Download Atmospheric Water and Weather Water on Earth Heat

Atmospheric
Water
and
Weather
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Water
on
Earth
Humidity
Atmospheric
Stability
Clouds
and
Fog
Air
Masses
Atmospheric
Li=ing
Mechanisms
Midla>tude
Cyclonic
Systems
Violent
Weather
Water
on
Earth
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Quan4ty
Equilibrium
Distribu4on
of
Earth’s
Water
Today
Unique
Proper4es
of
Water
Heat
Proper4es
–  Ice
–  Water
–  Water
vapor
–  Heat
proper4es
of
water
in
nature
Heat
Proper4es
of
Water
•  Heat
Proper4es
–  Ice
–  Water
–  Water
Vapor
•  Phase
Change
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FOR WATER TO CHANGE STATES . . .
HEAT ENERGY MUST BE ABSORBED OR LIBERATED
THE AMOUNT OF HEAT ENERGY MUST BE ENOUGH
TO AFFECT THE HYDROGEN BONDS IN WATER
MOLECULES
THIS WATER/HEAT RELATIONSHIP IS A DRIVING
FORCE IN PRODUCING WEATHER . . .
PROVIDING 30% OF THE ENERGY THAT POWERS THE
GENERAL CIRCULATION OF THE ATMOSPHERE
THIS CHANGING OF STATES IS KNOWN AS PHASE
CHANGE . . .
THE CHANGE IN PHASE, OR STATE, AMONG ICE,
WATER, AND WATER VAPOR . . .
INVOLVING THE ABSORPTION OR RELEASE OF
LATENT HEAT
INCLUDES MELTING AND FREEZING . . .
AND CONDENSATION AND EVAPORATION
HEAT ENERGY IS ABSORBED AS THE LATENT HEAT . . .
OF MELTING . . .
VAPORIZATION . . .
OR EVAPORATION
HEAT ENERGY IS RELEASED AS THE LATENT HEAT
OF CONDENSATION . . .
AND FREEZING
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Humidity
•  Rela4ve
Humidity
–  Satura4on
–  Dew
Point
HUMIDITY
HUMIDITY IS THE WATER VAPOR CONTENT OF THE AIR
THE CAPACITY OF THE AIR TO HOLD WATER IS MOSTLY
A FUNCTION OF THE TEMPERATURE OF THE AIR
WARMER AIR HAS A GREATER CAPACITY FOR HOLDING
WATER THAN COOL AIR
WARM AIR STORES A GREATER AMOUNT OF
ENERGY IN THE ATMOSPHERE THAN COLDER AIR
THUS . . .
THE WARMTH OF THE AIR ENABLES THE ATMOSPHERE
TO HOLD MORE MOISTURE
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RELATIVE HUMIDITY IS THE RATIO OF WATER VAPOR
ACTUALLY IN THE AIR (THE CONTENT) . . .
COMPARED TO THE MAXIMUM WATER VAPOR THE AIR
COULD HOLD (ITS CAPACITY) AT THAT TEMPERATURE
IT IS EXPRESSED AS A PERCENTAGE
IF AIR IS DRY THE RELATIVE HUMIDITY PERCENTAGE IS
LOW
IF THE AIR IS MOIST THE RELATIVE HUMIDITY IS
HIGHER
IF THE AIR CANNOT HOLD ANY MORE MOISTURE IT IS
SATURATED AND THE RELATIVE HUMIDITY IS 100%
Atmospheric
Stability
•  Adiaba4c
Processes
•  Stable
and
Unstable
Atmospheric
Condi4ons
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Adiaba4c
Processes
•  Dry
adiaba4c
rate
–  10
C°/
1000
m
–  5.5
F°/
1000
O
•  Moist
adiaba4c
rate
–  6
C°/
1000
m
–  3.3
F°/
1000
O
REMEMBER . . .
AN ASCENDING AIR PARCEL COOLS BY EXPANSION . . .
RESULTING FROM THE REDUCED AIR PRESSURE AT
HIGHER ALTITUDES
A DESCENDING AIR PARCEL HEATS BY COMPRESSION . . .
RESULTING FROM THE INCREASED AIR PRESSURE
AT LOWER ALTITUDES
Clouds
and
Fog
•  Cloud
Types
and
Iden4fica4on
•  Fog
–  Advec4on
Fog
–  Radia4on
Fog
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CLOUDS THAT DEVELOP HORIZONTALLY AND ARE
FLAT AND LAYERED ARE STRATIFORM CLOUDS
CLOUDS THAT ARE DEVELOPED VERTICALLY
AND ARE PUFFY AND GLOBULAR ARE
CUMULIFORM CLOUDS
HIGH-ALTITUDE, WISPY CLOUDS COMPOSED OF
ICE CRYSTALS ARE CIRROFORM CLOUDS
Fog
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Advec4on
fog
Evapora4on
fog
Upslope
fog
Valley
fog
Radia4on
fog
Atmospheric
LiOing
Mechanisms
•  Convec4onal
LiOing
•  Orographic
LiOing
•  Frontal
LiOing
–  Cold
Fronts
–  Warm
Fronts
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Frontal
LiOing
•  Cold
Fronts
–  Cold
air
forces
warm
air
aloO
–  400
km
wide
(250
mi)
•  Warm
Fronts
–  Warm
air
moves
up
and
over
cold
air
–  1000
km
wide
(600
mi)
Violent
Weather
•  Thunderstorms
•  Tornadoes
•  Tropical
Cyclones
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