Climatology of aerosol component concentrations derived from multi-angular polarimetric POLDER-3 observations using GRASP algorithm

Abstract. The study presents a climatology of aerosol composition concentrations obtained by recently developed algorithm approach, namely the Generalized Retrieval Atmosphere and Surface Properties (GRASP)/Component. It is applied to whole archive observations from POLarization Directionality Earth's Reflectances (POLDER-3). conceptual specifics GRASP/Component approach in direct retrieval speciation (component fraction) without intermediate retrievals optical characteristics. Although global validation derived component product challenging, results are line with general knowledge about types different regions. In addition, we compare GRASP-derived black carbon (BC) dust components those Modern-Era Retrospective Analysis for Research Applications, version 2 (MERRA-2) product. Quite reasonable agreement was found between spatial temporal distribution species provided GRASP MERRA-2. differences, however, appeared regions known strong biomass burning emissions; reasons discrepancies discussed. other components, such as absorbing (BC, brown (BrC), iron-oxide content mineral dust) scattering (ammonium sulfate nitrate, organic carbon, non-absorbing aerosols, represent scarce but imperative information potential adjustment chemical transport models. properties (e.g., depth (AOD), Ångström exponent (AE), single-scattering albedo (SSA), fine- coarse-mode (AODF AND AODC)) were agree well Aerosol Robotic Network (AERONET) ground reference data, fully consistent previous Optimized, High Precision (HP) Models versions POLDER-3 data. Thus, presented extensive provides an opportunity understanding variabilities trends regional distributions species. addition additional valuable, qualitatively new insight and, therefore, demonstrates advantages multi-angular polarimetric (MAP) satellite next frontier inversion advanced observations. satellite-based dataset expected be useful improving emissions component-resolved radiative forcing estimations. products publicly available (https://www.grasp-open.com/products/, last access: 15 March 2022) used current registered under https://doi.org/10.5281/zenodo.6395384 (Li et al., 2022b).