The general features of the seasonal surface heat budget in the tropical western Pacific Ocean

20° S–20°N

western boundary −160°E

were documented by Qu (1995) using a high-resolution general circulation model (GCM

Semtner & Chervin

1992) and existing observations. Close inspection of the smaller areas

with the whole region further partitioned into six parts

showed different mechanisms balance the seasonal surface heat budget in different parts of the region. The results of study on five subregions are detailed in this article. In the equatorial (3°S–3°N) and North Equatorial Countercurrent (3°N–9°N) region

the surface heat flux does not change significantly throughout the year

so the surface heat content is determined largely by vertical motion near the equator and roughly half due to horizontal and half due to vertical circulation in the region of the North Equatorial Countercurrent (NECC). In the other subrigions (9°N–20°N

20°S–11°S and 11°S–3°S)

however

in addition to ocean dynamics

surface heat flux can also play a major role in the seasonal variation of sea surface temperature (SST). The remotely forced baroclinic waves and their effect on the surface heat storage in the model are also investigated. Comparison with observations indicates that the model wave activities are reasonably realistic.