Open AccessThree-phase numerical model for subsurface hydrology in permafrost-affected regions (PFLOTRAN-ICE v1.0)
Author(s) -
Satish Karra,
Scott Painter,
Peter C. Lichtner
Publication year - 2014
Publication title -
the cryosphere
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.574
H-Index - 82
eISSN - 1994-0424
pISSN - 1994-0416
DOI - 10.5194/tc-8-1935-2014
Subject(s) - permafrost , environmental science , biogeochemical cycle , component (thermodynamics) , soil water , hydrology (agriculture) , moisture , water content , arctic , diffusion , atmospheric sciences , soil science , geology , meteorology , geotechnical engineering , thermodynamics , chemistry , oceanography , physics , environmental chemistry
Degradation of near-surface permafrost due to changes in the climate isexpected to impact the hydrological, ecological and biogeochemical responsesof the Arctic tundra. From a hydrological perspective, it is important tounderstand the movement of the various phases of water (gas, liquid and ice)during the freezing and thawing of near-surface soils. We present a newnon-isothermal, single-component (water), three-phase formulation thattreats air as an inactive component. This single component model works welland produces similar results to a more complete and computationally demandingtwo-component (air, water) formulation, and is able to reproduce results ofpreviously published laboratory experiments. A proof-of-conceptimplementation in the massively parallel subsurface flow and reactive transportcode PFLOTRAN is summarized, and parallel performance of that implementationis demonstrated. When water vapor diffusion is considered, a large effect onsoil moisture dynamics is seen, which is due to dependence of thermalconductivity on ice content. A large three-dimensional simulation(with around 6 million degrees of freedom) of seasonal freezing and thawing isalso presented