Characterizing Aerosol Optical Properties and DirectRadiative Effects From the Perspective of Components: A Synergy Retrieval Study Based on Sun Photometer andLidar in Central China

Aerosols affect climate and air quality, but it remains challenging to simultaneously quantify their optical properties, vertical distribution, chemical components, and associated direct radiative effects using any single observing system. Here, we present a ground-based synergy retrieval study in Central China (Wuhan University; 30°32ʹN, 114°21ʹE) combining a CE-318T sun photometer, a 532-nm Mie lidar, and surface black-carbon measurements (AE-31) from July 2021 to August 2022, using the GRASP/GARRLiC framework with a component-based aerosol model (BC, BrC, dust, iron oxide, water-soluble salts, and aerosol water). The joint retrieval captures strong seasonality: winter shows the highest aerosol loading (AOD ~0.7 at 440 nm) with enhanced absorption (SSA <0.92) and elevated near-surface BC, while spring is strongly influenced by transported dust with a characteristic extinction peak near ~2.5 km and relatively high SSA; summer and autumn feature lower mean AOD but episodic enhancements consistent with regional transport/biomass burning. Retrieved annual column mass concentrations indicate low BC burden (2.49 mg m⁻²) yet disproportionate warming, with BC contributing +9.27 W m⁻² to shortwave DARE at the top of atmosphere (BrC: +0.10 W m⁻²), whereas total aerosols cool the system overall (−12.28 W m⁻² at TOA; −39.33 W m⁻² at the surface). Incorporating lidar-constrained vertical structure also improves agreement of retrieved surface BC versus measurements (R = 0.56), highlighting the value of synergy observations for component-aware radiative impact assessments and for complementing reanalysis products.