豪雨の「種」を捉えるための都市気象LESモデルの開発と積雲の生成に関する研究

Abstract

Localized torrential rainfall disasters in rainy season is called as “Guerrilla-heavy-rainfall disasters” in Japanese media. This kind of rainfall disaster is caused by single or multi isolated cumulonimbus clouds that grow rapidly within one hour since its generation. Nakakita et al. (2014) found that it is important to detect the clouds at its “baby-cell” stage earlier using X-band weather radar, and to predict the risk of disaster by vertical vorticity in a cumulonimbus cloud at its developing stage. However, the radar cannot detect the “convection genesis”, i.e. air motion of thermal without precipitation particles. This trigger of generating baby-cell is concerned to be much affected by urban area. So the purpose of this study is to develop an urban meteorological model based on large-eddy simulation (LES) intended to clarify the convection genesis.