Download Cumulus Clouds

Week 2 Meteorology
Let’s do a really quick review
from last week.

As you increase in elevation
Copyright © 2010 Ryan P. Murphy

As you increase in elevation
Copyright © 2010 Ryan P. Murphy

As you increase in elevation
Low Pressure
Copyright © 2010 Ryan P. Murphy

As you increase in elevation air pressure
decreases.
Low Pressure
Copyright © 2010 Ryan P. Murphy

As you increase in elevation air pressure
decreases. As you decrease in elevation
Low Pressure
Copyright © 2010 Ryan P. Murphy

As you increase in elevation air pressure
decreases. As you decrease in elevation
Low Pressure
Copyright © 2010 Ryan P. Murphy

As you increase in elevation air pressure
decreases. As you decrease in elevation
Low Pressure
High Pressure
Copyright © 2010 Ryan P. Murphy

As you increase in elevation air pressure
decreases. As you decrease in elevation
pressure increases.
Low Pressure
High Pressure
Copyright © 2010 Ryan P. Murphy
• As you increase in elevation…
– air pressure decreases.
• As you increase in elevation…
– Air pressure decreases.
Low Pressure
Low Pressure
Higher Pressure
New area of Focus
Where does the Weather Engine get it’s
Energy? The Sun!
Where does this Weather Engine get it’s Water?
The Hydrologic Cycle!
• Standard sea-level pressure is 14.7 lb per
sq in. (1,030 grams per sq cm), which is
equivalent to a column of mercury 29.92
in. (760 mm) in height; (1 atm)
• The decrease with elevation is
approximately 1 in. (2.5 cm) for every 900
ft (270 m) of ascent.
As you increase in elevation air
pressure decreases. As you
decrease in elevation pressure
increases.
Copyright © 2010 Ryan P. Murphy
• Standard sea-level pressure is 14.7 lb per
sq in. (1,030 grams per sq cm), which is
equivalent to a column of mercury 29.92
in. (760 mm) in height; (1 atm)
• The decrease with elevation is
approximately 1 in. (2.5 cm) for every 900
ft (270 m) of ascent.
As you increase in elevation air
pressure decreases. As you
decrease in elevation pressure
increases.
Copyright © 2010 Ryan P. Murphy
• Standard sea-level pressure is 14.7 lb per
sq in. (1,030 grams per sq cm), which is
equivalent to a column of mercury 29.92
in. (760 mm) in height; (1 atm)
• The decrease with elevation is
approximately 1 in. (2.5 cm) for every 900
ft (270 m) of ascent.
As you increase in elevation air
pressure decreases. As you
decrease in elevation pressure
increases.
Copyright © 2010 Ryan P. Murphy
• Standard sea-level pressure is 14.7 lb per
sq in. (1,030 grams per sq cm), which is
equivalent to a column of mercury 29.92
in. (760 mm) in height; (1 atm)
• The decrease with elevation is
approximately 1 in. (2.5 cm) for every 900
ft (270 m) of ascent.
As you increase in elevation air
pressure decreases. As you
decrease in elevation pressure
increases.
Copyright © 2010 Ryan P. Murphy
• Standard sea-level pressure is 14.7 lb per
sq in. (1,030 grams per sq cm), which is
equivalent to a column of mercury 29.92
in. (760 mm) in height; (1 atm)
• The decrease with elevation is
approximately 1 in. (2.5 cm) for every 900
ft (270 m) of ascent.
As you increase in elevation air
pressure decreases. As you
decrease in elevation pressure
increases.
Copyright © 2010 Ryan P. Murphy
• In normal atmospheric pressure (1 atm), the
boiling point of water is 100 degrees Celsius.
• In normal atmospheric pressure (1 atm), the
boiling point of water is 100 degrees Celsius.
• In normal atmospheric pressure (1 atm), the
boiling point of water is 100 degrees Celsius.
• In normal atmospheric pressure (1 atm), the
boiling point of water is 100 degrees Celsius.
• In normal atmospheric pressure (1 atm), the
boiling point of water is 100 degrees Celsius.

