The Atmosphere Flashcards
(34 cards)
What is the atmosphere often referred to in aviation literature?
An invisible ocean of air in which man lives and pilots navigate.
Why is weather a vital concern for pilots?
Because it presents hazards like fog, ice formation, thunderstorms, and line squalls which affect flight safety.
What hazards are mentioned that present unusual challenges to flying?
Fog, ice formation, thunderstorms, and line squalls.
What has been established to minimize hazards to air navigation?
A worldwide meteorological organization that collects, analyzes, and broadcasts weather information.
What must pilots possess to deal with sudden changing conditions in weather?
“Weather sense” – the ability to understand and respond to changing weather conditions.
What is the composition of the atmosphere up to 250,000 feet?
Approximately 78% nitrogen, 21% oxygen, and the remainder argon, carbon dioxide, other gases, and water vapour.
Which component of the atmosphere is most important for weather?
Water vapour.
Why is water vapour unpredictable in its behaviour?
Because its amount varies constantly and it’s hard to predict when it will condense into a visible form.
How do microscopic impurities in the lower atmosphere affect aviation?
They can reduce visibility and assist in the condensation process.
Why does the upper atmosphere appear cobalt blue to black?
Because it lacks dust and impurities to reflect sunlight.
What is the weight of a square inch column of air at sea level?
Approximately 14.7 lbs.
What are the three key properties of the atmosphere?
Mobility, capacity for expansion, and capacity for compression.
What happens when air is forced to rise?
It expands due to lower pressure, cools, and may lead to condensation and cloud formation.
What is the result of sinking air?
It compresses, its volume decreases, and its temperature rises.
What are the four distinct layers of the atmosphere?
Troposphere, stratosphere, mesosphere, and thermosphere.
What is the height range of the troposphere?
About 28,000 feet at the poles to 54,000 feet at the equator.
Why does most weather occur in the troposphere?
Because of the presence of water vapour and strong vertical currents from solar heating.
What is found in the upper regions of the troposphere?
Jet streams – strong, fast-moving, complex winds.
What marks the top of the troposphere?
The tropopause.
What causes the temperature increase in the stratosphere?
The absorption of ultraviolet rays by the ozone layer.
What gas layer is found in the stratosphere?
Ozone.
Where do meteorites typically burn up in the atmosphere?
In the mesosphere.
What is the coldest layer of the atmosphere and what is the temperature?
The mesosphere, with temperatures dropping to about -100°C.
What is the name of the boundary where temperature bottoms out in the mesosphere?
The mesopause.
