ESS124
Prof. Jin-Yi Yu
Forces that Affect
Atmospheric Motion
•Newton’s second law of motion states that the rate of change
of momentum (i.e., the acceleration) of an object, as measured relative to coordinates
fixed in space, equals the sum of all the forces acting.
•For atmospheric motions of meteorological interest, the
forces that are of primary concern are the pressure gradient force, the gravitational force, and
friction. These are the fundamental forces.
•For a coordinate system rotating with the earth, Newton’s
second law may still be applied provided that certain apparent forces,
the centrifugal force and the Coriolis force, are included among the forces acting.
Fundamental
force -
Gravitational force
Pressure gradient force
Frictional force
Coriolis force
Apparent force -
Centrifugal force