Solar signal on regional scale: A study of possible solar impact upon Romania's climate

Abstract

The topic of this paper is to investigate whether a solar signal can be identified in the variation of climatic parameters at regional scale. This was done using eight climate parameters recorded in Romania during 1961–2013 which corresponds with four cycles of solar activity. The methodology is based on trend, composite and wavelet analysis. A weak solar influence with a clear spatial pattern was identified, especially during the cold season, on temperature and cloud cover. During the warm season, the influence seems to be spurious. A clear difference between the north-eastern Romania and the rest of the country was found in the response of local climate to solar trigger. The mountain chain induces persistent disparities in the distribution of the most parameters, which supports the fact that orography is an important feature to be considered when analysing solar imprint at regional scale. Possible mechanisms for the solar influence on climate at regional and local scale are proposed.