秦岭南北降水小时尺度特征对比分析

Comparative analysis of hourly features of precipitation in the north and south areas of Qinling Mountains

利用秦岭地区1961-2015年暖季(4-10月)国家级地面气象站观测的逐时降水资料,从降水逐候变化与降水日变化的角度,比较了秦岭南北两侧暖季降水的演变特征,研究表明:在逐候演变上,秦岭南北两侧均为夏秋双峰型降水,但北侧降水主峰值出现在秋季,秦岭南侧降水主峰值出现在夏季。在降水日变化上,夏秋两季中南侧降水量、降水频次和降水强度均以清晨峰值为主,仅在降水频次上夏季出现了午后的次峰值;而北侧降水量日变化夏秋变化较大,且主要由降水强度贡献,夏季降水强度在午后较强,而秋季清晨降水强度更大。对于不同持续时间的降水事件,南北两个区域在夏秋均表现为持续9 h以上(3 h以下)的降水为清晨(午后)降水峰值,其差别主要存在于持续时间为4~8 h的降水事件中。

In this paper, we use the hourly precipitation data observed by the national ground weather stations in the Qinling region during the warm season(April-October) from 1961 to 2015 to compare the precipitation evolution on both sides of the Qinling Mountains from the perspective of pentad and diurnal features in precipitation. The research shows that the north and south sides of the Qinling Mountains have double-peak precipitation in summer and autumn. The main peak of precipitation appears in autumn on the north side, but in summer on the south side. In terms of the diurnal variation, the amount frequency and intensity on the southern side for summer and autumn seasons are all with the morning peak as the main peak. Only in the summer, the precipitation frequency has a secondary peak in the afternoon, while the diurnal variation of the northern side of the precipitation varies greatly in summer and autumn. The secondary peak is mainly contributed by the precipitation intensity, which is stronger in the afternoon in summer, and stronger in the early morning in autumn. In both north and south regions, precipitation events that last for more than 9 hours(less than 3 hours) get the peak in the early morning(afternoon) in summer and autumn, and the difference between the north and the south is mainly in the precipitation events that last 4-8 hours.