Sample records for winter cold front

  1. Compare and contrast warm and cold fronts

    NSDL National Science Digital Library

    TERC. Center for Earth and Space Science Education

    2003-01-01

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

  2. 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

  3. Constraining the Viscosity of the Intracluster Medium with Cold Fronts

    NASA Astrophysics Data System (ADS)

    ZuHone, John A.; Markevitch, M. L.; Stone, J. M.; Kunz, M.

    2014-01-01

    Cold fronts, which are sharp, smooth surface brightness discontinuities seen in X-ray observations of galaxy clusters, are potentially powerful probes of the microphysics of the intracluster medium. Cold fronts appear mostly smooth and undisrupted by fluid instabilities, which indicates a suppression mechanism. One possibility is viscosity. We have performed simulations of sloshing cold fronts in galaxy clusters with isotropic and anisotropic Spitzer viscosity, while varying the suppression factor. We show that while isotropic viscosity suppresses essentially completely the Kelvin-Helmholtz instability along cold front surfaces, anisotropic viscosity has a much weaker effect. We also show that the degree of turbulence in the sloshing cluster core is similar in the inviscid and anisotropic cases, while it is strongly suppressed with isotropic viscosity.

  4. 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.

  5. Ready.Gov for Kids: Winter Storms/Extreme Cold

    MedlinePLUS

    ... facts about Winter Storms & Extreme Cold Blackouts Drought Earthquakes Extreme Heat Floods Home Fires Hurricanes Landslides/Debris ... FEMA YouTube FEMA Blog Disaster Types Hurricanes Floods Earthquakes Wildfires Tornadoes Home Fires Blackouts Biological Threats Ready. ...

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

    E-print Network

    extratropical warm and cold fronts are obtained using two consecutive winters of CloudSat­Cloud­Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) ob- servations and National Centers for Environmental Prediction reanalysis atmospheric state parameters over the Northern and Southern Hemisphere oceans (308­708N

  7. 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.

  8. Factors controlling denitrification in recent cold Arctic winters

    NASA Astrophysics Data System (ADS)

    Mann, G. W.; Davies, S.; Carslaw, K. S.; Chipperfield, M. P.

    2003-04-01

    In this presentation we explore some of the factors that determine the rate of denitrification at a given time in an Arctic winter. In particular, the orientation of the streamlines of the wind flow on isentropic levels relative to the cold pool is found to be a dominant controlling factor. A cold pool that is concentric with the vortex allows NAT particles to stay inside the cold pool for sufficient time to grow large enough to sediment out, causing efficient denitrification. We call this a "closed flow" situation. A "through-flow" orientation is one in which the streamlines cross the cold pool. In this state, particles that have been nucleated inside the cold pool are advected out of the NAT region where they evaporate before sedimenting significantly. We present results from whole winter simulations using our 3-D microphysical model which calculates Denitrification by LAgrangian Particle Sedimentation (DLAPSE) coupled with the SLIMCAT offline chemical transport model. Case studies from previous cold Arctic winters will be shown. The results indicate that the flow conditions inside the Arctic vortex exert a very strong control over the denitrification rate, even if the NAT nucleation rate doesn't vary. Results from preliminary comparisons of the model with measurements from the EUPLEX/MAPSCORE part of the VINTERSOL field campaign will also be presented. An examination of flow conditions over the last 30 years suggests that ideal conditions for denitrification by large NAT particles occurs about 2-3 times per decade.

  9. 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

  10. Cyclone and cold front evolution over the Intermountain West

    NASA Astrophysics Data System (ADS)

    West, Gregory Lucas

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

  11. Fast simulations of gas sloshing and cold front formation

    E-print Network

    Roediger, E

    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. On the movement and low-level structure of cold fronts

    NASA Technical Reports Server (NTRS)

    Smith, Roger K.; Reeder, Michael J.

    1988-01-01

    Factors that are pertinent to the cold-front motion were examined using the results from previous studies of the low-level structure of cold fronts. Observational studies indicate the existence of two different types of behavior for a cold front. These types of behavior were related to the results of recent theoretical studies, and the mechanism responsible for front propagation was elucidated. It is shown that a necessary requirement for propagation is the existence of an alongfront temperature gradient.

  13. The Impacts of Cold Front Passages on Louisiana Coastal Environments

    NASA Astrophysics Data System (ADS)

    Feng, Z.; Li, C.; Walker, N. D.

    2008-12-01

    Time-series measurements from stations along the Louisiana coast and inside the bays, estuaries and wetlands, from Atchafalaya Bay to the Mississippi River Delta, and synoptic satellite images from MODIS and other sensors, are used to investigate the impacts of cold front passages on the coastal aquatic environments and circulation. We examine the effects of wind on water level, currents, sediment resuspension and transport. Low-frequency water level usually decreases with cold front passages, both in the inner shelf, bays and estuaries, but the variations have different phases in different areas. Cross-shore and longshore winds may have different effects, depending on the orientation of fronts and the direction of wind with respect to the coastline. Strong cross-shore winds can directly induce set-up and set-down of water level, while water level variations from longshore winds occur through the Ekman transport. Surface current is with winds on the shelf, but inside the bays and estuaries, tidal currents may dominate.

  14. Winter Cold tongue in the South China Sea

    NASA Astrophysics Data System (ADS)

    Thompson, B.; Tkalich, P.; Rizzoli, P. M.

    2014-12-01

    The South China Sea (SCS) surface circulation is mainly forced by seasonally varying monsoon winds and flow through the Luzon Strait. In winter, positive wind curl (due to the northeasterly winds) in the southern half of SCS drives a cyclonic gyre. The strong western boundary current south off Vietnam on the continental slope separates the Sunda Shelf to the west and deep SCS basin to the east. The advection of cold water due to the slope current results in a unique cold tongue in Sea Surface Temperature (SST) from November to February. The inter-annual variability of this cold-tongue is investigated by analyzing the NCEP OISST version-2 dataset. Dynamics of the evolution, growth and decay of the cold tongue during the period 1982-2012 are addressed using the OISST and ERA-interim surface wind datasets. The role of water mass advection in the inter-annual variability of SCS cold-tongue is also investigated through the analysis of lateral heat fluxes estimated from NCEP-Climate Forecast System Re-analysis dataset. The vertically integrated Ekman transport (i.e., the Sverdrup transport) plays a vital role in the formation this cold tongue. The southward Sverdrup transport brings cold water from the northern parts of the SCS. Inter-annual variations in the cold tongue SST during the northeast monsoon (November to February) are strongly linked to the north-south Sverdrup and zonal Ekman transport anomalies. The positive SST anomalies over the cold-tongue region are associated with positive transport anomalies, reflecting the weakening of the southward and westward advection. The formation and termination of this cold tongue has significant correlation with the El Nino phenomenon in the Pacific Ocean.

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

    E-print Network

    Gohm, Alexander

    gustfront gustfront Foehn in the vicinity of Innsbruck Two gust fronts propagating towards Innsbruck in the lower Wipp Valley Western Inn-Valley gust front enters Wipp Valley Cold front propagates southward Collision of two gust fronts Mean prop. speed north-south (Seefeld-Sterzing): uf 6 m/s Mean prop. speed

  18. Gas sloshing, cold front formation, and metal redistribution: the Virgo cluster as a quantitative test case

    E-print Network

    Roediger, Elke; Simionescu, Aurora; Böhringer, Hans; Churazov, Eugene; Forman, William R

    2010-01-01

    (abbreviated) We perform hydrodynamical simulations of minor-merger induced gas sloshing and the subsequent formation of cold fronts. Using the Virgo cluster as a test case, we show for the first time that the sloshing scenario can reproduce the radii and the contrasts in X-ray brightness, pro jected temperature, and metallicity across the observed cold fronts quantitatively. We identify several new features typical for sloshing cold fronts: an alternating distribution of cool, metal enriched X-ray brightness excess regions and warm brightness deficit regions of reduced metallicity; a constant or radially decreasing temperature accompanied by a plateau in metallicity inside the cold fronts; a warm rim outside the CFs; and a large-scale brightness excess towards the responsible subcluster, which will be helpful for its identification. We can trace these new features not only in Virgo, but also in other clusters exhibiting sloshing cold fronts. By comparing synthetic and real observations, we estimate that the ...

  19. 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.

  20. 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

  1. Chandra, Cold Fronts, and ICM Physics: The Importance of Magnetic Fields

    NASA Astrophysics Data System (ADS)

    ZuHone, John

    2014-11-01

    One of the most prominent features that the superb spatial resolution of Chandra has revealed in the galaxy cluster plasma is cold fronts: sharp surface brightness and temperature discontinuities formed by the motion of cold, dense gas. Cold fronts should be susceptible to disruption by fluid instabilites and smoothing out by thermal conduction, but many appear to be resilient to these effects, indicating suppression by microphysical processes. I will summarize a series of MHD simulations of sloshing cold fronts in galaxy clusters with anisotropic viscosity and thermal conduction. I will show that the power of cold front studies to provide constraints on the plasma conductivity is potentially strong, whereas the outlook for constraining the plasma viscosity is more uncertain.

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

    SciTech Connect

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

    2010-12-10

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

  3. Cold Fronts and Gas Sloshing in Galaxy Clusters with Anisotropic Thermal Conduction

    E-print Network

    ZuHone, J A; Ruszkowski, M; Lee, D

    2012-01-01

    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 fronts. We present 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 of the core and the cold fronts. Though magnetic field lines are draping parallel to the front surfaces, the temperature jumps across the fronts are nevertheless reduced. The field geometry 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 which are not perfectly draped. This results in the heating of this gas below the front on a timescale of a Gyr, ...

  4. 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

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

    E-print Network

    Effect of a Simulated Cold-Front on Hatching Success of Yellow Perch Eggs Andrew C. Jansena, Brian temperature during the first year of life (LeCren et al. 1977, Craig et al. 1979, Craig and Kipling 1983

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

    E-print Network

    Naoki Asai; Naoya Fukuda; Ryoji Matsumoto

    2007-03-20

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

  7. Dynamics of surface-air pollution during the passage of a cold front

    Microsoft Academic Search

    M. A. Lokoshchenko; N. F. Elansky

    2006-01-01

    The dynamics of meteorological parameters, of sodar data on the temperature stratification of the atmospheric boundary layer,\\u000a and of surface contents of pollutants (nitrogen oxides, carbon monoxide, and ozone) during the passage over Moscow of a structurally\\u000a complex prominent cold front are discussed. It is shown that the cold front passage is accompanied by stepwise increases in\\u000a the NO, NO2,

  8. Metal jumps across sloshing cold fronts: the case of A496

    E-print Network

    Ghizzardi, Simona; Molendi, Silvano

    2013-01-01

    Cold-fronts in cool-core clusters are thought to be induced by minor mergers and to develop through a sloshing mechanism. While temperature and surface-brightness jumps have been detected and measured in many systems, a detailed characterization of the metal abundance across the discontinuity is only available for a handful of objects. Within the sloshing scenario, we expect the central cool and metal rich gas to be displaced outwards into lower abundance regions, thus generating a metal discontinuity across the front. We analyzed a long (120 ksec) XMM-Newton observation of A496 to study the metal distribution and its correlation with the cold-fronts. We find Fe discontinuities across the two main cold-fronts located ~60 kpc NNW and ~160 kpc South of the peak and a metal excess in the South direction.

  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. A Cold Front in A3667 Hydrodynamics and Magnetic Field in the Intracluster Medium

    E-print Network

    Vikhlinin, A A

    2002-01-01

    This conference presentation discusses a Chandra observation of the cold front in Abell 3667. We first review our earlier results which include a measurement of the front velocity, M~1, using the ratio of exterior and interior gas pressures; observations of the hydrodynamic effects expected for a transonic front motion (weak bow shock and gas compression near the leading edge of the front); direct observation of the suppressed diffusion across the front, and estimate of the magnetic field strength near the front from suppression of the Kelvin-Helmholtz instabilities. The new results include using the 2-dimensional brightness distribution inside the cold front (a) to show that the front is stable and (b) to map the mass distribution in the gas cloud. This analysis confirms the existence of a dark matter subcluster traveling with the front. We also fix an algebraic error in our published calculations for the growth rate of the KH instability and discuss an additional effect which could stabilize the front again...

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

    E-print Network

    Renato A. Dupke; Raymond E. White III

    2002-12-13

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

  13. The Effect of Viscosity on Sloshing Cold Fronts in Galaxy Clusters

    NASA Astrophysics Data System (ADS)

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

    2014-07-01

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

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

    Microsoft Academic Search

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

    2003-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-01-01

    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 ~ 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.

  16. 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

  17. Factors controlling Arctic denitrification in cold winters of the 1990s

    NASA Astrophysics Data System (ADS)

    Mann, G. W.; Davies, S.; Carslaw, K. S.; Chipperfield, M. P.

    2002-12-01

    Denitrification of the Arctic winter stratosphere has been calculated using a 3-D microphysical model for the winters 1994/95, 1995/96, 1996/97 and 1999/2000. Denitrification is assumed to occur through the sedimentation of low number concentrations of large nitric acid trihydrate (NAT) particles, as observed extensively in 1999/2000. We examine whether the meteorological conditions that allowed NAT particles to grow to the very large sizes observed in 1999/2000 also occurred in the other cold winters. The results show that winter 1999/2000 had conditions that were optimum for denitrification by large NAT particles, which are a deep concentric cold pool and vortex. Under these conditions, NAT particles can circulate in the cold pool for several days, reaching several micrometres in radius and leading to a high downward flux of nitric acid. The other winters had shorter periods with optimum conditions for denitrification. However, we find that NAT particles could have grown to large sizes in all of these winters and could have caused significant denitrification. We define the quantity "closed flow area'' (the fraction of the cold pool in which air parcel trajectories can form closed loops) and show that it is a very useful indicator of possible denitrification. We find that even with a constant NAT nucleation rate throughout the cold pool, the average NAT number concentration and size can vary by up to a factor of 10 in response to this meteorological quantity. These changes in particle properties account for a high degree of variability in denitrification between the different winters. This large meteorologically induced variability in denitrification rate needs to be compared with that which could arise from a variable nucleation rate of NAT particles, which remains an uncertain quantity in models.

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

    Microsoft Academic Search

    Hans M. Hanslin; Leiv M. Mortensen

    2010-01-01

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

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

    Microsoft Academic Search

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

    2004-01-01

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

  20. 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...

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

    PubMed

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

    2015-01-01

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

  2. Feasibility of Using Composite Ground Source Heat Pump in Hot Summer and Cold Winter Region

    Microsoft Academic Search

    Jinggang Wang; Jie Liu; Ligai Kang

    2009-01-01

    Using assistant cooling composite ground source heat pump system can reduce the initial investment and enhance the efficient of energy-savings. This paper introduces the climate and the overview of building energy consumption of hot summer and cold winter region; also analyses the feasibility of ground source heat pump system using assistant cooling equipment in this region. Taking a building in

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  4. 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.

  5. Irregular sloshing cold fronts in the nearby merging groups NGC 7618 and UGC 12491: evidence for Kelvin-Helmholtz instabilities

    E-print Network

    Roediger, E; Machacek, M E; Forman, W R; Nulsen, P E J; Jones, C; Murray, S S

    2012-01-01

    We present results from two \\sim30 ks Chandra observations of the hot atmospheres of the merging galaxy groups centered around NGC 7618 and UGC 12491. Our images show the presence of arc-like sloshing cold fronts wrapped around each group center and \\sim100 kpc long spiral tails in both groups. Most interestingly, the cold fronts are highly distorted in both groups, exhibiting 'wings' along the fronts. These features resemble the structures predicted from non-viscous hydrodynamic simulations of gas sloshing, where Kelvin-Helmholtz instabilities (KHIs) distort the cold fronts. This is in contrast to the structure seen in many other sloshing and merger cold fronts, which are smooth and featureless at the current observational resolution. Both magnetic fields and viscosity have been invoked to explain the absence of KHIs in these smooth cold fronts, but the NGC 7618/UGC 12491 pair are two in a growing number of both sloshing and merger cold fronts that appear distorted. Magnetic fields and/or viscosity may be ab...

  6. Formation of a katabatic induced cold front at the east Andean slopes

    NASA Astrophysics Data System (ADS)

    Trachte, K.; Nauss, T.,; Rollenbeck, R.; Bendix, J.

    2009-04-01

    Within the DFG research unit 816, climate dynamics in a tropical mountain rain forest in the national reserve of the Reserva Biósfera de San Francisco in South Ecuador are investigated. Precipitation measurements in the mountain environment of the Estación Científica de San Francisco (ECSF) with a vertical rain radar profiler have been made over the last seven years. They reveal unexpected constant early morning rainfall events. On the basis of cloud top temperatures from corresponding GOES satellite imageries, a Mesoscale Convective System could be derived. Its formation region is located south-east of the ECSF in the Peruvian Amazon basin. The generation of the MCS is assumed to results from an interaction of both local and mesoscale conditions. Nocturnal drainage air from the Andean slopes and valleys confluences in the Amazon basin due to the concave lined terrain. This cold air converges with the warm-moist air of the Amazon inducing a local cold front. This process yields to deep convection resulting in a MCS. With the numerical model ARPS the hypothesized formation of a cloud cluster due to a katabatic induced cold front is shown in an ideal case study. Therefor an ideal terrain model representing the features of the Andes in the target area has been used. The simplification of the oprography concerns a concave lined slope and a valley draining into the basin. It describes the confluence of the cold drainage air due to the shape of the terrain. Inside the basin the generation of a local cold front is shown, which triggers the formation of a cloud cluster.

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

    PubMed

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

    2002-10-18

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

  8. 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

  9. Do radio core-halos and cold fronts in non major merging clusters originate from the same gas sloshing?

    E-print Network

    Pasquale Mazzotta; Simona Giacintucci

    2008-01-12

    We show an interesting correlation between the surface brightness and temperature structure of the relaxed clusters RXJ1720.1+2638 and MS1455.0+2232, hosting a pair of cold fronts, and their central core--halo radio source. We discuss the possibility that the origin of this diffuse radio emission may be strictly connected with the gas sloshing mechanism suggested to explain the formation of cold fronts in non major merging clusters. We show that the radiative lifetime of the relativistic electrons is much shorter than the timescale on which they can be transported from the central galaxy up to the radius of the outermost cold front. This strongly indicates that the observed diffuse radio emission is likely produced by electrons re--accelerated via some kind of turbulence generated within the cluster volume limited by the cold fronts during the gas sloshing.

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

    NASA Astrophysics Data System (ADS)

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

    2011-04-01

    Understanding seasonal variations in the evaporation of inland waters (e.g., lakes and reservoirs) is important for water resource management as well as the prediction of the hydrological cycles in response to climate change. We analyzed eddy covariance-based evaporation measurements from the Ross Barnett Reservoir (32°26'N, 90°02'W which is always ice-free) in central Mississippi during the cool months (i.e., September-March) of 2007 and 2008, and found that the variability in cold front activities (i.e., passages of cold fronts and cold/dry air masses behind cold fronts) played an important role in modulating the exchange of sensible (H) and latent (?E) heat fluxes. Our analysis showed that 2007's warmer cool season had smaller mean H and ?E than 2008's cooler cool season. This implies that the warmer cool season did not accelerate evaporation and heat exchange between the water surface and the atmosphere. Instead, more frequent cold fronts and longer periods of cold/dry air masses behind the cold fronts in 2008 resulted in overall larger H and ?E as compared with 2007, this primarily taking the form of sporadic short-term rapid 'pulses' of H and ?E losses from the water's surface. These results suggest that future climate-induced changes in frequency of cold fronts and the meteorological properties of the air masses behind cold fronts (e.g., wind speeds, temperature, and humidity), rather than other factors of climate change, would produce significant variations in the water surface's energy fluxes and subsequent evaporation rates.

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

    Microsoft Academic Search

    Michiya Koike; Takashi Okamoto; Sakae Tsuda; Ryozo Imai

    2002-01-01

    A novel cDNA clone, Tad1, was isolated from crown tissue of winter wheat after differential screening of cold acclimation-induced genes. The Tad1 cDNA encoded a 23kDa polypeptide with a potential N-terminal signal sequence. The putative mature sequence showed striking similarity to plant defensins or ?-thionins, representing low molecular size antipathogenic polypeptides. High levels of Tad1 mRNA accumulation occurred within one

  12. Did the Laki volcano eruption cause the cold winter of 1783-1784?

    NASA Astrophysics Data System (ADS)

    Tretkoff, Ernie

    2011-05-01

    In June 1783 the Laki volcano in Iceland began to erupt and continued erupting for months, causing a major environmental disaster. The eruption spewed out toxic sulfuric acid aerosols, which spread over northern latitudes and caused thousands of deaths. That summer, there were heat waves, widespread famines, crop failures, and livestock losses. During the following winter, temperatures in Europe were about 2°C below average for the late 1700s; the winter was also one of the most severe of the past 500 years in eastern North America. The Laki eruption has been blamed for the anomalously cold winter of 1783-1784. (Geophysical Research Letters, doi:10.1029/2011GL046696, 2011)

  13. 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

    located in Hunan province was conducted. Ecological technologies of the Chinese traditional folk house in the hot-Summer and cold-Winter zone were analyzed from site selection, general plane, plane design, section plane design, construction technologies...

  14. Effects of cold winters and regime shifts on macrofauna communities in shallow coastal regions

    NASA Astrophysics Data System (ADS)

    Kröncke, Ingrid; Reiss, Henning; Dippner, Joachim W.

    2013-03-01

    Several ecosystem components in the North Sea have undergone fundamental changes following climatic change and this paper aims to establish if these changes also have affected macrofauna communities in the southern North Sea. From 1978 to 2005, the macrofauna communities were sampled seasonally in the sublittoral zone off the island of Norderney, one of the East Frisian barrier islands. Abundance, biomass and species numbers of single species or larger taxonomic groups showed differences in long-term variability and eurytherm species dominated in the study area. After the cold winter of 1978/79 until the mid 1980s a higher percentage of arctic-boreal species were found, while after 1988 the percentage of species with a southern distribution in the North Sea increased in connection with a smooth biological regime shift and a positive North Atlantic Oscillation (NAO) index. Interface-feeders dominated the communities, followed by sand lickers and subsurface deposit-feeders. The latter were more abundant after cold winters, probably due to their ability to utilise dead buried faunal organic matter. Multivariate analyses revealed that cold winters affected the community structure more briefly, while a smooth biological regime shift in 1989/1990 and a climate regime shift induced abrupt biological regime shift in 2001/2002 caused longer-term progressive change in the macrofauna community structure. The significant correlation between macrofauna abundance, biomass and species number and the NAO index failed until 2001 due to a change in climate systems over the northern Atlantic hemisphere.

  15. 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.

  16. Comparison of Subjective Symptoms and Cold Prevention Measures in Winter between Traffic Control Workers and Construction Workers in Japan

    Microsoft Academic Search

    Ryoichi INABA; Junichi KUROKAWA; Seyed Mohammad MIRBOD

    2009-01-01

    To help making comfortable workplaces and to prevent health disorders induced by the exposure to moderate cold in two different groups of out-door workers, we conducted a sur- vey to compare subjective symptoms and cold prevention measures in winter between traffic con- trol workers and construction workers. The subjects of this study were 98 male traffic control workers and 149

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

    E-print Network

    Gerber, Edwin

    The role of stratosphere-troposphere coupling in the occurrence of extreme winter cold spells over ways stratospheric dynamics may influence the state of the troposphere. The study is based on 500 years the stratosphere, the MPI Earth System Model. Geopotential height anomalies leading to cold air outbreaks leave

  18. The effect of moving cold fronts over Central Europe to the variability of the ionosphere

    NASA Astrophysics Data System (ADS)

    Potuznikova, Katerina; Koucka Knizova, Petra; Boska, Josef; Sindelarova, Tereza; Mosna, Zbysek

    2015-04-01

    Cold fronts represent well known source of atmospheric waves, (especially short and medium scale AGW - acoustic gravity waves), that are able to propagate up to the ionospheric heights. In our study we focus on the effects of the transitions of cold front over the region of Central Europe on the variations of the ionosphere. We concentrate on periods of low solar and geomagnetic activity. Neutral atmosphere data are compared with the wave-like oscillations in the E and F layer. Our tropospheric data comprise synoptic maps on of 500 hPa and 850 hPa geopotential heights. Within ionospheric data we search for variability that is linked to the tropospheric disturbances. The ionospheric parameters (electron concentration and corresponding height) we analyse by the wavelet transform method. The Modern HF digisonde DPS-4 D (Digisonde Portable Sounder), which is in operation at the Pruhonice observatory (49.59 N; 14.33 E) of the Institute of Atmospheric Physics, Prague (IAP) since 2004, represents an excellent source of the ionospheric data for Central Europe. Pruhonice digisonde usually operates in standard mode - one ionogram and electron density profie N(h) each 15 minutes. Besides that, data from several european stations of the digisonde world network (data from Juliusruhe, Chilton, Brusel, Roma and Tortosa digisonde stations) are included in the study.

