scholarly journals A Climatology of Heat Waves from a Multimillennial Simulation

2007 ◽  
Vol 20 (15) ◽  
pp. 3802-3821 ◽  
Author(s):  
B. G. Hunt
Keyword(s):  
Time Series ◽  
Surface Temperature ◽  
Heat Wave ◽  
Heat Waves ◽  
The United States ◽  
Extreme Heat ◽  
Temperature Anomalies ◽  
Enso Events ◽  
Rainfall Anomalies ◽  
Temporal Events

Abstract A 10 000-yr unforced simulation with the Commonwealth Scientific and Industrial Research Organisation (CSIRO) Mark 2 coupled global climatic model has been used to investigate the occurrence of heat waves over the globe. Results are presented for both seasonal (summer mean) and daily heat waves. Geographical distributions of the occurrence rates of these heat waves are shown for various magnitudes of surface temperature anomalies. The heat waves have specific geographical preferences with regions where relatively frequent, intense, and long-lasting heat waves occur. Time series over all 10 000 yr of the heat waves for the selected model grid boxes illustrate the differing temporal variabilities at these locations, as well as identifying the occurrences of extreme heat waves. To this end, the observed European heat wave of 2003 was simulated remarkably well in its overall characteristics; it occurs once in this simulation. Heat waves for various continental locations are shown to occur as isolated spatial and temporal events, and not as part of larger-scale systems over continental-size domains, suggesting stochastic forcing as a contributor to the initiation of the heat waves. Regional plots of selected heat waves at monthly intervals illustrated the considerable spatial variability, progression, and variation in the intensity of the heat waves. Comparison of year-long daily surface temperature anomalies for heat-wave years for simulated and observed conditions at individual model grid boxes indicated substantial agreement, while spatial plots permitted the progress of a short-term heat wave over the United States to be followed. Multidecadal time series plots of intense heat waves also showed basic similarities between the simulation and observations, despite the brevity of the latter. The simulated time series suggest that more extreme heat waves than currently are observed, owing to the brevity of the observations, may be a possibility as a consequence solely of natural variability. An examination of the physical processes associated with a heat wave showed mutually consistent climatic relationships, such that a heat wave was associated with reduced rainfall and consequently reduced soil moisture content, evaporation, and cloud cover, and increased insolation at the surface. These combined changes created the surface temperature increase intrinsic to the heat wave. All heat waves examined for different regions experienced negative rainfall anomalies prior to a heat wave. The cause of these rainfall anomalies was not readily apparent. While an ENSO influence on heat waves is shown to exist in the simulation, not all ENSO events produce heat waves, suggesting that stochastic influences may determine when a major heat wave occurs in conjunction with these events. The limitations of the adequacy of the model ENSO may, however, have had an influence in this regard.

scholarly journals A Process-Oriented Approach to Identify Evolutions of Sea Surface Temperature Anomalies with a Time-Series of a Raster Dataset

2021 ◽  
Vol 10 (8) ◽  
pp. 500
Author(s):  
Lianwei Li ◽  
Yangfeng Xu ◽  
Cunjin Xue ◽  
Yuxuan Fu ◽  
Yuanyu Zhang
Keyword(s):  
Time Series ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Global Climate ◽  
Sea Surface ◽  
Temperature Anomalies ◽  
Global Climate Changes ◽  
Space And Time ◽  
Novel Approach ◽  
Sea Surface Temperature Anomalies

