Extreme Heat Days Research Articles

Does Extreme Weather Drive Interregional Brain Drain in the U.S.? Evidence from a Sorting Model

Previous studies have identified mean temperature as an important factor in household location choice, but no study has measured the impact of extreme weather on U.S. interregional brain drain. We estimate a residential sorting model to examine the effects of extreme weather on heterogeneous household location choices across the United States. We find that college graduates are more sensitive to extreme temperatures and are willing to pay more than other demographic groups to avoid hot weather. In light of predicted increases in extreme heat days in the West and Southwest, these areas may be at risk of significant human capital loss.

Micrometeorological simulations to predict the impacts of heat mitigation strategies on pedestrian thermal comfort in a Los Angeles neighborhood

The urban heat island impacts the thermal comfort of pedestrians in cities. In this paper, the effects of four heat mitigation strategies on micrometeorology and the thermal comfort of pedestrians were simulated for a neighborhood in eastern Los Angeles County. The strategies investigated include solar reflective ‘cool roofs’, vegetative ‘green roofs’, solar reflective ‘cool pavements’, and increased street-level trees. A series of micrometeorological simulations for an extreme heat day were carried out assuming widespread adoption of each mitigation strategy. Comparing each simulation to the control simulation assuming current land cover for the neighborhood showed that additional street-trees and cool pavements reduced 1.5 m air temperature, while cool and green roofs mostly provided cooling at heights above pedestrian level. However, cool pavements increased reflected sunlight from the ground to pedestrians at a set of unshaded receptor locations. This reflected radiation intensified the mean radiant temperature and consequently increased physiological equivalent temperature (PET) by 2.2 °C during the day, reducing the thermal comfort of pedestrians. At another set of receptor locations that were on average 5 m from roadways and underneath preexisting tree cover, cool pavements caused significant reductions in surface air temperatures and small changes in mean radiant temperature during the day, leading to decreases in PET of 1.1 °C, and consequent improvements in thermal comfort. For improving thermal comfort of pedestrians during the afternoon in unshaded locations, adding street trees was found to be the most effective strategy. However, afternoon thermal comfort improvements in already shaded locations adjacent to streets were most significant for cool pavements. Green and cool roofs showed the lowest impact on the thermal comfort of pedestrians since they modify the energy balance at roof level, above the height of pedestrians.

Mortality risks during extreme temperature events (ETEs) using a distributed lag non-linear model.

This study investigates the relationship between all-cause mortality and extreme temperature events (ETEs) from 1975 to 2004. For 50 U.S. locations, these heat and cold events were defined based on location-specific thresholds of daily mean apparent temperature. Heat days were defined by a 3-day mean apparent temperature greater than the 95th percentile while extreme heat days were greater than the 97.5th percentile. Similarly, calculations for cold and extreme cold days relied upon the 5th and 2.5th percentiles. A distributed lag non-linear model assessed the relationship between mortality and ETEs for a cumulative 14-day period following exposure. Subsets for season and duration effect denote the differences between early- and late-season as well as short and long ETEs. While longer-lasting heat days resulted in elevated mortality, early season events also impacted mortality outcomes. Over the course of the summer season, heat-related risk decreased, though prolonged heat days still had a greater influence on mortality. Unlike heat, cold-related risk was greatest in more southerly locations. Risk was highest for early season cold events and decreased over the course of the winter season. Statistically, short episodes of cold showed the highest relative risk, suggesting unsettled weather conditions may have some relationship to cold-related mortality. For both heat and cold, results indicate higher risk to the more extreme thresholds. Risk values provide further insight into the role of adaptation, geographical variability, and acclimatization with respect to ETEs.

대구와 제주의 폭염 및 열대야의 발생 특성

Observation data (1981-2014) and climate change scenario data (historical: 1981-2005; RCP 2.6 and 8.5: 2006-2100) were used to analyze occurrence and future outlook of the extreme heat days and tropical nights in Daegu and Jeju. Then we compared the mortality and observations data (1993-2013). Durin...

