Number Of Heat Waves Research Articles

Detecting synoptic warming trends across the US Midwest and implications to human health and heat‐related mortality

ABSTRACTThis paper highlights and expands on the extensive work concerning extreme heat events, and the environmental and societal factors that affect human health. Selections of this work were presented originally in a Union of Concerned Scientists public report (‘Heat in the Heartland’). As humans respond concomitantly to a suite of meteorological variables, we accordingly aim to examine summertime frequencies and characteristics of select synoptic weather types in the Midwestern United States, particularly those associated with elevated health impacts risk. We analyse five major urban centres, paired with five nearby smaller cities, to investigate the potential relative differences due to urban form and size. In virtually all of these locales, the frequency of health‐debilitating hot weather types has increased in the six most recent decades, with many of these also demonstrating statistically significant upward trends in air and dew point temperatures. This is most prevalent for overnight temperatures, where the hottest weather types display increasing overnight temperatures in both large and small cities, thus causing the diurnal temperature ranges to decrease. Furthermore, the prevalence of three or more consecutive runs of these days is on the rise, with all five large cities experiencing a higher number of heat waves today than in the late 1940s. We emphasize the importance of city‐level efforts to assist in minimizing future climate‐related health risks. Finally, we demonstrate the increasing human mortality response in one select city (Detroit, MI), which is estimated without the presence of city‐level efforts, targeted interventions, adaptation strategies, or physiological acclimatization. This highlights the importance of providing accurate heat‐health warnings to the public, and provides essential understanding of the Midwest US region's summertime climate trends.

Impact of heat waves on excess mortality in 2011 and 2012 in Hungary

Background/Aims: According to the IPCC the rate of excess mortality due to the increased number of heat waves in relation to climate change can be predicted in the future in Europe. In this study we analyse the heat related excess mortality of the last two years with special care taking into account extreme summer of 2007 in Hungary. Methods: Daily temperature data were gained from the Hungarian Meteorological Service. The daily all cause mortality data at a weekly frequency were provided by the Central Office for Administrative and Electronic Public Services. Excess mortality was calculated for the country, for Budapest and for the seven regions as the difference of the daily mortality on days with mean temperature >25°C and >27°C (2nd and 3rd level of heat alert) and the average mortality on cooler days in the summer periods of 2011 and 2012. Excess mortality was computed also by age groups and sex. Results: In 2011, excess mortality was 5.4% on country level during the 2nd level heat alert, and 17.4% during the 3rd level. The highest excess mortality was 23% in the Central Hungarian Region. 593 excess death cases were registered during the 14 days of heat alerts in 2011. In 2012 the excess mortality was 33% in the Capital during the 3rd level of heat alert (13 days). 1666 excess death cases (27%) could be attributed to the 26 days of the four heat alerts at country level. In both years female mortality during the heat alerts was higher, the difference was bigger during the 3rd level of alerts. The mortality of 0-64 and 65-74 years was very similar, while almost twice as much elderly died during the heat alerts than in the younger age groups. Conclusion: In spite of the heat alert system in Hungary, the intensive heat waves cause great number of excess deaths with a maximum 2012 (1666 cases) during the last 10 years. More effective measures are necessary to decrease heat related excess mortality. The study was supported by the project PHASE - Public Health Adaptation Strategies to extreme weather Events - DG-Sanco 20101103.

Hotter days and droughts to continue through the 21st century

As heat waves become more frequent and droughts cause famines and drive up food prices, climate policies will need to account for changes in extremes in temperature and precipitation, as global mean temperatures continue to rise through the 21st century. Using HadGEM2, a new ocean‐atmosphere coupled climate model, Caesar and Lowe investigated the effects of different greenhouse gas emissions scenarios on maximum and minimum air temperatures as well as on the amounts of rainfall in different parts of the world. The authors compared two scenarios through the 21st century, the first one with an aggressive mitigation scenario, in which global emissions begin to decrease in the early 21st century and reach nearly zero by 2100; the second scenario had no mitigation. The researchers' results show that extreme temperatures would scale with increasing mean temperature, at least until the middle of the 21st century: As air temperatures increase, countries across the globe would experience hotter days and an increasing number of heat waves, even with aggressive mitigation. However, mitigation may provide some amelioration, particularly through the second half of the 21st century; the northern midlatitudes would benefit most from mitigation measures, although northern South America and parts of the United States, Africa, and Asia could also avoid large increases in extreme temperature maxima by following similar mitigation policies.

