THE IMPACT OF SYNOPTIC-SCALEATMOSPHERIC CIRCULATION ON THE URBANHEAT ISLAND EFFECT OVER ATHENS, GREECE

摘要

The effect of the synoptic scale atmospheric circulation on the urban heat island phenomenon over Athens,rnGreece, was investigated and quantified for a period of two years, using a neural network approach. Arnneural network model was appropriately designed and tested for the estimation of the heat island intensityrnat twenty-three stations during the examined period. The day-by-day synoptic scale atmospheric circulationrnin the lower atmosphere for the same period was classified into eight statistically distinct categories. Thernneural network model used as an input the corresponding synoptic categories in conjunction with fourrnmeteorological parameters that are closely related to the urban heat island. It was found that the synopticrnscale circulation is a predominant input parameter, affecting considerably the heat island intensity. Also, itrnwas demonstrated that the high pressure ridge mostly favors the heat island phenomenon, while therncategories being characterised by intense northerly component winds are responsible for its non-appearancernor termination.