Observations indicated strong correlations between heat extremes and multiple health-stressors.
In this paper, using 15 years of surface observations over the eastern United States and Canada, the authors show that the extremes cluster together in often overlapping large-scale episodes, and that the largest episodes have the hottest temperatures and highest levels of pollution.
Exposure to extreme temperatures and high levels of the pollutants ozone and particulate matter poses a major threat to human health. Heat waves and pollution episodes share common underlying meteorological drivers and thus often coincide, which can synergistically worsen their health impacts beyond the sum of their individual effects. Furthermore, there is evidence that pollution episodes and heat waves will worsen under warmer conditions, making it imperative to understand the nature of their co-occurrence.
Heat waves and air pollution episodes pose a serious threat to human health and may worsen under future climate change. In this paper, we use 15 years (1999-2013) of commensurately 1°x1°- gridded surface observations of extended summer (April-September) surface ozone (O3), fine particulate matter (PM2.5), and maximum temperature (TX) over the eastern United States and Canada to construct a climatology of the coincidence, overlap, and lag in space and time of their extremes. Extremes of each quantity are defined climatologically at each grid cell as the 50 days with the highest values in three 5-yr windows (˜(95th %ile). Any two extremes (O3X, PMX, TXX) occur on the same day in the same grid cell more than 50% of the time in the northeastern United States. Many extremes show connectedness with consistent offsets in space and in time, which often defy traditional mechanistic explanations. All three extremes occur primarily in large-scale, multi-day, spatially connected episodes with scales of >1,000 km and clearly coincide with large-scale meteorological features. The largest, longest-lived episodes have the highest incidence of co-occurrence and contain extreme values well above even their local threshold (95th%), by +7 ppb for O3, +6 µg m-3 for PM2.5, and +1.7 °C for TX. The results demonstrate the need to evaluate these extremes as synergistic co-stressors to accurately quantify their impacts on human health.
Contacts (BER PM)
Earth System Modeling Program
The U.S. Department of Energy Office of Science, Biological and Environmental Research, Earth System Modeling
Schnell, JL; & Prather, MJ. (2017). Co-occurrence of extremes in surface ozone, particulate matter, and temperature over eastern North America.. Proceedings of the National Academy of Sciences of the United States of America, 114(11), 2854 - 2859. doi: 10.1073/pnas.1614453114. UC Irvine: 1817348. (Reference link)
SC-23.1 Climate and Environmental Sciences Division, BER
BER supports basic research and scientific user facilities to advance DOE missions in energy and environment. More about BER
Aug 24, 2019
New Approach for Studying How Microbes Influence Their Environment
A diverse group of scientists suggests a common framework and targeting of known microbial processes [more...]
Aug 08, 2019
Nutrient-Hungry Peatland Microbes Reduce Carbon Loss Under Warmer Conditions
Enzyme production in peatlands reduces carbon lost to respiration under future high temperatures. [more...]
Aug 05, 2019
Amazon Forest Response to CO2 Fertilization Dependent on Plant Phosphorus Acquisition
AmazonFACE Model Intercomparison. The Science Plant growth is dependent on the availabi [more...]
Jul 29, 2019
A Slippery Slope: Soil Carbon Destabilization
Carbon gain or loss depends on the balance between competing biological, chemical, and physical reac [more...]
Jul 15, 2019
Field Evaluation of Gas Analyzers for Measuring Ecosystem Fluxes
How gas analyzer type and correction method impact measured fluxes. The Science A side- [more...]
List all highlights (possible long download time)