Large uncertainty in permafrost carbon stocks due to hillslope soil deposits
Here, northern circumpolar permafrost soils contain more than a third of the global Soil Organic Carbon pool (SOC). The sensitivity of this carbon pool to a changing climate is a primary source of uncertainty in simulationbased climate projections. These projections, however, do not account for the...
| Published in: | Geophysical Research Letters |
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| Main Authors: | , , , , , , |
| Language: | unknown |
| Published: |
2021
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| Subjects: | |
| Online Access: | http://www.osti.gov/servlets/purl/1389639 https://www.osti.gov/biblio/1389639 https://doi.org/10.1002/2017GL073823 |
| Summary: | Here, northern circumpolar permafrost soils contain more than a third of the global Soil Organic Carbon pool (SOC). The sensitivity of this carbon pool to a changing climate is a primary source of uncertainty in simulationbased climate projections. These projections, however, do not account for the accumulation of soil deposits at the base of hillslopes (hill-toes), and the influence of this accumulation on the distribution, sequestration, and decomposition of SOC in landscapes affected by permafrost. Here we combine topographic models with soil-profile data and topographic analysis to evaluate the quantity and uncertainty of SOC mass stored in perennially frozen hill-toe soil deposits. We show that in Alaska this SOC mass introduces an uncertainty that is > 200% than state-wide estimates of SOC stocks (77 PgC), and that a similarly large uncertainty may also pertain at a circumpolar scale. Soil sampling and geophysical-imaging efforts that target hill-toe deposits can help constrain this large uncertainty. |
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