摘要
利用华北地区51个气象站1965—2018年逐时降水资料,通过Bootstrap方法、Mann-Kendall(MK)检验、滑动t检验、Pettitt检验、小波分析(Morlet)、小波相干谱、交叉小波分析等方法,分析了华北不同分区(东区、北区、中南区)夏季持续性(持续时间大于6 h)降水过程的长期变化特征,以及各区域影响持续性降水的大气环流特征。结论表明:与其他两个区域相比,华北东区为持续性降水的多发区,该区具有降水量大、历时长、峰值雨强大的特点,54年以来该区持续性降水占总降水的场次比重、持续性降水量占总降水量比重均呈现减小趋势,但持续性降水的峰值雨强占降水量的比重呈增加趋势,持续性降水更加集中;北区持续性降水峰值雨强占比呈增加趋势;中南区持续性降水的趋势不显著。东区降水因子表现为以准8 a周期为主,降水历时和峰值雨强分别在1988和1989年左右出现周期突变,西太平洋副高脊线位置对该周期存在显著正向驱动,而北区和中南区降水分别以准4 a和准6 a为主,受ENSO的负向驱动。整个序列上,大气环流型对华北降水影响呈现显著区域分异特征,西太平洋副高脊线位置对东区降水历时影响显著,NAO异常与北区的降水量和降水历时变化关系密切,中南区降水量和降水历时主要受亚洲经向环流影响明显。
Using hourly summer rain data recorded at 51 automatic meteorological stations during 1965—2018,the secular variation features of the long-duration rainfall(the raining duration is longer than 6 hours,LDR)in three regions in North China were analyzed by methods of Boostrap Procedure,Mann-Kendall(MK)test,moving t-test,wavelet analysis,and cross wavelet analysis.The possible influence of atmospheric circulation on rainfall factors was described.The results show that the frequently occurred region of long-duration rainfall is the East plain of North China(EP)with the characteristics of larger precipitation,longer duration and greater intensity.The ratio of the frequency of LDR over the total rainfall,and the ratio of the amount of LDR over the total rainfall showed a decreasing trend,while the amount ratio of the hourly peak intensity over the rainfall event increasing in EP,which may lead to more concentrated rainfall.The amount ratio of the hourly peak intensity over the rainfall event increased in north mountain of North China(NM).In the last part named as central south of North China(CS),the trend of rainfall factors has little significance.The rainfall factors of EP were significantly driven by cycles of quasi-8 a,and the duration and peak intensity had an abrupt change of period between 1988 and 1989,respectively.Western Pacific subtropical high ridge position had positive driving force on such quasi-8 a period of rainfall in EP.The rainfall factors of NM have quasi-4 a and CS have quasi-6 a respectively,and ENSO mainly has negative driving force on these two periods of rainfall.The influence of atmospheric circulation on long-duration rainfall was regionalized.Western Pacific subtropical high ridge position had significant connections with the duration in EP,while the variation in amount and duration in NM was closely correlated with the NAO anomalies which were mainly influenced in CS by Asian Meridional Circulation.
作者
高旭旭
陈霞
于长文
邵丽芳
GAO Xuxu;CHEN Xia;YU Changwen;SHAO Lifang(Hebei Climate Center,Shijiazhuang 050021,China;National Major Meteorological Laboratory and Ecological Environment in Hebei Province,Shijiazhuang 050021,China)
出处
《自然灾害学报》
CSCD
北大核心
2021年第6期219-232,共14页
Journal of Natural Disasters
基金
国家自然科学青年基金项目(41705075)
河北省创新能力提升计划项目(19245419D)
暴雨洪涝灾害风险评估创新团队(20170004)。
关键词
小时降水
持续性降水过程
长期变化
区域分异特征
环流驱动
华北
hourly rain gauge data
long-duration rainfall
secular variation
regional differentiation
North China
