Transcript Earth`s Atmosphere - Verona Public Schools

Chapter Introduction
Lesson 1
Earth’s
Atmosphere
Lesson 2
Energy
Transfer in
the Atmosphere
Lesson 3
Air Currents
Lesson 4
Air Quality
Chapter Wrap-Up
How does Earth’s
atmosphere affect
life on Earth?
What do you think?
Before you begin, decide if you agree or
disagree with each of these statements.
As you view this presentation, see if you
change your mind about any of the
statements.
Do you agree or disagree?
1. Air is empty space.
2. Earth’s atmosphere is important to
living organisms.
3. All the energy from the Sun reaches
Earth’s surface.
4. Earth emits energy back into the
atmosphere.
Do you agree or disagree?
5. Uneven heating in different parts of the
atmosphere creates air circulation
patterns.
6. Warm air sinks and cold air rises.
7. If no humans lived on Earth, there
would be no air pollution.
8. Pollution levels in the air are not
measured or monitored.
Earth’s Atmosphere
• How did Earth’s atmosphere form?
• What is Earth’s atmosphere made of?
• What are the layers of the
atmosphere?
• How do air pressure and temperature
change as altitude increases?
Earth’s Atmosphere
• atmosphere
• stratosphere
• water vapor
• ozone layer
• troposphere
• ionosphere
Importance of Earth’s Atmosphere
• The atmosphere is a thin layer of gases
surrounding Earth.
• The atmosphere contains the oxygen
and water necessary for life on Earth.
• The atmosphere provides insulation
and helps keep temperatures on Earth
within a range in which living organisms
can survive.
Importance of Earth’s Atmosphere
(cont.)
The atmosphere helps protect living
organisms from some of the Sun’s
harmful rays and meteorites.
atmosphere
from Greek atmos, means
“vapor”; and Latin sphaera,
means “sphere”
Origins of Earth’s Atmosphere
• Erupting volcanoes emitting hot gases
from ancient Earth’s interior
surrounded the planet to form an
atmosphere.
• Ancient Earth’s atmosphere was
thought to be water vapor with a little
carbon dioxide and nitrogen, but not
enough oxygen to support life.
• Water vapor is water in gaseous form.
Origins of Earth’s Atmosphere (cont.)
• As Earth and its atmosphere cooled,
the water vapor condensed into liquid,
rain fell, and then evaporated from
Earth’s surface for thousands of years.
• Eventually water began to accumulate
on Earth’s surface, forming oceans.
• Earth’s first organisms could undergo
photosynthesis, which changed the
atmosphere.
Origins of Earth’s Atmosphere (cont.)
• The organisms removed CO2 from the
atmosphere and released oxygen into it.
• Eventually the levels of CO2 and oxygen
supported the development of other
organisms.
Origins of Earth’s Atmosphere (cont.)
How did Earth’s present
atmosphere form?
Composition of the Atmosphere
• Today’s atmosphere is mostly made up
of invisible gases, including nitrogen,
oxygen, and carbon dioxide.
• About 78 percent of the atmosphere is
nitrogen, and about 21 percent is
oxygen.
• The amounts of water vapor, carbon
dioxide, and ozone vary.
PhotoLink/Getty Images
Acids in the air are
formed when sulfur
dioxide and nitrous
oxide combine with
water vapor.
Composition of the Atmosphere (cont.)
• Many tiny solid particles, such as
pollen, dust, and salt, can enter the
atmosphere through natural processes.
• Solid particles of ash from volcanic
eruptions and exhaust soot from cars
are also present in the atmosphere.
C. Sherburne/PhotoLink/Getty Images
One way solid
particles enter the
atmosphere is from
volcanic eruptions.
Composition of the Atmosphere (cont.)
• The most common liquid particles in
the atmosphere are water droplets.
• Though microscopic in size, water
particles are visible when they form
clouds.
• Other atmospheric liquids include acids
that result when volcanoes erupt and
fossil fuels are burned.
Composition of the Atmosphere (cont.)
Acids in the air are formed when sulfur
dioxide and nitrous oxide combine with
water vapor.
What is Earth’s atmosphere
made of?
