Some Features of Synoptic–Scale Waves Based on a Compositing Analysis of GATE Data

Abstract

A compositing technique has been used to analyze the wind field of easterly waves in the GATE region of western Africa and the eastern Atlantic. The compositing analysis is similar to the method of Reed and Recker (1971), but this study includes variations of the waves as a function of latitude in addition to variations as a function of east?west wavelength and height. A wave composited for the summer of 1974 has been isolated from the mean flow and analyzed on constant pressure maps. From these analyses, kinematic vertical motion has been computed in the lower and middle troposphere. The results show that the pattern of vertical motion calculated from the compositing agrees quite well with satellite cloud patterns.