Transcript Notes/Science 10/January/January 12th, 2012

Science 10:
Mr. Jean
January 12th, 2012
The plan:
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Video clip of the day
Atmospheric Layers
Aurora
Clouds
• BBC – Deep Freeze
Atmospheric Layers
4
layers are defined by
constant trends in average
air temperature (which
changes with pressure and
radiation), where the outer
exosphere is not shown.
1.
2.
3.
4.
Troposphere
Stratosphere
Mesosphere
Thermosphere
Atmospheric Layers
Troposphere – Temp
decrease w/ height
Most of our weather
occurs in this layer
Varies in height
around the globe, but
Averages about 11 km
in height.
Figure 1.7
Atmospheric Layers
Stratosphere
Temperature increases in stratosphere.
Ozone plays a major part in heating the air
at this altitude
Figure 1.7
Atmospheric Layers
Mesosphere
Middle atmosphere –
Air thin, pressure low,
Air quite Cold -90°C (130°F) near the top of
mesosphere
Figure 1.7
Atmospheric Layers
Thermosphere
“Hot layer” – oxygen
molecules absorb
energy from solar
Rays warming the air.
Very few atoms and
molecules in this
Region.
Figure 1.7
The Earth has magnetic field that saves us
from being fried by cosmic radiation.
When cosmic particles get trapped in this
magnetic field they get “excited” with energy
and give off light.
Aurora (Northern Lights)
Condensation Nuclei
• Tiny particles (dust, salt) which stimulate
droplet formation
• Water is known to exist in
three different states; as a
solid, liquid or gas.
• Clouds, snow, and rain are
all made of up of some form
of water.
• A cloud is comprised of tiny
water droplets and/or ice
crystals
• A snowflake is an aggregate
of many ice crystals
• Rain is just liquid water.
• Water existing as a gas is called
water vapor.
• When referring to the amount
of moisture in the air, we are
actually referring to the amount
of water vapor.
• If the air is described as
"moist", that means the air
contains large amounts of water
vapor.
• Common sources of moisture
are the Maritime Air masses.
• A cloud naming system was invented in 1802 by Luke
Howard.
• Clouds are classified into a system that uses Latin words
to describe the appearance of clouds as seen by an
observer on the ground.
• The table below summarizes the four principal
components of this classification system
Latin Root
Translation
Example
cumulus
stratus
cirrus
nimbus
heap
layer
curl of hair
rain
fair weather cumulus
altostratus
cirrus
cumulonimbus
Classifying Clouds
• Clouds are classified according to their
form and altitude.
The three main forms: stratus clouds,
cumulus clouds and cirrus clouds.
The three altitude groups:
low clouds (up to 2000m)
middle clouds (2000 – 6000m)
high clouds (above 6000m)
Stratus Clouds
- flattened, layered shape
- cover large areas of sky
- usually form when a warm air mass overruns a cold
air mass
- indicate stable conditions
Cumulus Clouds
- puffy, “heaped” shape
- created by convective or frontal cloud formation
- usually indicate unstable weather
Cirrus Clouds
- thin, wispy clouds
- the highest clouds in the sky
- created by wind blown ice crystals
- usually indicate fair weather
• One more cloud sub-classification is
the word nimbus indicating a rain
carrying cloud
Alto = mid-level cloud
High-Level Clouds
• Cirrus - high-level clouds form above (6,000 meters) and
since the temperatures are so cold at such high
elevations, these clouds are primarily composed of ice
crystals. High-level clouds are typically thin and white in
appearance. They move across the sky on bright sunny
days. Cirrus clouds mean warm air is on the way.
Cirrus - High-level clouds
Mid-Level Clouds
• The bases of mid-level
clouds typically appear
between 2,000 to 6,000
metres. Alto- clouds,
because of their lower
altitudes, are composed
primarily of water
droplets, they can also be
composed of ice crystals
when cold enough.
Altocumulus Clouds
parallel bands or rounded masses
Low-level Clouds
• Low clouds are
mostly composed of
water droplets since
their bases generally
lie below 2,000
meters. When cold
enough, these clouds
may also contain ice
particles and snow.
Nearly all low
clouds are some
form of stratus
cloud.
Nimbostratus Clouds
dark, low-level clouds with precipitation
Stratus Clouds
Fair Weather Cumulus Clouds
puffy cotton balls floating in the sky
• Fair weather cumulus have the
appearance of floating cotton
with flat bases have a lifetime
of 5-40 minutes. The cloud tops
designates the limit of the rising
air.
• Given suitable conditions,
however, harmless fair weather
cumulus can develop into
cumulonimbus clouds
associated with thunderstorms.
Cumulus Clouds
Classification of Clouds Sheet
Label the diagram with the correct
name at the appropriate altitude.
Stratus
Stratus
http://images.google.ca/images?q=tbn:IhT6BeU74SwJ:http://www.cen
tennialofflight.gov/2003FF/clues/clipart/stratus.jpg
Stratus
Nimbostratus
Nimbostratus
Cumulus
Cumulus
Cumulus
Stratocumulus
Altostratus
Altocumulus
Cumulonimbus
Base of cloud
Cumulonimbus
Cumulonimbus
http://epod.usra.edu/archive/images/cumulonimbus_052301_sjr.jpg
Cirrocumulus
Cirrostratus
Cirrocumulus
Cirrus
Cirrus:
Nimbus
Nimbus