Characteristics of the ITCZ over the Eastern Pacific, 5–8 June 1979

Abstract

The thermal and moisture structures of the ITCZ over the Eastern Pacific-Central American region have been studied during a selected four-day period in June 1979 (FGGE). Composite structures were constructed by using soundings gathered from dropwindsondes, tropical wind observing ships, and land stations. The composited temperature structure shows that the ITCZ is cold-cored at middle levels and warm-cored at upper levels. At low levels, there is neither a distinct maximum or a minimum in the ITCZ; instead, there is a gradual decrease in temperature as one crosses the ITCZ from north to south. The moisture shows that the ITCZ, as expected, is characterized by a maximum moisture content. The maximum dew-point depression differences between the ITCZ and the environment are found at middle levels. These composites indicate that the ITCZ structure over the Eastern Pacific-Central American region on 5?8 June 1979 is similar to that of the easterly wave. This similarity in structure suggests a corresponding similarity in energetics.