Goal 2.5 The Atmosphere
Lesson 1 Atmospheric Basics
Think About It Why would it be a bad thing if the atmosphere was mostly oxygen?
Focus Question What is the structure and function of the atmosphere?
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 Components Oxygen Gas Living things need oxygen to break down food for energy http://schoolworkhelper.net/wp-content/uploads/2010/07/oxygen-transport.jpg
Carbon Dioxide Gas Minor role in absorbing heat plant fertilizer Key Atmospheric Components http://ed101.bu.edu/studentdoc/current/ed101fa10/ccburke/photosynthesis.html
Key Atmospheric Components Ozone Gas Absorbs ultraviolet radiation from the sun http://mmedia.pl/ozone-layer-diagram-for-kids
Key Atmospheric Components Water Vapor Gas Major role in absorbing heat source of clouds, rain, and snow
Key Atmospheric Components Water Liquid The source of rain http://mypeartreehouse.blogspot.com/ Singing in the Rain!
Key Atmospheric Components Ice Solid Makes up snow, sleet, and hail http://www.austinskiers.org/trips0910/vail0910.htm Legendary Vail Powder!
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 http://www.weatherfreaks.net/images/dust_storm3.jpg Dust Storm
Condensation Nuclei http://www.sci.uidaho.edu/scripter/geog100/lect/05-atmos-water-wx/ch5-part-5-clouds-fog.htm
The Structure of the Atmosphere http://ds9.ssl.berkeley.edu/lws_gems/3/images_3/layat510.jpg
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
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
The Structure of the Atmosphere 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 Thermosphere Description 95-550 km Molecular heat rises Objects Found There Ionosphere Auroras
The Auroras http://www.lovethesepics.com/2011/02/24-amazing-auroras-aurora-borealisaurora-australis/
The Structure of the Atmosphere The Exosphere Description Above 600 km Outermost layer Space! Objects Found There Some H and He Satellites
Temperature Variations with Altitude The layers are divided by temperature! http://www.aerospaceweb.org/question/atmosphere/atmosphere/layers.gif
What Happens to the Sun s Energy? http://www.physicalgeography.net/fundamentals/images/cascade.gif
Solar Fundamentals a. Radiation 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 a. Conduction transfer of energy when molecules collide Air molecules above Earth s surface are warmed when they contact the warm surface of Earth
Solar Fundamentals a. Convection transfer of energy by 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 Atmosphere Copy the diagram your teacher draws on the board!
Lesson 2 The State of the Atmosphere
Think About It What makes a hot air balloon float?
Focus Question What are the physical properties of the atmosphere that create weather?
Temperature of the Atmosphere 1. What is temperature? measurement - how rapidly or slowly molecules move 2. What is heat? transfer of energy that occurs because of a difference in temperature between substances a. Heat fuels atmospheric processes!
The Temperature of the Atmosphere b. The thermosphere is the hottest layer of the atmosphere but it feels so cold b/c even though molecules are moving very fast (which means they are very hot), they are so far apart that there would be no heat transfer. http://www.newworldencyclopedia.org/entry/astronaut Astronaut Bruce McCandless II is feeling no heat!
The Temperature of the Atmosphere Write scales in margin o Fahrenheit o Boiling point 212 o Freezing point 32 o Absolute Zero -523
The Temperature of the Atmosphere o Celsius o Boiling point 100 o Freezing point 0 o Absolute Zero -273
The Temperature of the Atmosphere o Kelvin o Boiling point 373 o Freezing point 273 o Absolute Zero 0 o There are NO negative numbers on the Kelvin scale!
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-absolutezero.htm
The Temperature of the Atmosphere 3. Dew Point - temperature to which air must be cooled (at constant pressure) to reach saturation. o o o That is when dew is formed! The higher the dew point, more humid and uncomfortable the air. See next slide
http://www.goerie.thinkhost.com/mt/st_weather/dew_point_chart_full.jpg Dew Point
3a. Water The vapor Temperature in the atmosphere of the becomes Atmosphere water droplets 3b. Dew point is also called condensation temperature b/c condensation is the process of water vapor changing into liquid water. (Remember the condensation nuclei?)
Vertical Temperature Changes 4. Altitude height above ground or sea level. a. Why is the temperature of the lower atmosphere cooler at higher elevations and altitudes? b/c it is farther away from the source of heat conduction from Earth s surface Individual air masses moving upward through the atmosphere will cool about 10 degrees C/1000 m.
