Lesson 1 Atmospheric Basics Atmospheric Composition Nitrogen 78
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/21 c/atmosphere/chemicalsairrev 1. shtml
Key Atmospheric Components • Oxygen (O 2) –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 (CO 2) –Gas –Minor role in absorbing heat –plant fertilizer http: //ed 101. bu. edu/Student. Doc/current/ED 101 fa 10/ccburke/Photosynthesis. html
Key Atmospheric Components • Ozone (O 3) –Gas –Absorbs ultraviolet radiation from the sun http: //mmedia. pl/ozone-layer-diagram-for-kids
Key Atmospheric Components • Water Vapor(H 2 O) –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 http: //www. austinskiers. org/trips 0910/vail 0910. htm Legendary Vail Powder!
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_storm 3. jpg
Condensation Nuclei… http: //www. sci. uidaho. edu/scripter/geog 100/lect/05 -atmos-water-wx/ch 5 -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
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 – 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/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… a. Conduction – transfer of energy by contact (when molecules collide) – Air molecules warmed by surface
Solar Fundamentals… a. Convection – transfer of energy by… flow of a heated substance – Warm air rises, cools & sinks http: //avstop. com/ac/fig 5 -9. jpg
Lesson 2 The State of the Atmosphere
Temperature of the Atmosphere… 1. What is temperature? …measurement - how rapidly or slowly molecules move 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
Temperature of the Atmosphere… 1. What is temperature? b. … 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. a. Dew point tells us how much water is in the air. o This is when dew is formed! o The higher the dew point, more humid and uncomfortable the air. o See next slide…
The Temperature of the Atmosphere 3 b. Dew point is also called condensation temperature b/c it’s the temperature at which condensation occurs. (Remember the condensation nuclei? )
Vertical Temperature Changes 3 c. 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! a. What is relative humidity? The amount of water the air is actually holding compared to how much it can hold b. Relative humidity is determined by. . using a wet/dry bulb thermometer & a relative humidity chart
Air Pressure and Density… 1. Density is mass (of air) per volume. 2. Air pressure is… … force exerted by molecules of atmosphere as they are pulled toward Earth’s center by gravity.
Air Pressure and Density… 2 b. 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… 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. a.
Temperature-Density Relationship 2. Cold Air… a. As temperature decreases… air becomes more dense. 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. Temp. Inversion- upper layers of troposphere are warmer than lower layers. d. Draw this… a. Warmer layers are above colder layers. b. Cause: on cold, clear, winter night, surface cools rapidly & becomes colder than air above it c. Effects: The warm layer can trap pollution or melt snow –http: //www. wrh. noaa. gov/slc/climate/Temperature. Inversions. php
http: //scifiles. larc. nasa. gov/text/kids/Problem_Board/problems/light/sim 3. html 1. Creating Wind… a. Cool air, which is denser, sinks. b. This forces the warm air, which is less dense to move up. 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.
Wind… 2. 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) 2. 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 m 3 of air hold at 25 degrees C? o 24 grams 4. How much water vapor can a m 3 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 m 3) 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
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: //ww 2010. atmos. uiuc. edu/(Gh)/guides/mtr/cldtyp/home. rxml
Cloud Formation – Orographic Lifting Clouds form over a mountain. http: //www. envi. hufs. ac. kr/gwlee/session 6/lift. html
Orographic Lifting – Mt. Washington, NH
Cloud Formation – Frontal http: //www. windows 2 universe. org/earth/Atmosphere/images/cloudformation_Fronts_small. jpg
Cloud Types…Altitude • Cirro- high – Above 6000 m • Alto - middle – Between 20006000 m • Stratus - low – Below 2000 m http: //www. windows 2 universe. 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: //ww 2010. atmos. uiuc. edu/(Gh)/wwhlpr/cirrus. rxml? hret=/guides/mtr/cldtyp/home. rxml
Altocumulus from 30, 000 ft!
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: //ww 2010. atmos. uiuc. edu/(Gh)/wwhlpr/cirrus. rxml? hret=/guides/mtr/cldtyp/home. rxml
Cumulonimbus • Latin for “puffy cloud” • Enormous storm clouds
More Clouds! http: //apollo. lsc. vsc. edu/classes/met 130/notes/chapter 5/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.
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