Air Pressure drives the wind and creates
the weather.
Copyright © 2010 Ryan P. Murphy

Air Pressure drives the wind and creates
the weather.
Copyright © 2010 Ryan P. Murphy

Air Pressure drives the wind and creates
the weather.
Copyright © 2010 Ryan P. Murphy

Air Pressure drives the wind and creates
the weather.
Copyright © 2010 Ryan P. Murphy

Air Pressure drives the wind and creates
the weather.
Copyright © 2010 Ryan P. Murphy
Warm air rises, cool air sinks.
 Warm is low pressure, Cold is High
Pressure.

Copyright © 2010 Ryan P. Murphy
Warm air rises,
 Warm is low pressure, Cold is High
Pressure.

Copyright © 2010 Ryan P. Murphy
Warm air rises,
 Warm is low pressure, Cold is High
Pressure.

Copyright © 2010 Ryan P. Murphy
Warm air rises, cool air sinks.
 Warm is low pressure, Cold is High
Pressure.

Copyright © 2010 Ryan P. Murphy
Warm air rises, cool air sinks.
 Warm is low pressure,

Copyright © 2010 Ryan P. Murphy
Warm air rises, cool air sinks.
 Warm is low pressure, Cold is High
Pressure.

Copyright © 2010 Ryan P. Murphy

Which of the pictures is High Pressure?

Which of the pictures is High Pressure?

Which of the pictures is Low Pressure?

Which of the pictures is Low Pressure?

Which of the pictures is Low Pressure?

Which of the pictures is Low Pressure?

Which letter below would have warm
surface temperatures?
A
C
D
B
E

Which letter below would have warm
surface temperatures?
A
C
D
B
E

Which letter below would have cooler
atmospheric temperatures?
A
C
D
B
E

Which letter below would have cooler
atmospheric temperatures? C and E
A
C
D
B
E

Do you see any trends in the picture
below?
Copyright © 2010 Ryan P. Murphy

Answer! A band of high pressure systems
exist south of the equator.
Copyright © 2010 Ryan P. Murphy

Answer! They also exist just north of the
equator.
Copyright © 2010 Ryan P. Murphy

Answer! Low pressure systems exist below
the high pressure systems.
Copyright © 2010 Ryan P. Murphy

Answer! Low Pressure system exist at the
mid latitudes.
Copyright © 2010 Ryan P. Murphy
Copyright © 2010 Ryan P. Murphy
Copyright © 2010 Ryan P. Murphy
Copyright © 2010 Ryan P. Murphy
Copyright © 2010 Ryan P. Murphy
Copyright © 2010 Ryan P. Murphy
Surface
Pressure
Polar High
Polar Low
Subtropical High
Tropical Low
Copyright © 2010 Ryan P. Murphy

Primary High-Pressure and Low-Pressure
Areas
Copyright © 2010 Ryan P. Murphy

Primary High-Pressure and Low-Pressure
Areas
 Equatorial
low-pressure trough.
Copyright © 2010 Ryan P. Murphy

Primary High-Pressure and Low-Pressure
Areas
 Equatorial
low-pressure trough.
 Polar high-pressure cells.
Copyright © 2010 Ryan P. Murphy

Primary High-Pressure and Low-Pressure
Areas
 Equatorial
low-pressure trough.
 Polar high-pressure cells.
 Subtropical high-pressure cells.
Copyright © 2010 Ryan P. Murphy

Primary High-Pressure and Low-Pressure
Areas
 Equatorial
low-pressure trough.
 Polar high-pressure cells.
 Subtropical high-pressure cells.
 Subpolar low-pressure cells.
Copyright © 2010 Ryan P. Murphy

New Area of Focus: Fronts
Quick video (30 sec to 3 min) on cold and
warm fronts
One more video.

Warm Fronts and Cold Fronts are caused
by air pressure.
Copyright © 2010 Ryan P. Murphy
When looking at the next few slides,
remember that, in Oklahoma, Cold fronts
Normally move from the North west towards
the south east. The warm fronts come up
from the Gulf of Mexico. So, our warm fronts
usually come from the south and move in a
northerly direction.

