Science.gov

Sample records for future heat extremes

  1. Future population exposure to US heat extremes

    NASA Astrophysics Data System (ADS)

    Jones, Bryan; O'Neill, Brian C.; McDaniel, Larry; McGinnis, Seth; Mearns, Linda O.; Tebaldi, Claudia

    2015-07-01

    Extreme heat events are likely to become more frequent in the coming decades owing to climate change. Exposure to extreme heat depends not only on changing climate, but also on changes in the size and spatial distribution of the human population. Here we provide a new projection of population exposure to extreme heat for the continental United States that takes into account both of these factors. Using projections from a suite of regional climate models driven by global climate models and forced with the SRES A2 scenario and a spatially explicit population projection consistent with the socioeconomic assumptions of that scenario, we project changes in exposure into the latter half of the twenty-first century. We find that US population exposure to extreme heat increases four- to sixfold over observed levels in the late twentieth century, and that changes in population are as important as changes in climate in driving this outcome. Aggregate population growth, as well as redistribution of the population across larger US regions, strongly affects outcomes whereas smaller-scale spatial patterns of population change have smaller effects. The relative importance of population and climate as drivers of exposure varies across regions of the country.

  2. Elevated CO2 maintains grassland net carbon uptake under a future heat and drought extreme

    PubMed Central

    Roy, Jacques; Picon-Cochard, Catherine; Augusti, Angela; Benot, Marie-Lise; Thiery, Lionel; Darsonville, Olivier; Landais, Damien; Piel, Clément; Defossez, Marc; Devidal, Sébastien; Escape, Christophe; Ravel, Olivier; Fromin, Nathalie; Volaire, Florence; Milcu, Alexandru; Bahn, Michael; Soussana, Jean-François

    2016-01-01

    Extreme climatic events (ECEs) such as droughts and heat waves are predicted to increase in intensity and frequency and impact the terrestrial carbon balance. However, we lack direct experimental evidence of how the net carbon uptake of ecosystems is affected by ECEs under future elevated atmospheric CO2 concentrations (eCO2). Taking advantage of an advanced controlled environment facility for ecosystem research (Ecotron), we simulated eCO2 and extreme cooccurring heat and drought events as projected for the 2050s and analyzed their effects on the ecosystem-level carbon and water fluxes in a C3 grassland. Our results indicate that eCO2 not only slows down the decline of ecosystem carbon uptake during the ECE but also enhances its recovery after the ECE, as mediated by increases of root growth and plant nitrogen uptake induced by the ECE. These findings indicate that, in the predicted near future climate, eCO2 could mitigate the effects of extreme droughts and heat waves on ecosystem net carbon uptake. PMID:27185934

  3. Elevated CO2 maintains grassland net carbon uptake under a future heat and drought extreme.

    PubMed

    Roy, Jacques; Picon-Cochard, Catherine; Augusti, Angela; Benot, Marie-Lise; Thiery, Lionel; Darsonville, Olivier; Landais, Damien; Piel, Clément; Defossez, Marc; Devidal, Sébastien; Escape, Christophe; Ravel, Olivier; Fromin, Nathalie; Volaire, Florence; Milcu, Alexandru; Bahn, Michael; Soussana, Jean-François

    2016-05-31

    Extreme climatic events (ECEs) such as droughts and heat waves are predicted to increase in intensity and frequency and impact the terrestrial carbon balance. However, we lack direct experimental evidence of how the net carbon uptake of ecosystems is affected by ECEs under future elevated atmospheric CO2 concentrations (eCO2). Taking advantage of an advanced controlled environment facility for ecosystem research (Ecotron), we simulated eCO2 and extreme cooccurring heat and drought events as projected for the 2050s and analyzed their effects on the ecosystem-level carbon and water fluxes in a C3 grassland. Our results indicate that eCO2 not only slows down the decline of ecosystem carbon uptake during the ECE but also enhances its recovery after the ECE, as mediated by increases of root growth and plant nitrogen uptake induced by the ECE. These findings indicate that, in the predicted near future climate, eCO2 could mitigate the effects of extreme droughts and heat waves on ecosystem net carbon uptake. PMID:27185934

  4. Extreme European heat waves since 1950 with Heat Wave Magnitude Index and their occurrence in the future

    NASA Astrophysics Data System (ADS)

    Russo, Simone; Dosio, Alessandro; Sillmann, Jana

    2015-04-01

    Heat waves are defined as prolonged periods of extremely hot weather and their magnitude and frequency are expected to increase in the future under climate change. Here we grade the heat waves occurred in Europe since 1950, by means of the Heat Wave Magnitude Index (HWMI) applied to daily maximum temperature from European Observation dataset (E-OBS). As shown in many studies the worst event in the last decades occurred in Russia in 2010. However many other heat waves, as shown here and documented in literature and also in newspapers, occurred in different European regions in the past 64 years. In addition, predictions from ten models from the COordinated Regional climate Downscaling EXperiment (CORDEX) under different IPCC AR5 scenarios, suggest an increased probability of occurrence of extreme heat waves by the end of the century. In particular, under the most severe scenario, events of the same severity, as the 2010 Russian heat wave, will become the norm and are projected to occur as often as every two years in the studied region.

  5. Global crop yield response to extreme heat stress under multiple climate change futures

    NASA Astrophysics Data System (ADS)

    Deryng, D.; Conway, D.; Ramankutty, N.; Price, J.; Warren, R.

    2014-12-01

    Extreme heat stress during the crop reproductive period can be critical for crop productivity. Projected changes in the frequency and severity of extreme climatic events are expected to negatively impact crop yields and global food production. This study applies the global crop model PEGASUS to quantify, for the first time at the global scale, impacts of extreme heat stress on maize, spring wheat and soybean yields resulting from 72 climate change scenarios for the 21st century. Our results project maize to face progressively worse impacts under a range of RCPs but spring wheat and soybean to improve globally through to the 2080s due to CO2 fertilization effects, even though parts of the tropic and sub-tropic regions could face substantial yield declines. We find extreme heat stress at anthesis (HSA) by the 2080s (relative to the 1980s) under RCP 8.5, taking into account CO2 fertilization effects, could double global losses of maize yield (dY = -12.8 ± 6.7% versus -7.0 ± 5.3% without HSA), reduce projected gains in spring wheat yield by half (dY = 34.3 ± 13.5% versus 72.0 ± 10.9% without HSA) and in soybean yield by a quarter (dY = 15.3 ± 26.5% versus 20.4 ± 22.1% without HSA). The range reflects uncertainty due to differences between climate model scenarios; soybean exhibits both positive and negative impacts, maize is generally negative and spring wheat generally positive. Furthermore, when assuming CO2 fertilization effects to be negligible, we observe drastic climate mitigation policy as in RCP 2.6 could avoid more than 80% of the global average yield losses otherwise expected by the 2080s under RCP 8.5. We show large disparities in climate impacts across regions and find extreme heat stress adversely affects major producing regions and lower income countries.

  6. Global crop yield response to extreme heat stress under multiple climate change futures

    NASA Astrophysics Data System (ADS)

    Deryng, Delphine; Conway, Declan; Ramankutty, Navin; Price, Jeff; Warren, Rachel

    2014-03-01

    Extreme heat stress during the crop reproductive period can be critical for crop productivity. Projected changes in the frequency and severity of extreme climatic events are expected to negatively impact crop yields and global food production. This study applies the global crop model PEGASUS to quantify, for the first time at the global scale, impacts of extreme heat stress on maize, spring wheat and soybean yields resulting from 72 climate change scenarios for the 21st century. Our results project maize to face progressively worse impacts under a range of RCPs but spring wheat and soybean to improve globally through to the 2080s due to CO2 fertilization effects, even though parts of the tropic and sub-tropic regions could face substantial yield declines. We find extreme heat stress at anthesis (HSA) by the 2080s (relative to the 1980s) under RCP 8.5, taking into account CO2 fertilization effects, could double global losses of maize yield (ΔY = -12.8 ± 6.7% versus - 7.0 ± 5.3% without HSA), reduce projected gains in spring wheat yield by half (ΔY = 34.3 ± 13.5% versus 72.0 ± 10.9% without HSA) and in soybean yield by a quarter (ΔY = 15.3 ± 26.5% versus 20.4 ± 22.1% without HSA). The range reflects uncertainty due to differences between climate model scenarios; soybean exhibits both positive and negative impacts, maize is generally negative and spring wheat generally positive. Furthermore, when assuming CO2 fertilization effects to be negligible, we observe drastic climate mitigation policy as in RCP 2.6 could avoid more than 80% of the global average yield losses otherwise expected by the 2080s under RCP 8.5. We show large disparities in climate impacts across regions and find extreme heat stress adversely affects major producing regions and lower income countries.

  7. Future Extreme Heat Scenarios to Enable the Assessment of Climate Impacts on Public Health over the Coterminous U.S

    NASA Astrophysics Data System (ADS)

    Quattrochi, D. A.; Crosson, W. L.; Al-Hamdan, M. Z.; Estes, M. G., Jr.

    2013-12-01

    In the United States, extreme heat is the most deadly weather-related hazard. In the face of a warming climate and urbanization, which contributes to local-scale urban heat islands, it is very likely that extreme heat events (EHEs) will become more common and more severe in the U.S. This research seeks to provide historical and future measures of climate-driven extreme heat events to enable assessments of the impacts of heat on public health over the coterminous U.S. We use atmospheric temperature and humidity information from meteorological reanalysis and from Global Climate Models (GCMs) to provide data on past and future heat events. The focus of research is on providing assessments of the magnitude, frequency and geographic distribution of extreme heat in the U.S. to facilitate public health studies. In our approach, long-term climate change is captured with GCM outputs, and the temporal and spatial characteristics of short-term extremes are represented by the reanalysis data. Two future time horizons for 2040 and 2090 are compared to the recent past period of 1981-2000. We characterize regional-scale temperature and humidity conditions using GCM outputs for two climate change scenarios (A2 and A1B) defined in the Special Report on Emissions Scenarios (SRES). For each future period, 20 years of multi-model GCM outputs are analyzed to develop a ';heat stress climatology' based on statistics of extreme heat indicators. Differences between the two future and the past period are used to define temperature and humidity changes on a monthly time scale and regional spatial scale. These changes are combined with the historical meteorological data, which is hourly and at a spatial scale (12 km) much finer than that of GCMs, to create future climate realizations. From these realizations, we compute the daily heat stress measures and related spatially-specific climatological fields, such as the mean annual number of days above certain thresholds of maximum and minimum air

  8. Future Extreme Heat Scenarios to Enable the Assessment of Climate Impacts on Public Health over the Coterminous U.S.

    NASA Technical Reports Server (NTRS)

    Quattrochi, Dale A.; Crosson, William L.; Al-Hamdan, Mohammad Z.; Estes, Maurice G., Jr.

    2013-01-01

    In the United States, extreme heat is the most deadly weather-related hazard. In the face of a warming climate and urbanization, which contributes to local-scale urban heat islands, it is very likely that extreme heat events (EHEs) will become more common and more severe in the U.S. This research seeks to provide historical and future measures of climate-driven extreme heat events to enable assessments of the impacts of heat on public health over the coterminous U.S. We use atmospheric temperature and humidity information from meteorological reanalysis and from Global Climate Models (GCMs) to provide data on past and future heat events. The focus of research is on providing assessments of the magnitude, frequency and geographic distribution of extreme heat in the U.S. to facilitate public health studies. In our approach, long-term climate change is captured with GCM outputs, and the temporal and spatial characteristics of short-term extremes are represented by the reanalysis data. Two future time horizons for 2040 and 2090 are compared to the recent past period of 1981- 2000. We characterize regional-scale temperature and humidity conditions using GCM outputs for two climate change scenarios (A2 and A1B) defined in the Special Report on Emissions Scenarios (SRES). For each future period, 20 years of multi-model GCM outputs are analyzed to develop a 'heat stress climatology' based on statistics of extreme heat indicators. Differences between the two future and the past period are used to define temperature and humidity changes on a monthly time scale and regional spatial scale. These changes are combined with the historical meteorological data, which is hourly and at a spatial scale (12 km), to create future climate realizations. From these realizations, we compute the daily heat stress measures and related spatially-specific climatological fields, such as the mean annual number of days above certain thresholds of maximum and minimum air temperatures, heat indices

  9. The Weather of the Future: Heat Waves, Extreme Storms, and Other Scenes from a Climate-Changed Planet

    NASA Astrophysics Data System (ADS)

    Cullen, H. M.

    2010-12-01

    In The Weather of the Future, Dr. Heidi Cullen puts a vivid face on climate change, offering a new way of seeing this phenomenon not just as an event set to happen in the distant future but as something happening right now in our own backyards. Arguing that we must connect the weather of today with the climate change of tomorrow, Cullen combines the latest research from scientists on the ground with state-of-the-art climate model projections to create climate-change scenarios for seven of the most at-risk locations around the world. From the Central Valley of California, where coming droughts will jeopardize the entire state’s water supply, to Greenland, where warmer temperatures will give access to mineral wealth buried beneath ice sheets for millennia, Cullen illustrates how, if left unabated, climate change will transform every corner of the world by midcentury. What emerges is a mosaic of changing weather patterns that collectively spell out the range of risks posed by global warming—whether it’s New York City, whose infrastructure is extremely vulnerable even to a relatively weak Category 3 hurricane or to Bangladesh, a country so low-lying that millions of people could become climate refugees thanks to rising sea levels. The Weather of the Future makes climate change local, showing how no two regions of the country or the world will be affected in quite the same way and demonstrating that melting ice is just the beginning.

  10. Near future changes of extremes and compound extremes on the regional scale

    NASA Astrophysics Data System (ADS)

    Sedlmeier, Katrin; Feldmann, Hendrik; Schädler, Gerd

    2013-04-01

    Reliable knowledge of near future changes of extreme and compound extreme events on the regional scale is of great importance for impact studies and planning of adaptation/mitigation strategies. Different types of extremes might intensify each other, e.g. heat waves and droughts via evapotranspiration and heat flux. Compared to projections for the end of the century, the climate change and variation signals for the near future are weaker and more contaminated by to natural variations. On the other hand several studies (e.g. Feldmann et al. [1]) have shown that extremes are likely to undergo more pronounced changes than mean values. To derive reliable estimates of these changes, ensembles of simulations are a useful method since the larger number of data allows for a better estimate of probability density function parameters and higher signal-to-noise ratios which are especially needed for the analysis of extreme events and compound extremes. Furthermore, using ensembles enables an assessment of the uncertainty of the deduced changes. Our work is based on an ensemble of high resolution regional climate simulations with a resolution of 7 km with the COSMO-CLM regional climate model using different global driving data. Our ensemble is enlarged by results from the ENSEMBLES project, thus also including different regional and global driving models. Changes between a control period (1971-200) and the near future (2011-2040) are assessed with a special focus on central Europe. The analysis focuses on extreme events related to temperature and precipitation such as heat and cold waves or dry spells with a subsequent examination of compound extreme events. Compound extreme events are defined as the simultaneous or successive occurrence of two or more extreme events (IPCC Special Report on extreme events, 2012), e.g. the simultaneous occurrence of dry periods and heat waves or cold spells and extreme precipitation. Extremes are expressed in terms of return values and

  11. Summer Heat Waves - Extreme Years

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The performance of four heat stress indices was compared for response to known events. A 12-yr period of weather data was analyzed for occurrence of heat wave events at each of three locations--Grand Island and Concord, NE and Rockport, MO. Numerous events were detected at each location. The Temp...

  12. Keeping Cool in Extreme Heat

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Through a partnership with Unitika Ltd., NASA's Langley Research Center created a foam based on high temperature resistant polyimide chemistry. Licensed non-exclusively to SORDAL, Inc., the low-density foam, named TEEK, can be processed into forms or used to fill structures such as honeycomb. TEEK offers superior insulation and support qualities, with heat and flame resistance abilities.TEEK is a practical selection for hull insulation in the shipbuilding industry, with numerous potential applications in aerospace applications, fire-resistant construction materials, and a wide range of consumer products that will improve safety and energy efficiency. Other opportunities are available in the areas of automotive coatings and sealants, electrical components, and recreational equipment. SORDAL has introduced its new product in several different forms, under the name "SOLREX". The company is developing a new product called SORDAL Paper(TM) that will be used in conjunction with the polyimide foam to offer thermal protection in various products, such as fire resistant garments and prosthetics.

  13. Extreme Convective Weather in Future Decades

    NASA Astrophysics Data System (ADS)

    Gadian, Alan; Burton, Ralph; Groves, James; Blyth, Alan; Warner, James; Holland, Greg; Bruyere, Cindy; Done, James; Thielen, Jutta

    2016-04-01

    WISER (Weather Climate Change Impact Study at Extreme Resolution) is a project designed to analyse changes in extreme weather events in a future climate, using a weather model (WRF) which is able to resolve small scale processes. Use of a weather model is specifically designed to look at convection which is of a scale which cannot be resolved by climate models. The regional meso-scale precipitation events, which are critical in understanding climate change impacts will be analysed. A channel domain outer model, with a resolution of ~ 20km in the outer domain drives an inner domain of ~ 3 km resolution. Results from 1989-1994 and 2020-2024 and 2030-2034 will be presented to show the effects of extreme convective events over Western Europe. This presentation will provide details of the project. It will present data from the 1989-1994 ERA-interim and CCSM driven simulations, with analysis of the future years as defined above. The representation of pdfs of extreme precipitation, Outgoing Longwave Radiation and wind speeds, with preliminary comparison with observations will be discussed. It is also planned to use the output to drive the EFAS (European Flood model) to examine the predicted changes in quantity and frequency of severe and hazardous convective rainfall events and leading to the frequency of flash flooding due to heavy convective precipitation.

  14. Biological Extreme Events - Past, Present, and Future

    NASA Astrophysics Data System (ADS)

    Gutschick, V. P.

    2010-12-01

    Biological extreme events span wide ranges temporally and spatially and in type - population dieoffs, extinctions, ecological reorganizations, changes in biogeochemical fluxes, and more. Driving variables consist in meteorology, tectonics, orbital changes, anthropogenic changes (land-use change, species introductions, reactive N injection into the biosphere), and evolution (esp. of diseases). However, the mapping of extremes in the drivers onto biological extremes as organismal responses is complex, as laid out originally in the theoretical framework of Gutschick and BassiriRad (New Phytologist [2003] 100:21-42). Responses are nonlinear and dependent on (mostly unknown and) complex temporal sequences - often of multiple environmental variables. The responses are species- and genotype specific. I review extreme events over from past to present over wide temporal scales, while noting that they are not wholly informative of responses to the current and near-future drivers for at least two reasons: 1) the current combination of numerous environmental extremes - changes in CO2, temperature, precipitation, reactive N, land fragmentation, O3, etc. -is unprecedented in scope, and 2) adaptive genetic variation for organismal responses is constrained by poorly-characterized genetic structures (in organisms and populations) and by loss of genetic variation by genetic drift over long periods. We may expect radical reorganizations of ecosystem and biogeochemical functions. These changes include many ecosystem services in flood control, crop pollination and insect/disease control, C-water-mineral cycling, and more, as well as direct effects on human health. Predictions of such changes will necessarily be very weak in the critical next few decades, given the great deal of observation, experimentation, and theory construction that will be necessary, on both organisms and drivers. To make the research efforts most effective will require extensive, insightful planning, beginning

  15. Recent and future extreme precipitation over Ukraine

    NASA Astrophysics Data System (ADS)

    Vyshkvarkova, Olena; Voskresenskaya, Elena

    2014-05-01

    The aim of study is to analyze the parameters of precipitation extremes and inequality over Ukraine in recent climate epoch and their possible changes in the future. Data of observations from 28 hydrometeorological stations over Ukraine and output of GFDL-CM3 model (CMIP5) for XXI century were used in the study. The methods of concentration index (J. Martin-Vide, 2004) for the study of precipitation inequality while the extreme precipitation indices recommended by the ETCCDI - for the frequency of events. Results. Precipitation inequality on the annual and seasonal scales was studied using estimated CI series for 1951-2005. It was found that annual CI ranges vary from 0.58 to 0.64. They increase southward from the north-west (forest zone) and the north-east (forest steppe zone) of Ukraine. CI maxima are located in the coastal regions of the Black Sea and the Sea of Azov. Annual CI spatial distribution indicates that the contribution of extreme precipitation into annual totals is most significant at the boundary zone between steppe and marine regions. At the same time precipitation pattern at the foothill of Carpathian Mountains is more homogenous. The CI minima (0.54) are typical for the winter season in foothill of Ukrainian Carpathians. The CI maxima reach 0.71 in spring at the steppe zone closed to the Black Sea coast. It should be noted that the greatest ranges of CI maximum and CI minimum deviation are typical for spring. It is associated with patterns of cyclone trajectories in that season. The most territory is characterized by tendency to decrease the contribution of extreme precipitation into the total amount (CI linear trends are predominantly negative in all seasons). Decadal and interdecadal variability of precipitation inequality associated with global processes in ocean-atmosphere system are also studied. It was shown that precipitation inequality over Ukraine on 10 - 15 % stronger in negative phase of Pacific Decadal Oscillation and in positive phase

  16. Extreme heat changes post-heat wave community reassembly.

    PubMed

    Seifert, Linda I; Weithoff, Guntram; Vos, Matthijs

    2015-06-01

    Climate forecasts project further increases in extremely high-temperature events. These present threats to biodiversity, as they promote population declines and local species extinctions. This implies that ecological communities will need to rely more strongly on recovery processes, such as recolonization from a meta-community context. It is poorly understood how differences in extreme event intensity change the outcome of subsequent community reassembly and if such extremes modify the biotic environment in ways that would prevent the successful re-establishment of lost species. We studied replicated aquatic communities consisting of algae and herbivorous rotifers in a design that involved a control and two different heat wave intensity treatments (29°C and 39°C). Animal species that suffered heat-induced extinction were subsequently re-introduced at the same time and density, in each of the two treatments. The 39°C treatment led to community closure in all replicates, meaning that a previously successful herbivore species could not re-establish itself in the postheat wave community. In contrast, such closure never occurred after a 29°C event. Heat wave intensity determined the number of herbivore extinctions and strongly affected algal relative abundances. Re-introduced herbivore species were thus confronted with significantly different food environments. This ecological legacy generated by heat wave intensity led to differences in the failure or success of herbivore species re-introductions. Reassembly was significantly more variable, and hence less predictable, after an extreme heat wave, and was more canalized after a moderate one. Our results pertain to relatively simple communities, but they suggest that ecological legacies introduced by extremely high-temperature events may change subsequent ecological recovery and even prevent the successful re-establishment of lost species. Knowing the processes promoting and preventing ecological recovery is crucial

  17. Climate, extreme heat, and electricity demand in California

    SciTech Connect

    Miller, N.L.; Hayhoe, K.; Jin, J.; Auffhammer, M.

    2008-04-01

    Climate projections from three atmosphere-ocean climate models with a range of low to mid-high temperature sensitivity forced by the Intergovernmental Panel for Climate Change SRES higher, middle, and lower emission scenarios indicate that, over the 21st century, extreme heat events for major cities in heavily air-conditioned California will increase rapidly. These increases in temperature extremes are projected to exceed the rate of increase in mean temperature, along with increased variance. Extreme heat is defined here as the 90 percent exceedance probability (T90) of the local warmest summer days under the current climate. The number of extreme heat days in Los Angeles, where T90 is currently 95 F (32 C), may increase from 12 days to as many as 96 days per year by 2100, implying current-day heat wave conditions may last for the entire summer, with earlier onset. Overall, projected increases in extreme heat under the higher A1fi emission scenario by 2070-2099 tend to be 20-30 percent higher than those projected under the lower B1 emission scenario, ranging from approximately double the historical number of days for inland California cities (e.g. Sacramento and Fresno), up to four times for previously temperate coastal cities (e.g. Los Angeles, San Diego). These findings, combined with observed relationships between high temperature and electricity demand for air-conditioned regions, suggest potential shortfalls in transmission and supply during T90 peak electricity demand periods. When the projected extreme heat and peak demand for electricity are mapped onto current availability, maintaining technology and population constant only for demand side calculations, we find the potential for electricity deficits as high as 17 percent. Similar increases in extreme heat days are suggested for other locations across the U.S. southwest, as well as for developing nations with rapidly increasing electricity demands. Electricity response to recent extreme heat events, such

  18. Spatial vulnerability of Australian urban populations to extreme heat events

    NASA Astrophysics Data System (ADS)

    Loughnan, Margaret; Tapper, Nigel; Phan, Thu; Lynch, Kellie; McInnes, Judith

    2013-04-01

    Extreme heat events pose a risk to the health of all individuals, especially the elderly and the chronically ill, and are associated with an increased demand for healthcare services. In order to address this problem, policy makers' need information about temperatures above which mortality and morbidity of the exposed population is likely to increase, where the vulnerable groups in the community are located, and how the risks from extreme heat events are likely to change in the future. This study identified threshold temperatures for all Australian capital cities, developed a spatial index of population vulnerability, and used climate model output to predict changes in the number of days exceeding temperature thresholds in the future, as well as changes in risk related to changes in urban density and an ageing population. The study has shown that daily maximum and minimum temperatures from the Bureau of Meteorology forecasts can be used to calculate temperature thresholds for heat alert days. The key risk factors related to adverse health outcomes were found to be areas with intense urban heat islands, areas with higher proportions of older people, and areas with ethnic communities. Maps of spatial vulnerability have been developed to provide information to assist emergency managers, healthcare professionals, and ancillary services develop heatwave preparedness plans at a local scale that target vulnerable groups and address heat-related health risks. The numbers of days exceeding current heat thresholds are predicted to increase over the next 20 to 40 years in all Australian capital cities.

  19. Possible future changes in extreme events over Northern Eurasia

    NASA Astrophysics Data System (ADS)

    Monier, Erwan; Sokolov, Andrei; Scott, Jeffery

    2013-04-01

    In this study, we investigate possible future climate change over Northern Eurasia and its impact on extreme events. Northern Eurasia is a major player in the global carbon budget because of boreal forests and peatlands. Circumpolar boreal forests alone contain more than five times the amount of carbon of temperate forests and almost double the amount of carbon of the world's tropical forests. Furthermore, severe permafrost degradation associated with climate change could result in peatlands releasing large amounts of carbon dioxide and methane. Meanwhile, changes in the frequency and magnitude of extreme events, such as extreme precipitation, heat waves or frost days are likely to have substantial impacts on Northern Eurasia ecosystems. For this reason, it is very important to quantify the possible climate change over Northern Eurasia under different emissions scenarios, while accounting for the uncertainty in the climate response and changes in extreme events. For several decades, the Massachusetts Institute of Technology (MIT) Joint Program on the Science and Policy of Global Change has been investigating uncertainty in climate change using the MIT Integrated Global System Model (IGSM) framework, an integrated assessment model that couples an earth system model of intermediate complexity (with a 2D zonal-mean atmosphere) to a human activity model. In this study, regional change is investigated using the MIT IGSM-CAM framework that links the IGSM to the National Center for Atmospheric Research (NCAR) Community Atmosphere Model (CAM). New modules were developed and implemented in CAM to allow climate parameters to be changed to match those of the IGSM. The simulations presented in this paper were carried out for two emission scenarios, a "business as usual" scenario and a 660 ppm of CO2-equivalent stabilization, which are similar to, respectively, the Representative Concentration Pathways RCP8.5 and RCP4.5 scenarios. Values of climate sensitivity and net aerosol

  20. Seasonal mean temperature changes control future heat waves

    NASA Astrophysics Data System (ADS)

    Argüeso, Daniel; Di Luca, Alejandro; Perkins-Kirkpatrick, Sarah E.; Evans, Jason P.

    2016-07-01

    Increased temperature will result in longer, more frequent, and more intense heat waves. Changes in temperature variability have been deemed necessary to account for future heat wave characteristics. However, this has been quantified only in Europe and North America, while the rest of the globe remains unexplored. Using late century global climate projections, we show that annual mean temperature increases is the key factor defining heat wave changes in most regions. We find that commonly studied areas are an exception rather than the standard and the mean climate change signal generally outweighs any influence from variability changes. More importantly, differences in warming across seasons are responsible for most of the heat wave changes and their consideration relegates the contribution of variability to a marginal role. This reveals that accurately capturing mean seasonal changes is crucial to estimate future heat waves and reframes our interpretation of future temperature extremes.

  1. Future precipitation extremes during summer monsoon in southern Pakistan

    NASA Astrophysics Data System (ADS)

    Zahid, Maida; Lucarini, Valerio

    2016-04-01

    Extreme precipitation events are considered as a hydro-meteorological hazard resulting in colossal damage worldwide. In Pakistan, the extreme precipitation events have increased in the recent decades particularly in the southern part (Sindh province). This region did not receive substantial amount of precipitation earlier, but now experiencing urban flooding almost every year causing loss of life, property, crops and infrastructure. The region lacks the information regarding the recurrence of extreme precipitation events. Therefore, there is a strong need for a reliable information of extremes over the upcoming decades for better regional planning. Although statistical methods based on extreme value theory (EVT) are the most relevant ones to study the extremes, but they are never been applied in Pakistan. To address this shortcoming, we use the peak over threshold (POT) approach to compute the return levels (RLs) of precipitation extremes, and also identify the regions most prone to them. In this study, we analyzed the summer monsoon daily precipitation measured at nine weather stations of Pakistan Meteorological Department over the period 1980-2013. The summer monsoon (JJAS) is preferred for the analysis, because most of the extreme precipitation occurs during this period. We apply POT approach to model the daily precipitation above a selected threshold for each station. Then, we estimate return levels (RLs) of precipitation extremes during summer monsoon in southern Pakistan (Sindh) for the next 5, 25, 50 and 100-years. Lastly, we compare the 5-years with 100-years RLs to indicate the stations most vulnerable to precipitation extremes in future. This work is funded by the Climate KIC, European Institute of Innovation and Technology, Germany.

  2. Hypersonic Composites Resist Extreme Heat and Stress

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Through research contracts with NASA, Materials and Electrochemical Research Corporation (MER), of Tucson, Arizona, contributed a number of technologies to record-breaking hypersonic flights. Through this research, MER developed a coating that successfully passed testing to simulate Mach 10 conditions, as well as provide several additional carbon-carbon (C-C) composite components for the flights. MER created all of the leading edges for the X-43A test vehicles at Dryden-considered the most critical parts of this experimental craft. In addition to being very heat resistant, the coating had to be very lightweight and thin, as the aircraft was designed to very precise specifications and could not afford to have a bulky coating. MER patented its carbon-carbon (C-C) composite process and then formed a spinoff company, Frontier Materials Corporation (FMC), also based in Tucson. FMC is using the patent in conjunction with low-cost PAN (polyacrylonitrile)-based fibers to introduce these materials to the commercial markets. The C-C composites are very lightweight and exceptionally strong and stiff, even at very high temperatures. The composites have been used in industrial heating applications, the automotive and aerospace industries, as well as in glass manufacturing and on semiconductors. Applications also include transfer components for glass manufacturing and structural members for carrier support in semiconductor processing.

  3. Precipitation Extremes: Considerations for Anthropogenically-forced Future Changes

    NASA Astrophysics Data System (ADS)

    Kunkel, K.; Young, J.

    2015-12-01

    The Third National Climate Assessment states that "increases in the frequency and intensity of extreme precipitation events are projected for all U.S. regions". While that general statement was made with high confidence, the practical implications for decision-makers are much less clear. In particular, engineering design needs quantitative estimates of probable maximum precipitation (PMP) and intensity-duration-frequency (IDF) values for the future in order to optimize runoff control structures for future climate conditions. This can be realized by simply analyzing the precipitation data from global climate model simulations of the future. However, confidence in the resulting values suffers from the known issues with GCM simulation of precipitation. In addition, skepticism about the accuracy of climate models negatively affects potential adoption of revised values in the engineering design community. We contend that scientists need a multi-pronged approach to develop PMP/IDF values that can be defended, explained, and promoted in order to maximize societal benefits and avoid catastrophic events. This talk will discuss considerations that could/should form the basis for design values. While global-warming induced increases in atmospheric water vapor content are nearly certain and form the foundation for expected increases in extreme precipitation, they most likely will be modulated by changes in global atmospheric dynamics and the consequent effects on local weather system climatology. This can be seen currently in the unexplained regional variations in recent trends in extreme precipitation frequency and intensity. We need to be able to understand recent trends, when greenhouse gas forcing of the climate systems has been rapidly increasing, in order to produce confident projections of future extreme precipitation.

  4. Future Heat Waves in Paris Metropolitan Area

    NASA Astrophysics Data System (ADS)

    Beaulant, A.; Lemonsu, A.; Somot, S.; Masson, V.

    2010-12-01

    Cities are particularly vulnerable to heat waves, firstly because they concentrate the majority of the population and, secondly because the heat island that characterizes the urban climate exacerbates heat wave effects. This work is part of the interdisciplinary VURCA project (Vulnerability of cities to heat waves), which deals with the evolution of heat wave events in the context of global warming, urban vulnerability and adaptation strategies. The aim of this study is to analyse urban heat wave events in present climate (1950-2009) and their evolution in an enhanced greenhouse gazes future climate (2010-2100). We used daily observations of temperature from several stations covering Paris metropolitan area and climate projections following three different IPCC-SRES scenarios (B1, A1B, A2) and issued from several ENSEMBLES regional climate models. The heat wave definition is based on the indexes of the operational French warning system. A heat wave is detected within observed or simulated time-series by a heat wave peak, when the temperatures exceed the value of the 99.9th percentile. Its duration is determined by all adjacent days to this peak, for which the temperatures are not durably smaller than the 99.9th percentile value minus 2 °C. The 99.9th percentile threshold is inferred from quantile-quantile plots produced for each climate model in comparison with observations for the reference period 1950-2000. Heat waves have been extracted within observations and 12 climatic simulations. The number of heat wave events and cumulated HW days per year have been calculated, the maximum being seven heat waves cumulating more than 60 HW days in one year in the case of the A2 scenario and until 50 days in the case of the more moderate A1B scenario. From 2050, the occurrence of three or four HW events per year is becoming the norm all scenarios taken together. The evolution of heat wave features has been analysed, highlighting the large variability of the climatic

  5. Effects of climate extremes on the terrestrial carbon cycle: concepts, processes and potential future impacts.

    PubMed

    Frank, Dorothea; Reichstein, Markus; Bahn, Michael; Thonicke, Kirsten; Frank, David; Mahecha, Miguel D; Smith, Pete; van der Velde, Marijn; Vicca, Sara; Babst, Flurin; Beer, Christian; Buchmann, Nina; Canadell, Josep G; Ciais, Philippe; Cramer, Wolfgang; Ibrom, Andreas; Miglietta, Franco; Poulter, Ben; Rammig, Anja; Seneviratne, Sonia I; Walz, Ariane; Wattenbach, Martin; Zavala, Miguel A; Zscheischler, Jakob

    2015-08-01

    Extreme droughts, heat waves, frosts, precipitation, wind storms and other climate extremes may impact the structure, composition and functioning of terrestrial ecosystems, and thus carbon cycling and its feedbacks to the climate system. Yet, the interconnected avenues through which climate extremes drive ecological and physiological processes and alter the carbon balance are poorly understood. Here, we review the literature on carbon cycle relevant responses of ecosystems to extreme climatic events. Given that impacts of climate extremes are considered disturbances, we assume the respective general disturbance-induced mechanisms and processes to also operate in an extreme context. The paucity of well-defined studies currently renders a quantitative meta-analysis impossible, but permits us to develop a deductive framework for identifying the main mechanisms (and coupling thereof) through which climate extremes may act on the carbon cycle. We find that ecosystem responses can exceed the duration of the climate impacts via lagged effects on the carbon cycle. The expected regional impacts of future climate extremes will depend on changes in the probability and severity of their occurrence, on the compound effects and timing of different climate extremes, and on the vulnerability of each land-cover type modulated by management. Although processes and sensitivities differ among biomes, based on expert opinion, we expect forests to exhibit the largest net effect of extremes due to their large carbon pools and fluxes, potentially large indirect and lagged impacts, and long recovery time to regain previous stocks. At the global scale, we presume that droughts have the strongest and most widespread effects on terrestrial carbon cycling. Comparing impacts of climate extremes identified via remote sensing vs. ground-based observational case studies reveals that many regions in the (sub-)tropics are understudied. Hence, regional investigations are needed to allow a global

  6. Effects of climate extremes on the terrestrial carbon cycle: concepts, processes and potential future impacts

    PubMed Central

    Frank, Dorothea; Reichstein, Markus; Bahn, Michael; Thonicke, Kirsten; Frank, David; Mahecha, Miguel D; Smith, Pete; van der Velde, Marijn; Vicca, Sara; Babst, Flurin; Beer, Christian; Buchmann, Nina; Canadell, Josep G; Ciais, Philippe; Cramer, Wolfgang; Ibrom, Andreas; Miglietta, Franco; Poulter, Ben; Rammig, Anja; Seneviratne, Sonia I; Walz, Ariane; Wattenbach, Martin; Zavala, Miguel A; Zscheischler, Jakob

    2015-01-01

    Extreme droughts, heat waves, frosts, precipitation, wind storms and other climate extremes may impact the structure, composition and functioning of terrestrial ecosystems, and thus carbon cycling and its feedbacks to the climate system. Yet, the interconnected avenues through which climate extremes drive ecological and physiological processes and alter the carbon balance are poorly understood. Here, we review the literature on carbon cycle relevant responses of ecosystems to extreme climatic events. Given that impacts of climate extremes are considered disturbances, we assume the respective general disturbance-induced mechanisms and processes to also operate in an extreme context. The paucity of well-defined studies currently renders a quantitative meta-analysis impossible, but permits us to develop a deductive framework for identifying the main mechanisms (and coupling thereof) through which climate extremes may act on the carbon cycle. We find that ecosystem responses can exceed the duration of the climate impacts via lagged effects on the carbon cycle. The expected regional impacts of future climate extremes will depend on changes in the probability and severity of their occurrence, on the compound effects and timing of different climate extremes, and on the vulnerability of each land-cover type modulated by management. Although processes and sensitivities differ among biomes, based on expert opinion, we expect forests to exhibit the largest net effect of extremes due to their large carbon pools and fluxes, potentially large indirect and lagged impacts, and long recovery time to regain previous stocks. At the global scale, we presume that droughts have the strongest and most widespread effects on terrestrial carbon cycling. Comparing impacts of climate extremes identified via remote sensing vs. ground-based observational case studies reveals that many regions in the (sub-)tropics are understudied. Hence, regional investigations are needed to allow a global

  7. Radiative heat transfer in the extreme near field.

    PubMed

    Kim, Kyeongtae; Song, Bai; Fernández-Hurtado, Víctor; Lee, Woochul; Jeong, Wonho; Cui, Longji; Thompson, Dakotah; Feist, Johannes; Reid, M T Homer; García-Vidal, Francisco J; Cuevas, Juan Carlos; Meyhofer, Edgar; Reddy, Pramod

    2015-12-17

    Radiative transfer of energy at the nanometre length scale is of great importance to a variety of technologies including heat-assisted magnetic recording, near-field thermophotovoltaics and lithography. Although experimental advances have enabled elucidation of near-field radiative heat transfer in gaps as small as 20-30 nanometres (refs 4-6), quantitative analysis in the extreme near field (less than 10 nanometres) has been greatly limited by experimental challenges. Moreover, the results of pioneering measurements differed from theoretical predictions by orders of magnitude. Here we use custom-fabricated scanning probes with embedded thermocouples, in conjunction with new microdevices capable of periodic temperature modulation, to measure radiative heat transfer down to gaps as small as two nanometres. For our experiments we deposited suitably chosen metal or dielectric layers on the scanning probes and microdevices, enabling direct study of extreme near-field radiation between silica-silica, silicon nitride-silicon nitride and gold-gold surfaces to reveal marked, gap-size-dependent enhancements of radiative heat transfer. Furthermore, our state-of-the-art calculations of radiative heat transfer, performed within the theoretical framework of fluctuational electrodynamics, are in excellent agreement with our experimental results, providing unambiguous evidence that confirms the validity of this theory for modelling radiative heat transfer in gaps as small as a few nanometres. This work lays the foundations required for the rational design of novel technologies that leverage nanoscale radiative heat transfer. PMID:26641312

  8. Rapid increase in the risk of extreme summer heat in Eastern China

    NASA Astrophysics Data System (ADS)

    Sun, Ying; Zhang, Xuebin; Zwiers, Francis W.; Song, Lianchun; Wan, Hui; Hu, Ting; Yin, Hong; Ren, Guoyu

    2014-12-01

    The summer of 2013 was the hottest on record in Eastern China. Severe extended heatwaves affected the most populous and economically developed part of China and caused substantial economic and societal impacts. The estimated direct economic losses from the accompanying drought alone total 59 billion RMB (ref. ). Summer (June-August) mean temperature in the region has increased by 0.82 °C since reliable observations were established in the 1950s, with the five hottest summers all occurring in the twenty-first century. It is challenging to attribute extreme events to causes. Nevertheless, quantifying the causes of such extreme summer heat and projecting its future likelihood is necessary to develop climate adaptation strategies. We estimate that anthropogenic influence has caused a more than 60-fold increase in the likelihood of the extreme warm 2013 summer since the early 1950s, and project that similarly hot summers will become even more frequent in the future, with fully 50% of summers being hotter than the 2013 summer in two decades even under the moderate RCP4.5 emissions scenario. Without adaptation to reduce vulnerability to the effects of extreme heat, this would imply a rapid increase in risks from extreme summer heat to Eastern China.

  9. Current and future U.S. weather extremes and El Niño

    NASA Astrophysics Data System (ADS)

    Meehl, Gerald A.; Tebaldi, Claudia; Teng, Haiyan; Peterson, Thomas C.

    2007-10-01

    A global coupled climate model representative of the current generation of models is shown to simulate most first order aspects of El Niño events, their teleconnections over North America, and the associated observed patterns of extremes in present-day climate. Future El Niño teleconnection patterns over the U.S. are projected to shift eastward and northward due in part to the different midlatitude base state atmospheric circulation in a warmer climate. Consequently, projections for the changes in the patterns of extremes over the U.S. during future El Niño events include: decreases of frost days over the southwestern U.S expand northward and eastward; increases in intense precipitation in the SW U.S. expands eastward and areas in the SE U.S. become stronger; and decreases of heat wave intensity over much of the southern tier of states turn to increases.

  10. Historical warnings of future food insecurity with unprecedented seasonal heat.

    PubMed

    Battisti, David S; Naylor, Rosamond L

    2009-01-01

    Higher growing season temperatures can have dramatic impacts on agricultural productivity, farm incomes, and food security. We used observational data and output from 23 global climate models to show a high probability (>90%) that growing season temperatures in the tropics and subtropics by the end of the 21st century will exceed the most extreme seasonal temperatures recorded from 1900 to 2006. In temperate regions, the hottest seasons on record will represent the future norm in many locations. We used historical examples to illustrate the magnitude of damage to food systems caused by extreme seasonal heat and show that these short-run events could become long-term trends without sufficient investments in adaptation. PMID:19131626

  11. Enceladus' extreme heat flux as revealed by its relaxed craters

    NASA Astrophysics Data System (ADS)

    Bland, Michael T.; Singer, Kelsi N.; McKinnon, William B.; Schenk, Paul M.

