New research conducted by a scientist from the University of Arkansas reports that climate change is increasing the intensity and possibility of heatwaves during adverse droughts in the southern plains and the southwest United States.
With the help of data acquired from the National Center for Atmospheric Research’s Community Earth System Model, assistant professor of geosciences Linyin Cheng investigated summer droughts both prior to and following the Industrial Revolution.
Cheng and teammates from the National Oceanic and Atmospheric Administration and universities in China and Colorado ran simulations to evaluate how, and to what extent, human-induced climate change influences summer heatwaves in the contiguous United States. The research has been reported in the Journal of Climate.
The investigators discovered that in regions with low moisture in the soil, for example, the southern plains and southwest, higher temperatures caused by climate change resulted in an increased “coupling” of land and atmosphere, which further elevated the intensity of heatwaves.
In regions with higher moisture in the soil, for example, the northeast, they found no considerable coupling and thus no contribution to heatwave intensification.
Our analysis of climate simulation finds that summertime drought-heatwave relationships change significantly over the southern and southwest U.S. due to man-made climate change since the late 19th century. By contrast, the drought-heatwave relationship over northern U.S regions undergoes little change in the warmed climate.
Linyin Cheng, Assistant Professor of Geosciences, University of Arkansas
The discoveries lead to the concept of a self-reinforcing climate loop: as a region’s climate turns drier because of climate change, droughts become hotter, further decreasing soil moisture.
“Overall, these results indicate that strengthened land-atmosphere feedback is a significant physical driver for increasing occurrences of drought-related extreme heatwaves, particularly over the semi-arid and arid regions of the United States,” the report describes.