Permafrost
Datasets here focus on the study of the Arctic permafrost. Permafrost is any type of ground—from soil to sediment to rock—that has been frozen continuously for a minimum of two years and as many as hundreds of thousands of years. Read more about this amazing phenomenon here.
Thaw depth and water table in the footprint of five eddy covariance tower sites, Alaskan Arctic
Brooks Range in Alaska (Source)
The Data
The Data
This dataset is brought to you by Kyle Arndt, Donatella Zona, Walter Oechel, and Josh Hashemi. The Principal Investigator, Donatella Zona (she/her), an American oceanographer. She is a professor of Oceanography and a marine microbiologist at the University of Washington. Her research interests include studies of cold adapted microbes in their relation to astrobiology, biotechnology, and bioremediation.
The full paper associated with this dataset is avalible here.
What we know
Cold seasons in Arctic ecosystems are increasingly important to the annual carbon balance of these vulnerable ecosystems. Arctic winters are largely harsh and inaccessible leading historic data gaps during that time. Until recently, cold seasons have been assumed to have negligible impacts on the annual carbon balance but as data coverage increases and the Arctic warms, the cold season has been shown to account for over half of annual methane (CH4) emissions and can offset summer photosynthetic carbon dioxide (CO2) uptake. Freeze–thaw cycle dynamics play a critical role in controlling cold season CO2 and CH4 loss, but the relationship has not been extensively studied.
What we found out
The researchers analyzed freeze–thaw processes through in situ CO2 and CH4 fluxes in conjunction with soil cores for physical structure and porewater samples for redox biogeochemistry. They found a movement of water toward freezing fronts in soil cores, leaving air spaces in soils, which allows for rapid infiltration of oxygen‐rich snow melt in spring as shown by oxidized iron in porewater. The snow melt period coincides with rising ecosystem respiration and can offset up to 41% of the summer CO2 uptake.