发表机构
Newcastle University; University College London（纽卡斯尔大学; 伦敦大学学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文研究垂直混合对海洋锋生的影响，发现当锋面宽度超过临界值时，垂直混合可直接抑制锋生性次级环流，并通过非线性迭代方法找到平衡态，扩展了现有渐近解。研究揭示了垂直混合在锋面动力学中的关键作用。
AI 中文摘要
锋生是海洋锋（上层海洋中水平密度梯度强烈的区域）增强的过程。这是一个高度非线性的现象，由许多相互竞争的因素引起，如背景应变、不稳定性和海面强迫。垂直混合在控制锋生和海洋锋的长期动力学方面起着复杂的作用。对于弱锋，已有研究表明垂直混合驱动剪切弥散，从而在长时间尺度上进一步削弱锋面。然而，垂直混合也会混合垂直剪切的斜压热风速度，使锋面失去平衡，并导致可能增强锋面的次级环流发展。本文表明，只要锋面宽度大于临界值，垂直混合就能直接作用于对抗锋生性次级环流。文中描述了一种非线性迭代方法，用于寻找垂直混合阻止锋生的平衡态，并讨论了该状态的参数依赖性。此外，现有的浮力和速度场渐近解被扩展，并发现即使在正式有效区域之外，这些解也与这些平衡态紧密匹配。
英文摘要
Frontogenesis is the process by which ocean fronts--regions of strong horizontal density gradients in the upper ocean--strengthen. It is a highly non-linear phenomenon arising from many competing effects, such as background strain, instabilities, and surface forcing. Vertical mixing plays a complicated role in governing both frontogenesis and the long-term dynamics of ocean fronts. For weak fronts, it has been shown to drive shear dispersion which further weakens the front over long timescales. However, vertical mixing also mixes the vertically-sheared thermal wind velocity, driving the front out of balance and causing a secondary circulation to develop that may strengthen the front. Here, it is shown that vertical mixing can directly act to oppose the frontogenetic secondary circulation, provided the frontal width is larger than a critical value. A non-linear iteration method is described for finding balanced states in which vertical mixing arrests frontogenesis and the parameter dependence of this regime is discussed. Further, existing asymptotic solutions for the buoyancy and velocity fields are extended and found to closely match these balanced states, even outside their region of formal validity.
Comments11 pages, 2 figures
