Download Topic: Earth`s Atmosphere Essential Question: What are the

Topic: Earth’s Atmosphere
Essential Question: What are the characteristics of the layers of the atmosphere?
Atmospheric Composition
 air is made up of gases: nitrogen, oxygen and particles such as dust carried by the wind, salt
picked up by the wind from ocean spray, water droplets, and ice crystals.
Permanent atmospheric gases
 99% of the atmospheric gases is composed of -78% nitrogen N2 and 21% Oxygen O2
 remaining 1% is argon A2, carbon dioxide CO2 water vapor H2O and other trace gases.
 nitrogen and oxygen are constantly being recycled between atmosphere, living organisms,
oceans, and Earth’s crust.
 CO2 and water vapor can vary in amounts in atmosphere from place to place.
 CO2 has increased in atmosphere because of burning of fossil fuels.
ATMOSPHERIC LAYERS
 atmosphere
contains 5 layers
 TROPOSHPERE
 layer closest to
the Earth weather
occurs here
 Air temperatures
decrease as
altitude increases.
Temperatures
stop decreasing at
tropopause. This
area can be
anywhere from
5.5 miles to about
10 miles above
the Earth’s
surface.
 temps can be as
low as -76 o F
STRATOSPHERE
 layer is above tropopause
 ozone layer is in stratosphere
 Below ozone layer, temps stay constant with altitude.
 From the bottom of the ozone layer going up, temps increase with altitude.
 This is because ozone molecules absorb ultraviolet radiation from sun.
 At stratopause, temps stop increasing with altitude.
 stratopause is about 30 miles above Earth’s surface.
 About 99.9 % of mass of atmosphere is below the stratopause.
 Airplanes fly in this layer because air is still here. No turbulence.
MESOSPHERE
 above Stratosphere.
 It is about 31-62 miles above Earth’s surface.
 Temps decrease with altitude.
 Very little solar radiation is absorbed in this layer.
 At top of this layer, temps stop decreasing with altitude.
 This area called mesopause.
THERMOSPHERE
 layer is about 62-311 miles above the Earth’s surface.
 Very low density of air here cause temps to rise.
 Temps here can be more than 1832o F.
 ionosphere is in this layer and contains electrically charged particles.
 This is layer where space shuttles fly and where aurora lights are seen.
EXOSPHERE
 layer is about 311-6214 miles above Earth’s surface.
 This is outer most layer of atmosphere.
 This is where outer space begins.
 This is where satellites are located.
Summary