Limnological and climatic environments at Upper Klamath Lake, Oregon during the past 45 000 years

USGS Publications Warehouse

Bradbury, J.P.; Colman, Steven M.; Dean, W.E.

2004-01-01

Upper Klamath Lake, in south-central Oregon, contains long sediment records with well-preserved diatoms and lithological variations that reflect climate-induced limnological changes. These sediment archives complement and extend high resolution terrestrial records along a north-south transect that includes areas influenced by the Aleutian Low and Subtropical High, which control both marine and continental climates in the western United States. The longest and oldest core collected in this study came from the southwest margin of the lake at Caledonia Marsh, and was dated by radiocarbon and tephrochronology to an age of about 45 ka. Paleolimnological interpretations of this core, based upon geochemical and diatom analyses, have been augmented by data from a short core collected from open water environments at nearby Howards Bay and from a 9-m core extending to 15 ka raised from the center of the northwestern part of Upper Klamath Lake. Pre- and full-glacial intervals of the Caledonia Marsh core are characterized and dominated by lithic detrital material. Planktic diatom taxa characteristic of cold-water habitats (Aulacoseira subarctica and A. islandica) alternate with warm-water planktic diatoms (A. ambigua) between 45 and 23 ka, documenting climate changes at millennial scales during oxygen isotope stage (OIS) 3. The full-glacial interval contains mostly cold-water planktic, benthic, and reworked Pliocene lacustrine diatoms (from the surrounding Yonna Formation) that document shallow water conditions in a cold, windy environment. After 15 ka, diatom productivity increased. Organic carbon and biogenic silica became significant sediment components and diatoms that live in the lake today, indicative of warm, eutrophic water, became prominent. Lake levels fell during the mid-Holocene and marsh environments extended over the core site. This interval is characterized by high levels of organic carbon from emergent aquatic vegetation (Scirpus) and by the Mazama ash (7.55 ka), generated by the eruption that created nearby Crater Lake. For a brief time the ash increased the salinity of Upper Klamath Lake. High concentrations of molybdenum, arsenic, and vanadium indicate that Caledonia Marsh was anoxic from about 7 to 5 ka. After the mid-Holocene, shallow, but open-water environments returned to the core site. The sediments became dominated (>80%) by biogenic silica. The open-water cores show analogous but less extreme limnological and climatic changes more typical of mid-lake environments. Millennial-scale lake and climate changes during OIS 3 at Upper Klamath Lake contrast with a similar record of variation at Owens Lake, about 750 km south. When Upper Klamath Lake experienced cold-climate episodes during OIS 3, Owens Lake had warm but wet episodes; the reverse occurred during warmer intervals at Upper Klamath Lake. Such climatic alternations apparently reflect the variable position and strength of the Aleutian Low during the mid-Wisconsin.

Measuring Race and Gender Differences in Undergraduate Students' Perceptions of Campus Climate and Intentions to Leave College: An Analysis in Black and White

ERIC Educational Resources Information Center

Strayhorn, Terrell L.

2013-01-01

Student perceptions of campus climate environments and intentions to leave college were examined for 391 participants. Differences by race were found for perceptions of the campus climate being cold and uncaring and for expectations to encounter racism in college. Perceptions of campus climate were related to African American students' intent to…

OIL SPILL RESPONSE SCENARIOS FOR REMOTE ARCTIC ENVIRONMENTS

EPA Science Inventory

Special problems occur during oil spill cleanup in remote inland areas in cold climates. In Alaska these problems result from the harsh climate, the unusual terrain features, and the special problems of spills along swift rivers. The analysis begins with a description of the envi...

Soil Crystallinity As a Climate Indicator: Field Experiments on Earth and Mars

NASA Technical Reports Server (NTRS)

Horgan, Briony; Scudder, Noel; Rampe, Elizabeth; Rutledge, Alicia

2016-01-01

Soil crystallinity is largely determined by leaching rates, as high leaching rates favor the rapid precipitation of short order or poorly-crystalline phases like the aluminosilicate allophane. High leaching rates can occur due to high precipitation rates, seasonal monsoons, or weathering of glass, but are also caused by the rapid onset of seasonal melting of snow and ice in cold environments. Thus, cold climate soils are commonly dominated by poorly crystalline phases, which mature into kaolin minerals over time. Thus, we hypothesize that, in some contexts, soils with high abundances of poorly crystalline phases could indicate formation under cold climatic conditions. This model could be helpful in interpreting the poorly-constrained paleoclimate of ancient Mars, as the crystallinity of ancient soils and soil-derived sediments appears to be highly variable in time and space. While strong signatures of crystalline phyllosilicates have been identified in possible ancient paleosols on Mars, Mars Science Laboratory rover investigations of diverse ancient sediments at Gale Crater has shown that they can contain very high abundances (40-50 wt%) of poorly crystalline phases. We hypothesize that these poorly crystalline phases could be the result of weathering by ice/snow melt, perhaps providing support for sustained cold climates on early Mars punctuated by more limited warm climates. Furthermore, such poorly crystalline soils could be highly fertile growth media for future human exploration and colonization on Mars. To test this hypothesis, we are currently using rover-like instrumentation to investigate the mineralogy and chemistry of weathering products generated by snow and ice melt in a Mars analog alpine environment: the glaciated Three Sisters volcanic complex in central Oregon. Alteration in this glacial environment generates high abundances of poorly crystalline phases, many of which have compositions distinct from those identified in previous terrestrial investigations, and perhaps more similar to poorly crystalline phases identified on Mars.

Protistan Diversity in the Arctic: A Case of Paleoclimate Shaping Modern Biodiversity?

PubMed Central

Stoeck, Thorsten; Kasper, Jennifer; Bunge, John; Leslin, Chesley; Ilyin, Valya; Epstein, Slava

2007-01-01

Background The impact of climate on biodiversity is indisputable. Climate changes over geological time must have significantly influenced the evolution of biodiversity, ultimately leading to its present pattern. Here we consider the paleoclimate data record, inferring that present-day hot and cold environments should contain, respectively, the largest and the smallest diversity of ancestral lineages of microbial eukaryotes. Methodology/Principal Findings We investigate this hypothesis by analyzing an original dataset of 18S rRNA gene sequences from Western Greenland in the Arctic, and data from the existing literature on 18S rRNA gene diversity in hydrothermal vent, temperate sediments, and anoxic water column communities. Unexpectedly, the community from the cold environment emerged as one of the richest observed to date in protistan species, and most diverse in ancestral lineages. Conclusions/Significance This pattern is consistent with natural selection sweeps on aerobic non-psychrophilic microbial eukaryotes repeatedly caused by low temperatures and global anoxia of snowball Earth conditions. It implies that cold refuges persisted through the periods of greenhouse conditions, which agrees with some, although not all, current views on the extent of the past global cooling and warming events. We therefore identify cold environments as promising targets for microbial discovery. PMID:17710128

Outdoor comfort of pedestrians in cities

Treesearch

Edward Arens; Donald Ballanti

1977-01-01

The outdoor comfort of pedestrians has been neglected by architects and planners because of difficulties in determining comfortable and uncomfortable climatic conditions and predicting the climatic characteristics of a planned urban site. Available information on comfort in a cold environment is summarized. The mechanical effects of wind on comfort are better...

Effect of cold indoor environment on physical performance of older women living in the community.

PubMed

Lindemann, Ulrich; Oksa, Juha; Skelton, Dawn A; Beyer, Nina; Klenk, Jochen; Zscheile, Julia; Becker, Clemens

2014-07-01

the effects of cold on older persons' body and mind are not well documented, but with an increased number of older people with decreasing physical performance, these possible effects need to be understood. to investigate the effect of cold indoor environment on physical performance of older women. cross-sectional experimental study with two test conditions. movement laboratory in a climate chamber. eighty-eight community-dwelling, cognitively unimpaired older women (mean age 78 years). participants were exposed to moderately cold (15°C) and warm/normal (25°C) temperature in a climate chamber in random order with an interval of 1 week. The assessment protocol included leg extensor power (Nottingham Power Rig), sit-to-stand performance velocity (linear encoder), gait speed, walk-ratio (i.e. step length/cadence on an instrumented walk way), maximal quadriceps and hand grip strength. physical performance was lower in 15°C room temperature compared with 25°C room temperature for leg extensor power (P < 0.0001), sit-to-stand performance velocity (P < 0.0001), gait speed (P < 0.0001), walk-ratio (P = 0.016) and maximal quadriceps strength (P = 0.015), but not for hand grip strength. in healthy older women a moderately cold indoor environment decreased important physical performance measures necessary for independent living. © The Author 2014. Published by Oxford University Press on behalf of the British Geriatrics Society. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Formation of Valley Networks in a Cold and Icy Early Mars Climate: Predictions for Erosion Rates and Channel Morphology

NASA Astrophysics Data System (ADS)

Cassanelli, J.

2017-12-01

Mars is host to a diverse array of valley networks, systems of linear-to-sinuous depressions which are widely distributed across the surface and which exhibit branching patterns similar to the dendritic drainage patterns of terrestrial fluvial systems. Characteristics of the valley networks are indicative of an origin by fluvial activity, providing among the most compelling evidence for the past presence of flowing liquid water on the surface of Mars. Stratigraphic and crater age dating techniques suggest that the formation of the valley networks occurred predominantly during the early geologic history of Mars ( 3.7 Ga). However, whether the valley networks formed predominantly by rainfall in a relatively warm and wet early Mars climate, or by snowmelt and episodic rainfall in an ambient cold and icy climate, remains disputed. Understanding the formative environment of the valley networks will help distinguish between these warm and cold end-member early Mars climate models. Here we test a conceptual model for channel incision and evolution under cold and icy conditions with a substrate characterized by the presence of an ice-free dry active layer and subjacent ice-cemented regolith, similar to that found in the Antarctic McMurdo Dry Valleys. We implement numerical thermal models, quantitative erosion and transport estimates, and morphometric analyses in order to outline predictions for (1) the precise nature and structure of the substrate, (2) fluvial erosion/incision rates, and (3) channel morphology. Model predictions are compared against morphologic and morphometric observational data to evaluate consistency with the assumed cold climate scenario. In the cold climate scenario, the substrate is predicted to be characterized by a kilometers-thick globally-continuous cryosphere below a 50-100 meter thick desiccated ice-free zone. Initial results suggest that, with the predicted substrate structure, fluvial channel erosion and morphology in a cold early Mars climate exposed to episodic high temperatures will not differ significantly from that in a warm climate. The fundamentally different hydrologic conditions are likely to influence other aspects of valley network morphology and morphometry including: drainage density, drainage pattern, and stream orders.

Late Noachian Climate Of Mars: Constraints From Valley Network System Formation Times And The Intermittencies (Episodic/Periodic And Punctuated).

NASA Astrophysics Data System (ADS)

Head, James

2017-04-01

Formation of Late Noachian-Early Hesperian (LN-EH) valley network systems (VNS) signaled the presence of warm/wet conditions generating several hypotheses for climates permissive of these conditions. To constrain options for the ambient Noachian climate, we examine estimates for time required to carve channels/deltas and total duration implied by plausible intermittencies. Formation Times for VN, OBL, Deltas, Fans: A synthesis of required timescales show that even with the longest estimated continuous duration of VN formation/intermittencies, total time to carve the VN does not exceed 106 years, <˜0.25% of the total Noachian. Intermittency/episodicity assumptions are climate-model dependent (e.g., most workers use Earth-like fluvial activity and intermittency). Noachian-Early Hesperian Climate Models: 1) Warm and wet/semiarid/arid climate: Sustained background MAT >273 K, hydrological system vertically integrated, and rainfall occurs to recharge the aquifer. Two subtypes: a) "Rainfall/Fluvial Erosion-Dominated Warm and Wet Model": "Rainfall and surface runoff" persist throughout Noachian to explain crater degradation, and a LN-EH short rapidly ending terminal epoch. b) "Recharge Evaporation/Evaporite Dominated Warm and Wet Model": Sustained period of equatorial/mid-latitude precipitation and a vertically integrated hydrological system driven by evaporative upwelling and fluctuating shallow water table playa environments account for sulfate evaporate environments at Meridiani Planum. Sustained temperatures >273 K are required for extended periods (107-108 years). 2) Cold and icy climate: Sustained background temperatures extremely low (MAT ˜225 K), cryosphere is globally continuous, hydrological system is horizontally stratified, separating groundwater system from surface; no combination of spin-axis/orbital perturbations can raise MAT to 273 K. Adiabatic cooling effects transfer water to high altitudes, leading to "Late Noachian Icy Highlands Model". VNS cannot form in this nominal climate environment without special circumstances (e.g., impacts or volcanic eruptions elevate of temperatures by >˜50 K to induce melting and fluvial/lacustrine activity). 3) Cold and Icy climate warmed by greenhouse gases: The climate is sustained cold/icy model, but greenhouse gases of unspecified nature/amount/duration elevate MAT by several tens of Kelvins (say 25 K, to MAT 250 K), bringing annual temperature range into the realm where peak seasonal temperatures (PST) exceed 273 K. In this climate environment, analogous to the Antarctic Dry Valleys, seasonal summer temperatures above 273 K are sufficient to melt snow/ice and form fluvial and lacustrine features, but MAT is well below 273 K (253 K). Fluvial systems driven by episodic/periodic intermittency typically involve short intermittency time-scales (10-106 years) but require a warm climate (MAT >273 K) to be sustained for >0.4 x 109 years. Fluvial systems driven by punctuated intermittency typically involve short duration time-scales (10-105 years) but only require a warm climate (MAT >273 K) for the very short duration of the climatic impact of the punctuated event (102-105 years). We conclude that a cold and icy background climate with punctuated intermittency of warming and melting events is consistent with: 1) the estimated durations of continuous VN formation (<105 years) and 2) VN system estimated recurrence rates (106-107 years).

Slow climate velocities of mountain streams portend their role as refugia for cold-water biodiversity

USGS Publications Warehouse

Isaak, Daniel J.; Young, Michael K; Luce, Charles H; Hostetler, Steven W.; Wengerd, Seth J.; Peterson, Erin E.; Ver Hoef, Jay; Groce, Matthew C.; Horan, Dona L.; Nagel, David E.

2016-01-01

The imminent demise of montane species is a recurrent theme in the climate change literature, particularly for aquatic species that are constrained to networks and elevational rather than latitudinal retreat as temperatures increase. Predictions of widespread species losses, however, have yet to be fulfilled despite decades of climate change, suggesting that trends are much weaker than anticipated and may be too subtle for detection given the widespread use of sparse water temperature datasets or imprecise surrogates like elevation and air temperature. Through application of large water-temperature databases evaluated for sensitivity to historical air-temperature variability and computationally interpolated to provide high-resolution thermal habitat information for a 222,000-km network, we estimate a less dire thermal plight for cold-water species within mountains of the northwestern United States. Stream warming rates and climate velocities were both relatively low for 1968–2011 (average warming rate = 0.101 °C/decade; median velocity = 1.07 km/decade) when air temperatures warmed at 0.21 °C/decade. Many cold-water vertebrate species occurred in a subset of the network characterized by low climate velocities, and three native species of conservation concern occurred in extremely cold, slow velocity environments (0.33–0.48 km/decade). Examination of aggressive warming scenarios indicated that although network climate velocities could increase, they remain low in headwaters because of strong local temperature gradients associated with topographic controls. Better information about changing hydrology and disturbance regimes is needed to complement these results, but rather than being climatic cul-de-sacs, many mountain streams appear poised to be redoubts for cold-water biodiversity this century.

Slow climate velocities of mountain streams portend their role as refugia for cold-water biodiversity

PubMed Central

Isaak, Daniel J.; Young, Michael K.; Luce, Charles H.; Hostetler, Steven W.; Wenger, Seth J.; Peterson, Erin E.; Ver Hoef, Jay M.; Groce, Matthew C.; Horan, Dona L.; Nagel, David E.

2016-01-01

The imminent demise of montane species is a recurrent theme in the climate change literature, particularly for aquatic species that are constrained to networks and elevational rather than latitudinal retreat as temperatures increase. Predictions of widespread species losses, however, have yet to be fulfilled despite decades of climate change, suggesting that trends are much weaker than anticipated and may be too subtle for detection given the widespread use of sparse water temperature datasets or imprecise surrogates like elevation and air temperature. Through application of large water-temperature databases evaluated for sensitivity to historical air-temperature variability and computationally interpolated to provide high-resolution thermal habitat information for a 222,000-km network, we estimate a less dire thermal plight for cold-water species within mountains of the northwestern United States. Stream warming rates and climate velocities were both relatively low for 1968–2011 (average warming rate = 0.101 °C/decade; median velocity = 1.07 km/decade) when air temperatures warmed at 0.21 °C/decade. Many cold-water vertebrate species occurred in a subset of the network characterized by low climate velocities, and three native species of conservation concern occurred in extremely cold, slow velocity environments (0.33–0.48 km/decade). Examination of aggressive warming scenarios indicated that although network climate velocities could increase, they remain low in headwaters because of strong local temperature gradients associated with topographic controls. Better information about changing hydrology and disturbance regimes is needed to complement these results, but rather than being climatic cul-de-sacs, many mountain streams appear poised to be redoubts for cold-water biodiversity this century. PMID:27044091

Adaptation to seasonality and the winter freeze

PubMed Central

Preston, Jill C.; Sandve, Simen R.

2013-01-01

Flowering plants initially diversified during the Mesozoic era at least 140 million years ago in regions of the world where temperate seasonal environments were not encountered. Since then several cooling events resulted in the contraction of warm and wet environments and the establishment of novel temperate zones in both hemispheres. In response, less than half of modern angiosperm families have members that evolved specific adaptations to cold seasonal climates, including cold acclimation, freezing tolerance, endodormancy, and vernalization responsiveness. Despite compelling evidence for multiple independent origins, the level of genetic constraint on the evolution of adaptations to seasonal cold is not well understood. However, the recent increase in molecular genetic studies examining the response of model and crop species to seasonal cold offers new insight into the evolutionary lability of these traits. This insight has major implications for our understanding of complex trait evolution, and the potential role of local adaptation in response to past and future climate change. In this review, we discuss the biochemical, morphological, and developmental basis of adaptations to seasonal cold, and synthesize recent literature on the genetic basis of these traits in a phylogenomic context. We find evidence for multiple genetic links between distinct physiological responses to cold, possibly reinforcing the coordinated expression of these traits. Furthermore, repeated recruitment of the same or similar ancestral pathways suggests that land plants might be somewhat pre-adapted to dealing with temperature stress, perhaps making inducible cold traits relatively easy to evolve. PMID:23761798

The role of cold cues at different life stages on germination and flowering phenology.

PubMed

Rubin, Matthew J; Friedman, Jannice

2018-04-23

The timing of major phenological transitions is critical to lifetime fitness, and life history theory predicts differences for annual and perennial plants. To correctly time these transitions, many plants rely on environmental cues such as exposure to extended periods of cold, which may occur at different stages throughout their lifetime. We studied the role of cold at different life stages, by jointly exposing seed (stratification) and rosettes (vernalization) to cold. We used 23 populations of Mimulus guttatus, which vary from annuals to perennials, and investigated how cold at one or both stages affected germination, flowering, growth, and biomass. We found that stratification and vernalization interact to affect life cycle transitions, and that cold at either stage could synchronize flowering phenology. For perennials, either stratification or vernalization is necessary for maximum flowering. We also found that germination timing covaried with later traits. Moreover, plants from environments with dissimilar climates displayed different phenological responses to stratification or vernalization. In general, cold is more important for seed germination in annuals and plants from environments with warm temperatures and variable precipitation. In contrast, cold is more important for flowering in perennials: it accelerates flowering in plants from lower precipitation environments, and it increases flowering proportion in plants from cooler, more stable precipitation environments. We discuss our findings in the context of the variable environments plants experience within a population and the variation encountered across the biogeographic native range of the species. © 2018 Botanical Society of America.

The I.A.G. / A.I.G. SEDIBUD (Sediment Budgets in Cold Environments) Programme: Current and future activities

NASA Astrophysics Data System (ADS)

Beylich, Achim A.; Lamoureux, Scott; Decaulne, Armelle

2013-04-01

Projected climate change in cold regions is expected to alter melt season duration and intensity, along with the number of extreme rainfall events, total annual precipitation and the balance between snowfall and rainfall. Similarly, changes to the thermal balance are expected to reduce the extent of permafrost and seasonal ground frost and increase active layer depths. These effects will undoubtedly change surface environments in cold regions and alter the fluxes of sediments, nutrients and solutes, but the absence of quantitative data and coordinated geomorphic process monitoring and analysis to understand the sensitivity of the Earth surface environment is acute in cold climate environments. The International Association of Geomorphologists (I.A.G. / A.I.G. ) SEDIBUD (Sediment Budgets in Cold Environments) Programme was formed in 2005 to address this existing key knowledge gap. SEDIBUD currently has about 400 members worldwide and the Steering Committee of this international programme is composed of ten scientists from eight different countries: Achim A. Beylich (Chair) (Norway), Armelle Decaulne (Secretary) (France), John C. Dixon (USA), Scott F. Lamoureux (Vice-Chair) (Canada), John F. Orwin (Canada), Jan-Christoph Otto (Austria), Irina Overeem (USA), Thorsteinn Sæmundsson (Iceland), Jeff Warburton (UK) and Zbigniew Zwolinski (Poland). The central research question of this global group of scientists is to: Assess and model the contemporary sedimentary fluxes in cold climates, with emphasis on both particulate and dissolved components. Initially formed as European Science Foundation (ESF) Network SEDIFLUX (Sedimentary Source-to-Sink Fluxes in Cold Environments) (2004 - ), SEDIBUD has further expanded to a global group of researchers with field research sites located in polar and alpine regions in the northern and southern hemisphere. Research carried out at each of the close to 50 defined SEDIBUD key test sites varies by programme, logistics and available resources, but typically represent interdisciplinary collaborations of geomorphologists, hydrologists, ecologists, permafrost scientists and glaciologists. SEDIBUD has developed manuals and protocols (SEDIFLUX Manual, available online, see below) with a key set of primary surface process monitoring and research data requirements to incorporate results from these diverse projects and allow coordinated quantitative analysis across the programme. Defined SEDIBUD key test sites provide data on annual climate conditions, total discharge and particulate and dissolved fluxes (yields) as well as information on other relevant surface processes. A number of selected key test sites is providing high-resolution data on climate conditions, runoff and sedimentary fluxes (yields), which in addition to the annual data contribute to the SEDIBUD metadata database. Comparable datasets from different SEDIBUD key test sites are integrated and analysed to address key research questions as defined in the SEDIBUD objective (available online, see below). Defined SEDIBUD key tasks for the coming years include (i) The continued generation and compilation of comparable longer-term datasets on contemporary sedimentary fluxes and sediment yields from SEDIBUD key test sites worldwide, (ii) The continued extension of the SEDIBUD metadata database with these datasets, (iii) The testing of defined SEDIBUD hypotheses (available online, see below) by using datasets continuously compiled in the SEDIBUD metadata database, (iv) The publication of a SEDIBUD book (synthesis book). Detailed information on the SEDIBUD Programme, SEDIBUD meetings, SEDIBUD publications and SEDIBUD online documents and databases is available at the SEDIBUD website under http://www.geomorph.org/wg/wgsb.html.

Three keys to the radiation of angiosperms into freezing environments.

PubMed

Zanne, Amy E; Tank, David C; Cornwell, William K; Eastman, Jonathan M; Smith, Stephen A; FitzJohn, Richard G; McGlinn, Daniel J; O'Meara, Brian C; Moles, Angela T; Reich, Peter B; Royer, Dana L; Soltis, Douglas E; Stevens, Peter F; Westoby, Mark; Wright, Ian J; Aarssen, Lonnie; Bertin, Robert I; Calaminus, Andre; Govaerts, Rafaël; Hemmings, Frank; Leishman, Michelle R; Oleksyn, Jacek; Soltis, Pamela S; Swenson, Nathan G; Warman, Laura; Beaulieu, Jeremy M

2014-02-06

Early flowering plants are thought to have been woody species restricted to warm habitats. This lineage has since radiated into almost every climate, with manifold growth forms. As angiosperms spread and climate changed, they evolved mechanisms to cope with episodic freezing. To explore the evolution of traits underpinning the ability to persist in freezing conditions, we assembled a large species-level database of growth habit (woody or herbaceous; 49,064 species), as well as leaf phenology (evergreen or deciduous), diameter of hydraulic conduits (that is, xylem vessels and tracheids) and climate occupancies (exposure to freezing). To model the evolution of species' traits and climate occupancies, we combined these data with an unparalleled dated molecular phylogeny (32,223 species) for land plants. Here we show that woody clades successfully moved into freezing-prone environments by either possessing transport networks of small safe conduits and/or shutting down hydraulic function by dropping leaves during freezing. Herbaceous species largely avoided freezing periods by senescing cheaply constructed aboveground tissue. Growth habit has long been considered labile, but we find that growth habit was less labile than climate occupancy. Additionally, freezing environments were largely filled by lineages that had already become herbs or, when remaining woody, already had small conduits (that is, the trait evolved before the climate occupancy). By contrast, most deciduous woody lineages had an evolutionary shift to seasonally shedding their leaves only after exposure to freezing (that is, the climate occupancy evolved before the trait). For angiosperms to inhabit novel cold environments they had to gain new structural and functional trait solutions; our results suggest that many of these solutions were probably acquired before their foray into the cold.

The European Science Foundation (ESF) Network SEDIFLUX — An introduction and overview

NASA Astrophysics Data System (ADS)

Beylich, Achim A.; Etienne, Samuel; Etzelmüller, Bernd; Gordeev, Vyacheslav V.; Käyhkö, Jukka; Rachold, Volker; Russell, Andrew J.; Schmidt, Karl-Heinz; Sæmundsson, Þorsteinn; Tweed, Fiona S.; Warburton, Jeff

2006-10-01

Climate change will cause major changes in the Earth surface systems, especially in high-latitude and high-altitude cold environments. Geomorphological processes operating at the Earth's surface, transferring sediments and changing landforms are dependent on climate and will be significantly affected by climate change. More reliable modelling of sediment transfer processes operating under present-day climatic settings is needed to determine the consequences of climate change. It is necessary to collect and to compare data and knowledge from a wide range of different high-latitude and high-altitude cold environments and to develop more standardized methods and approaches for future research on sediment fluxes and relationships between climate and sedimentary transfer processes. In Europe, the wide range of high-latitude and high-altitude cold environments provides great potential to investigate climate-process relationships and to model the effects of climate change by using space for time substitution. The European Science Foundation (ESF) Network (01.01.2004-31.12.2006) "Sedimentary Source-to-Sink-Fluxes in Cold Environments" ( SEDIFLUX) is bringing together leading scientists, young scientists and research teams from different fields. SEDIFLUX forms a framework for an integrated and multidisciplinary investigation of the addressed topic and is a major catalyst for strengthening and extending contacts, collaborative research activities and mobility of scientists in Europe. It also points to areas within Europe that would benefit from wider research collaboration (e.g. Russia, Poland). The SEDIFLUX Steering Committee consists of scientists from seven European countries: Achim A. Beylich, Co-ordinator of SEDIFLUX (Trondheim, Norway), Samuel Etienne (Clermont-Ferrand, France), Bernd Etzelmüller (Oslo, Norway), Vyacheslav V. Gordeev (Moscow, Russia), Jukka Käyhkö (Turku, Finland), Volker Rachold (Potsdam, Germany), Andrew J. Russell (Newcastle, England, UK), Karl-Heinz Schmidt (Halle/S., Germany), Þorsteinn Sæmundsson (Sauðárkrókur, Iceland), Fiona S. Tweed (Staffordshire, England, UK) and Jeff Warburton (Durham, England, UK). SEDIFLUX activities include four Science Meetings: in Sauðárkrókur, Iceland (June 18th-June 21st, 2004), Clermont-Ferrand, France (January 20th-22nd, 2005), Durham, England, UK (December 15th-20th, 2005) and Trondheim, Norway (October 29th-November 1st, 2006), Steering Committee Meetings attached to these Science Meetings, a Session co-organized by SEDIFLUX at the Second European Permafrost Conference, June 12th-17th, 2005, in Potsdam, Germany, publication of Scientific Reports and Abstract Volumes, publication of Special Issues of Journals and of a SEDIFLUX Handbook, creation of a SEDIFLUX Database, an effective diffusion and dissemination of SEDIFLUX activities and outputs by using electronic media (Websites, Newsletters, Forum), invitations of leading experts from other parts of the world, policy makers and land managers to the Science Meetings. The ESF Network SEDIFLUX is organized in four Working Groups: I: Selection of critical test catchments; II: Analysis of geographical and geological settings of test catchments; III: Analysis of present-day fluxes; IV: Integration and data management. The major outputs from the Working Groups will be published in the SEDIFLUX Handbook, including guidelines for future monitoring programmes and a section, which is particularly targeted at end-users. A strong monitoring and operational data collection and more standardized methods provide a baseline for the development of reliable models and for future research in the changing high-latitude and high-altitude cold environments. ESF SEDIFLUX will continue and will be extended as I.A.G./A.I.G. Working Group on Sediment Budgets in Cold Environments (SEDIBUD). Apart from further collaborations and collaborative research activities project and programme applications at both the national and the European level following the three-year ESF Network are discussed and initiated.

Seed dormancy and germination changes of snowbed species under climate warming: the role of pre- and post-dispersal temperatures

PubMed Central

Bernareggi, Giulietta; Carbognani, Michele; Mondoni, Andrea; Petraglia, Alessandro

2016-01-01

Background and Aims Climate warming has major impacts on seed germination of several alpine species, hence on their regeneration capacity. Most studies have investigated the effects of warming after seed dispersal, and little is known about the effects a warmer parental environment may have on germination and dormancy of the seed progeny. Nevertheless, temperatures during seed development and maturation could alter the state of dormancy, affecting the timing of emergence and seedling survival. Here, the interplay between pre- and post-dispersal temperatures driving seed dormancy release and germination requirements of alpine plants were investigated. Methods Three plant species inhabiting alpine snowbeds were exposed to an artificial warming treatment (i.e. +1·5 K) and to natural conditions in the field. Seeds produced were exposed to six different periods of cold stratification (0, 2, 4, 8, 12 and 20 weeks at 0 °C), followed by four incubation temperatures (5, 10, 15 and 20 °C) for germination testing. Key Results A warmer parental environment produced either no or a significant increase in germination, depending on the duration of cold stratification, incubation temperatures and their interaction. In contrast, the speed of germination was less sensitive to changes in the parental environment. Moreover, the effects of warming appeared to be linked to the level of (physiological) seed dormancy, with deeper dormant species showing major changes in response to incubation temperatures and less dormant species in response to cold stratification periods. Conclusions Plants developed under warmer climates will produce seeds with changed germination responses to temperature and/or cold stratification, but the extent of these changes across species could be driven by seed dormancy traits. Transgenerational plastic adjustments of seed germination and dormancy shown here may result from increased seed viability, reduced primary and secondary dormancy state, or both, and may play a crucial role in future plant adaptation to climate change. PMID:27390354

Characterization of a rapid climate shift at the MIS 8/7 transition in central Spain (Valdocarros II, Autonomous Region of Madrid) by means of the herpetological assemblages

NASA Astrophysics Data System (ADS)

Blain, Hugues-Alexandre; Panera, Joaquin; Uribelarrea, David; Rubio-Jara, Susana; Pérez-González, Alfredo

2012-07-01

Climate instability with high-amplitude and rapid shifts during the Middle Pleistocene is well known from pollen records and deep-ocean sediment cores. Although poorly correlatable with such long climate/environment records, the successive fossil amphibian and reptile assemblages from the Middle Pleistocene site of Valdocarros II (Autonomous Region of Madrid, central Spain) provide a unique opportunity to characterize the climatic and environmental features of such rapid (certainly less than 1000 years) shifts from cold to warm conditions in a terrestrial sequence. As the amphibians and reptiles do not differ at species level from the extant herpetofauna of the Iberian Peninsula, they can contribute to the reconstruction of the landscape and climate. In this paper, the mutual climatic range and habitat weighting methods are applied to the herpetofaunistic assemblages in order to estimate quantitative data. The difference in mean annual temperature between "cold" and "warm" periods is estimated at 3.2 °C, with a greater increase in temperature during winter (+3 °C) than during summer (+1 °C). During "cold" periods the climate was more Oceanic (although preserving some dryness during the summers), whereas during "warm" periods the climate became Mediterranean (with mild winters and a long period of dryness in the summer and early autumn). Though higher during cold periods, the continentality (or atmospheric temperature range) remained roughly similar, in accordance with the geographical location of the site in the centre of the Iberian Peninsula. A greater amount of open landscape occurred during "cold" periods, whereas during "warm" periods the wooded areas expanded from 20% to 40% of the landscape surface. Such climatic/environmental changes, together with the numeric datings of the site, suggest that this shift may correspond to the transition from MIS 8 to MIS 7, also called Termination III.

Clay Mineralogy and Crystallinity as a Climatic Indicator: Evidence for Both Cold and Temperate Conditions on Early Mars

NASA Technical Reports Server (NTRS)

Horgan, B.; Rutledge, A.; Rampe, E. B.

2015-01-01

Surface weathering on Earth is driven by precipitation (rain/snow melt). Here we summarize the influence of climate on minerals produced during surface weathering, based on terrestrial literature and our new laboratory analyses of weathering products from glacial analog sites. By comparison to minerals identified in likely surface environments on Mars, we evaluate the implications for early martian climate.

Heating up relations between cold fish: competition modifies responses to climate change.

PubMed

Urban, Mark C; Holt, Robert D; Gilman, Sarah E; Tewksbury, Joshua

2011-05-01

Most predictions about species responses to climate change ignore species interactions. Helland and colleagues (2011) test whether this assumption is valid by evaluating whether ice cover affects competition between brown trout [Salmo trutta (L.)] and Arctic charr [Salvelinus alpines (L.)]. They show that increasing ice cover correlates with lower trout biomass when Arctic charr co-occur, but not in charr's absence. In experiments, charr grew better in the cold, dark environments that typify ice-covered lakes. Decreasing ice cover with warmer winters could mean more trout and fewer charr. More generally, their results provide an excellent example, suggesting that species interactions can strongly modify responses to climate change. © 2011 The Authors. Journal of Animal Ecology © 2011 British Ecological Society.

Global warming of salmon and trout rivers in the northwestern U.S.: Road to ruin or path through purgatory?

Treesearch

Daniel J. Isaak; Charles H. Luce; Dona L. Horan; Gwynne Chandler; Sherry Wollrab; David E. Nagel

2018-01-01

Large rivers constitute small portions of drainage networks but provide important migratory habitats and fisheries for salmon and trout when and where temperatures are sufficiently cold. Management and conservation of cold‐water fishes in the current era of rapid climate change requires knowing how riverine thermal environments are evolving and the potential for...

Paleosol stable isotope evidence for early hominid occupation of East Asian temperate environments

USGS Publications Warehouse

Wang, Hongfang; Ambrose, S.H.; Liu, Chen; Follmer, L.R.

1997-01-01

Hominids left Africa and occupied mainland Asia by 1.8 myr ago. About 1.15 myr ago Homo erectus and an associated Stegodon-Ailuropoda fauna migrated from subtropical China across the Qinling Mountains into the temperate Loess Plateau. This migration may be an evolutionary milestone in human adaptability because it may represent the first occupation of a nontropical environment. Loess-paleosol stable isotope ratios from the last interglacial-glacial cycle provide comparative data for reconstructing the hominid paleoenvironments. The climate during Gongwangling hominid occupation about 1.15 myr ago was influenced by both Siberian-Mongolian winter and Indian summer monsoon systems characterized as a cold/cool, dry winter and warm/mild, semihumid summer and fall. The Gongwangling hominids preyed mainly on warm-climate-adapted animals such as Stegodon-Ailuropoda fauna, suggesting a warm season occupation. The stable isotope ratios also indicate that the Chenjiawo hominids occupied an environment similar to that of the Gongwangling about 650,000 yr ago. The associated fauna, with a mixture of forest and steppe, warm-and cold/cool-climate-adapted animal assemblage's, suggests a permanent occupation by this time. Thus, the reliable earliest and permanent occupation of temperate environments may have occurred 150,000 yr earlier in eastern Asia rather than in Europe. ?? 1997 University of Washington.

Effects of cold treatments on fitness and mode of reproduction in the diploid and polyploid alpine plant Ranunculus kuepferi (Ranunculaceae).

PubMed

Klatt, Simone; Schinkel, Christoph C F; Kirchheimer, Bernhard; Dullinger, Stefan; Hörandl, Elvira

2018-06-08

Alpine plants grow in harsh environments and are thought to face occasional frost during the sensitive reproductive phase. Apomixis (asexual reproduction via seed) can be advantageous when sexual reproduction is disturbed by cold stress. Apomictic polyploids tend to grow in colder climates than their sexual diploid relatives. Whether cold temperatures actually induce apomixis was unknown to date. We tested experimentally in climate cabinets for effects of low temperatures and repeated frost on phenology, fitness and mode of reproduction in diploid and tetraploid cytotypes of the alpine species Ranunculus kuepferi. The reproduction mode was determined via flow cytometric seed screening (FCSS). Diploids produced the first flowers earlier than the tetraploids in all treatments. Cold treatments significantly reduced the fitness of both cytotypes regarding seed set, and increased the frequency of apomictic seed formation in diploids, but not in tetraploids. Over consecutive years, the degree of facultative apomixis showed individual phenotypic plasticity. Cold stress is correlated to expression of apomixis in warm-adapted, diploid R. kuepferi, while temperature-tolerant tetraploids just maintain facultative apomixis as a possible adaptation to colder climates. However, expression of apomixis may not depend on polyploidy, but rather on failure of the sexual pathway.

Performance, Physiological, and Acceptance Tests of a 1500 KCAL emergency/Assault Food Packet Diet in a Cold Weather Environment

DTIC Science & Technology

1980-11-01

acket (E/AP) and to assess performance and physiological effects of t he ration at two different ca loric levels. During a f ive-day exercise in a...PACKET FIELD FEEDING RAT IONS DIET(S) PHYSIOLOG ICAL EMERGENCY RATIONS COMPRESSED FOODS TESTS FREEZE DRIED FOODS COLD WEATH ER PERFORMANCE...cold-weather climate, one group of Marines was issued the standard C ration (3550 kca l) while half of a second group were issued one E/AP per day

Surface clay formation during short-term warmer and wetter conditions on a largely cold ancient Mars

NASA Astrophysics Data System (ADS)

Bishop, Janice L.; Fairén, Alberto G.; Michalski, Joseph R.; Gago-Duport, Luis; Baker, Leslie L.; Velbel, Michael A.; Gross, Christoph; Rampe, Elizabeth B.

2018-03-01

The ancient rock record for Mars has long been at odds with climate modelling. The presence of valley networks, dendritic channels and deltas on ancient terrains points towards running water and fluvial erosion on early Mars1, but climate modelling indicates that long-term warm conditions were not sustainable2. Widespread phyllosilicates and other aqueous minerals on the Martian surface3-6 provide additional evidence that an early wet Martian climate resulted in surface weathering. Some of these phyllosilicates formed in subsurface crustal environments5, with no association with the Martian climate, while other phyllosilicate-rich outcrops exhibit layered morphologies and broad stratigraphies7 consistent with surface formation. Here, we develop a new geochemical model for early Mars to explain the formation of these clay-bearing rocks in warm and wet surface locations. We propose that sporadic, short-term warm and wet environments during a generally cold early Mars enabled phyllosilicate formation without requiring long-term warm and wet conditions. We conclude that Mg-rich clay-bearing rocks with lateral variations in mixed Fe/Mg smectite, chlorite, talc, serpentine and zeolite occurrences formed in subsurface hydrothermal environments, whereas dioctahedral (Al/Fe3+-rich) smectite and widespread vertical horizonation of Fe/Mg smectites, clay assemblages and sulphates formed in variable aqueous environments on the surface of Mars. Our model for aluminosilicate formation on Mars is consistent with the observed geological features, diversity of aqueous mineralogies in ancient surface rocks and state-of-the-art palaeoclimate scenarios.

The potential for behavioral thermoregulation to buffer "cold-blooded" animals against climate warming.

PubMed

Kearney, Michael; Shine, Richard; Porter, Warren P

2009-03-10

Increasing concern about the impacts of global warming on biodiversity has stimulated extensive discussion, but methods to translate broad-scale shifts in climate into direct impacts on living animals remain simplistic. A key missing element from models of climatic change impacts on animals is the buffering influence of behavioral thermoregulation. Here, we show how behavioral and mass/energy balance models can be combined with spatial data on climate, topography, and vegetation to predict impacts of increased air temperature on thermoregulating ectotherms such as reptiles and insects (a large portion of global biodiversity). We show that for most "cold-blooded" terrestrial animals, the primary thermal challenge is not to attain high body temperatures (although this is important in temperate environments) but to stay cool (particularly in tropical and desert areas, where ectotherm biodiversity is greatest). The impact of climate warming on thermoregulating ectotherms will depend critically on how changes in vegetation cover alter the availability of shade as well as the animals' capacities to alter their seasonal timing of activity and reproduction. Warmer environments also may increase maintenance energy costs while simultaneously constraining activity time, putting pressure on mass and energy budgets. Energy- and mass-balance models provide a general method to integrate the complexity of these direct interactions between organisms and climate into spatial predictions of the impact of climate change on biodiversity. This methodology allows quantitative organism- and habitat-specific assessments of climate change impacts.

The potential for behavioral thermoregulation to buffer “cold-blooded” animals against climate warming

PubMed Central

Kearney, Michael; Shine, Richard; Porter, Warren P.

2009-01-01

Increasing concern about the impacts of global warming on biodiversity has stimulated extensive discussion, but methods to translate broad-scale shifts in climate into direct impacts on living animals remain simplistic. A key missing element from models of climatic change impacts on animals is the buffering influence of behavioral thermoregulation. Here, we show how behavioral and mass/energy balance models can be combined with spatial data on climate, topography, and vegetation to predict impacts of increased air temperature on thermoregulating ectotherms such as reptiles and insects (a large portion of global biodiversity). We show that for most “cold-blooded” terrestrial animals, the primary thermal challenge is not to attain high body temperatures (although this is important in temperate environments) but to stay cool (particularly in tropical and desert areas, where ectotherm biodiversity is greatest). The impact of climate warming on thermoregulating ectotherms will depend critically on how changes in vegetation cover alter the availability of shade as well as the animals' capacities to alter their seasonal timing of activity and reproduction. Warmer environments also may increase maintenance energy costs while simultaneously constraining activity time, putting pressure on mass and energy budgets. Energy- and mass-balance models provide a general method to integrate the complexity of these direct interactions between organisms and climate into spatial predictions of the impact of climate change on biodiversity. This methodology allows quantitative organism- and habitat-specific assessments of climate change impacts. PMID:19234117

Characteristics of organic soil in black spruce forests: implications for the application of land surface and ecosystem models in cold regions

Treesearch

Shuhua Yi; Kristen Manies; Jennifer Harden; David McGuire

2009-01-01

Soil organic layers (OL) play an important role in land-atmosphere exchanges of water, energy and carbon in cold environments. The proper implementation of OL in land surface and ecosystem models is important for predicting dynamic responses to climate warming. Based on the analysis of OL samples of black spruce (Picea mariana), we recommend that...

Climate and foraging mode explain interspecific variation in snake metabolic rates.

PubMed

Dupoué, Andréaz; Brischoux, François; Lourdais, Olivier

2017-11-29

The energy cost of self-maintenance is a critical facet of life-history strategies. Clarifying the determinant of interspecific variation in metabolic rate (MR) at rest is important to understand and predict ecological patterns such as species distributions or responses to climatic changes. We examined variation of MR in snakes, a group characterized by a remarkable diversity of activity rates and a wide distribution. We collated previously published MR data ( n = 491 observations) measured in 90 snake species at different trial temperatures. We tested for the effects of metabolic state (standard MR (SMR) versus resting MR (RMR)), foraging mode (active versus ambush foragers) and climate (temperature and precipitation) while accounting for non-independence owing to phylogeny, body mass and thermal dependence. We found that RMR was 40% higher than SMR, and that active foragers have higher MR than species that ambush their prey. We found that MR was higher in cold environments, supporting the metabolic cold adaptation hypothesis. We also found an additive and positive effect of precipitation on MR suggesting that lower MR in arid environments may decrease dehydration and energetic costs. Altogether, our findings underline the complex influences of climate and foraging mode on MR and emphasize the relevance of these facets to understand the physiological impact of climate change. © 2017 The Author(s).

Biophysical evaluation of footwear for cold-weather climates.

PubMed

Santee, W R; Endrusick, T L

1988-02-01

Proper selection of footwear for cold-wet environments is important in determining individual performance and comfort. Testing only total dry insulation (It) is not a wholly adequate basis for boot selection. The present study demonstrates an effective method for evaluating the effects of surface moisture on boot insulation. This method allows a more knowledgeable selection of footwear for cold-wet climates. In this study, regional insulation values were obtained under dry conditions, then during a soak in shallow water, and finally for insulation recovery after removal from water. Results for seven boots show no advantage of presently used synthetic materials during short soak episodes. Insulated leather-synthetic boots, however, recovered to dry insulation levels more rapidly than more traditional insulated leather boots. Rubber waterproof bottoms were the most effective boot construction for retaining insulation levels during water exposure.

Comparing Enchytraeus albidus populations from contrasting climatic environments suggest a link between cold tolerance and metabolic activity.

PubMed

Žagar, Anamarija; Holmstrup, Martin; Simčič, Tatjana; Debeljak, Barabara; Slotsbo, Stine

2018-06-06

Basal metabolic activity and freezing of body fluids create reactive oxygen species (ROS) in freeze-tolerant organisms. These sources of ROS can have an additive negative effect via oxidative stress. In cells, antioxidant systems are responsible for removing ROS in order to avoid damage due to oxidative stress. Relatively little is known about the importance of metabolic rate for the survival of freezing, despite a good understanding of several cold tolerance related physiological mechanisms. We hypothesized that low basal metabolism would be selected for in freeze-tolerant organisms where winter survival is important for fitness for two reasons. First, avoidance of the additive effect of ROS production from metabolism and freezing, and second, as an energy-saving mechanism under extended periods of freezing where the animal is metabolically active, but unable to feed. We used the terrestrial oligochaete, Enchytraeus albidus, which is widely distributed from Spain to the high Arctic and compared eight populations originating across a broad geographical and climatic gradient after they had been cold acclimated at 5 °C in a common garden experiment. Cold tolerance (lower lethal temperature: LT50) and the potential metabolic activity (PMA, an estimator of the maximal enzymatic potential of the mitochondrial respiration chain) of eight populations were positively correlated amongst each other and correlated negatively with latitude and positively with average yearly temperature and the average temperature of the coldest month. These results indicate that low PMA in cold tolerant populations is important for survival in extremely cold environments. Copyright © 2018 Elsevier Inc. All rights reserved.

Flood Seasonality in a Changing Climate - A Comparison Between Northern Europe and Northeastern North America

NASA Astrophysics Data System (ADS)

Matti, B.; Dahlke, H. E.; Dieppois, B.; Lawler, D.; Lyon, S. W.

2016-12-01

Fluvial flood events have a large impact on humans, both socially and economically. Concurrent with climate change flood seasonality in cold environments is expected to shift from a snowmelt-dominated to a rainfall-dominated flow regime. This would have profound impacts on water management strategies, i.e. flood risk mitigation, drinking water supply and hydro power. In addition, cold climate hydrological systems exhibit complex interactions with catchment properties and large-scale climate fluctuations making the manifestation of changes difficult to detect and predict. Understanding a possible change in flood seasonality is essential to mitigate risk and to keep management strategies viable under a changing climate. This study explored changes in flood seasonality across near-natural catchments in cold environments of the North Atlantic region (40 - 70° N) using circular statistics and trend tests. Results indicate strong seasonality in flooding for snowmelt-dominated catchments with a single peak occurring in spring (March through May), whereas flood peaks are more equally distributed throughout the year for catchments located close to the Atlantic coast and in the south of the study area. Flood seasonality has changed over the past century seen as decreasing trends in summer maximum daily flows and increasing winter and spring maximum daily flows. Mean daily flows corroborate those findings with approximately 50% of the catchments showing significant changes. Comparing Scandinavia to North America the same trends could be detected with a stronger signal at the west coast of Scandinavia due to the Westerlies. Contrasting trends were detected for spring flows, for which North American catchments showed decreasing trends whereas increasing trends were observed across Scandinavia. Such changes in flood seasonality have clear implications for management strategies such as the estimation of design floods for flood prevention measures.

Repeated short climatic change affects the epidermal differentiation program and leads to matrix remodeling in a human organotypic skin model.

PubMed

Boutrand, Laetitia-Barbollat; Thépot, Amélie; Muther, Charlotte; Boher, Aurélie; Robic, Julie; Guéré, Christelle; Vié, Katell; Damour, Odile; Lamartine, Jérôme

2017-01-01

Human skin is subject to frequent changes in ambient temperature and humidity and needs to cope with these environmental modifications. To decipher the molecular response of human skin to repeated climatic change, a versatile model of skin equivalent subject to "hot-wet" (40°C, 80% relative humidity [RH]) or "cold-dry" (10°C, 40% RH) climatic stress repeated daily was used. To obtain an exhaustive view of the molecular mechanisms elicited by climatic change, large-scale gene expression DNA microarray analysis was performed and modulated function was determined by bioinformatic annotation. This analysis revealed several functions, including epidermal differentiation and extracellular matrix, impacted by repeated variations in climatic conditions. Some of these molecular changes were confirmed by histological examination and protein expression. Both treatments (hot-wet and cold-dry) reduced the expression of genes encoding collagens, laminin, and proteoglycans, suggesting a profound remodeling of the extracellular matrix. Strong induction of the entire family of late cornified envelope genes after cold-dry exposure, confirmed at protein level, was also observed. These changes correlated with an increase in epidermal differentiation markers such as corneodesmosin and a thickening of the stratum corneum, indicating possible implementation of defense mechanisms against dehydration. This study for the first time reveals the complex pattern of molecular response allowing adaption of human skin to repeated change in its climatic environment.

Seed dormancy and germination changes of snowbed species under climate warming: the role of pre- and post-dispersal temperatures.

PubMed

Bernareggi, Giulietta; Carbognani, Michele; Mondoni, Andrea; Petraglia, Alessandro

2016-09-01

Climate warming has major impacts on seed germination of several alpine species, hence on their regeneration capacity. Most studies have investigated the effects of warming after seed dispersal, and little is known about the effects a warmer parental environment may have on germination and dormancy of the seed progeny. Nevertheless, temperatures during seed development and maturation could alter the state of dormancy, affecting the timing of emergence and seedling survival. Here, the interplay between pre- and post-dispersal temperatures driving seed dormancy release and germination requirements of alpine plants were investigated. Three plant species inhabiting alpine snowbeds were exposed to an artificial warming treatment (i.e. +1·5 K) and to natural conditions in the field. Seeds produced were exposed to six different periods of cold stratification (0, 2, 4, 8, 12 and 20 weeks at 0 °C), followed by four incubation temperatures (5, 10, 15 and 20 °C) for germination testing. A warmer parental environment produced either no or a significant increase in germination, depending on the duration of cold stratification, incubation temperatures and their interaction. In contrast, the speed of germination was less sensitive to changes in the parental environment. Moreover, the effects of warming appeared to be linked to the level of (physiological) seed dormancy, with deeper dormant species showing major changes in response to incubation temperatures and less dormant species in response to cold stratification periods. Plants developed under warmer climates will produce seeds with changed germination responses to temperature and/or cold stratification, but the extent of these changes across species could be driven by seed dormancy traits. Transgenerational plastic adjustments of seed germination and dormancy shown here may result from increased seed viability, reduced primary and secondary dormancy state, or both, and may play a crucial role in future plant adaptation to climate change. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Noachian Climate of Mars: Insights from Noachian Stratigraphy and Valley Networks System Formation Times

NASA Astrophysics Data System (ADS)

Head, J. W., III

2017-12-01

Noachian climate models have been proposed in order to account for 1) observed fluvial and lacustrine activity, 2) weathering processes producing phyllosilicates, and 3) an unusual impact record including three major impact basins and unusual degradation processes. We adopt a stratigraphic approach in order place these observations in a temporal context. Formation of the major impact basins Hellas, Isidis and Argyre in earlier Noachian profoundly influenced the uplands geology and appears to have occurred concurrently with major phyllosilicate and related surface occurrences/deposits; the immediate aftermath of these basins appears to have created a temporary hot and wet surface environment with significant effect on surface morphology and alteration processes. Formation of Late Noachian-Early Hesperian valley network systems (VNS) signaled the presence of warm/wet conditions generating several hypotheses for climates permissive of these conditions. We examined estimates for the time required to carve channels/deltas and total duration implied by plausible intermittencies. Synthesis of required timescales show that the total time to carve the VN does not exceed 106 years, < 0.25% of the total Noachian. What climate models can account for the VNS? 1) Warm and wet/semiarid/arid climate: Sustained background MAT >273 K, hydrological system vertically integrated, and rainfall occurs to recharge the aquifer. 2) Cold and Icy climate warmed by greenhouse gases or episodic stochastic events: Climate is sustained cold/icy, but greenhouse gases of unspecified nature/amount/duration elevate MAT by several tens of Kelvins, bringing the annual temperature range into the realm where peak seasonal temperatures (PST) exceed 273 K. In this climate environment, analogous to the Antarctic Dry Valleys, seasonal summer temperatures above 273 K are sufficient to melt snow/ice and form fluvial and lacustrine features, but MAT is well below 273 K (253 K); punctuated warming alternatives include impacts or volcanic eruptions. We conclude that a cold and icy background climate with modest greenhouse warming or punctuated warming and melting events for the VNs origin is consistent with: 1) the estimated durations of continuous VN formation (<105 years) and 2) VN system estimated recurrence rates (106-107 years).

The SEDIBUD (Sediment Budgets in Cold Environments) Programme: Current activities and future key tasks

NASA Astrophysics Data System (ADS)

Beylich, A. A.; Lamoureux, S. F.; Decaulne, A.

2012-04-01

Projected climate change in cold regions is expected to alter melt season duration and intensity, along with the number of extreme rainfall events, total annual precipitation and the balance between snowfall and rainfall. Similarly, changes to the thermal balance are expected to reduce the extent of permafrost and seasonal ground frost and increase active layer depths. These effects will undoubtedly change surface environments in cold regions and alter the fluxes of sediments, nutrients and solutes, but the absence of quantitative data and coordinated process monitoring and analysis to understand the sensitivity of the Earth surface environment is acute in cold climate environments. The International Association of Geomorphologists (I.A.G./A.I.G.)SEDIBUD (Sediment Budgets in Cold Environments) Programme was formed in 2005 to address this existing key knowledge gap. SEDIBUD currently has about 400 members worldwide and the Steering Committee of this international programme is composed of ten scientists from eight different countries: Achim A. Beylich (Chair) (Norway), Armelle Decaulne (Secretary) (France), John C. Dixon (USA), Scott F. Lamoureux (Vice-Chair) (Canada), John F. Orwin (Canada), Jan-Christoph Otto (Austria), Irina Overeem (USA), Thorsteinn Saemundsson (Iceland), Jeff Warburton (UK), Zbigniew Zwolinski (Poland). The central research question of this global group of scientists is to: Assess and model the contemporary sedimentary fluxes in cold climates, with emphasis on both particulate and dissolved components. Initially formed as European Science Foundation (ESF) Network SEDIFLUX (2004-2006), SEDIBUD has further expanded to a global group of researchers with field research sites located in polar and alpine regions in the northern and southern hemisphere. Research carried out at each of the close to 50 defined SEDIBUD key test sites varies by programme, logistics and available resources, but typically represent interdisciplinary collaborations of geomorphologists, hydrologists, ecologists, permafrost scientists and glaciologists. SEDIBUD has developed manuals and protocols (SEDIFLUX Manual, available online, see below) with a key set of primary surface process monitoring and research data requirements to incorporate results from these diverse projects and allow coordinated quantitative analysis across the programme. Defined SEDIBUD key test sites provide data on annual climate conditions, total discharge and particulate and dissolved fluxes as well as information on other relevant surface processes. A number of selected key test sites is providing high-resolution data on climate conditions, runoff and sedimentary fluxes, which in addition to the annual data contribute to the SEDIBUD metadata database which is currently developed. Comparable datasets from different SEDIBUD key test sites are integrated and analysed to address key research questions as defined in the SEDIBUD Objective (available online, see below). Defined SEDIBUD key tasks for the coming years include (i) The continued generation and compilation of comparable longer-term datasets on contemporary sedimentary fluxes and sediment yields from SEDIBUD key test sites worldwide, (ii) The continued extension of the SEDIBUD metadata database with these datasets, (iii) The testing of defined SEDIBUD hypotheses (available online, see below) by using the datasets continuously compiled in the SEDIBUD metadata database. Detailed information on the I.A.G./A.I.G. SEDIBUD Programme, SEDIBUD meetings, SEDIBUD publications and SEDIBUD online documents and databases is available at the SEDIBUD website under http://www.geomorph.org/wg/wgsb.html.

Climate Change and International Competition: the US Army in the Arctic Environment

DTIC Science & Technology

2015-05-21

capabilities are evaluated within the domains of the current US doctrinal definition of Doctrine , Organization, Training, Materiel, Leadership and Education...environment. 15. SUBJECT TERMS US Army Cold Weather Doctrine ; US Army Arctic Operational Capability; ULO; Mission Command; Arctic Council; UNCLOS...capabilities are evaluated within the domains of the current US doctrinal definition of Doctrine , Organization, Training, Materiel, Leadership and

Bioremediation of petroleum spills in Arctic and Sub-Arctic environments

DOT National Transportation Integrated Search

1989-11-01

Unaided rehabilitation of petroleum spills can affect tundra soils for up to 30 years. Effects of oil spills on Sub-Arctic forest soils last for at least a decade. Natural remediation is slow because of the cold dominated climate and short growing se...

Cold periods and coronary events: an analysis of populations worldwide

PubMed Central

Barnett, A.; Dobson, A.; McElduff, P.; Salomaa, V.; Kuulasmaa, K.; Sans, S.; t for

2005-01-01

Study objective: To investigate the association between cold periods and coronary events, and the extent to which climate, sex, age, and previous cardiac history increase risk during cold weather. Design: A hierarchical analyses of populations from the World Health Organisation's MONICA project. Setting: Twenty four populations from the WHO's MONICA project, a 21 country register made between 1980 and 1995. Patients: People aged 35–64 years who had a coronary event. Main results: Daily rates of coronary events were correlated with the average temperature over the current and previous three days. In cold periods, coronary event rates increased more in populations living in warm climates than in populations living in cold climates, where the increases were slight. The increase was greater in women than in men, especially in warm climates. On average, the odds for women having an event in the cold periods were 1.07 higher than the odds for men (95% posterior interval: 1.03 to 1.11). The effects of cold periods were similar in those with and without a history of a previous myocardial infarction. Conclusions: Rates of coronary events increased during comparatively cold periods, especially in warm climates. The smaller increases in colder climates suggest that some events in warmer climates are preventable. It is suggested that people living in warm climates, particularly women, should keep warm on cold days. PMID:15965137

Impact of climate change on cold hardiness of Douglas-fir (Pseudotsuga menziesii): Environmental and genetic considerations

Treesearch

Sheel Bansal; Bradley J. St. Clair; Constance A. Harrington; Peter J. Gould

2015-01-01

The success of conifers over much of the world’s terrestrial surface is largely attributable to their tolerance to cold stress (i.e., cold hardiness). Due to an increase in climate variability, climate change may reduce conifer cold hardiness, which in turn could impact ecosystem functioning and productivity in conifer-dominated forests. The expression of cold...

The influence of a heat and moisture exchanger on tracheal climate in a cold environment.

PubMed

Zuur, J Karel; Muller, Sara H; Vincent, Andrew; Sinaasappel, Michiel; de Jongh, Frans H C; Hilgers, Frans J M

2009-09-01

The incidence of pulmonary complaints, severe tracheitis and lung function deterioration is increased during wintertime in laryngectomized individuals. We analyzed how a heat and moisture exchanger (HME) performs in cold and dry ambient circumstances, and how its efficiency in this environmental climate might be improved. Randomized crossover. Intra-tracheal temperature and humidity were measured in 10 laryngectomized patients with and without HME, in a cold (mean, 4.7 degrees C) and dry (mean, 4.5 mgH2O/L) room. Presence of an HME causes the intra-tracheal mean humidity minima and maxima to increase with 4.2 mgH2O/L (95%CI: 3.3-5.0 mgH2O/L; p<0.001) and 2.4 mgH2O/L (95%CI: 1.7-3.1 mgH2O/L; p<0.001), respectively. The intra-tracheal mean temperature minima and maxima increased with 3.9 degrees C (95%CI: 2.7-5.1 degrees C; p<0.001) and 1.2 degrees C (95%CI: 0.8-1.2 degrees C; p<0.001), respectively. In the majority of patients, the calculated relative humidity values appear to reach well above 100% during inspiration. In a cold environment, presence of an HME significantly increases both inspiratory and expiratory temperature and humidity values. Relative humidity calculations suggest the formation of condense droplets during inspiration. To further increase its effectiveness, improvement of the HME's thermal capacity should be aimed for.

Molluscan evidence for early middle Miocene marine glaciation in southern Alaska

USGS Publications Warehouse

Marincovich, L.

1990-01-01

Profound cooling of Miocene marine climates in southern Alaska culminated in early middle Miocene coastal marine glaciation in the northeastern Gulf of Alaska. This climatic change resulted from interaction of the Yakutat terrane with southern Alaska beginning in late Oligocene time. The ensuing extreme uplift of the coastal Chugach and St. Elias Mountains resulted in progressive regional cooling that culminated in coastal marine glaciation beginning in the early middle Miocene (15-16 Ma) and continuing to the present. The counterclockwise flow of surface water from the frigid northeastern Gulf of Alaska resulted in a cold-temperate shallow-marine environment in the western Gulf of Alaska, as it does today. Ironically, dating of Gulf of Alaska marine glaciation as early middle Miocene is strongly reinforced by the presence of a few tropical and subtropical mollusks in western Gulf of Alaska faunas. Shallow-marine waters throughout the Gulf of Alaska were cold-temperate to cold in the early middle Miocene, when the world ocean was undergoing peak Neogene warming. -Author

Body temperature modulates the antioxidant and acute immune responses to exercise.

PubMed

Mestre-Alfaro, Antonia; Ferrer, Miguel D; Banquells, Montserrat; Riera, Joan; Drobnic, Franchek; Sureda, Antoni; Tur, Josep A; Pons, Antoni

2012-06-01

The aim of this study was to determine the effects of whole body heat in combination with exercise on the oxidative stress and acute phase immune response. Nine male endurance-trained athletes voluntarily performed two running bouts of 45 minutes at 75-80% of VO(2max) in a climatic chamber in two conditions: cold and hot humid environment. Leukocyte, neutrophil and basophil counts significantly rose after exercise in both environments; it was significantly greater in the hot environment. Lymphocyte and neutrophil antioxidant enzyme activities and carbonyl index significantly increased or decreased after exercise only in the hot environment, respectively. The lymphocytes expression of catalase, Hsp72 and CuZn-superoxide dismutase was increased in the hot environment and Sirt3 in the cold environment, mainly during recovery. In conclusion, the increased core body temperature results in the acute phase immune response associated to intense exercise and in the immune cell adaptations to counteract the oxidative stress situation.

Comparison of UTCI with Other Thermal Indices in the Assessment of Heat and Cold Effects on Cardiovascular Mortality in the Czech Republic

PubMed Central

Urban, Aleš; Kyselý, Jan

2014-01-01

We compare the recently developed Universal Thermal Climate Index (UTCI) with other thermal indices in analysing heat- and cold-related effects on cardiovascular (CVD) mortality in two different (urban and rural) regions in the Czech Republic during the 16-year period from 1994–2009. Excess mortality is represented by the number of deaths above expected daily values, the latter being adjusted for long-term changes, annual and weekly cycles, and epidemics of influenza/acute respiratory infections. Air temperature, UTCI, Apparent Temperature (AT) and Physiologically Equivalent Temperature (PET) are applied to identify days with heat and cold stress. We found similar heat effects on CVD mortality for air temperature and the examined thermal indices. Responses of CVD mortality to cold effects as characterised by different indices were much more varied. Particularly important is the finding that air temperature provides a weak cold effect in comparison with the thermal indices in both regions, so its application—still widespread in epidemiological studies—may underestimate the magnitude of cold-related mortality. These findings are important when possible climate change effects on heat- and cold-related mortality are estimated. AT and PET appear to be more universal predictors of heat- and cold- related mortality than UTCI when both urban and rural environments are of concern. UTCI tends to select windy rather than freezing days in winter, though these show little effect on mortality in the urban population. By contrast, significant cold-related mortality in the rural region if UTCI is used shows potential for UTCI to become a useful tool in cold exposure assessments. PMID:24413706

The Crippler: Frostbite.

ERIC Educational Resources Information Center

Keller, Rosanne

Part of a series of home literacy readers, written in a conversational style, and widely illustrated, this booklet is directed at the Alaskan environment where the severely cold climate makes frostbite an immediate danger. Frostbite is freezing of the living body. The first symptom is frostnip. Skin becomes red, then white or gray, and it retains…

Cold-climate slope deposits and landscape modifications of the Mid-Atlantic Coastal Plain, Eastern USA

USGS Publications Warehouse

Newell, Wayne L.; Dejong, B.D.

2011-01-01

The effects of Pleistocene cold-climate geomorphology are distributed across the weathered and eroded Mid-Atlantic Coastal Plain uplands from the Wisconsinan terminal moraine south to Tidewater Virginia. Cold-climate deposits and landscape modifications are superimposed on antecedent landscapes of old, weathered Neogene upland gravels and Pleistocene marine terraces that had been built during warm periods and sea-level highstands. In New Jersey, sequences of surficial deposits define a long history of repeating climate change events. To the south across the Delmarva Peninsula and southern Maryland, most antecedent topography has been obscured by Late Pleistocene surficial deposits. These are spatially variable and are collectively described as a cold-climate alloformation. The cold-climate alloformation includes time-transgressive details of climate deterioration from at least marine isotope stage (MIS) 4 through the end of MIS 2. Some deposits and landforms within the alloformation may be as young as the Younger Dryas. Southwards along the trend of the Potomac River, these deposits and their climatic affinities become diffused. In Virginia, a continuum of erosion and surficial deposits appears to be the product of ‘normal’ temperate, climate-forced processes. The cold-climate alloformation and more temperate deposits in Virginia are being partly covered by Holocene alluvium and bay mud.

Permafrost Meta-Omics and Climate Change

NASA Astrophysics Data System (ADS)

Mackelprang, Rachel; Saleska, Scott R.; Jacobsen, Carsten Suhr; Jansson, Janet K.; Taş, Neslihan

2016-06-01

Permanently frozen soil, or permafrost, covers a large portion of the Earth's terrestrial surface and represents a unique environment for cold-adapted microorganisms. As permafrost thaws, previously protected organic matter becomes available for microbial degradation. Microbes that decompose soil carbon produce carbon dioxide and other greenhouse gases, contributing substantially to climate change. Next-generation sequencing and other -omics technologies offer opportunities to discover the mechanisms by which microbial communities regulate the loss of carbon and the emission of greenhouse gases from thawing permafrost regions. Analysis of nucleic acids and proteins taken directly from permafrost-associated soils has provided new insights into microbial communities and their functions in Arctic environments that are increasingly impacted by climate change. In this article we review current information from various molecular -omics studies on permafrost microbial ecology and explore the relevance of these insights to our current understanding of the dynamics of permafrost loss due to climate change.

Thermal affinity as the dominant factor changing Mediterranean fish abundances.

PubMed

Givan, Or; Edelist, Dor; Sonin, Oren; Belmaker, Jonathan

2018-01-01

Recent decades have seen profound changes in species abundance and community composition. In the marine environment, the major anthropogenic drivers of change comprise exploitation, invasion by nonindigenous species, and climate change. However, the magnitude of these stressors has been widely debated and we lack empirical estimates of their relative importance. In this study, we focused on Eastern Mediterranean, a region exposed to an invasion of species of Red Sea origin, extreme climate change, and high fishing pressure. We estimated changes in fish abundance using two fish trawl surveys spanning a 20-year period, and correlated these changes with estimated sensitivity of species to the different stressors. We estimated sensitivity to invasion using the trait similarity between indigenous and nonindigenous species; sensitivity to fishing using a published composite index based on the species' life-history; and sensitivity to climate change using species climatic affinity based on occurrence data. Using both a meta-analytical method and random forest analysis, we found that for shallow-water species the most important driver of population size changes is sensitivity to climate change. Species with an affinity to warm climates increased in relative abundance and species with an affinity to cold climates decreased suggesting a strong response to warming local sea temperatures over recent decades. This decrease in the abundance of cold-water-associated species at the trailing "warm" end of their distribution has been rarely documented. Despite the immense biomass of nonindigenous species and the presumed high fishing pressure, these two latter factors seem to have only a minor role in explaining abundance changes. The decline in abundance of indigenous species of cold-water origin indicates a future major restructuring of fish communities in the Mediterranean in response to the ongoing warming, with unknown impacts on ecosystem function. © 2017 John Wiley & Sons Ltd.

Non-stationary Return Levels of CMIP5 Multi-model Temperature Extremes

DOE PAGES

Cheng, L.; Phillips, T. J.; AghaKouchak, A.

2015-05-01

The objective of this study is to evaluate to what extent the CMIP5 climate model simulations of the climate of the twentieth century can represent observed warm monthly temperature extremes under a changing environment. The biases and spatial patterns of 2-, 10-, 25-, 50- and 100-year return levels of the annual maxima of monthly mean temperature (hereafter, annual temperature maxima) from CMIP5 simulations are compared with those of Climatic Research Unit (CRU) observational data considered under a non-stationary assumption. The results show that CMIP5 climate models collectively underestimate the mean annual maxima over arid and semi-arid regions that are mostmore » subject to severe heat waves and droughts. Furthermore, the results indicate that most climate models tend to underestimate the historical annual temperature maxima over the United States and Greenland, while generally disagreeing in their simulations over cold regions. Return level analysis shows that with respect to the spatial patterns of the annual temperature maxima, there are good agreements between the CRU observations and most CMIP5 simulations. However, the magnitudes of the simulated annual temperature maxima differ substantially across individual models. Discrepancies are generally larger over higher latitudes and cold regions.« less

Potential Effects of Climate Change on the Distribution of Cold-Tolerant Evergreen Broadleaved Woody Plants in the Korean Peninsula.

PubMed

Koo, Kyung Ah; Kong, Woo-Seok; Nibbelink, Nathan P; Hopkinson, Charles S; Lee, Joon Ho

2015-01-01

Climate change has caused shifts in species' ranges and extinctions of high-latitude and altitude species. Most cold-tolerant evergreen broadleaved woody plants (shortened to cold-evergreens below) are rare species occurring in a few sites in the alpine and subalpine zones in the Korean Peninsula. The aim of this research is to 1) identify climate factors controlling the range of cold-evergreens in the Korean Peninsula; and 2) predict the climate change effects on the range of cold-evergreens. We used multimodel inference based on combinations of climate variables to develop distribution models of cold-evergreens at a physiognomic-level. Presence/absence data of 12 species at 204 sites and 6 climatic factors, selected from among 23 candidate variables, were used for modeling. Model uncertainty was estimated by mapping a total variance calculated by adding the weighted average of within-model variation to the between-model variation. The range of cold-evergreens and model performance were validated by true skill statistics, the receiver operating characteristic curve and the kappa statistic. Climate change effects on the cold-evergreens were predicted according to the RCP 4.5 and RCP 8.5 scenarios. Multimodel inference approach excellently projected the spatial distribution of cold-evergreens (AUC = 0.95, kappa = 0.62 and TSS = 0.77). Temperature was a dominant factor in model-average estimates, while precipitation was minor. The climatic suitability increased from the southwest, lowland areas, to the northeast, high mountains. The range of cold-evergreens declined under climate change. Mountain-tops in the south and most of the area in the north remained suitable in 2050 and 2070 under the RCP 4.5 projection and 2050 under the RCP 8.5 projection. Only high-elevations in the northeastern Peninsula remained suitable under the RCP 8.5 projection. A northward and upper-elevational range shift indicates change in species composition at the alpine and subalpine ecosystems in the Korean Peninsula.

Potential Effects of Climate Change on the Distribution of Cold-Tolerant Evergreen Broadleaved Woody Plants in the Korean Peninsula

PubMed Central

Koo, Kyung Ah; Kong, Woo-Seok; Nibbelink, Nathan P.; Hopkinson, Charles S.; Lee, Joon Ho

2015-01-01

Climate change has caused shifts in species’ ranges and extinctions of high-latitude and altitude species. Most cold-tolerant evergreen broadleaved woody plants (shortened to cold-evergreens below) are rare species occurring in a few sites in the alpine and subalpine zones in the Korean Peninsula. The aim of this research is to 1) identify climate factors controlling the range of cold-evergreens in the Korean Peninsula; and 2) predict the climate change effects on the range of cold-evergreens. We used multimodel inference based on combinations of climate variables to develop distribution models of cold-evergreens at a physiognomic-level. Presence/absence data of 12 species at 204 sites and 6 climatic factors, selected from among 23 candidate variables, were used for modeling. Model uncertainty was estimated by mapping a total variance calculated by adding the weighted average of within-model variation to the between-model variation. The range of cold-evergreens and model performance were validated by true skill statistics, the receiver operating characteristic curve and the kappa statistic. Climate change effects on the cold-evergreens were predicted according to the RCP 4.5 and RCP 8.5 scenarios. Multimodel inference approach excellently projected the spatial distribution of cold-evergreens (AUC = 0.95, kappa = 0.62 and TSS = 0.77). Temperature was a dominant factor in model-average estimates, while precipitation was minor. The climatic suitability increased from the southwest, lowland areas, to the northeast, high mountains. The range of cold-evergreens declined under climate change. Mountain-tops in the south and most of the area in the north remained suitable in 2050 and 2070 under the RCP 4.5 projection and 2050 under the RCP 8.5 projection. Only high-elevations in the northeastern Peninsula remained suitable under the RCP 8.5 projection. A northward and upper-elevational range shift indicates change in species composition at the alpine and subalpine ecosystems in the Korean Peninsula. PMID:26262755

A Case Study of Land Treatment in a Cold Climate-West Dover, Vermont,

DTIC Science & Technology

1982-12-01

Research & ADA124~i8Engineering Laboratory A case study of land treatment in a cold climate- West Dover, Vermont IT C;0 ~󈨜 03 09 052 CRREL Report 82...44 December 1982 A case study of land treatment in a cold climate- West Dover, Vermont J.R. Bouzoun, D.W. Meals and E.A. Cassell Prepared for OFFICE OF...4. TITLE (end SL : 5. TYPE OF REPORT & PERIOD COVERED A CASE STUDY OF LAND TREATMENT IN A COLD CLIMATE-WEST DOVER, VERMONT 6. PERFORMING ORG. REPORT

European vegetation during Marine Oxygen Isotope Stage-3

NASA Astrophysics Data System (ADS)

Huntley, Brian; Alfano, Mary J. o.; Allen, Judy R. M.; Pollard, Dave; Tzedakis, Polychronis C.; de Beaulieu, Jacques-Louis; Grüger, Eberhard; Watts, Bill

2003-03-01

European vegetation during representative "warm" and "cold" intervals of stage-3 was inferred from pollen analytical data. The inferred vegetation differs in character and spatial pattern from that of both fully glacial and fully interglacial conditions and exhibits contrasts between warm and cold intervals, consistent with other evidence for stage-3 palaeoenvironmental fluctuations. European vegetation thus appears to have been an integral component of millennial environmental fluctuations during stage-3; vegetation responded to this scale of environmental change and through feedback mechanisms may have had effects upon the environment. The pollen-inferred vegetation was compared with vegetation simulated using the BIOME 3.5 vegetation model for climatic conditions simulated using a regional climate model (RegCM2) nested within a coupled global climate and vegetation model (GENESIS-BIOME). Despite some discrepancies in detail, both approaches capture the principal features of the present vegetation of Europe. The simulated vegetation for stage-3 differs markedly from that inferred from pollen analytical data, implying substantial discrepancy between the simulated climate and that actually prevailing. Sensitivity analyses indicate that the simulated climate is too warm and probably has too short a winter season. These discrepancies may reflect incorrect specification of sea surface temperature or sea-ice conditions and may be exacerbated by vegetation-climate feedback in the coupled global model.

The Periglacial Environment, Permafrost, and Man.

ERIC Educational Resources Information Center

Price, Larry W.

This booklet contains resource material on cold climate phenomena and their influences on humans. It is intended for use by teachers and students in college-level geography courses as a supplement to existing textbooks and as a means of filling the gap between significant resources in geography and readily accessible materials. The material is…

Evolutionary stasis and lability in thermal physiology in a group of tropical lizards.

PubMed

Muñoz, Martha M; Stimola, Maureen A; Algar, Adam C; Conover, Asa; Rodriguez, Anthony J; Landestoy, Miguel A; Bakken, George S; Losos, Jonathan B

2014-03-07

Understanding how quickly physiological traits evolve is a topic of great interest, particularly in the context of how organisms can adapt in response to climate warming. Adjustment to novel thermal habitats may occur either through behavioural adjustments, physiological adaptation or both. Here, we test whether rates of evolution differ among physiological traits in the cybotoids, a clade of tropical Anolis lizards distributed in markedly different thermal environments on the Caribbean island of Hispaniola. We find that cold tolerance evolves considerably faster than heat tolerance, a difference that results because behavioural thermoregulation more effectively shields these organisms from selection on upper than lower temperature tolerances. Specifically, because lizards in very different environments behaviourally thermoregulate during the day to similar body temperatures, divergent selection on body temperature and heat tolerance is precluded, whereas night-time temperatures can only be partially buffered by behaviour, thereby exposing organisms to selection on cold tolerance. We discuss how exposure to selection on physiology influences divergence among tropical organisms and its implications for adaptive evolutionary response to climate warming.

Evolutionary stasis and lability in thermal physiology in a group of tropical lizards

PubMed Central

Muñoz, Martha M.; Stimola, Maureen A.; Algar, Adam C.; Conover, Asa; Rodriguez, Anthony J.; Landestoy, Miguel A.; Bakken, George S.; Losos, Jonathan B.

2014-01-01

Understanding how quickly physiological traits evolve is a topic of great interest, particularly in the context of how organisms can adapt in response to climate warming. Adjustment to novel thermal habitats may occur either through behavioural adjustments, physiological adaptation or both. Here, we test whether rates of evolution differ among physiological traits in the cybotoids, a clade of tropical Anolis lizards distributed in markedly different thermal environments on the Caribbean island of Hispaniola. We find that cold tolerance evolves considerably faster than heat tolerance, a difference that results because behavioural thermoregulation more effectively shields these organisms from selection on upper than lower temperature tolerances. Specifically, because lizards in very different environments behaviourally thermoregulate during the day to similar body temperatures, divergent selection on body temperature and heat tolerance is precluded, whereas night-time temperatures can only be partially buffered by behaviour, thereby exposing organisms to selection on cold tolerance. We discuss how exposure to selection on physiology influences divergence among tropical organisms and its implications for adaptive evolutionary response to climate warming. PMID:24430845

Genome-wide analysis of cold adaptation in indigenous Siberian populations.

PubMed

Cardona, Alexia; Pagani, Luca; Antao, Tiago; Lawson, Daniel J; Eichstaedt, Christina A; Yngvadottir, Bryndis; Shwe, Ma Than Than; Wee, Joseph; Romero, Irene Gallego; Raj, Srilakshmi; Metspalu, Mait; Villems, Richard; Willerslev, Eske; Tyler-Smith, Chris; Malyarchuk, Boris A; Derenko, Miroslava V; Kivisild, Toomas

2014-01-01

Following the dispersal out of Africa, where hominins evolved in warm environments for millions of years, our species has colonised different climate zones of the world, including high latitudes and cold environments. The extent to which human habitation in (sub-)Arctic regions has been enabled by cultural buffering, short-term acclimatization and genetic adaptations is not clearly understood. Present day indigenous populations of Siberia show a number of phenotypic features, such as increased basal metabolic rate, low serum lipid levels and increased blood pressure that have been attributed to adaptation to the extreme cold climate. In this study we introduce a dataset of 200 individuals from ten indigenous Siberian populations that were genotyped for 730,525 SNPs across the genome to identify genes and non-coding regions that have undergone unusually rapid allele frequency and long-range haplotype homozygosity change in the recent past. At least three distinct population clusters could be identified among the Siberians, each of which showed a number of unique signals of selection. A region on chromosome 11 (chr11:66-69 Mb) contained the largest amount of clustering of significant signals and also the strongest signals in all the different selection tests performed. We present a list of candidate cold adaption genes that showed significant signals of positive selection with our strongest signals associated with genes involved in energy regulation and metabolism (CPT1A, LRP5, THADA) and vascular smooth muscle contraction (PRKG1). By employing a new method that paints phased chromosome chunks by their ancestry we distinguish local Siberian-specific long-range haplotype signals from those introduced by admixture.

Sleep and stress in man: an approach through exercise and exposure to extreme environments.

