C08 - Adiabatic Processes and Stability Flashcards
When a Parcel of Air has a natural tendency to rise it is said to be ‘____’?
Buoyant.
Rising air cools, causing ‘____’, clouds and maybe also ‘____’. These vertical air currents have great energy, rising in extremes at ‘____’ feet per minute. This can cause ‘____’ (4)?
- Condensation.
- Precipitation.
- 10,000.
- Severe Turbulence.
Define Adiabatic Process?
A Parcel of Air which can warm up or cool down without any external heat source or transfer of heat.
How does the Adiabatic Process work on a Parcel of Air?
By Compression or Expansion.
What does ALR stand for?
Adiabatic Lapse Rate.
Adiabatic Cooling happens when the Parcel of Air is?
Expanded.
Name two ways of Adiabatic Cooling?
- When a Parcel of Air expands the Temperature decreases internally.
- When a Parcel of Air rises the Atmospheric Pressure decreases with Height.
Air that is caused to rise in the Atmosphere will ‘____’ by ‘____’ (2)?
- Cool.
- Adiabatic Expansion.
Adiabatic Warming happens when the Parcel of Air is?
Compressed.
Name two ways of Adiabatic Warming by Compression?
- When a Parcel of Air compresses the Temperature increases.
- When a Parcel of Air descends the Atmospheric Pressure increases.
Air that is caused to descend in the Atmosphere ‘____’ by ‘____’ (2)?
- Warms.
- Adiabatic Compression.
What does DALR stand for and its rate in Temperature (3)?
- Dry Adiabatic Lapse Rate.
- 3°C per 1,000 ft.
- 1°C per 100m.
Dry Air is said to be?
Unsaturated air with less than 100% Humidity.
What does SALR stand for and its rate in Temperature (3)?
- Saturated Adiabatic Lapse Rate.
- 1.8°C per 1,000 ft.
- 0.6°C per 100m.
Saturated Air is said to be?
100% Humidity.
Name the effect and process which is linked to Saturated Air changing its Temperature by a smaller amount than Dry Air (2)?
- Latent Heat.
- Condensation.
The warmer the Saturated Air, the slower it ‘____’?
Cools.
Name four types of Atmospheric Stability?
- Absolute Stability.
- Absolute Instability.
- Conditional Stability.
- Neutral Stability.
Define Absolute Stability?
When a displaced Parcel of Air returns to its original position.
The Atmosphere is said to be stable whenever the ELR is ‘____’ DALR and SALR?
Less than.
True or False. The Lower the ELR, the greater the level of Stability?
True.
True or False. Inversions and Isotherms produce very stable Atmospheres? Why?
True. Because they produce low ELR.
Whenever Warm Air sits directly on top of Cold Air the Atmosphere will be?
Stable.
What type of Clouds are formed in Absolute Stability?
Stratiform.
What level of Precipitation can we expect in Absolute Stability?
Fairly light in Intensity.
What type of Precipitation can we expect in Absolute Stability (3)?
- Drizzle.
- Fine Rain.
- Snow or Snow Grains.
Why is Visibility Poor in Absolute Stability?
Because of trapped contaminants close to the surface.
What type of Weather due to Poor Visibility can we expect in Absolute Stability (2)?
- Haze.
- Fog or Mist.
What type of Turbulence can we expect in Absolute Stability?
Nil/Light Turbulence.
Define Absolute Instability?
When a displaced Parcel of Air continues in the direction of displacement.
The Atmosphere is said to be unstable whenever the ELR is ‘____’ DALR and SALR?
Greater than.
True or False. The Lower the ELR, the greater the level of Instability?
False. Greater the ELR.
When are high ELR’s typically found?
Over land masses in the summer.
Whenever Cold Air sits directly on top of Warm Air the Atmosphere will be?
Unstable.
What type of Clouds are formed in Absolute Instability?
Cumuliform.
What level of Precipitation can we expect in Absolute Instability?
Reasonably Intense.
What type of Precipitation can we expect in Absolute Instability?
Short Intense Showers.
Why can Visibility be both Good and Poor in Absolute Instability (2)?
- Good = Because contaminants are drawn upwards.
- Poor = Due to intense Showers.
What type of Turbulence can we expect in Absolute Instability?
Moderate/Severe Turbulence.
True or False. Absolute Stability and Instability happens regardless of the Parcel of Air being Dry or Saturated?
True.
During Conditional Instability Dry Air is said to be?
Stable.
During Conditional Instability Saturated Air is said to be?
Unstable.
The Atmosphere is said to be Conditional Instability whenever the ELR is ‘____’ DALR and SALR?
Between.
True or False. Conditional Instability happens regardless of the Parcel of Air being Dry or Saturated?
False. It depends on whether the Air is Dry or Saturated.
‘____’ is determined by the position of the LR line relative to the DALR and SALR?
Atmospheric Stability.
