Extraction of Stratospheric Aerosol Extinction Profiles from Limb-scattering Signals Measured by the BLS on the Tiangong-2 Space Laboratory

Stratospheric aerosol extinction profile data are crucial for studying climate change and various atmospheric physical and chemical processes. Limb observation serves as one of the most effective methods for obtaining global stratospheric aerosol extinction profiles. In this paper, based on the color-ratio and optimal estimation methods, aerosol extinction profiles between 10 and 35 km were successfully extracted from the limb-scattering signals measured by the Backward Limb Spectrometer (BLS) onboard the Tiangong-2 space laboratory. The aerosol extinction profiles derived from BLS were compared with those from the OMPS-LP v2.0 aerosol product, and the results showed good consistency. Using the average profile of each pair of BLS and OMPS-LP cross-observations as a reference, the mean relative errors of BLS are generally within ±15% between 15 and 30 km, with a correlation coefficient of 0.955. However, larger errors may occur below 15 km. Sensitivity analysis indicates that the larger errors at lower altitudes are attributed to inaccuracies in the tangent height and the stratospheric aerosol particle size distribution model, both of which affect the accuracy of the final retrievals.