Atmospheric Zones, 2 Fonts, 2 Sizes, Image #3

Atmospheric Zones

The Earth’s atmosphere is 78.08 percent nitrogen, 20 95 percent oxygen, 0 93 percent argon, and 0.03 percent carbon dioxide.

Layer

Height (above Earth’s surface)

Troposphere 5 miles at poles; 7 miles at mid-latitudes; 10 miles at Equator

Temperature What do we know? Drops 3.6 °F every 1,000 ft up; minimum reaches -70°F

Stratosphere 30 miles Stable at around -58°F

Contains 75% of the total mass of the atmosphere. This is where life and almost all of our weather is found. The top of the troposphere is called the tropopause

Contains 24% of the total mass of the atmosphere. At the bottom of the stratrosphere is the ozone layer

Mesosphere 50 miles

Decreases from 20°F at base to -166°F, before rising again at top Meteors burn up in this zone to give “shooting stars;” together with the thermosphere, this layer contains many ionized particles, and they are collectively termed the ionosphere--this is the layer off which radio signals bounce to allow radio telecommunications

Thermosphere 400 miles Exophere: togehter with thermosphere, makes up “outer atmosphere”

Variable; can reach 441°F Gets so hot because the thin atmosphere reabsorbs a lot of radiation that bounces back from the lower layers Up to 40,000 miles Fall to near zero

The atmospheric density at 6,000 miles is the same as outer space. Above this height, it is only the “atmosphere” in the sense that the Earth’s gravitational and magnetic field exert some influence. The exosphere contains the magnetosphere, where the aurorae appear