Upper Wave-East Asian Jet Interaction during the Period of Cold Wave Outbreak
寒潮期间高空波动与东亚急流的相互作用

In this paper, the upper wave-East Asian Jet interaction during the period of cold wave outbreak is studied . The following results are obtained :1. Due to the momentum and heat transportation of upper waves , East Asian Jet is acceler -ated . At the same time , mass meridional circulation in the jet entrance is strengthened . 2. The enhancement of mass meridional circulation induces a little fall of the tropopause in the middle-high latitude , and steepens the slope of the upper level front. 3. Both the fall of tropopause and steepening of the front slope reinforce that the air current in the lower layer of the stratosphere flows into the troposphere through the region of tropopause fold. In this way, the distribution of potential vorticity in the middle-upper layer of the troposphere is changed . 4. The change of the potential vorticity distribution often restricts the energy supply for the baroclinic wave development. As a result, upper waves are weakened .