Transcript The Nature of Storms

Atmosphere Properties
and Weather
Notes Chapter 11-13
Atmosphere
Weather
Thin envelope of
gases that surrounds
the planet.
Weather conditions
at a locality averaged
over a specified time
period
The state of the
atmosphere at a
given place and time
Meteorology
Climate
Study of weather
and climate
Layers
of Atmosphere
Exosphere (outer space)
Ozone Layer
Weather occurs
Troposphere
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Layer closest to our earth
Extends to a height of 8-15 kilometers (5-9
miles)
Temperature ranges from (63° to -62°F)
Weather occurs here
A very large thunderstorm could extend into the
next layer of the atmosphere
The air that we breath
Can contain air pollution, bad ozone, smog
Stratosphere
 2nd
layer of the atmopshere
 Ozone layer (good ozone) that shields us
from harmful radiation from the sun
 Temperature increase as you go up
through the atmosphere
 Temperature is (27°F).
Mesosphere
 3rd
layer of the atmosphere
 Meteorites burn up in this section
 Coldest layer
Thermosphere
 4th
Layer of the atmopshere
 UV radiation is absorbed
 Shooting stars
 Hottest layer
Natural Atmosphere Processes
Ozone Shield in the Stratosphere
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Ozone shield is needed to filter out the sun’s UV
radiation. 95% filtered
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The ozone shield protects humans from skin
cancer, sun burns, eye cataracts, and damage
to the immune system
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Prevents the oxygen in the troposphere from
being converted to photochemical ozone
What causes ozone depletion?
CFC
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CFC—chlorofluorocarbons
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CFC-11 trichlorofluormethane, CFC-12 dichlorodifluoromethane
also known as freons
Odorless, colorless, nontoxic, nonreactive, nonflamable,
noncorrosive
Cheap
Used a coolants for air conditioners, refrigerators
Used as propellants in aerosol spray cans
Cleaners for computer chips
Fumigants
Insoluble to water so they remain in the atmosphere
Each molecule can last 65-385 years
Each chlorine atom converts ozone to oxygen
Anthropogenic effects on
biogeochemical cycles
Carbon cycle
Adding carbon dioxide by burning
fossil fuels, deforestation
Nitrogen cycle
Adding NOx by burning fossil
fuels, fertilizers, acid deposition
Sulfur cycle
Volcanoes, burning fossil fuels,
making acid deposition
Toxic metals
Injecting those into the
(arsenic,
atmosphere
cadmium lead)
Gases in Atmosphere
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Nitrogen (78%) & Oxygen (21%)
 Carbon dioxide & others (trace amounts)
3 methods of energy transfer:
1)
2)
3)
Radiation= transfer of energy through
space by visible light, UV light, and
electromagnetic waves EX: sun
Conduction= transfer of energy when
molecules collide EX: metals
Convection= transfer of energy by flow of
a heated substance EX: water, air
Humidity vs. Relative Humidity
 Humidity=
amount of water vapor in the air
 Relative
Humidity= ratio of water vapor in
the air relative to how much water vapor
the air can hold
 0%
very dry
 90% very wet (rain is near)
Relative Humidity
• The relative humidity tells us how “full” the
air is at the time of measurement.
• For example, 90% relative humidity means
that at that moment the air is holding 90% of
the maximum amount of water it could.
Relative Humidity
 Measure
of water vapor in the air.
 Instrument = Hygrometer
 If air holds all the water vapor it can, it is at
100% RH and is said to be saturated
Warm air can hold more water vapor.
Air Masses
There are two types of air masses:
1. Continental Polar air masses
2. Maritime Tropical air masses
Coriolis Effect
 http://www.classzone.com/books/earth_sci
ence/terc/content/visualizations/es1904/es
1904page01.cfm Animation
 Particles
are deflected in the Northern
Hemisphere to the right and in the
Southern Hemisphere to the left.
Trade Winds
 The
sun warms the air and it rises to 20 to
30 degrees to the South and the North,
then is falls back down
Jet Stream
 The
current of fast moving air
 Usually moves from East to West
Fronts
A front is the boundary separating air masses
of different densities
 Fronts extend both vertically and
horizontally in the atmosphere
Fronts: Five Types of Fronts
1. Cold Front: The zone where cold air is
replacing warmer air
• In U.S., cold fronts usually move from
northwest to southeast
• Air gets drier after a cold front moves
through
Fronts: Five Types of Fronts
2. Warm Front: The zone where warm air is
replacing colder air
• In U.S., warm fronts usually move from
southwest to northeast
• Air gets more humid after a warm front
moves through
Fronts: Five Types of Fronts
3. Stationary Front: When either a cold or
warm front stops moving
• When the front starts moving again it
returns to either being a cold or warm
front
High and Low Pressure Areas
• High pressure
causes air to sink
• Usually results in
several days of clear
sunny skies
• Air rises in low
pressure areas and
forms water
droplets
• Usually results in
rain and storms
Temperature and Thermometer
 Measurement
of how rapid or slow a
molecule move around
 Measured by a thermometer
 Units
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Fahrenheit (°F)
Celsius (°C)
Kelvin (K)
Wind Direction and Speed
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Direction is measured
with a “vane”
 Speed is measured with
an “anemometer.”
Pressure and Barometer

