Visualizing Sun Position of the Seasons

Chris Sinton
,
University of Redlands
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Summary

The goal of the exercise is to help students visualize and better understand how the sun changes apparent position over the course of the seasons.

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Context

Audience

This exercise is used in Physical Geography, a 200-level lab course that is a core course for Environmental Studies majors. It also fulfills the science+lab foundation requirement, so a proportion of students are non-majors.

Skills and concepts that students must have mastered

Students will have read about the change in the position of the earth's axis as it revolves around the sun and how this affects the global energy cycle. Students will need to know how to use a compass.

How the activity is situated in the course

After I lecture on global insolation and changes with seasons, I take the students outside to conduct the exercise.

Goals

Content/concepts goals for this activity

The goal of the exercise is to enable students to visualize the changes in position of the sun over the course of the seasons.

Higher order thinking skills goals for this activity

I would like students to be able to relate the changes in apparent sun position with seasonal changes in weather and to visualize earth-sun relations in locations at latitudes different from the school.

Other skills goals for this activity

Students need to work in pairs or groups of three

Description of the activity/assignment

Students are first assigned reading from the textbook (Strahler and Merali, Visualizing Physical Geography) to present the concepts of the global energy balance, including the role of greenhouse gases. In class, I go over the concepts and work with the class to figure out how to calculate solar elevation angle at a given latitude at different dates. Prior to class, I had visited the website of the University of Oregon Solar Radiation Monitoring Laboratory (http://solardat.uoregon.edu/SunChartProgram.html) to generate a Sun chart for my latitude. I have copies of this chart ready. Outside, the students use a compass to find the azimuth and elevation for the sun's arc for the solstice and the equinox. They are asked to trace these different arcs using their arms to get a sense of the difference. Students are then asked to take a compass bearing of the sun's azimuth and use the sun chart to determine the time. (Usually, it is one hour off - they need to figure out why - daylight saving)

Determining whether students have met the goals

There is no written evaluation. I evaluate based on my interaction with each pair or group.

More information about assessment tools and techniques.

Teaching materials and tips

Other Materials

Supporting references/URLs

Sun chart program - to generate a sun chart for any location