Summer heat waves over western Turkey between 1965 and 2006

Global warming is one of the greatest environmental, economic, and social threats in the world. There are many assessments to estimate climate variability over many regions. A change in the Earth’s surface temperature leads to increase in extreme temperature events, which are harmful to the ecosystem, and moreover, they create danger on human health. In this study, we have selected the western part of Turkey as the study area, since climate change projections for Turkey point out that the highest temperature change can be expected on this region during summer, and the Turkish population is very dense here to be affected by extreme events. We have used apparent temperatures to define the heat waves which we have determined their frequencies for the summer months (June–August) of 1965–2006. Since the regional comparisons of station results are intended, we selected the 90th percentile value for each station as a threshold value to be used in the delineation of heat waves. Then, the number of heat waves is determined by imposing the constraint that apparent temperatures stay above the threshold value at least for three consecutive days. Then, the changes in the number of hot days and heat waves and also their durations are analyzed by using the linear least square method. We have found that the number of hot days, heat waves, and heat wave durations is increased between 1965 and 2006 on the western part of Turkey. Additionally, their rate of change is larger within the last decade and extremes are frequently observed after 1998. Regional distributions show that the tendency of the number of heat wave events increases towards the southern latitudes of the domain. Moreover, we investigated the relationship between the number of hot days and the sea surface temperatures of the Mediterranean Sea and Black Sea. Correlation analyses are carried out by the number of hot days and averaged sea surface temperatures on the regions of the western, central, and eastern Mediterranean Sea and the Black Sea. It is found that the number of hot days of west Turkey is better correlated with the sea surface temperatures averaged over eastern Mediterranean and Black Seas. The number of heat waves is found significantly correlated with the fire occurrences for most of the stations.

A Population-Based Case–Control Study of Extreme Summer Temperature and Birth Defects

Background: Although hyperthermia is a recognized animal teratogen and maternal fever has been associated with birth defects in humans, data on the relationship between high environmental temperatures and birth defects are limited.Objective: To determine whether pregnancies are potentially vulnerable to the weather extremes anticipated with climate change, we evaluated the relationship between extreme summer temperature and the occurrence of birth defects.Methods: We performed a population-based case–control study by linking the New York State Congenital Malformations Registry to birth certificates for the years 1992–2006. We selected nonmalformed infants from a 10% random sample of live births as controls. We assigned meteorologic data based on maternal residence at birth, summarized universal apparent temperature (UAT; degrees Fahrenheit) across the critical period of embryogenesis, and estimated adjusted odds ratios (aOR) and 95% confidence intervals (CI) with multivariable logistic regression, controlling for confounders available on the birth certificate.Results: Among 6,422 cases and 59,328 controls that shared at least 1 week of the critical period in summer, a 5-degree increase in mean daily minimum UAT was significantly associated with congenital cataracts (aOR = 1.51; 95% CI: 1.14, 1.99). Congenital cataracts were significantly associated with all ambient temperature indicators as well: heat wave, number of heat waves, and number of days above the 90th percentile. Inconsistent associations with a subset of temperature indicators were observed for renal agenesis/hypoplasia (positive) and anophthalmia/microphthalmia and gastroschisis (negative).Conclusions: We found positive and consistent associations between multiple heat indicators during the relevant developmental window and congenital cataracts which should be confirmed with other data sources.

