3.1.2. SST
Distribution of SST in the SEAS and the GoM has some characteristic
behaviour (Supplementary Figure 2). The warmest SST in the study domain
exists during the Pre-Monsoon, which is the first solar heating period
in the region17,18. Following it, relatively cold
water appears along the southwest coast of India and the GoM by June,
and this cold SST situation prevails till October. It is also evident
that much cooler SST (25-26°C) prevails along the Southwest coast of
India compared to the GoM (~27°C) during the Southwest
Monsoon (May to September). Also, the cooler water patch persists for
longer duration in the southern tip of the southwest coast of India as
it lasts from May to October, probably a cause of extended periods of
upwelling there by local winds16. The upwelling
signatures appear first at the southern tip of Indian
subcontinent1 and later advances northward along with
the coastally trapped Kelvin wave19,20. Though the
cold water along the southwest coast of India disappears by October,
relatively cold water reappears in the GoM by November. It lasts up to
February (Northeast Monsoon), as a continuity of the cold water mass in
the Bay of Bengal, intruded through the Palk Bay21.