Science.gov

Sample records for winter cold front

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

    E-print Network

    Huckaby, Daniel Dale

    2001-01-01

    single line drawn on a synoptic chart to indicate a front. To evaluate the behavior of meteorological variables with cold frontal passage, data was collected for seven American cities east of the Rocky Mountains, including NMC/NCEP 3-hourly surface...

  2. Cold fronts in cool core clusters

    E-print Network

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

    2006-11-13

    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.

  3. Cold winters and the relation to atmospheric blocking

    E-print Network

    de Vries, Hylke

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

  4. SOCIAL PERCEPTIONS VERSUS METEOROLOGICAL OBSERVATIONS OF SNOW AND WINTER ALONG THE FRONT RANGE

    E-print Network

    Anderson, Charles W.

    THESIS SOCIAL PERCEPTIONS VERSUS METEOROLOGICAL OBSERVATIONS OF SNOW AND WINTER ALONG THE FRONT VERSUS METEOROLOGICAL OBSERVATIONS OF SNOW AND WINTER ALONG THE FRONT RANGE This research aims meteorological data. The survey also investigated how individual characteristics influence perceptions of snow

  5. Climatology and the time interval of cold fronts passage over South America

    NASA Astrophysics Data System (ADS)

    Pampuch, L. A.; Ambrizzi, T.

    2014-12-01

    Cold fronts affect the weather over South America throughout the year. The south-central region of South America has been identified as highly favorable to the formation and intensification of frontal systems. The fronts usually move from southwest to northeast over the continent and the Atlantic Ocean. During their passage important changes in weather conditions are observed: spinning wind, rainfall, decreasing on atmospheric pressure and temperature. After the passage of a cold front it is usually observed a sharp drop of temperature, pressure increase and wind gusts. There are several studies in the literature about South America cold fronts climatology. However, none of them were performed in pre-defined regions over South America and that have defined the pass interval in each region, which is the goal of the present research. Daily data of temperature on 925hPa, meridional wind in 925hPa and sea level pressure from the ERA Interim reanalysis from ECMWF, with spatial resolution of 1.5 ° x 1.5 ° for the period 1982-2009 were used. The criteria to identify the each cold front were: a drop in temperature, change in wind direction (north to south) and an increase in pressure from day 0 to day +1 for an average of four points for each of the 19 regions of South America. During the year, about 40 frontal systems pass in southern South America and this average is reduced to 10 to the northern regions of the continent. Winter is the season with the highest number of passage of frontal systems, summer is the season that presents lower number and spring and autumn have an intermediate number of fronts of the summer and winter. Analyzing the time interval of cold fronts passage, it was found an average of 8 days in the length of a passage between two fronts in southern Brazil. For the regions further north the interval can reach 26 days during the year. Summer is the season with the longer interval between the passage of fronts and winter and spring shows the smaller intervals.

  6. CYCLONE AND COLD FRONT EVOLUTION OVER THE INTERMOUNTAIN WEST

    E-print Network

    Steenburgh, Jim

    ......................................................................................................................3 2 LIFE CYCLE AND MESOSCALE FRONTAL STRUCTURE OF AN INTERMOUNTAIN CYCLONECYCLONE AND COLD FRONT EVOLUTION OVER THE INTERMOUNTAIN WEST by Gregory Lucas West A dissertation and by Charles A. Wight, Dean of The Graduate School. #12;ABSTRACT Over the Intermountain West, cyclones and cold

  7. Does cold winter weather produce depressive symptoms?

    NASA Astrophysics Data System (ADS)

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

    1988-06-01

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

  8. Cold Fronts in Clusters of Galaxies: Observations and Modeling

    NASA Technical Reports Server (NTRS)

    Markevitch, Maxim

    2012-01-01

    Mergers of galaxy clusters -- some of the most energetic events in the Universe -- produce disturbances in hot intracluster medium, such as shocks and cold fronts, that can be used as tools to study the physics of galaxy clusters. Cold fronts may constrain viscosity and the structure and strength of the cluster magnetic fields. Combined with radio data, these observations also shed light on the production of ultrarelativistic particles that are known to coexist with the cluster thermal plasma. This talk will summarize the current X-ray observations of cluster mergers, as well as some recent radio data and high resolution hydrodynamic simulations.

  9. Liquid detrainment in convection embedded in a cold front

    E-print Network

    Plant, Robert

    Liquid detrainment in convection embedded in a cold front Oscar Martínez-Alvarado Bob Plant;Ensemble detrained liquid water Bulk liquid water (after Plant 2010) N = 350 plumes Analysis method. 1973) The liquid water detrained from each individual plume is given by the bulk value: #12;· Case

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

    E-print Network

    Schultz, David

    A 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 with a pressure trough and a distinct wind shift at the surface. Many cold fronts, however, do not conform

  11. Fast Simulations of Gas Sloshing and Cold Front Formation

    NASA Technical Reports Server (NTRS)

    Roediger, E.; ZuHone, J. A.

    2011-01-01

    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.

  12. Fast Simulations of Gas Sloshing and Cold Front Formation

    NASA Technical Reports Server (NTRS)

    Roediger, E.; ZuHone, J. A.

    2012-01-01

    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.

  13. OIKOS 100: 7178, 2003 Cold winter microenvironments conserve energy and improve

    E-print Network

    Lee Jr., Richard E.

    OIKOS 100: 71­78, 2003 Cold winter microenvironments conserve energy and improve overwintering E. Lee, Jr Irwin, J. T. nd Lee, R. E. Jr 2003. Cold winter microenvironments conserve energy, labora- tory studies have demonstrated that colder winters pro- mote energy conservation (Pullin and Bale

  14. The Life Cycle of an Undular Bore and Its Interaction with a Shallow, Intense Cold Front

    E-print Network

    Martin, Jonathan E.

    The Life Cycle of an Undular Bore and Its Interaction with a Shallow, Intense Cold Front DANIEL C of an undular bore and its associated wind shift, spawned by the passage of a shallow surface cold front over preceded the trailing baroclinic zone by 20 min. Within several hours the bore decayed and a cold frontal

  15. On a theory of the evolution of surface cold fronts

    NASA Technical Reports Server (NTRS)

    Levy, Gad; Bretherton, Christopher S.

    1987-01-01

    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.

  16. Cold fronts and reservoir limnology: an integrated approach towards the ecological dynamics of freshwater ecosystems.

    PubMed

    Tundisi, J G; Matsumura-Tundisi, T; Pereira, K C; Luzia, A P; Passerini, M D; Chiba, W A C; Morais, M A; Sebastien, N Y

    2010-10-01

    In this paper the authors discuss the effects of cold fronts on the dynamics of freshwater ecosystems of southeast South America. Cold fronts originating from the Antarctic show a monthly frequency that promotes turbulence and vertical mixing in reservoirs with a consequence to homogenize nutrient distribution, dissolved oxygen and temperature. Weak thermoclines and the athelomixis process immediately before, during and after the passage of cold fronts interfere with phytoplankton succession in reservoirs. Cyanobacteria blooms in eutrophic reservoirs are frequently connected with periods of stratification and stability of the water column. Cold fronts in the Amazon and Pantanal lakes may produce fish killings during the process of "friagem" associated mixing events. Further studies will try to implement a model to predict the impact of cold fronts and prepare management procedures in order to cope with cyanobacteria blooms during warm and stable water column periods. Changes in water quality of reservoirs are expected during circulation periods caused by cold fronts. PMID:21085786

  17. Winterization of peanut biodiesel to improve the cold flow properties.

    PubMed

    Pérez, Angel; Casas, Abraham; Fernández, Carmen María; Ramos, María Jesús; Rodríguez, Lourdes

    2010-10-01

    Biodiesel is susceptible to start-up and performance problems, consistent with its chemical composition, when vehicles and fuel systems are subjected to cold temperatures. In this work, a comprehensive evaluation of the crystallization behavior of different biodiesels was performed by measuring the cold filter plugging point (CFPP), cloud point (CP) and pour point (PP). Results were related to differential scanning calorimetry (DSC) thermograms. Peanut methyl esters in particular led to the most unfavorable properties due to the presence of long-chain saturated compounds (arachidic or C20:0, behenic or C22:0, and lignoceric or C24:0 acid methyl esters) approaching 6 wt.%. The cold flow properties may be improved with different winterization techniques to eliminate some of these compounds. In this work, various techniques are tested, and the best technique is found to be crystallization filtration using methanol, which reduces the CFPP from 17 degrees C to -8 degrees C with a biodiesel loss of 8.93 wt.%. Moreover, the cake from filtration, enriched with long-chain saturated methyl esters, can be used as phase change material (PCM) for thermo-regulated materials. PMID:20547059

  18. The influence of shelf-sea fronts on winter monsoon over East China Sea

    NASA Astrophysics Data System (ADS)

    Oey, L.-Y.; Chang, M.-C.; Huang, S.-M.; Lin, Y.-C.; Lee, M.-A.

    2015-10-01

    Strong sea surface temperature fronts in open seas are known to affect the atmosphere. Shelf-sea fronts in winter have comparable strengths, yet their impacts on winds have not been studied. In January of 2012, a persistent, narrow band of cloud stretching 600-1,000 km was observed along the front of East China Sea (ECS). Numerical and analytical models show that the cloud was formed atop a recirculating cell induced by the front and, more generally, that ?-plumes of low and high pressures emanate and spread far from fronts. Consistent with the theory, observations show that in ECS at inter-annual time scales, strong fronts co-vary with on-shelf convergent wind, strong northeasterly monsoon, and alongshelf alignment of clouds with low clouds near the coast and higher clouds offshore. Our results suggest that shelf-sea fronts are potentially an important dynamic determinant of climate variability of East Asia.

  19. Influences of the Sierra Nevada on Intermountain Cold-Front Evolution GREGORY L. WEST

    E-print Network

    Steenburgh, Jim

    Influences of the Sierra Nevada on Intermountain Cold-Front Evolution GREGORY L. WEST Department that strong cold fronts develop frequently downstream of the Sierra Nevada over the Intermountain West. To help ascertain why, this paper examines the influence of the Sierra Nevada on the rapidly developing

  20. Atmospheric Cold Fronts Affecting Cold-Water Corals in the Deep Straits of Florida

    NASA Astrophysics Data System (ADS)

    Eberli, G. P.; Grasmueck, M.; Bang, I.; Mooers, C. N.; Viggiano, D.

    2007-12-01

    The Straits of Florida (SoF) are considered an ideal habitat for cold-water corals with the north flowing Florida Current (FC) providing a continuous supply of food. The FC does, however, not fill the entire Straits and deep, opposing undercurrents and coastal countercurrents occur off Florida and the Bahamas. New observational and model data document that, in addition to the well-known perturbation of upper ocean currents by atmospheric cold front passages, the near-bottom current field in the SoF is also repeatedly perturbed by atmospheric cold fronts none of which is reflected in the cold-water mound morphology. Measurements of the near-bottom flow field by an Autonomous Underwater Vehicle (AUV), cruising 40 m above sea floor at five coral mound fields ranging from 14-48 km2 in 590-875 m water in December 2005, record a complicated current pattern in space and time. Near-bottom currents are bi-directional, dominated by semi- diurnal tides, on the lower slopes of the Bahamas where mounds form kilometer long ridges as high as 120 m. Near-bottom currents flow north in the middle of Straits but generally south along the Miami Terrace. The mound morphology varies widely between sites and no obvious (i.e., direct, linear) correlation exists between current strength and mound height. The 12 to 48 h AUV observational data at each site compare well with results of the quasi-operational 3D ocean circulation model EFSIS (East Florida Shelf Information System). The Model enables the analysis of the bottom currents over extended periods and confirms that the near-bottom flow field in the SoF is highly variable on time scales ranging from 6 hours to several days, with magnitudes of +/- 0.2 to 0.6 m/s, depending upon location. During the observation period of December 2005, a recurring current variability is due to a sequence of deep cyclonic eddies that originate approximately every ten days near Cay Sal Bank and move northward on the eastern side of the FC. Offshore Bimini, where the SoF narrows and shoals, and the FC accelerates, the near-bottom eddies intensify and start to move westward. When reaching the Miami Terrace the eddies occupy the entire water column. The timing of the eddies correlate remarkably well with the passage of atmospheric cold fronts. During cold front passages the FC axis is displaced offshore the Florida Keys. A probable mechanism for the generation of the near bottom cyclones is the interaction of FC meanders with Cay Sal Bank. The impact of these "cold-front" perturbations on the deep-water coral communities remains to be quantitatively assessed.

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

    SciTech Connect

    Kaminski, R.M.

    1986-07-01

    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.

  2. Winter Habitat Preferences for Florida Manatees and Vulnerability to Cold

    PubMed Central

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

    2013-01-01

    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

  3. Winter habitat preferences for Florida manatees and vulnerability to cold.

    PubMed

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

    2013-01-01

    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

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

    E-print Network

    Kavanagh, Karen L.

    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

  5. Charge and discharge of polar cold air mass in northern hemispheric winter

    NASA Astrophysics Data System (ADS)

    Kanno, Yuki; Abdillah, Muhammad Rais; Iwasaki, Toshiki

    2015-09-01

    This study shows the variability of polar cold air mass amount below potential temperature of 280 K, and north of 45°N can be understood with a concept of charge and discharge, where anomalously large daily discharge indicates an intermittent occurrence of cold air outbreak. The polar cold air mass amount north of 45°N gradually charges up due to diabatic cooling but dramatically discharges due to cold air outbreak with a pulse width of about 5 days. Cold air outbreaks tend to bring colder winter in East Asia and the east coast of North America, while warmer winter prevails on the northern side of these regions. The cold air mass amount south of 45°N increases just after a cold air outbreak but returns to the normal level soon because of its life time of about 3 days. Therefore, monthly mean of total cold air mass amount in the Northern Hemisphere is negatively correlated with the monthly mean discharge.

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

    SciTech Connect

    Owers, Matt S.; Couch, Warrick J.; Nulsen, Paul E. J.

    2011-11-10

    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.

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

    SciTech Connect

    ZuHone, J. A.; Markevitch, M.; Lee, D.

    2013-01-10

    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.

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

    PubMed

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

    2015-02-01

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

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

    E-print Network

    Naoki Asai; Naoya Fukuda; Ryoji Matsumoto

    2004-04-07

    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.

  10. The role of stratosphere-troposphere coupling in the occurrence of extreme winter cold spells over northern Europe

    E-print Network

    Gerber, Edwin

    between tropospheric winter cold spells over Northern Europe and erosion of the stratospheric polar vortex] The stratospheric polar vortex is a feature of the winter hemisphere climate. Although the stratospheric largeThe role of stratosphere-troposphere coupling in the occurrence of extreme winter cold spells over

  11. Physical changes within a large tropical hydroelectric reservoir induced by wintertime cold front activity

    NASA Astrophysics Data System (ADS)

    Curtarelli, M. P.; Alcântara, E. H.; Rennó, C. D.; Stech, J. L.

    2014-08-01

    We investigated the influence of wintertime cold front activity on the physical processes within a large tropical reservoir located in Brazil. The period chosen for this study consisted of 49 days between 28 April 2010 and 15 July 2010. This period was defined based on information from the Brazilian Center for Weather Forecasting and Climate Studies (CPTEC), data collected in situ and the interpretation of remotely sensed images. To better understand the governing processes that drive changes in the heat balance, differential cooling and mixing dynamics, a simulation was performed that utilized a three-dimensional hydrodynamic model enforced with in situ and remote sensing data. The results showed that during a cold front passage over the reservoir, the sensible and latent heat fluxes were enhanced by approximately 77 and 16%, respectively. The reservoir's daily averaged heat loss was up to 167% higher on the days with cold front activity than on the days without activity. The cold front passage also intensified the differential cooling process; in some cases the difference between the water temperature of the littoral and pelagic zones reached up to 8 °C. The occurrence of cold front passages impacted the diurnal mixed layer (DML), by increasing the turbulent energy input (∼54%) and the DML depth (∼41%). Our results indicate that the cold front events are one of the main meteorological disturbances driving the physical processes within hydroelectric reservoirs located in tropical South America during the wintertime. Hence, cold front activity over these aquatic systems has several implications for water quality and reservoir management in Brazil.

  12. Magnetized thermal conduction fronts. [between hot and cold astrophysical plasma

    NASA Technical Reports Server (NTRS)

    Balbus, S. A.

    1986-01-01

    The evolution of planar thermal conduction fronts in the presence of a dynamically weak, but otherwise self-consistent, magnetic field is considered. The field is assumed to be connected and untangled. In the diffusion limit for the thermal conductivity, these fronts exhibit self-similar behavior, even in the presence of a field. The role of the field is restricted to channeling the heat flux along its lines of force, and it enters into the problem as a dimensionless angle variable. 'Combing' (or opening) of insulating field lines by the evaporative flow is explicitly demonstrated. Unless the field is nearly perpendicular to the front normal in the hot gas, insulating effects are not profound. Self-similarity breaks down if the front becomes saturated, and under certain conditions magnetized saturated conduction fronts cannot propagate: the solution characteristics of the wave equation form caustics. The physical resolution is the advent of two-fluid (nonlocal) heating. Such Coulomb-heated fronts are expected to be relatively rare in typical astrophysical systems. The large-scale effects of a magnetic field on cloud evaporation in the interstellar medium are briefly discussed, and it is suggested that these fields preclude the presence of time-independent evaporative solutions. Thermal interfaces may then continue to evolve until radiative cooling halts their development; large tracts of warm 10,000 K gas may result.

  13. Different Methods of Forming Cold Fronts in Non-Merging Clusters

    E-print Network

    Renato A. Dupke; Raymond E. White III; Joel N. Bregman

    2007-07-26

    Sharp edges in X-ray surface brightness with continuous gas pressure called cold fronts have been often found in relaxed galaxy clusters such as Abell 496. Models that explain cold fronts as surviving cores of head-on subcluster mergers do not work well for these clusters and competing models involving gas sloshing have been recently proposed. Here, we test some concrete predictions of these models in a combined analysis of density, temperature, metal abundances and abundance ratios in a deep Chandra exposure of Abell 496. We confirm that the chemical discontinuities found in this cluster are not consistent with a core merger remnant scenario. However, we find chemical gradients across a spiral "arm" discovered at 73 kpc north of the cluster center and coincident with the sharp edge of the main cold front in the cluster. Despite the overall SN Ia iron mass fraction dominance found within the cooling radius of this cluster, the metal enrichment along the arm, determined from silicon and iron abundances, is consistent with a lower SN Ia iron mass fraction (51% +- 14%) than that measured in the surrounding regions (85% +- 14%). The "arm" is also significantly colder than the surroundings by 0.5-1.6 keV. The arm extends from a boxy colder region surrounding the center of the cluster, where two other cold fronts are found. This cold arm is a prediction of current high resolution numerical simulations as a result of an off-center encounter with a less massive pure dark matter halo and we suggest that the cold fronts in A496 provide the first clear corroboration of such model, where the closest encounter happened ~ 0.5 Gyr ago. We also argue for a possible candidate dark matter halo responsible for the cold fronts in the outskirts of A496.

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

    PubMed

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

    2013-12-01

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

  15. Deep Chandra observation and numerical studies of the nearest cluster cold front in the sky

    NASA Astrophysics Data System (ADS)

    Werner, N.; ZuHone, J. A.; Zhuravleva, I.; Ichinohe, Y.; Simionescu, A.; Allen, S. W.; Markevitch, M.; Fabian, A. C.; Keshet, U.; Roediger, E.; Ruszkowski, M.; Sanders, J. S.

    2016-01-01

    We present the results of a very deep (500 ks) Chandra observation, along with tailored numerical simulations, of the nearest, best resolved cluster cold front in the sky, which lies 90 kpc (19 arcmin) to the north-west of M 87. The northern part of the front appears the sharpest, with a width smaller than 2.5 kpc (1.5 Coulomb mean free paths; at 99 per cent confidence). Everywhere along the front, the temperature discontinuity is narrower than 4-8 kpc and the metallicity gradient is narrower than 6 kpc, indicating that diffusion, conduction and mixing are suppressed across the interface. Such transport processes can be naturally suppressed by magnetic fields aligned with the cold front. Interestingly, comparison to magnetohydrodynamic simulations indicates that in order to maintain the observed sharp density and temperature discontinuities, conduction must also be suppressed along the magnetic field lines. However, the northwestern part of the cold front is observed to have a non-zero width. While other explanations are possible, the broadening is consistent with the presence of Kelvin-Helmholtz instabilities (KHI) on length-scales of a few kpc. Based on comparison with simulations, the presence of KHI would imply that the effective viscosity of the intracluster medium is suppressed by more than an order of magnitude with respect to the isotropic Spitzer-like temperature dependent viscosity. Underneath the cold front, we observe quasi-linear features that are ˜10 per cent brighter than the surrounding gas and are separated by ˜15 kpc from each other in projection. Comparison to tailored numerical simulations suggests that the observed phenomena may be due to the amplification of magnetic fields by gas sloshing in wide layers below the cold front, where the magnetic pressure reaches ˜5-10 per cent of the thermal pressure, reducing the gas density between the bright features.

  16. The Effect of Anisotropic Viscosity on Cold Fronts in Galaxy Clusters

    NASA Technical Reports Server (NTRS)

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

    2014-01-01

    Cold fronts-contact discontinuities in the intracluster medium (ICM) of galaxy clusters-should 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 (is) approximately 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.

  17. THE EFFECT OF ANISOTROPIC VISCOSITY ON COLD FRONTS IN GALAXY CLUSTERS

    SciTech Connect

    ZuHone, J. A.; Markevitch, M.; Biffi, V.

    2015-01-10

    Cold fronts—contact discontinuities in the intracluster medium (ICM) of galaxy clusters—should 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.

  18. Cold War: Flora's Undercover Agents. A Campus Winter Field Trip to Illustrate That Plants Do Indeed Thermoregulate.

    ERIC Educational Resources Information Center

    DeGolier, Teresa

    2002-01-01

    Proposes using a winter field trip to explore how various plants on a campus thermoregulate. Describes techniques for determining the location of cold stresses in plants and how plants manage to deal with the cold stresses. (DDR)

  19. Two distinct influences of Arctic warming on cold winters over North America and East Asia

    NASA Astrophysics Data System (ADS)

    Kug, Jong-Seong; Jeong, Jee-Hoon; Jang, Yeon-Soo; Kim, Baek-Min; Folland, Chris K.; Min, Seung-Ki; Son, Seok-Woo

    2015-10-01

    Arctic warming has sparked a growing interest because of its possible impacts on mid-latitude climate. A number of unusually harsh cold winters have occurred in many parts of East Asia and North America in the past few years, and observational and modelling studies have suggested that atmospheric variability linked to Arctic warming might have played a central role. Here we identify two distinct influences of Arctic warming which may lead to cold winters over East Asia or North America, based on observational analyses and extensive climate model results. We find that severe winters across East Asia are associated with anomalous warmth in the Barents-Kara Sea region, whereas severe winters over North America are related to anomalous warmth in the East Siberian-Chukchi Sea region. Each regional warming over the Arctic Ocean is accompanied by the local development of an anomalous anticyclone and the downstream development of a mid-latitude trough. The resulting northerly flow of cold air provides favourable conditions for severe winters in East Asia or North America. These links between Arctic and mid-latitude weather are also robustly found in idealized climate model experiments and CMIP5 multi-model simulations. We suggest that our results may help improve seasonal prediction of winter weather and extreme events in these regions.

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

    NASA Astrophysics Data System (ADS)

    Zhang, Q.; Liu, H.

    2011-12-01

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

  1. The origin of cold fronts in the cores of relaxed galaxy clusters

    E-print Network

    Ascasibar, Y; Ascasibar, Yago; Markevitch, Maxim

    2006-01-01

    [Abridged] Chandra X-ray observations revealed the presence of cold fronts -- sharp contact discontinuities between gas regions with different temperatures and densities -- in the centers of many, if not most, relaxed clusters with cool cores. We use high-resolution simulations of idealized cluster mergers to address the origin of such fronts. We find that these cold fronts are due to sloshing of the cool gas in the central gravitational potential well, which is easily set off by any minor merger and can persist for gigayears. The only necessary condition for their formation is a steep entropy drop in the gas peak. Most interestingly, the fronts form even if the infalling subcluster has no gas during core passage. If the subhalo had a nonzero impact parameter, the cool gas acquires angular momentum while offset from the center, and does not fall back radially. The resulting cold fronts combine into a characteristic spiral pattern, which initially does not represent any coherent spiraling motion, but evolves i...

  2. Deep Chandra observation and numerical studies of the nearest cluster cold front in the sky

    E-print Network

    Werner, N; Zhuravleva, I; Ichinohe, Y; Simionescu, A; Allen, S W; Markevitch, M; Fabian, A C; Keshet, U; Roediger, E; Ruszkowski, M; Sanders, J S

    2015-01-01

    We present the results of a very deep (500 ks) Chandra observation, along with tailored numerical simulations, of the nearest, best resolved cluster cold front in the sky, which lies 90 kpc (19 arcmin) to the northwest of M 87. The northern part of the front appears the sharpest, with a width smaller than 2.5 kpc (1.5 Coulomb mean free paths; at 99 per cent confidence). Everywhere along the front, the temperature discontinuity is narrower than 4-8 kpc and the metallicity gradient is narrower than 6 kpc, indicating that diffusion, conduction and mixing are suppressed across the interface. Such transport processes can be naturally suppressed by magnetic fields aligned with the cold front. However, the northwestern part of the cold front is observed to have a nonzero width. The broadening is consistent with the presence of Kelvin-Helmholtz instabilities (KHI) on length scales of a few kpc. Based on comparison with simulations, the presence of KHI would imply that the effective viscosity of the intra-cluster medi...

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

    E-print Network

    Arnold, Steve

    Rapid uplift of nonmethane hydrocarbons in a cold front over central Europe R. M. Purvis,1 A. C of 21 C2­C7 nonmethane hydrocarbons (NMHCs) has been determined in planetary boundary layer (PBL between the PBL and FT was observed for all short and medium lifetime hydrocarbons (e.g., average iso

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

    E-print Network

    Palmer, Paul

    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

  5. The Interruption of Alpine Foehn by a Cold Front. Part I: Observations

    E-print Network

    Gohm, Alexander

    ? ? ? ? ? ? ? ? ? ??? #12;5 of 13 Methodology Cold front in complex terrain Case study of MAP event 06 Nov 1999: AWS network Inn Valley: AWS network Pot. Temp. and Wind ­ Hovmoeller diagram west east west east foehn foehn study Wipp Valley: AWS network Pot. Temp. and Wind ­ Hovmoeller diagram Strong and warm foehn

  6. Cold-active winter rye glucanases with ice-binding capacity.

    PubMed

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

    2006-08-01

    Extracellular pathogenesis-related proteins, including glucanases, are expressed at cold temperatures in winter rye (Secale cereale) and display antifreeze activity. We have characterized recombinant cold-induced glucanases from winter rye to further examine their roles and contributions to cold tolerance. Both basic beta-1,3-glucanases and an acidic beta-1,3;1,4-glucanase were expressed in Escherichia coli, purified, and assayed for their hydrolytic and antifreeze activities in vitro. All were found to be cold active and to retain partial hydrolytic activity at subzero temperatures (e.g. 14%-35% at -4 degrees C). The two types of glucanases had antifreeze activity as measured by their ability to modify the growth of ice crystals. Structural models for the winter rye beta-1,3-glucanases were developed on which putative ice-binding surfaces (IBSs) were identified. Residues on the putative IBSs were charge conserved for each of the expressed glucanases, with the exception of one beta-1,3-glucanase recovered from nonacclimated winter rye in which a charged amino acid was present on the putative IBS. This protein also had a reduced antifreeze activity relative to the other expressed glucanases. These results support the hypothesis that winter rye glucanases have evolved to inhibit the formation of large, potentially fatal ice crystals, in addition to having enzymatic activity with a potential role in resisting infection by psychrophilic pathogens. Glucanases of winter rye provide an interesting example of protein evolution and adaptation aimed to combat cold and freezing conditions. PMID:16815958

  7. The Study on Thermal Performance and Applicability of Energy-saving Wall Materials in Hot Summer and Cold Winter Zones 

    E-print Network

    Ren, W.; Lan, M.; Hao, Y.

    2006-01-01

    The hot summer and cold winter zone is a transition zone between the cold zone and hot zone, sweltering in summer and chilly in winter, of which climate is worse. In recent years, with people's raised requirements on indoor living environments...

  8. Event duration (days) European cold winters and persistence of blocking

    E-print Network

    de Vries, Hylke

    of MAX(18-T2M;0). (2) Similar but for Effective Temperature, defined as TEFF=T2M-(2/3)U10M. (3-index correlates reasonably well with cold-indices like D(T2M) and D(TEFF), but there are outliers (e.g. 1991

  9. Back to chemical and other injuries Cold winter temperatures usually injure flower

    E-print Network

    Isaacs, Rufus

    Back to chemical and other injuries Cold winter temperatures usually injure flower buds before buds may begin swelling, then die, whereas partially injured buds may develop only a few normal flowers. Injury can be assessed by dissecting buds: dead flower primordia are dark brown; live primordia are light

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

    E-print Network

    Scotti, Alberto

    Orographic effects during winter cold air outbreaks over the Sea of Japan (East Sea): Results from 27599 Abstract We study the effects of the coastal topography on the western shore of the Sea of Japan equations, orographic effect, gap wind, rotating channel flow, Rossby adjustment, Sea of Japan, air-sea

  11. DYNAMICS AND MAGNETIZATION IN GALAXY CLUSTER CORES TRACED BY X-RAY COLD FRONTS

    SciTech Connect

    Keshet, Uri; Markevitch, Maxim; Birnboim, Yuval; Loeb, Abraham

    2010-08-10

    Cold fronts (CFs)-density and temperature plasma discontinuities-are ubiquitous in cool cores of galaxy clusters, where they appear as X-ray brightness edges in the intracluster medium, nearly concentric with the cluster center. We analyze the thermodynamic profiles deprojected across core CFs found in the literature. While the pressure appears continuous across these CFs, we find that all of them require significant centripetal acceleration beneath the front. This is naturally explained by a tangential, nearly sonic bulk flow just below the CF, and a tangential shear flow involving a fair fraction of the plasma beneath the front. Such shear should generate near-equipartition magnetic fields on scales {approx}<50pc from the front and could magnetize the entire core. Such fields would explain the apparent stability of cool core CFs and the recently reported CF-radio minihalo association.

  12. Dynamics and Magnetization in Galaxy Cluster Cores Traced by X-ray Cold Fronts

    NASA Astrophysics Data System (ADS)

    Keshet, Uri; Markevitch, Maxim; Birnboim, Yuval; Loeb, Abraham

    2010-08-01

    Cold fronts (CFs)—density and temperature plasma discontinuities—are ubiquitous in cool cores of galaxy clusters, where they appear as X-ray brightness edges in the intracluster medium, nearly concentric with the cluster center. We analyze the thermodynamic profiles deprojected across core CFs found in the literature. While the pressure appears continuous across these CFs, we find that all of them require significant centripetal acceleration beneath the front. This is naturally explained by a tangential, nearly sonic bulk flow just below the CF, and a tangential shear flow involving a fair fraction of the plasma beneath the front. Such shear should generate near-equipartition magnetic fields on scales lsim50pc from the front and could magnetize the entire core. Such fields would explain the apparent stability of cool core CFs and the recently reported CF-radio minihalo association.

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

    NASA Astrophysics Data System (ADS)

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

    2013-11-01

    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 Hidrología, Meteorología y Estudios Ambientales of Colombia (IDEAM, based on its initials in Spanish) and the Centro de Investigación en Oceanografía y Meteorología 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.

  14. Recent changes in Arctic temperature extremes: warm and cold spells during winter and summer

    NASA Astrophysics Data System (ADS)

    Matthes, Heidrun; Rinke, Annette; Dethloff, Klaus

    2015-11-01

    In the Arctic, climate change manifests with the strongest warming trends on the globe, especially in the cold season. It is under debate if climate extremes change similarly strong. Our study provides detailed regional information about two selected temperature extreme indices in the Arctic, namely warm and cold spells in winter and summer. We analyze their temporal evolution and variability from 1979–2013, based on daily station data and ERA-Interim reanalysis. Calculated trends from both datasets suggest a widespread decrease of cold spells in winter and summer of up to ?4 days/decade, with regional patches where trends are statistically significant throughout the Arctic. Winter trends are spatially heterogeneous, the reanalysis also shows small areas with statistically significant increases of cold spells throughout Siberia. Calculated changes in warm spells from both datasets are mostly small throughout the Arctic (less than ±1 day/decade) and statistically not significant. Remarkable exceptions are the Lena river basin in winter with a statistically significant decrease of up to ?1.5 days/decade and areas in Scandinavia with statistically significant increases of up to 2.5 days/decade in winter and summer (again from both datasets). From the analysis of spell lengths, we find that there are no shifts from longer to shorter spells or vice versa with time, but long cold spells (events lasting for more than 15 days) disappear almost completely after the year 2000. There is a distinct inter-annual and decadal variability in the spells, which hinders the detection of significant trends for all spell categories in all regions.

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

    SciTech Connect

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

    1996-04-01

    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.

  16. Are cold winters in Europe associated with low solar activity? This article has been downloaded from IOPscience. Please scroll down to see the full text article.

    E-print Network

    Lockwood, Mike

    Are cold winters in Europe associated with low solar activity? This article has been downloaded.1088/1748-9326/5/2/024001 Are cold winters in Europe associated with low solar activity? M Lockwood1,2 , R G Harrison1 , T Woollings1 relatively cold winters in the UK, we investigate the possible connection with solar activity. We identify

  17. Cold Hardiness of Winter-Acclimated Drosophila suzukii (Diptera: Drosophilidae) Adults.

    PubMed

    Stephens, A R; Asplen, M K; Hutchison, W D; Venette, R C

    2015-12-01

    Drosophila suzukii Matsumura, often called spotted wing drosophila, is an exotic vinegar fly that is native to Southeast Asia and was first detected in the continental United States in 2008. Previous modeling studies have suggested that D. suzukii might not survive in portions of the northern United States or southern Canada due to the effects of cold. As a result, we measured two aspects of insect cold tolerance, the supercooling point and lower lethal temperature, for D. suzukii summer-morph pupae and adults and winter-morph adults. Supercooling points were compared to adults of Drosophila melanogaster Meigen. The lower lethal temperature of D. suzukii winter-morph adults was significantly colder than that for D. suzukii summer-morph adults, while supercooling points of D. suzukii winter-morph adults were actually warmer than that for D. suzukii summer-morph adults and pupae. D. suzukii summer-morph adult supercooling points were not significantly different than those for D. melanogaster adults. These measures indicate that D. suzukii is a chill intolerant insect, and winter-morph adults are the most cold-tolerant life stage. These results can be used to improve predictions of where D. suzukii might be able to establish overwintering populations and cause extensive damage to spring fruit crops. PMID:26317777

  18. Winter cold-tolerance thresholds in field-grown Miscanthus hybrid rhizomes

    PubMed Central

    Peixoto, Murilo de Melo; Friesen, Patrick Calvin; Sage, Rowan F.

    2015-01-01

    The cold tolerance of winter-dormant rhizomes was evaluated in diploid, allotriploid, and allotetraploid hybrids of Miscanthus sinensis and Miscanthus sacchariflorus grown in a field setting. Two artificial freezing protocols were tested: one lowered the temperature continuously by 1°C h–1 to the treatment temperature and another lowered the temperature in stages of 24h each to the treatment temperature. Electrolyte leakage and rhizome sprouting assays after the cold treatment assessed plant and tissue viability. Results from the continuous-cooling trial showed that Miscanthus rhizomes from all genotypes tolerated temperatures as low as –6.5 °C; however, the slower, staged-cooling procedure enabled rhizomes from two diploid lines to survive temperatures as low as –14 °C. Allopolyploid genotypes showed no change in the lethal temperature threshold between the continuous and staged-cooling procedure, indicating that they have little ability to acclimate to subzero temperatures. The results demonstrated that rhizomes from diploid Miscanthus lines have superior cold tolerance that could be exploited to improve performance in more productive polyploid lines. With expected levels of soil insulation, low winter air temperatures should not harm rhizomes of tolerant diploid genotypes of Miscanthus in temperate to sub-boreal climates (up to 60°N); however, the observed winter cold in sub-boreal climates could harm rhizomes of existing polyploid varieties of Miscanthus and thus reduce stand performance. PMID:25788733

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

    E-print Network

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

    2007-06-01

    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.

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

    SciTech Connect

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

    2004-01-10

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

  1. Discussion of Air-Conditioning Energy-Savings in Hot-Summer and Cold-Winter Regions 

    E-print Network

    Zheng, W.; Gong, F.; Lou, X.; Cheng, J.

    2006-01-01

    Introducing several kinds of air-conditioning systems energy conservation measures, and according to the climate of the hot-summer and cold-winter region in China, this paper puts forward an overall conception for ...

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

    NASA Astrophysics Data System (ADS)

    Buguet, A. G. C.

    1987-03-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2015-02-01

    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.

  4. The origin of cold fronts in the cores of relaxed galaxy clusters

    E-print Network

    Yago Ascasibar; Maxim Markevitch

    2006-09-08

    Chandra X-ray observations revealed the presence of cold fronts (sharp contact discontinuities between gas regions with different temperatures and densities) in the centers of many, if not most, relaxed clusters with cool cores. We use high-resolution simulations of idealized cluster mergers to show that they are due to sloshing of the cool gas in the central gravitational potential, which is easily set off by minor mergers and can persist for gigayears. The only necessary condition is a steep entropy profile, as observed in cooling flow clusters. Even if the infalling subcluster has no gas during core passage, the gravitational disturbance sets the main mass peak (gas and dark matter together) in motion relative to the surrounding gas. A rapid change in the direction of motion causes a change in ram pressure, which pushes the cool gas away from the dark matter peak and triggers sloshing. For nonzero impact parameters, the cool gas acquires angular momentum, resulting in a characteristic spiral pattern of cold fronts. There is little visible disturbance outside the cool core in such a merger. If the subcluster retains its gas during core passage, the cool central gas of the main cluster is more easily decoupled from the dark matter peak. Subsequently, some of that gas, and often the cool gas from the subcluster, falls back to the center and starts sloshing. However, in such a merger, global disturbances are readily visible in X-rays for a long time. We conclude that cold fronts at the centers of relaxed clusters, often spiral or concentric-arc in shape, are probably caused by encounters with small subhalos stripped of all their gas at the early infall stages.

