Concentration profiles of hydrocarbons during episodes in relation to emission pattern, model calculations and oxidants

Abstract

Since 1989 precursors and reaction products involved in tropospheric oxidant formation have been monitored continuously at the Swedish west coast (Rorvik) as part of the EUROTRAC-TOR project. During the spring 1990 two periods with enhanced concentrations of air pollutants in the boundary layer were observed, one in the middle of March (17th–19th) and the other in late April (23rd–27th). In this paper the episodes are described and discussed in relation to the formation of oxidants during long range transport. For the March episode the concentrations of oxidants and precursors were calculated by a photochemical trajectory model for air parcels transported from continental Europe to Rorvik. The predictions from the model are discussed in relation to the concentrations measured.