The Evolution of Siberian High Prior to the Outbreak of Cold Air
冬季风爆发前西伯利亚高压的演变

The main objective of the present study is to estimate the contribution of different physical processes by calculating the quasi- Lagrangian heat and vorticity budgets of the Siberian high. The case selected in this study is a Siberian high prior to the outbreak during early winter, 12-17 November 1979. The results suggest that the dynamic process of the transferse circulation of the upper-level jet should be emphasized in the intensification of cold dome. The radiative cooling is probably a secondary factor compared with the adiabatic cooling. The results from the diagnose of the vorticity equation indicate that the relative vorticity advection is pronounced in the mid-and upper-troposphere. The deepening of downstream trough is essentially a transformation from shearing to curvature vorticity. The divergence term is considerable except at middle levels and has opposite tendency against the advective effect.The present result are helpful to understand the physical mechanism of the intensification of cold dome and the Siberian high.