Climate and environmental conditions in the polar regions are undergoing drastic changes. Recent in situ and space-borne measurements revealed frequent Arctic haze formation from local sources (e.g., shipping, wild fires, industrial activities, and residential combustion) or transported from mid-latitude regions, which calls for a quantitative assessment of impacts of anthropogenic aerosols on the Arctic atmosphere and cryosphere. Meanwhile, natural aerosols from marine biosphere, biomass smoke, and volcano are also closely linked to the polar cloud and climate changes. This session solicits papers addressing observations and modeling of sources and transport of aerosols in the high latitudes, aerosol effects on the mixed phase and ice clouds, aerosol snow-albedo effects, cloud–radiation–sea ice interactions, the role of aerosols in the sea ice and land ice melting, etc.