WX 201 Final ERAU Exam Questions and
Answers
The Atmosphere
aerosol (a.k.a. particulates)
rain, drizzle, fog, snow, ice crystals, cloud droplets
Permanent gas
Nitrogen [N2]=78%
Oxygen [02]=21%
Others (Ar, Ne, He, Kr, H)=1%
Variable gas
[H2O]
-0 to 4% (highly variable)
-Most abundant variable gas•
[CO2]
-0.039% and rising
[O3]
-Highly variable, reactive gas
-Upper atmosphere: protects life from UV light
-Occurs naturally, absorbs harmful ultraviolet light from sun
Greenhouse gases
H2O, CO2, CH4, absorb infrared radiation emitted by the earth
•Re-radiate some of the infrared radiation back down
Ideal Gas Law
P=DT
Celsius calculation
C= 5/9 (F - 32)
Density
Density decreases w/ height
Standard pressure
-14.7 lbs./in2
-29.92" Hg
-1013 hPa
Layers of the atmosphere
Thermo(85k-100k)
Meso(50k-85k)
Strato(12k-50k)
Tropo(0-12k)
Troposphere
, •Between surface & about 36,000' (11 km)
-Where weather occurs (and most of the aviation takes place)
-Pressure ranges between 200 to 1030 mb
•Decreasing temperature with height
-Heated from below because the ground absorbs more of the sun's rays than air
•Has vertical air currents and turbulence
-Hazardous to aviators
Stratosphere
•Between ~ 36,000 and 160,000 '(11-50 km)
-Pressures range from about 1 to 200 mb
-Temperature increases with height in the stratosphere due to the absorption of UV radiation by
ozone
Tropopause
•Boundary between troposphere and stratosphere
•Altitude varies with latitude & with season
•Where and when is it highest & coldest? Summer in Tropical regions
•Lowest & warmest? Winter in Polar regions
•Location of lowest temp and max wind (near jet stream)
•Thunderstorm tops and high clouds extend to the tropopause
Wind w/ height
•Wind speed generally increases with height
•Wind speeds near tropopause 50-200 kt
•Maximum wind speed at tropopause
•Strongest wind shear just above & below tropopause
Isothermal layer
-A layer having constant temperature
Heat transfer mechanisms
Radiation-Transfer of energy by electromagnetic waves (light)
-Can occur across empty space
•Conduction-Transfer of heat from one molecule to another
•Convection-Random vertical air motions
-Transport by horizontal air motions = advection
electromagnetic radiation
Sun vs Earth
Earth = long wave lengths
Sun = Short wave lengths
What happens to insolation
70% absorbed by earth and its atmosphere
30% reflected back to space
earth has an albedo of 30%
Answers
The Atmosphere
aerosol (a.k.a. particulates)
rain, drizzle, fog, snow, ice crystals, cloud droplets
Permanent gas
Nitrogen [N2]=78%
Oxygen [02]=21%
Others (Ar, Ne, He, Kr, H)=1%
Variable gas
[H2O]
-0 to 4% (highly variable)
-Most abundant variable gas•
[CO2]
-0.039% and rising
[O3]
-Highly variable, reactive gas
-Upper atmosphere: protects life from UV light
-Occurs naturally, absorbs harmful ultraviolet light from sun
Greenhouse gases
H2O, CO2, CH4, absorb infrared radiation emitted by the earth
•Re-radiate some of the infrared radiation back down
Ideal Gas Law
P=DT
Celsius calculation
C= 5/9 (F - 32)
Density
Density decreases w/ height
Standard pressure
-14.7 lbs./in2
-29.92" Hg
-1013 hPa
Layers of the atmosphere
Thermo(85k-100k)
Meso(50k-85k)
Strato(12k-50k)
Tropo(0-12k)
Troposphere
, •Between surface & about 36,000' (11 km)
-Where weather occurs (and most of the aviation takes place)
-Pressure ranges between 200 to 1030 mb
•Decreasing temperature with height
-Heated from below because the ground absorbs more of the sun's rays than air
•Has vertical air currents and turbulence
-Hazardous to aviators
Stratosphere
•Between ~ 36,000 and 160,000 '(11-50 km)
-Pressures range from about 1 to 200 mb
-Temperature increases with height in the stratosphere due to the absorption of UV radiation by
ozone
Tropopause
•Boundary between troposphere and stratosphere
•Altitude varies with latitude & with season
•Where and when is it highest & coldest? Summer in Tropical regions
•Lowest & warmest? Winter in Polar regions
•Location of lowest temp and max wind (near jet stream)
•Thunderstorm tops and high clouds extend to the tropopause
Wind w/ height
•Wind speed generally increases with height
•Wind speeds near tropopause 50-200 kt
•Maximum wind speed at tropopause
•Strongest wind shear just above & below tropopause
Isothermal layer
-A layer having constant temperature
Heat transfer mechanisms
Radiation-Transfer of energy by electromagnetic waves (light)
-Can occur across empty space
•Conduction-Transfer of heat from one molecule to another
•Convection-Random vertical air motions
-Transport by horizontal air motions = advection
electromagnetic radiation
Sun vs Earth
Earth = long wave lengths
Sun = Short wave lengths
What happens to insolation
70% absorbed by earth and its atmosphere
30% reflected back to space
earth has an albedo of 30%
