Lesson 1 Atmospheric Basics

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 (O2) Gas Organisms need it to break down food for energy http://schoolworkhelper.net/wp-content/uploads/2010/07/oxygen-transport.jpg

Key Atmospheric Components Carbon Dioxide (CO2) Gas Minor role in absorbing heat plant fertilizer http://ed101.bu.edu/StudentDoc/current/ED101fa10/ccburke/Photosynthesis.html

Key Atmospheric Components Ozone (O3) Gas Absorbs ultraviolet radiation from the sun http://mmedia.pl/ozone-layer-diagram-for-kids

Key Atmospheric Components Water Vapor(H2O) Gas Major role in absorbing heat source of condensation for clouds

Key Atmospheric Components Water Liquid source of rain Singing in the Rain! http://mypeartreehouse.blogspot.com/

Key Atmospheric Components Ice Solid Makes up snow, sleet, & hail Legendary Vail Powder! http://www.austinskiers.org/trips0910/vail0910.htm

Key Atmospheric Components Dust, Salt, Volcanic Ash Solids Provide solid surface for water vapor to condense (so that clouds can form) Condensation nuclei See next slide… http://www.kidsgeo.com/images/ocean-waves.jpg http://www.weatherfreaks.net/images/dust_storm3.jpg

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 – The Troposphere Description… Tropo- (change) 0-11 km highest air pressure Contains most gases of the atmosphere Objects Found There Weather life forms jets

The Structure of the Atmosphere – The Stratosphere Description… Strato- (layer) 11-48 km Molecular heat rises due to ozone layer absorbing UV radiation Objects Found There Ozone layer Weather balloons

The Structure of the Atmosphere – The Mesosphere Description… Meso- (middle) 48-95 km Temperature 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… Thermo- (heat) 95-550 km Molecular heat rises Objects Found There Ionosphere Auroras

The Structure of the Atmosphere – The Exosphere Description… Exo- (outside) Above 600 km Outermost layer Space! Objects Found There Some H and He Satellites

Temperature Variations with Altitude The layers are determined 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 electromagnetic waves - visible light, uv radiation, etc) Surface warmed by the sun’s rays http://ossfoundation.us/projects/environment/global-warming/earths-radiation-budget

Solar Fundamentals… Air molecules warmed by surface a. Conduction transfer of energy by contact (when molecules collide) Air molecules warmed by surface

Solar Fundamentals… transfer of energy by… flow of a heated substance a. Convection transfer of energy by… flow of a heated substance Warm air rises, cools & sinks http://avstop.com/ac/fig5-9.jpg

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

Temperature of the Atmosphere… 1. What is temperature? …measurement - how rapidly or slowly molecules move 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

Temperature of the Atmosphere… 1. What is temperature? … Individual air masses moving upward through the atmosphere… will cool about 10 degrees C/1000 m. Think… Pilot Mountain or Boone

Temperature of the Atmosphere… 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 is no heat transfer. http://www.newworldencyclopedia.org/entry/Astronaut

The Temperature of the Atmosphere 3. Dew Point - temperature to which air must be cooled (at constant pressure) to reach saturation. Dew point tells us how much water is in the air. This is when dew is formed! The higher the dew point, more humid and uncomfortable the air. See next slide…

The Temperature of the Atmosphere 3b. Dew point is also called condensation temperature b/c it’s the temperature at which condensation occurs. (Remember the condensation nuclei?)

Vertical Temperature Changes 3c. How is dew point determined? … determine the temperature at which dew (condensation) forms by cooling the air.

Humidity Changes with Temperature… 4. What is humidity? The amount of water air can hold at a given temperature. This is a constant! What is relative humidity? The amount of water the air is actually holding compared to how much it can hold Relative humidity is determined by....using a wet/dry bulb thermometer & a relative humidity chart

Air Pressure and Density… Density is mass (of air) per volume. Air pressure is… … force exerted by molecules of atmosphere as they are pulled toward Earth’s center by gravity.

Air Pressure and Density… 2b. Air at the bottom of the atmosphere (troposphere) has higher density and pressure because... … of the greater mass of the atmosphere above you (it contains the most gases) … 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. Warm Air… a. As temperature increases… air becomes less dense. 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. Cold Air… As temperature decreases… air becomes more dense. Cold air is more dense and will sink. The downward movement of cold air raises pressure. So, cold air sinking causes high pressure.

Temperature Inversion 3. Temp. Inversion- 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 Effects:The warm layer can trap pollution or melt snow d. Draw this… http://www.wrh.noaa.gov/slc/climate/TemperatureInversions.php

1. Creating Wind… Cool air, which is denser, sinks. http://scifiles.larc.nasa.gov/text/kids/Problem_Board/problems/light/sim3.html 1. Creating Wind… Cool air, which is denser, sinks. This forces the warm air, which is less dense to move up. 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.

Wind… The density imbalances that move air to produce wind are created by… The unequal heating of Earth’s surface Wind is measured by… anemometers (mph or kph) Wind speeds increase at high altitudes b/c… There are few to no obstacles there

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

Moisture in the Atmosphere Lesson 3 Moisture in the Atmosphere

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

Orographic Lifting – Mt. Washington, NH

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

Cirrus Latin for “hair” Wispy, stringy clouds Cirrus over Whidbey Island, WA

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

Altocumulus from 30,000 ft!

Cirrostratus “halo” around sun Cloud Types Stratus Latin for “layer” Featureless sheets of clouds Stratus clouds over Palm Coast, FL Cirrostratus “halo” around sun

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

Latin for “puffy cloud” Enormous storm clouds Cumulonimbus

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.