How Does Gravity Wave Intermittency Affect the Quasi-Biennial Oscillation (QBO)?

The quasi-biennial oscillation (QBO) is an organized pattern of equatorial winds in the Earth's stratosphere that affects the weather and climate of the entire planet. Understanding how the QBO will respond to climate change is challenging because complex climate simulations cannot resolve the smaller scale gravity waves that must be included to produce a realistic QBO. Instead, they use parameterized models for these gravity waves. However, these models are tuned to our current atmosphere, so they cannot predict the future behavior of the QBO. One reason that climate models need to be tuned is to account for the fact that gravity waves are generated intermittently in the troposphere. In this presentation, we will discuss how a hierarchy of simple models with different levels of complexity can be used to investigate the effect of gravity wave intermittency on the QBO. In particular, we will explore whether Ewetola and Esler's recent result (doi:10.1017/jfm.2024.418) that the effect of near-monochromatic intermittency on the amplitude and period of the QBO can be captured by a single intermittency parameter in the 1D stochastic Holton-Lindzen-Plumb (sHLP) model still holds for more complex models.