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Oceans and Climate
ACTIVITY OVERVIEW
L
ROLE P
Students learn more about how oceans affect climate. They participate in a role-play
that discusses the history of the identification of the Gulf Stream and how modern
technology is used to gather ocean data. An Intra-act literacy strategy helps guide
discussion about the ideas presented in the role play.
KEY CONCEPTS AND PROCESS SKILLS
(with correlation to NSE 5–8 Content Standards)
1.
Meteorologists, atmospheric scientists, climatologists, and hydrologists study different aspects of the earth’s weather and atmosphere. Society relies on the information provided by such scientists. (History: 1)
2.
Tracing the history of science demonstrates how individuals contributed to the
development of modern scientific ideas, and reveals important interactions
between science and society. (History: 3)
3.
Factors that influence climate include the heating and cooling of land and water,
ocean currents, latitude, elevation, landforms, and global wind currents. (EarthSci: 1)
4.
Oceans have a major effect on climate, because water in the oceans holds a large
amount of heat. (EarthSci: 1)
KEY VOCABULARY
climatologist
Gulf Stream
hydrologist
ocean current
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Activity 57 • Oceans and Climate
MATERIALS AND ADVANCE PREPARATION
For each student
1
Student Sheet 57.1, “Intra-act Discussion: Oceans and Climate”
*Not supplied in kit
TEACHING SUMMARY
Getting Started
1.
Introduce the role-play.
Doing the Activity
2.
Students participate in a role-play about ocean currents and climate.
Follow-Up
3.
(LITERACY) Students discuss the role-play using a literacy strategy known as Intraact.if this works)
BACKGROUND INFORMATION
Benjamin Franklin
Benjamin Franklin was born in 1706 in Massachusetts, which at the time was an English colony. Even though his formal schooling was minimal, he became one of the
most influential figures of his time in fields as diverse as science, literature, technology, government, business, and politics. He ran one of the largest printing companies
in Philadelphia, and gained fame as editor and publisher of the Pennsylvania Gazette
newspaper and Poor Richard’s Almanack, an annual publication that had articles
about things such as the year’s planetary events, tides, and weather and was peppered with such adages as “a penny saved is twopence clear” (a penny saved is a
penny earned).
Franklin’s curiosity about the natural world was limitless, and he investigated a wide
range of phenomena from electricity to physiology. He was also fastidious about documenting his observations. In an era where the average person did not travel far from
home, Franklin crossed the Atlantic eight times and visited 10 different countries. On
his voyages to Europe, Franklin recorded both air and water temperatures of the
Atlantic Ocean. His data was used to produce the first map of the Gulf Stream in the
Atlantic Ocean.
Franklin invented many tools that made daily life easier and safer. He invented the
lightening rod, bifocal glasses, and an efficient stove (the Franklin stove) for heating
houses.
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Oceans and Climate • Activity 57
Franklin also participated in writing the Declaration of Independence, the peace
treaty with France (1778), the peace treaty with Great Britain (1783), and the Constitution of the United States of America (1787). Because of this, Franklin is known as on
one of America’s founding fathers. He died in Philadelphia in 1790.
Ocean Currents and Climate
There are two types of ocean currents: surface and deepwater. Surface currents, which
extend only to the first few hundred meters of the ocean, are primarily driven by wind
and earth’s rotation (the Coriolis effect), resulting in circular patterns known as gyres.
In the Northern Hemisphere, the large, mid-latitude currents move clockwise while in
the Southern Hemisphere they move counterclockwise. Deepwater ocean currents are
also driven by differences in water temperature, salinity, and density. This movement
of deepwater and surface water is known as thermohaline circulation. The interaction
of surface and deepwater currents results in large-scale movement of ocean water
around the globe sometimes called the “ocean conveyer belt.” The ocean conveyer
belt results in the movement of water of different temperatures and salinity around
the globe.
Earth’s oceans are heated by radiant energy from the sun and act as a heat reservoir,
storing the absorbed energy. Ocean currents carry the stored energy around the globe
by ocean currents. Climates are affected due to the interaction of this water, air, and
land. A warm ocean surface current such as the Gulf Stream produces warm, moist air
masses that can move into regions where they warm the climate. (Note that the portion of the Gulf Stream that crosses the Atlantic Ocean and nears the coast of the
United Kingdom is sometimes referred to as the “North Atlantic Drift.”)
Ocean Technology
In the past 50 years, satellite technology has expanded data-collection capabilities so
that ocean-temperature measurements can be collected more rapidly than before.
This data provides a clearer picture of monthly, seasonal, and yearly ocean changes,
including temperature, sea-surface height, and current flow. In 1978, NASA launched
the Scientists and Engineers Statistical Data System (SESTAT) satellite, which in only
105 days of operation collected more information about earth’s oceans than in the
previous 100 years of data collection from ships, buoys, and other drifting instruments. Currently NASA has several ocean-mapping missions collecting data from an
array of bouys positioned around the globe, an effort that has made nautical maps
far more accurate and greatly expanded knowledge of ocean currents.
REFERENCES
Bryden, H. L., Longworth, H. R., and Cunningham, S. A. (December 1, 2005). Slowing
of the Atlantic meridional overturning circulation at 25 degrees North. Nature, 438:
655-657.
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Activity 57 • Oceans and Climate
TEACHING SUGGESTIONS
GETTING STARTED
1.
Introduce the role-play.
Explain to students that they will read aloud a roleplay in which all of the characters except one, Benjamin Franklin, are fictional. Ask, What do you
know about Benjamin Franklin? Students may or
may not be familiar with this historical figure, but
they all will gain more from the role-play with some
additional background information, which is provided in the Background Information section of this
Teacher’s Guide.
DOING THE ACTIVIT Y
2.
Students participate in a role-play about
ocean currents and climate.
Have students read the role-play aloud, either in
small groups of four or as a class with an audience.
Another option is to have students first read the
role-play aloud in groups of four and then watch
one (or more) groups perform it for the class. Many
students are likely to understand and remember
more ideas with a second reading. Often, students
realize that they missed key ideas the first time
through.
FOLLOW-UP
3.
(LITERACY) Students discuss the role play
using a literacy strategy known as Intra-act.
Intra-act is a literacy strategy intended to facilitate
discussion and help students synthesize concepts. In
this strategy, students evaluate statements related
to the reading and decide if they agree or disagree
with each one. Intra-act requires students to express
an opinion about each statement. Their opinions
should be supported by evidence or may sometimes
rely on values related to evidence. Intra-act helps
students think about what they know about the
topic, and gives them a stake in participating in the
discussion. Having to predict what others will say
gives students an incentive to listen to each other
and weigh differing perspectives. For more information on Intra-act, see the Literacy section of
Teacher Resources II: Diverse Learners.
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Hand out Student Sheet 57.1, “Intra-act Discussion:
Oceans and Climate.” Have students evaluate each
statement independently and record whether they
agree or disagree by circling “Agree” or “Disagree”
next to each statement in the column titled “Me.”
Students should enter the names of the other group
members at the tops of the other columns and predict the opinions of their group members.
In the next phase of this strategy, students score
their student sheets as group members share their
opinions. Each group member takes a turn revealing how he or she responded to the four statements
and why, while the other group members compare
their predictions to the actual response. On the student sheet, students mark whether their prediction
was correct (+) or incorrect (—) and count up how
many of their 12 predictions were correct. The goal
is to encourage careful listening and to have students share their opinions in a cooperative manner.
As they do more Intra-act activities, students should
get better at correctly predicting the opinions of
members of their group. The scores they add up are
not grades; from one activity to another they provide a measurement of students’ progress. Sample
responses to the statements are shown below.
Sample Responses to Student Sheet 57.1,
“Intra-act Discussion: Oceans and Climate”
1. New technology is more helpful today than it was in
the 1700s.
Some students may agree, stating that technology today is more advanced and therefore more
helpful than technology of the 1700s. Others
may disagree and say that the technology developed in the 1700s was more helpful at the time
because it was new. A third position that students may take is that it is impossible to evaluate, because technology from the 1700s was
helpful then, just as today’s technology is helpful now, but perhaps in different ways.
2. The greatest effect on climate is from ocean currents.
Some students may agree because the focus of
the role-play was on the interaction of oceans
and climate. Other students may realize that
Oceans and Climate • Activity 57
informally assess students understanding of the
relationship between oceans and climate. There
will be an additional opportunity to assess students’ understanding of this concept in Activity
58, Analysis Question 2.
there are many important factors contributing
to climate, including energy from the sun and its
heat stored in the oceans. Discussion of this
statement is a way to review with students the
importance of these other factors and to set the
stage for the next activity, in which students
read about other factors influencing climates.
