Title: Wind Circulation, Surface Currents, and Climate
Author: David Cox
Subject Area: Earth Science
Grade: 6-8
Description of Lesson:
Students will evaluate wind patterns after looking at wind surface current maps using overlays to
identify major climate regions.
Length of Lesson: 2-45 min.
Student Objectives:
Students will be able to describe the connections between wind patterns, surface currents, and ocean
climate zones.
Materials:
· map of world with climate zones
· overlay of ocean currents( copy machine and overhead transparency)
· overlay of global wind patterns
· question sheet
· colored pencils
· red and blue china markers
-vocabulary list
Procedure:
At the start of class demonstrate the following:
Use the flashlight demonstration described below to model how the sun heats up the surface
of the earth as the angle of the incoming sun strikes the earth. The Coriolis effect can also be
demonstrated with a globe or old turn table or even a swivel stool. While spinning the globe,
take an overhead pen and mark straight down from the North Pole to the equator. The mark
should make a curved path the opposite direction that the earth is rotating. This results in
creating the trade winds near the equator and all the other major wind patters at 30 degrees
and 60 degrees above and below the equator. Convection cells at these latitudes create
ascending and descending air flows that are then affected by the spinning of the earth from
west to east. The ―Coriolis effect‖ is an inertial force described in 1835 by Gustave-Gaspard
de Coriolis (1792–1843). Coriolis showed that, if the ordinary Newtonian laws of motion of
bodies are to be used in a rotating frame of reference, an inertial force—acting to the right of
the direction of body motion for counterclockwise rotation of the reference frame or to the left
for clockwise rotation—must be included in the equations of motion.
Taken from:
CURRICULUM IN MARINE SCIENCES
FOR GRADES 4 - 8
UNIVERSITY OF CALIFORNIA, LOS ANGELES
MARINE SCIENCE CENTER
revised for UCLA OceanGLOBE, 4/04
Follow the lessons below and refer the .pdf file attached (currentsentire.pdf) for other lessons and
better quality pictures.
Scientific Explanation:
Wind is air moving across the surface of the Earth. Ultimately all winds are generated by unequal
heating of the Earth by the sun. Because the sun is millions of miles away from the earth, the rays of
light and heat from the sun that reach the surface of the Earth are parallel to one another. But the
Earth is round, and only at the equator does energy from the sun fall on a flat surface at a right angle
to the sun. At the poles solar radiation falls on surfaces that curve sharply away from the sun.
To demonstrate this, shine a flashlight on a flat surface so that the beam of light is perpendicular (at a
right angle) to the surface you are shining it on. Draw a circle around the spot of light. Now tilt the flat
surface so that it is at a 45 degree angle to the flashlight. Now the spot of light shining on the surface
is oblong, not round, and it is now almost two times larger that the first spot. The spot of light is also
dimmer now because the light of the flashlight beam is spread over a larger area than before. This
same principle applies to the Earth and sun. The equator will always receive more energy from the
sun than will comparable areas north or south of the equator. Also, the surface of the Earth directly
beneath the sun at high noon also receives more energy than do areas to the east or west. Thus the
Earth’s surface along the equator is always warmer than are the Polar regions, and it is always
warmer at noon than at dawn and dusk. The result is that the heat budgets of different regions of the
Earth are always unequal because the Earth is always tilted at an angle to the sun and because it
spins around 24 hours a day, 365 days a year. Nonetheless, averaged over each day/night period,
approximately twice as much heat reaches the equator than the poles each year.
Assessment:
Students will be evaluated by answering the questions at the end of this activity sheet and by the
teacher moving around to each group checking for understanding.
Students should be able to demonstrate the heating of the earth and the Coriolis effect with a globe
and flash light.
Missouri and Kansas Standards Addressed:
Kansas Science Standards:
STANDARD 4: EARTH AND SPACE SCIENCE EARTH AND SPACE SCIENCE –
Grades 8-12 Benchmark 1: The student will develop an understanding of the sources of energy that
power the subsystems and cycles of the dynamic earth: the geosphere, hydrosphere, atmosphere and
biosphere.
Missouri Science Standards (GLE’s):
Strand 5: Processes and Interactions of the Earth’s Systems (Geosphere, Atmosphere, and
Hydrosphere) 2. Earth’s Systems (geosphere, atmosphere, and hydrosphere) interact with one
another as they undergo change by common processes)
Wind Circulation, Surface Currents, and Climate
Atmospheric cells and ocean gyres redistribute heat from low to high latitudes, which
influences climate, weather, and ocean temperature. Surface currents are created by the prevailing
wind system.
Objective:
Students will be able to describe the connections between wind patterns, surface currents, and ocean
climate zones.
Materials:
· map of world with climate zones
· overlay of ocean currents
· overlay of global wind patterns
· question sheet
· colored pencils
· red and blue china markers
Vocabulary list is also attached
Procedures: (See illustrations below and also see attached .pdf file)
1. Teacher reviews the wind patterns of the Earth. Explain the Coriolis effect and how it produces
gyres in surface currents. Demonstrate the heating of the earth with a flash light and show the Coriolis
effect with a rotating globe. Pass our global wind patterns sheet figure 4 in color if possible.
2. Have students break into groups of 2-3 to study this occurrence. Each group has a climate map,
overlays of wind patterns and surface currents.
3. Students color the ocean climate zones in four different shades of blue, with the tropics being the
darkest.
4. Students color the warm surface currents with a red china marker and the cold currents with a blue
china marker. Overlay the surface current sheet on top of the climate zone map.
Evaluation:
N. Pacific, California, N. Equatorial)
How many other gyres are formed in the open oceans? (4)
in latitude span? (the Atlantic)
Evaluation Continued:
Now place the wind pattern overlay over the climate zone map. Answer these questions:
Which climate zone contains the westerlies? (Temperate zone)
What would happen if the trade winds became weaker? (The equatorial current would become weaker
and create an El Niño effect.)
Global Wind Patterns Figure 4