气候变化领域集成服务门户(CCPortal): How MJO Teleconnections and ENSO Interference Impacts U.S. Precipitation

CCPortal

DOI	10.1175/JCLI-D-19-0448.1
	How MJO Teleconnections and ENSO Interference Impacts U.S. Precipitation
	Arcodia M.C.; Kirtman B.P.; Siqueira L.S.P.
发表日期	2020
ISSN	0894-8755
起始页码	4621
结束页码	4640
卷号	33 期号:11
英文摘要	A composite analysis reveals how the Madden-Julian oscillation (MJO) impacts North American rainfall through perturbations in both the upper-tropospheric flow and regional low-level moisture availability. Upper-level divergence associated with the MJO tropical convection drives a quasi-stationary Rossby wave response to the midlatitudes. This forces a midlatitude upper-level dipolar geopotential height anomaly that is accompanied by a westward retraction of the jet stream and reduced rainfall over the central-eastern North Pacific.Areverse effect is found as the MJO propagates eastward across the Maritime Continent. These large differences in the extratropical upper-level flow, combined with anomalies in the regional supply of water vapor, have a profound impact on southeastern U.S. rainfall. The low-frequency variability, including that associated with ENSO, can modify the seasonal background flow (e.g., El Ninõ and La Ninã basic states) affecting the distribution, strength, and propagation of the intraseasonal oscillation and the extratropical teleconnection patterns. The combined effects of the ENSO and the MJO signals result in both spatial and temporal patterns of interference and modulation of North American rainfall. The results from this study show that during a particular phase of an active MJO, the extratropical response can considerably enhance or mask the interannual ENSO signal in the United States, potentially resulting in anomalies of the opposite sign than that expected during a specific ENSO phase. Analyses of specific MJO events during an El Ninõ or La Ninã episode reveal significant contributions to extreme events via constructive and destructive interference of the MJO and ENSO signals. © 2020 American Meteorological Society. All rights reserved.
英文关键词	Mechanical waves; Oscillating flow; Rain; Tropical engineering; Destructive interference; Geopotential height anomalies; Intraseasonal oscillations; Low frequency variability; Madden-Julian oscillation; North american rainfalls; Spatial and temporal patterns; Teleconnection patterns; Climatology; atmospheric moisture; El Nino-Southern Oscillation; Madden-Julian oscillation; precipitation (climatology); rainfall; seasonal variation; teleconnection; Pacific Ocean; Pacific Ocean (North); United States
语种	英语
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/171274
作者单位	Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL, United States
推荐引用方式 GB/T 7714	Arcodia M.C.,Kirtman B.P.,Siqueira L.S.P.. How MJO Teleconnections and ENSO Interference Impacts U.S. Precipitation[J],2020,33(11).
APA	Arcodia M.C.,Kirtman B.P.,&Siqueira L.S.P..(2020).How MJO Teleconnections and ENSO Interference Impacts U.S. Precipitation.Journal of Climate,33(11).
MLA	Arcodia M.C.,et al."How MJO Teleconnections and ENSO Interference Impacts U.S. Precipitation".Journal of Climate 33.11(2020).