Surface Solar Radiation based on Satellite Observations – the new CM SAF SARAH-3 Climate Data Record

The EUMETSAT Satellite Application Facility on Climate Monitoring (CM SAF) generates and distributes high quality long-term climate data records (CDR) of energy and water cycle parameters, which are freely available.

In 2023, finally the new edition of the “Surface Solar Radiation data set – Heliosat” has been released: SARAH-3. As the previous editions, the SARAH-3 climate data record is based on satellite observations from the first and second METEOSAT generations and provides various surface radiation parameters, including global radiation, direct radiation, sunshine duration, photosynthetic active radiation and others. The SARAH-3 climate data records are accompanied by a corresponding near-realtime processing (so-called interim climate data records). With that, SARAH-3 covers the time period since 1983 with a timeliness of 1 day and offers 30-minute instantaneous data as well as daily and monthly means on a regular 0.05° x 0.05° lon/ lat grid. Compared to previous versions, the data quality of SARAH-3 has been substantially improved over snow-covered surfaces, e.g, in the Alpine region, by the use of an internally derived snow information. SARAH-3 enables a wide range of applications – from model verification and renewable energy assessments to operational climate monitoring.

In this presentation, an overview of the SARAH climate data record and example applications will be given. After presenting the SARAH-3 developments and validation results, SARAH-3 will be used for the analysis of climate variability and potential trends in Europe during the last decades. The data record reveals that there is a positive trend of surface solar radiation in Europe during the last decades, which is superimposed by decadal and regional variability.