Atmospheric Composition Flashcards
Natural Air
Natural Air = Dry air + Condensation Nuclei +
Water Vapor
Coriolis Force
apparent force caused by the unequal speed of rotation of the earth’s surface. Deflects non-steerable bodies to the right in the N. Hemisphere.
Prevailing Westerlies
Group of winds which move our weather from the west to the east.
Methods of Heat Transfer
4 Types
Radiation
Conduction
Convection
-Strongest thermal currents occur over land surface during daylight hours
Advection - wind
Air Masses
Classification
Water Vapor Content:
- c = Continental Air Mass (Dry Air)
- m = Maritime Air Mass (Moist Air)
Temperature: (by latitudes of origin)
- A = Arctic Air Mass (70° - 90°)
- P = Polar Air Mass (40° - 60°)
- T = Tropical Air Mass (10° - 30°)
- E = Equatorial Air Mass (0° - 10°)
Symbol Name Description
cA Continental Arctic coldest, dry
cP Continental Polar cold, dry
mP Maritime Polar cold, moist
mT Maritime Tropical warm, moist
cT Continental Tropical warm, dry
E Equatorial warmest, moist
What are the components of dry air?
78% nitrogen
21% oxygen
1% miscellaneous gases
In addition to the gases present in dry air, natural air contains a variable amount of what?
water vapor and condensation nuclei
The height of the troposphere is variable from ______ feet at the poles to _____ feet at the equator.
25,000’ at poles
60,000’ at equator
Which atmospheric layer contains clouds that are of greatest concern to the aviator?
Troposphere
The most important element of weather, usually not found above the troposphere, is ______.
Moisture
What is the basic cause of atmospheric circulation?
Unequal heating of the earth by the sun
What are the three causes of the three-cell circulation?
Coriolis force
unequal heating
tilt of the earth
The air at the equator rises due to being heated by the warm surface. What type of pressure does this lifting action cause?
low pressure
In the northern hemisphere, what direction is the prevailing wind between the 30° and 60° latitudes? (Wind is ALWAYS reported FROM a direction.)
West
What are the four types of heat transfer?
Radiation
Conduction
Convention
Advection
How is heat transferred through the process of radiation?
By electromagnetic waves
What is the difference between insolation and terrestrial radiation?
Insolation is the radiation from the sun to the surface. Terrestrial radiation is the radiation given off by the earth.
What is the exchange of heat by physical contact called?
Conduction
Describe the difference between convection and advection
Convection is the exchange of heat in a vertical direction. Advection is the exchange of heat in a horizontal direction.
What conditions would cause the strongest thermal currents?
Landmass in the daytime
What is the standard temperature lapse rate?
2° per 1,000’
A layer of air, characterized by an increase in temperature with altitude, is referred to as a ____?
Temperature inversion
What would prevent a radiation (nocturnal) temperature inversion?
Overcast sky/Greenhouse effect
Explain the role of clouds in the greenhouse effect.
Clouds re-radiate terrestrial radiation back to the surface, preventing the escape of heat energy into space and a nocturnal temperature inversion.
