Transcript Weather 1 - Edublogs

Atmosphere, Energy Transfer,
and Air Movement
Mr. Ross, 7th Science
I. The Atmosphere
A. Importance of the Atmosphere
1. Atmosphere- a thin layer of air
forming a protective layer
around the planet
2. Keeps the temperature in a
range that supports life
3. It protects life from the Sun’s
harmful rays
B. Makeup of the Atmosphere
1. Mixture of solids, liquids, and
gases. Extends from the
crust
to outer space.
2. Early Atmosphere was created by
volcano eruptions.
a) was mostly Nitrogen and
CO2
b) Small organisms gave ate
CO2 and released Oxygen
c) An ozone layer (O3)formed
to protect organisms from
harmful sun rays
d) Plants evolved and changed
more CO2 into O2
3. Gases in the Atmosphere
a) 78%= Nitrogen (N2)
b) 21%= Oxygen (O2)
c) 0.93%=Argon
0.03%=Carbon Dioxide (CO2)
d) 0.04%= Other gases
(Methane, Hydrogen,
Krypton, Xenon, Ozone, ect.)
e) Water Vapor can also make
up about 4% of the
atmosphere
4. Solids and Liquids in the Atmosphere
a) Solid particles include
dust, pollen, salt (from
ocean spray)
b) Liquids include water
droplets and other
liquids
C. Layers of the Atmosphere
1. Troposphere- Lowest layer
of the atmosphere; where
weather happens
a) contains 99% of water
vapor and 75% of
atmospheric gases
b) Extends from earth to
10 km high
Troposphere!
2. Stratosphere- Extends from 10 km to 50 km;
contains the Ozone layer
a) Ozone layer protects us from
harmful UV rays
3. Mesosphere-Extends from 50 km to 85 km;
place where shooting stars occur
4. Thermosphere- thickest layer, extends from 85
km to 500 km.
a) contains the Ionosphereelectrically charged particles
that bounce radio waves over
long distances
5. Exosphere- the area beyond 500 km, the
beginning of outer space
OZONE LAYER
Which Layer does it happen in?
A severe Thunderstorm
Shooting Stars
Satellites orbit Earth
Ozone layer absorbs UV rays
Place where AM radio waves reflect back to earth
Which Layer does it happen in?
A severe Thunderstorm : Troposphere
Shooting Stars: Mesosphere
Satellites orbit Earth: Exosphere
Ozone layer absorbs UV rays: Stratosphere
Place where AM radio waves reflect back to earth:
Thermosphere
D. Temperature/Pressure in Atmosphere
1. Pressure- force exerted on an
area
2. Pressure in the atmosphere
increases as you move closer
towards earth
a) Like a pile of football
players—the player on
the bottom of the pile
feels the most weight.
b)The player on top feels the
least weight
3. At sea level, the air pressure is about
15 pounds per square inch. SO, on your
head right now, you feel about 1200
pounds of pressure on your head from
AIR!
4. Sun is the source of energy for earth; but this
energy must pass thru atmosphere
a) Troposphere is warmed by the earth
(which is warmed by sun); every
kilometer you climb, the temperature
drops 6.5° C
b) Ozone absorbs sun energy, making the
upper stratosphere warm up
c) Mesosphere temperatures drop with
altitude (like the Troposphere)
d) The thermosphere and exosphere are
the first to receive the sun’s rays, so the
temperature is very high
E. Ozone
1. Ozone layer is between 19 and 48
km; made of molecules of
oxygen (O3)
2. Absorbs most of the Ultraviolet
Rays from the sun (Harmful rays)
a) UV rays can cause
mutations, especially skin
cancer
3. Ozone is destroyed by CFCs, a
chemical that was used in aerosol sprays,
air conditioners, foam and refrigerators.
4. There was a hole in the Ozone layer
near Antarctica because of CFCs
5. CFCs were banned, and the Ozone
hole has started to close up again
II. Energy Transfer in the Atmosphere
A. Energy from the sun
1. Energy on earth comes
mostly from the SUN!!!!
a) Sun energy goes to
plants, plant energy goes
to animals, and so on.
