Outreach 2014

 

CANDAC Outreach

Title: Understanding the Seasons

Grade Level: Elementary

Subject: Science and Technology

Duration and frequency of activity: 60 minutes

 

Lesson at a glance

A globe and light source are used to explore why most parts of Canada experience four distinct seasons and why the Poles are cold.

Focus question(s)

Why do most parts of Canada experience four distinct seasons? Why are the Poles cold?

Background

To understand why it is cold in the Poles, we need to consider what causes the Earth’s seasons and why, when it is summer in the Arctic, it is winter in the Antarctic (and vice versa).

Important things to know:

• Earth spins on its axis approximately once every 24 hours creating the diurnal cycle.

• Earth orbits the Sun once every 365 ¼ days. (A leap year every 4 years is needed to maintain a reliable calendar.)

• The seasons in Canada are mainly attributed to the Earth’s 23.5° tilt on its axis.

• When the Northern Hemisphere is tilted towards the Sun it experiences summer while the Southern Hemisphere simultaneously experiences winter, and vice versa.

• Spring and autumn occur when the Sun is positioned above the equatorial latitudes.

• Solstice occurs when the Sun has reached its highest position in the sky as viewed from the North or South Pole. The word solstice comes from the Latin sol (sun) and sistere (to stand still); at the solstices, the Sun stands still in declination and the seasonal movement of the Sun's path (as seen from Earth) comes to a stop before reversing direction.

• Equinox occurs when the center of the Sun is directly in line with Earth’s equator and Earth is tilted neither toward nor away from the Sun. The name equinox is derived from the Latin aequus (equal) and nox (night), because around the equinox, the night and day have approximately equal length.

• Solstices and equinoxes are related to the seasons, as they mark the beginning or midpoint of winter or summer.

Instructions

 



 

1. Discuss the four seasons (winter, spring, summer and autumn/fall) with students. Use the photos available at http://www.flickr.com/photos/pfogal/266725877/in/set-72157594346009264/ or use your own as visuals (photos, books) to help students describe each season.

2. Have each student (or groups of students) choose a season and create a collage to represent that season. Encourage students to be creative and use materials available in the classroom (magazine photos, drawings, words, newspapers, etc.). Group the collages by season and display in the classroom.

3. Use a globe, lamp and flashlight to demonstrate the reasons for the seasons. Use the four questions in the table below as a guide for performing the demonstrations. You may like to ask the question to the class; allow students to make their best guesses; do the demonstration; and then ask students the question again.

4.Guide students through Understanding the Seasons worksheet.

Materials

• Visuals of each of the four seasons

• Globe

• Shadeless lamp or bright flashlight

• Piece of cardboard with 3cm diameter hole cut in the center

• Understanding the Seasons worksheet (1 per student)

• 2 or 3 thermometers (for extension activity)

• Black cardboard (for extension activity)

Instructional method

• Worksheet

• Discussion

• Oral questioning

• Demonstration

Assessment

 

Ability to provide characteristics of each of the four seasons.

Participation in demonstrations and classroom discussions.

Demonstrates an understanding of diurnal cycle, reasons for the seasons and variation in length of daylight.

Ability to draw diagrams of Earth during Northern Hemisphere summers and winters.

Helpful links

Arctic photos can be found at http://www.arcticphoto.com/.

More information about about Canadian seasons can be found at http://www.cic.gc.ca/english/newcomers/before-seasons.asp.

Extension/adaptations

• Attach two thermometers to separate pieces of black cardboard. Stand one piece vertically and another at an angle. Aim the light in the direction of the cardboard, making sure both are at the same distance from the light. One thermometer should be directly illuminated and the other should be indirectly illuminated. If you have a third thermometer, place it away from the light source as the control, so that you can compare the ambient temperature in the room with the readings you get under the light. Wait ten minutes, and then check the thermometers to see which cardboard is warmer. Ask students to discuss with a partner before the class discussion. Discuss the findings with your students.

Source

 

1. Alberta Astronomy Resource Group (2004): “Reasons for the Seasons.” The Royal Astronomical Society of Canada Calgary Centre retrieved January 19, 2011.

2. Nieuwendam, A.T. and J. Xavier (2010): “Why is it Cold in the Polar Regions?” Polar Science and Global Climate: An International Resource for Education and Outreach, ISBN 978-1-84959-593-3.