Atmospheric Free Modes and Subtropical High

By numerically solving the unforced and inviscid nonlinear barotropic vorticity equation through the quasi-Newton method, the steady free modes are obtained, which are very similar to the real flow fields, and their scatter diagram of (ψ, q) display segmented linear or nonlinear relations. From this scheme a range of free modes have been achieved, each corresponding to one of the atmospheric flow fields. In the study of changes in the western Pacific subtropical high (WPSH) as revealed by free modes it is discovered that the west-extension/northward jump and east-movement/southward withdrawal of WPSH for the free mode occur 5-10 days ahead of the changes in the high as shown in the 500 hPa geopotential height field. Besides,a standard mode technique is adopted to investigate the stability of the free modes, indicating that the faster the instable mode grows, the closer it comes to a quasi-steady state. Especially, the instable mode with its quasi-steady state growing the fastest bears a correspondence with the high in steady intensification, leading to the fact that the persistent strengthening of the high is likely to be caused by the instable free modes with the fastest growth that are of quasi-steady state, or experience long-period low-frequency variation.

作 者： TAO Li LU Weisong   作者單位： Nanjing University of Information Science and Technology, Nanjing 210044  刊 名： 氣象學(xué)報（英文版）  SCI 英文刊名： ACTA METEOROLOGICA SINICA  年，卷(期)： 2005 19(1)  分類號： P4  關(guān)鍵詞： free mode   western-Pacific subtropical high   instability  

【Atmospheric Free Modes and Subtropic】相關(guān)文章：

An estimate on the rainout of atmospheric CO204-26

EFFECTS OF THE ATMOSPHERIC COLD SOURCE OVER THE TIBETAN PLATEAU ON THE QUASI 4-YEAR OSCILLATION OF OCEAN-ATMOSPHERIC-LAN04-27

Bilateralism: New Thrust of Free Trade04-26

Free Trade/自由貿(mào)易05-04

Generation and Application of Spatial Atmospheric Turbulence Field in Flight Simulation04-26

Effect of atmospheric precipitation on the dissolved loads of the Dongjiang River,China04-26

My Free Time小升初英語作文04-25

China-ASEAN Free Trade Area:Ready?Go!04-26

第145講：set of wheels; free-wheeler05-04

Influence of the Haizhou Open Pit Coal Mine on the atmospheric flow over Fuxin,China04-25