Above is one of the aerological levels of the world of Aeroclysm. It is a region defined by rarefied air, extremely buoyant objects, and a large number of relics from Before (see Aeroclysm History).
Aerology
Above is not defined by a firm border in the way that Below is. Rather, it is an area where the buoyancy and flight capabilities of most vessels simply can't lift them any higher.
At some of the highest levels of Above, the environment becomes deadly. The cold freezes the blood in your veins, and the air is so thin that you can't breathe.
Unseen Library