Ch 11

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Ch 11

• Atmosphere

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Lesson 1

• Atmospheric Basics

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Think About It

• Why would it be a bad thing if the atmosphere was
  mostly oxygen?

4
Focus Question

• What is the composition and structure of the
  atmosphere?

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Atmospheric Composition

• Nitrogen 78
• Oxygen 21
• Argon - .93
• Carbon Dioxide - .03
• Water Vapor - .0 to 4
• Trace Gases

http//www.bbc.co.uk/schools/gcsebitesize/science/
21c/atmosphere/chemicalsairrev1.shtml
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Key Atmospheric Components

• Oxygen
• Gas
• Living things breathe oxygen in order to break
  down food for energy

http//schoolworkhelper.net/wp-content/uploads/201
0/07/oxygen-transport.jpg
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Key Atmospheric Components

• Carbon Dioxide
• Gas
• Has a minor role in regulating the amount of
  energy the atmosphere absorbs and
• acts as a plant fertilizer

http//ed101.bu.edu/StudentDoc/current/ED101fa10/c
cburke/Photosynthesis.html
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Key Atmospheric Components

• Ozone
• Gas
• Absorbs ultraviolet radiation from the sun

http//mmedia.pl/ozone-layer-diagram-for-kids
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Key Atmospheric Components

• Water Vapor
• Gas
• Has a major role in regulating the amount of
  energy the atmosphere absorbs and
• is the source of clouds, rain, and snow

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Key Atmospheric Components

• Water
• Liquid
• The source of rain

Singing in the Rain!
http//mypeartreehouse.blogspot.com/
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Key Atmospheric Components

• Ice
• Solid
• Makes up snow, sleet, and hail

Legendary Vail Powder!
http//www.austinskiers.org/trips0910/vail0910.htm
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Key Atmospheric Components

• Dust and Salt
• Solids
• Provide a solid surface for water vapor to
  condense around so that clouds can form
• See next slide

Salt Spray from Waves
http//www.kidsgeo.com/images/ocean-waves.jpg
Dust Storm
http//www.weatherfreaks.net/images/dust_storm3.jp
g
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Condensation Nuclei
http//www.sci.uidaho.edu/scripter/geog100/lect/05
-atmos-water-wx/ch5-part-5-clouds-fog.htm
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The Structure of the Atmosphere

• http//ds9.ssl.berkeley.edu/lws_gems/3/images_3/la
  yat510.jpg

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The Structure of the Atmosphere The Troposphere

• Description
• 0-11 km
• highest air pressure
• Contains most of the gases of the atmosphere
• Objects Found There
• Weather
• life forms
• jets

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The Structure of the Atmosphere The Stratosphere

• Description
• 11-48 km
• Molecular heat rises due to the ozone absorbing
  heat
• Objects Found There
• Ozone layer
• Weather balloons

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The Structure of the Atmosphere The Mesosphere

• Description
• 48-95 km
• Molecular heat falls b/c theres not a whole lot
  here!
• Objects Found There
• Meteors (shooting stars) burn here

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The Structure of the Atmosphere The
Thermosphere

• Description
• 95-550 km
• Molecular heat rises
• Objects Found There
• Ionosphere
• Auroras

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The Auroras

• http//www.lovethesepics.com/2011/02/24-amazing-au
  roras-aurora-borealis-aurora-australis/

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The Structure of the Atmosphere The Exosphere

• Description
• Above 600 km
• Outermost layer
• Space!
• Objects Found There
• Some H and He
• Satellites

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Temperature Variations with Altitude
http//www.aerospaceweb.org/question/atmosphere/at
mosphere/layers.gif
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What Happens to the Suns Energy?
http//www.physicalgeography.net/fundamentals/imag
es/cascade.GIF
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Solar Fundamentals

• a. Radiation
• the transfer of energy through space by visible
  light, ultraviolet radiation, and other
  electromagnetic waves
• Earths surface is warmed by the suns rays

http//ossfoundation.us/projects/environment/globa
l-warming/earths-radiation-budget
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Solar Fundamentals

• a. Conduction
• the transfer of energy that occurs when
  molecules collide
• The air molecules above Earths surface are
  warmed when they contact the warm surface of Earth

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Solar Fundamentals

• a. Convection
• the transfer of energy by the flow of a heated
  substance
• Warm air rises, then cools and sinks

http//avstop.com/ac/fig5-9.jpg
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The Transfer of Heat in the Atmosphere

• Copy the diagram your teacher draws on the board!