PubMed

Buguet, A; Cespuglio, R; Radomski, M W

1998-05-01

In this paper, the effects of exercise on human sleep (in temperate, cold, and hot climates) are compared with those of exposure to extreme environments (tropical, polar climates). Exercise has two effect: (i) when the exercise load is too heavy or if the subject is not trained to the exercise conditions, the hypothalamo-pituitary-adrenocortical axis (HPA) is strongly activated (somatic stress reaction), and a diachronic (delayed) decrease in total sleep time and slow-wave sleep (SWS) occurs with a synchronic (concomitant) sleep disruption (such as a decrease in REM sleep); (ii) a diachronic enhancement of SWS and (or) REM sleep occurs during moderate training and in athletes, with a moderate HPA activation (neurogenic stress reaction). Heat acclimatization (neurogenic stress response) results in a diachronic increase in SWS, contrary to acute heat exposure (somatic stress) which leads to a diachronic decrease in SWS. Nocturnal cold exposure (somatic and (or) neurogenic stress) provokes a synchronic decrease in REM sleep with an activation of stress hormones, which are reduced by previous acclimation (neurogenic pathway); SWS remains undisturbed in the cold, as it occurs at the beginning of the night before body cooling. In conclusion, when the brain can deal with the stressor (neurogenic stress), diachronic increases in SWS and (or) REM sleep occur. When these "central" mechanisms are overloaded, the classical "somatic" stress reaction occurs with diachronic and synchronic disruptions of the sleep structure.

A low cost, high precision extreme/harsh cold environment, autonomous sensor data gathering and transmission platform.

NASA Astrophysics Data System (ADS)

Chetty, S.; Field, L. A.

2014-12-01

SWIMS III, is a low cost, autonomous sensor data gathering platform developed specifically for extreme/harsh cold environments. Arctic ocean's continuing decrease of summer-time ice is related to rapidly diminishing multi-year ice due to the effects of climate change. Ice911 Research aims to develop environmentally inert materials that when deployed will increase the albedo, enabling the formation and/preservation of multi-year ice. SWIMS III's sophisticated autonomous sensors are designed to measure the albedo, weather, water temperature and other environmental parameters. This platform uses low cost, high accuracy/precision sensors, extreme environment command and data handling computer system using satellite and terrestrial wireless solution. The system also incorporates tilt sensors and sonar based ice thickness sensors. The system is light weight and can be deployed by hand by a single person. This presentation covers the technical, and design challenges in developing and deploying these platforms.

Seasonal changes in gastric mucosal factors associated with peptic ulcer bleeding.

PubMed

Yuan, Xiao-Gang; Xie, Chuan; Chen, Jiang; Xie, Yong; Zhang, Kun-He; Lu, Nong-Hua

2015-01-01

A close association has been established between climate and peptic ulcer bleeding (PUB). The incidence of PUB in cold climates is significantly higher than that in hot climates. In this study, gastric mucosal damage and its barrier function (through associated barrier factors) in extreme climate conditions were examined to investigate the pathogenesis of PUB in extreme cold climates. Gastric juice and biopsy specimens were collected from 176 patients with peptic ulcer. Conventional hematoxylin and eosin staining was used to exclude malignant ulcers. Helicobacter pylori infections were detected by modified Giemsa staining. pH values of the gastric juice samples were obtained on-site by precise pH dipstick readings. The protein expression levels of heat shock protein (HSP) 70, occludin, nitric oxide synthase (NOS), epidermal growth factor (EGF) and EGF receptor (EGFR) in the gastric mucosa were detected by immunohistochemistry. No significant differences were identified between the high and low bleeding risk groups in the rates of H. pylori infection and the pH values of the gastric juices in the extreme hot or cold climates. Furthermore, no statistically significant differences were identified in the protein expression levels of occludin, NOS, EGF and EGFR between the high and low bleeding risk groups. In the extreme cold climate, the expression of HSP70 and the mucus thickness of the gastric antrum in the high bleeding risk group were significantly lower than those in the low bleeding risk group. The protein expression levels of occludin, HSP70, NOS and EGFR in the extreme cold climate were significantly lower than those in the extreme hot climate, whereas the gastric acid secretion was significantly higher in the extreme cold climate than that in the extreme hot climate. In conclusion, low expression of HSP70 in the gastric mucosa and reduced gastric mucus thickness may play key roles in the mechanism of PUB in extreme cold climates. The significant decrease in barrier factors and increase in damage in extreme cold climates may be associated with the seasonal pattern of peptic ulcers.

Seasonal changes in gastric mucosal factors associated with peptic ulcer bleeding

PubMed Central

YUAN, XIAO-GANG; XIE, CHUAN; CHEN, JIANG; XIE, YONG; ZHANG, KUN-HE; LU, NONG-HUA

2015-01-01

A close association has been established between climate and peptic ulcer bleeding (PUB). The incidence of PUB in cold climates is significantly higher than that in hot climates. In this study, gastric mucosal damage and its barrier function (through associated barrier factors) in extreme climate conditions were examined to investigate the pathogenesis of PUB in extreme cold climates. Gastric juice and biopsy specimens were collected from 176 patients with peptic ulcer. Conventional hematoxylin and eosin staining was used to exclude malignant ulcers. Helicobacter pylori infections were detected by modified Giemsa staining. pH values of the gastric juice samples were obtained on-site by precise pH dipstick readings. The protein expression levels of heat shock protein (HSP) 70, occludin, nitric oxide synthase (NOS), epidermal growth factor (EGF) and EGF receptor (EGFR) in the gastric mucosa were detected by immunohistochemistry. No significant differences were identified between the high and low bleeding risk groups in the rates of H. pylori infection and the pH values of the gastric juices in the extreme hot or cold climates. Furthermore, no statistically significant differences were identified in the protein expression levels of occludin, NOS, EGF and EGFR between the high and low bleeding risk groups. In the extreme cold climate, the expression of HSP70 and the mucus thickness of the gastric antrum in the high bleeding risk group were significantly lower than those in the low bleeding risk group. The protein expression levels of occludin, HSP70, NOS and EGFR in the extreme cold climate were significantly lower than those in the extreme hot climate, whereas the gastric acid secretion was significantly higher in the extreme cold climate than that in the extreme hot climate. In conclusion, low expression of HSP70 in the gastric mucosa and reduced gastric mucus thickness may play key roles in the mechanism of PUB in extreme cold climates. The significant decrease in barrier factors and increase in damage in extreme cold climates may be associated with the seasonal pattern of peptic ulcers. PMID:25452787

Tolerance to multiple climate stressors: A case study of Douglas-fir drought and cold hardiness

USGS Publications Warehouse

Bansal, Sheel; Harrington, Constance A; St. Clair, John Bradley

2016-01-01

Summary: 1. Drought and freeze events are two of the most common forms of climate extremes which result in tree damage or death, and the frequency and intensity of both stressors may increase with climate change. Few studies have examined natural covariation in stress tolerance traits to cope with multiple stressors among wild plant populations. 2. We assessed the capacity of coastal Douglas-fir (Pseudotsuga menziesii var. menziesii), an ecologically and economically important species in the northwestern USA, to tolerate both drought and cold stress on 35 populations grown in common gardens. We used principal components analysis to combine drought and cold hardiness trait data into generalized stress hardiness traits to model geographic variation in hardiness as a function of climate across the Douglas-fir range. 3. Drought and cold hardiness converged among populations along winter temperature gradients and diverged along summer precipitation gradients. Populations originating in regions with cold winters had relatively high tolerance to both drought and cold stress, which is likely due to overlapping adaptations for coping with winter desiccation. Populations from regions with dry summers had increased drought hardiness but reduced cold hardiness, suggesting a trade-off in tolerance mechanisms. 4. Our findings highlight the necessity to look beyond bivariate trait–climate relationships and instead consider multiple traits and climate variables to effectively model and manage for the impacts of climate change on widespread species.

Local atmospheric decoupling in complex topography alters climate change impacts

Treesearch

Christopher Daly; David R. Conklin; Michael H. Unsworth

2009-01-01

Cold air drainage and pooling occur in many mountain valleys, especially at night and during winter. Local climate regimes associated with frequent cold air pooling have substantial impacts on species phenology, distribution, and diversity. However, little is known about how the degree and frequency of cold air drainage and pooling will respond to a changing climate....

Implications of Martian Phyllosilicate Formation Conditions to the Early Climate on Mars

NASA Astrophysics Data System (ADS)

Bishop, J. L.; Baker, L.; Fairén, A. G.; Michalski, J. R.; Gago-Duport, L.; Velbel, M. A.; Gross, C.; Rampe, E. B.

2017-12-01

We propose that short-term warmer and wetter environments, occurring sporadically in a generally cold early Mars, enabled formation of phyllosilicate-rich outcrops on the surface of Mars without requiring long-term warm and wet conditions. We are investigating phyllosilicate formation mechanisms including CO2 and H2O budgets to provide constraints on the early martian climate. We have evaluated the nature and stratigraphy of phyllosilicate-bearing surface units on Mars based on i) phyllosilicate-forming environments on Earth, ii) phyllosilicate reactions in the lab, and iii) modeling experiments involving phyllosilicates and short-range ordered (SRO) materials. The type of phyllosilicates that form on Mars depends on temperature, water/rock ratio, acidity, salinity and available ions. Mg-rich trioctahedral smectite mixtures are more consistent with subsurface formation environments (crustal, hydrothermal or alkaline lakes) up to 400 °C and are not associated with martian surface environments. In contrast, clay profiles dominated by dioctahedral Al/Fe-smectites are typically formed in subaqueous or subaerial surface environments. We propose models describing formation of smectite-rich outcrops and laterally extensive vertical profiles of Fe/Mg-smectites, sulfates, and Al-rich clay assemblages formed in surface environments. Further, the presence of abundant SRO materials without phyllosilicates could mark the end of the last warm and wet episode on Mars supporting smectite formation. Climate Implications for Early Mars: Clay formation reactions proceed extremely slowly at cool temperatures. The thick smectite outcrops observed on Mars through remote sensing would require standing water on Mars for hundreds of millions of years if they formed in waters 10-15 °C. However, warmer temperatures could have enabled faster production of these smectite-rich beds. Sporadic warming episodes to 30-40 °C could have enabled formation of these smectites over only tens or hundreds of thousands of years instead. Our analyses of the phyllosilicate record on Mars point to a scenario of brief warm and wet conditions that accounts for formation of substantial smectite clays in many locations, geologic features resulting from liquid water across the planet, and a generally cold and dry climate.

Regional changes and global connections: monitoring climate variability and change in the western United States

Treesearch

Henry F. Diaz

2004-01-01

Mountain ecosystems of the Western United States are complex and include cold desert biomes, such as those found in Nevada; subpolar biomes found in the upper treeline zone; and tundra ecosystems, occurring above timberline. Many studies (for example, Thompson 2000) suggest that high-elevation environments, comprising glaciers, snow, permafrost, water, and the...

Jet Fuel Exposure and Neurological Health in Military Personnel

DTIC Science & Technology

2006-07-01

relationship between JP-8 fuel exposure and adverse neurological outcomes in military personnel working in a cold climate environment. The research...with hypothesized neurocognitive and neurophysiologic performance outcomes . The project has two phases: Tier I is to conduct onsite exposure ...AD_________________ Award Number: W81XWH-06-1-0105 TITLE: Jet Fuel Exposure and Neurological

Hot Mix Asphalt for Intersections in Hot Climates

DOT National Transportation Integrated Search

1998-03-01

Rutting of hot mix asphalt (HMA) pavement at or near intersections is very common both in cold and hot climates. Obviously, the problem is more acute in hot climates compared to cold climates because the stiffness of HMA decreases with increase in pa...

Cold-water coral carbonate mounds as unique palaeo-archives: the Plio-Pleistocene Challenger Mound record (NE Atlantic)

NASA Astrophysics Data System (ADS)

Thierens, M.; Browning, E.; Pirlet, H.; Loutre, M.-F.; Dorschel, B.; Huvenne, V. A. I.; Titschack, J.; Colin, C.; Foubert, A.; Wheeler, A. J.

2013-08-01

Through the interplay of a stabilising cold-water coral framework and a dynamic sedimentary environment, cold-water coral carbonate mounds create distinctive centres of bio-geological accumulation in often complex (continental margin) settings. The IODP Expedition 307 drilling of the Challenger Mound (eastern Porcupine Seabight; NE Atlantic) not only retrieved the first complete developmental history of a coral carbonate mound, it also exposed a unique, Early-Pleistocene sedimentary sequence of exceptional resolution along the mid-latitudinal NE Atlantic margin. In this study, a comprehensive assessment of the Challenger Mound as an archive of Quaternary palaeo-environmental change and long-term coral carbonate mound development is presented. New and existing environmental proxy records, including clay mineralogy, planktonic foraminifer and calcareous nannofossil biostratigraphy and assemblage counts, planktonic foraminifer oxygen isotopes and siliciclastic particle-size, are thereby discussed within a refined chronostratigraphic and climatic context. Overall, the development of the Challenger Mound shows a strong affinity to the Plio-Pleistocene evolution of the Northern Hemisphere climate system, albeit not being completely in phase with it. The two major oceanographic and climatic transitions of the Plio-Pleistocene - the Late Pliocene/Early Pleistocene intensification of continental ice-sheet development and the mid-Pleistocene transition to the more extremely variable and more extensively glaciated late Quaternary - mark two major thresholds in Challenger Mound development: its Late Pliocene (>2.74 Ma) origin and its Middle-Late Pleistocene to recent decline. Distinct surface-water perturbations (i.e. water-mass/polar front migrations, productivity changes, melt-water pulses) are identified throughout the sequence, which can be linked to the intensity and extent of ice development on the nearby British-Irish Isles since the earliest Pleistocene. Glaciation-induced shifts in surface-water primary productivity are thereby proposed to fundamentally control cold-water coral growth, which in turn influences on-mound sediment accumulation and, hence, coral carbonate mound development throughout the Pleistocene. As local factors, such as proximal ice-sheet dynamics and on-mound changes in cold-water coral density, significantly affected the development of the Challenger Mound, they can potentially explain the nature of its palaeo-record and its offsets with the periodicities of global climate variability. On the other hand, owing to this unique setting, a regionally exceptional, high-resolution palaeo-record of Early Pleistocene (ca 2.6 to 2.1 Ma) environmental change (including early British-Irish ice-sheet development), broadly in phase with the 41 ka-paced global climate system, is preserved in the lower Challenger Mound. All in all, the Challenger Mound record highlights the wider relevance of coral carbonate mound archives and their potential to capture unique records from dynamic (continental margin) environments.

The effects of climate change on heating energy consumption of office buildings in different climate zones in China

NASA Astrophysics Data System (ADS)

Meng, Fanchao; Li, Mingcai; Cao, Jingfu; Li, Ji; Xiong, Mingming; Feng, Xiaomei; Ren, Guoyu

2017-06-01

Climate plays an important role in heating energy consumption owing to the direct relationship between space heating and changes in meteorological conditions. To quantify the impact, the Transient System Simulation Program software was used to simulate the heating loads of office buildings in Harbin, Tianjin, and Shanghai, representing three major climate zones (i.e., severe cold, cold, and hot summer and cold winter climate zones) in China during 1961-2010. Stepwise multiple linear regression was performed to determine the key climatic parameters influencing heating energy consumption. The results showed that dry bulb temperature (DBT) is the dominant climatic parameter affecting building heating loads in all three climate zones across China during the heating period at daily, monthly, and yearly scales (R 2 ≥ 0.86). With the continuous warming climate in winter over the past 50 years, heating loads decreased by 14.2, 7.2, and 7.1 W/m2 in Harbin, Tianjin, and Shanghai, respectively, indicating that the decreasing rate is more apparent in severe cold climate zone. When the DBT increases by 1 °C, the heating loads decrease by 253.1 W/m2 in Harbin, 177.2 W/m2 in Tianjin, and 126.4 W/m2 in Shanghai. These results suggest that the heating energy consumption can be well predicted by the regression models at different temporal scales in different climate conditions owing to the high determination coefficients. In addition, a greater decrease in heating energy consumption in northern severe cold and cold climate zones may efficiently promote the energy saving in these areas with high energy consumption for heating. Particularly, the likely future increase in temperatures should be considered in improving building energy efficiency.

[Meteoadaptogenic properties of peptide drugs in healthy volunteers].

PubMed

Shabanov, P D; Ganapol'skiĭ, V P; Aleksandrov, P V

2007-01-01

The meteoadaptogenic properties of a series of drugs with peptide (cortexin, noopept, dilept) and nonpeptide (vinpotropil) structure were investigated in a climate thermobarocomplex (Tabay, Japan) on a group of healthy volunteers aged 20-24. All the studied drugs produced a meteoadaptogenic action, the extent of which depended on the environmental test conditions (overcooling, overheating, hypobaric hypoxia). Vinpotropil, optimizing a physiological component of the functional state, can be recommended as a meteoadaptogen for both cold and hot climate as well as for hypobaric hypoxia, where it improved the psychological component of the functional state. Cortexin is qualified as an adaptogen and actoprotector only for hypobaric hypoxia conditions (uplands). Noopept, affecting positively a psychological component of the functional state, can be used for rapid adaptation to both cold and hot climate. In the hot climate, noopept also enhanced the physical work capacity. Dilept mostly elevated the psychological component of the functional state and can be considered as a psychomotor enhancer and adaptogen. Therefore, all the drugs studied (vinpotropil, cortexin, noopept and dilept) can be recommended as the agents producing activation, support and recovery of the physical and psychological efficiency under rapidly changing environment conditions.

Climate, phylogeny and the ecological distribution of C4 grasses.

PubMed

Edwards, Erika J; Still, Christopher J

2008-03-01

'C4 photosynthesis' refers to a suite of traits that increase photosynthesis in high light and high temperature environments. Most C4 plants are grasses, which dominate tropical and subtropical grasslands and savannas but are conspicuously absent from cold growing season climates. Physiological attributes of C4 photosynthesis have been invoked to explain C4 grass biogeography; however, the pathway evolved exclusively in grass lineages of tropical origin, suggesting that the prevalence of C4 grasses in warm climates could be due to other traits inherited from their non-C4 ancestors. Here we investigate the relative influences of phylogeny and photosynthetic pathway in determining the ecological distributions of C4 grasses in Hawaii. We find that the restriction of C4 grasses to warmer areas is due largely to their evolutionary history as members of a warm-climate grass clade, but that the pathway does appear to confer a competitive advantage to grasses in more arid environments.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Byers, David A.; Henrikson, L. Suzann; Breslawski, Ryan P.

Previous archaeological research in southern Idaho has suggested that climate change over the past 8000 years was not dramatic enough to alter long-term subsistence practices in the region. However, recent isotopic analyses of bison remains from cold storage caves on the Snake River Plain contest this hypothesis. Our results, when examined against an archaeoclimate model, suggest that cold storage episodes coincided with drier, warmer phases that likely reduced forage and water, and thus limited the availability of bison on the open steppe. Within this context we build a risk model to illustrate how environment might have motivated cold storage behaviors.more » Caching bison in cold lava tubes would have mitigated both intra-annual and inter-annual food shortages under these conditions. This analysis also suggests that skeletal fat, more than meat, may have influenced the selection, transport and storage of bison carcass parts. We deciphered when and how cold storage caves which was used to provide a more comprehensive understanding of foraging behaviors in a broad range of hunting-gathering economies.« less

Ecogeographical associations between climate and human body composition: analyses based on anthropometry and skinfolds.

PubMed

Wells, Jonathan C K

2012-02-01

In the 19th century, two "ecogeographical rules" were proposed hypothesizing associations of climate with mammalian body size and proportions. Data on human body weight and relative leg length support these rules; however, it is unknown whether such associations are attributable to lean tissue (the heat-producing component) or fat (energy stores). Data on weight, height, and two skinfold thickness were obtained from the literature for 137 nonindustrialized populations, providing 145 male and 115 female individual samples. A variety of indices of adiposity and lean mass were analyzed. Preliminary analyses indicated secular increases in skinfolds in men but not women, and associations of age and height with lean mass in both sexes. Decreasing annual temperature was associated with increasing body mass index (BMI), and increasing triceps but not subscapular skinfold. After adjusting for skinfolds, decreasing temperature remained associated with increasing BMI. These results indicate that colder environments favor both greater peripheral energy stores, and greater lean mass. Contrasting results for triceps and subscapular skinfolds might be due to adaptive strategies either constraining central adiposity in cold environments to reduce cardiovascular risk, or favoring central adiposity in warmer environments to maintain energetic support of the immune system. Polynesian populations were analyzed separately and contradicted all of the climate trends, indicating support for the hypothesis that they are cold-adapted despite occupying a tropical region. It is unclear whether such associations emerge through natural selection or through trans-generational and life-course plasticity. These findings nevertheless aid understanding of the wide variability in human physique and adiposity. Copyright © 2011 Wiley Periodicals, Inc.

Genome-Wide Analysis of Cold Adaptation in Indigenous Siberian Populations

PubMed Central

Cardona, Alexia; Pagani, Luca; Antao, Tiago; Lawson, Daniel J.; Eichstaedt, Christina A.; Yngvadottir, Bryndis; Shwe, Ma Than Than; Wee, Joseph; Romero, Irene Gallego; Raj, Srilakshmi; Metspalu, Mait; Villems, Richard; Willerslev, Eske; Tyler-Smith, Chris; Malyarchuk, Boris A.; Derenko, Miroslava V.; Kivisild, Toomas

2014-01-01

Following the dispersal out of Africa, where hominins evolved in warm environments for millions of years, our species has colonised different climate zones of the world, including high latitudes and cold environments. The extent to which human habitation in (sub-)Arctic regions has been enabled by cultural buffering, short-term acclimatization and genetic adaptations is not clearly understood. Present day indigenous populations of Siberia show a number of phenotypic features, such as increased basal metabolic rate, low serum lipid levels and increased blood pressure that have been attributed to adaptation to the extreme cold climate. In this study we introduce a dataset of 200 individuals from ten indigenous Siberian populations that were genotyped for 730,525 SNPs across the genome to identify genes and non-coding regions that have undergone unusually rapid allele frequency and long-range haplotype homozygosity change in the recent past. At least three distinct population clusters could be identified among the Siberians, each of which showed a number of unique signals of selection. A region on chromosome 11 (chr11:66–69 Mb) contained the largest amount of clustering of significant signals and also the strongest signals in all the different selection tests performed. We present a list of candidate cold adaption genes that showed significant signals of positive selection with our strongest signals associated with genes involved in energy regulation and metabolism (CPT1A, LRP5, THADA) and vascular smooth muscle contraction (PRKG1). By employing a new method that paints phased chromosome chunks by their ancestry we distinguish local Siberian-specific long-range haplotype signals from those introduced by admixture. PMID:24847810

Conserved and narrow temperature limits in alpine insects: Thermal tolerance and supercooling points of the ice-crawlers, Grylloblatta (Insecta: Grylloblattodea: Grylloblattidae).

PubMed

Schoville, Sean D; Slatyer, Rachel A; Bergdahl, James C; Valdez, Glenda A

2015-07-01

For many terrestrial species, habitat associations and range size are dependent on physiological limits, which in turn may influence large-scale patterns of species diversity. The temperature range experienced by individuals is considered to shape the breadth of the thermal niche, with species occupying temporally and/or geographically stable climates tolerating a narrow temperature range. High-elevation environments experience large temperature fluctuations, with frequent periods below 0 °C, but Grylloblatta (Grylloblattodea: Grylloblattidae) occupy climatically stable microhabitats within this region. Here we test critical thermal limits and supercooling points for five Grylloblatta populations from across a large geographic area, to examine whether the stable microhabitats of this group are associated with a narrow thermal niche and assess their capacity to tolerate cold conditions. Thermal limits are highly conserved in Grylloblatta, despite substantial genetic divergence among populations spanning 1500 m elevation and being separated by over 500 km. Further, Grylloblatta show exceptionally narrow thermal limits compared to other insect taxa with little capacity to improve cold tolerance via plasticity. In contrast, upper thermal limits were significantly depressed by cold acclimation. Grylloblatta maintain coordinated movement until they freeze, and they die upon freezing. Convergence of the critical thermal minima, supercooling point and lower lethal limits point to adaptation to a cold but, importantly, constant thermal environment. These physiological data provide an explanation for the high endemism and patchy distribution of Grylloblatta, which relies on subterranean retreats to accommodate narrow thermal limits. These retreats are currently buffered from temperature fluctuations by snow cover, and a declining snowpack thus places Grylloblatta at risk of exposure to temperatures beyond its tolerance capacity. Copyright © 2015 Elsevier Ltd. All rights reserved.

Holocene cold storage practices on the eastern Snake River Plain: A risk-mitigation strategy for lean times

DOE PAGES

Byers, David A.; Henrikson, L. Suzann; Breslawski, Ryan P.

2016-06-04

Previous archaeological research in southern Idaho has suggested that climate change over the past 8000 years was not dramatic enough to alter long-term subsistence practices in the region. However, recent isotopic analyses of bison remains from cold storage caves on the Snake River Plain contest this hypothesis. Our results, when examined against an archaeoclimate model, suggest that cold storage episodes coincided with drier, warmer phases that likely reduced forage and water, and thus limited the availability of bison on the open steppe. Within this context we build a risk model to illustrate how environment might have motivated cold storage behaviors.more » Caching bison in cold lava tubes would have mitigated both intra-annual and inter-annual food shortages under these conditions. This analysis also suggests that skeletal fat, more than meat, may have influenced the selection, transport and storage of bison carcass parts. We deciphered when and how cold storage caves which was used to provide a more comprehensive understanding of foraging behaviors in a broad range of hunting-gathering economies.« less

A lacustrine record from Lop Nur, Xinjiang, China: Implications for paleoclimate change during Late Pleistocene

USGS Publications Warehouse

Chao, L.; Zicheng, P.; Dong, Y.; Weiguo, L.; Zhaofeng, Z.; Jianfeng, H.; Chenlin, C.

2009-01-01

Climate variability during the Late Pleistocene is studied from the proxies in core CK-2 drilled from the Luobei Depression (91??03???E, 40??47???N), Lop Nur in the eastern Tarim Basin, Xinjiang, China. Geophysical and geochemical properties, including magnetic susceptibility, granularity, chroma, carbonate content, loss on ignition and trace elements, have been determined to reconstruct the environmental evolution of the area during 32-9 ka BP. The chronology is established by uranium-thorium disequilibrium dating techniques. Our data suggest four paleoclimate stages, indicating glacial variations between cold-humid and warm-arid environments. A period of extreme humidity occurred during 31,900-19,200 yr BP is attributed the last glacial maximum (LGM). The period was followed by a warm-arid episode during 19,200-13,500 yr BP. Then a cold-humid interval during 13,500-12,700 yr BP may correspond to another cooling phases at high latitudes of the Northern Hemisphere. The last stage from 12,700 to 9000 yr BP has a trend that the climate turned warm and arid. The Lop Nur region is characterized by particularly humid stadials and arid interstadials. The climate variability in Lop Nur was constrained by global climate change because it is correlated with Dansgaard-Oeschger and Heinrich events, which were observed at the northern high latitudes. The synchroneity of the palaeoclimatic events suggested that cold air activity at the northern high latitudes was the most important factor that influenced the climate evolution in the Lop Nur region. A probable mechanism that involves the migration of westerly winds is proposed to interpret this synchroneity. ?? 2008 Elsevier Ltd.

Crop-model assisted phenomics and genome-wide association study for climate adaptation of indica rice. 2. Thermal stress and spikelet sterility.

PubMed

Dingkuhn, Michael; Pasco, Richard; Pasuquin, Julie Mae; Damo, Jean; Soulié, Jean-Christophe; Raboin, Louis-Marie; Dusserre, Julie; Sow, Abdoulaye; Manneh, Baboucarr; Shrestha, Suchit; Kretzschmar, Tobias

2017-07-10

Low night and high day temperatures during sensitive reproductive stages cause spikelet sterility in rice. Phenotyping of tolerance traits in the field is difficult because of temporal interactions with phenology and organ temperature differing from ambient. Physiological models can be used to separate these effects. A 203-accession indica rice diversity panel was phenotyped for sterility in ten environments in Senegal and Madagascar and climate data were recorded. Here we report on sterility responses while a companion study reported on phenology. The objectives were to improve the RIDEV model of rice thermal sterility, to estimate response traits by fitting model parameters, and to link the response traits to genomic regions through genome-wide association studies (GWAS). RIDEV captured 64% of variation of sterility when cold acclimation during vegetative stage was simulated, but only 38% when it was not. The RIDEV parameters gave more and stronger quantitative trait loci (QTLs) than index variables derived more directly from observation. The 15 QTLs identified at P<1 × 10-5 (33 at P<1 × 10-4) were related to sterility effects of heat, cold, cold acclimation, or unexplained causes (baseline sterility). Nine annotated genes were found on average within the 50% linkage disequilibrium (LD) region. Among them, one to five plausible candidate genes per QTL were identified based on known expression profiles (organ, stage, stress factors) and function. Meiosis-, development- and flowering-related genes were frequent, as well a stress signaling kinases and transcription factors. Putative epigenetic factors such as DNA methylases or histone-related genes were frequent in cold-acclimation QTLs, and positive-effect alleles were frequent in cold-tolerant highland rice from Madagascar. The results indicate that epigenetic control of acclimation may be important in indica rice genotypes adapted to cool environments. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Climate Change and Wildlife in the Northern Rockies Region [Chapter 9

Treesearch

Kevin S. McKelvey; Polly C. Buotte

2018-01-01

Temperature and moisture affect organisms through their operational environment and the thin boundary layer immediately above their tissues, and these effects are measured at short time scales. When a human (a mammal) wearing a dark insulative layer walks outdoors on a cold but sunny day, he or she feels warm because energy from the sun is interacting with the dark...

Cold water as a climate shield to preserve native trout through the 21st Century

Treesearch

Daniel J. Isaak; Michael K. Young; David Nagel; Dona Horan

2014-01-01

Native trout are culturally and ecologically important, but also likely to undergo widespread declines as the coldwater environments they require continue to shrink in association with global warming. Much can be done to preserve these fish but efficient planning and targeting of conservations resources has been hindered by a lack of broad-scale datasets and precise...

Astrobiology through the ages of Mars: the study of terrestrial analogues to understand the habitability of Mars.

PubMed

Fairén, Alberto G; Davila, Alfonso F; Lim, Darlene; Bramall, Nathan; Bonaccorsi, Rosalba; Zavaleta, Jhony; Uceda, Esther R; Stoker, Carol; Wierzchos, Jacek; Dohm, James M; Amils, Ricardo; Andersen, Dale; McKay, Christopher P

2010-10-01

Mars has undergone three main climatic stages throughout its geological history, beginning with a water-rich epoch, followed by a cold and semi-arid era, and transitioning into present-day arid and very cold desert conditions. These global climatic eras also represent three different stages of planetary habitability: an early, potentially habitable stage when the basic requisites for life as we know it were present (liquid water and energy); an intermediate extreme stage, when liquid solutions became scarce or very challenging for life; and the most recent stage during which conditions on the surface have been largely uninhabitable, except perhaps in some isolated niches. Our understanding of the evolution of Mars is now sufficient to assign specific terrestrial environments to each of these periods. Through the study of Mars terrestrial analogues, we have assessed and constrained the habitability conditions for each of these stages, the geochemistry of the surface, and the likelihood for the preservation of organic and inorganic biosignatures. The study of these analog environments provides important information to better understand past and current mission results as well as to support the design and selection of instruments and the planning for future exploratory missions to Mars.

Evaluation of cold workplaces: an overview of standards for assessment of cold stress.

PubMed

Holmér, Ingvar

2009-07-01

Many persons world wide are exposed to cold environments, either indoors for example in cold stores, or outdoors. Cold is a hazard to health and may affect safety and performance of work. Basis for the creation of safe and optimal working conditions may be obtained by the application of relevant international standards. ISO 11079 presents a method for evaluation of whole body heat balance. On the basis of climate and activity a required clothing insulation (IREQ) for heat balance is determined. For clothing with known insulation value an exposure time limited is calculated. ISO 11079 also includes criteria for assessment of local cooling. Finger temperatures should not be below 24 degrees C during prolonged exposures or 15 degrees C occasionally. Wind chill temperature indicates the risk of bare skin to freeze for combinations of wind and low temperatures. Special protection of airways is recommended at temperatures below -20 degrees C, in particular during heavy work. Additional standards are available describing evaluation strategies, work place observation checklists and checklist for medical screening. Risks associated with contact with cold surfaces can be evaluated with ISO 13732. The strategy and principles for assessment and prevention of cold stress are reviewed in this paper.

Millennial-scale variability during the last glacial in vegetation records from North America

USGS Publications Warehouse

Jiménez-Moreno, Gonzalo; Anderson, R. Scott; Desprat, S.; Grigg, L.D.; Grimm, E.C.; Heusser, L.E.; Jacobs, Brian F.; Lopez-Martinez, C.; Whitlock, C.L.; Willard, D.A.

2010-01-01

High-resolution pollen records from North America show that terrestrial environments were affected by Dansgaard-Oeschger (D-O) and Heinrich climate variability during the last glacial. In the western, more mountainous regions, these climate changes are generally observed in the pollen records as altitudinal movements of climate-sensitive plant species, whereas in the southeast, they are recorded as latitudinal shifts in vegetation. Heinrich (HS) and Greenland (GS) stadials are generally correlated with cold and dry climate and Greenland interstadials (GI) with warm-wet phases. The pollen records from North America confirm that vegetation responds rapidly to millennial-scale climate variability, although the difficulties in establishing independent age models for the pollen records make determination of the absolute phasing of the records to surface temperatures in Greenland somewhat uncertain. ?? 2009 Elsevier Ltd.

Seasonal Snow Cold Content Dynamics in the Alpine and Sub-Alpine, Niwot Ridge, Colorado, USA

NASA Astrophysics Data System (ADS)

Jennings, K. S.; Molotch, N. P.

2015-12-01

Cold content represents the energy required to warm a sub-freezing snowpack to an isothermal 0°C. Across daily and seasonal time scales it is a dynamic interplay between the forces of snowpack accumulation/cooling and warming. Cold content determines snowmelt timing and is an important component of the annual energy budget of mountain sites with seasonal snowpacks. However, little is understood about seasonal snowpack cold content dynamics as calculating cold content requires depth-weighted snowpack temperature and snow water equivalent (SWE) measurements, which are scarce. A spatially distributed network of snow pits has been sampled since 1993 at the Niwot Ridge Long Term Ecological Research site on the eastern slope of the Continental Divide in Colorado's Front Range mountains. This study uses data from 3 pit sites that have at least 8 years of observations and represent alpine and sub-alpine environments. For these pits, cold content is strongly related to SWE during the cold content accumulation phase, here defined as December, January, and February. Average peak cold content ranges between -2.5 MJ m-2 and -9.2 MJ m-2 for the three sites and is strongly related to peak SWE. On average, cold content reaches its maximum on February 26, which is 61 days before the average date of peak SWE (i.e., the snowpack's cold content is satisfied over an average of 61 days). At the alpine site, later peak cold content and SWE was observed relative to the lower elevation sub-alpine sites. Interestingly, the alpine site had a smaller gap between peak cold content and SWE (55 days versus 67 days for the alpine and sub-alpine sites, respectively). The gap between peak cold content and peak SWE is primarily a function of the increase in SWE between the two dates. Hence, persistent snowfall after the date of peak cold content can delay the onset of snowmelt even if peak cold content was relatively low. Improving our understanding of seasonal cold content dynamics in mountain environments will enable us to better model the future effects of climate change on snowmelt timing and associated hydrologic response.

Pollen record of the mid- to late-Holocene centennial climate change on the East coast of South Korea and its influential factors

NASA Astrophysics Data System (ADS)

Song, Bing; Yi, Sangheon; Jia, Hongjuan; Nahm, Wook-Hyun; Kim, Jin-Cheul; Lim, Jaesoo; Lee, Jin-Young; Sha, Longbin; Mao, Limi; Yang, Zhongyong; Nakanishi, Toshimichi; Hong, Wan; Li, Zhen

2018-01-01

To understand historical climate change in western Pacific coastal areas, a sediment core (SOJ-2) from the stable sedimentary environment of the Songjiho Lagoon on the east coast of South Korea was obtained for centennial-resolution palynological analysis. The ages of the SOJ-2 core is well controlled by carbon 14 dating with high-resolution accelerator mass spectrometry (AMS), and the results indicated a general warm to cold climate trend from the mid-Holocene to the present, which can be divided into two different stages: a warmer stage between 6842 and 1297 cal yr BP and a colder stage from 1297 cal yr BP to the present, with fluctuations during these stages. The climate was wetter from 6842 to 6227 cal yr BP and 4520 to 1297 cal yr BP and was drier from 6227 to 4520 cal yr BP. The climate changed to cold and dry during the period from 1297-425 cal yr BP. The impact of human activity on the climate began at approximately 1297 cal yr BP and became pronounced starting in 425 cal yr BP. The general cooling trend may represent a response to decreasing solar insolation; however, the relative dryness or wetness of the climate may have been co-determined by westerlies and the East Asian summer monsoon (EASM). The climate had a teleconnection with the North Atlantic region, resulting from changes in solar activity. Nevertheless, EI Niño-Southern Oscillation (ENSO) activity played an important role in impacting the EASM changes in western Pacific coastal areas.

Polar Marine Microorganisms and Climate Change.

PubMed

Verde, C; Giordano, D; Bellas, C M; di Prisco, G; Anesio, A M

2016-01-01

The large diversity of marine microorganisms harboured by oceans plays an important role in planet sustainability by driving globally important biogeochemical cycles; all primary and most secondary production in the oceans is performed by microorganisms. The largest part of the planet is covered by cold environments; consequently, cold-adapted microorganisms have crucial functional roles in globally important environmental processes and biogeochemical cycles cold-adapted extremophiles are a remarkable model to shed light on the molecular basis of survival at low temperature. The indigenous populations of Antarctic and Arctic microorganisms are endowed with genetic and physiological traits that allow them to live and effectively compete at the temperatures prevailing in polar regions. Some genes, e.g. glycosyltransferases and glycosylsynthetases involved in the architecture of the cell wall, may have been acquired/retained during evolution of polar strains or lost in tropical strains. This present work focusses on temperature and its role in shaping microbial adaptations; however, in assessing the impacts of climate changes on microbial diversity and biogeochemical cycles in polar oceans, it should not be forgotten that physiological studies need to include the interaction of temperature with other abiotic and biotic factors. © 2016 Elsevier Ltd All rights reserved.

Temperate Mountain Forest Biodiversity under Climate Change: Compensating Negative Effects by Increasing Structural Complexity

PubMed Central

Braunisch, Veronika; Coppes, Joy; Arlettaz, Raphaël; Suchant, Rudi; Zellweger, Florian; Bollmann, Kurt

2014-01-01

Species adapted to cold-climatic mountain environments are expected to face a high risk of range contractions, if not local extinctions under climate change. Yet, the populations of many endothermic species may not be primarily affected by physiological constraints, but indirectly by climate-induced changes of habitat characteristics. In mountain forests, where vertebrate species largely depend on vegetation composition and structure, deteriorating habitat suitability may thus be mitigated or even compensated by habitat management aiming at compositional and structural enhancement. We tested this possibility using four cold-adapted bird species with complementary habitat requirements as model organisms. Based on species data and environmental information collected in 300 1-km2 grid cells distributed across four mountain ranges in central Europe, we investigated (1) how species’ occurrence is explained by climate, landscape, and vegetation, (2) to what extent climate change and climate-induced vegetation changes will affect habitat suitability, and (3) whether these changes could be compensated by adaptive habitat management. Species presence was modelled as a function of climate, landscape and vegetation variables under current climate; moreover, vegetation-climate relationships were assessed. The models were extrapolated to the climatic conditions of 2050, assuming the moderate IPCC-scenario A1B, and changes in species’ occurrence probability were quantified. Finally, we assessed the maximum increase in occurrence probability that could be achieved by modifying one or multiple vegetation variables under altered climate conditions. Climate variables contributed significantly to explaining species occurrence, and expected climatic changes, as well as climate-induced vegetation trends, decreased the occurrence probability of all four species, particularly at the low-altitudinal margins of their distribution. These effects could be partly compensated by modifying single vegetation factors, but full compensation would only be achieved if several factors were changed in concert. The results illustrate the possibilities and limitations of adaptive species conservation management under climate change. PMID:24823495

Temperate mountain forest biodiversity under climate change: compensating negative effects by increasing structural complexity.

PubMed

Braunisch, Veronika; Coppes, Joy; Arlettaz, Raphaël; Suchant, Rudi; Zellweger, Florian; Bollmann, Kurt

2014-01-01

Species adapted to cold-climatic mountain environments are expected to face a high risk of range contractions, if not local extinctions under climate change. Yet, the populations of many endothermic species may not be primarily affected by physiological constraints, but indirectly by climate-induced changes of habitat characteristics. In mountain forests, where vertebrate species largely depend on vegetation composition and structure, deteriorating habitat suitability may thus be mitigated or even compensated by habitat management aiming at compositional and structural enhancement. We tested this possibility using four cold-adapted bird species with complementary habitat requirements as model organisms. Based on species data and environmental information collected in 300 1-km2 grid cells distributed across four mountain ranges in central Europe, we investigated (1) how species' occurrence is explained by climate, landscape, and vegetation, (2) to what extent climate change and climate-induced vegetation changes will affect habitat suitability, and (3) whether these changes could be compensated by adaptive habitat management. Species presence was modelled as a function of climate, landscape and vegetation variables under current climate; moreover, vegetation-climate relationships were assessed. The models were extrapolated to the climatic conditions of 2050, assuming the moderate IPCC-scenario A1B, and changes in species' occurrence probability were quantified. Finally, we assessed the maximum increase in occurrence probability that could be achieved by modifying one or multiple vegetation variables under altered climate conditions. Climate variables contributed significantly to explaining species occurrence, and expected climatic changes, as well as climate-induced vegetation trends, decreased the occurrence probability of all four species, particularly at the low-altitudinal margins of their distribution. These effects could be partly compensated by modifying single vegetation factors, but full compensation would only be achieved if several factors were changed in concert. The results illustrate the possibilities and limitations of adaptive species conservation management under climate change.

EVermont Renewable Hydrogen Production and Transportation Fueling System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garabedian, Harold T.

2008-03-30

A great deal of research funding is being devoted to the use of hydrogen for transportation fuel, particularly in the development of fuel cell vehicles. When this research bears fruit in the form of consumer-ready vehicles, will the fueling infrastructure be ready? Will the required fueling systems work in cold climates as well as they do in warm areas? Will we be sure that production of hydrogen as the energy carrier of choice for our transit system is the most energy efficient and environmentally friendly option? Will consumers understand this fuel and how to handle it? Those are questions addressedmore » by the EVermont Wind to Wheels Hydrogen Project: Sustainable Transportation. The hydrogen fueling infrastructure consists of three primary subcomponents: a hydrogen generator (electrolyzer), a compression and storage system, and a dispenser. The generated fuel is then used to provide transportation as a motor fuel. EVermont Inc., started in 1993 by then governor Howard Dean, is a public-private partnership of entities interested in documenting and advancing the performance of advanced technology vehicles that are sustainable and less burdensome on the environment, especially in areas of cold climates, hilly terrain and with rural settlement patterns. EVermont has developed a demonstration wind powered hydrogen fuel producing filling system that uses electrolysis, compression to 5000 psi and a hydrogen burning vehicle that functions reliably in cold climates. And that fuel is then used to meet transportation needs in a hybrid electric vehicle whose internal combustion engine has been converted to operate on hydrogen Sponsored by the DOE EERE Hydrogen, Fuel Cells & Infrastructure Technologies (HFC&IT) Program, the purpose of the project is to test the viability of sustainably produced hydrogen for use as a transportation fuel in a cold climate with hilly terrain and rural settlement patterns. Specifically, the project addresses the challenge of building a renewable transportation energy capable system. The prime energy for this project comes from an agreement with a wind turbine operator.« less

Life on the edge: insect ecology in arctic environments.

PubMed

Strathdee, A T; Bale, J S

1998-01-01

The restricted Arctic insect fauna is usually explained by a lack of recolonization since the last glacial period, inadequate supply of suitable resources, or insufficient adaptation to such a harsh environment. These hypotheses and others that attempt to explain the latitudinal gradient of species distributions and abundance are reviewed. Arctic habitats available to insects are strongly heterogeneous, requiring a similarly diverse array of adaptive responses, characteristic of those species that have colonized and survived in such a stressful climate. Important adaptations in morphology (size, wings), behavior (activity patterns, thermoregulation), life cycles, and ecophysiology (cold hardiness, anaerobiosis, desiccation resistance) are discussed. The current focus of global climate change research on polar regions is identified, particularly the opportunity to study fundamental ecological processes and spatial dynamics in the relatively simple Arctic ecosystems.

Is climate change mitigation the best use of desert shrublands?

Treesearch

Susan E. Meyer

2011-01-01

In a world where the metrics of the carbon economy have become a major issue, it may come as a surprise that intact cold desert shrublands can sequester significant amounts of carbon, both as biomass and in the form of SOC (soil organic carbon). Xerophytic shrubs invest heavily in belowground biomass, placing fixed carbon in an environment where it turns over only very...

Medical Aspects of Survival: Training for Aircrew

DTIC Science & Technology

1983-01-01

requirements for food and water. b. The environment - terrain, climate , flora and fauna, friendly or neutral natives, distance from friendly forces...the discomforts of colds and upper respiratory deseases , and at best, will just take the edge off severe pain. They should be taken, however, if...injury, either mechanical or emotional. Whilst the circula- tory changes initially favour body resistance to the injury by ensuring adequate blood

Range-wide conservation of Pinus aristata: A genetic collection with ecological context for proactive management today and resources for tomorrow

Treesearch

Anna W. Schoettle; Jonathan C. Coop

2017-01-01

Tree species are highly vulnerable to anthropogenic environmental change, and are increasingly being challenged by non-native pests and climate change. Rocky Mountain bristlecone pines are long-lived, exhibit delayed maturation, have low genetic diversity, and inhabit cold, high-elevation environments. They are threatened by the non-native disease white pine blister...

Extreme climate, rather than population history, explains mid-facial morphology of Northern Asians.

PubMed

Evteev, Andrej; Cardini, Andrea L; Morozova, Irina; O'Higgins, Paul

2014-03-01

Previous studies have examined mid-facial cold adaptation among either widely dispersed and genetically very diverse groups of humans isolated for tens of thousands of years, or among very closely related groups spread over climatically different regions. Here we present a study of one East Asian and seven North Asian populations in which we examine the evidence for convergent adaptations of the mid-face to a very cold climate. Our findings indicate that mid-facial morphology is strongly associated with climatic variables that contrast the temperate climate of East Asians and the very cold and dry climate of North Asians. This is also the case when either maxillary or nasal cavity measurements are considered alone. The association remains significant when mtDNA distances among populations are taken into account. The morphological contrasts between populations are consistent with physiological predictions and prior studies of mid-facial cold adaptation in more temperate regions, but among North Asians there appear to be some previously undescribed morphological features that might be considered as adaptive to extreme cold. To investigate this further, analyses of the seven North Asian populations alone suggest that mid-facial morphology remains strongly associated with climate, particularly winter precipitation, contrasting coastal Arctic and continental climates. However, the residual covariation among North Asian mid-facial morphology and climate when genetic distances are considered, is not significant. These findings point to modern adaptations to extreme climate that might be relevant to our understanding of the mid-facial morphology of fossil hominins that lived during glaciations. Copyright © 2013 Wiley Periodicals, Inc.

Raising of Operating a Motor Vehicle Effects on Environment in Winter

NASA Astrophysics Data System (ADS)

Ertman, S. A.; Ertman, J. A.; Zakharov, D. A.

2016-08-01

Severe low-temperature conditions, in which considerable part of Russian Motor Park is operated, affect vehicles negatively. Cold weather causes higher fuel consumption and C02 emissions always. It is because of temperature profile changing of automobile motors, other systems and materials. For enhancement of car operation efficiency in severe winter environment the dependency of engine warm-up and cooling time on ambient air temperature and wind speed described by multifactorial mathematical models is established. -On the basis of experimental research it was proved that the coolant temperature constitutes the engine representative temperature and may be used as representative temperature of engine at large. The model of generation of integrated index for vehicle adaptability to winter operating conditions by temperature profile of engines was developed. the method for evaluation of vehicle adaptability to winter operating conditions by temperature profile of engines allows to decrease higher fuel consumption in cold climate.

Characteristics of organic soil in black spruce forests: Implications for the application of land surface and ecosystem models in cold regions

USGS Publications Warehouse

Yi, S.; Manies, K.; Harden, J.; McGuire, A.D.

2009-01-01

Soil organic layers (OL) play an important role in landatmosphere exchanges of water, energy and carbon in cold environments. The proper implementation of OL in land surface and ecosystem models is important for predicting dynamic responses to climate warming. Based on the analysis of OL samples of black spruce (Picea mariana), we recommend that implementation of OL for cold regions modeling: (1) use three general organic horizon types (live, fibrous, and amorphous) to represent vertical soil heterogeneity; (2) implement dynamics of OL over the course of disturbance, as there are significant differences of OL thickness between young and mature stands; and (3) use two broad drainage classes to characterize spatial heterogeneity, as there are significant differences in OL thickness between dry and wet sites. Implementation of these suggestions into models has the potential to substantially improve how OL dynamics influence variability in surface temperature and soil moisture in cold regions. Copyright 2009 by the American Geophys.ical Union.

Conditional cold avoidance drives between-population variation in germination behaviour in Calluna vulgaris.

PubMed

Spindelböck, Joachim P; Cook, Zoë; Daws, Matthew I; Heegaard, Einar; Måren, Inger E; Vandvik, Vigdis

2013-09-01

Across their range, widely distributed species are exposed to a variety of climatic and other environmental conditions, and accordingly may display variation in life history strategies. For seed germination in cold climates, two contrasting responses to variation in winter temperature have been documented: first, an increased ability to germinate at low temperatures (cold tolerance) as winter temperatures decrease, and secondly a reduced ability to germinate at low temperatures (cold avoidance) that concentrates germination towards the warmer parts of the season. Germination responses were tested for Calluna vulgaris, the dominant species of European heathlands, from ten populations collected along broad-scale bioclimatic gradients (latitude, altitude) in Norway, covering a substantial fraction of the species' climatic range. Incubation treatments varied from 10 to 25 °C, and germination performance across populations was analysed in relation to temperature conditions at the seed collection locations. Seeds from all populations germinated rapidly and to high final percentages under the warmer incubation temperatures. Under low incubation temperatures, cold-climate populations had significantly lower germination rates and percentages than warm-climate populations. While germination rates and percentages also increased with seed mass, seed mass did not vary along the climatic gradients, and therefore did not explain the variation in germination responses. Variation in germination responses among Calluna populations was consistent with increased temperature requirements for germination towards colder climates, indicating a cold-avoidance germination strategy conditional on the temperature at the seeds' origin. Along a gradient of increasing temperatures this suggests a shift in selection pressures on germination from climatic adversity (i.e. low temperatures and potential frost risk in early or late season) to competitive performance and better exploitation of the entire growing season.

Conditional cold avoidance drives between-population variation in germination behaviour in Calluna vulgaris

PubMed Central

Spindelböck, Joachim P.; Cook, Zoë; Daws, Matthew I.; Heegaard, Einar; Måren, Inger E.; Vandvik, Vigdis

2013-01-01

Background and Aims Across their range, widely distributed species are exposed to a variety of climatic and other environmental conditions, and accordingly may display variation in life history strategies. For seed germination in cold climates, two contrasting responses to variation in winter temperature have been documented: first, an increased ability to germinate at low temperatures (cold tolerance) as winter temperatures decrease, and secondly a reduced ability to germinate at low temperatures (cold avoidance) that concentrates germination towards the warmer parts of the season. Methods Germination responses were tested for Calluna vulgaris, the dominant species of European heathlands, from ten populations collected along broad-scale bioclimatic gradients (latitude, altitude) in Norway, covering a substantial fraction of the species' climatic range. Incubation treatments varied from 10 to 25 °C, and germination performance across populations was analysed in relation to temperature conditions at the seed collection locations. Key Results Seeds from all populations germinated rapidly and to high final percentages under the warmer incubation temperatures. Under low incubation temperatures, cold-climate populations had significantly lower germination rates and percentages than warm-climate populations. While germination rates and percentages also increased with seed mass, seed mass did not vary along the climatic gradients, and therefore did not explain the variation in germination responses. Conclusions Variation in germination responses among Calluna populations was consistent with increased temperature requirements for germination towards colder climates, indicating a cold-avoidance germination strategy conditional on the temperature at the seeds' origin. Along a gradient of increasing temperatures this suggests a shift in selection pressures on germination from climatic adversity (i.e. low temperatures and potential frost risk in early or late season) to competitive performance and better exploitation of the entire growing season. PMID:23884396

Short-lived high-amplitude cooling on Svalbard during the Dark Ages

NASA Astrophysics Data System (ADS)

van der Bilt, Willem; D`Andrea, William; Bakke, Jostein; Balascio, Nicholas; Werner, Johannes; Hoek, Wim

2016-04-01

As the paradigm of a stable Holocene climate has shifted, an increasing number of high-resolution proxy timeseries reveal dynamic conditions, characterized by high-amplitude climate shifts. Some of these events occurred during historical times and allow us to study the interaction between environmental and cultural change, providing valuable lessons for the near future. These include the Dark Ages Cold Period (DACP) between 300 and 800 AD, a period marked by political upheaval and climate instability that remains poorly investigated. Here, we present two temperature reconstructions from the High Arctic Svalbard Archipelago. To this end, we applied the established alkenone-based UK37 paleothermometer on sediments from two lakes on western Spitsbergen, Lake Hajeren and Lake Hakluyt. The Arctic is presently warming twice as fast as the global average and proxy data as well as model simulations suggest that this amplified response is characteristic for regional climate. The Arctic therefore provides a uniquely sensitive environment to study relatively modest climate shifts, like the DACP, that may not be adequately captured at lower-latitude sites. Owing to undisturbed sediments, a high sampling resolution and robust chronological control, the presented reconstructions resolve the attendant sub-centennial-scale climate shifts. Our findings suggest that the DACP marks a cold spell within the cool Neoglacial period, which started some 4 ka BP on Svalbard. Close investigation reveals a distinct temperature minimum around 500 AD that is reproduced in another alkenone-based temperature reconstruction from a nearby lake. At ± 1.75 °C, cooling underlines the sensitivity of Arctic climate as well as the magnitude of the DACP.

Towards a wearable sensor system for continuous occupational cold stress assessment

PubMed Central

AUSTAD, Hanne; WIGGEN, Øystein; FÆREVIK, Hilde; SEEBERG, Trine M.

2018-01-01

This study investigated the usefulness of continuous sensor data for improving occupational cold stress assessment. Eleven volunteer male subjects completed a 90–120-min protocol in cold environments, consisting of rest, moderate and hard work. Biomedical data were measured using a smart jacket with integrated temperature, humidity and activity sensors, in addition to a custom-made sensor belt worn around the chest. Other relevant sensor data were measured using commercially available sensors. The study aimed to improve decision support for workers in cold climates, by taking advantage of the information provided by data from the rapidly growing market of wearable sensors. Important findings were that the subjective thermal sensation did not correspond to the measured absolute skin temperature and that large differences were observed in both metabolic energy production and skin temperatures under identical exposure conditions. Temperature, humidity, activity and heart rate were found to be relevant parameters for cold stress assessment, and the locations of the sensors in the prototype jacket were adequate. The study reveals the need for cold stress assessment and indicates that a generalised approached is not sufficient to assess the stress on an individual level. PMID:29353859

Incorporating Cold-Air Pooling into Downscaled Climate Models Increases Potential Refugia for Snow-Dependent Species within the Sierra Nevada Ecoregion, CA

PubMed Central

Curtis, Jennifer A.; Flint, Lorraine E.; Flint, Alan L.; Lundquist, Jessica D.; Hudgens, Brian; Boydston, Erin E.; Young, Julie K.

2014-01-01

We present a unique water-balance approach for modeling snowpack under historic, current and future climates throughout the Sierra Nevada Ecoregion. Our methodology uses a finer scale (270 m) than previous regional studies and incorporates cold-air pooling, an atmospheric process that sustains cooler temperatures in topographic depressions thereby mitigating snowmelt. Our results are intended to support management and conservation of snow-dependent species, which requires characterization of suitable habitat under current and future climates. We use the wolverine (Gulo gulo) as an example species and investigate potential habitat based on the depth and extent of spring snowpack within four National Park units with proposed wolverine reintroduction programs. Our estimates of change in spring snowpack conditions under current and future climates are consistent with recent studies that generally predict declining snowpack. However, model development at a finer scale and incorporation of cold-air pooling increased the persistence of April 1st snowpack. More specifically, incorporation of cold-air pooling into future climate projections increased April 1st snowpack by 6.5% when spatially averaged over the study region and the trajectory of declining April 1st snowpack reverses at mid-elevations where snow pack losses are mitigated by topographic shading and cold-air pooling. Under future climates with sustained or increased precipitation, our results indicate a high likelihood for the persistence of late spring snowpack at elevations above approximately 2,800 m and identify potential climate refugia sites for snow-dependent species at mid-elevations, where significant topographic shading and cold-air pooling potential exist. PMID:25188379

Incorporating cold-air pooling into downscaled climate models increases potential refugia for snow-dependent species within the Sierra Nevada Ecoregion, CA

USGS Publications Warehouse

Curtis, Jennifer A.; Flint, Lorraine E.; Flint, Alan L.; Lundquist, Jessica D.; Hudgens, Brian; Boydston, Erin E.; Young, Julie K.

2014-01-01

We present a unique water-balance approach for modeling snowpack under historic, current and future climates throughout the Sierra Nevada Ecoregion. Our methodology uses a finer scale (270 m) than previous regional studies and incorporates cold-air pooling, an atmospheric process that sustains cooler temperatures in topographic depressions thereby mitigating snowmelt. Our results are intended to support management and conservation of snow-dependent species, which requires characterization of suitable habitat under current and future climates. We use the wolverine (Gulo gulo) as an example species and investigate potential habitat based on the depth and extent of spring snowpack within four National Park units with proposed wolverine reintroduction programs. Our estimates of change in spring snowpack conditions under current and future climates are consistent with recent studies that generally predict declining snowpack. However, model development at a finer scale and incorporation of cold-air pooling increased the persistence of April 1st snowpack. More specifically, incorporation of cold-air pooling into future climate projections increased April 1st snowpack by 6.5% when spatially averaged over the study region and the trajectory of declining April 1st snowpack reverses at mid-elevations where snow pack losses are mitigated by topographic shading and cold-air pooling. Under future climates with sustained or increased precipitation, our results indicate a high likelihood for the persistence of late spring snowpack at elevations above approximately 2,800 m and identify potential climate refugia sites for snow-dependent species at mid-elevations, where significant topographic shading and cold-air pooling potential exist.

The cold climate geomorphology of the Eastern Cape Drakensberg: A reevaluation of past climatic conditions during the last glacial cycle in Southern Africa

NASA Astrophysics Data System (ADS)

Mills, S. C.; Barrows, T. T.; Telfer, M. W.; Fifield, L. K.

2017-02-01

Southern Africa is located in a unique setting for investigating past cold climate geomorphology over glacial-interglacial timescales. It lies at the junction of three of the world's major oceans and is affected by subtropical and temperate circulation systems, therefore recording changes in Southern Hemisphere circulation patterns. Cold climate landforms are very sensitive to changes in climate and thus provide an opportunity to investigate past changes in this region. The proposed existence of glaciers in the high Eastern Cape Drakensberg mountains, together with possible rock glaciers, has led to the suggestion that temperatures in this region were as much as 10-17 °C lower than present. Such large temperature depressions are inconsistent with many other palaeoclimatic proxies in Southern Africa. This paper presents new field observations and cosmogenic nuclide exposure ages from putative cold climate landforms. We discuss alternative interpretations for the formation of the landforms and confirm that glaciers were absent in the Eastern Cape Drakensberg during the last glaciation. However, we find widespread evidence for periglacial activity down to an elevation of 1700 m asl, as illustrated by extensive solifluction deposits, blockstreams, and stone garlands. These periglacial deposits suggest that the climate was significantly colder ( 6 °C) during the Last Glacial Maximum, in keeping with other climate proxy records from the region, but not cold enough to initiate or sustain glaciers or rock glaciers.

Cold Climate Foundation Retrofit Experimental Hygrothermal Performance: Cloquet Residential Research Facility Laboratory Results

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goldberg, Louise F.; Harmon, Anna C.

2015-04-01

Thermal and moisture problems in existing basements create a unique challenge because the exterior face of the wall is not easily or inexpensively accessible. This approach addresses thermal and moisture management from the interior face of the wall without disturbing the exterior soil and landscaping. the interior and exterior environments. This approach has the potential for improving durability, comfort, and indoor air quality. This project was funded jointly by the National Renewable Energy Laboratory (NREL) and Oak Ridge National Laboratory (ORNL). ORNL focused on developing a full basement wall system experimental database to enable others to validate hygrothermal simulation codes.more » NREL focused on testing the moisture durability of practical basement wall interior insulation retrofit solutions for cold climates. The project has produced a physically credible and reliable long-term hygrothermal performance database for retrofit foundation wall insulation systems in zone 6 and 7 climates that are fully compliant with the performance criteria in the 2009 Minnesota Energy Code. The experimental data were configured into a standard format that can be published online and that is compatible with standard commercially available spreadsheet and database software.« less

Climate refugia: The physical, hydrologic and disturbance basis

NASA Astrophysics Data System (ADS)

Holden, Z. A.; Maneta, M. P.; Forthofer, J.

2015-12-01

Projected changes in global climate and associated shifts in vegetation have increased interest in understanding species persistence at local scales. We examine the climatic and physical factors that could mediate changes in the distribution of vegetation in regions of complex topography. Using massive networks of low-cost temperature and humidity sensors, we developed topographically-resolved daily historical gridded temperature data for the US Northern Rockies. We used the WindNinja model to create daily historical wind speed maps across the same domain. Using a spatially distributed ecohydrology model (ECH2O) we examine separately the sensitivity of modeled evapotranspiration and soil moisture to wind, radiation, soil properties, minimum temperature and humidity. A suite of physical factors including lower wind speeds, cold air drainage, solar shading and increased soil depth reduce evapotranspiration and increase late season moisture availability in valley bottoms. Evapotranspiration shows strong sensitivity to spatial variability in surface wind speed, suggesting that sheltering effects from winds may be an important factor contributing to mountain refugia. Fundamental to our understanding of patterns of vegetation change is the role of stand-replacing wildfires, which modify the physical environment and subsequent patterns of species persistence and recruitment. Using satellite-derived maps of burn severity for recent fires in the US Northern Rockies we examined relationships between wind speed, cold air drainage potential and soil depth and the occurrence of unburned and low severity fire. Severe fire is less likely to occur in areas with high cold air drainage potential and low wind speeds, suggesting that sheltered valley bottoms have mediated the severity of recent wildfires. Our finding highlight the complex physical mechanisms by which mountain weather and climate mediate fire-induced vegetation changes in the US Northern Rocky Mountains.

Climate and Creativity: Cold and Heat Trigger Invention and Innovation in Richer Populations

ERIC Educational Resources Information Center

Van de Vliert, Evert; Murray, Damian R.

2018-01-01

Nobel laureates, technological pioneers, and innovative entrepreneurs are unequally distributed across the globe. Their density increases in regions toward the North Pole, toward the South Pole, and very close to the Equator. This geographic anomaly led us to explore whether stressful demands of climatic cold and climatic heat (imposed…

Multilocus patterns of nucleotide diversity and divergence reveal positive selection at candidate genes related to cold hardiness in coastal Douglas Fir (Pseudotsuga menziesii var. menziesii).

Treesearch

A. Eckert; J. Wegrzyn; B. Pande; K. Jermstad; J. Lee; J. Liechty; B. Tearse; K. Krutovsky; D. Neale

2009-01-01

Forest trees exhibit remarkable adaptations to their environments. The genetic basis for phenotypic adaptation to climatic gradients has been established through a long history of common garden, provenance, and genecological studies. The identities of genes underlying these traits, however, have remained elusive and thus so have the patterns of adaptive molecular...

Work climate and work load measurement in production room of Batik Merak Manis Laweyan

NASA Astrophysics Data System (ADS)

Suhardi, Bambang; Simanjutak, Sry Yohana; Laksono, Pringgo Widyo; Herjunowibowo, Dewanto

2017-11-01

The work environment is everything around the labours that can affect them in the exercise of duties and work that is charged. In a work environment, there are workplace climate and workload which affect the labour in force carrying out its work. The working climate is one of the physical factors that could potentially cause health problems towards labour at extreme conditions of hot and cold that exceed the threshold limit value allowed by the standards of health. The climate works closely related to the workload accepted by workers in the performance of their duties. The influence of workload is pretty dominant against the performance of human resources and may cause negative effects to the safety and health of the labours. This study aims to measure the effect of the work climate and the workload against workers productivity. Furthermore, some suggestions to increase the productivity also been recommended. The research conducted in production room of Batik Merak Manis Laweyan. The results showed that the workplace climate and the workload at eight stations in production room of Merak Manis does not agree to the threshold limit value that has been set. Therefore, it is recommended to add more opening windows to add air velocity inside the building thus the humidity and temperature might be reduced.

Community phylogenetics at the biogeographical scale: cold tolerance, niche conservatism and the structure of North American forests.

PubMed

Hawkins, Bradford A; Rueda, Marta; Rangel, Thiago F; Field, Richard; Diniz-Filho, José Alexandre F; Linder, Peter

2014-01-01

Aim The fossil record has led to a historical explanation for forest diversity gradients within the cool parts of the Northern Hemisphere, founded on a limited ability of woody angiosperm clades to adapt to mid-Tertiary cooling. We tested four predictions of how this should be manifested in the phylogenetic structure of 91,340 communities: (1) forests to the north should comprise species from younger clades (families) than forests to the south; (2) average cold tolerance at a local site should be associated with the mean family age (MFA) of species; (3) minimum temperature should account for MFA better than alternative environmental variables; and (4) traits associated with survival in cold climates should evolve under a niche conservatism constraint. Location The contiguous United States. Methods We extracted angiosperms from the US Forest Service's Forest Inventory and Analysis database. MFA was calculated by assigning age of the family to which each species belongs and averaging across the species in each community. We developed a phylogeny to identify phylogenetic signal in five traits: realized cold tolerance, seed size, seed dispersal mode, leaf phenology and height. Phylogenetic signal representation curves and phylogenetic generalized least squares were used to compare patterns of trait evolution against Brownian motion. Eleven predictors structured at broad or local scales were generated to explore relationships between environment and MFA using random forest and general linear models. Results Consistent with predictions, (1) southern communities comprise angiosperm species from older families than northern communities, (2) cold tolerance is the trait most strongly associated with local MFA, (3) minimum temperature in the coldest month is the environmental variable that best describes MFA, broad-scale variables being much stronger correlates than local-scale variables, and (4) the phylogenetic structures of cold tolerance and at least one other trait associated with survivorship in cold climates indicate niche conservatism. Main conclusions Tropical niche conservatism in the face of long-term climate change, probably initiated in the Late Cretaceous associated with the rise of the Rocky Mountains, is a strong driver of the phylogenetic structure of the angiosperm component of forest communities across the USA. However, local deterministic and/or stochastic processes account for perhaps a quarter of the variation in the MFA of local communities.

Small mammal taxonomy, taphonomy, and the paleoenvironmental record during the Middle and Upper Paleolithic at Geißenklösterle Cave (Ach Valley, southwestern Germany)

NASA Astrophysics Data System (ADS)

Rhodes, Sara E.; Ziegler, Reinhard; Starkovich, Britt M.; Conard, Nicholas J.

2018-04-01

Geißenklösterle Cave, located in the Ach Valley of the Swabian Alb and one of six Swabian cave sites recently named as a UNESCO World Heritage site, has a long history of archaeological research resulting in a detailed record of human occupation. Sometime around 45,000 years ago Neanderthals seemingly vanished from the Swabian landscape, and after a period of mostly geogenic deposit at Geißenklösterle Cave we find deposits containing characteristically Aurignacian artifacts dating to as early as 42,500 years ago. These Aurignacian groups brought with them complex symbolic expression and communication including bone and ivory beads, musical instruments, and animal and human figurines. This study examines the climatic context of this depopulation through a taxonomic and taphonomic analysis of the rodent and insectivore remains associated with these periods and provides a relatively unbiased climatic record for the period of ∼45,000-36,000 years ago in this region. Taphonomic analysis indicates that primarily the European eagle owl (Bubo bubo) and the kestrel (Falco tinnunculus) were responsible for accumulating the material, and allows us to quantify the potential taxonomic bias resulting from predator behaviour which includes a preference for voles, particularly the water vole (Arvicola terrestris). Additionally, rare taxa (which include species of murids and soricids) may have been present in greater quantities than our sample implies. The assemblage from Geißenklösterle Cave is dominated by the field and common vole (Microtus arvalis/agrestis), the narrow-headed vole (Microtus gregalis), and the root/tundra vole (Microtus oeconomus). Overall, the Middle Paleolithic landscape included significant woodland and forested areas while a high proportion of species restricted to cold tundra environments likely indicate punctuated cold and arid periods. The signal from the nearly geogenic layer overlying the Middle Paleolithic material includes a moderate shift in the proportion of cold tundra adapted species, suggesting that the tundra expanded leading up to the Neanderthal depopulation, but no period of drastic climatic change is recognizable. The Aurignacian was significantly colder and drier than the preceding period, with cold tundra expansion reaching its apex (for the time period studied). Based on these results the Swabian landscape first encountered by Aurignacian groups was significantly less hospitable than that known to the earlier Middle Paleolithic populations. These results correlate well with past paleoenvironmental reconstructions based on sedimentary, botanical, and faunal assemblages. There is no evidence in the small mammal record that climatic pressure drove Neanderthals from the Ach Valley, instead it seems likely they enjoyed a more temperate environment than later Aurignacian groups. Ongoing work focused on greater resolution of these climatic oscillations at similarly well-dated Swabian sites will shed further light on the timing and speed of this climatic shift and the response of the biological communities affected, including early human groups.

Is "Warm Arctic, Cold Continent" A Fingerprint Pattern of Climate Change?

NASA Astrophysics Data System (ADS)

Hoerling, M. P.; Sun, L.; Perlwitz, J.

2015-12-01

Cold winters and cold waves have recently occurred in Europe, central Asia and the Midwest to eastern United States, even as global mean temperatures set record highs and Arctic amplification of surface warming continued. Since 1979, Central Asia winter temperatures have in fact declined. Conjecture has it that more cold extremes over the mid-latitude continents should occur due to global warming and the impacts of Arctic sea ice loss. A Northern Hemisphere temperature signal termed the "Warm Arctic, Cold Continent" pattern has thus been surmised. Here we use a multi-model approach to test the hypothesis that such a pattern is indeed symptomatic of climate change. Diagnosis of a large model ensemble of historical climate simulations shows some individual realizations to yield cooling trends over Central Asia, but importantly the vast majority show warming. The observed cooling has thus likely been a low probability state of internal variability, not a fingerprint of forced climate change. We show that daily temperature variations over continents decline in winter due to global warming, and cold waves become less likely. This is partly related to diminution of Arctic cold air reservoirs due to warming-induced sea ice loss. Nonetheless, we find some evidence and present a physical basis that Arctic sea ice loss alone can induce a winter cooling over Central Asia, though with a magnitude that is appreciably smaller than the overall radiative-forced warming signal. Our results support the argument that recent cooling trends over central Asia, and cold extreme events over the winter continents, have principally resulted from atmospheric internal variability and have been neither a forced response to Arctic seas ice loss nor a symptom of global warming. The paradigm of climate change is thus better expressed as "Warm Arctic, Warm Continent" for the NH winter.

Climate change and temperature extremes: A review of heat- and cold-related morbidity and mortality concerns of municipalities.

PubMed

Gronlund, Carina J; Sullivan, Kyle P; Kefelegn, Yonathan; Cameron, Lorraine; O'Neill, Marie S

2018-08-01

Cold and hot weather are associated with mortality and morbidity. Although the burden of temperature-associated mortality may shift towards high temperatures in the future, cold temperatures may represent a greater current-day problem in temperate cities. Hot and cold temperature vulnerabilities may coincide across several personal and neighborhood characteristics, suggesting opportunities for increasing present and future resilience to extreme temperatures. We present a narrative literature review encompassing the epidemiology of cold- and heat-related mortality and morbidity, related physiologic and environmental mechanisms, and municipal responses to hot and cold weather, illustrated by Detroit, Michigan, USA, a financially burdened city in an economically diverse metropolitan area. The Detroit area experiences sharp increases in mortality and hospitalizations with extreme heat, while cold temperatures are associated with more gradual increases in mortality, with no clear threshold. Interventions such as heating and cooling centers may reduce but not eliminate temperature-associated health problems. Furthermore, direct hemodynamic responses to cold, sudden exertion, poor indoor air quality and respiratory epidemics likely contribute to cold-related mortality. Short- and long-term interventions to enhance energy and housing security and housing quality may reduce temperature-related health problems. Extreme temperatures can increase morbidity and mortality in municipalities like Detroit that experience both extreme heat and prolonged cold seasons amidst large socioeconomic disparities. The similarities in physiologic and built-environment vulnerabilities to both hot and cold weather suggest prioritization of strategies that address both present-day cold and near-future heat concerns. Copyright © 2018. Published by Elsevier B.V.

Effects of rain on energy metabolism while running in a cold environment.

PubMed

Ito, R; Nakano, M; Yamane, M; Amano, M; Matsumoto, T

2013-08-01

Environmental factors tend to influence the performance of individuals who exercise for extended periods. The present study aimed to determine energy metabolism while running in cold, wet conditions using a climatic chamber that can precisely simulate rainy conditions. 7 healthy men (age, 23.3±2.9 (SD) y; height, 168.6±7.5 cm; weight, 65.9±8.1 kg; V. O2max, 52.0±5.7 mL·kg - 1·min - 1) ran on a treadmill at 70% ˙VO2max intensity for 30 min in a climatic chamber at an ambient temperature of 5°C in the presence (RAIN) or absence (CON) of 40 mm/h of precipitation. Expired air, esophageal temperature, heart rate, mean skin temperature, rating of perceived exertion and blood samples were measured. Esophageal temperature and mean skin temperature were significantly lower (P<0.05) in RAIN than in CON all. Minute ventilation, oxygen consumption and levels of plasma lactate and norepinephrine were significantly higher (P<0.05) in RAIN than in CON. In conclusion, the higher oxygen consumption and plasma lactate in RAIN indicated that energy demand increases when running in cold conditions. © Georg Thieme Verlag KG Stuttgart · New York.

Evaluation of simulated corn yields and associated uncertainty in different climate zones of China using Daycent Model

NASA Astrophysics Data System (ADS)

Fu, A.; Xue, Y.

2017-12-01

Corn is one of most important agricultural production in China. Research on the simulation of corn yields and the impacts of climate change and agricultural management practices on corn yields is important in maintaining the stable corn production. After climatic data including daily temperature, precipitation, solar radiation, relative humidity, and wind speed from 1948 to 2010, soil properties, observed corn yields, and farmland management information were collected, corn yields grown in humidity and hot environment (Sichuang province) and cold and dry environment (Hebei province) in China in the past 63 years were simulated by Daycent, and the results was evaluated based on published yield record. The relationship between regional climate change, global warming and corn yield were analyzed, the uncertainties of simulation derived from agricultural management practices by changing fertilization levels, land fertilizer maintenance and tillage methods were reported. The results showed that: (1) Daycent model is capable to simulate corn yields under the different climatic background in China. (2) When studying the relationship between regional climate change and corn yields, it has been found that observed and simulated corn yields increased along with total regional climate change. (3) When studying the relationship between the global warming and corn yields, It was discovered that newly-simulated corn yields after removing the global warming trend of original temperature data were lower than before.

Preventing cold-related morbidity and mortality in a changing climate

PubMed Central

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

2011-01-01

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

Natural environment and thermal behaviour of Dimetrodon limbatus.

PubMed

Florides; Kalogirou; Tassou; Wrobel

2001-02-01

This paper examines the body temperature variation of Dimetrodon during the different seasons of the year. The effect of the sail of Dimetrodon on its body temperature is also evaluated. It is shown that the sail of pelycosaurs provided an advantage to the reptile by warming it up quicker in the morning in cold environments. This would be a benefit, allowing Dimetrodon to prey on large reptiles, above 55kg, in the early morning while they were sluggish. From the results presented a climate similar to that of March for Cyprus could be representative of that of Permian period.

Calcareous nannoplankton and foraminiferal response to global Oligocene and Miocene climatic oscillations: a case study from the Western Carpathian segment of the Central Paratethys

NASA Astrophysics Data System (ADS)

Holcová, Katarína

2017-06-01

The reactions of foraminiferal and calcareous nannoplankton assemblages to global warming and cooling events in the time intervals of ca. 27 to 19 Ma and 13.5 to 15 Ma (Oligocene and Miocene) were studied in subtropical epicontinental seas influenced by local tectonic and palaeogeographic events (the Central Paratethys). Regardless of these local events, global climatic processes significantly influenced the palaeoenvironment within the marine basin. Warm intervals are characterized by a stable, humid climate and a high-nutrient regime, due primarily to increased continental input of phytodetritus and also locally due to seasonal upwelling. Coarse clastics deposited in a hyposaline environment characterize the marginal part of the basin. Aridification events causing decreased riverine input and consequent nutrient decreases, characterized cold intervals. Apparent seasonality, as well as catastrophic climatic events, induced stress conditions and the expansion of opportunistic taxa. Carbonate production and hypersaline facies characterize the marginal part of the basins. Hypersaline surface water triggered downwelling circulation and mixing of water masses. Decreased abundance or extinction of K-specialists during each cold interval accelerated their speciation in the subsequent warm interval. Local tectonic events led to discordances between local and global sea-level changes (tectonically triggered uplift or subsidence) or to local salt formation (in the rain shadows of newly-created mountains).

Low Elevation Riparian Environments: Warm-Climate Refugia for Conifers in the Great Basin, USA?

NASA Astrophysics Data System (ADS)

Millar, C.; Charlet, D. A.; Westfall, R. D.; Delany, D.

2015-12-01

The Great Basin, USA, contains hundreds of small to large mountain ranges. Many reach alpine elevations, which are separated from each other by low-elevation basins currently inhospitable to conifer growth. Many of these ranges support montane and subalpine conifer species that have affinities to the Sierra Nevada or Rocky Mountains, and from which these conifers migrated during cool periods of the Pleistocene. Under Holocene climates, the Great Basin geography became a terrestrial island-archipelago, wherein conifer populations are isolated among ranges, and inter-range migration is highly limited. During warm intervals of the Holocene, conifers would be expected to have migrated upslope following favorable conditions, and extirpation would be assumed to result from continued warming. Independent patterns, repeating across multiple species' distributions, however, suggest that refugia were present in these ranges during warm periods, and that low elevation environments below the current main distributions acted as climatic refugia. We hypothesize that cool, narrow, and north-aspect ravines, which during cool climates support persistent or seasonal creeks and deciduous riparian communities, become available as conifer habitat when warming climates desiccate creeks and deplete riparian species. We further speculate that cold-air drainage, reduced solar insolation, lower wind exposure, and higher water tables in these topographic positions support populations of montane and subalpine conifers even during warm climate intervals when high elevations are unfavorable for conifer persistence. On return to cool climates, low elevation refugia become sources for recolonizing higher slopes, and/or continue to persist as relictual populations. We present several lines of evidence supporting this hypothesis, and speculate that low-elevation, extramarginal riparian environments might act as climate refugia for Great Basin conifers in the future as well.

Observational Simulation of Icing in Extreme Weather Conditions

NASA Astrophysics Data System (ADS)

Gultepe, Ismail; Heymsfield, Andrew; Agelin-Chaab, Martin; Komar, John; Elfstrom, Garry; Baumgardner, Darrel

2017-04-01

Observations and prediction of icing in extreme weather conditions are important for aviation, transportation, and shipping applications, and icing adversely affects the economy. Icing environments can be studied either in the outdoor atmosphere or in the laboratory. There have been several aircraft based in-situ studies related to weather conditions affecting aviation operations, transportation, and marine shipping that includes icing, wind, and turbulence. However, studying severe weather conditions from aircraft observations are limited due to safety and sampling issues, instrumental uncertainties, and even the possibility of aircraft producing its own physical and dynamical effects. Remote sensing based techniques (e.g. retrieval techniques) for studying severe weather conditions represent usually a volume that cannot characterize the important scales and also represents indirect observations. Therefore, laboratory simulations of atmospheric processes can help us better understand the interactions among microphysical and dynamical processes. The Climatic Wind Tunnel (CWT) in ACE at the University of Ontario Institute of Technology (UOIT) has a large semi-open jet test chamber with flow area 7-13 m2 that can precisely control temperatures down to -40°C, and up to 250 km hr-1 wind speeds, for heavy or dry snow conditions with low visibility, similar to ones observed in the Arctic and cold climate regions, or at high altitude aeronautical conditions. In this study, the ACE CWT employed a spray nozzle array suspended in its settling chamber and fed by pressurized water, creating various particle sizes from a few microns up to mm size range. This array, together with cold temperature and high wind speed, enabled simulation of severe weather conditions, including icing, visibility, strong wind and turbulence, ice fog and frost, freezing fog, heavy snow and blizzard conditions. In this study, the test results will be summarized, and their application to aircraft icing will be provided in detail. Overall, based on these results, scientific challenges related to icing environments will be emphasized for Arctic and cold environments in future projects in the ACE CWT.