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

    PubMed Central

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

    2013-01-01

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

  20. 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.

  1. Behavior of GPS-derived precipitable water vapor in the mountain lee after the passage of a cold front

    NASA Astrophysics Data System (ADS)

    Okamura, Osamu; Kimura, Fujio

    2003-07-01

    A mesoscale precipitation system generated half a day after a cold front passed over the Kanto Plain in the lee of the Chubu Mountains, Japan. The behavior of precipitable water vapor (PWV) associated with this precipitation system was investigated by the use of a dense Global Positioning System (GPS) network. After the passage of the cold front, a high-level PWV zone was persistently observed over the Kanto Plain. The mesoscale precipitation system was induced in this zone. A numerical study indicated that the orographic effects on the prevailing wind are very important for sustaining the high-level PWV zone over the Kanto Plain.

  2. Factors controlling Arctic denitrification in cold winters of the 1990s

    NASA Astrophysics Data System (ADS)

    Mann, G. W.; Davies, S.; Carslaw, K. S.; Chipperfield, M. P.

    2003-04-01

    Denitrification of the Arctic winter stratosphere has been calculated using a 3-D microphysical model for the winters 1994/95, 1995/96, 1996/97 and 1999/2000. Denitrification is assumed to occur through the sedimentation of low number concentrations of large nitric acid trihydrate (NAT) particles (as inferred by e.g. Fahey et al., 2001). We examine whether the meteorological conditions that allowed particles to grow to the very large sizes observed in 1999/2000 also occurred in the other cold winters. The results show that winter 1999/2000 had conditions that were optimum for denitrification by large NAT particles, which are a deep concentric NAT area and vortex. Under these conditions, NAT particles can circulate in the NAT-supersaturated air for several days, reaching several micrometres in radius and leading to a high downward flux of nitric acid. The other winters had shorter periods with optimum conditions for denitrification. However, we find that NAT particles could have grown to large sizes in all of these winters and could have caused significant denitrification. We define the quantity "closed-flow area'' (the fraction of the NAT area in which air parcel trajectories can form closed loops) and show that it is a very useful indicator of possible denitrification. We find that even with a constant NAT nucleation rate throughout the NAT area, the average NAT number concentration and size can vary by up to a factor of 10 in response to this meteorological quantity. These changes in particle properties account for a high degree of variability in denitrification between the different winters. This large meteorologically induced variability in denitrification rate needs to be compared with that which could arise from a variable nucleation rate of NAT particles, which remains an uncertain quantity in models. Sensitivity studies show that although denitrification was likely approaching asymptotic minimum values throughout much of the 1999/2000 vortex, decreases in the volume-averaged nucleation rate would have substantially reduced the denitrification.

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

    E-print Network

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

  4. Nearshore, seasonally persistent fronts in sea surface temperature on Red Sea tropical reefs

    E-print Network

    Pineda, Jesús

    Nearshore, seasonally persistent fronts in sea surface temperature on Red Sea tropical reefs. 2011. Nearshore, seasonally persistent fronts in sea surface temperature on Red Sea tropical reefs in sea surface temperature (SST) were observed, including cold fronts (colder inshore) during winter

  5. 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

    -saving wall materials and thermal insulation systems used in projects in general, according to the climate in the zone combined with the design standard for the walls of residential buildings in the hot summer and cold winter zone. The results indicate...

  6. Influence of summer rainfall on root and shoot growth of a cold-winter desert shrub, Atriplex confertifolia

    Microsoft Academic Search

    Ken C. Hodgkinson; Pat S. Johnson; Brien E. Norton

    1978-01-01

    The influence of irrigation and nitrogen fertilization in early summer on root and shoot growth of Atriplex confertifolia, a C4 shrub species, was examined in a cold-winter desert community in northern Utah. Soil water and xylem pressure potentials were monitored during the summer period.

  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

    -saving wall materials and thermal insulation systems used in projects in general, according to the climate in the zone combined with the design standard for the walls of residential buildings in the hot summer and cold winter zone. The results indicate...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  9. Can winter-active bumblebees survive the cold? Assessing the cold tolerance of Bombus terrestris audax and the effects of pollen feeding.

    PubMed

    Owen, Emily L; Bale, Jeffrey S; Hayward, Scott A L

    2013-01-01

    There is now considerable evidence that climate change is disrupting the phenology of key pollinator species. The recently reported UK winter activity of the bumblebee Bombus terrestris brings a novel set of thermal challenges to bumblebee workers that would typically only be exposed to summer conditions. Here we assess the ability of workers to survive acute and chronic cold stress (via lower lethal temperatures and lower lethal times at 0°C), the capacity for rapid cold hardening (RCH) and the influence of diet (pollen versus nectar consumption) on supercooling points (SCP). Comparisons are made with chronic cold stress indices and SCPs in queen bumblebees. Results showed worker bees were able to survive acute temperatures likely to be experienced in a mild winter, with queens significantly more tolerant to chronic cold temperature stress. The first evidence of RCH in any Hymenoptera is shown. In addition, dietary manipulation indicated the consumption of pollen significantly increased SCP temperature. These results are discussed in the light of winter active bumblebees and climate change. PMID:24224036

  10. Can Winter-Active Bumblebees Survive the Cold? Assessing the Cold Tolerance of Bombus terrestris audax and the Effects of Pollen Feeding

    PubMed Central

    Owen, Emily L.; Bale, Jeffrey S.; Hayward, Scott A. L.

    2013-01-01

    There is now considerable evidence that climate change is disrupting the phenology of key pollinator species. The recently reported UK winter activity of the bumblebee Bombus terrestris brings a novel set of thermal challenges to bumblebee workers that would typically only be exposed to summer conditions. Here we assess the ability of workers to survive acute and chronic cold stress (via lower lethal temperatures and lower lethal times at 0°C), the capacity for rapid cold hardening (RCH) and the influence of diet (pollen versus nectar consumption) on supercooling points (SCP). Comparisons are made with chronic cold stress indices and SCPs in queen bumblebees. Results showed worker bees were able to survive acute temperatures likely to be experienced in a mild winter, with queens significantly more tolerant to chronic cold temperature stress. The first evidence of RCH in any Hymenoptera is shown. In addition, dietary manipulation indicated the consumption of pollen significantly increased SCP temperature. These results are discussed in the light of winter active bumblebees and climate change. PMID:24224036

  11. RADIATION FRONTS

    Microsoft Academic Search

    A. R. Fraser

    1958-01-01

    When intense thermal radiation penetrates into a cold fluid the front ; separating hot and cold fluid may be well defined. When this is so, conservation ; laws, similar to those which are used across a shock front, can be applied to the ; radintion front. These conservation laws, together with the second law of ; thermodynamics, are used to

  12. Radiation Fronts

    Microsoft Academic Search

    A. R. Fraser

    1958-01-01

    When intense thermal radiation penetrates into a cold fluid the front separating hot and cold fluid may be well defined. When this is so, conservation laws, similar to those which are used across a shock front, can be applied to the radiation front. These conservation laws, together with the second law of thermodynamics, are used to classify the types of

  13. 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.

  14. 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.

  15. 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: suzukikn@astro.s.chiba-u.ac.jp, E-mail: ogawa@astro.s.chiba-u.ac.jp, E-mail: ymatumot@astro.s.chiba-u.ac.jp, E-mail: matumoto@astro.s.chiba-u.ac.jp [Department of Physics, Graduate School of Science, Chiba University, Inage-ku, Chiba 263-8522 (Japan)

    2013-05-10

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2004-08-01

    Two cold front episodes were sampled during the two flights out of Yokota, Japan, during the Transport and Chemical Evolution Over the Pacific (TRACE-P) experiment during March 2001. The data from these two flights are examined using a mesoscale three-dimensional model. We show how these cyclonic systems have impacted the export of pollution out of the Asian continent. We contrast the relative role of convection and ascent in the warm conveyor belts associated with the cyclone during these two episodes. Although the necessary meteorological conditions for an efficient export of pollution are met during flight 13 (i.e., the occurrences of the warm conveyor belt near the source regions), no significant pollution is simulated in the mid-Pacific in the lower and middle troposphere. The efficient ventilation of the WCB by convection near the coast, the advection by the anticyclonical flow above 700 hPa, and the downward motion associated with the Pacific high in the remote ocean significantly prevent any long-range transport of undiluted pollution in the WCB. During flight 15 the conveyor belts have already moved to the remote ocean. The polluted plume is split by the rising air in the warm conveyor belt which transports CO-poor air northward and by the oceanic convection which transports clean air masses upward. These mechanisms lead to the dilution of Asian pollution in WCB en route to North America and add to the episodic nature of the Asian outflow by fragmenting the pollution plume.

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

    2013-06-10

    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.

  18. Gas sloshing, cold fronts, Kelvin-Helmholtz instabilities and the merger history of the cluster of galaxies Abell 496

    E-print Network

    Roediger, E; Dupke, R; Ghizzardi, S; Brüggen, M; Kraft, R P; Machacek, M E

    2011-01-01

    We investigate the origin and nature of the multiple sloshing cold fronts in the core of Abell 496 by direct comparison between observations and dedicated hydrodynamical simulations. Our simulations model a minor merger with a 4{\\times}10^13M{\\circ} subcluster crossing A496 from the south-west to the north-north-east, passing the cluster core in the south-east at a pericentre distance 100 to a few 100 kpc about 0.6 to 0.8 Gyr ago. The gas sloshing triggered by the merger can reproduce almost all observed features, e.g. the characteristic spiral-like brightness residual distribution in the cluster centre and its asymmetry out to 500 kpc, also the positions of and contrasts across the cold fronts. If the subcluster passes close (100 kpc) to the cluster core, the resulting shear flows are strong enough to trigger Kelvin-Helmholtz instabilities that in projection resemble the peculiar kinks in the cold fronts of Abell 496. Finally, we show that sloshing does not lead to a significant modification of the global IC...

  19. Impacts of Boreal Winter Monsoon Cold Surges and the Interaction with MJO on observed and projected future Southeast Asia rainfall

    NASA Astrophysics Data System (ADS)

    Marzin, Charline; Lim, See-Yee; Xavier, Prince

    2015-04-01

    The boreal winter monsoon has a pronounced effect in Southeast Asia (SEA), leading to annual flooding events in many parts of the region. There is greater concern during the months of November, December, January and February (NDJF) which are the wetter months in most parts of the region, and usually associated with cold surges that bring widespread rainfall. Although several studies related to the boreal winter monsoon in SEA have been carried out, studies focussing on the processes that influence the rainfall pattern in SEA are lacking. A generalised cold surge index has been established for the SEA region based on the NDJF season. The CSI has been defined to be easily applicable for other related weather and climate studies. Around 20% of the NDJF days in the study period were classified as cold surge days, with an average of 4-5 cold surge episodes during the NDJF season with a surge length of about 5 days. Cold surges tend to enhance the rainfall particularly over the central Maritime Continent region with contributions up to 40% of the total NDJF rainfall in some places and twice the rainfall intensity. During MJO days in phases 2-4, rainfall is observed to be significantly enhanced over most parts of the southwest SEA region, especially over the ocean to the west of Sumatra. Coexistence of MJO and cold surge days significantly enhances both mean and extreme rainfall over the central Maritime Continent and over the ocean to the west of Sumatra. The cold surge index has also been applied to CMIP5 historical and future experiments to analyse the possible impacts of climate change on cold surges and associated extreme events in SEA.

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

    NASA Astrophysics Data System (ADS)

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

    2014-02-01

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

  1. Seasonal Phase Lock of Temporal and Spatial Variations of the Lower Cold Air in the Winter Northern Hemisphere

    Microsoft Academic Search

    Hiromitsu KANNO; Jun Matsumoto

    1993-01-01

    The climatological features of temporal and spatial variations of large-scale circulation and lower cold air (LCA) in the winter northern hemisphere are investigated using 9-year mean temperature and geopotential height data, from 1980 to 1988. The large-scale circulation pattern abruptly changes in late December (the 70th pentad) and mid-February (the 9th pentad), and shows a more meandering pattern in the

  2. 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

    with residential area having no virescence, air relative humidity of the former be higher 10 to 20 percent in winter and 20 to 30 percent in summer. In the meantime, the reasonable distribution of virescence cannot only carry excrescent hot air inside off... shining upon walls and windows directly, which affects inside hot environment seriously and aggravates cold burden of air condition system. Therefore, while carrying on energy-saving renovation to the existing residential buildings, the improvement...

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

    Microsoft Academic Search

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

    2003-01-01

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

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

    E-print Network

    and the Department of Philosophy for assistance with the publication of this issue. Winter/Spring 2004 Volume 27, Number 1 CONTENTS ARTICLES Dawn M. Gale Hare's Error Justin McBrayer Evidential Arguments from Evil and the "Seeability" of Compensating Goods... Jason L. Megill Are We Paraconsistent? On the Luco-Penrose Argument and the Computational Theory of Mind Larry J. Waggle Inquiry in Plato's Meno What Are We Supposed to Learn From the Experiment with the Slave Boy? Heath White Foundationalism...

  5. Sloshing cold fronts in galaxy groups and their perturbing disk galaxies: an X-ray, Optical and Radio Case Study

    E-print Network

    Gastaldello, F; Ghizzardi, S; Giacintucci, S; Girardi, M; Roediger, E; Rossetti, M; Brighenti, F; Buote, D A; Eckert, D; Ettori, S; Humphrey, P J; Mathews, W G

    2013-01-01

    We present a combined X-ray, optical, and radio analysis of the galaxy group IC 1860 using the currently available Chandra and XMM data, literature multi-object spectroscopy data and 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 ide

  6. Regulation of RNA Synthesis by DNA-Dependent RNA Polymerases and RNases during Cold Acclimation in Winter and Spring Wheat.

    PubMed

    Sarhan, F; Chevrier, N

    1985-06-01

    Chromatin DNA-dependent RNA polymerases and RNases activities were measured in winter and spring varieties to understand the overall regulation of RNA synthesis during cold acclimation. We found that total RNA polymerase activities were significantly higher in chromatin isolated from winter wheat compared to the spring wheat during the acclimation period. This increase was parallel to the increase in protein and RNA contents during hardening. The ratio of RNA polymerase I to RNA polymerase II activity was higher than 2 in winter wheat after 30 days of hardening compared, to a ratio of 0.90 under the nonhardening conditions. The increase in activity and the ratio of polymerase I to polymerase II was maintained after the separation of the enzymes from the template, suggesting that RNA synthesis is regulated in part at the enzyme level. On the other hand, the chromatin associated RNase activity decreased in both varieties during acclimation, indicating a nonspecific inhibition caused by low temperature rather than a selective genetic response associated with cold acclimation. PMID:16664225

  7. 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 6.24mg/kg at Evros Delta and 7.34mg/kg at Lake Kerkini (maximum values of 28.61mg/kg and 36.68mg/kg, respectively); for fecal samples of GWfG geometric means were 2.39mg/kg at Evros Delta and 6.90mg/kg at Kerkini (corresponding maximum values of 25.09mg/kg and 42.26mg/kg). Soil Pb was in the range of 5.2-60.2mg/kg (geometric mean=22.6mg/kg) for the Evros Delta and between 13.4 and 64.9mg/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

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

    E-print Network

    Reding, Philip John

    1992-01-01

    UTC. . . . 65 Total precipitable water (kg/m2) field on 26 November 1987, 0600 UTC. . . . 66 39 40 41 42. Rain rate (mm/h) on 19 November 1987, 0600 UTC. . . . Rain rate (mm/h) on 21 November 1987, 1800 UTC, . . . GOES IR satellite image... on 29 January 1988, 1800 UTC. . . . . 143 87. Rain rate (mm/h) on 21 January 1988, 0600 UTC. . . 88. Rain rate (mm/h) on 28 January 1988, 1800 UTC. . . 89. Rain rate (mm/h) on 30 January 1988, 0600 UTC. . . 90. The Central American Cold Surge: Phase...

  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

    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.

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

    PubMed

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

    2009-07-01

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

  11. 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

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

    PubMed

    Cloutier, Y; Siminovitch, D

    1982-01-01

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

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

    SciTech Connect

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

    2012-08-01

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

  14. 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.

  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. Cbf genes of the FrA2 allele are differentially regulated between long-term cold acclimated crown tissue of freeze-resistant and – susceptible, winter wheat mutant lines

    Microsoft Academic Search

    Fedora Sutton; Ding-Geng Chen; Xijin Ge; Don Kenefick

    2009-01-01

    BACKGROUND: In order to identify genes that might confer and maintain freeze resistance of winter wheat, a comparative transcriptome analysis was performed between control and 4 wk cold-acclimated crown tissue of two winter wheat lines that differ in field freeze survival. The lines, generated by azide mutagenesis of the winter wheat cultivar 'Winoka' were designated FR (75% survival) and FS

  17. During winters,the northern Adriatic Sea experiences frequent,intense cold-air out-

    E-print Network

    Cushman-Roisin, Benoit

    ,fresher), stratified waters of the Po River plume.Once subducted at the front,the NAdDW flows south- ward in a narrow large observational and numerical modeling programs. The Dynamics of Localized Currents and Eddy to strong atmospheric and riverine forcing within the context of large-scale circulation studies conducted

  18. Energy savings potential of a desiccant assisted hybrid air source heat pump system for residential building in hot summer and cold winter zone in China

    Microsoft Academic Search

    Fenghua Ge; Xinglong Guo; Zicheng Hu; Yi Chu

    2011-01-01

    In hot summer and cold winter zone in China, air conditioning system has four running modes yearly including cooling with dehumidification, cooling, dehumidification and heating in residential buildings. The conventional air source heat pump (ASHP) system is not designed to independently control temperature and humidity, and is not very suitable for the dehumidification mode in the view of building energy

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

    PubMed

    Lewden, Agnès; Petit, Magali; Vézina, François

    2012-04-01

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

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

    PubMed Central

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

    2013-01-01

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

  1. Water balance of over-wintering beetles in relation to strategies for cold tolerance

    Microsoft Academic Search

    R. Lundheim; K. E. Zachariassen

    1993-01-01

    The vapour pressure of the haemolymph of a supercooled insect is higher than the vapour pressure of the haemolymph of a frozen insect at the same temperature. The aim of the study was to see whether this may affect the water loss of freeze-avoiding and freezetolerant, over-wintering beetles. The rates of water loss were determined on freeze-tolerant Pytho depressus larvae

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

    NASA Astrophysics Data System (ADS)

    Ogura, Yoshi; Portis, Diane

    1982-12-01

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

  3. Impacts of a strong cold front on concentrations of HONO, HCHO, O 3, and NO 2 in the heavy traffic urban area of Beijing

    Microsoft Academic Search

    Junling An; Wei Zhang; Yu Qu

    2009-01-01

    Much rain and strong winds caused by a cold front occurred in Beijing during the period of Sep. 27 to Oct. 4, 2004 and led to sharp drops in maximum and mean concentrations of HONO, HCHO, O3, and NO2, i.e., the maximum concentrations were reduced by 5.9, 21.3, 45.6, and 44.4 ppb, respectively, and the mean concentrations were decreased by 4.0,

  4. Sixteen years of winter stress: an assessment of cold hardiness, growth performance and survival of hybrid poplar clones at a boreal planting site.

    PubMed

    Schreiber, Stefan G; Hamann, Andreas; Hacke, Uwe G; Thomas, Barb R

    2013-02-01

    In recent years, thousands of hectares of hybrid poplar plantations have been established in Canada for the purpose of carbon sequestration and wood production. However, boreal planting environments pose special challenges that may compromise the long-term survival and productivity of such plantations. In this study, we evaluated the effect of winter stress, that is, frequent freeze-thaw and extreme cold events, on growth and survival of 47 hybrid poplar clones in a long-term field experiment. We further assessed physiological and structural traits that are potentially important for cold tolerance for a selected set of seven clones. We found that trees with narrow xylem vessels showed reduced freezing-induced embolism and showed superior productivity after 16 growing seasons. With respect to cold hardiness of living tissues, we only observed small differences among clones in early autumn, which were nonetheless significantly correlated to growth. Maximum winter cold hardiness and the timing of leaf senescence and budbreak were not related to growth or survival. In conclusion, our data suggest that reduction of freezing-induced embolism due to small vessel diameters is an essential adaptive trait to ensure long-term productivity of hybrid poplar plantations in boreal planting environments. PMID:22897210

  5. Winter storm impacts on chenier plain coast of southwestern Louisiana

    SciTech Connect

    Roberts, H.H.; Huh, O.K.; Hsue, S.A.; Rouse, L.J. Jr. (Louisiana State Univ., Baton Rouge (USA)); Rickman, D.A. (Stennis Space Center, Bay St. Louis, MS (USA))

    1989-09-01

    Stormy conditions associated with periodic winter cold front passages are closely related to transport of suspended sediment to the continental shelf, coastal erosion, and coastal progradation along shoreline sectors where abundant fine-grained sediments are stored on the inner shelf. Cold front passages occur between October and April on 3 to 5-day cycles. Their typical northwest to southeast direction of approach, large spatial scales, and numerous yearly occurrences (20-30 cycles/year) drive physical processes that cause significant coastal change. Acquisition of both remotely sensed multispectral and high-quality photographic data, collected from altitudes of 1,500, 9,000, and 21,000 m before and after cold front passages, forms a database for evaluating coastal change and suspended sediment transport pathways. Satellite imagery provide a longer term perspective on coastal change. Remotely sensed data sets are augmented with ground truth measurements of coastal configuration, sedimentological framework, and water quality.

  6. Bottom currents during early winter on south Texas continental shelf: implications for shelf sediment transport

    Microsoft Academic Search

    J. W. Snedden; A. F. Amos; D. Nummedal

    1985-01-01

    During a 42-day period in the early winter of 1981, bottom currents and temperature were measured by a current meter moored 2 m off bottom in 130 m of water on the south Texas continental shelf. During this time, nine cold fronts passed over the area, bringing about substantial changes in the overlying field. Particularly significant were the strong southeasterly

  7. 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

  8. 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.

  9. 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.

  10. Kelvin-Helmholtz instabilities at the sloshing cold fronts in the Virgo cluster as a measure for the effective ICM viscosity

    E-print Network

    Roediger, E; Forman, W R; Nulsen, P E J; Churazov, E

    2012-01-01

    Sloshing cold fronts (CFs) arise from minor merger triggered gas sloshing. Their detailed structure depends on the properties of the intra-cluster medium (ICM): hydrodynamical simulations predict the CFs to be distorted by Kelvin-Helmholtz instabilities (KHIs), but aligned magnetic fields, viscosity, or thermal conduction can suppress the KHIs. Thus, observing the detailed structure of sloshing CFs can be used to constrain these ICM properties. Both smooth and distorted sloshing CFs have been observed, indicating that the KHI is suppressed in some clusters, but not in all. Consequently, we need to address at least some sloshing clusters individually before drawing general conclusions about the ICM properties. We present the first detailed attempt to constrain the ICM properties in a specific cluster from the structure of its sloshing CF. Proximity and brightness make the Virgo cluster an ideal target. We combine observations and Virgo-specific hydrodynamical sloshing simulations. Here we focus on a Spitzer-li...