3. Scientists have evidence that the Gulf Stream is slowing down.
Students who disagree with this statement may
say that there is no evidence to show that the
Gulf Stream is slowing down and that the study
referred to in the role play describes the slowing
down of a cold deepwater current that is part of
the global circulation pattern that includes the
Gulf Stream, but does not provide data about
the Gulf Stream itself. They may say that more
data needs to be collected. Students who agree
with the statement may say that data collected
over a 50-year period provides evidence that the
pattern of ocean currents, including the Gulf
Stream, is slowing down.
4. All scientific ideas are discovered by experimentation.
Many students may disagree and point out that
an understanding of the Gulf Stream and ocean
currents was developed through observation
and data collection, not experimentation. A few
students may agree, saying that a scientific idea
is valid only if and when it has been reproduced
through experimentation. Depending on students’ perspectives, you may want to use this
statement to have a short discussion on the
nature of science and scientific evidence.
After students have completed their group discussions, discuss each of the four statements as a
class. Be sure to review Statement 3, which helps
assess students’ understanding of the ideas presented in the role play as well as the nature and
scope of the scientific evidence presented in it.
Use the Analysis Questions to summarize some
of the key ideas presented in the role play.
Analysis Question 3 serves as a QuickCheck to
SUGGESTED ANSWERS TO QUESTIONS
1.
What kinds of data do you think scientists
need to collect to determine if the climate
of Ireland is changing?
Encourage students to think about different
types of data that could be used to investigate
this issue. Scientists can continue to collect additional data about the cold deepwater current,
including water temperature and current speed,
to determine if the current is continuing to slow
down and at what rate. They could collect data
on the Gulf Stream itself to determine if it
appears to be slowing down. Or they might analyze 50–100 years worth of mean air temperatures in Ireland to determine if there is any
cooling of the climate. They could also gather
historical geological data about the Gulf Stream
and Ireland’s climate.
2. How do the techniques used to map ocean currents
today differ from those used in the late 1700s?
Today, ocean current data is collected using
instruments attached to buoys and satellites.
The buoys are placed in oceans around the
world by boat or plane. Instruments on the
buoys gather temperature, speed, and salinity
data which are then uploaded to satellites. Scientists can download the data for analysis. In
the late 1700s, information had to be read from
instruments that were dangled from boats. This
process limited the amount and locations of
data that could be collected. Modern techniques
gather data more frequently and from more
locations. The data can be made immediately
available to scientists around the world.
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Activity 57 • Oceans and Climate
3.
✓
What is the relationship between oceans
and climate?
A sample response is described below. When
evaluating students’ responses, check to see if
they have identified the following three ideas: 1)
the sun heats earth’s oceans; 2) oceans store
large amounts of heat energy; 3) ocean water
moves in currents that transfer some of this
energy, affecting climates.
The sun warms earth’s oceans. Oceans store
large amounts of heat energy and move that
energy around earth in large currents. These
currents transfer heat from one part of the world
to another, affecting climates. The Gulf Stream is
one example of a current that causes the climate
of one part of the world to be different than it
would otherwise be.
4. Look at the map below (in the Student Book).
Describe the likely effect of the California current on
the climate of California.
Since the California Current is a cold current, it
is likely to create lower temperatures along the
California coast. This means that the climate of
coastal California would be cooler than in other
places of the same latitude (and altitude) that
are not affected by such a current.
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Issues and Earth Science • Student Sheet 57.1
Agree/Disagree
Agree/Disagree
Agree/Disagree
Agree/Disagree
Me
+ : Predictions were correct.
– : Predictions were incorrect.
experimentation.
are discovered by
4. All scientific ideas
down.
Stream is slowing
dence that the Gulf
3. Scientists have evi-
ocean currents.
on climate is from
2. The greatest effect
1700s.
than it was in the
more helpful today
1. New technology is
©2006 The Regents of the University of California
+ or –
Agree/Disagree
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Agree/Disagree
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Agree/Disagree
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Agree/Disagree
Number of correct predictions:
+ or –
Agree/Disagree
+ or –
Agree/Disagree
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Agree/Disagree
+ or –
Agree/Disagree
Names
__________ /12
+ or –
Agree/Disagree
+ or –
Agree/Disagree
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Agree/Disagree
+ or –
Agree/Disagree
Name
Date
Intra-act Discussion: Oceans and Climate
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