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Lesson 2

• The State of the Atmosphere

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Think About It

• What makes a hot air balloon float?

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Focus Question

• What are the physical properties of the
  atmosphere that create weather?

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Temperature of the Atmosphere

• What is temperature?
• The measurement of how rapidly or slowly
  molecules move around
• What is heat?
• b. The transfer of energy that occurs because of
  a difference in temperature between substances
• Heat fuels atmospheric processes!

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The Temperature of the Atmosphere

• 1. The thermosphere is the hottest layer of the
  atmosphere but it feels so cold
• because even though the molecules are moving very
  fast (which means they are very hot), they are so
  far apart that there would be no heat transfer.

Astronaut Bruce McCandless II is feeling no heat!
http//www.newworldencyclopedia.org/entry/Astronau
t
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The Temperature of the Atmosphere

• Fahrenheit
• Boiling point 212
• Freezing point 32
• Absolute Zero -523

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The Temperature of the Atmosphere

• Celsius
• Boiling point 100
• Freezing point 0
• Absolute Zero
• -273

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The Temperature of the Atmosphere

• Kelvin
• Boiling point 373
• Freezing point 273
• Absolute Zero 0
• There are NO negative numbers on the Kelvin
  scale!

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Absolute Zero

• Absolute zero is the temperature at which
  molecular motion theoretically stops! This does
  not occur anyplace in the universe.
• http//www.happynews.com/news/562009/happens-absol
  ute-zero.htm

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The Temperature of the Atmosphere

• 3a. Dew Point is the temperature to which air
  must be cooled at constant pressure to reach
  saturation.
• That is when dew is formed!
• The higher the dew point, more humid and
  uncomfortable the air.
• See next slide

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Dew Point
http//www.goerie.thinkhost.com/mt/st_weather/DEW_
POINT_CHART_full.JPG
Our classroom has a high dew point!
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The Temperature of the Atmosphere

• 3b. Condensation is the process of water vapor
  changing into liquid water. It plays a role in
  creating rain when water vapor in the atmosphere
  becomes water droplets.
• 3c. Dew point is also called condensation
  temperature.

(Remember the condensation nuclei?)
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Vertical Temperature Changes

• Altitude is height above ground or sea level.
• Why is the temperature of the lower atmosphere
  cooler at higher elevations and altitudes?
• b. Because it is farther away from the source of
  heat Earths surface
• Individual air masses moving upward through the
  atmosphere will cool about 10 degrees C/1000 m.

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Vertical Temperature Changes

• What is lifted condensation level?
• The height at which condensation occurs
• The LCL often corresponds to the base of the
  clouds!

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Air Pressure and Density

• Density is mass per volume.
• As altitude increases (moving up through Earths
  atmosphere), the density of the air...
• decreases
• Air pressure is
• the force exerted by the molecules of the
  atmosphere as they are pulled toward Earths
  center.
• As altitude increases
• air pressure decreases
• Add to notes Air pressure is greatest in the
  troposphere.

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Air Pressure and Density

• 5. Air at the bottom of the atmosphere (the
  troposphere 6) has higher density and pressure
  because...
• of the greater mass of the atmosphere above
  you!
• Gravity is the force pulling all air molecules
  in the atmosphere toward Earth.
• This is similar to being at the bottom of the
  ocean with tons of water above you!
• We are accustomed to the high air pressure so
  it doesnt squash us.

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Temperature-Density Relationship

• 1a. The Relationship between Temperature and
  Density Warm Air
• As temperature increases density decreases.
• Warm air is less dense and will rise.
• The upward movement of warm air lowers pressure.
• So, warm air rising causes low pressure.

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Temperature-Density Relationship

• 1b. The Relationship between Temperature and
  Density Cold Air
• As temperature decreases density increases.
• Cold air is more dense and will sink.
• The downward movement of cold air raises
  pressure.
• So, cold air sinking causes high pressure.

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Temperature Inversion

• when the upper layers of the troposphere are
  warmer than the lower layers.
• The warmer layer is above the colder layer.
• on a cold, clear, winter night, Earths surface
  cools rapidly and becomes colder than the air
  above it resulting in upper layer of the
  troposphere being warmer!
• The warm layer can trap pollution or melt snow.

