Net Radiation Estimated from the FY-2D Data over the Source Region of the Yellow River

摘要

Numerous studies have developed algorithms forestimating the net radiation by satellite remote sensing dataobtained under clear sky conditions using polar orbitingmeteorological satellite. However, estimating net radiationunder cloudy sky conditions using geostationarymeteorological satellites with remote sensing sensorsremains a significant challenge. In this paper, we developedalgorithms to estimate net radiation through the day underall cloud covered conditions using the data from the visibleand infrared spin scan radiometer, which is onboard theChinese geostationary meteorological satellite. Thegeostationary sensor can be utilized to regularly generatetemporally consistent top-of-atmosphere (TOA) and thetemperature of brightness blackbody, both at hourly scalesbecause of its frequent temporal sampling (at 1 hourinterval). Under the clear sky condition, FengYun-2D (FY-2D) data are used to derive the hourly net radiation. Forcloudy case, the transmission coefficient is calculated usingTOA reflectance and the attenuation of solar radiation inthe atmosphere. Then, amounts of solar radiation underdifferent atmospheric and cloud covered conditions arerecorded. The methodology is applied over the source of theYellow River on September 2009. Compared with groundbasedmeasurements, the root mean square errors of the netradiation estimated under clear and cloudy conditions usingthe FY-2D data are 27.0W·m-2 and 38.0W·m-2, respectively.The proposed methodology can rely exclusively on remotesensing data in the absence of ancillary ground observations;thus, it can potentially estimate the surface energy budgetregionally.