Urban climate change-related effects on extreme heat events in Rostock, Germany

The urban heat island effect poses a challenge in several cities, and may affect human and ecosystem health. It was proven that relatively small urban conglomerations in mid-latitudes, such as the case study region of Rostock, have undergone a considerable effect recently, noticeable particularly in the warm season. Due to climatic changes, these effects are expected to alter in intensity and/or frequency. This was investigated using a model that focuses on interactions between land use and surface temperatures and on specific air conditions in cities. The model enables urban surface temperature differences to be projected with regard to different assumptions of (future or planned) land use/land cover and its specific characteristics. In addition, 99th percentile summer days from the period 1961–1990 and scenario runs from regional climate models (RCMs) were used as an example of extreme heat events. The frequency of occurrence of extreme heat events resembling those occurring in the present day will be up to four (2041–2070) and six (2071–2100) times higher, respectively. Furthermore, the average temperature on defined extreme heat days will rise by 1.6 to 3.4 °C (2041–2070) and 2.2 to 4.4 °C (2071–2100), respectively. The model calculated no significant effects for differences in maximum surface temperatures between land use classes. Some parts of land use change scenarios constructed during scenario workshops in Rostock were integrated into the surface temperature model with regard to climate change adaptation. The results revealed a range of outcomes, from an enlargement of vulnerable areas to the near eradication of climate change-related heat effects in several areas.

Comparisons of the Circulation Anomalies Associated with Extreme Heat in Different Regions of Eastern China

Abstract The circulation associated with extreme heat (EH) typically shows an anomalous anticyclone that enhances temperature through adiabatic heating, but this study indicates obvious spatial variation in eastern China. The EH-related circulation pattern in eastern China can be classified into three categories: typical extratropical pattern, monsoonal pattern, and foehn pattern. EH over northeastern China and eastern north China is characterized by a typical pattern involving an anomalous anticyclone and subsidence, and the air temperature increases throughout almost the entire troposphere. In contrast, EH over the Yangtze River valley and south China is associated with the monsoonal pattern. Over these regions, the air temperature only increases in the lower troposphere as a result of anomalous subsidence and lower humidity that has resulted from a farther north transportation of water vapor by a stronger monsoonal southwesterly. Meanwhile, the air temperature decreases in the upper troposphere because of the decrease of latent heat caused by suppressed precipitation. On the other hand, western north China, with most of its stations located on the eastern leeside of mountains, is obviously influenced by the foehn effect on EH days. The foehn-related northwesterly anomalies bring drier and warmer air from the mountains to sink on the leeside and greatly increase the air temperature in the lower troposphere, particularly near the surface. Therefore, the impacts of monsoon and topography should be taken into consideration when EH-related circulations are discussed over the many regions of eastern China. As a result, the reliable projection of air temperature in these regions under global warming is a challenging problem.

Geographic dimensions of heat-related mortality in seven U.S. cities

Spatially targeted interventions may help protect the public when extreme heat occurs. Health outcome data are increasingly being used to map intra-urban variability in heat-health risks, but there has been little effort to compare patterns and risk factors between cities. We sought to identify places within large metropolitan areas where the mortality rate is highest on hot summer days and determine if characteristics of high-risk areas are consistent from one city to another. A Poisson regression model was adapted to quantify temperature–mortality relationships at the postal code scale based on 2.1 million records of daily all-cause mortality counts from seven U.S. cities. Multivariate spatial regression models were then used to determine the demographic and environmental variables most closely associated with intra-city variability in risk.Significant mortality increases on extreme heat days were confined to 12–44% of postal codes comprising each city. Places with greater risk had more developed land, young, elderly, and minority residents, and lower income and educational attainment, but the key explanatory variables varied from one city to another. Regression models accounted for 14–34% of the spatial variability in heat-related mortality. The results emphasize the need for public health plans for heat to be locally tailored and not assume that pre-identified vulnerability indicators are universally applicable. As known risk factors accounted for no more than one third of the spatial variability in heat–health outcomes, consideration of health outcome data is important in efforts to identify and protect residents of the places where the heat-related health risks are the highest.

