冬季全国性寒潮识别标准及其气候变化特征

Identification Criteria of Nationwide Cold Wave and Its Climate Change Characteristics in Winter

利用全国1995个气象站1961-2016年56个冬季逐日最低气温和降水量资料,确立了全国性寒潮和干湿的识别标准。在此基础上对冬季106次全国性寒潮进行了气候特征分析。结果表明:20世纪60年代是冬季全国性寒潮频发期,随后缓慢减少;12月最易发生寒潮;寒潮过程持续2~3天的频次占95%,最长可持续5天。全国性寒潮影响最多的地方,集中在内蒙古中部、东北南部以及陕北和山西北部,华东大部是全国性寒潮影响次多的地方。沿天山、陕甘宁青、华北大部、西南偏西地区、河南省等地易在24 h达到寒潮标准,占4成;华东大部主要在48 h达到寒潮,占3成;东北地区、内蒙古中部、北疆以及华东南部和岭南北部更易在72 h达到标准。强寒潮有21次,20世纪60年代最多,21世纪00年代次之;超强寒潮仅发生3次,最后一次出现在1980年1月,达到超强寒潮标准多是在48 h或72 h;这两种级别寒潮亦多持续2~3天。干和较干寒潮过程易出现在12月至次年1月,在2月湿和较湿过程寒潮较多,均占6成;强寒潮以干过程居多,超强寒潮干湿特征不明显。

This paper developed national criteria for nationwide cold wave and dry and wet characteristics based on the daily the minimum temperature and precipitation data of 1995 meteorological stations over China in winter from 1961 to 2016. The climatic characteristics of 106 nationwide cold waves in winter were analyzed. Firstly,the winters of 1960s was a period of frequent national cold waves,followed by a slow decrease. Secondly,December is the most prone to suffer cold waves. Thirdly,the frequency of the cold waves process lasting 2 to3 days accounted for 95%,and the longest duration could be 5 days. Central Inner Mongolia,the southern Northeast China,northern Shaanxi and northern Shanxi were the most affected areas of the national cold waves,and most of the eastern China was the secondary affected area. Along the Tianshan Mountains,Shaanxi,Gansu,Ningxia,Qinghai and most of North China,the west-southwest areas,as well as Henan province were easy to suffered cold waves in 24 hours with a ratio of 40%. Most of east China suffered cold waves in 48 hours with a ratio of 30%. Northeast China,central Inner Mongolia,Northern Xinjiang,southern East China and northern Lingnan were more likely to suffer cold waves in 72 hours. There were 21 strong cold waves occurred at most in1960s and then in 2000s. Super cold waves occurred only 3 times,which was often generated in 48 or 72 hours and the last was in January 1980. Notably,both the two kinds of cold waves as mentioned above had a duration of 2 to 3 days. Dry and relatively dry cold wave processes tended to generate in December and January,and wet and relatively wet processes tended to generate in February,both for a proportion of 60%. The characteristics of the major strong cold waves were dry process but of the super cold wave were not obvious.