Ch 11 Atmosphere. Lesson 1 Atmospheric Basics Think About It… Why would it be a bad thing if the atmosphere was mostly oxygen?

Ch 11 Ch 11 AtmosphereAtmosphere

Lesson 1Lesson 1Atmospheric BasicsAtmospheric Basics

Think About It…Think About It…

Why would it be a bad thing if the atmosphere was

mostly oxygen?

Focus Question…Focus Question…

What is the composition and structure of the atmosphere?

Atmospheric Composition…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

Key Atmospheric Key Atmospheric ComponentsComponents

•Oxygen– Gas– Living things

breathe oxygen in order to break down food for energy

http://schoolworkhelper.net/wp-content/uploads/2010/07/oxygen-transport.jpg


•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/ccburke/Photosynthesis.html


•Ozone– Gas– Absorbs

ultraviolet radiation from the sun

http://mmedia.pl/ozone-layer-diagram-for-kids


• 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


•Water– Liquid– The source of

rain

Singing in the Rain!http://mypeartreehouse.blogspot.com/


•Ice– Solid– Makes up snow,

sleet, and hail

Legendary Vail Powder!http://www.austinskiers.org/trips0910/vail0910.htm


•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 Stormhttp://www.weatherfreaks.net/images/dust_storm3.jpg

Condensation Nuclei…Condensation Nuclei…

http://www.sci.uidaho.edu/scripter/geog100/lect/05-atmos-water-wx/ch5-part-5-clouds-fog.htm

•http://ds9.ssl.berkeley.edu/lws_gems/3/images_3/layat510.jpg

The Structure of the The Structure of the Atmosphere …Atmosphere …

The Structure of the The Structure of the Atmosphere – The TroposphereAtmosphere – The Troposphere

• Description… – 0-11 km– highest air

pressure – Contains most of

the gases of the atmosphere

• Objects Found There – Weather – life forms– jets

The Structure of the The Structure of the Atmosphere – The StratosphereAtmosphere – The Stratosphere

• Description… – 11-48 km– Molecular heat

rises due to the ozone absorbing heat

• Objects Found There – Ozone layer– Weather balloons

The Structure of the The Structure of the Atmosphere – The MesosphereAtmosphere – The Mesosphere

• Description…– 48-95 km– Molecular heat falls

b/c there’s not a whole lot here!

• Objects Found There– Meteors (shooting

stars) burn here

The Structure of the Atmosphere – The Structure of the Atmosphere – The Thermosphere The Thermosphere

• Description…– 95-550 km– Molecular heat

rises • Objects Found There

– Ionosphere– Auroras

The Auroras…The Auroras…http://www.lovethesepics.com/2011/02/24-amazing-auroras-aurora-borealis-aurora-australis/

The Structure of the The Structure of the Atmosphere – The Exosphere Atmosphere – The Exosphere

• Description…– Above 600 km– Outermost layer– Space!

• Objects Found There– Some H and He– Satellites

Temperature Variations with Temperature Variations with AltitudeAltitude

http://www.aerospaceweb.org/question/atmosphere/atmosphere/layers.gif

What Happens to the Sun’s What Happens to the Sun’s Energy?Energy?

http://www.physicalgeography.net/fundamentals/images/cascade.GIF

Solar Fundamentals…Solar Fundamentals…a. Radiation

– the transfer of energy through space by visible light, ultraviolet radiation, and other electromagnetic waves

– Earth’s surface is warmed by the sun’s rays

http://ossfoundation.us/projects/environment/global-warming/earths-radiation-budget

Solar Fundamentals…Solar Fundamentals…a. Conduction

– the transfer of energy that occurs when molecules collide

– The air molecules above Earth’s surface are warmed when they contact the warm surface of Earth

Solar Fundamentals…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

The Transfer of Heat in the The Transfer of Heat in the Atmosphere…Atmosphere…

Copy the diagram your teacher draws on the

board!

Lesson 2Lesson 2The State of the The State of the

AtmosphereAtmosphere


What makes a hot air balloon float?


What are the physical properties of the

atmosphere that create weather?

Temperature of the Atmosphere…Temperature of the Atmosphere…

a. What is temperature?a. The measurement of how rapidly or

slowly molecules move around

b. What is heat?b. The transfer of energy that occurs

because of a difference in temperature between substances

Heat fuels atmospheric processes!

The Temperature of the The Temperature of the AtmosphereAtmosphere

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/Astronaut


o Fahrenheit…o Boiling point …

212o Freezing point …

32o Absolute Zero … -

523


o Celsius…o Boiling point …


0o Absolute Zero … -273


o Kelvin…o Boiling point …


273o Absolute Zero …

0o There are NO

negative numbers on the Kelvin scale!

Absolute Zero…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-absolute-zero.htm


3a. Dew Point is the temperature to which air must be cooled at constant pressure to reach saturation.

o That is when dew is formed!o The higher the dew point, more humid

and uncomfortable the air. o See next slide…

Dew Point…Dew Point…

Our classroom has a high dew point!

http://www.goerie.thinkhost.com/mt/st_weather/DEW_POINT_CHART_full.JPG


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?)

