Publication Date:
2021-05-19
Description:
This study explores the impacts of the Indian summer monsoon (ISM) on the El
Niño-Southern Oscillation (ENSO) evolution by utilizing two coupled general circulation
model simulations. The first simulation uses the Center for Ocean-Land-Atmosphere
Studies (COLA) anomaly coupled model and the second simulation employs a new
coupling strategy, interactive ensembles, that is designed to increase the signal to noise
ratio. The effects of monsoon variability related and unrelated to ENSO are separated
through composites in terms of both Niño-3.4 sea surface temperature (SST) and Indian
summer monsoon rainfall (IMR) anomalies. It is found that ENSO-related monsoon
variability has significant impacts on warm events. In the interactive ensemble
simulation, a weak (strong) monsoon enhances (weakens) an ongoing warm event. The
monsoon impacts are manifested in the surface zonal wind stress anomalies in the
western-central equatorial Pacific. In the anomaly coupled simulation, the monsoon-
ENSO relationship is difficult to detect. The ongoing cold events are only weakly
affected by monsoon variability. Monsoon variability that is unrelated to ENSO also
induces noticeable SST anomalies in the equatorial central Pacific in the following
winter. In the interactive ensemble model, a weak (strong) monsoon induces noticeable
warm (cold) SST anomalies.
Description:
Unpublished
Keywords:
Monsoons
;
Sea surface temperature
Repository Name:
AquaDocs
Type:
Working Paper
,
Non-Refereed
Format:
2966268 bytes
Format:
application/pdf
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