SP 1.5 Molecular characterization of dissolved organic matter in the sea surface microlayer (SML) and its influence on the inorganic carbon cycle

SP 1.5 海面微层（SML）中溶解有机物的分子特征及其对无机碳循环的影响

• 批准号: 496422622
• 负责人: Dr. Mariana Ribas Ribas, Ph.D.
• 金额: --
• 依托单位: Forschungsgruppe für Marine Geochemie
• 依托单位国家: 德国
• 项目类别: Research Units
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/496422622?language=en
• 关键词: SP; 1.5; Molecular; characterization; dissolved

Our motivation is to understand the role of dissolved organic matter (DOM) in the SML as a key component influencing air-sea gas exchange, carbonate chemistry, and ecosystem functioning of associated organisms (Engel et al., 2017). During our preliminary work, we have found indications for a yet unknown link between DOM and carbonate chemistry in the SML, as well as for high spatio-temporal dynamics in DOM composition. However, despite its apparent ephemeral character, the SML-DOM geometabolome (i.e., the entirety of the DOM pool that is produced and modified by biotic and abiotic processes) is still largely uncharted territory. Further, a mechanistic understanding of the driving forces behind DOM compartmentalization into distinct chemical fractions in the SML is hindered by the limited availability of data from a larger range of study sites under differing environmental and experimental conditions, as well as a lack of interdisciplinary studies combining physics, geochemistry, and biology. In other words, we are missing basic (organo-)geochemical information from the largest air-water interface on earth, with unknown consequences for the associated exchange of climate-relevant gases. In this project, we seek to fill this gap by complementary measurements of DOM composition and inorganic carbon system parameters. Relevance to the research unit BASS stems from the aim of our subproject to provide the missing basic biogeochemical information of the SML-DOM inventory, and set it into context with SML ecosystem processes including DOM production (SP1.1) as well as microbial (SP1.2) and photochemical (SP1.4) turnover. Furthermore, we will examine the contribution of the DOM geometabolome to the acid-base balance of the SML, which we expect to affect gas equilibria in the interface—within the carbonic acid system in particular—and therefore, impact greenhouse gas fluxes (SP2.1).

我们的动机是了解溶解有机物（DOM）在SML中的作用，作为影响气-海气体交换、碳酸盐化学和相关生物的生态系统功能的关键组分（Engel等人，2017年）。在我们的初步工作中，我们发现了DOM和碳酸盐化学SML之间的未知联系的迹象，以及DOM组成的高时空动态。然而，尽管其明显的短暂特征，SML-DOM几何禁忌（即，由生物和非生物过程产生和改变的整个DOM库）仍然是很大程度上未知的领域。此外，DOM划分成不同的化学组分在SML背后的驱动力的机械的理解是阻碍了有限的数据从更大范围的研究地点在不同的环境和实验条件下，以及缺乏跨学科的研究相结合的物理学，地球化学和生物学。换句话说，我们缺少了地球上最大的空气-水界面的基本（有机）地球化学信息，对气候相关气体的相关交换产生了未知的后果。在这个项目中，我们试图通过补充测量DOM组成和无机碳系统参数来填补这一空白。与研究单位BASS的相关性源于我们子项目的目的，即提供SML-DOM清单中缺失的基本生物地球化学信息，并将其与SML生态系统过程（包括DOM生产（SP1.1）以及微生物（SP1.2）和光化学（SP1.4）周转）相结合。此外，我们将研究DOM geometabolome对SML酸碱平衡的贡献，我们预计这会影响界面中的气体平衡，特别是碳酸系统内的气体平衡，从而影响温室气体通量（SP2.1）。