CAMS radiation service-Analyzing the performance of standard cloud retrieval schemes

Kurzfassung

The Copernicus Atmospheric Monitoring Service (CAMS) offers solar radiation service (CRS) providing information on surface solar irradiance (SSI). The service meets the needs of European and national policy development and the requirements of partly commercial downstream services in the solar energy sector. CRS implements physical models McClear and McCloud with a fast parametrization of radiative transfer in the atmosphere as part of the Heliosat-4 scheme (Qu et al., 2017) for the clear sky and cloudy sky SSI retrieval respectively. The cloud properties are derived from images of Meteosat Second Generation (MSG) satellite instruments in their 15-minutes resolution using APOLLO-NG (Klüser et al., 2015). CRS is subject to continuous development and evolution. As a first step towards extension of the service at a global scale, currently the HIMAWARI-8/9 by Japan Meteorological Agency (JMA) is being integrated in the operational processing chain. Monitoring and evaluation of all input and output parameters is part of the regular CRS activities and ensures the service quality. Clouds are the main cause of variability and also the dominant source of errors in the all sky SSI retrieval. The focus of the presented study is the evaluation of the APOLLO-NG cloud properties, as used in the current CRS 4.5, through comparison with the CLAAS-3 (CLoud property dAtAset using SEVIRI - Edition 3) CPP (Cloud Physical Properties) database provided by CMSAF (Satellite Application Facility for Climate Monitoring) services. As Heliosat-4 offers the possibility to use cloud properties from different sources, both products are used in the Heliosat-4 to assess the suitability of existing cloud retrievals APOLLO_NG and CPP for the use in surface irradiance retrieval schemes and for all retrieval conditions as required by solar energy users. References: Klüser, L., Killius, N., Gesell, G., 2015: APOLLO_NG – a probabilistic interpretation of the APOLLO legacy for AVHRR heritage channels, Atmos. Meas. Tech., 8, 4155-4170. Qu, Z., Oumbe, A., Blanc, P., Espinar, B., Gesell, G., Gschwind, B., Klüser, L., Lefèvre, M., Saboret, L., Schroedter-Homscheidt, M., and Wald L.: Fast radiative transfer parameterisation for assessing the surface solar irradiance: The Heliosat-4 method, Meteorol. Z., 26, 33-57, doi: 10.1127/metz/2016/0781,2017. Schroedter-Homscheidt, M., Azam, F., Betcke, J., Hanrieder, N., Lefèvre, M., Saboret, L., Saint-Drenan, Y.-M.: Surface solar irradiation retrieval from MSG/SEVIRI based on APOLLO Next Generation and HELIOSAT-4 methods, Contrib. Atm. Sci./Meteorol. Z.,2022, doi:10.1127/metz/2022/1132