  5. A physical analysis of the severe 2013/2014 cold winter in North America

    NASA Astrophysics Data System (ADS)

    Yu, Bin; Zhang, Xuebin

    2015-10-01

    The severe 2013/2014 cold winter has been examined in the context of the previous 55 winters using the National Centers for Environmental Prediction reanalysis data for the period 1960-2014. North America is dominated by pronounced cold anomalies over the Great Plains and Great Lakes in December 2013 and February 2014 but exhibits an east-west contrast pattern with warm anomalies over most of the North American West in January 2014. A relevant temperature index, defined as land surface temperature anomalies averaged over (40°-60°N, 105°-80°W), reveals a warming trend as well as interannual variability with a significant power peak of 6.0 years. While 2013/2014 was the second coldest winter during 1960-2014, it is the coldest one in the linearly detrended series, with a negative anomaly of 2.63 standard deviations. This indicates that the long-term warming has made the 2013/2014 winter less severe than it could have been. The temperature and circulation variability in association with the zonally symmetric variability of the polar vortex projects weakly on the corresponding anomalies in the 2013/2014 winter, whereas the variability associated with the principal mode of North American surface temperature projects strongly on the corresponding anomalies in the winter. This mode is associated with a sea surface temperature (SST) pattern of significant anomalies over the North Pacific and North Atlantic middle and high latitudes. The anomalous atmospheric circulation shows an anticyclonic anomaly over the Gulf of Alaska-Bering Sea and a cyclonic anomaly downstream over North America. It bears resemblance to the North Pacific Oscillation/Western Pacific pattern and drives the SST in the North Pacific. Over western-central Canada and the northern U.S., below-average heights are associated with above-normal precipitation, implying enhanced upward vertical motion and variation of local cloud forcing, leading to a variation of the surface energy budget dominated by surface longwave radiation anomalies. Over North America, there is less downwelling longwave radiation at the surface when the atmosphere is cold, which is offset by the corresponding reduction in outgoing longwave radiation.

  6. An experimental study on atmospheric boundary layer in Beijing Suburban Area when a cold front passing

    SciTech Connect

    Liu Huizhi; Zhou Leyi; Hong Zhongxiang

    1996-12-31

    In this paper, the mean fields and fluctuation moments of wind and temperature collected in Beijing Northwest Suburban Area during a cold air outbreak from 29 December 1993 to 3 January 1994 have been computed and analyzed. Wind and temperature fluctuations were measured with FA-11 Ultrasonic Anemometer/Thermometer at 120m in the 325m meteorological tower. The advantage of using the sonic-derived temperature signal arises from the ability to make temperature measurements simultaneously with those of velocity. On the other hand, the ultrasonic anemometer/thermometer can be used in harsh environment and doesn`t exist the radiation errors like other fragile temperature transducers such as fine resistance wires and thermocouple. The sampling rate of the fluctuations is 10 hz. With analyzing the change of the mean profile, the turbulence statistical characteristics, the heat flux when a cold front passing, we have obtained some interesting results. There are as following: (1) Under the near neutral condition when a cold front passing, the distribution of the mean wind velocity below 100m is satisfied with the logarithmic law. However, the mean wind profile at 32 m had a distinctive `kink` at any time. It is shown that the depth of the urban inner boundary layer in this area is 32m or so. That is consistent with other researchers results. (2) During the first cold air surge period from 03:00 to 23:00 at 30 December, 1993, the stability parameter z/1 is near zero. However, the sensible heat flux is upward even in the clear night and the magnitude of it is large. That is because the cold air invaded from the upper layer of ABL and the drop of air temperature began from the upper layer also. Therefore, during cold air invasion, it is shown that there is a strong transportation of the sensible heat flux in ABL besides the traditional viewpoint which the cold advection had played a principal role and the dynamic exchange was distinctive. This is a new discovery.

  7. Evaluation and response of winter cold spells over Western Europe in CMIP5 models

    NASA Astrophysics Data System (ADS)

    Peings, Y.; Cattiaux, J.; Douville, H.

    2013-12-01

    This paper is dedicated to the analysis of winter cold spells over Western Europe in the simulations of the 5th phase of the Coupled Model Intercomparison Project (CMIP5). Both model biases and responses in a warming climate are discussed using historical simulations and the 8.5 W/m2 Representative Concentration Pathway (RCP8.5) scenario, respectively on the 1979-2008 and 2070-2099 periods. A percentile-based index (10th percentile of daily minimum temperature, Q10) with duration and spatial extent criteria is used to define cold spells. Related diagnostics (intensity, duration, extent, and severity as a combination of the former three statistics) of 13 models are compared to observations and suggest that models biases on severity are mainly due to the intensity parameter rather than to duration and extent. Some hypotheses are proposed to explain these biases, that involve large-scale dynamics and/or radiative fluxes related to clouds. Evolution of cold spells characteristics by the end of the century is then discussed by comparing RCP8.5 and historical simulations. In line with the projected rise of mean temperature, "present-climate" cold spells (computed with the 1979-2008 10th percentile, Q10P) are projected to be much less frequent and, except in one model, less severe. When cold spells are defined from the future 10th percentile threshold ("future-climate" cold spells, Q10F), all models simulate a decrease of their intensity linearly related to the seasonal mean warming. Some insights are given to explain the inter-model diversity in the magnitude of the cold spells response. In particular, the snow-albedo feedback is suggested to play an important role, while for some models changes in large-scale dynamics are also not negligible.

  8. Persistent Volcanic Forcing of Severe Cold Winters in Ireland, 430-1650 CE

    NASA Astrophysics Data System (ADS)

    Ludlow, F.; Stine, A.

    2012-12-01

    We present a new record of the occurrence of severe cold events from 430 to 1650 CE derived from writings of medieval Irish scribes. These sources, collectively known as the Irish Annals, represent annual chronicles of important events occurring in the vicinity of major monasteries throughout Ireland. The Irish Annals represent a uniquely homogenous historical record for climate reconstruction because, unlike almost any other European historical archive of this era, records were maintained with great continuity for a common purpose and in a common format at effectively annual resolution for over 1000 years, including the period of the "Dark Ages" after the fall of Rome when comparable sources elsewhere in Europe are scarce. We analyzed over 36,000 individual written entries from 22 major chronicle sources (and several minor sources) and identified all references to cold events, amounting to a total of 70 such events, after exclusion of 13 events deemed historically unreliable (e.g. exaggerated or fabricated). The majority of cold events are reported in the sources as occurring during the winter season. A characteristic example of a written record of severe winter cold occurrence that is considered to be fully historically reliable is the following: Abnormal ice and much snow from the Epiphany [January 6th, Julian Calendar] to Shrovetide. The Boyne and other rivers were crossed dry-footed; lakes likewise… (Source: Annals of Ulster for 818 CE). We find a strong correspondence between cold event occurrence and the record of explosive volcanism derived from sulphate deposition in the GISP2 ice core. We find that 37 of 69 or 53.6% of cold events (excluding 1 cold event at 586 CE for which no GISP2 data is available) correspond with one or more high-SO4 events in the GISP2, a correspondence which we find to be significant at the 99.7% confidence level. Explosive volcanic eruptions are generally understood to produce cooling in the northeastern Atlantic during the summer, but the effects on wintertime temperature in modelling studies are more sensitive to details of where aerosols are first injected. Our result indicates that the dominant effect of the explosive volcanism recorded in the GISP2 ice core on wintertime Irish climate is to produce cooling.

  9. Experimental study of the cold front propagation in the plasma shut-down experiment in the J-TEXT tokamak

    NASA Astrophysics Data System (ADS)

    Huang, Yanhua; Tang, Yi; Luo, Yihui; Huang, Duwei; Jin, Wei; Xiao, Jinshui; Yang, Zhoujun; Chen, Zhongyong

    2014-07-01

    Mitigation of major disruptions is essential in achieving fusion energy as a commercial energy source. Many tokamaks are using massive gas injection (MGI) as the disruption mitigation method since it is the most prospective potential disruption mitigation technique at present. However, mitigation efficiency by gas jet is limited by the shallow penetration of the gas jet which results in low gas mixing efficiency. In order to improve the mixture efficiency, the propagation of the cold front induced by supersonic molecular beam injection and the interaction between the cold front and the q = 2 surface have been studied in the J-TEXT tokamak.

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

    E-print Network

    Owers, Matt S; Couch, Warrick J; Markevitch, Maxim; Poole, Gregory B

    2008-01-01

    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 local...

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

    E-print Network

    Dong, M.; Li, J.

    2006-01-01

    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 conservation zones. In this paper..., 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 and Technology serac. Sunlight...

  12. Isotope meteorology of cold front passages: A case study combining observations and modeling

    NASA Astrophysics Data System (ADS)

    Aemisegger, F.; Spiegel, J. K.; Pfahl, S.; Sodemann, H.; Eugster, W.; Wernli, H.

    2015-07-01

    This study investigates the role of below-cloud evaporation and evapotranspiration for the short-term variability of stable isotopes in near-surface water vapor and precipitation associated with central European cold fronts. To this end, a combination of observations with high temporal resolution and numerical sensitivity experiments with the isotope-enabled regional weather prediction model COSMOiso is used. The representation of the interaction between rain droplets and ambient vapor below the cloud is fundamental for adequately simulating precipitation isotopes (?p) and total rainfall amount. Neglecting these effects leads to depletion biases of 20-40‰ in ?p2H and 5-10‰ in ?p18O and to an increase of 74% in rainfall amount. Isotope fractionation during soil evaporation is of primary importance for correctly simulating the variability of continental low-level vapor ?v2H and ?v18O and particularly of the secondary isotope parameter deuterium excess (dv).

  13. Nitrogen oxides measurements in an Amazon site and enhancements associated with a cold front

    NASA Astrophysics Data System (ADS)

    Cordova, A. M.; Longo, K.; Freitas, S.; Gatti, L. V.; Artaxo, P.; Procópio, A.; Silva Dias, M. A. F.; Freitas, E. D.

    2004-05-01

    An intensive atmospheric chemistry study was carried out in a pristine Amazonian forest site (Balbina), Amazonas state, Brazil during the 2001 wet season, as part of the LBA/CLAIRE 2001 (The Large Scale Biosphere Atmosphere Experiment in Amazonia/Cooperative LBA Airborne Regional Experiment) field campaign. Measurements of nitrogen oxide (NO), nitrogen dioxide (NO2) and ozone (O3) were performed simultaneously with aerosol particles and black carbon concentrations and meteorological parameters observations. Very low trace gases and aerosol concentrations are typically observed at this pristine tropical site. During the measurement period, there was a three-day episode of enhancement of NO2 and black carbon concentration. NO2 concentration reached a maximum value of 4 ppbv, which corresponds to three times the background concentration observed for this site. Black carbon concentration increased from the approximated 100 ng/m3 average value to a 200 ng/m3 maximum during the same period. Biomass burning spots were detected southward, between latitudes 15 to 10° S, 5-6 days before this episode from GOES-8 WF_ABBA (Wildfire Automated Biomass Burning Algorithm). An atmospheric numerical simulation of the whole measurement period was carried out using the RAMS model coupled to a biomass burning emission and transport model. The simulation results pictured a smoke transport event from Central Brazil associated to an approach of a mid-latitude cold front, reinforcing the hypothesis of biomass burning products being long-range transported from the South by the cold front and crossing the Equator. This transport event shows how the pristine atmosphere pattern in Amazonia is impacted by biomass burning emissions from sites very far away.

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

    NASA Astrophysics Data System (ADS)

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

    2013-07-01

    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 Hidrología, Meteorología y Estudios Ambientales of Colombia (IDEAM, based on its initials in Spanish) and Centro de Investigación en Oceanografía y Meteorología 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.

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

    USGS Publications Warehouse

    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

    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.

  16. Geographic variation in Bar-headed Geese Anser indicus: Connectivity of wintering areas and breeding grounds across a broad front

    USGS Publications Warehouse

    Takekawa, J.Y.; Heath, Shane 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

    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.

  17. VHF radar observations of gravity-wave production by cold fronts over southern Australia

    SciTech Connect

    Eckermann, S.D. ); Vincent, R.A. )

    1993-03-15

    Four extended observational campaigns were conducted during August and November 1988 with an ST (stratosphere-troposphere) radar in southern Australia during the passage of cold fronts over the system, giving around 30 days of three-dimensional wind measurements with 15-min time and 0.5-km height resolution over the 2-11.5-km height range. Order of magnitude increases in the variance of time-fluctuating wind velocities were measured during frontal passages, which are ascribed to gravity waves. The time-height morphology of the horizontal and vertical velocity fluctuations differed. Bursts of horizontal velocity variance arose at upper levels about a day before the frontal boundary arrived; this activity extended to lower heights as the front neared. The arrival of the frontal boundary marked a sudden reduction in this activity. After the frontal boundary passed, reduced activity persisted for 12 hours, after which bursts returned at upper levels and persisted typically for about a day. Analysis associates this activity with a spectrum of many saturating inertia-gravity waves with long horizontal wavelengths and large ground-based phase speeds. Bursts in vertical-velocity fluctuations, w[prime], were confined to the troposphere and were quasi-sinusoidal in appearance. These fluctuations are ascribed to gravity waves with high intrinsic frequencies. Significant w[prime] amplitudes were evident after and prior to frontal passage. The largest amplitudes occurred with the onset of strong vertical circulation when the frontal boundary arrived. The smaller w[prime] amplitudes observed in the stratosphere are due in part to the more oblique propagation of wave energy in this more stable environment. Two clear cases of ducted w[prime] oscillations are identified with the aid of radiosonde temperature data from a nearby site. Comparisons between these measurements and the limited numerical modeling of frontal gravity waves show some similarities in wave characteristics.

  18. Storms or cold fronts? What is really responsible for the extreme waves regime in the Colombian Caribbean coast

    NASA Astrophysics Data System (ADS)

    Otero, L. J.; Ortiz-Royero, J. C.; Ruiz-Merchan, J. K.; Higgins, A. E.; Henriquez, S. A.

    2015-05-01

    On Friday, 7 March 2009, a 200 m-long section of the tourist pier in Puerto Colombia collapsed under the impact of the waves generated by a cold front in the area. The aim of this study is to determine the contribution and importance of cold fronts and storms on extreme waves in different areas of the Colombian Caribbean to determine the degree of the threat posed by the flood processes to which these coastal populations are exposed and the actions to which coastal engineering constructions should be subject. In the calculation of maritime constructions, the most important parameter is the wave's height; therefore, it is necessary to definitively know the design wave height to which a coastal engineering structure should be resistant. This wave height varies according to the return period considered. Using Gumbel's extreme value methodology, the significant height values for the study area were calculated. The methodology was evaluated using data from the re-analysis of the spectral NOAA Wavewatch III (WW3) model for 15 points along the 1600 km of the Colombia Caribbean coast (continental and insular) of the last 15 years. The results demonstrated that the extreme waves caused by tropical cyclones and cold fronts have different effects along the Colombian Caribbean coast. Storms and hurricanes are of greater importance in the Guajira Peninsula (Alta Guajira). In the central area formed by Baja Guajira, Santa Marta, Barranquilla, and Cartagena, the strong influence of cold fronts on extreme waves is evident. On the other hand, in the southern region of the Colombian Caribbean coast, from the Gulf of Morrosquillo to the Gulf of Urabá, even though extreme waves are lower than in the previous regions, extreme waves are dominated mainly by the passage of cold fronts. Extreme waves in the San Andrés and Providencia insular region present a different dynamic from that in the continental area due to its geographic location. The wave heights in the extreme regime are similar in magnitude to those found in Alta Guajira, but the extreme waves associated with the passage of cold fronts in this region have lower return periods than the extreme waves associated with hurricane season. These results are of great importance when evaluating the threat of extreme waves in the coastal and port infrastructure, for purposes of the design of new constructions, and in the coastal flood processes due to run-up because, according to the site of interest in the coast, the forces that shape extreme waves are not the same.

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

    NASA Astrophysics Data System (ADS)

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

    2012-11-01

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

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

    SciTech Connect

    Suzuki, Kentaro; Ogawa, Takayuki; Matsumoto, Yosuke; Matsumoto, Ryoji E-mail: ogawa@astro.s.chiba-u.ac.jp E-mail: matumoto@astro.s.chiba-u.ac.jp

    2013-05-10

    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.

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

    SciTech Connect

    Gastaldello, Fabio; Di Gesu, Laura; Ghizzardi, Simona; Rossetti, Mariachiara; Giacintucci, Simona; Girardi, Marisa; Roediger, Elke; Brighenti, Fabrizio; Buote, David A.; Humphrey, Philip J.; Eckert, Dominique; Ettori, Stefano; Mathews, William G.

    2013-06-10

    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.

  2. Spatial use by wintering greater white-fronted geese relative to a decade of habitat change in California's Central Valley

    USGS Publications Warehouse

    Ackerman, J.T.; Takekawa, J.Y.; Orthmeyer, D.L.; Fleskes, J.P.; Yee, J.L.; Kruse, K.L.

    2006-01-01

    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 area used for rice (Oryza sativa) production, and the practice of flooding, rather than burning, rice straw residues for decomposition because of burning restrictions enacted in 1991. Using radiotelemetry, we tracked 192 female geese and recorded 4,516 locations. Geese traveled shorter distances between roosting and feeding sites during 1998-2000 (24.2 ?? 2.2 km) than during 1987-1990 (32.5 ?? 3.4 km); distance traveled tended to decline throughout winter during both decades and varied among watershed basins. Population range size was smaller during 1998-2000 (3,367 km2) than during 1987-1990 (5,145 km2), despite a 2.2-fold increase in the size of the Pacific Flyway population of white-fronted geese during the same time period. The population range size also tended to increase throughout winter during both decades. Feeding and roosting distributions of geese also differed between decades; geese shifted into basins that had the greatest increases in the amount of area in rice production (i.e., American Basin) and out of other basins (i.e., Delta Basin). The use of rice habitat for roosting (1987-1990: 40%, 1998-2000: 54%) and feeding (1987-1990: 57%, 1998-2000: 72%) increased between decades, whereas use of wetlands declined for roosting (1987-1990: 36%, 1998-2000: 31%) and feeding (1987-1990: 22%, 1998-2000: 12%). Within postharvested rice habitats, geese roosted and fed primarily in burned rice fields during 1987-1990 (roost: 43%, feed: 34%), whereas they used flooded rice fields during 1998-2000 (roost: 78%, feed: 64%). Our results suggest that white-fronted geese have altered their spatial use of California's Central Valley during the past decade in response to changing agricultural practices and the implementation of the Central Valley Joint Venture.

  3. Mid-American Review of Sociology, Volume 5, Number 2 (WINTER, 1980): Front Matter

    E-print Network

    1980-04-01

    Gerhard Lenski 1 Sociology and Literature: The Dramatization of An Education Experience Nicholas Ch. Tatsis 101 61 117 121 Vol. V, No.2 Deborah A ~ Willsie and jeffrey w~ Riemer CONTENTS ARTICLES WINTER 1980 Book Reviews Socio-Structural Analysis...... logy in Uppsala, Sweden. . GERHARD LENSKI is Alumni Distinguished Professor of¥~i .logy at the University of North Carolina at Chapel Hill. WitH:n~ wife, Jean Lenski, he has recently completed the fourthed];tion of Human Societies, which is scheduled...

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

    NASA Astrophysics Data System (ADS)

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

    2013-08-01

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

  5. Lesser White-fronted (Anser erythropus) and Greater White-fronted (A. albifrons) Geese wintering in Greek wetlands are not threatened by Pb through shot ingestion.

    PubMed

    Aloupi, Maria; Kazantzidis, Savas; Akriotis, Triantaphyllos; Bantikou, Evangelia; Hatzidaki, Victoria-Ourania

    2015-09-15

    Fecal lead (Pb) levels were investigated in the threatened European population of the Lesser White-fronted Goose (LWfG, Anser erythropus) and of the non-threatened Greater White-fronted Goose (GWfG, Anser albifrons) wintering in two wetland areas in northern Greece in order to assess the potential risk from Pb exposure. Fecal, soil and food plant samples were analyzed. Levels of Pb were normalized using Al concentrations in order to separate the effect of possible ingestion of Pb shot from that of soil or sediment accidentally ingested with food. All concentrations are expressed on a dry weight basis. Geometric means of Pb content in the feces of LWfG were 6.24 mg/kg at Evros Delta and 7.34 mg/kg at Lake Kerkini (maximum values of 28.61 mg/kg and 36.68 mg/kg, respectively); for fecal samples of GWfG geometric means were 2.39 mg/kg at Evros Delta and 6.90 mg/kg at Kerkini (corresponding maximum values of 25.09 mg/kg and 42.26 mg/kg). Soil Pb was in the range of 5.2-60.2mg/kg (geometric mean = 22.6 mg/kg) for the Evros Delta and between 13.4 and 64.9 mg/kg (geometric mean=28.1mg/kg) for Kerkini. A general linear model fitted to the data showed that Pb levels were very closely dependent on Al levels in the feces from both species and at both sites indicating soil or sediment were the only significant source of Pb; species and site, as well as their interaction, were not statistically significant factors. For both species and at both sites exposure to Pb was evidently very mild and the observed levels of Pb were well below the proposed thresholds for lethal or sublethal effects of Pb poisoning. Soil ingestion appeared to gradually increase from October to December for LWfG at Kerkini, corresponding to a gradual depletion of their food source. PMID:25965041

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

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

    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.

  7. Ecological Technologies of a Chinese Traditional Folk House in Hot-Summer and Cold-Winter Zone 

    E-print Network

    Xie, M.; Zhang, G.; Xu, F.

    2006-01-01

    , Shenzhen, China Renewable Energy Resources and a Greener Future Vol.VIII-4-5 Ecological Technologies of a Chinese Traditional Folk House in Hot-Summer and Cold-Winter Zone Mingjing Xie Guoqiang Zhang Feng Xu Ph.D Candidate... temperature in hottest month is 25?-30 ? and the average relative humidity is 80%. The hottest temperature is above 40 Renewable Energy Resources and a Greener Future Vol.VIII-4-5 Fig. 1 The first and second floor plane of 35# house in Yangshan Village...

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

    NASA Astrophysics Data System (ADS)

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

    2013-07-01

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

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

    PubMed

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

    2013-11-01

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

  10. 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)

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

    2013-11-01

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

  11. Winter flounder antifreeze protein genes: demonstration of a cold-inducible promoter and gene transfer to other species

    SciTech Connect

    Huang, R.C.; Gourlie, B.; Price, J.

    1987-05-01

    During the late fall and winter, the winter flounder produces a family of unique antifreeze proteins (AFP) to prevent the lethal formation of ice crystals in its blood. They have been able to induce winter flounder AFP mRNA synthesis in vivo by lowering the ambient temperature of the fish from 18/sup 0/C in the summer months when AFP synthesis is at a minimum to 4/sup 0/C. Furthermore, they have demonstrated and thoroughly investigated this cold induction of AFP mRNA synthesis in vitro in isolated liver tissue and in nuclear preparations isolated from liver tissue. A drug selection vector (pRSV/sub gpt/) which uses RSV promoter for the expression of xanthine-guanine phosphoribosyltransferase (gpt) gene and contains an AFP gene and 1.7 kb of its 5' upstream control region has been constructed for studies of gene transfer into cells of other fish species. These studies were made using a variety of gene transfer techniques into tissue culture cell lines derived from rainbow trout, bluegill, and salmon. Drug resistant colonies from all three species have been obtained and the presence of AFP DNA has been positively identified by Southern analysis. In addition, Northern blot analysis has shown that both gpt gene and AFP gene are active in these cells since mRNA/sub gpt/ and mRNA/sub AFP/ can be detected by probing with the respective gene sequences.

  12. Effect of simulated fall heat waves on cold hardiness and winter survival of hemlock looper, Lambdina fiscellaria (Lepidoptera: Geometridae).

    PubMed

    Vallières, Rosemarie; Rochefort, Sophie; Berthiaume, Richard; Hébert, Christian; Bauce, Éric

    2015-02-01

    The hemlock looper (Lambdina fiscellaria) is an important pest of eastern Canadian forests. The ongoing climate warming could modify the seasonal ecology of this univoltine species that lays eggs at the end of summer and overwinters at this stage. Indeed, the increase in frequency and intensity of extreme climatic events such as fall heat waves could interfere with the winter metabolism of the hemlock looper. Moreover, the host plant quality, which influences the quantity of insect energetic reserves, the geographic origin of populations and the conditions prevailing during the cold acclimation period, could cause various responses of this pest to climate warming. The main objective of this study is to determine the impact of these factors on hemlock looper winter biology. In October 2010, hemlock looper eggs initially collected from two geographic areas in the province of Québec, and from parents reared on two host plants, were exposed to fall heat waves of different intensities during 5 consecutive days. Supercooling points and cryoprotectant levels were measured on eggs on four different dates in 2010-2011 and survival rate was measured in April 2011. Our results show that hemlock looper eggs have a very low supercooling point and high levels of trehalose, glucose and mannitol in September and November. However, there is no clear relationship between the concentration of these compounds and the decrease in supercooling points. Contents in trehalose, glucose and mannitol were significantly influenced by fall heat waves and by the origin of the population. Winter survival of eggs from the temperate population was negatively affected by strong heat waves while the boreal population was not affected. This study suggests that the metabolism and winter survival of temperate hemlock looper populations in Québec will be more affected by fall heat waves that will increase in frequency due to climate change, than boreal populations. PMID:25585353

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

    NASA Technical Reports Server (NTRS)

    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

    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.

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

    NASA Astrophysics Data System (ADS)

    Li, Chunyan; Chen, Changsheng

    2014-11-01

    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.

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

    SciTech Connect

    Stenehjem Gerber, M.

    1992-01-01

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

  16. 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...

  17. Regulatory gene candidates and gene expression analysis of cold acclimation in winter and spring wheat

    E-print Network

    Sarhan, Fathey

    wheat Antonio F. Monroy Æ Ani Dryanova Æ Brigitte Malette Æ Daniel H. Oren Æ Mohammed Ridha Farajalla Æ acclimation to cold by growth at low, above-freezing temperatures. Wheat is one of the most freezing-tolerant plants among major crop species and the wide range of freezing tolerance among wheat cultivars makes

  18. 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...

  19. Coping with the cold: an ecological context for the abundance and distribution of rock sandpipers during winter in upper Cook Inlet, Alaska

    USGS Publications Warehouse

    Ruthrauff, Daniel R.; Gill, Robert E., Jr.; Tibbitts, T. Lee

    2013-01-01

    Shorebirds are conspicuous and abundant at high northern latitudes during spring and summer, but as seasonal conditions deteriorate, few remain during winter. To the best of our knowledge, Cook Inlet, Alaska (60.6? N, 151.6? W), is the world’s coldest site that regularly supports wintering populations of shorebirds, and it is also the most northerly nonbreeding location for shorebirds in the Pacific Basin. During the winters of 1997–2012, we conducted aerial surveys of upper Cook Inlet to document the spatial and temporal distribution and number of Rock Sandpipers (Calidris ptilocnemis) using the inlet. The average survey total was 8191 ± 6143 SD birds, and the average of each winter season’s highest single-day count was 13 603 ± 4948 SD birds. We detected only Rock Sandpipers during our surveys, essentially all of which were individuals of the nominate subspecies (C. p. ptilocnemis). Survey totals in some winters closely matched the population estimate for this subspecies, demonstrating the region’s importance as a nonbreeding resource to the subspecies. Birds were most often found at only a handful of sites in upper Cook Inlet, but shifted their distribution to more southerly locations in the inlet during periods of extreme cold. Two environmental factors allow Rock Sandpipers to inhabit Cook Inlet during winter: 1) an abundant bivalve (Macoma balthica) food source and 2) current and tidal dynamics that keep foraging substrates accessible during all but extreme periods of cold and ice accretion. C. p. ptilocnemis is a subspecies of high conservation concern for which annual winter surveys may serve as a relatively inexpensive population-monitoring tool that will also provide insight into adaptations that allow these birds to exploit high-latitude environments in winter.

  20. Volcanic Winter and Cold Tropical Uplands in Late Paleozoic Pangaea: A Thought Experiment

    NASA Astrophysics Data System (ADS)

    Heavens, N. G.; Soreghan, G. S.

    2014-12-01

    The Late Paleozoic Ice Age (LPIA) was the Earth's most recent icehouse climate prior to the Cenozoic. At present, it is generally accepted that the latitudinal gradient in climate conditions was similar to the present icehouse. High-latitude ice sheets occasionally advanced into the mid-latitudes and retreated once more, but the tropics were warmer or similar in climate to the tropics during the Plio-Pleistocene. Recently, this idea has been challenged by sedimentological evidence of glaciation and dry weathering in upland areas of the tropics as well as geochemical evidence for cold tropical oceans that is consistent with the sedimentological evidence. These observations challenge current qualitative and quantitative models of Late Paleozoic climate, implying tropical climate may have been up to 15 degrees Celsius colder than the present day at some point during the LPIA. Here we consider whether the disparity between evidence for equatorial cold in Pangaea and current models can be explained by explosive volcanic activity associated with events such as the Hercynian orogen or the Kennedy-Connors-Auburn Silicic Large Igneous Province. We find that the necessary radiative forcing for glaciation in low-latitude upland areas could be generated by explosive volcanic activity one to two orders of magnitude greater than the present day, perturbing a baseline climate with mid-latitude glaciation in both hemispheres. Such a forcing would have potentially significant impacts on the carbon cycle and ice sheet dynamics, but these effects are not likely to be unambiguously detectable in the record. Instead, we argue that measurements of mass independent fractionation of S in lacustrine sediments or other deposits sampling meteoric water would be the least ambiguous test of a hypothetical volcanic driver for late Paleozoic cold. This work was supported in part by the National Science Foundation, EAR-1337463.

  1. 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)

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

    2014-09-01

    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 35-45°N and 140-160°E. 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.

  2. The X-ray cavities, filaments and cold fronts in the core of the galaxy group NGC 5044

    E-print Network

    Fabio Gastaldello; David A. Buote; Pasquale Temi; Fabrizio Brighenti; William G. Mathews; Stefano Ettori

    2008-10-22

    We present a two-dimensional analysis of the bright nearby galaxy group NGC 5044 using the currently available Chandra and XMM data. In the inner 10 kpc a pair of cavities are evident together with a set of bright X-ray filaments. If the cavities are interpreted as gas displaced by relativistic plasma inflated by an AGN, even in the absence of extended 1.4 GHz emission, this would be consistent with a recent outburst as also indicated by the extent of dust and H_alpha emission. The soft X-ray filaments coincident with H_alpha and dust emission are cooler than the ones which do not correlate with optical and infrared emission. We suggest that dust-aided cooling contributes to form warm (T =10^4 K) gas, emitting H_alpha radiation. At 31 kpc and 67 kpc a pair of cold fronts are present, indicative of sloshing due to a dynamical perturbation caused by accretion of a less massive group, also suggested by the peculiar velocity of the brightest galaxy NGC 5044 with respect to the mean group velocity.

  3. 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)

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

    2013-12-01

    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.

  4. Impacts of extraordinary warm and cold late-winter temperatures on observed and modelled plant phenology in Switzerland

    NASA Astrophysics Data System (ADS)

    Rutishauser, This; Stöckli, Reto

    2010-05-01

    The impact of gradual change in the climate system during the second half of the 20th century left a strong imprint on the timing of seasonal events in biotic and biotic systems such as e.g. plant development stages and the greenness of the Earth's surface. Temporal trends in seasonal events largely correspond to the effects expected from the increases in temperature. The impact of extraordinary temperature and precipitation events on plant phenology in spring is less understood. For example a strong early-spring frost event in the USA in April 2007 lead to reduced greenness and freeze damage to leaves and fruits of natural and horticultural species whereas a winter warming event in northern Scandinavia in December 2007 caused considerable damage to sub-Arctic dwarf shrub vegetation and reduced vegetation activity (26% reduced maximum Normalized Difference Vegetation Index NDVI relative to the previous year) in the following summer. In Germany and Switzerland, the effects of the extraordinary warm temperature anomalies of autumn 2006, winter 2006/2007 and spring 2007 showed strong impacts on selected plant phenological phases back to 1951 and 1702. Common hazel and snowdrop flowered up to 35 days earlier in Germany and beech and fruits tree were two weeks earlier in Switzerland. This contribution presents empirical evidence of extraordinary warm and cold late-winter temperatures on species-specific plant phenology and modelled landscape-scale phenology in Switzerland in the period 1958-2008. Species-specific observations were extracted from the Swiss Plant Phenological Network of MeteoSwiss for 23 low-altitude stations and 12 stations that report to the Global Climate Observation System (GCOS). Observations cover all climate regions and altitudes. For each GCOS station we also estimated daily Leaf Area Index with a prognostic phenology model. The model's empirical parameter space was constrained by assimilated Fraction of Photosynthetically Active Radiation absorbed by vegetation (FPAR) and Leaf Area Index (LAI) from the MODerate Resolution Imaging Spectroradiometer (MODIS). We present first results from an ongoing study that compares climate impacts of extraordinary characteristics on spring plant and vegetation development at the species and at the landscape level at different altitudes in the Swiss Alps.

  5. How much can we learn from a merging cold front cluster? Insights from X-ray temperature and radio maps of A3667

    SciTech Connect

    Datta, Abhirup; Schenck, David E.; Burns, Jack O.; Skillman, Samuel W.; Hallman, Eric J.

    2014-10-01

    The galaxy cluster A3667 is an ideal laboratory to study the plasma processes in the intracluster medium. High-resolution Chandra X-ray observations show a cold front in A3667. At radio wavelengths, A3667 reveals a double radio-relic feature in the outskirts of the cluster. These suggest multiple merger events in this cluster. In this paper, we analyze the substantial archival X-ray observations of A3667 from the Chandra X-ray Observatory and compare these with existing radio observations as well as state-of-the-art adaptive mesh refinement MHD cosmological simulations using Enzo. We have used two temperature map making techniques, weighted Voronoi tessellation and adaptive circular binning, to produce the high-resolution and largest field-of-view temperature maps of A3667. These high-fidelity temperature maps allow us to study the X-ray shocks in the cluster using a new two-dimensional shock-finding algorithm. We have also estimated the Mach numbers from the shocks inferred from previous ATCA radio observations. The combined shock statistics from the X-ray and radio data are in agreement with the shock statistics in a simulated MHD cluster. We have also studied the profiles of the thermodynamic properties across the cold front using ?447 ks from the combined Chandra observations on A3667. Our results show that the stability of the cold front in A3667 can be attributed to the suppression of the thermal conduction across the cold front by a factor of ?100-700 compared to the classical Spitzer value.

  6. How Much can we Learn from a Merging Cold Front Cluster? Insights from X-Ray Temperature and Radio Maps of A3667

    NASA Astrophysics Data System (ADS)

    Datta, Abhirup; Schenck, David E.; Burns, Jack O.; Skillman, Samuel W.; Hallman, Eric J.

    2014-10-01

    The galaxy cluster A3667 is an ideal laboratory to study the plasma processes in the intracluster medium. High-resolution Chandra X-ray observations show a cold front in A3667. At radio wavelengths, A3667 reveals a double radio-relic feature in the outskirts of the cluster. These suggest multiple merger events in this cluster. In this paper, we analyze the substantial archival X-ray observations of A3667 from the Chandra X-ray Observatory and compare these with existing radio observations as well as state-of-the-art adaptive mesh refinement MHD cosmological simulations using Enzo. We have used two temperature map making techniques, weighted Voronoi tessellation and adaptive circular binning, to produce the high-resolution and largest field-of-view temperature maps of A3667. These high-fidelity temperature maps allow us to study the X-ray shocks in the cluster using a new two-dimensional shock-finding algorithm. We have also estimated the Mach numbers from the shocks inferred from previous ATCA radio observations. The combined shock statistics from the X-ray and radio data are in agreement with the shock statistics in a simulated MHD cluster. We have also studied the profiles of the thermodynamic properties across the cold front using ~447 ks from the combined Chandra observations on A3667. Our results show that the stability of the cold front in A3667 can be attributed to the suppression of the thermal conduction across the cold front by a factor of ~100-700 compared to the classical Spitzer value.

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

    NASA Astrophysics Data System (ADS)

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

    2009-08-01

    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 Niño 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.

  8. Winter Weather Emergencies

    MedlinePLUS

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

  9. Hygroscopic property of water-soluble organic-enriched aerosols in Ulaanbaatar, Mongolia during the cold winter of 2007

    NASA Astrophysics Data System (ADS)

    Jung, Jinsang; King, Young J.; Aggarwal, Shankar Gopala; Kawamura, Kimitaka

    2011-05-01

    The hygroscopic properties of the water-soluble matter extracts of atmospheric aerosols collected at an urban site (47.92° N, 106.90° E, ˜1300 m above sea level) in Ulaanbaatar, Mongolia during the cold winter of 2007 were investigated using a hygroscopicity tandem differential mobility analyzer (H-TDMA). Dynamic shape correction factor ( ?), the ratio of the actual drag force on a non-spherical aerosol particle to that on a sphere of equivalent volume, of the laboratory generated water-soluble matter (WSM) was found to be 1.09-1.38 (avg. 1.23 ± 0.10), implying that particles generated from the WSM are highly non-spherical. The reduction in the mobility diameter can cause ˜11% underestimation in a hygroscopic growth factor at 85% RH. The hygroscopic growth factors at 85% RH ( g(85%)), defined as the ratio of the particle diameter at 85% RH to that at RH < 10% (initial dry diameter), of the WSM (initial dry particle diameter = 100 nm) were 1.32-1.50 (avg. 1.40 ± 0.06). The g(RH) of the water-soluble organic matter (WSOM) was retrieved from the measured g(RH) of the WSM and using the ZSR (Zdanovskii-Stokes-Robinson) approach and the thermodynamic aerosol inorganic model (AIM). We found that the g(85%) of the WSOM were in the range of 1.11-1.35 (avg. 1.22 ± 0.08), which are comparable to those of the biomass burning aerosols.

  10. 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)

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

    2010-11-01

    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 (47.92°N, 106.90°E, ˜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.

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

    PubMed

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

    2013-12-15

    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

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

    USGS Publications Warehouse

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

    1990-01-01

    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.

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

    NASA Astrophysics Data System (ADS)

    Snook, John Stover

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

  14. 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)

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

    2014-08-01

    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.

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

    SciTech Connect

    Lynch, D.V.; Steponkus, P.L. )

    1987-01-01

    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.

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

    PubMed

    de Gruijl, Frank R; Pavel, Stan

    2012-12-01

    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

  17. 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)

    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

    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 6°C 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.

  18. Gravity wave characteristics in the middle atmosphere during the CESAR campaign at Palma de Mallorca in 2011/2012: Impact of extratropical cyclones and cold fronts

    NASA Astrophysics Data System (ADS)

    Kramer, R.; Wüst, S.; Schmidt, C.; Bittner, M.

