Energy Transfer and Tropical Cell Structure Over the Central Pacific

Abstract

Abstract The meridional circulation over the equatorial central Pacific Ocean in April 1967 was found to consist of a shallow northern Hadley cell, an extensive equatorial cell centered south of the equator with maximum subsidence over the equator, and a strong southern Hadley cell. Part of the high-level outflow of the southern Hadley cell subsides across the equator and decreases the activity of the northern convergence zone. The divergence of the equatorial easterlies and the resulting subsidence is increased by a low value of the shearing stress which was observed over the cool upwelling equatorial waters. Transfer of energy by radiation, turbulence, precipitation and advection is determined from observations and calculation. Energy budgets are constructed for three regions between 13N and 13S to obtain as a residual the transport of energy by cumulus and cumulonimbus convection. The budget shows that the mid-tropospheric layer of the low energy is maintained by the efficient vertical transfer of ener...