Advanced simulation and measurement of skylight polarization patterns across distinct aerosol type environments

Atmospheric aerosols significantly affect skylight polarization, yet variations in polarization patterns across distinct aerosol type environments remain insufficiently understood due to limitations in current simulation and measurement techniques. This study integrates advanced simulation and measurement methods to investigate skylight polarization patterns in rural, urban, maritime, and desert aerosol type environments. Using the Backward Markov Chain Monte Carlo (B-MCMC) method for simulations and a novel Division of Focal Plane (DOFP) polarization imaging system for real-time, full-sky measurements, the study reveals substantial differences in polarization patterns across the four environments we studied. Rural and urban environments exhibit stronger polarization at longer wavelengths, while desert and maritime environments show enhanced polarization in the UVA and long-wave blue regions, respectively. Rural and maritime aerosols, with lower mass concentrations, display more pronounced full-sky degree of polarization (DOP) distributions. In contrast, soot and mineral particles in urban and desert environments significantly attenuate polarization, with maximum DOP values of 0.524, 0.464, 0.576, and 0.442, respectively. The angle of polarization (AOP) remains consistent across environments, though high-reflectance surfaces introduce local deviations. Each environment also shows distinct aerosol optical depth (AOD) and Ångström exponent (AE) characteristics. Comparisons between simulated and measured polarization patterns show strong agreement, with a maximum DOP discrepancy of 8.8 %, attributed to factors such as undetectable thin clouds and non-spherical particles in complex conditions. These results offer valuable insights for improving aerosol remote sensing and enhancing the understanding of polarized radiative transfer in the atmosphere.