Estimating aerosol emission from SPEXone on the NASA PACE mission using an ensemble Kalman smoother: observing system simulation experiments (OSSEs)

Abstract. We present a top-down approach for aerosol emission estimation from Spectropolarimeter Planetary Exploration (SPEXone) polarimetric retrievals related to the amount, size, and absorption using fixed-lag ensemble Kalman smoother (LETKS) in combination with ECHAM-HAM model. assess system by performing observing simulation experiments (OSSEs) order evaluate ability of future multi-angle polarimeter instrument, SPEXone, as well satellite near-perfect global coverage. In our OSSEs, nature run (NAT) is climate model altered emissions. The control (CTL) data assimilation (DAS) are composed an simulations, where default emissions perturbed factors taken Gaussian distribution. Synthetic observations, specifically optical depth at 550 nm (AOD550), Ångström exponent 865 (AE550–865), single-scattering albedo (SSA550) assimilated estimate fluxes desert dust (DU), sea salt (SS), organic carbon (OC), black (BC), sulfate (SO4), along two SO4 precursor gases (SO2, DMS). prior relative mean absolute error (MAE) before ranges 33 % 117 %. Depending on species, observations sampled coverage reduce this equal or lower than 5 Despite its limited coverage, SPEXone sampling shows similar results, somewhat larger errors DU SS (both having MAE 11 %). Further, show that doubling measurement increases up 22 SS. addition, results reveal when wind DAS uses different reanalysis dataset (ERA5 instead ERA-Interim) NAT, estimated negatively affected most, while other species smaller extent. If parametrizations very posterior can still be successfully estimated, but experiment revealed source location important This work suggests upcoming sensor will provide sufficient accuracy