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

    SciTech Connect

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

    1990-09-01

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

  12. Even though Escambia County winters can be relatively mild, wildlife still have to find food when the cold winds blow. People establish environments conducive to wildlife for a variety of

    E-print Network

    Watson, Craig A.

    Even though Escambia County winters can be relatively mild, wildlife still have to find food when the cold winds blow. People establish environments conducive to wildlife for a variety of reasons, and depending on your intent, there are different methods of providing food for wildlife. Many hunting

  13. 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. (Cornell Univ., Ithaca, NY (USA))

    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.

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

    PubMed Central

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

    1996-01-01

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

  15. Winter energy behaviour in multi-family block buildings in a temperate-cold climate in Argentina

    Microsoft Academic Search

    C. Filippín; S. Flores Larsen; V. Mercado

    2011-01-01

    This paper analyzes the thermal and energy behaviour of apartments in three-story block buildings located along a NE-SW axis (azimuth=120°) in a temperate-cold climate (latitude: 36°57?; longitude: 64°27?) in the city of Santa Rosa, La Pampa, central Argentina. Four apartments had been monitored during May and June 2009. Three of them are located in Block 126. Two of these apartments

  16. Apoplastic Sugars, Fructans, Fructan Exohydrolase, and Invertase in Winter Oat: Responses to Second-Phase Cold Hardening

    Microsoft Academic Search

    David P. Livingston III; Cynthia A. Henson

    1998-01-01

    Changes in apoplastic carbohydrate concentrations and activities of carbohydrate-degrading enzymes were determined in crown tis- sues of oat (Avena sativa L., cv Wintok) during cold hardening. During second-phase hardening (23°C for 3 d) levels of fructan, sucrose, glucose, and fructose in the apoplast increased significantly above that in nonhardened and first-phase-hardened plants. The extent of the increase in apoplastic fructan

  17. 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.

  18. Validation and analysis of high-resolution atmospheric model simulations of the cold Bora outbreak over the Northern Adriatic Sea in winter 2012

    NASA Astrophysics Data System (ADS)

    Stocchi, Paolo; Davolio, Silvio; Marcello Miglietta, Mario; Carniel, Sandro; Benetazzo, Alvise; Li, Xiao-Ming; Bohm, Emanuele

    2014-05-01

    The Adriatic Sea is regularly affected by cold and strong Bora winds blowing from the north-east, especially during the winter season. These events are characterized by intense surface heat loss and air-sea exchange, thus producing strong effects on the circulation of the Adriatic, triggering dense water formation and driving basin-scale gyres. Turbulent surface (latent and sensible) heat fluxes and Sea Surface Temperature (SST) are the two most important parameters that characterize intense air-sea interactions typical of Bora events, and their accurate simulation is required in order to properly describe and understand atmospheric and ocean circulation processes. This study deals mainly with the atmospheric component of the modelling system available in the framework of the flagship Project "RITMARE", and presents the results of an application focused on the exceptional Bora episode occurred in winter 2012 (25 January-15 February). A number of short-range high-resolution atmospheric simulations have been performed to cover the entire period. Model performances have been evaluated in terms of variables of interest for oceanographic applications. As far as meteorological variables, surface fluxes and SST are concerned, the validation has been undertaken trough a comparison with available surface data (buoys) and satellite-derived SST, while Synthetic Aperture Radar (SAR) products have been used to assess modelled wind fields. Two mesoscale operational-like modelling chains have been implemented, one based on BOLAM-MOLOCH models, the other on WRF. The use of different initial and boundary conditions provided by two global NWP systems, namely GFS (NCEP) and IFS (ECWMF), driving the high-resolution simulations turned out to have a remarkable impact on the results, mainly as a consequence of a different initialization of the SST field. Results suggest the importance of adopting full bi-directional coupling between atmospheric and ocean circulation models at least in this semi-enclosed basin during extreme events.

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

    SciTech Connect

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

    2013-02-10

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

  20. Ocean backscatter across the Gulf Stream sea surface temperature front

    SciTech Connect

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

    1997-06-01

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

  1. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

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

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

    E-print Network

    Queitsch, Christine

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

  4. 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.

  5. Stationary fronts prolong bad weather

    NSDL National Science Digital Library

    John Herne

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

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

    ERIC Educational Resources Information Center

    Neal, Larry; Coles, Roger, Ed.

    1989-01-01

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

  7. PM10 modeling of Beijing in the winter

    NASA Astrophysics Data System (ADS)

    Song, Yu; Zhang, Minsi; Cai, Xuhui

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

  8. Phospholipase A2 activity during cold acclimation of wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  9. How Cold Is Cold?

    NSDL National Science Digital Library

    Richard Konicek-Moran

    2008-04-01

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

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

    Microsoft Academic Search

    David L. Swanson

    2001-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2011-03-01

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

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

    NASA Astrophysics Data System (ADS)

    Politovich, Marcia K.; Bernstein, Ben C.

    1995-12-01

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

  13. Winter Storms

    NSDL National Science Digital Library

    1996-01-01

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

  14. Winter performance of an urban stormwater pond in southern Sweden

    Microsoft Academic Search

    Annette Semadeni-Davies

    2006-01-01

    Evidence from cold regions in North America has shown that the performance of stormwater ponds differs between winter and summer. The pond hydraulics change seasonally, and winters have lowered removal efficiency due to a combination of an ice cover, cold water and de-icing salts. This study examines the function of the Bäckaslov stormwater pond under the more mild conditions of

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

    NSDL National Science Digital Library

    New England Aquarium

    2011-01-01

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

  16. QTL MAPPING OF WINTER HARDINESS GENES IN LENTIL

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  17. a Climatology of Extreme Minimum Winter Temperatures in Ohio

    Microsoft Academic Search

    Dennis Joe Edgell

    1992-01-01

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

  18. 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

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

    PubMed Central

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

    1994-01-01

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

  20. 3. Front of Mansion, facing east, shows portico, raised section ...

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

    3. Front of Mansion, facing east, shows portico, raised section of second story, and section (south of extreme left chimney) added c. 1914. Winter view. - Sotterly, State Route 245 & Vista Road Vicinity, Hollywood, St. Mary's County, MD

  1. 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…

  2. Winter Ecology.

    ERIC Educational Resources Information Center

    Birkeland, Karl W.; Halfpenny, James C.

    1987-01-01

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

  3. 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...

  4. Documentary evidence of climate variability during cold seasons in Lesotho, southern Africa, 1833-1900

    NASA Astrophysics Data System (ADS)

    Grab, S. W.; Nash, D. J.

    2009-04-01

    This study presents the first 19th century cold season climate chronology for the Kingdom of Lesotho in southern Africa. The chronology is constructed using a variety of documentary sources including letters, diaries, reports, monographs and newspaper articles obtained from southern African and British archives. Information relating to cold season weather phenomena during the austral autumn, winter and early spring months were recorded verbatim. Each of the cold seasons from 1833 to 1900 was then classified as ‘very severe', ‘severe' or ‘normal/mild', with a confidence rating ranging from low (1) to high (3) awarded against each annual classification. The accuracy of the document-derived chronology was verified against temperature data for Maseru for the period 1893-1900. Excellent correspondence of the document-derived chronology with the Maseru instrumental data and also with other global proxy temperature records for the 19th century is achieved. The results indicate 12 (18% of the total) very severe, 16 (23%) severe and 40 (59%) normal/mild cold seasons between 1833 and 1900. The overall trend is for more severe and snow-rich cold seasons during the early part of the study period (1833-1854) compared with the latter half of the 19th century (with the exception of the 1880s). A reduction in the duration of the frost season by over 20 days during the 19th century is also tentatively identified. Several severe to very severe cold seasons in Lesotho follow after major tropical and SH volcanic eruptions; such years are usually characterized by early frosts, and frequent and heavy snowfalls. The blocking of solar radiation and the enhanced northward displacement of polar fronts that are directly or indirectly associated with volcanic events, may account for many of the most severe Lesotho winters during the 19th century. Keywords: Cold season chronology, 19th century, Lesotho, volcanic forcing

  5. Surviving Winter

    NSDL National Science Digital Library

    2010-11-17

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

  6. Seasonal variability of coastal upwelling and the upwelling front off central Chile

    NASA Astrophysics Data System (ADS)

    Letelier, Jaime; Pizarro, Oscar; NuñEz, Sergio

    2009-12-01

    We analyze sea surface temperature (SST) and chlorophyll a (Chl a) satellite data to study the seasonal variability of the upwelling off central Chile. Data from an oceanographic cruise are used to illustrate the vertical characteristics of the upwelling front and the geostrophic flow. The mean offshore extension of the SST front in summer is ˜110 km. There, SST changes from ˜13.5°C near the coast to 14.5°-15°C offshore. Hydrographic data show that the thermocline becomes progressively shallower toward the coast but that at a certain distance it abruptly bends to form a horizontal front that extends until ˜50 m depth. Satellite data show that the Chl a decays exponentially offshore, and a concentration of ˜1 mg m-3 indicates the offshore limit of the frontal region. The SST front observed most of the year is absent in winter, when the coastal water is only slightly colder than the oceanic one; however, relatively higher Chl a values remain present near the coast during winter. Northwest of Punta Lavapie (37°15'S), the frontal region is located progressively farther offshore, suggesting that a branch of an equatorward surface jet separates from the coast to form a meander, which is associated with a filament of cold water and an anticyclonic eddy observed frequently in this zone during summer. Hydrographic data show that isotherm and current disturbances related to mesoscale eddies can extend several hundreds of meters below the surface. In contrast, the coastal jet is quite shallow, extending until ˜150 m depth.

  7. Changing mountain permafrost from the 1970s to today comparing twoChanging mountain permafrost from the 1970s to today comparing two examples from Niwot Ridge, Colorado Front Range, USAexamples from Niwot Ridge, Colorado Front Range, USA

    E-print Network

    Williams, Mark W.

    the freezing front down to 2 m depth during the early winter, the melting process duringshow the freezing front from the 1970s to today ­ comparing two examples from Niwot Ridge, Colorado Front Range, USAexamples from Niwot Ridge, Colorado Front Range, USA Matthias Leopold, Jörg Völkel, David P. Dethier and Mark W

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

    USGS Publications Warehouse

    Bergstedt, Roger A.; O'Gorman, Robert

    1989-01-01

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

  9. Climate warming will not decrease winter mortality

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

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

  10. Documentary evidence of climate variability during cold seasons in Lesotho, southern Africa, 1833-1900

    NASA Astrophysics Data System (ADS)

    Grab, Stefan W.; Nash, David J.

    2010-03-01

    This study presents the first 19th century cold season climate chronology for the Kingdom of Lesotho in southern Africa. The chronology is constructed using a variety of documentary sources including letters, diaries, reports, monographs and newspaper articles obtained from southern African and British archives. Information relating to cold season weather phenomena during the austral autumn, winter and early spring months were recorded verbatim. Each of the cold seasons from 1833 to 1900 was then classified as “very severe”, “severe” or “normal/mild”, with a confidence rating ranging from low (1) to high (3) awarded against each annual classification. The accuracy of the document-derived chronology was verified against temperature data for Maseru for the period 1893-1900. Excellent correspondence of the document-derived chronology with the Maseru instrumental data and also with other global proxy temperature records for the 19th century is achieved. The results indicate 12 (18% of the total) very severe, 16 (23%) severe and 40 (59%) normal/mild cold seasons between 1833 and 1900. The overall trend is for more severe and snow-rich cold seasons during the early part of the study period (1833-1854) compared with the latter half of the 19th century (with the exception of the 1880s). A reduction in the duration of the frost season by over 20 days during the 19th century is also tentatively identified. Several severe to very severe cold seasons in Lesotho follow after major tropical and SH volcanic eruptions; such years are usually characterized by early frosts, and frequent and heavy snowfalls. The blocking of solar radiation and the enhanced northward displacement of polar fronts that are directly or indirectly associated with volcanic events, may account for many of the most severe Lesotho winters during the 19th century.

  11. 42 | NewScientist | 17 December 2011 Blowing hot and cold

    E-print Network

    42 | NewScientist | 17 December 2011 Blowing hot and cold During northern hemisphere winters, cold. When these winds weaken, cold air spills south in places while warm air flows north NORMAL WEATHER of extreme cold ­ but even larger areas were unusually warm POLAR JET STREAM Is the freakishly cold weather

  12. Winter season mortality: will climate warming bring benefits?

    NASA Astrophysics Data System (ADS)

    Kinney, Patrick L.; Schwartz, Joel; Pascal, Mathilde; Petkova, Elisaveta; Le Tertre, Alain; Medina, Sylvia; Vautard, Robert

    2015-06-01

    Extreme heat events are associated with spikes in mortality, yet death rates are on average highest during the coldest months of the year. Under the assumption that most winter excess mortality is due to cold temperature, many previous studies have concluded that winter mortality will substantially decline in a warming climate. We analyzed whether and to what extent cold temperatures are associated with excess winter mortality across multiple cities and over multiple years within individual cities, using daily temperature and mortality data from 36 US cities (1985–2006) and 3 French cities (1971–2007). Comparing across cities, we found that excess winter mortality did not depend on seasonal temperature range, and was no lower in warmer vs. colder cities, suggesting that temperature is not a key driver of winter excess mortality. Using regression models within monthly strata, we found that variability in daily mortality within cities was not strongly influenced by winter temperature. Finally we found that inadequate control for seasonality in analyses of the effects of cold temperatures led to spuriously large assumed cold effects, and erroneous attribution of winter mortality to cold temperatures. Our findings suggest that reductions in cold-related mortality under warming climate may be much smaller than some have assumed. This should be of interest to researchers and policy makers concerned with projecting future health effects of climate change and developing relevant adaptation strategies.

  13. Pressure transient method for front tracking

    SciTech Connect

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

    1983-08-01

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

  14. 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.

  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. 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).

  17. 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,…

  18. Winter Depression

    NSDL National Science Digital Library

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

  19. Winter Math

    NSDL National Science Digital Library

    Wendy Petti

    2009-01-13

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

  20. Modeling Experiment for winter circulation in Calcasieu Lake, LA

    NASA Astrophysics Data System (ADS)

    Lin, J.; Li, C.; Boswell, K.; Kimball, M.; Rozas, L.; Broussard, L.; Zhang, F.

    2013-12-01

    Cold-front-induced water level oscillation and associated salinity distributions in Calcasieu Lake, southwestern Louisiana, were examined using a numerical model and field observations. The cold-front-induced flushing under the influence of Calcasieu River runoff, local wind stress, and tide determine the hydrodynamic features of Calcasieu Lake in winter. Based on observations carried out from Dec. 20, 2011 to Feb. 1, 2012, numerical model experiments with different conditions were conducted. The model predicts a depth-averaged flow pattern over the domain consisting of the shallow Calcasieu Lake and deep Ship Channel. A clockwise circulation in Calcasieu Lake coupled with the Ship Channel and a counterclockwise circulation in West Cove were demonstrated. It is through the shallow shoals, not the deep Ship Channel, that water from Calcasieu Lake flows into the ocean. This circulation pattern is typical of estuaries with shallow water influenced by river discharge and with weak tidally-induced motion. Both the observations and the model indicate saltwater intrusion along the Ship Channel into the northern lake. Salinity gradient induced baroclinic pressure gradient and Coriolis force also play relatively important roles in the circulation of Calcasieu Lake. Local wind stress played a negative role in the saltwater intrusion along the Ship Channel except under an east wind. The depth of the Ship Channel is a key factor influencing saltwater intrusion, the deeper the Channel, the more saltwater intrusion. Saltwater intrusion along the Ship Channel increases the magnitude of the Lake circulation and moderates salinity changes in adjacent wetlands caused by heavy rainfall. Circulation indicated by sum of water mass flux at transects Modeling experiment schedule

  1. 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.

  2. Endothermic heat production in honeybee winter clusters.

    PubMed

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

    2003-01-01

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

  3. Winter Storm

    NSDL National Science Digital Library

    Miss Liz

    2010-05-26

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

  4. Winter Storm

    NSDL National Science Digital Library

    Miss Smith

    2010-09-27

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

  5. Winter Storm

    NSDL National Science Digital Library

    Sarah

    2009-09-28

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

  6. Winter Storms

    NSDL National Science Digital Library

    Mr. Sappa

    2010-05-26

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

  7. Winter Storm

    NSDL National Science Digital Library

    Ashley Schilling

    2010-05-26

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

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

    E-print Network

    Rohr, Jason

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

  9. Winter snow

    NSDL National Science Digital Library

    Lori Peterson

    2009-09-28

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

  10. 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)

  11. 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.

  12. 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

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

    NASA Astrophysics Data System (ADS)

    Tyrrell, John

    2007-02-01

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

  14. Interannual salinity variability of the Northern Yellow Sea Cold Water Mass

    NASA Astrophysics Data System (ADS)

    Li, Ang; Yu, Fei; Diao, Xinyuan

    2015-05-01

    This paper discusses the interannual variability of the Northern Yellow Sea Cold Water Mass (NYSCWM) and the factors that influence it, based on survey data from the 1976-2006 national standard section and the Korea Oceanographic Data Center, monthly E-P flux data from the European Centre for Medium-Range Weather Forecasts, and meridional wind speed data from the International Comprehensive Ocean-Atmosphere Data Set. The results show that: 1) the mean salinity of the NYSCWM center has a slightly decreasing trend, which is not consistent with the high salinity center; 2) both the southern salinity front and the halocline of the NYSCWM display a weakening trend, which indicates that the difference between the NYSCWM and coastal water decreases; 3) the Yellow Sea Warm Current intrusion, the E-P flux of the northern Yellow Sea, and the strength of the winter monsoon will affect the NYSCWM salinity during the following summer.

  15. 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.

  16. Effects of Topography on Fronts.

    NASA Astrophysics Data System (ADS)

    Williams, R. T.; Peng, Melinda S.; Zankofski, D. A.

    1992-02-01

    The hydrostatic Boussinesq equations are used to simulate the passage of fronts over a two-dimensional mountain in a cyclic domain. The fronts are forced by a confluent, periodic deformation field that moves with the uniform mean flow over the mountain. The initial conditions are selected to give a cold front confined to the lower part of the domain. Fourth-order diffusion terms are included in the numerical model to control energy cascade to the grid size scale. A numerical frontogenesis experiment with no topography produces a realistic surface front in about two days. Numerical solutions for flow over the mountain with no front are found by integrating the equations from the initial conditions, which are semigeostrophic steady-state solutions. Various mountains are considered that have the same height but different widths. The numerical solutions for wide mountains remain close to the semigeostrophic initial conditions, while for narrower mountains vertically propagating waves and a hydraulic jump develop on the lee side of the mountain. The frontal solution and the mountain solution are combined to produce the initial conditions for the basic experiments. The numerical solutions show reduced frontogenesis on the upwind slope and increased frontogenesis on the lee slope. This behavior is caused by the mountain-forced divergence on the upwind side and convergence on the lee side in agreement with the semigeostrophic solution of Zehnder and Bannon. Further experiments with no deformation forcing are carried out to correspond to the semigeostrophic passive scalar studies of Blumen and Gross. A passive scalar that represents the perturbation potential temperature is advected with the mountain solution. The frontal scale, based on the tracer field, increases on the upwind side until it reaches a maximum at the top and then decreases on the lee side, back to its original value as the front moves away from the mountain. The numerical solutions for the interactive potential temperature field have a similar behavior, although some additional blocking effects are present. For the narrower mountains the frontal structure is distorted by the gravity waves on the lee side of the mountain. These solutions resemble those of Schumann for smaller-scale mountains.

  17. Supercooling and Freezing in Winter Dormant Animals

    NSDL National Science Digital Library

    William D. Schmid (University of Minnesota; )

    2008-04-11

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

  18. Radar Backscatter Across the Gulf Stream Sea Surface Temperature Front

    NASA Technical Reports Server (NTRS)

    Nghiem, S. V.; Li, F. K.; Walsh, E. J.; Lou, S. H.

    1998-01-01

    Ocean backscatter signatures were measured by the Jet Propulsion Laboratory airborne NUSCAT K(sub u)-band scatterometer across the Gulf Stream sea surface temperature front. The measurements were made during the Surface Wave Dynamics Experiment (SWADE) off the coast of Virginia and Maryland in the winter of 1991.

  19. 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...

  20. 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.

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

    Microsoft Academic Search

    Jacques Régnière; Barbara Bentz

    2007-01-01

    Cold-induced mortality is a key factor driving mountain pine beetle, Dendroctonus ponderosae, population dynamics. In this species, the supercooling point (SCP) is representative of mortality induced by acute cold exposure. Mountain pine beetle SCP and associated cold-induced mortality fluctuate throughout a generation, with the highest SCPs prior to and following winter. Using observed SCPs of field-collected D. ponderosae larvae throughout

  2. Reducing the crystallization temperature of biodiesel by winterizing methyl soyate

    Microsoft Academic Search

    Inmok Lee; Lawrence A. Johnson; Earl G. Hammond

    1996-01-01

    Methyl soyate, made from typical soybean varieties, has a crystallization onset temperature (T\\u000a co) of 3.7°C and, as a biodiesel fuel, is prone to crystallization of its high-melting saturated methyl esters at cold operating\\u000a temperatures. Removal of saturated esters by winterization was assessed as a means of reducing theT\\u000a co of methyl soyate. Winterizing neat methyl esters of typical soybean

  3. Evaluation of Cold Temperatures and Density as Mortality Factors of the Eucalyptus Longhorned Borer

    E-print Network

    Hanks, Lawrence M.

    Evaluation of Cold Temperatures and Density as Mortality Factors of the Eucalyptus Longhorned Borer semipunctata F., in California is limited by winter temperature con- ditions. The cold tolerance of prepupal stages was tested by exposing infested logs to cold temperature treatments of -5, 0, +5, and + l

  4. 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.

  5. Common Cold

    MedlinePLUS

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

  6. Cold Sores

    MedlinePLUS

    ... causes oral herpes, or cold sores. Type 1 herpes virus infects more than half of the U.S. population by the time they reach their 20s. Type 2 usually affects the genital area Some people have no symptoms from the ...

  7. Cold War

    NSDL National Science Digital Library

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

  8. 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

  9. Winter marine atmospheric conditions over the Japan Sea

    NASA Astrophysics Data System (ADS)

    Dorman, C. E.; Beardsley, R. C.; Dashko, N. A.; Friehe, C. A.; Kheilf, D.; Cho, K.; Limeburner, R.; Varlamov, S. M.

    2004-12-01

    Four basic types of synoptic-scale conditions describe the atmospheric structure and variability observed over the Japan Sea during the 1999/2000 winter season: (1) flow of cold Asian air from the northwest, (2) an outbreak of very cold Siberian air from the north and northeast, (3) passage of a weak cyclone over the southern Japan Sea with a cold air outbreak on the backside of the low, and (4) passage of a moderate cyclone along the northwestern side of the Japan Sea. In winter, the Russian coastal mountains and a surface-air temperature inversion typically block cold surface continental air from the Japan Sea. Instead, the adiabatic warming of coastal mountain lee-side air results in small air-sea temperature differences. Occasional outbreaks of very cold Siberian air eliminate the continental surface-based inversion and stability, allowing very cold air to push out over the Japan Sea for 1-3 days. During these outbreaks, the 0°C surface air isotherm extends well southward of 40°N, the surface heat losses in the center of the Japan Sea can exceed 600 W m-2, and sheet clouds cover most of the Japan Sea, with individual roll clouds extending from near the Russian coast to Honshu. During December through February, 1991-2002, these strong cold-air outbreak conditions occur 39% of the time and contribute 43% of the net heat loss from the Japan Sea. The average number of strong cold-air events per winter (November-March) season is 13 (ranging from 5 to 19); the 1999/2000 winter season covered in our measurements was normal.

