Chemically resolved submicrometric size distribution and external mixing of the Arctic haze aerosols

Abstract

Atmospheric aerosol particles were collected with filter and impactor samplers at Ny‐Ålesund, Spitzbergen during an Arctic haze event in the Spring of 1983. Additional integral aerosol parameters particle light scattering coefficient and total number concentration were also measured. The samples were analyzed for mass, elemental and soot content. With the exception of chlorine that was due to local marine sources, concentrations of the chemical species were all highly correlated with each other and with total mass concentration, light scattering and total number concentration. Mass concentration varied between 4 and 12 μg m−3; other species showed values within the range reported previously under similar conditions. The impactor and total number concentration data were inverted to yield size distributions for the size range 0.01 to 1.0 μm radius. The mode of the total and elemental mass size distributions was in the range 0.13 to 0.26 μm with the exception of soot, which had a mode at slightly less than 0.13 μm. The main mass of the particulate material had hygroscopic properties similar to that previously observed for urban or continental aerosols. However, soot was observed to be associated with particles that were hygrophobic and it was concluded that it was externally mixed. Overall, the aerosol had properties indicative of one that had remained relatively unchanged after transport from its source region. 1987 Blackwell Munksgaard