Sunrise, Sunset Worksheet Name_____________________________________
Using your computer, go to the online “Motions of the Sun” simulator found at
http://astro.unl.edu/naap/motion3/animations/sunmotions.html. Once there, begin by
setting the observer’s latitude to your latitude by adjusting the “arrow bar” across the
world map on the right. Next, familiarize yourself with the simulator by experimenting
with the “time and location controls” and the “animation controls.” Use the controls to
manipulate the motions of the sun and answer the following questions:
1. Give the direction (N, S, E, W, NE, SE, NW or SW) that the sunrise/sunset is
located on the following days:
March 21:
June 21:
September 21:
December 21:
2. How long (in hours) is daylight on each of the following dates:
March 21:
June 21:
September 21:
December 21:
3. What do you think is causing the difference in day lengths?
4. What effect do you think the length of day will have on temperature?
Now go to the online “Seasons and Ecliptic” simulator found at
http://astro.unl.edu/naap/motion1/animations/seasons_ecliptic.html. Once there, set the
observer’s latitude to your latitude by adjusting the stick figure on the globe on the right
and familiarize yourself with the simulator by experimenting with the controls. Then, use
the controls to manipulate the Earth’s orbit, notice the changes to the incoming sunlight
and answer the following questions:
1. What is the sun angle (Sun’s altitude) on the following days:
March 21:
June 21:
September 21:
December 21:
2. Describe/draw the sunbeam spread for each of the following dates:
March 21:
June 21:
September 21:
December 21:
3. What effect do you think varying Sun angle and sunbeam spread will have on
temperature? Why?
Sunrise, Sunset Worksheet Name___KEY______________________________
Using your computer, go to the online “Motions of the Sun” simulator found at
http://astro.unl.edu/naap/motion3/animations/sunmotions.html. Once there, begin by
setting the observer’s latitude to your latitude by adjusting the “arrow bar” across the
world map on the right. Next, familiarize yourself with the simulator by experimenting
with the “time and location controls” and the “animation controls”. Use the controls to
manipulate the motions of the sun and answer the following questions:
5. Give the direction (N, S, E, W, NE, SE, NW or SW) that the sunrise/sunset is
located on the following days:
March 21: E
June 21: NE
September 21: E
December 21: SE
6. How long (in hours) is daylight on each of the following dates:
March 21: 12 hours (or close)
June 21: Should be a value greater than 12 hours (will vary with latitude)
September 21: 12 hours (or close)
December 21: Should be a value less than 12 hours (will vary with latitude)
7. What do you think is causing the difference in day lengths?
Ahrens (2015), clarifies this phenomenon by comparing the Sun in June, which
rises in the northeast, rises to a higher position in the sky at noon and sets in the
northwest to the sun in December, which rises in the southeast, rises to a lower
position in the sky at noon and sets in the southwest, thus following a shorter
apparent path.
Middle school students are familiar with calculations of speed:
speed = distance ÷ time
If the apparent speed of the sun across the sky doesn’t change, but the time it
takes to traverse the apparent path does, then the distance must change as well.
Hence, a logical response is that the Sun follows a shorter apparent path across
the sky in December than it does in June (see figure below). Students can model
and verify this with the “Motions of the Sun” simulator.
Image credit: NOAA
8. What effect do you think the length of day will have on temperature?
A location on Earth that is exposed to solar heating for a longer time period in
June will be warmer than when it is exposed to solar heating for a shorter time
period in December.
Now go to the online “Seasons and Ecliptic” simulator found at
http://astro.unl.edu/naap/motion1/animations/seasons_ecliptic.html. Once there, set the
observer’s latitude to your latitude by adjusting the stick figure on the globe on the right
and familiarize yourself with the simulator by experimenting with the controls. Then, use
the controls to manipulate the Earth’s orbit, notice the changes to the incoming sunlight
and answer the following questions:
4. What is the highest Sun angle (Sun’s altitude) on the following days:
March 21: These answers will vary with latitude, however, the highest Sun angle
June 21: will be in June, the lowest Sun angle will be in December and the Sun
September 21: angle for March and September should be the same and between the June
December 21: and December readings. You can check your student’s accuracy at
http://www.esrl.noaa.gov/gmd/grad/solcalc/azel.html
5. Describe/draw the sunbeam spread for each of the following dates:
March 21:
This will also vary with latitude.
Examples shown are for 40º N.
June 21:
March and December should look
the same. The beam is most
September 21: spread out in December and most
compact in June.
December 21:
6. What effect do you think varying Sun angle and sunbeam spread will have on
temperature? Why?
Ahrens (2015) explains “Sunlight striking the Earth at an angle spreads out and
must heat a larger region than sunlight impinging directly on the earth. Everything
else being equal, an area experiencing more direct solar rays will receive more
heat than the same size area being struck by sunlight at an angle” (p. 47).
References
Ahrens, C.D. (2011). Essentials of Meteorology: An Invitation to the Atmosphere 6th
Edition. Cengage Learning, Boston Massachusetts.
Resources
NOAA solar position calculator - http://www.esrl.noaa.gov/gmd/grad/solcalc/azel.html
