A Case-Only Study of Vulnerability to Heat Wave-Related Mortality in New York City (2000-2011).

Science.gov (United States)

Madrigano, Jaime; Ito, Kazuhiko; Johnson, Sarah; Kinney, Patrick L; Matte, Thomas

2015-07-01

As a result of climate change, the frequency of extreme temperature events is expected to increase, and such events are associated with increased morbidity and mortality. Vulnerability patterns, and corresponding adaptation strategies, are most usefully conceptualized at a local level. We used a case-only analysis to examine subject and neighborhood characteristics that modified the association between heat waves and mortality. All deaths of New York City residents from 2000 through 2011 were included in this analysis. Meteorological data were obtained from the National Climatic Data Center. Modifying characteristics were obtained from the death record and geographic data sets. A total of 234,042 adult deaths occurred during the warm season of our study period. Compared with other warm-season days, deaths during heat waves were more likely to occur in black (non-Hispanic) individuals than other race/ethnicities [odds ratio (OR) = 1.08; 95% CI: 1.03, 1.12], more likely to occur at home than in institutions and hospital settings (OR = 1.11; 95% CI: 1.06, 1.16), and more likely among those living in census tracts that received greater public assistance (OR = 1.05; 95% CI: 1.01, 1.09). Finally, deaths during heat waves were more likely among residents in areas of the city with higher relative daytime summer surface temperature and less likely among residents living in areas with more green space. Mortality during heat waves varies widely within a city. Understanding which individuals and neighborhoods are most vulnerable can help guide local preparedness efforts.

Changes in cause-specific mortality during heat waves in central Spain, 1975-2008

Science.gov (United States)

Miron, Isidro Juan; Linares, Cristina; Montero, Juan Carlos; Criado-Alvarez, Juan Jose; Díaz, Julio

2015-09-01

The relationship between heat waves and mortality has been widely described, but there are few studies using long daily data on specific-cause mortality. This study is undertaken in central Spain and analysing natural causes, circulatory and respiratory causes of mortality from 1975 to 2008. Time-series analysis was performed using ARIMA models, including data on specific-cause mortality and maximum and mean daily temperature and mean daily air pressure. The length of heat waves and their chronological number were analysed. Data were stratified in three decadal stages: 1975-1985, 1986-1996 and 1997-2008. Heat-related mortality was triggered by a threshold temperature of 37 °C. For each degree that the daily maximum temperature exceeded 37 °C, the percentage increase in mortality due to circulatory causes was 19.3 % (17.3-21.3) in 1975-1985, 30.3 % (28.3-32.3) in 1986-1996 and 7.3 % (6.2-8.4) in 1997-2008. The increase in respiratory cause ranged from 12.4 % (7.8-17.0) in the first period, to 16.3 % (14.1-18.4) in the second and 13.7 % (11.5-15.9) in the last. Each day of heat-wave duration explained 5.3 % (2.6-8.0) increase in respiratory mortality in the first period and 2.3 % (1.6-3.0) in the last. Decadal scale differences exist for specific-causes mortality induced by extreme heat. The impact on heat-related mortality by natural and circulatory causes increases between the first and the second period and falls significantly in the last. For respiratory causes, the increase is no reduced in the last period. These results are of particular importance for the estimation of future impacts of climate change on health.

Impact of the 2011 heat wave on mortality and emergency department visits in Houston, Texas.

Science.gov (United States)

Zhang, Kai; Chen, Tsun-Hsuan; Begley, Charles E

2015-01-27

Heat waves have been linked to increased risk of mortality and morbidity, and are projected to increase in frequency and intensity in a changing climate. Houston and other areas in Texas experienced an exceptional heat wave in the summer of 2011 producing the hottest August on record. This study aims to assess the health-related impact of this heat wave. Distributed lag models were used to estimate associations between the 2011 heat wave and all-cause mortality and emergency department (ED) visits from May 1 through September 30 for the five-year period 2007-2011. The 2011 heat wave is defined as a continuous period from August 2 through 30, 2011 according to the heat advisories issued by the local National Weather Service office, and is included in the models as a dummy variable. We compared the estimated excess risk among the models with and without adjustment of continuous temperature and ozone. The 2011 heat wave in Houston was associated with a 3.6% excess risk in ED visits (95% CI: 0.6%, 6.6%) and 0.6% increase in mortality risk (95% CI: -5.5%, 7.1%). The elderly over 65 years of age were at the greatest risk in ED visits. These patterns are consistent across different heat-wave definitions, and results are similar when adjusting for continuous temperature and ozone. The 2011 heat wave in Houston had a substantial impact on ED visits and no significant impact on mortality. Our findings provide insights into local heat-wave and health preparations and interventions.

The impact of heat waves on mortality in 9 European cities: results from the EuroHEAT project.

Science.gov (United States)

D'Ippoliti, Daniela; Michelozzi, Paola; Marino, Claudia; de'Donato, Francesca; Menne, Bettina; Katsouyanni, Klea; Kirchmayer, Ursula; Analitis, Antonis; Medina-Ramón, Mercedes; Paldy, Anna; Atkinson, Richard; Kovats, Sari; Bisanti, Luigi; Schneider, Alexandra; Lefranc, Agnès; Iñiguez, Carmen; Perucci, Carlo A

2010-07-16

The present study aimed at developing a standardized heat wave definition to estimate and compare the impact on mortality by gender, age and death causes in Europe during summers 1990-2004 and 2003, separately, accounting for heat wave duration and intensity. Heat waves were defined considering both maximum apparent temperature and minimum temperature and classified by intensity, duration and timing during summer. The effect was estimated as percent increase in daily mortality during heat wave days compared to non heat wave days in people over 65 years. City specific and pooled estimates by gender, age and cause of death were calculated. The effect of heat waves showed great geographical heterogeneity among cities. Considering all years, except 2003, the increase in mortality during heat wave days ranged from + 7.6% in Munich to + 33.6% in Milan. The increase was up to 3-times greater during episodes of long duration and high intensity. Pooled results showed a greater impact in Mediterranean (+ 21.8% for total mortality) than in North Continental (+ 12.4%) cities. The highest effect was observed for respiratory diseases and among women aged 75-84 years. In 2003 the highest impact was observed in cities where heat wave episode was characterized by unusual meteorological conditions. Climate change scenarios indicate that extreme events are expected to increase in the future even in regions where heat waves are not frequent. Considering our results prevention programs should specifically target the elderly, women and those suffering from chronic respiratory disorders, thus reducing the impact on mortality.

The impact of heat waves on mortality in 9 European cities: results from the EuroHEAT project

Directory of Open Access Journals (Sweden)

Bisanti Luigi

2010-07-01

Full Text Available Abstract Background The present study aimed at developing a standardized heat wave definition to estimate and compare the impact on mortality by gender, age and death causes in Europe during summers 1990-2004 and 2003, separately, accounting for heat wave duration and intensity. Methods Heat waves were defined considering both maximum apparent temperature and minimum temperature and classified by intensity, duration and timing during summer. The effect was estimated as percent increase in daily mortality during heat wave days compared to non heat wave days in people over 65 years. City specific and pooled estimates by gender, age and cause of death were calculated. Results The effect of heat waves showed great geographical heterogeneity among cities. Considering all years, except 2003, the increase in mortality during heat wave days ranged from + 7.6% in Munich to + 33.6% in Milan. The increase was up to 3-times greater during episodes of long duration and high intensity. Pooled results showed a greater impact in Mediterranean (+ 21.8% for total mortality than in North Continental (+ 12.4% cities. The highest effect was observed for respiratory diseases and among women aged 75-84 years. In 2003 the highest impact was observed in cities where heat wave episode was characterized by unusual meteorological conditions. Conclusions Climate change scenarios indicate that extreme events are expected to increase in the future even in regions where heat waves are not frequent. Considering our results prevention programs should specifically target the elderly, women and those suffering from chronic respiratory disorders, thus reducing the impact on mortality.

Susceptibility to mortality related to temperature and heat and cold wave duration in the population of Stockholm County, Sweden

Directory of Open Access Journals (Sweden)

Joacim Rocklöv

2014-03-01

Full Text Available Background: Ambient temperatures can cause an increase in mortality. A better understanding is needed of how health status and other factors modify the risk associated with high and low temperatures, to improve the basis of preventive measures. Differences in susceptibility to temperature and to heat and cold wave duration are relatively unexplored. Objectives: We studied the associations between mortality and temperature and heat and cold wave duration, stratified by age and individual and medical factors. Methods: Deaths among all residents of Stockholm County between 1990 and 2002 were linked to discharge diagnosis data from hospital admissions, and associations were examined using the time stratified case-crossover design. Analyses were stratified by gender, age, pre-existing disease, country of origin, and municipality level wealth, and adjusted for potential confounding factors. Results: The effect on mortality by heat wave duration was higher for lower ages, in areas with lower wealth, for hospitalized patients younger than age 65. Odds were elevated among females younger than age 65, in groups with a previous hospital admission for mental disorders, and in persons with previous cardiovascular disease. Gradual increases in summer temperatures were associated with mortality in people older than 80 years, and with mortality in groups with a previous myocardial infarction and with chronic obstructive pulmonary disease (COPD in the population younger than 65 years. During winter, mortality was associated with a decrease in temperature particularly in men and with the duration of cold spells for the population older than 80. A history of hospitalization for myocardial infarction increased the odds associated with cold temperatures among the population older than 65. Previous mental disease or substance abuse increased the odds of death among the population younger than 65. Conclusion: To increase effectiveness, we suggest preventive efforts

Impacts of the 2015 Heat Waves on Mortality in the Czech Republic—A Comparison with Previous Heat Waves

Czech Academy of Sciences Publication Activity Database

Urban, Aleš; Hanzlíková, Hana; Kyselý, Jan; Plavcová, Eva

2017-01-01

Roč. 14, č. 12 (2017), č. článku 1562. ISSN 1660-4601 R&D Projects: GA ČR(CZ) GA16-22000S Grant - others:AV ČR(CZ) MSM100421604 Program:Program na podporu mezinárodní spolupráce začínajících výzkumných pracovníků Institutional support: RVO:68378289 Keywords : heat-related mortality * heat-wave * excess heat factor * Central Europe Subject RIV: DG - Athmosphere Sciences, Meteorology OBOR OECD: Climatic research Impact factor: 2.101, year: 2016 http://www.mdpi.com/1660-4601/14/12/1562

Mortality related to air pollution with the moscow heat wave and wildfire of 2010.

Science.gov (United States)

Shaposhnikov, Dmitry; Revich, Boris; Bellander, Tom; Bedada, Getahun Bero; Bottai, Matteo; Kharkova, Tatyana; Kvasha, Ekaterina; Lezina, Elena; Lind, Tomas; Semutnikova, Eugenia; Pershagen, Göran

2014-05-01

Prolonged high temperatures and air pollution from wildfires often occur together, and the two may interact in their effects on mortality. However, there are few data on such possible interactions. We analyzed day-to-day variations in the number of deaths in Moscow, Russia, in relation to air pollution levels and temperature during the disastrous heat wave and wildfire of 2010. Corresponding data for the period 2006-2009 were used for comparison. Daily average levels of PM10 and ozone were obtained from several continuous measurement stations. The daily number of nonaccidental deaths from specific causes was extracted from official records. Analyses of interactions considered the main effect of temperature as well as the added effect of prolonged high temperatures and the interaction with PM10. The major heat wave lasted for 44 days, with 24-hour average temperatures ranging from 24°C to 31°C and PM10 levels exceeding 300 μg/m on several days. There were close to 11,000 excess deaths from nonaccidental causes during this period, mainly among those older than 65 years. Increased risks also occurred in younger age groups. The most pronounced effects were for deaths from cardiovascular, respiratory, genitourinary, and nervous system diseases. Continuously increasing risks following prolonged high temperatures were apparent during the first 2 weeks of the heat wave. Interactions between high temperatures and air pollution from wildfires in excess of an additive effect contributed to more than 2000 deaths. Interactions between high temperatures and wildfire air pollution should be considered in risk assessments regarding health consequences of climate change.

Avoided heat-related mortality through climate adaptation strategies in three US cities.

Science.gov (United States)

Stone, Brian; Vargo, Jason; Liu, Peng; Habeeb, Dana; DeLucia, Anthony; Trail, Marcus; Hu, Yongtao; Russell, Armistead

2014-01-01

Heat-related mortality in US cities is expected to more than double by the mid-to-late 21st century. Rising heat exposure in cities is projected to result from: 1) climate forcings from changing global atmospheric composition; and 2) local land surface characteristics responsible for the urban heat island effect. The extent to which heat management strategies designed to lessen the urban heat island effect could offset future heat-related mortality remains unexplored in the literature. Using coupled global and regional climate models with a human health effects model, we estimate changes in the number of heat-related deaths in 2050 resulting from modifications to vegetative cover and surface albedo across three climatically and demographically diverse US metropolitan areas: Atlanta, Georgia, Philadelphia, Pennsylvania, and Phoenix, Arizona. Employing separate health impact functions for average warm season and heat wave conditions in 2050, we find combinations of vegetation and albedo enhancement to offset projected increases in heat-related mortality by 40 to 99% across the three metropolitan regions. These results demonstrate the potential for extensive land surface changes in cities to provide adaptive benefits to urban populations at risk for rising heat exposure with climate change.

Avoided heat-related mortality through climate adaptation strategies in three US cities.

Directory of Open Access Journals (Sweden)

Brian Stone

Full Text Available Heat-related mortality in US cities is expected to more than double by the mid-to-late 21st century. Rising heat exposure in cities is projected to result from: 1 climate forcings from changing global atmospheric composition; and 2 local land surface characteristics responsible for the urban heat island effect. The extent to which heat management strategies designed to lessen the urban heat island effect could offset future heat-related mortality remains unexplored in the literature. Using coupled global and regional climate models with a human health effects model, we estimate changes in the number of heat-related deaths in 2050 resulting from modifications to vegetative cover and surface albedo across three climatically and demographically diverse US metropolitan areas: Atlanta, Georgia, Philadelphia, Pennsylvania, and Phoenix, Arizona. Employing separate health impact functions for average warm season and heat wave conditions in 2050, we find combinations of vegetation and albedo enhancement to offset projected increases in heat-related mortality by 40 to 99% across the three metropolitan regions. These results demonstrate the potential for extensive land surface changes in cities to provide adaptive benefits to urban populations at risk for rising heat exposure with climate change.

The impact of heat waves and cold spells on mortality rates in the Dutch population

NARCIS (Netherlands)

Huynen, M. M.; Martens, P.; Schram, D.; Weijenberg, M. P.; Kunst, A. E.

2001-01-01

We conducted the study described in this paper to investigate the impact of ambient temperature on mortality in the Netherlands during 1979-1997, the impact of heat waves and cold spells on mortality in particular, and the possibility of any heat wave- or cold spell-induced forward displacement of

Differences on the effect of heat waves on mortality by sociodemographic and urban landscape characteristics.

Science.gov (United States)

Xu, Yihan; Dadvand, Payam; Barrera-Gómez, Jose; Sartini, Claudio; Marí-Dell'Olmo, Marc; Borrell, Carme; Medina-Ramón, Mercè; Sunyer, Jordi; Basagaña, Xavier

2013-06-01

Mortality increases during heat waves have been reported worldwide. The magnitude of these increases can vary within regions according to sociodemographic and urban landscape characteristics. The objectives of this study were to explore this variation and its determinants, and to identify the most heat-vulnerable areas by mapping heat vulnerability. We conducted a time-stratified case-crossover analysis using daily mortality in the Barcelona metropolitan area during the warm seasons of 1999-2006. Temperature data on the date of death were assigned to each individual, which were assigned to their census tract of residence. Eight census tract-level variables on socioeconomic or built environment characteristics were obtained from the census. Residence surrounding greenness was obtained from satellite data. The relative risk (RR) of mortality after three consecutive hot days (defined as those exceeding the 95th percentile of maximum temperature) was calculated via conditional logistic regression. Effect modification was examined by including interaction terms. Analyses were based on 52 806 deaths. The effect of three consecutive hot days was a 30% increase in all-cause mortality (RR=1.30, 95% CI 1.24 to 1.38). Heterogeneity of this effect was observed across census tracts. The effect of heat on mortality was higher in the census tracts with a large percentage of old buildings (RR=1.21, 95% CI 1.00 to 1.46), manual workers (RR=1.25, 95% CI 0.96 to 1.64) and residents perceiving little surrounding greenness (RR=1.29, 95% CI 1.01 to 1.65). After three consecutive hot days, mortality doubled in the most heat-vulnerable census tracts. Sociodemographic and urban landscape characteristics are associated to mortality risk during heat waves and are useful to build heat vulnerability maps.

Mortality during heat waves in South Korea, 1991 to 2005: How exceptional was the 1994 heat wave?

Czech Academy of Sciences Publication Activity Database

Kyselý, Jan; Kim, J.

2009-01-01

Roč. 38, č. 2 (2009), s. 105-116 ISSN 0936-577X R&D Projects: GA ČR GC205/07/J044 Institutional research plan: CEZ:AV0Z30420517 Keywords : heat wave * human mortality * East Asia * extreme events * climate change Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 2.250, year: 2009

Evaluating the Performance of a Climate-Driven Mortality Model during Heat Waves and Cold Spells in Europe

Science.gov (United States)

Lowe, Rachel; Ballester, Joan; Creswick, James; Robine, Jean-Marie; Herrmann, François R.; Rodó, Xavier

2015-01-01

The impact of climate change on human health is a serious concern. In particular, changes in the frequency and intensity of heat waves and cold spells are of high relevance in terms of mortality and morbidity. This demonstrates the urgent need for reliable early-warning systems to help authorities prepare and respond to emergency situations. In this study, we evaluate the performance of a climate-driven mortality model to provide probabilistic predictions of exceeding emergency mortality thresholds for heat wave and cold spell scenarios. Daily mortality data corresponding to 187 NUTS2 regions across 16 countries in Europe were obtained from 1998–2003. Data were aggregated to 54 larger regions in Europe, defined according to similarities in population structure and climate. Location-specific average mortality rates, at given temperature intervals over the time period, were modelled to account for the increased mortality observed during both high and low temperature extremes and differing comfort temperatures between regions. Model parameters were estimated in a Bayesian framework, in order to generate probabilistic simulations of mortality across Europe for time periods of interest. For the heat wave scenario (1–15 August 2003), the model was successfully able to anticipate the occurrence or non-occurrence of mortality rates exceeding the emergency threshold (75th percentile of the mortality distribution) for 89% of the 54 regions, given a probability decision threshold of 70%. For the cold spell scenario (1–15 January 2003), mortality events in 69% of the regions were correctly anticipated with a probability decision threshold of 70%. By using a more conservative decision threshold of 30%, this proportion increased to 87%. Overall, the model performed better for the heat wave scenario. By replacing observed temperature data in the model with forecast temperature, from state-of-the-art European forecasting systems, probabilistic mortality predictions could

Evaluating the Performance of a Climate-Driven Mortality Model during Heat Waves and Cold Spells in Europe

Directory of Open Access Journals (Sweden)

Rachel Lowe

2015-01-01

Full Text Available The impact of climate change on human health is a serious concern. In particular, changes in the frequency and intensity of heat waves and cold spells are of high relevance in terms of mortality and morbidity. This demonstrates the urgent need for reliable early-warning systems to help authorities prepare and respond to emergency situations. In this study, we evaluate the performance of a climate-driven mortality model to provide probabilistic predictions of exceeding emergency mortality thresholds for heat wave and cold spell scenarios. Daily mortality data corresponding to 187 NUTS2 regions across 16 countries in Europe were obtained from 1998–2003. Data were aggregated to 54 larger regions in Europe, defined according to similarities in population structure and climate. Location-specific average mortality rates, at given temperature intervals over the time period, were modelled to account for the increased mortality observed during both high and low temperature extremes and differing comfort temperatures between regions. Model parameters were estimated in a Bayesian framework, in order to generate probabilistic simulations of mortality across Europe for time periods of interest. For the heat wave scenario (1–15 August 2003, the model was successfully able to anticipate the occurrence or non-occurrence of mortality rates exceeding the emergency threshold (75th percentile of the mortality distribution for 89% of the 54 regions, given a probability decision threshold of 70%. For the cold spell scenario (1–15 January 2003, mortality events in 69% of the regions were correctly anticipated with a probability decision threshold of 70%. By using a more conservative decision threshold of 30%, this proportion increased to 87%. Overall, the model performed better for the heat wave scenario. By replacing observed temperature data in the model with forecast temperature, from state-of-the-art European forecasting systems, probabilistic mortality

Effect of heat waves on morbidity and mortality due to Parkinson's disease in Madrid: A time-series analysis.

Science.gov (United States)

Linares, Cristina; Martinez-Martin, Pablo; Rodríguez-Blázquez, Carmen; Forjaz, Maria João; Carmona, Rocío; Díaz, Julio

2016-01-01

Parkinson's disease (PD) is one of the factors which are associated with a higher risk of mortality during heat waves. The use of certain neuroleptic medications to control some of this disease's complications would appear to be related to an increase in heat-related mortality. To analyse the relationship and quantify the short-term effect of high temperatures during heat wave episodes in Madrid on daily mortality and PD-related hospital admissions. We used an ecological time-series study and fit Poisson regression models. We analysed the daily number of deaths due to PD and the number of daily PD-related emergency hospital admissions in the city of Madrid, using maximum daily temperature (°C) as the main environmental variable and chemical air pollution as covariates. We controlled for trend, seasonalities, and the autoregressive nature of the series. There was a maximum daily temperature of 30°C at which PD-related admissions were at a minimum. Similarly, a temperature of 34°C coincides with an increase in the number of admissions. For PD-related admissions, the Relative Risk (RR) for every increase of 1°C above the threshold temperature was 1.13 IC95%:(1.03-1.23) at lags 1 and 5; and for daily PD-related mortality, the RR was 1.14 IC95%:(1.01-1.28) at lag 3. Our results indicate that suffering from PD is a risk factor that contributes to the excess morbidity and mortality associated with high temperatures, and is relevant from the standpoint of public health prevention plans. Copyright © 2016 Elsevier Ltd. All rights reserved.

Mortality during a Large-Scale Heat Wave by Place, Demographic Group, Internal and External Causes of Death, and Building Climate Zone.

Science.gov (United States)

Joe, Lauren; Hoshiko, Sumi; Dobraca, Dina; Jackson, Rebecca; Smorodinsky, Svetlana; Smith, Daniel; Harnly, Martha

2016-03-09

Mortality increases during periods of elevated heat. Identification of vulnerable subgroups by demographics, causes of death, and geographic regions, including deaths occurring at home, is needed to inform public health prevention efforts. We calculated mortality relative risks (RRs) and excess deaths associated with a large-scale California heat wave in 2006, comparing deaths during the heat wave with reference days. For total (all-place) and at-home mortality, we examined risks by demographic factors, internal and external causes of death, and building climate zones. During the heat wave, 582 excess deaths occurred, a 5% increase over expected (RR = 1.05, 95% confidence interval (CI) 1.03-1.08). Sixty-six percent of excess deaths were at home (RR = 1.12, CI 1.07-1.16). Total mortality risk was higher among those aged 35-44 years than ≥ 65, and among Hispanics than whites. Deaths from external causes increased more sharply (RR = 1.18, CI 1.10-1.27) than from internal causes (RR = 1.04, CI 1.02-1.07). Geographically, risk varied by building climate zone; the highest risks of at-home death occurred in the northernmost coastal zone (RR = 1.58, CI 1.01-2.48) and the southernmost zone of California's Central Valley (RR = 1.43, CI 1.21-1.68). Heat wave mortality risk varied across subpopulations, and some patterns of vulnerability differed from those previously identified. Public health efforts should also address at-home mortality, non-elderly adults, external causes, and at-risk geographic regions.

Heat wave during the summer 2003: relationship between temperature, air pollution and mortality in nine French towns; Vague de chaleur de l'ete 2003: relations entre temperatures, pollution atmospherique et mortalite dans neuf villes francaises

Energy Technology Data Exchange (ETDEWEB)

NONE

2006-07-01

The objective of this study is to estimate, by taking the a particular period of summer 2003, the relationship between the exposure to ozone and the mortality risk. This estimation has for aim to realize a more valid, scientifically, evaluation of sanitary impact, for the period of heat wave that this one that could has been lead from anterior results. This study searches also to estimate, for the period of heat wave, the excess of mortality risk linked with the exposure to temperature and air pollution and the relative part of each of these factors in this combined effect. The analysis searches to evaluate an eventual displacement of mortality at short term that is to say a period of under mortality occurring at the immediate declining of the heat wave. (N.C.)

Raising Awareness on Heat Related Mortality in Bangladesh

Science.gov (United States)

Arrighi, J.; Burkart, K.; Nissan, H.

2017-12-01

Extreme heat is the leading cause of weather-related deaths in the United States and Europe, and was responsible for four of the ten deadliest natural disasters worldwide in 2015. Near the tropics, where hot weather is considered the norm, perceived heat risk is often low, but recent heat waves in South Asia have caught the attention of the health community, policy-makers and the public. In a recent collaboration between the Red Cross Red Crescent Climate Centre, Columbia University and BBC Media Action the effects of extreme heat in Bangladesh were analyzed and the findings were subsequently used as a basis to raise awareness about the impacts of extreme heat on the most vulnerable, to the general public. Analysis of excess heat in Bangladesh between 2003 and 2007 showed that heatwaves occur between April and June with most extreme heat events occurring in May. Between 2003 and 2007 it is estimated that an average of 1500 people died per year due to heatwaves lasting three days or longer, with an eight-day heatwave in 2005 resulting in a minimum of 3,800 excess deaths. Utilizing these findings BBC Media Action launched an online communications campaign in May 2017 ultimately reaching approximately 3.9 million people with information on reducing the impacts of extreme heat. This presentation will highlight key findings from the study of heat related mortality in Bangladesh as well as highlight the benefit of collaboration between scientists and communicators for increasing awareness about the effects of extreme heat on the most vulnerable.

The application of the European heat wave of 2003 to Korean cities to analyze impacts on heat-related mortality

Science.gov (United States)

Greene, J. Scott; Kalkstein, Laurence S.; Kim, Kyu Rang; Choi, Young-Jean; Lee, Dae-Geun

2016-02-01

The goal of this research is to transpose the unprecedented 2003 European excessive heat event to six Korean cities and to develop meteorological analogs for each. Since this heat episode is not a model but an actual event, we can use a plausible analog to assess the risk of increasing heat on these cities instead of an analog that is dependent on general circulation (GCM) modeling or the development of arbitrary scenarios. Initially, the 2003 summer meteorological conditions from Paris are characterized statistically and these characteristics are transferred to the Korean cites. Next, the new meteorological dataset for each Korean city is converted into a daily air mass calendar. We can then determine the frequency and character of "offensive" air masses in the Korean cities that are historically associated with elevated heat-related mortality. One unexpected result is the comparative severity of the very hot summer of 1994 in Korea, which actually eclipsed the 2003 analog. The persistence of the offensive air masses is considerably greater for the summer of 1994, as were dew point temperatures for a majority of the Korean cities. For all the Korean cities but one, the summer of 1994 is associated with more heat-related deaths than the analog summer, in some cases yielding a sixfold increase over deaths in an average summer. The Korean cities appear less sensitive to heat-related mortality problems during very hot summers than do large eastern and Midwestern US cities, possibly due to a lesser summer climate variation and efficient social services available during extreme heat episodes.

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

Science.gov (United States)

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

The impact of heat waves on children's health: a systematic review

Science.gov (United States)

Xu, Zhiwei; Sheffield, Perry E.; Su, Hong; Wang, Xiaoyu; Bi, Yan; Tong, Shilu

2014-03-01

Young children are thought to be particularly sensitive to heat waves, but relatively less research attention has been paid to this field to date. A systematic review was conducted to elucidate the relationship between heat waves and children's health. Literature published up to August 2012 were identified using the following MeSH terms and keywords: "heatwave", "heat wave", "child health", "morbidity", "hospital admission", "emergency department visit", "family practice", "primary health care", "death" and "mortality". Of the 628 publications identified, 12 met the selection criteria. The existing literature does not consistently suggest that mortality among children increases significantly during heat waves, even though infants were associated with more heat-related deaths. Exposure to heat waves in the perinatal period may pose a threat to children's health. Pediatric diseases or conditions associated with heat waves include renal disease, respiratory disease, electrolyte imbalance and fever. Future research should focus on how to develop a consistent definition of a heat wave from a children's health perspective, identifying the best measure of children's exposure to heat waves, exploring sensitive outcome measures to quantify the impact of heat waves on children, evaluating the possible impacts of heat waves on children's birth outcomes, and understanding the differences in vulnerability to heat waves among children of different ages and from different income countries. Projection of the children's disease burden caused by heat waves under climate change scenarios, and development of effective heat wave mitigation and adaptation strategies that incorporate other child protective health measures, are also strongly recommended.

A spatial analysis of heat stress related emergency room visits in rural Southern Ontario during heat waves.

Science.gov (United States)

Bishop-Williams, Katherine E; Berke, Olaf; Pearl, David L; Kelton, David F

2015-08-06

In Southern Ontario, climate change may have given rise to an increasing occurrence of heat waves since the year 2000, which can cause heat stress to the general public, and potentially have detrimental health consequences. Heat waves are defined as three consecutive days with temperatures of 32 °C and above. Heat stress is the level of discomfort. A variety of heat stress indices have been proposed to measure heat stress (e.g., the heat stress index (HSI)), and has been shown to predict increases in morbidity and/or mortality rates in humans and other species. Maps visualizing the distribution of heat stress can provide information about related health risks and insight for control strategies. Information to inform heat wave preparedness models in Ontario was previously only available for major metropolitan areas. Hospitals in communities of fewer than 100,000 individuals were recruited for a pilot study by telephone. The number of people visiting the emergency room or 24-hour urgent care service was collected for a total of 27 days, covering three heat waves and six 3-day control periods from 2010-2012. The heat stress index was spatially predicted using data from 37 weather stations across Southern Ontario by geostatistical kriging. Poisson regression modeling was applied to determine the rate of increased number of emergency room visits in rural hospitals with respect to the HSI. During a heat wave, the average rate of emergency room visits was 1.11 times higher than during a control period (IRR = 1.11, CI95% (IRR) = (1.07,1.15), p ≤ 0.001). In a univariable model, HSI was not a significant predictor of emergency room visits, but when accounting for the confounding effect of a spatial trend polynomial in the hospital location coordinates, a one unit increase in HSI predicted an increase in daily emergency rooms visits by 0.4% (IRR = 1.004, CI95%(IRR) = (1.0005,1.007), p = 0.024) across the region. One high-risk cluster and no low risk

Urbanization Level and Vulnerability to Heat-Related Mortality in Jiangsu Province, China.

Science.gov (United States)

Chen, Kai; Zhou, Lian; Chen, Xiaodong; Ma, Zongwei; Liu, Yang; Huang, Lei; Bi, Jun; Kinney, Patrick L

2016-12-01

Although adverse effects of high temperature on mortality have been studied extensively in urban areas, little is known of the heat-mortality associations outside of cities. We investigated whether heat-mortality associations differed between urban and nonurban areas and how urbanicity affected the vulnerability to heat-related mortality. We first analyzed heat-related mortality risk in each of 102 counties in Jiangsu Province, China, during 2009-2013 using a distributed-lag nonlinear model. The county-specific estimates were then pooled for more urban (percentage of urban population ≥ 57.11%) and less urban (percentage of urban population risk comparing the 99th vs. 75th percentiles of temperature was 1.43 [95% posterior intervals (PI): 1.36, 1.50] in less urban counties and 1.26 (95% PI: 1.23, 1.30) in more urban counties. The heat effects on cardiorespiratory mortality followed a similar pattern. Higher education level and prevalence of air conditioning were significantly associated with counties having lower risks, whereas percentage of elderly people was significantly associated with increased risks. Our findings reveal that nonurban areas have significant heat-related mortality risks in Jiangsu, China. These results suggest the need for enhanced adaptation planning in Chinese nonurban areas under a changing climate. Citation: Chen K, Zhou L, Chen X, Ma Z, Liu Y, Huang L, Bi J, Kinney PL. 2016. Urbanization level and vulnerability to heat-related mortality in Jiangsu Province, China. Environ Health Perspect 124:1863-1869; http://dx.doi.org/10.1289/EHP204.

Impact of climate change on heat-related mortality in Jiangsu Province, China.

Science.gov (United States)

Chen, Kai; Horton, Radley M; Bader, Daniel A; Lesk, Corey; Jiang, Leiwen; Jones, Bryan; Zhou, Lian; Chen, Xiaodong; Bi, Jun; Kinney, Patrick L

2017-05-01

A warming climate is anticipated to increase the future heat-related total mortality in urban areas. However, little evidence has been reported for cause-specific mortality or nonurban areas. Here we assessed the impact of climate change on heat-related total and cause-specific mortality in both urban and rural counties of Jiangsu Province, China, in the next five decades. To address the potential uncertainty in projecting future heat-related mortality, we applied localized urban- and nonurban-specific exposure response functions, six population projections including a no population change scenario and five Shared Socioeconomic Pathways (SSPs), and 42 temperature projections from 21 global-scale general circulation models and two Representative Concentration Pathways (RCPs). Results showed that projected warmer temperatures in 2016-2040 and 2041-2065 will lead to higher heat-related mortality for total non-accidental, cardiovascular, respiratory, stroke, ischemic heart disease (IHD), and chronic obstructive pulmonary disease (COPD) causes occurring annually during May to September in Jiangsu Province, China. Nonurban residents in Jiangsu will suffer from more excess heat-related cause-specific mortality in 2016-2065 than urban residents. Variations across climate models and RCPs dominated the uncertainty of heat-related mortality estimation whereas population size change only had limited influence. Our findings suggest that targeted climate change mitigation and adaptation measures should be taken in both urban and nonurban areas of Jiangsu Province. Specific public health interventions should be focused on the leading causes of death (stroke, IHD, and COPD), whose health burden will be amplified by a warming climate. Copyright © 2017 Elsevier Ltd. All rights reserved.

Impact of Climate Change on Heat-Related Mortality in Jiangsu Province, China

Science.gov (United States)

Chen, Kai; Horton, Radley M.; Bader, Daniel A.; Lesk, Corey; Jiang, Leiwen; Jones, Bryan; Zhou, Lian; Chen, Xiaodong; Bi, Jun; Kinney, Patrick L.

2017-01-01

A warming climate is anticipated to increase the future heat-related total mortality in urban areas. However, little evidence has been reported for cause-specific mortality or nonurban areas. Here we assessed the impact of climate change on heat-related total and cause-specific mortality in both urban and rural counties of Jiangsu Province, China, in the next five decades. To address the potential uncertainty in projecting future heat-related mortality, we applied localized urban- and nonurban-specific exposure response functions, six population projections including a no population change scenario and five Shared Socioeconomic Pathways (SSPs), and 42 temperature projections from 21 global-scale general circulation models and two Representative Concentration Pathways (RCPs). Results showed that projected warmer temperatures in 2016-2040 and 2041-2065 will lead to higher heat-related mortality for total non-accidental, cardiovascular, respiratory, stroke, ischemic heart disease (IHD), and chronic obstructive pulmonary disease (COPD) causes occurring annually during May to September in Jiangsu Province, China. Nonurban residents in Jiangsu will suffer from more excess heat-related cause-specific mortality in 2016-2065 than urban residents. Variations across climate models and RCPs dominated the uncertainty of heat-related mortality estimation whereas population size change only had limited influence. Our findings suggest that targeted climate change mitigation and adaptation measures should be taken in both urban and nonurban areas of Jiangsu Province. Specific public health interventions should be focused on the leading causes of death (stroke, IHD, and COPD), whose health burden will be amplified by a warming climate.

The urban heat island and its impact on heat waves and human health in Shanghai.

Science.gov (United States)

Tan, Jianguo; Zheng, Youfei; Tang, Xu; Guo, Changyi; Li, Liping; Song, Guixiang; Zhen, Xinrong; Yuan, Dong; Kalkstein, Adam J; Li, Furong

2010-01-01

With global warming forecast to continue into the foreseeable future, heat waves are very likely to increase in both frequency and intensity. In urban regions, these future heat waves will be exacerbated by the urban heat island effect, and will have the potential to negatively influence the health and welfare of urban residents. In order to investigate the health effects of the urban heat island (UHI) in Shanghai, China, 30 years of meteorological records (1975-2004) were examined for 11 first- and second-order weather stations in and around Shanghai. Additionally, automatic weather observation data recorded in recent years as well as daily all-cause summer mortality counts in 11 urban, suburban, and exurban regions (1998-2004) in Shanghai have been used. The results show that different sites (city center or surroundings) have experienced different degrees of warming as a result of increasing urbanization. In turn, this has resulted in a more extensive urban heat island effect, causing additional hot days and heat waves in urban regions compared to rural locales. An examination of summer mortality rates in and around Shanghai yields heightened heat-related mortality in urban regions, and we conclude that the UHI is directly responsible, acting to worsen the adverse health effects from exposure to extreme thermal conditions.

Health impacts of the July 2010 heat wave in Québec, Canada.

Science.gov (United States)

Bustinza, Ray; Lebel, Germain; Gosselin, Pierre; Bélanger, Diane; Chebana, Fateh

2013-01-21

One of the consequences of climate change is the increased frequency and intensity of heat waves which can cause serious health impacts. In Québec, July 2010 was marked by an unprecedented heat wave in recent history. The purpose of this study is to estimate certain health impacts of this heat wave. The crude daily death and emergency department admission rates during the heat wave were analyzed in relation to comparison periods using 95% confidence intervals. During the heat wave, the crude daily rates showed a significant increase of 33% for deaths and 4% for emergency department admissions in relation to comparison periods. No displacement of mortality was observed over a 60-day horizon. The all-cause death indicator seems to be sufficiently sensitive and specific for surveillance of exceedences of critical temperature thresholds, which makes it useful for a heat health-watch system. Many public health actions combined with the increased use of air conditioning in recent decades have contributed to a marked reduction in mortality during heat waves. However, an important residual risk remains, which needs to be more vigorously addressed by public health authorities in light of the expected increase in the frequency and severity of heat waves and the aging of the population.

Differences in Heat-Related Mortality by Citizenship Status: United States, 2005-2014.

Science.gov (United States)

Taylor, Ethel V; Vaidyanathan, Ambarish; Flanders, W Dana; Murphy, Matthew; Spencer, Merianne; Noe, Rebecca S

2018-04-01

To determine whether non-US citizens have a higher mortality risk of heat-related deaths than do US citizens. We used place of residence reported in mortality data from the National Vital Statistics System from 2005 to 2014 as a proxy for citizenship to examine differences in heat-related deaths between non-US and US citizens. Estimates from the US Census Bureau American Community Survey of self-reported citizenship status and place of birth provided the numbers for the study population. We calculated the standardized mortality ratio and relative risk for heat-related deaths between non-US and US citizens nationally. Heat-related deaths accounted for 2.23% (n = 999) of deaths among non-US citizens and 0.02% (n = 4196) of deaths among US citizens. The age-adjusted standardized mortality ratio for non-US citizens compared with US citizens was 3.4 (95% confidence ratio [CI] = 3.2, 3.6). This risk was higher for Hispanic non-US citizens (risk ratio [RR] = 3.6; 95% CI = 3.2, 3.9) and non-US citizens aged 18 to 24 years (RR = 20.6; 95% CI = 16.5, 25.7). We found an increased mortality risk among non-US citizens compared with US citizens for heat-related deaths, especially those younger and of Hispanic ethnicity.

Health impacts of the July 2010 heat wave in Québec, Canada

Directory of Open Access Journals (Sweden)

Bustinza Ray

2013-01-01

Full Text Available Abstract Background One of the consequences of climate change is the increased frequency and intensity of heat waves which can cause serious health impacts. In Québec, July 2010 was marked by an unprecedented heat wave in recent history. The purpose of this study is to estimate certain health impacts of this heat wave. Methods The crude daily death and emergency department admission rates during the heat wave were analyzed in relation to comparison periods using 95% confidence intervals. Results During the heat wave, the crude daily rates showed a significant increase of 33% for deaths and 4% for emergency department admissions in relation to comparison periods. No displacement of mortality was observed over a 60-day horizon. Conclusions The all-cause death indicator seems to be sufficiently sensitive and specific for surveillance of exceedences of critical temperature thresholds, which makes it useful for a heat health-watch system. Many public health actions combined with the increased use of air conditioning in recent decades have contributed to a marked reduction in mortality during heat waves. However, an important residual risk remains, which needs to be more vigorously addressed by public health authorities in light of the expected increase in the frequency and severity of heat waves and the aging of the population.

Mortality displacement as a function of heat event strength in 7 US cities.

Science.gov (United States)

Saha, Michael V; Davis, Robert E; Hondula, David M

2014-02-15

Mortality rates increase immediately after periods of high air temperature. In the days and weeks after heat events, time series may exhibit mortality displacement-periods of lower than expected mortality. We examined all-cause mortality and meteorological data from 1980 to 2009 in the cities of Atlanta, Georgia; Boston, Massachusetts; Minneapolis-St. Paul, Minnesota; Philadelphia, Pennsylvania; Phoenix, Arizona; Seattle, Washington; and St. Louis, Missouri. We modeled baseline mortality using a generalized additive model. Heat waves were defined as periods of 3 or more consecutive days in which the apparent temperature exceeded a variable percentile. For each heat wave, we calculated the sum of excess and deficit mortality. Mortality displacement, which is the ratio of grand sum deficit to grand sum excess mortality, decreased as a function of event strength in all cities. Displacement was close to 1.00 for the weakest events. At the highest temperatures, displacement varied from 0.35 (95% confidence interval: 0.21, 0.55) to 0.75 (95% confidence interval: 0.54, 0.97). We found strong evidence of acclimatization across cities. Without consideration of displacement effects, the net impacts of heat-wave mortality are likely to be significant overestimations. A statistically significant positive relationship between the onset temperature of nondisplaced heat mortality and mean warm-season temperature (R(2) = 0.78, P < 0.01) suggests that heat mortality thresholds may be predictable across cities.

Public crowdsensing of heat waves by social media data

Science.gov (United States)

Grasso, Valentina; Crisci, Alfonso; Morabito, Marco; Nesi, Paolo; Pantaleo, Gianni

2017-07-01

Investigating on society-related heat wave hazards is a global issue concerning the people health. In the last two decades, Europe experienced several severe heat wave episodes with catastrophic effects in term of human mortality (2003, 2010 and 2015). Recent climate investigations confirm that this threat will represent a key issue for the resiliency of urban communities in next decades. Several important mitigation actions (Heat-Health Action Plans) against heat hazards have been already implemented in some WHO (World Health Organization) European region member states to encourage preparedness and response to extreme heat events. Nowadays, social media (SM) offer new opportunities to indirectly measure the impact of heat waves on society. Using the crowdsensing concept, a micro-blogging platform like Twitter may be used as a distributed network of mobile sensors that react to external events by exchanging messages (tweets). This work presents a preliminary analysis of tweets related to heat waves that occurred in Italy in summer 2015. Using TwitterVigilance dashboard, developed by the University of Florence, a sample of tweets related to heat conditions was retrieved, stored and analyzed for main features. Significant associations between the daily increase in tweets and extreme temperatures were presented. The daily volume of Twitter users and messages revealed to be a valuable indicator of heat wave impact at the local level, in urban areas. Furthermore, with the help of Generalized Additive Model (GAM), the volume of tweets in certain locations has been used to estimate thresholds of local discomfort conditions. These city-specific thresholds are the result of dissimilar climatic conditions and risk cultures.

Heat stress mortality and desired adaptation responses of healthcare system in Poland

Science.gov (United States)

Błażejczyk, Anna; Błażejczyk, Krzysztof; Baranowski, Jarosław; Kuchcik, Magdalena

2018-03-01

Heat stress is one of the environmental factors influencing the health of individuals and the wider population. There is a large body of research to document significant increases in mortality and morbidity during heat waves all over the world. This paper presents key results of research dealing with heat-related mortality (HRM) in various cities in Poland which cover about 25% of the country's population. Daily mortality and weather data reports for the years 1991-2000 were used. The intensity of heat stress was assessed by the universal thermal climate index (UTCI). The research considers also the projections of future bioclimate to the end of twenty-first century. Brain storming discussions were applied to find necessary adaptation strategies of healthcare system (HCS) in Poland, to minimise negative effects of heat stress. In general, in days with strong and very strong heat stress, ones must expect increase in mortality (in relation to no thermal stress days) of 12 and 47%, respectively. Because of projected rise in global temperature and heat stress frequency, we must expect significant increase in HRM to the end of twenty-first century of even 165% in comparison to present days. The results of research show necessity of urgent implementation of adaptation strategies to heat in HCS.

Geographical differences on the mortality impact of heat waves in Europe

Directory of Open Access Journals (Sweden)

Sunyer Jordi

2010-07-01

Full Text Available Abstract Climate change is potentially the biggest global health threat in the 21st century. Deaths related with heat waves and spread of infectious diseases will be part of the menace though the major impact will be caused by malnutrition, diarrhea and extreme climate events. Consequently, loss of healthy life years as a result of global climate change is predicted to be 500 times greater in poor African populations than in European populations. However, the increase of more than 2°C of average temperature will result in a negative health impact in all regions, the potential benefits of a warmer temperature being negatively compensated, heat waves being one of the largest climate change threats in the developed world.

Temporal Compounding of Heat Waves in the Present and Projected Future

Science.gov (United States)

Baldwin, J. W.; Dessy, J.; Vecchi, G. A.; Oppenheimer, M.

