Gravity Waves in Shear and Implications for Organized Convection
Gravity Waves in Shear and Implications for Organized Convection
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剪切重力波及其对有组织对流的影响
DOI：
10.1175/2009jas2976.1
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发表时间：
2009
影响因子：
3.1
通讯作者：
A. Majda
中科院分区：
文献类型：
--
作者：
S. Stechmann;A. Majda
摘要 众所周知，对流层中的重力波经常被先前存在的对流激发，可以促进或抑制新对流的形成。这里表明，在存在风切变或正压风的情况下，重力波可以在预先存在的对流的一侧比另一侧创造更有利的环境。这里建立的非线性和线性分析模型都表明，两侧之间最大的有利性差异是由急流切变造成的，而低层有切变而对流层上部没有切变的风廓线造成的有利性差异很小或没有。非零正压风（或者等效地，传播热源）也被证明会影响预先存在的对流两侧的有利性。结果表明，线性理论捕捉到了这些主要特征，背景风的平流是起作用的主要物理机制。这些过程应该在组织中发挥重要作用......
Abstract It is known that gravity waves in the troposphere, which are often excited by preexisting convection, can favor or suppress the formation of new convection. Here it is shown that in the presence of wind shear or barotropic wind, the gravity waves can create a more favorable environment on one side of preexisting convection than the other side. Both the nonlinear and linear analytic models developed here show that the greatest difference in favorability between the two sides is created by jet shears, and little or no difference in favorability is created by wind profiles with shear at low levels and no shear in the upper troposphere. A nonzero barotropic wind (or, equivalently, a propagating heat source) is shown to also affect the favorability on each side of the preexisting convection. It is shown that these main features are captured by linear theory, and advection by the background wind is the main physical mechanism at work. These processes should play an important role in the organization of...