Potential Vorticity Budgets in the North Atlantic Ocean
Potential Vorticity Budgets in the North Atlantic Ocean
复制标题
北大西洋的潜在涡度预算
DOI：
10.1175/jpo-d-13-087.1
复制
发表时间：
2014
影响因子：
3.5
通讯作者：
W. Dewar
中科院分区：
文献类型：
--
作者：
B. Deremble;N. Wienders;W. Dewar
摘要本文着重研究北大西洋的位涡收支，重点是风驱动的副热带环流。由于PV是风驱动环流的关键动力变量，因此理解这些预算非常重要。PV是等密度线上的保守量，只能通过边界进入或离开，如横向地形或表面。后者通量的诊断和测试对PV含量的演变在等密度层。前者使用Bernoulli函数计算。基本的结果是发现所有的测试isopycnals，和PV的主要特征是回流，在表面或边界添加很少。密度坐标非常适合理解PV环流。提出了一种计算伯努利函数的新方法。伯努利函数是由一个简单的椭圆方程和解决方案表明PV平流的主要贡献。
AbstractThis paper focuses on potential vorticity (PV) budgets in the North Atlantic with an emphasis on the wind-driven subtropical gyre. Since PV is the key dynamical variable of the wind-driven circulation, these budgets are important to understand. PV is a conservative quantity on isopycnals and can only enter or exit through the boundaries, like the lateral topography or the surface. The latter fluxes are diagnosed and tested against the evolution of the PV content in an isopycnal layer. The former are computed using the Bernoulli function. The essential result is found for all the tested isopycnals, and the dominant feature of PV is recirculation, with very little added at the surface or the boundaries. Density coordinates are well suited to understanding PV circulation. A novel technique for computing the Bernoulli function is proposed. The Bernoulli function is governed by a simple elliptic equation and the solutions demonstrate the dominant contribution of PV advection.