Apis sets record red clover seed: a climatic aberration

Western Oregon, USA is one of the better red clover seed-producing areas in the world, having an average yield of 676 kg/ha; individual growers report yields of over 1000 kg/ha. Bloom normally lasts from late June through to the third week in August in well-managed fields. From late June through the third week of July, Apis mellifera is the predominant pollinator. By early August, Apis is usually displaced by very large populations of workers and males of several species of Bombus, especially B. vosnesenskii Radoszkowski. However, 2009 was unique in that the last 16 days in July the max–mean temperature was 35.4 °C, with a max of 41.0 °C. Apis responded by changing its pollen collection in red clover from ±1% in previous years, to 41.5% during the 16 days of extreme heat, resulting in a yield of 1045 kg/ha in the first 30 days of red clover bloom. It is postulated that the extreme heat in that year reduced the turgidity of the clover floret and that the accompanying low humidity increased the sugar content of the nectar, making the floret more accessible and attractive. Reference is made to the parallels between high temperatures and Apis pollination of alfalfa in California, and our observations on red clover in Oregon.

Climate change: challenges and opportunities for global health.

Health is inextricably linked to climate change. It is important for clinicians to understand this relationship in order to discuss associated health risks with their patients and to inform public policy. To provide new US-based temperature projections from downscaled climate modeling and to review recent studies on health risks related to climate change and the cobenefits of efforts to mitigate greenhouse gas emissions. We searched PubMed and Google Scholar from 2009 to 2014 for articles related to climate change and health, focused on governmental reports, predictive models, and empirical epidemiological studies. Of the more than 250 abstracts reviewed, 56 articles were selected. In addition, we analyzed climate data averaged over 13 climate models and based future projections on downscaled probability distributions of the daily maximum temperature for 2046-2065. We also compared maximum daily 8-hour average ozone with air temperature data taken from the National Oceanic and Atmospheric Administration, National Climate Data Center. By 2050, many US cities may experience more frequent extreme heat days. For example, New York and Milwaukee may have 3 times their current average number of days hotter than 32°C (90°F). High temperatures are also strongly associated with ozone exceedance days, for example, in Chicago, Illinois. The adverse health aspects related to climate change may include heat-related disorders, such as heat stress and economic consequences of reduced work capacity; respiratory disorders, including those exacerbated by air pollution and aeroallergens, such as asthma; infectious diseases, including vectorborne diseases and waterborne diseases, such as childhood gastrointestinal diseases; food insecurity, including reduced crop yields and an increase in plant diseases; and mental health disorders, such as posttraumatic stress disorder and depression, that are associated with natural disasters. Substantial health and economic cobenefits could be associated with reductions in fossil fuel combustion. For example, greenhouse gas emission policies may yield net economic benefit, with health benefits from air quality improvements potentially offsetting the cost of US and international carbon policies. Evidence over the past 20 years indicates that climate change can be associated with adverse health outcomes. Health care professionals have an important role in understanding and communicating the related potential health concerns and the cobenefits from policies to reduce greenhouse gas emissions.

한반도 대도시의 폭염 및 열대야 발생 특성에 대한 연구

To identify the characteristics of extreme heat events and tropical nights in major cities, the correlations between automated synoptic observing station (ASOS), automatic weather station (AWS), and temperature in seven metropolitan areas were analyzed. Temperatures at ASOS were found to be useful sources of the reference temperature of each area. To set the standard for identifying dates of extreme heat events in relation to regional topography and the natural environment, the monthly and yearly frequency of extreme heat in each region was examined, based on the standards for extreme heat day (EHD), tropical night day (TND), and extreme heat and tropical night day (ETD). All three cases identified 1994 as the year with the most frequent heat waves. The frequency was low according to all three cases in 1993, 2003 and 2009. Meanwhile, the yearly rate of increase was the highest in 1994, followed by 2010 and 2004, indicating that the frequency of extreme heat changed significantly between 1993 and 1994, 2003 and 2004, and 2009 and 2010. Therefore all three indexes can be used as a standard for high temperature events. According to monthly frequency data for EHD, TND, and ETD, July and August accounted for 80% or more of the extreme heat of the entire year.

