Multiple Equilibria in a Single-Column Model of the Tropical Atmosphere

TL;DR

This paper demonstrates that a single-column tropical atmosphere model with weak temperature gradient approximation can have multiple stable states, including convective and dry conditions, depending on initial moisture profiles.

Contribution

It reveals the existence of multiple equilibria in a simplified tropical atmosphere model, highlighting the importance of initial conditions in determining the state.

Findings

Model exhibits multiple stable equilibria.

Convection state depends on initial moisture.

Dry state persists without convection.

Abstract

A single-column model run under the weak temperature gradient approximation, a parameterization of large-scale dynamics appropriate for the tropical atmosphere, is shown to have multiple stable equilibria. Under conditions permitting persistent deep convection, the model has a statistically steady state in which such convection occurs, as well as an extremely dry state in which convection does not occur. Which state is reached depends on the initial moisture profile.