A new seasons definition based on classified daily synoptic systems: An example for the eastern Mediterranean

A new definition for seasons based on a synoptic classification is introduced. It uses the automatically classified daily synoptic systems. For the eastern Mediterranean (EM), the temporal distribution of the synoptic systems over 53 years enables a proper definition of the timing and duration of the cold rainy, warm dry and of the transition seasons. Comparisons with the astronomical, meteorological and the temperature-based seasons definitions following Trenberth is performed. According to the synoptic definition proposed here and applied to the EM, the winter and summer seasons each last about 4 months (3 months and 23 days). The EM 'synoptic summer' and 'synoptic winter' defined here begin at about the earliest starting date, i.e. the meteorological start, and they end at about the latest ending date, i.e. the astronomical end.