Multiple cold resistance loci confer the high cold tolerance adaptation of Dongxiang wild rice (Oryza rufipogon) to its high-latitude habitat.

PubMed

Mao, Donghai; Yu, Li; Chen, Dazhou; Li, Lanying; Zhu, Yuxing; Xiao, Yeqing; Zhang, Dechun; Chen, Caiyan

2015-07-01

Dongxiang wild rice is phylogenetically close to temperate japonica and contains multiple cold resistance loci conferring its adaptation to high-latitude habitat. Understanding the nature of adaptation in wild populations will benefit crop breeding in the development of climate-resilient crop varieties. Dongxiang wild rice (DXWR), the northernmost common wild rice known, possesses a high degree of cold tolerance and can survive overwintering in its native habitat. However, to date, it is still unclear how DXWR evolved to cope with low-temperature environment, resulting in limited application of DXWR in rice breeding programs. In this study, we carried out both QTL mapping and phylogenetic analysis to discern the genetic mechanism underlying the strong cold resistance. Through a combination of interval mapping and single locus analysis in two genetic populations, at least 13 QTLs for seedling cold tolerance were identified in DXWR. A phylogenetic study using both genome-wide InDel markers and markers associated with cold tolerance loci reveals that DXWR belongs to the Or-III group, which is most closely related to cold-tolerant Japonica rice rather than to the Indica cultivars that are predominant in the habitat where DXWR grows. Our study paves the way toward an understanding of the nature of adaptation to a northern habitat in O. rufipogon. The QTLs identified in DXWR in this study will be useful for molecular breeding of cold-tolerant rice.

Controls and variability of solute and sedimentary fluxes in Antarctic and sub-Antarctic Environments

NASA Astrophysics Data System (ADS)

Zwolinski, Zbigniew

2015-04-01

The currently prepared SEDIBUD Book on "Source-to-Sink Fluxes in Undisturbed Cold Environments" (edited by Achim A. Beylich, John C. Dixon and Zbigniew Zwolinski and published by Cambridge University Press) is summarizing and synthesizing the achievements of the International Association of Geomorphologists` (I.A.G./A.I.G.) Working Group SEDIBUD (Sediment Budgets in Cold Environments), which has been active since 2005 (http://www.geomorph.org/wg/wgsb.html). The book comprises five parts. One of them is part about sub-Antarctic and Antarctic Environments. This part "Sub-Antarctic and Antarctic Environments" describes two different environments, namely oceanic and continental ones. Each part contains results of research on environmental drivers and rates of contemporary solute and sedimentary fluxes in selected sites. Apart from describing the environmental conditions of the whole continent of Antarctica and sub-Antarctic islands (Zb.Zwolinski, M.Kejna, A.N.Lastochkin, A.Zhirov, S.Boltramovich) this part of the book characterizes terrestrial polar oases free from multi-year ice and snow covers (Zb.Zwolinski). The detailed results of geoecological and sedimentological research come from different parts of Antarctica. Antarctic continental shelf (E.Isla) is an example of sub-Antarctic oceanic environment. South Shetlands, especially King George Island (Zb.Zwolinski, M.Kejna, G.Rachlewicz, I.Sobota, J.Szpikowski), is an example of sub-Antarctic terrestrial environment. Antarctic Peninsula (G.Vieira, M.Francelino, J.C.Fernandes) and surroundings of McMurdo Dry Valleys (W.B.Lyons, K.A.Welch, J.Levy, A.Fountain, D.McKnight) are examples of Antarctic continental environments. The key goals of the Antarctic and sub-Antarctic book chapters are following: (i) identify the main environmental drivers and rates of contemporary solute and sedimentary fluxes, and (ii) model possible effects of projected climate change on solute and sedimentary fluxes in cold climate environments. Solute and sediment transport in the streams of analyzed environments are constrained by the relatively short water runoff season that typically lasts from a few weeks to maximum of four months during the austral summer, for Antarctic and sub-Antarctic regions respectively. Because of high intensity of mechanical and chemical weathering processes solute and sediment transport are rather high within Antarctic environments. Weathering rates on slopes and magnitude of fluvial transport in relatively short streams control the intensity of denudational processes. Both mechanical and chemical denudation varies highly through sub-Antarctic and Antarctic environments. To generate accurate predictions of fluvial and denudational processes we must fully understand the actual geoecological processes, which in some places are under rapid change, e.g., the Antarctic Peninsula and sub-Antarctic islands.

Climatic variability and plant food distribution in Pleistocene Europe: Implications for Neanderthal diet and subsistence

NASA Astrophysics Data System (ADS)

Hardy, Bruce L.

2010-03-01

Contrary to their cold-adapted image, Neanderthals inhabited Pleistocene Europe during a time of great climatic fluctuation with temperatures ranging from as warm as present-day during the last interglacial to as cold as those of the last glacial maximum. Cold-adapted Neanderthals are similarly most often associated with the exploitation of large mammals who are themselves cold-adapted (mammoth, bison, reindeer, etc.). Cold, high-latitude environments are typically seen as lacking in plants generally and in plant foods in particular. Plant foods are therefore usually ignored and Neanderthals are increasingly being viewed as top carnivores who derived the vast majority of their diet from meat. Support for this hypothesis comes largely from stable isotope analysis which tracks only the protein portion of the diet. Diets high in lean meat largely fulfill micronutrient needs but can pose a problem at the macronutrient level. Lean meat can compose no more than 35% of dietary energy before a protein ceiling is reached. Exceeding the protein ceiling can have detrimental physiological effects on the individual. Neanderthals would have needed energy from alternative sources, particularly when animals are fat-depleted and lean meat intake is high. Underground storage organs (USOs) of plants offer one such source, concentrating carbohydrates and energy. USOs could also provide an important seasonal energy source since they are at their maximum energy storage in late fall/winter. Although Paleolithic sites are increasingly yielding plant remains, their presence is rare and they are often given only passing mention in Neanderthal dietary reconstructions. The complexity and number of potential wild plant foods, however, defies easy discussion. Native European wild edible plants with starchy USOs would have been potentially available throughout the Neanderthal range, even during the coldest periods of the Late Pleistocene.

Use of intraspecific variation in thermal responses for estimating an elevational cline in the timing of cold hardening in a sub-boreal conifer.

PubMed

Ishizuka, W; Ono, K; Hara, T; Goto, S

2015-01-01

To avoid winter frost damage, evergreen coniferous species develop cold hardiness with suitable phenology for the local climate regime. Along the elevational gradient, a genetic cline in autumn phenology is often recognised among coniferous populations, but further quantification of evolutionary adaptation related to the local environment and its responsible signals generating the phenological variation are poorly understood. We evaluated the timing of cold hardening among populations of Abies sachalinensis, based on time series freezing tests using trees derived from four seed source populations × three planting sites. Furthermore, we constructed a model to estimate the development of hardening from field temperatures and the intraspecific variations occurring during this process. An elevational cline was detected such that high-elevation populations developed cold hardiness earlier than low-elevation populations, representing significant genetic control. Because development occurred earlier at high-elevation planting sites, the genetic trend across elevation overlapped with the environmental trend. Based on the trade-off between later hardening to lengthen the active growth period and earlier hardening to avoid frost damage, this genetic cline would be adaptive to the local climate. Our modelling approach estimated intraspecific variation in two model components: the threshold temperature, which was the criterion for determining whether the trees accumulated the thermal value, and the chilling requirement for trees to achieve adequate cold hardiness. A higher threshold temperature and a lower chilling requirement could be responsible for the earlier phenology of the high-elevation population. These thermal responses may be one of the important factors driving the elevation-dependent adaptation of A. sachalinensis. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

DEVELOPMENT OF COLD CLIMATE HEAT PUMP USING TWO-STAGE COMPRESSION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shen, Bo; Rice, C Keith; Abdelaziz, Omar

2015-01-01

This paper uses a well-regarded, hardware based heat pump system model to investigate a two-stage economizing cycle for cold climate heat pump applications. The two-stage compression cycle has two variable-speed compressors. The high stage compressor was modelled using a compressor map, and the low stage compressor was experimentally studied using calorimeter testing. A single-stage heat pump system was modelled as the baseline. The system performance predictions are compared between the two-stage and single-stage systems. Special considerations for designing a cold climate heat pump are addressed at both the system and component levels.

Estimating and projecting the effect of cold waves on mortality in 209 US cities.

PubMed

Wang, Yan; Shi, Liuhua; Zanobetti, Antonella; Schwartz, Joel D

2016-09-01

The frequency, duration, and intensity of cold waves are expected to decrease in the near future under the changing climate. However, there is a lack of understanding on future mortality related to cold waves. The present study conducted a large-scale national projection to estimate future mortality attributable to cold waves during 1960-2050 in 209 US cities. Cold waves were defined as two, three, or at least four consecutive days with daily temperature lower than the 5th percentile of temperatures in each city. The lingering period of a cold wave was defined as the non-cold wave days within seven days following that cold wave period. First, with 168million residents in 209 US cities during 1962-2006, we fitted over-dispersed Poisson regressions to estimate the immediate and lingering effects of cold waves on mortality and tested if the associations were modified by the duration of cold waves, the intensity of cold waves, and mean winter temperature (MWT). Then we projected future mortality related to cold waves using 20 downscaled climate models. Here we show that the cold waves (both immediate and lingering) were associated with an increased but small risk of mortality. The associations varied substantially across climate regions. The risk increased with the duration and intensity of cold waves but decreased with MWT. The projected mortality related to cold waves would decrease from 1960 to 2050. Such a decrease, however, is small and may not be able to offset the potential increase in heat-related deaths if the adaptation to heat is not adequate. Copyright © 2016 Elsevier Ltd. All rights reserved.

Influence of sky view factor on outdoor thermal environment and physiological equivalent temperature

NASA Astrophysics Data System (ADS)

He, Xiaodong; Miao, Shiguang; Shen, Shuanghe; Li, Ju; Zhang, Benzhi; Zhang, Ziyue; Chen, Xiujie

2015-03-01

Sky view factor (SVF), which is an indicator of urban canyon geometry, affects the surface energy balance, local air circulation, and outdoor thermal comfort. This study focused on a continuous and long-term meteorological observation system to investigate the effects of SVF on outdoor thermal conditions and physiological equivalent temperature (PET) in the central business district (CBD) of Beijing (which is located within Chaoyang District), specifically addressed current knowledge gaps for SVF-PET relationships in cities with typical continental/microthermal climates. An urban sub-domain scale model and the RayMan model were used to diagnose wind fields and to calculate SVF and long-term PET, respectively. Analytical results show that the extent of shading contributes to variations in thermal perception distribution. Highly shaded areas (SVF <0.3) typically exhibit less frequent hot conditions during summer, while enduring longer periods of cold discomfort in winter than moderately shaded areas (0.3< SVF <0.5) and slightly shaded areas (SVF >0.5), and vice versa. Because Beijing has a monsoon-influenced humid continental climate with hot summers and long, cold, windy, and dry winters, a design project that ideally provides moderate shading should be planned to balance hot discomfort in summer and cold discomfort in winter, which effectively prolongs the comfort periods in outdoor spaces throughout the entire year. This research indicate that climate zone characteristics, urban environmental conditions, and thermal comfort requirements of residents must be accounted for in local-scale scientific planning and design, i.e., for urban canyon streets and residential estates.

Controls of sediment transfers, sedimentary budgets and relief development in cold environments: Results from four catchment systems in Iceland, Swedish Lapland and Finnish Lapland

NASA Astrophysics Data System (ADS)

Beylich, A. A.

2012-04-01

By the combined, longer-term and quantitative recording of relevant denudative slope processes and stream work in four selected catchment systems in sub-arctic oceanic Eastern Iceland (Hrafndalur and Austdalur), arctic-oceanic Swedish Lapland (Latnjavagge) and sub-arctic oceanic Finnish Lapland (Kidisjoki), information on the absolute and relative importance of the different denudative processes is collected. Direct comparison of the four catchment geo-systems (the catchment sizes range from 7 km2 to 23 km2) allows conclusions on major controls of sediment transfers, sedimentary budgets and relief development in theses cold climate environments. To allow direct comparison of the different processes, all mass transfers are calculated as tonnes multiplied by meter per year, i.e. as the product of the annually transferred mass and the corresponding transport distance. Ranking the different processes according to their annual mass transfers shows that stream work dominates over slope denudation. For Hrafndalur (Eastern Iceland) the following order of denudative processes is found after nine years of process studies (2001 - 2010): (1) Fluvial suspended sediment plus bedload transport, (2) Fluvial solute transport, (3) Rock falls plus boulder falls, (4) Chemical slope denudation, (5) Mechanical fluvial slope denudation (slope wash), (6) Creep processes, (7) Avalanches, (8) Debris flows, (9) Translation slides, (10) Deflation. Compared to that, in Austdalur the following ranking is given after fourten years of process studies (1996 - 2010): (1) Fluvial suspended sediment plus bedload transport, (2) Fluvial solute transport, (3) Mechanical fluvial slope denudation (slope wash), (4) Chemical slope denudation, (5) Avalanches, (6) Rock falls plus boulder falls, (7) Creep processes, (8) Debris flows, (9) Deflation, (10) Translation slides. In the Latnjavagge catchment (Swedish Lapland) the ranking is (eleven-years period of studies, 1999 - 2010): (1) Fluvial solute transport, (2) Fluvial suspended sediment plus bedload transport, (3) Rock falls plus boulder falls, (4) Chemical slope denudation, (5) Mechanical fluvial slope denudation (slope wash), (6) Avalanches, (7) Creep processes and solifluction, (8) Slush flows, (9) Debris flows, (10) Translation slides, (11) Deflation. In Kidisjoki (Finnish Lapland) the order of processes, as determined after a nine-years period (2001 - 2010) of geomorphic process studies, is: (1) Fluvial solute transport, (2) Chemical slope denudation, (3) Fluvial suspended sediment plus bedload transport, (4) Mechanical fluvial slope denudation, (5) Creep processes, (6) Avalanches and slush flows, (7) Debris flows and slides, (8) Rock and boulder falls, (9) Deflation. As a result, in all four selected cold climate study areas the intensity of contemporary denudative processes and mass transfers is altogether rather low, which is in opposition to the earlier postulated oppinion of a generally high intensity of geomorphic processes in cold climate environments. A direct comparison of the annual mass transfers summarises that there are differences between process intensities and the relative importance of different denudative processes within the four study areas. The major controls of these detected differences are: (i) Climate: The higher annual precipitation along with the larger number of extreme rainfall events and the higher frequency of snowmelt and rainfall generated peak runoff events in Eastern Iceland as compared to Swedish Lapland and Finnish Lapland lead to higher mass transfers, (ii) Lithology: The low resistance of rhyolites in Hrafndalur causes especially high weathering rates and connected mass transfers in this catchment. Due to the lower resistance of the rhyolites as compared to the basalts found in Austdalur Postglacial modification of the glacially formed relief is clearly further advanced in Hrafndalur as compared to Austdalur, (iii) Relief: The greater steepness of the Icelandic catchments leads to higher mass transfers here as compared to Latnjavagge and Kidisjoki, (iv) Vegetation cover: The significant disturbance of the vegetation cover by human impacts in Easter Iceland causes higher mass transfers (slope wash) whereas restricted sediment availability is a main reason for lower mass transfers in Swedish Lapland and Finnish Lapland. The applied catchment-based approach seems to be effective for analysing sediment budgets and trends of Postglacial relief development in selected study areas with given environmental settings. Direct comparison of investigated catchments will improve possibilities to model relief development as well as possible effects of projected climate change in cold climate environments.

Combined ocean acidification and low temperature stressors cause coral mortality

NASA Astrophysics Data System (ADS)

Kavousi, Javid; Parkinson, John Everett; Nakamura, Takashi

2016-09-01

Oceans are predicted to become more acidic and experience more temperature variability—both hot and cold—as climate changes. Ocean acidification negatively impacts reef-building corals, especially when interacting with other stressors such as elevated temperature. However, the effects of combined acidification and low temperature stress have yet to be assessed. Here, we exposed nubbins of the scleractinian coral Montipora digitata to ecologically relevant acidic, cold, or combined stress for 2 weeks. Coral nubbins exhibited 100% survival in isolated acidic and cold treatments, but ~30% mortality under combined conditions. These results provide further evidence that coupled stressors have an interactive effect on coral physiology, and reveal that corals in colder environments are also susceptible to the deleterious impacts of coupled ocean acidification and thermal stress.

The 1430s: a cold period of extraordinary internal climate variability during the early Spörer Minimum with social and economic impacts in north-western and central Europe

NASA Astrophysics Data System (ADS)

Camenisch, Chantal; Keller, Kathrin M.; Salvisberg, Melanie; Amann, Benjamin; Bauch, Martin; Blumer, Sandro; Brázdil, Rudolf; Brönnimann, Stefan; Büntgen, Ulf; Campbell, Bruce M. S.; Fernández-Donado, Laura; Fleitmann, Dominik; Glaser, Rüdiger; González-Rouco, Fidel; Grosjean, Martin; Hoffmann, Richard C.; Huhtamaa, Heli; Joos, Fortunat; Kiss, Andrea; Kotyza, Oldřich; Lehner, Flavio; Luterbacher, Jürg; Maughan, Nicolas; Neukom, Raphael; Novy, Theresa; Pribyl, Kathleen; Raible, Christoph C.; Riemann, Dirk; Schuh, Maximilian; Slavin, Philip; Werner, Johannes P.; Wetter, Oliver

2016-12-01

Changes in climate affected human societies throughout the last millennium. While European cold periods in the 17th and 18th century have been assessed in detail, earlier cold periods received much less attention due to sparse information available. New evidence from proxy archives, historical documentary sources and climate model simulations permit us to provide an interdisciplinary, systematic assessment of an exceptionally cold period in the 15th century. Our assessment includes the role of internal, unforced climate variability and external forcing in shaping extreme climatic conditions and the impacts on and responses of the medieval society in north-western and central Europe.Climate reconstructions from a multitude of natural and anthropogenic archives indicate that the 1430s were the coldest decade in north-western and central Europe in the 15th century. This decade is characterised by cold winters and average to warm summers resulting in a strong seasonal cycle in temperature. Results from comprehensive climate models indicate consistently that these conditions occurred by chance due to the partly chaotic internal variability within the climate system. External forcing like volcanic eruptions tends to reduce simulated temperature seasonality and cannot explain the reconstructions. The strong seasonal cycle in temperature reduced food production and led to increasing food prices, a subsistence crisis and a famine in parts of Europe. Societies were not prepared to cope with failing markets and interrupted trade routes. In response to the crisis, authorities implemented numerous measures of supply policy and adaptation such as the installation of grain storage capacities to be prepared for future food production shortfalls.

Durability and smart condition assessment of ultra-high performance concrete in cold climates.

DOT National Transportation Integrated Search

2016-12-31

The goals of this study were to develop ecological ultra-high performance concrete (UHPC) with local materials and supplementary cementitious materials and to evaluate the long-term performance of UHPC in cold climates using effective mechanical test...

Optimization of Photosynthetic Productivity in Contrasting Environments by Regulons Controlling Plant Form and Function

PubMed Central

Demmig-Adams, Barbara; Baker, Christopher R.

2018-01-01

We review the role of a family of transcription factors and their regulons in maintaining high photosynthetic performance across a range of challenging environments with a focus on extreme temperatures and water availability. Specifically, these transcription factors include CBFs (C-repeat binding factors) and DREBs (dehydration-responsive element-binding), with CBF/DREB1 primarily orchestrating cold adaptation and other DREBs serving in heat, drought, and salinity adaptation. The central role of these modulators in plant performance under challenging environments is based on (i) interweaving of these regulators with other key signaling networks (plant hormones and redox signals) as well as (ii) their function in integrating responses across the whole plant, from light-harvesting and sugar-production in the leaf to foliar sugar export and water import and on to the plant’s sugar-consuming sinks (growth, storage, and reproduction). The example of Arabidopsis thaliana ecotypes from geographic origins with contrasting climates is used to describe the links between natural genetic variation in CBF transcription factors and the differential acclimation of plant anatomical and functional features needed to support superior photosynthetic performance in contrasting environments. Emphasis is placed on considering different temperature environments (hot versus cold) and light environments (limiting versus high light), on trade-offs between adaptations to contrasting environments, and on plant lines minimizing such trade-offs. PMID:29543762

[Effect of climatic mean value change on the evaluation result of rice delayed cold damage in Liaoning Province, Northeast China].

PubMed

Ji, Rui-peng; Yu, Wen-ying; Wu, Jin-wen; Feng, Rui; Zhang, Yu-shu

2015-06-01

The anomaly of mean temperature summation from May to September (ΔT5-9) was commonly used to assess delayed cold damage of rice in Northeast China, but whether the change of statistics years for climatic mean value (ΣT5-9) would affect the, evaluation results of Liaoning rice under cold damage needed to be further studied. By using the meteorological industry standard of the People's Republic of China "technical standard on rice cold damage evaluation" (QX/T 182- 2013) and the supplemental indices (ΔT5-9), the index (ΣT5-9) was calculated in four periods 1961-1990 (S1), 1971-2000 (S2), 1981-2010 (S3) and 1961-2010 (S4), and the spatial and temporal changes of cold damage in Liaoning Province were analyzed based on the ratio between cold damage stations and total stations (IOC) and the occurrence frequency. The results showed that the heat condition (Σ T5-9) in rice growing season increased obviously and the spatial and temporal changes were significant from 1961 to 2010. The original meteorological index of rice cold damage was improved by using quadratic polynomial model. The identification results were similar between S2 and S4. The variation coefficient of IOC in S3 was lower than that of the other three. Compared with the typical rice yield reduction years, the evaluation results accorded better with the actual situation in evaluating the rice delayed cold damage in Liaoning during study period by using the S3 climate mean value. The results could provide evidence for accurately evaluating the variation of rice cold damage in spatial and temporal distribution in Liaoning Province under the background of global climate change.

Paleoclimatic insights from mapping the global distribution of non-glacial cryogenic landforms in sub-humid montane environments.

NASA Astrophysics Data System (ADS)

Slee, Adrian; Shulmeister, James

2015-04-01

Much of the 'periglacial' literature is based on landforms and observations from either high mountains or continental environments dominated by strong winter cooling and/or permafrost conditions. Cryogenic conditions occur in many other settings and some of the most widespread are montane landscapes in mid- to low latitudes. In Australia observations of 'periglacial' landforms have traditionally been limited to higher elevation regions of the Australian Alps and central Tasmania. However, the distribution of relict cryogenic landforms is much wider and extends well into sub-tropical latitudes along the eastern highlands of Australia. Here we map the distribution of relict block deposits (block streams and block fields) of known cryogenic origin so as to delineate the limits of 'periglacial' climatic conditions during cold phases in the Late Quaternary. The mapping is based on image analyses supported by extensive and intensive ground truthing. Three distinct regimes are recognised - a high elevation winter wet regime (Mt Kosciuszko style); a temperate maritime westerly regime (Tasmania style) and, unexpectedly, an east coast (sub-tropical) regime (New England style). We utilise bio-climatic modelling to derive modern climate parameters from the distribution of the block deposits so as to map regions affected by cryogenic conditions in late Quaternary cold periods. We assumed that relative changes in mean cooling and precipitation would be shared by other mid-latitude climate locales worldwide and predicted the likely distribution of block deposits in these areas. A literature review confirms the presence of 'periglacial' style block deposits in the predicted regions, including part of the Iberian Peninsula, the Atlas and Drakensburg Mountains of Africa, the Mediterranean island of Sardinia, the higher volcanoes of Mexico and parts of China, all of which have mean annual precipitation similar to the New England area. However, we also note that many of these areas have winter wet (Mediterranean) climates and when seasonality of precipitation is included, winter dry New England becomes an anomaly. We conclude that in addition to significant cooling, winter moisture balance was more positive, in northern New South Wales during cooler climate periods.

Transitions between multiple equilibria of paleo climate: a glimpse in to the dynamics of abrupt climate change

NASA Astrophysics Data System (ADS)

Ferreira, David; Marshall, John; Ito, Takamitsu; McGee, David; Moreno-Chamarro, Eduardo

2017-04-01

The dynamics regulating large climatic transitions such as glacial-interglacial cycles or DO events remains a puzzle. Forcings behind these transitions are not robustly identified and potential candidates (e.g. Milankovitch cycles, freshwater perturbations) often appear too weak to explain such dramatic transitions. A potential solution to this long-standing puzzle is that Earth's climate is endowed with multiple equilibrium states of global extent. Such states are commonly found in low-order or conceptual climate models, but it is unclear whether a system as complex as Earth's climate can sustain multiple equilibrium states. Here we report that multiple equilibrium states of the climate system are also possible in a complex, fully dynamical coupled ocean-atmosphere-sea ice GCM with idealized Earth-like geometry, resolved weather systems and a hydrological cycle. In our model, two equilibrium states coexist for the same parameters and external forcings: a Warm climate with a small Northern hemisphere sea ice cap and a large southern one and a Cold climate with large ice caps at both poles. The dynamical states of the Warm and Cold solutions exhibit striking similarities with our present-day climate and the climate of the Last Glacial Maximum, respectively. A carbon cycle model driven by the two dynamical states produces an atmospheric pCO2 draw-down of about 110 pm between the Warm and Cold states, close to Glacial-Interglacial differences found in ice cores. Mechanism controlling the existence of the multiple states and changes in the atmospheric CO2 will be briefly presented. Finally we willdescribe transition experiments from the Cold to the Warm state, focusing on the lead-lags in the system, notably between the Northern and Southern Hemispheres climates.

Forecasting European cold waves based on subsampling strategies of CMIP5 and Euro-CORDEX ensembles

NASA Astrophysics Data System (ADS)

Cordero-Llana, Laura; Braconnot, Pascale; Vautard, Robert; Vrac, Mathieu; Jezequel, Aglae

2016-04-01

Forecasting future extreme events under the present changing climate represents a difficult task. Currently there are a large number of ensembles of simulations for climate projections that take in account different models and scenarios. However, there is a need for reducing the size of the ensemble to make the interpretation of these simulations more manageable for impact studies or climate risk assessment. This can be achieved by developing subsampling strategies to identify a limited number of simulations that best represent the ensemble. In this study, cold waves are chosen to test different approaches for subsampling available simulations. The definition of cold waves depends on the criteria used, but they are generally defined using a minimum temperature threshold, the duration of the cold spell as well as their geographical extend. These climate indicators are not universal, highlighting the difficulty of directly comparing different studies. As part of the of the CLIPC European project, we use daily surface temperature data obtained from CMIP5 outputs as well as Euro-CORDEX simulations to predict future cold waves events in Europe. From these simulations a clustering method is applied to minimise the number of ensembles required. Furthermore, we analyse the different uncertainties that arise from the different model characteristics and definitions of climate indicators. Finally, we will test if the same subsampling strategy can be used for different climate indicators. This will facilitate the use of the subsampling results for a wide number of impact assessment studies.

Teaching in a Cold Environment.

ERIC Educational Resources Information Center

Ewert, Alan

1979-01-01

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

Outdoor human thermal perception in various climates: A comprehensive review of approaches, methods and quantification.

PubMed

Potchter, Oded; Cohen, Pninit; Lin, Tzu-Ping; Matzarakis, Andreas

2018-08-01

Over the past century, many research studies have been conducted in an attempt to define thermal conditions for humans in the outdoor environment and to grade thermal sensation. Consequently, a large number of indices have been proposed. The examination of human thermal indices by thermal subjective perception has become recently a methodical issue to confirm the accuracy, applicability and validation of human thermal indices. The aims of this study are: (a) to review studies containing both calculated human thermal conditions and subjective thermal perception in the outdoor environment (b) to identify the most used human thermal indices for evaluating human thermal perception (c) to examine the relation between human thermal comfort range and outdoor thermal environment conditions and (d) to compare between categories of thermal sensation in different climatic zones based on subjective perception and levels of thermal strain. A comprehensive literature review identified 110 peer-reviewed articles which investigated in-situ thermal conditions versus subjective thermal perception during 2001-2017. It seems that out of 165 human thermal indices that have been developed, only 4 (PET, PMV, UTCI, SET*) are widely in use for outdoor thermal perception studies. Examination of the relation between human thermal comfort range and outdoor thermal environment conditions for selective indices in different climatic zones shows that the range of the thermal comfort or dis-comfort is affected by the outdoor thermal environment. For the PET index, the "neutral" range for hot climates of 24-26°C is agreed by 95% of the studies where for cold climate, the "neutral" range of 15-20°C is agreed by 89% of the studies. For the UTCI, the "no thermal stress" category is common to all climates. The "no stress category" of 16-23°C is agreed by 80% of the case studies, while 100% of the case studies agreed that the range is between 18 and 23°C. Copyright © 2018 Elsevier B.V. All rights reserved.

Insects and low temperatures: from molecular biology to distributions and abundance.

PubMed Central

Bale, J S

2002-01-01

Insects are the most diverse fauna on earth, with different species occupying a range of terrestrial and aquatic habitats from the tropics to the poles. Species inhabiting extreme low-temperature environments must either tolerate or avoid freezing to survive. While much is now known about the synthesis, biochemistry and function of the main groups of cryoprotectants involved in the seasonal processes of acclimatization and winter cold hardiness (ice-nucleating agents, polyols and antifreeze proteins), studies on the structural biology of these compounds have been more limited. The recent discovery of rapid cold-hardening, ice-interface desiccation and the daily resetting of critical thermal thresholds affecting mortality and mobility have emphasized the role of temperature as the most important abiotic factor, acting through physiological processes to determine ecological outcomes. These relationships are seen in key areas such as species responses to climate warming, forecasting systems for pest outbreaks and the establishment potential of alien species in new environments. PMID:12171648

Glacial geomorphic evidence for a late climatic change on Mars

NASA Technical Reports Server (NTRS)

Kargel, J. S.; Strom, R. G.

1992-01-01

In a series of preliminary reports, we documented evidence of former glacial epochs on Mars. Apparent glacial landforms seemed to be concentrated primarily at middle to high southern latitudes. We now have additional evidence supporting the view that Martian glaciation appears to have been more extensive than previously recognized. The growth and collapse of ice sheets on Mars seems closely analogous to the growth and decline of Earth's great Pleistocene ice sheets. This implies that climate change was probably somewhat comparable on the two planets, although in the case of Mars the entire planet seems to have changed rapidly to a cold, dry present-day environment after the collapse of the ice sheets.

Warm summers during the Younger Dryas cold reversal.

PubMed

Schenk, Frederik; Väliranta, Minna; Muschitiello, Francesco; Tarasov, Lev; Heikkilä, Maija; Björck, Svante; Brandefelt, Jenny; Johansson, Arne V; Näslund, Jens-Ove; Wohlfarth, Barbara

2018-04-24

The Younger Dryas (YD) cold reversal interrupts the warming climate of the deglaciation with global climatic impacts. The sudden cooling is typically linked to an abrupt slowdown of the Atlantic Meridional Overturning Circulation (AMOC) in response to meltwater discharges from ice sheets. However, inconsistencies regarding the YD-response of European summer temperatures have cast doubt whether the concept provides a sufficient explanation. Here we present results from a high-resolution global climate simulation together with a new July temperature compilation based on plant indicator species and show that European summers remain warm during the YD. Our climate simulation provides robust physical evidence that atmospheric blocking of cold westerly winds over Fennoscandia is a key mechanism counteracting the cooling impact of an AMOC-slowdown during summer. Despite the persistence of short warm summers, the YD is dominated by a shift to a continental climate with extreme winter to spring cooling and short growing seasons.

British Military freezing cold injuries: a 13-year review.

PubMed

Heil, Kieran M; Oakley, E H N; Wood, A M

2016-12-01

Cold injuries have been a recurrent feature of warfare for millennia and continue to present during British Military operations today. Those affecting the peripheries are divided into freezing cold injury (FCI) and non-FCI. FCI occurs when tissue fluids freeze at around -0.5°C and is commonly referred to as frostnip or frostbite. All FMED7 notes held at the Institute of Naval Medicine's Cold Weather Injury Clinic (CIC) from 2002 to 2014 were searched for the terms 'frostbite' and 'frostnip' and then analysed to identify common themes. In total 245 results were found and from these, 149 patients with a positive FCI diagnosis were identified and formed the cohort of this study. Royal Marines (RM) represented over 50% of patients and Arctic training in Norway accounted for over two thirds of the total cases. The extremities were almost always those areas which were affected by FCI. Further analysis of the RM cases showed the majority of those injured were of the most junior rank (Marine/Private or Lance Corporal). A lack of supporting climatic and activity data meant that it was difficult to draw additional conclusions from the data collected. In future, a greater emphasis should be placed on collection of climatic and additional data when FCIs are diagnosed. These data should be collated at the end of each deployment and published as was regularly done historically. It is hoped that these data could then be used as the starting point for an annual climatic study day, where issues related to FCIs could be discussed in a Tri-Service environment and lessons learned disseminated around all British Forces personnel. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Modeling Shasta Dam operations to regulate temperatures for Chinook salmon under extreme climate and climate change

NASA Astrophysics Data System (ADS)

Dai, A.; Saito, L.; Sapin, J. R.; Rajagopalan, B.; Hanna, R. B.; Kauneckis, D. L.

2014-12-01

Chinook salmon populations have declined significantly after the construction of Shasta Dam on the Sacramento River in 1945 prevented them from spawning in the cold waters upstream. In 1994, the winter-run Chinook were listed under the Endangered Species Act and 3 years later the US Bureau of Reclamation began operating a temperature control device (TCD) on the dam that allows for selective withdrawal for downstream temperature control to promote salmon spawning while also maximizing power generation. However, dam operators are responsible to other interests that depend on the reservoir for water such as agriculture, municipalities, industry, and recreation. An increase in temperatures due to climate change may place additional strain on the ability of dam operations to maintain spawning habitat for salmon downstream of the dam. We examined the capability of Shasta Dam to regulate downstream temperatures under extreme climates and climate change by using stochastically generated streamflow, stream temperature, and weather inputs with a two-dimensional CE-QUAL-W2 model under several operational options. Operation performance was evaluated using degree days and cold pool volume (volume of water below a temperature threshold). Model results indicated that a generalized operations release schedule, in which release elevations varied over the year to match downstream temperature targets, performed best overall in meeting temperature targets while preserving cold pool volume. Releasing all water out the bottom throughout the year tended to meet temperature targets at the expense of depleting the cold pool, and releasing all water out uppermost gates preserved the cold pool, but released water that was too warm during the critical spawning period. With higher air temperatures due to climate change, both degree day and cold pool volume metrics were worse than baseline conditions, which suggests that Chinook salmon may be more negatively affected under climate change.

Avoided climate impacts of urban and rural heat and cold waves over the U.S. using large climate model ensembles for RCP8.5 and RCP4.5

PubMed Central

Anderson, G.B.; Jones, B.; McGinnis, S.A.; Sanderson, B.

2015-01-01

Previous studies examining future changes in heat/cold waves using climate model ensembles have been limited to grid cell-average quantities. Here, we make use of an urban parameterization in the Community Earth System Model (CESM) that represents the urban heat island effect, which can exacerbate extreme heat but may ameliorate extreme cold in urban relative to rural areas. Heat/cold wave characteristics are derived for U.S. regions from a bias-corrected CESM 30-member ensemble for climate outcomes driven by the RCP8.5 forcing scenario and a 15-member ensemble driven by RCP4.5. Significant differences are found between urban and grid cell-average heat/cold wave characteristics. Most notably, urban heat waves for 1981–2005 are more intense than grid cell-average by 2.1°C (southeast) to 4.6°C (southwest), while cold waves are less intense. We assess the avoided climate impacts of urban heat/cold waves in 2061–2080 when following the lower forcing scenario. Urban heat wave days per year increase from 6 in 1981–2005 to up to 92 (southeast) in RCP8.5. Following RCP4.5 reduces heat wave days by about 50%. Large avoided impacts are demonstrated for individual communities; e.g., the longest heat wave for Houston in RCP4.5 is 38 days while in RCP8.5 there is one heat wave per year that is longer than a month with some lasting the entire summer. Heat waves also start later in the season in RCP4.5 (earliest are in early May) than RCP8.5 (mid-April), compared to 1981–2005 (late May). In some communities, cold wave events decrease from 2 per year for 1981–2005 to one-in-five year events in RCP4.5 and one-in-ten year events in RCP8.5. PMID:29520121

A warm or a cold early Earth? New insights from a 3-D climate-carbon model

NASA Astrophysics Data System (ADS)

Charnay, Benjamin; Le Hir, Guillaume; Fluteau, Frédéric; Forget, François; Catling, David C.

2017-09-01

Oxygen isotopes in marine cherts have been used to infer hot oceans during the Archean with temperatures between 60 °C (333 K) and 80 °C (353 K). Such climates are challenging for the early Earth warmed by the faint young Sun. The interpretation of the data has therefore been controversial. 1D climate modeling inferred that such hot climates would require very high levels of CO2 (2-6 bars). Previous carbon cycle modeling concluded that such stable hot climates were impossible and that the carbon cycle should lead to cold climates during the Hadean and the Archean. Here, we revisit the climate and carbon cycle of the early Earth at 3.8 Ga using a 3D climate-carbon model. We find that CO2 partial pressures of around 1 bar could have produced hot climates given a low land fraction and cloud feedback effects. However, such high CO2 partial pressures should not have been stable because of the weathering of terrestrial and oceanic basalts, producing an efficient stabilizing feedback. Moreover, the weathering of impact ejecta during the Late Heavy Bombardment (LHB) would have strongly reduced the CO2 partial pressure leading to cold climates and potentially snowball Earth events after large impacts. Our results therefore favor cold or temperate climates with global mean temperatures between around 8 °C (281 K) and 30 °C (303 K) and with 0.1-0.36 bar of CO2 for the late Hadean and early Archean. Finally, our model suggests that the carbon cycle was efficient for preserving clement conditions on the early Earth without necessarily requiring any other greenhouse gas or warming process.

Germination niche breadth varies inconsistently among three Asclepias congeners along a latitudinal gradient.

PubMed

Finch, Jessamine; Walck, Jeffrey L; Hidayati, Siti N; Kramer, Andrea T; Lason, Victoria; Havens, Kayri

2018-05-20

Species responses to climate change will be primarily driven by their environmental tolerance range, or niche breadth, with the expectation that broad niches will increase resilience. Niche breadth is expected to be greater in more heterogeneous environments and moderated by life history. Niche breadth also varies across life stage. Therefore, the life stage with the narrowest niche may serve as the best predictor of climatic vulnerability. To investigate the relationship between niche breadth, climate, and life stage we identify germination niche breadth for dormant and nondormant seeds in multiple populations of three milkweed (Asclepias) species. Complementary trials evaluated germination under conditions simulating historic and predicted future climate by varying cold-moist stratification temperature, length, and incubation temperature. Germination niche breadth was derived from germination evenness across treatments (Levins B n ), with stratified seeds considered less dormant than non-stratified seeds. Germination response varies significantly among species, populations, and treatments. Cold-moist stratification ≥ 4 weeks (1-3°C) followed by incubation at 25/15°C+ achieves peak germination for most populations. Germination niche breadth significantly expands following stratification and interacts significantly with latitude of origin. Interestingly, two species display a positive relationship between niche breadth and latitude, while the third presents a concave quadratic relationship. Germination niche breadth significantly varies by species, latitude, and population, suggesting an interaction between source climate, life history, and site-specific factors. Results contribute to our understanding of inter- and intraspecific variation in germination, underscore the role of dormancy in germination niche breadth, and have implications for prioritizing and conserving species under climate change. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Thermal perception thresholds among workers in a cold climate.

PubMed

Burström, Lage; Björ, Bodil; Nilsson, Tohr; Pettersson, Hans; Rödin, Ingemar; Wahlström, Jens

2017-10-01

To investigate whether exposure to cold could influence the thermal perception thresholds in a working population. This cross-sectional study was comprised of 251 males and females and was carried out at two mines in the northern part of Norway and Sweden. The testing included a baseline questionnaire, a clinical examination and measurements of thermal perception thresholds, on both hands, the index (Digit 2) and little (Digit 5) fingers, for heat and cold. The thermal perception thresholds were affected by age, gender and test site. The thresholds were impaired by experiences of frostbite in the fingers and the use of medication that potentially could affect neurosensory functions. No differences were found between the calculated normative values for these workers and those in other comparative investigations conducted in warmer climates. The study provided no support for the hypothesis that living and working in cold climate will lead to impaired thermal perception thresholds. Exposure to cold that had caused localized damage in the form of frostbite was shown to lead to impaired thermal perception.

Winter Season Mortality: Will Climate Warming Bring Benefits?

PubMed

Kinney, Patrick L; Schwartz, Joel; Pascal, Mathilde; Petkova, Elisaveta; Tertre, Alain Le; 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.

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.

The Influence of the Green River Lake System on the Local Climate During the Early Eocene Period

NASA Astrophysics Data System (ADS)

Elguindi, N.; Thrasher, B.; Sloan, L. C.

2006-12-01

Several modeling efforts have attempted to reproduce the climate of the early Eocene North America. However when compared to proxy data, General Circulation Models (GCMs) tend to produce a large-scale cold-bias. Although higher resolution Regional Climate Models (RCMs) that are able to resolve many of the sub-GCM scale forcings improve this cold bias, RCMs are still unable to reproduce the warm climate of the Eocene. From geologic data, we know that the greater Green River and the Uinta basins were intermontane basins with a large lake system during portions of the Eocene. We speculate that the lack of presence of these lakes in previous modeling studies may explain part of the persistent cold-bias of GCMs and RCMs. In this study, we utilize a regional climate model coupled with a 1D-lake model in an attempt to reduce the uncertainties and biases associated with climate simulations over Eocene western North American. Specifically, we include the Green River Lake system in our RCM simulation and compare climates with and without lakes to proxy data.

Climate, invasive species and land use drive population dynamics of a cold-water specialist

USGS Publications Warehouse

Kovach, Ryan P.; Al-Chokhachy, Robert K.; Whited, Diane C.; Schmetterling, David A.; Dux, Andrew M; Muhlfeld, Clint C.

2017-01-01

Climate change is an additional stressor in a complex suite of threats facing freshwater biodiversity, particularly for cold-water fishes. Research addressing the consequences of climate change on cold-water fish has generally focused on temperature limits defining spatial distributions, largely ignoring how climatic variation influences population dynamics in the context of other existing stressors.We used long-term data from 92 populations of bull trout Salvelinus confluentus – one of North America's most cold-adapted fishes – to quantify additive and interactive effects of climate, invasive species and land use on population dynamics (abundance, variability and growth rate).Populations were generally depressed, more variable and declining where spawning and rearing stream habitat was limited, invasive species and land use were prevalent and stream temperatures were highest. Increasing stream temperature acted additively and independently, whereas land use and invasive species had additive and interactive effects (i.e. the impact of one stressor depended on exposure to the other stressor).Most (58%–78%) of the explained variation in population dynamics was attributed to the presence of invasive species, differences in life history and management actions in foraging habitats in rivers, lakes and reservoirs. Although invasive fishes had strong negative effects on populations in foraging habitats, proactive control programmes appeared to effectively temper their negative impact.Synthesis and applications. Long-term demographic data emphasize that climate warming will exacerbate imperilment of cold-water specialists like bull trout, yet other stressors – especially invasive fishes – are immediate threats that can be addressed by proactive management actions. Therefore, climate-adaptation strategies for freshwater biodiversity should consider existing abiotic and biotic stressors, some of which provide potential and realized opportunity for conservation of freshwater biodiversity in a warming world.

Potential Climate Change Impacts on the Built Environment in the United States and Implications for Sustainability

NASA Astrophysics Data System (ADS)

Quattrochi, D.

2012-12-01

The built environment consists of components that have been made by humans at a range of scales from small (e.g., houses, shopping malls) to large (e.g., transportation networks) to highly modified landscapes such as cities. The impacts of climate change on the built environment, therefore, may have a multitude of effects on humans and the land. The impact of climate change may be exacerbated by the interaction of different events that singly may be minor, but together may have a synergistic set of impacts that are significant. Also, there may be feedback mechanisms wherein the built environment, particularly in the form of cities, may affect weather and the climate on local and regional scales. Besides having a host of such interactions, the impacts of climate change on urban areas will likely have thresholds, below which effects are incidental or of mild consequence, but beyond which the effects quickly become major. Hence, a city may be able to cope with prolonged heat waves, but if this is combined with severe drought, the overall result could be significant or even catastrophic, as accelerating demand for energy to cooling taxes water supplies needed both for energy supply and municipal water needs. Moreover, urban areas may be affected by changes in daily and seasonal high or low temperatures or precipitation, which may have a much more prolonged impact than the direct effect of these events. Thus, the cumulative impacts of multiple events may be more severe than those of any single event. Primary hazards include sea level rise and coastal storms, heat waves, intense precipitation, drought, extreme wind events, urban heat islands, and secondary air pollutants, and cold air events including frozen precipitation. Indicators need to be developed to provide a consistent, objective, and transparent overview of major variations in climate impacts, vulnerabilities, adaptation, and mitigation activities. Overall, indicators of climate change on the built environment should: 1) provide meaningful, authoritative climate-relevant measures about the status, rates, and trends of key physical, ecological, and societal variables and values to inform decisions on management, research, and education at regional to national scales; 2) identify climate-related conditions and impacts to help develop effective mitigation and adaptation measures and reduce costs of management; and 3) document and communicate the climate-driven dynamic nature and condition of Earth's systems and societies, and provide a coordinated. This presentation will provide an overview of possible climate impacts on the built environment. Also, given that spatial analysis and remote sensing techniques will be of paramount importance in assessing these impacts and in preparing adaptation strategies, the presentation will provide examples of how these techniques can be used to identify potential impacts of climate change on the built environment.

Final report on a cold climate permeable interlocking concrete pavement test facility at the University of New Hampshire Stormwater Center.

DOT National Transportation Integrated Search

2013-05-01

University of New Hampshire Stormwater Center (UNHSC) completed a two year field verification study of a permeable interlocking concrete pavement (PICP) stormwater management system. The purpose of this study was to evaluate the cold climate function...

Performance of a Battery Electric Vehicle in the Cold Climate and Hilly Terrain of Vermont

DOT National Transportation Integrated Search

2008-12-23

The goal of this research project was to determine the performance of a battery electric vehicle (BEV) in the cold climate and hilly terrain of Vermont. For this study, a 2005 Toyota Echo was converted from an internal combustion engine (ICE) vehicle...

Impact of cold climates on vehicle emissions: the cold start air toxics pulse : final report.

DOT National Transportation Integrated Search

2016-09-21

This project measured cold start emissions from four vehicles in winter using fast response instrumentation to accurately measure the : time variation of the cold start emission pulse. Seventeen successful tests were conducted over a temperature rang...

The DYNAFLUX / DYNACOLD (Dynamics, Fluxes, Stability, Succession and Landscape Formation in Cold Environments) Network (2004-2017)

NASA Astrophysics Data System (ADS)

Beylich, Achim A.

2017-04-01

There is a wide range of high-latitude and high-altitude cold climate landscapes within Europe, covering a significant proportion of the total land surface area. This spectrum of defined cold-climate landscapes represents a variety of stages of deglaciation history and landscape formation. We can find landscapes at different levels of postglacial stabilization which is providing the unique opportunity to study the interactions between geo-, bio-, social and socio-economic systems at the land surface. The DYNAFLUX / DYNACOLD Network (2004-2017) bridges across the geo-, bio-, social and socio-economic sciences in order to analyze the complex dynamics of adjustment, stabilization, succession and landscape formation during and after ice retreat and under ongoing anthropogenic influences. The network provides a multidisciplinary forum where researchers come together and discuss. In addition, this network is linking a number of other scientific networks, working groups and programs and creates an umbrella network and a forum for sharing knowledge and experience. The scientific focus of DYNAFLUX / DYNACOLD is also relevant for a number of end users, including risk and vulnerability assessment, sustainable land use, land management and conservation. In addition, present key questions related to environmental change like, e.g., hazards, permafrost degradation and loss of biodiversity are addressed and discussed. Further information is found under http://www.ngu.no/sediflux.

Heat or Cold: Which One Exerts Greater Deleterious Effects on Health in a Basin Climate City? Impact of Ambient Temperature on Mortality in Chengdu, China.

PubMed

Cui, Yan; Yin, Fei; Deng, Ying; Volinn, Ernest; Chen, Fei; Ji, Kui; Zeng, Jing; Zhao, Xing; Li, Xiaosong

2016-12-10

Background : Although studies from many countries have estimated the impact of ambient temperature on mortality, few have compared the relative impacts of heat and cold on health, especially in basin climate cities. We aimed to quantify the impact of ambient temperature on mortality, and to compare the contributions of heat and cold in a large basin climate city, i.e., Chengdu (Sichuan Province, China); Methods : We estimated the temperature-mortality association with a distributed lag non-linear model (DLNM) with a maximum lag-time of 21 days while controlling for long time trends and day of week. We calculated the mortality risk attributable to heat and cold, which were defined as temperatures above and below an "optimum temperature" that corresponded to the point of minimum mortality. In addition, we explored effects of individual characteristics; Results : The analysis provides estimates of the overall mortality burden attributable to temperature, and then computes the components attributable to heat and cold. Overall, the total fraction of deaths caused by both heat and cold was 10.93% (95%CI: 7.99%-13.65%). Taken separately, cold was responsible for most of the burden (estimate 9.96%, 95%CI: 6.90%-12.81%), while the fraction attributable to heat was relatively small (estimate 0.97%, 95%CI: 0.46%-2.35%). The attributable risk (AR) of respiratory diseases was higher (19.69%, 95%CI: 14.45%-24.24%) than that of cardiovascular diseases (11.40%, 95%CI: 6.29%-16.01%); Conclusions : In Chengdu, temperature was responsible for a substantial fraction of deaths, with cold responsible for a higher proportion of deaths than heat. Respiratory diseases exert a larger effect on death than other diseases especially on cold days. There is potential to reduce respiratory-associated mortality especially among the aged population in basin climate cities when the temperature deviates beneath the optimum. The result may help to comprehensively assess the impact of ambient temperature in basin cities, and further facilitate an appropriate estimate of the health consequences of various climate-change scenarios.

Heat or Cold: Which One Exerts Greater Deleterious Effects on Health in a Basin Climate City? Impact of Ambient Temperature on Mortality in Chengdu, China

PubMed Central

Cui, Yan; Yin, Fei; Deng, Ying; Volinn, Ernest; Chen, Fei; Ji, Kui; Zeng, Jing; Zhao, Xing; Li, Xiaosong

2016-01-01

Background: Although studies from many countries have estimated the impact of ambient temperature on mortality, few have compared the relative impacts of heat and cold on health, especially in basin climate cities. We aimed to quantify the impact of ambient temperature on mortality, and to compare the contributions of heat and cold in a large basin climate city, i.e., Chengdu (Sichuan Province, China); Methods: We estimated the temperature-mortality association with a distributed lag non-linear model (DLNM) with a maximum lag-time of 21 days while controlling for long time trends and day of week. We calculated the mortality risk attributable to heat and cold, which were defined as temperatures above and below an “optimum temperature” that corresponded to the point of minimum mortality. In addition, we explored effects of individual characteristics; Results: The analysis provides estimates of the overall mortality burden attributable to temperature, and then computes the components attributable to heat and cold. Overall, the total fraction of deaths caused by both heat and cold was 10.93% (95%CI: 7.99%–13.65%). Taken separately, cold was responsible for most of the burden (estimate 9.96%, 95%CI: 6.90%–12.81%), while the fraction attributable to heat was relatively small (estimate 0.97%, 95%CI: 0.46%–2.35%). The attributable risk (AR) of respiratory diseases was higher (19.69%, 95%CI: 14.45%–24.24%) than that of cardiovascular diseases (11.40%, 95%CI: 6.29%–16.01%); Conclusions: In Chengdu, temperature was responsible for a substantial fraction of deaths, with cold responsible for a higher proportion of deaths than heat. Respiratory diseases exert a larger effect on death than other diseases especially on cold days. There is potential to reduce respiratory-associated mortality especially among the aged population in basin climate cities when the temperature deviates beneath the optimum. The result may help to comprehensively assess the impact of ambient temperature in basin cities, and further facilitate an appropriate estimate of the health consequences of various climate-change scenarios. PMID:27973401

Isotopic evidence of multiple controls on atmospheric oxidants over climate transitions

NASA Astrophysics Data System (ADS)

Geng, Lei; Murray, Lee T.; Mickley, Loretta J.; Lin, Pu; Fu, Qiang; Schauer, Andrew J.; Alexander, Becky

2017-06-01

The abundance of tropospheric oxidants, such as ozone (O3) and hydroxyl (OH) and peroxy radicals (HO2 + RO2), determines the lifetimes of reduced trace gases such as methane and the production of particulate matter important for climate and human health. The response of tropospheric oxidants to climate change is poorly constrained owing to large uncertainties in the degree to which processes that influence oxidants may change with climate and owing to a lack of palaeo-records with which to constrain levels of atmospheric oxidants during past climate transitions. At present, it is thought that temperature-dependent emissions of tropospheric O3 precursors and water vapour abundance determine the climate response of oxidants, resulting in lower tropospheric O3 in cold climates while HOx (= OH + HO2 + RO2) remains relatively buffered. Here we report observations of oxygen-17 excess of nitrate (a proxy for the relative abundance of atmospheric O3 and HOx) from a Greenland ice core over the most recent glacial-interglacial cycle and for two Dansgaard-Oeschger events. We find that tropospheric oxidants are sensitive to climate change with an increase in the O3/HOx ratio in cold climates, the opposite of current expectations. We hypothesize that the observed increase in O3/HOx in cold climates is driven by enhanced stratosphere-to-troposphere transport of O3, and that reactive halogen chemistry is also enhanced in cold climates. Reactive halogens influence the oxidative capacity of the troposphere directly as oxidants themselves and indirectly via their influence on O3 and HOx. The strength of stratosphere-to-troposphere transport is largely controlled by the Brewer-Dobson circulation, which may be enhanced in colder climates owing to a stronger meridional gradient of sea surface temperatures, with implications for the response of tropospheric oxidants and stratospheric thermal and mass balance. These two processes may represent important, yet relatively unexplored, climate feedback mechanisms during major climate transitions.

New Insights into the 8.2 ka Cold Event and Subsequent Climate Recovery in Central Europe Provided by a Precisely Dated Ostracod δ18O Record from Mondsee (Austria)

NASA Astrophysics Data System (ADS)

Lauterbach, S.; Andersen, N.; Brauer, A.; Erlenkeuser, H.; Danielopol, D. L.; Namiotko, T.; Huels, M.; Belmecheri, S.; Nantke, C.; Meyer, H.; Chapligin, B.; von Grafenstein, U.

2015-12-01

As evidenced by numerous palaeoclimate records worldwide, the Holocene warm period has been interrupted by several short, low-amplitude cold episodes. Among these, the so-called 8.2 ka cold event is the most prominent Holocene climate perturbation but despite extensive studies, knowledge about its synchrony in different areas and particularly about the dynamics of subsequent climate recovery is still limited. As this is of crucial importance for understanding the complex mechanisms that trigger rapid climate fluctuations and for testing the performance of climate models, new data on the 8.2 ka cold event are needed. Here we present a new sub-decadally resolved, precisely dated oxygen isotope (δ18O) record for the interval 7.7-8.7 ka BP obtained from benthic ostracods preserved in the varved lake sediments of Mondsee (Austria), providing new insights into climate development around the 8.2 ka cold event in Central Europe. The new high-resolution δ18O data set reveals the occurrence of a pronounced cold spell around 8.2 ka BP, whose amplitude (~1.0 ‰, equivalent to a 1.5-2.0 °C cooling), total duration (151 a) and absolute dating (8231-8080 a BP, i.e. calendar years before AD 1950) perfectly agree with results from other Northern Hemisphere palaeoclimate archives, e.g. the precisely dated Greenland ice cores. In addition, the Mondsee δ18O record also indicates a 75-year-long air temperature overshoot of ~0.7 °C directly after the 8.2 ka event (between 8080 and 8005 a BP), which is so far only poorly documented in the mid-latitudes. However, this observation is consistent with results from coupled climate models and high-latitude proxy records, thus likely reflecting a hemispheric-scale climate signal driven by enhanced resumption of the Atlantic meridional overturning circulation (AMOC), which apparently also caused synchronous migrations of atmospheric and oceanic front systems in the North Atlantic realm.

Future Climate Change Will Favour Non-Specialist Mammals in the (Sub)Arctics

PubMed Central

Hof, Anouschka R.; Jansson, Roland; Nilsson, Christer

2012-01-01

Arctic and subarctic (i.e., [sub]arctic) ecosystems are predicted to be particularly susceptible to climate change. The area of tundra is expected to decrease and temperate climates will extend further north, affecting species inhabiting northern environments. Consequently, species at high latitudes should be especially susceptible to climate change, likely experiencing significant range contractions. Contrary to these expectations, our modelling of species distributions suggests that predicted climate change up to 2080 will favour most mammals presently inhabiting (sub)arctic Europe. Assuming full dispersal ability, most species will benefit from climate change, except for a few cold-climate specialists. However, most resident species will contract their ranges if they are not able to track their climatic niches, but no species is predicted to go extinct. If climate would change far beyond current predictions, however, species might disappear. The reason for the relative stability of mammalian presence might be that arctic regions have experienced large climatic shifts in the past, filtering out sensitive and range-restricted taxa. We also provide evidence that for most (sub)arctic mammals it is not climate change per se that will threaten them, but possible constraints on their dispersal ability and changes in community composition. Such impacts of future changes in species communities should receive more attention in literature. PMID:23285098

Higher climatological temperature sensitivity of soil carbon in cold than warm climates

NASA Astrophysics Data System (ADS)

Koven, Charles D.; Hugelius, Gustaf; Lawrence, David M.; Wieder, William R.

2017-11-01

The projected loss of soil carbon to the atmosphere resulting from climate change is a potentially large but highly uncertain feedback to warming. The magnitude of this feedback is poorly constrained by observations and theory, and is disparately represented in Earth system models (ESMs). To assess the climatological temperature sensitivity of soil carbon, we calculate apparent soil carbon turnover times that reflect long-term and broad-scale rates of decomposition. Here, we show that the climatological temperature control on carbon turnover in the top metre of global soils is more sensitive in cold climates than in warm climates and argue that it is critical to capture this emergent ecosystem property in global-scale models. We present a simplified model that explains the observed high cold-climate sensitivity using only the physical scaling of soil freeze-thaw state across climate gradients. Current ESMs fail to capture this pattern, except in an ESM that explicitly resolves vertical gradients in soil climate and carbon turnover. An observed weak tropical temperature sensitivity emerges in a different model that explicitly resolves mineralogical control on decomposition. These results support projections of strong carbon-climate feedbacks from northern soils and demonstrate a method for ESMs to capture this emergent behaviour.

Subsurface Salts in Antarctic Dry Valley Soils

NASA Technical Reports Server (NTRS)

Englert, P.; Bishop, J. L.; Gibson, E. K.; Koeberl, C.

2013-01-01

The distribution of water-soluble ions, major and minor elements, and other parameters were examined to determine the extent and effects of chemical weathering on cold desert soils. Patterns at the study sites support theories of multiple salt forming processes, including marine aerosols and chemical weathering of mafic minerals. Periodic solar-mediated ionization of atmospheric nitrogen might also produce high nitrate concentrations found in older sediments. Chemical weathering, however, was the major contributor of salts in Antarctic Dry Valleys. The Antarctic Dry Valleys represent a unique analog for Mars, as they are extremely cold and dry desert environments. Similarities in the climate, surface geology, and chemical properties of the Dry Valleys to that of Mars imply the possible presence of these soil formation mechanisms on Mars, other planets and icy satellites.

Cold Fronts in RegCM/HadGEM simulations over South America

NASA Astrophysics Data System (ADS)

Pampuch, Luana; Marcos de Jesus, Eduardo; Porfírio da Rocha, Rosmeri; Ambrizzi, Tércio

2017-04-01

Cold front is one of the most important systems that contribute for precipitation over South America. The representation of this system in climate models is important for a better representation of the precipitation. The Regional Climate Model RegCM is widely used for climate studies in South America, being important to understand how this model represents the cold fronts. A climatology (from 1979-2004) of the number of cold fronts in each season for RegCM4 simulations over South America CORDEX domain nested in HadGEM2-ES. The simulated climatology was compared with ERA-Interim reanalysis cold fronts climatology over the South America and adjacent South Atlantic Ocean. The cold fronts tracking for the model and the reanalysis were performed using an objective methodology based on decrease of air temperature in 925hPa, shift of meridional wind in 925hPa from northern to southern quadrant and increased in sea level pressure. The main differences were observed on summer and winter. On summer the model overestimate the number of cold fronts over southeastern South America and adjacent Atlantic Ocean; and underestimate it over central-south Argentina and Atlantic Ocean. On winter, the signs were opposite of that summer. On autumn and spring the differences were smaller and occurs mainly over all South Atlantic and north Argentina.

Deacclimation may be crucial for winter survival of cereals under warming climate.

PubMed

Rapacz, Marcin; Jurczyk, Barbara; Sasal, Monika

2017-03-01

Climate warming can change the winter weather patterns. Warmer temperatures during winter result in a lower risk of extreme freezing events. On the other hand the predicted warm gaps during winter will decrease their freezing tolerance. Both contradict effects will affect winter survival but their resultant effect is unclear. In this paper, we demonstrate that climate warming may result in a decrease in winter survival of plants. A field study of winterhardiness of common wheat and triticale was established at 11 locations and repeated during three subsequent winters. The freezing tolerance of the plants was studied after controlled cold acclimation and de-acclimation using both plant survival analysis and chlorophyll fluorescence measurements. Cold deacclimation resistance was shown to be independent from cold acclimation ability. Further, cold deacclimation resistance appeared to be crucial for overwintering when deacclimation conditions occurred in the field. The shortening of uninterrupted cold acclimation may increase cold deacclimation efficiency, which could threaten plant survival during warmer winters. Measurements of chlorophyll fluorescence transient showed some differences triggered by freezing before and after deacclimation. We conclude that cold deacclimation resistance should be considered in the breeding of winter cereals and in future models of winter damage risk. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Field study of thermal comfort in non-air-conditioned buildings in a tropical island climate.

PubMed

Lu, Shilei; Pang, Bo; Qi, Yunfang; Fang, Kun

2018-01-01

The unique geographical location of Hainan makes its climate characteristics different from inland areas in China. The thermal comfort of Hainan also owes its uniqueness to its tropical island climate. In the past decades, there have been very few studies on thermal comfort of the residents in tropical island areas in China. A thermal environment test for different types of buildings in Hainan and a thermal comfort field investigation of 1944 subjects were conducted over a period of about two months. The results of the survey data show that a high humidity environment did not have a significant impact on human comfort. The neutral temperature for the residents in tropical island areas was 26.1 °C, and the acceptable temperature range of thermal comfort was from 23.1 °C to 29.1 °C. Residents living in tropical island areas showed higher heat resistance capacity, but lower cold tolerance than predicted. The neutral temperature for females (26.3 °C) was higher than for males (25.8 °C). Additionally, females were more sensitive to air temperature than males. The research conclusions can play a guiding role in the thermal environment design of green buildings in Hainan Province. Copyright © 2017 Elsevier Ltd. All rights reserved.

A Decrease in Temperature and Humidity Precedes Human Rhinovirus Infections in a Cold Climate.

PubMed

Ikäheimo, Tiina M; Jaakkola, Kari; Jokelainen, Jari; Saukkoriipi, Annika; Roivainen, Merja; Juvonen, Raija; Vainio, Olli; Jaakkola, Jouni J K

2016-09-02

Both temperature and humidity may independently or jointly contribute to the risk of human rhinovirus (HRV) infections, either through altered survival and spread of viruses in the environment or due to changes in host susceptibility. This study examined the relationship between short-term variations in temperature and humidity and the risk of HRV infections in a subarctic climate. We conducted a case-crossover study among conscripts (n = 892) seeking medical attention due to respiratory symptoms during their military training and identified 147 HRV cases by real-time PCR. An average temperature, a decline in daily ambient temperature and absolute humidity (AH) during the three preceding days of the onset (hazard period) and two reference periods (a week prior and after the onset) were obtained. The average daily temperature preceding HRV infections was -9.9 ± 4.9 °C and the average AH was 2.2 ± 0.9 g/m³. An average (odds ratios (OR) 1.07 (95% confidence interval (CI) 1.00-1.15)) and maximal (OR 1.08 (1.01-1.17)) change in temperature increased the risk of HRV infections by 8% per 1 °C decrease. An average (OR 1.20 (CI 1.03-1.40)) and maximal decrease (OR 1.13 (CI 0.96-1.34)) in AH increased the risk of HRV infection by 13% and 20% per 0.5 g/m³ decrease. A higher average temperature during the three preceding days was positively associated with HRV infections (OR 1.07 (CI 1.00-1.15)). A decrease rather than low temperature and humidity per se during the preceding few days increases the risk of HRV infections in a cold climate. The information is applicable to populations residing in cold climates for appropriate personal protection and prevention of adverse health effects.

A Decrease in Temperature and Humidity Precedes Human Rhinovirus Infections in a Cold Climate

PubMed Central

Ikäheimo, Tiina M.; Jaakkola, Kari; Jokelainen, Jari; Saukkoriipi, Annika; Roivainen, Merja; Juvonen, Raija; Vainio, Olli; Jaakkola, Jouni J.K.

2016-01-01

Both temperature and humidity may independently or jointly contribute to the risk of human rhinovirus (HRV) infections, either through altered survival and spread of viruses in the environment or due to changes in host susceptibility. This study examined the relationship between short-term variations in temperature and humidity and the risk of HRV infections in a subarctic climate. We conducted a case-crossover study among conscripts (n = 892) seeking medical attention due to respiratory symptoms during their military training and identified 147 HRV cases by real-time PCR. An average temperature, a decline in daily ambient temperature and absolute humidity (AH) during the three preceding days of the onset (hazard period) and two reference periods (a week prior and after the onset) were obtained. The average daily temperature preceding HRV infections was −9.9 ± 4.9 °C and the average AH was 2.2 ± 0.9 g/m3. An average (odds ratios (OR) 1.07 (95% confidence interval (CI) 1.00–1.15)) and maximal (OR 1.08 (1.01–1.17)) change in temperature increased the risk of HRV infections by 8% per 1 °C decrease. An average (OR 1.20 (CI 1.03–1.40)) and maximal decrease (OR 1.13 (CI 0.96–1.34)) in AH increased the risk of HRV infection by 13% and 20% per 0.5 g/m3 decrease. A higher average temperature during the three preceding days was positively associated with HRV infections (OR 1.07 (CI 1.00–1.15)). A decrease rather than low temperature and humidity per se during the preceding few days increases the risk of HRV infections in a cold climate. The information is applicable to populations residing in cold climates for appropriate personal protection and prevention of adverse health effects. PMID:27598190

Cold Regime Interannual Variability of Primary and Secondary Producer Community Composition in the Southeastern Bering Sea

PubMed Central

Stauffer, Beth A.; Miksis-Olds, Jennifer; Goes, Joaquim I.

2015-01-01

Variability of hydrographic conditions and primary and secondary productivity between cold and warm climatic regimes in the Bering Sea has been the subject of much study in recent years, while interannual variability within a single regime and across multiple trophic levels has been less well-documented. Measurements from an instrumented mooring on the southeastern shelf of the Bering Sea were analyzed for the spring-to-summer transitions within the cold regime years of 2009–2012 to investigate the interannual variability of hydrographic conditions, primary producer biomass, and acoustically-derived secondary producer and consumer abundance and community structure. Hydrographic conditions in 2012 were significantly different than in 2009, 2010, and 2011, driven largely by increased ice extent and thickness, later ice retreat, and earlier stratification of the water column. Primary producer biomass was more tightly coupled to hydrographic conditions in 2012 than in 2009 or 2011, and shallow and mid-column phytoplankton blooms tended to occur independent of one another. There was a high degree of variability in the relationships between different classes of secondary producers and hydrographic conditions, evidence of significant intra-consumer interactions, and trade-offs between different consumer size classes in each year. Phytoplankton blooms stimulated different populations of secondary producers in each year, and summer consumer populations appeared to determine dominant populations in the subsequent spring. Overall, primary producers and secondary producers were more tightly coupled to each other and to hydrographic conditions in the coldest year compared to the warmer years. The highly variable nature of the interactions between the atmospherically-driven hydrographic environment, primary and secondary producers, and within food webs underscores the need to revisit how climatic regimes within the Bering Sea are defined and predicted to function given changing climate scenarios. PMID:26110822

Ice age fish in a warming world: minimal variation in thermal acclimation capacity among lake trout (Salvelinus namaycush) populations

PubMed Central

Kelly, Nicholas I.; Burness, Gary; McDermid, Jenni L.; Wilson, Chris C.

2014-01-01

In the face of climate change, the persistence of cold-adapted species will depend on their adaptive capacity for physiological traits within and among populations. The lake trout (Salvelinus namaycush) is a cold-adapted salmonid and a relict from the last ice age that is well suited as a model species for studying the predicted effects of climate change on coldwater fishes. We investigated the thermal acclimation capacity of upper temperature resistance and metabolism of lake trout from four populations across four acclimation temperatures. Individuals were reared from egg fertilization onward in a common environment and, at 2 years of age, were acclimated to 8, 11, 15 or 19°C. Although one population had a slightly higher maximal metabolic rate (MMR), higher metabolic scope for activity and faster metabolic recovery across all temperatures, there was no interpopulation variation for critical thermal maximum (CTM) or routine metabolic rate (RMR) or for the thermal acclimation capacity of CTM, RMR, MMR or metabolic scope. Across the four acclimation temperatures, there was a 3°C maximal increase in CTM and 3-fold increase in RMR for all populations. Above 15°C, a decline in MMR and increase in RMR resulted in sharply reduced metabolic scope for all populations acclimated at 19°C. Together, these data suggest there is limited variation among lake trout populations in thermal physiology or capacity for thermal acclimatization, and that climate change may impact lake trout populations in a similar manner across a wide geographical range. Understanding the effect of elevated temperatures on the thermal physiology of this economically and ecologically important cold-adapted species will help inform management and conservation strategies for the long-term sustainability of lake trout populations. PMID:27293646

Cold Regime interannual variability of primary and secondary producer community composition in the southeastern Bering Sea.

PubMed

Stauffer, Beth A; Miksis-Olds, Jennifer; Goes, Joaquim I

2015-01-01

Variability of hydrographic conditions and primary and secondary productivity between cold and warm climatic regimes in the Bering Sea has been the subject of much study in recent years, while interannual variability within a single regime and across multiple trophic levels has been less well-documented. Measurements from an instrumented mooring on the southeastern shelf of the Bering Sea were analyzed for the spring-to-summer transitions within the cold regime years of 2009-2012 to investigate the interannual variability of hydrographic conditions, primary producer biomass, and acoustically-derived secondary producer and consumer abundance and community structure. Hydrographic conditions in 2012 were significantly different than in 2009, 2010, and 2011, driven largely by increased ice extent and thickness, later ice retreat, and earlier stratification of the water column. Primary producer biomass was more tightly coupled to hydrographic conditions in 2012 than in 2009 or 2011, and shallow and mid-column phytoplankton blooms tended to occur independent of one another. There was a high degree of variability in the relationships between different classes of secondary producers and hydrographic conditions, evidence of significant intra-consumer interactions, and trade-offs between different consumer size classes in each year. Phytoplankton blooms stimulated different populations of secondary producers in each year, and summer consumer populations appeared to determine dominant populations in the subsequent spring. Overall, primary producers and secondary producers were more tightly coupled to each other and to hydrographic conditions in the coldest year compared to the warmer years. The highly variable nature of the interactions between the atmospherically-driven hydrographic environment, primary and secondary producers, and within food webs underscores the need to revisit how climatic regimes within the Bering Sea are defined and predicted to function given changing climate scenarios.

Heterologous expression of antifreeze protein gene AnAFP from Ammopiptanthus nanus enhances cold tolerance in Escherichia coli and tobacco.

PubMed

Deng, Long-Qun; Yu, Hao-Qiang; Liu, Yan-Ping; Jiao, Pei-Pei; Zhou, Shu-Feng; Zhang, Su-Zhi; Li, Wan-Chen; Fu, Feng-Ling

2014-04-10

Antifreeze proteins are a class of polypeptides produced by certain animals, plants, fungi and bacteria that permit their survival under the subzero environments. Ammopiptanthus nanus is the unique evergreen broadleaf bush endemic to the Mid-Asia deserts. It survives at the west edge of the Tarim Basin from the disappearance of the ancient Mediterranean in the Tertiary Period. Its distribution region is characterized by the arid climate and extreme temperatures, where the extreme temperatures range from -30 °C to 40 °C. In the present study, the antifreeze protein gene AnAFP of A. nanus was used to transform Escherichia coli and tobacco, after bioinformatics analysis for its possible function. The transformed E. coli strain expressed the heterologous AnAFP gene under the induction of isopropyl β-D-thiogalactopyranoside, and demonstrated significant enhancement of cold tolerance. The transformed tobacco lines expressed the heterologous AnAFP gene in response to cold stress, and showed a less change of relative electrical conductivity under cold stress, and a less wilting phenotype after 16 h of -3 °C cold stress and thawing for 1h than the untransformed wild-type plants. All these results imply the potential value of the AnAFP gene to be used in genetic modification of commercially important crops for improvement of cold tolerance. Copyright © 2014 Elsevier B.V. All rights reserved.

Optimization of Domestic-Size Renewable Energy System Designs Suitable for Cold Climate Regions

NASA Astrophysics Data System (ADS)

Akpan, Itoro Etim; Sasaki, Masafumi; Endoh, Noboru

Five different kinds of domestic-size renewable energy system configurations for very cold climate regions were investigated. From detailed numerical modeling and system simulations, it was found that the consumption of fuel oil for the auxiliary boiler in residential-type households can almost be eliminated with a renewable energy system that incorporates photovoltaic panel arrays for electricity generation and two storage tanks: a well-insulated electric water storage tank that services the hot water loads, and a compact boiler/geothermal heat pump tank for room heating during very cold seasons. A reduction of Greenhouse Gas Emissions (GHG) of about 28% was achieved for this system compared to an equivalent conventional system. The near elimination of the use of fuel oil in this system makes it very promising for very cold climate regions in terms of energy savings because the running cost is not so dependent on the unstable nature of global oil prices.

The lab and the land: overcoming the Arctic in Cold War Alaska.

PubMed

Farish, Matthew

2013-03-01

The militarization of Alaska during and after World War II created an extraordinary set of new facilities. But it also reshaped the imaginative role of Alaska as a hostile environment, where an antagonistic form of nature could be defeated with the appropriate combination of technology and training. One of the crucial sites for this reformulation was the Arctic Aeromedical Laboratory, based at Ladd Air Force Base in Fairbanks. In the first two decades of the Cold War, its employees conducted numerous experiments on acclimatization and survival. The laboratory is now best known for an infamous set of tests involving the application of radioactive tracers to indigenous Alaskans--experiments publicized by post-Cold War panels established to evaluate the tragic history of atomic-era human subject research. But little else has been written about the laboratory's relationship with the populations and landscapes that it targeted for study. This essay presents the laboratory as critical to Alaska's history and the history of the Cold War sciences. A consideration of the laboratory's various projects also reveals a consistent fascination with race. Alaskan Natives were enrolled in experiments because their bodies were understood to hold clues to the mysteries of northern nature. A scientific solution would aid American military campaigns not only in Alaska, but in cold climates everywhere.

Variability of cold season surface air temperature over northeastern China and its linkage with large-scale atmospheric circulations

NASA Astrophysics Data System (ADS)

Zhuang, Yuanhuang; Zhang, Jingyong; Wang, Lin

2018-05-01

Cold temperature anomalies and extremes have profound effects on the society, the economy, and the environment of northeastern China (NEC). In this study, we define the cold season as the months from October to April, and investigate the variability of cold season surface air temperature (CSAT) over NEC and its relationships with large-scale atmospheric circulation patterns for the period 1981-2014. The empirical orthogonal function (EOF) analysis shows that the first EOF mode of the CSAT over NEC is characterized by a homogeneous structure that describes 92.2% of the total variance. The regionally averaged CSAT over NEC is closely linked with the Arctic Oscillation ( r = 0.62, 99% confidence level) and also has a statistically significant relation with the Polar/Eurasian pattern in the cold season. The positive phases of the Arctic Oscillation and the Polar/Eurasian pattern tend to result in a positive geopotential height anomaly over NEC and a weakened East Asian winter monsoon, which subsequently increase the CSAT over NEC by enhancing the downward solar radiation, strengthening the subsidence warming and warm air advection. Conversely, the negative phases of these two climate indices result in opposite regional atmospheric circulation anomalies and decrease the CSAT over NEC.

Habitat Variability and Ethnic Diversity in Northern Tibetan Plateau.

PubMed

Jia, Xin; Lee, Harry F; Cui, Mengchun; Liu, Chao; Zeng, Lin; Yue, Ricci P H; Zhao, Yang; Lu, Huayu

2017-04-20

There are 56 officially-recognized ethnic groups in China. However, the distinct geographic patterns of various ethnic groups in relation to the physical environment in China have rarely been investigated. Based on the geo-referenced physical environmental parameters of 455 Han, Tu, Hui, Salar, Mongolian, and Tibetan communities in Qinghai, we found that the communities could be statistically demarcated by temperature and aridity threshold according to their ethnicity, implying that the geographic distribution of each ethnic group is mediated by the physical environment. We also observed that the habitat of each ethnic group is ecologically compatible with current subsistence strategies. Tibetans settle in cold and humid high-altitude regions owing to the cultivation of highland barley and the breeding of yak, dzo, Tibetan sheep and Tibetan goat. Mongolians survive by animal husbandry in cold and dry grassland areas. Han and Tu people settle in the Huangshui River Valley, which offers relatively humid climate and flat land for agriculture. Hui and Salar people occupy the Yellow River Valley with its relatively arid environment and grassland vegetation suitable for animal breeding. Our findings offer a new perspective in explaining the geographic patterns and the varieties of ethnic groups in China and elsewhere.

Habitat Variability and Ethnic Diversity in Northern Tibetan Plateau

NASA Astrophysics Data System (ADS)

Jia, Xin; Lee, Harry F.; Cui, Mengchun; Liu, Chao; Zeng, Lin; Yue, Ricci P. H.; Zhao, Yang; Lu, Huayu

2017-04-01

There are 56 officially-recognized ethnic groups in China. However, the distinct geographic patterns of various ethnic groups in relation to the physical environment in China have rarely been investigated. Based on the geo-referenced physical environmental parameters of 455 Han, Tu, Hui, Salar, Mongolian, and Tibetan communities in Qinghai, we found that the communities could be statistically demarcated by temperature and aridity threshold according to their ethnic populations, implying that the geographic distribution of each ethnic group is mediated by the physical environment. We also observed that the habitat of each ethnic group is ecologically compatible with current subsistence strategies. Tibetans settle in cold high-altitude regions owing to the cultivation of highland barley and the breeding of yak, dzo, Tibetan sheep and Tibetan goat. Mongolians survive by animal husbandry in cold and humid grassland areas. The Han and Tu ethnic groups settle in the Huangshui River Valley, which offers relatively humid climate and flat land for agriculture. The Hui and Salar ethnic groups occupy the Yellow River Valley with its relatively arid environment and grassland vegetation suitable for animal breeding. Our findings offer a new perspective in explaining the geographic pattern and the variety of ethnic groups in China and elsewhere.

Assessing the Climate Sensitivity of Cold Content and Snowmelt in Seasonal Alpine and Subalpine Snowpacks

NASA Astrophysics Data System (ADS)

Jennings, K. S.; Molotch, N. P.

2016-12-01

In cold, high-elevation sites, snowpack cold content acts as a buffer against climate warming by resisting snowmelt during periods of positive energy fluxes. To test the climate sensitivity of cold content and snowmelt, we employed the physical SNOWPACK snow model, forced with a 23-year, hourly, quality-controlled, gap-filled meteorological dataset from the Niwot Ridge Long Term Ecological Research (LTER) site in the Front Range mountains of Colorado. SNOWPACK was run at two points with seasonal snowpacks within the LTER, one in the alpine (3528 m) and one in the subalpine (3022 m). Model output was validated using snow water equivalent (SWE), snowpack temperature, and cold content data from snow pits dug near the met stations and automated SWE data from nearby SNOTEL snow pillows. Cold content accumulates primarily through additions of new snow, while negative energy fluxes—cooling through longwave emission and sublimation—play a lesser role, particularly in the deeper snowpack of the alpine. On average, the snowpack energy balance becomes positive on April 1 in the alpine and March 8 in the subalpine. Peak SWE occurs after these dates and its timing is primarily determined by the amount of precipitation received after peak cold content, with persistent snowfall delaying the main snowmelt pulse. Years with lower cold content, due to reduced precipitation and/or increased air temperature, experience an earlier positive energy balance with more melt events occurring before the date of peak SWE, which has implications for soil moisture, streamflow volume and timing, water uptake by vegetation, and microbial respiration. Synthetic warming experiments show significant cold content reductions and increased late-winter/early-spring melt as positive energy balances occur earlier in the snow season (a forward shift between 5.1 and 21.0 days per °C of warming). These results indicate cold, high-elevation sites, which are critical for water resources in the western United States, may lose their cold content buffering capacity and begin to experience stronger negative trends in SWE with increased climate warming, even as the majority of winter precipitation continues to fall as snow.