  10. Fluctuations of the thermal fronts off northeastern Taiwan YiChia Hsin,1

    E-print Network

    Wu, Chau-Ron

    to the seasonal reversal of the monsoonal winds. The temperature gradient is enhanced in winter and a cold dome, salt, and mass poleward from the tropical ocean and plays an important role in the global climate [Qu Kuroshio. [3] In summer, a cold dome with diameter of 100 km is frequently observed near the shelf break

  11. Initial Study of Solar Control Film in a Hotel Guest Room in Winter 

    E-print Network

    Chan, W. C.; Chen, Y.; Mak, B.; Li, D.; Huang, Y.; Xie, H.; Hou, G.

    2006-01-01

    was carried out in summer to estimate its positive effect on energy saving. There is also a paucity of experiments conducted in winter to show its negative effect in cold weather. This study carries out an experiment in hotel guest rooms in winter in order...

  12. 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 ...

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

    Microsoft Academic Search

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

    1999-01-01

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

  14. Initial Study of Solar Control Film in a Hotel Guest Room in Winter

    E-print Network

    Chan, W. C.; Chen, Y.; Mak, B.; Li, D.; Huang, Y.; Xie, H.; Hou, G.

    2006-01-01

    was carried out in summer to estimate its positive effect on energy saving. There is also a paucity of experiments conducted in winter to show its negative effect in cold weather. This study carries out an experiment in hotel guest rooms in winter in order...

  15. 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.

  16. Cold agglutination.

    PubMed

    Roelcke, D

    1989-04-01

    Autoantibodies against red cells optimally reacting at 0 degree C, ie, CA, are normally found with low titers in the serum of human adults. High-titer CA may be induced by certain infectious agents, including M pneumoniae, EBV, CMV, and rubella virus, or may develop on the basis of chronic (malignant) B cell lymphoproliferation. The main clinical manifestation of cold agglutination is AIHA. Antigens and antibodies of cold agglutination are the best characterized reaction partners of a human autoimmune process. CA may recognize I and i antigens, which are lipid- and protein-linked branched and linear N-acetyl-lactosamine chains, respectively. They are precursors of the ABH blood group antigens and are converted into H by fucosylation. An alternative substitution by sialylation creates Gd, Fl, and probably Vo/Li antigens. CA with anti-Pr and anti-Sa specificities recognize 0-glycans with immunodominant sialyl groups on glycophorins. Several Pr subspecificities can be identified by chemically modified sialyl groups on glycophorins. Because CA in chronic lymphoproliferation are monoclonal antibodies, structure-specificity-interrelations of the antibodies could be identified by primary structure analyses of the N-terminal variable regions of H and L chains and by studies on CA idiotypes. Interrelations between distinct CA specificities and particular infectious agents could explain cold agglutination as a response to receptors for the agents or to the binding sites of antibodies against the agents. Interrelations also existing between certain CA isotypes (Ig classes and L chain types) and CA specificities could be a basis for the elucidation of the enigmatic etiology of chronic (malignant) monoclonal cold agglutination. PMID:2520550

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

    NASA Astrophysics Data System (ADS)

    McGregor, Glenn R.

    2005-01-01

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

  18. Relativistic runaway ionization fronts.

    PubMed

    Luque, A

    2014-01-31

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

  19. Relativistic Runaway Ionization Fronts

    NASA Astrophysics Data System (ADS)

    Luque, A.

    2014-01-01

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

  20. 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 ...

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

    NASA Astrophysics Data System (ADS)

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

    2010-05-01

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

  2. 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...

  3. Winter precipitation change in South China in recent decades

    NASA Astrophysics Data System (ADS)

    Cai, Jingning

    2013-04-01

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

  4. 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.

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

    E-print Network

    Lee Jr., Richard E.

    (Chrysemys picta) * Corresponding author. Present address: Biology Department, Augustana Col- lege, Rock (Chrysemys picta) to increase cold hardiness in response to brief exposure to a subzero temper- ature. Winter

  6. Common cold

    PubMed Central

    2011-01-01

    Introduction Each year, children suffer up to 5 colds and adults have two to three infections, leading to time off school or work, and considerable discomfort. Most symptoms resolve within 1 week, but coughs often persist for longer. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical question: What are the effects of treatments for common cold? We searched: Medline, Embase, The Cochrane Library, and other important databases up to January 2010 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found 21 systematic reviews and RCTs that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review we present information relating to the effectiveness and safety of the following interventions: analgesics or anti-inflammatory drugs, antibiotics, antihistamines, decongestants for short-term and for long-term relief, decongestants plus antihistamines, echinacea, steam inhalation, vitamin C, and zinc (intranasal gel or lozenges). PMID:21406124

  7. Winter 2007 Practicing Medicine

    E-print Network

    Cui, Yan

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

  8. Winter Math Activities

    NSDL National Science Digital Library

    Terry Kawas

    2013-01-01

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

  9. 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....

  10. Winter 2014 Economics 471

    E-print Network

    Carter, John

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

  11. Effects of age on thermoregulatory responses during cold exposure in a non-human primate, Microcebus murinus.

    E-print Network

    46 81 18 E-Mail: terrien@mnhn.fr Running head: Aging and cold resistance in a non-human primate in response to cold could be related to an altered regulation of plasma insulin-like growth factor-1 (IGF-1 in captive animals in winter conditions. Short-term (after 2 days) and long-term (after 9 days) cold

  12. Cold Protection of Landscape Plants1 Sydney Park Brown, Dewayne L. Ingram, and Thomas H. Yeager2

    E-print Network

    Watson, Craig A.

    ENH1 Cold Protection of Landscape Plants1 Sydney Park Brown, Dewayne L. Ingram, and Thomas H/IFAS Extension. Winter temperatures in Florida are frequently low enough to cause cold injury to tropical plants may be more susceptible to cold injury. Types of Freezes - Radiational and Advective Freezes can

  13. 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

  14. Order parameter equations for front transitions: Nonuniformly curved fronts

    NASA Astrophysics Data System (ADS)

    Hagberg, Aric; Meron, Ehud

    1998-11-01

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

  15. Gulf Stream thermal fronts detected by synthetic aperture radar

    NASA Astrophysics Data System (ADS)

    Xie, Tao; Perrie, William; Chen, Wei

    2010-03-01

    Our purpose is to detect ocean surface features, specifically oceanic thermal fronts, through analysis of SAR (synthetic aperture radar)-derived wind stress fields. Fine-resolution measurements of near-surface wind speeds over the Gulf Stream region of the Northwest Atlantic were made using SAR images collected by RADARSAT-2. Linear statistical relationships between the wind stress curl and divergence to the crosswind and downwind components of the SST gradient field were used to derive a new method for detecting Gulf Stream thermal fronts from Synthetic Aperture Radar (SAR) imagery. In particular, sea surface temperature front features, as suggested by corresponding AVHRR and MODIS images, are evident in both of the wind stress curl and divergence fields. The importance of this methodology is that clouds are often present in the Northwest Atlantic in autumn and winter months and they obscure AVHRR and MODIS images, whereas SAR can penetrate clouds.

  16. 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

  17. American woodcock winter distribution and fidelity to wintering areas

    USGS Publications Warehouse

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

    1990-01-01

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

  18. 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

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

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

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

  20. Light-front vacuum

    NASA Astrophysics Data System (ADS)

    Herrmann, Marc; Polyzou, W. N.

    2015-04-01

    The purpose of this work is to understand the relation between the trivial vacuum in light-front field theory and the nontrivial vacuum in canonical representations of quantum field theory and the role of zero-modes in this relation. The role of the underlying field algebra in the definition of the vacuum is exploited to understand these relations. The trivial vacuum defined by an annihilation operator defines a linear functional on the algebra of fields restricted to a light front. This is extended to a linear functional on the algebra of local fields. The extension defines a unitary mapping between the physical representation of the local algebra and a sub-algebra of the light-front Fock algebra. The dynamics appears in the mapping and the structure of the sub-algebra. This correspondence provides a formulation of locality and Poincaré invariance on the light-front Fock space. Zero modes do not appear in the final mapping, but may be needed in the construction of the mapping using a local Lagrangian.

  1. The Dynamical Subtropical Front

    NASA Astrophysics Data System (ADS)

    Graham, Robert M.; Boer, Agatha M.

    2013-10-01

    The Southern Ocean Subtropical Front (STF) is thought to play a key role in the global climate system. Theory suggests that the latitude of the STF regulates the volume of saline Agulhas Leakage into the Atlantic Ocean from the Indian. Here we use satellite sea surface temperature (SST) and sea surface height (SSH) data to study the physical characteristics of the STF water mass boundary. We find that the strong currents in this region do not align with the surface water mass boundary. Therefore, we provide a new climatology for these currents which we define as the Dynamical STF (DSTF). The DSTF is the eastward extension of the western boundary current in each basin and is characterized by strong SST and SSH gradients and no seasonal cycle. At the center of each basin it merges with the Sub-Antarctic Front. On the eastern side of basins, the STF surface water mass boundary coincides with a separate region of multiple SST fronts. We call this the Subtropical Frontal Zone (STFZ). The fronts in the STFZ have a large seasonal cycle and no SSH signature. Despite lying close to the same water mass boundary, the DSTF and STFZ are completely unrelated. We therefore suggest the term STF only be used when referring to the surface water mass boundary. When studying the strong currents on the western side of basins the term DSTF is more relevant and, similarly, the term STFZ better describes the region of enhanced SST gradients towards the east.

  2. Long-term variability of cold surges in Korea

    NASA Astrophysics Data System (ADS)

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

    2014-08-01

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

  3. Bank erosion in cold regions

    SciTech Connect

    Gatto, L.W. (Army Cold Regions Research and Engineering Lab., Hanover, NH (United States). Geological Sciences Branch)

    1993-03-01

    River and lake bank erosion is caused by multiple processes and influenced by many conditions that interact in complex ways. Their importance will vary spatially and temporally due in large part to regional and seasonal differences in climate, hydrology and soils. In cold areas, these normally complex interactions are further complicated because the same process or condition may cause erosion at one time and prevent erosion at another. Bank sediments when frozen may be more resistant to erosion than when unfrozen. However, during the process of freezing, soil structure can be disrupted and sediment pore water can be drawn to the freezing zone within the soil; ice formation may make bank sediment more susceptible to erosion during spring thaw. Ice that has been forced onto and piled upon a shore by wind or thermal expansion can cause considerable localized damage and yet can also protect shores against winter waves and nearshore currents. Ice push can form sediment ramparts that protect the toe of a bank. Spray from winds and waves can freeze to banks, covering them with a protective layer of ice. When river or lake water levels are high enough, however, ice can erode banks by shoving, gouging and disrupting bank sediment. This paper reviews the state of knowledge regarding the importance of cold regions factors in determining the erodibility and erosion of bank sediments. Ongoing investigations to improve methods of erosion prediction in cold climates will also be detailed.

  4. 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 ...

  5. Winter Weather Checklists

    MedlinePLUS

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

  6. In Depth Winter Weather

    NSDL National Science Digital Library

    2012-01-01

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

  7. Cold Atoms

    NASA Astrophysics Data System (ADS)

    Bellac, Michel Le

    2014-11-01

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

  8. Cold fusion

    SciTech Connect

    Bush, R.T. (California State Polytechnic Univ., Physics Dept., Pomona, CA (US))

    1991-03-01

    The transmission resonance model (TRM) is combined with some electrochemistry of the cathode surface and found to provide a good fit to new data on excess heat. For the first time, a model for cold fusion not only fits calorimetric data but also predicts optimal trigger points. This suggests that the model is meaningful and that the excess heat phenomenon claimed by Fleischmann and Pons is genuine. A crucial role is suggested for the overpotential and, in particular, for the concentration overpotential, i.e., the hydrogen overvoltage. Self-similar geometry, or scale invariance, i.e., a fractal nature, is revealed by the relative excess power function. Heat bursts are predicted with a scale invariance in time, suggesting a possible link between the TRM and chaos theory. The model describes a near-surface phenomenon with an estimated excess power yield of {approximately}1 kW/cm{sup 3} Pd, as compared to 50 W/cm{sup 3} of reactor core for a good fission reactor. Transmission resonance-induced nuclear transmutation, a new type of nuclear reaction, is strongly suggested with two types emphasized: transmission resonance-induced neutron transfer reactions yielding essentially the same end result as Teller's hypothesized catalytic neutron transfer and a three-body reaction promoted by standing de Broglie waves. In this paper suggestions for the anomalous production of heat, particles, and radiation are given.

  9. Cold confusion

    SciTech Connect

    Chapline, G.

    1989-07-01

    On March 23 two chemists, Martin Fleischmann and Stanley Pons startled the world with a press conference at the University of Utah where they announced that they had achieved nuclear fusion at room temperatures. As evidence they cited the production of ''excess'' amounts of heat in an electrochemical apparatus and observation of neutron production. While the production of heat in a chemical apparatus is not in itself unusual the observation of neutrons is certainly extraordinary. As it turned out, though, careful measurements of the neutron production in electrochemical apparatus similar to that used by Fleischmann and Pons carried out at dozens of other laboratories has shown that the neutron production fails by many orders of magnitude to support the assertion by Fleischmann and Pons that their discovery represents a new and cheap source of fusion power. In particular, independent measurements of the neutron production rate suggest that the actual rate of fusion energy production probably does not exceed 1 trillionth of a watt. This paper discusses the feasibility that cold fusion is actually being achieved. 7 refs.

  10. Winter ecology of Arctic charr ( Salvelinus alpinus ) and brown trout ( Salmo trutta ) in a subarctic lake, Norway

    Microsoft Academic Search

    Per-Arne Amundsen; Rune Knudsen

    2009-01-01

    We studied habitat choice, diet, food consumption and somatic growth of Arctic charr (Salvelinus alpinus) and brown trout (Salmo trutta) during the ice-covered winter period of a subarctic lake in northern Norway. Both Arctic charr and brown trout predominantly\\u000a used the littoral zone during winter time. Despite very cold winter conditions (water temperature <1°C) and poor light conditions,\\u000a both fish

  11. Recent research advances in cold-formed steel structures

    Microsoft Academic Search

    J. M Davies

    2000-01-01

    Recent developments in the practical utilisation of cold-formed sections in building construction have taken place on three related fronts. There have been significant developments in the technology which result in more complex shapes with a higher yield stress so that cold-formed sections represent a particularly high-tech form of constructional steelwork. Developments in technology would be of little consequence unless there

  12. Warmest winter in history

    NSDL National Science Digital Library

    Payne, Laura X.

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

  13. 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...

  14. 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.

  15. At the front

    Microsoft Academic Search

    Paul Hainsworth

    1996-01-01

    Le Pen. Biographie. By G. BRESSON and C. LIONET. Paris: Seuil, 1994. Pp.476. FF140 (paper). ISBN 2–02–014063–2.A Small City in France: A Socialist Mayor Confronts Neofascism. By F. GASPARD (translated by A. Goldhammer). Cambridge, MA and London: Harvard University Press, 1995. Pp.xi + 194, index. £25.95\\/$38.95 (cloth); £9.95\\/$19.25 (paper). ISBN 0–674–81096–1 and ?81097?X.The National Front and French Politics: The Resistible

  16. Confronting the front

    Microsoft Academic Search

    Paul Hainsworth

    1997-01-01

    Ardid C. and Davin L., Ascenseur pour les Fachos (Plein Sud, 1995), 240pp., 120F., ISBN 2 87764 432 4Aubry, M. and Duhamel O., Petit dictionnaire pour lutter contre l'extrême?droite (Seuil, 1995), 268pp., 79F., ISBN 2 02 028833 8Bayle M., Le Front National: ça n'arrive pas qu'aux autres (Plein Sud, 1995), 215pp., 120F., ISBN 2 87764 431 6Maréchal S., Ni droite

  17. HYPOTHERMIA Surviving the Cold

    E-print Network

    Machel, Hans

    HYPOTHERMIA Surviving the Cold www.WorkSafebc.com #12;About the WCB Preventing on-the-job injury-HELP) toll-free in British Columbia. #12;1 Introduction Working in a cold environment ­ whether it be cold weather, cold water, or an indoor freezer ­ is part of the job for many British Columbia workers. One

  18. EFFECTS OF CLIMATE CHANGE ON VEGETATION AND ECOSYSTEM SERVICES IN THE COLORADO FRONT RANGE

    EPA Science Inventory

    If climate change leads to an extended growing season and somewhat wetter winters in the Front Range of Colorado, then a new time period of resource availability will be created. Non-native vegetation whose native lands possessed climates similar to the ?new conditions? may be...

  19. Quantifying Mountain Front Recharge Using Isotopic Tracers

    NASA Astrophysics Data System (ADS)

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

    2005-05-01

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

  20. 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

  1. Seasonal changes in the cold hardiness of the two-spotted spider mite females (Acari: Tetranychidae).

    PubMed

    Khodayari, S; Colinet, H; Moharramipour, S; Renault, D

    2013-12-01

    The twospotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae) is an important agricultural pest. Population dynamics and pest outbreaks highly depend on the overwintering success of the mite specimens; therefore, it is necessary to assess winter survival dynamics of this pest. Seasonal changes in supercooling point (SCP) and acute cold tolerance (2-h exposure at -5, -10, -15, -20, -23, or -25°C) were assessed in field-collected females during the winter in 2010-2011 in Iran. The SCP values varied from a minimum of -30.5°C (January 2011) to a maximum of -12.6°C (April 2011). Significant differences were recorded in the SCP distribution patterns between autumn- and winter-sampled females, depicting the acquisition of cold hardiness over the winter. The mean ambient air temperature was the lowest in January (4°C), when the females showed the highest supercooling ability. Correlated patterns between monthly temperatures and acute cold tolerance also were found. At -20°C, the survival of the mites was very low (10%) when they were sampled in October 2010; whereas it was high (97.5%) in January 2011, before decreasing to 5% in April 2011. The present data show that T. urticae females are chill tolerant and capable of adjusting their cold tolerance over the winter season. Acute cold tolerance (-15 and -20°C) and SCP represent valuable metrics that can be used for predicting the seasonal changes of the cold hardiness of T. urticae females. PMID:24252290

  2. Climatological characteristics of fronts in the western North Pacific based on surface weather charts

    NASA Astrophysics Data System (ADS)

    Utsumi, Nobuyuki; Kim, Hyungjun; Seto, Shinta; Kanae, Shinjiro; Oki, Taikan

    2014-08-01

    Composite front climatology in the western North Pacific is determined using a newly developed 1.0° gridded data set. Here we propose a research strategy for determining the spatiotemporal distribution of fronts using weather chart images published by the Japan Meteorological Agency, one of the major data providers in the region. A preliminarily investigation of the internal data characteristics for the period of 2000-2010 is undertaken, and the final 4 years of data are used for an analysis of front climatology to avoid the effect of any spurious trends. This enables in-depth analyses to be conducted, which have not previously been possible in the region, including the composites of cross-sectional patterns for the thermal fields and precipitation near fronts, front length seasonality, and the significance of the thermal gradient near the fronts, in addition to determining the frontal frequency and spatial distribution of frontal precipitation. Pixel-wise analysis reveals that 56% of the local precipitation maximum is located on the warm side of a cold front caused by less tilted upward motion on the warm side, with the intrusion of the upper level cold dry air into the warm side. This new data set also enables a further analysis of the occluded fronts, which are not correctly distinguished in the existing objective detection method.

  3. Seasonal variations in the responses of glycolytic intermediates of human erythrocytes to acute cold exposure

    NASA Astrophysics Data System (ADS)

    Ohno, H.; Yahata, T.; Yamashita, K.; Kuroshima, A.

    1988-03-01

    Seven male students were studied to observe the effects of acute cold exposure (at 10°C for 60 min) on erythrocyte concentrations of glycolytic intermediates in summer and in winter. The subjects shivered slightly but frankly in both experiments. Significant decreases were observed in the concentrations of pyruvate and lactate during body cooling in summer, but not in winter. The lactate concentration remained significantly reduced 15 min after cold exposure. After 60 min of cold exposure in summer, a negative crossover point appeared to exist between phosphoenolpyruvate and pyruvate and erythrocyte pyruvate kinase activity showed a significant decrease. No seasonal difference was observed in the initial control values of the intermediates measured. From these results and the fact that glucose, pyruvate and lactate are evenly distributed between erythrocytes and plasma, it is likely that erythrocytes and skeletal muscles need less fuel substrate, glucose during cold exposure in winter than in summer, suggesting that an increased economy of energy for homeostasis is achieved.

  4. Winter Storm Lesson Plan

    NSDL National Science Digital Library

    Tasia S.

    2010-09-23

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

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

    PubMed

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

    2012-01-01

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

  6. Winter Storm (weather)

    NSDL National Science Digital Library

    Aubree Miller

    2009-09-28

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

  7. ANNUAL WINTER SCHOOLANNUAL WINTER SCHOOL Petersburg Nuclear Physics Institute

    E-print Network

    Titov, Anatoly

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

  8. HVAC design considerations for cold climates

    SciTech Connect

    Armstrong, R.S. (RSA Engineering Inc., Anchorage, AK (United States))

    1993-09-01

    The design of heating, ventilating and air-conditioning (HVAC) systems in cold climate areas requires modifications to the standard designs used in more temperate climates. While most of the US experiences freezing temperatures at least once during the winter months, certain areas experience several months of extended cold. No single location in the US experiences these extended cold conditions more than Alaska. While most areas in the continental US will not require modifications to standard design guidelines, many design modifications commonly used in the Arctic regions of Alaska and Canada can also be applied to any cold climate area in the continental US. The geographic area of Alaska is about one-third the size of the continental US. Climatic extremes range from Ketchikan with 6.697 heating degree days (at 55[degree]21 minutes N latitude) to Barrow with 20,341 heating degree days (at 71[degree]18 minutes N latitude), according to the Arctic Environmental Information and Data Center. The suggestions in this article are a compilation of general approaches the authors used to address the challenge of cold climate design. Of course, each detail design must be adapted to the specific climate and application at hand.

  9. Study Abroad Winter Service Program

    E-print Network

    Liskiewicz, Maciej

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

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

    Microsoft Academic Search

    V. V. Kondrat’eva; O. V. Shelepova

    2010-01-01

    The dynamics of cytokinin content and the total protein and nonprotein forms of nitrogen in tissues of wintering organs of\\u000a clary sage Salvia sclarea L. and cinquefoil Potentilla alba L. in abnormally cold (2005–2006 years) and abnormally warm (2006–2007 years) winters in Moscow have been studied. A direct\\u000a correlation between the content of total cytokinins and the total and protein

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

    Microsoft Academic Search

    CECILIA KULLBERG

    1998-01-01

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

  12. Polar vortex conditions during the 1995–96 Arctic Winter: MLS CLO and HNO 3

    Microsoft Academic Search

    M. L. Santee; G. L. Manney; W. G. Read; L. Froidevaux; J. W. Waters

    1996-01-01

    Microwave Limb Sounder (MLS) measure- ments of lower stratospheric C10 and HNOa during the 1995-96 Arctic winter are presented. The 1995-96 Arc- tic winter was both colder and more persistently cold than usual, leading to an enhancement in lower strato- spheric C10 of greater magnitude, vertical extent, and duration than previously observed in the Arctic. Vortex concentrations of HNOa in

  13. 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.

  14. Cross-equatorial influences of a South American cold surge on the development of two eastern North Pacific tropical cyclones 

    E-print Network

    Millier, Vicki Anne

    1989-01-01

    case study of such an event. In late May 1979 a severe cold front passed over South America. On the mornings of 31 May and 1 June I'our states in Brazil experienced the worst freeze since 1975. Simultaneously, two tropical cyclones developed oif... Brazil and was the worst cold surge experienced in Brazil since 1975. ' Fortune and Kousky (1983) studied this cold front (Fig. 2) and found that the strong cold surge was the result of the superposition of a shortwave trough on a longwave trough...

