1. Seasons and Sun
Investigation 3
Contrasting Cases
Seasons and Sun

2. Today’s discussion topics
How do seasons and sunlight differ between different cities around the world?
How are seasons similar and different between different cities?
Do different cities get different amounts of sunlight?
What are the reasons for these types of similarities and differences?
Contrasting Cases
Seasons and Sun

3. Cities around the world
Teacher can introduce today’s contrasting cases by telling students that they are going to look at the average amount of sunlight that ten different cities get per day in January and June. They will also look at the average high temperature during these months in these cities. This exercise is designed so that small groups of students (~3-4) can look at 4 cities each. The student worksheets that accompany this lesson include five combinations of cities (4 each), so you can divide your students into five or more groups, and assign them either A, B, C, D, or E.
The main idea we are trying to help students understand in this lesson is that latitude (i.e., if a city is located in the Northern or Southern hemisphere) is crucial in determining the amount of sunlight they get. After examining the different cities, they should learn that there is a relationship between amount of sunlight and seasons (e.g., if January is warmer or colder than June) depending on the latitude on which a city is located (they may also see that there are differences in average temperature depending on distance from the equator).
Contrasting Cases
Seasons and Sun

4. Group work
Please look at the charts on your worksheet and answer the questions with your teammates.
Give the students about minutes to discuss the cities that they have been assigned.
Contrasting Cases
Seasons and Sun

5. Class discussion
Each group should choose one representative to present their findings to the class.
Which cities have more average sunlight hours in January? How about June?
Which cities are, on average warmer in January? How about June?
While each student is presenting their group’s findings, the teacher can display the following slide, which has all 10 cities listed with its information, so students can try to determine patterns across all of the cities.
Contrasting Cases
Seasons and Sun

6. Average Sunlight Hours (January) Average Sunlight Hours (June)
City
Latitude
Longitude
Average Sunlight Hours (January)
Average Sunlight Hours (June)
Average high Temperature (°F) (January)
Average high Temperature (°F) (June)
Antananarivo, Madagascar
18° South
47° East
13.1
11.0
79°
70°
Athens, Greece
38° North
23° East
9.8
14.8
55°
88°
Baghdad, Iraq
33° North
44° East
10.2
14.3
60°
106°
Cape Town, South Africa
33° South
18° East
14.2
9.9
64°
Edmonton, Canada
53° North
113° West
8.0
17.0
19°
Lima, Peru
12° South
77° West
12.8
11.4
78°
67°
Phoenix, AZ USA
112° West
14.4
104°
Pittsburgh, PA USA
40° North
80° West
9.6
15.0
37°
80°
Sydney, Australia
151° East
62°
Tokyo, Japan
35° North
139° East
10.0
14.5
50°
77°
Contrasting Cases
Seasons and Sun

7. Average Sunlight Hours (January) Average Sunlight Hours (June)
City
Latitude
Longitude
Average Sunlight Hours (January)
Average Sunlight Hours (June)
Average high Temperature (°F) (January)
Average high Temperature (°F) (June)
Antananarivo, Madagascar
18° South
47° East
13.1
11.0
79°
70°
Athens, Greece
38° North
23° East
9.8
14.8
55°
88°
Baghdad, Iraq
33° North
44° East
10.2
14.3
60°
106°
Cape Town, South Africa
33° South
18° East
14.2
9.9
64°
Edmonton, Canada
53° North
113° West
8.0
17.0
19°
Lima, Peru
12° South
77° West
12.8
11.4
78°
67°
Phoenix, AZ USA
112° West
14.4
104°
Pittsburgh, PA USA
40° North
80° West
9.6
15.0
37°
80°
Sydney, Australia
151° East
62°
Tokyo, Japan
35° North
139° East 10
14.5
50°
77°
Ask the students what they notice about the highlighted cities. (They are all in the Southern Hemisphere, and are warmer in January than June.) What can they conclude about this? You can cue them in by asking if they are used to it being warmer in January or in June, and leading them into a discussion about their location (the Northern Hemisphere).
Contrasting Cases
Seasons and Sun

8. Cities around the world
This is the same slide that was shown at the beginning. In order to bring it back to the idea that latitude is what determines how much sunlight a city gets, and its pattern of seasons, the teacher can now point out to the students the locations of each of the cities and their distance from the equator.
Contrasting Cases
Seasons and Sun