking). Thanks to both of you for always greeting me with a smile even when I only brought more forms to sign. I would also like to thank my good Iriend Paul Kaman for his expertise with Microsoft Excel...

Huckaby, Daniel Dale

2012-06-07

142

Winter Storms and Extreme Cold  

MedlinePLUS

... a few hours to a blizzard with blinding, wind-driven snow that lasts for several days. Many ... by dangerously low temperatures and sometimes by strong winds, icing, sleet and freezing rain. One of the ...

143

Implementation of Cold-Cloud Processes in a Source-Oriented WRF/Chem Model to Study a Winter Storm in California  

NASA Astrophysics Data System (ADS)

Mineral dust particles commonly have a favorable arrangement of surface sites that allows them to serve as ice nuclei (IN). Secondary coatings that condense on mineral dust particles may reduce their ability to serve as IN. Both of these effects point to the importance of the particle mixing state when predicting cloud condensation nuclei (CCN) / IN concentrations. The source-oriented Weather Research and Forecasting chemistry model (SOWC) was modified to include cold cloud processes and applied to investigate how source-oriented aerosols influence cloud and ice formation and optical properties in the atmosphere. SOWC tracks 6-dimensional chemical variables (X, Z, Y, Size Bins, Source Types, Species) through an explicit simulation of atmospheric chemistry and physics. Particle radius and number concentration are conserved for each source type and size bin. Simulations in this study use 38 chemical species from 6 emission sources (wood smokes, gasoline, diesel, meat cooking, dust, and other aerosol types) and 8 size bins, spanning the particle diameter range from 0.01 to 10 microns. A new source-oriented hydrometeors module was implemented into the SOWC model to simulate microphysics processes with all source-oriented hydrometeors (cloud, ice, rain, snow and graupel) using the Morrison two-moment microphysics scheme. In our study, all aerosol source types can activate to form cloud droplets based on the Khler theory, and dust is the only source of IN. We considered the impact of Asian dust on the ice formation in clouds over the Sierra Nevada mountain range during the CalWater field campaign (2011) and estimated dust contributions to total IN concentrations. Aerosols within hydrometeors alter the radiative properties of the cloud droplets. The Goddard shortwave and longwave radiation schemes were modified to interact with source-oriented aerosols and hydrometeors so that aerosol direct and indirect effects could be studied. Geometric-optics approach in the radiation schemes considered the chemistry components and the physical shape of ice crystal to more accurately calculate the atmospheric optical thickness, signal scattering albedo, and asymmetry factor. The enhanced SOWC model was implemented to study a winter storm event that occurred on February 16th, 2011, in California, and the results are compared to the measurements obtained during the CalWater field campaign.

Lee, H.; Chen, S.; Kleeman, M.

2013-12-01

144

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

145

Investigation of the relationship between permafrost distribution in NW Europe and extensive winter sea-ice cover in the North Atlantic Ocean during the cold phases of the Last Glaciation  

NASA Astrophysics Data System (ADS)

Atmospheric model simulations with different extents of sea-ice are compared with reconstructed European mean annual temperatures derived from permafrost indicators. Analysis of the results suggest that during cold phases of the Last Glacial, the southern margin of permafrost in western Europe was controlled by the latitude of the winter sea-ice margin in the North Atlantic Ocean. In this case reconstructions of permafrost extent in Europe may be used to constrain past winter sea-ice conditions in the North Atlantic Ocean. Accordingly, extensive North Atlantic sea-ice cover southwards to at least 50N is inferred during four phases of the Last Glaciation: (1) Early Pleniglacial (74- 59 cal kyr BP ), (2) the Hasselo Stadial (41.5- 40 cal kyr BP ), (3) the LGM (23- 19 cal kyr BP ) and (4) the Younger Dryas (12.7- 11.5 cal kyr BP ). The extensive sea-ice cover for the phase of maximum cold disagrees with recent studies suggesting a relatively warm North Atlantic during the LGM, while it agrees with the original CLIMAP reconstruction. Moreover, the estimate for the Younger Dryas cooling conflicts with reconstructions based on marine proxy data.

Renssen, H.; Vandenberghe, J.

2003-02-01

146

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

147

Mammals in Winter.  

ERIC Educational Resources Information Center

Mammals that tolerate the winter cold and stay active all year exploit the harsh northern climate to their advantage. By simple experiments and observation you can better understand their adaptations which include furry bodies, snowshoe feet, extra blubber, light coloration, and strategically distributed food caches. (JHZ)

Wapner, Suzanne

1985-01-01

148

Fronts and frontogenesis as revealed by high time resolution data  

NASA Technical Reports Server (NTRS)

Upper air sounding are used to examine a cold front of average intensity. Vertical cross sections of potential temperature and wind, and horizontal analyses were compared and adjusted for consistency. These analyses were then used to study the evolution of the front, found to consist of a complex system of fronts occurring at all levels of the troposphere. Low level fronts were strongest at the surface and rapidly weakened with height. Fronts in the midddle troposphere were much more intense. The warm air ahead of the fronts was nearly barotropic, while the cold air behind was baroclinic through deep layers. A deep mixed layer was observed to grow in this cold air.

Frank, A. E.; Barber, D. A.

1977-01-01

149

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

150

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

151

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

152

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

153

Atmospheric density remote sensing of mesosphere and thermosphere to be used for spacecraft design by adopting VHF radar and HF Doppler sounder at low latitude west Pacific site during winter time  

NASA Technical Reports Server (NTRS)

Simultaneous observations of VHF radar and HF Doppler array systems located at Chung Li (Taiwan) are used to observe three-dimensional wind speeds and gravity waves. The density perturbations are determined at different altitudes of the mesosphere and thermosphere during weak convective motions of the cold front in the winter. The present observations are believed to be valuable for space projects dealing with the low-latitude atmosphere.

Hung, R. J.; Tsao, Y. D.; Johnson, D. L.; Chen, A. J.; Lee, C. C.

1989-01-01

154

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

155

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

Richard Konicek-Moran

2008-04-01

156

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

Microsoft Academic Search

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

David L. Swanson

2001-01-01

157

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

158

Winter Wonderlands  

ERIC Educational Resources Information Center

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

Coy, Mary

2011-01-01

159

Dust transport over Iraq and northwest Iran associated with winter Shamal: A case study  

NASA Astrophysics Data System (ADS)

Dynamical processes leading to dust emission over Syria and Iraq, in response to a strong winter Shamal event as well as the subsequent transport of dust over Iraq and northwest Iran, are analyzed on the basis of a case study (22-23 February 2010) using a suite of ground-based and spaceborne remote sensing platforms together with modeling tools. Surface measurements on 22 February show a sharp reduction in horizontal visibility over Iraq occurring shortly after the passage of a cold front (behind which the northwesterly Shamal winds were blowing) and that visibilities could be as low as 1 km on average for 1-2 days in the wake of the front. The impact of the southwesterly Kaus winds blowing ahead (east) of the Shamal winds on dust emission over Iraq is also highlighted. Unlike what is observed over Iraq, low near-surface horizontal visibilities (<1 km) over northwest Iran are observed well after the passage of the cold front on 23 February, generally in the hours following sunrise. Ground-based lidar measurements acquired in Zanjan show that, in the wake of the front, dust from Syria/Iraq was transported in an elevated 1 to 1.5 km thick plume separated from the surface during the night/morning of 23 February. After sunrise, strong turbulence in the developing convective boundary layer led to mixing of the dust into the boundary layer and in turn to a sharp reduction of the horizontal visibility in Zanjan. The timing of the reduction of surface horizontal visibility in other stations over northwest Iran (Tabriz, Qom, and Tehran) is consistent with the downward mixing of dust in the planetary boundary layer just after sunset, as evidenced in Zanjan. This study sheds new light on the processes responsible for dust emission and transport over Iraq and northwest Iran in connection with winter Shamal events. Enhanced knowledge of these processes is key for improving dust forecasts in this region.

Abdi Vishkaee, Farhad; Flamant, Cyrille; Cuesta, Juan; Oolman, Larry; Flamant, Pierre; Khalesifard, Hamid R.

2012-02-01

160

Observation of dust emission and transport over Iraq and northwest Iran associated with winter Shamal  

NASA Astrophysics Data System (ADS)

Dynamical processes leading to dust emission over Syria and Iraq, in response to a strong winter Shamal event as well as the subsequent transport of dust over Iraq and northwest Iran, are analyzed on the basis of a case study (22-23 February 2010) using a suite of ground-based and space-borne remote sensing platforms together with modeling tools. Surface measurements on 22 February show a sharp reduction in horizontal visibility over Iraq occurring shortly after the passage of a cold front (behind which the northwesterly Shamal winds were blowing) and that visibilities could be as low as 1 km on average for one to two days in the wake of the front. The impact of the southwesterly Kaus winds blowing ahead (east) of the Shamal winds on dust emission over Iraq is also highlighted. Unlike what is observed over Iraq, low near-surface horizontal visibilities (less than 1 km) over northwest Iran are observed well after the passage of the cold front on 23 February, generally in the hours following sunrise. Ground-based lidar measurements acquired in Zanjan show that, in the wake of the front, dust from Syria/Iraq was transported in an elevated 1 to 1.5 km thick plume separated from the surface during the night/morning of February. After sunrise, strong turbulence in the developing convective boundary layer led to mixing of the dust into the boundary layer and in turn to a sharp reduction of the horizontal visibility in Zanjan. The timing of the reduction of surface horizontal visibility in other stations over northwest Iran (Tabriz, Qom and Tehran) is consistent with the downward mixing of dust in the PBL just after sunset, as evidenced in Zanjan. This study shades new light on the processes responsible for dust emission and transport over Iraq and northwest Iran in connection with winter Shamal events. Enhanced knowledge of these processes is key for improving dust forecasts in this region.

Flamant, C.; Abdi Vishkaee, F.; Cuesta, J.; Khalesifard, H.; Oolman, L.; Flamant, P.

2012-04-01

161

Effects of a Short-Term Shift to Low Temperature and of Long-Term Cold Hardening on Photosynthesis and Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase and Sucrose Phosphate Synthase Activity in Leaves of Winter Rye (Secale cereale L.).  

PubMed Central

The effect of a short-term (hours) shift to low temperature (5[deg]C) and long-term (months) cold hardening on photosynthesis and carbon metabolism was studied in winter rye (Secale cereale L. cv Musketeer). Cold-hardened plants grown at 5[deg]C exhibited 25% higher in situ CO2 exchange rates than nonhardened plants grown at 24[deg]C. Cold-hardened plants maintained these high rates throughout the day, in contrast to nonhardened plants, which showed a gradual decline in photosynthesis after 3 h. Associated with the increase in photosynthetic capacity following cold hardening was an increase in ribulose-1,5-bisphosphate carboxylase/oxygenase and sucrose phosphate synthase activity and 3- to 4-fold increases in the pools of associated metabolites. Leaves of nonhardened plants shifted overnight to 5[deg]C required 9 h in the light at 5[deg]C before maximum rates of photosynthesis were reached. The gradual increase in photosynthesis in leaves shifted to 5[deg]C was correlated with a sharp decline in the 3-phosphoglycerate/triose phosphate ratio and by an increase in the ribulose bisphosphate/3-phosphoglycerate ratio, indicating the gradual easing of aninorganic phosphate-mediated feedback inhibition on photo-synthesis. We suggest that the strong recovery of photosynthesis in winter rye following cold hardening indicates that the buildup of photosynthetic enzymes, as well as those involved in sucrose synthesis, is an adaptive response that enables these plants to maximize the production of sugars that have both cryoprotective and storage functions that are critical to the performance of these cultivars during over-wintering. PMID:12232378

Hurry, V. M.; Malmberg, G.; Gardestrom, P.; Oquist, G.

1994-01-01

162

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

163

Winter Weather  

NSDL National Science Digital Library

This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Weather affects our everyday lives. Some days it's sunny and some days its not. The years weather is split up into seasons. 1. What are the four seasons? 2. What kind of weather do you see in the summer? 3. What kind of weather is unique to winter? 4. ...

Mrs. Bellows

2009-09-28

164

Radiative magnetized thermal conduction fronts  

NASA Technical Reports Server (NTRS)

The evolution of plane-parallel magnetized thermal conduction fronts in the interstellar medium (ISM) was studied. Separating the coronal ISM phase and interstellar clouds, these fronts have been thought to be the site of the intermediate-temperature regions whose presence was inferred from O VI absorption-line studies. The front evolution was followed numerically, starting from the initial discontinuous temperature distribution between the hot and cold medium, and ending in the final cooling stage of the hot medium. It was found that, for the typical ISM pressure of 4000 K/cu cm and the hot medium temperature of 10 to the 6th K, the transition from evaporation to condensation in a nonmagnetized front occurs when the front thickness is 15 pc. This thickness is a factor of 5 smaller than previously estimated. The O VI column densities in both evaporative and condensation stages agree with observations if the initial hot medium temperature Th exceeds 750,000 K. Condensing conduction fronts give better agreement with observed O VI line profiles because of lower gas temperatures.

Borkowski, Kazimierz J.; Balbus, Steven A.; Fristrom, Carl C.

1990-01-01

165

Interannual Variation of the East Asian Cold Surge Activity  

Microsoft Academic Search

The occurrence frequency of the east Asian cold surge exhibits an interannual variation in concert with the El Nio Southern Oscillation (ENSO) cycle. That is, the cold surge occurs more (less) frequently during warm (cold) ENSO winters. Because the cold surge high low dipoles are coupled with the upper-level synoptic short waves, any mechanism modulating the activity of these waves

Tsing-Chang Chen; Wan-Ru Huang; Jin-Ho Yoon

2004-01-01

166

Thermohaline Front at the Mouth of Ise Bay  

Microsoft Academic Search

The detailed structure of the thermohaline front at the mouth of Ise Bay during winter has been investigated by intensive field observation. The transport of suspended matter from Ise Bay to the Pacific Ocean through the thermohaline front has also been investigated using the data from a time-series sediment trap, a current meter and a nephelometer moored at the bay

TETSUO YANAGI; XINYU GUO; TOSHIRO SAINO; TAKASHI ISHIMARU; SINICHIRO NORIKI

167

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

USGS Publications Warehouse

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

Bergstedt, Roger A.; O'Gorman, Robert

1989-01-01

168

Climate warming will not decrease winter mortality  

NASA Astrophysics Data System (ADS)

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

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

2014-03-01

169

Winter Weather  

MedlinePLUS

... warm, sweet beverages. Avoid drinks with alcohol. Provide engineering controls such as radiant heaters. Types of Cold ... caused by the freezing of the skin and tissues. Frostbite can cause permanent damage to the body, ...

170

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 ...

171

Winter Workshop.  

ERIC Educational Resources Information Center

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

Council of Outdoor Educators of Quebec, Montreal.

172

Winter Math  

NSDL National Science Digital Library

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

Petti, Wendy

2009-01-13

173

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.

174

Winter Hydrographer  

USGS Multimedia Gallery

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

175

Pressure transient method for front tracking  

SciTech Connect

A pressure transient technique for tracking the advance of cold water fronts during water flooding and goethermal injection operations has been developed. The technique is based on the concept that the steady state pressure buildup in the reservoir region inside the front can be calculated by a fluid skin factor. By analyzing successive pressure falloff tests, the advance of the front in the reservoir can be monitored. The validity of the methods is demonstrated by application to three numerically simulated data sets, a nonisothermal step-rate injection test, a series of pressure falloffs in a multilayered reservoir, and a series of pressure falloff tests in a water flooded oil reservoir.

Benson, S.M.; Bodvarsson, G.S.

1983-08-01

176

Seasonal variation in thermohaline and tidal fronts, Seto Inland Sea, Japan  

Microsoft Academic Search

Seasonal variations in the positions and strengths of a thermohaline front and a tidal front, situated near Hayasui Straits in the Seto Inland Sea, Japan, were investigated from 11 April 1974 to 31 March 1975. The thermohaline front was intensified in winter in the northern part of Hayasui Straits, due to the cooling through the sea surface. Solar heating through

Tetsuo Yanagi; Takashi Koike

1987-01-01

177

Titan's Winter Polar Vortex  

NASA Technical Reports Server (NTRS)

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

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

2008-01-01

178

EXTERIOR VIEW OF THE FRONT AND SOUTHWEST SIDE OF BUILDING ...  

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

EXTERIOR VIEW OF THE FRONT AND SOUTHWEST SIDE OF BUILDING 190 FACING NORTH. - U.S. Naval Base, Pearl Harbor, Warehouse & Cold Storage Building, North corner of Pokomoke Street & Hornet Avenue, Pearl City, Honolulu County, HI

179

EXTERIOR VIEW OF THE FRONT AND NORTHEAST SIDE OF BUILDING ...  

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

EXTERIOR VIEW OF THE FRONT AND NORTHEAST SIDE OF BUILDING 190 FACING WEST. - U.S. Naval Base, Pearl Harbor, Warehouse & Cold Storage Building, North corner of Pokomoke Street & Hornet Avenue, Pearl City, Honolulu County, HI

180

Leap Day 2012 Severe Storm Front - Duration: 0:26.  

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 ...

181

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

182

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 ...

Schilling, Ashley

2010-05-26

183

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

184

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

185

Winter thunderstorms in central Europe in the past and the present  

NASA Astrophysics Data System (ADS)

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

Munzar, Jan; Franc, Marek

186

Winter Blast.  

ERIC Educational Resources Information Center

Describes an art lesson for fifth- and sixth-grade students where they learn about the cold colors on the color wheel and apply that knowledge as they create a picture of a snowstorm. Explains that the students depict a snowstorm by layering the colors and drawings of snowflakes to make a three-dimensional effect. (CMK)

MacDonald, Beverley

1999-01-01

187

The Common Cold  

NSDL National Science Digital Library

When winter rolls around and we begin to spend more time indoors, the common cold becomes an unfortunate reality for many of us. But for something as common as the cold, misconceptions about it are remarkably common as well. The following collection of Web sites provides an in-depth look at the cold and the cold virus.The first site (1) comes from the Common Cold Care Center of Cardiff University in Wales, and offers a thorough and highly readable introduction to the common cold, including sections on conventional and alternative cold medications. Readers can brush up on their basic virology with the next Web site from HowStuffWorks to get a clear, general idea of how the cold virus infects the body (2). This site also explains why antibiotics have no effect on a virus, and includes numerous hypertext links to related HowStuffWorks Web pages. KidsHealth for Parents, a service of the Nemours Foundation, provides a straightforward guide to the symptoms of cold vs. flu, while also offering information on flu treatment options (3). The next Web site, from University of Guelph, contains an easy-to-understand comparison of bacteria and viruses (4). Readers can learn more about rhinoviruses, the family of viruses which account for about one-third of all colds, in the following Web site from the University of South Carolina's Microbiology and Immunology Online (5). The next Web site offers visitors a close-up look at human rhinovirus 14 with over a dozen 3-D images and movies from the University of Wisconsin-Madison Bock Laboratory (6). The following site describes the findings, as detailed in the Proceedings of the National Academy of Sciences, of a Purdue University research team that has analyzed on an atomic scale the structure of the cellular receptor that binds cold-causing viruses (7). And finally, find out about common cold clinical trials with ClinicalTrial.gov, a service of the National Institutes of Health (8).

Sohmer, Rachel.

2003-01-01

188

Winter snow  

NSDL National Science Digital Library

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

Peterson, Lori

2009-09-28

189

Building a Weather-Ready Nation Winter Weather Safety  

E-print Network

-Ready Nation Flooding Winter Weather Safety www.weather.gov · Flooding is possible due to snowmelt, ice jams and coastal storms such as Nor'easters. · Ice jams are common during the winter. · As ice moves downstream www.weather.gov · Snow/Ice · Blizzards · Flooding · Cold Temperatures #12;Building a Weather

190

REMEDIES FOR THE COMMON COLD If you catch a cold, you can expect to be sick for about a week . . . but, that doesn't  

E-print Network

REMEDIES FOR THE COMMON COLD If you catch a cold, you can expect to be sick for about a week which is another reason colds are more common in the winter! Parched air dries mucus membranes causing cold and flu symptoms in 2 ways: First, it acts as an anti-inflammatory by inhibiting the movement

O'Toole, Alice J.

191

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.

192

Winter bat activity in the Canadian prairies  

Microsoft Academic Search

Periodic arousal from hibernation among mammalian hibernators is poorly understood. In bats, arousal is often associated with flight. We acoustically monitored two rocky areas along the Red Deer River in southeastern Alberta for bat activity in autumn, winter, and spring months. We found bats to be active in all months and at unexpectedly cold tem- peratures (coldest activity -8 8C).

C. L. Lausen; R. M. R. Barclay

2006-01-01

193

Common cold  

MedlinePLUS

The common cold usually causes a runny nose, nasal congestion, and sneezing. You may also have a sore throat, cough, ... It is called the common cold for good reason. There are over one billion colds in the United States each year. You and your children will ...

194

ORIGINAL PAPER Climatology of winter transition days for the contiguous  

E-print Network

for the continental USA. We identify four subtypes of the Transition category based on intra-day sea level pressure days in which the dew point temperature and pressure both rise are more frequently observed across cold front frequency has significantly increased in the Northeast and Midwest regions, and warm front

Sheridan, Scott

195

The impact of ENSO and the Arctic Oscillation on winter temperature extremes in the southeast United States  

Microsoft Academic Search

The winter mean temperature and the cold extremes are better explained by AOThe warm extremes are linked to both ENSO and the AOChanging nature of ENSO impact on cold extremes before and after ?1980 is found

Young-Kwon Lim; Siegfried D. Schubert

2011-01-01

196

The chronology of strong marine cold-air outbreaks  

NASA Astrophysics Data System (ADS)

Marine cold air outbreaks (MCAOs) are large-scale incursions of cold air into regions over warm, open ocean. The increased surface heat fluxes during MCAOs impact the ocean and may lead to severe weather on a range of spatial and temporal scales, such as polar lows, roll clouds, arctic fronts, fog or rapid intensification of extratropical lows. Over the Nordic Seas, where the sea surface temperature remains high throughout winter, MCAOs are common in periods of northerly flow. The spatial and temporal distribution of MCAOs in this region are primarily dictated by the synoptic atmospheric circulation, and it has been shown that high pressure anomalies over the eastern margin of the Nordic Seas (over Greenland and Iceland) are conducive to MCAOs. Here we investigate the hypothesis that this "background field" channels synoptic disturbances into the Nordic Seas, by separating the flow fields during strong MCAOs into low- and high- frequency components. The results show that strong MCAOs endure for several days in a row and that ridging over the Iceland-Greenland region is an important precursor. A large portion of MCAOs develop due to disturbances propagating through the Fram Strait from the north, rather than along the more commonly assumed path along the westerly North Atlantic storm track. Furthermore, we show that there is a clear correspondence between monthly means of flow fields and strong MCAOs. This indicates that certain properties of MCAOs in the future may be deduced from projected changes to the low-frequency atmospheric circulation.

