Solar Storms and You!

Activity 5: Solar Activity and Coronal Mass Ejections


The Sun constantly emits matter into space in the form of a more or less steady solar wind. From time to time the Sun also ejects individual clouds of gas in an event called a Coronal Mass Ejection, or CME. CMEs can cause storms in the environment of the Earth that can have harmful impacts on humans working in space, on communication satellites, and many other aspects of our technology dependent society. For this reason, scientists look for many clues as to how and when the next one may happen to provide us with advanced warning.


Students will construct a graph to compare the sunspot cycle with Coronal Mass Ejections (CMEs).


Graph paper
Colored pencils
Student worksheet
Teacher notes on the graphing calculator, Part 1 and Part 2.
Graphing calculator


  1. Students will use the graphing calculator to create the graphs for the sunspots and the CMEs. Students will graph the sunspots and the CMEs on graph paper. Note: Using different colors to depict each graph will allow for ease when comparing the two graphs.
  2. Students compare the two graphs. Location of the maximums, the minimums, and the time frames are the key components. Have the students determine if there is a correlation.
  3. Discuss the possible relationships that the students locate. Among the things to consider are: - How well does the CME activity follow the sunspot cycle?- Do the maximums and the minimums happen at about the same time?

Key Terminology

Solar Wind: A flow of matter from the surface of the Sun which passes through interplanetary space.
CMEs: Coronal Mass Ejections are sudden ejections of matter from the Sun's outer layers.


Cme activity should follow rather closely the sunspot cycle, but the correlation in exact counts may not be precise. This is probably because CMEs happen in layers of the Sun that are much higher above the solar surface than the sunspots. The CME curve seems to have a longer, flatter minimum than the sunspot curve and its center is offset from the sunspot minimum by 2-3 years earlier. CME activity may decline to a minimum faster than sunspots after sunspot maximum.

Related Web Resources

The Mauna Loa Solar Observatory has an archive of MPEG movies of major CMEs during the last 10 years. At the end of the main page is a link to their deep archive of solar storms dating from 1980.

The National Geophysical Data Center has an archive of sunspot data ( daily, monthly, yearly averages) that goes all the way back to the 1600s. Click on 'Sunspot Numbers' in their list and the FTP session will start.

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This activity was developed by the NASA, IMAGE/POETRY 
Teacher and Student Consortium. 
For more information, and a list of other resources, visit 
the IMAGE/POETRYweb site.