The Structure and Energetics of the East Atlantic Intertropical Convergence Zone

Abstract

Rawinsonde and satellite data from GATE are used to construct composite analyses of the Intertropical Convergence Zone (ITCZ) of the summertime eastern Atlantic. The latitude of the ITCZ varies substantially with time, and the data are analyzed relative to the latitude of maximum convection. Sensible heat, moisture and kinetic energy budgets are performed. Significant mean upward motion occurs over a band approximately 900 km wide. The ITCZ is centered in a broad surface low pressure trough with a weak upper-level warm core structure. It is found to be a direct circulation which generates an excess of kinetic energy, most of which is exported meridionally in the upper troposphere by transient eddy circulations.