济南地区大气可降水量三种观测反演资料的对比分析

大气可降水量在研究大气辐射和吸收，以及全球的热量输送，尤其是暴雨的预报预测等方面都发挥着重要作用。应用2015年章丘站GPS/MET、微波辐射计和L波段探空3种设备反演的大气可降水量数据，比较了三者之间的偏差特征。结果表明：GPS/MET、微波辐射计和L波段探空3种设备反演的大气可降水量变化趋势一致，但也存在明显的系统偏差，量值从大到小分别是GPS/MET、微波辐射计、L波段探空。三者之间的偏差在春夏秋冬四季的差值都较为稳定；GPS/MET比微波辐射计偏大4.5 mm左右，不会因为季节的改变而明显地增大或减小。但标准差最大是夏季，其次是秋季，冬季最小。由于12：00 UTC水汽含量大于00：00 UTC，造成3种探测手段反演的大气可降水量在12：00 UTC的标准差几乎总是大于00：00 UTC，而相对偏差小于等于00：00 UTC。

A comparison of datasets of precipitable water vapor over Jinan retrieved by three kinds of equipments

Precipitable water vapor is one of the key factors in study of atmospheric radiation transfer and absorption, global wide heat transfer, and prediction of heavy rainfall. Using precipitable water vapor data in 2015 retrieved by GPS/MET, microwave radiometer and L-band sounding respectively at Zhangqiu Station, the characteristics of the 3 kinds of datasets are studied. The results show that the variation trends of the 3 kinds of datasets are similar, but with significant systematic deviations. The mean values of precipitable water vapor from big to small are retrieved by GPS/MET, microwave radiometer and L-band sounding respectively. The mean deviations among the three kinds of datasets have little changes in different seasons, while the mean deviation of dataset retrieved by GPS/MET from dataset retrieved by microwave radiometer is about 4.5 mm. However, there are significant seasonal changes in the spread of deviation, which reaches its largest value in summer, followed by autumn, spring and winter. Since atmospheric water vapor content at 12:00 UTC is greater than that at 00:00 UTC, the spread of deviation of precipitable water vapor is always larger at 12:00 UTC than that at 00:00 UTC, and the relative error at 12:00 UTC is always less than or equal to that at 00:00 UTC.