The teleconnection between the Quasi-Biennial Oscillation (QBO) and the Arctic polar vortex is investigated using Coupled Model Intercomparison Project 6 (CMIP6) models. Output from 14 CMIP6 models is compared with reanalysis, three experiments with prescribed QBOs, one of which has no free polar stratospheric variability, and transient experiments in which a QBO is prescribed in runs previously devoid of a QBO. Each CMIP6 model underestimates the Holton-Tan effect (HTE), the weakening of the polar vortex expected with QBO easterlies in the tropical lower stratosphere. To establish why, potential vorticity maps are used to investigate longitudinal variations in the teleconnection. Prescribing easterly QBO in the transient experiments promotes more high-latitude planetary wave breaking by influencing the mid-latitude stratospheric circulation, particularly over Asia. CMIP6 models that better simulate this response over Asia better simulate the HTE. These models also have stronger 10 hPa QBO westerlies.

中文翻译：

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CMIP6 模型低估了 Holton-Tan 效应

使用耦合模型比对项目 6 (CMIP6) 模型研究准双年振荡 (QBO) 和北极极地涡旋之间的遥相关。将 14 个 CMIP6 模型的输出与再分析、三个具有指定 QBO 的实验（其中一个没有自由极地平流层变异性）和瞬态实验进行比较，其中 QBO 在之前没有 QBO 的运行中被指定。每个 CMIP6 模型都低估了 Holton-Tan 效应 (HTE)，即热带低平流层 QBO 东风预计极地涡旋减弱。为了确定原因，使用潜在涡度图来研究遥相关的纵向变化。在瞬态实验中规定东风QBO通过影响中纬度平流层环流促进更多的高纬度行星波破碎，特别是在亚洲。CMIP6 模型可以更好地模拟亚洲的这种响应，可以更好地模拟 HTE。这些模型还具有更强的 10 hPa QBO 西风带。