Evolution of stratosphere-troposphere singular vectors
Evolution of stratosphere-troposphere singular vectors
复制标题
平流层-对流层奇异向量的演化
DOI：
10.1002/qj.786
复制
发表时间：
2011
影响因子：
8.9
通讯作者：
De Vries H
中科院分区：
文献类型：
--
作者：
De Vries H
平流层条件在不同的时间尺度上影响对流层环流。本文讨论了平流层-对流层相互作用中与长达一周的时间尺度相关的两个问题：所涉及的基本增长机制和平流层切变的作用。假设线性准地转动力学和简化的纬向流，对初始平流层扰动进行理想化模拟，以 5 天的前置时间最大化对流层总扰动能量。根据罗斯贝波的三个分量之间的基本相互作用来分析演化过程。在 f 平面（恒定科里奥利参数）上，三分量分析非常准确（误差保持在垂直积分总能量的 1% 以内），因为所有可用的生长机制都被捕获。能量增长最初通过奥尔机制发生，随后通过共振，最后通过（正态模式）剪切不稳定性发生。在β平面上（科里奥利参数随纬度线性变化），由于三分量模型忽略了倾斜位涡结构的西退，因此误差增加。进一步的研究表明，对流层能量增长很大程度上取决于平流层切变的值。版权所有 © 2011 英国皇家气象学会
Stratospheric conditions affect the tropospheric circulation on a variety of time‐scales. This article addresses two issues in stratosphere–troposphere interaction that are relevant for time‐scales up to a week: the basic growth mechanisms involved and the role of the stratospheric shear. Idealized simulations are conducted of initially stratospheric perturbations that maximize tropospheric total disturbance energy with a lead time of 5 days, assuming linear quasi‐geostrophic dynamics and simplified zonal flow. The evolution is analysed in terms of the basic interactions between three Rossby‐wave components. On thef‐plane (constant Coriolis parameter), the three‐component analysis is very accurate (the error stays within 1% of vertically integrated total energy) because all available growth mechanisms are captured. Energy growth occurs initially through the Orr mechanism, subsequently through resonance and finally through (normal‐mode) shear instability. On theβ‐plane (Coriolis parameter varying linearly with latitude), errors increase because westward retrogression of the untilting potential vorticity structure is neglected by the three‐component model. Further study reveals that the tropospheric energy growth strongly depends on the value of the stratospheric shear. Copyright © 2011 Royal Meteorological Society