EGU General Assembly 2020
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the Creative Commons Attribution 4.0 License.

Global validation of satellite-based and reanalysis surface solar radiation data sets

Jörg Trentmann, Uwe Pfeifroth, Roswitha Cremer, and Martin Stengel
Jörg Trentmann et al.
  • Deutscher Wetterdienst (DWD), Offenbach, Germany (

The solar radiation reaching the Earth’s surface determines our climate and is therefore important to be monitored as consistent and complete as possible. Even though surface reference measurements of surface solar radiation are available (e.g. from the Baseline Surface Radiation Network (BSRN)), their density remains low and large areas, like the oceans, remain poorly covered. To fill the gaps in space and time, satellite-based data records (like CLARA-A2 and SARAH-2.1 from the EUMETSAT Satellite Application Facility on Climate Monitoring (CM SAF)) or model-based reanalysis data records (like ERA-5) are used. They provide surface solar radiation data with regional and global coverage, which are needed to understand its distribution and variability from the regional to the global scale.

Here we present a validation and analysis of monthly mean surface solar irradiance from multiple satellite-based and reanalysis data sets on the regional and global scale with reference to a data base of hundreds of surface measurements over land and ocean, collected from different sources (incl. BSRN, GEBA, WRDC, and buoy networks). This study provides new insights about the quality and uncertainty of available state-of-the-art satellite-based and reanalysis data records for climate studies. Regions of agreement as well as areas where the gridded data records exhibit larger differences are identified, providing important information on our current knowledge of the surface solar radiation climatology and possible improvements for future developments.

How to cite: Trentmann, J., Pfeifroth, U., Cremer, R., and Stengel, M.: Global validation of satellite-based and reanalysis surface solar radiation data sets, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-1303,, 2019

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Presentation version 1 – uploaded on 20 Apr 2020
  • CC1: Comment on EGU2020-1303, Miklos Zagoni, 21 Apr 2020

    Dear Authors, Thank you for this. Your result reinforces global surface irradiance as 7 units in my system (its theoretical value is 186.79 Wm-2 with SORCE TIM TSI = 1360.88 Wm-2). Let me note that its CERES EBAF Edition 4.1 mean value for the time period December 2000 – November 2019 (228 monthly means) is 186.75 Wm-2. -- Miklos Zagoni (EGU2020-1)

  • CC2: Comment on EGU2020-1303, Miklos Zagoni, 24 Apr 2020

    Dear Colleagues, let me add: There is also an LW flux at the integer position of -7 units (again, -186.79 W/m2 with TSI = 51 units = 1360.88 W/m2), namely Atmospheric LW Net (called also Atmosphere LW Cooling). As there is no direct theoretical connection between global surface solar irradiance and atmospheric LW cooling, their accurate equality in the N-position suggests fundamental physical laws in the background. Notice that the CERES EBAF Ed4.1 value (19-year mean) for Atm LW net is -186.70 W/m2; a difference of only 0.09 Wm-2 to the N-position. Your accurate estimate of global surface irradiance is very important in establishing the whole structure. - Thank you. Miklos Zagoni (EGU2020-1)

    • AC1: Reply to CC2, Uwe Pfeifroth, 13 May 2020

      Dear Miklos Zagoni,

      Thank you for your interest in our study. We agree that there are still plenty of things one can learn from general global data based studies. Thank for your insight on the numbers. We will get more precise information and conclusions as the data records are improving - which we are also working on. Hope to meet you one day on physical conference.