2. Energy from the sun can be….
a) Reflected by the atmosphere
(6%), clouds (25%), or earth’s
surface (4%)
b) Absorbed by the atmosphere
(15%) or by Earth’s surface (50%)
3. Life exists on earth because it holds
just the right amount of energy and
reflects just the right amount. This keeps
the temperature at a good level
B. Heat
1. Heat is energy that flows from
an object of higher temperature to
an object of lower temperature.
2. Heat is transferred by Radiation,
conduction, and convection
3. Radiation- energy transferred in the
form of rays or waves
a) radiant energy from the sun
warms your face!
b) Sun’s heating of water (to cause
evaporation) is radiation
4. Conduction- transfer of energy when
molecules bump into each other
a) hot sand warms your feet by
conduction
b) Air near earth’s surface is heated
by conduction
c) water vapor in the air loses
energy to the atmosphere by
conduction
5. Convection- transfer of heat by the
flow of material.
a) Cool air sinks and pushes hot air
out of the way, creating a
convection current
Radiation, Conduction, or Convection
You feel the heat from a light bulb
You feel the heat from touching a hot pot
The roof of your mouth burns when you bite
into a piece of cheese pizza
Radiation, Conduction, or Convection
Your feet are colder than your head in a hot
shower
Your hands are cold when you grab a cold Pop
can
A ceiling fan that is turned on cools the whole
room
III. Air Movement
A. Forming Wind
1. Wind is the movement of
air from an area of higher
pressure to lower pressure.
2. Uneven heating of the earth (since
earth is curved) causes some parts of
earth to be heated more than others
a) The equator receives direct sun
rays, the north and south poles
receive slanted rays, and so they
receive less heat
b) This causes different areas of
density and pressure
3. Winds are named by where they
come from
a) Winds that come from the west
are Westerlies (even though they
move towards the east)
What is the Wind’s name?
Wind Blowing east

Wind Blowing west 
Wind Blowing Southeast
Wind Blowing Northeast
Westerly Wind
Easterly wind
Northwest wind
Southwest
wind
4. Cold, HIGH pressure air comes
from the poles
5. Warm, LOW pressure air comes
from the equator
6. Coriolis Effect-rotation of the
earth causes moving air and water
to turn right when north of the
equator, and left when south of the
equator
B. Surface Winds
1. Doldrums- near the equator,
even heating causes no wind
(no pressure difference),
and lots of rain (hot air rises,
cools, and then precipitates)
2. Westerlies- near 30° to 60°
North and South, earth’s
rotation deflects air and
moves wind from west to
east 
3. Trade Winds- Coriolis effect
deflects air from east to west 
from 0° to 30° N or S
4. Polar Easterlies- air moves from
east to west  near the North and
South poles
C. Winds in the Troposphere
1. Jet Streams-narrow belts of
strong winds; blow near the
top of the troposphere
2. Polar Jet Stream forms a boundary
of cold air between cold, dry polar air
in the north, and warm, moist air to
the south
a) Polar Jet stream moves faster
in the Winter, because the
difference in temperature/
pressure is greater
b) Saves planes fuel when traveling
west to east by flying in the jet stream
c) Planes traveling east to west avoid
the jet stream to save more fuel
D. Local Wind Systems
1. Smaller wind systems affect
local weather
a) Land and sea breezes
occur near large bodies of
water (oceans, lakes)
2. Sea breeze- created by land near
water during the day by convection
currents
a) solar radiation warms the land
more than the water
b)Air over land is heated by
conduction
c)warm air rises over land, and
cooler (high pressure) air from
the water moves underneath
3. Land Breeze- movement of air from
land towards the sea at night
a) At night, the air over land
cools faster, the high pressure
air is over land
b) Low pressure (warm) air over
water rises, gets pushed out of
the way by high pressure air
from the land
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