Large eddy simulation of the bubbly ocean: New insights on subsurface bubble distribution and bubble-mediated gas transfer
Large eddy simulation of the bubbly ocean: New insights on subsurface bubble distribution and bubble-mediated gas transfer
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DOI：
10.1029/2011jc007766
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发表时间：
2012-04
影响因子：
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通讯作者：
Jun‐Hong Liang;J. McWilliams;P. Sullivan;B. Baschek
中科院分区：
文献类型：
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作者：
Jun‐Hong Liang;J. McWilliams;P. Sullivan;B. Baschek
[1]采用多尺度多气泡模型与大涡模拟模型耦合，模拟了湍流海洋边界层中气泡的演化过程。由破碎波注入的气泡被幕式气泡羽流带入边界层，并在朗缪尔环流的辐合区形成近地面条纹。平衡气泡分布随深度呈指数衰减，并且是间歇气泡羽流的表现，其气泡数密度比平均气泡数密度高至少一个数量级。气泡在喷射区的分布受喷射、湍流输送和溶解的影响。喷射区下方气泡的分布取决于湍流和溶解的强度。对于给定的海况，气泡e折叠深度随摩擦速度线性增加。波龄是气泡e折叠深度的附加控制参数。气泡的浮力减弱了朗缪尔环流和近地面湍流动能耗散。浮力效应随着风速的增加而增加。通过气泡的气体通量取决于风速和波龄。对于给定的海况，气泡通量随风速的五次幂而增加。
[1] The evolution of bubbles in a turbulent oceanic boundary layer is simulated using a multi-size multi-gas bubble model coupled with a Large Eddy Simulation model. Bubbles injected by breaking waves are brought into the boundary layer by episodic bubble plumes, and they form near-surface streaks in the convergence zone of Langmuir circulations. The equilibrium bubble distribution decays exponentially with depth and is a manifestation of intermittent bubble plumes whose bubble number density is at least one order of magnitude higher than the mean bubble number density. Bubble distribution in the injection zone is influenced by injection, turbulent transport, and dissolution. Bubble distribution below the injection zone is determined by the strength of turbulence and dissolution. For a given sea state, bubble e-folding depth increases linearly with friction velocity. Wave age is an additional governing parameter for bubble e-folding depth. The buoyancy of bubbles weakens both Langmuir circulations and near-surface turbulent kinetic energy dissipation. The buoyancy effect increases with wind speed. Gas flux through bubbles depends on both wind speed and wave age. For a given sea state, the bubble flux increases with wind speed to the fifth power.