Structure of the Atmosphere Flashcards
Name the 5 layers of the atmosphere from top to bottom.
Exosphere
Thermosphere
Mesosphere
Stratosphere
Troposphere
Which layer do most civil flights and weather phenomena take place?
Troposphere
What are the main characteristics of the Troposphere?
A marked fall in density, pressure and temperature with height.
The presence of virtually all the atmospheric water vapour from which clouds and most atmospheric weather phenomena are derived.
What happens to temperature between the troposphere and stratosphere?
A temperature inversion takes place between the troposphere and stratosphere.
Which layer contains the biggest concentration of ozone?
Stratosphere
Is air exchanged between the troposhere and stratosphere?
No. The temperature inversion makes it virtually impossible for air to mix between the troposphere and stratosphere.
Is air dry or moist in the stratosphere?
Air is extremely dry in the stratosphere. This means basically no form of precipitation comes from the stratosphere.
What is the height of the troposphere?
The troposphere starts at ground level and reaches heights of 4-12 miles above the surface of the earth. 4 at the poles and 12 at the equator.
What is the composition of the atmosphere?
78% nitrogen
21% Oxygen
1% Other (Argon, hydrogen, helium etc)
What is the temperature lapse rate?
It is the rate at which temperature decreases with height.
At any time or place the lapse rate can take almost any value. The average value is 1.98°/1000ft
Does pressure decrease with height?
Yes
What is the average pressure at mean sea level?
1013h.25Pa
Does density decrease with height?
Yes
What is atmospheric pressure measured in?
Inches of Mercury (ins Hg)
Milibars (mb)
Hectopascals (hPa)
Are milibars and hectopascal different?
No, milibars and hectopascals have identical value.
What is the approximate decrease of pressure with height?
1hPa/30ft