It is important to consider where, when, and how the evolution of sea surface temperature anomalies (SSTA) plays significant roles in regional or global climate changes. In the comparison of where and when, there is a great challenge in clearly describing how SSTA evolves in space and time. In light of the evolution from generation, through development, and to the dissipation of SSTA, this paper proposes a novel approach to identifying an evolution of SSTA in space and time from a time-series of a raster dataset. This method, called PoAIES, includes three key steps. Firstly, a cluster-based method is enhanced to explore spatiotemporal clusters of SSTA, and each cluster of SSTA at a time snapshot is taken as a snapshot object of SSTA. Secondly, the spatiotemporal topologies of snapshot objects of SSTA at successive time snapshots are used to link snapshot objects of SSTA into an evolution object of SSTA, which is called a process object. Here, a linking threshold is automatically determined according to the overlapped areas of the snapshot objects, and only those snapshot objects that meet the specified linking threshold are linked together into a process object. Thirdly, we use a graph-based model to represent a process object of SSTA. A node represents a snapshot object of SSTA, and an edge represents an evolution between two snapshot objects. Using a number of child nodes from an edge’s parent node and a number of parent nodes from the edge’s child node, a type of edge (an evolution relationship) is identified, which shows its development, splitting, merging, or splitting/merging. Finally, an experiment on a simulated dataset is used to demonstrate the effectiveness and the advantages of PoAIES, and a real dataset of satellite-SSTA is used to verify the rationality of PoAIES with the help of ENSO’s relevant knowledge, which may provide new references for global change research.

Abstract P069: Heat, Heat Waves and Hospital Admissions in Indianapolis, Indiana

Circulation ◽  
2017 ◽  
Vol 135 (suppl_1) ◽  
Author(s):  
Yi Wang
Keyword(s):  
Myocardial Infarction ◽  
Heart Failure ◽  
Relative Risk ◽  
Heat Wave ◽  
Hospital Admissions ◽  
Heat Waves ◽  
Global Climate ◽  
Extreme Heat ◽  
Apparent Temperature ◽  
The Impact

Background: The association between heat and hospital admissions is well studied, but in Indiana where the regulatory agencies cites lack of evidence for global climate change, local evidence of such an association is critical for Indiana to mitigate the impact of increasing heat. Methods: Using a distributed-lag non-linear model, we studied the effects of moderate (31.7 °C or 90 th percentile of daily mean apparent temperature (AT)), severe (33.5 °C or 95 th percentile of daily mean apparent temperature (AT)) and extreme (36.4 °C or 99 th percentile of AT) heat on hospital admissions (June-August 2007-2012) for cardiovascular (myocardial infarction, myocardial infarction, heart failure) and heat-related diseases in Indianapolis, Indiana located in Marion County. We also examined the added effects of moderate heat waves (AT above the 90 th percentile lasting 2-6 days), severe heat waves (AT above the 95 th percentile lasting 2-6 days) and extreme heat waves (AT above the 99 th percentile lasting 2-6 days). In sensitivity analysis, we tested robustness of our results to 1) different temperature and lag structures and 2) temperature metrics (daily min, max and diurnal temperature range). Results: The relative risks of moderate heat, relative to 29.2°C (75 th percentile of AT), on admissions for cardiovascular disease (CVD), myocardial infarction (MI), heart failure (HF), and heat-related diseases (HD) were 0.98 (0.67, 1.44), 6.28 (1.48, 26.6), 1.38 (0.81, 2.36) and 1.73 (0.58, 5.11). The relative risk of severe heat on admissions for CVD, MI, HF, and HD were 0.93 (0.60, 1.43), 4.46 (0.85, 23.4), 1.30 (0.72, 2.34) and 2.14 (0.43, 10.7). The relative risk of extreme heat were 0.79 (0.26, 2.39), 0.11 (0.087, 1.32), 0.68 (0.18, 2.61), and 0.32 (0.005, 19.5). We also observed statistically significant added effects of moderate heat waves lasting 4 or 6 days on hospital admission for MI and HD and extreme heat waves lasting 4 days on hospital admissions for HD. Results were strengthened for people older than 65. Conclusions: Moderate heat wave lasting 4-6 days were associated with increased hospital admissions for MI and HD diseases and extreme heat wave lasting 4 days were associated with increased admissions for HD.

