Atmospheric Science Review Exam 1
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- What is the atmosphere made up of?
- 99% gas; <20 miles wide; made of air=mixture of gases
- What does is meant by "Mixture of Gases"
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Mixture: evenly distributed; but ingredients is still distinct.
Gas: state of nature where molecules move freely & the gas expands to fill a volume. - What are the constituents of air?
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1. Constant Constituents
2. Variable Constituents - What are constant constituents?
- "well mixed": occur in the same abundance wherever you are; have sources and sinks, but they are in 'dynamic equilibrium'; Nitrogen=78% (takes up space); Oxygen=21% (respiration/photosynthesis); Argon=.9%(space); Neon=.0018%(space)
- What are variable constituents?
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"Sources"- where gases are coming from.
"Sinks"- where gases are going
Water vapor(humidity)=1% (sr- evaporation in lakes, sk- condensation w/ rain); Carbon Dioxide=.036% (sr- smoke & respiration, sk- photosynthesis during summer when plants are active there is a greater sink/plants are dormat in winter then there are more sources than sinks); Methane=.00017% (sr- cattle flatulence, rice paddies, termites); Nitrous Oxide=.00003% (sr- coal fire powerplants) - What are aerosols?
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Suspended liquids & solids in the atomosphere.
Solids & liquids= smoke, ash, pollen, dusk, salt - What is the Origin of the atmosphere?
- 4 billion years ago; 1st atmosphere= hydrogen, helium (light gases floated away); 2nd atmosphere=volcanic outgasing (Nitrogen, CO2, H2O) - sources of O2 by photosynthesis
- What is the difference between "in situ" and "remote sensing observations"?
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"In situ"= taken by equipment that is touching what it measures (thermometer/ weather balloons)
"Remote Sensing"= taken by equipment that does not touch what it measures (telescope/radars) - What is water vapor?
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Hydrolic cycle (understanding of where water goes); keeping track of monitoring water/hydrosphere
PAGE 8, FIGURE 1.5 - What is the Ozone?
- A variable constituent; gas; a pollutant in the lower atmosphere (troposphere) - main ingredient in smog; stratosphere ozone is necessary for life on earth; absorbs UV rays, which causes skin cancer and other immune problems
- What is the Chapman Reaction?
- Where Oxygen get broken up by UV rays into ordinary oxygen to form the ozone layer.
- What are Chlorofluorocarbons (CFC's)?
- Useful substances: freon (refrig, air, ice), halon (fire extinguishers), stryrofoam blowing agents, aerosols (propellents); Possibble problems: last forever, don't disolve in water, destroy ozone (Ozone hole over Antartica caused by CFCs)
- What is the history of CFC's and how did we dodge a bullet?
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1970s- no longer put CFCs in aerosol cans;
1987- Montreal Protocol World National treaty that outlawed the production of CFCs around the world, CFCs still increase due to the previous amounts that were created;
How? -ozone/CFC issues were taken seriously, scientists knew that ozone was necessary, CFCs were something we could live w/o, ozone hole happened where no one lives - What do weather maps provide?
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-contour lines of temp. are called 'isotherms'
-contours of pressure are called 'isobars' - What is Greenwich Time?
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Universal Time Coordination; Z(Zulu)
6 hours ahead of Omaha; (130Z Jan 18, 06 is 1:30am in Greenwich or 7:30pm in Omaha Jan 17, 06) - What is the Station model?
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(decoding station model)- depicts weather at one station;
Upper left= T(temp)
Upper right= P(pressure)
Center= shading of cloud cover
Lower left= Td (dupoint temp)
Sick: points in the direction the wind is coming from
Flags: (wind speed) full=10mph, half=5mph - What are two ways to think about pressures?
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1. the force of lots of molecules hitting the surface.
2. The weight of the air above you. - What does Pressure equal?
- Pressure = Force/Area= lbs/inches squared= PSI (Pounds per square inch)
- What is a Mercury barometer?
- Measures the weight of mercury; in situ observation; Mercury is very heavy to the air pressure can only push up to 29.92"; can use this w/ any liquid, even milk shake- you are providing a vacuum through a straw but the air pressure is actually pushing up the liquid.
- What is a Aneroid Barometer?
- Aneroid (dry) measures the weight of pressure (looks like an accordian)
- What is the Metric Unit of Pressure?
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Metric Unit of Pressure= Force/Area= Newton/meters squared= Pascal (Pa)
14.7PSI=29.92 in Hg= 101,325 Pa;
Meterologists ten to use millibars=mb; 1 mb= 100 Pa; avg 1013 mb -high(1040mb), low(995mb) - How is pressure measured as the weight of the aire above you?
- If A,B,C were swimming in a pool, w/ C in the shallow end, A in the deep end and B below A in the deep end; who has the most pressure? B>A; A=C (it doesn't matter what's below)
- With increasing height, what happends to pressure?
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Pressure always decreases with height - as you go up!
For every 5.6 km up, pressure is 50% of what is was before - What is the Ideal Gas Law?
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W/ molecules boucing off a table, how could we increase pressure?
1. have molecules hit surface harder w/ increasing the temp.
2. have more molecules hit the surface w/ increasing the density of the air.
P=(rho)R(T); P=pressure, rho=density, R='a constant', T=temp. - If we have a jar with a lid, rho is constant, what happens with heating the jar? cooling the jar?
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P=(rho)R(T); inc. T & P
P=(rho)R(T); dec. T & P - If we have a hot-air balloon, pressure inside and outside the baloon is constant, what happens w/ heating the balloon?
