Again, not my field of expertise, but worth asking: There's going to be much much more air between two mountains 80km apart than between the surface and 80km al

Again, not my field of expertise, but worth asking: There's going to be much much more air between two mountains 80km apart than between the surface and 80km altitude. I believe the quantity of air in a column above you at sea level is about equal to 9km of sea-level air. How would that change the problem?