To introduce students to the science of hurricanes in an effort to highlight how forces change the speed and direction of motion.
This lesson is the first of a two-part series on the science of hurricanes and the kinds of technology being used to identify and track them.
In Hurricanes 1: The Science of Hurricanes, students examine different scientific aspects of hurricanes, all in an effort to begin to understand the nature of motion—particularly how changes in speed or direction of motion are caused by forces.
In Hurricanes 2: Tracking Hurricanes, students’ study of hurricanes is broadened by exploring how technology and science are used today to identify, measure, and track powerful tropical storms to better warn and secure people from their often-devastating impact.
In teaching about hurricanes at this elementary level, it is helpful to introduce broad concepts about motion and forces, such as the fact that everything in the universe moves and that nothing in the universe is at rest. Students may also be able to grasp that changes in motion—speeding up, slowing down, changing direction—are due to the effects of forces. (Science for All Americans, pp. 52–53.) While teaching, keep in mind that students should have a lot of experiences to shape their intuition about motion and forces long before encountering laws. In the context of hurricanes, it is important that students walk away from these lessons knowing simply that air pressure, water, and wind currents are all phenomena that influence the formation, motion, and direction of hurricanes.
It is important to note the many misconceptions that younger students have about forces and motion. For example, in the area of forces, research has shown that students hold various meanings for the term force. Typically, students think force is something that makes things happen or creates change. Their descriptions of force often include related words such as energy, momentum, pressure, power, and strength. Younger students associate the word force with living things. In addition, students tend to think of force as a property of an object (an object has force, or force is within an object) rather than as a relation between objects. Also, they tend to distinguish between active objects and objects that support or block or otherwise act passively. Students tend to call the active actions force but do not consider passive actions as forces. (Benchmarks for Science Literacy, p. 339.)
Research on students’ ideas about motion is also helpful. For example, students believe constant speed needs some cause to sustain it. Moreover, they believe that the amount of motion is proportional to the amount of force; that if a body is not moving, there is no force acting on it; and that if a body is moving there is a force acting on it in the direction of the motion. Students also believe that objects resist acceleration from the state of rest because of friction—that is, they confound inertia with friction. (Benchmarks for Science Literacy, p. 339.)
At this level, it is also recommended that students begin to increase their repertoire of tools and techniques and improve their skills in measurement, calculation, and communication. To accomplish this goal, students may use instruments like microscopes, telescopes, cameras, sound recorders and, in this lesson series, online mapping and tracking instruments, in order to reinforce the importance of the dependence of science on technology. Students at this level should also be encouraged to begin to write about technology, particularly how technology helps people in various ways. (Benchmarks for Science Literacy, p. 45.)
Note: This lesson series is more appropriate for students at the upper end of the 3-5 grade band, partly because of the rather complex nature of the websites being used.
Before students learn about hurricanes on the Internet, tap their present knowledge by asking them to talk about personal experiences with hurricanes and what they think and or know about them. Encourage full classroom participation. Accept all responses and do not provide explanations. The purpose of this activity is simply to draw out what students know about hurricanes (and motion).
- What are hurricanes?
- What do they do?
- What are they made of?
- Where do they come from?
- What do you think causes the movement of hurricanes?
- What usually happens when hurricanes develop?
- Have you ever seen one?
(Accept all answers, but ask students to support their views with explanations.)
Note: These kinds of basic, fundamental questions will be revisited in the Assessment in an attempt to determine how student understanding moved forward as a result of this lesson.
At this stage of the lesson, you should introduce students to the scientific aspects of hurricanes that they can understand at this level. With this in mind, it is important to remember the structure and benchmark purpose of this lesson: to use hurricanes as a context in which to talk about forces.
Even though students may not be able to fully grasp detailed concepts about forces at this level, it is recommended that as they explore the hurricane-related sites in this lesson and series, simple references are made to benchmark ideas where appropriate.
First, direct students to The Science of Hurricanes student esheet, which will guide them through the online portion of the lesson.
As shown in Step 1 of the esheet, students should view several videos of Hurricane Andrew that will show them three different perspectives of the devastating hurricane that rattled the southern United States in 1992.
Before watching each clip, be sure to read aloud these descriptions of each video. You could also have students draw and identify the shapes they see in the videos as they go:
Video 1: This is a black and white video of Hurricane Andrew. It shows the path of Hurricane Andrew from Sunday, August 23 through Thursday, August 27, 1992.
Video 2: This is a color video of Hurricane Andrew as it passes over Florida.
Video 3: This is a video of Andrew with colored areas to show rain. Yellow shows greater rainfall than green or blue.
Discuss students’ answers to these questions:
- In the first movie, what is the direction of the hurricane’s motion? (Counterclockwise.)
- What land areas does Hurricane Andrew move over? (The West Indies, Caribbean, Florida, Louisiana, and others.)
- What do you think causes hurricanes (or other things in life) to speed up or down? (As noted in the benchmark, "changes in speed or direction of motion are caused by forces. The greater the force is, the greater the change in motion will be. The more massive an object, the less effect a given force will have.")
- Do you think hurricanes speed up or slow down while over land? (Hurricanes lose power and slow down as they come over land.)
- What do you think it was like in Florida and Louisiana on the day Hurricane Andrew struck these areas? (Answers will vary. Encourage a wide array of responses.)