2017-12-01

The hazard of heat waves is projected to increase significantly with global warming, motivating much recent research characterizing various aspects of these extreme events. One less examined aspect of heat waves is their temporal structure. Here we first modify existing heat wave duration definitions to flexibly account for a variety of possible heat wave temporal structures (sequences of hot and cooler days). We then examine past heat waves associated with high mortality using observational reanalysis data, and note that many past heat waves might be better described as series of hot days compounded together with short breaks of cooler days in between. We employ Geophysical Fluid Dynamics Laboratory (GFDL) global climate model (GCM) simulations to compare the frequency of these compound heat waves in the present and projected future with higher levels of atmospheric carbon dioxide. Our results indicate that temporally compound heatwaves will constitute a greater proportion of heat wave risk with global warming. Via examining synthetic autoregressive model data, we propose that this phenomenon is expected when shifting the mean of a time series with some memory and noise. Notably, an increased proportion of compound events implies that vulnerability from prior hot days will play an increasingly large role in heat wave risk, with possible implications for both heat wave-related policy and preparedness.

Public crowdsensing of heat waves by social media data

Directory of Open Access Journals (Sweden)

V. Grasso

2017-07-01

Full Text Available Investigating on society-related heat wave hazards is a global issue concerning the people health. In the last two decades, Europe experienced several severe heat wave episodes with catastrophic effects in term of human mortality (2003, 2010 and 2015. Recent climate investigations confirm that this threat will represent a key issue for the resiliency of urban communities in next decades. Several important mitigation actions (Heat-Health Action Plans against heat hazards have been already implemented in some WHO (World Health Organization European region member states to encourage preparedness and response to extreme heat events. Nowadays, social media (SM offer new opportunities to indirectly measure the impact of heat waves on society. Using the crowdsensing concept, a micro-blogging platform like Twitter may be used as a distributed network of mobile sensors that react to external events by exchanging messages (tweets. This work presents a preliminary analysis of tweets related to heat waves that occurred in Italy in summer 2015. Using TwitterVigilance dashboard, developed by the University of Florence, a sample of tweets related to heat conditions was retrieved, stored and analyzed for main features. Significant associations between the daily increase in tweets and extreme temperatures were presented. The daily volume of Twitter users and messages revealed to be a valuable indicator of heat wave impact at the local level, in urban areas. Furthermore, with the help of Generalized Additive Model (GAM, the volume of tweets in certain locations has been used to estimate thresholds of local discomfort conditions. These city-specific thresholds are the result of dissimilar climatic conditions and risk cultures.

Temperature and Heat-Related Mortality Trends in the Sonoran and Mojave Desert Region

Directory of Open Access Journals (Sweden)

Polioptro F. Martinez-Austria

2017-03-01

Full Text Available Extreme temperatures and heat wave trends in five cities within the Sonoran Desert region (e.g., Tucson and Phoenix, Arizona, in the United States and Ciudad Obregon and San Luis Rio Colorado, Sonora; and Mexicali, Baja California, in Mexico and one city within the Mojave Desert region (e.g., Las Vegas, Nevada were assessed using field data collected from 1950 to 2014. Instead of being selected by watershed, the cities were selected because they are part of the same arid climatic region. The data were analyzed for maximum temperature increases and the trends were confirmed statistically using Spearman’s nonparametric test. Temperature trends were correlated with the mortality information related with extreme heat events in the region. The results showed a clear trend of increasing maximum temperatures during the months of June, July, and August for five of the six cities and statically confirmed using Spearman’s rho values. Las Vegas was the only city where the temperature increase was not confirmed using Spearman’s test, probably because it is geographically located outside of the Sonoran Desert or because of its proximity to the Hoover Dam. The relationship between mortality and temperature was analyzed for the cities of Mexicali, Mexico and Phoenix. Arizona.

Temperature Observation Time and Type Influence Estimates of Heat-Related Mortality in Seven U.S. Cities.

Science.gov (United States)

Davis, Robert E; Hondula, David M; Patel, Anjali P

2016-06-01

Extreme heat is a leading weather-related cause of mortality in the United States, but little guidance is available regarding how temperature variable selection impacts heat-mortality relationships. We examined how the strength of the relationship between daily heat-related mortality and temperature varies as a function of temperature observation time, lag, and calculation method. Long time series of daily mortality counts and hourly temperature for seven U.S. cities with different climates were examined using a generalized additive model. The temperature effect was modeled separately for each hour of the day (with up to 3-day lags) along with different methods of calculating daily maximum, minimum, and mean temperature. We estimated the temperature effect on mortality for each variable by comparing the 99th versus 85th temperature percentiles, as determined from the annual time series. In three northern cities (Boston, MA; Philadelphia, PA; and Seattle, WA) that appeared to have the greatest sensitivity to heat, hourly estimates were consistent with a diurnal pattern in the heat-mortality response, with strongest associations for afternoon or maximum temperature at lag 0 (day of death) or afternoon and evening of lag 1 (day before death). In warmer, southern cities, stronger associations were found with morning temperatures, but overall the relationships were weaker. The strongest temperature-mortality relationships were associated with maximum temperature, although mean temperature results were comparable. There were systematic and substantial differences in the association between temperature and mortality based on the time and type of temperature observation. Because the strongest hourly temperature-mortality relationships were not always found at times typically associated with daily maximum temperatures, temperature variables should be selected independently for each study location. In general, heat-mortality was more closely coupled to afternoon and maximum

Characterizing prolonged heat effects on mortality in a sub-tropical high-density city, Hong Kong

Science.gov (United States)

Ho, Hung Chak; Lau, Kevin Ka-Lun; Ren, Chao; Ng, Edward

2017-11-01

Extreme hot weather events are likely to increase under future climate change, and it is exacerbated in urban areas due to the complex urban settings. It causes excess mortality due to prolonged exposure to such extreme heat. However, there is lack of universal definition of prolonged heat or heat wave, which leads to inadequacies of associated risk preparedness. Previous studies focused on estimating temperature-mortality relationship based on temperature thresholds for assessing heat-related health risks but only several studies investigated the association between types of prolonged heat and excess mortality. However, most studies focused on one or a few isolated heat waves, which cannot demonstrate typical scenarios that population has experienced. In addition, there are limited studies on the difference between daytime and nighttime temperature, resulting in insufficiency to conclude the effect of prolonged heat. In sub-tropical high-density cities where prolonged heat is common in summer, it is important to obtain a comprehensive understanding of prolonged heat for a complete assessment of heat-related health risks. In this study, six types of prolonged heat were examined by using a time-stratified analysis. We found that more consecutive hot nights contribute to higher mortality risk while the number of consecutive hot days does not have significant association with excess mortality. For a day after five consecutive hot nights, there were 7.99% [7.64%, 8.35%], 7.74% [6.93%, 8.55%], and 8.14% [7.38%, 8.88%] increases in all-cause, cardiovascular, and respiratory mortality, respectively. Non-consecutive hot days or nights are also found to contribute to short-term mortality risk. For a 7-day-period with at least five non-consecutive hot days and nights, there was 15.61% [14.52%, 16.70%] increase in all-cause mortality at lag 0-1, but only -2.00% [-2.83%, -1.17%] at lag 2-3. Differences in the temperature-mortality relationship caused by hot days and hot nights

Testing the time-scale dependence of delayed interactions: A heat wave during the egg stage shapes how a pesticide interacts with a successive heat wave in the larval stage.

Science.gov (United States)

Janssens, Lizanne; Tüzün, Nedim; Stoks, Robby

2017-11-01

Under global change organisms are exposed to multiple, potentially interacting stressors. Especially interactions between successive stressors are poorly understood and recently suggested to depend on their timing of exposure. We particularly need studies assessing the impact of exposure to relevant stressors at various life stages and how these interact. We investigated the single and combined impacts of a heat wave (mild [25 °C] and extreme [30 °C]) during the egg stage, followed by successive exposure to esfenvalerate (ESF) and a heat wave during the larval stage in damselflies. Each stressor caused mortality. The egg heat wave and larval ESF exposure had delayed effects on survival, growth and lipid peroxidation (MDA). This resulted in deviations from the prediction that stressors separated by a long time interval would not interact: the egg heat wave modulated the interaction between the stressors in the larval stage. Firstly, ESF caused delayed mortality only in larvae that had been exposed to the extreme egg heat wave and this strongly depended upon the larval heat wave treatment. Secondly, ESF only increased MDA in larvae not exposed to the egg heat wave. We found little support for the prediction that when there is limited time between stressors, synergistic interactions should occur. The intermediate ESF concentration only caused delayed mortality when combined with the larval heat wave, and the lowest ESF concentrations only increased oxidative damage when followed by the mild larval heat wave. Survival selection mitigated the interaction patterns between successive stressors that are individually lethal, and therefore should be included in a predictive framework for the time-scale dependence of the outcome of multistressor studies with pollutants. The egg heat wave shaping the interaction pattern between successive pesticide exposure and a larval heat wave highlights the connectivity between the concepts of 'heat-induced pesticide sensitivity' and

Social Interventions to Prevent Heat-Related Mortality in the Older Adult in Rome, Italy: A Quasi-Experimental Study

Science.gov (United States)

Inzerilli, Maria Chiara; Palombi, Leonardo; Madaro, Olga; Betti, Daniela; Marazzi, Maria Cristina

2018-01-01

This study focuses on the impact of a program aimed at reducing heat-related mortality among older adults residing in central Rome by counteracting social isolation. The mortality of citizens over the age of 75 living in three Urban Areas (UAs) located in central Rome is compared with that of the residents of four adjacent UAs during the summer of 2015. The data, broken down by UA, were provided by the Statistical Office of the Municipality of Rome, which gathers them on a routine basis. During the summer of 2015, 167 deaths were recorded in those UAs in which the Long Live the Elderly (LLE) program was active and 169 in those in which it was not, implying cumulative mortality rates of 25‰ (SD ± 1.4; Cl 95%: 23–29) and 29‰ (SD ± 6.7; Cl 95%: 17–43), respectively. Relative to the summer of 2014, the increase of deaths during the summer of 2015 was greater in UAs in which the LLE program had not been implemented (+97.3% vs. +48.8%). In conclusion, the paper shows the impact of a community-based active monitoring program, focused on strengthening individual relationship networks and the social capital of the community, on mortality in those over 75 during heat waves. PMID:29641436

The 2006 California heat wave: impacts on hospitalizations and emergency department visits.

Science.gov (United States)

Knowlton, Kim; Rotkin-Ellman, Miriam; King, Galatea; Margolis, Helene G; Smith, Daniel; Solomon, Gina; Trent, Roger; English, Paul

2009-01-01

Climate models project that heat waves will increase in frequency and severity. Despite many studies of mortality from heat waves, few studies have examined morbidity. In this study we investigated whether any age or race/ethnicity groups experienced increased hospitalizations and emergency department (ED) visits overall or for selected illnesses during the 2006 California heat wave. We aggregated county-level hospitalizations and ED visits for all causes and for 10 cause groups into six geographic regions of California. We calculated excess morbidity and rate ratios (RRs) during the heat wave (15 July to 1 August 2006) and compared these data with those of a reference period (8-14 July and 12-22 August 2006). During the heat wave, 16,166 excess ED visits and 1,182 excess hospitalizations occurred statewide. ED visits for heat-related causes increased across the state [RR = 6.30; 95% confidence interval (CI), 5.67-7.01], especially in the Central Coast region, which includes San Francisco. Children (0-4 years of age) and the elderly (> or = 65 years of age) were at greatest risk. ED visits also showed significant increases for acute renal failure, cardiovascular diseases, diabetes, electrolyte imbalance, and nephritis. We observed significantly elevated RRs for hospitalizations for heat-related illnesses (RR = 10.15; 95% CI, 7.79-13.43), acute renal failure, electrolyte imbalance, and nephritis. The 2006 California heat wave had a substantial effect on morbidity, including regions with relatively modest temperatures. This suggests that population acclimatization and adaptive capacity influenced risk. By better understanding these impacts and population vulnerabilities, local communities can improve heat wave preparedness to cope with a globally warming future.

An ecological time-series study of heat-related mortality in three European cities

Directory of Open Access Journals (Sweden)

Russo Antonio

2008-01-01

Full Text Available Abstract Background Europe has experienced warmer summers in the past two decades and there is a need to describe the determinants of heat-related mortality to better inform public health activities during hot weather. We investigated the effect of high temperatures on daily mortality in three cities in Europe (Budapest, London, and Milan, using a standard approach. Methods An ecological time-series study of daily mortality was conducted in three cities using Poisson generalized linear models allowing for over-dispersion. Secular trends in mortality and seasonal confounding factors were controlled for using cubic smoothing splines of time. Heat exposure was modelled using average values of the temperature measure on the same day as death (lag 0 and the day before (lag 1. The heat effect was quantified assuming a linear increase in risk above a cut-point for each city. Socio-economic status indicators and census data were linked with mortality data for stratified analyses. Results The risk of heat-related death increased with age, and females had a greater risk than males in age groups ≥65 years in London and Milan. The relative risks of mortality (per °C above the heat cut-point by gender and age were: (i Male 1.10 (95%CI: 1.07–1.12 and Female 1.07 (1.05–1.10 for 75–84 years, (ii M 1.10 (1.06–1.14 and F 1.08 (1.06–1.11 for ≥85 years in Budapest (≥24°C; (i M 1.03 (1.01–1.04 and F 1.07 (1.05–1.09, (ii M 1.05 (1.03–1.07 and F 1.08 (1.07–1.10 in London (≥20°C; and (i M 1.08 (1.03–1.14 and F 1.20 (1.15–1.26, (ii M 1.18 (1.11–1.26 and F 1.19 (1.15–1.24 in Milan (≥26°C. Mortality from external causes increases at higher temperatures as well as that from respiratory and cardiovascular disease. There was no clear evidence of effect modification by socio-economic status in either Budapest or London, but there was a seemingly higher risk for affluent non-elderly adults in Milan. Conclusion We found broadly consistent

The urban heat island dynamics during heat waves: a study of cities in the United States

Science.gov (United States)

Hu, Leiqiu

2016-04-01

The urban heat island (UHI) is a common phenomenon describing that metropolitan areas are usually warmer than their rural surroundings. This effect is compounded by extreme heat events, which are a leading cause of weather-related human mortality in many countries worldwide. However, the spatial and diurnal variability of temperature and humidity in urban and adjacent rural areas during extreme heat events is not well measured and therefore not well understood. The recently developed dataset of near-surface air and dew temperature from MODIS atmospheric profiles and the new method for the UHI quantification--urban heat island curve are used to quantify the urban climatic changes during heat waves in cities of the United States. The enhanced and weakened UHIs are observed in various cities. The causes of UHI changes during heat waves are discussed, including climate region, vegetation type and amount, city geolocation, etc.

Heat Wave Changes in the Eastern Mediterranean since 1960

Science.gov (United States)

Kuglitsch, Franz G.; Toreti, Andrea; Xoplaki, Elena; Della-Marta, Paul M.; Zerefos, Christos S.; Türkes, Murat; Luterbacher, Jürg

2010-05-01

Heat waves have discernible impacts on mortality and morbidity, infrastructure, agricultural resources, the retail industry, ecosystem and tourism and consequently affect human societies. A new definition of socially relevant heat waves is presented and applied to new data sets of high-quality homogenized daily maximum and minimum summer air temperature series from 246 stations in the eastern Mediterranean region (including Albania, Bosnia-Herzegovina, Bulgaria, Croatia, Cyprus, Greece, Israel, Romania, Serbia, Slovenia, Turkey). Changes in heat wave number, length and intensity between 1960 and 2006 are quantified. Daily temperature homogeneity analysis suggest that many instrumental measurements in the 1960s are warm-biased, correcting for these biases regionally averaged heat wave trends are up to 8% higher. We find significant changes across the western Balkans, southwestern and western Turkey, and along the southern Black Sea coastline. Since the 1960s, the mean heat wave intensity, heat wave length and heat wave number across the eastern Mediterranean region have increased by a factor 7.6 ±1.3, 7.5 ±1.3 and 6.2 ±1.1, respectively. These findings suggest that the heat wave increase in this region is higher than previously reported.

Urban Heat Wave Hazard Assessment

Science.gov (United States)

Quattrochi, D. A.; Jedlovec, G.; Crane, D. L.; Meyer, P. J.; LaFontaine, F.

2016-12-01

Heat waves are one of the largest causes of environmentally-related deaths globally and are likely to become more numerous as a result of climate change. The intensification of heat waves by the urban heat island effect and elevated humidity, combined with urban demographics, are key elements leading to these disasters. Better warning of the potential hazards may help lower risks associated with heat waves. Moderate resolution thermal data from NASA satellites is used to derive high spatial resolution estimates of apparent temperature (heat index) over urban regions. These data, combined with demographic data, are used to produce a daily heat hazard/risk map for selected cities. MODIS data are used to derive daily composite maximum and minimum land surface temperature (LST) fields to represent the amplitude of the diurnal temperature cycle and identify extreme heat days. Compositing routines are used to generate representative daily maximum and minimum LSTs for the urban environment. The limited effect of relative humidity on the apparent temperature (typically 10-15%) allows for the use of modeled moisture fields to convert LST to apparent temperature without loss of spatial variability. The daily max/min apparent temperature fields are used to identify abnormally extreme heat days relative to climatological values in order to produce a heat wave hazard map. Reference to climatological values normalizes the hazard for a particular region (e.g., the impact of an extreme heat day). A heat wave hazard map has been produced for several case study periods and then computed on a quasi-operational basis during the summer of 2016 for Atlanta, GA, Chicago, IL, St. Louis, MO, and Huntsville, AL. A hazard does not become a risk until someone or something is exposed to that hazard at a level that might do harm. Demographic information is used to assess the urban risk associated with the heat wave hazard. Collectively, the heat wave hazard product can warn people in urban

Estimating the Influence of Housing Energy Efficiency and Overheating Adaptations on Heat-Related Mortality in the West Midlands, UK

Directory of Open Access Journals (Sweden)

Jonathon Taylor

2018-05-01

Full Text Available Mortality rates rise during hot weather in England, and projected future increases in heatwave frequency and intensity require the development of heat protection measures such as the adaptation of housing to reduce indoor overheating. We apply a combined building physics and health model to dwellings in the West Midlands, UK, using an English Housing Survey (EHS-derived stock model. Regional temperature exposures, heat-related mortality risk, and space heating energy consumption were estimated for 2030s, 2050s, and 2080s medium emissions climates prior to and following heat mitigating, energy-efficiency, and occupant behaviour adaptations. Risk variation across adaptations, dwellings, and occupant types were assessed. Indoor temperatures were greatest in converted flats, while heat mortality rates were highest in bungalows due to the occupant age profiles. Full energy efficiency retrofit reduced regional domestic space heating energy use by 26% but increased summertime heat mortality 3–4%, while reduced façade absorptance decreased heat mortality 12–15% but increased energy consumption by 4%. External shutters provided the largest reduction in heat mortality (37–43%, while closed windows caused a large increase in risk (29–64%. Ensuring adequate post-retrofit ventilation, targeted installation of shutters, and ensuring operable windows in dwellings with heat-vulnerable occupants may save energy and significantly reduce heat-related mortality.

Projected heat-related mortality under climate change in the metropolitan area of Skopje

Directory of Open Access Journals (Sweden)

Gerardo Sanchez Martinez

2016-05-01

Full Text Available Abstract Background Excessive summer heat is a serious environmental health problem in Skopje, the capital and largest city of the former Yugoslav Republic of Macedonia. This paper attempts to forecast the impact of heat on mortality in Skopje in two future periods under climate change and compare it with a historical baseline period. Methods After ascertaining the relationship between daily mean ambient air temperature and daily mortality in Skopje, we modelled the evolution of ambient temperatures in the city under a Representative Concentration Pathway scenario (RCP8.5 and the evolution of the city population in two future time periods: 2026–2045 and 2081–2100, and in a past time period (1986–2005 to serve as baseline for comparison. We then calculated the projected average annual mortality attributable to heat in the absence of adaptation or acclimatization during those time windows, and evaluated the contribution of each source of uncertainty on the final impact. Results Our estimates suggest that, compared to the baseline period (1986–2005, heat-related mortality in Skopje would more than double in 2026–2045, and more than quadruple in 2081–2100. When considering the impact in 2081–2100, sampling variability around the heat–mortality relationship and climate model explained 40.3 and 46.6 % of total variability. Conclusion These results highlight the importance of a long-term perspective in the public health prevention of heat exposure, particularly in the context of a changing climate.

Summer heat and mortality in New York City: how hot is too hot?

Science.gov (United States)

Metzger, Kristina B; Ito, Kazuhiko; Matte, Thomas D

2010-01-01

To assess the public health risk of heat waves and to set criteria for alerts for -excessive heat, various meteorologic metrics and models are used in different jurisdictions, generally without systematic comparisons of alternatives. We report such an analysis for New York City that compared maximum heat index with alternative metrics in models to predict daily variation in warm-season natural-cause mortality from 1997 through 2006. We used Poisson time-series generalized linear models and generalized additive models to estimate weather-mortality relationships using various metrics, lag and averaging times, and functional forms and compared model fit. A model that included cubic functions of maximum heat index on the same and each of the previous 3 days provided the best fit, better than models using maximum, minimum, or average temperature, or spatial synoptic classification (SSC) of weather type. We found that goodness of fit and maximum heat index-mortality functions were similar using parametric and nonparametric models. Same-day maximum heat index was linearly related to mortality risk across its range. The slopes at lags of 1, 2, and 3 days were flat across moderate values but increased sharply between maximum heat index of 95 degrees F and 100 degrees F (35-38 degrees C). SSC or other meteorologic variables added to the maximum heat index model moderately improved goodness of fit, with slightly attenuated maximum heat index-mortality functions. In New York City, maximum heat index performed similarly to alternative and more complex metrics in estimating mortality risk during hot weather. The linear relationship supports issuing heat alerts in New York City when the heat index is forecast to exceed approximately 95-100 degrees F. Periodic city-specific analyses using recent data are recommended to evaluate public health risks from extreme heat.

Heat Waves

Science.gov (United States)

Heat Waves Dangers we face during periods of very high temperatures include: Heat cramps: These are muscular pains and spasms due ... that the body is having trouble with the heat. If a heat wave is predicted or happening… - ...

Urban Heat Wave Hazard Assessment

Science.gov (United States)

Quattrochi, Dale A.; Jedlovec, Gary; Meyer, Paul J.; LaFontaine, Frank J.; Crane, Dakota L.

2016-01-01

Heat waves are the largest cause of environment-related deaths globally. On average, over 6,000 people in the United States alone are hospitalized each summer due to excessive heat. Key elements leading to these disasters are elevated humidity and the urban heat island effect, which act together to increase apparent temperature and amplify the effects of a heat wave. Urban demographics and socioeconomic factors also play a role in determining individual risk. Currently, advisories of impending heat waves are often too generalized, with limited or no spatial variability over urban regions. This frequently contributes to a lack of specific response on behalf of the population. A goal of this project is to develop a product that has the potential to provide more specific heat wave guidance invoking greater awareness and action.

Defining and Predicting Heat Waves in Bangladesh

NARCIS (Netherlands)

Nissan, H.; Burkart, K.; Coughlan, E.R.; van Aalst, M.; Mason, S.

2017-01-01

This paper proposes a heat-wave definition for Bangladesh that could be used to trigger preparedness measures in a heat early warning system (HEWS) and explores the climate mechanisms associated with heat waves. A HEWSrequires a definition of heat waves that is both related to human health outcomes

Small-area spatiotemporal analysis of heatwave impacts on elderly mortality in Paris: A cluster analysis approach.

Science.gov (United States)

Benmarhnia, Tarik; Kihal-Talantikite, Wahida; Ragettli, Martina S; Deguen, Séverine

2017-08-15

Heat-waves have a substantial public health burden. Understanding spatial heterogeneity at a fine spatial scale in relation to heat and related mortality is central to target interventions towards vulnerable communities. To determine the spatial variability of heat-wave-related mortality risk among elderly in Paris, France at the census block level. We also aimed to assess area-level social and environmental determinants of high mortality risk within Paris. We used daily mortality data from 2004 to 2009 among people aged >65 at the French census block level within Paris. We used two heat wave days' definitions that were compared to non-heat wave days. A Bernoulli cluster analysis method was applied to identify high risk clusters of mortality during heat waves. We performed random effects meta-regression analyses to investigate factors associated with the magnitude of the mortality risk. The spatial approach revealed a spatial aggregation of death cases during heat wave days. We found that small scale chronic PM 10 exposure was associated with a 0.02 (95% CI: 0.001; 0.045) increase of the risk of dying during a heat wave episode. We also found a positive association with the percentage of foreigners and the percentage of labor force, while the proportion of elderly people living in the neighborhood was negatively associated. We also found that green space density had a protective effect and inversely that the density of constructed feature increased the risk of dying during a heat wave episode. We showed that a spatial variation in terms of heat-related vulnerability exists within Paris and that it can be explained by some contextual factors. This study can be useful for designing interventions targeting more vulnerable areas and reduce the burden of heat waves. Copyright © 2017 Elsevier B.V. All rights reserved.

Heat-related mortality projections for cardiovascular and respiratory disease under the changing climate in Beijing, China

Science.gov (United States)

Li, Tiantian; Ban, Jie; Horton, Radley M.; Bader, Daniel A.; Huang, Ganlin; Sun, Qinghua; Kinney, Patrick L.

2015-08-01

Because heat-related health effects tend to become more serious at higher temperatures, there is an urgent need to determine the mortality projection of specific heat-sensitive diseases to provide more detailed information regarding the variation of the sensitivity of such diseases. In this study, the specific mortality of cardiovascular and respiratory disease in Beijing was initially projected under five different global-scale General Circulation Models (GCMs) and two Representative Concentration Pathways scenarios (RCPs) in the 2020s, 2050s, and 2080s compared to the 1980s. Multi-model ensembles indicated cardiovascular mortality could increase by an average percentage of 18.4%, 47.8%, and 69.0% in the 2020s, 2050s, and 2080s under RCP 4.5, respectively, and by 16.6%,73.8% and 134% in different decades respectively, under RCP 8.5 compared to the baseline range. The same increasing pattern was also observed in respiratory mortality. The heat-related deaths under the RCP8.5 scenario were found to reach a higher number and to increase more rapidly during the 21st century compared to the RCP4.5 scenario, especially in the 2050s and the 2080s. The projection results show potential trends in cause-specific mortality in the context of climate change, and provide support for public health interventions tailored to specific climate-related future health risks.

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

Science.gov (United States)

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.

Towards More Comprehensive Projections of Urban Heat-Related Mortality: Estimates for New York City Under Multiple Population, Adaptation, and Climate Scenarios

Science.gov (United States)

Petkova, Elisaveta P.; Vink, Jan K.; Horton, Radley M.; Gasparrini, Antonio; Bader, Daniel A.; Francis, Joe D.; Kinney, Patrick L.

2016-01-01

High temperatures have substantial impacts on mortality and, with growing concerns about climate change, numerous studies have developed projections of future heat-related deaths around the world. Projections of temperature-related mortality are often limited by insufficient information necessary to formulate hypotheses about population sensitivity to high temperatures and future demographics. This study has derived projections of temperature-related mortality in New York City by taking into account future patterns of adaptation or demographic change, both of which can have profound influences on future health burdens. We adopt a novel approach to modeling heat adaptation by incorporating an analysis of the observed population response to heat in New York City over the course of eight decades. This approach projects heat-related mortality until the end of the 21st century based on observed trends in adaptation over a substantial portion of the 20th century. In addition, we incorporate a range of new scenarios for population change until the end of the 21st century. We then estimate future heat-related deaths in New York City by combining the changing temperature-mortality relationship and population scenarios with downscaled temperature projections from the 33 global climate models (GCMs) and two Representative Concentration Pathways (RCPs).The median number of projected annual heat-related deaths across the 33 GCMs varied greatly by RCP and adaptation and population change scenario, ranging from 167 to 3331 in the 2080s compared to 638 heat-related deaths annually between 2000 and 2006.These findings provide a more complete picture of the range of potential future heat-related mortality risks across the 21st century in New York, and highlight the importance of both demographic change and adaptation responses in modifying future risks.

Analysis of a Community-based Intervention to Reduce Heat-related Illness during Heat Waves in Licheng, China: a Quasi-experimental Study.

Science.gov (United States)

Li, Jing; Xu, Xin; Wang, Jun; Zhao, Yun; Song, Xiu Ping; Liu, Zhi Dong; Cao, Li Na; Jiang, Bao Fa; Liu, Qi Yong

2016-11-01

To reduce health-related threats of heat waves, interventions have been implemented in many parts of the world. However, there is a lack of higher-level evidence concerning the intervention efficacy. This study aimed to determine the efficacy of an intervention to reduce the number of heat-related illnesses. A quasi-experimental design was employed by two cross-sectional surveys in the year 2014 and 2015, including 2,240 participants and 2,356 participants, respectively. Each survey was designed to include one control group and one intervention group, which conducted in Licheng, China. A representative sample was selected using a multistage sampling method. Data, collected from questionnaires about heat waves in 2014 and 2015, were analyzed using a difference-in-difference analysis and cost effectiveness analysis. Outcomes included changes in the prevalence of heat-related illnesses and cost-effectiveness variables. Relative to the control participants, the prevalence of heat-related illness in the intervention participants decreased to a greater extent in rural areas than in urban areas (OR=0.495 vs. OR=1.281). Moreover, the cost-effectiveness ratio in the intervention group was less than that in the control group (US$15.06 vs. US$15.69 per participant). Furthermore, to avoid one additional patient, the incremental cost-effectiveness ratio showed that an additional US$14.47 would be needed for the intervention compared to when no intervention was applied. The intervention program may be considered a worthwhile investment for rural areas that are more likely to experience heat waves. Meanwhile, corresponding improving measures should be presented towards urban areas. Future research should examine whether the intervention strategies could be spread out in other domestic or international regions where heat waves are usually experienced. Copyright © 2016 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

Heat-Related Mortality Projections for Cardiovascular and Respiratory Disease Under the Changing Climate in Beijing, China

Science.gov (United States)

Li, Tiantian; Ban, Jie; Horton, Radley M.; Bader, Daniel A.; Huang, Ganlin; Sun, Qinghua; Kinney, Patrick L.

2015-01-01

Because heat-related health effects tend to become more serious at higher temperatures, there is an urgent need to determine the mortality projection of specific heat-sensitive diseases to provide more detailed information regarding the variation of the sensitivity of such diseases. In this study, the specific mortality of cardiovascular and respiratory disease in Beijing was initially projected under five different global-scale General Circulation Models (GCMs) and two Representative Concentration Pathways scenarios (RCPs) in the 2020s, 2050s, and 2080s compared to the 1980s. Multi-model ensembles indicated cardiovascular mortality could increase by an average percentage of 18.4 percent, 47.8 percent, and 69.0 percent in the 2020s, 2050s, and 2080s under RCP 4.5, respectively, and by 16.6 percent, 73.8 percent and 134 percent in different decades respectively, under RCP 8.5 compared to the baseline range. The same increasing pattern was also observed in respiratory mortality. The heat-related deaths under the RCP 8.5 scenario were found to reach a higher number and to increase more rapidly during the 21st century compared to the RCP4.5 scenario, especially in the 2050s and the 2080s. The projection results show potential trends in cause-specific mortality in the context of climate change, and provide support for public health interventions tailored to specific climate-related future health risks.

Heat Mortality Versus Cold Mortality: A Study of Conflicting Databases in the United States.

Science.gov (United States)

Dixon, P. G.; Brommer, D. M.; Hedquist, B. C.; Kalkstein, A. J.; Goodrich, G. B.; Walter, J. C.; Dickerson, C. C., IV; Penny, S. J.; Cerveny, R. S.

2005-07-01

Studies, public reports, news reports, and Web sites cite a wide range of values associated with deaths resulting from excessive heat and excessive cold. For example, in the United States, the National Climatic Data Center's Storm Data statistics of temperature- related deaths are skewed heavily toward heat-related deaths, while the National Center for Health Statistics Compressed Mortality Database indicates the reverse—4 times more people die of “excessive cold” conditions in a given year than of “excessive heat.” In this study, we address the fundamental differences in the various temperature-related mortality databases, assess their benefits and limitations, and offer suggestions as to their use. These datasets suffer from potential incompleteness of source information, long compilation times, limited quality control, and the subjective determination of a direct versus indirect cause of death. In general, these separate mortality datasets should not be combined or compared, particularly with regard to policy determination. The use of gross mortality numbers appears to be one of the best means of determining temperature-related mortality, but those data must be detrended into order to remove a persistent winter-dominant death maximum and are difficult to obtain on a regional daily basis.

Detection of heat wave using Kalpana-1 VHRR land surface temperature product over India

Science.gov (United States)

Shah, Dhiraj; Pandya, Mehul R.; Pathak, Vishal N.; Darji, Nikunj P.; Trivedi, Himanshu J.

2016-05-01

Heat Waves can have notable impacts on human mortality, ecosystem, economics and energy supply. The effect of heat wave is much more intense during summer than the other seasons. During the period of April to June, spells of very hot weather occur over certain regions of India and global warming scenario may result in further increases of such temperature anomalies and corresponding heat waves conditions. In this paper, satellite observations have been used to detect the heat wave conditions prevailing over India for the period of May-June 2015. The Kalpana-1 VHRR derived land surface temperature (LST) products have been used in the analysis to detect the heat wave affected regions over India. Results from the analysis shows the detection of heat wave affected pixels over Indian land mass. It can be seen that during the study period the parts of the west India, Indo-gangetic plane, Telangana and part of Vidarbh was under severe heat wave conditions which is also confirmed with Automatic Weather Station (AWS) air temperature observations.

A biometeorology study of climate and heat-related morbidity in Phoenix from 2001 to 2006

Science.gov (United States)

Golden, Jay S.; Hartz, Donna; Brazel, Anthony; Luber, George; Phelan, Patrick

2008-07-01

Heat waves kill more people in the United States than hurricanes, tornadoes, earthquakes, and floods combined. Recently, international attention focused on the linkages and impacts of human health vulnerability to urban climate when Western Europe experienced over 30,000 excess deaths during the heat waves of the summer of 2003—surpassing the 1995 heat wave in Chicago, Illinois, that killed 739. While Europe dealt with heat waves, in the United States, Phoenix, Arizona, established a new all-time high minimum temperature for the region on July 15, 2003. The low temperature of 35.5°C (96°F) was recorded, breaking the previous all-time high minimum temperature record of 33.8°C (93°F). While an extensive literature on heat-related mortality exists, greater understanding of influences of heat-related morbidity is required due to climate change and rapid urbanization influences. We undertook an analysis of 6 years (2001 2006) of heat-related dispatches through the Phoenix Fire Department regional dispatch center to examine temporal, climatic and other non-spatial influences contributing to high-heat-related medical dispatch events. The findings identified that there were no significant variations in day-of-week dispatch events. The greatest incidence of heat-related medical dispatches occurred between the times of peak solar irradiance and maximum diurnal temperature, and during times of elevated human comfort indices (combined temperature and relative humidity).

Heat-Related Mortality in a Warming Climate: Projections for 12 U.S. Cities

Directory of Open Access Journals (Sweden)

Elisaveta P. Petkova

2014-10-01

Full Text Available Heat is among the deadliest weather-related phenomena in the United States, and the number of heat-related deaths may increase under a changing climate, particularly in urban areas. Regional adaptation planning is unfortunately often limited by the lack of quantitative information on potential future health responses. This study presents an assessment of the future impacts of climate change on heat-related mortality in 12 cities using 16 global climate models, driven by two scenarios of greenhouse gas emissions. Although the magnitude of the projected heat effects was found to differ across time, cities, climate models and greenhouse pollution emissions scenarios, climate change was projected to result in increases in heat-related fatalities over time throughout the 21st century in all of the 12 cities included in this study. The increase was more substantial under the high emission pathway, highlighting the potential benefits to public health of reducing greenhouse gas emissions. Nearly 200,000 heat-related deaths are projected to occur in the 12 cities by the end of the century due to climate warming, over 22,000 of which could be avoided if we follow a low GHG emission pathway. The presented estimates can be of value to local decision makers and stakeholders interested in developing strategies to reduce these impacts and building climate change resilience.

Heat-Related Mortality in a Warming Climate: Projections for 12 U.S. Cities

Science.gov (United States)

Petkova, Elisaveta P.; Bader, Daniel A.; Anderson, G. Brooke; Horton, Radley M.; Knowlton, Kim; Kinney, Patrick L.

2014-01-01

Heat is among the deadliest weather-related phenomena in the United States, and the number of heat-related deaths may increase under a changing climate, particularly in urban areas. Regional adaptation planning is unfortunately often limited by the lack of quantitative information on potential future health responses. This study presents an assessment of the future impacts of climate change on heat-related mortality in 12 cities using 16 global climate models, driven by two scenarios of greenhouse gas emissions. Although the magnitude of the projected heat effects was found to differ across time, cities, climate models and greenhouse pollution emissions scenarios, climate change was projected to result in increases in heat-related fatalities over time throughout the 21st century in all of the 12 cities included in this study. The increase was more substantial under the high emission pathway, highlighting the potential benefits to public health of reducing greenhouse gas emissions. Nearly 200,000 heat-related deaths are projected to occur in the 12 cities by the end of the century due to climate warming, over 22,000 of which could be avoided if we follow a low GHG emission pathway. The presented estimates can be of value to local decision makers and stakeholders interested in developing strategies to reduce these impacts and building climate change resilience.

The Impact of climate change on heat-related mortality in six major cities, South Korea, under representative concentration pathways (RCPs

Directory of Open Access Journals (Sweden)

Youngmin eKim

2014-02-01

Full Text Available Background: We aimed to quantify the excess mortality associated with increased temperature due to climate change in six major Korean cities under Representative Concentration Pathways (RCPs which are new emission scenarios designed for the fifth assessment report of the Intergovernmental Panel on Climate Change (IPCC. Methods: We first examined the association between daily mean temperature and mortality in each during the summertime (June to September from 2001 to 2008. This was done using a generalized linear Poisson model with adjustment for a long-term time trend, relative humidity, air pollutants, and day of the week. We then computed heat-related mortality attributable to future climate change using estimated mortality risks, projected future populations, and temperature increments for both future years 2041-2070 and 2071-2100 under RCP 4.5 and 8.5. We considered effects from added days with high temperatures over thresholds and shifted effects from high to higher temperature.Results: Estimated excess all-cause mortalities for six cities in Korea ranged from 500 (95% CI: 313-703 for 2041-2070 to 2,320 (95% CI: 1,430-3,281 deaths per year for 2071-2100 under two RCPs. Excess cardiovascular mortality was estimated to range from 192 (95% CI: 41-351 to 896 (95% CI: 185-1,694 deaths per year, covering about 38.5% of all-cause excess mortality. Increased rates of heat-related mortality were higher in cities located at relatively lower latitude than cities with higher latitude. Estimated excess mortality under RCP 8.5, a fossil fuel-intensive emission scenario, was more than twice as high compared with RCP 4.5, low to medium emission scenario.Conclusions: Excess mortality due to climate change is expected to be profound in the future showing spatial variation. Efforts to mitigate climate change can cause substantial health benefits via reducing heat-related mortality.

Mortality on extreme heat days using official thresholds in Spain: a multi-city time series analysis

Directory of Open Access Journals (Sweden)

Tobias Aurelio

2012-02-01

Full Text Available Abstract Background The 2003 heat wave had a high impact on mortality in Europe, which made necessary to develop heat health watch warning systems. In Spain this was carried-out by the Ministry of Health in 2004, being based on exceeding of city-specific simultaneous thresholds of minimum and maximum daily temperatures. The aim of this study is to assess effectiveness of the official thresholds established by the Ministry of Health for each provincial capital city, by quantifying and comparing the short-term effects of above-threshold days on total daily mortality. Methods Total daily mortality and minimum and maximum temperatures for the 52 capitals of province in Spain were collected during summer months (June to September for the study period 1995-2004. Data was analysed using GEE for Poisson regression. Relative Risk (RR of total daily mortality was quantified for the current day of official thresholds exceeded. Results The number of days in which the thresholds were exceeded show great inconsistency, with provinces with great number of exceeded days adjacent to provinces that did not exceed or rarely exceeded. The average overall excess risk of dying during an extreme heat day was about 25% (RR = 1.24; 95% confidence interval (CI = [1.19-1.30]. Relative risks showed a significant heterogeneity between cities (I2 = 54.9%. Western situation and low mean summer temperatures were associated with higher relative risks, suggesting thresholds may have been set too high in these areas. Conclusions This study confirmed that extreme heat days have a considerable impact on total daily mortality in Spain. Official thresholds gave consistent relative risk in the large capital cities. However, in some other cities thresholds

The potential impacts of climate variability and change on temperature-related morbidity and mortality in the United States.

Science.gov (United States)

McGeehin, M A; Mirabelli, M

2001-05-01

Heat and heat waves are projected to increase in severity and frequency with increasing global mean temperatures. Studies in urban areas show an association between increases in mortality and increases in heat, measured by maximum or minimum temperature, heat index, and sometimes, other weather conditions. Health effects associated with exposure to extreme and prolonged heat appear to be related to environmental temperatures above those to which the population is accustomed. Models of weather-mortality relationships indicate that populations in northeastern and midwestern U.S. cities are likely to experience the greatest number of illnesses and deaths in response to changes in summer temperature. Physiologic and behavioral adaptations may reduce morbidity and mortality. Within heat-sensitive regions, urban populations are the most vulnerable to adverse heat-related health outcomes. The elderly, young children, the poor, and people who are bedridden or are on certain medications are at particular risk. Heat-related illnesses and deaths are largely preventable through behavioral adaptations, including the use of air conditioning and increased fluid intake. Overall death rates are higher in winter than in summer, and it is possible that milder winters could reduce deaths in winter months. However, the relationship between winter weather and mortality is difficult to interpret. Other adaptation measures include heat emergency plans, warning systems, and illness management plans. Research is needed to identify critical weather parameters, the associations between heat and nonfatal illnesses, the evaluation of implemented heat response plans, and the effectiveness of urban design in reducing heat retention.

Temporal Changes in Mortality Related to Extreme Temperatures for 15 Cities in Northeast Asia: Adaptation to Heat and Maladaptation to Cold.

Science.gov (United States)

Chung, Yeonseung; Noh, Heesang; Honda, Yasushi; Hashizume, Masahiro; Bell, Michelle L; Guo, Yue-Liang Leon; Kim, Ho

2017-05-15

Understanding how the temperature-mortality association worldwide changes over time is crucial to addressing questions of human adaptation under climate change. Previous studies investigated the temporal changes in the association over a few discrete time frames or assumed a linear change. Also, most studies focused on attenuation of heat-related mortality and studied the United States or Europe. This research examined continuous temporal changes (potentially nonlinear) in mortality related to extreme temperature (both heat and cold) for 15 cities in Northeast Asia (1972-2009). We used a generalized linear model with splines to simultaneously capture 2 types of nonlinearity: nonlinear association between temperature and mortality and nonlinear change over time in the association. We combined city-specific results to generate country-specific results using Bayesian hierarchical modeling. Cold-related mortality remained roughly constant over decades and slightly increased in the late 2000s, with a larger increase for cardiorespiratory deaths than for deaths from other causes. Heat-related mortality rates have decreased continuously over time, with more substantial decrease in earlier decades, for older populations and for cardiorespiratory deaths. Our findings suggest that future assessment of health effects of climate change should account for the continuous changes in temperature-related health risk and variations by factors such as age, cause of death, and location. © Crown copyright 2017.

Trends in the mortality effects of hot spells in central Europe: adaptation to climate change?

Science.gov (United States)

Kysely, J.; Plavcova, E.

2013-12-01

Europe has recently been affected by several long-lasting and severe heat waves, particularly in July-August 2003 (western Europe), June-July 2006 (central Europe), July 2007 (southeastern Europe) and July 2010 (western Russia). The heat waves influenced many sectors of human activities, with enormous socio-economic and environmental impacts. With estimated death tolls exceeding 50,000, the 2003 and 2010 heat waves were the worst natural disasters in Europe over the last 50 years, yielding an example of how seriously may also high-income societies be affected by climate change. The present study examines temporal changes in mortality associated with spells of large positive temperature anomalies (hot spells) in the population of the Czech Republic (around 10 million inhabitants, central Europe). Declining trends in the mortality impacts since 1986 are found, in spite of rising temperature trends. The findings remain unchanged if possible confounding effects of within-season acclimatization to heat and the mortality displacement effect are taken into account, and they are similar for all-cause mortality and mortality due to cardiovascular diseases. Recent positive socio-economic development, following the collapse of communism in central and eastern Europe in 1989, and better public awareness of heat-related risks are likely the primary causes of the declining vulnerability in the examined population (Kyselý and Plavcová, 2012). The results are also consistent with those reported for other developed regions of the world (the US, western Europe, Australia) and suggest that climate change may have relatively little influence on heat-related deaths, since changes in other factors that affect vulnerability of the population are dominant instead of temperature trends. It is essential to better understand the observed non-stationarity of the temperature-mortality relationship and the role of adaptation and its limits, both physiological and technological, and to address

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

Science.gov (United States)

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.

Spatial patterns of heat-related cardiovascular mortality in the Czech Republic

Czech Academy of Sciences Publication Activity Database

Urban, A.; Burkart, K.; Kyselý, J.; Schuster, Ch.; Plavcová, E.; Hanzlíková, Hana; Štěpánek, P.; Lakes, T.

2016-01-01

Roč. 13, č. 3 (2016), 284/1-284/19 ISSN 1660-4601 Institutional support: RVO:67985530 Keywords : heat stress * mortality * spatial differences Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 2.101, year: 2016

Identifying heat-related deaths by using medical examiner and vital statistics data: Surveillance analysis and descriptive epidemiology - Oklahoma, 1990-2011.