    2012-09-01

    Enceladus' cratered terrains contain large numbers of unusually shallow craters consistent with deformation by viscous relaxation of water ice under conditions of elevated heat flow. Here we use high-resolution topography to measure the relaxation fraction of craters on Enceladus far from the active South Pole. We find that many craters are shallower than expected, with craters as small as 2 km in diameter having relaxation fractions in excess of 90%. These measurements are compared with numerical simulations of crater relaxation to constrain the minimum heat flux required to reproduce these observations. We find that Enceladus' nominal cold surface temperature (70 K) and low surface gravity strongly inhibit viscous relaxation. Under such conditions less than 3% relaxation occurs over 2 Ga even for relatively large craters (diameter 24 km) and high, constant heat fluxes (150 mW m-2). Greater viscous relaxation occurs if the effective temperature at the top of the lithosphere is greater than the surface temperature due to insulating regolith and/or plume material. Even for an effective temperature of 120 K, however, heat fluxes in excess of 150 mW m-2 are required to produce the degree of relaxation observed. Simulations of viscous relaxation of Enceladus' largest craters suggest that relaxation is best explained by a relatively short-lived period of intense heating that decayed quickly. We show that infilling of craters by plume material cannot explain the extremely shallow craters at equatorial and higher northern latitudes. Thus, like Enceladus' tectonic terrains, the cratered regions of Enceladus have experienced periods of extreme heat flux.

  12. Future climate projections of extreme precipitation and temperature distributions by using an Extreme Value Theory non-stationary model

    NASA Astrophysics Data System (ADS)

    Casati, B.; Lefaivre, L.

    2009-04-01

    Extreme weather events can cause large damages and losses, and have high societal and economical impacts. Climate model integrations predict increases in both frequency and intensity of extreme events under enhanced greenhouse conditions. Better understanding of the capabilities of climate models in representing the present climate extremes, joint with the analysis of the future climate projections for extreme events, can help to forewarn society from future high-impact events, and possibly better develop adaptation strategies. Extreme Value Theory (EVT) provides a well established and robust framework to analyse the behaviour of extreme weather events for the present climate and future projections. In this study a non-stationary model for Generalised Extreme Value (GEV) distributions is used to analyse the trend of the distributions of extreme precipitation and temperatures, in the context of a changing climate. The analysis is performed for the climate projections of the Canadian Regional Climate Model (CRCM), under a SRES A2 emission scenario, for annual, seasonal and monthly extremes, for 12 regions characterised by different climatologies over the North American domain. Significant positive trends for the location of the distributions are found in most regions, indicating an expected increase in extreme value intensities, whereas the scale (variability) and shape (tail values) of the extreme distributions seem not to vary significantly. Extreme events, such as intense convective precipitation, are often associated to small-scale features. The enhanced resolution of Regional Climate Models enables to better represent such extreme events, with respect to Global Climate Models. However the resolution of these models is sometimes still too coarse to reproduce realistic extremes. To address this representativeness issue, statistical downscaling of the CRCM projections is performed. The downscaling relation is obtained by comparing the GEV distributions for the CRCM

  13. Temporal & Spatial Distribution of Extreme Heat Event in NYC Metro-Area

    NASA Astrophysics Data System (ADS)

    Alvi, M. N.

    2012-12-01

    Recent studies indicate an increase in extreme summer weather events that may be linked to global warming. Heat wave intensity and frequency trends are a relatively unexplored topic that may demonstrate a more pronounced global warming manifestation than general climate change. Extreme heat events have adverse effects on both, ecosystems and human health, killing over 70,000 in 2003 alone. This study aims to validate that extreme heat events have been increasing in intensity, frequency, duration and affected-area over the past 40 years. The importance of properly defining heat events is stressed. As there is no exact definition, this study uses the adjusted NOAA National Weather Service definition, in terms of heat index, a reference to human comfort as defined by temperature and humidity. A heat wave is defined when maximum outside conditions of human comfort levels are present for consecutive days. Complex cities such as New York (NYC) are also expected to experience more intense heat events when considering the Urban Heat Island Effect. To observe the extent of recent heat events in NYC, heat event trends were produced using data from up to 59 NYCMetNet surface weather stations covering all five boroughs of the City. Map comparisons of heat events from recent years (2010-2012) demonstrate an increase in the effected metro areas with concentrated maximums in the northwest part of the city, attributed to the dense urban landscape and a converging wind zone. To investigate temporal trends of heat waves in NYC, four NOAA-NCDC weather stations in the NYC Metro Area were used, providing data from 1973-2012. The time series results indicate that heat wave maximum intensities are increasing in NYC as a function of time since 1973 at a rate of 1.2°C/decade. The temporal plots demonstrate an annual increase in maximum intensity, frequency, and average event duration that could be attributed to increasing heat island and global warming. Future studies will expand this

  14. Simulating future precipitation extremes in a complex Alpine catchment

    NASA Astrophysics Data System (ADS)

    Dobler, C.; Bürger, G.; Stötter, J.

    2013-02-01

    The objectives of the present investigation are (i) to study the effects of climate change on precipitation extremes and (ii) to assess the uncertainty in the climate projections. The investigation is performed on the Lech catchment, located in the Northern Limestone Alps. In order to estimate the uncertainty in the climate projections, two statistical downscaling models as well as a number of global and regional climate models were considered. The downscaling models applied are the Expanded Downscaling (XDS) technique and the Long Ashton Research Station Weather Generator (LARS-WG). The XDS model, which is driven by analyzed or simulated large-scale synoptic fields, has been calibrated using ECMWF-interim reanalysis data and local station data. LARS-WG is controlled through stochastic parameters representing local precipitation variability, which are calibrated from station data only. Changes in precipitation mean and variability as simulated by climate models were then used to perturb the parameters of LARS-WG in order to generate climate change scenarios. In our study we use climate simulations based on the A1B emission scenario. The results show that both downscaling models perform well in reproducing observed precipitation extremes. In general, the results demonstrate that the projections are highly variable. The choice of both the GCM and the downscaling method are found to be essential sources of uncertainty. For spring and autumn, a slight tendency toward an increase in the intensity of future precipitation extremes is obtained, as a number of simulations show statistically significant increases in the intensity of 90th and 99th percentiles of precipitation on wet days as well as the 5- and 20-yr return values.

  15. Techniques that Link Extreme Events to the Large Scale, Applied to California Heat Waves

    NASA Astrophysics Data System (ADS)

    Grotjahn, R.

    2015-12-01

    Understanding the mechanisms how Californian Central Valley (CCV) summer extreme hot spells develop is very important since the events have major impacts on the economy and human safety. Results from a series of CCV heat wave studies will be presented, emphasizing the techniques used. Key larger scale elements are identified statistically that are also consistent with synoptic and dynamic understanding of what must be present during extreme heat. Beyond providing a clear synoptic explanation, these key elements have high predictability, in part because soil moisture has little annual variation in the heavily-irrigated CCV. In turn, the predictability naturally leads to an effective tool to assess climate model simulation of these heat waves in historical and future climate scenarios. (Does the model develop extreme heat for the correct reasons?) Further work identified that these large scale elements arise in two quite different ways: one from expansion southwestward of a pre-existing heat wave in southwest Canada, the other formed in place from parcels traversing the North Pacific. The pre-existing heat wave explains an early result showing correlation between heat waves in Sacramento California, and other locations along the US west coast, including distant Seattle Washington. CCV heat waves can be preceded by unusually strong tropical Indian Ocean and Indonesian convection, this partial link may occur through an Asian subtropical jet wave guide. Another link revealed by diagnostics is a middle and higher latitude source of wave activity in Siberia and East Asia that also leads to the development of the CCV heat wave. This talk will address as many of these results and the tools used to obtain them as is reasonable within the available time.

  16. Assessing the impact of future climate extremes on the US corn and soybean production

    NASA Astrophysics Data System (ADS)

    Jin, Z.

    2015-12-01

    Future climate changes will place big challenges to the US agricultural system, among which increasing heat stress and precipitation variability were the two major concerns. Reliable prediction of crop productions in response to the increasingly frequent and severe extreme climate is a prerequisite for developing adaptive strategies on agricultural risk management. However, the progress has been slow on quantifying the uncertainty of computational predictions at high spatial resolutions. Here we assessed the risks of future climate extremes on the US corn and soybean production using the Agricultural Production System sIMulator (APSIM) model under different climate scenarios. To quantify the uncertainty due to conceptual representations of heat, drought and flooding stress in crop models, we proposed a new strategy of algorithm ensemble in which different methods for simulating crop responses to those extreme climatic events were incorporated into the APSIM. This strategy allowed us to isolate irrelevant structure differences among existing crop models but only focus on the process of interest. Future climate inputs were derived from high-spatial-resolution (12km × 12km) Weather Research and Forecasting (WRF) simulations under Representative Concentration Pathways 4.5 (RCP 4.5) and 8.5 (RCP 8.5). Based on crop model simulations, we analyzed the magnitude and frequency of heat, drought and flooding stress for the 21st century. We also evaluated the water use efficiency and water deficit on regional scales if farmers were to boost their yield by applying more fertilizers. Finally we proposed spatially explicit adaptation strategies of irrigation and fertilizing for different management zones.

  17. Hot bats: extreme thermal tolerance in a desert heat wave.

    PubMed

    Bondarenco, Artiom; Körtner, Gerhard; Geiser, Fritz

    2014-08-01

    Climate change is predicted to increase temperature extremes and thus thermal stress on organisms. Animals living in hot deserts are already exposed to high ambient temperatures (T a) making them especially vulnerable to further warming. However, little is known about the effect of extreme heat events on small desert mammals, especially tree-roosting microbats that are not strongly protected from environmental temperature fluctuations. During a heat wave with record T as at Sturt National Park, we quantified the thermal physiology and behaviour of a single free-ranging little broad-nosed (Scotorepens greyii, henceforth Scotorepens) and two inland freetail bats (Mormopterus species 3, henceforth Mormopterus) using temperature telemetry over 3 days. On 11 and 13 January, maximum T a was ∼45.0 °C, and all monitored bats were thermoconforming. On 12 January 2013, when T a exceeded 48.0 °C, Scotorepens abandoned its poorly insulated roost during the daytime, whereas both Mormopterus remained in their better insulated roosts and were mostly thermoconforming. Maximum skin temperatures (T skin) ranged from 44.0 to 44.3 °C in Scotorepens and from 40.0 to 45.8 °C in Mormopterus, and these are the highest T skin values reported for any free-ranging bat. Our study provides the first evidence of extensive heat tolerance in free-ranging desert microbats. It shows that these bats can tolerate the most extreme T skin range known for mammals (3.3 to 45.8 °C) and delay regulation of T skin by thermoconforming over a wide temperature range and thus decrease the risks of dehydration and consequently death. PMID:25005222

  18. Hot bats: extreme thermal tolerance in a desert heat wave

    NASA Astrophysics Data System (ADS)

    Bondarenco, Artiom; Körtner, Gerhard; Geiser, Fritz

    2014-08-01

    Climate change is predicted to increase temperature extremes and thus thermal stress on organisms. Animals living in hot deserts are already exposed to high ambient temperatures ( T a) making them especially vulnerable to further warming. However, little is known about the effect of extreme heat events on small desert mammals, especially tree-roosting microbats that are not strongly protected from environmental temperature fluctuations. During a heat wave with record T as at Sturt National Park, we quantified the thermal physiology and behaviour of a single free-ranging little broad-nosed ( Scotorepens greyii, henceforth Scotorepens) and two inland freetail bats ( Mormopterus species 3, henceforth Mormopterus) using temperature telemetry over 3 days. On 11 and 13 January, maximum T a was ˜45.0 °C, and all monitored bats were thermoconforming. On 12 January 2013, when T a exceeded 48.0 °C, Scotorepens abandoned its poorly insulated roost during the daytime, whereas both Mormopterus remained in their better insulated roosts and were mostly thermoconforming. Maximum skin temperatures ( T skin) ranged from 44.0 to 44.3 °C in Scotorepens and from 40.0 to 45.8 °C in Mormopterus, and these are the highest T skin values reported for any free-ranging bat. Our study provides the first evidence of extensive heat tolerance in free-ranging desert microbats. It shows that these bats can tolerate the most extreme T skin range known for mammals (3.3 to 45.8 °C) and delay regulation of T skin by thermoconforming over a wide temperature range and thus decrease the risks of dehydration and consequently death.

  19. Population exposure to heat-related extremes: Demographic change vs climate change

    NASA Astrophysics Data System (ADS)

    Jones, B.; O'Neill, B. C.; Tebaldi, C.; Oleson, K. W.

    2014-12-01

    Extreme heat events are projected to increase in frequency and intensity in the coming decades [1]. The physical effects of extreme heat on human populations are well-documented, and anticipating changes in future exposure to extreme heat is a key component of adequate planning/mitigation [2, 3]. Exposure to extreme heat depends not only on changing climate, but also on changes in the size and spatial distribution of the human population. Here we focus on systematically quantifying exposure to extreme heat as a function of both climate and population change. We compare exposure outcomes across multiple global climate and spatial population scenarios, and characterize the relative contributions of each to population exposure to extreme heat. We consider a 2 x 2 matrix of climate and population output, using projections of heat extremes corresponding to RCP 4.5 and RCP 8.5 from the NCAR community land model, and spatial population projections for SSP 3 and SSP 5 from the NCAR spatial population downscaling model. Our primary comparison is across RCPs - exposure outcomes from RCP 4.5 versus RCP 8.5 - paying particular attention to how variation depends on the choice of SSP in terms of aggregate global and regional exposure, as well as the spatial distribution of exposure. We assess how aggregate exposure changes based on the choice of SSP, and which driver is more important, population or climate change (i.e. does that outcome vary more as a result of RCP or SSP). We further decompose the population component to analyze the contributions of total population change, migration, and changes in local spatial structure. Preliminary results from a similar study of the US suggests a four-to-six fold increase in total exposure by the latter half of the 21st century. Changes in population are as important as changes in climate in driving this outcome, and there is regional variation in the relative importance of each. Aggregate population growth, as well as redistribution of

  20. A Cross-Sectional, Randomized Cluster Sample Survey of Household Vulnerability to Extreme Heat among Slum Dwellers in Ahmedabad, India

    PubMed Central

    Tran, Kathy V.; Azhar, Gulrez S.; Nair, Rajesh; Knowlton, Kim; Jaiswal, Anjali; Sheffield, Perry; Mavalankar, Dileep; Hess, Jeremy

    2013-01-01

    Extreme heat is a significant public health concern in India; extreme heat hazards are projected to increase in frequency and severity with climate change. Few of the factors driving population heat vulnerability are documented, though poverty is a presumed risk factor. To facilitate public health preparedness, an assessment of factors affecting vulnerability among slum dwellers was conducted in summer 2011 in Ahmedabad, Gujarat, India. Indicators of heat exposure, susceptibility to heat illness, and adaptive capacity, all of which feed into heat vulnerability, was assessed through a cross-sectional household survey using randomized multistage cluster sampling. Associations between heat-related morbidity and vulnerability factors were identified using multivariate logistic regression with generalized estimating equations to account for clustering effects. Age, preexisting medical conditions, work location, and access to health information and resources were associated with self-reported heat illness. Several of these variables were unique to this study. As sociodemographics, occupational heat exposure, and access to resources were shown to increase vulnerability, future interventions (e.g., health education) might target specific populations among Ahmedabad urban slum dwellers to reduce vulnerability to extreme heat. Surveillance and evaluations of future interventions may also be worthwhile. PMID:23778061

  1. Extreme Hot Days future projections using Circulation Types

    NASA Astrophysics Data System (ADS)

    Andres Garcia-Valero, Juan; Fernández-Montes, Sonia; Jerez, Sonia; Montávez, Juan Pedro; Gómez-Navarro, Juan Jose

    2016-04-01

    This work presents an ensemble of future climate change projections of Extreme Hot Days (EHDs) for Spain. EHD are defined as the days with temperature over the 95 percentile of extended 8 summer regional series (Garcia-Valero et al, 2015). The ensemble consist of 18 members. These come from varying the RPC (4.5 and 8.5), the global model (MPIM,EC-EARTH, CCSM) and the Circulation Type (CT) classification (Z500-SLP, Z500-T850, SLP-T850) obtained in Garcia-Valero et al (2015). Firstly, the ability of GCMs for representing the observed extreme CTs in the historical runs is assessed. All models represent satisfactory most CTs for all classifications, being the bias errors of the frequency appearance of the CTs always under the 15%. Results indicate that the CTs having the largest efficiencies in EHD production has the biggest increase along the next century. This leads to that all regions strongly increase the frequency appearance of EHD. The EHD increase is larger in the inner regions towards the north of Spain, reaching an increase of 3 times the current frequency at the end of this century . This shift is mainly attributable to changes in the atmospheric dynamics. It is very likely that the this value is a low boundary of EHD positive change, since most regional processes (feedbacks, persistence, etc) tends to increase high temperature events. In addition, an analysis of uncertainties has been carried out. An ANOVA analysis shows that the uncertainty associated to each source (GCMs, CT-class, RPC) depends on the region. However the general behavior is that the largest uncertainty is assigned to the GCM, while RCP and CT-class presents similar uncertainty.

  2. [Sports and extreme conditions. Cardiovascular incidence in long term exertion and extreme temperatures (heat, cold)].

    PubMed

    Melin, B; Savourey, G

    2001-06-30

    During ultra-endurance exercise, both increase in body temperature and dehydration due to sweat losses, lead to a decrease in central blood volume. The heart rate drift allows maintaining appropriate cardiac output, in order to satisfy both muscle perfusion and heat transfer requirements by increasing skin blood flow. The resulting dehydration can impair thermal regulation and increase the risks of serious accidents as heat stroke. Endurance events, lasting more than 8 hours, result in large sweat sodium chloride losses. Thus, ingestion of large amounts of water with poor salt intake can induce symptomatic hyponatremia (plasma sodium < 130 mEq/L) which is also a serious accident. Heat environment increases the thermal constraint and when the air humidity is high, evaporation of sweat is compromise. Thus, thermal stress becomes uncompensable which increases the risk of cardiovascular collapse. Cold exposure induces physiological responses to maintain internal temperature by both limiting thermal losses and increasing metabolic heat production. Cold can induce accidental hypothermia and local frost-bites; moreover, it increases the risk of arrhythmia during exercise. Some guidelines (cardiovascular fitness, water and electrolyte intakes, protective clothing) are given for each extreme condition. PMID:11505864

  3. Responses of tree species to heat waves and extreme heat events.

    PubMed

    Teskey, Robert; Wertin, Timothy; Bauweraerts, Ingvar; Ameye, Maarten; McGuire, Mary Anne; Steppe, Kathy

    2015-09-01

    The number and intensity of heat waves has increased, and this trend is likely to continue throughout the 21st century. Often, heat waves are accompanied by drought conditions. It is projected that the global land area experiencing heat waves will double by 2020, and quadruple by 2040. Extreme heat events can impact a wide variety of tree functions. At the leaf level, photosynthesis is reduced, photooxidative stress increases, leaves abscise and the growth rate of remaining leaves decreases. In some species, stomatal conductance increases at high temperatures, which may be a mechanism for leaf cooling. At the whole plant level, heat stress can decrease growth and shift biomass allocation. When drought stress accompanies heat waves, the negative effects of heat stress are exacerbated and can lead to tree mortality. However, some species exhibit remarkable tolerance to thermal stress. Responses include changes that minimize stress on photosynthesis and reductions in dark respiration. Although there have been few studies to date, there is evidence of within-species genetic variation in thermal tolerance, which could be important to exploit in production forestry systems. Understanding the mechanisms of differing tree responses to extreme temperature events may be critically important for understanding how tree species will be affected by climate change. PMID:25065257

  4. Carbon cycle extremes during the 21st century in CMIP5 models: Future evolution and attribution to climatic drivers

    NASA Astrophysics Data System (ADS)

    Zscheischler, Jakob; Reichstein, Markus; von Buttlar, Jannis; Mu, Mingquan; Randerson, James T.; Mahecha, Miguel D.

    2014-12-01

    Climate extremes such as droughts and heat waves affect terrestrial ecosystems and may alter local carbon budgets. However, it still remains uncertain to what degree extreme impacts in the carbon cycle influence the carbon cycle-climate feedback both today and the near future. Here we analyze spatiotemporally contiguous negative extreme anomalies in gross primary production (GPP) and net ecosystem production (NEP) in model output of the Coupled Model Intercomparison Project Phase 5 (CMIP5) ensemble and investigate their future development and attribution to climatic drivers. We find that relative to the overall increase in global carbon uptake, negative extremes in GPP and NEP lose importance toward the end of the 21st century. This effect can be related to elevated CO2 concentrations and higher amounts of available water at the global scale, partially mitigating the impacts of droughts and heat waves, respectively. Overall, based on CMIP5 models, we hypothesize that terrestrial ecosystems might be more resilient against future climate extremes than previously thought. Future work will have to further scrutinize these results considering that various biological and biogeochemical feedbacks are not yet integrated within Earth system models.

  5. Extreme Rivers for Future Climates - Simulation Using Spatial Weather Generator

    NASA Astrophysics Data System (ADS)

    Kuchar, Leszek; Kosierb, Ryszard; Iwański, Sławomir; Jelonek, Leszek

    2014-05-01

    In this paper an application of spatial weather generator for estimation of probability distributions changes of river flows for selected climate change scenarios and different time horizons are presented. The main studies for the Kaczawa river basin located in Southwest region of Poland are carried out. For the estimation of probability distribution river flow, daily data of SR solar radiation, maximum and minimum air temperature, and total precipitation were obtained for sixteen stations of hydrological network from Institute of Meteorology and Water Management. In addition, daily data of flows from 6 closing water-gauges (partial catchments) were collected. Idea of flow simulation in the Kaczawa river catchment for future climate conditions given by different scenario shall be presented in the paper. First, on the basis of 25-years data series (1981-2005) for 16 stations of meteorological network within or around the Kaczawa river catchment basic climatology characteristics required by weather generator are computed. Then, spatial correlations between variables and stations are added to the characteristics. Next, on the basis of information coming from three climate change scenarios (GISS, GFDL and CCCM) for years 2040, 2060 and 2080 basic climatology characteristics are modified. Then, spatial weather generator SWGEN is used to produce 500 years of synthetic data for 16 stations, given time horizon and scenario. The year 2000 as the background of potential changes in river flow is used together with 500 years of synthetic data. Next, generated data are applied to hydrological model Mike SHE to simulate daily flows for closing water-gauges. The flow are evaluated with different temporal step and characterized by pdf functions. The application of spatial weather generator SWGEN combined with hydrological rainfall-runoff model (Mike SHE Ed. 2008) and climate change scenario, gives various possibilities to study changes in the river catchment coming up to 60

  6. Climate extremes and climate change: The Russian heat wave and other climate extremes of 2010

    NASA Astrophysics Data System (ADS)

    Trenberth, Kevin E.; Fasullo, John T.

    2012-09-01

    A global perspective is developed on a number of high impact climate extremes in 2010 through diagnostic studies of the anomalies, diabatic heating, and global energy and water cycles that demonstrate relationships among variables and across events. Natural variability, especially ENSO, and global warming from human influences together resulted in very high sea surface temperatures (SSTs) in several places that played a vital role in subsequent developments. Record high SSTs in the Northern Indian Ocean in May 2010, the Gulf of Mexico in August 2010, the Caribbean in September 2010, and north of Australia in December 2010 provided a source of unusually abundant atmospheric moisture for nearby monsoon rains and flooding in Pakistan, Colombia, and Queensland. The resulting anomalous diabatic heating in the northern Indian and tropical Atlantic Oceans altered the atmospheric circulation by forcing quasi-stationary Rossby waves and altering monsoons. The anomalous monsoonal circulations had direct links to higher latitudes: from Southeast Asia to southern Russia, and from Colombia to Brazil. Strong convection in the tropical Atlantic in northern summer 2010 was associated with a Rossby wave train that extended into Europe creating anomalous cyclonic conditions over the Mediterranean area while normal anticyclonic conditions shifted downstream where they likely interacted with an anomalously strong monsoon circulation, helping to support the persistent atmospheric anticyclonic regime over Russia. This set the stage for the "blocking" anticyclone and associated Russian heat wave and wild fires. Attribution is limited by shortcomings in models in replicating monsoons, teleconnections and blocking.

  7. Solar extreme ultraviolet irradiance: Present, past, and future

    NASA Astrophysics Data System (ADS)

    Lean, J. L.; Woods, T. N.; Eparvier, F. G.; Meier, R. R.; Strickland, D. J.; Correira, J. T.; Evans, J. S.

    2011-01-01

    New models of solar extreme ultraviolet (EUV) irradiance variability are constructed in 1 nm bins from 0 to 120 nm using multiple regression of the Mg II and F10.7 solar activity indices with irradiance observations made during the descending phase of cycle 23. The models have been used to reconstruct EUV spectra daily since 1950, annually since 1610, to forecast daily EUV irradiance and to estimate future levels in cycle 24. A two-component model developed by scaling the observed rotational modulation of the two solar indices underestimates the solar cycle changes that the Solar EUV Experiment (SEE) reports at wavelengths shorter than 40 nm and longer than 80 nm. A three-component model implemented by including an additional term derived from the smoothed Mg II index better reproduces the measurements at all wavelengths. The three-component model is consistent with variations in the EUV energy from 0 to 45 nm that produces the far ultraviolet (FUV) terrestrial dayglow observed by the Global Ultraviolet Imager (GUVI). However, the spectral structure of this third component is complex, and its origin is uncertain. Analogous two- and three-component models are also developed with absolute scales determined by the NRLEUV2 spectrum of the quiet Sun rather than by the SEE average spectrum. Assessment of the EUV absolute spectrum and variability of the four different models indicate that during solar cycle 23, the EUV irradiance (0 to 120 nm) increased 100 ± 30%, from 2.9 ± 0.2 to 5.8 ± 0.9 mWm-2, and may have been as low as 1.9 ± 0.5 mWm-2 during the 17th-century Maunder Minimum. Near the peak of upcoming solar cycle 24, EUV irradiance is expected to increase 40% to 80% above the 2008 minimum values.

  8. Urban Heat Island phenomenon in extreme continental climate (Astana, Kazakhstan)

    NASA Astrophysics Data System (ADS)

    Konstantinov, Pavel; Akhmetova, Alina

    2015-04-01

    Urban Heat Island (UHI) phenomenon is well known in scientific literature since first half of the 19th century [1]. By now a wide number of world capitals is described from climatological point of view, especially in mid-latitudes. In beginning of XXI century new studies focus on heat island of tropical cities. However dynamics UHI in extreme continental climates is insufficiently investigated, due to the fact that there isn't large cities in Europe and Northern America within that climate type. In this paper we investigate seasonal and diurnal dynamics UHI intensity for Astana, capital city of Kazakhstan (population larger than 835 000 within the city) including UHI intensity changes on different time scales. Now (since 1998) Astana is the second coldest capital city in the world after Ulaanbaatar, Mongolia [3] For this study we use the UHI investigation technology, described in [2]. According to this paper, we selected three stations: one located into city in high and midrise buildings area (including extensive lowrise and high-energy industrial - LCZ classification) and two others located in rural site (sparsely built or open-set and lightweight lowrise according LCZ classification). Also these stations must be close by distance (less than 100 km) and altitude. Therefore, first for Astana city were obtained numerical evaluations for UHI climate dynamics, UHI dependence of synoptic situations and total UHI climatology on monthly and daily averages. References: 1.Howard, L. (1833) The Climate of London, Deduced from Meteorological Observations. Volume 2, London. 2.Kukanova E.A., Konstantinov P.I. An urban heat islands climatology in Russia and linkages to the climate change In Geophysical Research Abstracts, volume 16 of EGU General Assembly, pages EGU2014-10833-1, Germany, 2014. Germany. 3.www.pogoda.ru.net

  9. Extreme Heat and Health: Perspectives from Health Service Providers in Rural and Remote Communities in South Australia

    PubMed Central

    Williams, Susan; Bi, Peng; Newbury, Jonathan; Robinson, Guy; Pisaniello, Dino; Saniotis, Arthur; Hansen, Alana

    2013-01-01

    Among the challenges for rural communities and health services in Australia, climate change and increasing extreme heat are emerging as additional stressors. Effective public health responses to extreme heat require an understanding of the impact on health and well-being, and the risk or protective factors within communities. This study draws on lived experiences to explore these issues in eleven rural and remote communities across South Australia, framing these within a socio-ecological model. Semi-structured interviews with health service providers (n = 13), and a thematic analysis of these data, has identified particular challenges for rural communities and their health services during extreme heat. The findings draw attention to the social impacts of extreme heat in rural communities, the protective factors (independence, social support, education, community safety), and challenges for adaptation (vulnerabilities, infrastructure, community demographics, housing and local industries). With temperatures increasing across South Australia, there is a need for local planning and low-cost strategies to address heat-exacerbating factors in rural communities, to minimise the impact of extreme heat in the future. PMID:24173140

  10. Extreme heat and health: perspectives from health service providers in rural and remote communities in South Australia.

    PubMed

    Williams, Susan; Bi, Peng; Newbury, Jonathan; Robinson, Guy; Pisaniello, Dino; Saniotis, Arthur; Hansen, Alana

    2013-11-01

    Among the challenges for rural communities and health services in Australia, climate change and increasing extreme heat are emerging as additional stressors. Effective public health responses to extreme heat require an understanding of the impact on health and well-being, and the risk or protective factors within communities. This study draws on lived experiences to explore these issues in eleven rural and remote communities across South Australia, framing these within a socio-ecological model. Semi-structured interviews with health service providers (n = 13), and a thematic analysis of these data, has identified particular challenges for rural communities and their health services during extreme heat. The findings draw attention to the social impacts of extreme heat in rural communities, the protective factors (independence, social support, education, community safety), and challenges for adaptation (vulnerabilities, infrastructure, community demographics, housing and local industries). With temperatures increasing across South Australia, there is a need for local planning and low-cost strategies to address heat-exacerbating factors in rural communities, to minimise the impact of extreme heat in the future. PMID:24173140

  11. Future frequencies of extreme weather events in the National Wildlife Refuges of the conterminous U.S.

    USGS Publications Warehouse

    Martinuzzi, Sebastian; Allstadt, Andrew J.; Bateman, Brooke L.; Heglund, Patricia J.; Pidgeon, Anna M.; Thogmartin, Wayne E.; Vavrus, Stephen J.; Radeloff, Volker C.

    2016-01-01

    Climate change is a major challenge for managers of protected areas world-wide, and managers need information about future climate conditions within protected areas. Prior studies of climate change effects in protected areas have largely focused on average climatic conditions. However, extreme weather may have stronger effects on wildlife populations and habitats than changes in averages. Our goal was to quantify future changes in the frequency of extreme heat, drought, and false springs, during the avian breeding season, in 415 National Wildlife Refuges in the conterminous United States. We analyzed spatially detailed data on extreme weather frequencies during the historical period (1950–2005) and under different scenarios of future climate change by mid- and late-21st century. We found that all wildlife refuges will likely experience substantial changes in the frequencies of extreme weather, but the types of projected changes differed among refuges. Extreme heat is projected to increase dramatically in all wildlife refuges, whereas changes in droughts and false springs are projected to increase or decrease on a regional basis. Half of all wildlife refuges are projected to see increases in frequency (> 20% higher than the current rate) in at least two types of weather extremes by mid-century. Wildlife refuges in the Southwest and Pacific Southwest are projected to exhibit the fastest rates of change, and may deserve extra attention. Climate change adaptation strategies in protected areas, such as the U.S. wildlife refuges, may need to seriously consider future changes in extreme weather, including the considerable spatial variation of these changes.

  12. It's the Heat AND the Humidity -- Assessment of Extreme Heat Scenarios to Enable the Assessment of Climate Impacts on Public Health

    NASA Technical Reports Server (NTRS)

    Crosson, William L; Al-Hamdan, Mohammad Z.; Economou, Sigrid, A.; Estes, Maurice G.; Estes, Sue M.; Puckett, Mark; Quattrochi, Dale A

    2013-01-01

    In the United States, extreme heat is the most deadly weather-related hazard. In the face of a warming climate and urbanization, which contributes to local-scale urban heat islands, it is very likely that extreme heat events (EHEs) will become more common and more severe in the U.S. In a NASA-funded project supporting the National Climate Assessment, we are providing historical and future measures of extreme heat to enable assessments of the impacts of heat on public health over the coterminous U.S. We use atmospheric temperature and humidity information from meteorological reanalysis and from Global Climate Models (GCMs) to provide data on past and future heat events. The project s emphasis is on providing assessments of the magnitude, frequency and geographic distribution of extreme heat in the U.S. to facilitate public health studies. In our approach, long-term climate change is captured with GCM output, and the temporal and spatial characteristics of short-term extremes are represented by the reanalysis data. Two future time horizons, 2040 and 2090, are the focus of future assessments; these are compared to the recent past period of 1981-2000. We are characterizing regional-scale temperature and humidity conditions using GCM output for two climate change scenarios (A2 and A1B) defined in the Special Report on Emissions Scenarios (SRES). For each future period, 20 years of multi-model GCM output have been analyzed to develop a heat stress climatology based on statistics of extreme heat indicators. Differences between the two future and past periods have been used to define temperature and humidity changes on a monthly time scale and regional spatial scale. These changes, combined with hourly historical meteorological data at a spatial scale (12 km) much finer than that of GCMs, enable us to create future climate realizations, from which we compute the daily heat stress measures and related spatially-specific climatological fields. These include the mean annual

  13. Extreme heat reduces and shifts United States premium wine production in the 21st century.

    PubMed

    White, M A; Diffenbaugh, N S; Jones, G V; Pal, J S; Giorgi, F

    2006-07-25

    Premium wine production is limited to regions climatically conducive to growing grapes with balanced composition and varietal typicity. Three central climatic conditions are required: (i) adequate heat accumulation; (ii) low risk of severe frost damage; and (iii) the absence of extreme heat. Although wine production is possible in an extensive climatic range, the highest-quality wines require a delicate balance among these three conditions. Although historical and projected average temperature changes are known to influence global wine quality, the potential future response of wine-producing regions to spatially heterogeneous changes in extreme events is largely unknown. Here, by using a high-resolution regional climate model forced by the Intergovernmental Panel on Climate Change Special Report on Emission Scenarios A2 greenhouse gas emission scenario, we estimate that potential premium winegrape production area in the conterminous United States could decline by up to 81% by the late 21st century. While increases in heat accumulation will shift wine production to warmer climate varieties and/or lower-quality wines, and frost constraints will be reduced, increases in the frequency of extreme hot days (>35 degrees C) in the growing season are projected to eliminate winegrape production in many areas of the United States. Furthermore, grape and wine production will likely be restricted to a narrow West Coast region and the Northwest and Northeast, areas currently facing challenges related to excess moisture. Our results not only imply large changes for the premium wine industry, but also highlight the importance of incorporating fine-scale processes and extreme events in climate-change impact studies. PMID:16840557

  14. Future extreme sea level seesaws in the tropical Pacific.

    PubMed

    Widlansky, Matthew J; Timmermann, Axel; Cai, Wenju

    2015-09-01

    Global mean sea levels are projected to gradually rise in response to greenhouse warming. However, on shorter time scales, modes of natural climate variability in the Pacific, such as the El Niño-Southern Oscillation (ENSO), can affect regional sea level variability and extremes, with considerable impacts on coastal ecosystems and island nations. How these shorter-term sea level fluctuations will change in association with a projected increase in extreme El Niño and its atmospheric variability remains unknown. Using present-generation coupled climate models forced with increasing greenhouse gas concentrations and subtracting the effect of global mean sea level rise, we find that climate change will enhance El Niño-related sea level extremes, especially in the tropical southwestern Pacific, where very low sea level events, locally known as Taimasa, are projected to double in occurrence. Additionally, and throughout the tropical Pacific, prolonged interannual sea level inundations are also found to become more likely with greenhouse warming and increased frequency of extreme La Niña events, thus exacerbating the coastal impacts of the projected global mean sea level rise. PMID:26601272

  15. Future extreme sea level seesaws in the tropical Pacific

    PubMed Central

    Widlansky, Matthew J.; Timmermann, Axel; Cai, Wenju

    2015-01-01

    Global mean sea levels are projected to gradually rise in response to greenhouse warming. However, on shorter time scales, modes of natural climate variability in the Pacific, such as the El Niño–Southern Oscillation (ENSO), can affect regional sea level variability and extremes, with considerable impacts on coastal ecosystems and island nations. How these shorter-term sea level fluctuations will change in association with a projected increase in extreme El Niño and its atmospheric variability remains unknown. Using present-generation coupled climate models forced with increasing greenhouse gas concentrations and subtracting the effect of global mean sea level rise, we find that climate change will enhance El Niño–related sea level extremes, especially in the tropical southwestern Pacific, where very low sea level events, locally known as Taimasa, are projected to double in occurrence. Additionally, and throughout the tropical Pacific, prolonged interannual sea level inundations are also found to become more likely with greenhouse warming and increased frequency of extreme La Niña events, thus exacerbating the coastal impacts of the projected global mean sea level rise. PMID:26601272

  16. Excess Mortality Attributable to Extreme Heat in New York City, 1997-2013.

    PubMed

    Matte, Thomas D; Lane, Kathryn; Ito, Kazuhiko

    2016-01-01

    Extreme heat event excess mortality has been estimated statistically to assess impacts, evaluate heat emergency response, and project climate change risks. We estimated annual excess non-external-cause deaths associated with extreme heat events in New York City (NYC). Extreme heat events were defined as days meeting current National Weather Service forecast criteria for issuing heat advisories in NYC based on observed maximum daily heat index values from LaGuardia Airport. Outcomes were daily non-external-cause death counts for NYC residents from May through September from 1997 to 2013 (n = 337,162). The cumulative relative risk (CRR) of death associated with extreme heat events was estimated in a Poisson time-series model for each year using an unconstrained distributed lag for days 0-3 accommodating over dispersion, and adjusting for within-season trends and day of week. Attributable death counts were computed by year based on individual year CRRs. The pooled CRR per extreme heat event day was 1.11 (95%CI 1.08-1.14). The estimated annual excess non-external-cause deaths attributable to heat waves ranged from -14 to 358, with a median of 121. Point estimates of heat wave-attributable deaths were greater than 0 in all years but one and were correlated with the number of heat wave days (r = 0.81). Average excess non-external-cause deaths associated with extreme heat events were nearly 11-fold greater than hyperthermia deaths. Estimated extreme heat event-associated excess deaths may be a useful indicator of the impact of extreme heat events, but single-year estimates are currently too imprecise to identify short-term changes in risk. PMID:27081885

  17. The assessment of future extremes of air temperature to design EPR type power plants

    NASA Astrophysics Data System (ADS)

    Parey, S.; Hoang, T. T. H.; Dacunha-Castelle, D.

    2010-09-01

    EDF projects the construction of new EPR type nuclear power plants in Europe. These installations are likely to run until the second half of the century, and thus, it is necessary to think their dimensioning in taking current knowledge of climate change impact into account. This paper will present the study dedicated to the estimation of future extremes of air temperature by using the statistical extreme value theory. The adopted methodology consists firstly in comparing current climate temperature extremes between local observations and models at the nearest grid point. Then, if the extremes of both series are comparable, future extremes are derived from the modelled series for a future period. In parallel, the link between the evolution of the mean, variance and extremes is studied in the observation series. If a strong link is identified, future extremes are derived from the stationary extremes of the centred and normalised series and the changes in mean and variance given by climate models for the desired future period. The approach will be illustrated with an example of such an evaluation for an EPR project in the United Kingdom.

  18. Woven Thermal Protection System Based Heat-shield for Extreme Entry Environments Technology (HEEET)

    NASA Technical Reports Server (NTRS)

    Ellerby, Donald; Venkatapathy, Ethiraj; Stackpoole, Margaret; Chinnapongse, Ronald; Munk, Michelle; Dillman, Robert; Feldman, Jay; Prabhu, Dinesh; Beerman, Adam

    2013-01-01

    NASA's future robotic missions utilizing an entry system into Venus and the outer planets, namely, Saturn, Uranus, Neptune, result in extremely high entry conditions that exceed the capabilities of state of the art low to mid density ablators such as PICA or Avcoat. Therefore mission planners typically assume the use of a fully dense carbon phenolic heat shield similar to what was flown on Pioneer Venus and Galileo. Carbon phenolic is a robust TPS material however its high density and relatively high thermal conductivity constrain mission planners to steep entries, with high heat fluxes and pressures and short entry durations, in order for CP to be feasible from a mass perspective. The high entry conditions pose challenges for certification in existing ground based test facilities and the longer-term sustainability of CP will continue to pose challenges. In 2012 the Game Changing Development Program (GCDP) in NASA's Space Technology Mission Directorate funded NASA ARC to investigate the feasibility of a Woven Thermal Protection System (WTPS) to meet the needs of NASA's most challenging entry missions. This project was highly successful demonstrating that a Woven TPS solution compares favorably to CP in performance in simulated reentry environments and provides the opportunity to manufacture graded materials that should result in overall reduced mass solutions and enable a much broader set of missions than does CP. Building off the success of the WTPS project GCDP has funded a follow on project to further mature and scale up the WTPS concept for insertion into future NASA robotic missions. The matured WTPS will address the CP concerns associated with ground based test limitations and sustainability. This presentation will briefly discuss results from the WTPS Project and the plans for WTPS maturation into a heat-shield for extreme entry environment.

  19. Woven Thermal Protection System Based Heat-shield for Extreme Entry Environments Technology (HEEET)

    NASA Technical Reports Server (NTRS)

    Chinnapongse, Ronald; Ellerbe, Donald; Stackpoole, Maragaret; Venkatapathy, Ethiraj; Beerman, Adam; Feldman, Jay; Peterson Keith; Prabhu, Dinesh; Dillman, Robert; Munk, Michelle

    2013-01-01

    NASA's future robotic missions utilizing an entry system into Venus and the outer planets, namely, Saturn, Uranus, Neptune, result in extremely severe entry conditions that exceed the capabilities of state of the art low to mid density ablators such as PICA or Avcoat. Therefore mission planners typically assume the use of a fully dense carbon phenolic heat shield similar to what was flown on Pioneer Venus and Galileo. Carbon phenolic (CP) is a robust TPS material however its high density and relatively high thermal conductivity constrain mission planners to steep entries, with high heat fluxes and pressures and short entry durations, in order for CP to be feasible from a mass perspective. The high entry conditions pose challenges for certification in existing ground based test facilities and the longer-­-term sustainability of CP will continue to pose challenges. In 2012 the Game Changing Development Program (GCDP) in NASA's Space Technology Mission Directorate funded NASA ARC to investigate the feasibility of a Woven Thermal Protection System (WTPS) to meet the needs of NASA's most challenging entry missions. This project was highly successful demonstrating that a Woven TPS solution compares favorably to CP in performance in simulated reentry environments and provides the opportunity to manufacture graded materials that should result in overall reduced mass solutions and enable a much broader set of missions than does CP. Building off the success of the WTPS project GCDP has funded a follow on project to further mature and scale up the WTPS concept for insertion into future NASA robotic missions. The matured WTPS will address the CP concerns associated with ground based test limitations and sustainability. This presentation will briefly discuss results from the WTPS Project and the plans for WTPS maturation into a heat-­-shield for extreme entry environment.

