由 张 良承 First PWV Retrieval Using MERSI-LL Onboard FY-3E and Cross Validation With Co-Platform Occultation and Ground GNSS
基于风云三号E星MERSI-LL的首次大气可降水量反演及同平台掩星与地基GNSS交叉验证
引文格式 | Citation:
Jiang N, Wu Y H, Li S, Xu Y, Wang Y B, Xu T H. First PWV retrieval using MERSI-LL onboard FY-3E and cross validation with co-platform occultation and ground GNSS[J]. Geophysical Research Letters, 2024, 51(8): e2024GL108681. DOI: 10.1029/2024GL108681.
Geophysical Research Letters（中科院1区Top，IF：4.6）
First time to retrieve Precipitable water vapor (PWV) with FY-3E MERSI-LL data under all weather conditions
Retrieval accuracy was cross-validated both with co-platform occultation and ground GNSS
Random Forest (RF) method with the advantage of high accuracy and stability was applied to retrieve PWV
Retrieval accuracy was cross-validated both with co-platform occultation and ground GNSS
Random Forest (RF) method with the advantage of high accuracy and stability was applied to retrieve PWV
Abstract | 摘要
FY-3E plays a vital role in the meteorological global earth observing system. Precipitable water vapor (PWV) is an essential parameter for the water cycle and global climate change. Here, we carry out the PWV retrieval using the MERSI-LL sensor onboard the FY-3E satellite for the first time. The retrieval accuracy under different cloudage conditions is validated by the extra PWV from ground-based GNSS and spaceborne occultation. For the results against ground-based GNSS, the total accuracy shows an RMSE of 2.69–3.36 mm as the clouds increase, and correlation coefficients higher than 0.95. The spatial accuracy distribution indicates that inland stations have higher accuracy than the coast and island stations. As for the results against spaceborne occultation, the verification accuracy varies with the spatial pairing distance, showing poor accuracy in the low latitude area. This study can provide an essential reference for the community to understand the current water vapor inversion performance of MERSI-LL.
风云三号E星（FY-3E）在全球气象地球观测系统中发挥着重要作用。作为水循环和全球气候变化研究的关键参数，大气可降水量（PWV）的精确监测具有重要意义。本研究首次利用FY-3E卫星搭载的中分辨率光谱成像仪-微光型（MERSI-LL）开展PWV反演研究，并联合地基GNSS与星载掩星观测数据，系统评估了不同云量条件下MERSI-LL的PWV反演精度。与地基GNSS的对比结果表明：随着云量增加，PWV反演的总体均方根误差为2.69-3.36毫米，相关系数始终保持在0.95以上；空间精度分布显示，内陆站点的反演精度明显优于沿海和岛屿站点。与星载掩星数据的对比发现：验证精度随空间匹配距离的增大而降低，低纬度地区的反演精度相对较差。本研究为学术界深入了解MERSI-LL的水汽反演性能提供了重要参考。