Winter atmospheric circulation patterns and their relationship with the meteorological conditions in Greece

This study presents an analysis of the relationship between winter large-scale circulation and surface meteorological conditions over Greece for the period 1979-2009. The adopted methodology involves the application of an automated atmospheric circulation classification scheme based on the self-organizing map approach. The impact of each of the identified relevant 19 winter atmospheric circulation patterns on local meteorological condition is examined at seven sites by calculating the corresponding differences from the mean meteorological conditions. The conditional transition probabilities of circulation patterns indicate the existence of increased 1-day persistence, especially for the anticyclonic and the pattern related to Genoa depressions. Positive temperature anomalies are observed for the cyclonic patterns, while negative anomalies are attributed to the effect of anticyclonic circulation. © 2014 Springer-Verlag Wien.