Download Chapter 15 Characteristics of the Earth*s Atmosphere

Chapter 15
Characteristics of the Earth’s
Atmosphere
Standard S6E3.b: The relationship between
the atmosphere and the water cycle
Standard S6E4.b: The effects of unequal
heating on weather patterns
Section 1: pp. 448-453
EQ: What is the composition of Earth’s
atmosphere?
• Atmosphere
• Mixture of gases that
surrounds the planet or
moon
• Nitrogen—78% from
decomposition of dead
organisms
• Oxygen—21% released
from plants
• Other gases—1% from
carbon dioxide, argon,
water vapor, etc.
EQ: Why does air pressure change
with altitude?
• Air Pressure
• The measure of how
much force air
molecules push down
on a surface
• Decreases with altitude
& is less dense
EQ: How does air temp. change with
atmospheric conditions?
• Result of composition
of the atmosphere
• Some gases absorb
more solar energy &
cause an increase in
temp.
EQ: What are the 5 layers of the
atmosphere?
• Thermosphere
• Upper most layer
• Molecules are extremely
far apart
• Hottest layer
• Mesophere
• Coldest layer
• Stratosphere
• Temp. increases at the
top of the layer
• Contains the ozone layer
that protects Earth from
harmful UV solar rays
• Troposphre
• The layer we live in
• Most dense layer with
90% of Earth’s mass
• Where weather occurs
• May be polluted
Summary
• Explain why hot air rises. How does this
concept relate to the density of air in the
upper levels of the atmosphere?
EQ: How is Earth heated?
• Radiation
• Transfer of energy as
electromagnetic waves
from the sun
• Earth receives only a
tiny fraction , but it’s
enough to influence
weather
• Conduction
• Transfer of heat by direct
contact, by touching
• The hot object gives heat
to the cooler object.
• Convection:
• Transfer of thermal
energy by the circulation
or movement of a liquid
or gas
• Hot air rises, cold air sinks
• Earth is covered with
convection zones
EQ: What is the relationship between
the green house effect and global
warming?
• Greenhouse Effect
• Radiation Balance
• Gases in the atmosphere,
like water vapor and CO2
absorb earth’s heat &
then send it back to Earth
• Acts like a blanket &
keeps the heat in
• Equal amounts of heat
enter Earth and leave
Earth
• Global warming
• Gradual increase in the
average global
temperature due too
increased CO levels
• Result of burning fossil
fuels, deforestation
• Effects plant and animal
habitats
2
Summary
• How is the greenhouse effect related to the
water cycle?
• What might happen to the water cycle as
greenhouse gases increase?
Section 3 pp. 458-463
EQ: What is the relationship between
air pressure and wind direction?
• Wind
• Caused by differences in
air pressure
• The greater the
difference, the faster
the wind blows
• Air Rises @ the Equator
• Warm ,less dense air has
low pressure, rises &
flows to the poles
• Air Sinks @ the Poles
• Cold, more dense air sinks
& flows to the equator
• Pressure Belts
• Caused by uneven
heating of the Earth every
30 degrees latitude at
convection cells
• Coriolis Effect
• Global winds appear to
curve due to Earth’s
rotation
• Global Winds
• Caused by convection
cells & Coriolis Effect
• Polar Easterlies
• Westerlies
• Trade Winds
• Jet Stream
• Narrow belt of strong
winds that blow in the
upper troposphere &
lower stratosphere
• Max. speed = 400km/h
• Affects the movement
of storms
• Brings colder air to us if
it dips south
EQ: What causes local winds?
• Local winds
• Move short distances
• Can blow from any
direction
• Local geographic
features can create
wind
• Sea Breeze
• Land Breeze
• During the day, the cooler
air over the ocean forms
high pressure
• Blows over the land &
pushes the warmer land
air up
• At night, cool land air
blows over the warmer
ocean air that is pushed
up
• Valley Breeze
• During the day, warm
air rises up to the top of
the mountain slope
• Mountain Breeze
• At night, cold air sinks in
to the valley
Summary
• Draw a graphic organizer to explain sea and
land breezes and valley and mountain breezes.
Label and use arrows to indicate direction.