• http//www.wrh.noaa.gov/slc/climate/TemperatureInv
  ersions.php

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Creating Wind

• Cool air, which is denser, sinks.
• This forces the warm air, which is less dense to
  move upwards.
• Air moves from areas of high density to areas of
  low density.
• In its simplest form, wind can be thought of as
  air moving from an area of high pressure to an
  area of low pressure.

http//scifiles.larc.nasa.gov/text/kids/Problem_Bo
ard/problems/light/sim3.html
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Humidity Changes with Temperature

• What is humidity?
• The amount of water air can hold at a given
  temperature. This is a constant!
• 2. What is relative humidity?
• The amount of water the air is actually holding
  compared to how much it can hold

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Humidity Changes with Temperature

• 3. How much water vapor can a m3 of air hold at
  25 degrees C?
• 24 grams
• 4. How much water vapor can a m3 of air hold at
  15 degrees C?
• 13 grams
• 5. Why does the air hold more water at 25
  degrees than it does at 15 degrees C?
• Warm air can hold more water than cold air
  because it is less dense.
• 6. How much water (per m3) would the air hold in
  a room at 25 degrees C if the relative humidity
  was 50?
• 12 grams

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Lesson 3

• Moisture in the Atmosphere

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Think About It

• Can you forecast the weather by looking at clouds?

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Focus Question

• How are clouds formed and what does each type
  indicate about the weather?

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Three Ways Clouds Can Form

• a. from convection currents
• b. from warm air rising over mountains
  (orographic lifting)
• c. when air masses of different temperatures meet

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Cloud Formation Convection Currents
http//ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/cld/c
ldtyp/home.rxml
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Cloud Formation Orographic Lifting
Clouds form over a mountain.
http//www.envi.hufs.ac.kr/gwlee/session6/lift.htm
l
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Cloud Formation Frontal
http//www.windows2universe.org/earth/Atmosphere/i
mages/cloudformation_Fronts_small.jpg
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Cloud Types

• Cirro-
• Above 6000m
• Alto -
• Between 2000-6000m
• Stratus -
• Below 2000m

http//www.windows2universe.org/earth/Atmosphere/c
louds/cloud_heights.html
57
Cloud Types

• Cirrus
• Latin for hair
• Wispy, stringy clouds

http//ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/cirrus.rx
ml?hret/guides/mtr/cld/cldtyp/home.rxml
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Cloud Types

• Cumulus
• Latin for pile or heap
• Puffy, lumpy clouds

Altocumulus
http//ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/cirrus.rx
ml?hret/guides/mtr/cld/cldtyp/home.rxml
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Cloud Types

• Stratus
• Latin for layer
• Featureless sheets of clouds

Cirrostratus Halo
Nimbostratus
http//ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/cirrus.rx
ml?hret/guides/mtr/cld/cldtyp/home.rxml
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Cloud Types

• Nimbus
• Latin for cloud
• Low, gray rain clouds

Nimbostratus
http//ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/cirrus.rx
ml?hret/guides/mtr/cld/cldtyp/home.rxml
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Cloud Types

• Cumulonimbus
• Latin for puffy cloud
• Ginormous rain clouds

http//ed101.bu.edu/StudentDoc/current/ED101sp10/e
rikalee/cumulonimbus20clouds.html
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The Water Cycle
http//www.uwsp.edu/geo/faculty/ritter/geog101/tex
tbook/hydrosphere/hydrologic_cycle.html

• Water on Earths surface will turn to water vapor
  in the process of
• evaporation.
• Water vapor in clouds turns to liquid by
• condensation.
• Rain, snow, sleet, or hail falls to Earths
  surface as
• precipitation.

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Clouds
http//eo.ucar.edu/webweather/images/cloudchart.gi
f
64
More Clouds!
http//apollo.lsc.vsc.edu/classes/met130/notes/cha
pter5/summary.html
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Lesson 3 Cloud Model

• p. 288
• Create 10 clouds.
• Get a piece of blue paper.
• Title it Clouds and write your name(s) on the
  bottom left.
• Draw the ground.
• Mark the altitude on left side.
• Draw a sun.
• Glue the clouds on and label them.
• Draw rain drops under nimbus clouds.