Increased drought severity tracks warming in the United States’ largest river basin

Authors

Justin T. Martin, US Geological Survey, Bozeman, MTFollow
Gregory T. Pederson, US Geological Survey, Bozeman, MT
Connie A. Woodhouse, University of Arizona
Edward R. Cook, Lamont-Doherty Earth Observatory, Palisades, NY
Gregory J. McCabe, US Geological Survey, Denver, CO
Kevin J. Anchukaitis, University of Arizona
Erika K. Wise, University of North Carolina at Chapel Hill
Patrick J. Erger, US Bureau of Reclamation, Billings, MT
Larry Dolan, Montana Department of Natural Resources and Conservation
Marketa McGuire, US Bureau of Reclamation, Denver, CO
Subhrendu Gangopadhyay, US Bureau of Reclamation, Denver, CO
Katherine J. Chase, US Geological Survey, Helena, MT
Jeremy S. Litell, US Geological Survey, Anchorage, AK
Stephen T. Gray, US Geological Survey, Anchorage, AK
Scott St. George, University of Minnesota - Twin Cities
Jonathan M. Friedman, US Geological Survey, Ft. Collins, CO
David J. Sauchyn, University of Regina
Jeannine-Marie St-Jacques, Concordia University, Montreal, QC
John King, Lone Pine Research, Bozeman, MT

ORCID IDs

Justin T. Martin https://orcid.org/0000-0002-3523-6596

Gregory T. Pederson https://orcid.org/0000-0002-6014-1425

Gregory J. McCabe https://orcid.org/0000-0002-9258-2997

Erika K. Wise https://orcid.org/0000-0002-1712-7476

Marketa McGuire https://orcid.org/0000-0001-8562-3394

Katherine J. Chase https://orcid.org/0000-0002-5796-4148

Jeremy S. Littell https://orcid.org/0000-0002-5302-8280

Stephen T. Gray https://orcid.org/0000-0002-5302-8280

Document Type

Article

Date of this Version

4-26-2020

Citation

PNAS, May 26, 2020, vol. 117, no. 21, pp 11328–11336

doi:10.1073/pnas.1916208117

Comments

U.S. government work

Abstract

Across the Upper Missouri River Basin, the recent drought of 2000 to 2010, known as the “turn-of-the-century drought,” was likely more severe than any in the instrumental record including the Dust Bowl drought. However, until now, adequate proxy records needed to better understand this event with regard to long-term variability have been lacking. Here we examine 1,200 y of streamflow from a network of 17 new tree-ring–based reconstructions for gages across the upper Missouri basin and an independent reconstruction of warm-season regional temperature in order to place the recent drought in a long-term climate context. We find that temperature has increasingly influenced the severity of drought events by decreasing runoff efficiency in the basin since the late 20th century (1980s) onward. The occurrence of extreme heat, higher evapotranspiration, and associated low-flow conditions across the basin has increased substantially over the 20th and 21st centuries, and recent warming aligns with increasing drought severities that rival or exceed any estimated over the last 12 centuries. Future warming is anticipated to cause increasingly severe droughts by enhancing water deficits that could prove challenging for water management.

Includes supplemental file