ATPL Meteorology exam QUESTIONS AND
CORRECT DETAILED ANSWERS
What is the boundary layer between troposphere and stratosphere called? -
ANSWER>>Tropopause.
¡How does the height of the tropopause normally vary with latitude in the northern
hemisphere? - ANSWER>>It decreases from south to north
Which one of the following statements applies to the tropopause? - ANSWER>>It separates the
troposphere from the stratosphere
The thickness of the troposphere varies with - ANSWER>>latitude
What is the approximate composition of the dry air by volume in the troposphere? -
ANSWER>>21 % oxygen, 78 % nitrogen, and the rest other gasses
Which layer of the atmosphere contains more than 90 per cent of all water vapour? -
ANSWER>>Troposphere
Going from the equator to the north pole, the altitude of the tropopause: -
ANSWER>>decreases and its temperature increases
The troposphere is the - ANSWER>>part of the atmosphere below the tropopause
The tropopause is a level at which - ANSWER>>temperature ceases to fall with increasing height
The tropopause is lower - ANSWER>>over the North Pole than over the equator
The height and the temperature of the tropopause are respectively in the order of -
ANSWER>>16 km and -75°C over the equator
The troposphere - ANSWER>>has a greater vertical extent above the equator than above the
poles
Which statement concerning the tropopause is correct? - ANSWER>>The layer just above the
tropopause is absolutely stable
,Considering the North Atlantic area north of 60°N during winter, the mean height of the
tropopause is approximately: - ANSWER>>29000'
Considering the North Atlantic at latitude 50°N during winter, the mean height of the
tropopause is approximately: - ANSWER>>31000'
"The temperature at FL 140 is -12°C. - ANSWER>>
What will the temperature be at FL 110 if the ICAO standard lapse rate is applied?" -
ANSWER>>-6°C
Which of the following is a common cause of ground or surface temperature inversion ? -
ANSWER>>Terrestrial radiation on a clear night with no or very light winds.
Convective activity over land in mid-latitudes is greatest in - ANSWER>>summer in the
afternoon.
The 0° C isotherm is forecast to be at FL 50. At what FL would you expect a temperature of -6°
C? - ANSWER>>FL 80
In an air mass with no clouds the surface temperature is 15°C and the temperature at 1000 m /
AGL is 13°C. This layer of air is: - ANSWER>>stable
What characteristic is associated with a temperature inversion? - ANSWER>>Stability
The temperature at FL 80 is +6°C. What will the temperature be at FL 130 if the ICAO standard
lapse rate is applied ? - ANSWER>>-4°C
The temperature at FL 110 is -5°C. What will the temperature be at FL 50 if the ICAO standard
lapse rate is applied ? - ANSWER>>+7°C
A temperature of +15°C is recorded at an altitude of 500 metres above sea level. If the vertical
temperature gradient is that of a standard atmosphere, what will the temperature be at the
summit of a mountain, 2500 metres above sea level? - ANSWER>>+2°C
An air temperature of -15°C at the 700 hPa level over central Europe in summer is: -
ANSWER>>Low
,An inversion is a layer of air in which the temperature - ANSWER>>increases with height
An isothermal layer is a layer of air in which the temperature - ANSWER>>remains constant
with height
An inversion is a layer of air which is: - ANSWER>>absolutely stable
The environmental lapse rate in an actual atmosphere - ANSWER>>varies with time
The dry adiabatic lapse rate has a value of - ANSWER>>1°C/100m
The dry adiabatic lapse rate - ANSWER>>has a constant fixed value
An air mass is called stable when - ANSWER>>the vertical motion of rising air tends to become
weaker and disappears
Advection is: - ANSWER>>horizontal motion of air
The radiation of the sun heats - ANSWER>>the surface of the earth, which heats the air in the
troposphere
The diurnal variation in temperature is largest when - ANSWER>>the sky is clear and the wind is
weak
When in the upper part of a layer and warm air is advected in, the: - ANSWER>>stability
increases in the layer
An inversion is - ANSWER>>an increase of temperature with height
In still air the temperature decreases at an average of 1.2°C per 100 m increase in altitude. This
temperature change is called: - ANSWER>>environmental lapse rate
A significant inversion at low height is a characteristic of: - ANSWER>>nocturnal radiation
From which of the following pieces of information can the stability of the atmosphere be
derived? - ANSWER>>Environmental lapse rate
, Convective weather phenomena include - ANSWER>>thunderstorms, hail, tornadoes, wind
