Ocean and land forcing of the record-breaking Dust Bowl heat waves across central United States

The severe drought of the 1930s Dust Bowl decade coincided with record-breaking summer heatwaves that contributed to the socio-economic and ecological disaster over North America’s Great Plains. It remains unresolved to what extent these exceptional heatwaves, hotter than in historically forced coup...

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Bibliographic Details
Published in:Nature Communications
Main Authors: Cowan, T, Hegerl, G, Schurer, A, Tett, S, Vautard, R, Yiou, P, Jezequel, A, Otto, FE, Harrington, L, Ng, B
Format: Article in Journal/Newspaper
Language:English
Published: Springer Nature 2020
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Online Access:https://doi.org/10.1038/s41467-020-16676-w
https://ora.ox.ac.uk/objects/uuid:2d6599b9-448d-4069-84f9-f8e145e60ef5
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Summary:The severe drought of the 1930s Dust Bowl decade coincided with record-breaking summer heatwaves that contributed to the socio-economic and ecological disaster over North America’s Great Plains. It remains unresolved to what extent these exceptional heatwaves, hotter than in historically forced coupled climate model simulations, were forced by sea surface temperatures (SSTs) and exacerbated through human-induced deterioration of land cover. Here we show, using an atmospheric-only model, that anomalously warm North Atlantic SSTs enhance heatwave activity through an association with drier spring conditions resulting from weaker moisture transport. Model devegetation simulations, that represent the wide-spread exposure of bare soil in the 1930s, suggest human activity fueled stronger and more frequent heatwaves through greater evaporative drying in the warmer months. This study highlights the potential for the amplification of naturally occurring extreme events like droughts by vegetation feedbacks to create more extreme heatwaves in a warmer world.