Geostrophic Wind and Gradient Wind
Praveen Kumar SinghM. Sc. Environmental ScienceCentral University of Rajasthan
The Geostrophic Equation
Expresses the magnitude of the wind speed as a function of the geopotential height gradient on a constant pressure surface.
Where, go = gravitational acceleration, f = Coriolis parameter = 2sin(). = angular velocity vector of the planet (7.292 x 10-5 s-1 )f ranges from -1.4 x 10-4 s-1 at South Pole to +1.4 x 10-4 s-1 at the North Pole.f about 1 x 10-4 s-1 for mid-latitudes.
Elements of Geostrophic Balance A. Pressure Gradient Force
Image coriolis forceContinued..
Continued..The Geostrophic Balance
Geostrophic winds exist in locations where there are no frictional forces and the isobars are straight. Isobars are almost always curved and are very rarely evenly spaced. This changes the geostrophic winds so that they are no longer geostrophic but are instead in gradient wind balance. Gradient Wind