Organic compounds released from wildfires and residential biomass burning play a crucial role in shaping the composition of the atmosphere. The solubility and subsequent reactions of these compounds in the aqueous phase of clouds and fog remain poorly understood. Nevertheless, these compounds have the potential to become an important source of secondary organic aerosol (SOA). In this study, we simulated the aqueous SOA (aqSOA) from residential wood burning emissions under atmospherically relevant conditions of gas-liquid phase partitioning, using a wetted-wall flow reactor (WFR). We analyzed and quantified the specific compounds present in these emissions at a molecular level and determined their solubility in clouds. Our findings reveal that while 1% of organic compounds are fully water-soluble, 19% exhibit moderate solubility and can partition into the aqueous phase in a thick cloud. Furthermore, it is found that the aqSOA generated in our laboratory experiments has a substantial fraction being attributed to the formation of oligomers in the aqueous phase. We also determined an aqSOA yield of 20% from residential wood combustion, which surpasses current estimates based on gas-phase oxidation. These results indicate that in-cloud chemistry of organic gases emitted from wood burning can serve as an efficient pathway to produce organic aerosols, thus potentially influencing climate and air quality.

野火和住宅生物质燃烧释放的有机化合物在塑造大气成分方面发挥着至关重要的作用。这些化合物在云和雾的水相中的溶解度和随后的反应仍然知之甚少。然而，这些化合物有潜力成为二次有机气溶胶（SOA）的重要来源。在这项研究中，我们使用湿壁流反应器 (WFR) 模拟了在大气相关的气-液相分离条件下住宅木材燃烧排放的水性 SOA (aqSOA)。我们在分子水平上分析和量化了这些排放物中存在的特定化合物，并确定了它们在云中的溶解度。我们的研究结果表明，虽然 1% 的有机化合物完全溶于水，但 19% 的有机化合物表现出中等溶解度，并且可以在浓云中分配到水相中。此外，我们发现在我们的实验室实验中产生的 aqSOA 有很大一部分归因于水相中低聚物的形成。我们还确定了住宅木材燃烧的 aqSOA 产量为 20%，这超出了目前基于气相氧化的估计。这些结果表明，木材燃烧释放的有机气体的云内化学可以作为产生有机气溶胶的有效途径，从而潜在地影响气候和空气质量。