Structure of the Atmosphere Flashcards
What are the different structures of the atmosphere?
1) Troposphere
2) Stratosphere
3) Mesosphere
4) Thermosphere
5) Exosphere
What are the composition of the gases in the atmosphere?
Nitrogen = 78.1%
Oxygen = 21%
Carbon Dioxide = 0.03%
Other gases = 0.97%
What are the 3 functions of the atmosphere?
1) Radiation Protection
2) Thermal Protection
3) Support of Life
What are the physiologically important characteristics?
1) Gas Composition
2) Pressure change
3) Temperature profile
4) Ionising radiation
What are the three physiological zone?
1) Physiological zone (0 –> 10,000 feet)
2) Physiologically Deficient Zone (10,000 –> 50,000 feet)
3) The Space Equivalent Zone (> 50,000)
What is Dalton’s Law of Partial Pressures?
- The total pressure of a mixture of gases is equal to the sum of the partial pressures of each of the constituent gases.
- Pt = P1 + P2 + P3 + …
What occurs with the partial pressures and relative concentrations of the constituent gases as altitude increases?
- Partial pressures decrease
- Relative concentrations remain constant.
What is atmospheric pressure?
The force per unit area exerted on a surface by the weight of a column of air above that surface.
How is pressure measured in aviation?
Hectopascals (hPa)
How is pressure measured in physiology?
Millimeters of mercury (mmHg)
What is the MSL pressure in mmHg, hPa, bar and psi?
760 mmHg
1013.25 hPa
1 bar
14.7 psi
Where does biggest relative pressure change occur in the atmosphere?
Lower levels of the atmosphere.
What is Armstrong’s limit?
- 63,000 feet
- Point where pressure is 47 mmHg, same as body water vapour.
What are the factors that influence radiation exposure?
1) Altitude
2) Latitude
3) Solar Activity
What is the occupational limit for radiation per year?
20 m Sv
