1983—2015年湖南雨凇时空分布特征及影响因子

Temporal and Spatial Distribution and Influencing Factors of Glazes in Hunan Province during 1983-2015

采用经验正交函数(EOF)并对1983—2015年湖南省95个地面气象站的雨凇观测资料以及与北半球海冰和西太平洋和东北印度洋海温资料的相关性进行分析。结果表明:湖南各站年均雨凇频次为2.19次,总体呈现北少南多、山区北侧少南侧多、平原地带少的分布特点;雨凇频次呈逐年下降趋势,且在湖南中北部地区下降趋势显著;湖南雨凇主要发生于相对湿度较大、极大风为偏北风且风速较小、最低气温在-3~0℃、最高气温在0~4℃的环境中。冬季同期(12月至次年2月),北地群岛以东至白令海峡以北海域海冰密度和湖南雨凇频次的相关关系为显著正相关关系,而西北太平洋海温和湖南雨凇频次的显著负相关区域表现为C型分布。

The relationship between glazes from 95 surface weather stations in Hunan Province and sea-ice density and sea surface temperature from 1983 to 2015 is studied by using the experimental orthogonal function analysis（EOF）.The results indicate that the frequency of glazes in Hunan Province was 2.19 per year with the feature of a higher incidence of glazes in south and the southern mountain area compared with the north,the northern mountain area and in the plain.The frequency of glazes shows a tendency of decrease with the increase of time.The glazes in Hunan Province mainly formed in the environment with the condition of high relative humidity,low wind speed and north wind,as well as the minimum temperature between 3 and 0 ℃,and the maximum temperature between 0 to 4 ℃.The number of glazes happened in Hunan Province in winter increased with the increase of the sea ice density from the east of the Severnava Zemlva islands to the north of the Bering Strait,while in the area with the remarkable negative correlation between the frequency of the glazes and the sea surface temperature of the Northwest Pacific,three existed a C-shaped distribution.