The TEKS
Know that climatic interactions exist among
Earth, ocean, and weather systems.
• 8.10 (A) recognize that the Sun provides the
energy that drives convection within the
atmosphere and oceans, producing winds and
ocean currents;
ENGAGE
Ocean Currents
What causes the movement of air and
water throughout the Earth?
EXPLORE
1) Fill your container with tap water.
2) Carefully place an ice cube at each end of the
baking dish.
3) Observe what happens.
4) Record your observation on your lab sheet.
EXPLAIN
1) What did the ice cubes represent?
2) Why were they placed at the far end of your
container?
3) What did you observe?
TIME FOR A FOLDABLE
CONVECTION
Transfer of heat by the movement of
warmer, less dense (air or liquid) rising
and cooler, denser (air or liquid) sinking
CONVECTION
CONVECTION
CONVECTION
Moves air in the atmosphere!
Moving Air = Winds
Convection in the atmosphere
is the main cause of the wind.
Where does the Energy for
Convection come from on
Earth?
THE SUN!!!
CONVECTION
CONVECTION
causes deep ocean currents!
CONVECTION
Wind over the
shore changes
direction
because of
EARTH’S
UNEVEN
WARMING &
COOLING!
Hot Air is Less Dense!
Atmospheric Movement
MOSTLY CAUSED BY:
- Temperature differences
- Pressure differences
- Coriolis Effect (due to Earth’s rotation)
The Coriolis effect
• The Coriolis effect
– Is a result of Earth’s rotation
– Causes moving objects to follow curved paths:
• In Northern Hemisphere, curvature is to right
• In Southern Hemisphere, curvature is to left
– Changes with latitude:
• No Coriolis effect at Equator
• Maximum Coriolis effect at poles
The Coriolis effect on Earth
• As Earth rotates,
different latitudes
travel at different
speeds
• The change in speed
with latitude causes
the Coriolis effect
Figure 6-9a
Role of the Ocean
• Slowly absorbs and slowly releases heat
energy helping keep Earth’s temperatures
relatively stable
• Oceans heat or cool the air above them and
transport heat around the globe in currents.
• Hurricanes form over warm ocean water,
drawing their energy from the water’s heat.
Ocean Currents
Currents
•
large scale water movements
– occur everywhere in ocean
– both surface and deep
•
2 main types: surface currents (10%) and deep sea currents (90%)
– surface currents are primarily wind driven
– deep currents are density driven
– other forces affecting currents
Coriolis effect
friction
gravity
thermal expansion
geologic shape of ocean basin
ELABORATE
1) Use the pipette to
carefully put several drops
of red hot water at the
bottom of the container.
2) Remove the pipette and
watch what happens to the
red water.
Why is it important to study
ocean currents? How do
plants, animals, and humans
use ocean currents?
Ten Bizarre Things That Washed Up On Shore
EVALUATION
1) Convection currents, which affect
weather and climate, are created by...
A. slow, constant tectonic movement.
B. erosion of ocean beaches.
C. mining of the seafloor.
D. the uneven heating of the Earth.
1. Convection currents, which affect
weather and climate, are created by...
Answer:
D. the uneven heating of the Earth.
2) Water is cooler near the poles and warmer near
the equator. Movement of cooler and warmer
water from these regions moderates the global
climate.
Which of the following describes the movement
of water between the poles and the equator?
A. tides
B. ocean currents
C. evaporation
D. gravity
2. Water is cooler near the poles and
warmer near the equator. Movement
of cooler and warmer water from
these regions moderates the global
climate. Which of the following
describes the movement of water
between the poles and the equator?
Answer:
B. ocean currents
3. Surface ocean currents are primarily
formed by _______.
A. winds
B. tides
C. aquatic organisms
D. underwater volcanoes
3. Surface ocean currents are primarily
formed by _______.
A. wind
4. Which of the following is NOT true:
A. colder, denser water at the poles
sinks below warmer water.
B. colder, denser water at the poles
rises above warmer water.
C. warmer, less dense water at the
equator rises above colder water.
D. saltier, denser water sinks below
fresh, less dense water.
4. Which of the following is NOT true:
B. colder, denser water at the poles
rises above warmer water.
5. What does the Coriolis Effect explain?
A. why it is hard to catch baseballs.
B. why surface winds or currents
turn in one direction or another.
C. how volcanoes are formed.
D. why salt water is denser than
fresh water.
5. What does the Coriolis Effect
explain?
B. why surface winds or currents
turn in one direction or another.
Lost at Sea
Duckie Progress
•January 1992 - shipwrecked in the Pacific Ocean, off the coast of
China
•November 1992 - half had drifted north to the Bering Sea and
Alaska; the other half went south to Indonesia and Australia
•1995 to 2000 - spent five years in the Arctic ice floes, slowly
working their way through the glaciers
•2001 - the duckies bobbed over the place where the Titanic had
sunk
•2003 - they were predicted to begin washing up onshore in New
England, but only one was spotted in Maine
•2007 - a couple duckies and frogs were found on the beaches of
Scotland and southwest England.