雷州半岛雷暴频数变化特征研究

对雷州半岛近50 a来的年雷暴日数变化时间序列进行小波分析,揭示了其雷暴频数多时间尺度的复杂结构,结果表明:雷州半岛平均年雷暴频数线性拟和呈现缓慢下降趋势;平均年雷暴日91 d,1983年及以前基本高于年平均值,1984年之后均低于年平均值;平均年雷暴频数总体趋势为1983年前正距平,1984年后为负距平;在20世纪60年代中期存在准2 a的周期变化,70年代存在显著的2-4 a的周期变化,80年代末至90年代末存在显著的3-4 a的周期变化,在90年代中后期存在显著的准2 a的周期变化。

Characteristics of the Number of Thunderstorm Days on Leizhou Peninsula

The characteristics of the time serial of thunderstorm days on Leizhou Peninsula are analyzed on the basis of near 50 years by using the method of wavelet analysis.The research revealed the multi-time scale complex structure of the number of thunderstorm days.The results show that there is obvious decreasing tendency in the annualmean days of thunderstorm;the annualmean days of thunderstorm is 91d,it is higher than the annualmean before 1983,and lower than annualmean after 1984;there is positive departure before 1983,negative departure after 1984;there are quasi 2-year period-oscillations in the mid 1960s,and obvious 2-4 year period-oscillations in 1970s,and obvious 3-4 year period-oscillations in the late 1980s to the late 1990s,obvious quasi 2-year period-oscillations in the mid and the l late 1990s.