Atmosphere

I. Layers of the atmosphereA. Layers of the Atmosphere

1. Troposphere 2. Stratosphere

3. Mesosphere4. Thermosphere*

* split into the Ionosphere and the Exosphere 1

2

Stratopause

3

Mesopause

4

Tropopause

AtmosphereB. Description of Atmosphere Layers

1.Tropospherea. Tropo means “turning” or changingb. extends from the earth’s surface from 12 kilometers in altitudec. weather changes

d. COOLING TREND - temperature drops/cools as you go up

2. Stratospherea. extends from the Tropopause to an altitude of 50 kilometers (32

kilometers thick)b. strong, steady windsc. few weather changes

d. WARMING TREND - warms as you go up

e. contains the ozone layer – oxygen molecules that absorb ultraviolet radiation

Atmosphere3. Mesosphere (Middle Layer)

a. rises from the Stratopause to 80 kilometers (30 kilometers thick)

b. COOLING TREND - temperature falls/drops as you go upc. Protects Earth from meteors – they burn up hered. Coldest part of the atmosphere

• Thermosphere (Outermost layer)

a. rises from Mesopause to 300+ kilometersb. WARMING TREND - temperature rises as you go up

(hottest layer)c. Splits into the Ionosphere (80-550 km) and the

exosphere (above 550 km)d. Meteors Enter here

AtmosphereGases in the Atmosphere (DRY AIR)

1. Nitrogen 78%2. Oxygen 21%3. Argon 0.9%4. Carbon Dioxide 0.03%5. All Others 0.01%

nitrogernoxygenargonCarbon dioxideall otheres

AtmosphereII. Air QualityA.Sources of Pollutants – some occur naturally, but

many are the results of human activity 1. Natural Sources – forest fires, soil erosion, dust

storms, wind carries mold and pollen, and volcanic eruptions

2. Human Activities – most pollutants occur from the burning of fossil fuels (cars and factories), farming, and construction

B. Smog and Acid Rain – caused by burning of fossil fuelsC. Improving Air Quality – state and federal governments

have passed laws to reduce air pollution