Long-term Variability of Solar Radiation Derived from Satellite Data

摘要

Inter-annual variations of solar radiation may be strong and could seriously harm the return of investment for solar energy projects. This paper analyses the long-term variability of broadband surface solar radiation mainly based on 18 years of three-hourly satellite observations. Direct and global horizontal irradiance are calculated with libRadtran (library for Radiative transfer). This approach allows to use a wide range of different physical input parameters describing the composition of the actual atmosphere. Here three-hourly cloud properties are taken from the International Satellite Cloud Climatology Project (ISCCP) D1 series data set, which covers the 18-year period from July 1983 to June 2001 with a spatial resolution of 280 km. Atmospheric constituents are taken from different remote sensing and atmospheric model data sets. The detailed physical model allows the analysis of the effect of different changes within the atmosphere. The temporally strongly variable stratospheric aerosol content caused by volcanic eruptions has been included in the irradiance calculations.