Dissolved organic carbon and nitrogen cycling along the west Antarctic Peninsula during summer
Dissolved organic carbon and nitrogen cycling along the west Antarctic Peninsula during summer
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DOI：
10.1016/j.pocean.2022.102854
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发表时间：
2022-07
影响因子：
4.1
通讯作者：
Ribanna Dittrich;S. Henley;H. Ducklow;M. Meredith
中科院分区：
文献类型：
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作者：
Ribanna Dittrich;S. Henley;H. Ducklow;M. Meredith
溶解有机物在西南极半岛（WAP）地区的生产循环还没有得到很好的理解。在这项研究中，溶解有机碳（DOC）和氮（DON）的浓度和其他地球化学测量收集沿着WAP货架在2017年夏季。上层海洋的DOC和DON浓度均低于低纬度地区（38.13-48.00 μmol C L−1，2.90-10.52 μmol N L−1）。DOC在初级生产过程中与颗粒有机碳一起沿着产生，随后被细菌消耗。DON显示出高变异性，并且更可能是仅在表面沃茨中的细菌活性的产物。硝酸盐和颗粒态氮的N-同位素组成显示强烈的硝化作用，特别是沿沿着，并支持强烈的上层海洋循环的颗粒和溶解形式的有机物的研究结果。在WAP的陆架沃茨，生产性表层DOM的输出可以忽略不计。来自冰川融化区的样本显示DON浓度增加（7.88-10.52 μmol N L−1），因此我们得出结论，南极冰川的不断变暖和持续融化可能导致溶解有机物浓度更高，但细菌活性也更高，上层海洋碳和氮循环更强烈。
The cycling of dissolved organic matter in the productive west Antarctic Peninsula (WAP) region is not well understood. For this study, dissolved organic carbon (DOC) and nitrogen (DON) concentrations and other biogeochemical measurements were collected along the WAP shelf during austral summer 2017. Concentrations of both DOC and DON in the upper ocean were lower than in lower latitudes (38.13–48.00 μmol C L−1, 2.90–10.52 μmol N L−1). DOC is produced along with particulate organic carbon during primary production, and is subsequently consumed by bacteria. DON shows high variability and is more likely the product of bacterial activity only in the surface waters. The N-isotopic composition of nitrate and particulate nitrogen showed intense nitrification, especially along the coast, and supports the findings of intense upper ocean cycling of organic matter of both particulate and dissolved forms. Export of DOM from the productive surface layer was negligible in the shelf waters of the WAP. Samples from glacial melt areas showed increased DON concentrations (7.88–10.52 μmol N L−1) so we conclude that increasing warming and continuing melting of Antarctic glaciers may lead to higher concentrations of dissolved organic matter but also higher bacterial activity with more intense upper-ocean carbon and nitrogen cycling.