EVSC10001 Lecture Notes - Lecture 14: Ozone Layer, Thermosphere
11 Jun 2018
School
Department
Course
Professor
What is air?
78.1% nitrogen
20.9% oxygen
Argon, water, CO2, ozone
Comparing planets
Venus
Mostly CO2
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GHG stores sun energy -> high temps
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Super high pressure
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Earth
Balanced greenhouse effect
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Clouds of water, polar ice caps
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Mars
Weak greenhouse effect -> cold
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Low pressure
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Surface air pressure
Density + pressure decrease exponentially with height
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Atmospheric layers
Troposphere
Decreasing temp with altitude
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Effect on weather
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Surface heated by solar radiation
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Convective - mixes air throughout layer
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All atmospheric WATER VAPOUR
Water depends on temp (more for higher temp)
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Rising (warm) air causes condensation -> clouds + releasing latent heat
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Thunderstorm tops = TROPOPAUSE
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Stratosphere
Temp increase with altitude
Absorption of solar UV by oxygen and ozone
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Ozone layer
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Stable - no convection + water vapour
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Mesosphere
Temp decrease with altitude
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Thermosphere
Surface temp determined by
Incoming solar radiation + infrared radiation
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Hotter temps when sun is more directly overhead
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Ocean composition
Mixture of fresh water + salts
Cl-, Na+, Mg+, SO42-
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Salinity: measure of all dissolved salts
Modifies density
Higher salinity = higher density
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Modifies freezing temp
Surface, sea water freezes at -2
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Affected by net rainfall minus evaporation + net freezing minus elting
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Temp modifies density - warmer = less dense
More saline near tropics
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Higher evaporation
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Cold - more melting of ice
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Sea water is almost incompressible
Pressure increases linearly with depth
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Deep ocean well mixed and stratified
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Atmosphere and ocean
Wednesday, 6 June 2018
3:43 pm
