Advances in understanding ice–ocean stress during and since AIDJEX
Advances in understanding ice–ocean stress during and since AIDJEX
复制标题
AIDJEX 期间及之后对冰海压力的理解取得的进展
DOI：
10.1016/j.coldregions.2011.05.001
复制
发表时间：
2012
影响因子：
4.1
通讯作者：
M. Mcphee
中科院分区：
文献类型：
--
作者：
M. Mcphee
冰/海洋阻力（动量交换）的变化是浮冰模拟的一个重要但经常被忽视的方面。它通常被参数化为与冰和未受干扰的海洋之间的速度差的平方成比例，通常具有恒定的角度偏移以解释冰-海洋边界层中的旋转效应。这种方法是批评光的广泛观察，揭示了基本的湍流尺度内的IOBL动量交换。这些尺度所隐含的流体动力学相似性为解决影响阻力关系的几个因素提供了一个框架，这些因素包括冰粗糙度的变化、相对漂移速度、冰/海洋界面处的浮力通量和上层海洋的分层。这些都是检查和讨论在北极冰盖最近的变化。阻力定律是用无量纲表面速度来表示的，其最简单的形式称为Rossby相似性，并明确说明了下表面水力粗糙度z0的变化。概括，包括界面浮力通量也进行了描述和说明，并讨论了近地表海洋分层的影响。基于冰下测量的z0估计值差异很大;通过结合观测和简单的IOBL建模，试图将这些减少到与不同冰类型相关的可管理集合。
Variation of ice/ocean drag (momentum exchange) is an important yet often overlooked aspect of pack ice modeling. It is commonly parameterized as proportional to the square of the velocity difference between the ice and the undisturbed ocean, often with a constant angle offset to account for rotational effects in the ice–ocean boundary layer. This approach is critiqued in light of extensive observations that have revealed the underlying turbulence scales governing momentum exchange within the IOBL. Fluid dynamical similarity implied by these scales provides a framework for addressing several factors that affect the drag relationship, including variation in ice roughness, relative drift speed, buoyancy flux at the ice/ocean interface, and stratification in the upper ocean. These are examined and discussed in light of recent changes in the Arctic ice pack. The drag law is formulated in terms of dimensionless surface velocity, which in its simplest form is called Rossby similarity, and accounts explicitly for variation in undersurface hydraulic roughness, z0. A generalization that includes interfacial buoyancy flux is also described and illustrated, and the impact of near surface ocean stratification is discussed. Estimates of z0based on underice measurements vary widely; by a combination of observations and simple IOBL modeling, an attempt is made to reduce these to a manageable set associated with distinct ice types.