Concentrations and fluxes of aerosol particles during the LAPBIAT measurement campaign at Värriö field station

[摘要] The LAPBIAT measurement campaign took place in the VärriöSMEAR I measurement station located in Eastern Lapland in the springof 2003 between 26 April and 11 May. In this paper we describe themeasurement campaign, concentrations and fluxes of aerosolparticles, air ions and trace gases, paying special attention to anaerosol particle formation event broken by a air mass change from aclean Arctic air mass with new particle formation to polluted oneapproaching from industrial areas of Kola Peninsula, Russia, lackingnew particle formation. Aerosol particle number flux measurementsshow strong downward fluxes during that time. Concentrations ofcoarse aerosol particles were high for 1–2 days before thenucleation event (i.e. 28–29 April), very low immediately beforeand during the observed aerosol particle formation event (30 April)and increased moderately from the moment of sudden break of theevent. In general particle deposition measurements based on snowsamples show the same changes. Measurements of the mobilitydistribution of air ions showed elevated concentrations ofintermediate air ions during the particle formation event. Weestimated the growth rates in the nucleation mode size range. Forparticles <10 nm, the growth rate increases with size on 30April. Dispersion modelling made with model SILAM support theconclusion that the nucleation event was interrupted by an outbreakof sulphate-rich air mass in the evening of 30 April that originatedfrom the industry at Kola Peninsula, Russia. The results of thiscampaign highlight the need for detailed research in atmospherictransport of air constituents for understanding the aerosoldynamics.

[学科分类] 大气科学