Arctic carbon in flux - greenhouse gas budgets in a permafrost watershed

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Throughout the Arctic, permafrost ecosystems are in transition. The Arctic landscape is responding to a warming climate with earlier snowmelt, longer growing seasons, permafrost degradation, and changes in vegetation, for example. All of these changes may impact Arctic carbon stores and fluxes of greenhouse gases of carbon dioxide (CO2) and methane (CH4) that could either mitigate or enhance climate change at a global scale. However, we are still uncertain if the Arctic is a sink or source for CO2 and CH4. My research program aims to answer this question for a low Arctic watershed in Canada's Northwest Territories. Our long-term CO2 flux measurements since 2004 suggest the tundra at Daring Lake, NT is a substantial CO2 sink in most years. However, we need to better understand how much of this carbon might be lost back to the atmosphere as CH4 and CO2 as it moves through aquatic pathways. Aquatic carbon fluxes are expected to be significant at these sites where frozen soil limits infiltration and directs water through the terrestrial ecosystems, into numerous streams and ponds and finally into Daring Lake itself. By contributing our data and findings to national and international synthesis studies, we will help improve estimates of the pan-Arctic's role in the global carbon cycle. Our results will also directly help improve Canada's climate change modeling efforts by developing and validating the land-surface scheme and carbon cycle models routinely coupled with Canada's Earth System Model. Improvements to these models' treatment of Arctic tundra will best achieve an understanding of how changes in Arctic functioning may influence future climate here in Canada and around the world. These predictions are needed for communities in Canada that must prepare to adapt to change in their environments and work to reduce greenhouse gas emissions.