[Europan Ocean (OP)]

I recall that shells in WW1 would when free from the crust the land not turn with the Earth, and land 15 degrees off from a straight line. What effect does the air being loose from the ground have on the air currents?

[Bored chemist]

If the air wasn't fairly well attached to the ground there would be a 1000 mile per hour wind at the equator.

[evan_au]

What effect does the air being loose from the ground have on the air currents?

It produces weather.

Pluto has a fairly elongated orbit, and so much of its atmosphere rejoins the ground on the farther parts of its orbit.
New Horizons passed it when it still had a fair amount of atmosphere.