An algorithm for estimating downward shortwave radiation from GMS 5 visible imagery and its evaluation over China

Abstract

[1] This paper presents an operational scheme to estimate downward shortwave radiation (DSR) over China from the visible-band top-of-atmosphere reflectance of the Geostationary Meteorological Satellite (GMS) 5 imagery. The proposed algorithm retrieves surface reflectance and atmospheric parameters directly from GMS 5 images by searching lookup tables, which are created by the radiative transfer model SBDART and consider the effects of water vapor absorption and surface altitude variations. Experiments show that the DSR retrieval is more sensitive to the selection of aerosol type and less to that of the cloud type. Uncertainty in the reflectance of a bright surface leads to a considerable DSR retrieval error (±(6-9%)). The instantaneous retrieved DSR is evaluated by field measurements on the Tibetan Plateau, and the daily retrieved DSR is compared with one year's ground-based measurements at 96 stations in China. The results show that the estimated DSR is in good agreement with ground measurements with a correlation coefficient of ∼0.9 and a bias of 1.5%. Root-mean square differences in the daily DSR are 17.7% for all-sky and 13.1% for clear-sky conditions. These results suggest that the proposed method applied to the GMS 5 satellite data can accurately estimate temporally and spatially continuous instantaneous and daily DSR. These DSR data sets will be useful for a wide range of applications.Citation: Lu, N., R. Liu, J. Liu, and S. Liang (2010), An algorithm for estimating downward shortwave radiation from GMS 5 visible imagery and its evaluation over China,

A long-term Global LAnd Surface Satellite (GLASS) data-set for environmental studies

“…For the insolation estimation from GMS-5 data (Lu et al 2010), the RMSE and bias of hourly estimates is 76.6 W m (2 and 8 W m (2 , respectively. The daily estimates have an average RMSE of 29.16 W m (2 (17.7%) under all-sky conditions, which is relatively comparable to the results of other studies on using GMS-5 (Tanahashi et al 2001;Kawai and Kawamura 2005) The GLASS insolation algorithm is almost identical to that discussed in Section 4.2 with a few differences, and the preliminary validation results are very encouraging.…”

“…This algorithm has been extended to estimate PAR from GOES data (Zheng, Liang, and Wang 2008) by taking into account topographic effects. The algorithm was also extended to estimate insolation over China from imagery of Geostationary Meteorological Satellite (GMS) 5 by considering water vapor and the surface elevation (Lu et al 2010). Huang et al (2011) further extended the LUT scheme to estimate insolation by combining the Multifunctional Transport Satellite (MTSAT) data and MODIS data products.…”

Estimating global solar radiation using a hybrid parametric model from MODIS data over the Tibetan Plateau

“…The retrieved COT of MODIS has been validated by many studies (Houborg et al, 2007;Lu et al, 2010). Cirrus clouds cannot always be detected because of the poor cirrus detection capabilities of the MODIS cloud-detection algorithm (http://modis-atmos.gsfc.…”

“…Using MTSAT images, Lu et al (2011) obtained a RMSE of Tibet of 17.25% during the winter and 15.64% during the summer (Lu et al, 2011) using hourly MTSAT images and an ANN model. Using the same input and LUT method, Lu also estimated the DSSR with a RMSE of 17.7% at 96 stations from January to December 2000 in China (Lu et al, 2010) but he did not report the model performance in the TP. Kawai and Kawamura validated the DSSR using GMS-5/VISSR channels with 19.5% RMS errors (Kawai and Kawamura, 2005).…”

“…SBDART combines the sophisticated discrete ordinate radiative transfer module, low-resolution atmospheric transmission model, and Mie scattering for light scattering by water droplets and ice crystals. A series of sensitivity studies of SBDART were discussed by Lu et al (2010). The experiments demonstrate that total downward shortwave flux largely depends on the COT, and the cloud droplet effective radius, the cloud height, and different aerosol types do not significantly affect DSSR under cloudy sky.…”