Nucleation in the Karlsruhe plume during the COPS/TRACKS-Lagrange experiment

摘要

A plume of ultrafine particles was observed downwind of the Karlsruhe city and industrial area during the COPS; TRACKS Lagrangian airborne experiment in summer 2007. These ultrafine particles were identified as nucleation-generated aerosols from emissions of a coal-fired power plant and an adjacent refinery, the two main emitters of sulphur dioxide in the area. Modelling the production and growth of aerosols with the COSMO-ART model required, in agreement with the known emission sources, a strong elevated source of sulphur dioxide to explain the temporal evolution of the particle plume. The power plant at Karlsruhe Rheinhafen emits from a 233 m high chimney. The ultrafine particles produced from these fossil-fuel-related sources were the dominant fraction of all ultrafine particles in the rural area of the Kraichgau downwind of Karlsruhe, exceeding all other anthropogenic sources and are suspected of being the major contribution to the number of cloud condensation nuclei (CCN) on a regional scale.Compared to previous investigations on the sulphur chemistry in power-plant plumes, emissions from this power plant, which is equipped with modern stack-gas cleaning technology, had a higher yield of nucleation-mode aerosols as CCN precursors per emittedsulphur dioxide mass.