Analysis of multi-year, fine and coarse mode aerosol optical depth, particle size and refractive index retrievals from ground-based sunphotometry / sky radiometry data acquired in the western Arctic

It is known that the optical properties of aerosols change with particle size and particle nature. Fine and coarse mode (sub and super micron) aerosol optical depth (AOD), average particle size, particle size distribution width, and refractive index are fundamental and robust aerosol parameters that, along with particle shape determine all 1^st and 2^nd order aerosol properties. Their estimation, using both measurement and models, is important towards understanding their scattering and absorption influence as well as in helping to discriminate aerosol species. This knowledge has important radiative forcing and climate change applications particularly in the climate-sensitive Arctic region where our research project is based. We analyzed multi-year (2006 – 2016), fine and coarse mode AOD, effective radius, particle size distribution width and refractive index retrievals acquired during the polar summer and polar winter seasons over a number of AEROCAN / AERONET sites in the North American and European Arctic. We will present retrieval sensitivity studies which will include an analysis of the impact of optical coupling between these robust aerosol parameters.