Formula for a baroclinic adjustment theory of climate
Formula for a baroclinic adjustment theory of climate
复制标题
气候斜压调节理论的公式
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
A. Sutera
中科院分区：
文献类型：
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作者：
I. Bordi;A. Dell’Aquila;A. Speranza;A. Sutera
近年来，有人提出了斜压中性与中纬度对流层顶高度的关系理论。然而，GCM结果表明，理论对外部参数的依赖性与这些数值实验所显示的并不一致。本文提出了一个通过对流层顶修正对Eady波中性进行斜压调整的解析公式。这个公式考虑了平流层和地形的简单表示，大大地扩展了搜索者修正的理论，这些修正改变了斜压中性状态的对流层顶条件及其对外部参数的敏感性。特别是，地形引入了一个dependenceon对流层垂直风切变的中性条件。这一特征在其他假设对流层位涡梯度为零的背景状态的模式中是不存在的。此外，我们还表明，修正的中性条件对定义背景流的参数的敏感性可能与GCM模拟所显示的敏感性相似。
Recently, a theory relating baroclinic neutrality and midlatitudes tropopause height has beenproposed. However, GCM results have shown that the dependence of the theory on externalparameters is not consistent with that displayed by these numerical experiments. In the presentpaper we suggest an analytic formula for baroclinic adjustment to the neutrality of Eady wavesthrough tropopause modification. This formula extends considerably the abovementionedtheory by taking into account both a simple representation of the stratosphere and the topography.These modifications alter the tropopause condition for a baroclinically neutral stateand its sensitivity to the external parameters. In particular, the topography introduces a dependenceon the tropospheric vertical wind shear of the neutrality condition. This feature is notpresent in other models that assume a background state with a zero potential vorticity gradientin the troposphere.We show, furthermore, that the modified neutrality condition has sensitivitiesthat may resemble those displayed by GCM simulations, with respect to the parameters definingthe background flow.