Research progresses in parameterization schemes for estimating downward shortwave and longwave radiations are reviewed by use of satellite data and ground-based routine observations in recent years. Based on a comprehensive analysis of the relevant literatures, the theoretical backgrounds of downward shortwave and longwave radiation parameterization schemes are described. According to the clear-sky and cloudy-sky conditions, the radiation parameterization schemes are summarized and their advantages and disadvantages in the practical application are reviewed. Under clear-sky conditions, the main parameterization schemes of downward shortwave radiation are statistical methods and radiative transfer models; the longwave radiation parameterization schemes are mainly single-parameter and dual-parameter methodologies. Under cloudy-sky conditions, radiation parameterization schemes are mainly limited to the determination of cloudiness. The limitations of estimating downward shortwave and longwave radiation on the surface are the selections of appropriate parameterization scheme that need considering land cover types and the attainment of meteorological observations and satellite remote sensing data. In the future, the relatively promising estimation approach is pointed out by combination of polar-orbiting and geostationary satellite remote sensing data.

In order to study the distribution of latent heat flux in Northern China, a scheme, eliminating the need of ground meteorology data as input and only using remotely sensed information, is proposed to estimate latent heat flux over semiarid areas for clear sky days. In this scheme, latent heat flux is calculated based on surface energy balance: net radiation is estimated using an improved parameterization; soil heat flux is calculated through a regression equation; evaporative ratio is obtained by S-SEBI model. Based on land and atmospheric data products available from moderate resolution imaging spectroradiometer (MODIS), this scheme is validated by clear sky datasets at the degraded grassland site and the farmland site during June to November in 2003, 2004 and 2005. The results indicate that the proposed scheme can effectively calculate the latent heat flux. The root mean square error (RMSE) for the estimated latent heat flux in grassland and farmland are 60.4 and 64.6 W/m² respectively, and the mean error (ME) are 18.6 and 32.4 W/m² respectively.

In order to monitor the range and extent of drought and resolve the serious problems of the semi-arid regions, a soil moisture retrieval method by satellite microwave remote sensing is proposed. The relation of microwave brightness temperature and surface soil moisture was simulated by surface and atmosphere microwave radiative transfer models. The soil moisture retrieval algorithm in the logarithm-cubic form was established. By using the data of the microwave radiation imager aboard the FY-3A polar orbiting meteorological satellite and the retrieval algorithm, the soil moisture was derived for the farmland and the grassland in Tongyu of Jilin. The result shows that the retrieval soil moisture is in good agreement with the ground-based observations. The root mean square error is 0.003 cm³/cm³ for the farmland, and 0.005 cm³/cm³ for grassland. The method can be applied to the future FY-3B satellite that is possible to derive more information. With the improved radiation transfer model in the future, the radiation characteristics of the various grounds will be obtained. The regional moisture study will be carried on in the future.