The imaginary layer of soil is used to model a non-isothermal earth surface.

Symbol
$d_{\mathrm{im}}$
Unit
m
Formulae
$\frac{1}{h_{\mathrm{tr}} \rho_{\mathrm{4}}}$
Related
$h_{\mathrm{tr}}$
$\rho_{\mathrm{4}}$
Used in
$L_{\mathrm{cm}}$
$L_{\mathrm{cni}}$