Effects of Tropospheric Vertical Wind Shear on Gravity Waves Generated by Tropical Cyclones
Effects of Tropospheric Vertical Wind Shear on Gravity Waves Generated by Tropical Cyclones
复制标题
对流层垂直风切变对热带气旋产生的重力波的影响
DOI：
10.1029/2019gl082085
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发表时间：
2019
影响因子：
5.2
通讯作者：
Guan Jiping
中科院分区：
文献类型：
--
作者：
Wang Yuan;Zhang Lifeng;Zhang Yun;Guan Jiping
本研究使用不同环境纬向风垂直廓线的理想化热带气旋模拟，探讨对流层垂直风切变对热带气旋产生的重力波的影响。研究发现，在没有切变的情况下，重力波动量通量在很宽的谱范围内均匀分布，相反方向的动量通量呈对称性。对流层中的西风切变导致东向和向西向动量通量之间的不对称，从而导致净向西通量和由此产生的对平流层下部背景流的向西阻力强迫。在西风切变作用下，活跃动量通量向短水平波长方向扩展，向长周期、慢相速方向收缩。此外，清晰的本地峰值出现在大的水平波长，长周期，和中等的相速度，特别是向西的动量通量。
This study investigates the effects of tropospheric vertical wind shear on gravity waves generated by tropical cyclones using idealized tropical cyclone simulations with different vertical profiles of environmental zonal wind. It is found that without shear, gravity wave momentum fluxes are distributed uniformly over a broad spectral range, with fluxes in opposite directions showing symmetry. Westerly shear in the troposphere leads to asymmetry between eastward and westward momentum fluxes, resulting in net westward fluxes and a resultant westward drag forcing on the background flow in the lower stratosphere. Under westerly shear, the active momentum fluxes extend to shorter horizontal wavelengths, and contract to longer periods and slower phase speeds. In addition, clear local peaks appear at large horizontal wavelengths, long periods, and moderate phase speeds, particularly for westward momentum fluxes.