# Linearized Flux Evolution (LiFE): A Technique for Rapidly Adapting Fluxes from Full-Physics Radiative Transfer Models

## TL;DR

The paper introduces the Linearized Flux Evolution (LiFE) method, which efficiently adapts radiative flux profiles from full-physics models to changing atmospheric conditions, enhancing climate model versatility and speed.

## Contribution

LiFE provides a novel linearized approach to rapidly update radiative fluxes using derivatives from full-physics radiative transfer models, applicable to multiple planetary atmospheres.

## Key findings

- LiFE accurately reproduces full-physics fluxes with high efficiency.
- The method effectively adapts flux profiles for Mars, Earth, and Venus.
- LiFE aids in determining thermal structures in atmospheric models.

## Abstract

Solar and thermal radiation are critical aspects of planetary climate, with gradients in radiative energy fluxes driving heating and cooling. Climate models require that radiative transfer tools be versatile, computationally efficient, and accurate. Here, we describe a technique that uses an accurate full-physics radiative transfer model to generate a set of atmospheric radiative quantities which can be used to linearly adapt radiative flux profiles to changes in the atmospheric and surface state -- the Linearized Flux Evolution (LiFE) approach. These radiative quantities describe how each model layer in a plane-parallel atmosphere reflects and transmits light, as well as how the layer generates diffuse radiation by thermal emission and by scattering light from the direct solar beam. By computing derivatives of these layer radiative properties with respect to dynamic elements of the atmospheric state, we can then efficiently adapt the flux profiles computed by the full-physics model to new atmospheric states. We validate the LiFE approach, and then apply this approach to Mars, Earth, and Venus, demonstrating the information contained in the layer radiative properties and their derivatives, as well as how the LiFE approach can be used to determine the thermal structure of radiative and radiative-convective equilibrium states in one-dimensional atmospheric models.