An Analytical Soil Thermodynamic Model for the Diurnal Variation of Ground Surface Temperature.

Abstract

An analytical expression is given for time variations of temperature within a model soil slab that is subjected to idealized heating at the supper surface and maintained at constant temperature at the lower surface. Applied at the upper surface, the model temperature may be considered to be the ground surface temperature of the earth. An important feature of this model is that phase-shifted on-linear responses to the forcing are allowed at the upper boundary. The analytical nature of the solution enables us to easily study the relative importance of various physical processes in the model surface energy budget equation. For example, evaporational cooling is found to be an important feedback process under model summer conditions, accounting for a change of about 6K in the daily mean surface temperature; under winter conditions, the change attributable to evaporation is only about 1K. The perturbation method used in our approach to linearize the model upper boundary condition is shown to be applicable to more complicated and more realistic upper boundary conditions.

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Document Details

Document Type
Technical Report
Publication Date
Jan 05, 1987
Accession Number
ADA185388

Entities

People

  • George D. Modica
  • Samuel Y. Yee

Organizations

  • Air Force Research Laboratory

Tags

Communities of Interest

  • Energy and Power Technologies
  • Materials and Manufacturing Processes

DTIC Thesaurus Topics

  • Boundary Layer
  • Differential Equations
  • Diurnal Variations
  • Ecology
  • Energy
  • Equations
  • Heat Capacity
  • Heat Energy
  • Heat Flux
  • Heat Transfer
  • High Resolution
  • Latent Heat
  • Phase Shift
  • Radiation
  • Solar Radiation
  • Surface Energy
  • Surface Temperature

Readers

  • Calculus or Mathematical Analysis
  • Ocean-Atmosphere Mesoscale Modeling, Data Assimilation, and Flux Boundary Layers