Study of monthly mean daily diffuse and direct beam radiation estimation with MODIS atmospheric product

Reliable diffuse and direct beam radiation data are critical for many scientific researches and engineering applications. While knowledge of radiation components is not sufficient due to the cost and maintenance and calibration of the measuring equipments. Exploring novel methods for estimating radiation components have therefore considerable significance. In this paper, twenty satellite-based models for estimating radiation components were developed using MOD08-M3 atmospheric product, and evaluated using measured radiation data at 15 sites across China. The best site-specific models for diffuse and direct beam radiation were proposed, with the average RMSE of 0.642 MJ m−2 (9.299%), and 0.736 MJ m−2(10.69%), respectively. General models for radiation components were also recommended for widespread applications. The study provides a simple but efficient alternative to obtaining solar radiation components data at regional scale using MODIS satellite data. For other places of interest, the coefficients of the proposed models can be calibrated following the guidelines provided in this study with relative ease, making our models appropriate for widespread applications.