Continuous atmospheric measurements of peroxyacetyl nitrate (Pan) in a Mediterranean site (Athens, greece)

Photochemical pollution episodes are becoming an important problem for many major Mediterranean cities with a hot, sunny climate. Peroxyacetyl nitrate (PAN) can serve as a very good tracer of photochemical activity in the atmosphere, and was measured automatically for the first time in Athens, Greece, during the period 18 September‐10 October 1985. The observed overall PAN concentrations were generally lower than expected for a city with frequent formation of photochemical smog. It appears, however, that elevated PAN and ozone concentrations occur mainly by sea‐breeze circulation, which is often observed at coastal sites.