water in the atmosphere earth science/geology mr. traeger
TRANSCRIPT
Water in the Water in the AtmosphereAtmosphere
Earth Science/GeologyEarth Science/Geology
Mr. TraegerMr. Traeger
We must understand the properties We must understand the properties of water in order to understand how of water in order to understand how
it behaves in the atmosphere.it behaves in the atmosphere.The structure of water looks like “Mickey Mouse.” Two Hydrogens and One Oxygen bond to make H2O.
We must understand the properties We must understand the properties of water in order to understand how of water in order to understand how
it behaves in the atmosphere.it behaves in the atmosphere.Water molecules bond in hydrogen bonding where the positive hydrogen bonds with the negative oxygen.
This bonding of molecules allows This bonding of molecules allows for changes of state of water.for changes of state of water.
Water molecules bond in hydrogen bonding where the positive hydrogen bonds with the negative oxygen.
Water is the only Water is the only substance that commonly substance that commonly exists in all three states of exists in all three states of matter. This is solid, liquid, matter. This is solid, liquid, and gas (Spaulding, 390).and gas (Spaulding, 390).
Here are the Here are the states of water. states of water.
See page 391 in See page 391 in your book for a your book for a better diagram. better diagram.
Note where heat Note where heat is released and is released and where heat is where heat is
absorbed.absorbed.
Remember when we heated water from Remember when we heated water from ice to water to steam? This is the graph ice to water to steam? This is the graph
that we did in class.that we did in class.Phase Changes of Water
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Energy goes into melting ice.
Energy goes into heating water from melting point of zero degrees Celsius to boiling point of 100 degrees Celsius.
Energy goes into evaporation of water.
Notice how water goes through phase Notice how water goes through phase changes from solid (ice) to liquid changes from solid (ice) to liquid
(water) to gas (water vapor).(water) to gas (water vapor).Phase Changes of Water
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Energy goes into melting ice.
Energy goes into heating water from melting point of zero degrees Celsius to boiling point of 100 degrees Celsius.
Energy goes into evaporation of water.
Water melts at zero degrees Celsius Water melts at zero degrees Celsius and boils at 100 degrees Celsius.and boils at 100 degrees Celsius.
Phase Changes of Water
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Energy goes into melting ice.
Energy goes into heating water from melting point of zero degrees Celsius to boiling point of 100 degrees Celsius.
Energy goes into evaporation of water.
The change of state of water The change of state of water contributes to the Water Cycle, the contributes to the Water Cycle, the
unending circulation of water unending circulation of water throughout the planet. See page 13 in throughout the planet. See page 13 in
your book for more details.your book for more details.
HumidityHumidityThe City of Atlanta, Georgia has
very high humidity in the summertime! What does it feel like
when it is hot and humid?
What is Specific What is Specific Humidity?Humidity?
Specific Humidity is the Specific Humidity is the actual amount of water actual amount of water vapor in the air. It does vapor in the air. It does
not depend on not depend on temperature. It is temperature. It is
expressed in grams of expressed in grams of water per kilograms of air.water per kilograms of air.
What is Relative What is Relative Humidity?Humidity?
Relative Humidity is the Relative Humidity is the actual amount of water actual amount of water
vapor in the air compared vapor in the air compared to the maximum amount to the maximum amount
of water vapor the air can of water vapor the air can hold.hold.
Relative humidity is Relative humidity is expressed in percentage.expressed in percentage.
If the air has a specific If the air has a specific humidity of 50 g/kg and humidity of 50 g/kg and
the air will hold 100 g/kg, the air will hold 100 g/kg, what is the relative what is the relative
humidity?humidity?
50 / 100 = 0.550 / 100 = 0.50.5 X 100 = 500.5 X 100 = 50
So the relative humidity is So the relative humidity is 50%. 50%.
If the air has a relative If the air has a relative humidity of 100%, what humidity of 100%, what
will happen?will happen?
Go Go herehere to see the different to see the different types of clouds. Go here to types of clouds. Go here to
see even more clouds!see even more clouds!
