Aerosols in Arctic troposphere in spring and summer: spatial features of aerosol constituents and their mixing states

Abstract

Airborne aerosol measurements around the Svalbard Archipelago were carried out in March-April, 2000 (ASTAR 2000) and in May-June, 2004 (ASTAR 2004) for better understanding of the spatial distribution of aerosol constituents and their mixing states. Major aerosol particles were sulfate particles in both campaigns. In ASTAR 2000 (spring), acidic sulfate particles (mostly H_2SO_4 droplets) were dominant, whereas the relative abundance of neutralized sulfate particles (probably (NH_4)_2SO_4) increased in the transition period (ASTAR 2004). Under Arctic haze conditions, higher relative abundance of aerosol particles containing soot was observed. Most of the soot collected during the haze was present as "external mixing states". In contrast, soot dominantly existed as "internal mixture" with sulfate particles under the background (non-haze) conditions. In the transition period (June in ASTAR 2004), the relative abundance of aerosol particles containing soot decreased clearly. Vertical features of sea-salt modification and spatial distribution of mineral particles are also reported.