Spatiotemporal Variability of Temperature and Rainfall in Western, Central and Northern Greece During the Last 45 Years in Correlation with Frontal Activity and Convection

Abstract

A 45-year climatology of daily rainfall and temperature is retrieved from the records of HNMS, for five meteorological stations. A signal of climate change is detected in all stations, with a temperature rise and a rainfall decline. In order to study climate change from a synoptic viewpoint, frontal and weather system behaviour is studied during the course of the 45 years. The use of certain daily and monthly indices is adopted, to measure the intensity of rainfall, as well as the frontal and weather system activity/intensity. The annual cycle of these indices justifies their use. Evidence is found that frontal activity/intensity has decreased in all stations over the study period, which is associated with an, also observed, rainfall intensity decrease. It is proposed that the frontal activity has decreased due to a poleward migration of the Hadley cell, which leaves less space for weather systems to develop. This needs further investigation.