Science.gov (United States)

Johnson, Matthew G; Brown, Sheryll; Archer, Pam; Wendelboe, Aaron; Magzamen, Sheryl; Bradley, Kristy K

2016-10-01

Approximately 660 deaths occur annually in the United States associated with excess natural heat. A record heat wave in Oklahoma during 2011 generated increased interest concerning heat-related mortality among public health preparedness partners. We aimed to improve surveillance for heat-related mortality and better characterize heat-related deaths in Oklahoma during 1990-2011, and to enhance public health messaging during future heat emergencies. Heat-related deaths were identified by querying vital statistics (VS) and medical examiner (ME) data during 1990-2011. Case inclusion criteria were developed by using heat-related International Classification of Diseases codes, cause-of-death nomenclature, and ME investigation narrative. We calculated sensitivity and predictive value positive (PVP) for heat-related mortality surveillance by using VS and ME data and performed a descriptive analysis. During the study period, 364 confirmed and probable heat-related deaths were identified when utilizing both data sets. ME reports had 87% sensitivity and 74% PVP; VS reports had 80% sensitivity and 52% PVP. Compared to Oklahoma's general population, decedents were disproportionately male (67% vs. 49%), aged ≥65 years (46% vs. 14%), and unmarried (78% vs. 47%). Higher rates of heat-related mortality were observed among Blacks. Of 95 decedents with available information, 91 (96%) did not use air conditioning. Linking ME and VS data sources together and using narrative description for case classification allows for improved case ascertainment and surveillance data quality. Males, Blacks, persons aged ≥65 years, unmarried persons, and those without air conditioning carry a disproportionate burden of the heat-related deaths in Oklahoma. Published by Elsevier Inc.

Relationships Between Excessive Heat and Daily Mortality over the Coterminous U.S

Science.gov (United States)

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

2015-01-01

In the United States, extreme heat is the most deadly weather-related hazard. In the face of a warming climate and urbanization, it is very likely that extreme heat events (EHEs) will become more common and more severe in the U.S. Using National Land Data Assimilation System (NLDAS) meteorological reanalysis data, we have developed several measures of extreme heat to enable assessments of the impacts of heat on public health over the coterminous U.S. These measures include daily maximum and minimum air temperatures, daily maximum heat indices and a new heat stress variable called Net Daily Heat Stress (NDHS) that gives an integrated measure of heat stress (and relief) over the course of a day. All output has been created on the NLDAS 1/8 degree (approximately 12 km) grid and aggregated to the county level, which is the preferred geographic scale of analysis for public health researchers. County-level statistics have been made available through the Centers for Disease Control and Prevention (CDC) via the Wide-ranging Online Data for Epidemiologic Research (WONDER) system. We have examined the relationship between excessive heat events, as defined in eight different ways from the various daily heat metrics, and heat-related and all-cause mortality defined in CDC's National Center for Health Statistics 'Multiple Causes of Death 1999-2010' dataset. To do this, we linked daily, county-level heat mortality counts with EHE occurrence based on each of the eight EHE definitions by region and nationally for the period 1999-2010. The objectives of this analysis are to determine (1) whether heat-related deaths can be clearly tied to excessive heat events, (2) what time lags are critical for predicting heat-related deaths, and (3) which of the heat metrics correlates best with mortality in each US region. Results show large regional differences in the correlations between heat and mortality. Also, the heat metric that provides the best indicator of mortality varied by region

Future heat waves and surface ozone

Science.gov (United States)

Meehl, Gerald A.; Tebaldi, Claudia; Tilmes, Simone; Lamarque, Jean-Francois; Bates, Susan; Pendergrass, Angeline; Lombardozzi, Danica

2018-06-01

A global Earth system model is used to study the relationship between heat waves and surface ozone levels over land areas around the world that could experience either large decreases or little change in future ozone precursor emissions. The model is driven by emissions of greenhouse gases and ozone precursors from a medium-high emission scenario (Representative Concentration Pathway 6.0–RCP6.0) and is compared to an experiment with anthropogenic ozone precursor emissions fixed at 2005 levels. With ongoing increases in greenhouse gases and corresponding increases in average temperature in both experiments, heat waves are projected to become more intense over most global land areas (greater maximum temperatures during heat waves). However, surface ozone concentrations on future heat wave days decrease proportionately more than on non-heat wave days in areas where ozone precursors are prescribed to decrease in RCP6.0 (e.g. most of North America and Europe), while surface ozone concentrations in heat waves increase in areas where ozone precursors either increase or have little change (e.g. central Asia, the Mideast, northern Africa). In the stabilized ozone precursor experiment, surface ozone concentrations increase on future heat wave days compared to non-heat wave days in most regions except in areas where there is ozone suppression that contributes to decreases in ozone in future heat waves. This is likely associated with effects of changes in isoprene emissions at high temperatures (e.g. west coast and southeastern North America, eastern Europe).

Unidirectional spin-wave heat conveyer.

Science.gov (United States)

An, T; Vasyuchka, V I; Uchida, K; Chumak, A V; Yamaguchi, K; Harii, K; Ohe, J; Jungfleisch, M B; Kajiwara, Y; Adachi, H; Hillebrands, B; Maekawa, S; Saitoh, E

2013-06-01

When energy is introduced into a region of matter, it heats up and the local temperature increases. This energy spontaneously diffuses away from the heated region. In general, heat should flow from warmer to cooler regions and it is not possible to externally change the direction of heat conduction. Here we show a magnetically controllable heat flow caused by a spin-wave current. The direction of the flow can be switched by applying a magnetic field. When microwave energy is applied to a region of ferrimagnetic Y3Fe5O12, an end of the magnet far from this region is found to be heated in a controlled manner and a negative temperature gradient towards it is formed. This is due to unidirectional energy transfer by the excitation of spin-wave modes without time-reversal symmetry and to the conversion of spin waves into heat. When a Y3Fe5O12 film with low damping coefficients is used, spin waves are observed to emit heat at the sample end up to 10 mm away from the excitation source. The magnetically controlled remote heating we observe is directly applicable to the fabrication of a heat-flow controller.

Heat waves and warm periods in Slovakia

Science.gov (United States)

Faško, Pavel; Bochníček, Oliver; Markovič, Ladislav; Švec, Marek

2016-04-01

The scenarios of climate change caused by human activity show that frequency of occurrence and extent of heat waves in the interior of Europe is increasing. Among the most exposed regions in this regard should the area of southeastern and eastern Austria and south-western Slovakia. The relatively faster increase in the number of heat waves in this area is related also to potential desertification in this region just east of the Alps, since during summer, weather fronts advancing from the west are consequently losing their original features and moderating influence. Summer weather patterns for this area should in the future more closely remind climate typical for some inland areas of southwestern, southern and southeastern Europe. A certain shift of climate zones from south to north should thus modify future climate and Slovakia. Despite the complex natural conditions the existing trends derived from results of meteorological measurements and observations are clear and they confirm warming of climate in this region. Observations and measurements in the recent years of the 21st century confirm, that heat waves are no longer rare phenomenon during summer, but are systematically appearing even in colder regions of northern Slovakia. What is very remarkable and will be necessary to pay more attention to, is the fact that these heat waves are expanding into previously unaffected areas, associated with the lack of rainfall and drought, on larger regional scale. In this study heat wave periods and individual heat events and days are statistically identified in the time series characteristics of air temperature at selected meteorological stations for the period from the mid-20th century until 2015, in case of available historical data even for longer period.

Ranking of European Capitals According to the Impact of Future Heat Waves

Science.gov (United States)

Smid, M.; Costa, A. C.; Russo, S.; Pebesma, E. J.; Canut, C. G.

2017-12-01

In warming Europe, we are witnessing a growth in urban population with aging trend, which will make the society more vulnerable to extreme heat waves. In the period 1950-2015 the occurrence of extreme heat waves increased across European capitals. As an example, Moscow was hit by the strongest heat wave of the present era, killing more than ten thousand people. Here we focus on larger metropolitan areas of European capitals. By using observations and an ensemble of eight EURO-CORDEX models under the RCP8.5 scenario, we calculate a suite of temperature based climate indices. We introduce a simple ranking procedure based on ensemble predictions using the mean of metropolitan grid cells for each capital, and population density as a proxy to quantify the future impact. Results show that the selected ensemble provides solid simulation of climate characteristics over most of the targeted metropolitan areas. All the investigated European metropolitan areas will be more vulnerable to extreme heat in the coming decades. Based on the impact ranking, the results reveal that in near, but mainly in distant future, the extreme heat events in European capitals will be not exclusive to traditionally exposed areas such as the Mediterranean and the Iberian Peninsula. The ranking of European capitals based on their vulnerability to the extreme heat could be of paramount importance to the decision makers in order to mitigate the heat related mortality, especially with the foreseen increase of global mean temperature. Acknowledgments: The authors gratefully acknowledge the support of Geoinformatics: Enabling Open Cities (GEO-C), the project funded by the European Commission within the Marie Skłodowska-Curie Actions, International Training Networks (ITN), European Joint Doctorates (EJD). Grant Agreement number 642332 — GEO-C — H2020-MSCA-ITN-2014.

Marine Heat Waves Hazard 3D Maps and the Risk for Low Motility Organisms in a Warming Mediterranean Sea

Directory of Open Access Journals (Sweden)

Giovanni Galli

2017-05-01

Full Text Available Frequency and severity of heat waves is expected to increase as a consequence of climate change with important impacts on human and ecosystems health. However, while many studies explored the projected occurrence of hot extremes on terrestrial systems, few studies dealt with marine systems, so that both the expected change in marine heat waves occurrence and the effects on marine organisms and ecosystems remain less understood and surprisingly poorly quantified. Here we: (i assess how much more frequent, severe, and depth-penetrating marine heat waves will be in the Mediterranean area in the next decades by post-processing the output of an ocean general circulation model; and (ii show that heat waves increase will impact on many species that live in shallow waters and have reduced motility, and related economic activities. This information is made available also as a dataset of temperature threshold exceedance indexes that can be used in combination with biological information to produce risk assessment maps for target species or biomes across the whole Mediterranean Sea. As case studies we compared projected heat waves occurrence with thermotolerance thresholds of low motility organisms. Results suggest a deepening of the survival horizon for red coral (Corallium rubrum, a commercially exploited benthic species already subjected to heat-related mass mortality events and coralligenous reefs as well as a reduction of suitable farming sites for the mussel Mythilus galloprovincialis. In recent years Mediterranean circalittoral ecosystems (coralligenous have been severely and repeatedly impacted by marine heat waves. Our results support that equally deleterious events are expected in the near future also for other ecologically important habitats (e.g., seagrass meadows and aquaculture activities (bivalvae, and point at the need for mitigation strategies.

Chiral heat wave and mixing of magnetic, vortical and heat waves in chiral media

International Nuclear Information System (INIS)

Chernodub, M.N.

2016-01-01

We show that a hot rotating fluid of relativistic chiral fermions possesses a new gapless collective mode associated with coherent propagation of energy density and chiral density waves along the axis of rotation. This mode, which we call the Chiral Heat Wave, emerges due to a mixed gauge-gravitational anomaly. At finite density the Chiral Heat Wave couples to the Chiral Vortical Wave while in the presence of an external magnetic field it mixes with the Chiral Magnetic Wave. The coupling of the Chiral Magnetic and Chiral Vortical Waves is also demonstrated. We find that the coupled waves — which are coherent fluctuations of the vector, axial and energy currents — have generally different velocities compared to the velocities of the individual waves.

Influence of Gas-Liquid Interface on Temperature Wave of Pulsating Heat Pipe

Directory of Open Access Journals (Sweden)

Ying Zhang

2018-01-01

Full Text Available The influence of the interface on the amplitude and phase of the temperature wave and the relationship between the attenuation of the temperature wave and the gas-liquid two-phase physical parameters are studied during the operation of the pulsating heat pipe. The numerical simulation shows that the existence of the phase interface changes the direction of the temperature gradient during the propagation of the temperature wave, which increases the additional “thermal resistance.” The relative size of the gas-liquid two-phase thermal conductivity affects the propagation direction of heat flow at phase interface directly. The blockage of the gas plug causes hysteresis in the phase of the temperature wave, the relative size of the gas-liquid two-phase temperature coefficient will gradually increase the phase of the temperature wave, and the time when the heat flow reaches the peak value is also advanced. The attenuation of the temperature wave is almost irrelevant to the absolute value of the density, heat capacity, and thermal conductivity of the gas-liquid two phases, and the ratio of the thermal conductivity of the gas-liquid two phases is related. When the temperature of the heat pipe was changed, the difference of heat storage ability between gas and liquid will lead to the phenomenon of heat reflux and becomes more pronounced with the increases of the temperature wave.

Wave heating of the solar atmosphere

Science.gov (United States)

Arregui, Iñigo

2015-04-01

Magnetic waves are a relevant component in the dynamics of the solar atmosphere. Their significance has increased because of their potential as a remote diagnostic tool and their presumed contribution to plasma heating processes. We discuss our current understanding of coronal heating by magnetic waves, based on recent observational evidence and theoretical advances. The discussion starts with a selection of observational discoveries that have brought magnetic waves to the forefront of the coronal heating discussion. Then, our theoretical understanding of the nature and properties of the observed waves and the physical processes that have been proposed to explain observations are described. Particular attention is given to the sequence of processes that link observed wave characteristics with concealed energy transport, dissipation and heat conversion. We conclude with a commentary on how the combination of theory and observations should help us to understand and quantify magnetic wave heating of the solar atmosphere.

Fine-scale spatial variability of heat-related mortality in Philadelphia County, USA, from 1983-2008: a case-series analysis

Directory of Open Access Journals (Sweden)

Hondula David M

2012-03-01

Full Text Available Abstract Background High temperature and humidity conditions are associated with short-term elevations in the mortality rate in many United States cities. Previous research has quantified this relationship in an aggregate manner over large metropolitan areas, but within these areas the response may differ based on local-scale variability in climate, population characteristics, and socio-economic factors. Methods We compared the mortality response for 48 Zip Code Tabulation Areas (ZCTAs comprising Philadelphia County, PA to determine if certain areas are associated with elevated risk during high heat stress conditions. A randomization test was used to identify mortality exceedances for various apparent temperature thresholds at both the city and local scale. We then sought to identify the environmental, demographic, and social factors associated with high-risk areas via principal components regression. Results Citywide mortality increases by 9.3% on days following those with apparent temperatures over 34°C observed at 7:00 p.m. local time. During these conditions, elevated mortality rates were found for 10 of the 48 ZCTAs concentrated in the west-central portion of the County. Factors related to high heat mortality risk included proximity to locally high surface temperatures, low socioeconomic status, high density residential zoning, and age. Conclusions Within the larger Philadelphia metropolitan area, there exists statistically significant fine-scale spatial variability in the mortality response to high apparent temperatures. Future heat warning systems and mitigation and intervention measures could target these high risk areas to reduce the burden of extreme weather on summertime morbidity and mortality.

Vulnerability to temperature-related mortality in Seoul, Korea

International Nuclear Information System (INIS)

Son, Ji-Young; Anderson, G Brooke; Bell, Michelle L; Lee, Jong-Tae

2011-01-01

Studies indicate that the mortality effects of temperature may vary by population and region, although little is known about the vulnerability of subgroups to these risks in Korea. This study examined the relationship between temperature and cause-specific mortality for Seoul, Korea, for the period 2000-7, including whether some subgroups are particularly vulnerable with respect to sex, age, education and place of death. The authors applied time-series models allowing nonlinear relationships for heat- and cold-related mortality, and generated exposure-response curves. Both high and low ambient temperatures were associated with increased risk for daily mortality. Mortality risk was 10.2% (95% confidence interval 7.43, 13.0%) higher at the 90th percentile of daily mean temperatures (25 deg. C) compared to the 50th percentile (15 deg. C). Mortality risk was 12.2% (3.69, 21.3%) comparing the 10th (-1 deg. C) and 50th percentiles of temperature. Cardiovascular deaths showed a higher risk to cold, whereas respiratory deaths showed a higher risk to heat effect, although the differences were not statistically significant. Susceptible populations were identified such as females, the elderly, those with no education, and deaths occurring outside of a hospital for heat- and cold-related total mortality. Our findings provide supportive evidence of a temperature-mortality relationship in Korea and indicate that some subpopulations are particularly vulnerable.

Socioenvironmental factors associated with heat and cold-related mortality in Vadu HDSS, western India: a population-based case-crossover study

Science.gov (United States)

Ingole, Vijendra; Kovats, Sari; Schumann, Barbara; Hajat, Shakoor; Rocklöv, Joacim; Juvekar, Sanjay; Armstrong, Ben

2017-10-01

Ambient temperatures (heat and cold) are associated with mortality, but limited research is available about groups most vulnerable to these effects in rural populations. We estimated the effects of heat and cold on daily mortality among different sociodemographic groups in the Vadu HDSS area, western India. We studied all deaths in the Vadu HDSS area during 2004-2013. A conditional logistic regression model in a case-crossover design was used. Separate analyses were carried out for summer and winter season. Odds ratios (OR) and 95% confidence intervals (CI) were estimated for total mortality and population subgroups. Temperature above a threshold of 31 °C was associated with total mortality (OR 1.48, CI = 1.05-2.09) per 1 °C increase in daily mean temperature. Odds ratios were higher among females (OR 1.93; CI = 1.07-3.47), those with low education (OR 1.65; CI = 1.00-2.75), those owing larger agricultural land (OR 2.18; CI = 0.99-4.79), and farmers (OR 1.70; CI = 1.02-2.81). In winter, per 1 °C decrease in mean temperature, OR for total mortality was 1.06 (CI = 1.00-1.12) in lag 0-13 days. High risk of cold-related mortality was observed among people occupied in housework (OR = 1.09; CI = 1.00-1.19). Our study suggests that both heat and cold have an impact on mortality particularly heat, but also, to a smaller degree, cold have an impact. The effects may differ partly by sex, education, and occupation. These findings might have important policy implications in preventing heat and cold effects on particularly vulnerable groups of the rural populations in low and middle-income countries with hot semi-arid climate.

Projecting future temperature-related mortality in three largest Australian cities

International Nuclear Information System (INIS)

Guo, Yuming; Li, Shanshan; Liu, De Li; Chen, Dong; Williams, Gail; Tong, Shilu

2016-01-01

We estimated net annual temperature-related mortality in Brisbane, Sydney and Melbourne in Australia using 62 global climate model projections under three IPPC SRES CO_2 emission scenarios (A2, A1B and B1). In all cities, all scenarios resulted in increases in summer temperature-related deaths for future decades, and decreases in winter temperature-related deaths. However, Brisbane and Sydney will increase the net annual temperature-related deaths in the future, while a slight decrease will happen in Melbourne. Additionally, temperature-related mortality will largely increase beyond the summer (including January, February, March, November and December) in Brisbane and Sydney, while temperature-related mortality will largely decrease beyond the winter in Melbourne. In conclusion, temperature increases for Australia are expected to result in a decreased burden of cold-related mortality and an increased burden of heat-related mortality, but the balance of these differences varied by city. In particular, the seasonal patterns in temperature-related deaths will be shifted. - Temperature increases result in a decreased burden of cold-related mortality and an increased burden of heat-related mortality, but the balance of these differences varied by city in Australia.

Alfven wave heating in a tokamak reactor

International Nuclear Information System (INIS)

Borg, G.G.; Appert, K.; Knight, A.J.; Lister, J.B.; Vaclavik, J.

1990-01-01

A number of features of Alfven wave heating make it potentially attractive for use in large tokamak reactors. Among them are the availability and relativity low cost of the power supplies, the potential ability to act selectively on the current profile, and the probable absence of operational limits in size, fields or density. The physics of Alfven wave heating in a large tokamak is assessed. Present theoretical understanding of mode coupling and antenna loading is extrapolated to a large machine. The problem of a recessed antenna is analysed. Calculations of loading and discussion of various heating scenarios for the particular case of NET are also presented. (author). 23 refs, 18 figs, 4 tabs

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

Science.gov (United States)

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

Ion Bernstein wave heating research

International Nuclear Information System (INIS)

Ono, Masayuki.

1992-03-01

Ion Bernstein wave heating (IBWH) utilizes the ion Bernstein wave (IBW), a hot plasma wave, to carry the radio frequency (rf) power to heat tokamak reactor core. Earlier wave accessibility studies have shown that this finite-Larmor-radius (FLR) mode should penetrate into a hot dense reactor plasma core without significant attenuation. Moreover, the IBW's low phase velocity (ω/k perpendicular ∼ V Ti much-lt V α ) greatly reduces the otherwise serious wave absorption by the 3.5 MeV fusion α-particles. In addition, the property of IBW's that k perpendicular ρ i ∼ 1 makes localized bulk ion heating possible at the ion cyclotron harmonic layers. Such bulk ion heating can prove useful in optimizing fusion reactivity. In another vein, with proper selection of parameters, IBW's can be made subject to strong localized electron Landau damping near the major ion cyclotron harmonic resonance layers. This property can be useful, for example, for rf current drive in the reactor plasma core. This paper discusses this research

The 2011 marine heat wave in Cockburn Sound, southwest Australia

Directory of Open Access Journals (Sweden)

T. H. Rose

2012-07-01

Full Text Available Over 2000 km of Western Australian coastline experienced a significant marine heat wave in February and March 2011. Seawater temperature anomalies of +2–4 °C were recorded at a number of locations, and satellite-derived SSTs (sea surface temperatures were the highest on record. Here, we present seawater temperatures from southwestern Australia and describe, in detail, the marine climatology of Cockburn Sound, a large, multiple-use coastal embayment. We compared temperature and dissolved oxygen levels in 2011 with data from routine monitoring conducted from 2002–2010. A significant warming event, 2–4 °C in magnitude, persisted for > 8 weeks, and seawater temperatures at 10 to 20 m depth were significantly higher than those recorded in the previous 9 yr. Dissolved oxygen levels were depressed at most monitoring sites, being ~ 2 mg l⁻¹ lower than usual in early March 2011. Ecological responses to short-term extreme events are poorly understood, but evidence from elsewhere along the Western Australian coastline suggests that the heat wave was associated with high rates of coral bleaching; fish, invertebrate and macroalgae mortalities; and algal blooms. However, there is a paucity of historical information on ecologically-sensitive habitats and taxa in Cockburn Sound, so that formal examinations of biological responses to the heat wave were not possible. The 2011 heat wave provided insights into conditions that may become more prevalent in Cockburn Sound, and elsewhere, if the intensity and frequency of short-term extreme events increases as predicted.

Effectiveness of National Weather Service heat alerts in preventing mortality in 20 US cities.

Science.gov (United States)

Weinberger, Kate R; Zanobetti, Antonella; Schwartz, Joel; Wellenius, Gregory A

2018-04-09

Extreme heat is a well-documented public health threat. The US National Weather Service (NWS) issues heat advisories and warnings (collectively, "heat alerts") in advance of forecast extreme heat events. The effectiveness of these alerts in preventing deaths remains largely unknown. To quantify the change in mortality rates associated with heat alerts in 20 US cities between 2001 and 2006. Because NWS heat alerts are issued based on forecast weather and these forecasts are imperfect, in any given location there exists a set of days of similar observed heat index in which heat alerts have been issued for some days but not others. We used a case-crossover design and conditional logistic regression to compare mortality rates on days with versus without heat alerts among such eligible days, adjusting for maximum daily heat index and temporal factors. We combined city-specific estimates into a summary measure using standard random-effects meta-analytic techniques. Overall, NWS heat alerts were not associated with lower mortality rates (percent change in rate: -0.5% [95% CI: -2.8, 1.9]). In Philadelphia, heat alerts were associated with a 4.4% (95% CI: -8.3, -0.3) lower mortality rate or an estimated 45.1 (95% empirical CI: 3.1, 84.1) deaths averted per year if this association is assumed to be causal. No statistically significant beneficial association was observed in other individual cities. Our results suggest that between 2001 and 2006, NWS heat alerts were not associated with lower mortality in most cities studied, potentially missing a valuable opportunity to avert a substantial number of heat-related deaths. These results highlight the need to better link alerts to effective communication and intervention strategies to reduce heat-related mortality. Copyright © 2018 Elsevier Ltd. All rights reserved.

Modification of Heat-Related Mortality in an Elderly Urban Population by Vegetation (Urban Green) and Proximity to Water (Urban Blue): Evidence from Lisbon, Portugal.

Science.gov (United States)

Burkart, Katrin; Meier, Fred; Schneider, Alexandra; Breitner, Susanne; Canário, Paulo; Alcoforado, Maria João; Scherer, Dieter; Endlicher, Wilfried

2016-07-01

Urban populations are highly vulnerable to the adverse effects of heat, with heat-related mortality showing intra-urban variations that are likely due to differences in urban characteristics and socioeconomic status. We investigated the influence of urban green and urban blue, that is, urban vegetation and water bodies, on heat-related excess mortality in the elderly > 65 years old in Lisbon, Portugal, between 1998 and 2008. We used remotely sensed data and geographic information to determine the amount of urban vegetation and the distance to bodies of water (the Atlantic Ocean and the Tagus Estuary). Poisson generalized additive models were fitted, allowing for the interaction between equivalent temperature [universal thermal climate index (UTCI)] and quartiles of urban greenness [classified using the Normalized Difference Vegetation Index (NDVI)] and proximity to water (≤ 4 km vs. > 4 km), while adjusting for potential confounders. The association between mortality and a 1°C increase in UTCI above the 99th percentile (24.8°C) was stronger for areas in the lowest NDVI quartile (14.7% higher; 95% CI: 1.9, 17.5%) than for areas in the highest quartile (3.0%; 95% CI: 2.0, 4.0%). In areas > 4 km from water, a 1°C increase in UTCI above the 99th percentile was associated with a 7.1% increase in mortality (95% CI: 6.2, 8.1%), whereas in areas ≤ 4 km from water, the estimated increase in mortality was only 2.1% (95% CI: 1.2, 3.0%). Urban green and blue appeared to have a mitigating effect on heat-related mortality in the elderly population in Lisbon. Increasing the amount of vegetation may be a good strategy to counteract the adverse effects of heat in urban areas. Our findings also suggest potential benefits of urban blue that may be present several kilometers from a body of water. Burkart K, Meier F, Schneider A, Breitner S, Canário P, Alcoforado MJ, Scherer D, Endlicher W. 2016. Modification of heat-related mortality in an elderly urban population by

Humid Heat Waves at different warming levels

Science.gov (United States)

Russo, S.; Sillmann, J.; Sterl, A.

2017-12-01

The co-occurrence of consecutive hot and humid days during a heat wave can strongly affect human health. Here, we quantify humid heat wave hazard in the recent past and at different levels of global warming.We find that the magnitude and apparent temperature peak of heat waves, such as the ones observed in Chicago in 1995 and China in 2003, have been strongly amplified by humidity. Climate model projections suggest that the percentage of area where heat wave magnitude and peak are amplified by humidity increases with increasing warming levels. Considering the effect of humidity at 1.5o and 2o global warming, highly populated regions, such as the Eastern US and China, could experience heat waves with magnitude greater than the one in Russia in 2010 (the most severe of the present era).The apparent temperature peak during such humid-heat waves can be greater than 55o. According to the US Weather Service, at this temperature humans are very likely to suffer from heat strokes. Humid-heat waves with these conditions were never exceeded in the present climate, but are expected to occur every other year at 4o global warming. This calls for respective adaptation measures in some key regions of the world along with international climate change mitigation efforts.

Wave propagation model of heat conduction and group speed

Science.gov (United States)

Zhang, Long; Zhang, Xiaomin; Peng, Song

2018-03-01

In view of the finite relaxation model of non-Fourier's law, the Cattaneo and Vernotte (CV) model and Fourier's law are presented in this work for comparing wave propagation modes. Independent variable translation is applied to solve the partial differential equation. Results show that the general form of the time spatial distribution of temperature for the three media comprises two solutions: those corresponding to the positive and negative logarithmic heating rates. The former shows that a group of heat waves whose spatial distribution follows the exponential function law propagates at a group speed; the speed of propagation is related to the logarithmic heating rate. The total speed of all the possible heat waves can be combined to form the group speed of the wave propagation. The latter indicates that the spatial distribution of temperature, which follows the exponential function law, decays with time. These features show that propagation accelerates when heated and decelerates when cooled. For the model media that follow Fourier's law and correspond to the positive heat rate of heat conduction, the propagation mode is also considered the propagation of a group of heat waves because the group speed has no upper bound. For the finite relaxation model with non-Fourier media, the interval of group speed is bounded and the maximum speed can be obtained when the logarithmic heating rate is exactly the reciprocal of relaxation time. And for the CV model with a non-Fourier medium, the interval of group speed is also bounded and the maximum value can be obtained when the logarithmic heating rate is infinite.

Heat wave vulnerability classification of residential buildings

NARCIS (Netherlands)

Heijden, van der M.G.M.; Blocken, B.J.E.; Hensen, J.L.M.

2012-01-01

General circulation models of climate change predict that the intensity and frequency of heat waves will increase, which are a significant threat to public health (Luber and McGeehin 2008). The effect of heat waves on the public health became apparent during the 2003 heat wave in France, where

Should electric fans be used during a heat wave?

Science.gov (United States)

Jay, Ollie; Cramer, Matthew N; Ravanelli, Nicholas M; Hodder, Simon G

2015-01-01

Heat waves continue to claim lives, with the elderly and poor at greatest risk. A simple and cost-effective intervention is an electric fan, but public health agencies warn against their use despite no evidence refuting their efficacy in heat waves. A conceptual human heat balance model can be used to estimate the evaporative requirement for heat balance, the potential for evaporative heat loss from the skin, and the predicted sweat rate, with and without an electrical fan during heat wave conditions. Using criteria defined by the literature, it is clear that fans increase the predicted critical environmental limits for both the physiological compensation of endogenous/exogenous heat, and the onset of cardiovascular strain by an air temperature of ∼3-4 °C, irrespective of relative humidity (RH) for the young and elderly. Even above these critical limits, fans would apparently still provide marginal benefits at air temperatures as high as 51.1 °C at 10%RH for young adults and 48.1 °C at 10%RH for the elderly. Previous concerns that dehydration would be exacerbated with fan use do not seem likely, except under very hot (>40 °C) and dry (fans by a minor amount (∼20-30 mL/h). Relative to the peak outdoor environmental conditions reported during ten of the most severe heat waves in recent history, fan use would be advisable in all of these situations, even when reducing the predicted maximum sweat output for the elderly. The protective benefit of fans appears to be underestimated by current guidelines. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Alfven wave heating

International Nuclear Information System (INIS)

Stix, H.

1981-01-01

The physics of Alfven-wave heating is particularly sensitive to the character of the linear mode conversion which occurs at the Alfven resonance layer. Parameter changes can profoundly affect both the location within the plasma and the mechanism for the power absorption. Under optimal conditions the heating power may be absorbed by electron Landau damping and by electron transit-time magnetic pumping in the plasma interior, or by the same processes acting near the resonance layer on the mode-converted kinetic Alfven wave. The method is outlined for computing the coefficients for reflection, transmission and absorption at the resonance layer and some representative results are offered

Cold and heat waves in the United States.

Science.gov (United States)

Barnett, A G; Hajat, S; Gasparrini, A; Rocklöv, J

2012-01-01

Extreme cold and heat waves, characterized by a number of cold or hot days in succession, place a strain on people's cardiovascular and respiratory systems. The increase in deaths due to these waves may be greater than that predicted by extreme temperatures alone. We examined cold and heat waves in 99 US cities for 14 years (1987-2000) and investigated how the risk of death depended on the temperature threshold used to define a wave, and a wave's timing, duration and intensity. We defined cold and heat waves using temperatures above and below cold and heat thresholds for two or more days. We tried five cold thresholds using the first to fifth percentiles of temperature, and five heat thresholds using the 95-99 percentiles. The extra wave effects were estimated using a two-stage model to ensure that their effects were estimated after removing the general effects of temperature. The increases in deaths associated with cold waves were generally small and not statistically significant, and there was even evidence of a decreased risk during the coldest waves. Heat waves generally increased the risk of death, particularly for the hottest heat threshold. Cold waves of a colder intensity or longer duration were not more dangerous. Cold waves earlier in the cool season were more dangerous, as were heat waves earlier in the warm season. In general there was no increased risk of death during cold waves above the known increased risk associated with cold temperatures. Cold or heat waves earlier in the cool or warm season may be more dangerous because of a build up in the susceptible pool or a lack of preparedness for extreme temperatures. Copyright © 2011 Elsevier Inc. All rights reserved.

The great 2006 heat wave over California and Nevada: Signal of an increasing trend

Science.gov (United States)

Gershunov, A.; Cayan, D.R.; Iacobellis, S.F.

2009-01-01

Most of the great California-Nevada heat waves can be classified into primarily daytime or nighttime events depending on whether atmospheric conditions are dry or humid. A rash of nighttime-accentuated events in the last decade was punctuated by an unusually intense case in July 2006, which was the largest heat wave on record (1948-2006). Generally, there is a positive trend in heat wave activity over the entire region that is expressed most strongly and clearly in nighttime rather than daytime temperature extremes. This trend in nighttime heat wave activity has intensified markedly since the 1980s and especially since 2000. The two most recent nighttime heat waves were also strongly expressed in extreme daytime temperatures. Circulations associated with great regional heat waves advect hot air into the region. This air can be dry or moist, depending on whether a moisture source is available, causing heat waves to be expressed preferentially during day or night. A remote moisture source centered within a marine region west of Baja California has been increasing in prominence because of gradual sea surface warming and a related increase in atmospheric humidity. Adding to the very strong synoptic dynamics during the 2006 heat wave were a prolonged stream of moisture from this southwestern source and, despite the heightened humidity, an environment in which afternoon convection was suppressed, keeping cloudiness low and daytime temperatures high. The relative contributions of these factors and possible relations to global warming are discussed. ?? 2009 American Meteorological Society.

Review of lower hybrid wave heating and current drive

International Nuclear Information System (INIS)

Gormezano, C.

1986-01-01

Interaction of Lower Hybrid waves and plasmas is a very versatile method which has proven to be effective in a large range of applications: bulk ion heating, bulk electron heating, non inductive current drive. If the ratio between the mean velocity of HF induced fast particles and the thermal velocity of the bulk population is relatively small, effective bulk ion heating or bulk electron heating can occur via collisional transfer. If the above ratio is too large, fast ions, which have mainly a perpendicular energy, are poorly confined. Moreover they can be harmful for the discharge (impurities, etc...) since they are lost on the walls. In contrast, HF induced fast electrons gain essentially a parallel momentum from the wave. If unidirectional waves are launched, the dissymetry in electron distribution result in the obtention of an effective non inductive current

An energy and mortality impact assessment of the urban heat island in the US

International Nuclear Information System (INIS)

Lowe, Scott A.

2016-01-01

Increased summer energy use and increased summer heat related mortality are the two most cited detrimental impacts of the urban heat island (UHI). An assessment of these impacts was made that considered the annual impact of the UHI, not just the summer impact. It was found that in north of the US there was a net decrease in energy use from the UHI, as heating energy reductions were larger than the increase in cooling energy. In the south there was a net energy increase from the UHI. The impact of the UHI on heat related deaths was an estimated increase of 1.1 deaths per million people. The impact of the UHI on cold related deaths was an estimated decrease of 4.0 deaths per million people. These estimates are caveated by the acknowledgement that compounding factors influence mortality. Hypothermia related death rates were three times higher in rural areas than urban areas. This is surprising as the homeless population is usually considered the most at risk, yet they mostly live in urban areas. - Highlights: • The urban heat island (UHI) may actually be beneficial in colder cities in the US in terms of energy use • The UHI may cause an increase in heat related mortality of ~ 1 deaths per million • In winter the UHI may decrease cold related mortality by ~ 4 deaths per million • Cold related death rates were 3 times higher in rural areas although the homeless population live mainly in urban areas

An energy and mortality impact assessment of the urban heat island in the US

Energy Technology Data Exchange (ETDEWEB)

Lowe, Scott A., E-mail: Scott.lowe@manhattan.edu

2016-01-15

Increased summer energy use and increased summer heat related mortality are the two most cited detrimental impacts of the urban heat island (UHI). An assessment of these impacts was made that considered the annual impact of the UHI, not just the summer impact. It was found that in north of the US there was a net decrease in energy use from the UHI, as heating energy reductions were larger than the increase in cooling energy. In the south there was a net energy increase from the UHI. The impact of the UHI on heat related deaths was an estimated increase of 1.1 deaths per million people. The impact of the UHI on cold related deaths was an estimated decrease of 4.0 deaths per million people. These estimates are caveated by the acknowledgement that compounding factors influence mortality. Hypothermia related death rates were three times higher in rural areas than urban areas. This is surprising as the homeless population is usually considered the most at risk, yet they mostly live in urban areas. - Highlights: • The urban heat island (UHI) may actually be beneficial in colder cities in the US in terms of energy use • The UHI may cause an increase in heat related mortality of ~ 1 deaths per million • In winter the UHI may decrease cold related mortality by ~ 4 deaths per million • Cold related death rates were 3 times higher in rural areas although the homeless population live mainly in urban areas.

A Cross-Sectional Study of Heat Wave-Related Knowledge, Attitude, and Practice among the Public in the Licheng District of Jinan City, China.

Science.gov (United States)

Li, Jing; Xu, Xin; Ding, Guoyong; Zhao, Yun; Zhao, Ruixia; Xue, Fuzhong; Li, Jing; Gao, Jinghong; Yang, Jun; Jiang, Baofa; Liu, Qiyong

2016-06-29

Knowledge, attitude, and practice (KAP) are three key components for reducing the adverse health impacts of heat waves. However, research in eastern China regarding this is scarce. The present study aimed to evaluate the heat wave-related KAP of a population in Licheng in northeast China. This cross-sectional study included 2241 participants. Data regarding demographic characteristics, KAP, and heat illnesses were collected using a structured questionnaire. Univariate analysis and unconditional logistic regression models were used to analyze the data. Most residents had high KAP scores, with a mean score of 12.23 (standard deviation = 2.23) on a 17-point scale. Urban women and participants aged 35-44 years had relatively high total scores, and those with high education levels had the highest total score. There was an increased risk of heat-related illness among those with knowledge scores of 3-5 on an 8-point scale with mean score of 5.40 (standard deviation = 1.45). Having a positive attitude toward sunstroke prevention and engaging in more preventive practices to avoid heat exposure had a protective interaction effect on reducing the prevalence of heat-related illnesses. Although the KAP scores were relatively high, knowledge and practice were lacking to some extent. Therefore, governments should further develop risk-awareness strategies that increase awareness and knowledge regarding the adverse health impact of heat and help in planning response strategies to improve the ability of individuals to cope with heat waves.

A Cross-Sectional Study of Heat Wave-Related Knowledge, Attitude, and Practice among the Public in the Licheng District of Jinan City, China

Directory of Open Access Journals (Sweden)

Jing Li

2016-06-01

Full Text Available Knowledge, attitude, and practice (KAP are three key components for reducing the adverse health impacts of heat waves. However, research in eastern China regarding this is scarce. The present study aimed to evaluate the heat wave-related KAP of a population in Licheng in northeast China. This cross-sectional study included 2241 participants. Data regarding demographic characteristics, KAP, and heat illnesses were collected using a structured questionnaire. Univariate analysis and unconditional logistic regression models were used to analyze the data. Most residents had high KAP scores, with a mean score of 12.23 (standard deviation = 2.23 on a 17-point scale. Urban women and participants aged 35–44 years had relatively high total scores, and those with high education levels had the highest total score. There was an increased risk of heat-related illness among those with knowledge scores of 3–5 on an 8-point scale with mean score of 5.40 (standard deviation = 1.45. Having a positive attitude toward sunstroke prevention and engaging in more preventive practices to avoid heat exposure had a protective interaction effect on reducing the prevalence of heat-related illnesses. Although the KAP scores were relatively high, knowledge and practice were lacking to some extent. Therefore, governments should further develop risk-awareness strategies that increase awareness and knowledge regarding the adverse health impact of heat and help in planning response strategies to improve the ability of individuals to cope with heat waves.

Thermal extremes mortality risk assessment in urban areas

Directory of Open Access Journals (Sweden)

Paulo Canário

2010-06-01

Full Text Available The impact of heat waves on mortality has been the subject of numerous studies and the focus of attention of various national and international governmental bodies. In the summer of 2003 alone, which was exceptionally hot, the number of deaths in 12 European countries increased by 70,000. The overall trend of warming will lead to an increase in frequency, duration and intensity of heat waves and to an increase in heat related mortality. The need to assess the risk of death due to extreme heat, at a detailed spatial scale, has determined the implementation of a research project based on a general model of risk for potentially destructive natural phenomena; the model uses the relationship between hazard and vulnerability and was designed primarily for urban areas. The major hazardous meteorological variables are those that determine the thermal complex (air temperature, radiative temperature, wind and humidity and the variables related to air quality (mainly ozone and Particulate matter. Vulnerability takes into account the population sensitivity (at various spatial scales and their exposure to thermal extremes.

Future heat waves due to climate change threaten the survival of Posidonia oceanica seedlings.

Science.gov (United States)

Guerrero-Meseguer, Laura; Marín, Arnaldo; Sanz-Lázaro, Carlos

2017-11-01

Extreme weather events are major drivers of ecological change, and their occurrence is likely to increase due to climate change. The transient increases in atmospheric temperatures are leading to a greater occurrence of heat waves, extreme events that can produce a substantial warming of water, especially in enclosed basins such as the Mediterranean Sea. Here, we tested the effects of current and predicted heat waves on the early stages of development of the seagrass Posidonia oceanica. Temperatures above 27 °C limited the growth of the plant by inhibiting its photosynthetic system. It suffered a reduction in leaf growth and faster leaf senescence, and in some cases mortality. This study demonstrates that the greater frequency of heat waves, along with anticipated temperature rises in coming decades, are expected to negatively affect the germination of P. oceanica seedlings. Copyright © 2017 Elsevier Ltd. All rights reserved.

Spatial patterns of heat-related cardiovascular mortality in the Czech Republic

Czech Academy of Sciences Publication Activity Database

Urban, Aleš; Burkart, K.; Kyselý, Jan; Schuster, Ch.; Plavcová, Eva; Hanzlíková, Hana; Štěpánek, Petr; Lakes, T.

2016-01-01

Roč. 13, č. 3 (2016), č. článku 284. ISSN 1660-4601 R&D Projects: GA ČR(CZ) GAP209/11/1985 Institutional support: RVO:68378289 ; RVO:67179843 Keywords : heat stress * mortality * socioeconomic status * spatial differences * cardiovascular disease Subject RIV: DG - Athmosphere Sciences, Meteorology; DG - Athmosphere Sciences, Meteorology (UEK-B) Impact factor: 2.101, year: 2016 http://www.mdpi.com/1660-4601/13/3/284

Climate change scenarios of heat waves in Central Europe and their uncertainties

Science.gov (United States)

Lhotka, Ondřej; Kyselý, Jan; Farda, Aleš

2018-02-01

The study examines climate change scenarios of Central European heat waves with a focus on related uncertainties in a large ensemble of regional climate model (RCM) simulations from the EURO-CORDEX and ENSEMBLES projects. Historical runs (1970-1999) driven by global climate models (GCMs) are evaluated against the E-OBS gridded data set in the first step. Although the RCMs are found to reproduce the frequency of heat waves quite well, those RCMs with the coarser grid (25 and 50 km) considerably overestimate the frequency of severe heat waves. This deficiency is improved in higher-resolution (12.5 km) EURO-CORDEX RCMs. In the near future (2020-2049), heat waves are projected to be nearly twice as frequent in comparison to the modelled historical period, and the increase is even larger for severe heat waves. Uncertainty originates mainly from the selection of RCMs and GCMs because the increase is similar for all concentration scenarios. For the late twenty-first century (2070-2099), a substantial increase in heat wave frequencies is projected, the magnitude of which depends mainly upon concentration scenario. Three to four heat waves per summer are projected in this period (compared to less than one in the recent climate), and severe heat waves are likely to become a regular phenomenon. This increment is primarily driven by a positive shift of temperature distribution, but changes in its scale and enhanced temporal autocorrelation of temperature also contribute to the projected increase in heat wave frequencies.

Extreme heat waves under 1.5 °C and 2 °C global warming

Science.gov (United States)

Dosio, Alessandro; Mentaschi, Lorenzo; Fischer, Erich M.; Wyser, Klaus

2018-05-01

Severe, extreme, and exceptional heat waves, such as those that occurred over the Balkans (2007), France (2003), or Russia (2010), are associated with increased mortality, human discomfort and reduced labour productivity. Based on the results of a very high-resolution global model, we show that, even at 1.5 °C warming, a significant increase in heat wave magnitude is expected over Africa, South America, and Southeast Asia. Compared to a 1.5 °C world, under 2 °C warming the frequency of extreme heat waves would double over most of the globe. In a 1.5 °C world, 13.8% of the world population will be exposed to severe heat waves at least once every 5 years. This fraction becomes nearly three times larger (36.9%) under 2 °C warming, i.e. a difference of around 1.7 billion people. Limiting global warming to 1.5 °C will also result in around 420 million fewer people being frequently exposed to extreme heat waves, and ~65 million to exceptional heat waves. Nearly 700 million people (9.0% of world population) will be exposed to extreme heat waves at least once every 20 years in a 1.5 °C world, but more than 2 billion people (28.2%) in a 2 °C world. With current emission trends threatening even the 2 °C target, our study is helpful to identify regions where limiting the warming to 1.5 °C would have the strongest benefits in reducing population exposure to extreme heat.

Warm vegetarians? Heat waves and diet shifts in tadpoles.