Remember: Cold sinks, warm rises

Cold Front: Form where cold air moves
towards warm air.
 Creates
rain storms.
Copyright © 2010 Ryan P. Murphy

Cold Front: Form where cold air moves
towards warm air.
 Creates
rain storms.
Copyright © 2010 Ryan P. Murphy

Cold Front: Form where cold air moves
towards warm air.
 Creates
rain storms.
Copyright © 2010 Ryan P. Murphy
Direction
of travel
Direction
of travel
Cold
Cold
Warm
Cold
Warm
Warm
Cold
rm
Cold
Cold
Cold
Cold
Warm
Cold
Warm
Cold
W
Cold
“Honey, I think
it’s time to get
our stuff
together.”
Cold Air
Warm Air
Cold Air
Warm Air
Cold Air
Rain

Warm Front: Form where warm air moves
towards cold air.
Copyright © 2010 Ryan P. Murphy
Warm
Warm
Cold
Cold
Warm
d
Warm
Warm
Warm

Occluded front: When a cold front
overtakes a warm front and forces it up
(Mix)
Copyright © 2010 Ryan P. Murphy

Occluded front: When a cold front
overtakes a warm front and forces it up
(Mix)
Copyright © 2010 Ryan P. Murphy

Stationary Front: When a cold front and
warm front cannot overtake each other
(tie)
Copyright © 2010 Ryan P. Murphy

Stationary Front: When a cold front and
warm front cannot overtake each other
(tie)
Copyright © 2010 Ryan P. Murphy

Stationary Front: When a cold front and
warm front cannot overtake each other
(tie)
Copyright © 2010 Ryan P. Murphy

Stationary Front: When a cold front and
warm front cannot overtake each other
(tie)
Copyright © 2010 Ryan P. Murphy

Stationary Front: When a cold front and
warm front cannot overtake each other
(tie)
Copyright © 2010 Ryan P. Murphy

Stationary Front: When a cold front and
warm front cannot overtake each other
(tie)
Copyright © 2010 Ryan P. Murphy

Stationary Front: When a cold front and
warm front cannot overtake each other
(tie)
Copyright © 2010 Ryan P. Murphy

Stationary Front: When a cold front and
warm front cannot overtake each other
(tie)
Copyright © 2010 Ryan P. Murphy

Stationary Front: When a cold front and
warm front cannot overtake each other
(tie)
Copyright © 2010 Ryan P. Murphy

Stationary Front: When a cold front and
warm front cannot overtake each other
(tie)
Copyright © 2010 Ryan P. Murphy

Stationary Front: When a cold front and
warm front cannot overtake each other
(tie)
Copyright © 2010 Ryan P. Murphy

Stationary Front: When a cold front and
warm front cannot overtake each other
(tie)
Copyright © 2010 Ryan P. Murphy

Please match the name of the front to the
picture.
 Warm
Front, Cold Front, Occluded Front,
Stationary Front
A
B
C
D

Please match the name of the front to the
picture.
 Warm
Front, Cold Front, Occluded Front,
Stationary Front
A
B
C
D

Please match the name of the front to the
picture.
 Warm
Front, Cold Front, Occluded Front,
Stationary Front
A
B
C
D

Please match the name of the front to the
picture.
 Warm
Front, Cold Front, Occluded Front,
Stationary Front
A
B
C
D

Please match the name of the front to the
picture.
 Warm
Front, Cold Front, Occluded Front,
Stationary Front
A
B
C
D

Please match the name of the front to the
picture.
 Warm
Front, Cold Front, Occluded Front,
Stationary Front
A
B
C
D

Please match the name of the front to the
picture.
 Warm
Front, Cold Front, Occluded Front,
Stationary Front
A
B
C
D

Please match the name of the front to
the picture.
 Warm
Front, Cold Front, Occluded Front,
Stationary Front
A
B
C
D

Please match the name of the front to the
picture.
 Warm
Front, Cold Front, Occluded Front,
Stationary Front
A
B
C
D

Please match the name of the front to
the picture.
 Warm
Front, Cold Front, Occluded Front,
Stationary Front
A
B
C
D

