The Reasons for the SeasonsNotes & Study Guide

Review of Time Concepts

Day – the amount of time it takes Earth to rotate once on its axis

Month – the amount of time it takes the moon to revolve around Earth one time

Year – the amount of time it takes for the Earth to revolve around the Sun one time

Earth’s Orbit

Earth’s orbit is elliptical. However, the eccentricity is so low that you might confuse it with a perfect circle!

Seasons in the Northern Hemisphere

Earth’s axis is tilted 23.5 degrees. The axis points to the North Star (Polaris).

Equinoxes and Solstices

Each marks the beginning of a new season:

Summer Solstice – longest day of the yearWinter Solstice – shortest day of the yearAutumnal Equinox – equal day and nightVernal (Spring) Equinox – equal day and night

Axial Tilt & the Seasons

The hemisphere tilted towards the Sun experiences summer (more direct solar angle, more energy absorbed, higher temperatures)

The hemisphere tilted away from the Sun experiences winter (less direct solar angle, lower energy absorption, lower temperatures)

To Study…

1. This presentation2. Lab activities completed in class3. Quizlet

Quiz is worth approximately 21 points and is two pages long.