山西东南部气候变暖背景下的霜冻特征分析

摘要

应用山西省东南部11个气象观测站1971-2010年春秋季及年平均气温、初终霜冻日期及无霜期资料，采用数理统计对比法，分析了该地初终霜冻的时域分布特征及成因，气候变暖背景下初终霜冻日期及无霜期的变化特征。结果表明：气温年际变化在1971-1996年属震荡缓慢升温期，1997年开始趋于明显增暖期，气候变暖速率为0．3℃·10a-1；初终霜冻日期的时域分布与特殊的地理环境条件关系密切；在秋季气候变暖前提下，初霜冻出现日期的推后速率为2 d·10a-1，其年际变化趋势表现为正负震荡推后期、偏早期和平稳推后期三个阶段；春季平均气温的增温速率为0．25℃·10a-1，对应终霜冻出现日期呈现为提前趋势，提前速率为4 d·10a-1，年际演变特征可分为偏晚期、偏早期、正负震荡期、偏早期四个阶段；无霜期在气候变暖背景下，年际变化特征可分为延长期、缩短期和平稳延长期三个时期，无霜期的线性变化延长速率为7 d·10a-1。%Based on the data of average temperature,first-last frost dates and frost-free period in spring,autumn season and year from 1971 to 2010 in 11 weather stations at southeast Shanxi province,the time-space distribution char-acteristics and genesis of the first-last frost and the variation characteristics of first-last frost dates and frost-free period under the background of climate warming were analyzed by using the mathematical statistics and contrast methods .The results showed that:The annual temperature change during 1971-1996 was belonged to the slow warming period with oscillation,After 1997 the climate started to be the apparent warming period,the climate warming rate was 0 .3℃· 10a-1 .The time-space distribution of the first-last frost was the close relation with the special geographical environment conditions .Under the precondition of the autumn climate warming,the occurrence of the first frost date pushed back rate was 2 d·10a-1,the inter annual variation trend showed three stages as positive and negative oscillation push later peri-od,partial early period and smoothly push later period.The average warming rate in spring season was 0.25℃·10a-1, the corresponding appearance of last frost date presented an advance tendency,the advance rate was 4 d·10a-1 .The in-ter annual variation characteristics can be divided into four stages as partial later period,partial early period,positive and negative oscillation period and partial early period .Under the background of climate warming of the frost-free period,the inter annual variation features could be divided into three stages as extended period,shrinkage period and stable exten-sion period,the linear change extended rate of frost-free period was 7 d·10a-1 .