  15. Occurrence of large temperature inversion in the thermohaline frontal zone at the Yellow Sea entrance in winter and its relation to advection

    NASA Astrophysics Data System (ADS)

    Lie, Heung-Jae; Cho, Cheol-Ho; Jung, Kyung Tae

    2015-01-01

    inversion (higher temperature at a deeper depth) in winter and its relation to advection were investigated by analyzing both conductivity-temperature-depth data in the southern Yellow Sea (YS) and northwestern East China Sea during the winter of 2002-2003 and time series data of temperature, salinity, and currents at a buoy station at the YS entrance. Significant temperature inversions occur predominantly along the thermohaline front at the YS entrance where the Cheju Warm Current Water (CWCW) and the cold coastal waters meet. In February 2003, on the northern frontal zone along 34°N where isotherms and isohalines declined downward to the north, particularly large inversions with temperature differences of larger than 2.0°C were observed to occur more in troughs than in the crests of the wave-like frontal meander where the cold Korean coastal water (KCW) advances farther southward. The inversion persisted until mid-April at the buoy station in the frontal zone, and both temperature and salinity showed simultaneous variations in the same manner. During episodic occurrences of large inversions, temperature and salinity decreased sharply in the upper layer, but increased concurrently in the lower layer. These episodic inversions were found to be closely related to the westward advection of the KCW in the upper layer and the northward advection of the CWCW in the lower layer. It is considered that these advections may play an important role in maintaining baroclinicity in the northern frontal zone, which is responsible for driving the westward transversal flow across the YS entrance.

  16. 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…

  17. 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…

  18. Lightning Protection against Winter Lightning

    Microsoft Academic Search

    Hitoshi Sugimoto

    2007-01-01

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

  19. a Climatology of Extreme Minimum Winter Temperatures in Ohio

    NASA Astrophysics Data System (ADS)

    Edgell, Dennis Joe

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

  20. 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…

  1. winter 2015 Health Informatics

    E-print Network

    California at Davis, University of

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

  2. Physical Oceanography Winter 2013

    E-print Network

    Thompson, Andrew

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

  3. GRAND RIVER Winter 2014

    E-print Network

    Thompson, Michael

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

  4. Humanities 1 Winter 2013

    E-print Network

    Blanco, Philip R.

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

  5. WINTER 2014 Sustainability and

    E-print Network

    Stephens, Graeme L.

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

  6. Announcement Cryptography { Winter 2001

    E-print Network

    deYoung, Brad

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

  7. WINTER UNIVERSIADE CONFERENCE 2013

    E-print Network

    Di Pillo, Gianni

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

  8. 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 - ...

  9. Identifying Lagrangian fronts with favourable fishery conditions

    NASA Astrophysics Data System (ADS)

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

    2014-08-01

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

  10. FalllWinter CELEBRATE WOMEN, the Women's Health Program at the UConn Health Center, recognizes

    E-print Network

    Holsinger, Kent

    FalllWinter 2002 #12;CELEBRATE WOMEN, the Women's Health Program at the UConn Health Center Women also offers health seminars, health screenings, and front-line information on women's health.celebrate.uchc.edu. Celebrate WOmen also offers a FREE women's health membership program. \\fJ UConn Health Center #12

  11. Zooplankton data report: Winter MIZEX, 1987

    SciTech Connect

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

    1988-12-01

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

  12. FACILITY 209, SINGLESTORY DUPLEX, FRONT OBLIQUE VIEW OF FRONT FROM ...

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

    FACILITY 209, SINGLE-STORY DUPLEX, FRONT OBLIQUE VIEW OF FRONT FROM CENTER DRIVE, FACING SW. - U.S. Naval Base, Pearl Harbor, Housing Area 1, Single Story Duplex Type, Bounded by Kamehameha Highway, Plantation Drive, South Avenue, Pearl City, Honolulu County, HI

  13. Turbulent statistics in the vicinity of an SST front: A north wind case, FASINEX February 16, 1986

    NASA Technical Reports Server (NTRS)

    Stage, Steven A.; Herbster, Chris

    1990-01-01

    The technique of boxcar variances and covariances is used to examine NCAR Electra data from FASINEX (Frontal Air-Sea Interaction EXperiment). This technique was developed to examine changes in turbulent fluxes near a sea surface temperature (SST) front. The results demonstrate the influence of the SST front on the MABL (Marine Atmospheric Boundary Layer). Data shown are for February 16, 1986, when the winds blew from over cold water to warm. The front directly produced horizontal variability in the turbulence. The front also induced a secondary circulation which further modified the turbulence.

  14. Titanium Cold Spray Coatings

    Microsoft Academic Search

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

    2010-01-01

    Titanium Cold Spray Coatings Cold Spray is an emerging technology used for the deposition of coatings for many industries including aerospace. This technique allows the deposition of metallic materials at low temper-atures below their melting point. The aim of this research was to develop a test technique that can measure the degree to which a cold spray coating achieves mechanical

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

    PubMed

    Kondrat'eva, V V; Shelepova, O V

    2010-01-01

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

  16. The Physics Front

    NSDL National Science Digital Library

    2012-06-22

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

  17. The Physics Front

    NSDL National Science Digital Library

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

  18. 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…

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

    PubMed

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

    2012-01-01

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

  20. Winter Storm Activity

    NSDL National Science Digital Library

    Mikel Barbieri

    2012-02-13

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

  1. Winter weather activity

    NSDL National Science Digital Library

    Whitney Frankovic

    2009-09-28

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

  2. Winter Storm Activity

    NSDL National Science Digital Library

    FerraraTechClassroom

    2012-02-06

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

  3. Winter Storm Activity

    NSDL National Science Digital Library

    Kirsten Butcher

    2008-09-26

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

  4. Storm Winter Activity

    NSDL National Science Digital Library

    KateOlsen58

    2009-09-28

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

  5. Winter Storm Warning

    NSDL National Science Digital Library

    2009-09-28

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

  6. Al's Winter Storm Activity

    NSDL National Science Digital Library

    Al

    2010-02-22

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

  7. Winter Storm Activity

    NSDL National Science Digital Library

    Xuan

    2010-02-22

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

  8. 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.

  9. Staying Warm Winter Experiments

    NSDL National Science Digital Library

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

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

    E-print Network

    Maxwell, Bruce D.

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

  11. Asymmetric counterpropagating fronts without flow

    NASA Astrophysics Data System (ADS)

    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.

  12. Snapshot of the Physics Front

    NSDL National Science Digital Library

    Ezrailson, Cathy

    The Physics Front collection is the physics and physical science online library developed for pre-college teachers within the ComPADRE Digital Library Pathways Project. The Physics Front serves a broad spectrum of users that include new and crossover physics teachers, pre-service as well as in-service teachers of physical science and physics for grades K through 12, teacher preparation instructors in universities as well as students of physics and physical science. Participation in The Physics Front collection also extends to physics departments involved in the preparation of pre-service teachers and the support of in-service teachers and their students.

  13. Wave-front estimation from wave-front slope measurements

    Microsoft Academic Search

    W. H. Southwell

    1980-01-01

    The problem of wave-front estimation from wave-front slope measurements has been examined from a least-squares curve fitting model point of view. It is shown that the slope measurement sampling geometry influences the model selection for the phase estimation. Successive over-relax- ation (SOR) is employed to numerically solve the exact zonal phase estimation problem. A new zonal phase gradient model is

  14. 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

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

    PubMed

    Straume, Aksel; Johnsson, Anders; Oftedal, Gunnhild

    2008-01-01

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

  16. 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 ...

  17. Arctic winter 2005: Implications for stratospheric ozone loss and climate change

    Microsoft Academic Search

    M. Rex; R. J. Salawitch; H. Deckelmann; P. von der Gathen; N. R. P. Harris; M. P. Chipperfield; B. Naujokat; E. Reimer; M. Allaart; S. B. Andersen; R. Bevilacqua; G. O. Braathen; H. Claude; J. Davies; H. De Backer; H. Dier; V. Dorokhov; H. Fast; M. Gerding; S. Godin-Beekmann; K. Hoppel; B. Johnson; E. Kyrö; Z. Litynska; D. Moore; H. Nakane; M. C. Parrondo; A. D. Risley; P. Skrivankova; R. Stübi; P. Viatte; V. Yushkov; C. Zerefos

    2006-01-01

    The Arctic polar vortex exhibited widespread regions of low temperatures during the winter of 2005, resulting in significant ozone depletion by chlorine and bromine species. We show that chemical loss of column ozone (DeltaO3) and the volume of Arctic vortex air cold enough to support the existence of polar stratospheric clouds (VPSC) both exceed levels found for any other Arctic

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  19. The ABCs of Front Management

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    PubMed

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

    2010-10-01

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

  1. 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.

  2. 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)

  3. 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.

  4. winter storm activity

    NSDL National Science Digital Library

    Miss Prested

    2010-05-26

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

  5. Chaffinch and Winter Wren

    NSDL National Science Digital Library

    2009-01-01

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

  6. Effect of auxin physiological analogues on rapeseed (Brassica napus) cold hardening, seed yield and quality.

    PubMed

    Gavelien?, Virgilija; Novickien?, Leonida; Pakalniškyt?, Lina

    2013-03-01

    The effect of the auxin physiological analogues analogues 1-[2-chloroethoxycarbonylmethyl]-4-naphthalenesulfonic acid calcium salt (TA-12) and 1-[2-dimethylaminoethoxicarbonylmethyl]naphthalene chlormethylate (TA-14) TA-14 on different winter rapeseed cultivars were studied with regard to their autumnal growth, cold hardening, accumulation of the stress-protective metabolites proline and saccharide in plant organs: apical bud and root collum, winter survival and productivity formation. The test cultivars were the very early 'Libea' medium-resistant to wintering, the medium-early 'Sunday' resistant to wintering, the medium-early 'Valesca' less than medium resistant to wintering, and the early 'Hornet' (hybrid) tolerant to stress growth conditions. During the period of cold hardening in natural field conditions, the test compounds TA-12 (2 mM) and TA-14 (4 mM), applied to different winter rapeseed cultivars at the 4th-5th leaf stage, stimulate accumulation proline and saccharides (sucrose and glucose) in the root collum and apical bud tissues, influence plants acclimation to cold, overwintering and productivity formation. Compounds TA-12 and especially TA-14 produced a stable effect on seed and crude fat yield in cvs. 'Hornet', 'Sunday' and 'Libea'. The genotypic peculiarities of a cultivar and the meteorological conditions of the plant vegetation period were the factors that mostly determined fatty acid content in seed oil. PMID:23086232

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

    PubMed

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

    2015-03-01

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

  8. 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…

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

    PubMed

    Friedman, I; Smith, G I

    1972-05-19

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

  10. Spirit's Winter Work Site

    NASA Technical Reports Server (NTRS)

    2006-01-01

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

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

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

  11. Characterization of multiple cold induced genes from Ammopiptanthus mongolicus and functional analyses of gene AmEBP1.

    PubMed

    Cao, Pengxiu; Song, Jian; Zhou, Chunjiang; Weng, Manli; Liu, Jing; Wang, Fuxin; Zhao, Feng; Feng, Dianqi; Wang, Bin

    2009-03-01

    In comparison to herbaceous plants, studies of cold responsive genes and cold signaling in woody perennials are limited. Since most woody plants have evolved freezing tolerance (FT) in winter, together with similar lignified structures and winter adaptive mechanisms, it is more likely to find cold resistant genes in woody plants growing in temperate and arctic regions. In this study, Ammopiptanthus mongolicus, an evergreen, broadleaf and leguminous shrub was selected as a model to study cold tolerance in woody plants. Thirteen cold up-regulated cDNAs (including eight full-length cDNAs and five partial cDNAs) were cloned from A. mongolicus. One of these genes, AmEBP1, confers enhanced cold tolerance to E. coli and obvious increased freezing survival to Arabidopsis. In transgenic Arabidopsis expressing AmEBP1, transcript levels of some downstream genes in cold signaling exhibit increased accumulation upon cold treatment. Together with structural information, sub-cellular location, and promoter analysis data, it is suggested that AmEBP1 enhances plants cold tolerance by accelerating ribosome biogenesis and the concomitant translation of cold induced transcription factors and downstream protective proteins under cold stress. PMID:19067182

  12. Is It a Cold or the Flu? Symptoms Cold Flu

    E-print Network

    Bandettini, Peter A.

    Is It a Cold or the Flu? Symptoms Cold Flu Fever Rare Usual; high (100°F to 102°F, occasionally with a cold Annual vaccination; antiviral medicines--see your doctor Complications Sinus congestion Middle ear

  13. WINTER 2013 Ohio State launches

    E-print Network

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

  14. Instructor: N. Jones Winter 2012

    E-print Network

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

  15. Seasonal trends in acclimatization to cold in the Queensland fruit fly ( Dacus tryoni , Diptera) and their prediction by means of a physiological model fed with climatological data

    Microsoft Academic Search

    A. Meats

    1976-01-01

    This paper demonstrates the predictability and significance of changes in the temperature threshold for cold-torpor and in the threshold for survival at sub-zero temperatures in two contrasting types of climate. Both thresholds alter on a seasonal basis in both types of climate and it is observed that temperatures prevailing in autumn cause acclimatization for winter long before winter arrives.

  16. Cold-adapted archaea

    Microsoft Academic Search

    Ricardo Cavicchioli

    2006-01-01

    Many archaea are extremophiles. They thrive at high temperatures, at high pressure and in concentrated acidic environments. Nevertheless, the largest proportion and greatest diversity of archaea exist in cold environments. Most of the Earth's biosphere is cold, and archaea represent a significant fraction of the biomass. Although psychrophilic archaea have long been the neglected majority, the study of these microorganisms

  17. Ultra-Cold Molecules

    Microsoft Academic Search

    A. Fioretti; M. Fazzi; M. Mazzoni; T. Ban; C. Gabbanini

    2004-01-01

    In this paper we overview recent results on the formation of translationally cold molecules. While there are some methods relying on direct cooling of molecules, we shall concentrate on the photoassociation technique that starts from laser-cooled atoms. The detection methods for the ultra-cold molecules will be presented together with a report on the trapping techniques. The treatment is mainly focused

  18. Cold Air Damming

    NSDL National Science Digital Library

    2014-09-14

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

  19. 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.

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

    Microsoft Academic Search

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

    2005-01-01

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

  1. The protection of wheat plasma membrane under cold stress by glycine betaine overproduction

    Microsoft Academic Search

    X.-Y. Zhang; C. Liang; G.-P. Wang; Y. Luo; W. Wang

    2010-01-01

    We aimed to study the protection of wheat plasma membrane (PM) under cold stress (0–2 °C) by the overaccumulation of glycine\\u000a betaine (GB). For this, we used wild-type winter wheat (Triticum aestivum L.) cv. Shi 4185 (WT) and 3 transgenic lines (T1, T4, and T6) expressing the BADH gene isolated from Atriplex hortensis L. Under cold stress, the transgenic lines

  2. Solar forcing of winter climate variability in the Northern Hemisphere

    NASA Astrophysics Data System (ADS)

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

    2011-11-01

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

  3. A Winter's Tale

    NSDL National Science Digital Library

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

  4. 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.

  5. 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.

  6. Prescription Drugs and Cold Medicines

    MedlinePLUS

    ... Drugs of Abuse » Prescription Drugs & Cold Medicines Prescription Drugs & Cold Medicines Email Facebook Twitter What is Prescription Drug Abuse: Some medications have psychoactive (mind-altering) properties ...

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

    E-print Network

    Lotze, Heike K.

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

  8. Global transcriptome profiles of Camellia sinensis during cold acclimation

    PubMed Central

    2013-01-01

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

  9. Distribution and cycling of total organic carbon across the Almeria-Oran Front in the Mediterranean Sea: Implications for carbon cycling in the western basin

    Microsoft Academic Search

    Richard Sempéré; Evgeny Dafner; France Van Wambeke; Dominique Lefèvre; Cédric Magen; Sophie Allègre; Flavienne Bruyant; Micheline Bianchi; Louis Prieur

    2003-01-01

    The dynamics of the total organic carbon (TOC) pool were studied during winter 1997–1998 in the Almeria-Oran jet-front (AOF) system. This system includes the modified Atlantic Jet, which spreads into the Mediterranean Sea from the Gibraltar Strait, its associated gyre, and the front between the Mediterranean and Atlantic waters. We determined TOC concentrations, bacterial production (BP), and primary production (PP)

  10. Distribution and cycling of total organic carbon across the Almeria-Oran Front in the Mediterranean Sea: Implications for carbon cycling in the western basin

    Microsoft Academic Search

    Richard Sempéré; Evgeny Dafner; France Van Wambeke; Dominique Lefèvre; Cédric Magen; Sophie Allègre; Flavienne Bruyant; Micheline Bianchi; Louis Prieur

    2003-01-01

    The dynamics of the total organic carbon (TOC) pool were studied during winter 1997-1998 in the Almeria-Oran jet-front (AOF) system. This system includes the modified Atlantic Jet, which spreads into the Mediterranean Sea from the Gibraltar Strait, its associated gyre, and the front between the Mediterranean and Atlantic waters. We determined TOC concentrations, bacterial production (BP), and primary production (PP)

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

    PubMed Central

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

    2004-01-01

    In temperate climates, the prolonged cold temperature of winter serves as a seasonal landmark for winter-annual and biennial plants. In these plants, flowering is blocked before winter. In Arabidopsis thaliana, natural variation in the FRIGIDA (FRI) gene is a major determinate of the rapid-cycling vs. winter-annual flowering habits. In winter-annual accessions of Arabidopsis, FRI activity blocks flowering through the up-regulation of the floral inhibitor FLOWERING LOCUS C (FLC). Most rapid-flowering accessions, in contrast, contain null alleles of FRI. By performing a mutant screen in a winter-annual strain, we have identified a locus, FRIGIDA LIKE 1 (FRL1), that is specifically required for the up-regulation of FLC by FRI. Cloning of FRL1 revealed a gene with a predicted protein sequence that is 23% identical to FRI. Despite sequence similarity, FRI and FRL1 do not have redundant functions. FRI and FRL1 belong to a seven-member gene family in Arabidopsis, and FRI, FRL1, and at least one additional family member, FRIGIDA LIKE 2 (FRL2), are in a clade of this family that is required for the winter-annual habit in Arabidopsis. PMID:14973192

  12. 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.

  13. 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.

  14. 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.

  15. INFLUENCE OF CYTOSKELETAL AGENTS ON THE RESPIRATORY ELECTRON TRANSPORT PATHWAYS IN THE CELLS OF WINTER WHEAT LEAVES

    Microsoft Academic Search

    Y. R. Abdrakhimova; L. P. Khokhlova; A. F. Abdrakhmanova; F. A. Abdrakhimov

    2000-01-01

    The effects of actin and tubulin polymerization inhibitors on the respiratory electron transport pathway activities were investigated using abscisic acid (ABA)- and cold-treated winter wheat seedling leaves. In unstressed control plants, cytochalasin B (15?m) decreased the capacity of the cytochrome pathway, but stimulated the cyanide-resistant pathway, whereas oryzalin (15?m) produced the opposite effects. Cold hardening (3°C for 7 days) and

  16. Cold Sores (HSV-1)

    MedlinePLUS

    ... anywhere on the body, including the genital area. Genital herpes isn't typically caused by HSV-1; it's ... Parents MORE ON THIS TOPIC Can You Get Genital Herpes From a Cold Sore? Mononucleosis Genital Herpes Tips ...

  17. 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? ...

  18. 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.

  19. Reaction front formation in contaminant plumes

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  20. Transmission of colds

    Microsoft Academic Search

    Diane E. Pappas; J. Owen Hendley

    Rhinorrhea, nasal congestion, and sore throat herald the beginning of the cold season for both children and adults. Although\\u000a the common cold is a self-limited infection, there are no effective treatments presently available and complications, missed\\u000a time from work and school, and overall discomfort are not insignificant. Understanding how infections are transmitted may\\u000a lead to interventions to reduce rates of

  1. 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.

  2. The Challenge of Winter Backpacking.

    ERIC Educational Resources Information Center

    Cavanaugh, Michael; Mapes, Alan

    1981-01-01

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

  3. 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 ...

  4. Dispatch from the front line

    Microsoft Academic Search

    J. G. Manning

    1996-01-01

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

  5. 48 Los Alamos Science Number 24 1996 In the midst of a cold Russian

    E-print Network

    48 Los Alamos Science Number 24 1996 In the midst of a cold Russian winter, these Russian Fowler, Sakharov was seeking a means to achieve thermonuclear fusion, and he helped identify several schemes in which high magnetic fields could poten- tially help the fusion process. Some of the schemes

  6. An Overview of the Data Collected During the Cold Land Processes Field Experiment

    Microsoft Academic Search

    M. A. Parsons; M. J. Brodzik; T. Haran

    2003-01-01

    The Cold Land Processes field experiment (CLPX) was completed in the spring of 2003. Background data collection for the experiment began in the fall of 2001. Detailed data were collected during four intensive field campaigns during the winter and spring of 2002 and 2003. A total of 38 data sets were collected from ground-based, airborne and satellite instruments. Data range

  7. Overexpression of a blueberry-derived CBF enhances cold tolerance in a southern highbush blueberry cultivar

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Blueberry cultivars are subject to freezing damage in the winter and early spring. C-repeat binding factor (CBF) genes are transcription factors known to induce the expression of genes associated with cold acclimation and freezing tolerance. A CBF-encoding gene (BB-CBF) was isolated from the northe...

  8. Fate of carbon and nitrogen from animal manure and crop residues in wet and cold soils

    Microsoft Academic Search

    Martin H Chantigny; Denis A Angers; Philippe Rochette

    2002-01-01

    Organic matter transformations take place in snow-covered soils during winter but in ways still poorly understood. Given the generally high soil water content and possible formation of ice layers during this period, anaerobic zones could develop and have determinant effects on soil C and N dynamics. The fate of C and N under wet and cold conditions was monitored in

  9. Generation and analysis of 9792 EST sequences from cold acclimated oat, Avena sativa

    Microsoft Academic Search

    Marcus Bräutigam; Angelica Lindlöf; Shakhira Zakhrabekova; Gokarna Gharti-Chhetri; Björn Olsson; Olof Olsson

    2005-01-01

    BACKGROUND: Oat is an important crop in North America and northern Europe. In Scandinavia, yields are limited by the fact that oat cannot be used as a winter crop. In order to develop such a crop, more knowledge about mechanisms of cold tolerance in oat is required. RESULTS: From an oat cDNA library 9792 single-pass EST sequences were obtained. The

  10. Seasonal forecasts of the exceptional boreal winters of 2009/10 and 2010/11

    NASA Astrophysics Data System (ADS)

    Fereday, D.; Maidens, A.; Knight, J.; Scaife, A. A.; Arribas, A.; MacLachlan, C.; Peterson, D.

    2012-12-01

    The northern hemisphere winters of 2009/10 and 2010/11 were exceptional, with extremes of both atmospheric circulation and temperature. This presentation examines the causes and predictability of these extreme winters within the UK Met Office seasonal forecast system GloSea4. In winter 2009/10 the North Atlantic Oscillation (NAO) index was the lowest on record for over a century, contributing to cold conditions over large areas of Eurasia and North America. The then-operational version of GloSea4 used a "low top" model and successfully predicted a negative NAO in forecasts produced in September-November 2009. GloSea4 was later changed to use a "high top" model, which better simulates sudden stratospheric warmings. These events are shown to play an influential role in surface conditions, producing a stronger sea level pressure signal in the high top model and further improving retrospective predictions of the 2009/10 winter. Early winter 2010/11 also saw record-breaking cold anomalies over much of northern Europe, once again associated with a very negative NAO index. The negative winter NAO signal was forecast with near unanimity by the 11 WMO Global Producing Centres (including GloSea4) in September. Different potential mechanisms have been identified as driving the NAO, including El Niño-Southern Oscillation teleconnections, autumn Eurasian snow cover, Arctic ice extent and North Atlantic sea surface temperature (SST) anomalies. The representation of these mechanisms in GloSea4 is assessed using hindcasts for the period 1989-2009. The November 2010 forecast for December is examined using ensembles of atmosphere only runs, forced with SST fields as forecast in November 2010. We relax possible forcings (the strong La Niña in November 2010, the Arctic ice field, and the North Atlantic SST tripole) back to climatology to see which forcings produce the cold signal over Europe in December, and conclude that the main driver was the North Atlantic SST tripole.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Changes in wheat leaf phenolome in response to cold acclimation.

