Spring land temperature anomalies in northwestern US and the summer drought over Southern Plains and adjacent areas

Xue, Yongkang; Oaida, Catalina M; Diallo, Ismaila; Neelin, J David; Li, Suosuo; Fernando De Sales; Gu, Yu; Robinson, David A; Vasic, Ratko; Yi, Lan

Env. Res. Lett., 11, 44,018-44029(12), doi:10.1088/1748-9326/11/4/044018. Journal paper

Abstract. Recurrent drought and associated heatwave episodes are important features of the U.S. climate. Many studies have examined the connection between ocean surface temperature changes and conterminous U.S. droughts. However, remote effects of large-scale land surface temperature variability, over shorter but still considerable distances, on U.S. regional droughts have been largely ignored. The present study combines two types of evidence: climate observations and model simulations, to address these effects. Our analysis of observational data shows that springtime land temperature in the U.S. Northwest is significantly correlated with summer rainfall and heat changes in the U.S. Southern Plains and its adjacent areas. Our model simulations of the 2011 Southern Plains drought using a general circulation model and a regional climate model confirm the observed relationship between land temperature anomaly and drought and suggest that the long-distance effect of land temperature changes in the U.S. Northwest on Southern Plains droughts is probably as large as the more familiar effects of ocean surface temperatures and atmospheric internal variability. We conclude that the cool 2011 springtime climate conditions in the U.S. Northwest increased the probability of summer drought and abnormal heat in the Southern Plains. The present study suggests a strong potential for more skillful intra-seasonal predictions of U.S. Southern Plains droughts when such facts as ones presented here are considered.

Citation:
Xue, Y., C. M. Oaida, I. Diallo, J. D. Neelin, S. Li, Fi. De Sales; Y. Gu, D. A. Robinson, R. Vasic, and L. Yi, 2016: Spring land temperature anomalies in northwestern US and the summer drought over Southern Plains and adjacent areas. Env. Res. Lett., 11, 44,018-44029(12), doi:10.1088/1748-9326/11/4/044018.


Acknowledgments. This work was supported by National Science Foundation grants AGS-1346813, AGS-1115506 and AGS-1540518 (JDN).  The model runs were conducted at the National Center for Atmospheric Research Bluefire Supercomputer and the Texas Advanced Computer Center Stampede Supercomputer.