Layers of the
Atmosphere
The atmosphere has
several different layers,
each with its own unique
properties.
Layers of the Atmosphere (cont.)
• The atmospheric layer closest to
Earth’s surface is called the
troposphere.
• The troposphere extends from Earth’s
surface to altitudes between 8-15 km.
• The temperature of the troposphere
decreases as you move away from
Earth.
Layers of the Atmosphere (cont.)
• Sunlight passes through the
atmosphere, warms Earth’s surface,
and the warmth is radiated to the
troposphere, causing weather.
• The stratosphere is the atmospheric
layer directly above the troposphere.
Layers of the Atmosphere (cont.)
• The stratosphere extends from about
15 km to about 50 km above Earth’s
surface.
• The area of the stratosphere with a high
concentration of ozone is referred to as
the ozone layer.
• The presence of the ozone layer causes
the stratospheric temperatures to
increase with altitude.
Layers of the Atmosphere (cont.)
• Ozone has three oxygen atoms and
absorbs the Sun’s ultraviolet rays more
effectively than oxygen.
• Ozone protects Earth from ultraviolet
rays that can kill plants, animals, and
other organisms and cause skin cancer
in humans.
Layers of the Atmosphere (cont.)
• Combined, the mesosphere and
thermosphere are much thicker than
the troposphere and the stratosphere,
yet only 1 percent of the atmosphere’s
gas molecules are found in the
mesosphere and thermosphere.
• Most meteors burn up in the
mesosphere and thermosphere
instead of striking Earth.
• The ionosphere is a region within the
mesosphere and thermosphere
containing ions.
• The ionosphere’s ions reflect AM radio
waves transmitted at ground level.
Per Breiehagen/Getty Images
Auroras occur in
the ionosphere
when ions from
the Sun strike air
molecules,
causing them to
emit vivid colors of
light.
Layers of the Atmosphere (cont.)
• The exosphere is the atmospheric
layer farthest from Earth’s surface
where pressure and density are so low
that individual gas molecules rarely
strike one another.
• The molecules move at incredibly fast
speeds after absorbing the Sun’s
radiation and can escape the pull of
gravity and travel into space.
Layers of the Atmosphere (cont.)
What are the layers of the
atmosphere?
Air Pressure and Altitude
• Gravity pulls the
atmosphere toward Earth,
creating air pressure.
• At higher altitudes, the air
is less dense and air
pressure is lower.
• At lower altitudes, the air
is denser and air
pressure is higher.
Temperature and Altitude
• Temperature changes in different ways
as altitude increases in the different
layers of the atmosphere.
• In the troposphere, temperature
decreases as altitude increases.
• In the stratosphere, temperature
increases as altitude increases
because of the high concentration of
ozone.
Temperature and Altitude (cont.)
• In the mesosphere, as altitude
increases, temperature again
decreases.
• In the thermosphere and exosphere,
temperatures increase as altitude
increases.
Temperature and Altitude (cont.)
How does temperature
change as altitude increases?
PhotoLink/Getty Images
• Earth’s atmosphere consists of gases
that make life possible.
Per Breiehagen/Getty Images
• Layers of the
atmosphere
include the
troposphere, the
stratosphere, the
mesosphere, the
thermosphere,
and the
exosphere.
• The ozone layer is the area in the
stratosphere with a high concentration
of ozone.
Where did hot gases that created
Earth’s atmosphere come from?
A. the Sun
B. erupting volcanoes
C. the air
D. the ocean
What is about 78 percent of
Earth’s atmosphere made of?
A. nitrogen
B. oxygen
C. ozone
D. carbon dioxide
What is the region within the
mesosphere and thermosphere
containing ions?
A. exosphere
B. stratosphere
C. ozone layer
D. ionosphere
Do you agree or disagree?
1. Air is empty space.
2. Earth’s atmosphere is important to
living organisms.
Energy Transfer in the
Atmosphere
• How does energy transfer from the
Sun to Earth and the atmosphere?
• How are air circulation patterns within
the atmosphere created?
Energy Transfer in the
Atmosphere
• radiation
• stability
• conduction
• temperature
inversion
• convection
Energy from the Sun
• Radiation is the transfer of energy by
electromagnetic waves.