    PubMed

    Moheb, Amira; Ibrahim, Ragai K; Roy, René; Sarhan, Fathey

    2011-12-01

    A study of wheat (Triticum aestivum L.) leaves phenolome was carried out during cold acclimation of the winter (Claire) and spring (Bounty) varieties using a combination of HPLC-ESI-MS techniques. A total of 40 phenolic and flavonoid compounds were identified, and consisted mainly of two coumarin derivatives, eight simple phenolic derivatives, 10 hydroxycinnamoyl amides and 20 flavonoid derivatives. Identification and quantification of individual compounds were performed using an HPLC system coupled with a photodiode array detector and two different ESI-MS systems, in combination with a multiple reaction monitoring (MRM) technique. The analyses indicated that, although there were no qualitative differences in their profiles, the winter variety exhibited a higher phenolic content compared to the spring variety when both were grown under non-acclimated (control) conditions. Cold acclimation, on the other hand, resulted in a significant differential accumulation of phenolic compounds in both varieties: mostly as luteolin C-glycosides and their O-methyl derivatives in the winter variety (Claire) and a derivative of hydroxycinnamoyl amide in the spring variety (Bounty). These compounds accumulated in relatively large amounts in the apoplastic compartment. The accumulation of the O-methylated derivatives was associated with a marked increase in O-methyltransferase (OMT) activity. In addition, the trimethylated flavone, 3',4',5'-trimethyltricetin was identified for the first time in the native extracts of both control and cold-acclimated wheat leaves. The accumulation of a mixture of beneficial flavonoids, such as iso-orientin, vitexin and tricin in cold acclimated wheat leaves, attests for its potential as an inexpensive source of a health-promoting supplement to the human diet. PMID:21955620

  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. Informing the front line about common respiratory viral epidemics.

    PubMed

    Gesteland, Per H; Samore, Matthew H; Pavia, Andrew T; Srivastava, Rajendu; Korgenski, Kent; Gerber, Kristine; Daly, Judy A; Mundorff, Michael B; Rolfs, Robert T; James, Brent C; Byington, Carrie L

    2007-01-01

    The nature of clinical medicine is to focus on individuals rather than the populations from which they originate. This orientation can be problematic in the context of acute healthcare delivery during routine winter outbreaks of viral respiratory disease where an individuals likelihood of viral infection depends on knowledge of local disease incidence. The level of interest in and perceived utility of community and regional infection data for front line clinicians providing acute care is unclear. Based on input from clinicians, we developed an automated analysis and reporting system that delivers pathogen-specific epidemic curves derived from a viral panel that tests for influenza, RSV, adenovirus, parainfluenza and human metapneumovirus. Surveillance summaries were actively e-mailed to clinicians practicing in emergency, urgent and primary care settings and posted on a web site for passive consumption. We demonstrated the feasibility and sustainability of a system that provides both timely and clinically useful surveillance information. PMID:18693841

  18. 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.

  19. Detection of cold pain, cold allodynia and cold hyperalgesia in freely behaving rats

    Microsoft Academic Search

    Andrew J Allchorne; Daniel C Broom; Clifford J Woolf

    2005-01-01

    BACKGROUND: Pain is elicited by cold, and a major feature of many neuropathic pain states is that normally innocuous cool stimuli begin to produce pain (cold allodynia). To expand our understanding of cold induced pain states we have studied cold pain behaviors over a range of temperatures in several animal models of chronic pain. RESULTS: We demonstrate that a Peltier-cooled

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

    PubMed

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

    2010-01-01

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

  1. Seasonal variations of trimethylamine oxide and urea in the blood of a cold-adapted marine teleost, the rainbow smelt

    Microsoft Academic Search

    James A. Raymond

    1994-01-01

    Trimethylamine oxide (TMAO), which has previously not been known to occur in significant amounts in the blood of marine teleosts,\\u000a rose to concentrations of approximately 50 mM in the blood of winter-acclimatized rainbow smelt, Osmerus mordax. Urea also increased in the blood of cold-acclimatized smelt, and, with TMAO, contributed significantly to the winter freezing\\u000a point depression. TMAO and urea also

  2. Deep Thermal Front (southeastern Brazilian coast) see through acoustics: a preliminary study from an operational oceanography perspective

    NASA Astrophysics Data System (ADS)

    Ponsoni, L.; Hermand, J.-P.; da Silveira, I. C. A.

    2012-04-01

    The continental shelf region off the southeastern Brazilian coast (between 20°S and 28°S) is characterized by intrusions of the relatively cold and fertile South Atlantic Central Water (SACW) from the open ocean. Prediction and monitoring of this water mass are topics of great interest given its importance, for example, on climate, carbon cycle, fishing, mariculture, nutrients and pollutants dispersion, and for the oil industry. The intersection of the 18°C isotherm with the seafloor is appointed in the literature as a good tracer for SACW presence on the continental shelf and also to characterize the Deep Thermal Front (DTF) [Castro, 1996]. Among different factors that drive the SACW penetration on the continental shelf, one prominent mechanism is the water transport driven by the conditions of NE-E wind forcing. These winds varies seasonally, and they are prevalent during the spring and summer months. During these months, the water column is generally stratified due the combined effects of solar heating and DTF presence. In contrast, the reverse effect is characteristic in winter, when the water column is nearly homogeneous, relatively colder on the surface and relatively warm close to the bottom. Consequently, the sound speed field changes and thus the acoustic rays are propagated with different characteristics depending on presence, absence or DTF position. Considering this information, acoustics may provide an additional source of data that supplements the other conventional methods (e.g., hydrographic moorings and cruises, buoys, gliders, and others) for tracking and monitoring the front movement. In addition, it is worth emphasizing that acoustic methods present one interesting advantage in that they are able to sample the water column over large three-dimensional distances on an effectively synoptic scale. In this paper, a preliminary study of acoustic propagation modelling through one vertical section off the Brazilian southeastern coast at Cananéia region (state of São Paulo) is presented. Theorical temperature and salinity fields with differents conditions of DTF position are used for the calculations. Notable variations in the transmission loss field, rays propagations and time arrivals are found when the DTF is moving. These results support the idea that acoustics can be an interesting tool in monitoring and tracking of DTF movement, especially in the context of an intregrated program of observational oceanography and numerical ocean modeling.

  3. The Front End Fermi National Accelerator Lab

    E-print Network

    McDonald, Kirk

    The Front End MAP Review Fermi National Accelerator Lab August 24-26, 2010 Harold G. Kirk Brookhaven National Laboratory #12;August 2426, 2010 MAP ReviewFront End Harold G. Kirk 2 Outline Define Front End Major Sub-systems Key Challenges Milestones #12;August 2426, 2010 MAP

  4. Front End Chicane Parameters J. Scott Berg

    E-print Network

    McDonald, Kirk

    Mu onAccelera tor Program Front End Chicane Parameters J. Scott Berg Brookhaven National Laboratory MAP Front End Meeting 25 March 2014 #12;Introduction Mu onAccelera tor Program Goal: optimize chicane in chicane length and angle 25 March 2014 J. S. Berg | Chicane | Front End Meeting (2) #12;Performance

  5. Front End Chicane Chicane Geometry and Absorber

    E-print Network

    McDonald, Kirk

    National Laboratory MAP Front End Meeting 6 May 2014 #12;Introduction Mu onAccelera tor Program GoalMu onAccelera tor Program Front End Chicane Chicane Geometry and Absorber J. Scott Berg Brookhaven 2014 J. S. Berg | Chicane | MAP Front End (2) #12;Previous Status (1 April) Mu onAccelera tor Program

  6. Front growth and local mixing

    NASA Astrophysics Data System (ADS)

    Sanchez, M. A.; Garzon, G.; Redondo, J. M.

    2009-04-01

    The instability produced if a shock or suddent acceleration takes place is known as Richtmyer-Meshkov (RM) instability. Front advance and mixing is studied analyzing mixedness,[2] the third order structure functions, that indicate strong inverse cascades towards the large scales producing spectral variations[3]. The mixing processes are compared by mapping the different intermittency and the multifractal scaling in the spike and bubble arrays [1] Redondo J.M. and Garzon G. (2004) Multifractal structure and intermittency in Rayleigh-Taylor Driven Fronts. Ed. S. Dalziel www.damtp.cam.ac.uk/iwpctm9/proceedings/IWPCTM9/Papers/Programme.htm [2] Redondo, J.M. and Cantalapiedra I.R. (1993) Mixing in Horizontally Heterogeneous Flows. Jour. Flow Turbulence and Combustion. 51. 217-222. [3] Castilla R, Babiano A. and Redondo J.M. (2009) Coherent vortices and Lagrangian Dynamics in 2D Turbulence. Non-Linear Processes in Geophysics

  7. Cold Regions Bibliography

    NSDL National Science Digital Library

    A joint endeavor of the Federal Research Division of the Library of Congress and the US Army Cold Regions Research and Engineering Laboratory (CRREL), this project disseminates information on Antarctica and cold regions science and technology "by maintaining and continually updating a database which is an accumulation of over 40 years of materials on the science and technology of the world's cold regions." This database currently contains over 208,000 records, with about 6,000 accessions annually. After entering a supplied user id and password, users can search the database by keyword, author, or year of publication. Search returns include title, source, and a link to more information, including pages, notes, series, and publisher information. A DOS version of the database is also available for limited periods to qualified researchers. More information is available at the site.

  8. Cold asymmetrical fermion superfluids

    SciTech Connect

    Caldas, Heron

    2003-12-19

    The recent experimental advances in cold atomic traps have induced a great amount of interest in fields from condensed matter to particle physics, including approaches and prospects from the theoretical point of view. In this work we investigate the general properties and the ground state of an asymmetrical dilute gas of cold fermionic atoms, formed by two particle species having different densities. We have show in a recent paper, that a mixed phase composed of normal and superfluid components is the energetically favored ground state of such a cold fermionic system. Here we extend the analysis and verify that in fact, the mixed phase is the preferred ground state of an asymmetrical superfluid in various situations. We predict that the mixed phase can serve as a way of detecting superfluidity and estimating the magnitude of the gap parameter in asymmetrical fermionic systems.

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

    E-print Network

    Grogan, Paul

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

  10. Energy use and management of energy reserves in hatchling turtles (Chrysemys picta) exposed to variable winter conditions

    E-print Network

    Lee Jr., Richard E.

    Energy use and management of energy reserves in hatchling turtles (Chrysemys picta) exposed Hibernation Reptile a b s t r a c t The painted turtle (Chrysemys picta) is an especially useful organism. picta hatchlings to 4, 10, or 15 1C, temperatures simulating cold, mild, and warm winters, respectively

  11. Analysis of the Winter Low-Flow Balance of the Semiarid White River, Nebraska and South Dakota

    Microsoft Academic Search

    M. G. Ferrick; N. D. Mulherin; D. J. Calkins

    1995-01-01

    Low-flow studies are needed to quantify the effects of water consumption on streamflow, water quality, groundwater resources, and contaminant transport. The low-flow water balance of a river in a cold region is simplified in winter because evapotranspiration is negligible, irrigation water withdrawals and diversions are halted, and precipitation occurs largely as snow, minimizing the spatial and temporal variability of runoff.

  12. Analysis of the winter low-flow balance of the semiarid White River, Nebraska and South Dakota

    Microsoft Academic Search

    M. G. Ferrick; N. D. Mulherin; D. J. Calkins

    1995-01-01

    Low-flow studies are needed to quantify the effects of water consumption on streamflow, water quality, groundwater resources, and contaminant transport. The low-flow water balance of a river in a cold region is simplified in winter because evapotranspiration is negligible, irrigation water withdrawals and diversions are halted, and precipitation occurs largely as snow, minimizing the spatial and temporal variability of runoff.

  13. Cold war anthropology: Collaborators and victims of the national security state

    Microsoft Academic Search

    David H. Price

    1998-01-01

    This paper examines some of the interactions between anthropologists and America's National Security State during the Cold War. The Human Ecology Fund, an anthropological funding front used by the Central Intelligence Agency in the 1950s and 1960s, is discussed to elucidate one of the ways that the National Security State sponsored and consumed anthropological knowledge Clyde Kluckhohn's secret interactions with

  14. 1992 AGU Front Range Meeting

    NASA Astrophysics Data System (ADS)

    Rush, Sandra

    The AGU Front Range Branch held its annual meeting on February 10, 1992, at the National Center for Atmospheric Research in Boulder, Colo. The theme of the meeting was “Our Changing Environment,” with specific emphasis on the Rocky Mountains, the Front Range, the High Plains, and the Great Basin environments.The all-day meeting featured twenty oral presentations and five poster presentations. Most of the topics presented were related to environmental issues such as ozone depletion, emergency response applications at the Rocky Flats Plant, climatic forcing, and hydrogeology. Other papers of interest included a geophysical study of the Sand Dunes National Monument in Colorado, a paper on the impact of the 1988 forest fires on the chemistry of nonthermal groundwater at Yellowstone National Park, and a poster on the soil-gas flux of carbon dioxide from nonventing areas of the Kilauea Summit in Hawaii. A poster and an oral presentation centered on the vulnerability of transportation and energy supply networks in the central United States to earthquakes in the New Madrid seismic zone. The field of space science was represented by two posters on recent geomagnetic behaviors and magnetospheric convection and an oral presentation on plasma density in the Earth's magnetosphere. Three Front Range Branch awards were given to students to recognize excellent presentations.

  15. External Resource: Fronts: The Boundaries Between Air Masses

    NSDL National Science Digital Library

    1900-01-01

    This University of Illinois educational guide educates students about fronts, the boundaries between air masses. Fronts extend not only in the horizontal direction, but in the vertical as well. Topics: horizontal front, vertical front, stationary, warm,

  16. 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

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

    NASA Astrophysics Data System (ADS)

    Ren, Shihe; Xie, Jiping; Zhu, Jiang

    2014-09-01

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

  18. Seasonal forecasts of northern hemisphere winter 2009/10

    NASA Astrophysics Data System (ADS)

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

    2012-09-01

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

  19. Solar forcing of winter climate variability in the northern hemisphere

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

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

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

    PubMed Central

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

    2011-01-01

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

  1. Arctic atmospheric circulation patterns responsible for dry and cold air inflows to the Baltic Sea region

    NASA Astrophysics Data System (ADS)

    Post, Piia; Sepp, Mait

    2015-04-01

    Essential changes have taken place in atmospheric circulation over the Northern Atlantic in winter and spring during the second half of the 20th century. The winter temperature rise in Europe is frequently attributed to the intensification of zonal flow on the Northern Atlantic region and the same is valid for the Baltic Sea region. Intensification of zonal circulation and its expression through NAO and AO indices have been thoroughly studied, but less is known about mechanisms causing declination from the zonality of flow. Extremely cold weather in winter and spring in Baltic Sea region is related to the radiative cooling or advection of cold air masses. In both cases, the typical western flow is blocked and the region is directly influenced by atmospheric circulation conditions in the Arctic through the cold air advection events. Our aim is to study which large scale atmospheric circulation patterns are responsible for this kind of cold air advection to the Baltic Sea region in winter and spring (from December to May). The second task is to identify if this kind of circulation has become less frequent in the region under research beginning from the last half of the 20th century till now. Describing the atmospheric circulation patterns we use several classifications of atmospheric circulation on daily level. The domain of the classifications covers Atlantic-European sector of the Arctic, including area between Greenland and Novaya Zemlya archipelago. Manual classifications by Vangengeim-Girs and Dzerdzejevski are used, but also several newly calculated ones, that apply different classification methods from cost733class software. For the latter ones geopotential height fields at 500 hPa level from NCEP-NCAR reanalysis are classified for the period 1948-2013. The cold air advection events are determined by daily temperature drops by at least 3°C during 24 hours. The circulation types that bring advection of cold Arctic air to the Baltic Sea region are analysed in detail.

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

    NASA Astrophysics Data System (ADS)

    Stark, David

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

  3. Winter Snowfall Turns an Emerald White

    NASA Technical Reports Server (NTRS)

    2001-01-01

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

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

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

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

  4. 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

  5. [Gender differences of Pomacea canaliculata in cold tolerance].

    PubMed

    Guo, Jing; Guo, Jing; Xu, Wu-Bing; Zhang, Jia-En; Zhao, Ben-Liang; Luo, Ming-Zhu

    2014-06-01

    In order to understand whether Pomacea canaliculata exhibits gender differences in cold resistance, the survival rate and supercooling point of both P. canaliculata females and males were investigated at low temperature. The changes in physiological and biochemical indices in the body of P. canaliculata before and after the winter were also examined. The results showed that the mean supercooling point of females was -6.83 degrees C, which was significantly lower than that of the males (-6.26 degrees C). With the arrival of winter, the amounts of bound water, glycerol, lipid and glycogen of P. canaliculata increased, while the amount of free water decreased. These indices except glycerol showed significant differences between males and females. More than 90% non-acclimated snails could survive at the temperature of 10 degrees C for 7 days. The survival rate of snails exhibited significant differences in sex and shell height after being transferred at 5 degrees C for 7 days. In addition, more females were recorded during field investigation. Based on these results, we concluded that the females had higher cold tolerance than the males. This finding would provide some references for further investigation of ecological adaptation, natural sex ratio and cold tolerance mechanisms of P. canaliculata. PMID:25223040

  6. Attribution of UK Winter Floods to Anthropogenic Forcing

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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...

  12. 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…

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

    Microsoft Academic Search

    Jilin Sun; Xiaomeng Shi; Yan Jiao; Xinxin Ye

    2010-01-01

    Using monthly mean sea surface temperature anomaly (SSTa) in the Northern Atlantic and Arctic from 1951-2004,the reanalysis data of sea surface pressure, air temperature and geopotential height at 500 hPa, SVD analysis were done to study the relations among the SSTa's and the cold air activity over the east China marginal seas. It is found that?in boreal winter, cold air

  14. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2005-05-01

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

  16. Winter Break Activities and Attractions Fighting the Winter Blues

    E-print Network

    Mountziaris, T. J.

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

  17. Effect of low winter temperatures on milk production of dairy cows grazed on farms in a warm temperate climate (Australia)

    NASA Astrophysics Data System (ADS)

    Dragovich, D.

    1980-06-01

    Two-day milk production figures for dairymen at Armidale (31° S Lat.) and Goulburn (35° S Lat.), Australia, were compared with minimum daily temperatures. Comparisons were made between production levels on days with temperatures above and below 0°C, and between days with varying intensities of cold: differences in production were minor. The infrequent, more prolonged periods of cold weather (“cold” being days on which the minimum temperature was below 0°C) were also associated with only very slight reductions in milk output; and the most pronounced decline in production was not attributable to low temperatures. Although short-term fluctuations in output were not related to low temperature events or low temperatures in combination with rain, thermal stress on plant growth during winter contributed to a seasonal downturn in production and below-average annual milk yields in areas with low winter temperatures.

  18. The Effect of CSP310 on Lipid Peroxidation and Respiratory Activity in Winter Wheat Mitochondria

    Microsoft Academic Search

    V. V. Zykova; O. I. Grabelnykh; V. V. Tourchaninova; A. I. Antipina; N. A. Koroleva; A. V. Kolesnichenko; T. P. Pobezhimova; Yu. M. Konstantinov; V. K. Voinikov

    2002-01-01

    Certain concentrations of the cold-shock protein (CSP310) were shown to induce systems of lipid peroxidation (POL) in winter wheat (Triticum aestivum L.) mitochondria in vitro. The process of nonenzymatic POL turned out to be the most sensitive to the presence of CSP310 in the incubation medium. The maximum induction of the enzymatic POL occurred at a higher CSP310 concentration. Wheat,

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

    NASA Astrophysics Data System (ADS)

    Gómez, I.; Estrela, M.

    2009-09-01

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

  20. Metabolic and molecular stress responses of gilthead seam bream Sparus aurata during exposure to low ambient temperature: an analysis of mechanisms underlying the winter syndrome

    Microsoft Academic Search

    Themis-Dimitrios KyprianouHans; Hans O. Pörtner; Andreas Anestis; Basile Kostoglou; Konstantinos Feidantsis; Basile Michaelidis

    2010-01-01

    The winter syndrome in the gilthead sea bream Sparus aurata indicates that the species is exposed to critically low temperatures in Mediterranean aquaculture in winter. The present\\u000a study of metabolic patterns and molecular stress responses during cold exposure was carried out to investigate this “disease”,\\u000a in light of the recent concept of oxygen and capacity limited thermal tolerance. The metabolic

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

    NASA Astrophysics Data System (ADS)

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

    2013-03-01

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

  2. 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

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  4. 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

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

    E-print Network

    Maxwell, Bruce D.

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

  6. Britannica Sporting Record: The Winter Games

    NSDL National Science Digital Library

    Encyclopaedia Britannica, Inc.

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

  7. Up Front Blog: Brookings Institution

    NSDL National Science Digital Library

    If you'd like a front row seat to some of the most compelling policy commentary in the United States, you may want to keep tabs on this useful blog from the Brookings Institution. Each weekday, different policy experts offer a bit of commentary on topics that include immigration policy, disaster preparedness, and the use of technology by the federal government. Visitors can comment on each entry, share the entry with friends and colleagues, and pass it along via their Twitter feed or other social media. The site also features past blog entries dating back to September 2009 and embedded links to other relevant Brookings Institution reports, working papers and briefs.

  8. Theoretical Models of Photodissociation Fronts

    E-print Network

    B. T. Draine; Frank Bertoldi

    2000-08-09

    Observations of H2 line emission have revealed higher-than-expected gas temperatures in a number of photodissociation fronts. We discuss the heating and cooling processes in photodissociation regions. Observations of NGC 2023 are compared to a theoretical model in which there is substantial gas at temperatures T = 500-1000K heated by photoelectric emission and collisional deexcitation of H2. In general the model successfully reproduces the observed H2 line emission from a wide range of energy levels. The observed [SiII]34.8um emission appears to indicate substantial depletion of Si in NGC 2023.

  9. Investigation of non-stationary self-focusing of intense laser pulse in cold quantum plasma using ramp density profile

    SciTech Connect

    Habibi, M. [Department of Physics, Shirvan Branch, Islamic Azad University, Shirvan (Iran, Islamic Republic of); Ghamari, F. [Department of Physics, Khorramabad Branch, Islamic Azad University, Khorramabad (Iran, Islamic Republic of)

    2012-11-15

    The authors have investigated the non-stationary self-focusing of Gaussian laser pulse in cold quantum plasma. In case of high dense plasma, the nonlinearity in the dielectric constant is mainly due to relativistic high intense interactions and quantum effects. In this paper, we have introduced a ramp density profile for plasma and presented graphically the behavior of spot size oscillations of pulse at rear and front portions of the pulse. It is observed that the ramp density profile and quantum effects play a vital role in stronger and better focusing at the rear of the pulse than at the front in cold quantum plasmas.

  10. Southern Ocean seasonal temperature and Subtropical Front movement on the South Tasman Rise in the late Quaternary

    Microsoft Academic Search

    E. L. Sikes; W. R. Howard; C. R. Samson; T. S. Mahan; L. G. Robertson; J. K. Volkman

    2009-01-01

    The Subtropical Front (STF) marking the northern boundary of the Southern Ocean has a steep gradient in sea surface temperature (SST) of approximately 4°C over 0.5° of latitude. Presently, in the region south of Tasmania, the STF lies nominally at 47°S in the summer and 45°S in the winter. We present here SST reconstructions in a latitudinal transect of cores

  11. Varietal Trials Results Wheat, Hard Red Winter

    E-print Network

    Thomas, David D.

