EARTH’S ATMOSPHERE

Warner Bros.
Movie
Trailers:
Twister
What gases are in
our atmosphere?
Nitrogen
Oxygen
Argon
Bottom Graph is only the tiny
sliver from top graph!!!!
Carbon Dioxide
Neon
Helium
Methane
Krypton
Hydrogen
Exosphere
Exosphere

Highest layer of
atmosphere, 640 km to
10000 km
 Boarder between
atmosphere and outer
space
 Hydrogen (H) and Helium
(He) are the primary
molecules present
 Some satellites orbit here.
Thermosphere

Height from 85 km to 640 km
– Lower boundary called
“Mesopause”

Name means “Heat Sphere”
– Temperatures can reach over
1000 o C
– Few molecules present absorb the
strong solar energy and heat up
– Even though temperature is very
hot, it would feel COLD to us
due to the low molecule density!

Temperature increases with
height
 International Space Station
orbits here in Low Earth Orbit
(LEO)
 Auroras occur here!
Ionosphere

Inside Thermosphere
 Height from 80 km to
550 km
 Helps radio and
television signals travel
– Before satellites, this was
the only way to
communicate over very
long distances without a
wire connecting two places

Full of electrically
charged particles (Ions)
Mesosphere

Height 50 km to 85 km
– Upper boundary called
“Mesopause”
– Lower boundary called
“Stratopause”

Coldest layer
– Temperature drops with
height
– Can be up to minus 100
degrees C

Most meteors entering the
atmosphere burn up here
Stratosphere

Height from 18 km to 50
km
– Upper boundary called
“Stratopause”
– Lower boundary called
“Tropopause”

Contains the Ozone Layer
 Temperature increases
with altitude
– Due to absorption of solar
radiation by Ozone Layer
Troposphere

Lowest layer
– Surface to 18 km
– Upper boundary called
“Tropopause”

Temperature decreases
with height
 75% of the total mass of
the atmosphere is here!
 Weather happens here!
 All non-aquatic life lives
here!
What is the source of
all heat and weather
on the Earth?
The SUN is the
source of all
heat & weather
on Earth.
3 Types of Energy
CONVECTION
Transfer of heat energy
through motion of
liquid or gas caused by
differences in density.
CONDUCTION
Transfer of heat energy
through collisions of
the molecules of a
substance.
RADIATION
Transfer of energy through space in the form of
electromagnetic waves.
Three (3) types of Energy
Conduction
Convection
Radiation
•Energy from the sun radiates through space
to heat the atmosphere and Earth’s surface by
conduction & convection
Energy (Heat) Transfer
Energy transfer among sun, atmosphere &
Earth’s surface produces weather

If more energy comes in than leaves,
Earth’s temperature will increase
 If more energy leaves than comes in,
Earth’s temperature will decrease
Heat transfer
 Heat in the Atmosphere
 Energy from the sun heats Earth’s atmosphere and surface.
 Heat moves through the atmosphere in three different
ways: radiation, conduction, and convection.
Earth’s surface
absorbs 51%
Radiate 15%
to atmosphere
Radiate 6%
to space
Atmosphere
absorbs 19%
Conduction & convection 7%
to atmosphere
30% reflected
into space
(albedo)
Evaporation 23%
to atmosphere
Solar energy
100%
Energy transfer between Earth’s surface and
the atmosphere creates the WEATHER
Insolation: incoming solar radiation
click here for a youtube video
Humans can Change the atmosphere
 Human Influence on the Atmosphere
 The carbon dioxide content of the atmosphere has increased
due to human activities, primarily the burning of fossil fuels:
coal, gasoline, and natural gas.
Humans can change the atmosphere
 Human Impact on the Atmosphere
 Biologic activity, including human activity, may
influence global temperature and climate.
 Air pollution – harmful particles caused by volcanoes,
forest fires, and human activity.
 Acid Rain – sulfur dioxide and nitrogen react with
water vapor create an acid rain that kills fish and
forests, and damages structures of marble and
limestone.
 Smog – nitrogen oxides and hydrocarbons (auto
exhaust) that, when triggered by solar radiation,
create harmful ground-level ozone.
Human impact on the atmosphere
UV Rays
UV Rays
 Human Impact on the Atmosphere
 Ozone Depletion – a hole in the protective ozone
layer created by chlorofluorocarbons (CFCs)
Ozone Creation
CFC kill O3
Human impact on the atmosphere
 Human Impact on the Atmosphere
 Global Warming – due to increase in greenhouse gases.



