World Wide Winds

Author: Kirstin A. Bittel

Time: 1 class period
Preparation Time: 5-10 minutes
Materials: Access to Proxima
Aver Key or Computer Lab
World Wide Winds Handout

In this lesson, students will observe a variety of computer models showing wind, cloud, and pollution movements over the globe. Students will use this information to as an introduction to determining the three-cell model of weather and give names to the Hadley, Ferrell, and Polar Cells. They will also uncover the Trade winds, Westerlies, and Polar winds.

Purpose – Exploration of world wind patterns.

Students will be able to:
1. Recognize that global winds move in specific directions in specific latitudes and describe that in a written form.
2. Relate the motion of the wind belts to historical navigation.

National Science Education Standard:
CONTENT STANDARD D: Earth and Space Science
• Earth systems have internal and external sources of energy, both of which create heat. The sun is the major external source of energy. Two primary sources of internal energy are the decay of radioactive isotopes and the gravitational energy from the earth’s original formation.

• Heating of earth’s surface and atmosphere by the sun drives convection within the atmosphere and oceans, producing winds and ocean currents.

• Global climate is determined by energy transfer from the sun at and near the earth’s surface. This energy transfer is influenced by dynamic processes such as cloud cover and the earth’s rotation, and static conditions such as the position of mountain ranges and oceans.

• Movement of matter between reservoirs is driven by the earth’s internal and external sources of energy. These movements are often accompanied by a change in the physical and chemical properties of the matter. Carbon, for example, occurs in carbonate rocks such as limestone, in the atmosphere as carbon dioxide gas, in water as dissolved carbon dioxide, and in all organisms as complex molecules that control the chemistry of life.

Teacher Background
The sun is the driving force behind the global wind patterns. As the sun heats the equator, the air is heated and rises, moving North and South, away from the equator. Cold air rushes in to take its’ place. This creates a convection cell that extends from the equator to about 30 degrees North and South Latitude. This cell is called the Hadley cell after it discoverer George Hadley in 1735. The next cell is the Ferrell cell, which was identified by the American William Ferrell in the 1800s. This cell connects the sinking air at the 30th parallels to the Westerlies. It was Ferrell who noted that the currents in the Westerlies tend to give rise to cyclonic action as a result of winds moving around a spinning Earth. The Ferrell Cells sink at the 30th parallels and rise again at the 60th parallels where the Polar Cells begin.

More detailed information available from Climate Change -

More great information is available at USA Today Weather Basics - (http://www.usatoday.com/weather/resources/basics/wworks0.htm)

Related and Resource Web sites
Global Composite Animation
(Shows Global Air Currents – good views of Trades and Westerlies)

Global Water Vapor Animation
(Shows Motion of Vapor in the Atmosphere - good views of Trades and Westerlies)

Earth Probe TOMS Aerosol Index (Shows Trades and southern Westerlies nicely, you need to cut and paste this address into the web to get it to show the animation.)

Meteosat Infrared Satellite Data from NASA
Global Composite Satellite Data from NASA
Global Composite Water Vapor Satellite Data
North America Infrared Satellite Data
http://wwwghcc.msfc.nasa.gov/GOES/ (menu screen here provide access to above maps - good views of Trades and Westerlies – set the image loop as high as possible so the students get the most time possible to observe wind motion)

Animated Global IR

Wind Patterns

Image courtesy of Dr. Grossman's GEOL101 Home Page - "Deserts"



















Image from


1. As students enter the room have the following question written on the board: What do you know about the way the wind moves?

2. Allow students a few minutes to record their thoughts and then share their ideas with their classmates.

3. Distribute World Wide Wind Data Sheet to students. Tell students their job is to observe the cloud movement from a variety of satellite images to determine how air flows around the globe.

4. Pull up the first web site and show the animation. (I suggest that you slow the animation speed down so students have time to observe. You may also want to run the animation several times as there are only around 20 frames. You can also modify this image to make the air easier to see. IR or EC are nice modifications.) As students are recording their observations remind them to pay attention to latitudes and longitudes. They should use continents as a guide. Do the winds move straight or diagonally? Do they flow continually or swirl?

5. Repeat with the remaining sites. The image of North America gives students a nice close-up of what happens here that the global views do not show.

6. Tell students they have been able to step outside the Earth to see these wind patterns. Have the students describe the patterns using the observations they took. You may want them to work together on this.

7. Explain to the students that it took sailors, navigators, and amateur meteorologists years to determine the wind patterns. What might they name each of these patterns? The belts of wind they saw are called the Trade winds, Westerlies, and Polar Easterlies. The Westerlies were named for their western origin and the Polar Easterlies for their eastern origin.

8. Using the described patterns ask students to describe how this might affect a sail boat trying to travel from one part of the globe to another.

9. Using an overhead blank map of the world have students vote on where a ship may end up.Then share with the students that the trade winds were named for the trade ships that used these winds to navigate the globe. Does this help them figure out how ships moved across the globe?

10. Share with the students that their job in the upcoming days is to determine what makes the wind move in this fashion.

Write a 2-3 sentence conclusion in your science notebook. Conclusions should describe what you learned and be thought-provoking.

Embedded Assessment
Do students see the bands of clouds moving east and west? Do they identify all 6 bands (3 in each hemisphere?) in their observations and in their descriptions to the class? Can students assess how ships might sail from one area to another?















PULSE is a project of the Community Outreach and Education Program of the Southwest Environmental Health Sciences Center and is funded by:

NIH/NCRR award #16260-01A1
The Community Outreach and Education Program is part of the Southwest Environmental Health Sciences Center: an NIEHS Award


Supported by NIEHS grant # ES06694

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Last update: November 10, 2009
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