Investigating sunshine duration patterns in the central Mediterranean

Abstract

Sunshine duration is the interval period in hours when beam insolation is over 120W/m2. Some parameters that affect sunshine duration include cloud cover, cloud type, cloud altitude, aerosols, wind speed and direction, air temperature, relative humidity, vapour pressure, precipitation, latitude, season and time of the day. Studies on sunshine duration in the central Mediterranean are limited and were mostly done in Europe and China.

The essential purpose of this research is to examine sunshine duration patterns in the central Mediterranean area from the interval of January 2013 – December 2018 in order to improve the understanding of recent sunshine duration data. The information utilised in this research is from the CLIMAT report format and was obtained from the websites of Ogimet, Deutscher Wetterdienst Climate Data Centre, NASA Terra MODIS and Time and Date.

The southern Mediterranean locations generally had a higher sunshine duration than the northern locations. Sunshine duration was highest in Gafsa and lowest in Messina. The sunshine duration trends were significant in all locations. The sunshine duration trends were positive at Messina and Trapani while the locations of Luqa, Tunis, Jendouba, Kairouan and Gafsa had negative sunshine duration trends. The results also show a dependence between sunshine duration and the physical parameters studied except wind direction. Maximum sunshine duration was in summer and minimum sunshine duration was in winter. The linear regression model produced by this study was significant so it significantly modelled sunshine duration according to the variations of the parameters.