Kolstad, E.; Seierstad, I. A.

2008-12-01

197

Cold Pools in the Columbia Basin  

SciTech Connect

Persistent midwinter cold air pools produce multi-day periods of cold, dreary weather in valleys and basins. Persistent stable stratification leads to the buildup of pollutants and moisture in the pool. Because the pool sometimes has temperatures below freezing while the air above is warmer, freezing precipitation often occurs with consequent effects on transportation and safety. Forecasting the buildup and breakdown of these cold pools is difficult because the physical mechanisms leading to their formation, maintenance, and destruction have received little study. This paper provides a succinct meteorological definition of a cold pool, develops a climatology of Columbia Basin cold pools, and analyzes remote and in situ temperature and wind sounding data for two winter cold pool episodes that were accompanied by fog and stratus, illustrating many of the physical mechanisms affecting cold pool evolution.

Whiteman, Charles D.; Zhong, Shiyuan; Shaw, William J.; Hubbe, John M.; Bian, Xindi; Mittelstadt, J.

2001-01-01

198

Large-Eddy Observation of Post-Cold-Frontal Continental Stratocumulus  

E-print Network

United States on 8 April 2006. The stratocumulus occurred in cold-air and dry-air advection behind a surface cold front. LEOs were obtained from millimeter-wavelength cloud radar and micropulse lidar, whereas traditional meteorological observations...

Mechem, David B.; Kogan, Yefim L.; Schultz, David M.

2010-10-01

199

Corrugation crack front waves  

E-print Network

The paper presents a model of a dynamic crack with a wavy surface. So far, theoretical analysis of crack front waves has been performed only for in-plane perturbations of the crack front. In the present paper, generalisation is given to a more general three-dimensional perturbation, and equations that govern corrugation crack front waves are derived and analysed.

J. R. Willis; N. V. Movchan; A. B. Movchan

2012-06-05

200

Cold Stress  

MedlinePLUS

... Whenever temperatures drop decidedly below normal and as wind speed increases, heat can more rapidly leave your ... severe winter weather threatens. NOAA: National Weather Service Wind Chill Chart Additional Resources American Conference of Governmental ...

201

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

202

On the effects of vertical air velocity on winter precipitation types  

NASA Astrophysics Data System (ADS)

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 simulate this gentle ascent (?10 cm/s) of warm air. The initial temperature profile has an above 0C inversion, a lower subfreezing layer, and precipitation falls from above the temperature inversion. The cloud model is coupled to a double-moment microphysics scheme that simulates the production of various types of winter precipitation. The results are compared with those from a previous study carried out in still air. Based on the temporal evolution of surface precipitation, snow reaches the surface significantly faster than in still air whereas other precipitation types including freezing rain and ice pellets have a shorter duration. Overall, even weak background vertical ascent has an important impact on the precipitation reaching the surface, the time of the elimination of the melting layer, and also the evolution of the lower subfreezing layer.

Thriault, J. M.; Stewart, R. E.

2007-03-01

203

Nutrition Frontiers - Winter 2010  

Cancer.gov

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

204

When hot water freezes before cold  

E-print Network

I suggest that the origin of the Mpemba effect (the freezing of hot water before cold) is freezing-point depression by solutes, either gaseous or solid, whose solubility decreases with increasing temperature so that they are removed when water is heated. They are concentrated ahead of the freezing front by zone refining in water that has not been heated, reduce the temperature of the freezing front, and thereby reduce the temperature gradient and heat flux, slowing the progress of the front. I present a simple calculation of this effect, and suggest experiments to test this hypothesis.

J. I. Katz

2006-04-27

205

Porous Pavements in Cold Climates Part 1: Design, Installation, and  

E-print Network

Porous Pavements in Cold Climates Part 1: Design, Installation, and Maintenance A Green-Graded Friction Courses (2002) 3 #12;Part I Overview 1. State of the Practice 2. Common Design and Installation Cold climate performance is strong Winter maintenance has tremendous potential salt reduction Design

206

Fronts, fish, and predators  

NASA Astrophysics Data System (ADS)

Ocean fronts play a key role in marine ecosystems. Fronts shape oceanic landscapes and affect every trophic level across a wide range of spatio-temporal scales, from meters to thousands of kilometers, and from days to millions of years. At some fronts, there is an elevated rate of primary production, whereas at others, plankton is aggregated by advection and by the behavior of organisms moving against gradients in temperature, salinity, light irradiance, hydrostatic pressure and other physico-chemical and biological factors. Lower trophic level organisms - phytoplankton and zooplankton - that are aggregated in sufficient densities, attract organisms from higher trophic levels, from planktivorous schooling fish to squid, large piscivorous fish, seabirds and marine mammals. Many species have critical portions of their life stages or behaviors closely associated with fronts, including spawning, feeding, ontogenetic development, migrations, and other activities cued to frontal dynamics. At different life stages, an individual species or population might be linked to different fronts. The nature and strength of associations between fronts and biota depend on numerous factors such as the physical nature and spatio-temporal scales of the front and the species and their life stages in question. In other words, fronts support many different niches and micro/macro-habitats over a wide range of spatial and temporal scales.

Belkin, Igor M.; Hunt, George L.; Hazen, Elliott L.; Zamon, Jeannette E.; Schick, Robert S.; Prieto, Rui; Brodziak, Jon; Teo, Steven L. H.; Thorne, Lesley; Bailey, Helen; Itoh, Sachihiko; Munk, Peter; Musyl, Michael K.; Willis, Jay K.; Zhang, Wuchang

2014-09-01

207

Cabbeling at thermohaline fronts  

Microsoft Academic Search

A linear model with cabbeling dynamics is developed for a nonrotating, unstratified ocean and applied to observations of three medium- to large-scale oceanic thermohaline (density balanced) fronts. The ability of the predicted cabbeling sinking and surface convergence rates to maintain a steady front against diffusion depends critically on the assumed values of horizontal and vertical eddy viscosities. There is good

Malcolm J. Bowman; Akira Okubo

1978-01-01

208

Cold response of annual Mediterranean pasture legumes  

Microsoft Academic Search

SUMMARY - In southern Europe, the trend towards low input agriculture gives new incentives to sow forages, legumes in particular, with the aim of improving natural pastures, increase the quality of animal feeding and improve soil fertility. However, growth of forage crops in these areas is seriously limited by the ability of each species to grow during cold winters. Therefore,

M. Hekneby; M. Snchez-Daz

209

Dehydration in the Winter Arctic Tropopause Region  

NASA Technical Reports Server (NTRS)

Recent work has shown that limited amounts of tropospheric air can penetrate as much as 1 km into the middleworld stratosphere during the arctic winter. This, coupled with temperatures that are cold enough to produce saturation mixing ratios of less than 5 ppmv at the tropopause, results in stratospheric cloud formation and upper tropospheric dehydration. Even though these "cold outbreaks" occupy only a small portion of the area in the arctic (1-2%), their importance is magnified by an order of magnitude because of the air flow through them. This is reinforced by evidence of progressive drying through the winter measured during SOLVE-1. The significance of this process lies in its effect on the upper tropospheric water content of the middle and high latitude tropopause region, which plays an important role in regulating the earth's radiative balance. There appears to be significant year-to-year variability in the incidence of the cold outbreaks. This work has two parts. First, we describe case studies of dehydration taken from the SOLVE and SOLVE2 aircraft sampling missions during the Arctic winters of 2000 and 2003 respectively. Trajectory based microphysical modeling is employed to examine the sensitivity of the dehydration to microphysical parameters and the nature of sub-grid scale temperature fluctuations. We then examine the year-to-year variations in potential dehydration using a trajectory climatology.

Pfister, Leonhard; Jensen, Eric; Podolske, James; Selkirk, Henry; Anderson, Bruce; Avery, Melody; Diskin. Glenn

2004-01-01

210

Impact of declining Arctic sea ice on winter snowfall  

PubMed Central

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

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

2012-01-01

211

Impact of declining Arctic sea ice on winter snowfall.  

PubMed

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

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

2012-03-13

212

Migrations of the North Atlantic Polar front during the last 300 ka: Evidence from planktic foraminiferal data  

NASA Astrophysics Data System (ADS)

The main migrations of the Polar front (PF) during the last 300 ka were identified using planktic foraminiferal census data and derived from them sea surface paleotemperature (SST) estimates in two synchronized AMK-4438 and M23414 cores recovered directly beneath the main stream of the North Atlantic Current (NAC) south of Iceland. During the summer seasons, the cold waters adjacent to the PF did not reach the studied sites. These waters occurred here only during the winter seasons of MIS 2, 6, and 8. The northern part of the study area was influenced by the arctic waters more often than its southern part. During MIS 8 and 6 isotherms in the North Atlantic had mainly the subzonal orientation, while during MIS 2-4 they had the submeridional orientation. During the interglacials, the PF was located northward and westward from the study area. During MIS 7, the front was presumably situated closer to the study area in comparison with its modern position, and the isotherms were oriented mainly subzonal. For the MIS 5e period, we observed the most distant retreat of PF from the investigated area in the western and northwestern direction in relation to the anomalous deflection of the NAC to the north-west (intensification of the Irminger current) and the predominance of the submeridional orientation of the isotherms in the study area. During MIS 1, as well as MIS 7, the isotherms in the study area had mainly the subzonal orientation.

Bashirova, L. D.; Kandiano, E. S.; Sivkov, V. V.; Bauch, H. A.

2014-11-01

213

Relativistic runaway ionization fronts.  

PubMed

We investigate the first example of self-consistent impact ionization fronts propagating at relativistic speeds and involving interacting, high-energy electrons. These fronts, which we name relativistic runaway ionization fronts, show remarkable features such as a bulk speed within less than one percent of the speed of light and the stochastic selection of high-energy electrons for further acceleration, which leads to a power-law distribution of particle energies. A simplified model explains this selection in terms of the overrun of Coulomb-scattered electrons. Appearing as the electromagnetic interaction between electrons saturates the exponential growth of a relativistic runaway electron avalanche, relativistic runaway ionization fronts may occur in conjunction with terrestrial gamma-ray flashes and thus explain recent observations of long, power-law tails in the terrestrial gamma-ray flash energy spectrum. PMID:24580462

Luque, A

2014-01-31

214

Relativistic Runaway Ionization Fronts  

NASA Astrophysics Data System (ADS)

We investigate the first example of self-consistent impact ionization fronts propagating at relativistic speeds and involving interacting, high-energy electrons. These fronts, which we name relativistic runaway ionization fronts, show remarkable features such as a bulk speed within less than one percent of the speed of light and the stochastic selection of high-energy electrons for further acceleration, which leads to a power-law distribution of particle energies. A simplified model explains this selection in terms of the overrun of Coulomb-scattered electrons. Appearing as the electromagnetic interaction between electrons saturates the exponential growth of a relativistic runaway electron avalanche, relativistic runaway ionization fronts may occur in conjunction with terrestrial gamma-ray flashes and thus explain recent observations of long, power-law tails in the terrestrial gamma-ray flash energy spectrum.

Luque, A.

2014-01-01

215

Front Matter: Volume 7090  

NASA Astrophysics Data System (ADS)

This PDF file contains the front matter associated with SPIE Proceedings Volume 7090, including the Title Page, Copyright information, Table of Contents, Introduction (if any), and the Conference Committee listing.

SPIE, Proceedings of

2008-08-01

216

The Dulles Airport Pressure Jump Detector Array for Gust Front Detection  

Microsoft Academic Search

Wind shear has long been recognized as one of the major aviation hazards in the airport environment. A principal source of dangerous wind shear is the thunderstorm gust front, a cold air outflow from the thunderstorm downdraft. The gust front is particularly hazardous not only because of the large surface wind shears associated with it, but also because of its

A. J. Bedard Jr.; W. H. Hooke; D. W. Beran

1977-01-01

217

Thermohaline Fine Structure in an Oceanographic Front from Seismic Reflection Profiling  

Microsoft Academic Search

We present acoustic images of oceanic thermohaline structure created from marine seismic reflection profiles across the major oceanographic front between the Labrador Current and the North Atlantic Current. The images show that distinct water masses can be mapped, and their internal structure imaged, using low-frequency acoustic reflections from sound speed contrasts at interfaces across which temperature changes. The warm\\/cold front

W. Steven Holbrook; Pedro Pramo; Scott Pearse; Raymond W. Schmitt

2003-01-01

218

Two cold-season derechoes in Europe  

NASA Astrophysics Data System (ADS)

In this study, we apply for the first time the definition of a derecho (Johns and Hirt, 1987) to European cold-season convective storm systems. These occurred on 18 January 2007 and 1 March 2008, respectively, and they are shown to fulfill the criteria of a derecho. Damaging winds were reported over a distance of 1500 km and locally reached F3 intensity. Synoptic analysis for the events reveal strongly forced situations that have been described for cold-season derechoes in the United States. A comparison of swaths of damaging winds, radar structures, detected lightning, cold pool development, and cloud-top temperatures indicates that both derechoes formed along cold fronts that were affected by strong quasi-geostrophic forcing. It seems that the overlap of the cold front position with the strong differential cyclonic vorticity advection at the cyclonic flank of mid-level jet streaks favoured intense convection and high winds. The movement and path width of the two derechoes seemed to be related to this overlap. The wind gust intensity that was also different for both events is discussed and could be related to the component of the mid-level winds perpendicular to the gust fronts.

Gatzen, Christoph; P?ik, Tomas; Ryva, David

2011-06-01

219

Project COLD.  

ERIC Educational Resources Information Center

Describes Project COLD (Climate, Ocean, Land, Discovery) a scientific study of the Polar Regions, a collection of 35 modules used within the framework of existing subjects: oceanography, biology, geology, meterology, geography, social science. Includes a partial list of topics and one activity (geodesic dome) from a module. (Author/SK)

Kazanjian, Wendy C.

1982-01-01

220

Common Cold  

MedlinePLUS

... en espaol] National Library of Medicine, Medline Plus Common Cold Skip Content Marketing Share this: JavaScript is disabled in your browser. To view this content, please enable JavaScript and refresh the page. Click here for instructions on how to enable JavaScript in your browser. ...

221

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

222

Radar observations of land breeze fronts.  

NASA Technical Reports Server (NTRS)

Description of a radar-observed apparent land breeze front 12 to 14 n mi off the coast of Wallops Island, Va. Accompanying meteorological data show the land breeze at the shore to be a layer of cold air less than 300 ft deep moving seaward at approximately 2 knots. The radar observations show the land breeze vertical frontal surface sloping landward at about 20 deg, with convection over the warm water increasing the layer thickness to 2000 ft near the frontal zone. The radar-observed horizontal frontal surface is a sharp scalloped line echo in the lower 1000 ft, but becomes diffuse above. As the local circulation during daylight hours changes to a sea breeze, the land breeze front recedes toward land and dissipates.

Meyer, J. H.

1971-01-01

223

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

Microsoft Academic Search

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

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

1999-01-01

224

Finding refuge during a severe winter. by Aaron K. Kuehl and Lester D. Flake  

E-print Network

to wintering pheasants. If blizzards persist and fill these dense areas of cover, pheasants may seek out available woody cover in dense shelterbelts. In the winter of 1996-97, ice storms and blizzards relentlessly cold and blizzard conditions continued into February, 10 and dead pheasants were commonly found

225

Chilling Out with Colds  

MedlinePLUS

... most common cold virus, but more than 200 viruses can cause colds. Because there are so many, ... to help you feel better. Take that, cold viruses! Continue How Kids Catch Colds Mucus (say: MYOO- ...

226

Logistic Regression Analysis of Freezing Tolerance in Winter Wheat  

Technology Transfer Automated Retrieval System (TEKTRAN)

Four winter wheat cultivars, Eltan, Froid, Kestrel, and Tiber, were cold-acclimated for five weeks and then tested for freezing tolerance in a programmable freezer. The temperature of the soil was recorded every two minutes and the freezing episode was described as five parameters: the minimum temp...

227

Winter Weather Introduction  

E-print Network

Winter Weather Management #12;Introduction · Campus Facilities Staff · Other Campus Organizations #12;Purpose · Organize and coordinate the campus response to winter weather events to maintain campus for use by 7 AM. · Response will be modified depending upon forecast and current weather conditions. #12

Taylor, Jerry

228

Winter 2014 Economics 471  

E-print Network

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

Carter, John

229

Winter and Specialty Wheat  

Technology Transfer Automated Retrieval System (TEKTRAN)

The two main commercial types of wheat are durum (Triticum durum L., 2n=4x= 28) and common (T. aestivum L, 2n=6x=42.) wheat, the latter being the more widely grown. Wheat has three growth habits, namely winter (wheats grown over the winter months that require vernalization and can withstand prolong...

230

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

231

Winter Art Education Project  

ERIC Educational Resources Information Center

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

Jokela, Timo

2007-01-01

232

Winter Math Activities  

NSDL National Science Digital Library

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

Kawas, Terry

2013-01-01

233

Taxonomy of Greater White-fronted Geese (Aves: Anatidae)  

USGS Publications Warehouse

Five subspecies of the Greater White-fronted Goose, Anser albifrons (Scopoli, 1769), have been named, all on the basis of wintering birds, and up to six subspecies have been recognized. There has been confusion over the application of some names, particularly in North America, because of lack of knowledge of the breeding ranges and type localities, and incorrect taxonomic decisions. There is one clinally varying subspecies in Eurasia, one that breeds in Greenland, and three in North America, one newly named herein.

Banks, Richard C.

2011-01-01

234

Affections of SSTa in North Atlantic and Arctic Ocean on cold air activity over the east China marginal seas  

NASA Astrophysics Data System (ADS)

Using monthly mean sea surface temperature anomaly (SSTa) in the Northern Atlantic and Arctic from 1951-2004,the reanalysis data of sea surface pressure, air temperature and geopotential height at 500 hPa, SVD analysis were done to study the relations among the SSTa's and the cold air activity over the east China marginal seas. It is found that?in boreal winter, cold air activity over the east China marginal seas can be predicted by the SSTa in the Northern Atlantic and Arctic by the Autumn?the positive SSTa in northern Atlantic and negative SSTa in regions south of Iceland and Greenland during September, October and November, can resulted to the pressure increasing over the east China marginal seas; lower sea surface temperature in the east sea of Novaya Zemlya, and higher SST in the east sea of Novaya Zemlya, northwest of Barents Sea together with lower SST in southeast of the Barents Sea during September, October and November coincides with higher sea level pressure of China east coast. The mechanism in these affections is that positive SSTa in the Northern Atlantic can make the development of bridge at the 500hPa; higher SST in north Atlantic coincides with the development of high-altitude ridge, and then the ridge extends to the north, coincides with higher Geopotential height over the area between Novaya Zemlya and Urals. The Negative vorticity advection in front of the ridge leads cold air to key areas, then affects China east coast area, and then forms surface cold anticyclone, and vice versa. Key words?Northern Atlantic; sea regions around Novaya Zemlya?SST anomaly? SVD analysis?east China marginal seas?cold air activity

Sun, Jilin; Shi, Xiaomeng; Jiao, Yan; Ye, Xinxin

2010-05-01

235

Hydrodynamic, Bottom Boundary Layer and Sedimentary Responses to Two Contrasting Winter Storms on the Low-Energy Inner Shelf of the Northern Gulf of Mexico  

NASA Astrophysics Data System (ADS)

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. The 62-day deployment, occurring between November 24, 1998 and January 25, 1999, included numerous intervals of fair weather as well as nine cold front passages. Two energetic frontal passages were characterized by distinct meteorological, hydrodynamic, bottom boundary layer, and sedimentary responses, and may be treated as end-member types on a continuum of regional winter storms. The first frontal passage, deemed a Northwest storm, was dominated by a nearby low-pressure cell, and had strong southerly pre-frontal winds (11.5 m s-1), followed by northwesterly post-frontal winds of up to 14.5 m s-1. Peaks in significant wave height of 1.83 and 1.7 m, respectively, occurred during the pre- and post-frontal phases of the storm. The wave field consisted of energetic northerly swell that gradually gave way to a southerly sea-band as the post-frontal phase progressed. Mean currents during the storm were moderate and northerly during the pre-frontal phase, but became much stronger (up to 53 cm s-1) and southeasterly during the post-frontal phase. Sediment transport was highest following the frontal passage and was directed southeasterly at a rate of 2.66 mg cm-1 s-1. The second storm, labeled a Northeast storm, had a weak pre-frontal phase, followed by an energetic post-frontal phase during which northeasterly winds of up to 15 m s-1 dominated. The storm generated moderately-high (1.34 m), short-period (4.1 s), southerly-propagating waves subsequent to the frontal passage. Mean currents were weak and northerly during the pre-frontal phase, but became strong (22 cm s-1) and southwesterly following the passage. Shear velocity was greater than 2 cm s-1 during the post-frontal phase, and sediment transport was southwesterly at 0.24 g cm-1 s-1. Clearly, cold front passages cause significant hydrodynamic and sedimentary responses on the Louisiana inner shelf, although their impact may vary considerably from storm to storm. This has a great deal of importance to continental shelves throughout the mid-latitudes, where cold fronts are a dominant atmospheric forcing mechanism during the winter.

Pepper, D. A.; Stone, G. W.

2001-05-01

236

Stories from the Front.  

