ESS228
Prof. Jin-Yi Yu
Geostrophic
Adjustments
•The atmosphere is nearly always close to geostrophic and
hydrostatic balance.
•If this balance is disturbed through such processes as
heating or cooling, the
atmosphere adjusts itself to get back into balance. This process is called geostrophic adjustment.
•A key feature in the geostrophic adjustment process is
that pressure and velocity
fields have to adjust to each other in order to reach a geostrophic balance. When the balance is achieved, the flow at any
level is along the isobars.
•We can study the geostrophic adjustment by studying the
adjustment in a barotropic
fluid using the shallow-water equations.
•The results can be extended to a baroclinic fluid by
using the concept of equivalent
depth.