https://en.wikipedia.org/wiki/Colatitude
In spherical coordinates, colatitude is the complementary angle of the latitude, i.e. the difference between 90° and the latitude,[1] where southern latitudes are denoted with a minus sign.
Examples
Latitude and colatitude sum up to 90°.
place latitude colatitude
north pole 90° 0°
equator 0° 90°
south pole -90° 180°