EARTHSC 2C03 Lecture Notes - Lecture 6: Heat Flux, Thermal Diffusivity, Thermal Conductivity
15 Feb 2017
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Document Summary
A shallow layer of sub-strata below the active layer is influenced by energy and mass exchange processes occurring at the surface. Interaction between the active layer and the sub-surface layer is mostly through molecular diffusion. Assume that sensible heat flux going into a volume is more than sensible heat leaving that volume then. Mean temperature change of a volume will be proportional to the heat absorbed. It will also depend on thermal properties of the volume. Ts s t where cs is heat capacity (j m-3 k-1) and ts is mean temperature change over time interval t. Qs/ z is the change in heat flux density in soil layer z (or change in heat flux in the volume). Typical values of heat capacity are (see table 2. 1, oke, 1987): Cs = 1. 42 x 106 j m-3 k-1. 6 which is equivalent to 0. 457 ok per hour.
