Ranges from 0 km to 12 km Lowest layer of the atmosphere Where we live Where almost all of the Earth’s

weather occurs “Tropo” means turning or changing; named

because conditions are always changing Shallowest layer of the atmosphere with almost

all of the mass of the entire atmosphere As altitude increases, temperature drops. Why? Because the air gets less dense as altitude

increases.

Ranges from 12 km to 50 km “Strato” means layer or

spreading out The ozone layer is located in

the upper stratosphere, and it protects the Earth by absorbing and filtering out the sun’s harmful U-V rays.

As altitude increases, temperature increases. Why? The upper stratosphere contains the ozone layer which

absorbs energy and turns it into heat causing the temperature to be greater in the upper stratosphere.

Ranges from 50 km to 80 km Middle layer of the atmosphere “Meso” means middle protects the Earth from

most meteors As altitude increases, temperature drops. Why? The lower mesosphere is closer to the ozone

layer (hot) and the air gets less dense with altitude so it gets colder.

Ranges from 80 km and beyond very thin air “Thermo” means heat Broken into 2 layers- The Ionosphere and the

Exosphere As altitude increases, temperature increases.

Why? Although the air is very thin, the molecules are

the first to receive energy from the sun, so the molecules are very hot.

Is the lower portion of the Thermosphere Ranges from 80 km to 550 km where gas molecules become electrically charged

particles called ions Radio waves bounce off ions and back to Earth Where the Aurora borealis is found (Northern

Lights)

Is the outer portion of the Thermosphere Ranges from 550 km to outer space  “Exo” means outer satellites orbit here