Quasi-Biennial Oscillation (QBO)
Below you may download a Python code that implements a one-dimensional model of the QBO. The code solves the model of Plumb, and a simplification of the one of Lindzen and Holton. Specifically, there two upward propogating gravity waves, one with a positive and one with a negative phase speed. The waves dissipate as they ascend, and preferentially dissipate near a critical line where U = c. They deposit their momentum, which serves to accelerate the mean flow. This changes the position of the critical line, which then descends, and the pattern repeats itself in near-regular cycle, the quasi-biennial oscillation.
Sample PDF output: click to download
Code as zip file: click to download
Download Code itself, qbo.py.
Code: click to view
Download a code that makes a movie, qbo-movie.py.
Play the movie (very basic; we're not Hollywood here).
Download the movie.
This code is the same as qbo.py except that it makes a movie, qbo.mp4, of the output as it runs. The code requires ffmpeg to run.