Trends of Snow Cover and Temperature in Alaska

Students measure snow depth at Shageluk, Alaska

Image courtesy ALISON

To compare NASA satellite data observations with student surface measurements of snow cover and temperature
Grade Level: 9-12
Estimated Time for Completing Activity: one class period
Learning Outcomes:
  • Students will learn how to find data correlations.
  • Students will learn how to make scientific predictions.
  • Students will learn about data collection methods.
  • A working knowledge of the Scientific Method
  • Excel spreadsheet technology
  • Computer
  • Map of Alaska
  • Graph paper
  • Colored pencils
  • Overhead projector
Lesson Links:

The Alaska Lake Ice and Snow Observatory Network (ALISON) is a network of 22 ground stations around the state of Alaska. Each site records and reports observations of surface parameters (such as snow or ice depth and temperature), and the data becomes available on the ALISON Web site. The site at Shageluk Lake was established in January 2003 and is operated by high school students.

NASA satellite missions also monitor surface conditions from space. This method is called remote sensing. One project, the International Satellite Cloud Climatology Program (ISCCP), has been studying global atmospheric and surface climatology for over two decades. In this lesson, ISCCP data and ALISON data will be compared to examine trends in snow cover and temperature in Alaska.


First, students will gather historical snow cover and temperature data from the MY NASA DATA Web site for the Shageluk Lake site (62.41N,159.34W):

1) Access the MY NASA DATA Live Access Server Advanced Edition in the lesson links above.
2) If you are not automatically prompted select ‘Choose Dataset’ then select Cryosphere, and then Monthly Snow Ice Amount (ISCCP).
3) Select ‘Time Series’ from the options to the left of the screen.
4) Enter the coordinates for Shageluk in the boxes to the right of the map. Be sure to select the ‘Update Plot’ radio button from the menu at the top to view your plot.
5) Notice the seasonal variation (trend) in snow cover. Save or print the graph before closing the window. A text file of the data is also available by clicking on ‘Save As’ from the menu at the top, selecting ‘Save As’ from the drop down menu, verifying your time range and then clicking on ‘Ok’. This will save a file to your computer to import in to a spreadsheet for graphing or plotting by hand.

6) Return to the Live Access Server start page by clicking on ‘Choose Dataset’.
7) This time, select Land Surface, Surface Conditions, then Monthly Surface Clear-sky Temperature (ISCCP).
8) If necessary, repeat steps 3 and 4 to select the time series for Shageluk. Be sure to select the ‘Update Plot’ radio button from the menu at the top to view your plot.
9) The units will be shown in degrees Kelvin. If you wish to convert it to Fahrenheit or Celsius, go back and use the Evaluate Expression box found by clicking on ‘plot Options’ and clicking on the question mark to learn how to convert your units. Save or print the graph before closing the window.

Next, students will gather the ground measurements from the ALISON Web site for Shageluk Lake:
1) Access the ALISON Web site using the link above.
2) Click on Data Download, ALISON – Shageluk data. A spreadsheet should appear showing the recorded data. Focus on the snow or ice depth measurement (presence) and the snow or ice surface temperature.
3) Graphs of the Shageluk data are also available. Return to the ALISON home page, click on ALISON sites, Shageluk, Current or Past data.


1. What trends or coorelations do you see in the ISCCP snow cover and temperature data? Can you relate the data to seasonal variations? Is the data what you expected? What conclusions can you make regarding the climatology of the Shageluk Lake area?

2. Do you see the same trends in the ALISON snow and temperature data? Does the data follow your climatological prediction? Can you plot the differences on a graph?

3. Discuss the general differences between ground measurements and satellite observation methods. Could they explain some of the difference you may see?


1. Set up a ground observation site at your school or home. For assistance or guidance, we recommend contacting the GLOBE organization (see link above). Begin to record surface temperature and snow cover at your site on a regular basis to be able to compare your data with satellite observations from MY NASA DATA.

2. If you already have a weather station at your school site, explore the Live Access Server to find climatological satellite data for your location for any parameters of interest. Compare the data with your local observations using a similar procedure.

Lesson plan contributed by Joyanne Hamilton, Shageluk, AK

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