Download October 30th Presentation

October 30th, 2014
You have until 9:15 to
complete the warm up
Today’s Objectives:!
Students will set up an investigation that demonstrates what
happens to two air masses when they meet.
!
Students will analyze the movement of two air masses with
different temperature and humidity conditions.
Warm Up
•
What two factors do we look at in air masses?
•
Temperature and Moisture!
•
What is a boundary between two colliding air masses called?
•
Air Front!
•
What kind of pressure does warm air have? Cold Air?
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Warm air has low pressure, Cold Air has high pressure!
•
What causes wind? (hint concept map)
•
A difference in pressures.
A cold air mass meets and displaces a warm air
mass. Because the moving cold air is more dense,
it moves under the less-dense warm air, pushing it
up.!
Cold fronts can move fast, producing
thunderstorms, heavy rain, or snow. Cooler
weather usually follows a cold air front because
the warm air is pushed away from the Earth’s
surface.
A warm air mass meets and over-rides a
cold air mass. The warm, less-dense air
moves over the cold, denser air. The
warm air gradually replaces the cold air.!
Warm fronts generally bring drizzly
precipitation. After the front passes,
weather conditions are clear and warm!
!
A cold air mass meets a warm air
mass and little horizontal occurs. !
The weather is associated with a
stationary front is similar to that
produced by a warm front.!
!
A faster-moving cold air mass overtakes
a slower-moving warm air mass and
forces the warm air up. The cold air mass
then continues advancing until it meets a
cold air mass that is warmer.The cold air
mass then forces this air mass to rise. !
An occluded front has cool temperatures
and large amounts of precipitation
Analysis Answers
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1. A mT air mass would most likely contain what type of
temperature and moisture characteristics?
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A mT (maritime Tropical) air mass would contain warm wet air.!
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2. What two characteristics are used to describe an air mass?
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Temperature and Moisture are the two characteristics to
describe an air mass.!
•
3. Which symbol would be used to identify an air mass originating
in central Canada?
•
An air mass originating over central Canada would be cP
(Continental Polar)
Analysis Answers
•
4.
How does density play a part in determining how unlike air
masses react?
•
When two unlike air masses(hot and cold) meet the cold air is
denser which moves down, the warm air is less-dense and
moves upward.!
•
5.With respect to a cold front, where does precipitation occur?
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Precipitation occurs at the beginning and along the Cold Front!
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6. With respect to a warm front, where does precipitation occur?
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If any Precipitation occurs, it is at the beginning of the Warm
Front
Conclusion
Compare the following conditions on either side of the cold front.
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Temperature!
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Before the front the temperature is warm, after the front the
temperature is cold.!
•
Pressure:!
•
Before the front the Pressure is low, after the front the pressure is
High. !
•
Rainfall:!
•
Before the front there is precipitation, After the front there is little to no
precipitation
Introduction
What causes wind to blow? Mostly, it has to do with the uneven heating of the
Earth. Breezes occur because land and water heat and cool at different rates.
This means this creates an unequal balance of air pressure above land and
water.!
!
! When the sun’s energy heats the earth, the temperature of the air above the
Earth’s Surface changes. Air, warmed by the surface below it, starts to rise, and
cool air moves in to take its place. This circulation of air causes changes in
weather, including the formation of winds.!
!
! In this lesson, you will connect two Convection Tubes used previously in other
labs. We observe what happens when masses of air with the same temperature
and humidity meet? What happens when air masses of different temperature and
humidity meet?!
!
Problem: In the space below write down what we are investigating in today’s lab.!
!
• We are investigating what happens when masses of same and different
temperature and moisture meet.
Materials
2 Convection Tubes!
1 120 mL plastic container of hot water!
1 120 mL plastic container of crushed ice!
1 piece of plastic tubing!
2 candles!
A lighter!
1 punk stick!
1 flashlight!
1 small aluminum pan!
Procedures
•
1. Gather Materials!
•
2. Write your predictions for each of the different atmosphere
conditions.!
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3. Place a cup of warm water under each end of the convection tubes.!
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4. Light a punk stick and put the smoke in top of one end of the
convection tubes,!
•
5. Use the flashlight to observe how the air moves. Write down your
observations in the data table.!
•
6. You will have 3 minutes for each atmospheric condition, spend
about a minute and a half making observations and the other minute
and a half writing your observations down.!
•
7. Repeat steps 3 - 6, using the different atmospheric conditions.
Predictions
Atmosphere Conditions
Warm water and Warm
water
Cold Air!
(Ice) and Cold Air (Ice)
Cold air (Ice) and Warm
Water
Hot air (Candle) and Cold
air (Ice)
Hot air (candle) and Warm
Water
Prediction (How will the
air move in the tubes?)
Things to remember
!
1. You have three minutes for each atmospheric condition. !
!
2. Place the punk stick at the top of the colder end. If the temperatures
are the same it does not matter which tube.!
!
3. Only use the flashlight when told to do so. Clubs will be Light Master!
!
4. Observations should include speed, direction, and concentration of
smoke.!
!
5. Spades will be materials master!
!
6. Leave Candles burning between atmospheric conditions scenarios.!
Example
Warm Water and Warm Water
!
!
!
!
•
Observations: ( How did the air move in the tubes?
Place the punk over the colder tube and note any
differences in movement.)
Cold Air
(Ice) and Cold Air (Ice)
!
!
!
!
•
Observations: ( How did the air move in the tubes? Place the
punk over the colder tube and note any differences in
movement.)
Cold Air (Ice) and Warm Water
!
!
!
!
•
Observations: ( How did the air move in the tubes? Place
the punk over the colder tube and note any differences in
movement.)
Hot air (Candle) and Cold Air (Ice)
!
!
!
!
•
Observations: ( How did the air move in the tubes? Place
the punk over the colder tube and note any differences in
movement.)
Hot Air (Candle) and Warm Water
!
!
!
!
•
Observations: ( How did the air move in the tubes?
Place the punk over the colder tube and note any
differences in movement.)
Analysis
•
What did you observe when both tubes contained air with the same temperature
and humidity conditions? Why do you think this happened? (3 points)
!
•
What did you observe when the tubes contained air with different temperature and
humidity? Why do you think this happened? (3 points)
!
•
On the basis of your results from the lesson, under what conditions do you think
winds and rotating storms might form? (2 points)
!
•
Describe what you observed when the atmospheric conditions were cold meets
hot. Use the following terms; high pressure, low pressure, high density, low density,
rise, and sink. (6 points)
Essay
•
After examining the following diagrams explain why
there is uneven heating of the earth surfaces. Then
describe how the uneven heating of the earth
surfaces is responsible for sea breezes and land
breezes. Think back to how soil and water heat and
cool differently.