ERIC Educational Resources Information Center

Shares some of the author's personal experiences from the "front line" to illustrate the potential of computer-supported learning environments. Concludes that technology, if used in conjunction with sound pedagogy, allows students to tep outside the confines of the traditional classroom and school structure and take responsibility for both their

Melnick, Blake

2002-01-01

237

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

238

1. FRONT SHOWING LOW STONE RETAINING WALL SEPARATING THE FRONT ...  

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

1. FRONT SHOWING LOW STONE RETAINING WALL SEPARATING THE FRONT YARD FROM THE MAIN PLANT 4 RESIDENTIAL STREET. VIEW TO SOUTHWEST. - Bishop Creek Hydroelectric System, Plant 4, Cottage No. 1, Bishop Creek, Bishop, Inyo County, CA

239

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

240

The relationship between body mass and survival of wintering canvasbacks  

USGS Publications Warehouse

Mass and recapture histories of 6,000 Canvasbacks (Aythya valisineria ) banded in upper Chesapeake Bay were used to test two hypotheses: (1) early-winter body mass is associated with the probability of surviving the winter, and (2) early-winter body mass is associated with annual survival probability. Results for adult males, which provided the largest data sets, presented strong evidence that birds with high relative early-winter masses had both greater overwinter and annual survival probabilities. Results of overwinter analyses necessarily are qualified by the alternative explanation of mass-dependent emigration, i.e. the possibility that lighter birds move south in response to cold weather and leave only heavy birds for recapture. Such a phenomenon remains to be documented.

Haramis, G.M.; Nichols, J.D.; Pollock, K.H.; Hines, J.E.

1986-01-01

241

American woodcock winter distribution and fidelity to wintering areas  

USGS Publications Warehouse

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

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

1990-01-01

242

Winter 2007 Practicing Medicine  

E-print Network

of tennessee HealtH science center Medicine Magazine Winter 2007 CommunicationsTeam Writing,Editing Sh New Faces News Bites News · UTHSC Receives NIH Funding · UTMG to Grow under Dr. Schwab · Working

Cui, Yan

243

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

PubMed

Small birds exhibiting marked winter improvement of cold tolerance also show elevated summit metabolic rates (maximum cold-induced metabolic rate) in winter relative to summer. However, relatively large increases in cold tolerance can occur with only minor increments of maximum cold-induced metabolic rate and geographic variation in cold tolerance is not always positively correlated with variation in maximum cold-induced metabolic rate. Thus, it is uncertain whether maximum cold-induced metabolic rate and cold tolerance are phenotypically correlated in small birds and no previous study has directly examined this relationship. I measured maximum cold-induced metabolic rate and cold tolerance (i.e., thermogenic endurance) over three winters in black-capped chickadees Poecile atricapillus, American tree sparrows Spizella arborea, and dark-eyed juncos Junco hyemalis. For raw thermogenic endurance data, residuals of maximum cold-induced metabolic rate and thermogenic endurance from mass regressions were significantly and positively correlated in juncos and tree sparrows, and their correlation approached significance for chickadees. Log10 transformation of thermogenic endurance and mass data gave similar results. These data provide the first direct evidence for a phenotypic correlation between maximum cold-induced metabolic rate and thermogenic endurance in small birds, although much of the variance in thermogenic endurance is explained by factors other than maximum cold-induced metabolic rate and the degree of correlation differs among species. Nevertheless, these data suggest that physiological adjustments producing elevated thermogenic endurance also produce elevated maximum cold-induced metabolic rate in small birds. PMID:11585259

Swanson, D L

2001-08-01

244

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

245

Physiological and transplanting performance of Quercus ilex L. (holm oak) seedlings grown in nurseries with different winter conditions  

E-print Network

Physiological and transplanting performance of Quercus ilex L. (holm oak) seedlings grown winter conditions affected cold hardiness and other functional attributes relevant for transplanting have higher stress resistance, vigour, and transplanting performance than the seedlings cultivated

Villar-Salvador, Pedro

246

Today's Front Pages  

NSDL National Science Digital Library

Readers curious about how newspapers around the nation and the world are covering events during these difficult times may find this site useful. From the Newseum, this resource provides expandable thumbnails of front pages from September 12, 2001 newspapers from around the world. The Newseum is an interactive museum devoted to journalism and sponsored by the Freedom Forum, "a nonpartisan, international foundation dedicated to free press, free speech and free spirit for all people" (see the January 14, 2000 Scout Report).

247

Nuclear Winter: The implications for civil defense  

SciTech Connect

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

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

1987-01-01

248

Radiative thermal conduction fronts  

NASA Technical Reports Server (NTRS)

The discovery of the O VI interstellar absorption lines in our Galaxy by the Copernicus observatory was a turning point in our understanding of the Interstellar Medium (ISM). It implied the presence of widespread hot (approx. 10 to the 6th power K) gas in disk galaxies. The detection of highly ionized species in quasi-stellar objects' absorption spectra may be the first indirect observation of this hot phase in external disk galaxies. Previous efforts to understand extensive O VI absorption line data from our Galaxy were not very successful in locating the regions where this absorption originates. The location at interfaces between evaporating ISM clouds and hot gas was favored, but recent studies of steady-state conduction fronts in spherical clouds by Ballet, Arnaud, and Rothenflug (1986) and Bohringer and Hartquist (1987) rejected evaporative fronts as the absorption sites. Researchers report here on time-dependent nonequilibrium calculations of planar conductive fronts whose properties match well with observations, and suggest reasons for the difference between the researchers' results and the above. They included magnetic fields in additional models, not reported here, and the conclusions are not affected by their presence.

Borkowski, Kazimierz J.; Balbus, Steven A.; Fristrom, Carl C.

1990-01-01

249

Factors affecting outdoor exposure in winter: population-based study  

NASA Astrophysics Data System (ADS)

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.

Mkinen, Tiina M.; Raatikka, Veli-Pekka; Rytknen, Mika; Jokelainen, Jari; Rintamki, Hannu; Ruuhela, Reija; Nyh, Simo; Hassi, Juhani

2006-09-01

250

Cold knife cone biopsy  

MedlinePLUS

A cold knife cone biopsy (conization) is surgery to remove a sample of abnormal tissue from the cervix. The cervix is ... Cold knife cone biopsy is done to detect cervical cancer or early changes that lead to cancer. A cold ...

251

Bronchitis (Chest Cold)  

MedlinePLUS

... Antibiotic Use Respiratory Illnesses Sinus Infection Sore Throat Common Cold and Runny Nose Ear Infections Bronchitis (Chest Cold) ... Tips Appropriate Treatment Summary Cough Illness/Bronchitis The Common Cold Otitis Media Pharyngitis: Treat Only Proven GAS Online ...

252

Farmers Market Expands to Offer Products in Winter | Poster  

Cancer.gov

The 2013 National Cancer Institute (NCI) at Frederick Farmers Market regular season may have closed, but that doesnt mean customers who want fresh produce, handmade crafts, and other homemade goodies from local vendors are out of luck. Winter Markets, which began Jan. 7, will be held every other Tuesday, from 11 a.m. to 1 p.m., in front of Building 549 or in the Caf Room, depending on the weather.

253

Hierarchical wave-front sensing.  

PubMed

We present a new wave-front sensing technique for adaptive optics based on use of several wave-front sensors dedicated to the sensing of a different range of spatial frequencies. We call it a hierarchical wave-front sensor. We present the concept of a hierarchical wave-front sensor and apply it to the Shack-Hartmann sensor. We show the gain that is expected with two Shack-Hartmann sensors. We obtain a gain that increases with the size of the largest sensor, and we detail the application of hierarchical wave-front sensing to extreme adaptive optics and extremely large telescopes. PMID:15678767

Le Roux, Brice; Coyne, Julien; Ragazzoni, Roberto

2005-01-10

254

Air pollution episodes associated with East Asian winter monsoons.  

PubMed

A dozen multi-day pollution episodes occur from October to February in Hanoi, Vietnam due to prolonged anticyclonic conditions established after the northeast monsoon surges (cold surges). These winter pollution episodes (WPEs) account for most of the 24-h PM(10) exceedances and the highest concentrations of gaseous pollutants in Hanoi. In this study, WPEs were investigated using continuous air quality monitoring data and information on upper-air soundings and air mass trajectories. The 24-h pollutant concentrations are lowest during cold surges; concurrently rise thereafter reaching the highest levels toward the middle of a monsoon cycle, then decline ahead of the next cold surge. Each monsoon cycle usually proceeds through a dry phase and a humid phase as Asiatic continental cold air arrives in Hanoi through inland China then via the East China Sea. WPEs are associated with nighttime radiation temperature inversions (NRTIs) in the dry phase and subsidence temperature inversions (STIs) in the humid phase. In NRTI periods, the rush hour pollution peak is more pronounced in the evening than in the morning and the pollution level is about two times higher at night than in daytime. In STI periods, broad morning and evening traffic peaks are observed and pollution is as high at night as in daytime. The close association between pollution and winter monsoon meteorology found in this study for the winter 2003-04 may serve as a basis for advance warning of WPEs and for forecasting the 24-h pollutant concentrations. PMID:21925714

Hien, P D; Loc, P D; Dao, N V

2011-11-01

255

Model and observational analysis of the Northeast's regional winter climate and its relationship to the PNA pattern  

NASA Astrophysics Data System (ADS)

A study was performed of the winter climate in the Northeast United States and its relationship to the large-scale circulation. Temperature, radiation, precipitation, and circulation features of the La Nina winter of 1998--1999 were analyzed through observations, NCEP-NCAR Reanalysis, and model simulations by SUNYA regional climate model (RCM). The relationship between the Pacific North American (PNA) pattern and regional winter climate of the Northeast was also investigated. Ten Decembers during the 1980s and 1990s were simulated, five with the most positive and five with the most negative PNA index. RCM reproduced the key climate features of the Northeast during the winter of 1998--1999. The model's circulation closely agreed with the reanalysis, particularly in the mid- and upper-troposphere, and with surface wind observations. Spatial and temporal patterns of temperature and precipitation agreed well with observations, despite a cold bias in the boundary layer (2--3C) and dry bias in precipitation. The use of six-hourly, rather than twelve-hourly, reanalysis boundary conditions improved the diurnal cycle and increased the success at capturing fast-moving systems, such as fronts, and reproducing hourly weather variations. The relationship of the PNA pattern, and other teleconnection patterns, to the Northeast winter climate was investigated. Positive PNA pattern was associated with a stronger, southeastward shifted jet and colder, drier conditions in the Northeast, while mild surface southerlies were more frequent with negative PNA pattern. In the positive PNA simulations, there was a large air-water thermal gradient over the Great Lakes, enhancing evaporation and fluxes of sensible and latent heat. Precipitation and clouds during positive PNA pattern were less abundant across the domain, although lake-effect maxima were well defined. The PDO (Pacific Decadal Oscillation), PNA, and ENSO (El Nino/Southern Oscillation) teleconnections significantly influenced the initial date, final date, and duration of the Great Lakes' ice season. Observed snowfall in the Northeast exhibited a stronger relationship to the North Atlantic Oscillation (NAO) than PNA pattern. Frontal passages were most frequent under a negative PNA and positive NAO pattern, characterized by the jet stream centered over New York. Finally, the tracks of highly positive quasi-geostrophic potential vorticity anomalies were influenced by the modes of PNA and PDO.

Notaro, Michael

256

Expansion of a cold non-neutral plasma slab  

NASA Astrophysics Data System (ADS)

Expansion of the ion and electron fronts of a cold non-neutral plasma slab with a quasi-neutral core bounded by layers containing only ions is investigated analytically and exact solutions are obtained. It is found that on average, the plasma expansion time scales linearly with the initial inverse ion plasma frequency as well as the degree of charge imbalance, and no expansion occurs if the cold plasma slab is stationary and overall neutral. However, in both cases, there can exist prominent oscillations on the electron front.

Karimov, A. R.; Yu, M. Y.; Stenflo, L.

2014-12-01

257

A numerical investigation of severe thunderstorm gust fronts  

NASA Technical Reports Server (NTRS)

A numerical model was developed to simulate the evolution and structure of severe thunderstorm gust fronts. The model is a non-hydrostatic, fine resolution, cross-sectional primitive equation model. Two-dimensional horizontal and vertical equations of motion, the continuity equation, and the thermodynamic energy equation were utilized. It was shown that two dominant factors influencing gust front configuration are surface friction and the solenoidal field coincident with the front. It is suggested that solenoidal accelerations oppose the deceleration of surface friction. After a downdraft is initiated in the model, these opposing tendencies soon reach a balance and the gust front achieves a quasi-steady configuration. Thus, the experiments indicate that surface friction does not induce a cycle of front formation and collapse. In addition, the effect of evaporative cooling in producing a vigorous downdraft was parameterized by a local cooling function. Greater cooling in the downdraft results in a more intense gust front that exhibits stronger wind maximums and greater shears. The ambient air stability was shown to be an important factor influencing the depth of the cold outflow.

Mitchell, K. E.

1975-01-01

258

Long-term variability of cold surges in Korea  

NASA Astrophysics Data System (ADS)

Cold surge statistics have been analyzed from the 52-year (1961-2012) winter temperature data archived at Korea Meteorological Administration. Despite a significant winter warming in South Korea, there is no statistically affirmable sign of the occurrence frequency, duration and total days of cold surges to have changed in the record; there is little abatement in the frequency, duration, and total days of cold surges. Thermal advection anomalies were also derived from the NCEP/NCAR and ERA interim reanalysis datasets. Cold surges defined in terms of thermal advection anomalies do not exhibit any statistically significant change either. The increased mean and the decreased variance of thermal advection both indicate that cold advection from north has, in fact, decreased gradually in South Korea. It appears that cold surges are statistically rare enough to be affected by increased mean and decreased variance of thermal advection. Polar warming is often interpreted as weakening of jet stream and increasing southward flux of cold air. Analysis of thermal advection, on the other hand, does not show increased advection of cold air from north in South Korea.

Kim, Kwang-Yul; Lee, Seoyeon; Kim, Maeng-Ki; Cho, Chun-Ho

2014-08-01

259

Cold Atoms  

NASA Astrophysics Data System (ADS)

This chapter and the following one address collective effects of quantum particles, that is, the effects which are observed when we put together a large number of identical particles, for example, electrons, helium-4 or rubidium-85 atoms. We shall see that quantum particles can be classified into two categories, bosons and fermions, whose collective behavior is radically different. Bosons have a tendency to pile up in the same quantum state, while fermions have a tendency to avoid each other. We say that bosons and fermions obey two different quantum statistics, the Bose-Einstein and the Fermi-Dirac statistics, respectively. Temperature is a collective effect, and in Section 5.1 we shall explain the concept of absolute temperature and its relation to the average kinetic energy of molecules. We shall describe in Section 5.2 how we can cool atoms down thanks to the Doppler effect, and explain how cold atoms can be used to improve the accuracy of atomic clocks by a factor of about 100. The effects of quantum statistics are prominent at low temperatures, and atom cooling will be used to obtain Bose-Einstein condensates at low enough temperatures, when the atoms are bosons.

Bellac, Michel Le

2014-11-01

260

CYTOCHEMICAL DIFFERENCES IN KIDNEYS FROM WINTER-HIBERNATING AND AROUSED BATS (MYOTIS LUCIFUGUS), WITH PARTICULAR REFERENCE TO THE GOLGI ZONE  

Microsoft Academic Search

Kidneys from winter bats (Myotis lucifugus) were removed and fixed in cold formalin-calcium while the animals were in the following states: (a) natural hibernation; (b) arousal from hibernation for 24 hours; (c) laboratory maintained hibernation; and (d) no hibernation since the previous winter. With fixed frozen sections, the lead salt method of Wachstein and Meisel with adenosine triphosphate as substrate

ROBERT M. ROSENBAUM; ARNOLD MELMAN

1964-01-01

261

Ready.Gov for Kids: Winter Storms/Extreme Cold  

MedlinePLUS

... a few hours to a blizzard with blinding, wind-driven snow that lasts for several days. Many ... storms bring dangerously low temperatures and, sometimes, strong winds, icing, sleet, and freezing rain. One of the ...

262

Spring Staging Areas of the Greenland White-fronted Goose (Anser albifrons flavirostris) in West Greenland  

Microsoft Academic Search

The Greenland white-fronted goose (Anser albifrons flavirostris) migrates about 3000 km from wintering grounds in Ireland and Britain to breeding grounds in West Greenland (64? - 72?N). The migration route includes long flights over the ocean and over the Greenland ice cap. To obtain optimal reproduction output, it is important for the geese to build up their condition at specific

CHRISTIAN M. GLAHDER

1999-01-01

263

Factors affecting rice grain density unconsumed by white-fronted geese in relation to wheat damage  

Microsoft Academic Search

Lake Miyajimanuma, in central Hokkaido, is an important stopover site for white-fronted geese (Anser albifrons) wintering in Japan. In this area, increasing numbers of the geese are causing damage to wheat crops. The effects of several factors on the unconsumed density of food resources in rice fields, their main foraging site, were investigated with a view to propose a method

Tatsuya Amano; Katsumi Ushiyama; Go Fujita; Hiroyoshi Higuchi

2004-01-01

264

BREEDING POPULATIONS OF TULE WHITE-FRONTED GEESE IN NORTHWESTERN CANADA  

Microsoft Academic Search

HE Tule White-fronted Goose (Anser albifrons gambelli) is one of the least known of the North American wild geese. Available information has been largely limited to observations and collected specimens of wintering birds. The migrational routes are virtually uncharted and breeding areas unknown. The basis for considering gambelli to be a valid subspecies is dis- cussed by Swarth and Bryant

BOB ELCAS

265

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

266

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

267

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.

268

Winter depression and diabetes.  

PubMed

Depression is a common and often harmful disorder, which is frequently associated with the winter season. Research has shown a link between type 2 diabetes mellitus and depression. Furthermore, diabetics with depression have a higher rate of adverse outcomes. Little has been published regarding the seasonality of depression in diabetics. The case report described in this article concerns a 65-year-old woman with type 2 diabetes and a history of winter depression. Current evidence-based management options are reviewed. PMID:23089656

Ernst, Christine R

2012-12-01

269

Cold tolerance of forage legumes growing in controlled continental Mediterranean conditions  

Microsoft Academic Search

Summary - The growth of forage crops in Mediterranean areas is seriously limited by the dry summer but also by the cold winter. Potential forage species should be tested to improve the forage availability in these periods in which herbage production is limited. The objectives of this study were to compare seedling survival and viability in response to cold conditions

M. Snchez-Daz; M. Hekneby; M. C. Antoln

270

Frost resistance and biochemical changes during cold acclimation in different annual legumes  

Microsoft Academic Search

In Mediterranean areas of southern Europe growth of forages is seriously limited by the ability of each species to growth during cold winter. Therefore, the objective of this work was to prove the capacity for cold acclimation and frost resistance in four annual legumes native of Mediterranean region under laboratory conditions. Plants from subterranean clover (Trifolium subterraneum L. ssp. brachycalycinum

Marta Hekneby; M. Carmen Antoln; Manuel Snchez-Daz

2006-01-01

271

ANNUAL WINTER SCHOOLANNUAL WINTER SCHOOL Petersburg Nuclear Physics Institute  

E-print Network

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

Titov, Anatoly

272

HYPOTHERMIA Surviving the Cold  

E-print Network

), and fatigue are some of the main factors that can contribute to hypothermia. · Cold is the most common causeHYPOTHERMIA Surviving the Cold www.WorkSafebc.com #12;About the WCB Preventing on-the-job injury-HELP) toll-free in British Columbia. #12;1 Introduction Working in a cold environment ­ whether it be cold

Machel, Hans

273

Facts about the Common Cold  

MedlinePLUS

... Disease > Influenza > In-Depth-Resources Facts About the Common Cold What Is a Cold? Colds are minor infections ... for 10 to 40 percent of colds. Other common cold viruses include coronavirus and respiratory syncytial virus (RSV). ...

274

Front propagation in flipping processes  

NASA Astrophysics Data System (ADS)

We study a directed flipping process that underlies the performance of the random edge simplex algorithm. In this stochastic process, which takes place on a one-dimensional lattice whose sites may be either occupied or vacant, occupied sites become vacant at a constant rate and simultaneously cause all sites to the right to change their state. This random process exhibits rich phenomenology. First, there is a front, defined by the position of the leftmost occupied site, that propagates at a nontrivial velocity. Second, the front involves a depletion zone with an excess of vacant sites. The total excess ?k increases logarithmically, ?k sime ln k, with the distance k from the front. Third, the front exhibits ageingyoung fronts are vigorous but old fronts are sluggish. We investigate these phenomena using a quasi-static approximation, direct solutions of small systems and numerical simulations.

Antal, T.; ben-Avraham, D.; Ben-Naim, E.; Krapivsky, P. L.

2008-11-01

275

IMPROVEMENT OF VARIETAL GARLIC VIABILITY BY COLD STORAGE  

Technology Transfer Automated Retrieval System (TEKTRAN)

Garlic is a specialty horticultural crop that is usually planted in the fall and harvested in late summer. By delaying the planting until spring, high winter winds that blow away much needed mulch and irrigation operational challenges could be avoided. Cold storage trials were performed to determi...

276

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.

William C. Robertson, Ph.D.

2002-01-01

277

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

278

April 2007 Cold Wave National Oceanic and Atmospheric Administration  

E-print Network

The April 2007 Cold Wave occurred across much of the central Plains, Midwest and into the Southeast during of the event in concert with crop emergence and tree blooms. Winter wheat across the central Plains and Midwest through the Mississippi Valley and into the Southeast. A dominant ridge of high pressure, entrenched

279

Deciduous Plant Twigs in Winter  

ERIC Educational Resources Information Center

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

Clark, Eloise

1977-01-01

280

winter 2015 Health Informatics  

E-print Network

Health informatics sept. 24 142MHi216 $1,200 interoperability and Health information exchange sept. 24fall 2014/ winter 2015 Health Informatics Health Information Exchange Healthcare Analytics COntin: Health Informatics, Health Information Exchange and Healthcare Analytics. These programs are geared

California at Davis, University of

281

Winter Playscape Dreaming  

ERIC Educational Resources Information Center

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

Keeler, Rusty

2006-01-01

282

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

283

Announcement Cryptography { Winter 2001  

E-print Network

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

deYoung, Brad

284

WINTER 2014 Sustainability and  

E-print Network

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

Stephens, Graeme L.

285

GRAND RIVER Winter 2014  

E-print Network

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

Thompson, Michael

286

Winter Wilderness Travel and Camping.  

