The Development of disturbance on the atmospheric density stratification

Abstract

 There are many unknown issues about line-shaped rainbands (LRBs) which is one of the meso-scale meteorological phenomena making torrential rainfall events in Japan. For disaster prevention, it is very important to reveal the formation mechanism of LRBs. In order to know the mechanism, the authors try to examine the instability of the density stratification. In this study, the rainfall and thermodynamic effects are not considered. To simplify the discussion, this theory considers only the up/down motion of the disturbance in the stratified atmosphere. Using this theory, the authors correlate the region of horizontal disturbance and the two parameters which characterize the shape of LRBs, i.e. the Froude number and the rate of density difference.