• Ninety-nine percent of the radiation
from the Sun consists of visible light,
ultraviolet light, and infrared radiation.
• The majority of sunlight is visible light
that passes through the atmosphere to
Earth’s surface, where it is converted
to heat.
Energy from the Sun (cont.)
• The wavelengths of ultraviolet (UV)
light and infrared radiation (IR) are just
beyond the range of visibility to human
eyes.
• UV light is harmful to human skin and
IR can be sensed as thermal energy or
warmth.
• As energy from the Sun is absorbed by
Earth, it is radiated back as IR.
Energy on Earth
As Sun’s radiation passes through the
atmosphere, some of it is absorbed and
some of it is reflected back into space.
reflect
Science Use to return light, heat,
sound, etc., after it strikes a surface
Common Use to think quietly and
calmly
Energy on Earth (cont.)
• Gases and particles in the atmosphere
absorb about 20 percent of incoming
solar radiation.
• Oxygen, ozone, and water vapor all
absorb incoming ultraviolet radiation.
• Water and carbon dioxide in the
troposphere absorb some infrared
radiation from the Sun.
Energy on Earth (cont.)
• About 30 percent of incoming radiation
is reflected into space.
• Bright surfaces, especially clouds,
reflect incoming radiation, and some is
reflected at Earth’s surface.
• Earth’s surface only receives and
absorbs about 50 percent of incoming
solar radiation.
Radiation Balance
• The amount of
radiation Earth receives
from the Sun is the
same as the amount
Earth radiates into the
atmosphere.
• This radiation balance
maintains an overall
temperature on Earth.
The Greenhouse Effect
• Some of the gases in the atmosphere,
called greenhouse gases, act like the
glass of a greenhouse, allowing sunlight
to pass through but preventing some of
Earth’s IR energy from escaping.
• When gases in Earth’s atmosphere
direct radiation back toward Earth’s
surface, this warms Earth’s atmosphere
more than normal, creating a heat
surplus.
The Greenhouse Effect (cont.)
The gases that trap IR best are water
vapor, carbon dioxide, and methane.
Thermal Energy Transfer
• Conduction occurs when the atmosphere
touches Earth.
• Conduction is the transfer of thermal
energy by collisions between particles of
matter.
• Thermal energy always moves from an
object with a higher temperature to an
object with a lower temperature.
Thermal Energy Transfer (cont.)
conduction
from Latin conducere, means “to
bring together”
Energy is
transferred through
conduction,
convection, and
radiation.
Thermal Energy Transfer (cont.)
• The transfer of thermal energy by the
movement of matter from one place to
another is called convection.
• As molecules of air close to Earth’s
surface are heated by conduction, they
spread apart, becoming less dense.
• Less dense air rises, transferring
thermal energy to higher altitudes.
Thermal Energy Transfer (cont.)
• Latent heat is exchanged when water
changes from one phase to another.
• Water is the only substance that can
exist as a solid, a liquid, and a gas at
the temperature ranges on Earth.
• Latent heat energy is transferred from
Earth’s surface to the atmosphere.
Water releases or absorbs heat energy
during phase changes.
Thermal Energy Transfer (cont.)
How does energy transfer
from the Sun to Earth and the
atmosphere?
Circulating Air
• Air is constantly moving and circulating.
• On a hot day, air that is heated becomes
less dense, creating a pressure
difference.
• Cool, denser air pushes the warm air out
of the way and the warm air is replaced
by the more dense air.
• The warm air is often pushed upward.
Circulating Air (cont.)
• Warmer, rising air is always
accompanied by cooler, sinking air.
• Circulating air affects weather and
climate around the world.
How are air circulation
patterns within the
atmosphere created?
Circulating Air (cont.)
• Stability describes whether circulating
air motions will be strong or weak.
• When air is unstable, circulating
motions are strong, and during stable
conditions, circulating motions are
weak.
• During unstable conditions, groundlevel air is much warmer than higheraltitude air.
Circulating Air (cont.)
• As warm air rises rapidly in the
atmosphere, it cools to form large, tall
clouds.
