Arctic climate change and the resulting decrease in sea ice cover is expected to result in significant changes in Arctic ocean biogeochemical cycles and, consequently, surface-atmosphere exchange of greenhouse gases (carbon dioxide, methane, ozone) and other gases (dimethylsulfide) that affect the production of aerosols and formation of clouds. This can further modify Arctic climate dependent on a cascade of complex interactions and resulting feedback mechanisms involving atmospheric boundary-layer mixing, chemical processing and aerosol-cloud interactions. To assess the consequences of these changes in surface – boundary-layer exchange for Arctic climate we propose a methodology that integrates to a maximum extent MOSAiC’s experimental activities with process-based modelling studies conducted at the scale of measurements up to the Arctic region and beyond. This approach includes development and evaluation of process-based model representations of surface – boundary layer exchange of climate-active trace gases in a single-column as well as a regional atmospheric model of meteorological and chemical processes. These models will be mainly used to support analysis of the surface – boundary-layer exchange measurements collected during the MOSAiC 1-year field campaign. In addition, these models will be applied to assess the large-scale implications of these surface-boundary layer exchange processes, interactions and resulting feedback mechanisms on Arctic climate and atmospheric composition.