Communal nesting under climate change: fitness consequences of higher incubation temperatures for a nocturnal lizard.

PubMed

Dayananda, Buddhi; Gray, Sarah; Pike, David; Webb, Jonathan K

2016-07-01

Communal nesting lizards may be vulnerable to climate warming, particularly if air temperatures regulate nest temperatures. In southeastern Australia, velvet geckos Oedura lesueurii lay eggs communally inside rock crevices. We investigated whether increases in air temperatures could elevate nest temperatures, and if so, how this could influence hatching phenotypes, survival, and population dynamics. In natural nests, maximum daily air temperature influenced mean and maximum daily nest temperatures, implying that nest temperatures will increase under climate warming. To determine whether hotter nests influence hatchling phenotypes, we incubated eggs under two fluctuating temperature regimes to mimic current 'cold' nests (mean = 23.2 °C, range 10-33 °C) and future 'hot' nests (27.0 °C, 14-37 °C). 'Hot' incubation temperatures produced smaller hatchlings than did cold temperature incubation. We released individually marked hatchlings into the wild in 2014 and 2015, and monitored their survival over 10 months. In 2014 and 2015, hot-incubated hatchlings had higher annual mortality (99%, 97%) than cold-incubated (11%, 58%) or wild-born hatchlings (78%, 22%). To determine future trajectories of velvet gecko populations under climate warming, we ran population viability analyses in Vortex and varied annual rates of hatchling mortality within the range 78- 96%. Hatchling mortality strongly influenced the probability of extinction and the mean time to extinction. When hatchling mortality was >86%, populations had a higher probability of extinction (PE: range 0.52- 1.0) with mean times to extinction of 18-44 years. Whether future changes in hatchling survival translate into reduced population viability will depend on the ability of females to modify their nest-site choices. Over the period 1992-2015, females used the same communal nests annually, suggesting that there may be little plasticity in maternal nest-site selection. The impacts of climate change may therefore be especially severe on communal nesting species, particularly if such species occupy thermally challenging environments. © 2016 John Wiley & Sons Ltd.

The investigation of terrestrial analogs for the paleoclimate of Mars

NASA Astrophysics Data System (ADS)

Thorpe, M.; Hurowitz, J.; Dehouck, E.

2016-12-01

The paleoclimate of Mars is recorded in sedimentary rocks and deposits, with geochemical and mineralogical lines of evidence illustrating an active hydrologic cycle and aqueous weathering environment. The nature of this paleoclimate remains a debatable subject, with several competing hypothesis existing from warm and wet to cold and icy. However, sedimentary processes in basaltic terrains are understudied, leading to an inadequate reference frame for the sedimentary record of Mars. Therefore, investigating the effects of climate on basaltic terrestrial analogs will help in establishing a context for understanding the ancient conditions of Mars. The Columbia River Basalts in Idaho, USA will serve as conditions in a warm and wet climate, while the weathering of Icelandic Basalts in southwestern Iceland will provide a cold and wet climate scenario. In the warm and wet conditions of Idaho, Miocene basaltic source rock is broken down by physical and chemical weathering, transported by streams and deposited locally as small deltas. The sediment that accumulates preserves the basaltic provenance mineralogy in grain sizes as small as silt. The major elemental geochemistry displays chemical weathering trends that are consistent with decreasing grain size, and interpreted as mafic mineral dissolution (i.e., olivine and pyroxenes). Clay mineral phases are separated into the finest grain size fraction during the sedimentation process and are identified as smectite clays. A similar story of preserving basaltic mineralogy is illustrated by Icelandic deposits, except mechanical breakdown of the sediment appears to have a larger impact. Primary mafic minerals are identified in even the clay size fraction of the Icelandic fluvial delta deposits. Additionally, there are limited abundances of clay mineral phases, with more obvious contributions of poorly crystalline phases in the less than 2 micron fraction. The preservation of basaltic provenance in the mineralogy of sediments generated in two contrasting climates is important to Mars were sedimentary rocks display a primary igneous mineralogy. Weathering trends and the formation of secondary clay and(or) poorly crystalline phases may be the defining tracers for climatic influence on sedimentary processes in basaltic environments.

Assessing the spatiotemporal dynamic of global grassland carbon use efficiency in response to climate change from 2000 to 2013

NASA Astrophysics Data System (ADS)

Yang, Yue; Wang, Zhaoqi; Li, Jianlong; Gang, Chencheng; Zhang, Yanzhen; Odeh, Inakwu; Qi, Jiaguo

2017-05-01

The carbon use efficiency (CUE) of grassland, a ratio of net primary production (NPP) to gross primary productivity (GPP), is an important index representing the capacity of plants to transfer carbon from the atmosphere to terrestrial biomass. In this study, we used the Moderate Resolution Imaging Spectroradiometer (MODIS) data to calculate the global grassland CUE, and explore the spatiotemporal dynamic of global grassland CUE from 2000 to 2013 to discuss the response to climate variations. The results showed that the average annual CUE of different grassland types follows an order of: open shrublands > non-woody grasslands > closed shrublands > woody savannas > savannas. The higher grassland CUE mainly occurred in the regions with cold and dry climate. By contrast, the regions with the lower grassland CUE were mostly in warm and wet environments. Moreover, the CUE exhibited a globally positive correlation with precipitation and a negative correlation with temperature. Therefore, the grassland CUE has considerable spatial variation associated with grassland type, geographical location and climate change.

Late-Glacial to Early Holocene Climate Changes from a Central Appalachians Pollen and Macrofossil Record

NASA Technical Reports Server (NTRS)

Kneller, Margaret; Peteet, Dorothy

1997-01-01

A Late-glacial to early Holocene record of pollen, plant macrofossils and charcoal, based on two cores, is presented for Browns Pond in the central Appalachians of Virginia. An AMS radiocarbon chronology defines the timing of moist and cold excursions, superimposed upon the overall warming trend from 14,200 to 7,500 C-14 yr B.P. This site shows cold, moist conditions from approximately 14,200 to 12,700 C-14 yr B.P., with warming at 12,730, 11,280 and 10,050 C-14 yr B.P. A decrease in deciduous broad-leaved tree taxa and Pinus strobus (haploxylon) pollen, simultaneous with a re-expansion of Abies denotes a brief, cold reversal from 12,260 to 12,200 C-14 yr B.P. A second cold reversal, inferred from increases in montane conifers, is centered at 7,500 C-14 yr B.P. The cold reversals at Browns Pond may be synchronous with climate change in Greenland, and northwestern Europe. Warming at 11,280 C-14 yr B.P. shows the complexity of regional climate responses during the Younger Dryas chronozone.

Frequent floods in the European Alps coincide with cooler periods of the past 2500 years.

PubMed

Glur, Lukas; Wirth, Stefanie B; Büntgen, Ulf; Gilli, Adrian; Haug, Gerald H; Schär, Christoph; Beer, Jürg; Anselmetti, Flavio S

2013-09-26

Severe floods triggered by intense precipitation are among the most destructive natural hazards in Alpine environments, frequently causing large financial and societal damage. Potential enhanced flood occurrence due to global climate change would thus increase threat to settlements, infrastructure, and human lives in the affected regions. Yet, projections of intense precipitation exhibit major uncertainties and robust reconstructions of Alpine floods are limited to the instrumental and historical period. Here we present a 2500-year long flood reconstruction for the European Alps, based on dated sedimentary flood deposits from ten lakes in Switzerland. We show that periods with high flood frequency coincide with cool summer temperatures. This wet-cold synchronism suggests enhanced flood occurrence to be triggered by latitudinal shifts of Atlantic and Mediterranean storm tracks. This paleoclimatic perspective reveals natural analogues for varying climate conditions, and thus can contribute to a better understanding and improved projections of weather extremes under climate change.

Situation Climatic Briefs

DTIC Science & Technology

1982-09-01

F-7 CHILE -ARGENTINA SOUTH OF 40 DEGREES SOUTH .... ............. .. F-13 CHILE -PERU BORDER ................. ......................... F...34SITUATION CLIMATIC BRIEF CHILE -ARGENTINA SOUTH OF 40 DEGREES SOUTH ANNUAL 1. GENERAL. The weather is generally cloudy, windy, and cold year-round...conditions can occur for 3 or 4 hours following cold frontal passage during the winter. 4. TERMINAL WEATHER. Puerto Montt, Chile . Fair. Conditions are

Multi-proxy evidence for Late Pleistocene-Holocene climatic and environmental changes in Lop-Nur, Xinjiang, Northwest China

USGS Publications Warehouse

Luo, C.; Yang, D.; Peng, Z.; Zhang, Z.; Weiguo, L.; He, J.; Zhou, C.

2008-01-01

A 10.35-m-long sediment core from the Luobei depression in Lop-Nur, Xinjiang, Northwest China, provides detailed information about environmental changes during the Late Pleistocene. The samples taken every 5 cm of the core were analyzed for 10 environmental proxies, including magnetic susceptibility, granularity, chroma, carbonate and loss on ignition (LOI), and pH value. The chronology data are provided by the uranium/thorium disequilibrium dates. The sediments of the section were deposited during the last 32000 years. The results of analysis of 10 proxies were examined using multivariate statistical analysis, and the principal components were calculated. According to the results, the Late Pleistocene sequence contains four climatic and environmental stages appearing in the cycles of cold-wet and warm-dry changes. During 10-9 ka BP, it was the earliest warm episode in the Holocene. Environmental changes in this district were restricted by global change, as suggested by the analysis of glacial-interglacial cycles. But it was different from the mutative trend of a monsoon region in East China because of its own characteristics, which was the situation of cold-wet and warm-dry climate-environment change. The candidate reason may be the uplift of the Tibet Plateau and the westerly wind circulation. ?? Science Press, Institute of Geochemistry, CAS and Springer-Verlag GmbH 2008.

Plasticity and stress tolerance override local adaptation in the responses of Mediterranean holm oak seedlings to drought and cold.

PubMed

Gimeno, Teresa E; Pías, Beatriz; Lemos-Filho, José P; Valladares, Fernando

2009-01-01

Plant populations of widely distributed species experience a broad range of environmental conditions that can be faced by phenotypic plasticity or ecotypic differentiation and local adaptation. The strategy chosen will determine a population's ability to respond to climate change. To explore this, we grew Quercus ilex (L.) seedlings from acorns collected at six selected populations from climatically contrasting localities and evaluated their response to drought and late season cold events. Maximum photosynthetic rate (A(max)), instantaneous water use efficiency (iWUE), and thermal tolerance to freeze and heat (estimated from chlorophyll fluorescence versus temperature curves) were measured in 5-month-old seedlings in control (no stress), drought (water-stressed), and cold (low suboptimal temperature) conditions. The observed responses were similar for the six populations: drought decreased A(max) and increased iWUE, and cold reduced A(max) and iWUE. All the seedlings maintained photosynthetic activity under adverse conditions (drought and cold), and rapidly increased their iWUE by closing stomata when exposed to drought. Heat and freeze tolerances were similarly high for seedlings from all the populations, and they were significantly increased by drought and cold, respectively; and were positively related to each other. Differences in seedling performance across populations were primarily induced by maternal effects mediated by seed size and to a lesser extent by idiosyncratic physiologic responses to drought and low temperatures. Tolerance to multiple stresses together with the capacity to physiologically acclimate to heat waves and cold snaps may allow Q. ilex to cope with the increasingly stressful conditions imposed by climate change. Lack of evidence of physiologic seedling adaptation to local climate may reflect opposing selection pressures to complex, multidimensional environmental conditions operating within the distribution range of this species.

Impacts of Climate Change on Stream Temperatures in the Clearwater River, Idaho

NASA Astrophysics Data System (ADS)

Yearsley, J. R.; Chegwidden, O.; Nijssen, B.

2016-12-01

Dworshak Dam in northern Idaho impounds the waters of the North Fork of the Clearwater River, creating a reservoir of approximately 4.278 km3 at full pool elevation. The dam's primary purpose is for flood control and hydroelectric power generation. It also provides important water quality benefits by releasing cold water into the Clearwater River during the summer when conditions become critical for migrating endangered species of salmon. Changes in the climate may have an impact on the ability of Dworshak Dam and Reservoir to provide these benefits. To investigate the potential for extreme outcomes that would limit cold water releases from Dworshak Reservoir and compromise the fishery, we implemented a system of hydrologic and water temperature models that simulate daily-averaged water temperatures in both the riverine and reservoir environments. We used the macroscale hydrologic model, VIC, to simulate land surface water and energy fluxes, the one-dimensional, time-dependent stream temperature model, RBM, to simulate river temperatures and a modified version of CEQUAL-W2 to simulate water temperatures in Dworshak Reservoir. A long-term hydrologically based gridded data set of meteorological forcing provided the input for comparing model results with available observations of flow and water temperature. For purposes of investigating the impacts of climate change, we used the results from ten of the most recent Climate Model Intercomparison Project (CMIP5) climate change models scenarios in conjunction with the estimates of anthropogenic inputs of climate change gases from two representative concentration pathways (RCP). We compared the simulated results associated with a range of outcomes at critical river locations from the climate scenarios with existing conditions assuming that the reservoir would be operated under a rule curve based on the average reservoir elevation for the period 2006-2015 rule curve and for power demands represented by that same period.

Hotter nests produce hatchling lizards with lower thermal tolerance.

PubMed

Dayananda, Buddhi; Murray, Brad R; Webb, Jonathan K

2017-06-15

In many regions, the frequency and duration of summer heatwaves is predicted to increase in future. Hotter summers could result in higher temperatures inside lizard nests, potentially exposing embryos to thermally stressful conditions during development. Potentially, developmentally plastic shifts in thermal tolerance could allow lizards to adapt to climate warming. To determine how higher nest temperatures affect the thermal tolerance of hatchling geckos, we incubated eggs of the rock-dwelling velvet gecko, Amalosia lesueurii , at two fluctuating temperature regimes to mimic current nest temperatures (mean 23.2°C, range 10-33°C, 'cold') and future nest temperatures (mean 27.0°C, range 14-37°C, 'hot'). Hatchlings from the hot incubation group hatched 27 days earlier and had a lower critical thermal maximum (CT max 38.7°C) and a higher critical thermal minimum (CT min 6.2°C) than hatchlings from cold incubation group (40.2 and 5.7°C, respectively). In the field, hatchlings typically settle under rocks near communal nests. During the hatching period, rock temperatures ranged from 13 to 59°C, and regularly exceeded the CT max of both hot- and cold-incubated hatchlings. Because rock temperatures were so high, the heat tolerance of lizards had little effect on their ability to exploit rocks as retreat sites. Instead, the timing of hatching dictated whether lizards could exploit rocks as retreat sites; that is, cold-incubated lizards that hatched later encountered less thermally stressful environments than earlier hatching hot-incubated lizards. In conclusion, we found no evidence that CT max can shift upwards in response to higher incubation temperatures, suggesting that hotter summers may increase the vulnerability of lizards to climate warming. © 2017. Published by The Company of Biologists Ltd.

Effects of chronic environmental cold on growth, health, and select metabolic and immunologic responses of preruminant calves.

PubMed

Nonnecke, B J; Foote, M R; Miller, B L; Fowler, M; Johnson, T E; Horst, R L

2009-12-01

The physiological response of the preruminant calf to sustained exposure to moderate cold has not been studied extensively. Effects of cold on growth performance and health of preruminant calves as well as functional measures of energy metabolism, fat-soluble vitamin, and immune responsiveness were evaluated in the present study. Calves, 3 to 10 d of age, were assigned randomly to cold (n = 14) or warm (n = 15) indoor environments. Temperatures in the cold environment averaged 4.7 degrees C during the study. Frequent wetting of the environment and the calves was used to augment effects of the cold environment. Temperatures in the warm environment averaged 15.5 degrees C during the study. There was no attempt to increase the humidity in the warm environment. Preventative medications or vaccinations that might influence disease resistance were not administered. Nonmedicated milk replacer (20% crude protein and 20% fat fed at 0.45 kg/d) and a nonmedicated starter grain fed ad libitum were fed to all calves. Relative humidity was, on average, almost 10% higher in the cold environment. Warm-environment calves were moderately healthier (i.e., lower respiratory scores) and required less antibiotics. Scour scores, days scouring, and electrolyte costs, however, were unaffected by environmental temperature. Growth rates were comparable in warm and cold environments, although cold-environment calves consumed more starter grain and had lower blood glucose and higher blood nonesterified fatty acid concentrations. The nonesterified fatty acid and glucose values for cold-stressed calves, however, did not differ sufficiently from normal values to categorize these calves as being in a state of negative-energy balance. Levels of fat-soluble vitamin, antibody, tumor necrosis factor-alpha, and haptoglobin were unaffected by sustained exposure to moderate cold. These results support the contention that successful adaptation of the dairy calf to cold is dependent upon the availability of adequate nutrition.

Effects of warm and cold climate conditions on capelin (Mallotus villosus) and Pacific herring (Clupea pallasii) in the eastern Bering Sea

NASA Astrophysics Data System (ADS)

Andrews, Alexander G.; Strasburger, Wesley W.; Farley, Edward V.; Murphy, James M.; Coyle, Kenneth O.

2016-12-01

Climate warming has impacted the southern extent of sea ice in the eastern Bering Sea (EBS) ecosystem, leading to many changes in ocean conditions and food webs there. We explore how these changes have affected two key forage fish species, capelin (Mallotus villosus) and Pacific herring (Clupea pallasii), examining the effects of climate change on this commercially important ecosystem in the EBS. Catch per unit effort (CPUE) data from surface trawls, size, and diet of capelin and Pacific herring were collected during a series of warm and cold years by fisheries oceanographic surveys conducted from mid-August to early October 2003 through 2011. Overall, mean CPUE for both species was higher in the northeastern Bering Sea [NEBS; capelin=1.2 kg/km2 (warm) and 40.0 kg/km2 (cold); herring=141.1 kg/km2 (warm) and 132.4 kg/km2 (cold)] relative to the southeastern Bering Sea [SEBS; capelin=0.2 kg/km2 (warm) and 5.8 kg/km2 (cold); herring=15.8 kg/km2 (warm) and 24.5 kg/km2 (cold)], irrespective of temperature conditions. Capelin mean CPUE was significantly lower during warm years than during cold years [p<0.001; 0.6 kg/km2 (warm), 19.0 kg/km2 (cold)]. Pacific herring mean CPUE was less variable between warm and cold years [p<0.001; 63.8 kg/km2 (warm), 66.2 kg/km2 (cold)], but was still significantly less during warm years than cold. Capelin and herring lengths remained relatively constant between climate periods. Capelin lengths were similar among oceanographic domains [104 mm (South Inner domain), 112 mm (South Middle domain), 107 mm (North Inner domain), and 104 mm (North Middle domain)], while herring were larger in domains further offshore [123 mm (South Inner domain), 232 mm (South Middle domain), 260 mm (South Outer domain), 129 mm (North Inner domain), and 198 mm (North Middle domain)]. Diets for both species were significantly different between climate periods. Large crustacean prey comprised a higher proportion of the diets in most regions during cold years. Age-0 walleye pollock (Gadus chalcogrammus) contributed >60% to the diets of Pacific herring in southern Middle Domain and >30% in the northern Middle domain during warm years. A switch to less energetic prey for these forage fishes during warm years may have implications for fitness and future recruitment. The shifts in the distribution and lower biomass of capelin in the EBS during warm years could lead to disruptions in energy pathways in this complex marine ecosystem.

Environmental factors, immune changes and respiratory diseases in troops during military activities.

PubMed

Korzeniewski, Krzysztof; Nitsch-Osuch, Aneta; Chciałowski, Andrzej; Korsak, Jolanta

2013-06-01

Combat operations in contemporary theaters of war, as well as combat training, are carried out in all parts of the world, typically in a harsh environment. Specific environmental conditions, such as heat, cold, high-altitudes, desert climates, as well as chemical and biological pollution of both the atmosphere and soil, together with over-exertion, food restrictions, sleep deprivation, and psychological stress can all result in changes in the immune system and the occurrence of associated diseases. Respiratory diseases are one of the most common health problems among military personnel participating in combat training or deployed to operations in areas characterized by difficult climatic and sanitary conditions. They are, therefore, one of the main reasons for military personnel requiring ambulant and hospital treatment. The aim of the study was to discuss the influence of environmental factors and the conditions in which active duty is performed on changes in the immune system and the occurrence of respiratory tract diseases in a military environment. Copyright © 2013 Elsevier B.V. All rights reserved.

Know your limits? Climate extremes impact the range of Scots pine in unexpected places

PubMed Central

Julio Camarero, J.; Gazol, Antonio; Sancho-Benages, Santiago; Sangüesa-Barreda, Gabriel

2015-01-01

Background and Aims Although extreme climatic events such as drought are known to modify forest dynamics by triggering tree dieback, the impact of extreme cold events, especially at the low-latitude margin (‘rear edge’) of species distributional ranges, has received little attention. The aim of this study was to examine the impact of one such extreme cold event on a population of Scots pine (Pinus sylvestris) along the species’ European southern rear-edge range limit and to determine how such events can be incorporated into species distribution models (SDMs). Methods A combination of dendrochronology and field observation was used to quantify how an extreme cold event in 2001 in eastern Spain affected growth, needle loss and mortality of Scots pine. Long-term European climatic data sets were used to contextualize the severity of the 2001 event, and an SDM for Scots pine in Europe was used to predict climatic range limits. Key Results The 2001 winter reached record minimum temperatures (equivalent to the maximum European-wide diurnal ranges) and, for trees already stressed by a preceding dry summer and autumn, this caused dieback and large-scale mortality. Needle loss and mortality were particularly evident in south-facing sites, where post-event recovery was greatly reduced. The SDM predicted European Scots pine distribution mainly on the basis of responses to maximum and minimum monthly temperatures, but in comparison with this the observed effects of the 2001 cold event at the southerly edge of the range limit were unforeseen. Conclusions The results suggest that in order to better forecast how anthropogenic climate change might affect future forest distributions, distribution modelling techniques such as SDMs must incorporate climatic extremes. For Scots pine, this study shows that the effects of cold extremes should be included across the entire distribution margin, including the southern ‘rear edge’, in order to avoid biased predictions based solely on warmer climatic scenarios. PMID:26292992

Transcriptional profiles of the annual growth cycle in Populus deltoides.

PubMed

Park, Sunchung; Keathley, Daniel E; Han, Kyung-Hwan

2008-03-01

Cycling between vegetative growth and dormancy is an important adaptive mechanism in temperate woody plants. To gain insights into the underlying molecular mechanisms, we carried out global transcription analyses on stem samples from poplar (Populus deltoides Bartr. ex Marsh.) trees grown in the field and in controlled environments. Among seasonal changes in the transcriptome, up-regulation of defense-related genes predominated in early winter, whereas signaling-related genes were up-regulated during late winter. Cluster analysis of the differentially expressed genes showed that plants regulated seasonal growth by integrating environmental factors with development. Short day lengths induced some cold-associated genes without concomitant low temperature exposure, and enhanced the expression of some genes when combined with low temperature exposure. These mechanisms appear to maintain closer synchrony between cold hardiness and climate than would be achieved through responses to temperature alone.

The Universal Thermal Climate Index UTCI compared to ergonomics standards for assessing the thermal environment.

PubMed

Bröde, Peter; Błazejczyk, Krzysztof; Fiala, Dusan; Havenith, George; Holmér, Ingvar; Jendritzky, Gerd; Kuklane, Kalev; Kampmann, Bernhard

2013-01-01

The growing need for valid assessment procedures of the outdoor thermal environment in the fields of public weather services, public health systems, urban planning, tourism & recreation and climate impact research raised the idea to develop the Universal Thermal Climate Index UTCI based on the most recent scientific progress both in thermo-physiology and in heat exchange theory. Following extensive validation of accessible models of human thermoregulation, the advanced multi-node 'Fiala' model was selected to form the basis of UTCI. This model was coupled with an adaptive clothing model which considers clothing habits by the general urban population and behavioral changes in clothing insulation related to actual environmental temperature. UTCI was developed conceptually as an equivalent temperature. Thus, for any combination of air temperature, wind, radiation, and humidity, UTCI is defined as the air temperature in the reference condition which would elicit the same dynamic response of the physiological model. This review analyses the sensitivity of UTCI to humidity and radiation in the heat and to wind in the cold and compares the results with observational studies and internationally standardized assessment procedures. The capabilities, restrictions and potential future extensions of UTCI are discussed.

Temperature drives global patterns in forest biomass distribution in leaves, stems, and roots.

PubMed

Reich, Peter B; Luo, Yunjian; Bradford, John B; Poorter, Hendrik; Perry, Charles H; Oleksyn, Jacek

2014-09-23

Whether the fraction of total forest biomass distributed in roots, stems, or leaves varies systematically across geographic gradients remains unknown despite its importance for understanding forest ecology and modeling global carbon cycles. It has been hypothesized that plants should maintain proportionally more biomass in the organ that acquires the most limiting resource. Accordingly, we hypothesize greater biomass distribution in roots and less in stems and foliage in increasingly arid climates and in colder environments at high latitudes. Such a strategy would increase uptake of soil water in dry conditions and of soil nutrients in cold soils, where they are at low supply and are less mobile. We use a large global biomass dataset (>6,200 forests from 61 countries, across a 40 °C gradient in mean annual temperature) to address these questions. Climate metrics involving temperature were better predictors of biomass partitioning than those involving moisture availability, because, surprisingly, fractional distribution of biomass to roots or foliage was unrelated to aridity. In contrast, in increasingly cold climates, the proportion of total forest biomass in roots was greater and in foliage was smaller for both angiosperm and gymnosperm forests. These findings support hypotheses about adaptive strategies of forest trees to temperature and provide biogeographically explicit relationships to improve ecosystem and earth system models. They also will allow, for the first time to our knowledge, representations of root carbon pools that consider biogeographic differences, which are useful for quantifying whole-ecosystem carbon stocks and cycles and for assessing the impact of climate change on forest carbon dynamics.

Temperature drives global patterns in forest biomass distribution in leaves, stems, and roots

PubMed Central

Reich, Peter B.; Luo, Yunjian; Bradford, John B.; Poorter, Hendrik; Perry, Charles H.; Oleksyn, Jacek

2014-01-01

Whether the fraction of total forest biomass distributed in roots, stems, or leaves varies systematically across geographic gradients remains unknown despite its importance for understanding forest ecology and modeling global carbon cycles. It has been hypothesized that plants should maintain proportionally more biomass in the organ that acquires the most limiting resource. Accordingly, we hypothesize greater biomass distribution in roots and less in stems and foliage in increasingly arid climates and in colder environments at high latitudes. Such a strategy would increase uptake of soil water in dry conditions and of soil nutrients in cold soils, where they are at low supply and are less mobile. We use a large global biomass dataset (>6,200 forests from 61 countries, across a 40 °C gradient in mean annual temperature) to address these questions. Climate metrics involving temperature were better predictors of biomass partitioning than those involving moisture availability, because, surprisingly, fractional distribution of biomass to roots or foliage was unrelated to aridity. In contrast, in increasingly cold climates, the proportion of total forest biomass in roots was greater and in foliage was smaller for both angiosperm and gymnosperm forests. These findings support hypotheses about adaptive strategies of forest trees to temperature and provide biogeographically explicit relationships to improve ecosystem and earth system models. They also will allow, for the first time to our knowledge, representations of root carbon pools that consider biogeographic differences, which are useful for quantifying whole-ecosystem carbon stocks and cycles and for assessing the impact of climate change on forest carbon dynamics. PMID:25225412

Temperature drives global patterns in forest biomass distribution in leaves, stems, and roots

USGS Publications Warehouse

Reich, Peter B.; Lou, Yunjian; Bradford, John B.; Poorter, Hendrik; Perry, Charles H.; Oleksyn, Jacek

2014-01-01

Whether the fraction of total forest biomass distributed in roots, stems, or leaves varies systematically across geographic gradients remains unknown despite its importance for understanding forest ecology and modeling global carbon cycles. It has been hypothesized that plants should maintain proportionally more biomass in the organ that acquires the most limiting resource. Accordingly, we hypothesize greater biomass distribution in roots and less in stems and foliage in increasingly arid climates and in colder environments at high latitudes. Such a strategy would increase uptake of soil water in dry conditions and of soil nutrients in cold soils, where they are at low supply and are less mobile. We use a large global biomass dataset (>6,200 forests from 61 countries, across a 40 °C gradient in mean annual temperature) to address these questions. Climate metrics involving temperature were better predictors of biomass partitioning than those involving moisture availability, because, surprisingly, fractional distribution of biomass to roots or foliage was unrelated to aridity. In contrast, in increasingly cold climates, the proportion of total forest biomass in roots was greater and in foliage was smaller for both angiosperm and gymnosperm forests. These findings support hypotheses about adaptive strategies of forest trees to temperature and provide biogeographically explicit relationships to improve ecosystem and earth system models. They also will allow, for the first time to our knowledge, representations of root carbon pools that consider biogeographic differences, which are useful for quantifying whole-ecosystem carbon stocks and cycles and for assessing the impact of climate change on forest carbon dynamics.

The thermal mismatch hypothesis explains host susceptibility to an emerging infectious disease.

PubMed

Cohen, Jeremy M; Venesky, Matthew D; Sauer, Erin L; Civitello, David J; McMahon, Taegan A; Roznik, Elizabeth A; Rohr, Jason R

2017-02-01

Parasites typically have broader thermal limits than hosts, so large performance gaps between pathogens and their cold- and warm-adapted hosts should occur at relatively warm and cold temperatures, respectively. We tested this thermal mismatch hypothesis by quantifying the temperature-dependent susceptibility of cold- and warm-adapted amphibian species to the fungal pathogen Batrachochytrium dendrobatidis (Bd) using laboratory experiments and field prevalence estimates from 15 410 individuals in 598 populations. In both the laboratory and field, we found that the greatest susceptibility of cold- and warm-adapted hosts occurred at relatively warm and cool temperatures, respectively, providing support for the thermal mismatch hypothesis. Our results suggest that as climate change shifts hosts away from their optimal temperatures, the probability of increased host susceptibility to infectious disease might increase, but the effect will depend on the host species and the direction of the climate shift. Our findings help explain the tremendous variation in species responses to Bd across climates and spatial, temporal and species-level variation in disease outbreaks associated with extreme weather events that are becoming more common with climate change. © 2017 John Wiley & Sons Ltd/CNRS.

Cold climate specialization: adaptive covariation between metabolic rate and thermoregulation in pregnant vipers.

PubMed

Lourdais, Olivier; Guillon, Michaël; Denardo, Dale; Blouin-Demers, Gabriel

2013-07-02

We compared thermoregulatory strategies during pregnancy in two congeneric viperid snakes (Vipera berus and Vipera aspis) with parapatric geographic ranges. V. berus is a boreal specialist with the largest known distribution among terrestrial snakes while V. aspis is a south-European species. Despite contrasted climatic affinities, the two species displayed identical thermal preferences (Tset) in a laboratory thermal gradient. Under identical natural conditions, however, V. berus was capable of maintaining Tset for longer periods, especially when the weather was constraining. Consistent with the metabolic cold adaptation hypothesis, V. berus displayed higher standard metabolic rate at all temperatures considered. We used the thermal dependence of metabolic rate to calculate daily metabolic profiles from body temperature under natural conditions. The boreal specialist experienced higher daily metabolic rate and minimized gestation duration chiefly because of differences in the metabolic reaction norms, but also superior thermoregulatory efficiency. Under cold climates, thermal constraints should make precise thermoregulation costly. However, a shift in the metabolic reaction norm may compensate for thermal constraints and modify the cost-benefit balance of thermoregulation. Covariation between metabolic rate and thermoregulation efficiency is likely an important adaptation to cold climates. Copyright © 2013 Elsevier Inc. All rights reserved.

The evolution of high summit metabolism and cold tolerance in birds and its impact on present-day distributions.

PubMed

Swanson, David L; Garland, Theodore

2009-01-01

Summit metabolic rate (M(sum), maximum cold-induced metabolic rate) is positively correlated with cold tolerance in birds, suggesting that high M(sum) is important for residency in cold climates. However, the phylogenetic distribution of high M(sum) among birds and the impact of its evolution on current distributions are not well understood. Two potential adaptive hypotheses might explain the phylogenetic distribution of high M(sum) among birds. The cold adaptation hypothesis contends that species wintering in cold climates should have higher M(sum) than species wintering in warmer climates. The flight adaptation hypothesis suggests that volant birds might be capable of generating high M(sum) as a byproduct of their muscular capacity for flight; thus, variation in M(sum) should be associated with capacity for sustained flight, one indicator of which is migration. We collected M(sum) data from the literature for 44 bird species and conducted both conventional and phylogenetically informed statistical analyses to examine the predictors of M(sum) variation. Significant phylogenetic signal was present for log body mass, log mass-adjusted M(sum), and average temperature in the winter range. In multiple regression models, log body mass, winter temperature, and clade were significant predictors of log M(sum). These results are consistent with a role for climate in determining M(sum) in birds, but also indicate that phylogenetic signal remains even after accounting for associations indicative of adaptation to winter temperature. Migratory strategy was never a significant predictor of log M(sum) in multiple regressions, a result that is not consistent with the flight adaptation hypothesis.

Paleoecological evidence for abrupt cold reversals during peak Holocene warmth on Baffin Island, Arctic Canada

NASA Astrophysics Data System (ADS)

Axford, Yarrow; Briner, Jason P.; Miller, Gifford H.; Francis, Donna R.

2009-03-01

A continuous record of insect (Chironomidae) remains preserved in lake sediments is used to infer temperature changes at a small lake in Arctic Canada through the Holocene. Early Holocene summers at the study site were characterized by more thermophilous assemblages and warmer inferred temperatures than today, presumably in response to the positive anomaly in Northern Hemisphere summer insolation. Peak early Holocene warmth was interrupted by two cold reversals between 9.5 and 8 cal ka BP, during which multiple cold-stenothermous chironomid taxa appeared in the lake. The earlier reversal appears to correlate with widespread climate anomalies around 9.2 cal ka BP; the age of the younger reversal is equivocal but it may correlate with the 8.2 cal ka BP cold event documented elsewhere. Widespread, abrupt climate shifts in the early Holocene illustrate the susceptibility of the climate system to perturbations, even during periods of enhanced warmth in the Northern Hemisphere.

Cold adaptation recorded in tree rings highlights risks associated with climate change and assisted migration.

PubMed

Montwé, David; Isaac-Renton, Miriam; Hamann, Andreas; Spiecker, Heinrich

2018-04-23

With lengthening growing seasons but increased temperature variability under climate change, frost damage to plants may remain a risk and could be exacerbated by poleward planting of warm-adapted seed sources. Here, we study cold adaptation of tree populations in a wide-ranging coniferous species in western North America to inform limits to seed transfer. Using tree-ring signatures of cold damage from common garden trials designed to study genetic population differentiation, we find opposing geographic clines for spring frost and fall frost damage. Provenances from northern regions are sensitive to spring frosts, while the more productive provenances from central and southern regions are more susceptible to fall frosts. Transferring the southern, warm-adapted genotypes northward causes a significant loss of growth and a permanent rank change after a spring frost event. We conclude that cold adaptation should remain an important consideration when implementing seed transfers designed to mitigate harmful effects of climate change.

Climate and Cryosphere (CliC) Project and its Interest in Arctic Hydrology Research

NASA Astrophysics Data System (ADS)

Yang, D.; Prowse, T. D.; Steffen, K.; Ryabinin, V.

2009-12-01

The cryosphere is an important and dynamic component of the global climate system. The global cryosphere is changing rapidly, with changes in the Polar Regions receiving particular attention during the International Polar Year 2007-2008. The Climate and Cryosphere (CliC) Project is a core project of the World Climate Research Programme (WCRP) and is co-sponsored by WCRP, SCAR (Scientific Committee for Antarctic Research) and IASC (International Committee for Antarctic Research). The principal goal of CliC is to assess and quantify the impacts that climatic variability and change have on components of the cryosphere and the consequences of these impacts for the climate system. To achieve its objectives, CliC coordinates international and regional projects, partners with other organizations in joint initiatives, and organizes panels and working groups to lead and coordinate advanced research aimed at closing identified gaps in scientific knowledge about climate and cryosphere. The terrestrial cryosphere includes land areas where snow cover, lake- and river-ice, glaciers and ice caps, permafrost and seasonally frozen ground and solid precipitation occur. The main task of this theme is to improve estimates and quantify the uncertainty of water balance and related energy flux components in cold climate regions. This includes precipitation (both solid and liquid) distribution, properties of snow, snow melt, evapotranspiration, sublimation, water movement through frozen and unfrozen ground, water storage in watersheds, river- and lake-ice properties and processes, and river runoff. The focus of this theme includes two specific issues: the role of permafrost and frozen ground in the carbon balance, and precipitation in cold climates. Hydrological studies of cold regions will provide a key contribution to the new theme crosscut, which focuses on the cryospheric input to the freshwater balance of the Arctic. This presentation will provide an overview and update of recent developments of cold region hydrometeorology research activities and future challenges in arctic hydrology and climate change investigations.

Temperature is better than precipitation as a predictor of plant community assembly across a dryland region

USGS Publications Warehouse

Butterfield, Bradley J.; Munson, Seth M.

2016-01-01

QuestionHow closely do plant communities track climate? Research suggests that plant species converge toward similar environmental tolerances relative to the environments that they experience. Whether these patterns apply to severe environments or scale up to plant community-level patterns of relative climatic tolerances is poorly understood. Using estimates of species' climatic tolerances acquired from occurrence records, we determined the contributions of individual species' climatic niche breadths and environmental filtering to the relationships between community-average climatic tolerances and the local climates experienced by those communities.LocationSouthwestern United States drylands.MethodsInterspecific variation in niche breadth was assessed as a function of species' climatic optima (median climatic niche value). The relationships between climatic optima and tolerances were used as null expectations for the relationship between abundance-weighted mean climatic tolerances of communities and the local climate of that community. Deviations from this null expectation indicate that species with greater or lesser climatic tolerances are favoured relative to co-occurring species. The intensity of environmental filtering was estimated by comparing the range of climatic tolerances within each community to a null distribution generated from a random assembly algorithm.ResultsThe temperature niches of species were consistently symmetrical and of similar breadths, regardless of their temperature optima. In contrast, precipitation niches were skewed toward wetter conditions, and niche breadth increased with increasing precipitation optima. At the community level, relationships with climate were much stronger for temperature than for precipitation. Furthermore, cold and heat were stronger assembly filters than drought or precipitation, with the intensity of environmental filtering increasing at both ends of climatic gradients. Community-average climatic tolerances did deviate significantly from null expectations, indicating that species with higher or lower relative climatic tolerances were favoured under certain conditions.ConclusionsDespite strong water limitation of plant performance in dryland ecosystems, communities tracked variation in temperature much more closely, intimating strong responses to anticipated temperature increases. Furthermore, abundance distributions were biased toward species with higher or lower relative climatic tolerances under different climatic conditions, but predictably so, indicating the need for assembly models that include processes other than simple environmental filtering.

Research on trend of warm-humid climate in Central Asia

NASA Astrophysics Data System (ADS)

Gong, Zhi; Peng, Dailiang; Wen, Jingyi; Cai, Zhanqing; Wang, Tiantian; Hu, Yuekai; Ma, Yaxin; Xu, Junfeng

2017-07-01

Central Asia is a typical arid area, which is sensitive and vulnerable part of climate changes, at the same time, Central Asia is the Silk Road Economic Belt of the core district, the warm-humid climate change will affect the production and economic development of neighboring countries. The average annual precipitation, average anneal temperature and evapotranspiration are the important indexes to weigh the climate change. In this paper, the annual precipitation, annual average temperature and evapotranspiration data of every pixel point in Central Asia are analyzed by using long-time series remote sensing data to analyze the trend of warm and humid conditions. Finally, using the model to analyzed the distribution of warm-dry trend, the warm-wet trend, the cold-dry trend and the cold-wet trend in Central Asia and Xinjiang area. The results showed that most of the regions of Central Asia were warm-humid and warm-dry trends, but only a small number of regions showed warm-dry and cold-dry trends. It is of great significance to study the climatic change discipline and guarantee the ecological safety and improve the ability to cope with climate change in the region. It also provide scientific basis for the formulation of regional climate change program. The first section in your paper

Geologic Tests for Snowmelt Runoff on Early Mars

NASA Astrophysics Data System (ADS)

Kite, E. S.; Sneed, J.; Mayer, D. P.

2017-12-01

Data from the Curiosity rover have sharpened the question: was Early Mars climate warm enough for rainfall, or was the climate cold? The hypothesis of a cold (snow-and-ice melt) climate on Early Mars can be tested using runoff production. Runoff production cannot exceed snowmelt rate in a cold climate. Therefore, high runoff production would rule out cold conditions, and would suggest rain (or catastrophic melting of snow). How can runoff production be reliably measured? To constrain runoff production, the lead author is measuring paleochannel widths and meander wavelengths for Early Mars watersheds with well-defined drainage area. The measurement method is the same as in Kite et al., EPSL, 2015. >250 channel-width measurements and 89 meander wavelength measurements are included, representing 158 drainage areas. The catalog emphasizes better-preserved (post-Noachian) paleochannels, but includes a re-survey of previously-reported paleochannel width and wavelength measurement sites. Channel widths and wavelengths are a proxy for paleodischarge. Discharge (m3/s) can be divided by drainage area (m2) to obtain a lower bound on runoff-production (mm/hr). If runoff production >(1-3) mm/hr, then a seasonal melting snow-and-ice climate is strongly disfavored. However, high runoff production would be consistent with rainfall. Initial results will be reported at the conference. The figure shows the locations of measurement sites for Early Mars channel width (black) and meander wavelength (red).

Body proportions of circumpolar peoples as evidenced from skeletal data: Ipiutak and Tigara (Point Hope) versus Kodiak Island Inuit.

PubMed

Holliday, Trenton W; Hilton, Charles E

2010-06-01

Given the well-documented fact that human body proportions covary with climate (presumably due to the action of selection), one would expect that the Ipiutak and Tigara Inuit samples from Point Hope, Alaska, would be characterized by an extremely cold-adapted body shape. Comparison of the Point Hope Inuit samples to a large (n > 900) sample of European and European-derived, African and African-derived, and Native American skeletons (including Koniag Inuit from Kodiak Island, Alaska) confirms that the Point Hope Inuit evince a cold-adapted body form, but analyses also reveal some unexpected results. For example, one might suspect that the Point Hope samples would show a more cold-adapted body form than the Koniag, given their more extreme environment, but this is not the case. Additionally, univariate analyses seldom show the Inuit samples to be more cold-adapted in body shape than Europeans, and multivariate cluster analyses that include a myriad of body shape variables such as femoral head diameter, bi-iliac breadth, and limb segment lengths fail to effectively separate the Inuit samples from Europeans. In fact, in terms of body shape, the European and the Inuit samples tend to be cold-adapted and tend to be separated in multivariate space from the more tropically adapted Africans, especially those groups from south of the Sahara. Copyright 2009 Wiley-Liss, Inc.

Teaching in a Cold Environment.

ERIC Educational Resources Information Center

Ewert, Alan

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

Relating Regional Arctic Sea Ice and climate extremes over Europe

NASA Astrophysics Data System (ADS)

Ionita-Scholz, Monica; Grosfeld, Klaus; Lohmann, Gerrit; Scholz, Patrick

2016-04-01

The potential increase of temperature extremes under climate change is a major threat to society, as temperature extremes have a deep impact on environment, hydrology, agriculture, society and economy. Hence, the analysis of the mechanisms underlying their occurrence, including their relationships with the large-scale atmospheric circulation and sea ice concentration, is of major importance. At the same time, the decline in Arctic sea ice cover during the last 30 years has been widely documented and it is clear that this change is having profound impacts at regional as well as planetary scale. As such, this study aims to investigate the relation between the autumn regional sea ice concentration variability and cold winters in Europe, as identified by the numbers of cold nights (TN10p), cold days (TX10p), ice days (ID) and consecutive frost days (CFD). We analyze the relationship between Arctic sea ice variation in autumn (September-October-November) averaged over eight different Arctic regions (Barents/Kara Seas, Beaufort Sea, Chukchi/Bering Seas, Central Arctic, Greenland Sea, Labrador Sea/Baffin Bay, Laptev/East Siberian Seas and Northern Hemisphere) and variations in atmospheric circulation and climate extreme indices in the following winter season over Europe using composite map analysis. Based on the composite map analysis it is shown that the response of the winter extreme temperatures over Europe is highly correlated/connected to changes in Arctic sea ice variability. However, this signal is not symmetrical for the case of high and low sea ice years. Moreover, the response of temperatures extreme over Europe to sea ice variability over the different Arctic regions differs substantially. The regions which have the strongest impact on the extreme winter temperature over Europe are: Barents/Kara Seas, Beaufort Sea, Central Arctic and the Northern Hemisphere. For the years of high sea ice concentration in the Barents/Kara Seas there is a reduction in the number of cold nights, cold days, ice days and consecutive frost days over the western part of Europe. In the opposite case of low sea ice concentration over the Barents/Kara Seas an increase of up to 8 days/winter of cold nights and days is observed over the whole Europe and an increase of up to 4 days/winter in the number of ID and CFD is observed over the same regions. The cold winters over Europe (low sea ice years) are associated with anomalous anticyclone and the downstream development of a mid-latitude trough, which in turn favours the advection of cold air from the north, providing favourable conditions for severe winters over Europe. We suggest that these results can help to improve the seasonal predictions of winter extreme events over Europe. Due to the non-linear response to high vs. low sea ice years, the skill of the predictions might depend on the sign and amplitude of the anomalies.

Climate and environmental triggers of acute myocardial infarction.

PubMed

Claeys, Marc J; Rajagopalan, Sanjay; Nawrot, Tim S; Brook, Robert D

2017-04-01

Over the past few decades, a growing body of epidemiological and clinical evidence has led to heightened concerns about the potential short- and long-term deleterious effects of the environment on cardiovascular health, including the risk for acute myocardial infarction (AMI). This review highlights the increased risk of AMI caused by exposure to air pollution and cold temperatures. These factors should be considered modifiable risk factors in the prevention of cardiovascular disease. The current body of knowledge about the biological mechanisms linking environmental changes to atherothrombotic events and the impact of climate change on cardiovascular health are discussed. Finally, recommendations for prevention and public policy are presented. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

Interactions between demography and environmental effects are important determinants of population dynamics

PubMed Central

Gamelon, Marlène; Grøtan, Vidar; Nilsson, Anna L. K.; Engen, Steinar; Hurrell, James W.; Jerstad, Kurt; Phillips, Adam S.; Røstad, Ole W.; Slagsvold, Tore; Walseng, Bjørn; Stenseth, Nils C.; Sæther, Bernt-Erik

2017-01-01

Climate change will affect the population dynamics of many species, yet the consequences for the long-term persistence of populations are poorly understood. A major reason for this is that density-dependent feedback effects caused by fluctuations in population size are considered independent of stochastic variation in the environment. We show that an interplay between winter temperature and population density can influence the persistence of a small passerine population under global warming. Although warmer winters favor an increased mean population size, density-dependent feedback can cause the local population to be less buffered against occasional poor environmental conditions (cold winters). This shows that it is essential to go beyond the population size and explore climate effects on the full dynamics to elaborate targeted management actions. PMID:28164157

Large extents of intensive land use limit community reorganization during climate warming.

PubMed

Oliver, Tom H; Gillings, Simon; Pearce-Higgins, James W; Brereton, Tom; Crick, Humphrey Q P; Duffield, Simon J; Morecroft, Michael D; Roy, David B

2017-06-01

Climate change is increasingly altering the composition of ecological communities, in combination with other environmental pressures such as high-intensity land use. Pressures are expected to interact in their effects, but the extent to which intensive human land use constrains community responses to climate change is currently unclear. A generic indicator of climate change impact, the community temperature index (CTI), has previously been used to suggest that both bird and butterflies are successfully 'tracking' climate change. Here, we assessed community changes at over 600 English bird or butterfly monitoring sites over three decades and tested how the surrounding land has influenced these changes. We partitioned community changes into warm- and cold-associated assemblages and found that English bird communities have not reorganized successfully in response to climate change. CTI increases for birds are primarily attributable to the loss of cold-associated species, whilst for butterflies, warm-associated species have tended to increase. Importantly, the area of intensively managed land use around monitoring sites appears to influence these community changes, with large extents of intensively managed land limiting 'adaptive' community reorganization in response to climate change. Specifically, high-intensity land use appears to exacerbate declines in cold-adapted bird and butterfly species, and prevent increases in warm-associated birds. This has broad implications for managing landscapes to promote climate change adaptation. © 2017 John Wiley & Sons Ltd.

Can animal habitat use patterns influence their vulnerability to extreme climate events? An estuarine sportfish case study.

PubMed

Boucek, Ross E; Heithaus, Michael R; Santos, Rolando; Stevens, Philip; Rehage, Jennifer S

2017-10-01

Global climate forecasts predict changes in the frequency and intensity of extreme climate events (ECEs). The capacity for specific habitat patches within a landscape to modulate stressors from extreme climate events, and animal distribution throughout habitat matrices during events, could influence the degree of population level effects following the passage of ECEs. Here, we ask (i) does the intensity of stressors of an ECE vary across a landscape? And (ii) Do habitat use patterns of a mobile species influence their vulnerability to ECEs? Specifically, we measured how extreme cold spells might interact with temporal variability in habitat use to affect populations of a tropical, estuarine-dependent large-bodied fish Common Snook, within Everglades National Park estuaries (FL US). We examined temperature variation across the estuary during cold disturbances with different degrees of severity, including an extreme cold spell. Second, we quantified Snook distribution patterns when the passage of ECEs is most likely to occur from 2012 to 2016 using passive acoustic tracking. Our results revealed spatial heterogeneity in the intensity of temperature declines during cold disturbances, with some habitats being consistently 3-5°C colder than others. Surprisingly, Snook distributions during periods of greatest risk to experience an extreme cold event varied among years. During the winters of 2013-2014 and 2014-2015 a greater proportion of Snook occurred in the colder habitats, while the winters of 2012-2013 and 2015-2016 featured more Snook observed in the warmest habitats. This study shows that Snook habitat use patterns could influence vulnerability to extreme cold events, however, whether Snook habitat use increases or decreases their vulnerability to disturbance depends on the year, creating temporally dynamic vulnerability. Faunal global change research should address the spatially explicit nature of extreme climate events and animal habitat use patterns to identify potential mechanisms that may influence population effects following these disturbances. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Developing a protocol for long-term population monitoring and habitat projections for a climate-sensitive sentinel species to track ecosystem change and species range shifts

NASA Astrophysics Data System (ADS)

Beers, A.

2016-12-01

As a response to ongoing climate change, many species have started to shift their ranges poleward and toward higher elevations and mountain environments are predicted to experience especially rapid climatic changes. Because of this, there is likely a greater risk of habitat loss and local extinctions for species at high elevations compared to species at lower elevations. Among those potentially threatened habitat specialists is the American pika (Ochotona princeps), a climate sensitive indicator of climate change effects which may already be experiencing climate driven extirpations. Pikas are considered sentinels, indicators of greater ecosystem change. Changes in their distribution speaks to changes in availability of resources they require and shifts in the environment. Pika presence is closely tied to sub-surface ice features that act as a temperature buffer and water source. Those sub-surface ice features are critical in water cycling and long-term water storage and drive downstream hydrological and ecological processes. Understanding how this species responds to climate change therefore provides a model to inform landscape level conservation and management decisions. Pikas may be particularly vulnerable in parts of Colorado, including Rocky Mountain National Park (ROMO) and the Niwot Ridge LTER (NWT), where they may face population collapse as habitat suitability and connectivity both decline in response to various possible climate change scenarios, in large part because of cold stress and declining functional connectivity. Because of their potential role as an ecosystem indicator, their risk for decline, and how limitations to their survival likely vary across their range, management groups can use place based models of habitat suitability for pikas or other sentinel species in designing long term monitoring protocols to detect ecosystem responses to climate change. In this project we used remotely sensed data, occupancy surveys, and a random tessellation stratification to design a protocol for ROMO and NWT that best suits those environments. We also demonstrate the efficacy of habitat models based on remote sensing and their potential application toward tracking ecosystem change and species range shifts.

Geographical differences in maternal basking behaviour and offspring growth rate in a climatically widespread viviparous reptile.

PubMed

Cadby, Chloé D; Jones, Susan M; Wapstra, Erik

2014-04-01

In reptiles, the thermal environment during embryonic development affects offspring phenotypic traits and potentially offspring fitness. In viviparous species, mothers can potentially manipulate the embryonic thermal environment through their basking behaviour and, thus, may be able to manipulate offspring phenotype and increase offspring fitness. One way in which mothers can maximise offspring phenotype (and thus potentially affect offspring fitness) is by fine-tuning their basking behaviour to the environment in order to buffer the embryo from deleterious developmental temperatures. In widespread species, it is unclear whether populations that have evolved under different climatic conditions will exhibit different maternal behaviours and/or thermal effects on offspring phenotype. To test this, we provided extended or reduced basking opportunity to gravid spotted skinks (Niveoscincus ocellatus) and their offspring from two populations at the climatic extremes of the species' distribution. Gravid females fine-tuned their basking behaviour to the basking opportunity, which allowed them to buffer their embryos from potentially negative thermal effects. This fine-tuning of female basking behaviour appears to have led to the expression of geographical differences in basking behaviour, with females from the cold alpine regions being more opportunistic in their basking behaviour than females from the warmer regions. However, those differences in maternal behaviour did not preclude the evolution of geographic differences in thermal effects: offspring growth varied between populations, potentially suggesting local adaptation to basking conditions. Our results demonstrate that maternal effects and phenotypic plasticity can play a significant role in allowing species to cope in changing environmental conditions, which is particularly relevant in the context of climate change.

Impact of climate change on the domestic indoor environment and associated health risks in the UK.

PubMed

Vardoulakis, Sotiris; Dimitroulopoulou, Chrysanthi; Thornes, John; Lai, Ka-Man; Taylor, Jonathon; Myers, Isabella; Heaviside, Clare; Mavrogianni, Anna; Shrubsole, Clive; Chalabi, Zaid; Davies, Michael; Wilkinson, Paul

2015-12-01

There is growing evidence that projected climate change has the potential to significantly affect public health. In the UK, much of this impact is likely to arise by amplifying existing risks related to heat exposure, flooding, and chemical and biological contamination in buildings. Identifying the health effects of climate change on the indoor environment, and risks and opportunities related to climate change adaptation and mitigation, can help protect public health. We explored a range of health risks in the domestic indoor environment related to climate change, as well as the potential health benefits and unintended harmful effects of climate change mitigation and adaptation policies in the UK housing sector. We reviewed relevant scientific literature, focusing on housing-related health effects in the UK likely to arise through either direct or indirect mechanisms of climate change or mitigation and adaptation measures in the built environment. We considered the following categories of effect: (i) indoor temperatures, (ii) indoor air quality, (iii) indoor allergens and infections, and (iv) flood damage and water contamination. Climate change may exacerbate health risks and inequalities across these categories and in a variety of ways, if adequate adaptation measures are not taken. Certain changes to the indoor environment can affect indoor air quality or promote the growth and propagation of pathogenic organisms. Measures aimed at reducing greenhouse gas emissions have the potential for ancillary public health benefits including reductions in health burdens related heat and cold, indoor exposure to air pollution derived from outdoor sources, and mould growth. However, increasing airtightness of dwellings in pursuit of energy efficiency could also have negative effects by increasing concentrations of pollutants (such as PM2.5, CO and radon) derived from indoor or ground sources, and biological contamination. These effects can largely be ameliorated by mechanical ventilation with heat recovery (MVHR) and air filtration, where such solution is feasible and when the system is properly installed, operated and maintained. Groups at high risk of these adverse health effects include the elderly (especially those living on their own), individuals with pre-existing illnesses, people living in overcrowded accommodation, and the socioeconomically deprived. A better understanding of how current and emerging building infrastructure design, construction, and materials may affect health in the context of climate change and mitigation and adaptation measures is needed in the UK and other high income countries. Long-term, energy efficient building design interventions, ensuring adequate ventilation, need to be promoted. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Effective Climate Refugia for Cold-water Fishes

NASA Astrophysics Data System (ADS)

Ebersole, J. L.; Morelli, T. L.; Torgersen, C.; Isaak, D.; Keenan, D.; Labiosa, R.; Fullerton, A.; Massie, J.

2015-12-01

Climate change threatens to create fundamental shifts in in the distributions and abundances of endothermic organisms such as cold-water salmon and trout species (salmonids). Recently published projected declines in mid-latitude salmonid distributions under future climates range from modest to severe, depending on modeling approaches, assumptions, and spatial context of analyses. Given these projected losses, increased emphasis on management for ecosystem resilience to help buffer cold-water fish populations and their habitats against climate change is emerging. Using terms such as "climate-proofing", "climate-ready", and "climate refugia", such efforts stake a claim for an adaptive, anticipatory planning response to the climate change threat. To be effective, such approaches will need to address critical uncertainties in both the physical basis for projected landscape changes in water temperature and streamflow, as well as the biological responses of organisms. Recent efforts define future potential climate refugia based on projected streamflows, air temperatures, and associated water temperature changes. These efforts reflect the relatively strong conceptual foundation for linkages between regional climate change and local hydrological responses and thermal dynamics. Yet important questions remain. Drawing on case studies throughout the Pacific Northwest, we illustrate some key uncertainties in the responses of salmonids and their habitats to altered hydro-climatic regimes currently not well addressed by physical or ecological models. Key uncertainties include biotic interactions, organismal adaptive capacity, local climate decoupling due to groundwater-surface water interactions, the influence of human engineering responses, and synergies between climatic and other stressors. These uncertainties need not delay anticipatory planning, but rather highlight the need for identification and communication of actions with high probabilities of success, and targeted research within an adaptive management framework.

Hormonal growth-promotant effects on grain-fed cattle maintained under different environments

NASA Astrophysics Data System (ADS)

Gaughan, J. B.; Kreikemeier, W. M.; Mader, T. L.

2005-07-01

Six steers (3/4 Charolais×1/4 Brahman) (mean body weight 314±27 kg) and six spayed heifers (3/5 Shorthorn×2/5 Red Angus) (mean body weight 478±30 kg) were used to determine the effects of climatic conditions and hormone growth promotants (HGP) on respiration rate (RR; breaths/min), pulse rate (beats/min), rectal temperature (RT; °C), and heat production (HP; kJ). Cattle were exposed to the following climatic conditions prior to implantation with a HGP and then again 12 days after implantation: 2 days of thermoneutral conditions (TNL) [21.9±0.9°C ambient temperature (TA) and 61.7±22.1% relative humidity (RH)] then 2 days of hot conditions [HOT; 29.2±4°C (TA) and 78.3±13.2% (RH)], then TNL for 3 days and then 2 days of cold conditions [COLD; 17.6±0.9°C (TA) and 63.4±1.8% (RH); cattle were wet during this treatment]. The HGP implants used were: estrogenic implant (E), trenbolone acetate implant (TBA), or both (ET). Both prior to and following administration of HGP, RRs were lower (P<0.05) on cold days and greater (P<0.05) on hot days compared to TNL. On hot days, RTs, were 0.62°C higher after compared to before implanting. Across all conditions, RTs were >0.5°C greater (P<0.05) for E cattle than for TBA or ET cattle. On cold days, RTs of steers were >0.8°C higher than for the heifers, while under TNL and HOT, RTs of steers were 0.2 0.35°C higher than those of heifers. Prior to implantation, HP per hour and per unit of metabolic body weight was higher (P<0.05) for cattle exposed to hot conditions, when compared to HP on cold days. After implantation, HP was greater (P<0.05) on hot days than on cold days. Under TNL, ET cattle had the lowest HP and greatest feed intake. On hot days, E cattle had the lowest HP, and the highest RT; therefore, if the potential exists for cattle death from heat episodes, the use of either TBA or ET may be preferred. Under cold conditions HP was similar among implant groups.

Night ventilation control strategies in office buildings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Zhaojun; Yi, Lingli; Gao, Fusheng

2009-10-15

In moderate climates night ventilation is an effective and energy-efficient approach to improve the indoor thermal environment for office buildings during the summer months, especially for heavyweight construction. However, is night ventilation a suitable strategy for office buildings with lightweight construction located in cold climates? In order to answer this question, the whole energy-consumption analysis software EnergyPlus was used to simulate the indoor thermal environment and energy consumption in typical office buildings with night mechanical ventilation in three cities in northern China. The summer outdoor climate data was analyzed, and three typical design days were chosen. The most important factorsmore » influencing night ventilation performance such as ventilation rates, ventilation duration, building mass and climatic conditions were evaluated. When night ventilation operation time is closer to active cooling time, the efficiency of night ventilation is higher. With night ventilation rate of 10 ach, the mean radiant temperature of the indoor surface decreased by up to 3.9 C. The longer the duration of operation, the more efficient the night ventilation strategy becomes. The control strategies for three locations are given in the paper. Based on the optimized strategies, the operation consumption and fees are calculated. The results show that more energy is saved in office buildings cooled by a night ventilation system in northern China than ones that do not employ this strategy. (author)« less

Bioclimatological rating of cities and resorts in South Africa according to the Climate Index

NASA Astrophysics Data System (ADS)

Becker, S.

2000-10-01

The climatic conditions of 31 cities and resorts in South Africa have been examined with regard to the thermal perception of people. The evaluation of the thermal conditions is based on the human energy balance calculations, which have been specified for the detection of hot or cold discomfort of people walking outdoors in spite of adapted clothing. Hot days and cold days are defined depending on the extent and duration of thermal discomfort. Cities are rated according to the Climate Index (CI), which is defined in terms of the monthly frequency of hot or cold days. The most pleasant conditions in the annual average can be found along the coastal belt (Port St. Johns, Richards Bay, St. Lucia), the most unpleasant ones in the mediterranean region around Cape Town, the Karoo and the eastern lowveld.

The response of the Okhotsk Sea environment to the orbital-millennium global climate changes during the Last Glacial Maximum, deglaciation and Holocene

NASA Astrophysics Data System (ADS)

Gorbarenko, Sergey A.; Artemova, Antonina V.; Goldberg, Evgeniy L.; Vasilenko, Yuriy P.

2014-05-01

Reconstruction of regional climate and the Okhotsk Sea (OS) environment for the Last Glacial Maximum (LGM), deglaciation and Holocene was performed on the basis of high-resolution records of ice rafted debris (IRD), СаСО3, opal, total organic carbon (TOС), biogenic Ba (Ba_bio) and redox sensitive element (Mn, Mo) content, and diatom and pollen results of four cores that form a north-southern transect. Age models of the studied cores were earlier established by AMS 14C data, oxygen-isotope chronostratigraphy and tephrochronology. According to received results, since 25 ka the regional climate and OS environmental conditions have changed synchronously with LGM condition, cold Heinrich event 1, Bølling-Allerød (BA) warming, Younger Dryas (YD) cooling and Pre-Boreal (PB) warming recorded in the Greenland ice core, North Atlantic sediment, and China cave stalagmites. Calculation of IRD MAR in sediment of north-south transect cores indicates an increase of sea ice formation several times in the glacial OS as compared to the Late Holocene. Accompanying ice formation, increased brine rejection and the larger potential density of surface water at the north shelf due to a drop of glacial East Asia summer monsoon precipitation and Amur River run off, led to strong enhancement of the role of the OS in glacial North Pacific Intermediate Water (NPIW) formation. The remarkable increase in OS productivity during BA and PB warming was probably related with significant reorganisation of the North Pacific deep water ventilation and nutrient input into the NPIW and OS Intermediate Water (OSIW). Seven Holocene OS millennial cold events based on the elevated values of the detrended IRD stack record over the IRD broad trend in the sediments of the studied cores have occurred synchronously with cold events recorded in the North Atlantic, Greenland ice cores and China cave stalagmites after 9 ka. Diatom production in the OS was mostly controlled by sea ice cover changes and surface water stratification induced by sea-ice melting; therefore significant opal accumulation in sediments of this basin begin from 4 to 6 ka ago simultaneously with a remarkable decrease of sea ice cover.

A model for evaluating stream temperature response to climate change in Wisconsin

USGS Publications Warehouse

Stewart, Jana S.; Westenbroek, Stephen M.; Mitro, Matthew G.; Lyons, John D.; Kammel, Leah E.; Buchwald, Cheryl A.

2015-01-01

Integrating the SWB Model with the ANN Model provided a mechanism by which downscaled global or regional climate model results could be used to estimate the potential effects of climate change on future stream temperature on a daily time step. To address future climate scenarios, statistically downscaled air temperature and precipitation projections from 10 GCMs and 2 time periods were used with the SWB-ANNv1 Model to project future stream temperature. Projections of future stream temperatures at mid- (2046–65) and late- (2081–2100) 21st century showed the July mean water temperature increasing for all stream segments with about 80 percent of stream kilometers increasing by 1 to 2 degrees Celsius (°C) by mid-century and about 99 percent increasing by 1 to 3 °C by late-century. Projected changes in stream temperatures also affected changes in thermal classes with a loss in the total amount of cold-water, cold-transition, and warm-transition thermal habitat and a gain in warm-water and very warm thermal habitat for both mid- and late-21st century time periods. The greatest losses occurred for cold-water streams and the greatest gains for warm-water streams, with a contraction of cold-water streams in the Driftless Area of western and southern Wisconsin and an expansion of warm-water streams across northern Wisconsin. Results of this study suggest that such changes will affect the composition of fish assemblages, with a loss of suitable habitat for cold-water fishes and gain in suitable habitat for warm-water fishes. In the end, these projected changes in thermal habitat attributable to climate may result in a net loss of fisheries, because many warm-water species may be unable to colonize habitats formerly occupied by cold-water species because of other habitat limitations (e.g., stream size, gradient). Although projected stream temperatures may vary greatly, depending on the emissions scenario and models used, the results presented in this report represent one possibility. The relative change in stream temperature can provide useful information for planning for potential climate impacts to aquatic ecosystems. Model results can be used to help identify vulnerabilities of streams to climate change, guide stream surveys and thermal classifications, prioritize the allocation of scarce financial resources, identify approaches to climate adaptation to best protect and enhance resiliency in stream thermal habitat, and provide information to make quantitative assessments of statewide stream resources.

Integrating net-zero energy and high-performance green building technologies into contemporary housing in a cold climate

Treesearch

Martin Yoklic; Mark Knaebe; Karen Martinson

2010-01-01

The objectives of this research project are (1) to show how the sustainable resources of forest biomass, solar energy, harvested rainwater, and small-diameter logs can be integrated to a system that provides most or all of the energy and water needs of a typical cold climate residential household, and (2) to effectively interpret the results and convey the sustainable...

Cold flow properties of biodiesel: A guide to getting an accurate analysis

USDA-ARS?s Scientific Manuscript database

Biodiesel has several advantages compared to conventional diesel fuel (petrodiesel). Nevertheless, biodiesel has poor cold flow properties that may restrict its use in moderate climates. It is essential that the cold flow properties of biodiesel and its blends with petrodiesel be measured as accurat...

Overwintering of herbaceous plants in a changing climate. Still more questions than answers.

PubMed

Rapacz, Marcin; Ergon, Ashild; Höglind, Mats; Jørgensen, Marit; Jurczyk, Barbara; Ostrem, Liv; Rognli, Odd Arne; Tronsmo, Anne Marte

2014-08-01

The increase in surface temperature of the Earth indicates a lower risk of exposure for temperate grassland and crop to extremely low temperatures. However, the risk of low winter survival rate, especially in higher latitudes may not be smaller, due to complex interactions among different environmental factors. For example, the frequency, degree and length of extreme winter warming events, leading to snowmelt during winter increased, affecting the risks of anoxia, ice encasement and freezing of plants not covered with snow. Future climate projections suggest that cold acclimation will occur later in autumn, under shorter photoperiod and lower light intensity, which may affect the energy partitioning between the elongation growth, accumulation of organic reserves and cold acclimation. Rising CO2 levels may also disturb the cold acclimation process. Predicting problems with winter pathogens is also very complex, because climate change may greatly influence the pathogen population and because the plant resistance to these pathogens is increased by cold acclimation. All these factors, often with contradictory effects on winter survival, make plant overwintering viability under future climates an open question. Close cooperation between climatologists, ecologists, plant physiologists, geneticists and plant breeders is strongly required to predict and prevent possible problems. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

The effects of ambient temperature on cerebrovascular mortality: an epidemiologic study in four climatic zones in China

PubMed Central

2014-01-01

Background Little evidence is available about the association between temperature and cerebrovascular mortality in China. This study aims to examine the effects of ambient temperature on cerebrovascular mortality in different climatic zones in China. Method We obtained daily data on weather conditions, air pollution and cerebrovascular deaths from five cities (Beijing, Tianjin, Shanghai, Wuhan, and Guangzhou) in China during 2004-2008. We examined city-specific associations between ambient temperature and the cerebrovascular mortality, while adjusting for season, long-term trends, day of the week, relative humidity and air pollution. We examined cold effects using a 1°C decrease in temperature below a city-specific threshold, and hot effects using a 1°C increase in temperature above a city-specific threshold. We used a meta-analysis to summarize the cold and hot effects across the five cities. Results Beijing and Tianjin (with low mean temperature) had lower thresholds than Shanghai, Wuhan and Guangzhou (with high mean temperature). In Beijing, Tianjin, Wuhan and Guangzhou cold effects were delayed, while in Shanghai there was no or short induction. Hot effects were acute in all five cities. The cold effects lasted longer than hot effects. The hot effects were followed by mortality displacement. The pooled relative risk associated with a 1°C decrease in temperature below thresholds (cold effect) was 1.037 (95% confidence interval (CI): 1.020, 1.053). The pooled relative risk associated with a 1°C increase in temperature above thresholds (hot effect) was 1.014 (95% CI: 0.979, 1.050). Conclusion Cold temperatures are significantly associated with cerebrovascular mortality in China, while hot effect is not significant. People in colder climate cities were sensitive to hot temperatures, while people in warmer climate cities were vulnerable to cold temperature. PMID:24690204

Extensive Acclimation in Ectotherms Conceals Interspecific Variation in Thermal Tolerance Limits

PubMed Central

Pintor, Anna F. V.; Schwarzkopf, Lin; Krockenberger, Andrew K.

2016-01-01

Species’ tolerance limits determine their capacity to tolerate climatic extremes and limit their potential distributions. Interspecific variation in thermal tolerances is often proposed to indicate climatic vulnerability and is, therefore, the subject of many recent meta-studies on differential capacities of species from climatically different habitats to deal with climate change. Most studies on thermal tolerances do not acclimate animals or use inconsistent, and insufficient, acclimation times, limiting our knowledge of the shape, duration and extent of acclimation responses. Consequently patterns in thermal tolerances observed in meta-analyses, based on data from the literature are based on inconsistent, partial acclimation and true trends may be obscured. In this study we describe time-course of complete acclimation of critical thermal minima in the tropical ectotherm Carlia longipes and compare it to the average acclimation response of other reptiles, estimated from published data, to assess how much acclimation time may contribute to observed differences in thermal limits. Carlia longipes decreased their lower critical thermal limits by 2.4°C and completed 95% of acclimation in 17 weeks. Wild populations did not mirror this acclimation process over the winter. Other reptiles appear to decrease cold tolerance more quickly (95% in 7 weeks) and to a greater extent, with an estimated average acclimation response of 6.1°C. However, without data on tolerances after longer acclimation times available, our capacity to estimate final acclimation state is very limited. Based on the subset of data available for meta-analysis, much of the variation in cold tolerance observed in the literature can be attributed to acclimation time. Our results indicate that (i) acclimation responses can be slow and substantial, even in tropical species, and (ii) interspecific differences in acclimation speed and extent may obscure trends assessed in some meta-studies. Cold tolerances of wild animals are representative of cumulative responses to recent environments, while lengthy acclimation is necessary for controlled comparisons of physiological tolerances. Measures of inconsistent, intermediate acclimation states, as reported by many studies, represent neither the realised nor the potential tolerance in that population, are very likely underestimates of species’ physiological capacities and may consequently be of limited value. PMID:26990769

Extensive Acclimation in Ectotherms Conceals Interspecific Variation in Thermal Tolerance Limits.

PubMed

Pintor, Anna F V; Schwarzkopf, Lin; Krockenberger, Andrew K

2016-01-01

Species' tolerance limits determine their capacity to tolerate climatic extremes and limit their potential distributions. Interspecific variation in thermal tolerances is often proposed to indicate climatic vulnerability and is, therefore, the subject of many recent meta-studies on differential capacities of species from climatically different habitats to deal with climate change. Most studies on thermal tolerances do not acclimate animals or use inconsistent, and insufficient, acclimation times, limiting our knowledge of the shape, duration and extent of acclimation responses. Consequently patterns in thermal tolerances observed in meta-analyses, based on data from the literature are based on inconsistent, partial acclimation and true trends may be obscured. In this study we describe time-course of complete acclimation of critical thermal minima in the tropical ectotherm Carlia longipes and compare it to the average acclimation response of other reptiles, estimated from published data, to assess how much acclimation time may contribute to observed differences in thermal limits. Carlia longipes decreased their lower critical thermal limits by 2.4°C and completed 95% of acclimation in 17 weeks. Wild populations did not mirror this acclimation process over the winter. Other reptiles appear to decrease cold tolerance more quickly (95% in 7 weeks) and to a greater extent, with an estimated average acclimation response of 6.1°C. However, without data on tolerances after longer acclimation times available, our capacity to estimate final acclimation state is very limited. Based on the subset of data available for meta-analysis, much of the variation in cold tolerance observed in the literature can be attributed to acclimation time. Our results indicate that (i) acclimation responses can be slow and substantial, even in tropical species, and (ii) interspecific differences in acclimation speed and extent may obscure trends assessed in some meta-studies. Cold tolerances of wild animals are representative of cumulative responses to recent environments, while lengthy acclimation is necessary for controlled comparisons of physiological tolerances. Measures of inconsistent, intermediate acclimation states, as reported by many studies, represent neither the realised nor the potential tolerance in that population, are very likely underestimates of species' physiological capacities and may consequently be of limited value.

Impacts of extreme climatic events on the energetics of long-lived vertebrates: the case of the greater flamingo facing cold spells in the Camargue.

PubMed

Deville, Anne-Sophie; Labaude, Sophie; Robin, Jean-Patrice; Béchet, Arnaud; Gauthier-Clerc, Michel; Porter, Warren; Fitzpatrick, Megan; Mathewson, Paul; Grémillet, David

2014-10-15

Most studies analyzing the effects of global warming on wild populations focus on gradual temperature changes, yet it is also important to understand the impact of extreme climatic events. Here we studied the effect of two cold spells (January 1985 and February 2012) on the energetics of greater flamingos (Phoenicopterus roseus) in the Camargue (southern France). To understand the cause of observed flamingo mass mortalities, we first assessed the energy stores of flamingos found dead in February 2012, and compared them with those found in other bird species exposed to cold spells and/or fasting. Second, we evaluated the monthly energy requirements of flamingos across 1980-2012 using the mechanistic model Niche Mapper. Our results show that the body lipids of flamingos found dead in 2012 corresponded to 2.6±0.3% of total body mass, which is close to results found in woodcocks (Scolopax rusticola) that died from starvation during a cold spell (1.7±0.1%), and much lower than in woodcocks which were fed throughout this same cold spell (13.0±2%). Further, Niche Mapper predicted that flamingo energy requirements were highest (+6-7%) during the 1985 and 2012 cold spells compared with 'normal' winters. This increase was primarily driven by cold air temperatures. Overall, our findings strongly suggest that flamingos starved to death during both cold spells. This study demonstrates the relevance of using mechanistic energetics modelling and body condition analyses to understand and predict the impact of extreme climatic events on animal energy balance and winter survival probabilities. © 2014. Published by The Company of Biologists Ltd.

Anomalous cold in the Pangaean tropics

USGS Publications Warehouse

Soreghan, G.S.; Soreghan, M.J.; Poulsen, C.J.; Young, R.A.; Eble, C.F.; Sweet, D.E.; Davogustto, O.C.

2008-01-01

The late Paleozoic archives the greatest glaciation of the Phanerozoic. Whereas high-latitude Gondwanan strata preserve widespread evidence for continental ice, the Permo-Carboniferous tropics have long been considered analogous to today's: warm and shielded from the highlatitude cold. Here, we report on glacial and periglacial indicators that record episodes of freezing continental temperatures in western equatorial Pangaea. An exhumed glacial valley and associated deposits record direct evidence for glaciation that extended to low paleoelevations in the ancestral Rocky Mountains. Furthermore, the Permo-Carboniferous archives the only known occurrence of widespread tropical loess in Earth's history; the volume, chemistry, and provenance of this loess(ite) is most consistent with glacial derivation. Together with emerging indicators for cold elsewhere in low-latitude Pangaea, these results suggest that tropical climate was not buffered from the high latitudes and may record glacial-interglacial climate shifts of very large magnitude. Coupled climate-ice sheet model simulations demonstrate that low atmospheric CO2 and solar luminosity alone cannot account for such cold, and that other factors must be considered in attempting to explain this 'best-known' analogue to our present Earth. ?? 2008 The Geological Society of America.

Multiple causes of the Younger Dryas cold period: new insights from coupled model experiments constrained by data assimilation

NASA Astrophysics Data System (ADS)

Renssen, Hans; Mairesse, Aurélien; Goosse, Hugues; Mathiot, Pierre; Heiri, Oliver; Roche, Didier M.; Nisancioglu, Kerim H.; Valdes, Paul J.

2016-04-01

The Younger Dryas cooling event disrupted the overall warming trend in the North Atlantic region during the last deglaciation. Climate change during the Younger Dryas was abrupt, and thus provides insights into the sensitivity of the climate system to perturbations. The sudden Younger Dryas cooling has traditionally been attributed to a shut-down of the Atlantic meridional overturning circulation by meltwater discharges. However, alternative explanations such as strong negative radiative forcing and a shift in atmospheric circulation have also been offered. In this study we investigate the importance of these different forcings in coupled climate model experiments constrained by data assimilation. We find that the Younger Dryas climate signal as registered in proxy evidence is best simulated using a combination of processes: a weakened Atlantic meridional overturning circulation, moderate negative radiative forcing and an altered atmospheric circulation. We conclude that none of the individual mechanisms alone provide a plausible explanation for the Younger Dryas cold period. We suggest that the triggers for abrupt climate changes like the Younger Dryas are more complex than suggested so far, and that studies on the response of the climate system to perturbations should account for this complexity. Reference: Renssen, H. et al. (2015) Multiple causes of the Younger Dryas cold period. Nature Geoscience 8, 946-949.

Response of the North Atlantic surface and intermediate ocean structure to climate warming of MIS 11.

PubMed

Kandiano, Evgenia S; van der Meer, Marcel T J; Schouten, Stefan; Fahl, Kirsten; Sinninghe Damsté, Jaap S; Bauch, Henning A

2017-04-10

Investigating past interglacial climates not only help to understand how the climate system operates in general, it also forms a vital basis for climate predictions. We reconstructed vertical stratification changes in temperature and salinity in the North Atlantic for a period some 400 ka ago (MIS11), an interglacial time analogue of a future climate. As inferred from a unique set of biogeochemical, geochemical, and faunal data, the internal upper ocean stratification across MIS 11 shows distinct depth-dependent dynamical changes related to vertical as well as lateral shifts in the upper Atlantic meridional circulation system. Importantly, transient cold events are recognized near the end of the long phase of postglacial warming at surface, subsurface, mid, and deeper water layers. These data demonstrate that MIS 11 coolings over the North Atlantic were initially triggered by freshwater input at the surface and expansion of cold polar waters into the Subpolar Gyre. The cooling signal was then transmitted downwards into mid-water depths. Since the cold events occurred after the main deglacial phase we suggest that their cause might be related to continuous melting of the Greenland ice sheet, a mechanism that might also be relevant for the present and upcoming climate.

Know your limits? Climate extremes impact the range of Scots pine in unexpected places.

PubMed

Julio Camarero, J; Gazol, Antonio; Sancho-Benages, Santiago; Sangüesa-Barreda, Gabriel

2015-11-01

Although extreme climatic events such as drought are known to modify forest dynamics by triggering tree dieback, the impact of extreme cold events, especially at the low-latitude margin ('rear edge') of species distributional ranges, has received little attention. The aim of this study was to examine the impact of one such extreme cold event on a population of Scots pine (Pinus sylvestris) along the species' European southern rear-edge range limit and to determine how such events can be incorporated into species distribution models (SDMs). A combination of dendrochronology and field observation was used to quantify how an extreme cold event in 2001 in eastern Spain affected growth, needle loss and mortality of Scots pine. Long-term European climatic data sets were used to contextualize the severity of the 2001 event, and an SDM for Scots pine in Europe was used to predict climatic range limits. The 2001 winter reached record minimum temperatures (equivalent to the maximum European-wide diurnal ranges) and, for trees already stressed by a preceding dry summer and autumn, this caused dieback and large-scale mortality. Needle loss and mortality were particularly evident in south-facing sites, where post-event recovery was greatly reduced. The SDM predicted European Scots pine distribution mainly on the basis of responses to maximum and minimum monthly temperatures, but in comparison with this the observed effects of the 2001 cold event at the southerly edge of the range limit were unforeseen. The results suggest that in order to better forecast how anthropogenic climate change might affect future forest distributions, distribution modelling techniques such as SDMs must incorporate climatic extremes. For Scots pine, this study shows that the effects of cold extremes should be included across the entire distribution margin, including the southern 'rear edge', in order to avoid biased predictions based solely on warmer climatic scenarios. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

International study of temperature, heat and urban mortality: the 'ISOTHURM' project.

