Parameter Tree:
EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC TEMPERATURE > SURFACE TEMPERATURE > POTENTIAL TEMPERATURE

Definition:
The temperature that an unsaturated parcel of dry air would have if brought adiabatically and reversibly from its initial state to a standard pressure, p0, typically 100 kPa.

Reference:
Glossary of Meteorology, American Meteorological Society, 2013, http://glossary.ametsoc.org/wiki/Potential_temperature