New insights into the Martian ozone deficit problem from an uncertainty propagation study
5 affiliations
- 1School of GeoSciences, The University of Edinburgh , Edinburgh ,
- 2Centre for Exoplanet Science, University of Edinburgh , Edinburgh ,
- 3LATMOS, CNRS, Sorbonne Université , UVSQ Université Paris-Saclay, Paris ,
- 4Laboratoire de Météorologie Dynamique/IPSL, Sorbonne Université, ENS, PSL Research University , École Polytechnique, CNRS, Paris ,
- 5University of Oxford Department of Physics, , Oxford ,
Abstract
Photochemical models of the Martian atmosphere have long suffered from a persistent “ozone deficit”. This discrepancy is typically attributed to missing physical or chemical processes, particularly involving odd-hydrogen chemistry. Here, we instead quantify the impact of uncertainties in chemical reaction kinetics on modelled ozone, which has received comparatively little attention. We perform a global sensitivity analysis using the 1-D configuration of the Mars Planetary Climate Model (MPCM) by perturbing all photochemical rates within their uncertainty ranges. Rank correlation coefficients (RCCs) are used to identify reactions that exert the strongest control on ozone variability. We find that reactions governing hydroxyl radical (OH) production and direct ozone loss dominate the anticorrelation with ozone, while oxygen-producing pathways are positively correlated. Several reactions involving the hydroperoxyl radical (HO2) and hydrogen peroxide (H2O2) that do not produce OH also contribute positively. Guided by these results, we implement targeted rate adjustments in the 3-D MPCM. These modifications produce systematic increases in ozone column densities and vertical mixing ratios across all seasons and latitudes, without perturbing the simulated water cycle. The resulting ozone fields show improved agreement with ACS MIR vertical profiles. Our results demonstrate that uncertainties in reaction kinetics can account for a substantial fraction of the ozone deficit, reducing the need to invoke additional processes, such as heterogeneous uptake on dust. We provide a list of key uncertainty reactions that should be prioritized in new lab campaigns under Mars conditions to improve model performance and better quantify biases before implementing new processes.
Related
- PROSERPINA: An Automated Pipeline for Martian Ionospheric Radio-occultation Retrievals with Probabilistic Uncertainty and Spherical-symmetry Bias Quantification
- Insights into the Micromechanical Properties of Different Planetary Bodies: Nanoindentation Studies of Martian Olivines and Pyroxenes
- Solar wind interaction with the Martian magnetosphere under a radial interplanetary magnetic field black in the subsolar region
- Physics-Informed Multi-Task Surrogate Model for the Martian Nightside Thermosphere
- Wave Mode-based Identification of Plasma Boundaries in the Martian Magnetosphere Using MAVEN Observations
BibTeX
@article{benne2026insights,
title = {{New insights into the Martian ozone deficit problem from an uncertainty propagation study}},
author = {Benjamin Benne and Paul I Palmer and Franck Lefèvre and Ehouarn Millour and Kevin S Olsen},
journal = {Monthly Notices of the Royal Astronomical Society},
year = {2026},
month = oct,
doi = {10.1093/mnras/stag1984},
url = {https://academic.oup.com/mnras/advance-article/doi/10.1093/mnras/stag1984/8965448},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - New insights into the Martian ozone deficit problem from an uncertainty propagation study
AU - Benjamin Benne
AU - Paul I Palmer
AU - Franck Lefèvre
AU - Ehouarn Millour
AU - Kevin S Olsen
PY - 2026
DA - 2026/10/21
JO - Monthly Notices of the Royal Astronomical Society
DO - 10.1093/mnras/stag1984
UR - https://academic.oup.com/mnras/advance-article/doi/10.1093/mnras/stag1984/8965448
AB - Photochemical models of the Martian atmosphere have long suffered from a persistent “ozone deficit”. This discrepancy is typically attributed to missing physical or chemical processes, particularly involving odd-hydrogen chemistry. Here, we instead quantify the impact of uncertainties in chemical reaction kinetics on modelled ozone, which has received comparatively little attention. We perform a global sensitivity analysis using the 1-D configuration of the Mars Planetary Climate Model (MPCM) by perturbing all photochemical rates within their uncertainty ranges. Rank correlation coefficients (RCCs) are used to identify reactions that exert the strongest control on ozone variability. We find that reactions governing hydroxyl radical (OH) production and direct ozone loss dominate the anticorrelation with ozone, while oxygen-producing pathways are positively correlated. Several reactions involving the hydroperoxyl radical (HO2) and hydrogen peroxide (H2O2) that do not produce OH also contribute positively. Guided by these results, we implement targeted rate adjustments in the 3-D MPCM. These modifications produce systematic increases in ozone column densities and vertical mixing ratios across all seasons and latitudes, without perturbing the simulated water cycle. The resulting ozone fields show improved agreement with ACS MIR vertical profiles. Our results demonstrate that uncertainties in reaction kinetics can account for a substantial fraction of the ozone deficit, reducing the need to invoke additional processes, such as heterogeneous uptake on dust. We provide a list of key uncertainty reactions that should be prioritized in new lab campaigns under Mars conditions to improve model performance and better quantify biases before implementing new processes.
SN - 0035-8711
SN - 1365-2966
ER -