A Semicircle Theorem on the Spectral Distribution in Transverse Instability Perturbation
不稳定横波型扰动谱点分布的半圆定理

The spectral distribution of the transverse instability perturbation is theoretically studied. A semicircle theorem on the spectral distribution in transverse instability perturbation is derived. The theorem reveals that this distribution is in the lower semicircle of complex plane with the centerend ra-dius R0. The results show that the shorter the wavelength, the higher the mode top and the latitude, the larger the vertical shear of basic flow and the absolute value of static stability parameter, the larger the radius.