吉林省极大风速时空变化特征及其与气候变暖的关系

Spatio-temporal Variation Characteristics of Extreme Wind Speed in Jilin Province and Its Relationship with Climate Warming

利用吉林省1971—2018年最大风速及2005—2018年极大风速数据,采用阵风系数方法对1971—2004年极大风速进行估算,形成1971—2018年极大风速序列。在此基础上采用累积距平、极值Ⅰ型分布、Mann-Kendall检验等方法对极大风速的时空变化特征及其与气候变暖的关系进行分析。结果表明:(1)8级及以上大风随着风力级别的升高,出现站次迅速减少;(2)年内极大风速呈双峰双谷型特征,春、秋季为两峰,冬、夏季为两谷;(3)1970年代以来,吉林省年平均极大风速每10 a下降0.9 m·s^-1,超过8级的大风站次呈减少趋势;(4)吉林省平均极大风速、10~50 a一遇的极大风速都呈西北高、东南低的空间分布,长春站10~50 a一遇的极大风速最大,达33.9~40.7 m·s^-1;(5)年平均极大风速和气温呈明显的反相关和反位相关系,且在1988年前后发生突变,和东北地区气温突变同步;(6)尽管由于气候变暖,吉林省极大风速呈明显减小趋势,但仍有极端大风天气出现,2011—2018年10级以上大风出现95站次,还出现1站次13级以上大风,因此仍需加强大风灾害防御。

Based on maximum wind speed data from 1971 to 2018 and extreme wind speed data from 2005 to 2018 in Jilin Province,extreme wind speed data from 1971 to 2004 were estimated by using the gusty coefficient method,and then the sequences of extreme wind speed from 1971 to 2018 was formed.On this basis,the spatio-temporal variation characteristic of extreme wind speed and its relationship with climate warming were analyzed by using methods such as accumulated departure,extreme value distributionⅠtype,and Mann-Kendall test.The results are as follows:(1)With the increase of wind level,the occurrence frequency of gale above level 8 decreased rapidly.(2)The annual extreme wind speed had double peaks in spring and autumn and double valleys in winter and summer.(3)Since the 1970s,the annual mean extreme wind speed in Jilin Province decreased 0.9 m·s^-1 per decade,and the frequency of gale over level 8 showed a decreasing trend year by year.(4)The average extreme wind speed and the extreme wind speed under 10-year to 50-year return periods both showed the distribution with high values in the northwest and low values in the southeast,and the largest value of extreme wind speed under 10-year to 50-year return periods in Changchun ranged from 33.9 to 40.7 m·s^-1.(5)The annual mean extreme wind speed and annual mean temperature presented obvious inverse correlation and inverse phase relationship.The abrupt change of annual mean extreme wind speed occurred around 1988,which coincided with the sudden change of temperature in the northeast of China.(6)Although extreme wind speed in Jilin Province decreased obviously due to climate warming,there were still extreme gales.From 2011 to 2018,there were 95 gales above grade 10 and some gales were even above grade 13.Therefore,it is still necessary to strengthen gale prevention.