阻塞个例的动力学诊断分析

DYNAMICAL DIAGNOSIS OF A BLOCKING CASE

摘要:

本文利用欧洲中心球面网格点资料,对1981年10月4-27日维持于乌拉尔山区域的阻塞进行了初步的动力学分析。结果表明,本例中,位于阻塞上游的涡旋活动,类似于两大洋风暴路径后期处于衰弱期的涡旋,具有逆梯度的传输性质;类似于两大洋阻塞,涡动强迫过程同样存在于乌山阻塞的维持中;同时,乌拉尔山地形的作用也是不可忽视的。所以,在乌拉尔山区域涡动强迫作用和山脉地形影响一起维持阻塞。

Abstract:

On the basis of the spherical grid-point data from the ECMWF,a preliminary dynamical diagnosis is made of the blocking high whichpersisted over the Urals during October 4-27, 1981.Results show thatlike the decaying eddies on the track of the Atlantic and Pacificstorms at their last stage, the upstream eddies in this case have propertiesof upgradient transfer, and similar eddy forcing processes also exist inthe persistence of the Ural blocking. Furthermore, the orographic forcingof the Urals should not be neglected. In conclusion, the eddy forcingand the orographic effect of the Urals play a concurrent role in thepersistence of the blocking.