A QBO Cookbook

1 minute read


Please see our new paper providing a recipe for generating and optimizing a Quasi-Biennial Oscillation in your very own GCM, just submitted to JAMES.

The most prominent mode of variability in the tropical stratosphere is the quasi-biennial oscillation (QBO), however only relatively recently have comprehensive models begun to simulate a QBO spontaneously, and even in these models the representation of the QBO typically suffers from biases. Here we elucidate the sensitivities of the QBO to a wide range of model parameters, and explore how these parameters affect the QBO behavior. We expect that these results will be helpful for tuning of more comprehensive models.

The paper, led by Chaim Garfinkel, explores the QBO in MiMA, an idealized atmospheric model developed in my group a few years back. Martin Jucker’s postdoctoral work keeps paying dividends!

The Key Points:

  • The sensitivity of the QBO to resolution, dissipation, wave forcing, and parameterized gravity waves is explored in a single framework.
  • The QBO period can be tuned independently of its amplitude, but the vertical structure (particularly at lower levels) is harder to capture.
  • The influence of factors on the QBO can be related to their impact on wave-induced momentum fluxes in the deep tropics.