Upwelling and Wind Patterns

Materials / Preparation

See Ocean Oasis: Upwelling Activity for instructions for modeling upwelling.
A Brief Introduction to Upwelling (page 32 of Apples and Oceans) has an excellent description of upwelling and an Atlas/Aeolus activity. This resource is provided with permission from Lawrence Hall of Science. (Requires Adobe Reader and may take a while to open.)
Note: Go by the page number printed at the bottom of the page, not the page number Adobe Reader assigns.
Per group of 2-4 students:

2 transparent pans at least 5" x 9" x 2" deep
food color
ice
water
medicine dropper
water pitcher
small container
flexible plastic drinking straws for each student.
Copy of the instruction sheet found at the Ocean Oasis: Upwelling Activity website

One plastic inflatable globe or balloons
Wet-erase markers (if using the globe) or permanent markers (if using the balloons)
Map of California

Grouping

Class discussion and groups of two to four

Teacher tips

The Ocean Oasis: Upwelling Activity has excellent instructions for the upwelling demonstration. Unfortunately, their explanation of why upwelling occurs contains some inaccuracies. For understanding upwelling, it is better to use the information on page 32 of the Apples and Oceans activity, which contains an excellent description of the forces that cause upwelling to occur.

Procedures

Review the investigations from the previous activity. Ask students to predict what would happen if the warm surface waters were moved (how could they be moved?)—what would replace them?
Hand out instructions and materials necessary for students do the Ocean Oasis: Upwelling Activity and give them verbal directions.
Ask the students what happens to the cold, deep water when the surface waters are pushed away from the shore by the wind? Have students draw a side view of what they observed in the pan. Allow students to compare drawings until the majority of the class agrees on a single drawing that accurately represents what happened. Introduce the term “upwelling” at this point.
a. Review the process of upwelling, explaining how the movement of surface waters away from shore causes deeper, colder waters to rise. Ask the students what would be carried to the surface with the colder, deeper waters?
b. Based on the results of the Making Algae Grow lab, how would this movement of nutrients affect the phytoplankton? If phytoplankton are blooming, what other organisms would be affected?
c. Use this as a springboard to work back up through the food web.
d. Re-introduce the pictures from Lesson 1, Activity 1. Ask which one might represent the sea during upwelling?
Using the map of California, ask students what direction the winds would have to be blowing to cause surface waters to move off the western coast of California.
a. Next, do the activity on pages 32-34 of Apples and Oceans to demonstrate how northerly winds are bent towards the west because of the spinning of the Earth.
End the class by asking students to make predictions about the seasonality of what they are observing. Do you think the winds are always blowing in this direction? Does upwelling happen throughout the year? Is this a cycle? Is upwelling predictable? Is it an unusual event? What abiotic factors change throughout the seasons? How do abiotic factors affect upwelling? This final discussion should carry over into the first activity of following lesson.

Extension

Requires two 50-minute class periods. Do the Apples/Oceans activity (pages marked 15-31).

Resources used

Ocean Oasis: Upwelling Activity
http://www.teachingboxes.org/catalog.jsp?id=DLESE-000-000-008-928

Apples and Oceans
http://www.teachingboxes.org/upwelling/resources/ApplesandOcean.pdf

Map of California
http://www.teachingboxes.org/catalog.jsp?id=TBOXR-000-000-000-057

Making Algae Grow
http://www.teachingboxes.org/upwelling/lessons/lesson1_supplement/MakingAlgaeGrow.pdf