In atmospheric science, geostrophic flow is the theoretical wind that would result from an exact balance between the Coriolis force and the pressure gradient force. Wikipedia

Theoretical wind that would result from an exact balance between the Coriolis force and the pressure gradient force Wikidata

That horizontal wind velocity for which the Coriolis force exactly balances the horizontal pressure gradient force. The geostrophic wind is thus directed along the contour lines on a constant-pressure surface (or along the isobars in a geopotential surface) with low elevations (or low pressure) to the left in the northern hemisphere and to the right in the southern hemisphere. Wiktionary