  20. Extreme Adaptive Optics Testbed: Results and Future Work

    SciTech Connect

    Evans, J W; Sommargren, G; Poyneer, L; Macintosh, B; Severson, S; Dillon, D; Sheinis, A; Palmer, D; Kasdin, J; Olivier, S

    2004-07-15

    'Extreme' adaptive optics systems are optimized for ultra-high-contrast applications, such as ground-based extrasolar planet detection. The Extreme Adaptive Optics Testbed at UC Santa Cruz is being used to investigate and develop technologies for high-contrast imaging, especially wavefront control. A simple optical design allows us to minimize wavefront error and maximize the experimentally achievable contrast before progressing to a more complex set-up. A phase shifting diffraction interferometer is used to measure wavefront errors with sub-nm precision and accuracy. We have demonstrated RMS wavefront errors of <1.3 nm and a contrast of >10{sup -7} over a substantial region using a shaped pupil. Current work includes the installation and characterization of a 1024-actuator Micro-Electro-Mechanical- Systems (MEMS) deformable mirror, manufactured by Boston Micro-Machines, which will be used for wavefront control. In our initial experiments we can flatten the deformable mirror to 1.8-nm RMS wavefront error within a control radius of 5-13 cycles per aperture. Ultimately this testbed will be used to test all aspects of the system architecture for an extrasolar planet-finding AO system.

  1. Heat-related deaths after an extreme heat event--four states, 2012, and United States, 1999-2009.

    PubMed

    2013-06-01

    On June 29, 2012, a rapidly moving line of intense thunderstorms with high winds swept across the midwestern and eastern United States, causing widespread damage and power outages. Afterward, the area experienced extreme heat, with maximum temperatures exceeding 100°F (37.8°C). This report describes 32 heat-related deaths in Maryland, Ohio, Virginia, and West Virginia that occurred during the 2 weeks following the storms and power outages. Median age of the decedents was 65 years, and most of the excessive heat exposures occurred within homes. During 1999-2009, an annual average of 658 heat-related deaths occurred in the United States. Heat-related deaths are preventable, and heat response plans should be in place before an extreme heat event (EHE). Interventions should focus on identifying and limiting heat exposure among vulnerable populations. PMID:23739336

  2. A non-equilibrium model for soil heating and moisture transport during extreme surface heating

    NASA Astrophysics Data System (ADS)

    Massman, William

    2016-04-01

    The increasing use of prescribed fire by land managers and increasing likelihood of wildfires due to climate change requires an improved modeling capability of extreme heating of soils during fires. This study describes a new model of soil evaporation and transport of heat, soil moisture, and water vapor, for use during fires. The model is based on conservation equations of energy and mass and its performance is evaluated against dynamic soil temperature and moisture observations obtained during laboratory experiments on soil samples exposed to surface heat fluxes ranging between 10,000 and 50,000 Wm2. In general, the model simulates the observed temperature dynamics quite well, but is less precise (but still good) at capturing the moisture dynamics. The model emulates the observed increase in soil moisture ahead of the drying front and the hiatus in the soil temperature rise during the strongly evaporative stage of drying. It also captures the observed rapid evaporation of soil moisture that occurs at relatively low temperatures (50-90 C), and can provide quite accurate predictions of the total amount of soil moisture evaporated during the laboratory experiments. Overall, this new model provides a much more physically realistic simulation over all previous models developed for the same purpose.

  3. High resolution climate projections to assess the future vulnerability of European urban areas to climatological extreme events

    NASA Astrophysics Data System (ADS)

    Fallmann, Joachim; Wagner, Sven; Emeis, Stefan

    2015-10-01

    Results from high resolution 7-km WRF regional climate model (RCM) simulations are used to analyse changes in the occurrence frequencies of heat waves, of precipitation extremes and of the duration of the winter time freezing period for highly populated urban areas in Central Europe. The projected climate change impact is assessed for 11 urban areas based on climate indices for a future period (2021-2050) compared to a reference period (1971-2000) using the IPCC AR4 A1B Scenario as boundary conditions. These climate indices are calculated from daily maximum, minimum and mean temperatures as well as precipitation amounts. By this, the vulnerability of these areas to future climate conditions is to be investigated. The number of heat waves, as well as the number of single hot days, tropical nights and heavy precipitation events is projected to increase in the near future. In addition, the number of frost days is significantly decreased. Probability density functions of monthly mean summer time temperatures show an increase of the 95th percentile of about 1-3 °C for the future compared with the reference period. The projected increase of cooling and decrease of heating degree days indicate the possible impact on urban energy consumption under future climate conditions.

  4. Analysis of meteorological parameters of different extreme heat waves

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heat waves have caused severe losses in beef cattle feedlots and dairies in different areas of the cattle producing areas of the world. A comparison of climatic conditions that have resulted in cattle deaths has been completed. Analyses of lethal heat waves in northeast Nebraska in 1999 and north ...

  5. Attributing Human Mortality During Extreme Heat Waves to Anthropogenic Climate Change

    NASA Astrophysics Data System (ADS)

    Mitchell, D.; Heaviside, C.; Vardoulakis, S.; Huntingford, C.; Masato, G.; Guillod, B. P.; Frumhoff, P. C.; Bowery, A.; Allen, M. R.

    2015-12-01

    Climate change is the biggest global health threat of the 21st century (Costello et al, 2009; Watts et al, 2015). Perhaps one of the clearest examples of this is the summer heat wave of 2003, which saw up to seventy thousand excess deaths across Europe (Robine et al, 2007). The extreme temperatures are now thought to be significantly enhanced due to anthropogenic climate change (Stott et al, 2004; Christidis et al, 2015). Here, we consider not only the Europe-wide temperature response of the heat wave, but the localised response using a high-resolution regional model simulating 2003 climate conditions thousands of times. For the first time, by employing end-to-end attribution, we attribute changes in mortality to the increased radiative forcing from climate change, with a specific focus on London and Paris. We show that in both cities, a sizable proportion of the excess mortality can be attributed to human emissions. With European heat waves projected to increase into the future, these results provide a worrying reality for what may lie ahead. Christidis, Nikolaos, Gareth S. Jones, and Peter A. Stott. "Dramatically increasing chance of extremely hot summers since the 2003 European heatwave." Nature Climate Change (2014). Costello, Anthony, et al. "Managing the health effects of climate change: lancet and University College London Institute for Global Health Commission." The Lancet 373.9676 (2009): 1693-1733. Stott, Peter A., Dáithí A. Stone, and Myles R. Allen. "Human contribution to the European heatwave of 2003." Nature 432.7017 (2004): 610-614 Watts, N., et al. "Health and climate change: policy responses to protect public health." Lancet. 2015.

  6. Warm-season diurnal circulations and heat extremes over the northwest U.S

    NASA Astrophysics Data System (ADS)

    Brewer, Matthew C.

    Summer synoptic circulations over the northwest U.S., and their interactions with regional terrain, land/water contrasts, and surface heating, give rise to a variety of fascinating meteorological phenomena, many of which have yet to be explored. Furthermore, it is largely unknown how projected future warming associated with increased greenhouse gases will modify these important features. The work herein seeks to ameliorate this with a comprehensive examination of two important aspects of northwest U.S. summer weather and climate: diurnal circulations and changes to the conditions associated with extreme temperatures under anthropogenic global warming. To simulate regional diurnal circulations, GFS model output was obtained for July and August 2009-2011. These data were categorized into hour of the day, composited, and the resulting files were used to initialize and provide boundary conditions to a WRF (version 3.5) model run. It was shown that, when compared to observations, this WRF run sufficiently simulates average diurnal variability. Using this simulation, the diurnal circulations of the region were described, including several important wind features within the Strait of Juan de Fuca, the Snoqualmie Pass, and the Columbia River Gorge. Also, regional nocturnal low-level wind maxima are described, including one over the northern Willamette valley and another over the high plateau of eastern Oregon. Recent work by the authors has elucidated the physical mechanisms that drive heat extremes over the northwest U.S., including the necessity of a ridge aloft, with associated subsidence and advection warming. Also, easterly flow is crucial for keeping the marine air at bay, and producing downslope flow and adiabatic warming on the western slopes of regional north-south terrain barriers. Given the rising temperatures projected under anthropogenic global warming, how are these conditions, and associated low-level temperature distributions, projected to change? As a

  7. A non-equilibrium model for soil heating and moisture transport during extreme surface heating

    NASA Astrophysics Data System (ADS)

    Massman, W. J.

    2015-03-01

    With increasing use of prescribed fire by land managers and increasing likelihood of wildfires due to climate change comes the need to improve modeling capability of extreme heating of soils during fires. This issue is addressed here by developing a one-dimensional non-equilibrium model of soil evaporation and transport of heat, soil moisture, and water vapor, for use with surface forcing ranging from daily solar cycles to extreme conditions encountered during fires. The model employs a linearized Crank-Nicolson scheme for the conservation equations of energy and mass and its performance is evaluated against dynamic soil temperature and moisture observations obtained during laboratory experiments on soil samples exposed to surface heat fluxes ranging between 10 000 and 50 000 W m-2. The Hertz-Knudsen equation is the basis for constructing the model's non-equilibrium evaporative source term. The model includes a dynamic residual soil moisture as a function of temperature and soil water potential, which allows the model to capture some of the dynamic aspects of the strongly bound soil moisture that seems to require temperatures well beyond 150 °C to fully evaporate. Furthermore, the model emulates the observed increase in soil moisture ahead of the drying front and the hiatus in the soil temperature rise during the strongly evaporative stage of drying. It also captures the observed rapid evaporation of soil moisture that occurs at relatively low temperatures (50-90 °C). Sensitivity analyses indicate that the model's success results primarily from the use of a temperature and moisture potential dependent condensation coefficient in the evaporative source term. The model's solution for water vapor density (and vapor pressure), which can exceed one standard atmosphere, cannot be experimentally verified, but they are supported by results from (earlier and very different) models developed for somewhat different purposes and for different porous media. Overall, this non

  8. Intra-seasonal drivers of extreme heat over Australia in observations and POAMA-2

    NASA Astrophysics Data System (ADS)

    Marshall, A. G.; Hudson, D.; Wheeler, M. C.; Alves, O.; Hendon, H. H.; Pook, M. J.; Risbey, J. S.

    2014-10-01

    We assess the occurrence and probability of extreme heat over Australia in association with the Southern Annular Mode (SAM), persistent anticyclones over the Tasman Sea, and the Madden-Julian Oscillation (MJO), which have previously been shown to be key drivers of intra-seasonal variations of Australian climate. In this study, extreme heat events are defined as occurring when weekly-mean maximum temperature anomalies exceed the 90th percentile. The observed probability of exceedance is reduced during the positive phase of the SAM and enhanced during the negative phase of the SAM over most of Australia. Persistent anticyclones over the Tasman Sea are described in terms of (1) split-flow blocking at 160°E and (2) high pressure systems located in the vicinity of the subtropical ridge (STRHs), about 10° north of the split-flow blocking region, for which we devise a simple index. Split-flow blocks and STRHs have contrasting impacts on the occurrence of extreme heat over Australia, with STRHs showing enhanced probability of upper decile heat events over southern Australia in all seasons. The observed probability of an upper decile heat event varies according to MJO phase and time of year, with the greatest impact of the MJO on extreme heat occurring over southern Australia (including the Mallee agricultural region) in spring during phases 2-3. We show that this modulation of the probability of extreme heat by the SAM, persistent anticyclones over the Tasman Sea, and the MJO is well simulated in the Bureau of Meteorology dynamical intra-seasonal/seasonal forecast model POAMA-2 at lead times of 2-3 weeks. We further show that predictability of heat extremes increases in association with the negative SAM phase, STRH and MJO, thus providing a basis for skilful intra-seasonal prediction of heat extremes.

  9. Formation of extreme surface turbulent heat fluxes from the ocean to the atmosphere in the North Atlantic

    NASA Astrophysics Data System (ADS)

    Tilinina, N. D.; Gulev, S. K.; Gavrikov, A. V.

    2016-01-01

    The role of extreme surface turbulent fluxes in total oceanic heat loss in the North Atlantic is studied. The atmospheric circulation patterns enhancing ocean-atmosphere heat flux in regions with significant contributions of the extreme heat fluxes (up to 60% of the net heat loss) are analyzed. It is shown that extreme heat fluxes in the Gulf Stream and the Greenland and Labrador Seas occur in zones with maximal air pressure gradients, i.e., in cyclone-anticyclone interaction zones.

  10. Emergence of heat extremes attributable to anthropogenic influences

    NASA Astrophysics Data System (ADS)

    King, Andrew D.; Black, Mitchell T.; Min, Seung-Ki; Fischer, Erich M.; Mitchell, Daniel M.; Harrington, Luke J.; Perkins-Kirkpatrick, Sarah E.

    2016-04-01

    Climate scientists have demonstrated that a substantial fraction of the probability of numerous recent extreme events may be attributed to human-induced climate change. However, it is likely that for temperature extremes occurring over previous decades a fraction of their probability was attributable to anthropogenic influences. We identify the first record-breaking warm summers and years for which a discernible contribution can be attributed to human influence. We find a significant human contribution to the probability of record-breaking global temperature events as early as the 1930s. Since then, all the last 16 record-breaking hot years globally had an anthropogenic contribution to their probability of occurrence. Aerosol-induced cooling delays the timing of a significant human contribution to record-breaking events in some regions. Without human-induced climate change recent hot summers and years would be very unlikely to have occurred.

  11. A Review of Recent Advances in Research on Extreme Heat Events

    NASA Technical Reports Server (NTRS)

    Horton, Radley M.; Mankin, Justin S.; Lesk, Corey; Coffel, Ethan; Raymond, Colin

    2016-01-01

    Reviewing recent literature, we report that changes in extreme heat event characteristics such as magnitude, frequency, and duration are highly sensitive to changes in mean global-scale warming. Numerous studies have detected significant changes in the observed occurrence of extreme heat events, irrespective of how such events are defined. Further, a number of these studies have attributed present-day changes in the risk of individual heat events and the documented global-scale increase in such events to anthropogenic-driven warming. Advances in process-based studies of heat events have focused on the proximate land-atmosphere interactions through soil moisture anomalies, and changes in occurrence of the underlying atmospheric circulation associated with heat events in the mid-latitudes. While evidence for a number of hypotheses remains limited, climate change nevertheless points to tail risks of possible changes in heat extremes that could exceed estimates generated from model outputs of mean temperature. We also explore risks associated with compound extreme events and nonlinear impacts associated with extreme heat.

  12. Self-contained heat rejection module for future spacecraft

    NASA Technical Reports Server (NTRS)

    Fleming, M. L.; Williams, J. L.; Baskett, J. D.; Leach, J. W.

    1975-01-01

    This paper discusses development of a Self-Contained Heat Rejection Module (SHRM) which can be used on a wide variety of future spacecraft launched by the space shuttle orbiter. The SHRM contains radiators which are deployed by a scissor-mechanism and the flow equipment including pumps, accumulator, by-pass valves, and controllers necessary to reject heat from those radiators. Heat transfer between SHRM and the parent vehicle is effected by a contact heat exchanger. This device provides heat transfer between two separate flow loops through a mechanical connection. This approach reduces the time required to attach the SHRM to the payload, and increases the reliability of the SHRM flow loop since breaking into the fluid system in the field is not required. The SHRM concept also includes a refrigeration system to increase heat rejection capacity in adverse environments, or to provide for a lower return temperature, down to -23 C.

  13. Futures markets and petroleum supply. A study of heating oil futures

    SciTech Connect

    Farmer, R.D.

    1986-04-02

    The study evaluates the month-to-month performance of the wholesale heating oil market in the East Coast region over the past three winters as influenced by the price of heating oil futures traded on the New York Mercantile Exchange (NYMEX) for New York Harbor delivery. The economic basis for the analysis is derived from a conceptual model of petroleum refiner and marketer behavior. In this model, futures trading and cash market plans are described as being jointly formulated to maximize profits and minimize risk. A comparison of price and inventory levels indicated by the model for a ''no futures'' and a ''futures'' case provides an indication of how the introduction of futures trading may have influenced petroleum markets. The study demonstrates that the ''no futures'' model provides a better explanation of actual cash market prices than does the ''futures'' model, but that the ''futures'' model provides a better explanation of inventory levels. Estimates of inventory change support a finding that petroleum suppliers are using futures to manage risk in a manner consistent with the ''futures'' model described in this paper. The fact that the ''no futures'' model provides a marginally better explanation of cash prices, however, suggests that risk attitudes still influence the petroleum supply and demand decisions of many market participants. The ''no futures'' model always performs best when the futures price is used to represent price expectations, underscoring the importance of the futures market as an information source, even to those businesses that do not trade in futures. At the same time, the magnitudes of the differences between the ''futures'' and the ''no futures'' estimates of cash prices and primary inventory change are very small, suggesting the overall influence of futures trading on petroleum supply has not been great. This conclusion is consistent with industry reports that refiners are only peripherally in the refined product futures markets.

  14. Recent Advances in Regional Climate System Modeling and ClimateChange Analyses of Extreme Heat

    SciTech Connect

    Miller, Norman L.

    2004-09-24

    During the period May 2003 to May 2004, there were two CEC/PIER funded primary research activities by the Atmosphere and Ocean Sciences Group/Earth Science Division at LBNL. These activities are the implementation and testing of the National Center for Atmospheric Research Community Land Model (CLM) into MM5, and the analysis of extreme heat days under a new set of climate simulations. The new version of MM5,MM5-CLM, has been tested for a 90 day snowmelt period in the northwestern U.S. Results show that this new code upgrade, as compared to the MM5-NOAH, has improved snowmelt, temperature, and precipitation when compared to observations. These are due in part to a subgrid scheme,advanced snow processes, and advanced vegetation. The climate change analysis is the upper and lower IPCC Special Report on Emission Scenarios, representing fossil fuel intensive and energy conserving future emission scenarios, and medium and low sensitivity Global Climate Models. Results indicate that California cities will see increases in the number of heat wave and temperature threshold days from two to six times.These results may be viewed as potential outcomes based on today's decisions on emissions.

  15. Assessing the impacts of changing precipitation and temperature extremes on the current and future ecohydrology of grassland ecosystems

    NASA Astrophysics Data System (ADS)

    Brunsell, N. A.; Nippert, J. B.; Ocheltree, T.

    2012-12-01

    Extreme weather events have profound impacts on water and carbon cycling. However, events of similar magnitude may have very different impacts depending upon the timing of the event in the phenological cycle. We assess these impacts of extreme daily weather events including precipitation, maximum and minimum temperature using data collected from the Konza Prairie Long Term Ecological Research site in the central U.S. We utilize the long term weather and biomass collection data at the LTER site to examine the historical variability of extreme events and the impacts on annual carbon dynamics. Timescales of interactions between daily weather and fluxes are quantified through a multiscale information theoretic approach. In addition, we quantify the impacts of the timing and magnitude of extreme events through a Critical Climate Period (CCP) analysis. Results indicate a strong sensitivity to spring precipitation and summer temperature. Using six years of eddy covariance data, we can isolate more of the biophysical mechanisms governing the responses to extreme weather events. Of particular interest is the heat wave of July, 2011, where daily maximum temperatures were over 38 C for 24 consecutive days and resulted in drastically reduced above ground carbon allocation than in previous years. In addition, we employ the Agro-BGC model to assess the biophysical processes responsible for determining the response of water and carbon dynamics to extreme weather events. This is done by employing a stochastic weather generator with prescribed changes in annual precipitation and temperature conistent with GCM projections. Developing a more thorough understanding of extreme events and the differential responses due to the timing and magnitude of the events will potentially assist in the mitigation of future climate change.

  16. Urban effects on extreme heat in a mid-sized North American city

    NASA Astrophysics Data System (ADS)

    Schatz, J.; Kucharik, C. J.

    2013-12-01

    As climate change drives global temperatures higher, heat waves are projected to increase in frequency, intensity, and duration, particularly in cities where the urban heat island effect can further raise local temperatures. Cities contain 50% of the global population and 80% of the North American population, and these percentages are projected to reach 70% globally and 87% in North America by 2030. This creates a need to understand the nature of heat events not just globally but also within cities where local climate variation can be substantial. That local variation could prove highly consequential for heat adaptation in cities, making it important to understand the dynamics of extreme heat within urban landscapes. Our study addresses this need by characterizing 400m-resolution variation in air temperature and heat index during a historically hot year in Madison, Wisconsin. Madison is a mid-sized temperate city with a metropolitan area population of 568,593. It is surrounded by several large lakes and a complex rural landscape of agriculture, forests, wetlands, and grasslands. In 2012, Madison experienced its hottest year and third hottest summer on record, with the Madison airport reporting 39 days exceeding 90°F compared to an average of 9 days. In March 2012, we installed 135 Onset HOBO ProV2 T/RH sensors across the Madison area to record air temperature and relative humidity at 15 minute intervals. The data from this network provides a unique opportunity to study small-scale spatial variation in the magnitude and duration of hot conditions that are projected to become more common in the future. Our sensors recorded substantial variation in the magnitude and duration of high temperatures and heat indices during the summer of 2012. For temperature, the densest parts of the city experienced >200 hours ≥90°F compared to <100 hours in many rural areas. Temperatures ≥100°F occurred up to 22 hours in some parts of the city versus 0 hours in much of the rural

  17. Heat-related mortality in Cyprus for current and future climate scenarios.

    PubMed

    Heaviside, Clare; Tsangari, Haritini; Paschalidou, Anastasia; Vardoulakis, Sotiris; Kassomenos, Pavlos; Georgiou, Kyriakos E; Yamasaki, Edna N

    2016-11-01

    Extreme temperatures have long been associated with adverse health impacts, ranging from minor illness, to increased hospitalizations and mortality. Heat-related mortality during summer months is likely to become an increasing public health problem in future due to the effects of climate change. We performed a health impact assessment for heat-related mortality for the warm months of April-September for the years 2004 to 2009 inclusive, for the city of Nicosia and for Cyprus as a whole, based on separately derived exposure-response functions. We further estimated the potential future heat-related mortality by including climate projections for southern Europe, which suggest changes in temperature of between 1°C and 5°C over the next century. There were 32 heat-related deaths per year in Cyprus over the study period. When adding the projected increase in temperature due to climate change, there was a substantial increase in mortality: for a 1°C increase in temperature, heat related mortality in Cyprus was estimated to double to 64 per year, and for a 5°C increase, heat-related mortality was expected to be 8 times the baseline rate for the warm season (281 compared with 32). This analysis highlights the importance of preparing for potential health impacts due to heat in Cyprus, particularly under a changing climate. PMID:27376918

  18. Actual and future trends of extreme values of temperature for the NW Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Taboada, J.; Brands, S.; Lorenzo, N.

    2009-09-01

    It is now very well established that yearly averaged temperatures are increasing due to anthropogenic climate change. In the area of Galicia (NW Spain) this trend has also been determined. The main objective of this work is to assess actual and future trends of different extreme indices of temperature, which are of curcial importance for many impact studies. Station data for the study was provided by the CLIMA database of the regional government of Galicia (NW Spain). As direct GCM-output significantly underestimates the variance of daily surface temperature variables in NW Spain, these variables are obtained by applying a statistical downscaling technique (analog method), using 850hPa temperature and mean sea level pressure as combined predictors. The predictor fields have been extracted from three GCMs participating in the IPCC AR4 under A1, A1B and A2 scenarios. The definitions of the extreme indices have been taken from the joint CCl/CLIVAR/JCOMM Expert Team (ET) on Climate Change Detection and Indices (ETCCDI) This group has defined a set of standard extreme values to simplify intercomparisons of data from different regions of the world. For the temperatures in the period 1960-2006, results show a significant increase of the number of days with maximum temperatures above the 90th percentile. Furthermore, a significant decrease of the days with maximum temperatures below the 10th percentile has been found. The tendencies of minimum temperatures are reverse: less nights with minimum temperatures below 10th percentile, and more with minimum temperatures above 90th percentile. Those tendencies can be observed all over the year, but are more pronounced in summer. We have also calculated the relationship between the above mentioned extreme values and different teleconnection patterns appearing in the North Atlantic area. Results show that local tendencies are associated with trends of EA (Eastern Atlantic) and SCA (Scandinavian) patterns. NAO (North Atlantic

  19. Climate Model Simulation of Present and Future Extreme Events in Latin America and the Caribbean: What Spatial Resolution is Required?

    NASA Astrophysics Data System (ADS)

    Rowe, C. M.; Oglesby, R. J.; Mawalagedara, R.; Mohammad Abadi Kamarei, A.

    2015-12-01

    Latin America and the Caribbean are at risk of extreme climate events, including flooding rains, damaging winds, drought, heat waves, and in high elevation mountainous regions, excessive snowfalls. The causes of these events are numerous - flooding rains and damaging winds are often associated with tropical cyclones, but also can occur, either separately or in tandem, due to smaller, more localized storms. Similarly, heat waves and droughts can be large scale or localized, and frequently occur together (as excessive drying can lead to enhanced heating, while enhanced heating in turn promotes additional drying). Even in the tropics, extreme snow and ice events can have severe consequences due to avalanches, and also impact water resources. Understanding and modeling the climate controls behind these extreme events requires consideration of a range of time and space scales. A common strategy is to use a global climate model (GCM) to simulate the large-scale (~100km) daily atmospheric controls on extreme events. A limited area, high resolution regional climate model (RCM) is then employed to dynamically downscale the results, so as to better incorporate the influence of topography and, secondarily, the nature of the land cover. But what resolution is required to provide the necessary results, i.e., minimize biases due to improper resolution? In conjunction with our partners from participating Latin American and Caribbean nations, we have made an extensive series of simulations, both region-wide and for individual countries, using the WRF regional climate model to downscale output from a variety of GCMs, as well as Reanalyses (as a proxy for observations). The simulations driven by the Reanalyses are used for robust model verification against actual weather station observations. The simulations driven by GCMs are designed to provide projections of future climate, including importantly how the nature and number of extreme events may change through coming decades. Our

  20. Climate projections of future extreme events accounting for modelling uncertainties and historical simulation biases

    NASA Astrophysics Data System (ADS)

    Brown, Simon J.; Murphy, James M.; Sexton, David M. H.; Harris, Glen R.

    2014-11-01

    A methodology is presented for providing projections of absolute future values of extreme weather events that takes into account key uncertainties in predicting future climate. This is achieved by characterising both observed and modelled extremes with a single form of non-stationary extreme value (EV) distribution that depends on global mean temperature and which includes terms that account for model bias. Such a distribution allows the prediction of future "observed" extremes for any period in the twenty-first century. Uncertainty in modelling future climate, arising from a wide range of atmospheric, oceanic, sulphur cycle and carbon cycle processes, is accounted for by using probabilistic distributions of future global temperature and EV parameters. These distributions are generated by Bayesian sampling of emulators with samples weighted by their likelihood with respect to a set of observational constraints. The emulators are trained on a large perturbed parameter ensemble of global simulations of the recent past, and the equilibrium response to doubled CO2. Emulated global EV parameters are converted to the relevant regional scale through downscaling relationships derived from a smaller perturbed parameter regional climate model ensemble. The simultaneous fitting of the EV model to regional model data and observations allows the characterisation of how observed extremes may change in the future irrespective of biases that may be present in the regional models simulation of the recent past climate. The clearest impact of a parameter perturbation in this ensemble was found to be the depth to which plants can access water. Members with shallow soils tend to be biased hot and dry in summer for the observational period. These biases also appear to have an impact on the potential future response for summer temperatures with some members with shallow soils having increases for extremes that reduce with extreme severity. We apply this methodology for London, using the

  1. Impact of Extreme Heat Events on Emergency Department Visits in North Carolina (2007-2011).

    PubMed

    Fuhrmann, Christopher M; Sugg, Margaret M; Konrad, Charles E; Waller, Anna

    2016-02-01

    Extreme heat is the leading cause of weather-related mortality in the U.S. Extreme heat also affects human health through heat stress and can exacerbate underlying medical conditions that lead to increased morbidity and mortality. In this study, data on emergency department (ED) visits for heat-related illness (HRI) and other selected diseases were analyzed during three heat events across North Carolina from 2007 to 2011. These heat events were identified based on the issuance and verification of heat products from local National Weather Service forecast offices (i.e. Heat Advisory, Heat Watch, and Excessive Heat Warning). The observed number of ED visits during these events were compared to the expected number of ED visits during several control periods to determine excess morbidity resulting from extreme heat. All recorded diagnoses were analyzed for each ED visit, thereby providing insight into the specific pathophysiological mechanisms and underlying health conditions associated with exposure to extreme heat. The most common form of HRI was heat exhaustion, while the percentage of visits with heat stroke was relatively low (<10%). The elderly (>65 years of age) were at greatest risk for HRI during the early summer heat event (8.9 visits per 100,000), while young and middle age adults (18-44 years of age) were at greatest risk during the mid-summer event (6.3 visits per 100,000). Many of these visits were likely due to work-related exposure. The most vulnerable demographic during the late summer heat event was adolescents (15-17 years of age), which may relate to the timing of organized sports. This demographic also exhibited the highest visit rate for HRI among all three heat events (10.5 visits per 100,000). Significant increases (p < 0.05) in visits with cardiovascular and cerebrovascular diseases were noted during the three heat events (3-8%). The greatest increases were found in visits with hypotension during the late summer event (23%) and sequelae during

  2. Simulations of Future Heat stress in the Northeast in a Convection Resolving Model

    NASA Astrophysics Data System (ADS)

    Huber, M.; Buzan, J. R.; Komurcu, M.; Krishnan, S.; McCabe, E.

    2015-12-01

    Heat stress is a chiefly a byproduct of temperature and humidity extremes and can be phrased in terms of wetbulb or dewpoint temperature. Consequently, it is a buoyancy related atmospheric variable which could alternatively be expressed as something like subcloud layer entropy or convective available potential energy (CAPE). Expressed in this latter way, predicting heat stress extreme events is equivalent to understanding the distribution of events in which convection is inhibited. Our goal in this study is to use a convection resolving model (the Weather Research and Forecasting Model at 3km grid spacing) to predict heat stress in future climate scenarios. The primary benefit relative to simply using a global climate model output is the removal of the ad hoc treatment of convective inhibition imposed by parameterization of convection in course resolution simulations. We focus on heat stress metrics relevant for humans and livestock within the Northeast of the U.S. and demonstrate the difference in projected heat stress engendered by explicitly resolving convection.

  3. Extremely heat tolerant photosymbiosis in a shallow marine benthic foraminifera

    NASA Astrophysics Data System (ADS)

    Schmidt, Christiane; Danna, Titelboim; Janett, Brandt; Raphael, Morard; Barak, Herut; Sigal, Abramovich; Ahuva, Almogi-Labin; Michal, Kucera

    2016-04-01

    Thermal stress leads to the loss of algal symbionts (bleaching) in many shallow marine calcifiers including foraminifera. The bleaching threshold often occurs at water temperatures, which are likely to be exceeded in the near future due to global warming. Preadaptation represents one mechanism allowing photosymbiotic organisms to persist under warmer conditions, providing the tolerance can be carried to new habitats. Here we provide evidence for the existence of such adaptation in the benthic foraminifera Pararotalia calcariformata recently discovered in the eastern Mediterranean. We identify its symbionts as a consortium of diatom species dominated by Minutocellus polymorphus. We show that in the field, the foraminifera retains its pigments at a thermally polluted site, where peak water temperatures reach 36°C. To test whether this tolerance represents a widespread adaptation, we conducted manipulative experiments exposing populations from an unpolluted site to elevated temperatures for up to three weeks. The populations were kept in co-culture with the more thermally sensitive diatom-bearing foraminifera Amphistegina lobifera. Reduced photosynthetic activity in A. lobifera occurred at 32°C whereas photochemical stress in P. calcariformata was first observed during exposure to 36°C and chronic photoinhibition (but not mortality) first occurred at 42°C. Survivorship was high in all treatments, and growth was observed under thermal conditions similar to summer maxima at the thermally polluted site (35-36°C). The photosymbiosis in P. calcariformata is unusually thermally tolerant for a photosymbiont-bearing eukaryote. The thermal tolerance of this photosymbiosis is present in a natural environment where its thermal threshold is never realized. These observations imply that photosymbiosis in marine protists can respond to elevated temperatures by drawing on a pool of naturally occurring pre-adaptations. It also provides a perspective on the massive occurrence of

  4. Future changes in atmospheric circulation types and related precipitation extremes in Central Europe

    NASA Astrophysics Data System (ADS)

    Homann, Markus; Jacobeit, Jucundus; Beck, Christoph; Philipp, Andreas

    2016-04-01

    The statistical evaluation of the relationships between atmospheric circulation types and areal precipitation events took place in the context of an international project called WETRAX (Weather patterns, storm tracks and related precipitation extremes). The aim of the project was to estimate the regional flooding potential in Central Europe under enhanced climate change conditions. For parts of southern Central Europe, a gridded daily precipitation set with 6km horizontal resolution has been generated for the period 1951-2006 by the Austrian Zentralanstalt für Meteorologie und Geodynamik (ZAMG). To determine regions with similar precipitation variability, a S-mode principal component analysis has been applied. Extreme precipitation events are defined by the 95% percentile, based on regional arithmetic means of daily precipitation. Large-scale atmospheric circulation types have been derived by different statistical methods and variables using the COST733 classification software and gridded daily NCEP1 reanalysis data. To evaluate the performance of a particular circulation type classification with respect to regional precipitation extremes, multiple regression models have been derived between the circulation type frequencies as predictor variables and monthly frequencies of extreme precipitation as well as monthly rainfall amounts from these events. To estimate the regional flooding potential in Central Europe under enhanced climate change conditions, multiple regression models are applied to different projected GCM predictor data. Thus, future changes in circulation type occurrence frequencies are transferred into assessments of future changes in precipitation extremes on a regional scale.

  5. Atmospheric Rivers in the CESM: Validation, Connections to Extreme Precipitation, and Projections for the Future

    NASA Astrophysics Data System (ADS)

    Shields, C. A.; Kiehl, J. T.

    2014-12-01

    Atmospheric Rivers (ARs) are long, narrow, intense, and evolving filamentary structures responsible for transporting significant amounts of moisture from the tropics to mid-latitudes and are often associated with extreme winter-time precipitation for regions such as the West Coast of the United States. The Community Earth System Model (CESM) captures these synoptic scale structures as well as their extreme precipitation. The CESM version employed utilizes high resolution atmosphere/land components (0.5o) coupled to the standard (1o) ocean/ice components. The high resolution atmosphere is able to more accurately represent extreme, regional precipitation. Cataloguing AR events in long-term climate simulations where centuries of data are produced requires an automated AR-identification algorithm that captures the spatial and temporal structures of these events. These algorithms may vary in complexity but all necessitate the inclusion of water vapor content thresholds. The adoption of observationally based empirical threshold values may not translate well to future climate projections as increased temperatures change the background water vapor content (Clausius-Clapeyron relationship). Here, we evaluate spatial and temporal characteristics of Western U.S. ARs in CESM and compare them to observations. A variety of threshold definitions will be discussed which span observationally based values of water vapor content to values relative to the background state (more appropriate for future climate). Model simulated extreme precipitation related to AR's and results from the RCP8.5 future climate scenario will be shown.

  6. Vibroacoustic Analysis of Large Heat Rejection Radiators for Future Spacecraft

    NASA Technical Reports Server (NTRS)

    Larko, Jeffrey M.; McNelis, Mark E.; Hughes, William O.

    2006-01-01

    Spacecraft structures such as antennas, solar arrays and radiator panels significantly respond to high acoustic levels seen at lift-off. Some future spacecraft may utilize nuclear electric propulsion that require large radiator panels to reject waste heat. A vibroacoustic assessment was performed for two different radiator panel designs. Results from the analysis of the two designs using different analytical approaches are presented and discussed.

  7. The Spanish tourist sector facing extreme climate events: a case study of domestic tourism in the heat wave of 2003

    NASA Astrophysics Data System (ADS)

    Gómez-Martín, M. Belén; Armesto-López, Xosé A.; Martínez-Ibarra, Emilio

    2013-04-01

    This research explores, by means of a questionnaire-based survey, public knowledge and perception as well as the behaviour of young Spanish tourists before, during and after the summer holiday period affected by an episode of extreme heat in 2003. The survey was administered between November and December 2004. The extraordinary heat wave of the summer of 2003 can be seen as an example of a normal episode in terms of the predicted intensity and duration of European summers towards the end of the twenty-first century. It can therefore be used as the laboratory setting for this study. In this context, the use of the climate analogue approach allows us to obtain novel perspectives regarding the future impact that this type of event could have on tourist demand, based on a real experience. Likewise, such an approach allows the strategies of adaptation implemented by the different elements in the tourist system in order to cope with the atmospheric episode to be evaluated. Such strategies could prove useful in reducing vulnerability when faced with similar episodes in the future. The main results indicate that Spanish tourists (young segment market) are flexible in adapting to episodes of extremely high temperatures. Their personal perception of the phenomenon, their behaviour and the adaptation measures implemented to a greater or lesser extent before that time, reduce the vulnerability of the sector when faced with this type of event, at least from the point of view of this young segment of the internal national market. In Spain, the episode of extreme heat of 2003 has led to the implementation or improvement of some adaptive measures after the event, especially in the fields of management, policy and education.

  8. The Spanish tourist sector facing extreme climate events: a case study of domestic tourism in the heat wave of 2003.

    PubMed

    Gómez-Martín, M Belén; Armesto-López, Xosé A; Martínez-Ibarra, Emilio

    2014-07-01

    This research explores, by means of a questionnaire-based survey, public knowledge and perception as well as the behaviour of young Spanish tourists before, during and after the summer holiday period affected by an episode of extreme heat in 2003. The survey was administered between November and December 2004. The extraordinary heat wave of the summer of 2003 can be seen as an example of a normal episode in terms of the predicted intensity and duration of European summers towards the end of the twenty-first century. It can therefore be used as the laboratory setting for this study. In this context, the use of the climate analogue approach allows us to obtain novel perspectives regarding the future impact that this type of event could have on tourist demand, based on a real experience. Likewise, such an approach allows the strategies of adaptation implemented by the different elements in the tourist system in order to cope with the atmospheric episode to be evaluated. Such strategies could prove useful in reducing vulnerability when faced with similar episodes in the future. The main results indicate that Spanish tourists (young segment market) are flexible in adapting to episodes of extremely high temperatures. Their personal perception of the phenomenon, their behaviour and the adaptation measures implemented to a greater or lesser extent before that time, reduce the vulnerability of the sector when faced with this type of event, at least from the point of view of this young segment of the internal national market. In Spain, the episode of extreme heat of 2003 has led to the implementation or improvement of some adaptive measures after the event, especially in the fields of management, policy and education. PMID:23619577

  9. The Spanish tourist sector facing extreme climate events: a case study of domestic tourism in the heat wave of 2003

    NASA Astrophysics Data System (ADS)

    Gómez-Martín, M. Belén; Armesto-López, Xosé A.; Martínez-Ibarra, Emilio

    2014-07-01

    This research explores, by means of a questionnaire-based survey, public knowledge and perception as well as the behaviour of young Spanish tourists before, during and after the summer holiday period affected by an episode of extreme heat in 2003. The survey was administered between November and December 2004. The extraordinary heat wave of the summer of 2003 can be seen as an example of a normal episode in terms of the predicted intensity and duration of European summers towards the end of the twenty-first century. It can therefore be used as the laboratory setting for this study. In this context, the use of the climate analogue approach allows us to obtain novel perspectives regarding the future impact that this type of event could have on tourist demand, based on a real experience. Likewise, such an approach allows the strategies of adaptation implemented by the different elements in the tourist system in order to cope with the atmospheric episode to be evaluated. Such strategies could prove useful in reducing vulnerability when faced with similar episodes in the future. The main results indicate that Spanish tourists (young segment market) are flexible in adapting to episodes of extremely high temperatures. Their personal perception of the phenomenon, their behaviour and the adaptation measures implemented to a greater or lesser extent before that time, reduce the vulnerability of the sector when faced with this type of event, at least from the point of view of this young segment of the internal national market. In Spain, the episode of extreme heat of 2003 has led to the implementation or improvement of some adaptive measures after the event, especially in the fields of management, policy and education.

  10. Observed changes in seasonal heat waves and warm temperature extremes in the Romanian Carpathians

    NASA Astrophysics Data System (ADS)

    Micu, Dana; Birsan, Marius-Victor; Dumitrescu, Alexandru; Cheval, Sorin

    2015-04-01

    Extreme high temperature have a large impact on environment and human activities, especially in high elevation areas particularly sensitive to the recent climate warming. The climate of the Romanian Carpathians became warmer particularly in winter, spring and summer, exibiting a significant increasing frequency of warm extremes. The paper investigates the seasonal changes in the frequency, duration and intensity of heat waves in relation to the shifts in the daily distribution of maximum temperatures over a 50-year period of meteorological observations (1961-2010). The paper uses the heat wave definition recommended by the Expert Team on Climate Change Detection and Indices (ETCCDI) and exploits the gridded daily dataset of maximum temperature at 0.1° resolution (~10 km) developed in the framework of the CarpatClim project (www.carpatclim.eu). The seasonal changes in heat waves behavior were identified using the Mann-Kendall non-parametric trend test. The results suggest an increase in heat wave frequency and a lengthening of intervals affected by warm temperature extremes all over the study region, which are explained by the shifts in the upper (extreme) tail of the daily maximum temperature distribution in most seasons. The trends are consistent across the region and are well correlated to the positive phases of the East Atlantic Oscillation. Our results are in good agreement with the previous temperature-related studies concerning the Carpathian region. This study was realized within the framework of the project GENCLIM, financed by UEFISCDI, code PN-II 151/2014.

  11. Whole-body heating decreases skin vascular response to low orthostatic stress in the lower extremities.

    PubMed

    Yamazaki, Fumio; Nakayama, Yoshiro; Sone, Ryoko

    2006-04-01

    To elucidate the influence of heat stress on cutaneous vascular response in the lower extremities during orthostatic stress, a head-up tilt (HUT) test at angles of 15 degrees, 30 degrees, 45 degrees, and 60 degrees for 4 min each was conducted under normothermic control conditions followed by whole-body heat stress produced by a hot water-perfused suit in healthy volunteers. Skin blood flows (SkBF) in the forearm, thigh, and calf were monitored using laser-Doppler flowmetry throughout the experiment. Furthermore, to elucidate the effects of increased core and local skin temperatures on the local vascular response in calf skin under increasing orthostatic stress, the thigh was occluded at 20, 30, 50, 70, and 80 mmHg with a cuff in both the normothermic condition and the whole-body or local heating condition. Significant decreases in forearm SkBF during HUT were observed at an angle of 60 degrees during normothermia and at 30 degrees or more during heating. SkBF in the thigh and calf was decreased significantly by HUT at 15 degrees and above during normothermia, and there was no significant reduction of SkBF in these sites during HUT at the lower angles (15 degrees -45 degrees ) during whole-body heating. Significant decreases of calf SkBF were observed at cuff pressures of 20 mmHg and above during normothermia and of 30 mmHg and above during whole-body and local heating, respectively. These results suggest that SkBF in the lower extremities shows a marked reduction compared with the upper extremities during low orthostatic stress in normothermia, and the enhanced skin vasoconstrictor response in the lower extremities is diminished by both whole-body and local heat stress. PMID:16839449

  12. Assessment of future variability in extreme precipitation and the potential effects on the wadi flow regime.

    PubMed

    Gunawardhana, Luminda Niroshana; Al-Rawas, Ghazi A; Kazama, So; Al-Najar, Khalid A

    2015-10-01

    The objective of this study is to investigate how the magnitude and occurrence of extreme precipitation events are affected by climate change and to predict the subsequent impacts on the wadi flow regime in the Al-Khod catchment area, Muscat, Oman. The tank model, a lumped-parameter rainfall-runoff model, was used to simulate the wadi flow. Precipitation extremes and their potential future changes were predicted using six-member ensembles of general circulation models (GCMs) from the Coupled Model Intercomparison Project Phase 5 (CMIP5). Yearly maxima of the daily precipitation and wadi flow for varying return periods were compared for observed and projected data by fitting the generalized extreme value (GEV) distribution function. Flow duration curves (FDC) were developed and compared for the observed and projected wadi flows. The results indicate that extreme precipitation events consistently increase by the middle of the twenty-first century for all return periods (49-52%), but changes may become more profound by the end of the twenty-first century (81-101%). Consequently, the relative change in extreme wadi flow is greater than twofolds for all of the return periods in the late twenty-first century compared to the relative changes that occur in the mid-century period. Precipitation analysis further suggests that greater than 50% of the precipitation may be associated with extreme events in the future. The FDC analysis reveals that changes in low-to-moderate flows (Q60-Q90) may not be statistically significant, whereas increases in high flows (Q5) are statistically robust (20 and 25% for the mid- and late-century periods, respectively). PMID:26370197

  13. The Challenges of Producing Societally-useful Projections of Future Changes in Extreme Precipitation Events

    NASA Astrophysics Data System (ADS)

    Kunkel, K.; Redmond, K. T.; Karl, T. R.; Easterling, D. R.; Liang, X.

