Satellite Application Facilities irradiance products: hourly time step comparison and validation over Europe

Downward long and short wave incoming irradiances play a key role in the radiation budget at the earth surface. The monitoring of those parameters is essential for the understanding of the basic mechanisms involved in climate change, such as the greenhouse effect, the global dimming, the change in cloud cover and precipitations, etc. The use of geostationary satellite observations becomes crucial, since they allow the retrieval of irradiance at the surface, with the best spatial and temporal coverage. Three of Eumetsat decentralized Satellite Application Facilities (SAFs) are retrieving on an operational basis the surface solar and the downward long wave radiation from Meteosat images. This study presents a common validation of these SAFs radiation products against ground data from 8 stations covering four months representative of the annual declination variation. The overall conclusion is that the products of the different facilities are comparable in terms of bias and standard deviation. The surface solar irradiance is retrieved with a standard deviation of 80-100 (W m-2) and negligible bias, and the downward long wave irradiance with a standard deviation of 25 (W m-2) with a slight site-dependent bias