Relationship between sea surface temperature and surface air temperature over Arabian Sea, Bay of Bengal and Indian Ocean

Abstract

Climatology and relationship of Sea Surface Temperature (SST) and Surface Air Temperature (SAT) over the Arabian Sea, Bay of Bengal and Indian Ocean north of 15 o S are examined on annual and seasonal time scales using the Voluntary Observing Ships data for a period of 40 years (1961-2000). Seasonally, spatial patterns of climatological SST indicate large northward spread of temperatures greater than 28 o C from winter to summer in the Arabian Sea and the Bay of Bengal. During monsoon season, there is appreciable cooling in the western half of the Arabian Sea while the entire Bay of Bengal still remains warm (>28 o C). The SST and SAT correlation coefficients are quite high over the Arabian Sea and the Indian Ocean as compared to the Bay of Bengal, providing a good justification for using SST as an indicator of SAT variability over these regions. Relationship between SST and SAT indicates same variance over the Arabian Sea and large parts of the north Indian Ocean. But variance ratios of SST and SAT over the Bay of Bengal are quite high for all seasons, indicating a less energetic atmosphere causing smaller SAT variance as compared to SST variance over the area. The striking feature of the mean SST and SAT difference field is the change from strong winter patterns to weak monsoon patterns for sensible heat exchange over the Arabian Sea and the Bay of Bengal.