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Rising sea levels
Global Warming = Climate Collapse
Melting polar caps
Stronger storms
More storms and
droughts
 Relocation of crop areas
INSTRUMENTATION
TO
MONITOR
THE ATMOSPHERE
Air Temperature
Wind Speed
Humidity
Wind Direction
Air Pressure
Instrumentation
Thermometer
measures
temperature
Barometer
measures
air pressure
Psychrometer measures
humidity
Air Pressure

A barometer
measures air
pressure

Air pressure at sea
level is 760mm
barometer
Air Pressure
Changes because of…



Elevation
Temperature
Humidity
Elevation
As elevation increases, the pressure
decreases since there is less air around you
Denver, CO: 835mb
Sea Level: 1013mb
Temperature
A warm air
mass has low
pressure & rises
A cold air
mass has high
pressure & sinks
As temperature increases, pressure
decreases because the molecules are
further apart
Humidity
As humidity increases, pressure decreases
because water molecules are less massive
than air.
Humid air rises
& has low
pressure
Dry air sinks &
has high pressure
Air pressure
Isobar: a line that
joins points with the
same air pressure;
lines closer together
mean steeper pressure
gradient
Explain the relationship between air
pressure and
1.
2.
3.
Temperature
Elevation
Humidity
Winds
Air flows from high pressure to low
pressure, forming winds
Winds
Air over land cools faster & heats faster
than air over water
 sea breeze: when winds blow inland from
the ocean, because a warm low pressure
area is over the land
 land breeze: when winds blow off the land
to the ocean because a warm low pressure
area is over the ocean
Sea Breeze
Warm low
pressure zone
over the land
Cool high
pressure zone
over the sea
Air rises
Air sinks
Wind blows from the sea to the land,
filling in the gap left by rising warm air.
Land Breeze
Cool high
pressure zone
over the land
Warm low
pressure zone
over the sea
Air sinks
Air rises
Wind blows from the land to the sea,
filling in the gap left by rising warm air.
Draw and Label a Sea Breeze
Include—
1. Air packets
2. Areas of High and Low Pressure
3. Direction of the wind on the shore
Draw and Label a Land Breeze
Include—
1. Air packets
2. Areas of High and Low Pressure
3. Direction of the wind on the shore
Wind
Anemometer:
instrument to
measure wind
speed
Factors Affecting Winds

Coriolis effect
 Jet stream
 Global Wind patterns
Coriolis Effect
Coriolis effect: the tendency of an object
moving freely over Earth’s surface to curve
away from its path of travel, caused by E’s
rotation
Northern Hemisphere
Curve to the right
Southern Hemisphere
Curve to the left
Coriolis Effect -North
Winds around a
high pressure zone
circle clockwise
Winds around a
low pressure zone
circle counterclockwise
Youtube animation at 1:29 minutes
What is the direction of a High
Pressure system in the
Northern Hemisphere?
What is the direction of a Low
Pressure system in the
Northern Hemisphere?
Jet Stream
a band of swiftly moving wind, moving east
from west, at the top of the troposphere,
unaffected by friction
Global
Wind
Patterns
Global Wind Patterns

Intertropical convergence zone (ITCZ): lowpressure zone near equator caused by warm,
rising air
 trade winds: 5-20° latitudes - warm & steady
winds
 sub-tropical highs: 20-35° latitudes - air usually
sinks - very dry w/ little wind - deserts
 polar highs: high pressure regions near the poles
(sinking air) - very dry
Horse Latitudes
30-35 degrees N/S
Seasonal Winds
Summer
 Land hotter than ocean,
so blows moist air inland
 Summer monsoon: winds &
rain
Winter
 Ocean hotter than land,
so blows dry air to sea
 Winter monsoon: winds &
no rain
Temperature maps

Colored to show temperatures
 Often have ISOTHERMS - lines that connect
places with the same temperature
Santa Ana
Winds
Seasonal Monsoon
Winds of
Bangladesh
Monsoons of
Bangladesh
(NASA)
Earth’s Early Atmosphere
-Cyanobacteria: were
blue-green algae thought
to be one of the earliest
forms of life on Earth
appearing about 3.5 billion
years ago
-These organisms were
partially responsible for
altering the Earth’s
atmosphere increasing the
oxygen content
Bibliography
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omjet.jpg
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