em
em copied to clipboard
Resistivity/conductivity of air
In the following table https://em.geosci.xyz/content/maxwell1_fundamentals/harmonic_planewaves_homogeneous/skindepth.html#skin-depth-for-various-materials the conductivity of air is given as 0 S/m, which results in an infinite skin depth, suggesting that an EM signal travels the whole globe back and forth.
In 3D modelling we often use a conductivity of something between 1e-14 S/m to 1e-8 S/m (on Wikipedia it states the range as 1e-15 to 1e-9 S/m; https://en.wikipedia.org/wiki/Electrical_resistivity_and_conductivity), which yields finite skind depths for air. This is (a) more realistic, and (b) also what we often use in actual 3D modelling?
Does anything speak against updating this table accordingly?