メカニズム解明に向けた線状対流系過去事例群の統合的物理解析

Abstract

The purpose of our research is to investigate the environmental conditions for the occurrence and development of line-shaped convective systems associated with stagnant Baiu front by comprehensively analyzing past events and considering spatio-temporal scale. As a result, type-A, which is large scale, long duration, and occurs near convergence of Baiu front, occurs due to large convergence of the front, so the environmental condition of type-A is not necessarily idealized. In contrast, type-B, which is small scale, short duration, and occurs far from Baiu front, occurs at more limited and idealized environment than type-A. This strict condition contributes to occurrence and self-organized development of the first convective cloud. We also show that requirements for the first cloud are convective instable, large CAPE and vertically big change of direction of wind. Moreover, our results bring that the constant ratio of buoyancy to turbulence is important for occurrence and development.