    2015-06-01

    Based on a measuring campaign which was carried out at Mallorca (39.6°N, 2.7°E) as cooperation between Agència Estatal de Meteorologia (AEMET) and Deutsches Zentrum für Luft- und Raumfahrt, engl. 'German Aerospace Center' (DLR) in 2011/2012 (September-January), 143 radiosondes (day and night) providing vertical temperature and wind profiles were released. Additionally, nocturnal mesopause temperature measurements with a temporal resolution of about 1 min were conducted by the infrared (IR) - Ground-based Infrared P-branch Spectrometer (GRIPS) during the campaign period. Strongly enhanced gravity wave activity in the lower stratosphere is observed which can be attributed to a hurricane-like storm (so-called Medicane) and to passing by cold fronts. Statistical features of gravity wave parameters including energy densitiy and momentum fluxes are calculated. Gravity wave momentum fluxes turned out being up to five times larger during severe weather. Moreover, gravity wave horizontal propagation characteristics are derived applying hodograph and Stokes parameter analysis. Preferred directions are of southeast and northwest due to prevailing wind directions at Mallorca.

  19. Fishery Notes Hard Winters Claim

    E-print Network

    feel that a mild 1978-1979 winter should support good survival of the 1978 year class and pro- vide). The loss is attributed to the very cold winters of 1976-1977 and 1977-1978, the InstilLlte reports spring and summer. A mild 1978-1979 winter is needed to avert a more serious croaker decl ine

  20. 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)

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

    2006-01-01

    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.

  1. Exercising in Cold Weather

    MedlinePLUS

    ... www.nia.nih.gov/Go4Life Exercising in Cold Weather Exercise has benefits all year, even during winter. ... activities when it’s cold outside: l Check the weather forecast. If it’s very windy or cold, exercise ...

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

    NASA Astrophysics Data System (ADS)

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

    2015-02-01

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

  3. 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 ...

  4. Cold Weather Pet Safety

    MedlinePLUS

    ... as huskies and other dogs bred for colder climates, are more tolerant of cold weather; but no ... the winter to generate enough body heat and energy to keep them warm – talk to your veterinarian ...

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    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 Köhler 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.

  6. Annual soil CO2 efflux in a cold temperate forest in northeastern China: effects of winter snowpack and artificial nitrogen deposition.

    PubMed

    Liu, Boqi; Mou, Changcheng; Yan, Guoyong; Xu, Lijian; Jiang, Siling; Xing, Yajuan; Han, Shijie; Yu, Jinghua; Wang, Qinggui

    2016-01-01

    We conducted a snow depth 0?cm (non-snowpack), 10?cm, 20?cm, 30?cm and natural depth) gradient experiment under four quantities of nitrogen addition (control, no added N; low-N, 5?g N m(-2) yr(-1); medium-N, 10?g N m(-2) yr(-1); and high-N, 15?g N m(-2) yr(-1)) and took an-entire-year measurements of soil respiration (Rs) in Korean pine forests in northeastern China during 2013-2014. No evidence for effects of N on Rs could be found during the growing season. On the other hand, reduction of snowpack decreased winter soil respiration due to accompanied relatively lower soil temperature. We found that winter temperature sensitivities (Q10) of Rs were significantly higher than the growing season Q10 under all the N addition treatments. Moderate quantities of N addition (low-N and medium-N) significantly increased temperature sensitivities (Q10) of Rs, but excessive (high-N) addition decreased it during winter. The Gamma empirical model predicted that winter Rs under the four N addition treatments contributed 4.8.?±?0.3% (control), 3.6?±?0.6% (low-N), 4.3?±?0.4% (medium-N) and 6.4?±?0.5% (high-N) to the whole year Rs. Our results demonstrate that N deposition will alter Q10 of winter Rs. Moreover, winter Rs may contribute very few to annual Rs budget. PMID:26732991

  7. Study of a Winter Monsoon Front over the South China Sea by Multi-Sensor Satellite and Weather Radar Data, and a Numerical Model

    NASA Astrophysics Data System (ADS)

    Alpers, Werner; Wong, Wai Kin; Dagestad, Knut-Frode; Chan, Pak Wai

    2013-03-01

    An atmospheric frontal system over the South China Sea (SCS) arising from the replenishment of the northeast monsoon is investigated by using multi-sensor satellite data, weather radar data, and a numerical model. The replenishment or freshening of the northeast monsoon results from the merging of high pressure areas over the Chinese Continent. The near-sea surface wind field associated with this event was measured by the Advanced Scatterometer (ASCAT) onboard the European MetOp satellite and the Advanced Synthetic Aperture Radar (ASAR) onboard the European Envisat satellite. The high resolution ASAR image reveals that the frontal line separating this wind field from the synoptic-scale ambient wind field is as sharp as in the case of a cold air outbreak and contains embedded rain cells. Furthermore, it shows that this replenishment was associated with northeasterly winds with speeds of up to 13 ms-1 over the SCS at offshore distances larger than 60 km, but only with speeds of around 6 ms-1 near the coast. The comparison of the observational data with model results of the pre-operational version of the AIR (Atmospheric Integrated Rapid-cycle) forecast model of the Hong Kong Observatory shows that the AIR model can successfully simulate the time evolution of the frontal system and the wind field over the open ocean, but fails to simulate the wind field near the coast.

  8. Fronts and frontogenesis as revealed by high time resolution data

    NASA Technical Reports Server (NTRS)

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

    1977-01-01

    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.

  9. Building a Weather-Ready Nation Winter Weather Safety

    E-print Network

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

  10. FRONT PANEL BNC FRONT PANEL

    E-print Network

    "1" "0" SOURCE #7 FRONT PANEL BNC SOURCE #8 FRONT PANEL TOGGLE SW. 3-BIT CONTROL FROM HPIB CHASSIS 5 6 7 8 "1" "0" 2 3 4 1 25 HZ SQ. WAVE FROM CLOCK DIST. FROM INTERIM CORRELATOR REAR PANEL BNC INPUTS FRONT PANEL LEDS INDICATE SELECTED INPUT PORT NC NC BANDPASS FILTER 30 MHZ CENTER FREQ 12 MHZ

  11. A late winter hydrographic section from Tasmania to Antarctica

    NASA Astrophysics Data System (ADS)

    Rintoul, Stephen R.; Bullister, John L.

    1999-08-01

    A hydrographic section between Tasmania and Antarctica was occupied in late winter 1991 as part of the World Ocean Circulation Experiment (WOCE). The primary purpose of the WOCE repeat section SR3 is to measure the exchange between the Indian and Pacific Oceans south of Australia. This paper describes the fronts, water masses and transport observed on the first occupation of the repeat section. The Subantarctic Front (SAF) is located between 50°S and 51°S and is the most striking feature of the vertical sections. Two additional fronts at 53°S and 59°S are associated with the Polar Front (PF), part of which turns northward to flow along the section before turning back to the east near 53°S. Very deep (>500 m) mixed layers are found north of the SAF, confirming that Subantarctic Mode Water (SAMW) is formed in this region by deep convection in winter. Chlorofluorocarbons (CFCs) are significantly undersaturated (?90-92% of equilibrium values) in these deep mixed layers, indicating that gas exchange rates are not rapid enough to bring these deep mixed layers to equilibrium by the end of the winter period of deep convective mixing. Northward Ekman drift of cold, fresh water across the SAF is likely to be responsible for the cooler, fresher mixed layers observed immediately north of the SAF. The Antarctic Intermediate Water (AAIW) on the SR3 section is relatively low in oxygen and CFCs (?60-70% and 10-20% of saturation values, respectively), high in potential vorticity, and high in nutrients. These characteristics suggest that the AAIW on this section is not renewed by direct and rapid ventilation near this location. Water mass properties suggest that water from the Tasman Sea spreads south and west across the northern portion of the SR3 section between 800 and 3000 m depth. A cold, fresh, CFC-rich variety of Antarctic Bottom Water is formed along the Wilkes-Adelie coast of Antarctica. The net transport across the section relative to the deepest common depth is 160 Sv. The band of eastward flow between 50°S and 53°S including the SAF carries 137 Sv to the east and dominates the net transport. Weaker flow south of 58°S contributes an additional 70 Sv. The eastward flow is compensated in part by 37 Sv of westward flow between Tasmania and 48.5°S and 8 Sv of flow to the west over the southern flank of the mid-ocean ridge. The trajectories of six ALACE floats deployed at about 950 m confirm the sense of flow inferred from the choice of a deep reference level.

  12. Lateral mixing across ice meltwater fronts of the Chukchi Sea shelf

    NASA Astrophysics Data System (ADS)

    Lu, K.; Weingartner, T.; Danielson, S.; Winsor, P.; Dobbins, E.; Martini, K.; Statscewich, H.

    2015-08-01

    Summer and fall hydrographic sections in the northeastern Chukchi Sea frequently capture 5-20 m thick intrapycnocline lenses or horizontal plumes of warm, moderately salty summer Bering Sea Water flowing northward from Bering Strait. These features occur within the shallow (~20 m depth) pycnocline separating cold, dilute, surface meltwater from near-freezing, salty, winter-formed waters beneath the pycnocline. An idealized numerical model suggests that the features arise from eddies and meanders generated by instability of the surface front separating meltwater from Bering Sea Water. Warm Bering Sea Water is transported across the front and into the pycnocline by the cross-frontal velocities associated with the instabilities. The accompanying lateral eddy heat fluxes may be important both in summer for promoting ice melt and in fall by delaying the onset of ice formation over portions of this shelf. Lateral heat flux magnitudes depend upon the stratification of the Bering Sea Water.

  13. [Front Matter

    E-print Network

    2012-01-01

    of U.S. copyright law, this Article concludes that statutoryLAW REVIEW VOLUME 19 ISSUE 1 WINTER 2012 ARTICLES All Fourlaw's purpose of protecting innovation with its need to promote public availability of copyrighted works, this article

  14. Winter mortality and its causes.

    PubMed

    Keatinge, W R

    2002-11-01

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

  15. WINTER TRITICALE: A FORAGE FOR ALL SEASONS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Winter Triticale (X Triticosecale Wittmack) is usually planted in late summer or early fall, grows vegetatively prior to vernalization by cold winter temperatures and develops reproductively the following spring. Earlier establishment could increase production of high quality forage by extending the...

  16. Social Media: Winter Safety #WinterSafety #WinterPrep

    E-print Network

    of the year. BEFORE the snow and ice start is the time to brush up on your winter weather safety. Check out Social Media: Winter Safety #WinterSafety #WinterPrep Please help the NWS spread to help the NWS build a WeatherReady Nation. Winter Safety Website Winter Storm Watch vs Warning vs

  17. Winter Wonderlands

    ERIC Educational Resources Information Center

    Coy, Mary

    2011-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-01-01

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

  19. Building a Weather-Ready Nation Winter Weather Safety

    E-print Network

    Building a Weather-Ready Nation Winter Weather Safety Snow & Ice ­ Blizzards ­ Freezing Rain & Sleet ­ Cold Temperatures ­ Wind ­ Flooding ­ Fog www.weather.gov/safety #12;Building a Weather-Ready Nation Winter Weather Hazards Winter Weather Safety · Snow & Ice · Blizzards · Freezing Rain & Sleet

  20. The Dok Cold Eddy D. A. MITCHELL*

    E-print Network

    Rhode Island, University of

    The Dok Cold Eddy D. A. MITCHELL* Graduate School of Oceanography, University of Rhode Island June 1999 and July 2001. The focus here is the formation and behavior of a persistent cold eddy observed south of Dok Island, referred to as the Dok Cold Eddy (DCE), and meandering of the Subpolar Front

  1. Cold Sores

    MedlinePLUS

    ... delivered directly to your desktop! more... What Are Cold Sores? Article Chapters What Are Cold Sores? Cold ... January 2012 Previous Next Related Articles: Canker and Cold Sores Aloe Vera May Help Relieve Mouth Sores ...

  2. Cold Stress

    MedlinePLUS

    ... Topics Publications and Products Programs Contact NIOSH COLD STRESS Recommend on Facebook Tweet Share Compartir On this ... cold environments may be at risk of cold stress. Extreme cold weather is a dangerous situation that ...

  3. Nuclear Winter.

    ERIC Educational Resources Information Center

    Ehrlich, Anne

    1984-01-01

    "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)

  4. Annual and interannual variability of the Barents Sea water masses and polar front: 1980-2011

    NASA Astrophysics Data System (ADS)

    Oziel, Laurent; Sirven, Jerome; Gascard, Jean-Claude

    2015-04-01

    The Barents Sea (BS) is a transition area between the warm and saline Atlantic Waters (AW) and the cold and fresh Arctic Waters (ArW). The BS is characterized by a polar front structure separating AW from ArW. The mixing and cooling of these two water mass generates dense waters in winter. Dense waters are of prior importance because they cascade into the Arctic Ocean to form the Artic Intermediate Waters. This study will use a new hydrographic data set fulfilled by recent stations in the Russian area and a 3D model coupled with atmosphere and ice as a back up to investigate the link between fronts and water masses, as well as their variability over the last 30 years. This study suggests that the polar front structure is composed of two branches and that the dense waters are found in between. The BS, especially in the East, is experiencing an "Atlantification" accompanied with a drastic sea ice decline. These changes, amplified during the last decade, shift the southern branch of the polar front structure in the Norh-East direction and affect negatively the dense water formation. This could have major impacts on the Arctic Ocean ventilation and primary production.

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  6. Gene expression analysis to understand cold tolerance in citrus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Citrus cultivars show a wide range of tolerance to cold temperatures. Lemons and limes are known to be sensitive to cold while certain mandarins and trifoliate oranges can endure severe winters. To understand the mechanism of cold tolerance in citrus, we selected three known cold-sensitive and three...

  7. Radiative magnetized thermal conduction fronts

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

    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.

  8. Climate warming will not decrease winter mortality

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

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

  9. Halting Hypothermia: Cold Can Be Dangerous

    MedlinePLUS

    ... who spends much time outdoors in very cold weather can get hypothermia. But hypothermia can happen anywhere— ... just outside and not just in bitter winter weather. It can strike when temperatures are cool—for ...

  10. Winter Games.

    ERIC Educational Resources Information Center

    Tarbuth, Lawson, Comp.

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

  11. 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...

  12. Winter Workshop.

    ERIC Educational Resources Information Center

    Council of Outdoor Educators of Quebec, Montreal.

    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…

  13. 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 ...

  14. Cold intolerance

    MedlinePLUS

    ... intolerance is an abnormal sensitivity to a cold environment or cold temperatures. ... can be a symptom of a problem with metabolism. Some people (often very thin women) do not tolerate cold environments because they have very little body fat and ...

  15. Titan's Winter Polar Vortex

    NASA Technical Reports Server (NTRS)

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

    2008-01-01

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

  16. Cold adaptations.

    PubMed

    Launay, Jean-Claude; Savourey, Gustave

    2009-07-01

    Nowdays, occupational and recreational activities in cold environments are common. Exposure to cold induces thermoregulatory responses like changes of behaviour and physiological adjustments to maintain thermal balance either by increasing metabolic heat production by shivering and/or by decreasing heat losses consecutive to peripheral cutaneous vasoconstriction. Those physiological responses present a great variability among individuals and depend mainly on biometrical characteristics, age, and general cold adaptation. During severe cold exposure, medical disorders may occur such as accidental hypothermia and/or freezing or non-freezing cold injuries. General cold adaptations have been qualitatively classified by Hammel and quantitatively by Savourey. This last classification takes into account the quantitative changes of the main cold reactions: higher or lower metabolic heat production, higher or lesser heat losses and finally the level of the core temperature observed at the end of a standardized exposure to cold. General cold adaptations observed previously in natives could also be developed in laboratory conditions by continuous or intermittent cold exposures. Beside general cold adaptation, local cold adaptation exists and is characterized by a lesser decrease of skin temperature, a more pronounced cold induced vasodilation, less pain and a higher manual dexterity. Adaptations to cold may reduce the occurrence of accidents and improve human performance as surviving in the cold. The present review describes both general and local cold adaptations in humans and how they are of interest for cold workers. PMID:19531907

  17. Volcanic winters

    NASA Technical Reports Server (NTRS)

    Rampino, Michael R.; Self, Stephen; Stothers, Richard B.

    1988-01-01

    The impact of volcanic eruptions on weather and climate is considered. The data from nineteenth-century eruptions is examined, showing the importance of sulfur volatiles for climate change. Information obtained from ice cores is discussed, and the contrasts between the eruptions of Mt. St. Helens and El Chichon are pointed out. The atmospheric effects of the greatest historic eruptions are recalled. The potential for the occurrence of 'volcanic winters' and the possible role of volcanism in mass extinctions are considered.

  18. Winter Blast.

    ERIC Educational Resources Information Center

    MacDonald, Beverley

    1999-01-01

    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)

  19. Leap Day 2012 Severe Storm Front - Duration: 26 seconds.

    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 ...

  20. Greater understanding is need of whether warmer and shorter winters associated with climate change could reduce winter mortality

    NASA Astrophysics Data System (ADS)

    Ebi, Kristie L.

    2015-11-01

    In temperate regions, mortality is higher during winter than summer seasons. Assuming this seasonality is associated with ambient temperature, assessments often conclude that climate change will likely reduce winter mortality. However, there has been limited evaluation of the extent to which cold temperatures are actually the proximal cause of winter mortality in temperate regions. Kinney et al (2015 Environ Res. Lett. 10 064016) analyzed multi-decadal data from 39 cities in the US and France and concluded that cold temperatures are not a primary driver of most winter excess mortality. These analyses suggest that increases in heat-related mortality with climate change will unlikely be balanced by reductions in winter mortality, reinforcing the importance of health systems continuing to ensure adequate health protection against cold temperatures even as temperatures warm.

  1. The Gulf Stream - Troposphere connection: warm and cold paths

    NASA Astrophysics Data System (ADS)

    Czaja, Arnaud; Sheldon, Luke; Vanniere, Benoit; Parfitt, Rhys

    2015-04-01

    In this talk, the role of moist processes in ocean-atmosphere coupling over the Gulf Stream will be discussed, using ERA interim reanalysis data (1979-2012) and nested simulations with the UK Met Office Unified Model. The focus is on the cold season (December through February). Two types of moist processes will be highlighted. First, shallow convection driven by surface fluxes of heat and moisture, usually found behind the cold front of extra-tropical cyclones. It will be shown that the warm flank of the Gulf Stream is instrumental in amplifying these convective events. In addition, it will be suggested that they are also responsible for simulated changes in precipitation found in numerical experiments with Atmospheric General Circulation Models forced with smoothed and realistic sea surface temperature (SST) distributions. The impact of this type of air-sea interaction on the larger scale is however unclear as it mostly affects low levels (below 700hPa). The second type of moist processes of relevance is that of moist inertial ascent along the cold front of extra-tropical cyclones. It will be shown that such ascent typically occurs 10% of the time in winter and that it is preferentially rooted over the warm flank of the Gulf Stream. The moist inertial ascent is intense and narrow, and not compensated within a given synoptic system. As a result, and despite being infrequent, it will be shown to contribute crucially to the time mean upward motion over the Gulf Stream at middle (500hPa) and upper tropospheric levels (300 hPa). This result suggests that warm advection by the Gulf Stream acts in effect as a horizontally broad, downward push, on air masses above the boundary layer, a push required to compensate for the upward mass flux in the moist inertial ascent.

  2. Effects of the Cold Tongue in the South China Sea on the Monsoon, Diurnal Cycle and Rainfall in the Maritime Continent

    NASA Astrophysics Data System (ADS)

    Koseki, Shunya; Koh, Tieh-Yong; Kiat Teo, Chee

    2013-04-01

    We investigate the effects of the Cold Tongue in the South China Sea (SCS) on the winter monsoon, rainfall and diurnal cycle in the Maritime Continent using a numerical model verified with satellite rainfall and reanalysis data. Composite analysis of the observation and reanalysis data based on Cold Tongue Index indicates that the penetration of the monsoon to Java Sea is enhanced when the cold tongue is strong. A sensitivity experiment without the cold tongue shows that the winter monsoon is diminished over SCS and around coastal regions because of anomalous low-level cyclonic circulation associated with enhanced convection over SCS due to the warmer SST. The diurnal cycle, in particular, the night-morning rainfall over the ocean in coastal regions is modified. The effect on daytime rainfall over the land is weaker. Along the northern coast of Java far from SCS, the night-morning rainfall is much reduced over Java Sea when the cold tongue is suppressed because of the weakened land breeze front due to the weakened northerly monsoon. In contrast, the afternoon-evening rainfall on Java Island is enhanced showing that the local impacts are not simply the result of large-scale subsidence from the convective anomaly in SCS. Along the northwestern coast of Borneo adjacent to SCS, the weakened winter monsoon tends to reduce the rainfall at the land breeze front near the coastline. On the other hand, the warmer SST forces a stronger land breeze and the weakened monsoon encourages further and faster offshore propagation of the land breeze front. Consequently, the rainfall peak shifts further offshore in the sensitivity experiment. We conclude that the cold tongue has two effects, the sustenance of a strong monsoon (indirect effect) and the cooling of local SST (direct effect), which have opposite influences on the diurnal cycle in the Maritime Continent. Reference: Koseki, S., T. Y. Koh and C. K. Teo (2012), "Effects of the Cold Tongue in the South China Sea on the Monsoon, Diurnal Cycle and Rainfall in the Maritime Continent", Quarterly Journal of the Royal Meteorological Society, DOI: 10.1002/qj.2052, accepted (early online release).

  3. Measurements of Chlorine Partitioning in the Winter Arctic Stratosphere

    NASA Technical Reports Server (NTRS)

    Stachnik, R.; Salawitch, R.; Engel, A.; Schmidt, U.

    1999-01-01

    Under the extremely cold conditions in the polar winter stratosphere, heterogeneous reactions involving HCl and CIONO(sub 2) on the surfaces of polar stratospheric cloud particles can release large amounts of reactive chlorine from these reservoirs leading to rapid chemical loss of ozone in the Arctic lower stratosphere during late winter and early spring.

  4. Isentropic analysis of polar cold air mass streams

    NASA Astrophysics Data System (ADS)

    Iwasaki, Toshiki; Kanno, Yuki

    2015-04-01

    1. Introduction A diagnostic method is presented of polar cold air mass streams defined below a threshold potential temperature. The isentropic threshold facilitates a Lagrangian view of the cold air mass streams from diabatic generation to disappearance. 2. Mass-weighted isentropic zonal mean (MIM) cold air streams In winter hemispheres, MIM's mass stream functions show a distinct extratropical direct (ETD) cell in addition to the Hadley cell. The mass stream functions have local maxima at around (280K, 45N) for NH winter and, around (280K, 50S) for SH winter. Thus, =280K may be appropriate to a threshold of the polar cold air mass for both hemispheres. The high-latitude downward motion indicates the diabatic generation of cold air mass, whereas the mid-latitude equatorward flow does its outbreak. The strength of equatorward flow is under significant control of wave-mean flow interactions. 3. Geographical distribution of the cold air mass streams in the NH winter In the NH winter, the polar cold air mass flux has two distinct mainstreams, hereafter called as East Asian (EA) stream and the North American (NA) stream. The former grows over the northern part of the Eurasian continent, turns down southeastward toward East Asia and disappears over the western North Pacific Ocean. The latter grows over the Arctic Ocean, flows toward the East Coast of North America and disappears over the western North Atlantic Ocean. These coincide well with main routes of cold surges. 4. Comparison between NH and SH winter streams The cold air mass streams in NH winter are more asymmetric than those in SH winter. The NH total cold air mass below =280K is about 1.5 times greater than the SH one. These come mainly from the topography and land-sea distribution. The mid-latitude mountains steer the cold air mass streams on the northern sides and enhance the residence time over its genesis region.

  5. Common Cold

    MedlinePLUS

    ... NIAID News & Events Volunteer NIAID > Health & Research Topics > Common Cold Skip Website Tools Website Tools Print this page ... Studies Help people who are suffering from the common cold by volunteering for NIAID clinical studies on ClinicalTrials. ...

  6. Common cold

    MedlinePLUS

    The common cold most often causes a runny nose, nasal congestion, and sneezing. You may also have a sore throat, ... 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 ...

  7. FALL WINTER SPRING FALL WINTER SPRING FALL WINTER SPRING SUMMER FALL WINTER SPRING SUMMER FALL WINTER SPRING LIN CALC DIF

    E-print Network

    Bertini, Robert L.

    FALL WINTER SPRING FALL WINTER SPRING FALL WINTER SPRING SUMMER FALL WINTER SPRING SUMMER FALL WINTER SPRING LIN CALC DIF I II ALG IV EQ I MTH MTH MTH MTH MTH 251 252 261 254 256 CHEM CHEM PH PH PH CH

  8. Snowplow Injection Front Effects

    NASA Technical Reports Server (NTRS)

    Moore, T. E.; Chandler, M. O.; Buzulukova, N.; Collinson, G. A.; Kepko, E. L.; Garcia-Sage, K. S.; Henderson, M. G.; Sitnov, M. I.

    2013-01-01

    As the Polar spacecraft apogee precessed through the magnetic equator in 2001, Polar encountered numerous substorm events in the region between geosynchronous orbit and 10 RE geocentric distance; most of them in the plasma sheet boundary layers. Of these, a small number was recorded near the neutral sheet in the evening sector. Polar/Thermal Ion Dynamics Experiment provides a unique perspective on the lowest-energy ion plasma, showing that these events exhibited a damped wavelike character, initiated by a burst of radially outward flow transverse to the local magnetic field at approximately 80 km/s. They then exhibit strongly damped cycles of inward/outward flow with a period of several minutes. After one or two cycles, they culminated in a hot plasma electron and ion injection, quite similar to those observed at geosynchronous orbit. Cold plasmaspheric plasmas comprise the outward flow cycles, while the inward flow cycles contain counterstreaming field-parallel polar wind-like flows. The observed wavelike structure, preceding the arrival of an earthward moving substorm injection front, suggests an outward displacement driven by the inward motion at local times closer to midnight, that is, a "snowplow" effect. The damped in/out flows are consistent with interchange oscillations driven by the arrival at the observed local time by an injection originating at greater radius and local time.

  9. Cold Pools in the Columbia Basin

    SciTech Connect

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

    2001-01-01

    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.

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

    E-print Network

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

    2010-10-01

    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...

  11. Cold galaxies

    NASA Astrophysics Data System (ADS)

    Rowan-Robinson, Michael; Clements, David L.

    2015-10-01

    We use 350 ?m angular diameter estimates from Planck to test the idea that some galaxies contain exceptionally cold (10-13 K) dust, since colder dust implies a lower surface brightness radiation field illuminating the dust, and hence a greater physical extent for a given luminosity. The galaxies identified from their spectral energy distributions as containing cold dust do indeed show the expected larger 350 ?m diameters. For a few cold dust galaxies where Herschel data are available, we are able to use submillimetre maps or surface brightness profiles to locate the cold dust, which as expected generally lies outside the optical galaxy.

  12. Cold Fusion.

    ERIC Educational Resources Information Center

    Dutton, Eileen; Salazar, Chris

    1998-01-01

    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)

  13. Physiological processes during winter dormancy and their ecological significance

    SciTech Connect

    Havranek, W.M.; Tranquillini, W.

    1995-07-01

    Lengthy and severe winters require that trees in the forests of boreal and mountain zones undergo winter dormancy. Physiologically, a high resistance to subfreezing temperatures and concomitant dehydration are necessary. To accomplish this dormancy, both physiological and structural changes are needed at the cellular level that require induction by endogenous and photoperiodic control early in autumn. Endogenous rhythmicity promotes cold hardening in early autumn and the persistence of hardiness throughout the winter. Numerous physiological functions are maintained at a reduced level, or become completely inhibited during true winter dormancy. Winter hardiness also includes the capability to minimize water loss effectively when water uptake is severely impeded or impossible. Anatomical features such as tracheids act to minimize xylem embolism during frequent freeze-thaw cycles, and {open_quotes}crown{close_quotes} tissues enable buds to stay in a dehydrated and, thus, more resistant state during winter. Both these structural features are adaptations that contribute to the dominance of conifers in cold climates. Interestingly, deciduous tree species rather than evergreen conifers dominate in the most severe winter climates, although it is not clear whether limitations during winter, during the summer growth period, or during both are most limiting to conifer tree ecology. Additional work that evaluates the importance of winter and summer growth restriction, and their interaction, is needed before a comprehensive understanding of conifer tree ecophysiology will be possible.

  14. Can the CMIP5 models represent winter frontal precipitation?

    NASA Astrophysics Data System (ADS)

    Catto, J. L.; Jakob, C.; Nicholls, N.

    2015-10-01

    Much of the day-to-day variability of rainfall in the midlatitudes is controlled by the passage of extratropical cyclones and their related fronts. A good representation of fronts and their associated rainfall in climate models is essential to have confidence in future projections of midlatitude precipitation. An objective front identification method has been applied to the data from ERA-Interim and 18 Coupled Model Intercomparison Project, version 5 (CMIP5) models and the fronts linked with daily precipitation estimates to investigate how winter front-related precipitation is represented in the models. While the front frequency is well represented, the frequency of frontal precipitation is too high and the intensity is too low, thus adding little bias to the rainfall total. Although the intensity of the modeled frontal precipitation is too low, the intensity of other precipitation is even lower; thus, the ratio of frontal precipitation to total precipitation is higher in the models than in the reanalysis.

  15. Some Chinese folk prescriptions for wind-cold type common cold.

    PubMed

    Hai-Long, Zhai; Shimin, Chen; Yalan, Lu

    2015-07-01

    Although self-limiting, the common cold (g?n mào) is highly prevalent. There are no effective antivirals to cure the common cold and few effective measures to prevent it, However, for thousands years, Chinese people have treated the common cold with natural herbs, According to the traditional Chinese medicine (TCM) theory ( zh?ng y? l? lùn), the common cold is considered as an exterior syndrome, which can be further divided into the wind-cold type ( f?ng hán xíng), the wind-heat type ( f?ng rè xíng), and the summer heat dampness type ( sh? rè xíng). Since the most common type of common cold caught in winter and spring is the wind-cold type, the article introduced some Chinese folk prescriptions for the wind-cold type common cold with normal and weak physique, respectively. For thousands of years, Chinese folk prescriptions for the common cold, as complementary and alternative medicine (CAM; b? ch?ng y? tì dài y? xué), have been proven to be effective, convenient, cheap, and most importantly, safe. The Chinese folk prescriptions ( zh?ng guó mín ji?n ch? f?ng) for the wind-cold type common cold are quite suitable for general practitioners or patients with the wind-cold type common cold, to treat the disease. Of course, their pharmacological features and mechanisms of action need to be further studied. PMID:26151024

  16. Some Chinese folk prescriptions for wind-cold type common cold

    PubMed Central

    Hai-long, Zhai; Shimin, Chen; Yalan, Lu

    2015-01-01

    Although self-limiting, the common cold (??g?n mào) is highly prevalent. There are no effective antivirals to cure the common cold and few effective measures to prevent it, However, for thousands years, Chinese people have treated the common cold with natural herbs, According to the traditional Chinese medicine (TCM) theory (???? zh?ng y? l? lùn), the common cold is considered as an exterior syndrome, which can be further divided into the wind-cold type (??? f?ng hán xíng), the wind-heat type (??? f?ng rè xíng), and the summer heat dampness type (??? sh? rè xíng). Since the most common type of common cold caught in winter and spring is the wind-cold type, the article introduced some Chinese folk prescriptions for the wind-cold type common cold with normal and weak physique, respectively. For thousands of years, Chinese folk prescriptions for the common cold, as complementary and alternative medicine (CAM; ??????? b? ch?ng y? tì dài y? xué), have been proven to be effective, convenient, cheap, and most importantly, safe. The Chinese folk prescriptions (?????? zh?ng guó mín ji?n ch? f?ng) for the wind-cold type common cold are quite suitable for general practitioners or patients with the wind-cold type common cold, to treat the disease. Of course, their pharmacological features and mechanisms of action need to be further studied. PMID:26151024

  17. Corrugation crack front waves

    E-print Network

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

    2012-06-05

    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.

  18. Atypical occlusion process caused by the merger of a sea-breeze front and gust front

    NASA Astrophysics Data System (ADS)

    Abulikemu, Abuduwaili; Xu, Xin; Wang, Yuan; Ding, Jinfeng; Wang, Yan

    2015-10-01

    An atypical occlusion process that occurred in North China on 14 July 2011 is studied based on both observations and a real-data Weather Research and Forecasting (WRF) model simulation. The results show that this atypical occlusion process was significantly different from the traditional, synoptic-scale occlusion process that occurs within extratropical cyclones. It was caused by the merger of two cold-type mesoscale fronts. One of the fronts developed from the gust front of convective storms, while the other was a sea-breeze front. As the two fronts moved towards each other, the warm air between them was squeezed and separated from the surface. An atypical occluded front was formed when the two fronts merged, with the warm air forced aloft. This kind of occlusion is termed a "merger" process, different from the well-known "catch-up" and "wrap-up" processes. Moreover, local convection was found to be enhanced during the merger process, with severe convective weather produced in the merger area.

  19. When hot water freezes before cold

    E-print Network

    J. I. Katz

    2006-04-27

    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.

  20. When hot water freezes before cold

    E-print Network

    Katz, J I

    2006-01-01

    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.

  1. East Asian winter monsoon: results from eight AMIP models

    NASA Astrophysics Data System (ADS)

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

    This study evaluates simulations of the East Asian winter monsoon in eight GCMs that participated in the Atmospheric Model Intercomparison Project (AMIP). In addition to validating the mean state of the winter monsoon, the cold surge and its transient properties, which includes the frequency, intensity, preferred propagation tracks, and the evolution patterns of the surges, are examined. GCM simulated temporal distribution of the Siberian high and cold surges is also discussed. Finally, the forcing of the cold surges on the tropical surface wind and convection, along with their interannual variation is analyzed. The mean state of the winter monsoon is generally portrayed well in most of the models. These include the climatological position of the Siberian high, the 200 hPa divergent center, and the large-scale wind patterns at the surface and the 200 hPa. Models display a wide range of skill in simulating the cold surge and its transient properties. In some of the models, the simulated cold surge trajectory, intensity, frequency, propagation patterns and source regions are in general agreement with those from the observed. While in others, the models cannot adequately capture these observed characteristics. The temporal distribution of the Siberian high and cold surges were realistically reproduced in most GCMs. Most models were able to simulate the effect of the cold surges on the tropical surface wind, although a few models unrealistically generated subtropical southerly wind in the mid-winter. The relationship between cold surges and the tropical convection was not satisfactorily simulated in most models. The common discrepancies in the winter monsoon simulation can be attributed to many factors. In some models, the reason is directly related to the improper location of the large-scale convective center near the western Pacific. The satisfactory simulations of the monsoon circulation and the cold surges are partly due to the topographical characteristics of the East Asian continent, i.e., the Tibetan Plateau to the west and the oceans to the east. The correct simulation of the interannual variation of the surface wind near the South China Sea (SCS) and the maritime continent is a demanding task for most of the models. This will require adequate simulations of many aspects, including tropical convection, the Siberian cold dome, the extratropical-tropical linkage, and the air-sea interaction. The discrepancies noted here furnish a guide for the continuing improvement of the winter monsoon simulations. Improved simulations will lead to an adequate delineation of the surface wind and convection near the maritime continent, which is essential for portraying the winter monsoon forcing in a coupled model.

  2. A computer model for predicting grapevine cold hardiness

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We developed a robust computer model of grapevine bud cold hardiness that will aid in the anticipation of and response to potential injury from fluctuations in winter temperature and from extreme cold events. The model uses time steps of 1 day along with the measured daily mean air temperature to ca...

  3. Clouds in the Winter Arctic Tropopause Region

    NASA Technical Reports Server (NTRS)

    Pfister, Leonhard; Selkirk, Henry; Anderson, Bruce; Podolske, James; Sachse, Glen; Avery, Melody; Schoeberl, Mark; Hipskind, R. Stephen (Technical Monitor)

    2002-01-01

    Water vapor in the winter arctic tropopause region is important because, after the tropical tropopause region, the winter arctic tropopause has the coldest temperatures in the tropospheric northern hemisphere. This suggests the potential for cloud formation that can remove water vapor from a part of the atmosphere where radiatively active gases (such as water) exert a disproportionate influence on the earth's radiation budget. Previous work by the same authors has shown that this cloud formation extends into the stratosphere, with 20% of the parcels having ozone values of 300-350 ppbv experiencing ice saturation in any given 10 day period period during the late winter. In fact, temperatures are cold enough that 5-10% of the parcels experience saturation even if the water content is below the prevailing stratospheric value of 5 ppmv. This work describes a case study of clouds observed by aircraft near the winter arctic tropopause during the SAGE Ozone Loss and Validation Experiment (SOLVE). This provided a unique opportunity to examine dehydration processes in this region since in situ water, tracer, cloud particle, and meteorological data were all available simultaneously. During this period, temperatures were cold enough at the tropopause to produce saturation mixing ratios of 3-4 ppmv. Thus, clouds were actually observed within the stratosphere. Back trajectories indicate that the air in these clouds came from lower latitudes and altitudes. The study describes the nature of the clouds, the history of the air, and the possible implications for the upper tropospheric water budget.

  4. Dehydration in the Winter Arctic Tropopause Region

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

    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.

  5. Cold injuries.

    PubMed

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

    2005-01-01

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

  6. Cold urticaria.

    PubMed

    Claudy, A

    2001-11-01

    Cold urticaria is one form of urticaria that may be associated with other forms of physical urticarias. Frequency is generally estimated at two or three per 100. The triggering effect of cold is found at history taking in most of the cases. The urticaria is usually superficial, and more rarely associated with deep and/or mucosal urticaria. The diagnosis is based on history taking and the ice cube test. An exhaustive search for an etiologic factor is often unfruitful, and the presence of a cryopathy should lead to a complete work-up. Therapy of cold urticaria may prove to be difficult. In patients with secondary cold urticaria, underlying disease must be treated in order to resolve the skin symptoms. H1-antihistamines can be used but the clinical responses are highly variable. Short-time treatment with low concentration corticosteroids suppresses the symptoms only partially and temporarily. In patients who do not respond to previous treatments, induction of cold tolerance may be proposed but the procedure is difficult to carry out in daily life over an extended period. Key word: cryoglobulins. PMID:11764302

  7. ampersand | FALL&WINTER 2014 | 1 TEXAS TECH UNIVERSITY | COLLEGE OF VISUAL & PERFORMING ARTS | FALL&WINTER 2014

    E-print Network

    Rock, Chris

    experienced a new, more expansive global perspective. In The World Is A Campus, we get a glimpse of the varied Jared Strange 2 | ampersand | FALL&WINTER 2013 Front Cover Texas Tech's University Dance Company getting ................................................................... 27 THE VERNACULAR MUSIC CENTER Living in the World of Music THE WORLD IS A CAMPUS From Trinidad

  8. Anti-correlation of summer/winter monsoons?

    PubMed

    Zhang, De'er; Lu, Longhua

    2007-11-15

    On the basis of the anti-correlation of their palaeoclimatic proxy for the strength of the East Asian winter monsoon from Lake Huguang Maar, China, with stalagmite records of the strength of the summer monsoon, Yancheva et al. claim that the strengths of the summer and winter monsoons are anti-correlated on a decadal timescale. They argue that the summer rainfall deficit during ad 700-900 that they infer from their evidence of a stronger winter monsoon, in conjunction with a Tanros battle, led to the collapse of the Tang dynasty (ad 618-907). Using historical climate records, we show here that most cold winters during ad 700-900 were associated with relatively wet summers, indicating that the strengths of the winter and summer monsoons were not negatively correlated during this period. PMID:18004320

  9. Fronts, fish, and predators

    NASA Astrophysics Data System (ADS)

    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

    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.