Identifying susceptible populations for public health action. Results from the PHASE project.

Background and aims: Extreme weather events (EWEs) have been increasing as a result of climate change. An objective of the European funded PHASE project, is to define subgroups of the population susceptible to EWEs such as heat waves, cold spells, floods, forest fires and air pollutants. Methods: Case-study analyses among PHASE cities were carried out to estimate the effects of EWEs and identify susceptible subgroups using different methodologies (time series, case cross over analysis and cohort approach). Where primary studies were not yet performed, a literature review was carried out to summarize susceptibility factors to EWEs. Results: Analyses from PHASE show: Heat. In the last decades, the effect of heat in the 65-74 age group is increasing while among the very old (75+ years) the effect is declining and there has also been a reduction in the harvesting effect. An effect of high temperatures among children was also observed, especially for respiratory diseases. Exposure to high temperatures increases the risk of preterm births (+2% for every 1°C increase). Among cohorts of adult patients within chronic diseases (Diabetes, COPD, MI survivors, CHF, Psychiatric disease) an increase in deaths during extreme heat days was observed. Floods. The indirect health effects of floods include respiratory disease, mental health, gastroenteritis; children and persons with chronic-related conditions are most at risk. Specific case studies within PHASE are ongoing. Air pollutionForest Fires. Through the use of satellite data, a EU map of the areas at-risk to fires was defined and an emissions inventory will allow to estimate the health effects of wild fires in selected case studies. The health effects of urban air pollution seem to be exacerbated during extreme temperatures, especially for respiratory and cardiovascular causes. Conclusions: Specific public health measures should be focused on subgroups that will suffer the greatest health burden through life as a consequence of exposure to EWEs. Results from the PHASE project on subgroups susceptible to EWEs need to be integrated in public health guidelines.

A time series approach for evaluating intra-city heat-related mortality

Extreme heat is a leading cause of weather-related mortality. Most research has considered the aggregate response of the populations of large metropolitan areas, but the focus of heat-related mortality and...

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

BackgroundThe 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.MethodsTotal 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.ResultsThe 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.ConclusionsThis 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

APPLICATION OF CLIMATE INDICATORS TO US CHILD POPULATION: TRENDS IN TEMPERATURE VARIABILITY

Background and Aims: Children may be particularly susceptible to climatic change, including extreme temperature. Childhood exposure and health effects of recent temperature extremes remain largely unknown. We highlight the development and initial evaluation of multiple climate indicators and their evaluation through linkage to child population counts to identify childhood exposure trends. Methods: County-level daily maximum and minimum temperature records from ~8,000 national weather stations (National Climatic Data Center) were geospatially and temporally-linked to US Census annual child population estimates (ages 0-17 years) for 2,311 US counties (~xx% of children). Indicators were developed by: (1) Defining a reference period, 1977-1987; (2) calculating 99th and 1st percentile thresholds of MAX and MIN temperature values for each month/county over the 11-year period; and (3) tabulating the days which exceeded hot and cold thresholds for our study period (1988-2008). Trends in childhood exposure to extreme temperature were stratified by month, season, year, and region. Results: Days exceeding the 99th percentile hot threshold varied greatly by month, decade, and region, with January experiencing the greatest increase in extreme heat days by decade and region (excluding Western US). Median number of days exceeding the 1st percentile cold threshold dramatically decreased by 85% from the 1980s to 2000s, even when stratified by season and region. There was a 26% increase in percentage of children from 1988-2008 exposed to heat exceeding the 99th percentile of reference period, and a decreased percentage of children exposed to unusually cold days. Conclusions: Since 1988, US children have been exposed to an increasing number of unusually hot days. Implications for short and long-term child health effects remain to be investigated. Application of climate indicators to national health databases (e.g. National Health Interview Survey) will further investigate children’s health implications of extreme temperature.

