A Discussion on the Master-Servant Relation of Air-Sea Interaction over NINO3 Region and the Equatorial Eastern Indian Ocean

Which of the atmosphere and ocean plays the leading role is a problem of critical importance in the study of their interaction, and our concern is what difference is in the leading role played by the equatorial eastern Pacific and Indian ocean and what its seasonal variation is. The used data in this paper include i) 1951-94 global monthly SST at 1*1 resolution, compiled by British Meteorological Office and ii) NCEP/NCAR re-analysis data at 2.5*2.5 resolution for 1958-1997. Based on the lag correlation technique for seasonal difference in SST between the equatorial eastern Pacific and Indian Ocean, together with their possible intrinsic linkage examined, we come to the conclusions as follows:

Atmospheric effect on equatorial eastern Indian SST is dominant on a seasonal basis, leading to the fact that the SSTA is the result, rather than the cause, of atmospheric circulation anomaly. The master-servant relation in the sea-air interaction experiences radical change from fall/winter to spring/summer for the equatorial eastern Pacific; SST effect on the atmosphere dominates in autumn and winter in opposition to the case in spring and summer.

Noticeable lag correlation exists in SST between the equatorial eastern Pacific and Indian Ocean. The previous (fall/winter) Pacific SSTA is likely to be the leading cause of the simultaneous and subsequent SSTA over the equatorial eastern Indian ocean, with the equatorial E-W Walker circulation probably acting as the bridge.