Critical Role of Sea Spray Aerosol Production Pathways in Particulate Transfer Across the Sea-Air Interface

Sea spray aerosols (SSA) play a crucial role in transferring particulates from oceanic water to the atmosphere. The production pathways of SSA from bubble bursting include jet drops from bubble cavity collapse, surface film drops from bubble cap disintegration and collision film drops from underwater bubble collision. While the physical formation of these drops has been extensively studied, the mechanisms governing particle enrichment and transfer within these individual drop types remain poorly understood. This study systematically investigates particle enrichment and transfer across the three types of drops. While previous studies suggested only hydrophobic particles could be enriched by SSA, our findings reveal that both hydrophilic and hydrophobic particles can be enriched in all drop types, with surface film drops exhibiting significantly greater enrichment than previously reported. We propose for the first time that particle enrichment occurs during water drainage in the bubble film. These findings enhance our understanding of mass transfer at water-air interface.海洋喷雾气溶胶（Sea spray aerosols, SSA）在将颗粒物从海洋水体输送至大气的过程中发挥着关键作用。海洋喷雾气溶胶经气泡破碎产生的路径包括气泡腔坍塌产生的射流液滴、气泡帽破裂产生的表面膜液滴，以及水下气泡碰撞产生的碰撞膜液滴。尽管学界已对这些液滴的物理形成过程开展了大量研究，但针对各类型液滴内部颗粒物富集与迁移的调控机制，目前仍知之甚少。本研究系统探究了三类液滴的颗粒物富集与迁移规律。尽管以往研究认为仅疏水性（hydrophobic）颗粒物可通过海洋喷雾气溶胶实现富集，但本研究结果显示，亲水性（hydrophilic）与疏水性颗粒物均可在所有液滴类型中发生富集，且表面膜液滴的富集程度显著高于此前报道水平。本研究首次提出，颗粒物富集过程发生在气泡膜的排水阶段。上述研究结果深化了我们对水-气界面传质过程的认知。