EOS: Atmospheric Radiative Transfer in Habitable Worlds with HELIOS

TL;DR

EOS is a fast, GPU-accelerated radiative transfer tool adapted for terrestrial habitable planets, enabling efficient climate modeling and atmospheric characterization of exoplanets with results comparable to traditional codes.

Contribution

The paper introduces EOS, a GPU-optimized radiative transfer code adapted for rocky, habitable planets, offering at least ten times faster calculations than traditional CPU-based codes.

Findings

EOS produces results consistent with other RT codes.

EOS is at least an order of magnitude faster than CPU-based codes.

EOS accurately reproduces Earth's measured fluxes in climate models.

Abstract

We present EOS, a procedure for determining the Outgoing Longwave Radiation (OLR) and top-of-atmosphere (TOA) albedo for a wide range of conditions expected to be present in the atmospheres of rocky planets with temperate conditions. EOS is based on HELIOS and HELIOS-K, which are novel and publicly available atmospheric radiative transfer (RT) codes optimized for fast calculations with GPU processors. These codes were originally developed for the study of giant planets. In this paper we present an adaptation for applications to terrestrial-type, habitable planets, adding specific physical recipes for the gas opacity and vertical structure of the atmosphere. To test the reliability of the procedure we assessed the impact of changing line opacity profile, continuum opacity model, atmospheric lapse rate and tropopause position prescriptions on the OLR and the TOA albedo. The results obtained with EOS are in line with those of other RT codes running on traditional CPU processors, while being at least one order of magnitude faster. The adoption of OLR and TOA albedo data generated with EOS in a zonal and seasonal climate model correctly reproduce the fluxes of the present-day Earth measured by the CERES spacecraft. The results of this study disclose the possibility to incorporate fast RT calculations in climate models aimed at characterizing the atmospheres of habitable exoplanets.