Characterization of surface solar-irradiance variability using cloud properties based on satellite observations

The variation in surface solar irradiance (SSI) on short timescales has been investigated previously in relation to ground-based observations. Such results are limited to the locality of the observation stations, leading to insufficient knowledge about the spatial distribution of variation features. We propose a method for characterizing variations in SSI using cloud properties obtained from satellite observations. Datasets of cloud properties from satellite observation and SSI from ground-based observation are combined at simultaneous observation points to investigate their relations. The SSI variations are classified statistically into six categories. The cloud properties related to the categorized variation features are then analyzed. From such relations, a statistical discriminant method is used to design a classifier to assign a category to the SSI variation over an area from the cloud properties obtained by satellite observation. The accuracy of classification and feature selection is discussed.