Sponsor
Research supported by NSF project OPP-0423595, the McMurdo LTER.
Published In
Antarctic Science
Document Type
Article
Publication Date
1-1-2010
Subjects
McMurdo Dry Valleys (Antarctica), Antarctica -- Environmental conditions, McMurdo Dry Valleys (Antarctica) -- Soil temperature -- Models
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.
DOI
10.1017/S0954102010000234
Persistent Identifier
http://archives.pdx.edu/ds/psu/7383
Citation Details
H.W. Hunt, A.G. Fountain, P.T. Doran and H. Basagic (2010). A dynamic physical model for soil temperature and water in Taylor Valley, Antarctica. Antarctic Science, 22, pp 419-434 doi:10.1017/S0954102010000234
Description
Copyright 2010 Antarctic Science Ltd.
The original publication is available at http://journals.cambridge.org.