  10. Impact of declining Arctic sea ice on winter snowfall

    PubMed Central

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

    2012-01-01

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

  11. Role of mixed layer depth in surface frontogenesis: The Agulhas Return Current front

    NASA Astrophysics Data System (ADS)

    Tozuka, Tomoki; Cronin, Meghan F.

    2014-04-01

    Air-sea interaction processes that modify the sea surface temperature (SST) front in the Agulhas Return Current region (between 40°E and 55°E) during austral summer and winter are examined using observational data and output from a high-resolution ocean general circulation model. While the air-sea heat flux frontal variations tend to relax the SST front, the frontolysis is amplified (damped) in summer (winter) when frontal variations in the mixed layer depth (MLD) are incorporated. The stronger (weaker) frontolysis associated with the MLD variations is due to the fact that the warming (cooling) by the surface heat flux is amplified south of the front where the MLD is shallower and is reduced north of the front where the MLD is deeper. This study is the first to show that the MLD variations play an important role in affecting the strength of the SST front.

  12. Two cold-season derechoes in Europe

    NASA Astrophysics Data System (ADS)

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

    2011-06-01

    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.

  13. Negative Ion Density Fronts

    SciTech Connect

    Igor Kaganovich

    2000-12-18

    Negative ions tend to stratify in electronegative plasmas with hot electrons (electron temperature Te much larger than ion temperature Ti, Te > Ti ). The boundary separating a plasma containing negative ions, and a plasma, without negative ions, is usually thin, so that the negative ion density falls rapidly to zero-forming a negative ion density front. We review theoretical, experimental and numerical results giving the spatio-temporal evolution of negative ion density fronts during plasma ignition, the steady state, and extinction (afterglow). During plasma ignition, negative ion fronts are the result of the break of smooth plasma density profiles during nonlinear convection. In a steady-state plasma, the fronts are boundary layers with steepening of ion density profiles due to nonlinear convection also. But during plasma extinction, the ion fronts are of a completely different nature. Negative ions diffuse freely in the plasma core (no convection), whereas the negative ion front propagates towards the chamber walls with a nearly constant velocity. The concept of fronts turns out to be very effective in analysis of plasma density profile evolution in strongly non-isothermal plasmas.

  14. 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

  15. Membrane stability of winter wheat plants exposed to subzero temperatures for variable lengths of time

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ability to survive episodes of subfreezing temperature is essential to winter wheat. Fully cold-acclimated plants of six lines of winter wheat were exposed to -12, -14, -16 or -18° C, four 1-5 hours. Electrolyte leakage and plant survival were used to assess damage to the plants. Plants exposed ...

  16. Winter Edition: Vol.10 ED.1, 2014 TRANSACTION OF LOST SOULS

    E-print Network

    Burgstaller, Bernd

    Winter Edition: Vol.10 ED.1, 2014 TRANSACTION OF LOST SOULS Helping North Korea Is China Baring its Common Curriculum as well as within the Techno-Art Division. This spring we will see the launching of UIC this Dean's Letter in the cold of winter, I look forward to the spring, and the blooming of the arts in the

  17. Light Front Nuclear Theory

    E-print Network

    Gerald A. Miller

    2001-09-07

    High energy scattering experiments involving nuclei are typically analyzed in terms of light front variables. The desire to provide realistic,relativistic wave functions expressed in terms of these variables led me to try to use light front dynamics to compute nuclear wave functions. Here calculations of infinite nuclear matter in the mean field approximation and also in a light front version of Bruckner theory which includes NN correlations are reviewed. Applications of these wave functions to nuclear deep inelastic scattering and Drell-Yan processes are discussed. We find that relativistic mean field theory produces no EMC binding effect.

  18. Hot, Cold, and Really Cold.

    ERIC Educational Resources Information Center

    Leyden, Michael

    1997-01-01

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

  19. 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...

  20. Winter Art Education Project

    ERIC Educational Resources Information Center

    Jokela, Timo

    2007-01-01

    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…

  1. Bison in Winter

    USGS Multimedia Gallery

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

  2. Intelligent Front Ends 

    E-print Network

    Bundy, Alan

    1984-01-01

    An intelligent front end is a user-friendly interface to a software package, which uses Artificial Intelligence techniques to enable the user to interact with the computer using his/her own terminology rather than that ...

  3. 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...

  4. Winter Injury In Young Montmorency Cherries By Jim Nugent

    E-print Network

    freezing conditions occurred with snow on the ground. The snow reflects sunlight onto the trunk, warming freezing winter temperatures are followed by a major cold event. It affects only young trees because weather station to a seriously damaged orchard in 2004 recorded 22 days of daily highs above freezing

  5. Coastal circulation off southern Tamaulipas and northern Veracruz, western Gulf of Mexico, during winter 2012-2013

    NASA Astrophysics Data System (ADS)

    Rivas, David

    2015-04-01

    Four months of observations from a near-coastal mooring deployed off southern Tamaulipas-northern Veracruz coast (western Gulf of Mexico) during winter 2012-2013 provides velocity, temperature, and salinity series in a region where apparently no in-situ measurements have been formally reported. The measurements show numerous events of intense alongshore velocities with magnitudes typically exceeding 80 cm/s, associated with intensified winds associated with the cold fronts invading the western Gulf during fall-winter, via coastal-trapped motions coming from northern locations. These motions must induce a coastal jet that modulates the regional along-shelf transports. This notion is corroborated by an analytical coastal-trapped wave (CTW) model which explains most of the variability of the sea level and the alongshore barotropic velocity observed in the mooring. Several near-inertial signals exceeding 50 cm/s are also observed at the surface levels. These high-frequency (HF) signals occur several hours before the intensified currents induced by the winds. Comparison between HF series of water velocity and wind suggests a direct influence of the winds affecting the NW Gulf (northern Tamaulipas/southern Texas) about 6-9 hours before the occurrence of the HF currents at the mooring. These near-inertial events induce a vigorous mixing of the local riverine discharge.

  6. Logistic Regression Analysis of the Response of Winter Wheat to Components of Artificial Freezing Episodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Improvement of cold tolerance of winter wheat (Triticum aestivum L.) through breeding methods has been problematic. A better understanding of how individual wheat cultivars respond to components of the freezing process may provide new information that can be used to develop more cold tolerance culti...

  7. Logistic regression analysis of the response of winter wheat to components of artificial freezing episodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Improvement of cold tolerance of winter wheat (Triticum aestivum L.) through breeding methods has been problematic. A better understanding of how individual wheat cultivars respond to components of the freezing process may provide new information that can be used to develop more cold tolerance culti...

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

    PubMed Central

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

    2015-01-01

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

  9. Cold tolerance of red drum (Sciaenops ocellatus) and thermal-refuge technology to protect this species from cold-kill in aquaculture ponds 

    E-print Network

    Dorsett, Paul Wesley

    1994-01-01

    drum culture ponds at Redfish Unlimited, Palacios, Texas, during the winters of 1991-92 and 1992-93. Although red drum in the ponds at Palacios were not threatened by cold during either of these mild winters, the thermodynamic efficiency of the two...

  10. Heavy ion acceleration at dipolarization fronts in planetary magnetotails

    NASA Astrophysics Data System (ADS)

    Greco, A.; Artemyev, A.; Zimbardo, G.

    2015-10-01

    Transient reconnection events in planetary magnetotails give rise to fast plasma jets, whose leading edges are called dipolarization fronts. We perform a test particle simulation of the acceleration of several ion species (H+, He+, and O+) in a 2-D model of dipolarization fronts. We study the dependence of the acceleration on parameters of the model, finding, e.g., that the average ion energy increases with the front velocity and with the initial injection energy. When the ion species are initially cold, O+ ions get the largest amount of average energy. Conversely, when the injection energy of O+ ions is increased, their average energy gain does not exceed that of the lighter species, suggesting that ion energization at local dipolarization fronts strongly depends on the initial particle gyroradius. Further, the energy gained by the most energetic fraction of particles scales approximately as the square root of the mass ratio.

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

    USGS Publications Warehouse

    Banks, Richard C.

    2011-01-01

    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.

  12. American woodcock winter distribution and fidelity to wintering areas

    USGS Publications Warehouse

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

    1990-01-01

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

  13. Link between warm conveyor belts and fronts and the impact on extreme rainfall

    NASA Astrophysics Data System (ADS)

    Catto, Jennifer; Madonna, Erica; Joos, Hanna; Wernli, Heini; Rudeva, Irina; Simmonds, Ian

    2015-04-01

    The various dynamical features within extratropical cyclones have been shown to be very important for the precipitation produced by these systems. Warm conveyor belts (WCBs) and fronts are both strongly associated with total and extreme precipitation in the midlatitudes. Here we have brought together two automated feature detection methods to answer questions on the frequency of matching of fronts and WCBs, whether this depends on frontal type or height of WCB, and the impact this matching has on extreme precipitation events. We find that WCBs and fronts are strongly related in the midlatitudes - annually 60% of WCBs are associated with cold fronts and around 50% associated with warm fronts, and a fairly large proportion associated with both together. The frequency of linked WCBs and fronts shows a strong seasonal cycle. In some regions warm fronts are more strongly linked to WCBs than cold fronts. To the east of Australia in particular, there are often WCBs not associated with fronts at all. Fronts that co-occur with a WCB are much more likely to produce an extreme precipitation event.

  14. Assessment of cold stress in outdoor work.

    PubMed

    Anttonen, H; Virokannas, H

    1994-01-01

    The evaluation of cold stress in working life was done in 13, mainly outdoor, occupations and 143 workers using local temperatures, body cooling and thermal sensations. The subjects in the study were young, healthy men and they wore the type of winter clothing generally used in those ambient temperatures (+6...-29 degrees C), for in a work load of from 112 to 480 W. Local temperatures on finger skin indicated that manual dexterity was often reduced in outdoor work. A risk of frostbite was frequently found on the cheek and the wind chill index predicted the risk quite well. Body cooling was often temporarily too high when measured by heat debt and mean skin temperature. Thermal sensations were cool or cold occasionally in 28% of the workers interviewed. The insulation of clothing worn was often lower than the IREQmin-value recommends. The results showed that in outdoor work in winter time cold stress frequently reduced (70%) working ability at least for a short period. Mean skin temperature seems to be, in practice, a useful indicator for body cooling and the IREQmin-value was suitable, especially in light work, to indicate body cooling. A very sensitive factor for the expression of cold stress was finger temperature, at least as an indicator of finger dexterity. Due to the adverse health effects found the cold stress should also be evaluated more systematically in occupational health and safety with health examinations, with protective clothing and technical preventive means. PMID:8049001

  15. FALL WINTER SPRING FALL WINTER SPRING FALL WINTER SPRING SUMMER FALL WINTER SPRING SUMMER FALL WINTER SPRING CALC CALC LIN CALC DIF STAT

    E-print Network

    Bertini, Robert L.

    FALL WINTER SPRING FALL WINTER SPRING FALL WINTER SPRING SUMMER FALL WINTER SPRING SUMMER FALL WINTER SPRING CALC CALC LIN CALC DIF STAT I II ALG IV EQ I MTH MTH MTH MTH MTH 451CM 251 CHEM 252 261 254

  16. The Winter Is Past.

    ERIC Educational Resources Information Center

    Busch, Phyllis S.

    1985-01-01

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

  17. Winter Weather: Indoor Safety

    MedlinePLUS

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

  18. Observations of the Winter Thermal Structure of Lake Superior

    NASA Astrophysics Data System (ADS)

    Titze, Daniel James

    Moored thermistor strings that span the water column have been deployed at up to seven locations throughout Lake Superior from 2005 through present, producing a unique year-round record of the thermal structure of a large lake. This extensive temperature record reveals significant interannual and spatial variability in Lake Superior's winter heat content, thermocline depth, and phenology. Of particular mention is a stark contrast in thermal structure between the cold, icy winter of 2009 and the much warmer winter of 2012, during which especially strong and weak negative stratification was observed, respectively. Significant interannual and spatial variability was also observed in Lake Superior ice cover, as shown through data extracted from Ice Mapping System satellite imagery (NOAA/NESDIS 2004). When water column heat content was estimated from temperature data and analyzed in concert with lake ice-cover data, it was found that ice cover can inhibit heat flux between the lake and the atmosphere, and that spatial variability in ice cover can translate into spatial variability in end-of-winter heat content. Such variability in end-of-winter heat content is found to be preserved through the spring warming season, and is strongly correlated with variability in the timing of the onset of summer stratification, with regions that have warmer end-of-winter water columns stratifying earlier than regions with colder end-of-winter water-columns.

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

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

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

  20. Arctic-Winter Climatology and Radiative Effects of Clouds and Aerosols Based on Lidar and Radar Measurements at PEARL

    E-print Network

    Eloranta, Edwin W.

    Measurements at PEARL T. Ayash, J.-P. Blanchet and E. W. Eloranta During the cold and dark Polar winter months Laboratory (PEARL) at Eureka, Nunavut by an Automated High Spectral Resolution Lidar (AHSRL

  1. Nuclear Winter: The implications for civil defense

    SciTech Connect

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

    1987-01-01

    ''Nuclear Winter'' is the term given to hypothesized cooling in the northern hemisphere following a nuclear war due to injection of smoke from burning cities into the atmosphere. The voluminous literature on this subject produced since the original paper in 1983 by Turco, Toon, Ackerman, Pollack, and Sagen (TTAPS) has been reviewed. The widespread use of 3-dimensional global circulation models have resulted in reduced estimates of cooling; 15 to 25/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.

  2. 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

  3. 3. VIEW NORTH, SOUTHWEST FRONT, SOUTHEAST SIDE Front and side ...

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

    3. VIEW NORTH, SOUTHWEST FRONT, SOUTHEAST SIDE Front and side elevation. Note gasoline sign post added. Flush store window not altered, 1900 clapboard siding and panelling remaining. - 510 Central Avenue (Commercial Building), Ridgely, Caroline County, MD

  4. Front Range Branch Officers

    NASA Astrophysics Data System (ADS)

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

  5. Stories from the Front.

    ERIC Educational Resources Information Center

    Melnick, Blake

    2002-01-01

    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…

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

    NASA Astrophysics Data System (ADS)

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

    2006-09-01

    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.

  7. Study of a Wind Front over the Northern South China Sea Generated by the Freshening of the North-East Monsoon

    NASA Astrophysics Data System (ADS)

    Alpers, Werner; Wong, Wai Kin; Dagestad, Knut-Frode; Chan, Pak Wai

    2015-10-01

    Wind fronts associated with cold-air outbreaks from the Chinese continent in the winter are often observed over the northern South China Sea and are well studied. However, wind fronts caused by another type of synoptic setting, the sudden increase or freshening of the north-east monsoon, which is caused by the merging of two anticyclonic regions over the Chinese continent, are also frequently encountered over the northern South China Sea. For the first time, such an event is investigated using multi-sensor satellite data, weather radar images, and a high-resolution atmospheric numerical model. It is shown that the wind front generated by the freshening of the north-east monsoon is quite similar to wind fronts generated by cold-air outbreaks. Furthermore, we investigate fine-scale features of the wind front that are visible on synthetic aperture radar (SAR) images through variations of the small-scale sea-surface roughness. The SAR image was acquired by the Advanced SAR of the European Envisat satellite over the South China Sea off the coast of Hong Kong and has a resolution of 150 m. It shows notches (dents) in the frontal line and also radar signatures of embedded rain cells. This (rare) SAR image, together with a quasi-simultaneously acquired weather radar image, provide excellent data with which to test the performance of the pre-operational version of the Atmospheric Integrated Rapid-cycle (AIR) forecast model system of the Hong Kong Observatory with respect to modelling rain cells at frontal boundaries. The calculations using a horizontal resolution with 3-km resolution show that the model reproduces quite well the position of the notches where rain cells are generated. The model shows further that at the position of the notches the vorticity of the airflow is increased leading to the uplift of warmer, moister air from the sea-surface to higher levels. With respect to the 10-km resolution model, the comparison of model data with the near-surface wind field derived from the SAR image shows that the AIR model overestimates the wind speed in the lee of the coastal mountains east of Hong Kong, probably due to the incorrect inclusion of the coastal topography.

  8. Farmers’ Market Expands to Offer Products in Winter | Poster

    Cancer.gov

    By Carolynne Keenan, Contributing Writer The 2013 National Cancer Institute (NCI) at Frederick Farmers’ Market regular season may have closed, but that doesn’t mean customers who want fresh produce, handmade crafts, and other homemade goodies from local vendors are out of luck. Winter Markets, which began Jan. 7, will be held every other Tuesday, from 11 a.m. to 1 p.m., in front of Building 549 or in the Café Room, depending on the weather.

  9. Coping with Cold Sores

    MedlinePLUS

    ... How the Body Works Main Page Coping With Cold Sores KidsHealth > Kids > Illnesses & Injuries > Aches, Pains & Injuries > ... sore." What's that? Adam wondered. What Is a Cold Sore? Cold sores are small blisters that is ...

  10. Cough & Cold Medicine Abuse

    MedlinePLUS

    ... Self Smart Snacking Losing Weight Safely Cough & Cold Medicine Abuse KidsHealth > Teens > Drugs & Alcohol > Drugs > Cough & Cold ... DXM Why Do People Use Cough and Cold Medicines to Get High? There's an ingredient in many ...

  11. Air pollution episodes associated with East Asian winter monsoons.

    PubMed

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

    2011-11-01

    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

  12. Expansion of a cold non-neutral plasma slab

    SciTech Connect

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

    2014-12-15

    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.

  13. Expansion of a cold non-neutral plasma slab

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

    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.

  14. Cover Crop Biomass and Corn Yield Following 13 Rye, Wheat, and Triticale Cultivars Used as Winter Cover Crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Winter cover crops have the potential to reduce nitrate leaching and erosion in corn-soybean rotations in the upper Midwest. The cover crop growing season between harvest and planting of corn and soybean, however, is short and cold. Additionally, previous studies in Iowa have indicated that winter r...

  15. Field efficacy of wintertime insecticide applications against greenbugs, Schizaphis graminum (Rondani) (Hemiptera: Aphididae), on winter wheat (Triticum aestivum L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Winter wheat producers in Oklahoma often combine an insecticide with a top-dress application of nitrogen during late fall or winter to control existing greenbug populations. We evaluated the efficacy of three classes of insecticides applied in cold weather conditions ranging from -13.3 degrees to 2...

  16. Cold tolerance of the montane Sierra leaf beetle, Chrysomela aeneicollis.

    PubMed

    Boychuk, Evelyn C; Smiley, John T; Dahlhoff, Elizabeth P; Bernards, Mark A; Rank, Nathan E; Sinclair, Brent J

    2015-10-01

    Small ectothermic animals living at high altitude in temperate latitudes are vulnerable to lethal cold throughout the year. Here we investigated the cold tolerance of the leaf beetle Chrysomela aeneicollis living at high elevation in California's Sierra Nevada mountains. These insects spend over half their life cycle overwintering, and may therefore be vulnerable to winter cold, and prior studies have demonstrated that survival is reduced by exposure to summertime cold. We identify overwintering microhabitat of this insect, describe cold tolerance strategies in all life stages, and use microclimate data to determine the importance of snow cover and microhabitat buffering for overwinter survival. Cold tolerance varies among life history stages and is typically correlated with microhabitat temperature: cold hardiness is lowest in chill-susceptible larvae, and highest in freeze-tolerant adults. Hemolymph osmolality is higher in quiescent (overwintering) than summer adults, primarily, but not exclusively, due to elevated hemolymph glycerol. In nature, adult beetles overwinter primarily in leaf litter and suffer high mortality if early, unseasonable cold prevents them from entering this refuge. These data suggest that cold tolerance is tightly linked to life stage. Thus, population persistence of montane insects may become problematic as climate becomes more unpredictable and climate change uncouples the phenology of cold tolerance and development from the timing of extreme cold events. PMID:26231921

  17. Thermal Fronts in Solar Flares

    NASA Astrophysics Data System (ADS)

    Karlický, Marian

    2015-12-01

    We studied the formation of a thermal front during the expansion of hot plasma into colder plasma. We used a three-dimensional electromagnetic particle-in-cell model that includes inductive effects. In early phases, in the area of the expanding hot plasma, we found several thermal fronts, which are defined as a sudden decrease of the local electron kinetic energy. The fronts formed a cascade. Thermal fronts with higher temperature contrast were located near plasma density depressions, generated during the hot plasma expansion. The formation of the main thermal front was associated with the return-current process induced by hot electron expansion and electrons backscattered at the front. A part of the hot plasma was trapped by the thermal front while another part, mainly with the most energetic electrons, escaped and generated Langmuir and electromagnetic waves in front of the thermal front, as shown by the dispersion diagrams. Considering all of these processes and those described in the literature, we show that anomalous electric resistivity is produced at the location of the thermal front. Thus, the thermal front can contribute to energy dissipation in the current-carrying loops of solar flares. We estimated the values of such anomalous resistivity in the solar atmosphere together with collisional resistivity and electric fields. We propose that the slowly drifting reverse drift bursts, observed at the beginning of some solar flares, could be signatures of the thermal front.

  18. Winter Camp, Texas 

    E-print Network

    Unknown

    2011-09-05

    at the Spur Station SUMMARY Winter maintenance experiments were conducted with 1,034 steer calves at the Spur station dur. ing the 14-year period from the fall of 1941 to the spring of 1955. Results of these comparative trials, in most instances, were... based on 3 or more years of work. Roughages used in wintering steer calves weighing 325 to 400 pounds were wheat pasture, natire grass, sorghum silage, bundle feeds and stalk fields. Protein supplements were fed with sorghum sil- age and chopped...

  19. Radiative thermal conduction fronts

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

    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.

  20. A numerical investigation of the severe thunderstorm gust front

    NASA Technical Reports Server (NTRS)

    Mitchell, K. E.; Hovermale, J. B.

    1977-01-01

    The structure of the thunderstorm gust front is investigated by a nonhydrostatic, two-dimensional (x,z) numerical model. In the model, which is dry, the production of negatively buoyant air by evaporation is parameterized via an externally imposed, local-cooling function. This parameterization sustains a steady cold downdraft, which drives the surface outflow and associated gust front. It is shown that two dominant factors influencing gust front structure in the vertical plane are the solenoidal field coincident with the front and surface friction, modeled by means of a simple bulk aerodynamic drag formulation. The circulation theorem is invoked to illustrate how solenoidal accelerations oppose the deceleration by surface friction. After the onset of a downdraft in the model, these opposing tendencies soon reach a balance. Thus, following a brief transient stage, the model gust front exhibits a persistent configuration as it propagates rapidly forward. The essential features of this configuration are examined and compared with both tower observations of gust fronts and laboratory models of gravity currents.

  1. A numerical investigation of severe thunderstorm gust fronts

    NASA Technical Reports Server (NTRS)

    Mitchell, K. E.

    1975-01-01

    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.

  2. Identification, characteristics and seasonal evolution of surface thermal fronts in the Argentinean Continental Shelf

    NASA Astrophysics Data System (ADS)

    Rivas, Andrés L.; Pisoni, Juan Pablo

    2010-01-01

    The location and seasonal variability of surface thermal fronts along the Argentinean Continental Shelf (38-55°S) were studied using 18 years (1985-2002) of sea surface temperature (SST) satellite data. Monthly SST gradients were calculated and a threshold was used to identify frontal pixels. Frontal areas were classified into 4 zones according to their seasonal evolution and the main forcings leading to the front's formation were identified for each group. The shelf break front was easily detected due to the large number of frontal pixels in the region and its high mean gradient values. This front showed a marked annual cycle and relatively constant position associated to the bottom slope; it tended to be located where the core of the Malvinas current is closest to the shelf. Tidal fronts also showed a strong annual cycle, being detected in three well-defined regions during spring and summer. Along the coasts of Tierra del Fuego and Santa Cruz, the combination of strong tidal mixing and low-salinity coastal plumes led to semi-annual seasonal cycles of frontal intensity and persistence that showed a relative maximum in winter. A similar behavior (semi-annual) was found at the coast off the Buenos Aires Province. There, the coastal dilution and the bathymetric gradient generated near-coastal fronts that changed direction seasonally. In the northern mid-shelf, a front linked to the intrusion of warm waters formed in the San Matías Gulf was identified during the winter.

  3. Anthropology Major Effective Winter 2016

    E-print Network

    Awtar, Shorya

    Anthropology Major Effective Winter 2016 Prerequisites to the major: None, but ANTHRCUL 101 at least one course in each of the following subfields: 1. Anthropological Archaeological Beginning in Winter 2016, the anthropological archaeological course requirements are revised to include only

  4. Winter Playscape Dreaming

    ERIC Educational Resources Information Center

    Keeler, Rusty

    2006-01-01

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

  5. Teaching Ecology in Winter.

    ERIC Educational Resources Information Center

    Clearing: Nature and Learning in the Pacific Northwest, 1984

    1984-01-01

    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…

  6. Recent trends in winter temperature extremes in eastern China and their relationship with the Arctic Oscillation and ENSO

    NASA Astrophysics Data System (ADS)

    Chen, Shangfeng; Chen, Wen; Wei, Ke

    2013-11-01

    Interannual variations in the number of winter extreme warm and cold days over eastern China (EC) and their relationship with the Arctic Oscillation (AO) and El Niño-Southern Oscillation (ENSO) were investigated using an updated temperature dataset comprising 542 Chinese stations during the period 1961-2011. Results showed that the number of winter extreme warm (cold) days across EC experienced a significant increase (decrease) around the mid-1980s, which could be attributed to interdecadal variation of the East Asian Winter Monsoon (EAWM). Probability distribution functions (PDFs) of winter temperature extremes in different phases of the AO and ENSO were estimated based on Generalized Extreme Value Distribution theory. Correlation analysis and the PDF technique consistently demonstrated that interannual variation of winter extreme cold days in the northern part of EC (NEC) is closely linked to the AO, while it is most strongly related to the ENSO in the southern part (SEC). However, the number of winter extreme warm days across EC has little correlation with both AO and ENSO. Furthermore, results indicated that, whether before or after the mid-1980s shift, a significant connection existed between winter extreme cold days in NEC and the AO. However, a significant connection between winter extreme cold days in SEC and the ENSO was only found after the mid-1980s shift. These results highlight the different roles of the AO and ENSO in influencing winter temperature extremes in different parts of EC and in different periods, thus providing important clues for improving short-term climate prediction for winter temperature extremes.

  7. Mechanisms for convection triggering by cold pools

    E-print Network

    Torri, Giuseppe; Tian, Yang

    2015-01-01

    Cold pools are fundamental ingredients of deep convection. They contribute to organizing the sub-cloud layer and are considered key elements in triggering convective cells. It was long known that this could happen mechanically, through lifting by the cold pools' fronts. More recently, it has been suggested that convection could also be triggered thermodynamically, by accumulation of moisture around the edges of cold pools. A method based on Lagrangian tracking is here proposed to disentangle the signatures of both forcings and quantify their importance in a given environment. Results from a simulation of radiative-convective equilibrium over the ocean show that parcels reach their level of free convection through a combination of both forcings, each being dominant at different stages of the ascent. Mechanical forcing is an important player in lifting parcels from the surface, whereas thermodynamic forcing reduces the inhibition encountered by parcels before they reach their level of free convection.

  8. 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...

  9. COLD TEMPERATURE MOTOR VEHICLE EMISSIONS TESTING IN ALASKA

    EPA Science Inventory

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

  10. Is the OJIP Test a Reliable Indicator of Winter Hardiness and Freezing Tolerance of Common Wheat and Triticale under Variable Winter Environments?

    PubMed Central

    Rapacz, Marcin; Sasal, Monika; Kalaji, Hazem M.; Ko?cielniak, Janusz

    2015-01-01

    OJIP analysis, which explores changes in photosystem II (PSII) photochemical performance, has been used as a measure of plant susceptibility to stress. However, in the case of freezing tolerance and winter hardiness, which are highly environmentally variable, the use of this method can give ambiguous results depending on the species as well as the sampling year and time. To clarify this issue, we performed chlorophyll fluorescence measurements over three subsequent winters (2010/11, 2011/12 and 2012/13) on 220 accessions of common winter wheat and 139 accessions of winter triticale. After freezing, leaves were collected from cold-acclimated plants in the laboratory and field-grown plants. Observations of field survival in seven locations across Poland and measurements of freezing tolerance of the studied plants were also recorded. Our results confirm that the OJIP test is a reliable indicator of winter hardiness and freezing tolerance of common wheat and triticale under unstable winter environments. Regardless of species, the testing conditions giving the most reliable results were identical, and the reliability of the test could be easily checked by analysis of some relationships between OJIP-test parameters. We also found that triticale is more winter hardy and freezing tolerant than wheat. In addition, the two species were characterized by different patterns of photosynthetic apparatus acclimation to cold. PMID:26230839

  11. Winter Wilderness Travel and Camping.

    ERIC Educational Resources Information Center

    Gilchrest, Norman

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

  12. On the long-term interannual variability of the east Asian winter Rosanne D'Arrigo,1

    E-print Network

    , dramatic drops in tem- perature (cold surges) originating in the SH source region penetrate eastern China significantly with the SH. These two indices show common modes of variation on the biennial (2­3 year) time climate [Zhang et al., 1997; Jhun and Lee, 2004]. Strong EAWMs are linked to cold winter conditions over

  13. Development- and cold-regulated accumulation of cold shock domain proteins in wheat.

    PubMed

    Radkova, Mariana; Vítámvás, Pavel; Sasaki, Kentaro; Imai, Ryozo

    2014-04-01

    Cold shock domain (CSD) proteins, or Y-box proteins, are nucleic acid-binding proteins that are widely distributed from bacteria to higher plants and animals. Bacterial CSD proteins play an essential role in cold adaptation by destabilizing RNA secondary structures. WHEAT COLD SHOCK DOMAIN PROTEIN 1 (WCSP1) shares biochemical functions with bacterial CSD proteins and is possibly involved in cold adaptation. In this study, the temporal and spatial distribution of the wheat cold shock domain protein family (WCSPs) was serologically characterized with regard to plant development and cold adaptation. Four WCSP genes were identified through database analysis and were classified into three classes based on their molecular masses and protein domain structures. Class I (20 kD) and class II (23 kD) WCSPs demonstrated a clear pattern of accumulation in root and shoot meristematic tissues during vegetative growth. In response to cold, marked increases in WCSP levels were observed but the pattern of accumulation differed by tissue. Accumulation of WCSPs in crown tissue during cold acclimation was observed in the winter cultivar 'Chihokukomugi' but not in the spring cultivar 'Haruyutaka', suggesting a possible function for WCSPs in cold acclimation. During flower and seed development, protein levels of class I and class II WCSPs remained high. The class III WCSP (27 kD) was detected only during seed development. The highest level of class III WCSP accumulation was observed at the milky seed stage. Together, the results of this study provide a view of CSD protein accumulation throughout the life cycle of wheat and suggest that WCSPs function differentially in plant development and cold adaptation. PMID:24534004

  14. Cold Signaling and Cold Response in Plants

    PubMed Central

    Miura, Kenji; Furumoto, Tsuyoshi

    2013-01-01

    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

  15. Mesoscale numerical simulations of heavy nocturnal rainbands associated with coastal fronts in the Mediterranean Basin

    NASA Astrophysics Data System (ADS)

    Mazon, J.; Pino, D.

    2014-05-01

    Three offshore rainbands associated with nocturnal coastal fronts formed near the Israeli coastline, the Gulf of Genoa and on the northeastern coast of the Iberian Peninsula, are simulated using version 3.3 of the WRF-ARW mesoscale model in order to study the dynamics of the atmosphere in each case. The simulations show coastal fronts producing relatively high (in comparison with some other similar rainbands) 1 and 10 h accumulated precipitations that formed in the Mediterranean Basin. According to these simulations, the coastal fronts that formed near the Israeli coastline and over the Gulf of Genoa are quasi-stationary, while the one that formed on the northeastern coast of the Iberian Peninsula moves away from the coast. For the three events, we evaluate and intercompare some parameters related to convective triggering, deceleration induced by the cold pool in the upstream flow, and the blockage that the cold coastal front offers to the warmer maritime air mass.

  16. Morphological instability of failure fronts

    SciTech Connect

    Grinfeld, M.A.; Schoenfeld, S.E.; Wright, T.W.

    2006-03-06

    There are various observations and experiments showing that, in addition to standard shock-wave fronts, which propagate with high trans-sonic velocities, some other much slower wave fronts can propagate within substance undergoing intensive damage. These moving fronts propagate within intact substance leaving behind them intensively damaged substance. These fronts were coined as failure waves. The failure waves can be modeled differently--in this letter they are modeled as sharp interfaces separating two states: the intact and comminuted states. Several penetration experiments with transparent glasses and ceramics have shown that failure fronts have an extremely rough morphology. We suggest a simple thermodynamic theory which allows interpreting appearance of the roughness as a manifestation of morphological instability of failure fronts. For the case of isotropic phases the instability criterion is presented in explicit form.

  17. From the front

    SciTech Connect

    Price, Stephen

    2009-01-01

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

  18. Winter Cardiovascular Diseases Phenomenon

    PubMed Central

    Fares, Auda

    2013-01-01

    This paper review seasonal patterns across twelve cardiovascular diseases: Deep venous thrombosis, pulmonary embolism, aortic dissection and rupture, stroke, intracerebral hemorrhage, hypertension, heart failure, angina pectoris, myocardial infarction, sudden cardiac death, venricular arrythmia and atrial fibrillation, and discuss a possible cause of the occurrence of these diseases. There is a clear seasonal trend of cardiovascular diseases, with the highest incidence occurring during the colder winter months, which have been described in many countries. This phenomenon likely contributes to the numbers of deaths occurring in winter. The implications of this finding are important for testing the relative importance of the proposed mechanisms. Understanding the influence of season and other factors is essential when seeking to implement effective public health measures. PMID:23724401

  19. Effects of snow cover properties and path topography on front velocities measured by GEODAR radar

    NASA Astrophysics Data System (ADS)

    Köhler, Anselm; McElwaine, Jim; Sovilla, Betty; Steinkogler, Walter; Fischer, Jan-Thomas

    2015-04-01

    One main challenge in snow avalanche dynamics is to understand the complicated nature of the front dynamics of both cold (dry-dense, powder) and warm (moist, wet) avalanches under changing snow and topographic conditions. Even more complex, by entraining warmer snow at lower altitude, transitional avalanches are able to change the frontal dynamics from cold to warm along the path making the prediction of frontal velocity a challenging task. In order to gain an understanding on avalanche front dynamics, we analyze the front velocities of numerous avalanches measured with the GEODAR radar system installed at the Swiss Vallée de la Sionne full-scale test site. With a spatial resolution of 1 m down slope and a frame rate of 50 Hz, this radar enables the tracking of features at the avalanche front over time, thus allowing a precise definition of the front dynamics. Information on the snow cover is obtained from numerical simulation performed with the model SNOWPACK. Geo-referenced avalanche pictures together with lateral steered GEODAR reflections yield the location and path topography. We compare the front velocities of transitional avalanches with snow cover data and topography along the avalanche path. We show under which conditions changes from cold to warm flow may occur. This analysis is of fundamental importance to understand the effect of snow cover properties on the avalanches dynamics, but also to avoid erroneous interpretations in case the frontal dynamic data are used to calibrate models.

  20. TIM-3 Busy Signals Flow Front Panel

    E-print Network

    University College London

    TIM-3 Busy Signals Flow FPGA2 Front Panel Busy Input (NIM) LK6 PL41 LK4 LK1 PL167 TIMOUTEN Front Panel IDC Busy Input (ECL) Backplane (J3) ROD Busy Inputs LK7 1 Front Panel Busy LED Front Panel Busy (NIM) Front Panel IDC TIM Busy (ECL) Front-panel RODBusy LED Front-panel ROD-Busy Output (NIM

  1. Cold Stress and the Cold Pressor Test

    ERIC Educational Resources Information Center

    Silverthorn, Dee U.; Michael, Joel

    2013-01-01

    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…

  2. Identifying Lagrangian fronts with favourable fishery conditions

    E-print Network

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

    2013-06-20

    Lagrangian fronts (LF) in the ocean delineate boundaries between surface waters with different Lagrangian properties. They can be accurately detected in a given velocity field by computing synoptic maps of the drift of synthetic tracers and other Lagrangian indicators. Using Russian ship's 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 those 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 with the altimetric geostrophic velocity fields both in the years with the First and Second Oyashio Intrusions shows that in spite of different oceanographic conditions the LF locations may serve good indicators of potential fishing grounds. Possible reasons for saury aggregation near LFs are discussed. We propose a mechanism of 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 forecast potential fishing grounds for the other pelagic fishes in different seas and the oceans.

  3. Evolution of a physical and biological front from upwelling to relaxation

    NASA Astrophysics Data System (ADS)

    Zhang, Yanwu; Bellingham, James G.; Ryan, John P.; Godin, Michael A.

    2015-10-01

    Fronts influence the structure and function of coastal marine ecosystems. Due to the complexity and dynamic nature of coastal environments and the small scales of frontal gradient zones, frontal research is difficult. To advance this challenging research we developed a method enabling an autonomous underwater vehicle (AUV) to detect and track fronts, thereby providing high-resolution observations in the moving reference frame of the front itself. This novel method was applied to studying the evolution of a frontal zone in the coastal upwelling environment of Monterey Bay, California, through a period of variability in upwelling intensity. Through 23 frontal crossings in four days, the AUV detected the front using real-time analysis of vertical thermal stratification to identify water types and the front between them, and the vehicle tracked the front as it moved more than 10 km offshore. The physical front coincided with a biological front between strongly stratified phytoplankton-enriched water inshore of the front, and weakly stratified phytoplankton-poor water offshore of the front. While stratification remained a consistent identifier, conditions on both sides of the front changed rapidly as regional circulation responded to relaxation of upwelling winds. The offshore water type transitioned from relatively cold and saline upwelled water to relatively warm and fresh coastal transition zone water. The inshore water type exhibited an order of magnitude increase in chlorophyll concentrations and an associated increase in oxygen and decrease in nitrate. It also warmed and freshened near the front, consistent with the cross-frontal exchange that was detected in the high-resolution AUV data. AUV-observed cross-frontal exchanges beneath the surface manifestation of the front emphasize the importance of AUV synoptic water column surveys in the frontal zone.

  4. Cold knife cone biopsy

    MedlinePLUS

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

  5. Cold and Cough Medicines

    MedlinePLUS

    ... What can you do for your cold or cough symptoms? Besides drinking plenty of fluids and getting ... medicines. There are lots of different cold and cough medicines, and they do different things. Nasal decongestants - ...