RISING WATER TEMPERATURES ALTER LIPID DYNAMICS AND REDUCE N-3 ESSENTIAL FATTY ACID CONCENTRATIONS IN SCENEDESMUS OBLIQUUS (CHLOROPHYTA)(1).

The biosynthesis of nutritionally important polyunsaturated fatty acids (PUFAs) in phytoplankton is influenced by environmental temperature. We investigated the potential of climate warming to alter lipid dynamics of Scenedesmus obliquus (Turpin) Kütz. by comparing lipid and fatty acid (FA) profiles as well as FA metabolism (using [1-(14) C] acetate) at 20°C and 28°C. We documented an overall decline (53%-37%) in the proportion of n-3 PUFA (in particular, of α-linolenic acid [ALA; 18:3n-3]), and a concomitant increase in saturated fatty acids (SAFAs) in total lipids (TLs) at 28°C, consistent with enhanced incorporation of radioactivity from [1-(14) C] acetate into total 16:0, 18:1, and decreased incorporation into 18:2 and 18:3 FA (from 36% to 22% of the total) at 28°C. Glycerophospholipids were also affected by warming; ALA and stearidonic acids (SDAs; 18:4n-3) both decreased (by 13% and 15%, respectively) in phosphatidylcholine (PC) and (by 24% and 20%, respectively) in phosphatidylethanolamine (PE). The characteristic FA in phosphatidylglycerol (PG; 16:1n-13t) increased (by 22%) at 28°C. The activities of desaturases, which add double bonds to FA moieties, comprised the major suite of reactions affected by the temperature increase in TL and polar lipid (PL) classes. Climate modelers predict an increase in the number of extreme heat days in summer at temperate latitudes, with parallel projected increases in water temperatures of shallow water bodies. Our results suggest that the overall decrease in the essential n-3 FA ALA in S. obliquus at higher water temperatures may lower food quality for higher tropic levels, adding another climate-warming stress.

(A109) Health Workforce and Disaster Preparedness of Rural Hospitals

Following the devastating March 2009 Victorian bushfire disaster in rural areas of Australia, authorities reviewed strategies designed to protect communities during periods of extreme fire risk. New policy and regulation were introduced and designed to ensure that small rural communities were protected and prepared to confront a wildfire emergency during days of extreme heat or bushfire risk weather. As a result on days of declared ‘catastrophic’ bushfire weather conditions government agencies in South Australia have implemented a policy for schools (including pre-schools) to be temporarily closed. On these days community members are advised to evacuate early to safe regional centres, and to limit travel on country roads. The WADEM Guidelines for Disaster Evaluation and Research demonstrate that Basic Societal Functions (BSFs), such as education, health, transport and others, are interconnected and interdependent. For example in small rural communities in South Australia people may have a number of important roles including being parents, volunteers of emergency services while also being employed as staff of local hospitals. This project reviewed the impact of school closures and other protective measures on the availability of the rural nursing workforce and on rural hospitals. Rural hospitals in Australia are staffed, on average, by 2–8 nurses, service very small communities and are separated by great distances. As a result, small changes in the absentee rate for nurses can have a significant impact on the operation of these hospitals. This paper will argue that policy changes in other sectors, such as education, can impact on societal activities such as childcare, volunteer emergency service work, and hospital staffing, in ways that may not be anticipated unless the impact on all Basic Societal Functions are considered by policymakers.

Identifying extreme hottest days from large scale upper air data: a pilot scheme to find California Central Valley summertime maximum surface temperatures

A pilot scheme uses upper air data from a few extreme hottest days to identify those and other extreme hottest days measured by 3 stations sampling the California Central Valley (CV). Prior work showed that CV extreme heat wave onsets have characteristic large scale patterns in many upper-air variables; those patterns also occur for the hottest days. A pilot scheme uses areas of two upper-air variables with high significance and consistency to forecast extreme surface temperatures. The scheme projects key parts of composite patterns for one or more variables onto daily weather maps of the corresponding variables resulting in a ‘circulation index’ for each day. The circulation index measures how similar the pattern on that day is to the composite patterns in areas dynamically relevant to a CV extremely hot day, with a larger value for a stronger match and larger amplitude. The scheme is tested on the development period (1979–1988) and on the subsequent 18 year ‘independent’ period (1989–2006). The pilot scheme captures about half of the rare events in the development period, with similar skill for the independent period. Based only on 16 days of extreme heat in the first 10 years, the scheme is not intended to represent the general distribution; however the circulation index has similar kurtosis, variance, and skewness as the observed maximum temperatures. Properties of the high end tail of the distribution are notably improved by adding the second predictor. The scheme outperforms simply using 850 hPa temperature above the CV.