Vertical Temperature Vertical Temperature ChangesChanges

a. Altitude is height above ground or sea level.

b. 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 – Earth’s surface

c. Individual air masses moving upward through the atmosphere will cool about 10 degrees C/1000 m.

Vertical Temperature Vertical Temperature ChangesChanges

d. What is lifted condensation level?d. The height at which condensation occurs

e. The LCL often corresponds to the base of the clouds!

Air Pressure and Density…Air Pressure and Density…1. Density is mass per volume.2. As altitude increases (moving up through Earth’s

atmosphere), the density of the air... … decreases

3. Air pressure is… … the force exerted by the molecules of the atmosphere

as they are pulled toward Earth’s center.

4. As altitude increases… … air pressure decreases

Add to notes… Air pressure is greatest in the troposphere.

Air Pressure and Density…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 doesn’t squash us.

Temperature-Density Temperature-Density RelationshipRelationship

1a. The Relationship between Temperature and Density: Warm Air…

i. As temperature increases… density decreases.

ii. Warm air is less dense and will rise.

iii. The upward movement of warm air lowers pressure.

iv. So, warm air rising causes low pressure.

Temperature-Density Temperature-Density RelationshipRelationship

1b. The Relationship between Temperature and Density: Cold Air…

i. As temperature decreases… density increases.

ii. Cold air is more dense and will sink.

iii. The downward movement of cold air raises pressure.

iv. So, cold air sinking causes high pressure.

Temperature InversionTemperature Inversiona. when the upper layers of

the troposphere are warmer than the lower layers.

b. The warmer layer is above the colder layer.

c. on a cold, clear, winter night, Earth’s surface cools rapidly and becomes colder than the air above it resulting in upper layer of the troposphere being warmer!

d. The warm layer can trap pollution or melt snow.

–http://www.wrh.noaa.gov/slc/climate/TemperatureInversions.php

Creating Creating Wind…Wind…

a. Cool air, which is denser, sinks.

b. This forces the warm air, which is less dense to move upwards.

c. Air moves from areas of high density to areas of low density.

d. 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_Board/problems/light/sim3.html

Humidity Changes with Humidity Changes with Temperature…Temperature…

1. What is humidity?o The amount of water air can hold at a

given temperature. This is a constant!

2. What is relative humidity?o The amount of water the air is actually

holding compared to how much it can hold

Humidity Changes with Humidity Changes with Temperature…Temperature…

3. How much water vapor can a m3 of air hold at 25 degrees C?

o 24 grams

4. How much water vapor can a m3 of air hold at 15 degrees C?

o 13 grams

5. Why does the air hold more water at 25 degrees than it does at 15 degrees C?

o 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%?

o 12 grams

Lesson 3Lesson 3Moisture in the Moisture in the

AtmosphereAtmosphere


Can you forecast the weather by looking at

clouds?


How are clouds formed and what does each type

indicate about the weather?

Three Ways Clouds Can Three Ways Clouds Can Form…Form…

a. from convection currents

b. from warm air rising over mountains (orographic lifting)

c. when air masses of different temperatures meet

Cloud Formation – Cloud Formation – Convection CurrentsConvection Currents

http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/cld/cldtyp/home.rxml

Cloud Formation – Cloud Formation – Orographic LiftingOrographic Lifting

http://www.envi.hufs.ac.kr/gwlee/session6/lift.html

Clouds form over a mountain.

Cloud Formation – FrontalCloud Formation – Frontal

http://www.windows2universe.org/earth/Atmosphere/images/cloudformation_Fronts_small.jpg

Cloud Types…Cloud Types…• Cirro-

– Above 6000m

• Alto - – Between 2000-

6000m

• Stratus - – Below 2000m

http://www.windows2universe.org/earth/Atmosphere/clouds/cloud_heights.html

Cloud TypesCloud Types

•Cirrus–Latin for “hair”

–Wispy, stringy clouds

http://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/cirrus.rxml?hret=/guides/mtr/cld/cldtyp/home.rxml


•Cumulus–Latin for “pile” or “heap”

–Puffy, lumpy clouds


Altocumulus


•Stratus –Latin for “layer”

–Featureless sheets of clouds


Cirrostratus “Halo”

Nimbostratus


•Nimbus –Latin for “cloud”

–Low, gray rain clouds


Nimbostratus

Cloud TypesCloud Types• Cumulonimbus

–Latin for “puffy cloud”

–Ginormous rain clouds

http://ed101.bu.edu/StudentDoc/current/ED101sp10/erikalee/cumulonimbus%20clouds.html

The Water CycleThe Water Cyclea. Water on Earth’s

surface will turn to water vapor in the process of…o evaporation.

b. Water vapor in clouds turns to liquid by o condensation.

c. Rain, snow, sleet, or hail falls to Earth’s surface as o precipitation.

http://www.uwsp.edu/geo/faculty/ritter/geog101/textbook/hydrosphere/hydrologic_cycle.html

Clouds…Clouds…

http://eo.ucar.edu/webweather/images/cloudchart.gif

More Clouds!More Clouds!

http://apollo.lsc.vsc.edu/classes/met130/notes/chapter5/summary.html

Lesson 3 Cloud Model…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.

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Ch 11 Atmosphere. Lesson 1 Atmospheric Basics Think About It… Why would it be a bad thing if the atmosphere was mostly oxygen?