1. The temperature that mantle material would have were it raised to a specified depth where it was subjected to lower pressure. Decompression lowers the temperature and the potential temperature determines the depth at which melting will occur.

2. The temperature a volume of water would have if it were raised to a specified level, usually the ocean surface.

3. The temperature a parcel of air would have if it were brought to the surface, warming at the dry adiabatic lapse rate.