Science.gov (United States)

Carreira, B M; Segurado, P; Orizaola, G; Gonçalves, N; Pinto, V; Laurila, A; Rebelo, R

2016-11-01

Temperature can play an important role in determining the feeding preferences of ectotherms. In light of the warmer temperatures arising with the current climatic changes, omnivorous ectotherms may perform diet shifts toward higher herbivory to optimize energetic intake. Such diet shifts may also occur during heat waves, which are projected to become more frequent, intense, and longer lasting in the future. Here, we investigated how heat waves of different duration affect feeding preferences in omnivorous anuran tadpoles and how these choices affect larval life history. In laboratory experiments, we fed tadpoles of three species on animal, plant, or mixed diet and exposed them to short heat waves (similar to the heat waves these species experience currently) or long heat waves (predicted to increase under climate change). We estimated the dietary choices of tadpoles fed on the mixed diet using stable isotopes and recorded tadpole survival and growth, larval period, and mass at metamorphosis. Tadpole feeding preferences were associated with their thermal background, with herbivory increasing with breeding temperature in nature. Patterns in survival, growth, and development generally support decreased efficiency of carnivorous diets and increased efficiency or higher relative quality of herbivorous diets at higher temperatures. All three species increased herbivory in at least one of the heat wave treatments, but the responses varied among species. Diet shifts toward higher herbivory were maladaptive in one species, but beneficial in the other two. Higher herbivory in omnivorous ectotherms under warmer temperatures may impact species differently and further contribute to changes in the structure and function of freshwater environments. © 2016 by the Ecological Society of America.

More Intense Mega Heat Waves in the Warmer World

Science.gov (United States)

Choi, G.; Robinson, D. A.

2017-12-01

In this study, changes in the occurrences of heat waves on the globe since the mid- 20th century and the synoptic characteristics of mega heat waves at regional scales in the warmer climate are examined. The NCEP-NCAR reanalysis surface data show that there have been no obvious linear changes in the heat wave frequencies at the continental scales since the mid-20th century, but amplified interdecadal variations led to unprecedented intense heat waves in the recent decades at the regional scales. Such mega heat waves have been more frequently observed in the poleward subtropical climate belts as well as in the interior region of continents. According to the analyses of upper tropospheric data, the occurrences of more intense mega heat waves since the late 20th century may be associated with the expansion of subtropical high pressures. These results suggest that populous cities near the subtropical climate zones should provide proactive mega heat wave warning systems for residents due to their vulnerability to the sudden attack of human lives harvest by mega heat waves in the warmer 21st century.

Probability of US Heat Waves Affected by a Subseasonal Planetary Wave Pattern

Science.gov (United States)

Teng, Haiyan; Branstator, Grant; Wang, Hailan; Meehl, Gerald A.; Washington, Warren M.

2013-01-01

Heat waves are thought to result from subseasonal atmospheric variability. Atmospheric phenomena driven by tropical convection, such as the Asian monsoon, have been considered potential sources of predictability on subseasonal timescales. Mid-latitude atmospheric dynamics have been considered too chaotic to allow significant prediction skill of lead times beyond the typical 10-day range of weather forecasts. Here we use a 12,000-year integration of an atmospheric general circulation model to identify a pattern of subseasonal atmospheric variability that can help improve forecast skill for heat waves in the United States. We find that heat waves tend to be preceded by 15-20 days by a pattern of anomalous atmospheric planetary waves with a wavenumber of 5. This circulation pattern can arise as a result of internal atmospheric dynamics and is not necessarily linked to tropical heating.We conclude that some mid-latitude circulation anomalies that increase the probability of heat waves are predictable beyond the typical weather forecast range.

Heat waves according to warm spell duration index in Slovakia during 1901-2016

Science.gov (United States)

Bochníček, Oliver; Faško, Pavel; Markovič, Ladislav

2017-04-01

A heat wave is a prolonged period of extremely high temperatures for a particular region. However, there exist no universal definitions for a heat wave as it is relative to a specific area and to a certain time of year. In fact, average temperatures in one region may be considered heat wave conditions in another. For instance, an average day in the Mediterranean would be regarded as heat wave conditions in Northern Europe. We have known that World Meteorological Organization definition of a heatwave which is "when the daily maximum temperature of more than five consecutive days exceeds the average maximum temperature by 5 °C, the normal period being 1961-1990". This rule has been accepted in contribution Heat waves and warm periods in Slovakia (Oliver Bochníček - Pavol Fa\\vsko - Ladislav Markovič) published (presented) in EGU 2016. To move on we have tried another criterion for heat waves evaluation (according to warm spell duration index, WSDI) and period since 1901 (1951) to 2016. Important for many sectors (hydrology, agriculture, transportation and tourism) is, that heat waves have been expected during the whole year and period, that is why it can have various impacts. Heat waves occurrence gave us interesting results especially after the 1990.

Relationship between heat index and mortality of 6 major cities in Taiwan.

Science.gov (United States)

Sung, Tzu-I; Wu, Pei-Chih; Lung, Shih-Chun; Lin, Chuan-Yao; Chen, Mu-Jean; Su, Huey-Jen

2013-01-01

Increased mortality, linked to events of extreme high temperatures, is recognized as one critical challenge to the public health sector. Therefore, this ecological study was conducted to assess whether this association is also significant in Taiwan and the characteristics of the relationship. Daily mean heat indices, from 1994 through 2008, were used as the predictor for the risk of increased mortality in populations from 6 major Taiwanese cities. Daily mortality data from 1994 through 2008 were retrieved from the Taiwan Death Registry, Department of Health, Taiwan, and meteorological data were acquired from the Central Weather Bureau. Poisson regression analyses using generalized linear models were applied to estimate the temperature-mortality relationship. Daily mean heat indices were calculated and used as the temperature metric. Overall, increased risk ratios in mortality were associated with increased daily mean heat indices. Significantly increased risk ratios of daily mortality were evident when daily mean heat indices were at and above the 95th percentile, when compared to the lowest percentile, in all cities. These risks tended to increase similarly among those aged 65 years and older; a phenomenon seen in the cities of Keelung, Taipei, Taichung, Tainan, and Kaohsiung, but not Chiayi. Being more vulnerable to heat stress is likely restricted to a short-term effect, as suggested by lag models which showed that there was dominantly an association during the period of 0 to 3 days. In Taiwan, predicting city-specific daily mean heat indices may provide a useful early warning system for increased mortality risk, especially for the elderly. Regional differences in health vulnerabilities should be further examined in relation to the differential social-ecological systems that affect them. Copyright © 2012 Elsevier B.V. All rights reserved.

Anomalies of hydrological cycle components during the 2007 heat wave in Bulgaria

Science.gov (United States)

Mircheva, Biliana; Tsekov, Milen; Meyer, Ulrich; Guerova, Guergana

2017-12-01

Heat waves have large adverse social, economic and environmental effects which include increased mortality, transport restrictions and a decreased agricultural production. The estimated economic losses of the 2007 heat wave in South-east Europe exceed 2 billion EUR with 19 000 hospitalisation in Romania only. Understanding the changes of the hydrological cycle components is essential for early forecasting of heat wave occurrence. Valuable insight of two components of the hydrological cycle, namely Integrated Water Vapour (IWV) and Terrestrial Water Storage Anomaly (TWSA), is now possible using observations from Global Navigation Satellite System (GNSS) and Gravity Recovery And Climate Experiment (GRACE) mission. In this study anomalies of temperature, precipitation, IWV and TWS in 2007 are compared to 2003-2013 period for Sofia, Bulgaria. In 2007, positive temperature anomalies are observed in January, February and July. There are negative IWV and precipitation anomalies in July 2007 that coincides with the heat wave in Bulgaria. TWSA in 2007 are negative in January, May and from July to October being largest in August. Long-term trends of: 1) temperatures have a local maximum in March 2007, 2) TWSA has a local minimum in May 2007, 3) IWV has a local minimum in September 2007, and 4) precipitation has a local maximum in July 2007. The TWSA interannual trends in Bulgaria, Hungary and Poland show similar behaviour as indicated by cross correlation coefficients of 0.9 and 0.7 between Bulgaria and Hungary and Bulgaria and Poland respectively. ALADIN-Climate describes the anomalies of temperature and IWV more successfully than those of precipitation and TWS.

Aging Will Amplify the Heat-related Mortality Risk under a Changing Climate: Projection for the Elderly in Beijing, China

Science.gov (United States)

Li, Tiantian; Horton, Radley M.; Bader, Daniel A.; Zhou, Maigeng; Liang, Xudong; Ban, Jie; Sun, Qinghua; Kinney, Patrick L.

2016-06-01

An aging population could substantially enhance the burden of heat-related health risks in a warming climate because of their higher susceptibility to extreme heat health effects. Here, we project heat-related mortality for adults 65 years and older in Beijing China across 31 downscaled climate models and 2 representative concentration pathways (RCPs) in the 2020s, 2050s, and 2080s. Under a scenario of medium population and RCP8.5, by the 2080s, Beijing is projected to experience 14,401 heat-related deaths per year for elderly individuals, which is a 264.9% increase compared with the 1980s. These impacts could be moderated through adaptation. In the 2080s, even with the 30% and 50% adaptation rate assumed in our study, the increase in heat-related death is approximately 7.4 times and 1.3 times larger than in the 1980s respectively under a scenario of high population and RCP8.5. These findings could assist countries in establishing public health intervention policies for the dual problems of climate change and aging population. Examples could include ensuring facilities with large elderly populations are protected from extreme heat (for example through back-up power supplies and/or passive cooling) and using databases and community networks to ensure the home-bound elderly are safe during extreme heat events.

Heat stress and public health: a critical review.

Science.gov (United States)

Kovats, R Sari; Hajat, Shakoor

2008-01-01

Heat is an environmental and occupational hazard. The prevention of deaths in the community caused by extreme high temperatures (heat waves) is now an issue of public health concern. The risk of heat-related mortality increases with natural aging, but persons with particular social and/or physical vulnerability are also at risk. Important differences in vulnerability exist between populations, depending on climate, culture, infrastructure (housing), and other factors. Public health measures include health promotion and heat wave warning systems, but the effectiveness of acute measures in response to heat waves has not yet been formally evaluated. Climate change will increase the frequency and the intensity of heat waves, and a range of measures, including improvements to housing, management of chronic diseases, and institutional care of the elderly and the vulnerable, will need to be developed to reduce health impacts.

Linking Excessive Heat with Daily Heat-Related Mortality over the Coterminous United States

Science.gov (United States)

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

2014-01-01

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) 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

The influence of multiple ion species on Alfven wave dispersion and Alfven wave plasma heating

International Nuclear Information System (INIS)

Elfimov, A.G.; Tataronis, J.A.; Hershkowitz, N.

1994-01-01

In this paper, the effects of light impurities, such as deuterium, helium, or carbon, on Alfven wave dispersion characteristics are explored. It is shown that a small population of light impurities in a hydrogen plasma modify the dispersion of the global Alfven waves and the Alfven continuum in such a way that the wave frequency depends weakly on the toroidal wave number. It is also shown that the global Alfven wave enters into the Alfven continuum. Under these conditions, it is possible to heat plasma efficiently by employing an antenna with a broad toroidal wavelength spectrum. The relationship between impurity concentration and the efficiency of Alfven wave heating is explored. Under appropriate conditions, the results indicate that in the presence of impurities, Alfven waves can heat electrons predominantly in the central part of the plasma. This effect is explored via a series of numerical calculations of the heating specifically for the Phaedrus-T Alfven wave heating experiment [Phys. Fluids B 5, 2506 (1993)

Dynamical effects of vegetation on the 2003 summer heat waves

Science.gov (United States)

Stéfanon, M.

2012-04-01

dynamics of the terrestrial biosphere are simulated by the STOMATE module. STOMATE essentially simulates processes as photosynthesis, carbon allocation, litter decomposition, soil carbon dynamics, maintenance and growth respiration, and phenology. Finally, the long-term processes, including vegetation dynamics, fire, sapling establishment, light competition, and tree mortality are simulated according to the global vegetation model LPJ. Two MORCE simulations are performed at 15-km grid resolution, driven by ERA-INTERIM for 2002-2003. The first, called CTL, was conducted using an LAI prescribed after that of year 2002. The second simulation called MORCE, uses LAI explicitly calculated. These simulations are inter-compared to provide an estimate of the dynamical vegetation contribution to the two distinct heat wave during the summer 2003.

Risk perception of heat waves and its spatial variation in Nanjing, China

Science.gov (United States)

Huang, Lei; Yang, Qianqi; Li, Jie; Chen, Jin; He, Ruoying; Zhang, Can; Chen, Kai; Dong, Steven Guanpeng; Liu, Yang

2018-05-01

The intensity, frequency, and duration of heat waves are expected to increase with climate change. In this study, we found a significant difference of public perceived effects of heat waves and trust in government among urban, suburban, and rural districts. Rural residents had a significant higher effect perception than urbanites and also showed stronger willingness to have medical insurance or regular physical examinations. Meanwhile, suburban residents had the lowest trust perception in government among these three districts, which may be due to suburban districts' unique social structure and complex social issues. Besides, we assessed the relationship between the factor effect and demographic variables. The results showed that urban respondents' effect perception was significantly related to heat wave experiences. Suburban respondents' effect perception was significantly related to age, income, and heat wave experiences. And rural respondents' effect perception was significantly related to income and chronic diseases. Based on our results, much more attention needs to be paid to rural districts. The government should strengthen infrastructure construction such as cooling centers, improve emergency response plans and mechanisms, and increase reserves of emergency supplies in rural districts. Also, targeted risk communication is of the equal importance to aid the policy-makers improving the relationship with the public and regaining the public's trust and support.

Risk perception of heat waves and its spatial variation in Nanjing, China

Science.gov (United States)

Huang, Lei; Yang, Qianqi; Li, Jie; Chen, Jin; He, Ruoying; Zhang, Can; Chen, Kai; Dong, Steven Guanpeng; Liu, Yang

2017-12-01

The intensity, frequency, and duration of heat waves are expected to increase with climate change. In this study, we found a significant difference of public perceived effects of heat waves and trust in government among urban, suburban, and rural districts. Rural residents had a significant higher effect perception than urbanites and also showed stronger willingness to have medical insurance or regular physical examinations. Meanwhile, suburban residents had the lowest trust perception in government among these three districts, which may be due to suburban districts' unique social structure and complex social issues. Besides, we assessed the relationship between the factor effect and demographic variables. The results showed that urban respondents' effect perception was significantly related to heat wave experiences. Suburban respondents' effect perception was significantly related to age, income, and heat wave experiences. And rural respondents' effect perception was significantly related to income and chronic diseases. Based on our results, much more attention needs to be paid to rural districts. The government should strengthen infrastructure construction such as cooling centers, improve emergency response plans and mechanisms, and increase reserves of emergency supplies in rural districts. Also, targeted risk communication is of the equal importance to aid the policy-makers improving the relationship with the public and regaining the public's trust and support.

Contrasting Heat Budget Dynamics During Two La Niña Marine Heat Wave Events Along Northwestern Australia

Science.gov (United States)

Xu, Jiangtao; Lowe, Ryan J.; Ivey, Gregory N.; Jones, Nicole L.; Zhang, Zhenling

2018-02-01

Two marine heat wave events along Western Australia (WA) during the alternate austral summer periods of 2010/2011 and 2012/2013, both linked to La Niña conditions, severely impacted marine ecosystems over more than 12° of latitude, which included the unprecedented bleaching of many coral reefs. Although these two heat waves were forced by similar large-scale climate drivers, the warming patterns differed substantially between events. The central coast of WA (south of 22°S) experienced greater warming in 2010/2011, whereas the northwestern coast of WA experienced greater warming in 2012/2013. To investigate how oceanic and atmospheric heat exchange processes drove these different spatial patterns, an analysis of the ocean heat budget was conducted by integrating remote sensing observations, in situ mooring data, and a high-resolution (˜1 km) ocean circulation model (Regional Ocean Modeling System). The results revealed substantial spatial differences in the relative contributions made by heat advection and air-sea heat exchange between the two heat wave events. During 2010/2011, anomalous warming driven by heat advection was present throughout the region but was much stronger south of 22°S where the poleward-flowing Leeuwin Current strengthens. During 2012/2013, air-sea heat exchange had a much more positive (warming) influence on sea surface temperatures (especially in the northwest), and when combined with a more positive contribution of heat advection in the north, this can explain the regional differences in warming between these two La Niña-associated marine heat wave events.

Quantification and assessment of heat and cold waves in Novi Sad, Northern Serbia

Science.gov (United States)

Basarin, Biljana; Lukić, Tin; Matzarakis, Andreas

2016-01-01

Physiologically equivalent temperature (PET) has been applied to the analysis of heat and cold waves and human thermal conditions in Novi Sad, Serbia. A series of daily minimum and maximum air temperature, relative humidity, wind, and cloud cover was used to calculate PET for the investigated period 1949-2012. The heat and cold wave analysis was carried out on days with PET values exceeding defined thresholds. Additionally, the acclimatization approach was introduced to evaluate human adaptation to interannual thermal perception. Trend analysis has revealed the presence of increasing trend in summer PET anomalies, number of days above defined threshold, number of heat waves, and average duration of heat waves per year since 1981. Moreover, winter PET anomaly as well as the number of days below certain threshold and number of cold waves per year until 1980 was decreasing, but the decrease was not statistically significant. The highest number of heat waves during summer was registered in the last two decades, but also in the first decade of the investigated period. On the other hand, the number of cold waves during six decades is quite similar and the differences are very small.

Impact of wave phase jumps on stochastic heating

International Nuclear Information System (INIS)

Zasenko, V.I.; Zagorodny, A.G.; Cherniak, O.M.

2016-01-01

Interaction of charged particles with fields of random waves brings about known effects of stochastic acceleration and heating. Jumps of wave phases can increase the intensity of these processes substantially. Numerical simulation of particle heating and acceleration by waves with regular phases, waves with jumping phase and stochastic electric field impulses is performed. Comparison of the results shows that to some extent an impact of phase jumps is similar to the action of separate field impulses. Jumps of phase not only increase the intensity of resonant particle heating but involves in this process non-resonant particles from a wide range of initial velocities

Temporal variation in the effect of heat and the role of the Italian heat prevention plan.

Science.gov (United States)

de'Donato, F; Scortichini, M; De Sario, M; de Martino, A; Michelozzi, P

2018-05-08

The aim of the article is to evaluate the temporal change in the effect of heat on mortality in Italy in the last 12 years after the introduction of the national heat plan. Time series analysis. Distributed lag non-linear models were used to estimate the association between maximum apparent temperature and mortality in 23 Italian cities included in the national heat plan in four study periods (before the introduction of the heat plan and three periods after the plan was in place between 2005 and 2016). The effect (relative risks) and impact (attributable fraction [AF] and number of heat-related deaths) were estimated for mild summer temperatures (20th and 75th percentile maximum apparent temperature [Tappmax]) and extreme summer temperatures (75th and 99th percentile Tappmax) in each study period. A survey of the heat preventive measures adopted over time in the cities included in the Italian heat plan was carried out to better describe adaptation measures and response. Although heat still has an impact on mortality in Italian cities, a reduction in heat-related mortality is observed progressively over time. In terms of the impact, the heat AF related to extreme temperatures declined from 6.3% in the period 1999-2002 to 4.1% in 2013-2016. Considering the entire temperature range (20th vs 99th percentile), the total number of heat-related deaths spared over the entire study period was 1900. Considering future climate change and the health burden associated to heat waves, it is important to promote adaptation measures by showing the potential effectiveness of heat prevention plans. Copyright © 2018 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Heat waves over Central Europe in regional climate model simulations

Science.gov (United States)

Lhotka, Ondřej; Kyselý, Jan

2014-05-01

Regional climate models (RCMs) have become a powerful tool for exploring impacts of global climate change on a regional scale. The aim of the study is to evaluate the capability of RCMs to reproduce characteristics of major heat waves over Central Europe in their simulations of the recent climate (1961-2000), with a focus on the most severe and longest Central European heat wave that occurred in 1994. We analyzed 7 RCM simulations with a high resolution (0.22°) from the ENSEMBLES project, driven by the ERA-40 reanalysis. In observed data (the E-OBS 9.0 dataset), heat waves were defined on the basis of deviations of daily maximum temperature (Tmax) from the 95% quantile of summer Tmax distribution in grid points over Central Europe. The same methodology was applied in the RCM simulations; we used corresponding 95% quantiles (calculated for each RCM and grid point) in order to remove the bias of modelled Tmax. While climatological characteristics of heat waves are reproduced reasonably well in the RCM ensemble, we found major deficiencies in simulating heat waves in individual years. For example, METNOHIRHAM simulated very severe heat waves in 1996, when no heat wave was observed. Focusing on the major 1994 heat wave, considerable differences in simulated temperature patterns were found among the RCMs. The differences in the temperature patterns were clearly linked to the simulated amount of precipitation during this event. The 1994 heat wave was almost absent in all RCMs that did not capture the observed precipitation deficit, while it was by far most pronounced in KNMI-RACMO that simulated virtually no precipitation over Central Europe during the 15-day period of the heat wave. By contrast to precipitation, values of evaporative fraction in the RCMs were not linked to severity of the simulated 1994 heat wave. This suggests a possible major contribution of other factors such as cloud cover and associated downward shortwave radiation. Therefore, a more detailed

Projection of Heat Waves over China under Different Global Warming Targets

Science.gov (United States)

Guo, Xiaojun; Luo, Yong; Huang, Jianbin; Zhao, Zongci

2015-04-01

Global warming targets, which are determined in terms of global mean temperature increases relative to pre-industrial temperature levels, have been one of the heated issues recently. And the climate change (especially climate extremes) and its impacts under different targets have been paid extensive concerns. In this study, evaluation and projection of heat waves in China were carried out by five CMIP5 global climate models (GCMs) with a 0.5°×0.5° horizontal resolution which were derived from EU WATCH project. A new daily observed gridded dataset CN05.1 (0.5°×0.5°) was also used to evaluate the GCMs. And four indices (heat waves frequency, longest heat waves duration, heat waves days and high temperature days) were adopted to analyze the heat waves. Compared with the observations, the five GCMs and its Multi-Model Ensemble (MME) have a remarkable capacity of reproducing the spatial and temporal characteristic of heat waves. The time correlation coefficients between MME and the observation results can all reach 0.05 significant levels. Based on the projection data of five GCMs, both the median year of crossing 1.5°C, 2°C, 2.5°, 3°C, 3.5°C, 4°C, 4.5°C and 5°C global warming targets and the corresponding climate change over China were analyzed under RCP 4.5 and RCP 8.5 scenarios, respectively. The results show that when the global mean surface air temperature rise to different targets with respect to the pre-industrial times (1861-1880), the frequency and intensity of heat waves will increase dramatically. To take the high emission scenario RCP8.5 as an example, under the RCP8.5 scenario, the warming rate over China is stronger than that over the globe, the temperature rise(median year) over China projected by MME are 1.77°C(2025), 2.63°C(2039), 3.39°C(2050), 3.97°C(2060), 4.82°C(2070), 5.47°C(2079) and 6.2°C(2089) under 1.5°C, 2°C, 2.5°C, 3°C, 3.5°C, 4°C and 4.5°C global warming targets, respectively. With the increase of the global

Aging Will Amplify the Heat-Related Mortality Risk Under a Changing Climate: Projection for the Elderly in Beijing, China

Science.gov (United States)

Li, Tiantian; Horton, Radley M.; Bader, Daniel A.; Zhou, Maigeng; Liang, Xudong; Ban, Jie; Sun, Qinghua; Kinney, Patrick L.

2016-01-01

An aging population could substantially enhance the burden of heat-related health risks in a warming climate because of their higher susceptibility to extreme heat health effects. Here, we project heatrelated mortality for adults 65 years and older in Beijing China across 31 downscaled climate models and 2 representative concentration pathways (RCPs) in the 2020s, 2050s, and 2080s. Under a scenario of medium population and RCP8.5, by the 2080s, Beijing is projected to experience 14,401 heat-related deaths per year for elderly individuals, which is a 264.9% increase compared with the 1980s. These impacts could be moderated through adaptation. In the 2080s, even with the 30% and 50% adaptation rate assumed in our study, the increase in heat-related death is approximately 7.4 times and 1.3 times larger than in the 1980s respectively under a scenario of high population and RCP8.5. These findings could assist countries in establishing public health intervention policies for the dual problems of climate change and aging population. Examples could include ensuring facilities with large elderly populations are protected from extreme heat (for example through back-up power supplies and/or passive cooling) and using databases and community networks to ensure the home-bound elderly are safe during extreme heat events.

Effects of Simulated Heat Waves on Cardiovascular Functions in Senile Mice

Directory of Open Access Journals (Sweden)

Xiakun Zhang

2014-08-01

Full Text Available The mechanism of the effects of simulated heat waves on cardiovascular disease in senile mice was investigated. Heat waves were simulated in a TEM1880 meteorological environment simulation chamber, according to a heat wave that occurred in July 2001 in Nanjing, China. Eighteen senile mice were divided into control, heat wave, and heat wave BH4 groups, respectively. Mice in the heat wave and heat wave BH4 groups were exposed to simulated heat waves in the simulation chamber. The levels of ET-1, NO, HSP60, SOD, TNF, sICAM-1, and HIF-1α in each group of mice were measured after heat wave simulation. Results show that heat waves decreased SOD activity in the myocardial tissue of senile mice, increased NO, HSP60, TNF, sICAM-1, and HIF-1α levels, and slightly decreased ET-1 levels, BH4 can relieve the effects of heat waves on various biological indicators. After a comprehensive analysis of the experiments above, we draw the followings conclusions regarding the influence of heat waves on senile mice: excess HSP60 activated immune cells, and induced endothelial cells and macrophages to secrete large amounts of ICAM-1, TNF-α, and other inflammatory cytokines, it also activated the inflammation response in the body and damaged the coronary endothelial cell structure, which increased the permeability of blood vessel intima and decreased SOD activity in cardiac tissues. The oxidation of lipoproteins in the blood increased, and large amounts of cholesterol were generated. Cholesterol penetrated the intima and deposited on the blood vessel wall, forming atherosclerosis and leading to the occurrence of cardiovascular disease in senile mice. These results maybe are useful for studying the effects of heat waves on elderly humans, which we discussed in the discussion chapter.

Contributions to the stability analysis of self-similar supersonic heat waves related to inertial confinement fusion

International Nuclear Information System (INIS)

Dastugue, Laurent

2013-01-01

Exact self-similar solutions of gas dynamics equations with nonlinear heat conduction for semi-infinite slabs of perfect gases are used for studying the stability of flows in inertial confinement fusion. Both the similarity solutions and their linear perturbations are computed with a multi domain Chebyshev pseudo-spectral method, allowing us to account for, without any other approximation, compressibility and unsteadiness. Following previous results (Clarisse et al., 2008; Lombard, 2008) representative of the early ablation of a target by a nonuniform laser flux (electronic conduction, subsonic heat front downstream of a quasi-perfect shock front), we explore here other configurations. For this early ablation phase, but for a nonuniform incident X-radiation (radiative conduction), we study a compressible and a weakly compressible flow. In both cases, we recover the behaviours obtained for compressible flows with electronic heat conduction with a maximal instability for a zero wavenumber. Besides, the spectral method is extended to compute similarity solutions taking into account the supersonic heat wave ahead of the shock front. Based on an analysis of the reduced equations singularities (infinitely stiff front), this method allows us to describe the supersonic heat wave regime proper to the initial irradiation of the target and to recover the ablative solutions which were obtained under a negligible fore-running heat wave approximation. (author) [fr

CLOSED-FIELD CORONAL HEATING DRIVEN BY WAVE TURBULENCE

Energy Technology Data Exchange (ETDEWEB)

Downs, Cooper; Lionello, Roberto; Mikić, Zoran; Linker, Jon A [Predictive Science Incorporated, 9990 Mesa Rim Rd. Suite 170, San Diego, CA 92121 (United States); Velli, Marco, E-mail: cdowns@predsci.com [EPSS, UCLA, Los Angeles, CA 90095 (United States)

2016-12-01

To simulate the energy balance of coronal plasmas on macroscopic scales, we often require the specification of the coronal heating mechanism in some functional form. To go beyond empirical formulations and to build a more physically motivated heating function, we investigate the wave-turbulence-driven (WTD) phenomenology for the heating of closed coronal loops. Our implementation is designed to capture the large-scale propagation, reflection, and dissipation of wave turbulence along a loop. The parameter space of this model is explored by solving the coupled WTD and hydrodynamic evolution in 1D for an idealized loop. The relevance to a range of solar conditions is also established by computing solutions for over one hundred loops extracted from a realistic 3D coronal field. Due to the implicit dependence of the WTD heating model on loop geometry and plasma properties along the loop and at the footpoints, we find that this model can significantly reduce the number of free parameters when compared to traditional empirical heating models, and still robustly describe a broad range of quiet-Sun and active region conditions. The importance of the self-reflection term in producing relatively short heating scale heights and thermal nonequilibrium cycles is also discussed.

Temperature Variation and Heat Wave and Cold Spell Impacts on Years of Life Lost Among the Urban Poor Population of Nairobi, Kenya

Directory of Open Access Journals (Sweden)

Thaddaeus Egondi

2015-03-01

Full Text Available Weather extremes are associated with adverse health outcomes, including mortality. Studies have investigated the mortality risk of temperature in terms of excess mortality, however, this risk estimate may not be appealing to policy makers assessing the benefits expected for any interventions to be adopted. To provide further evidence of the burden of extreme temperatures, we analyzed the effect of temperature on years of life lost (YLL due to all-cause mortality among the population in two urban informal settlements. YLL was generated based on the life expectancy of the population during the study period by applying a survival analysis approach. Association between daily maximum temperature and YLL was assessed using a distributed lag nonlinear model. In addition, cold spell and heat wave effects, as defined according to different percentiles, were investigated. The exposure-response curve between temperature and YLL was J-shaped, with the minimum mortality temperature (MMT of 26 °C. An average temperature of 21 °C compared to the MMT was associated with an increase of 27.4 YLL per day (95% CI, 2.7–52.0 years. However, there was no additional effect for extended periods of cold spells, nor did we find significant associations between YLL to heat or heat waves. Overall, increased YLL from all-causes were associated with cold spells indicating the need for initiating measure for reducing health burdens.

Relating Alfvén Wave Heating Model to Observations of a Solar Active Region

Science.gov (United States)

Yoritomo, J. Y.; Van Ballegooijen, A. A.

2012-12-01

We compared images from the Solar Dynamics Observatory's (SDO) Atmospheric Imaging Assembly (AIA) with simulations of propagating and dissipating Alfvén waves from a three-dimensional magnetohydrodynamic (MHD) model (van Ballegooijen et. al 2011; Asgari-Targhi & van Ballegooijen 2012). The goal was to search for observational evidence of Alfvén waves in the solar corona and understand their role in coronal heating. We looked at one particular active region on the 5th of May 2012. Certain distinct loops in the SDO/AIA observations were selected and expanded. Movies were created from these selections in an attempt to discover transverse motions that may be Alfvén waves. Using a magnetogram of that day and the corresponding synoptic map, a potential field model was created for the active region. Three-dimensional MHD models for several loops in different locations in the active region were created. Each model specifies the temperature, pressure, magnetic field strength, average heating rate, and other parameters along the loop. We find that the heating is intermittent in the loops and reflection occurs at the transition region. For loops at larger and larger height, a point is reached where thermal non-equilibrium occurs. In the center this critical height is much higher than in the periphery of the active region. Lastly, we find that the average heating rate and coronal pressure decrease with increasing height in the corona. This research was supported by an NSF grant for the Smithsonian Astrophysical Observatory (SAO) Solar REU program and a SDO/AIA grant for the Smithsonian Astrophysical Observatory.

Role of soil moisture vs. recent climate change for heat waves in western Russia

Science.gov (United States)

Hauser, Mathias; Orth, Rene; Seneviratne, Sonia

2015-04-01

Using the framework of event attribution, anthropogenic climate change was found to have a discernible influence on the occurence-probability of heat waves, such as the one in Russia in 2010. Soil moisture, on the other hand, is an important physical driver for heat waves as its availability has a large influence on the partitioning of the available surface net radiation into latent and sensible heat flux. The presented study investigates the relative importance of both controls, soil moisture and increasing greenhouse gas concentrations, on heat waves in the region of the 2010 Russian heat wave. This is done with a large number of ensemble members from climate simulations with and without interactive soil moisture for both, the 2000s and the 1960s. The simualtions allow to determine the occurence-probability of heat waves with and without the soil moisture-temperature feedback and to compare it to the change caused by climate change. Thereby, we expect to see the largest effect on daytime maximum temperatures (TXx) and a smaller influence of soil moisture on the mean temperatures and cold extremes.

Possibilities of heating a TFR plasma by absorption of the fast hydromagnetic wave

International Nuclear Information System (INIS)

Adam, J.

The prospects of TFR heating by fast hydromagnetic waves are considered by an examination of the following topics: (1) characteristics of the dispersion relation, (2) the charge impedance of an antenna capable of exciting these modes, and (3) the heating effects which would be caused by dissipation of these waves around ω = ω/sub ci/ and ω = 2ω/sub ci/

The Impact of the Urban Heat Island during an Intense Heat Wave in Oklahoma City

Directory of Open Access Journals (Sweden)

Jeffrey B. Basara

2010-01-01

Full Text Available During late July and early August 2008, an intense heat wave occurred in Oklahoma City. To quantify the impact of the urban heat island (UHI in Oklahoma City on observed and apparent temperature conditions during the heat wave event, this study used observations from 46 locations in and around Oklahoma City. The methodology utilized composite values of atmospheric conditions for three primary categories defined by population and general land use: rural, suburban, and urban. The results of the analyses demonstrated that a consistent UHI existed during the study period whereby the composite temperature values within the urban core were approximately 0.5∘C warmer during the day than the rural areas and over 2∘C warmer at night. Further, when the warmer temperatures were combined with ambient humidity conditions, the composite values consistently revealed even warmer heat-related variables within the urban environment as compared with the rural zone.

Exploring the association between heat and mortality in Switzerland between 1995 and 2013.

Science.gov (United States)

Ragettli, Martina S; Vicedo-Cabrera, Ana M; Schindler, Christian; Röösli, Martin

2017-10-01

Designing effective public health strategies to prevent adverse health effect of hot weather is crucial in the context of global warming. In Switzerland, the 2003 heat have caused an estimated 7% increase in all-cause mortality. As a consequence, the Swiss Federal Office of Public Health developed an information campaign to raise public awareness on heat threats. For a better understanding on how hot weather affects daily mortality in Switzerland, we assessed the effect of heat on daily mortality in eight Swiss cities and population subgroups from 1995 to 2013 using different temperature metrics (daily mean (Tmean), maximum (Tmax), minimum (Tmin) and maximum apparent temperature (Tappmax)), and aimed to evaluate variations of the heat effect after 2003 (1995-2002 versus 2004-2013). We applied conditional quasi-Poisson regression models with non-linear distributed lag functions to estimate temperature-mortality associations over all cities (1995-2013) and separately for two time periods (1995-2002, 2004-2013). Relative risks (RR) of daily mortality were estimated for increases in temperature from the median to the 98th percentile of the warm season temperature distribution. Over the whole time period, significant temperature-mortality relationships were found for all temperature indicators (RR (95% confidence interval): Tappmax: 1.12 (1.05; 1.18); Tmax: 1.15 (1.08-1.22); Tmean: 1.16 (1.09-1.23); Tmin 1.23 (1.15-1.32)). Mortality risks were higher at the beginning of the summer, especially for Tmin. In the more recent time period, we observed a non-significant reduction in the effect of high temperatures on mortality, with the age group > 74 years remaining the population at highest risk. High temperatures continue to be a considerable risk factor for human health in Switzerland after 2003. More effective public health measures targeting the elderly should be promoted with increased attention to the first heat events in summer and considering both high day-time and

Climate change, heat, and mortality in the tropical urban area of San Juan, Puerto Rico

Science.gov (United States)

Méndez-Lázaro, Pablo A.; Pérez-Cardona, Cynthia M.; Rodríguez, Ernesto; Martínez, Odalys; Taboas, Mariela; Bocanegra, Arelis; Méndez-Tejeda, Rafael

2016-12-01

Extreme heat episodes are becoming more common worldwide, including in tropical areas of Australia, India, and Puerto Rico. Higher frequency, duration, and intensity of extreme heat episodes are triggering public health issues in most mid-latitude and continental cities. With urbanization, land use and land cover have affected local climate directly and indirectly encouraging the Urban Heat Island effect with potential impacts on heat-related morbidity and mortality among urban populations. However, this association is not completely understood in tropical islands such as Puerto Rico. The present study examines the effects of heat in two municipalities (San Juan and Bayamón) within the San Juan metropolitan area on overall and cause-specific mortality among the population between 2009 and 2013. The number of daily deaths attributed to selected causes (cardiovascular disease, hypertension, diabetes, stroke, chronic lower respiratory disease, pneumonia, and kidney disease) coded and classified according to the Tenth Revision of the International Classification of Diseases was analyzed. The relations between elevated air surface temperatures on cause-specific mortality were modeled. Separate Poisson regression models were fitted to explain the total number of deaths as a function of daily maximum and minimum temperatures, while adjusting for seasonal patterns. Results show a significant increase in the effect of high temperatures on mortality, during the summers of 2012 and 2013. Stroke (relative risk = 16.80, 95% CI 6.81-41.4) and cardiovascular diseases (relative risk = 16.63, 95% CI 10.47-26.42) were the primary causes of death most associated with elevated summer temperatures. Better understanding of how these heat events affect the health of the population will provide a useful tool for decision makers to address and mitigate the effects of the increasing temperatures on public health. The enhanced temperature forecast may be a crucial component in decision

Climate change, heat, and mortality in the tropical urban area of San Juan, Puerto Rico

Science.gov (United States)

Méndez-Lázaro, Pablo A.; Pérez-Cardona, Cynthia M.; Rodríguez, Ernesto; Martínez, Odalys; Taboas, Mariela; Bocanegra, Arelis; Méndez-Tejeda, Rafael

2018-05-01

Extreme heat episodes are becoming more common worldwide, including in tropical areas of Australia, India, and Puerto Rico. Higher frequency, duration, and intensity of extreme heat episodes are triggering public health issues in most mid-latitude and continental cities. With urbanization, land use and land cover have affected local climate directly and indirectly encouraging the Urban Heat Island effect with potential impacts on heat-related morbidity and mortality among urban populations. However, this association is not completely understood in tropical islands such as Puerto Rico. The present study examines the effects of heat in two municipalities (San Juan and Bayamón) within the San Juan metropolitan area on overall and cause-specific mortality among the population between 2009 and 2013. The number of daily deaths attributed to selected causes (cardiovascular disease, hypertension, diabetes, stroke, chronic lower respiratory disease, pneumonia, and kidney disease) coded and classified according to the Tenth Revision of the International Classification of Diseases was analyzed. The relations between elevated air surface temperatures on cause-specific mortality were modeled. Separate Poisson regression models were fitted to explain the total number of deaths as a function of daily maximum and minimum temperatures, while adjusting for seasonal patterns. Results show a significant increase in the effect of high temperatures on mortality, during the summers of 2012 and 2013. Stroke (relative risk = 16.80, 95% CI 6.81-41.4) and cardiovascular diseases (relative risk = 16.63, 95% CI 10.47-26.42) were the primary causes of death most associated with elevated summer temperatures. Better understanding of how these heat events affect the health of the population will provide a useful tool for decision makers to address and mitigate the effects of the increasing temperatures on public health. The enhanced temperature forecast may be a crucial component in decision

Climate change, heat, and mortality in the tropical urban area of San Juan, Puerto Rico.

Science.gov (United States)

Méndez-Lázaro, Pablo A; Pérez-Cardona, Cynthia M; Rodríguez, Ernesto; Martínez, Odalys; Taboas, Mariela; Bocanegra, Arelis; Méndez-Tejeda, Rafael

2018-05-01

Extreme heat episodes are becoming more common worldwide, including in tropical areas of Australia, India, and Puerto Rico. Higher frequency, duration, and intensity of extreme heat episodes are triggering public health issues in most mid-latitude and continental cities. With urbanization, land use and land cover have affected local climate directly and indirectly encouraging the Urban Heat Island effect with potential impacts on heat-related morbidity and mortality among urban populations. However, this association is not completely understood in tropical islands such as Puerto Rico. The present study examines the effects of heat in two municipalities (San Juan and Bayamón) within the San Juan metropolitan area on overall and cause-specific mortality among the population between 2009 and 2013. The number of daily deaths attributed to selected causes (cardiovascular disease, hypertension, diabetes, stroke, chronic lower respiratory disease, pneumonia, and kidney disease) coded and classified according to the Tenth Revision of the International Classification of Diseases was analyzed. The relations between elevated air surface temperatures on cause-specific mortality were modeled. Separate Poisson regression models were fitted to explain the total number of deaths as a function of daily maximum and minimum temperatures, while adjusting for seasonal patterns. Results show a significant increase in the effect of high temperatures on mortality, during the summers of 2012 and 2013. Stroke (relative risk = 16.80, 95% CI 6.81-41.4) and cardiovascular diseases (relative risk = 16.63, 95% CI 10.47-26.42) were the primary causes of death most associated with elevated summer temperatures. Better understanding of how these heat events affect the health of the population will provide a useful tool for decision makers to address and mitigate the effects of the increasing temperatures on public health. The enhanced temperature forecast may be a crucial component in decision

Climate and heat-related emergencies in Chicago, Illinois (2003-2006).

Science.gov (United States)

Hartz, Donna A; Golden, Jay S; Sister, Chona; Chuang, Wen-Ching; Brazel, Anthony J

2012-01-01

Extreme heat events are responsible for more deaths in the United States than floods, hurricanes and tornados combined. Yet, highly publicized events, such as the 2003 heat wave in Europe which caused in excess of 35,000 deaths, and the Chicago heat wave of 1995 that produced over 500 deaths, draw attention away from the countless thousands who, each year, fall victim to nonfatal health emergencies and illnesses directly attributed to heat. The health impact of heat waves and excessive heat are well known. Cities worldwide are seeking to better understand heat-related illnesses with respect to the specifics of climate, social demographics and spatial distributions. This information can support better preparation for heat-related emergency situations with regards to planning for response capacity and placement of emergency resources and personnel. This study deals specifically with the relationship between climate and heat-related dispatches (HRD, emergency 911 calls) in Chicago, Illinois, between 2003 and 2006. It is part of a larger, more in-depth, study that includes urban morphology and social factors that impact heat-related emergency dispatch calls in Chicago. The highest occurrences of HRD are located in the central business district, but are generally scattered across the city. Though temperature can be a very good predictor of high HRD, heat index is a better indicator. We determined temperature and heat index thresholds for high HRD. We were also able to identify a lag in HRD as well as other situations that triggered higher (or lower) HRD than would typically be generated for the temperature and humidity levels, such as early afternoon rainfall and special events.

Ionospheric heating with oblique high-frequency waves

International Nuclear Information System (INIS)

Field, E.C. Jr.; Bloom, R.M.; Kossey, P.A.

1990-01-01

This paper presents calculations of ionospheric electron temperature and density perturbations and ground-level signal changes produced by intense oblique high-frequency (HF) radio waves. The analysis takes into account focusing at caustics, the consequent Joule heating of the surrounding plasma, heat conduction, diffusion, and recombination processes, these being the effects of a powerful oblique modifying wave. It neglects whatever plasma instabilities might occur. The authors then seek effects on a secondary test wave that is propagated along the same path as the first. The calculations predict ground-level field strength reductions of several decibels in the test wave for modifying waves having effective radiated power (ERP) in the 85- to 90-dBW range. These field strength changes are similar in sign, magnitude, and location to ones measured in Soviet experiments. The location of the signal change is sensitive to the frequency and the model ionosphere assumed; so future experiments should employ the widest possible range of frequencies and propagation conditions. An ERP of 90 dBW seems to be a sort of threshold that, if exceeded, might result in substantial rather than small signal changes. The conclusions are based solely on Joule heating and subsequent refraction of waves passing through caustic regions

Effects on Public Health of Heat Waves to Improve the Urban Quality of Life

Directory of Open Access Journals (Sweden)

Vito Telesca

2018-04-01

Full Text Available Life satisfaction has been widely used in recent studies to evaluate the effect of environmental factors on individuals’ well-being. In the last few years, many studies have shown that the potential impact of climate change on cities depends on a variety of social, economic, and environmental determinants. In particular, extreme events, such as flood and heat waves, may cause more severe impacts and induce a relatively higher level of vulnerability in populations that live in urban areas. Therefore, the impact of climate change and related extreme events certainly influences the economy and quality of life in affected cities. Heat wave frequency, intensity, and duration are increasing in global and local climate change scenarios. The association between high temperatures and morbidity is well-documented, but few studies have examined the role of meteo-climatic variables on hospital admissions. This study investigates the effects of temperature, relative humidity, and barometric pressure on health by linking daily access to a Matera (Italy hospital with meteorological conditions in summer 2012. Extreme heat wave episodes that affected most of the city from 1 June to 31 August 2012 (among the selected years 2003, 2012, and 2017 were analyzed. Results were compared with heat waves from other years included in the base period (1971–2000 and the number of emergency hospital admissions on each day was considered. The meteorological data used in this study were collected from two weather stations in Matera. In order to detect correlations between the daily emergency admissions and the extreme health events, a combined methodology based on a heat wave identification technique, multivariate analysis (PCA, and regression analysis was applied. The results highlight that the role of relative humidity decreases as the severity level of heat waves increases. Moreover, the combination of temperatures and daily barometric pressure range (DPR has been

The impact of heat waves on surface urban heat island and local economy in Cluj-Napoca city, Romania

Science.gov (United States)

Herbel, Ioana; Croitoru, Adina-Eliza; Rus, Adina Viorica; Roşca, Cristina Florina; Harpa, Gabriela Victoria; Ciupertea, Antoniu-Flavius; Rus, Ionuţ

2017-07-01

The association between heat waves and the urban heat island effect can increase the impact on environment and society inducing biophysical hazards. Heat stress and their associated public health problems are among the most frequent. This paper explores the heat waves impact on surface urban heat island and on the local economy loss during three heat periods in Cluj-Napoca city in the summer of 2015. The heat wave events were identified based on daily maximum temperature, and they were divided into three classes considering the intensity threshold: moderate heat waves (daily maximum temperature exceeding the 90th percentile), severe heat waves (daily maximum temperature over the 95th percentile), and extremely severe heat waves (daily maximum temperature exceeding the 98th percentile). The minimum length of an event was of minimum three consecutive days. The surface urban heat island was detected based on land surface temperature derived from Landsat 8 thermal infrared data, while the economic impact was estimated based on data on work force structure and work productivity in Cluj-Napoca derived from the data released by Eurostat, National Bank of Romania, and National Institute of Statistics. The results indicate that the intensity and spatial extension of surface urban heat island could be governed by the magnitude of the heat wave event, but due to the low number of satellite images available, we should consider this information only as preliminary results. Thermal infrared remote sensing has proven to be a very efficient method to study surface urban heat island, due to the fact that the synoptic conditions associated with heat wave events usually favor cloud free image. The resolution of the OLI_TIRS sensor provided good results for a mid-extension city, but the low revisiting time is still a drawback. The potential economic loss was calculated for the working days during heat waves and the estimated loss reached more than 2.5 mil. EUR for each heat wave day

Reversible electron heating vs. wave-particle interactions in quasi-perpendicular shocks

Science.gov (United States)

Veltri, P.; Mangeney, A.; Scudder, J. D.

