Abstract：
Marine biological activities make a non-negligible contribution to atmospheric aerosols, leading to potential impacts on the regional atmospheric environment and climate. The eastern China seas are highly productive with significant emissions of biogenic substances, but the spatiotemporal variations of marine biogenic aerosols are not well known. Air mass exposure to chlorophyll a (AEC) can be used to indicate the influence of biogenic sources on the atmosphere to a certain degree. In this study, the 12 year (2009-2020) daily AEC were calculated over the eastern China seas, showing the spatial and seasonal patterns of marine biogenic influence intensity which were co-controlled by surface phytoplankton biomass and boundary layer height. By combining the AEC values, relevant meteorological parameters, and extensive observations of a typical biogenic secondary aerosol component, methanesulfonate (MSA), a parameterization scheme for MSA simulation was successfully constructed. This AEC-based approach with observation constraints provides a new insight into the distribution of marine biogenic aerosols. Meanwhile, the wintertime air mass retention over land exhibited a significant decrease, showing a decadal weakening trend of terrestrial transport, which is probably related to the weakening of the East Asian winter monsoon. Thus, marine biogenic aerosols may play an increasingly important role in the studied region.
摘要：
海洋生物活动对大气气溶胶有不可忽视的贡献,导致对区域大气环境和气候的潜在影响。中国东部海域生产力很高，生物物质大量排放，但是海洋生物气溶胶的时空变化尚不为人所知。空气质量暴露于叶绿素a（AEC）可用于在一定程度上指示生物源对大气的影响。在这项研究中,计算了中国东部海域12年(2009-2020年)的每日AEC，显示了海洋生物成因影响强度的空间和季节模式，该模式由表层浮游植物生物量和边界层高度共同控制。通过组合AEC值，相关气象参数，以及对典型的生物次级气溶胶成分的广泛观察，甲磺酸酯（MSA），成功构建了MSA仿真的参数化方案。这种具有观察约束的基于AEC的方法为海洋生物气溶胶的分布提供了新的见解。同时,冬季大气在陆地上的滞留量显著下降，显示出陆地运输的年代际减弱趋势，这可能与东亚冬季风减弱有关。因此，海洋生物气溶胶可能在研究区域发挥越来越重要的作用。