Extreme Heat

2021 ◽  
Keyword(s):  
Heat Wave ◽  
Global Climate ◽  
Geographic Location ◽  
Weather Conditions ◽  
The United States ◽  
Extreme Heat ◽  
Local Climate ◽  
Extreme Heat Events ◽  
The World ◽  
Heat Events

Extreme heat events (EHEs) are periods of high temperatures and humidity that are considered to be unusual for a specific geographic location. For example, in 1995 an extended heat wave in Chicago, Illinois, in the United States was blamed for the deaths of 550 citizens. Most of the dead were elderly, poor individuals who may not have realized that heat could kill, or who had no means of mitigating the rising temperatures in their homes or any way to escape to a cooler environment. In 2003, Europe was subjected to an EHE that is estimated to have resulted in the deaths of 70,000, with 15,000 of those deaths in Paris, France. “Extreme heat” is a relative term. Individuals adapt to their local climate, so it is difficult to use an absolute number to describe the conditions meteorologists consider a relative change from past conditions. The Centers for Disease Control and Prevention (CDC) defines extreme heat as “summertime temperatures that are substantially hotter and/or more humid than average for location at that time of year.” According to the Public Health Institute’s Center for Climate Change, the state of California defines extreme heat days as those days above the 98th percentile of maximum temperatures based on 1961–1990 data for a specific location. Crucial to understanding extreme heat events is the collection of data about temperature and humidity. The US Global Change Research Program provides heat wave data spanning 1961 to 2018. The site links to a variety of programs related to global climate modeling. The National Resources Defense Council is a nongovernmental organization that has excellent maps which show change over time in the frequency of extreme heat events that overlay the human impact of these events. The National Centers for Environmental Information provides graphic data of current weather conditions along with lists of significant climate anomalies. The site has links to weather records and tools. All of these sites rely on the National Oceanic and Atmospheric Administration for their data. There are equivalent agencies all over the world. The World Meteorological Organization, part of the United Nations, is also a valuable resource for data.

scholarly journals An Analysis of the Prevalence of Heat Waves in the United States between 1948 and 2015

2018 ◽  
Vol 57 (7) ◽  
pp. 1535-1549 ◽  
Author(s):  
Evan M. Oswald
Keyword(s):  
United States ◽  
Heat Wave ◽  
Great Plains ◽  
Heat Waves ◽  
Estimation Method ◽  
The United States ◽  
Northern Great Plains ◽  
Strong Increase ◽  
Climate Data ◽  
Nighttime Temperatures

AbstractUnusually hot weather is a major concern to public health as well as other systems (e.g., ecological, economical, energy). This study utilized spatially continuous and homogenized observational surface climate data to examine changes in the regularity of heat waves in the continental United States. This included the examination of heat waves according only to daytime temperatures, nighttime temperatures, and both daytime and nighttime temperatures. Results confirmed a strong increase in the prevalence of heat waves between the mid-1970s and the dataset end (2015), and that increase was preceded by a mild decrease since the dataset beginning (1948). Results were unclear whether the prevalence of nighttime or simultaneous daytime–nighttime heat waves increased the most, but it was clear that increases were largest in the summer. The largest gains occurred in the West and Southwest, and a “warming hole” was most conspicuous in the northern Great plains. The changes in heat wave prevalence were similar to changes in the mean temperatures, and more so in the daytime heat waves. Daytime and nighttime heat waves coincided with one another more frequently in recent years than they did in the 1970s. Some parts of the United States (West Coast) were more likely than other parts to experience daytime and nighttime heat waves simultaneously. While linear trends were not sensitive to the climate dataset, trend estimation method, or heat wave definition, they were mildly sensitive to the start and end dates and extremely sensitive to the climate base period method (fixed in time or directly preceding any given heat wave).

scholarly journals Excess Mortality in Istanbul during Extreme Heat Waves between 2013 and 2017

