Aerosol components derived from global AERONET measurements by GRASP: A new value-added aerosol component global dataset and its application

Aerosols affect the Earth’s climate both directly and indirectly, which is the largest uncertainty in the assessment of radiative forcings affecting anthropogenic climate change. The standard AErosol RObotic NETwork (AERONET) aerosol products have been widely used for more than thirty years. Currently, there is strong community interest in the possibility of determining aerosol composition directly from remote sensing observations. This work presents the results of applying such a recently developed approach by Li et al. (2019) to extended data sets of the directional sky radiances and spectral aerosol optical depth (AOD) measured by AERONET for the retrievals of aerosol components. First, the validation of aerosol optical properties retrieved by this component approach with AERONET standard products shows good agreement. Then, spatio-temporal variations of obtained aerosol component concentration are characterized globally, especially the absorbing aerosol species (black carbon, brown carbon and iron oxides) and scattering aerosol species (organic carbon, quartz, and inorganic salts). Finally, we compared the black carbon (BC) and dust column concentration retrievals to the Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2) products in several regions of interest (Amazon zone, Indo-China Peninsula, North India, Southern Africa, Sub-Sahel, Gobi Desert, Middle East, Sahara Desert, Taklamakan Desert) for new insights on the quantitative assessment of MERRA-2 aerosol composition products (R = 0.60 ~ 0.85 for BC; R = 0.75 ~ 0.90 for dust). The new value-added and long-term aerosol composition product globally is available at https://doi.org/10.6084/m9.figshare.25415239.v1, which provide important measurements for the improvement and optimization of aerosol modelling to enhanced estimate the aerosol radiative forcing.