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

  12. CULTIVAR DESCRIPTION CDC Kestrel winter wheat

    E-print Network

    Saskatchewan, University of

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

  13. CULTIVAR DESCRIPTION CDC Clair winter wheat

    E-print Network

    Saskatchewan, University of

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

  14. 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.

  15. Distribution and diurnal behavior of Steller's Eiders wintering on the Alaska Peninsula

    USGS Publications Warehouse

    Laubhan, M.K.; Metzner, K.A.

    1999-01-01

    We studied the distribution and activities of adult Steller's Eiders (Polysticta stelleri) during winter and spring on a deep-water embayment and a shallow lagoon along the Alaska Peninsula from September 1980 to May 1981. During the remigial molt, eiders were observed on Izembek Lagoon but not on Cold Bay. Following the flightless period, Izembek Lagoon continued to support 63-100% of eiders encountered during surveys. As ice cover on Izembek Lagoon increased, the number of birds decreased on Izembek Lagoon but increased on Cold Bay, suggesting that some eiders disperse to nearshore, deep-water habitats in close proximity to Izembek Lagoon during severe weather. Diurnal activity budgets indicated that the amount of time resting or engaged in aggression and alert activities was similar among locations, seasons, tidal stages, and sexes. In contrast, time spent foraging differed among seasons and locations but did not differ among tidal stages or sexes. Although time spent foraging was similar during winter and spring on Izembek Lagoon, eiders on Cold Bay foraged more during winter compared to spring. Synchronous diving was the dominant foraging strategy.

  16. Winter 2010 EVENTS FOCUS: RUSSIA

    E-print Network

    Eustice, Ryan

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

  17. Winter 1998 UC SANTA CRUZ

    E-print Network

    California at Santa Cruz, University of

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

  18. ASIAN DEVELOPMENT ECONOMICS Winter 2014

    E-print Network

    Carter, John

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

  19. Ecological Genetics Winter Term 2010

    E-print Network

    Adl, Sina

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

  20. 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.

  1. Reaction driven convection around a stably stratified chemical front.

    PubMed

    D'Hernoncourt, J; Zebib, A; De Wit, A

    2006-04-21

    A vertical stratification of a light and hot fluid over a heavy and cold one is expected to be stable with regard to buoyancy-driven convection. Here we show that chemical reactions can trigger convection around chemical fronts even in cases where concentration and heat both contribute to a stable density stratification. The balance between intrinsic thermal and solutal density gradients initiated by a spatially localized reaction zone and double diffusive mechanisms are at the origin of a new convective instability, the mechanism of which is explained by a displaced particle argument. Linear stability analysis of a reaction-diffusion-convection model confirmed by nonlinear simulations delimits the instability region in the parameter space spanned by the thermal and solutal Rayleigh numbers. Experimental systems in which to test our theoretical predictions are proposed. PMID:16712159

  2. Interannual control of plankton communities by deep winter mixing and prey/predator interactions in the NW Mediterranean: Results from a 30-year 3D modeling study

    NASA Astrophysics Data System (ADS)

    Auger, P. A.; Ulses, C.; Estournel, C.; Stemmann, L.; Somot, S.; Diaz, F.

    2014-05-01

    A realistic modeling approach is designed to address the role of winter mixing on the interannual variability of plankton dynamics in the north-western (NW) Mediterranean basin. For the first time, a high-resolution coupled hydrodynamic-biogeochemical model (Eco3m-S) covering a 30-year period (1976-2005) is validated on available in situ and satellite data for the NW Mediterranean. In this region, cold, dry winds in winter often lead to deep convection and strong upwelling of nutrients into the euphotic layer. High nutrient contents at the end of winter then support the development of a strong spring bloom of phytoplankton. Model results indicate that annual primary production is not affected by winter mixing due to seasonal balance (minimum in winter and maximum in spring). However, the total annual water column-integrated phytoplankton biomass appears to be favored by winter mixing because zooplankton grazing activity is low in winter and early spring. This reduced grazing is explained here by the rarefaction of prey due to both light limitation and the effect of mixing-induced dilution on prey/predator interactions. A negative impact of winter mixing on winter zooplankton biomass is generally simulated except for mesozooplankton. This difference is assumed to stem from the lower parameterized mortality, top trophic position and detritivorous diet of mesozooplankton in the model. Moreover, model suggests that the variability of annual mesozooplankton biomass is principally modulated by the effects of winter mixing on winter biomass. Thus, interannual variability of winter nutrient contents in the euphotic layer, resulting from winter mixing, would control spring primary production and thus annual mesozooplankton biomass. Our results show a bottom-up control of mesozooplankton communities, as observed at a coastal location of the Ligurian Sea.

  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. Front propagation and rejuvenation in flipping processes

    SciTech Connect

    Ben-naim, Eli [Los Alamos National Laboratory; Krapivsky, P I [BOSTON UNIV; Antal, T [HARVARD UNIV; Ben - Avrahm, D [HARVARD UNIV

    2008-01-01

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

  5. Playing Hot and Cold

    NSDL National Science Digital Library

    Fitzgerald, Meghan

    2007-02-20

    This lesson plan, published by the New York Times Learning Network, introduces the concept of homeothermy in animals. Students will come to understand the diversity among mammals and the adaptations that allow specific mammals to survive in their native climates. The class will read an article titled: "A Mammal in Winter With a Furnace of Her Own," which discusses how mammals maintain homeothermy through food consumption. The lesson plan also asks students to think about various mammals and their ability to survive in their climates, research mammals and create posters illustrating how homeothermy helps each animal to survive. Suggested interdisciplinary activities are also provided.

  6. 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.

  7. Cold cathodes for CFAs

    Microsoft Academic Search

    K. F. Ramacher; M. S. Worthington; G. R. MacPhail

    2000-01-01

    Summary form only given. Application of cold cathode technology for use in crossed-field amplifiers (CFAs) has been limited by the characteristics of the materials, usually platinum (Pt) or beryllium (Be\\/BeO), used as the emitter. A case in point is the L-4717, used as the second stage amplifier (baby Amplitron) in the SPS-48-C\\/E transmitters. This tube, which uses a thermionic emitter,

  8. Cold nuclear fusion

    SciTech Connect

    Tsyganov, E. N., E-mail: edward.tsyganov@utsouthwestern.edu [University of Texas Southwestern Medical Center at Dallas (United States)

    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.

  9. Crazy Cold Air

    NSDL National Science Digital Library

    In this classroom activity, students record the temperatures in and around a walk-in refrigerator or freezer to see how cold air behaves when it meets warmer air. The printable five-page handout includes a series of inquiry-based questions to get students thinking about how the temperature of air changes its density, detailed experiment directions and a worksheet that helps students use the experiment results to obtain insight into the wind patterns of Antarctica.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Light-Front Holographic QCD

    SciTech Connect

    Brodsky, Stanley J.; /SLAC /Southern Denmark U., CP3-Origins; 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

  15. Interannual variation of the southern limit in the Yellow Sea Bottom Cold Water and its causes

    NASA Astrophysics Data System (ADS)

    Yang, Hee-Won; Cho, Yang-Ki; Seo, Gwang-Ho; You, Sung Hyup; Seo, Jang-Won

    2014-11-01

    The Yellow Sea Bottom Cold Water (YSBCW) occupies a wide region below the Yellow Sea (YS) thermocline in summer. The southern limit of the YSBCW shows pronounced interannual variability. A regional ocean model with realistic forcing was used to identify the structure of the YSBCW and to investigate the causes of its interannual variability from 1981 to 2010. Sea surface temperature (SST) in winter is strongly correlated with the southern limit of the YSBCW in summer. The correlation coefficient between the August southern limit and the February SST is - 0.884. This result suggests that cold SST is associated with the increased southern limit in the following summer. Linear regression suggests that the southern limit increases by about 55 km when the SST in February decreases by 1 °C. The southern limits are more extended to the south in August than in June in some years despite surface heating. The difference in southern limits between June and August is positively correlated with the summer southerly wind stress with a correlation coefficient of 0.529. The contribution of SST in winter on the southern limit of the YSBCW in summer is larger than the wind stress in summer. The SST in winter is mainly determined by the air temperature and wind speed in winter. The other factor affecting winter SST is the previous year's bottom water temperature. The winter SST is significantly correlated with the bottom water temperature in previous year. The southern limit of the YSBCW in the observed data in the limited area has relatively weak correlation with the winter SST and summer southerly wind stress possibly due to observation error and uncertainty of the reanalysis wind.

  16. Functional identification of a blueberry CBF/DREB-like element associated with cold acclimation and freezing tolerance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Highbush blueberry (Vaccinium corymbosum L.) is susceptible to winter freezing injury and frost damage in the spring. As part of an ongoing project to understand the process of cold acclimation, we isolated a CBF/DREB-like (C-repeat binding factor/dehydration-responsive element binding protein) gene...

  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. The cold response of CBF genes in barley is regulated by distinct signaling mechanisms.

    PubMed

    Marozsán-Tóth, Zsuzsa; Vashegyi, Ildikó; Galiba, Gábor; Tóth, Balázs

    2015-06-01

    Cold acclimation ability is crucial in the winter survival of cereals. In this process CBF transcription factors play key role, therefore understanding the regulation of these genes might provide useful knowledge for molecular breeding. In the present study the signal transduction pathways leading to the cold induction of different CBF genes were investigated in barley cv. Nure using pharmacological approach. Our results showed that the cold induced expression of CBF9 and CBF14 transcription factors is regulated by phospholipase C, phospholipase D pathways and calcium. On the contrary, these pathways have negative effect on the cold induction of CBF12 that is regulated by a different, as yet unidentified pathway. The diversity in the regulation of these transcription factors corresponds to their sequence based phylogenetic relationships suggesting that their evolutionary separation happened on structural, functional and regulational levels as well. On the CBF effector gene level, the signaling regulation is more complex, resultant effect of multiple pathways. PMID:25974368

  20. No trade-off between high and low temperature tolerance in a winter acclimatized Danish Drosophila subobscura population.

    PubMed

    Sørensen, Jesper Givskov; Kristensen, Torsten Nygaard; Loeschcke, Volker; Schou, Mads Fristrup

    2015-06-01

    Coping with cold winter conditions is a major challenge for many insects. In early spring we observed newly emerged Drosophila subobscura, which had overwintered as larvae and pupae. As temperatures increase during spring these flies are faced with higher minimum and maximum temperatures in their natural microhabitat. Thus, there is a potential costly mismatch between winter and early spring acclimatization and the increased ambient temperatures later in adult life. We obtained individuals from a natural Danish population of D. subobscura and acclimated them in the laboratory to 20 °C for one generation, and compared critical thermal maximum (CTmax) and minimum (CTmin) to that of individuals collected directly from their natural microhabitat. The two populations (laboratory and field) were subsequently both held in the laboratory at 20 °C and tested for their CTmax and CTmin every third day for 28 days. At the first day of testing, field acclimatized D. subobscura had both higher heat and cold resistance compared to laboratory flies, and thereby a considerable larger thermal scope. Following transfer to the laboratory, cold and heat resistance of the field flies decreased over time relative to the laboratory flies. Despite the substantial decrease in thermal tolerances the thermal scope remained larger for field acclimatized individuals for the duration of the experiment. We conclude that flies acclimatized to their natural microhabitat had increased cold resistance, without a loss in heat tolerance. Thus while a negative correlation between cold and heat tolerance is typically observed in laboratory studies in Drosophila sp., this was not observed for field acclimatized D. subobscura in this study. We suggest that this is an adaptation to juvenile overwintering in temperate cold environments, where developmental (winter) temperatures can be much lower than temperatures experienced by reproducing adults after emergence (spring). The ability to gain cold tolerance through acclimatization without a parallel loss of heat tolerance affects thermal scope and suggests that high and low thermal tolerance act through mechanisms with different dynamics and reversibility. PMID:25846012

  1. Stability of front solutions in inhomogeneous media

    NASA Astrophysics Data System (ADS)

    Prat, Alain; Li, Yue-Xian

    2003-12-01

    We use the FitzHugh-Nagumo (F-N) model to study front solutions in inhomogeneous media. Inhomogeneity is modeled by adding a space-dependent term, z( x), in the equations. Changes in z shift the cubic nullcline up and down in the phase-plane of the F-N model. This is used to mimic shifts in the cubic-shaped nullcline of a bidomain model of calcium waves in egg cells [Physica D, in press] caused by changes in the total calcium concentration. Conditions for the existence and stability of stationary front solutions for a general class of z functions are obtained analytically when the dynamics are piecewise linear. We show that spatial inhomogeneities cause pinning and oscillations of front solutions. This is best demonstrated when z( x) is a linear ramp. When the slope is large, a linear ramp breaks the translational invariance of the stationary front and stabilizes the front. The front becomes less stable as the slope decreases. At a critical slope, the front becomes unstable through a Hopf bifurcation beyond which oscillations in the front occur. This also occurs for nonlinear spatial inhomogeneities including a step increase with varying magnitude and steepness. This bifurcation has been found previously [Physica D 106 (1997) 270; Phys. Rev. E 55 (1997) 366] in a local analysis of the F-N model near a co-dimension two point (sometimes called a non-equilibrium Ising-Bloch (NIB) bifurcation) and with inhomogeneities of small magnitude. The analysis presented here applies globally in parameter space and is valid for inhomogeneities of arbitrary magnitude. We show that this bifurcation need not occur in conjunction with the NIB point. It is caused exclusively by spatial inhomogeneity. A rich variety of wave phenomena including front oscillation, front pinning, and front reflection are shown to occur in inhomogeneous media.

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

    E-print Network

    .ukans.edal~phillAuslegung.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 Kansas Graduate Student Council. All rights reserved 2003 Auslegung: A...

  3. Mid-American Review of Sociology, Volume 1, Number 2 (WINTER, 1976): Front Matter

    E-print Network

    1976-01-01

    State University Robert R. Ringers 33 CYNTHIA FLYNN Supervising Editor RODNEY K. BAXTER Wichita State University ASSOCIATE EDITORS BARBARA GRINTER University of Missouri­ Kansas City WAYNE DERX Managing Editor STAFF HERB HAINES, AL JOHNSON, MARTHA...

  4. 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.

  5. Auslegung: a journal of philosophy, Volume 23, Number 1 (Winter/Spring 2000): Front Matter

    E-print Network

    Johnson, Bill Martin, Roy Martinez, John McClendon, Jeanna Moyer, Patrick Rardin, David Reidy, Jim Tuedio, Danney Ursery, Joe D. Van Zandt, Andrew Ward, Darrell Wheeler, Chris Creighton University Purdue University, Calumet Campus St.... Norbert College University of Minnesota, Morris University of Missouri, Kansas City University of Central Arkansas Middle Tennessee State University DePaul University Spelman College Bates College Iowa State University Appalachian State University...

  6. Mid-American Review of Sociology, Volume 10, Number 2 (WINTER, 1985): Front Matter

    E-print Network

    1985-01-01

    ISSN: 0732-913X Edited at the Departmen t of Sociology, University of Kansas Managing Editor TIM KNAPP ERIC PLUTZER DAVID J. PITTMAN Washington University MICHAEL R. HILL HUGH P. WHITT University of Nebraska-Lincoln Book Review Editor CHRISTOPHER...

  7. Mid-American Review of Sociology, Volume 13, Number 1 (WINTER, 1988): Front Matter

    E-print Network

    1988-01-01

    ISSN:0732-913X Edited at the Department of Sociology, University of Kansas Mid-American Review of Sociology MICHAEL R. HILL HUGH P. WHITT University of Nebraska-Lincoln PAMELA S. SANDERS KATHLEEN M. O'FLAHERTY Wichita State University ERICPLufrn...

  8. 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

  9. Cold molecular gas and history of the Universe.

    NASA Astrophysics Data System (ADS)

    Combes, F.; Wiklind, T.

    1997-09-01

    Molecular absorption in front of radio-loud quasars is a unique tool to probe cold gas at high redshifts, with the benefit of high angular and velocity resolutions. Molecular abundances, and excitation temperatures can be studied at length in remote galaxies. The diffuse components allow to obtain an upper limit on the temperature of the cosmic background radiation as a function of redshift. Since the cross-section for absorption is very small around a galaxy, the absorbing systems are either internal, or coming from a gravitational lens. The molecular measurements can then contribute to cosmological determination.

  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.

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

    E-print Network

    Reding, Philip John

    1992-01-01

    , Belize from 5 March 1984, 1200 UTC to 9 March 1984, 1200 UTC . . 86 As in Fig. 51, except at Guatemala City, Guatemala from 3 March 1984, 1200 UTC to 12 March 1984, 1200 UTC . . 88 53 54 55 Total preciptable water (kg/m2) field on 3 March 1984...-26 November 1987. . . . . . . . 106 66. Vertical temporal cross section at Guatemala City, Guatemala fiom 16 November 1987, 1200 UTC to 27 November 1987, 1200 UTC. . . . . . . . . 108 67 68. As in Fig. 66, except at Tegucigalpa, Honduras from 17 November...

  12. Influence of the preceding winter Northern Hemisphere annular mode on the spring extreme low temperature events in the north of eastern China

    NASA Astrophysics Data System (ADS)

    Yin, S.; Feng, J.; Li, J.

    2012-04-01

    The relationship between the preceding boreal winter Northern Hemisphere annular mode (NAM) and the spring extreme low temperature events in the north of eastern China during 1959-2008 was examined in this study. The results show that there exists a significantly negative relationship between the preceding winter (December-March) NAM and the following spring (March-May) extreme low temperature events in the north of eastern China. When the preceding winter NAM is strong, in the following spring negative (positive) geopotential height anomalies occur in the upper (lower) levels over the north of eastern China, and anomalous sinking motion and vertical heating are accompanied in the same area and cold vortex over Northeast China would be weak, resulting in less extreme low temperature events. The opposite circulation patterns in the spring are obviously observed in weak preceding winter NAM years. Furthermore, the possible physical mechanism associated with impact of the preceding winter NAM on the subsequent spring extreme low temperature events in the north of eastern China is explored. The results indicate that the Eurasian snow cover is a potential bridge connecting the signals in winter NAM and spring extreme low temperature events in the north of eastern China. When the preceding winter NAM is strong (weak), mid-high latitudes of Eurasia are warmer (colder) and Eurasian snow extent is smaller (larger) than normal. Besides, Eurasian snow extent anomalies in the preceding winter can strongly persist to the following spring. That is when the preceding winter Eurasian snow extent is small, accordingly in the following spring cold vortex over Northeast China would be weak and the surface air temperature in the north of eastern China is high, resulting in less extreme low temperature events, and vice verse. Therefore, the preceding winter NAM contributes to the frequency and strength of the following spring extreme low temperature in the north of eastern China, yielding a potential valuable signal in predicting the spring extreme low temperature events in the above-mentioned region.

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  14. Structure of Stationary Photodissociation Fronts

    E-print Network

    B. T. Draine; Frank Bertoldi

    1996-03-08

    The structure of stationary photodissociation fronts is revisited. H_2 self- shielding is discussed, including the effects of line overlap. We find that line overlap is important for N(H_2) > 10^{20} cm^{-2}. We compute multiline UV pumping models, and compare these with simple analytic approximations for the effects of self-shielding. The overall fluorescent efficiency of the photodissociation front is obtained for different ratios of chi/n_H (where chi characterizes the intensity of the incident UV) and different dust extinction laws. The dust optical depth tau_{pdr} to the point where 50% of the H is molecular is found to be a simple function of a dimensionless quantity phi_0 depending on chi/n_H, the rate coefficient for H_2 formation on grains, and the UV dust opacity. The fluorescent efficiency of the PDR also depends primarily on phi_0 for chi10^4K, but shows some sensitivity to the v-J distribution of newly-formed H_2. The 1-0S(1)/2-1S(1) and 2-1S(1)/6-4Q(1) intensity ratios, the ortho/para ratio, and the rotational temperature in the $v$=1 and $v$=2 levels are computed as functions of the temperature and density, for different values of chi and n_H. We apply our models to the reflection nebula NGC 2023. We are best able to reproduce the observations with models having chi=5000, n_H=10^5 cm^{-3}.

  15. Impacts of forest harvest on cold season land surface conditions and land-atmosphere interactions in northern Great Lakes states

    NASA Astrophysics Data System (ADS)

    Garcia, Matthew; Özdogan, Mutlu; Townsend, Philip A.

    2014-09-01

    Land cover change, including temporary disturbances such as forest harvests, can significantly affect established regimes of surface energy balance and moisture exchange, altering flux processes that drive weather and climate. We examined the impacts of forest harvest on winter land-atmosphere interactions in a temperate region using high-resolution numerical modeling methods in paired simulations. Using the WRF-ARW atmospheric model and the Noah land surface model, we simulated the balance of surface sensible and latent heat fluxes and the development and dissipation of a stable nocturnal boundary layer during generally calm synoptic conditions. Our results show reduced daily-average snow-covered land surface sensible heat flux (by 80%) and latent heat flux (by 60%) to the atmosphere in forest clearings due to albedo effects and rebalancing of the surface energy budget. We found a land surface cooling effect (-8 W m-2) in snow-covered cleared areas, consistent with prior modeling studies and conceptual understanding of the mechanisms for midlatitude deforestation to offset anthropogenic global warming at local scales. Results also demonstrate impacts of forest clearing on the passage of a weak cold front due to altered near-surface winds and boundary layer stability. We show significant differences in both surface conditions and fluxes between harvested and undisturbed forest areas. Our results demonstrate the potential utility of high-resolution remote sensing analyses to represent transient land cover changes in model simulations of weather and climate, which are usually undertaken at coarser resolutions and often overlook these changes at the land surface.

  16. Writing TAFS for Winter Weather

    NSDL National Science Digital Library

    COMET

    2009-09-22

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

  17. 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.

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

    PubMed Central

    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

  19. 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

  20. Atmospheric fronts in current and future climates

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

    Atmospheric fronts are important for the day-to-day variability of weather in the midlatitudes. It is therefore vital to know how their distribution and frequency will change in a projected warmer climate. Here we apply an objective front identification method, based on a thermal front parameter, to 6-hourly data from models participating in Coupled Model Intercomparison Project phase 5. The historical simulations are evaluated against ERA-Interim and found to produce a similar frequency of fronts and with similar front strength. The models show some biases in the location of the front frequency maxima. Future changes are estimated using the high emissions scenario simulations (Representative Concentration Pathway 8.5). Projections show an overall decrease in front frequency in the Northern Hemisphere, with a poleward shift of the maxima of front frequency and a strong decrease at high latitudes where the temperature gradient is decreased. The Southern Hemisphere shows a poleward shift of the frequency maximum, consistent with previous storm track studies.

  1. The APS beamline front end vacuum system

    Microsoft Academic Search

    Nielsen

    1993-01-01

    This report discusses the design of the vacuum system for the advanced photon source beamline front ends. Included in this report are discussions on: vacuum calculations, the differential pump; front end vacuum set points; cleaning methods and agents; and continuing and completed research and development.

  2. On the Fragmentation Front in Conduit

    Microsoft Academic Search

    S. Kudomi; K. Kurita

    2001-01-01

    Vesiculation and fragmentation of magma in the conduit are the most fundamental processes to characterize explosive eruption. The interval from the vesiculation front to the fragmentation front critically controls the size distribution of pyroclasts and hence the style of eruption. The vesiculation process has been extensively investigated through experimental and model-simulational approaches. As for the fragmentation process, on the other

  3. 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.

  4. 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.

  5. Peregrinations on cold fusion

    SciTech Connect

    Turner, L.

    1989-01-01

    Attention is focused on the possibility of resonance-enhanced deuteron Coulomb barrier penetration. Because of the many-body nature of the interactions of room-temperature deuterons diffusing through a lattice possessing deuterons in many of the interstitial positions, the diffusing deuterons can resonate on the atomic scale in the potential wells bounded by the ascending walls of adjacent Coulomb barriers and thereby penetrate the Coulomb barriers in a fashion vastly underestimated by two-body calculations in which wells for possible resonance are absent. Indeed, perhaps the lack of robust reproducibility in cold fusion originates from the narrowness of such transmission resonances. 4 refs., 1 fig.

