Abstract. The Control Volume; Permafrost Model (CVPM) is a modular heat-transfer modeling system designed; for scientific and engineering studies in permafrost terrain, and as an; educational tool. CVPM implements the nonlinear heat-transfer equations in; 1-D, 2-D, and 3-D Cartesian coordinates, as well as in 1-D radial and 2-D; cylindrical coordinates. To accommodate a diversity of geologic settings, a; variety of materials can be specified within the model domain, including; organic-rich materials, sedimentary rocks and soils, igneous and metamorphic; rocks, ice bodies, borehole fluids, and other engineering materials. Porous; materials are treated as a matrix of mineral and organic particles with pore; spaces filled with liquid water, ice, and air. Liquid water concentrations at; temperatures below 0 ∘C due to interfacial, grain-boundary, and; curvature effects are found using relationships from condensed matter; physics; pressure and pore-water solute effects are included. A radiogenic; heat-production term allows simulations to extend into deep permafrost and; underlying bedrock. CVPM can be used over a broad range of depth,; temperature, porosity, water saturation, and solute conditions on either the; Earth or Mars. The model is suitable for applications at spatial scales; ranging from centimeters to hundreds of kilometers and at timescales ranging; from seconds to thousands of years. CVPM can act as a stand-alone model or the; physics package of a geophysical inverse scheme, or serve as a component; within a larger Earth modeling system that may include vegetation, surface; water, snowpack, atmospheric, or other modules of varying complexity.;
