In geophysics, a free air anomaly is the difference between observed gravity and theoretical gravity that has been computed for latitude and corrected for elevation of the station above or below the geoid, by application of the normal rate of change of gravity for change of elevation, as in free air. According to the Encyclopedic Dictionary of Applied Geophysics (Robert E. Sheriff, 2002, Tulsa USA), the free to air correction is 0.3086 mGal/m (3.086 µm/(s²·m)).
- see also: gravity anomaly, physical geodesy
