Anomalous Walker circulations associated with two flavors of the Indian Ocean Dipole

Abstract The Walker circulation is the key component of the atmospheric zonal circulation in the tropics. In this study, it is shown that anomalous Walker circulations associated with two types of the Indian Ocean Dipole (IOD) are remarkably different. During a positive canonical IOD with negative (...

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Main Authors: Tomoki Tozuka, Satoru Endo, Toshio Yamagata
Format: Article
Language:English
Published: Wiley 2016-05-01
Series:Geophysical Research Letters
Subjects:
Online Access:https://doi.org/10.1002/2016GL068639
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author Tomoki Tozuka
Satoru Endo
Toshio Yamagata
author_facet Tomoki Tozuka
Satoru Endo
Toshio Yamagata
author_sort Tomoki Tozuka
collection DOAJ
description Abstract The Walker circulation is the key component of the atmospheric zonal circulation in the tropics. In this study, it is shown that anomalous Walker circulations associated with two types of the Indian Ocean Dipole (IOD) are remarkably different. During a positive canonical IOD with negative (positive) sea surface temperature (SST) anomalies in the eastern (central to western) tropical Indian Ocean, a single‐cell anomalous Walker circulation forms over the Indian Ocean. On the other hand, a double‐cell anomalous Walker circulation with a rising branch in the central Indian Ocean is formed during a positive IOD Modoki, which is associated with positive (negative) SST anomalies over the central (eastern and western) tropical Indian Ocean. The above anomalous Walker circulations are found to develop as part of positive ocean‐atmosphere feedback. Furthermore, the above difference in the anomalous Walker circulation may affect the biennial tendency of the IOD.
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publishDate 2016-05-01
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series Geophysical Research Letters
spelling doaj-art-cd803acdc9de4afaa9d7a898efcd349a2025-08-20T03:49:37ZengWileyGeophysical Research Letters0094-82761944-80072016-05-0143105378538410.1002/2016GL068639Anomalous Walker circulations associated with two flavors of the Indian Ocean DipoleTomoki Tozuka0Satoru Endo1Toshio Yamagata2Department of Earth and Planetary Science, Graduate School of Science University of Tokyo Tokyo JapanDepartment of Earth and Planetary Science, Graduate School of Science University of Tokyo Tokyo JapanApplication Laboratory JAMSTEC Yokohama JapanAbstract The Walker circulation is the key component of the atmospheric zonal circulation in the tropics. In this study, it is shown that anomalous Walker circulations associated with two types of the Indian Ocean Dipole (IOD) are remarkably different. During a positive canonical IOD with negative (positive) sea surface temperature (SST) anomalies in the eastern (central to western) tropical Indian Ocean, a single‐cell anomalous Walker circulation forms over the Indian Ocean. On the other hand, a double‐cell anomalous Walker circulation with a rising branch in the central Indian Ocean is formed during a positive IOD Modoki, which is associated with positive (negative) SST anomalies over the central (eastern and western) tropical Indian Ocean. The above anomalous Walker circulations are found to develop as part of positive ocean‐atmosphere feedback. Furthermore, the above difference in the anomalous Walker circulation may affect the biennial tendency of the IOD.https://doi.org/10.1002/2016GL068639Indian Ocean DipoleWalker circulationtropical Indian Ocean
spellingShingle Tomoki Tozuka
Satoru Endo
Toshio Yamagata
Anomalous Walker circulations associated with two flavors of the Indian Ocean Dipole
Geophysical Research Letters
Indian Ocean Dipole
Walker circulation
tropical Indian Ocean
title Anomalous Walker circulations associated with two flavors of the Indian Ocean Dipole
title_full Anomalous Walker circulations associated with two flavors of the Indian Ocean Dipole
title_fullStr Anomalous Walker circulations associated with two flavors of the Indian Ocean Dipole
title_full_unstemmed Anomalous Walker circulations associated with two flavors of the Indian Ocean Dipole
title_short Anomalous Walker circulations associated with two flavors of the Indian Ocean Dipole
title_sort anomalous walker circulations associated with two flavors of the indian ocean dipole
topic Indian Ocean Dipole
Walker circulation
tropical Indian Ocean
url https://doi.org/10.1002/2016GL068639
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AT satoruendo anomalouswalkercirculationsassociatedwithtwoflavorsoftheindianoceandipole
AT toshioyamagata anomalouswalkercirculationsassociatedwithtwoflavorsoftheindianoceandipole