Meteorology

Question 1

What does MSL stand for?

Answer 1

Mean Sea Level.

MSL is the average level of one or more of the Earth’s oceans. From which heights such as elevation can be measured.

Question 2

Roughly, what is the atmospheric pressure at MSL?

Answer 2

1000 hPa

Question 3

What are the major constituents of the atmosphere?

Answer 3

Gases and vapours (nitrogen, oxygen, water vapour, rare gases)

Liquid water and ice (clouds)

Solid matter (dust, smoke and salt)

Question 4

Why are solid atmospheric particles important for condensation?

Answer 4

Small quantities of solid particles provide the essential nuclei for the condensation process to begin.

Question 5

What is the Troposphere?

Answer 5

The Troposphere is the lowest zone of the atmosphere. Almost all atmospheric water (hence weather) is in this zone.

Question 6

What is the Stratosphere?

Answer 6

The Stratosphere is the zone above the troposphere.

There are no storms or turbulence to mix up the air, so cold, heavy air is at the bottom and warm, light air is at the top. It is 22 miles (35 kilometers) thick and is where the ozone is located

Question 7

What is the boundary between the Troposphere and Stratosphere called?

Answer 7

Tropopause.

This boundary is usually easily distinguishable on a temp/heigh graph.

Question 8

Why is the tropopause important for aircraft operations?

Answer 8

1. Clouds rarely occur above the tropopause.
2. Wind speed reaches a max near (usually below) the tropopause.
3. Condesation trails may occur near the tropopause but cease above.
4. Severe turbulence may occur near the tropopause.
5. Turbojet engines are more efficient in low temp zones at tropopause (no advantage to be gained climbing above).

Question 9

What threats are possible at the tropopause?

Answer 9

Severe turbulence may be encountered near the tropopause.

Question 10

What is the approximate heights of the tropopause above? :

1. The Poles
2. UK
3. Equator

Answer 10

The Poles - 5 miles (25,000 ft)

UK - 7 miles (35,000 ft)

Equator - 11 miles (55,000 ft)

Question 11

What 4 factors make atmospheric temperature of importance to a professional aviator?

Answer 11

1. It has effects on aircraft icing problems.
2. It has important effects on engine performance.
3. It governs corrections applued to instruments such as the ASI and Altimeter.
4. High speed flight produces ‘kinetic heating’, air temp surround the airframe will affect dispersion rate of this heat.

Question 12

What barriers absorb/reflect solar radiation (SR) before it reaches the surface of the Earth?

Answer 12

1. Much SR is absorbed by gases (oxygen, ozone) in the high atmosphere.
2. Some SR is absorbed by water vapour and clouds in the lower atmosphere.
3. All other SR is absorbed by the Earth’s surface.

Question 13

What is Terrestrial Radiation?

Answer 13

Terrestrial Radiation is produced by the Earth at low temperature, low intensity and long wavelengths.