Seasons
How does the A of I compare between morning and midday? Between morning and evening?
It starts large, goes to small and at evening gets large again.
What would happen to the seasons if the tilt were less than 23.5 degrees?
They would be less extreme
What would happen to the seasons if the tilt were more than 23.5 degrees?
They would be more extreme
True or False: Equal hours of day and night occur during an equinox.
True
True or False: The summer solstice occurs when the northern hemisphere recieves more direct sunlight than the southern hemisphere.
True
What are day and night caused by?
Earth's rotation on its axis
When does fall begin in the Southern Hemisphere?
Spring Equinox
What are the three motions of the Earth and what do they do?
1. Rotation - CCW, Sun appears to move from east to west, yields day and night 2. Revolution - Occurs every 365.25 days, a flat surface drawn through Earth and sun called the ecliptic plane, nearest to the sun = perihelion, farthest from the sun = aphelion 3. Precession - Makes Earth tilt 23.5 degrees from the perpendicular, axis always points towards Polaris (north star)
What have you noticed about the temperature changes from morning to evening?
As the sun gets closer to being overhead, it gets warmer (noon).
How would the change in direction affect what we call the north star?
A different star would be our North Star
Why does the earth have seasons?
Because earth's axis is tilted as it moves around the sun
Why does direct sunlight have more energy than less direct sunlight?
Direct sunlight has less atmosphere to go through, so less of the energy gets lost.
If you compared the A of I at midday during summer and winter, which season would have a larger A of I?
Dring winter the A of I will be larger because we are tilted away from the sun and vice versa.
When does fall begin in the northern hemisphere?
Fall Equinox
When does spring begin in the southern hemisphere?
Fall Equinox
When does the sun set in the west?
Fall and Spring Equinox
True or False: The seasons are not influenced by the tilt of the earth on its axis.
False
True or False: The seasons on earth are caused by changing distances between the earth and the sun.
False
What role do you think the A of I plays in determining seasons?
If the A of I is larger, it will be colder (winter) and so if it is shorter, it will be warmer (summer)
How would you explain why North America is warmer in summer and colder in winter.
In the winter it is tilted away from the sun and in the summer it is tilted towards.
Explain how the motion of Earth causes day and night.
It rotates on its axis, so one side is always in sunlight.
What will North America experience when the Earth's northern axis is tilted toward the sun? (rays and daylight)
More direct rays and more daylight
When does spring begin in the Northern Hemisphere?
Spring Equinox
When are there equal days and nights everywhere?
Spring and Fall Equinox
When does the plane of the ecliptic interesct the equator?
Spring and Fall Equinox
When does the sun rise in the east?
Spring and Fall Equinox
When is the sun directly above the equator?
Spring and Fall Equinox
When do locations above the Arctic Circle receive 24 hours of sunlight?
Summer Solstice
When does summer begin in the Northern Hemisphere?
Summer Solstice
When does the Northern Hemisphere receive the longest amount of daylight?
Summer Solstice
When does the plane of the ecliptic intersect the tropic of cancer?
Summer Solstice
When does the southern hemisphere receive the shortest amount of daylight?
Summer Solstice
When does the sun rise north of east?
Summer Solstice
When does the sun set north of west?
Summer Solstice
When does winter begin in the southern hemisphere?
Summer Solstice
When is the plane of the ecliptic north of the equator?
Summer Solstice
When is the sun directly above 23.5 degrees N?
Summer Solstice
When is the sun directly above the Tropic of Cancer?
Summer Solstice
When is there no sunrise at locations south of the Antarctic Circle?
Summer Solstice
How does the angle of incidence affect the length of your shadow?
The larger the A of I is, the longer your shadow is.
How might the change in direction affect the seasons?
The seasons would be opposite
How does the sun's position above the horizon affect the angle of incidence?
When it is higher the Angle will be shorter, and when it is lower, the Angle will be longer.
When does an equinox occur? (where is earth's axis tilted, towards the sun, away, neither etc.)
When neither end of Earth's axis is tilted toward or away from the sun
How does the A of I change over the course of a year? How does your answer vary for different locations on Earth?
When the area is tilted away, the A of I will be higher except in the equator area where the sun and A of I stay pretty constant.
Why is it winter in the southern hemisphere when it is summer in the northern hemisphere.
When the northern hemisphere tilts up to go into winter, the southern hemisphere receives the sunlight and vice versa.
When do locations below the Antarctic Circle receive 24 hours of sunlight?
Winter Solstice
When does summer begin in the southern hemisphere?
Winter Solstice
When does the Northern Hemisphere receive the shortest amount of daylight?
Winter Solstice
When does the plane of the ecliptic interesect the tropic of capricorn?
Winter Solstice
When does the southern hempisphere receive the longest amount of daylight?
Winter Solstice
When does the sun rise south of east?
Winter Solstice
When does the sun set south of west?
Winter Solstice
When does winter begin in the Northern Hemisphere?
Winter Solstice
When is the plane of the ecliptic south of the equator?
Winter Solstice
When is the sun directly above 23.5 degrees S?
Winter Solstice
When is the sun directly above the tropic of capricorn?
Winter Solstice
When is there no sunrise at locations north of the Arctic Circle?
Winter Solstice