Nephoscopes

Opening Discussion

Ask your students if they have ever looked at clouds before.  Have they ever seen “shapes” in the clouds?  What sorts of things have they seen?  Aside from the shapes we can imagine seeing in them, are there other things that clouds can tell us? Encourage a discussion about how the shape, and movement of clouds can give us clues as to the weather that is in our near future.

The Challenge

Create your own cloud viewer and figure out what direction the wind is blowing.

Doing the Activity

1. Divide your class into teams of 2 for this activity.
2. Each team will need a mirror, scissors, a piece of construction paper and a pen, pencil or marker.
3. A nephoscope is simply a mirror that the user points facing North. To construct this cloud viewer, teams should cut a piece of paper that is the same size as the mirror, then they should cut a large hole in the middle of the paper.  Next, tape the paper to the reflective side of the mirror, so they can see the mirror through the hole in the paper. Finally, write “N” at the top (see Figure 1).
4. Bring the teams outside and have them place their nephoscopes on the ground with the reflective side facing up toward the sky.  Ask them to look at their cloud viewers and see what they notice.

Let’s Talk About It

After a few minutes of using their cloud viewers, bring the whole group together to talk about what they observed. What did they notice when they looked at the clouds through their viewers? Is there a way they might use these instruments to tell them which direction the wind is blowing? How might that be helpful? This discussion should only last a few minutes.

Depending on the age of your students, you may want to have a discussion about the directions North, South, East and West.  Ask your students if they know some of the directions that the wind might blow and have them name at least the four mentioned above.

Nephoscopes are used by scientists to determine the direction, altitude and speed that clouds are moving. This nephoscope is more simple and just tells the direction that clouds are moving, but this can be useful information. Wind at ground level can swirl around because of obstacles like hills and buildings, so it is sometimes difficult to tell the true direction of the wind. By looking at the direction the wind is traveling higher in the atmosphere, we can determine where any weather (like clouds in the distance) is coming from.

Build On What They Talked About

After the group discussion, have teams return to their cloud viewers, but this time ask them to all place their viewers on the ground with the “N” facing North. Ask them to now look at their viewers and figure out which direction the wind is blowing. If, for example, they look in their mirror and see the clouds above them moving from the bottom of the mirror up toward where the “N” is written, then the wind is blowing to the North, from the South. Come to an agreement among the group as to which direction the wind is blowing in.