Dual-typhoon outer circulation impact on the aerosol, clouds and boundary layer evolution: evidence from high-spectral-resolution lidar observations

The evolution of aerosols, clouds, and the planetary boundary layer (PBL) remains a major source of uncertainty in weather and climate prediction due to their strong coupling and pronounced spatiotemporal variability. As typical extreme weather systems, the typhoons can modulate aerosol loading, cloud development, and PBL dynamics not only within their core but also through their outer circulation, thereby increasing the complexity of such coupled system. Vertically resolved lidar observations provide an effective approach to capturing these processes. Particularly, high-spectral-resolution lidar (HSRL) enables precise and continuous day-and-night retrievals of atmospheric particles, enhancing the reliability of aerosol and cloud discrimination. In this study, HSRL observations are employed to investigate aerosol, cloud, and PBL evolution under the influence of the outer circulation of two concurrent typhoons (Chaba and Aere) during 2–3 July 2022. The HSRL measurements are further integrated with geostationary satellite observations and meteorological reanalysis data to evaluate data consistency and characterize the atmospheric response surrounding the typhoon systems. Our results reveal that (i) cloud layers ascended to altitudes close to the tropopause, with cloud tops reaching near 15 km; (ii) marine aerosols and moisture are transported inland via the outer circulations of typhoons, driving aerosol hygroscopic growth and water cloud condensation; and (iii) wave-like aerosol structures were observed near the PBL entrainment zone, indicating possible typhoon-induced gravity wave modulation. Our findings highlight the broader applicability of HSRL-based, multi-source observations for investigating complex atmospheric processes.