Solar Storms and You!
Activity 7: Magnetic Storms from the Ground
Introduction
Coronal Mass Ejections and other solar storms can buffet the magnetic field
of the Earth with clouds of charged particles and magnetic fields. Not
only do these interactions affect the large scale properties of the geomagnetic
field, but their affects can also be easily detected on the ground. During
the last 100 years, many 'magnetic observatories' have been commissioned
around the world to monitor the Earth's surface field conditions. These
have been, historically, important for navigation by ships at sea. The
data from these observatories can also be used to examine what happens
when solar storms arrive at the Earth.
Objective
By analyzing graphical data, students will become familiar with the Earth's
changing magnetic field through solar storm activity plots.
Materials
5 station magnetic field data sheet for Students and
Teacher's Answer Key
Calculator
Map of Canada for Students and Teacher's Answer Key.
Procedure
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Plot the location of each magnetic observatory on a map of Canada.
Label each station number next to the plotted point.
-
Analyze the magnetic intensity plot for each station and identify
the difference between stable activity, and the largest difference in change
of activity, either positive or negative, on the plot.
-
Find the percentage change for each station. Round the answer to
the nearest hundredth of a percent. Write the number below the location
of the station on the map. See the Teacher's Answer Key.
-
Discuss and work the following questions and procedures: a) Where
are the largest magnetic changes located for this event? b) Draw a circle
around the three stations with the largest magnetic changes. Did the largest
changes occur at the same time? Explain. c) On the data sheet, organize
the plots in order from the largest to the smallest change. Do you see
any patterns? d) Organize the magnetic intensity plots according to similar
shapes. Are there any trends?
Example
For Fort Churchill the normal 'stable' level was 59.3 and the largest deflection
happened near 8:00 at about 59.8.
% = 100 x (max - stable)
stable
% = 100 x (59.8 -59.3)
59.3
or 0.85 percent
Conclusions
Students should have learned that the Earth's magnetic field does not remain
constant in time, but can change its strength. By investigating and
plotting data, students should have revealed the changes in the Earth's
magnetic field due to solar storms. From this, students will locate those
regions of the Earth that are most susceptible to solar storms.
Related Web Resources
Visit the IMAGE/POETRY Magnetic
Observatories page and from there, you can look at recent data on the
earth's ground-level magnetic field from the observatories 'minute to minute'
realtime measurements.
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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.
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