Transcript Earth`s Atmosphere

Earth’s
Atmosphere
Chapter 15
Characteristics of the
Atmosphere
Thermosphere
Mesosphere
Stratosphere
Troposphere
• You should have all of
your notes from 15.1 on
this graphic organizer.

More INFO… via VIDEO
Auroras
• Northern and Southern
Lights …WHY???
• Nitrogen and Oxygen
absorb energy from the
sun
• Increase in temperature
• Electrically charge gas
particles = ions
• The ions radiate energy
as shimmering lights
More INFO… via VIDEO
Atmospheric Heating
•
Earth and the Atmosphere are warmed
by energy from the sun!
• Heat moves from areas of warmth to
areas of cold
Three ways heat can be transferred:
1. Radiation
2. Conduction
3. Convection
More Info… Via Video 
Radiation
• Transfers energy through
infrared waves (sun or fire)
• Can move through EMPTY space
• No direct contact between heat source
and an object.
• Example: bonfire warming your face
Heat given off
from a light bulb is
also a form of
radiation…
Heat from a
bonfire is an
example of
radiation…
Conduction
• Transfers heat through DIRECT
CONTACT of particles (solid to solid)
• Example: bare feet on hot pavement
A spoon
heating up
in a pot of
soup!
The pan gets HOT
because it is
touching the HOT
burner on the
stove!
Convection
• Transfer of heat through the movement of
FLUIDS and GASES
• Example: soup heating inside a pot
• Movement is created by differences in
DENSITY
– Hot things = less dense = rise to the top
– Cold things = more dense = fall to the bottom
Convection
Example: Lava Lamp
Cools off!
= more dense
= fall to the
bottom
Hot!
= less dense
= rise to the
top
Review… Via Video 
Energy in the Atmosphere
Electromagnetic Waves
• Electromagnetic waves are energy from the sun
that can travel through space
• Remember….
• The transfer of energy by electromagnetic
waves is called RADIATION.
Electromagnetic Spectrum
The electromagnetic spectrum
organizes the radiation from the sun
from the longest wavelength to the
shortest wavelength.
The Greenhouse Effect
• Earth’s atmosphere
gases act as a
“blanket” and hold in
the heat from the
infrared radiation.
• The greenhouse effect
helps Earth maintain a
comfortable livable
temperature, even at
night.
Heat Transfer (Review!!)
1. Radiation – Heat that you feel from a
heat source. EX: sun or fire (infrared
radiation)
2. Conduction – Direct transfer of heat from
one object touching another object
3. Convection – Transfer of heat by the
movement of a fluid or air (convection
current)
Radiation, conduction, and convection work
together to heat the troposphere.
Heat Transfer (Review examples!!)
AIR COOLS OFF
(Drops back Down)
Which type of heat transfer?
1. Your feet get hot when walking barefoot
across hot pavement.
2. You can feel the heat from the hot iron
without touching it.
3. In winter, the second floor of your house
is warmer than the first floor.
4. You are lying on the beach and the sun
makes your skin tingle.
5. You burn your finger when you
accidentally touch the hot stove.
Which type of heat transfer?
1. Your feet get hot when walking barefoot
across hot pavement. Conduction
2. You can feel the heat from the hot iron
without touching it. Radiation
3. In winter, the second floor of your house
is warmer than the first floor. Convection
4. You are lying on the beach and the sun
makes your skin tingle. Radiation
5. You burn your finger when you
accidentally touch the hot stove.
Conduction
Hot Air Rises…
But how does the ground get
hotter??? …
It is farther from the sun!
Air in the atmosphere acts as a fluid (water vapor). The sun's
radiation strikes the ground = warming the rocks/ground.
As the ground’s temperature rises due to conduction, heat
energy is released into the atmosphere, forming a “bubble”
of air which is warmer than the surrounding air. This
“bubble” of air rises into the atmosphere. As it rises, the air
in the “bubble” cools and becomes more dense. The
movement of the air creates wind. Convection currents are
responsible for many weather patterns in the troposphere.
Convection
Currents!
Winds 15.3
What causes winds?
• Differences in air pressure
• More of a difference in pressure = faster winds
Lots of difference
Air Rises @ Equator
Air Sinks @ Poles
• You know…
– Warm air rises = less dense
– Cool air sinks = more dense
• Now understand…
–Warm air = less dense
= low pressure
–Cool air = more dense
= high pressure
Info… via Video… 
Global Winds
• Created by unequal heating of Earth’s surface.
Global Winds…
cont…
• The movement of air
between the equator
and the poles
produces global
winds.
• Coriolis effect produces
patterns of air circulation
called global winds.
Global Wind Belts
• Major global wind systems:
• Polar easterlies, westerlies, and trade winds.
Doldrums
• Where the trade winds meet around the equator
• Very little wind because the warm air rising =
low pressure
Horse Latitudes
• High pressure areas… 300N and 300S
• Very week winds
Jet Streams
• Bands of high speed winds
• Upper troposphere and
lower stratosphere
• Blow from west to east at
speeds of 200-400 km/hr.
• Help airplanes save fuel
and time when traveling
east.
Local Winds
Have you ever flown a kite at the beach on a hot summer day? Even if there is
no wind inland, there may be a cool breeze blowing in from the water toward
the beach. This breeze is an example of local winds!
• Local winds are winds that blow over short
distances.
• They are caused by unequal heating of Earth’s
surface within a small area.
• Types:
– sea breezes and land breezes
– Mountain breeze and valley breeze
Sea Breeze (Morning)
Land heats up faster than water. Hot air over land
rises (Low Pressure), cool air over water falls
(High Pressure). Winds move from the water
(High Pressure) to the land (Low Pressure).
Land Breeze (Evening)
Land cools off faster than water. Cool air over land
falls (High Pressure), warm air over water rises
(Low Pressure). Winds move from the land (High
Pressure) to the water (Low Pressure).
Valley Breeze (Day)
During the day the sun warms the air slopes,
creating a valley breeze…
at nightfall, the air along the mountain slopes
cools…
Mountain Breeze (Night)
This cool air moves down the slopes into the
valley, producing a mountain breeze!
Wind Vane
Measuring Wind
• Winds are described by their
direction and speed.
• Wind direction is determined with a
wind vane – points in the direction
the wind is moving!
• Wind speed is measured with an
anemometer.
• The increased cooling that a wind
can cause is called the wind chill
factor.
Anemometer – The cups
catch the wind, turning
faster when the wind blows
faster.