Aerosol radiative forcing over central Greenland: estimates based on field measurements

Abstract

Measurements of the key aerosol properties including light scattering and backscattering coefficients (σsp and σbsp), light absorption coefficient (σap), and particle concentration were made at Summit, Greenland, in the summer of 2011. From these quantities, the single scattering albedo (ω) and angstrom scattering and absorption exponents (åsp, åap) were calculated. In conjunction with these measurements, aerosol optical depth (AOD or τ) and the spectral surface albedo, Rs, were measured. Additionally, the aerosol chemical composition was characterized through snow and air filter analyses. A radiative transfer model was used to estimate the direct aerosol radiative forcing and radiative forcing efficiency using the measurements as inputs. Taken as a whole, this project allowed for the first ever measurement-based characterization of aerosol radiative forcing over central Greenland.