A radiative-convective model based on constrained maximum entropy production

Abstract

The representation of atmospheric convection induced by radiative forcing is a long-standing question mainly because turbulence plays a key role in the transport of energy as sensible heat, geopotential, and latent heat. Recent works have tried using the maximum entropy production (MEP) conjecture as a closure hypothesis in 1-D simple climate models to compute implicitly temperatures and the vertical energy flux. However, these models fail to reproduce realistic profiles. To solve the problem, we describe the energy fluxes as a product of a positive mass mixing coefficient with the corresponding energy gradient. This appears as a constraint which imposes the direction and/or limits the amplitude of the energy fluxes. It leads to a different MEP steady state which naturally depends on the considered energy terms in the model. Accounting for this additional constraint improves the results. Temperature and energy flux are closer to observations, and we reproduce stratification when we consider the geopotential. Variations in the atmospheric composition, such as a doubling of the carbon dioxide concentration, are also investigated.