    2010-12-01

    The design of dams, roads, storm sewers, housing developments, and other types of infrastructure must consider the climatology of extreme precipitation. Probable maximum precipitation (PMP) estimates are needed for reservoir and spillway design where under-design would be catastrophic. Intensity-duration-frequency (IDF) values are used in design situations where there is tradeoff between the losses arising from occasional exceedances of those values and the costs of building in additional resilience. An underlying consideration is that many such structures are build to last for many decades. Any structures built today are expected to last through a period of time when anthropogenically-forced changes in climate may be quite large. However, the uncertainties surrounding possible future changes in extreme precipitation climatology are also very large and reduction of those uncertainties is a major challenge. Possible avenues toward more reliable estimates of future changes in extreme precipitation climatology include the following: 1. Weather models, theoretical and expert analysis: : As an example, PMP estimates are derived in part from inclusion and maximization of all the major factors that influence precipitation rates and duration in well-tested empirical precipitation algorithms.. Future changes in some of these factors are likely to be amenable to theoretical consideration, such as water vapor availability. This factor is largely driven by temperature, both of the atmosphere and the ocean surface, and is much better defined in future climate models compared to mean precipitation. For these reasons, uncertainties about future changes in mean precipitation do not necessarily translate to uncertainties about extreme precipitation rates. 2. Climate model improvements: Accurate precipitation simulation poses a particular challenge for models, as relevant processes occur over a wide spectrum of spatial and temporal scales, including important processes at sub

  14. Using dry and wet year hydroclimatic extremes to guide future hydrologic projections

    NASA Astrophysics Data System (ADS)

    Oni, Stephen; Futter, Martyn; Ledesma, Jose; Teutschbein, Claudia; Buttle, Jim; Laudon, Hjalmar

    2016-07-01

    There are growing numbers of studies on climate change impacts on forest hydrology, but limited attempts have been made to use current hydroclimatic variabilities to constrain projections of future climatic conditions. Here we used historical wet and dry years as a proxy for expected future extreme conditions in a boreal catchment. We showed that runoff could be underestimated by at least 35 % when dry year parameterizations were used for wet year conditions. Uncertainty analysis showed that behavioural parameter sets from wet and dry years separated mainly on precipitation-related parameters and to a lesser extent on parameters related to landscape processes, while uncertainties inherent in climate models (as opposed to differences in calibration or performance metrics) appeared to drive the overall uncertainty in runoff projections under dry and wet hydroclimatic conditions. Hydrologic model calibration for climate impact studies could be based on years that closely approximate anticipated conditions to better constrain uncertainty in projecting extreme conditions in boreal and temperate regions.

  15. Increased hospital admissions associated with extreme-heat exposure in King County, Washington, 1990-2010

    PubMed Central

    Isaksen, Tania Busch; Yost, Michael G.; Hom, Elizabeth K.; Ren, You; Lyons, Hilary; Fenske, Richard A.

    2016-01-01

    Increased morbidity and mortality have been associated with extreme heat events, particularly in temperate climates. Few epidemiologic studies have considered the impact of extreme heat events on hospitalization rates in the Pacific Northwest region. This study quantifies the historical (May to September 1990-2010) heat-morbidity relationship in the most populous Pacific Northwest County -King County, Washington. A relative risk (RR) analysis was used to explore the association between heat and all non-traumatic hospitalizations on 99th percentile heat days, while a time series analysis using a piece-wise linear model approximation was used to estimate the effect that heat’s intensity has on hospitalizations, adjusted for temporal trends and day of the week. A non-statistically significant 2% [95% CI: 1.02 (0.98, 1.05)] increase in hospitalization risk, on a heat day versus a non-heat day, was noted for all-ages, all non-traumatic causes. When considering the effect heat intensity has on admissions, we found a statistically significant 1.59% (95% CI: 0.9%, 2.29%) increase in admissions per degree increase in humidex above 37.4 °C. Admissions stratified by cause and age produced statistically significant results with both relative risk and time series analyses for nephritis and nephrotic syndromes, acute renal failure and natural heat exposure hospitalizations. This study demonstrates that heat, expressed as humidex, is associated with increased hospital admissions. When stratified by age and cause of admission, the non-elderly (less than 85) age groups experience significant risk for: nephritis and nephrotic syndromes, acute renal failure, natural heat exposure, COPD and asthma hospitalizations. PMID:25719287

  16. Vulnerability to extreme heat and climate change: is ethnicity a factor?

    PubMed Central

    Hansen, Alana; Bi, Linda; Saniotis, Arthur; Nitschke, Monika

    2013-01-01

    Background With a warming climate, it is important to identify sub-populations at risk of harm during extreme heat. Several international studies have reported that individuals from ethnic minorities are at increased risk of heat-related illness, for reasons that are not often discussed. Objective The aim of this article is to investigate the underpinning reasons as to why ethnicity may be associated with susceptibility to extreme heat, and how this may be relevant to Australia’s population. Design Drawing upon literary sources, the authors provide commentary on this important, yet poorly understood area of heat research. Results Social and economic disparities, living conditions, language barriers, and occupational exposure are among the many factors contributing to heat-susceptibility among minority ethnic groups in the United States. However, there is a knowledge gap about socio-cultural influences on vulnerability in other countries. Conclusion More research needs to be undertaken to determine the effects of heat on tourists, migrants, and refugees who are confronted with a different climatic environment. Thorough epidemiological investigations of the association between ethnicity and heat-related health outcomes are required, and this could be assisted with better reporting of nationality data in health statistics. Climate change adaptation strategies in Australia and elsewhere need to be ethnically inclusive and cognisant of an upward trend in the proportion of the population who are migrants and refugees. PMID:23899408

  17. Uncertainty analysis in future extreme flow projections in Jinhua River Basin, East China

    NASA Astrophysics Data System (ADS)

    Xu, Y.; Tian, Y.; Booij, M.

    2013-12-01

    Uncertainties in extreme high flows originating from greenhouse gas emission scenarios, hydrological model structures and their parameters for the Jinhua River basin, East China are assessed. The baseline (1961-1990) and future (2011-2040) climates for A1B, A2 and B2 scenarios are downscaled from the General Circulation Model (GCM) using the PRECIS Regional Climate Model with a spatial resolution of 50km×50km. A distribution-based bias correction method is applied to bias correct the PRECIS -derived temperature and precipitation. The bias corrected precipitation and temperature are then used as inputs for three hydrological models (GR4J, HBV and Xinanjiang) to simulate extreme high flows in the study area. The parameter uncertainty is quantified by means of the Generalized Likelihood Uncertainty Estimation (GLUE) method for each hydrological model for three emission scenarios. It is found that compared with the baseline period, the extreme high flows tend to decrease under scenario A1B, A2 and B2. The largest uncertainty is observed in the HBV model and the GR4J model has the smallest uncertainty. It is found that the major source of uncertainty in this study is from parameters, followed by the uncertainties from the hydrological model structure and the emission scenarios have the smallest uncertainty contribution to extreme high flows in this study. 90% confidence intervals of 50-year extreme hight flows under scenarios A1B, A2 and B2

  18. Extreme Heat

    MedlinePlus

    ... Hazardous Materials Incidents Home Fires Household Chemical Emergencies Hurricanes Landslides & Debris Flow Nuclear Blast Nuclear Power Plants ... Hazardous Materials Incidents Home Fires Household Chemical Emergencies Hurricanes Landslides & Debris Flow Nuclear Blast Nuclear Power Plants ...

  19. Future of landfalling atmospheric rivers with extreme precipitation in British Columbia

    NASA Astrophysics Data System (ADS)

    Radic, V.; Menounos, B.; Cannon, A. J.; Gi, C.

    2014-12-01

    Synoptic weather patterns that enhance water vapour transport over North Pacific Ocean are common triggers for autumn flooding events in coastal British Columbia (BC). The bulk of this water vapor transport takes place through narrow corridors known as atmospheric rivers (ARs) that occur within the warm conveyor belt of extratropical cyclones. Global climate models (GCMs) simulate ARs to varying degrees, however, all GCMs can simulate the synoptic patterns that favor ARs development. Thus by looking into the synoptic patterns in GCMs one can indirectly investigate future changes in frequency and intensity of AR events, a goal that we have set for this study. First we evaluate the performance of five GCMs in simulating the synoptic patterns responsible for AR-extreme events (landfalling ARs in BC with extreme precipitation over the province). As reference data we used four reanalysis data-sets for the period 1979-2010. With the use of a clustering algorithm we identified characteristic daily patterns of integrated vapour transport (IVT) over the North Pacific Ocean, and further identified the IVT patterns linked to AR-extreme events. We find that for the period 1974-2005 all five GCMs are relatively unsuccessful in simulating the frequencies of these patterns, as well as total precipitation during the AR-extreme events. Despite the large range of projections and uncertainties, better performing GCMs agree in their projections for the end of the 21st century, simulating more frequent AR-extreme events, as well higher precipitation totals during these events. In the best performing model ensemble of three GCMs, the projections according to RCP4.5 emission scenario reveal an increase of AR-extreme events from 18% per extended fall season (Sep-Dec) in 1974-2005 to 22% in 2070-2100, while the seasonal (Sep-Dec) AR-extreme total precipitation averaged over BC increases by 44% between the two periods.

  20. Quantifying Future Changes in Extreme Precipitation Events Based on Resolved Synoptic Atmospheric Patterns

    NASA Astrophysics Data System (ADS)

    Gao, X.; Schlosser, C. A.; Monier, E.; Entekhabi, D.

    2012-12-01

    An important question for climate change science is possible shifts in the extremes of regional water cycle, especially changes in patterns, intensity and/or frequency of extreme precipitation events. In this study, an analogue method is developed to help detect extreme precipitation events and their potential changes under future climate regimes without relying on the highly uncertain modeled precipitation. Our approach is based on the use of composite maps to identify the distinct synoptic and large-scale atmospheric conditions that lead to extreme precipitation events at local scales. The analysis of extreme daily precipitation events, exemplified in the south-central United States, is carried out using 62-yr (1948-2010) CPC gridded station data and NASA's Modern Era Retrospective-analysis for Research and Applications (MERRA). Various aspects of the daily extremes are examined, including their historical ranking, associated common circulation features at upper and lower levels of the atmosphere, and moisture plumes. The scheme is first evaluated for the multiple climate model simulations of the 20th century from Coupled Model Intercomparison Project Phase 5 (CMIP5) archive to determine whether the statistical nature of modeled precipitation events (i.e. the numbers of occurrences over each season) could well correspond to that of the observed. Further, the approach will be applied to the CMIP5 multi-model projections of various climate change scenarios (i.e. Representative Concentration Pathways (RCP) scenarios) in the next century to assess the potential changes in the probability of extreme precipitation events. The research results from this study should be of particular significance to help society develop adaptive strategies and prevent catastrophic losses.

  1. Extreme heat and cultural and linguistic minorities in Australia: perceptions of stakeholders

    PubMed Central

    2014-01-01

    Background Despite acclimatisation to hot weather, many individuals in Australia are adversely affected by extreme heat each summer, placing added pressure on the health sector. In terms of public health, it is therefore important to identify vulnerable groups, particularly in the face of a warming climate. International evidence points to a disparity in heat-susceptibility in certain minority groups, although it is unknown if this occurs in Australia. With cultural diversity increasing, the aim of this study was to explore how migrants from different cultural backgrounds and climate experiences manage periods of extreme heat in Australia. Methods A qualitative study was undertaken across three Australian cities, involving interviews and focus groups with key informants including stakeholders involved in multicultural service provision and community members. Thematic analysis and a framework approach were used to analyse the data. Results Whilst migrants and refugees generally adapt well upon resettlement, there are sociocultural barriers encountered by some that hinder environmental adaptation to periods of extreme heat in Australia. These barriers include socioeconomic disadvantage and poor housing, language barriers to the access of information, isolation, health issues, cultural factors and lack of acclimatisation. Most often mentioned as being at risk were new arrivals, people in new and emerging communities, and older migrants. Conclusions With increasing diversity within populations, it is important that the health sector is aware that during periods of extreme heat there may be disparities in the adaptive capacity of minority groups, underpinned by sociocultural and language-based vulnerabilities in migrants and refugees. These factors need to be considered by policymakers when formulating and disseminating heat health strategies. PMID:24889099

  2. Future hydrological extremes: the uncertainty from multiple global climate and global hydrological models

    NASA Astrophysics Data System (ADS)

    Giuntoli, I.; Vidal, J.-P.; Prudhomme, C.; Hannah, D. M.

    2015-05-01

    Projections of changes in the hydrological cycle from global hydrological models (GHMs) driven by global climate models (GCMs) are critical for understanding future occurrence of hydrological extremes. However, uncertainties remain large and need to be better assessed. In particular, recent studies have pointed to a considerable contribution of GHMs that can equal or outweigh the contribution of GCMs to uncertainty in hydrological projections. Using six GHMs and five GCMs from the ISI-MIP multi-model ensemble, this study aims: (i) to assess future changes in the frequency of both high and low flows at the global scale using control and future (RCP8.5) simulations by the 2080s, and (ii) to quantify, for both ends of the runoff spectrum, GCMs and GHMs contributions to uncertainty using a two-way ANOVA. Increases are found in high flows for northern latitudes and in low flows for several hotspots. Globally, the largest source of uncertainty is associated with GCMs, but GHMs are the greatest source in snow-dominated regions. More specifically, results vary depending on the runoff metric, the temporal (annual and seasonal) and regional scale of analysis. For instance, uncertainty contribution from GHMs is higher for low flows than it is for high flows, partly owing to the different processes driving the onset of the two phenomena (e.g. the more direct effect of the GCMs' precipitation variability on high flows). This study provides a comprehensive synthesis of where future hydrological extremes are projected to increase and where the ensemble spread is owed to either GCMs or GHMs. Finally, our results underline the need for improvements in modelling snowmelt and runoff processes to project future hydrological extremes and the importance of using multiple GCMs and GHMs to encompass the uncertainty range provided by these two sources.

  3. WRF-Cordex simulations for Europe: mean and extreme precipitation for present and future climates

    NASA Astrophysics Data System (ADS)

    Cardoso, Rita M.; Soares, Pedro M. M.; Miranda, Pedro M. A.

    2013-04-01

    The Weather Research and Forecast (WRF-ARW) model, version 3.3.1, was used to perform the European domain Cordex simulations, at 50km resolution. A first simulation, forced by ERA-Interim (1989-2009), was carried out to evaluate the models performance to represent the mean and extreme precipitation in present European climate. This evaluation is based in the comparison of WRF results against the ECAD regular gridded dataset of daily precipitation. Results are comparable to recent studies with other models for the European region, at this resolution. For the same domain a control and a future scenario (RCP8.5) simulation was performed to assess the climate change impact on the mean and extreme precipitation. These regional simulations were forced by EC-EARTH model results, and, encompass the periods from 1960-2006 and 2006-2100, respectively.

  4. Aerosol effect on climate extremes in Europe under different future scenarios

    NASA Astrophysics Data System (ADS)

    Sillmann, J.; Pozzoli, L.; Vignati, E.; Kloster, S.; Feichter, J.

    2013-05-01

    This study investigates changes in extreme temperature and precipitation events under different future scenarios of anthropogenic aerosol emissions (i.e., SO2 and black and organic carbon) simulated with an aerosol-climate model (ECHAM5-HAM) with focus on Europe. The simulations include a maximum feasible aerosol reduction (MFR) scenario and a current legislation emission (CLEmod) scenario where Europe implements the MFR scenario, but the rest of the world follows the current legislation scenario and a greenhouse gas scenario. The strongest changes relative to the year 2000 are projected for the MFR scenario, in which the global aerosol reduction greatly enforces the general warming effect due to greenhouse gases and results in significant increases of temperature and precipitation extremes in Europe. Regional warming effects can also be identified from aerosol reductions under the CLEmodscenario. This becomes most obvious in the increase of the hottest summer daytime temperatures in Northern Europe.

  5. Heating dynamics and extreme ultraviolet radiation emission of laser-produced Sn plasmas

    SciTech Connect

    Yuspeh, S.; Sequoia, K. L.; Tao, Y.; Tillack, M. S.; Burdt, R. A.; Najmabadi, F.

    2010-06-28

    The impact of 1.064 mum laser absorption depth on the heating and in-band (2% bandwidth) 13.5 nm extreme ultraviolet emissions in Sn plasmas is investigated experimentally and numerically. In-band emission lasting longer than the laser pulse and separation between the laser absorption and in-band emission region are observed. Maximum efficiency is achieved by additional heating of the core of the plasma to allow the optimal temperature to expand to a lower and more optically thin density. This leads to higher temperature plasma that emits less in-band light as compared to CO{sub 2} produced plasma sources for the same application.

  6. Increased mortality associated with extreme-heat exposure in King County, Washington, 1980-2010.

    PubMed

    Isaksen, Tania Busch; Fenske, Richard A; Hom, Elizabeth K; Ren, You; Lyons, Hilary; Yost, Michael G

    2016-01-01

    Extreme heat has been associated with increased mortality, particularly in temperate climates. Few epidemiologic studies have considered the Pacific Northwest region in their analyses. This study quantified the historical (May to September, 1980-2010) heat-mortality relationship in the most populous Pacific Northwest County, King County, Washington. A relative risk (RR) analysis was used to explore the relationship between heat and all-cause mortality on 99th percentile heat days, while a time series analysis, using a piece-wise linear model fit, was used to estimate the effect of heat intensity on mortality, adjusted for temporal trends. For all ages, all causes, we found a 10% (1.10 (95% confidence interval (CI), 1.06, 1.14)) increase in the risk of death on a heat day versus non-heat day. When considering the intensity effect of heat on all-cause mortality, we found a 1.69% (95% CI, 0.69, 2.70) increase in the risk of death per unit of humidex above 36.0°C. Mortality stratified by cause and age produced statistically significant results using both types of analyses for: all-cause, non-traumatic, circulatory, cardiovascular, cerebrovascular, and diabetes causes of death. All-cause mortality was statistically significantly modified by the type of synoptic weather type. These results demonstrate that heat, expressed as humidex, is associated with increased mortality on heat days, and that risk increases with heat's intensity. While age was the only individual-level characteristic found to modify mortality risks, statistically significant increases in diabetes-related mortality for the 45-64 age group suggests that underlying health status may contribute to these risks. PMID:25956805

  7. Increased mortality associated with extreme-heat exposure in King County, Washington, 1980-2010

    NASA Astrophysics Data System (ADS)

    Isaksen, Tania Busch; Fenske, Richard A.; Hom, Elizabeth K.; Ren, You; Lyons, Hilary; Yost, Michael G.

    2016-01-01

    Extreme heat has been associated with increased mortality, particularly in temperate climates. Few epidemiologic studies have considered the Pacific Northwest region in their analyses. This study quantified the historical (May to September, 1980-2010) heat-mortality relationship in the most populous Pacific Northwest County, King County, Washington. A relative risk (RR) analysis was used to explore the relationship between heat and all-cause mortality on 99th percentile heat days, while a time series analysis, using a piece-wise linear model fit, was used to estimate the effect of heat intensity on mortality, adjusted for temporal trends. For all ages, all causes, we found a 10 % (1.10 (95 % confidence interval (CI), 1.06, 1.14)) increase in the risk of death on a heat day versus non-heat day. When considering the intensity effect of heat on all-cause mortality, we found a 1.69 % (95 % CI, 0.69, 2.70) increase in the risk of death per unit of humidex above 36.0 °C. Mortality stratified by cause and age produced statistically significant results using both types of analyses for: all-cause, non-traumatic, circulatory, cardiovascular, cerebrovascular, and diabetes causes of death. All-cause mortality was statistically significantly modified by the type of synoptic weather type. These results demonstrate that heat, expressed as humidex, is associated with increased mortality on heat days, and that risk increases with heat's intensity. While age was the only individual-level characteristic found to modify mortality risks, statistically significant increases in diabetes-related mortality for the 45-64 age group suggests that underlying health status may contribute to these risks.

  8. Future changes in precipitation patterns and extremes: a model-based approach

    NASA Astrophysics Data System (ADS)

    Mitsakis, Evangelos; Stamos, Iraklis; Anastassiadou, Kalliopi; Kammerer, Harald; Kaundinya, Ingo; Kohl, Bernhard; Kapsomenakis, John; Zerefos, Christos; Aifadopoulou, Georfia

    2016-04-01

    In recent decades, the Earth has experienced abrupt climate changes, including changes of mean precipitation heights as well as precipitation extremes. It is very likely that the abrupt climate changes which are result of the increase of the greenhouse gases (GHG) concentration (IPCC 2007) will continue with an accelerate magnitude in the coming decades. The modern tool used to project the future climate change is General Circulation Models (GCMs). Due to computational resources limitations, the horizontal resolution of present day GCMs is quite low, usually in the order of hundreds of kilometers. In such a crude resolution many local aspects of the climate are unable to be represented. In addition, the topographical input is equally crude, thus excluding important local features of the topographic forcing. For these reasons downscaling methods have been developed, which input the GCM results producing high resolution localized climate information. Dynamical downscaling is achieved using Regional Climate Models (RCMs) that increase the resolution of the GCMs to even less than 10 km. In that direction, future changes in the mean precipitation as well as precipitation extremes due to the anthropogenic climate change over the area of Greece are examined for various emission scenarios in the framework of this paper (e.g. RCP 8.5, SRES A1B, etc.). Regarding Greece, future changes are based on daily precipitation data from 18 Region Climate Models simulations (6 for RCP 8.5 and 12 for SRES A1B). The changes in precipitation extremes are defined by calculating the changes of nine extreme precipitation indices which are divided in three categories: percentile (R75p, R95p, R99p), absolute threshold (Rmax, R10, R20, R50, RX5day) and duration (CDD) indices, as defined by the Expert Team on Climate Change Detection and Indices (ETCCDI). Taking into account all the results that are discussed explicitly in the following sections we conclude that the mean precipitation as well as

  9. The analyses of extreme climate events over China based on CMIP5 historical and future simulations

    NASA Astrophysics Data System (ADS)

    Yang, S.; Dong, W.; Feng, J.; Chou, J.

    2013-12-01

    The extreme climate events have a serious influence on human society. Based on observations and 12 simulations from Coupled Model Intercomparison Project Phase 5 (CMIP5), Climatic extremes and their changes over china in history and future scenarios of three Representative Concentration Pathways (RCPs) are analyzed. Because of the background of global warming, in observations, the frost days (FD) and low-temperature threshold days (TN10P) have decreasing trend, and summer days (SU), high-temperature threshold days (TX90P), the heavy precipitation days (R20) and contribution of heavy precipitation days (P95T) show an increasing trend. Most coupled models can basically simulate main characteristics of most extreme indexes. The models reproduce the mean FD and TX90P value best and can give basic trends of the FD, TN10P, SU and TX90P. High correlation coefficients between simulated results and observation are found in FD, SU and P95T. For FD and SU index, most of the models have good ability to capture the spatial differences between the mean state of the 1986-2005 and 1961-1980 periods, but for other indexes, most of models' simulation ability for spatial disparity are not so satisfactory and have to be promoted. Under the high emission scenario of RCP8.5, the century-scale linear changes of Multi-Model Ensembles (MME) for FD, SU, TN10P, TX90P, R20 and P95T are -46.9, 46.0, -27.1, 175.4, 2.9 days and 9.9%, respectively. Due to the complexities of physical process parameterizations and the limitation of forcing data, a large uncertainty still exists in the simulations of climatic extremes. Fig.1 Observed and modeled multi-year average for each index (Dotted line: observation) Table1. Extreme index definition

  10. Attributing human mortality during extreme heat waves to anthropogenic climate change

    NASA Astrophysics Data System (ADS)

    Mitchell, Daniel; Heaviside, Clare; Vardoulakis, Sotiris; Huntingford, Chris; Masato, Giacomo; Guillod, Benoit P.; Frumhoff, Peter; Bowery, Andy; Wallom, David; Allen, Myles

    2016-07-01

    It has been argued that climate change is the biggest global health threat of the 21st century. The extreme high temperatures of the summer of 2003 were associated with up to seventy thousand excess deaths across Europe. Previous studies have attributed the meteorological event to the human influence on climate, or examined the role of heat waves on human health. Here, for the first time, we explicitly quantify the role of human activity on climate and heat-related mortality in an event attribution framework, analysing both the Europe-wide temperature response in 2003, and localised responses over London and Paris. Using publicly-donated computing, we perform many thousands of climate simulations of a high-resolution regional climate model. This allows generation of a comprehensive statistical description of the 2003 event and the role of human influence within it, using the results as input to a health impact assessment model of human mortality. We find large-scale dynamical modes of atmospheric variability remain largely unchanged under anthropogenic climate change, and hence the direct thermodynamical response is mainly responsible for the increased mortality. In summer 2003, anthropogenic climate change increased the risk of heat-related mortality in Central Paris by ∼70% and by ∼20% in London, which experienced lower extreme heat. Out of the estimated ∼315 and ∼735 summer deaths attributed to the heatwave event in Greater London and Central Paris, respectively, 64 (±3) deaths were attributable to anthropogenic climate change in London, and 506 (±51) in Paris. Such an ability to robustly attribute specific damages to anthropogenic drivers of increased extreme heat can inform societal responses to, and responsibilities for, climate change.

  11. Temporal Changes in Extreme High Temerature, Heat Waves in Istanbul Between 1960-2014

    NASA Astrophysics Data System (ADS)

    Yürük, C.; Ünal, Y. S.; Bilgen, S. I.; Menteş, Ş. S.; İncecik, S.

    2015-12-01

    Climate change has crucial effects on cities and especially for informal settlements, urban poor and other vulnerable groups by influencing human health, assets and livelihoods. These impacts directly result from the variations in temperature and precipitation, and emergence of heat waves, droughts, floods and fires (IPCC, 2014). Summertime episodes with extremely high air temperatures which last for several days or longer are addressed to as heat waves and affect the weather and climate in the globe. The aim of this study is to analyze the occurrence of heat waves in terms of quantity, duration and frequency and also to evaluate the accuracy of the COSMO-CLM (CCLM) model in reproducing the characteristics of heat waves in Istanbul. The summer maximum temperatures of six Turkish State Meteorological Service (TSMS) stations are selected between 1960 and 2014 to estimate the characteristics of heat waves in Istanbul. We define the heat wave if the maximum temperatures exceed a threshold value for at least three consecutive days. The threshold value is determined as 30.5 from the 90th percentile of all six station's observations. Then it is used in the detection of the hot days, heat waves and their durations. The results show that not only the number of heat waves but also duration of heat waves increase towards the end of the study period. Especially, a significant increase in heat wave events is evident after 1990s. In 2012, the number of hot days reaches the maximum value in all stations and Kartal station located southern part of city, has the highest value of 60 hot days. Furthermore, Kartal as an urban area in the Asian side of the city, exhibits highest heat wave duration with 18 consecutive days in 1998. To estimate the relationship between urban heat island intensity and the heat waves, we examined data at 43 stations collected by Disaster Coordination Center and TSMS between 2007 and 2012. Urban heat island phenomenon is found to be related to higher

  12. Variability of Winter Extreme Heat Flux Events in Kuroshio Extension and Gulf Stream Extension Regions

    NASA Astrophysics Data System (ADS)

    Ma, X.; Chang, P.; Wu, D.; Lin, X.

    2012-12-01

    We analyzed extreme surface heat flux events, defined by daily sensible (latent) heat flux greater than 80 percentile value (hereafter referred to as high-flux events) associated with boreal winter (NDJFM) cold-air outbreaks (CAOs) in the Kuroshio Extension Region (KER) of the Northwestern Pacific, using the high-resolution NCEP-CFSR (1979-2009) and NCEP-NCAR (1948-2009) reanalysis, and compared the results to those in the Gulf Stream Region (GSR) of the Northwestern Atlantic. The average accumulated number of days of the Pacific high-flux events, which typically last fewer than 3 days, is only less than 20% of the winter period but contributes significantly (>30%) to the total sensible and latent heat fluxes during the entire winter season in the KER. These high flux events are characterized by "cold storms" with a positive geopotential height anomaly (anti-cyclone) over Japan and a negative geopotential height anomaly (cyclone) further downstream, in between which there is an anomalous northerly wind that brings cold and dry air from the Eurasian continent to the KER. In contrast, non-event days are characterized by "warm storms" that have a cyclone (an anti-cyclone) to the west (east) of the KER, bringing warm and moist air from the subtropics to the KER. There are important differences between the Pacific and Atlantic CAOs. Generally, the Atlantic CAOs occur more frequently with stronger intensity and shorter duration than those in the Pacific. The "cold storms" in the KER also differ from those in the GSR in terms of their detailed structure and orientation relative to geographic location. However, in both the Pacific and Atlantic, interannual and longer term variations of sensible and latent heat flux are determined by the high flux events, suggesting that extreme winter storm events play an important role in the mid-latitude climate system. In the Pacific basin, decadal variability dominates the low-frequency variability of total and event-day sensible and

  13. Strategies to Reduce the Harmful Effects of Extreme Heat Events: A Four-City Study

    PubMed Central

    White-Newsome, Jalonne L.; McCormick, Sabrina; Sampson, Natalie; Buxton, Miatta A.; O’Neill, Marie S.; Gronlund, Carina J.; Catalano, Linda; Conlon, Kathryn C.; Parker, Edith A.

    2014-01-01

    Extreme heat events (EHEs) are becoming more intense, more frequent and longer lasting in the 21st century. These events can disproportionately impact the health of low-income, minority, and urban populations. To better understand heat-related intervention strategies used by four U.S. cities, we conducted 73 semi-structured interviews with government and non-governmental organization leaders representing public health, general social services, emergency management, meteorology, and the environmental planning sectors in Detroit, MI; New York City, NY; Philadelphia, PA and Phoenix, AZ—cities selected for their diverse demographics, climates, and climate adaptation strategies. We identified activities these leaders used to reduce the harmful effects of heat for residents in their city, as well as the obstacles they faced and the approaches they used to evaluate these efforts. Local leaders provided a description of how local context (e.g., climate, governance and city structure) impacted heat preparedness. Despite the differences among study cities, political will and resource access were critical to driving heat-health related programming. Upon completion of our interviews, we convened leaders in each city to discuss these findings and their ongoing efforts through day-long workshops. Our findings and the recommendations that emerged from these workshops could inform other local or national efforts towards preventing heat-related morbidity and mortality. PMID:24531122

  14. Avian thermoregulation in the heat: efficient evaporative cooling allows for extreme heat tolerance in four southern hemisphere columbids.

    PubMed

    McKechnie, Andrew E; Whitfield, Maxine C; Smit, Ben; Gerson, Alexander R; Smith, Eric Krabbe; Talbot, William A; McWhorter, Todd J; Wolf, Blair O

    2016-07-15

    Birds show phylogenetic variation in the relative importance of respiratory versus cutaneous evaporation, but the consequences for heat tolerance and evaporative cooling capacity remain unclear. We measured evaporative water loss (EWL), resting metabolic rate (RMR) and body temperature (Tb) in four arid-zone columbids from southern Africa [Namaqua dove (Oena capensis, ∼37 g), laughing dove (Spilopelia senegalensis, ∼89 g) and Cape turtle dove (Streptopelia capicola, ∼148 g)] and Australia [crested pigeon (Ocyphaps lophotes), ∼186 g] at air temperatures (Ta) of up to 62°C. There was no clear relationship between body mass and maximum Ta tolerated during acute heat exposure. Maximum Tb at very high Ta was 43.1±1.0, 43.7±0.8, 44.7±0.3 and 44.3±0.8°C in Namaqua doves, laughing doves, Cape turtle doves and crested pigeons, respectively. In all four species, RMR increased significantly at Ta above thermoneutrality, but the increases were relatively modest with RMR at Ta=56°C being 32, 60, 99 and 11% higher, respectively, than at Ta=35°C. At the highest Ta values reached, evaporative heat loss was equivalent to 466, 227, 230 and 275% of metabolic heat production. The maximum ratio of evaporative heat loss to metabolic production observed in Namaqua doves, 4.66, exceeds by a substantial margin previous values reported for birds. Our results support the notion that cutaneous evaporation provides a highly efficient mechanism of heat dissipation and an enhanced ability to tolerate extremely high Ta. PMID:27207640

  15. Elevated CO2 enhances leaf senescence during extreme heat and drought in a temperate forest

    SciTech Connect

    Warren, Jeffrey; Norby, Richard J; Wullschleger, Stan D

    2011-01-01

    In 2007, an extreme drought and acute heat wave damaged ecosystems across the southeastern US, including a 19-year-old Liquidambar styraciflua L. (sweetgum) tree plantation exposed to long-term elevated CO2 treatments. Stem sap velocities in trees exposed to ambient (A) or elevated (E) CO2 were analyzed to assess potential interactions between CO2 and these weather extremes. Leaf temperature (Tleaf) and net carbon uptake (GPP) were modeled based on patterns of sap velocity to estimate indirect impacts of CO2-reduced transpiration on premature leaf senescence. Elevated CO2 reduced sap flow by 28% during early summer, and by up to 45% late in the drought during record-setting high air temperatures. Canopy transpiration and conductance declined more rapidly in ECO2 plots, resulting in ECO2 Tleaf up to 45 C, which was 1-2 C greater than ACO2 Tleaf. Pre-drought GPP was ~7% greater in ECO2 plots, then declined to 30% less than ACO2 GPP as the drought progressed. Leaf abscission peaked during this period, and was 30% greater for ECO2 trees. While ECO2 can reduce leaf-level water use under droughty conditions, acute drought or heat conditions may induce excessive stomatal closure that could offset benefits of ECO2 to temperate forest species during extreme weather events.

  16. Acquired thermotolerance and heat shock in the extremely thermophilic archaebacterium Sulfolobus sp. strain B12

    SciTech Connect

    Trent, J.D.; Osipiuk, J.; Pinkau, T. )

    1990-03-01

    The extreme thermophile Sulfolobus sp. strain B12 exhibits an acquired thermotolerance response. Thus, survival of cells from a 70{degrees}C culture at the lethal temperature of 92{degrees}C was enhanced by as much as 6 orders of magnitude over a 2-h period if the culture was preheated to 88{degrees}C for 60 min or longer before being exposed to the lethal temperature. In eubacteria and eucaryotes, acquired thermotolerance correlates with the induced synthesis of a dozen or so proteins known as heat shock proteins. In this Sulfolobus species, it correlates with the preferential synthesis of primarily one major protein (55 kilodaltons) and, to a much lesser extent, two minor proteins (28 and 35 kilodaltons). Since the synthesis of all other proteins was radically reduced and these proteins were apparently not degraded or exported, their relative abundance within the cell increased during the time the cells were becoming thermotolerant. They could not yet be related to known heat shock proteins. In immunoassays, they were not cross-reactive with antibodies against heat shock proteins from Escherichia coli (DnaK and GroE), which are highly conserved between eubacteria and eucaryotes. However, it appears that if acquired thermotolerance depends on the synthesis of protective proteins, then in this extremely thermophilic archaebacterium it depends primarily on one protein.

  17. Investigation of Loop Heat Pipe Survival and Restart After Extreme Cold Environment Exposure

    NASA Technical Reports Server (NTRS)

    Golliher, Eric; Ku, Jentung; Licari, Anthony; Sanzi, James

    2010-01-01

    NASA plans human exploration near the South Pole of the Moon, and other locations where the environment is extremely cold. This paper reports on the heat transfer performance of a loop heat pipe (LHP) exposed to extreme cold under the simulated reduced gravitational environment of the Moon. A common method of spacecraft thermal control is to use a LHP with ammonia working fluid. Typically, a small amount of heat is provided either by electrical heaters or by environmental design, such that the LHP condenser temperature never drops below the freezing point of ammonia. The concern is that a liquid-filled, frozen condenser would not restart, or that a thawing condenser would damage the tubing due to the expansion of ammonia upon thawing. This paper reports the results of an experimental investigation of a novel approach to avoid these problems. The LHP compensation chamber (CC) is conditioned such that all the ammonia liquid is removed from the condenser and the LHP is nonoperating. The condenser temperature is then reduced to below that of the ammonia freezing point. The LHP is then successfully restarted.

  18. Detection of Historical and Future Precipitation Variations and Extremes Over the Continental United States

    SciTech Connect

    Anderson, Bruce T.

    2015-12-11

    through a change in the underlying climate. As such, this method is capable of detecting “hot spot” regions—as well as “flare ups” within the hot spot regions—that have experienced interannual to multi-decadal scale variations and trends in seasonal-mean precipitation and extreme events. Further by applying the same methods to numerical climate models we can discern the fidelity of the current-generation climate models in representing detectability within the observed climate system. In this way, we can objectively determine the utility of these model systems for performing detection studies of historical and future climate change.

  19. Heat Shield for Extreme Entry Environment Technology for Near-Term Robotic Science Missions and Longer Term Human Missions

    NASA Astrophysics Data System (ADS)

    Venkatapathy, E.; Ellerby, D.

    2014-06-01

    Heat shield for Extreme Entry Environment is currently funded for technology development for mission infusion into Discovery-13 and New Frontier-4 completed missions. We will describe the technology and the approach to TRL 6 to meet infusion challenges.

  20. The 2010 Pakistan Flood and the Russia Heat Wave: Teleconnection of Extremes

    NASA Technical Reports Server (NTRS)

    Lau, William K.; Kim, K. M.

    2010-01-01

    The Pakistan flood and the Russia heat wave/Vvild fires of the summer of2010 were two of the most extreme, and catastrophic events in the histories of the two countries occurring at about the same time. To a casual observer, the timing may just be a random coincidence of nature, because the two events were separated by long distances, and represented opposite forces of nature, i.e., flood vs. drought, and water vs. fire. In this paper, using NASA satellite and NOAA reanalysis data, we presented observation evidences that that the two events were indeed physically connected.

  1. Extreme Temperature and Rainfall Events, their Changes and Future Projections in India

    NASA Astrophysics Data System (ADS)

    Dash, S. K.

    2014-12-01

    India has unique geographical location and the country spreads over a large area. The southwest and northeast monsoons are the most important quasi permanent systems which dominate the weathers in this part of the world. The summer monsoon rainfall during the months June to September has a large temporal as well as spatial variability. The surface air temperature has also a large temporal and spatial variability. For suitable scientific analysis, the whole country can be divided into several homogeneous rainfall and temperature zones. Some of the extreme weather events occurring in the country include land slides, cold wave conditions, flash floods, cyclones, heat wave conditions, floods, droughts and heavy precipitation. In the context of climate change, in addition to these extreme cases, it is important to examine all the weather events above their respective threshold levels in terms of frequencies of occurrences. Results of this study show that the atmospheric surface temperature has enhanced in all the homogeneous regions of India with a maximum value of about 10C during winter and post-monsoon months. There is a significant seasonal asymmetry in the temperature rise. Also extreme temperature events of different types have enhanced over all the regions. It is found that the total precipitation during the summer monsoon months of June to September does not show any statistically significant trend. However, the numbers of short spell high intensity rain events and dry spells have increased in the last half century. Long spell rain events, on the other hand, show decreasing trend. The decrease in the number of long spell rain events associated with similar tendencies in the number of monsoon depressions, the mean monsoon wind and its shears over India suggests that the Indian summer monsoon circulation might be weakening. This talk will also attempt to describe the changes in temperature and rainfall extremes and their projections at some selected locations in

  2. Flood risk under future climate in West Africa: linking extreme value models and flood generating processes

    NASA Astrophysics Data System (ADS)

    Tramblay, Yves; Amoussou, Ernest; Dorigo, Wouter; Mahé, Gil

    2014-05-01

    For many areas in the world, there is a need for future projections of flood risk in order to improve the possible mitigation actions. However, such an exercise is often made difficult in data-sparse regions, where the limited access to hydrometric data does not allow calibrating hydrological models in a robust way under non-stationary conditions. In this study we present an approach to estimate the possible changes in flood risks, which incorporates flood generating processes into statistical models for extreme values. This approach is illustrated for a West African catchment, the Mono River (12900km²), with discharge, precipitation and temperature data are available between 1988 and 2010 in a few stations and where the dominant flood generating process is soil saturation. A soil moisture accounting model, calibrated against a merged surface soil moisture microwave satellite dataset, is used to estimate the annual maximum soil saturation level that is then related to the location parameter of a Generalized Extreme Value model of annual maximum discharge. With such a model, it is possible to estimate the changes in flood quantiles from the changes in the annual maximum soil saturation level. An ensemble of regional climate models from the ENSEMBLES-AMMA project are then considered to estimate the potential future changes in soil saturation and subsequently the changes in flood risks for the period 2028-2050. A sensitivity analysis of the non-stationary flood quantiles has shown that with the projected changes on precipitation (-2%) and temperature (+1.22°) under the scenario A1B, the projected flood quantiles would stay in the range of the observed variability during 1988-2010. The proposed approach, relying on low data requirements and few assumptions, could be useful to estimate the projected changes in flood risks for other data-sparse catchments.

