Windward Ho!

Will crouched low, peering through the willows at the grazing antelope. It tugged gently on the tips of the young grass shoots that were pawed loose from earlier digging. Will had been instructed to always stay downwind of animals when tracking and trying to get closer to them. The antelope's alert head raised at the sound of a snapping twig underfoot as Will cautiously ventured closer. The tumbling dark clouds overhead momentarily broke his concentration. He recalled his mother's caution that a calm peaceful evening could quickly change by an approaching storm.

AIR IN MOTION

What carries the sound of a snapping twig? How does a storm come racing through your town? What creates the angle of campfire smoke? Earth is surrounded by a protective blanket of air - the atmosphere - that is constantly moving. Moving air is called wind. You might feel a calm, gentle breeze on your face on a lazy summer evening, or experience the fury of a thunderstorm. Wind can cool you off when you're hot, or fuel forest fires caused by summer lightning. Wind can cause relief or it can cause disaster. Learning about wind can help you to know more about the weather.

STUDYING WIND

Meteorologists are weather scientists that observe and forecast weather. Wind is one of the important weather conditions that they study. Knowing wind direction and wind speed can help them predict how the weather will change. On this page you will experiment with wind direction.

GETTING DIRECTIONS

How do you observe the direction of the wind? Do you notice leaves as they are blown during the autumn? How important is knowing wind direction when flying a kite? Wind vanes have decorated barns, houses, and other public buildings for centuries. They turn with the wind, showing the direction of the moving air. You may have seen windsocks at airports or used as colorful decorations on people's homes. By observing wind vanes, meteorologists know the wind direction and can predict how this moving air will affect the weather conditions in an area.

DO IT!

Below you will find out how to make a simple wind vane that's easy to use.

Materials:

• 4 x 6 inch index card
• Ruler
• Straight pin
• Plastic drinking straw
• Pencil
• Clay
• Marker
• Small bead
• Directional compass
• Fastening device (stapler, tape, or glue)
• Paper clips
• Compass

Procedure:

1. On the 4 x 6 inch index card, draw a vertical line that divides the card into a 4 x 4 inch piece and
   a 4 x 2 inch piece.
2. Cut the card in the two pieces. On the 4 x 2 inch piece, cut an arrowhead from one end. The remaining part should be in the shape of an arrow tail.
3. Using a stapler, tape, or glue, attach the arrowhead and tail to the opposite ends of the drinking straw.
4. To find the exact center, balance the straw on your finger. Stick the straight pin through the balanced center of the straw.
5. Thread the small bead onto the pin, then stick the pin into the eraser head of a pencil.
6. The pencil can either be held in your hand in the wind, or you can attach your wind vane to a wooden dowel or support base.
7. Paper clips may be added near the arrowhead of your vane to balance your straw.

You will use the remaining 4 x 4 inch piece of index card to make a wind direction base.

1. Measure two inches on each edge of your paper and draw lines that will divide it into quarters.
2. Draw straight lines through the center point to the opposite corners of your paper.
3. Label the directions on your chart. North should be at the top, south at the bottom, west to the left, and east to the right.

Using Your Wind Vane

1. To use your wind vane, place a directional compass on top of your wind direction chart. Locate magnetic north and turn your paper so the line on the chart lines up with the compass arrow.
2. Hold your wind vane in an open area where wind is blowing. The direction of the arrow will indicate the direction the wind is blowing.