R. R. Rao

Observed mini-cold pool off the southern tip of India and its intrusion into the south central Bay of Bengal during summer monsoon season

The observed mini-cold pool (MCP) off the southern tip of India (STI) and its intrusion into the south central Bay of Bengal (BoB) during the summer monsoon season is examined utilizing the available satellite and in situ measurements. The mechanisms that govern the occurrence of this MCP through surface wind field and its curl, net surface heat flux and divergence in the near-surface circulation (Ekman + geostrophic) are examined. The observed MCP primarily appears to be driven by the upwelling caused by the divergence in the near-surface circulation. The upwelling results in both shoaling of thermocline and enhanced blooming of chlorophyll-a. With the progress of the season the sea surface temperature (SST) cooling associated with MCP intrudes into the south central BoB by the Summer Monsoon Current (SMC).

Reduced Near-Surface Thermal Inversions in 2005–06 in the Southeastern Arabian Sea (Lakshadweep Sea)*

Abstract Repeat XBT transects made at near-fortnightly intervals in the Lakshadweep Sea (southeastern Arabian Sea) and ocean data assimilation products are examined to describe the year-to-year variability in the observed near-surface thermal inversions during the winter seasons of 2002–06. Despite the existence of a large low-salinity water intrusion into the Lakshadweep Sea, there was an unusually lower number of near-surface thermal inversions during the winter 2005/06 compared to the other winters. The possible causative mechanisms are examined. During the summer monsoon of 2005 and the following winter season, unusually heavy rainfall occurred over the southwestern Bay of Bengal and the Lakshadweep Sea compared to other years in the study. Furthermore, during the winter of 2005, both the East India Coastal Current and the Winter Monsoon Current were stronger compared to the other years, transporting larger quantities of low salinity waters from the Bay of Bengal into the Lakshadweep Sea where a relat...