1992-01-01

The energy necessary to explain the electron heating in quasi-perpendicular collisionless shocks can be derived either from the electron acceleration in the d.c. cross shock electric potential, or by the interactions between the electrons and the waves existing in the shock. A Monte Carlo simulation has been performed to study the electron distribution function evolution through the shock structure, with and without particle diffusion on waves. This simulation has allowed us to clarify the relative importance of the two possible energy sources; in particular it has been shown that the electron parallel temperature is determined by the d.c. electromagnetic field and not by any wave-particle-induced heating. Wave particle interactions are effective in smoothing out the large gradients in phase space produced by the 'reversible' motion of the electrons, thus producing a 'cooling' of the electrons.

The Role Of Torsional Alfvén Waves in Coronal Heating

Science.gov (United States)

Antolin, P.; Shibata, K.

2010-03-01

In the context of coronal heating, among the zoo of magnetohydrodynamic (MHD) waves that exist in the solar atmosphere, Alfvén waves receive special attention. Indeed, these waves constitute an attractive heating agent due to their ability to carry over the many different layers of the solar atmosphere sufficient energy to heat and maintain a corona. However, due to their incompressible nature these waves need a mechanism such as mode conversion (leading to shock heating), phase mixing, resonant absorption, or turbulent cascade in order to heat the plasma. Furthermore, their incompressibility makes their detection in the solar atmosphere very difficult. New observations with polarimetric, spectroscopic, and imaging instruments such as those on board the Japanese satellite Hinode, or the Crisp spectropolarimeter of the Swedish Solar Telescope or the Coronal Multi-channel Polarimeter, are bringing strong evidence for the existence of energetic Alfvén waves in the solar corona. In order to assess the role of Alfvén waves in coronal heating, in this work we model a magnetic flux tube being subject to Alfvén wave heating through the mode conversion mechanism. Using a 1.5 dimensional MHD code, we carry out a parameter survey varying the magnetic flux tube geometry (length and expansion), the photospheric magnetic field, the photospheric velocity amplitudes, and the nature of the waves (monochromatic or white-noise spectrum). The regimes under which Alfvén wave heating produces hot and stable coronae are found to be rather narrow. Independently of the photospheric wave amplitude and magnetic field, a corona can be produced and maintained only for long (>80 Mm) and thick (area ratio between the photosphere and corona >500) loops. Above a critical value of the photospheric velocity amplitude (generally a few km s-1) the corona can no longer be maintained over extended periods of time and collapses due to the large momentum of the waves. These results establish several

Excess cardiovascular mortality associated with cold spells in the Czech Republic

Directory of Open Access Journals (Sweden)

Kyncl Jan

2009-01-01

Full Text Available Abstract Background The association between cardiovascular mortality and winter cold spells was evaluated in the population of the Czech Republic over 21-yr period 1986–2006. No comprehensive study on cold-related mortality in central Europe has been carried out despite the fact that cold air invasions are more frequent and severe in this region than in western and southern Europe. Methods Cold spells were defined as periods of days on which air temperature does not exceed -3.5°C. Days on which mortality was affected by epidemics of influenza/acute respiratory infections were identified and omitted from the analysis. Excess cardiovascular mortality was determined after the long-term changes and the seasonal cycle in mortality had been removed. Excess mortality during and after cold spells was examined in individual age groups and genders. Results Cold spells were associated with positive mean excess cardiovascular mortality in all age groups (25–59, 60–69, 70–79 and 80+ years and in both men and women. The relative mortality effects were most pronounced and most direct in middle-aged men (25–59 years, which contrasts with majority of studies on cold-related mortality in other regions. The estimated excess mortality during the severe cold spells in January 1987 (+274 cardiovascular deaths is comparable to that attributed to the most severe heat wave in this region in 1994. Conclusion The results show that cold stress has a considerable impact on mortality in central Europe, representing a public health threat of an importance similar to heat waves. The elevated mortality risks in men aged 25–59 years may be related to occupational exposure of large numbers of men working outdoors in winter. Early warnings and preventive measures based on weather forecast and targeted on the susceptible parts of the population may help mitigate the effects of cold spells and save lives.

Data mining to estimate broiler mortality when exposed to heat wave Mineração de dados e estimativa da mortalidade alta de frangos quando expostos a onda de calor

Directory of Open Access Journals (Sweden)

Marcos Martinez Vale

2008-01-01

Full Text Available Heat waves usually result in losses of animal production since they are exposed to thermal stress inducing an increase in mortality and consequent economical losses. Animal science and meteorological databases from the last years contain enough data in the poultry production business to allow the modeling of mortality losses due to heat wave incidence. This research analyzes a database of broiler production associated to climatic data, using data mining techniques such as attribute selection and data classification (decision tree to model the impact of heat wave incidence on broiler mortality. The temperature and humidity index (THI was used for screening environmental data. The data mining techniques allowed the development of three comprehensible models for estimating specifically high mortality during broiler production. Two models yielded a classification accuracy of 89.3% by using Principal Component Analysis (PCA and Wrapper feature selection approaches. Both models obtained a class precision of 0.83 for classifying high mortality. When the feature selection was made by the domain experts, the model accuracy reached 85.7%, while the class precision of high mortality was 0.76. Meteorological data and the calculated THI from meteorological stations were helpful to select the range of harmful environmental conditions for broilers 29 and 42 days old. The data mining techniques were useful for building animal production models.As ondas de calor provocam perdas na produção animal pela sua exposição ao estresse por calor aumentando a mortalidade, e consequentemente, perdas econômicas. Bancos de dados zootécnicos e meteorológicos históricos podem conter informações que permitem modelar a mortalidade de frangos devido à incidência de ondas de calor. O objetivo foi analisar bancos de dados de frangos de corte associados a dados meteorológicos utilizando técnicas de mineração de dados, seleção de atributos e classificação (�

The health effects of hotter summers and heat waves in the population of the United Kingdom: a review of the evidence.

Science.gov (United States)

Arbuthnott, Katherine G; Hajat, Shakoor

2017-12-05

It is widely acknowledged that the climate is warming globally and within the UK. In this paper, studies which assess the direct impact of current increased temperatures and heat-waves on health and those which project future health impacts of heat under different climate change scenarios in the UK are reviewed.This review finds that all UK studies demonstrate an increase in heat-related mortality occurring at temperatures above threshold values, with respiratory deaths being more sensitive to heat than deaths from cardiovascular disease (although the burden from cardiovascular deaths is greater in absolute terms). The relationship between heat and other health outcomes such as hospital admissions, myocardial infarctions and birth outcomes is less consistent. We highlight the main populations who are vulnerable to heat. Within the UK, these are older populations, those with certain co-morbidities and those living in Greater London, the South East and Eastern regions.In all assessments of heat-related impacts using different climate change scenarios, deaths are expected to increase due to hotter temperatures, with some studies demonstrating that an increase in the elderly population will also amplify burdens. However, key gaps in knowledge are found in relation to how urbanisation and population adaptation to heat will affect health impacts, and in relation to current and future strategies for effective, sustainable and equitable adaptation to heat. These and other key gaps in knowledge, both in terms of research needs and knowledge required to make sound public- health policy, are discussed.

Impacts of climate change on heat-related mortality risk across the Middle East and North Africa (MENA)

Science.gov (United States)

Moradkhani, H.; Ahmadalipour, A.

2017-12-01

It has been reported that even if the global mean temperature increase is limited to 2°C, warming over land will be far beyond that in many regions. Global climate change will increase the frequency and intensity of heatwaves and extreme high temperatures, which will in turn have severe impacts on human life. In this study, the mortality risk caused by excessive heat stress is investigated. Daily maximum air temperature and relative humidity are acquired from 17 CMIP5 Regional Climate Models (RCMs) developed by CORDEX at 0.44 degree spatial resolution. Then, the daily wet-bulb temperature is calculated and a recently developed health risk model is implemented to quantify the mortality risk. The study is applied over the latitudes 6.6°S-42°N and longitudes 20°W-60°E covering parts of 70 countries and accommodating over 600 million inhabitants. The analysis is performed for the historical period of 1951-2005 as well as two future scenarios of RCP4.5 (moderate) and RCP8.5 (business as usual) during 2006-2100. Results indicate about 5 to 30 times higher mortality risk in distant future compared to the historical period. The most aggravation of mortality risk over land is found at the southwestern regions of MENA, due to substantial increase in frequency and intensity of extreme temperatures. Mortality risk is found to be much higher over open waters and coastal regions due to abundant humidity, especially in the coastal regions of the Red sea and Persian Gulf.

Projected Heat Wave Characteristics over the Korean Peninsula During the Twenty-First Century

Science.gov (United States)

Shin, Jongsoo; Olson, Roman; An, Soon-Il

2018-02-01

Climate change is expected to increase temperatures globally, and consequently more frequent, longer, and hotter heat waves are likely to occur. Ambiguity in defining heat waves appropriately makes it difficult to compare changes in heat wave events over time. This study provides a quantitative definition of a heat wave and makes probabilistic heat wave projections for the Korean Peninsula under two global warming scenarios. Changes to heat waves under global warming are investigated using the representative concentration pathway 4.5 (RCP4.5) and 8.5 (RCP8.5) experiments from 30 coupled models participating in phase five of the Coupled Model Inter-comparison Project. Probabilistic climate projections from multi-model ensembles have been constructed using both simple and weighted averaging. Results from both methods are similar and show that heat waves will be more intense, frequent, and longer lasting. These trends are more apparent under the RCP8.5 scenario as compared to the RCP4.5 scenario. Under the RCP8.5 scenario, typical heat waves are projected to become stronger than any heat wave experienced in the recent measurement record. Furthermore, under this scenario, it cannot be ruled out that Korea will experience heat wave conditions spanning almost an entire summer before the end of the 21st century.

Future changes of temperature and heat waves in Ontario, Canada

Science.gov (United States)

Li, Zhong; Huang, Guohe; Huang, Wendy; Lin, Qianguo; Liao, Renfei; Fan, Yurui

2018-05-01

Apparent changes in the temperature patterns in recent years brought many challenges to the province of Ontario, Canada. As the need for adapting to climate change challenges increases, the development of reliable climate projections becomes a crucial task. In this study, a regional climate modeling system, Providing Regional Climates for Impacts Studies (PRECIS), is used to simulate the temperature patterns in Ontario. Three PRECIS runs with a resolution of 25 km × 25 km are carried out to simulate the present (1961-1990) temperature variations. There is a good match between the simulated and observed data, which validates the performance of PRECIS in reproducing temperature changes in Ontario. Future changes of daily maximum, mean, and minimum temperatures during the period 2071-2100 are then projected under the IPCC SRES A2 and B2 emission scenarios using PRECIS. Spatial variations of annual mean temperature, mean diurnal range, and temperature seasonality are generated. Furthermore, heat waves defined based on the exceedance of local climatology and their temporal and spatial characteristics are analyzed. The results indicate that the highest temperature and the most intensive heat waves are most likely to occur at the Toronto-Windsor corridor in Southern Ontario. The Northern Ontario, in spite of the relatively low projected temperature, would be under the risk of long-lasting heat waves, and thus needs effective measures to enhance its climate resilience in the future. This study can assist the decision makers in better understanding the future temperature changes in Ontario and provide decision support for mitigating heat-related loss.

Mortality selection during the 2003 European heat wave in three-spined sticklebacks: effects of parasites and MHC genotype

Directory of Open Access Journals (Sweden)

Milinski Manfred

2008-04-01

Full Text Available Abstract Background Ecological interaction strength may increase under environmental stress including temperature. How such stress enhances and interacts with parasite selection is almost unknown. We studied the importance of resistance genes of the major histocompatibility complex (MHC class II in 14 families of three-spined sticklebacks Gasterosteus aculeatus exposed to their natural macroparasites in field enclosures in the extreme summer of 2003. Results After a mass die-off during the 2003-European heat wave killing 78% of 277 experimental fish, we found strong differences in survival among and within families. In families with higher average parasite load fewer individuals survived. Multivariate analysis revealed that the composition of the infecting parasite fauna was family specific. Within families, individuals with an intermediate number of MHC class IIB sequence variants survived best and had the lowest parasite load among survivors, suggesting a direct functional link between MHC diversity and fitness. The within family MHC effects were, however, small compared to between family effects, suggesting that other genetic components or non-genetic effects were also important. Conclusion The correlation between parasite load and mortality that we found at both individual and family level might have appeared only in the extraordinary heatwave of 2003. Due to global warming the frequency of extreme climatic events is predicted to increase, which might intensify costs of parasitism and enhance selection on immune genes.

Heat conduction analysis of multi-layered FGMs considering the finite heat wave speed

International Nuclear Information System (INIS)

Rahideh, H.; Malekzadeh, P.; Golbahar Haghighi, M.R.

2012-01-01

Highlights: ► Using a layerwise-incremental differential quadrature for heat transfer of FGMs. ► Superior accuracy with fewer degrees of freedom of the method with respect to FEM. ► Considering multi-layered functionally graded materials. ► Hyperbolic heat transfer analysis of thermal system with heat generation. ► Showing the effect of heat wave speed on thermal characteristic of the system. - Abstract: In this work, the heat conduction with finite wave heat speed of multi-layered domain made of functionally graded materials (FGMs) subjected to heat generation is simulated. For this purpose, the domain is divided into a set of mathematical layers, the number of which can be equal or greater than those of the physical layers. Then, in each mathematical layer, the non-Fourier heat transfer equations are employed. Since, the governing equations have variable coefficients due to FGM properties, as an efficient and accurate method the differential quadrature method (DQM) is adopted to discretize both spatial and temporal domains in each layer. This results in superior accuracy with fewer degrees of freedom than conventional finite element method (FEM). To verify this advantages through some comparison studies, a finite element solution are also obtained. After demonstrating the convergence and accuracy of the method, the effects of heat wave speed for two different set of boundary conditions on the temperature distribution and heat flux of the domain are studied.

Human mortality impacts of the 2015 summer heat spells in Slovakia

Science.gov (United States)

Výberči, Dalibor; Labudová, Lívia; Eštóková, Milada; Faško, Pavol; Trizna, Milan

2017-07-01

In 2015, Central Europe experienced an unusually warm summer season. For a great majority of climatic stations around Slovakia, it had been the warmest summer ever recorded over their entire instrumental observation period. In this study, we investigate the mortality effects of hot days' sequences during that particular summer on the Slovak population. In consideration of the range of available mortality data, the position of 2015 is analysed within the years 1996-2015. Over the given 20-year period, the summer heat spells of 2015 were by far the most severe from a meteorological point of view, and clearly the deadliest with the total of almost 540 excess deaths. In terms of impacts, an extraordinary 10-day August heat spell was especially remarkable. The massive lethal effects of heat would have likely been even more serious under normal circumstances, since the number of premature deaths appeared to be partially reduced due to a non-standard mortality pattern in the first quarter of the year. The heat spells of the extremely warm summer of 2015 in Slovakia are notable not just for their short-term response in mortality. It appears that in a combination with the preceding strong influenza season, they subsequently affected mortality conditions in the country in the following months up until the end of the year. The impacts described above were rather different for selected population subgroups (men and women, the elderly). Both separately and as a part of the annual mortality cycle, the 2015 summer heat spells may represent a particularly valuable source of information for public health.

Relation between Temperature and Mortality in Thirteen Spanish Cities

Directory of Open Access Journals (Sweden)

Marc Sáez

2010-08-01

Full Text Available In this study we examined the shape of the association between temperature and mortality in 13 Spanish cities representing a wide range of climatic and socio-demographic conditions. The temperature value linked with minimum mortality (MMT and the slopes before and after the turning point (MMT were calculated. Most cities showed a V-shaped temperature-mortality relationship. MMTs were generally higher in cities with warmer climates. Cold and heat effects also depended on climate: effects were greater in hotter cities but lesser in cities with higher variability. The effect of heat was greater than the effect of cold. The effect of cold and MMT was, in general, greater for cardio-respiratory mortality than for total mortality, while the effect of heat was, in general, greater among the elderly.

Low-Frequency Waves in HF Heating of the Ionosphere

Science.gov (United States)

Sharma, A. S.; Eliasson, B.; Milikh, G. M.; Najmi, A.; Papadopoulos, K.; Shao, X.; Vartanyan, A.

2016-02-01

Ionospheric heating experiments have enabled an exploration of the ionosphere as a large-scale natural laboratory for the study of many plasma processes. These experiments inject high-frequency (HF) radio waves using high-power transmitters and an array of ground- and space-based diagnostics. This chapter discusses the excitation and propagation of low-frequency waves in HF heating of the ionosphere. The theoretical aspects and the associated models and simulations, and the results from experiments, mostly from the HAARP facility, are presented together to provide a comprehensive interpretation of the relevant plasma processes. The chapter presents the plasma model of the ionosphere for describing the physical processes during HF heating, the numerical code, and the simulations of the excitation of low-frequency waves by HF heating. It then gives the simulations of the high-latitude ionosphere and mid-latitude ionosphere. The chapter also briefly discusses the role of kinetic processes associated with wave generation.

Effects of roll waves on annular flow heat transfer at horizontal condenser tube

International Nuclear Information System (INIS)

Kondo, Masaya; Nakamura, Hideo; Anoda, Yoshinari; Sakashita, Akihiro

2002-01-01

Heat removal characteristic of a horizontal in-tube condensation heat exchanger is under investigation to be used for a passive containment cooling system (PCCS) of a next generation-type BWR. Flow regime observed at the inlet of the condenser tube was annular flow, and the local heat transfer rate was ∼20% larger than the prediction by the Dobson-Chato correlation. Roll waves were found to appear on the liquid film in the annular flow. The measured local condensation heat transfer rate was being closely related to the roll waves frequency. Based on these observations, a model is proposed which predicts the condensation heat transfer coefficient for annular flows around the tube inlet. The proposed model predicts well the influences of pressure, local gas-phase velocity and film thickness. (author)

Heat waves and their significance for a temperate benthic community: A near-natural experimental approach.

Science.gov (United States)

Pansch, Christian; Scotti, Marco; Barboza, Francisco R; Al-Janabi, Balsam; Brakel, Janina; Briski, Elizabeta; Bucholz, Björn; Franz, Markus; Ito, Maysa; Paiva, Filipa; Saha, Mahasweta; Sawall, Yvonne; Weinberger, Florian; Wahl, Martin

2018-04-23

Climate change will not only shift environmental means but will also increase the intensity of extreme events, exerting additional stress on ecosystems. While field observations on the ecological consequences of heat waves are emerging, experimental evidence is rare, and lacking at the community level. Using a novel "near-natural" outdoor mesocosms approach, this study tested whether marine summer heat waves have detrimental consequences for macrofauna of a temperate coastal community, and whether sequential heat waves provoke an increase or decrease of sensitivity to thermal stress. Three treatments were applied, defined and characterized through a statistical analysis of 15 years of temperature records from the experimental site: (1) no heat wave, (2) two heat waves in June and July followed by a summer heat wave in August and (3) the summer heat wave only. Overall, 50% of the species showed positive, negative or positive/negative responses in either abundance and/or biomass. We highlight four possible ways in which single species responded to either three subsequent heat waves or one summer heat wave: (1) absence of a response (tolerance, 50% of species), (2) negative accumulative effects by three subsequent heat waves (tellinid bivalve), (3) buffering by proceeding heat waves due to acclimation and/or shifts in phenology (spionid polychaete) and (4) an accumulative positive effect by subsequent heat waves (amphipod). The differential responses to single or sequential heat waves at the species level entailed shifts at the community level. Community-level differences between single and triple heat waves were more pronounced than those between regimes with vs. without heat waves. Detritivory was reduced by the single heat wave while suspension feeding was less common in the triple heat wave regime. Critical extreme events occur already today and will occur more frequently in a changing climate, thus, leading to detrimental impacts on coastal marine systems. �

Thermal responses in a coronal loop maintained by wave heating mechanisms

Science.gov (United States)

Matsumoto, Takuma

2018-05-01

A full 3-dimensional compressible magnetohydrodynamic (MHD) simulation is conducted to investigate the thermal responses of a coronal loop to the dynamic dissipation processes of MHD waves. When the foot points of the loop are randomly and continuously forced, the MHD waves become excited and propagate upward. Then, 1-MK temperature corona is produced naturally as the wave energy dissipates. The excited wave packets become non-linear just above the magnetic canopy, and the wave energy cascades into smaller spatial scales. Moreover, collisions between counter-propagating Alfvén wave packets increase the heating rate, resulting in impulsive temperature increases. Our model demonstrates that the heating events in the wave-heated loops can be nanoflare-like in the sense that they are spatially localized and temporally intermittent.

Atmospheric aerosol variability above the Paris Area during the 2015 heat wave - Comparison with the 2003 and 2006 heat waves

Science.gov (United States)

Chazette, Patrick; Totems, Julien; Shang, Xiaoxia

2017-12-01

The aerosol layers during the heat wave of July 2015 over Paris Area have been studied using a N2-Raman lidar with co- and cross-polarized channels. The lidar observations are examined to allow the identification of main aerosol types and their origins, in synergy with measurements of the AERONET sunphotometer network and back trajectory studies from the HYSPLIT model. The results are compatible with spaceborne observations of MODIS and CALIOP. As for previous heat waves of August 2003 and July 2006 occurring in France, the aerosol optical thickness is very large, up to 0.8 at the lidar wavelength of 355 nm (between 0.5 and 0.7 at 550 nm). However, air mass trajectories highlight that the observed aerosol layers may have multiple and diverse origins during the 2015 heat wave (North America, Northwest Africa, Southern and Northern Europe). Biomass burning, pollution and desert dust aerosols have been identified, using linear particle depolarization ratio, lidar ratio and analysis of back trajectories initiated at the altitudes and arrival times of the plumes. These layers are elevated and are shown to have little impact on surface aerosol concentrations (PM10 < 40 μg m-3 or PM2.5 < 25 μg m-3) and therefore no influence on the local air quality during the 2015 heat wave, unlike in 2003 and 2006. However, they significantly modify the radiative budget by trapping part of the solar ingoing/outgoing fluxes, which leads to a mean aerosol radiative forcing close to +50 ± 17 Wm-2 per aerosol optical thickness unit at 550 nm (AOT550) for solar zenith angles between 55 and 75°, which are available from sunphotometer measurements. This value is smaller than those of the 2003 and 2006 heat waves, which are assessed to be +95 ± 13 and +70 ± 18 Wm-2/AOT550, respectively. The differences between the heat wave of 2015 and the others are mainly due to both the nature and the diversity of aerosols, as indicated by the dispersion of the single scattering albedo distributions at

Particle simulation of intense electron cyclotron heating and beat-wave current drive

International Nuclear Information System (INIS)

Cohen, B.I.

1987-01-01

High-power free-electron lasers make new methods possible for heating plasmas and driving current in toroidal plasmas with electromagnetic waves. We have undertaken particle simulation studies with one and two dimensional, relativistic particle simulation codes of intense pulsed electron cyclotron heating and beat-wave current drive. The particle simulation methods here are conventional: the algorithms are time-centered, second-order-accurate, explicit, leap-frog difference schemes. The use of conventional methods restricts the range of space and time scales to be relatively compact in the problems addressed. Nevertheless, experimentally relevant simulations have been performed. 10 refs., 2 figs

[Media and public health: example of heat wave during summer 2003].

Science.gov (United States)

Boyer, L; Robitail, S; Debensason, D; Auquier, P; San Marco, J-L

2005-11-01

The summer of 2003 was the hottest for France in the last 50 years with record day and nighttime temperatures. INSERM statistics estimated that 14,802 heat-related deaths occurred during August 2003 heat wave in France. In the aftermath of this crisis, we thought that it was useful to analyze how the French media dealt with public health during the period from June 1 to August 31, 2003. The objective was to analyze French coverage of public health information during the August 2003 heat wave. Manual and computerized analysis of newspaper and radio reports published from June 1 to August 31, 2003. Articles were obtained by searching the EUROPRESS database. Text analysis was performed using the ALCESTE software package. A total of 1,599 articles were analyzed. Few articles contained warnings about heat exposure and preventive measures. Public health policy was relegated to third place after business and ecology themes. The special problems of the high-risk populations were not mentioned until after the rising death toll was known and emphasis was placed on the implications of the crisis in the political process. The findings of this study show the poor performance of public health policy in France and that media must be given guidance to fulfil its role in providing public health information. This crisis discloses the absence of public health culture in France and involves the "social exclusion" related to a breakdown of social cohesion. More cooperation is needed between the media and public health professionals to avoid future heat-wave and other public health crises. France must develop a public health culture to promote involvement of both the community and individuals in public health issues.

Syndromic surveillance and heat wave morbidity: a pilot study based on emergency departments in France

Directory of Open Access Journals (Sweden)

Filleul Laurent

2009-02-01

Full Text Available Abstract Background The health impacts of heat waves are serious and have prompted the development of heat wave response plans. Even when they are efficient, these plans are developed to limit the health effects of heat waves. This study was designed to determine relevant indicators related to health effects of heat waves and to evaluate the ability of a syndromic surveillance system to monitor variations in the activity of emergency departments over time. The study uses data collected during the summer 2006 when a new heat wave occurred in France. Methods Data recorded from 49 emergency departments since July 2004, were transmitted daily via the Internet to the French Institute for Public Health Surveillance. Items collected on patients included diagnosis (ICD10 codes, outcome, and age. Statistical t-tests were used to compare, for several health conditions, the daily averages of patients within different age groups and periods (whether 'on alert' or 'off alert'. Results A limited number of adverse health conditions occurred more frequently during hot period: dehydration, hyperthermia, malaise, hyponatremia, renal colic, and renal failure. Over all health conditions, the total number of patients per day remained equal between the 'on alert' and 'off alert' periods (4,557.7/day vs. 4,511.2/day, but the number of elderly patients increased significantly during the 'on alert' period relative to the 'off alert' period (476.7/day vs. 446.2/day p Conclusion Our results show the interest to monitor specific indicators during hot periods and to focus surveillance efforts on the elderly. Syndromic surveillance allowed the collection of data in real time and the subsequent optimization of the response by public health agencies. This method of surveillance should therefore be considered as an essential part of efforts to prevent the health effects of heat waves.

Role of soil moisture versus recent climate change for the 2010 heat wave in western Russia

Science.gov (United States)

Hauser, Mathias; Orth, René; Seneviratne, Sonia I.

2016-03-01

The severe 2010 heat wave in western Russia was found to be influenced by anthropogenic climate change. Additionally, soil moisture-temperature feedbacks were deemed important for the buildup of the exceptionally high temperatures. We quantify the relative role of both factors by applying the probabilistic event attribution framework and analyze ensemble simulations to distinguish the effect of climate change and the 2010 soil moisture conditions for annual maximum temperatures. The dry 2010 soil moisture alone has increased the risk of a severe heat wave in western Russia sixfold, while climate change from 1960 to 2000 has approximately tripled it. The combined effect of climate change and 2010 soil moisture yields a 13 times higher heat wave risk. We conclude that internal climate variability causing the dry 2010 soil moisture conditions formed a necessary basis for the extreme heat wave.

Valoración del impacto de la ola de calor del verano de 2003 sobre la mortalidad Evaluation of the impact of the heat wave in the summer of 2003 on mortality

Directory of Open Access Journals (Sweden)

Gonzalo López-Abente

2004-05-01

compared with expected estimated applying a Poisson regression model to historical mortality series adjusting for the upwards trend and seasonality observed. Meteorological information was provided by the National Institute of Meteorology. Spain experienced three heat waves. Total excess deaths associated was 8% (43212 observed compared with 40046 expected. Excess deaths were only observed among 65 years old and over (15%. The increased mortality was also observed in rural villages. This phenomenon is becoming an emerging public health problem because of its increasing attributable risk because of the aging of Spanish population. Alert and response systems based on monitoring of climate related risks, emergency rooms activity and mortality and the strengthening of social and health services response capacity should be considered.

Modelling domestic stock energy use and heat-related health risk : a GIS-based bottom-up modelling approach

Energy Technology Data Exchange (ETDEWEB)

Mavrogianni, A.; Davies, M. [Univ. College London, London (United Kingdom). Bartlett School of Graduate Studies; Chalabi, Z.; Wilkinson, P. [London School of Hygiene and Tropical Medecine, London (United Kingdom); Kolokotroni, M. [Brunel Univ., London (United Kingdom). School of Engineering Design

2009-07-01

Approximately 8 per cent of the carbon dioxide (CO{sub 2}) emissions produced in the United Kingdom are produced in London, one of the fastest growing cities worldwide. Based on the projected rates of population and economic growth, a 15 per cent increase of emissions is predicted. In addition to the national target to cut emissions by 80 per cent by 2050, the Mayor of London Climate Change Action Plan set a target to reduce London's CO{sub 2} emissions by 60 per cent by 2025. Significant carbon savings can be achieved in the building sector, particularly since 38 per cent of the total delivered energy in London is associated with domestic energy use. This paper demonstrated a systematic approach towards exploring the impact of urban built form and the combined effect of climate change and the urban heat island (UHI) phenomenon on the levels of domestic energy consumption and heat-related health risk in London. It presented work in progress on the development of a GIS-based energy consumption model and heat vulnerability index of the Greater London Area domestic stock. Comparison of the model output for 10 case study areas with topdown energy statistics revealed that the model successfully ranks areas based on their domestic space heating demand. The health module can be used to determine environments prone to higher risk of heat stress by investigating urban texture factors. A newly developed epidemiological model will be feed into the health module to examine the influence on risk of heat-related mortality of local urban built form characteristics. The epidemiological model is based on multi-variable analysis of deaths during heat wave and non-heat wave days. 29 refs., 1 tab., 7 figs.

Effects of heat waves on daily excess mortality in 14 Korean cities during the past 20 years (1991-2010): an application of the spatial synoptic classification approach

Science.gov (United States)

Lee, Dae-Geun; Kim, Kyu Rang; Kim, Jiyoung; Kim, Baek-Jo; Cho, Chun-Ho; Sheridan, Scott C.; Kalkstein, Laurence S.; Kim, Ho; Yi, Seung-Muk

2017-11-01

The aims of this study are to explore the "offensive" summer weather types classified under the spatial synoptic classification (SSC) system and to evaluate their impacts on excess mortality in 14 Korean cities. All-cause deaths per day for the entire population were examined over the summer months (May-September) of 1991-2010. Daily deaths were standardized to account for long-term trends of subcycles (annual, seasonal, and weekly) at the mid-latitudes. In addition, a mortality prediction model was constructed through multiple stepwise regression to develop a heat-health warning system based on synoptic climatology. The result showed that dry tropical (DT) days during early summer caused excess mortality due to non-acclimatization by inhabitants, and moist tropical (MT) plus and double plus resulted in greater spikes of excess mortality due to extremely hot and humid conditions. Among the 14 Korean cities, highly excess mortality for the elderly was observed in Incheon (23.2%, 95%CI 5.6), Seoul (15.8%, 95%CI 2.6), and Jeonju (15.8%, 95%CI 4.6). No time lag effect was observed, and excess mortality gradually increased with time and hot weather simultaneously. The model showed weak performance as its predictions were underestimated for the validation period (2011-2015). Nevertheless, the results clearly revealed the efficiency of relative and multiple-variable approaches better than absolute and single-variable approaches. The results indicate the potential of the SSC as a suitable system for investigating heat vulnerability in South Korea, where hot summers could be a significant risk factor.

The effects of the 1996–2012 summer heat events on human mortality in Slovakia

Directory of Open Access Journals (Sweden)

Výberči Dalibor

2015-09-01

Full Text Available The impacts of summer heat events on the mortality of the Slovak population, both in total and for selected population sub-groups, are the foci of this study. This research is the first of its kind, focusing on a given population, and therefore one priority was to create a knowledge base for the issue and to basically evaluate existing conditions for the heat-mortality relationship in Slovakia. This article also aims to fill a void in current research on these issues in Europe. In addition to overall effects, we focused individually on the major historical heat events which occurred in the summers of 2007, 2010 and 2012. During the heat events, a non-negligible negative response in mortality was recorded and fatal effects were more pronounced during particularly strong heat events and periods which lasted for two or more days. In general, females and the elderly were the most sensitive groups in the population and mortality was characterized by several specific effects in individual population groups. The most extreme heat periods were commonly followed by a deficit in mortality, corresponding to a short-term mortality displacement, the pattern of which varied in specific cases. In general, displaced mortality appeared to compensate for a large part of heat-induced excess deaths.

Alfvén Wave Turbulence as a Coronal Heating Mechanism: Simultaneously Predicting the Heating Rate and the Wave-induced Emission Line Broadening

Energy Technology Data Exchange (ETDEWEB)

Oran, R. [Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139 (United States); Landi, E.; Holst, B. van der; Sokolov, I. V.; Gombosi, T. I., E-mail: roran@mit.edu [Atmospheric, Oceanic and Atmospheric Sciences, University of Michigan, 2455 Hayward, Ann Arbor, MI, 48109 (United States)

2017-08-20

We test the predictions of the Alfvén Wave Solar Model (AWSoM), a global wave-driven magnetohydrodynamic (MHD) model of the solar atmosphere, against high-resolution spectra emitted by the quiescent off-disk solar corona. AWSoM incorporates Alfvén wave propagation and dissipation in both closed and open magnetic field lines; turbulent dissipation is the only heating mechanism. We examine whether this mechanism is consistent with observations of coronal EUV emission by combining model results with the CHIANTI atomic database to create synthetic line-of-sight spectra, where spectral line widths depend on thermal and wave-related ion motions. This is the first time wave-induced line broadening is calculated from a global model with a realistic magnetic field. We used high-resolution SUMER observations above the solar west limb between 1.04 and 1.34 R {sub ⊙} at the equator, taken in 1996 November. We obtained an AWSoM steady-state solution for the corresponding period using a synoptic magnetogram. The 3D solution revealed a pseudo-streamer structure transversing the SUMER line of sight, which contributes significantly to the emission; the modeled electron temperature and density in the pseudo-streamer are consistent with those observed. The synthetic line widths and the total line fluxes are consistent with the observations for five different ions. Further, line widths that include the contribution from the wave-induced ion motions improve the correspondence with observed spectra for all ions. We conclude that the turbulent dissipation assumed in the AWSoM model is a viable candidate for explaining coronal heating, as it is consistent with several independent measured quantities.

Identifying Changes in the Probability of High Temperature, High Humidity Heat Wave Events

Science.gov (United States)

Ballard, T.; Diffenbaugh, N. S.

2016-12-01

Understanding how heat waves will respond to climate change is critical for adequate planning and adaptation. While temperature is the primary determinant of heat wave severity, humidity has been shown to play a key role in heat wave intensity with direct links to human health and safety. Here we investigate the individual contributions of temperature and specific humidity to extreme heat wave conditions in recent decades. Using global NCEP-DOE Reanalysis II daily data, we identify regional variability in the joint probability distribution of humidity and temperature. We also identify a statistically significant positive trend in humidity over the eastern U.S. during heat wave events, leading to an increased probability of high humidity, high temperature events. The extent to which we can expect this trend to continue under climate change is complicated due to variability between CMIP5 models, in particular among projections of humidity. However, our results support the notion that heat wave dynamics are characterized by more than high temperatures alone, and understanding and quantifying the various components of the heat wave system is crucial for forecasting future impacts.

The impact of heat on mortality and morbidity in the Greater Metropolitan Sydney Region: a case crossover analysis.

Science.gov (United States)

Wilson, Leigh Ann; Morgan, Geoffrey Gerard; Hanigan, Ivan Charles; Johnston, Fay H; Abu-Rayya, Hisham; Broome, Richard; Gaskin, Clive; Jalaludin, Bin

2013-11-15

This study examined the association between unusually high temperature and daily mortality (1997-2007) and hospital admissions (1997-2010) in the Sydney Greater Metropolitan Region (GMR) to assist in the development of targeted health programs designed to minimise the public health impact of extreme heat. Sydney GMR was categorized into five climate zones. Heat-events were defined as severe or extreme. Using a time-stratified case-crossover design with a conditional logistic regression model we adjusted for influenza epidemics, public holidays, and climate zone. Odds ratios (OR) and 95% confidence intervals were estimated for associations between daily mortality and hospital admissions with heat-event days compared to non-heat event days for single and three day heat-events. All-cause mortality overall had similar magnitude associations with single day and three day extreme and severe events as did all cardiovascular mortality. Respiratory mortality was associated with single day and three day severe events (95th percentile, lag0: OR = 1.14; 95%CI: 1.04 to 1.24). Diabetes mortality had similar magnitude associations with single day and three day severe events (95th percentile, lag0: OR = 1.22; 95%CI: 1.03 to 1.46) but was not associated with extreme events. Hospital admissions for heat related injuries, dehydration, and other fluid disorders were associated with single day and three day extreme and severe events. Contrary to our findings for mortality, we found inconsistent and sometimes inverse associations for extreme and severe events with cardiovascular disease and respiratory disease hospital admissions. Controlling for air pollutants did not influence the mortality associations but reduced the magnitude of the associations with hospital admissions particularly for ozone and respiratory disease. Single and three day events of unusually high temperatures in Sydney are associated with similar magnitude increases in mortality and hospital admissions. The trend

Hamiltonian study of the response of a tokamak plasma to the ion cyclotron heating wave: minor heating and current generation by the fast wave

International Nuclear Information System (INIS)

Becoulet, A.

1990-06-01

The role of additional Heatings, such as the Ion Cyclotron Heating, is to raise magnetic fusion plasmas to higher temperatures, to satisfy the ignition condition. The understanding of the wave absorption mechanisms by the plasma first requires a precise description of the particle individual trajectories. The Hamiltonian mechanics, through action-angle variables, allows this description, and makes the computation of the wave-particle interaction easier. We then derive a quantitative evaluation of the intrinsic stochasticity for ionic trajectories perturbated by the fast wave. This stochasticity, combinated to the collisional effects, gives the validity domain for a quasilinear approximation of the evolution equation. This equation is then written under a variational formulation, and solved semi-analytically. Results conclude to the importance of the Hamiltonian chaos in the formation of the deeply anisotropic distribution tails, encountered in minority heating scenarios. Direct interaction of the electrons and the fast wave is similarly analysed. The influence of the various parameters (wave spectrum, magnetic configuration, frequency,...) is then examined in order to optimize this scenario of fast wave current drive in tokamaks [fr

Future Heat Waves In Asia

Science.gov (United States)

Eltahir, E. A. B.

2017-12-01

I will review recent work from my group on the impact of climate change on the intensity and frequency of heat waves in Asia. Our studies covered Southwest Asia, South Asia, East China, and the Maritime continent. In any of these regions, the risk associated with climate change impact reflects intensity of natural hazard and level of human vulnerability. Previous work has shown that the wet-bulb temperature is a useful variable to consider in describing the natural hazard from heat waves since it can be easily compared to the natural threshold that defines the upper limit on human survivability. Based on an ensemble of high resolution climate change simulations, we project extremes of wet-bulb temperature conditions in each of these four regions of Asia. We consider the business-as-usual scenario of future greenhouse gas emissions, as well as a moderate mitigation scenario. The results from these regions will be compared and lessons learned summarized.

Study of ECG changes and its relation to mortality in cases of cerebrovascular accidents.

Science.gov (United States)

Purushothaman, Suja; Salmani, Deepalaxmi; Prarthana, Kaleramma Gopalakrishna; Bandelkar, Srinidhi Muddanna Gundappa; Varghese, Sarah

2014-07-01

Its being long recognized about the highly debilitating and destructive nature of cerebrovascular accidents (CVAs). Around the world CVAs has posed as a major factor in medical morbidity and mortality. It has thrown up challenges with regards to their medical management and also towards posttreatment rehabilitation. It is well-known that neurologic disorder contributes variously towards varied electrocardiogram (ECG) changes and stroke is no exception. To study the ECG changes and its relation to mortality in cases of CVA. A total of 100 patients with acute stroke were enrolled in the study. All the 100 patients underwent ECG recording within first 24 h of admission. The patients were divided into ischemic and hemorrhagic group depending on the nature of lesion. Out of 100 cases, 58 were ischemic and 42 were hemorrhagic. The ECG changes were noted in 78 patients. Among the ischemic group, the changes noted in the ECG were: T wave inversion (34.48%), ST segment depression (32.75%), QTc prolongation (29.31%), and presence of U waves (27.58%). In cases of hemorrhagic stroke, it was: T wave inversion (33.33%), arrhythmias (33.33%), U waves (30.95%), and ST segment depression (23.80%). Mortality was higher in patients with ST-T changes in ischemic group (66.66%) and in patients with positive U waves (60%) in hemorrhagic group. In acute stroke patients, changes in ECG were commonly seen. The changes varied from T-wave inversion to ST segment depression in ischemic stroke. In hemorrhagic stroke it consisted of T wave inversion and arrhythmias. Overall mortality was high in cases of hemorrhagic compared to ischemic group.

Ambient high temperature and mortality in Jinan, China: A study of heat thresholds and vulnerable populations.

Science.gov (United States)

Li, Jing; Xu, Xin; Yang, Jun; Liu, Zhidong; Xu, Lei; Gao, Jinghong; Liu, Xiaobo; Wu, Haixia; Wang, Jun; Yu, Jieqiong; Jiang, Baofa; Liu, Qiyong

2017-07-01

Understanding the health consequences of continuously rising temperatures-as is projected for China-is important in terms of developing heat-health adaptation and intervention programs. This study aimed to examine the association between mortality and daily maximum (T max ), mean (T mean ), and minimum (T min ) temperatures in warmer months; to explore threshold temperatures; and to identify optimal heat indicators and vulnerable populations. Daily data on temperature and mortality were obtained for the period 2007-2013. Heat thresholds for condition-specific mortality were estimated using an observed/expected analysis. We used a generalised additive model with a quasi-Poisson distribution to examine the association between mortality and T max /T min /T mean values higher than the threshold values, after adjustment for covariates. T max /T mean /T min thresholds were 32/28/24°C for non-accidental deaths; 32/28/24°C for cardiovascular deaths; 35/31/26°C for respiratory deaths; and 34/31/28°C for diabetes-related deaths. For each 1°C increase in T max /T mean /T min above the threshold, the mortality risk of non-accidental-, cardiovascular-, respiratory, and diabetes-related death increased by 2.8/5.3/4.8%, 4.1/7.2/6.6%, 6.6/25.3/14.7%, and 13.3/30.5/47.6%, respectively. Thresholds for mortality differed according to health condition when stratified by sex, age, and education level. For non-accidental deaths, effects were significant in individuals aged ≥65 years (relative risk=1.038, 95% confidence interval: 1.026-1.050), but not for those ≤64 years. For most outcomes, women and people ≥65 years were more vulnerable. High temperature significantly increases the risk of mortality in the population of Jinan, China. Climate change with rising temperatures may bring about the situation worse. Public health programs should be improved and implemented to prevent and reduce health risks during hot days, especially for the identified vulnerable groups. Copyright

Projections of Heat Waves Events in the Intra-Americas Region Using Multimodel Ensemble

Directory of Open Access Journals (Sweden)

Moises Angeles-Malaspina

2018-01-01

Full Text Available Significant accelerated warming of the Sea Surface Temperature of 0.15°C per decade (1982–2012 was recently detected, which motivated the research for the present consequences and future projections on the heat index and heat waves in the intra-Americas region. Present records every six hours are retrieved from NCEP reanalysis (1948–2015 to calculate heat waves changes. Heat index intensification has been detected in the region since 1998 and driven by surface pressure changes, sinking air enhancement, and warm/weaker cold advection. This regional warmer atmosphere leads to heat waves intensification with changes in both frequency and maximum amplitude distribution. Future projections using a multimodel ensemble mean for five global circulation models were used to project heat waves in the future under two scenarios: RCP4.5 and RCP8.5. Massive heat waves events were projected at the end of the 21st century, particularly in the RCP8.5 scenario. Consequently, the regional climate change in the current time and in the future will require special attention to mitigate the more intense and frequent heat waves impacts on human health, countries’ economies, and energy demands in the IAR.

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

Science.gov (United States)

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.

Effects of heat waves on daily excess mortality in 14 Korean cities during the past 20 years (1991-2010): an application of the spatial synoptic classification approach.

