Atmosphere Notes: p. 1
Complete the comparison chart
Origin of the Atmosphere
How was it
Formed?
Current theory says atmosphere has changed over
Gases
What happened
to change it?
time:
1st atmosphere: would have formed with the
1st
planet about 4.5 billion years ago; made of H, He;
these light elements were soon scattered by solar
winds
2nd atmosphere: would have formed from
2nd
volcanic gases (H2O, CO2, SO2, NOX) these same
gasses as are emitted by volcanoes today)
3rd atmosphere: would have formed as
photosynthesis developed, releasing O 2 as a by-
3rd
product and absorbing excess CO2
Atmosphere: the layer made of a combination of
Draw a pie chart of the percentage of gases in the atmosphere. Make
a key to identify the gases
gases that surrounds the earth
Air: a combination of gases mixed together in the
lower part of the atmosphere
Nitrogen
Nitrogen 78%
Oxygen
Oxygen 21%
Argon
Argon 1%
Carbon Dioxide
CO2: 0.03%
water vapor: variable (think desert vs. rainforest)
Match the Characteristic of the Atmosphere to the Instrument
that measures it.
Atmosphere Notes: p. 2
Structure of the Atmosphere: 5 layers, based on
Sketch the Temperature Profile and Label the layers of the
Atmosphere
patterns of changes in temperature
1. Troposphere: home sweet home
almost all weather occurs here
most of the atmospheric gasses, especially
the heavier ones, are concentrated here
temperature decreases as altitude
increases (gets colder as you go higher)
2. Stratosphere
Temperature rises in this layer because
ozone (03) layer absorbs 99% of UV rays-the sun’s energy is turned into heat
UV rays are harmful, cancer-causing
ozone layer is thinning due to CFC’s and
other pollutants, so more UV gets through
high altitude steady winds (i.e. jet stream)
occur here; jet planes often fly here
3. Mesosphere
Temperature drops, as expected
dark blue color
4. Thermosphere
Atmosphere is very thin; very few molecules
temperature rises again because the very
few gas molecules have essentially
unlimited energy to absorb
space shuttle flies here
black –too few molecules to bend sunlight
Ionosphere: a part of thermosphere; it is
layer of ionized gases that influence radio
reception; aurora borealis occurs here
5. Exosphere
very few air molecules
blends in to outer space
Temperature Profile of the Atmosphere
Atmosphere Notes p.3
The Atmosphere in Motion
Air Pressure: weight of air per unit area
•
Measured w/barometer
•
units millibars (mb) or inches of mercury
•
cold, more dense air moving downwards is
high pressure
air always moves outward away
Show the movement of air around high and low
pressure systems
H
L
from high pressure
•
warm, less dense air moving upwards is low
pressure
air always inward towards low
pressure
•
so, air blowing sideways, called wind,
always moves from high pressure towards
low pressure
Local Winds (100 km or less)
Show air
circulation, including relative temperatures and
pressures
Draw a land breeze and a sea breeze.
Sea breeze: during daytime, warm air rises over
land, cool ocean air moves in to replace it
Land breeze: at night, land cools faster than
water, so warm air rises over sea, making low
land
pressure, xo wind blows from land to sea
Coriolis Effect: bending of winds due to earth’s
rotation
Called an apparent motion, it occurs when air
flowing out of hi pressure turns clockwise in N
hemisphere ( and counterclockwise in the Southern
hemisphere)
land
Atmosphere Notes: p. 4
Planetary Wind Belts: caused by unequal heating
of the atmosphere
The Doldrums : Hot air rises at equator, creating a
low pressure zone with very few winds
because it is a low pressure, the air is
moving up, not sideways
low pressure brings lots of rain
also called the Intertropical Convergence
Zone (ITCZ)
The Trade Winds: strong winds move into the low
pressure of the Doldrums from above and
below the equator
some of the strongest, steadiest winds on
the planet
The Horse Latitudes high pressure zones of little
winds created when the hot air that rose at the
equator cools and starts to sink at 300 N/S of the
equator
also called the sub Tropical High
high pressure brings dry air
legend says this is where they threw the
horses overboard because of lack of water
Prevailing Westerlies: from 300 to 600 N/S,
winds move out of the high pressure zone created
by the Horse Latitudes
Most of the USA is in the prevailing
Westerlies.
This is why our weather patterns tend to
move from the west to the east
Subpolar Low: low pressure area of converging
air rising upwards at 60
Polar Easterlies: weak winds blowing from 60 090C degrees N/S; sometimes called the Polar Front
Draw and Label the Doldrums, The Tradewinds(2).
the Polar Easterlies (2), Horse Latitudes (2)
Subpolar Lows (2), Prevailing Westerlies (2)
Atmosphere Notes: p. 5
Energy Transfer in the Atmosphere
Label the Parts of the Heat Balance (Heat Budget)
Insolation: IN COming SOLar RadiATION
It is all of the energy received from the sun.
30% reflected back to space
70% absorbed
o
20% by clouds, 50% by surface
The heat balance is maintained b/c some of the
energy is re-radiated from surface as heat
Temperature varies by latitude and season, b/c
The sun’s rays are most direct at the equator; and
spread out near poles
Greenhouse effect: warming of atmosphere as
heat is absorbed by CO2, H20
Shortwave solar energy enters atmosphere
some insolation is absorbed by clouds but
most is absorbed by the earth’s surface
most of this energy is re-radiated back
outwards form the ground as long wave
heat energy, which is then absorbed by
greenhouse gases (CO2, H20, methane,
others) in the atmosphere
the greenhouse gases keep the earth’s
atmosphere at a livable temperature
Burning fossil fuels puts lots of additional
CO2 in atmosphere; this may contribute to
global warming
Draw the Greenhouse Effect. LABEL diagram as
necessary to describe the process.
Atmosphere Notes: p. 6
Ozone
•
Oxygen usually occurs in the diatomic state
(O2) but ozone is the triatomic state(03)
What are the differences between the
greenhouse effect and the ozone layer?
•
Occurs naturally in stratosphere
•
Ozone absorbs 99% of ultraviolet radiation,
which causes cancers and genetic
Greenhouse
Effect
Chemical
Formula
mutations
•
ozone layer is thinning because of CFC’s
(chlorofluorcarbons) break apart ozone
Layer of the
Atmosphere
It occurs in
molecule
•
the ozone hole, where the greatest thinning
has occurred, is over Antartica
•
CFC’s used in aerosols, coolants,
Styrofoam
•
Positive
Effect
In the troposphere, ozone is a pollutant; it is
Pollutant that
Effects it
the part of smog ht can make your eyes
water
Negative
Effect
Ozone
Layer