Science, 2009
 
  Grade Level:   9-12  
  EALR 4:   Earth and Space Science  
  Big Idea:   Earth Systems, Structures, and Processes (ES2)  
  Core Content:   Energy in Earth Systems                   
  Description:   In prior grades students learned about planet Earth as an interacting system of solids, liquids, and gases, and about the water cycle, the rock cycle, and the movement of crustal plates. In grades 9-11 students learn how the uneven heating of Earth's surface causes differences in climate in different parts of the world, and how the tilt of Earth's axis with respect to the plane of its orbit around the Sun causes seasonal variations. Students also learn about the essential biogeochemical cycles that continuously move elements such as carbon and nitrogen through Earth systems. These major ideas about energy inputs and outputs in and around the Earth help students understand Earth as a dynamic system.  
  Content Standard:   9-11 ES2A Global climate differences result from the uneven heating of Earth's surface by the Sun. Seasonal climate variations are due to the tilt of Earth's axis with respect to the plane of Earth's nearly circular orbit around the Sun.  
 
 
 
Students are expected to:
  • Explain that Earth is warmer near the equator and cooler near the poles due to the uneven heating of Earth by the Sun.
  • Explain that it's warmer in summer and colder in winter for people in Washington State because the intensity of sunlight is greater and the days are longer in summer than in winter. Connect these seasonal changes in sunlight to the tilt of Earth's axis with respect to the plane of its orbit around the Sun.