Science.gov (United States)

Lee, Dae-Geun; Kim, Kyu Rang; Kim, Jiyoung; Kim, Baek-Jo; Cho, Chun-Ho; Sheridan, Scott C; Kalkstein, Laurence S; Kim, Ho; Yi, Seung-Muk

2018-04-01

The aims of this study are to explore the "offensive" summer weather types classified under the spatial synoptic classification (SSC) system and to evaluate their impacts on excess mortality in 14 Korean cities. All-cause deaths per day for the entire population were examined over the summer months (May-September) of 1991-2010. Daily deaths were standardized to account for long-term trends of subcycles (annual, seasonal, and weekly) at the mid-latitudes. In addition, a mortality prediction model was constructed through multiple stepwise regression to develop a heat-health warning system based on synoptic climatology. The result showed that dry tropical (DT) days during early summer caused excess mortality due to non-acclimatization by inhabitants, and moist tropical (MT) plus and double plus resulted in greater spikes of excess mortality due to extremely hot and humid conditions. Among the 14 Korean cities, highly excess mortality for the elderly was observed in Incheon (23.2%, 95%CI 5.6), Seoul (15.8%, 95%CI 2.6), and Jeonju (15.8%, 95%CI 4.6). No time lag effect was observed, and excess mortality gradually increased with time and hot weather simultaneously. The model showed weak performance as its predictions were underestimated for the validation period (2011-2015). Nevertheless, the results clearly revealed the efficiency of relative and multiple-variable approaches better than absolute and single-variable approaches. The results indicate the potential of the SSC as a suitable system for investigating heat vulnerability in South Korea, where hot summers could be a significant risk factor.

Spectral Effects on Fast Wave Core Heating and Current Drive

International Nuclear Information System (INIS)

Phillips, C.K.; Bell, R.E.; Berry, L.A.; Bonoli, P.T.; Harvey, R.W.; Hosea, J.C.; Jaeger, E.F.; LeBlanc, B.P.; Ryan, P.M.; Taylor, G.; Valeo, E.J.; Wilson, J.R.; Wright, J.C.; Yuh, H. and the NSTX Team

2009-01-01

Recent results obtained with high harmonic fast wave (HHFW) heating and current drive (CD) on NSTX strongly support the hypothesis that the onset of perpendicular fast wave propagation right at or very near the launcher is a primary cause for a reduction in core heating efficiency at long wavelengths that is also observed in ICRF heating experiments in numerous tokamaks. A dramatic increase in core heating efficiency was first achieved in NSTX L-mode helium majority plasmas when the onset for perpendicular wave propagation was moved away from the antenna and nearby vessel structures. Efficient core heating in deuterium majority L mode and H mode discharges, in which the edge density is typically higher than in comparable helium majority plasmas, was then accomplished by reducing the edge density in front of the launcher with lithium conditioning and avoiding operational points prone to instabilities. These results indicate that careful tailoring of the edge density profiles in ITER should be considered to limit rf power losses to the antenna and plasma facing materials. Finally, in plasmas with reduced rf power losses in the edge regions, the first direct measurements of high harmonic fast wave current drive were obtained with the motional Stark effect (MSE) diagnostic. The location and radial dependence of HHFW CD measured by MSE are in reasonable agreement with predictions from both full wave and ray tracing simulations

An analysis of JET fast-wave heating and current drive experiments directly related to ITER

Energy Technology Data Exchange (ETDEWEB)

Bhatnagar, V P; Eriksson, L; Gormezano, C; Jacquinot, J; Kaye, A; Start, D F.H. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking

1994-07-01

The ITER fast-wave system is required to serve a variety of purposes, in particular, plasma heating to ignition, current profile and burn control and eventually, in conjunction with other schemes, a central non-inductive current drive (CD) for the steady-state operation of ITER. The ICRF heating and current drive data that has been obtained in JET are analyzed in terms of dimensionless parameters, with a view to ascertaining its direct relevance to key ITER requirements. The analysis is then used to identify areas both in physics and technological aspects of ion-cyclotron resonance heating (ICRH) and CD that require further experimentation in ITER-relevant devices such as JET to establish the required data base. (authors). 12 refs., 8 figs.

An analysis of JET fast-wave heating and current drive experiments directly related to ITER

International Nuclear Information System (INIS)

Bhatnagar, V.P.; Eriksson, L.; Gormezano, C.; Jacquinot, J.; Kaye, A.; Start, D.F.H.

1994-01-01

The ITER fast-wave system is required to serve a variety of purposes, in particular, plasma heating to ignition, current profile and burn control and eventually, in conjunction with other schemes, a central non-inductive current drive (CD) for the steady-state operation of ITER. The ICRF heating and current drive data that has been obtained in JET are analyzed in terms of dimensionless parameters, with a view to ascertaining its direct relevance to key ITER requirements. The analysis is then used to identify areas both in physics and technological aspects of ion-cyclotron resonance heating (ICRH) and CD that require further experimentation in ITER-relevant devices such as JET to establish the required data base. (authors). 12 refs., 8 figs

PROTOPLANETARY DISK HEATING AND EVOLUTION DRIVEN BY SPIRAL DENSITY WAVES

Energy Technology Data Exchange (ETDEWEB)

Rafikov, Roman R., E-mail: rrr@ias.edu [Institute for Advanced Study, Einstein Drive, Princeton, NJ 08540 (United States)

2016-11-10

Scattered light imaging of protoplanetary disks often reveals prominent spiral arms, likely excited by massive planets or stellar companions. Assuming that these arms are density waves, evolving into spiral shocks, we assess their effect on the thermodynamics, accretion, and global evolution of the disk. We derive analytical expressions for the direct (irreversible) heating, angular momentum transport, and mass accretion rate induced by disk shocks of arbitrary amplitude. These processes are very sensitive to the shock strength. We show that waves of moderate strength (density jump at the shock ΔΣ/Σ ∼ 1) result in negligible disk heating (contributing at the ∼1% level to the energy budget) in passive, irradiated protoplanetary disks on ∼100 au scales, but become important within several au. However, shock heating is a significant (or even dominant) energy source in disks of cataclysmic variables, stellar X-ray binaries, and supermassive black hole binaries, heated mainly by viscous dissipation. Mass accretion induced by the spiral shocks is comparable to (or exceeds) the mass inflow due to viscous stresses. Protoplanetary disks featuring prominent global spirals must be evolving rapidly, in ≲0.5 Myr at ∼100 au. A direct upper limit on the evolution timescale can be established by measuring the gravitational torque due to the spiral arms from the imaging data. We find that, regardless of their origin, global spiral waves must be important agents of the protoplanetary disk evolution. They may serve as an effective mechanism of disk dispersal and could be related to the phenomenon of transitional disks.

PROTOPLANETARY DISK HEATING AND EVOLUTION DRIVEN BY SPIRAL DENSITY WAVES

International Nuclear Information System (INIS)

Rafikov, Roman R.

2016-01-01

Scattered light imaging of protoplanetary disks often reveals prominent spiral arms, likely excited by massive planets or stellar companions. Assuming that these arms are density waves, evolving into spiral shocks, we assess their effect on the thermodynamics, accretion, and global evolution of the disk. We derive analytical expressions for the direct (irreversible) heating, angular momentum transport, and mass accretion rate induced by disk shocks of arbitrary amplitude. These processes are very sensitive to the shock strength. We show that waves of moderate strength (density jump at the shock ΔΣ/Σ ∼ 1) result in negligible disk heating (contributing at the ∼1% level to the energy budget) in passive, irradiated protoplanetary disks on ∼100 au scales, but become important within several au. However, shock heating is a significant (or even dominant) energy source in disks of cataclysmic variables, stellar X-ray binaries, and supermassive black hole binaries, heated mainly by viscous dissipation. Mass accretion induced by the spiral shocks is comparable to (or exceeds) the mass inflow due to viscous stresses. Protoplanetary disks featuring prominent global spirals must be evolving rapidly, in ≲0.5 Myr at ∼100 au. A direct upper limit on the evolution timescale can be established by measuring the gravitational torque due to the spiral arms from the imaging data. We find that, regardless of their origin, global spiral waves must be important agents of the protoplanetary disk evolution. They may serve as an effective mechanism of disk dispersal and could be related to the phenomenon of transitional disks.

Characteristics of ion Bernstein wave heating in JIPPT-II-U tokamak

International Nuclear Information System (INIS)

Okamoto, M.; Ono, M.

1985-11-01

Using a transport code combined with an ion Bernstein wave tokamak ray tracing code, a modelling code for the ion Bernstein wave heating has been developed. Using this code, the ion Bernstein wave heating experiment on the JIPPT-II-U tokamak has been analyzed. It is assumed that the resonance layer is formed by the third harmonic of deuterium-like ions, such as fully ionized carbon, and oxygen ions near the plasma center. For wave absorption mechanisms, electron Landau damping, ion cyclotron harmonic damping, and collisional damping are considered. The characteristics of the ion Bernstein wave heating experiment, such as the ion temperature increase, the strong dependence of the quality factor on the magnetic field strength, and the dependence of the ion temperature increment on the input power, are well reproduced

US Drought-Heat Wave Relationships in Past Versus Current Climates

Science.gov (United States)

Cheng, L.; Hoerling, M. P.; Eischeid, J.; Liu, Z.

2017-12-01

This study explores the relationship between droughts and heat waves over various regions of the contiguous United States that are distinguished by so-called energy-limited versus water-limited climatologies. We first examine the regional sensitivity of heat waves to soil moisture variability under 19th century climate conditions, and then compare to sensitivities under current climate that has been subjected to human-induced change. Our approach involves application of the conditional statistical framework of vine copula. Vine copula is known for its flexibility in reproducing various dependence structures exhibited by climate variables. Here we highlight its feature for evaluating the importance of conditional relationships between variables and processes that capture underlying physical factors involved in their interdependence during drought/heat waves. Of particular interest is identifying changes in coupling strength between heat waves and land surface conditions that may yield more extreme events as a result of land surface feedbacks. We diagnose two equilibrium experiments a coupled climate model (CESM1), one subjected to Year-1850 external forcing and the other to Year-2000 radiative forcing. We calculate joint heat wave/drought relationships for each climate state, and also calculate their change as a result of external radiative forcing changes across this 150-yr period. Our results reveal no material change in the dependency between heat waves and droughts, aside from small increases in coupling strength over the Great Plains. Overall, hot U.S. summer droughts of 1850-vintage do not become hotter in the current climate -- aside from the warming contribution of long-term climate change, in CESM1. The detectability of changes in hotter droughts as a consequence of anthropogenic forced changes in this single effect, i.e. coupling strength between soil moisture and hot summer temperature, is judged to be low at this time.

Heat driven thermoacoustic cooler based on traveling-standing wave

International Nuclear Information System (INIS)

Kang Huifang; Zhou Gang; Li Qing

2010-01-01

This paper presents a heat driven thermoacoustic cooler system without any moving part. It consists of a thermoacoustic engine and a thermoacoustic cooler, and the former is the driving source of the latter. Both the engine and the cooler are located in one loop tube coupled with a resonator tube, and the acoustic power produced by the engine is used to drive the cooler directly. Both regenerators of the engine and the cooler are located in the near region of the pressure antinode, and operate in traveling-standing wave phase region. In the engine's regenerator, both components of the standing wave and the traveling wave realize the conversion from heat to acoustic energy. This improves the efficiency of the engine. In the cooler's regenerator, both components of the traveling wave and the standing wave pump heat from the cold end. This improves the efficiency of the cooler. At the operating point with a mean pressure of 22 bar, helium as working gas, a frequency of 234 Hz, and a heating power of 300 W, the experimental cooler provides a no-load temperature of -30 deg. C and a cooling power of 40 W at the cooling temperature of 0 deg. C. The total length of this cooler system is less than 1 m, which shows a good prospect for the domestic cooler system in room-temperature cooling such as food refrigeration and air-conditioning.

Plasma heating via electron Bernstein wave heating using ordinary and extraodinary mode

Directory of Open Access Journals (Sweden)

A. Parvazian

2008-03-01

Full Text Available Magnetically confined plasma can be heated with high power microwave sources. In spherical torus the electron plasma frequency exeeds the electron cyclotron frequency (EC and, as a consequence, electromagnetic waves at fundamental and low harmonic EC cannot propagate within the plasma. In contrast, electron Bernstein waves (EBWs readily propagate in spherical torus plasma and are absorbed strongly at the electron cyclotron resonances. In order to proagate EBWs beyond the upper hybrid resonance (UHR, that surrounds the plasma, the EBWs must convert via one of two processes to either ordinary (O-mode or extraordinary (X-mode electromagnetic waves. O-mode and X-mode electromagnetic waves lunched at the plasma edge can convert to the electron Bernstein waves (EBWs which can propagate without and cut-off into the core of the plasma and damp on electrons. Since the electron Bernstein wave (EBW has no cut-off limits, it is well suited to heat an over-dense plasma by resonant absorption. An important problem is to calculate mode conversion coefficient that is very sensitive to density. Mode conversion coefficient depends on Budden parameter ( ñ and density scale length (Ln in upper hybrid resonance (UHR. In Mega Ampere Spherical Tokamak (MAST, the optimized conversion efficiency approached 72.5% when Ln was 4.94 cm and the magnetic field was 0.475 Tesla in the core of the plasma.

Enhancement of ionic conductivity in stabilized zirconia ceramics under millimeter-wave irradiation heating

International Nuclear Information System (INIS)

Kishimoto, Akira; Ayano, Keiko; Hayashi, Hidetaka

2011-01-01

Ionic conductivity in yttria-stabilized zirconia ceramics under millimeter-wave irradiation heating was compared with that obtained using conventional heating. The former was found to result in higher conductivity than the latter. Enhancement of the ionic conductivity and the reduction in activation energy seemed to depend on self-heating resulting from the millimeter-wave irradiation. Millimeter-wave irradiation heating restricted the degradation in conductivity accompanying over-substitution, suggesting the optimum structure that provided the maximum conductivity could be different between the two heating methods.

An Analysis of the Impact of Heat Waves in Labor and Crop Productivity in the Agricultural Sector in California

Science.gov (United States)

Castillo, F.; Wehner, M. F.; Gilless, J. K.

2017-12-01

California agriculture is an important economic activity for the state. California leads the nation in farms sales since 1950. In addition, agricultural employment in California reached approximately 410,000. Production of many fruits and vegetables is labor intensive and labor costs represent anywhere from 20% to 40% of total production costs. In additon, agricutlural production growth has been the highest for labor intensive crops such as berries (all types) and nuts. Given the importance of the agricultural sector and the labor component whithin it, the analysis of the impact of climate change on the agricultural sector of California becomes imperative. Heat waves are a weather related extreme that impact labor productivity, specially outdoor labor producitivity. We use crop production function analysis that incorporates socio economic variables such as crop prices, total acreage, production levels and harvest timiline with climate related variables such as an estimated Heat Index (HI) to analize the impact of heat waves on crop production via an impact on labor productivity for selected crops in the Central and Imperial Valleys in California. The analysis finds that the impact of heat waves varies by the degree of labor intensity of the crop and the relative intensity of the heat wave.

Evaluation of major heat waves' mechanisms in EURO-CORDEX RCMs over Central Europe

Science.gov (United States)

Lhotka, Ondřej; Kyselý, Jan; Plavcová, Eva

2018-06-01

The main aim of the study is to evaluate the capability of EURO-CORDEX regional climate models (RCMs) to simulate major heat waves in Central Europe and their associated meteorological factors. Three reference major heat waves (1994, 2006, and 2015) were identified in the E-OBS gridded data set, based on their temperature characteristics, length and spatial extent. Atmospheric circulation, precipitation, net shortwave radiation, and evaporative fraction anomalies during these events were assessed using the ERA-Interim reanalysis. The analogous major heat waves and their links to the aforementioned factors were analysed in an ensemble of EURO-CORDEX RCMs driven by various global climate models in the 1970-2016 period. All three reference major heat waves were associated with favourable circulation conditions, precipitation deficit, reduced evaporative fraction and increased net shortwave radiation. This joint contribution of large-scale circulation and land-atmosphere interactions is simulated with difficulties in majority of the RCMs, which affects the magnitude of modelled major heat waves. In some cases, the seemingly good reproduction of major heat waves' magnitude is erroneously achieved through extremely favourable circulation conditions compensated by a substantial surplus of soil moisture or vice versa. These findings point to different driving mechanisms of major heat waves in some RCMs compared to observations, which should be taken into account when analysing and interpreting future projections of these events.

Slow wave antenna coupling to ion Bernstein waves for plasma heating in ICRF

International Nuclear Information System (INIS)

Sy, W.N-C.; Amano, T.; Ando, R.; Fukuyama, A.; Watari, T.

1984-10-01

The coupling of ICRF power from a slow wave antenna to a plasma with finite temperature is examined theoretically and compared to an independent computer calculation. It is shown that such antennas can be highly efficient in trasferring most of the antenna power directly to ion Bernstein waves, with only a very small fraction going into fast waves. The potentiality of this coupling scheme for plasma heating in ICRF is briefly discussed. (author)

The effect of heat waves, elevated [CO2 ] and low soil water availability on northern red oak (Quercus rubra L.) seedlings.

Science.gov (United States)

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

2013-02-01

The frequency and intensity of heat waves are predicted to increase. This study investigates whether heat waves would have the same impact as a constant increase in temperature with the same heat sum, and whether there would be any interactive effects of elevated [CO2 ] and soil moisture content. We grew Quercus rubra seedlings in treatment chambers maintained at either ambient or elevated [CO2 ] (380 or 700 μmol CO2 mol(-1) ) with temperature treatments of ambient, ambient +3 °C, moderate heat wave (+6 °C every other week) or severe heat wave (+12 °C every fourth week) temperatures. Averaged over a 4-week period, and the entire growing season, the three elevated temperature treatments had the same average temperature and heat sum. Half the seedlings were watered to a soil water content near field capacity, half to about 50% of this value. Foliar gas exchange measurements were performed morning and afternoon (9:00 and 15:00 hours) before, during and after an applied heat wave in August 2010. Biomass accumulation was measured after five heat wave cycles. Under ambient [CO2 ] and well-watered conditions, biomass accumulation was highest in the +3 °C treatment, intermediate in the +6 °C heat wave and lowest in the +12 °C heat wave treatment. This response was mitigated by elevated [CO2 ]. Low soil moisture significantly decreased net photosynthesis (Anet ) and biomass in all [CO2 ] and temperature treatments. The +12 °C heat wave reduced afternoon Anet by 23% in ambient [CO2 ]. Although this reduction was relatively greater under elevated [CO2 ], Anet values during this heat wave were still 34% higher than under ambient [CO2 ]. We concluded that heat waves affected biomass growth differently than the same amount of heat applied uniformly over the growing season, and that the plant response to heat waves also depends on [CO2 ] and soil moisture conditions. © 2012 Blackwell Publishing Ltd.

Heat-related deaths in hot cities: estimates of human tolerance to high temperature thresholds.

Science.gov (United States)

Harlan, Sharon L; Chowell, Gerardo; Yang, Shuo; Petitti, Diana B; Morales Butler, Emmanuel J; Ruddell, Benjamin L; Ruddell, Darren M

2014-03-20

In this study we characterized the relationship between temperature and mortality in central Arizona desert cities that have an extremely hot climate. Relationships between daily maximum apparent temperature (ATmax) and mortality for eight condition-specific causes and all-cause deaths were modeled for all residents and separately for males and females ages heat. For this condition-specific cause of death, the heat thresholds in all gender and age groups (ATmax = 90-97 °F; 32.2-36.1 °C) were below local median seasonal temperatures in the study period (ATmax = 99.5 °F; 37.5 °C). Heat threshold was defined as ATmax at which the mortality ratio begins an exponential upward trend. Thresholds were identified in younger and older females for cardiac disease/stroke mortality (ATmax = 106 and 108 °F; 41.1 and 42.2 °C) with a one-day lag. Thresholds were also identified for mortality from respiratory diseases in older people (ATmax = 109 °F; 42.8 °C) and for all-cause mortality in females (ATmax = 107 °F; 41.7 °C) and males Heat-related mortality in a region that has already made some adaptations to predictable periods of extremely high temperatures suggests that more extensive and targeted heat-adaptation plans for climate change are needed in cities worldwide.

Effect of Latent Heat Released by Freezing Droplets during Frost Wave Propagation.

Science.gov (United States)

Chavan, Shreyas; Park, Deokgeun; Singla, Nitish; Sokalski, Peter; Boyina, Kalyan; Miljkovic, Nenad

2018-05-21

Frost spreads on nonwetting surfaces during condensation frosting via an interdroplet frost wave. When a supercooled condensate water droplet freezes on a hydrophobic or superhydrophobic surface, neighboring droplets still in the liquid phase begin to evaporate. Two possible mechanisms govern the evaporation of neighboring water droplets: (1) The difference in saturation pressure of the water vapor surrounding the liquid and frozen droplets induces a vapor pressure gradient, and (2) the latent heat released by freezing droplets locally heats the substrate, leading to evaporation of nearby droplets. The relative significance of these two mechanisms is still not understood. Here, we study the significance of the latent heat released into the substrate by freezing droplets, and its effect on adjacent droplet evaporation, by studying the dynamics of individual water droplet freezing on aluminum-, copper-, and glass-based hydrophobic and superhydrophobic surfaces. The latent heat flux released into the substrate was calculated from the measured droplet sizes and the respective freezing times ( t f ), defined as the time from initial ice nucleation within the droplet to complete droplet freezing. To probe the effect of latent heat release, we performed three-dimensional transient finite element simulations showing that the transfer of latent heat to neighboring droplets is insignificant and accounts for a negligible fraction of evaporation during microscale frost wave propagation. Furthermore, we studied the effect of substrate thermal conductivity on the transfer of latent heat transfer to neighboring droplets by investigating the velocity of ice bridge formation. The velocity of the ice bridge was independent of the substrate thermal conductivity, indicating that adjacent droplet evaporation during condensation frosting is governed solely by vapor pressure gradients. This study not only provides key insights into the individual droplet freezing process but also

The impact of heat waves on electricity spot markets

International Nuclear Information System (INIS)

Pechan, Anna; Eisenack, Klaus

2014-01-01

Thermoelectric power plants depend on cooling water drawn from water bodies. Low river run-off and/or high water temperatures limit a plant's production capacity. This problem may intensify with climate change. Our study quantifies the impact of forced capacity reductions on market prices, production costs, consumer and producer surplus, as well as emissions by means of a bottom-up power generation system model. First, we simulate the German electricity spot market during the heat wave of 2006. Then we conduct a sensitivity study that accounts for future climatic and technological conditions. We find an average price increase of 11% during the heat wave 2006, which is even more pronounced during times of peak demand. Production costs accumulate to an additional but moderate 16 m. Due to the price increase, producers gain from the heat wave, whereas consumers disproportionately bear the costs. Carbon emissions in the German electricity sector increase during the heat wave. The price and cost effects are more pronounced and increase significantly if assumptions on heat-sensitive demand, hydropower capacity, net exports, and capacity reductions are tightened. These are potential additional effects of climate change. Hence, if mitigation fails or is postponed globally, the impacts on the current energy system are very likely to rise. Increases in feed-in from renewable resources and demand-side management can counter the effects to a considerable degree. Countries with a shift toward a renewable energy supply can be expected to be much less susceptible to cooling water scarcity than those with a high share of nuclear and coal-fired power plants. - Highlights: • We quantify the impact of thermal capacity reductions on the electricity market. • German heat wave 2006 caused moderate rise in production costs. • Capacity reductions have substantial impact on prices and raise producer surplus. • Impacts on prices, production cost and surplus amplify under climate

Impacts of temperature extremes on cardiovascular morbidity and mortality in the Czech Republic

Science.gov (United States)

Davídkovová, H.; Kyselý, J.; Plavcová, E.; Urban, A.; Kriz, B.; Kyncl, J.

2012-04-01

Elevated mortality associated with high ambient temperatures in summer represents one of the main impacts of weather extremes on human society. Increases in cardiovascular mortality during heat waves have been reported in many European countries; much less is known about which particular cardiovascular disorders are most affected during heat waves, and whether similar patterns are found for morbidity (hospital admissions). Relatively less understood is also cold-related mortality and morbidity in winter, when the relationships between weather and human health are more complex, less direct, and confounded by other factors such as epidemics of influenza/acute respiratory infections. The present study analyses relationships between temperature extremes and cardiovascular morbidity and mortality. We make use of the datasets on hospital admissions and daily mortality in the population of the Czech Republic (about 10.3 million) over 1994-2009. The data have been standardized to remove the effects of the long-term trend and the seasonal and weekly cycles. Periods when the morbidity/mortality data were affected by epidemics of influenza and other acute respiratory infections have been removed from the analysis. We use analogous definitions for hot and cold spells based on quantiles of daily average temperature anomalies, which allows for a comparison of the findings for summer hot spells and winter cold spells. The main aims of the study are (i) to identify deviations of mortality and morbidity from the baseline associated with hot and cold spells, (ii) to compare the hot- and cold-spell effects for individual cardiovascular diseases (e.g. ischaemic heart disease I20-I25, cerebrovascular disease I60-I69, hypertension I10, aterosclerosis I70) and to identify those diagnoses that are most closely linked to temperature extremes, (iii) to identify population groups most vulnerable to temperature extremes, and (iv) to compare the links to temperature extremes for morbidity and

Plasma heating by kinetic Alfven wave

International Nuclear Information System (INIS)

Assis, A.S. de.

1982-01-01

The heating of a nonuniform plasma (electron-ion) due to the resonant excitation of the shear Alfven wave in the low β regime is studied using initially the ideal MHD model and posteriorly using the kinetic model. The Vlasov equation for ions and the drift kinetic equation for electrons have been used. Through the ideal MHD model, it is concluded that the energy absorption is due to the continuous spectrum (phase mixing) which the shear Alfven wave has in a nonuniform plasma. An explicit expression for the energy absorption is derived. Through the kinetic model it is concluded that the energy absorption is due to a resonant mode convertion of the incident wave into the kinetic Alfven wave which propagates away from the resonant region. Its electron Landau damping has been observed. There has been a concordance with the MHD calculations. (Author) [pt

A new approach to the theory of heat conduction with finite wave speeds

Directory of Open Access Journals (Sweden)

Vito Antonio Cimmelli

1991-05-01

Full Text Available Relations between the physical models describing the heat conduction in solids and a phenomenological model leading to quasi-linear hyperbolic equations and systems of conservation laws are presented. A new semi-empirical temperature scale is introduced in terms of which a modified Fourier law is formulated. The hyperbolicity of the heat conduction equation is discussed together with some wave propagation problems.

Summer outdoor temperature and occupational heat-related illnesses in Quebec (Canada)

International Nuclear Information System (INIS)

Adam-Poupart, Ariane; Smargiassi, Audrey; Busque, Marc-Antoine; Duguay, Patrice; Fournier, Michel; Zayed, Joseph; Labrèche, France

2014-01-01

Background: Predicted rise in global mean temperature and intensification of heat waves associated with climate change present an increasing challenge for occupational health and safety. Although important scientific knowledge has been gathered on the health effects of heat, very few studies have focused on quantifying the association between outdoor heat and mortality or morbidity among workers. Objective: To quantify the association between occupational heat-related illnesses and exposure to summer outdoor temperatures. Methods: We modeled 259 heat-related illnesses compensated by the Workers' Compensation Board of Quebec between May and September, from 1998 to 2010, with maximum daily summer outdoor temperatures in 16 health regions of Quebec (Canada) using generalized linear models with negative binomial distributions, and estimated the pooled effect sizes for all regions combined, by sex and age groups, and for different time lags with random-effect models for meta-analyses. Results: The mean daily compensation count was 0.13 for all regions of Quebec combined. The relationship between daily counts of compensations and maximum daily temperatures was log-linear; the pooled incidence rate ratio (IRR) of daily heat-related compensations per 1 °C increase in daily maximum temperatures was 1.419 (95% CI 1.326 to 1.520). Associations were similar for men and women and by age groups. Increases in daily maximum temperatures at lags 1 and 2 and for two and three-day lag averages were also associated with increases in daily counts of compensations (IRRs of 1.206 to 1.471 for every 1 °C increase in temperature). Conclusion: This study is the first to quantify the association between occupational heat-related illnesses and exposure to summer temperatures in Canada. The model (risk function) developed in this study could be useful to improve the assessment of future impacts of predicted summer outdoor temperatures on workers and vulnerable groups, particularly in

Summer outdoor temperature and occupational heat-related illnesses in Quebec (Canada)

Energy Technology Data Exchange (ETDEWEB)

Adam-Poupart, Ariane [Department of Environmental and Occupational Health, School of Public Health, Université de Montréal, Montreal, QC (Canada); Smargiassi, Audrey [Department of Environmental and Occupational Health, School of Public Health, Université de Montréal, Montreal, QC (Canada); Institut national de santé publique du Québec (INSPQ), Montreal, QC (Canada); Busque, Marc-Antoine; Duguay, Patrice [Institut de recherche Robert-Sauvé en santé et en sécurité du travail (IRSST), Montreal, QC (Canada); Fournier, Michel [Direction de santé publique, Agence de la santé et des services sociaux de Montréal, Montreal, QC (Canada); Zayed, Joseph [Department of Environmental and Occupational Health, School of Public Health, Université de Montréal, Montreal, QC (Canada); Institut de recherche Robert-Sauvé en santé et en sécurité du travail (IRSST), Montreal, QC (Canada); Labrèche, France, E-mail: labreche.france@irsst.qc.ca [Department of Environmental and Occupational Health, School of Public Health, Université de Montréal, Montreal, QC (Canada); Institut de recherche Robert-Sauvé en santé et en sécurité du travail (IRSST), Montreal, QC (Canada)

2014-10-15

Background: Predicted rise in global mean temperature and intensification of heat waves associated with climate change present an increasing challenge for occupational health and safety. Although important scientific knowledge has been gathered on the health effects of heat, very few studies have focused on quantifying the association between outdoor heat and mortality or morbidity among workers. Objective: To quantify the association between occupational heat-related illnesses and exposure to summer outdoor temperatures. Methods: We modeled 259 heat-related illnesses compensated by the Workers' Compensation Board of Quebec between May and September, from 1998 to 2010, with maximum daily summer outdoor temperatures in 16 health regions of Quebec (Canada) using generalized linear models with negative binomial distributions, and estimated the pooled effect sizes for all regions combined, by sex and age groups, and for different time lags with random-effect models for meta-analyses. Results: The mean daily compensation count was 0.13 for all regions of Quebec combined. The relationship between daily counts of compensations and maximum daily temperatures was log-linear; the pooled incidence rate ratio (IRR) of daily heat-related compensations per 1 °C increase in daily maximum temperatures was 1.419 (95% CI 1.326 to 1.520). Associations were similar for men and women and by age groups. Increases in daily maximum temperatures at lags 1 and 2 and for two and three-day lag averages were also associated with increases in daily counts of compensations (IRRs of 1.206 to 1.471 for every 1 °C increase in temperature). Conclusion: This study is the first to quantify the association between occupational heat-related illnesses and exposure to summer temperatures in Canada. The model (risk function) developed in this study could be useful to improve the assessment of future impacts of predicted summer outdoor temperatures on workers and vulnerable groups, particularly in

Attributing anthropogenic impact on regional heat wave events using CAM5 model large ensemble simulations

Science.gov (United States)

Lo, S. H.; Chen, C. T.

2017-12-01

Extreme heat waves have serious impacts on society. It was argued that the anthropogenic forcing might substantially increase the risk of extreme heat wave events (e.g. over western Europe in 2003 and over Russia in 2010). However, the regional dependence of such anthropogenic impact and the sensitivity of the attributed risk to the definition of heat wave still require further studies. In our research framework, the change in the frequency and severity of a heat wave event under current conditions is calculated and compared with the probability and magnitude of the event if the effects of particular external forcing, such as due to human influence, had been absent. In our research, we use the CAM5 large ensemble simulation from the CLIVAR C20C+ Detection and Attribution project (http://portal.nersc.gov/c20c/main.html, Folland et al. 2014) to detect the heat wave events occurred in both historical all forcing run and natural forcing only run. The heat wave events are identified by partial duration series method (Huth et al., 2000). We test the sensitivity of heat wave thresholds from daily maximum temperature (Tmax) in warm season (from May to September) between 1959 and 2013. We consider the anthropogenic effect on the later period (2000-2013) when the warming due to human impact is more evident. Using Taiwan and surrounding area as our preliminary research target, We found the anthropogenic effect will increase the heat wave day per year from 30 days to 75 days and make the mean starting(ending) day for heat waves events about 15-30 days earlier(later). Using the Fraction of Attribution Risk analysis to estimate the risk of frequency of heat wave day, our results show the anthropogenic forcing very likely increase the heat wave days over Taiwan by more than 50%. Further regional differences and sensitivity of the attributed risk to the definition of heat wave will be compared and discussed.

Impacts of urban growth and heat waves events on the urban heat island in Bucharest city

Science.gov (United States)

Zoran, Maria A.; Savastru, Roxana S.; Savastru, Dan M.; Dida, Adrian I.

2016-10-01

This study investigated the influences of urban growth and heat waves events on Urban Heat Island in relationship with several biophysical variables in Bucharest metropolitan area of Romania through satellite and in-situ monitoring data. Remote sensing data from Landsat TM/ETM+ and time series MODIS Terra/Aqua sensors have been used to assess urban land cover- temperature interactions over period between 2000 and 2016 years. Vegetation abundances and percent impervious surfaces were derived by means of linear spectral mixture model, and a method for effectively enhancing impervious surface has been developed to accurately examine the urban growth. The land surface temperature (Ts), a key parameter for urban thermal characteristics analysis, was also analyzed in relation with the Normalized Difference Vegetation Index (NDVI) at city level. Based on these parameters, the urban growth, urban heat island effect (UHI) and the relationships of Ts to other biophysical parameters (surface albedo, precipitations, wind intensity and direction) have been analyzed. Results show that in the metropolitan area ratio of impervious surface in Bucharest increased significantly during investigated period, the intensity of urban heat island and heat wave events being most significant. The correlation analyses revealed that, at the pixel-scale, Ts possessed a strong positive correlation with percent impervious surfaces and negative correlation with vegetation abundances at the regional scale, respectively. This analysis provided an integrated research scheme and the findings can be very useful for urban ecosystem modeling.

Computational exploration of wave propagation and heating from transcranial focused ultrasound for neuromodulation

Science.gov (United States)

Mueller, Jerel K.; Ai, Leo; Bansal, Priya; Legon, Wynn

2016-10-01

Objective. While ultrasound is largely established for use in diagnostic imaging, its application for neuromodulation is relatively new and crudely understood. The objective of the present study was to investigate the effects of tissue properties and geometry on the wave propagation and heating in the context of transcranial neuromodulation. Approach. A computational model of transcranial-focused ultrasound was constructed and validated against empirical data. The models were then incrementally extended to investigate a number of issues related to the use of ultrasound for neuromodulation, including the effect on wave propagation of variations in geometry of skull and gyral anatomy as well as the effect of multiple tissue and media layers, including scalp, skull, CSF, and gray/white matter. In addition, a sensitivity analysis was run to characterize the influence of acoustic properties of intracranial tissues. Finally, the heating associated with ultrasonic stimulation waveforms designed for neuromodulation was modeled. Main results. The wave propagation of a transcranially focused ultrasound beam is significantly influenced by the cranial domain. The half maximum acoustic beam intensity profiles are insensitive overall to small changes in material properties, though the inclusion of sulci in models results in greater peak intensity values compared to a model without sulci (1%-30% greater). Finally, heating using currently employed stimulation parameters in humans is highest in bone (0.16 °C) and is negligible in brain (4.27 × 10-3 °C) for a 0.5 s exposure. Significance. Ultrasound for noninvasive neuromodulation holds great promise and appeal for its non-invasiveness, high spatial resolution and deep focal lengths. Here we show gross brain anatomy and biological material properties to have limited effect on ultrasound wave propagation and to result in safe heating levels in the skull and brain.

Wave Heating of the Solar Chromosphere Wolfgang Kalkofen

Indian Academy of Sciences (India)

Abstract. The nonmagnetic interior of supergranulation cells has been thought since the 1940s to be heated by the dissipation of acoustic waves. But all attempts to measure the acoustic flux have failed to show suffi- cient energy for chromospheric heating. Recent space observations with. TRACE, for example, have found ...

Mapping heat wave risk in the UK: Proactive planning for the 2050s

Science.gov (United States)

Oven, Katie; Reaney, Sim; Ohlemüller, Ralf; Nodwell, Sarah; Curtis, Sarah; Riva, Mylène; Dunn, Christine; Val, Dimitri; Burkhard, Roland

2010-05-01

Climate change projections suggest an increased frequency of heat waves in the UK over the coming decades. Such extreme events pose a serious threat to human health and are likely to impact upon health and social care systems and the infrastructures supporting them. This stress will result from both increased demands upon healthcare services and the ability of the infrastructure to cope, such as sufficient climate control in hospitals. Certain sectors of the population, such as older people, have an increased susceptibility to heat waves and hence are the focus of this research. There is no universal definition of a heat wave, reflecting the acclimatisation of a population. Based on a review of the literature, this research therefore sets out a series of working definitions of a heat wave in the UK context from a human health perspective. Drawing on these definitions, the UK heat wave hazard was mapped for the 2050s (2040-2069) using daily minimum and maximum temperature data derived from the UKCP09 Weather Generator at 50 km resolution. The analysis was undertaken for the three different greenhouse gas emissions scenarios within UKCP09 (low, medium and high). Hot spots of increased heat wave risk were identified and comparisons made between the various model outputs. These data were then combined with demographic forecasts for the 2050s enabling the identification of areas with an ageing population. Results are presented showing the scale of the projected change in heat wave risk across the UK and the location of older people. These results will be used in proactive planning to help policymakers and practitioners respond more appropriately to the needs of vulnerable populations in the coming decades. Key words: climate change; heat wave; risk mapping; vulnerability; risk reduction.

Wave trajectory and electron cyclotron heating in toroidal plasmas

International Nuclear Information System (INIS)

Maekawa, T.; Tanaka, S.; Terumichi, Y.; Hamada, Y.

1977-12-01

Wave trajectories propagating obliquely to magnetic field in toroidal plasmas are studied theoretically. Results show that the ordinary wave at appropriate incident angle is mode-converted to the extraordinary wave at first turning point and is further converted to the electron Bernstein wave during passing a loop or a hooked nail curve near second turning point and is cyclotron-damped away, resulting in local electron heating, before arriving at cyclotron resonance layer. (auth.)

Full-wave and Fokker Planck analysis of ICRF heating experiments in the Alcator C-Mod tokamak

International Nuclear Information System (INIS)

Bonoli, P.T.; Golovato, S.; Porkolab, M.; Takase, Y.

1996-01-01

The Alcator C-Mod device is a high field, high density, shaped tokamak with parameters a = 0.22 m, R 0 = 0.67 m, B 0 ≤ 9.0 T, κ ≤ 1.8, δ ≤ 0.8, and 1.0 x 10 20 m -3 n e (0) ≤ 1.0 x 10 21 m -3 . Four megawatt of ICRF power is available at 80 MHz. The wide operating range in magnetic field makes several heating schemes possible: (i) Second harmonic heating of hydrogen (f 0 = 2f CH ) at 2.6 T in (D-H); (ii) Fundamental heating of (H) (f 0 = f CH ) at 5.3T in a D-(H) plasma; and (iii) Fundamental heating of ( 3 He) (f 0 = f C 3 He ) at 7.9 T in a D-( 3 He) plasma. The most successful heating regime to date has been (H)-minority heating at 5.3 T. Pellet enhanced performance (PEP) modes have also been achieved in C-Mod in D-(H) at 5.3 T and in D-( 3 He) at 7.9 T, with a combination of intense ICRF heating and Li-pellet injection. A variety of numerical models are used to analyze these heating schemes. A 1-D full-wave code (FELICE) is used to study open-quotes single passclose quotes damping of the ICRF wavefront and damping of mode-converted ion Bernstein waves. A toroidal full-wave code (FISIC) is used to study interference and focussing effects of the ICRF waves as well as damping of the ICRF power upon multiple passes of the ICRF wavefront. A combined bounce averaged Fokker Planck and toroidal full-wave code (FPPRF) is used to study the ion tail formation, orbit losses, and the power partition of the ICRF tail to the background electrons and ions. Full-wave and Fokker Planck analyses confirm the strong single pass absorption of the ICRF power in D-(H) at 5.3 T. Analysis of PEP-mode plasmas in D-( 3 He) indicates improved wave focussing and 3 He-cyclotron absorption of the ICRF waves relative to L-mode. A dramatic increase in the transfer of 3 He tail power to the background deuterium is also found for PEP-mode plasmas

Adaptation to Climate Change: A Comparative Analysis of Modeling Methods for Heat-Related Mortality.

Science.gov (United States)

Gosling, Simon N; Hondula, David M; Bunker, Aditi; Ibarreta, Dolores; Liu, Junguo; Zhang, Xinxin; Sauerborn, Rainer

2017-08-16

Multiple methods are employed for modeling adaptation when projecting the impact of climate change on heat-related mortality. The sensitivity of impacts to each is unknown because they have never been systematically compared. In addition, little is known about the relative sensitivity of impacts to "adaptation uncertainty" (i.e., the inclusion/exclusion of adaptation modeling) relative to using multiple climate models and emissions scenarios. This study had three aims: a ) Compare the range in projected impacts that arises from using different adaptation modeling methods; b ) compare the range in impacts that arises from adaptation uncertainty with ranges from using multiple climate models and emissions scenarios; c ) recommend modeling method(s) to use in future impact assessments. We estimated impacts for 2070-2099 for 14 European cities, applying six different methods for modeling adaptation; we also estimated impacts with five climate models run under two emissions scenarios to explore the relative effects of climate modeling and emissions uncertainty. The range of the difference (percent) in impacts between including and excluding adaptation, irrespective of climate modeling and emissions uncertainty, can be as low as 28% with one method and up to 103% with another (mean across 14 cities). In 13 of 14 cities, the ranges in projected impacts due to adaptation uncertainty are larger than those associated with climate modeling and emissions uncertainty. Researchers should carefully consider how to model adaptation because it is a source of uncertainty that can be greater than the uncertainty in emissions and climate modeling. We recommend absolute threshold shifts and reductions in slope. https://doi.org/10.1289/EHP634.

Projection of heat waves over China for eight different global warming targets using 12 CMIP5 models

Science.gov (United States)

Guo, Xiaojun; Huang, Jianbin; Luo, Yong; Zhao, Zongci; Xu, Ying

2017-05-01

Simulation and projection of the characteristics of heat waves over China were investigated using 12 CMIP5 global climate models and the CN05.1 observational gridded dataset. Four heat wave indices (heat wave frequency, longest heat wave duration, heat wave days, and high temperature days) were adopted in the analysis. Evaluations of the 12 CMIP5 models and their ensemble indicated that the multi-model ensemble could capture the spatiotemporal characteristics of heat wave variation over China. The inter-decadal variations of heat waves during 1961-2005 can be well simulated by multi-model ensemble. Based on model projections, the features of heat waves over China for eight different global warming targets (1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, and 5.0 °C) were explored. The results showed that the frequency and intensity of heat waves would increase more dramatically as the global mean temperature rise attained higher warming targets. Under the RCP8.5 scenario, the four China-averaged heat wave indices would increase from about 1.0 times/year, 2.5, 5.4, and 13.8 days/year to about 3.2 times/year, 14.0, 32.0, and 31.9 days/year for 1.5 and 5.0 °C warming targets, respectively. Those regions that suffer severe heat waves in the base climate would experience the heat waves with greater frequency and severity following global temperature rise. It is also noteworthy that the areas in which a greater number of severe heat waves occur displayed considerable expansion. Moreover, the model uncertainties exhibit a gradual enhancement with projected time extending from 2006 to 2099.

Efficient heat generation in large-area graphene films by electromagnetic wave absorption

Science.gov (United States)

Kang, Sangmin; Choi, Haehyun; Lee, Soo Bin; Park, Seong Chae; Park, Jong Bo; Lee, Sangkyu; Kim, Youngsoo; Hong, Byung Hee

2017-06-01

Graphene has been intensively studied due to its outstanding electrical and thermal properties. Recently, it was found that the heat generation by Joule heating of graphene is limited by the conductivity of graphene. Here we suggest an alternative method to generate heat on a large-area graphene film more efficiently by utilizing the unique electromagnetic (EM) wave absorption property of graphene. The EM wave induces an oscillating magnetic moment generated by the orbital motion of moving electrons, which efficiently absorbs the EM energy and dissipate it as a thermal energy. In this case, the mobility of electron is more important than the conductivity, because the EM-induced diamagnetic moment is directly proportional to the speed of electron in an orbital motion. To control the charge carrier mobility of graphene we functionalized substrates with self-assembled monolayers (SAM). As the result, we find that the graphene showing the Dirac voltage close to zero can be more efficiently heated by EM waves. In addition, the temperature gradient also depends on the number of graphene. We expect that the efficient and fast heating of graphene films by EM waves can be utilized for smart heating windows and defogging windshields.

Factors contributing to record-breaking heat waves over the Great Plains during the 1930s Dust Bowl

Science.gov (United States)

Cowan, T.; Hegerl, G. C.

