Long-Lived Mesoscale Systems in a Low–Convective Inhibition Environment. Part II: Downshear Propagation
Long-Lived Mesoscale Systems in a Low–Convective Inhibition Environment. Part II: Downshear Propagation
复制标题
低对流抑制环境中的长寿命中尺度系统第二部分：下切变传播。
DOI：
10.1175/jas-d-15-0073.1
复制
发表时间：
2015
影响因子：
3.1
通讯作者：
T. Lane
中科院分区：
文献类型：
--
作者：
M. Moncrieff;T. Lane
在热带环境中的长寿命对流系统的研究的第二部分的重点是前倾，下切传播系统，自发出现理想化的数值模拟。这些系统在重要方面不同于标准的中尺度对流系统，其特征是具有拖尾层状区域的后倾环流，翻转上升气流和中尺度下沉气流。与此标准的中尺度系统相反，这里考虑的下切变传播系统不具有中尺度下沉气流，虽然有一个冷池，但它对系统的传播和维持是次要的。中尺度下沉气流被一个升高的、前倾的翻转上升气流下的水跃式上升所取代，对流可用势能可以忽略不计。因此，中尺度环流几乎完全是由水平气压梯度所作的功和来自大气的动能维持的。
AbstractPart II of this study of long-lived convective systems in a tropical environment focuses on forward-tilted, downshear-propagating systems that emerge spontaneously from idealized numerical simulations. These systems differ in important ways from the standard mesoscale convective system that is characterized by a rearward-tilted circulation with a trailing stratiform region, an overturning updraft, and a mesoscale downdraft. In contrast to this standard mesoscale system, the downshear-propagating system considered here does not feature a mesoscale downdraft and, although there is a cold pool it is of secondary importance to the propagation and maintenance of the system. The mesoscale downdraft is replaced by hydraulic-jump-like ascent beneath an elevated, forward-tilted overturning updraft with negligible convective available potential energy. Therefore, the mesoscale circulation is sustained almost entirely by the work done by the horizontal pressure gradient and the kinetic energy available from ...