Modelling of surface global radiation and CIE-weighted UV-radiation for the period 1980-2000

Typ: Rapport
Serie: Meteorologi 126
Författare: Anna Jansson, Weine Josefsson
Publicerad:

Sammanfattning

This report presents the procedure for creation of surface global radiation and CIE-weighted UVradiation for the years 1980-2000. The work was ordered by the Swedish Radiation Protection Authority (SSI) on behalf of “Miljömålsrådet”. The created data covers a large geographical area over northwest Europe with a fine spatial (22x22 km) and temporal resolution (1 hour). The input data are selected from the new version of the Rossby Centre regional atmospheric climate model (RCA3), ERA-40 (www.ecmwf.int/research/era) and observations. For the creation of CIE-weighted UV-radiation, a clear sky model was first used and then a cloud modification model that reduces the clear sky radiation dependent on the cloud amount from the RCA3 model. The report also includes a validation of the modelled CIE-weighted UV-radiation against independent observations. The root mean square deviation is for daily values about 38%, for monthly values, 13% and for yearly values 7%. Also a small bias toward higher modelled UV compared to observations exists in the data set. For the creation of global radiation, the data has been selected from the RCA3 model with a correction made depended on the sun height. Also for the global radiation the validation results are presented in the report. The root mean square deviation is in the same order as for the modelled CIE-weighted UV-radiation, also here a small bias toward higher modelled values exist, but smaller then for the modelled CIE-weighted UV-radiation. All CIE-weighted UV-radiation and global radiation created in this project are freely available for non-commercial usage at the web-interface, www.smhi.se/strang/omna. Here charts, fields and time series can be selected for hourly, daily, monthly and yearly values.