II. Local Winds in Global Context
Students will learn how to measure their local winds and compare those measurements with those provided by a real-time map of global winds.
How close do our local winds come to the average for our region?
Why use data from multiple participants?
Each student will contribute his or her unique finding of the relationship of local winds to the global averages. Each will share hypotheses about the impact of local terrain on wind speed.
This project will ask you to share your data in a Report Form. You might find it helpful to print this form and take notes on it as you go through the activity.
I. Measure the speed and direction of your local winds.
You can use an anemometer or a balloon, with a compass and stopwatch as needed. There are some new anemometers that can be attached to an iPhone, for example. Many smart phones, in addition, have compasses built in.
Steps using a balloon:
a. Go out onto an open, level field.
b. Release a plain air balloon.
c. Have another person ready to capture the balloon.
d. Measure the time between the release and the capture of the balloon some distance away.
e. Measure the direction. Use the compass to determine the heading that the balloon travels.
f. Measure the distance between the release and the capture of the balloon.
One way to do this is to have a student learn to pace off one-meter steps. Have that student walk the distance the balloon traveled.
g. Calculate wind speed = distance in meters divided by time in seconds to get meters per second.
If you have time, repeat measurements three times and get the average speed and direction.
Need help obtaining meters/second? Try a web tool such as www.calculateme.com/Speed/MilesperHour/ToMetersper...
2.Go to the Global Winds web site.
Relate your outdoor wind speed finding to the surface wind speed for your area as represented on the Global Winds map
(The following will be easier if you have done the first Map activity.)
Center the map above you. Go to Control Panel (Click the word "Earth"): Control line, and click the icon that looks like a bracketed circle [O]. The map will place you at its center.
Make sure Control Panel: Control is set for surface winds (Sfc.)
Click on your location on the map and write down the speed and direction information that is displayed above the word "Earth." In the display, the direction is reported in degrees (240), where 0 degrees = North, so 180 degrees would be South, 90 degrees would be East and 270 would be West.)
3. Consider: What would make a difference between your local measurements and those of your region as recorded on the wind map? Consider the impact of landscape, terrain (larger scale hills and valleys), the proximity of your site to an ocean or a large lake and more. What slows wind up or allows it to go without interruption?
If you are using the balloon release technique to measure winds, check the field for obstacles that ight trip the person capturing the balloon.
- Project was published on:June 3, 2014