Exploring aerosol-cloud interactions in liquid-phase clouds over eastern China and its adjacent ocean using the WRF-Chem-SBM model

This study employed the WRF-Chem-SBM model which couples spectral-bin cloud microphysics (SBM) and online aerosol module (MOSAIC) to investigate aerosol-cloud interactions in liquid-phase clouds over eastern China and its adjacent oceans. The results indicate that with an increase in aerosol number concentration (Na), cloud droplet number concentration (Nd) exhibits a trend of initially increasing and then decreasing, both over land and ocean. The difference lies in the stronger convective and land surface effects over land, leading to more intense activation, while over the ocean, weaker supersaturation and richer water vapor content result in weaker activation but more favorable conditions for cloud droplet growth. Cloud processes over land are more intense than over the ocean, but the cloud liquid water content (CLWC) in both regions shows a similar trend with the variation of Nd. In precipitating clouds with richer water content and stronger intracloud processes, as Nd increases, the cloud droplet effective radius decreases, and CLWC exhibits a gradual increase followed by a rapid decrease. In non-precipitating clouds with lower water content and weaker intracloud processes, the increase in Nd leads to a more gradual growth of CLWC, and the subsequent decrease in CLWC is also more subtle. Furthermore, this study discusses the impact of meteorological and aerosol conditions on aerosol activation and cloud development. Environments with a moderate Na are more conducive to aerosol activation, while in environments with low to moderate Na, CLWC exhibits faster growth. Compared to humidification, cooling has a more significant effect on aerosol activation and CLWC growth.