Chapter 15Atmosphere

15.1 Earth’s AtmosphereComposition

1. Gas (78% N2, 21% O2)

2. Solids & Liquids

- Dust, salt and water

Structure

2 lower layers

1. Troposphere

- Closest to ground (~ 11 miles high)

- Contains most gas and water vapor

- Where weather occurs

2. Stratosphere

- 2nd layer (~21 miles high)

- Contains ozone layer

3 Upper layers

3. Mesosphere

- Coldest layer (~40 miles high)

- Meteors burn up (shooting star)

4. Thermosphere- Hottest layer (~1,000-2,000 °F)- Aurora occur here- Contains Ionosphere (charged particles)- ~ 430 miles high- Space Shuttle & ISS orbit here

5. Exosphere- Uppermost part of Earth- Space is after- ~ 6200 miles high

Atmospheric Pressure- Most dense at sea level- Barometer- Measures air pressure

Temperature - Atmosphere divided into layers by temperature

Ozone layer

- Shield & absorbs UV rays

- CFC’s destroy ozone

15.2 Energy from Sun

Energy Transfer

Radiation

- Transfer energy by electromagnetic waves

- Light & heat Ex) Fire, Sun

Conduction

- Heat transfers as molecules collide

Convection

- Heat transfer through gas or liquid

Ex. Dryer, Oven

Water Hydrosphere

- All water on Earth’s surface

- 97% is salt water

- Most fresh water is in polar ice caps

Water Cycle

- Movement of water between Earth & atmosphere

15.3 Air Movement

Wind Formation

- Uneven heating of Earth

Coriolis effect http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/fw/crls.rxml

http://www.classzone.com/books/earth_science/terc/content/visualizations/es1904/es1904page01.cfm?chapter_no=19

- Water & air move Right above equator & Left below

Wind Systems

1. Jet stream- Belts of strong wind in upper

troposphere

2. Doldrums- Windless area at equator

3. Prevailing Westerlies- Move most weather in

USA- west to east

4. Sea breeze (Day) - Wind blowing from sea

to land

5. Land breeze (Night) - Wind blowing from

land to sea