Question

activity a: reasons for seasons
get the gizmo ready:

• on the space tab, drag the person to 40° n latitude. (this is the latitude of new york city.)
• check that show sun - rays is on

introduction: a season is a major division of the year, based on regular weather changes. most of the world has four seasons - winter, spring, summer, and autumn (fall). the summer solstice is the first day of summer. the winter solstice is the first day of winter. the solstice dates usually (but not always) fall on june 21 and december 21
question: why is it colder in winter than summer?

1. form hypothesis: in the northern hemisphere, why do you think it is colder in december than in june?
2. collect data: select the earth tab. record the following data for the 40° n location

• the number of sun - rays hitting the solar panel on june 21 and december 21.
• the temperature on each date
• the june 21 hours of daylight and december 21 hours of daylight
• the angle of the sun’s rays on each date (to do this, turn on show protractor. choose a ray to measure, and align the arrow with the t in the middle of the protractor. estimate the angle where the ray crosses the edge of the protractor.)

date rays on panel temp. (°c) daylight hours sun ray angle
june 21
december 21

1. analyze: look at your data table.

a. on which date are there more hours of daylight?
b. on which date does more sunlight hit the solar panel?
c. how does the angle of sun rays relate to the temperature?

1. draw conclusions: why is it colder in winter than summer? give two reasons

Explanation:

Step1: Hypothesis

In the Northern Hemisphere, it is colder in December than in June because the Sun's rays hit the Earth at a more oblique angle in December, leading to less - concentrated solar energy, and there are fewer hours of daylight.

Step2: Data collection (assumed values for illustration as no actual data given)

• June 21 (Summer Solstice in Northern Hemisphere): More Sun - rays hit the solar panel, higher temperature (e.g., 25°C), more daylight hours (e.g., 15 hours), and a steeper Sun - ray angle (e.g., 70°).
• December 21 (Winter Solstice in Northern Hemisphere): Fewer Sun - rays hit the solar panel, lower temperature (e.g., 5°C), fewer daylight hours (e.g., 9 hours), and a shallower Sun - ray angle (e.g., 30°).

Step3: Analysis

A

June 21 has more hours of daylight.

B

June 21 has more sunlight hitting the solar panel.

C

The steeper the angle of the Sun's rays, the higher the temperature. When the Sun's rays hit at a steeper angle, the same amount of solar energy is concentrated over a smaller area, leading to higher temperatures.

Step4: Conclusion

It is colder in winter than in summer in the Northern Hemisphere for two reasons: 1) The Sun's rays hit the Earth at a more oblique angle in winter, spreading the solar energy over a larger area and providing less heat per unit area. 2) There are fewer hours of daylight in winter, so the Earth has less time to absorb solar energy.

Answer:

1. Hypothesis: In the Northern Hemisphere, it is colder in December than in June because the Sun's rays are more oblique and there are fewer daylight hours in December.
2. (Data should be filled in the table as per actual measurement)
3. A. June 21

B. June 21
C. The steeper the angle of Sun - rays, the higher the temperature.

1. It is colder in winter than summer because the Sun's rays are more oblique in winter, spreading energy over a larger area, and there are fewer hours of daylight for the Earth to absorb solar energy.