Atmosphere Troposphere Closest to Earth Tropo means turning

Atmosphere

Troposphere �Closest to Earth �Tropo means turning or changing � 0 -12 km �We live in this layer �Tropo means changing, and conditions change more here than in any other layer �This is where weather occurs �As altitude increases, the temperature decreases.

Troposphere continued �Contains most of the mass of the atmosphere �On average: 1 kilometer increase in altitude=6. 5 degrees Celsius cooler �

Stratosphere �Strato means “layer” or “spread out” �Extends from the top of the troposphere (~12 km) to about 50 km above Earth’s surface. �Upper stratosphere in warmer than lower stratosphere �Contains the ozone layer �As altitude increases, temperature increases

Mesosphere �Meso means middle � 50 -80 km �There is a drop in temperature from the stratosphere �Is the middle layer �Protects the Earth’s surface from being hit by most meteoroids �Temperatures can reach -90 degrees Celsius

Thermosphere -The air is very thin, but very hot! -thermo means “heat” -Extends from 80 km above Earth’s surface into space -Divided into 2 layers: Ionosphere and Exosphere

Ionosphere and Exosphere Ionosphere: � Radio waves bounce off ions and go back to Earth’s surface � Brilliant light displays � Northern Hemisphere: Northern Lights Exosphere: � The outermost layer of the atmosphere � Exo means “out”