2016-12-01

Record-breaking summer heat waves that plagued contiguous United States in the 1930s emerged during the decade-long "Dust Bowl" drought. Using high-quality daily temperature observations, the Dust Bowl heat wave characteristics for the Great Plains are assessed using metrics that describe variations in heat wave activity and intensity. We also quantify record-breaking heat waves over the pre-industrial period for 22 CMIP5 model multi-century realisations. The most extreme Great Plains heat wave summers in the Dust Bowl decade (e.g. 1931, 1934, 1936) were pre-conditioned by anomalously dry springs, as measured by proxy drought indices. In general, summer heat waves over the Great Plains develop 15-20 days earlier after anomalously dry springs, and are also significantly longer and hotter, indicative of the importance of land surface feedbacks in heat wave intensification. The majority of pre-industrial climate model experiments capture regionally clustered summer heat waves across North America, although the North Pacific and Atlantic sea surface temperature patterns associated with the heat waves vary considerably between models. Sea surface temperature patterns may be more important for influencing winter and spring precipitation, thus amplifying summer heat waves during drought periods. The synoptic pattern that commonly appeared during the exceptional Dust Bowl heat waves featured an anomalous broad surface pressure ridge straddling an upper level blocking anticyclone over the western United States. This forced significant subsidence and adiabatic warming over the Great Plains, and triggered anomalous southward warm advection over southern regions, prolonging and amplifying the heat waves over central United States. Importantly, the results show that despite the sparsity of stations in the 1930s, homogeneous observations are crucial in accurately quantifying the Dust Bowl decade heat waves, as opposed to solely relying on atmospheric reanalysis.

HIGH IMPACT HEAT WAVES OVER THE EURO-MEDITERRANEAN REGION AND TURKEY - IN CONCERT WITH ATMOSPHERIC BLOCKING AND LARGE DYNAMICAL AND PHYSICAL ANOMALIES

Directory of Open Access Journals (Sweden)

Meral Demirtaş

2017-03-01

Full Text Available The increase in high impact heat waves in the Euro-Mediterranean region and Turkey is related to a number of concurring factors that include the persistent anticyclonic weather regimes. The present study investigates the June-July-August (JJA of 2000, 2007 and 2010 heat wave events in concert with some meteorological anomalies (the 500 hPa geopotential height, 850 hPa temperature, sea surface temperature and soil wetness and blocking anticyclones, focusing on heat wave occurrences on a grid point base. Detection methods for atmospheric blocking and heat wave are introduced and applied for the mentioned years. During the 2000 JJA very high temperatures were recorded over the Balkan Peninsula and in Turkey where 42 cities had breaking all time highest temperature records for June, but the duration of heat wave was the shortest. The 2007 summer was also abnormally hot for the region and record breaking temperatures were observed in Greece, Romania, Bulgaria and Turkey where 34 cities had highest temperature records for June and July, and the highest total heat wave duration was 60-70 days. The 2010 JJA period was extremely hot over Russia and nearby countries including Turkey where 9 cities had highest temperature records for August. The 2010 case was marked for; large anomalies, the longest heat wave duration and the highest heat wave intensity. In all cases, heat wave occurrences found to be particularly high over the western part of Turkey. The abnormally hot summers of 2000, 2007 and 2010 could reflect summers to come. The results indicate that summer climate might experience a pronounced increase in year-to-year variability. Increase in variability might be able to explain the high impact heat waves, and would strongly affect their incidence in the future. The results may also contribute to a better understanding of heat waves in context of climate variability.

Heat-flow equation motivated by the ideal-gas shock wave.

Science.gov (United States)

Holian, Brad Lee; Mareschal, Michel

2010-08-01

We present an equation for the heat-flux vector that goes beyond Fourier's Law of heat conduction, in order to model shockwave propagation in gases. Our approach is motivated by the observation of a disequilibrium among the three components of temperature, namely, the difference between the temperature component in the direction of a planar shock wave, versus those in the transverse directions. This difference is most prominent near the shock front. We test our heat-flow equation for the case of strong shock waves in the ideal gas, which has been studied in the past and compared to Navier-Stokes solutions. The new heat-flow treatment improves the agreement with nonequilibrium molecular-dynamics simulations of hard spheres under strong shockwave conditions.

Two-dimensional nonlinear heat conduction wave in a layer-inhomogeneous medium and the characteristics of heat transfer in laser thermonuclear fusion targets

International Nuclear Information System (INIS)

Gus'kov, Sergei Yu; Doskach, I Ya

1999-01-01

An analytical solution is obtained to the problem of propagation of a 2-D nonlinear heat conduction wave from a cylindrical energy source, which acts in a planar layer of a material surrounded by a medium with different mass density and degree of ionisation. A theoretical justification is given of several interesting phenomena of 2-D thermal wave propagation through an inhomogeneous medium. These phenomena are related to the difference between the thermal wave velocities in the media with different thermal diffusivities. When the mass density in a layer experiencing the action of an energy source exceeds the density of the surrounding medium, the thermal wave front is shown to glide along the layer boundaries with a spatial velocity exceeding the velocity of the wave inside the layer. Moreover, there is a possibility of 'themal flow' of a layer across the boundaries between the layer and the surrounding medium in front of a thermal wave propagating inside the layer. The problems of heat transfer in multilayer targets for laser thermonuclear fusion are considered as an application. (interaction of laser radiation with matter. laser plasma)

Heat wave experiments on the W7-AS stellarator

International Nuclear Information System (INIS)

Hartfuss, H.J.; Erckmann, V.; Gasparino, U.; Giannone, L.; Maassberg, H.; Tutter, M.

1993-01-01

Power modulation with well localized ECRH power deposition at both 70 and 140 GHz, has been used to generate temperature perturbations which propagate away from the deposition region. Radiometry of the ECE is used to diagnose the generated temperature perturbation as a function of distance to the deposition zone. The decay of the amplitude and the delay of the wave provide the information to determine the electron thermal diffusivity. This value is then compared with the one derived from a global power balance. It is found that both values agree with the error bars. The technique has also been applied in recent experiments during L-H-mode transitions in W7-AS demonstrating a significant reduction in the effective heat diffusivity in the plasma core during the H-phase. The modulated ECRH causes a modulation of the Shafranov shift. Interference of the prompt shift with the heat wave results in an apparent asymmetry of the decay length of the heat wave with respect to the plasma centre. (orig.)

Stressful social relations and mortality

DEFF Research Database (Denmark)

Lund, Rikke; Christensen, Ulla; Nilsson, Charlotte Juul

2014-01-01

BACKGROUND: Few studies have examined the relationship between stressful social relations in private life and all-cause mortality. OBJECTIVE: To evaluate the association between stressful social relations (with partner, children, other family, friends and neighbours, respectively) and all...... men and women aged 36-52 years, linked to the Danish Cause of Death Registry for information on all-cause mortality until 31 December 2011. Associations between stressful social relations with partner, children, other family, friends and neighbours, respectively, and all-cause mortality were examined....... CONCLUSIONS: Stressful social relations are associated with increased mortality risk among middle-aged men and women for a variety of different social roles. Those outside the labour force and men seem especially vulnerable to exposure....

Quantifying Projected Heat Mortality Impacts under 21st-Century Warming Conditions for Selected European Countries.

Science.gov (United States)

Kendrovski, Vladimir; Baccini, Michela; Martinez, Gerardo Sanchez; Wolf, Tanja; Paunovic, Elizabet; Menne, Bettina

2017-07-05

Under future warming conditions, high ambient temperatures will have a significant impact on population health in Europe. The aim of this paper is to quantify the possible future impact of heat on population mortality in European countries, under different climate change scenarios. We combined the heat-mortality function estimated from historical data with meteorological projections for the future time laps 2035-2064 and 2071-2099, developed under the Representative Concentration Pathways (RCP) 4.5 and 8.5. We calculated attributable deaths (AD) at the country level. Overall, the expected impacts will be much larger than the impacts we would observe if apparent temperatures would remain in the future at the observed historical levels. During the period 2071-2099, an overall excess of 46,690 and 117,333 AD per year is expected under the RCP 4.5 and RCP 8.5 scenarios respectively, in addition to the 16,303 AD estimated under the historical scenario. Mediterranean and Eastern European countries will be the most affected by heat, but a non-negligible impact will be still registered in North-continental countries. Policies and plans for heat mitigation and adaptation are needed and urgent in European countries in order to prevent the expected increase of heat-related deaths in the coming decades.

Heat-Related Deaths in Hot Cities: Estimates of Human Tolerance to High Temperature Thresholds

Directory of Open Access Journals (Sweden)

Sharon L. Harlan

2014-03-01

Full Text Available In this study we characterized the relationship between temperature and mortality in central Arizona desert cities that have an extremely hot climate. Relationships between daily maximum apparent temperature (ATmax and mortality for eight condition-specific causes and all-cause deaths were modeled for all residents and separately for males and females ages <65 and ≥65 during the months May–October for years 2000–2008. The most robust relationship was between ATmax on day of death and mortality from direct exposure to high environmental heat. For this condition-specific cause of death, the heat thresholds in all gender and age groups (ATmax = 90–97 °F; 32.2‒36.1 °C were below local median seasonal temperatures in the study period (ATmax = 99.5 °F; 37.5 °C. Heat threshold was defined as ATmax at which the mortality ratio begins an exponential upward trend. Thresholds were identified in younger and older females for cardiac disease/stroke mortality (ATmax = 106 and 108 °F; 41.1 and 42.2 °C with a one-day lag. Thresholds were also identified for mortality from respiratory diseases in older people (ATmax = 109 °F; 42.8 °C and for all-cause mortality in females (ATmax = 107 °F; 41.7 °C and males <65 years (ATmax = 102 °F; 38.9 °C. Heat-related mortality in a region that has already made some adaptations to predictable periods of extremely high temperatures suggests that more extensive and targeted heat-adaptation plans for climate change are needed in cities worldwide.

Exploration of high harmonic fast wave heating on the National Spherical Torus Experiment

International Nuclear Information System (INIS)

Wilson, J.R.; Bell, R.E.; Bernabei, S.; Bitter, M.; Gates, D.; Hosea, J.; Le Blanc, B.; Medley, S.; Menard, J.; Mueller, D.; Ono, M.; Phillips, C.K.; Rosenberg, A.; Bonoli, P.; Mau, T.K.; Pinsker, R.I.; Raman, R.; Ryan, P.; Swain, D.; Wilgen, J.

2003-01-01

High harmonic fast wave (HHFW) heating has been proposed as a particularly attractive means for plasma heating and current drive in the high beta plasmas that are achievable in spherical torus (ST) devices. The National Spherical Torus Experiment (NSTX) [M. Ono, S. M. Kaye, S. Neumeyer et al., in Proceedings of the 18th IEEE/NPSS Symposium on Fusion Engineering, Albuquerque, 1999 (IEEE, Piscataway, NJ, 1999), p. 53] is such a device. An rf heating system has been installed on the NSTX to explore the physics of HHFW heating, current drive via rf waves and for use as a tool to demonstrate the attractiveness of the ST concept as a fusion device. To date, experiments have demonstrated many of the theoretical predictions for HHFW. In particular, strong wave absorption on electrons over a wide range of plasma parameters and wave parallel phase velocities, wave acceleration of energetic ions, and indications of current drive for directed wave spectra have been observed. In addition HHFW heating has been used to explore the energy transport properties of NSTX plasmas, to create H-mode discharges with a large fraction of bootstrap current and to control the plasma current profile during the early stages of the discharge

Exploration of High Harmonic Fast Wave Heating on the National Spherical Torus Experiment

International Nuclear Information System (INIS)

Wilson, J.R.; Bell, R.E.; Bernabei, S.; Bitter, M.; Bonoli, P.; Gates, D.; Hosea, J.; LeBlanc, B.; Mau, T.K.; Medley, S.; Menard, J.; Mueller, D.; Ono, M.; Phillips, C.K.; Pinsker, R.I.; Raman, R.; Rosenberg, A.; Ryan, P.; Sabbagh, S.; Stutman, D.; Swain, D.; Takase, Y.; Wilgen, J.

2003-01-01

High Harmonic Fast Wave (HHFW) heating has been proposed as a particularly attractive means for plasma heating and current drive in the high-beta plasmas that are achievable in spherical torus (ST) devices. The National Spherical Torus Experiment (NSTX) [Ono, M., Kaye, S.M., Neumeyer, S., et al., Proceedings, 18th IEEE/NPSS Symposium on Fusion Engineering, Albuquerque, 1999, (IEEE, Piscataway, NJ (1999), p. 53.)] is such a device. An radio-frequency (rf) heating system has been installed on NSTX to explore the physics of HHFW heating, current drive via rf waves and for use as a tool to demonstrate the attractiveness of the ST concept as a fusion device. To date, experiments have demonstrated many of the theoretical predictions for HHFW. In particular, strong wave absorption on electrons over a wide range of plasma parameters and wave parallel phase velocities, wave acceleration of energetic ions, and indications of current drive for directed wave spectra have been observed. In addition HHFW heating has been used to explore the energy transport properties of NSTX plasmas, to create H-mode (high-confinement mode) discharges with a large fraction of bootstrap current and to control the plasma current profile during the early stages of the discharge

The temporal behaviour of MHD waves in a partially ionized prominence-like plasma: Effect of heating and cooling

Science.gov (United States)

Ballester, J. L.; Carbonell, M.; Soler, R.; Terradas, J.

2018-01-01

Context. During heating or cooling processes in prominences, the plasma microscopic parameters are modified due to the change of temperature and ionization degree. Furthermore, if waves are excited on this non-stationary plasma, the changing physical conditions of the plasma also affect wave dynamics. Aims: Our aim is to study how temporal variation of temperature and microscopic plasma parameters modify the behaviour of magnetohydrodynamic (MHD) waves excited in a prominence-like hydrogen plasma. Methods: Assuming optically thin radiation, a constant external heating, the full expression of specific internal energy, and a suitable energy equation, we have derived the profiles for the temporal variation of the background temperature. We have computed the variation of the ionization degree using a Saha equation, and have linearized the single-fluid MHD equations to study the temporal behaviour of MHD waves. Results: For all the MHD waves considered, the period and damping time become time dependent. In the case of Alfvén waves, the cut-off wavenumbers also become time dependent and the attenuation rate is completely different in a cooling or heating process. In the case of slow waves, while it is difficult to distinguish the slow wave properties in a cooling partially ionized plasma from those in an almost fully ionized plasma, the period and damping time of these waves in both plasmas are completely different when the plasma is heated. The temporal behaviour of the Alfvén and fast wave is very similar in the cooling case, but in the heating case, an important difference appears that is related with the time damping. Conclusions: Our results point out important differences in the behaviour of MHD waves when the plasma is heated or cooled, and show that a correct interpretation of the observed prominence oscillations is very important in order to put accurate constraints on the physical situation of the prominence plasma under study, that is, to perform prominence

Preferential heating of oxygen 5{sup +} ions by finite-amplitude oblique Alfvén waves

Energy Technology Data Exchange (ETDEWEB)

Maneva, Yana G.; Poedts, Stefaan [Centre for mathematical Plasma Astrophysics, KU Leuven, B-3001 Leuven (Belgium); Viñas, Adolfo [NASA Goddard Space Flight Center, Heliophysics Science Division, Greenbelt, 20771 MD (United States); Araneda, Jaime [Departamento de Física, Universidad de Concepción, Casilla 160 - C, Concepción (Chile)

2016-03-25

Minor ions in the fast solar wind are known to have higher temperatures and to flow faster than protons in the interplanetary space. In this study we combine previous research on parametric instability theory and 2.5D hybrid simulations to study the onset of preferential heating of Oxygen 5{sup +} ions by large-scale finite-amplitude Alfvén waves in the collisionless fast solar wind. We consider initially non-drifting isotropic multi-species plasma, consisting of isothermal massless fluid electrons, kinetic protons and kinetic Oxygen 5{sup +} ions. The external energy source for the plasma heating and energization are oblique monochromatic Alfvén-cyclotron waves. The waves have been created by rotating the direction of initial parallel pump, which is a solution of the multi-fluid plasma dispersion relation. We consider propagation angles θ ≤ 30°. The obliquely propagating Alfvén pump waves lead to strong diffusion in the ion phase space, resulting in highly anisotropic heavy ion velocity distribution functions and proton beams. We discuss the application of the model to the problems of preferential heating of minor ions in the solar corona and the fast solar wind.

Individual and Public-Program Adaptation: Coping with Heat Waves in Five Cities in Canada

Directory of Open Access Journals (Sweden)

Mustapha Alhassan

2011-12-01

Full Text Available Heat Alert and Response Systems (HARS are currently undergoing testing and implementation in Canada. These programs seek to reduce the adverse health effects of heat waves on human health by issuing weather forecasts and warnings, informing individuals about possible protections from excessive heat, and providing such protections to vulnerable subpopulations and individuals at risk. For these programs to be designed effectively, it is important to know how individuals perceive the heat, what their experience with heat-related illness is, how they protect themselves from excessive heat, and how they acquire information about such protections. In September 2010, we conducted a survey of households in 5 cities in Canada to study these issues. At the time of the survey, these cities had not implemented heat outreach and response systems. The study results indicate that individuals’ recollections of recent heat wave events were generally accurate. About 21% of the sample reported feeling unwell during the most recent heat spell, but these illnesses were generally minor. Only in 25 cases out of 243, these illnesses were confirmed or diagnosed by a health care professional. The rate at which our respondents reported heat-related illnesses was higher among those with cardiovascular and respiratory illnesses, was higher among younger respondents and bore no relationship with the availability of air conditioning at home. Most of the respondents indicated that they would not dismiss themselves as “not at risk” and that they would cope with excessive heat by staying in air conditioned environments and keeping well hydrated. Despite the absence of heat outreach and education programs in their city, our respondents at least a rough idea of how to take care of themselves. The presence of air conditioning and knowledge of cooling centers is location-specific, which provides opportunities for targeting HARS interventions.

Individual and public-program adaptation: coping with heat waves in five cities in Canada.

Science.gov (United States)

Alberini, Anna; Gans, Will; Alhassan, Mustapha

2011-12-01

Heat Alert and Response Systems (HARS) are currently undergoing testing and implementation in Canada. These programs seek to reduce the adverse health effects of heat waves on human health by issuing weather forecasts and warnings, informing individuals about possible protections from excessive heat, and providing such protections to vulnerable subpopulations and individuals at risk. For these programs to be designed effectively, it is important to know how individuals perceive the heat, what their experience with heat-related illness is, how they protect themselves from excessive heat, and how they acquire information about such protections. In September 2010, we conducted a survey of households in 5 cities in Canada to study these issues. At the time of the survey, these cities had not implemented heat outreach and response systems. The study results indicate that individuals' recollections of recent heat wave events were generally accurate. About 21% of the sample reported feeling unwell during the most recent heat spell, but these illnesses were generally minor. Only in 25 cases out of 243, these illnesses were confirmed or diagnosed by a health care professional. The rate at which our respondents reported heat-related illnesses was higher among those with cardiovascular and respiratory illnesses, was higher among younger respondents and bore no relationship with the availability of air conditioning at home. Most of the respondents indicated that they would not dismiss themselves as "not at risk" and that they would cope with excessive heat by staying in air conditioned environments and keeping well hydrated. Despite the absence of heat outreach and education programs in their city, our respondents at least a rough idea of how to take care of themselves. The presence of air conditioning and knowledge of cooling centers is location-specific, which provides opportunities for targeting HARS interventions.

Electron thermal conductivity from heat wave propagation in Wendelstein 7-AS

Energy Technology Data Exchange (ETDEWEB)

Giannone, L.; Erckmann, V; Gasparino, U; Hartfuss, H J; Kuehner, G; Maassberg, H; Stroth, U; Tutter, M [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); W7-AS Team; ECRH Group IPF Stuttgart; Gyrotron Group KFK Karlsruhe

1992-11-01

Heat wave propagation experiments have been carried out on the Wendelstein 7-AS stellarator. The deposition of electron cyclotron resonance heating power is highly localized in the plasma centre, so that power modulation produces heat waves which propagate away from the deposition volume. Radiometry of the electron cyclotron emission is used to measure the generated temperature perturbation. The propagation time delay of the temperature perturbation as a function of distance to the power deposition region is used to determine the electron thermal conductivity [chi][sub e]. This value is then compared with the value determined by global power balance. In contrast to sawtooth propagation experiments in tokamaks, it is found that the value of [chi][sub e] from heat wave propagation is comparable to that calculated by power balance. In addition, inward propagating waves were produced by choosing a power deposition region away from the plasma centre. Experiments were carried out at 70 GHz in the ordinary mode and at 140 GHz in the extraordinary mode. Variations of the modulation power amplitude have demonstrated that the inferred value of [chi][sub e] is independent of the amplitude of the induced temperature perturbations. (author). 29 refs, 11 figs, 5 tabs.

Thermotolerance and Photosystem II Behaviour in Co-occuring Temperate Tree Species Exposed to Short-term Extreme Heat Waves

Science.gov (United States)

Guha, A.; Warren, J.; Cummings, C.; Han, J.

2017-12-01

Thermal stress can induce irreversible photodamage with longer consequences for plant metabolism. We focused on photosystem II (PSII) behaviour to understand how this complex responds in different co-occuring temperate trees exposed to short-term extreme heat waves. The study was designed for understanding complex heat tolerance mechanisms in trees. During manipulative heat-wave experiments, we monitored instantaneous PSII performance and tracked both transient and chronic PSII damages using chlorophyll a fluorescence characteristics. Fluorescence signals were used to simulate PSII bioenergetic processes. The light (Fv'/Fm') and dark-adapted (Fv/Fm) fluorescence traits including fast induction kinetics (OJIP), electron transport rate, PSII operating efficiency and quenching capacities were significantly affected by the heat treatments. Loss in PSII efficiency was more apparent in species like black cottonwood, yellow poplar, walnuts and conifers, whereas oaks maintained relatively better PSII functions. The post-heat recovery of Fv/Fm varied across the studied species showing differential carry over effects. PSII down-regulation was one of dominant factors for the loss in operational photosynthesis during extreme heat wave events. Both light and dark-adapted fluorescence characteristics showed loss in photo-regulatory functions and photodamage. Some resilient species showed rapid recovery from transient PSII damage, whereas fingerprints of chronic PSII damage were observed in susceptibles. Thresholds for Fv/Fm and non-photochemical quenching were identified for the studied species. PSII malfunctioning was largely associated with the observed photosynthetic down-regulation during heat wave treatments, however, its physiological recovery should be a key factor to determine species resilience to short-term extreme heat wave events.

Ambient temperature and added heat wave effects on hospitalizations in California from 1999 to 2009.

Science.gov (United States)

Sherbakov, Toki; Malig, Brian; Guirguis, Kristen; Gershunov, Alexander; Basu, Rupa

2018-01-01

Investigators have examined how heat waves or incremental changes in temperature affect health outcomes, but few have examined both simultaneously. We utilized distributed lag nonlinear models (DLNM) to explore temperature associations and evaluate possible added heat wave effects on hospitalizations in 16 climate zones throughout California from May through October 1999-2009. We define heat waves as a period when daily mean temperatures were above the zone- and month-specific 95th percentile for at least two consecutive days. DLNMs were used to estimate climate zone-specific non-linear temperature and heat wave effects, which were then combined using random effects meta-analysis to produce an overall estimate for each. With higher temperatures, admissions for acute renal failure, appendicitis, dehydration, ischemic stroke, mental health, non-infectious enteritis, and primary diabetes were significantly increased, with added effects from heat waves observed for acute renal failure and dehydration. Higher temperatures also predicted statistically significant decreases in hypertension admissions, respiratory admissions, and respiratory diseases with secondary diagnoses of diabetes, though heat waves independently predicted an added increase in risk for both respiratory types. Our findings provide evidence that both heat wave and temperature exposures can exert effects independently. Copyright © 2017 Elsevier Inc. All rights reserved.

Air pollution during the 2003 European heat wave as seen by MOZAIC airliners

Directory of Open Access Journals (Sweden)

M. Tressol

2008-04-01

Full Text Available This study presents an analysis of both MOZAIC profiles above Frankfurt and Lagrangian dispersion model simulations for the 2003 European heat wave. The comparison of MOZAIC measurements in summer 2003 with the 11-year MOZAIC climatology reflects strong temperature anomalies (exceeding 4°C throughout the lower troposphere. Higher positive anomalies of temperature and negative anomalies of both wind speed and relative humidity are found for the period defined here as the heat wave (2–14 August 2003, compared to the periods before (16–31 July 2003 and after (16–31 August 2003 the heat wave. In addition, Lagrangian model simulations in backward mode indicate the suppressed long-range transport in the mid- to lower troposphere and the enhanced southern origin of air masses for all tropospheric levels during the heat wave. Ozone and carbon monoxide also present strong anomalies (both ~+40 ppbv during the heat wave, with a maximum vertical extension reaching 6 km altitude around 11 August 2003. Pollution in the planetary boundary layer (PBL is enhanced during the day, with ozone mixing ratios two times higher than climatological values. This is due to a combination of factors, such as high temperature and radiation, stagnation of air masses and weak dry deposition, which favour the accumulation of ozone precursors and the build-up of ozone. A negligible role of a stratospheric-origin ozone tracer has been found for the lower troposphere in this study. From 29 July to 15 August 2003 forest fires burnt around 0.3×10⁶ ha in Portugal and added to atmospheric pollution in Europe. Layers with enhanced CO and NO_y mixing ratios, advected from Portugal, were crossed by the MOZAIC aircraft in the free troposphere over Frankfurt. A series of forward and backward Lagrangian model simulations have been performed to investigate the origin of anomalies during the whole heat wave. European anthropogenic emissions present the strongest

Thermal Conditions in the City of Poznań (Poland during Selected Heat Waves

Directory of Open Access Journals (Sweden)

Marek Półrolniczak

2018-01-01

Full Text Available The aim of the study was to characterise the occurrence of hot days and heat waves in Poznań in the 1966–2015 period, as well as to describe the thermal conditions in the city during selected heat waves between 2008 and 2015. The basis of the study was the daily maximum and minimum air temperature values for Poznań–Ławica station from 1966–2015 and the daily values of air temperature from eight measuring points located in the city in various land types from 2008 to 2015. A hot day was defined as a day with Tmax above the 95th annual percentile (from 1966 to 2015, while a heat wave was assumed to be at least five consecutive hot days. The research study conducted shows the increase of Tmax, number of hot days and frequency of heat waves in Poznań over the last 50 years. Across the area of the city (differentiation of urban area types according to Urban Atlas 2012, there was a great diversity of thermal conditions during the heat waves analysed.

Modifications of the urban heat island characteristics under exceptionally hot weather - A case study

Science.gov (United States)

Founda, Dimitra; Pierros, Fragiskos; Santamouris, Mathew

2016-04-01

Considerable recent research suggests that heat waves are becoming more frequent, more intense and longer in the future. Heat waves are characterised by the dominance of prolonged abnormally hot conditions related to synoptic scale anomalies, thus they affect extensive geographical areas. Heat waves (HW) have a profound impact on humans and they have been proven to increase mortality. Urban areas are known to be hotter than the surrounding rural areas due to the well documented urban heat island (UHI) phenomenon. Urban areas face increased risk under heat waves, due to the added heat from the urban heat island and increased population density. Given that urban populations keep increasing, citizens are exposed to significant heat related risk. Mitigation and adaptation strategies require a deep understanding of the response of the urban heat islands under extremely hot conditions. The response of the urban heat island under selected episodes of heat waves is examined in the city of Athens, from the comparison between stations of different characteristics (urban, suburban, coastal and rural). Two distinct episodes of heat waves occurring during summer 2000 were selected. Daily maximum air temperature at the urban station of the National Observatory of Athens (NOA) exceeded 40 0C for at least three consecutive days for both episodes. The intensity of UHI during heat waves was compared to the intensity under 'normal' conditions, represented from a period 'before' and 'after' the heat wave. Striking differences of UHI features between HW and no HW cases were observed, depending on the time of the day and the type of station. The comparison between the urban and the coastal station showed an increase of the order of 3 0C in the intensity of UHI during the HW days, as regards both daytime and nighttime conditions. The comparison between urban and a suburban (inland) station, revealed some different behaviour during HWs, with increases of the order of 3 0C in the nocturnal

Role of Soil Moisture vs. Recent Climate Change for the 2010 Heat Wave in Western Russia

Science.gov (United States)

Hauser, Mathias; Orth, René; Seneviratne, Sonia

2016-04-01

Extreme event attribution statements are often conditional on increased greenhouse gas concentrations or a particular ocean state, but not on other physical factors of the climate system. Here we extend the classical framework and assess the influence of soil moisture on a heat wave to obtain a physical attribution statement. In particular, we test the role of soil-moisture-temperature feedbacks which have been shown to be generally relevant for the build-up of exceptionally high temperatures. As a case study we investigate the severe 2010 heat wave in western Russia, which was previously found to be influenced by anthropogenic climate change. We quantify the relative role of climate change and that of soil moisture-temperature feedbacks with the event attribution framework and analyze ensemble simulations to distinguish the effect of climate change and the 2010 soil moisture conditions for annual maximum temperatures. We find that climate change from 1960 to 2000 alone has approximately tripled the risk of a severe heat wave in western Russia. The combined effect of climate change and the dry 2010 soil moisture yields a 13 times higher heat wave risk. We conclude that internal climate variability causing the dry 2010 soil moisture conditions formed the basis for this extreme heatwave.

Future risk assessment by estimating historical heat wave trends with projected heat accumulation using SimCLIM climate model in Pakistan

Science.gov (United States)

Nasim, Wajid; Amin, Asad; Fahad, Shah; Awais, Muhammad; Khan, Naeem; Mubeen, Muhammad; Wahid, Abdul; Turan, Veysel; Rehman, Muhammad Habibur; Ihsan, Muhammad Zahid; Ahmad, Shakeel; Hussain, Sajjad; Mian, Ishaq Ahmad; Khan, Bushra; Jamal, Yousaf

2018-06-01

Climate change has adverse effects at global, regional and local level. Heat wave events have serious contribution for global warming and natural hazards in Pakistan. Historical (1997-2015) heat wave were analyzed over different provinces (Punjab, Sindh and Baluchistan) of Pakistan to identify the maximum temperature trend. Heat accumulation in Pakistan were simulated by the General Circulation Model (GCM) combined with 3 GHG (Green House Gases) Representative Concentration Pathways (RCPs) (RCP-4.5, 6.0, and 8.5) by using SimCLIM model (statistical downscaling model for future trend projections). Heat accumulation was projected for year 2030, 2060, and 2090 for seasonal and annual analysis in Pakistan. Heat accumulation were projected to increase by the baseline year (1995) was represented in percentage change. Projection shows that Sindh and southern Punjab was mostly affected by heat accumulation. This study identified the rising trend of heat wave over the period (1997-2015) for Punjab, Sindh and Baluchistan (provinces of Pakistan), which identified that most of the meteorological stations in Punjab and Sindh are highly prone to heat waves. According to model projection; future trend of annual heat accumulation, in 2030 was increased 17%, 26%, and 32% but for 2060 the trends were reported by 54%, 49%, and 86% for 2090 showed highest upto 62%, 75%, and 140% for RCP-4.5, RCP-6.0, and RCP-8.5, respectively. While seasonal trends of heat accumulation were projected to maximum values for monsoon and followed by pre-monsoon and post monsoon. Heat accumulation in monsoon may affect the agricultural activities in the region under study.

Wave trajectory and electron cyclotron heating in tokamak plasmas

International Nuclear Information System (INIS)

Tanaka, S.; Maekawa, T.; Terumichi, Y.; Hamada, Y.

1980-01-01

Wave trajectories in high density tokamak plasmas are studied numerically. Results show that the ordinary wave injected at an appropriate incident angle can propagate into the dense plasmas and is mode-converted to the extraordinary wave at the plasma cutoff, is further converted to the electron Bernstein wave during passing a loop or a folded curve near the upper hybrid resonance layer, and is cyclotron damped away, resulting in local electron heating before arriving at the cyclotron resonance layer. Similar trajectory and damping are obtained when a microwave in a form of extraordinary wave is injected quasi-perpendicularly in the direction of decreasing toroidal field

HEATING AND ACCELERATION OF THE FAST SOLAR WIND BY ALFVÉN WAVE TURBULENCE

Energy Technology Data Exchange (ETDEWEB)

Van Ballegooijen, A. A.; Asgari-Targhi, M. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2016-04-20

We present numerical simulations of reduced magnetohydrodynamic (RMHD) turbulence in a magnetic flux tube at the center of a polar coronal hole. The model for the background atmosphere is a solution of the momentum equation and includes the effects of wave pressure on the solar wind outflow. Alfvén waves are launched at the coronal base and reflect at various heights owing to variations in Alfvén speed and outflow velocity. The turbulence is driven by nonlinear interactions between the counterpropagating Alfvén waves. Results are presented for two models of the background atmosphere. In the first model the plasma density and Alfvén speed vary smoothly with height, resulting in minimal wave reflections and low-energy dissipation rates. We find that the dissipation rate is insufficient to maintain the temperature of the background atmosphere. The standard phenomenological formula for the dissipation rate significantly overestimates the rate derived from our RMHD simulations, and a revised formula is proposed. In the second model we introduce additional density variations along the flux tube with a correlation length of 0.04 R {sub ⊙} and with relative amplitude of 10%. These density variations simulate the effects of compressive MHD waves on the Alfvén waves. We find that such variations significantly enhance the wave reflection and thereby the turbulent dissipation rates, producing enough heat to maintain the background atmosphere. We conclude that interactions between Alfvén and compressive waves may play an important role in the turbulent heating of the fast solar wind.

Ion Bernstein wave heating in a multi-component plasma

International Nuclear Information System (INIS)

Puri, S.

1980-10-01

Conditions for the coupling and absorption of Gross-Bernstein ion-cyclotron waves in a multi-component plasma are examined. Two cases are distinguished depending upon whether, the antenna initially launches, (i) the quasi-torsional slow electromagnetic wave with azimuthal magnetic field (TM) polarization, or (ii) the quasi-compressional fast wave with the electric field oriented azimuthally (TE). Analytic expressions for the plasma surface impedance are derived taking into account the pertinent warm plasma modifications near the vacuum-plasma interface. Antenna configurations capable of efficient coupling of the radio frequency energy to these modes are studied. A method for simulating waveguide like launching using transmission lines is pointed out. It is found that impurity concentrations exceeding a few parts in a thousand are capable of competing with the bulk ions in the energy absorption processes; this could lead to energy deposition near the plasma edge. Measures for avoiding edge heating problems by a careful choice of parameters e.g. restricting the heating frequency to the fundamental ion gyrofrequency are outlined. Equal care is to be exercised in limiting the nsub(z) spectrum to low discrete values in order to avoid the potentially dangerous problem of runaway electron heating. (orig.)

Predictability and Spatial Characteristics of New-York-City-Area Heat Waves

Science.gov (United States)

Raymond, C.; Horton, R. M.

2016-12-01

The origins, characteristics, and predictability of extreme heat waves in the Northeast U.S. are simultaneously examined at multiple scales, using hourly observational data from 1948-2014 and focusing in particular on the region surrounding New York City. A novel definition of heat waves - incorporating both temperature and moisture at hourly resolution - is used to identify 3-to-5-day heat waves whose dynamics are then analyzed from 3 weeks prior to 3 weeks subsequent to the event. Inter-event differences in dynamics such as the strength and position of geopotential-height anomalies; the strength, persistence, and orientation of sea breezes; and the dominant 850-hPa wind azimuth, all of which are filtered via local terrain and land-use to create differences in conditions between events at specific locations. In particular, using composite maps and back trajectories, they are found to play an important role in creating mesoscale differences in low-level moisture content, from one side of the metropolitan area to the other. Evidence is presented supporting the influence of coastline orientation in explaining the differences in the relationships between wind azimuth and temperature & moisture advection between New York City proper and northern New Jersey. Self-organizing maps are employed to classify heat waves based on the small-scale differences in temperature and moisture between events, and the results of this classification are then used in correlations with synoptic- and hemispheric-scale geopotential-height anomalies. Considerable predictability of event type on the small-scale (as well as occurrence of a heat wave of any kind) is found, originating primarily from central Pacific and western Atlantic SSTs.

Turbine related fish mortality

International Nuclear Information System (INIS)

Eicher, G.J.

1993-01-01

A literature review was conducted to assess the factors affecting turbine-related fish mortality. The mechanics of fish passage through a turbine is outlined, and various turbine related stresses are described, including pressure and shear effects, hydraulic head, turbine efficiency, and tailwater level. The methodologies used in determining the effects of fish passage are evaluated. The necessity of adequate controls in each test is noted. It is concluded that mortality is the result of several factors such as hardiness of study fish, fish size, concentrations of dissolved gases, and amounts of cavitation. Comparisons between Francis and Kaplan turbines indicate little difference in percent mortality. 27 refs., 5 figs

Electron heating and current drive by mode converted slow waves

International Nuclear Information System (INIS)

Majeski, R.; Phillips, C.K.; Wilson, J.R.

1994-01-01

An approach to obtaining efficient single pass mode conversion at high parallel wave number from the fast magnetosonic wave to the slow ion Bernstein wave, in a two-ion species tokamak plasma, is described. The intent is to produce localized electron heating or current drive via the mode converted slow wave. In particular, this technique can be adapted to off-axis current drive for current profile control. Modeling for the case of deuterium-tritium plasmas in TFTR is presented

The Effect of Microwave Heating on the Mortality of Ephestia kuehniella Zeller. and Oryzaephilus surinamensis L. and Determination of Energy Consumed for Raisin Product

Directory of Open Access Journals (Sweden)

Rahil Mirabimoghaddam

2017-03-01

covers both radio frequency and microwave has been investigated for insect control in foods. Microwaves radiation are a part of electromagnetic spectrum with wavelengths less than radio waves and more than infrared waves, which their frequency range are 300MHz to 30GHz. Materials and Methods: Two insect species, the lesser grain borer, O. surinamensis L. and mediterranean flour moth, E. kuehniella Zeller. Were reared under the laboratory condition at temperature of 27±2 C and relative humidity of 65%±5. The lesser grain borer was reared on the medium contains 99% wheat flour mixed along with 1% brewer’s yeast and the mediterranean flour moth were reared the medium contains on 90% wheat flour mixed along with 10% brewer’s yeast. In this study, the microwave oven (Media -MW-F-282ELKS was used which operates at 2450 MHz and variable power levels. The samples were exposed to microwave treatments at three power levels (450, 270 and 900W for four exposure times (20, 30, 40 and 50s. Each treatment (power and exposure time combination was replicated three times. Results and Discussion: The mortality of E. kuehniella at the highest level of microwave power (900W and for 20, 30, 40 and 50s exposure times were 51.67%, 71.63%, 91.53% and 100%, respectively. For the microwave power of 900W and exposure time of 20, 30, 40 and 50 s the mortality of O. surinamensis was 68.03%, 88.23%, 91.67% and 100%, %, respectively. The results showed, at a power level of 450W and an exposure time of 20s, the mortality of E. kuehniella and O. surinamensis were 20% and 33.33%, respectively. As the power increases to 720 and 900W, the mortality of E. kuehniella and O. surinamensis enhances to 33.33% and 56.63%, respectively. With increasing the exposure time, higher mortality was achieved at lower power levels. For the microwave power of 720W and exposure time of 40s, the mortality of E. kuehniella was 61.53%. When the exposure time was increased to 50s, the mortality of E. kuehniella was

Tokamak wave coupling and heating in the ICRF

International Nuclear Information System (INIS)

Romero, H.; Scharer, J.; Sund, R.

1983-01-01

The authors consider wave propagation in the vicinity of the Ion Cyclotron Range of Frequencies (ICRF) in general tokamak geometries. The problem of wave coupling by means of waveguides is addressed. In particular, the reflection coefficient for a simple TE 10 waveguide is obtained by taking into account both the z and y spectrum of the launcher. In order to take into account spatial gradients in the plasma medium, they use a one-dimensional slab model of the plasma. Good coupling and heating results are obtained for the first few harmonics for sufficiently weak edge density gradient and > about 1 keV core temperatures. To analyze the heating of the plasma interior in the presence of ICRF, a 2-D differential equation is being developed which takes into account spatial gradients and mode coupling

Monitoring and understanding changes in heat waves, cold waves, floods, and droughts in the United States: State of knowledge

Science.gov (United States)

Peterson, Thomas C.; Heim, Richard R.; Hirsch, Robert M.; Kaiser, Dale P.; Brooks, Harold; Diffenbaugh, Noah S.; Dole, Randall M.; Giovannettone, Jason P.; Guirguis, Kristen; Karl, Thomas R.; Katz, Richard W.; Kunkel, Kenneth E.; Lettenmaier, Dennis P.; McCabe, Gregory J.; Paciorek, Christopher J.; Ryberg, Karen R.; K Wolter, BS Silva; Schubert, Siegfried; Silva, Viviane B. S.; Stewart, Brooke C.; Vecchia, Aldo V.; Villarini, Gabriele; Vose, Russell S.; Walsh, John; Wehner, Michael; Wolock, David; Wolter, Klaus; Woodhouse, Connie A.; Wuebbles, Donald

2013-01-01

Weather and climate extremes have been varying and changing on many different time scales. In recent decades, heat waves have generally become more frequent across the United States, while cold waves have been decreasing. While this is in keeping with expectations in a warming climate, it turns out that decadal variations in the number of U.S. heat and cold waves do not correlate well with the observed U.S. warming during the last century. Annual peak flow data reveal that river flooding trends on the century scale do not show uniform changes across the country. While flood magnitudes in the Southwest have been decreasing, flood magnitudes in the Northeast and north-central United States have been increasing. Confounding the analysis of trends in river flooding is multiyear and even multidecadal variability likely caused by both large-scale atmospheric circulation changes and basin-scale “memory” in the form of soil moisture. Droughts also have long-term trends as well as multiyear and decadal variability. Instrumental data indicate that the Dust Bowl of the 1930s and the drought in the 1950s were the most significant twentieth-century droughts in the United States, while tree ring data indicate that the megadroughts over the twelfth century exceeded anything in the twentieth century in both spatial extent and duration. The state of knowledge of the factors that cause heat waves, cold waves, floods, and drought to change is fairly good with heat waves being the best understood.

Heat-Related Illnesses

Science.gov (United States)

... Share this! EmergencyCareForYou » Emergency 101 » Heat-Related Illnesses Heat-Related Illnesses Dr. Glenn Mitchell , Emergency physician at ... about heat cramps and heat stroke and exhaustion. Heat Cramps Symptoms include muscle spasms, usually in the ...

Traveling wave antenna for fast wave heating and current drive in tokamaks

International Nuclear Information System (INIS)

Ikezi, H.; Phelps, D.A.

1995-07-01

The traveling wave antenna for heating and current drive in the ion cyclotron range of frequencies is shown theoretically to have loading and wavenumber spectrum which are largely independent of plasma conditions. These characteristics have been demonstrated in low power experiments on the DIII-D tokamak, in which a standard four-strap antenna was converted to a traveling wave antenna through use of external coupling elements. The experiments indicate that the array maintains good impedance matching without dynamic tuning during abrupt changes in the plasma, such as during L- to H-mode transitions, edge localized mode activity, and disruptions. An analytic model was developed which exhibits the features observed in the experiments. Guidelines for the design of traveling wave antennas are derived from the validated model

[Strategies for protecting the elderly from the health-risks of heat-waves: measures undertaken in Italy in the summer of 2004].

Science.gov (United States)

de Martino, Annamaria; Vasselli, Stefania; D'Argenio, Paolo

2005-01-01

Heat waves constitute an important public health problem because of their potential serious health impact on vulnerable populations such as the elderly and individuals living in poor health, socioeconomic, cultural or environmental conditions. The summer of 2003 was the hottest summer, with respect to both minimum and maximum temperatures, of the last fifty years. During that summer, an increased mortality was found especially in the elderly population = 75 years. The Ministry of Health therefore released guidelines for the regions and other local authorities, regarding the measures be undertaken in order to safeguard the elderly and other vulnerable populations from the health risks associated with heat waves. Subsequently, a survey was performed to collect information regarding the projects put into practice in the summer of 2004 by the various regions and local authorities. The aim of the study was to promote a comparison and sharing of appropriately documented experiences. This article classifies and describes the various interventions that were put into practice.

Heat-Related Illnesses

Medline Plus

Full Text Available ... Share this! EmergencyCareForYou » Emergency 101 » Heat-Related Illnesses Heat-Related Illnesses Dr. Glenn Mitchell , Emergency physician at ... about heat cramps and heat stroke and exhaustion. Heat Cramps Symptoms include muscle spasms, usually in the ...

Escalating heat-stress mortality risk due to global warming in the Middle East and North Africa (MENA).

Science.gov (United States)

Ahmadalipour, Ali; Moradkhani, Hamid

2018-08-01

Climate change will substantially exacerbate extreme temperature and heatwaves. The impacts will be more intense across the Middle East and North Africa (MENA), a region mostly characterized by hot and arid climate, already intolerable for human beings in many parts. In this study, daily climate data from 17 fine-resolution Regional Climate Models (RCMs) are acquired to calculate wet-bulb temperature and investigate the mortality risk for people aged over 65 years caused by excessive heat stress across the MENA region. Spatially adaptive temperature thresholds are implemented for quantifying the mortality risk, and the analysis is conducted for the historical period of 1951-2005 and two future scenarios of RCP4.5 and RCP8.5 during the 2006-2100 period. Results show that the mortality risk will increase in distant future to 8-20 times higher than that of the historical period if no climate change mitigation is implemented. The coastal regions of the Red sea, Persian Gulf, and Mediterranean Sea indicate substantial increase in mortality risk. Nonetheless, the risk ratio will be limited to 3-7 times if global warming is limited to 2 °C. Climate change planning and adaptation is imperative for mitigating heat-related mortality risk across the region. Copyright © 2018 Elsevier Ltd. All rights reserved.

Test of a new heat-flow equation for dense-fluid shock waves.

