2. When air can’t expand, it cools.
When it gets compressed, it warms.
Temperature changes that occur
when heat isn’t added or subtracted
are called adiabic temperature
changes.
Although the air will continue to
cool after condensation starts, the
latenet heat that gets released works
against the adiabatic cooling process.
http://iopscience.iop.org/1367-
2630/10/6/065001/fulltext/
3. When elevated terrains, like http://ocw.usu.edu/Forest__Range__a
nd_Wildlife_Sciences/Wildland_Fire_M
mountains, take position as anagement_and_Planning/Unit_7__At
barrier to air mospheric_Stability_and_Instability_3.
flow, orographic lifting of air html
occurs.
As air makes its way up a
mountain slope, adiabatic
cooling often generates
precipitation and clouds.
Many of the places most
rainy on Earth are located
on these windward
mountain slopes.
4. http://www.geo.hunter.cuny.edu
/~tbw/wc.notes/4.moisture.atm.
stability/frontal_wedging.htm
In central North America, heaps of cold air and warm
air collide. This produces a front.
The cooler, denser air acts as a barrier over the warmer
less dense air as it rises.
Weather-producing fronts are related to specific storm
systems called middle-latitude cyclones.
5. When air in the lower
atmosphere flows together,
the result is lifting
(convergence)
If air flows in from more than
one direction, it must go
somewhere.
http://en.wikipedia.org/ Because it cannot go down, it
wiki/File:Oceanic- goes up, leading to adiabatic
oceanic_convergence_Fig
21oceanocean.gif cooling and a possibility of
clouds forming.
6. On warm summer days,
uneven heating of the
Earth’s surface can cause
pockets of air to be
warmed more than the
air that is surrounding it.
The method that
produces increasing
thermals is localized
convection lifting.
When warm air parcels http://rst.gsfc.nasa.gov/Sect14/Sect1
of air ascend above the 4_1c.html
condensation level,
clouds form.
7. http://deved.meted.ucar.ed
u/marine/mbl/print.htm
If a quantity of air was required to rise, its temperature
would drop because of expansion.
If this volume of air was cooler than the surrounding
environment, it would be denser, and if permitted to do
so, it would drop to its original location.
8. Air must be saturated
for condensation to
occur.
Saturation occurs most
commonly when the air
is cooled to its dew
http://keep3.sjfc.edu/students/kes00898/ point. It occurs less
e-
port/condensation%20page%20for%20uni often when water vapor
t.html
is added to the air.
9. Clouds are classified
based on their height
and form.
Cirrus= a curl of hair
(clouds are high, white
and thin)
Cumulus= a pile (clouds http://eo.ucar.edu/webweat
consist of rounded her/cloud3.html
individual could
masses)
10. http://mynasadata.larc.nasa.gov/g
lossary.php?&letter=H
There are 3 types of high clouds- Cirrus, Cirrostratus and
Cirrocumulus.
All high clouds are thin and white. They often are made of ice
crystals.
This is because of the low temperatures and small amounts of
water vapor that are at high altitudes.
11. Clouds about 2,000 to 6,000
meters high have the prefix alto
as part of their name.
Altocumulus clouds are made up
of rounded masses that vary
from cirrocumulus clouds in that
altocumulus clouds are larger
https://www.meted.ucar.edu/sign_ and denser.
in.php?go_back_to=http%253A%25
2F%252Fwww.meted.ucar.edu%25 Altostratus clouds create a
2Ffire%252Fs290%252Funit6%252F uniform white to grayish sheet
print_2.htm##
that covers the sky with the sun
or moon, looking like a bright
spot.
12. http://www.free-online-private-pilot-
ground-school.com/Aviation-Weather-
Principles.html
There are 3 members in this family of clouds; Stratus,
Stratocumulus and Nimbostratus.
When stratus clouds develop a scalloped bottom, it appears as
long parallel rolls or broken rounded patches. Those clouds
become Stratocumulus clouds.
Nimbostratus clouds get their name from the Latin word nimbus,
which means “rainy cloud” and stratus which means “to cover
with a layer”
13. http://www.astrobio.net/press
release/3936/the-secrets-of-
the-rain
There are a few clouds that don’t fit into any one of the
3 height categories.
These clouds are in the low height range but often
extend upward into the middle or high altitudes.
Once upward movement is triggered, acceleration is
powerful and clouds that have a high vertical range
form.
14. As the air cools, it becomes
denser and drains into low
areas such as river valleys
where thick fog accumulations
can take place.
When cool air moves over
warm water, enough moisture
may evaporate from the water
surface to create saturation. http://www.williamsclass.com/Ei
ghthScienceWork/Atmosphere/A
As water vapor that is rising tmosphereFog.htm
meets the cold air, it
immediately condenses and
rises with the air that is being
warmed from below.
15. The Bergeron process relies
on 2 physical processes:
super saturation and super
cooling.
Water in the liquid state
below 0 degrees Celsius is
said to be “super cooled”.
When air is saturated
(100% relative humidity)
with the exception to
water, it is “super
http://www.kidsgeo.com/geography- saturated” (with the
for-kids/0112-bergeron-process.php
respect to ice: greater than
100% humidity)
16. In warms clouds, the
mechanism that forms
raindrops is the collision-
coalescence process.
As these large droplets move
through the cloud, they
collide and join together
with smaller, slower
droplets.
http://www.atmo.arizona.ed
u/students/courselinks/sprin
g07/nats101s2/lecture_note
s/mar30.html
17. http://www.shutterstock.com/pic-
65745589/stock-photo-heavy-cloud-
with-rain-and-snow-hi-res-d-
rendered-icon-with-clipping-
paths.html
In meteorology, the term rain means drops of water that fall from
a cloud and have a diameter of at least 0.5mm.
When the surface temperature is above 4 degrees Celsius,
snowflakes usually melt and continue their decent as rain before
they reach the ground.
When temperatures are very low (when the moisture content of
air is small) light, fluffy snow made up of individual six-sided ice
crystals form.
18. Sleet is the fall of small
particles of clear to
translucent ice.
Hair is produced in
cumulonimbus clouds.
If the ice pellets come
across a strong updraft,
http://kvgktrailblazers.weebly.com/forms-
of-precipitation.html
they may be carried
upward and begin the
downward journey again.
