青藏高原高空流型对西太平洋台风路径影响的诊断分析  

DIAGNOSIS ON THE IMPACT OF MIDDLE TROPOSPHERE CIRCULATION PATTERN OVER THE QINGHAI XIZANG PLATEAU ON THE TRACK OF TYPHOON OVER WEST PACIFIC

作　　者：徐晶[1] 陈联寿[2] 徐祥德[2] 

机构地区：[1]国家气象中心,北京100081 [2]中国气象科学研究院,北京100081

出　　处：《应用气象学报》1999年第4期410-420,共11页Journal of Applied Meteorological Science

基　　金：国家自然科学基金

摘　　要：利用观测研究，动力诊断分析等手段，从上下游效应、中低纬相互作用的角度来探讨青藏高原高空天气系统的变化与西太平洋台风运动两者之间的关系．１９７０～１９９５ 年２５ 年间的统计结果表明，青藏高原高空流型与台风路径有如下关系：高原高空５００ ｈＰａ 为低值系统控制时，有利于台风西行；反之，高原高空５００ ｈＰａ 为高压时，近海台风往往转向．动力诊断分析的结果揭示了高原上空系统影响下游系统的物理机制，即高原上游扰动动能的传递使得下游的槽发展，并进一步影响台风的引导气流．高原脊的存在，使得涡动动能的输送通道偏北；高原上为槽时，涡动动能的输送通道偏南．高原槽前的南风和台风东侧南风将低纬度的低位涡输入副热带高压，有利于副热带高压的发展，影响台风运动，体现了中低纬相互作用对天气系统的影响．There is a close relation between the variation of middle troposphere synoptic system over the Qinghai Xizang Plateau and movement of typhoon over West Pacific, and the relation is studied with the observation study and dynamical diagnosis from the point of view of downstream development and interaction between mid latitude and low latitude. 25 year statistics results from 1970 to 1995 indicate that the relations between middle troposphere circulation patten over the Plateau and the track of typhoon over West Pacific are as follows: When low pressure system on 500 hPa isobaric surface occupies middle troposphere over the Plateau, it is beneficial to typhoon′s westward movement; on the contrary, high pressure system on 500 hPa isobaric surface is always beneficial to typhoon recurvature. The results of dynamical diagnosis show the physical mechanism of impact of synoptic system over the Plateau on downstream synoptic system, that is, the transport of disturbance kinetic energy over the upstream Plateau makes the downstream trough developed. And then it affects the steering flow of typhoon. Because of existence of the ridge over the Plateau, the eddy kinetic energy transport channel moves to the north.On the contrary,the trough exists ove the Plateau,so the eddy kinetic energy transport channel moves to the south.The southerly wind in front of the trough over the Plateau together with the southerly wind at the east part of typhoon transports low potential vorticity of low latitude into subtropical high.That is beneficial to development of subtropical high,and then subtropical high affects typhoon′s movement.These results fully reflect the impact of interaction between mid latitude and low latitude on synoptic system.

关 键 词：青藏高原 高空流型 台风路径 等熵位涡 涡动动能 

分 类 号：P444[天文地球—大气科学及气象学] P732.3