Boundaries of the Peruvian oxygen minimum zone shaped by coherent mesoscale dynamics
Boundaries of the Peruvian oxygen minimum zone shaped by coherent mesoscale dynamics
复制标题
由相干中尺度动力学形成的秘鲁氧最低区的边界
DOI：
10.1038/ngeo2570
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发表时间：
2015
影响因子：
18.3
通讯作者：
V'eronique Garccon
中科院分区：
文献类型：
--
作者：
J. Bettencourt;C. L'opez;Emilio Hern'andez Garc'ia;I. Montes;J. Sudre;B. Dewitte;A. Paulmier;V'eronique Garccon
海水中的溶解氧影响海洋生物栖息地和生物地球化学循环。氧气缺乏的海洋区域占海洋体积的7%和海洋面积的8%，并且被认为正在扩大。其中最明显的是秘鲁附近的地区，那里以锋面和涡旋形式的中尺度活动很强。在这里，我们在拉格朗日框架下，利用物理-生物地球化学耦合数值模式和有限大小的Lyapunov指数场，研究秘鲁氧极小带的动力学，以评估中尺度活动的作用。我们发现，在380到600米的深度，中尺度结构有两种截然不同的作用。首先，它们的平均位置和路径划定并维持氧最小带边界。其次，它们的高频波动将氧气注入到氧最小区域边界，涡流通量比平均氧通量高一个数量级。我们得出的结论是，这些涡流通量有助于秘鲁氧气极小区的通风。
Dissolved oxygen in sea water affects marine habitats and biogeochemical cycles. Oceanic zones with oxygen deficits represent 7% of the volume and 8% of the area of the oceans, and are thought to be expanding. One of the most pronounced lies in the region off Peru, where mesoscale activity in the form of fronts and eddies is strong. Here, we study the dynamics of the Peruvian oxygen minimum zone in a Lagrangian framework, using a coupled physical-biogeochemical numerical model and finite-size Lyapunov exponent fields, to evaluate the role of mesoscale activity. We find that, at depths between 380 and 600 m, mesoscale structures have two distinct roles. First, their mean positions and paths delimit and maintain the oxygen minimum zone boundaries. Second, their high-frequency fluctuations inject oxygen across the oxygen minimum zone boundaries and eddy fluxes are one order of magnitude higher than mean oxygen fluxes. We conclude that these eddy fluxes contribute to the ventilation of the Peruvian oxygen minimum zone.
影响因子：
56.9
作者：
Stramma, Lothar;Johnson, Gregory C.;Mohrholz, Volker
通讯作者：
Mohrholz, Volker