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DOI	10.1175/JCLI-D-20-0428.1
	On the development and demise of the fall 2019 southeast U.S. Flash drought: Links to an extreme positive IOD
	Schubert S.D.; Chang Y.; Deangelis A.M.; Wang H.; Koster R.D.
发表日期	2021
ISSN	08948755
起始页码	1701
结束页码	1723
卷号	34 期号:5
英文摘要	Much of the southeast United States experienced record dry conditions during September of 2019, with the area in abnormally dry to exceptional drought conditions growing from 25% at the beginning of the month to 80% by the end of the month. The drought ended just as abruptly due to above-normal rain that fell during the second half of October. In this study we employed MERRA-2 and the GEOS-5 AGCM to diagnose the underlying causes of the drought's onset, maintenance, and demise. The basic approach involves performing a series of AGCM simulations in which the model is constrained to remain close to MERRA-2 over prespecified areas that are external to the drought region. The start of the drought appears to have been forced by anomalous heating in the central/western tropical Pacific that resulted in low-level anticyclonic flow and a tendency for descending motion over much of the Southeast. An anomalous ridge associated with a Rossby wave train (emanating from the Indian Ocean region) is found to be the main source of the most intense temperature and precipitation anomalies that develop over the Southeast during the last week of September. A second Rossby wave train (emanating from the same region) is responsible for the substantial rain that fell during the second half of October to end the drought. The links to the Indian Ocean dipole (with record positive values) as well as a waning El Niño allow some speculation as to the likelihood of similar events occurring in the future. © 2021 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).
英文关键词	Drought; Extreme events; Rossby waves; Teleconnections
语种	英语
scopus关键词	Mechanical waves; Ocean currents; Rain; Anomalous heating; Anticyclonic flow; Drought conditions; Indian Ocean dipole; Indian ocean regions; Precipitation anomalies; Southeast United States; Underlying cause; Drought; air-sea interaction; anticyclone; atmospheric general circulation model; climate modeling; computer simulation; drought; El Nino; extreme event; Indian Ocean Dipole; numerical model; precipitation intensity; Rossby wave; teleconnection; temperature anomaly; Pacific Ocean; Pacific Ocean (Tropical); United States
来源期刊	Journal of Climate
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/178708
作者单位	Global Modeling and Assimilation Office, NASA, GSFC, Greenbelt, MD, United States; Science Systems and Applications, Inc., Lanham, MD, United States; Morgan State University, Baltimore, MD, United States; Climate Prediction Center, NCEP, NWS, NOAA, College Park, MD, United States
推荐引用方式 GB/T 7714	Schubert S.D.,Chang Y.,Deangelis A.M.,et al. On the development and demise of the fall 2019 southeast U.S. Flash drought: Links to an extreme positive IOD[J],2021,34(5).
APA	Schubert S.D.,Chang Y.,Deangelis A.M.,Wang H.,&Koster R.D..(2021).On the development and demise of the fall 2019 southeast U.S. Flash drought: Links to an extreme positive IOD.Journal of Climate,34(5).
MLA	Schubert S.D.,et al."On the development and demise of the fall 2019 southeast U.S. Flash drought: Links to an extreme positive IOD".Journal of Climate 34.5(2021).