Sea surface temperature over Indian Ocean and its influence on Indian Monsoon rainfall

This study examines the relationship between sea surface temperature (SST) and monsoon wind pattern on seasonal and interannual time scales using the Ocean General Circulation Model (OGCM), hereafter referred to as Modular Ocean Model version 3.0 (MOM 3.0), for the period 1992-2015 over the Indian Ocean (IO) region (45 degrees E-100 degrees E, 10 degrees S-25 degrees N), including the Arabian Sea (AS) and Bay of Bengal (BoB). We have focused primarily on significant features of SST that emerge from the model output, such as its spatial and temporal variability using EOF, SST climatology and anomalies, tendency of seasonal SST's and standard deviation, regression analysis between 850 mb wind and precipitation against the EOF, and finally, pattern correlation between Bay of Bengal (BoB), SST and Indian Summer Monsoon Rainfall (ISMR). Numerous analyses show that SST anomalies over IO provide vital information about the local Indian monsoon system, and warmer SST,increasing the strength of the monsoon component in India, according to numerous analyses. The cooling in the southeastern IO may be due to increased latent heat loss, which could suggest polarity reversal in the context of the Indian Ocean Dipole (IOD), which is thought to have a significant impact on Indian monsoon variability. The standard deviation of SST also provides a comprehensive picture of the Indian monsoon system and sheds light on SST variability in the northern Indian Ocean. The linear positive correlation between BoB, SST and ISMR in peninsular India and North Eastern India, indicates more than 55% positive correlation, with a confidence level of 95%.