日本の暖候期における停滞性降水システムの特徴とその環境条件

Abstract

This study investigates the characteristics of the development of quasi-stationary mesoscale convective systems (QSMCSs) over the Japanese islands during warm season. For this purpose, we use the operational radar data of Japan Meteorological Agency (JMA) from May to October during 2005 and 2012. In addition, the upper-air sounding data ob- tained at the Japanese sites are used to examine the environmental conditions before the development of QSMCSs. In order to determine the QSMCSs from radar data, we use Algorithm for the Identification and Tracking Convective Cells (AITCC). It is found that we can classify the QSMCSs into three regions based on the frequency of the development of QSMCSs and the amount of precipitation. The common features of the environmental conditions for the development of QSMCSs throughout the warm season are characterized as having higher precipitable water (PW) and larger low-level wind speed differences com- pared to the environments for no-rain cases. It is suggested that the development of the QSMCSs is controlled by PW and the vertical distribution of moisture.