  3. Recent and future warm extreme events and high-mountain slope stability.

    PubMed

    Huggel, C; Salzmann, N; Allen, S; Caplan-Auerbach, J; Fischer, L; Haeberli, W; Larsen, C; Schneider, D; Wessels, R

    2010-05-28

    The number of large slope failures in some high-mountain regions such as the European Alps has increased during the past two to three decades. There is concern that recent climate change is driving this increase in slope failures, thus possibly further exacerbating the hazard in the future. Although the effects of a gradual temperature rise on glaciers and permafrost have been extensively studied, the impacts of short-term, unusually warm temperature increases on slope stability in high mountains remain largely unexplored. We describe several large slope failures in rock and ice in recent years in Alaska, New Zealand and the European Alps, and analyse weather patterns in the days and weeks before the failures. Although we did not find one general temperature pattern, all the failures were preceded by unusually warm periods; some happened immediately after temperatures suddenly dropped to freezing. We assessed the frequency of warm extremes in the future by analysing eight regional climate models from the recently completed European Union programme ENSEMBLES for the central Swiss Alps. The models show an increase in the higher frequency of high-temperature events for the period 2001-2050 compared with a 1951-2000 reference period. Warm events lasting 5, 10 and 30 days are projected to increase by about 1.5-4 times by 2050 and in some models by up to 10 times. Warm extremes can trigger large landslides in temperature-sensitive high mountains by enhancing the production of water by melt of snow and ice, and by rapid thaw. Although these processes reduce slope strength, they must be considered within the local geological, glaciological and topographic context of a slope. PMID:20403836

  4. Survival of the fittest: overcoming oxidative stress at the extremes of Acid, heat and metal.

    PubMed

    Maezato, Yukari; Blum, Paul

    2012-01-01

    The habitat of metal respiring acidothermophilic lithoautotrophs is perhaps the most oxidizing environment yet identified. Geothermal heat, sulfuric acid and transition metals contribute both individually and synergistically under aerobic conditions to create this niche. Sulfuric acid and metals originating from sulfidic ores catalyze oxidative reactions attacking microbial cell surfaces including lipids, proteins and glycosyl groups. Sulfuric acid also promotes hydrocarbon dehydration contributing to the formation of black "burnt" carbon. Oxidative reactions leading to abstraction of electrons is further impacted by heat through an increase in the proportion of reactant molecules with sufficient energy to react. Collectively these factors and particularly those related to metals must be overcome by thermoacidophilic lithoautotrophs in order for them to survive and proliferate. The necessary mechanisms to achieve this goal are largely unknown however mechanistics insights have been gained through genomic studies. This review focuses on the specific role of metals in this extreme environment with an emphasis on resistance mechanisms in Archaea. PMID:25371104

  5. Survival of the Fittest: Overcoming Oxidative Stress at the Extremes of Acid, Heat and Metal

    PubMed Central

    Maezato, Yukari; Blum, Paul

    2012-01-01

    The habitat of metal respiring acidothermophilic lithoautotrophs is perhaps the most oxidizing environment yet identified. Geothermal heat, sulfuric acid and transition metals contribute both individually and synergistically under aerobic conditions to create this niche. Sulfuric acid and metals originating from sulfidic ores catalyze oxidative reactions attacking microbial cell surfaces including lipids, proteins and glycosyl groups. Sulfuric acid also promotes hydrocarbon dehydration contributing to the formation of black “burnt” carbon. Oxidative reactions leading to abstraction of electrons is further impacted by heat through an increase in the proportion of reactant molecules with sufficient energy to react. Collectively these factors and particularly those related to metals must be overcome by thermoacidophilic lithoautotrophs in order for them to survive and proliferate. The necessary mechanisms to achieve this goal are largely unknown however mechanistics insights have been gained through genomic studies. This review focuses on the specific role of metals in this extreme environment with an emphasis on resistance mechanisms in Archaea. PMID:25371104

  6. Climate extremes in urban area and their impact on human health: the summer heat waves

    NASA Astrophysics Data System (ADS)

    Baldi, Marina

    2014-05-01

    In the period 1951-2012 the average global land and ocean temperature has increased by approximately 0.72°C [0.49-0.89] when described by a linear trend, and is projected to rapidly increase. Each of the past three decades has been warmer than all the previous decades, with the decade of the 2000's as the warmest, and, since 1880, nine of the ten warmest years are in the 21st century, the only exception being 1998, which was warmed by the strongest El Niño event of the past century. In parallel an increase in the frequency and intensity of extremely hot days is detected with differences at different scales, which represent an health risk specially in largely populated areas as documented for several regions in the world including the Euro-Mediterranean region. If it is still under discussion if heat wave episodes are a direct result of the warming of the lower troposphere, or if, more likely, they are a regional climate event, however heat episodes have been studied in order to define their correlation with large scale atmospheric patterns and with changes in the regional circulation. Whatever the causes and the spatio-temporal extension of the episodes, epidemiological studies show that these conditions pose increasing health risks inducing heat-related diseases including hyperthermia and heat stress, cardiovascular and respiratory illnesses in susceptible individuals with a significant increase in morbidity and mortality especially in densely populated urban areas. In several Mediterranean cities peaks of mortality associated with extremely high temperature (with simultaneous high humidity levels) have been documented showing that, in some cases, a large increase in daily mortality has been reached compared to the average for the period. The number of fatalities during the summer 2003 heat wave in Europe was estimated to largely exceed the average value of some between 22000 and 50000 cases. In the same summer it was also unusually hot across much of Asia, and

  7. Energy transport in short-pulse-laser-heated targets measured using extreme ultraviolet laser backlighting.

    PubMed

    Wilson, L A; Tallents, G J; Pasley, J; Whittaker, D S; Rose, S J; Guilbaud, O; Cassou, K; Kazamias, S; Daboussi, S; Pittman, M; Delmas, O; Demailly, J; Neveu, O; Ros, D

    2012-08-01

    The accurate characterization of thermal electron transport and the determination of heating by suprathermal electrons in laser driven solid targets are both issues of great importance to the current experiments being performed at the National Ignition Facility, which aims to achieve thermonuclear fusion ignition using lasers. Ionization, induced by electronic heat conduction, can cause the opacity of a material to drop significantly once bound-free photoionization is no longer energetically possible. We show that this drop in opacity enables measurements of the transmission of extreme ultraviolet (EUV) laser pulses at 13.9 nm to act as a signature of the heating of thin (50 nm) iron layers with a 50-nm thick parylene-N (CH) overlay irradiated by 35-fs pulses at irradiance 3×10(16) Wcm(-2). Comparing EUV transmission measurements at different times after irradiation to fluid code simulations shows that the target is instantaneously heated by hot electrons (with approximately 10% of the laser energy), followed by thermal conduction with a flux limiter of ≈0.05. PMID:23005868

  8. Experimental Realization of Extreme Heat Flux Concentration with Easy-to-Make Thermal Metamaterials

    PubMed Central

    Chen, Fei; Yuan Lei, Dang

    2015-01-01

    The ability to harvest thermal energy and manipulate heat fluxes has recently attracted a great deal of research interest because this is critical to achieve efficient solar-to-thermal energy conversion in the technology of concentrated solar thermal collectors. Thermal metamaterials with engineered thermal conduction are often utilized to control the diffusive heat flow in ways otherwise not possible with naturally occurring materials. In this work, we adopt the transformation thermodynamics approach to design an annular fan-shaped thermal metamaterial which is capable of guiding heat fluxes and concentrating thermal energy to the central region of the metamaterial device without disturbing the temperature profile outside the structure – a fascinating and unique feature impossibly achieved with homogeneous materials. In experiment, this rationally-designed metamaterial structure demonstrates extreme heat flux compression from both line-shaped and point thermal sources with measured concentration efficiency up to 83.1%, providing the first experimental realization of our recent theoretical prediction (T. Han et al., Energy Environ. Sci., 2013, 6, 3537-3541). These unprecedented results may open up new possibilities for engineering thermal materials with desired properties that can be used for dramatically enhancing the efficiency of the existing solar thermal collectors. PMID:26109080

  9. Detecting changes in future precipitation extremes over eight river basins in China using RegCM4 downscaling

    NASA Astrophysics Data System (ADS)

    Qin, Peihua; Xie, Zhenghui

    2016-06-01

    To detect the frequency and intensity of precipitation extremes in China for the middle 21st century, simulations were conducted with the regional climate model RegCM4 forced by the global climate model GFDL_ESM2M under the middle emission scenario (RCP4.5). Compared with observed precipitation extremes for the reference period from 1982 to 2001, RegCM4 generally performed better in most river basins of China relative to GFDL. In the future period 2032-2051, more wet extremes will occur relative to the present period in most study areas, especially in southeast China while significantly less dry extremes will occur in arid and semiarid areas in northwest China. In contrast, areas in northwest China showed an increase in the trend of dry extremes (CDD) and a decrease in the trend of wet extremes (R95p and Rx5day), which might result in more drought in the future. Finally, we discuss in detail the possible reason of these processes, such as zonal wind, vertical wind, and water vapor. In the Huaihe river basin (HU), reduced south winds in summer (June-August) and a decrease of the upward vertical p velocity cause less future precipitation and might lead to changes of extreme events. We also completed correlation analysis between the precipitation extreme indices and the climate factors and found that the precipitation extremes were more sensitive to the annual and seasonal mean precipitation, total water vapor, and upward vertical wind relative to the geopotential height and 2 m temperature over most river basins in China. Perhaps the changes of some wet extremes could be verified partly through changes of annual precipitation due to their high consistence.

  10. CAN A NANOFLARE MODEL OF EXTREME-ULTRAVIOLET IRRADIANCES DESCRIBE THE HEATING OF THE SOLAR CORONA?

    SciTech Connect

    Tajfirouze, E.; Safari, H.

    2012-01-10

    Nanoflares, the basic units of impulsive energy release, may produce much of the solar background emission. Extrapolation of the energy frequency distribution of observed microflares, which follows a power law to lower energies, can give an estimation of the importance of nanoflares for heating the solar corona. If the power-law index is greater than 2, then the nanoflare contribution is dominant. We model a time series of extreme-ultraviolet emission radiance as random flares with a power-law exponent of the flare event distribution. The model is based on three key parameters: the flare rate, the flare duration, and the power-law exponent of the flare intensity frequency distribution. We use this model to simulate emission line radiance detected in 171 A, observed by Solar Terrestrial Relation Observatory/Extreme-Ultraviolet Imager and Solar Dynamics Observatory/Atmospheric Imaging Assembly. The observed light curves are matched with simulated light curves using an Artificial Neural Network, and the parameter values are determined across the active region, quiet Sun, and coronal hole. The damping rate of nanoflares is compared with the radiative losses cooling time. The effect of background emission, data cadence, and network sensitivity on the key parameters of the model is studied. Most of the observed light curves have a power-law exponent, {alpha}, greater than the critical value 2. At these sites, nanoflare heating could be significant.

  11. Climate Change and Health Risks from Extreme Heat and Air Pollution in the Eastern United States

    NASA Astrophysics Data System (ADS)

    Limaye, V.; Vargo, J.; Harkey, M.; Holloway, T.; Meier, P.; Patz, J.

    2013-12-01

    Climate change is expected to exacerbate health risks from exposure to extreme heat and air pollution through both direct and indirect mechanisms. Directly, warmer ambient temperatures promote biogenic emissions of ozone precursors and favor the formation of ground-level ozone, while an anticipated increase in the frequency of stagnant air masses will allow fine particulates to accumulate. Indirectly, warmer summertime temperatures stimulate energy demand and exacerbate polluting emissions from the electricity sector. Thus, while technological adaptations such as air conditioning can reduce risks from exposures to extreme heat, they can trigger downstream damage to air quality and public health. Through an interdisciplinary modeling effort, we quantify the impacts of climate change on ambient temperatures, summer energy demand, air quality, and public health. The first phase of this work explores how climate change will directly impact the burden of heat-related mortality. Climatic patterns, demographic trends, and epidemiologic risk models suggest that populations in the eastern United States are likely to experience an increasing heat stress mortality burden in response to rising summertime air temperatures. We use North American Regional Climate Change Assessment Program modeling data to estimate mid-century 2-meter air temperatures and humidity across the eastern US from June-August, and quantify how long-term changes in actual and apparent temperatures from present-day will affect the annual burden of heat-related mortality across this region. With the US Environmental Protection Agency's Environmental Benefits Mapping and Analysis Program, we estimate health risks using concentration-response functions, which relate temperature increases to changes in annual mortality rates. We compare mid-century summertime temperature data, downscaled using the Weather Research and Forecasting model, to 2007 baseline temperatures at a 12 km resolution in order to estimate

  12. Differences between Changes in Extreme and Mean Sea Levels and Planning Allowances for Coastal Protection for the Extremes of the Future

    NASA Astrophysics Data System (ADS)

    Woodworth, Philip; Hunter, John; Antony, Charls; Unnikrishnan, Alakkat

    2016-04-01

    Previous studies of changes in extreme sea levels around the world during the past few decades have shown that they largely parallel those in mean sea levels, although with some exceptions at individual stations or in particular regions. In the present study, we have used a much larger data set of high-frequency sea level data from a global set of tide gauges in order to investigate the reasons for the exceptions in greater detail, including the role of the major modes of climate variability. The global data set is called GESLA-2 (Global Extreme Sea Level Analysis Version 2) which contains major improvements over the earlier GESLA-1 version (Menendez and Woodworth, JGR 2010) A special study of extreme sea levels is performed using data from India which, for various reasons, are not included in GESLA-2. In addition, the much larger temporal and spatial coverage of GESLA-2 is used to further update the coastal 'allowances' for future sea level rise presented by Hunter et al. (Ocean Engineering 2013), and updated in the IPCC AR5, in which guidelines are given for raising coastal defences for a given scenario of future sea level rise at stations where the climatology of extreme sea levels is known.

  13. Future directions in two-phase flow and heat transfer in space

    NASA Technical Reports Server (NTRS)

    Bankoff, S. George

    1994-01-01

    Some areas of opportunity for future research in microgravity two-phase flow and heat transfer are pointed out. These satisfy the dual requirements of relevance to current and future needs, and scientific/engineering interest.

  14. Facing the Future: Effects of Short-Term Climate Extremes on Isoprene-Emitting and Nonemitting Poplar.

    PubMed

    Vanzo, Elisa; Jud, Werner; Li, Ziru; Albert, Andreas; Domagalska, Malgorzata A; Ghirardo, Andrea; Niederbacher, Bishu; Frenzel, Juliane; Beemster, Gerrit T S; Asard, Han; Rennenberg, Heinz; Sharkey, Thomas D; Hansel, Armin; Schnitzler, Jörg-Peter

    2015-09-01

    Isoprene emissions from poplar (Populus spp.) plantations can influence atmospheric chemistry and regional climate. These emissions respond strongly to temperature, [CO2], and drought, but the superimposed effect of these three climate change factors are, for the most part, unknown. Performing predicted climate change scenario simulations (periodic and chronic heat and drought spells [HDSs] applied under elevated [CO2]), we analyzed volatile organic compound emissions, photosynthetic performance, leaf growth, and overall carbon (C) gain of poplar genotypes emitting (IE) and nonemitting (NE) isoprene. We aimed (1) to evaluate the proposed beneficial effect of isoprene emission on plant stress mitigation and recovery capacity and (2) to estimate the cumulative net C gain under the projected future climate. During HDSs, the chloroplastidic electron transport rate of NE plants became impaired, while IE plants maintained high values similar to unstressed controls. During recovery from HDS episodes, IE plants reached higher daily net CO2 assimilation rates compared with NE genotypes. Irrespective of the genotype, plants undergoing chronic HDSs showed the lowest cumulative C gain. Under control conditions simulating ambient [CO2], the C gain was lower in the IE plants than in the NE plants. In summary, the data on the overall C gain and plant growth suggest that the beneficial function of isoprene emission in poplar might be of minor importance to mitigate predicted short-term climate extremes under elevated [CO2]. Moreover, we demonstrate that an analysis of the canopy-scale dynamics of isoprene emission and photosynthetic performance under multiple stresses is essential to understand the overall performance under proposed future conditions. PMID:26162427

  15. Facing the Future: Effects of Short-Term Climate Extremes on Isoprene-Emitting and Nonemitting Poplar1

    PubMed Central

    Vanzo, Elisa; Jud, Werner; Li, Ziru; Albert, Andreas; Domagalska, Malgorzata A.; Ghirardo, Andrea; Niederbacher, Bishu; Frenzel, Juliane; Beemster, Gerrit T.S.; Asard, Han; Rennenberg, Heinz; Sharkey, Thomas D.; Hansel, Armin; Schnitzler, Jörg-Peter

    2015-01-01

    Isoprene emissions from poplar (Populus spp.) plantations can influence atmospheric chemistry and regional climate. These emissions respond strongly to temperature, [CO2], and drought, but the superimposed effect of these three climate change factors are, for the most part, unknown. Performing predicted climate change scenario simulations (periodic and chronic heat and drought spells [HDSs] applied under elevated [CO2]), we analyzed volatile organic compound emissions, photosynthetic performance, leaf growth, and overall carbon (C) gain of poplar genotypes emitting (IE) and nonemitting (NE) isoprene. We aimed (1) to evaluate the proposed beneficial effect of isoprene emission on plant stress mitigation and recovery capacity and (2) to estimate the cumulative net C gain under the projected future climate. During HDSs, the chloroplastidic electron transport rate of NE plants became impaired, while IE plants maintained high values similar to unstressed controls. During recovery from HDS episodes, IE plants reached higher daily net CO2 assimilation rates compared with NE genotypes. Irrespective of the genotype, plants undergoing chronic HDSs showed the lowest cumulative C gain. Under control conditions simulating ambient [CO2], the C gain was lower in the IE plants than in the NE plants. In summary, the data on the overall C gain and plant growth suggest that the beneficial function of isoprene emission in poplar might be of minor importance to mitigate predicted short-term climate extremes under elevated [CO2]. Moreover, we demonstrate that an analysis of the canopy-scale dynamics of isoprene emission and photosynthetic performance under multiple stresses is essential to understand the overall performance under proposed future conditions. PMID:26162427

  16. The 2010 Pakistan Flood and Russian Heat Wave: Teleconnection of Hydrometeorological Extremes

    NASA Technical Reports Server (NTRS)

    Lau, William K. M.; Kim, Kyu-Myong

    2012-01-01

    In this paper, preliminary results are presented showing that the two record-setting extreme events during 2010 summer (i.e., the Russian heat wave-wildfires and Pakistan flood) were physically connected. It is found that the Russian heat wave was associated with the development of an extraordinarily strong and prolonged extratropical atmospheric blocking event in association with the excitation of a large-scale atmospheric Rossby wave train spanning western Russia, Kazakhstan, and the northwestern China-Tibetan Plateau region. The southward penetration of upper-level vorticity perturbations in the leading trough of the Rossby wave was instrumental in triggering anomalously heavy rain events over northern Pakistan and vicinity in mid- to late July. Also shown are evidences that the Russian heat wave was amplified by a positive feedback through changes in surface energy fluxes between the atmospheric blocking pattern and an underlying extensive land region with below-normal soil moisture. The Pakistan heavy rain events were amplified and sustained by strong anomalous southeasterly flow along the Himalayan foothills and abundant moisture transport from the Bay of Bengal in connection with the northward propagation of the monsoonal intraseasonal oscillation.

  17. A modelling framework to project future climate change impacts on streamflow variability and extremes in the West River, China

    NASA Astrophysics Data System (ADS)

    Fei, Y.; Yeou-Koung, T.; Liliang, R.

    2014-09-01

    In this study, a hydrological modelling framework was introduced to assess the climate change impacts on future river flow in the West River basin, China, especially on streamflow variability and extremes. The modelling framework includes a delta-change method with the quantile-mapping technique to construct future climate forcings on the basis of observed meteorological data and the downscaled climate model outputs. This method is able to retain the signals of extreme weather events, as projected by climate models, in the constructed future forcing scenarios. Fed with the historical and future forcing data, a large-scale hydrologic model (the Variable Infiltration Capacity model, VIC) was executed for streamflow simulations and projections at daily time scales. A bootstrapping resample approach was used as an indirect alternative to test the equality of means, standard deviations and the coefficients of variation for the baseline and future streamflow time series, and to assess the future changes in flood return levels. The West River basin case study confirms that the introduced modelling framework is an efficient effective tool to quantify streamflow variability and extremes in response to future climate change.

  18. Spatial impacts of heat waves in mortality. Evaluating current risks and future threats

    NASA Astrophysics Data System (ADS)

    Andrade, H.; Canario, P.; Nogueira, H.

    2009-09-01

    Impacts of heat waves in morbidity and mortality are largely known. Climate Change is expected to increase the climate health impacts in summer while the winter will be probably favored. The health impacts of extreme thermal events are mainly studied at a national or regional level, considering macro or mesoscale thermal features. But it can be assumed that local variations in mortality must exist, associated, in one hand, with local climatic differences, due to features such as land use and urbanization and, in other hand, with vulnerability factors (depending on demographic and socioeconomic characteristics of populations). A model of hazard - vulnerability - risk was developed, to analyze the spatial variations of mortality in extreme thermal events, at the level of city district, in the Lisbon metropolitan area (Portugal). In that model, risk is considered as the product of hazard and vulnerability. Daily mortality data by sex, age and cause of death was supplied by the Health National Authority. The research is yet on-going. In our model, hazard is represented mainly by temperature and air pollution (the influence of other atmospheric variables that affect the human energy balance, such as solar radiation and wind speed should be tested too). Small scale variation of meteorological features, in extreme thermal events, were simulated with a Regional Atmospheric Model (Brazilian Regional Atmospheric Modeling System) and the results were validated and calibrated using observation data from an urban network of termo-higrometers placed in sites with different urban characteristics. Vulnerability is a result on personal sensitivity and exposure. Personal sensitivity is assessed considering individual constitutional and demographic factors as well as socio, cultural and economic variables. Daily mobility determines the population exposure to heat. Since many of these variables are redundant, a set of indicators, including a multiple deprivation index, was used. A

  19. California heat waves in the present and future

    NASA Astrophysics Data System (ADS)

    Gershunov, Alexander; Guirguis, Kristen

    2012-09-01

    Current and projected heat waves are examined over California and its sub-regions in observations and downscaled global climate model (GCM) simulations. California heat wave activity falls into two distinct types: (1) typically dry daytime heat waves and (2) humid nighttime-accentuated events (Type I and Type II, respectively). The four GCMs considered project Type II heat waves to intensify more with climate change than the historically characteristic Type I events, although both types are projected to increase. This trend is already clearly observed and simulated to various degrees over all sub-regions of California. Part of the intensification in heat wave activity is due directly to mean warming. However, when one considers non-stationarity in daily temperature variance, desert heat waves are expected to become progressively and relatively less intense while coastal heat waves are projected to intensify even relative to the background warming. This result generally holds for both types of heat waves across models. Given the high coastal population density and low acclimatization to heat, especially humid heat, this trend bodes ill for coastal communities, jeopardizing public health and stressing energy resources.

  20. Estimates of future flow, including extremes, of the Columbia River headwaters

    NASA Astrophysics Data System (ADS)

    Bürger, G.; Schulla, J.; Werner, A. T.

    2011-10-01

    Streamflow projections, including extremes, for the 2050s for the Columbia River headwaters above Donald are obtained by downscaling four regional climate models of the North American Regional Climate Change Assessment Program (NARCCAP) suite and subsequent driving of a hydrologic model. We employ the entire model chain from global and regional climate models, station-based statistical downscaling, and a fully distributed, physically based hydrologic model and verify the results against observed streamflow. The performance is model dependent but is generally encouraging enough to justify the application of the climate scenarios. A general warming of about 2°C is projected and, on average, slightly drier conditions, especially in late summer. We find evidence that the projected changes are elevation dependent and relatively small scale, with decreasing signals with higher elevations. All models project a shift of the hydrograph toward a more rain-fed regime, with peak flows occurring in June instead of July. Annual peak flow is projected to not increase, and August low flow decreases in all four models. With nonshrinking (static) glaciers, relatively high melting rates are simulated for August and September that partly compensate for the shifted hydrograph; this enhanced glacier melt is also detected in simulated historic Columbia headwater flow. The static approximation is supported by a heuristic seasonal sensitivity analysis that suggests a moderate average areal glacier recession of about 10% for the midcentury. We discuss the need for a dynamic glacier component for a refined assessment of future drought risk.

  1. In-vehicle extremity injuries from improvised explosive devices: current and future foci

    PubMed Central

    Ramasamy, Arul; Masouros, Spyros D.; Newell, Nicolas; Hill, Adam M.; Proud, William G.; Brown, Katherine A.; Bull, Anthony M. J.; Clasper, Jon C.

    2011-01-01

    The conflicts in Iraq and Afghanistan have been epitomized by the insurgents' use of the improvised explosive device against vehicle-borne security forces. These weapons, capable of causing multiple severely injured casualties in a single incident, pose the most prevalent single threat to Coalition troops operating in the region. Improvements in personal protection and medical care have resulted in increasing numbers of casualties surviving with complex lower limb injuries, often leading to long-term disability. Thus, there exists an urgent requirement to investigate and mitigate against the mechanism of extremity injury caused by these devices. This will necessitate an ontological approach, linking molecular, cellular and tissue interaction to physiological dysfunction. This can only be achieved via a collaborative approach between clinicians, natural scientists and engineers, combining physical and numerical modelling tools with clinical data from the battlefield. In this article, we compile existing knowledge on the effects of explosions on skeletal injury, review and critique relevant experimental and computational research related to lower limb injury and damage and propose research foci required to drive the development of future mitigation technologies. PMID:21149353

  2. In-vehicle extremity injuries from improvised explosive devices: current and future foci.

    PubMed

    Ramasamy, Arul; Masouros, Spyros D; Newell, Nicolas; Hill, Adam M; Proud, William G; Brown, Katherine A; Bull, Anthony M J; Clasper, Jon C

    2011-01-27

    The conflicts in Iraq and Afghanistan have been epitomized by the insurgents' use of the improvised explosive device against vehicle-borne security forces. These weapons, capable of causing multiple severely injured casualties in a single incident, pose the most prevalent single threat to Coalition troops operating in the region. Improvements in personal protection and medical care have resulted in increasing numbers of casualties surviving with complex lower limb injuries, often leading to long-term disability. Thus, there exists an urgent requirement to investigate and mitigate against the mechanism of extremity injury caused by these devices. This will necessitate an ontological approach, linking molecular, cellular and tissue interaction to physiological dysfunction. This can only be achieved via a collaborative approach between clinicians, natural scientists and engineers, combining physical and numerical modelling tools with clinical data from the battlefield. In this article, we compile existing knowledge on the effects of explosions on skeletal injury, review and critique relevant experimental and computational research related to lower limb injury and damage and propose research foci required to drive the development of future mitigation technologies. PMID:21149353

  3. The heat goes on—changes in indices of hot extremes in Poland

    NASA Astrophysics Data System (ADS)

    Graczyk, Dariusz; Pińskwar, Iwona; Kundzewicz, Zbigniew W.; Hov, Øystein; Førland, Eirik J.; Szwed, Małgorzata; Choryński, Adam

    2016-04-01

    On the basis of temperature observations at 60 meteorological stations in Poland, changes in the indices associated with the presence of extremely high air temperatures were examined. Indices associated with heat waves, such as the number of hot days (T max ≥30 °C) in the summer months (June, July, August) and beyond the summer months (May, September), the number of extremely hot days (T max ≥35 °C), the duration of the longest hot spell in the year, as well as the number of tropical nights (T min ≤20 °C) were calculated. Spatial distribution of change rate in days per decade for the studied indices as well as the significance level of the observed trends is illustrated. Also current values of the studied indices (for 1991-2013) are examined and compared with the reference period, 1961-1990. For eight of 11 analysed indexes, increase has been detected in last decades with the help of the Mann-Kendall test at a significance level ≥0.05 or better, for a large group of stations. Statistically significant increases of the number of hot days in summer, the number of tropical nights in a year, and duration of the longest hot spell in summer were found for more than half of the stations. Distinct changes in the duration of heat waves were also noted. In 1961-1990, the longest hot spell lasted for 10 days while in 1991-2013, there were many hot spells longer than that, while the longest hot spell recorded in this period lasted for 17 days. Beyond summer, changes in the number of hot days were smaller. In May, a statistically significant increase was recorded for only three stations, while in September the downward trend was dominating and for eight stations it was statistically significant.

  4. Reply to Rhines and Huybers: Changes in the Frequency of Extreme Summer Heat

    NASA Technical Reports Server (NTRS)

    Hansen, James; Sato, Makiko; Ruedy, Reto

    2013-01-01

    Rhines and Huybers are correct that the decreasing number of measurement stations in recent years contributed slightly to our calculated increase of extreme summer mean temperature anomalies. However, the increased frequency of extreme heat anomalies is accounted for mainly by (i) higher mean temperature of recent decades relative to the base period 1951-1980, and (ii) the continuing upward temperature trend during recent decades. The effect of decreasing stations is shown by comparing our prior analysis with results using only stations with data records in both the base period and recent years (Fig. 1). The distribution is noisier, and the area with temperature anomaly exceeding three SDs during 2001-2011 decreases from 9.6 to 9.3% for the reduced number of stations (1,886 rather than 6,147), but our conclusions are not changed qualitatively. The temperature anomaly distribution shifts to the right and broadens because it is defined relative to a fixed (1951-1980) base period, during which global temperatures were within the Holocene range. We argue on the basis of accelerating ice loss from Greenland and Antarctica and rapidly rising sea level (now exceeding 3 mm/y or 3 m per millennium) that temperatures in the early 21st century are already above the Holocene range, and thus use of a base period preceding the rapid warming of the past three decades has merit.

  5. Understanding future projected changes and trends in extreme precipitation and streamflow events in ten Polish catchments

    NASA Astrophysics Data System (ADS)

    Meresa, Hadush; Romanowicz, Renata; Napiorkoski, Jaroslaw

    2016-04-01

    The aim of the study is to investigate methods of trend detection in hydro-climatic high and low indices using novel and conventional tools, for future climate projections in the periods 2021-2050 and 2071-2100. The climate meteorological projections are obtained from regional climate models or/and global circulation models forced with IPCC SRES A1B, RCP4.5 and RCP8.5 emission scenarios. The study area includes ten catchments in Poland. The catchments have diverse hydro-climatic conditions. They are covered mostly by forest and are semi-natural. The flood regime of all the catchments is driven either by rainfall and/or snow-melt. Streamflow projections are provided by running the HBV hydrological model, coupled with climate models for the catchments. The trends are analyzed using a conventional Modified Mann Kendall statistical approach, a time frequency approach based on wavelet discrete transform (DWT) and the Dynamic Harmonic Regression (DHR) method. We address the problems of auto-correlation, seasonality and inter-annual variability of the derived indices. A Modified Mann Kendall (MMK) method is applied to cope with the autocorrelation of the time series. The DHR method is based on the unobserved component approach. Together with estimates of the components, the uncertainty of the estimates is also calculated. The results of the DHR analysis (trend) are compared with the calculated MMK and DWT trends. Among other indices we study the temporal patterns of the Standardized Precipitation Index (SPI), Standardized Runoff Index (SRI) and Standardized Evapotranspiration Index (SPEI), as well as Maximum Annual Flows and Minimum Annual Flows. The results indicate that changes in the trends of the projected indices are more conservative when DHR methods are applied than conventional trend techniques. The wavelet-based approach is the most subjective and gives the least conservative trend estimates. Trends indicate an increase in the amount of precipitation, followed by

  6. Future changes in precipitation and impacts on extreme streamflow over Amazonian sub-basins

    NASA Astrophysics Data System (ADS)

    Guimberteau, M.; Ronchail, J.; Espinoza, J.; Lengaigne, M.; Sultan, B.; Polcher, J.; Drapeau, G.; Guyot, J.; Ducharne, A.; Ciais, P.

    2013-05-01

    Because of climate change, much attention is drawn on the Amazon River basin whose hydrology has already been strongly affected by extreme events during the past 20 years. Hydrological annual extreme variations (i.e. low/high flows) associated to precipitation (and evapotranspiration) changes are investigated over the Amazon River sub-basins using the land surface model ORCHIDEE and a multi model approach. Climate change scenarios from up to eight AR4 Global Climate Models based on 3 emission scenarios were used to build future hydrological projections in the region, for two periods of the 21st century. For the middle of the century under the SRESA1B scenario, no change is found in high flow on the main stem of the Amazon River (Óbidos station) but a systematic discharge decrease is simulated during the recession period leading to a 10% low-flow decrease. Contrasted discharge variations are pointed out depending on the location in the basin. In the western upper part of the basin which undergoes an annual persistent increase in precipitation, high flow shows a 7% relative increase for the middle of the 21st century and the signal is enhanced for the end of the century (12%). By contrast, simulated precipitation decreases during the dry seasons over the southern, eastern and northern parts of the basin lead to significant low-flow decrease in several stations, especially in the Xingu River where it reaches -50%, associated with a 9% reduction in the runoff coefficient. A 18% high-flow decrease is also found in this river. In the North, the low-flow decrease becomes higher towards the east: a 55% significant decrease in the eastern Branco River is associated with a 13% reduction in the runoff coefficient. The estimation of the streamflow elasticity to precipitation indicates that southern sub-basins (except for the mountainous Beni River) that have low runoff coefficients will become more responsive to precipitation change (with a 5 to near 35% increase in

  7. Future changes in precipitation and impacts on extreme streamflow over Amazonian sub-basins

    NASA Astrophysics Data System (ADS)

    Guimberteau, M.; Ronchail, J.; Espinoza, J. C.; Lengaigne, M.; Sultan, B.; Polcher, J.; Drapeau, G.; Guyot, J.-L.; Ducharne, A.; Ciais, P.

    2013-03-01

    Because of climate change, much attention is drawn to the Amazon River basin, whose hydrology has already been strongly affected by extreme events during the past 20 years. Hydrological annual extreme variations (i.e. low/high flows) associated with precipitation (and evapotranspiration) changes are investigated over the Amazon River sub-basins using the land surface model ORCHIDEE and a multimodel approach. Climate change scenarios from up to eight AR4 Global Climate Models based on three emission scenarios were used to build future hydrological projections in the region, for two periods of the 21st century. For the middle of the century under the SRESA1B scenario, no change is found in high flow on the main stem of the Amazon River (Óbidos station), but a systematic discharge decrease is simulated during the recession period, leading to a 10% low-flow decrease. Contrasting discharge variations are pointed out depending on the location in the basin. In the western upper part of the basin, which undergoes an annual persistent increase in precipitation, high flow shows a 7% relative increase for the middle of the 21st century and the signal is enhanced for the end of the century (12%). By contrast, simulated precipitation decreases during the dry seasons over the southern, eastern and northern parts of the basin lead to significant low-flow decrease at several stations, especially in the Xingu River, where it reaches -50%, associated with a 9% reduction in the runoff coefficient. A 18% high-flow decrease is also found in this river. In the north, the low-flow decrease becomes higher toward the east: a 55% significant decrease in the eastern Branco River is associated with a 13% reduction in the runoff coefficient. The estimation of the streamflow elasticity to precipitation indicates that southern sub-basins (except for the mountainous Beni River), that have low runoff coefficients, will become more responsive to precipitation change (with a 5 to near 35% increase

  8. Solar assisted heat pumps: A possible wave of the future

    NASA Technical Reports Server (NTRS)

    Smetana, F. O.

    1976-01-01

    With the higher costs of electric power and the widespread interest to use solar energy to reduce the national dependence on fossil fuels, heat pumps are examined to determine their suitability for use with solar energy systems.

  9. Impacts of the Future Changes in Extreme Events on the Regional Crop Yield in Turkey

    NASA Astrophysics Data System (ADS)

    An, Nazan; Turp, M. Tufan; Ozturk, Tugba; Kurnaz, M. Levent

    2016-04-01

    The changes in extreme events caused by climate change have the greatest impact on agricultural sector specifically crop yield. Therefore, it requires a clear understanding of how extreme events affect the crop yield and how it causes high economic losses. In this research, we cover the relationship between extreme events and the crop yield in Turkey for the period of 2020 - 2045 with respect to 1980 - 2005. We focus on the role of those extreme event causing natural disasters on the regional crop yield. This research comprises 2 parts. In the first part, the projection is performed according to the business as usual scenario of IPCC, RCP8.5, via the RegCM4.4 in order to obtain extreme event indices required for the crop assessment. In the second part, the crop yield and the extreme event indices are combined by applying the econometric analysis in order to see the relationship between natural disasters and crop yield. The risks for crop yield caused by the extreme events are estimated and interpreted. This study aims to assess the effect of frequency of expected extreme events on the crop yield at the cropland of Turkey. This research has been supported by Boǧaziçi University Research Fund Grant Number 10421.

  10. Potential Impacts of Future Warming and Land Use Changes on Intra-Urban Heat Exposure in Houston, Texas

    PubMed Central

    Conlon, Kathryn; Monaghan, Andrew; Hayden, Mary; Wilhelmi, Olga

    2016-01-01

    Extreme heat events in the United States are projected to become more frequent and intense as a result of climate change. We investigated the individual and combined effects of land use and warming on the spatial and temporal distribution of daily minimum temperature (Tmin) and daily maximum heat index (HImax) during summer in Houston, Texas. Present-day (2010) and near-future (2040) parcel-level land use scenarios were embedded within 1-km resolution land surface model (LSM) simulations. For each land use scenario, LSM simulations were conducted for climatic scenarios representative of both the present-day and near-future periods. LSM simulations assuming present-day climate but 2040 land use patterns led to spatially heterogeneous temperature changes characterized by warmer conditions over most areas, with summer average increases of up to 1.5°C (Tmin) and 7.3°C (HImax) in some newly developed suburban areas compared to simulations using 2010 land use patterns. LSM simulations assuming present-day land use but a 1°C temperature increase above the urban canopy (consistent with warming projections for 2040) yielded more spatially homogeneous metropolitan-wide average increases of about 1°C (Tmin) and 2.5°C (HImax), respectively. LSM simulations assuming both land use and warming for 2040 led to summer average increases of up to 2.5°C (Tmin) and 8.3°C (HImax), with the largest increases in areas projected to be converted to residential, industrial and mixed-use types. Our results suggest that urbanization and climate change may significantly increase the average number of summer days that exceed current threshold temperatures for initiating a heat advisory for metropolitan Houston, potentially increasing population exposure to extreme heat. PMID:26863298

  11. Potential Impacts of Future Warming and Land Use Changes on Intra-Urban Heat Exposure in Houston, Texas.

    PubMed

    Conlon, Kathryn; Monaghan, Andrew; Hayden, Mary; Wilhelmi, Olga

    2016-01-01

    Extreme heat events in the United States are projected to become more frequent and intense as a result of climate change. We investigated the individual and combined effects of land use and warming on the spatial and temporal distribution of daily minimum temperature (Tmin) and daily maximum heat index (HImax) during summer in Houston, Texas. Present-day (2010) and near-future (2040) parcel-level land use scenarios were embedded within 1-km resolution land surface model (LSM) simulations. For each land use scenario, LSM simulations were conducted for climatic scenarios representative of both the present-day and near-future periods. LSM simulations assuming present-day climate but 2040 land use patterns led to spatially heterogeneous temperature changes characterized by warmer conditions over most areas, with summer average increases of up to 1.5°C (Tmin) and 7.3°C (HImax) in some newly developed suburban areas compared to simulations using 2010 land use patterns. LSM simulations assuming present-day land use but a 1°C temperature increase above the urban canopy (consistent with warming projections for 2040) yielded more spatially homogeneous metropolitan-wide average increases of about 1°C (Tmin) and 2.5°C (HImax), respectively. LSM simulations assuming both land use and warming for 2040 led to summer average increases of up to 2.5°C (Tmin) and 8.3°C (HImax), with the largest increases in areas projected to be converted to residential, industrial and mixed-use types. Our results suggest that urbanization and climate change may significantly increase the average number of summer days that exceed current threshold temperatures for initiating a heat advisory for metropolitan Houston, potentially increasing population exposure to extreme heat. PMID:26863298

  12. A non-equilibrium model for soil heating and moisture transport during extreme surface heating: the soil (heat-moisture-vapor) HMV-Model Version 1

    NASA Astrophysics Data System (ADS)

    Massman, W. J.

    2015-11-01

    Increased use of prescribed fire by land managers and the increasing likelihood of wildfires due to climate change require an improved modeling capability of extreme heating of soils during fires. This issue is addressed here by developing and testing the soil (heat-moisture-vapor) HMV-model, a 1-D (one-dimensional) non-equilibrium (liquid-vapor phase change) model of soil evaporation that simulates the coupled simultaneous transport of heat, soil moisture, and water vapor. This model is intended for use with surface forcing ranging from daily solar cycles to extreme conditions encountered during fires. It employs a linearized Crank-Nicolson scheme for the conservation equations of energy and mass and its performance is evaluated against dynamic soil temperature and moisture observations, which were obtained during laboratory experiments on soil samples exposed to surface heat fluxes ranging between 10 000 and 50 000 W m-2. The Hertz-Knudsen equation is the basis for constructing the model's non-equilibrium evaporative source term. Some unusual aspects of the model that were found to be extremely important to the model's performance include (1) a dynamic (temperature and moisture potential dependent) condensation coefficient associated with the evaporative source term, (2) an infrared radiation component to the soil's thermal conductivity, and (3) a dynamic residual soil moisture. This last term, which is parameterized as a function of temperature and soil water potential, is incorporated into the water retention curve and hydraulic conductivity functions in order to improve the model's ability to capture the evaporative dynamics of the strongly bound soil moisture, which requires temperatures well beyond 150 °C to fully evaporate. The model also includes film flow, although this phenomenon did not contribute much to the model's overall performance. In general, the model simulates the laboratory-observed temperature dynamics quite well, but is less precise (but

  13. Effect of Temperature Shock and Inventory Surprises on Natural Gas and Heating Oil Futures Returns

    PubMed Central

    Hu, John Wei-Shan; Lin, Chien-Yu

    2014-01-01

    The aim of this paper is to examine the impact of temperature shock on both near-month and far-month natural gas and heating oil futures returns by extending the weather and storage models of the previous study. Several notable findings from the empirical studies are presented. First, the expected temperature shock significantly and positively affects both the near-month and far-month natural gas and heating oil futures returns. Next, significant temperature shock has effect on both the conditional mean and volatility of natural gas and heating oil prices. The results indicate that expected inventory surprises significantly and negatively affects the far-month natural gas futures returns. Moreover, volatility of natural gas futures returns is higher on Thursdays and that of near-month heating oil futures returns is higher on Wednesdays than other days. Finally, it is found that storage announcement for natural gas significantly affects near-month and far-month natural gas futures returns. Furthermore, both natural gas and heating oil futures returns are affected more by the weighted average temperature reported by multiple weather reporting stations than that reported by a single weather reporting station. PMID:25133233

  14. The effect of future reduction in aerosol emissions on climate extremes in China

    NASA Astrophysics Data System (ADS)

    Wang, Zhili; Lin, Lei; Yang, Meilin; Xu, Yangyang

    2016-01-01

    This study investigates the effect of reduced aerosol emissions on projected temperature and precipitation extremes in China during 2031-2050 and 2081-2100 relative to present-day conditions using the daily data output from the Community Earth System Model ensemble simulations under the Representative Concentration Pathway (RCP) 8.5 with an applied aerosol reduction and RCP8.5 with fixed 2005 aerosol emissions (RCP8.5_FixA) scenarios. The reduced aerosol emissions of RCP8.5 magnify the warming effect due to greenhouse gases (GHG) and lead to significant increases in temperature extremes, such as the maximum of daily maximum temperature (TXx), minimum of daily minimum temperature (TNn), and tropical nights (TR), and precipitation extremes, such as the maximum 5-day precipitation amount, number of heavy precipitation days, and annual total precipitation from days ˃95th percentile, in China. The projected TXx, TNn, and TR averaged over China increase by 1.2 ± 0.2 °C (4.4 ± 0.2 °C), 1.3 ± 0.2 °C (4.8 ± 0.2 °C), and 8.2 ± 1.2 (30.9 ± 1.4) days, respectively, during 2031-2050 (2081-2100) under the RCP8.5_FixA scenario, whereas the corresponding values are 1.6 ± 0.1 °C (5.3 ± 0.2 °C), 1.8 ± 0.2 °C (5.6 ± 0.2 °C), and 11.9 ± 0.9 (38.4 ± 1.0) days under the RCP8.5 scenario. Nationally averaged increases in all of those extreme precipitation indices above due to the aerosol reduction account for more than 30 % of the extreme precipitation increases under the RCP8.5 scenario. Moreover, the aerosol reduction leads to decreases in frost days and consecutive dry days averaged over China. There are great regional differences in changes of climate extremes caused by the aerosol reduction. When normalized by global mean surface temperature changes, aerosols have larger effects on temperature and precipitation extremes over China than GHG.

  15. Enhancing Extreme Heat Health-Related Intervention and Preparedness Activities Using Remote Sensing Analysis of Daily Surface Temperature, Surface Observation Networks and Ecmwf Reanalysis

    NASA Astrophysics Data System (ADS)

    Garcia, R. L.; Booth, J.; Hondula, D.; Ross, K. W.; Stuyvesant, A.; Alm, G.; Baghel, E.