  6. 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.

  7. Hot and Cold

    NSDL National Science Digital Library

    Oregon Museum of Science and Industry

    1997-01-01

    In this activity, learners explore temperature changes from chemical reactions by mixing urea with water in one flask and mixing calcium chloride with water in another flask. They observe that the urea flask gets cold and the calcium chloride flask gets hot. The main idea is that some chemical processes release heat energy and are exothermic, while some chemical processes absorb heat energy and are endothermic. This activity is currently used in the Nature of Matter Unit in OMSI's Chemistry Lab. Cost estimates are per 100 learners.

  8. Winter Storms For More Information

    E-print Network

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

  9. The transition zone chlorophyll front, a dynamic global feature defining migration and forage habitat for marine resources

    NASA Astrophysics Data System (ADS)

    Polovina, Jeffrey J.; Howell, Evan; Kobayashi, Donald R.; Seki, Michael P.

    Pelagic ecosystem dynamics on all temporal scales may be driven by the dynamics of very specialized oceanic habitats. One such habitat is the basin-wide chlorophyll front located at the boundary between the low chlorophyll subtropical gyres and the high chlorophyll subarctic gyres. Global satellite maps of surface chlorophyll clearly show this feature in all oceans. In the North Pacific, the front is over 8000 km long and seasonally migrates north and south about 1000 km. In the winter this front is located at about 30-35°N latitude and in the summer at about 40-45°N. It is a zone of surface convergence where cool, vertically mixed, high chlorophyll, surface water on the north side sinks beneath warm, stratified, low chlorophyll water on the south side. Satellite telemetry data on movements of loggerhead turtles and detailed fisheries data for albacore tuna show that both apex predators travel along this front as they migrate across the North Pacific. The front is easily monitored with ocean color satellite remote sensing. A change in the position of the TZCF between 1997 and 1998 appears to have altered the spatial distribution of loggerhead turtles. The position and dynamics of the front varied substantially between the 1998 El Niño and the 1999 La Niña. For example, from May to July 1999 the transition zone chlorophyll front (TZCF) remained between about 35°N and 40°N latitude showing very little meandering, whereas in 1998, during the same period, the TZCF exhibited considerable meandering and greater monthly latitudinal movement. Catch rates for albacore were considerably higher in 1998 than in 1999, and we hypothesize that a meandering TZCF creates regions of convergence, which enhances the foraging habitat for apex predators along the front.

  10. 76 FR 63656 - Front Range Resource Advisory Council Meeting Cancellation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-13

    ...LLCOF00000-L18200000-XX0000] Front Range Resource Advisory Council Meeting Cancellation...notice is hereby given that the Front Range Resource Advisory Council meeting scheduled...INFORMATION CONTACT: Tina Brown, Front Range RAC Coordinator, BLM Colorado State...

  11. 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

  12. 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.

  13. 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...

  14. Biological consequences of a cold, stratified, high latitude, glacial ocean

    NASA Astrophysics Data System (ADS)

    Hays, J. D.

    2010-12-01

    Increasing oceanic organic carbon export by improving the efficiency of the oceans biological pump has been invoked as a means to transfer CO2 between atmosphere and ocean during glacial cycles. Although this mechanism is supported by evidence of higher late Pleistocene than Holocene redox-sensitive metal concentrations in deep-sea sediments, evidence of higher glacial primary productivity, to generate greater export, is lacking (Jaccard et al., 2009). This study proposes that glacial cold ocean stratification has profound biological consequences that can resolve this paradox, evidenced by the changing flux of radiolarians from different levels within the water column. Mesopelagic (200-1000m) radiolarians, which are beneficiaries of carbon export, have higher glacial than Holocene flux to northwest Pacific sediments, indicating increased glacial export, in agreement with the redox-sensitive metal data, but glacial epipelagic (0-200m) radiolarian flux is lower than Holocene flux indicating an inhibition of epipelagic production. Modern radiolarian flux patterns, similar to the glacial northwest Pacific, occur only in the strongly stratified Sea of Okhotsk, where a thin (10-20m), summer, nutrient depleted mixed layer is underlain (20 to 150m) by perennially cold (-1 to 0° C) remnant winter water. Radiolarian and zooplankton concentrations in the cold winter layer are low relative to warmer water below (200 and 1000m) (Nimmergut and Abelmann, 2002; Gorbatenko, 1996). This physical and biological stratification generates greater mesopelagic radiolarian flux, dominated by C. davisiana, than epipelagic flux. The similar radiolarian flux pattern in glacial northwest Pacific sediments suggests a similar overlying physical and biological stratification and its greater implied export is probably caused by reduced epipelagic consumption in the cold winter water, rather than increased primary production. High C. davisiana percentages, in glacial high latitude (above 45°) sediments of both hemispheres, indicate the presence of an Okhotsk-like physical and biological stratification. This glacial stratification would have stripped nutrients from a thin sun-drenched mixed layer, reduced epipelagic heterotrophic consumption increasing biological pump efficiency and enhancing mesopelagic heterotrophic consumption, inspite of no increase and possibly a decease of high latitude primary productivity.

  15. Physiology of cold tolerance in the bark beetle, Pityogenes chalcographus and its overwintering in spruce stands.

    PubMed

    Koštál, Vladimír; Miklas, Bo?ek; Doležal, Petr; Rozsypal, Jan; Zahradní?ková, Helena

    2014-04-01

    The seasonal development of physiological features underlying gradual acquisition of relatively high cold tolerance in overwintering adults of the bark beetles, Pityogenes chalcographus was described. Prior to overwintering, the beetles accumulated carbohydrate reserves in the form of glycogen and trehalose. These reserves were partially converted to glycerol during peaking winter so that glycerol concentration reached 1.4M in average, which corresponds to approximately one quarter of the beetle dry mass. Whole body supercooling points decreased from -12.8°C in average at the beginning of dormancy (August) to -26.3°C in average during peaking winter (January). More than 75% of January-collected beetles survived at -5°C for 30days, at -15°C for 60days and more than 40% of them survived at -26°C for 12h. High resistance against inoculation of body fluids with external ice crystals, and low mortality, was observed when January-collected beetles were encased in an ice block for 14days. Thus, the physiological limits of cold tolerance measured at individual level in laboratory were safely sufficient for survival of P. chalcographus at any conceivable cold spell that may occur in Central Europe. In contrast, the field experiment showed that winter survival fluctuated between 23.8% and 69.2% at a population level depending on microclimatic conditions in different altitudes and overwintering locations (standing tree trunk or ground level). The meaning of laboratory-assessed physiological limits of cold tolerance for predictions of population winter survival in the field is discussed. PMID:24607639

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  17. International Symposium on Gaseous and Odour Emissions from Animal Production Facilities, Horsens, Jutland, Denmark 1-4 June, 2003 Ammonia Emissions from Broiler Houses in Kentucky during Winter

    E-print Network

    Kentucky, University of

    , Jutland, Denmark 1-4 June, 2003 Ammonia Emissions from Broiler Houses in Kentucky during Winter Kenneth D. The measurement of ER under cold weather conditions from 8 broiler houses with re-used (`built- up') litter in eight broiler houses representative of Kentucky. A companion paper (Wheeler et al., 2003) also presented

  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.; 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.

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

    E-print Network

    Zhou, Yaoqi

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

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

    E-print Network

    Maxwell, Bruce D.

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

  1. Cold Dark Matter Resuscitated?

    E-print Network

    Martin White; Douglas Scott; Joe Silk; Marc Davis

    1995-08-21

    The Cold Dark Matter (CDM) model has an elegant simplicitly which makes it very predictive, but when its parameters are fixed at their `canonical' values its predictions are in conflict with observational data. There is, however, much leeway in the initial conditions within the CDM framework. We advocate a re-examination of the CDM model, taking into account modest variation of parameters from their canonical values. We find that CDM models with $n=0.8$--0.9 and $h=0.45$--0.50 can fit the available data. Our ``best fit'' CDM model has $n=0.9$, $h=0.45$ and $C_2^{T}/C_2^{S}=0.7$. We discuss the current state of observations which could definitely rule out this model.

  2. Hot Planet - Cold Comfort

    NSDL National Science Digital Library

    This page features videos from the "Hot Planet- Cold Comfort" television episode, related website articles and a student activity. The videos explore how the Gulf Stream conveyor belt may shut down; how Arctic river runoff and Alaskan glacial melt are freshening the oceans; and how ocean sediments and ice cores are being studied to understand the Little Ice Age. The videos total approximately one hour in length. The website articles explore the Little Ice Age; how the Arctic functions as a global thermostat, affecting global weather patterns; and great moments in climate change. The student activity is about light absorbtion. The site also contains a challenge activity to find details in a painting that depict Little Ice Age living conditions.

  3. Monitoring the vaccine cold chain

    Microsoft Academic Search

    E Cheriyan

    1993-01-01

    Maintaining the vaccine cold chain is an essential part of a successful immunisation programme. A continuous electronic temperature monitor helped to identify breaks in the cold chain in the community and the study led to the issue of proper guidelines and replacement of faulty equipment.

  4. Encyclopedia of the Cold War

    Microsoft Academic Search

    Dijk van R

    2008-01-01

    Between 1945 and 1991, tension between the USA, its allies, and a group of nations led by the USSR, dominated world politics. This period was called the Cold War – a conflict that stopped short to a full-blown war. Benefiting from the recent research of newly open archives, the Encyclopedia of the Cold War discusses how this state of perpetual

  5. Tip model of cold fission

    Microsoft Academic Search

    F. Gönnenwein; B. Börsig

    1991-01-01

    Cold fission is defined to be the limiting case of nuclear fission where virtually all of the available energy is converted into the total kinetic energy of the fragments. The fragments have, therefore, to be born in or at least close to their respective ground states. Starting from the viewpoint that cold fission corresponds to most compact scission configurations, energy

  6. 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.

  7. 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

  8. Calcium addition at the Hubbard Brook Experimental Forest increases the capacity for stress tolerance and carbon capture in red spruce ( Picea rubens ) trees during the cold season

    Microsoft Academic Search

    Paul G. Schaberg; Rakesh Minocha; Stephanie Long; Joshua M. Halman; Gary J. Hawley; Christopher Eagar

    Red spruce (Picea rubens Sarg.) trees are uniquely vulnerable to foliar freezing injury during the cold season (fall and winter), but are also capable\\u000a of photosynthetic activity if temperatures moderate. To evaluate the influence of calcium (Ca) addition on the physiology\\u000a of red spruce during the cold season, we measured concentrations of foliar polyamines and free amino acids (putative stress-protection

  9. Numerical Modeling and Spatial Moment Analysis of Thermal Fronts in a Coupled Fracture-Skin-Matrix System

    Microsoft Academic Search

    N. NatarajanG; G. Suresh Kumar

    2011-01-01

    In this study, the behavior of thermal fronts along the fracture is studied in the presence of fracture-skin in a coupled\\u000a fracture-matrix system. Cold water is injected into the fracture, which advances gradually towards production well, while\\u000a extracting heat from the surrounding reservoir matrix. The heat conduction into the fracture-skin and the rock-matrix from\\u000a the high permeability fracture is assumed

  10. Hydrological drought in cold climates: new drought types

    NASA Astrophysics Data System (ADS)

    van Lanen, Henny A. J.; van Loon, Anne F.; Ploum, Stefan; Laaha, Gregor; Parajka, Juraj; Garnier, Emmanuel

    2014-05-01

    The previous winter (2013-2014) was warm and dry in many regions of Europe, leading to serious problems in water supply in for example Kosovo. This winter was not an exception. Analyses of drought-related impacts on nature and society indicate that not all drought impacts occur in summer, during periods with below-normal rainfall and connected heat waves. We found that several drought impacts are a consequence of anomalies in winter-related processes, such as snow accumulation and melt. The hydrological drought typology (Van Loon & Van Lanen, 2012) was developed based on analysis of the processes underlying drought propagation in catchments in Norway, Czech Republic and Slovakia. In this typology, two drought types were distinguished that are caused by anomalous winter processes: cold snow season drought and warm snow season drought. In a recent study in the Alpine region, however, we found drought events that could not be classified into one of the types of the existing hydrological drought typology. We could reveal the processes underlying these drought events with further detailed analysis of an extensive dataset of observations and simulations of hydrometeorological variables for a large number of catchments in Austria. In this paper we present two new hydrological drought types related to snow and glacier melt. We discuss the processes underlying these drought types and show that besides precipitation, temperature plays an important role. Furthermore, we discuss the differences between hydrological droughts in the Alpine region and the previously studied regions in North and Central Europe, and investigate the relationship with the impacts of hydrological drought, both in the ancient (1500-1950) and in the recent past (1970-2010). Van Loon, A.F., and Van Lanen, H.A.J.: A process-based typology of hydrological drought, Hydrology and Earth System Science, 16, p. 1915-1946, doi: 10.5194/hess-16-1915-2012, 2012

  11. The life cycle of thunderstorm gust fronts as viewed with Doppler radar and rawinsonde data

    NASA Technical Reports Server (NTRS)

    Wakimoto, R. M.

    1982-01-01

    This paper presents the time-dependent analysis of the thunderstorm gust front with the use of Project NIMROD data. RHI cross sections of reflectivity and Doppler velocity are constructed to determine the entire vertical structure. The life cycle of the gust front is divided into four stages: (1) the formative stage; (2) the early mature stage; (3) the late mature stage; and (4) the dissipation stage. A new finding is a horizontal roll detected in the reflectivity pattern resulting from airflow that is deflected upward by the ground, while carrying some of the smaller precipitation ahead of the main echo core of the squall line. This feature is called a 'precipitation roll'. As determined from rawinsonde data, the cold air behind the gust front accounts for the observed surface pressure rise. Calculations confirm that the collision of two fluids produce a nonhydrostatic pressure at the leading edge of the outflow. The equation governing the propagation speed of a density current accurately predicts the movement of the gust front.

  12. Simulation of idealized warm fronts and life cycles of cirrus clouds

    NASA Astrophysics Data System (ADS)

    Bense, Vera; Spichtinger, Peter

    2013-04-01

    One of the generally accepted formation mechanisms of cirrus clouds is connected to warm fronts. As the warm air glides over the cold air mass, it cools through adiabatic expansion and reaches ice supersaturation that eventually leads to the formation of ice clouds. Within this work, the EULAG model (see e.g. Prusa et al., 2008) was used to study the formation and life cycles of cirrus clouds in idealized 2-dimensional simulations. The microphysical processes were modelled with the double-moment bulk scheme of Spichtinger and Gierens (2009), which describes homogeneous and heterogeneous nucleation. In order to represent the gradual gliding of the air along the front, a ramp was chosen as topography. The sensibility of cloud formation to different environmental conditions such as wind shear, aerosol distribution and slope of the front was analyzed. In case of cirrus cloud formation its persistence after the front was studied as well as the change in microphysical properties such as ice crystal number concentrations. References: Prusa, J.M., P.K. Smolarkiewicz, A.A. Wyszogrodzki, 2008: EULAG, a computational model for multiscale flows. Computers and Fluids, doi:10.1016/j.compfluid.2007.12.001. Spichtinger, P., K. M. Gierens, 2009: Modelling of cirrus clouds - Part 1a: Model description and validation, Atmos. Chem. Phys., 9, 685-706.

  13. Synoptic maps of temperature and velocity within the Subantarctic Front south of Australia

    NASA Astrophysics Data System (ADS)

    Tracey, K. L.; Watts, D. R.; Meinen, C. S.; Luther, D. S.

    2006-10-01

    From April 1995 to March 1997 a 450-km array of inverted echo sounders, horizontal electric field recorders, and current meters measured the horizontal and vertical structure of the current, temperature, and salinity fields associated with the Subantarctic Front (SAF) south of Australia. Synoptic maps of the temperature and velocity fields often show the SAF divided into two zonally separated jets, which are also found in the mean. These jets were in close proximity yet directed toward different azimuths. The daily maps also show that the SAF often flowed as a single strong jet, during which times it underwent vigorous meandering, with crest-to-trough meridional distances ˜250 km. These meanders stalled within the array and contorted to form "S"-shaped paths. In one case a cold-core ring was formed. Propagating meanders have periods of 20-70 days, wavelengths of 240-420 km, and phase speeds of 12-6 km d-1. Deep currents reveal strong cyclones and anticyclones propagating primarily eastward through the array beneath the meandering jet. Thus, at times the deep flow is aligned with the upper flow, whereas at other times, significant barotropic flows cross the upper front. Occasionally, the northern Polar Front was also found within the array. The observed variability illustrates how the interaction of a meandering current with transient features such as meanders and eddies makes the identification of a front difficult when a single isotherm or isopycnal is utilized as the definition.

  14. Coarsening to Chaos-Stabilized Fronts

    E-print Network

    Ka-Fai Poon; Ralf W. Wittenberg

    2010-06-01

    We investigate a model for pattern formation in the presence of Galilean symmetry proposed by Matthews and Cox [Phys.\\ Rev.\\ E \\textbf{62}, R1473 (2000)], which has the form of coupled generalized Burgers and Ginzburg-Landau-type equations. With only the system size $L$ as a parameter, we find distinct "small-$L$" and "large-$L$" regimes exhibiting clear differences in their dynamics and scaling behavior. The long-time statistically stationary state contains a single $L$-dependent front, stabilized globally by spatiotemporally chaotic dynamics localized away from the front. For sufficiently large domains, the transient dynamics include a state consisting of several viscous shock-like structures which coarsens gradually, before collapsing to a single front when one front absorbs the others.

  15. Some Hadronic Properties from Light Front Holography

    E-print Network

    Alfredo Vega; Ivan Schmidt; Thomas Gutsche; Valery E. Lyubovitskij

    2011-07-27

    Using ideas from Light Front Holography, we discuss the calculation of hadronic properties. In this talk I will pay special attention to hadronic masses and the nucleon helicity-independent generalized parton distributions of quarks in the zero skewness case

  16. Turbulent transport model of wind shear in thunderstorm gust fronts and warm fronts

    NASA Technical Reports Server (NTRS)

    Lewellen, W. S.; Teske, M. E.; Segur, H. C. O.

    1978-01-01

    A model of turbulent flow in the atmospheric boundary layer was used to simulate the low-level wind and turbulence profiles associated with both local thunderstorm gust fronts and synoptic-scale warm fronts. Dimensional analyses of both type fronts provided the physical scaling necessary to permit normalized simulations to represent fronts for any temperature jump. The sensitivity of the thunderstorm gust front to five different dimensionless parameters as well as a change from axisymmetric to planar geometry was examined. The sensitivity of the warm front to variations in the Rossby number was examined. Results of the simulations are discussed in terms of the conditions which lead to wind shears which are likely to be most hazardous for aircraft operations.

  17. Asymmetry of Columbia River tidal plume fronts

    NASA Astrophysics Data System (ADS)

    Jay, David A.; Pan, Jiayi; Orton, Philip M.; Horner-Devine, Alexander R.

    2009-10-01

    Columbia River tidal plume dynamics can be explained in terms of two asymmetries related to plume-front depth and internal wave generation. These asymmetries may be an important factor contributing to the observed greater primary productivity and phytoplankton standing crop on the Washington shelf. The tidal plume (the most recent ebb outflow from the estuary) is initially supercritical with respect to the frontal internal Froude number FR on strong ebbs. It is separated from the rotating plume bulge by a front, whose properties are very different under upwelling vs. downwelling conditions. Under summer upwelling conditions, tidal plume fronts are sharp and narrow (< 20-50 m wide) on their upwind or northern side and mark a transition from supercritical to subcritical flow for up to 12 h after high water. Such sharp fronts are a source of turbulent mixing, despite the strong stratification. Because the tidal plume may overlie newly upwelled waters, these fronts can mix nutrients into the plume. Symmetry would suggest that there should be a sharp front south of the estuary mouth under summer downwelling conditions. Instead, the downwelling tidal plume front is usually diffuse on its upstream side. Mixing is weaker, and the water masses immediately below are low in nutrients. There is also an upwelling-downwelling asymmetry in internal wave generation. During upwelling and weak wind conditions, plume fronts often generate trains of non-linear internal waves as they transition from a supercritical to a subcritical state. Under downwelling conditions, internal wave release is less common and the waves are less energetic. Furthermore, regardless of wind conditions, solition formation almost always begins on the south side of the plume so that the front "unzips" from south to north. This distinction is important, because these internal waves contribute to vertical mixing in the plume bulge and transport low-salinity water across the tidal plume into the plume bulge. FR and plume depth are key parameters in distinguishing the upwelling and downwelling situations, and these two asymmetries can be explained in terms of potential vorticity conservation. The divergence of the tidal outflow after it leaves the estuary embeds relative vorticity in the emerging tidal plume water mass. This vorticity controls the transition of the tidal plume front to a subcritical state and consequently the timing and location of internal wave generation by plume fronts.

  18. Small-scale zooplankton aggregations at the front of a Kuroshio warm-core ring

    NASA Astrophysics Data System (ADS)

    Yamamoto, Tamiji; Nishizawa, Satoshi

    1986-11-01

    A Longhurst-Hardy Plankton Recorder was used to study the small-scale zooplankton distribution across the front of a Kuroshio warm-core ring in June 1979. Zooplankton were strongly aggregated in the frontal region; patches of zooplankton and phytoplankton were spatially separated. A major part of the zooplankton assemblage consisted of neritic forms such as cladocerans and indicator species of the cold Oyashio water. This implies that lateral entrainment of coastal waters, which is directly influenced by the Oyashio, was an important factor in the formation of the aggregations at the Kuroshio warm-core ring front. Variation in the distribution of abundance peaks of individual zooplankton species was also observed. Futhermore, zooplankton showed more intensive non-randomness (aggregation) than phytoplankton and non-motile euphausiid's eggs. Thus, biological processes, such as motility and prey-predator interaction, also appeared to be regulating the patchiness.

  19. Shape of the Quantum Diffusion Front

    Microsoft Academic Search

    Jianxin Zhong; R. B. Diener; Daniel A. Steck; Windell H. Oskay; Mark G. Raizen; E. Ward Plummer; Zhenyu Zhang; Qian Niu

    2001-01-01

    We show that quantum diffusion has well-defined front shape. After an initial transient, the wave packet front (tails) is described by a stretched exponential P\\\\(x,t\\\\) = A\\\\(t\\\\)exp\\\\(-\\\\|x\\/w\\\\|gamma\\\\), with 1

  20. Solar cycle modulation of the ENSO impact on the winter climate of East Asia

    NASA Astrophysics Data System (ADS)

    Zhou, Qun; Chen, Wen; Zhou, Wen

    2013-06-01

    This study examines how the East Asian winter climate response to the El Niño-Southern Oscillation (ENSO) varies with the 11-year solar cycle. The results indicate that the ENSO and East Asian climate relationship is robust and significant during winters with low solar (LS) activity, with evident warming in the lower troposphere over East Asia, which can be closely linked to the decreased pressure gradient between the cold Eurasian continent and the warm Pacific. Moreover, during the LS and El Niño winters, there is a typical rainfall response in Southeast Asia, with wet conditions over South China and dry conditions over the Philippines, Borneo, Celebes, and Sulawesi, which can be explained by the anticyclone over the western North Pacific (WNP). However, during high solar activity winters, both the surface temperature and rainfall anomalies are much less closely associated with the ENSO. The possible mechanism for this solar modulation of the ENSO-related East Asian climate anomalies may be the change in the tropospheric circulation with the ENSO in both tropical and extratropical regions. Particularly, in the LS cases, an anomalous WNP anticyclone is intensified and a noticeable cyclone occupies northern Northeast Asia, resulting from the changing location and strength of the large-scale Walker circulation induced by the more pronounced sea surface temperature anomalies associated with the ENSO. Further investigation with long historic data confirms that the relationship between the ENSO and the East Asian winter climate anomalies depends on the phases of 11 year solar cycle, with enhanced East Asian climate variation during the LS winters.