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Title: 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 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.
ORCiD logo [1] ; ORCiD logo [2] ; ORCiD logo [2] ; ORCiD logo [3] ; ORCiD logo [4] ; ORCiD logo [2] ; ORCiD logo [5]
  1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Univ. of Pittsburgh, Pittsburgh, PA (United States)
  2. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  3. Stanford Univ., Stanford, CA (United States)
  4. Argonne National Lab. (ANL), Lemont, IL (United States)
  5. Univ. of Alaska, Fairbanks, AK (United States)
Publication Date:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Geophysical Research Letters
Additional Journal Information:
Journal Volume: 44; Journal Issue: 12; Journal ID: ISSN 0094-8276
American Geophysical Union
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
Country of Publication:
United States
58 GEOSCIENCES; hillslope; soil-Carbon; permafrost; soil-transport
OSTI Identifier: