Earth Science: Geology, the Environment, and the Universe

Chapter 30: Stars

Problem of the Week

Cyclic Nature of Solar Events

After studying the information in Chapter 30, students should be familiar with the events that occur on the Sun – sunspots, prominences, flares, ejections, etc. They should also know that these events influence the solar wind, which in turn affects Earth in various ways – climate, geomagnetic storms, electronic activity, spacecraft flight, aurorae etc. Finally, they should have some idea that there are cycles in solar activity.

Analysis of the Graph:

1. What is the relationship between these two phenomena as shown on the graph?
   
   Students should notice that the peaks and lows of sunspot activity and CMEs coincide with each other.



2. Notice that there are peaks for both events and troughs for both events, what is the average number of years between peak years?
   
   Should be about 10–11 years



3. Notice that there is a portion of the graph, between 1850 and about 1875, where CME events are not shown. What might be a reason for the absence of data during this time period?
   
   Answers will vary, but most students should infer that data collection technology was not in existence at that time or that CMEs had not been discovered or recorded until about 1875.



4. What other information does this graph give you?
   
   Student answers will vary.
   
   They may talk about the average low points.
   
   They could find the difference between the largest number of sunspots and the lowest number of sunspots.