An Analysis of Sensible and Latent Heat Flow in a Partially Frozen Unsaturated Soil

Fuchs, Márta; Campbell, Gaylon S.; Papendick, R. I.

doi:10.2136/sssaj1978.03615995004200030001x

Cited by 161 publications

(105 citation statements)

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“…(A12)-(A17) account for the impact of freezing and thawing of soil water on soil energy and water balances, following Fuchs et al (1978). The rate of ice formation is given by…”

Section: Continuous Equations For Moisture and Energy Conservationmentioning

confidence: 99%

Multiple observation types reduce uncertainty in Australia's terrestrial carbon and water cycles

et al. 2013

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Information about the carbon cycle potentially constrains the water cycle, and vice versa. This paper explores the utility of multiple observation sets to constrain a land surface model of Australian terrestrial carbon and water cycles, and the resulting mean carbon pools and fluxes, as well as their temporal and spatial variability. Observations include streamflow from 416 gauged catchments, measurements of evapotranspiration (ET) and net ecosystem production (NEP) from 12 eddy-flux sites, litterfall data, and data on carbon pools. By projecting residuals between observations and corresponding predictions onto uncertainty in model predictions at the continental scale, we find that eddy flux measurements provide a significantly tighter constraint on continental net primary production (NPP) than the other data types. Nonetheless, simultaneous constraint by multiple data types is important for mitigating bias from any single type.

Four significant results emerging from the multiply-constrained model are that, for the 1990–2011 period: (i) on the Australian continent, a predominantly semi-arid region, over half the water loss through ET (0.64 ± 0.05) occurs through soil evaporation and bypasses plants entirely; (ii) mean Australian NPP is quantified at 2.2 ± 0.4 (1σ) Pg C yr⁻¹; (iii) annually cyclic ("grassy") vegetation and persistent ("woody") vegetation account for 0.67 ± 0.14 and 0.33 ± 0.14, respectively, of NPP across Australia; (iv) the average interannual variability of Australia's NEP (±0.18 Pg C yr⁻¹, 1σ) is larger than Australia's total anthropogenic greenhouse gas emissions in 2011 (0.149 Pg C equivalent yr^–1), and is dominated by variability in desert and savanna regions

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“…(A12)-(A17) account for the impact of freezing and thawing of soil water on soil energy and water balances, following Fuchs et al (1978). The rate of ice formation is given by…”

Section: Continuous Equations For Moisture and Energy Conservationmentioning

confidence: 99%

Multiple observation types reduce uncertainty in Australia's terrestrial carbon and water cycles

et al. 2013

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“…Soil texture and initial moisture conditions seem to be crucial in affecting the availability and mobility of water. Fuchs et al (1978) developed a theory of soil freezing applicable to unsaturated conditions with solute presence in the soil. They considered that solutes tend to depress the freezing point temperature and modified the relationship between temperature, moisture content and apparent thermal properties of the soil.…”

Section: Freezing-soil Modelsmentioning

confidence: 99%

A robust and energy-conserving model of freezing variably-saturated soil

et al. 2011

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Abstract. Phenomena involving frozen soil or rock are important in many natural systems and, as a consequence, there is a great interest in the modeling of their behavior. Few models exist that describe this process for both saturated and unsaturated soil and in conditions of freezing and thawing, as the energy equation shows strongly non-linear characteristics and is often difficult to handle with normal methods of iterative integration. Therefore in this paper we propose a method for solving the energy equation in freezing soil. The solver is linked with the solution of Richards equation, and is able to approximate water movement in unsaturated soils and near the liquid-solid phase transition. A globallyconvergent Newton method has been implemented to achieve robust convergence of this scheme. The method is tested by comparison with an analytical solution to the Stefan problem and by comparison with experimental data derived from the literature.

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“…where T and T frz are soil temperature and freezing point (K), respectively (Fuchs et al 1978); L f is the latent heat of fusion (J kg…”

Section: A Implementation Of the Supercooled Soil Watermentioning

confidence: 99%

Effects of Frozen Soil on Snowmelt Runoff and Soil Water Storage at a Continental Scale

Niu

Yang

2006

Journal of Hydrometeorology

441

397

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The presence of ice in soil dramatically alters soil hydrologic and thermal properties. Despite this important role, many recent studies show that explicitly including the hydrologic effects of soil ice in land surface models degrades the simulation of runoff in cold regions. This paper addresses this dilemma by employing the Community Land Model version 2.0 (CLM2.0) developed at the National Center for Atmospheric Research (NCAR) and a simple TOPMODEL-based runoff scheme (SIMTOP). CLM2.0/ SIMTOP explicitly computes soil ice content and its modifications to soil hydrologic and thermal properties. However, the frozen soil scheme has a tendency to produce a completely frozen soil (100% ice content) whenever the soil temperature is below 0°C. The frozen ground prevents infiltration of snowmelt or rainfall, thereby resulting in earlier-and higher-than-observed springtime runoff. This paper presents modifications to the above-mentioned frozen soil scheme that produce more accurate magnitude and seasonality of runoff and soil water storage. These modifications include 1) allowing liquid water to coexist with ice in the soil over a wide range of temperatures below 0°C by using the freezing-point depression equation, 2) computing the vertical water fluxes by introducing the concept of a fractional permeable area, which partitions the model grid into an impermeable part (no vertical water flow) and a permeable part, and 3) using the total soil moisture (liquid water and ice) to calculate the soil matric potential and hydraulic conductivity. The performance of CLM2.0/SIMTOP with these changes has been tested using observed data in cold-region river basins of various spatial scales. Compared to the CLM2.0/SIMTOP frozen soil scheme, the modified scheme produces monthly runoff that compares more favorably with that estimated by the University of New Hampshire-Global Runoff Data Center and a terrestrial water storage change that is in closer agreement with that measured by the Gravity Recovery and Climate Experiment (GRACE) satellites.

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An Analysis of Sensible and Latent Heat Flow in a Partially Frozen Unsaturated Soil

Cited by 161 publications

References 0 publications

Multiple observation types reduce uncertainty in Australia's terrestrial carbon and water cycles

Multiple observation types reduce uncertainty in Australia's terrestrial carbon and water cycles

A robust and energy-conserving model of freezing variably-saturated soil

Effects of Frozen Soil on Snowmelt Runoff and Soil Water Storage at a Continental Scale

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