Science.gov (United States)

Holian, Brad Lee; Mareschal, Michel; Ravelo, Ramon

2010-09-21

Using a recently proposed equation for the heat-flux vector that goes beyond Fourier's Law of heat conduction, we model shockwave propagation in the dense Lennard-Jones fluid. Disequilibrium among the three components of temperature, namely, the difference between the kinetic temperature in the direction of a planar shock wave and those in the transverse directions, particularly in the region near the shock front, gives rise to a new transport (equilibration) mechanism not seen in usual one-dimensional heat-flow situations. The modification of the heat-flow equation was tested earlier for the case of strong shock waves in the ideal gas, which had been studied in the past and compared to Navier-Stokes-Fourier solutions. Now, the Lennard-Jones fluid, whose equation of state and transport properties have been determined from independent calculations, allows us to study the case where potential, as well as kinetic contributions are important. The new heat-flow treatment improves the agreement with nonequilibrium molecular-dynamics simulations under strong shock wave conditions, compared to Navier-Stokes.

Effects of a Heat Wave on Nocturnal Stomatal Conductance in Eucalyptus camaldulensis

Directory of Open Access Journals (Sweden)

Víctor Resco de Dios

2018-06-01

Full Text Available Nocturnal transpiration constitutes a significant yet poorly understood component of the global water cycle. Modeling nocturnal transpiration has been complicated by recent findings showing that stomata respond differently to environmental drivers over day- vs. night-time periods. Here, we propose that nocturnal stomatal conductance depends on antecedent daytime conditions. We tested this hypothesis across six genotypes of Eucalyptus camaldulensis Dehnh. growing under different CO2 concentrations (ambient vs. elevated and exposed to contrasting temperatures (ambient vs. heat wave for four days prior to the night of measurements, when all plants experienced ambient temperature conditions. We observed significant effects after the heat wave that led to 36% reductions in nocturnal stomatal conductance. The response was partly driven by changes in daytime stomatal behavior but additional factors may have come into play. We also observed significant differences in response to the heat wave across genotypes, likely driven by local adaptation to their climate of origin, but CO2 played no effect. Stomatal models may need to incorporate the role of antecedent effects to improve projections particularly after drastic changes in the environment such as heat waves.

Alfven wave heating in ASDEX

International Nuclear Information System (INIS)

Besson, G.; Borg, G.G.; Lister, J.B.; Marmillod, Ph.; Braun, F.; Murphy, A.B.; Noterdaeme, J.M.; Ryter, F.; Wesner, F.

1990-01-01

An experiment has been completed on ASDEX to study the response of the plasma to Alfven wave heating (AWH). Antenna excitation was provided by the old TCA rf generator with an output power capability of 500 kW. Two poloidal loop antennas were installed at the east and west ends of the tokamak allowing either N=1 or N=2 phasings. Since the largest antenna coupling to the Alfven resonance is provided by the m=1 surface wave, the antenna consisted only of a single element on the low field side, whereas in TCA the antennas are located on the top and the bottom of the torus. The antenna elements consisted of 2 parallel bars of inductance 730 nH and, as in TCA, were left unshielded. A typical antenna circulating current of 2 kA peak at 1.80 MHz was provided for the experiments. (author) 3 refs., 4 figs

Relation between temperature and mortality in thirteen Spanish cities

OpenAIRE

Iñiguez, Carmen; Ballester, Ferran; Ferrándiz, Juan; Pérez Hoyos, Santiago; Sáez Zafra, Marc; López Estudillo, Antonio

2010-01-01

In this study we examined the shape of the association between temperature and mortality in 13 Spanish cities representing a wide range of climatic and socio-demographic conditions. The temperature value linked with minimum mortality (MMT) and the slopes before and after the turning point (MMT) were calculated. Most cities showed a V-shaped temperature-mortality relationship. MMTs were generally higher in cities with warmer climates. Cold and heat effects also depended on climate: effects wer...

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

Science.gov (United States)

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

2016-12-10

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

Resilience to seasonal heat wave episodes in a Mediterranean pine forest.

Science.gov (United States)

Tatarinov, Fedor; Rotenberg, Eyal; Maseyk, Kadmiel; Ogée, Jérôme; Klein, Tamir; Yakir, Dan

2016-04-01

Short-term, intense heat waves (hamsins) are common in the eastern Mediterranean region and provide an opportunity to study the resilience of forests to such events that are predicted to increase in frequency and intensity. The response of a 50-yr-old Aleppo pine (Pinus halepensis) forest to hamsin events lasting 1-7 d was studied using 10 yr of eddy covariance and sap flow measurements. The highest frequency of heat waves was c. four per month, coinciding with the peak productivity period (March-April). During these events, net ecosystem carbon exchange (NEE) and canopy conductance (gc ) decreased by c. 60%, but evapotranspiration (ET) showed little change. Fast recovery was also observed with fluxes reaching pre-stress values within a day following the event. NEE and gc showed a strong response to vapor pressure deficit that weakened as soil moisture decreased, while sap flow was primarily responding to changes in soil moisture. On an annual scale, heat waves reduced NEE and gross primary productivity by c. 15% and 4%, respectively. Forest resilience to short-term extreme events such as heat waves is probably a key to its survival and must be accounted for to better predict the increasing impact on productivity and survival of such events in future climates. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Ecological traps in shallow coastal waters-Potential effect of heat-waves in tropical and temperate organisms.

Directory of Open Access Journals (Sweden)

Catarina Vinagre

Full Text Available Mortality of fish has been reported in tide pools during warm days. That means that tide pools are potential ecological traps for coastal organisms, which happen when environmental changes cause maladaptive habitat selection. Heat-waves are predicted to increase in intensity, duration and frequency, making it relevant to investigate the role of tide pools as traps for coastal organisms. However, heat waves can also lead to acclimatization. If organisms undergo acclimatization prior to being trapped in tide pools, their survival chances may increase. Common tide pool species (46 species in total were collected at a tropical and a temperate area and their upper thermal limits estimated. They were maintained for 10 days at their mean summer sea surface temperature +3°C, mimicking a heat-wave. Their upper thermal limits were estimated again, after this acclimation period, to calculate each species' acclimation response. The upper thermal limits of the organisms were compared to the temperatures attained by tide pool waters to investigate if 1 tide pools could be considered ecological traps and 2 if the increase in upper thermal limits elicited by the acclimation period could make the organisms less vulnerable to this threat. Tropical tide pools were found to be ecological traps for an important number of common coastal species, given that they can attain temperatures higher than the upper thermal limits of most of those species. Tide pools are not ecological traps in temperate zones. Tropical species have higher thermal limits than temperate species, but lower acclimation response, that does not allow them to survive the maximum habitat temperature of tropical tide pools. This way, tropical coastal organisms seem to be, not only more vulnerable to climate warming per se, but also to an increase in the ecological trap effect of tide pools.

Changes in the Effect of Heat on Mortality in the Last 20 Years in Nine European Cities. Results from the PHASE Project.

Science.gov (United States)

de' Donato, Francesca K; Leone, Michela; Scortichini, Matteo; De Sario, Manuela; Katsouyanni, Klea; Lanki, Timo; Basagaña, Xavier; Ballester, Ferran; Åström, Christofer; Paldy, Anna; Pascal, Mathilde; Gasparrini, Antonio; Menne, Bettina; Michelozzi, Paola

2015-12-08

The European project PHASE aims to evaluate patterns of change in the temperature-mortality relationship and in the number of deaths attributable to heat in nine European cities in two periods, before and after summer 2003 (1996-2002 and 2004-2010). We performed age-specific Poisson regression models separately in the two periods, controlling for seasonality, air pollution and time trends. Distributed lag non-linear models were used to estimate the Relative Risks of daily mortality for increases in mean temperature from the 75th to 99th percentile of the summer distribution for each city. In the recent period, a reduction in the mortality risk associated to heat was observed only in Athens, Rome and Paris, especially among the elderly. Furthermore, in terms of heat-attributable mortality, 985, 787 and 623 fewer deaths were estimated, respectively, in the three cities. In Helsinki and Stockholm, there is a suggestion of increased heat effect. Noteworthy is that an effect of heat was still present in the recent years in all cities, ranging from +11% to +35%. In Europe, considering the warming observed in recent decades and population ageing, effective intervention measures should be promoted across countries, especially targeting vulnerable subgroups of the population with lower adaptive resources.

Associations between risk perception, spontaneous adaptation behavior to heat waves and heatstroke in Guangdong province, China.

Science.gov (United States)

Liu, Tao; Xu, Yan Jun; Zhang, Yong Hui; Yan, Qing Hua; Song, Xiu Ling; Xie, Hui Yan; Luo, Yuan; Rutherford, Shannon; Chu, Cordia; Lin, Hua Liang; Ma, Wen Jun

2013-10-02

In many parts of the world, including in China, extreme heat events or heat waves are likely to increase in intensity, frequency, and duration in light of climate change in the next decades. Risk perception and adaptation behaviors are two important components in reducing the health impacts of heat waves, but little is known about their relationships in China. This study aimed to examine the associations between risk perception to heat waves, adaptation behaviors, and heatstroke among the public in Guangdong province, China. A total of 2,183 adult participants were selected using a four-stage sampling method in Guangdong province. From September to November of 2010 each subject was interviewed at home by a well-trained investigator using a structured questionnaire. The information collected included socio-demographic characteristics, risk perception and spontaneous adaptation behaviors during heat wave periods, and heatstroke experience in the last year. Chi-square tests and unconditional logistic regression models were employed to analyze the data. This study found that 14.8%, 65.3% and 19.9% of participants perceived heat waves as a low, moderate or high health risk, respectively. About 99.1% participants employed at least one spontaneous adaptation behavior, and 26.2%, 51.2% and 22.6% respondents employed 7 adaptation behaviors during heat waves, respectively. Individuals with moderate (OR=2.93, 95% CI: 1.38-6.22) or high (OR=10.58, 95% CI: 4.74-23.63) risk perception experienced more heatstroke in the past year than others. Drinking more water and wearing light clothes in urban areas, while decreasing activity as well as wearing light clothes in rural areas were negatively associated with heatstroke. Individuals with high risk perception and employing risks of heatstroke (OR=47.46, 95% CI: 12.82-175.73). There is a large room for improving health risk perception and adaptation capacity to heat waves among the public of Guangdong province. People with higher

Associations between risk perception, spontaneous adaptation behavior to heat waves and heatstroke in Guangdong province, China

Science.gov (United States)

2013-01-01

Background In many parts of the world, including in China, extreme heat events or heat waves are likely to increase in intensity, frequency, and duration in light of climate change in the next decades. Risk perception and adaptation behaviors are two important components in reducing the health impacts of heat waves, but little is known about their relationships in China. This study aimed to examine the associations between risk perception to heat waves, adaptation behaviors, and heatstroke among the public in Guangdong province, China. Methods A total of 2,183 adult participants were selected using a four-stage sampling method in Guangdong province. From September to November of 2010 each subject was interviewed at home by a well-trained investigator using a structured questionnaire. The information collected included socio-demographic characteristics, risk perception and spontaneous adaptation behaviors during heat wave periods, and heatstroke experience in the last year. Chi-square tests and unconditional logistic regression models were employed to analyze the data. Results This study found that 14.8%, 65.3% and 19.9% of participants perceived heat waves as a low, moderate or high health risk, respectively. About 99.1% participants employed at least one spontaneous adaptation behavior, and 26.2%, 51.2% and 22.6% respondents employed 7 adaptation behaviors during heat waves, respectively. Individuals with moderate (OR=2.93, 95% CI: 1.38-6.22) or high (OR=10.58, 95% CI: 4.74-23.63) risk perception experienced more heatstroke in the past year than others. Drinking more water and wearing light clothes in urban areas, while decreasing activity as well as wearing light clothes in rural areas were negatively associated with heatstroke. Individuals with high risk perception and employing risks of heatstroke (OR=47.46, 95% CI: 12.82-175.73). Conclusions There is a large room for improving health risk perception and adaptation capacity to heat waves among the public of

Traveling-wave antenna for fast-wave heating and current drive in tokamaks

International Nuclear Information System (INIS)

Ikezi, H.; Phelps, D.A.

1997-01-01

The travelling-wave antenna for heating and current drive in the ion cyclotron range of frequencies is shown theoretically to have loading and wavenumber spectra that are largely independent of plasma conditions. These characteristics have been demonstrated in low-power experiments on the DIII-D tokamak, in which a standard four-strap antenna was converted to a traveling-wave antenna through use of external coupling elements. The experiments indicate that the array maintains good impedance matching without dynamic tuning during abrupt changes in the plasma, such as during L- to H-mode transitions, edge-localized mode activity, and disruptions. An analytic model was developed that exhibits the features observed in the experiments. Guidelines for the design of travelling-wave antennas are derived from the validated model. 11 refs., 14 figs

Introduction to wave heating and current drive in magnetized plasmas

International Nuclear Information System (INIS)

Pinsker, R. I.

2001-01-01

The development of high-power wave heating and current drive in magnetized plasmas in the last 40 years is a major ongoing success story in plasma science. A hallmark of this area of research has been the detailed quantitative comparison of theory and experiment; the good agreement consistently found is indicative of the robustness and the predictive power of the underlying theory. This tutorial paper is a brief overview of the fundamental concepts and applications of this branch of plasma science. Most of the high-power applications have been in three frequency regimes: the ion cyclotron range of frequencies (ICRF), the lower hybrid range of frequencies (LHRF), and the electron cyclotron range of frequencies (ECRF). The basic physics of wave propagation and damping in these regimes is briefly discussed. Some of the coupling structures (antennas) used to excite the waves at the plasma boundary are described, and the high-power systems used to generate the wave energy are touched on. Representative examples of the remarkably wide range of applications of high-power wave heating and current drive in high-temperature fusion plasmas will be discussed

Alfven wave heating and stability

International Nuclear Information System (INIS)

Villard, L.; Brunner, S.; Jaun, A.; Vaclavik, J.

1994-10-01

Alfven waves in fusion plasmas play an important role in a number of situations. First, in Alfven Wave Heating (AWH) schemes. Second, both theory and experiment have demonstrated the existence of Global Alfven Eigenmodes (GAEs). GAEs have been observed in different tokamaks (PRETEXT, TCA, TEXTOR, etc.) and, more recently, in a stellarator (Wendelstein 7-AS) where they were shown to become unstable under intense Neutral Beam injection. Third, the existence and possible destabilization by fast ions of Toroidicity induced Alfven Eigenmodes (TAEs) has been evidenced both theoretically and experimentally. This destabilization could hamper the operation of a magnetically confined fusion reactor by setting a limit on the number of fusion alpha particles in the plasma. It is therefore crucial to understand the mechanisms leading to the occurrence of the instability and also those that can stabilize the TAEs by increasing the strength of the damping. The aim is to be able to devise possible ways to avoid the instability of Alfven eigenmodes in a region of parameter space that is compatible with the functioning of a fusion reactor. A global perturbative approach is presented to tackle the problem of the linear stability of TAEs. Our model computes the overall wave particle power transfers to the different species and thus could also be applied to the study of alpha power extraction in the presence of Alfven waves. We indicate also how to go beyond the perturbative approach. (author) 15 figs., 38 refs

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

Science.gov (United States)

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.

Early emergence of anthropogenically forced heat waves in the western United States and Great Lakes

Science.gov (United States)

Lopez, Hosmay; West, Robert; Dong, Shenfu; Goni, Gustavo; Kirtman, Ben; Lee, Sang-Ki; Atlas, Robert

2018-05-01

Climate projections for the twenty-first century suggest an increase in the occurrence of heat waves. However, the time at which externally forced signals of anthropogenic climate change (ACC) emerge against background natural variability (time of emergence (ToE)) has been challenging to quantify, which makes future heat-wave projections uncertain. Here we combine observations and model simulations under present and future forcing to assess how internal variability and ACC modulate US heat waves. We show that ACC dominates heat-wave occurrence over the western United States and Great Lakes regions, with ToE that occurred as early as the 2020s and 2030s, respectively. In contrast, internal variability governs heat waves in the northern and southern Great Plains, where ToE occurs in the 2050s and 2070s; this later ToE is believed to be a result of a projected increase in circulation variability, namely the Great Plain low-level jet. Thus, greater mitigation and adaptation efforts are needed in the Great Lakes and western United States regions.

Numerical investigation of heat transfer effects in small wave rotor

International Nuclear Information System (INIS)

Deng, Shi; Okamoto, Koji; Teramoto, Susumu

2015-01-01

Although a wave rotor is expected to enhance the performance of the ultra-micro gas turbine, the device itself may be affected by downsizing. Apart from the immediate effect of viscosity on flow dynamics when downscaled, the effects of heat transfer on flow field increase at such small scales. To gain an insight into the effects of heat transfer on the internal flow dynamics, numerical investigations were carried out with adiabatic, isothermal and conjugate heat transfer boundary treatments at the wall, and the results compared and discussed in the present study. With the light shed by the discussion of adiabatic and conjugate heat transfer boundary treatments, this work presents investigations of the heat flux distributions, as well as the effects of heat transfer on the internal flow dynamics and the consequent charging and discharging processes for various sizes. When heat transfer is taken into account, states of fluid in the cell before compression process varies, shock waves in compression process are found to be weaker, and changes in the charging and discharging processes are observed. Heat transfer differences between conjugate heat transfer boundary treatment and isothermal boundary treatment are addressed through comparisons of local wall temperature and heat flux. As a result, the difference in discharging temperature of high pressure fluid is noticeable in all sizes investigated, and the rapid increase of differences between results of isothermal and conjugate heat transfer boundary treatment in small size reveals that for certain small sizes (length of cell < 23 mm) the thermal boundary treatment should be taken care of.

The effect of broad-band Alfven-cyclotron waves spectra on the preferential heating and differential acceleration of He{sup ++} ions in the solar wind

Energy Technology Data Exchange (ETDEWEB)

Maneva, Y. G. [Department of Physics, Catholic University of America, Washington DC, 20064 (United States) and Heliophysics Science Devision, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Ofman, L. [Department of Physics, Catholic University of America, Washington, DC 20064 (United States) and Heliophysics Science Devision, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Vinas, A. F. [Heliophysics Science Devision, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

2013-06-13

In anticipation of results from inner heliospheric missions such as the Solar Orbiter and the Solar Probe we present the results from 1.5D hybrid simulations to study the role of magnetic fluctuations for the heating and differential acceleration of He{sup ++} ions in the solar wind. We consider the effects of nonlinear Alfven-cyclotron waves at different frequency regimes. Monochromatic nonlinear Alfven-alpha-cyclotron waves are known to preferentially heat and accelerate He{sup ++} ions in collisionless low beta plasma. In this study we demonstrate that these effects are preserved when higherfrequency monochromatic and broad-band spectra of Alfven-proton-cyclotron waves are considered. Comparison between several nonlinear monochromatic waves shows that the ion temperatures, anisotropies and relative drift are quantitatively affected by the shift in frequency. Including a broad-band wave-spectrum results in a significant reduction of both the parallel and the perpendicular temperature components for the He{sup ++} ions, whereas the proton heating is barely influenced, with the parallel proton temperature only slightly enhanced. The differential streaming is strongly affected by the available wave power in the resonant daughter ion-acoustic waves. Therefore for the same initial wave energy, the relative drift is significantly reduced in the case of initial wave-spectra in comparison to the simulations with monochromatic waves.

A low-frequency wave motion mechanism enables efficient energy transport in carbon nanotubes at high heat fluxes.

Science.gov (United States)

Zhang, Xiaoliang; Hu, Ming; Poulikakos, Dimos

2012-07-11

The great majority of investigations of thermal transport in carbon nanotubes (CNTs) in the open literature focus on low heat fluxes, that is, in the regime of validity of the Fourier heat conduction law. In this paper, by performing nonequilibrium molecular dynamics simulations we investigated thermal transport in a single-walled CNT bridging two Si slabs under constant high heat flux. An anomalous wave-like kinetic energy profile was observed, and a previously unexplored, wave-dominated energy transport mechanism is identified for high heat fluxes in CNTs, originated from excited low frequency transverse acoustic waves. The transported energy, in terms of a one-dimensional low frequency mechanical wave, is quantified as a function of the total heat flux applied and is compared to the energy transported by traditional Fourier heat conduction. The results show that the low frequency wave actually overtakes traditional Fourier heat conduction and efficiently transports the energy at high heat flux. Our findings reveal an important new mechanism for high heat flux energy transport in low-dimensional nanostructures, such as one-dimensional (1-D) nanotubes and nanowires, which could be very relevant to high heat flux dissipation such as in micro/nanoelectronics applications.

Projection of temperature-related mortality due to cardiovascular disease in beijing under different climate change, population, and adaptation scenarios.

Science.gov (United States)

Zhang, Boya; Li, Guoxing; Ma, Yue; Pan, Xiaochuan

2018-04-01

Human health faces unprecedented challenges caused by climate change. Thus, studies of the effect of temperature change on total mortality have been conducted in numerous countries. However, few of those studies focused on temperature-related mortality due to cardiovascular disease (CVD) or considered future population changes and adaptation to climate change. We present herein a projection of temperature-related mortality due to CVD under different climate change, population, and adaptation scenarios in Beijing, a megacity in China. To this end, 19 global circulation models (GCMs), 3 representative concentration pathways (RCPs), 3 socioeconomic pathways, together with generalized linear models and distributed lag non-linear models, were used to project future temperature-related CVD mortality during periods centered around the years 2050 and 2070. The number of temperature-related CVD deaths in Beijing is projected to increase by 3.5-10.2% under different RCP scenarios compared with that during the baseline period. Using the same GCM, the future daily maximum temperatures projected using the RCP2.6, RCP4.5, and RCP8.5 scenarios showed a gradually increasing trend. When population change is considered, the annual rate of increase in temperature-related CVD deaths was up to fivefold greater than that under no-population-change scenarios. The decrease in the number of cold-related deaths did not compensate for the increase in that of heat-related deaths, leading to a general increase in the number of temperature-related deaths due to CVD in Beijing. In addition, adaptation to climate change may enhance rather than ameliorate the effect of climate change, as the increase in cold-related CVD mortality greater than the decrease in heat-related CVD mortality in the adaptation scenarios will result in an increase in the total number of temperature-related CVD mortalities. Copyright © 2018 Elsevier Inc. All rights reserved.

Heat Stroke

DEFF Research Database (Denmark)

Mørch, Sofie Søndergaard; Andersen, Johnny Dohn Holmgren; Bestle, Morten Heiberg

2017-01-01

not diagnosed until several days after admittance; hence treatment with cooling was delayed. Both patients were admitted to the intensive care unit, where they were treated with an external cooling device and received treatment for complications. Both cases ended fatally. As global warming continues, more heat......Heat stroke is an acute, life-threatening emergency characterized clinically by elevated body temperature and central nervous system dysfunction. Early recognition and treatment including aggressive cooling and management of life-threatening systemic complications are essential to reduce morbidity...... and mortality. This case report describes two Danish patients diagnosed with heat stroke syndrome during a heat wave in the summer of 2014. Both patients were morbidly obese and had several predisposing illnesses. However since heat stroke is a rare condition in areas with temperate climate, they were...

Electron heating and current drive by mode converted slow waves

International Nuclear Information System (INIS)

Majeski, R.; Phillips, C.K.; Wilson, J.R.

1994-08-01

An approach to obtaining efficient single pass mode conversion at high parallel wavenumber from the fast magnetosonic wave to the slow ion Bernstein wave, in a two ion species tokamak plasma, is described. The intent is to produce localized electron heating or current drive via the mode converted slow wave. In particular, this technique can be adapted to off-axis current drive for current profile control. Modelling for the case of deuterium-tritium plasmas in TFTR is presented

Projection of heat waves variation over a warming climate in China

Science.gov (United States)

Yue, X.; Wu, S.; Pan, T.

2016-12-01

Heat waves (HW) have adverse impacts on economies, human health, societies and environment, which have been observed around the world and are expected to increase in a warming climate. However, the variations of HW under climate change over China are not clear yet. Using the HadGEM2-ES RCP4.5 and RCP8.5 daily maximum temperature and humidity dataset, variation of heat waves in China for 2021-2050 comparing to 1991-2000 as baseline were analyzed. The CMA-HI (Heat Index standardized by China Meteorological Administration) index was used to calculate the frequency and intensity of head waves. This paper classified the HW into three intensity levels including mild HW, moderate HW and severe HW , and defined a heat wave event (HWE) as that CMA-HI are all above or equal to 2.8 and keep at a intensity level more than five consecutive days. Results show that during 2021to 2050, the distribution area, frequency and duration of each intensity level have an increasing trend over China, and those of severe HW will increase mostly. The distribution area of mild, moderate and severe HW will increase 18%, 22%, 35% respectively. Average HWE frequency of each level will concentrate on 0.5-1instead of 0-0.3 in baseline period. Maximum frequency of each intensity can reach to almost 3 times a year. During 1991-2000, the average frequency of mild HW, moderate HW and severe HW kept a downward sequence. But it will change to increase in the future, and the shift occurs during 2031-2040. In addition, only severe HW duration will increase in the future. Its average value will increase from 9days to 13days, and keep a maximum duration of 42days.While the average duration of mild HW and moderate HW just keep almost 6 days and 8 days as usual. Regionally, both the frequency and duration will keep high value in the region of eastern China, central China, southern China and central Xinjiang autonomous region in the future. And only severe HW has a great change in distribution. Under RCP 8

Assessing heat-related health risk in Europe via the Universal Thermal Climate Index (UTCI)

Science.gov (United States)

Di Napoli, Claudia; Pappenberger, Florian; Cloke, Hannah L.

2018-03-01

In this work, the potential of the Universal Thermal Climate Index (UTCI) as a heat-related health risk indicator in Europe is demonstrated. The UTCI is a bioclimate index that uses a multi-node human heat balance model to represent the heat stress induced by meteorological conditions to the human body. Using 38 years of meteorological reanalysis data, UTCI maps were computed to assess the thermal bioclimate of Europe for the summer season. Patterns of heat stress conditions and non-thermal stress regions are identified across Europe. An increase in heat stress up to 1 °C is observed during recent decades. Correlation with mortality data from 17 European countries revealed that the relationship between the UTCI and death counts depends on the bioclimate of the country, and death counts increase in conditions of moderate and strong stress, i.e., when UTCI is above 26 and 32 °C. The UTCI's ability to represent mortality patterns is demonstrated for the 2003 European heatwave. These findings confirm the importance of UTCI as a bioclimatic index that is able to both capture the thermal bioclimatic variability of Europe, and relate such variability with the effects it has on human health.

Exposure to a heat wave under food limitation makes an agricultural insecticide lethal: a mechanistic laboratory experiment

DEFF Research Database (Denmark)

Dinh, Khuong Van; Janssens, Lizanne; Stoks, Robby

2016-01-01

Extreme temperatures and exposure to agricultural pesticides are becoming more frequent and intense under global change. Their combination may be especially problematic when animals suffer food limitation. We exposed Coenagrion puella damselfly larvae to a simulated heat wave combined with food...... limitation and subsequently to a widespread agricultural pesticide (chlorpyrifos) in an indoor laboratory experiment designed to obtain mechanistic insights in the direct effects of these stressors in isolation and when combined. The heat wave reduced immune function (activity of phenoloxidase, PO...... variables. While the immediate effects of the heat wave were subtle, our results indicate the importance of delayed effects in shaping the total fitness impact of a heat wave when followed by pesticide exposure. Firstly, the combination of delayed negative effects of the heat wave and starvation...

The Heating of Solar Coronal Loops by Alfvén Wave Turbulence

Energy Technology Data Exchange (ETDEWEB)

Van Ballegooijen, A. A. [5001 Riverwood Avenue, Sarasota, FL 34231 (United States); Asgari-Targhi, M.; Voss, A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2017-11-01

In this paper we further develop a model for the heating of coronal loops by Alfvén wave turbulence (AWT). The Alfvén waves are assumed to be launched from a collection of kilogauss flux tubes in the photosphere at the two ends of the loop. Using a three-dimensional magnetohydrodynamic model for an active-region loop, we investigate how the waves from neighboring flux tubes interact in the chromosphere and corona. For a particular combination of model parameters we find that AWT can produce enough heat to maintain a peak temperature of about 2.5 MK, somewhat lower than the temperatures of 3–4 MK observed in the cores of active regions. The heating rates vary strongly in space and time, but the simulated heating events have durations less than 1 minute and are unlikely to reproduce the observed broad differential emission measure distributions of active regions. The simulated spectral line nonthermal widths are predicted to be about 27 km s{sup −1}, which is high compared to the observed values. Therefore, the present AWT model does not satisfy the observational constraints. An alternative “magnetic braiding” model is considered in which the coronal field lines are subject to slow random footpoint motions, but we find that such long-period motions produce much less heating than the shorter-period waves launched within the flux tubes. We discuss several possibilities for resolving the problem of producing sufficiently hot loops in active regions.

Existence of a time-dependent heat flux-related ponderomotive effect

International Nuclear Information System (INIS)

Schamel, H.; Sack, C.

1980-01-01

The existence of a new ponderomotive effect associated with high-frequency waves is pointed out. It originates when time-dependency, mean velocities, or divergent heat fluxes are involved and it supplements the two effects known previously, namely, the ponderomotive force and fake heating. Two proofs are presented; the first is obtained by establishing the momentum equations generalized by including radiation effects and the second by solving the quasi-linear-type diffusion equation explicitly. For a time-dependent wave packet the solution exhibits a new contribution in terms of an integral over previous states. Owing to this term, the plasma has a memory which leads to a breaking of the time symmetry of the plasma response. The range, influenced by the localized wave packet, expands during the course of time due to streamers emanating from the wave active region. Perturbations, among which is the heat flux, are carried to remote positions and, consequently, the region accessible to wave heating is increased. The density dip appears to be less pronounced at the center, and its generation and decay are delayed. The analysis includes a self-consistent action of high-frequency waves as well as the case of traveling wave packets. In order to establish the existence of this new effect, the analytical results are compared with recent microwave experiments. The possibility of generating fast particles by this new ponderomotive effect is emphasized

Pediatric heat-related illness: recommendations for prevention and management [digest].

Science.gov (United States)

Dunn, Roberta J; Kim, Tommy Y; Chaudhari, Pradip

2017-08-22

Infants, children, and adolescents are at increased risk for heat-related illness due to their inability to remove themselves from dangerous environments. Evidence shows that morbidity and mortality from heat illness is related to the length of time core temperature is elevated, so rapid reduction and accurate serial measurements are crucial to prevention of organ system damage and death. The primary methods of patient cooling are conduction (ice-water immersion, cold packs) and convection (moisture and moving air). The choice of method used may depend on availability of equipment, but there is evidence that can guide optimal use of resources. This issue presents evidence-based recommendations and best practices in heat-illness resuscitation, including managing children who are obese, have special needs or take medications, and advocacy for prevention strategies. [Points & Pearls is a digest of Pediatric Emergency Medicine Practice].

Drought and Heat Waves: The Role of SST and Land Surface Feedbacks

Science.gov (United States)

Schubert, Siegfried

2011-01-01

Drought occurs on a wide range of time scales, and within a variety of different types of regional climates. At the shortest time scales it is often associated with heat waves that last only several weeks to a few months but nevertheless can have profound detrimental impacts on society (e.g., heat-related impacts on human health, desiccation of croplands, increased fire hazard), while at the longest time scales it can extend over decades and can lead to long term structural changes in many aspects of society (e.g., agriculture, water resources, wetlands, tourism, population shifts). There is now considerable evidence that sea surface temperatures (SSTs) play a leading role in the development of drought world-wide, especially at seasonal and longer time scales, though land-atmosphere feedbacks can also play an important role. At shorter (subseasonal) time scales, SSTs are less important, but land feedbacks can play a critical role in maintaining and amplifying the atmospheric conditions associated with heat waves and short-term droughts. This talk reviews our current understanding of the physical mechanisms that drive precipitation and temperature variations on subseasonal to centennial time scales. This includes an assessment of predictability, prediction skill, and user needs at all time scales.

Investigation of the radiation properties of magnetospheric ELF waves induced by modulated ionospheric heating

Science.gov (United States)

Wang, Feng; Ni, Binbin; Zhao, Zhengyu; Zhao, Shufan; Zhao, Guangxin; Wang, Min

2017-05-01

Electromagnetic extremely low frequency (ELF) waves play an important role in modulating the Earth's radiation belt electron dynamics. High-frequency (HF) modulated heating of the ionosphere acts as a viable means to generate artificial ELF waves. The artificial ELF waves can reside in two different plasma regions in geo-space by propagating in the ionosphere and penetrating into the magnetosphere. As a consequence, the entire trajectory of ELF wave propagation should be considered to carefully analyze the wave radiation properties resulting from modulated ionospheric heating. We adopt a model of full wave solution to evaluate the Poynting vector of the ELF radiation field in the ionosphere, which can reflect the propagation characteristics of the radiated ELF waves along the background magnetic field and provide the initial condition of waves for ray tracing in the magnetosphere. The results indicate that the induced ELF wave energy forms a collimated beam and the center of the ELF radiation shifts obviously with respect to the ambient magnetic field with the radiation power inversely proportional to the wave frequency. The intensity of ELF wave radiation also shows a weak correlation with the size of the radiation source or its geographical location. Furthermore, the combination of ELF propagation in the ionosphere and magnetosphere is proposed on basis of the characteristics of the ELF radiation field from the upper ionospheric boundary and ray tracing simulations are implemented to reasonably calculate magnetospheric ray paths of ELF waves induced by modulated ionospheric heating.

A Simulated Heat Wave Has Diverse Effects on Immune Function and Oxidative Physiology in the Corn Snake (Pantherophis guttatus).

Science.gov (United States)

Stahlschmidt, Z R; French, S S; Ahn, A; Webb, A; Butler, M W

Animals will continue to encounter increasingly warm environments, including more frequent and intense heat waves. Yet the physiological consequences of heat waves remain equivocal, potentially because of variation in adaptive plasticity (reversible acclimation) and/or aspects of experimental design. Thus, we measured a suite of physiological variables in the corn snake (Pantherophis guttatus) after exposure to field-parameterized, fluctuating temperature regimes (moderate temperature and heat wave treatments) to address two hypotheses: (1) a heat wave causes physiological stress, and (2) thermal performance of immune function exhibits adaptive plasticity in response to a heat wave. We found little support for our first hypothesis because a simulated heat wave had a negative effect on body mass, but it also reduced oxidative damage and did not affect peak performance of three immune metrics. Likewise, we found only partial support for our second hypothesis. After exposure to a simulated heat wave, P. guttatus exhibited greater performance breadth and reduced temperature specialization (the standardized difference between peak performance and performance breadth) for only one of three immune metrics and did so in a sex-dependent manner. Further, a simulated heat wave did not elicit greater performance of any immune metric at higher temperatures. Yet a heat wave likely reduced innate immune function in P. guttatus because each metric of innate immune performance in this species (as in most vertebrates) was lower at elevated temperatures. Together with previous research, our study indicates that a heat wave may have complex, modest, and even positive physiological effects in some taxa.

Propagation of a surface electromagnetic wave in a plasma with allowance for electron heating

International Nuclear Information System (INIS)

Boev, A.G.; Prokopov, A.V.

1978-01-01

Considered is propagation of a surface high-frequency wave in a semibounded plasma, which electron component is heated within the wave field. Dissipative effects are considered small, that is possible if wave frequency is much higher than the collision frequency and phase velocity of wave considerably exceeds electron heat velocity. Under conditions of anomalous skin-effect the distributions of electron temperature and wave damping have been found. It is established, that higher electron temperature on the boundary results in a higher decrease of temperature inside a plasma, far from the boundary temperature decreases exponentially; damping coefficient under anomalous skin-effect conditions is characterized by a stronger dependence not only on the wave amplitude, but as well as on gas pressure and wave frequency in comparison with normal conditions

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

Directory of Open Access Journals (Sweden)

Yan Cui

2016-12-01

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

Heat wave propagation in a thin film irradiated by ultra-short laser pulses

International Nuclear Information System (INIS)

Yoo, Jae Gwon; Kim, Cheol Jung; Lim, C. H.

2004-01-01

A thermal wave solution of a hyperbolic heat conduction equation in a thin film is developed on the basis of the Green's function formalism. Numerical computations are carried out to investigate the temperature response and the propagation of the thermal wave inside a thin film due to a heat pulse generated by ultra-short laser pulses with various laser pulse durations and thickness of the film

ON THE SPATIAL SCALES OF WAVE HEATING IN THE SOLAR CHROMOSPHERE

International Nuclear Information System (INIS)

Soler, Roberto; Ballester, Jose Luis; Carbonell, Marc

2015-01-01

Dissipation of magnetohydrodynamic (MHD) wave energy has been proposed as a viable heating mechanism in the solar chromospheric plasma. Here, we use a simplified one-dimensional model of the chromosphere to theoretically investigate the physical processes and spatial scales that are required for the efficient dissipation of Alfvén waves and slow magnetoacoustic waves. We consider the governing equations for a partially ionized hydrogen-helium plasma in the single-fluid MHD approximation and include realistic wave damping mechanisms that may operate in the chromosphere, namely, Ohmic and ambipolar magnetic diffusion, viscosity, thermal conduction, and radiative losses. We perform an analytic local study in the limit of small amplitudes to approximately derive the lengthscales for critical damping and efficient dissipation of MHD wave energy. We find that the critical dissipation lengthscale for Alfvén waves depends strongly on the magnetic field strength and ranges from 10 m to 1 km for realistic field strengths. The damping of Alfvén waves is dominated by Ohmic diffusion for weak magnetic field and low heights in the chromosphere, and by ambipolar diffusion for strong magnetic field and medium/large heights in the chromosphere. Conversely, the damping of slow magnetoacoustic waves is less efficient, and spatial scales shorter than 10 m are required for critical damping. Thermal conduction and viscosity govern the damping of slow magnetoacoustic waves and play an equally important role at all heights. These results indicate that the spatial scales at which strong wave heating may work in the chromosphere are currently unresolved by observations

ON THE SPATIAL SCALES OF WAVE HEATING IN THE SOLAR CHROMOSPHERE

Energy Technology Data Exchange (ETDEWEB)

Soler, Roberto; Ballester, Jose Luis [Departament de Física, Universitat de les Illes Balears, E-07122, Palma de Mallorca (Spain); Carbonell, Marc, E-mail: roberto.soler@uib.es [Institute of Applied Computing and Community Code (IAC), Universitat de les Illes Balears, E-07122, Palma de Mallorca (Spain)

2015-09-10

Dissipation of magnetohydrodynamic (MHD) wave energy has been proposed as a viable heating mechanism in the solar chromospheric plasma. Here, we use a simplified one-dimensional model of the chromosphere to theoretically investigate the physical processes and spatial scales that are required for the efficient dissipation of Alfvén waves and slow magnetoacoustic waves. We consider the governing equations for a partially ionized hydrogen-helium plasma in the single-fluid MHD approximation and include realistic wave damping mechanisms that may operate in the chromosphere, namely, Ohmic and ambipolar magnetic diffusion, viscosity, thermal conduction, and radiative losses. We perform an analytic local study in the limit of small amplitudes to approximately derive the lengthscales for critical damping and efficient dissipation of MHD wave energy. We find that the critical dissipation lengthscale for Alfvén waves depends strongly on the magnetic field strength and ranges from 10 m to 1 km for realistic field strengths. The damping of Alfvén waves is dominated by Ohmic diffusion for weak magnetic field and low heights in the chromosphere, and by ambipolar diffusion for strong magnetic field and medium/large heights in the chromosphere. Conversely, the damping of slow magnetoacoustic waves is less efficient, and spatial scales shorter than 10 m are required for critical damping. Thermal conduction and viscosity govern the damping of slow magnetoacoustic waves and play an equally important role at all heights. These results indicate that the spatial scales at which strong wave heating may work in the chromosphere are currently unresolved by observations.

Simulation of Heating with the Waves of Ion Cyclotron Range of Frequencies in Experimental Advanced Superconducting Tokamak

International Nuclear Information System (INIS)

Yang Cheng; Zhu Sizheng; Zhang Xinjun

2010-01-01

Simulation on the heating scenarios in experimental advanced superconducting tokamak (EAST) was performed by using a full wave code TORIC. The locations of resonance layers for these heating schemes are predicted and the simulations for different schemes in ICRF experiments in EAST, for example, ion heating (both fundamental and harmonic frequency) or electron heating (by direct fast waves or by mode conversion waves), on-axis or off-axis heating, and high-field-side (HFS) launching or low-field-side (LFS) launching, etc, were conducted. For the on-axis minority ion heating of 3 He in D( 3 He) plasma, the impacts of both density and temperature on heating were discussed in the EAST parameter ranges.

The Ion Cyclotron, Lower Hybrid, and Alfven Wave Heating Methods

International Nuclear Information System (INIS)

Koch, R.

2004-01-01

This lecture covers the practical features and experimental results of the three heating methods. The emphasis is on ion cyclotron heating. First, we briefly come back to the main non-collisional heating mechanisms and to the particular features of the quasilinear coefficient in the ion cyclotron range of frequencies (ICRF). The specific case of the ion-ion hybrid resonance is treated, as well as the polarisation issue and minority heating scheme. The various ICRF scenarios are reviewed. The experimental applications of ion cyclotron resonance heating (ICRH) systems are outlined. Then, the lower hybrid and Alfven wave heating and current drive experimental results are covered more briefly. Where applicable, the prospects for ITER are commented

Could aerosol emissions be used for regional heat wave mitigation?

Directory of Open Access Journals (Sweden)

D. N. Bernstein

2013-07-01

Full Text Available Geoengineering applications by injection of sulfate aerosols into the stratosphere are under consideration as a measure of last resort to counter global warming. Here a potential regional-scale application to offset the impacts of heat waves is critically examined. Using the Weather Research and Forecasting model with fully coupled chemistry (WRF-Chem, the effect of regional-scale sulfate aerosol emission over California in each of two days of the July 2006 heat wave is used to quantify potential reductions in surface temperature as a function of emission rates in a layer at 12 km altitude. Local meteorological factors yield geographical differences in surface air temperature sensitivity. For emission rates of approximately 30 μg m−2 s−1 of sulfate aerosols (with standard WRF-Chem size distribution over the region, temperature decreases of around 7 °C result during the middle part of the day over the Central Valley, one of the areas hardest hit by the heat wave. Regions more ventilated with oceanic air such as Los Angeles have slightly smaller reductions. The length of the hottest part of the day is also reduced. Advection effects on the aerosol cloud must be more carefully forecast for smaller injection regions. Verification of the impacts could be done via measurements of differences in reflected and surface downward shortwave. Such regional geoengineering applications with specific near-term target effects but smaller cost and side effects could potentially provide a means of testing larger scale applications. However, design considerations for regional applications, such as a preference for injection at a level of relatively low wind speed, differ from those for global applications. The size of the required injections and the necessity of injection close to the target region raise substantial concerns. The evaluation of this regional-scale application is thus consistent with global model evaluations, emphasizing that mitigation via

Contrasting responses of urban and rural surface energy budgets to heat waves explain synergies between urban heat islands and heat waves

International Nuclear Information System (INIS)

Li, Dan; Sun, Ting; Liu, Maofeng; Yang, Long; Wang, Linlin; Gao, Zhiqiu

2015-01-01

Heat waves (HWs) are projected to become more frequent and last longer over most land areas in the late 21st century, which raises serious public health concerns. Urban residents face higher health risks due to synergies between HWs and urban heat islands (UHIs) (i.e., UHIs are higher under HW conditions). However, the responses of urban and rural surface energy budgets to HWs are still largely unknown. This study analyzes observations from two flux towers in Beijing, China and reveals significant differences between the responses of urban and rural (cropland) ecosystems to HWs. It is found that UHIs increase significantly during HWs, especially during the nighttime, implying synergies between HWs and UHIs. Results indicate that the urban site receives more incoming shortwave radiation and longwave radiation due to HWs as compared to the rural site, resulting in a larger radiative energy input into the urban surface energy budget. Changes in turbulent heat fluxes also diverge strongly for the urban site and the rural site: latent heat fluxes increase more significantly at the rural site due to abundant available water, while sensible heat fluxes and possibly heat storage increase more at the urban site. These comparisons suggest that the contrasting responses of urban and rural surface energy budgets to HWs are responsible for the synergies between HWs and UHIs. As a result, urban mitigation and adaption strategies such as the use of green roofs and white roofs are needed in order to mitigate the impact of these synergies. (letter)

Impacts of updated green vegetation fraction data on WRF simulations of the 2006 European heat wave

Science.gov (United States)

Refslund, J.; Dellwik, E.; Hahmann, A. N.; Barlage, M. J.; Boegh, E.

2012-12-01

Climate change studies suggest an increase in heat wave occurrences over Europe in the coming decades. Extreme events with excessive heat and associated drought will impact vegetation growth and health and lead to alterations in the partitioning of the surface energy. In this study, the atmospheric conditions during the heat wave year 2006 over Europe were simulated using the Weather Research and Forecasting (WRF) model. To account for the drought effects on the vegetation, new high-resolution green vegetation fraction (GVF) data were developed for the domain using NDVI data from MODIS satellite observations. Many empirical relationships exist to convert NDVI to GVF and both a linear and a quadratic formulation were evaluated. The new GVF product has a spatial resolution of 1 km2 and a temporal resolution of 8 days. To minimize impacts from low-quality satellite retrievals in the NDVI series, as well as for comparison with the default GVF climatology in WRF, a new background climatology using 10 recent years of observations was also developed. The annual time series of the new GVF climatology was compared to the default WRF GVF climatology at 18 km2 grid resolution for the most common land use classes in the European domain. The new climatology generally has higher GVF levels throughout the year, in particular an extended autumnal growth season. Comparison of 2006 GVF with the climatology clearly indicates vegetation stresses related to heat and drought. The GVF product based on a quadratic NDVI relationship shows the best agreement with the magnitude and annual range of the default input data, in addition to including updated seasonality for various land use classes. The new GVF products were tested in WRF and found to work well for the spring of 2006 where the difference between the default and new GVF products was small. The WRF 2006 heat wave simulations were verified by comparison with daily gridded observations of mean, minimum and maximum temperature and

Spatiotemporal characteristics of heat waves over China in regional climate simulations within the CORDEX-EA project