Meridional Rossby Wave Generation and Propagation in the Maintenance of the Wintertime Tropospheric Double Jet
Meridional Rossby Wave Generation and Propagation in the Maintenance of the Wintertime Tropospheric Double Jet
复制标题
冬季对流层双急流维持中的经向罗斯贝波的产生和传播
DOI：
--
复制
发表时间：
2016
期刊：
影响因子：
--
通讯作者：
G. Vallis
中科院分区：
文献类型：
--
作者：
Amanda K. O’Rourke;G. Vallis
涡动急流和副热带急流是中纬度对流层上层环流的两个动力学特征，它们常常合并成一个纬向风极大值。尽管如此，在大气中存在明显的双喷流状态的可能性，特别是在冬季半球，并呈现出独特的带状平均流，具有两个波导和一个具有减弱的位涡梯度的喷流间区域，Rossby波可以在其上产生，传播，反射，作者研究了两组大气波的相互作用-波长长于和短于变形半径的波-在理想大气模型中的双射流平均流内。长、短波的涡动动量通量辐合模式差别很大。短波的行为遵循经典的斜压不稳定性理论，其涡动动量通量辐合集中在涡动驱动的急流核心。另一方面，长波揭示了强烈的涡流动量流。
AbstractThe eddy-driven and subtropical jets are two dynamically distinct features of the midlatitude upper-troposphere circulation that are often merged into a single zonal wind maximum. Nonetheless, the potential for a distinct double-jet state in the atmosphere exists, particularly in the winter hemisphere, and presents a unique zonal-mean flow with two waveguides and an interjet region with a weakened potential vorticity gradient upon which Rossby waves may be generated, propagate, reflect, and break.The authors investigate the interaction of two groups of atmospheric waves—those with wavelengths longer and shorter than the deformation radius—within a double-jet mean flow in an idealized atmospheric model. Patterns of eddy momentum flux convergence for long and short waves differ greatly. Short waves behave following classic baroclinic instability theory such that their eddy momentum flux convergence is centered at the eddy-driven jet core. Long waves, on the other hand, reveal strong eddy momentum fl...