Admittance (geophysics)

In geophysics, admittance describes the small effects of atmospheric pressure on earth gravity. Studies have also been carried out regarding the gravity of Venus.
Admittance in geophysics takes atmospheric pressure as the input and measures small changes in the gravitational field as the output. Geophysics admittance is commonly measured in μGal/mbar. These units convert according to 1 Gal = 0.01 m/s2 and 1 bar = 100 kPa, so in SI units the measurement would be in units of;
formula_1   or   formula_2   or   formula_3   or, in primary units   formula_4
However, the relationship is not a straightforward one of proportionality. Rather, an "admittance function" is described which is time and frequency dependent in a complex way.