Transcript Seasons - Manhasset Public Schools

1) Moon and Tides
The moons gravitational pull
causes the tides
1) Moon and Tides
• One tide cycle (from high to high
tide) takes approximately 12 hours
2) Earth’s rotation
•Earth’s rotation gives us the
daily cycle of daylight and
day and ______.
night
darkness, or ____
•The side facing the Sun will
have daylight
_______, the side
facing away from the Sun will
have ________.
darkness
a) Why do we have night and
The side of Earth that faces sun is day
day?
•
• The side that faces away is night
Hello Down There!
a)What Evidence do we have for
rotation?
1. Coriolis Effect
2. Focalt’s Pendulum
1. The Coriolis Effect
• Wind and Ocean Currents are deflected because the Earth rotates
• Deflects to the right in Northern Hemisphere
• Deflects to the left in Southern Hemisphere
2. The Foucault Pendulum
• A swinging pendulum that moves back and forth
• Over a 24 hour period, the pendulum appears to move in
a circle
•Earth rotates from West to East
when viewed from the North
Pole. This makes the Sun
appear to rise in the East
____ and set
in the West
_____. This motion of the
Sun from sunrise to sunset is
called _________
apparent motion because
it is not really the Sun that is
moving.
LET US REVIEW
1. The tides are caused by the
gravitational pull of the moon
2. Day and night are caused by Earth’s
ROTATION.
3. Earth rotates on its axis from WEST
to EAST.
4. The sun appears to rise in the EAST
and set in the WEST
Do Now: Hand in your GIZMO.
Explain the difference between neap
and spring tides
Homework: Vitamin D
Seasons
New Vocabulary
Apparent Motion: The movement a
celestial object seems to make.
Horizon: where the land meets the sky.
Seasons: Different times of the year
where we experience different
temperatures. Caused by the tilt and
orbit of Earth
a) Earth’s axis
23.5
•Our axis is tilted ____ degrees.
•Our North Pole always points
towards Polaris (the North
Star).
Tilt of the axis always stays the same,
pointing toward Polaris
b.What causes the seasons?
There are two main
reasons for the seasons.
Distance from the Sun is
NOT one of the reasons!
Winter Spring Summer Fall
TWO REASONS FOR SEASONS
1. The tilt of Earth’s axis.
2. Earth’s revolution around
the Sun.
These two reasons cause
the rays of the Sun to hit
Earth at different angles.
PROVE IT:
How do we know the angle of the
Suns rays makes a difference with
respect to what season it is?
Hold a small flashlight over the boxes
below. In box A, point the flashlight at
the box at a 90 degree angle. In box B,
point the flashlight at a 45 degree angle.
Box A - 90º
Box B - 45º
1. If you could feel the heat from the
flashlight, would it be hotter in box A or
box B? ________
Box A
2. Why would that box feel hotter?
__________________________________
The
light is shining directly on it
3. If each box represented either summer or
winter, which box would be summer, and
which box would be winter? Box _____
A
would be summer and box _____
B would be
winter.
4. Why? Because
_____________________________
it is hotter in the summer.
Angle of the Suns rays
The energy that hits the Earth by the Sun changes over
of the year.
The angle the Sun is above the horizon determines how
much heat and light strike each square meter of
ground.
http://inkido.indiana.edu/a100/celestialsphere5.html
C. How does the tilt affect the angle?
NH
 Northern Hemisphere is tilted towards
Summer Receives
the sun in __________.
DIRECT rays of sunlight
(Look at how North Pole is pointed)
NH
 Indirect rays are hitting the
Northern Hemisphere. This means it is
Winter (season) in the Northern
__________
Hemisphere when the North Pole is
tilted away from the Sun.
D. What does Earth’s
revolution around the Sun
do?
Earths revolution around the
Sun makes it possible for the
North Pole to be either tilted
towards or away from the
Sun.
Seasons in the Northern Hemisphere
Seasons Animation
E. What about spring and fall?
The Earth is not tilted toward or
away from the Sun in spring & fall.
Earth is heated evenly in the spring
and the fall. That is why they are
called equinoxes.
EQUINOX:
Day (12 hours) = Night ( 12 hrs)
Everywhere on Earth has equal day/night
Seasons ALWAYS go from:
winter
spring
summer ______
fall
to___________to
___________to _________
Aim # 18: How do the seasons
differ?
Do Now: Explain how the tilt of
the Earth causes the seasons?
Homework: textbook pg 212-213
Q#2, 3, 8, 10, 12, 19, 24
1. Why does the amount of
daylight change with the
seasons?
The length of light during the day and
the length of darkness at night
depends upon Earth’s position in It’s
Orbit
Orsa,
Sweden
June 22
11: 59 PM
For Example:
A
B
Summer (in Northern Hem),
We are tilted towards so longer days
EX:
16 hours daylight, 8 hours night for
st
summer solstice (June 21 )
2. First Day of Each Season
The first day of each season marks a key
point in Earth’s orbit around the sun
The South Pole receives 24 hours of daylight on
the day shown because it is tilted toward the
Sun and is located on the SIDE OF THE
EARTH THAT RECEIVES SUNLIGHT FOR
24 HOURS. WHAT DAY IS THIS
DATE
NEW YORK
December 21st
Winter Solstice
First day of Winter
March 21st
Vernal Equinox
First day of Spring
June 21st
Summer Solstice
First day of Summer
September 21st
Autumnal Equinox
First day of Fall
HOURS
Tilt of Earth Useful Facts
OF
SUNLIGHT
FUN FACTS
The equator ALWAYS has 12 hours of
daylight … every day of the year
During the winter Solstice, from the Arctic
circle (66.5 deg N) to the North Pole have
24 hours of DARKNESS!
During the summer Solstice from the Arctic
circle to the North Pole have 24 hours of
LIGHT!
Lesson Review
1. TRUE or FALSE
When the North Pole is tilted toward the Sun, the
Northern Hemisphere has LESS daylight hours.
2. TRUE or FALSE
During winter, the combination of fewer daylight
hours and less direct rays of the Sun causes
LOWER temperatures.
3. TRUE or FALSE
When the Northern hemisphere is tilted toward the
Sun, it has SUMMER.
4. TRUE or FALSE
The SEASONS are caused in part by the tilt of
Earths axis.
5. TRUE or FALSE
During WINTER, the Suns rays are less direct.
6. TRUE or FALSE
Direct rays produce LESS heat than indirect rays..
7. TRUE or FALSE
The seasons in the Northern Hemisphere and the
Southern Hemisphere are the SAME.
Important Concepts to
Remember!
1. a. The Winter season begins in the Northern
Hemisphere on December 21st.
b. The Summer season begins in the Southern
Hemisphere on December 21st.
2. a. The Spring season begins in the Northern
Hemisphere on March 21st.
b. The Fall season begins in the Southern
Hemisphere on March 21st.
3. The Northern Hemisphere receives direct rays from
the Sun on June 21st.
4. The Northern Hemisphere has more daylight hours
on June 21st
INFER
Think about an activity you do
here in the summer. How
does the change from
summer to winter affect your
life here in New York
compared to how it would
affect your life if you lived in
Florida?