1951-2008年太原市霜冻发生特征分析

摘要：基于太原市1951～2008年逐日最低气温资料，采用线性倾向估计法分析了霜冻的发生趋势；利用异常霜冻指标，分析了霜冻的异常发生情况。结果表明：1)太原市平均初霜冻日为10月14日、终霜冻日为4月15日，平均无霜冻期为182d。2)初霜冻日在年代际间的变化较为复杂，终霜冻日则表现为50～70年代偏晚、80年代之后偏早，无霜期为50～70年代缩短、80年代之后延长为主的变化特点。3)太原市初、终霜冻日和无霜冻期的线性倾向率分别为2.2d/10a、-1.8d/10a和4.0d/10a；无霜冻期的延长趋势最显著，通过了 的显著性检验。4）太原市特早初霜冻发生频率为1.7%，偏早初霜冻发生频率为15.5%，特晚终霜冻发生频率为5.2%，偏晚终霜冻发生频率为6.9%；大多数异常霜冻发生在50～70年代。

Analysis on frost events occurrence at Taiyuan from 1951 to 2008

Abstract: Based on the daily minimum temperature data at Taiyuan meteorological station from 1951 to 2008, the first and late frost events occurrences series were established respectively. Basic characterics were analyzed by using statistical method and the change trends of them were analyzed by using the linear method and the unusual frost were also analyzed by comparing them with criterion. The results were listed below: (1) The first frost event occurred on Oct. 14th, the late frost event occurred on Apr. 15th and the frostless season was 182d on average. (2)Comparing with the average date, the first frost events occurred early in 1950s, 1960s and 1990s, normal in 1970s,late in 1980s and early 21st century; the late frost events ended late and frostless seasons were short in 1950s-1970s.After 1980s, they were early and long (3) The first frost events occurred towards a late trend obviously(2.2d/10a), the last frost was a ahead trend(-1.8 d/10a) and the frostless season was longer and longer. (4)The frequency of unusual first frost events took up 17.2% (including 1.7% for earliest and 15.5% for earlier respectively) and that of unusual late frost events took up 12.1%(including 5.2% for latest and 6.9% for later respectively).