News

New 15-minute total and diffuse downward surface shortwave flux over MSG disk

Importance of diffuse component for cloudy days
  • Aug. 3, 2020

    MDSSFTD (LSA-207) product newly offers diffuse fraction in addition to the total downward surface shortwave flux. Both are important for understanding the climate processes at the Earth-atmosphere interface, for plant photosynthesis and carbon cycle, solar power plants applications, NWP verification, nowcasting applications… Additionally to the quality flag also opacity index and aerosol load are included for each pixel.

    In Figure 1 there is an illustration of total and diffuse fluxes for selected cloudy and cloud-free days for location Ljubljana, Slovenia. Update every 15 minutes is especially important for partly cloudy days. The good correlation with ground measurements (30 minutes average) is illustrated for both cases. These satellite data are of high importance especially at the locations where there are no ground measurements.

    Figure 1: Total (dark) and diffuse (light) downward surface shortwave flux (blue) are compared with ground data (green) for the location Ljubljana, Slovenia for a cloudy day (left, 25 June 2020) and cloud - free day (right, 5 July 2020).

    Total downward surface shortwave flux is displayed in Figures 2 and 3 for the 25th of June 2020: over the area covered by MSG, at 12 UTC (Fig. 2); as an animation over Europe, between 10-14 UTC, with 15 minutes time steps (Fig. 3). 

    Figure 2: Total downward surface shortwave flux in W/m2 on 25 June 2020 at 12 UTC.

    Figure 3: Animation of total downward surface shortwave flux every 15 minutes in W/m2 from 10 – 14 UTC on 25 June 2020.

    Diffuse downward surface shortwave flux is displayed in Figures 4 and 5 for the 25th of June 2020: over the area covered by MSG, at 12 UTC (Fig. 4); as an animation over Europe, between 10-14 UTC, with 15 minutes time steps (Fig. 5):

    Figure 4: Diffuse downward surface shortwave flux in W/m2 on 25 June 2020 at 12 UTC.

    Figure 5: Animation of MDSSFTD diffuse downward surface shortwave flux every 15 minutes in W/m2 from 10 – 14 UTC on 25 June 2020.