LAYERS OF ATMOSPHERE

In what ways is the atmosphere important to survival of life?

Layers

Troposphere

1st layer of atmosphere Tropo means changing or turning Where earths weather occurs Varies from 16km to 9km at poles Top of troposphere is about -60 C

Stratosphere

Extends from top of troposphere to about 50 km above earth

Strato means spread out or layer Contains ozone layer Top hotter than bottom

Mesosphere

3rd layer Begins about 50 km above earth extends

to 80 km Outer temps approach -90 C Meso means middle Dissolves meteoroids, chunks of metal

and stone by friction Presence of noctilucent clouds

Made of frozen air no water vapor Usually appear between 50 and 70 latitude

Thermosphere

4th layer Only .001% as dense as troposphere air Starts about 80 km above earth and

moves out indefinitely. Thermo means hot Approx 1800 C but feels cooler

Ionosphere Starts about 80 km extends to 400 km Energy from sun causes particles called

ions to become electrically charged Radio waves bounce off these ions

Exosphere

Exo means outer Starts at 400 km and extends out

thousands of kilometers