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Detailed Reference Information |
Smerdon, J.E. and Stieglitz, M. (2006). Simulating heat transport of harmonic temperature signals in the Earth's shallow subsurface: Lower-boundary sensitivities. Geophysical Research Letters 33: doi: 10.1029/2006GL026816. issn: 0094-8276. |
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We assess the sensitivity of a subsurface thermodynamic model to the depth of its lower-boundary condition. Analytic solutions to the one-dimensional thermal diffusion equation demonstrate that boundary conditions imposed at shallow depths (2--20 m) corrupt the amplitudes and phases of propagating temperature signals. The presented solutions are for: 1) a homogeneous infinite half-space driven by a harmonic surface-temperature boundary condition, and 2) a homogeneous slab with a harmonic surface-temperature boundary condition and zero-flux lower-boundary condition. Differences between the amplitudes and phases of the two solutions range from 0 to almost 100%, depending on depth, frequency and subsurface thermophysical properties. The implications of our results are straightforward: the corruption of subsurface temperatures can affect model assessments of soil microbial activity, vegetation changes, freeze-thaw cycles, and hydrologic dynamics. It is uncertain, however, whether the reported effects will have large enough impacts on land-atmosphere fluxes of water and energy to affect atmospheric simulations. |
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Abstract |
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Keywords
Biogeosciences, Modeling, Cryosphere, Permafrost, Hydrology, Modeling, Mathematical Geophysics, Spectral analysis (3205, 3280), Atmospheric Processes, Land/atmosphere interactions (1218, 1631, 1843) |
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Publisher
American Geophysical Union 2000 Florida Avenue N.W. Washington, D.C. 20009-1277 USA 1-202-462-6900 1-202-328-0566 service@agu.org |
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