ERIC Educational Resources Information Center

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

Gilchrest, Norman

287

Lightning Protection against Winter Lightning  

Microsoft Academic Search

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

Hitoshi Sugimoto

2007-01-01

288

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

289

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. PMID:23466881

Miura, Kenji; Furumoto, Tsuyoshi

2013-01-01

290

The Physics Front  

NSDL National Science Digital Library

Richard Feynman was one of the great communicators and scholars within the field of physics, and his very accessible lectures remain the stuff of legend today. While Professor Feynman is no longer with us, physics teachers can avail themselves of the very nice resources offered at The Physics Front. Created by the American Association of Physics Teachers and the National Science Foundation, the site contains lesson plans, activities, labs, and other pedagogical tools for physics teachers. The site also is notable for its âFirst Time Physics Teachersâ section which contains a bit of information about the nature of teaching physics and how these resources might be best used in the classroom. The âActivitiesâ area of the site is a real treat, as educators can find activities by subject, which include optics, energy, momentum, and wave energy.

291

The Physics Front  

NSDL National Science Digital Library

The Physics Front is a public service provided by the American Association of Physics Teachers (AAPT), with additional sponsorship from the National Science Foundation (NSF). Here, teachers can browse physics resources by topic (such as "conceptual physics" and "AP-Calculus"), learn about lesson plans via the "Lesson Plan Central" area, and check out the latest "Featured Resource." A simple search engine on the top of the homepage can be used to find items of particular interest, and the "Browse Collection" option provides an easy-to-use route to over eighty different subtopics, such as diffraction, statics of fluids, and atomic physics. Also, visitors can create a free membership registration, which allows them to rate materials, participate in discussions, and organize resources in a "personal filing cabinet." Additionally, visitors can sign up in the "Get Involved" section to become a peer-reviewer or a forum moderator for the site.

2012-06-22

292

Identifying Lagrangian fronts with favourable fishery conditions  

NASA Astrophysics Data System (ADS)

Lagrangian fronts (LFs) in the ocean are defined as boundaries between surface waters with strongly different Lagrangian properties. They can be accurately detected in a given velocity field by computing synoptic maps for displacements of synthetic tracers and other Lagrangian indicators. We use Pacific saury catch and location data for a number of commercial fishery seasons in the region of the northwest Pacific with one of the richest fishery in the world. It is shown statistically that the saury fishing grounds with maximal catches are not randomly distributed over the region but located mainly along the sharp LFs where productive cold waters of the Oyashio Current, warmer waters of the southern branch of the Soya Current, and waters of warm-core Kuroshio rings converge. Computation of those fronts in altimetric geostrophic velocity fields both in the years with the First and Second Oyashio Intrusions shows that in spite of different oceanographic conditions LF locations may serve as good indicators of potential fishing grounds. Possible biophysical reasons for saury aggregation near sharp LFs are discussed. We propose a mechanism for effective export of nutrient rich waters based on stretching of material lines in the vicinity of hyperbolic objects in the ocean. The developed method, based on identifying LFs in any velocity fields, is quite general and may be applied to find potential fishing grounds for the other pelagic fish.

Prants, S. V.; Budyansky, M. V.; Uleysky, M. Yu.

2014-08-01

293

Social Media Plan #WinterPrep  

E-print Network

! #winter http://www.nssl.noaa.gov/education/svrwx101/winter/types/ Ice Jams Facebook Ice jams can occur downstream. http://www.floodsafety.noaa.gov/hazards.shtml Twitter Ice jams in rivers about winter safety by using #WinterPrep in your tweets! Winter Safety Winter Precipitation Ice

294

The relationship between cytokinins and the amount of nitrogen in the wintering organs of herbaceous plants  

Microsoft Academic Search

The dynamics of cytokinin content and the total protein and nonprotein forms of nitrogen in tissues of wintering organs of\\u000a clary sage Salvia sclarea L. and cinquefoil Potentilla alba L. in abnormally cold (20052006 years) and abnormally warm (20062007 years) winters in Moscow have been studied. A direct\\u000a correlation between the content of total cytokinins and the total and protein

V. V. Kondrateva; O. V. Shelepova

2010-01-01

295

Winter 20092010: A case study of an extreme Arctic Oscillation event  

Microsoft Academic Search

Winter 20092010 made headlines for extreme cold and snow in most of the major population centers of the industrialized countries of the Northern Hemisphere (NH). The major teleconnection patterns of the Northern Hemisphere, El Nio\\/Southern Oscillation (ENSO) and the Arctic Oscillation (AO) were of moderate to strong amplitude, making both potentially key players during the winter of 20092010. The dominant

Judah Cohen; James Foster; Mathew Barlow; Kazuyuki Saito; Justin Jones

2010-01-01

296

Differential expression of wheat genes during cold acclimation.  

PubMed

Overwintering crops such as winter wheat display significant increase in freezing tolerance during a period of cold acclimation (CA). To gain better understanding of molecular mechanisms of CA, it is important to unravel functions and regulations of CA-associated genes. Differential screening of a cDNA library constructed from cold acclimated crown tissue of winter wheat identified three novel CA-associated cDNA clones. Nucleotide sequence analysis showed that the clones encode a high mobility globular protein (HMGB1), a glycine-rich RNA-binding protein (TaGRP2), and a LEA D-11 dehydrin (DHN14). Accumulation of the three mRNAs during 14 days of CA was differentially regulated. In response to drought, and ABA, DHN14 mRNA rapidly accumulated while HMGB1 and TaGRP2 mRNA levels remained unchanged. The possible functions of each of these genes in cold acclimation are discussed. PMID:17649620

Christov, N K; Yoneyama, S; Shimamoto, Y; Imai, R

2007-01-01

297

Lagrangian sources of frontogenesis in the equatorial Atlantic front  

NASA Astrophysics Data System (ADS)

Estimating the processes that control the north equatorial sea surface temperature (SST)-front on the northern edge of the cold tongue in the tropical Atlantic is a key issue for understanding the dynamics of the oceanic equatorial Atlantic and the West African Monsoon. Diagnosis of the frontogenetic forcings on a realistic high-resolution simulation was used to identify the processes involved in the formation and evolution of the equatorial SST-front. The turbulent forcing associated with the mixed-layer turbulent heat flux was found to be systematically frontolytic while the dynamic forcing associated with currents was found to be frontogenetic for the equatorial SST-front. Nevertheless, the low-frequency component of the turbulent forcing was frontogenetic and initiated the SST-front which was then amplified and maintained by the leading dynamic forcing. This forcing was mainly driven by the meridional convergence of the northern South Equatorial Current (nSEC) and the Guinea Current, which points out the essential role played by the circulation in the equatorial SST-front evolution. The quasi-biweekly variability of the equatorial SST-front and its forcings were found to be more strongly coupled to the wind energy flux ( WEF) than to the surface wind stress. In fact the WEF controlled the convergence/divergence of the nSEC and Guinea Current and thus the meridional component of the leading dynamic forcing. The WEF explains the equatorial SST-front development better than the wind does because it is a coupled ocean-atmosphere process.

Giordani, Herv; Caniaux, Guy

2014-12-01

298

Instability of Magnetized Ionization Fronts Surrounding H II Regions  

NASA Astrophysics Data System (ADS)

An ionization front (IF) surrounding an H II region is a sharp interface through which a cold neutral gas makes transition to a warm ionized phase by absorbing UV photons from central massive stars. We investigate the structure and stability of a plane-parallel D-type IF threaded by parallel magnetic fields. We find that weak D-type IFs always have the post-IF magnetosonic Mach number M_{M2} ? 1. For such fronts, magnetic fields increase the maximum propagation speed of the IFs, while reducing the expansion factor by a factor of 1+1/(2?_1) compared to the unmagnetized case, with ?_1 denoting the plasma beta in the pre-IF region. IFs become unstable to distortional perturbations due to gas expansion across the fronts, exactly analogous to the Darrieus-Landau instability of ablation fronts in terrestrial flames. The growth rate of the IF instability is proportional linearly to the perturbation wavenumber as well as the upstream flow speed. The IF instability is stabilized by gas compressibility and becomes completely quenched when the front is D-critical. The instability is also stabilized by magnetic pressure when the perturbations propagate in the direction perpendicular to the fields. When the perturbations propagate in the direction parallel to the fields, on the other hand, it is magnetic tension that reduces the growth rate, completely suppressing the instability when M_{M2}^2 < 2/(?_1 - 1). When the front experiences an acceleration, the IF instability cooperates with the Rayleigh-Taylor instability to make the front more unstable.

Kim, Jeong-Gyu; Kim, Woong-Tae

2015-01-01

299

Managing coastal grazing marshes for breeding waders and over wintering geese: Is there a conflict?  

Microsoft Academic Search

The winter grazing intensities of brent geese Branta bernicla, pink-footed geese Anser brachyrhynchus, and white-fronted geese A. albifrons, and the breeding densities of lapwing Vanellus vanellus, redshank Tringa totanus and snipe Gallinago gallinago, were related to the environmental characteristics of 81 fields within an area of coastal grazing marshes on the north Norfolk coast. Those fields grazed most intensively by

J. A. Vickery; W. J. Sutherland; M. O'Brien; A. R. Watkinson; A. Yallop

1997-01-01

300

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

301

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

302

Winter weather activity  

NSDL National Science Digital Library

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

Frankovic, Whitney

2009-09-28

303

Storm Winter Activity  

NSDL National Science Digital Library

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

KateOlsen58

2009-09-28

304

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 ...

Barbieri, Mikel

2012-02-13

305

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

306

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

307

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

308

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

309

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. This

Silverthorn, Dee U.; Michael, Joel

2013-01-01

310

The Anomalous Winter of 1783-1784: Was the Laki Eruption or an Analog of the 2009-2010 Winter to Blame?  

NASA Technical Reports Server (NTRS)

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 Nino ]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.

2011-01-01

311

[The relationship between cytokines and the amount of nitrogen in the wintering organs of herbaceous plants].  

PubMed

The dynamics of cytokine content and the total protein and nonprotein forms of nitrogen in tissues of wintering organs of clary sage Salvia sclarea L. and cinquefoil Potentilla alba L. in abnormally cold (2005-2006 years) and abnormally warm (2006-2007 years) winters in Moscow have been studied. A direct correlation between the content of total cytokines and the total and protein nitrogen forms in tissues of wintering leaves and buds has been determined. A correlation link between the level of single cytokines and the protein nitrogen forms has been found. PMID:21268866

Kondrat'eva, V V; Shelepova, O V

2010-01-01

312

Winter Weather: Hypothermia  

MedlinePLUS

... Children Safe From Drowning in Flooded Areas Avoiding Carbon Monoxide Poisoning During a Power Outage Driving Through Water After a Disaster Preventing Trench Foot or Immersion Foot Identification and Treatment of Hypothermia Related to Exposure While Working in Cold Water General Information about ...

313

Winter Weather: Frostbite  

MedlinePLUS

... Children Safe From Drowning in Flooded Areas Avoiding Carbon Monoxide Poisoning During a Power Outage Driving Through Water After a Disaster Preventing Trench Foot or Immersion Foot Identification and Treatment of Hypothermia Related to Exposure While Working in Cold Water General Information about ...

314

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.

315

Vitamin C and colds  

MedlinePLUS

... popular belief that vitamin C can cure the common cold , the scientific evidence for this is conflicting. Large ... B. Vitamin C for preventing and treating the common cold. Cochrane Database Syst Rev . 2007 Jul 18;(3): ...

316

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 Matas Gulf, SMG; Nuevo Gulf, NG; and San Jos 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 Valds Pennsula). 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

317

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 -1.5C, 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.

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

2011-11-01

318

Clinical Scenario 1 Is Associated With Winter Onset of Acute Heart Failure.  

PubMed

Background:Several reports have evaluated the association between seasonal variation and acute heart failure (AHF) onset. Cold weather may induce AHF, but the clinical characteristics of patients susceptible to AHF during winter have not been established. Clinical Scenario (CS) is used in the early clinical management of AHF, so we investigated the relationship between CS classification and winter onset of AHF in Japan.Methods?and?Results:We enrolled 582 patients hospitalized for AHF and compared the frequency of AHF among the 4 seasons in each CS group to clarify the clinical characteristics of the winter onset group. Significant increase of AHF during winter was seen in CS1 (systolic blood pressure [SBP] (>140 mmHg) (P=0.01) but not in CS2 (SBP ?100 and ?140 mmHg) or CS3 (SBP <100 mmHg). CS1 patients were divided into winter and other season admission groups. In multivariate analysis, only lack of loop diuretic use was associated with winter admission of CS1 patients (odds ratio 0.562, 95% confidence interval: 0.256-0.798, P=0.006).Conclusions:Winter predominance of AHF was seen only in CS1, and lack of loop diuretic use was a risk factor for winter onset. Future studies are necessary to confirm whether loop diuretics are useful in preventing AHF with CS1 in winter. PMID:25421314

Hirai, Masayuki; Kato, Masahiko; Kinugasa, Yoshiharu; Sugihara, Shinobu; Yanagihara, Kiyotaka; Yamada, Kensaku; Watanabe, Tomomi; Yamamoto, Kazuhiro

2014-11-21

319

Coastal dynamics off Northwest Iberia during a stormy winter period  

NASA Astrophysics Data System (ADS)

The consequences of a stormy winter period (2009/2010) on the shelf and coastal dynamics off Northwest Iberia are analysed by using model results in combination with the set of available observations in the frame of the Iberian Margin Ocean Observatory (RAIA), a cross-border infrastructure among North Portugal and Galicia (Spain). During the study winter, the frequent arrival of weather fronts forced river plumes to flow along the inner shelf in a fast (>1 m s-1) jet-like structure. The buoyant current strongly influenced the outer ras, the name of the estuaries in the region, where a strong decay of surface salinity (<10.5) has been observed. Once the weather front has passed, the wind reversal forced the offshore expansion of river plumes and also the development of a winter upwelling event. Thermohaline patterns in both model and observations revealed an intrusion of warm (>15 C) and salty (>35.9) waters into the ras associated with the Iberian Poleward Current. Finally, some Lagrangian modelling experiments were performed to analyse the transport ability of the plume and the effect that could have had in the biological material trapped on it. The experiments reveal that an overall northward displacement of surface particles will be expected after several alternate wind events.

Otero, Pablo; Ruiz-Villarreal, Manuel; Garca-Garca, Luz; Gonzlez-Nuevo, Gonzalo; Cabanas, Jose Manuel

2013-01-01

320

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

PubMed Central

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

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

2012-01-01

321

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

USGS Publications Warehouse

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

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

2009-01-01

322

Ocean properties, ice-ocean interactions, and calving front morphology at two major west Greenland glaciers  

NASA Astrophysics Data System (ADS)

Warm sub-polar mode water (SPMW) has been identified as a primary driver of mass loss of marine terminating glaciers draining the Greenland Ice Sheet (GrIS) yet, the specific mechanisms by which SPMW interacts with these tidewater termini remain uncertain. We present oceanographic data from Rink Glacier (RG) and Store Glacier (SG) fjords, two major marine outlets draining the western sector of the GrIS into Baffin Bay over the contrasting melt-seasons of 2009 and 2010. Submarine melting occurs wherever ice is in direct contact with warmer water and the consistent presence of 2.8 C SPMW adjacent to both ice fronts below 400 m throughout all surveys indicates that melting is maintained by a combination of molecular diffusion and large scale, weak convection, diffusional (hereafter called ubiquitous) melting. At shallower depths (50-200 m), cold, brine-enriched water (BEW) formed over winter appears to persist into the summer thereby buffering this melt by thermal insulation. Our surveys reveal four main modes of glacier-ocean interaction, governed by water depth and the rate of glacier runoff water (GRW) injected into the fjord. Deeper than 200 m, submarine melt is the only process observed, regardless of the intensity of GRW or the depth of injection. However, between the surface and 200 m depth, three further distinct modes are observed governed by the GRW discharge. When GRW is weak (?1000 m3 s-1), upward motion of the water adjacent to the glacier front is subdued, weak forced or free convection plus diffusional submarine melting dominates at depth, and seaward outflow of melt water occurs from the glacier toe to the base of the insulating BEW. During medium intensity GRW (?1500 m3 s-1), mixing with SPMW yields deep mixed runoff water (DMRW), which rises as a buoyant plume and intensifies local submarine melting (enhanced buoyancy-driven melting). In this case, DMRW typically attains hydrostatic equilibrium and flows seaward at an intermediate depth of ?50-150 m, taking the BEW with it. Strong GRW (? 2000 m3 s-1) yields vigorous, buoyant DMRW, which has sufficient vertical momentum to break the sea surface before sinking and flowing seaward, thereby leaving much of the BEW largely intact. Whilst these modes of glacier-ocean interaction significantly affect the ice-ocean interaction in the upper water column (0-200 m), below 200 m both RG and SG are dominated by the weak forced convection/diffusional (herein termed ubiquitous) melting due to the presence of SPMW.

Chauch, N.; Hubbard, A.; Gascard, J.-C.; Box, J. E.; Bates, R.; Koppes, M.; Sole, A.; Patton, H.

2013-11-01

323

Winter Frost and Fog  

NASA Technical Reports Server (NTRS)

This somewhat oblique blue wide angle Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows the 174 km (108 mi) diameter crater, Terby, and its vicinity in December 2004. Located north of Hellas, this region can be covered with seasonal frost and ground-hugging fog, even in the afternoon, despite being north of 30oS. The subtle, wavy pattern is a manifestation of fog.

Location near: 28oS, 286oW Illumination from: upper left Season: Southern Winter

2005-01-01

324

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

325

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

326

Ensemble Applications in Winter  

NSDL National Science Digital Library

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

COMET

2014-04-22

327

The ABCs of Front Management  

Technology Transfer Automated Retrieval System (TEKTRAN)

Frost protection or protecting plants from cold temperatures where they could be damaged must be a major consideration in orchard planning. Cold temperature protection events commonly occur during "radiation" frost conditions when the sky is clear, there is little wind and temperature inversions ca...

328

Restless rays, steady wave fronts.  

PubMed

Observations of underwater acoustic fields with vertical line arrays and numerical simulations of long-range sound propagation in an ocean perturbed by internal gravity waves indicate that acoustic wave fronts are much more stable than the rays comprising these wave fronts. This paper provides a theoretical explanation of the phenomenon of wave front stability in a medium with weak sound-speed perturbations. It is shown analytically that at propagation ranges that are large compared to the correlation length of the sound-speed perturbations but smaller than ranges at which ray chaos develops, end points of rays launched from a point source and having a given travel time are scattered primarily along the wave front corresponding to the same travel time in the unperturbed environment. The ratio of root mean square displacements of the ray end points along and across the unperturbed wave front increases with range as the ratio of ray length to correlation length of environmental perturbations. An intuitive physical explanation of the theoretical results is proposed. The relative stability of wave fronts compared to rays is shown to follow from Fermat's principle and dimensional considerations. PMID:18247745

Godin, Oleg A

2007-12-01

329

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.

330

Intraseasonal Cold Air Outbreak over East Asia and the preceding atmospheric condition over the Barents-Kara Sea  

NASA Astrophysics Data System (ADS)

Frequent occurrence of cold air outbreak is a dominant feature of the East Asian winter monsoon. A contributing factor for the this cold air outbreak is the role of stationary Rossby waves over the Eurasian continent which intensifies the surface Siberian High and the accompanying cold air outflow. Reduced sea ice and increase in turbulence heat flux is hypothesized as a source of such stationary waves (Honda et al. 2009). In particular, the winter of 2009/2010 saw a strong correlation of high pressure anomaly over the Barents/Kara sea and the following cold air buildup over the Eurasian continent and its advection towards East Asia (Hori et al. 2011). The lag correlation of surface temperature over Japan and the 850hPa geopotential height shows a cyclonic anomaly appearing over the Barents/Kara sea which creates a cold air advection over the Eurasian continent. The pressure anomaly subsequently shifted westward to mature into a blocking high which created a wave- train pattern downstream advecting the cold air buildup eastward toward East Asia and Japan (Fig1). We further examine this mechanism for other years including the 2005/2006, 2010/2011 winter and other winters with extreme cold air outbreaks. Overall, the existence of an anticyclonic anomaly over the Barents/Kara sea correlated well with the seasonal dominance of cold air over the Eurasian continent thereby creating a contrast of a warm Arctic and cold Eurasian continent.In the intraseasonal timescale, the existence of this anticyclone corresponds to a persisting atmospheric blocking in the high latitudes. In the presentation, we address the underlying chain of events leading up to a strong cold air outbreak over East Asia from an atmosphere - sea ice - land surafce interaction point of view for paritular cold winter years.

Hori, M. E.; Inoue, J.

2011-12-01

331

[The aerobic bacterial intestinal flora of various wintering geese species].  

PubMed

The aerobic fecal flora of wintering Brent Goos (Branta bernicla), Barnacle Goose (Branta leucopsis), Greylag Goose (Anser anser), White-fronted Goose (Anser albifrons), Pink-footed Goose (Anser brachyrhynchus), and Bean Goose (Anser fabalis) was studied. There were no specific differences between the various geese. Bacterial counts were in the range of 10(5)-10(7) CPU per gram of feces. Neither pathogenic bacteria nor rotavirus could be detected in the fecal samples of the wintering geese, so that a contamination of the environment with those pathogenic organisms could be excluded. The majority of the isolated bacteria belonged to the genera Bacillus and Pseudomonas; enterobacteria and streptococci were less common. The observations are discussed regarding their epidemiological and ecological significance. PMID:7136353

Hollnder, R

1982-07-01

332

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

PubMed

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

Straume, Aksel; Johnsson, Anders; Oftedal, Gunnhild

2008-01-01

333

Dual fronts in a phase field model  

Microsoft Academic Search

We study a dual front behavior observed in a reactiondiffusion system arising initially in the context of phase field models. A precursor front propagates into a stable phase, generating a metastable intermediate phase. This intermediate phase then decays via an oscillating front, producing a periodic structure which later coarsens. Unlike previously studied models in which dual fronts appear, the appearance

Karl Glasner; Robert Almgren

2000-01-01

334

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

335

UARS Microwave Limb Sounder observations of dentrification and ozone loss in the 2000 Arctic late winter  

NASA Technical Reports Server (NTRS)

The UARS Microwave Limb Sounder obtained measurements of CIO, HNO3, and O-3 inside the Arctic lower stratospheric vortex during two intervals in February and March 2000. The data show evidence of significant chemical processing in February, consistent with the exceptionally cold conditions that prevailed earlier in the winter.

Santee, M. L.; Manney, G. L.; Livesey, N. J.; Waters, J. W.

