Abstract:

Arctic soils are one of the largest terrestrial reservoirs of organic carbon. This carbon is climate-sensitive, and much effort has been made to investigate its release by establishing baselines for monitoring carbon dioxide (CO2) and methane (CH4) emissions from polar regions. Nitrous oxide (N2O), an ozone-depleting greenhouse gas with a global warming potential of 273 times that of CO2, has traditionally been considered negligible in Arctic ecosystems due to low nitrogen mineralization rates and intense competition for inorganic nitrogen. Recent studies suggest otherwise, indicating that the Arctic can be a significant source of N2O emissions, particularly in landforms resulting from permafrost thawing, such as thermokarst-affected areas with unvegetated surfaces. However, much remains unknown about these processes in polar regions. This NERTO project aims to investigate the spatial variability of greenhouse gas emissions (CO2, CH4, and N2O) from thermokarst-affected landscapes, particularly retrogressive thaw slumps across the North Slope of Alaska, via in situ measurements using interdisciplinary approaches. The results are from the NOAA EPP/MSI CSC NERTO graduate internship project, conducted under the guidance of NOAA mentor Bryan Thomas, Station Lead of NOAA’s Office of Oceanic and Atmospheric Research, Global Monitoring Laboratory – Barrow Atmospheric Baseline Observatory. The NERTO program deepened the intern’s understanding of Arctic emissions and thermokarst processes while strengthening their research skills in a collaborative environment. Given the global warming potential of these potent greenhouse gases, particularly N2O, which has been overlooked in Arctic ecosystems, and the vast amount of carbon stored in Arctic landforms, the results from the NERTO provide valuable ground observations on the patterns and controls of emissions across the region’s landscape, improving current models on the carbon budget and thereby contributing to climate resiliency, mitigation, and adaptation efforts, aligning with NOAA’s mission of science, service, and stewardship.