Purpose:
    To collect data from an assigned city within each US region in order to explore the differences of the summer (September) and winter (January) jet stream patterns.  We will observe the position of the jet stream in each region and discover its connection to temperature and humidity.

Materials:

• Data collection sheets (Sept./ Jan.)
• Real time picture of jet stream
• Intellicast,Accuweather
• Weather.com (Select the day from the drop-down menu beneath the map; e.g. Monday US Jet Stream).
• Five Day Forecast
• Real time data of temperature, humidity, cloud cover, and wind direction (Type in the name of city for local forecast).
• 2 US maps per group (Sept. / Jan.)
• graph paper and/or spreadsheet software
• calculators
• rulers
• colored pencils
• transparency sheets
• markers
• overhead projector (optional)

Procedure: PART I September Data Collection

1. Separate the class into 5 groups with an assigned key city.
• Seattle, WA
• Phoenix, AZ
• Kansas City, MO
• New Orleans, LA
• New York, NY
2. Distribute a data collection sheet to each group.
3. Label the sheet with city's name, state, and latitude /longitude location.
4. Each group will collect and record the following data for a minimum of 2 weeks:  temperature, humidity, wind direction, and cloud cover. A daily picture of the jet stream (Intellicast; Weather.com(See above); Five Day Forecast) will also be printed out.
5. The groups will calculate the average temperature for their city and label it on their map.
6. Share temperature data with other groups.
7. Create a bar graph to display this information.
8. Repeat steps #5, #6, and #7 and do the same for humidity.
9. Observe the jet stream images collected.  On a transparency using a yellow marker, draw  what you think would be the average path of the jet stream for September.  Draw arrows showing the stream's directional flow.
10. All data should be collected and saved for January.

PART II-  January Data Collection

1. Groups now will REPEAT the steps in Part I for their city using January's information. (This time a green marker will be used to draw students' predicted jet stream.)
2. At this time a double bar graph can be created displaying the two seasonal temperature and humidity findings.

PART III - Conclusion / Data Analysis

1. Examine the temperature differences between September and January for each city. (Use either maps or bar graph). Which city had the greatest temperature difference? Was it north or south of the jet stream in September?  In January?
2. Which city had the least temperature difference? Was it north or south of the jet stream in September?  In January? Make a chart listing each city in order from the greatest to the least difference.
3. Look at the jet stream transparencies and maps.
4. Compare and contrast the paths of the jet stream for September and January.
5. What observations can be made about the jet stream? What has happened to its position and shape?  Which direction does it flow?
6. Discuss where the lower and higher temperatures are located in relationship to the jet stream.  On each transparency color the colder area blue and the warmer area red.
7. Are the higher humidity averages located above or below the jet stream?
8. Compare your prediction with the actual average summer and winter jet stream.

 Teacher note:  See Teacher Area > Background Information Page (#3)

PART IV - Culminating Activity

Purpose:
 To investigate what occurs when a cold air mass meets a warm air mass.

    Materials:

clear plastic sweater or shoe box

clothespin

large spoon

masking tape

styrofoam cup

ice cubes

food coloring

water

pencil

ruler

1. Pour warm tap water into clear plastic box to about 3 centimeters below the top. Add about 4 drops of red food coloring.
2. With a sharp pencil poke a hole 4 to 5 centimeters from the top of the cup. (Puncture from inside to outside and smooth away the rough edge.) Loosely seal hole with masking tape.
3.  Attach cup inside plastic box with clothespin. Top of cup should be even with the top of the box.
4. Fill the cup with ice cubes and tap water, add 4-5 drops of blue food coloring and stir.
5. When water settles, remove tape.
6. Draw a picture of the blue colored water as it moves out of the cup.

Discussion and Questions

1. Describe the path of the blue colored water.
2. Why do you think this happened?
3. What did the cold blue water represent?
4.  What did the warm red water represent?
5.  Based on your observations which do you think is heavier? Why?
6. What caused the cold water to react the way it did?  At this time it would be advantageous to introduce a general concept of density.
7.  Based on your observations, which do you think is more dense - cold or warm air? Why?
8. Which holds more water vapor (humidity) - a cold or a  warm air mass? Why?
9.  Based on your observations, compare the weather conditions below the jet stream and then above the jet stream.


Additional Links

Jet Stream:USA Today; Scientific America;  Fact Monster; Jet Stream Science