2000-01-01

336

Winter Hydrological and Erosion Processes in the U. S. Palouse Region: Field Experimentation and WEPP Simulation  

Technology Transfer Automated Retrieval System (TEKTRAN)

Soil erosion by water is detrimental to soil fertility and crop yield as well as the environment. For cold areas, knowledge of winter hydrological processes is critical to determining alternative land-use and management practices for reducing soil loss and protecting land and water resources. Adequa...

337

A NEW MODEL TO ESTIMATE DAILY ENERGY EXPENDITURE FOR WINTERING WATERFOWL  

EPA Science Inventory

Activity budgets of wintering waterfowl have been widely used to assess habitat quality. However, when factors such as prey abundance or protection from exposure to cold or wind determine quality, measures of daily energy expenditure (DEE) may be more appropriate for this purpos...

338

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

339

TIM-3 Busy Signals Flow Front Panel  

E-print Network

TIM-3 Busy Signals Flow FPGA2 Front Panel Busy Input (NIM) LK6 PL41 LK4 LK1 PL167 TIMOUTEN Front (NIM) Front Panel IDC TIM Busy (ECL) Front-panel RODBusy LED Front-panel ROD-Busy Output (NIMRunMode EnExtRodBusy Burst Busy SARBdisable NIMEXTBUSY enRBbusy enVBbusy enXRBbusy TIM_TRIG TTC_L1A L1A XRB

University College London

340

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.

341

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 ?15.3C during summer to ?26.3C 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 ?15C, 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). PMID:23613923

Rozsypal, Jan; Kotl, Vladimr; Zahradn?kov, Helena; imek, Petr

2013-01-01

342

Crystallization and saturation front propagation in silicic magma chambers  

NASA Astrophysics Data System (ADS)

The cooling and crystallization style of silicic magma bodies in the upper crust falls on a continuum between whole-chamber processes of convection, crystal settling, and cumulate formation and interface-driven processes of conduction and crystallization front migration. In the end-member case of vigorous convection and crystal settling, volatile saturation advances downward from the roof and upward from the floor throughout the chamber. In the end-member case of stagnant magma bodies, volatile saturation occurs along an inward propagating front from all sides of the chamber. Ambient thermal gradient primarily controls the propagation rate; warm (?40 C/km) geothermal gradients lead to thick (1200+ m) crystal mush zones and slow crystallization front propagation. Cold (<40 C/km) geothermal gradients lead to rapid crystallization front propagation and thin (<1000 m) mush zones. Magma chamber geometry also exerts a first-order control on propagation rates; bodies with high surface to magma volume ratio and large Earth-surface-parallel faces exhibit more rapid propagation and thinner mush zones. Crystallization front propagation occurs at speeds of greater than 10 cm/yr (rhyolitic magma; 1 km thick sill geometry in a 20 C/km geotherm), far faster than diffusion of volatiles in magma and faster than bubbles can nucleate, grow, and ascend through the chamber. Numerical simulations indicate saturation front propagation is determined primarily by pressure and magma crystallization rate; above certain initial water contents (4.4 wt.% in a dacite) the mobile magma is volatile-rich enough above 10 km depth to always contains a saturation front. Saturation fronts propagate down from the magma chamber roof at lower water contents (3.3 wt.% in a dacite at 5 km depth), creating an upper saturated interface for most common (4-6 wt.%) magma water contents. This upper interface promotes the production of a fluid pocket underneath the apex of the magma chamber. If the fluid pocket grew faster than rates of escape into the wall rock, fluid accumulation and hydro-fracturing could possibly trigger an eruption.

Lake, Ethan T.

2013-12-01

343

Cold Weather Entomology.  

ERIC Educational Resources Information Center

Suggests instructional strategies and student activities related to the study of insects during the winter. Includes possible collecting sites and classroom activities once the insects have been collected. (JN)

McLure, John W.

1983-01-01

344

Cold stress and the cold pressor test.  

PubMed

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. This activity is easily adapted to an inquiry format that asks students to go to the scientific literature to learn about the test and then design a protocol for carrying out the test in classmates. The data collected are ideal for teaching graphical presentation of data and statistical analysis. PMID:23471256

Silverthorn, Dee U; Michael, Joel

2013-03-01

345

Lagrangian fronts in the ocean  

NASA Astrophysics Data System (ADS)

We introduce the concept of Lagrangian fronts (LFs) in the ocean and describe their importance for analyzing water mixing and transport and the specific features and differences from hydrological fronts. A method of calculating LFs in a given velocity field is proposed. Based on altimeter velocity fields from AVISO data in the northwestern Pacific, we calculate the Lagrangian synoptic maps and identify LFs of different spatial and temporal scales. Using statistical analysis of saury catches in different years according to the Goskomrybolovstvo (State Fisheries Committee of the Russian Federation), we show that LFs can serve as good indicators of places that are favorable for fishing.

Prants, S. V.; Budyansky, M. V.; Uleysky, M. Yu.

2014-05-01

346

Isolation of calcospherulites from the mineralization front of bone.  

PubMed

Calcium-containing spherical bodies (calcospherulites) exist along the mineralization front of bone and are thought to play a role in bone formation. Existing methods to isolate calcospherulites involve harsh treatments that remove much of their organic matter. This study sought to isolate them using a less destructive approach to better preserve their organic components. Juvenile rats were injected with a low dose of calcein to label the newly formed mineral at the mineralization front of bone in vivo. Periosteum was completely dissected from the tibial diaphysis and unmineralized osteoid matrix was removed by collagenase in order to expose calcospherulites. Calcein-labeled calcospherulites of approximately 0.5 mum average diameter were observed all along the mineralization front and they exhibited a Ca/P ratio of 1.3 in situ. Calcospherulites were released from the mineralization front by a short dispase digestion and isolated via fluorescence flow sorting. X-ray diffraction revealed they contained apatite crystals (c-axis length of 17.5 +/- 0.2 nm) and their Ca/P ratio was preserved during isolation. Calcospherulites treated with ice-cold ethanol exhibited a Ca/P ratio of 1.6, suggesting the presence of some extractable phospholipids. Proteins extracted from isolated calcospherulites were resolved by SDS-PAGE into more than 20 distinct bands. Western blot analyses showed the presence of matrix proteins in these preparations. These results indicate that calcospherulites can be isolated from the mineralization front of bone in a form that can be used to study their proteome and lipid composition. PMID:18765929

Midura, Ronald J; Vasanji, Amit; Su, Xiaowei; Midura, Sharon B; Gorski, Jeff P

2009-01-01

347

Role of the nocturnal coastal-front depth on cloud formation and precipitation in the Mediterranean basin  

NASA Astrophysics Data System (ADS)

Ten nocturnal coastal front events formed in the Mediterranean basin are simulated and analyzed, focusing on the coastal-front depth by using version 3.3 of the WRF-ARW mesoscale model. During the night the inland air cools faster than the air over the Mediterranean Sea. Consequently, this colder air may move offshore, forming a coastal front when interacting with the warmer and moister maritime air mass, which is lifted over the colder air. Then clouds and precipitation may occur. In this mechanism the depth of the cold air mass (H) plays an important role in theformation of clouds and precipitation. Stratiform clouds appear if H is higher than the lifting condensation level of the warm air mass. Moreover, if H is higher than the corresponding level of free convection convective clouds are formed. H is estimated from the mesoscale simulations at an hourly scale, as well as taking the average and maximum values during the whole night. Furthermore, several parameters related to trigger convection, the blockage effect that the cold air mass offers to the prevailing flow, the deceleration induced by cold front on the upstream maritime flow and the location of precipitation with respect to the front are estimated. Additionally, a forecasting cloud-band index is proposed in order to evaluate whether stratiform clouds are formed offshore in the ten simulated nocturnal coastal fronts.

Mazon, Jordi; Pino, David

2015-02-01

348

Enroll now: winter.edm.vt.edu Winter 2015 Calendar  

E-print Network

& Literatures Spanish Course Descriptions: Winter 2015 SPAN 2774: Minority Languages Examination of language policies and practices with regard to minority languages across the Spanish-speaking context, histories of minority languages in Spanish- speaking areas

Buehrer, R. Michael

349

Cold Air Damming  

NSDL National Science Digital Library

Cold Air Damming is part of the Mesoscale Meteorology Primer series. This module first presents a Navy forecast scenario prior to the development of a major cold air damming (CAD) event along the east slopes of the Appalachian Mountains. Then, from a conceptual standpoint, the classic CAD scenario is described in detail, both from an observational and modeling standpoint.

2014-09-14

350

Relationship between mitochondrial haplogroup and seasonal changes of physiological responses to cold  

PubMed Central

Background Physiological responses to cold exhibit individual variation that can be affected by various factors, such as morphological characteristics, seasonal changes, and lifestyle; however, the genetic factors associated with this variation remain unclear. Recent studies have identified mtDNA as a potential genetic factor affecting cold adaptation. In addition, non-shivering thermogenesis (NST), a process closely related to mitochondrial dynamics, has also been suggested as an important factor affecting human response to cold. The present study aimed to clarify the relationship between mitochondrial haplogroup and NST during periods of mild cold exposure. Methods Seventeen healthy university students (D: n?=?8, non-D: n?=?9) participated in the present study during summer and winter. A climate chamber was programmed so that ambient temperature inside dropped from 28C to 16C over the course of an 80-minute period. Physiological parameters were recorded throughout the course of the experiments. Results Increases in VO2 were significantly greater during periods of cold exposure in winter than they were during periods of cold exposure in summer, and individuals from the D group exhibited greater winter values of ?VO2 than individuals from the non-D group. Tre was significantly lower during periods of rest and cold exposure in winter; however, no significant difference was observed between Tre values of individuals in the D and non-D groups. In addition, although Tdist was significantly lower during periods of rest in winter than it was during those same periods in summer, no significant seasonal differences in values of Tdist were observed during periods of cold exposure. Conclusions Results of the present study indicated that NST was greater in winter, and that the D group exhibited greater NST than the non-D group during winter. Despite the differences between groups in NST, no significant differences in rectal and skin temperatures were found between groups in either season. Therefore, it was supposed that mitochondrial DNA haplogroups had a greater effect on variation in energy expenditure involving NST than they had on insulative responses. Future studies are necessary in order to investigate more multiple candidate genes related to human cold adaptation and to elucidate the relationship between gene polymorphism and physiological polytypism. PMID:25183371

2014-01-01

351

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

PubMed

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

Vzina, F; Thomas, D W

2000-01-01

352

Nutrient dynamics in the winter thermohaline frontal zone of the northern shelf region of the South China Sea  

Microsoft Academic Search

As the first attempt to estimate the nutrient transport across the winter thermohaline frontal zone on the northern shelf of the South China Sea, the nutrient dynamics around the front and the effects of cross-frontal water exchange on nutrient transport were investigated using wintertime field observations. Both water temperature and salinity increased from coastal to oceanic waters, showing the presence

Su Mei Liu; Xinyu Guo; Qi Chen; Jing Zhang; Yan Feng Bi; Xin Luo; Jian Bing Li

2010-01-01

353

Reaction front formation in contaminant plumes  

NASA Astrophysics Data System (ADS)

The formation of successive fronts in contaminated groundwater plumes by subsoil bacterial action is a commonly accepted feature of their propagation, but it is not obviously clear from a mathematical standpoint quite how such fronts are formed or propagate. In this paper we show that these can be explained by combining classical reaction-diffusion theory involving just two reactants (oxidant and reductant), and a secondary reaction in which a reactant on one side of such a front is (re-)formed on the other side of the front via diffusion of its product across the front. We give approximate asymptotic solutions for the reactant profiles, and the propagation rate of the front.

Cribbin, Laura B.; Winstanley, Henry F.; Mitchell, Sarah L.; Fowler, Andrew C.; Sander, Graham C.

2014-12-01

354

Disk instabilities and cooling fronts  

NASA Astrophysics Data System (ADS)

Accretion disk outbursts, and their subsequent decline, offer a unique opportunity to constrain the physics of angular momentum transport in hot accretion disks. Recent work has centered on the claim by Cannizzo et al. that the exponential decay of luminosity following an outburst in black hole accretion disk systems is only consistent with a particular form for the dimensionless viscosity, ?=35(cs/r?)3/2. This result can be understood in terms of a simple model of the evolution of cooling fronts in accretion disks. In particular, the cooling front speed during decline is ~?Fcs,F(cs,F/r?)n, where F denotes the position of the cooling front, and the exact value of n depends on the hot state opacity, (although generally n~1/2). Setting this speed proportional to r constrains the functional form of ? in the hot phase of the disk, which sets it apart from previous arguments based on the relative durations of outburst and quiescence. However, it remains uncertain how well we know the exponent n. In addition, more work is needed to clarify the role of irradiation in these systems and its effect on the cooling front evolution.

Vishniac, Ethan T.

1998-04-01

355

Invariant light front perturbation theory  

SciTech Connect

It is shown that with the introduction of an external lightlike vector, a light front perturbation theory for the S matrix in quantum field theory can be developed in which the individual terms in the series are invariant functions of the particle variables and the external vector. No limiting processes are involved. The dependence of the results on the external lightlike vector is discussed.

Fuda, M.G.

1987-08-01

356

Advanced RF Front End Technology  

NASA Astrophysics Data System (ADS)

The ability to achieve low-mass low-cost micro/nanospacecraft for Deep Space exploration requires extensive miniaturization of all subsystems. The front end of the Telecommunication subsystem is an area in which major mass (factor of 10) and volume (factor of 100) reduction can be achieved via the development of new silicon based micromachined technology and devices. Major components that make up the front end include single-pole and double-throw switches, diplexer, and solid state power amplifier. JPL's Center For Space Microsystems - System On A Chip (SOAC) Program has addressed the challenges of front end miniaturization (switches and diplexers). Our objectives were to develop the main components that comprise a communication front end and enable integration in a single module that we refer to as a 'cube'. In this paper we will provide the latest status of our Microelectromechanical System (MEMS) switches and surface micromachined filter development. Based on the significant progress achieved we can begin to provide guidelines of the proper system insertion for these emerging technologies. Additional information is contained in the original extended abstract.

Herman, M. I.; Valas, S.; Katehi, L. P. B.

2001-01-01

357

Turtle Skeleton - Front Limb (Flipper)  

NSDL National Science Digital Library

Turtles use their front limb (flipper) of its skeleton to propel themselves through water. It is webbed and connected to a ball and socket joint, allowing the turtle to be agile in water. Its sharp claws help the turtle to grab and defend itself. The limbs may be tucked inside the turtle's shell when it feels threatened.

Ketan Patel (California State University, Fullerton; Student, Biological Sciences)

2007-06-18

358

Turtle Skeleton - Front Limb (Claw)  

NSDL National Science Digital Library

Turtles use their front limb (flipper) of its skeleton to propel themselves through water. It is webbed and is connected to a ball and socket joint, allowing the turtle to be agile in water. Its sharp claws help the turtle to grab and defend itself.

Ketan Patel (California State University, Fullerton; Student, Biological Sciences)

2007-07-28

359

The Light-Front Vacuum  

E-print Network

Background: The vacuum in the light-front representation of quantum field theory is trivial while vacuum in the equivalent canonical representation of the same theory is non-trivial. Purpose: Understand the relation between the vacuum in light-front and canonical representations of quantum field theory and the role of zero-modes in this relation. Method: Vacuua are defined as linear functionals on an algebra of field operators. The role of the algebra in the definition of the vacuum is exploited to understand this relation. Results: The vacuum functional can be extended from the light-front Fock algebra to an algebra of local observables. The extension to the algebra of local observables is responsible for the inequivalence. The extension defines a unitary mapping between the physical representation of the local algebra and a sub-algebra of the light-front Fock algebra. Conclusion: There is a unitary mapping from the physical representation of the algebra of local observables to a sub-algebra of the light-fro...

Herrmann, Marc

2015-01-01

360

Nesting habitat of the Tule Greater White-fronted Goose Anser albifrons elgasi  

USGS Publications Warehouse

This paper presents the first information on the availability and use of nesting habitat by the rare Tule Greater White-fronted Goose Anser albifrons elgasi. The breeding range was sampled by marking geese with radio transmitters on wintering and moulting areas, and tracking them to nest sites in Alaska. Nesting habitat was described at the scales of ecoregion, wetland ecosystem (National Wetlands Inventory (NWI) maps), vegetation type within wetland (Alaska Vegetation Classification (AVC) maps based on satellite imagery), and nest site. Tule Greater White-fronted Goose nests were located in boreal forest wetlands in the upper Cook Inlet Basin ecoregion. Nesting Tule Greater White-fronted Geese selected NWT Palustrine Seasonally Flooded wetlands and used NWI Palustrine Saturated wetlands in proportion to availability. Within these wetlands, Tule Greater White-fronted Geese used Needleleaf Forest, Low Shrub and Herbaceous (mostly graminoid) AVC classes for nest sites in proportion to availability Most (93%) Tule Greater White-fronted Geese nested > 75 m from open water ponds or lakes, and many nested in wetlands with little or no open water. Tule Greater White-fronted Geese nest only in a small breeding area near the most human-impacted area of the state, and continued development may limit the use of suitable nesting habitat.

Densmore, R.V.; Ely, C.R.; Bollinger, K.S.; Kratzer, S.; Udevitz, M.S.; Fehringer, D.J.; Rothe, T.C.

2006-01-01

361

Winter fuels report  

SciTech Connect

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

Not Available

1994-10-01

362

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

363

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

364

PHYSICS 122 LABORATORY (Winter, 2014)  

E-print Network

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

Yoo, S. J. Ben

365

PHYSICS 122 LABORATORY (Winter, 2015)  

E-print Network

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

Yoo, S. J. Ben

366

Molecular characterization of a cold-induced plasma membrane protein gene from wheat  

Microsoft Academic Search

As a means to study the function of plasma membrane proteins during cold acclimation, we have isolated a cDNA clone for wpi6 which encodes a putative plasma membrane protein from cold-acclimated winter wheat. The wpi6 gene encodes a putative 5.9kDa polypeptide with two predicted membrane-spanning domains, the sequence of which shows high\\u000a sequence similarity with BLT101-family proteins from plants and

Ryozo Imai; Michiya Koike; Keita Sutoh; Akira Kawakami; Atsushi Torada; Kiyoharu Oono

2005-01-01

367

Maximizing survivorship in cold: thermogenic profiles of non-hibernating mammals  

Microsoft Academic Search

Winter-active small mammals residing in seasonal environments employ many different behavioral, anatomical and physiological\\u000a mechanisms to cope with cold. Herein we review research on survival mechanisms in cold employed by small mammals with emphasis\\u000a on the families Soricidae, Muridae and Sciuridae. The focus of this review is on research delineating the role of seasonal\\u000a changes in resting metabolic rate (RMR),

Joseph F. Merritt; David A. Zegers

2002-01-01

368

PBF Cooling Tower under construction. Cold water basin is five ...  

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

PBF Cooling Tower under construction. Cold water basin is five feet deep. Foundation and basin walls are reinforced concrete. Camera facing west. Pipe openings through wall in front are outlets for return flow of cool water to reactor building. Photographer: John Capek. Date: September 4, 1968. INEEL negative no. 68-3473 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

369

Instability of Evaporation Fronts in the Interstellar Medium  

NASA Astrophysics Data System (ADS)

The neutral component of the interstellar medium is segregated into the cold neutral medium (CNM) and warm neutral medium (WNM) as a result of thermal instability. It was found that a plane-parallel CNM-WNM evaporation interface, across which the CNM undergoes thermal expansion, is linearly unstable to corrugational disturbances, in complete analogy with the Darrieus-Landau instability (DLI) of terrestrial flames. We perform a full linear stability analysis as well as nonlinear hydrodynamic simulations of the DLI of such evaporation fronts in the presence of thermal conduction. We find that the DLI is suppressed at short length scales by conduction. The length and time scales of the fastest growing mode are inversely proportional to the evaporation flow speed of the CNM and its square, respectively. In the nonlinear stage, the DLI saturates to a steady state where the front deforms to a finger-like shape protruding toward the WNM, without generating turbulence. The evaporation rate at nonlinear saturation is larger than the initial plane-parallel value by a factor of ~2.4 when the equilibrium thermal pressure is 1800 k B cm-3 K. The degrees of front deformation and evaporation-rate enhancement at nonlinear saturation are determined primarily by the density ratio between the CNM and WNM. We demonstrate that the Field length in the thermally unstable medium should be resolved by at least four grid points to obtain reliable numerical outcomes involving thermal instability.

Kim, Jeong-Gyu; Kim, Woong-Tae

2013-12-01

370

Thermohaline fine structure in an oceanographic front from seismic reflection profiling.  

PubMed

We present acoustic images of oceanic thermohaline structure created from marine seismic reflection profiles across the major oceanographic front between the Labrador Current and the North Atlantic Current. The images show that distinct water masses can be mapped, and their internal structure imaged, using low-frequency acoustic reflections from sound speed contrasts at interfaces across which temperature changes. The warm/cold front is characterized by east-dipping reflections generated by thermohaline intrusions in the uppermost 1000 meters of the ocean. Our results imply that marine seismic reflection techniques can provide excellent spatial resolution of important oceanic phenomena, including thermohaline intrusions, internal waves, and eddies. PMID:12907798

Holbrook, W Steven; Pramo, Pedro; Pearse, Scott; Schmitt, Raymond W

2003-08-01

371

Subjective symptoms among female workers and winter working conditions in a consumer cooperative.  

PubMed

Subjective musculoskeletal symptoms are more frequently complained about in cold store work and in related conditions than in normal temperature work. This cross sectional study was undertaken (a) to explore the prevalence of subjective symptoms in winter among a group of female workers engaged in classification of cold storage goods, and in a group of female checkers in several supermarkets of a large consumer cooperative; and (b) to give recommendations for improving the winter working conditions of these workers. The subjects consisted of 46 workers engaged in classification of cold storage goods, 56 checkers operating a laser scanner in supermarkets and 59 office workers (control group). Work loads for the three groups were estimated according to the recommended criteria. A self-administered questionnaire covering age, occupational career, smoking, alcohol drinking and physical exercise, present or past history of diseases, individual protective measures against cold, and subjective symptoms (54 items) was used. The air temperature of the working site at the opening time for classification workers was 4.8 degrees C which was significantly lower than those measured for the other two work places (12.1 degrees C and 15.8 degrees C). About 70 to 80% of classification workers complained of cold sensation in different body regions, as well as shoulder stiffness, and problems related to the back. The supermarket checkers and office workers had a high prevalence of cold sensation in their feet. The frequencies of using warm clothes and foot heaters, as an individual measure to work comfortably in winter among the classification workers and the checkers were significantly higher than that among the office workers. We concluded that work difficulty due to moderate cold exposure among workers in the consumer cooperative could be reduced by some physical activity as well as proper clothes. PMID:16230841

Inaba, Ryoichi; Mirbod, Seyed Mohammad; Kurokawa, Junichi; Inoue, Masato; Iwata, Hirotoshi

2005-09-01

372

Is the Gulf Stream responsible for Europe's mild winters?  

