Structure of the Mid-Oceanic Intertropical Convergence Zone

Abstract

The synoptic scale structure of the ITCZ over mid-oceanic regions is deduced from observations over the Pacific and the Atlantic oceans. The temperature distribution indicates that the ITCZ is warm-cored in the lower troposphere and cold-cored in the middle troposphere. The moisture distribution is characterized by large moisture content throughout all levels in the central core; a region of low moisture content is found near the 700-mb level just outside of the central core. The wind is relatively unperturbed at the surface layers but significant perturbations are indicated in the middle troposphere. The physical processes which may be responsible for the observed structure are proposed. On the basis of these physical processes, the energetics of the ITCZ as a synoptic system is discussed.