Introduction #2
B
The Earth’s Atmosphere
The thickness of our Atmosphere
Mt. Logan
5959 m
19551 ft
Mt. Everest
8850 m
29035 ft
Another look at the
make-up of our
atmosphere.
Just an interesting slide for now - more on
clouds later in the course.
When particles become charged in the Ionosphere
we get the Aurora Borealis
Let’s briefly take about some of the
simple characteristics of our
•Atmosphere:
•Temperature,
•Pressure and
•Wind.
The different
Temperature
scales
Remember the
shape of the
earth has
something to do
with
Temperature and
Location.
Temperature
Range is the
Hottest - Coldest
What do you
notice?
This is called a
normal lapse rate
In the Troposphere (where we live) it is normal for
the temperature to decrease with altitude.
04_30b.jpg
This is called an
inverted lapse rate
In a temperature inversion - the temperature rises with
altitude.
This is more typical - At first temp. decreases then you reach a
section where the temp. increases with altitude. The air
eventually reaches an altitude where it begins to cool again.
Let’s say the ground is cool and then a warm air mass moves in
above the ground - an inversion is created. See the next slide
for a negative effect.
Inversions
can be
harmful
The hot air from the stacks rises till it meets are with
similar temperature - then it just flattens out.
What happens to our atmosphere when you add this
to it?
Air Pollution
Look at the pictures closely and you can see
the areas with pollution and the areas
without - good use of Remote Sensing.
The Urban Environment
The pollution and dust created by a city can create a
Greenhouse effect called the Urban Heat Island.
Urban Heat Island
A simple
Barometer to
measure
Pressure
Air Pressure Readings
Pressure like
Temperature
decreases with
altitude.
The relationship between Temperature and
Pressure.
As the thermometers next to the balloons indicate (a, b), rising air
cools adiabatically due to expansion and (c, d) descending air warms
adiabatically due to compression.
Warm at the bottom - Cold at the top!
How are atmosphere
protects us!
The Ozone
and it’s ability
to block
harmful ultraviolet rays has
been in the
news in the
last few years.
The Ozone hole!
Finally and quickly - Wind is created when there is
a difference between pressure. Air travels from a
high pressure to a low pressure. But it is not that
simple! The pressure gradient is the difference in
pressure and determined the force of the wind.
How light winds
and strong
winds are
created.
Wind Vane and
Anemometer
What does this
measure?
Wind power!
Because the earth
rotates the wind
curves (coriolis
effect). Much more
on this later. The
red arrows
represent the air
movement - but the
air over a low
pressure rises while
the air over a high
pressure descends.
Air Masses,
which have
specific Pressure
and Temperature
characteristics
are what effects
our climate.
Wow,
Temperature,
pressure, wind it’s all connected!
The End