NASA Astrophysics Data System (ADS)

Is the transport of heat northward by the Gulf Stream and North Atlantic Drift, and its subsequent release into the midlatitude westerlies, the reason why Europe's winters are so much milder than those of eastern North America and other places at the same latitude? Here, it is shown that the principal cause of this temperature difference is advection by the mean winds. South-westerlies bring warm maritime air into Europe and north-westerlies bring frigid continental air into north-eastern North America. Further, analysis of the ocean surface heat budget shows that the majority of the heat released during winter from the ocean to the atmosphere is accounted for by the seasonal release of heat previously absorbed and not by ocean heat-flux convergence. Therefore, the existence of the winter temperature contrast between western Europe and eastern North America does not require a dynamical ocean. Two experiments with an atmospheric general-circulation model coupled to an ocean mixed layer confirm this conclusion. The difference in winter temperatures across the North Atlantic, and the difference between western Europe and western North America, is essentially the same in these models whether or not the movement of heat by the ocean is accounted for. In an additional experiment with no mountains, the flow across the ocean is more zonal, western Europe is cooled, the trough east of the Rockies is weakened and the cold of north-eastern North America is ameliorated. In all experiments the west coast of Europe is warmer than the west coast of North America at the same latitude whether or not ocean heat transport is accounted for. In summary the deviations from zonal symmetry of winter temperatures in the northern hemisphere are fundamentally caused by the atmospheric circulation interacting with the oceanic mixed layer.

Seager, R.; Battisti, D. S.; Yin, J.; Gordon, N.; Naik, N.; Clement, A. C.; Cane, M. A.

2002-10-01

373

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

374

Negative velocity fluctuations of pulled reaction fronts.  

PubMed

The position of a reaction front, propagating into an unstable state, fluctuates because of the shot noise. What is the probability that the fluctuating front moves considerably slower than its deterministic counterpart? Can the noise arrest the front motion for some time, or even make it move in the wrong direction? We present a WKB theory that assumes many particles in the front region and answers these questions for the microscopic model A?2A and random walk. PMID:22060316

Meerson, Baruch; Sasorov, Pavel V

2011-09-01

375

Negative velocity fluctuations of pulled reaction fronts  

NASA Astrophysics Data System (ADS)

The position of a reaction front, propagating into an unstable state, fluctuates because of the shot noise. What is the probability that the fluctuating front moves considerably slower than its deterministic counterpart? Can the noise arrest the front motion for some time, or even make it move in the wrong direction? We present a WKB theory that assumes many particles in the front region and answers these questions for the microscopic model A?2A and random walk.

Meerson, Baruch; Sasorov, Pavel V.

2011-09-01

376

The History of Winter: teachers as scientists  

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

377

Arctic winter 2009/2010 and 2010/2011 in comparison: Denitrification and polar stratospheric cloud formation  

NASA Astrophysics Data System (ADS)

Polar Stratospheric Clouds (PSCs) and denitrification, the permanent removal of nitric acid (HNO3) by sedimenting HNO3 containing PSC particles, play a key role in stratospheric ozone depletion. The two recent Arctic winter 2009/2010 and 2010/2011 were both quite unique. The Arctic winter 2010/2011 was one of the coldest winter on record leading to the strongest depletion of ozone ever measured. Though the Arctic winter 2009/2010 was rather warm in the climatological sense it was distuinguished by a exceptionally cold stratosphere from mid December 2009 to mid January 2010 leading to prolonged PSC formation and strong denitrification. For investigating PSC formation during these two Arctic winter we apply ground-based measurements performed with the Esrange and the IRF lidar in the area of Kiruna, Northern Sweden (69 N 21 E) and space-borne lidar measurements from the CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) Satellite together with microphysical box model simulations. To investigate denitrification during these two Arctic winter we apply measurements from the Odin Sub-Millimetre Radiometer (Odin/SMR) as well as measurements from the Microwave Limb Sounder on Aura (Aura/MLS). Though denitrification in 2009/2010 was until then the strongest in the entire Odin/SMR measurement period it was excelled by the 2010/2011 winter where denitrification was nearly as severe as in the Antarctic. PSC occurrance during both winter was also quite different. While PSCs were present during the Arctic winter 2010/2011 over nearly four months, from mid December to end of March, they were not as persistent as the ones that occurred during the shorter (one month) cold period during the Arctic winter 2009/2010.

Khosrawi, F.; Urban, J.; Pitts, M. C.; Voelger, P.; Achtert, P.; Santee, M. L.; Manney, G. L.; Murtagh, D.

2012-04-01

378

Pain modulation during drives through cold and hot virtual environments.  

PubMed

Evidence exists that virtual worlds reduce pain perception by providing distraction. However, there is no experimental study to show that the type of world used in virtual reality (VR) distraction influences pain perception. Therefore, we investigated whether pain triggered by heat or cold stimuli is modulated by "warm "or "cold " virtual environments and whether virtual worlds reduce pain perception more than does static picture presentation. We expected that cold worlds would reduce pain perception from heat stimuli, while warm environments would reduce pain perception from cold stimuli. Additionally, both virtual worlds should reduce pain perception in general. Heat and cold pain stimuli thresholds were assessed outside VR in 48 volunteers in a balanced crossover design. Participants completed three 4-minute assessment periods: virtual "walks " through (1) a winter and (2) an autumn landscape and static exposure to (3) a neutral landscape. During each period, five heat stimuli or three cold stimuli were delivered via a thermode on the participant's arm, and affective and sensory pain perceptions were rated. Then the thermode was changed to the other arm, and the procedure was repeated with the opposite pain stimuli (heat or cold). We found that both warm and cold virtual environments reduced pain intensity and unpleasantness for heat and cold pain stimuli when compared to the control condition. Since participants wore a head-mounted display (HMD) in both the control condition and VR, we concluded that the distracting value of virtual environments is not explained solely by excluding perception of the real world. Although VR reduced pain unpleasantness, we found no difference in efficacy between the types of virtual world used for each pain stimulus. PMID:17711359

Mhlberger, Andreas; Wieser, Matthias J; Kenntner-Mabiala, Ramona; Pauli, Paul; Wiederhold, Brenda K

2007-08-01

379

Global transcriptome profiles of Camellia sinensis during cold acclimation  

PubMed Central

Background Tea is the most popular non-alcoholic health beverage in the world. The tea plant (Camellia sinensis (L.) O. Kuntze) needs to undergo a cold acclimation process to enhance its freezing tolerance in winter. Changes that occur at the molecular level in response to low temperatures are poorly understood in tea plants. To elucidate the molecular mechanisms of cold acclimation, we employed RNA-Seq and digital gene expression (DGE) technologies to the study of genome-wide expression profiles during cold acclimation in tea plants. Results Using the Illumina sequencing platform, we obtained approximately 57.35 million RNA-Seq reads. These reads were assembled into 216,831 transcripts, with an average length of 356 bp and an N50 of 529 bp. In total, 1,770 differentially expressed transcripts were identified, of which 1,168 were up-regulated and 602 down-regulated. These include a group of cold sensor or signal transduction genes, cold-responsive transcription factor genes, plasma membrane stabilization related genes, osmosensing-responsive genes, and detoxification enzyme genes. DGE and quantitative RT-PCR analysis further confirmed the results from RNA-Seq analysis. Pathway analysis indicated that the carbohydrate metabolism pathway and the calcium signaling pathway might play a vital role in tea plants responses to cold stress. Conclusions Our study presents a global survey of transcriptome profiles of tea plants in response to low, non-freezing temperatures and yields insights into the molecular mechanisms of tea plants during the cold acclimation process. It could also serve as a valuable resource for relevant research on cold-tolerance and help to explore the cold-related genes in improving the understanding of low-temperature tolerance and plant-environment interactions. PMID:23799877

2013-01-01

380

What drives the Azores Front dynamics?  

Microsoft Academic Search

The Azores Front is the northern boundary of the subtropical Gyre in the northeast Atlantic Ocean. This permanent thermohaline front forms a natural barrier between oligotrophic waters in the south and waters originating in the temperate North Atlantic. It is changing its position and thickness continuously because of a strong tendency to meandering. To locate the front CTD, XBT and

A. Bauer; J. J. Waniek; D. Schulz-Bull

2008-01-01

381

Could Behaviour and Not Physiological Thermal Tolerance Determine Winter Survival of Aphids in Cereal Fields?  

PubMed Central

Traits of physiological thermotolerance are commonly measured in the laboratory as predictors of the field success of ectotherms at unfavourable temperatures (e.g. during harsh winters, heatwaves, or under conditions of predicted global warming). Due to being more complicated to measure, behavioural thermoregulation is less commonly studied, although both physiology and behaviour interact to explain the survival of ectotherms. The aphids Metopolophium dirhodum, Rhopalosiphum padi and Sitobion avenae are commercially important pests of temperate cereal crops. Although coexisting, these species markedly differ in winter success, with R. padi being the most abundant species during cold winters, followed by S. avenae and lastly M. dirhodum. To better understand the thermal physiology and behavioural factors contributing to differential winter success, the lethal temperature (physiological thermotolerance) and the behaviour of aphids in a declining temperature regime (behavioural thermotolerance) of these three species were investigated. Physiological thermotolerance significantly differed between the three species, with R. padi consistently the least cold tolerant and S. avenae the most cold tolerant. However, although the least cold tolerant of the study species, significantly more R. padi remained attached to the host plant at extreme sub-zero temperatures than S. avenae and M. dirhodum. Given the success of anholocyclic R. padi in harsh winters compared to its anholocyclic counterparts, this study illustrates that behavioural differences could be more important than physiological thermotolerance in explaining resistance to extreme temperatures. Furthermore it highlights that there is a danger to studying physiological thermotolerance in isolation when ascertaining risks of ectotherm invasions, the establishment potential of exotic species in glasshouses, or predicting species impacts under climate change scenarios. PMID:25490555

Alford, Lucy; Andrade, Thiago Oliveira; Georges, Romain; Burel, Franoise; van Baaren, Joan

2014-01-01

382

Coping with Colds  

MedlinePLUS

... by viruses called rhinoviruses that are in invisible droplets in the air you breathe or on things ... Continue Catching Colds Rhinoviruses can stay alive as droplets in the air or on surfaces for as ...

383

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

384

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

385

Teaching in a Cold Environment.  

ERIC Educational Resources Information Center

Designed to help teachers deal with students in a cold environment, this article explains cold physiology and fundamental laws of heat; describes 14 common cold injuries and their current treatment; and lists a number of useful teaching techniques for cold environments. (SB)

Ewert, Alan

1979-01-01

386

Teaching in a Cold Environment.  

ERIC Educational Resources Information Center

Instructors who teach outdoors in an environment so cold as to cause injury must satisfy program objectives while avoiding cold injury to themselves and students, help students focus on learning instead of discomfort, and alleviate some students' intense fear of the cold. Dealing with the cold successfully requires a thorough knowledge of:

Ewert, Alan

387

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

388

COLD WEATHER PLUME STUDY  

EPA Science Inventory

While many studies of power plant plume transport and transformation have been performed during the summer, few studies of these processes during the winter have been carried out. Accordingly, the U.S. Environmental Protection Agency and the Electric Power Research Institute join...

389

Evaporation fronts in porous media  

NASA Astrophysics Data System (ADS)

Experimental and computational studies have been conducted to model the propagation of evaporating fronts through porous media. The results from the experiments are compared with a numerical model and the results agree qualitatively with the temperature distribution in the vapor and liquid regions obtained from the numerical solution. The condition for which a two-phase zone does not exist due to high heat flux is also examined. Results also confirm earlier analysis of the front stability. In this thesis an implicit finite difference scheme is utilized to simulate the propagation of an evaporating front in a porous medium saturated with water and undergoing the phase change process. The following three numerical models are developed: (1) a one-equation model that assumes local thermal equilibrium; (2) a two-equation model that utilizes the lumped capacitance assumption to predict the heat transfer to the solid phase; and (3) a two-equation model that utilizes a more precise quasi-analytical approach to more accurately characterize the conduction in the solid phase. Results illustrate that the one-equation model does not yield accurate results when the thermophysical properties characterized by the volume weighted ratio of thermal diffusivities, C, is greater than 10 (within 5% error). Hence a two-equation model is necessary depending on the level of accuracy desired. In addition, consistent with the established "rule of thumb", for Biot number, Biv, is less than 0.1, the traditional two-equation model which makes the lumped capacitance assumption for the solid phase compares well with a two-equation model that more accurately predicts the time dependent diffusion in the solid phase using Duhamel's theorem. High intensity drying is used to characterize those situations for which the drying medium is sufficiently above the saturation temperature of water to preclude the existence of a two-phase zone. High intensity drying is modeled numerically and the relationship between pressure, the drying conditions and material properties is examined since elevated pressure that can occur during high intensity drying is potentially destructive. A quasi two-dimensional numerical model of high intensity drying with specific application to underground coal gasification is presented. The anisotropy due to permeability of coal is considered and the results illustrate that a decrease in permeability, K (10-14 to 10-12 m2), results in faster front propagation. Front propagation for the same thick coal seam at two different depths indicated that it is faster when the depth increases. It was also found that as the thickness of coal seam decreases the front propagates faster. Decreasing the pressure or increasing the temperature in the cavity results in a faster front propagation. Groundwater contamination can be a potential problem when the pressure and temperature in the cavity are lowered.

Pakala, Venkata Krishna Chaitanya

390

48 Los Alamos Science Number 24 1996 In the midst of a cold Russian  

E-print Network

48 Los Alamos Science Number 24 1996 In the midst of a cold Russian winter, these Russian met any of Number 24 1996 Los Alamos Science 49 Lab-to-Lab Scientific Collaborations Between Los-related scientific experiment to be carried out on U.S. soil. The experiment, performed by Russian nuclear

391

Environmental Regulation of a 25 kDa Dehydrin in Relation to Rhododendron Cold Acclimation  

Microsoft Academic Search

The influence of photoperiod and temperature on the seasonal (fall to winter) cold acclimation and accu- mulation of a 25 kDa dehydrin in Rhododendron 'Chionoides? was studied by exposing two groups of plants each in the greenhouse or outdoors to either a natural photoperiod (or short days) or an extended photoperiod (or long days) regime. Results suggest that the shortening

Calin O. Marian; Atilla Eris; Stephen L. Krebs; Rajeev Arora

2004-01-01

392

Winter Snowfall Turns an Emerald White  

NASA Technical Reports Server (NTRS)

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

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

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

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

2001-01-01

393

The Dallas winter visibility study  

SciTech Connect

For some years, a highly visible cloud of polluted air could be seen over the city during winter season stagnation conditions. A historical study of visual range data collected from local airports conducted by the Texas Air Control Board showed a decreasing trend in the number of good visibility days per year over the past 35 years and, that the average visibility has decreased by 50 percent since 1940. Specific data describing the haze composition or source contributions to the winter pollution haze were limited. The purpose of this study, was to determine the composition of the visible haze, and from that information, determine the relative contribution of the various air pollution sources in the Dallas area to winter visibility impairment. Two existing air quality monitoring stations were augmented with additional instrumentation for this study. 18 figs., 18 tabs.

Einfeld, W.; Dattner, S.; Zimmermann, K.

1988-09-01

394

Quantifying the chemical ozone loss in the polar vortex during the fifteen winters from 1988-89 to 2002-2003  

NASA Astrophysics Data System (ADS)

Several of the winters during the 1990s are characterised by substantial ozone loss in the north polar vortex. The Arctic sonde network built during the last decade makes it possible to quantify this loss throughout the winter. The ozone mixing ratio based on ozonesonde data from a number of stations is studied as function of time at several isentropic levels (400, 435, 475 and 525 K). Data from 16 stations between 60 and 83N have been used in the study. The ozone data are corrected for the diabatic descent that takes place during the winter. Diabatic descent has been calculated with the Cambridge SLIMCAT model. The model calculated descent has been checked against high-precision tracer measurements. This comparison shows good agreement between modelled and measured descent around 475K. A tracer-tracer correlation (N2O vs CFC-11) also shows that the amount of mixing across the vortex edge at 475K was negligible during mid-winter (late Jan. to early March) of 2000. This means that the observed ozone loss, after the effect of diabatic descent has been accounted for, represents the chemical ozone loss. Results for the 475 K level show that the degree of chemically-induced ozone loss varies a lot from year to year. It is clear from the comparison between the ozone loss and the PSC area that the winters with the biggest ozone loss are the winters that have been cold most of the time from early January and into March. A cold spell, where T drops below TNAT at the end of the winter will of course cause substantial ozone loss, but it will not be enough to cause the same accumulated loss as the most severe winters. The three winters with the most severe loss are 1994-95, 1995-96 and 1999-00. All these winters had PSC temperatures from early December and through most of the winter. Two winters with late cold spells were 1993-94 and 1996-97, but these winters had much less PSCs during the early winter. Whereas the accumulated loss for the three severe winters was around 70% at 475 K, the 1993-94 and 1996-97 winters experienced a loss of 38 and 47%, respectively.

Braathen, G.; Mueller, M.; Sinnhuber, B.-M.; Chipperfield, M.; von der Gathen, P.; Kyro, E.; Mikkelsen, I. S.; Dorokhov, V.; Fast, H.; Parrondo, C.

2003-04-01

395

The roles of different mechanisms related to the tide-induced fronts in the Yellow Sea in summer  

NASA Astrophysics Data System (ADS)

In summer, the Yellow Sea Cold Water Mass (YSCWM) is a stable water mass of low temperature lying at the bottom of the central Yellow Sea (YS). It is fringed by some typical tidal fronts, which separate deep, stratified water on the offshore side from the well-mixed, shallow water on the inshore side. Three striking frontsSubei Bank Front (SBF), Shandong Peninsula Front (SPF), and Mokpo Front (MKF; a front off the southwestern tip of the Korean Peninsula)have been identified by various studies from both satellite observations and model results. Tide plays an important role in the formation and maintenance of these fronts. However, it is still a matter of debate as to the roles these two kinds of mechanisms of upwelling and tidal mixing play, and how importance they are in the maintenance processes of the above three fronts. Basing a nested high-resolution model HYCOM (the Hybrid Coordinate Ocean Model), this study focuses on the different mechanisms of tidal effects on the thermal fronts in the YS in summertime. Through comparative experiments with and without tidal forcing, the results indicate that the MKF is mainly driven by tide-induced upwelling. For the SPF, tidal mixing is the dominant factor, when lower cold water is stirred upwards along the sloping topography of the western YS. Meanwhile, the combined effect of upwelling and tidal mixing is the main cause of the formation of the SBF. Diagnostic analysis of thermal balance shows that horizontal nonlinear advection induced by strong tidal currents also contributes to the thermal balance of frontal areas.

Ren, Shihe; Xie, Jiping; Zhu, Jiang

2014-09-01

396

Writing TAFS for Winter Weather  

NSDL National Science Digital Library

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

Comet

2009-09-22

397

Eddies and thermohaline intrusions of the shelf\\/slope front off the northeast Spanish coast  

Microsoft Academic Search

A low-salinity anticyclonic eddy was found during a field study of the shelf\\/slope front off the northeast Spanish coast in July 1983. The eddy was associated with a tongue of low-salinity, cold water that originated in the Gulf of Lions. Hydrographic stations indicated the presence of multiple salinity-inversion layers. In particular, a relative salinity maximum layer was found at the

Joaqun Tintor; Dong-Ping Wang; Paul E. LaViolette

1990-01-01

398

Observation of convergence, divergence and sinking velocity at a thermohaline front in the Kii Channel, Japan  

Microsoft Academic Search

Detailed flow structure around a thermohaline front in the Kii Channel, Japan, was observed for the first time with the use of an 130 kHz Acoustic Doppler Current Profiler (ADCP). Surface water converged with counter-clockwise motion at the interface between cold coastal water and warm offshore water. After sinking, these waters diverged with a clockwise motion, forming skirt-like distributions in

Tetsuo Yanagi; Kazuhiro Tadokoro; Toshiro Saino

1996-01-01

399

Winter Outdoor Education Activities: Snowshoes and Exploring the Winter Environment.  

ERIC Educational Resources Information Center

Designed as a resource base upon which elementary school educators can build outdoor learning experiences, this resource packet contains a basic, multidisciplinary snowshoeing lesson plan, pre- and post-trip suggestions, and suggestions for further winter outdoor study on snowshoes. Specifically, there are narratives and illustrations addressed at

Matthews, Bruce E.; And Others

400

Cold Surge Activity Over the Gulf of Mexico in a Warmer Climate  

NASA Astrophysics Data System (ADS)

Cold surges are a dominant feature of midlatitude tropical interaction. During the North Hemisphere (NH) winter, midlatitude waves propagating from the Rocky Mountains into the Gulf of Mexico result in cold surges, also known as Nortes or Tehuantepecers, associated with severe weather over the southern part of Mexico. The magnitude of their intense surface winds, precipitation and drops in surface temperature depends on the characteristics of the midlatitude wave propagating into the tropics. The high spatial resolution (20km X 20km) version of the TL959L60-AGC Model of the Meteorological Research Institute of Japan is used to examine changes in cold surge activity under the A1B greenhouse gas emission scenario for the 2080 - 2099 period. The model realistically reproduces the spatial and temporal characteristics of cold surges for the 1980 - 1989 control period. The effect of changes in baroclinicity, static stability and mean flow over North America suggest that in a warmer climate, increased cold surge activity over the Gulf of Mexico would occur. However, these systems would have shorter wavelength (higher phase speeds) and shorter lifespans that could reduce the total amount of winter precipitation. The increased frequency of cold surges over the Gulf of Mexico would be a consequence of weaker baroclinicity and static stability in the lower troposphere over the cold surge genesis region, along with more dominant westerly winds, resulting from ENSO-like conditions in the atmospheric circulations over North America.

