初夏西太平洋副高南北位置长期变化的成因及预报

THE CAUSE AND FORECAST OF LONG-TERM CHANGE OF THE LATITUDINAL POSITION OF WEST PACIFIC SUBTROPICAL HIGH IN EARLY SUMMER

关键词:  初夏  西太平洋副高位置  长期变化成因  脊线位置预报

Key words:  Early summer  Latitudinal position of West Pacific Subtropical High  Cause in long-term change  Prediction of the ridge line position

摘要:

利用月平均高度场和海温场资料,通过统计相关分析,探讨了初夏西太平洋副热带高压南北位置长期变化的规律及其成因,结果表明,初夏副高南北位置存在着11年左右和3-5年的准周期振荡,这种周期变化分别与太阳活动、海洋下垫面和对流层上部位势高度场类似的周期振荡相吻合。太阳黑子高值年、赤道东太平洋暖水期、热带中东太平洋对流层上部位势高度偏高阶段,初夏西太平洋副高位置偏南,反之偏北。最后建立了6月份副高脊线的预报方法。

Abstract:

In this paper, using data of monthly mean geopotential height and SST in a statistic-relation analysis, the regularity and cause of long-term change of the latitudinal position of West Pacific subtropical high in early summer have been studied. The results indicate that there seems to have about 11-year and 3-5 year quasi-lleriods. The quasi-periodicity is closely associated with the changes in solar activity, SST in the eastern equatorial Pacific and the geopotential height in the upper troposphere in central and eastern tropical Pacific in Northern Hemisphere. The high's position tends to be more to the south of its normal location corresponding to peak years of sunspot and warm episodes of SST and positive phases of the geopotential height. Vice verse. According to the above conclusion, the forecast criterion of the ridge line of West Pacific Subtropical High for June has been found. Its foreeast results are satisfactory.