Sunshine duration climate maps of Belgium and Luxembourg based on Meteosat and in-situ observations

Abstract. Sunshine duration was historically the traditional parameter to quantify solar radiation. In the present study, we propose to benefit from the measurements made with Campbell-Stokes recorders at 18 sites in Belgium and Luxembourg to generate maps of daily sunshine duration for the period 1995–2005. In order to provide maps with the highest degree of confidence as possible, ancillary data of high spatial resolution derived from Meteosat satellites images are used within the mapping process. Different methods combining in situ sunshine duration measurements and Meteosat-derived data are evaluated. The best performing method is then used to compile a dataset of gridded daily sunshine duration data over Belgium and Luxembourg. The 1995–2005 sunshine duration climate map is finally provided. Various areal mean values are computed and discussed.