  6. Vitamin C and colds

    MedlinePLUS

    ... popular belief that vitamin C can cure the common cold , research about this claim is conflicting. Large doses ... E. Vitamin C for preventing and treating the common cold. Cochrane Database Syst Rev. 2013;1:CD000980. DOI: ...

  7. Coping with Colds

    MedlinePLUS

    ... cold feel better. Back Continue When Should I Go to the Doctor? Teens who catch colds usually ... you start feeling better — the infection may not go away and you can develop other problems. Can ...

  8. INSTABILITY OF MAGNETIZED IONIZATION FRONTS SURROUNDING H II REGIONS

    SciTech Connect

    Kim, Jeong-Gyu; Kim, Woong-Tae E-mail: wkim@astro.snu.ac.kr

    2014-12-20

    An ionization front (IF) surrounding an H II region is a sharp interface where a cold neutral gas makes the transition to a warm ionized phase by absorbing UV photons from central stars. We investigate the instability of a plane-parallel D-type IF threaded by parallel magnetic fields, by neglecting the effects of recombination within the ionized gas. We find that weak D-type IFs always have the post-IF magnetosonic Mach number M{sub 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?{sub 1}) compared to the unmagnetized case, with ?{sub 1} denoting the plasma beta in the pre-IF region. IFs become unstable to distortional perturbations owing 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, and approximately to ?{sup 1/2}. 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{sub M2}{sup 2}<2/(2?{sub 1}?1). When the front experiences an acceleration, the IF instability cooperates with the Rayleigh-Taylor instability to make the front more unstable.

  9. Instability of Magnetized Ionization Fronts Surrounding H II Regions

    NASA Astrophysics Data System (ADS)

    Kim, Jeong-Gyu; Kim, Woong-Tae

    2015-01-01

    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.

  10. Instability of Magnetized Ionization Fronts Surrounding H II Regions

    NASA Astrophysics Data System (ADS)

    Kim, Jeong-Gyu; Kim, Woong-Tae

    2014-12-01

    An ionization front (IF) surrounding an H II region is a sharp interface where a cold neutral gas makes the transition to a warm ionized phase by absorbing UV photons from central stars. We investigate the instability of a plane-parallel D-type IF threaded by parallel magnetic fields, by neglecting the effects of recombination within the ionized gas. 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 owing 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, and approximately to ?1/2. 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}_M22 < 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.

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

    PubMed

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

    2014-07-01

    The microclimate of potential roost-sites is likely to be a crucial determinant in the optimal roost-site selection of endotherms, in particular during the winter season of temperate zones. Available roost-sites for birds and mammals in European high trunk orchards are mainly tree cavities, wood stacks and artificial nest boxes. However, little is known about the microclimatic patterns inside cavities and thermal advantages of using these winter roost-sites. Here, we simultaneously investigate the thermal patterns of winter roost-sites in relation to winter ambient temperature and their insulation capacity. While tree cavities and wood stacks strongly buffered the daily cycle of temperature changes, nest boxes showed low buffering capacity. The buffering effect of tree cavities was stronger at extreme ambient temperatures compared to temperatures around zero. Heat sources inside roosts amplified ? T (i.e., the difference between inside and outside temperatures), particularly in the closed roosts of nest boxes and tree cavities, and less in the open wood stacks with stronger circulation of air. Positive ? T due to the installation of a heat source increased in cold ambient temperatures. These results suggest that orchard habitats in winter show a spatiotemporal mosaic of sites providing different thermal benefits varying over time and in relation to ambient temperatures. At cold temperatures tree cavities provide significantly higher thermal benefits than nest boxes or wood stacks. Thus, in winter ecology of hole-using endotherms, the availability of tree cavities may be an important characteristic of winter habitat quality. PMID:23423627

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

    NASA Astrophysics Data System (ADS)

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

    2014-07-01

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

  13. Colds and flus - antibiotics

    MedlinePLUS

    Antibiotics - colds and flu ... treat infections that are caused by a virus. Colds and flu are caused by viruses. If you ... Hamilton A. Treatments for symptoms of the common cold. Am Fam Physician. 2013;88(3):864C-864D.

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

    PubMed Central

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

    2012-01-01

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

  15. Active learning of Pareto fronts.

    PubMed

    Campigotto, Paolo; Passerini, Andrea; Battiti, Roberto

    2014-03-01

    This paper introduces the active learning of Pareto fronts (ALP) algorithm, a novel approach to recover the Pareto front of a multiobjective optimization problem. ALP casts the identification of the Pareto front into a supervised machine learning task. This approach enables an analytical model of the Pareto front to be built. The computational effort in generating the supervised information is reduced by an active learning strategy. In particular, the model is learned from a set of informative training objective vectors. The training objective vectors are approximated Pareto-optimal vectors obtained by solving different scalarized problem instances. The experimental results show that ALP achieves an accurate Pareto front approximation with a lower computational effort than state-of-the-art estimation of distribution algorithms and widely known genetic techniques. PMID:24807447

  16. Cough and Cold Medicine Abuse

    MedlinePLUS

    ... and Cold Medicine Abuse DrugFacts: Cough and Cold Medicine Abuse Email Facebook Twitter Revised May 2014 Some ... diverted for abuse. How Are Cough and Cold Medicines Abused? Cough and cold medicines are usually consumed ...

  17. Winter Frost and Fog

    NASA Technical Reports Server (NTRS)

    2005-01-01

    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

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

    NASA Astrophysics Data System (ADS)

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

    2011-11-01

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

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

    USGS Publications Warehouse

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

    2009-01-01

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

  20. Enzymatic activity of rodents acclimated to cold and long scotophase

    NASA Astrophysics Data System (ADS)

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

    1980-09-01

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

  1. Haemonchus contortus microtubules are cold resistant.

    PubMed

    Ashraf, Shoaib; Prichard, Roger K

    2014-01-01

    Haemonchus contortus is an important nematode of livestock that is present in most parts of the world. The life cycle comprises free living stages (egg, L1, L2 and L3 larvae), and parasitic stages (L4, adult and egg) in a ruminant. Microtubules are filamentous structures which are made from polymerization of ?- and ?-tubulin. In vitro polymerization of ?- and ?-tubulin can be achieved by increasing the temperature to 37°C under certain conditions. As part of its normal functioning, in mammals, the microtubules can be depolymerized when the temperature is reduced to 0°C. However, interestingly the microtubules of H. contortus are cold resistant i.e. they do not depolymerize at 0°C. Moreover these microtubules did not depolymerize even in the presence of 5 mM CaCl2 or 50 ?M colchicine. These interesting findings may explain how larvae in the free living stages may survive cold temperatures over winter. PMID:24525483

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

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

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

    ERIC Educational Resources Information Center

    Department of Energy, Washington, DC.

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

  4. 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

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

    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…

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

    NASA Astrophysics Data System (ADS)

    Hori, M. E.; Inoue, J.

    2011-12-01

    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.

  6. How cold is cold dark matter?

    SciTech Connect

    Armendariz-Picon, Cristian; Neelakanta, Jayanth T. E-mail: jtneelak@syr.edu

    2014-03-01

    If cold dark matter consists of particles, these must be non-interacting and non-relativistic by definition. In most cold dark matter models however, dark matter particles inherit a non-vanishing velocity dispersion from interactions in the early universe, a velocity that redshifts with cosmic expansion but certainly remains non-zero. In this article, we place model-independent constraints on the dark matter temperature to mass ratio, whose square root determines the dark matter velocity dispersion. We only assume that dark matter particles decoupled kinetically while non-relativistic, when galactic scales had not entered the horizon yet, and that their momentum distribution has been Maxwellian since that time. Under these assumptions, using cosmic microwave background and matter power spectrum observations, we place upper limits on the temperature to mass ratio of cold dark matter today (away from collapsed structures). These limits imply that the present cold dark matter velocity dispersion has to be smaller than 54 m/s. Cold dark matter has to be quite cold, indeed.

  7. Asymmetric counterpropagating fronts without flow.

    PubMed

    Andrade-Silva, I; Clerc, M G; Odent, V

    2015-06-01

    Out-of-equilibrium systems exhibit domain walls between different states. These walls, depending on the type of connected states, can display rich spatiotemporal dynamics. In this Rapid Communication, we investigate the asymmetrical counterpropagation of fronts in an in-plane-switching cell filled with a nematic liquid crystal. Experimentally, we characterize the different front shapes and propagation speeds. These fronts present dissimilar elastic deformations that are responsible for their asymmetric speeds. Theoretically, using a phenomenological model, we describe the observed dynamics with fair agreement. PMID:26172647

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

    NASA Astrophysics Data System (ADS)

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

    2013-11-01

    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.

  9. 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...

  10. 18 Planet Earth Winter 2010 he key feature that links many severe

    E-print Network

    Woollings, Tim

    of the most common variations in the North Atlantic jet stream is for the whole jet to shift to the north Winds of change? Severe weather has been big news in recent years. The cold European winter of 2009-10 was followed by a deadly heatwave in Russia and devastating floods in Pakistan. Unsurprisingly, people want

  11. OVER WINTER STABILITY AND HYDROLOGY OF MACROPORES IN THE NORTHERN US CORN BELT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Macropores created by biological or physical processes can profoundly influence water movement through the soil. In cold regions, macropore stability can be influenced by natural processes such as wetting/drying and freezing/thawing. Little is known, however, concerning the over winter stability of ...

  12. 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...

  13. Red spruce decline---Winter injury and air pollutants

    SciTech Connect

    Roberts, T.M. )

    1989-10-01

    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.

  14. Sex-specific winter distribution in a sexually dimorphic shorebird is explained by resource partitioning

    PubMed Central

    Duijns, Sjoerd; van Gils, Jan A; Spaans, Bernard; ten Horn, Job; Brugge, Maarten; Piersma, Theunis

    2014-01-01

    Sexual size dimorphism (SSD) implies correlated differences in energetic requirements and feeding opportunities, such that sexes will face different trade-offs in habitat selection. In seasonal migrants, this could result in a differential spatial distribution across the wintering range. To identify the ecological causes of sexual spatial segregation, we studied a sexually dimorphic shorebird, the bar-tailed godwit Limosa lapponica, in which females have a larger body and a longer bill than males. With respect to the trade-offs that these migratory shorebirds experience in their choice of wintering area, northern and colder wintering sites have the benefit of being closer to the Arctic breeding grounds. According to Bergmann's rule, the larger females should incur lower energetic costs per unit of body mass over males, helping them to winter in the cold. However, as the sexes have rather different bill lengths, differences in sex-specific wintering sites could also be due to the vertical distribution of their buried prey, that is, resource partitioning. Here, in a comparison between six main intertidal wintering areas across the entire winter range of the lapponica subspecies in northwest Europe, we show that the percentage of females between sites was not correlated with the cost of wintering, but was positively correlated with the biomass in the bottom layer and negatively with the biomass in the top layer. We conclude that resource partitioning, rather than relative expenditure advantages, best explains the differential spatial distribution of male and female bar-tailed godwits across northwest Europe. PMID:25505527

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

    PubMed

    Glanville, Elsa J; Seebacher, Frank

    2010-03-01

    Small mammals that remain active throughout the year at a constant body temperature have a much greater energy and food requirement in winter. Lower body temperatures in winter may offset the increased energetic cost of remaining active in the cold, if cellular metabolism is not constrained by a negative thermodynamic effect. We aimed to determine whether variable body temperatures can be advantageous for small endotherms by testing the hypothesis that body temperature fluctuates seasonally in a wild rat (Rattus fuscipes); conferring an energy saving and reducing food requirements during resource restricted winter. Additionally we tested whether changes in body temperature affected tissue specific metabolic capacity. Winter acclimatized rats had significantly lower body temperatures and thicker fur than summer acclimatized rats. Mitochondrial oxygen consumption and the activity of enzymes that control oxidative (citrate synthase, cytochrome c-oxidase) and anaerobic (lactate dehydrogenase) metabolism were elevated in winter and were not negatively affected by the lower body temperature. Energy transfer modeling showed that lower body temperatures in winter combined with increased fur thickness to confer a 25 kJ day(-1) energy saving, with up to 50% owing to reduced body temperature alone. We show that phenotypic plasticity at multiple levels of organization is an important component of the response of a small endotherm to winter. Mitochondrial function compensates for lower winter body temperatures, buffering metabolic heat production capacity. PMID:20026416

  16. Winter fuels report

    SciTech Connect

    Not Available

    1995-02-03

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

  17. Winter fuels report

    SciTech Connect

    Not Available

    1995-02-17

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

  18. Winter fuels report

    SciTech Connect

    Not Available

    1990-11-29

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

  19. Multiple thermal fronts near the Patagonian shelf break

    NASA Astrophysics Data System (ADS)

    Franco, Bárbara C.; Piola, Alberto R.; Rivas, Andrés L.; Baldoni, Ana; Pisoni, Juan P.

    2008-01-01

    Eighteen year (1985-2002) sea surface temperature (SST) data are used to study the intraseasonal variability of the Patagonian shelf break front (SBF) in the SW South Atlantic Ocean between 39° and 44°S. The cross-shelf break SST gradients reveal distinct, previously undocumented thermal fronts located both, offshore and inshore of the SBF. Throughout the year the main SBF, identified as a band of negative SST gradient maxima (relatively strong offshore temperature decrease), forms a persistent feature located closed to the 200 m isobath, while two distinct negative gradient maxima are located inshore and offshore of this location. Daily SST images reveal the presence of three branches of cold waters whose edges delineate the above mentioned fronts. The two offshore branches closely follow lines of constant potential vorticity (f/h) and appear to be associated with the Malvinas Current, while a third branch, located further onshore, is not steered by the bottom topography. South of 40°S the onshore branch forms a quasi permanent front parallel to the SBF.

  20. Deuterium content of snow as an index to winter climate in the Sierra Nevada area

    USGS Publications Warehouse

    Friedman, I.; Smith, G.I.

    1972-01-01

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

  1. Shifts of the Subtropical Shelf Front controlled by atmospheric variations

    NASA Astrophysics Data System (ADS)

    Balcerak, Ernie

    2013-10-01

    In the western South Atlantic, off the coast of South America, a band of cold, fresh, nutrient-rich Sub-Antarctic Shelf Water (SASW) meets warm, salty, nutrient-poor Subtropical Shelf Water (STSW) to form the Subtropical Shelf Front (STSF). This front is the shallow-water expression of the major Brazil-Malvinas Confluence Zone and has moved northward and southward during the Holocene (the past ~12,000 years). Bender et al. reconstruct the latitudinal shifts of the STSF over the past 11,000 calendar-equivalent years using records of oxygen and carbon stable isotope compositions of benthic foraminifera and total organic carbon and calcium carbonate content from a sediment record collected off Uruguay. These measurements serve as proxies for ocean water temperature and nutrient content, which can be used to distinguish the SASW and STSW.

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

    PubMed Central

    Rozsypal, Jan; Koštál, Vladimír; Zahradní?ková, Helena; Šimek, Petr

    2013-01-01

    Background The codling moth (Cydia pomonella) is a major insect pest of apples worldwide. Fully grown last instar larvae overwinter in diapause state. Their overwintering strategies and physiological principles of cold tolerance have been insufficiently studied. No elaborate analysis of overwintering physiology is available for European populations. Principal Findings We observed that codling moth larvae of a Central European population prefer to overwinter in the microhabitat of litter layer near the base of trees. Reliance on extensive supercooling, or freeze-avoidance, appears as their major strategy for survival of the winter cold. The supercooling point decreases from approximately ?15.3°C during summer to ?26.3°C during winter. Seasonal extension of supercooling capacity is assisted by partial dehydration, increasing osmolality of body fluids, and the accumulation of a complex mixture of winter specific metabolites. Glycogen and glutamine reserves are depleted, while fructose, alanine and some other sugars, polyols and free amino acids are accumulated during winter. The concentrations of trehalose and proline remain high and relatively constant throughout the season, and may contribute to the stabilization of proteins and membranes at subzero temperatures. In addition to supercooling, overwintering larvae acquire considerable capacity to survive at subzero temperatures, down to ?15°C, even in partially frozen state. Conclusion Our detailed laboratory analysis of cold tolerance, and whole-winter survival assays in semi-natural conditions, suggest that the average winter cold does not represent a major threat for codling moth populations. More than 83% of larvae survived over winter in the field and pupated in spring irrespective of the overwintering microhabitat (cold-exposed tree trunk or temperature-buffered litter layer). PMID:23613923

  3. Winter storm-induced hydrodynamics and morphological response of a shallow transgressive shoal complex: Northern Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Siadatmousavi, S. Mostafa; Jose, Felix

    2015-03-01

    Using extended deployments during seasons of low and high discharge from the Atchafalaya River, meteorological, hydrodynamic and bottom boundary layer parameters were monitored from Tiger and Trinity Shoal complex, off Louisiana coast, USA. During winter storms, the surface current speed measured at both shoals exceeded 0.5 m/s and the entire water column followed the prevailing wind direction. The current speed close to the bottom exceeded 0.3 m/s during high energy northerly winds. The mean water level in the shoal complex increased during southerly winds and decreased during northerly winds, such that the difference between wind set-up and set-down exceeded 0.7 m in Tiger Shoal and 0.6 m in Trinity Shoal during high energy frontal passages. The swell height was inversely correlated with mean water level, and increased during pre-frontal phase and decreased during post-frontal phase of winter storms. The sea (short waves) height responded quickly to wind direction and speed; and within a few hours after the wind shifted and blowing from the north, the sea height increased during both deployments. Bimodal wave frequency spectrum was observed during wind veering from southerly to northerly, when both sea and swell intensities were significant. The Tiger Shoal bed sediment texture transformed drastically, from mud to shell and shell hash assemblage, within a period of two weeks during the December 2008 deployment. Backscatter signal intensity from a Pulse Coherent Acoustic Doppler Profiler (PCADP) and its velocity estimates were used to determine the vertical extend and timing of mud resuspension and their eventual flushing out from the shoal environment, when exposed to high energy winter storm passages. The computed time frame for a total transformation of bottom sediment texture (from muddy bottom to shell and shell hash assemblage) was supported by the combined wave and bottom current induced shear stress at shoal bed. The bed samples collected from Tiger Shoal before and after the deployment in spring 2009 consisted of more than 80% shell and shell hash, which again confirmed a stable bottom as predicted from the PCADP data. However, the fine sand and mud dominated bed at Trinity Shoal was highly dynamic and experienced a few cm of ephemeral sediment deposition during the passage of each cold front, as revealed from the analysis of acoustic backscatter data from the PCADP. Suspended sediment concentration estimated from Optical Backscatterance Sensors (OBS) and PCADP were in good agreement during low river discharge events in December 2008; but significantly diverged during the spring 2009 deployment, when a high suspended sediment load was discharged into the shelf from the Atchafalaya River, and subsequently pushed farther offshore into the deployment sites by wind-induced strong currents during the passage of cold fronts.

  4. Cold fusion, Alchemist's dream

    SciTech Connect

    Clayton, E.D.

    1989-09-01

    In this report the following topics relating to cold fusion are discussed: muon catalysed cold fusion; piezonuclear fusion; sundry explanations pertaining to cold fusion; cosmic ray muon catalysed cold fusion; vibrational mechanisms in excited states of D{sub 2} molecules; barrier penetration probabilities within the hydrogenated metal lattice/piezonuclear fusion; branching ratios of D{sub 2} fusion at low energies; fusion of deuterons into {sup 4}He; secondary D+T fusion within the hydrogenated metal lattice; {sup 3}He to {sup 4}He ratio within the metal lattice; shock induced fusion; and anomalously high isotopic ratios of {sup 3}He/{sup 4}He.

  5. [Cold-induced urticaria].

    PubMed

    Delorme, N; Drouet, M; Thibaudeau, A; Verret, J L

    2002-09-01

    Cold urticaria is characterized by the development of urticaria, usually superficial and/or angioedematous reaction after cold contact. It was found predominantly in young women. The diagnosis is based on the history and ice cube test. Patients with a negative ice cube test may have represented systemic cold urticaria (atypical acquired cold urticaria) induced by general body cooling. The pathogenesis is poorly understood. Cold urticaria can be classified into acquired and familial disorders, with an autosomal dominant inheritance. Idiopathic cold urticaria is most common type but the research of a cryopathy is necessary. Therapy is often difficult. It is essential that the patient be warned of the dangers of swimming in cold water because systemic hypotension can occur. H1 antihistamines can be used for treatment of cold urticaria but the clinical responses are highly variable. The combination with an H2 antagonists is more effective. Doxepin may be useful in the treatment. Leukotriene receptor antagonists may be a novel, promising drug entity. In patients who do not respond to previous treatments, induction of cold tolerance may be tried. PMID:12389450

  6. Cold fusion: Alchemist's dream

    NASA Astrophysics Data System (ADS)

    Clayton, E. D.

    1989-09-01

    In this report the following topics relating to cold fusion are discussed: muon catalyzed cold fusion; piezonuclear fusion; sundry explanations pertaining to cold fusion; cosmic ray muon catalyzed cold fusion; vibrational mechanisms in excited states of D2 molecules; barrier penetration probabilities within the hydrogenated metal lattice/piezonuclear fusion; branching ratios of D2 fusion at low energies; fusion of deuterons into He-4; secondary D+T fusion within the hydrogenated metal lattice; helium-3 to helium-4 ratio within the metal lattice; shock induced fusion; and anomalously high isotopic ratios of helium-3/helium-4.

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

    PubMed Central

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

    2011-01-01

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

  8. Cold Weather Entomology.

    ERIC Educational Resources Information Center

    McLure, John W.

    1983-01-01

    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)

  9. Fossils tell of mild winters in an ancient hothouse

    SciTech Connect

    Kerr, R.A.

    1993-08-06

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

  10. How cold pool triggers deep convection?

    NASA Astrophysics Data System (ADS)

    Yano, Jun-Ichi

    2014-05-01

    The cold pool in the boundary layer is often considered a major triggering mechanism of convection. Here, presented are basic theoretical considerations on this issue. Observations suggest that cold pool-generated convective cells is available for shallow maritime convection (Warner et al. 1979; Zuidema et al. 2012), maritime deep convection (Barnes and Garstang 1982; Addis et al. 1984; Young et al. 1995) and continental deep convection (e.g., Lima and Wilson 2008; Flamant 2009; Lothon et al. 2011; Dione et al. 2013). Moreover, numerical studies appear to suggest that cold pools promote the organization of clouds into larger structures and thereby aid the transition from shallow to deep convection (Khairoutdinov and Randall 2006, Boing et al. 2012, Schlemmer and Hohenegger, 2014). Even a cold--pool parameterization coupled with convection is already proposed (Grandpeix and Lafore 2010: but see also Yano 2012). However, the suggested link between the cold pool and deep convection so far is phenomenological at the best. A specific process that the cold pool leads to a trigger of deep convection must still to be pinned down. Naively, one may imagine that a cold pool lifts up the air at the front as it propagates. Such an uplifting leads to a trigger of convection. However, one must realize that a shift of air along with its propagation does not necessarily lead to an uplifting, and even if it may happen, it would not far exceed a depth of the cold pool itself. Thus, the uplifting can never be anything vigorous. Its thermodynamic characteristics do help much either for inducing convection. The cold-pool air is rather under rapid recovering process before it can induce convection under a simple parcel-lifting argument. The most likely reason that the cold pool may induce convection is its gust winds that may encounter an air mass from an opposite direction. This induces a strong convergence, also leading to a strong uplifting. This is an argument essentially developed by Moncrieff and Liu (1999). As a whole, in attempting a statistical description of boundary-layer processes, the cold pool is essentially nothing other than an additional contribution to a TKE (turbulent kinetic energy) budget. Significance of trigger of convection by cold pool in context of convection parameterization must also be seen with much caution. Against a common misunderstanding, current convection parameterization is not designed to describe a trigger process of individual convection. In this respect, process studies on cold pool do not contribute to improvements of convection parameterization until a well-defined parameterization formulation for individual convection processes is developed. Even before then a question should also be posed whether such a development is necessary. Under a current mass-flux convection parameterization, a more important process to consider is re-evaporative cooling of detrained cloudy air, which may also be associated with downdraft, possibly further leading to a generation of a cold pool. Yano and Plant (2012) suggest, from a point of view of the convective-energy cycle, what follows would be far less important than the fact the re-evaporation induces a generation of convective kinetic energy (though it may initially be considered TKE). Both well-focused convective process studies as well as convection parameterization formulation would be much needed.

  11. Episodic Dust Events along Utah's Wasatch Front

    NASA Astrophysics Data System (ADS)

    Massey, J.; Steenburgh, W. J.; Painter, T. H.

    2011-12-01

    Episodic dust events contribute to hazardous air quality along Utah's Wasatch Front urban corridor and, through deposition onto the snowpack of the adjacent Wasatch Mountains, regional hydroclimate change. This study creates a climatology of these episodic dust events using surface-weather observations, GOES visible satellite imagery, and the North American Regional Analysis. In hourly weather observations from the Salt Lake International Airport (KSLC), a dust storm, blowing dust, and/or dust in suspension (i.e., dust haze) with a visibility 10 km (6 mi) or less occurs an average of ~4 days per water year (Oct-Sep), with considerable interannual variability during the 1930-2010 period of record. The monthly frequency of days with at least one dust report is strongly bimodal with primary and secondary maxima in Apr and Sep, respectively. Dust reports exhibit a strong diurnal modulation and are most common in the late afternoon and evening. Most recent (2001-2010) events observed at KSLC are produced by intermountain cyclones and/or cold-frontal troughs (i.e., cyclone/frontal), followed by outflow from airmass/monsoon convection. In the case of the former, dust is most frequently observed right around the time of cold frontal passage. GOES satellite imagery and backtrajectories of events at KSLC and in the surrounding region indicate that the primary dust emission sources are clustered in the deserts and dry lake beds of southern Utah as well as the burn area of the 2007 Milford Flat Fire and the Carson Sink of Nevada.

  12. Record low total ozone during northern winters of 1992 and 1993

    SciTech Connect

    Bojkov, R.D. )

    1993-07-09

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

  13. Cold Sores (HSV-1)

    MedlinePLUS

    ... Guy's Guide to Body Image Cold Sores (HSV-1) KidsHealth > Teens > Body > Skin Stuff > Cold Sores (HSV-1) Print A A A Text Size What's in ... person's lips, are caused by herpes simplex virus-1 (HSV-1) . But they don't just show ...

  14. Crystallization and saturation front propagation in silicic magma chambers

    NASA Astrophysics Data System (ADS)

    Lake, Ethan T.

    2013-12-01

    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.

  15. Winter fuels report

    SciTech Connect

    Not Available

    1995-01-27

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

  16. Winter fuels report

    SciTech Connect

    Not Available

    1995-01-13

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

  17. Winter fuels report

    SciTech Connect

    Not Available

    1990-10-04

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

  18. Winter fuels report

    SciTech Connect

    Not Available

    1994-10-01

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

  19. PHYSICS 122 LABORATORY (Winter, 2015)

    E-print Network

    Yoo, S. J. Ben

    - 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 752-4689 TEACHING ASSISTANTS: Andrew Bradshaw 518

  20. Winter Weather Frequently Asked Questions

    MedlinePLUS

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

  1. Passive thermal refugia provided warm water for Florida manatees during the severe winter of 2009-2010

    USGS Publications Warehouse

    Stith, B.M.; Slone, D.H.; de Wit, M.; Edwards, H.H.; Langtimm, C.A.; Swain, E.D.; Soderqvist, L.E.; Reid, J.P.

    2012-01-01

    Haloclines induced by freshwater inflow over tidal water have been identified as an important mechanism for maintaining warm water in passive thermal refugia (PTR) used by Florida manatees Trichechus manatus latirostris during winter in extreme southwestern Florida. Record-setting cold during winter 2009–2010 resulted in an unprecedented number of manatee deaths, adding to concerns that PTR may provide inadequate thermal protection during severe cold periods. Hydrological data from 2009–2010 indicate that 2 canal systems in the Ten Thousand Islands (TTI) region acted as PTR and maintained warm bottom-water temperatures, even during severe and prolonged cold periods. Aerial survey counts of live and dead manatees in TTI during the winter of 2009–2010 suggest that these PTR were effective at preventing mass mortality from hypothermia, in contrast to the nearby Everglades region, which lacks similar artificial PTR and showed high manatee carcass counts. Hydrological data from winter 2008–2009 confirmed earlier findings that without haloclines these artificial PTR may become ineffective as warm-water sites. Tidal pumping of groundwater appears to provide additional heat to bottom water during low tide cycles, but the associated thermal inversion is not observed unless salinity stratification is present. The finding that halocline-driven PTR can maintain warm water even under extreme winter conditions suggests that they may have significant potential as warm-water sites. However, availability and conflicting uses of freshwater and other management issues may make halocline-driven PTR unreliable or difficult to manage during winter.

  2. Ice conditions on the Chesapeake Bay as observed from LANDSAT during the winters of 1977, 1978 and 1979

    NASA Technical Reports Server (NTRS)

    Foster, J. L.

    1980-01-01

    The LANDSAT observations during the winters of 1977, 1978 and 1979, which were unusually cold in the northeastern U.S. and in the Chesapeake Bay area, were evaluated. Abnormal atmospheric circulation patterns displaced cold polar air to the south, and as a result, the Chesapeake Bay experienced much greater than normal icing conditions during these 3 years. The LANDSAT observations of the Chesapeake Bay area during these winters demonstrate the satellite's capabilities to monitor ice growth and melt, to detect ice motions, and to measure ice extent.

  3. WINTER WHEAT VARIETIES Performance Evaluation and Recommendations

    E-print Network

    Dyer, Bill

    2015 WINTER WHEAT VARIETIES Performance Evaluation and Recommendations AND DISTRICTS Wheat Bearpaw +1/ D D D Broadview (P)++ D D Carter (P)+ D D D D D CDC Falcon (P)+ DI DI DI DI DI Colter Winter Wheat for Montana by District #12;TABLE OF CONTENTS Page Hard Red Winter and Soft White Winter

  4. Influence of the winter North Atlantic Oscillation (NAO) on ENSO in the following winter by Multi-model evaluation

    NASA Astrophysics Data System (ADS)

    Nakamura, Tetsu; Tachibana, Yoshihiro; Hara, Masayuki; Oshika, Miki

    2015-04-01

    This study tested the hypothesis that occurrence of a warm (clod) phase of El Niño/Southern Oscillation (ENSO) in a given winter can be predicted 1 year in advance by the North Atlantic Oscillation (NAO). A one-year-lagged relationship between the NAO in winter and ENSO in the following year was examined with a multi-model ensemble analysis using Coupled Model Intercomparison Project phase 3 models and reanalysis data. On the basis of a 51-year statistical analysis of reanalysis data, we propose that El Niño outbreak in the winter is linked to the negative phase of the NAO in the previous winter. A coherency index was developed as a measure of the coherence between the NAO and ENSO in each model and used as a weighting factor in the ensemble model. Weighted multi-model ensemble means of the regressed field on the maximum covariance analysis coefficients between the surface pressure field in the North Atlantic (NAO field) and the sea surface temperature field in the equatorial Pacific (ENSO field) were explored. The results indicated that when the wintertime NAO was in its negative (positive) phase, anomalous atmospheric circulation associated with a large (small) Eurasian snow mass anomaly intensified (weakened) the Asian cold surge and the westerly wind burst (WWB) in the warm pool region. Intensification of the WWB initiates El Niño. A sensitivity experiment using an idealized dry general circulation model revealed that the atmospheric response to anomalous, near-surface cooling associated with an anomalous Eurasian snow mass induced higher surface pressure near the Tibetan plateau and thus intensified the Asian cold surge and WWB. Linear regression analyses applied to the reanalysis data strongly supported the model results. Our results therefore suggest an influence of the NAO on the initiation of El Niño via a process that involves Eurasian snow anomalies associated with the NAO phase.

  5. An optimal index for measuring the effect of East Asian winter monsoon on China winter temperature

    NASA Astrophysics Data System (ADS)

    Hu, Chundi; Yang, Song; Wu, Qigang

    2015-11-01

    Extreme cold events occur frequently in China. The authors define a representative yet simple index to reveal the monthly changes in China winter temperature associated with the East Asian winter monsoon (EAWM), which is represented by both the leading empirical orthogonal function (EOF) mode and the country-mean temperature index of Chinese 160 gauge stations. A combined technique of correlation and multivariate EOF (Corr-MVEOF) analyses is applied to capture the dominant coupled patterns of EAWM circulation system. Based on the atmospheric circulation features captured by the leading Corr-MVEOF mode, a new EAWM index referred to as CNWMI is derived by using a stepwise regression analysis. The CNWMI highlights the importance of (1) the Mongolia-Siberian High (MSH) and its southward expansion and (2) the Asia-wide meridional dipole anomaly of 500 hPa geopotential height. Compared with the 27 existing EAWM indices, the CNWMI not only best represents the leading modes of both EAWM circulation system and China winter temperature, but also reasonably tracks the intraseasonal-to-interdecadal variations of EAWM so that the monthly intensity of EAWM can be monitored conveniently. In particular, the Aleutian low (AL) is not strongly related to the MSH and may not be responsible for the variability of EAWM/MSH. Moreover, the indices that are highly correlated with the temperature over southern East Asia do not show significant relationships with the AL, which is different from the conventional concept that a strong EAWM/MSH is linked to a deepened AL. In contrast, the anomalous Australia-Maritime Continent low is in good agreement with the variation of EAWM/MSH.

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

    PubMed Central

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

    2010-01-01

    Abstract A largely unanswered question in the study of arboviruses is the extent to which virus can overwinter in adult vectors during the cold winter months and resume the transmission cycle in summer. Buggy Creek virus (BCRV; Togaviridae, Alphavirus) is an unusual arbovirus that is vectored primarily by the swallow bug (Hemiptera: Cimicidae: Oeciacus vicarius) and amplified by the ectoparasitic bug's main avian hosts, the migratory cliff swallow (Petrochelidon pyrrhonota) and resident house sparrow (Passer domesticus). Bugs are sedentary and overwinter in the swallows' mud nests. We evaluated the prevalence of BCRV and extent of infection in swallow bugs collected at different times in winter (October–early April) in Nebraska and explored other ecological aspects of this virus's overwintering. BCRV was detected in 17% of bug pools sampled in winter. Virus prevalence in bugs in winter at a site was significantly correlated with virus prevalence at that site the previous summer, but winter prevalence did not predict BCRV prevalence there the following summer. Prevalence was higher in bugs taken from house sparrow nests in winter and (in April) at colony sites where sparrows had been present all winter. Virus detected by reverse transcription (RT)-polymerase chain reaction in winter was less cytopathic than in summer, but viral RNA concentrations of samples in winter were not significantly different from those in summer. Both of the BCRV lineages (A, B) overwintered successfully, with lineage A more common at sites with house sparrows and (in contrast to summer) generally more prevalent in winter than lineage B. BCRV's ability to overwinter in its adult vector probably reflects its adaptation to the sedentary, long-lived bug and the ecology of the cliff swallow and swallow bug host–parasite system. Its overwintering mechanisms may provide insight into those of other alphaviruses of public health significance for which such mechanisms are poorly known. PMID:19725760

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

    NASA Astrophysics Data System (ADS)

    Mazon, Jordi; Pino, David

    2015-02-01

    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.

  8. Improving the health forecasting alert system for cold weather and heat-waves in England: a case-study approach using temperature-mortality relationships

    NASA Astrophysics Data System (ADS)

    Masato, Giacomo; Cavany, Sean; Charlton-Perez, Andrew; Dacre, Helen; Bone, Angie; Carmicheal, Katie; Murray, Virginia; Danker, Rutger; Neal, Rob; Sarran, Christophe

    2015-04-01

    The health forecasting alert system for cold weather and heatwaves currently in use in the Cold Weather and Heatwave plans for England is based on 5 alert levels, with levels 2 and 3 dependent on a forecast or actual single temperature action trigger. Epidemiological evidence indicates that for both heat and cold, the impact on human health is gradual, with worsening impact for more extreme temperatures. The 60% risk of heat and cold forecasts used by the alerts is a rather crude probabilistic measure, which could be substantially improved thanks to the state-of-the-art forecast techniques. In this study a prototype of a new health forecasting alert system is developed, which is aligned to the approach used in the Met Office's (MO) National Severe Weather Warning Service (NSWWS). This is in order to improve information available to responders in the health and social care system by linking temperatures more directly to risks of mortality, and developing a system more coherent with other weather alerts. The prototype is compared to the current system in the Cold Weather and Heatwave plans via a case-study approach to verify its potential advantages and shortcomings. The prototype health forecasting alert system introduces an "impact vs likelihood matrix" for the health impacts of hot and cold temperatures which is similar to those used operationally for other weather hazards as part of the NSWWS. The impact axis of this matrix is based on existing epidemiological evidence, which shows an increasing relative risk of death at extremes of outdoor temperature beyond a threshold which can be identified epidemiologically. The likelihood axis is based on a probability measure associated with the temperature forecast. The new method is tested for two case studies (one during summer 2013, one during winter 2013), and compared to the performance of the current alert system. The prototype shows some clear improvements over the current alert system. It allows for a much greater degree of flexibility, provides more detailed regional information about the health risks associated with periods of extreme temperatures, and is more coherent with other weather alerts which may make it easier for front line responders to use. It will require validation and engagement with stakeholders before it can be considered for use.

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

    E-print Network

    Gunawardena, Arunika

    and Winter Caitlin Lynch-StauntonWinter Only Jenna Nolan Fall and Winter Kelsey MacNeil Winter Only Lyle Armstrong Winter Only Nicolas Banks Fall and Winter Megan Armsworthy Winter Only Justin Barbati Fall

  10. 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

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

    SciTech Connect

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

    2011-11-11

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

  12. Cold subcutaneous abscesses.

    PubMed Central

    Jackson, R.; Stephens, L.; Kelly, A. P.

    1990-01-01

    Cold abscesses are defined as having no associated erythema, heat, or tenderness. They may be present in immunodeficiency disorders, deep mycoses, and other infectious diseases. As there is a dearth information on this subject in the dermatology, surgery, and infectious disease literature, we present a case of cold abscesses secondary to coccidioidomycosis and discuss the possible role of humoral immunity, cell-mediated immunity, prostaglandins, T cells, and other mediators in cold abscess pathogenesis. In addition, therapeutic guidelines for abscesses are reviewed. Images Figure 1 Figure 2 PMID:2280425

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

    NASA Astrophysics Data System (ADS)

    Tachibana, Yoshihiro; Oshika, Miki; Nakamura, Tetsu

    2015-04-01

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

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

    USGS Publications Warehouse

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

    2006-01-01

    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.

