How the Great Plains Dust Bowl drought spread heat extremes around the Northern Hemisphere
The Dust Bowl Drought of the 1930s (1932-39) occurred over the Great Plains of North America and was one of the worst natural disasters of the 20th century. This drought was associated not only with heat extremes over the U.S., but also with record-setting heat over other areas of the Northern Hemisphere. We seek to identify the connection between record setting heat over the US associated with the Great Plains Dust Bowl drought, and extraordinary heat extremes during the 1930s in areas of the Northern Hemisphere far from North America.
A climate model sensitivity experiment run with a version of the atmospheric model in E3SMv1 is used to identify a new mechanism involving a warm season circumglobal wave-5 atmospheric teleconnection pattern that spread heat extremes over widely separated areas of the Northern Hemisphere. We show that this pattern was forced by intense heating over the hot and dry Great Plains themselves. It arose in a unique way from human influence — not by burning fossil fuels, but from plowing up the middle third of the U.S. in an ill-advised effort to plant dryland wheat.
It has only been in the 21st century that human populations in these regions of the Northern Hemisphere have experienced heat extremes comparable to the 1930s. This demonstrates that humans influenced Northern Hemisphere temperature and heat extremes through disastrous and unprecedented regional land use practices over the Great Plains, and points to the possibility that future intense regional droughts could affect heat extremes on hemispheric scales.