The health impacts of heat waves in five regions of New South Wales, Australia: a case-only analysis

To determine and characterise the health impacts of extreme heat events on the population in five regions of New South Wales (NSW). Such data provide evidence necessary for the development of policy and programme initiatives designed to reduce the burden of disease due to the impact of climate change. A case-only approach was used to analyse 1,497,655 emergency hospital admissions in Sydney East and West, Illawarra, Gosford-Wyong and Newcastle. The distribution of daily minimum and maximum temperatures in each region was used to define extreme heat (≥99th percentile). We investigated the susceptibility of the main causes of emergency hospital admission to extreme heat. We also examined the presence of underlying conditions as a risk modifier of emergency hospital admission on extreme heat. Logistic regression model was used to estimate the effect modifications. Main causes: On days of extreme heat, the risk of emergency hospital admission due to heat-related injuries, dehydration and other disorders of fluid, electrolyte and acid-base balance increased more than the risk of admission from other causes. Underlying conditions: Those with underlying mental and behavioural disorders, diseases of nervous and circulatory system, especially cardiac, diseases of respiratory system, especially asthma and chronic obstructive pulmonary disease, neoplasms and renal disease, especially renal failure, were more susceptible to an extreme heat event. In this study, we identified several main diagnoses and underlying conditions for emergency hospital admission that are particularly susceptible to extreme heat events. This knowledge can contribute directly to establishing health programmes that would effectively target those with higher relative risk of emergency hospital admission due to extreme heat.

고온건강경보시스템 기준 설정에 관한 연구 ( II ) - 설정 기준 개선 -

The current standard level of Heat Health Watch Warning System consider both daily maximum temperature and daily maximum heat index(HI), but current standard could not consider daily maximum HI due to the difficulties in forecasting when we consider both daily maximum temperature and daily maximum HI and no considering HI because relative humidity could not observed for some regions. So, Newly established standard level of Heat Health Watch Warning System is based on daily maximum temperature exceeding for two consecutive days or daily minimum temperature exceeding and daily maximum temperature exceeding . These days are called heat days. On extreme heat days, the standard of extreme heat advisory is based on daily maximum temperature among exceeding and not exceeding , and extreme heat warning is based on daily maximum temperature exceeding . ANOVA analysis was carried out using the data of Seoul Metropolitan City in 1994 to check the robustness of the new standard level of Heat Health Watch Warning System from this study, in particular for mortality variable. The results reveal that the new standard specifies excess mortality well, showing significance level of 0.05 in the difference of excess mortality for each phase.

고온건강경보시스템 기준 설정에 관한 연구( I ) - 기준 설정 및 검증 -

This study investigates the standard, duration period and excess mortality of extreme heat using the stand- ardized daily mortality data from 1991 to 2004, establishing a standard threshold Criteria for Heat Health Watch Warning System in Korea. It ultimately aims to provide the guidance in building up Heat Health Watch Warning System for Korea by suggesting the standard to quantify thermal stress from heat. The standard thresh- old Criteria for Heat Health Watch Warning System for Seoul metropolitan city takes into account both daily maximum temperature and daily maximum heat index(HI) and consists of four phases; caution, extreme caution, danger, and extreme danger. Extreme caution phase and danger phase are used as the advisory and warning of extreme heat, respectively. Since the nationwide distribution of the frequency of extreme heat day and the excess mortality rate shows little difference across regions, the standard threshold Criteria for Heat Health Watch Warning System for Seoul metropolitan city can be used for other regions.