Influence of local factors in the relationship between mortality and heat waves: Castile-La Mancha (1975–2003)

IntroductionAll the climate-change studies undertaken to date agree that one of the principal consequences of this phenomenon is the increase in heat waves, which, without exception, are linked to marked rises in mortality. The characteristics that modulate and determine the relationship between high temperatures and health must therefore be ascertained in the greatest possible detail, so that really effective prevention plans can be designed to address temperature extremes. MethodsWe examined the effect of heat waves on daily non-accidental-cause mortality across all age groups in the Castile-La Mancha region (Spain) from 1975 to 2003. Quantitative analyses were performed using autoregressive integrated moving average (ARIMA) models, with other covariates, such as pressure trends, relative humidity, and duration and chronological number of heat waves. ResultsMortality increased significantly with respect to the mean, when temperatures exceeded the designated provincial thresholds in Castile-La Mancha. For each degree centigrade that temperatures exceeded these thresholds, the percentage increase in mortality amounted to increases of approximately 12% over the daily mean, albeit with clear provincial variations. The longest heat waves were associated with daily mortality, with those at the end of summer causing the lowest mortality. Meteorological situations most closely associated with increases in mortality were cyclonic conditions accompanied by low humidity. ConclusionsSpatio-temporal variability in the temperature–mortality relationship must be studied in order to enable really effective heat-wave prevention plans to be drawn up. The influence of variables, such as heat-wave duration or time of appearance, is important in the total increase in mortality during temperature extremes. Since parameters, such as humidity or pressure trends, can play very different roles in different geographical settings, they should be analysed separately from temperature.

Climate change impacts on two high-elevation hydropower systems in California

This paper describes research to estimate the effects of climate change on two high-elevation hydropower systems in California: the Upper American River Project, operated by the Sacramento Municipal Utility District, and the Big Creek system, operated by Southern California Edison. The study builds on a previous model of the Upper American River Project, which is here modified and extended for use to simulate two hydropower systems under various conditions. Future operations of the two high-elevation systems are simulated using climate change scenarios provided for the Second California Assessment. These scenarios suggest reduced precipitation and reduced runoff for both systems, and a shift toward runoff earlier in the year. The change in the hydrograph is somewhat greater for the Upper American River Project system, because its basins lie at a lower elevation. Reduced runoff directly reduces energy generation and revenues from both systems. Because the Upper American River Project system is projected to have greater spills with warmer climate conditions, it also has greater reduction in energy generation and revenues. Both systems continue to meet peak historical power demands in summer under most climate projections. However, if the number of heat waves increases in the late summer (September), reservoir operating strategies may need to be modified.

Urinary Incontinence, Hyperthermia, and Sudden Death

An 84-year-old woman is reported whose death was associated with strenuous exercise on an extremely hot day (maximum temperature=43.1 °C, 109.6 °F). At autopsy there was evidence of exposure to high environmental temperatures with early putrefactive changes and mummification. There was underlying cardiomegaly with mild pulmonary emphysema. No significant injuries were detected. Toxicology revealed therapeutic levels of oxybutynin prescribed for urinary stress incontinence. Death was considered to be heat related, exacerbated by oxybutynin therapy, exercise, and cardiomegaly. Given that it has been predicted that there may be an increase in the number of heatwaves and in their intensity and duration, it is possible that such cases may be encountered more often in future. The assessment of all deaths occurring during conditions of extreme heat will require consideration of postmortem toxicology, particularly if there are underlying conditions such as stress incontinence that may be associated with anticholinergic drug therapy.

Trends and Extremes Analysis of Daily Weather Data from a Site in the Capitanata Plain (Southern Italy)

The impacts of the climate change for agriculture is an ambitious and unresolved topic due to the complexity of the natural phenomena. The high variability of the Mediterranean basin does not allow us to generalize with enough certainty the results obtained from other researches and other locations. Therefore, a site specific analysis in Capitanata plain was conducted. The aim is to provide a detailed picture of recent change in climate regime in one of the most important agricultural area of South Italy. Climate analysis was carried out and several indices of extreme events were studied on the basis of temperature and precipitation observations registered at experimental station ‘Podere 124’ (CRA-SCA). The period under study is 1979-2008. Increasing trends were identified for the summer season with an intensification of the number of heat waves.

