夏季副高位置的变化规律及其与福建干旱的关系分析

Variation of subtropical high and an analysis of its relationship with drought in Fujian during summer

本文应用子波分析和功率谱等方法揭示夏季副高脊线位置的变化规律,进而分析脊线位置与福建夏季干旱的关系.主要结论有:(1)夏季副高脊线位置在20世纪80年代是异常偏南的频发时段,20世纪60年代和90年代是异常偏北的频发时段;且存在较为明显的准3～5、7、9a和13a周期振动,特别是准9a的周期振动相当显著(2)夏季副高脊线位置处于偏南(北)状态时,福建夏季易于(不易于)出现干旱;(3)夏季副高南界位置处于偏南(北)状态时,将影响到福建夏季降水;2003年夏季副高南界位置偏南与福建夏季严重干旱有着密切的联系,其振动对中低纬度地区值得注意.

By using wavelet analysis and power spectrums with the variation of subtropical high ridge in summer were revealed and the relationship between the subtropical high ridge and summer drought in Fujian Province was analyzed. The results are as follows ： （ 1 ） The subtropical high ridge frequently located southward to its normal position in 1980＇ s while northward in 1960＇ s and in 1990＇ s.Quasi 3 to 5-years, 7-years, 9-years and 13-years periodic oscillations are found,amchg which the 9-years oscillation is most remarkable. （2）During summer, drought is likely （unhkely） to occur in Fujian when the subtropical high ridge locates southward （northward） to its normal position. （3）In the summer of 2003, the southern boundary of the subtropical high is close related to the severe drought in Fujian, and its oscillation have an impact on the weather over mid and low latitudes.