  15. The impact of the 2008 cold spell on mortality in Shanghai, China

    NASA Astrophysics Data System (ADS)

    Ma, Wenjuan; Yang, Chunxue; Chu, Chen; Li, Tiantian; Tan, Jianguo; Kan, Haidong

    2013-01-01

    No prior studies in China have investigated the health impact of cold spell. In Shanghai, we defined the cold spell as a period of at least seven consecutive days with daily temperature below the third percentile during the study period (2001-2009). Between January 2001 and December 2009, we identified a cold spell between January 27 and February 3, 2008 in Shanghai. We investigated the impact of cold spell on mortality of the residents living in the nine urban districts of Shanghai. We calculated the excess deaths and rate ratios (RRs) during the cold spell and compared these data with a winter reference period (January 6-9, and February 28 to March 2). The number of excess deaths during the cold spell period was 153 in our study population. The cold spell caused a short-term increase in total mortality of 13 % (95 % CI: 7-19 %). The impact was statistically significant for cardiovascular mortality (RR = 1.21, 95 % CI: 1.12-1.31), but not for respiratory mortality (RR = 1.14, 95 % CI: 0.98-1.32). For total mortality, gender did not make a statistically significant difference for the cold spell impact. Cold spell had a significant impact on mortality in elderly people (over 65 years), but not in other age groups. Conclusively, our analysis showed that the 2008 cold spell had a substantial effect on mortality in Shanghai. Public health programs should be tailored to prevent cold-spell-related health problems in the city.

  16. The History of Winter: teachers as scientists

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

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

    USGS Publications Warehouse

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

    2015-01-01

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

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

    USGS Publications Warehouse

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

    2011-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2011-07-01

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

  20. Could behaviour and not physiological thermal tolerance determine winter survival of aphids in cereal fields?

    PubMed

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

    2014-01-01

    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

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

    USGS Publications Warehouse

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

    1988-01-01

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

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

    USGS Publications Warehouse

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

    1984-01-01

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

  3. Cold Rover for Mars

    NASA Astrophysics Data System (ADS)

    Mojarradi, M.; Some, R.; Sirota, A.; Boykins, C.; Cressler, J.; Blalock, B.

    2012-06-01

    We propose to build a highly Cold Rover that uses combination of electronic components, thermal cycle resistance electronics packaging and low temperature capable mechanical components that have the ability to directly operate at the Martian surface.

  4. Colds and the Flu

    MedlinePLUS

    ... with green- or yellow-colored discharge) Sore throat Cough Sneezing Fatigue Muscle aches Headache Watery eyes Cold ... aches, especially in your back, arms and legs Cough Headache Loss of appetite What is H1N1 flu? ...

  5. Cold hardiness in molluscs

    NASA Astrophysics Data System (ADS)

    Ansart, Armelle; Vernon, Philippe

    2003-05-01

    Molluscs inhabit all types of environments: seawater, intertidal zone, freshwater and land, and of course may have to deal with subzero temperatures. Ectotherm animals survive cold conditions by avoiding it by extensive supercooling (freezing avoidant species) or by bearing the freezing of their extracellular body fluids (freezing tolerant species). Although some studies on cold hardiness are available for intertidal molluscs, they are scarce for freshwater and terrestrial ones. Molluscs often exhibit intermediary levels of cold hardiness, with a moderate or low ability to supercool and a limited survival to the freezing of their tissues. Several factors could be involved: their dependence on water, their ability to enter dormancy, the probability of inoculative freezing in their environment, etc. Size is an important parameter in the development of cold hardiness abilities: it influences supercooling ability in land snails, which are rather freezing avoidant and survival to ice formation in intertidal organisms, which generally tolerate freezing.

  6. Instability of evaporation fronts in the interstellar medium

    SciTech Connect

    Kim, Jeong-Gyu; Kim, Woong-Tae E-mail: wkim@astro.snu.ac.kr

    2013-12-10

    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 {sub B} cm{sup –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.

  7. Effects of recent warm and cold spells on European plant phenology.

    PubMed

    Menzel, Annette; Seifert, Holm; Estrella, Nicole

    2011-11-01

    Climate change is already altering the magnitude and/or frequency of extreme events which will in turn affect plant fitness more than any change in the average. Although the fingerprint of anthropogenic warming in recent phenological records is well understood, the impacts of extreme events have been largely neglected. Thus, the temperature response of European phenological records to warm and cold spells was studied using the COST725 database. We restricted our analysis to the period 1951-2004 due to better spatial coverage. Warm and cold spells were identified using monthly mean ENSEMBLES temperature data on a 0.5° grid for Europe. Their phenological impact was assessed as anomalies from maps displaying mean onsets for 1930-1939. Our results clearly exhibit continental cold spells predominating in the period 1951-1988, especially during the growing season, whereas the period from 1989 onwards was mainly characterised by warm spells in all seasons. The impacts of these warm/cold spells on the onset of phenological seasons differed strongly depending on species, phase and timing. "False" phases such as the sowing of winter cereals hardly reacted to summer warm/cold spells; only the sowing of summer cereals mirrored spring temperature warm/cold spells. The heading dates of winter cereals did not reveal any consistent results probably due to fewer warm/cold spells identified in the relevant late spring months. Apple flowering and the harvest of winter cereals were the best indicators of warm/cold spells in early spring and summer, also being spatially coherent with the patterns of warm/cold spells. PMID:21755278

  8. Satellite-sensed winter nocturnal temperature patterns of the Everglades Agricultural Area

    NASA Technical Reports Server (NTRS)

    Chen, E.; Bartholic, J. F.; Bill, R. G., Jr.; Sutherland, R. A.; Allen, L. H., Jr.

    1979-01-01

    Surface temperature patterns of drained organic soil farmland in the Everglades Agricultural Area south of Lake Okeechobee, Florida, were studied using GOES-1 satellite infrared digital data for the winters of 1976-77 and 1977-78. Local thermal features were explained in terms of soil types, soil depths and climate modification caused by organic soil drainage. A cold-prone area was delineated in the Everglades Agricultural Area with satellite data. The winter nighttime surface temperatures of this area were more characteristic of north central Florida, approximately 370 km further north, than of surrounding areas of mineral soil or undrained organic soil.

  9. Effects of winter feeding on growth body composition and processing traits of co-cultured blue catfish Ictalurus furcatus channel catfish I. punctatus and channel catfish x blue catfish hybrids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many catfish farmers do not feed or feed fish very infrequently during the winter months because feeding activity is reduced at cold water temperatures. However, studies have demonstrated that winter feeding can improve catfish weight gain and processing yield relative to not feeding. We compared ...

  10. 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...

  11. Ocean fronts trigger high latitude phytoplankton blooms

    E-print Network

    Taylor, John R.

    Density fronts are ubiquitous features of the upper ocean. Here, numerical simulations show that restratification at fronts inhibits vertical mixing, triggering phytoplankton blooms in low-light conditions. The stability ...

  12. Teaching in a Cold Environment.

    ERIC Educational Resources Information Center

    Ewert, Alan

    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:…

  13. Teaching in a Cold Environment.

    ERIC Educational Resources Information Center

    Ewert, Alan

    1979-01-01

    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)

  14. Understanding Colds: Anatomy of the Nose

    MedlinePLUS

    ... Colds Prevention Treatment Children Complications Special Features References Common Cold Understanding Colds Anatomy of the Nose The nose ... cm (3/8 inch) per minute. What a Common Cold Is A common cold is an illness caused ...

  15. Winter Snowfall Turns an Emerald White

    NASA Technical Reports Server (NTRS)

    2001-01-01

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

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

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

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

  16. Insulators for cold urban areas: The problem of Road Salt Ravi Gorur and Sreeram Venkataraman

    E-print Network

    Insulators for cold urban areas: The problem of Road Salt Ravi Gorur and Sreeram Venkataraman of insulators in winter due to road salt. We have started a research project at Arizona State University are more concerned with the effect that the road salts have on insulators, both ceramic and composite

  17. Foliar applied abscisic acid increases 'Chardonnay' grapevines (Vitis vinifera) bud freezing tolerance during Autumn cold acclimation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Economic loss due to cold weather events is a major constraint to winegrape-related industries where extreme and/or fluctuating winter temperatures induce injury and required remedial retraining and replanting increases production costs and lowers yield and fruit quality. The purpose of this study ...

  18. Cold moderators at ORNL

    SciTech Connect

    Lucas, A. T.

    1997-09-01

    The Advanced Neutron Source (ANS) cold moderators were not an 'Oak Ridge first', but would have been the largest both physically and in terms of cold neutron flux. Two cold moderators were planned each 410 mm in diameter and containing about 30L of liquid deuterium. They were to be completely independent of each other. A modular system design was used to provide greater reliability and serviceability. When the ANS was terminated, up–grading of the resident High Flux Isotope Reactor (HFIR) was examined and an initial study was made into the feasibility of adding a cold source. Because the ANS design was modular, it was possible to use many identical design features. Sub-cooled liquid at 4 bar abs was initially chosen for the HFIR design concept, but this was subsequently changed to 15 bar abs to operate above the critical pressure. As in the ANS, the hydrogen will operate at a constant pressure throughout the temperature range and a completely closed loop with secondary containment was adopted. The heat load of 2 kW made the heat flux comparable with that of the ANS. Subsequent studies into the construction of cryogenic moderators for the proposed new Synchrotron Neutron source indicated that again many of the same design concepts could be used. By connecting the two cold sources together in series, the total heat load of 2 kW is very close to that of the HFIR allowing a very similar supercritical hydrogen system to be configured. The two hydrogen moderators of the SNS provide a comparable heat load to the HFIR moderator. It is subsequently planned to connect the two in series and operate from a single cold loop system, once again using supercritical hydrogen. The spallation source also provided an opportunity to re-examine a cold pellet solid methane moderator operating at 20K.

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

    ERIC Educational Resources Information Center

    Matthews, Bruce E.; And Others

    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…

  20. Wintering ecology of adult North American ospreys

    USGS Publications Warehouse

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

    2014-01-01

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

  1. Firing up the front line.

    PubMed

    Katzenbach, J R; Santamaria, J A

    1999-01-01

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

  2. 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...

  3. Differences in vernalization duration requirement in soft winter wheat associated with variation at the vrn-B1 locus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In winter wheat (Triticum aestivum L.), the timing of flowering initiation is governed by the action two main environmentally controlled group of genes; vernalization that defines a plant’s requirement for a prolonged exposure to cold temperatures and photoperiod sensitivity defining the need for a ...

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

    NASA Astrophysics Data System (ADS)

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

    2014-08-01

    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.

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

    PubMed Central

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

    2013-01-01

    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

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

    PubMed

    Brightwell, Robert J; Silverman, Jules

    2011-10-01

    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

  7. Winter diversity and expression of proteorhodopsin genes in a polar ocean.

    PubMed

    Nguyen, Dan; Maranger, Roxane; Balagué, Vanessa; Coll-Lladó, Montserrat; Lovejoy, Connie; Pedrós-Alió, Carlos

    2015-08-01

    Mixotrophy is a valuable functional trait used by microbes when environmental conditions vary broadly or resources are limited. In the sunlit waters of the ocean, photoheterotrophy, a form of mixotrophy, is often mediated by proteorhodopsin (PR), a seven helices transmembrane protein binding the retinal chromophore. Altogether, they allow bacteria to capture photic energy for sensory and proton gradient formation cell functions. The seasonal occurrence and diversity of the gene coding for PR in cold oligotrophic polar oceans is not known and PR expression has not yet been reported. Here we show that PR is widely distributed among bacterial taxa, and that PR expression decreased markedly during the winter months in the Arctic Ocean. Gammaproteobacteria-like PR sequences were always dominant. However, within the second most common affiliation, there was a transition from Flavobacteria-like PR in early winter to Alphaproteobacteria-like PR in late winter. The phylogenetic shifts followed carbon dynamics, where patterns in expression were consistent with community succession, as identified by DNA community fingerprinting. Although genes for PR were always present, the trend in decreasing transcripts from January to February suggested reduced functional utility of PR during winter. Under winter darkness, sustained expression suggests that PR may continue to be useful for non-ATP forming functions, such as environmental sensing or small solute transport. The persistence of PR expression in winter among some bacterial groups may offer a competitive advantage, where its multifunctionality enhances microbial survival under harsh polar conditions. PMID:25700336

  8. Relations between winter 700-mb height anomalies and mass balance of South Cascade Glacier, Washington

    SciTech Connect

    McCabe, G.J.; Fountain, A.G.

    1995-12-31

    The yearly net mass balance of South Cascade Glacier, Washington, decreased during the mid-1970`s. Results show that the decrease is primarily caused by a significant decrease in the winter mass balance. The decrease in winter mass balance is caused, in part, by changes in winter mean atmospheric circulation that began during the mid-1970`s. Since the mid-1970`s, there has been an increase in winter mean atmospheric pressure over western Canada and the northern western contiguous US and a decrease in winter mean atmospheric pressure in the eastern North Pacific Ocean centered near the Aleutian islands. These changes in atmospheric circulation indicate a decrease in the movement of storms and moisture from the Pacific Ocean into the western contiguous US. In addition, the increase in atmospheric pressure over western Canada and the northern western contiguous US indicates an increase in subsidence, which results in a warming and drying of the air that further reduces precipitation and also increases the ratio of rain to snow during the cold season. These factors contribute to below-average winter mass balances.

  9. Polar Stratospheric Cloud formation and denitrification during the Arctic winter 2009/2010 and 2010/2011

    NASA Astrophysics Data System (ADS)

    Khosrawi, Farahnaz; Urban, Joachim; Pitts, Michael C.; Kirner, Oliver; Braesicke, Peter; Santee, Michelle L.; Manney, Gloria L.; Murtagh, Donal

    2015-04-01

    The sedimentation of HNO3 containing polar stratospheric cloud particles leads to a permanent removal of HNO3 from the stratosphere. The so-called denitrification is an effect that plays an important role in stratospheric ozone depletion. The Arctic winter 2009/2010 and 2010/2011 were both quite unique. The Arctic winter 2010/2011 was one of the coldest winters on record leading to the strongest depletion of ozone measured in the Arctic. Though the Arctic winter 2009/2010 was rather warm in the climatological sense it was distinguished by an exceptionally cold stratosphere from mid December 2009 to mid January 2010 leading to prolonged PSC formation and significant denitrification. Model simulations and space-borne observations are used to investigate PSC formation and denitrification during these two winters. Model simulations were performed with the atmospheric chemistry-climate model ECHAM5/MESSy Atmospheric Chemistry (EMAC) and compared to observations by the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations Satellite (CALIPSO) and the Odin Sub-Millimetre Radiometer (Odin/SMR) as well as with observations from the Microwave Limb Sounder on Aura (Aura/MLS). 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. Although the PSC season during the Arctic winter 2009/2010 was much shorter than in 2010/2011, denitrification during the Arctic winter 2009/2010 was similar in magnitude than during 2010/2011.

  10. Dartmouth College Winter Carnival Ice Sculpture Contest

    E-print Network

    Dartmouth College Winter Carnival Ice Sculpture Contest February 5-6, 2015 Please read through Muñiz. Background: Winter Carnival is one of Dartmouth's greatest traditions. The snow sculpture years, organizations across campus sponsored smaller thematic sculptures to complement the weekend

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

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

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

  12. Winter 2008 newsletter of the

    E-print Network

    Martin, Gail

    Winter 2008 Issue #17 newsletter of the UCSF Foundation Also in this issue: Bequest Supports of the next decade." Rutter believed that in order for basic science to contribute to medicine and human lives to clone the insulin gene and develop the process for making a vaccine against the hepatitis B virus

  13. Reducing winter injury in blackberries

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  14. Winter Storms For More Information

    E-print Network

    of these threats. · A major winter storm can last for several days and be accompanied by high winds, freezing rain on the ground picked up by the wind. SNOW SQUALLS: Brief, intense snow showers accompanied by strong, gusty that year. Photos courtesy of Mt. Baker Ski Area. 3 NWS #12;Rain Freezing Rain Sleet Snow Frozen

  15. WINTER 2012 ANDREW YOUNG SCHOOL

    E-print Network

    Frantz, Kyle J.

    Meg Buscema Carolyn Richardson Photographers Cover: New unit leaders Brian Payne (CJ&C) and NancyBriefing THE WINTER 2012 ANDREW YOUNG SCHOOL O F P O L I C Y S T U D I E S Welcoming Criminal Walker Dean Robert E. Moore Associate Dean Cynthia Searcy Assistant Dean for Academic Programs Avani

  16. Recent contrasting winter temperature changes over North America linked to enhanced positive Pacific-North American pattern

    NASA Astrophysics Data System (ADS)

    Liu, Zhongfang; Jian, Zhimin; Yoshimura, Kei; Buenning, Nikolaus H.; Poulsen, Christopher J.; Bowen, Gabriel J.

    2015-09-01

    Recently enhanced contrasts in winter (December-January-February) mean temperatures and extremes (cold southeast and warm northwest) across North America have triggered intensive discussion both within and outside of the scientific community, but the mechanisms responsible for these contrasts remain unresolved. Here we use a combination of observations and reanalysis data sets to show that the strengthened contrasts in winter mean temperatures and extremes across North America are closely related to an enhancement of the positive Pacific-North American (PNA) pattern during the second half of the 20th century. Recent intensification of positive PNA events is associated with amplified planetary waves over North America, driving cold-air outbreaks into the southeast and warm tropical/subtropical air into the northwest. This not only results in a strengthened winter mean temperature contrast but increases the occurrence of the opposite-signed extremes in these two regions.

  17. The hard winter of 1880-1881: Climatological context and communication via a Laura Ingalls Wilder narrative

    NASA Astrophysics Data System (ADS)

    Boustead, Barbara E.

    The Hard Winter of 1880-1881 was featured in the Laura Ingalls Wilder historical fiction account, The Long Winter, as well as in several town histories across the region. Both meteorological records and historical accounts indicate that the winter was particularly long, snowy, and cold. The question of how "hard" a winter is for a given location depends on the climatological context, which relies on an objective characterization of winter severity. The Accumulated Winter Season Severity Index (AWSSI) allows comparison of the winter of 1880-1881 among sites across the region, as well as in the context of the period of record, to quantify its severity. Additionally, investigating the impacts of both the El Nino/Southern Oscillation (ENSO) and the North Atlantic Oscillation (NAO) in the central United States provides context for the influence of both a strongly negative NAO and an El Nino event during the winter of 1880-1881. With an understanding of the climatological factors influencing the Hard Winter, along with the context for its severity, a more thorough analysis then was conducted to quantify and describe its severity. The connection of the winter of 1880-1881 to a popular book written by an author who is a cultural icon provides a natural vehicle with which to communicate weather and climate concepts to multiple non-technical audiences. The communication of complex weather and climate concepts is a well-documented challenge. One method to bridge between science concepts and public understanding is to relate those concepts to familiar subjects and stories, including Laura Ingalls Wilder's books. A narrative constructed around the books, particularly The Long Winter, provides a means of audience engagement and interest in weather- and climate-related topics, which was at least partially quantified by surveying audiences of the narrative. Overall, the scientific background, combined with a familiar narrative voice, provides a means to transmit weather and climate.

  18. 33 CFR 100.109 - Winter Harbor Lobster Boat Race, Winter Harbor, ME.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...1 2010-07-01 2010-07-01 false Winter Harbor Lobster Boat Race, Winter Harbor, ME. 100.109 Section 100...SAFETY OF LIFE ON NAVIGABLE WATERS § 100.109 Winter Harbor Lobster Boat Race, Winter Harbor, ME. (a) Regulated...

  19. Coherent Forward Broadening in Cold Atom Clouds

    E-print Network

    Sutherland, R T

    2015-01-01

    It is shown that homogeneous line-broadening in a diffuse cold atom cloud is proportional to the resonant optical depth of the cloud. Further, it is demonstrated how the strong directionality of the coherent interactions causes the cloud's spectra to depend strongly on its shape, even when the cloud is held at constant densities. These two numerical observations can be predicted analytically by extending the single photon wave-function model. Lastly, elongating a cloud along the line of laser propagation causes the excitation probability distribution to deviate from the exponential decay predicted by the Beer-Lambert law to the extent where the atoms in the back of the cloud are more excited than the atoms in the front. These calculations are conducted at low densities relevant to recent experiments.

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

    PubMed Central

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

    2013-01-01

    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 5 years, 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

  1. Winter cover crops influence Amaranthus palmeri establishment

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  2. The Winter Environment. Environmental Education Curriculum.

    ERIC Educational Resources Information Center

    Topeka Public Schools, KS.

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

  3. WINTER WHEAT VARIETIES Performance Evaluation and Recommendations

    E-print Network

    Dyer, Bill

    2014 WINTER WHEAT VARIETIES Performance Evaluation and Recommendations http be found at a link on: #12;2014 Recommended Varieties: Hard Winter Wheat for Montana by District Variety Districts (see map on cover) 1 2 3 4 5 6 Hard Red Winter Wheat Northwest Southwest Southeast Central North

  4. WINTER WHEAT VARIETIES Performance Evaluation and Recommendations

    E-print Network

    Dyer, Bill

    2013 WINTER WHEAT VARIETIES Performance Evaluation and Recommendations AND DISTRICTS and Hard White Winter Wheat Bearpaw ++2/ D D D Bynum (P) 2/ + D D Carter (P)+ D D D D D CDC Falcon (P)+ DI Yellowstone + D D D D D Soft White Winter Wheat Eltan D D Hill 81 D D Lewjain D Malcolm D D HWW = Hard White

  5. The effect of cold protective clothing on comfort and perception of performance.

    PubMed

    Jussila, Kirsi; Valkama, Anita; Remes, Jouko; Anttonen, Hannu; Peitso, Ari

    2010-01-01

    The physiological properties of clothing designed to provide protection against cold, windy and damp conditions affect comfort. The weight, thickness, stiffness of the fabrics and friction between the clothing layers affect physical performance. The comfort and perception of performance associated with 3 military winter combat clothing systems from different decades (the new M05 system, the previous M91 system and traditional clothing) were observed during a winter military manoeuvre. Subjective experiences concerning comfort and performance were recorded for 319 subjects using questionnaires. The most challenging conditions for comfort and performance were perspiration in the cold and external moisture. The new M05 system provided warmer thermal sensations (p < .010), dryer moisture sensations in the presence of external dampness (p < .001), dryer perspiration moisture sensations (p < .050) and better perception of physical (p < .001) and mental performance (p < .001) than the other systems. Careful development of the clothing system guarantees good comfort and performance during cold exposure. PMID:20540839

  6. Warmer winters modulate life history and energy storage but do not affect sensitivity to a widespread pesticide in an aquatic insect.

    PubMed

    Arambourou, Hélène; Stoks, Robby

    2015-10-01

    Despite the increased attention for the effects of pesticides under global warming no studies tested how winter warming affects subsequent sensitivity to pesticides. Winter warming is expected to cause delayed negative effects when it increases metabolic rates and thereby depletes energy reserves. Using a common-garden experiment, we investigated the combined effect of a 4 °C increase in winter temperature and subsequent exposure to chlorpyrifos in the aquatic larvae of replicated low- and high-latitude European populations of the damselfly Ischnura elegans. The warmer winter (8 °C) resulted in a higher winter survival and higher growth rates compared to the cold winter (4 °C) commonly experienced by European high-latitude populations. Low-latitude populations were better at coping with the warmer winter, indicating thermal adaptation to the local winter temperatures. Subsequent chlorpyrifos exposure at 20 °C induced strong negative effects on survival, growth rate, lipid content and acetylcholinesterase activity while phenoloxidase activity increased. These pesticide effects were not affected by winter warming. Our results suggest that for species where winter warming has positive effects on life history, no delayed effects on the sensitivity to subsequent pesticide exposure should be expected. PMID:26261878

  7. Ice-dependent winter survival of juvenile Atlantic salmon.

    PubMed

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

    2013-03-01

    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, 70°N), 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

  8. Ice-dependent winter survival of juvenile Atlantic salmon

    PubMed Central

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

    2013-01-01

    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, 70°N), 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

  9. Northern Front Range air quality study: Apportionment of carbonaceous particles

    SciTech Connect

    Fujita, E.M.; McDonald, J.D.; Hayes, T.L.; Zielinska, B.; Sagebiel, J.C.; Chow, J.C.; Watson, J.G.; Lawson, D.R.

    1998-12-31

    The Chemical Mass Balance (CMB) receptor model was applied to source profiles and ambient measurements taken during Winter 1997 at locations near Denver, CO. Chemical speciation included particulate and gaseous polycyclic aromatic hydrocarbons and other organic compounds (e.g., methoxylated phenols, hopanes, steranes, sterols, and lactones) in combination with inorganic particulate species and total elemental and organic carbon. Emissions were tested for more than 200 in-use vehicles, including heavy-duty trucks and buses, light-duty diesel vehicles and, smoking and high emitting gasoline vehicles. Separate profiles were obtained for light-duty vehicle for cold-start and hot stabilized modes. Wood burning and meat cooking emissions were also characterized. Motor vehicles account for about 85 percent of the ambient PM2.5 carbon in Denver and about 75 percent in areas north of Denver. Light-duty gasoline vehicles are the major sources of PM2.5 carbon in Denver, with cold starts (or high emitters) and smokers contributing about 30 percent each to PM2.5 carbon. Normal hot stabilized emissions and diesel exhaust contribute about 5 and 17 percent, respectively, and paved road dust contributes less than 5 percent. Smokers, and cold starts (or high emitters) are the largest contributors to PM2.5 organic carbon, and diesel exhaust, and cold starts (or high emitters) are the largest contributors to PM2.5 elemental carbon. PM2.5 emissions from the exhaust of light-duty gasoline vehicles are seriously underestimated in current inventories relative to diesel exhaust. Diesel exhaust, which is about two-thirds of the on-road vehicle PM2.5 emissions in the current inventory, account for only 18 percent according to the ambient source apportionment.

  10. Distribution patterns of American black duck and mallard winter band recoveries

    USGS Publications Warehouse

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

    1988-01-01

    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.

  11. Cold surge: a sudden and spatially varying threat to health?

    PubMed Central

    Wu, Pei-Chih; Chen, Vivian Yi-Ju; Su, Huey-Jen

    2011-01-01

    While cold surge is one of the most conspicuous features of the winter monsoon in East Asia, its impact on human health remains underexplored. Based on the definition by the Central Weather Bureau in Taiwan, we identified four cold surges between 2000 and 2003 and collected the cardiovascular disease mortality data two weeks before and two weeks after these events. We attempted to answer the following research questions: 1) whether the cold surges impose an adverse and immediate effect on cardiovascular mortality; 2) whether the people living in temperate zones have a higher tolerance of extreme temperature drop than do those in the subtropics. With geographic weighting techniques, we not only found that the cardiovascular disease mortality rates increased significantly after the cold surges, but also discovered a spatially varying pattern of tolerance to cold surges. Even within a small study area such as Taiwan, human reaction to severe weather drop differs across space. Needless to say, in the U.S., these findings should be considered in redirecting policy to address populations living in warm places when extreme temperature drops occur. PMID:19162302

  12. Seasonal and decadal variations of ice-shelf front positions in Dronning Maud Land, East Antarctica

    NASA Astrophysics Data System (ADS)

    Deschamps-Berger, César; Matsuoka, Kenichi; Moholdt, Geir; König, Max

    2015-04-01

    Most of recent rapid changes of the Antarctic ice sheet have been triggered from the ice shelves through enhanced basal melting and/or iceberg calving. The Dronning Maud Land (DML) coastal region is encompassed by many semi-continuous ice shelves, and its mass balance is thus particularly sensitive to changes in the coastal environment. Better knowledge on the region's ice shelves is necessary to predict future behavior of the ice sheet. Here, we present temporal changes of the ice-shelf front positions in DML over the past decade. RADARSAT-2 imagery was used to delineate the front positions at six times between August 2012 and December 2013. Displacements of the ice-shelf edges over this period are mostly in good agreement with displacements derived from satellite interferometery observations. Yet we observe in several sub-regions that displacement during the austral summer is larger than that during the winter. We also observe winter-growth of sea ice from the ice-shelf fronts and outwards to icebergs that are grounded on the continental shelf. Fast sea ice growth and break-up is seasonal and could influence ice-shelf flow close to the fronts. On a longer term, comparison between 2004 and 2009 MOA coast line datasets and our 2012-13 dataset highlights the general stability of the area in the past decade. Between 2004 and 2013, only six ice shelves experienced considerable retreat due to calving of tabular icebergs, leaving the remaining 90 % of the region's ice-shelf fronts advancing in accordance with their local flow.

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

    PubMed Central

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

    2011-01-01

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

  14. Seasonal variation in nutritional characteristics of the diet of greater white-fronted geese

    USGS Publications Warehouse

    Ely, C.R.; Raveling, D.G.

    2011-01-01

    We studied diet and habitat use of greater white-fronted geese (Anser albifrons) from autumn through spring on their primary staging and wintering areas in the Pacific Flyway, 1979-1982. There have been few previous studies of resource use and forage quality of wintering greater white-fronted geese in North America, and as a consequence there has been little empirical support for management practices pertaining to habitat conservation of this broadly distributed species. Observations of >2,500 flocks of geese and collections of foraging birds revealed seasonal and geographic variation in resource use reflective of changes in habitat availability, selection, and fluctuating physiological demands. Autumn migrants from Alaska arrived first in the Klamath Basin of California and southern Oregon, where they fed on barley, oats, wheat, and potatoes. Geese migrated from the Klamath Basin into the Central Valley of California in late autumn where they exploited agricultural crops rich in soluble carbohydrates, with geese in the Sacramento Valley feeding almost exclusively on rice and birds on the Sacramento-San Joaquin Delta primarily utilizing corn. White-fronted geese began their northward migration in late winter, and by early spring most had returned to the Klamath Basin where 37% of flocks were found in fields of new growth cultivated and wild grasses. Cereal grains and potatoes ingested by geese were low in protein (7-14%) and high in soluble nutrients (17-47% neutral detergent fiber [NDF]), whereas grasses were low in available energy (47-49% NDF) but high in protein (26-42%). Greater white-fronted geese are generalist herbivores and can exploit a variety of carbohydrate-rich cultivated crops, likely making these geese less susceptible to winter food shortages than prior to the agriculturalization of the North American landscape. However, agricultural landscapes can be extremely dynamic and may be less predictable in the long-term than the historic environments to which geese are adapted. Thus far greater white-fronted geese have proved resilient to changes in land cover in the Pacific Flyway and by altering their migration regime have even been able to adapt to changes in the availability of suitable forage crops. ?? 2010 The Wildlife Society.

  15. Seasonal variation in nutritional characteristics of the diet of greater white-fronted geese

    USGS Publications Warehouse

    Ely, Craig R.; Raveling, Dennis G.

    2011-01-01

    We studied diet and habitat use of greater white-fronted geese (Anser albifrons) from autumn through spring on their primary staging and wintering areas in the Pacific Flyway, 1979-1982. There have been few previous studies of resource use and forage quality of wintering greater white-fronted geese in North America, and as a consequence there has been little empirical support for management practices pertaining to habitat conservation of this broadly distributed species. Observations of >2,500 flocks of geese and collections of foraging birds revealed seasonal and geographic variation in resource use reflective of changes in habitat availability, selection, and fluctuating physiological demands. Autumn migrants from Alaska arrived first in the Klamath Basin of California and southern Oregon, where they fed on barley, oats, wheat, and potatoes. Geese migrated from the Klamath Basin into the Central Valley of California in late autumn where they exploited agricultural crops rich in soluble carbohydrates, with geese in the Sacramento Valley feeding almost exclusively on rice and birds on the Sacramento-San Joaquin Delta primarily utilizing corn. White-fronted geese began their northward migration in late winter, and by early spring most had returned to the Klamath Basin where 37% of flocks were found in fields of new growth cultivated and wild grasses. Cereal grains and potatoes ingested by geese were low in protein (7-14%) and high in soluble nutrients (17-47% neutral detergent fiber [NDF]), whereas grasses were low in available energy (47-49% NDF) but high in protein (26-42%). Greater white-fronted geese are generalist herbivores and can exploit a variety of carbohydrate-rich cultivated crops, likely making these geese less susceptible to winter food shortages than prior to the agriculturalization of the North American landscape. However, agricultural landscapes can be extremely dynamic and may be less predictable in the long-term than the historic environments to which geese are adapted. Thus far greater white-fronted geese have proved resilient to changes in land cover in the Pacific Flyway and by altering their migration regime have even been able to adapt to changes in the availability of suitable forage crops. © 2010 The Wildlife Society.

  16. Interannual variation of East Asian Winter Monsoon and ENSO

    SciTech Connect

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

    1996-12-01

    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.

  17. Cold tolerance of the maize orange leafhopper, Cicadulina bipunctata.

    PubMed

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

    2014-08-01

    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 15°C 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 5°C and exposure duration to the temperature. The temperature of crystallization of adult females was approximately -19°C but temperatures in southern temperate Japan rarely dropped below -10°C 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

  18. The Remarkable 2003-2004 Winter and Other Recent Warm Winters in the Arctic Stratosphere Since the Late 1990s

    NASA Technical Reports Server (NTRS)

    Manney, Gloria L.; Krueger, Kirstin; Sabutis, Joseph L.; Sena, Sara Amina; Pawson, Steven

    2004-01-01

    The 2003-2004 Arctic winter was remarkable in the 40-year record of meteorological analyses. A major warming beginning in early January 2004 led to nearly two months of vortex disruption with high-latitude easterlies in the middle to lower stratosphere. The upper stratospheric vortex broke up in late December, but began to recover by early January, and in February and March was the strongest since regular observations began in 1979. The lower stratospheric vortex broke up in late January. Comparison with two previous years, 1984-1985 and 1986-1987, with prolonged mid-winter warming periods shows unique characteristics of the 2003-2004 warming period: The length of the vortex disruption, the strong and rapid recovery in the upper stratosphere, and the slow progression of the warming from upper to lower stratosphere. January 2004 zonal mean winds in the middle and lower stratosphere were over two standard deviations below average. Examination of past variability shows that the recent frequency of major stratospheric warmings (seven in the past six years) is unprecedented. Lower stratospheric temperatures were unusually high during six of the past seven years, with five having much lower than usual potential for PSC formation and ozone loss (nearly none in 1998-1999, 2001-2002 and 2003-2004, and very little in 1997-1998 and 2000-2001). Middle and upper stratospheric temperatures, however, were unusually low during and after February. The pattern of five of the last seven years with very low PSC potential would be expected to occur randomly once every approximately 850 years. This cluster of warm winters, immediately following a period of unusually cold winters, may have important implications for possible changes in interannual variability and for determination and attribution of trends in stratospheric temperatures and ozone.

  19. Cold spray nozzle design

    DOEpatents

    Haynes, Jeffrey D. (Stuart, FL); Sanders, Stuart A. (Palm Beach Gardens, FL)

    2009-06-09

    A nozzle for use in a cold spray technique is described. The nozzle has a passageway for spraying a powder material, the passageway having a converging section and a diverging section, and at least the diverging section being formed from polybenzimidazole. In one embodiment of the nozzle, the converging section is also formed from polybenzimidazole.

  20. Teaching "In Cold Blood."

    ERIC Educational Resources Information Center

    Berbrich, Joan D.

    1967-01-01

    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…

  1. Recent Cold War Studies

    ERIC Educational Resources Information Center

    Pineo, Ronn

    2003-01-01

    Cold War historiography has undergone major changes since the 1991 collapse of the Soviet Union. For two years (1992-1993) the principal Soviet archives fell open to scholars, and although some of the richest holdings are now once again closed, new information continues to find its way out. Moreover, critical documentary information has become…

  2. Disinfestation with Cold

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This book chapter by Neil Heather and Guy Hallman, in “Pest Management and Phytosanitary Trade Barriers,” CABI Press, reviews the history and current status of cold as a phytosanitary treatment and makes recommendations for future research. The recent problems with Mediterranean fruit fly in Clemen...

  3. Mechanism of Convective Cloud Triggering and Organization By Cold Pools during Dynamo

    NASA Astrophysics Data System (ADS)

    Feng, Z.; Hagos, S.; Burleyson, C. D.; Rowe, A.; Martini, M.; de Szoeke, S. P.

    2014-12-01

    Cold pools resulting from evaporation of rain in convective downdrafts are important components of meso-scale organization in the tropics. Using combinations of cloud resolving regional model simulations and radar and surface observations obtained during the CINDY2011/DYNAMO/AMIE field campaign, we investigate mechanism of convective cloud triggering and organization at the edge of cold pools. The model simulated cloud population and cold pool statistics compare well with the observations. Comparison of thermodynamics and dynamic conditions at the boundaries of isolated and intersecting cold pools reveals, that deep convection is mainly attributed to larger cloud clusters formed at intersecting cold pool boundaries, as a result of reduced entrainment of environmental air, while stronger sub-cloud layer forced updraft by colliding gust fronts played a secondary role.

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

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

    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.

  5. Arctic winter 2010/2011 at the brink of an ozone hole

    NASA Astrophysics Data System (ADS)

    Sinnhuber, B.-M.; Stiller, G.; Ruhnke, R.; von Clarmann, T.; Kellmann, S.; Aschmann, J.

    2011-12-01

    The Arctic stratospheric winter of 2010/2011 was one of the coldest on record with a large loss of stratospheric ozone. Observations of temperature, ozone, nitric acid, water vapor, nitrous oxide, chlorine nitrate and chlorine monoxide from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) onboard ENVISAT are compared to calculations with a chemical transport model (CTM). There is overall excellent agreement between the model calculations and MIPAS observations, indicating that the processes of denitrification, chlorine activation and catalytic ozone depletion are sufficiently well represented. Polar vortex integrated ozone loss reaches 120 Dobson Units (DU) by early April 2011. Sensitivity calculations with the CTM give an additional ozone loss of about 25 DU at the end of the winter for a further cooling of the stratosphere by 1 K, showing locally near-complete ozone depletion (remaining ozone <200 ppbv) over a large vertical extent from 16 to 19 km altitude. In the CTM a 1 K cooling approximately counteracts a 10% reduction in stratospheric halogen loading, a halogen reduction that is expected to occur in about 13 years from now. These results indicate that severe ozone depletion like in 2010/2011 or even worse could appear for cold Arctic winters over the next decades if the observed tendency for cold Arctic winters to become colder continues into the future.

