秦岭山地夏季降水的时空变化特征及其气候归因

The Spatio-temporal Variation Characteristics and Climate Attributions of Summer Precipitation in the Qinling Mountains

探究秦岭山地夏季降水及其大气归因,是为了研究区域环境对全球气候变化的响应关系。根据1959—2022年陕西省秦岭山地32个气象站点数据和15个大气环流指数,运用一元线性回归法和小波变换分析法(CWT),研究了秦岭山地64年来夏季降水的时间变化特征和空间演变规律及其与大尺度环流指数的关系。结果表明,1959—2022年秦岭山地夏季降水呈现不显著的上升趋势,一元线性回归法的变化速率为10.81 mm/10 a。其中,秦岭山地南坡的商南站降水量变化率最大,为19.3 mm/10 a。秦岭山地夏季平均降水量为344.34 mm。位于秦岭山地南坡的紫阳县降水量最大,约为469.35 mm。位于秦岭山地北坡的华阴县降水量最少,约为216.51 mm。秦岭山地南坡夏季降水明显多于北坡,降水量约为107.68 mm。南坡夏季平均降水量约为377.99 mm,北坡夏季平均降水量约为270.31 mm,均未通过显著性检验。秦岭山地64年来的夏季降水量与SOI、SAODI、SWACI均有较强的正相关关系,与EASMI、SCSMI、SASMI均存在负相关关系。

Exploring the summer precipitation and its atmospheric attributions in the Qinling Mountains has research value and significance for studying the response of the regional environment to global climate change.Based on data from 32 meteorological stations and 15 atmospheric circulation indices in the Qinling Mountains of Shaanxi Province from 1959 to 2022,univariate linear regression method and wavelet transform analysis(CWT)are used to study the temporal and spatial evolution characteristics of summer precipitation in the Qinling Mountains over the past 64 years,as well as its relationship with large-scale circulation indices.The conclusions obtained are as follows:summer precipitation in the Qinling Mountains has shown an insignificant upward trend in the past 64 years from 1959 to 2022,and the change rates of the univariate linear regression method is 10.81 mm/10 a.It was found that the precipitation change rate at Shangnan Station on the southern slope of the Qinling Mountains is the highest,with a change rate of 19.3 mm/10 a.The average summer precipitation in the Qinling Mountains region has been 344.34 mm.Ziyang County,located on the southern slope of the Qinling Mountains,has the highest precipitation,approximately 469.35 mm.Huayin County,located on the northern slope of the Qinling Mountains,has the lowest precipitation,approximately 216.51 mm.The summer precipitation on the southern slope of the Qinling Mountains has been significantly higher than that on the northern slope,with a precipitation of approximately 107.68 mm.The average summer precipitation on the south slope is about 377.99 mm,and the average summer precipitation on the north slope is about 270.31 mm,both of which have not passed the significance test.The 64 year summer precipitation in the Qinling Mountains has a strong positive correlation with SOI,SAODI,and SWACI,while a negative correlation with EASMI,SCSMI and SASMI.