Perez, Edgar; Magaa Rueda, Victor; Caetano, Ernesto; Kusunoki, S. %J. Frontiers in Earth Science, Volume 1, id. 19 (2014)

2014-08-01

401

Role of CBFs as Integrators of Chloroplast Redox, Phytochrome and Plant Hormone Signaling during Cold Acclimation  

PubMed Central

Cold acclimation of winter cereals and other winter hardy species is a prerequisite to increase subsequent freezing tolerance. Low temperatures upregulate the expression of C-repeat/dehydration-responsive element binding transcription factors (CBF/DREB1) which in turn induce the expression of COLD-REGULATED (COR) genes. We summarize evidence which indicates that the integration of these interactions is responsible for the dwarf phenotype and enhanced photosynthetic performance associated with cold-acclimated and CBF-overexpressing plants. Plants overexpressing CBFs but grown at warm temperatures mimic the cold-tolerant, dwarf, compact phenotype; increased photosynthetic performance; and biomass accumulation typically associated with cold-acclimated plants. In this review, we propose a model whereby the cold acclimation signal is perceived by plants through an integration of low temperature and changes in light intensity, as well as changes in light quality. Such integration leads to the activation of the CBF-regulon and subsequent upregulation of COR gene and GA 2-oxidase (GA2ox) expression which results in a dwarf phenotype coupled with increased freezing tolerance and enhanced photosynthetic performance. We conclude that, due to their photoautotrophic nature, plants do not rely on a single low temperature sensor, but integrate changes in light intensity, light quality, and membrane viscosity in order to establish the cold-acclimated state. CBFs appear to act as master regulators of these interconnecting sensing/signaling pathways. PMID:23778089

Kurepin, Leonid V.; Dahal, Keshav P.; Savitch, Leonid V.; Singh, Jas; Bode, Rainer; Ivanov, Alexander G.; Hurry, Vaughan; Hner, Norman P. A.

2013-01-01

402

Differential expression of proteins in response to molybdenum deficiency in winter wheat leaves under low-temperature stress  

Technology Transfer Automated Retrieval System (TEKTRAN)

Molybdenum (Mo) is an essential micronutrient for plants. To obtain a better understanding of the molecular mechanisms of cold resistance enhanced by molybdenum application in winter wheat, we applied a proteomic approach to investigate the differential expression of proteins in response to molybden...

403

Ecosystem CO2 production during winter in a Swedish subarctic region: the relative importance of climate and vegetation type  

Microsoft Academic Search

General circulation models consistently predict that regional warming will be most rapid in the Arctic, that this warming will be predominantly in the winter season, and that it will often be accompanied by increasing snowfall. Paradoxically, despite the strong cold season emphasis in these predictions, we know relatively little about the plot and landscape-level controls on tundra biogeochemical cycling in

PAUL G ROGAN; S VEN J ONASSON

2006-01-01

404

Regional-scale winter-spring temperature variability and chilling damage dynamics over the past two centuries in southeastern  

E-print Network

-spring cold extreme is a kind of serious natural disaster for southeastern China. As such events are recorded and driving forces. Here we report a regional-scale winter- spring (January­April) temperature reconstruction.6% of the instrumental temperature variance during the period 1957­2008. The reconstruction shows six relatively warm

Zhang, Qi-Bin

405

Brief Chilling to Subzero Temperature Increases Cold Hardiness in the Hatchling Painted Turtle (Chrysemys picta).  

PubMed

Although many studies of ectothermic vertebrates have documented compensatory changes in cold hardiness associated with changes of season, much less attention has been paid to adjustment of physiological functions and survival limits following more acute exposure to cold. We investigated the ability of hatchling painted turtles (Chrysemys picta) to increase cold hardiness in response to brief exposure to a subzero temperature. Winter-acclimated turtles were "cold conditioned" by chilling them in the supercooled (unfrozen) state to -7 degrees C over a few days before returning them to 4 degrees C. These turtles fared no better than control animals in resisting freezing when cooled in the presence or absence of ice and exogenous ice nuclei. Survival following tests of freeze tolerance (freezing for about 70 h; minimum body temperature, -3.75 degrees C) was nominally higher in cold-conditioned turtles than in controls (36% vs. 13%, respectively), although the difference was not statistically significant. Of the survivors, cold-conditioned turtles apparently recovered sooner. Turtles subjected to cold shock (supercooling to -13 degrees C for 24 h, followed by rewarming to 0 degrees C) were strongly affected by cold conditioning: all controls died, but 50% of cold-conditioned turtles survived. We investigated potential mechanisms underlying the response to cold conditioning by measuring changes in levels of putative cryoprotectants. Plasma levels of glucose and lactate, but not urea, were higher in cold-conditioned turtles than in controls, although the combined increase in these solutes was only 23 mmol L(-1). Cold conditioning attenuated cold-shock injury to brain cells, as assessed using a vital-dye assay, suggesting a link between protection of the nervous system and cold hardiness at the organismal level. PMID:19947887

Muir, Timothy J; Costanzo, Jon P; Lee, Richard E

2010-01-01

406

Dependence of winter water relations of mature high-elevation Picea engelmannii and Abies lasiocarpa on summer climate.  

PubMed

Water relations of Engelmann spruce (Picea engelmannii Parry) and subalpine fir (Abies lasiocarpa (Hook.) Nutt.) trees growing at an elevation of 3230 m on Mt. Evans, Colorado, USA, were studied during the winters of 1995-1996 and 1996-1997. During both winters, current-year and 1-year-old shoots were collected weekly and their relative water contents (RWC) determined. Measured meteorological parameters were used in a conifer winter water relations model, WINWAT, to simulate changes in shoot RWC of P. engelmannii and A. lasiocarpa during the winter. The model failed to predict shoot RWCs in 1996-1997 when calibrated with 1995-1996 data. The cold early summer of 1995 inhibited xylem formation, which appears to have caused lower rates of water recharge to the needles during the 1995-1996 winter than during the 1996-1997 winter. We conclude that summer climate strongly affects winter water relations in these subalpine species, and that changes in both summer and winter climate must be considered when predicting future ranges of these species. PMID:11269959

Boyce, R L; Saunders, G P

2000-10-01

407

USING RADIOTELEMETRY TO MONITOR CARDIAC RESPONSE OF FREE-LIVING TULE GREATER WHITE-FRONTED GEESE (ANSER ALBIFRONS ELGASI )T OHUMAN DISTURBANCE  

Microsoft Academic Search

We monitored the heart rates of free-living Tule Greater White-fronted Geese (Anser albifrons elgasi) during human disturbances on their wintering range in the Sacramento Valley of California during 1997. We used implanted radio transmitters to record the heart rates of geese as an observer experimentally approached them at a constant walking speed. On average, geese flushed when observers were 47

JOSHUA T. ACKERMAN; JOHN Y. TAKEKAWA; KAMMIE L. KRUSE; DENNIS L. ORTHMEYER; JULIE L. YEE; CRAIG R. ELY; DAVID H. WARD; KAREN S. BOLLINGER; DANIEL M. MULCAHY

2004-01-01

408

The Argentine ant persists through unfavorable winters via a mutualism facilitated by a native tree.  

PubMed

Mutualisms and facilitations can fundamentally change the relationship between an organism's realized and fundamental niche. Invasive species may prove particularly suitable models for investigating this relationship as many are dependent on finding new partners for successful establishment. We conducted field-based experiments testing whether a native tree facilitates the successful survival of the invasive Argentine ant, Linepithema humile (Mayr), through unfavorable winter conditions in the southeastern United States. We found Argentine ant nests aggregated around the native loblolly pine, Pinus taeda L., during the winter months. The bark of this tree absorbed enough radiant solar energy to reach temperatures suitable for Argentine ant foraging even when ambient temperatures should have curtailed all foraging. Conversely, foraging ceased when the trunk was shaded. The sun-warmed bark of this tree gave the Argentine ant access to a stable honeydew resource. Argentine ants were not found on or near deciduous trees even though bark temperatures were warm enough to permit Argentine ant foraging on cold winter days. Augmenting deciduous trees with sucrose water through the winter months lead to Argentine ant nests remaining at their base and Argentine ants foraging on the tree. The Argentine ant requires both foraging opportunity and a reliable winter food source to survive through unfavorable winter conditions in the southeastern United States. The loblolly pine provided both of these requirements extending the realized niche of Argentine ants beyond its fundamental niche. PMID:22251714

Brightwell, Robert J; Silverman, Jules

2011-10-01

409

The Mesoscale and Microscale Structure and organization of Clouds and precipitation in Midlatitude Cyclones. Part V: The Substructure of Narrow Cold-Frontal Rainbands  

Microsoft Academic Search

The organization and structure of a narrow cold-frontal rainband (NCFR) on the small mesoscale and the microscale have been investigated through quantitative radar reflectivity, Doppler radar observations, airborne observations and surface measurements. The NCFR was composed of small mesoscale regions of heavy precipitation called `precipitation cores' (PCs) oriented at an angle to the synoptic-scale cold front; in horizontal cross section

Peter V. Hobbs; P. Ola G. Persson

1982-01-01

410

Keep Dogs and Cats Safe During Winter  

MedlinePLUS

... this page, please enable JavaScript. Keep Dogs and Cats Safe During Winter Veterinarian offers tips for helping ... News) -- Winter can be tough on dogs and cats, but there are a number of safe and ...

411

ROV Survey of Winter Quarters Bay  

NSF Publications Database

Title : ROV Survey of Winter Quarters Bay Type : Antarctic EAM NSF Org: OD / OPP Date : January 24 ... Vehicle (ROV) Survey of Winter Quarters Bay) To: File S.7 (Environment) On December 13, 1990, the ...

412

The effect of ocean fronts on acoustic wave propagation in the Celtic Sea  

NASA Astrophysics Data System (ADS)

Underwater noise is now classed as pollution in accordance with the Marine Strategy Framework Directive. Noise from shipping is a major contributor to the ambient noise levels in ocean, particularly at low (< 300 Hz) frequencies. This paper studies patterns and seasonal variations of underwater noise in the Celtic Sea by using a coupled ocean model (POLCOMS) and an acoustic model (HARCAM) in the year 2010. Two sources of sound are considered: (i) representing a typical large cargo ship and (ii) noise from pile-driving activity. In summer, when the source of sound is on the onshore side of the front, the sound energy is mostly concentrated in the near-bottom layer. In winter, the sound from the same source is distributed more evenly in the vertical. The difference between the sound level in summer and winter at 10 m depth is as high as 20 dB at a distance of 40 km. When the source of sound is on the seaward side of the front, the sound level is nearly uniform in the vertical. The transmission loss is also greater (~ 16 dB) in the summer than in the winter for shallow source while it is up to ~ 20 dB for deep source at 30 km.

Shapiro, G.; Chen, F.; Thain, R.

2014-11-01

413

Defending the Axioms Winter 2009  

E-print Network

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

Barrett, Jeffrey A.

414

Learners in Action, Winter 2006  

ERIC Educational Resources Information Center

This Winter 2006 issue of "Learners in Action" contains the following articles: (1) Premiers Honour Adult Learners; (2) Learning Difficulties?; (3) Awards; (4) Hats off to Jacques Demers!; (5) What Do You Think?; (6) Meet the Current Learners Advisory Network; and (7) "Learning Edge" is No Ordinary Magazine!.

Movement for Canadian Literacy, 2006

2006-01-01

415

Anthropolog Fall 2009/Winter 2010  

E-print Network

page 1 Anthropolog Fall 2009/Winter 2010 Newsletter of The Department of Anthropology National was marked by awards given to several of our colleagues. The Department of Anthropology was recognized.After two years of forensic examination and exhaustive genealogical research, the team, with the assistance

Mathis, Wayne N.

416

UNIVERSITY LIBRARY Winter Quarter 2014  

E-print Network

University Library Town Hall 14 #12;Program Management · Program management not limited to library managersUC DAVIS UNIVERSITY LIBRARY TOWN HALL Winter Quarter 2014 March 4, 2014 UC Davis University Library, including the Q&A portion, from the Library's web site http://lib.ucdavis.edu/dept/admin/plan/ March 4, 2014

Ferrara, Katherine W.

417

Winter Storms For More Information  

E-print Network

-related brochures. You can find more information on flash flooding in the Floods... The Awesome Power brochure site http://www.nws.noaa.gov/om/water/ahps/ pdfs/Floodsbrochure_02_06.pdf. To find additional materials of these threats. · A major winter storm can last for several days and be accompanied by high winds, freezing rain

418

Quantitative Methods II Winter 2012  

E-print Network

1 of 3 Quantitative Methods II Winter 2012 Meets: Thursdays 9am ­ 11:50am Professor: Jonathan.northwestern.edu This course is intended to be a continuation of the quantitative methods sequence that began with Quantitative assumptions are violated. We will then discuss various methods researchers use to overcome these obstacles

Bustamante, Fabián E.

419

2013 Winter Cardinal Softball School  

E-print Network

2013 Winter Cardinal Softball School @ Wesleyan University An opportunity to work on your fastpitch, please complete the form below and mail with check payable to "Cardinal Softball School" by January 7th to: Cardinal Softball School Jen Lane, Director Freeman Athletic Center 161 Cross Street Middletown

Royer, Dana

420

Oceanography of the Subtropical Shelf Front Zone in the SW-Atlantic Continental Shelf  

NASA Astrophysics Data System (ADS)

Only physical aspects of the Subtropical Shelf Front (STSF) have been described for the Southwest Atlantic Continental Shelf. The main goal of this paper is to present results of an integrated physical, chemical and biological study at the STSF conducted during the winter of 2003 and summer of 2004. A cross section was established at the historical determined location of the STSF. Nine stations were sampled during the winter cruise and 7 stations during summer. Each section included a series of conductivity-temperature-depth (CTD) stations fitted with dissolved oxygen and turbidity sensors. Selected water samples were filtered and frozen at -20oC for nutrient determination. Samples for chlorophyll were concentrated on filters and these were stored frozen for later processing. Plankton net tows were carried out above and below pycnocline. Surface benthic foraminifera were collected with a bottom snapper. Results revealed that winter was marked by an inner shelf salinity front and the STSF located in the mid-shelf. Inner salinity showed the strong influence of freshwater, with high silicate (71.98 ?M), phosphate (2.70 ?M), nitrate (1.01 ?M), Total Dissolved Nitrogen (22.98 ?M) and suspended matter (44.80 mg/L). With distance from the coast and reduction of terrestrial input, subsurface high values of nutrients were associated with SACW upwelling. As a result, chlorophyll a concentration decreased from coastal well-mixed waters, where values up to 3.0 mg.m3 are registered, to offshore waters. Zooplankton abundance and biomass, and ichthyoplankton abundance follows the same trend. Zoo and ichthyoplankton abundance revealed the presence of 3 groups associated to the inner, mid and offshore shelf region. Benthic foraminifera composition suggested that shallow stations are dominated by few large freshwater species, while offshore stations presented smaller forms and higher species diversity. During summer, the halocline extended over the shelf and joined the STSF in the upper layer. The concentration of inorganic nutrients is reduced in the shallow waters in relation to the winter period, but high values are observed between 40 and 60 m depth and offshore deep waters. Zooplankton biomass was not as high as during winter, and largest values are observed around the STSF. Zoo and ichthyoplankton presented 3 groups, separated by the presence of the STSF. Despite less influence of freshwater during this season, benthic foraminifera were still marked by the presence of freshwater species. The results from this study suggest that during winter, freshwater influence is strong and physical-chemical-biological interactions develop in the front along its plume. However, during summer, when the presence of freshwater is less intense, these interactions seem to take place at the STSF.

Muelbert, J. H.; Acha, M.; Berasategui, A.; Bersano, J. G.; Braga, E. S.; Eichler, P.; Garcia, V. M.; Gomez-Erache, M.; Guerrero, R.; Mianzan, H.; Reta, R.; Ramirez, F.

2005-05-01

421

Snow cover and extreme winter warming events control flower abundance of some, but not all species in high arctic Svalbard  

PubMed Central

Abstract The High Arctic winter is expected to be altered through ongoing and future climate change. Winter precipitation and snow depth are projected to increase and melt out dates change accordingly. Also, snow cover and depth will play an important role in protecting plant canopy from increasingly more frequent extreme winter warming events. Flower production of many Arctic plants is dependent on melt out timing, since season length determines resource availability for flower preformation. We erected snow fences to increase snow depth and shorten growing season, and counted flowers of six species over 5years, during which we experienced two extreme winter warming events. Most species were resistant to snow cover increase, but two species reduced flower abundance due to shortened growing seasons. Cassiope tetragona responded strongly with fewer flowers in deep snow regimes during years without extreme events, while Stellaria crassipes responded partly. Snow pack thickness determined whether winter warming events had an effect on flower abundance of some species. Warming events clearly reduced flower abundance in shallow but not in deep snow regimes of Cassiope tetragona, but only marginally for Dryas octopetala. However, the affected species were resilient and individuals did not experience any long term effects. In the case of short or cold summers, a subset of species suffered reduced reproductive success, which may affect future plant composition through possible cascading competition effects. Extreme winter warming events were shown to expose the canopy to cold winter air. The following summer most of the overwintering flower buds could not produce flowers. Thus reproductive success is reduced if this occurs in subsequent years. We conclude that snow depth influences flower abundance by altering season length and by protecting or exposing flower buds to cold winter air, but most species studied are resistant to changes. Winter warming events, often occurring together with rain, can substantially remove snow cover and thereby expose plants to cold winter air. Depending on morphology, different parts of the plant can be directly exposed. On this picture, we see Dryas octopetala seed heads from the previous growing season protrude through the remaining ice layer after a warming event in early 2010. The rest of the plant, including meristems and flower primordia, are still somewhat protected by the ice. In the background we can see a patch of Cassiope tetragona protruding through the ice; in this case, the whole plant including flower primordia is exposed, which might be one reason why this species experienced a loss of flowers the following season. Photograph by Philipp Semenchuk. PMID:24567826

Semenchuk, Philipp R; Elberling, Bo; Cooper, Elisabeth J

2013-01-01

422

Snow cover and extreme winter warming events control flower abundance of some, but not all species in high arctic Svalbard.  

PubMed

The High Arctic winter is expected to be altered through ongoing and future climate change. Winter precipitation and snow depth are projected to increase and melt out dates change accordingly. Also, snow cover and depth will play an important role in protecting plant canopy from increasingly more frequent extreme winter warming events. Flower production of many Arctic plants is dependent on melt out timing, since season length determines resource availability for flower preformation. We erected snow fences to increase snow depth and shorten growing season, and counted flowers of six species over 5years, during which we experienced two extreme winter warming events. Most species were resistant to snow cover increase, but two species reduced flower abundance due to shortened growing seasons. Cassiope tetragona responded strongly with fewer flowers in deep snow regimes during years without extreme events, while Stellaria crassipes responded partly. Snow pack thickness determined whether winter warming events had an effect on flower abundance of some species. Warming events clearly reduced flower abundance in shallow but not in deep snow regimes of Cassiope tetragona, but only marginally for Dryas octopetala. However, the affected species were resilient and individuals did not experience any long term effects. In the case of short or cold summers, a subset of species suffered reduced reproductive success, which may affect future plant composition through possible cascading competition effects. Extreme winter warming events were shown to expose the canopy to cold winter air. The following summer most of the overwintering flower buds could not produce flowers. Thus reproductive success is reduced if this occurs in subsequent years. We conclude that snow depth influences flower abundance by altering season length and by protecting or exposing flower buds to cold winter air, but most species studied are resistant to changes. Winter warming events, often occurring together with rain, can substantially remove snow cover and thereby expose plants to cold winter air. Depending on morphology, different parts of the plant can be directly exposed. On this picture, we see Dryas octopetala seed heads from the previous growing season protrude through the remaining ice layer after a warming event in early 2010. The rest of the plant, including meristems and flower primordia, are still somewhat protected by the ice. In the background we can see a patch of Cassiope tetragona protruding through the ice; in this case, the whole plant including flower primordia is exposed, which might be one reason why this species experienced a loss of flowers the following season. Photograph by Philipp Semenchuk. PMID:24567826

Semenchuk, Philipp R; Elberling, Bo; Cooper, Elisabeth J

2013-08-01

423

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

Code of Federal Regulations, 2010 CFR

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

2010-07-01

424

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

E-print Network

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

Maxwell, Bruce D.

425

Varietal Trials Results Wheat, Hard Red Winter  

E-print Network

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

Thomas, David D.

426

Leadership in American Indian Communities: Winter Lessons  

ERIC Educational Resources Information Center

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

Metoyer, Cheryl A.

2010-01-01

427

Ice-dependent winter survival of juvenile Atlantic salmon.  

PubMed

Changes in snow and ice conditions are some of the most distinctive impacts of global warming in cold temperate and Arctic regions, altering the environment during a critical period for survival for most animals. Laboratories studies have suggested that reduced ice cover may reduce the survival of stream dwelling fishes in Northern environments. This, however, has not been empirically investigated in natural populations in large rivers. Here, we examine how the winter survival of juvenile Atlantic salmon in a large natural river, the River Alta (Norway, 70N), is affected by the presence or absence of surface ice. Apparent survival rates for size classes corresponding to parr and presmolts were estimated using capture-mark-recapture and Cormack-Jolly-Seber models for an ice-covered and an ice-free site. Apparent survival (?) in the ice-covered site was greater than in the ice-free site, but did not depend on size class (0.64 for both parr and presmolt). In contrast, apparent survival in the ice-free site was lower for larger individuals (0.33) than smaller individuals (0.45). The over-winter decline in storage energy was greater for the ice-free site than the ice-covered site, suggesting that environmental conditions in the ice-free site caused a strong depletion in energy reserves likely affecting survival. Our findings highlight the importance of surface ice for the winter survival of juvenile fish, thus, underpinning that climate change, by reducing ice cover, may have a negative effect on the survival of fish adapted to ice-covered habitats during winter. PMID:23532172

Hedger, R D; Nsje, T F; Fiske, P; Ugedal, O; Finstad, A G; Thorstad, E B

2013-03-01

428

Ice-dependent winter survival of juvenile Atlantic salmon  

PubMed Central

Changes in snow and ice conditions are some of the most distinctive impacts of global warming in cold temperate and Arctic regions, altering the environment during a critical period for survival for most animals. Laboratories studies have suggested that reduced ice cover may reduce the survival of stream dwelling fishes in Northern environments. This, however, has not been empirically investigated in natural populations in large rivers. Here, we examine how the winter survival of juvenile Atlantic salmon in a large natural river, the River Alta (Norway, 70N), is affected by the presence or absence of surface ice. Apparent survival rates for size classes corresponding to parr and presmolts were estimated using capture-mark-recapture and Cormack-Jolly-Seber models for an ice-covered and an ice-free site. Apparent survival (?) in the ice-covered site was greater than in the ice-free site, but did not depend on size class (0.64 for both parr and presmolt). In contrast, apparent survival in the ice-free site was lower for larger individuals (0.33) than smaller individuals (0.45). The over-winter decline in storage energy was greater for the ice-free site than the ice-covered site, suggesting that environmental conditions in the ice-free site caused a strong depletion in energy reserves likely affecting survival. Our findings highlight the importance of surface ice for the winter survival of juvenile fish, thus, underpinning that climate change, by reducing ice cover, may have a negative effect on the survival of fish adapted to ice-covered habitats during winter. PMID:23532172

Hedger, R D; Nsje, T F; Fiske, P; Ugedal, O; Finstad, A G; Thorstad, E B

2013-01-01

429

Reaction front formation in contaminant plumes.  

