bmorepunk":131qo78t said:I dare you to do some calculations, polaris. I refused to get my thermo book out.
I do as well. The actual calculations if you want to include boundary conditions and equi-thermal zones is beastly. However, I think we can safely so some "Fermi number" approximations. I think we can assume that if the field has a high percentage of water in it, when we can assign a specific heat for the field of almost 1 in cgs units. If we assume an artificial field, that's lower (prob near the specific heat of rubber) which using Fermi numbers is probably about .75 or so.
[For those that aren't in the hard sciences, Fermi numbers means 'order of magnitude' calculations. They aren't meant to be used to make specific predictions but do serve as a first step to 'sanity check' what results are reasonable.]
Air has a specific heat (in cgs) of about 0.001 approximately. In short, the heat needed to heat 1 gram of water by 1 degree Kelvin would be enough to raise 1000 grams of air by one Kelvin. Now factor in that air has a very low density (when compared with any solid or liquid).
The question now becomes one of boundary conditions: What temperature is the heated field set at. If the field is set at say 5C (or 278 Kelvin) and the starting ambient air temperature is 0F or about -15 C or about 260 Kelvin, then a one degree loss on the surface of the field [or equivalently the energy needed to prevent that loss] could easily heat the air near the field (up to the first meter or so) to near 0C [say -5 C or so which would be in the low twenties].
I admit this is all back-of-envelope approximations, but the idea that a heated field would blunt the cold in calm conditions is not at all outlandish. You see exactly the same effect around a fishing hole in a large lake under very cold conditions.