Abstract
The main objective of this study is to analyze downward shortwave radiation estimated from geostationary satellite by using an index called Clear Sky Rate (CSR) and apply it to see the impact of geographical and land use variation on clouds. Matsuyama, the target area in this study has mountains, plains and contrasting land uses of urban and rural areas. The following outcomes were obtained. CSR is likely to be lower in mountainous areas than in the plain areas. The temporal analysis shows that the CSR on the mountains decreases down to the midday and then increases accordingly with time compared to the plain areas. The comparison between urban and rural areas shows that formation and thickness of cloud in an urban area are higher than the rural area in the afternoon. The CRS index and the dataset has a high potential to understand the local cloud properties.
