Development of a Surface Radiation Product Using Himawari-8 at JMA

Solar radiation at surface has been observed since 1931 at the Japan Meteorological Agency (JMA). The observed solar radiation is utilized in various fields such as renewable energy, agriculture and climate research. However, JMA observations for the solar radiation are currently limited in the local meteorological observatories. For wider spatial-temporal coverage, the Meteorological Satellite Center (MSC) of JMA is developing a product to retrieve the solar radiation at surface from Himawari-8.

MSC/JMA has developed a method to estimate solar flux at surface using cloud and aerosol properties from Himawari-8 observation. The cloud optical properties (e.g. cloud optical depth and effective radius) are derived by the Optimal Cloud Analysis (OCA) product introduced from EUMETSAT, and the aerosol optical properties (e.g. aerosol optical depth and fine-mode weight) are from an aerosol product developed by the Meteorological Research Institute (MRI) of JMA. The amount of water vapor and ozone which is important for the attenuation of solar radiation is obtained from JMA’s numerical prediction models. Using these quantities, the direct, diffuse and global solar radiation at surface can be estimated by a fast radiative transfer computation which covers the entire solar spectrum.

This presentation provides details of the estimation method for solar flux at surface, validation results with surface observations (e.g. pyranometer operated by JMA) and sensitivity study for the optical properties derived from Himawari-8 (e.g. ice crystal habits dependency).