北半球E-P通量分析及其与副热带高压的关系

Study on the Northern Hemisphere E-P Flux and Its Relation with Subtropical High

利用北半球 1 951— 2 0 0 0年冬季 (1月 ) 2 0 0 h Pa、50 0 h Pa的月平均资料 ,计算出 E- P通量 ,并根据平均环流的 E- P通量剖面图 ,研究了北半球冬季在大地形作用下 ,波动对基本气流的作用 ,以及波流相互作用下行星波的传播。北半球冬季平均 E-P通量的辐合辐散与地形作用形成的大槽大脊相对应 ,其强度也与槽脊的强度相一致。另外 ,根据多年夏季 (7月 )的月平均高度场、风场及降水资料得到 E- P通量和副热带高压的关系 ,进一步得到 E- P通量与异常天气的关系。

An E-P flux is computed based on the monthly mean data of 200hPa and 500hPa in the Northern Hemisphere winter(January) from 1951 to 2000.According to the cross-section diagram of the E-P flux ,the effect of wave motion on basic flow and the propagation of the planetary-wave due to wave-stream interaction under orographic influence are investigated.The divergence or convergence of the E-P flux in the Northern Hemisphere winter(January) is corresponding with the trough and ridge generated by the orographic effect,and their intensities are also consistent with each other.In addition,the relation between E-P flux and abnormal weather is obtained in line with the link,which is gained from the monthly mean (1951-2000) data of geopotential height,wind and rainfall in summer(July) in the Northern Hemisphere,between E-P flux and subtropical high.