Atmosphere

Question 1

Low Pressure Systems Flow of Air

Answer 1

Inward, upward, counterclockwise

Question 2

High Pressure Systems Flow of Air

Answer 2

Outward, Downward, and Clockwise

Question 3

Low Pressure System Weather Characteristics

Answer 3

Rising Air, which is conducive to cloudiness, precipitation and bad weather

Question 4

High Pressure System Weather Characteristics

Answer 4

Descending air which tends to favors dissipation of cloudiness and good weather

Question 5

Cold Front Occurence

Answer 5

Cold Front occurs when a mass of cold, dense, stable air advances and replaces a body of warmer air

Question 6

Occluded Front Occurence

Answer 6

A frontal occlusion occurs when a fast-moving cold front catches up with a slow-moving warm front.

Question 7

Types of Occluded Fronts

Answer 7

Cold front occlusion and warm front occlusion

Question 8

Warm Front Occurence

Answer 8

Boundary area formed when a warm air mass contacts and forms over a colder air mass

Question 9

Stationery Front Occurence

Answer 9

When the forces of two air masses are relatively equal, the boundary or front that separates them remains stationary and influences local weather for days. Typically mixture of both warm and cold fronts

Question 10

Cold Front General Weather Characteristics

Answer 10

Towering cumulus or cumulonimbus, heavy rain accompanied by lightning, thunder and/or hail; tornadoes possible. Poor visibility, winds variable and gusting; temperature/dew point and barometric pressure drop rapidly

Question 11

Warm Front General Weather Characteristics

Answer 11

Stratiform clouds, drizzle, low ceilings and poor visibility; variable winds, rise in temperature

Question 12

Weather Associated with a Front Depends on?

Answer 12

Amount of moisture available, degree of stability of the air that is forced upward, slope of the front, speed of frontal movement, and upper wind flow

Question 13

Trough (Line)

Answer 13

Elongated area of relatively low atmospheric pressure. A low or trough is an area of rising air. (At the surface when air converges into a low, it cant go outward against pressure gradient nor to the ground. It must go up.)

Question 14

What is rising air conducive of?

Answer 14

Cloudiness and precipitation; hence general association of low pressure and bad weather.

Question 15

Ridge (line)

Answer 15

Elongated area of relatively high atmospheric pressure. Air moving out of a high or ridge depletes quantity of air

Question 16

What is descending air conducive of?

Answer 16

Dissipation of clouds; hence association of high pressure and good weather

Question 17

What is standard temperature and pressure values for sea level?

Answer 17

15 Degrees Celsius and 29.92 Hg

Question 18

Isobars

Answer 18

Line on a weather chart which connects areas of equal or constant barometric pressure

Question 19

Isobar Spacing on Surface Weather Charts means what?

Answer 19

Spacing of isobars determines how steep or shallow a pressure gradient is.

Question 20

Closely spaced Isobars and not closely spaced isobars means what

Answer 20

Closed spaced means steep pressure gradient exists, higher wind speeds. Not closely spaced means shallow pressure gradient. Lighter wind speeds

Question 21

What causes winds aloft to float parallel to isobars?

Answer 21

Coriolis force

Question 22

Why do surface winds generally flow across isobars at an angle?

Answer 22

Surface friction

Question 23

Rate atmospheric pressures decreases with an increase in altitude

Answer 23

1’ Hg per 1,000 feet

Question 24

Dew Point

Answer 24

Temperature a sample of air must be cooled to attain the state of saturation.

Question 25

When temperature and dew point are close together (within 5’) what type of weather is likely

Answer 25

Visible moisture in the form of clouds, dew, or fog. Also ideal conditions for carburetor icing.

Question 26

Primary Factor determining type and vertical extent of clouds

Answer 26

Stability of the atmosphere

Question 27

What is the difference between stable and unstable atmosphere

Answer 27

The ability to resist vertical motion

Question 28

Stable atmosphere Vertical movement

Answer 28

Vertical movements are difficult, small vertical disturbances dampen out and disappear.

Question 29

Unstable atmosphere Vertical Movement

Answer 29

Small vertical air movements tend to become larger, resulting in turbulent airflow and convective activity.

Question 30

What does instability of atmosphere lead to?

Answer 30

Significant turbulence, extensive vertical clouds, and severe weather

Question 31

Effects of stable air on clouds, turbulence, preciptation and visibility

Answer 31

Stratiform clouds, smooth turbulence, steady precipitation, Fair to poor Visibility

Question 32

Effects of unstable air on clouds, turbulence, precipitation and visibility

Answer 32

Cumuliform Clouds, Rough Turbulence, Showery precipitation, Good visibility

Question 33

When Significant precipitation is occurring at the surface, how thick can you expect the clouds to be?

Answer 33

Requires clouds to be atleast 4,000 feet thick. The heavier the precipitation, thicker the clouds are likely to be

Question 34

During preflight planning, what type of meterological info should you be aware of in respect to icing?

Answer 34

Location of fronts, Cloud layers, Freezing Levels, Air temperature and pressure

Question 35

Location of Fronts (Icing)

Answer 35

Location, type, speed, and direction of movement

Question 36

Cloud layers (icing)

Answer 36

Location of cloud bases and tops, valuable for determing if you can climb above icing levels or descend beneath those layers into warmer airs. Refrence PIREPs and Area forecasts

Question 37

Freezing level (icing)

Answer 37

Important when determining how to avoid icing and how to exit icing conditions if accidentally encountered

Question 38

What is the definition of the term freezing level?

Answer 38

Lowest altitude in the atmosphere over a given location at which the air temperature reaches 0 Degrees celsius