Atmospheric Temp., Pressure And Winds *G11 Flashcards
What is wind
Moving air (that blows from high pressure areas to low pressure areas)
What is pressure gradient
Differences in atmospheric pressure between high and low pressure areas
What does a strong pressure gradient tell us *3
*steeper gradient
*strong winds
*cold air
What does a low pressure gradient tell us *3
*gentle gradient
*light winds
*warm air
What is coriolis force
the force that deflects winds due to earth’s rotation
Where does coriolis force not occur
Within 5* of the equator
The the speed of rotation at the poles and the equator *2
*0km/h @ poles
*1670km/h @ equator
Moving air retains the rotation speed of the surface, what does this mean
Air will end up ahead or behind surface it’s blowing
What is Ferrell’s law *2
As a result of coriolis force, winds are deflected to the
*left in SH
*right in NH
What is geostrophic flow
The theoretical wind that results from the exact balance between CF and PGF
Why does geostrophic balance rarely occur in the lower atmosphere
*true wind differs from geostrophic wind due to factors like friction with the earths surface
Friction definition
Contact with a (land/sea) surface that slow air movement
Explain geostrophic wind (3)
*Air moves from hpa to lpa (PGF)
*as it moves from hpa, its speed and deflection increases (CF)
*the air no longer moves from hpa to lpa, but moves along a line of equal pressure