PubMed

McMichael, Anthony J; Wilkinson, Paul; Kovats, R Sari; Pattenden, Sam; Hajat, Shakoor; Armstrong, Ben; Vajanapoom, Nitaya; Niciu, Emilia M; Mahomed, Hassan; Kingkeow, Chamnong; Kosnik, Mitja; O'Neill, Marie S; Romieu, Isabelle; Ramirez-Aguilar, Matiana; Barreto, Mauricio L; Gouveia, Nelson; Nikiforov, Bojidar

2008-10-01

This study describes heat- and cold-related mortality in 12 urban populations in low- and middle-income countries, thereby extending knowledge of how diverse populations, in non-OECD countries, respond to temperature extremes. The cities were: Delhi, Monterrey, Mexico City, Chiang Mai, Bangkok, Salvador, São Paulo, Santiago, Cape Town, Ljubljana, Bucharest and Sofia. For each city, daily mortality was examined in relation to ambient temperature using autoregressive Poisson models (2- to 5-year series) adjusted for season, relative humidity, air pollution, day of week and public holidays. Most cities showed a U-shaped temperature-mortality relationship, with clear evidence of increasing death rates at colder temperatures in all cities except Ljubljana, Salvador and Delhi and with increasing heat in all cities except Chiang Mai and Cape Town. Estimates of the temperature threshold below which cold-related mortality began to increase ranged from 15 degrees C to 29 degrees C; the threshold for heat-related deaths ranged from 16 degrees C to 31 degrees C. Heat thresholds were generally higher in cities with warmer climates, while cold thresholds were unrelated to climate. Urban populations, in diverse geographic settings, experience increases in mortality due to both high and low temperatures. The effects of heat and cold vary depending on climate and non-climate factors such as the population disease profile and age structure. Although such populations will undergo some adaptation to increasing temperatures, many are likely to have substantial vulnerability to climate change. Additional research is needed to elucidate vulnerability within populations.

Paleoclimate diagnostics: consistent large-scale temperature responses in warm and cold climates

NASA Astrophysics Data System (ADS)

Izumi, Kenji; Bartlein, Patrick; Harrison, Sandy

2015-04-01

The CMIP5 model simulations of the large-scale temperature responses to increased raditative forcing include enhanced land-ocean contrast, stronger response at higher latitudes than in the tropics, and differential responses in warm and cool season climates to uniform forcing. Here we show that these patterns are also characteristic of CMIP5 model simulations of past climates. The differences in the responses over land as opposed to over the ocean, between high and low latitudes, and between summer and winter are remarkably consistent (proportional and nearly linear) across simulations of both cold and warm climates. Similar patterns also appear in historical observations and paleoclimatic reconstructions, implying that such responses are characteristic features of the climate system and not simple model artifacts, thereby increasing our confidence in the ability of climate models to correctly simulate different climatic states. We also show the possibility that a small set of common mechanisms control these large-scale responses of the climate system across multiple states.

High resolution climatic variations recorded by mollusk fauna at Nussloch (Rhine valley, Germany) during the last glaciation

NASA Astrophysics Data System (ADS)

Moine, O.; Rousseau, D. D.; Antoine, P.

2003-04-01

Between 31 and 19 kyr B.P. important eolian sediments deposited in Western Europe at Nussloch favored by the enhanced atmospheric circulation at mid-latitudes and large areas of deflation providing quantities of material. The 10m-high studied sequence is composed of an alternation of nine gley-loess cycles deposited in a steppic environment. During gley formations, the climate is less windy, colder and more humid, and the malacofaunas have lower diversity and equitability than during the loess deposition. Top of the gleys is characterized by the thaw of the permafrost, when it is present, and by a demographic explosion of the mollusk fauna. Similar lithological alternations have been evidenced in all the Late Pleistocene deposits in Western Europe. They suggest that global climatic variations had a strong influence on the continental domain in Europe during this interval. Using the GRIP timescale, previously adapted to our loess sequence, we showed that the terrestrial mollusk abundance matches with the d18O of the Greenland ice-core. Thus, the high biological abundances regularly occurring in the sequence is interpreted be related to climate ameliorations. Nevertheless, the system is disturbed in the upper part of the sequence due to a strong increase in local moisture indicated by a decrease in both mollusk species richness and in d13C of the organic matter of the soil, restraining the development of the malacofauna during climatic improvements. The comparison with marine proxies indicates that the composition of the assemblages during the Heinrich 3 event had a higher proportion of semi-open environment species than during Heinrich 2 event, that could suggest a less severe climate. Furthermore, Heinrich 3 event is preceding by few particular assemblages typical of a very cold and humid environment. A strong amount of precipitation could have occurred at this time on the European continent, and could explain the important expansion of the Scandinavian ice-sheet southward just before the Last Glacial Maximum.

Middle Holocene rapid environmental changes and human adaptation in Greece

NASA Astrophysics Data System (ADS)

Lespez, Laurent; Glais, Arthur; Lopez-Saez, José-Antonio; Le Drezen, Yann; Tsirtsoni, Zoï; Davidson, Robert; Biree, Laetitia; Malamidou, Dimitra

2016-03-01

Numerous researchers discuss of the collapse of civilizations in response to abrupt climate change in the Mediterranean region. The period between 6500 and 5000 cal yr BP is one of the least studied episodes of rapid climate change at the end of the Late Neolithic. This period is characterized by a dramatic decline in settlement and a cultural break in the Balkans. High-resolution paleoenvironmental proxy data obtained in the Lower Angitis Valley enables an examination of the societal responses to rapid climatic change in Greece. Development of a lasting fluvio-lacustrine environment followed by enhanced fluvial activity is evident from 6000 cal yr BP. Paleoecological data show a succession of dry events at 5800-5700, 5450 and 5000-4900 cal yr BP. These events correspond to incursion of cold air masses to the eastern Mediterranean, confirming the climatic instability of the middle Holocene climate transition. Two periods with farming and pastural activities (6300-5600 and 5100-4700 cal BP) are evident. The intervening period is marked by environmental changes, but the continuous occurrence of anthropogenic taxa suggests the persistence of human activities despite the absence of archaeological evidence. The environmental factors alone were not sufficient to trigger the observed societal changes.

Vertical climatic belts in the Tatra Mountains in the light of current climate change

NASA Astrophysics Data System (ADS)

Łupikasza, Ewa; Szypuła, Bartłomiej

2018-04-01

The paper discusses temporal changes in the configuration of vertical climatic belts in the Tatra Mountains as a result of current climate change. Meteorological stations are scarce in the Tatra Mountains; therefore, we modelled decadal air temperatures using existing data from 20 meteorological stations and the relationship between air temperature and altitude. Air temperature was modelled separately for northern and southern slopes and for convex and concave landforms. Decadal air temperatures were additionally used to delineate five climatic belts previously distinguished by Hess on the basis of threshold values of annual air temperature. The spatial extent and location of the borderline isotherms of 6, 4, 2, 0, and - 2 °C for four decades, including 1951-1960, 1981-1990, 1991-2000, and 2001-2010, were compared. Significant warming in the Tatra Mountains, uniform in the vertical profile, started at the beginning of the 1980s and led to clear changes in the extent and location of the vertical climatic belts delineated on the basis of annual air temperature. The uphill shift of the borderline isotherms was more prominent on southern than on northern slopes. The highest rate of changes in the extent of the climatic belts was found above the isotherm of 0 °C (moderately cold and cold belts). The cold belt dramatically diminished in extent over the research period.

Protection against cold in prehospital care: evaporative heat loss reduction by wet clothing removal or the addition of a vapor barrier--a thermal manikin study.

PubMed

Henriksson, Otto; Lundgren, Peter; Kuklane, Kalev; Holmér, Ingvar; Naredi, Peter; Bjornstig, Ulf

2012-02-01

In the prehospital care of a cold and wet person, early application of adequate insulation is of utmost importance to reduce cold stress, limit body core cooling, and prevent deterioration of the patient's condition. Most prehospital guidelines on protection against cold recommend the removal of wet clothing prior to insulation, and some also recommend the use of a waterproof vapor barrier to reduce evaporative heat loss. However, there is little scientific evidence of the effectiveness of these measures. Using a thermal manikin with wet clothing, this study was conducted to determine the effect of wet clothing removal or the addition of a vapor barrier on thermal insulation and evaporative heat loss using different amounts of insulation in both warm and cold ambient conditions. A thermal manikin dressed in wet clothing was set up in accordance with the European Standard for assessing requirements of sleeping bags, modified for wet heat loss determination, and the climatic chamber was set to -15 degrees Celsius (°C) for cold conditions and +10°C for warm conditions. Three different insulation ensembles, one, two or seven woollen blankets, were chosen to provide different levels of insulation. Five different test conditions were evaluated for all three levels of insulation ensembles: (1) dry underwear; (2) dry underwear with a vapor barrier; (3) wet underwear; (4) wet underwear with a vapor barrier; and (5) no underwear. Dry and wet heat loss and thermal resistance were determined from continuous monitoring of ambient air temperature, manikin surface temperature, heat flux and evaporative mass loss rate. Independent of insulation thickness or ambient temperature, the removal of wet clothing or the addition of a vapor barrier resulted in a reduction in total heat loss of 19-42%. The absolute heat loss reduction was greater, however, and thus clinically more important in cold environments when little insulation is available. A similar reduction in total heat loss was also achieved by increasing the insulation from one to two blankets or from two to seven blankets. Wet clothing removal or the addition of a vapor barrier effectively reduced evaporative heat loss and might thus be of great importance in prehospital rescue scenarios in cold environments with limited insulation available, such as in mass-casualty situations or during protracted evacuations in harsh conditions.

Preference for safflower oil in rats exposed to a cold environment under free-feeding conditions.

PubMed

Saitoh, Masaji; Ishii, Toshiaki; Takewaki, Tadashi; Nishimura, Masakazu

2005-07-01

There are several benefits to a high-fat diet for animals exposed to cold, including improved tolerance to severe cold conditions and increased survival rates in cold environments. It is therefore of interest to examine whether animals exposed to cold will selectively consume lipids. We examined the intake of safflower oil (SO) by rats exposed to cold (4 +/- 2 degrees C) under a feeding condition in which the rats were given free access to SO. Rats exposed to cold consumed more SO than those housed at 25 +/- 2 degrees C. This finding suggests that rats prefer SO in a cold environment. There was no significant difference in the ratio of calories of SO ingested to that of matter (standard laboratory chow plus SO) ingested between rats exposed to cold and those at 25 +/- 2 degrees C. The high SO intake also affected cold tolerance and metabolite kinetics in the rats. Factors that affected the SO intake of rats exposed to cold are also discussed.

The Effect of Soil Temperature Seasonality on Climate Reconstructions from Paleosols

NASA Astrophysics Data System (ADS)

Gallagher, T. M.; Hren, M. T.; Sheldon, N. D.

2017-12-01

Accurate continental temperature reconstructions provide important constraints on climate sensitivity to changes in atmospheric pCO2, the timing and rates of tectonic uplift, and the driving mechanisms and feedbacks associated with major climate events. Temperature seasonality is an important variable to consider, because not only does it exert a strong control on the biosphere, but it can obfuscate changes in mean annual air temperature (MAAT) in the geologic record. In order to better understand the effect temperature seasonality has on paleosol temperature proxies, soil temperature data was compiled from over 200 stations that comprise the NCDC Soil Climate Analysis Network. Observed soil temperature variations were then compared to predicted soil temperature values based on normal seasonal air temperature trends. Approximately one quarter of sites record less temperature variation than predicted. This reduction in soil temperature seasonality is a result of warmer than predicted cold-season temperatures, driven by cold-season processes such as snow cover insulation. The reduction in soil temperature seasonality explains why pedo-transfer functions to break down below MAAT values of 6-8 °C. Greater than predicted soil temperature seasonality is observed at nearly half of the sites, driven primarily by direct heating of the soil surface by solar radiation. Deviations larger than 2 °C are not common until mean annual precipitation falls below 300 mm, suggesting that complications introduced by ground heating are primarily restricted to paleosols that formed in more arid environments. Clumped isotope measurements of pedogenic carbonate and bulk paleosol elemental data from a stacked series of paleosols spanning the Eocene-Oligocene in Northeastern Spain are also examined to demonstrate how the documented seasonal trends in modern soils can help inform paleo-applications.

Meteorological Situations Favouring the Development of Dust Plumes over Iceland

NASA Astrophysics Data System (ADS)

Schepanski, K.; Szodry, K.

2017-12-01

The knowledge on mineral dust emitted at high latitudes is limited, but its impact on the polar environments is divers. Within a warming climate, dust emitted from regions in cold climates is expected to increase due to the retreat of the ice sheet and increasing melting rates. Therefore, and for its extensive impacts on different aspects of the climate system, a better understanding of the atmospheric dust life-cycle at high latitudes/cold climates in general, and the spatio-temporal distribution of dust sources in particular, are essential. At high-latitudes, glacio-fluvial sediments as found on river flood plains e.g. supplied by glaciers are prone to wind erosion when dry and bare. In case of the occurrence of strong winds, sediments are blown out and dust plumes develop. As dust uplift is controlled by soil surface characteristics, the availability of suitable sediments, and atmospheric conditions, an interannual variability in dust source activity is expected. We investigated atmospheric circulation patterns that favour the development of dust plumes over Iceland, which presents a well-known dust source at high latitudes. Using the atmosphere model COSMO (COnsortium for Small-scale MOdeling), we analysed the wind speed distribution over the Iceland region for identified and documented dust cases. As one outcome of the study, the position of the Icelandic low, the anticyclones located over Northern Europe, and the resulting pressure gradients are of particular relevance. The interaction of the synoptic-scale winds with the Icelandic orography may locally enhance the wind speeds and thus foster local dust emission. Results from this study suggest that the atmospheric circulation determined by the pressure pattern is of particular relevance for the formation of dust plumes entering the North Atlantic.

Field Performance of Inverter-Driven Heat Pumps in Cold Climates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Williamson, James; Aldrich, Robb

2015-08-19

Traditionally, air-source heat pumps (ASHPs) have been used more often in warmer climates; however, some new ASHPs are gaining ground in colder areas. These systems operate at subzero (Fahrenheit) temperatures and many do not include backup electric resistance elements. There are still uncertainties, however, about capacity and efficiency in cold weather. Also, questions such as “how cold is too cold?” do not have clear answers. These uncertainties could lead to skepticism among homeowners; poor energy savings estimates; suboptimal system selection by heating, ventilating, and air-conditioning contractors; and inconsistent energy modeling. In an effort to better understand and characterize the heatingmore » performance of these units in cold climates, the U.S. Department of Energy Building America team, Consortium for Advanced Residential Buildings (CARB), monitored seven inverter-driven, ductless ASHPs across the Northeast. Operating data were collected for three Mitsubishi FE18 units, three Mitsubishi FE12 units, and one Fujitsu 15RLS2 unit. The intent of this research was to assess heat output, electricity consumption, and coefficients of performance (COPs) at various temperatures and load conditions. This assessment was accomplished with long- and short-term tests that measured power consumption; supply, return, and outdoor air temperatures; and airflow through the indoor fan coil.« less

Static and Fatigue Analysis of Wind Turbine Blades Subject to Cold Weather Conditions Using Finite Element Analysis

NASA Astrophysics Data System (ADS)

Lillo Gallardo, Patricio Andres

Canada has aggressive targets for introducing wind energy across the country, but also faces challenges in achieving these goals due to the harsh Canadian climate. One issue which has received little attention in other countries not experiencing these extremes is the behaviour of composite blades in winter conditions. The scope of the work presented is to analyze the static stresses and fatigue response in cold climates using finite element models of the blade. The work opens with a quantification of the extremes of cold experienced in candidate Canadian wind turbine deployment locations. The thesis then narrows its focus to a consideration of the stresses in the root of the composite blades, specifically two common blade-hub connection methods: embedded root carrots and T-bolts. Finite element models of the root are proposed to properly simulate boundary conditions, applied loading and thermal stresses for a 1.5 MW wind turbine. It is shown that the blade root is strongly affected by the thermal stresses caused by the mismatch and orthotrophy of the coefficients of thermal expansion of the blade root constituents. Fatigue analysis of a blade is then presented using temperature dependent material properties including estimated fatigue coefficients.It was found that the natural frequencies of a 1.5 MW wind turbine blade are not significantly altered at cold temperatures. Additionally, cold temperatures slightly increase stresses in the composite blade skin when the blade is loaded, due to an increase in stiffness. Cold temperatures also lead to higher cyclic flapwise bending moments acting on the blade. However, this increase was found not to affect the lifetime fatigue damage. Finally, it was found that the cold climate as seen in Canada improves the fatigue strength of the saturated composite materials used in the blade. The predicted fatigue damage of the triaxial fabric and the spar cap layers in cold climates was therefore predicted to be half that of the fatigue damage at room temperature. This is caused solely by the temperature dependence of the fatigue coefficient b which requires further experimental verification to validate the numerical results of the current study.

Late Miocene - Pliocene Evolution of the Pacific Warm Pool and Cold Tongue: Implications for El Niño

NASA Astrophysics Data System (ADS)

Zhang, Y.; Pagani, M.

2011-12-01

The Western Pacific Warm Pool of the tropical Pacific Ocean retains the largest and warmest sea surface water body on Earth, while the eastern equatorial Pacific is characterized by strong upwelling of cold, nutrient-rich deep waters, termed the Pacific cold tongue. Evolution of the Pacific warm pool and cold tongue are important because they control the circum-Pacific climate and impact the globe via El Niño - Southern Oscillation (ENSO) teleconnections. Sea surface temperature (SST) reconstructions using a single site from the warm pool (ODP 806) and two sites from the cold tongue (ODP 846, 847) suggest that the temperature of the warm pool was "stable" throughout the Plio-Pleistocene, whereas the cold tongue was much warmer in the Pliocene and subsequently cooled. The absence of an east-west Pacific temperature gradient during the early Pliocene is the basis for the "permanent El Niño" hypothesis. However, annually-resolved fossil coral and evaporite records found 3-7 years climate variability during the Pliocene warm period and late Miocene, challenging a "permanent" or invariant climate state. Here we present a multi-proxy (TEX86, UK37, Mg/Ca), multi-site reconstruction of the late Miocene - Pliocene (ca. 12 Ma - 3 Ma) SST in the Pacific warm pool (ODP 806, ODP 769 in the Sulu Sea, ODP 1143 in the South China Sea) and the cold tongue (ODP 850, 849, 846). Our results show that the cold tongue was even warmer in the late Miocene than the Pliocene, and that the warm pool cooled 2-3°C from the late Miocene into the Pliocene - in contrast to the invariant character previously assumed. Temperature comparison between different sites suggests that the warm pool may have expanded in size in the late Miocene. Although eastern and western ends of the tropical Pacific were warmer, a persistent, but low east-west temperature gradient (~3°C) is apparent. This agrees with recent studies which have shown ENSO-related frequency of climate change in the late Miocene and early Pliocene.

Experimental Evidence for Weathering and Martian Sulfate Formation Under Extremely Cold Weather-Limited Environments

NASA Technical Reports Server (NTRS)

Niles, Paul B.; Golden, D. C.; Michalski, J.

2013-01-01

High resolution photography and spectroscopy of the martian surface (MOC, HiRISE) from orbit has revolutionized our view of Mars with one of the most important discoveries being wide-spread layered sedimentary deposits associated with sulfate minerals across the low to mid latitude regions of Mars [1, 2]. The mechanism for sulfate formation on Mars has been frequently attributed to playa-like evaporative environments under prolonged warm conditions [3]. However, there are several problems with the presence of prolonged surface temperatures on Mars above 273 K during the Noachian including the faint young Sun [4] and the presence of suitable greenhouse gases [5]. The geomorphic evidence for early warm conditions may instead be explained by periodic episodes of warming rather than long term prolonged warm temperatures [6]. An alternate view of the ancient martian climate contends that prolonged warm temperatures were never present and that the atmosphere and climate has been similar to modern conditions throughout most of its history [6]. This view is more consistent with the climate models, but has had a difficult time explaining the sedimentary history of Mars and in particular the presence of sulfate minerals. We suggest here that mixtures of atmospheric aerosols, ice, and dust have the potential for creating small films of cryo-concentrated acidic solutions that may represent an important unexamined environment for understanding weathering processes on Mars [7, 8]. This study seeks to test whether sulfate formation may be possible at temperatures well below 0 C in water limited environments removing the need for prolonged warm periods to form sulfates on early Mars.

Nearly synchronous climate change in the Northern Hemisphere during the last glacial termination

USGS Publications Warehouse

Benson, L.; Burdett, J.; Lund, S.; Kashgarian, Michaele; Mensing, S.

1997-01-01

The climate of the North Atlantic region underwent a series of abrupt cold/warm oscillations when the ice sheets of the Northern Hemisphere retreated during the last glacial termination (17.711.5 kyr ago). Evidence for these oscillations, which are recorded in European terrestrial sediments as the Oldest Dryas/Bolling/Older Dryas/Allerod/Younger Dryas vegetational sequence, has been found in Greenland ice cores. The geographical extent of many of these oscillations is not well known, but the last major cold event (the Younger Dryas) seems to have been global in extent. Here we present evidence of four major oscillations in the hydrological balance of the Owens basin, California, that occurred during the last glacial termination. Dry events in western North America occurred at approximately the same time as cold events recorded in Greenland ice, with transitions between climate regimes in the two regions taking place within a few hundred years of each other. Our observations thus support recent climate simulations which indicate that cooling of the North Atlantic Ocean results in cooling of the North Pacific Ocean which, in turn, leads to a drier climate in western North America.

The UTCI-clothing model.

PubMed

Havenith, George; Fiala, Dusan; Błazejczyk, Krzysztof; Richards, Mark; Bröde, Peter; Holmér, Ingvar; Rintamaki, Hannu; Benshabat, Yael; Jendritzky, Gerd

2012-05-01

The Universal Thermal Climate Index (UTCI) was conceived as a thermal index covering the whole climate range from heat to cold. This would be impossible without considering clothing as the interface between the person (here, the physiological model of thermoregulation) and the environment. It was decided to develop a clothing model for this application in which the following three factors were considered: (1) typical dressing behaviour in different temperatures, as observed in the field, resulting in a model of the distribution of clothing over the different body segments in relation to the ambient temperature, (2) the changes in clothing insulation and vapour resistance caused by wind and body movement, and (3) the change in wind speed in relation to the height above ground. The outcome was a clothing model that defines in detail the effective clothing insulation and vapour resistance for each of the thermo-physiological model's body segments over a wide range of climatic conditions. This paper details this model's conception and documents its definitions.

Frequent floods in the European Alps coincide with cooler periods of the past 2500 years

PubMed Central

Glur, Lukas; Wirth, Stefanie B.; Büntgen, Ulf; Gilli, Adrian; Haug, Gerald H.; Schär, Christoph; Beer, Jürg; Anselmetti, Flavio S.

2013-01-01

Severe floods triggered by intense precipitation are among the most destructive natural hazards in Alpine environments, frequently causing large financial and societal damage. Potential enhanced flood occurrence due to global climate change would thus increase threat to settlements, infrastructure, and human lives in the affected regions. Yet, projections of intense precipitation exhibit major uncertainties and robust reconstructions of Alpine floods are limited to the instrumental and historical period. Here we present a 2500-year long flood reconstruction for the European Alps, based on dated sedimentary flood deposits from ten lakes in Switzerland. We show that periods with high flood frequency coincide with cool summer temperatures. This wet-cold synchronism suggests enhanced flood occurrence to be triggered by latitudinal shifts of Atlantic and Mediterranean storm tracks. This paleoclimatic perspective reveals natural analogues for varying climate conditions, and thus can contribute to a better understanding and improved projections of weather extremes under climate change. PMID:24067733

Overwintering temperature and body condition shift emergence dates of spring-emerging solitary bees.

PubMed

Schenk, Mariela; Mitesser, Oliver; Hovestadt, Thomas; Holzschuh, Andrea

2018-01-01

Solitary bees in seasonal environments must align their life-cycles with favorable environmental conditions and resources; the timing of their emergence is highly fitness relevant. In several bee species, overwintering temperature influences both emergence date and body weight at emergence. High variability in emergence dates among specimens overwintering at the same temperatures suggests that the timing of emergence also depends on individual body conditions. However, possible causes for this variability, such as individual differences in body size or weight, have been rarely studied. In a climate chamber experiment using two spring-emerging mason bees ( Osmia cornuta and O. bicornis ), we investigated the relationship between temperature, emergence date, body weight, and body size, the last of which is not affected by overwintering temperature. Our study showed that body weight declined during hibernation more strongly in warm than in cold overwintering temperatures. Although bees emerged earlier in warm than in cold overwintering temperatures, at the time of emergence, bees in warm overwintering temperatures had lower body weights than bees in cold overwintering temperatures (exception of male O. cornuta ). Among specimens that experienced the same overwintering temperatures, small and light bees emerged later than their larger and heavier conspecifics. Using a simple mechanistic model we demonstrated that spring-emerging solitary bees use a strategic approach and emerge at a date that is most promising for their individual fitness expectations. Our results suggest that warmer overwintering temperatures reduce bee fitness by causing a decrease in body weight at emergence. We showed furthermore that in order to adjust their emergence dates, bees use not only temperature but also their individual body condition as triggers. This may explain differing responses to climate warming within and among bee populations and may have consequences for bee-plant interactions as well as for the persistence of bee populations under climate change.

Beneficial effect of hot spring bathing on stress levels in Japanese macaques.

PubMed

Takeshita, Rafaela S C; Bercovitch, Fred B; Kinoshita, Kodzue; Huffman, Michael A

2018-05-01

The ability of animals to survive dramatic climates depends on their physiology, morphology and behaviour, but is often influenced by the configuration of their habitat. Along with autonomic responses, thermoregulatory behaviours, including postural adjustments, social aggregation, and use of trees for shelter, help individuals maintain homeostasis across climate variations. Japanese macaques (Macaca fuscata) are the world's most northerly species of nonhuman primates and have adapted to extremely cold environments. Given that thermoregulatory stress can increase glucocorticoid concentrations in primates, we hypothesized that by using an available hot spring, Japanese macaques could gain protection against weather-induced cold stress during winter. We studied 12 adult female Japanese macaques living in Jigokudani Monkey Park, Japan, during the spring birth season (April to June) and winter mating season (October to December). We collected faecal samples for determination of faecal glucocorticoid (fGC) metabolite concentrations by enzyme immunoassay, as well as behavioural data to determine time spent in the hot springs, dominance rank, aggression rates, and affiliative behaviours. We used nonparametric statistics to examine seasonal changes in hot spring bathing, and the relationship between rank and air temperature on hot spring bathing. We used general linear mixed-effect models to examine factors impacting hormone concentrations. We found that Japanese macaques use hot spring bathing for thermoregulation during the winter. In the studied troop, the single hot spring is a restricted resource favoured by dominant females. High social rank had both costs and benefits: dominant females sustained high fGC levels, which were associated with high aggression rates in winter, but benefited by priority of access to the hot spring, which was associated with low fGC concentrations and therefore might help reduce energy expenditure and subsequent body heat loss. This unique habit of hot spring bathing by Japanese macaques illustrates how behavioural flexibility can help counter cold climate stress, with likely implications for reproduction and survival.

Investigating the impact of atmospheric blocking on temperature extremes across Europe using an objective index

NASA Astrophysics Data System (ADS)

Brunner, Lukas; Steiner, Andrea; Sillmann, Jana

2017-04-01

Atmospheric blocking is a key contributor to European temperature extremes. It leads to stable, long-lasting weather patterns, which favor the development of cold and warm spells. The link between blocking and such temperature extremes differs significantly across Europe. In northern Europe a majority of warm spells are connected to blocking, while cold spells are suppressed during blocked conditions. In southern Europe the opposite picture arises with most cold spells occurring during blocking and warm spells suppressed. Building on earlier work by Brunner et al. (2017) this study aims at a better understanding of the connection between blocking and temperature extremes in Europe. We investigate cold and warm spells with and without blocking in observations from the European daily high-resolution gridded dataset (E-OBS) from 1979 to 2015. We use an objective extreme index (Russo et al. 2015) to identify and compare cold and warm spells across Europe. Our work is lead by the main question: Are cold/warm spells coinciding with blocking different from cold/warm spells during unblocked conditions in regard to duration, extend, or amplitude? Here we present our research question and the study setup, and show first results of our analysis on European temperature extremes. Brunner, L., G. Hegerl, and A. Steiner (2017): Connecting Atmospheric Blocking to European Temperature Extremes in Spring. J. Climate, 30, 585-594, doi: 10.1175/JCLI-D-16-0518.1. Russo, S., J. Sillmann, and E. M. Fischer (2015): Top ten European heatwaves since 1950 and their occurrence in the coming decades. Environ. Res. Lett. 10.12, S. 124003. doi: 10.1088/1748-9326/10/12/124003.

Science questions for implementing climate refugia for cold-water fish as an adaptation strateby

EPA Science Inventory

Managing climate refugia has been proposed as a potential adaptation strategy that may be useful for protecting the biotic integrity of watersheds under a changing climate. Paleo-ecological evidence suggests that refugia allowed species to persist through prior periods of climate...

The role of Xylella fastidiosa cold shock proteins in Pierce’s disease of grapes

USDA-ARS?s Scientific Manuscript database

Pierce’s disease of grapevine, caused by the bacterial pathogen Xylella fastidiosa (Xf) is limited to warmer climates, and plant infection can be eliminated by cold winter conditions. Milder winters can increase the likelihood of pathogen persistence from one growing season to the next. Cold adaptat...

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

Wind-chill-equivalent temperatures: regarding the impact due to the variability of the environmental convective heat transfer coefficient.

PubMed

Shitzer, Avraham

2006-03-01

The wind-chill index (WCI), developed in Antarctica in the 1940s and recently updated by the weather services in the USA and Canada, expresses the enhancement of heat loss in cold climates from exposed body parts, e.g., face, due to wind. The index provides a simple and practical means for assessing the thermal effects of wind on humans outdoors. It is also used for indicating weather conditions that may pose adverse risks of freezing at subfreezing environmental temperatures. Values of the WCI depend on a number of parameters, i.e, temperatures, physical properties of the air, wind speed, etc., and on insolation and evaporation. This paper focuses on the effects of various empirical correlations used in the literature for calculating the convective heat transfer coefficients between humans and their environment. Insolation and evaporation are not included in the presentation. Large differences in calculated values among these correlations are demonstrated and quantified. Steady-state wind-chill-equivalent temperatures (WCETs) are estimated by a simple, one-dimensional heat-conducting hollow-cylindrical model using these empirical correlations. Partial comparison of these values with the published "new" WCETs is presented. The variability of the estimated WCETs, due to different correlations employed to calculate them, is clearly demonstrated. The results of this study clearly suggest the need for establishing a "gold standard" for estimating convective heat exchange between exposed body elements and the cold and windy environment. This should be done prior to the introduction and adoption of further modifications to WCETs and indices. Correlations to estimate the convective heat transfer coefficients between exposed body parts of humans in windy and cold environments influence the WCETs and need to be standardized.

Wind-chill-equivalent temperatures: regarding the impact due to the variability of the environmental convective heat transfer coefficient

NASA Astrophysics Data System (ADS)

Shitzer, Avraham

2006-03-01

The wind-chill index (WCI), developed in Antarctica in the 1940s and recently updated by the weather services in the USA and Canada, expresses the enhancement of heat loss in cold climates from exposed body parts, e.g., face, due to wind. The index provides a simple and practical means for assessing the thermal effects of wind on humans outdoors. It is also used for indicating weather conditions that may pose adverse risks of freezing at subfreezing environmental temperatures. Values of the WCI depend on a number of parameters, i.e, temperatures, physical properties of the air, wind speed, etc., and on insolation and evaporation. This paper focuses on the effects of various empirical correlations used in the literature for calculating the convective heat transfer coefficients between humans and their environment. Insolation and evaporation are not included in the presentation. Large differences in calculated values among these correlations are demonstrated and quantified. Steady-state wind-chill-equivalent temperatures (WCETs) are estimated by a simple, one-dimensional heat-conducting hollow-cylindrical model using these empirical correlations. Partial comparison of these values with the published “new” WCETs is presented. The variability of the estimated WCETs, due to different correlations employed to calculate them, is clearly demonstrated. The results of this study clearly suggest the need for establishing a “gold standard” for estimating convective heat exchange between exposed body elements and the cold and windy environment. This should be done prior to the introduction and adoption of further modifications to WCETs and indices. Correlations to estimate the convective heat transfer coefficients between exposed body parts of humans in windy and cold environments influence the WCETs and need to be standardized.

IEA HPT ANNEX 41 – Cold climate heat pumps: US country report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Groll, Eckhard A.; Baxter, Van D.

In 2012 the International Energy Agency (IEA) Heat Pump Programme (now the Heat Pump Technologies (HPT) program) established Annex 41 to investigate technology solutions to improve performance of heat pumps for cold climates. Four IEA HPT member countries are participating in the Annex – Austria, Canada, Japan, and the United States (U.S.). The principal focus of Annex 41 is on electrically driven air-source heat pumps (ASHP) since that system type has the lowest installation cost of all heat pump alternatives. They also have the most significant performance challenges given their inherent efficiency and capacity issues at cold outdoor temperatures. Availabilitymore » of ASHPs with improved low ambient performance would help bring about a much stronger heat pump market presence in cold areas, which today rely predominantly on fossil fuel furnace heating systems.« less

Evidence for adaptive evolution of low-temperature stress response genes in a Pooideae grass ancestor.

PubMed

Vigeland, Magnus D; Spannagl, Manuel; Asp, Torben; Paina, Cristiana; Rudi, Heidi; Rognli, Odd-Arne; Fjellheim, Siri; Sandve, Simen R

2013-09-01

Adaptation to temperate environments is common in the grass subfamily Pooideae, suggesting an ancestral origin of cold climate adaptation. Here, we investigated substitution rates of genes involved in low-temperature-induced (LTI) stress responses to test the hypothesis that adaptive molecular evolution of LTI pathway genes was important for Pooideae evolution. Substitution rates and signatures of positive selection were analyzed using 4330 gene trees including three warm climate-adapted species (maize (Zea mays), sorghum (Sorghum bicolor), and rice (Oryza sativa)) and five temperate Pooideae species (Brachypodium distachyon, wheat (Triticum aestivum), barley (Hordeum vulgare), Lolium perenne and Festuca pratensis). Nonsynonymous substitution rate differences between Pooideae and warm habitat-adapted species were elevated in LTI trees compared with all trees. Furthermore, signatures of positive selection were significantly stronger in LTI trees after the rice and Pooideae split but before the Brachypodium divergence (P < 0.05). Genome-wide heterogeneity in substitution rates was also observed, reflecting divergent genome evolution processes within these grasses. Our results provide evidence for a link between adaptation to cold habitats and adaptive evolution of LTI stress responses in early Pooideae evolution and shed light on a poorly understood chapter in the evolutionary history of some of the world's most important temperate crops. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

Climate refugia for salmon in a changing world

EPA Science Inventory

Climate change threatens to create fundamental shifts in in the distributions and abundances of endothermic organisms such as cold-water salmon and trout species (salmonids). Recently published projected declines in salmonid distributions under future climates range from modest t...

Enhanced aridity and atmospheric high-pressure stability over the western Mediterranean during the North Atlantic cold events of the past 50 k.y.

NASA Astrophysics Data System (ADS)

Combourieu Nebout, N.; Turon, J. L.; Zahn, R.; Capotondi, L.; Londeix, L.; Pahnke, K.

2002-10-01

Multiproxy paleoenvironmental records (pollen and planktonic isotope) from Ocean Drilling Program Site 976 (Alboran Sea) document rapid ocean and climate variations during the last glacial that follow the Dansgaard-Oeschger climate oscillations seen in the Greenland ice core records, thus suggesting a close link of the Mediterranean climate swings with North Atlantic climates. Continental conditions rapidly oscillated through cold-arid and warm-wet conditions in the course of stadial-interstadial climate jumps. At the time of Heinrich events, i.e., maximum meltwater flux to the North Atlantic, western Mediterranean marine microflora and microfauna show rapid cooling correlated with increasing continental dryness. Enhanced aridity conceivably points to prolonged wintertime stability of atmospheric high-pressure systems over the southwestern Mediterranean in conjunction with cooling of the North Atlantic.

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

NASA Astrophysics Data System (ADS)

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

2013-12-01

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

Decoupled leaf and root carbon economics is a key component in the ecological diversity and evolutionary divergence of deciduous and evergreen lineages of genus Rhododendron.

PubMed

Medeiros, Juliana S; Burns, Jean H; Nicholson, Jaynell; Rogers, Louisa; Valverde-Barrantes, Oscar

2017-06-01

We explored trait-trait and trait-climate relationships for 27 Rhododendron species while accounting for phylogenetic relationships and within-species variation to investigate whether leaf and root traits are coordinated across environments and over evolutionary time, as part of a whole-plant economics spectrum. We examined specific leaf area (SLA) and four root traits: specific root length (SRL), specific root tip abundance (SRTA), first order diameter, and link average length, for plants growing in a cold, seasonal climate (Kirtland, Ohio) and a warmer, less seasonal climate (Federal Way, Washington) in the United States. We estimated a phylogeny and species' climate of origin, determined phylogenetic signal on mean traits and within-species variation, and used phylogenetically informed analysis to compare trait-trait and trait-climate relationships for deciduous and evergreen lineages. Mean SLA and within-species variation in SRL were more similar between close relatives than expected by chance. SLA and root traits differed according to climate of origin and across growth environments, though SLA differed within- and among-species less than roots. A negative SRL-SRTA correlation indicates investment in foraging scale vs. precision as a fundamental trade-off defining the root economic spectrum. Also, the deciduous clade exhibited a strong negative relationship between SLA and SRL, while evergreen clades showed a weaker positive or no relationship. Our work suggests that natural selection has shaped relationships between above- and belowground traits in genus Rhododendron and that leaf and root traits may evolve independently. Morphological decoupling may help explain habitat diversity among Rhododendron species, as well as the changes accompanying the divergence of deciduous and evergreen lineages. © 2017 Botanical Society of America.

Acceleration of thaw slump activity in glaciated landscapes of the Western Canadian Arctic

NASA Astrophysics Data System (ADS)

Segal, Rebecca A.; Lantz, Trevor C.; Kokelj, Steven V.

2016-03-01

Climate change is increasing the frequency and intensity of thermokarst, but the influences of regional climate and physiography remain poorly understood. Retrogressive thaw slumping is one of the most dynamic forms of thermokarst and affects many areas of glaciated terrain across northwestern Canada. In this study, we used airphotos and satellite imagery to investigate the influence of climate and landscape factors on thaw slump dynamics. We assessed slump size, density, and growth rates in four regions of ice-rich terrain with contrasting climate and physiographic conditions: the Jesse Moraine, the Tuktoyaktuk Coastlands, the Bluenose Moraine, and the Peel Plateau. Observed increases in: (1) the area impacted by slumps (+2 to +407%), (2) average slump sizes (+0.31 to +1.82 ha), and (3) slump growth rates (+169 to +465 m2 yr-1) showed that thermokarst activity is rapidly accelerating in ice-rich morainal landscapes in the western Canadian Arctic, where slumping has become a dominant driver of geomorphic change. Differences in slump characteristics among regions indicate that slump development is strongly influenced by topography, ground ice conditions, and Quaternary history. Observed increases in slump activity occurred in conjunction with increases in air temperature and precipitation, but variation in slump activity among the four regions suggests that increased precipitation has been an important driver of change. Our observation that the most rapid intensification of slump activity occurred in the coldest environment (the Jesse Moraine on Banks Island) indicates that ice-cored landscapes in cold permafrost environments are highly vulnerable to climate change.

City 2020+

NASA Astrophysics Data System (ADS)

Schneider, C.; Buttstädt, M.; Merbitz, H.; Sachsen, T.; Ketzler, G.; Michael, S.; Klemme, M.; Dott, W.; Selle, K.; Hofmeister, H.

2010-09-01

This research initiative CITY 2020+ assesses the risks and opportunities for residents in urban built environments under projected demographic and climate change for the year 2020 and beyond, using the City of Aachen as a case study. CITY 2020+ develops scenarios, options and tools for planning and developing sustainable future city structures. We investigate how urban environment, political structure and residential behavior can best be adapted, with attention to the interactions among structural, political, and sociological configurations and with their consequences on human health. Demographers project that in the EU-25-States by 2050, approximately 30% of the population will be over age 65. Also by 2050, average tem¬peratures are projected to rise by 1 to 2 K. Combined, Europe can expect enhanced thermal stress and higher levels of particulate matter. CITY 2020+ amongst other sub-projects includes research project dealing with (1) a micro-scale assessment of blockages to low-level cold-air drainage flow into the city centre by vegetation and building structures, (2) a detailed analysis of the change of probability density functions related to the occurrence of heat waves during summer and the spatial and temporal structure of the urban heat island (UHI) (3) a meso-scale analysis of particulate matter (PM) concentrations depending on topography, local meteorological conditions and synoptic-scale weather patterns. First results will be presented specifically from sub-projects related to vegetation barriers within cold air drainage, the assessment of the UHI and the temporal and spatial pattern of PM loadings in the city centre. The analysis of the cold air drainage flow is investigated in two consecutive years with a clearing of vegetation stands in the beginning of the second year early in 2010. The spatial pattern of the UHI and its possible enhancement by climate change is addressed employing a unique setup using GPS devices and temperature probes fixed to several public transport units running all across the city. This is accompanied by an analysis of probability density functions (PDF) for heat waves based on recent climate data and climate projections. A dense net of 40 PM measurement sites is operated in order to obtain the spatial pattern of PM concentration as depending on meteorological condition and location. It is lined out how this climate related sub-projects interact with investigations on social networks, governance issues, buildings structure development and health outcome. Related to the later the chemical composition of PM is analyzed in more detail and related to the spatial patterns of health deficiencies. At a later stage City2020+ will propose new strategies based on cooperation from the fields of medicine, geography, sociology, history, civil engineering, and architecture for adapting the city for future needs. The Project CITY 2020+ is part of the interdisciplinary Project House HumTec (Human Sciences and Technology) at RWTH Aachen University funded by the Excellence Initiative of the German federal and state governments through the Deutsche Forschungsgemeinschaft (German Research Foundation, DFG).

Penguin heat-retention structures evolved in a greenhouse Earth.

PubMed

Thomas, Daniel B; Ksepka, Daniel T; Fordyce, R Ewan

2011-06-23

Penguins (Sphenisciformes) inhabit some of the most extreme environments on Earth. The 60+ Myr fossil record of penguins spans an interval that witnessed dramatic shifts in Cenozoic ocean temperatures and currents, indicating a long interplay between penguin evolution and environmental change. Perhaps the most celebrated example is the successful Late Cenozoic invasion of glacial environments by crown clade penguins. A major adaptation that allows penguins to forage in cold water is the humeral arterial plexus, a vascular counter-current heat exchanger (CCHE) that limits heat loss through the flipper. Fossil evidence reveals that the humeral plexus arose at least 49 Ma during a 'Greenhouse Earth' interval. The evolution of the CCHE is therefore unrelated to global cooling or development of polar ice sheets, but probably represents an adaptation to foraging in subsurface waters at temperate latitudes. As global climate cooled, the CCHE was key to invasion of thermally more demanding environments associated with Antarctic ice sheets.

Persistent cold air outbreaks over North America in a warming climate

DOE PAGES

Gao, Yang; Leung, L. Ruby; Lu, Jian; ...

2015-03-30

This study examines future changes of cold air outbreaks (CAO) using a multi-model ensemble of global climate simulations from the Coupled Model Intercomparison Project Phase 5 as well as regional high resolution climate simulations. In the future, while robust decrease of CAO duration dominates in most regions, the magnitude of decrease over northwestern U.S. is much smaller than the surrounding regions. We identified statistically significant increases in sea level pressure during CAO events centering over Yukon, Alaska, and Gulf of Alaska that advects continental cold air to northwestern U.S., leading to blocking and CAO events. Changes in large scale circulationmore » contribute to about 50% of the enhanced sea level pressure anomaly conducive to CAO in northwestern U.S. in the future. High resolution regional simulations revealed potential contributions of increased existing snowpack to increased CAO in the near future over the Rocky Mountain, southwestern U.S., and Great Lakes areas through surface albedo effects, despite winter mean snow water equivalent decreases in the future. Overall, the multi-model projections emphasize that cold extremes do not completely disappear in a warming climate. Concomitant with the relatively smaller reduction in CAO events in northwestern U.S., the top 5 most extreme CAO events may still occur in the future, and wind chill warning will continue to have societal impacts in that region.« less

Diurnal and seasonal variations of greenhouse gas emissions from a naturally ventilated dairy barn in a cold region

NASA Astrophysics Data System (ADS)

Huang, Dandan; Guo, Huiqing

2018-01-01

Carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) emissions were quantified for a naturally ventilated free-stall dairy barn in the Canadian Prairies climate through continuous measurements for a year from February 2015 to January 2016, with ventilation rate estimated by a CO2 mass balance method. The results were categorized into seasonal emission profiles with monthly data measured on a typical day, and diurnal profiles in cold (January), warm (July), and mild seasons (October) of all three gases. Seasonal CO2, CH4, and N2O concentrations greatly fluctuated within ranges of 593-2433 ppm, 15-152 ppm, and 0.32-0.40 ppm, respectively, with obviously higher concentrations in the cold season. Emission factors of the three gases were summarized: seasonal N2O emission varied between 0.5 and 10 μg s-1 AU-1 with lower emission in the cold season, while seasonal CO2 and CH4 emissions were within narrow ranges of 112-119 mg s-1 AU-1 and 2.5-3.5 mg s-1 AU-1. The result suggested a lower enteric CH4 emission for dairy cows than that estimated by Environment Canada (2014). Significant diurnal effects (P < 0.05) were observed for CH4 emissions in all seasons with higher emissions in the afternoons and evenings. The total greenhouse gas (GHG) emission, which was calculated by summing the three GHG in CO2 equivalent, was mainly contributed by CO2 and CH4 emissions and showed no significant seasonal variations (P > 0.05), but obvious diurnal variations in all seasons. In comparison with previous studies, it was found that the dairy barn in a cold region climate with smaller vent openings had relatively higher indoor CO2 and CH4 concentrations, but comparable CO2 and CH4 emissions to most previous studies. Besides, ventilation rate, temperature, and relative humidity all significantly affected the three gas concentrations with the outdoor temperature being the most relevant factor (P < 0.01); however, they showed less or no statistical relations to emissions.

Snow mass and river flows modelled using GRACE total water storage observations

NASA Astrophysics Data System (ADS)

Wang, S.

2017-12-01

Snow mass and river flow measurements are difficult and less accurate in cold regions due to the hash environment. Floods in cold regions are commonly a result of snowmelt during the spring break-up. Flooding is projected to increase with climate change in many parts of the world. Forecasting floods from snowmelt remains a challenge due to scarce and quality issues in basin-scale snow observations and lack of knowledge for cold region hydrological processes. This study developed a model for estimating basin-level snow mass (snow water equivalent SWE) and river flows using the total water storage (TWS) observations from the Gravity Recovery and Climate Experiment (GRACE) satellite mission. The SWE estimation is based on mass balance approach which is independent of in situ snow gauge observations, thus largely eliminates the limitations and uncertainties with traditional in situ or remote sensing snow estimates. The model forecasts river flows by simulating surface runoff from snowmelt and the corresponding baseflow from groundwater discharge. Snowmelt is predicted using a temperature index model. Baseflow is predicted using a modified linear reservoir model. The model also quantifies the hysteresis between the snowmelt and the streamflow rates, or the lump time for water travel in the basin. The model was applied to the Red River Basin, the Mackenzie River Basin, and the Hudson Bay Lowland Basins in Canada. The predicted river flows were compared with the observed values at downstream hydrometric stations. The results were also compared to that for the Lower Fraser River obtained in a separate study to help better understand the roles of environmental factors in determining flood and their variations with different hydroclimatic conditions. This study advances the applications of space-based time-variable gravity measurements in cold region snow mass estimation, river flow and flood forecasting. It demonstrates a relatively simple method that only needs GRACE TWS and temperature data for river flow or flood forecasting. The model can be particularly useful for regions with spare observation networks, and can be used in combination with other available methods to help improve the accuracy in river flow and flood forecasting over cold regions.

Local adaptations to frost in marginal and central populations of the dominant forest tree Fagus sylvatica L. as affected by temperature and extreme drought in common garden experiments.

PubMed

Kreyling, Juergen; Buhk, Constanze; Backhaus, Sabrina; Hallinger, Martin; Huber, Gerhard; Huber, Lukas; Jentsch, Anke; Konnert, Monika; Thiel, Daniel; Wilmking, Martin; Beierkuhnlein, Carl

2014-03-01

Local adaptations to environmental conditions are of high ecological importance as they determine distribution ranges and likely affect species responses to climate change. Increased environmental stress (warming, extreme drought) due to climate change in combination with decreased genetic mixing due to isolation may lead to stronger local adaptations of geographically marginal than central populations. We experimentally observed local adaptations of three marginal and four central populations of Fagus sylvaticaL., the dominant native forest tree, to frost over winter and in spring (late frost). We determined frost hardiness of buds and roots by the relative electrolyte leakage in two common garden experiments. The experiment at the cold site included a continuous warming treatment; the experiment at the warm site included a preceding summer drought manipulation. In both experiments, we found evidence for local adaptation to frost, with stronger signs of local adaptation in marginal populations. Winter frost killed many of the potted individuals at the cold site, with higher survival in the warming treatment and in those populations originating from colder environments. However, we found no difference in winter frost tolerance of buds among populations, implying that bud survival was not the main cue for mortality. Bud late frost tolerance in April differed between populations at the warm site, mainly because of phenological differences in bud break. Increased spring frost tolerance of plants which had experienced drought stress in the preceding summer could also be explained by shifts in phenology. Stronger local adaptations to climate in geographically marginal than central populations imply the potential for adaptation to climate at range edges. In times of climate change, however, it needs to be tested whether locally adapted populations at range margins can successfully adapt further to changing conditions.

Effective climate refugia for salmon in a changing world

EPA Science Inventory

Climate change threatens to create fundamental shifts in in the distributions and abundances of endothermic organisms such as cold-water salmon and trout species (salmonids). Recently published projected declines in salmonid distributions under future climates range from modest t...

Climatic niche and neutral genetic diversity of the six Iberian pine species: a retrospective and prospective view.

PubMed

Soto, A; Robledo-Arnuncio, J J; González-Martínez, S C; Smouse, P E; Alía, R

2010-04-01

Quaternary climatic fluctuations have left contrasting historical footprints on the neutral genetic diversity patterns of existing populations of different tree species. We should expect the demography, and consequently the neutral genetic structure, of taxa less tolerant to particular climatic extremes to be more sensitive to long-term climate fluctuations. We explore this hypothesis here by sampling all six pine species found in the Iberian Peninsula (2464 individuals, 105 populations), using a common set of chloroplast microsatellite markers, and by looking at the association between neutral genetic diversity and species-specific climatic requirements. We found large variation in neutral genetic diversity and structure among Iberian pines, with cold-enduring mountain species (Pinus uncinata, P. sylvestris and P. nigra) showing substantially greater diversity than thermophilous taxa (P. pinea and P. halepensis). Within species, we observed a significant positive correlation between population genetic diversity and summer precipitation for some of the mountain pines. The observed pattern is consistent with the hypotheses that: (i) more thermophilous species have been subjected to stronger demographic fluctuations in the past, as a consequence of their maladaptation to recurrent glacial cold stages; and (ii) altitudinal migrations have allowed the maintenance of large effective population sizes and genetic variation in cold-tolerant species, especially in more humid regions. In the light of these results and hypotheses, we discuss some potential genetic consequences of impending climate change.

Comparison of Shoulder Range of Motion, Strength, and Playing Time in Uninjured High School Baseball Pitchers Who Reside in Warm- and Cold-Weather Climates

PubMed Central

Kaplan, Kevin M.; ElAttrache, Neal S.; Jobe, Frank W.; Morrey, Bernard F.; Kaufman, Kenton R.; Hurd, Wendy J.

2014-01-01

Background There is an assumption that baseball athletes who reside in warm-weather climates experience larger magnitude adaptations in throwing shoulder motion and strength compared with their peers who reside in cold-weather climates. Hypotheses (1) The warm-weather climate (WWC) group would exhibit more pronounced shoulder motion and strength adaptations than the cold-weather climate (CWC) group, and (2) the WWC group would participate in pitching activities for a greater proportion of the year than the CWC group, with the time spent pitching predicting throwing shoulder motion and strength in both groups. Study Design Cross-sectional study; Level of evidence, 3. Methods One hundred uninjured high school pitchers (50 each WWC, CWC) were recruited. Rotational shoulder motion and isometric strength were measured and participants reported the number of months per year they pitched. To identify differences between groups, t tests were performed; linear regression was used to determine the influence of pitching volume on shoulder motion and strength. Results The WWC group pitched more months per year than athletes from the CWC group, with the number of months spent pitching negatively related to internal rotation motion and external rotation strength. The WWC group exhibited greater shoulder range of motion in all planes compared with the CWC group, as well as significantly lower external rotation strength and external/internal rotation strength ratios. There was no difference in internal rotation strength between groups, nor a difference in the magnitude of side-to-side differences for strength or motion measures. Conclusion Athletes who reside in cold- and warm-weather climates exhibit differences in throwing shoulder motion and strength, related in part to the number of months spent participating in pitching activities. The amount of time spent participating in pitching activities and the magnitude of range of motion and strength adaptations in athletes who reside in warm-weather climates may make these athletes more susceptible to throwing-related injuries. PMID:21051421

Climate variability and the energetic pathways of evolution: the origin of endothermy in mammals and birds.

PubMed

Portner, Hans O

2004-01-01

Large-scale climate oscillations in earth's history have influenced the directions of evolution, last but not least, through mass extinction events. This analysis tries to identify some unifying forces behind the course of evolution that favored an increase in organismic complexity and performance, paralleled by an increase in energy turnover, and finally led to endothermy. The analysis builds on the recent concept of oxygen-limited thermal tolerance and on the hypothesis that unifying principles exist in the temperature-dependent biochemical design of the eukaryotic cell in animals. The comparison of extant water-breathing and air-breathing animal species from various climates provides a cause-and-effect understanding of the trade-offs and constraints in thermal adaptation and their energetic consequences. It is hypothesized that the high costs of functional adaptation to fluctuating temperatures, especially in the cold (cold eurythermy), cause an increase in energy turnover and, at the same time, mobility and agility. These costs are associated with elevated mitochondrial capacities at minimized levels of activation enthalpies for proton leakage. Cold eurythermy is seen as a precondition for the survival of evolutionary crises elicited by repeated cooling events during extreme climate fluctuations. The costs of cold eurythermy appear as the single most important reason why metazoan evolution led to life forms with high energy turnover. They also explain why dinosaurs were able to live in subpolar climates. Finally, they give insight into the pathways, benefits, and trade-offs involved in the evolution of constant, elevated body temperature maintained by endothermy. Eurythermy, which encompasses cold tolerance, is thus hypothesized to be the "missing link" between ectothermy and endothermy. Body temperatures between 32 degrees and 42 degrees C in mammals and birds then result from trade-offs between the limiting capacities of ventilation and circulation and the evolutionary trend to maximize performance at the warm end of the thermal tolerance window.

Climate change effects on human health: projections of temperature-related mortality for the UK during the 2020s, 2050s and 2080s.

PubMed

Hajat, Shakoor; Vardoulakis, Sotiris; Heaviside, Clare; Eggen, Bernd

2014-07-01

The most direct way in which climate change is expected to affect public health relates to changes in mortality rates associated with exposure to ambient temperature. Many countries worldwide experience annual heat-related and cold-related deaths associated with current weather patterns. Future changes in climate may alter such risks. Estimates of the likely future health impacts of such changes are needed to inform public health policy on climate change in the UK and elsewhere. Time-series regression analysis was used to characterise current temperature-mortality relationships by region and age group. These were then applied to the local climate and population projections to estimate temperature-related deaths for the UK by the 2020s, 2050s and 2080s. Greater variability in future temperatures as well as changes in mean levels was modelled. A significantly raised risk of heat-related and cold-related mortality was observed in all regions. The elderly were most at risk. In the absence of any adaptation of the population, heat-related deaths would be expected to rise by around 257% by the 2050s from a current annual baseline of around 2000 deaths, and cold-related mortality would decline by 2% from a baseline of around 41 000 deaths. The cold burden remained higher than the heat burden in all periods. The increased number of future temperature-related deaths was partly driven by projected population growth and ageing. Health protection from hot weather will become increasingly necessary, and measures to reduce cold impacts will also remain important in the UK. The demographic changes expected this century mean that the health protection of the elderly will be vital. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Thermal responses from repeated exposures to severe cold with intermittent warmer temperatures.

PubMed

Ozaki, H; Enomoto-Koshimizu, H; Tochihara, Y; Nakamura, K

1998-09-01

This study was conducted to evaluate physiological reaction and manual performance during exposure to warm (30 degrees C) and cool (10 degrees C) environments after exposure to very low temperatures (-25 degrees C). Furthermore, this experiment was conducted to study whether it is desirable to remove cold-protective jackets in warmer rooms after severe cold exposure. Eight male students remained in an extremely cold room for 20 min, after which they transferred into either the warm room or the cool room for 20 min. This pattern was repeated three times, and the total cold exposure time was 60 min. In the warm and cool rooms, the subjects either removed their cold-protective jackets (Condition A), or wore them continuously (Condition B). Rectal temperature, skin temperatures, manual performance, blood pressure, thermal, comfort and pain sensations were measured during the experiment. The effects of severe cold on almost all measurements in the cool (10 degrees C) environment were greater than those in the warm (30 degrees C) environment under both clothing conditions. The effects of severe cold on all measurements under Condition A except rectal temperature and toe skin temperature were significantly greater than those under Condition B in the cool environment but, not at all differences between Condition A and Condition B in the warm environments were significant. It was recognized that to remove cold-protective jackets in the cool room (10 degrees C) after severe cold exposure promoted the effects of severe cold. When rewarming in the warm resting room (30 degrees C), the physiological and psychological responses and manual performance were not influenced by the presence or absence of cold-protective clothing. These results suggest that it is necessary for workers to make sure to rewarm in the warm room outside of the cold storage and continue to wear cold-protective clothing in the cool room.

Detecting regional patterns of changing CO2 flux in Alaska

PubMed Central

Parazoo, Nicholas C.; Wofsy, Steven C.; Koven, Charles D.; Sweeney, Colm; Lawrence, David M.; Lindaas, Jakob; Chang, Rachel Y.-W.; Miller, Charles E.

2016-01-01

With rapid changes in climate and the seasonal amplitude of carbon dioxide (CO2) in the Arctic, it is critical that we detect and quantify the underlying processes controlling the changing amplitude of CO2 to better predict carbon cycle feedbacks in the Arctic climate system. We use satellite and airborne observations of atmospheric CO2 with climatically forced CO2 flux simulations to assess the detectability of Alaskan carbon cycle signals as future warming evolves. We find that current satellite remote sensing technologies can detect changing uptake accurately during the growing season but lack sufficient cold season coverage and near-surface sensitivity to constrain annual carbon balance changes at regional scale. Airborne strategies that target regular vertical profile measurements within continental interiors are more sensitive to regional flux deeper into the cold season but currently lack sufficient spatial coverage throughout the entire cold season. Thus, the current CO2 observing network is unlikely to detect potentially large CO2 sources associated with deep permafrost thaw and cold season respiration expected over the next 50 y. Although continuity of current observations is vital, strategies and technologies focused on cold season measurements (active remote sensing, aircraft, and tall towers) and systematic sampling of vertical profiles across continental interiors over the full annual cycle are required to detect the onset of carbon release from thawing permafrost. PMID:27354511

Detecting regional patterns of changing CO 2 flux in Alaska

DOE PAGES

Parazoo, Nicholas C.; Commane, Roisin; Wofsy, Steven C.; ...

2016-06-27

With rapid changes in climate and the seasonal amplitude of carbon dioxide (CO 2) in the Arctic, it is critical that we detect and quantify the underlying processes controlling the changing amplitude of CO 2 to better predict carbon cycle feedbacks in the Arctic climate system. We use satellite and airborne observations of atmospheric CO 2 with climatically forced CO 2 flux simulations to assess the detectability of Alaskan carbon cycle signals as future warming evolves. We find that current satellite remote sensing technologies can detect changing uptake accurately during the growing season but lack sufficient cold season coverage andmore » near-surface sensitivity to constrain annual carbon balance changes at regional scale. Airborne strategies that target regular vertical profile measurements within continental interiors are more sensitive to regional flux deeper into the cold season but currently lack sufficient spatial coverage throughout the entire cold season. Thus, the current CO 2 observing network is unlikely to detect potentially large CO 2 sources associated with deep permafrost thaw and cold season respiration expected over the next 50 y. In conclusion, although continuity of current observations is vital, strategies and technologies focused on cold season measurements (active remote sensing, aircraft, and tall towers) and systematic sampling of vertical profiles across continental interiors over the full annual cycle are required to detect the onset of carbon release from thawing permafrost.« less

Cold Climate and Retrofit Applications for Air-to-Air Heat Pumps

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baxter, Van D

2015-01-01

Air source heat pumps (ASHP) including air-to-air ASHPs are easily applied to buildings almost anywhere for new construction as well as retrofits or renovations. They are widespread in milder climate regions but their use in cold regions is hampered due to low heating efficiency and capacity at cold outdoor temperatures. Retrofitting air-to-air ASHPs to existing buildings is relatively easy if the building already has an air distribution system. For buildings without such systems alternative approaches are necessary. Examples are ductless, minisplit heat pumps or central heat pumps coupled to small diameter, high velocity (SDHV) air distribution systems. This article presentsmore » two subjects: 1) a summary of R&D investigations aimed at improving the cold weather performance of ASHPs, and 2) a brief discussion of building retrofit options using air-to-air ASHP systems.« less

Role of Acclimatization in Weather-Related Human Mortality During the Transition Seasons of Autumn and Spring in a Thermally Extreme Mid-Latitude Continental Climate

PubMed Central

de Freitas, Christopher R.; Grigorieva, Elena A.

2015-01-01

Human mortality is closely related to natural climate-determined levels of thermal environmental stress and the resulting thermophysiological strain. Most climate-mortality research has focused on seasonal extremes during winter and summer when mortality is the highest, while relatively little attention has been paid to mortality during the transitional seasons of autumn and spring. The body acclimatizes to heat in the summer and cold in winter and readjusts through acclimatization during the transitions between the two during which time the body experiences the thermophysiological strain of readjustment. To better understand the influences of weather on mortality through the acclimatization process, the aim here is to examine the periods that link very cold and very warms seasons. The study uses the Acclimatization Thermal Strain Index (ATSI), which is a comparative measure of short-term thermophysiological impact on the body. ATSI centers on heat exchange with the body’s core via the respiratory system, which cannot be protected. The analysis is based on data for a major city in the climatic region of the Russian Far East characterized by very hot summers and extremely cold winters. The results show that although mortality peaks in winter (January) and is at its lowest in summer (August), there is not a smooth rise through autumn nor a smooth decline through spring. A secondary peak occurs in autumn (October) with a smaller jump in May. This suggests the acclimatization from warm-to-cold produces more thermophysiological strain than the transition from cold-to-warm. The study shows that ATSI is a useful metric for quantifying the extent to which biophysical adaptation plays a role in increased strain on the body during re-acclimatization and for this reason is a more appropriate climatic indictor than air temperature alone. The work gives useful bioclimatic information on risks involved in transitional seasons in regions characterized by climatic extremes. This could be handy in planning and managing health services to the public and measures that might be used to help mitigate impacts. PMID:26703633

Aquifer Thermal Energy Storage for Seasonal Thermal Energy Balance

NASA Astrophysics Data System (ADS)

Rostampour, Vahab; Bloemendal, Martin; Keviczky, Tamas

2017-04-01

Aquifer Thermal Energy Storage (ATES) systems allow storing large quantities of thermal energy in subsurface aquifers enabling significant energy savings and greenhouse gas reductions. This is achieved by injection and extraction of water into and from saturated underground aquifers, simultaneously. An ATES system consists of two wells and operates in a seasonal mode. One well is used for the storage of cold water, the other one for the storage of heat. In warm seasons, cold water is extracted from the cold well to provide cooling to a building. The temperature of the extracted cold water increases as it passes through the building climate control systems and then gets simultaneously, injected back into the warm well. This procedure is reversed during cold seasons where the flow direction is reversed such that the warmer water is extracted from the warm well to provide heating to a building. From the perspective of building climate comfort systems, an ATES system is considered as a seasonal storage system that can be a heat source or sink, or as a storage for thermal energy. This leads to an interesting and challenging optimal control problem of the building climate comfort system that can be used to develop a seasonal-based energy management strategy. In [1] we develop a control-oriented model to predict thermal energy balance in a building climate control system integrated with ATES. Such a model however cannot cope with off-nominal but realistic situations such as when the wells are completely depleted, or the start-up phase of newly installed wells, etc., leading to direct usage of aquifer ambient temperature. Building upon our previous work in [1], we here extend the mathematical model for ATES system to handle the above mentioned more realistic situations. Using our improved models, one can more precisely predict system behavior and apply optimal control strategies to manage the building climate comfort along with energy savings and greenhouse gas reductions. [1] V. Rostampour and T. Keviczky, "Probabilistic Energy Management for Building Climate Comfort in Smart Thermal Grids with Seasonal Storage Systems," arXiv [math.OC], 10-Nov-2016.

Role of Acclimatization in Weather-Related Human Mortality During the Transition Seasons of Autumn and Spring in a Thermally Extreme Mid-Latitude Continental Climate.

PubMed

de Freitas, Christopher R; Grigorieva, Elena A

2015-11-26

Human mortality is closely related to natural climate-determined levels of thermal environmental stress and the resulting thermophysiological strain. Most climate-mortality research has focused on seasonal extremes during winter and summer when mortality is the highest, while relatively little attention has been paid to mortality during the transitional seasons of autumn and spring. The body acclimatizes to heat in the summer and cold in winter and readjusts through acclimatization during the transitions between the two during which time the body experiences the thermophysiological strain of readjustment. To better understand the influences of weather on mortality through the acclimatization process, the aim here is to examine the periods that link very cold and very warms seasons. The study uses the Acclimatization Thermal Strain Index (ATSI), which is a comparative measure of short-term thermophysiological impact on the body. ATSI centers on heat exchange with the body’s core via the respiratory system, which cannot be protected. The analysis is based on data for a major city in the climatic region of the Russian Far East characterized by very hot summers and extremely cold winters. The results show that although mortality peaks in winter (January) and is at its lowest in summer (August), there is not a smooth rise through autumn nor a smooth decline through spring. A secondary peak occurs in autumn (October) with a smaller jump in May. This suggests the acclimatization from warm-to-cold produces more thermophysiological strain than the transition from cold-to-warm. The study shows that ATSI is a useful metric for quantifying the extent to which biophysical adaptation plays a role in increased strain on the body during re-acclimatization and for this reason is a more appropriate climatic indictor than air temperature alone. The work gives useful bioclimatic information on risks involved in transitional seasons in regions characterized by climatic extremes. This could be handy in planning and managing health services to the public and measures that might be used to help mitigate impacts.

Late Pliocene/Early Pleistocene environments inferred from the Lake El'gygytgyn pollen record

NASA Astrophysics Data System (ADS)

Andreev, Andrei; Wennrich, Volker; Tarasov, Pavel; Raschke (Morozova), Elena; Brigham-Grette, Julie; Nowaczyk, Norbert; Melles, Martin

2014-05-01

The Arctic is known to play a crucial role within the global climate system. The mid-Pliocene (3-3.5 Ma) is considered to be the most probable scenario of the future climate changes. However, reliable climate projections are hampered by the complexity of the underlying natural variability and feedback mechanisms. An important prerequisite for the validation and improvement of the future projections is a better understanding of the long-term environmental history of the Arctic. Unfortunately, formation of continuous paleoenvironmental records in the Arctic was widely restricted due to repeated glaciations. Continuous sequences that penetrate the entire Quaternary and further into the Pliocene are highly desired and would enable to validate the temperature rise during the mid-Pliocene that was proposed by former studies. Such a record has now become available from Lake El'gygytgyn (67º30'N, 172º05E') located in a meteorite impact crater in north-eastern Siberia. The impact nearly 3.6 Ma ago formed an 18 km wide hole in the ground that then filled with water. The retrieved lake sediments have trapped pollen from a several thousand square-kilometer source area providing reliable insights into regional and over-regional millennial-scale vegetation and climate changes of the Arctic since the Pliocene. The ''El'gygytgyn Drilling Project" of ICDP has completed three holes in the center of the lake, penetrating about 318 m thick lake sediments and about 200 m of the impact rocks below. Because of its unusual origin and high-latitude setting in western Beringia, scientific drilling at Lake El'gygytgyn offered unique opportunities for paleoclimate research, allowing time-continuous climatic and environmental reconstructions back into the Pliocene. Late Pliocene and Early Pleistocene pollen assemblages can be subdivided into 55 pollen zones, which reflect the main environmental fluctuations in the region 3.55-2.15 Ma BP. Pollen-based climate reconstructions show that conditions in the study area were the warmest about 3.55-3.4 Ma BP when spruce-pine-fir-hemlock-larch-Pseudotsuga forests dominated in nowadays tundra area. After ca 3.4 Ma BP dark coniferous taxa gradually disappeared from the vegetation. Very pronounced environmental changes are revealed about ca 3.35-3.275 Ma BP when treeless tundra and steppe habitats dominated. Treeless and shrubby environments are also indicative after ca 2.6 Ma. Dry and cold climate conditions were similar to those during the Late Pleistocene. The Early Pleistocene sediments contain pollen assemblages reflecting alternation of treeless intervals with cold and dry climate and warmer intervals when larch forests with stone pines, shrub alders and birches were also common in the region. Very dry environments are revealed after ca 2.175 Ma BP. High amounts of green algae colonies (Botryococcus) in the studied sediments point to shallow-water conditions ca 2.55, 2.45, and ca 2.175 Ma BP. Thus, pollen studies show that sediments accumulated in Lake El'gygytgyn are an excellent archive of environmental changes since 3.55 Myr BP. The record well reflects main regional paleoenvironmental fluctuations. The further high-resolution palynological study of the core will reveal climate fluctuations inside the main glacial/interglacial intervals and will give the first continuous and detailed scheme of environmental changes for a whole Arctic.

Evaluation of the tourism climate in the Hexi Corridor of northwest China's Gansu Province during 1980-2012

NASA Astrophysics Data System (ADS)

Zhang, Fuxian; Zhang, Mingjun; Wang, Shengjie; Qiang, Fang; Che, Yanjun; Wang, Jie

2017-08-01

As a pivotal section of the Silk Road in northwest China, the Hexi Corridor is a popular tourist destination. In this study, the tourism climate conditions in this region were discussed using the Physiologically Equivalent Temperature (PET) and the Climate-Tourism/Transfer-information-Scheme (CTIS) from 1980 to 2012. Overall, cold or cool stress was prevalent in the area, and the optimal travel period was from May to September. With global warming, the annual numbers of cumulative days with relatively cold conditions decreased, and the annual numbers of cumulative days with comfortable and relatively hot conditions increased. Two typical stations, Wushaoling and Dunhuang, were compared and analysed for their tourism climate information according to the frequency of PET and CTIS conditions, respectively. In addition, regional variations in the tourism climate conditions based on geographic information systems (GIS) were investigated during the optimal travel period.

Finalize field testing of cold climate heat pump (CCHP) based on tandem vapor injection compressors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shen, Bo; Baxter, Van D.; Abdelaziz, Omar

2017-03-01

This report describes the system diagram and control algorithm of a prototype air-source cold climate heat pump (CCHP) using tandem vapor injection (VI) compressors. The prototype was installed in Fairbanks, Alaska and underwent field testing starting in 09/2016. The field testing results of the past six months, including compressor run time fractions, measured COPs and heating capacities, etc., are presented as a function of the ambient temperature. Two lessons learned are also reported.

In Situ Warming and Soil Venting to Enhance the Biodegradation of JP-4 in Cold Climates: A Critical Study and Analysis

DTIC Science & Technology

1995-12-01

1178-1180 (1991). Atlas , Ronald M. and Richard Bartha . Microbial Ecology : Fundamentals and Applications. 3d ed. Redwood City CA: The Benjamin/Cummings...technique called bioventing. In cold climates, in situ bioremediation is limited to the summer when soil temperatures are sufficient to support microbial ...actively warmed the soil -- warm water circulation and heat tape; the other passively warmed the plot with insulatory covers. Microbial respiration (02

New Insights on Hydro-Climate Feedback Processes over the Tropical Ocean from TRMM

NASA Technical Reports Server (NTRS)

Lau, William K. M.; Wu, H. T.; Li, Xiaofan; Sui, C. H.

2002-01-01

In this paper, we study hydro-climate feedback processes over the tropical oceans, by examining the relationships among large scale circulation and Tropical Rainfall Measuring Mission Microwave Imager-Sea Surface Temperature (TMI-SST), and a range of TRMM rain products including rain rate, cloud liquid water, precipitable water, cloud types and areal coverage, and precipitation efficiency. Results show that for a warm event (1998), the 28C threshold of convective precipitation is quite well defined over the tropical oceans. However, for a cold event (1999), the SST threshold is less well defined, especially over the central and eastern Pacific cold tongue, where stratiform rain occurs at much lower than 28 C. Precipitation rates and cloud liquid water are found to be more closely related to the large scale vertical motion than to the underlying SST. While total columnar water vapor is more strongly dependent on SST. For a large domain, over the eastern Pacific, we find that the areal extent of the cloudy region tends to shrink as the SST increases. Examination of the relationship between cloud liquid water and rain rate suggests that the residence time of cloud liquid water tends to be shorter, associated with higher precipitation efficiency in a warmer climate. It is hypothesized that the reduction in cloudy area may be influenced both by the shift in large scale cloud patterns in response to changes in large scale forcings, and possible increase in the cloud liquid water conversion to rain water in a warmer environment. Results of numerical experiments with the Goddard cloud resolving model to test the hypothesis will be discussed.

Validation of standard ASTM F2732 and comparison with ISO 11079 with respect to comfort temperature ratings for cold protective clothing.

PubMed

Gao, Chuansi; Lin, Li-Yen; Halder, Amitava; Kuklane, Kalev; Holmér, Ingvar

2015-01-01

American standard ASTM F2732 estimates the lowest environmental temperature for thermal comfort for cold weather protective clothing. International standard ISO 11079 serves the same purpose but expresses cold stress in terms of required clothing insulation for a given cold climate. The objective of this study was to validate and compare the temperature ratings using human subject tests at two levels of metabolic rates (2 and 4 MET corresponding to 116.4 and 232.8 W/m(2)). Nine young and healthy male subjects participated in the cold exposure at 3.4 and -30.6 °C. The results showed that both standards predict similar temperature ratings for an intrinsic clothing insulation of 1.89 clo and for 2 MET activity. The predicted temperature rating for 2 MET activity is consistent with test subjects' thermophysiological responses, perceived thermal sensation and thermal comfort. For 4 MET activity, however, the whole body responses were on the cold side, particularly the responses of the extremities. ASTM F2732 is also limited due to its omission and simplification of three climatic variables (air velocity, radiant temperature and relative humidity) and exposure time in the cold which are of practical importance. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Association of cold temperature and mortality and effect modification in the subtropical plateau monsoon climate of Yuxi, China.

PubMed

Ding, Zan; Li, Liujiu; Wei, Ruqin; Dong, Wenya; Guo, Pi; Yang, Shaoyi; Liu, Ju; Zhang, Qingying

2016-10-01

Consistent evidence has shown excess mortality associated with cold temperature, but some important details of the cold-mortality association (e.g. slope and threshold) have not been adequately investigated and few studies focused on the cold effect in high-altitude areas of developing countries. We attempted to quantify the cold effect on mortality, identify the details, and evaluate effect modification in the distinct subtropical plateau monsoon climate of Yuxi, a high plateau region in southwest China. From daily mortality and meteorological data during 2009-2014, we used a quasi-Poisson model combined with a "natural cubic spline-natural cubic spline" distributed lag non-linear model to estimate the temperature-mortality relationship and then a simpler "hockey-stick" model to investigate the cold effect and details. Cold temperature was associated with increased mortality, and the relative risk of cold effect (1st relative to 10th temperature percentile) on non-accidental, cardiovascular, and respiratory mortality for lag 0-21 days was 1.40 (95% confidence interval: 1.19-1.66), 1.61 (1.28-2.02), and 1.13 (0.78-1.64), respectively. A 1°C decrease below a cold threshold of 9.1°C (8th percentile) for lags 0-21 was associated with a 7.35% (3.75-11.09%) increase in non-accidental mortality. The cold-mortality association was not significantly affected by cause-specific mortality, gender, age, marital status, ethnicity, occupation, or previous history of hypertension. There is an adverse impact of cold on mortality in Yuxi, China, and a temperature of 9.1°C is an important cut-off for cold-related mortality for residents. Copyright © 2016 Elsevier Inc. All rights reserved.

Plasticity and local adaptation explain lizard cold tolerance.

PubMed

Card, Daren C; Schield, Drew R; Castoe, Todd A

2018-05-01

How does climate variation limit the range of species and what does it take for species to colonize new regions? In this issue of Molecular Ecology, Campbell-Staton et al. () address these broad questions by investigating cold tolerance adaptation in the green anole lizard (Anolis carolinensis) across a latitudinal transect. By integrating physiological data, gene expression data and acclimation experiments, the authors disentangle the mechanisms underlying cold adaptation. They first establish that cold tolerance adaptation in Anolis lizards follows the predictions of the oxygen- and capacity-limited thermal tolerance hypothesis, which states that organisms are limited by temperature thresholds at which oxygen supply cannot meet demand. They then explore the drivers of cold tolerance at a finer scale, finding evidence that northern populations are adapted to cooler thermal regimes and that both phenotypic plasticity and heritable genetic variation contribute to cold tolerance. The integration of physiological and gene expression data further highlights the varied mechanisms that drive cold tolerance adaptation in Anolis lizards, including both supply-side and demand-side adaptations that improve oxygen economy. Altogether, their work provides new insight into the physiological and genetic mechanisms underlying adaptation to new climatic niches and demonstrates that cold tolerance in northern lizard populations is achieved through the synergy of physiological plasticity and local genetic adaptation for thermal performance. © 2018 John Wiley & Sons Ltd.

Cold season emissions dominate the Arctic tundra methane budget

NASA Astrophysics Data System (ADS)

Zona, Donatella; Gioli, Beniamino; Commane, Róisín; Lindaas, Jakob; Wofsy, Steven C.; Miller, Charles E.; Dinardo, Steven J.; Dengel, Sigrid; Sweeney, Colm; Karion, Anna; Chang, Rachel Y.-W.; Henderson, John M.; Murphy, Patrick C.; Goodrich, Jordan P.; Moreaux, Virginie; Liljedahl, Anna; Watts, Jennifer D.; Kimball, John S.; Lipson, David A.; Oechel, Walter C.

2016-01-01

Arctic terrestrial ecosystems are major global sources of methane (CH4); hence, it is important to understand the seasonal and climatic controls on CH4 emissions from these systems. Here, we report year-round CH4 emissions from Alaskan Arctic tundra eddy flux sites and regional fluxes derived from aircraft data. We find that emissions during the cold season (September to May) account for ≥50% of the annual CH4 flux, with the highest emissions from noninundated upland tundra. A major fraction of cold season emissions occur during the "zero curtain" period, when subsurface soil temperatures are poised near 0 °C. The zero curtain may persist longer than the growing season, and CH4 emissions are enhanced when the duration is extended by a deep thawed layer as can occur with thick snow cover. Regional scale fluxes of CH4 derived from aircraft data demonstrate the large spatial extent of late season CH4 emissions. Scaled to the circumpolar Arctic, cold season fluxes from tundra total 12 ± 5 (95% confidence interval) Tg CH4 y-1, ∼25% of global emissions from extratropical wetlands, or ∼6% of total global wetland methane emissions. The dominance of late-season emissions, sensitivity to soil environmental conditions, and importance of dry tundra are not currently simulated in most global climate models. Because Arctic warming disproportionally impacts the cold season, our results suggest that higher cold-season CH4 emissions will result from observed and predicted increases in snow thickness, active layer depth, and soil temperature, representing important positive feedbacks on climate warming.

Cold season emissions dominate the Arctic tundra methane budget.

