Accession Number:

ADA446854

Title:

Variations in FASST Predictions of Soil Surface Temperatures

Descriptive Note:

Technical rept.

Corporate Author:

ENGINEERING RESEARCH AND DEVELOPMENT CENTER HANOVER NH COLD REGIONS RESEARCH AND ENGINEERING LAB

Personal Author(s):

Report Date:

2006-04-01

Pagination or Media Count:

78.0

Abstract:

This report presents the results of a systematic investigation of the variation in soil surface temperatures predicted by the numerical model FASST Fast All Seasons Soil Strength, using different values of soil physical, thermal, and optical parameters. Soil hydraulic properties were not varied. Single-factor experiments have shown that the major soil parameters for FASST predictions are, in descending order, initial volumetric soil moisture content, bulk density of the dry soil material, albedo sunny days, and porosity. The thermal conductivity of the dry soil material has a minor effect on predicted soil temperature. Quartz content, specific heat of the dry soil material, and emissivity each has a negligible effect on predicted soil temperature. Experiments varying several soil parameters simultaneously produced temperature differences relative to a standard soil for some combinations of factors that are larger than were obtained by varying a single major soil factor. This highlights the difficulty of associating a measure of confidence with a given FASST simulation, i.e., how closely predicted temperatures will match actual soil temperatures for a given soil type and weatAbstract This report presents the results of a systematic investigation of the variation in soil surface temperatures predicted by the numerical model FASST Fast All Seasons Soil Strength, using different values of soil physical, thermal, and optical parameters. Soil hydraulic properties were not varied. Single-factor experiments have shown that the major soil parameters for FASST predictions are, in descending order, initial volumetric soil moisture content, bulk density of the dry soil material, albedo sunny days, and porosity. The thermal conductivity of the dry soil material has a minor effect on predicted soil temperature. Quartz content, specific heat of the dry soil material, and emissivity each has a negligible effect on predicted soil temperature.

Subject Categories:

  • Physical Chemistry
  • Soil Mechanics
  • Thermodynamics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE