Activity
Part One – Sea Breezes and Land Breezes
1. Ask students how they think water affects the climate.
How do they think the sun and water interact to affect
climate?
2. Allow a few minutes for students to share responses
before beginning the experiment.
3. Divide the class into groups. {How man students per
group approximately?)
4. Have each group set up the following:
- one cup of dark colored sand,
- one
cup of light colored sand, and
- one cup of water.
5. Have students take the initial temperature of
the materials and place the materials equi-distant
from a heating lamp.
While they are working on the rest for the
lab, they should go back to check the temperature
every 5 minutes
approximately.
6. Once water and land have reached the
same temperature, have students remove
the heat
lamp and allow the materials
to cool, noting the temperature every 5 minutes.
How long does it take each material to
cool? Have students
graph
their findings.
7. Which one heats faster? [Land] Which holds
its’ heat
longer? [Water] How might that affect winds? Remember hot
air rises. [As the land heats, the hot air rises. Cool
air is denser and higher in pressure than warm air, and
high pressure moves toward lower pressure. This is an ocean
breeze. In the evening the air is cooler over the land
and a land breeze is created as the warm air above the
ocean rises and the cool, more dense land air rushes in
to take the place of the warm evening ocean air.]
Part TWO – Orographic Lifting & Rain
Shadows
1. When students enter the room, have the following
question written on the board: Consider a state
on the West coast
of the United States. Would you expect a lot
of rain there? Why or why not? Explain.
2. Allow students a few minutes to prepare
their answers. When they have finished writing,
have
them share their
responses with the class. [Hopefully you will
have some dissent. Some students will say there
should
be rain
since it is near an ocean and the winds come
from the West. Others
may say you can’t tell since we don’t know
the latitude.]
3. Tell students today they will be focusing
on the climate of Oregon. (Oregon is an ideal
state
to study, because
it is coastal, has large mountain ranges, and
is far enough North not to be affected by the
high-pressure
zone that
plagues states near the boundary between the
Hadley and
Ferrell Cells.)
4. Divide the class into groups and distribute
the map of Oregon and the Average Rainfall
Handout.
5. Have students plot the amount of rainfall
and devise a color-coded key that explains
patterns of rainfall
in Oregon, i.e. places that experience 0-50
cm of rain a year
are red, 50-100 cm of rain are yellow, etc.
6. What patterns do they notice? [More rain
West side of the state than East.] What is
that pattern?
7. What might cause the pattern to repeat itself
year after year? [The mountain range affects
rainfall on either
side
of the mountain.]
8. Tell students they have been studying rain
shadow effect. When warm moist air is blown
in and forced
up over a mountain
range, it cools adiabatically. Ask students
what they think adiabatic means? Why might
air cool
as it rises?
As a class,
come up with a definition of adiabatic cooling.
In fact, it cools so much the water molecules
condense and collide
until they become too heavy, turning to rain
or snow. Rain commonly develops this way, but
not
always.
9. Ask students to think about other rainy
places in the United States that are probably
not caused
by rain
shadow
effect. Remind students to think about the
prevailing winds as well as the proximity to
water. Tell
students while
proximity to water and mountains are ways a
location can get rain, there are others. The
next two
lessons will recover
cold and warm fronts to see their effects on
precipitation.
10. Given a fictional coastal city known for
its traffic congestion and large industrial
base located
in front
of the mountain range students should suggest
potential environmental
health issues that may arise as a result of
sea breezes and adiabatic cooling. How would
this
impact be different
from the similar sized city to the East of
the mountains?
|
Embedded
Assessment
Can
students plot rainfall correctly? Do they see patterns
in the data? Can students explain how landforms affect
climate? |
