Laboratory Analogue of the Quasi-Biennial Oscillation

在赤道平流层。在5-100 hPa和15 N-15 S之间，主要的变率来源是一种交替的东、西风下降模式，称为准两年一次振荡（QBO）。这些纬向风的周期在22至34个月之间交替，平均为28个月。QBO对长期预报具有重要意义，因为它直接和间接地影响各种现象，包括平流层极地涡旋（Baldwin et al., 2021）、亚热带和中纬度急流（Kidston et al., 2015）以及包括MJO在内的热带对流（Son et al., 2017）。一般来说，偏东的QBO增加了弱中纬度急流、平流层突然变暖和英国冬季寒冷的机会，而偏西的QBO增加了强急流和温和但多风暴的英国冬季的机会。在赤道对流层顶产生的开尔文波、罗斯重力波和较短间隔的重力波通过平流层向上传播，相关的波-平均流相互作用产生振荡模式。对这些基本机制的理解已有许多理论框架，但目前仍有许多突出问题有待解决。QBO的行为及其潜在机制也与其他行星的大气有关。在木星（Li and Read, 2000）和土星（Fouchet et al., 2008）上也观察到类似的振荡（提出了类似的问题）。

In the equatorial stratosphere. between 5-100 hPa and 15 N-15 S, the dominant source of variability is an alternating pattern of descending eastward and westward wind regimes known as the Quasi-Biennial Oscillation (QBO). These zonal winds alternate with a period that varies between 22 and 34 months, averaging 28 months. The QBO is of significant interest to long term forecasting due to its direct and indirect influence on a wide range of phenomena including the stratospheric polar vortex (Baldwin et al., 2021), subtropical and midlatitude jet (Kidston et al., 2015), and tropical convection including the MJO (Son et al., 2017). Generally, an easterly QBO increases the chances of a weak midlatitude jet, sudden stratospheric warmings, and cold winters in the UK, while a westerly QBO increases the chances of a stronger jet and milder but stormier UK winters. Kelvin, Rossby-gravity, and shorter-length interval gravity waves produced at the equatorial tropopause propagate upwards through the stratosphere, and the associated wave-mean flow interaction generates the oscillating pattern. There is much existing theoretical framework for understanding these fundamental mechanisms, but there are many outstanding problems in current outstanding. The behaviour of the QBO and its underlying mechanisms is also relevant to the atmosphere of other planets. Similar oscillations (which pose similar questions) are observed on Jupiter (Li and Read, 2000) and Saturn (Fouchet et al., 2008).