What are AERO lights?

Aero lights:

The intensity of aero lights is often greater than that of most marine navigational lights, and they are often placed at high elevations. They may be the first lights, or looms of lights, sighted when approaching land. Those likely to be visible from seaward are charted and included in Admiralty List of Lights.
Aero lights are not maintained in the same manner as marine navigational lights and may be extinguished or altered without warning to the mariner.