CPAER METEOROLOGY QUESTIONS AND ANSWERS
What is the primary driver of weather? - Answers -Uneven heating of the surface of the
earth
In a standard atmosphere the environmental lapse rate is - Answers -2º per 1,000ft
The dry adiabatic lapse rate is - Answers -3º per 1,000ft
The wet adiabatic lapse rate is - Answers -1.5º per 1,000ft
A stable atmosphere occurs when the environmental lapse rate is - Answers -Shallow or
negative
An unstable atmosphere occurs when the environmental lapse rate is - Answers -
Steeper than both the wet and dry adiabatic lapse rates
A potentially unstable atmosphere occurs when the environmental lapse rate is -
Answers -Somewhere between the dry an wet adiabatic lapse rates
ISA - Answers -15º and pressure at sea level of 29.92" (1013.2hpa)
The average height of the tropopause is - Answers -36,000ft
For every 1,000ft climbed, mercury drops approximately - Answers -1"
Relative humidity - Answers -The amount of water in the air relative to the maximum it
can hold at given temperature and pressure
Dewpoint - Answers -The temperature at which condensation begins
Is humid air or dry air more dense? - Answers -Dry air
Convection - Answers -Vertical movement of air
Advection - Answers -Horizontal movement of air
Deposition - Answers -When gas changes *directly* to a solid
Few clouds cover - Answers -0.1 to 2/8ths of the sky
Scattered clouds cover - Answers -3/8ths to 4/8ths of the sky
Broken clouds cover - Answers -5/8ths to 7/8ths of the sky
Overcast clouds cover - Answers -8/8ths of the sky
, What is visibility in mist? - Answers -5/8 SM or greater
What is visibility in fog? - Answers -Less than 5/8 SM
What is ceiling described as? - Answers -The lowest layer of broken or overcast clouds
At what rate will dewpoint drop as pressure decreases? - Answers -0.5º per 1,000ft
Cloud base calculation - Answers -Difference between air temperature at the surface
and dew point, divided by 3
Anabatic winds - Answers -Arise when a mountain or hillside is exposed to direct
sunlight and is heated, causing warm air to rise (blows up mountain)
Katabatic winds - Answers -Arise when heat is radiated off mountain or hill slopes *at
NIGHT*, causing cooled air to sink down (blows down mountain)
Mountain waves form - Answers -When wind blows over terrain leaving vorticies in its
wake
Downdrafts in mountain waves can reach vertical speeds of - Answers -5,000 FPM
Radiation fog forms - Answers -On clear nights with a very gentle wind when the earth
loses heat due to radiation cooling air temperature to the dewpoint
Advection fog forms when - Answers -Air flows from a warm surface to a cool surface,
may form with winds up to 15kts
Frontal fog is associated with - Answers -A warm/cold front
Frontal fog forms when - Answers -Rain falling from the warm air saturates the cold air
Arctic sea smoke forms when - Answers -Cold air flows over relatively warm water
Upslope fog forms when - Answers -Air forced to rise cools adiabatically, if upslope and
moisture content is sufficient the dewpoint will be reached resulting in condensation
Airmass - Answers -A body of air with substantially the same properties of temperature,
humidity, stability, and tropopause height
Continental Arctic cA - Answers -Generally very dry, very cold and stable with
tropopause at low altitude
Maritime Arctic mA - Answers -Generally moist, cold, unstable in the lower layers with
tropopause at low altitude
What is the primary driver of weather? - Answers -Uneven heating of the surface of the
earth
In a standard atmosphere the environmental lapse rate is - Answers -2º per 1,000ft
The dry adiabatic lapse rate is - Answers -3º per 1,000ft
The wet adiabatic lapse rate is - Answers -1.5º per 1,000ft
A stable atmosphere occurs when the environmental lapse rate is - Answers -Shallow or
negative
An unstable atmosphere occurs when the environmental lapse rate is - Answers -
Steeper than both the wet and dry adiabatic lapse rates
A potentially unstable atmosphere occurs when the environmental lapse rate is -
Answers -Somewhere between the dry an wet adiabatic lapse rates
ISA - Answers -15º and pressure at sea level of 29.92" (1013.2hpa)
The average height of the tropopause is - Answers -36,000ft
For every 1,000ft climbed, mercury drops approximately - Answers -1"
Relative humidity - Answers -The amount of water in the air relative to the maximum it
can hold at given temperature and pressure
Dewpoint - Answers -The temperature at which condensation begins
Is humid air or dry air more dense? - Answers -Dry air
Convection - Answers -Vertical movement of air
Advection - Answers -Horizontal movement of air
Deposition - Answers -When gas changes *directly* to a solid
Few clouds cover - Answers -0.1 to 2/8ths of the sky
Scattered clouds cover - Answers -3/8ths to 4/8ths of the sky
Broken clouds cover - Answers -5/8ths to 7/8ths of the sky
Overcast clouds cover - Answers -8/8ths of the sky
, What is visibility in mist? - Answers -5/8 SM or greater
What is visibility in fog? - Answers -Less than 5/8 SM
What is ceiling described as? - Answers -The lowest layer of broken or overcast clouds
At what rate will dewpoint drop as pressure decreases? - Answers -0.5º per 1,000ft
Cloud base calculation - Answers -Difference between air temperature at the surface
and dew point, divided by 3
Anabatic winds - Answers -Arise when a mountain or hillside is exposed to direct
sunlight and is heated, causing warm air to rise (blows up mountain)
Katabatic winds - Answers -Arise when heat is radiated off mountain or hill slopes *at
NIGHT*, causing cooled air to sink down (blows down mountain)
Mountain waves form - Answers -When wind blows over terrain leaving vorticies in its
wake
Downdrafts in mountain waves can reach vertical speeds of - Answers -5,000 FPM
Radiation fog forms - Answers -On clear nights with a very gentle wind when the earth
loses heat due to radiation cooling air temperature to the dewpoint
Advection fog forms when - Answers -Air flows from a warm surface to a cool surface,
may form with winds up to 15kts
Frontal fog is associated with - Answers -A warm/cold front
Frontal fog forms when - Answers -Rain falling from the warm air saturates the cold air
Arctic sea smoke forms when - Answers -Cold air flows over relatively warm water
Upslope fog forms when - Answers -Air forced to rise cools adiabatically, if upslope and
moisture content is sufficient the dewpoint will be reached resulting in condensation
Airmass - Answers -A body of air with substantially the same properties of temperature,
humidity, stability, and tropopause height
Continental Arctic cA - Answers -Generally very dry, very cold and stable with
tropopause at low altitude
Maritime Arctic mA - Answers -Generally moist, cold, unstable in the lower layers with
tropopause at low altitude
