MERGE SP: Fog at Swedish airports – is it changing and why?

We will analyse visibility data from 13 Swedish airports with long enough time series to be included in the study (Malmö, Stockholm, Gothenburg, Östersund, Visby, Kiruna) and investigate if the occurrence of fog has changed over the last 50 years. We have analyzed visibility, temperature, wind and pressure data and have also included SO2 measurements in the air and SO4 in rainwater to estimate aerosol concentrations in the air during same time intervals. Also SO2 emission data for Europe has been analyzed in this investigation. We will try to determine the cause of such possible changes by comparing the visibility data to emission data of sulphur dioxide and to measurements of air temperature at the stations.