Vertical Temperature Changes 4b. What is lifted condensation level? height at which condensation occurs The LCL often corresponds to the base of the clouds!
Air Pressure and Density 1. Density is mass per volume. As altitude increases (moving up through Earth s atmosphere), the density of the air... decreases 2. Air pressure is force exerted by molecules of atmosphere as they are pulled toward Earth s center. a. As altitude increases air pressure decreases
Air Pressure and Density 2b. Air at the bottom of the atmosphere has higher density and pressure because... of the greater mass of the atmosphere above you (it contains the most gases) 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 Relationship 1. The Relationship between Temperature and Density: Warm Air a. As temperature increases density decreases. b. Warm air is less dense and will rise. c. The upward movement of warm air lowers pressure. d. So, warm air rising causes low pressure.
Temperature-Density Relationship 2. The Relationship between Temperature and Density: Cold Air a. As temperature decreases density increases. b. Cold air is more dense and will sink. c. The downward movement of cold air raises pressure. d. So, cold air sinking causes high pressure.
Temperature Inversion 3. Definition when upper layers of troposphere are warmer than lower layers. Warmer layers are above colder layers. Cause on cold, clear, winter night, surface cools rapidly & becomes colder than air above it, resulting in upper layer being warmer! The warm layer can trap pollution or melt snow. d. Draw this http://www.wrh.noaa.gov/slc/climate/temperatureinversions.php
http://scifiles.larc.nasa.gov/text/kids/problem_board/problems/light/sim3.html 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. 1. Creating Wind
Wind 2. The density imbalances that move air to produce wind are created by The unequal heating and cooling of Earth s surface 3. Wind is measured by anemometers (mph or kph) 4. Wind speeds increase at high altitudes b/c There are few to no obstacles there
Humidity Changes with 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 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 o 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%? o 12 grams
Lesson 3 Moisture in the Atmosphere
Think About It Can you forecast the weather by looking at clouds?
Focus Question How are clouds formed and what does each type indicate about the weather?
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
Cloud Formation Convection Currents http://ww2010.atmos.uiuc.edu/(gh)/guides/mtr/cld/cldtyp/home.rxml
Cloud Formation Orographic Lifting Clouds form over a mountain. http://www.envi.hufs.ac.kr/gwlee/session6/lift.html
Cloud Formation Frontal http://www.windows2universe.org/earth/atmosphere/images/cloudformation_fronts_small.jpg
Cloud Types Altitude Cirro- high Above 6000m Alto - middle Between 2000-6000m Stratus - low Below 2000m http://www.windows2universe.org/earth/atmosphere/clouds/cloud_heights.html
Cloud Types Meaning Cirrus Latin for hair Wispy, stringy clouds http://ww2010.atmos.uiuc.edu/(gh)/wwhlpr/cirrus.rxml?hret=/guides/mtr/cld/cldtyp/home.rxml
Cloud Types Cumulus Latin for pile or heap Puffy, lumpy clouds Altocumulus http://ww2010.atmos.uiuc.edu/(gh)/wwhlpr/cirrus.rxml?hret=/guides/mtr/cld/cldtyp/home.rxml
Cloud Types Stratus Cirrostratus Halo around sun Latin for layer Featureless sheets of clouds http://ww2010.atmos.uiuc.edu/(gh)/wwhlpr/cirrus.rxml?hret=/guides/mtr/cld/cldtyp/home.rxml Nimbostratus
Cloud Types Nimbus Latin for cloud Low, gray rain clouds Nimbostratus http://ww2010.atmos.uiuc.edu/(gh)/wwhlpr/cirrus.rxml?hret=/guides/mtr/cld/cldtyp/home.rxml
Cloud Types Cumulonimbus Latin for puffy cloud Enormous rain clouds http://ed101.bu.edu/studentdoc/current/ed101sp10/erikalee/cumulonimbus%20clouds.html
http://www.uwsp.edu/geo/faculty/ritter/geog101/textbook/hydrosphere/hydrologic_cycle.html The Water Cycle A Review! a. 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.
Clouds http://eo.ucar.edu/webweather/images/cloudchart.gif
More Clouds! http://apollo.lsc.vsc.edu/classes/met130/notes/chapter5/summary.html
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 the 2 nimbus clouds.