title: Water and heat transport in boreal soils: implications for soil response to climate change.
abstract: Soil water content strongly affects permafrost dynamics by changing the soil thermal properties. However, the movement of liquid water, which plays an important role in the heat transport of temperate soils, has been under-represented in boreal studies. Two different heat transport models with and without convective heat transport were compared to measurements of soil temperatures in four boreal sites with different stand ages and drainage classes. Overall, soil temperatures during the growing season tended to be over-estimated by 2-4°C when movement of liquid water and water vapor was not represented in the model. The role of heat transport in water has broad implications for site responses to warming and suggests reduced vulnerability of permafrost to thaw at drier sites. This result is consistent with field observations of faster thaw in response to warming in wet sites compared to drier sites over the past 30 years in Canadian boreal forests. These results highlight that representation of water flow in heat transport models is important to simulate future soil thermal or permafrost dynamics under a changing climate.
authors.affiliation: Department of Geological Sciences, University of Colorado, Boulder, CO 80305, USA. fanz@colorado.edu
authors.forename: Zhaosheng
authors.initials: Z
authors.lastname: Fan
authors.forename: Jason C
authors.initials: JC
authors.lastname: Neff
authors.forename: Jennifer W
authors.initials: JW
authors.lastname: Harden
authors.forename: Tingjun
authors.initials: T
authors.lastname: Zhang
authors.forename: Hugo
authors.initials: H
authors.lastname: Veldhuis
authors.forename: Claudia I
authors.initials: CI
authors.lastname: Czimczik
authors.forename: Gregory C
authors.initials: GC
authors.lastname: Winston
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: O'Donnell
mesh_terms: D057231:Climate Change; D003081:Cold Climate; D004777:Environment; D005618:Fresh Water / Q000737:chemistry*; D006358:Hot Temperature; D012987:Soil / Q000737:chemistry*; D014872:Water Movements
chemical_list: D012987:Soil