  6. Effects of ice and floods on vegetation in streams in cold regions: implications for climate change

    PubMed Central

    Lind, Lovisa; Nilsson, Christer; Weber, Christine

    2014-01-01

    Riparian zones support some of the most dynamic and species-rich plant communities in cold regions. A common conception among plant ecologists is that flooding during the season when plants are dormant generally has little effect on the survival and production of riparian vegetation. We show that winter floods may also be of fundamental importance for the composition of riverine vegetation. We investigated the effects of ice formation on riparian and in-stream vegetation in northern Sweden using a combination of experiments and observations in 25 reaches, spanning a gradient from ice-free to ice-rich reaches. The ice-rich reaches were characterized by high production of frazil and anchor ice. In a couple of experiments, we exposed riparian vegetation to experimentally induced winter flooding, which reduced the dominant dwarf-shrub cover and led to colonization of a species-rich forb-dominated vegetation. In another experiment, natural winter floods caused by anchor-ice formation removed plant mimics both in the in-stream and in the riparian zone, further supporting the result that anchor ice maintains dynamic plant communities. With a warmer winter climate, ice-induced winter floods may first increase in frequency because of more frequent shifts between freezing and thawing during winter, but further warming and shortening of the winter might make them less common than today. If ice-induced winter floods become reduced in number because of a warming climate, an important disturbance agent for riparian and in-stream vegetation will be removed, leading to reduced species richness in streams and rivers in cold regions. Given that such regions are expected to have more plant species in the future because of immigration from the south, the distribution of species richness among habitats can be expected to show novel patterns. PMID:25505542

  7. Effects of ice and floods on vegetation in streams in cold regions: implications for climate change.

    PubMed

    Lind, Lovisa; Nilsson, Christer; Weber, Christine

    2014-11-01

    Riparian zones support some of the most dynamic and species-rich plant communities in cold regions. A common conception among plant ecologists is that flooding during the season when plants are dormant generally has little effect on the survival and production of riparian vegetation. We show that winter floods may also be of fundamental importance for the composition of riverine vegetation. We investigated the effects of ice formation on riparian and in-stream vegetation in northern Sweden using a combination of experiments and observations in 25 reaches, spanning a gradient from ice-free to ice-rich reaches. The ice-rich reaches were characterized by high production of frazil and anchor ice. In a couple of experiments, we exposed riparian vegetation to experimentally induced winter flooding, which reduced the dominant dwarf-shrub cover and led to colonization of a species-rich forb-dominated vegetation. In another experiment, natural winter floods caused by anchor-ice formation removed plant mimics both in the in-stream and in the riparian zone, further supporting the result that anchor ice maintains dynamic plant communities. With a warmer winter climate, ice-induced winter floods may first increase in frequency because of more frequent shifts between freezing and thawing during winter, but further warming and shortening of the winter might make them less common than today. If ice-induced winter floods become reduced in number because of a warming climate, an important disturbance agent for riparian and in-stream vegetation will be removed, leading to reduced species richness in streams and rivers in cold regions. Given that such regions are expected to have more plant species in the future because of immigration from the south, the distribution of species richness among habitats can be expected to show novel patterns. PMID:25505542

  8. Ion acceleration in dipolarization fronts

    NASA Astrophysics Data System (ADS)

    Birn, J.; Hesse, M.

    2014-12-01

    The electric field associated with flow bursts and dipolarization fronts has been shown to be an efficient mechanism for producing energetic ions and electrons. Using an MHD simulation of magnetotail reconnection, flow bursts and dipolarization, we investigate the acceleration of test particles to suprathermal energies. Particular emphasis of this presentation is on spatial, temporal, and angular variations of the modeled energetic ion fluxes. The test particle simulations reproduce characteristic features of observed injection events, such as a fast rise of energetic particle fluxes, limitations in energy, and demonstrate the large variability of energetic ion features.

  9. Prescription Drugs and Cold Medicines

    MedlinePLUS

    ... Abuse » Prescription Drugs & Cold Medicines Prescription Drugs & Cold Medicines Email Facebook Twitter What is Prescription Drug Abuse: ... treatment of addiction. Read more Safe Disposal of Medicines Disposal of Unused Medicines: What You Should Know ( ...

  10. Cold Weather and Cardiovascular Disease

    MedlinePLUS

    ... High Blood Pressure Tools & Resources Stroke More Cold Weather and Cardiovascular Disease Updated:Sep 16,2015 Th ... Heart Health • Watch, Learn & Live Animations Library Cold Weather Fitness Guide Popular Articles 1 Understanding Blood Pressure ...

  11. Accidental hypothermia and death from cold in urban areas

    NASA Astrophysics Data System (ADS)

    Tanaka, Masatoshi; Tokudome, Shogo

    1991-12-01

    Hypothermia is considered a sericus problem in big cities. In order to clarify factors contributing to urban hypothermia and death from cold which will continue to be an issue in cities in the future, we analyzed autopsy reports recorded in the Tokyo Medical Examiner's Office from 1974 to 1983. In a total of 18346 autopsy reports 157 deaths had been diagnosed as due to exposure to cold. Of these cases, the greatest number were males in their forties and fifties, and most of these were inebriated and/or homeless. Eighty-four perent of urban hypothermia cases occurred when the outdoor temperature was below 5°C, and 50% of deaths from cold occurred when the outdoor temperature was between 0° and 5°C. There were no incidences of death from cold when the minimum outdoor temperature had remained above 16°C. Seventy-four percent of deaths from cold occurred during the winter months of December, January and February, and most of the remaining deaths occurred in March and November. There were no deaths from cold from June to August. More than half of all deaths from cold occurred from 3.00 a.m. to 9.00 a.m., with the peak occurring at 5.00 a.m. A blood alcohol concentration of over 2.5 mg/ml had often been found in those in their forties and fifties who had died from hypothermia, and autopsy had often revealed disorders of the liver, digestive system, and circulatory system. Chronic lesions of the liver, probably due to alcoholism, were found in many cases; few cases showed no evidence of alcoholism and these were significantly different from the former group.

  12. Auslegung: a journal of philosophy, Volume 13, Number 1 (Winter, 1986): Front Matter

    E-print Network

    David Larson, University of Kansas Co-Editor Michael Hinz, University of Kansas Book Review Editor...Bill Martin, University of Kansas Business Manager..Albert Cinelli, University of Kansas Assistant Editors Harold W. Baldwin, University of South... Editors Richard Cole, University of Kansas Richard T. De George, University of Kansas Anthony C. Genova, University of Kansas Rex Martin, University of Kansas Nancy Simco, Memphis State University Cover Design Typist Clancey Maloney ...Janice Criss...

  13. Auslegung: a journal of philosophy, Volume 29, Number 1 (Fall/Winter, 2007): Front Matter

    E-print Network

    @yahoo.com http:// www.ku.edu/ ~ philos/Auslegung/ Subscription information: Individuals, $12; Institutions, $16; Students and Unemployed Philosophers, $10; all subscriptions outside the US and Canada add $2 for postage. All rights reserved, 2007...­ sion of any and all scholarly philosophical perspectives. The editors are primarily interested in publishing the work of new Ph.D's and advanced students pursuing a degree in Philosophy. However, all technically com­ petent philosophical work...

  14. Auslegung: a journal of philosophy, Volume 25, Number 1 (Winter/Spring, 2002): Front Matter

    E-print Network

    at: www.ukans.edu/~phil/Auslegung.html Or e-mail us at: auslegung@hotmail.com Auslegung gratefully acknowledges the support it receives from the University of Kansas Philosophy Department and the University of Kan­ sas Graduate Student Council...

  15. Auslegung: a journal of philosophy, Volume 26, Number 1 (Winter/Spring, 2003): Front Matter

    E-print Network

    for manuscripts to be returned to the author, return postage and specific mailing instructions must accompany submission. For information regarding Auslegung, please visit our web site at: www.ukans.edal~phillAuslegung.html Or e-mail us at: auslegung@hotmail.com...

  16. Auslegung: a journal of philosophy, Volume 8, Number 1 (Winter, 1981): Front Matter

    E-print Network

    Editors Jim Collins, University of Kansas Deborah Keithly, University of Kansas Assistant Editors..Charles Betros, Don Branson, Stephen H. Daniel, William F. Hamilton, Jack Horner, Brian Hutchinson, Joseph Koterski, David W. Nickel, Patrick... Volume 8, Number 1 AUSLEGUNG: A Journal of Philosophy Articles Robert S. Gall, Between Tradition and Critique: The Gadamer-Habermas Debate 5 Aryeh Botwinick, Hume on Is-Ought: A Reinterpretation 19 Bruce B. Suttle, Suicide: The Ultimate Inside...

  17. Mid-American Review of Sociology, Volume 4, Number 2 (WINTER, 1979): Front Matter

    E-print Network

    1979-01-01

    Edited at the Department of Sociology, University of Kansas Mid-American Review of Sociology GININELSON Book Review Editor MICHAEL G. LACY Editor-in-Chief LAURA GRAS Washington University GARY FOSTER Kansas State University Associate Editors... Edited at the Department of Sociology, University of Kansas Mid-American Review of Sociology GININELSON Book Review Editor MICHAEL G. LACY Editor-in-Chief LAURA GRAS Washington University GARY FOSTER Kansas State University Associate Editors...

  18. Mid-American Review of Sociology, Volume 15, Number 1 (WINTER, 1991): Front Matter

    E-print Network

    1991-01-01

    Hartman Wichita State University Faculty Sponsor William G. Staples Book Review Editor Brad Whorton Editor Mary E. Kelly Associate Editors Christopher Bohling Gary Foulke Andrea Anders William Swart Advisory Board William E. Thompson Emporia State... Department of Sociology "Department offering Ph.D. program I I I I I , I Human Ecology and Urban Revitalization: A Case Study of the Minneapolis Warehouse District Linda K. Roe RobertE. Rucker An Empirical Examination of Two Models of Cultural Causation Linda...

  19. The Winter 2010 and 2011 FRONT/NIRSS In-Flight Icing Hazard Detection Project

    NASA Technical Reports Server (NTRS)

    Serke, David; Hubbert, John; Reehorst, Andrew; Kennedy, Patrick; Politovich, Marcia

    2011-01-01

    The NASA Icing Remote Sensing System (NIRSS) deploys a vertically-pointing K-band radar, a lidar ceiliometer, and a profiling microwave radiometer to obtain measurements for diagnosing local inflight icing conditions. RAL is working with NASA GRC to develop algorithms and data ingest and display software for the system. NASA has an ongoing activity to develop remote sensing technologies for the detection and measurement of icing conditions aloft. As part of that effort NASA teamed with NCAR to develop software that fuses data from multiple instruments into a single detected icing condition product. The multiple instrument approach, which is the current emphasis of this activity, utilizes a K-band vertical staring radar, a microwave radiometer that detects twelve frequencies between 22 and 59 GHz, and a lidar ceilometer. The radar data determine cloud boundaries, the radiometer determines the sub-freezing temperature heights and total liquid water content, and the ceilometer refines the lower cloud boundary. Data is post-processed in C++ program with a Java-based web display of resultant supercooled LWC profile and aircraft hazard identification. In 2010, a multi-channel scanning radiometer, designed and built by Radiometrics, Inc. under a SBIR grant,,was added to the system to assess its utility in improving icing diagnoses.

  20. Auslegung: a journal of philosophy, Volume 26, Number 1 (Winter/Spring, 2004): Front Matter

    E-print Network

    Business Manager Robert Holliday, University of Kansas Associate Business Manager Tamela Ice, University of Kansas Systems Manager Cindi Hodges, University of Kansas Assistant Editors Richard Buck Peter P. Cvek David Detmer David A. Duquctt... Illinois State University Georgia Institute of Technology Loyola College Regis College Word Processing Gwen Claassen Secretarial Assistance Cindi Hodges Printing Assistance Linda Weeks Cover Design Tamela Ice The staff wishes to thank Christain Lötz...

  1. Mid-American Review of Sociology, Volume 17, Number 1 (WINTER, 1993): Front Matter

    E-print Network

    1993-01-01

    , Vol XVII, No.1: 1-15 This study seeks to examines the effects of race, gender, and interactive ethgender identies on attitudes concerning legal abortion and social tolerance of various. The data come from the combined 1972-1990 General Social Surveys... significant predictor ofsocialtolerance. No other social or moral issue, except perhaps the civil rights movement, has generated as much controversy as the abortion question. Since the 1973 SupremeCourt decision in Roe v. Wade, the abortion issue has produced...

  2. Mid-American Review of Sociology, Volume 3, Number 2 (WINTER, 1978): Front Matter

    E-print Network

    1978-01-01

    Vision: Alfred Schutz and the Myth of ofPhenomenological Social Science Robert Gonnan. Reviewed by David R. Dickens 127 129 131 WASHINGTON UNIVERSITY Department of Sociology" WICHITA STATE UNIVERSITY Department of Sociology UNIVERSITY OF WISCONSIN at LA...

  3. Condensation Front Migration in a Protoplanetary Nebula

    NASA Technical Reports Server (NTRS)

    Davis, Sanford S.

    2004-01-01

    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.

  4. Improving the Health Forecasting Alert System for Cold Weather and Heat-Waves In England: A Proof-of-Concept Using Temperature-Mortality Relationships

    PubMed Central

    Masato, Giacomo; Bone, Angie; Charlton-Perez, Andrew; Cavany, Sean; Neal, Robert; Dankers, Rutger; Dacre, Helen; Carmichael, Katie; Murray, Virginia

    2015-01-01

    Objectives In this study a prototype of a new health forecasting alert system is developed, which is aligned to the approach used in the Met Office’s (MO) National Severe Weather Warning Service (NSWWS). This is in order to improve information available to responders in the health and social care system by linking temperatures more directly to risks of mortality, and developing a system more coherent with other weather alerts. The prototype is compared to the current system in the Cold Weather and Heatwave plans via a case-study approach to verify its potential advantages and shortcomings. Method The prototype health forecasting alert system introduces an “impact vs likelihood matrix” for the health impacts of hot and cold temperatures which is similar to those used operationally for other weather hazards as part of the NSWWS. The impact axis of this matrix is based on existing epidemiological evidence, which shows an increasing relative risk of death at extremes of outdoor temperature beyond a threshold which can be identified epidemiologically. The likelihood axis is based on a probability measure associated with the temperature forecast. The new method is tested for two case studies (one during summer 2013, one during winter 2013), and compared to the performance of the current alert system. Conclusions The prototype shows some clear improvements over the current alert system. It allows for a much greater degree of flexibility, provides more detailed regional information about the health risks associated with periods of extreme temperatures, and is more coherent with other weather alerts which may make it easier for front line responders to use. It will require validation and engagement with stakeholders before it can be considered for use. PMID:26431427

  5. Effects of mild wintering conditions on body mass and corticosterone levels in a temperate reptile, the aspic viper (Vipera aspis).

    PubMed

    Brischoux, François; Dupoué, Andréaz; Lourdais, Olivier; Angelier, Frédéric

    2016-02-01

    Temperate ectotherms are expected to benefit from climate change (e.g., increased activity time), but the impacts of climate warming during the winter have mostly been overlooked. Milder winters are expected to decrease body condition upon emergence, and thus to affect crucial life-history traits, such as survival and reproduction. Mild winter temperature could also trigger a state of chronic physiological stress due to inadequate thermal conditions that preclude both dormancy and activity. We tested these hypotheses on a typical temperate ectothermic vertebrate, the aspic viper (Vipera aspis). We simulated different wintering conditions for three groups of aspic vipers (cold: ~6°C, mild: ~14°C and no wintering: ~24°C) during a one month long period. We found that mild wintering conditions induced a marked decrease in body condition, and provoked an alteration of some hormonal mechanisms involved in emergence. Such effects are likely to bear ultimate consequences on reproduction, and thus population persistence. We emphasize that future studies should incorporate the critical, albeit neglected, winter season when assessing the potential impacts of global changes on ectotherms. PMID:26626954

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

    USGS Publications Warehouse

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

    2009-01-01

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

  7. Pathophysiology of cold exposure.

    PubMed

    Wittmers, L E

    2001-11-01

    The change in core temperature that occurs as a result of exposure to cold air or water affects all body systems. A decrease in core temperature induces shivering, then muscle stiffness; depresses the central nervous and respiratory systems; triggers cardiac arrhythmias and vasoconstriction; and affects body [figure: see text] fluid balance. Cold water immersion presents additional considerations, including the general shock effect on the cardiac and respiratory systems and the triggering of the diving reflex when the entire body is immersed. Basic education and precautions can prevent most cases [figure: see text] of accidental hypothermia; but when they do occur, treatment should include controlled rewarming, especially if the core temperature is below 32 degrees C. PMID:11816961

  8. Radial cold trap

    DOEpatents

    Grundy, B.R.

    1981-09-29

    The radial cold trap comprises a housing having a plurality of mesh bands disposed therein. The mesh bands comprise concentrically arranged bands of mesh with the mesh specific surface area of each band increasing from the outermost mesh band to the innermost mesh band. An inlet nozzle is attached to the outside section of the housing while an outlet nozzle is attached to the inner portion of the housing so as to be concentrically connected to the innermost mesh band. An inlet baffle having orifices therein may be disposed around the outermost mesh band and within the housing for directing the flow of the fluid from the inlet nozzle to the outermost mesh band in a uniform manner. The flow of fluid passes through each consecutive mesh band and into the outlet nozzle. The circular pattern of the symmetrically arranged mesh packing allows for better utilization of the entire cold trap volume. 2 figs.

  9. Assessing the Geomorphic Evolution and Hydrographic Changes Induced by Winter Storms along the Louisiana Coast

    NASA Technical Reports Server (NTRS)

    Menzel, W. Paul; Moeller, Christopher, C; Huh, Oscar K.; Roberts, Harry H.

    1998-01-01

    The influence that cold front passages have on Louisiana coastal environments, including land loss and land building processes, has been the primary topic of this multidisciplinary research. This research has combined meteorological, remote sensing, and coastal expertise from the University of Wisconsin (UW) and Louisiana State University (LSU). Analyzed data sets include remotely sensed radiometric data (AVHRR on NOAA-12,13,14, Multispectral Atmospheric Mapping Sensor (MAMS) and MODIS Airborne Simulator (MAS) on NASA ER-2), U.S. Army Corps of Engineers (USACE) water level data, water quality data from the Coastal Studies Institute (CSI) at LSU, USACE river discharge data, National Weather Service (NWS) and CSI wind in sitzi measurements, geomorphic measurements from aerial photography (NASA ER-2 and Learjet), and CSI ground based sediment burial pipes (for monitoring topographic change along the Louisiana coast) and sediment cores. The work reported here-in is a continuation of an initial investigation into coastal Louisiana landform modification by cold front systems. That initial effort demonstrated the importance of cold front winds in the Atchafalaya Bay sediment plume distribution (Moeller et al.), documented the sediment transport and deposition process of the western Louisiana coast (Huh et al.) and developed tools (e.g. water types identification, suspended solids estimation) from multispectral radiometric data for application to the current study. This study has extended that work, developing a Geomorphic Impact Index (GI(sup 2)) for relating atmospheric forcing to coastal response and new tools to measure water motion and sediment transport.

  10. Cold nuclear fusion

    SciTech Connect

    Tsyganov, E. N.

    2012-02-15

    Recent accelerator experiments on fusion of various elements have clearly demonstrated that the effective cross-sections of these reactions depend on what material the target particle is placed in. In these experiments, there was a significant increase in the probability of interaction when target nuclei are imbedded in a conducting crystal or are a part of it. These experiments open a new perspective on the problem of so-called cold nuclear fusion.

  11. Clumpy cold dark matter

    NASA Technical Reports Server (NTRS)

    Silk, Joseph; Stebbins, Albert

    1993-01-01

    A study is conducted of cold dark matter (CDM) models in which clumpiness will inhere, using cosmic strings and textures suited to galaxy formation. CDM clumps of 10 million solar mass/cu pc density are generated at about z(eq) redshift, with a sizable fraction surviving. Observable implications encompass dark matter cores in globular clusters and in galactic nuclei. Results from terrestrial dark matter detection experiments may be affected by clumpiness in the Galactic halo.

  12. Light-Front Holographic QCD

    SciTech Connect

    Brodsky, Stanley J.; de Teramond, Guy F.; /Costa Rica U.

    2012-02-16

    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 leads in fact to a simple analytical and phenomenologically compelling nonperturbative approximation to the full light-front QCD Hamiltonian 'Light-Front Holography'. Light-Front Holography is in fact one of the most remarkable features of the AdS/CFT correspondence. The Hamiltonian equation of motion in the light-front (LF) is frame independent and has a structure similar to eigenmode equations in AdS space. This makes a direct connection of QCD with AdS/CFT methods possible. Remarkably, the AdS equations correspond to the kinetic energy terms of the partons inside a hadron, whereas the interaction terms build confinement and correspond to the truncation of AdS space in an effective dual gravity approximation. One can also study the gauge/gravity duality starting from the bound-state structure of hadrons in QCD quantized in the light-front. The LF Lorentz-invariant Hamiltonian equation for the relativistic bound-state system is P{sub {mu}}P{sup {mu}}|{psi}(P)> = (P{sup +}P{sup -} - P{sub {perpendicular}}{sup 2})|{psi}(P)> = M{sup 2}|{psi}(P)>, P{sup {+-}} = P{sup 0} {+-} P{sup 3}, where the LF time evolution operator P{sup -} is determined canonically from the QCD Lagrangian. To a first semiclassical approximation, where quantum loops and quark masses are not included, this leads to a LF Hamiltonian equation which describes the bound-state dynamics of light hadrons in terms of an invariant impact variable {zeta} which measures the separation of the partons within the hadron at equal light-front time {tau} = x{sup 0} + x{sup 3}. This allows us to identify the holographic variable z in AdS space with an impact variable {zeta}. The resulting Lorentz-invariant Schroedinger equation for general spin incorporates color confinement and is systematically improvable. Light-front holographic methods were originally introduced by matching the electromagnetic current matrix elements in AdS space with the corresponding expression using LF theory in physical space time. It was also shown that one obtains identical holographic mapping using the matrix elements of the energy-momentum tensor by perturbing the AdS metric around its static solution. A gravity dual to QCD is not known, but th

  13. Cold Stowage Flight Systems

    NASA Technical Reports Server (NTRS)

    Campana, Sharon

    2010-01-01

    The International Space Station (ISS) provides a test bed for researchers to perform science experiments in a variety of fields, including human research, life sciences, and space medicine. Many of the experiments being conducted today require science samples to be stored and transported in a temperature controlled environment. NASA provides several systems which aide researchers in preserving their science. On orbit systems provided by NASA include the Minus Eighty Laboratory freezer for ISS (MELFI), Microgravity Experiment Research Locker Incubator (MERLIN), and Glacier. These freezers use different technologies to provide rapid cooling and cold stowage at different temperature levels on board ISS. Systems available to researchers during transportation to and from ISS are MERLIN, Glacier, and Coldbag. Coldbag is a passive cold stowage system that uses phase change materials. Details of these current technologies will be provided along with operational experience gained to date. With shuttle retirement looming, NASA has protected the capability to provide a temperature controlled environment during transportation to and from the ISS with the use of Glacier and Coldbags, which are compatible with future commercial vehicles including SpaceX's Dragon Capsule, and Orbital s Cygnus vehicle. This paper will discuss the capability of the current cold stowage hardware and how it may continue to support NASA s mission on ISS and in future exploration missions.

  14. Cold Stowage Flight Systems

    NASA Technical Reports Server (NTRS)

    Campana, Sharon E.; Melendez, David T.

    2011-01-01

    The International Space Station (ISS) provides a test bed for researchers to perform science experiments in a variety of fields, including human research, life sciences, and space medicine. Many of the experiments being conducted today require science samples to be stored and transported in a temperature controlled environment. NASA provides several systems which aid researchers in preserving their science. On orbit systems provided by NASA include the Minus Eighty Laboratory freezer for ISS (MELFI), Microgravity Experiment Research Locker Incubator (MERLIN), and Glacier. These freezers use different technologies to provide rapid cooling and cold stowage at different temperature levels on board ISS. Systems available to researchers during transportation to and from ISS are MERLIN, Glacier, and Coldbag. Coldbag is a passive cold stowage system that uses phase change materials to maintain temperature. Details of these current technologies are provided along with operational experience gained to date. This paper discusses the capability of the current cold stowage hardware and how it may continue to support NASA s mission on ISS and in future exploration missions.

  15. The Structure and Dynamics of an Observed Moist Front

    NASA Technical Reports Server (NTRS)

    Orlanski, I.

    1985-01-01

    The structure and dynamics of the moist cold front of 25 and 26 April 1979, the third observing day of the Severe Environmental Storms and Mesoscale experiment (SESAME), are investigated through the use of a three-dimensional mesoscale numerical model. This work is one of the first studies in which model results are compared, in a one-to-one manner, with a detailed observational analysis, namely that of Ogura and Portis (1982) as taken from the SESAME observations. In addition, frontogenetical effects, both adiabatic and diabatic, are studied on a vertical cross-section through the front; similarities and differences with the adiabatic analysis of Ogura and Portis are discussed. Many similarities exist between the modeled and analyzed fields, although the analysis tends to have weaker horizontal gradients due to the coarseness of the observational network. Vorticity and convergence near the surface were found to have the same magnitude in both the model solution and the analysis, in contrast to idealized frontogenesis models which predict vorticity to be much larger than convergence.

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

    PubMed

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

    2015-09-15

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

  17. CHEMTAX-derived phytoplankton community structure associated with temperature fronts in the northeastern Arabian Sea

    NASA Astrophysics Data System (ADS)

    Roy, Rajdeep; Chitari, Rajath; Kulkarni, Vinayak; Krishna, M. S.; Sarma, V. V. S. S.; Anil, A. C.

    2015-04-01

    Remotely sensed sea surface temperature (SST) and chlorophyll associated with fronts and filaments are used in India to generate potential fishing zone (PFZ) advisories in the north eastern Arabian Sea (NEAS). However, biological response to this potential nutrient enhancement has not been investigated. Here we present phytoplankton pigment signatures and nutrient distribution from a section that sampled across a filament and front in the NEAS. We show that nutrient concentrations were high within the filament and front compared to the surrounding waters and had a unique phytoplankton assemblage. Even though there was difference in the physical properties between the filament and front, chemical taxonomy (CHEMTAX) showed dominance of similar phytoplankton groups (prymnesiophytes and prasinophytes). In contrast, Prochlorococcus sp. contributed more than 50% to the total phytoplankton biomass in the surrounding waters and below the oxycline. In general, prymnesiophytes were ubiquitous, covarying with high nutrients and cold temperature, and contributed 60-70% to the total phytoplankton biomass. This study demonstrates that phytoplankton groups respond strongly to nutrient enhancement that is often encountered within the vicinity of the SST fronts that characterize the PFZs.

  18. Winter Conditions Correlate with Phytophthora alni Subspecies Distribution in Southern Sweden.

    PubMed

    Redondo, Miguel A; Boberg, Johanna; Olsson, Christer H B; Oliva, Jonàs

    2015-09-01

    During the last century, the number of forest pathogen invasions has increased substantially. Environmental variables can play a crucial role in determining the establishment of invasive species. The objective of the present work was to determine the correlation between winter climatic conditions and distribution of two subspecies of the invasive forest pathogen Phytophthora alni: P. alni subspp. alni and uniformis killing black alder (Alnus glutinosa) in southern Sweden. It is known from laboratory experiments that P. alni subsp. alni is more pathogenic than P. alni subsp. uniformis, and that P. alni subsp. alni is sensitive to low temperatures and long frost periods. By studying the distribution of these two subspecies at the northern limit of the host species, we could investigate whether winter conditions can affect the geographical distribution of P. alni subsp. alni spreading northward. Sixteen major river systems of southern Sweden were systematically surveyed and isolations were performed from active cankers. The distribution of the two studied subspecies was highly correlated with winter temperature and duration of periods with heavy frost. While P. alni subsp. uniformis covered the whole range of temperatures of the host, P. alni subsp. alni was recovered in areas subjected to milder winter temperatures and shorter frost periods. Our observations suggest that winter conditions can play an important role in limiting P. alni subsp. alni establishment in cold locations, thus affecting the distribution of the different subspecies of P. alni in boreal regions. PMID:25822186

  19. Automatic detection of low altitude wind shear due to gust fronts in the terminal Doppler weather radar operational demonstration

    NASA Technical Reports Server (NTRS)

    Klingle-Wilson, Diana

    1990-01-01

    A gust front is the leading edge of the cold air outflow from a thunderstorm. Wind shears and turbulence along the gust front may produce potentially hazardous conditions for an aircraft on takeoff or landing such that runway operations are significantly impacted. The Federal Aviation Administration (FAA) has therefore determined that the detection of gust fronts in the terminal environment be an integral part of the Terminal Doppler Weather Radar (TDWR) system. Detection of these shears by the Gust Front Algorithm permits the generation of warnings that can be issued to pilots on approach and departure. In addition to the detection capability, the algorithm provides an estimate of the wind speed and direction following the gust front (termed wind shift) and the forecasted location of the gust front up to 20 minutes before it impacts terminal operations. This has shown utility as a runway management tool, alerting runway supervisors to approaching wind shifts and the possible need to change runway configurations. The formation and characteristics of gust fronts and their signatures in Doppler radar data are discussed. A brief description of the algorithm and its products for use by Air Traffic Control (ATC), along with an assessment of the algorithm's performance during the 1988 Operational Test and Evaluation, is presented.

  20. Front End G4beamline simulation update Front End G4beamline simulation update

    E-print Network

    McDonald, Kirk

    1 Front End G4beamline simulation update Front End G4beamline simulation update Pavel Snopok University of California Riverside September 14, 2010 #12;2 Front End G4beamline simulation update More statistics + comparison with ICOOL I show the results of comparison of G4beamline and ICOOL for: G4beamline

  1. Early wound reactions of Japanese maple during winter dormancy: the effect of two contrasting temperature regimes.

    PubMed

    Copini, Paul; den Ouden, Jan; Decuyper, Mathieu; Mohren, Godefridus M J; Loomans, Antoon J M; Sass-Klaassen, Ute

    2014-01-01

    During winter dormancy, temperate trees are capable of only a restricted response to wounding. Depending on the ambient temperature during winter dormancy, wounded trees may start compartmentalization, e.g. by producing inhibitory compounds, but it is thought that processes involving cell proliferation, such as the formation of callus and wound xylem, are delayed until the next growing season. We investigated the effect of two contrasting temperature regimes on early reactions of Acer palmatum trees to wounding during winter bud dormancy. Stems of A. palmatum trees were wounded and stored under an ambient temperature of 4 or 15 °C for 3 weeks during winter bud dormancy. We then studied wound reactions in the living bark, cambial region and xylem. In the 4 °C treatment, wound reactions were virtually absent. In the 15 °C treatment, however, trees reacted to wounding by dieback of the cortex and phloem and by the formation of ligno-suberized layers. In the cambial zone, cambial dieback occurred and callus tissue and wound xylem were formed locally, close to the wound margins. In the xylem, compartmentalization took place by deposition of inhibitory compounds in fibre cells and vessel elements. We conclude that temperature is an important factor in wound reactions during winter dormancy, and may even induce proliferation of callus and wound xylem within a 3-week period. It therefore seems likely that trees that have been wounded during dormancy in areas with mild or warm winters might cope better with wounding, as unlike trees in cold environments, they may compartmentalize wounds even during winter dormancy. PMID:25275087

  2. Winter and early spring CO2 efflux from tundra communities of northern Alaska

    USGS Publications Warehouse

    Fahnestock, J.T.; Jones, M.H.; Brooks, P.D.; Walker, D. A.; Welker, J.M.

    1998-01-01

    Carbon dioxide concentrations through snow were measured in different arctic tundra communities on the North Slope of Alaska during winter and early spring of 1996. Subnivean CO2 concentrations were always higher than atmospheric CO2. A steady state diffusion model was used to generate conservative estimates of CO2 flux to the atmosphere. The magnitude of CO2 efflux differed with tundra community type, and rates of carbon release increased from March to May. Winter CO2 efflux was highest in riparian and snow bed communities and lowest in dry heath, upland tussock, and wet sedge communities. Snow generally accrues earlier in winter and is deeper in riparian and snow bed communities compared with other tundra communities, which are typically windswept and do not accumulate much snow during the winter. These results support the hypothesis that early and deep snow accumulation may insulate microbial populations from very cold temperatures, allowing sites with earlier snow cover to sustain higher levels of activity throughout winter compared to communities that have later developing snow cover. Extrapolating our estimates of CO2 efflux to the entire snow-covered season indicates that total carbon flux during winter in the Arctic is 13-109 kg CO2-C ha-1, depending on the vegetation community type. Wintertime CO2 flux is a potentially important, yet largely overlooked, part of the annual carbon cycle of tundra, and carbon release during winter should be accounted for in estimates of annual carbon balance in arctic ecosystems. Copyright 1998 by the American Geophysical Union.

  3. Communicating Certainty About Nuclear Winter

    NASA Astrophysics Data System (ADS)

    Robock, A.

    2013-12-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  5. WINTER WHEAT VARIETIES Performance Evaluation and Recommendations

    E-print Network

    Dyer, Bill

    2012 WINTER WHEAT VARIETIES Performance Evaluation and Recommendations AND DISTRICTS and Hard White Winter Wheat Bearpaw ++2/ D D D Bynum (P) 2/ + D D Carter (P)+ D D D D D CDC Falcon (P)+ DI Rampart 2/ D D D WB-Quake (P)++ D D D D D D Yellowstone + D D D D D Soft White Winter Wheat Eltan D D Hill

  6. The light-front vacuum and dynamics

    E-print Network

    W. N. Polyzou

    2004-09-22

    I give a quantum theoretical description of kinematically invariant vacuua on the algebra of free fields restricted to a light front and discuss the relation between the light-front Hamiltonian, P-, the vacuum, and Poincare invariance. This provides a quantum theoretical description of zero modes.

  7. Effects of fluctuations on propagating fronts

    NASA Astrophysics Data System (ADS)

    Panja, Debabrata

    Propagating fronts are seen in varieties of nonequilibrium pattern forming systems in Physics, Chemistry and Biology. In the last two decades, many researchers have contributed to the understanding of the underlying dynamics of the propagating fronts. Of these, the deterministic and mean-field dynamics of the fronts were mostly understood in late 1980s and 1990s. On the other hand, although the earliest work on the effect of fluctuations on propagating fronts dates back to early 1980s, the subject of fluctuating fronts did not reach its adolescence until the mid 1990s. From there onwards the last few years witnessed a surge in activities in the effect of fluctuations on propagating fronts. Scores of papers have been written on this subject since then, contributing to a significant maturity of our understanding, and only recently a full picture of fluctuating fronts has started to emerge. This review is an attempt to collect all the works on fluctuating (propagating) fronts in a coherent and cogent manner in proper perspective. It is based on the idea of making our knowledge in this field available to a broader audience, and it is also expected to help to collect bits and pieces of loose thread-ends together for possible further investigation.

  8. Nuclear Physics on the Light Front

    E-print Network

    Gerald A. Miller

    1999-08-06

    High energy scattering experiments involving nuclei are typically analyzed in terms of light front variables. The desire to provide realistic, relativistic wave functions expressed in terms of these variables led me to try to use light front dynamics to compute nuclear wave functions. The progress is summarized here.

  9. To the non-local theory of cold nuclear fusion.

    PubMed

    Alexeev, Boris V

    2014-10-01

    In this paper, we revisit the cold fusion (CF) phenomenon using the generalized Bolzmann kinetics theory which can represent the non-local physics of this CF phenomenon. This approach can identify the conditions when the CF can take place as the soliton creation under the influence of the intensive sound waves. The vast mathematical modelling leads to affirmation that all parts of soliton move with the same velocity and with the small internal change of the pressure. The zone of the high density is shaped on the soliton's front. It means that the regime of the 'acoustic CF' could be realized from the position of the non-local hydrodynamics. PMID:26064528

  10. To the non-local theory of cold nuclear fusion

    PubMed Central

    Alexeev, Boris V.

    2014-01-01

    In this paper, we revisit the cold fusion (CF) phenomenon using the generalized Bolzmann kinetics theory which can represent the non-local physics of this CF phenomenon. This approach can identify the conditions when the CF can take place as the soliton creation under the influence of the intensive sound waves. The vast mathematical modelling leads to affirmation that all parts of soliton move with the same velocity and with the small internal change of the pressure. The zone of the high density is shaped on the soliton's front. It means that the regime of the ‘acoustic CF’ could be realized from the position of the non-local hydrodynamics. PMID:26064528

  11. Rev. 6/15 Summer & Winter Programs | UNIVERSITY OF CONNECTICUT Office of Summer & Winter Programs

    E-print Network

    Lozano-Robledo, Alvaro

    Rev. 6/15 Summer & Winter Programs | UNIVERSITY OF CONNECTICUT Office of Summer & Winter Programs and the word "appeal" with any documentation that arrives separately. Choose Campus Select Year #12;Rev. 6

  12. Winter warming from large volcanic eruptions

    SciTech Connect

    Robock, A.; Mao, J.

    1992-01-01

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

  13. A Preliminary Study of Surface Temperature Cold Bias in COAMPS

    SciTech Connect

    Chin, H-N S; Leach, M J; Sugiyama, G A; Aluzzi, F J

    2001-04-27

    It is well recognized that the model predictability is more or less hampered by the imperfect representations of atmospheric state and model physics. Therefore, it is a common problem for any numerical models to exhibit some sorts of biases in the prediction. In this study, the emphasis is focused on the cold bias of surface temperature forecast in Naval Research Laboratory's three-dimensional mesoscale model, COAMPS (Coupled Ocean/Atmosphere Mesoscale Prediction System). Based on the comparison with the ground station data, there were two types of ground temperature cold biases identified in LLNL (Lawrence Livermore National Laboratory) operational forecasts of COAMPS over the California and Nevada regions during the 1999 winter and the 2000 spring. The first type of cold bias appears at high elevation regions covered by snow, and its magnitude can be as large as 30 F - 40 F lower than observed. The second type of cold bias mainly exists in the snow-free clear-sky regions, where the surface temperature is above the freezing point, and its magnitude can be up to 5 F - 10 F lower than observed. These cold biases can affect the low-level stratification, and even the diurnal variation of winds in the mountain regions, and therefore impact the atmospheric dispersion forecast. The main objective of this study is to explore the causes of such cold bias, and to further the improvement of the forecast performance in COAMPS. A series of experiments are performed to gauge the sensitivity of the model forecast due to the physics changes and large-scale data with various horizontal and vertical resolutions.

  14. Processes Controlling Water Vapor in the Winter Arctic Tropopause Region

    NASA Technical Reports Server (NTRS)

    Pfister, Leonhard; Selkirk, Henry B.; Jensen, Eric J.; Podolske, James; Sachse, Glen; Avery, Melody; Schoeberl, Mark R.; Hipskino, R. Stephen (Technical Monitor)

    2001-01-01

    This work describes transport and thermodynamic processes that control water vapor near the tropopause during the SAGE Ozone Loss and Validation Experiment (SOLVE), held during the Arctic 1999-2000 winter season. Aircraft based water vapor, carbon monoxide, and ozone measurements are analyzed so as to establish how deeply tropospheric air mixes into the arctic lower-most stratosphere, and what the implications are for cloud formation and water vapor removal in this region of the atmosphere. There are three major findings. First, troposphere-to- stratosphere exchange extends into the arctic stratosphere to about 13 km. Penetration is to similar levels throughout the winter, however, because ozone increases idly in the early spring, tropospheric air mixes with the highest values of ozone in that season. The effect of this upward mixing is to elevate water vapor mixing ratios significantly above their prevailing stratospheric values of about 5 ppmv. Second, the potential for cloud formation in the stratosphere is highest during early spring, with about 20\\% of the parcels which have ozone values of 300-350ppbv experiencing ice saturation in a given 10 day period. Third, during early Spring temperatures at the tropopause are cold enough so that 5-10\\% of parcels experience relative humidities above 100\\%, even if the water content is as low as 5 ppmv. The implication is that during, this period the arctic tropopause can play an important role in maintaining a very dry upper troposphere during early Spring.