2019 ◽  
Vol 16 (22) ◽  
pp. 4348 ◽  
Author(s):  
Günay Can ◽  
Ümit Şahin ◽  
Uğurcan Sayılı ◽  
Marjolaine Dubé ◽  
Beril Kara ◽  
...  
Keyword(s):  
Heat Wave ◽  
Excess Mortality ◽  
Intervention Studies ◽  
Heat Waves ◽  
Epidemiological Studies ◽  
Extreme Heat ◽  
Mortality And Morbidity ◽  
Climate Simulations ◽  
Morbidity Risks ◽  
Excess Deaths

Heat waves are one of the most common direct impacts of anthropogenic climate change and excess mortality their most apparent impact. While Turkey has experienced an increase in heat wave episodes between 1971 and 2016, no epidemiological studies have examined their potential impacts on public health so far. In this study excess mortality in Istanbul attributable to extreme heat wave episodes between 2013 and 2017 is presented. Total excess deaths were calculated using mortality rates across different categories, including age, sex, and cause of death. The analysis shows that three extreme heat waves in the summer months of 2015, 2016, and 2017, which covered 14 days in total, significantly increased the mortality rate and caused 419 excess deaths in 23 days of exposure. As climate simulations show that Turkey is one of the most vulnerable countries in the Europe region to the increased intensity of heat waves until the end of the 21st century, further studies about increased mortality and morbidity risks due to heat waves in Istanbul and other cities, as well as intervention studies, are necessary.

scholarly journals Heat Vulnerability and Heat Island Mitigation in the United States

Atmosphere ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 558 ◽  
Author(s):  
Jungmin Lim ◽  
Mark Skidmore
Keyword(s):  
United States ◽  
Local Governments ◽  
Heat Waves ◽  
Fold Increase ◽  
The United States ◽  
Extreme Heat ◽  
Mitigation Measures ◽  
Heat Island ◽  
Weather Extremes ◽  
Heat Vulnerability

Heat waves are the deadliest type of natural hazard among all weather extremes in the United States. Given the observed and anticipated increase in heat risks associated with ongoing climate change, this study examines community vulnerability to extreme heat and the degree to which heat island mitigation (HIM) actions by state/local governments reduce heat-induced fatalities. The analysis uses all heat events that occurred over the 1996–2011 period for all United States counties to model heat vulnerability. Results show that: (1) Higher income reduces extreme heat vulnerability, while poverty intensifies it; (2) living in mobile homes or rental homes heightens susceptibility to extreme heat; (3) increased heat vulnerability due to the growth of the elderly population is predicted to result in a two-fold increase in heat-related fatalities by 2030; and (4) community heat island mitigation measures reduce heat intensities and thus heat-related fatalities. Findings also show that an additional locally implemented measure reduces the annual death rate by 15%. A falsification test rules out the possibility of spurious inference on the life-saving role of heat island mitigation measures. Overall, these findings inform efforts to protect the most vulnerable population subgroups and guide future policies to counteract the growing risk of deadly heat waves.

Heat Waves and Innovation in Air Conditioning in the United States

2021 ◽  
Keyword(s):  
United States ◽  
Air Conditioning ◽  
Heat Waves ◽  
Heat Exposure ◽  
The United States ◽  
Extreme Heat ◽  
Weather Data ◽  
County Level ◽  
Similar Increase ◽  
Patent Data

AbstractThis study investigates whether extreme heat episodes (heatwaves) have contributed to the development of air conditioning technology in the United States. To this end we use weather data to identify days at which heat and relative humidity were above levels comfortable to the human body, and match these with patent data at the county level for nearly a hundred years. We find that in the two years after a county has experienced extreme heat air-conditioning patents increase. Overall, average extreme heat exposure results in an increase of 7.5% greater innovation. We find no similar increase in the frequency of non-air conditioning related patent filings, and therefore conclude that heatwaves result in innovation targeting their mitigation.