• Latent heat, released as water vapor,
changes from a gas to a liquid, adds to
the instability, and produces a
thunderstorm.
• A temperature inversion occurs in the
troposphere when temperature
increases as altitude increases.
Circulating Air (cont.)
During a temperature inversion, a layer
of cooler air is trapped by a layer of
warmer air above it.
• Not all radiation from the Sun reaches
Earth’s surface.
• Thermal energy
transfer in the
atmosphere occurs
through radiation,
conduction, and
convection.
• Temperature
inversions prevent
air from mixing and
can trap pollution
in the air close to
Earth’s surface.
The transfer of thermal energy by
the movement of matter from one
place to another is called what?
A. latent heat
B. conduction
C. convection
D. the greenhouse effect
When air is unstable, circulating
motions can usually be described
how?
A. strong
B. weak
C. absent
D. warm
Which is exchanged when water
changes from one phase to
another?
A. water vapor
B. convection
C. latent heat
D. cool air
Do you agree or disagree?
3. All of the energy from the Sun reaches
Earth’s surface.
4. Earth emits energy back into the
atmosphere.
Air Currents
• How does uneven heating of Earth’s
surface result in air movement?
• How are air currents on Earth affected
by Earth’s spin?
• What are the main wind belts on
Earth?
Air Currents
• wind
• jet stream
• trade winds
• sea breeze
• westerlies
• land breeze
• polar easterlies
Global Winds
• Wind patterns can be global or local.
• There are great wind belts that circle
the globe, and the energy that causes
this massive movement of air
originates at the Sun.
• Not all areas of Earth receive the same
amount of energy from the Sun.
Global Winds (cont.)
• The differences in pressure between
areas with low temperatures and high
temperatures create wind.
• Wind is the movement of air from
areas of high pressure to areas of low
pressure.
Global Winds (cont.)
How does uneven heating of
Earth’s surface result in air
movement?
Global Wind Belts
Three cells in
each
hemisphere
move air through
the atmosphere.
Global Wind Belts (cont.)
In the first cell, hot
air at the equator
moves to the top
of the troposphere
then moves
toward the poles
until it cools and
moves back to
Earth’s surface
near the 30°
latitude.
Global Wind Belts (cont.)
The second cell,
between 30° and
60° latitude, is
not a convection
cell because its
motion is driven
by the other two
cells.
Global Wind Belts (cont.)
The third cell, at the
highest latitudes, is
also a convection
cell. Air from the
poles moves
toward the equator
along Earth’s
surface, and
warmer air is
pushed upward by
the cooler air near
the 60° latitude.
Global Wind Belts (cont.)
• The three cells
exist in both the
Northern and
Southern
Hemispheres.
• Most of the air in
this convection
cell returns to
the equator near
Earth’s surface.
Global Wind Belts (cont.)
• The Coriolis effect occurs when the
rotation of Earth causes moving air and
water to move to the right in the
Northern Hemisphere and to the left in
the Southern Hemisphere.
• The contrast between high and low
pressure and the Coriolis effect creates
distinct wind patterns, called prevailing
winds.
Global Wind Belts (cont.)
How are air currents on Earth
affected by Earth’s spin?
Global Wind Belts (cont.)
• The trade winds are steady winds that
flow from east to west between 30°N
latitude and 30°S latitudes.
• The prevailing westerlies are steady
winds that flow from west to east
between latitudes 30°N and 60°N, and
30°S and 60°S.
Global Wind Belts (cont.)
The polar easterlies are cold winds that
blow from the east to the west near the
North Pole and the South Pole.
What are the main wind belts
on Earth?
Global Wind Belts (cont.)
• Located near the top of the
troposphere is a narrow band of high
winds called the jet stream.
• Jet streams influence weather as they
move cold air from the poles toward
the tropics and warm air from the
tropics toward the poles.
Local Winds
• Local winds occur whenever air
pressure is different from one location
to another.
• A sea breeze is wind that blows from
the sea to the land due to local
temperature and pressure differences.
• A land breeze is a wind that blows
from the land to the sea due to local
temperature and pressure differences.
Sea breezes and land breezes are
created as part of a large reversible
convection current.