    2015-12-01

    Extreme heat causes more human fatalities in the United States than any other natural disaster, elevating the concern of heat-related mortality. Maricopa County Arizona is known for its high heat index and its sprawling metropolitan complex which makes this region a perfect candidate for human health research. Individuals at higher risk are unequally spatially distributed, leaving the poor, homeless, non-native English speakers, elderly, and the socially isolated vulnerable to heat events. The Arizona Department of Health Services, Arizona State University and NASA DEVELOP LaRC are working to establish a more effective method of placing hydration and cooling centers in addition to enhancing the heat warning system to aid those with the highest exposure. Using NASA's Earth Observation Systems from Aqua and Terra satellites, the daily spatial variability within the UHI was quantified over the summer heat seasons from 2005 - 2014, effectively establishing a remotely sensed surface temperature climatology for the county. A series of One-way Analysis of Variance revealed significant differences between daily surface temperature averages of the top 30% of census tracts within the study period. Furthermore, synoptic upper tropospheric circulation patterns were classified to relate surface weather types and heat index. The surface weather observation networks were also reviewed for analyzing the veracity of the other methods. The results provide detailed information regarding nuances within the UHI effect and will allow pertinent recommendations regarding the health department's adaptive capacity. They also hold essential components for future policy decision-making regarding appropriate locations for cooling centers and efficient warning systems.

  16. Toward a Quantitative Estimate of Future Heat Wave Mortality under Global Climate Change

    PubMed Central

    Peng, Roger D.; Bobb, Jennifer F.; Tebaldi, Claudia; McDaniel, Larry; Bell, Michelle L.; Dominici, Francesca

    2011-01-01

    Background Climate change is anticipated to affect human health by changing the distribution of known risk factors. Heat waves have had debilitating effects on human mortality, and global climate models predict an increase in the frequency and severity of heat waves. The extent to which climate change will harm human health through changes in the distribution of heat waves and the sources of uncertainty in estimating these effects have not been studied extensively. Objectives We estimated the future excess mortality attributable to heat waves under global climate change for a major U.S. city. Methods We used a database comprising daily data from 1987 through 2005 on mortality from all nonaccidental causes, ambient levels of particulate matter and ozone, temperature, and dew point temperature for the city of Chicago, Illinois. We estimated the associations between heat waves and mortality in Chicago using Poisson regression models. Results Under three different climate change scenarios for 2081–2100 and in the absence of adaptation, the city of Chicago could experience between 166 and 2,217 excess deaths per year attributable to heat waves, based on estimates from seven global climate models. We noted considerable variability in the projections of annual heat wave mortality; the largest source of variation was the choice of climate model. Conclusions The impact of future heat waves on human health will likely be profound, and significant gains can be expected by lowering future carbon dioxide emissions. PMID:21193384

  17. Back to the Future -Precipitation Extremes, Climate Variability, Environmental Planning and Adaptation

    NASA Astrophysics Data System (ADS)

    Barros, A. P.

    2008-12-01

    --"The last major climatic oscillation peak was about 1856, or 74 years ago. Practically all of our important railroad and public highway work has been done since that time. Most of our parks systems driveways, and roads of all type for auto travel, in the various States, have been completed within the past 30 years, namely, beginning at the very lowest point of our climatic swing (1900-1910). There is every reason to believe, therefore, as the next 20 years comes on apace, we will witness considerable damage to work done during the past regime of weather."-- Schuman, 1931 At the beginning of the 21st century, as at the beginning of the 20th century, the fundamental question is whether the nation is more prepared for natural disasters today than it was eight decades ago. Indeed, the question is whether the best science, engineering and policy tools are in place to prepare for and respond to extreme events. Changes in the risk and magnitude of extreme precipitation events rank among the most studied impacts, and indicators (symptoms) of climatic variations. Extreme precipitation translates generally into extreme flooding, landslides, collapse of lifeline infrastructure, and the breakdown of public health services among others. In approaching the problem of quantifying the risk and magnitude of extreme precipitation events, there are two major challenges: 1) it is difficult to characterize "observed" (20th century) conditions due to the lack of long-term observations - i.e., short and incomplete historical records; and 2) it is difficult to characterize "predicted" (21st century) conditions due to the lack of skill of precipitation forecasts at spatial and temporal scales meaningful for impact studies, and the short-duration of climate model simulations themselves. The first challenge translates in estimating the probability of occurrence (rare) and magnitude (very large) of events that may have not happened yet. The second challenge is that of quantifying

  18. Responding to the Effects of Extreme Heat: Baltimore City's Code Red Program.

    PubMed

    Martin, Jennifer L

    2016-01-01

    Heat response plans are becoming increasingly more common as US cities prepare for heat waves and other effects of climate change. Standard elements of heat response plans exist, but plans vary depending on geographic location and distribution of vulnerable populations. Because heat events vary over time and affect populations differently based on vulnerability, it is difficult to compare heat response plans and evaluate responses to heat events. This article provides an overview of the Baltimore City heat response plan, the Code Red program, and discusses the city's response to the 2012 Ohio Valley/Mid Atlantic Derecho, a complex heat event. Challenges with and strategies for evaluating the program are reviewed and shared. PMID:27081886

  19. Extreme Heat Wave over European Russia in Summer 2010: Anomaly or a Manifestation of Climatic Trend?

    NASA Astrophysics Data System (ADS)

    Razuvaev, V.; Groisman, P. Y.; Bulygina, O.; Borzenkova, I.

    2010-12-01

    Extraordinary temperature anomalies over European Russia (ER) in summer 2010 raised a legitimate question in the title of this presentation. A 60-days-long hot anticyclonic weather system with daily temperature anomalies as high as +10K and no or negligible amount of rainfall first decimated crops in the forest-steppe zone of ER, gradually dried wetlands in the forest zone and, finally, caused numerous natural and anthropogenic fires that at the time of this abstract preparation have not yet been extinguished. The extreme heat, lack of precipitation, and forest fires have caused hundreds of deaths and multimillion dollars in property losses. Indirect losses of lives due to this weather anomaly, with the ensuing fires and related air pollution, as well as the absence of air conditioning in apartments has yet to be estimated. The center of European Russia was well covered by meteorological observations for the past 130 years. These data, historical weather records (yearbooks or "letopisi" , which were carried on in the major Russian monasteries), and finally, dendroclimatological information, all show that this summer temperature anomaly was well above all known extremes in the past 1000 years. Like ocean waves and ocean tides, weather and climate variability go together strengthening (or mitigating) each other. We shall show the precursors of the current outbreak using principally the most accurate meteorological records of the past century updated to 2009 (at the Session, the 2010 data will also be presented). While a careful analyses of these records and thoughtful analyses of recent similar temperature outbreaks in Western Europe could not prevent the occurrence of this disaster, the lessons learned from these analyses (a) would warn about its increasing probability and (b) mitigation and adaptation measures could well be made to reduce its negative consequences. Among our arguments are: (1)There is a century-long tendency of reduction of equator minus pole

  20. Double Exposure and the Climate Gap: Changing demographics and extreme heat in Ciudad Juárez, Mexico

    PubMed Central

    Collins, Timothy W.; McDonald, Yolanda J.; Aldouri, Raed; Aboargob, Faraj; Eldeb, Abdelatif; Aguilar, María de Lourdes Romo; Velázquez-Angulo, Juárez Gilberto

    2013-01-01

    Scholars have recognized a climate gap, wherein poor communities face disproportionate impacts of climate change. Others have noted that climate change and economic globalization may mutually affect a region or social group, leading to double exposure. This paper investigates how current and changing patterns of neighborhood demographics are associated with extreme heat in the border city of Juárez, Mexico. Many Juárez neighborhoods are at-risk to triple exposures, in which residents suffer due to the conjoined effects of the global recession, drug war violence, and extreme heat. Due to impacts of the recession on maquiladora employment and the explosion of drug violence (since 2008), over 75% of neighborhoods experienced decreasing population density between 2000 and 2010 and the average neighborhood saw a 40% increase in the proportion of older adults. Neighborhoods with greater drops in population density and increases in the proportion of older residents over the decade are at significantly higher risk to extreme heat, as are neighborhoods with lower population density and lower levels of education. In this context, triple exposures are associated with a climate gap that most endangers lower socioeconomic status and increasingly older aged populations remaining in neighborhoods from which high proportions of residents have departed. PMID:25642135

  1. Extremely Low Loss Phonon-Trapping Cryogenic Acoustic Cavities for Future Physical Experiments

    PubMed Central

    Galliou, Serge; Goryachev, Maxim; Bourquin, Roger; Abbé, Philippe; Aubry, Jean Pierre; Tobar, Michael E.

    2013-01-01

    Low loss Bulk Acoustic Wave devices are considered from the point of view of the solid state approach as phonon-confining cavities. We demonstrate effective design of such acoustic cavities with phonon-trapping techniques exhibiting extremely high quality factors for trapped longitudinally-polarized phonons of various wavelengths. Quality factors of observed modes exceed 1 billion, with a maximum Q-factor of 8 billion and Q × f product of 1.6 · 1018 at liquid helium temperatures. Such high sensitivities allow analysis of intrinsic material losses in resonant phonon systems. Various mechanisms of phonon losses are discussed and estimated. PMID:23823569

  2. How extreme are extremes?

    NASA Astrophysics Data System (ADS)

    Cucchi, Marco; Petitta, Marcello; Calmanti, Sandro

    2016-04-01

    High temperatures have an impact on the energy balance of any living organism and on the operational capabilities of critical infrastructures. Heat-wave indicators have been mainly developed with the aim of capturing the potential impacts on specific sectors (agriculture, health, wildfires, transport, power generation and distribution). However, the ability to capture the occurrence of extreme temperature events is an essential property of a multi-hazard extreme climate indicator. Aim of this study is to develop a standardized heat-wave indicator, that can be combined with other indices in order to describe multiple hazards in a single indicator. The proposed approach can be used in order to have a quantified indicator of the strenght of a certain extreme. As a matter of fact, extremes are usually distributed in exponential or exponential-exponential functions and it is difficult to quickly asses how strong was an extreme events considering only its magnitude. The proposed approach simplify the quantitative and qualitative communication of extreme magnitude

  3. Heat supply from municipal solid waste incineration plants in Japan: Current situation and future challenges.

    PubMed

    Tabata, Tomohiro; Tsai, Peii

    2016-02-01

    The use of waste-to-energy technology as part of a municipal solid waste management strategy could reduce the use of fossil fuels and contribute to prevention of global warming. In this study, we examined current heat and electricity production by incineration plants in Japan for external use. Herein, we discuss specific challenges to the promotion of heat utilisation and future municipal solid waste management strategies. We conducted a questionnaire survey to determine the actual conditions of heat production by incineration plants. From the survey results, information of about 498 incineration plants was extracted. When we investigated the relationship between heat production for external use and population density where incineration plants were located, we found that regions with a population density <1000 persons (km(2))(-1) produce <500 MJ t(-1) of heat. We also found that external use of such energy for factories, markets, and related use, was noted in cities with a population density of 2000 to 4000 persons (km(2))(-1). Several incineration plants have poor performance for heat production because there are few facilities near them to provide demand for the energy. This is the result of redundant capacity, and is reflected in the heat production performance. Given these results, we discussed future challenges to creating energy demand around incineration plants where there is presently none. We also examined the challenges involved in increasing heat supply beyond the present situation. PMID:26628053

  4. Charging studies of heat packs using parabolic dish solar energy concentrator for extreme conditions

    NASA Astrophysics Data System (ADS)

    Kumar, Rohitash; Vyas, Sumita; Kumar, Ravindra; Dixit, Ambesh

    2016-05-01

    Parabolic dish solar energy concentrator with aperture diameter 1.4 m and focal length 0.32 m is designed and fabricated to charge and store solar thermal energy in phase change material (PCM) based heat packs. Overall heat loss factor, heat duty, over all thermal efficiency, and optical efficiency factor are calculated using water sensible heating and cooling tests and values are 16.11 W m-2 K-1, 546.9 W, 49.2% and 0.62 respectively. The performance characteristic curve is generated using these parameters to understand its performance at different ambient temperatures and solar insolation. The fabricated concentrator has been used to charge 16 PCM heat packs with 150 g PCM in each heat pack, which took about 35 minutes for complete charging of PCM heat packs at average ambient temperature 39 °C and solar radiation flux density 715 W m-2 K-1. The charged heat packs are subjected to discharge studies at average ambient temperature about - 7 °C and observed heat release in the temperature range of 48 to 40 °C for 50 minutes, suggesting its applications for comfort and therapeutic applications in high altitude areas.

  5. Projecting Future Heat-Related Mortality under Climate Change Scenarios: A Systematic Review

    PubMed Central

    Barnett, Adrian Gerard; Wang, Xiaoming; Vaneckova, Pavla; FitzGerald, Gerard; Tong, Shilu

    2011-01-01

    Background: Heat-related mortality is a matter of great public health concern, especially in the light of climate change. Although many studies have found associations between high temperatures and mortality, more research is needed to project the future impacts of climate change on heat-related mortality. Objectives: We conducted a systematic review of research and methods for projecting future heat-related mortality under climate change scenarios. Data sources and extraction: A literature search was conducted in August 2010, using the electronic databases PubMed, Scopus, ScienceDirect, ProQuest, and Web of Science. The search was limited to peer-reviewed journal articles published in English from January 1980 through July 2010. Data synthesis: Fourteen studies fulfilled the inclusion criteria. Most projections showed that climate change would result in a substantial increase in heat-related mortality. Projecting heat-related mortality requires understanding historical temperature–mortality relationships and considering the future changes in climate, population, and acclimatization. Further research is needed to provide a stronger theoretical framework for projections, including a better understanding of socioeconomic development, adaptation strategies, land-use patterns, air pollution, and mortality displacement. Conclusions: Scenario-based projection research will meaningfully contribute to assessing and managing the potential impacts of climate change on heat-related mortality. PMID:21816703

  6. Possible Impact of climate change on future extreme precipitation of the Oldman, Bow and Red Deer River Basins of Alberta

    NASA Astrophysics Data System (ADS)

    Yew Gan, Thian; Gizaw, Mesgana

    2016-04-01

    The impact of climate change on extreme precipitation events in the Oldman (ORB), Bow, (BRB) and Red Deer (RRB) River Basins of southern Alberta, Canada, was assessed using six extreme climate indices for the rainy period of May-August (MJJA), and 9-km resolution Special Report on Emission Scenarios (SRES) A2 and A1B climate scenarios of four Coupled Model Intercomparison Project Phase 3 (CMIP3) Global Climate Models (GCMs) dynamically downscaled by a regional climate model, MM5. R95p of the three study sites showed an increase of 4% for the 2050s (2041-2070) and 10% for the 2080s (2071-2100) period, whereas R99p increased by 39% (2050s) and 42% (2080s) which suggest a projected increase in the volume of precipitation expected in future very wet and particularly extremely wet days. Similarly, R20mm, P30yr, RX1day and RX5day are also projected to increase by about 15% by the mid- and late 21st century in the three study sites. However, compared to BRB and RRB, ORB located in the southernmost part of the study site is projected to undergo a relatively higher increase in both temperature and precipitation intensity, which is assessed in terms of indices such as P30yr, RX1day and RX5day. On the other hand, RRB and BRB are projected to experience higher increase in R20mm, which suggest a relatively higher increase in the number of very heavy precipitation days projected for these two basins. Overall, these results suggest that in the 2050s and 2080s, southern Alberta will be expected to experience more frequent and severe intensive storm events in the MJJA season that could potentially increase the risk of future flooding in this region. Ref: Gizaw, M., and Gan, T. Y., 2015, Possible Impact of climate change on future extreme precipitation of the Oldman, Bow and Red Deer River Basins of Alberta, Int. Journal Climatology, DOI:10.1002/joc.4338

  7. Assessing Future Changes in Extreme Precipitation Conditions over Greece: An Investigation of their Links with Circulation Types.

    NASA Astrophysics Data System (ADS)

    Tolika, K.; Anangostopoulou, C.; Tegoulias, I.; Vafiadis, M.

    2010-09-01

    The relationship between the extreme precipitation events and the prevailing circulation types during their occurrence is analyzed in the present study, for four of the biggest cities in Greece (Athens, Thessaloniki, Patra and Heraklio). Daily precipitation data covering the time period 1958-2000 are utilized and the extreme rainfall events are defined using the 95% percentile index. A new automatic classification was applied for the computation of the daily calendar of the circulation types. The main improvements of this classification are the number of the circulation types, which are reduced now to twelve (12) and the fact that the scheme is flexible all over the Mediterranean. The 500hPa geopotential data (2.5 o x 2.5o spatial resolution) from the NCEP/NCAR were employed, covering a large spatial window over the whole European region, for the development of the daily circulation type’s calendar. From the first results of the study it was found that two cyclonic types were the prevailing ones during extreme rainfall conditions. Further more grid point daily precipitation data (the ones closer to the four stations) derived from the most updated regional climate models were also applied in the study for a reference period 1961-1990. The simulated extreme precipitation events were evaluated in comparison to the observational data and a new circulation type calendar was computed this time using the RCMs 500hPa data. Overall, changes both in the magnitude and in the frequency of occurrence of the extreme events were detected. The final goal of the study was to asses the future changes of rainfall extremes as well as the changes of their links with the circulation types as a consequence of the enhanced greenhouse gas concentrations until the end of the 21st century. The aforementioned methodology was applied using the RCM output, both daily precipitation and geopotentials at 500hPa level, (forced by the emission scenario A1B), for the last thirty years of the

  8. High Resolution Simulation of a Colorado Rockies Extreme Snow and Rain Event in both a Current and Future Climate

    NASA Astrophysics Data System (ADS)

    Rasmussen, Roy; Ikeda, Kyoko; Liu, Changhai; Gutmann, Ethan; Gochis, David

    2016-04-01

    Modeling of extreme weather events often require very finely resolved treatment of atmospheric circulation structures in order to produce and localize the large moisture fluxes that result in extreme precipitation. This is particularly true for cool season orographic precipitation processes where the representation of the landform can significantly impact vertical velocity profiles and cloud moisture entrainment rates. This study presents results for high resolution regional climate modeling study of the Colorado Headwaters region using an updated version of the Weather Research and Forecasting (WRF) model run at 4 km horizontal resolution and a hydrological extension package called WRF-Hydro. Previous work has shown that the WRF modeling system can produce credible depictions of winter orographic precipitation over the Colorado Rockies if run at horizontal resolutions < 6 km. Here we present results from a detailed study of an extreme springtime snowfall event that occurred along the Colorado Front Range in March 2003. Results from the impact of warming on total precipitation, snow-rain partitioning and surface hydrological fluxes (evapotranspiration and runoff) will be discussed in the context of how potential changes in temperature impact the amount of precipitation, the phase of precipitation (rain vs. snow) and the timing and amplitude of streamflow responses. The results show using the Pseudo Global Warming technique that intense precipitation rates significantly increased during the event and a significant fraction of the snowfall converts to rain which significantly amplifies the runoff response from one where runoff is produced gradually to one in which runoff is rapidly translated into streamflow values that approach significant flooding risks. Results from a new, CONUS scale high resolution climate simulation of extreme events in a current and future climate will be presented as time permits.

  9. Performance and heat transfer characteristics of the laser-heated rocket - A future space transportation system

    NASA Technical Reports Server (NTRS)

    Shoji, J. M.; Larson, V. R.

    1976-01-01

    The application of advanced liquid-bipropellant rocket engine analysis techniques has been utilized for prediction of the potential delivered performance and the design of thruster wall cooling schemes for laser-heated rocket thrusters. Delivered specific impulse values greater than 1000 lbf-sec/lbm are potentially achievable based on calculations for thrusters designed for 10-kW and 5000-kW laser beam power levels. A thruster wall-cooling technique utilizing a combination of regenerative cooling and a carbon-seeded hydrogen boundary layer is presented. The flowing carbon-seeded hydrogen boundary layer provides radiation absorption of the heat radiated from the high-temperature plasma. Also described is a forced convection thruster wall cooling design for an experimental test thruster.

  10. The future of ELTs (extremely large telescopes): a very personal view

    NASA Astrophysics Data System (ADS)

    Mountain, C. Matt

    2004-07-01

    "The Future of ELTs" is an intriguing as well as daunting title. But this is not about telescopes. After all, what could top visions of telescopes ranging from a "mere" 20 meters, to 100 meters, to plastic 30-meter telescopes in space, to new telescopes for the Moon and even a "hyper-telescope" designed to fill the volcanic crater on La Palma? Instead, this is about an equally interesting subject: Advanced Telescope Builders of the Early 21st Century, which reflects on the gathering of unique individuals that Arne Ardeberg and the University of Lund have so graciously brought together at this workshop.

  11. Impacts of The Future Changes in Extreme Events on Migration in The Middle East

    NASA Astrophysics Data System (ADS)

    An, Nazan; Turp, M. Tufan; Ozturk, Tugba; Kurnaz, M. Levent

    2016-04-01

    Natural hazards are defined as extreme events that threat people, their homes and their neighborhoods. They damage housing, food production system and other infrastructures. The frequency of natural hazards namely drought, floods can influence the residential decision-making and can cause substantial residential mobility by affecting relatively greater numbers of people in the region. Developing countries are more vulnerable to the impacts of natural hazards. Therefore, environmental migration can be associated with natural hazards especially in the developing countries. Limited water resources and demographic dynamics of the Middle East make the region one of the most affected domains from the impacts of natural hazards. In this study, we consider the relationship between migration as a demographic process and the frequency of natural hazards in the Middle East for the period of 2020 - 2045 with respect to 1980 - 2005 by performing the projection according to the scenario of IPCC, namely RCP8.5 through the RegCM4.4 and combining them with an econometric analysis. This research has been supported by Boǧaziçi University Research Fund Grant Number 10421.

  12. Extremely low-frequency magnetic fields can impair spermatogenesis recovery after reversible testicular damage induced by heat.

    PubMed

    Tenorio, Bruno Mendes; Ferreira Filho, Moisés Bonifacio Alves; Jimenez, George Chaves; de Morais, Rosana Nogueira; Peixoto, Christina Alves; Nogueira, Romildo de Albuquerque; da Silva Junior, Valdemiro Amaro

    2014-06-01

    Male infertility is often related to reproductive age couples experiencing fertility-related issues. Men may have fertility problems associated with reversible testicular damage. Considering that men have been increasingly exposed to extremely low-frequency magnetic fields generated by the production, distribution and use of electricity, this study analyzed whether 60 Hz and 1 mT magnetic field exposure may impair spermatogenesis recovery after reversible testicular damage induced by heat shock using rats as an experimental model. Adult male rats were subjected to a single testicular heat shock (HS, 43 °C for 12 min) and then exposed to the magnetic field for 15, 30 and 60 d after HS. Magnetic field exposure during the spermatogenesis recovery induced changes in testis components volume, cell ultrastructure and histomorphometrical parameters. Control animals had a reestablished and active spermatogenesis at 60 d after heat shock, while animals exposed to magnetic field still showed extensive testicular degeneration. Magnetic field exposure did not change the plasma testosterone. In conclusion, extremely low-frequency magnetic field may be harmful to fertility recovery in males affected by reversible testicular damage. PMID:23781997

  13. Historical Review of Electric Household Appliances using Induction-Heating and Future Challenging Trends

    NASA Astrophysics Data System (ADS)

    Hirota, Izuo; Yamashita, Hidekazu; Omori, Hideki; Nakaoka, Mutsuo

    This paper presents historical progress on technology evolution of the electric and electronic household appliances using the inverter, especially for Induction-Heating applications, which have been put in practical use as the desk-top cooker for the first time at home in 1974 until being applied to the rice cooker and the multi-burner cooking heater. It also describes the future innovative evolution of the power semiconductor switching devices and the inverter circuit topologies supporting its progressive developments. Looking back its progress, the future trends on consumer power electronics is discussed on the practical problem in the future.

  14. Measurements of electron and proton heating temperatures from extreme-ultraviolet light images at 68 eV in petawatt laser experiments

    SciTech Connect

    Gu Peimin; Zhang, B.; Key, M. H.; Hatchett, S. P.; Barbee, T.; Freeman, R. R.; Akli, K.; Hey, D.; King, J. A.; Mackinnon, A. J.; Snavely, R. A.; Stephens, R. B.

    2006-11-15

    A 68 eV extreme-ultraviolet light imaging diagnostic measures short pulse isochoric heating by electrons and protons in petawatt laser experiments. Temperatures are deduced from the absolute intensities and comparison with modeling using a radiation hydrodynamics code.

  15. Analysis of Extreme Heat in Historical and Projected Climate Simulations for Regional Climate Planning Purposes in the U.S.

    NASA Astrophysics Data System (ADS)

    Geil, K.; Zeng, X.; McMahan, B.; Ferguson, D. B.

    2015-12-01

    The U.S. National Climate Assessment (NCA) states that global climate models predict more extreme temperatures and more frequent, intense, and longer heat waves on a regional basis as global temperatures rise throughout the 21st century, but a thorough test of whether these models can simulate observed heat metrics and trends over the historical period was not included in the assessment. Understanding the capabilities of climate models over the historical period is crucial to assessing our confidence in their predictive ability at regional scales. Our work fills this research gap by evaluating the performance of Coupled Model Intercomparison Phase 5 (CMIP5) models as compared to observational data using multiple heat metrics. Our metrics are targeted for the southwest United States, but our regional analysis covers the entire continental U.S. and Alaska using 7 of the regions delineated by the NCA. The heat metrics include heat wave and cold wave frequency, intensity, and duration, overnight low temperatures, onset and length of the hot season, and human heat stress. For the best performing models, we compute the same heat metrics for the RCP scenarios. In addition to presenting the results of our CMIP5 historical and RCP analyses, we also describe how our results may be applied to the benefit of our community in Southern Arizona as a case study. Our research will be used by NOAA's Climate Assessment for the Southwest (CLIMAS) and by an interdisciplinary collaborative team of researchers from the University of Arizona working with an electric utility to integrate climate information into their strategic planning.

  16. Excessive occupational heat exposure: a significant ergonomic challenge and health risk for current and future workers

    PubMed Central

    2014-01-01

    Occupational heat exposure threatens the health of a worker not only when heat illness occurs but also when a worker’s performance and work capacity is impaired. Occupational contexts that involve hot and humid climatic conditions, heavy physical workloads and/or protective clothing create a strenuous and potentially dangerous thermal load for a worker. There are recognized heat prevention strategies and international thermal ergonomic standards to protect the worker. However, such standards have been developed largely in temperate western settings, and their validity and relevance is questionable for some geographical, cultural and socioeconomic contexts where the risk of excessive heat exposure can be high. There is evidence from low- and middle-income tropical countries that excessive heat exposure remains a significant issue for occupational health. Workers in these countries are likely to be at high risk of excessive heat exposure as they are densely populated, have large informal work sectors and are expected to experience substantial increases in temperature due to global climate change. The aim of this paper is to discuss current and future ergonomic risks associated with working in the heat as well as potential methods for maintaining the health and productivity of workers, particularly those most vulnerable to excessive heat exposure. PMID:25057350

  17. Excessive occupational heat exposure: a significant ergonomic challenge and health risk for current and future workers.

    PubMed

    Lucas, Rebekah A I; Epstein, Yoram; Kjellstrom, Tord

    2014-01-01

    Occupational heat exposure threatens the health of a worker not only when heat illness occurs but also when a worker's performance and work capacity is impaired. Occupational contexts that involve hot and humid climatic conditions, heavy physical workloads and/or protective clothing create a strenuous and potentially dangerous thermal load for a worker. There are recognized heat prevention strategies and international thermal ergonomic standards to protect the worker. However, such standards have been developed largely in temperate western settings, and their validity and relevance is questionable for some geographical, cultural and socioeconomic contexts where the risk of excessive heat exposure can be high. There is evidence from low- and middle-income tropical countries that excessive heat exposure remains a significant issue for occupational health. Workers in these countries are likely to be at high risk of excessive heat exposure as they are densely populated, have large informal work sectors and are expected to experience substantial increases in temperature due to global climate change. The aim of this paper is to discuss current and future ergonomic risks associated with working in the heat as well as potential methods for maintaining the health and productivity of workers, particularly those most vulnerable to excessive heat exposure. PMID:25057350

  18. Questioning the Relevance of Model-Based Probability Statements on Extreme Weather and Future Climate

    NASA Astrophysics Data System (ADS)

    Smith, L. A.

    2007-12-01

    We question the relevance of climate-model based Bayesian (or other) probability statements for decision support and impact assessment on spatial scales less than continental and temporal averages less than seasonal. Scientific assessment of higher resolution space and time scale information is urgently needed, given the commercial availability of "products" at high spatiotemporal resolution, their provision by nationally funded agencies for use both in industry decision making and governmental policy support, and their presentation to the public as matters of fact. Specifically we seek to establish necessary conditions for probability forecasts (projections conditioned on a model structure and a forcing scenario) to be taken seriously as reflecting the probability of future real-world events. We illustrate how risk management can profitably employ imperfect models of complicated chaotic systems, following NASA's study of near-Earth PHOs (Potentially Hazardous Objects). Our climate models will never be perfect, nevertheless the space and time scales on which they provide decision- support relevant information is expected to improve with the models themselves. Our aim is to establish a set of baselines of internal consistency; these are merely necessary conditions (not sufficient conditions) that physics based state-of-the-art models are expected to pass if their output is to be judged decision support relevant. Probabilistic Similarity is proposed as one goal which can be obtained even when our models are not empirically adequate. In short, probabilistic similarity requires that, given inputs similar to today's empirical observations and observational uncertainties, we expect future models to produce similar forecast distributions. Expert opinion on the space and time scales on which we might reasonably expect probabilistic similarity may prove of much greater utility than expert elicitation of uncertainty in parameter values in a model that is not empirically

  19. Heat flow and temperature-depth curves throughout Alaska: finding regions for future geothermal exploration

    NASA Astrophysics Data System (ADS)

    Batir, Joseph F.; Blackwell, David D.; Richards, Maria C.

    2016-06-01

    The objective of this research is to contribute to the understanding of the thermal regime of Alaska and its relationship to geology, regional tectonics, and to suggest potential sites for future geothermal energy production. New heat flow data were collected and are combined with existing published and unpublished data, although large sections of Alaska still lack data. Fault traces were implemented into the heat flow contouring as an additional gridding constraint, to incorporate both heat flow measurements and geology. New heat flow data supported the use of geologic trends in the heat flow mapping procedure, and a heat flow map of Alaska was produced with this added constraint. The multi-input contouring strategy allows production of a map with a regional interpretation of heat flow, in addition to site-specific heat flow and thermal model interpretations in areas with sufficient data density. Utilizing the new heat flow map, temperature-at-depth curves were created for example areas. Temperature-at-depth curves are calculated to 10 km depth for the areas of Anchorage, Fairbanks, Juneau, the Alaska Peninsula, Bristol Bay, and the Copper River Basin. The temperatures-at-depth predicted near the population centers of Anchorage and Juneau are relatively low, limiting the geothermal resource potential. The Fairbanks area temperature estimates are near conventional power production temperatures (150 °C) between 3.5 and 4 km. All data areas, except at Juneau, have temperatures sufficient for low temperature geothermal applications (40 °C) by 2 km. A high heat flow region exists within the Aleutian Volcanic Arc, although new data show heat flow variations from 59 to 120 mW m‑2, so individual geothermal resources within the arc will be irregularly located.

  20. Response of extreme flood characteristics based on future climate change scenarios at Yermasoyia watershed, Cyprus

    NASA Astrophysics Data System (ADS)

    Vasiliades, Lampros; Gkilimanakis, Eleftherios; Loukas, Athanasios

    2014-05-01

    The aim of this study which was performed within working group 4 in the FloodFreq COST Action is to assess and quantify changes in daily streamflow and subsequent flood response modelling due to potential climate change in Yermasoyia watershed, Cyprus. Eight statistical downscaling methods are used to estimate historical and future daily precipitation and temperature timeseries. Four methods are based on change factors and four are bias correction methods and these methods are used to downscale precipitation and temperature output from fifteen RCMs from the ENSEMBLES project. Several well-known lumped hydrological model structures (such as the GR4J, the IHACRES models, and the AWBM) are applied to estimate the daily streamflows. Performance of the models is evaluated with the use of fit statistics or metrics for calibration and validation periods using the split sample test. A set of flood indices are derived from the daily simulated streamflows and their changes have been evaluated by comparing the periods 1960-1990 and 2070-2100. The results show that both the magnitude and the volume of annual peakflows is decreasing fow all examined scenarios, downscaling methods and employed hydrological models.

  1. Flood risk under future climate in data sparse regions: Linking extreme value models and flood generating processes

    NASA Astrophysics Data System (ADS)

    Tramblay, Yves; Amoussou, Ernest; Dorigo, Wouter; Mahé, Gil

    2014-11-01

    For many areas in the world, there is a need for future projections of flood risk in order to improve the possible mitigation actions. However, such an exercise is often made difficult in data-sparse regions, where the limited access to hydrometric data does not allow calibrating hydrological models in a robust way under non-stationary conditions. In this study we present an approach to estimate possible changes in flood risks, which incorporates flood generating processes into statistical models for extreme values. This approach is illustrated for a West African catchment, the Mono River (12,900 km2), with discharge, precipitation and temperature data available between 1988 and 2010 and where the dominant flood generating process is soil saturation. A soil moisture accounting (SMA) model, calibrated against a merged surface soil moisture microwave satellite dataset, is used to estimate the annual maximum soil saturation level that is related to the location parameter of a generalized extreme value model of annual maximum discharge. With such a model, it is possible to estimate the changes in flood quantiles from the changes in the annual maximum soil saturation level. An ensemble of regional climate models from the ENSEMBLES-AMMA project are then considered to estimate the potential future changes in soil saturation and subsequently the changes in flood risks for the period 2028-2050. A sensitivity analysis of the non-stationary flood quantiles has shown that with the projected changes on precipitation (-2%) and temperature (+1.22°) under the scenario A1B, the projected flood quantiles would stay in the range of the observed variability during 1988-2010. The proposed approach, relying on low data requirements, could be useful to estimate the projected changes in flood risks for other data-sparse catchments where the dominant flood-generating process is soil saturation.

  2. Survival of the faucet snail after chemical disinfection, pH extremes, and heated water bath treatments

    USGS Publications Warehouse

    Mitchell, A.J.; Cole, R.A.

    2008-01-01

    The faucet snail Bithynia tentaculata, a nonindigenous aquatic snail from Eurasia, was introduced into Lake Michigan in 1871 and has spread to the mid-Atlantic states, the Great Lakes region, Montana, and most recently, the Mississippi River. The faucet snail serves as intermediate host for several trematodes that have caused large-scale mortality among water birds, primarily in the Great Lakes region and Montana. It is important to limit the spread of the faucet snail; small fisheries equipment can serve as a method of snail distribution. Treatments with chemical disinfection, pH extremes, and heated water baths were tested to determine their effectiveness as a disinfectant for small fisheries equipment. Two treatments eliminated all test snails: (1) a 24-h exposure to Hydrothol 191 at a concentration of at least 20 mg/L and (2) a treatment with 50??C heated water for 1 min or longer. Faucet snails were highly resistant to ethanol, NaCl, formalin, Lysol, potassium permanganate, copper sulfate, Baquacil, Virkon, household bleach, and pH extremes (as low as 1 and as high as 13).

  3. Frequency of Extreme Heat Event as a Surrogate Exposure Metric for Examining the Human Health Effects of Climate Change

    PubMed Central

    Romeo Upperman, Crystal; Parker, Jennifer; Jiang, Chengsheng; He, Xin; Murtugudde, Raghuram; Sapkota, Amir

    2015-01-01

    Epidemiological investigation of the impact of climate change on human health, particularly chronic diseases, is hindered by the lack of exposure metrics that can be used as a marker of climate change that are compatible with health data. Here, we present a surrogate exposure metric created using a 30-year baseline (1960–1989) that allows users to quantify long-term changes in exposure to frequency of extreme heat events with near unabridged spatial coverage in a scale that is compatible with national/state health outcome data. We evaluate the exposure metric by decade, seasonality, area of the country, and its ability to capture long-term changes in weather (climate), including natural climate modes. Our findings show that this generic exposure metric is potentially useful to monitor trends in the frequency of extreme heat events across varying regions because it captures long-term changes; is sensitive to the natural climate modes (ENSO events); responds well to spatial variability, and; is amenable to spatial/temporal aggregation, making it useful for epidemiological studies. PMID:26641244

  4. The biophysical and physiological basis for mitigated elevations in heart rate with electric fan use in extreme heat and humidity

    NASA Astrophysics Data System (ADS)

    Ravanelli, Nicholas M.; Gagnon, Daniel; Hodder, Simon G.; Havenith, George; Jay, Ollie

    2016-07-01

    Electric fan use in extreme heat wave conditions has been thought to be disadvantageous because it might accelerate heat gain to the body via convection. However, it has been recently shown that fan use delays increases in heart rate even at high temperatures (42 °C) in young adults. We here assess the biophysical and physiological mechanisms underlying the apparently beneficial effects of fan use. Eight males (24 ± 3 y; 80.7 ± 11.7 kg; 2.0 ± 0.1 m2) rested at either 36 °C or 42 °C, with (F) or without (NF) electric fan use (4.2 m/s) for 120 min while humidity increased every 7.5 min by 0.3 kPa from a baseline value of 1.6 kPa. Heart rate (HR), local sweat rate (LSR), cutaneous vascular conductance (CVC), core and mean skin temperatures, and the combined convective/radiative heat loss (C+R), evaporative heat balance requirements (Ereq) and maximum evaporative potential (Emax) were assessed. C+R was greater with fan use at 36 °C (F 8 ± 6, NF 2 ± 2 W/m2; P = 0.04) and more negative (greater dry heat gain) with fan use at 42 °C (F -78 ± 4, NF -27 ± 2 W/m2; P < 0.01). Consequently, Ereq was lower at 36 °C (F 38 ± 16, NF 45 ± 3 W/m2; P = 0.04) and greater at 42 °C (F 125 ± 1, NF 74 ± 3 W/m2; P < 0.01) with fan use. However, fan use resulted in a greater Emax at baseline humidity at both 36 °C (F 343 ± 10, NF 153 ± 5 W/m2; P < 0.01) and 42 °C (F 376 ± 13, NF 161 ± 4 W/m2; P < 0.01) and throughout the incremental increases in humidity. Within the humidity range that a rise in HR was prevented by fan use but not without a fan, LSR was higher in NF at both 36 °C (P = 0.04) and 42 °C (P = 0.05), and skin temperature was higher in NF at 42 °C (P = 0.05), but no differences in CVC or core temperatures were observed (all P > 0.05). These results suggest that the delayed increase in heart rate with fan use during extreme heat and humidity is associated with improved evaporative efficiency.

  5. How well can change diagnose the effects of coupling of the Regional Atmosphere on ET of an Irrigated Surface Under Extreme Advection of Heat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The role of imported heat and saturation deficit versus available energy on the energy balance of a cotton field is investigated in a semi-arid region under a range of conditions, including extreme horizontal advection of heat. Using eddy covariance measurements of water vapor fluxes, a modified Pen...

  6. Combining regional climate and national human development scenarios to estimate future vulnerability to extreme climate and weather events

    NASA Astrophysics Data System (ADS)

    Patt, A.; Nussbaumer, P.

    2009-04-01

    Extreme climate and weather events such as droughts, floods, and tropical cyclones account for over 60% of the loss of life, and over 90% of total impacts, from natural disasters. Both observed trends and global climate models (GCMs) suggest that the frequency and intensity of extreme events is increasing, and will continue to increase as a result of climate change. Among planners and policy-makers at both national and international levels there is thus concern that this rise in extreme events will lead to greater losses in the future. Since low levels of development are associated with greater numbers of people killed and needing emergency assistance from natural disasters, the concern is most pronounced for least developed countries. If, however, these countries make substantial improvements in their levels of human development, as leading forecasters suggest may be the case over the coming decades, then their vulnerability to extreme events may fall. In this study, we examine the potential combined effects of increased extreme event frequency and improved levels of human development, to generate scenarios of risk levels into the second half of the century. It is the African continent for which these results may be the most relevant, since it is widely viewed as most vulnerable to increased risks from climate change; we focus on the particular country of Mozambique, which has experienced high losses from droughts, floods, and tropical cyclones in recent decades, and stands out as being among the most vulnerable in Africa. To assess the change in risk levels from the present until 2060, we pull together three pieces of analysis. The first is a statistical analysis of the losses from 1990-2007 from climate-related disasters, using national level data from the Centre for Research on the Epidemiology of Disasters (CRED) and the United Nations. From this analysis, we establish statistical relationships between several drivers of vulnerability—including country size

  7. The Escherichia coli small heat-shock proteins IbpA and IbpB prevent the aggregation of endogenous proteins denatured in vivo during extreme heat shock.

    PubMed

    Kuczyńska-Wiśnik, Dorota; Kedzierska, Sabina; Matuszewska, Ewelina; Lund, Peter; Taylor, Alina; Lipińska, Barbara; Laskowska, Ewa

    2002-06-01

    The roles of the Escherichia coli IbpA and IbpB chaperones in protection of heat-denatured proteins against irreversible aggregation in vivo were investigated. Overproduction of IbpA and IbpB resulted in stabilization of the denatured and reversibly aggregated proteins (the S fraction), which could be isolated from E. coli cells by sucrose gradient centrifugation. This finding is in agreement with the present model of the small heat-shock proteins' function, based mainly on in vitro studies. Deletion of the ibpAB operon resulted in almost twofold increase in protein aggregation and in inactivation of an enzyme (fructose-1,6-biphosphate aldolase) in cells incubated at 50 degrees C for 4 h, decreased efficiency of the removal of protein aggregates formed during prolonged incubation at 50 degrees C and affected cell viability at this temperature. IbpA/B proteins were not needed for removal of protein aggregates or for the enzyme protection/renaturation in cells heat shocked at 50 degrees C for 15 min. These results show that the IbpA/B proteins are required upon an extreme, long-term heat shock. Overproduction of IbpA but not IbpB caused an increase of the level of beta-lactamase precursor, which was localized in the S fraction, together with the IbpA protein, which suggests that the unfolded precursor binds to IbpA but not to IbpB. Although in the wild-type cells both E. coli small heat-shock proteins are known to localize in the S fraction, only 2% of total IbpB co-localized with the aggregated proteins in the absence of IbpA, while in the absence of IbpB, the majority of IbpA was present in the aggregates fraction. PMID:12055295

  8. Extreme degree of ionization in homogenous micro-capillary plasma columns heated by ultrafast current pulses.

    PubMed

    Avaria, G; Grisham, M; Li, J; Tomasel, F G; Shlyaptsev, V N; Busquet, M; Woolston, M; Rocca, J J

    2015-03-01

    Homogeneous plasma columns with ionization levels typical of megaampere discharges are created by rapidly heating gas-filled 520-μm-diameter channels with nanosecond rise time current pulses of 40 kA. Current densities of up to 0.3  GA cm^{-2} greatly increase Joule heating with respect to conventional capillary discharge Z pinches, reaching unprecedented degrees of ionization for a high-Z plasma column heated by a current pulse of remarkably low amplitude. Dense xenon plasmas are ionized to Xe^{28+}, while xenon impurities in hydrogen discharges reach Xe^{30+}. The unique characteristics of these hot, ∼300:1 length-to-diameter aspect ratio plasmas allow the observation of unexpected spectroscopic phenomena. Axial spectra show the unusual dominance of the intercombination line over the resonance line of He-like Al by nearly an order of magnitude, caused by differences in opacities in the axial and radial directions. These plasma columns could enable the development of sub-10-nm x-ray lasers. PMID:25793819

  9. Extreme Degree of Ionization in Homogenous Micro-Capillary Plasma Columns Heated by Ultrafast Current Pulses

    NASA Astrophysics Data System (ADS)

    Avaria, G.; Grisham, M.; Li, J.; Tomasel, F. G.; Shlyaptsev, V. N.; Busquet, M.; Woolston, M.; Rocca, J. J.

