Layers of the Atmosphere Atmosphere The atmosphere is

Layers of the Atmosphere

Atmosphere • The atmosphere is the blanket of gases that surrounds the Earth • Composition: ▫ 78% Nitrogen ▫ 21% Oxygen ▫ 1% other gases such as Argon, Carbon Dioxide, Water Vapor and Ozone

Atmosphere • The atmosphere is divided up into 4 different layers: ▫ ▫ Troposphere Stratosphere Mesosphere Thermosphere

Troposphere(approx. 0 – 10 km) • Contains most of the mass of the atmosphere • Most weather takes place in the troposphere • Temperature decreases (15 C (57 F) -40 C/ (-40 F)) • Has the greatest air density • The top of the troposphere is called the tropopause

Stratosphere (approx. 10 -50 km) • Air density decreases • Airplanes fly in this layer (to avoid weather) • Temperature increases with increasing altitude ( -40 C (-40 F) -3 C (27 F)) • Contains the Ozone Layer • Stratopause

Ozone • Ozone (O 3) – A gas in the stratosphere that blocks UV radiation ▫ CFC’s (a form of pollution) can deplete ozone

Mesosphere (approx. 50 – 90 km) • Temperature decreases (-3 C (27 F) -90 C (-130 F)) • Meteors from outer space burn up in this layer • The Mesopause is the coldest part of the atmosphere

Thermosphere (approx. 90 km – 500 km) • Has the greatest temperature range ( -90 C (-130 F) 2000 C (3632 F)) ▫ Because gases are spaced so far apart ▫ Has low air density • Contains the Ionosphere – Region where gases are ionized by the suns energy

The Exosphere ( approx. 500 km – Outer Space) • The upper portion of the Thermosphere where gases escape into outer space ▫ Has the lowest air density • Contains lighter gases such as hydrogen and helium