The Impact of Effective Buoyancy and Dynamic Pressure Forcing on Vertical Velocities within Two-Dimensional Updrafts
The Impact of Effective Buoyancy and Dynamic Pressure Forcing on Vertical Velocities within Two-Dimensional Updrafts
复制标题
有效浮力和动压力对二维上升气流中垂直速度的影响
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
J. Peters
中科院分区：
文献类型：
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作者：
J. Peters
摘要本文建立了考虑有效浮力和动压力梯度力的上升气流中垂直加速度dw/dt和垂直速度w的简单诊断表达式。有效浮力是非静水压力场中垂直梯度的静力分量。本文导出的诊断表达式表明，上升气流的有效浮力取决于上升气流内部相对于上升气流直接外围的空气的温度扰动的大小（而不是相对于任意的基本状态），上升气流的高宽长宽比，以及上升气流相对于垂直方向的倾斜度。诊断表达式在通过云模式模拟的上升气流对w垂直剖面的描述（忽略压力）方面比包裹理论（忽略压力）有了显著改进，并准确地诊断了上升气流中的最大垂直速度wmax。最大的改进是……
AbstractThis research develops simple diagnostic expressions for vertical acceleration dw/dt and vertical velocity w within updrafts that account for effective buoyancy and the dynamic pressure gradient force. Effective buoyancy is the statically forced component of the vertical gradient in the nonhydrostatic pressure field. The diagnostic expressions derived herein show that the effective buoyancy of an updraft is dependent on the magnitude of the temperature perturbation within an updraft relative to the air along the updraft’s immediate periphery (rather than relative to an arbitrary base state as in ), the updraft’s height-to-width aspect ratio, and the updraft’s slant relative to the vertical.The diagnostic expressions are significantly improved over parcel theory (where pressure forces are ignored) in their portrayal of the vertical profile of w through updrafts from a cloud model simulation and accurately diagnosed the maximum vertical velocity wmax within updrafts. The largest improvements to the ...