• Wind is created by pressure
differences between one location
and another.
• Prevailing winds
in the global wind
belts are the trade
winds, the
westerlies, and the
polar easterlies.
• Sea breezes and land breezes are
examples of local winds.
What does the difference in pressure
between areas with low temperatures
and those with high temperatures
create?
A. wind
B. low pressure
C. stability
D. the Coriolis effect
What term refers to steady winds that
flow from east to west between 30°N
latitude and 30°S latitudes?
A. prevailing westerlies
B. jet streams
C. polar easterlies
D. trade winds
Which type of global winds move
cold air from the poles toward the
tropics and warm air from the
tropics toward the poles?
A. trade winds
B. jet streams
C. prevailing westerlies
D. polar easterlies
Do you agree or disagree?
5. Uneven heating in different parts of the
atmosphere creates air circulation
patterns.
6. Warm air sinks and cold air rises.
Air Quality
• How do humans impact air quality?
• Why do humans monitor air quality
standards?
Air Quality
• air pollution
• acid precipitation
• photochemical smog
• particulate matter
Sources of Air Pollution
• Point-source pollution is
pollution that comes from
an identifiable source such
as large factories.
• An example of natural
point-source pollution is an
erupting volcano.
C. Sherburne/PhotoLink/Getty Images
• The contamination of air by harmful
substances including gases and smoke is
called air pollution.
Sources of Air Pollution (cont.)
• Nonpoint-source pollution is pollution
that comes from a wide-spread area,
such as a large city.
• Some bacteria found in swamps and
marshes are examples of natural
sources of nonpoint-source pollution.
Sources of Air Pollution (cont.)
Compare point-source and
nonpoint-source pollution.
Causes and Effects of Air Pollution
• Acid precipitation occurs when sulfur
dioxide and nitrogen oxides combine
with moisture in the atmosphere and
create acids that fall as precipitation.
• Acid precipitation can be in the form of
rain, snow, and fog.
• It affects the chemistry of water in lakes
and rivers and can harm organisms living
in the water.
Causes and Effects of Air Pollution
(cont.)
• Natural sources of sulfur dioxide include
volcanoes and marshes.
• The most common sources of sulfur
dioxide and nitrogen oxides are
automobile exhausts and factory and
power plant smoke.
• Photochemical smog is air pollution
that forms from the interaction between
chemicals in the air and sunlight.
Causes and Effects of Air Pollution
(cont.)
• Smog forms when nitrogen dioxide,
released in gasoline engine exhaust,
reacts with sunlight.
• A series of chemical reactions
produces ozone and other compounds
that form smog.
• Ground-level ozone is the main
component of smog.
Causes and Effects of Air Pollution
(cont.)
How do humans impact air
quality?
Particulate Pollution
• Particulate matter is a mixture of dust,
acids, and other chemicals that can be
hazardous to human health.
• Particulate matter in the atmosphere
absorbs and scatters sunlight, which
can create haze.
Particulate Pollution (cont.)
particulate
from Latin particularis, means “of
a part”
Movement of Air Pollution
• Because air carries pollution with it,
some wind patterns cause more
pollution problems than others.
• Weak winds or no wind prevents
pollution from mixing with the
surrounding air, which can create high
pollution levels and dangerous
conditions.
At night, cool air sinks down the
mountain sides, trapping pollution in the
valley below.
Maintaining Healthful Air Quality
• Preserving the quality of Earth’s
atmosphere requires the cooperation of
government officials, scientists, and the
public.
• The Clean Air Act gives the U.S.
government the power to set air quality
standards which protect humans,
animals, crops, and buildings from the
harmful effects of air pollution.
Maintaining Healthful Air Quality (cont.)
Pollution levels are continuously
monitored by hundreds of instruments in
all major U.S. cities.
Air Quality Trends
• Air quality in U.S. cities has improved
over the last several decades.
• Ground-level ozone has not decreased
much, however, because as the
number of cars on the road increases,
air quality standards have not kept up
with all pollutant levels.
Pollution emissions have declined, even
though the population is increasing.
Air Quality Trends (cont.)
