STRÅNG - a solar radiation model

The STRÅNG model calculates a number of solar radiation quantities on a grid covering northern Europe.

In order to improve the knowledge of the spatial distribution of solar radiation quantities, SMHI, the Swedish Radiation Safety Authority and the Swedish Environmental Protection Agency financed a project to develop a system that could produce gridded solar radiation data. This system became known as STRÅNG.

The model grid covers the geographic area of Scandinavia and the run off region of the Baltic sea with a resolution of 11 x 11 km. A clear sky model, SMARTS2, (SMARTS2 webb site) is accompanied with a cloud effect function to compute the radiation under general atmospheric conditions.

Calculations are performed daily for the day before. Hourly, daily, monthly and yearly data and charts are available for free from 1999 and onwards. The modelled radiation quantities are as follows:

  • CIE-weighted UV radiation
  • Global radiation
  • Direct radiation
  • Sunshine duration
  • Photosynthetically active radiation

In order to perform the model calculations data from the following input sources are used:

  • Cloud and surface data from the mesoscale analysis system MESAN.
  • Precipitable water data from the NWP system HIRLAM.
  • Sea ice data from the oceanographic model HIROMB.
  • Ozone data from the ECMWF NWP model or the TOMS satellite instrument.
  • Turbidity from climatologies.