Study investigates how climate change affects summertime hot droughts in the Southern Great Plains
Droughts and heatwaves often go hand-in-hand, but how a warming climate might affect their inter-relationship remains uncertain. NOAA and CIRES researchers from the ESRL Physical Sciences Laboratory are co-authors of a new study recently published in the Journal of Climate, which evaluates how, and by how much, human-caused climate change affects summertime hot drought events over the contiguous United States. The researchers conduct climate model simulations which demonstrate an intensification of heat waves during drought.
The study finds that anthropogenic warming leads to enhanced soil moisture–temperature coupling in semi-arid areas of the United States, especially the Southern Plains and Southwest U.S. The resulting greater feedback of the land surface on air temperatures acts to intensify heat waves during droughts. This warming is beyond the increase in heatwave intensities occurring simply from an overall warming trend accompanying climate change. Their results reveal a further temperature increase of comparable magnitude arising during severe droughts due to increased soil moisture feedbacks when soils are dry. This strengthened coupling accounts for a substantial fraction of the overall rising temperatures related to the long-term climate change in their model experiments, highlighting the importance of changes in land–atmosphere feedback in a warmer climate.
This study takes a step toward increasing knowledge on drought–heat wave interactions in a warming world, presenting evidence that such events may become especially severe in semi-arid regions, both in terms of their frequency and intensity. The researchers expect that these preliminary findings will be important to facilitate better communication with risk managers who are seeking to better understand how climate change exposes vulnerabilities of human health, water supply, and agricultural productivity, all susceptible to compound drought heat waves.
The authors of Physical understanding of human-induced changes in U.S. hot droughts using equilibrium climate simulation are: Linyin Cheng of the University of Arkansas, Martin Hoerling and Jon Eischeid of the ESRL Physical Sciences Laboratory, and Zhiyong Liu of Sun Yat-Sen University, China.
Posted: June 15, 2019
Related story: Climate Change to Make Hot Droughts Hotter in the U.S. Southern Plains
Droughts and heatwaves often go hand-in-hand, but how a warming climate might affect their inter-relationship remains uncertain. NOAA and CIRES researchers from the ESRL Physical Sciences Laboratory are co-authors of a new study recently published in the Journal of Climate, which evaluates how, and by how much, human-caused climate change affects summertime hot drought events over the contiguous United States. The researchers conduct climate model simulations which demonstrate an intensification of heat waves during drought.
The study finds that anthropogenic warming leads to enhanced soil moisture–temperature coupling in semi-arid areas of the United States, especially the Southern Plains and Southwest U.S. The resulting greater feedback of the land surface on air temperatures acts to intensify heat waves during droughts. This warming is beyond the increase in heatwave intensities occurring simply from an overall warming trend accompanying climate change. Their results reveal a further temperature increase of comparable magnitude arising during severe droughts due to increased soil moisture feedbacks when soils are dry. This strengthened coupling accounts for a substantial fraction of the overall rising temperatures related to the long-term climate change in their model experiments, highlighting the importance of changes in land–atmosphere feedback in a warmer climate.
This study takes a step toward increasing knowledge on drought–heat wave interactions in a warming world, presenting evidence that such events may become especially severe in semi-arid regions, both in terms of their frequency and intensity. The researchers expect that these preliminary findings will be important to facilitate better communication with risk managers who are seeking to better understand how climate change exposes vulnerabilities of human health, water supply, and agricultural productivity, all susceptible to compound drought heat waves.
The authors of Physical understanding of human-induced changes in U.S. hot droughts using equilibrium climate simulation are: Linyin Cheng of the University of Arkansas, Martin Hoerling and Jon Eischeid of the ESRL Physical Sciences Laboratory, and Zhiyong Liu of Sun Yat-Sen University, China.
Posted: June 15, 2019
Related story: Climate Change to Make Hot Droughts Hotter in the U.S. Southern Plains