    2015-03-01

    Homogeneous plasma columns with ionization levels typical of megaampere discharges are created by rapidly heating gas-filled 520 -μ m -diameter channels with nanosecond rise time current pulses of 40 kA. Current densities of up to 0.3 GA cm-2 greatly increase Joule heating with respect to conventional capillary discharge Z pinches, reaching unprecedented degrees of ionization for a high-Z plasma column heated by a current pulse of remarkably low amplitude. Dense xenon plasmas are ionized to Xe28 + , while xenon impurities in hydrogen discharges reach Xe30 + . The unique characteristics of these hot, ˜300 :1 length-to-diameter aspect ratio plasmas allow the observation of unexpected spectroscopic phenomena. Axial spectra show the unusual dominance of the intercombination line over the resonance line of He-like Al by nearly an order of magnitude, caused by differences in opacities in the axial and radial directions. These plasma columns could enable the development of sub-10-nm x-ray lasers.

  10. SISGR - In situ characterization and modeling of formation reactions under extreme heating rates in nanostructured multilayer foils

    SciTech Connect

    Hufnagel, Todd C.

    2014-06-09

    Materials subjected to extreme conditions, such as very rapid heating, behave differently than materials under more ordinary conditions. In this program we examined the effect of rapid heating on solid-state chemical reactions in metallic materials. One primary goal was to develop experimental techniques capable of observing these reactions, which can occur at heating rates in excess of one million degrees Celsius per second. One approach that we used is x-ray diffraction performed using microfocused x-ray beams and very fast x-ray detectors. A second approach is the use of a pulsed electron source for dynamic transmission electron microscopy. With these techniques we were able to observe how the heating rate affects the chemical reaction, from which we were able to discern general principles about how these reactions proceed. A second thrust of this program was to develop computational tools to help us understand and predict the reactions. From atomic-scale simulations were learned about the interdiffusion between different metals at high heating rates, and about how new crystalline phases form. A second class of computational models allow us to predict the shape of the reaction front that occurs in these materials, and to connect our understanding of interdiffusion from the atomistic simulations to measurements made in the laboratory. Both the experimental and computational techniques developed in this program are expected to be broadly applicable to a wider range of scientific problems than the intermetallic solid-state reactions studied here. For example, we have already begun using the x-ray techniques to study how materials respond to mechanical deformation at very high rates.

  11. Design of an Extreme Ultraviolet Spectrometer Suite for Isochoric-Heated Warm-Dense-Matter Studies

    NASA Astrophysics Data System (ADS)

    Ivancic, S.; Stillman, C. R.; Nilson, P. M.; Froula, D. H.

    2015-11-01

    An ultrafast streaked extreme ultraviolet (XUV) spectrometer (5 to 35 nm) is in development for the measurement of warm dense matter (WDM). In contrast to other forms of pyrometry where the temperature is inferred from bulk x-ray emission, XUV emission is restricted to the sample surface, allowing for the measurement of temperature at the material-vacuum interface. The measurement of the surface temperature is of particular importance in constraining models for the release of WDM. The divergence of surface and bulk temperature measurements may indicate gradients in temperature in the target. Coupling the XUV spectrometer to an ultrafast streak camera allows for the observation of picosecond time-scale evolution of the surface layer temperature. Two high-throughput XUV spectrometers are being designed to measure the time-resolved and absolute XUV emission. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  12. Impact of Climate Change on Heavy Precipitation Events : Application of Extreme Value Theory to a Future Climate Simulation over the Colorado Headwaters Region

    NASA Astrophysics Data System (ADS)

    Ikeda, K.; Prein, A.; Rasmussen, R.; Liu, C.; Holland, G. J.

    2012-12-01

    Heavy precipitation cause devastating warm-season floods and cool-season snow and icing hazards that impact socio-economic communities of various scales. The frequency and severity of extreme precipitation events potentially are likely to be impacted by climate change. In this study we will investigate potential change in extreme precipitation intensity in a future climate over the Colorado headwaters region based on an extreme value approach ("peak-over-threshold" approach). The data come from Weather Research and Forecasting (WRF) model simulations of current and future climate conducted by the Colorado Headwaters Project (e.g., Rasmussen et al. 2011). The simulations were performed over eight years with 4, 12, and 36 km horizontal grid spacing. In the current study, we first evaluate the model ability to properly represent extreme precipitation events from the current climate simulation. Then we present changes in extreme precipitation intensity in the future climate for different seasons and over eight mountain ranges of the Colorado headwaters region. Our analyses so far have shown that the 4-km model outperformed coarser grid resolution models in representing extreme precipitation compared to Snowpack Telemetry (SNOTEL) surface observations. Overall, the 10-year return level in the future climate increased (more intense extreme precipitation) for all mountain ranges in the cool season. There was a general decrease in the 10-year return level (less intense extreme precipitation) in the warm season. The sign and magnitude of the change shows regional differences possibly related to seasonal storm tracks and characteristics. Detailed analysis from case studies will be presented to illustrate the impacts of a warmer and moister atmosphere on the microphysical structure of storm clouds and surface precipitation distribution.

  13. Analysis of extreme climatic features over South America from CLARIS-LPB ensemble of regional climate models for future conditions

    NASA Astrophysics Data System (ADS)

    Sanchez, E.; Zaninelli, P.; Carril, A.; Menendez, C.; Dominguez, M.

    2012-04-01

    An ensemble of seven regional climate models (RCM) included in the European CLARIS-LPB project (A Europe-South America Network for Climate Change Assessment and Impact Studies in La Plata Basin) are used to study how some features related to climatic extremes are projected to be changed by the end of XXIst century. These RCMs are forced by different IPCC-AR4 global climate models (IPSL, ECHAM5 and HadCM3), covering three different 30-year periods: present (1960-1990), near future (2010-2040) and distant future (2070-2100), with 50km of horizontal resolution. These regional climate models have previously been forced with ERA-Interim reanalysis, in a consistent procedure with CORDEX (A COordinated Regional climate Downscaling EXperiment) initiative for the South-America domain. The analysis shows a good agreement among them and the available observational databases to describe the main features of the mean climate of the continent. Here we focus our analysis on some topics of interest related to extreme events, such as the development of diagnostics related to dry-spells length, the structure of the frequency distribution functions over several subregions defined by more or less homogeneous climatic conditions (four sub-basins over the La Plata Basin, the southern part of the Amazon basin, Northeast Brazil, and the South Atlantic Convergence Zone (SACZ)), the structure of the annual cycle and their main features and relation with the length of the seasons, or the frequency of anomalous hot or cold events. One shortcoming that must be considered is the lack of observational databases with both time and spatial frequency to validate model outputs. At the same time, one challenging issue of this study is the regional modelling description of a continent where a huge variety of climates are present, from desert to mountain conditions, and from tropical to subtropical regimes. Another basic objective of this preliminary work is also to obtain a measure of the spread among

  14. Historical and potential future impacts of extreme hydrological events on the Amazonian floodplain hydrology and inundation dynamics

    NASA Astrophysics Data System (ADS)

    Macedo, M.; Panday, P. K.; Coe, M. T.; Lefebvre, P.; Castello, L.

    2015-12-01

    The Amazonian floodplains and wetlands cover one fifth of the basin and are highly productive promoting diverse biological communities and sustaining human populations with fisheries. Seasonal inundation of the floodplains fluctuates in response to drought or extreme rainfall as observed in the recent droughts of 2005 and 2010 where river levels dropped to among the lowest recorded. We model and evaluate the historical (1940-2010) and projected future (2010-2100) impacts of droughts and floods on the floodplain hydrology and inundation dynamics in the central Amazon using the Integrated Biosphere Simulator (IBIS) and the Terrestrial Hydrology Model and Biogeochemistry (THMB). Simulated discharge correlates well with observed discharges for tributaries originating in Brazil but underestimates basins draining regions in the non-Brazilian Amazon (Solimões, Japuŕa, Madeira, and Negro) by greater than 30%. A volume bias-correction from the simulated and observed runoff was used to correct the input precipitation across the major tributaries of the Amazon basin that drain the Andes. Simulated hydrological parameters (discharge, inundated area and river height) using corrected precipitation has a strong correlation with field measured discharge at gauging stations, surface water extent data (Global Inundation Extent from Multi-Satellites (GIEMS) and NASA Earth System Data Records (ESDRs) for inundation), and satellite radar altimetry (TOPEX/POSEIDON altimeter data for 1992-1998 and ENVISAT data for 2002-2010). We also used an ensemble of model outputs participating in the IPCC AR5 to drive two sets of simulations with and without carbon dioxide fertilization for the 2006-2100 period, and evaluated the potential scale and variability of future changes in discharge and inundation dynamics due to the influences of climate change and vegetation response to carbon dioxide fertilization. Preliminary modeled results for future scenarios using Representative Concentration

  15. Climate change impacts on extreme events in the United States: an uncertainty analysis

    EPA Science Inventory

    Extreme weather and climate events, such as heat waves, droughts and severe precipitation events, have substantial impacts on ecosystems and the economy. However, future climate simulations display large uncertainty in mean changes. As a result, the uncertainty in future changes ...

  16. COMBINING EMPIRICAL ORTHOGONAL FUNCTION AND EXTREME VALUE THEORY METHODS TO CHARACTERIZE OBSERVED AND FUTURE CHANGES IN EXTREME U.S. AIR POLLUTION EVENTS

    EPA Science Inventory

    The occurrence of meteorological conditions associated with poor air quality (i.e. elevated levels of ozone and particulate matter) that are classified as extreme events at present are expected to increase in a warmer climate. Using state-of-the-art statistical techniques, ...

  17. Effect of cold water and inverse lighting on growth performance of broiler chickens under extreme heat stress.

    PubMed

    Park, Sang-oh; Park, Byung-sung; Hwangbo, Jong

    2015-07-01

    The present study was carried out to investigate the effect of provision of extreme heat stress diet (EHD), inverse lighting, cold water on growth performance of broiler chickens exposed to extreme heat stress. The chickens were divided into four treatment groups, (T1, T2, T3, T4) as given below: Ti (EHD 1, 10:00-19:00 dark, 19:00-10:00 light, cool water 9 degrees C); T2 (EHD 2, 10:00-19:00 dark, 19:00-10:00 light, cool water 9 degrees C); T3 (EHD 1, 09:00-18:00 dark, 18:00-09:00 light, cool water 141C); T4 (EHD 2, 09:00-18:00 dark, 18:00-09:00 light, cool water 14 degrees C. EHD 1 contained soybean oil, molasses, methionine and lysine; EHD 2 contained the same ingredients as EHD 1 with addition of vitamin C. Groups T1 and T2 were given cooler water than the othertwo groups, and displayed higher body weight increase and diet intake as compared to T3 and T4 (p<0.05). The weights of their liver and gizzard were similar but the weights of the thymus and bursa of fabricius (F) were higher in groups T1 and T2 (p<0.05). It was observed that groups T1 and T2 displayed higher concentrations of blood triglyceride, total cholesterol, HDL-cholesterol and blood sugar as compared to T3 and T4; however LDL-cholesterol level was higher in groups T3 and T4 (p<0.05). T1 and T2 displayed higher levels of immunity substances such as IgG, IgAand IgM as compared to T3 and T4, but the blood level of corticosterone was lower in groups T1 and T2 (p<0.05). Ti and T2 contained higher amount of fecal Lactobacill as compared to T3 and T4; howeverT3 and T4 contained higher amount of fecal E. coli, total aerobic bacteria and coliform bacteria (p<0.05). Groups T1 and T2 displayed higher concentrations of cecal total short chain fatty acids, acetic acid and propionic acid but groups T3 and T4 displayed higher concentrations of butyric acid, isobutyric acid, valeric acid and isovaleric acid (p<0.05). The present study reports novel results such that the supply of extreme heat stress diet, inverse

  18. Extremes of heat conduction-Pushing the boundaries of the thermal conductivity of materials

    SciTech Connect

    Cahill, DG

    2012-09-12

    Thermal conductivity is a familiar property of materials: silver conducts heat well, and plastic does not. In recent years, an interdisciplinary group of materials scientists, engineers, physicists, and chemists have succeeded in pushing back long-established limits in the thermal conductivity of materials. Carbon nanotubes and graphene are at the high end of the thermal conductivity spectrum due to their high sound velocities and relative lack of processes that scatter phonons. Unfortunately, the superlative thermal properties of carbon nanotubes have not found immediate application in composites or interface materials because of difficulties in making good thermal contact with the nanotubes. At the low end of the thermal conductivity spectrum, solids that combine order and disorder in the random stacking of two-dimensional crystalline sheets, so-called "disordered layered crystals," show a thermal conductivity that is only a factor of 2 larger than air. The cause of this low thermal conductivity may be explained by the large anisotropy in elastic constants that suppresses the density of phonon modes that propagate along the soft direction. Low-dimensional quantum magnets demonstrate that electrons and phonons are not the only significant carriers of heat. Near room temperature, the spin thermal conductivity of spin-ladders is comparable to the electronic thermal conductivities of metals. Our measurements of nanoscale thermal transport properties employ a variety of ultrafast optical pump-probe metrology tools that we have developed over the past several years. We are currently working to extend these techniques to high pressures (60 GPa), high magnetic fields (5 T), and high temperatures (1000 K).

  19. ICRF heating in Alcator C-Mod: Present status and future prospects

    SciTech Connect

    Porkolab, M.; Fiore, C.; Greenwald, M.; Hosea, J. C.; Hubbard, A.; Hutchinson, I.; Irby, J.; Nelson-Melby, E.; Marmar, E.; Phillips, C. K.

    1999-09-20

    Alcator C-Mod, the high field, high density, diverted, compact tokamak in the world's portfolio of high performance plasma fusion devices, is heated exclusively with ICRF auxiliary power. In this paper an overview of recent results is summarized, with particular attention given to the importance of RF operation and the flexibility afforded by different heating scenarios. Besides the routine minority heating operation, results in the mode conversion heating regime are also presented (mainly direct electron heating through mode converted ion Bernstein waves). Recent attempts at improving plasma performance by establishing internal transport barriers (ITBs) by various transient profile control techniques (the so-called Advanced Tokamak mode of operation) are also presented. Future improvements in performance afforded by the recent addition of a new 4-strap antenna and 4 MW of tunable (40-80 MHz) ICRF power are also discussed. Mode-conversion current drive (MCCD) and fast wave current drive (FWCD) will be among the many new options that will be tested with the goal of improving plasma performance. (c) 1999 American Institute of Physics.

  20. Understanding the 2013 Boulder Flood: Assessing Extreme Precipitation Events and Future Climates in the Community Earth System Model (CESM)

    NASA Astrophysics Data System (ADS)

    Adams, R.; Neale, R. B.

    2014-12-01

    The Boulder flood of September 2013 resulted in significant structural damage, inundated communities, and accelerated land erosion in central and northern Colorado. This exceptional event led to approximately 11,000 people being evacuated in the area as more than 17 inches of rain fell in parts of Boulder County, Colorado in seven days. This storm resulted from persistent southerly flow and high precipitable water values which were responsible for the record-breaking precipitation. This study assessed the factors associated with extreme precipitation events in both observations and climate model simulations. Satellite-based observed precipitation from the Tropical Rainfall Measuring Mission, and ERA-Interim Reanalysis of precipitable water and low-level winds were used in this study. Probability distribution functions (PDFs) were calculated for daily values of observational and reanalysis variables: precipitation, precipitable water, and low-level winds. Each of the PDFs were compared with equivalent variables in the CESM simulations and analyzed over three regions of different areal extent occupying the eastern Rocky Mountains. The PDF calculations were found to be sensitive to the choice of the spatial region with fewer high precipitable water events in the northern domain and a greater number of high precipitable water events in the more southerly domain. The similarities between observational and present-day CESM PDFs enabled us to study changes to PDF distributions in future climate simulations. They predict a significant increase in precipitable water over the Boulder flood region. Given the importance of high precipitable water in the 2013 Boulder flood precipitation event, the potential for more frequent and stronger flooding events in the future is significant.

  1. Heat wave beats green wave: the effect of a climate extreme on alpine grassland phenology as seen by phenocams

    NASA Astrophysics Data System (ADS)

    Cremonese, Edoardo; Filippa, Gianluca; Migliavacca, Mirco; Siniscalco, Consolata; Oddi, Ludovica; Galvagno, Marta

    2016-04-01

    The year 2015 has been one of the warmest on record for many regions of the world. The record-breaking temperatures did not spare the European Alps, where the summer anomaly reached +4°C. This heat wave caused important impacts on the seasonal development and structural properties of alpine grasslands that deserve investigations. Phenocams are useful tools to describe canopy greenness seasonal dynamics and many recent studies demonstrated that the major phenological events (e.g. budbrust, senescence, …) can be extracted from greenness trajectories. In contrast, little is know about their capabilities to describe the impact of extreme climate events on a fully developed canopy. Moreover the relation between quantitative structural and functional vegetation properties (e.g. biomass, LAI, …) and phenocam data remains poorly investigated. In this study we examine the impact of the 2015 summer heat wave on a subalpine grassland by jointly analyzing phenocam greenness trajectories, proximal sensing and flux data together with field measures of vegetation structural properties. The effect of different environmental drivers on greenness seasonal development was further evaluated by a modeling approach (GSI model). Phenocam tracked the impact of heatwave 2015 that caused a lower canopy development and an anticipation of yellowing by more than 2 months. The same pattern was observed for CO2 fluxes, NDVI and field measures. GSI model results show that during the heatwave, a combination of moisture and high temperature limitation was responsible for the observed reduction of the canopy development. Moreover, spatially explicit analysis of digital images allowed to highlight the differential response of specific plant functional types to the extreme event.

  2. The contribution of urbanization to recent extreme heat events and a potential mitigation strategy in the Beijing-Tianjin-Hebei metropolitan area

    NASA Astrophysics Data System (ADS)

    Wang, Mingna; Yan, Xiaodong; Liu, Jiyuan; Zhang, Xuezhen

    2013-11-01

    This paper addresses the contribution of urban land use change to near-surface air temperature during the summer extreme heat events of the early twenty-first century in the Beijing-Tianjin-Hebei metropolitan area. This study uses the Weather Research Forecasting model with a single urban canopy model and the newest actual urban cover datasets. The results show that urban land use characteristics that have evolved over the past ~20 years in the Beijing-Tianjin-Hebei metropolitan area have had a significant impact on the extreme temperatures occurring during extreme heat events. Simulations show that new urban development has caused an intensification and expansion of the areas experiencing extreme heat waves with an average increase in temperature of approximately 0.60 °C. This change is most obvious at night with an increase up to 0.95 °C, for which the total contribution of anthropogenic heat is 34 %. We also simulate the effects of geo-engineering strategies increasing the albedo of urban roofs, an effective way of reducing urban heat island, which can reduce the urban mean temperature by approximately 0.51 °C and counter approximately 80 % of the heat wave results from urban sprawl during the last 20 years.

  3. Extreme ultra-violet burst, particle heating, and whistler wave emission in fast magnetic reconnection induced by kink-driven Rayleigh-Taylor instability

    NASA Astrophysics Data System (ADS)

    Chai, Kil-Byoung; Zhai, Xiang; Bellan, Paul M.

    2016-03-01

    A spatially localized energetic extreme ultra-violet (EUV) burst is imaged at the presumed position of fast magnetic reconnection in a plasma jet produced by a coaxial helicity injection source; this EUV burst indicates strong localized electron heating. A circularly polarized high frequency magnetic field perturbation is simultaneously observed at some distance from the reconnection region indicating that the reconnection emits whistler waves and that Hall dynamics likely governs the reconnection. Spectroscopic measurement shows simultaneous fast ion heating. The electron heating is consistent with Ohmic dissipation, while the ion heating is consistent with ion trajectories becoming stochastic.

  4. Thermal Modeling and Analysis of a Cryogenic Tank Design Exposed to Extreme Heating Profiles

    NASA Technical Reports Server (NTRS)

    Stephens, Craig A.; Hanna, Gregory J.

    1991-01-01

    A cryogenic test article, the Generic Research Cryogenic Tank, was designed to qualitatively simulate the thermal response of transatmospheric vehicle fuel tanks exposed to the environment of hypersonic flight. One-dimensional and two-dimensional finite-difference thermal models were developed to simulate the thermal response and assist in the design of the Generic Research Cryogenic Tank. The one-dimensional thermal analysis determined the required insulation thickness to meet the thermal design criteria and located the purge jacket to eliminate the liquefaction of air. The two-dimensional thermal analysis predicted the temperature gradients developed within the pressure-vessel wall, estimated the cryogen boiloff, and showed the effects the ullage condition has on pressure-vessel temperatures. The degree of ullage mixing, location of the applied high-temperature profile, and the purge gas influence on insulation thermal conductivity had significant effects on the thermal behavior of the Generic Research Cryogenic Tank. In addition to analysis results, a description of the Generic Research Cryogenic Tank and the role it will play in future thermal structures and transatmospheric vehicle research at the NASA Dryden Flight Research Facility is presented.

  5. The role of water vapor and its associated latent heating in extreme Beaufort coastal storm surge events

    NASA Astrophysics Data System (ADS)

    Gyakum, J. R.; Small, D. L.; Atallah, E.; Liu, N.; Kuo, Y.

    2009-12-01

    During the rather limited ice-free season that typically may occur from late July through early October, the Beaufort Sea region is susceptible to extreme windstorms, many of which produce damaging storm surges to low-lying coastal communities. During the most recent years, the ice-free season has lengthened, suggesting an increased vulnerability of coastal communities to cyclogenesis-related windstorms. Therefore, our research focuses on the dynamic and thermodynamic mechanisms responsible for significant surface wind events during the ice-free season in this region. We demonstrate that these storm surge events are often associated with the generation of large-scale atmospheric circulation regomes conducive to North American droughts. Our analysis methodology includes the detailed synoptic-dynamic analysis, including numerical experiments, on a case of an especially long-lived extreme storm surge that occurred in September 1999. We utilize conventional surface and upper-air station data, along with satellite and ground-based water vapor data. We also utilize global and regional reanalysis data to document the synoptic-scale and mesoscale environments associated with the cyclogenesis events. Our numerical experiments with the Weather Research and Forecasting (WRF) model include sensitivity testing with COSMIC-derived water vapor data, and sensitivity tests to illustrate the relative roles that latent heating plays in the storm surge event, at various stages in its lifecycle. A particularly important finding of our research on the devastating September 1999 storm surge event is that a relatively rare case of explosive cyclogenesis in the Gulf of Alaska is a key player in this Beaufort storm surge. The deep-tropospheric latent heating during the explosive cyclogenesis generates a dynamic tropopause ridge. This ridge in turn induces surface ridging that contributes to the strong west-northwesterlies associated with the storm surge. This generation of the dynamic

  6. Extremes of heat, drought and precipitation depress reproductive performance in shortgrass prairie passerines

    USGS Publications Warehouse

    Conrey, Reesa Y.; Skagen, Susan; Yackel, Amy; Panjabi, Arvind O.

    2016-01-01

    Climate change elevates conservation concerns worldwide because it is likely to exacerbate many identified threats to animal populations. In recent decades, grassland birds have declined faster than other North American bird species, a loss thought to be due to habitat loss and fragmentation and changing agricultural practices. Climate change poses additional threats of unknown magnitude to these already declining populations. We examined how seasonal and daily weather conditions over 10 years influenced nest survival of five species of insectivorous passerines native to the shortgrass prairie and evaluate our findings relative to future climate predictions for this region. Daily nest survival (n = 870) was best predicted by a combination of daily and seasonal weather variables, age of nest, time in season and bird habitat guild. Within a season, survival rates were lower on very hot days (temperatures ≥ 35 °C), on dry days (with a lag of 1 day) and on stormy days (especially for those species nesting in shorter vegetation). Across years, survival rates were also lower during warmer and drier breeding seasons. Clutch sizes were larger when early spring temperatures were cool and the week prior to egg-laying was wetter and warming. Climate change is likely to exacerbate grassland bird population declines because projected climate conditions include rising temperatures, more prolonged drought and more intense storms as the hydrological cycle is altered. Under varying realistic scenarios, nest success estimates were halved compared to their current average value when models both increased the temperature (3 °C) and decreased precipitation (two additional dry days during a nesting period), thus underscoring a sense of urgency in identifying and addressing the current causes of range-wide declines.

  7. Combined Heat and Power: A Decade of Progress, A Vision for the Future

    SciTech Connect

    none,

    2009-08-01

    Over the past 10 years, DOE has built a solid foundation for a robust CHP marketplace. We have aligned with key partners to produce innovative technologies and spearhead market-transforming projects. Our commercialization activities and Clean Energy Regional Application Centers have expanded CHP across the nation. More must be done to tap CHP’s full potential. Read more about DOE’s CHP Program in “Combined Heat and Power: A Decade of Progress, A Vision for the Future.”

  8. Intraday evaporation and heat fluxes variation at air-water interface of extremely shallow lakes in Chilean Andean Plateau

    NASA Astrophysics Data System (ADS)

    Vergara, Jaime; de la Fuente, Alberto

    2016-04-01

    Salars are landscapes formed by evapo-concentration of salts that usually have extremely shallow terminal lagoons (de la Fuente & Niño, 2010). They are located in the altiplanic region of the Andes Mountains of Chile, Argentina, Bolivia and Peru, and they sustain highly vulnerable and isolated ecosystems in the Andean Desert. These ecosystems are sustained by benthic primary production, which is directly linked to mass, heat and momentum transfer between the water column and the atmosphere (de la Fuente, 2014). Despite the importance of these transport processes across the air-water interface, there are few studies describing their intraday variation and how they are influenced by the stability of the atmospheric boundary layer in the altiplano. The main objective of this work is to analyze the intraday vertical transport variation of water vapor, temperature and momentum between the atmosphere and a shallow water body on Salar del Huasco located in northern Chile (20°19'40"S, 68°51'25"W). To achieve this goal, we measured atmospheric and water variables in a campaign realized on late October 2015, using high frequency meteorological instruments (a sonic anemometer with an incorporated infrared gas analyzer, and a standard meteorological station) and water sensors. From these data, we characterize the intraday variation of water vapor, temperature and momentum fluxes, we quantify the influence of the atmospheric boundary layer stability on them, and we estimate transfer coefficients associated to latent heat, sensible heat, hydrodynamic drag and vertical transport of water vapor. As first results, we found that latent and sensible heat fluxes are highly influenced by wind speed rather buoyancy, and we can identify four intraday intervals with different thermo-hydrodynamic features: (1) cooling under stable condition with wind speed near 0 from midnight until sunrise; (2) free convection with nearly no wind speed under unstable condition from sunrise until midday

  9. Are regional projections of extreme sea levels based on uncertain future MSL scenarios reliable? A case study for the south-eastern North Sea

    NASA Astrophysics Data System (ADS)

    Dangendorf, S.; Mudersbach, C.; Jensen, J.

    2012-12-01

    Recently a number of authors applied a method (offset method) to combine observations of present sea level extremes with projections of future sea level rise during the 21st century. The method provides a technique for estimating potential future exceedence probabilities based on the assumption that both variability and trends of extreme sea levels have been and will be driven by changes in MSL. This assumption has been confirmed for quasi-global (Woodworth et al. 2011) and regional data-sets (Marcos et al. 2009). However, if the assumption fails, the application of the method will result in large inaccuracies. In the present study, records from 13 tide gauges located in the German Bight, a part of the south-eastern North Sea, are investigated. Time series of extreme high sea levels, covering a period from 1900 to 2008, are analyzed relative to simultaneous changes in MSL. For that purpose in a first step only extreme sea levels have been analyzed, while in a second step MSL time series have been subtracted from the extremes to prove the evidence of trend and variability differences. The results point to a significantly stronger increase in extreme sea levels during the second half of the 20th century. While in the first half of the 20th century the evolution of extreme sea levels follows changes in MSL, in the second half a significant rise with values between 10 and 60 cm per century relative to the MSL has been observed. The divergent development varies seasonally. The largest deviations between extreme sea levels and the MSL have been detected during Season 1 [January to March], while considerably smaller but statistically significant changes have been observed during the remaining seasons. An investigation of reanalyzed datasets from the 20th century reanalysis project (20thCR) shows that large parts of the observed deviations are in phase with simultaneous changes in the local zonal extreme wind conditions and only small deviations remain. Using the above

  10. Computed and observed turbulent heat fluxes during an extreme Bora event in the Adriatic using atmosphere-ocean coupling

    NASA Astrophysics Data System (ADS)

    Ličer, Matjaž; Smerkol, Peter; Fettich, Anja; Ravdas, Michalis; Papapostolou, Alexandros; Mantziafou, Anneta; Strajnar, Benedikt; Cedilnik, Jure; Jeromel, Maja; Jerman, Jure; Petan, Sašo; Benetazzo, Alvise; Carniel, Sandro; Malačič, Vlado; Sofianos, Sarantis

    2016-04-01

    We have studied the performances of (a) a two-way coupled atmosphere-ocean modeling system and (b) one-way coupled ocean model (forced by the atmosphere model), as compared to the available in situ measurements during and after a strong Adriatic Bora wind event in February 2012, which led to extreme air-sea interactions. The simulations span the period between January and March 2012. The models used were ALADIN (4.4 km resolution) on the atmosphere side and Adriatic setup of POM (1°/30 × 1°/30 angular resolution) on the ocean side. The atmosphere-ocean coupling was implemented using the OASIS3-MCT model coupling toolkit. Two-way coupling ocean feedback to the atmosphere is limited to sea surface temperature. We have compared modeled atmosphere-ocean fluxes (computed using modified Louis scheme) and sea temperatures from both setups to platform and CTD measurements of fluxes (computed using COARE scheme) and temperatures from three observational platforms (Vida, Paloma, Acqua Alta) in the Northern Adriatic. We show that turbulent fluxes from both setups differ up to 20% during the Bora but not significantly before and after the event. The impact of the coupling on the ocean is significant while the impact on the atmosphere is less pronounced. When compared to observations, two way coupling ocean temperatures exhibit a four times lower RMSE than those from one-way coupled system. Two-way coupling improves sensible heat fluxes at all stations but does not improve latent heat loss.

  11. Exposure to extreme heat events is associated with increased hay fever prevalence among nationally represntatvie sample of us, Adults: 1997-2013

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Warmer temperature can alter seasonality of pollen as well as pollen concentration, and may impact allergic diseases such as hay fever. Recent studies suggest that extreme heat events will likely increase in frequency, intensity, and duration in coming decades. The overall objective of this study i...

  12. Identifying the Drivers and Occurrence of Historical and Future Extreme Air-quality Events in the United States Using Advanced Statistical Techniques

    NASA Astrophysics Data System (ADS)

    Porter, W. C.; Heald, C. L.; Cooley, D. S.; Russell, B. T.

    2013-12-01

    Episodes of air-quality extremes are known to be heavily influenced by meteorological conditions, but traditional statistical analysis techniques focused on means and standard deviations may not capture important relationships at the tails of these two respective distributions. Using quantile regression (QR) and extreme value theory (EVT), methodologies specifically developed to examine the behavior of heavy-tailed phenomena, we analyze extremes in the multi-decadal record of ozone (O3) and fine particulate matter (PM2.5) in the United States. We investigate observations from the Air Quality System (AQS) and Interagency Monitoring of Protected Visual Environments (IMPROVE) networks for connections to meteorological drivers, as provided by the National Center for Environmental Prediction (NCEP) North American Regional Reanalysis (NARR) product. Through regional characterization by quantile behavior and EVT modeling of the meteorological covariates most responsible for extreme levels of O3 and PM2.5, we estimate pollutant exceedance frequencies and uncertainties in the United States under current and projected future climates, highlighting those meteorological covariates and interactions whose influence on air-quality extremes differs most significantly from the behavior of the bulk of the distribution. As current policy may be influenced by air-quality projections, we then compare these estimated frequencies to those produced by NCAR's Community Earth System Model (CESM) identifying regions, covariates, and species whose extreme behavior may not be adequately captured by current models.

  13. Influence of land-atmosphere feedbacks on climate extreme indices in a multi-model experiment under present and future conditions (GLACE-CMIP5)

    NASA Astrophysics Data System (ADS)

    Lorenz, Ruth; Pitman, Andy; Seneviratne, Sonia

    2014-05-01

    Extreme events can be directly influenced by land surface-atmosphere interactions. It is important to investigate how extreme events might change in the future and the role these interactions play in amplifying extremes. The data from the GLACE-CMIP5 experiments (Seneviratne et al., 2013) provide a unique opportunity to examine the influence of soil moisture on extremes in transient climate simulations from a range of climate models. The extreme indices we use are defined by the Expert Team on Climate Change Detection and Indices (ETCCDI) and contain a range of indices based on daily minimum and maximum temperature as well as daily precipitation. The ETCCDI indices are available from observational datasets, reanalysis and as well as CMIP5 runs. Hence, these indices are widely used and can be compared to other sources. In this paper, we analyze the effects of land surface feedbacks on the extremes and their trends in the different global climate models. Seneviratne, S. I., et al. (2013). Impact of soil moisture-climate feedbacks on CMIP5 projections: First results from the GLACE-CMIP5 experiment. GRL, 40(19), 5212-5217. doi:10.1002/grl.50956

  14. The extreme drought episode of August 2011-May 2012: A scenario for future droughts in Central Europe?

    NASA Astrophysics Data System (ADS)

    Zahradníček, P.; Trnka, M.; Brázdil, R.; Mozny, M.; Stepanek, P.; Hlavinka, P.; Malý, A.; Dubrovsky, M.

    2014-12-01

    The weather conditions from August 2011 to May 2012 produced an extreme drought in the eastern Czech Republic (Moravia), whereas the patterns were nearly normal in its western region (Bohemia). The Southern and Central Moravia regions, which represent the most important agricultural areas, were most affected by the drought. The precipitation totals for the studied period were 50% to 70% of the long-term mean, which was calculated for 1961-2000. In autumn 2011, the total precipitation accounted for 10% to 30% of the long-term mean for most of Moravia, increasing to 30% to 50% in spring 2012. Moreover, 7.5% of the Czech Republic experienced a 100-year drought; 20% of the country experienced a 20-year drought. According to the Palmer Drought Severity Index, the 2012 drought was classified as the worst in the past 130 years. The drought patterns were related to the prevailing high-pressure systems over Central Europe and the occurrence of weather types with different precipitation amounts in Bohemia and Moravia. The most substantial drought effects occurred in the agricultural sector. A decrease in cereal yields was observed in the analyzed production areas in Moravia, which was unprecedented in the past 52 years. Moreover, winter crops were affected more than spring crops. An increased risk of fire occurred due to the drought conditions; the largest forest fire in the past 15 years was recorded during this period. Furthermore, signs of hydrological drought were also reported in rivers. The 2011-2012 drought was compared with the significant droughts in 2000, 2003 and 2007. Austria and Slovakia, which neighbor the Czech Republic, experienced a similar drought. This drought analysis can be used as a scenario for future droughts and their impacts in Central Europe due to the global warming projected by GCMs.Acknowledgements:This study was made possible by the generous support of the "Establishment of International Scientific Team Focused on Drought Research" project (no

  15. Southern Ocean heat and carbon uptake: mechanisms, recent trends, and future changes

    NASA Astrophysics Data System (ADS)

    Froelicher, T. L.

    2015-12-01

    The Southern Ocean's dominant influence on the global heat balance and nutrient and carbon cycles stems from the fact that it is the primary gateway through which Earth's cold, centuries old and nutrient rich deep and bottom waters interact with the atmosphere. The westerly winds in the Southern Hemisphere drive a strongly divergent surface flow that draws up water from below in a wide ring circling the Antarctic continent. In the first part of the talk, we assess the uptake, transport, and storage of oceanic anthropogenic carbon and heat in the Southern Ocean over the period 1861-2005 in a new set of carbon-climate Earth System Models. Simulations show that the Southern Ocean south of 30°S, covering only 30% of the global surface ocean area, accounts for more than 40% of global anthropogenic carbon uptake. Furthermore, the Southern Ocean takes up three quarters of the total excess heat generated by the increasing levels of greenhouse gases in the atmosphere. Anthropogenic carbon and heat storage show a common broad-scale pattern of change, but ocean heat storage is more structured than ocean carbon storage suggesting that different mechanisms are important. The Southern Ocean, however, remains the region where models differ the most in the representation of anthropogenic carbon and, in particular, heat uptake. While the Southern Ocean carbon uptake has increased considerably in recent decades, as expected based on the substantial increase in atmospheric CO2, there is considerable concern that this sink will saturate or even reverse in response to warming, changing ocean circulation and chemistry. In the second part of the talk, novel multi-millennial global warming simulations with a comprehensive Earth System Model under a 1% yr-1 atmospheric CO2 increase to 2xCO2 and constant forcing thereafter scenario will be used to explore future long-term changes in the Southern Ocean carbon uptake. We show that after full equilibration of the model with doubling of

  16. Downscaling future precipitation extremes to urban hydrology scales using a spatio-temporal Neyman-Scott weather generator

    NASA Astrophysics Data System (ADS)

    Jomo Danielsen Sørup, Hjalte; Bøssing Christensen, Ole; Arnbjerg-Nielsen, Karsten; Steen Mikkelsen, Peter

    2016-04-01

    Spatio-temporal precipitation is modelled for urban application at 1 h temporal resolution on a 2 km grid using a spatio-temporal Neyman-Scott rectangular pulses weather generator (WG). Precipitation time series used as input to the WG are obtained from a network of 60 tipping-bucket rain gauges irregularly placed in a 40 km × 60 km model domain. The WG simulates precipitation time series that are comparable to the observations with respect to extreme precipitation statistics. The WG is used for downscaling climate change signals from regional climate models (RCMs) with spatial resolutions of 25 and 8 km, respectively. Six different RCM simulation pairs are used to perturb the WG with climate change signals resulting in six very different perturbation schemes. All perturbed WGs result in more extreme precipitation at the sub-daily to multi-daily level and these extremes exhibit a much more realistic spatial pattern than what is observed in RCM precipitation output. The WG seems to correlate increased extreme intensities with an increased spatial extent of the extremes meaning that the climate-change-perturbed extremes have a larger spatial extent than those of the present climate. Overall, the WG produces robust results and is seen as a reliable procedure for downscaling RCM precipitation output for use in urban hydrology.

  17. Estimation and Uncertainty Analysis of Impacts of Future Heat Waves on Mortality in the Eastern United States

    SciTech Connect

    Wu, Jianyong; Zhou, Ying; Gao, Yang; Fu, Joshua S.; Johnson, Brent; Huang, Cheng; Kim, Young-Min; Liu, Yang

    2014-01-01

    Background: It is anticipated that climate change will influence heat-related mortality in the future. However, the estimation of excess mortality attributable to future heat waves is subject to large uncertainties, which have not been examined under the latest greenhouse gas emission scenarios. Objectives: We estimated the future heat wave impact on mortality in the eastern United States (~ 1,700 counties) under two Representative Concentration Pathways (RCPs) and analyzed the sources of uncertainties. Methods Using dynamically downscaled hourly temperature projections in 2057-2059, we calculated heat wave days and episodes based on four heat wave metrics, and estimated the excess mortality attributable to them. The sources of uncertainty in estimated excess mortality were apportioned using a variance-decomposition method. Results: In the eastern U.S., the excess mortality attributable to heat waves could range from 200-7,807 with the mean of 2,379 persons/year in 2057-2059. The projected average excess mortality in RCP 4.5 and 8.5 scenarios was 1,403 and 3,556 persons/year, respectively. Excess mortality would be relatively high in the southern and eastern coastal areas. The major sources of uncertainty in the estimates are relative risk of heat wave mortality, the RCP scenarios, and the heat wave definitions. Conclusions: The estimated mortality risks from future heat waves are likely an order of magnitude higher than its current level and lead to thousands of deaths each year under the RCP8.5 scenario. The substantial spatial variability in estimated county-level heat mortality suggests that effective mitigation and adaptation measures should be developed based on spatially resolved data.

  18. The Modified Rainfall Anomaly Index (mRAI)—is this an alternative to the Standardised Precipitation Index (SPI) in evaluating future extreme precipitation characteristics?

    NASA Astrophysics Data System (ADS)

    Hänsel, Stephanie; Schucknecht, Anne; Matschullat, Jörg

    2016-02-01

    Precipitation extremes affect various economic sectors and may result in substantial costs for societies. Future projections of such extreme occurrences are needed to successfully develop robust regional adaptation strategies. Model ensemble-based approaches provide a higher level of confidence since they compensate to some degree for the uncertainties of individual climate model projections. An ensemble of twelve regional climate projections from five regional climate models was used to evaluate the suitability of a modified version of the Rainfall Anomaly Index (mRAI) as an alternative to the Standardised Precipitation Index (SPI) in assessing future precipitation conditions. We compared frequency distributions and trends of the mRAI with the SPI for a test region that is climatologically representative of Central Eastern Europe. Both indices are highly correlated with each other at all tested timescales—both for stations and for regionally averaged data—with Pearson correlation coefficients >>0.9 and Spearman correlation coefficients >0.99. There are no significant differences in their frequency distributions, although the mRAI shows slightly higher frequencies in the classes of `moderately dry' to `very dry' conditions. The change signals revealed by SPI and mRAI are very similar for mean changes as well as for changes in the extremes. Considering the large bandwidth of change signals of individual regional climate projections, the mRAI provides sufficiently robust results for the evaluation of future precipitation anomaly trends. The notably more complex calculation of the SPI has no appreciable advantage for this application.

  19. Pelletization and encapsulation of general purpose heat source (GPHS) fueled clads for future space missions

    NASA Astrophysics Data System (ADS)

    Barklay, Chadwick D.; Miller, Roger G.; Malikh, Y.; Kalinovsky, A.; Aldoshin, A.