As outlined in Step 2 of the esheet, have students go to Anatomy of a Hurricane, which will introduce them to the elements of a hurricane.
Discuss student responses to the following:
- Look at arrow #1. What is that? What is going on there? (The arrow shows the hot air pressure rising upward in a spiraling fashion out of the eye and into the atmosphere.)
- Look at arrow #2. What is that? What is going on there? (Those are storm clouds spiraling in the upper atmosphere.)
- Look at arrow #3. What is that? What is going on there? (That is the eye of the hurricane, where cool air creates calm weather within the storm.)
- Look at arrow #4. What is that? What is going on there? (This eye of the hurricane is made up of fierce wind forces that give the hurricane much of its power.)
- Look at arrow #5. What is that? What is going on there? (This arrow shows spiraling wind forces that flow toward the center of the hurricane and whirl upward. They swirl counterclockwise and gain tremendous speed as they approach the eye.)
To avoid overwhelming students, you needn't insist that they grasp the five listed elements. Perhaps it would be most effective to discuss what is happening in the hurricane visual as a weatherman might, by focusing on what is happening with the arrows and air and wind forces. This approach might also allow for the opportunity to make references to the central benchmark concepts—particularly that air pressure, water, and wind currents are all forces that play a role in forming hurricanes and controlling their speed, direction, and motion in general.
As highlighted in Step 3 of the esheet, students should go to the Hurricanes! site, where they should scroll down the page and read about Andrew's History. You should emphasize points that support the benchmark and Andrew's progression from a rainy, low-pressure wave into an intensified, swirling tropical storm before officially becoming a hurricane once it reached 74 m.p.h. over the ocean.
After reading details of Andrew’'s tremendous speed and tragic impact in the lower United States, direct students to the pictures from radar and storm image links at the bottom of this section. You may choose to read the introduction section on the effects of Andrew before having them look at the six radar and eight damage images on the left-hand side of this page. Elicit their reactions to the strong and realistic images of the hurricane's damage.
Discuss the following questions:
- How large was Hurricane Andrew compared to the state of Florida?
- What do you think the weather was like there on the day Hurricane Andrew hit?
- How would you describe the damage the hurricane created in the area?
- What do you think happened to the people living in those areas?
(Accept all answers, but ask students to support their views.)
Following the instructions for Step 4 of the esheet, have students scroll further down the Hurricanes! page to read over More About Hurricanes, Typhoons and Cyclones, which can serve as a brief review and broadening of what they have already learned in this lesson.
Review with students what they have learned about hurricanes, particularly the benchmark ideas explaining how changes in the motion of hurricanes and other objects and phenomena are caused by forces. A good way to begin this process is to have students readdress some of the basic questions they considered in the Motivation section:
- What are hurricanes? (Answers will vary. In very basic terms, hurricanes are tropical storms with winds that grow to reach over 74 m.p.h.)
- Where do they come from? What are they made of? (Answers will vary. In general, hurricanes and other types of severe tropical storms usually form over warm, tropical oceans during the summer. They start out as small regions of stormy, disturbed weather and become hurricanes when winds, warm waters, and humidity reach high levels.)
- What do you think causes the motion of hurricanes? (Air pressure, water, and wind currents cause the movement of hurricanes, but as noted in the benchmark, "changes in speed or direction of motion are caused by forces. The greater the force is, the greater the change in motion will be. The more massive an object, the less effect a given force will have.")
For more benchmark-focused review, these next questions can be considered:
- What causes hurricanes, storms, or things in general to change directions when moving? (Forces.)
- What happens to hurricanes when wind currents become stronger? Why? (They increase in speed and power because wind currents are among the forces that influence the movement and direction of hurricanes.)
- Why do hurricanes slow down and lose power when moving over land? (They slow down and lose power when traveling over land because they are no longer connected to the severe humidity and warm water sources that gave them their original power.)
Overall, students should now be able to identify and conceptualize the basic elements of a hurricane, and the fact that natural forces like air pressure, water, and wind currents cause hurricanes (and other natural phenomena in the universe) to change the speed and direction of their motion.
They should also be able to understand that a hurricane: (a) moves in a counterclockwise, rotational motion; (b) has a center or "eye" which is a low-pressure area that is made up of cool, calm weather; (c) slows down while traversing land areas; (d) can develop from a small storm and gradually turn into a hurricane (at 74 m.p.h.), if enough climatic elements and forces are present; and (e) is often very dangerous, damaging, and life-threatening to the populated areas it encounters.
Optional Activity: Depending on your time availability, the following assessment activity can be done in class and/or as homework:
Have students take out a piece of paper and write at the top of it, "Today, I learned these things about hurricanes and motion…" Then have them list as many facts as they can remember about hurricanes, including insights about the formation, movement, and impact hurricanes have over land.
Depending on your preferences, you can promote this activity as a contest, where the person who comes up with the longest list of facts wins a simple, random prize (or the humorous, one-day title of "Mr. Hurricane" or "Ms. Hurricane").
Follow this lesson with the second lesson in the Science NetLinks series on Hurricanes: Hurricanes 2: Tracking Hurricanes.
For current information, research, and Web resources on Hurricanes, see the Science Update entitled Hurricanes.
The Hurricane! lesson plan, from DiscoverySchool.com, can serve as an exciting and challenging extension for your older or more advanced students.