Daily Variation of the Atmospheric Mass and Moisture Budget over the Tropical Western Pacific

[摘要] Periodic variations of divergence and vertical motion and the daily march of the atmospheric moisture budget are evaluated based on special upper-air and surface observation programs conducted over the Western Tropical Pacific in April-July 1956 and 1958. Daily variations of divergence and vertical motion are in their timing broadly consistent with the tidal pressure and wind oscillations. For the daily average, estimates of large-scale atmospheric water vapor flux convergence, precipitation, and evaporation are 6.5, 10.0, and 2.8 mm H2O day-1, respectively. The vector departure from the daily mean of the vertically integrated moisture flux shows a periodic clockwise turning in the course of the day, which is linked with the mechanism of the tidal pressure and wind variation. Budget terms with the largest daily range are, in order, change in precipitable water, water vapor flux convergence, and precipitation rate.

[学科分类] 大气科学