Internal-Gravity-Wave-like Variations of Temperature, Humidity and Wind Observed in the Troposphere Downstream of Heavy Rainfall Area

Abstract

The upper-air data were examined for a few cases of heavy rainstorms over Japan, in expection of finding internal gravity waves generated over the storm areas. Among the cases, there was one case where variations of temperature, relative humidity and horizontal wind velocity in the troposphere showed features of internal gravity waves in the downstream of heavy rainfall (∼150mm/day) area. The horizontal and vertical wave lengths of the variations were ∼400km and ∼3km, respectively. The amplitudes of temperature, humidity and wind velocity variations were estimated as ∼2K, ∼20% and 4m/sec respectively. But, no wave-like variation was detected in geopotential height. The wave-like variations were not found from the observational data 12 hours later.