A NUMERICAL-SIMULATION OF THE TRANSPORT OF SURFACE OZONE ALONG A MEDITERRANEAN COASTAL AREA

A simple numerical simulation of daily summer circulation in W-NW and E-SE directions was applied to a coastal area of Greater Ravenna in No rthern Italy to assess the influence on ozone levels of the transport mechanism in the land-sea breeze system. Field measurements of ozone c oncentration and micrometeorological data collected over a ten-year pe riod (1978-1989) by a coastal monitoring station were processed to ide ntify meteorological and climatic situations. The diurnal pattern of a ''pure'' off-shore-in-shore circulation system was reconstructed by a pplying a simple model in which data were considered or rejected as a function of the prevailing wind direction. Only data collected under W -NW and E-SE wind direction conditions became part of the reconstructe d wind circulation system. The findings show that the relative concent ration values and the time duration of the simulated transport phenome non are in good agreement with the recorded episodes of transport and of severe continuous fumigation, occurring during the night, at the po lluted area.