Quasi-equilibrium and Modeling Tropical Atmosphere Dynamics

By Johnny Lin

Presented at: Purdue University Department of Earth and Atmospheric Sciences, Guest lecture in EAS 534—Tropical Meterology, 20 Mar 2008, West Lafayette, IN.


Since its formulation by Arakawa and Schubert (1974), the quasi-equilibrium (Q-E) hypothesis has played a fundamental role in our ability to analyze the dynamics of the tropical atmospheric. In this talk we review the Q-E hypothesis, its implications, and recently proposed adjustments to the hypothesis. We describe an intermediate-level atmospheric model formulated using the Q-E hypothesis, the Quasi-Equilibrium Tropical Circulation Model (QTCM). This model provides reasonable simulations in the tropics but is easily diagnosed and computationally light. We discuss results from the QTCM regarding Madden-Julian Oscillation dynamics and stochastic convective parameterizations.

Updated: March 21, 2008. Author: Johnny Lin <email address>. This work is licensed under a Creative Commons Attribution-ShareAlike 2.0 License.