Download Air Composition/Layers

Air Composition/Layers
Composition
 First atmosphere was a lot
of nitrogen, carbon
dioxide, and very little
oxygen
 Plants completing photo
synthesis create more free
oxygen
 Today, 72% nitrogen, 26%
oxygen, and then
Layers
 Troposphere contains us, all
the weather and winds, and
most air on Earth
 Stratosphere contains ozone
and warmer temperatures
because of reflected solar
radiation
 Mesosphere has cooler
temperatures and less air
 Thermosphere continues up
to space
Layers Diagram
Air Pressure/Humidity/Temperatures
Temperatures/Pressure
 Temperatures change in
different layers because of
properties and amount of
air in the atmosphere
(cools in higher altitudes in
troposphere)
 Pressure simply decreases
as you increase in altitude
Humidity
 Since all water vapor on
Earth is located in the
troposphere, it decreases
as you increase in altitude
 Higher relative humidity
mean more moist air and
less means drier air
Solar Energy in the Atmosphere
 Earth’s tilted axis creates
different seasons in the
hemispheres because of
the angle of the solar rays
 Land and water heat and
release heat at different
rates
 A convective current will
occur when warmed, moist
air near the surface will
rise, and cools and releases
moisture as precipitation,
sinking back towards the
surface to warm up again
Convection Cell/Current
Difference between Weather
and Climate
Weather
Climate
 Short term, day to day or
 Long term, year to year or
weekly
 Conditions are usually told
for a smaller region
 Changes faster than
climate
over hundreds of years
 Conditions will cover a
large area, sometimes for a
whole country
 Changes are usually slower
and larger scale
Air Masses and Fronts
Air Masses
Fronts
 Share temperature and
 Warm Front Warmer
moisture conditions all
over the global, picking up
different conditions as they
move all over the globe
 Combine to form fronts
temperatures and long
periods of moderate
precipitation
 Cold Front Cooler
temperatures with shorter
periods of precipitation
that are more intense
Thermal Inversion
 When a warm air rises
and cold becomes
trapped underneath it,
trapping any pollution
that was rising and trying
to escape to the higher
atmospheric layers
 Create concentrated
layer of pollution closer
to the surface,
endangering human
health
Large Scale Circulation Currents
Solar radiation is most
intense at the equator
where the warm air will
rise and then sink at
about 30° latitude
Less solar radiation will
happen at the higher
latitudes and the cool
air will sink
Other latitudes will
have rising cooler air
that will sink in other
latitudes when it grows
even colder
Global Wind Patterns
 Hadley Cells where there the air warms at the
equator, cools and descends at about 30º North
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and South of the equator
 Ferrel and polar cells Lifts air and creates
precipitation at 60º North and South, and
descends around 30º and the Polar Regions
Conditions for following latitudes
> Equator (0º) wetter climates
> 30º arid and warmer climate
> 60º cooler and wetter climates
> Poles (90º) arid and cold climates