Environmental Research Letters (Jan 2021)
Active layer thickness as a function of soil water content
- Leah K Clayton,
- Kevin Schaefer,
- Michael J Battaglia,
- Laura Bourgeau-Chavez,
- Jingyi Chen,
- Richard H Chen,
- Albert Chen,
- Kazem Bakian-Dogaheh,
- Sarah Grelik,
- Elchin Jafarov,
- Lin Liu,
- Roger John Michaelides,
- Mahta Moghaddam,
- Andrew D Parsekian,
- Adrian V Rocha,
- Sean R Schaefer,
- Taylor Sullivan,
- Alireza Tabatabaeenejad,
- Kang Wang,
- Cathy J Wilson,
- Howard A Zebker,
- Tingjun Zhang,
- Yuhuan Zhao
Affiliations
- Leah K Clayton
- ORCiD
- Department of Earth and Planetary Sciences, Yale University , New Haven, CT, United States of America
- Kevin Schaefer
- ORCiD
- National Snow and Ice Data Center, Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder , Boulder, CO, United States of America
- Michael J Battaglia
- Michigan Tech Research Institute, Michigan Technological University , Ann Arbor, MI 48105, United States of America
- Laura Bourgeau-Chavez
- ORCiD
- Michigan Tech Research Institute, Michigan Technological University , Ann Arbor, MI 48105, United States of America
- Jingyi Chen
- ORCiD
- Department of Aerospace Engineering and Engineering Mechanics, Cockrell School of Engineering, The University of Texas at Austin , Austin, TX, United States of America
- Richard H Chen
- ORCiD
- Jet Propulsion Laboratory, California Institute of Technology , Pasadena, CA, United States of America
- Albert Chen
- ORCiD
- Department of Geophysics, Stanford University , Stanford, CA, United States of America
- Kazem Bakian-Dogaheh
- Department of Electrical and Computer Engineering, University of Southern California , Los Angeles, CA, United States of America
- Sarah Grelik
- Michigan Tech Research Institute, Michigan Technological University , Ann Arbor, MI 48105, United States of America
- Elchin Jafarov
- ORCiD
- Earth and Environmental Science Division, Los Alamos National Laboratory , Los Alamos, NM, United States of America
- Lin Liu
- ORCiD
- Earth System Science Programme, Faculty of Science, The Chinese University of Hong Kong , Hong Kong, Hong Kong
- Roger John Michaelides
- ORCiD
- Department of Geophysics, Colorado School of Mines , Golden, CO, United States of America
- Mahta Moghaddam
- Department of Electrical and Computer Engineering, University of Southern California , Los Angeles, CA, United States of America
- Andrew D Parsekian
- ORCiD
- Department of Geology and Geophysics, University of Wyoming , 1000 E University Ave., Laramie, WY, United States of America; Department of Civil and Architectural Engineering, University of Wyoming , 1000 E University Ave., Laramie, WY, United States of America
- Adrian V Rocha
- ORCiD
- Department of Biological Sciences and the Environmental Change Initiative, University of Notre Dame , Notre Dame, IN 46556, United States of America
- Sean R Schaefer
- ORCiD
- University of New Hampshire , Durham, NH, United States of America
- Taylor Sullivan
- Department of Geology and Geophysics, University of Wyoming , 1000 E University Ave., Laramie, WY, United States of America
- Alireza Tabatabaeenejad
- ORCiD
- Department of Electrical and Computer Engineering, University of Southern California , Los Angeles, CA, United States of America
- Kang Wang
- ORCiD
- East China Normal University , Shanghai 200241, People’s Republic of China
- Cathy J Wilson
- ORCiD
- Earth and Environmental Science Division, Los Alamos National Laboratory , Los Alamos, NM, United States of America
- Howard A Zebker
- Department of Geophysics, Stanford University , Stanford, CA, United States of America
- Tingjun Zhang
- ORCiD
- Key Laboratory of West China’s Environments (DOE), College of Earth and Environmental Sciences, Lanzhou University , Lanzhou 730000, People’s Republic of China
- Yuhuan Zhao
- Department of Electrical and Computer Engineering, University of Southern California , Los Angeles, CA, United States of America
- DOI
- https://doi.org/10.1088/1748-9326/abfa4c
- Journal volume & issue
-
Vol. 16,
no. 5
p. 055028
Abstract
Active layer thickness (ALT) is a critical metric for monitoring permafrost. How soil moisture influences ALT depends on two competing hypotheses: (a) increased soil moisture increases the latent heat of fusion for thaw, resulting in shallower active layers, and (b) increased soil moisture increases soil thermal conductivity, resulting in deeper active layers. To investigate their relative influence on thaw depth, we analyzed the Field Measurements of Soil Moisture and Active Layer Thickness (SMALT) in Alaska and Canada dataset, consisting of thousands of measurements of thaw depth and soil moisture collected at dozens of sites across Alaska and Canada as part of NASA’s Arctic Boreal Vulnerability Experiment (ABoVE). As bulk volumetric water content (VWC) integrated over the entire active layer increases, ALT decreases, supporting the latent heat hypothesis. However, as VWC in the top 12 cm of soil increases, ALT increases, supporting the thermal conductivity hypothesis. Regional temperature variations determine the baseline thaw depth while precipitation may influence the sensitivity of ALT to changes in VWC. Soil latent heat dominates over thermal conductivity in determining ALT, and the effect of bulk VWC on ALT appears consistent across sites.
Keywords
