Influence of the Indian Ocean Dipole on the Indian Ocean Meridional Heat Transport

Abstract

Influence of the Indian Ocean Dipole (IOD) on the Indian Ocean Meridional Heat Transport (MHT) is studied using 60-yr SODA data. Results show that there is anomalous heat transport from the equatorial region to higher latitudes in both hemispheres during IOD events, and the anomalous poleward MHT occurs mainly in the western Indian Ocean. IOD has strong influence on the MHT during late summer and fall, which is consistent with the seasonal phase-locking characteristics of IOD itself. The MHT anomaly caused by anomalous meridional velocity, which is induced by wind, is the major contributor of the total MHT anomalies. EOF analysis shows that the IOD is a key factor for interannual variability of the MHT in the Indian Ocean. These findings are very useful for understanding the Indian Ocean heat balance and climatic implications of IOD.