RELATIONSHIPS BETWEEN HEAVY RAINFALL DISASTERS AND TAPERING CLOUDS

Abstract

It has been reported that the appearance of Tapering Cloud (TC) is one of the most disastrous cloud systems causing heavy rainfall and associated serious disasters. However, there are only a few reports that robustly analyzed the TC due to high frequency of TCs formed in the ocean. Therefore, paying attention to easily recognizable triangle shape of TCs seen in infrared satellite images, our study extracted TCs in the Japan islands and its surroundings for 11 years (Jun-Sep: 1999-2009) , and investigated significant relationships between TCs and heavy rainfall disasters. The results show that remarkably-disastrous events were closely related to the activity of TCs regardless of low frequency of TCs that caused heavy rainfall disasters in the Japan Islands. In these events, some TCs could be detected in advance before heavy rainfall disasters occurred. Therefore, it can be expected that the behavior of TCs is available as valuable information for detecting a precursor of heavy rainfall.