Open AccessImportance of Ocean Dynamics for the Skewness of the Indian Ocean Dipole Mode
Author(s) -
Tomomichi Ogata,
ShangPing Xie,
Jing Lan,
XiaoTong Zheng
Publication year - 2013
Publication title -
journal of climate
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.315
H-Index - 287
eISSN - 1520-0442
pISSN - 0894-8755
DOI - 10.1175/jcli-d-11-00615.1
Subject(s) - thermocline , climatology , hindcast , sea surface temperature , skewness , ocean general circulation model , ocean dynamics , indian ocean dipole , geology , ocean current , subtropical indian ocean dipole , environmental science , predictability , oceanography , general circulation model , climate change , physics , statistics , mathematics , quantum mechanics
Interannual anomalies of sea surface temperature (SST), wind, and cloudiness in the southeastern tropical Indian Ocean (SE-TIO) show negative skewness. In this research, asymmetry between warm and cold episodes in the SE-TIO and the importance of ocean dynamics are investigated. A coupled model simulation and observations show an asymmetric relationship between SST and the thermocline depth in the SE-TIO where SST is more sensitive to an anomalous shoaling than to deepening of the thermocline. This asymmetric thermocline feedback on SST is a result of a deep mean thermocline. Sensitivity experiments with an ocean general circulation model (OGCM) show that a negative SST skewness arises in response to sinusoidal zonal wind variations that are symmetric between the westerly and easterly phases. Heat budget analysis with an OGCM hindcast also supports the importance of ocean dynamics for SST skewness off Sumatra and Java.