Dissolved oxygen response to wind‐inflow interactions in a stratified reservoir
Dissolved oxygen response to wind‐inflow interactions in a stratified reservoir
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分层水库中溶解氧对风-流入相互作用的响应
DOI：
10.4319/lo.2007.52.5.2027
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
J. Imberger
中科院分区：
文献类型：
--
作者：
D. Botelho;J. Imberger
一场战役和数值模拟的结果被用来显示如何施加的物理机制的长度尺度和时间尺度，确定占主导地位的地球化学过程。作为一个例子，蛇河流入布朗利水库的动力学进行了研究，以解释水库上游部分表层的缺氧区（氧块）的发生和维持。氧气块位于水库的一个区域，在该区域中，由于较小的风应力和减少的蒸发率，表层较温暖。数值模拟再现了由入流、出流、风应力和大气热通量引起的水动力场观测结果。当风应力反对流入，表面层被捕，形成一个收敛区，停滞的流体，并允许在水中的生物需氧量消耗溶解氧（DO）在地表水;直接测量表明，垂直混合是小的，只有轻微的氧消耗。在水柱中的净溶解氧生产与所观察到的变化与浮力流入模式，即，在溢出和阴天和源在interflow和强烈的阳光下，一个汇是一致的。这些观察结果提供了进一步的证据，证明该地区的水是生物隔离的，这一点得到了结垢分析的证实。现代数值水动力模拟已经达到了一定的精度水平，它们可以用来识别和量化生态位。
Results of a field campaign and numerical simulations are used to show how physical mechanisms impose length scales and timescales that determine the dominant biogeochemical process. As an example, the dynamics of the Snake River inflows into Brownlee Reservoir is investigated to explain the onset and maintenance of an oxygen‐depleted region (the oxygen block) in the surface layer of the upstream part of the reservoir. The oxygen block was located in a region of the reservoir in which the surface layer was warmer as a result of smaller wind stresses and reduced evaporation rates. Numerical simulations reproduced the hydrodynamic field observations resulting from inflow, outflow, wind stress, and atmospheric heat fluxes. When the wind stress opposed the inflow, the surface layer was arrested, forming a zone of convergence, stagnating the fluid and allowing the biological oxygen demand in the water to deplete the dissolved oxygen (DO) in the surface water; direct measurements showed that vertical mixing was small and contributed only marginally to the oxygen depletion. Net DO production in the water column was consistent with the observed variation with the buoyant inflow pattern, that is, a sink during overflows and overcast days and a source during interflows and intense sunlight. These observations provided further evidence that the water in this region was biologically isolated as confirmed by a scaling analysis. Modern numerical hydrodynamic simulations have reached a level of accuracy where they may be used to identify and quantify ecological niches.