Today is Monday, December 17, 2012 Homework: Read Chapter 8, Lesson 1 Warm Up: Discuss with your shoulder partner: “What do you know about the atmosphere?”

Goal for Today SWBAT accurately describe and understand what the atmosphere is and how air moves

Today = Chapter 8, Lesson 1 Tuesday = Chapter 8, Lesson 2; Tests Back Wed. = Chapter 8, Lesson 3 Thursday = Intro to Science Fair (April 3rd) Friday = Chapter 8, Lesson 4

Let’s see what our friends Tim and Moby have to say about the atmosphere….

Earth’s atmosphere is made up of 5 layers Troposphere – most of Earth’s air and weather in this layer (8-15km) Stratosphere – ends at 50 km Mesosphere – ends at 85 km Thermosphere – ends at 600 km Exosphere – 600 km into outer space As you go up, temperature and air pressure decrease until you hit the thermosphere (temperature increases here)

Convection currents Cool air – gas particles more packed together  heavier  high pressure The air, without heat (or without energy) moves more slowly, so air particles don’t spread out, but stay clumped together.

Hot air – gas particles less packed together  lighter  low pressure Air, with lots of heat (or lots of energy) moves quickly. Its particles bounce all over the place, spreading out.

Every liter of cool air heavier than liter of hot, so cool air sinks and hot air rises Warm air will have less air particles, more spread out; cold air will have more air particles, closer together. This causes movement of air with water and land warming and cooling at different rates