Pressure and Wind

Global circulation cells, warm air rises, cold air sinks: equatorial low (ITCZ, doldrums), sub-tropical high (horse latitudes),  sub-polar low (polar front), polar high;

pressure: isobars, pressure gradient; pressure gradient force, coriolis force, surface friction;

Global winds:  High to low pressure (perpendicular to isobars), coriolis effect: polar easterlies, westerlies, trade winds, doldrums

regional patterns:  cyclone, low pressure, ccw, inward, convergent; anticyclone, high pressure, outward, divergent

local winds:  monsoon, sea breeze/land breeze, mountain breeze/valley breeze

El Nino


Describe how temperature differences drive the global atmospheric circulation patterns of the Earth.  How does this influence the distribution of high and low pressure zones on the Earth.  Where are the high and low pressure zones and what are their names?  Why do they occur in these locations?

Explain how pressure gradient, coriolis force, and surface friction determine the direction and speed of wind. 

Describe the major wind system on the Earth.  How are they influenced by the pressure zones?  What directions do they blow?  Why?  What are their names?  Be able to draw these wind systems on a map.

How are global pressure and wind zones affected by seasons?  What are Rossby waves?  How do they influence our weather?  Why is the weather in Marysville more seasonally affected than southern California?

Describe the  wind patterns around a cyclone and an anti-cyclone.  How and why are they different?  Why are the wind directions different near the ground than they are in the upper atmosphere?

Explain how temperature differences can cause local winds.  Describe two examples.

Describe El Nino and how it forms.  How does it affect weather on the west coast of N. America and on the east coast of Asia?



Back to Earth Science Home Page