The mean annual temperature at the top of permafrost, the TTOP model, and the effect of unfrozen water

• Published in: Permafrost and Periglacial Processes
• Main Author: D. W. Riseborough
• Format: Article in Journal/Newspaper
• Language: unknown
• Subjects: permafrost
• Online Access: https://doi.org/10.1002/ppp.418

The effect of unfrozen water content on the thermal properties of the ground is discussed in the context of the TTOP model. In soils with a significant freezing characteristic the ratio of unfrozen and frozen conductivities is not single‐valued, which is an assumption of the TTOP model. Numerical simulations of the thermal regime for a range of fine‐grained soils are used to determine the effect of variable soil conductivity on the temperature at the top of permafrost. Results show that the temperature dependent conductivity function can be used with a temperature based on the surface freezing index to estimate an appropriate single value of the frozen conductivity for use in the TTOP model. Copyright © 2002 John Wiley & Sons, Ltd.