Lindernia procumbens in Poland: the relationship between weather conditions and the occurrence of the species

Lindernia procumbens in Poland: the relationship between weather conditions and the occurrence of the species New data regarding the occurrence of Lindernia procumbens (prostrate false pimpernel) are discussed and its current geographical range in Poland is given. A comparison of its past and present distribution in Poland indicates an advancement of the distribution limit northwards, which may be caused by climate changes, mostly, by an increased number of heat waves in the warm half-year. The relationship between the occurrence of the species and specific meteorological conditions, especially, unusually hot and dry summer periods, is analysed using long-term meteorological surveys.

Climate Change, Heat Waves, and Environmental Justice: Advancing Knowledge and Action

Abstract Knowledge about climate change and the increasing number of heat waves in the United States has caused researchers and public health officials to recognize the need for new methods and too...

Summer heat waves over western Europe 1880–2003, their relationship to large-scale forcings and predictability

We investigate the large-scale forcing and teleconnections between atmospheric circulation (sea level pressure, SLP), sea surface temperatures (SSTs), precipitation and heat wave events over western Europe using a new dataset of 54 daily maximum temperature time series. Forty four of these time series have been homogenised at the daily timescale to ensure that the presence of inhomogeneities has been minimised. The daily data have been used to create a seasonal index of the number of heat waves. Using canonical correlation analysis (CCA), heat waves over western Europe are shown to be related to anomalous high pressure over Scandinavia and central western Europe. Other forcing factors such as Atlantic SSTs and European precipitation, the later as a proxy for soil moisture, a known factor in strengthening land–atmosphere feedback processes, are also important. The strength of the relationship between summer SLP anomalies and heat waves is improved (from 35%) to account for around 46% of its variability when summer Atlantic and Mediterranean SSTs and summer European precipitation anomalies are included as predictors. This indicates that these predictors are not completely collinear rather that they each have some contribution to accounting for summer heat wave variability. However, the simplicity and scale of the statistical analysis masks this complex interaction between variables. There is some useful predictive skill of summer heat waves using multiple lagged predictors. A CCA using preceding winter North Atlantic SSTs and preceding January to May Mediterranean total precipitation results in significant hindcast (1972–2003) Spearman rank correlation skill scores up to 0.55 with an average skill score over the domain equal to 0.28 ± 0.28. In agreement with previous studies focused on mean summer temperature, there appears to be some predictability of heat wave events on the decadal scale from the Atlantic Multidecadal Oscillation (AMO), although the long-term global mean temperature is also well related to western European heat waves. Combining these results with the observed positive trends in summer continental European SLP, North Atlantic SSTs and indications of a decline in European summer precipitation then possibly these long-term changes are also related to increased heat wave occurrence and it is important that the physical processes controlling these changes be more fully understood.

The temporal and spatial patterns of thermal conditions in the area of the southwestern coast of the Gulf of Gdańsk (Poland) from 1951 to 1998

AbstractThe variability of the thermal conditions in the environs of the southwestern coast of the Gulf of Gdańsk in the years 1951–98 has been analysed. The analyses were based on air temperature series from four stations characteristic of different locations. During the years analysed, the increase in minimum temperature was stronger than that of the maximum temperature; thus, a negative trend in the daily temperature range is observed. In the city, the statistically significant decrease in the daily temperature range is estimated as 0.015°C per annum. Mean values of both extreme temperatures indicate the thermally privileged areas, where stronger influences of local anthropogenic factors occur. The variability of heat and cold waves shows a positive trend in the number of heat waves and a negative trend for cold waves. The duration of heat waves is increasing. The duration of cold waves is characterized by a negative trend. Canonical correlation analysis was used to study the relationship between regional atmospheric circulation and local thermal conditions. The first two pairs of canonical maps explain 84% of the variance of the local daily temperature range and confirm the role of local factors in a differentiation of the thermal conditions. Copyright © 2004 Royal Meteorological Society