PubMed

Zona, Donatella; Gioli, Beniamino; Commane, Róisín; Lindaas, Jakob; Wofsy, Steven C; Miller, Charles E; Dinardo, Steven J; Dengel, Sigrid; Sweeney, Colm; Karion, Anna; Chang, Rachel Y-W; Henderson, John M; Murphy, Patrick C; Goodrich, Jordan P; Moreaux, Virginie; Liljedahl, Anna; Watts, Jennifer D; Kimball, John S; Lipson, David A; Oechel, Walter C

2016-01-05

Arctic terrestrial ecosystems are major global sources of methane (CH4); hence, it is important to understand the seasonal and climatic controls on CH4 emissions from these systems. Here, we report year-round CH4 emissions from Alaskan Arctic tundra eddy flux sites and regional fluxes derived from aircraft data. We find that emissions during the cold season (September to May) account for ≥ 50% of the annual CH4 flux, with the highest emissions from noninundated upland tundra. A major fraction of cold season emissions occur during the "zero curtain" period, when subsurface soil temperatures are poised near 0 °C. The zero curtain may persist longer than the growing season, and CH4 emissions are enhanced when the duration is extended by a deep thawed layer as can occur with thick snow cover. Regional scale fluxes of CH4 derived from aircraft data demonstrate the large spatial extent of late season CH4 emissions. Scaled to the circumpolar Arctic, cold season fluxes from tundra total 12 ± 5 (95% confidence interval) Tg CH4 y(-1), ∼ 25% of global emissions from extratropical wetlands, or ∼ 6% of total global wetland methane emissions. The dominance of late-season emissions, sensitivity to soil environmental conditions, and importance of dry tundra are not currently simulated in most global climate models. Because Arctic warming disproportionally impacts the cold season, our results suggest that higher cold-season CH4 emissions will result from observed and predicted increases in snow thickness, active layer depth, and soil temperature, representing important positive feedbacks on climate warming.

Cold season emissions dominate the Arctic tundra methane budget

PubMed Central

Zona, Donatella; Gioli, Beniamino; Lindaas, Jakob; Wofsy, Steven C.; Miller, Charles E.; Dinardo, Steven J.; Dengel, Sigrid; Sweeney, Colm; Karion, Anna; Chang, Rachel Y.-W.; Henderson, John M.; Murphy, Patrick C.; Goodrich, Jordan P.; Moreaux, Virginie; Liljedahl, Anna; Watts, Jennifer D.; Kimball, John S.; Lipson, David A.; Oechel, Walter C.

2016-01-01

Arctic terrestrial ecosystems are major global sources of methane (CH4); hence, it is important to understand the seasonal and climatic controls on CH4 emissions from these systems. Here, we report year-round CH4 emissions from Alaskan Arctic tundra eddy flux sites and regional fluxes derived from aircraft data. We find that emissions during the cold season (September to May) account for ≥50% of the annual CH4 flux, with the highest emissions from noninundated upland tundra. A major fraction of cold season emissions occur during the “zero curtain” period, when subsurface soil temperatures are poised near 0 °C. The zero curtain may persist longer than the growing season, and CH4 emissions are enhanced when the duration is extended by a deep thawed layer as can occur with thick snow cover. Regional scale fluxes of CH4 derived from aircraft data demonstrate the large spatial extent of late season CH4 emissions. Scaled to the circumpolar Arctic, cold season fluxes from tundra total 12 ± 5 (95% confidence interval) Tg CH4 y−1, ∼25% of global emissions from extratropical wetlands, or ∼6% of total global wetland methane emissions. The dominance of late-season emissions, sensitivity to soil environmental conditions, and importance of dry tundra are not currently simulated in most global climate models. Because Arctic warming disproportionally impacts the cold season, our results suggest that higher cold-season CH4 emissions will result from observed and predicted increases in snow thickness, active layer depth, and soil temperature, representing important positive feedbacks on climate warming. PMID:26699476

Cold season emissions dominate the Arctic tundra methane budget

DOE PAGES

Zona, Donatella; Gioli, Beniamino; Commane, Róisín; ...

2015-12-22

Arctic terrestrial ecosystems are major global sources of methane (CH 4); hence, it is important to understand the seasonal and climatic controls on CH 4 emissions from these systems. Here, we report year-round CH 4 emissions from Alaskan Arctic tundra eddy flux sites and regional fluxes derived from aircraft data. We find that emissions during the cold season (September to May) account for ≥ 50% of the annual CH 4 flux, with the highest emissions from noninundated upland tundra. A major fraction of cold season emissions occur during the “zero curtain” period, when subsurface soil temperatures are poised near 0more » °C. The zero curtain may persist longer than the growing season, and CH 4 emissions are enhanced when the duration is extended by a deep thawed layer as can occur with thick snow cover. Regional scale fluxes of CH 4 derived from aircraft data demonstrate the large spatial extent of late season CH 4 emissions. Scaled to the circumpolar Arctic, cold season fluxes from tundra total 12 ± 5 (95% confidence interval) Tg CH 4 y –1, ~25% of global emissions from extratropical wetlands, or ~6% of total global wetland methane emissions. Here, the dominance of late-season emissions, sensitivity to soil environmental conditions, and importance of dry tundra are not currently simulated in most global climate models. Because Arctic warming disproportionally impacts the cold season, our results suggest that higher cold-season CH 4 emissions will result from observed and predicted increases in snow thickness, active layer depth, and soil temperature, representing important positive feedbacks on climate warming.« less

Cold-related mortality vs heat-related mortality in a changing climate: A case study in Vilnius (Lithuania).

PubMed

Martinez, Gerardo Sanchez; Diaz, Julio; Hooyberghs, Hans; Lauwaet, Dirk; De Ridder, Koen; Linares, Cristina; Carmona, Rocio; Ortiz, Cristina; Kendrovski, Vladimir; Adamonyte, Dovile

2018-06-21

Direct health effects of extreme temperatures are a significant environmental health problem in Lithuania, and could worsen further under climate change. This paper attempts to describe the change in environmental temperature conditions that the urban population of Vilnius could experience under climate change, and the effects such change could have on excess heat-related and cold-related mortality in two future periods within the 21st century. We modelled the urban climate of Vilnius for the summer and winter seasons during a sample period (2009-2015) and projected summertime and wintertime daily temperatures for two prospective periods, one in the near (2030-2045) and one in the far future (2085-2100), under the Representative Concentration Pathway (RCP) 8.5. We then analysed the historical relationship between temperature and mortality for the period 2009-2015, and estimated the projected mortality in the near future and far future periods under a changing climate and population, assuming alternatively no acclimatisation and acclimatisation to heat and cold based on a constant-percentile threshold temperature. During the sample period 2009-2015 in summertime we observed an increase in daily mortality from a maximum daily temperature of 30 °C (the 96th percentile of the series), with an average of around 7 deaths per year. Under a no acclimatisation scenario, annual average heat-related mortality would rise to 24 deaths/year (95% CI: 8.4-38.4) in the near future and to 46 deaths/year (95% CI: 16.4-74.4) in the far future. Under a heat acclimatisation scenario, mortality would not increase significantly in the near or in the far future. Regarding wintertime cold-related mortality in the sample period 2009-2015, we observed increased mortality on days on which the minimum daily temperature fell below - 12 °C (the 7th percentile of the series), with an average of around 10 deaths a year. Keeping the threshold temperature constant, annual average cold-related mortality would decrease markedly in the near future, to 5 deaths/year (95% CI: 0.8-7.9) and even more in the far future, down to 0.44 deaths/year (95% C: 0.1-0.8). Assuming a "middle ground" between the acclimatisation and non-acclimatisation scenarios, the decrease in cold-related mortality will not compensate the increase in heat-related mortality. Thermal extremes, both heat and cold, constitute a serious public health threat in Vilnius, and in a changing climate the decrease in mortality attributable to cold will not compensate for the increase in mortality attributable to heat. Study results reinforce the notion that public health prevention against thermal extremes should be designed as a dynamic, adaptive process from the inception. Copyright © 2018 Elsevier Inc. All rights reserved.

Chilled in Translation: Adapting to Bacterial Climate Change.

PubMed

Gottesman, Susan

2018-04-19

Cold-shocked bacteria transiently shut down protein translation, but the mechanisms whereby they adaptively restore translation were incompletely understood. Zhang et al. (2018) demonstrate a global increase in mRNA structure after cold shock and that, as structured RNA decreases, translation returns, dependent upon ribonuclease RNase R and cold shock protein CspA and its homologs. Published by Elsevier Inc.

Interpopulational variation in the cold tolerance of a broadly distributed marine copepod

PubMed Central

Wallace, Gemma T.; Kim, Tiffany L.; Neufeld, Christopher J.

2014-01-01

Latitudinal trends in cold tolerance have been observed in many terrestrial ectotherms, but few studies have investigated interpopulational variation in the cold physiology of marine invertebrates. Here, the intertidal copepod Tigriopus californicus was used as a model system to study how local adaptation influences the cold tolerance of a broadly distributed marine crustacean. Among five populations spanning 18° in latitude, the following three metrics were used to compare cold tolerance: the temperature of chill-coma onset, the chill-coma recovery time and post-freezing recovery. In comparison to copepods from warmer southern latitudes, animals from northern populations exhibited lower chill-coma onset temperatures, shorter chill-coma recovery times and faster post-freezing recovery rates. Importantly, all three metrics showed a consistent latitudinal trend, suggesting that any single metric could be used equivalently in future studies investigating latitudinal variation in cold tolerance. Our results agree with previous studies showing that populations within a single species can display strong local adaptation to spatially varying climatic conditions. Thus, accounting for local adaptation in bioclimate models will be useful for understanding how broadly distributed species like T. californicus will respond to anthropogenic climate change. PMID:27293662

Interpopulational variation in the cold tolerance of a broadly distributed marine copepod.

PubMed

Wallace, Gemma T; Kim, Tiffany L; Neufeld, Christopher J

2014-01-01

Latitudinal trends in cold tolerance have been observed in many terrestrial ectotherms, but few studies have investigated interpopulational variation in the cold physiology of marine invertebrates. Here, the intertidal copepod Tigriopus californicus was used as a model system to study how local adaptation influences the cold tolerance of a broadly distributed marine crustacean. Among five populations spanning 18° in latitude, the following three metrics were used to compare cold tolerance: the temperature of chill-coma onset, the chill-coma recovery time and post-freezing recovery. In comparison to copepods from warmer southern latitudes, animals from northern populations exhibited lower chill-coma onset temperatures, shorter chill-coma recovery times and faster post-freezing recovery rates. Importantly, all three metrics showed a consistent latitudinal trend, suggesting that any single metric could be used equivalently in future studies investigating latitudinal variation in cold tolerance. Our results agree with previous studies showing that populations within a single species can display strong local adaptation to spatially varying climatic conditions. Thus, accounting for local adaptation in bioclimate models will be useful for understanding how broadly distributed species like T. californicus will respond to anthropogenic climate change.

An atypical case of successful resuscitation of an accidental profound hypothermia patient, occurring in a temperate climate.

PubMed

Coleman, E; Doddakula, K; Meeke, R; Marshall, C; Jahangir, S; Hinchion, J

2010-03-01

Cases of accidental profound hypothermia occur most frequently in cold, northern climates. We describe an atypical case, occurring in a temperate climate, where a hypothermic cardiac-arrested patient was successfully resuscitated using extracorporeal circulation (ECC).

Cold Temperatures Increase Cold Hardiness in the Next Generation Ophraella communa Beetles

PubMed Central

Zhou, Zhong-Shi; Rasmann, Sergio; Li, Min; Guo, Jian-Ying; Chen, Hong-Song; Wan, Fang-Hao

2013-01-01

The leaf beetle, Ophraella communa, has been introduced to control the spread of the common ragweed, Ambrosia artemisiifolia, in China. We hypothesized that the beetle, to be able to track host-range expansion into colder climates, can phenotypically adapt to cold temperatures across generations. Therefore, we questioned whether parental experience of colder temperatures increases cold tolerance of the progeny. Specifically, we studied the demography, including development, fecundity, and survival, as well as physiological traits, including supercooling point (SCP), water content, and glycerol content of O. communa progeny whose parents were maintained at different temperature regimes. Overall, the entire immature stage decreased survival of about 0.2%–4.2% when parents experienced cold temperatures compared to control individuals obtained from parents raised at room temperature. However, intrinsic capacity for increase (r), net reproductive rate (R 0) and finite rate of increase (λ) of progeny O. communa were maximum when parents experienced cold temperatures. Glycerol contents of both female and male in progeny was significantly higher when maternal and paternal adults were cold acclimated as compared to other treatments. This resulted in the supercooling point of the progeny adults being significantly lower compared to beetles emerging from parents that experienced room temperatures. These results suggest that cold hardiness of O. communa can be promoted by cold acclimation in previous generation, and it might counter-balance reduced survival in the next generation, especially when insects are tracking their host-plants into colder climates. PMID:24098666

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.

Remote Sensing of Supercooled Cloud Layers in Cold Climate Using Ground Based Integrated Sensors System and Comparison with Pilot Reports and model forecasts

NASA Astrophysics Data System (ADS)

Boudala, Faisal; Wu, Di; Gultepe, Ismail; Anderson, Martha; turcotte, marie-france

2017-04-01

In-flight aircraft icing is one of the major weather hazards to aviation . It occurs when an aircraft passes through a cloud layer containing supercooled drops (SD). The SD in contact with the airframe freezes on the surface which degrades the performance of the aircraft.. Prediction of in-flight icing requires accurate prediction of SD sizes, liquid water content (LWC), and temperature. The current numerical weather predicting (NWP) models are not capable of making accurate prediction of SD sizes and associated LWC. Aircraft icing environment is normally studied by flying research aircraft, which is quite expensive. Thus, developing a ground based remote sensing system for detection of supercooled liquid clouds and characterization of their impact on severity of aircraft icing one of the important tasks for improving the NWPs based predictions and validations. In this respect, Environment and Climate Change Canada (ECCC) in cooperation with the Department of National Defense (DND) installed a number of specialized ground based remote sensing platforms and present weather sensors at Cold Lake, Alberta that includes a multi-channel microwave radiometer (MWR), K-band Micro Rain radar (MRR), Ceilometer, Parsivel distrometer and Vaisala PWD22 present weather sensor. In this study, a number of pilot reports confirming icing events and freezing precipitation that occurred at Cold Lake during the 2014-2016 winter periods and associated observation data for the same period are examined. The icing events are also examined using aircraft icing intensity estimated using ice accumulation model which is based on a cylindrical shape approximation of airfoil and the Canadian High Resolution Regional Deterministic Prediction System (HRDPS) model predicted LWC, median volume diameter and temperature. The results related to vertical atmospheric profiling conditions, surface observations, and the Canadian High Resolution Regional Deterministic Prediction System (HRDPS) model predictions are given. Preliminary results suggest that remote sensing and present weather sensors based observations of cloud SD regions can be used to describe micro and macro physical characteristics of the icing conditions. The model based icing intensity prediction reasonably agreed with the PIREPs and MWR observations.

Cold Stress

MedlinePlus

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

Effect assessment of Future Climate Change on Water Resource and Snow Quality in cold snowy regions in Japan

NASA Astrophysics Data System (ADS)

Taniguchi, Y.; Nakatsugawa, M.; Kudo, K.

2017-12-01

It is predicted that the effects of global warming on everyday life will be clearly seen in cold, snowy regions such as Hokkaido. In relation to climate change, there is the concern that the warmer climate will affect not only water resources, but also local economies, in snowy areas, when air temperature increases and snowfall decreases become more marked in the future. Communities whose economies are greatly dependent on snow as a tourism resource, such as for winter sports and snow events, will lose large numbers of visitors because of the shortened winter season. This study was done as a basic study to provide basic ideas for planning adaptation strategies against climate change based on the local characteristics of a cold, snowy region. By taking dam catchment basins in Hokkaido as the subject areas and by using the climate change prediction data that correspond to IPCCAR5, the local-level influence of future climate change on snowfall and snow quality in relation to water resources and winter sports was quantitatively assessed. The water budget was examined for a dam catchment basin in Hokkaido under the present climate (September 1984 to August 2004) and under the future climate (September 2080 to August 2100) by using rainfall, snowfall and evapotranspiration estimated by the LoHAS heat and water balance analysis model.The examination found that, under the future climate, the net annual precipitation will decrease by up to 200 mm because of decreases in precipitation and in runoff height that will result from increased evapotranspiration. The predicted decrease in annual hydro potential of snowfall was considered to greatly affect the dam reservoir operation during the snowmelt season. The snow quality analysis by SNOWPACK revealed that the future snow would become granular earlier than it does at present. Most skiers' snow preferences, from best to worst, are light dry snow (i.e., fresh snow), lightly compacted snow, compacted snow and, finally, granular snow. If the late-season snow on the slope becomes granular earlier than it has in previous years, then the ski resort's snow conditions will deteriorate. Businesses that receive economic benefits from snow have developed in cold, snowy areas. This study demonstrates that the economic benefits of snow are expected to be greatly reduced by future climate change.

Metabolic cold adaptation in fishes occurs at the level of whole animal, mitochondria and enzyme

PubMed Central

White, Craig R.; Alton, Lesley A.; Frappell, Peter B.

2012-01-01

Metabolic cold adaptation (MCA), the hypothesis that species from cold climates have relatively higher metabolic rates than those from warm climates, was first proposed nearly 100 years ago and remains one of the most controversial hypotheses in physiological ecology. In the present study, we test the MCA hypothesis in fishes at the level of whole animal, mitochondria and enzyme. In support of the MCA hypothesis, we find that when normalized to a common temperature, species with ranges that extend to high latitude (cooler climates) have high aerobic enzyme (citrate synthase) activity, high rates of mitochondrial respiration and high standard metabolic rates. Metabolic compensation for the global temperature gradient is not complete however, so when measured at their habitat temperature species from high latitude have lower absolute rates of metabolism than species from low latitudes. Evolutionary adaptation and thermal plasticity are therefore insufficient to completely overcome the acute thermodynamic effects of temperature, at least in fishes. PMID:22158960

Inoculation with a psychrotrophic-thermophilic complex microbial agent accelerates onset and promotes maturity of dairy manure-rice straw composting under cold climate conditions.

PubMed

Gou, Changlong; Wang, Yuqiong; Zhang, Xiqing; Lou, Yujie; Gao, Yunhang

2017-11-01

The objective was to determine the effects of psychrotrophic-thermophilic complex microbial agent (PTCMA) comprised of a psychrotrophic bacterium consortium (PBC) and a thermophilic cellulolytic fungi consortium (TCFC), on composting in a cold climate. Mixtures of dairy manure and rice straw were inoculated with PTCMA, PBC, TCFC and sterile water (control) and composted at an initial ambient temperatures of -2 to 5°C. In compost piles inoculated with PBC or PTCMA, temperatures reached the thermophilic phase (>55°C) faster (8-11d) than piles inoculated with TCFC or control. Furthermore, compost inoculated with TCFC or PTCMA had greater decreases in total organic carbon and carbon-to-nitrogen ratios, as well as significant increases in total nitrogen, degradation of cellulose and lignin and germination index than PBC inoculation or Control compost. Consequently, inoculation with both (i.e. PTCMA) accelerated the onset and promoted maturity of composting under cold-climate conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Metabolic cold adaptation in fishes occurs at the level of whole animal, mitochondria and enzyme.

PubMed

White, Craig R; Alton, Lesley A; Frappell, Peter B

2012-05-07

Metabolic cold adaptation (MCA), the hypothesis that species from cold climates have relatively higher metabolic rates than those from warm climates, was first proposed nearly 100 years ago and remains one of the most controversial hypotheses in physiological ecology. In the present study, we test the MCA hypothesis in fishes at the level of whole animal, mitochondria and enzyme. In support of the MCA hypothesis, we find that when normalized to a common temperature, species with ranges that extend to high latitude (cooler climates) have high aerobic enzyme (citrate synthase) activity, high rates of mitochondrial respiration and high standard metabolic rates. Metabolic compensation for the global temperature gradient is not complete however, so when measured at their habitat temperature species from high latitude have lower absolute rates of metabolism than species from low latitudes. Evolutionary adaptation and thermal plasticity are therefore insufficient to completely overcome the acute thermodynamic effects of temperature, at least in fishes.

Should anthropogenic warming lead to more frequent cold air outbreaks over the northeastern U.S.?

NASA Astrophysics Data System (ADS)

Nicholas, R.

2014-12-01

For the northeastern United States, Winter 2013-14 was the coldest winter since the late 1970s and perhaps the coldest on record relative to prevailing climatic conditions. Frequent snowstorms and cold air outbreaks led to considerable press coverage and heated scholarly debate over the possible role of anthropogenic climate change in modulating wintertime variability in the northern hemisphere polar jet. While mechanisms have been proposed, to date, the observational record offers no definitive evidence for such a relationship, nor does it conclusively exclude one. To further explore this question, we employ a large, initial conditions ensemble of the Community Earth System Model forced with historical and RCP8.5 emissions. The ensemble effectively samples internal variability in the climate system and is used to assess the potential for forced changes in polar jet variability and the frequency of cold air outbreaks over the northeastern U.S. with projected increases in global mean temperature during the 21st century.

Parallel Evolution of Cold Tolerance within Drosophila melanogaster

PubMed Central

Braun, Dylan T.; Lack, Justin B.

2017-01-01

Drosophila melanogaster originated in tropical Africa before expanding into strikingly different temperate climates in Eurasia and beyond. Here, we find elevated cold tolerance in three distinct geographic regions: beyond the well-studied non-African case, we show that populations from the highlands of Ethiopia and South Africa have significantly increased cold tolerance as well. We observe greater cold tolerance in outbred versus inbred flies, but only in populations with higher inversion frequencies. Each cold-adapted population shows lower inversion frequencies than a closely-related warm-adapted population, suggesting that inversion frequencies may decrease with altitude in addition to latitude. Using the FST-based “Population Branch Excess” statistic (PBE), we found only limited evidence for parallel genetic differentiation at the scale of ∼4 kb windows, specifically between Ethiopian and South African cold-adapted populations. And yet, when we looked for single nucleotide polymorphisms (SNPs) with codirectional frequency change in two or three cold-adapted populations, strong genomic enrichments were observed from all comparisons. These findings could reflect an important role for selection on standing genetic variation leading to “soft sweeps”. One SNP showed sufficient codirectional frequency change in all cold-adapted populations to achieve experiment-wide significance: an intronic variant in the synaptic gene Prosap. Another codirectional outlier SNP, at senseless-2, had a strong association with our cold trait measurements, but in the opposite direction as predicted. More generally, proteins involved in neurotransmission were enriched as potential targets of parallel adaptation. The ability to study cold tolerance evolution in a parallel framework will enhance this classic study system for climate adaptation. PMID:27777283

Climate change and health in Israel: adaptation policies for extreme weather events.

PubMed

Green, Manfred S; Pri-Or, Noemie Groag; Capeluto, Guedi; Epstein, Yoram; Paz, Shlomit

2013-06-27

Climatic changes have increased the world-wide frequency of extreme weather events such as heat waves, cold spells, floods, storms and droughts. These extreme events potentially affect the health status of millions of people, increasing disease and death. Since mitigation of climate change is a long and complex process, emphasis has recently been placed on the measures required for adaptation. Although the principles underlying these measures are universal, preparedness plans and policies need to be tailored to local conditions. In this paper, we conducted a review of the literature on the possible health consequences of extreme weather events in Israel, where the conditions are characteristic of the Mediterranean region. Strong evidence indicates that the frequency and duration of several types of extreme weather events are increasing in the Mediterranean Basin, including Israel. We examined the public health policy implications for adaptation to climate change in the region, and proposed public health adaptation policy options. Preparedness for the public health impact of increased extreme weather events is still relatively limited and clear public health policies are urgently needed. These include improved early warning and monitoring systems, preparedness of the health system, educational programs and the living environment. Regional collaboration should be a priority.

Differential response of vegetation in Hulun Lake region at the northern margin of Asian summer monsoon to extreme cold events of the last deglaciation

NASA Astrophysics Data System (ADS)

Zhang, Shengrui; Xiao, Jule; Xu, Qinghai; Wen, Ruilin; Fan, Jiawei; Huang, Yun; Yamagata, Hideki

2018-06-01

The response of vegetation to extreme cold events during the last deglaciation is important for assessing the impact of possible extreme climatic events on terrestrial ecosystems under future global warming scenarios. Here, we present a detailed record of the development of regional vegetation in the northern margin of Asian summer monsoon during the last deglaciation (16,500-11,000 cal yr BP) based on a radiocarbon-dated high-resolution pollen record from Hulun Lake, northeast China. The results show that the regional vegetation changed from subalpine meadow-desert steppe to mixed coniferous and deciduous forest-typical steppe during the last deglaciation. However, its responses to the Heinrich event 1 (H1) and the Younger Dryas event (YD) were significantly different: during the H1 event, scattered sparse forest was present in the surrounding mountains, while within the lake catchment the vegetation cover was poor and was dominated by desert steppe. In contrast, during the YD event, deciduous forest developed and the proportion of coniferous forest increased in the mountains, the lake catchment was occupied by typical steppe. We suggest that changes in Northern Hemisphere summer insolation and land surface conditions (ice sheets and sea level) caused temperature and monsoonal precipitation variations that contributed to the contrasting vegetation response during the two cold events. We conclude that under future global warming scenarios, extreme climatic events may cause a deterioration of the ecological environment of the Hulun Lake region, resulting in increased coniferous forest and decreased total forest cover in the surrounding mountains, and a reduction in typical steppe in the lake catchment.

Global Association of Cold Spells and Adverse Health Effects: A Systematic Review and Meta-Analysis

PubMed Central

Ryti, Niilo R.I.; Guo, Yuming; Jaakkola, Jouni J.K.

2015-01-01

Background There is substantial evidence that mortality increases in low temperatures. Less is known about the role of prolonged cold periods denoted as cold spells. Objective We conducted the first systematic review and meta-analysis to summarize the evidence on the adverse health effects of cold spells in varying climates. Data sources and extraction Four databases (Ovid Medline, PubMed, Scopus, Web of Science) were searched for all years and languages available. “Cold spell” was defined as an event below a temperature threshold lasting for a minimum duration of 2 days. Of 1,527 identified articles, 26 satisfied our eligibility criteria for the systematic review, and 9 were eligible for meta-analyses. The articles were grouped by the three main study questions into Overall-effect Group, Added-effect Group, and Temperature-change-effect Group. Data synthesis Based on random-effects models in the meta-analyses, cold spells were associated with increased mortality from all or all nonaccidental causes (summary rate ratio = 1.10; 95% CI: 1.04, 1.17 based on 9 estimates from five studies), cardiovascular diseases (1.11; 95% CI: 1.03, 1.19; 12 estimates from eight studies), and respiratory diseases (1.21; 95% CI: 0.97, 1.51; 8 estimates from four studies). Estimated associations were stronger for people ≥ 65 years of age (1.06; 95% CI: 1.00, 1.12) than for people 0–64 years of age (1.01; 95% CI: 1.00, 1.03). Study-specific effect estimates from a limited number of studies suggested an increased morbidity related to cold spells, but it was not possible to quantitatively summarize the evidence. Conclusions Cold spells are associated with increased mortality rates in populations around the world. The body of evidence suggests that cold spells also have other adverse health effects. There was substantial heterogeneity among the studies, which should be taken into account in the interpretation of the results. Citation Ryti NR, Guo Y, Jaakkola JJ. 2016. Global association of cold spells and adverse health effects: a systematic review and meta-analysis. Environ Health Perspect 124:12–22; http://dx.doi.org/10.1289/ehp.1408104 PMID:25978526

Global Association of Cold Spells and Adverse Health Effects: A Systematic Review and Meta-Analysis.

PubMed

Ryti, Niilo R I; Guo, Yuming; Jaakkola, Jouni J K

2016-01-01

There is substantial evidence that mortality increases in low temperatures. Less is known about the role of prolonged cold periods denoted as cold spells. We conducted the first systematic review and meta-analysis to summarize the evidence on the adverse health effects of cold spells in varying climates. Four databases (Ovid Medline, PubMed, Scopus, Web of Science) were searched for all years and languages available. "Cold spell" was defined as an event below a temperature threshold lasting for a minimum duration of 2 days. Of 1,527 identified articles, 26 satisfied our eligibility criteria for the systematic review, and 9 were eligible for meta-analyses. The articles were grouped by the three main study questions into Overall-effect Group, Added-effect Group, and Temperature-change-effect Group. Based on random-effects models in the meta-analyses, cold spells were associated with increased mortality from all or all nonaccidental causes (summary rate ratio = 1.10; 95% CI: 1.04, 1.17 based on 9 estimates from five studies), cardiovascular diseases (1.11; 95% CI: 1.03, 1.19; 12 estimates from eight studies), and respiratory diseases (1.21; 95% CI: 0.97, 1.51; 8 estimates from four studies). Estimated associations were stronger for people ≥ 65 years of age (1.06; 95% CI: 1.00, 1.12) than for people 0-64 years of age (1.01; 95% CI: 1.00, 1.03). Study-specific effect estimates from a limited number of studies suggested an increased morbidity related to cold spells, but it was not possible to quantitatively summarize the evidence. Cold spells are associated with increased mortality rates in populations around the world. The body of evidence suggests that cold spells also have other adverse health effects. There was substantial heterogeneity among the studies, which should be taken into account in the interpretation of the results. Ryti NR, Guo Y, Jaakkola JJ. 2016. Global association of cold spells and adverse health effects: a systematic review and meta-analysis. Environ Health Perspect 124:12-22; http://dx.doi.org/10.1289/ehp.1408104.

Persistent Cold Air Outbreaks over North America Under Climate Warming

NASA Astrophysics Data System (ADS)

Gao, Y.; Leung, L. R.; Lu, J.

2014-12-01

This study evaluates the change of cold air outbreaks (CAO) over North America using Coupled Model Intercomparison Project Phase 5 (CMIP5) multi-model ensemble of global climate simulations as well as regional high resolution climate simulations. In future, while robust decrease of CAO duration dominates in most of the North America, the decrease over northwestern U.S. was found to have much smaller magnitude than the surrounding regions. We found statistically significant increase of the sea level pressure over gulf of Alaska, leading to the advection of cold air to northwestern U.S.. By shifting the probability distribution of present temperature towards future warmer conditions, we identified the changes in large scale circulation contribute to about 50% of the enhanced sea level pressure. Using the high resolution regional climate model results, we found that increases of existing snowpack could potentially trigger the increase of CAO in the near future over the southwestern U.S. and Rocky Mountain through surface albedo effects. By the end of this century, the top 5 most extreme historical CAO events may still occur and wind chill warning will continue to have societal impacts over North America in particular over northwestern United States.

Ear infection - acute

MedlinePlus

... more than 6 children) Changes in altitude or climate Cold climate Exposure to smoke Family history of ear infections ... Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine, Seattle, WA. Internal review and update ...

Temporal dynamics of direct N2O fluxes from agro-ecosystems in cold climates: importance of year-round measurements in multiple cropping systems

NASA Astrophysics Data System (ADS)

Wagner-Riddle, C.; Tenuta, M.

2014-12-01

Soil N2O fluxes (direct emissions) are highly variable in time and space due to soil, weather and management drivers. In cold climates, freeze/thaw cycles and short growing seasons can enhance soil N2O production contributing to the temporal variability of fluxes. Year-round measurements of N2O fluxes in multiple cropping systems are needed to decrease the uncertainty of annual emission estimates and to devise mitigation practices for emission reduction in cold climates. We have deployed a micrometeorological flux-gradient approach coupled to a tunable diode laser absorption spectroscopy system at two long-term sites in Canada: Elora, Ontario (2000-2014) and Glenlea, Manitoba (2006-2014). Quasi-simultaneous half-hourly flux measurements on four 4-ha fields within a level and aerodynamically homogeneous landscape were obtained allowing for comparison of crop type and/or management practices within and between years. Annual crops such as corn, soybeans, wheat, and barley received typical inorganic fertilizer and/or manure applications, and best management practices such as timing of application and reduced tillage were studied. Perennial grass-alfalfa hayfields were compared to annual crops during selected time periods. Here we synthesize the long-term datasets from these two sites, and quantify the overall contribution of non-growing season (mainly freeze/thaw cycles) and growing season (mainly nitrogen application) to annual emission totals. Uncertainties of regional estimates for cold-climates will be assessed using these long-term datasets.

Effects of Temperature, Salinity and Fish in Structuring the Macroinvertebrate Community in Shallow Lakes: Implications for Effects of Climate Change

PubMed Central

Brucet, Sandra; Boix, Dani; Nathansen, Louise W.; Quintana, Xavier D.; Jensen, Elisabeth; Balayla, David; Meerhoff, Mariana; Jeppesen, Erik

2012-01-01

Climate warming may lead to changes in the trophic structure and diversity of shallow lakes as a combined effect of increased temperature and salinity and likely increased strength of trophic interactions. We investigated the potential effects of temperature, salinity and fish on the plant-associated macroinvertebrate community by introducing artificial plants in eight comparable shallow brackish lakes located in two climatic regions of contrasting temperature: cold-temperate and Mediterranean. In both regions, lakes covered a salinity gradient from freshwater to oligohaline waters. We undertook day and night-time sampling of macroinvertebrates associated with the artificial plants and fish and free-swimming macroinvertebrate predators within artificial plants and in pelagic areas. Our results showed marked differences in the trophic structure between cold and warm shallow lakes. Plant-associated macroinvertebrates and free-swimming macroinvertebrate predators were more abundant and the communities richer in species in the cold compared to the warm climate, most probably as a result of differences in fish predation pressure. Submerged plants in warm brackish lakes did not seem to counteract the effect of fish predation on macroinvertebrates to the same extent as in temperate freshwater lakes, since small fish were abundant and tended to aggregate within the macrophytes. The richness and abundance of most plant-associated macroinvertebrate taxa decreased with salinity. Despite the lower densities of plant-associated macroinvertebrates in the Mediterranean lakes, periphyton biomass was lower than in cold temperate systems, a fact that was mainly attributed to grazing and disturbance by fish. Our results suggest that, if the current process of warming entails higher chances of shallow lakes becoming warmer and more saline, climatic change may result in a decrease in macroinvertebrate species richness and abundance in shallow lakes. PMID:22393354

The Effects of Extreme Temperature Events on Human Mortality in Europe: Winners and Losers

NASA Astrophysics Data System (ADS)

Merte, S.

2016-12-01

Climate change is a sizable threat to public health. Besides the shift in mean temperatures, there is also a change in the frequency of extreme temperature events. While cold spells become less frequent, heat waves become more common. As either of these can cause human death, the net-effect of climate change in terms of human excess mortality is currently unclear and and will vary depending on local conditions. The ability to estimate this net-effect is key when it comes to designing effective climate change adaptation policies as some areas will be affected earlier and/or stronger than others. This work provides the first large-scale estimate of this net-effect for Europe. Utilizing a novel methodology based on singular systems analysis, climate extreme-driven excess mortality is estimated using national-level health data. The first notable finding of this work is the confirmation that extreme temperature events already pose a major environmental risk: tens of thousands of people die every year in the examined European countries as a result of heat waves and cold spells. The second important result is that it demonstrates the need for climate change mitigation: Assuming moderate climate change, some countries in Northern and Western Europe will benefit from the shift in extreme temperature events — they will experience a net-reduction in excess mortality as a result of a drastically reduced frequency of cold spells. In contrast, assuming severe climate change, there will be a significant increase in excess mortality, in particular across countries in Southern Europe. This means that -if climate adaptation fails- there will be no winners, just losers.

Ecosystem engineering creates a direct nutritional link between 600-m deep cold-water coral mounds and surface productivity.

PubMed

Soetaert, Karline; Mohn, Christian; Rengstorf, Anna; Grehan, Anthony; van Oevelen, Dick

2016-10-11

Cold-water corals (CWCs) form large mounds on the seafloor that are hotspots of biodiversity in the deep sea, but it remains enigmatic how CWCs can thrive in this food-limited environment. Here, we infer from model simulations that the interaction between tidal currents and CWC-formed mounds induces downwelling events of surface water that brings organic matter to 600-m deep CWCs. This positive feedback between CWC growth on carbonate mounds and enhanced food supply is essential for their sustenance in the deep sea and represents an example of ecosystem engineering of unparalleled magnitude. This 'topographically-enhanced carbon pump' leaks organic matter that settles at greater depths. The ubiquitous presence of biogenic and geological topographies along ocean margins suggests that carbon sequestration through this pump is of global importance. These results indicate that enhanced stratification and lower surface productivity, both expected consequences of climate change, may negatively impact the energy balance of CWCs.

Ecosystem engineering creates a direct nutritional link between 600-m deep cold-water coral mounds and surface productivity

NASA Astrophysics Data System (ADS)

Soetaert, Karline; Mohn, Christian; Rengstorf, Anna; Grehan, Anthony; van Oevelen, Dick

2016-10-01

Cold-water corals (CWCs) form large mounds on the seafloor that are hotspots of biodiversity in the deep sea, but it remains enigmatic how CWCs can thrive in this food-limited environment. Here, we infer from model simulations that the interaction between tidal currents and CWC-formed mounds induces downwelling events of surface water that brings organic matter to 600-m deep CWCs. This positive feedback between CWC growth on carbonate mounds and enhanced food supply is essential for their sustenance in the deep sea and represents an example of ecosystem engineering of unparalleled magnitude. This ’topographically-enhanced carbon pump’ leaks organic matter that settles at greater depths. The ubiquitous presence of biogenic and geological topographies along ocean margins suggests that carbon sequestration through this pump is of global importance. These results indicate that enhanced stratification and lower surface productivity, both expected consequences of climate change, may negatively impact the energy balance of CWCs.

21 Layer troposphere-stratosphere climate model

NASA Technical Reports Server (NTRS)

Rind, D.; Suozzo, R.; Lacis, A.; Russell, G.; Hansen, J.

1984-01-01

The global climate model is extended through the stratosphere by increasing the vertical resolution and raising the rigid model top to the 0.01 mb (75 km) level. The inclusion of a realistic stratosphere is necessary for the investigation of the climate effects of stratospheric perturbations, such as changes of ozone, aerosols or solar ultraviolet irradiance, as well as for studying the effect on the stratosphere of tropospheric climate changes. The observed temperature and wind patterns throughout the troposphere and stratosphere are simulated. In addition to the excess planetary wave amplitude in the upper stratosphere, other model deficiences include the Northern Hemisphere lower stratospheric temperatures being 5 to 10 C too cold in winter at high latitudes and the temperature at 50 to 60 km altitude near the equator are too cold. Methods of correcting these deficiencies are discussed.

An Analysis of Historical Records of Solar Variability, Volcanic Eruptions, and Climate Change in the Last Millennium

NASA Astrophysics Data System (ADS)

Pang, K. D.

2003-12-01

Studying past climate changes can help us better understand present natural variations and predict future trends. However, various reconstructions of the climate of the last 1000 years have given only broad similarities [Briffa, JGR 106, 2929, 2001]. The variances are partly due to uncertainties in the past radiative and aerosol forcing, and gaps in regional coverage. Another outstanding question is whether we are in a time similar to the Medieval Warm Period. From the frequencies of sunspot and aurora sightings, abundance of carbon-14 in the rings of long-lived trees, and beryllium-10 in the annual layers of polar ice cores, we have reconstructed the recent history of a variable Sun. In the past 1800 years the Sun has gone through nine cycles of changes in brightness. While these long-term changes account for less than 1% of the total irradiance, there is clear evidence that they affect the climate [Pang and Yau, Eos, 83, No. 43, 481, 2002]. We have analyzed Chinese historical weather records to fill the data void in this region. Reports of unseasonable cold are classified by the degree of severity: (1) Late (April-June) or early (July-Sept) killing frosts; (2) Bitter cold/heavy snowfall; and (3) heavy sustained snowfall, bitter cold with frozen wells, lakes, rivers, and icebound seas. The latter cases were often widespread and multi-year. All categories occurred most frequently during the coldest part of the Little Ice Age, with the coldest episodes in 1652-54, 1656, 1664, 1670-72, 1676-77, 1683, 1688-91, 1716 and 1718-19. They thus coincide with Maunder Minimum (1645-1715), when very few sunspots were seen-about one in ten years from China or Europe-indicative of a weakened Sun. There was only one Category 3 episode between the Maunder and Dalton Minima-in 1761, and two in the Dalton Minimum (1795-1825)-in 1796 and 1814-7. Analysis of proxy data has shown that the 1810's were among the coldest years in Europe [Briffa and Jones, in ``The Year Without a Summer,'' C.R. Harrignton, ed., 1992]. Large eruptions, of an unknown volcano in 1809 [Dai, JGR 96, 17361, 1991], at Mayon in 1814, and at Tambora in 1815, with the reduced solar luminosity seem to have been responsible. The Sun has slowly brightened since the Dalton Minimum. However, the climate of China remained cold through the 19th century, consistent with world climate trend [Bradley and Jones, Holocene 3, 367, 1993], possibly due to increased volcanic aerosol loading of the atmosphere [Sato, JGR 98, 22987, 1993]. In the 200 years prior to the Maunder Minimum, there was at least one other major planetwide volcanically forced cold episode-in 1453-54. The climate of China appears to have been warm during the Late 14th-Century Solar Maximum (1350-1410). We have found only one report of early killing frost-in May, 1993. It then turned cold during the Sporer Minimum (140-1590) [Pang and Yau, op. cit.]. Category 3 cold episodes occurred in 1453-54, 1513, 1569, and 1577-78. Lesser ones were also more common. The coldest was in 1453-54, due to a Tamboran class eruption that broke a big island in New Hebrides Arc in two, separated by a 12X6X1 km submarine caldera Kuwae. The volcanic chill was felt worldwide, with extensive reporting in China [Pang, Eos 74, No. 43, 196, 1993]. Reduced solar luminosity may have also contributed to the cold climate of that decade, as was the case in the 1810's. We conclude that the climate of China in the past 650 years generally follows world trend. The major forcing seems to have been changing solar luminosity, perturbed by frequent volcanic eruptions.

Human Physiological Responses to Acute and Chronic Cold Exposure

NASA Technical Reports Server (NTRS)

Stocks, Jodie M.; Taylor, Nigel A. S.; Tipton, Michael J.; Greenleaf, John E.

2001-01-01

When inadequately protected humans are exposed to acute cold, excessive body heat is lost to the environment and unless heat production is increased and heat loss attenuated, body temperature will decrease. The primary physiological responses to counter the reduction in body temperature include marked cutaneous vasoconstriction and increased metabolism. These responses, and the hazards associated with such exposure, are mediated by a number of factors which contribute to heat production and loss. These include the severity and duration of the cold stimulus; exercise intensity; the magnitude of the metabolic response; and individual characteristics such as body composition, age, and gender. Chronic exposure to a cold environment, both natural and artificial, results in physiological alterations leading to adaptation. Three quite different, but not necessarily exclusive, patterns of human cold adaptation have been reported: metabolic, hypothermic, and insulative. Cold adaptation has also been associated with an habituation response, in which there is a desensitization, or damping, of the normal response to a cold stress. This review provides a comprehensive analysis of the human physiological and pathological responses to cold exposure. Particular attention is directed to the factors contributing to heat production and heat loss during acute cold stress, and the ability of humans to adapt to cold environments.

Climate-Induced Boreal Forest Change: Predictions versus Current Observations

NASA Technical Reports Server (NTRS)

Soja, Amber J.; Tchebakova, Nadezda M.; French, Nancy H. F.; Flannigan, Michael D.; Shugart, Herman H.; Stocks, Brian J.; Sukhinin, Anatoly I.; Parfenova, E. I.; Chapin, F. Stuart, III; Stackhouse, Paul W., Jr.

2007-01-01

For about three decades, there have been many predictions of the potential ecological response in boreal regions to the currently warmer conditions. In essence, a widespread, naturally occurring experiment has been conducted over time. In this paper, we describe previously modeled predictions of ecological change in boreal Alaska, Canada and Russia, and then we investigate potential evidence of current climate-induced change. For instance, ecological models have suggested that warming will induce the northern and upslope migration of the treeline and an alteration in the current mosaic structure of boreal forests. We present evidence of the migration of keystone ecosystems in the upland and lowland treeline of mountainous regions across southern Siberia. Ecological models have also predicted a moisture-stress-related dieback in white spruce trees in Alaska, and current investigations show that as temperatures increase, white spruce tree growth is declining. Additionally, it was suggested that increases in infestation and wildfire disturbance would be catalysts that precipitate the alteration of the current mosaic forest composition. In Siberia, five of the last seven years have resulted in extreme fire seasons, and extreme fire years have also been more frequent in both Alaska and Canada. In addition, Alaska has experienced extreme and geographically expansive multi-year outbreaks of the spruce beetle, which had been previously limited by the cold, moist environment. We suggest that there is substantial evidence throughout the circumboreal region to conclude that the biosphere within the boreal terrestrial environment has already responded to the transient effects of climate change. Additionally, temperature increases and warming-induced change are progressing faster than had been predicted in some regions, suggesting a potential non-linear rapid response to changes in climate, as opposed to the predicted slow linear response to climate change.

Evaluation of human thermal comfort ranges in urban climate of winter cities on the example of Erzurum city.

PubMed

Toy, Süleyman; Kántor, Noémi

2017-01-01

Human thermal comfort conditions can be evaluated using various indices based on simple empirical approaches or more complex and reliable human-biometeorological approaches. The latter is based on the energy balance model of the human body, and their calculation is supplemented with computer software. Facilitating the interpretation of results, the generally applied indices express the effects of thermal environment in the well-known temperature unit, just like in the case of the widely used index, the physiologically equivalent temperature (PET). Several studies adopting PET index for characterizing thermal components of climate preferred to organize the resulted PET values into thermal sensation categories in order to demonstrate the spatial and/or temporal characteristics of human thermal comfort conditions. The most general applied PET ranges were derived by Central European researchers, and they are valid for assumed values of internal heat production of light activity and thermal resistance of clothing representing a light business suit. Based on the example of Erzurum city, the present work demonstrates that in a city with harsh winter, the original PET ranges show almost purely discomfort and they seem to be less applicable regarding cold climate conditions. Taking into account 34-year climate data of Erzurum, the annual distribution of PET is presented together with the impact of application of different PET categorization systems, including 8°- and 7°-wide PET intervals. The demonstrated prior analyses lack any questionnaire filed surveys in Erzurum. Thus, as a next step, detailed field investigations would be required with the aim of definition of new PET categorization systems which are relevant for local residents who are adapted to this climatic background, and for tourists who may perform various kinds of winter activities in Erzurum and therefore may perceive the thermal environment more comfortable.

Pain modulation during drives through cold and hot virtual environments.

PubMed

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

2007-08-01

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

Surveillance of infectious diseases in the Arctic.

PubMed

Bruce, M; Zulz, T; Koch, A

2016-08-01

This study reviews how social and environmental issues affect health in Arctic populations and describes infectious disease surveillance in Arctic Nations with a special focus on the activities of the International Circumpolar Surveillance (ICS) project. We reviewed the literature over the past 2 decades looking at Arctic living conditions and their effects on health and Arctic surveillance for infectious diseases. In regards to other regions worldwide, the Arctic climate and environment are extreme. Arctic and sub-Arctic populations live in markedly different social and physical environments compared to those of their more southern dwelling counterparts. A cold northern climate means people spending more time indoors, amplifying the effects of household crowding, smoking and inadequate ventilation on the person-to-person spread of infectious diseases. The spread of zoonotic infections north as the climate warms, emergence of antibiotic resistance among bacterial pathogens, the re-emergence of tuberculosis, the entrance of HIV into Arctic communities, the specter of pandemic influenza or the sudden emergence and introduction of new viral pathogens pose new challenges to residents, governments and public health authorities of all Arctic countries. ICS is a network of hospitals, public health agencies, and reference laboratories throughout the Arctic working together for the purposes of collecting, comparing and sharing of uniform laboratory and epidemiological data on infectious diseases of concern and assisting in the formulation of prevention and control strategies (Fig. 1). In addition, circumpolar infectious disease research workgroups and sentinel surveillance systems for bacterial and viral pathogens exist. The ICS system is a successful example of collaborative surveillance and research in an extreme environment. Published by Elsevier Ltd.

Plants in alpine environments

USGS Publications Warehouse

Germino, Matthew J.

2014-01-01

Alpine and subalpine plant species are of special interest in ecology and ecophysiology because they represent life at the climate limit and changes in their relative abundances can be a bellwether for climate-change impacts. Perennial life forms dominate alpine plant communities, and their form and function reflect various avoidance, tolerance, or resistance strategies to interactions of cold temperature, radiation, wind, and desiccation stresses that prevail in the short growing seasons common (but not ubiquitous) in alpine areas. Plant microclimate is typically uncoupled from the harsh climate of the alpine, often leading to substantially warmer plant temperatures than air temperatures recorded by weather stations. Low atmospheric pressure is the most pervasive, fundamental, and unifying factor for alpine environments, but the resulting decrease in partial pressure of CO2 does not significantly limit carbon gain by alpine plants. Factors such as tree islands and topographic features create strong heterogeneous mosaics of microclimate and snow cover that are reflected in plant community composition. Factors affecting tree establishment and growth and formation of treeline are key to understanding alpine ecology. Carbohydrate and other carbon storage, rapid development in a short growing season, and physiological function at low temperature are prevailing attributes of alpine plants. A major contemporary research theme asks whether chilling at alpine-treeline affects the ability of trees to assimilate the growth resources and particularly carbon needed for growth or whether the growth itself is limited by the alpine environment. Alpine areas tend to be among the best conserved, globally, yet they are increasingly showing response to a range of anthropogenic impacts, such as atmospheric deposition.

On the nature of man and disaster.

PubMed

Darwin, Mike

2006-02-01

Unique among animals, humans survive not by superb physical adaptation to our environment, but rather by intelligent, large-scale adaptation of the environment to our needs. We build houses with climate control systems that mimic the environment of sub-Saharan Africa. We safely live in environments where the temperature never rises above freezing and where the level of the sea is higher than the land we farm and build vast cities upon. We live in tropical rainforests teeming with hostile organisms, and atop arid, life-poor mountains and plains, at elevations in excess of 5000 m. As this editorial is written, a few of us live in space, circling the earth in an environment of hard vacuum, searing heat, and cryogenic cold. The sole endowment for our survival that evolution has bestowed upon us is reason and technologic civilization, which is its product. All human habitations, and all life on earth for that matter, are under continuous threat of some kind. Violent weather, earthquakes, volcanic eruptions, and even meteorite impacts represent threats of varying degrees of risk.

On the nature of man and disaster

PubMed Central

Darwin, Mike

2006-01-01

Unique among animals, humans survive not by superb physical adaptation to our environment, but rather by intelligent, large-scale adaptation of the environment to our needs. We build houses with climate control systems that mimic the environment of sub-Saharan Africa. We safely live in environments where the temperature never rises above freezing and where the level of the sea is higher than the land we farm and build vast cities upon. We live in tropical rainforests teeming with hostile organisms, and atop arid, life-poor mountains and plains, at elevations in excess of 5000 m. As this editorial is written, a few of us live in space, circling the earth in an environment of hard vacuum, searing heat, and cryogenic cold. The sole endowment for our survival that evolution has bestowed upon us is reason and technologic civilization, which is its product. All human habitations, and all life on earth for that matter, are under continuous threat of some kind. Violent weather, earthquakes, volcanic eruptions, and even meteorite impacts represent threats of varying degrees of risk. PMID:16934127

[Temporal and spatial variations of extreme climatic events in Songnen Grassland, Northeast China during 1960-2014].

PubMed

Ma, Qi Yun; Zhang, Ji Quan; Lai, Quan; Zhang, Feng; Dong, Zhen Hua; A, Lu Si

2017-06-18

Fourteen extreme climatic indices related with main regional meteorological disasters and vegetation growth were calculated based on daily data from 13 meteorological stations during 1960-2014 in Songnen Grassland, Northeast China. Then, the variation trend and the spatial and temporal patterns of climatic extreme events were analyzed by using regression analysis, break trend analy-sis, Mann-Kendall test, Sen's slope estimator and moving t-test method. The results indicated that summer days (SU25), warm days (TX90P), warm nights (TN90P) and warm spell duration (WSDI) representing extremely high temperatures showed significant increasing trends (P<0.05). Meanwhile, frost days (FD0), cold days (TX10P), cold nights (TN10P) and cold spell duration indicator (CSDI) representing extremely low temperatures showed obviously decreasing trends. The magnitudes of changes in cold indices (FD0, TX10P, TN10P and CSDI) were clearly greater than those of warm indices (SU25, TX90P, TN90P and WSDI), and that changes in night indices were larger than those of day indices. Regional climate warming trend was obvious from 1970 to 2009, and the most occurrences of the abrupt changes in these indices were identified in this period. The extreme precipitation indices did not show obvious trend, in general, SDII and CDD experienced a slightly decreasing trend while RX5D, R95P, PRCPTOT and CWD witnessed a mildly increasing trend. It may be concluded that regional climate changed towards warming and slightly wetting in Songnen Grassland. The most sensitive region for extreme temperature was distributed in the south and north region. Additionally, the extreme temperature indices showed clearly spatial difference between the south and the north. As for the spatial variations of extreme precipitation indices, the climate could be characterized by becoming wetter in northern region, and getting drier in southern region, especially in southwestern region with a high drought risk.

A case study of the microphysical and dynamical processes of fog and in-flight icing environments at Cold Lake Alberta, Canada

NASA Astrophysics Data System (ADS)

Wu, Di; Boudala, Faisal; Gultepe, Ismail; Isaac, George A.

2017-04-01

Pilot reports (PIREPs) of in-flight icing have been frequently been issued at Cold Lake airport (CYOD), Alberta, typically during descent on approach or climb after takeoff in the fall and winter seasons. Climatological data also indicate that this location is affected by various fog conditions. In order to better understand these conditions, Environment and Climate Change Canada (ECCC), in cooperation with the Department of National Defense (DND), installed a number of specialized instruments at Cold Lake. The ground based instruments include a Vaisala PWD22 present weather sensor, a multi-channel microwave profiling radiometer (MWRP) and a Jenoptik CHM15k ceilometer. A case study is presented of an icing event and foggy conditions that occurred very close to ground level and temperature changed from -1 C up to 2 C on 24 October, 2016. The microphysical and thermo-dynamical conditions within the boundary layer and aloft that led to these conditions were examined by integrating the ground based measurements with the Geostationary Operational Environmental Satellite (GOES) and the Canadian 2.5 km resolution NWP (HRDPS - High Resolution Deterministic Prediction System) model data. Preliminary results indicate that the ground based in-situ measurements were in agreement with the aviation weather observations (METAR). Both the HRDPS model and MWRP detected supercooled liquid water well during the icing event and its thermodynamic structure that remains to be investigated further. Furthermore, the icing potential and low clouds formation using the GOES Imager data will be compared with HRDPS simulations and verified by PIREPs.

Field Investigation of an Air-Source Cold Climate Heat Pump

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shen, Bo; Abdelaziz, Omar; Rice, C Keith

In the U.S., there are approximately 2.6 million dwellings that use electricity for heating in cold and very cold regions with an annual energy consumption of 0.16 quads (0.17 EJ). A high performance cold climate heat pump (CCHP) would result in significant savings over current technologies (greater than 60% compared to electric resistance heating). We developed an air-source cold climate heat pump, which uses tandem compressors, with a single compressor rated for the building design cooling load, and running two compressors to provide, at -13 F (-25 C), 75% of rated heating capacity. The tandem compressors were optimized for heatingmore » operation and are able to tolerate discharge temperatures up to 280 F (138 C). A field investigation was conducted in the winter of 2015, in an occupied home in Ohio, USA. During the heating season, the seasonal COP was measured at 3.16, and the heat pump was able to operate down to -13 F (-25 C) and eliminate resistance heat use. The heat pump maintained an acceptable comfort level throughout the heating season. In comparison to a previous single-speed heat pump in the home, the CCHP demonstrated more than 40% energy savings in the peak heating load month. This paper illustrates the measured field performance, including compressor run time, frost/defrosting operations, distributions of building heating load and capacity delivery, comfort level, field measured COPs, etc.« less

Geographic trend of bud hardiness response in Vitis riparia

USDA-ARS?s Scientific Manuscript database

A major goal of grapevine breeding efforts for production outside of Mediterranean climates is the production of varieties that have cold tolerance phenotypes. Typically, grapevine breeders use midwinter bud hardiness measures as the descriptive phenotype for cold tolerance. Historical practices of...

Project COLD.

ERIC Educational Resources Information Center

Kazanjian, Wendy C.

1982-01-01

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

Applicability of Satellite Freeze Forecasting and Cold Climate Mapping to the Other Parts of the United States

NASA Technical Reports Server (NTRS)

1981-01-01

Tasks performed to determine the value of using GOES satellite thermal imagery to enhance fruit crop production in Michigan are described. An overview is presented of the system developed for image processing and thermal image and surface environmental data bases prepared to assess the physical models developed in Florida. These data bases were used to identify correlations between satellite apparent temperatures patterns and Earth surface factors. Significant freeze events in 1981 and the physical models used to provide a perspective on how Florida models can be applied in the context of the Michigan environment are discussed.

Microbial ecology of extreme environments: Antarctic yeasts and growth in substrate-limited habitats

NASA Technical Reports Server (NTRS)

Vishniac, H. S.

1985-01-01

The high, dry valleys of the Ross Desert of Antarctic, characterized by extremely low temperatures, aridity and a depauperate biota, are used as an analog of the postulated extreme climates of other planetary bodies of the Solar System to test the hypothesis that if life could be supported by Ross, it might be possible where similar conditions prevail. The previously considered sterility of the Ross Desert soil ecosystem has yielded up an indigenous yeast, Cryptoccus vishniacci, which is able to resist the extremes of cold, wet and dry freezing, and long arid periods, while making minimal nutritional demands on the soil.

Hand-arm vibration exposure monitoring with wearable sensor module.

PubMed

Austad, Hanne O; Røed, Morten H; Liverud, Anders E; Dalgard, Steffen; Seeberg, Trine M

2013-01-01

Vibration exposure is a serious risk within work physiology for several work groups. Combined with cold artic climate, the risk for permanent harm is even higher. Equipment that can monitor the vibration exposure and warn the user when at risk will provide a safer work environment for these work groups. This study evaluates whether data from a wearable wireless multi-parameter sensor module can be used to estimate vibration exposure and exposure time. This work has been focused on the characterization of the response from the accelerometer in the sensor module and the optimal location of the module in the hand-arm configuration.

Ongoing climatic extreme dynamics in Siberia

NASA Astrophysics Data System (ADS)

Gordov, E. P.; Shulgina, T. M.; Okladnikov, I. G.; Titov, A. G.

2013-12-01

Ongoing global climate changes accompanied by the restructuring of global processes in the atmosphere and biosphere are strongly pronounced in the Northern Eurasia regions, especially in Siberia. Recent investigations indicate not only large changes in averaged climatic characteristics (Kabanov and Lykosov, 2006, IPCC, 2007; Groisman and Gutman, 2012), but more frequent occurrence and stronger impacts of climatic extremes are reported as well (Bulygina et al., 2007; IPCC, 2012: Climate Extremes, 2012; Oldenborh et al., 2013). This paper provides the results of daily temperature and precipitation extreme dynamics in Siberia for the last three decades (1979 - 2012). Their seasonal dynamics is assessed using 10th and 90th percentile-based threshold indices that characterize frequency, intensity and duration of climatic extremes. To obtain the geographical pattern of these variations with high spatial resolution, the sub-daily temperature data from ECMWF ERA-Interim reanalysis and daily precipitation amounts from APHRODITE JMA dataset were used. All extreme indices and linear trend coefficients have been calculated using web-GIS information-computational platform Climate (http://climate.scert.ru/) developed to support collaborative multidisciplinary investigations of regional climatic changes and their impacts (Gordov et al., 2012). Obtained results show that seasonal dynamics of daily temperature extremes is asymmetric for tails of cold and warm temperature extreme distributions. Namely, the intensity of warming during cold nights is higher than during warm nights, especially at high latitudes of Siberia. The similar dynamics is observed for cold and warm day-time temperatures. Slight summer cooling was observed in the central part of Siberia. It is associated with decrease in warm temperature extremes. In the southern Siberia in winter, we also observe some cooling mostly due to strengthening of the cold temperature extremes. Changes in daily precipitation extremes are spatially inhomogeneous. The largest increase in frequency and intensity of heavy precipitation is observed in the north of East Siberia. Negative trends related to precipitation amount decrease are found in the central West Siberia and in the south of East Siberia. The authors acknowledge partial financial support for this research from the Russian Foundation for Basic Research projects (11-05-01190 and 13-05-12034), SB RAS Integration project 131 and project VIII.80.2.1., the Ministry of Education and Science of the Russian Federation contract 8345 and grant of the President of Russian Federation (decree 181).

The impact of acclimatization on thermophysiological strain for contrasting regional climates

NASA Astrophysics Data System (ADS)

de Freitas, C. R.; Grigorieva, E. A.

2014-12-01

During acclimatization to heat and cold, the body experiences additional thermally induced physiological strain. The first signs show up in the respiratory organs because respiration is a continuous heat exchange process in which the body is in closest contact with the ambient air. There are no behavioral or other adjustments to prevent the ambient air from entering into the body's core area through the respiratory tract. The Acclimatization Thermal Strain Index (ATSI) describes the acclimatization thermal loading (ATL) on respiratory organs until full adaptation is achieved. The aim here is to further assess the ATSI scheme using a range of actual but contrasting bioclimatic conditions. To simulate ATL, scenarios of the consequences of acclimatization due to movement to or from five contrasting climates are used. The results show that adjusting to cold comes with greater physiological strain than adjusting to heat, the biggest impact occurring for a change of location from hot-humid to cold-dry climatic conditions. The approach can be used to assess risks due to increases in short-term thermal variability in weather conditions such as encountered during heat waves and cold snaps. The information could also be useful for assessing the need for public health services and measures that might be used to help mitigate impacts.

The impact of acclimatization on thermophysiological strain for contrasting regional climates.

PubMed

de Freitas, C R; Grigorieva, E A

2014-12-01

During acclimatization to heat and cold, the body experiences additional thermally induced physiological strain. The first signs show up in the respiratory organs because respiration is a continuous heat exchange process in which the body is in closest contact with the ambient air. There are no behavioral or other adjustments to prevent the ambient air from entering into the body's core area through the respiratory tract. The Acclimatization Thermal Strain Index (ATSI) describes the acclimatization thermal loading (ATL) on respiratory organs until full adaptation is achieved. The aim here is to further assess the ATSI scheme using a range of actual but contrasting bioclimatic conditions. To simulate ATL, scenarios of the consequences of acclimatization due to movement to or from five contrasting climates are used. The results show that adjusting to cold comes with greater physiological strain than adjusting to heat, the biggest impact occurring for a change of location from hot-humid to cold-dry climatic conditions. The approach can be used to assess risks due to increases in short-term thermal variability in weather conditions such as encountered during heat waves and cold snaps. The information could also be useful for assessing the need for public health services and measures that might be used to help mitigate impacts.

3D climate-carbon modelling of the early Earth

NASA Astrophysics Data System (ADS)

Charnay, B.; Le Hir, G.; Fluteau, F.; Forget, F.; Catling, D.

2017-09-01

We revisit the climate and carbon cycle of the early Earth at 3.8 Ga using a 3D climate-carbon model. Our resultsfavor cold or temperate climates with global mean temperatures between around 8°C (281 K) and 30°C (303 K) and with 0.1-0.36 bar of CO2 for the late Hadean and early Archean.

The role of climate change in interpreting historical variability

Treesearch

Constance I. Millar; Wallace B. Woolfenden

1999-01-01

Significant climate anomalies have characterized the last 1000 yr in the Sierra Nevada, California, USA. Two warm, dry periods of 150- and 200-yr duration occurred during AD 900-1350, which were followed by anomalously cold climates, known as the Little Ice Age, that lasted from AD 1400 to 1900. Climate in the last century has been significantly warmer. Regional biotic...

Effects of differential habitat warming on complex communities.

PubMed

Tunney, Tyler D; McCann, Kevin S; Lester, Nigel P; Shuter, Brian J

2014-06-03

Food webs unfold across a mosaic of micro and macro habitats, with each habitat coupled by mobile consumers that behave in response to local environmental conditions. Despite this fundamental characteristic of nature, research on how climate change will affect whole ecosystems has overlooked (i) that climate warming will generally affect habitats differently and (ii) that mobile consumers may respond to this differential change in a manner that may fundamentally alter the energy pathways that sustain ecosystems. This reasoning suggests a powerful, but largely unexplored, avenue for studying the impacts of climate change on ecosystem functioning. Here, we use lake ecosystems to show that predictable behavioral adjustments to local temperature differentials govern a fundamental structural shift across 54 food webs. Data show that the trophic pathways from basal resources to a cold-adapted predator shift toward greater reliance on a cold-water refuge habitat, and food chain length increases, as air temperatures rise. Notably, cold-adapted predator behavior may substantially drive this decoupling effect across the climatic range in our study independent of warmer-adapted species responses (for example, changes in near-shore species abundance and predator absence). Such modifications reflect a flexible food web architecture that requires more attention from climate change research. The trophic pathway restructuring documented here is expected to alter biomass accumulation, through the regulation of energy fluxes to predators, and thus potentially threatens ecosystem sustainability in times of rapid environmental change.

Standard seasons

NASA Astrophysics Data System (ADS)

Tuller, Stanton E.

1990-09-01

A renewed interest in climatic definitions of the seasons has surfaced in recent years. However, people usually associate biological phenomena and climate with the seasons. Standard seasons, defined as the periods of the year when the climate is within specified bounds, can be delimited in terms of biological phenomena if climatic thresholds are known for the groups of interest. By focusing attention on the time variation they illustrate climatic variation from a different perspective. An example of the type of information provided by standard seasons on the regional scale is given using human thermal standard seasons in the Pacific Basin. The latitudinal control of climate is indicated by the length of the hot and cold seasons. The moderation of maritime climates is seen in the shortness and slower rate of advance and retreat of the hot and cold seasons, and the extended length of the neutral (or spring) season. Standard seasons have widespread application in indicating the times of the year favorable or unfavorable for particular populations or activities. Bioclimatologists can contribute to season definition by expanding the range of information on climate-organism interaction on which seasonal thresholds are based and may find standard seasons useful in presenting the results of many types of investigations.

Growth gains from selective breeding in a spruce hybrid zone do not compromise local adaptation to climate.

PubMed

MacLachlan, Ian R; Yeaman, Sam; Aitken, Sally N

2018-02-01

Hybrid zones contain extensive standing genetic variation that facilitates rapid responses to selection. The Picea glauca  ×  Picea engelmannii hybrid zone in western Canada is the focus of tree breeding programs that annually produce ~90 million reforestation seedlings. Understanding the direct and indirect effects of selective breeding on adaptive variation is necessary to implement assisted gene flow (AGF) polices in Alberta and British Columbia that match these seedlings with future climates. We decomposed relationships among hybrid ancestry, adaptive traits, and climate to understand the implications of selective breeding for climate adaptations and AGF strategies. The effects of selection on associations among hybrid index estimated from ~6,500 SNPs, adaptive traits, and provenance climates were assessed for ~2,400 common garden seedlings. Hybrid index differences between natural and selected seedlings within breeding zones were small in Alberta (average +2%), but larger and more variable in BC (average -7%, range -24% to +1%), slightly favoring P. glauca ancestry. The average height growth gain of selected seedlings over natural seedlings within breeding zones was 36% (range 12%-86%). Clines in growth with temperature-related variables were strong, but differed little between selected and natural populations. Seedling hybrid index and growth trait associations with evapotranspiration-related climate variables were stronger in selected than in natural seedlings, indicating possible preadaptation to drier future climates. Associations among cold hardiness, hybrid ancestry, and cold-related climate variables dominated signals of local adaptation and were preserved in breeding populations. Strong hybrid ancestry-phenotype-climate associations suggest that AGF will be necessary to match interior spruce breeding populations with shifting future climates. The absence of antagonistic selection responses among traits and maintenance of cold adaptation in selected seedlings suggests breeding populations can be safely redeployed using AGF prescriptions similar to those of natural populations.

The impact of temperature on mortality in a subtropical city: effects of cold, heat, and heat waves in São Paulo, Brazil

NASA Astrophysics Data System (ADS)

Son, Ji-Young; Gouveia, Nelson; Bravo, Mercedes A.; de Freitas, Clarice Umbelino; Bell, Michelle L.

2016-01-01

Understanding how weather impacts health is critical, especially under a changing climate; however, relatively few studies have investigated subtropical regions. We examined how mortality in São Paulo, Brazil, is affected by cold, heat, and heat waves over 14.5 years (1996-2010). We used over-dispersed generalized linear modeling to estimate heat- and cold-related mortality, and Bayesian hierarchical modeling to estimate overall effects and modification by heat wave characteristics (intensity, duration, and timing in season). Stratified analyses were performed by cause of death and individual characteristics (sex, age, education, marital status, and place of death). Cold effects on mortality appeared higher than heat effects in this subtropical city with moderate climatic conditions. Heat was associated with respiratory mortality and cold with cardiovascular mortality. Risk of total mortality was 6.1 % (95 % confidence interval 4.7, 7.6 %) higher at the 99th percentile of temperature than the 90th percentile (heat effect) and 8.6 % (6.2, 11.1 %) higher at the 1st compared to the 10th percentile (cold effect). Risks were higher for females and those with no education for heat effect, and males for cold effect. Older persons, widows, and non-hospital deaths had higher mortality risks for heat and cold. Mortality during heat waves was higher than on non-heat wave days for total, cardiovascular, and respiratory mortality. Our findings indicate that mortality in São Paulo is associated with both cold and heat and that some subpopulations are more vulnerable.

An Overview of Signaling Regulons During Cold Stress Tolerance in Plants

PubMed Central

Pareek, Amit; Khurana, Ashima; Sharma, Arun K.; Kumar, Rahul

2017-01-01

Plants, being sessile organisms, constantly withstand environmental fluctuations, including low-temperature, also referred as cold stress. Whereas cold poses serious challenges at both physiological and developmental levels to plants growing in tropical or sub-tropical regions, plants from temperate climatic regions can withstand chilling or freezing temperatures. Several cold inducible genes have already been isolated and used in transgenic approach to generate cold tolerant plants. The conventional breeding methods and marker assisted selection have helped in developing plant with improved cold tolerance, however, the development of freezing tolerant plants through cold acclimation remains an unaccomplished task. Therefore, it is essential to have a clear understanding of how low temperature sensing strategies and corresponding signal transduction act during cold acclimation process. Herein, we synthesize the available information on the molecular mechanisms underlying cold sensing and signaling with an aim that the summarized literature will help develop efficient strategies to obtain cold tolerant plants. PMID:29204079

Beef cattle body temperature during climatic stress: a genome-wide association study.

PubMed

Howard, Jeremy T; Kachman, Stephen D; Snelling, Warren M; Pollak, E John; Ciobanu, Daniel C; Kuehn, Larry A; Spangler, Matthew L

2014-09-01

Cattle are reared in diverse environments and collecting phenotypic body temperature (BT) measurements to characterize BT variation across diverse environments is difficult and expensive. To better understand the genetic basis of BT regulation, a genome-wide association study was conducted utilizing crossbred steers and heifers totaling 239 animals of unknown pedigree and breed fraction. During predicted extreme heat and cold stress events, hourly tympanic and vaginal BT devices were placed in steers and heifers, respectively. Individuals were genotyped with the BovineSNP50K_v2 assay and data analyzed using Bayesian models for area under the curve (AUC), a measure of BT over time, using hourly BT observations summed across 5-days (AUC summer 5-day (AUCS5D) and AUC winter 5-day (AUCW5D)). Posterior heritability estimates were moderate to high and were estimated to be 0.68 and 0.21 for AUCS5D and AUCW5D, respectively. Moderately positive correlations between direct genomic values for AUCS5D and AUCW5D (0.40) were found, although a small percentage of the top 5% 1-Mb windows were in common. Different sets of genes were associated with BT during winter and summer, thus simultaneous selection for animals tolerant to both heat and cold appears possible.

Beef cattle body temperature during climatic stress: a genome-wide association study

NASA Astrophysics Data System (ADS)

Howard, Jeremy T.; Kachman, Stephen D.; Snelling, Warren M.; Pollak, E. John; Ciobanu, Daniel C.; Kuehn, Larry A.; Spangler, Matthew L.

2014-09-01

Cattle are reared in diverse environments and collecting phenotypic body temperature (BT) measurements to characterize BT variation across diverse environments is difficult and expensive. To better understand the genetic basis of BT regulation, a genome-wide association study was conducted utilizing crossbred steers and heifers totaling 239 animals of unknown pedigree and breed fraction. During predicted extreme heat and cold stress events, hourly tympanic and vaginal BT devices were placed in steers and heifers, respectively. Individuals were genotyped with the BovineSNP50K_v2 assay and data analyzed using Bayesian models for area under the curve (AUC), a measure of BT over time, using hourly BT observations summed across 5-days (AUC summer 5-day (AUCS5D) and AUC winter 5-day (AUCW5D)). Posterior heritability estimates were moderate to high and were estimated to be 0.68 and 0.21 for AUCS5D and AUCW5D, respectively. Moderately positive correlations between direct genomic values for AUCS5D and AUCW5D (0.40) were found, although a small percentage of the top 5 % 1-Mb windows were in common. Different sets of genes were associated with BT during winter and summer, thus simultaneous selection for animals tolerant to both heat and cold appears possible.

Is the distribution of nitrogen-fixing cyanobacteria in the oceans related to temperature?

PubMed

Stal, Lucas J

2009-07-01

Approximately 50% of the global natural fixation of nitrogen occurs in the oceans supporting a considerable part of the new primary production. Virtually all nitrogen fixation in the ocean occurs in the tropics and subtropics where the surface water temperature is 25°C or higher. It is attributed almost exclusively to cyanobacteria. This is remarkable firstly because diazotrophic cyanobacteria are found in other environments irrespective of temperature and secondly because primary production in temperate and cold oceans is generally limited by nitrogen. Cyanobacteria are oxygenic phototrophic organisms that evolved a variety of strategies protecting nitrogenase from oxygen inactivation. Free-living diazotrophic cyanobacteria in the ocean are of the non-heterocystous type, namely the filamentous Trichodesmium and the unicellular groups A-C. I will argue that warm water is a prerequisite for these diazotrophic organisms because of the low-oxygen solubility and high rates of respiration allowing the organism to maintain anoxic conditions in the nitrogen-fixing cell. Heterocystous cyanobacteria are abundant in freshwater and brackish environments in all climatic zones. The heterocyst cell envelope is a tuneable gas diffusion barrier that optimizes the influx of both oxygen and nitrogen, while maintaining anoxic conditions inside the cell. It is not known why heterocystous cyanobacteria are absent from the temperate and cold oceans and seas.

[Estimating and projecting the acute effect of cold spells on excess mortality under climate change in Guangzhou].

PubMed

Sun, Q H; Wang, W T; Wang, Y W; Li, T T

2018-04-06

Objective: To estimate future excess mortality attributable to cold spells in Guangzhou, China. Methods: We collected the mortality data and metrological data from 2009-2013 of Guangzhou to calculated the association between cold spell days and non-accidental mortality with GLM model. Then we projected future daily average temperatures (2020-2039 (2020s) , 2050-2069 (2050s) , 2080-2099 (2080s) ) with 5 GCMs models and 2 RCPs (RCP4.5 and RCP8.5) to identify cold spell days. The baseline period was the 1980s (1980-1999). Finally, calculated the yearly cold spells related excess death of 1980s, 2020s, 2050s, and 2080s with average daily death count of non-cold spell days, exposure-response relationship, and yearly number of cold spell days. Results: The average of daily non-accidental mortality in Guangzhou from 2009 to 2013 was 96, and the average of daily average was 22.0 ℃. Cold spell days were associated with 3.3% (95% CI: 0.4%-6.2%) increase in non-accidental mortality. In 1980s, yearly cold spells related deaths were 34 (95% CI: 4-64). In 2020s, the number will increase by 0-10; in 2050s, the number will increase by 1-9; and in 2080s, will increase by 1-9 under the RCP4.5 scenario. In 2020s, the number will increase by 0-9; in 2050s, the number will increase by 1-6; and in 2080s, will increase by 0-11 under the RCP8.5 scenario. Conclusion: The cold spells related non-accidental deaths in Guangzhou will increase in future under climate change.

A new insight into cold stress in poultry production

USDA-ARS?s Scientific Manuscript database

Since growing animals are vulnerable to extreme temperature, climate changes become an important critical constraint to several species in the world. In poultry production, while heat stress has been a rising concern for producers and scientists, cold stress has also caused economic loss worldwide. ...

Evolution of CO2 and H2O on Mars: A cold Early History?

NASA Technical Reports Server (NTRS)

Niles, P. B.; Michalski, J.

2011-01-01

The martian climate has long been thought to have evolved substantially through history from a warm and wet period to the current cold and dry conditions on the martian surface. This view has been challenged based primarily on evidence that the early Sun had a substantially reduced luminosity and that a greenhouse atmosphere would be difficult to sustain on Mars for long periods of time. In addition, the evidence for a warm, wet period of martian history is far from conclusive with many of the salient features capable of being explained by an early cold climate. An important test of the warm, wet early Mars hypothesis is the abundance of carbonates in the crust [1]. Recent high precision isotopic measurements of the martian atmosphere and discoveries of carbonates on the martian surface provide new constraints on the evolution of the martian atmosphere. This work seeks to apply these constraints to test the feasibility of the cold early scenario

A pollen-based biome reconstruction over the last 3.562 million years in the Far East Russian Arctic - new insights into climate-vegetation relationships at the regional scale

NASA Astrophysics Data System (ADS)

Tarasov, P. E.; Andreev, A. A.; Anderson, P. M.; Lozhkin, A. V.; Leipe, C.; Haltia, E.; Nowaczyk, N. R.; Wennrich, V.; Brigham-Grette, J.; Melles, M.

2013-12-01

The recent and fossil pollen data obtained under the frame of the multi-disciplinary international El'gygytgyn Drilling Project represent a unique archive, which allows the testing of a range of pollen-based reconstruction approaches and the deciphering of changes in the regional vegetation and climate. In the current study we provide details of the biome reconstruction method applied to the late Pliocene and Quaternary pollen records from Lake El'gygytgyn. All terrestrial pollen taxa identified in the spectra from Lake El'gygytgyn were assigned to major vegetation types (biomes), which today occur near the lake and in the broader region of eastern and northern Asia and, thus, could be potentially present in this region during the past. When applied to the pollen spectra from the middle Pleistocene to present, the method suggests (1) a predominance of tundra during the Holocene, (2) a short interval during the marine isotope stage (MIS) 5.5 interglacial distinguished by cold deciduous forest, and (3) long phases of taiga dominance during MIS 31 and, particularly, MIS 11.3. These two latter interglacials seem to be some of the longest and warmest intervals in the study region within the past million years. During the late Pliocene-early Pleistocene interval (i.e., ~3.562-2.200 Ma), there is good correspondence between the millennial-scale vegetation changes documented in the Lake El'gygytgyn record and the alternation of cold and warm marine isotope stages, which reflect changes in the global ice volume and sea level. The biome reconstruction demonstrates changes in the regional vegetation from generally warmer/wetter environments of the earlier (i.e., Pliocene) interval towards colder/drier environments of the Pleistocene. The reconstruction indicates that the taxon-rich cool mixed and cool conifer forest biomes are mostly characteristic of the time prior to MIS G16, whereas the tundra biome becomes a prominent feature starting from MIS G6. These results consistently indicate that the study region supported significant tree populations during most of the interval prior to ~2.730 Ma. The cold- and drought-tolerant steppe biome first appears in the reconstruction ~3.298 Ma during the tundra-dominated MIS M2, whereas the tundra biome initially occurs between ~3.379 and ~3.378 Ma within MIS MG4. Prior to ~2.800 Ma, several other cold stages during this generally warm Pliocene interval were characterized by the tundra biome.

Long Term Decline in Eastern US Winter Temperature Extremes.

NASA Astrophysics Data System (ADS)

Trenary, L. L.; DelSole, T. M.; Tippett, M. K.; Doty, B.

2016-12-01

States along the US eastern seaboard have experienced successively harsh winter conditions in recent years. This has prompted speculation that climate change is leading to more extreme winter conditions. In this study we quantify changes in the observed winter extremes over the period 1950-2015, by examining year-to-year differences in intensity, frequency and likelihood of daily cold temperature extremes in the north, mid, and south Atlantic states along the US east coast. Analyzing station data for these three regions, we find that while the north and mid-Atlantic regions experienced record-breaking cold temperatures in 2015, there is no long-term increase in the intensity of cold extremes anywhere along the eastern seaboard. Likewise, despite the record number of cold days in these two regions during 2014 and 2015, there is no systematic increase in the frequency of cold extremes. To determine whether the observed changes are natural or human-forced, we repeat our analysis using a suite of climate simulations, with and without external forcing. Generally, model simulations suggest that human-induced forcing does not significantly influence the range of daily winter temperature. Combining this result with the fact that the observed winter temperatures are becoming warmer and less variable, we conclude that the recent intensification of eastern US cold extremes is only temporary.

Geographic variation in body form of prehistoric Jomon males in the Japanese archipelago: its ecogeographic implications.

