Characterization of aerosol size distributions and optical properties in the Canadian High Arctic using surface and columnar observations

This study presents long-term observations of aerosol size distributions for both coarse and fine modes as well as of aerosol light scattering and light absorption that are ongoing at the Polar Environment Atmospheric Research Laboratory (PEARL) in the Canadian High Arctic (80N, 86W). A variety of optical poperties are determined including the aerosol single scattering albedo and the scattering angstrom exponent for 405 and 870 nm as well as the black carbon concentration. The surface measurements of the aerosol scattering coefficient are also compared against the coefficient values calculated using Mie theory and the measured aerosol size distributions. The optical properties determined from the surface measurements are then compared against sun photometer measurements to understand the relationship between surface and columnar aerosol optical properties. The measurements at PEARL provide a unique combination of surface and columnar data sets on aerosols in the High Arctic, a region where such measurements are scarce despite the important impact of aerosols on the Arctic climate.