Comparison of Surface Fluxes in the Warm Pools of the Eastern Indian and the Western Pacific Oceans

he principal scientific objective of TOGA COARE (1991--1992) was to determine the heat balance of the upper layers of the western Pacific Ocean (WPO) which had hitherto been unresolved. The Joint Air-Sea Monsoon Interaction Experiment (JASMINE) held in the summer of 1999 was a pilot study with similar aims to TOGA COARE but for the monsoon regions of the eastern Indian Ocean (EIO). Both the WPO and the EIO are critical areas for ocean-atmosphere interaction that have important influences on climate variability.

A comparison is made between the surface fluxes on diurnal, synoptic and intraseasonal time scales. In general, it is found that the fluxes in the EIO show considerably more variability than the fluxes in the WPO. Although the net flux into the ocean average over a long period of time is much the same in the two warm pools, the temporal variability is very different. Special attention is given to the differences in the fluxes during active and inactive (break) periods of the monsoon. Only during one period of the TOGA COARE (November 1991) is there similar strong heating of the ocean as found during break periods of the monsoon.

Finally, comparisons are made between the fluxes found in TOGA COARE with the COADS data set, and those generated in NCEP/NCAR and ECMWF reanalyses. Monthly averaged COADS data cannot resolve the intraseasonal variability of the flux variability. However, numerical estimates show far less intraseasonal variability of fluxes probably due , in part, to the use of smoothed sea-surface temperature products.