PubMed

Fukase, Hitoshi; Wakebe, Tetsuaki; Tsurumoto, Toshiyuki; Saiki, Kazunobu; Fujita, Masaki; Ishida, Hajime

2012-09-01

Diversity of human body size and shape is often biogeographically interpreted in association with climatic conditions. According to Bergmann's and Allen's rules, populations in regions with a cold climate are expected to display an overall larger body and smaller/shorter extremities than those in warm/hot environments. In the present study, the skeletal limb size and proportions of prehistoric Jomon hunter-gatherers, who extensively inhabited subarctic to subtropical areas in the ancient Japanese archipelago, were examined to evaluate whether or not the inter-regional differences follow such ecogeographic patterns. Results showed that the Jomon intralimb proportions including relative distal limb lengths did not differ significantly among five regions from northern Hokkaido to the southern Okinawa Islands. This suggests a limited co-variability of the intralimb proportions with climate, particularly within genealogically close populations. In contrast, femoral head breadth (associated with body mass) and skeletal limb lengths were found to be significantly and positively correlated with latitude, suggesting a north-south geographical cline in the body size. This gradient therefore comprehensively conforms to Bergmann's rule, and may stem from multiple potential factors such as phylogenetic constraints, microevolutionary adaptation to climatic/geographic conditions during the Jomon period, and nutritional and physiological response during ontogeny. Specifically, the remarkably small-bodied Jomon in the Okinawa Islands can also be explained as an adjustment to subtropical and insular environments. Thus, the findings obtained in this study indicate that Jomon people, while maintaining fundamental intralimb proportions, displayed body size variation in concert with ambient surroundings. Copyright © 2012 Wiley Periodicals, Inc.

Thermal thresholds as predictors of seed dormancy release and germination timing: altitude-related risks from climate warming for the wild grapevine Vitis vinifera subsp. sylvestris.

PubMed

Orrù, Martino; Mattana, Efisio; Pritchard, Hugh W; Bacchetta, Gianluigi

2012-12-01

The importance of thermal thresholds for predicting seed dormancy release and germination timing under the present climate conditions and simulated climate change scenarios was investigated. In particular, Vitis vinifera subsp. sylvestris was investigated in four Sardinian populations over the full altitudinal range of the species (from approx. 100 to 800 m a.s.l). Dried and fresh seeds from each population were incubated in the light at a range of temperatures (10-25 and 25/10 °C), without any pre-treatment and after a warm (3 months at 25 °C) or a cold (3 months at 5 °C) stratification. A thermal time approach was then applied to the germination results for dried seeds and the seed responses were modelled according to the present climate conditions and two simulated scenarios of the Intergovernmental Panel on Climate Change (IPCC): B1 (+1·8 °C) and A2 (+3·4 °C). Cold stratification released physiological dormancy, while very few seeds germinated without treatments or after warm stratification. Fresh, cold-stratified seeds germinated significantly better (>80 %) at temperatures ≥20 °C than at lower temperatures. A base temperature for germination (T(b)) of 9·0-11·3 °C and a thermal time requirement for 50 % of germination (θ(50)) ranging from 33·6 °Cd to 68·6 °Cd were identified for non-dormant cold-stratified seeds, depending on the populations. This complex combination of thermal requirements for dormancy release and germination allowed prediction of field emergence from March to May under the present climatic conditions for the investigated populations. The thermal thresholds for seed germination identified in this study (T(b) and θ(50)) explained the differences in seed germination detected among populations. Under the two simulated IPCC scenarios, an altitude-related risk from climate warming is identified, with lowland populations being more threatened due to a compromised seed dormancy release and a narrowed seed germination window.

Analysis of Solar Chimneys in Different Climate Zones - Case of Social Housing in Ecuador

NASA Astrophysics Data System (ADS)

Godoy-Vaca, Luis; Almaguer, Manuel; Martínez-Gómez, Javier; Lobato, Andrea; Palme, Massimo

2017-10-01

The aim of this research is to simulate the performance of a solar chimney located in different macro-zones in Ecuador. The proposed solar chimney model was simulated using a python script in order to predict the temperature distribution and the mass flow over time. The results obtained were firstly compared with experimental data for dry-warm climate. Then, the model was evaluated and tested in real weather conditions: dry-warm, moist-warm and rainy-cold. In addition, the assumed chimney dimensions were chosen according to the literature for the studied conditions. In spite of evaluating the best nightly ventilation, different chimney wall materials were tested: solid brick, common brick and reinforced concrete. The results showed that concrete in a dry-warm climate, a metallic layer on the gap with solid brick in a moist-warm climate and reinforced concrete in a rainy cold climate used for the absorbent wall improve the thermal inertia of the social housing.

Comparison of GPCP Monthly and Daily Precipitation Estimates with High-Latitude Gauge Observations

NASA Technical Reports Server (NTRS)

Bolvin, David T.; Adler, Robert G.; Nelkin, Eric J.; Poutiainen, Jani

2008-01-01

It is very important to know how much rain and snow falls around the world for uses that range from crop forecasting to disaster response, drought monitoring to flood forecasting, and weather analysis to climate research. Precipitation is usually measured with rain gauges, but rain gauges don t exist in areas that are sparsely populated, which tends to be a good portion of the globe. To overcome this, meteorologists use satellite data to estimate global precipitation. However, it is difficult to estimate rain and especially snow in cold climates using most current satellites. The satellite sensors are often "confused" by a snowy or frozen surface and therefore cannot distinguish precipitation. One commonly used satellite-based precipitation data set, the Global Precipitation Climatology Project (GPCP) data, overcomes this frozen-surface problem through the innovative use of two sources of satellite data, the Television Infrared Observation Satellite Operational Vertical Sounder (TOVS) and the Atmospheric Infrared Sounder (AIRS). Though the GPCP estimates are generally considered a very reliable source of precipitation, it has been difficult to assess the quality of these estimates in cold climates due to the lack of gauges. Recently, the Finnish Meteorological Institute (FMI) has provided a 12-year span of high-quality daily rain gauge observations, covering all of Finland, that can be used to compare with the GPCP data to determine how well the satellites estimate cold-climate precipitation. Comparison of the monthly GPCP satellite-based estimates and the FMI gauge observations shows remarkably good agreement, with the GPCP estimates being 6% lower in the amount of precipitation than the FMI observations. Furthermore, the month-to-month correlation between the GPCP and FMI is very high at 0.95 (1.0 is perfect). The daily GPCP estimates replicate the FMI daily occurrences of precipitation with a correlation of 0.55 in the summer and 0.45 in the winter. The winter result indicates the GPCP estimates have skill in "seeing" snowfall, which is the most challenging situation. Thus, the GPCP data set successfully overcomes a current limitation in satellite meteorology, namely the estimation of cold-climate precipitation. The success of the GPCP data set bodes well for future missions, whose instrumentation is specifically designed to give even more information for addressing cold-climate precipitation.

Excess warming in Central Europe after the 8.2 ka cold event: evidence from a varve-dated ostracod δ18O record from Mondsee (Austria)

NASA Astrophysics Data System (ADS)

Lauterbach, Stefan; Andersen, Nils; Erlenkeuser, Helmut; Danielopol, Dan L.; Namiotko, Tadeusz; Hüls, Matthias; Belmecheri, Soumaya; Nantke, Carla; Meyer, Hanno; Chapligin, Bernhard; von Grafenstein, Uli; Brauer, Achim

2017-04-01

As evidenced by numerous palaeoclimate records worldwide, the Holocene warm period has been punctuated by several short, low-amplitude cold episodes. Among these, the so-called 8.2 ka cold event represents a particularly prominent climate anomaly. Accordingly, several proxy-based and modeling studies have addressed its causal mechanisms, absolute dating, duration, amplitude, spatio-temporal characteristics and environmental consequences so far. However, knowledge about the dynamics and causes of subsequent climate recovery is still limited although this is essential for understanding rapid climate change. Here we present a new sub-decadally resolved and precisely dated oxygen isotope (δ18O) record for the interval 7.7-8.7 ka BP derived from benthic ostracods preserved in the varved lake sediments of pre-Alpine Mondsee (Austria), providing new insights into climate development around the 8.2 ka cold event in Central Europe. The high-resolution Mondsee δ18O record reveals the occurrence of a pronounced cold spell around 8.2 ka BP, whose amplitude (˜1.0 ‰ , equivalent to a 1.5-2.0 ˚ C cooling), total duration (151 years) and absolute dating (8231-8080 varve years BP, i.e. calendar years before AD 1950) agrees well with results from other Northern Hemisphere palaeoclimate archives, e.g. the Greenland ice cores. In addition, the Mondsee data set provides evidence for a 75-year-long δ18O overshoot directly following the 8.2 ka event (between 8080 and 8005 varve years BP), which is interpreted as a period of excess warming (about 0.5-0.6 ˚ C above the pre-8.2 ka event level) in Central Europe. Though so far not been explicitly described elsewhere, this observation is consistent with evidence from other proxy records in the North Atlantic realm, therefore likely reflecting a hemispheric-scale signal rather than a local phenomenon. As a possible trigger we suggest an enhanced resumption of the Atlantic meridional overturning circulation (AMOC), supporting assumptions from climate model simulations.

Early establishment response of different Pinus nigra ssp. salzmanii seed sources on contrasting environments: Implications for future reforestation programs and assisted population migration.

PubMed

Taïbi, K; del Campo, A D; Aguado, A; Mulet, J M

2016-04-15

Forest restoration constitutes an important issue within adaptive environmental management for climate change at global scale. However, effective implementation of these programs can only be achieved by revising current seed transfer guidelines, as they lack inherent spatial and temporal dynamics associated with climate change. In this sense, provenance trials may provide key information on the relative performance of different populations and/or genotypes under changing ecological conditions. This study addresses a methodological approach to evaluate early plantation performance and the consequent phenotypic plasticity and the pattern of the adaptation of different seed sources in contrasting environments. To this end, six seed sources of Salzmann pine were tested at three contrasting trial sites testing a hypothetical assisted population migration. Adaptation at each site was assessed through Joint Regression and Additive Main effect and Multiplication Interaction (AMMI) models. Most of the observed variation was attributed to the environment (above 90% for all traits), even so genotype and genotype by environment interaction (GxE) were significant. Seedlings out-planted under better site conditions did not differ in survival but in height growth. However, on sites with higher constraints, survival differed among seed sources and diameter growth was high. The adaptation analyses (AMMI) indicated that the cold-continental seed source 'Soria' performed as a generalist seed source, whereas 'Cordilleras Béticas', the southernmost seed source, was more adapted to harsh environments (frost and drought) in terms of survival. The results supported partially the hypothesis that assisted migration of seed sources makes sense within limited transfer distances, and this was reinforced by the GxE results. The present study could be valuable to address adaptive transfer of seedings in ecological restoration and to determine the suitable seed sources for reforestation programs and assisted population migration under climatic changes. The reported results are based on 3 years' data and need to be considered in this context. Copyright © 2016 Elsevier Ltd. All rights reserved.

Embryonic development rates of northern grasshoppers (Orthoptera: Acrididae): implications for climate change and habitat management

USDA-ARS?s Scientific Manuscript database

Temperature-dependent rates of embryonic development are a primary determinant of the life cycle of many species of grasshoppers which, in cold climates, spend two winters in the egg stage. Knowledge of embryonic developmental rates is important for an assessment of the effects of climate change and...

Organic geochemical investigations of the Dali Lake sediments in northern China: Implications for environment and climate changes of the last deglaciation in the East Asian summer monsoon margin

NASA Astrophysics Data System (ADS)

Fan, Jiawei; Xiao, Jule; Wen, Ruilin; Zhang, Shengrui; Wang, Xu; Cui, Linlin; Yamagata, Hideki

2017-06-01

Millennial-scale environment and climate changes in the East Asian summer monsoon margin during the last deglaciation are reconstructed by systematic studies on the characteristic of sedimentary organic matter from Dali Lake in northern China. Concurrent increases in the TOC and TN concentrations indicate increases in terrestrial organic matter and nutrient inputs to the lake and a development of terrestrial vegetation and phytoplankton productivity related to increases in regional temperature and precipitation. C/N ratios reflect changes in the proportions of terrestrial and aquatic organic matter. Decreases in both δ13Corg and δ15N values indicate increases in the isotopically lighter, terrestrial carbon and nitrogen inputs to the lake, due to increases in surface runoffs; while a sharp decrease in the δ15N value implies a significant weakening in the biological activities of nitrifying and amonifying bacteria, due to abrupt decrease in the water temperature. The geochemical data indicate that regional temperature and precipitation exhibited increasing trends from 15,000 to 12,350 cal yr BP; temperature decreased abruptly at 12,350 cal yr BP and then maintained a low level from 12,350 to 11,400 cal yr BP, precipitation decreased to a relatively low level from 12,350 to 11,400 cal yr BP; and both temperature and precipitation returned to increase after 11,400 cal yr BP. The climate change in the Dali Lake region during the last deglaciation corresponds, within age uncertainties, to the Bølling-Allerød (BA) warm phase and Younger Dryas (YD) cold reversal occurring over northern high latitudes. However, the gradual and mild increasing trends of regional temperature and precipitation during the BA warm period contrasts with the general cooling trend in northern high latitude temperature, implying a dominant influence from increases in the Northern Hemisphere summer insolation; while the slight decreases in regional precipitation relative to the rapid and significant decreases in northern high latitude temperature during the YD cold period may have resulted from local moisture recycling or from an insensitive response of hydrology and ecology to the regional precipitation change.

Is the area of the orbital opening in humans related to climate?

PubMed

Tomaszewska, Agnieszka; Kwiatkowska, Barbara; Jankauskas, Rimantas

2015-01-01

The aim of this study was to evaluate whether climatic conditions impact the size of the anterior orbital opening in humans. The previous research has shown that morphology of the human orbit, a trait strongly related to the shape of the cranium, varies significantly among populations. However, the mechanisms of this variation are still debatable. Besides such evolutionary forces as genetic drift, climatic conditions may be involved. Thermoregulatory processes affect skull shape, and thus may also influence orbital morphology. A total of 846 dry skulls of male and female adults from three climatic areas (i.e., warm, temperate, and cold) of Europe were evaluated. The areas of the left and right orbital openings were measured using the three-dimensional contact scanner MicroScribe G2L, and analyzed with regard to climate. The results reveal a statistically significant association with climatic conditions on the area of orbital opening in accordance with Bergmann's rule. The anterior orbital opening area was smaller in male individuals from the cold climate, and larger in individuals from the warm climate areas. These data may support the hypothesized association between size of the orbital opening and adaptation to different climatic conditions, but only in males. © 2015 Wiley Periodicals, Inc.

Pollen evidence for late pleistocene bering land bridge environments from Norton Sound, Northeastern Bering Sea, Alaska

USGS Publications Warehouse

Ager, T.A.; Phillips, R.L.

2008-01-01

After more than half a century of paleoenvironmental investigations, disagreements persist as to the nature of vegetation type and climate of the Bering land bridge (BLB) during the late Wisconsin (Sartan) glacial interval. Few data exist from sites on the former land bridge, now submerged under the Bering and Chukchi Seas. Two hypotheses have emerged during the past decade. The first, based on pollen data from Bering Sea islands and adjacent mainlands of western Alaska and Northeast Siberia, represents the likely predominant vegetation on the Bering land bridge during full-glacial conditions: graminoid-herb-willow tundra vegetation associated with cold, dry winters and cool, dry summer climate. The second hypothesis suggests that dwarf birch-shrub-herb tundra formed a broad belt across the BLB, and that mesic vegetation was associated with cold, snowier winters and moist, cool summers. As a step towards resolving this controversy, a sediment core from Norton Sound, northeastern Bering Sea was radiocarbon dated and analyzed for pollen content. Two pollen zones were identified. The older, bracketed by radiocarbon ages of 29,500 and 11,515 14C yr BP, contains pollen assemblages composed of grass, sedge, wormwood, willow, and a variety of herb (forb) taxa. These assemblages are interpreted to represent graminoid-herb-willow tundra vegetation that developed under an arid, cool climate regime. The younger pollen zone sediments were deposited about 11,515 14C yr BP, when rising sea level had begun to flood the BLB. This younger pollen zone contains pollen of birch, willow, heaths, aquatic plants, and spores of sphagnum moss. This is interpreted to represent a Lateglacial dwarf birch-heath-willow-herb tundra vegetation, likely associated with a wetter climate with deeper winter snows, and moist, cool summers. This record supports the first hypothesis, that graminoid-herb-willow tundra vegetation extended into the lowlands of the BLB during full glacial conditions of the late Wisconsin. ?? 2008 Regents of the University of Colorado.

UAV applications for thermodynamic profiling: Emphasis on ice fog research

NASA Astrophysics Data System (ADS)

Gultepe, Ismail; Heymsfield, Andrew J.; Fernando, Harindra J. S.; Hoch, Sebastian W.; Ware, Randolph

2016-04-01

Ice fog occurs often over the Arctic, cold climatic, and mountainous regions for about 30% of time where temperature (T) can go down to -10°C or below. Ice Nucleation (IN) and cooling processes play an important role by the controlling the intensity of ice fog conditions that affect aviation application, transportation, and local climate. Ice fog can also occur at T above -10°C but close to 0°C it occurs due to freezing of supercooled droplets that include an IN. To better document ice fog conditions, observations from the ice fog events of the Indirect and Semi-Direct Aerosol effects on Climate (ISDAC) project, Barrow, Alaska, Fog Remote Sensing And Modeling (FRAM) project Yellowknife, Northwest Territories, and the Mountain Terrain Atmospheric Modeling and Observations (MATERHORN) project, Heber City, Utah, were analyzed.. Measurements difficulties of small ice fog particles at cold temperatures and low-level flying restrictions prevent observations from aircraft within the surface boundary layer. However, unmanned Aerial Vehicles (UAVs) can be operated safely to measure IN number concentration, Relative Humidity with respect to ice (RHi), T, horizontal wind speed (Uh) and direction, and ice crystal spectra less than about 500 micron. Thermodynamic profiling by a Radiometrics Profiling Microwave Radiometer (PMWR) and Vaisala CL51 ceilometer was used to describe ice fog conditions in the vertical and its time development. In this presentation, ice fog characteristics and its thermodynamic environment will be presented using both ground-based and airborne platforms such as a UAV with new sensors. Some examples of measurements from the UAV for future research, and challenges related to both ice fog measurements and visibility parameterization will also be presented.

Neuromuscular function during knee extension exercise after cold water immersion.

PubMed

Wakabayashi, Hitoshi; Wijayanto, Titis; Tochihara, Yutaka

2017-06-23

Human adaptability to cold environment has been focused on in the physiological anthropology and related research area. Concerning the human acclimatization process in the natural climate, it is necessary to conduct a research assessing comprehensive effect of cold environment and physical activities in cold. This study investigated the effect of cold water immersion on the exercise performance and neuromuscular function during maximal and submaximal isometric knee extension. Nine healthy males participated in this study. They performed maximal and submaximal (20, 40, and 60% maximal load) isometric knee extension pre- and post-immersion in 23, 26, and 34 °C water. The muscle activity of the rectus femoris (RF) and vastus lateralis (VL) was measured using surface electromyography (EMG). The percentages of the maximum voluntary contraction (%MVC) and mean power frequency (MPF) of EMG data were analyzed. The post-immersion maximal force was significantly lower in 23 °C than in 26 and 34 °C conditions (P < 0.05). The post-immersion %MVC of RF was significantly higher than pre-immersion during 60% maximal exercise in 23 and 26 °C conditions (P < 0.05). In the VL, the post-immersion %MVC was significantly higher than pre-immersion in 23 and 26 °C conditions during 20% maximal exercise and in 26 °C at 40 and 60% maximal intensities (P < 0.05). The post-immersion %MVC of VL was significantly higher in 26 °C than in 34 °C at 20 and 60% maximal load (P < 0.05). The post-immersion MPF of RF during 20% maximal intensity was significantly lower in 23 °C than in 26 and 34 °C conditions (P < 0.05), and significantly different between three water temperature conditions at 40 and 60% maximal intensities (P < 0.05). The post-immersion MPF of VL during three submaximal trials were significantly lower in 23 and 26 °C than in 34 °C conditions (P < 0.05). The lower shift of EMG frequency would be connected with the decrease in the nerve and muscle fibers conduction velocity. To compensate for the impairment of each muscle fibers function, more muscle fibers might be recruited to maintain the working load. This might result in the greater amplitude of EMG after the cold immersion.

Using a Temperature Model and GIS Analysis of Landscape Features to Assess Headwater Resilience to Climate Change in the Driftless Area of Wisconsin

NASA Astrophysics Data System (ADS)

Schuster, Z.; Potter, K. W.

2015-12-01

Cold groundwater discharges in the headwaters of streams in the Driftless Area of Wisconsin help support cold-water fisheries that are valued by anglers throughout the Midwestern U.S. With climate change expected to increase temperatures and threaten the cold-water habitat of species such as brook and brown trout, the Wisconsin Department of Natural Resources is focusing resources on restoration as means of adapting to climate change. One of the challenges they face is a lack of site-specific temperature data in the headwaters streams that they are targeting for restoration activities. Previous work has shown that there is a strong relationship between air and stream temperature. In this study, we calculated weekly mean air-stream temperature relationships for Driftless region headwaters streams and used air temperature projections from a set of statistically-downscaled GCM models to model thermal metrics relevant to fish species suitability described by Lyons et al. (2009) for historical (1961-2000) and future (2046-2065) conditions. We then combined the stream temperature projections with a GIS analysis of physiographic and geologic features to attempt to develop a way of predicting ungaged headwaters streams in the region that are likely to be resilient to temperature increases due to climate change.

Influences of extreme weather, climate and pesticide use on invertebrates in cereal fields over 42 years.

PubMed

Ewald, Julie A; Wheatley, Christopher J; Aebischer, Nicholas J; Moreby, Stephen J; Duffield, Simon J; Crick, Humphrey Q P; Morecroft, Michael B

2015-11-01

Cereal fields are central to balancing food production and environmental health in the face of climate change. Within them, invertebrates provide key ecosystem services. Using 42 years of monitoring data collected in southern England, we investigated the sensitivity and resilience of invertebrates in cereal fields to extreme weather events and examined the effect of long-term changes in temperature, rainfall and pesticide use on invertebrate abundance. Of the 26 invertebrate groups examined, eleven proved sensitive to extreme weather events. Average abundance increased in hot/dry years and decreased in cold/wet years for Araneae, Cicadellidae, adult Heteroptera, Thysanoptera, Braconidae, Enicmus and Lathridiidae. The average abundance of Delphacidae, Cryptophagidae and Mycetophilidae increased in both hot/dry and cold/wet years relative to other years. The abundance of all 10 groups usually returned to their long-term trend within a year after the extreme event. For five of them, sensitivity to cold/wet events was lowest (translating into higher abundances) at locations with a westerly aspect. Some long-term trends in invertebrate abundance correlated with temperature and rainfall, indicating that climate change may affect them. However, pesticide use was more important in explaining the trends, suggesting that reduced pesticide use would mitigate the effects of climate change. © 2015 John Wiley & Sons Ltd.

Paleoecological and climatic implications of stable isotope results from late Pleistocene bone collagen, Ziegeleigrube Coenen, Germany

NASA Astrophysics Data System (ADS)

Wißing, Christoph; Matzerath, Simon; Turner, Elaine; Bocherens, Hervé

2015-07-01

Climatic and ecological conditions during Marine Oxygen Isotope Stage (MIS) 3 are complex and the impact of cold spells on the ecosystems in Central Europe still needs to be investigated thoroughly. Ziegeleigrube Coenen (ZC) is a late Pleistocene MIS 3 locality in the Lower Rhine Embayment of Germany, radiocarbon-dated to > 34 14C ka BP. The site yielded a broad spectrum of mammal species. We investigated the carbon (δ13C), nitrogen (δ15N) and sulfur (δ34S) isotope signatures of bone collagen, since these are valuable tools in characterizing ecological niches, environmental conditions and aspects of climate and mobility. By comparison with pre- and post-Last Glacial Maximum (LGM) sites in Central Europe we show that ZC belongs in a cold event of MIS 3 and was climatically more similar to post-LGM sites than to pre-LGM sites. However, the trophic structure resembled that of typical pre-LGM sites in Belgium. This cold event in MIS 3 changed the bottom of the foodweb, but do not seem to have had a direct impact on the occurrence of the mammalian species and their ecological distribution. Apparently the (mega-) faunal community could adapt also to harsher environmental conditions during MIS 3.

Sensitivity of sediment magnetic records to climate change during Holocene for the northern South China Sea

NASA Astrophysics Data System (ADS)

Ouyang, Tingping; Li, Mingkun; Zhao, Xiang; Zhu, Zhaoyu; Tian, Chengjing; Qiu, Yan; Peng, Xuechao; Hu, Qiao

2016-05-01

Magnetic property has been proved to be a sensitive proxy to climate change for both terrestrial and marine sediments. Based on the schedule frame established by AMS 14C dating of foraminifera, detail magnetic analyses were performed for core PC24 sediments at sampling intervals of 2 cm to discuss magnetic sensitivity of marine sediment to climate during Holocene for the northern South China Sea. The results indicated that: 1) Concentration dependent magnetic parameters are positive corresponding to variation of temperature. The frequency dependent susceptibility coefficient basically reflected the variation in humidity; 2) XARM/SIRM was more sensitive to detrital magnetite particles and SIRM/X was more effective to biogenic magnetite particles. Variations of XARM/SIRM and SIRM/X are corresponding to precipitation and temperature, respectively; 3) the Holocene Megathermal in the study area was identified as 7.5-3.4 cal. ka BP. The warmest stage of Holocene for the study area should be during 6.1 to 3.9 cal. ka BP; 4) The 8 ka cold event was characterized as cold and dry during 8.55 to 8.25 cal. ka BP; 5) During early and middle Holocene, the climate combinations were warm dry and cold wet. It turned to warm and wet after 2.7 cal. ka BP.

Differential Effects of Temperature Extremes on Hospital Admission Rates for Respiratory Disease between Indigenous and Non-Indigenous Australians in the Northern Territory

PubMed Central

Green, Donna; Bambrick, Hilary; Tait, Peter; Goldie, James; Schultz, Rosalie; Webb, Leanne; Alexander, Lisa; Pitman, Andrew

2015-01-01

The health gap between Indigenous and non-Indigenous Australians may be exacerbated by climate change if temperature extremes have disproportionate adverse effects on Indigenous people. To explore this issue, we analysed the effect of temperature extremes on hospital admissions for respiratory diseases, stratified by age, Indigenous status and sex, for people living in two different climates zones in the Northern Territory during the period 1993–2011. We examined admissions for both acute and chronic respiratory diagnoses, controlling for day of the week and seasonality variables. Our analysis showed that: (1) overall, Indigenous hospital admission rates far exceeded non-Indigenous admission rates for acute and chronic diagnoses, and Top End climate zone admission rates exceeded Central Australia climate zone admission rates; (2) extreme cold and hot temperatures were associated with inconsistent changes in admission rates for acute respiratory disease in Indigenous and non-Indigenous children and older adults; and (3) no response to cold or hot temperature extremes was found for chronic respiratory diagnoses. These findings support our two hypotheses, that extreme hot and cold temperatures have a different effect on hospitalisations for respiratory disease between Indigenous and non-Indigenous people, and that these health risks vary between the different climate zones. We did not, however, find that there were differing responses to temperature extremes in the two populations, suggesting that any increased vulnerability to climate change in the Indigenous population of the Northern Territory arises from an increased underlying risk to respiratory disease and an already greater existing health burden. PMID:26633456

The lag effects and vulnerabilities of temperature effects on cardiovascular disease mortality in a subtropical climate zone in China.

PubMed

Huang, Jixia; Wang, Jinfeng; Yu, Weiwei

2014-04-11

This research quantifies the lag effects and vulnerabilities of temperature effects on cardiovascular disease in Changsha--a subtropical climate zone of China. A Poisson regression model within a distributed lag nonlinear models framework was used to examine the lag effects of cold- and heat-related CVD mortality. The lag effect for heat-related CVD mortality was just 0-3 days. In contrast, we observed a statistically significant association with 10-25 lag days for cold-related CVD mortality. Low temperatures with 0-2 lag days increased the mortality risk for those ≥65 years and females. For all ages, the cumulative effects of cold-related CVD mortality was 6.6% (95% CI: 5.2%-8.2%) for 30 lag days while that of heat-related CVD mortality was 4.9% (95% CI: 2.0%-7.9%) for 3 lag days. We found that in Changsha city, the lag effect of hot temperatures is short while the lag effect of cold temperatures is long. Females and older people were more sensitive to extreme hot and cold temperatures than males and younger people.

Microfossils in the Antarctic cold desert: Possible implications for Mars

NASA Technical Reports Server (NTRS)

Friedmann, E. I.; Ocampo-Friedmann, R.

1986-01-01

In the Ross Desert of Antarctica, the principal life form is the cryptoendolithic microbial community in the near-surface layers of porous sandstone rocks. Biological, geological, and climatic factors interact in a complex and precarious balance, making life possible in an otherwise hostile environment. Once this balance is tipped, fossilization sets in. In the reverse case, new colonization of the rock surface may be initiated. As a result, fossilization is contemporary with modern life and both may be simultaneously present in a mosaic pattern. Also, different stages of fossilization are present. The process of fossilization takes place in a nonaquatic environment. If primitive life ever appeared on Mars, it is possible that with increasing aridity, life withdrew into an endolithic niche similar to that in the Antarctic desert. Fossilization in a nonaquatic environment may have set in with the result that traces of past life could be preserved. If such was the case, the study of the fossilization process in Antarctica may hold useful information for the analysis of Martian samples for microfossils.

Penguin heat-retention structures evolved in a greenhouse Earth

PubMed Central

Thomas, Daniel B.; Ksepka, Daniel T.; Fordyce, R. Ewan

2011-01-01

Penguins (Sphenisciformes) inhabit some of the most extreme environments on Earth. The 60+ Myr fossil record of penguins spans an interval that witnessed dramatic shifts in Cenozoic ocean temperatures and currents, indicating a long interplay between penguin evolution and environmental change. Perhaps the most celebrated example is the successful Late Cenozoic invasion of glacial environments by crown clade penguins. A major adaptation that allows penguins to forage in cold water is the humeral arterial plexus, a vascular counter-current heat exchanger (CCHE) that limits heat loss through the flipper. Fossil evidence reveals that the humeral plexus arose at least 49 Ma during a ‘Greenhouse Earth’ interval. The evolution of the CCHE is therefore unrelated to global cooling or development of polar ice sheets, but probably represents an adaptation to foraging in subsurface waters at temperate latitudes. As global climate cooled, the CCHE was key to invasion of thermally more demanding environments associated with Antarctic ice sheets. PMID:21177693

The non-occupational environment and the lung: opportunities for intervention.

PubMed

Kurmi, O P; Ayres, J G

2007-01-01

Many environmental factors, both indoors and outdoors, can cause or worsen respiratory disease. Although in many cases individuals have little influence over environmental exposures (e.g., weather conditions), there are many (such as environmental tobacco smoke (ETS) and outdoor air pollution) where interventions can improve health. While for environmental exposures such as air pollution, remediation largely devolves to the government, for exposures such as ETS advice to individuals in these settings will confer benefit. Climate change has begun to feature more and more in the context of health but how this may affect pulmonary disease remains debatable. It is possible that heat associated changes in allergen exposures may be more than counterbalanced by potential reductions in cold related exacerbations of diseases such as COPD. An improved assessment of environmental exposures is key in how we approach the effects of the environment on lung disease which would allow better understanding of gene-environment interactions and how remediation might influence population health for the better.

Quantitative Trait Loci for Cold Tolerance of Rice Recombinant Inbred Lines in Low Temperature Environments

PubMed Central

Jiang, Wenzhu; Jin, Yong-Mei; Lee, Joohyun; Lee, Kang-Ie; Piao, Rihua; Han, Longzhi; Shin, Jin-Chul; Jin, Rong-De; Cao, Tiehua; Pan, Hong-Yu; Du, Xinglin; Koh, Hee-Jong

2011-01-01

Low temperature is one of the major environmental stresses in rice cultivation in high-altitude and high-latitude regions. In this study, we cultivated a set of recombinant inbred lines (RIL) derived from Dasanbyeo (indica) / TR22183 (japonica) crosses in Yanji (high-latitude area), Kunming (high-altitude area), Chuncheon (cold water irrigation) and Suwon (normal) to evaluate the main effects of quantitative trait loci (QTL) and epistatic QTL (E-QTL) with regard to their interactions with environments for coldrelated traits. Six QTLs for spikelet fertility (SF) were identified in three cold treatment locations. Among them, four QTLs on chromosomes 2, 7, 8, and 10 were validated by several near isogenic lines (NILs) under cold treatment in Chuncheon. A total of 57 QTLs and 76 E-QTLs for nine cold-related traits were identified as distributing on all 12 chromosomes; among them, 19 QTLs and E-QTLs showed significant interactions of QTLs and environments (QEIs). The total phenotypic variation explained by each trait ranged from 13.2 to 29.1% in QTLs, 10.6 to 29.0% in EQTLs, 2.2 to 8.8% in QEIs and 1.0% to 7.7% in E-QTL × environment interactions (E-QEIs). These results demonstrate that epistatic effects and QEIs are important properties of QTL parameters for cold tolerance at the reproductive stage. In order to develop cold tolerant varieties adaptable to wide-ranges of cold stress, a strategy facilitating marker-assisted selection (MAS) is being adopted to accumulate QTLs identified from different environments. PMID:22080374

Trends in Cold Extremes and Winter Weather for the SPTC Region

DOT National Transportation Integrated Search

2017-05-31

Extreme weather poses multifaceted hazards to transportation. There is now increased awareness of the threats of climate variability and change on transportation safety and state of good repair. In particular, a non-stationary climate will potentiall...

Evaluating the Performance of a Climate-Driven Mortality Model during Heat Waves and Cold Spells in Europe

PubMed Central

Lowe, Rachel; Ballester, Joan; Creswick, James; Robine, Jean-Marie; Herrmann, François R.; Rodó, Xavier

2015-01-01

The impact of climate change on human health is a serious concern. In particular, changes in the frequency and intensity of heat waves and cold spells are of high relevance in terms of mortality and morbidity. This demonstrates the urgent need for reliable early-warning systems to help authorities prepare and respond to emergency situations. In this study, we evaluate the performance of a climate-driven mortality model to provide probabilistic predictions of exceeding emergency mortality thresholds for heat wave and cold spell scenarios. Daily mortality data corresponding to 187 NUTS2 regions across 16 countries in Europe were obtained from 1998–2003. Data were aggregated to 54 larger regions in Europe, defined according to similarities in population structure and climate. Location-specific average mortality rates, at given temperature intervals over the time period, were modelled to account for the increased mortality observed during both high and low temperature extremes and differing comfort temperatures between regions. Model parameters were estimated in a Bayesian framework, in order to generate probabilistic simulations of mortality across Europe for time periods of interest. For the heat wave scenario (1–15 August 2003), the model was successfully able to anticipate the occurrence or non-occurrence of mortality rates exceeding the emergency threshold (75th percentile of the mortality distribution) for 89% of the 54 regions, given a probability decision threshold of 70%. For the cold spell scenario (1–15 January 2003), mortality events in 69% of the regions were correctly anticipated with a probability decision threshold of 70%. By using a more conservative decision threshold of 30%, this proportion increased to 87%. Overall, the model performed better for the heat wave scenario. By replacing observed temperature data in the model with forecast temperature, from state-of-the-art European forecasting systems, probabilistic mortality predictions could potentially be made several months ahead of imminent heat waves and cold spells. PMID:25625407

How sea ice could be the cold beating heart of European weather

NASA Astrophysics Data System (ADS)

Margrethe Ringgaard, Ida; Yang, Shuting; Hesselbjerg Christensen, Jens; Kaas, Eigil

2017-04-01

The possibility that the ongoing rapid demise of Arctic sea ice may instigate abrupt changes is, however, not tackled by current research in general. Ice cores from the Greenland Ice Sheet (GIS) show clear evidence of past abrupt warm events with up to 15 degrees warming in less than a decade, most likely triggered by rapid disappearance of Nordic Seas sea ice. At present, both Arctic Sea ice and the GIS are in strong transformation: Arctic sea-ice cover has been retreating during most of the satellite era and in recent years, Arctic sea ice experienced a dramatic reduction and the summer extent was in 2012 and 2016 only half of the 1979-2000 average. With such dramatic change in the current sea ice coverage as a point of departure, several studies have linked reduction in wintertime sea ice in the Barents-Kara seas to cold weather anomalies over Europe and through large scale tele-connections to regional warming elsewhere. Here we aim to investigate if, and how, Arctic sea ice impacts European weather, i.e. if the Arctic sea ice works as the 'cold heart' of European weather. To understand the effects of the sea ice reduction on the full climate system, a fully-coupled global climate model, EC-Earth, is used. A new energy-conserving method for assimilating sea ice using the sensible heat flux is implemented in the coupled climate model and compared to the traditional, non-conserving, method of assimilating sea ice. Using this new method, experiments are performed with reduced sea ice cover in the Barents-Kara seas under both warm and cold conditions in Europe. These experiments are used to evaluate how the Arctic sea ice modulates European winter weather under present climate conditions with a view towards favouring both relatively cold and warm conditions.

Evaluating the performance of a climate-driven mortality model during heat waves and cold spells in Europe.

PubMed

Lowe, Rachel; Ballester, Joan; Creswick, James; Robine, Jean-Marie; Herrmann, François R; Rodó, Xavier

2015-01-23

The impact of climate change on human health is a serious concern. In particular, changes in the frequency and intensity of heat waves and cold spells are of high relevance in terms of mortality and morbidity. This demonstrates the urgent need for reliable early-warning systems to help authorities prepare and respond to emergency situations. In this study, we evaluate the performance of a climate-driven mortality model to provide probabilistic predictions of exceeding emergency mortality thresholds for heat wave and cold spell scenarios. Daily mortality data corresponding to 187 NUTS2 regions across 16 countries in Europe were obtained from 1998-2003. Data were aggregated to 54 larger regions in Europe, defined according to similarities in population structure and climate. Location-specific average mortality rates, at given temperature intervals over the time period, were modelled to account for the increased mortality observed during both high and low temperature extremes and differing comfort temperatures between regions. Model parameters were estimated in a Bayesian framework, in order to generate probabilistic simulations of mortality across Europe for time periods of interest. For the heat wave scenario (1-15 August 2003), the model was successfully able to anticipate the occurrence or non-occurrence of mortality rates exceeding the emergency threshold (75th percentile of the mortality distribution) for 89% of the 54 regions, given a probability decision threshold of 70%. For the cold spell scenario (1-15 January 2003), mortality events in 69% of the regions were correctly anticipated with a probability decision threshold of 70%. By using a more conservative decision threshold of 30%, this proportion increased to 87%. Overall, the model performed better for the heat wave scenario. By replacing observed temperature data in the model with forecast temperature, from state-of-the-art European forecasting systems, probabilistic mortality predictions could potentially be made several months ahead of imminent heat waves and cold spells.

Genetic signature of natural selection in first Americans

PubMed Central

G. Amorim, Carlos Eduardo; Nunes, Kelly; Meyer, Diogo; Comas, David; Bortolini, Maria Cátira; Salzano, Francisco Mauro; Hünemeier, Tábita

2017-01-01

When humans moved from Asia toward the Americas over 18,000 y ago and eventually peopled the New World they encountered a new environment with extreme climate conditions and distinct dietary resources. These environmental and dietary pressures may have led to instances of genetic adaptation with the potential to influence the phenotypic variation in extant Native American populations. An example of such an event is the evolution of the fatty acid desaturases (FADS) genes, which have been claimed to harbor signals of positive selection in Inuit populations due to adaptation to the cold Greenland Arctic climate and to a protein-rich diet. Because there was evidence of intercontinental variation in this genetic region, with indications of positive selection for its variants, we decided to compare the Inuit findings with other Native American data. Here, we use several lines of evidence to show that the signal of FADS-positive selection is not restricted to the Arctic but instead is broadly observed throughout the Americas. The shared signature of selection among populations living in such a diverse range of environments is likely due to a single and strong instance of local adaptation that took place in the common ancestral population before their entrance into the New World. These first Americans peopled the whole continent and spread this adaptive variant across a diverse set of environments. PMID:28193867

Ecological consequences of the expansion of N₂-fixing plants in cold biomes.

PubMed

Hiltbrunner, Erika; Aerts, Rien; Bühlmann, Tobias; Huss-Danell, Kerstin; Magnusson, Borgthor; Myrold, David D; Reed, Sasha C; Sigurdsson, Bjarni D; Körner, Christian

2014-09-01

Research in warm-climate biomes has shown that invasion by symbiotic dinitrogen (N2)-fixing plants can transform ecosystems in ways analogous to the transformations observed as a consequence of anthropogenic, atmospheric nitrogen (N) deposition: declines in biodiversity, soil acidification, and alterations to carbon and nutrient cycling, including increased N losses through nitrate leaching and emissions of the powerful greenhouse gas nitrous oxide (N2O). Here, we used literature review and case study approaches to assess the evidence for similar transformations in cold-climate ecosystems of the boreal, subarctic and upper montane-temperate life zones. Our assessment focuses on the plant genera Lupinus and Alnus, which have become invasive largely as a consequence of deliberate introductions and/or reduced land management. These cold biomes are commonly located in remote areas with low anthropogenic N inputs, and the environmental impacts of N2-fixer invasion appear to be as severe as those from anthropogenic N deposition in highly N polluted areas. Hence, inputs of N from N2 fixation can affect ecosystems as dramatically or even more strongly than N inputs from atmospheric deposition, and biomes in cold climates represent no exception with regard to the risk of being invaded by N2-fixing species. In particular, the cold biomes studied here show both a strong potential to be transformed by N2-fixing plants and a rapid subsequent saturation in the ecosystem's capacity to retain N. Therefore, analogous to increases in N deposition, N2-fixing plant invasions must be deemed significant threats to biodiversity and to environmental quality.

Near-term acceleration of hydroclimatic change in the western U.S.

NASA Astrophysics Data System (ADS)

Ashfaq, Moetasim; Ghosh, Subimal; Kao, Shih-Chieh; Bowling, Laura C.; Mote, Philip; Touma, Danielle; Rauscher, Sara A.; Diffenbaugh, Noah S.

2013-10-01

Given its large population, vigorous and water-intensive agricultural industry, and important ecological resources, the western United States presents a valuable case study for examining potential near-term changes in regional hydroclimate. Using a high-resolution, hierarchical, five-member ensemble modeling experiment that includes a global climate model (Community Climate System Model), a regional climate model (RegCM), and a hydrological model (Variable Infiltration Capacity model), we find that increases in greenhouse forcing over the next three decades result in an acceleration of decreases in spring snowpack and a transition to a substantially more liquid-dominated water resources regime. These hydroclimatic changes are associated with increases in cold-season days above freezing and decreases in the cold-season snow-to-precipitation ratio. The changes in the temperature and precipitation regime in turn result in shifts toward earlier snowmelt, base flow, and runoff dates throughout the region, as well as reduced annual and warm-season snowmelt and runoff. The simulated hydrologic response is dominated by changes in temperature, with the ensemble members exhibiting varying trends in cold-season precipitation over the next three decades but consistent negative trends in cold-season freeze days, cold-season snow-to-precipitation ratio, and 1 April snow water equivalent. Given the observed impacts of recent trends in snowpack and snowmelt runoff, the projected acceleration of hydroclimatic change in the western U.S. has important implications for the availability of water for agriculture, hydropower, and human consumption, as well as for the risk of wildfire, forest die-off, and loss of riparian habitat.

Ecological consequences of the expansion of N2-fixing plants in cold biomes

USGS Publications Warehouse

Hiltbrunner, Erika; Aerts, Rien; Bühlmann, Tobias; Huss-Danell, Kerstin; Magnusson, Borgthor; Myrold, David D.; Reed, Sasha C.; Sigurdsson, Bjarni D.; Körner, Christian

2014-01-01

Research in warm-climate biomes has shown that invasion by symbiotic dinitrogen (N2)-fixing plants can transform ecosystems in ways analogous to the transformations observed as a consequence of anthropogenic, atmospheric nitrogen (N) deposition: declines in biodiversity, soil acidification, and alterations to carbon and nutrient cycling, including increased N losses through nitrate leaching and emissions of the powerful greenhouse gas nitrous oxide (N2O). Here, we used literature review and case study approaches to assess the evidence for similar transformations in cold-climate ecosystems of the boreal, subarctic and upper montane-temperate life zones. Our assessment focuses on the plant genera Lupinus and Alnus, which have become invasive largely as a consequence of deliberate introductions and/or reduced land management. These cold biomes are commonly located in remote areas with low anthropogenic N inputs, and the environmental impacts of N2-fixer invasion appear to be as severe as those from anthropogenic N deposition in highly N polluted areas. Hence, inputs of N from N2 fixation can affect ecosystems as dramatically or even more strongly than N inputs from atmospheric deposition, and biomes in cold climates represent no exception with regard to the risk of being invaded by N2-fixing species. In particular, the cold biomes studied here show both a strong potential to be transformed by N2-fixing plants and a rapid subsequent saturation in the ecosystem’s capacity to retain N. Therefore, analogous to increases in N deposition, N2-fixing plant invasions must be deemed significant threats to biodiversity and to environmental quality.

Relationship between carbohydrate concentration and root growth potential in coniferous seedlings from three climates during cold hardening and dehardening

Treesearch

R.W. Tinus; K.E. Burr; N. Atzmon; J. Riov

2000-01-01

Greenhouse-cultured, container-grown seedlings of Aleppo pine (Pinus halepensis Mill.), radiata pine (Pinus radiata D. Don), and interior Douglas fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) were cold acclimated and deacclimated in growth chambers over 24 weeks....

Extremely cold and hot temperatures increase the risk of ischaemic heart disease mortality: epidemiological evidence from China.

PubMed

Guo, Yuming; Li, Shanshan; Zhang, Yanshen; Armstrong, Ben; Jaakkola, Jouni J K; Tong, Shilu; Pan, Xiaochuan

2013-02-01

To examine the effects of extremely cold and hot temperatures on ischaemic heart disease (IHD) mortality in five cities (Beijing, Tianjin, Shanghai, Wuhan and Guangzhou) in China; and to examine the time relationships between cold and hot temperatures and IHD mortality for each city. A negative binomial regression model combined with a distributed lag non-linear model was used to examine city-specific temperature effects on IHD mortality up to 20 lag days. A meta-analysis was used to pool the cold effects and hot effects across the five cities. 16 559 IHD deaths were monitored by a sentinel surveillance system in five cities during 2004-2008. The relationships between temperature and IHD mortality were non-linear in all five cities. The minimum-mortality temperatures in northern cities were lower than in southern cities. In Beijing, Tianjin and Guangzhou, the effects of extremely cold temperatures were delayed, while Shanghai and Wuhan had immediate cold effects. The effects of extremely hot temperatures appeared immediately in all the cities except Wuhan. Meta-analysis showed that IHD mortality increased 48% at the 1st percentile of temperature (extremely cold temperature) compared with the 10th percentile, while IHD mortality increased 18% at the 99th percentile of temperature (extremely hot temperature) compared with the 90th percentile. Results indicate that both extremely cold and hot temperatures increase IHD mortality in China. Each city has its characteristics of heat effects on IHD mortality. The policy for response to climate change should consider local climate-IHD mortality relationships.

Life-history correlations with seasonal cold hardiness in maritime pine.

PubMed

Prada, Eva; Climent, José; Alía, Ricardo; Díaz, Raquel

2016-12-01

Plants have developed mechanisms to withstand stressful environmental conditions, but the high energetic cost of these mechanisms may involve exchanges with other key functions. While trade-offs between cold hardiness and growth rates are a general assumption, we lack information regarding genetically based trade-offs between cold hardiness and other life-history traits. Such information has strong implications for tree conservation and breeding, especially in the context of ongoing climate change. We used a common garden progeny test to examine the relationships between seasonal cold hardiness and life-history traits of growth, reproduction, juvenile ontogeny, and phenology in 75 families of six maritime pine (Pinus pinaster Ait.) populations, three of continental and three of coastal origins. We found a clear differentiation among populations with regard to cold hardiness and life-history traits. Two continental Iberian populations showed high cold tolerance and slower growth, but faster ontogenetic development in relation to both vegetative heteroblastic change in juveniles and the onset of female reproduction. The coastal populations displayed the opposite behavior, while the continental Moroccan population presented a unique combination of traits. We confirmed trade-offs between cold-hardiness and growth at the population level, but not within populations. There were no trade-offs with other life-history traits at either level. Relevant local adaptation syndromes were identified in the relationship between cold hardiness and life-history traits. These should be considered in developing tree management guidelines aimed at increasing productivity or adaptability under the expected conditions of climate change. © 2016 Botanical Society of America.

Hot Talk, Cold Science

NASA Astrophysics Data System (ADS)

Oglesby, Robert J.

One of the hottest topics in climate science is understanding and evaluating the impacts of possible global warming caused by anthropogenic emissions of greenhouse gases. In Hot Talk, Cold Science, S. Fred Singer does not accept global warming. Singer says in his preface, “The purpose of this book is to demonstrate that the evidence [for global warming] is neither settled, nor compelling, nor even convincing. On the contrary, scientists continue to discover new mechanisms for climate change and to put forth new theories to try to account for the fact that global temperature is not rising, even though greenhouse theory says it should”.

Strong but diverging clonality - climate relationships of different plant clades explain weak overall pattern across China.

PubMed

Ye, Duo; Liu, Guofang; Song, Yao-Bin; Cornwell, William K; Dong, Ming; Cornelissen, Johannes H C

2016-06-01

The clonal strategy should be relatively important in stressful environments (i.e. of low resource availability or harsh climate), e.g. in cold habitats. However, our understanding of the distribution pattern of clonality along environmental gradients is still far from universal. The weakness and inconsistency of overall clonality-climate relationships across taxa, as reported in previous studies, may be due to different phylogenetic lineages having fundamental differences in functional traits other than clonality determining their climate response. Thus, in this study we compared the clonality-climate relationships along a latitudinal gradient within and between different lineages at several taxonomic levels, including four major angiosperm lineages (Magnoliidae, Monocotyledoneae, Superrosidae and Superasteridae), orders and families. To this aim we used a species clonality dataset for 4015 vascular plant species in 545 terrestrial communities across China. Our results revealed clear predictive patterns of clonality proportion in relation to environmental gradients for the predominant representatives of each of the taxonomic levels above, but the relationships differed in shape and strength between the 4 major angiosperm lineages, between the 12 orders and between the 12 families. These different relationships canceled out one another when all lineages at a certain taxonomic level were pooled. Our findings highlight the importance of explicitly accounting for the functional or taxonomic scale for studying variation in plant ecological strategy across environmental gradients.

Anticipated climate warming effects on bull trout habitats and populations across the interior Columbia River basin

Treesearch

Bruce E. Rieman; Daniel Isaak; Susan Adams; Dona Horan; David Nagel; Charles Luce; Deborah Myers

2007-01-01

A warming climate could profoundly affect the distribution and abundance of many fishes. Bull trout Salvelinus confluentus may be especially vulnerable to climate change given that spawning and early rearing are constrained by cold water temperatures creating a patchwork of natal headwater habitats across river networks. Because the size and...

Climate change and bark beetles of the western United States and Canada: Direct and indirect effects

Treesearch

Barbara J. Bentz; Jacques Regniere; Christopher J. Fettig; E. Matthew Hansen; Jane L. Hayes; Jeffrey A. Hicke; Rick G. Kelsey; Jose F. Negron; Steven J. Seybold

2010-01-01

Climatic changes are predicted to significantly affect the frequency and severity of disturbances that shape forest ecosystems. We provide a synthesis of climate change effects on native bark beetles, important mortality agents of conifers in western North America. Because of differences in temperature-dependent life-history strategies, including cold-induced mortality...

Projected climate-induced habitat loss for salmonids in the John Day River network, Oregon, U.S.A.

USGS Publications Warehouse

Ruesch, Aaron S.; Torgersen, Christian E.; Lawler, Joshua J.; Olden, Julian D.; Peterson, Erin E.; Volk, Carol J.; Lawrence, David J.

2012-01-01

Climate change will likely have profound effects on cold-water species of freshwater fishes. As temperatures rise, cold-water fish distributions may shift and contract in response. Predicting the effects of projected stream warming in stream networks is complicated by the generally poor correlation between water temperature and air temperature. Spatial dependencies in stream networks are complex because the geography of stream processes is governed by dimensions of flow direction and network structure. Therefore, forecasting climate-driven range shifts of stream biota has lagged behind similar terrestrial modeling efforts. We predicted climate-induced changes in summer thermal habitat for 3 cold-water fish species—juvenile Chinook salmon, rainbow trout, and bull trout (Oncorhynchus tshawytscha, O. mykiss, and Salvelinus confluentus, respectively)—in the John Day River basin, northwestern United States. We used a spatially explicit statistical model designed to predict water temperature in stream networks on the basis of flow and spatial connectivity. The spatial distribution of stream temperature extremes during summers from 1993 through 2009 was largely governed by solar radiation and interannual extremes of air temperature. For a moderate climate change scenario, estimated declines by 2100 in the volume of habitat for Chinook salmon, rainbow trout, and bull trout were 69–95%, 51–87%, and 86–100%, respectively. Although some restoration strategies may be able to offset these projected effects, such forecasts point to how and where restoration and management efforts might focus.

The relationship between climate change and wars waged between nomadic and farming groups from the Western Han Dynasty to the Tang Dynasty period

NASA Astrophysics Data System (ADS)

Su, Y.; Liu, L.; Fang, X. Q.; Ma, Y. N.

2016-01-01

In ancient China, shifts in regional productivity of agriculture and animal husbandry, caused by climate change, either led to wars or peaceful relations between nomadic and farming groups. During the period spanning the Western Han Dynasty to the Tang Dynasty, 367 wars were waged between these groups. While 69 % of the wars were initiated by nomads, 62.4 % were won by the farming groups. On a centennial timescale, the battlegrounds were mostly in northern areas (at an average latitude of 38.92° N) during warm periods, moving southward (at an average latitude of 34.66° N) during cold periods. On a decadal timescale, warm climates corresponded to a high incidence of wars (a correlation coefficient of 0.293). While farming groups were inclined to initiate wars during dry and cold periods, their chances of achieving victory were reduced at such times. The main reasons for this are, first, that a warm climate provided a solid material foundation for nomadic and farming groups, contributing especially to enhanced productivity among the former. However, the overriding desire of nomadic groups to expand essential subsistence means led to wars. Second, during cold periods, farming groups moved to and settled in the south, while nomadic groups occupied the Central Plain. Thus, the locations of the battlefields also changed. While other factors also influenced these wars, climate change served as a backdrop, playing an indirect role in wars between these groups.

Mobile Robot for Exploring Cold Liquid/Solid Environments

NASA Technical Reports Server (NTRS)

Bergh, Charles; Zimmerman, Wayne

2006-01-01

The Planetary Autonomous Amphibious Robotic Vehicle (PAARV), now at the prototype stage of development, was originally intended for use in acquiring and analyzing samples of solid, liquid, and gaseous materials in cold environments on the shores and surfaces, and at shallow depths below the surfaces, of lakes and oceans on remote planets. The PAARV also could be adapted for use on Earth in similar exploration of cold environments in and near Arctic and Antarctic oceans and glacial and sub-glacial lakes.

Low temperature tolerance, cold hardening and acclimation in tadpoles of the neotropical túngara frog (Engystomops pustulosus).

PubMed

Vo, Pacific; Gridi-Papp, Marcos

2017-05-01

Many frogs from temperate climates can tolerate low temperatures and increase their thermal tolerance through hardening and acclimation. Most tropical frogs, on the other hand, fail to acclimate to low temperatures. This lack of acclimation ability is potentially due to lack of selection pressure for acclimation because cold weather is less common in the tropics. We tested the generality of this pattern by characterizing the critical temperature minimum (CTMin), hardening, and acclimation responses of túngara frogs (Engystomops pustulosus). These frogs belong to a family with unknown thermal ecology. They are found in a tropical habitat with a highly constant temperature regime. The CTMin of the tadpoles was on average 12.5°C. Pre-metamorphic tadpoles hardened by 1.18°C, while metamorphic tadpoles hardened by 0.36°C. When raised at 21°C, tadpoles acclimated expanding their cold tolerance by 1.3°C in relation to larvae raised at 28°C. These results indicate that the túngara frog has a greatly reduced cold tolerance when compared to species from temperate climates, but it responds to cold temperatures with hardening and acclimation comparable to those of temperate-zone species. Cold tolerance increased with body length but cold hardening was more extensive in pre-metamorphic tadpoles than in metamorphic ones. This study shows that lack of acclimation ability is not general to the physiology of tropical anurans. Copyright © 2017 Elsevier Ltd. All rights reserved.

Climatological temperature senstivity of soil carbon turnover: Observations, simple scaling models, and ESMs

NASA Astrophysics Data System (ADS)

Koven, C. D.; Hugelius, G.; Lawrence, D. M.; Wieder, W. R.

2016-12-01

The projected loss of soil carbon to the atmosphere resulting from climate change is a potentially large but highly uncertain feedback to warming. The magnitude of this feedback is poorly constrained by observations and theory, and is disparately represented in Earth system models. To assess the likely long-term response of soils to climate change, spatial gradients in soil carbon turnover times can identify broad-scale and long-term controls on the rate of carbon cycling as a function of climate and other factors. Here we show that the climatological temperature control on carbon turnover in the top meter of global soils is more sensitive in cold climates than in warm ones. We present a simplified model that explains the high cold-climate sensitivity using only the physical scaling of soil freeze-thaw state across climate gradients. Critically, current Earth system models (ESMs) fail to capture this pattern, however it emerges from an ESM that explicitly resolves vertical gradients in soil climate and turnover. The weak tropical temperature sensitivity emerges from a different model that explicitly resolves mineralogical control on decomposition. These results support projections of strong future carbon-climate feedbacks from northern soils and demonstrate a method for ESMs to capture this emergent behavior.

Changes in Concurrent Precipitation and Temperature Extremes

DOE PAGES

Hao, Zengchao; AghaKouchak, Amir; Phillips, Thomas J.

2013-08-01

While numerous studies have addressed changes in climate extremes, analyses of concurrence of climate extremes are scarce, and climate change effects on joint extremes are rarely considered. This study assesses the occurrence of joint (concurrent) monthly continental precipitation and temperature extremes in Climate Research Unit (CRU) and University of Delaware (UD) observations, and in 13 Coupled Model Intercomparison Project Phase 5 (CMIP5) global climate simulations. Moreover, the joint occurrences of precipitation and temperature extremes simulated by CMIP5 climate models are compared with those derived from the CRU and UD observations for warm/wet, warm/dry, cold/wet, and cold/dry combinations of joint extremes.more » The number of occurrences of these four combinations during the second half of the 20th century (1951–2004) is assessed on a common global grid. CRU and UD observations show substantial increases in the occurrence of joint warm/dry and warm/wet combinations for the period 1978–2004 relative to 1951–1977. The results show that with respect to the sign of change in the concurrent extremes, the CMIP5 climate model simulations are in reasonable overall agreement with observations. The results reveal notable discrepancies between regional patterns and the magnitude of change in individual climate model simulations relative to the observations of precipitation and temperature.« less

Integrating new indicators of predictors that shape the public's perception of local extreme temperature in China.

PubMed

Ban, Jie; Huang, Lei; Chen, Chen; Guo, Yuming; He, Mike Z; Li, Tiantian

2017-02-01

The public's risk perception of local extreme heat or cold plays a critical role in community health and prevention under climate change. However, there is limited evidence on such issues in China where extreme weather is occurring more frequently due to climate change. Here, a total of 2500 residents were selected using a three-step sampling method and investigated by a questionnaire in two representative cities. We investigated risk perception of extreme heat in Beijing and extreme cold in Harbin in 2013, aiming to examine their possible correlations with multiple epidemiological factors. We found that exposure, vulnerability, and adaptive ability were significant predictors in shaping public risk perceptions of local extreme temperature. In particular, a 1°C increase in daily temperature resulted in an increased odds of perceiving serious extreme heat in Beijing (OR=1.091; 95% CI: 1.032, 1.153), while a 1°C increase in daily temperature resulted in a decreased odds of perceiving serious extreme cold in Harbin (OR=0.965; 95% CI: 0.939, 0.992). Therefore for both extreme heat and cold, frequent local extreme temperature exposure may amplify a stronger communication. Health interventions for extreme temperature should consider exposure, vulnerability, and adaptive ability factors. This will help improve the public's perception of climatic changes and their willingness to balance adaption and mitigation appropriately. Copyright © 2016 Elsevier B.V. All rights reserved.

Eastern Pacific cooling and Atlantic overturning circulation during the last deglaciation.

PubMed

Kienast, Markus; Kienast, Stephanie S; Calvert, Stephen E; Eglinton, Timothy I; Mollenhauer, Gesine; François, Roger; Mix, Alan C

2006-10-19

Surface ocean conditions in the equatorial Pacific Ocean could hold the clue to whether millennial-scale global climate change during glacial times was initiated through tropical ocean-atmosphere feedbacks or by changes in the Atlantic thermohaline circulation. North Atlantic cold periods during Heinrich events and millennial-scale cold events (stadials) have been linked with climatic changes in the tropical Atlantic Ocean and South America, as well as the Indian and East Asian monsoon systems, but not with tropical Pacific sea surface temperatures. Here we present a high-resolution record of sea surface temperatures in the eastern tropical Pacific derived from alkenone unsaturation measurements. Our data show a temperature drop of approximately 1 degrees C, synchronous (within dating uncertainties) with the shutdown of the Atlantic meridional overturning circulation during Heinrich event 1, and a smaller temperature drop of approximately 0.5 degrees C synchronous with the smaller reduction in the overturning circulation during the Younger Dryas event. Both cold events coincide with maxima in surface ocean productivity as inferred from 230Th-normalized carbon burial fluxes, suggesting increased upwelling at the time. From the concurrence of equatorial Pacific cooling with the two North Atlantic cold periods during deglaciation, we conclude that these millennial-scale climate changes were probably driven by a reorganization of the oceans' thermohaline circulation, although possibly amplified by tropical ocean-atmosphere interaction as suggested before.

Thermohaline circulation: a missing equation and its climate-change implications

NASA Astrophysics Data System (ADS)

Ou, Hsien-Wang

2018-01-01

We formulate a box model of coupled ocean-atmosphere to examine the differential fields interactive with the thermohaline circulation (THC) and their response to global warming. We discern a robust convective bound on the atmospheric heat transport, which would divide the climate regime into warm and cold branches; but unlike the saline mode of previous box models, the cold state, if allowed, has the same-signed—though weaker—density contrast and THC as the present climate, which may explain its emergence from coupled general circulation models. We underscore the nondeterminacy of the THC due to random eddy shedding and apply the fluctuation theorem to constrain the shedding rate, thus closing the problem. The derivation reveals an ocean propelled toward the maximum entropy production (MEP) on millennial timescale (termed "MEP-adjustment"), the long timescale arising from the compounding effect of microscopic fluctuations in the shedding rate and their slight probability bias. Global warming may induce hysteresis between the two branches, like that seen in GCMs, but the cold transition is far more sensitive to the moistening than the heating effects as the latter would be countered by the hydrological feedback. The uni- or bi-modality of the current state—hence whether the THC may recover after the cold transition—depends on the global-mean convective flux and may not be easily assessed due to its observed uncertainty.

Climate change and health in Israel: adaptation policies for extreme weather events

PubMed Central

2013-01-01

Climatic changes have increased the world-wide frequency of extreme weather events such as heat waves, cold spells, floods, storms and droughts. These extreme events potentially affect the health status of millions of people, increasing disease and death. Since mitigation of climate change is a long and complex process, emphasis has recently been placed on the measures required for adaptation. Although the principles underlying these measures are universal, preparedness plans and policies need to be tailored to local conditions. In this paper, we conducted a review of the literature on the possible health consequences of extreme weather events in Israel, where the conditions are characteristic of the Mediterranean region. Strong evidence indicates that the frequency and duration of several types of extreme weather events are increasing in the Mediterranean Basin, including Israel. We examined the public health policy implications for adaptation to climate change in the region, and proposed public health adaptation policy options. Preparedness for the public health impact of increased extreme weather events is still relatively limited and clear public health policies are urgently needed. These include improved early warning and monitoring systems, preparedness of the health system, educational programs and the living environment. Regional collaboration should be a priority. PMID:23805950

Research on Energy-saving Shape Design of High School Library Building in Cold Region

NASA Astrophysics Data System (ADS)

Hui, Zhao; Weishuang, Xie; Zirui, Tong

2017-11-01

Considering climatic characteristics in cold region, existing high school libraries in Changchun are researched according to investigation of real conditions of these library buildings. Mathematical analysis and CAD methods are used to summarize the relation between building shape and building energy saving of high school library. Strategies are put forward for sustainable development of high school library building in cold region, providing reliable design basis for construction of high school libraries in Changchun.

Vegetation and climate history in arid western China during MIS2: New insights from pollen and grain-size data of the Balikun Lake, eastern Tien Shan

NASA Astrophysics Data System (ADS)

Zhao, Yongtao; An, Cheng-Bang; Mao, Limi; Zhao, Jiaju; Tang, Lingyu; Zhou, Aifeng; Li, Hu; Dong, Weimiao; Duan, Futao; Chen, Fahu

2015-10-01

Marine Isotope Stage (MIS) 2 is mostly a cold period encompassing the Last Glacial Maximum (LGM), but the regional expression of MIS2 in arid areas of China is not well known. In this paper, we use high-resolution lacustrine pollen and grain-size records from Balikun Lake to infer vegetation, lake evolution, and climate in arid western China during MIS2. Our results suggest that: 1) the regional vegetation around Balikun was mainly dominated by desert and/or desert-steppe, and Balikun Lake was relatively shallow and experienced high aeolian input during MIS2; 2) distinctive runoff from mountain glacial meltwater in the eastern parts of the Balikun basin caused a high relative abundance of Artemisia pollen during the LGM (26.5-19.2 cal kyr BP), while simultaneously the desert areas expanded as indicated by the high abundance of desert shrubs (e.g., Elaeagnaceae, Rhamnaceae, Hippophae). This cold and dry LGM climate triggered a substantial lowering of lake level; 3) an extremely cold and dry climate prevailing from 17.0 to 15.2 cal kyr BP, correlated with Heinrich event 1 (H1), would explain the low vegetation cover found then; and 4) the warm and humid Bølling/Allerød interstadial (BA: ca. 15-ca. 13 cal kyr BP) is clearly recorded in the Balikun region by the development of wetland herb communities (e.g., Poaceae, Cyperaceae, Typha), and the lake level rose due to increased runoff. Our results challenge the traditional view of cold and wet climatic conditions and high lake levels in arid western China during the LGM, and we propose that changes in local temperature modulated by July insolation was an indispensable factor in triggering vegetation evolution in the Balikun region during MIS2.

Elevated risk of high blood pressure: climate and the inverse housing law.

PubMed

Mitchell, Richard; Blane, David; Bartley, Mel

2002-08-01

In previous work the authors identified an 'inverse housing law' in Britain such that housing quality tends to be worse in areas of harsh climate than in areas where the climate is more benign. This study investigates whether an individual's risk of hypertension is associated with such a 'mismatch' between the quality of their housing and the climate to which they have been exposed. Cross-sectional observational study based on Britain. Data came from the 5663 Health and Lifestyle Survey (HALS) participants for whom all relevant items were available. A two-stage study design was employed. First, the relationship between exposure to colder climate and housing quality was established. Second, the impact on risk of hypertension was determined for level of exposure to colder climate and housing quality. Analysis confirmed that amongst survey respondents, those with greater exposure to colder climate are more likely (1.32, 95% CI: 1.18-1.42) to live in poor quality housing than those with lower exposure to colder climate. This combination of higher exposure to colder climate plus residence in worse quality housing raises significantly the risk of diastolic hypertension (1.45, 95% CI: 1.18-1.77) and, more weakly, systolic hypertension (1.25, 95% CI: 1.01-1.53). There appears to be an 'inverse housing law' in Britain, whereby longer term residents of relatively cold areas are also more likely to live in worse quality housing and this combination of circumstances is associated with significantly higher risk of diastolic hypertension. The findings provide an example of how long term exposure to an adverse environment, which may stem from material disadvantage, can damage health.

Wet and cold climate conditions recorded by coral geochemical proxies during the beginning of the first millennium CE in the northern South China Sea

NASA Astrophysics Data System (ADS)

Xiao, Hangfang; Deng, Wenfeng; Chen, Xuefei; Wei, Gangjian; Zeng, Ti; Zhao, Jian-xin

2017-03-01

The past two millennia include some distinct climate intervals, such as the Medieval Warm Period (MWP) and the Little Ice Age (LIA), which were caused by natural forcing factors, as well as the Current Warm Period (CWP) that has been linked to anthropogenic factors. Therefore, this period has been of great interest to climate change researchers. However, most studies are based on terrestrial proxy records, historical documentary data, and simulation results, and the ocean and the tropical record are very limited. The Eastern Han, Three Kingdoms, and Western Jin periods (25-316 CE) cover the beginning first millennium CE in China, and were characterized by a cold climate and frequent wars and regime changes. This study used paired Sr/Ca and δ18O series recovered from a fossil coral to reconstruct the sea surface water conditions during the late Eastern Han to Western Jin periods (167-309 CE) at Wenchang, eastern Hainan Island in the northern South China Sea (SCS), to investigate climate change at this time. The long-term sea surface temperature (SST) during the study interval was 25.1 °C, which is about 1.5 °C lower than that of the CWP (26.6 °C). Compared with the average value of 0.40‰ during the CWP, the long-term average seawater δ18O (-0.06‰) was more negative. These results indicate that the climate conditions during the study period were cold and wet and comparable with those of the LIA. This colder climate may have been associated with the weaker summer solar irradiance. The wet conditions were caused by the reduced northward shift of the intertropical convergence zone/monsoon rainbelt associated with the retreat of the East Asian summer monsoon. Interannual and interdecadal climate variability may also have contributed to the variations in SST and seawater δ18O recorded over the study period.

Unraveling the Diversity of Early Aqueous Environments and Climate on Mars Through the Phyllosilicate Record

NASA Technical Reports Server (NTRS)

Bishop, J. L.; Baker, L. L.; Fairén, A. G.; Gross, C.; Velbel, M. A.; Rampe, E. B.; Michalski, J. R.

2017-01-01

Were Martian phyllosilicates formed on the surface or subsurface? Was early Mars warm or cold? How long was liquid water present on the surface of Mars? These are some of the many open questions about our neighboring planet. We propose that the mineralogy of the clay-bearing outcrops on Mars can help address these questions. Abundant phyllosilicates and aqueous minerals are observed nearly everywhere we can see the ancient rocks on Mars. Most bountiful among these is Fe/Mg-smectite. In this study we evaluate the nature and stratigraphy of clay outcrops observed on Mars and the presence of mixtures of other clays or other minerals with the ubiquitous Fe/Mg-smectite.

How Does Snow Persistence Relate to Annual Streamflow in Mountain Watersheds of the Western U.S. With Wet Maritime and Dry Continental Climates?

NASA Astrophysics Data System (ADS)

Hammond, John C.; Saavedra, Freddy A.; Kampf, Stephanie K.

2018-04-01

With climate warming, many regions are experiencing changes in snow accumulation and persistence. These changes are known to affect streamflow volume, but the magnitude of the effect varies between regions. This research evaluates whether variables derived from remotely sensed snow cover can be used to estimate annual streamflow at the small watershed scale across the western U.S., a region with a wide range of climate types. We compared snow cover variables derived from MODIS, snow persistence (SP), and snow season (SS), to more commonly utilized metrics, snow fraction (fraction of precipitation falling as snow, SF), and peak snow water equivalent (SWE). Each variable represents different information about snow, and this comparison assesses similarities and differences between the snow metrics. Next, we evaluated how two snow variables, SP and SWE, related to annual streamflow (Q) for 119 USGS reference watersheds and examined whether these relationships varied for wet/warm (precipitation surplus) and dry/cold (precipitation deficit) watersheds. Results showed high correlations between all snow variables, but the slopes of these relationships differed between climates, with wet/warm watersheds displaying lower SF and higher SWE for the same SP. In dry/cold watersheds, both SP and SNODAS SWE correlated with Q spatially across all watersheds and over time within individual watersheds. We conclude that SP can be used to map spatial patterns of annual streamflow generation in dry/cold parts of the region. Applying this approach to the Upper Colorado River Basin demonstrates that 50% of streamflow comes from areas >3,000 masl. If the relationship between SP and Q is similar in other dry/cold regions, this approach could be used to estimate annual streamflow in ungauged basins.

Endolithic microbial life in hot and cold deserts

NASA Technical Reports Server (NTRS)

Friedmann, E. I.

1980-01-01

Endolithic microorganisms (those living inside rocks) occur in hot and cold deserts and exist under extreme environmental conditions. These conditions are discussed on a comparative basis. Quantitative estimates of biomass are comparable in hot and cold deserts. Despite the obvious differences between the hot and cold desert environment, survival strategies show some common features. These endolithic organisms are able to 'switch' rapidly their metabolic activities on and off in response to changes in the environment. Conditions in hot deserts impose a more severe environmental stress on the organisms than in the cold Antarctic desert. This is reflected in the composition of the microbial flora which in hot desert rocks consist entirely of prokaryotic microorganisms, while under cold desert conditions eukaryotes predominate.

Determination of the structure and catalytic mechanism of sorghum bicolor caffeoyl-CoA O-methyltransferase

USDA-ARS?s Scientific Manuscript database

Although cold acclimation is a key process in plants from temperate climates, the mechanisms sensing low temperature remain obscure. Here, we show that the accumulation of the organic acid fumaric acid, mediated by the cytosolic fumarase FUM2, is essential for cold acclimation of metabolism in the c...

Cold air drainage flows subsidize montane valley ecosystem productivity

Treesearch

Kimberly A. Novick; Andrew C. Oishi; Chelcy Ford Miniat

2016-01-01

In mountainous areas, cold air drainage from high to low elevations has pronounced effects on local temperature, which is a critical driver of many ecosystem processes, including carbon uptake and storage. Here, we leverage new approaches for interpreting ecosystem carbon flux observations in complex terrain to quantify the links between macro-climate...

Assessment of five cold chilling tolerance traits and GWAS mapping in rice using the USDA mini-core collection

USDA-ARS?s Scientific Manuscript database

Rice (Oryza sativa L.) is often exposed to cool or cold temperatures during spring planting in a temperate climate. A better understanding of the genetic pathways regulating this chilling tolerance will enable breeders to develop varieties with improved tolerance during the germination and young see...

Dealing with frost damage and climate change in tree fruit crops

USDA-ARS?s Scientific Manuscript database

Each year, the U.S. produces about 15 million tons of deciduous fruit crops that have a combined value of >$10 billion. Unpredictable cold damage to these nutritionally important crops is a major threat to industry profitability. Over the last six years, cold damage has accounted for almost half o...

Palynological tracers of eustatic and climatic changes in the Late Ordovician on the North Gondwanan Margin

NASA Astrophysics Data System (ADS)

Le Hérissé, A.; Vecoli, M.

2003-04-01

The short-lived Hirnantian glacio-eustatic interval (1 My or less) caused about 60 per cent loss of total marine animal genera. This icehouse climate is also responsible for significant changes on the evolution of the plankton and the distribution of related microfossil assemblages, from pre-glacial to post-glacial episodes. This is clearly confirmed on different upper Ordovician sections from various paleogeographic location on the North Gondwanan margin. The effects of the glaciation did not correspond exactly to a cataclysmic event, because the palynomorphs do not show accelerated rates of extinction, in the inhospitable environment. It could also be noted that the origins of the Silurian communities are rooted in the upper Ordovician prior to the glaciation, with appearance of precursors (or -ahead of time-) forms, that diversified later in the Silurian. Nevertheless, the harsh climatic conditions associated to sea-level drop, caused a reduction in the number of taxa, with a scenario composed of three separate critical events: 1. a selective survival of ubiquitous taxa which are tolerant to the sea-level drawdown and of few taxa that appear specifically adapted to cold environments (Rawtheyan-early Hirnantian); 2. an adaptation of the sympagic microflora, to the variations of the sea-ice cover during deglaciation, including polymorphism and speciations (Hirnantian); 3. a slow recovery acompanying the climatic restoration and transgression in the latest Ordovician and early Silurian. Modifications in abundance and diversity of the microfossil assemblages, in the percentages of reworked elements and of amorphic organic matter are interpreted as evidence of a series of advances and retreats of the continental ice, of important changes of sea-surface conditions, of differences in the rate of melting of the icebergs during the deglaciation, as well as post-glacial isostatic rebounds. Our investigation demonstrates that the analysis of the evolution of palynomorph groups and phytoplanctonic responses to varying palaeoenvironmental conditions (as for more recent analogues) has important applications to the study of climatic changes, the deglaciation history and the sedimentary environment of the late Ordovician in a broader context.

What Is a Mild Winter? Regional Differences in Within-Species Responses to Climate Change.

PubMed

Vetter, Sebastian G; Ruf, Thomas; Bieber, Claudia; Arnold, Walter

2015-01-01

Climate change is known to affect ecosystems globally, but our knowledge of its impact on large and widespread mammals, and possibly population-specific responses is still sparse. We investigated large-scale and long-term effects of climate change on local population dynamics using the wild boar (Sus scrofa L.) as a model species. Our results show that population increases across Europe are strongly associated with increasingly mild winters, yet with region-specific threshold temperatures for the onset of exponential growth. Additionally, we found that abundant availability of critical food resources, e.g. beech nuts, can outweigh the negative effects of cold winters on population growth of wild boar. Availability of beech nuts is highly variable and highest in years of beech mast which increased in frequency since 1980, according to our data. We conclude that climate change drives population growth of wild boar directly by relaxing the negative effect of cold winters on survival and reproduction, and indirectly by increasing food availability. However, region-specific responses need to be considered in order to fully understand a species' demographic response to climate change.

Integrating physiological threshold experiments with climate modeling to project mangrove species' range expansion.

PubMed

Cavanaugh, Kyle C; Parker, John D; Cook-Patton, Susan C; Feller, Ilka C; Williams, A Park; Kellner, James R

2015-05-01

Predictions of climate-related shifts in species ranges have largely been based on correlative models. Due to limitations of these models, there is a need for more integration of experimental approaches when studying impacts of climate change on species distributions. Here, we used controlled experiments to identify physiological thresholds that control poleward range limits of three species of mangroves found in North America. We found that all three species exhibited a threshold response to extreme cold, but freeze tolerance thresholds varied among species. From these experiments, we developed a climate metric, freeze degree days (FDD), which incorporates both the intensity and the frequency of freezes. When included in distribution models, FDD accurately predicted mangrove presence/absence. Using 28 years of satellite imagery, we linked FDD to observed changes in mangrove abundance in Florida, further exemplifying the importance of extreme cold. We then used downscaled climate projections of FDD to project that these range limits will move northward by 2.2-3.2 km yr(-1) over the next 50 years. © 2014 John Wiley & Sons Ltd.

Punctuated Holocene climate of Vestfirðir, Iceland, linked to internal/external variables and oceanographic conditions

NASA Astrophysics Data System (ADS)

Harning, David J.; Geirsdóttir, Áslaug; Miller, Gifford H.

2018-06-01

Emerging Holocene paleoclimate datasets point to a non-linear response of Icelandic climate against a background of steady orbital cooling. The Vestfirðir peninsula (NW Iceland) is an ideal target for continued climate reconstructions due to the presence of a small ice cap (Drangajökull) and numerous lakes, which provide two independent means to evaluate existing Icelandic climate records and to constrain the forcing mechanisms behind centennial-scale cold anomalies. Here, we present new evidence for Holocene expansions of Drangajökull based on 14C dates from entombed dead vegetation as well as two continuous Holocene lake sediment records. Lake sediments were analyzed for both bulk physical (MS) and biological (%TOC, δ13C, C/N, and BSi) parameters. Composite BSi and C/N records from the two lakes yield a sub-centennial qualitative perspective on algal (diatom) productivity and terrestrial landscape stability, respectively. The Vestfirðir lake proxies suggest initiation of the Holocene Thermal Maximum by ∼8.8 ka with subsequent and pronounced cooling not apparent until ∼3 ka. Synchronous periods of reduced algal productivity and accelerated landscape instability point to cold anomalies centered at ∼8.2, 6.6, 4.2, 3.3, 2.3, 1.8, 1, and 0.25 ka. Triggers for cold anomalies are linked to variable combinations of freshwater pulses, low total solar irradiance, explosive and effusive volcanism, and internal modes of climate variability, with cooling likely sustained by ocean/sea-ice feedbacks. The climate evolution reflected by our glacial and organic proxy records corresponds closely to marine records from the North Iceland Shelf.

Predicted effects of climate warming on the distribution of 50 stream fishes in Wisconsin, U.S.A.

USGS Publications Warehouse

Lyons, J.; Stewart, J.S.; Mitro, M.

