Effects of Atmosphere on Radiative Transfer Characteristics and Salinity Retrieval on Spaceborne Salinity Meter

WANG Yingqiang1,†, YAN Wei1, WANG Yeying2, HAN Yueqi1

1. College of Meteorology and Oceanology, National University of Defense Technology, Nanjing 211101; 2. 32021 PLA Troops, Beijing 100094; † E-mail: wyqiang198253@163.com

Abstract Using the MPM93 model, the L-band of atmospheric radiation parameters and salinity meter observation brightness temperature under different weather conditions are numerically simulated based on the microwave radiation transfer equation, and using the maximum likelihood estimation algorithm to the inversion of sea surface salinity, which research the influence of different weather conditions on the sea surface salinity retrieval value. The simulation results show that the atmospheric radiation parameters of cloud, fog and haze which considered the effects of suspended droplets are almost the same as those in clear sky, and the influence of them can be neglected. However, the influence of rainfall on atmospheric radiation parameters can’t be neglected, and the error of salinity retrieval increases obviously with the increase of rainfall rate. When the rainfall rate is fixed, the salinity inversion error decreases with the increase of sea surface temperature, and the salinity retrieval error is smaller under low salinity value. Besides, the salinity retrieval error changes decrease after increasing with the increase of sea level atmosphere temperature. Furthermore, the influence of sea surface windspeed, sea level pressure and sea level vapor density on salinity retrieval error are very small. Key words sea surface salinity; L-band; atmospheric radiation transfer; salinity retrieval

在海洋‒海表面盐度是海洋学和气候学的重要参数, 是全球水循环和海洋环流的重要影响因素,大气这一复杂系统中发挥着极其重要的作用。在全

球天气分析和气候预报模式中, 海表面盐度是必不可少的初始场资料[1]。目前, 对海表面盐度遥感使用的波段已经有比较统一的认识, 即选择以1.413