PubMed

The formation of successive fronts in contaminated groundwater plumes by subsoil bacterial action is a commonly accepted feature of their propagation, but it is not obviously clear from a mathematical standpoint quite how such fronts are formed or propagate. In this paper we show that these can be explained by combining classical reaction-diffusion theory involving just two reactants (oxidant and reductant), and a secondary reaction in which a reactant on one side of such a front is (re-)formed on the other side of the front via diffusion of its product across the front. We give approximate asymptotic solutions for the reactant profiles, and the propagation rate of the front. PMID:25461883

Cribbin, Laura B; Winstanley, Henry F; Mitchell, Sarah L; Fowler, Andrew C; Sander, Graham C

2014-10-25

430

Condensation Front Migration in a Protoplanetary Nebula  

NASA Technical Reports Server (NTRS)

Condensation front dynamics are investigated in the mid-solar nebula region. A quasi-steady model of the evolving nebula is combined with equilibrium vapor pressure curves to determine evolutionary condensation fronts for selected species. These fronts are found to migrate inwards from the far-nebula to final positions during a period of 10(exp 7) years. The physical process governing this movement is a combination of local viscous heating and luminescent heating from the central star. Two luminescent heating models are used and their effects on the ultimate radial position of the condensation front are discussed. At first the fronts move much faster than the nebular accretion velocity, but after a time the accreting gas and dust overtakes the slowing condensation front.

Davis, Sanford S.

2004-01-01

431

Temperature Studies with the Asian Citrus Psyllid, Diaphorina citri: Cold Hardiness and Temperature Thresholds for Oviposition  

PubMed Central

This study was conducted to obtain information on the cold hardiness of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), in Florida and to assess upper and lower temperature thresholds for oviposition. The psyllid is an important pest in citrus because it transmits the bacterial pathogens responsible for citrus greening disease, Huanglongbing, considered the most serious citrus disease worldwide. D. citri was first found in Florida during 1998, and the disease was discovered during 2005. Little was known regarding cold hardiness of D. citri, but Florida citrus is occasionally subjected to notable freeze events. Temperature and duration were each significant sources of variation in percent mortality of D. citri subjected to freeze events. Relatively large percentages of adults and nymphs survived after being exposed for several hours to temperatures as low as -5 to -6 C. Relatively large percentages of eggs hatched after being exposed for several hours to temperatures as low as -8 C. Research results indicated that adult D. citri become cold acclimated during the winter through exposure to cooler winter temperatures. There was no evidence that eggs became cold acclimated during winter. Cold acclimation in nymphs was not investigated. Research with adult D. citri from laboratory and greenhouse colonies revealed that mild to moderate freeze events were usually nonlethal to the D. citri irrespective of whether they were cold acclimated or not. Upper and lower temperature thresholds for oviposition were investigated because such information may be valuable in explaining the geographic distribution and potential spread of the pest from Florida as well as how cooler winter temperatures might limit population growth. The estimated lower and upper thresholds for oviposition were 16.0 and 41.6 C, respectively; the estimated temperature of peak oviposition over a 48 h period was 29.6 C. PMID:21870969

Hall, David G.; Wenninger, Erik J.; Hentz, Matthew G.

2011-01-01

432

Nutrient dynamics in the winter thermohaline frontal zone of the northern shelf region of the South China Sea  

NASA Astrophysics Data System (ADS)

As the first attempt to estimate the nutrient transport across the winter thermohaline frontal zone on the northern shelf of the South China Sea, the nutrient dynamics around the front and the effects of cross-frontal water exchange on nutrient transport were investigated using wintertime field observations. Both water temperature and salinity increased from coastal to oceanic waters, showing the presence of a thermohaline front. The concentrations of dissolved inorganic nutrients decreased oceanward, especially across the thermohaline front, while those of dissolved organic nutrients (i.e., dissolved organic nitrogen (DON) and dissolved organic phosphorus) showed patchy distributions. Ammonium was the major constituent of dissolved inorganic nitrogen, and DON was the main component of total dissolved nitrogen. Molar ratios of PO43-/total dissolved phosphorus decreased from coastal to oceanic waters, indicating that PO43- was rapidly removed and/or consumed from the water column and that organic matter degradation increased offshore, replenishing PO43-. Molar ratios of NO3-/(NH4+ + DON) were 0.01-0.6, indicating dominance of regenerated nitrogen. Surface water convergence and bottom water divergence were identified in the across-shore velocity field, and the calculated across-shore nutrient fluxes suggest that the presence of the winter thermohaline front promotes the offshore transport of nutrients from coastal waters. The transport path begins with convergence of surface coastal waters toward the front, followed by the sinking in the frontal region and the oceanward movement through the bottom layer of the front offshore side. With an assumption of 500 km as the length of thermohaline front on the northern shelf of the South China Sea, the calculated offshore fluxes of nutrients across the entire front are larger than those from the Zhujiang (Pearl River) and the Changjiang (Yangtze River).

Liu, Su Mei; Guo, Xinyu; Chen, Qi; Zhang, Jing; Bi, Yan Feng; Luo, Xin; Li, Jian Bing

2010-11-01

433

Advection from the North Atlantic as the forcing of winter greenhouse effect over Europe  

Microsoft Academic Search

In winter, large interannual fluctuations in the surface temperature are observed over central Europe. Comparing warm February 1990 with cold February 1996, a satellite-retrieved surface (skin) temperature difference of 9.8 K is observed for the region 50-60N 5-35E. Previous studies show that advection from the North Atlantic constitutes the forcing to such fluctuations. The advection is quantified by Index Ina,

J. Otterman; J. Angell; R. Atlas; D. Bungato; S. Schubert; D. Starr; J. Susskind; M.-L. C. Wu

2002-01-01

434

Advection from the North Atlantic as the forcing of winter greenhouse effect over Europe  

Microsoft Academic Search

In winter, large interannual fluctuations in the surface temperature are observed over central Europe. Comparing warm February 1990 with cold February 1996, a satellite-retrieved surface (skin) temperature difference of 9.8 K is observed for the region 5060N; 535E. Previous studies show that advection from the North Atlantic constitutes the forcing to such fluctuations. The advection is quantified by Index Ina,

J. Otterman; J. Angell; R. Atlas; D. Bungato; S. Schubert; D. Starr; J. Susskind; M.-L. C. Wu

2002-01-01

435

Antifreeze proteins in winter rye are similar to pathogenesis-related proteins  

Microsoft Academic Search

The ability to control extracellular ice formation during freezing is critical to the survival of freezing-tolerant plants. Antifreeze proteins, which are proteins that have the ability to retard ice crystal growth, were recently identified as the most abundant apo- plastic proteins in cold-acclimated winter rye (Secale cereale 1.) leaves. In the experiments reported here, amino-terminal sequence comparisons, immuno-cross-reactions, and enzyme

Wai-Ching Hon; Marilyn Criffith; Andrzej Mlynarz; Yan C. Kwok; Daniel S. C. Yang

1995-01-01

436

Physiological response of eight Mediterranean maquis species to low air temperatures during winter  

Microsoft Academic Search

We analyzed the physiological response of the Mediterranean evergreen species (Arbutus unedo L., Cistus incanus L., Erica arborea L., Erica multiflora L., Phillyrea latifolia L., Pistacia lentiscus L., Quercus ilex L., and Rosmarinus officinalis L.) to winter low air temperatures. In occasion of two cold events, in February 2005 (T\\u000a min = 1.8 C), and January 2006 (T\\u000a min =

L. Varone; L. Gratani

2007-01-01

437

Operational forecasting of daily temperatures in the Valencia Region. Part II: minimum temperatures in winter.  

NASA Astrophysics Data System (ADS)

Extreme temperature events have a great impact on human society. Knowledge of minimum temperatures during winter is very useful for both the general public and organisations whose workers have to operate in the open, e.g. railways, roadways, tourism, etc. Moreover, winter minimum temperatures are considered a parameter of interest and concern since persistent cold-waves can affect areas as diverse as public health, energy consumption, etc. Thus, an accurate forecasting of these temperatures could help to predict cold-wave conditions and permit the implementation of strategies aimed at minimizing the negative effects that low temperatures have on human health. The aim of this work is to evaluate the skill of the RAMS model in determining daily minimum temperatures during winter over the Valencia Region. For this, we have used the real-time configuration of this model currently running at the CEAM Foundation. To carry out the model verification process, we have analysed not only the global behaviour of the model for the whole Valencia Region, but also its behaviour for the individual stations distributed within this area. The study has been performed for the winter forecast period from 1 December 2007 - 31 March 2008. The results obtained are encouraging and indicate a good agreement between the observed and simulated minimum temperatures. Moreover, the model captures quite well the temperatures in the extreme cold episodes. Acknowledgement. This work was supported by "GRACCIE" (CSD2007-00067, Programa Consolider-Ingenio 2010), by the Spanish Ministerio de Educacin y Ciencia, contract number CGL2005-03386/CLI, and by the Regional Government of Valencia Conselleria de Sanitat, contract "Simulacin de las olas de calor e invasiones de fro y su regionalizacin en la Comunidad Valenciana" ("Heat wave and cold invasion simulation and their regionalization at Valencia Region"). The CEAM Foundation is supported by the Generalitat Valenciana and BANCAIXA (Valencia, Spain).

Gmez, I.; Estrela, M.

2009-09-01

438

A Late Winter Hydrography in Hidaka Bay, South of Hokkaido, Japan  

Microsoft Academic Search

Hydrographic observations in Hidaka Bay, south of Hokkaido, Japan were carried out in late winter 1996 and 1997 to examine\\u000a the spatial distributions and circulation features of two different water masses, i.e., Coastal Oyashio Water (COW) and Tsugaru\\u000a Warm Water (TWW), and their modifications. It is known that COW is mostly composed of cold and low-salinity water of the melted

Manabu Shimizu; Yutaka Isoda; Kazumi Baba

2001-01-01

439

Cold tolerance of the maize orange leafhopper, Cicadulina bipunctata.  

PubMed

Cicadulina bipunctata was originally distributed in tropical and subtropical regions of the Old World. This leafhopper recently expanded its distribution area to southern parts of temperate Japan. In this study, factors affecting the overwintering ability of C. bipunctata were examined. A series of laboratory experiments revealed that cold acclimation at 15C for 7days enhanced the cold tolerance of C. bipunctata to the same level as an overwintering population, adult females were more tolerant of cold temperature than adult males, and survival of acclimated adult females was highly dependent on temperature from -5 to 5C and exposure duration to the temperature. The temperature of crystallization of adult females was approximately -19C but temperatures in southern temperate Japan rarely dropped below -10C in the winter, indicating that overwintering C. bipunctata adults in temperate Japan are not killed by freezing injury but by indirect chilling injury caused by long-term exposure to moderately low temperatures. An overwintering generation of C. bipunctata had extremely low overwinter survival (<1%) in temperate Japan; however, based on winter temperature ranges, there are additional areas amenable to expansion of C. bipunctata in temperate Japan. PMID:25052348

Matsukura, Keiichiro; Izumi, Yohei; Kumashiro, Shun; Matsumura, Masaya

2014-08-01

440

Seasonal variations in the low-salinity intermediate water in the region south of sub-polar front of the East Sea (Sea of Japan)  

NASA Astrophysics Data System (ADS)

Seasonal variations in the low-salinity intermediate water (ESIW) in the region south of the sub-polar front of the East Sea were investigated by using historical hydrographic data. The salinity of the representative density (sigma-0=27.2) of the ESIW was minimal in summer and maximal in winter in the region south of the sub-polar front. The selected four subregions showed different salinity variations. In the west of Oki Spur and the Yamato Basin, salinity fluctuated similarly, with a minimum during summer. In the Ulleung Basin and northwest of Sado Island, however, variations in salinity showed two minima, one is in winter and the other is in summer. These results imply differences in the flow path of the ESIW into the region south of the sub-polar front over time.

Shin, Chang-Woong; Byun, Sang-Kyung; Kim, Cheolsoo; Lee, Jae Hak; Kim, Bong-Chae; Hwang, Sang-Chull; Seung, Young Ho; Shin, Hong-Ryeol

2013-03-01

441

Distribution patterns of American black duck and mallard winter band recoveries  

USGS Publications Warehouse

We compared the distribution patterns of winter band recoveries of American black ducks (Anas rubripes) and mallards (A. platyrhynchos) banded in the same breeding areas. Young black ducks wintered northeast of young mallards but no differences in distribution patterns were detected between adult birds of the 2 species. Mallards exhibited greater temporal variation in distribution patterns and less fidelity to wintering areas. We speculate that these differences in distribution patterns are related to different behavioral responses by mallards and black ducks to variation in resource availability. Black ducks may reduce energy expenditure during periods of extreme cold and wait for conditions to improve, whereas mallards may migrate to areas that are warmer of where more food is available. The availability of quality habitat may be critical to the survival of black ducks during harsh weather conditions because of their relative lack of migrational flexibility, whereas mallards may be able to respond by migrating to favorable environments.

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

1988-01-01

442

Interannual variation of East Asian Winter Monsoon and ENSO  

SciTech Connect

This paper examines the interannual variation of the East Asian winter monsoon and its relationship with EJSO based on the 1979-1995 NCEP/NCAR reanalysis. Two stratifications of cold surges are used. The first one, described as the conventional cold surges, indicates that the surge frequency reaches a urn one year after El Nino events. The second one, originated from the same region as the first, is defined as the maximum wind events near the South China Sea. The variation of this stratification of surges is found to be in good agreement with the South Oscillation Index (SOI). Low SOI (high SOI) events coincide with years of low (high) surge frequency. The interannual variation of averaged meridional wind near the South China Sea and western Pacific is dominated by the South China Sea cold surges, and is also well correlated (R--O.82) with the SOI. Strong wind seasons are associated with La Nina and high SOI events; likewise, weak wind years are linked with El Nino and low SOI cases. This pattern is restricted north of the equator within the region of (OON-20 N, 11OOE-1300E), and is confined to the near surface layer. The surface Siberian high, 500 hPa trough and 200 hPa jetstream, all representing the large-scale monsoon flow, are found to be weaker than normal during El Nino years. In particular, the interannual variation of the Siberian high is in general agreement with the SOL.

Zhang, Yi; Sperber, Kenneth R.; Boyle, James S.

1996-12-01

443

5 Ultra Cold Neutrons  

Microsoft Academic Search

At the Paul Scherrer Institut (PSI) a new source of ultra cold neutrons (UCN) will be con- structed with the goal to improve the sensitivity to the neutron electric dipole moment (nEDM), which is sensitive to possible contributions from new physics. In addition the neu- tron decay parameters such as its life time may be studied more accurately. Presently, we

P. Fierlinger; S. Heule; U. Straumann

444

Cold Facts about Viruses.  

ERIC Educational Resources Information Center

Provides ways for students to demonstrate their understanding of scientific concepts and skills. Describes a mini-unit around the cold in which students can relate humans to viruses. Includes activities and a modified simulation that provides questions to guide students. Discusses ways that allows students to apply prior knowledge, take ownership

Pea, Celeste; Sterling, Donna R.

2002-01-01

445

Teaching "In Cold Blood."  

ERIC Educational Resources Information Center

The Truman Capote nonfiction novel, "In Cold Blood," which reflects for adolescents the immediacy of the real world, illuminates (1) social issues--capital punishment, environmental influence, and the gap between the "haves" and "have-nots," (2) moral issues--the complexity of man's nature, the responsibility of one man for another, and the place

Berbrich, Joan D.

1967-01-01

446

Galactic Cold Cores  

NASA Astrophysics Data System (ADS)

The aims of the project "Cold Cores" include the compilation of an extensive catalog of dense and cold interstellar dust clouds and the characterization of this source population at large scale in the Galaxy. The sources, which range from pre-stellar cores to already star-forming clouds, are being identified from the Planck satellite all-sky survey. With good coverage of sub-millimeter wavelengths, high sensitivity, and a spatial resolution comparable to that of IRAS satellite, Planck is ideal for this search. Herschel will be used for a more detailed study of some 150 Planck-detected target fields. The Herschel data, combined with ground based follow-up observations, are used to determine the evolutionary stages of the detected sources and to study their physical characteristics and dust properties. The Herschel results help us to better understand the initial phases of star formation and give a key to the statistical interpretation of the much larger sample of sources included in the Planck catalog. We describe the scientific goals of the project and show first results from Herschel Science Demonstration Phase observations. In the fields studied so far, observations have revealed isolated starless cores, cores with embedded sources, and cold dust clumps within regions of active star formation. Thus, the results already demonstrate the large variety of Galactic sources harboring cold dust.

Juvela, Mika; Ristorcelli, Isabelle

447

Expert Cold Structure Development  

NASA Astrophysics Data System (ADS)

The EXPERT Program is funded by ESA. The objective of the EXPERT mission is to perform a sub- orbital flight during which measurements of critical aero- thermodynamic phenomena will be obtained by using state-of-the-art instrumentation. As part of the EXPERT Flight Segment, the responsibility of the Cold Structure Development Design, Manufacturing and Validation was committed to the Belgian industrial team SONACA/SABCA. The EXPERT Cold Structure includes the Launcher Adapter, the Bottom Panel, the Upper Panel, two Cross Panels and the Parachute Bay. An additional Launcher Adapter was manufactured for the separation tests. The selected assembly definition and manufacturing technologies ( machined parts and sandwich panels) were dictated classically by the mass and stiffness, but also by the CoG location and the sensitive separation interface. Used as support for the various on-board equipment, the Cold Structure is fixed to but thermally uncoupled from the PM 1000 thermal shield. It is protect on its bottom panel by a thermal blanket. As it is a protoflight, analysis was the main tool for the verification. Low level stiffness and modal analysis tests have also been performed on the Cold Structure equipped with its ballast. It allowed to complete its qualification and to prepare SONACA/SABCA support for the system dynamic tests foreseen in 2011.

Atkins, T.; Demuysre, P.

2011-08-01

448

COLD NEUTRON SOURCES  

Microsoft Academic Search

Experimental work on cold neutron source development is reviewed along ; with the theoretical explanations devised for the results obtained. Factors ; governing source design, the associated cryogenic and safety problems, large ; source design, and experiments by which source efficiency might be increased are ; also discussed. (D.C.W.);

F WEBB

1963-01-01

449

Titanium Cold Spray Coatings  

NASA Astrophysics Data System (ADS)

Titanium Cold Spray Coatings Cold Spray is an emerging technology used for the deposition of coatings for many industries including aerospace. This technique allows the deposition of metallic materials at low temper-atures below their melting point. The aim of this research was to develop a test technique that can measure the degree to which a cold spray coating achieves mechanical properties similar to a traditional bulk material. Vickers hardness testing and nanoindentation were used as micro-and nano-scale measurement techniques to characterize the mechanical properties of titanium coatings, deposited at different deposition conditions, and bulk Ti. The mechanical properties of bulk titanium and titanium coatings were measured over a range of length scales, with the indentation size effect examined with Meyer's law. Hardness measurements are shown to be affected by material porosity, microstructure and coating particle bonding mechanism. Hard-ness measurements showed that Ti coatings deposited at higher gas pressures and temperatures demonstrate an indentation load response similar to bulk Ti. Key words: titanium, cold spray, Vickers hardness, nanoindentation, indentation size effect, microstructure, mechanical properties

Ajaja, Jihane; Goldbaum, Dina; Chromik, Richard; Yue, Stephen; Rezaeian, Ahmad; Wong, Wilson; Irissou, Eric; Legoux, Jean-Gabriel

450

Light-Front Holographic QCD  

SciTech Connect

The relation between the hadronic short-distance constituent quark and gluon particle limit and the long-range confining domain is yet one of the most challenging aspects of particle physics due to the strong coupling nature of Quantum Chromodynamics, the fundamental theory of the strong interactions. The central question is how one can compute hadronic properties from first principles; i.e., directly from the QCD Lagrangian. The most successful theoretical approach thus far has been to quantize QCD on discrete lattices in Euclidean space-time. Lattice numerical results follow from computation of frame-dependent moments of distributions in Euclidean space and dynamical observables in Minkowski spacetime, such as the time-like hadronic form factors, are not amenable to Euclidean lattice computations. The Dyson-Schwinger methods have led to many important insights, such as the infrared fixed point behavior of the strong coupling constant, but in practice, the analyses are limited to ladder approximation in Landau gauge. Baryon spectroscopy and the excitation dynamics of nucleon resonances encoded in the nucleon transition form factors can provide fundamental insight into the strong-coupling dynamics of QCD. New theoretical tools are thus of primary interest for the interpretation of the results expected at the new mass scale and kinematic regions accessible to the JLab 12 GeV Upgrade Project. The AdS/CFT correspondence between gravity or string theory on a higher-dimensional anti-de Sitter (AdS) space and conformal field theories in physical space-time has led to a semiclassical approximation for strongly-coupled QCD, which provides physical insights into its nonperturbative dynamics. The correspondence is holographic in the sense that it determines a duality between theories in different number of space-time dimensions. This geometric approach le