A question about refraction

I was doing a Analysis of ones of Jtolans videos of the Rockies from 270 miles away. The refracted amount seems to fit the observation to the T though.
From an altitude, you are looking down through more air, but the gradient perpendicular to the light path is similarly reduced. So it might cancel out to be the same as the horizontal distance. I suspect on average it will be similar to "standard" refraction, and much more consistent as upper air temps vary less.