Layers of the Atmosphere

1. Troposphere 0 to 12 km from earth’s surface Where weather occurs We live here. Contains almost all of the mass of the atmosphere. As altitude increase temperature decreases (colder).

2. Stratosphere From the top of troposphere to 50 km. As altitude increase, temperature increases (warmer because of ozone). Contains the ozone layer Jets fly here to avoid weather (Jet Stream)

2a. Ozone Ozone = O3 Ozone is produced by lightning 90% of ozone is in the stratosphere Protect the earth from UV radiation from the sun. If found in the troposphere, it is a pollutant.

3. Mesosphere 50 – 80 km above earth’s surface As altitude increase, temperature decrease (colder). Meteorites that have been burnt up enter as a shooting star.

4. Thermosphere Divided into two sections, the ionosphere & the exosphere Begins at 80 km from the earth’s surface Ends in outer space Therm – heat As altitude increases, temp. increases, hot! This is where the meterorites first burn up! Air is very thin – molecules spread out

5. Ionosphere 80 to 550 km, 1st layer of the Thermosphere Energy from the sun causes gas molecules to have a charge + or – (ions) Aurora Borealis occur here. Particles from the sun enter the atmosphere at the poles.

How Auroras are caused: Charged particles from the sun interact with the earth’s magnetic field The particles (or ions) enter the atmosphere near the poles Northern Hemisphere – Northern Lights Southern Hemisphere – Aurora Australis

Aurora Borealis The RED color is from the interaction with Nitrogen. The GREEN color is from the interaction with Oxygen.

6. Exosphere Exo = Outer (EXIT) 2nd layer of the thermosphere 550 km above earth to outer space Satellites orbit here

Magnetosphere (this isn’t a layer) The earth acts as a large magnet All magnetic objects produce invisible lines of force and creates charged molecules Earth’s magnetic line run from North to South Pole The magnetic field stops solar winds The charged molecules create auroras in the ionosphere