Smaller Scale Disturbance in the Temperature Field around a Decaying Typhoon with Special Emphasis on the Severe Precipitation

[摘要] On July 9, 1967, severe precipitation took place along the western part of the Japan Islands with the passage of a decaying small scale typhoon. A remarkable disturbance was observed on the thermal structure in the lower troposphere. The amplitude of temperature deviation amounts to more than 2°C, whereas the wave length was as small as 1000km. Another noticeable feature is that the moist adiabatic instability was limited to the lowermost shallow layer over precipitation area and the deep layer above it was unexpectedly stable, suggesting the effect of prevailing convective upward transfer of thermal energy.The large amount of precipitation was supplied by the south-westerly current in a form of moist tongue and by the north-westerly compensating back current as well. The rainfall amount estimated from moisture budget basing on synoptic scale aerological observations was only about 1/3 of the observed rainfall amount, and it is suggested that the effect of mesoscale convergence should be taken into account.

[学科分类] 大气科学