基于地基GPS的新疆地区大气可降水量时空分布特征

Temporal-Spatial Distribution Characteristics of Precipitable Water Vapor in Xinjiang Based on Ground-Based GPS

利用中国大陆构造环境监测网络的GPS观测资料,结合ERA-Interim模型气压和温度,解算2016年新疆地区GPS测站的大气可降水量,分析该地区大气可降水量的空间分布和季节性变化。结果表明:1)GPS和探空观测获取的大气可降水量具有较好的一致性,均方根误差约为2.7mm;2)新疆地区全年平均大气可降水量在7.0～13.0mm之间,且海拔每升高1km,其含量减少约1.4mm,当测站海拔相近时,大气可降水量随纬度的升高而减少;3)大气可降水量季节性变化明显,夏季为12.0～23.2mm,冬季为1.4～5.5mm,春、秋季大气可降水量差异不大且变化范围介于夏、冬季之间。

The precipitable water vapor of stations in Xinjiang in2016is derived,according to the GPS data of the crustal movement observation network of China,combined with the pressure and temperature of the ERA-Interim model.The spatial distribution and seasonal variation of precipitable water vapor in this area are also analyzed.The results show the feasibility of GPS precipitable water vapor according to the comparison of radiosonde and GPS precipitable water vapor,which has a root mean square error of about2.7mm.Secondby,the annually averaged precipitable water vapor in Xinjiang is from7.0to13.0mm.Altitude is the main factor affecting the spatial distribution of GPS-derived precipitable water vapor;that is,precipitable water vapor decreases by about1.4mm for each kilometer increase of altitude.For regions at the same altitude,a region that is located at a lower latitude will have a higher content of precipitable water vapor.Thirdly,the seasonal variation of the precipitable water vapor is apparent.The precipitable water vapor is maximum in summer from12.0to23.2mm,the minimum is in winter,from1.4to5.5mm.The difference of precipitable water vapor between spring and autumn is quite small,and the changes are between summer and winter.