Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, 92093, USA.
Takeda, San Diego, CA, 92121, USA.
Sci Rep. 2022 Mar 4;12(1):3580. doi: 10.1038/s41598-022-07335-9.
Ocean waves transfer sea spray aerosol (SSA) to the atmosphere, and these SSA particles can be enriched in organic matter relative to salts compared to seawater ratios. A fundamental understanding of the factors controlling the transfer of biogenic organic matter from the ocean to the atmosphere remains elusive. Field studies that focus on understanding the connection between organic species in seawater and SSA are complicated by the numerous processes and sources affecting the composition of aerosols in the marine environment. Here, an isolated ocean-atmosphere system enables direct measurements of the sea-air transfer of different classes of biogenic organic matter over the course of two phytoplankton blooms. By measuring excitation-emission matrices of bulk seawater, the sea surface microlayer, and SSA, we investigate time series of the transfer of fluorescent species including chlorophyll-a, protein-like substances, and humic-like substances. Herein, we show the emergence of different molecular classes in SSA at specific times over the course of a phytoplankton bloom, suggesting that SSA chemical composition changes over time in response to changing ocean biological conditions. We compare the temporal behaviors for the transfer of each component, and discuss the factors contributing to differences in transfer between phases.
海浪将海雾气溶胶（SSA）转移到大气中，与海水相比，这些 SSA 颗粒中的有机物含量相对较高。目前，人们对于控制海洋生物源有机物向大气传输的因素仍缺乏基本了解。由于影响海洋环境中气溶胶组成的过程和来源众多，因此，重点关注了解海水中有机物种与 SSA 之间联系的现场研究变得复杂起来。在本研究中，一个隔离的海洋-大气系统能够直接测量两个浮游植物水华过程中不同类别的生物源有机物的海-气转移。通过测量海水、海水表层和 SSA 的激发-发射矩阵，我们研究了包括叶绿素 a、蛋白类物质和腐殖质类物质等荧光物质的转移时间序列。在此，我们展示了在浮游植物水华过程中特定时间 SSA 中不同分子类别的出现，表明 SSA 的化学成分随时间变化而变化，以响应不断变化的海洋生物条件。我们比较了每个成分的转移时间行为，并讨论了导致不同相之间转移差异的因素。
