General Characteristics Of The Atmosphere Flashcards
Extent of the atmosphere and evidence?
Top of atmosphere does not have a clear definition
Evidence exists of atmosphere at high levels:
Satelite drag -1600km
Aurora Borealis - 1000km
Describe vertical distribution of air density;
1/2 of weight in the lower 18,000ft /5-6km
What are 3 atmospheric properties?
Mobility
Capacity for expansion
Capacity for compression
Define Mobility in regards to the atmosphere.
Air must be mobile to produce weather
Define capacity for Expansion.
Expansion causes temperature to cool and clouds to form
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Utmost importance to meteorology, without it there would be no weather
Define capacity for Compression;
Compression causes the temperature to warm, and any clouds to dissipate
List the 5 most abundant gases in the atmosphere and state the percentage of volume of the two most abundant;
Nitrogen 78%
Oxygen 21%
Water vapour <_3%
Argon 0.91%
Carbon Dioxide 0.03% (varies)
Which gas is most important to the weather and discuss why it is important.
Water vapour is the most important gas to weather
It can condense into liquid water (forming clouds and precipitation)
It can sublimate into solid water (Forming ice crystals, hail, snow, frost)
Define and state the importance of lithometeors;
Could could not form without these particles/ condensation nuclei
Define hyrdometeors;
All clouds and precipitation are composed of either liquid water droplets or ice crystals and therefore are composed of hydrometeors
Name 2 Basic forms of air pollution:
Solid particles (incomplete burning of fuel particles)(coal, fuel containing lead additives, etc)
- larger particles fall to ground
-smaller particles remain suspended in the air
How is the vertical classification of the atmosphere defined?
Divided into terms of temperature
Divisions are called spheres
Transition zone between two spheres is a “pause”
State the 3 lowest vertical divisions, and their pauses (and the fourth for a bonus point!)
From the surface upward:
- Troposphere
\ Tropopause
- Stratosphere
\ Stratopause
- Mesosphere
\ Mesopause
- Thermosphere
Describe the Troposphere;
Temperature decreases with height to its upper limit called the tropopause
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Almost all weather occurs in the troposphere, due to its precense of water vapour and vertical air currents
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Winds increase with height to reach a maximum just below the tropopause
Describe the tropopause;
Dividing line between the troposphere and the stratosphere
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Occurs when temperature stops decreasing and becomes constant with height (isothermal)
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Height lowest over cold air and highest over warm air
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Average height: 11km/36,000ft
|\ Poles: 7km /25,000 ft
\ Equator: 15km/ 56,000 ft
Higher tropopause = higher base of cirrus
What affects the topopause height? (3)
Seasons - higher in summer than winter
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Air mass - higher in warmer than colder airmasses
Describe the Stratosphere;
Ozone absorbs ultraviolet light (UV)
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Nacreous clouds appear here
\ (Mother of pearl) clouds indicate the presence of minute amounts of W.V. in form of ice crystals
Describe the Mesosphere;
Meteors burn up in the mesosphere
Describe the Thermosphere;
Aurora Borealis /Northern Lights occur here
What are the four spheres of the atmosphere starting at the surface?
Stratosphere
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Mesosphere
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Thermosphere
Which sphere contains almost all the atmosphere’s clouds, precipitation, and lithometeors?
Troposphere
Which sphere contains the highest concentration of Ozone?
Stratosphere
What (3) factors cause the tropopause to vary with height AND what do all 3 take into consideration?
All take temperature variations into account
Discuss the variable height of the tropopause due to latitude, Season, and air mass with relation of the height of cirrus.
Lowest over cold air
Highest over warm air
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Average Height: 11km
Avg H @ Poles: 7km / 36,000ft
Avg H @ @ Equator: 15 km / 56,000ft
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Normally the higher the tropopause the higher the base of cirrus.
State the purpose of the ICAO* Standard atmosphere and describe it from the surface to 65,000 ft.
* (International Civil Aviation Organization)
The ICAO Standard Atmosphere (ISA) is:
the average values for meteorological elements at 40⁰N Latitude from mean sea level (MSL) to 105,000ft (32km) based on dry air.
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Define mesoscale, synoptic scale, and planetary scale.
Mesoscale: on the order of a few kilometers to some tens of kilometers
- ex: Thunderstorm/Sea Breeze/Mountain wind
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Synoptic scale: on the order of several hundred to 2 thousand kilometers
- ex: Migratory Lows & High Pressure systems
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Planetary scale: on the order of several thousand kilometers
- ex: Long wave troughs & ridges
