廊坊市雷暴气候特征及区划研究

利用廊坊市9个气象站1964—2011年的雷暴日资料,通过数理统计、线性趋势拟合和小波分析,研究了廊坊市近48a来雷暴的时空分布特征和周期性特征,并结合信息扩散法,进行了不同雷暴日数下的概率区划.结果表明:廊坊市雷暴日的年际变化幅度较大,年均雷暴日数总体呈下降趋势,约每10 a减少2 d;廊坊市雷暴月、季变化呈明显的单峰型,雷暴主要发生在4—10月,其中夏季(6—8月)占全年的74.5%;中北部的雷暴日数明显多于南部地区;10 a及以上周期在绝大部分地区具有全域性,而短周期3~5 a大多表现在20世纪90年代之前;随着雷暴日数的增大,雷暴发生高概率区逐渐北移,当雷暴日数异常偏大(40 d)时,中部的部分地区也处于雷暴发生高概率区.

Climatic characteristics and regionalization of thunderstorms in Langfang

Using the data of thunderstorm days recorded by the 9 weather stations in Langfang of Hebei province from 1964 to 2011, the temporal-spatial distribution characteristics and periodicity features during the recent 48 years are analyzed by means of mathematical statistics, linear trend fittings and wavelets analysis.The regionalization of thunderstorm probability of different number of days is worked out by use of information diffusion theory.The re- suits show that the interannual thunderstorm variability is significant and the annual thunderstorm days has a decrea- sing trend.The numerical value of decreasing days is about 2d per decade.The seasonal variation exhibits a uni- peak-type and the thunderstorms mainly occur from April to October, while 74.5% of thunderstorms occur in the three-month of June, July and August during the summer.The thunderstorm days in north-central areas are signifi- cantly more than that in south.The variation periods are stable and exist across the whole region in most areas when they are more than 10a,but the short period of 3 to 5 years mainly happens before the 1990s.With the increase of the thunderstorm days, the high probability areas move north.Some of the central areas will be high probability areas when the thunderstorm days become abnormally high.