METEOROLOGICAL SATELLITE INFRARED VIEWS OF CLOUD GROWTH ASSOCIATED WITH THE DEVELOPMENT OF SECONDARY CYCLONES

Abstract

During March 1962, the cloud changes associated with the predevelopment and development-periods of two secondary cyclones in the North Pacific Ocean were viewed on at least two successive days by the 8?12µ ?window? channel of the TIROS IV meteorological satellite. Both secondary cyclones developed at the base of the occlusion. For the two cases, when the secondary circulations were first noticeable on the surface chart, the equivalent blackbody temperatures (TBB) as measured by the radiometer averaged 15°K colder than the day before in the northeast quadrant relative to the base of the occulusion. The average TBB was taken over an area of approximately 300,000 mi2. For two other cases, an average warming of 4°K occured from day to day over the same area relative to the base of the occlusion when no significant secondary development occurred and when the primary occluded cyclone was slowly weakening. These results suggest that, with the assistance of meteorological satellite radiation data, considerable cloud growth is noticeable prior to the generation of a secondary cyclone at the base of the occlusion.