Transcript atmosphere notes

The
Atmosphere
“Vapor Globe/Ball”
Composition
78% Nitrogen
21% Oxygen
1% Other (Argon, Carbon Dioxide,
Water Vapor, other gases)
Air Pressure
 Measure of force with which air
molecules
push on a surface
 Gravity pulls air molecules toward the
Earth
 The closer to the surface you are, the
more air pressure
– The lower the altitude, the higher the air
pressure
Layers
 Troposphere, Stratosphere,
Mesosphere,
Thermosphere
 Based on temperature changes as
altitude
increases
Layers
Troposphere
 Lowest, but densest layer
 90% of the total mass
 Contains all of Earth’s life, carbon
dioxide,
water, clouds, pollution,
weather
Stratosphere
 Air is very thin with little moisture
 Contains ozone layer
– Ozone has three oxygen atoms
– The oxygen we breathe has two oxygen
atoms
– Ozone absorbs harmful UV radiation from
the Sun
Mesosphere
 Coldest layer
 “Middle” layer
 Large wind storms
Thermospher
e
 Gases absorb solar radiation
Eventually blends into space
(exosphere)
High temperature, but feels cold
– Air molecules move very fast
– Air molecules are so far apart, they do not
transfer energy
Ionosphere
 Upper mesosphere and lower
thermosphere
 Nitrogen and oxygen atoms that absorb
solar
radiation
 Carries AM radio waves
 Aurora Borealis (northern lights)
Energy
 Radiation from the Sun
 Visible light is changed into heat energy
 Energy is moved around with radiation,
conduction, and
convection
Energy
Greenhouse
Effect
 Atmosphere traps thermal energy near
the
Earth
 Keeps Earth livable
 Greenhouse gases are the only gases
that trap thermal energy
– Carbon dioxide is a greenhouse gas
– Too much CO2 can cause global warming
– Average global temperature would
Winds
 Caused by pressure differences
 Uneven heating of the earth causes
pressure
differences
– Equator has warmer, less dense air
– Poles have colder, more dense air
– Colder air is denser, so it sinks causing high
pressure
 Air moves from high pressure to low
Types of
Winds
 Trade Winds
– 30° N or 30° S to the equator
– Weak winds
Westerlies
– 30°- 60° in northern and southern
hemispheres
Polar Easterlies
– 60° to poles in both hemispheres
Types of
Winds
 Jet Streams
– Found in upper troposphere and lower
stratosphere
– Not regular patterns
– Affects pilots
 Local Winds
– Wind that is affected by local geography
Local Winds
Pollution
 Primary Pollutants- directly from human
or
natural activity
– car exhaust, volcanic ash, pollen, dust
 Secondary Pollutant- pollutants from
primary pollutants reacting with other
chemicals
– Smog is from car exhaust and ozone
– Acid rain is from sulfur or nitrogen and water