Relationship between sunshine duration and temperature trends across Europe since the second half of the twentieth century

Global radiation is a fundamental source of energy in the climate system. A significant impact of global radiation on temperature change is expected due to the widespread dimming/brightening phenomenon observed since the second half of the twentieth century. This work describes the analysis of 312 stations with sunshine duration (SD) series, a proxy for global radiation, and temperature series in the European Climate Assessment & Dataset (ECA&D) with data over the period 1961-2010. The relationship between SD and temperature series is analyzed for four temperature variables: maximum (Tmax), minimum (Tmin), mean temperature (Tmean), and diurnal temperature range (DTR). The analyses are performed on annual and seasonal basis. The results show strong positive correlations between SD and temperatures over Europe, with highest correlation for DTR and Tmax during the summer period. These results confirm the strong relationship between SD and temperature trends over Europe since the second half of the twentieth century. This study supports previous suggestions that dimming (brightening) has partially decreased (increased) temperatures thereby modulating the greenhouse gas induced warming rates over Europe ; The second author was supported by a postdoctoral fellowship from the “Departament d’Innovació, Universitats i Empresa de la Generalitat de Catalunya” (2011 BP-B 00078), the project NUCLIERSOL (CGL2010-18546), and the postdoctoral fellowship JCI-2012-12508