WIND

California State Science Content Standards - Grade 5

Standard: 4a.
Students know uneven heating of Earth causes air movements (convection currents).

BACKGROUND INFORMATION
A sea breeze is a local wind that occurs in a region near the ocean or a large lake. During the day, temperatures in the inland areas are warmer than the temperatures along the coast. The warm air rises and the cooler coastal air moves in to replace it. Since the air is moving from the sea toward the land, this type of breeze is called a sea breeze. At night, the air inland cools down, and sometimes it cools down so much that it is cooler than the coastal air. If that is the case, the warm air above the water rises and the cooler air from the inland area moves in to replace it. Since the air is moving from the land toward the water, this type of breeze is called a land breeze.


DATA
For the most part, the data used in this activity is the real data for a particular day. The data for the given day was selected as a "classic illustration" of the weather topic at hand. Even so, "subtle and not so subtle variations in this dataset highlight the natural complexity of weather." Let us know if you would like more information about how to bridge gaps between the idealized vs. "messy" real world. We plan to add access to current data in the next phase, but current data will bring surprises "like a box of chocolates."


OVERVIEW OF ACTIVITY (50 minutes)
Students collect air temperature data at different times of the day from an inland location and from an ocean buoy. They observe how the temperature differences affect wind patterns throughout the day.


KEY CONCEPT
When air is warmed, it becomes less dense than the surrounding air and it rises, causing an updraft. When air is cooled, it becomes denser than the surrounding air and it sinks, causing a downdraft. When the warm air rises, the cooler surrounding air moves in to replace the air that has risen.


TEACHING & LEARNING TOOLS
Compass directions
Online game to help students learn their general compass directions, with link to static diagrams that can be printed as overheads.

Wind directions
Online game to help students learn how wind directions are designated, with link to static diagrams that can be printed as overheads.


TEACHING TIPS
  1. Make sure that students know that wind direction is expressed as the direction FROM which the wind is blowing.

  2. Remind students that they can move the compass onto the map to help them determine the wind direction.

  3. Remind students to print their data table and the conclusion questions because they will turn them in at the end of the lesson.

  4. After they have gone through the Learn More page and the class discussion, remind students to make any necessary changes to their answers for the conclusion questions before turning them in.



PROCEDURE
  1. Ask the students if they have ever noticed a cool breeze when they are at the beach. Do they remember which direction it was blowing? Why do they think there was a breeze at the beach? (5 minutes)

  2. Tell the students that they will use the Weather and Water Web site to explore wind patterns in southern California.

  3. Direct students (individually or in their investigation teams) to follow the directions on the Web site to complete the activity and answer the conclusion questions.

  4. Website Activity (35 minutes)

    STEP 1:  Students collect temperature and wind data at four times during the day from an inland location.

    STEP 2:  Students collect temperature and wind data at four times during the day from an ocean buoy.

    STEP 3:  Students observe the change in wind patterns over the course of the day. Students print their data table to help them answer the conclusion questions.

    STEP 4:  Students answer and print conclusion questions based on their data.

    STEP 5:  Students view a conclusion page that explains how temperature differences affect wind patterns. They learn that sea breezes are created when warmer air inland rises and cooler air from the coast moves in to take its place. They make any necessary changes to their answers for the conclusion questions before turning them in to the teacher.


  5. Review the conclusion questions and the Learn More page as a class. Ask students to record any additional information or questions generated by the discussion in their Science Notebooks. Collect the conclusion questions and data table from each team so you can review them. (10 minutes)

Review Questions:
  • Describe the general compass direction from which the winds were blowing at each of these times of the day: 2 AM, 8 AM, 2 PM, and 8 PM.

    Answers will vary depending on the studentís data. Look at the data to confirm that the student recorded the correct compass directions. Generally, local winds blow from an area with a lower temperature to an area with a higher temperature. During the day, the warmer inland air rises and the cooler air from the coast moves in to take its place.


  • A sea breeze is a wind that blows from the ocean to the land. At what time of day were sea breezes strongest?

    Answers will vary depending on the studentís data. Look at the data to confirm that the student recorded the correct time. Generally, the sea breezes will be the strongest when the difference in temperature is the greatest. This will probably be mid-day.


  • Were the sea breezes the strongest when the temperature difference between land and sea was the biggest or the smallest?

    The sea breezes should be the strongest when the temperature difference between land and sea is the biggest.


  • A land breeze occurs when wind blows from the land to the ocean. What would the temperature conditions have to be in order for this to occur? Was there a time during your day of data when a land breeze occurred? If yes, what time?

    The temperature over the ocean would have to be higher than the temperature over the land for a land breeze to occur. These conditions would most likely occur at night.


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    ©2005 by the Regents of the University of California and the Ocean Institute.
    All rights reserved.
    Last modifed Wednesday, September 13, 2005