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P=(rho)R(T); inc. T, dec rho
(This is how the balloon ftns) - What are the levels and layers in the atmosphere?
- Vertical structure of the atmosphere; layer has thickness to it, level is a place in the atmosphere.
- What is humidity?
- Source: Evaporation (at surface); Sink: Condensation (aloft); humidity usually decreases w/ height
- What is Temperature w/ in the layers/levels?
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Lapse Rate(LR)= rate at which temp. dec. w/ height.
Troposphere: Source of heat is the ground, layer, temp dec w/ height, most weather here, LR>0; Tropopause (level); Stratophere: smooth, no weather, planes fly here, temp inc w/ height (first 'inversion'), Ozone Layer, LR<0; Stratopause; Mesosphere: temp dec w/ height, LR>0; Mesopause; Thermosphere: thin, source of heat is the sun, space shuttle, 1800F, few molecules that it's actually cold in this layer - What about the layers/levels in constant constitutents?
- Constant Constituents are constant up to 90-95km, "homosphere", this is the Turbopause level. Above this line is the "heterosphere" where individual types of gases are separate: Nitrogen, Oxygen, Carbon Dioxide, Argon..
- What is the Dupoint?
- (Td) is the temperature to which we cool air; it is a warming process.
- What are two ways to Change temperature?
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1. Diabatic Temp Change: changing the temperature by adding or removing heat.
2. Adiabatic Temp Change: changing the temp w/o adding and removing heat; by raising or lowering "air parcels" - these are an idea, we don't actually have these. - What happens to an air parcel as it moves up?
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Raising air ALWAYS expands, it does work on the air around the air parcel, and cools!
The air parcel will expand b/c it has lower pressure.
WORK=ENERGY=HEAT
**For every 1 km, temp inc. 10C = Dry Adiabatic Lapse Rate (DALR)** Pos. lapse rate means that it's colder as you go up! - What happends to an air parcel as it moves down?
- Sinking air ALWAYS compresses and warms; it warms 10C per 1 km; DALR= 10C/1km
- What happens with rising air?
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Rising air always cools and expands; T=Td; condensation occurs
Moist Adiabatic Lapse Rate (MALR)= 6C/1 km - Explain the concept of the Mountain Problem.
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On the Windward Side of the mountain (left, the temp decreases by the DALR until T=Td or the Lifted Condensation Level (LCL) or the beginning of a cloud.
Here, condensation occurs and the temp is decreased by the MALR.
On the top of the mountian, the temp and dupoint are moved to the Lee Side (right). Then the temp is increased according to the DALP, b/c there is no condensation occuring. - What is the 3 Step Process of the Mountain Problem?
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1. From the Surface to LCL: cooled temp by DALR, left Td alone.
2. From LCL to top of Mountain: cooled temp by MALR, Td=T.
3. Lee side; T inc by DALR, left Td alone. - What conclusions can be made by the Mountain Problem?
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-Lee side is warmer b/c of the latent heat release.
-Lee side is drier b/c we got rid of the water vapor. - What are 4 ways to lift air?
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1. Orographic lifting ("mountains")
2. Buoyency (heat air rising)
3. Convergence at the surface (air coming together at opposite side to rise)
4. Frontal Wedging (air from one side lifting over a 'front' to cross over air fom the opposite direction) - Describe a thermometer.
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In situ observation/measurement;
It is filled with mercury or alcohol; liquid thread is the cross-sectional view of the thermometer. - What does it mean when the weather is stated "in the shade"?
- Thermometer is in the weather box ("stevenson shelter"); taken in the shade.
- What is conduction?
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Air is a very poor conductor of heat;
Ground transfers heat to air by conduction - How is the heterosphere different from the homosphere? What is the name of the level that separates these two layers of the atmosphere?
- In the homosphere, atmospheric constituents are well-mixed. In the heterosphere, all atmospheric gases tend to "settle out" into separate layers of individual gases--that is, the gases are no longer well-mixed. These two layers are separated by a level called the turbopause.
- A cold can of soda accumulates condensation as it sits out on the countertop. Is the formation of the condensation warming or cooling the drink inside the can?
- The formation of condensation on the outside of a can of soda is a WARMING process. The water vapor molecules in the air have a great deal of energy, which they must release in order to come to rest on the outer surface of the can. This energy is released as latent heat to the environment--that is, the can. The heat is used to warm the soda.
- Explain how the melting of ice is a cooling process.
- The molecules of water in an ice crystal have very little energy. In order to "melt" and join the liquid water, they are going to need to gain a lot of energy. They do this by absorbing heat from the liquid. Therefore, melting ice causes the temperature of the liquid around the ice to fall.
- What is the difference between Convection and Advection?
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Moving heat by moving a warm (or cold) fluid
Convection: moving air vertically to move heat
Advection: moving air horizontally to move heat - What is latent heat?
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This happens when water changes state:
Melting and Freezing
Ice melts at 0 C
Water doesn't necessarily freeze at 0 C ("supercooled water")
Melting is a COOLING process; think about ice in a drink
...then freezing is a WARMING process!
Latent Heat of Fusion = 80 calories per gram - What is the difference between evaporation and condensation?
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Evaporation is a COOLING process; think about sweating on a hot day
...then condensation is a WARMING process; think about a dewy night
Latent Heat of Evaporation = 600 calories per gram - What is the difference between sublimation and deposition?
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Sublimation: ice changing to vapor
Deposition: vapor changing to ice
Latent Heat of Deposition = 680 calories per gram