Transcript 15.2 Atmospheric Heating

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?
Radiation
Sun on your face
standing by campfire
direct transfer of energy by
electromagnetic waves through space.
Conduction
Bare feet burned by hot sand
direct transfer of heat from one substance
to another through direct contact.
Convection
Basement colder than
upstairs
transfer of heat by the
movement of fluid or air.
Hot air rises, cold air
sinks.
Transfer of energy by
circulation.
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
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.
Weather Factors
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 transfer of heat from one
substance to another.
Convection
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.
Bonfire Example
Radiation keeps you
away.
Smoke and flame are
carried away by
convection.
Ground beneath the
fire gets hot by
conduction.
How earth is heated.
Light/heat from the sun radiates through the
atmosphere, hits the Earth where it is absorbed.
This heats the land and air above it by
conduction.
This heat rises up to the greenhouse gases
where it is trapped, it 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?
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/glo
bal_warming_version2.html
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
Draw, color, label and explain your own
picture of the Greenhouse Effect.
Egg in
bottle
Fire warmed up air inside, molecules escaped
before egg was put on top and when egg
wobbled.
When fire went out, temperature cooled,
molecules condensed, changing air pressure.
Since the pressure outside bottle was higher, the
higher pressure tried to get in the bottle.
Since the egg is squeezable, it got pushed into
the bottle by the air.