A dynamic physical model for soil temperature and water in Taylor Valley, Antarctica.

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TitleA dynamic physical model for soil temperature and water in Taylor Valley, Antarctica.
Publication TypeJournal Article
Year of Publication2010
AuthorsHunt, HW, Fountain, AG, Doran, PT, Basagic, HJ
JournalAntarctic Science
Issue22
Pagination419-434
Date Published05/13/2010
Type of ArticleJournal
Abstract

We developed a simulation model for terrestrial sites including sensible heat exchange between the atmosphere and ground surface, inter- and intra-layer heat conduction by rock and soil, and shortwave and longwave radiation. Water fluxes included snowmelt, freezing/thawing of soil water, soil capillary flow, and vapour flows among atmosphere, soil, and snow. The model accounted for 96–99% of variation in soil temperature data. No long-term temporal trends in soil temperature were apparent. Soil water vapour concentration in thawed surface soil in summer often was higher than in frozen deeper soils, leading to downward vapour fluxes. Katabatic winds caused a reversal of the usual winter pattern of upward vapour fluxes. The model exhibited a steady state depth distribution of soil water due to vapour flows and in the absence of capillary flows below the top 0.5 cm soil layer. Beginning with a completely saturated soil profile, soil water was lost rapidly, and within a few hundred years approached a steady state characterized by dry soil (< 0.5% gravimetric) down to one metre depth and saturated soil below that. In contrast, it took 42 000 years to approach steady state beginning from a completely dry initial condition.

DOI10.1017/S0954102010000234