Prof Rose Cory (left) and her group just returned from a summer field season in the Alaskan Arctic. Cory and her group are studying biogeochemical processes across permafrost soils that are important in the global carbon cycle as part of Cory’s recently awarded CAREER grant. Permafrost soils store about 17 billion tonnes of carbon; that is twice the amount of carbon in the atmosphere today. Frozen for thousands of years, the organic carbon in permafrost soils has not been participating in the modern active carbon cycle. But the Arctic is warming faster than any place on Earth, causing thawing of permafrost soils. Once thawed, the organic carbon in previously frozen permafrost soils can be converted to CO2, a greenhouse gas, which then be released to the atmosphere, causing a positive feedback loop that could amplify global climate change. Cory and her group are studying how and how fast this soil organic carbon can be converted to CO2.
PhD student Adrianna Trusiak (left) is investigating a novel, abiotic (redox) reaction mediated by iron that may lead to the conversion of soil carbon to CO2. In the photo, Adrianna and Rose are collecting soil water from the tundra, quantifying the dissolved iron and organic carbon present, and then testing how redox reactions of iron may control the oxidation of the organic carbon to CO2. They are the first to study this process in natural soils and waters, and have found that iron is playing a key role in this abiotic process that is important for carbon cycling on a landscape scale across the Arctic.