Distribution of dissolved organic nutrients and their effect on export production over the Atlantic Ocean
Distribution of dissolved organic nutrients and their effect on export production over the Atlantic Ocean
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DOI：
10.1029/2008gb003389
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发表时间：
2009-12
影响因子：
5.2
通讯作者：
S. Torres-Valdés;V. Roussenov;Richard Sanders;Sarah E. Reynolds;Xi Pan;R. Mather;Angela Landolfi;George A. Wolff;E. Achterberg;Richard G. Williams
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文献类型：
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作者：
S. Torres-Valdés;V. Roussenov;Richard Sanders;Sarah E. Reynolds;Xi Pan;R. Mather;Angela Landolfi;George A. Wolff;E. Achterberg;Richard G. Williams
本文根据大西洋8个断面的实测资料，综合分析了大西洋溶解有机氮（DON）和磷（DOP）的分布，其中6个断面位于50°N和50°S之间，2个断面位于24°和36°N之间。在整个热带和亚热带大西洋，DON和DOP提供了占主导地位的贡献，总氮和磷池的表面沃茨以上的温跃层。DON和DOP浓度升高（分别>5和>0.2 μmol L−1）发生在北大西洋副热带环流东侧以及北大西洋和南大西洋副热带环流赤道两侧的表面沃茨，而DOP浓度特别低（<0.05 μmol L−1）发生在北大西洋副热带环流沿着36°N的北方。这种分布与在环流边缘形成的有机营养物相一致，这些营养物通过环流循环重新分布，从而支持碳输出。DON和DOP输送和循环对出口生产的影响在一个涡动允许的，耦合的物理和营养物模型中进行了40年的综合研究：有机营养物在北非的上升流区产生，并横向转移到环流内部，部分由中尺度涡动环流促进，以及作为翻转环流的一部分从热带向北流动。输入的半不稳定DON和DOP的热带和亚热带大西洋发挥了重要作用，在维持高达40和70%的模拟颗粒N和P的出口，特别是在东部和赤道两侧的副热带环流。
A synthesis is provided of dissolved organic nitrogen (DON) and phosphorus (DOP) distributions over the Atlantic Ocean based upon field data from eight recent transects, six meridional between 50°N and 50°S and two zonal at 24° and 36°N. Over the entire tropical and subtropical Atlantic, DON and DOP provide the dominant contributions to total nitrogen and phosphorus pools for surface waters above the thermocline. Elevated DON and DOP concentrations (>5 and >0.2 μmol L−1, respectively) occur in surface waters on the eastern side of the North Atlantic subtropical gyre and equatorial sides of both the North and South Atlantic subtropical gyres, while particularly low concentrations of DOP (<0.05 μmol L−1) occur over the northern flank of the North Atlantic subtropical gyre along 36°N. This distribution is consistent with organic nutrients formed at the gyre margins supporting carbon export as they are redistributed via the gyre circulation. The effect of DON and DOP transport and cycling on export production is examined in an eddy‐permitting, coupled physical and nutrient model integrated for 40 years: organic nutrients are produced in the upwelling zones off North Africa and transferred laterally into the gyre interior, facilitated in part by the mesoscale eddy circulation, as well as fluxed northward from the tropics as part of the overturning circulation. Inputs of semilabile DON and DOP to the tropical and subtropical Atlantic Ocean play an important role in sustaining up to typically 40 and 70% of the modeled particulate N and P export, particularly on the eastern and equatorward sides of the subtropical gyres.