A modern-day Mars climate in the Met Office Unified Model: dry simulations

TL;DR

This study adapts the Met Office Unified Model, an Earth climate model, to simulate a dry Martian climate, comparing dust radiative effects and validating results against an established Mars model.

Contribution

It demonstrates the adaptation of an Earth GCM for Mars climate simulation and compares its performance with an existing Mars model.

Findings

Radiative dust effects accelerate winds and create a mid-altitude isothermal layer.

Model shows good agreement with existing Mars model in wind and temperature profiles.

Discrepancies observed in dust mixing ratio and polar conditions.

Abstract

We present results from the Met Office Unified Model (UM), a world-leading climate and weather model, adapted to simulate a dry Martian climate. We detail the adaptation of the basic parameterisations and analyse results from two simulations, one with radiatively active mineral dust and one with radiatively inactive dust. These simulations demonstrate how the radiative effects of dust act to accelerate the winds and create a mid-altitude isothermal layer during the dusty season. We validate our model through comparison with an established Mars model, the Laboratoire de M\'et\'eorologie Dynamique planetary climate model (PCM), finding good agreement in the seasonal wind and temperature profiles but with discrepancies in the predicted dust mass mixing ratio and conditions at the poles. This study validates the use of the UM for a Martian atmosphere, highlighting how the adaptation of an Earth general circulation model (GCM) can be beneficial for existing Mars GCMs and provides insight into the next steps in our development of a new Mars climate model.