Aerosol-cloud interactions represent the most significant source of uncertainty in global radiation budget estimates, particularly for secondary organic aerosols (SOA). Given the complex nature of SOA sources, molecular compositions, and formation mechanisms, current knowledge of their interactions with clouds remains highly limited. In this study, we developed a cloud parcel model incorporating microphysical processes from the molecular-level kinetic SOA model of CSVA (CSVA-cloud). A central feature of our model is its consistent treatment of water molecules (H₂O) and organic compounds within a unified framework for simulating gas-particle partitioning processes. After developing the model, we thoroughly evaluated the model's performance against field observations and laboratory cloud-water simulation experiments, demonstrating its excellence in capturing cloud microphysics and SOA evolution. Using CSVA-cloud model, we systematically simulated the transport and transformation of SOA and their organic vapors in both shallow and deep convective clouds. Our results reveal a fundamental contrast: shallow convective clouds significantly enhance SOA formation, driven mainly by the promotion of gas–particle partitioning due to cloud water. In contrast, deep convective clouds function primarily as a net sink for SOA, owing to their efficient removal through precipitation scavenging. We further examined SOA's feedback on clouds and found that higher SOA number concentrations suppress deep convection through reduced precipitation and increased cloud water loading, leading to reduced vertical velocity and lower cloud tops. In contrast, condensation of organic vapors enhances convective clouds by lowering the critical supersaturation for particle activation, particularly at higher altitudes, thereby promoting the formation of high-level clouds. This study not only provides a powerful modeling tool but also clarifies the distinct roles that different types of convective clouds play in the SOA life cycle and feedback of SOA on convince clouds. These insights offer critical theoretical support for more accurate assessment of the climatic and environmental impacts of aerosols.

二次有机气溶胶,对流云,气溶胶与云相互作用,分子组成