Details:

Journal Title:
Climate Dynamics
Personal Author:
Zhou, Xiaoye ; Liu, Fei ; Wang, Bin ; Xiang, Baoqiang ; Xing, Chen ; ... More +
Zhou, Xiaoye ; Liu, Fei ; Wang, Bin ; Xiang, Baoqiang ; Xing, Chen ; Wang, Hui Less -
NOAA Program & Office:
OAR (Oceanic and Atmospheric Research)
Description:
The East Asian summer monsoon (EASM) shows notable change during the summer after El Niño peak. This “delayed” response, however, is variable and difficult to predict. Here, we revisit this issue by separating El Niño decays into early transition and late transition. In the summer after an early transition, the central-to-eastern Pacific evolves into a La Niña condition, with positive rainfall anomaly occurring over most parts of eastern China. In contrast, in the summer after a late transition, the central-to-eastern Pacific sea surface temperature (SST) anomaly remains neutral or slightly above normal; correspondingly, the East Asian rainfall anomaly shows a tripolar structure with positive anomaly over the Yangtze-Huaihe River valley and negative anomalies over northern and southern China. These different rainfall responses are mainly related to different locations of the anomalous anticyclone (AAC) over the western North Pacific (WNP): it is centered at (165°E, 25°N) for late-transition El Niños, but at (135°E, 16°N) for early-transition El Niños. During the late transition, the AAC–SST feedback, identified by the dipole SST mode consisting of WNP cooling and northern Indian Ocean (NIO) warming, mainly works to support the WNP AAC. During the early transition, the AAC–SST feedback is weak and mainly attributed to NIO warming. The strong easterly anomaly over the western equatorial Pacific, which is tied to the central-to-eastern equatorial Pacific cooling and dipole precipitation pattern from western equatorial Pacific to the Maritime Continent, occurs to support the AAC and pulls it equatorward. These distinct responses exist in the last century, and the CMIP5 models can reproduce these distinct responses well except that the models underestimate the AAC–SST feedback for late-transition El Niños. The findings in this study help predict the EASM rainfall in post-El Niño years, but the key is the accurate prediction of the timing of decay.
Keywords:
[+]
Atmospheric Science
Source:
Climate Dynamics, 53(3-4), 1497-1515
DOI:
https://doi.org/10.1007/s00382-019-04684-6
ISSN:
0930-7575;1432-0894;
Format:
PDF
Publisher:
Springer Science and Business Media LLC
Document Type:
Journal Article
Funding:
Grant no. NA13OAR4310167
Rights Information:
Other
Compliance:
Library
Main Document Checksum:
[+]
urn:sha256:25dff708a311addf5de99eb99a73ad9954e8cd76f5abf51f294e9bcd33fb815c
Download URL:
https://repository.library.noaa.gov/view/noaa/60542/noaa_60542_DS1.pdf
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