The parametrization of drag induced by stratified flow over anisotropic orography
The parametrization of drag induced by stratified flow over anisotropic orography
复制标题
DOI：
10.1002/qj.49712656802
复制
发表时间：
2000-07
影响因子：
8.9
通讯作者：
J. Scinocca;N. McFarlane
中科院分区：
文献类型：
--
作者：
J. Scinocca;N. McFarlane
提出了一种新的大气环流模式（GCM）中未解析地形（UT）气流阻力参数化方法。它由三个主要部分组成：无旋转情况下与自由传播的流体静力波相关的源谱和阻力的参数化，与低水平破波相关的阻力的参数化，以及与上游阻塞和lee - vortex动力学相关的低水平阻力的参数化。该方案的新颖之处包括：提出了一种考虑GCM分辨率且仅包含参数化方案所表示尺度的GCM网格单元UT的定义新方法；提出了一种用两波表示垂直动量通量方位角分布的新方法，两波的方向和量级随流动方向和各向异性而系统地变化；此外，还提出了一种新的形式阻力在低层的应用，它可以改变低层流动的方向，使其更平行于未解析的二维地形脊。
A new parametrization of drag arising from the flow over unresolved topography (UT) in a general‐circulation model (GCM) is presented. It is comprised of three principle components: a parametrization of the source spectrum and drag associated with freely propagating hydrostatic gravity waves in the absence of rotation, a parametrization of the drag associated with low‐level wave breaking, and a parametrization of low‐level drag associated with upstream blocking and lee‐vortex dynamics. Novel features of the scheme include: a new procedure for defining the UT in each GCM grid cell which takes account of the GCM resolution and includes only the scales represented by the parametrization scheme, a new method of representing the azimuthal distribution of vertical momentum flux by two waves whose direction and magnitude systematically vary with the flow direction and with the anisotropy of the UT in each GCM grid cell, and a new application of form drag in the lowest levels which can change the direction of the low‐level flow so that it is more parallel to unresolved two‐dimensional topographic ridges.