Multiscalar Mixing in Turbulent Overturns

0095640湍流翻转的SMYTHRECT数值模拟将扩展到与海洋温跃层更直接相关的情况。基于非受迫剪切层中湍流发展和衰减的模拟结果表明，在湍流前发展阶段的混合比在完全湍流衰减阶段的混合更有效。推测是，观测到的不同海洋流型之间混合效率的差异取决于花在湍流前阶段的相对时间，而不是充分发展的湍流阶段。如果是这样，那么作用力的性质可能决定混合的效率，这是一个有价值的简化。为了验证这一猜想，我们将进行一系列稳定和阶段性强迫的实验。此外，数值模拟将检查非受迫和受迫倾覆时的差异扩散，以确定在哪些情况下最重要。

0095640 SmythDirect numerical simulations of turbulent overturns will be extended to case more directly relevant to the ocean thermocline. The present results based on simulations of turbulence developing and decaying in an unforced shear layer show that mixing is more efficient in the pre-turbulent developing phase than in the fully turbulent decaying phase. The speculation is that the observed difference in mixing efficiency among the various ocean flow regimes depends on the relative time spent in the pre-turbulent phase as opposed to the fully developed turbulence. If so, then the nature of the forcing may determine the efficiency of mixing, a valuable simplification. A series of experiments with steady and episodic forcing will conducted to test this conjecture. In addition, numerical simulations will examine differential diffusion in unforced and forced overturns to determine under which circumstances it is most important.