New developments on SPEXone aerosol products on the NASA PACE mission

We present the latest developments in SPEXone aerosol products. Firstly, the RemoTAP-Hybrid algorithm is developed, combining Multiple Collaborated Neural Networks (MCNN) with a full physics inversion. RemoTAP-Hybrid improves SPEXone global aerosol retrievals regarding accuracy and speed. Secondly, following an analysis on AERONET data, we extend the aerosol description to a parametric 4 mode by adding a fine non-spherical mode, in addition to a fine spherical, coarse non-spherical, and coarse spherical mode. The new aerosol description extends retrieval capability for scenes dominated with non-spherical fine particles. Thirdly, higher level products are developed for aerosol composition (black carbon, brown carbon, dust, fine/coarse water/non-absorbing components, fine non-spherical non-absorbing component) based on the retrieved complex refractive index and aerosol volume per mode. We will present the global and seasonal distribution of chemical composition and aerosol microphysics retrieved from SPEXone.

We validate the retrieved aerosol properties with AERONET data for AOD, Angstrom Exponent, absorption AOD, and SSA, showing unprecedented accuracy. The RMSE for AOD is 0.051 (0.037) over land (ocean), and 78.3% (80.8%) of the AOD retrievals are within the Global Climate Observing System (GCOS) requirement. The RMSE for Angstrom Exponent is 0.186 (0.207), for absorption AOD is 0.023 (0.014), and for SSA is 0.038 (0.044) over land (ocean). Finally, we present our latest results on aerosol retrievals above cloud from SPEXone.