2010-01-01

Summer air and stream water temperatures are expected to rise in the state of Wisconsin, U.S.A., over the next 50 years. To assess potential climate warming effects on stream fishes, predictive models were developed for 50 common fish species using classification-tree analysis of 69 environmental variables in a geographic information system. Model accuracy was 56.0-93.5% in validation tests. Models were applied to all 86 898 km of stream in the state under four different climate scenarios: current conditions, limited climate warming (summer air temperatures increase 1?? C and water 0.8?? C), moderate warming (air 3?? C and water 2.4?? C) and major warming (air 5?? C and water 4?? C). With climate warming, 23 fishes were predicted to decline in distribution (three to extirpation under the major warming scenario), 23 to increase and four to have no change. Overall, declining species lost substantially more stream length than increasing species gained. All three cold-water and 16 cool-water fishes and four of 31 warm-water fishes were predicted to decline, four warm-water fishes to remain the same and 23 warm-water fishes to increase in distribution. Species changes were predicted to be most dramatic in small streams in northern Wisconsin that currently have cold to cool summer water temperatures and are dominated by cold-water and cool-water fishes, and least in larger and warmer streams and rivers in southern Wisconsin that are currently dominated by warm-water fishes. Results of this study suggest that even small increases in summer air and water temperatures owing to climate warming will have major effects on the distribution of stream fishes in Wisconsin. ?? 2010 The Authors. Journal of Fish Biology ?? 2010 The Fisheries Society of the British Isles.

Linking Teleconnections and Iowa's Climate

NASA Astrophysics Data System (ADS)

Rowe, S. T.; Villarini, G.; Lavers, D. A.; Scoccimarro, E.

2013-12-01

In recent years Iowa and the U.S. Midwest has experienced both extreme drought and flood periods. With a drought in 2012 bounded by major floods in 2011 and 2013, the rapid progression from one extreme to the next is on the forefront of the public mind. Given that Iowa is a major agricultural state, extreme weather conditions can have severe socioeconomic consequences. In this research we investigate the large-scale climate processes that occurred concurrently and before a range of dry/wet and cold/hot periods to improve process understanding of these events. It is essential to understand the large-scale climate processes, as these can then provide valuable insight toward the development of long-term climate forecasts for Iowa. In this study monthly and seasonal surface temperature and precipitation over 1950-2012 across Iowa are used. Precipitation and surface temperature data are retrieved from the Parameter-elevation Regressions on Independent Slopes Model (PRISM) Climate Group at Oregon State University. The large-scale atmospheric fields are obtained from the National Center for Environmental Prediction (NCEP) / National Center for Atmospheric Research (NCAR) Reanalysis 1 Project. Precipitation is stratified according to wet, normal, and dry conditions, while temperature according to hot, average, and cold periods. Different stratification criteria based on the precipitation and temperature distributions are examined. Mean sea-level pressure and sea-surface temperature composite maps for the northern hemisphere are then produced for the wet/dry conditions, and cold/hot conditions. Further analyses include correlation, anomalies, and assessment of large-scale planetary wave activity, shedding light on the differences and similarities among the opposite weather conditions. The results of this work will highlight regional weather patterns that are related to the climate over Iowa, providing valuable insight into the mechanisms controlling the occurrence of potentially extreme weather conditions over this area.

Predicted effects of climate warming on the distribution of 50 stream fishes in Wisconsin, U.S.A.

USGS Publications Warehouse

Stewart, Jana S.; Lyons, John D.; Matt Mitro,

2010-01-01

Summer air and stream water temperatures are expected to rise in the state of Wisconsin, U.S.A., over the next 50 years. To assess potential climate warming effects on stream fishes, predictive models were developed for 50 common fish species using classification-tree analysis of 69 environmental variables in a geographic information system. Model accuracy was 56·0–93·5% in validation tests. Models were applied to all 86 898 km of stream in the state under four different climate scenarios: current conditions, limited climate warming (summer air temperatures increase 1° C and water 0·8° C), moderate warming (air 3° C and water 2·4° C) and major warming (air 5° C and water 4° C). With climate warming, 23 fishes were predicted to decline in distribution (three to extirpation under the major warming scenario), 23 to increase and four to have no change. Overall, declining species lost substantially more stream length than increasing species gained. All three cold-water and 16 cool-water fishes and four of 31 warm-water fishes were predicted to decline, four warm-water fishes to remain the same and 23 warm-water fishes to increase in distribution. Species changes were predicted to be most dramatic in small streams in northern Wisconsin that currently have cold to cool summer water temperatures and are dominated by cold-water and cool-water fishes, and least in larger and warmer streams and rivers in southern Wisconsin that are currently dominated by warm-water fishes. Results of this study suggest that even small increases in summer air and water temperatures owing to climate warming will have major effects on the distribution of stream fishes in Wisconsin.

40 CFR 1066.710 - Cold temperature testing procedures for measuring CO and NMHC emissions and determining fuel...

Code of Federal Regulations, 2014 CFR

2014-07-01

... climate control system with the heat on and set to primarily defrost the front window. Turn air.... (i) Prior to the first acceleration, 20 seconds after the start of the UDDS, set the climate control... climate control system): (A) Temperature. Set controls to maximum heat. (B) Fan speed. Set the fan speed...

Incorporating climate change into pest risk models for forest pathogens: a role for cold stress in an era of global warming?

Treesearch

Robert C. Venette

2013-01-01

Climate change may alter the distribution and activity of native and alien pathogens that infect trees and, in severe cases, cause tree death. In this study, potential future changes in climate suitability are investigated for three forest pathogens that occur in western North America: the native Arceuthobium tsugense subsp tsugense...

Slow climate velocities of mountain streams portend their role as refugia for cold-water biodiversity

Treesearch

Daniel J. Isaak; Michael K. Young; Charlie Luce; Steven W. Hostetler; Seth J. Wenger; Erin E. Peterson; Jay M. Ver Hoef; Matthew C. Groce; Dona L. Horan; David E. Nagel

2016-01-01

The imminent demise of montane species is a recurrent theme in the climate change literature, particularly for aquatic species that are constrained to networks and elevational rather than latitudinal retreat as temperatures increase. Predictions of widespread species losses, however, have yet to be fulfilled despite decades of climate change, suggesting that trends are...

Attributing Changing Rates of Temperature Record Breaking to Anthropogenic Influences

NASA Astrophysics Data System (ADS)

King, Andrew D.

2017-11-01

Record-breaking temperatures attract attention from the media, so understanding how and why the rate of record breaking is changing may be useful in communicating the effects of climate change. A simple methodology designed for estimating the anthropogenic influence on rates of record breaking in a given time series is proposed here. The frequency of hot and cold record-breaking temperature occurrences is shown to be changing due to the anthropogenic influence on the climate. Using ensembles of model simulations with and without human-induced forcings, it is demonstrated that the effect of climate change on global record-breaking temperatures can be detected as far back as the 1930s. On local scales, a climate change signal is detected more recently at most locations. The anthropogenic influence on the increased occurrence of hot record-breaking temperatures is clearer than it is for the decreased occurrence of cold records. The approach proposed here could be applied in rapid attribution studies of record extremes to quantify the influence of climate change on the rate of record breaking in addition to the climate anomaly being studied. This application is demonstrated for the global temperature record of 2016 and the Central England temperature record in 2014.

Evolutionary divergence of mitochondrial genomes in two Tetranychus species distributed across different climates.

PubMed

Sun, J-T; Jin, P-Y; Hoffmann, A A; Duan, X-Z; Dai, J; Hu, G; Xue, X-F; Hong, X-Y

2018-05-24

There is increasing evidence that mitochondrial genomes (mitogenomes) can be under selection, whereas the selective regimes shaping mitogenome evolution remain largely unclear. To test for mitochondrial genome evolution in relation to the climate adaptation, we explored mtDNA variation in two spider mite (Tetranychus) species, which distribute across different climates. We sequenced 26 complete mitogenomes of T. truncatus which occurs in both warm and cold regions, and 9 complete mitogenomes of T. pueraricola which is only restricted in warm regions. Patterns of evolution in the two species mitogenomes were compared through a series of d N /d S methods and physicochemical profiles of amino acid replacements. We found that (1) the mitogenomes of both species were under widespread purifying selection. (2) Elevated directional adaptive selection was observed in the T. truncatus mitogenome, perhaps linked to the cold climates adaptation of T. truncatus. (3) The strength of selection varied across genes, and diversifying positive selection detected on ND4 and ATP6 pointed to their crucial roles during adaptation to different climatic conditions. This study gained insight into the mitogenome evolution in relation to the climate adaptation. This article is protected by copyright. All rights reserved. © 2018 The Royal Entomological Society.

Optimization for energy efficiency of underground building envelope thermal performance in different climate zones of China

NASA Astrophysics Data System (ADS)

Shi, Luyang; Liu, Jing; Zhang, Huibo

2017-11-01

The object of this article is to investigate the influence of thermal performance of envelopes in shallow-buried buildings on energy consumption for different climate zones of China. For the purpose of this study, an effective building energy simulation tool (DeST) developed by Tsinghua University was chosen to model the heat transfer in underground buildings. Based on the simulative results, energy consumption for heating and cooling for the whole year was obtained. The results showed that the relationship between energy consumption and U-value of envelopes for underground buildings is different compared with above-ground buildings: improving thermal performance of exterior walls cannot reduce energy consumption, on the contrary, may result in more energy cost. Besides, it is can be derived that optimized U-values of underground building envelopes vary with climate zones of China in this study. For severe cold climate zone, the optimized U-value of underground building envelopes is 0.8W/(m2·K); for cold climate zone, the optimized U-value is 1.5W/(m2·K); for warm climate zone, the U-value is 2.0W/(m2·K).

Behavioural adaptations of Rana temporaria to cold climates.

PubMed

Ludwig, Gerda; Sinsch, Ulrich; Pelster, Bernd

2015-01-01

Environmental conditions at the edge of a species' ecological optimum can exert great ecological or evolutionary pressure at local populations. For ectotherms like amphibians temperature is one of the most important abiotic factors of their environment as it influences directly their metabolism and sets limits to their distribution. Amphibians have evolved three ways to cope with sub-zero temperatures: freeze tolerance, freeze protection, freeze avoidance. The aim of this study was to assess which strategy common frogs at mid and high elevation use to survive and thrive in cold climates. In particular we (1) tested for the presence of physiological freeze protection, (2) evaluated autumnal activity and overwintering behaviour with respect to freeze avoidance and (3) assessed the importance of different high-elevation microhabitats for behavioural thermoregulation. Common frogs did not exhibit any signs of freeze protection when experiencing temperatures around 0 °C. Instead they retreated to open water for protection and overwintering. High elevation common frogs remained active for around the same period of time than their conspecifics at lower elevation. Our results suggest that at mid and high elevation common frogs use freeze avoidance alone to survive temperatures below 0 °C. The availability of warm microhabitats, such as rock or pasture, provides high elevation frogs with the opportunity of behavioural thermoregulation and thus allows them to remain active at temperatures at which common frogs at lower elevation cease activity. Copyright © 2015 Elsevier Ltd. All rights reserved.

Cardiovascular response to thermoregulatory challenges

PubMed Central

Liu, Cuiqing; Yavar, Zubin

2015-01-01

A growing number of extreme climate events are occurring in the setting of ongoing climate change, with an increase in both the intensity and frequency. It has been shown that ambient temperature challenges have a direct and highly varied impact on cardiovascular health. With a rapidly growing amount of literature on this issue, we aim to review the recent publications regarding the impact of cold and heat on human populations with regard to cardiovascular disease (CVD) mortality/morbidity while also examining lag effects, vulnerable subgroups, and relevant mechanisms. Although the relative risk of morbidity/mortality associated with extreme temperature varied greatly across different studies, both cold and hot temperatures were associated with a positive mean excess of cardiovascular deaths or hospital admissions. Cause-specific study of CVD morbidity/mortality indicated that the sensitivity to temperature was disease-specific, with different patterns for acute and chronic ischemic heart disease. Vulnerability to temperature-related mortality was associated with some characteristics of the populations, including sex, age, location, socioeconomic condition, and comorbidities such as cardiac diseases, kidney diseases, diabetes, and hypertension. Temperature-induced damage is thought to be related to enhanced sympathetic reactivity followed by activation of the sympathetic nervous system, renin-angiotensin system, as well as dehydration and a systemic inflammatory response. Future research should focus on multidisciplinary adaptation strategies that incorporate epidemiology, climatology, indoor/building environments, energy usage, labor legislative perfection, and human thermal comfort models. Studies on the underlying mechanism by which temperature challenge induces pathophysiological response and CVD await profound and lasting investigation. PMID:26432837

Geomorphic Map of Worcester County, Maryland, Interpreted from a LIDAR-Based, Digital Elevation Model

USGS Publications Warehouse

Newell, Wayne L.; Clark, Inga

2008-01-01

A recently compiled mosaic of a LIDAR-based digital elevation model (DEM) is presented with geomorphic analysis of new macro-topographic details. The geologic framework of the surficial and near surface late Cenozoic deposits of the central uplands, Pocomoke River valley, and the Atlantic Coast includes Cenozoic to recent sediments from fluvial, estuarine, and littoral depositional environments. Extensive Pleistocene (cold climate) sandy dune fields are deposited over much of the terraced landscape. The macro details from the LIDAR image reveal 2 meter-scale resolution of details of the shapes of individual dunes, and fields of translocated sand sheets. Most terrace surfaces are overprinted with circular to elliptical rimmed basins that represent complex histories of ephemeral ponds that were formed, drained, and overprinted by younger basins. The terrains of composite ephemeral ponds and the dune fields are inter-shingled at their margins indicating contemporaneous erosion, deposition, and re-arrangement and possible internal deformation of the surficial deposits. The aggregate of these landform details and their deposits are interpreted as the products of arid, cold climate processes that were common to the mid-Atlantic region during the Last Glacial Maximum. In the Pocomoke valley and its larger tributaries, erosional remnants of sandy flood plains with anastomosing channels indicate the dynamics of former hydrology and sediment load of the watershed that prevailed at the end of the Pleistocene. As the climate warmed and precipitation increased during the transition from late Pleistocene to Holocene, dune fields were stabilized by vegetation, and the stream discharge increased. The increased discharge and greater local relief of streams graded to lower sea levels stimulated down cutting and created the deeply incised valleys out onto the continental shelf. These incised valleys have been filling with fluvial to intertidal deposits that record the rising sea level and warmer, more humid climate in the mid-Atlantic region throughout the Holocene. Thus, the geomorphic details provided by the new LIDAR DEM actually record the response of the landscape to abrupt climate change. Holocene trends and land-use patterns from Colonial to modern times can also be interpreted from the local macro- scale details of the landscape. Beyond the obvious utility of these data for land-use planning and assessments of resources and hazards, the new map presents new details on the impact of climate changes on a mid-latitude, outer Coastal plain landscape.

Global Warming and Its Health Impact.

PubMed

Rossati, Antonella

2017-01-01

Since the mid-19th century, human activities have increased greenhouse gases such as carbon dioxide, methane, and nitrous oxide in the Earth's atmosphere that resulted in increased average temperature. The effects of rising temperature include soil degradation, loss of productivity of agricultural land, desertification, loss of biodiversity, degradation of ecosystems, reduced fresh-water resources, acidification of the oceans, and the disruption and depletion of stratospheric ozone. All these have an impact on human health, causing non-communicable diseases such as injuries during natural disasters, malnutrition during famine, and increased mortality during heat waves due to complications in chronically ill patients. Direct exposure to natural disasters has also an impact on mental health and, although too complex to be quantified, a link has even been established between climate and civil violence. Over time, climate change can reduce agricultural resources through reduced availability of water, alterations and shrinking arable land, increased pollution, accumulation of toxic substances in the food chain, and creation of habitats suitable to the transmission of human and animal pathogens. People living in low-income countries are particularly vulnerable. Climate change scenarios include a change in distribution of infectious diseases with warming and changes in outbreaks associated with weather extreme events. After floods, increased cases of leptospirosis, campylobacter infections and cryptosporidiosis are reported. Global warming affects water heating, rising the transmission of water-borne pathogens. Pathogens transmitted by vectors are particularly sensitive to climate change because they spend a good part of their life cycle in a cold-blooded host invertebrate whose temperature is similar to the environment. A warmer climate presents more favorable conditions for the survival and the completion of the life cycle of the vector, going as far as to speed it up as in the case of mosquitoes. Diseases transmitted by mosquitoes include some of the most widespread worldwide illnesses such as malaria and viral diseases. Tick-borne diseases have increased in the past years in cold regions, because rising temperatures accelerate the cycle of development, the production of eggs, and the density and distribution of the tick population. The areas of presence of ticks and diseases that they can transmit have increased, both in terms of geographical extension than in altitude. In the next years the engagement of the health sector would be working to develop prevention and adaptation programs in order to reduce the costs and burden of climate change.

Residential Cold Climate Heat Pump (CCHP) w/Variable Speed Technology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Messmer, Craig S.

2016-09-30

This report summarizes the results of a three year program awarded to Unico, Inc. to commercialize a residential cold climate heat pump. Several designs were investigated. Compressors were selected using analysis from Oakridge National Laboratories followed by prototype construction and lab testing in a specially built environmental chamber capable of reaching -30°F. The initial design utilized two variable speed compressors in series with very good capacity results and acceptable efficiency at very cold temperatures. The design was then modified to reduce cost and complexity by redesigning the system using three dual-stage compressors: two in parallel followed by one in series.more » Extensive testing found significant challenge with oil management, reliability, weight and cost which prevented the system from being fully commercialized. Further analysis of other conceptual designs indicated that these challenges could be overcome in the future.« less

Cold acclimation and cognitive performance: A review.

PubMed

Jones, Douglas M; Bailey, Stephen P; Roelands, Bart; Buono, Michael J; Meeusen, Romain

2017-12-01

Athletes, occupational workers, and military personnel experience cold temperatures through cold air exposure or cold water immersion, both of which impair cognitive performance. Prior work has shown that neurophysiological pathways may be sensitive to the effects of temperature acclimation and, therefore, cold acclimation may be a potential strategy to attenuate cold-induced cognitive impairments for populations that are frequently exposed to cold environments. This review provides an overview of studies that examine repeated cold stress, cold acclimation, and measurements of cognitive performance to determine whether or not cold acclimation provides beneficial protection against cold-induced cognitive performance decrements. Studies included in this review assessed cognitive measures of reaction time, attention, logical reasoning, information processing, and memory. Repeated cold stress, with or without evidence of cold acclimation, appears to offer no added benefit of improving cognitive performance. However, research in this area is greatly lacking and, therefore, it is difficult to draw any definitive conclusions regarding the use of cold acclimation to improve cognitive performance during subsequent cold exposures. Given the current state of minimal knowledge on this topic, athletes, occupational workers, and military commands looking to specifically enhance cognitive performance in cold environments would likely not be advised to spend the time and effort required to become acclimated to cold. However, as more knowledge becomes available in this area, recommendations may change. Copyright © 2017 Elsevier B.V. All rights reserved.

Characterizing convective cold pools: Characterizing Convective Cold Pools

DOE PAGES

Drager, Aryeh J.; van den Heever, Susan C.

2017-05-09

Cold pools produced by convective storms play an important role in Earth's climate system. However, a common framework does not exist for objectively identifying convective cold pools in observations and models. The present study investigates convective cold pools within a simulation of tropical continental convection that uses a cloud-resolving model with a coupled land-surface model. Multiple variables are assessed for their potential in identifying convective cold pool boundaries, and a novel technique is developed and tested for identifying and tracking cold pools in numerical model simulations. This algorithm is based on surface rainfall rates and radial gradients in the densitymore » potential temperature field. The algorithm successfully identifies near-surface cold pool boundaries and is able to distinguish between connected cold pools. Once cold pools have been identified and tracked, composites of cold pool evolution are then constructed, and average cold pool properties are investigated. Wet patches are found to develop within the centers of cold pools where the ground has been soaked with rainwater. These wet patches help to maintain cool surface temperatures and reduce cold pool dissipation, which has implications for the development of subsequent convection.« less

Characterizing convective cold pools: Characterizing Convective Cold Pools

DOE Office of Scientific and Technical Information (OSTI.GOV)

Drager, Aryeh J.; van den Heever, Susan C.

Cold pools produced by convective storms play an important role in Earth's climate system. However, a common framework does not exist for objectively identifying convective cold pools in observations and models. The present study investigates convective cold pools within a simulation of tropical continental convection that uses a cloud-resolving model with a coupled land-surface model. Multiple variables are assessed for their potential in identifying convective cold pool boundaries, and a novel technique is developed and tested for identifying and tracking cold pools in numerical model simulations. This algorithm is based on surface rainfall rates and radial gradients in the densitymore » potential temperature field. The algorithm successfully identifies near-surface cold pool boundaries and is able to distinguish between connected cold pools. Once cold pools have been identified and tracked, composites of cold pool evolution are then constructed, and average cold pool properties are investigated. Wet patches are found to develop within the centers of cold pools where the ground has been soaked with rainwater. These wet patches help to maintain cool surface temperatures and reduce cold pool dissipation, which has implications for the development of subsequent convection.« less

Thermokarst transformation of permafrost preserved glaciated landscapes.

NASA Astrophysics Data System (ADS)

Kokelj, S.; Tunnicliffe, J. F.; Fraser, R.; Kokoszka, J.; Lacelle, D.; Lantz, T. C.; Lamoureux, S. F.; Rudy, A.; Shakil, S.; Tank, S. E.; van der Sluijs, J.; Wolfe, S.; Zolkos, S.

2017-12-01

Thermokarst is the fundamental mechanism of landscape change and a primary driver of downstream effects in a warming circumpolar world. Permafrost degradation is inherently non-linear because latent heat effects can inhibit thawing. However, once this thermal transition is crossed thermokarst can accelerate due to the interaction of thermal, physical and ecological feedbacks. In this paper we highlight recent climate and precipitation-driven intensification of thaw slumping that is transforming permafrost preserved glaciated landscapes in northwestern Canada. The continental distribution of slump affected terrain reflects glacial extents and recessional positions of the Laurentide Ice sheet. On this basis and in conjunction with intense thermokarst in cold polar environments, we highlight the critical roles of geological legacy and climate history in dictating the sensitivity of permafrost terrain. These glaciated landscapes, maintained in a quasi-stable state throughout much of the late Holocene are now being transformed into remarkably dynamic environments by climate-driven thermokarst. Individual disturbances displace millions of cubic metres of previously frozen material downslope, converting upland sedimentary stores into major source areas. Precipitation-driven evacuation of sediment by fluidized mass flows perpetuates non-linear enlargement of disturbances. The infilling of valleys with debris deposits tens of metres thick increases stream base-levels and promotes rapid valley-side erosion. These processes destabilize adjacent slopes and proliferate disturbance effects. Physically-based modeling of thaw slump development provides insight into the trajectories of landscape change, and the mapping of fluvial linkages portrays the cascade of effects across watershed scales. Post-glacial or "paraglacial" models of landscape evolution provide a useful framework for understanding the nature and magnitude of climate-driven changes in permafrost preserved glaciated landscapes.

The effect of time of day on cold water ingestion by high-level swimmers in a tropical climate.

PubMed

Hue, Olivier; Monjo, Roland; Lazzaro, Marc; Baillot, Michelle; Hellard, Philippe; Marlin, Laurent; Jean-Etienne, A

2013-07-01

The authors tested the effect of cold water ingestion during high-intensity training in the morning vs the evening on both core temperature (TC) and thermal perceptions of internationally ranked long-distance swimmers during a training period in a tropical climate. Nine internationally ranked long-distance swimmers (5 men and 4 women) performed 4 randomized training sessions (2 in the evening and 2 in the morning) with 2 randomized beverages with different temperatures for 3 consecutive days. After a standardized warm-up of 1000 m, the subjects performed a standardized training session that consisted of 10 x 100 m (start every 1'20″) at a fixed velocity. The swimmers were then followed for the next 3000 m of the training schedule. Heart rate (HR) was continuously monitored during the 10 x 100 m, whereas TC, thermal comfort, and thermal sensation (TS) were measured before and after each 1000-m session. Before and after each 1000 m, the swimmers were asked to drink 190 mL of neutral (26.5 ± 2.5°C) or cold (1.3 ± 0.3°C) water packaged in standardized bottles. Results demonstrated that cold water ingestion induced a significant effect on TC, with a pronounced decrease in the evening, resulting in significantly lower mean TC and lower mean delta TC in evening cold (EC) than in evening neutral (EN), concomitant with significantly lower TS in EC than in EN and a significant effect on exercise HR. Moreover, although TC increased significantly with time in MN, MC, and EN, TC was stabilized during exercise in EC. To conclude, we demonstrate that a cold beverage had a significant effect on TC, TS, and HR during training in high-level swimmers in a tropical climate, especially during evening training.

Cold air drainage flows subsidize montane valley ecosystem productivity.

PubMed

Novick, Kimberly A; Oishi, A Christopher; Miniat, Chelcy Ford

2016-12-01

In mountainous areas, cold air drainage from high to low elevations has pronounced effects on local temperature, which is a critical driver of many ecosystem processes, including carbon uptake and storage. Here, we leverage new approaches for interpreting ecosystem carbon flux observations in complex terrain to quantify the links between macro-climate condition, drainage flows, local microclimate, and ecosystem carbon cycling in a southern Appalachian valley. Data from multiple long-running climate stations and multiple eddy covariance flux towers are combined with simple models for ecosystem carbon fluxes. We show that cold air drainage into the valley suppresses local temperature by several degrees at night and for several hours before and after sunset, leading to reductions in growing season respiration on the order of ~8%. As a result, we estimate that drainage flows increase growing season and annual net carbon uptake in the valley by >10% and >15%, respectively, via effects on microclimate that are not be adequately represented in regional- and global-scale terrestrial ecosystem models. Analyses driven by chamber-based estimates of soil and plant respiration reveal cold air drainage effects on ecosystem respiration are dominated by reductions to the respiration of aboveground biomass. We further show that cold air drainage proceeds more readily when cloud cover and humidity are low, resulting in the greatest enhancements to net carbon uptake in the valley under clear, cloud-free (i.e., drought-like) conditions. This is a counterintuitive result that is neither observed nor predicted outside of the valley, where nocturnal temperature and respiration increase during dry periods. This result should motivate efforts to explore how topographic flows may buffer eco-physiological processes from macroscale climate change. © 2016 John Wiley & Sons Ltd.

Understanding the effect of an excessive cold tongue bias on projecting the tropical Pacific SST warming pattern in CMIP5 models

NASA Astrophysics Data System (ADS)

Ying, Jun; Huang, Ping; Lian, Tao; Tan, Hongjian

2018-05-01

An excessive cold tongue is a common bias among current climate models, and considered an important source of bias in projections of tropical Pacific climate change under global warming. Specifically, the excessive cold tongue bias is closely related to the tropical Pacific SST warming (TPSW) pattern. In this study, we reveal that two processes are the critical mechanisms by which the excessive cold tongue bias influences the projection of the TPSW pattern, based on 32 models from phase 5 of Coupled Model Intercomparison Projection (CMIP5). On the one hand, by assuming that the shortwave (SW) radiation to SST feedback is linearly correlated to the cold tongue SST, the excessive cold tongue bias can induce an overly weak negative SW-SST feedback in the central Pacific, which can lead to a positive SST warming bias in the central to western Pacific (around 150°E-140°W). Moreover, the overly weak local atmospheric dynamics response to SST is a key process of the overly weak SW-SST feedback, compared with the cloud response to atmospheric dynamics and the SW radiation response to cloud. On the other hand, the overly strong ocean zonal overturning circulation associated with the excessive cold tongue bias results in an overestimation of the ocean dynamical thermostat effect, with enhanced ocean stratification under global warming, leading to a negative SST warming bias in the central and eastern Pacific (around 170°W-120°W). These two processes jointly form a positive SST warming bias in the western Pacific, contributing to a La Niña-like warming bias. Therefore, we suggest a more realistic climatological cold tongue SST is needed for a more reliable projection of the TPSW pattern.

Weather, Climate, and You.

ERIC Educational Resources Information Center

Blai, Boris, Jr.

Information from the American Institute of Medical Climatologists on human responses to weather and climatic conditions, including clouds, winds, humidity, barometric pressure, heat, cold, and other variables that may exert a pervasive impact on health, behavior, disposition, and the level of efficiency with which individuals function is reviewed.…

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

PubMed

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

2015-02-01

Winter is a key driver of individual performance, community composition, and ecological interactions in terrestrial habitats. Although climate change research tends to focus on performance in the growing season, climate change is also modifying winter conditions rapidly. Changes to winter temperatures, the variability of winter conditions, and winter snow cover can interact to induce cold injury, alter energy and water balance, advance or retard phenology, and modify community interactions. Species vary in their susceptibility to these winter drivers, hampering efforts to predict biological responses to climate change. Existing frameworks for predicting the impacts of climate change do not incorporate the complexity of organismal responses to winter. Here, we synthesise organismal responses to winter climate change, and use this synthesis to build a framework to predict exposure and sensitivity to negative impacts. This framework can be used to estimate the vulnerability of species to winter climate change. We describe the importance of relationships between winter conditions and performance during the growing season in determining fitness, and demonstrate how summer and winter processes are linked. Incorporating winter into current models will require concerted effort from theoreticians and empiricists, and the expansion of current growing-season studies to incorporate winter. © 2014 The Authors. Biological Reviews © 2014 Cambridge Philosophical Society.

Health Impacts of Climate Change-Induced Subzero Temperature Fires.

PubMed

Metallinou, Maria-Monika; Log, Torgrim

2017-07-20

General fire risk and the special risk related to cold climate cellulosic drying processes are outlined. Four recent subzero temperatures fires are studied with respect to health impacts: a wooden village fire, a single wood structure fire, a wildland urban interface (WUI) fire and a huge wildland fire. The health impacts range from stress related to loss of jobs, psychological effects of lost possessions, exposure to smoke and heat as well as immediate, or delayed, loss of lives. These four fires resulted in 32 fatalities, 385 persons hospitalized for shorter or longer periods, 104 structures lost and 1015 km² of wildland burned north of, and just south of, the Arctic Circle. It is shown that the combination of subzero temperature dry weather, strong winds, changing agricultural activities and declining snowpack may lead to previously anticipated threats to people and the environment. There are reasons to believe that these fires are a result of the ongoing climate changes. Risk impacts are discussed. Rural districts and/or vulnerable populations seem to be most affected. Training methods to identify and better monitor critical fire risk parameters are suggested to mitigate the health impacts of a possibly increasing number of such fires.

Health Impacts of Climate Change-Induced Subzero Temperature Fires

PubMed Central

Metallinou, Maria-Monika; Log, Torgrim

2017-01-01

General fire risk and the special risk related to cold climate cellulosic drying processes are outlined. Four recent subzero temperatures fires are studied with respect to health impacts: a wooden village fire, a single wood structure fire, a wildland urban interface (WUI) fire and a huge wildland fire. The health impacts range from stress related to loss of jobs, psychological effects of lost possessions, exposure to smoke and heat as well as immediate, or delayed, loss of lives. These four fires resulted in 32 fatalities, 385 persons hospitalized for shorter or longer periods, 104 structures lost and 1015 km2 of wildland burned north of, and just south of, the Arctic Circle. It is shown that the combination of subzero temperature dry weather, strong winds, changing agricultural activities and declining snowpack may lead to previously anticipated threats to people and the environment. There are reasons to believe that these fires are a result of the ongoing climate changes. Risk impacts are discussed. Rural districts and/or vulnerable populations seem to be most affected. Training methods to identify and better monitor critical fire risk parameters are suggested to mitigate the health impacts of a possibly increasing number of such fires. PMID:28726752

A simple algorithm for identifying periods of snow accumulation on a radiometer

NASA Astrophysics Data System (ADS)

Lapo, Karl E.; Hinkelman, Laura M.; Landry, Christopher C.; Massmann, Adam K.; Lundquist, Jessica D.

2015-09-01

Downwelling solar, Qsi, and longwave, Qli, irradiances at the earth's surface are the primary energy inputs for many hydrologic processes, and uncertainties in measurements of these two terms confound evaluations of estimated irradiances and negatively impact hydrologic modeling. Observations of Qsi and Qli in cold environments are subject to conditions that create additional uncertainties not encountered in other climates, specifically the accumulation of snow on uplooking radiometers. To address this issue, we present an automated method for estimating these periods of snow accumulation. Our method is based on forest interception of snow and uses common meteorological observations. In this algorithm, snow accumulation must exceed a threshold to obscure the sensor and is only removed through scouring by wind or melting. The algorithm is evaluated at two sites representing different mountain climates: (1) Snoqualmie Pass, Washington (maritime) and (2) the Senator Beck Basin Study Area, Colorado (continental). The algorithm agrees well with time-lapse camera observations at the Washington site and with multiple measurements at the Colorado site, with 70-80% of observed snow accumulation events correctly identified. We suggest using the method for quality controlling irradiance observations in snow-dominated climates where regular, daily maintenance is not possible.

Cold-water refuges for climate resilience in Oregon coastal ...

EPA Pesticide Factsheets

Many rivers and streams in the Pacific Northwest are currently listed as impaired under the Clean Water Act as a result of high summer water temperatures. Adverse effects of warm waters include impacts to salmon and steelhead populations that may already be stressed by habitat alteration, disease, predation, and fishing pressures. Thermal refuges may help mitigate the effects of increasing temperatures. In this presentation, we define cold-water refuges as areas buffered from regional climate effects by groundwater, physical habitat heterogeneity, or other watershed attributes. Processes forming these features include groundwater-surface water interactions, and hyporheic exchange at a range of spatial and temporal scales. Patterns associated with these processes may provide useful indicators for mapping and predicting the locations and extent of these features. Fish may congregate at high densities within cold-water refuges during critical periods of thermal stress, but there may be trade-offs associated with refuge use including predation, disease risk, and reduced foraging opportunities. These factors all contribute to determining refuge effectiveness. Watershed management and restoration strategies could consider these features and their potential utility to cold-water fish, and we conclude with examples of types of watershed restoration actions that might help foster cold-water refuge creation and maintenance.M Many rivers and streams in the Pacific Nort

The distribution of organic carbon fractions in a typical loess-paleosol profile and its paleoenvironmental significance

PubMed Central

Hu, Feinan; Huo, Na; Shang, Yingni; Chang, Wenqian

2018-01-01

Background The loess-paleosol sequence on the Loess Plateau has been considered an important paleoclimatic archive to study global climatic and environmental changes in the Quaternary. So far, little attention has been paid to the characteristics of soil organic carbon fractions in loess-paleosol sequences, which may provide valuable information for exploring the evolution of climate and environment in the Quaternary on the Loess Plateau. Methods In order to explore the significance of mineral-associated organic carbon to total organic carbon (MOC/TOC) ratios in the loess-paleosol sequence for reconstructing paleoenvironmental and paleoclimatic evolution in the Quaternary on the Loess Plateau, we selected a typical loess-paleosol profile in Chunhua county, Xianyang city, Shaanxi province, as the research object. The content of total organic carbon (TOC) and MOC/TOC ratio in each loess and paleosol layers of the Chunhua loess-paleosol profile were analyzed, together with the paleoclimatic proxies, such as soil grain size, CaCO3 content and their correlations with organic carbon parameters. Results The main results were as follows: (1) the total content of soil organic carbon and MOC/TOC ratios were generally higher in paleosol layers than in the underlying loess layers of the Chunhua loess-paleosol profile. Compared to total organic carbon content, MOC/TOC ratios changed more obviously in soil layers below a paleosol layer S8; (2) soil clay content and median grain size (Md (ϕ)) were higher in paleosol than in the underlying loess, while CaCO3 content showed an opposite tendency. In the Chunhua profile, the distribution characteristics of the three paleoclimatic proxies showed good indications of paleoclimate changes in the Quaternary; (3) in the Chunhua loess-paleosol profile, MOC/TOC ratios were positively correlated with clay content and median grain size (ϕ), while negatively correlated with CaCO3 content, and the correlations were more significant in soil layers below S8. Discussion Our results indicated that MOC/TOC ratios in the Chunhua loess-paleosol profile correlated with the cold dry-warm wet paleoclimatic cycle in the Quaternary. The high MOC/TOC ratios in the loess-paleosol profile might reflect warm and humid climate, while lower ratios indicated relatively cold and dry climate. That is because when the climate changed from warm-humid to cold-dry, the vegetation coverage and pedogenesis intensity decreased, which increased soil CaCO3 content and decreased soil clay content and Md (ϕ), leading to decreased MOC/TOC ratios. Compared to TOC, MOC/TOC ratios had greater significance in indicating paleoenvironmental evolution in the Quaternary on the Loess Plateau. Therefore, investigating MOC/TOC ratios in loess-paleosol profile can offer new evidence to reconstructing paleoenvironmental changes, and also provide a basis for predicting responses of soil organic carbon pools to vegetation and climate changes in the future. PMID:29666763

Mineral magnetism and other characteristics of sediments from a sub-alpine lake (3080 m a.s.l.) in central east China and their implications on environmental changes for the last 5770 years

NASA Astrophysics Data System (ADS)

Wang, Hongya; Song, Yaqiong; Cheng, Ying; Luo, Yao; Zhang, Cai'na; Gao, Yishen; Qiu, An'an; Deng, Lei; Liu, Hongyan

2016-10-01

A sediment sequence (SQC07) was recovered from Sanqing Chi, a small sub-alpine lake (3080 m a.s.l.) on Taibai (3767 m a.s.l.), the highest mountain in east mainland China (east of 105°). The Mountain is also the highest part and central massif of the Qinling Mountain Range functioning as the boundary between the warm temperate climate zone to the north and sub-tropical climate zone to the south in east China. Soils and debris were also sampled from the catchment of Sanqing Chi. SQC07 was AMS 14C dated. Mineral magnetism was measured for the sediment sequence and catchment samples. Particle-size, TOC and TN analysis were undertaken on SQC07, while pollen analysis was made for the sediment sequence and surface-soil samples. With the mineral magnetism of the catchment materials, the magnetic and other characteristics of SQC07 indicate the environmental changes occurring on the high altitudes of Taibai Mountain during the past 5770 years. Environments were still moderately warm and wet over 5770-5100 cal. yr BP around this sub-alpine lake. Then cold and dry conditions persisted in the period of 5100-4000 cal. yr BP. Local environments began to ameliorate from 4000 cal. yr BP onwards and were thus generally warm and wet over 4000-1200 cal. yr BP. The warmth and wetness culminated in 1200-800 cal. yr BP. During the period of 800-400 cal. yr BP, cold and arid conditions again predominated. Environments have subsequently become warm and humid since ∼400 cal. yr BP. The overall trend of the changes is coincident with what have been identified at several other sites in east mainland China and Taiwan. Presumably, the deterioration over 5100-4000 cal. yr BP marks the termination of the Holocene optimum, corresponds to or encompasses Holocene event 3, while the deterioration occurring in 800-400 cal. yr BP may correspond to LIA cooling. However, they appear to have commenced earlier than the aforementioned sites at relatively low altitudes in east mainland China or even higher altitudes but far southeast in Taiwan. These differences are possibly caused partly by uncertainties and/or errors of chronologies. Nevertheless, they also could be attributed to the spatial variability of East Asian monsoon and/or earlier responses of local landscapes around Sanqing Chi to larger-scale climate-deterioration.

Simulated trends of extreme climate indices for the Carpathian basin using outputs of different regional climate models

NASA Astrophysics Data System (ADS)

Pongracz, R.; Bartholy, J.; Szabo, P.; Pieczka, I.; Torma, C. S.

2009-04-01

Regional climatological effects of global warming may be recognized not only in shifts of mean temperature and precipitation, but in the frequency or intensity changes of different climate extremes. Several climate extreme indices are analyzed and compared for the Carpathian basin (located in Central/Eastern Europe) following the guidelines suggested by the joint WMO-CCl/CLIVAR Working Group on climate change detection. Our statistical trend analysis includes the evaluation of several extreme temperature and precipitation indices, e.g., the numbers of severe cold days, winter days, frost days, cold days, warm days, summer days, hot days, extremely hot days, cold nights, warm nights, the intra-annual extreme temperature range, the heat wave duration, the growing season length, the number of wet days (using several threshold values defining extremes), the maximum number of consecutive dry days, the highest 1-day precipitation amount, the greatest 5-day rainfall total, the annual fraction due to extreme precipitation events, etc. In order to evaluate the future trends (2071-2100) in the Carpathian basin, daily values of meteorological variables are obtained from the outputs of various regional climate model (RCM) experiments accomplished in the frame of the completed EU-project PRUDENCE (Prediction of Regional scenarios and Uncertainties for Defining EuropeaN Climate change risks and Effects). Horizontal resolution of the applied RCMs is 50 km. Both scenarios A2 and B2 are used to compare past and future trends of the extreme climate indices for the Carpathian basin. Furthermore, fine-resolution climate experiments of two additional RCMs adapted and run at the Department of Meteorology, Eotvos Lorand University are used to extend the trend analysis of climate extremes for the Carpathian basin. (1) Model PRECIS (run at 25 km horizontal resolution) was developed at the UK Met Office, Hadley Centre, and it uses the boundary conditions from the HadCM3 GCM. (2) Model RegCM3 (run at 10 km horizontal resolution) was developed by Giorgi et al. and it is available from the ICTP (International Centre for Theoretical Physics). Analysis of the simulated daily temperature datasets suggests that the detected regional warming is expected to continue in the 21st century. Cold temperature extremes are projected to decrease while warm extremes tend to increase significantly. Expected changes of annual precipitation indices are small, but generally consistent with the detected trends of the 20th century. Based on the simulations, extreme precipitation events are expected to become more intense and more frequent in winter, while a general decrease of extreme precipitation indices is expected in summer.

Changing Susceptibility to Non-Optimum Temperatures in Japan, 1972-2012: The Role of Climate, Demographic, and Socioeconomic Factors.

PubMed

Chung, Yeonseung; Yang, Daewon; Gasparrini, Antonio; Vicedo-Cabrera, Ana M; Fook Sheng Ng, Chris; Kim, Yoonhee; Honda, Yasushi; Hashizume, Masahiro

2018-05-02

Previous studies have shown that population susceptibility to non-optimum temperatures has changed over time, but little is known about the related time-varying factors that underlie the changes. Our objective was to investigate the changing population susceptibility to non-optimum temperatures in 47 prefectures of Japan over four decades from 1972 to 2012, addressing three aspects: minimum mortality temperature (MMT) and heat- and cold-related mortality risks. In addition, we aimed to examine how these aspects of susceptibility were associated with climate, demographic, and socioeconomic variables. We first used a two-stage time-series design with a time-varying distributed lag nonlinear model and multivariate meta-analysis to estimate the time-varying MMT, heat- and cold-related mortality risks. We then applied linear mixed effects models to investigate the association between each of the three time-varying aspects of susceptibility and various time-varying factors. MMT increased from 23.2 [95% confidence interval (CI): 23, 23.6] to 28.7 (27.0, 29.7) °C. Heat-related mortality risk [relative risk (RR) for the 99th percentile of temperature vs. the MMT] decreased from 1.18 (1.15, 1.21) to 1.01 (0.98, 1.04). Cold-related mortality risk (RR for the first percentile vs. the MMT) generally decreased from 1.48 (1.41, 1.54) to 1.35 (1.32, 1.40), with the exception of a few eastern prefectures that showed increased risk. The changing patterns in all three aspects differed by region, sex, and causes of death. Higher mean temperature was associated ( p <0.01) with lower heat risk, whereas higher humidity was associated with higher cold risk. A higher percentage of elderly people was associated with a higher cold risk, whereas higher economic strength of the prefecture was related to lower cold risk. Population susceptibility to heat has decreased over the last four decades in Japan. Susceptibility to cold has decreased overall except for several eastern prefectures where it has either increased or remained unchanged. Certain climate, demographic, and socioeconomic factors explored in the current study might underlie this changing susceptibility. https://doi.org/10.1289/EHP2546.

Summary of results of January climate simulations with the GISS coarse-mesh model

NASA Technical Reports Server (NTRS)

Spar, J.; Cohen, C.; Wu, P.

1981-01-01

The large scale climates generated by extended runs of the model are relatively independent of the initial atmospheric conditions, if the first few months of each simulation are discarded. The perpetual January simulations with a specified SST field produced excessive snow accumulation over the continents of the Northern Hemisphere. Mass exchanges between the cold (warm) continents and the warm (cold) adjacent oceans produced significant surface pressure changes over the oceans as well as over the land. The effect of terrain and terrain elevation on the amount of precipitation was examined. The evaporation of continental moisture was calculated to cause large increases in precipitation over the continents.

Endless cold: a seasonal reconstruction of temperature and precipitation in the Burgundian Low Countries during the 15th century based on documentary evidence

NASA Astrophysics Data System (ADS)

Camenisch, C.

2015-08-01

This paper applies the methods of historical climatology to present a climate reconstruction for the area of the Burgundian Low Countries during the 15th century. The results are based on documentary evidence that has been handled very carefully, especially with regard to the distinction between contemporary and non-contemporary sources. Approximately 3000 written records derived from about 100 different sources were examined and converted into seasonal seven-degree indices for temperature and precipitation. For the Late Middle Ages only a few climate reconstructions exist. There are even fewer reconstructions which include spring and autumn temperature or any precipitation information at all. This paper therefore constitutes a useful contribution to the understanding of climate and weather conditions in the less well researched but highly interesting 15th century. The extremely cold winter temperatures during the 1430s and an extremely cold winter in 1407/1408 are striking. Moreover, no other year in this century was as hot and dry as 1473. At the beginning and the end of the 1480s and at the beginning of the 1490s summers were considerably wetter than average.

Identifying Meteorological Controls on Open and Closed Mesoscale Cellular Convection as Associated with Marine Cold Air Outbreaks

NASA Astrophysics Data System (ADS)

McCoy, Isabel; Wood, Robert; Fletcher, Jennifer

Marine low clouds are key influencers of the climate and contribute significantly to uncertainty in model climate sensitivity due to their small scale and complex processes. Many low clouds occur in large-scale cellular patterns, known as open and closed mesoscale cellular convection (MCC), which have significantly different radiative and microphysical properties. Investigating MCC development and meteorological controls will improve our understanding of their impacts on the climate. We conducted an examination of time-varying meteorological conditions associated with satellite-determined open and closed MCC. The spatial and temporal patterns of MCC clouds were compared with key meteorological control variables calculated from ERA-Interim Reanalysis to highlight dependencies and major differences. This illustrated the influence of environmental stability and surface forcing as well as the role of marine cold air outbreaks (MCAO, the movement of cold air from polar-regions across warmer waters) in MCC cloud formation. Such outbreaks are important to open MCC development and may also influence the transition from open to closed MCC. Our results may lead to improvements in the parameterization of cloudiness and advance the simulation of marine low clouds. National Science Foundation Graduate Research Fellowship Grant (DGE-1256082).

Cow, sheep and llama manure at psychrophilic anaerobic co-digestion with low cost tubular digesters in cold climate and high altitude.

PubMed

Martí-Herrero, J; Alvarez, R; Cespedes, R; Rojas, M R; Conde, V; Aliaga, L; Balboa, M; Danov, S

2015-04-01

The aim of this research is to evaluate the co-digestion of cow and llama manure combined with sheep manure, in psychrophilic conditions and real field low cost tubular digesters adapted to cold climate. Four digesters were monitored in cold climate conditions; one fed with cow manure, a second one with llama manure, the third one with co-digestion of cow-sheep manure and the fourth one was fed with llama-sheep manure. The slurry had a mean temperature of 16.6 °C, the organic load rate was 0.44 kgvs m(-3) d(-1) and the hydraulic retention time was 80 days. After one hundred days biogas production was stable, as was the methane content and the pH of the effluent. The co-digestion of cow-sheep manure results in a biogas production increase of 100% compared to the mono-digestion of cow manure, while co-digestion of llama-sheep manure results in a decrease of 50% in biogas production with respect to mono-digestion of llama manure. Copyright © 2015 Elsevier Ltd. All rights reserved.

Temperature-Dependent Development, Cold Tolerance, and Potential Distribution of Cricotopus lebetis (Diptera: Chironomidae), a Tip Miner of Hydrilla verticillata (Hydrocharitaceae)

PubMed Central

Stratman, Karen N.; Overholt, William A.; Cuda, James P.; Mukherjee, A.; Diaz, R.; Netherland, Michael D.; Wilson, Patrick C.

2014-01-01

Abstract A chironomid midge, Cricotopus lebetis (Sublette) (Diptera: Chironomidae), was discovered attacking the apical meristems of Hydrilla verticillata (L.f. Royle) in Crystal River, Citrus Co., Florida in 1992. The larvae mine the stems of H. verticillata and cause basal branching and stunting of the plant. Temperature-dependent development, cold tolerance, and the potential distribution of the midge were investigated. The results of the temperature-dependent development study showed that optimal temperatures for larval development were between 20 and 30°C, and these data were used to construct a map of the potential number of generations per year of C. lebetis in Florida. Data from the cold tolerance study, in conjunction with historical weather data, were used to generate a predicted distribution of C. lebetis in the United States. A distribution was also predicted using an ecological niche modeling approach by characterizing the climate at locations where C. lebetis is known to occur and then finding other locations with similar climate. The distributions predicted using the two modeling approaches were not significantly different and suggested that much of the southeastern United States was climatically suitable for C. lebetis . PMID:25347841

Climate and environmental changes during the past millennium in central western Guizhou, China as recorded by Stalagmite ZJD-21

NASA Astrophysics Data System (ADS)

Kuo, Tz-Shing; Liu, Zi-Qi; Li, Hong-Chun; Wan, Nai-Jung; Shen, Chuan-Chou; Ku, Teh-Lung

2011-04-01

Stalagmite ZJD-21 (12.3-cm long) was collected from Zhijin Cave in Zhijin County, Guizhou, China. Its 210Pb profile and seven 230Th/ 234U dates indicate that the stalagmite has grown continuously for the past 1100 years. The δ18O record of ZJD-21 indicates that δ18O in the stalagmite was mainly influenced by rainfall amount and/or summer/winter rain ratio, with lighter values corresponding to wetter climatic conditions and/or more summer monsoonal rains. The ZJD-21 δ18O record suggests: (1) dry/warm climates during AD 950-1100 (overlapping with most of the Medieval Warm Period, MWP, in Europe); (2) strengthening of the summer monsoon from the MWP toward the beginning of the Little Ice Age (LIA) at AD 1250; (3) relatively wet/cold conditions occurred between AD 1250 and 1500, shown by relatively light δ18O values; (4) the summer monsoon intensity strongly declined referred by the increase δ18O trend from AD 1500 to AD 1600, perhaps resulting in dry/cold conditions; and (5) a strongly enhancement of the summer monsoon intensity appeared from AD 1700 to 1950, reflecting wet/cold conditions during the late period of the LIA. On decadal scales the monsoonal climate of central western Guizhou can be either warm/wet and cold/dry, or warm/dry and cold/wet. The δ13C variations in ZJD-21 on decadal-to-centennial scales respond mainly to vegetation changes with heavier values reflecting lesser amount of forest coverage. Prior to AD 1700, the δ13C generally co-varied with δ18O reflecting the expected more extensive vegetation growth (lighter δ13C) under wetter climate (lighter δ18O). However, during the past 300 years the δ13C increased sharply showing an opposite trend to that of δ18O. This observation strongly suggests that a decline of surface vegetation due to an artificial deforestation might have occurred - an occurrence coincident with the large-scale immigration into central western Guizhou in connection with copper-mining activities during the reign of Emperor Yongzheng of Qing Dynasty. Since the late 1890s, especially in the past 50 years, population surge has led to serious karst rocky desertification in the area.

Cell physiology of plants growing in cold environments.

PubMed

Lütz, Cornelius

2010-08-01

The life of plants growing in cold extreme environments has been well investigated in terms of morphological, anatomical, and ecophysiological adaptations. In contrast, long-term cellular or metabolic studies have been performed by only a few groups. Moreover, a number of single reports exist, which often represent just a glimpse of plant behavior. The review draws together the literature which has focused on tissue and cellular adaptations mainly to low temperatures and high light. Most studies have been done with European alpine plants; comparably well studied are only two phanerogams found in the coastal Antarctic. Plant adaptation in northern polar regions has always been of interest in terms of ecophysiology and plant propagation, but nowadays, this interest extends to the effects of global warming. More recently, metabolic and cellular investigations have included cold and UV resistance mechanisms. Low-temperature stress resistance in plants from cold environments reflects the climate conditions at the growth sites. It is now a matter of molecular analyses to find the induced genes and their products such as chaperones or dehydrins responsible for this resistance. Development of plants under snow or pollen tube growth at 0 degrees C shows that cell biology is needed to explain the stability and function of the cytoskeleton. Many results in this field are based on laboratory studies, but several publications show that it is not difficult to study cellular mechanisms with the plants adapted to a natural stress. Studies on high light and UV loads may be split in two parts. Many reports describe natural UV as harmful for the plants, but these studies were mainly conducted by shielding off natural UV (as controls). Other experiments apply additional UV in the field and have had practically no negative impact on metabolism. The latter group is supported by the observations that green overwintering plants increase their flavonoids under snow even in the absence of UV. Thus, their defense and antioxidant role dominates. Ultrastructural comparisons were unable to find special light adaptations in plants taken from polar regions vs. high alpine species. The only adaptation found at the subcellular level for most alpine and polar plants are protrusions of the chloroplast envelopes. They are seen as a demand for fast membrane transport requiring additional membrane surface area, whereby the increase in stroma volume may help to support carbohydrate formation. Plants forming such protrusions have to cope with a short vegetation time. These observations are connected to the question as to how photosynthesis works quite well even at or under zero temperatures. The interplay between plastids, mitochondria, and peroxisomes, known as photorespiration, seems to be more intense than in lowland plants. This organelle cooperation serves as a valve for a surplus in solar energy input under cold conditions. Additional metabolic acclimations are under investigation, such as the role of an alternative plastid terminal oxidase. Plants from cold environments may also be seen as ideal objects for studying the combined effects of high light plus cold resistance-from the molecular level to the whole plant adaptation. Modern instrumentation makes it possible to perform vital metabolic measurements under outdoor conditions, and research stations in remote polar and alpine areas provide support for scientists in the preparation of samples for later cellular studies in the home laboratory.

Nasal airflow simulations suggest convergent adaptation in Neanderthals and modern humans.

PubMed

de Azevedo, S; González, M F; Cintas, C; Ramallo, V; Quinto-Sánchez, M; Márquez, F; Hünemeier, T; Paschetta, C; Ruderman, A; Navarro, P; Pazos, B A; Silva de Cerqueira, C C; Velan, O; Ramírez-Rozzi, F; Calvo, N; Castro, H G; Paz, R R; González-José, R

2017-11-21

Both modern humans (MHs) and Neanderthals successfully settled across western Eurasian cold-climate landscapes. Among the many adaptations considered as essential to survival in such landscapes, changes in the nasal morphology and/or function aimed to humidify and warm the air before it reaches the lungs are of key importance. Unfortunately, the lack of soft-tissue evidence in the fossil record turns difficult any comparative study of respiratory performance. Here, we reconstruct the internal nasal cavity of a Neanderthal plus two representatives of climatically divergent MH populations (southwestern Europeans and northeastern Asians). The reconstruction includes mucosa distribution enabling a realistic simulation of the breathing cycle in different climatic conditions via computational fluid dynamics. Striking across-specimens differences in fluid residence times affecting humidification and warming performance at the anterior tract were found under cold/dry climate simulations. Specifically, the Asian model achieves a rapid air conditioning, followed by the Neanderthals, whereas the European model attains a proper conditioning only around the medium-posterior tract. In addition, quantitative-genetic evolutionary analyses of nasal morphology provided signals of stabilizing selection for MH populations, with the removal of Arctic populations turning covariation patterns compatible with evolution by genetic drift. Both results indicate that, departing from important craniofacial differences existing among Neanderthals and MHs, an advantageous species-specific respiratory performance in cold climates may have occurred in both species. Fluid dynamics and evolutionary biology independently provided evidence of nasal evolution, suggesting that adaptive explanations regarding complex functional phenotypes require interdisciplinary approaches aimed to quantify both performance and evolutionary signals on covariation patterns.

Ocean Drilling Program Records of the Last Five Million Years: A View of the Ocean and Climate System During a Warm Period and a Major Climate Transition

NASA Astrophysics Data System (ADS)

Ravelo, A. C.

2003-12-01

The warm Pliocene (4.7 to 3.0 Ma), the most recent period in Earth's history when global equilibrium climate was warmer than today, provides the opportunity to understand what role the components of the climate system that have a long timescale of response (cryosphere and ocean) play in determining globally warm conditions, and in forcing the major global climate cooling after 3.0 Ma. Because sediments of this age are well preserved in many locations in the world's oceans, we can potentially study this warm period in detail. One major accomplishment of the Ocean Drilling Program is the recovery of long continuous sediment sequences from all ocean basins that span the last 5.0 Ma. Dozens of paleoceanographers have generated climate records from these sediments. I will present a synthesis of these data to provide a global picture of the Pliocene warm period, the transition to the cold Pleistocene period, and changes in climate sensitivity related to this transition. In the Pliocene warm period, tropical sea surface temperature (SST) and global climate patterns suggest average conditions that resemble modern El Ni¤os, and deep ocean reconstructions indicate enhanced thermohaline overturning and reduced density and nutrient stratification. The data indicate that the warm conditions were not related to tectonic changes in ocean basin shape compared to today, rather they reflect the long term adjustment of the climate system to stronger than modern radiative forcing. The warm Pliocene to cold Pleistocene transition provides an opportunity to study the feedbacks of various components of the climate system. The marked onset of significant Northern hemisphere glaciation (NHG) at 2.75 Ma occurred in concert with a reduction in deep ocean ventilation, but cooling in subtropical and tropical regions was more gradual until Walker circulation was established in a major step at 2.0 Ma. Thus, regional high latitude ice albedo feedbacks, rather than low latitude processes, must have been primarily responsible for NHG at 2.75 Ma. And, regional air-sea feedbacks in the tropics, rather than ice sheet expansion, must have been primarily responsible for the marked increase in Walker circulation at 2.0 Ma. Finally, the detailed timing of events from different regions suggests that a tectonic `threshold' cannot explain the warm to cold climate transition. Studies of the last 5.0 Ma can also be used to understand how climate responds to changes in the Earth's radiative budget because seasonal and latitudinal variations in solar forcing are extremely well known, and many of the records that have been generated have the resolution and age control appropriate for the study of the climate response to these variations (Milankovitch cycles). In particular, how feedbacks operate when the mean climate state is warm versus cold can be studied. There is clear evidence that the amplitude of the climate response to solar forcing depends on the background mean state. In other words, the sensitivity of the climate to small perturbations in solar forcing has changed with time, and the balance of evidence indicates that tropical conditions, not high latitude conditions (such as ice sheet size) control this sensitivity. In sum, the Ocean Drilling Program has provided scientists with a window into the Pliocene warm period, and an opportunity to understand the workings of the ocean-climate system

Basking behavior predicts the evolution of heat tolerance in Australian rainforest lizards.

PubMed

Muñoz, Martha M; Langham, Gary M; Brandley, Matthew C; Rosauer, Dan F; Williams, Stephen E; Moritz, Craig

2016-11-01

There is pressing urgency to understand how tropical ectotherms can behaviorally and physiologically respond to climate warming. We examine how basking behavior and thermal environment interact to influence evolutionary variation in thermal physiology of multiple species of lygosomine rainforest skinks from the Wet Tropics of northeastern Queensland, Australia (AWT). These tropical lizards are behaviorally specialized to exploit canopy or sun, and are distributed across marked thermal clines in the AWT. Using phylogenetic analyses, we demonstrate that physiological parameters are either associated with changes in local thermal habitat or to basking behavior, but not both. Cold tolerance, the optimal sprint speed, and performance breadth are primarily influenced by local thermal environment. Specifically, montane lizards are more cool tolerant, have broader performance breadths, and higher optimum sprinting temperatures than their lowland counterparts. Heat tolerance, in contrast, is strongly affected by basking behavior: there are two evolutionary optima, with basking species having considerably higher heat tolerance than shade skinks, with no effect of elevation. These distinct responses among traits indicate the multiple selective pressures and constraints that shape the evolution of thermal performance. We discuss how behavior and physiology interact to shape organisms' vulnerability and potential resilience to climate change. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

Conflicts of thermal adaptation and fever--a cybernetic approach based on physiological experiments.

PubMed

Werner, J; Beckmann, U

1998-01-01

Cold adaptation aims primarily at a better economy, i.e., preservation of energy often at the cost of a lower mean body temperature during cold stress, whereas heat adaptation whether achieved by exposure to a hot environment or by endogenous heat produced by muscle exercise, often brings about a higher efficiency of control, i.e., a lower mean body temperature during heat stress, at the cost of a higher water loss. While cold adaptation is beneficial in a cold environment, it may constitute a detrimental factor for exposure to a hot environment, mainly because of morphological adaptation. Heat adaptation may be maladaptive for cold exposure, mainly because of functional adaptation. Heat adaptation clearly is best suited to avoid higher body temperatures in fever, no matter which environmental conditions prevail. On the other hand, cold adaptation is detrimental for coping with fever in hot environment. Yet, in the cold, preceding cold adaptation may, because of reduced metabolic heat production, result in lower febrile increase of body temperature. Apparently controversial effects and results may be analyzed in the framework of a cybernetic approach to the main mechanisms of thermal adaptation and fever. Morphological adaptations alter the properties of the heat transfer characteristics of the body ("passive system"), whereas functional adaptation and fever concern the subsystems of control, namely sensors, integrative centers and effectors. In a closed control-loop the two types of adaptation have totally different consequences. It is shown that the experimental results are consistent with the predictions of such an approach.

Nordic Winter and Cold: Their Correspondence with Tomas Tranströmer's Poetry

ERIC Educational Resources Information Center

Hosian, Mohammad Akbar

2015-01-01

The Nobel Prize winning poet Tomas Tranströmer was born and bred in Sweden, a remarkably Scandinavian country. Topographically, Scandinavian countries are locations of extreme cold and snowing. This distinguishing climatic condition has had a dominant influence and impact on almost all Scandinavian art and literature, including Tomas Tranströmer's…

Population-level thermal performance of a cold-water ectotherm is linked to ontogeny and local environmental heterogeneity

USGS Publications Warehouse

Hossack, Blake R.; Corn, P. Stephen; , Winsor H. Lowe; , Molly A. H. Webb; , Mariah J. Talbott; , Kevin M. Kappenman

2013-01-01

5. Our experiments with a cold-water species show that population-level performance varies across small geographic scales and is linked to local environmental heterogeneity. This variation could influence the rate and mode of species-level responses to climate change, both by facilitating local persistence in the face of change

Tolerance of subzero winter cold in kudzu (Pueraria montana var. lobata) and its implications for northward migration in a warming climate

USDA-ARS?s Scientific Manuscript database

Kudzu (Pueraria montana var. lobata) is an important invasive species that was planted throughout southeastern North America until the mid-20th century. Winter survival is commonly assumed to control its distribution; however, its cold tolerance thresholds have not been determined. Here, we used bio...

Lubricants for Hydraulic Structures

DTIC Science & Technology

1989-08-01

significant difference is the fact that paraffinics provide a higher pour point. Although this is of little con- cern in warm climates , it could be...significant in very cold climates . 194. Lubricating oils may be either paraffinic or naphthenic depending on intended use, but there are no restrictions...geographical and climatic conditions, freedom to adjust to local conditions is recommended. 59 Table 1 Common Additives for Industrial Oils Rust

Tolerance to multiple climate stressors: a case study of Douglas-fir drought and cold hardiness

Treesearch

Sheel Bansal; Connie Harrington; Brad St. Clair

2016-01-01

1. Drought and freeze events are two of the most common forms of climate extremes which result in tree damage or death, and the frequency and intensity of both stressors may increase with climate change. Few studies have examined natural covariation in stress tolerance traits to cope with multiple stressors among wild plant populations. 2. We assessed the...

Cold-sensing regulates Drosophila growth through insulin-producing cells

PubMed Central

Li, Qiaoran; Gong, Zhefeng

2015-01-01

Across phyla, body size is linked to climate. For example, rearing fruit flies at lower temperatures results in bigger body sizes than those observed at higher temperatures. The underlying molecular basis of this effect is poorly understood. Here we provide evidence that the temperature-dependent regulation of Drosophila body size depends on a group of cold-sensing neurons and insulin-producing cells (IPCs). Electrically silencing IPCs completely abolishes the body size increase induced by cold temperature. IPCs are directly innervated by cold-sensing neurons. Stimulation of these cold-sensing neurons activates IPCs, promotes synthesis and secretion of Drosophila insulin-like peptides and induces a larger body size, mimicking the effects of rearing the flies in cold temperature. Taken together, these findings reveal a neuronal circuit that mediates the effects of low temperature on fly growth. PMID:26648410

Preservation of Late Amazonian Mars ice and water-related deposits in a unique crater environment in Noachis Terra: Age relationships between lobate debris tongues and gullies

NASA Astrophysics Data System (ADS)

Morgan, Gareth A.; Head, James W.; Marchant, David R.

2011-01-01

The Amazonian period of Mars has been described as static, cold, and dry. Recent analysis of high-resolution imagery of equatorial and mid-latitude regions has revealed an array of young landforms produced in association with ice and liquid water; because near-surface ice in these regions is currently unstable, these ice-and-water-related landforms suggest one or more episodes of martian climate change during the Amazonian. Here we report on the origin and evolution of valley systems within a degraded crater in Noachis Terra, Asimov Crater. The valleys have produced a unique environment in which to study the geomorphic signals of Amazonian climate change. New high-resolution images reveal Hesperian-aged layered basalt with distinctive columnar jointing capping interior crater fill and providing debris, via mass wasting, for the surrounding annular valleys. The occurrence of steep slopes (>20°), relatively narrow (sheltered) valleys, and a source of debris have provided favorable conditions for the preservation of shallow-ice deposits. Detailed mapping reveals morphological evidence for viscous ice flow, in the form of several lobate debris tongues (LDT). Superimposed on LDT are a series of fresh-appearing gullies, with typical alcove, channel, and fan morphologies. The shift from ice-rich viscous-flow formation to gully erosion is best explained as a shift in martian climate, from one compatible with excess snowfall and flow of ice-rich deposits, to one consistent with minor snow and gully formation. Available dating suggests that the climate transition occurred >8 Ma, prior to the formation of other small-scale ice-rich flow features identified elsewhere on Mars that have been interpreted to have formed during the most recent phases of high obliquity. Taken together, these older deposits suggest that multiple climatic shifts have occurred over the last tens of millions of years of martian history.

Climate impacts on northern Canada: regional background.

PubMed

Prowse, Terry D; Furgal, Chris; Bonsal, Barrie R; Peters, Daniel L

2009-07-01

Understanding the implications of climate change on northern Canada requires a background about the size and diversity of its human and biogeophysical systems. Occupying an area of almost 40% of Canada, with one-third of this contained in Arctic islands, Canada's northern territories consist of a diversity of physical environments unrivaled around the circumpolar north. Major ecozones composed of a range of landforms, climate, vegetation, and wildlife include: Arctic, boreal and taiga cordillera; boreal and taiga plains; taiga shield; and northern and southern Arctic. Although generally characterized by a cold climate, there is an enormous range in air temperature with mean annual values being as high as -5 degrees C in the south to as low as -20 degrees C in the high Arctic islands. A similar contrast characterizes precipitation, which can be > 700 mm y(-1) in some southern alpine regions to as low as 50 mm y(-1) over islands of the high Arctic. Major freshwater resources are found within most northern ecozones, varying from large glaciers or ice caps and lakes to extensive wetlands and peat lands. Most of the North's renewable water, however, is found within its major river networks and originates in more southerly headwaters. Ice covers characterize the freshwater systems for multiple months of the year while permafrost prevails in various forms, dominating the terrestrial landscape. The marine environment, which envelops the Canadian Arctic Archipelago, is dominated by seasonal to multiyear sea ice often several meters thick that plays a key role in the regional climate. Almost two-thirds of northern Canadian communities are located along coastlines with the entire population being just over 100 000. Most recent population growth has been dominated by an expansion of nonaboriginals, primarily the result of resource development and the growth of public administration. The economies of northern communities, however, remain quite mixed with traditional land-based renewable resource-subsistence activities still being a major part of many local economies.

Diving into Cold Pools

NASA Astrophysics Data System (ADS)

van den Heever, S. C.; Grant, L. D.; Drager, A. J.

2017-12-01

Cold pools play a significant role in convective storm initiation, organization and longevity. Given their role in convective life cycles, recent efforts have been focused on improving the representation of cold pool processes within weather forecast models, as well as on developing cold pool parameterizations in order to better represent their impacts within global climate models. Understanding the physical processes governing cold pool formation, intensity and dissipation is therefore critical to these efforts. Cold pool characteristics are influenced by numerous factors, including those associated with precipitation formation and evaporation, variations in the environmental moisture and shear, and land surface interactions. The focus of this talk will be on the manner in which the surface characteristics and associated processes impact cold pool genesis and dissipation. In particular, the results from high-resolution modeling studies focusing on the role of sensible and latent heat fluxes, soil moisture and SST will be presented. The results from a recent field campaign examining cold pools over northern Colorado will also be discussed.

Hydrologic responses of a tropical catchment in Thailand and two temperate/cold catchments in north America to global warming

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gan, T.Y.; Ahmad, Z.

The hydrologic impact or sensitivities of three medium-sized catchments to global warming, one of tropical climate in Northern Thailand and two of temperate climate in the Sacramento and San Joaquin River basins of California, were investigated.

Climate change impacts on extreme temperature mortality in select metropolitan areas of the United States

EPA Science Inventory

Projected mortality from climate change-driven impacts on extremely hot and cold days increases significantly over the 21st century in a large group of United States Metropolitan Statistical Areas. Increases in projected mortality from more hot days are greater than decreases in ...

How Can Conventional Drinking Water Treatment Facilities Build Resilience to Climate and Weather Induced Water Supply Variability?

EPA Science Inventory

Abstract: Water supplies are vulnerable to a host of climate- and weather-related stressors such as droughts, intense storms/flooding, snowpack depletion, sea level changes, and consequences from fires, landslides, and excessive heat or cold. Surface water resources (lakes, reser...

Do climate model predictions agree with long-term precipitation trends in the arid southwestern United States?

USDA-ARS?s Scientific Manuscript database

Researchers evaluating climate projections across southwestern North America observed a decreasing precipitation trend. Aridification was most pronounced in the cold (non-monsoonal) season, whereas downward trends in precipitation were smaller in the warm (monsoonal) season. In this region, based up...

Macro-Climatic Distribution Limits Show Both Niche Expansion and Niche Specialization among C4 Panicoids.

PubMed

Aagesen, Lone; Biganzoli, Fernando; Bena, Julia; Godoy-Bürki, Ana C; Reinheimer, Renata; Zuloaga, Fernando O

2016-01-01

Grasses are ancestrally tropical understory species whose current dominance in warm open habitats is linked to the evolution of C4 photosynthesis. C4 grasses maintain high rates of photosynthesis in warm and water stressed environments, and the syndrome is considered to induce niche shifts into these habitats while adaptation to cold ones may be compromised. Global biogeographic analyses of C4 grasses have, however, concentrated on diversity patterns, while paying little attention to distributional limits. Using phylogenetic contrast analyses, we compared macro-climatic distribution limits among ~1300 grasses from the subfamily Panicoideae, which includes 4/5 of the known photosynthetic transitions in grasses. We explored whether evolution of C4 photosynthesis correlates with niche expansions, niche changes, or stasis at subfamily level and within the two tribes Paniceae and Paspaleae. We compared the climatic extremes of growing season temperatures, aridity, and mean temperatures of the coldest months. We found support for all the known biogeographic distribution patterns of C4 species, these patterns were, however, formed both by niche expansion and niche changes. The only ubiquitous response to a change in the photosynthetic pathway within Panicoideae was a niche expansion of the C4 species into regions with higher growing season temperatures, but without a withdrawal from the inherited climate niche. Other patterns varied among the tribes, as macro-climatic niche evolution in the American tribe Paspaleae differed from the pattern supported in the globally distributed tribe Paniceae and at family level.

Patterns of species diversity and phylogenetic structure of vascular plants on the Qinghai-Tibetan Plateau.

PubMed

Yan, Yujing; Yang, Xian; Tang, Zhiyao

2013-11-01

Large-scale patterns of species richness and the underlying mechanisms regulating these patterns have long been the central issues in biogeography and macroecology. Phylogenetic community structure is a result of combined effects of contemporary ecological interactions, environmental filtering, and evolutionary history, and it links community ecology with biogeography and trait evolution. The Qinghai-Tibetan Plateau provides a good opportunity to test the influence of contemporary climate on shaping species richness because of its unique geological history, cold climate, and high biodiversity. In this study, based on high-resolution distributions of ˜9000 vascular plant species, we explored how species richness and phylogenetic structure of vascular plants correlate with climates on the highest (and species rich) plateau on the Earth. The results showed that most of the vascular plants were distributed on the eastern part of the plateau; there was a strong association between species richness and climate, even after the effects of habitat heterogeneity were controlled. However, the responses of richness to climate remarkably depended on life-forms. Richness of woody plants showed stronger climatic associations than that of herbaceous plants; energy and water availability together regulated richness pattern of woody plants; whereas water availability predominantly regulated richness pattern of herbaceous plants. The phylogenetic structure of vascular species clustered in most areas of the plateau, suggesting that rapid speciation and environment filtering dominated the assembly of communities on the plateau. We further propose that biodiversity conservation in this area should better take into account ecological features for different life-forms and phylogenetic lineages.

Patterns of species diversity and phylogenetic structure of vascular plants on the Qinghai-Tibetan Plateau

PubMed Central

Yan, Yujing; Yang, Xian; Tang, Zhiyao

2013-01-01

Large-scale patterns of species richness and the underlying mechanisms regulating these patterns have long been the central issues in biogeography and macroecology. Phylogenetic community structure is a result of combined effects of contemporary ecological interactions, environmental filtering, and evolutionary history, and it links community ecology with biogeography and trait evolution. The Qinghai-Tibetan Plateau provides a good opportunity to test the influence of contemporary climate on shaping species richness because of its unique geological history, cold climate, and high biodiversity. In this study, based on high-resolution distributions of ˜9000 vascular plant species, we explored how species richness and phylogenetic structure of vascular plants correlate with climates on the highest (and species rich) plateau on the Earth. The results showed that most of the vascular plants were distributed on the eastern part of the plateau; there was a strong association between species richness and climate, even after the effects of habitat heterogeneity were controlled. However, the responses of richness to climate remarkably depended on life-forms. Richness of woody plants showed stronger climatic associations than that of herbaceous plants; energy and water availability together regulated richness pattern of woody plants; whereas water availability predominantly regulated richness pattern of herbaceous plants. The phylogenetic structure of vascular species clustered in most areas of the plateau, suggesting that rapid speciation and environment filtering dominated the assembly of communities on the plateau. We further propose that biodiversity conservation in this area should better take into account ecological features for different life-forms and phylogenetic lineages. PMID:24340197

Cold Climate Foundation Retrofit Experimental Hygrothermal Performance. Cloquet Residential Research Facility Laboratory Results

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goldberg, Louise F.; Harmon, Anna C.

2015-04-09

This project was funded jointly by the National Renewable Energy Laboratory (NREL) and Oak Ridge National Laboratory (ORNL). ORNL focused on developing a full basement wall system experimental database to enable others to validate hygrothermal simulation codes. NREL focused on testing the moisture durability of practical basement wall interior insulation retrofit solutions for cold climates. The project has produced a physically credible and reliable long-term hygrothermal performance database for retrofit foundation wall insulation systems in zone 6 and 7 climates that are fully compliant with the performance criteria in the 2009 Minnesota Energy Code. These data currently span the periodmore » from November 10, 2012 through May 31, 2014 and are anticipated to be extended through November 2014. The experimental data were configured into a standard format that can be published online and that is compatible with standard commercially available spreadsheet and database software.« less

Variability in winter climate and winter extremes reduces population growth of an alpine butterfly.

PubMed

Roland, Jens; Matter, Stephen F

2013-01-01

We examined the long-term, 15-year pattern of population change in a network of 21 Rocky Mountain populations of Parnassius smintheus butterflies in response to climatic variation. We found that winter values of the broadscale climate variable, the Pacific Decadal Oscillation (PDO) index, were a strong predictor of annual population growth, much more so than were endogenous biotic factors related to population density. The relationship between PDO and population growth was nonlinear. Populations declined in years with extreme winter PDO values, when there were either extremely warm or extremely cold sea surface temperatures in the eastern Pacific relative to that in the western Pacific. Results suggest that more variable winters, and more frequent extremely cold or warm winters, will result in more frequent decline of these populations, a pattern exacerbated by the trend for increasingly variable winters seen over the past century.

Strategy Guideline: Energy Retrofits for Low-Rise Multifamily Buildings in Cold Climates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frozyna, K.; Badger, L.

2013-04-01

This Strategy Guideline explains the benefits of evaluating and identifying energy efficiency retrofit measures that could be made during renovation and maintenance of multifamily buildings. It focuses on low-rise multifamily structures (three or fewer stories) in a cold climate. These benefits lie primarily in reduced energy use, lower operating and maintenance costs, improved durability of the structure, and increased occupant comfort. This guideline focuses on retrofit measures for roof repair or replacement, exterior wall repair or gut rehab, and eating system maintenance. All buildings are assumed to have a flat ceiling and a trussed roof, wood- or steel-framed exterior walls,more » and one or more single or staged boilers. Estimated energy savings realized from the retrofits will vary, depending on the size and condition of the building, the extent of efficiency improvements, the efficiency of the heating equipment, the cost and type of fuel, and the climate location.« less

FishVis, A regional decision support tool for identifying vulnerabilities of riverine habitat and fishes to climate change in the Great Lakes Region

USGS Publications Warehouse

Stewart, Jana S.; Covert, S. Alex; Estes, Nick J.; Westenbroek, Stephen M.; Krueger, Damon; Wieferich, Daniel J.; Slattery, Michael T.; Lyons, John D.; McKenna, James E.; Infante, Dana M.; Bruce, Jennifer L.

2016-10-13

Climate change is expected to alter the distributions and community composition of stream fishes in the Great Lakes region in the 21st century, in part as a result of altered hydrological systems (stream temperature, streamflow, and habitat). Resource managers need information and tools to understand where fish species and stream habitats are expected to change under future conditions. Fish sample collections and environmental variables from multiple sources across the United States Great Lakes Basin were integrated and used to develop empirical models to predict fish species occurrence under present-day climate conditions. Random Forests models were used to predict the probability of occurrence of 13 lotic fish species within each stream reach in the study area. Downscaled climate data from general circulation models were integrated with the fish species occurrence models to project fish species occurrence under future climate conditions. The 13 fish species represented three ecological guilds associated with water temperature (cold, cool, and warm), and the species were distributed in streams across the Great Lakes region. Vulnerability (loss of species) and opportunity (gain of species) scores were calculated for all stream reaches by evaluating changes in fish species occurrence from present-day to future climate conditions. The 13 fish species included 4 cold-water species, 5 cool-water species, and 4 warm-water species. Presently, the 4 cold-water species occupy from 15 percent (55,000 kilometers [km]) to 35 percent (130,000 km) of the total stream length (369,215 km) across the study area; the 5 cool-water species, from 9 percent (33,000 km) to 58 percent (215,000 km); and the 4 warm-water species, from 9 percent (33,000 km) to 38 percent (141,000 km).Fish models linked to projections from 13 downscaled climate models projected that in the mid to late 21st century (2046–65 and 2081–2100, respectively) habitats suitable for all 4 cold-water species and 4 of 5 cool-water species under present-day conditions will decline as much as 86 percent and as little as 33 percent, and habitats suitable for all 4 warm-water species will increase as much as 33 percent and as little as 7 percent. This report documents the approach and data used to predict and project fish species occurrence under present-day and future climate conditions for 13 lotic fish species in the United States Great Lakes Basin. A Web-based decision support mapping application termed “FishVis” was developed to provide a means to integrate, visualize, query, and download the results of these projected climate-driven responses and help inform conservation planning efforts within the region.

Phenol degradation and heavy metal tolerance of Antarctic yeasts.

PubMed

Fernández, Pablo Marcelo; Martorell, María Martha; Blaser, Mariana G; Ruberto, Lucas Adolfo Mauro; de Figueroa, Lucía Inés Castellanos; Mac Cormack, Walter Patricio

2017-05-01

In cold environments, biodegradation of organic pollutants and heavy metal bio-conversion requires the activity of cold-adapted or cold-tolerant microorganisms. In this work, the ability to utilize phenol, methanol and n-hexadecane as C source, the tolerance to different heavy metals and growth from 5 to 30 °C were evaluated in cold-adapted yeasts isolated from Antarctica. Fifty-nine percent of the yeasts were classified as psychrotolerant as they could grow in all the range of temperature tested, while the other 41% were classified as psychrophilic as they only grew below 25 °C. In the assimilation tests, 32, 78, and 13% of the yeasts could utilize phenol, n-hexadecane, and methanol as C source, respectively, but only 6% could assimilate the three C sources evaluated. In relation to heavy metals ions, 55, 68, and 80% were tolerant to 1 mM of Cr(VI), Cd(II), and Cu(II), respectively. Approximately a half of the isolates tolerated all of them. Most of the selected yeasts belong to genera previously reported as common for Antarctic soils, but several other genera were also isolated, which contribute to the knowledge of this cold environment mycodiversity. The tolerance to heavy metals of the phenol-degrading cold-adapted yeasts illustrated that the strains could be valuable as inoculant for cold wastewater treatment in extremely cold environments.