Download 2016 Seasons and Climate

Motion of the Earth
Climates, Seasons, & Days
Earth’s Motion
• Earth has two major types of motion:
• Earth’s Rotation
• Earth’s Revolution
Earth’s Rotation
• The spinning of the Earth on its axis
• the axis is the imaginary line that runs vertically through the
center of the Earth
• rotates from East to West (counterclockwise)
• Rotation of the Earth produces 2 main effects:
• Speed causes the length of a day to be about 24 hours
• Causes daily changes from day to night
• At all times half of the Earth faces the sun, while the other half is in
darkness
• Areas within the Artic & Antarctic circles experience several weeks
of daylight or darkness depending on the time of year
Earth Rotating
Earth’s Revolution
• The movement of Earth around the sun
• Earth’s orbit is the slightly elliptical path that it travels
around the sun
• The sun is not in the center:
• Around January 3rd earth is about 147million km away (closer)
• Around July 4th earth is about 152 million km away (farther)
• Revolution has 2 major effects:
• The time it takes Earth to revolve around the sun once
defines the length of a year
• It takes 365 ¼ days to make one complete revolution
• Every 4th year is leap year to make up for the extra day we gained
• Earth revolves with a tilt of the axis
• The revolution & tilt causes the changing seasons
Earth’s Revolution
How Earth Moves
• In your group, demonstrate the
difference between a rotation & a
revolution.
Changing Seasons
• Earth’s axis is at an angle of 23.5° to its orbit
• The axis always points in the SAME direction as
the Earth orbits the Sun.
• The Northern hemisphere points toward the sun
half of the year & away from the sun for half the
year
• The tilt causes the Earth’s surface to receive
different amounts of solar energy throughout the
year.
Radiation from the Sun
• The hemisphere that is tilted toward the sun
receives more daylight hours and absorbs
more radiation from the sun
• The Sun’s radiation strikes the earth surface
at a higher angle when the hemisphere is
tilted toward the sun
• The higher the angle the more radiation the
earth absorbs creating warmer temperatures
Seasons on Earth
• Which month is receiving the most direct
sunlight?
• Least direct amount
Solstices
• A solstice is the day when the Sun reaches its greatest
distance north or south of the equator
• The day Earth is tilted most toward the sun
• June 21st is the summer solstice (northern hemisphere)
• The most direct rays hit the Tropic of Cancer in the northern
hemisphere causing the northern hemisphere to have warmer
temperatures and more sunlight hours
• Longest day of sunlight for the year
• Daylight gets a little shorter each day after the solstice
• Dec. 21st is the winter solstice (northern hemisphere)
• The most direct rays hit the Tropic of Capricorn in the southern
hemisphere causing the northern hemisphere to have cooler
temperatures and less sunlight hours
• Shortest day of sunlight for the year
• Daylight hours get a little longer each day after the solstice
Equinox
• An equinox is the day the Sun’s rays are directly
above the Earth’s equator.
• During this time equal amounts of sunlight are received
all over the earth with the most direct rays hitting at 90°
at the equator
• March 21st is the spring equinox (northern hemisphere)
• September 22nd is the autumn equinox (northern
hemisphere)
• Seasons are opposites in the Southern Hemisphere
Seasons on Earth
• Earth has seasons because it is tilted as it
revolves
around the sun.
No matter what time of year, which areas of
Earth receive the least direct sunlight?
Animation
• revolution
• Revolution
• Extra Practice
• Click on view
Climatic Zones
• The amount & angle of sunlight affects Climatic
Zones
• The latitude, distance north or south from the
equator, affects the temperatures that commonly
occur in that area.
• The further from the equator the less direct the suns
rays are
• These yearly patterns cause weather patterns to occur in
different regions of the earth that create climates.
World Climate Zones: Label in
notes
• Based on latitude, Earth’s surface can be
divided into a tropical zone, two temperate
zones, and two polar zones.
World Climate Zones
• Polar Zone: Areas within the Arctic and Antarctic Circles,
from 66.50 N and S latitude to the poles
• Characterized by a short, cool summer and long,
bitterly cold winter.
• Temperate Zone: between 23.50 and 66.50 north and
south latitudes
• warm to hot summers and cool winters
• Greatest temperature variation
• Tropic Zone: 23.50 degrees north latitude to 23.50 south
latitude
• Warm year round with little seasonal variation
Air Temperature by Month
Biomes are large geographical areas
with similar climates and ecosystems