  15. Processes Controlling Water Vapor in the Winter Arctic Tropopause Region

    NASA Technical Reports Server (NTRS)

    Pfister, Leonhard; Selkirk, Henry B.; Jensen, Eric J.; Padolske, James; Sachse, Glen; Avery, Melody; Schoeberl, Mark R.; Mahoney, Michael J.; Richard, Erik

    2002-01-01

    This work describes transport and thermodynamic processes that control water vapor near the tropopause during the SAGE III-Ozone Loss and Validation Experiment (SOLVE), held during the Arctic 1999/2000 winter season. Aircraft-based water vapor, carbon monoxide, and ozone measurements were analyzed so as to establish how deeply tropospheric air mixes into the Arctic lowermost stratosphere and what the implications are for cloud formation and water vapor removal in this region of the atmosphere. There are three major findings. First, troposphere-to-stratosphere exchange extends into the Arctic stratosphere to about 13 km. Penetration is to similar levels throughout the winter, however, because ozone increases with altitude most rapidly in the early spring, tropospheric air mixes with the highest values of ozone in that season. The effect of this upward mixing is to elevate water vapor mixing ratios significantly above their prevailing stratospheric values of above 5ppmv. Second, the potential for cloud formation in the stratosphere is highest during early spring, with about 20% of the parcels which have ozone values of 300-350 ppbv experiencing ice saturation in a given 10 day period. Third, during early spring, temperatures at the troposphere are cold enough so that 5-10% of parcels experience relative humidities above 100%, even if the water content is as low as 5 ppmv. The implication is that during this period, dynamical processes near the Arctic tropopause can dehydrate air and keep the Arctic tropopause region very dry during early spring.

  16. Winter Eurasian Climate Variability: Role of Cyclone and Anticyclone Activity

    NASA Astrophysics Data System (ADS)

    Lu, C.; Zhang, X.; Guan, Z.

    2012-12-01

    This study investigates variability of extratropical Eurasian cyclone and anticyclone activity by using a modified automated cyclone and anticyclone identification and tracking algorithm. The cyclone and anticyclone activities are quantified by their regionally integrated intensity (CI and ACI) during 1978/79-2011/2012 winter seasons. We found that the time evolutions of the CI and ACI exhibit a general negative correlation of -0.7 between them at a significant level of 99.99%. This anticyclone (cyclone) variability contributes to the substantially large-scale sea level pressure variability over extratropical Eurasian continent, and explains the interannual fluctuation of surface air temperature over mid latitude Eurasia as well as the adjacent continents. The ACI swings from one phase to another, also producing large changes in snow cover extend, snow equivalent water as well as frequency of extreme cold events over the Eurasian continent. The strengthening of anticyclone intensity is preceded by retreated of the October sea-ice extent over Barents-Kara Sea, which associates tightly with an increasing stability at lower troposphere around the Ural Mountains and induces strengthening Eurasian anticyclones activity in the subsequent winter.

  17. Cold hardiness of southern-adapted blueberry genotypes and the potential for their use in northern adapted blueberry breeding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Twelve southern-adapted blueberry genotypes, both southern highbush and rabbiteye, were evaluated for mid-winter cold hardiness using a shoot freezing assay. Significant differences in LT50 values were observed among the genotypes, ranging from -11.9 °C for ‘Millennia’, a southern highbush cultivar,...

  18. EST ANALYSIS FOR THE STUDY OF COLD HARDINESS AND DEVELOPMENT OF EST-PCR MARKERS IN BLUEBERRY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although the United States is the world's leading blueberry (Vaccinium spp.) producer, it lacks sufficient number of winter hardy and spring frost resistant cultivars. Our laboratory has been studying genetic and molecular aspects of cold hardiness in blueberry in order to identify markers/genes as...

  19. Cold weather operating guidelines and experience for natural draft cooling towers on the American Electric Power system

    SciTech Connect

    Michell, F.L.; Drew, D.H.

    1996-10-01

    American Electric Power`s more than 30 years of experience in operating natural draft cooling towers during freezing winter weather conditions is discussed in the paper. Design features incorporated into the specifications for major rebuild/repack projects for crossflow and counterflow towers to facilitate cold weather operation are also reviewed.

  20. QUANTITATIVE TRAIT LOCI FOR WINTER HARDINESS COMPONENT TRAITS IN OAT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Winter hardiness is an important limitation to winter oat (Avena byzantina and A. sativa) production in much of North America, but field evaluation of winter hardiness is difficult. The discovery of quantitative trait loci for winter hardiness should allow markers assisted selection for winter hard...

  1. The Relation of El Nino Southern Oscillation to Winter Tornado Outbreaks

    NASA Astrophysics Data System (ADS)

    Robinson Cook, A. D.; Schaefer, J. T.

    2007-12-01

    Winter tornado activity (January, February, and March) between 1950 and 2003 was analyzed to determine the possible effect of seasonally averaged sea surface temperatures in the equatorial Pacific Ocean, the ENSO phase, on the location and strength of tornado outbreaks in the United States. Tornado activity was gauged through analyses of tornadoes occurring on tornado days (a calendar day featuring 6 or more tornadoes within the contiguous United States) and strong and violent tornado days (a calendar day featuring 5 or more tornadoes rated F-2 and greater within the contiguous United States). The tornado days were then stratified according to warm (37 tornado days, 14 violent days), cold (51 tornado days, 28 violent days), and neutral (74 tornado days, 44 violent days) winter ENSO phase. It is seen that during winter periods of neutral tropical Pacific sea surface temperatures, there is a tendency for United States tornado outbreaks to be stronger and more frequent than they are during winter periods of anomalously warm tropical Pacific sea surface temperatures (El Nino). During winter periods with anomalously cool Pacific sea surface temperatures (La Nina), the frequency and strength of United States tornado activity lies between that of the neutral and El Nino phase. ENSO related shifts in the preferred location of tornado activity are also observed. Historically, during the neutral phase, tornado outbreaks typically occurred from central Oklahoma and Kansas eastward through the Carolinas. During cold phases, tornado outbreaks have typically occurred in a zone stretching from southeastern Texas northeastward into Illinois, Indiana, and Michigan. During anomalously warm phases activity was mainly limited to the Gulf Coast States including central Florida. The data are statistically and synoptically analyzed to show that they are not only statistically significant, but also meteorologically reasonable.

  2. Plausible influence of Atlantic Ocean SST anomalies on winter haze in China

    NASA Astrophysics Data System (ADS)

    Xiao, Dong; Li, Ying; Fan, Shaojia; Zhang, Renhe; Sun, Jiaren; Wang, Yan

    2015-10-01

    The possible influence of Atlantic sea surface temperature (SST) on winter haze days in China at interannual and decadal time scales is investigated using the observed haze-day data from 329 meteorological stations, National Centers for Environmental Prediction-National Centers for Atmospheric Research (NCEP-NCAR) reanalysis, and a SST dataset for 1978-2012. Wintertime haze days in China show robust interannual variations and significant increases over time. The SST anomalies over the North Atlantic from summer to the following winter exhibit a significant in-phase relationship with winter haze days on both decadal and interannual time scales, whereas the anomalous negative-positive SSTs from north to south over the South Atlantic from autumn to the following winter show a significant positive relationship with winter haze days on the interannual time scale. The anomalous warm SST over the North Atlantic, i.e., the positive phase of the Atlantic multidecadal oscillation (AMO), corresponds to the positive phase of the Arctic oscillation (AO). This result implies that a stable mean flow and strong westerly anomalies exist over north China. The anomalous dipole pattern in the South Atlantic results in the abnormal southerly airflow in the troposphere over eastern China. Neither the westerly anomalies over north China nor the southerly anomalies over eastern China, which are associated with the North Atlantic and South Atlantic SST anomalies, respectively, are conducive to occurrences of cold air. Consequently, the weakened cold airflow from north of eastern China suppresses the dispersion of pollutants over China and results in above-normal haze days.

  3. Living Bulimina marginata in the SW Atlantic continental margin: Effect of the Subtropical Shelf Front and South Atlantic Central Water

    NASA Astrophysics Data System (ADS)

    Eichler, Patrícia P. B.; Pimenta, Felipe M.; Eichler, Beatriz B.; Vital, Helenice

    2014-10-01

    The western South Atlantic continental margin, between 27° and 37°S, is dominated by three main water masses: cold-fresh Subantarctic Shelf Water (SASW), warm-salty Subtropical Shelf Water (STSW) and Plata Plume Water (PPW). Despite the large seasonal variability of PPW extension along the shelf, an intense and relatively stable temperature-salinity gradient separates the SASW and the STSW forming the Subtropical Shelf Front (STSF) around 32°S. This article demonstrates that the distribution of Bulimina marginata, (shelf environment and deep-sea) a species of benthic foraminifera is influenced by the front location and it can be used as a proxy of the STSF in sediment core analysis.

  4. The Isis cold moderators

    SciTech Connect

    Allen, G. M.; Broome, T. A.; Burridge, R. A.; Cragg, D.; Hall, R.; Haynes, D.; Hirst, J.; Hogston, J. R.; Jones, H. H.; Sexton, J.; Wright, P.

    1997-09-01

    ISIS is a pulsed spallation neutron source where neutrons are produced by the interaction of a 160 kW proton beam of energy 800 MeV in a water-cooled Tantalum Target. The fast neutrons produced are thermalized in four moderators: two ambient water, one liquid methane operating at 100K and a liquid hydrogen moderator at 20 K. This paper gives a description of the construction of both cold moderator systems, details of the operating experience and a description of the current development program.

  5. 33 CFR 100.109 - Winter Harbor Lobster Boat Race, Winter Harbor, ME.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Winter Harbor Lobster Boat Race, Winter Harbor, ME. 100.109 Section 100.109 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... Lobster Boat Race, Winter Harbor, ME. (a) Regulated area. The regulated area includes all waters of...

  6. Xanthophyll cycle pigment and antioxidant profiles of winter-red (anthocyanic) and winter-green (acyanic) angiosperm evergreen species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Leaves of many angiosperm evergreen species turn red during winter, corresponding with synthesis of anthocyanin pigments. The function of winter color change, and why it occurs in some species and not others, is not yet understood. We hypothesized that anthocyanins play a compensatory photoprotect...

  7. The Remarkable 2003--2004 Winter and Other Recent Warm Winters in the Arctic Stratosphere Since the Late 1990s

    NASA Technical Reports Server (NTRS)

    Manney, Gloria L.; Kruger, Kirstin; Sabutis, Joseph L.; Sena, Sara Amina; Pawson, Steven

    2005-01-01

    The 2003-2004 Arctic winter was remarkable in the approximately 50-year record of meteorological analyses. A major warming beginning in early January 2004 led to nearly 2 months of vortex disruption with high-latitude easterlies in the middle to lower stratosphere. The upper stratospheric vortex broke up in late December, but began to recover by early January, and in February and March was the strongest since regular observations began in 1979. The lower stratospheric vortex broke up in late January. Comparison with 2 previous years, 1984-1985 and 1986-1987, with prolonged midwinter warming periods shows unique characteristics of the 2003-2004 warming period: The length of the vortex disruption, the strong and rapid recovery in the upper stratosphere, and the slow progression of the warming from upper to lower stratosphere. January 2004 zonal mean winds in the middle and lower stratosphere were over 2 standard deviations below average. Examination of past variability shows that the recent frequency of major stratospheric warmings (7 in the past 6 years) is unprecedented. Lower stratospheric temperatures were unusually high during 6 of the past 7 years, with 5 having much lower than usual potential for polar stratospheric cloud (PSC) formation and ozone loss (nearly none in 1998-1999, 2001-2002, and 2003-2004, and very little in 1997-1998 and 2000-2001). Middle and upper stratospheric temperatures, however, were unusually low during and after February. The pattern of 5 of the last 7 years with very low PSC potential would be expected to occur randomly once every 850 years. This cluster of warm winters, immediately following a period of unusually cold winters, may have important implications for possible changes in interannual variability and for determination and attribution of trends in stratospheric temperatures and ozone.

  8. Winter Driving Tips Driving in Ice & Snow

    E-print Network

    Capogna, Luca

    time the vehicle is in gear, touch the gas lightly until the vehicle gets moving. If you have a front-wheel faster than everyone else. In a rear-wheel drive vehicle, you can usually feel a loss of traction or the beginning of a skid. There may be no such warning in a front-wheel drive, however. Front-wheel drives do

  9. Cold Lithium Atom Interferometer

    NASA Astrophysics Data System (ADS)

    Cassella, Kayleigh; Copenhaver, Eric; Lai, Chen; Hamilton, Paul; Estey, Brian; Feng, Yanying; Mueller, Holger

    2015-05-01

    Atom interferometers often use heavy alkali atoms such as rubidium or cesium. In contrast, interferometry with light atoms offers a larger recoil velocity and recoil energy, yielding a larger interference signal. This would allow for sensitive measurements of the fine structure constant, gravity gradients and spatially varying potentials. We have built the first light-pulse cold-atom interferometer with lithium in a Mach-Zehnder geometry based on short (100 ns), intense (2.5 W/cm2) pulses. We initially capture approximately 107 lithium atoms at a temperature of about 300 ?K in a magneto-optical trap. To perform interferometry, we couple the F = 1 and F = 2 hyperfine levels of the ground state with a sequence of two-photon Raman transitions, red-detuned from lithium's unresolved 2P3/2 state. Cold lithium atoms offer a broad range of new possibilities for atom interferometry including a large recoil velocity and a fermionic and bosonic isotope. Lithium's isotopes also allow for independent measurements of gravity thus constraining the equivalence principle violations predicted by the Standard-Model Extension. In the near future, we plan to perform a recoil measurement using a Ramsey-Bordé interferometer.

  10. Middle Atlantic Bight cold pool: Evolution of the temperature structure during summer 1979

    SciTech Connect

    Houghton, R.W.; Schlitz, R.; Beardsley, R.C.; Butman, B.; Chamberlin, J.L.

    1982-10-01

    Temperature data spanning the entire Middle Atlantic Bight (MAB) during 1979 are used to study the structure and evolution of the cold pool. The Nantucket Shoals and New England Shelf appear to be the souce of the coldest water found in the MAB in late winter. During the spring and summer, water within the cold pool in the New York Bight north of Hudson Canyon remains colder than any shelf water either to the northeast or southwest. Thus the coldest cold-pool water persists there as a remnant of winter-cooled water rather than being replenished by a colder upstream source, and south of Hudson Canyon, cold-pool temperatures decrease in June and July as colder water from upstream is advected southwestward along the coast. Both temperature data and direct current measurements suggest that the mean alongshore current has a minimum between Nantucket Shoals and Hudson Canyon. The alongshore variation of shelf topography appears to be responsible for the spatial variation in both the alongshelf drift speed and the thermal structure of the cold pool.

  11. Cyclone and Anticyclone Activities Impact Eurasian Surface Climate and Cause Extreme Cold Events ?

    NASA Astrophysics Data System (ADS)

    Lu, C.; Zhang, X.; Guan, Z.; Wang, Z.; Qin, Y.

    2014-12-01

    Extreme cold winter weather events have more frequently occurred during recent decades over the Eurasian continent, in conjunction with the rapidly warming Arctic. Although various contributing factors have been examined, including changes in the atmospheric circulation, increase in meridional span of jet stream fluctuation, and anomalous snow and sea ice forcing, it still remains unclear how internally or externally altered large-scale atmospheric dynamics has driven daily-based extreme cold events. In this study, we further investigated variability of and changes in extratropical storm tracks and anticyclones and their resultant dynamic and thermodynamic role in causing extreme cold weathers over Eurasia. The major approach employed is a modified automated cyclone and anticyclone identification and tracking algorithm. Our results reinforced our previous finding that storms have weakened and anticyclones have intensified over Eurasia during 1978/79-2011/2012 winter seasons. Corresponding to these long-term changes, anomalous high pressure occurred over the Ural area, providing fundamental dynamic setting favoring occurrence of blocking events. As a consequence, polar cold air was advected southward to the midlatitude, causing extreme cold events. Along with this dynamic process, snow cover also extended southward to reduce surface absorption of downwelling shortwave radiation and further the cooling process. Barents-Kara sea ice forcing was examined to identify underlying physical mechanisms for changes in storm tracks and anticyclone activities.

  12. Idiopathic cold urticaria and anaphylaxis.

    PubMed

    I?k, Sakine; Arkan-Ayyldz, Zeynep; Sozmen, Sule Caglayan; Karaman, Özkan; Uzuner, Nevin

    2014-01-01

    Cold urticaria (CU) is a subtype of physical urticaria characterized by the development of urticaria and angioedema after cold exposure. Symptoms typically occur minutes after skin exposure to cold air, liquids, and objects. Most common method to confirm the diagnosis of CU is through ice cube challenge test, but 20% of patients with CU have negative ice cube challenge test results. The greatest risk with this kind of urticaria is the development of systemic reaction resulting in a hemodynamic collapse during generalized cold exposure. We report a case of a patient who developed CU and anaphylaxis during swimming and diving in the sea. PMID:24378859

  13. Southern elephant seal trajectories, fronts and eddies in the Brazil/Malvinas Confluence

    NASA Astrophysics Data System (ADS)

    Campagna, Claudio; Piola, Alberto R.; Rosa Marin, Maria; Lewis, Mirtha; Fernández, Teresita

    2006-12-01

    This study describes the association between transient, mesoscale hydrographic features along the axis of the Brazil-Malvinas Confluence, in the SW Atlantic, and the foraging behavior of 2-3-year-old (focal) juvenile southern elephant seals, Mirounga leonina, from Península Valdés, Argentina. Departing from the dominant pattern of foraging on predictable bathymetric fronts on the Patagonian shelf and slope, three females out of 12 satellite-tracked juveniles remained at the edge of young warm-core eddies and near the outer core of cold-core eddies, coinciding with the most productive areas of these temperature fronts. Seal trajectories along high-temperature gradients were always consistent with the speed and direction of surface currents inferred from the temperature distribution and confirmed by surface drifters. Movements of foraging seals were compared with those of surface drifters, coinciding in time and space and yielding independent and consistent data on regional water circulation parameters. The diving pattern recorded for one focal seal yielded shallower dives and a loose diel pattern in the eddy, and a marked diurnal cycle compatible with foraging on vertically migrating prey in the cold waters of the Malvinas Current. Pre-reproductive females that use the mesoscale fronts of the Argentine Basin as an alternative foraging area would benefit from lower competition with more experienced seals and with other top predators that reproduce along the coast of Patagonia.

  14. Stability of cosmological deflagration fronts

    NASA Astrophysics Data System (ADS)

    Mégevand, Ariel; Membiela, Federico Agustín

    2014-05-01

    In a cosmological first-order phase transition, bubbles of the stable phase nucleate and expand in the supercooled metastable phase. In many cases, the growth of bubbles reaches a stationary state, with bubble walls propagating as detonations or deflagrations. However, these hydrodynamical solutions may be unstable under corrugation of the interface. Such instability may drastically alter some of the cosmological consequences of the phase transition. Here, we study the hydrodynamical stability of deflagration fronts. We improve upon previous studies by making a more careful and detailed analysis. In particular, we take into account the fact that the equation of motion for the phase interface depends separately on the temperature and fluid velocity on each side of the wall. Fluid variables on each side of the wall are similar for weakly first-order phase transitions, but differ significantly for stronger phase transitions. As a consequence, we find that, for large enough supercooling, any subsonic wall velocity becomes unstable. Moreover, as the velocity approaches the speed of sound, perturbations become unstable on all wavelengths. For smaller supercooling and small wall velocities, our results agree with those of previous works. Essentially, perturbations on large wavelengths are unstable, unless the wall velocity is higher than a critical value. We also find a previously unobserved range of marginally unstable wavelengths. We analyze the dynamical relevance of the instabilities, and we estimate the characteristic time and length scales associated with their growth. We discuss the implications for the electroweak phase transition and its cosmological consequences.

  15. Stability of cosmological detonation fronts

    NASA Astrophysics Data System (ADS)

    Mégevand, Ariel; Membiela, Federico Agustín

    2014-05-01

    The steady-state propagation of a phase-transition front is classified, according to hydrodynamics, as a deflagration or a detonation, depending on its velocity with respect to the fluid. These propagation modes are further divided into three types, namely, weak, Jouguet, and strong solutions, according to their disturbance of the fluid. However, some of these hydrodynamic modes will not be realized in a phase transition. One particular cause is the presence of instabilities. In this work we study the linear stability of weak detonations, which are generally believed to be stable. After discussing in detail the weak detonation solution, we consider small perturbations of the interface and the fluid configuration. When the balance between the driving and friction forces is taken into account, it turns out that there are actually two different kinds of weak detonations, which behave very differently as functions of the parameters. We show that the branch of stronger weak detonations are unstable, except very close to the Jouguet point, where our approach breaks down.

  16. Front end for GPS receivers

    NASA Technical Reports Server (NTRS)

    Thomas, Jr., Jess Brooks (Inventor)

    1999-01-01

    The front end in GPS receivers has the functions of amplifying, down-converting, filtering and sampling the received signals. In the preferred embodiment, only two operations, A/D conversion and a sum, bring the signal from RF to filtered quadrature baseband samples. After amplification and filtering at RF, the L1 and L2 signals are each sampled at RF at a high selected subharmonic rate. The subharmonic sample rates are approximately 900 MHz for L1 and 982 MHz for L2. With the selected subharmonic sampling, the A/D conversion effectively down-converts the signal from RF to quadrature components at baseband. The resulting sample streams for L1 and L2 are each reduced to a lower rate with a digital filter, which becomes a straight sum in the simplest embodiment. The frequency subsystem can be very simple, only requiring the generation of a single reference frequency (e.g. 20.46 MHz minus a small offset) and the simple multiplication of this reference up to the subharmonic sample rates for L1 and L2. The small offset in the reference frequency serves the dual purpose of providing an advantageous offset in the down-converted carrier frequency and in the final baseband sample rate.

  17. Animals in Winter. Young Discovery Library Series.

    ERIC Educational Resources Information Center

    de Sairigne, Catherine

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

  18. A SIMPLE WINTER PROTECTION SYSTEM FOR BLACKBERRIES

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  19. A SIMPLE WINTER PROTECTION SYSTEM FOR BLACKBERRIES

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  20. 36 CFR 2.19 - Winter activities.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Winter activities. 2.19 Section 2.19 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR RESOURCE PROTECTION, PUBLIC USE AND RECREATION § 2.19 Winter activities. (a) Skiing, snowshoeing,...

  1. 36 CFR 1002.19 - Winter activities.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Winter activities. 1002.19 Section 1002.19 Parks, Forests, and Public Property PRESIDIO TRUST RESOURCE PROTECTION, PUBLIC USE AND RECREATION § 1002.19 Winter activities. (a) Skiing, snowshoeing, ice skating, sledding,...

  2. Deeper Snow Enhances Winter Respiration from Both

    E-print Network

    Grogan, Paul

    in Birch Hummock Tundra Sonia Nobrega, and Paul Grogan* Department of Biology, Queen`s University, Kingston on winter carbon dioxide fluxes from mesic birch hummock tundra in northern Canada. We differ- entiated release to the atmosphere. Key words: climate change; winter; snow; soil; tundra; birch; arctic

  3. Winter cover biomass production and soil penetrability

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  4. Nuclear Winter: Scientists in the Political Arena

    NASA Astrophysics Data System (ADS)

    Badash, Lawrence

    2001-03-01

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

  5. Social Media Plan #WinterPrep

    E-print Network

    are common during the winter and spring along rivers, streams and creeks in the northern U.S. and Alaska Jams Nor'easter Windchill Temperature Polar Vortex Blizzards Watch vs Warning Tsunami, streams and creeks can cause dangerous flooding. http://www.floodsafety.noaa.gov/hazards.shtml #Winter

  6. Paul Conal Winters Department of Economics, American University

    E-print Network

    Carlini, David

    Winters. "Explaining Gender Differentials in Agricultural Production in Nigeria." To be published in Agricultural Economics. Karamba, R. Wendy and Paul Winters. "Gender and Agricultural Productivity: Implications, Benjamin Davis and Paul Winters. (2013) "Cash transfer programs and agricultural production: The Case

  7. A Study of School Without Schools: The Columbus, Ohio Public Schools During the Natural Gas Shortage, Winter, 1977. Volume I and Volume II, Appendices.

    ERIC Educational Resources Information Center

    Sanders, James R.; Stufflebeam, Daniel L.

    The energy crisis, specifically a shortage of natural gas, caused by the unusually cold winter of 1977, resulted in the Columbus, Ohio, schools being closed for a month. Schools heated with gas were closed, but students met one day a week in school buildings that used coal, oil, or electricity. The educational program continued with school…

  8. What Is a Mild Winter? Regional Differences in Within-Species Responses to Climate Change.

    PubMed

    Vetter, Sebastian G; Ruf, Thomas; Bieber, Claudia; Arnold, Walter

    2015-01-01

    Climate change is known to affect ecosystems globally, but our knowledge of its impact on large and widespread mammals, and possibly population-specific responses is still sparse. We investigated large-scale and long-term effects of climate change on local population dynamics using the wild boar (Sus scrofa L.) as a model species. Our results show that population increases across Europe are strongly associated with increasingly mild winters, yet with region-specific threshold temperatures for the onset of exponential growth. Additionally, we found that abundant availability of critical food resources, e.g. beech nuts, can outweigh the negative effects of cold winters on population growth of wild boar. Availability of beech nuts is highly variable and highest in years of beech mast which increased in frequency since 1980, according to our data. We conclude that climate change drives population growth of wild boar directly by relaxing the negative effect of cold winters on survival and reproduction, and indirectly by increasing food availability. However, region-specific responses need to be considered in order to fully understand a species' demographic response to climate change. PMID:26158846

  9. What Is a Mild Winter? Regional Differences in Within-Species Responses to Climate Change

    PubMed Central

    Vetter, Sebastian G.; Ruf, Thomas; Bieber, Claudia; Arnold, Walter

    2015-01-01

    Climate change is known to affect ecosystems globally, but our knowledge of its impact on large and widespread mammals, and possibly population-specific responses is still sparse. We investigated large-scale and long-term effects of climate change on local population dynamics using the wild boar (Sus scrofa L.) as a model species. Our results show that population increases across Europe are strongly associated with increasingly mild winters, yet with region-specific threshold temperatures for the onset of exponential growth. Additionally, we found that abundant availability of critical food resources, e.g. beech nuts, can outweigh the negative effects of cold winters on population growth of wild boar. Availability of beech nuts is highly variable and highest in years of beech mast which increased in frequency since 1980, according to our data. We conclude that climate change drives population growth of wild boar directly by relaxing the negative effect of cold winters on survival and reproduction, and indirectly by increasing food availability. However, region-specific responses need to be considered in order to fully understand a species’ demographic response to climate change. PMID:26158846

  10. Short winters threaten temperate fish populations.

    PubMed

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

    2015-01-01

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

  11. Short winters threaten temperate fish populations

    NASA Astrophysics Data System (ADS)

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

    2015-07-01

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

  12. Short winters threaten temperate fish populations

    PubMed Central

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

    2015-01-01

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

  13. Dusty Gust Fronts at Synoptic Scale, Initiated and Maintained by Moist Convection over the Sahara Desert

    NASA Astrophysics Data System (ADS)

    Bou Karam, D.; Williams, E.; McGraw-Herdeg, M.; Janiga, M.; Cuesta, J.; Flamant, C.; Pelon, J.; Thorncroft, C.

    2009-12-01

    So-called ‘dry’ microburst outflows are well known phenomena in desert environments when rain from moist convection aloft evaporates into deep, dry-adiabatic boundary layers. Extreme synoptic scale versions of this convective scale phenomenon have been documented in this study, in which the collective episodes of convective downdraft feed a common cold pool that expands as a gust front density current, raising large amount of dust in the boundary layer, and initiating new moist convection over the Sahara. Satellite observations from the Spinning Enhanced Visible and Infra-Red Imager (SEVIRI) and the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) combined with selected West African surface station observations have been integrated to study the gust front and its associated dust activity in the period of August 3-6, 2006. The meteorological conditions accompanying this event have been described using the European Centre for Medium-range Weather Forecasts (ECMWF) analyses. The gust front was initiated by a cluster of isolated cumulonimbus clouds over central Niger at 1400 UT on August 3 that lengthened to MCS size over Mali by the end of the day. At maximum expansion on August 5, the extending gust front exceeded 1500 km in length, with a transited area of lofted dust reaching a million square kilometers, mostly over southern Algeria and northern Mali. The northward gust front speed, estimated with SEVERI imagery, is rapid in initial stages but declines with time as the cold air absorbs heat from the hot desert surface and the gust front density contrast is diluted. The synoptic character of this event (both the length and the duration) allows for four intersections with CALIPSO orbits, thereby providing information on the evolution of the characteristics of the dusty gust front during its lifetime. Young dusty gust fronts (i.e. during the first 24 hours of the event) were characterized by lidar reflectivity at 532 nm in excess of 3 x 10-3 km-1 sr-1, temperature drops exceeding 10°C, 1 km visibility and their associated dense dust cloud reached 2 km in altitude. Older dusty gust fronts (i.e. from August 5 on) were associated with weaker lidar reflectivities (below 3 x 10-3 km-1 sr-1), same visibility conditions (~1km), temperature drops at the surface of about 5°C and their associated dust clouds reached higher altitudes (3-4 km). The northward transport of moisture over the Sahara desert associated with the northward excursion of the gust front was evident during this event. All gust front crossings were characterized by moisture increases at the surface. A large area (~400 km over longitude and 100 km over latitude) of high Water Vapor Mixing Ratios (up to 16 g kg-1) covered northeastern Mali and southwestern Algeria, confirming an impact at the synoptic scale. The pronounced northward propagation of the dusty gust front and its associated moisture is shown to have been favored by the presence of an active African Easterly Wave.

  14. Variation in the hindgut microbial communities of the Florida manatee, Trichechus manatus latirostris over winter in Crystal River, Florida.

    PubMed

    Merson, Samuel D; Ouwerkerk, Diane; Gulino, Lisa-Maree; Klieve, Athol; Bonde, Robert K; Burgess, Elizabeth A; Lanyon, Janet M

    2014-03-01

    The Florida manatee, Trichechus manatus latirostris, is a hindgut-fermenting herbivore. In winter, manatees migrate to warm water overwintering sites where they undergo dietary shifts and may suffer from cold-induced stress. Given these seasonally induced changes in diet, the present study aimed to examine variation in the hindgut bacterial communities of wild manatees overwintering at Crystal River, west Florida. Faeces were sampled from 36 manatees of known sex and body size in early winter when manatees were newly arrived and then in mid-winter and late winter when diet had probably changed and environmental stress may have increased. Concentrations of faecal cortisol metabolite, an indicator of a stress response, were measured by enzyme immunoassay. Using 454-pyrosequencing, 2027 bacterial operational taxonomic units were identified in manatee faeces following amplicon pyrosequencing of the 16S rRNA gene V3/V4 region. Classified sequences were assigned to eight previously described bacterial phyla; only 0.36% of sequences could not be classified to phylum level. Five core phyla were identified in all samples. The majority (96.8%) of sequences were classified as Firmicutes (77.3 ± 11.1% of total sequences) or Bacteroidetes (19.5 ± 10.6%). Alpha-diversity measures trended towards higher diversity of hindgut microbiota in manatees in mid-winter compared to early and late winter. Beta-diversity measures, analysed through PERMANOVA, also indicated significant differences in bacterial communities based on the season. PMID:24215517

  15. Expected changes in the wadden sea benthos in a warmer world: Lessons from periods with mild winters

    NASA Astrophysics Data System (ADS)

    Beukema, J. J.

    Changes observed in the macrozoobenthos at tidal flats in the westernmost part of the Wadden Sea during the 1969-1991 period were used to evaluate effects of mild winters. At least one third of the macrobenthic species in this area is sensitive to low winter temperatures. This has resulted in higher species richness and higher abundance of these species following mild as opposed to normal or cold winters. Negative effects of mild winters include greater weight loss in all bivalves during the winter and low reproductive success in the subsequent summer for various important (bivalve) species. A recent series of three mild winters in close succession (1988-1990, including the two mildest of the century) had profound effects: repeated recruitment failure in the bivalves Mya arenaria and the heavily fished Mytilus edulis and Cerastoderma edule resulted in low standing stocks of these species in the course of 1990. Effects were noted on algal stocks (elevation), other bivalves (higher weights) and predators (food shortage); problems arose particularly in the mussel and cockle fisheries as well as among the eiders ( Somateria mollissima).

  16. Variation in the hindgut microbial communities of the Florida manatee, Trichechus manatus latirostris over winter in Crystal River, Florida

    USGS Publications Warehouse

    Merson, Samuel D.; Ouwerkerk, Diane; Gulino, Lisa-Maree; Klieve, Athol; Bonde, Robert K.; Burgess, Elizabeth A.; Lanyon, Janet M.

    2014-01-01

    The Florida manatee, Trichechus manatus latirostris, is a hindgut-fermenting herbivore. In winter, manatees migrate to warm water overwintering sites where they undergo dietary shifts and may suffer from cold-induced stress. Given these seasonally induced changes in diet, the present study aimed to examine variation in the hindgut bacterial communities of wild manatees overwintering at Crystal River, west Florida. Faeces were sampled from 36 manatees of known sex and body size in early winter when manatees were newly arrived and then in mid-winter and late winter when diet had probably changed and environmental stress may have increased. Concentrations of faecal cortisol metabolite, an indicator of a stress response, were measured by enzyme immunoassay. Using 454-pyrosequencing, 2027 bacterial operational taxonomic units were identified in manatee faeces following amplicon pyrosequencing of the 16S rRNA gene V3/V4 region. Classified sequences were assigned to eight previously described bacterial phyla; only 0.36% of sequences could not be classified to phylum level. Five core phyla were identified in all samples. The majority (96.8%) of sequences were classified as Firmicutes (77.3 ± 11.1% of total sequences) or Bacteroidetes (19.5 ± 10.6%). Alpha-diversity measures trended towards higher diversity of hindgut microbiota in manatees in mid-winter compared to early and late winter. Beta-diversity measures, analysed through permanova, also indicated significant differences in bacterial communities based on the season.

  17. BEATING THE COLD: PROBABILITIES OF LOW NIGHTTIME TEMPERATURES DURING STOCKING AND HARVEST SEASONS FOR INLAND SHRIMP CULTURE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pacific white shrimp (Litopenaeus vannamei) culture in low-salinity water in inland ponds is expanding throughout the southern United States and pond culture generally is limited to early May through late October, except in the southern-most region of the country. Cold fronts can move in quickly, b...

  18. North Siberian Permafrost reveals Holocene Arctic Winter Warming

    NASA Astrophysics Data System (ADS)

    Meyer, H.; Opel, T.; Laepple, T.; Alexander, D.; Hoffmann, K.; Werner, M.

    2014-12-01

    The Arctic climate has experienced a major warming over the past decades, which is unprecedented in the last 2000 yrs. There are, however, still major uncertainties about the temperature evolution during the Holocene. Most proxy reconstructions suggest a cooling in mid-and late Holocene (e.g. Wanner, 2008), whereas climate model simulations show only weak changes or even a moderate warming (e.g. Lohmann et al., 2013). In this study, we used ice wedges as promising permafrost climate archive studied by stable water isotope methods. Ice wedges may be identified by vertically oriented foliations, and they form by the repeated filling of winter thermal contraction cracks by snow melt water in spring. Therefore, the isotopic composition of wedge ice may be attributed to the climate conditions of the cold season (i.e. winter and spring). 42 samples of organic material enclosed in ice wedges have been directly dated by Radiocarbon methods. Here, we present the first terrestrial stable oxygen isotope record of Holocene winter temperatures in up to centennial-scale resolution based on permafrost ice wedges (Lena River Delta; Siberian Arctic). The Lena ice-wedge record shows that the recent isotopic temperatures are the highest of the past 7000 years. Despite similarities to Arctic temperature reconstructions of the last two millennia (Kaufman et al., 2009), it suggests a winter warming throughout the mid and late Holocene, opposite to most existing other proxy records (Wanner, 2008). This apparent contradiction can be explained by the seasonality of the ice-wedge genesis in combination with orbital and greenhouse gas forcing and is consistent with climate model simulations. We conclude that the present model-data mismatch might be an artefact of the summer bias of the existing proxy records and thus, our record helps to reconcile the understanding of the northern hemisphere Holocene temperature evolution. This is particular true for the Russian Arctic significantly underrepresented in Arctic-wide climate reconstructions. Kaufman, D. S. et al. Science 325, 1236-1239 (2009).Wanner, H. et al. Quat. Sci. Rev. 27, 1791-1828, (2008).Lohmann, G., Pfeiffer, M., Laepple, T., Leduc, G. & Kim, J. H. Clim. Past 9, 1807-1839, (2013).

  19. Cold isopressing method

    DOEpatents

    Chen, Jack C. (Getzville, NY); Stawisuck, Valerie M. (North Tonawanda, NY); Prasad, Ravi (East Amherst, NY)

    2003-01-01

    A cold isopressing method in which two or more layers of material are formed within an isopressing mold. One of the layers consists of a tape-cast film. The layers are isopressed within the isopressing mold, thereby to laminate the layers and to compact the tape-cast film. The isopressing mold can be of cylindrical configuration with the layers being coaxial cylindrical layers. The materials used in forming the layers can contain green ceramic materials and the resultant structure can be fired and sintered as necessary and in accordance with known methods to produce a finished composite, ceramic structure. Further, such green ceramic materials can be of the type that are capable of conducting hydrogen or oxygen ions at high temperature with the object of utilizing the finished composite ceramic structure as a ceramic membrane element.

  20. Experiments in cold fusion

    SciTech Connect

    Palmer, E.P.

    1986-03-28

    The work of Steve Jones and others in muon-catalyzed cold fusion of deuterium and hydrogen suggests the possibility of such fusion catalyzed by ions, or combinations of atoms, or more-or-less free electrons in solid and liquid materials. A hint that this might occur naturally comes from the heat generated in volcanic action in subduction zones on the earth. It is questionable whether the potential energy of material raised to the height of a midocean ridge and falling to the depth of an ocean trench can produce the geothermal effects seen in the volcanoes of subduction zones. If the ridge, the trench, the plates, and the asthenosphere are merely visible effects of deeper density-gradient driven circulations, it is still uncertain that observed energy-concentration effects fit the models.