Characterizing the composition of marine dissolved organic matter (DOM) is important for gaining insight into its role in oceanic biogeochemical cycles. Using Fourier transform ion cyclotron resonance mass spectrometry, we analyzed the molecular composition of solid phase extracted (SPE) DOM from the northeast Atlantic to investigate the specificity of the DOM pool of the individual major water masses of the North Atlantic. All 272 measured samples from depths ranging from 87 to 5609 m and latitudes from 24°N to 68°N shared 96% similarity (on a Bray-Curtis scale) in their DOM composition. Small variations between subsurface and deep samples and among latitudinal groupings were identified, but overall, water mass specific SPE-DOM composition was not apparent. A strong correlation between a calculated degradation index and water mass age indicates variability in portions of the DOM pool, and ocean-scale differences were observed between the North Atlantic and deep North Pacific. However, within the deep northeast Atlantic, conservative mixing primarily drives the molecular composition of SPE-DOM.

中文翻译：

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东北大西洋深水物质混合过程中溶解有机物分子组成的保护。

表征海洋溶解有机物（DOM）的组成对于深入了解其在海洋生物地球化学循环中的作用非常重要。使用傅立叶变换离子回旋共振质谱，我们分析了来自东北大西洋的固相萃取（SPE）DOM的分子组成，以研究北大西洋各个主要水团的DOM池的特异性。所有272个采样样本的深度在87到5609 m之间，纬度在24°N到68°N之间，其DOM组成具有96％的相似度（在Bray-Curtis尺度上）。地下和深层样品之间以及纬度组之间的微小变化被确定，但总体而言，水质比SPE-DOM的组成并不明显。计算出的降解指数与水质年龄之间的强相关性表明了DOM池部分的可变性，并且在北大西洋和深北太平洋之间观察到了海洋尺度的差异。但是，在大西洋东北部深部，保守混合主要驱动SPE-DOM的分子组成。