Multiple cloud layers as seen from the Multiple cloud layers as seen from the air climbing out of Minneapolis, MN on air climbing out of Minneapolis, MN on
12/31/05. Stratus clouds below and 12/31/05. Stratus clouds below and cirrostratus/cirrocumulus clouds abovecirrostratus/cirrocumulus clouds above
Clouds or fog will form when Clouds or fog will form when the temperature and dew the temperature and dew
point are the same.point are the same.
But in order for clouds or fog to But in order for clouds or fog to form, small dust particles called form, small dust particles called
condensation nucleicondensation nuclei are required! are required!
Fog is a cloud at or near Fog is a cloud at or near the the groundground..
RadiationRadiation fog is formed when fog is formed when moist air near the ground is cooled moist air near the ground is cooled to dew point on a cold, clear night.to dew point on a cold, clear night.
AdvectionAdvection fog is formed when fog is formed when warm, moist air moves over a warm, moist air moves over a
cold ocean surface. The fog off cold ocean surface. The fog off of our coast is advection fog.of our coast is advection fog.
Cloud FormationCloud FormationA cloud will form at the elevation A cloud will form at the elevation
where the temperature and dew point where the temperature and dew point are the same.are the same.
Cloud StabilityCloud StabilityFlat clouds like stratus clouds are Flat clouds like stratus clouds are
stablestable. This means that the center of . This means that the center of the cloud is colder or at the same the cloud is colder or at the same
temperature as outside.temperature as outside.
Cloud StabilityCloud StabilityClouds with vertical growth Clouds with vertical growth
are said to be are said to be unstableunstable, , which means the center of which means the center of the cloud is warmer than the cloud is warmer than the air outside. Warm air the air outside. Warm air
will rise.will rise.
Cloud StabilityCloud StabilityInstabilityInstability in a cumulonimbus cloud leads to in a cumulonimbus cloud leads to
thunderstorms, lightning, hail, flooding, wind, and thunderstorms, lightning, hail, flooding, wind, and tornadoes.tornadoes.
Lapse ratesLapse ratesA lapse rate is how fast A lapse rate is how fast air cools with altitude. air cools with altitude.
You can use this value to You can use this value to calculate the altitude at calculate the altitude at which a cloud will form.which a cloud will form.
Lapse ratesLapse ratesDry air cools at a rate of Dry air cools at a rate of around 10around 10°C per every °C per every
1000 meters1000 meters..
Lapse ratesLapse ratesMoist air cools at an Moist air cools at an
average of 7average of 7°C per every °C per every 1000 meters1000 meters..
Cloud formationCloud formationA cloud will form when A cloud will form when
the temperature and dew the temperature and dew point temperature are the point temperature are the same. See an animation same. See an animation
of cloud formation.of cloud formation.
Cloud formation problem #1Cloud formation problem #1The temperature at the surface is The temperature at the surface is 2020°C and the dew point is 10°C. °C and the dew point is 10°C.
Assuming that the dew point Assuming that the dew point temperature does not decrease temperature does not decrease
(which it does), what altitude will the (which it does), what altitude will the cloud form at? Assume that there is cloud form at? Assume that there is dry air between the surface and the dry air between the surface and the
cloudcloud..
Cloud formation problem #1Cloud formation problem #1AnswerAnswer
2020°° -10 -10°° = 10 = 10°° Dry air cools 10Dry air cools 10° C for every 1000 ° C for every 1000
meters.meters.So, the cloud will form at 1000 So, the cloud will form at 1000
meters!meters!
Cloud formation problem #2Cloud formation problem #2The temperature at the surface is The temperature at the surface is 3030°C and the dew point is 5°C. °C and the dew point is 5°C. Assuming that the dew point Assuming that the dew point
temperature does not decrease temperature does not decrease (which it does), what altitude will the (which it does), what altitude will the cloud form at? Assume that there is cloud form at? Assume that there is dry air between the surface and the dry air between the surface and the
cloudcloud..
Cloud formation problem #2Cloud formation problem #2AnswerAnswer
3030°° -5 -5°° = 25 = 25°° Dry air cools 10Dry air cools 10° C for every 1000 ° C for every 1000
meters.meters.So, the cloud will form at 2500 So, the cloud will form at 2500
meters!meters!
