Pressure Gradient?

Question

The term pressure gradient refers to

A. Change in pressure at a weather station over 3 hours time
B. Change in wind speed at the station
C. Change in pressure along a horizontal surface
D. Change in pressure through the tropopause

Answer 1

The answer to this question is c. the change in pressure along a horizontal surface, although it can be a change in pressure with height as well. In fact the change in pressure with height dp/dz = -(rho)g, is the hydrostatic equation important in numerical weather prediction models where rho is the density and g is the gravitational acceleration, p is pressure and z is the vertical coordinate.

Answer 2

In atmospheric sciences (meteorology, climatology and related fields), the pressure gradient (typically of air, more generally of any fluid) is a physical quantity that describes in which direction and at what rate the pressure changes the most rapidly around a particular location. The pressure gradient is a dimensional quantity expressed in units of pressure per unit length. The SI unit is pascal per metre (Pa/m).