• The air inside homes and other
buildings can be as much as 50 times
more polluted than outdoor air and can
impact human health much more than
outdoor air quality.
• Indoor air pollution can come from
tobacco smoke, cleaning products,
pesticides, fireplaces, and radon—an
odorless gas given off by some soil
and rocks.
Air Quality Trends (cont.)
Why do humans monitor air
quality standards?
• Photochemical smog
contains ozone,
which can damage
tissues in plants and
animals.
C. Sherburne/PhotoLink/Getty Images
• Air pollution comes
from point sources,
such as factories, and
nonpoint sources,
such as automobiles.
What is pollution that comes from
a wide-spread area, such as a
large city?
A. smog
B. haze
C. nonpoint-source pollution
D. point-source pollution
Which is a mixture of dust, acids,
and other chemicals that can be
hazardous to human health?
A. photochemical smog
B. acid precipitation
C. sulfur dioxide
D. particulate matter
What describes what has happened
to air quality in U.S. cities over the
last several decades?
A. it has declined dramatically
B. it has declined slightly
C. it has improved
D. it has remained the same
Do you agree or disagree?
7. If no humans lived on Earth, there
would be no air pollution.
8. Pollution levels in the air are not
measured or monitored.
Key Concept Summary
Interactive Concept Map
Chapter Review
Standardized Test Practice
The gases in Earth’s
atmosphere, some of
which are needed by
organisms to survive,
affect Earth’s
temperature and the
transfer of thermal
energy to the
atmosphere.
Lesson 1: Earth’s Atmosphere
• Earth’s atmosphere formed as Earth cooled and
chemical and biological processes took place.
• The atmospheric layers are the
troposphere, the stratosphere,
the mesosphere, the
thermosphere, and the exosphere.
• Air pressure decreases as
altitude increases. Temperature
either increases or decreases as
altitude increases, depending on
the layer of atmosphere.
PhotoLink/Getty Images
• Earth’s atmosphere consists of nitrogen, oxygen, and
a small amount of other gases, such as CO2 and water
vapor.
Lesson 2: Energy Transfer in the
Atmosphere
• The Sun’s energy is
transferred to Earth’s
surface and the
atmosphere through
radiation, conduction,
convection, and latent
heat.
• Air circulation patterns
are created by
convection currents.
Lesson 3: Air Currents
• Uneven heating of Earth’s surface creates pressure
differences. Wind is the movement of air from areas
of high pressure to areas of low pressure.
• Air currents curve to the
right or to the left due to
the Coriolis effect.
• The main wind belts on
Earth are the trade winds,
the westerlies, and the
polar easterlies.
Lesson 4: Air Quality
• Some human activities
release pollution into the air.
C. Sherburne/PhotoLink/Getty Images
• Air quality standards are
monitored for the health of
organisms and to determine
if anti-pollution efforts are
successful.
Which is the atmospheric layer
directly above the troposphere?
A. stratosphere
B. ionosphere
C. exosphere
D. atmosphere
Which describes the air at higher
altitudes?
A. more dense
B. hot
C. layered
D. less dense
Which term refers to the transfer
of thermal energy by collisions
between particles of matter?
A. conduction
B. convection
C. radiation
D. circulation
The contamination of air by
harmful substances including
gases and smoke is called what?
A. photochemical smog
B. particulate matter
C. air pollution
D. ground-level ozone
Which describes air pollution that
forms from interaction between
chemicals in the air and sunlight?
A. acid rain
B. photochemical smog
C. particulate matter
D. nonpoint-source pollution
Which term refers to water in
gaseous form?
A. ozone
B. nitrogen
C. acid
D. water vapor
Which term describes the thin
layer of gases surrounding
Earth?
A. ozone layer
B. atmosphere
C. troposphere
D. stratosphere
The transfer of energy by
electromagnetic waves is called
what?
A. convection
B. conduction
C. radiation
D. circulation
Which term refers to the
movement of air from areas of high
pressure to areas of low pressure?
A. temperature inversion
B. stability
C. air pollution
D. wind
Which describes air pollution that
comes from an identifiable source
such as large factories?
A. point-source air pollution
B. nonpoint-source air pollution
C. photochemical smog
D. acid precipitation