Learner Objectives

By completing this lesson, learners will:

• describe how hurricances change appearance over time.
• use the magnification procedure on NIH Image (Mac) or Scion Image (PC)to view individual pixel elements.
• measure the diameter of the Hurricane Andrew using image processing software.

Exploration

• Image Imposed on Map
• View from Geostationary Orbit

2. Save each of the images listed below (label them by date, e.g., Aug24) and convert them to TIFF using GifConverter (Mac) or Paint Shop Pro (PC) (instructions).  Start NIH Image. When the program has stopped loading, pull down the File menu and select Open. When the dialog box appears, double-click on the image Aug24. Use the hand tool from the Tools Window to slide the image up until the hurricane is visible.
Sequence

Eventually, the small squares that comprise the image will become visible. Each of these picture elements, or pixels, represents some portion of the Earth's surface. Because the surface of the Earth is curved, not all pixels represent the same area on the ground. As a result, precise measurements based on such images involve complex mathematical and scientific factors beyond the scope of this lesson. On the other hand, reasonable estimates can be made using NIH Image and a few WWW information resources. (Using NIH Image involves procedures found in Resources "step by step").

Use this link to learn how to calibrate NIH Image to your pictures.

Making Your Own Weather Movie

Hurricanes are powerful, dynamic storms. As they move from one body of water to another or from water onto land, they change in important ways. Animation provides a way to study those changes.

Animating a sequence of images using NIH Image involves procedures found in Resources "step by step"

• Collect a set of images, all of which have the same dimensions (easy) and the same color pallette (not so easy). The following images all have these attributes. Go to Resources "step by step" for directions to animate the following images.
• stack24.TIFF
• stack25.TIFF
• stack26.TIFF
• stack27.TIFF

2. Between which two days did the storm travel the greatest distance?

3. Assume the images are made 24 hours apart, compute the speed of the hurricane in miles per hour. Use distance determinations from the calibrate step above to compute speed (s=d/t).

Extensions

• Analyze detailed images of HurricaneAndrew using NIH Image movies and write narration.
• Plot the locations of a current tropical storm using current data and a downloaded map.
• At what point was Andrew most destructive? (from newspaper or magazine reports)
• What was Andrew's strength when it struck the Carribean Islands, Florida, and Louisiana?  Does that strength correspond with the damage that was done?