宁夏固原市雷暴特征与气候变化分析

利用宁夏固原市建站以来1957--2006年地面气象观测记录的雷暴资料，对固原市雷暴的气候特征进行分析．结果表明，固原市雷暴的年际变化较大，年雷暴时间在20世纪90年代后有减少的趋势，且2000年后递减变化明显．雷暴时间主要集中在6—8月，占全年雷暴的67％，6月雷暴时间的年代变化从建站来呈准直线缓慢下降趋势，7月出现了双峰单谷型的变化趋势，8月出现了一个反正弦的周期变化．雷暴时间的月分布有明显的季节性，呈准正态分布．

Ningxia Guyuan city thunderstorm characteristic and climatic change analysis

Using the thunderstorm data which is surface weather observation and recorded by Guyuan station since it＇s constructed, about 50 years （1957--2006 years）; the climate characteristic of Guyuan thunderstorm was analyzed. The result indicated that there are large interannual variability of thunderstorm in Guyuan, thunderstorm time in years trend to decline after 1990＇s, and has declined markedly after 2000. Accounts for 67% of thunderstorms time in years mainly concentrates in June to August. The thunderstorm time in June has declined slowly with quasi-linear trend from the station constructed; and in July, there has double-peak-valley-type changing tendency; In August, it presents an anti-sine periodic change. The distribution of thunderstorm time in month has obvious seasonal characteristic, assumes the normal distribution.