Structure of the intertropical convergence zone over the GATE area

The meridional structure of wind, temperature, and moisture of the intertropical convergence zone (ITCZ) over the GATE observational area is presented. The structure is obtained by compositing rawinsonde observations with respect to the surface wind confluence line. The most important characteristic of the structure is the absence of any significant temperature maximum at any level in the central core of the ITCZ. This absence indicates that condensational heating and, hence, CISK is only a secondary mechanism in the development and maintenance of the GATE ITCZ. The primary mechanism may be either barotropic instability or pressure energy flux from temperate latitudes.