Download Air pressure - Riverdale Middle School

Air Pressure
1. When air pressure increases, the liquid in a
mercury barometer rises
2. An aneroid barometer does not use liquid
3. Air pressure is greater at what point B
4. Altitude is greater at what point A
5. Density of the air is greatest at point B
6. Air pressure – the result of the weight of a column
of air pushing down on an area
7. Barometer – any instrument that measures air
pressure
8. Density – the amount of mass in a given volume of
air
9. Mercury barometer – an instrument that measures
air pressure using liquid mercury
10. Aneroid barometer – an instrument that measures
air pressure without using a liquid
11. Altitude – the distance above sea level, elevation
Notes: Earth’s Atmosphere
A.
B.
C.
Atmosphere – the dome of solids, liquids, and gases that
surround the Earth
The atmosphere has many jobs:
1.
absorbs energy from the sun
2.
recycles water
3.
works to provide a moderate climate
4.
protects us from high energy radiation
5.
protects us from the vacuum of space (a vacuum is
a place with NO AIR)
Gases in the Atmosphere
1.
Nitrogen (N) – the most abundant; makes up 78%
2.
Oxygen (O) – second most abundant; makes up
21%
3.
Other gases – making up 1% (Argon, Carbon
Dioxide, Water vapor and other trace gases)
D.
E.
Solids and liquids in the atmosphere:
1.
dust, salt and pollen
2.
little droplets of liquid water other than what is in
the clouds
Layers of the Atmosphere
1.
Lower levels
a.
Troposphere –
1.
lowest layer
2.
Earth’s weather occurs here
3.
contains 90% of the gases that make
up the atmosphere
4.
extends to about 10km above Earth’s
surface
b.
2.
Stratosphere –
1.
from about 10km-50km above Earth’s
surface
2.
upper stratosphere is warmer
because of the ozone layer
a.
Ozone layer – layer of oxygen
gas (O3)
b.
Absorbs the ultraviolet
radiation form the sun
c.
energy is converted to heat
and warms the air
Upper Layers of the Atmosphere
a.
Mesosphere –
1.
middle layer
2.
outermost level in mesosphere is the
coldest (-90C)
3.
If you have seen a shooting star, you
are seeing a meteor burn up in the
mesosphere
b.
Thermosphere –
1.
80km above Earth to outer space
2.
no definite end to Earth’s atmosphere, the gas
and air molecules are spread so far apart that
they just blend into outer space
3.
air is thin and very hot (1,800C) because energy
from the sun hits this layer first
a.
The Ionosphere –
1.)
lowest layer of the thermosphere
2.)
energy from the sun causes
particles in the ionosphere to
become electrically charged (ions)
3.)
radio waves bounce off the
charged particles and travel back to
Earth
b.
The Exosphere –
1.)
“exo-“ means outer
2.)
outer layer of the atmosphere
3.)
satellites orbit in the exosphere