Name:
Aim 28: What causes seasons?
Date:
Since Earth’s orbit is in the shape of an ellipse, the Earth is closer to the sun at one time than it is at other times. Earth is
closest to the sun in January, so we expect it to be the warmest month. However, January is our coldest month. Why is that?
A) The Earth’s Tilt
The Earth is tilted at a ___________ angle on its axis, and the axis always points in the same direction as the Earth
revolves around the Sun. Because of this tilt, a few things are affected:
1. The tilt of Earth’s axis causes the ________________ at which the Sun’s rays strike Earth’s surface to
__________ through the year.
2. The tilt also causes the number of hours of _________________ to vary. The hemisphere tilted
___________________ the sun will receive sunlight at __________________ angles than the hemispheres tilted
______________ from the sun
3. Because of the Earth’s tilt, areas in the Northern and Southern Hemispheres will both experience
____________________ but at _______________________ times of the year.
B) How does the Angle of Sunlight affect the hours of daylight?
During ______________________ in the northern hemisphere, the Sun is __________________ in the sky throughout
most of the day compared to other times of the year. The Sun is ____________________ in the sky during
__________________. Sunlight is more intense and warms Earth’s surface more when striking the surface at higher
angles than at lower angles.
Why are there shorter shadows casted by the sun in June
and longer shadows casted in December?
The winter sun is the ____________ in the sky, casting
very long shadows. The summer sun is very ___________
in the sky, casting very short shadows
Do you think areas around the equator experience drastic
changes in weather and daylight? Why or why not?
C) What is the difference between a Solstice and an Equinox?
Solstice
What
is it?
When the sun is at the ______________________
When the Earth’s axis _________________ point
angular distance from the Earth’s equator. The Earth’s
toward or away from the sun. The number of daylight
axis is tilted directly ______________ the sun or
hours (12) and nighttime hours (12) are
______________ from the sun.
_____________ length!
1. Summer Solstice = __________________
1. Spring Equinox
(Northern Hemisphere)
When
does it
occur?
Equinox
o
___________________ day of the year
o
___________ hours of daylight, direct sun
o
Northern Hemisphere is at its maximum tilt
o
a. _____________ in Northern Hemisphere
b. _____________ in Southern Hemisphere
2. Fall Equinox
_____________ the sun
a. _____________ in Northern Hemisphere
The summer solstice in the Southern
b. _____________ in Southern Hemisphere
Hemisphere is December 21st
2. Winter Solstice = ____________________
(Northern Hemisphere)
o
___________________ day of the year
o
__________ hours of daylight, __________
direct sunlight
o
Northern Hemisphere is at its maximum tilt
_______________ from the sun
o
The winter solstice in the Southern
Hemisphere is June 21st
1. What do you notice about the dates of the Solstices and Equinoxes in the Northern and Southern Hemispheres?
2. Match each term in Column A with its description in Column B. Write the letter in the space provided
3.