青藏高原地区近十年夏季降水日变化特征分析  

Diurnal variation characteristics of summer precipitation over the Qinghai-Tibet Plateau in the past 10 years

作　　者：刘雨晴 谷永利 李婵 刘焕莉 宋安祺 LIU Yuqing;GU Yongli;LI Chan;LIU Huanli;SONG Anqi(Hebei Meteorological Information Center,Shijiazhuang 050000,China)

机构地区：[1]河北省气象信息中心,河北石家庄050000

出　　处：《海洋气象学报》2025年第2期127-135,共9页Journal of Marine Meteorology

基　　金：国家重点研发计划“科技冬奥”重点专项(2018YFF0300100);河北省气象局科研项目(22kyd02)。

摘　　要：利用国家级地面气象观测站数据与CMORPH(Climate Prediction Center MORPHing technique)降水数据融合资料和欧洲中期天气预报中心再分析资料,讨论分析2010—2019年青藏高原地区夏季降水的日变化特征。结果表明:青藏高原地区整体夏季降水量和降水频率的日变化规律均表现为峰值出现在傍晚,谷值出现在中午。分区域来看,青藏高原南北区域夏季降水量日变化规律不同,南部地区降水量日变化规律与高原地区整体日变化规律相同,而北部地区日降水量峰值出现在上午,谷值出现在凌晨。分降水持续时间来看,短时降水比持续性降水出现频率更高,但持续性降水约占总降水量的70%。因河谷地貌和海拔高度分布特征,青藏高原地区夏季夜雨率的空间分布呈“中间高、南北低”态势。青藏高原地区风场和散度场的强度变化特征与降水发生区域及降水强弱相对应,因此散度的正负值强弱变化可能是高原地区降水强度变化的重要原因之一。The hourly emerged precipitation products,derived from the hourly precipitation observations by national meteorological observing stations in China and CMORPH(Climate Prediction Center MORPHing technique)data,as well as the reanalysis data of the European Centre for Medium-Range Weather Forecasts(ECMWF)are used to study the diurnal variation characteristics of the summer precipitation on the Qinghai-Tibet Plateau.The results are shown below.The diurnal variations of the summer precipitation and precipitation frequency over the Qinghai-Tibet Plateau show that the peak occurs at nightfall and the valley at noon.The diurnal variations of the summer precipitation in the northern and southern regions of the Qinghai-Tibet Plateau are different in that the diurnal variations in the southern region are the same as the diurnal variations of the total precipitation on the plateau,while the precipitation in the northern region shows its peak in the morning and the valley in the early morning.In terms of the duration of precipitation,short-term rainfall occurs more frequently than long-term rainfall,but about 70%of the total precipitation comes from long-term rainfall.Due to the features of valley landform and altitude distribution,the summer night rain rate on the Qinghai-Tibet Plateau is high in the middle and low in the northern and southern regions.The intensity variations of the wind field and divergence field over the Qinghai-Tibet Plateau correspond to the precipitation occurrence region and intensity.Therefore,the changes in the divergence may be one of the important reason for the changes in the precipitation intensity in the Qinghai-Tibet Plateau.

关 键 词：青藏高原 夏季降水 日变化 

分 类 号：P426.6[天文地球—大气科学及气象学]