Abstract
At first, the daily variation of pressure‐heights in the troposphere and low stratosphere is determined with observations from GATE. Resulting values are compared with those obtained in the Caribbean in the 1940's. One finds the semi‐diurnal cycle well maintained up to 500mb in both samples, as well as the transition to a single asymmetric wave in the high troposphere and low stratosphere. The amplitude is much reduced in GATE, suggesting that the temperature corrections applied in the Caribbean were too small. Nevertheless, the range of 60m at 100mb still corresponds to the mean latitudinal pressure‐height difference over 20° latitude across the GATE area in the Northern Hemisphere summer.
The 24‐ and 12‐hourly oscillations of the standard pressure surfaces have been determined by harmonic analysis up to 100mb, the highest level for which pressure‐height data were available. The results are given in Table 3 and they show more precisely than Fig. 1 the vertical distribution of the first and second harmonics and the transition from a daily pressure variation with two maxima and minima to one where only one predominant maximum and one predominant minimum appears each day.