Lesson Plan: Motion in the Ocean

This lesson uses web-based resources that are found within the theme with which this lesson is associated. The purpose of the lesson is to help you integrate these web-based resources into your curriculum. If you need more science content information, refer to the text associated with the overall SciGuide topic and with each theme within a SciGuide.

Grade Level:
9–12

Subject Area:
Earth Science

SciGuide Resources:
Lesson on the Coriolis force from NOAA’s Ocean Explorer program, including “the Dishpan Analogy” explanation for this effect. Tutorial on tidal, coastal, and ocean currents NOAA’s “Tides and Water Levels” Tutorial NOAA’s Center for Operational Oceanographic Products and Services (CO-OPS) Web page, with links to data and information about tides, water levels, currents, predictions, weather observations, forecasts, and harmonic constituents. Lesson plans and activities about currents from the University of Southern Maine’s Osher Map Library. Online tutorial with additional details about ocean currents

Standards Addressed:
National Science Education Standards

Content Standard A: Science as Inquiry



Content Standard B: Physical Science


Content Standard D: Earth and Space Science

Content Standard E: Science and Technology

Content Standard F: Science in Personal and Social Perspectives

Time Required:
One 45-minute class period, plus time for student research

Lesson Goal:
Explore causes of ocean currents and waves.

Learning Objectives:
Students will be able to:

Prerequisite Knowledge:

More than 98% of cargo shipped to and from the United States is transported by water. In addition to accurate information on the geography of coastal areas, safe and efficient navigation of coastal waters requires up-to-the minute information on weather and sea conditions. Since these conditions can vary significantly from place to place and can change dramatically in a short period of time, mariners need accurate real-time information to avoid groundings and collisions.

NOAA’s Center for Operational Oceanographic Products and Services (CO-OPS) collects and distributes oceanographic observations and predictions to ensure safe, efficient and environmentally sound maritime transportation.

The Center:

and

CO-OPS also manages a national network of Physical Oceanographic Real-Time Systems (PORTS®) located in major U.S. harbors. The PORTS® network provides real-time information such as water levels, currents, air gap (the clearance between the water surface and the bottom of a bridge), weather data, and other oceanographic information to help mariners avoid groundings and collisions.

Visit http://tidesandcurrents.noaa.gov/products for more information on CO-OPS and their data products. See http://tidesandcurrents.noaa.gov/programs for more information on PORTS® and other CO-OPS programs. While CO-OPS deals mostly with currents along the coast and inside estuaries, other NOAA Program Offices are involved with measuring and understanding currents and circulation patterns in the open ocean. NOAA’s National Oceanographic Data Center (NODC) compiles information from the latest ocean current measurement programs that use current meters and drifters. Through the NODC Web site (http://www.nodc.noaa.gov/General/getdata.html), you can access a variety of data sets containing information on currents and other oceanographic measurements, such as beach temperatures, coastal buoy data, global temperature and salinity data, and photograph collections. For global current data obtained through satellite remote sensing systems visit NOAA’s Ocean Surface Current Analyses - Real Time Web site at http://www.oscar.noaa.gov.

In this lesson, students will explore the relationships between currents, winds, and ocean waves.

Procedures/Instructional Strategy:
To prepare for this lesson, review: Introductory information on tides and currents at http://oceanservice.noaa.gov/topics/navops/ports/ and http://oceanservice.noaa.gov/education/tutorial_currents/

The Currents Subject Review (Click here for a printable copy of the Subject Review), and The “Problems on Winds, Waves, and Currents” worksheet (Click here for a printable copy of the worksheet).

You may also want to review the “Tides and Water Levels” tutorial (http://oceanservice.noaa.gov/education/kits/tides/), which offers a tutorial on the complex systems that govern the movement of tides and water levels, a “Roadmap to Resources” that directs you to specific tidal and current data, and lesson plans for students in grades 9–12.

Ask students to comment on the present-day importance of marine navigation. Students should realize that despite the prevalence of air travel and advances in aerospace technology, Earth’s oceans are still vital to freight transportation, energy production, and recreation. Discuss the importance of real-time information for safe navigation, and have students brainstorm the types of information that would be useful to a present-day mariner. Tell students that their assignment is to learn some basic facts about “ocean motion,” and use this information to solve problems dealing with winds, ocean waves, and currents.