Air molecules push down
on objects—including us!
 Measured by Barometers
 Demonstration
Doppler Radar Effect
 Doppler
Effect is the movement of
frequencies going away or toward you as
the source moves
 Radar measures the amount of
precipitation in the air
 Doppler Radar
Pressure-Temperature-Density
Relationships
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As Temperature
, Pressure
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As Temperature
, Pressure
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As Temperature,
Density
**Temperature and Pressure are directly proportionate
(goes the same direction)
** Temperature and Density are inversely proportionate
(goes in the opposite direction)
What happens in the atmosphere
 Most
of the time, the temperature and
pressure decreases through the
troposphere
 Sometimes….the
atmosphere does not
have perfect relationships between
temperature, density, and pressure.
 Warm
Air rises, cold air sinks
Temperature Inversion
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When the cold air is on
top of the warm air.
The warm air can not
rise to release
pollution.
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This can lead to smog
and pollution closer to
the earth’s surface
Dew Point and Condensation
 Temperature
at which air must be cooled
at constant pressure to reach saturation
 Saturation=
amount that the atmosphere
can hold.
 Higher
the dew point then condensation
(changing gas to liquid) can occur and it
can rain.
Heat
 Transfer
 Hot
of energy
ALWAYS travels into the Cold
Weather Station Model
Directions:
•Read the handout again to understand what each
symbol means
•Use the chart to draw your own on in your lab book
Weather Maps
 From
the weather maps, you are going to
answer the questions about the maps in
your comp book.
Clouds
Write this on your own paper for your notes
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Turn in your textbooks to page
287
Cloud Name
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Draw this chart on the screen
Cirrus
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Using your textbook and table 113, write what the description and
Cumulus
draw a picture of the cloud
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When you have finished see me to
Stratus
pick up your construction paper
and cotton balls. You will
reconstruct the clouds out of the
cotton balls. Please label each
Nimbus
cloud.
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After everyone builds the clouds
we will go outside and observe
them
Cumulonimbus
Description
Picture
Tornadoes vs. Hurricanes
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Tornado
 Whirlwind of air on
land
 Measured by Fujita
scale
 F0-F5
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Hurricanes
 Whirlwind of air on
water
 Measured by Saffir
Simpson Index
 1-5
Severe Weather
 Thunderstorms
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All contain lighting, cumulunimbus clouds
Single Cell
Multi Cell
Super Cell  violent tornados
 May
produce flash floods/hail/tornados
 Downdrafts  damaging winds near
surface
Tornados
 Violently
rotating column of
air in contact with the ground
 Rotating updraft is a key to
the development tornado.
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Caused by wind shear
25 mph
5mph
Mesocyclone
How does lightening form?
 Air
friction in the
clouds
 Separate + and –
create voltage
channel
 Lightning kills
more people than
tornados,
hurricanes
What causes thunder?
 30,000 oC
air
expands
 “Explosion of Air”
 Light waves travel
faster than sound
waves
Weak  Strong
No greater than
110 mph
110 mph – 200mph
200 mph +
Less than 2%
Cyclones, Typhoons, Hurricanes???
 All
 All
the same thing
need energy source
= warm tropical water
Hurricanes
 Tropical
cyclones with winds that exceed
64 knots (74 mi/hr)
 circulate counter-clockwise
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Northern Hemisphere
 Clockwise
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in the
Southern Hemisphere
 Water
must be warmer than 81 F
Stages of Development
 Depression
 Storm  Hurricanes
Extreme Weather Video Clips

http://dsc.discovery.com/videos/wonders-ofweather-extreme-weather.html (extreme
weather)
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http://dsc.discovery.com/videos/wonders-ofweather-lightning-phenomena.html (lightning)
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http://dsc.discovery.com/videos/storm-chasersscience-of-storm-chasing/ (storm chasers)
Hurricanes
 http://planetgreen.discovery.com/videos/fo
cus-earth-hurricanes-and-climatechange.html (climate and hurricanes)
 http://www.pbs.org/wgbh/nova/sciencenow
/3204/02.html (hurricanes)--12 min