华北—华东地区高温热浪与土壤湿度的关系研究

Relationship between summer heat waves and soil moisture in North-East China

利用观测站点的日最高气温、土壤湿度旬观测资料以及土壤湿度再分析资料等,分析了华北—华东地区高温热浪次数的时空变化特征及其与土壤湿度的关系。结果表明:1960s以及1990—2010年为高温热浪次数的高值期,1970s—1980s为低值期。利用旋转经验正交函数分解得到土壤湿度的3个气候分区,分区内前期(3—5月)和同期(6—7月)的土壤湿度与6、7月份高温热浪次数基本呈负相关关系,并且同期相关性更显著。在华北—华东北部与中部,5月下旬土壤湿度与6月高温热浪次数、6月上、中旬平均土壤湿度与6月高温热浪次数、7月平均土壤湿度与7月高温热浪次数的相关性均显著。

Based on the summer daily maximum temperature data, soil moisture observation data ofevery ten days and soil moisture reanalysis data, the temporal and spatial distribution characteristics ofthe occurrence of heat waves and its relationship with soil moisture in North-East China were analyzed.Results show that in 1960 s and 1990-2010 heat waves occurred frequently, while 1970s-1980 s was thelow occurrence period. The rotated empirical orthogonal function（REOF） was used to obtain three soilmoisture climate zones. Within each region, soil moisture in early（March-May） and corresponding peri-od（June-July） were negatively correlated with heat wave occurrence in June and July, and more signifi-cant correlations existed in the corresponding period. In the northeastern and central North-East China,the average soil moisture in late May was significantly related with heat wave occurrence number in June,the average soil moisture in early and mid-June depended remarkably on heat waves occurrence numberin June, and the same as in July.