PrecipitationPrecipitation
PrecipitationPrecipitationforms when clouds become forms when clouds become
saturated with water.saturated with water.
There are different kinds of There are different kinds of precipitation.precipitation.
Rain Rain droplets droplets grow by grow by collision collision
with other with other water water
droplets.droplets.
Drizzle is Drizzle is a light rain a light rain where the where the drops are drops are
small.small.
Ice Ice crystals or crystals or
super super cooled cooled
droplets droplets usually usually form in form in clouds.clouds.
If the flake If the flake does not does not
melt melt before before
hitting the hitting the ground, ground, we call we call
this snow.this snow.
Sleet are Sleet are raindrops raindrops that re-that re-
freeze as freeze as they fall they fall
through the through the sky.sky.
Freezing rain Freezing rain is when rain is when rain
freezes freezes instantly instantly
when hitting when hitting the ground.the ground.
HailHail is frozen is frozen ice that grows ice that grows in updrafts and in updrafts and downdrafts of downdrafts of
thunderstorms. thunderstorms. It finally It finally
becomes too becomes too heavy and falls heavy and falls to the ground.to the ground.
Precipitation is Precipitation is measured using measured using
a rain gauge. a rain gauge. Snow must be Snow must be
melted to melted to determine its determine its
water content.water content.
Precipitation occurs where moist air Precipitation occurs where moist air rises and cools.rises and cools.
There is little or no precipitation There is little or no precipitation where air sinks and warms.where air sinks and warms.
The The rain shadow effect rain shadow effect determines determines precipitation amounts. Go here for precipitation amounts. Go here for
another rain shadow animation.another rain shadow animation.
The rain shadow effect seen from the The rain shadow effect seen from the air. Picture taken on 12/31/05 on air. Picture taken on 12/31/05 on
approach into LAX. Mt. San Jacinto and approach into LAX. Mt. San Jacinto and Palm Springs are in the distance.Palm Springs are in the distance.
The rain shadow effect as seen from visible and infrared The rain shadow effect as seen from visible and infrared satellite images taken on May 30, 2007. satellite images taken on May 30, 2007. Notice the Notice the
unstableunstable cloud development (cumulonimbus clouds) cloud development (cumulonimbus clouds) over the Sierra Nevada Mountains.over the Sierra Nevada Mountains. Also notice the Also notice the stablestable marine layer (stratus clouds) near the coast marine layer (stratus clouds) near the coast..
Infrared Image Visible Image
Average Precipitation in Average Precipitation in CaliforniaCalifornia
Dry areas occur on the east (leeward) Dry areas occur on the east (leeward) side of mountains. Wet areas occur on side of mountains. Wet areas occur on the west (windward) side of mountains.the west (windward) side of mountains.
The Northern part of the The Northern part of the state gets more state gets more
precipitation because precipitation because more low pressure storms more low pressure storms
go through that area. go through that area. Central and Southern Central and Southern California are usually California are usually under the influence of under the influence of
high pressure and clear high pressure and clear weather. See pages 422-weather. See pages 422-425 for more details on 425 for more details on
pressure patterns.pressure patterns.
Water Resources: Owens ValleyWater Resources: Owens ValleyThe Los Angeles Aqueduct SystemThe Los Angeles Aqueduct System
Water Resources: Water Resources: Colorado RiverColorado River
The Los Angeles The Los Angeles Aqueduct SystemAqueduct System
Water Resources: GroundwaterWater Resources: Groundwater
Water Resources: Local streams Water Resources: Local streams and reservoirsand reservoirs
Population Growth in the Imperial Population Growth in the Imperial Valley: Will our water resources be able Valley: Will our water resources be able
to support the projected population to support the projected population growth?growth?
Red areas mean more and healthier Red areas mean more and healthier crops.crops.June 9,1973 June 30,1992
No more water left over for Mexico? No more water left over for Mexico? Compare the crop health in the U.S. Compare the crop health in the U.S.
to the crop health just across the to the crop health just across the border in Mexico. Can you see the border in Mexico. Can you see the
border?border?
Go here for a water use survey!Go here for a water use survey!Go here for water science for Go here for water science for
schools!schools!