Transcript The Earths Atmoshphere

The Earth's Atmosphere
Key Topic: 8 key items that make up
our atmosphere

Troposphere

Stratosphere

Mesosphere

Thermosphere

Exosphere

Atmosphere pressure

Gases

Solids & Liquids
TROPOSPHERE

Lowest layer to Earth

Most weather occurs here

70-80% water vapor

Extends 11-20 Km or 7-12 miles

Where all life on the planet exists
Stratosphere

2nd lower layer to the Earth

Little moisture—no clouds



No convection due to air temperatures
slowly decreasing with altitude
Temperature averages -60o C or -76o F
Airplanes fly here because of no violent
cloud formations/storms
Mesosphere

1st of the Upper layers of Earth's Atmosphere

Starts about 53 miles above the ground

Temperature is around -90oC or -130oF


Hard to study as weather balloons &
airplanes fly in the stratosphere and rockets
fly above it
Meteors burn up in this layer
Thermosphere




Tempature climbs sharply in 2nd Upper layer
range from about 500° C (932° F) to 2,000° C
(3,632° F) or higher due to Suns' activity
Air is so dense that this is where we
consider “outer space” to begin
Most of the X-ray & U-V rays from the Sun
are absorbed here (these are very harmful to
us)
Exosphere

Very high up, the Earth's atmosphere
becomes very thin. The region where atoms
and molecules escape into space.

No weather

No breathable air

5500 miles from Earth's surface
Atmosphere Pressure
The pressure is high at the surface where air is
slowly descending - much to slowly to feel.
And, this is going on over a large area,
maybe a few hundred square miles. As air
descends, it warms, which inhibits the
formation of clouds. This is why high
pressure is generally - but not quite always associated with good weather.
How do we simplify this????
Atmosphere Pressure, Cont.




Remember the mantle of the Earth? Same
thing is occurring in the air...
Warm air rises, becomes cool
As cool air lowers, it warms again to form
clouds.
The different layers of the Atmosphere aides
in the warming/cooling process
Atmosphere Pressure, Cont.


A "high" is an area where the air's pressure
is higher than the pressure of the
surrounding air.
A "low' is where the air pressure is lower.
Meteorologists don't have any particular
number that divides high from low pressure;
it's the relative differences that count.
2 serious problems to Atmosphere
Pressure

Greenhouse effect
The earth is surrounded by a blanket of gases. This
blanket traps energy in the atmosphere, much the
same way as glass traps heat inside a greenhouse.
This results in an build up of energy, and the
overall warming of the atmosphere. The
greenhouse effect is a natural process which made
life on Earth possible

ENHANCED effect which is caused by the increase
of greenhouse gases from human sources
2 serious problems, cont.

Ozone Damage
The ozone is a small layer in the atmosphere
that protects us from harmful UV rays
but human waste products and contaminants
have damaged that layer over time.
Gases
21%
OXYGEN (O2)
78%
NITROGEN (N2)
0.04%
CARBON DIOXIDE
(CO2)
~0.9%
ARGON (Ar)
Solids & Liquids



Small particles of dust & debris, smaller by
1000x a grain of salt
Water Vapor is the most common form of
liquid found in the atmosphere
Gathers from the surface to form clouds that
come back to Earth as rain
AKA=The water cycle!!