Earth Sun Relationships
Terms: Subsolar Point, Solstice,
Equinox, Latitude, Circle of Illumination, Plane of the Ecliptic, Sun Angle,
Insolation, Declination, Direct Rays, Tangential Rays
Questions (18 Points)
1. Using Figure
1 and a ruler, draw and label: (4)
North and
South Poles
Equator
Tropics of
Cancer and Capricorn
Circle of
Illumination
Arctic and
Antarctic Circles
Shade in
Portion of Earth experiencing Darkness
2. For each of the following
dates, list the latitudes at which the direct and tangential rays touch
the earth? (4)
June Solstice
December
Solstice
March Equinox
September
Equinox
3. Using Figure
2, graph the total daily insolation in watts/square meter (on Figure
3) for the following places: (7)
North Pole
New York
Tropic of
Cancer
Equator
Tropic of
Capricorn
New Zealand
South Pole
(Please use a different colored
pencil for each line.)
(Figure
4 is
another representation of this same concept.)
4. Using the following equation,
calculate the sun angle on December 21 for the following locations: (3)
a. Duluth:
46.5 Degrees North Latitude
b. Phoenix:
33 Degrees North Latitude
c. Auckland
New Zealand: 36.5 South Latitude
Sun angle = 90 Degrees - (Degree difference between latitude and subsolar point)
Subsolar Point on December 21 is 23.5 Degrees South Latitude