1. Title: Atmosphere in Motion; Wind Bands Page #: 75 Date: 2/25/2013
Table of Contents
Title: Atmosphere in Motion; Wind Bands
Page #: 75
Date: 2/25/2013

2. Objective
Students will be able to explain the origin of Earth’s prevailing wind patterns.

3. Essential Question
Where do Earth’s prevailing wind patterns come from?

4. Word of the Day
Wind: The process by which heat is distributed from Earth’s equator to the poles.

5. Why does
Jupiter have stripes?
What do the arrows
Indicate?

6. Wind Bands
Winds are the product of warm air rising at the equator and moving towards the poles.
Coriolis Effect (a result of Earth’s rotation) causes air to be deflected to
The right in the Northern Hemisphere
The left in the Southern Hemisphere

7. Wind Bands
Wind Bands (“Prevailing Winds”): Earth’s major wind patterns.
Direction of wind is determined by 3 factors:
Convection Currents
Earth’s rotation from West to East
Air pressure (High = Cold; Low = Warm)

9. Wind Bands
3 Factors of wind direction create 3 convection cells in each hemisphere.
These convection cells are mirror images of each other.

11. Wind Bands Convection cells are defined by latitude:
Northern Hemisphere
0º - 30ºN “Northeast Trade Winds,” wind blows from Northeast
30º - 60ºN “Westerlies,” wind blows from West
60º - 90ºN “Polar easterlies” wind blows from East

12. Wind Bands Convection cells are defined by latitude:
Southern Hemisphere
0º - 30ºS “Southeast Trade Winds,” wind blows from Southeast
30º - 60ºS “Westerlies,” wind blows from West
60º - 90ºS “Polar easterlies” wind blows from East

13. Wind Bands Spots of low wind:
Equator - “Doldrums” air is rising vertically.
30ºN and 30ºS - “Horse Latitudes” air is descending vertically.