The mass flux across the tropopause: Quasi‐geostrophic theory
The mass flux across the tropopause: Quasi‐geostrophic theory
复制标题
穿过对流层顶的质量通量：准地转理论
DOI：
10.1002/qj.49712353703
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发表时间：
1997
影响因子：
8.9
通讯作者：
M. Juckes
中科院分区：
文献类型：
--
作者：
M. Juckes
对流层平均经向环流是由与斜压波相关的涡动量通量驱动的。这些波的动力学可以用准地转理论定性地描述。在这里，使用f平面准地转理论模拟了风暴路径附近的气流，对流层顶表示为一个接近水平的表面，将具有均匀位涡度的对流层与同样均匀的平流层分开。结合对与衰减涡旋相关的平均经向质量通量和在同一过程中产生的对流层顶质量通量的分析，可以在纬向平均和准拉格朗日平均框架中估计净通量。拟拉格朗日平均值在这里被定义为对流层顶沿潜在温度等高线的平均值。与早期的数值和观测研究相一致，纬向平均质量通量是向上的，而准拉格朗日平均是向下的。
The mean meridional circulation in the troposphere is driven by eddy momentum fluxes associated with baroclinic waves. the dynamics of these waves can be described qualitatively by quasi‐geostrophic theory. Here, the flow in the vicinity of the storm tracks is modelled using f‐plane quasi‐geostrophic theory with the tropopause represented as a nearly horizontal surface separating a troposphere of uniform potential vorticity from a similarly uniform stratosphere. Combining an analysis of the mean meridional mass‐flux associated with decaying eddies and the cross‐tropopause mass‐flux generated in the same process, it is possible to estimate the net flux both in the zonal mean and in a quasi‐Lagrangian mean framework. the quasi‐Lagrangian mean is here defined as an average along potential temperature contours on the tropopause. Consistent with earlier numerical and observational studies, it is found that the zonal mean mass‐flux is upwards poleward of the jet, whereas the quasi‐Lagrangian mean is downwards.