阳江国际探空试验的GPS、探空、微波辐射计水汽资料对比分析

GPS/MET水汽资料因其建设维护成本低、时间分辨率高、可全天候、无人、自动观测等优点,已经成为获取大气水汽资料新的重要手段。以阳江第八届国际探空比对试验资料为基础,对比分析了GPS/MET与4种探空仪和微波辐射计获取的水汽资料。探空与GPS/MET测量的水汽值有较强的相关性,相关系数在0.57~0.74之间,但探空水汽值比GPS/MET偏高0.71~1.47mm,方差在3.48~3.96之间。其中RS92探空仪测量的水汽变幅与GPS/MET基本相当,但国内探空仪水汽测量值的变幅明显高于GPS/MET,偏高近1.6~1.8倍。微波辐射计在天气较好时,测量精度较高,基本上以3个国产探空仪数据相当;但微波辐射计在雨天受罩子上的雨水影响,误差较大,与GPS/MET的测量值不相关。

A Comparative Analysis of Vapor Data between GPS/MET, Radiosonde and Microwave Radiometer from Yangjiang International Radiosonde Intercomparison

Based on the GPS/MET water vapor data, a comparative analysis of the GPS/MET vapor and four kinds radiosonde results calculated by using the regression method is conducted, and it is found that the radiosonde measurements of water vapor are generally 0.71 to 1.47 mm higher than those of GPS/ MET, with the variance between 3.48 and 3.96, and the correlation coefficients are between 0.57 and 0.74. The variation amplitudes of RS92 radiosonde measurements of moisture are basically close to those of GPS/MET moisture, but the variation amplitudes of domestic sonde moisture measurements are obviously higher than those of GPS/MET by a factor of nearly 2.6 to 2.8. The microwave radiometer measurements of moisture are 16.12 mm higher than those of GPS/MET averagely. The analysis indicates that the measurements of microwave radiometers are obviously influenced by the revised models with different area corrections. Through the localization of the revised model, the abnormal high measurements of microwave radiometers are corrected, only 3 to 5 mm higher.