Estimation of ground albedo by GMS images for solar irradiation monitoring

Abstract Recently, the utilization of cloud images obtained by Geostationary Meteorological Satellite (GMS) has been proposed by several organizations for solar irradiation monitoring [1,2]. In order to exactly estimate the irradiation at ground-level by the images, it must be noted that the images are affected by seasonal and local variations, especially caused by ground albedo. Nowadays, the computations of the albedo are performed by using a time series of the images. Example maps of the albedo are also given for each season. In addition, a new rule of estimating the irradiation by using the albedo is proposed. Using this new method, the annual- and seasonal-integrated global irradiation can be estimated with good accuracy in spite of ground conditions.