Mean net surface heating of the Pacific ocean shows areas of high heat gain in the eastern tropical Pacific and heat loss in the western mid-latitudes. For steady-state conditions, westward and poleward transport of heat is implied. Mean geostrophic heat fluxes through the sides of a large western/central Pacific box bounded by high resolution (HR) XBT transects, are presented. The sections enclose the climatologically important western Pacific warm pool. Mean pathways of heat transfer through the enclosed volume are investigated. Water mass properties of currents transporting heat through the region are seen to be modified in transit.
Net transport convergences within the western Pacific volume show an upper ocean circulation cell with relatively dense 
~ 22 - 26 water entering the volume and lighter < 22 water leaving. Suprisingly, surface heating is not required to convert dense water to a more bouyant range. In fact, there is a net weak < .1 ± .3 PW convergence of heat by ocean currents which implies heat loss to the atmosphere. Surface freshwater gain allows warm, salty water to enter in the same density range as cool, fresh water leaving the volume.
For steady state conditions, < .1 ± .3 PW oceanic heat convergence is balanced by negligible heat loss to the atmosphere. ECMWF operational model output predicted a net heat loss between 1991-1994 balancing the oceanic measurement within uncertainty. However surface heat flux climatologies predict a net heat gain between 0.4 - 0.6 PW. Part of this discrepancy may be due to the anomalous meteorological conditions of the HR XBT experiment (1987-1995). Oceanic freshwater divergence of 0.70 ± .08 Sv, mainly due to salty inflow in the South Equatorial Current and freshwater outflow elsewhere, fell in the range of climatological predictions from freshwater gain through the surface (0.3 - 1.1 Sv).
To Abstract List
To Pacific Workshop
To WOCE Home Page