东亚夏季两类阻塞高压维持的诊断分析

DIAGNOSTIC ANALYSIS OF MAINTENANCE MECHANISM FOR TWO KINDS OF EAST ASIAN BLOCKING HIGHS IN SUMMER

文章对两类东亚阻塞高压维持进行了诊断分析，结果表明：两类阻高的准地转位涡的平均流输送和瞬变扰动气流输送的分布是不同的，阻高维持机制也可能不同；两类阻高的瞬变扰动在分流区呈现南北向拉长，产生形变，对阻高维持有一致的作用；天气尺度扰动在东移过程中尺度缩小，当能量转化服从双向转化原则时，有大量扰动动能向平均场转化，使阻高维持．

The maintenance mechanism of two kinds of blocking highs is studied. The results show that the distribution regimes of mean flow transfer of quasigeostrophic potential vorticity and transient disturbance flow transfer for two kinds of blocking highs are different, and their maintenance mechanism would be different too. The transient disturbance fields of two kinds of blocking highs in diffluent regions appear to be elongate in the northsouth direction. This kind of deformation plays an important role in the maintenance of blocking high.It is also shown that the synoptic scale disturbance would reduce its scale in the process of eastward movement, when energy transformation obeys the bidirectional transformation principle, a lot of disturbed kinetic energy would transfer to mean fields, and so, blocking high could be maintained.