Progress Test 1 Flashcards
(19 cards)
What effects the accuracy of weather forecasts?
The localisation of the weather forecast effects accuracy, the smaller the area the more difficult this becomes.
The troposphere is where most aviating is performed and where the weather is, what is the Tropopause?
The Tropopause is the top of the troposphere, this is higher at the equator than it is at the poles.
Can be up to 20, 000ft at the poles.
And up to 60, 000ft at the equator.
What is the stratosphere?
The part of the atmosphere which is above the weather and above most aviating.
True or False? The composition of gases in the atmosphere differs depending on the pressure, temperature or altitude.
False. The proportions of gases making up the atmosphere remains constant irrespective of the pressure, temperature or altitude.
What are the the compositions of gases in the atmosphere?
78% Nitrogen
21% Oxygen
1% of other gases.
Define Atmospheric Pressure.
Atmospheric pressure is the weight of the air at the surface caused by gravity.
What effects the atmospheric pressure?
Changes according to a variety of conditions:
Weather (High or Low pressure systems)
Water vapour content
True or False? As altitude increases, Pressure Decreases.
True.
In the Troposphere, what is the standard change of temperature for every 1000ft increase in altitude?
-1.98 degrees Celsius.
Name four reasons why a Standard Atmosphere is needed.
- For aircraft performance calculations
- For standard separation of commercial traffic at altitude.
- For expected temperatures at altitude.
- For a base line to calculate forecasts.
At sea level what is the standard atmosphere for density, temperature and pressure?
Density is 1.225kg/m3
Temperature is 15 degrees Celsius
Pressure is 1013.2 hpa
What is the standard change of pressure?
Pressure reduction of -1 hpa for every 30ft increase in altitude (up to 20, 000ft).
What is the conversion of Hectopascal to Inches mercury and Inches mercury to Hectopascal?
1 hectopascal = 0.0295 Inches mercury
1 inches mercury = 33.86 hectopascal.
What is the Celscius to fahrenheit calculation?
(x9 / 5) + 32
What is 100 degrees fahrenheit into Celsius?
37.7 degrees Celsius.
Is water vapour more or less dense than dry air?
Less dense.
Does water vapour content in the atmosphere stay constant?
No, it varies.
Humid air weighs less than dry air, what pressure system is humid air associated with?
Low Pressure Systems.
Is the relationship between altitude and pressure linear or non-linear?
Linear means it is progresses straight at the same rate, whereas non-linear does not progress at the same rate.
Non-linear.
