Oxygen, carbon, and nutrients in the oligotrophic eastern subtropical North Atlantic
Oxygen, carbon, and nutrients in the oligotrophic eastern subtropical North Atlantic
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贫营养东亚热带北大西洋的氧、碳和营养物
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
W. Koeve
中科院分区：
文献类型：
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作者：
P. Kähler;A. Oschlies;H. Dietze;W. Koeve
贝塔三角区是北大西洋东部亚热带贫营养区的一个区域，以其神秘的氧、碳和氮平衡而闻名，据说其中的营养供应只能解释估计碳输出所需的一小部分产量。溶解有机碳的积累率和溶解有机氮的利用率在地表水和利用的氧气，消耗的有机物，硝酸盐和磷酸盐再生地下水的评估，表明传统的生产估计错过了生物生产的很大一部分。
总有机碳，主要是溶解（DOC），由俯冲浅出口负责约50-70%的表观氧利用率在地下水之间的基地的表层约。140米左右。195米的深度，但它是微不足道的下面。此外，地表水中估计有1.0至1.75 mol DOC m−2 a−1的累积。包括DOC的动态在其碳平衡揭示了这个超贫营养的海洋部分的表面是净自养。
增加地下值的过量氮（DINxs）意味着出口的氮从地表水产生的生产不完全由新的硝酸盐从下面供应。总有机氮（几乎完全溶解的，DON）在表层消耗的速率估计为0.13至0.23 mol m−2 a−1。溶解性有机磷（DOP）没有同方向的变化。因此，DON利用有助于显著的地下DINxs特征。
DOC的输出和积累在地表水和近地表水的碳平衡中起着重要作用。DON的利用，可能，N2固定贡献显着金额的地表水的氮供应。这些过程可以关闭贝塔三角区神秘的碳和氮平衡。然而，没有类似的过程可以解释这一地区磷供应的同样神秘的情况。
The Beta Triangle, a region of the oligotrophic subtropical eastern North Atlantic Ocean, is notorious for its enigmatic oxygen, carbon, and nitrogen balances, in which nutrient supply is said to explain only a fraction of production necessary for estimated carbon export. Rates of dissolved organic carbon accumulation and dissolved organic nitrogen utilization in surface water and an assessment of oxygen utilized, organic matter consumed, and nitrate and phosphate regenerated in subsurface water, show that conventional production estimates miss substantial shares of biotic production.
The shallow export of total organic carbon, predominantly dissolved (DOC), by subduction is responsible for about 50–70% of apparent oxygen utilization in subsurface water between the base of the surface layer at ca. 140 m and ca. 195 m depth, but it is insignificant below. Additionally, there is an estimated accumulation of 1.0 to 1.75 mol DOC m−2 a−1 in surface water. Including DOC dynamics in its carbon balance reveals the surface of this ultra-oligotrophic part of the ocean to be net autotrophic.
Increasing subsurface values of excess nitrogen (DINxs) imply the export of nitrogen from surface water stemming from production not exclusively fuelled by new nitrate supplied from below. Total organic nitrogen (almost exclusively dissolved, DON) is consumed in the surface layer at a rate estimated at 0.13 to 0.23 mol m−2 a−1. There is no variation in dissolved organic phosphorus (DOP) in the same direction. DON utilization thus contributes to the pronounced subsurface DINxs signature.
DOC export and accumulation are important in the carbon balance in surface and near-surface water. DON utilization and, probably, N2 fixation contribute significant amounts to the nitrogen supply of surface water. These processes can close part of the enigmatic carbon and nitrogen balances in the Beta Triangle. There are, however, no comparable processes which can explain the equally enigmatic situation concerning phosphorus supply in this area.