Vertical Temperature Profiles at Maximum Entropy Production with a Net Exchange Radiative Formulation

TL;DR

This paper introduces a thermodynamic variational principle to compute vertical temperature and convective flux profiles in the atmosphere, using a maximum entropy production approach with both idealized and realistic radiative schemes, including CO2 variation effects.

Contribution

It presents a novel method to determine atmospheric profiles by maximizing entropy production, offering an alternative to traditional convection parameterizations in climate models.

Findings

Profiles computed for gray atmosphere and Net Exchange Formulation radiative scheme.

Doubling CO2 affects temperature and flux profiles significantly.

Method provides a new perspective on atmospheric convection modeling.

Abstract

Like any fluid heated from below, the atmosphere is subject to vertical instability which triggers convection. Convection occurs on small time and space scales, which makes it a challenging feature to include in climate models. Usually sub-grid parameterizations are required. Here, we develop an alternative view based on a global thermodynamic variational principle. We compute convective flux profiles and temperature profiles at steady-state in an implicit way, by maximizing the associated entropy production rate. Two settings are examined, corresponding respectively to the idealized case of a gray atmosphere, and a realistic case based on a Net Exchange Formulation radiative scheme. In the second case, we are also able to discuss the effect of variations of the atmospheric composition, like a doubling of the carbon dioxide concentration.