Determination of Soil Apparent Thermal Diffusivity From Multiharmonic Temperature Analysis for Nonuniform Soils

Nassar, I. N.; Horton, Robert

doi:10.1097/00010694-199003000-00001

Cited by 17 publications

(33 citation statements)

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“…It becomes

where D = k / C V is the thermal diffusivity. Most Fourier‐derived methods based on the attenuation and phase lag of temperature waves derive from equation (3) and rely on this assumption of globally constant thermal properties [e.g., DeVries , 1963; Carson , 1963; Nassar and Horton , 1990]. In real situations, thermal properties invariably do vary with depth.…”

Section: Analysis Methodsmentioning

confidence: 99%

Depth and seasonal variations in the thermal properties of Antarctic Dry Valley permafrost from temperature time series analysis

et al. 2003

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[1] We present the first dedicated study of the thermal properties of perennially frozen, ice-cemented, subsurface Dry Valley permafrost. From time series analysis of 14 months' temperature measurements, we resolve depth and seasonal variations in the thermal properties at two nearby sites at Table Mountain with different origin, composition, and polygonal ground patterning. We determine apparent thermal diffusivity (ATD) profiles directly from thermistor array measurements at 13.5-cm-depth intervals and 4-hour time intervals in the top 2 m. We treat the system as purely conductive year round due to the cold temperatures and compare the performance of several common analysis schemes with a graphical finite difference method that we present in detail. This comparison is facilitated by one site showing strong depth variations including an abrupt twofold increase in ATD across a sharp compositional boundary. We characterize the composition of the inhomogeneous ground from recovered cores and estimate an ice-fractiondependent heat capacity in the range C = 1.7 ± 0.1 to 1.8 ± 0.1 MJ m À3°CÀ1 . We calculate apparent thermal conductivity profiles that correlate very well with the core compositions. The conductivity generally lies in the range 2.5 ± 0.5 W m À1°CÀ1 but is as high as 4.1 ± 0.4 W m À1°CÀ1 for a quartose Sirius sandstone unit at one site. The seasonal variation in the ATD is consistent with its expected temperature dependence.

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“…It becomes

Section: Analysis Methodsmentioning

confidence: 99%

Depth and seasonal variations in the thermal properties of Antarctic Dry Valley permafrost from temperature time series analysis

et al. 2003

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“…Other papers have dealt with a in non-uniform soils but did not result in functional relationships between thermal properties and h, probably due to a paucity of depth-dependent soil h data [4,5]. Soil water content often changes substantially with depth, time, and horizontal distance.…”

Section: Introductionmentioning

confidence: 99%

Soil profile method for soil thermal diffusivity, conductivity and heat flux: Comparison to soil heat flux plates

Evett

Agam

Kustas

et al. 2012

Advances in Water Resources

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“…For measured data, the values for different harmonics may differ, although only the first few are usable. Nassar and Horton (1990) suggested using a weighted average to combine these values to provide a (hopefully) better estimate than using just the first.…”

Section: Resultsmentioning

confidence: 99%

“…For measured data, the values for diferent harmonics may difer, although only the irst few are usable. Nassar and Horton (1990) suggested using a weighted average to combine these values to provide a (hopefully) better estimate than using just the irst. Figure 1 shows generated temperatures at the surface and at depths of 0.3 and 0.6 m for the irst and ith days, by which time the periodic steady state had been attained.…”

Section: Spaial Approximaionsmentioning

confidence: 99%

Estimation of Nonuniform Soil Thermal Properties by Harmonic Analysis

Ross

2013

Vadose Zone Journal

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Existing methods of estimating spatially varying soil thermal conductivity and diffusivity using harmonic analysis of soil temperatures are applicable only at periodic steady state. This study adopted a more general Fourier analysis which is applicable when transients are present. Two new methods of estimation were compared with existing methods using synthetic data generated by solution of the one‐dimensional heat conduction equation in a soil whose water content varied with depth. All methods gave accurate results for the logarithmic derivative of conductivity and the diffusivity at steady state, but only the new methods were accurate when initial temperatures led to transients. Sensitivity to depth spacings and to noise were also investigated. Spatially interpolating the amplitude and phase of the temperature data with filtering for estimating derivatives allowed good results to be obtained in the presence of noise, especially for the diffusivity. Although the methods work best for temperatures at several depths and spacings of 0.05 m or less, errors in diffusivity were less than 8% with only three depths at 0.1 m spacing.

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Determination of Soil Apparent Thermal Diffusivity From Multiharmonic Temperature Analysis for Nonuniform Soils

Cited by 17 publications

References 0 publications

Depth and seasonal variations in the thermal properties of Antarctic Dry Valley permafrost from temperature time series analysis

Depth and seasonal variations in the thermal properties of Antarctic Dry Valley permafrost from temperature time series analysis

Soil profile method for soil thermal diffusivity, conductivity and heat flux: Comparison to soil heat flux plates

Estimation of Nonuniform Soil Thermal Properties by Harmonic Analysis

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