MET 1 - The Atmosphere Flashcards
Density is directly proportional to, and inversely proportional to?
Directly Proportional to Pressure Inversely proportional to temperature
The mean density of the atmosphere is?
1225 gm/m^3
What is the average density of water vapour at sea level?
760gm/m^3
What is the calculation to approximate feet per hpa?
feet per hpa = 96T(K)/P(hpa)
The tropopause is the limit of?
Vertical movement of air and significant weather
What is the heights in M and FT and temperature of the tropopause in the Poles?
8km, 26 000ft and -45ºC
What is the heights in M and FT and temperature of the tropopause in the Mid Latitudes?
11km, 36 090ft and -56ºC
What is the heights in M and FT and temperature of the tropopause at the Equator?
16km, 52 500ft and -75ºC
The breaks between the tropopause show the location of what?
Polar and sub-tropical fronts
Airflow over hills will cause____.
A drop in atmospheric pressure
How is QNH calculated and what will it read while on the ground?
- QNH is QFE reduced to Sea Level using Standard Atmosphere
- On the ground it will read elevation
What does QFF measure, what is the QFF used on?
- QFF measurs the station pressure adjusted to MSL using actual met conditions.
- This information is used on hi level met charts
What is QNE and when is it used?
- QNE is touch down point of an aerodrome when 1013.2 is set on the altimeter.
- This is used at airfields that may be to high and the reading would be too low if QNE was used
What would the answer of 1013.2hpa - 998hpa be multiplied with to show difference in:
- m?
- ft?
- 8m
- 27ft
When will QNH & QFF be the same?
They will be the same in ISA conditions.
If the OAT is colder than ISA QFF will be more or less than QNH?
QFF will be less than QNH
Excet for ISA conditions when is QNH correct?
When the aircraft is on the ground
An area of low pressure rotates **clockwise/anti-clockwise **in the southern hemisphere.
Clockwise in the Southern Hemisphere
An area of High Pressure rotates anticlockwise/clockwise in the southern hemisphere.
Anti Clockwise in the southern hemisphere
An aircraft travelling from high pressure to low pressure would experience what barometric error?
The Aircrafts True Altitude would decrease
If you have a constant indicated altitude, have right hand drift (stbd drift) the true height would be?
The True height would decrease as you would be moving from high pressure to low pressure.
The Gas Composition of the atmosphere is?
- N2 = 78%
- O2 = 21%
- CO2, O3 and Other gasses = 1%
The process of heating the atmosphere is…
Suns short wave radiation gets absorbed by the earth and re-emmitted as long wave radiation that heats the lower levels of the atmosphere
If there is Constant Temperature, when Density increases pressure will?
Decrease
