Extensive validation of CM SAF surface radiation products over Europe
journal contributionposted on 20.09.2017 by Ruben Urraca, Ana M. Gracia-Amillo, Elena Koumpli, Thomas Huld, Jorg Trentmann, Aku Riihela, Anders V. Lindfors, Diane Palmer, Ralph Gottschalg, Fernando Antonanzas-Torres
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This work presents a validation of three satellite-based radiation products over an extensive network of 313 pyranometers across Europe, from 2005 to 2015. The products used have been developed by the Satellite Application Facility on Climate Monitoring (CM SAF) and are one geostationary climate dataset (SARAH-JRC), one polar-orbiting climate dataset (CLARA-A2) and one geostationary operational product. Further, the ERA-Interim reanalysis is also included in the comparison. The main objective is to determine the quality level of the daily means of CM SAF datasets, identifying their limitations, as well as analyzing the different factors that can interfere in the adequate validation of the products. The quality of the pyranometer was the most critical source of uncertainty identified. In this respect, the use of records from Second Class pyranometers and silicon-based photodiodes increased the absolute error and the bias, as well as the dispersion of both metrics, preventing an adequate validation of the daily means. The best spatial estimates for the three datasets were obtained in Central Europe with a Mean Absolute Deviation (MAD) within 8–13 W/m 2 , whereas the MAD always increased at high-latitudes, snow-covered surfaces, high mountain ranges and coastal areas. Overall, the SARAH-JRC's accuracy was demonstrated over a dense network of stations making it the most consistent dataset for climate monitoring applications. The operational dataset was comparable to SARAH-JRC in Central Europe, but lacked of the temporal stability of climate datasets, while CLARA-A2 did not achieve the same level of accuracy despite predictions obtained showed high uniformity with a small negative bias. The ERA-Interim reanalysis shows the by-far largest deviations from the surface reference measurements.
R. Urraca is funded by the fellowship FPI-UR-2014 granted by the University of La Rioja. E. Koubli has been partially funded by the EMRP ENG55 project “Towards an energy-based parameter for photovoltaic classification”. The EMRP is jointly funded by the EMRP participating countries within EURAMET and the European Union. A. V. Lindfors and A. Riihela were supported by the Academy of Finland, decision 284536.
- Mechanical, Electrical and Manufacturing Engineering