Goal 2 - Weebly
Transcript of Goal 2 - Weebly
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
Key Atmospheric Components
• Carbon Dioxide
–Gas
–Minor role in absorbing heat
–plant fertilizer
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
Singing in the Rain!
http://mypeartreehouse.blogspot.com/
Key Atmospheric Components
•Ice
–Solid
–Makes up snow, sleet, and hail
Legendary Vail Powder! http://www.austinskiers.org/trips0910/vail0910.htm
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.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…
–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-borealis-
aurora-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
http://www.aerospaceweb.org/question/atmosphere/atmosphere/layers.gif
The layers are divided by temperature!
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
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.
Astronaut Bruce McCandless II is feeling no heat!
http://www.newworldencyclopedia.org/entry/Astronaut
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-absolute-zero.htm
The Temperature of the Atmosphere
3. Dew Point - 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…
The Temperature of the Atmosphere 3a. Water vapor in the atmosphere becomes 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.
–http://www.wrh.noaa.gov/slc/climate/TemperatureInversions.php
d. Draw this…
1. Creating 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
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 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
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
http://www.envi.hufs.ac.kr/gwlee/session6/lift.html
Clouds form over a mountain.
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
http://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/cirrus.rxml?hret=/guides/mtr/cld/cldtyp/home.rxml
Altocumulus
Cloud Types
•Stratus –Latin for “layer”
–Featureless sheets of clouds
http://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/cirrus.rxml?hret=/guides/mtr/cld/cldtyp/home.rxml
Cirrostratus “Halo” around sun
Nimbostratus
Cloud Types
•Nimbus –Latin for “cloud”
–Low, gray rain clouds
http://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/cirrus.rxml?hret=/guides/mtr/cld/cldtyp/home.rxml
Nimbostratus
Cloud Types
• Cumulonimbus
–Latin for “puffy cloud”
–Enormous rain clouds
http://ed101.bu.edu/StudentDoc/current/ED101sp10/erikalee/cumulonimbus%20clouds.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.
http://www.uwsp.edu/geo/faculty/ritter/geog101/textbook/hydrosphere/hydrologic_cycle.html