Mechanisms Associated with Daytime and Nighttime Heat Waves over the Contiguous United States

2020 ◽  
Vol 59 (11) ◽  
pp. 1865-1882
Author(s):  
Natalie P. Thomas ◽  
Michael G. Bosilovich ◽  
Allison B. Marquardt Collow ◽  
Randal D. Koster ◽  
Siegfried D. Schubert ◽  
...  
Keyword(s):  
United States ◽  
Human Health ◽  
Heat Wave ◽  
Heat Waves ◽  
The United States ◽  
Daily Maximum ◽  
Local Threshold ◽  
Dry Conditions ◽  
Heat And Moisture ◽  
Climate Events

AbstractHeat waves are extreme climate events that have the potential to cause immense stress on human health, agriculture, and energy systems, so understanding the processes leading to their onset is crucial. There is no single accepted definition for heat waves, but they are generally described as a sustained amount of time over which temperature exceeds a local threshold. Multiple different temperature variables are potentially relevant, because high values of both daily maximum and minimum temperatures can be detrimental to human health. In this study, we focus explicitly on the different mechanisms associated with summertime heat waves manifested during daytime hours versus nighttime hours over the contiguous United States. Heat waves are examined using the National Aeronautics and Space Administration Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2). Over 1980–2018, the increase in the number of heat-wave days per summer was generally stronger for nighttime heat-wave days than for daytime heat-wave days, with localized regions of significant positive trends. Processes linked with daytime and nighttime heat waves are identified through composite analysis of precipitation, soil moisture, clouds, humidity, and fluxes of heat and moisture. Daytime heat waves are associated with dry conditions, reduced cloud cover, and increased sensible heating. Mechanisms leading to nighttime heat waves differ regionally across the United States, but they are typically associated with increased clouds, humidity, and/or low-level temperature advection. In the midwestern United States, enhanced moisture is transported from the Gulf of Mexico during nighttime heat waves.

Refined assessment of urban residents' exposure to extreme temperatures across the United States

2020 ◽  
Author(s):  
Jiachuan Yang ◽  
Leiqiu Hu
Keyword(s):  
United States ◽  
Population Dynamics ◽  
Heat Waves ◽  
The United States ◽  
Extreme Weather ◽  
Extreme Heat ◽  
Cold Wave ◽  
Urban Residents ◽  
Extreme Temperatures ◽  
Spatiotemporal Population Dynamics

<p>Extreme temperatures during heat and cold waves are severe health hazards for humans. Residents’ exposure controls the susceptibility of the urban population to these hazards, yet the spatiotemporal population dynamics has been long overlooked in assessing the risk. In this study, we conducted comparative analysis over 16 major urban habitats under three massive heat waves and one cold wave across the contiguous United States. Incorporating WRF weather simulations with commute-adjusted population profiles, we found that the interaction between population dynamics and urban heat islands makes residents exposed to higher temperatures under extreme weather. After accounting for diurnal population movement, urban residents’ exposure to heat waves is intensified by 2.0 ± 0.8 <sup>o</sup>C (mean ± standard deviation among cities), and their exposure to cold wave is attenuated by 0.4 ± 0.8 <sup>o</sup>C. The aggravated exposure to extreme heat is more than half of the heat wave hazard (temperature anomaly 3.7 ± 1.5 <sup>o</sup>C). The underestimated exposure to extreme heat needs to be taken into serious consideration, especially in nighttime given the evident trend of observed nocturnal warming. Results suggest that the major driver for modified exposure to heat waves is the spatial temperature variability, i.e., residents’ exposure is more likely to be underestimated in a spread-out city. The current release of warnings for hazardous extreme weather is usually at the weather forecast zone level, and our analysis demonstrates that such service can be improved through considering spatiotemporal population dynamics. The essential role of population dynamics should also be emphasized in temperature-related climate adaptation strategies for effective and successful interventions.</p>

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