梅州市近61年低温霜冻气候变化特征

Climate Characteristics of Low Temperature and Frost Weather in Meizhou

利用梅州市气象观测站1952—2012年低温、霜冻资料,采用线性回归、小波分析和Mann-Kendall非参数检验等方法,分析梅州市近61 a来的低温、霜冻气候变化特征。结果表明,梅州低温、霜冻日数呈明显减少趋势;12月和1月是低温、霜冻天气出现最多的2个月份,占总日数的70%以上。初低温日和初霜冻日存在延后趋势,终低温日和终霜冻日存在提前趋势。20世纪80年代初低温、霜冻强度开始减弱,低温、霜冻日数也在此时期发生突变减少。低温日数存在2—4 a、7 a和10 a的周期变化,霜冻日数存在2—4 a、6—7 a和10 a的周期变化。根据低温、霜冻天气出现的主要两类天气形势,再结合单站气象要素特征,归纳总结低温、霜冻天气的预报指标和经验。

By using methods of linear regression,wavelet analysis and Mann-Kendal nonparametric test,the climate characteristics of the low temperature day（LTD,with the lowest temperature≤5 ℃）and frost day（FD）during 1952-2012 in Meizhou have been studied. Results show that the LTD and FD in Meizhou appear a decreasing trend over the past 61 years. Low temperature and frost weathers mostly occur in December and January,and both the numbers of LTD and FD in these two months are more than 70% of total. The beginning dates of low temperature and frost show a delaying trend,and both of their ending dates present an earlier trend.In the early 1980 s,both the low temperature and frost strengths decreased,also the abrupt reductions for LTD and FD occurred.LTD presented 2-4 a,7 a,and 10 a period oscillations,and FD had 2-4 a,6-7 a and 10 a period oscillations.According to the meteorological elements of local weather station,some of low temperature and frost forecasting indicators and techniques are summarized for local weather forecast.