Cloud Cover

What We're Doing

In this activity, you will measure and record the percentage of cloud cover at your field site.

Why We're Doing It

Many variables can affect the types of creatures and soil you find at your field site. Cloud cover is one of those variables. This activity will show you how to measure the cloud cover at your field site.

Making the connection:

  • By doing this activity along with Soil Biodiversity, you can discover what effect cloud cover has on the types of creatures and on the soil at your field site.
  • By doing this activity with Air Temperature, you can see how cloud cover affects air temperature.
  • By doing this activity with Soil Properties, you can see how cloud cover affects soil properties.

Getting Our Hands Dirty

Hypothesize

What is the percentage of cloud cover at your site?

Plan it!

  • If you haven't already done so, choose a field site and map it in your field journal.
  • If you are doing this activity along with Air Temperature and Soil Properties, you should do all of the activities at the same time and place. If you haven't yet done so, decide how often to take cloud cover readings. If you are working with a group or as a class, you should decide together. As you decide, think about these questions:
    • How might your results be affected if you take daily readings?
    • How might your results be affected if you take monthly readings?
    • How might your results be affected if you take annual readings?
    Most scientists would agree that taking readings at least once a week will give you the most accurate record of changes in cloud cover over time.

Do it!

  1. Choose a spot in your field area in which to observe the sky. If you are also measuring the air and soil temperature, you should measure the cloud cover at the same time and place.
  2. Look at the Environmental Factors worksheet . Imagine that the visible sky is a circle divided into four pieces, just like the circle on your worksheet. Each piece, or quadrant, represents 25% of the whole sky.
  3. Look at one quadrant of the sky. Is it completely covered by clouds? Is it completely clear? Or somewhere in between?
  4. Sketch the cloud cover for that quadrant on the Environmental Factors worksheet .
  5. Look at each of the other three quadrants. For each, sketch in the cloud cover you see.
  6. Estimate the total cloud cover. If one quadrant is completely filled with clouds, then the cover for that day is 25%. If two are covered, then the cloud cover is 50%. If three are covered, then the cloud cover is 75%. If all four are covered, then the cloud cover is 100%.

Record it!

Remember, be sci-wise!

  • Take the cloud cover readings at the same time of day each time.
  • What if a quadrant has some clouds in it, but isn't filled with clouds? To be counted, a quadrant must be more covered with clouds than not. Do not count a quadrant that has some clouds in it, but is less than half-filled with clouds.

Thinking About It

  • What was the percentage of cloud cover at your site?
  • Based on the data you collected, was your hypothesis correct or incorrect?
  • How did the cloud cover change at your site over time?
  • How might the time of day have affected the data?
  • What patterns or links did you notice between the weather and the cloud cover?
  • What patterns or links did you notice between the season and the cloud cover?
  • What relationship did you find between the cloud cover and air temperature?
  • What relationship did you find between the cloud cover and soil temperature?
  • If you continued recording the cloud cover for a whole year, what differences would you expect to find?
  • Complete this section on the Factors That Affect the Soil Overview worksheet .
  • Looking at the bigger picture, how might the data you collected here help you to answer your research question?

Still Interested?

If you liked this activity, you might want to try these:

  • Learn the meteorological terms for different percentages of cloud cover. For example, a day with 100% cloud cover is considered overcast.
  • Record the cloud cover each hour for a day. Does the percentage change? Would you expect the same thing to happen every day?

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