Identifying Putative Microbial Drivers of Methane Flux on Earth and MarsMethane plays a critical role in climate change on Earth and observations of methane on Mars may suggest the presence of life. Understanding the relationship between subsurface microorganisms and methane in the Arctic will help predict the influence of climate change on methane concentrations in permafrost environments and inform our understanding of methane on Mars. The following are required to assess methane-microbe relationships: i) diversity and metabolic potential; ii) physical architecture and spa3al relationships between microorganisms and minerals, organic substances, and elements; iii) geochemical parameters of the environment. We will investigate three environments on Axel Heiberg Island: i) hypersaline cold spring hosted methane seeps (Colour Peak, Gypsum, and Wolf springs); ii) cryosols from polygonal terrain known to be both methane sources and sinks; and iii) glacial ice not known to be associated with methane release (Crown and White glaciers). We will test 4 prototype spectroscopy instruments to assess near surface methane in the atmosphere as well as mapping of organic molecules, minerals, and elements. Physical samples will also be acquired to assess the microbial community diversity and environmental geochemistry. Testing this instrumentation help with monitoring of remote ecosystems sensitive to environmental change and is also a crucial step in developing this instrumentation for future Mars missions.• Can new spectroscopy instruments be used to detect methane emissions from natural methane seeps and map organics, minerals, and elements?• What is the subsurface microbial community structure and near surface methane profile in each environment?• Are subsurface microbial communities capable of oxidizing methane and how do they influence methane cycling?Objective 1: Characterize the subsurface sediment-hosted microbial communities and their capacity for active methane oxidation demonstrating their significance to methane cycling.Objective 2: Characterize the near surface methane establishing a local record of methane flux linked to microbial methane oxidation rates.Field research (26/06/2023 – 31/07/2023) with active on Axel Heiberg Island based out of the McGill Arc3c Research Station (July 2 – 19). A pump will draw atmospheric samples into the methane spectrometer. The mapping spectroscopy instruments use non-destructive LEDs. The spectroscopy instruments pose no environmental hazards or risks. Manual scooping and sediment push cores (30-50 cm) will be used to collect <5 L of sediment. Manual syringes will be used to collect <2 L / spring of water from each site. Given the water refresh rate and seasonal re-modelling, no environmental damage or risk is anticipated. Hand coring will collect <3 meters of ice core and <1.5 m of cryosol. Given the low volumes and the summer glacial surface melt, no environmental damage or risk is anticipated. All instruments will operate using Li-ion batteries.Atmospheric, geochemical, and biological data will be stored on university servers, available on request. Published data will be publicly available through GitHub repositories or long-term databases such as NCBI. As funding for the project advances, we plan to hire local wilderness guides in addition to developing bi-directional outreach initiatives to share our science results with the Hamlet of Resolute Bay and other Nunavut residents through engaging with local SAO offices.