    1996-03-01

    Mankind must continue to explore the universe in order to gain a better understanding of how we relate to it and how we can best use its resources to our benefit. Because of the significant costs of this type of exploration, it can more effectively be accomplished through an international team effort. This unified effort must include the design, planning, and execution phases of future space missions, extending down to such activities as the processing, pelletization, and encapsulation of the fuel that will be used to support the spacecraft electrical power generation systems. Over the last 30 years, radioisotopes have provided heat from which electrical power is generated. For space missions, the isotope of choice has generally been 238PuO2, its long half-life making it ideal for supplying power to remote satellites and spacecraft like the Voyager, Pioneer, and Viking missions, as well as the recently launched Galileo and Ulysses missions, and the presently planned Cassini mission. Electric power for future space missions will be provided by either radioisotopic thermoelectric generators (RTG), radioisotope thermophotovoltaic systems (RTPV), radioisotope Stirling systems or a combination of these. However, all of the aforementioned systems will be thermally driven by General-Purpose Heat Source (GPHS) fueled clads in some configuration. Each GPHS fueled clad contains a 150-gram pellet of 238PuO2, and each pellet is encapsulated within an iridium-alloy shell. Historically, the fabrication of the iridium-alloy shells has been performed at EG&G Mound, and Oak Ridge National Laboratory, and the girth welding of the GPHS capsules has been performed at Westinghouse Savannah River Corporation, and Los Alamos National Laboratory. This paper describes a cost effective alternative method for the production of GPHS capsules. Fundamental considerations such as the potential production options, the associated support activities, and the methodology to transport the welded

  20. Assessing risks from drought and heat stress in productive grasslands under present and future climatic conditions

    NASA Astrophysics Data System (ADS)

    Calanca, Pierluigi; Mosimann, Eric; Meisser, Marco; Deléglise, Claire

    2014-05-01

    Grasslands cover the majority of the world's agricultural area, provide the feedstock for animal production, contribute to the economy of farms, and deliver a variety of ecological and societal services. Assessing responses of grassland ecosystems to climate change, in particular climate-related risks, is therefore an important step toward identifying adaptation options necessary to secure grassland functioning and productivity. Of particular concern are risks in relation to drought and extreme temperatures, on the one hand because grasslands are very sensitive to water stress, on the other hand also because global warming is expected to increase the occurrence and intensity of these events in many agricultural areas of the world. In this contribution we review findings of ongoing experimental and modelling activities that aim at examining the implications of climate extremes and climate change for grassland vegetation dynamics and herbage productivity. Data collected at the Jura foot in western Switzerland indicate that water scarcity and associated anomalous temperatures slowed plant development in relation to both the summer drought of 2003 as well as the spring drought of 2011, with decline in annual yields of up to 40%. Further effects of drought found from the analysis of recent field trials explicitly designed to study the effects of different water management regimes are changes in the functional composition and nutritive value of grasslands. Similar responses are disclosed by simulations with a process based grassland ecosystem model that was originally developed for the simulation of mixed grass/clover swards. Simulations driven with historical weather records from the Swiss Plateau suggest that drought and extreme temperature could represent one of the main reasons for the observed yield variability in productive systems. Simulations with climate change scenarios further reveal important changes in ecosystem dynamics for the current century. The results

  1. Impact of past and future climate variability and extreme events on carbon loss in European arable agriculture

    NASA Astrophysics Data System (ADS)

    Balkovic, Juraj; van der Velde, Marijn; Khabarov, Nikolay; Beer, Christian

    2013-04-01

    Predictions of climate models suggest an increase in climate variability and an increased probability in the occurrence of extreme weather events during this century. The expected increase in variability of meteorological variables such as temperature and precipitation will impact the productive functions as well as the ecosystem services agricultural systems provide, including the storage of soil organic carbon. Here we use a methodology and specifically tailored climate datasets that were developed in the EU FP7 CARBO-Extreme project to analyze the effect of increased climate variability on long term soil organic carbon sequestration, erosion and crop production in Europe. We quantified the changing impact of extreme events on carbon dynamics and soil organic carbon loss from agricultural soil cultivated with wheat, barley, maize and rye in Europe for the period from 1900-2100. In separate simulations we specifically address the potential losses of soil carbon associated with erosion. We further characterized the effect of CO2 fertilization on crop growth. Preliminary results indicate a growing contribution of extreme weather generally lowering biomass production and crop yields in Europe, albeit with regional variations. This decrease will lead to a relatively lower input of organic matter into the soil and generally lower soil organic carbon stocks. Yet, in areas characterized by relatively drier conditions the decomposition of organic material and thus heterotrophic transpiration is reduced which can result in a net accumulation of soil organic matter. Finally, we attempted to identify the cropland area susceptible to increased carbon loss due to climate extremes by unraveling the relative contribution of the combined spatial fingerprint of physiographic characteristics and climate extremes over Europe.

  2. Future joint probability behaviors of precipitation extremes across China: Spatiotemporal patterns and implications for flood and drought hazards

    NASA Astrophysics Data System (ADS)

    Li, Jianfeng; Zhang, Qiang; Chen, Yongqin David; Singh, Vijay P.

    2015-01-01

    Observed daily precipitation from 527 meteorology stations in China during 1960-2005, and simulated daily precipitation from five Earth System Models (ESMs) under historical, RCP2.6 and RCP8.5 scenarios from Coupled Model Intercomparison Project Phase 5 (CMIP5) datasets are analyzed to investigate joint probability behaviors of precipitation extremes in China during 2021-2050 and 2071-2100. Five joint return periods based on six extreme precipitation indices are defined. These joint return periods consider co-occurrence of extreme heavy and weak precipitation, as well as joint extreme heavy precipitation events in terms of different combinations of extreme precipitation amount, intensity, fractional contribution to annual precipitation days, and consecutive wet periods. Weather Generator Model (WGEN) is used to downscale the outputs of ESMs, and Copula is applied to construct joint probability distributions. The variations of joint return periods with 5-year marginal values (marginal values larger than their 5-year return period values respectively) and 20-year marginal values are discussed to represent changes in joint probability behaviors. Results show that: (1) during 1960-2005, spatial distributions of joint return periods with 5-year marginal values are similar to those with 20-year marginal values; (2) changes in marginal distributions and bivariate relationships between extreme indices may be the causes of joint probability distribution shift; (3) in general, during 2021-2050 and 2071-2100, there is less co-occurrence of consecutive wet and dry days, and more joint extreme heavy precipitation events with various aspects, implying less risk of co-occurrence of floods and droughts in the same year but higher risk of floods in China. But north China may face higher risk of co-occurrence of severe floods and droughts in the same year; and (4) changes in joint return periods under RCP8.5 are more remarkable than under RCP2.6. Even under RCP2.6, a scenario 2

  3. The contribution of urbanization to recent extreme heat events and white roof mitigation strategy in the Beijing-Tianjin-Hebei metropolitan area

    NASA Astrophysics Data System (ADS)

    Wang, Mingna

    2015-04-01

    The UHI effect can aggravate summertime heat waves and strongly influence human comfort and health, leading to greater mortality in metropolitan areas. Many geo-engineering technological strategies have been proposed to mitigate climate warming, and for the UHI, increasing the albedo of artificial urban surfaces (rooftops or pavements) has been considered a lucrative and effective way to cool cities. The objective of this work is to quantify the contribution of urbanization to recent extreme heat events of the early 21st century in the Beijing-Tianjin-Hebei metropolitan area, using the mesoscale WRF model coupled with a single urban canopy model and actual urban land cover datasets. This work also investigates a simulation of the regional effects of white roof technology by increasing the albedo of urban areas in the urban canopy model to mitigate the urban heat island, especially in extreme heat waves. The results show that urban land use characteristics that have evolved over the past ~20 years in the Beijing-Tianjin-Hebei metropolitan area have had a significant impact on the extreme temperatures occurring during extreme heat events. Simulations show that new urban development has caused an intensification and expansion of the areas experiencing extreme heat waves with an average increase in temperature of approximately 0.60°C. This change is most obvious at night with an increase up to 0.95°C, for which the total contribution of anthropogenic heat is 34%. We also simulate the effects of geo-engineering strategies increasing the albedo of urban roofs. White roofs reflect a large fraction of incoming sunlight in the daytime, which reduced the net radiation so that the roof surface keep at a lower temperature than regular solar-absorptive roofs. Urban net radiation decreases by approximately 200 W m-2 at local noon because of high solar reflectance of white roofs, which cools the daytime urban temperature afer sunrise, with the largest decrease of almost -0.80

  4. The Extreme Conditions Beamline at PETRA III, DESY: Possibilities to conduct time resolved monochromatic diffraction experiments in dynamic and laser heated DAC

    NASA Astrophysics Data System (ADS)

    Liermann, H.-P.; Morgenroth, W.; Ehnes, A.; Berghäuser, A.; Winkler, B.; Franz, H.; Weckert, E.

    2010-03-01

    We present plans for the new Extreme Conditions Beamline at PETRA III, DESY, Germany. The beamline is being designed and built with the specific goal to explore time resolved high-pressure and -temperature x-ray diffraction experiments in the dynamic and laser heated diamond anvil cell. Within we discuss the conceptual design of the optical components and experimental setup to conduct monochromatic high-pressure powder diffraction experiments in the sub-second time regime.

  5. Impact of urban WWTP and CSO fluxes on river peak flow extremes under current and future climate conditions.

    PubMed

    Keupers, Ingrid; Willems, Patrick

    2013-01-01

    The impact of urban water fluxes on the river system outflow of the Grote Nete catchment (Belgium) was studied. First the impact of the Waste Water Treatment Plant (WWTP) and the Combined Sewer Overflow (CSO) outflows on the river system for the current climatic conditions was determined by simulating the urban fluxes as point sources in a detailed, hydrodynamic river model. Comparison was made of the simulation results on peak flow extremes with and without the urban point sources. In a second step, the impact of climate change scenarios on the urban fluxes and the consequent impacts on the river flow extremes were studied. It is shown that the change in the 10-year return period hourly peak flow discharge due to climate change (-14% to +45%) was in the same order of magnitude as the change due to the urban fluxes (+5%) in current climate conditions. Different climate change scenarios do not change the impact of the urban fluxes much except for the climate scenario that involves a strong increase in rainfall extremes in summer. This scenario leads to a strong increase of the impact of the urban fluxes on the river system. PMID:23787302

  6. Heat emergencies

    MedlinePlus

    Heat emergencies or illnesses are caused by exposure to extreme heat and sun. Heat illnesses can be prevented by ... to regulate the temperature, and make a heat emergency more likely: Drinking alcohol before or during exposure ...

  7. Urban population vulnerability to climate extremes: mitigating urban heat through technology and water-sensitive urban design in Australian cities (Invited)

    NASA Astrophysics Data System (ADS)

    Tapper, N. J.

    2013-12-01

    Australia recently endured what was arguably its worst drought in 200 years. The 'Millennium Drought' lasted from 1999 until 2009, producing acute water shortages for several major Australian cities. Towards the end of the drought an extreme heat wave with temperatures approaching 50 C claimed the lives of several hundred people in Melbourne and Adelaide. One outcome of the extreme conditions was that the spectre of climate change and its impacts became very real for most Australians and contributed to the 2007 signing of the Kyoto Protocol by the Australian Government. Issues of extreme heat and water security also led to increased interest in adapting Australian cities to climate change. These concerns ultimately led to the establishment of the Australian Cooperative Research Centre (CRC) for Water Sensitive Cities, a $110 million research initiative to utilise storm water in Australian cities to create cooler and more liveable environments with increased levels of water security. This paper provides an overview of the work being undertaken within the urban climate program of the CRC to identify heat-health vulnerability in our cities and to evaluate the efficacy of irrigated green infrastructure to produce more liveable environments. This papers discusses some of the early research outputs that involve measurement, modelling and remote sensing at a range of scales in Australian cities.

  8. District heating and cooling systems of the future: Strategies for global change

    SciTech Connect

    McCabe, R.E.

    1996-12-31

    The future of district heating and cooling, also known as district energy, will be a function of economic and regulatory forces in the US. Typically a district energy system provides thermal energy in the form of steam, hot water, or chilled water from a central plant, and distributes the energy through pipes to two or more buildings. At the present time, district energy is under-utilized and serves only 1.3 percent of US energy needs, providing a total of 1.1 quadrillion Btu of energy annually. A brief review of the historical development of district energy, the status of the technology in the US, and a few basics on world energy consumption lead in to the economic and environmental advantages of district energy. District energy systems have been retrofitted to comply wit h the regulations of the Clean Air Act (CAA); presently emissions of greenhouse gases, such as CO{sub 2}, are not regulated by the CAA. If the results of ongoing investigation on global climate change determine that regulation is warranted, several strategies exist for district energy systems to offer significant reductions in greenhouse gas emissions. Projections of district energy`s reaction to the ongoing forces are possible with the use of energy consumption forecasts through the year 2015, and a discussion of trend setting concepts being applied involving: gas turbines, cogeneration, fuel cells, chillers, advanced transmission fluids, renewable energies, and CO{sub 2} capture. District energy has potential to be an important part of the evolving strategies for global climate change. For this reason, combined with technology advancements and a supportive economic climate, a new era in district energy has begun. Growth and development of district energy into the foreseeable future is expected to be strong.

  9. Influence of Solar and Thermal Radiation on Future Heat Stress Using CMIP5 Archive Driving the Community Land Model Version 4.5

    NASA Astrophysics Data System (ADS)

    Buzan, J. R.; Huber, M.

    2015-12-01

    The summer of 2015 has experienced major heat waves on 4 continents, and heat stress left ~4000 people dead in India and Pakistan. Heat stress is caused by a combination of meteorological factors: temperature, humidity, and radiation. The International Organization for Standardization (ISO) uses Wet Bulb Globe Temperature (WBGT)—an empirical metric this is calibrated with temperature, humidity, and radiation—for determining labor capacity during heat stress. Unfortunately, most literature studying global heat stress focuses on extreme temperature events, and a limited number of studies use the combination of temperature and humidity. Recent global assessments use WBGT, yet omit the radiation component without recalibrating the metric.Here we explicitly calculate future WBGT within a land surface model, including radiative fluxes as produced by a modeled globe thermometer. We use the Community Land Model version 4.5 (CLM4.5), which is a component model of the Community Earth System Model (CESM), and is maintained by the National Center for Atmospheric Research (NCAR). To drive our CLM4.5 simulations, we use greenhouse gasses Representative Concentration Pathway 8.5 (business as usual), and atmospheric output from the CMIP5 Archive. Humans work in a variety of environments, and we place the modeled globe thermometer in a variety of environments. We modify CLM4.5 code to calculate solar and thermal radiation fluxes below and above canopy vegetation, and in bare ground. To calculate wet bulb temperature, we implemented the HumanIndexMod into CLM4.5. The temperature, wet bulb temperature, and radiation fields are calculated at every model time step and are outputted 4x Daily. We use these fields to calculate WBGT and labor capacity for two time slices: 2026-2045 and 2081-2100.

  10. Liquid droplet radiator development status. [waste heat rejection devices for future space vehicles

    NASA Technical Reports Server (NTRS)

    White, K. Alan, III

    1987-01-01

    Development of the Liquid Droplet Radiator (LDR) is described. Significant published results of previous investigators are presented, and work currently in progress is discussed. Several proposed LDR configurations are described, and the rectangular and triangular configurations currently of most interest are examined. Development of the droplet generator, collector, and auxiliary components are discussed. Radiative performance of a droplet sheet is considered, and experimental results are seen to be in very good agreement with analytical predictions. The collision of droplets in the droplet sheet, the charging of droplets by the space plasma, and the effect of atmospheric drag on the droplet sheet are shown to be of little consequence, or can be minimized by proper design. The LDR is seen to be less susceptible than conventional technology to the effects of micrometeoroids or hostile threats. The identification of working fluids which are stable in the orbital environments of interest is also made. Methods for reducing spacecraft contamination from an LDR to an acceptable level are discussed. Preliminary results of microgravity testing of the droplet generator are presented. Possible future NASA and Air Force missions enhanced or enabled by a LDR are also discussed. System studies indicate that the LDR is potentially less massive than heat pipe radiators. Planned microgravity testing aboard the Shuttle or space station is seen to be a logical next step in LDR development.

  11. Comparison of statistical and dynamical downscaling of extreme precipitations over France in present-day and future climate

    NASA Astrophysics Data System (ADS)

    Colin, Jeanne; Déqué, Michel; Sanchez Gomez, Emila; Somot, Samuel

    2010-05-01

    We present a comparison of two downscaling methods of extreme precipitations over France at a climatic time scale : a dynamical one performed with the Regional Climate Model ALADIN-Climate used at a resolution of 12 km, and a statistical one based on the weather regime approach and using the analog methodology to reconstruct daily fields of precipitations at a 8 km resolution. We focus on the most heavy precipitations of the area of interest, which occur in southeastern France in Autumn. Those involve small-scale processes than can be explicitly resolved only with 2-1 km resolution non-hydrostatic models. However, such models can not be used for climate simulations because of their computational cost is still too high. Yet these extreme events cause rather heavy damages, so that their possible evolution in the context of climate change is of great concern. Thus, there is strong need in assessing downscaling methods' ability to represent them. First, we downscale the low-resolution ERA40 re-analysis over the 1958-2000 time period with ALADIN-Climate, and from the year 1980 to the year 2000 with the statistical method. Then, we apply a quantile-quantile correction to the daily precipitations of the last twenty years of the ALADIN-Climate simulation. The correction rates are computed over the first part of the simulation (1958-1979) using a high-resolution gridded database : the SAFRAN analysis, which provides series of hourly fields for the 1958-2008 period over the french territory at a 8 km resolution. We assess the performances of each downscaling method in present-day climate by comparing the simulated precipitations to the SAFRAN database. The use of the ERA40 re-analysis allows to reproduce the real chronology in both downscalings, which enables to analyze the results not only from a statistical point of view but also through day-to-day diagnosis such as time correlations or spatial patterns of rain for given extreme events. Secondly, we apply these downscaling

  12. Uncertainty and extreme events in future climate and hydrologic projections for the Pacific Northwest: providing a basis for vulnerability and core/corridor assessments

    USGS Publications Warehouse

    Littell, Jeremy S.; Mauger, Guillaume S.; Salathe, Eric P.; Hamlet, Alan F.; Lee, Se-Yeun; Stumbaugh, Matt R.; Elsner, Marketa; Norheim, Robert; Lutz, Eric R.; Mantua, Nathan J.

    2014-01-01

    The purpose of this project was to (1) provide an internally-consistent set of downscaled projections across the Western U.S., (2) include information about projection uncertainty, and (3) assess projected changes of hydrologic extremes. These objectives were designed to address decision support needs for climate adaptation and resource management actions. Specifically, understanding of uncertainty in climate projections – in particular for extreme events – is currently a key scientific and management barrier to adaptation planning and vulnerability assessment. The new dataset fills in the Northwest domain to cover a key gap in the previous dataset, adds additional projections (both from other global climate models and a comparison with dynamical downscaling) and includes an assessment of changes to flow and soil moisture extremes. This new information can be used to assess variations in impacts across the landscape, uncertainty in projections, and how these differ as a function of region, variable, and time period. In this project, existing University of Washington Climate Impacts Group (UW CIG) products were extended to develop a comprehensive data archive that accounts (in a reigorous and physically based way) for climate model uncertainty in future climate and hydrologic scenarios. These products can be used to determine likely impacts on vegetation and aquatic habitat in the Pacific Northwest (PNW) region, including WA, OR, ID, northwest MT to the continental divide, northern CA, NV, UT, and the Columbia Basin portion of western WY New data series and summaries produced for this project include: 1) extreme statistics for surface hydrology (e.g. frequency of soil moisture and summer water deficit) and streamflow (e.g. the 100-year flood, extreme 7-day low flows with a 10-year recurrence interval); 2) snowpack vulnerability as indicated by the ratio of April 1 snow water to cool-season precipitation; and, 3) uncertainty analyses for multiple climate

  13. Quantifying and Reducing the Uncertainties in Future Projections of Droughts and Heat Waves for North America that Result from the Diversity of Models in CMIP5

    NASA Astrophysics Data System (ADS)

    Herrera-Estrada, J. E.; Sheffield, J.

    2014-12-01

    There are many sources of uncertainty regarding the future projections of our climate, including the multiple possible Representative Concentration Pathways (RCPs), the variety of climate models used, and the initial and boundary conditions with which they are run. Moreover, it has been shown that the internal variability of the climate system can sometimes be of the same order of magnitude as the climate change signal or even larger for some variables. Nonetheless, in order to help inform stakeholders in water resources and agriculture in North America when developing adaptation strategies, particularly for extreme events such as droughts and heat waves, it is necessary to study the plausible range of changes that the region might experience during the 21st century. We aim to understand and reduce the uncertainties associated with this range of possible scenarios by focusing on the diversity of climate models involved in the Coupled Model Intercomparison Project Phase 5 (CMIP5). Data output from various CMIP5 models is compared against near surface climate and land-surface hydrological data from the North American Land Data Assimilation System (NLDAS)-2 to evaluate how well each climate model represents the land-surface processes associated with droughts and heat waves during the overlapping historical period (1979-2005). These processes include the representation of precipitation and radiation and their partitioning at the land surface, land-atmosphere interactions, and the propagation of signals of these extreme events through the land surface. The ability of the CMIP5 models to reproduce these important physical processes for regions of North America is used to inform a multi-model ensemble in which models that represent the processes relevant to droughts and heat waves better are given more importance. Furthermore, the future projections are clustered to identify possible dependencies in behavior across models. The results indicate a wide range in performance

  14. Responses of the bed bug, Cimex lectularius, to temperature extremes and dehydration: levels of tolerance, rapid cold hardening and expression of heat shock proteins.

    PubMed

    Benoit, J B; Lopez-Martinez, G; Teets, N M; Phillips, S A; Denlinger, D L

    2009-12-01

    This study of the bed bug, Cimex lectularius, examines tolerance of adult females to extremes in temperature and loss of body water. Although the supercooling point (SCP) of the bed bugs was approximately -20 degrees C, all were killed by a direct 1 h exposure to -16 degrees C. Thus, this species cannot tolerate freezing and is killed at temperatures well above its SCP. Neither cold acclimation at 4 degrees C for 2 weeks nor dehydration (15% loss of water content) enhanced cold tolerance. However, bed bugs have the capacity for rapid cold hardening, i.e. a 1-h exposure to 0 degrees C improved their subsequent tolerance of -14 and -16 degrees C. In response to heat stress, fewer than 20% of the bugs survived a 1-h exposure to 46 degrees C, and nearly all were killed at 48 degrees C. Dehydration, heat acclimation at 30 degrees C for 2 weeks and rapid heat hardening at 37 degrees C for 1 h all failed to improve heat tolerance. Expression of the mRNAs encoding two heat shock proteins (Hsps), Hsp70 and Hsp90, was elevated in response to heat stress, cold stress and during dehydration and rehydration. The response of Hsp90 was more pronounced than that of Hsp70 during dehydration and rehydration. Our results define the tolerance limits for bed bugs to these commonly encountered stresses of temperature and low humidity and indicate a role for Hsps in responding to these stresses. PMID:19941608

  15. Extreme Halophiles and Carbon Monoxide: Looking Through Windows at Earth's Past and Towards a Future on Mars

    NASA Astrophysics Data System (ADS)

    King, G.

    2015-12-01

    Carbon monoxide, which is ubiquitous on Earth, is the 2nd most abundant molecule in the universe. Members of the domain Bacteria have long been known to oxidize it, and activities of CO oxidizers in soils have been known for several decades to contribute to tropospheric CO regulation. Nonetheless, the diversity of CO oxidizers and their evolutionary history remain largely unknown. A molybdenum-dependent dehydrogenase (Mo-CODH) couples CO oxidation by most terrestrial and marine bacteria to either O2 or nitrate. Molybdenum dependence, the requirement for O2 and previous phylogenetic inferences have all supported a relatively late evolution for "aerobic" CO oxidation, presumably after the Great Oxidation Event (GOE) about 2.3 Gya. Although conundrums remain, recent discoveries suggest that Mo-CODH might have evolved before the GOE, and prior to the Bacteria-Archaea split. New phylogenetic analyses incorporating sequences from extremely halophilic CO-oxidizing Euryarchaeota isolated from salterns in the Atacama Desert, brines on Hawai`i and from the Bonneville Salt Flat suggest that Mo-CODH was present in an ancestor shared by Bacteria and Archaea. This observation is consistent with results of phylogenetic histories of genes involved in Mo-cofactor synthesis, and findings by others that Mo-nitrogenase was likely active > 3 Gya. Thus, analyses of Mo-dependent CO oxidizers provide a window on the past by raising questions about the availability of Mo and non-O2 electron acceptors. Extremely halophilic CO oxidizers also provide insights relevant for understanding the potential for extraterrestrial life. CO likely occurred at high concentrations in Mars' early atmosphere, and it occurs presently at about 800 ppm. At such high concentrations, CO represents one of the most abundant energy sources available for near-surface regolith. However, use of CO by an extant or transplanted Mars microbiota would require tolerance of low water potentials and high salt concentrations

  16. Simulated Extreme Prepitation Indices over Northeast Brasil in Current Climate and Future Scenarios RCP4.5 and RCP8.5

    NASA Astrophysics Data System (ADS)

    Wender Santiago Marinho, Marcos; Araújo Costa, Alexandre; Cassain Sales, Domingo; Oliveira Guimarães, Sullyandro; Mariano da Silva, Emerson; das Chagas Vasconcelos Júnior, Francisco

    2013-04-01

    In this study, we analyzed extreme precipitation indices, for present and future modeled climates over Northeast of Brazil (NEB), from CORDEX simulations over the domain of Tropical Americas. The period for the model validation was from 1989-2007, using data from the European Center (ECWMF) Reanalysis, ERA-INTERIM, as input to drive the regional model (RAMS 6.0). Reanalysis data were assimilated via both lateral boundaries and the entire domain (a much weaker "central nudging"). Six indices of extreme precipitation were calculated over NEB: the average number of days above 10, 20 and 30 mm in one year (R10, R20, R30), the number of consecutive dry days (CDD), the number of consecutive wet days (CWD) and the maximum rainfall in five consecutive days (RX5). Those indices were compared against two independent databases: MERRA (Modern Era Retrospective analysis for Research and Applications) and TRMM (Tropical Rainfall Measuring Mission). After validation, climate simulations were performed for the present climate (1985-2005) and short-term (2015-2035), mid-term (2045-2065) and long-term (2079 to 2099) future climates for two scenarios: RCP 4.5 and RCP 8.5, nesting RAMS into HadGEM2-ES global model (a participant of CMIP5). Along with the indices, we also calculated Probability Distribution Functions (PDFs) to study the behavior of daily precipitation in the present and by the end of the 21st century (2079 to 2099) to assess possible changes under RCPs 4.5 and 8.5. The regional model is capable of representing relatively well the extreme precipitation indices for current climate, but there is some difficulties in performing a proper validation since the observed databases disagree significantly. Future projections show significant changes in most extreme indices. Rnn generally tend to increase, especially under RCP8.5. More significant changes are projected for the long-term period, under RCP8.5, which shows a pronounced R30 enhancement over northern states. CDD tends

  17. Development of National Future Extreme Heat Scenario to Enable the Assessment of Climate Impacts on Public Health

    NASA Technical Reports Server (NTRS)

    Quattrochi, Dale A.; Cresson, William L.; Al-Hamdan, Mohammad Z.; Estes, Maurice G.

    2013-01-01

    The project's emphasis is on providing assessments of the magnitude, frequency and geographic distribution of EHEs to facilitate public health studies. We focus on the daily to weekly time scales on which EHEs occur, not on decadal-scale climate changes. There is, however, a very strong connection between air temperature patterns at the two time scales and long-term climatic changes will certainly alter the frequency of EHEs.

  18. Application of probabilistic event attribution in the summer heat extremes in the western US to emissions traced to major industrial carbon producers

    NASA Astrophysics Data System (ADS)

    Mera, R. J.; Allen, M. R.; Mote, P.; Ekwurzel, B.; Frumhoff, P. C.; Rupp, D. E.

    2015-12-01

    Heat waves in the western US have become progressively more severe due to increasing relative humidity and nighttime temperatures, increasing the health risks of vulnerable portions of the population, including Latino farmworkers in California's Central Valley and other socioeconomically disadvantaged communities. Recent research has shown greenhouse gas emissions doubled the risk of the hottest summer days during the 2000's in the Central Valley, increasing public health risks and costs, and raising the question of which parties are responsible for paying these costs. It has been argued that these costs should not be taken up solely by the general public through taxation, but that additional parties can be considered, including multinational corporations who have extracted and marketed a large proportion of carbon-based fuels. Here, we apply probabilistic event attribution (PEA) to assess the contribution of emissions traced to the world's 90 largest major industrial carbon producers to the severity and frequency of these extreme heat events. Our research uses very large ensembles of regional climate model simulations to calculate fractional attribution of policy-relevant extreme heat variables. We compare a full forcings world with observed greenhouse gases, sea surface temperatures and sea ice extent to a counter-factual world devoid of carbon pollution from major industrial carbon producers. The results show a discernable fraction of record-setting summer temperatures in the western US during the 2000's can be attributed to emissions sourced from major carbon producers.

  19. Using a Clean Energy Version of Moore's Law to Plan for the Extreme Efficiency of the Future

    NASA Astrophysics Data System (ADS)

    van Buskirk, Robert

    2014-03-01

    In 1965, Gordon Moore predicted a decade of exponential growth in the transistor density growth (and hence computing power) for integrated circuits that--with some modification--has held to the present day. In this talk, we discuss to what extent clean energy technologies are subject to similar laws of long term exponential improvement and how these improvement rates may be accelerating due to recent developments. We review a range of long term energy efficiency and technology productivity improvement trends ranging from lighting, televisions, refrigerators, HVAC, batteries, motors, power electronics and solar PV. After reviewing historical and recent trends, we discuss several factors that may lead to an acceleration of improvement rates in the clean energy technology sector. Finally, we discuss the Baumol effect which predicts how differential trends in technology productivity may affect trends in relative prices in the economy. We conclude with a discussion of some of the implications that Baumol's theories may have for the development of extreme levels of energy efficiency in the coming decades.

  20. Evidence of prehistoric flooding and the potential for future extreme flooding at Coyote Wash, Yucca Mountain, Nye County, Nevada

    USGS Publications Warehouse

    Glancy, Patrick A.

    1994-01-01

    Coyote Wash, east of Yucca Mountain and southwest of the Nevada Test Site, is the potential location for an exploratory shaft to investigate the feasibility of underground storage of radioactive waste. The potential for flooding and related fluvial-debris hazards was investigated with respect to the potential shaft location. Trenches excavated through fluvial sediment deposits revealed interstratified rock detritus emplaced by floods and debris flows. Most of the deposits are believed to be of late Quaternary age. Debros-flow deposits contain boulders as large as 3 feet in diameter. This evidence of intense prehistoric flooding and debris movement indicates the possibility of similar continuing activity. Empirical estimates of extreme flood flows in North Fork Coyote Wash, a 0.094- square-mile drainage to the shaft site, range from 900 to 2,600 cubic feet per second. Current (1992) knowledge indicates that flows of water and debris as much as 2,500 cubic feet per second can occur in the vicinity of the shaft from this drainage. Similar size flows from adjacent South Fork Coyote Wash, could arrive simultaneously in the vicinity of the shaft. Thus, cumulative water and debris from both tributaries could subject the alluvial flood plain near the shaft site to flows of as much as 5,000 cubic feet per second.

  1. Tuning extreme ultraviolet emission for optimum coupling with multilayer mirrors for future lithography through control of ionic charge states

    SciTech Connect

    Ohashi, Hayato Higashiguchi, Takeshi Suzuki, Yuhei; Kawasaki, Masato; Li, Bowen; Dunne, Padraig; O'Sullivan, Gerry; Kanehara, Tatsuhiko; Aida, Yuya; Nakamura, Nobuyuki; Torii, Shuichi; Makimura, Tetsuya; Jiang, Weihua

    2014-01-21

    We report on the identification of the optimum plasma conditions for a laser-produced plasma source for efficient coupling with multilayer mirrors at 6.x nm for beyond extreme ultraviolet lithography. A small shift to lower energies of the peak emission for Nd:YAG laser-produced gadolinium plasmas was observed with increasing laser power density. Charge-defined emission spectra were observed in electron beam ion trap (EBIT) studies and the charge states responsible identified by use of the flexible atomic code (FAC). The EBIT spectra displayed a larger systematic shift of the peak wavelength of intense emission at 6.x nm to longer wavelengths with increasing ionic charge. This combination of spectra enabled the key ion stage to be confirmed as Gd{sup 18+}, over a range of laser power densities, with contributions from Gd{sup 17+} and Gd{sup 19+} responsible for the slight shift to longer wavelengths in the laser-plasma spectra. The FAC calculation also identified the origin of observed out-of-band emission and the charge states responsible.

  2. Temperature acclimation rate of aerobic scope and feeding metabolism in fishes: implications in a thermally extreme future.

    PubMed

    Sandblom, Erik; Gräns, Albin; Axelsson, Michael; Seth, Henrik

    2014-11-01

    Temperature acclimation may offset the increased energy expenditure (standard metabolic rate, SMR) and reduced scope for activity (aerobic scope, AS) predicted to occur with local and global warming in fishes and other ectotherms. Yet, the time course and mechanisms of this process is little understood. Acclimation dynamics of SMR, maximum metabolic rate, AS and the specific dynamic action of feeding (SDA) were determined in shorthorn sculpin (Myoxocephalus scorpius) after transfer from 10°C to 16°C. SMR increased in the first week by 82% reducing AS to 55% of initial values, while peak postprandial metabolism was initially greater. This meant that the estimated AS during peak SDA approached zero, constraining digestion and leaving little room for additional aerobic processes. After eight weeks at 16°C, SMR was restored, while AS and the estimated AS during peak SDA recovered partly. Collectively, this demonstrated a considerable capacity for metabolic thermal compensation, which should be better incorporated into future models on organismal responses to climate change. A mathematical model based on the empirical data suggested that phenotypes with fast acclimation rates may be favoured by natural selection as the accumulated energetic cost of a slow acclimation rate increases in a warmer future with exacerbated thermal variations. PMID:25232133

  3. Measuring the Dayside Thermospheric Resonse to Extreme Joule Heating Events Using SuperDARN and TIMED GUVI

    NASA Astrophysics Data System (ADS)

    Baker, J. B.; Greenwald, R. A.; Paxton, L. J.; Zhang, Y.; Ruohoniemi, J. M.; Oksavik, K.

    2005-12-01

    A major goal of the NASA TIMED spacecraft is to understand the transfer of energy from the magnetosphere into the Mesosphere-Lower-Thermosphere-Ionosphere (MLTI) region. Joule and auroral particle heating at high latitudes are two processes by which magnetospheric energy can be deposited within the MLTI. In this session, we will present large-scale maps of dayside Joule heating rates obtained by combining ionospheric electric field measurements from the Super Dual Auroral Radar Network (SuperDARN) with estimates for the ionospheric Pedersen conductance obtained from TIMED Global Ultraviolet Imager (GUVI) auroral images. These Joule heating maps will be compared with maps of the GUVI O/N2 ratio, thereby providing a measure of the change in thermospheric composition associated with the Joule heating events and the subsequent transport of those perturbations via neutral winds.

  4. A Study of Heat Stress in Extremely Hot Environments, and the Infra-red Reflectance of Some Potential Shielding Materials

    PubMed Central

    Lewis, Charles E.; Scherberger, Richard F.; Miller, Franklin A.

    1960-01-01

    In the course of evaluating industrial heat exposures, three very hot environments having heat stress indices over 300 have been analysed by the techniques of Haines and Hatch (1952) and Belding and Hatch (1955). In addition, pulse and oral temperature measurements were made on three subjects exposed to these environments. These studies indicate that the methods of Haines and Hatch and Belding and Hatch tend to err on the side of safety when applied to very hot areas. Safe exposure times calculated by their techniques are approximately one-third those determined by either physiological measurement or by safe tolerance curves recommended by the American Society of Heating and Ventilation Engineers (ASHVE). The intelligent use of shielding as a method of protecting workers from radiant heat requires a knowledge of the infra-red reflectance curves of common industrial materials. Nineteen such curves are included. Images PMID:14416497

  5. Management of climatic heat stress risk in construction: a review of practices, methodologies, and future research.

    PubMed

    Rowlinson, Steve; Yunyanjia, Andrea; Li, Baizhan; Chuanjingju, Carrie

    2014-05-01

    Climatic heat stress leads to accidents on construction sites brought about by a range of human factors emanating from heat induced illness, and fatigue leading to impaired capability, physical and mental. It is an occupational characteristic of construction work in many climates and the authors take the approach of re-engineering the whole safety management system rather than focusing on incremental improvement, which is current management practice in the construction industry. From a scientific viewpoint, climatic heat stress is determined by six key factors: (1) air temperature, (2) humidity, (3) radiant heat, and (4) wind speed indicating the environment, (5) metabolic heat generated by physical activities, and (6) "clothing effect" that moderates the heat exchange between the body and the environment. By making use of existing heat stress indices and heat stress management processes, heat stress risk on construction sites can be managed in three ways: (1) control of environmental heat stress exposure through use of an action-triggering threshold system, (2) control of continuous work time (CWT, referred by maximum allowable exposure duration) with mandatory work-rest regimens, and (3) enabling self-paced working through empowerment of employees. Existing heat stress practices and methodologies are critically reviewed and the authors propose a three-level methodology for an action-triggering, localized, simplified threshold system to facilitate effective decisions by frontline supervisors. The authors point out the need for "regional based" heat stress management practices that reflect unique climatic conditions, working practices and acclimatization propensity by local workers indifferent geographic regions. The authors set out the case for regional, rather than international, standards that account for this uniqueness and which are derived from site-based rather than laboratory-based research. PMID:24079394

  6. Large scale and sub-regional connections in the lead up to summer heat wave and extreme rainfall events in eastern Australia

    NASA Astrophysics Data System (ADS)

    Boschat, Ghyslaine; Pezza, Alexandre; Simmonds, Ian; Perkins, Sarah; Cowan, Tim; Purich, Ariaan

    2015-04-01

    Australia has been exposed to a vast array of extreme weather regimes over the past few years, and the frequency and intensity of these events are expected to increase as a result of anthropogenic climate change. However, the predictability of extreme droughts, heat waves (HWs), bushfires and floods, is still hampered by our inability to fully understand how these weather systems interact with each other and with the climate system. This study brings new insight into the regional and large scale dynamics of some extreme events in Australia, by describing and comparing the climate signature of summer HWs and extreme rainfall events which have occurred in the states of Victoria and Queensland respectively, during 1979-2013. Our analyses highlight the importance of mid-latitude dynamics operating during HWs, in contrast with more tropical interactions at play during extreme rainfall events. A `common' blocking high pressure system is observed over the Tasman Sea during the two types of extreme events, and may explain why some southeastern HWs (only about 25 %) occur in close succession with floods in Queensland. However, our results suggest that there is no dynamical link between these two types of events, since the HW-related anticyclone evolves as part of a baroclinic wave train, whereas in the case of rainfall events, this structure emerges as an equivalent barotropic response to tropical convection. Sub-regional surface temperatures and air-sea fluxes also suggest that distinct processes may be operating in the lead up to these two events. Indeed, HWs tend to occur when the wave train propagates from the south Indian to the Pacific Ocean, inducing a quasi-stationary blocking high system over the Tasman Sea. This anticyclonic anomaly can then advect hot dry air towards the southern Victorian coast, where it produces HW conditions. On the other hand, extreme rainfall events mostly occur when the background conditions correspond to a La Niña state. The convection

  7. Evidence of prehistoric flooding and the potential for future extreme flooding at Coyote Wash, Yucca Mountain, Nye County, Nevada

    SciTech Connect

    Glancy, P.A.

    1994-09-01

    Coyote Wash, an approximately 0.3-square-mile drainage on the eastern flank of Yucca Mountain, is the potential location for an exploratory shaft to evaluate the suitability of Yucca Mountain for construction of an underground repository for the storage of high-level radioactive wastes. An ongoing investigation is addressing the potential for hazards to the site and surrounding areas from flooding and related fluvial-debris movement. Unconsolidated sediments in and adjacent to the channel of North Fork Coyote Wash were examined for evidence of past floods. Trenches excavated across and along the valley bottom exposed multiple flood deposits, including debris-flow deposits containing boulders as large as 2 to 3 feet in diameter. Most of the alluvial deposition probably occurred during the late Quaternary. Deposits at the base of the deepest trench overlie bedrock and underlie stream terraces adjacent to the channel; these sediments are moderately indurated and probably were deposited during the late Pleistocene. Overlying nonindurated deposits clearly are younger and may be of Holocene age. This evidence of intense flooding during the past indicates that severe flooding and debris movement are possible in the future. Empirical estimates of large floods of the past range from 900 to 2,600 cubic feet per second from the 0.094-square-mile drainage area of North Fork Coyote Wash drainage at two proposed shaft sites. Current knowledge indicates that mixtures of water and debris are likely to flow from North Fork Coyote Wash at rates up to 2,500 cubic feet per second. South Fork Coyote Wash, which has similar basin area and hydraulic characteristics, probably will have concurrent floods of similar magnitudes. The peak flow of the two tributaries probably would combine near the potential sites for the exploratory shaft to produce future flow of water and accompanying debris potentially as large as 5,000 cubic feet per second.

  8. Exploring Mbar shock conditions and isochorically heated aluminum at the Matter in Extreme Conditions end station of the Linac Coherent Light Source

    DOE PAGESBeta

    Doppner, T.; LePape, S.; Ma, T.; Pak, A.; Turnbull, D.; Fletcher, L. B.; Lee, H. J.; Galtier, E.; Nagler, B.; Gauthier, M.; et al

    2014-08-11

    Recent experiments performed at the Matter in Extreme Conditions end station of the Linac Coherent Light Source (LCLS) have demonstrated the first spectrally resolved measurements of plasmons from isochorically heated aluminum. The experiments have been performed using a seeded 8-keV x-ray laser beam as a pump and probe to both volumetrically heat and scatterx-rays from aluminum. Collective x-ray Thomson scattering spectra show a well-resolved plasmon feature that is down-shifted in energy by 19 eV. In addition, Mbar shock pressures from laser-compressed aluminum foils using velocity interferometer system for any reflector have been measured. Furthermore, the combination of experiments fully demonstratesmore » the possibility to perform warm dense matter studies at the LCLS with unprecedented accuracy and precision.« less

  9. Exploring Mbar shock conditions and isochorically heated aluminum at the Matter in Extreme Conditions end station of the Linac Coherent Light Source (invited)a)

    NASA Astrophysics Data System (ADS)

    Fletcher, L. B.; Lee, H. J.; Barbrel, B.; Gauthier, M.; Galtier, E.; Nagler, B.; Döppner, T.; LePape, S.; Ma, T.; Pak, A.; Turnbull, D.; White, T.; Gregori, G.; Wei, M.; Falcone, R. W.; Heimann, P.; Zastrau, U.; Hastings, J. B.; Glenzer, S. H.

    2014-11-01

    Recent experiments performed at the Matter in Extreme Conditions end station of the Linac Coherent Light Source (LCLS) have demonstrated the first spectrally resolved measurements of plasmons from isochorically heated aluminum. The experiments have been performed using a seeded 8-keV x-ray laser beam as a pump and probe to both volumetrically heat and scatter x-rays from aluminum. Collective x-ray Thomson scattering spectra show a well-resolved plasmon feature that is down-shifted in energy by 19 eV. In addition, Mbar shock pressures from laser-compressed aluminum foils using velocity interferometer system for any reflector have been measured. The combination of experiments fully demonstrates the possibility to perform warm dense matter studies at the LCLS with unprecedented accuracy and precision.

  10. Exploring Mbar shock conditions and isochorically heated aluminum at the Matter in Extreme Conditions end station of the Linac Coherent Light Source

    SciTech Connect

    Doppner, T.; LePape, S.; Ma, T.; Pak, A.; Turnbull, D.; Fletcher, L. B.; Lee, H. J.; Galtier, E.; Nagler, B.; Gauthier, M.; Heimann, P.; Hastings, J. B.; Zastrau, U.; Glenzer, S. H.; White, T.; Gregori, G.; Wei, M.; Barbrel, B.; Falcone, R. W.

    2014-08-11

    Recent experiments performed at the Matter in Extreme Conditions end station of the Linac Coherent Light Source (LCLS) have demonstrated the first spectrally resolved measurements of plasmons from isochorically heated aluminum. The experiments have been performed using a seeded 8-keV x-ray laser beam as a pump and probe to both volumetrically heat and scatterx-rays from aluminum. Collective x-ray Thomson scattering spectra show a well-resolved plasmon feature that is down-shifted in energy by 19 eV. In addition, Mbar shock pressures from laser-compressed aluminum foils using velocity interferometer system for any reflector have been measured. Furthermore, the combination of experiments fully demonstrates the possibility to perform warm dense matter studies at the LCLS with unprecedented accuracy and precision.