中国不同气候区域GNSS水汽探测精度及时序特征分析

Analysis of GNSS water vapor detection accuracy and temporal sequence characteristics in different climate types in China

针对中国区域不同气候类型和不同季节的大气水汽信息探测难题,尤其是大气可降水量(PWV),研究利用中国内地构造环境监测网络(CMONOC,简称陆态网)2018—2022年30个GNSS测站解算数据、25个探空站数据和欧洲中期天气预报中心(ECMWF)ERA5数据,联合实验反演水汽(GNSS-PWV2),并分析水汽信息的长时序变化特征。结果表明,反演水汽(GNSS-PWV2)相比陆态网对流层产品中的水汽(GNSS-PWV1)探测精度有显著提升效果。GNSS-PWV2的平均绝对误差(MAE)与均方根误差(RMSE)范围分别为1.00~2.77 mm和1.24~3.28 mm。实验对比分析了5种不同气候区,反演水汽GNSS-PWV2在冬季精度最高,春季和秋季次之,夏季最低。GNSS-PWV2在温带季风、温带大陆和高原高山气候区的冬季精度改善效果明显,RMSE分别降低了49.84%、63.00%和79.43%;而在亚热带季风和热带季风气候区则春季的改善程度更高,RMSE分别降低了36.67%和58.91%。PWV年变化规律具有先上升后下降的特征,全年PWV值在0~80 mm范围内波动。

Aiming at the difficult problem of atmospheric water vapor information detection in different climate types and seasons in China, especially the atmospheric precipitable water vapor(PWV),this paper studies the joint experiment inversion of precipitable water vapor(GNSS-PWV2) using the data of 30 GNSS stations, 25 sounding stations and ERA5 data from crustal movement obervation network of China(CMONOC) in 2018 and 2022,and analyzes the long-term change characteristics of precipitable water vapor information. The results indicate that the inversion of precipitable water vapor(GNSS-PWV2) has a significant improvement in detection accuracy compared to the precipitable water vapor(GNSS-PWV1) in the terrestrial troposphere products. The mean absolute error(MAE) and root mean square error(RMSE) ranges of GNSS-PWV2 are 1.00~2.77 mm and 1.24~3.28 mm, respectively. The experiment compared and analyzed five different climate regions, and the inversion precipitable water vapor GNSS-PWV2 had the highest accuracy in winter, followed by spring and autumn, and the lowest in summer. The winter accuracy improvement effect of GNSS-PWV2 in temperate monsoon, temperate continental, and plateau alpine climate regions is significant, with RMSE increased by 49.84%,63.00%,and 79.43%,respectively;In the subtropical and tropical monsoon climate regions, the improvement in spring was higher, with RMSE increasing by 36.67% and 58.91%,respectively. The annual variation pattern of PWV shows a characteristic of first increasing and then decreasing, with annual PWV values fluctuating within the range of 0~80 mm.