Mars Methane Sources in Northwestern Gale Crater Inferred from Back-Trajectory Modeling

Creators: Luo, Y.; Mischna, M. A.; Lin, J. C.; Fasoli, B.; Cai, X.; Yung, Y. L.

Abstract

During its five years of operation as of 2017, the Sample Analysis at Mars (SAM) Tunable Laser Spectrometer (TLS) on board the Curiosity rover has detected six methane spikes above a low background abundance in Gale crater. The methane spikes are likely sourced by nearby emission from the surface. Here we use inverse Lagrangian modeling techniques to identify upstream emission regions on the Martian surface for these methane spikes at unprecedented spatial resolutions. Inside Gale crater, the northwestern crater floor casts the strongest influence on the detections. Outside Gale crater, the upstream regions extend towards the north. The contrasting results from two consecutive TLS methane measurements point to an active emission site to the west and the southwest of the Curiosity rover on the northwestern crater floor. The observed spike magnitude and frequency also favor emission sites on the northwestern crater floor, unless there are fast methane removal mechanisms at work, or either the TLS methane spikes or the Trace Gas Orbiter (TGO) non-detections can not be trusted.

Additional Information

The copyright holder for this preprint is the author/funder. Published Online: Tue, 20 Jul 2021. A portion of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. Government sponsorship acknowledged. Y. L. Y acknowledges the President's and Director's Research and Development Fund and the support from the Virtual Planetary Laboratory at the University of Washington that is funded via NASA Astrobiology Program Grant No. 80NSSC18K0829. Resources supporting this work were provided by the NASA High-End Computing (HEC) Program through the NASA Advanced Supercomputing (NAS) Division at Ames Research Center. A file that lists all the relevant conditions and parameters used in the MarsWRF simulations can be found at the CaltechDATA reposity via https://doi.org/10.22002/D1.2026. The original STILT model is available at its website https://uataq.github.io/stilt/#/. A list of modifications to the original STILT model based on the conditions of Mars can be found at the CaltechDATA repository via https://doi.org/10.22002/D1.2026. The STILT footprint files used to generate Figure 3–5 in this study are available at the CaltechDATA repository via https://doi.org/10.22002/D1.2025.

Attached Files

Submitted - essoar.10507550.1.pdf

Files

essoar.10507550.1.pdf

Files (21.9 MB)

Name	Size	Download all
essoar.10507550.1.pdf md5:f05db63b64da2866bf3a1fef0dd1ee10	21.9 MB	Preview Download

Additional details

	All versions	This version
Views	0	0
Downloads	0	0
Data volume	0 Bytes	0 Bytes