熱的勾配が駆動する渦度場の解明とデータ同化実験

Abstract

In this research, potential temperature gradient based vorticity which is the expression of baroclinic is obtained to analyze the energy structure of the vorticity field in developing clouds. First, applying the variational method enables us to obtain a diagnostic equation in which the equation of motion, conservation law of mass, and entropy are considered as constraints. Second, Fourier analysis was performed on the vorticity field in the cross-section of the convective core in the isolated cumulonimbus simulation. The temporal change of the spectrum of vorticity field indicates that the rotational intensity of potential temperature gradient based vorticity increases as the degree of baroclinicity increases. Third, we conducted the data assimilation experiment assuming the use of vertical vorticity estimated by doppler radar observation. The change in the potential temperature and vertical wind through the error covariance matrix generates coherent convection in the computations.