If they have not already done so, have students complete the Currents Subject Review. If you choose to have students work in groups, you may want to assign different tutorial sections to each student. Have each student or student group answer questions in the Currents Subject Review. If students will not have access to the internet, makes enough copies of the Currents Tutorial for each student or student group. To save class time, you may want to assign this portion of the lesson as homework. Lead a discussion of students’ answers to the questions, highlighting ways in which knowledge of tides can be useful and important.

Provide a copy of the “Problems on Winds, Waves, and Currents” worksheet to each student or student group, and have students answer worksheet questions.

Lead a discussion of students’ answers to worksheet questions. Be sure students understand the relationship between winds, ocean waves, and currents.

The correct answers are: 3 feet

Increasing the wind speed by 60 knots would increase the wave height to approximately 12 feet, while increasing the fetch length by 60 nautical miles (nm) would increase the wave height to less than 6 feet.

A 60 knot wind would have to blow over a fetch of about 9 miles to produce a wave 10 feet high.

The distance between the points is 524.6 nautical miles. The total time elapsed is 6 days, 10.25 hours = 154.25 hours. So the estimated current speed is: 524.6 nm ÷ 154.25 hr = 3.40 nm/hr = 3.40 knots The estimated direction of the current is northeast.

The distance between the points is 1,443.68 kilometers = 1.444 x 108 centimeters. The total time elapsed is 14 days, 2.92 hours = 338.92 hours = 1.220 x 106 seconds. So the estimated current speed is 1.444 x 108 cm ÷ 1.220 x 106 sec = 118.4 cm/sec The estimated direction of the current is slightly east of due south.

Since the latitude at the equator is zero, the formula for Coriolis acceleration suggests that the magnitude of this acceleration at the equator is zero.

The latitude of Tijuana is about 32.5° N. A velocity of 10 meters/second is equal to 1,000 centimeters/second. So, the magnitude of the Coriolis acceleration is (sin 32.5° • 1.5 x 10-4 • 1,000) cm/sec2 = 0.537 • 1.5 x 10-4 • 1,000 = 0.081 cm/sec2 The effect is very small.

Even though the effect of Coriolis acceleration on soccer balls, walking humans, etc. is practically negligible, when it acts on very large masses over very long distances, the acceleration becomes significant.

The Bridge Connection

The Bridge is a growing collection online marine education resources. It provides educators with a convenient source of useful information on global, national, and regional marine science topics. Educators and scientists review sites selected for the Bridge to insure that they are accurate and current.

www.vims.edu/bridge - In the “Site Navigation” menu on the left, click on “Ocean Science Topics,” then “Physics,” then one of the headings at the top of the page for links and resources about tides, waves, and currents.

The “Me” Connection

Have students write a short essay on how the Coriolis force affects them personally, even though it only is significant at very large scales.

Extensions

Visit the “Tides and Water Levels” Discovery Kit (http://oceanservice.noaa.gov/education/kits/tides/) for additional resources and lesson plans.

Visit http://www.usm.maine.edu/maps/lessons/nr10.htm and http://www.usm.maine.edu/maps/lessons/nr11.htm for additional lesson plans and activities about currents from the University of Southern Maine’s Osher Map Library.

Visit Multimedia Learning Objects at http://www.learningdemo.com/noaa/. Click on the links to Lessons 8 and 9 for interactive multimedia presentations and Learning Activities on Ocean Currents and Ocean Waves, including an activity involving landing safely on an aircraft carrier by allowing for the Coriolis Effect.