Challenge Activity! Which letter best
represents a warm front?
F
A
E
B
C
D

Challenge Activity! Which letter best
represents a warm front?
F
A
E
B
C
D

Challenge Activity! Which letter best
represents a cold front?
F
A
E
B
C
D

Challenge Activity! Which letter best
represents a cold front?
F
A
E
B
C
D

Challenge Activity! Which letter best
represents an occluded front?
F
A
E
B
C
D

Challenge Activity! Which letter best
represents an occluded front?
F
A
E
B
C
D

Challenge Activity! Which letter best
represents an occluded front?
F
A
E
B
C
D

Challenge Activity! Which letter best
represents a stationary front?
F
A
E
B
C
D

Challenge Activity! Which letter best
represents a stationary front?
F
A
E
B
C
D

Challenge Activity! Which letter best
represents a stationary front?
F
A
E
B
C
D

Challenge Activity! Which letter best
represents high pressure?
F
A
E
B
C
D

Challenge Activity! Which letter best
represents high pressure?
F
A
E
B
C
D

Challenge Activity! Which letter best
represents low pressure?
F
A
E
B
C
D

Challenge Activity! Which letter best
represents low pressure?
F
A
E
B
C
D

Challenge Activity! Which letter best
represents a cyclone?
F
A
E
B
C
D

Challenge Activity! Which letter best
represents a cyclone? Answer: A
F
A
E
B
C
D

Challenge Activity! Which letter best
represents a cyclone? Answer: A
F
A
E
B
C
Weather fronts. Learn more at…
http://www.windows2universe.org/earth/At
mosphere/front.html
Weather map fronts. See more at…
http://www.nws.noaa.gov/outlook_tab.php
D
Another quick review

A video on Coriolis Effect:
https://www.youtube.com/watch?v=i2mec
3vgeaI
Cloud Formations
Let’s watch Gary England’s video on cloud
formation.
CONDENSATION
Sunlight causes water to evaporate
into the atmosphere. This air
containing the water vapor is heated
at the surface of the earth and rises.
As the air rises, it cools and the water
vapor condenses on some form of
particulate matter such as dust, ash,
or smoke to form clouds. The
particulate matter are called
Condensation Nuclei.
Condensation on spider webs
Views of early morning fog in Indiana
Importance of Clouds
•
So, what is a cloud?
~ It is a thick mass of suspended water
drops or ice crystals.
•
What do clouds tell us?
~ The presence of clouds in the sky is
one type of signal to meteorologists that
there will be changes in the weather.
Predicting the weather requires the
understanding of the different types of
clouds
Identifying Clouds
To better communicate and understand the many
cloud forms in the sky, meteorologists identify clouds
based on five basic cloud characteristics:
1. The altitude at which they occur
2. Color
3. Density
4. Shape
5. Degree of cover.
From this information, we can identify three basic
cloud types and seven other common cloud types.
Cloud Type by Form
 Clouds can be classified by some simple, but subjective,
criteria that also provides information on the atmospheric
conditions
 One form of classification is based on appearance or form.
Using these characteristics you can identify the three basic
cloud types: stratus, cirrus, and cumulus
Stratus Clouds
Stratus clouds are thin,
sheet-like clouds. They are
layered with some rippling,
and cover large portions of
the sky. They are frequently
gray and thick. Stratus
clouds are formed when air is
forced up slowly.
Cirrus Clouds




Cirrus clouds are thin, white
clouds with a feathery
appearance.
They are the highest of all
clouds forming at heights of
30,000 feet or more above
the earth's surface.
Cirrus clouds are formed by
ice crystals.
They generally occur in fair
weather and point in the
direction of air movement at
their elevation. Cirrus clouds
are usually the first sign of
an approaching storm.
Cirrus Cloud Phenomenon
Sun Pillar
Sometimes, when the sun is just below the horizon, aligned ice crystals
reflect light from their crystal faces. We see the cumulative effect of
millions of reflections of this sunlight as a sun pillar.
Cumulus Clouds:

Cumulus clouds are flatbased, billowing clouds with
vertical doming. Often the
top of cumulus clouds have
a "cauliflower-like"
appearance. Cumulus clouds
are most prominent during
the summer months.

