西太平洋副高位置变动与大气热源的关系

THE RELATIONSHIP BETWEEN THE POSITION VARIATION OF THE WEST PACIFIC SUBTROPICAL HIGH AND THE APPARENT HEATING

采用NCEP/NCAR再分析逐日资料和SCSMEX等资料,根据全型垂直涡度倾向方程,研究了1998年6月西太平洋副高位置变动与大气热源的关系。结果表明,副热带地区的非绝热加热对副高位置变化有很重要的作用。与气候平均状况相比,1998年6月副高北侧的非绝热加热垂直变化较常年偏强,而南侧较常年偏弱。这种异常的非均匀加热状况导致我国华南、江南、长江中下游地区呈现异常气旋性涡度制造,而中南半岛大部和南海地区为异常反气旋性涡度制造,使得1998年6月副高位置异常偏南。

Using NCEP/NCAR daily reanalysis data and SCSMEX data, an investigation is carded out of the relationship between the position variation of the west Pacific subtropical high （WPSH） and the apparent heating in June 1998 based on the complete vertical vorticity equation. It is found that the non-adiabatic heating plays an important role in the position variation of WPSH. In comparison with climatic mean status, the vertical change of non-adiabatic heating is stronger in the north side of WPSH in June 1998, but weaker in the south side of WPSH. The anomalous non-uniform heating induces anomalous cyclonic vorticity in South China, areas to the south of the Yangtse and its mid-lower valleys, but anomalous anticyclonic vorticity in the Indo-China Peninsula and South China Sea areas lead to the more southward position of WPSH than the mean.