Many decades ago when I was an air cadet, I think I was taught that air temperature aloft typically reduces by c. 1C for each 1000ft of altitude.
Logically, if this were true, it should mean that an aircraft flying a Great Circle route in July at a constant altitude of 38,000ft from overhead the North Pole (-50C at ground level ?) to overhead Aziziya in Libya (+50C at ground level ?) would experience an outside air temperature rising from -88C to +11C.
I'm sure this can't be right, but would love to hear the correct answer from a suitably qualified person, thanks
