对流层上层定常波异常遥相关型的维持机制

MAINTENANCE MECHANISMS OF UPPER TROPOSPHERIC STATIONARY WAVE ANOMALY TELECONNECTION PATTERNS

  • 摘要: 用ECMWF1980-1988年的资料和主成份分析方法研究了北半球冬季定常波月平均异常的空间结构和时间变化,分析了对应主要异常型的由辐散风和瞬变涡度通量的异常引起的涡度源异常,并用正压模式研究了涡度源异常在这些异常型维持中的作用。结果表明,瞬变的涡度通量辐合的异常有抵消辐散风所产生的涡度源异常的趋势;单独考虑辐散风异常作为强迫所产生的环流异常与遥相关型的结构和强度相差很大,但如果将瞬变涡度通量辐合的异常也包含到强迫源中,则强迫出来的环流异常会有很大改善。

     

    Abstract: The spatial structure and time variations of Northern Hemisphere winter upper tropospheric stationary wave ano malies are studied with the ECMWF DATA of 1980-1988 and PCA(Principal Component Analysis)method.The vorticity source anomalies of the main teleconnection patterns are analy sed and their roles in the maintenance of the stationary wave anomaly teleconnection patterns are investigated with the barot ropic model.The results show that the anomalies of transient vorticity flux convergences tend to cancel the anomaly of vorticity sources generated by divergent winds.The stationary wave anomaly patterns caused by divergent wind anomaly only are very different from that of the observations,but,if the anomalous transient vorticity flux convergences are also included in the vorticity sources,the simulated patterns will be greatly improved.

     

/

返回文章
返回