Download Charting Air Pressure lesson

Charting Air Pressure
Fourth Grade
Summary
The earth is surrounded by a layer of air called the atmosphere. The air in the atmosphere has
weight, and it’s pressing down on the Earth all the time. The pressure is called air pressure.
Changes in air pressure are measured with a very sensitive instrument called a barometer.
Meteorologists pay close attention to air pressure. That’s because changes in air pressure
bring changes in weather. High air pressure signals clear skies and mild weather. Low air
pressure brings cloudy, rainy weather. What kind of air pressure do you think you’d find in
the center of a tornado or hurricane?
Build your own barometer to measure air pressure. Chart the data everyday at the same for a
week.
Key Concepts

Atmospheric pressure- the force exerted on you by the weight of tiny particles of air

Barometer- a scientific instrument used in meteorology to measure pressure in the
atmosphere
Objectives
Each student will create and use a barometer to chart real time data over a period of one
week.
Materials
 Small coffee can
 Plastic wrap
 Scissors
 2 straws
 Ruled index cards
 Clear tape
 Printed out weather chart
 Mathisifun.com
Procedure
1. Cover the top of the can with plastic wrap like the top of a drum. Use a rubber band to
hold the plastic wrap in place. The cover should be tight so air cannot escape the can.
2. Bend your flexible straw into the L-shape. Lay the longer part of the straw over the
plastic wrap so that the end of the straw in on the middle of the can, and the bent part is
hanging over the side of the can (the straw needs to be level with the top of the can).
3. Tape the straw to the middle of the plastic wrap.
4. Place the end of the straight straw lengthwise to the middle of the index card. Tape them
together. Then tape the other end of the straw towards the top of the side of the can.
5. Place your barometer on a table or flat surface. Make sure it’s inside and not near a
window, since it might be affected by temperature.
6. Carefully record the height of the straw on the index car. Mark it with a marker and pur
the number 1 on it.
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7. After 30 minutes, record the new location of the straw on the index card with the number
2.
8. Keep checking back to see if the straw has moved. Each time, mark the index card to
show the straw’s new location. We will be making measurements for one weeks.
9. The straw moves up and down as the air pressure changes.
If the straw’s tip moves up, that means the air pressure is increasing. The plastic
wrap depresses with higher pressure, this raising the straw’s tip. High pressure
usually means the weather will be clear and pleasant.
If the straw’s tip moves down, that means the air pressure is falling. Under low
pressure, the plastic wrap relaxes and would even rise because of the built-in
pressure inside the can, thus lowering the straw’s tip. Low pressure usually means
that cloudy or rainy weather is on the way.
10. Determine whether the air pressure is rising or falling. Then record the data everyday at
11AM for a week and record your findings in your science journal.
11. Students will use their science journal to create graph on mathisfun.com. Then as a class
we will then compare and contrast data.
Assessment


Performance—the students will chart their data from their barometer
Product- The students will char their data on the mathisfun.com website.
Additional Resources
http://www.amnh.org/ology/features/stufftodo_earth/weather_barometer.php
http://www.mathsisfun.com/data/data-graph.php
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Got time?
If you have time before your presentation, it would be helpful to provide

Relevant content standards—National Science Education Standards:
http://www.nap.edu/readingroom/books/nses/html/6a.html

Science skills (using the Essential Science Skills grid on the EARTH Web site:
http://www.mbari.org/earth/skills.htm

Ocean Literacy Standards:
http://www.coexploration.org/oceanliteracy/documents/OceanLitChart.pdf

Key concepts, according to the AAAS benchmarks, which provide a framework for K-12
expectations: http://www.project2061.org/publications/bsl/online/bolintro.htm
Chapter 4. B. The Earth
The weather is always changing and can be described by measurable quantities such as
temperature, wind direction and speed, and precipitation. Large masses of air with certain
properties move across the surface of the earth. The movement and interaction of these air
masses is used to forecast the weather. 4B/E5** (NSES)
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