Aerosol optical properties over Svalbard: a comparison between Ny-Alesund and Hornsund

This paper presents the CAMS model based aerosol optical properties calculated for two Spitsbergen fjords, Kongsfjorden (Ny-Ålesund) and Hornsund (Polish Polar Station in Hornsund) measured between 2010 and 2015. A small decrease in Aerosol Optical Depth (AOD) is shown throughout the study period leading to an alteration of the state of the polar atmosphere. However, the potential differences observed between the stations were not statistically significant. While during the studied period no significant differences in chemical composition between the stations were observed, increasing mean values of Black Carbon (BC) were found to be associated with an increasing number of wild forest fires in remote areas producing smoke plumes, which are further transported over vast distances and reach Spitsbergen.