# Learning Exercise

## Solar Flares and Sunspots

This lesson addresses skill development for measuring sizes of sunspots and making comparisons relevant to the size of the Earth.. It also examines cyclical changes in magnetism of sun spots and the impact on Planet Earth.
Course: Earth and Space Systems
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#### Spaceweather.com

News and information site about the sun-earth environment see more

#### Exercise

SOLAR FLARES
SUN SPOTS

OBJECTIVES
1. The student will learn how to write and solve equations that relate real
distance measurements to scaled representations of distances.
2. The student will understand the magnitude of the Earths magnetic field.
3. The student will learn that sun spots are dark spots on the sun where
temperatures are lower and magnetic activity is higher.

MATERIALS
For this lesson you will need:
Ruler
Calculator
Color pencils (optional)

PART I  PROCEDURE

1. Go to www.spaceweather.com and find your last birthday under View archives.
Click on the image of the daily sun located to the left of the screen. The
image will be enlarged. On your worksheet, draw and label the sunspots that
2. The diameter of the sun is 1.4 million km (870,000 miles). Using this scale,
calculate the size of the sunspots for your day.
3. The diameter of the Earth is (roughly) 12,800 km or 8000 miles. Calculate
how many Earths can fit into your sunspot.
4. Calculate the number of Earths that would fit across the suns equator.

PART II  PROCEDURE

1. Visit http://solarscience.msfc.nasa.gov/feature1.shtml
to complete the worksheet for Part II to get a basic understanding of sunspots.

2. Complete the remainder of the worksheet for Part II to get a basic
understanding of sunspots, solar wind, and the Earths magnetic field.

WORKSHEET PART I

1a) In the Sun below, draw the sunspots for your day.

1b) Size (in km) of your sunspot(s):

1c) Number of Earths that can fit in your sunspot:

1d) Number of Earths that will fit across the Suns equator:

PART II WORKSHEET
Sunspots and Geomagnetic Storms
Can events that happen on the Sun 93,000,000 miles away really have an effect on
Earth? You have seen pictures of sunspots. Although they appear as small dots
on the solar surface, they can have a surprisingly strong effect on what is
known as "space weather."
Inthis activity you'll find out what sunspots are, when they occur, and how
they affect both space weather and life here on our home planet.
1. What is a sunspot?

2. How does the magnetism of sunspots compare with the Earths magnetic field?

3. Where is the magnetic field strongest within a sunspot?

4. Next, you'll find out about the Sunspot Cycle
a. What do monthly averages show about the number of sunspots?

b. How long is the solar cycle (in years)?

5. Look at the graph of Sunspot Number to the left of the text. It shows the
average daily number of sunspots for a given year.
a. When was the last peak of sunspot activity?

b. What was the sunspot number at the last peak of activity?

6. Based on your answers to questions 3 and 4, when will the next peak of the
cycle occur?

7. In what year will the current cycle reach its low point (minimum)?

8. To find out what effect sunspots have on our space weather, re-visit the
Space Weather Bureau (http://spaceweather.com/ ) and read today's solar report.
Summarize today's news about the Sun in the What's Up in Space column. Summarize
today's news about effects from the Sun (such as sunspots, flares, auroras, or
geomagnetic storms).

9. Sunspots have been linked to both solar flares (fiery "storms" in the Sun's
atmosphere) and streams of hot, charged particles that are carried away from the
Sun in the solar wind. When they reach Earth's atmosphere, these particles can
trigger geomagnetic storms that can disrupt satellite and radio communications
or even cause power failures. Look at the top of the left column and find
today's reading of the solar wind. What is today's wind velocity? What is the
density of protons in the solar wind?

10. Continue scrolling down the left column to today's (or the most recent)
sunspot number. What is it? How does this number compare to your daily average
estimate for the year 2000 in question 3?

11. Scroll further down the column to the photo of the Sun showing current
active sunspots. Summarize the report of current activity (just below the
photo.)

12. Keep scrolling to the current image of coronal holes. Click on the glossary
link that explains them. What is the connection between coronal holes and the
solar wind?

13. A bit further down the left column, you'll see NOAA forecasts for solar
flares. What is the probability of medium-sized (M-class) and major (X-class)
flares over the next 24 and 48 hours?

14. Finally, to bring space weather closer to home: Scroll to the geomagnetic
storm forecast. Click on the glossary links explaining the three categories
(active, minor storm, major storm). What is the probability of each kind of
geomagnetic storm over the next 24 and 48 hours? (Give values for both mid- and
high-latitudes.)

#### Technical Notes

Students should be able to use calculators and have access to the Internet

#### Requirements

Students should be familar with the basics of the metric system, understand the concept of diameter, and have an understanding of the concept of "average".

#### Topics

solar flares and sunspots
CA Standard 8.4