“Insisting dogmatically on a theoretical construct like the dry adiabatic lapse rate – and on one particularly dubious assumption especially – ”
*What* dubious assumption am I making? You aren’t saying. My main assumption that contradicts your own is the standard quite natural assumption that the expanding parcel of air performs work dW = PdV on the surrounding and this is taken from the internal energy of the parcel. This assumption is formalized explicitly in the mathematical derivation of the lapse rate that you quoted approvingly.
Your own two mutually inconsistent assumptions, either (1) Joule expansion, with dW = 0 — which implies, rather ridiculously, no lapse rate at all, or (2) the Joule-Thompson constant-enthalpy expansion process, that has no physical justification either since the expansion of the rising parcel of air isn’t close to be enthalpy preserving.
You also extracted from Wikipedia the single paragraph that seems out of place (and may have been put there by Doug C. for all we know) and contradicts the assumption about gravitational potential energy that you yourself had endorsed in the mathematical derivation of the lapse rate. There is *no* internal energy change in the parcel of air corresponding to the change in gravitational potential energy, pace Doug C and yourself.
You seem to be reaching in the dark in order to justify some of the indefensible claims that you made. You also never explained *what* kind of “energy” you are referring to that you alleged remains constant while the parcel of air expands and its internal energy, and therefore also its temperature, both drop. Again, internal energy would be constant *if and only if* the adiabatic expansion process would be a process of “Joule expansion”, but in that case dW = 0 and there would be no temperature change within the rising (or descending) parcels and hence no lapse rate at all.