Transcript 15.2 heating - Cobb Learning

Chap 15, Sect 2 (Atmospheric Heating)
Objectives: Please copy in your IAN!
1. Describe and show an example of
conduction, convection, and
radiation.
(glue and paste from blue tub)
2. Explain the relationship between the
greenhouse effect and global warming.
15.2 Atmospheric Heating
You are lying in a park with your eyes
closed, and you feel the warmth of the sun
on your face.
Did you ever realize that it takes a little
more than 8 minutes for the energy to
travel to your face from a star 149,000,000
km away?
Weather Factors
Sun’s energy travels to earth as
Electromagnetic waves.
Weather Factors
Scattering: Reflections of light in all
directions.
Why is the sky blue? (videoclip)
http://app.discoveryeducation.com/player/v
iew/assetGuid/6BFFC6FF-2E83-41D69B51-1653D5BE0386
Radiation
Ever feel the heat of the sun on your face
or the heat from standing by a campfire?
That is radiation.
It is the direct transfer of energy by
electromagnetic waves.
Conduction
Have you walked barefoot on the sand at
the beach and the sand burned your feet?
That is conduction.
It is the direct contact/ transfer of heat
from one substance to another.
Have you ever come
inside with wet shoes on
and your mother told you
to put them over the
heating vent to dry? How
does this dry them even
though the actual furnace
is in the attic? That is
convection.
The transfer of heat by
the movement of fluid or
air. Hot air rises, cold air
sinks.
Basement colder than
upstairs
Transfer of energy by
circulation.
Convection
Examples
Cooking on the stove-pot on burner
Hot air balloon rising
Fireplace warming a room
Curling iron on hair
Blow dryer on hair
Air from furnace heating the house
Bonfire Example
Radiation keeps you
away.
Smoke and flame are
carried away by
convection.
Ground beneath the
fire gets hot by
conduction.
How is Earth heated?
Light/heat from the sun RADIATES
through the atmosphere, hits the Earth
where it is absorbed.
This heats the air above it by
CONDUCTION.
This heat rises up to the greenhouse
gases where it is trapped, cools, sinks and
heats at the surface again.CONVECTION.
Think about it: Why does 70 degrees in
Spring feel colder than 70 degrees in Fall?
Weather Factors
In Summary:
Energy from the sun is the driving force behind
the water cycle, which contributes to create
Earth’s weather.
Radiation is transfer by electromagnetic waves.
Thermal conduction is energy transfer by direct
contact. Convection is energy transfer by
circulation.
The greenhouse effect is Earth’s natural
heating process. Increasing levels of
greenhouse gases could cause global warming.
Greenhouse Effect
These gases absorb
the heat and act as a
“blanket” to keep
Earth warm.
Some greenhouse
gases: water,
methane, carbon
dioxide.
Runaway Greenhouse Effect
Runaway Greenhouse Effect
http://www.epa.gov/climatechange/kids/ind
ex.html
http://www.bing.com/videos/search?q=bill+
nye+global+warming&qs=n&form=QBVR&
pq=bill+nye+global+warming&sc=823&sp=1&sk=#view=detail&mid=B709AB17CAFE
760B2441B709AB17CAFE760B2441
The Greenhouse
Global Warming
VS.
Effect
 gases (CO2 and
 an increase in
water vapor) absorb
average global
thermal energy and
temperatures
radiate it back to
Earth
 an increase in
 a process that
greenhouse gases
reminds us of an
in the atmosphere
actual greenhouse
Global Warming Causes
Natural:
Volcanoes
Solar flares
Flatulence
Cycle
Orbit
Snow
Poop
Cows
Forest fires
Methane release in the arctic tundra
Manmade Causes:
Industry
Deforestation
Cars
Fossil fuels
Hairspray
Wars
Blow dryers
Heat/AC
Hot water
Arms race
Nuclear waste
Coal burning
Electricity
Define and Design
Explain 2 different points of view for the
Greenhouse Effect. Due =1/16 & 1/18
This is a lab grade: 4 labs = 30%
Other upcoming dates?
– Ch. 15 Quist 1 = 2/24
– Ch.16/17 Quest 2 = 3/6
– Tech Term Final = 4/2
Debate Format:
•You will be placed into groups of 4 to compare notes
and
information.
• You will then be told which side you are arguing.
•The floor will be opened for speaking 1 at a time.
•You may “respectfully disagree” with each other once
the speaker has finished.
•Remember, if you get really loud, it is a sign of
weakness.
Debate Tips:
•Be polite and courteous.
•Listen attentively
•Be respectful and supportive of peers.
•Avoid inappropriate noises.
•Speak only when recognized by the moderator.
•Allow others to express their opinions; do not
monopolize the debate.
•Use grammatically correct language.
•Speak clearly, slowly, and loud enough to be
heard by the audience.
•Speak with passion and excitement.