Layers of the Atmosphere

How are they broken up? Temperature Make up (more dense air is in lower layers ) What occurs

Troposphere Meaning: “Tropo” means turning or changing Depth: 16 km above the equator and thinner at the poles at 9km  Shallowest layer Contains dust, water vapor and 75% of all gases Temperature decreases with increasing height  Every 1km increase in altitude, the air drops 6.5 ˚ C  Stops dropping around -60˚C All weather occurs here

Stratosphere Meaning: “Strato” means layer or spread out Depth: extends from Troposphere to 50 km above earth Houses the ozone layer (protection from UV ) Temperatures: Lower portion -50 ˚C; upper portion are O˚C  Why is the upper portion of the Stratosphere warmer???  The Ozone Layer absorbs energy from the sun (heat)

The Ozone Layer UV or electrical discharge can separates O 2. O 2 recombines into O 3 (ozone) in the stratosphere. This layer shields the Earth from much of the harmful UV.

The Ozone and Chlorofluorocarbons

The Hole in the Ozone Responsible for 1.3 million cases of skin cancer die from skin cancer each year in U.S. Montreal Protocol is an international treaty signed in 1987 to eliminate the production and consumption of ozone-depleting chemicals (CFC). Areas may correct themselves with reduction in CFC

Mesosphere Meaning: “Meso” means middle Depth: begins at 50km above earth and extends to 80-85km Temperature: -90˚C (coldest temps) Protection from foreign objects  Trail of hot, glowing gases from the meteor

Thermosphere Meaning: “Thermo” means heat Depth: 80km above earth extending into space Temperature: extremely HOT: 1,800 ˚C  Sun strikes this layer first  Oxygen and Nitrogen molecules convert energy into heat Air is very thin % as dense as air in Troposphere  1 cubic meter of matter at sea level would expand to 100,000 cubic meters Divided into two layers

Thermosphere’s Ionosphere Energy from the sun causes gas molecules in the Ionosphere to become electrically charged—called Ions Lower layer of Thermosphere Depth: 85km-400km above earth Auroras are caused by particles from the sun that enter the ionosphere near the poles. These particles strike atoms in the ionosphere—causing them to glow!

Thermosphere’s Exosphere “Exo” means outer From 400km for thousands of km