Quasi-equilibrium and Modeling Tropical Atmosphere Dynamics

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

Abstract

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.