Cumulus or fluffy clouds
form when air is forced up
rapidly and therefore rises
higher.
Cloud Type by Altitude-01
Clouds can also be classified based on their altitude
There are three categories of cloud heights:
High Clouds = Cirrus
Middle Clouds = Alto
Low Clouds = Stratus
Cirro
High clouds: 7-18km
Cold: less than 25oC & made up of ice
crystals
Cirrostratus: high, wispy
clouds. They give the sky a
milky white appearance.
Cirrocumulus: delicate clouds
appearing in bands or ripples across the
sky. They are one of the least common
of the cloud types.
Alto
These clouds usually form from the gradual lifting of air in advance of a
cold front.
Middle level clouds: 2-7 km
0-25oC & composed of both water and ice crystals
The presence of altocumulus clouds on a warm and humid summer
morning is commonly followed by thunderstorms later in the day.
Altostratus:
thin, layered
clouds that are blue-gray or whitish in color
and often cover large portions of the sky.
They are thinner if formed at higher
altitudes but are heavier and more dense if
closer to the ground.
* Picture of altocumulus clouds taken by satellite
Altocumulus:
oval or eliptical in
shape, and can have gray undersides. They often
have a "cottonball-like" appearance.
Strato
Low level clouds: 0 - 4 km
Greater than 5oC & composed of water
Stratus: Dense,
uniform dark gray
layers.
Stratocumulus: groups of
dense, puffy clouds that cover the sky in
dark heavy masses, long and gray. The
often form in
bands across the sky.
Fog
Fog : Clouds at ground level
Radiation fog: forms at night when cold ground cools the air above it (in
valleys)
Advection fog: forms when warm, moist air moves over colder surface and
cools (in coastal areas)
In this fog, off the coast of Oregon, a cold
ocean current cools the air to the air’s dew
point temperature. This cooling of the air
created the fog. This is called:
Advection Fog
For the development of this fog, warm water is
evaporating into cool air. The cool air becomes
saturated (its relative humidity becomes 100%)
and condensation creates the fog. This is called:
Cold Air
Condensation
Evaporation
Warm Water
Radiation Fog
Cloud Type by Rain

Finally, we can classify them based on the presence of rain
 Nimbus: any cloud that rains
Cumulonimbus: Nimbostratus: low,
flat clouds that are often
taller, towering
associated with
versions of cumulus
steady precipitation
clouds. Their height
and occur in thick,
can be from two to
continuous layers and
five miles. These
are often dark gray in
clouds often form
color.
thunderstorms.
Cumulonimbus Clouds
As seen from Apollo 8
Watch for Cumulus Clouds
Steps:
1. Think "puffy" when you want to identify cumulus clouds.
2. Make a comparison to masses of cotton balls or piles of
whipped cream.
3. Remember, cumulus clouds are the clouds we used to
look at and imagine they were people, shapes, animals, etc.
Watch for Nimbus Clouds
Steps:
1. Think "rain" when you see nimbus clouds.
2. Remember, nimbus clouds can be stratus or cumulus.
3. Watch for stratus clouds to evolve into nimbostratus
formations when low-level clouds shed rain.
4. Look for cumulonimbus clouds when thunderstorms begin
to build.
Watch for Stratus and Cirrus Clouds
Steps:
1. Think "flat" when you're identifying stratus clouds.
2. Remember, high altitude cirrostratus clouds appear as thin, wispy
sheets.
3. Look for stratus clouds at any altitude.
4. Look high into the sky for cirrus clouds.
5. Remember, cirrus clouds consist of moisture thrown up by distant
storms and turned to ice.
6. Watch for thin, hair-like, disconnected wisps of clouds at altitudes
above 18,000 feet.
7. Remember, stratus and cumulus clouds can occur at those same
altitudes; these clouds are correctly identified as cirrostratus and
cirrocumulus clouds.
Here are some links to online cloud matching
games.
http://extension.illinois.edu/treehouse/activit
y_cloud.cfm
THE
END