ANTHROPOGENIC CONTRIBUTIONS TO THE INTENSITY OF THE 2017 UNITED STATES NORTHERN GREAT PLAINS DROUGHT

摘要

Drought conditions developed rapidly during the spring and summer of 2017 over the northern Great Plains states of South Dakota, North Dakota, and Montana (Fig. la). On 2 May 2017, the U.S. Drought Monitor (USDM) reported no drought, with only two small areas of abnormal dryness in the central part of the region (Fig. lb). By 1 August 2017, the USDM depicted widespread drought over all of eastern Montana and the Dakotas, highlighted by areas of extreme and exceptional drought (Fig. lc). Deemed a "billion dollar disaster,"1 this drought sparked widespread wildfires 2 and compromised water resources, which led to the destruction of property, livestock sell-offs, and reduced agricultural production.3 While this region is no stranger to drought (e.g., Woodhouse and Overpeck 1998),the last comparable event occurred as far back as 1987-89 [described in Riebsame et al. (1991)].4 Here, we investigate anthropogenic contributions to the intensity of this drought during May-July 2017 using climate model simulations.