Patterns in High Cloud Coverage

image of various types of high altitude clouds.
To plot and analyze data for high cloud coverage from a specified location and determine whether or not a pattern exists
Grade Level: 6 – 8
Estimated Time for Completing Activity: 50 minutes
Learning Outcomes:
  • Students will locate real NASA satellite data resources on the Internet.
  • Students will be able to create and use a graph to read and analyze data.
  • Students will be able to conclude information based on the graphs they produce.
  • Familiarity with accessing websites on the Internet
  • Familiarity with GPS or resources to find location
  • Basic familiarity with Microsoft Excel
  • Graphing skills
  • Computer with Internet access
  • Excel Spreadsheet on computer
  • Lab notebook and pencil
Lesson Links:

Clouds are a collection of water droplets and small ice crystals that are suspended in an atmosphere. The main part of the water cycle that moves water up into the atmosphere is evaporation. This happens when water is transformed from its liquid to vapor state. The oceans are huge sources of water for evaporation.

Clouds form when moisture rises, cools, and changes to water or ice. But what makes the moisture rise into the sky? It can happen in three main ways as depicted in a water cycle diagram (can be seen in the links section):

1. Sunshine: the heat of the sun can cause the air to rise, taking water vapor with it high into the sky.

2. A Front: a cold front will bring cold air under warm air, forcing it to rise, and a warm front will force warm moist air up over the cold air.

3. Mountains: When winds blow against mountains, the moist air is forced upward.

Cloud cover fraction (percentage) represents the fractional area covered by clouds as observed from above by satellites. It is estimated by counting the number of satellite fields-of-view (called pixels, about 5 km across for ISCCP) that are determined to be cloudy and dividing by the total number of pixels in a region about 280 km across.

It is important to take into consideration exactly how clouds affect the world around us. Clouds are an important determining factor in climate in any region around the globe. On hot summer days, it is noticeably cooler when a large cloud passes by. This same idea can be extended to areas that have large amounts of cloud cover throughout a particular season, leading to cooler temperatures while clouds are prevalent. Clouds do this by absorbing and reflecting radiation before it reaches the surface. In the same way, they are able to create a blanket, reflecting radiation back to the surface and keeping warm temperatures in a particular region. These are just two of the ways that clouds affect the world around us. While completing the lesson, think of other ways in which clouds affect our daily lives.


1. To access the location of your school site to use with the Live Access Server, go to the GPS location web site (lesson link). Under Maps, enter your school address, city and zip code, then click the orange and white arrow to submit. If options are displayed, click the address of choice.

2. Look for the box on the left side of the screen that is labeled Information. The address and GPS location should be displayed there. Write down the GPS location (latitude and longitude) in your notebook.

3. Click on the Live Access Server (Advanced Edition) lesson link. Select ‘Choose Datasets’, Select Atmosphere, Select Clouds, Select Cloud Coverage, Select Monthly High Cloud Coverage (ISCCP)

4. A page with multiple radio buttons will appear. Select : Time series (t) and then click on ‘Update Plot’ at the top of the page.

5. Choose the time range of, Jan 1994 thru Jun 2005 and select ‘Update Plot’ if it does not update automatically.

6. You will now save the data in a text file by selecting ‘Save As’ from the top menu, make sure your time range is correct, select ASCII from the drop down menu and click ‘Ok’

6. Highlight Your ASCII file and save it to your desktop. (this can be done by highlighting the data, and choosing ‘Save As’ form the file menu

7. Open Excel. Click on the Data menu, scroll down to Get External Data. Click on Import Text File, Choose your file, and Click to retrieve data.

8. The Import Wizard opens. Choose delimited. Click to finish and import data.

9. Make a chart with Excel. Click Insert. Click on Chart. The Chart wizard opens, Choose line graph. Enter the X and Y Labels Cloud Percentage and Month-Year. Click to finish.

9. Print out data to be pasted in your lab notebook. Answer the questions below.


1. Describe how the graph of cloud cover changes throughout the year. When is the coverage of clouds the greatest? Where is the coverage of clouds the least?

2. Looking at the multiple years of data, is there a stable seasonal pattern?


1. You are on a team that wants to start an airline company. Pick three airports for which you might want to offer flight service. Which type of cloud coverage do you think will matter most to airline company pilots?

2. Use the Live Access Server to determine which airport location has the least high cloud coverage. Also look at which airport has the least low cloud coverage.

Lesson plan contributed by Shay Vanderlaan, Norwalk, California

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