Key Concepts: Key Vocabulary:

WEATHER AND WATER: Investigation 3: Seasons and Sun

Approximate Timeline: 10 sessions

Standards Addressed: S1 C2 PO1, S1 C2 PO5, S1 C3 PO2, S1 C3 PO3, S1 C3 PO4 S4 C3 PO1

Learning Goals: I will be able to graph and analyze sunlight data. I will be able to model the Earth-Sun relationship while paying particular attention to the rotation, tilt, and revolution.

Extra Resources:

Earth’s axis of rotation tilts at 23.5° and points to the North Star.

The solar angle is the angle that light from the sun strikes Earth’s surface.

Beam spreading is the increase in an area covered by a beam if light as there’s an increase in the solar angle.

Assessments:

Response Sheet: Seasons and Sun End of part 2

Mid-Summative Exam 3

End of investigation

http://vortex.plymouth.edu/sun/sun3.html

Writing Prompt Idea #2: You are a taxpayer in Arizona. The legislature will be voting to fund a new energy plant. Decide which energy source will be the best option for Arizona. Write an editorial persuading the legislature to build this type of energy plant. Choices for energy sources include: wind, dams, fossil fuels, nuclear, or solar. Science: S5 C3 PO1 Writing: S3 C4 PO1

Writing Prompt Idea: You are Copernicus. Write a letter to fellow scientists convincing them that you have the “true” model of the universe. Explain why Ptolemy’s model of the universe with the Earth at the center is false. Include diagrams in your letter. Science: S1 C4 PO1 Writing: S3 C3 PO4; S3 C4 PO1

Fall (autumnal) equinox

Spring (vernal) equinox

Summer solstice

Winter solstice

Solar Angle

Rotation

LEARNING GOALSLEARNING GOALS• Investigation 3- Seasons and Sun

• Enduring Understanding:

• Seasons are related to the amount of solar energy transferred to Earth, and that amount of energy transferred is affected by latitude, tilt of Earth’s axis, revolution, and rotation.

• Learning Goals:

• I will graph monthly day-length data for a single location to look for a pattern.

• I will use a globe and light bulb to model daily and seasonal variations in day length.

• I will explain how the tilt of Earth’s axis and Earth’s revolution around the sun produces seasons.

• I will discuss seasonal variation in day length as a consequence of axis tilt, rotation, and revolution.

• I will use light sources and surfaces to model beam spreading.

• I will explain how beam spreading reduces the intensity of solar radiation.

Seasons and Seasons and SunSun

What causes SEASONS? ************************************

Quick Write: 5 Minutes

MOVIE:MOVIE:Reasons for the SeasonsReasons for the Seasons

Video in the file under Seasons

SUNSHINESUNSHINE• I’ve heard it said that December

21 is the shortest day of the year.• Why would someone say that?• Do we have fewer than 24 hours

on December 21?• We get fewer hours of sunlight in

winter, more hours of sunlight in summer, but the sum of light and dark hours always equals 24.

SUNSHINESUNSHINE• If it is true that there is a shortest day, is there also a longest day of the year?

•June 21

SUNSHINESUNSHINE• How many hours of sunlight will

we have today?• Sunrise= 5:49am• Sunset= 7:05pm• Calculate the hours and minutes.

–Hint: Calculate the hours and minutes between sunrise and noon, then between noon and sunset, then add them together.

SUNSHINESUNSHINE• Example:

– Sunrise=6:24am– Sunset=6:44pm

• 6:24-11:24= 5 hours• 11:24-12:00= 36 minutes

– So 5 hours, 36 minutes• 12:00-6:00= 6 hours• 6:00-6:44= 44 minutes

– So 6 hours, 44 minutes• Total= 12 hours, 20 minutes

GRAPH QUESTIONSGRAPH QUESTIONS• What does the graph reveal about the

amount of daylight over a year in Berkley?– Days get longer from January to June,

shorter from June to December• When do people in Berkley have their

longest day? Shortest?– Longest= June, Shortest= December

• When do people in Berkley have about 12 hours of daylight?– March and September

GRAPH QUESTIONSGRAPH QUESTIONS• How many hours of daylight do

people in Berkley have on their longest day? On their shortest day?–Longest= 14+, Shortest= 9+

• In what season do people in Berkley have their longest day? Their shortest day?–Longest= Summer, Shortest= Winter

GLOBAL DAYLIGHTGLOBAL DAYLIGHT• When one location on Earth has 14

hours of daylight, is all the rest of the world having 14 hours of daylight as well?

• Is the longest day of the year the same length all over the world?

• Is the longest day of the year the same day all over the world?

• Are the longest days always in the summer? Are the shortest days always in the winter?

READING:READING:“Wendy and Her “Wendy and Her

Worldwide Weather Worldwide Weather Watchers”Watchers”

page 12page 12

Wendy and Her Worldwide Weather Watchers

****ANSWER ALL QUESTI ONS I N COMPLETE SENTENCES. USE THE QUESTI ON TO ANSWER THE QUESTI ON. 1. Which locations have the greatest number of hours of daylight on J une 21? The f ewest hours of daylight? Greatest=______________________________________________________________________________________________________________________________________________________________________________________________________________Fewest=____________________________________________________________________________________________________________________________________________________________________________________________ ___________________ 2. Which locations have the longest hours of daylight on December 21? The shortest hours of daylight? Longest=_______________________________________________________________________________________________________________________________________________________________________________________________________________Shortest=___________________________________________________________________________________________________________________________________________________________________________________________ ___________________ 3. Alpena, Michigan, is located 45 degrees north of the equator. How much daylight do you estimate they have on J une 21? On December 21? J une 21=_________________________________________________________________ December 21=_____________________________________________________________ 4. Boulder, Colorado, has a latitude of 40 degrees North. Wellington, New Zealand, has a latitude of 41 degrees South. Which city has the longest amount of daylight on J une 21? How do you know? _____________________________________________________________________________________________________________________________________________________________________________________________________________________