Adapting an Earth Global Climate Model for a Modern-day Martian climate.

Mars climate modelling is essential for understanding the atmosphere of a planet with limited in-situ observations. Such research is crucial if humanity will ever hope to explore the red planet in the coming decades. There are already Global Climate Models (hereafter; GCMs) for Mars that are tackling this challenge, but there are still processes that are poorly understood or difficult to simulate, such as inter-annual dust storms or a dynamically-calculated CO₂ ice cycle which affects global pressure changes. In order to address these issues in current Mars modelling, we propose a GCM capable of reproducing similar results by using different parameterisation. This multi-faceted approach would be pivotal in tackling the aforementioned issues, in addition to providing validation of modelling techniques in extreme conditions. 

We adapt a highly-sophisticated and modular GCM, the Met Office Unified Model, currently routinely employed for weather and climate prediction on Earth, to the present climate of Mars. We detail the key climate processes driving Mars' atmosphere and how we characterise them, namely:

• Dust
• Orography
• Orbital parameters
• Atmospheric composition and pressure
• Atmospheric H₂O
• CO₂ ice

By incrementally adapting schemes already established and used extensively for Earth simulations, we can reproduce a comprehensive and complex climate model of Mars, whilst simultaneously assessing the significance of each process. To verify our model, we compare our GCM against in-situ data from the Viking landers and outputs from the LMD Mars GCM. Through this, we demonstrate how we are able to reproduce key processes in the Martian atmosphere across its seasons, between which conditions can vary greatly. We then speculate what processes still need implementation or refinement and the impact they may have on our current outputs. 

We will finish by detailing the remaining schemes to be implemented and how they might impact the output of our GCM, namely; a CO₂ ice scheme and atmospheric moisture. The implementation of these processes will further increase the validity and accuracy of our results. Potential future work would include investigating diurnal fluctuations or inter-annual phenomena. Our GCM and modelling methods would eventually aim to expand the capabilities of the wider Mars-modelling community, the benefits of which, will bring us closer to unlocking and understanding the intricacies of Mars' unique environment.