Abstract The sea surface microlayer (SML) is the uppermost layer of the water column that links the ocean and atmosphere. It accumulates a variety of biogenic surface-active and buoyant substances, including gelatinous material, such as transparent exopolymer particles (TEP) and Coomassie stainable particles (CSP), potentially affecting air–sea exchange processes. Here, we studied the influence of the annual cycle of phytoplankton production on organic matter (OM) accumulation in the SML relative to the subsurface water (SSW). Sampling was performed monthly from April 2012 to November 2013 at the Boknis Eck Time Series Station (Baltic Sea). For SML sampling, we used the Garrett screen, while SSW samples were collected by Niskin bottles at 1 m depth. Samples were analyzed for carbohydrates, amino acids, TEP, CSP, chlorophyll a (SSW only) and bacterial abundance. Our data showed that the SML reflected the SSW during most parts of the year, with changes mainly responding to bloom formation and decay. OM composition during phytoplankton blooms clearly differed from periods of higher bacterial abundance. Of all components investigated, only the enrichment of total carbohydrates in the SML was inversely related to the wind speed indicating that wind-driven mixing also affected the accumulation of OM in the SML during our study.

中文翻译：

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Boknis Eck Times 系列站（波罗的海）海面微层的季节性变化

摘要 海面微层（SML）是连接海洋和大气的水柱的最上层。它积累了多种生物表面活性和漂浮物质，包括凝胶状材料，如透明外聚合物颗粒 (TEP) 和考马斯染色颗粒 (CSP)，可能会影响海气交换过程。在这里，我们研究了浮游植物生产的年度周期对 SML 中相对于地下水 (SSW) 的有机物质 (OM) 积累的影响。从 2012 年 4 月到 2013 年 11 月，每月在 Boknis Eck 时间序列站（波罗的海）进行一次采样。对于 SML 采样，我们使用 Garrett 筛网，而 SSW 样品由 Niskin 瓶在 1 m 深度收集。分析样品的碳水化合物、氨基酸、TEP、CSP、叶绿素 a（仅 SSW）和细菌丰度。我们的数据显示，SML 反映了一年中大部分时间的 SSW，其变化主要响应水华形成和衰变。浮游植物大量繁殖期间的 OM 组成明显不同于细菌丰度较高的时期。在研究的所有成分中，只有 SML 中总碳水化合物的富集与风速成反比，表明在我们的研究期间，风驱动混合也影响了 SML 中 OM 的积累。