塔里木盆地及其周边地区大气可降水量分布及其与降水关系的研究

The Characteristics of Atmospheric Precipitable Water Vapor Distribution and Its Relationship with Precipitation over Tarim Basin and Its Surrounding Area

利用2018年7月至2022年6月塔里木盆地及其周边地区17部地基GPS水汽探测仪遥感的大气可降水量(PWV)资料、 14个地面气象站逐时和逐日降水资料,分析了塔里木盆地西部(区域A)和东部(区域B)PWV分布特征及其与降水关系。结果表明:(1)研究区年平均PWV高值区主要集中于盆地北部和盆地西南部平原地区,海拔超过1300 m站点的PWV年平均值与海拔成反比,低于1300 m的低海拔地区PWV年平均值在10~12 mm。夏季测站PWV平均值是春、秋季节的2倍。(2)区域A和区域B PWV月变化呈单峰型分布,分别在8月和7月达到峰值。区域A有、无降水日PWV均在23:00(北京时,下同)达到日峰值。区域B有、无降水日PWV日峰值出现时间相差5 h,分别出现在11:00和17:00。(3)区域A和区域B多数测站ΔPWV(PWV与PWV月平均值差值)峰值分别在降水开始前0~1 h和降水开始时刻前后1 h出现。春季区域B降水前PWV跃变程度较区域A更剧烈,夏季各区域σPWV(PWV与PWV月平均值倍数)提前降水开始时刻1 h、 5~6 h达到1~1.8倍的天气过程较其余时次偏多。秋季和冬季区域BσPWV分别集中在1.4~2.0倍和1.6~2.4倍。(4)海拔高于1400 m测站的5-6月、 7-8月PWV值达到10~20 mm和15~25 mm,对应降水结束时刻。海拔低于1400 m测站5-8月降水结束时刻PWV值逐渐由15~25 mm增至25~35 mm。

Using the precipitable atmospheric water vapor(PWV)data of 17 ground-based GPS remote sensing stations,hourly and daily precipitation data of 14 meteorological stations in Tarim Basin and its surrounding areas from July 2018 to June 2022,this study analyzed the PWV distribution characteristics and its relationship with precipitation in the western(region A)and the eastern(region B)part of Tarim basin.The results show that:(1)The average annual PWV is largest in the northern and southwestern plain areas of the basin,and the average annual PWV is inversely proportional to the altitude at stations with over 1300 m,while that concentrated on 10~12 mm at stations with altitude below 1300 m.The average PWV value in summer is twice than that in spring and autumn at all GPS stations.(2)The monthly distribution of PWV in region A and region B presents a unimodal type,with the peaks occurred in August and in July,respectively.On the rain-day and no-rain day in region A,the both peak value of PWV occurred at 23:00(Beijing Time,after the same),While,the peak value of PWV occurred at 11:00 on rain-day and 17:00 on no-rain day in region B,respectively.(3)The peak ofΔPWV(PWV minus monhly mean PWV)at most stations occurred at 0~1 h before precipitation start time in region A,and within 1 h before and after precipitation in region B.In spring,the variation of PWV before the precipitation in region B is more severe than that in region A.In summer,there are more weather processes withσPWV(PWV divide monthly mean PWV)reached 1~1.8 times at 1 h and 5~6 h before the beginning of precipitation in region A and region B.In autumn and winter,The peak ofσPWV are concentrated in 1.4~2.0 times and 1.6~2.4 times in region B,respectively.(4)At the end of precipitation in stations with altitude below 1400 m,the PWV value was concentrated in 10~20 mm during May to June and in 15~25 mm during July to August.In stations with altitude over 1400 m,the PWV value is increasing from 15~25 mm to 25~35 mm from May to August at the end of precipitation.