A Tropical Atmosphere Model with Moisture: Global Well-posedness and Relaxation Limit

TL;DR

This paper proves the global well-posedness of a tropical atmosphere model with moisture, and demonstrates its convergence to a limiting system as the relaxation parameter approaches zero, solving an open problem in the field.

Contribution

It establishes the global existence, uniqueness, and continuous dependence of solutions for a moisture-including tropical atmosphere model, and proves its convergence to a limiting system as the relaxation parameter tends to zero.

Findings

Global existence and uniqueness of strong solutions for the model.

Convergence of the system to a limiting system as relaxation parameter tends to zero.

Solution dependence on initial data with additional regularity.

Abstract

In this paper, we consider a nonlinear interaction system between the barotropic mode and the first baroclinic mode of the tropical atmosphere with moisture; that was derived in [Frierson, D.M.W.; Majda, A.J.; Pauluis, O.M.: Dynamics of precipitation fronts in the tropical atmosphere: a novel relaxation limit, Commum. Math. Sci., 2 (2004), 591-626.] We establish the global existence and uniqueness of strong solutions to this system, with initial data in $H^1$, for each fixed convective adjustment relaxation time parameter $\varepsilon>0$. Moreover, if the initial data enjoy slightly more regularity than $H^1$, then the unique strong solution depends continuously on the initial data. Furthermore, by establishing several appropriate $\varepsilon$-independent estimates, we prove that the system converges to a limiting system, as the relaxation time parameter $\varepsilon$ tends to zero, with convergence rate of the order $O(\sqrt\varepsilon)$. Moreover, the limiting system has a unique global strong solution, for any initial data in $H^1$, and such unique strong solution depends continuously on the initial data if the the initial data posses slightly more regularity than $H^1$. Notably, this solves the VISCOUS VERSION of an open problem proposed in the above mentioned paper of Frierson, Majda and Pauluis.