Thermal versus dynamical tropopause in upper‐tropospheric balanced flow anomalies
Thermal versus dynamical tropopause in upper‐tropospheric balanced flow anomalies
复制标题
对流层上层平衡流异常中的热对流层顶与动力对流层顶
DOI：
10.1002/qj.49712656215
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发表时间：
2000
影响因子：
8.9
通讯作者：
V. Wirth
中科院分区：
文献类型：
--
作者：
V. Wirth
本文系统地研究了热力对流层顶和动力对流层顶在对流层上层平衡气流异常中的差异。考虑了轴对称或平面对称的理想化气旋和反气旋反常。在给定位涡分布的情况下，用数值方法求解反演问题，得到相应的平衡流动(即风和温度)。控制参数是PV异常的纵横比，它控制着热力异常和动力异常的划分。对于中等高宽比和高纵横比的PV异常，热对流层顶的位置与动力对流层顶的位置明显不同。热对流层顶对于中等高宽比来说是相当模糊的，而对于高异常和浅异常来说，它是尖锐和清晰的。一个正压形变流场叠加在一个平面对称异常上，引起一个非地转风，它改变了整个PV异常的静力稳定性，使得热力和动力对流层的演变不同。根据目前的结果，可以一致地解释最近关于热对流层和臭氧对流层之间的相关性的观测结果。
This paper systematically investigates differences between the thermal and the dynamical tropopause for upper‐tropospheric balanced flow anomalies. Idealized cyclonic and anticyclonic anomalies are considered, which are either axisymmetric or plane symmetric. Given a distribution of potential vorticity (PV), the inversion problem is solved numerically to obtain the corresponding balanced flow (i.e. wind and temperature). The control parameter is the aspect ratio of the PV anomaly, which governs the partitioning into a thermal and a dynamical anomaly. For PV anomalies of intermediate and tall aspect ratios, the location of the thermal tropopause differs significantly from the location of the dynamical tropopause. The thermal tropopause is rather indistinct for intermediate aspect ratios, while it is sharp and well defined for both tall and shallow anomalies. A barotropic deformation flow field superimposed on a plane symmetric anomaly induces an ageostrophic wind which modifies the static stability throughout the PV anomaly such that the thermal and dynamical tropopauses evolve differently. Recent observations concerning the correlation between the thermal and ozone tropopauses can be interpreted consistently in terms of the present results.