Outcome/Assessment:
CURRENTS Subject Review
Part I: Review Questions for “Currents” Tutorial
(http://oceanservice.noaa.gov/education/kits/currents)

  1. The __________ of currents includes speed and direction components.
  2. Three factors that drive ocean currents are __________.
  3. When a coastal tidal current __________ it moves toward the land and away from the sea. When a coastal tidal current __________ it moves toward the sea away from the land.
  4. As a coastal tidal current moves from ebbing to flooding (and vice versa), there is a period during which there is no current velocity. This period is called __________.
  5. Tidal currents are most strongly influenced by motions of the __________.
  6. When the moon is at full or new phases, the tidal current velocities are __________ and are called __________ When the moon is at first or third quarter phases, tidal current velocities are __________ and are called __________.
  7. “__________ currents” occur when the moon and Earth are closest to each other. “__________ currents occur when the moon and Earth are farthest from each other.
  8. Wave height is affected by wind __________, wind ________, and __________.
  9. Breaking waves are caused by __________.
  10. When a wave reaches a beach or coastline, it releases a burst of energy that generates a current, which runs parallel to the shoreline. This type of current is called a __________.oceanservice.noaa.gov/education.
  11. Water flowing in a longshore current can transport beach sediment and cause significant beach erosion through a process known as __________.
  12. A localized current that flows toward the ocean, perpen¬dicular or nearly perpendicular to the shoreline is called a __________.
  13. Swimmers caught in a rip current can escape by ________.
  14. A long offshore deposit of sand situated parallel to the coast is called a __________.
  15. __________ occurs when winds blowing across the ocean’s surface push water away from an area, causing subsurface water to come up from beneath the surface to replace the diverging surface water. Areas where this occurs are often good for __________, because__________.
  16. Earth’s rotation causes air circulating in the atmosphere to deflect toward the right in the Northern Hemisphere and toward the left in the Southern Hemisphere. This deflection is called __________ .
  17. Between 5 degrees North latitude and about 25 degrees North latitude, surface winds generally blow from the northeast to the southwest, and are known as the ________.
  18. Between 5 degrees North and 5 degrees South latitude, where the winds are generally sporadic and have little or no velocity. This region is called __________.
  19. Between about 35 degrees North latitude and about 55 degrees North latitude, surface winds generally blow from the west, and are known as __________.
  20. Global winds drag on the ocean’s surface, causing the water to move in the direction that the wind is blowing and thus create surface ocean currents. Deflection of these currents by Earth’s rotation produces spiral currents called _________.noaa.gov/education.
  21. Each of the major ocean-wide gyres is flanked by a strong and narrow “western boundary current,” and a weak and broad “eastern boundary current.” The western bound¬ary current of the North Atlantic gyre is called __________, and the eastern boundary current of this gyre is known as __________.
  22. When surface water molecules move by the force of the wind, friction with water molecules below them causes movement of deeper water layers. Deeper layers move more slowly than shallower layers, however, and all layers are deflected by Earth’s rotation (to the right in the Northern Hemisphere and to the left in the Southern Hemisphere). These forces create a spiral effect called __________.
  23. Deep-ocean currents below 100 meters are driven by __________, in a process known as __________.
  24. The global-scale system of deep-ocean currents is some¬times called the __________.
  25. Global ocean circulation resulting from deep-ocean cur¬rents is vital to the world’s food chain because __________.
  26. Global ocean circulation resulting from deep-ocean cur¬rents could be disrupted by global warming if__________.
  27. Ocean and coastal current velocities are typically are measured in __________, which is equal to about ________standard (or “statute”) miles per hour or about __________ kilometers per hour.
  28. Current measurements made with drifters are termed “__________ measurements,” while measurements of the speed and direction of a fluid at a single point are termed “__________ measurements.”

Extensions:

  1. Visit the “Tides and Water Levels” Discovery Kit (http://oceanservice.noaa.gov/education/kits/tides/) for additional resources and lesson plans.
  2. Visit http://www.usm.maine.edu/maps/lessons/nr10.htm and http://www.usm.maine.edu/maps/lessons/nr11.htm for additional lesson plans and activities about currents from the University of Southern Maine’s Osher Map Library.
  3. Visit Multimedia Learning Objects at http://www.learningdemo. com/noaa/. Click on the links to Lessons 8 and 9 for interactive multimedia presentations and Learning Activities on Ocean Currents and Ocean Waves, including an activity involving landing safely on an aircraft carrier by allowing for the Coriolis Effect.

Classroom Resources:
Computers with Internet access for students

Lesson Plan File:
(entire word document containing complete lesson plan and supporting attachments)
Download Here (pdf, 230)

Student Work Description:
Student notes on currents data.

Sample of Student Work:
Download Here

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