gusts, heavy showers, lightning strikes
The stability in a layer increases by advection of - ANSWER>>cold air in the lower part
Which is true of the temperature at the tropopause? - ANSWER>>It is higher in polar regions
than in equatorial regions
Absolute instability is said to exist whenever the environmental lapse rate - ANSWER>>exceeds
the dry adiabatic lapse rate
Absolute instability in the atmosphere will occur when the environmental lapse rate is -
ANSWER>>greater than both saturated adiabatic lapse rate and dry adiabatic lapse rate
For both saturated and unsaturated air instability will occur when the -
ANSWER>>environmental lapse rate is greater than both dry adiabatic lapse rate and saturated
adiabatic lapse rate
In the lower levels of the atmosphere when the environmental lapse rate is greater than
saturated adiabatic lapse rate but less than dry adiabatic lapse rate - the air mass is described
as being: - ANSWER>>conditionally unstable
Surface-based temperature inversions are common during - ANSWER>>cloud-free nights in
winter when the ground is dry
The temperature at the surface is given as +15°C and at 4000 FT it is +9°C, the state of this layer
is said to be: - ANSWER>>stable
Surface temperature inversions are frequently generated by - ANSWER>>terrestrial radiation
on a calm clear night
Around Paris on January 3rd at 1800 UTC, the surface temperature, under shelter, is +3°C. The
sky is covered by 8 oktas of stratus. QNH is 1033 hPa. If the sky is covered all night, the
minimum temperature of the night of January 3rd to January 4th should be - ANSWER>>slightly
below +3°C.
On a clear sky, continental ground surface, wind calm, the minimum temperature is reached
approximately: - ANSWER>>half an hour after sunrise
CORRECT DETAILED ANSWERS
What is the boundary layer between troposphere and stratosphere called? -
ANSWER>>Tropopause.
¡How does the height of the tropopause normally vary with latitude in the northern
hemisphere? - ANSWER>>It decreases from south to north
Which one of the following statements applies to the tropopause? - ANSWER>>It separates the
troposphere from the stratosphere
The thickness of the troposphere varies with - ANSWER>>latitude
What is the approximate composition of the dry air by volume in the troposphere? -
ANSWER>>21 % oxygen, 78 % nitrogen, and the rest other gasses
Which layer of the atmosphere contains more than 90 per cent of all water vapour? -
ANSWER>>Troposphere
Going from the equator to the north pole, the altitude of the tropopause: -
ANSWER>>decreases and its temperature increases
The troposphere is the - ANSWER>>part of the atmosphere below the tropopause
The tropopause is a level at which - ANSWER>>temperature ceases to fall with increasing height
The tropopause is lower - ANSWER>>over the North Pole than over the equator
The height and the temperature of the tropopause are respectively in the order of -
ANSWER>>16 km and -75°C over the equator
The troposphere - ANSWER>>has a greater vertical extent above the equator than above the
poles
Which statement concerning the tropopause is correct? - ANSWER>>The layer just above the
tropopause is absolutely stable
,Considering the North Atlantic area north of 60°N during winter, the mean height of the
tropopause is approximately: - ANSWER>>29000'
Considering the North Atlantic at latitude 50°N during winter, the mean height of the
tropopause is approximately: - ANSWER>>31000'
"The temperature at FL 140 is -12°C. - ANSWER>>
What will the temperature be at FL 110 if the ICAO standard lapse rate is applied?" -
ANSWER>>-6°C
Which of the following is a common cause of ground or surface temperature inversion ? -
ANSWER>>Terrestrial radiation on a clear night with no or very light winds.
Convective activity over land in mid-latitudes is greatest in - ANSWER>>summer in the
afternoon.
The 0° C isotherm is forecast to be at FL 50. At what FL would you expect a temperature of -6°
C? - ANSWER>>FL 80
In an air mass with no clouds the surface temperature is 15°C and the temperature at 1000 m /
AGL is 13°C. This layer of air is: - ANSWER>>stable
What characteristic is associated with a temperature inversion? - ANSWER>>Stability
The temperature at FL 80 is +6°C. What will the temperature be at FL 130 if the ICAO standard
lapse rate is applied ? - ANSWER>>-4°C
The temperature at FL 110 is -5°C. What will the temperature be at FL 50 if the ICAO standard
lapse rate is applied ? - ANSWER>>+7°C
A temperature of +15°C is recorded at an altitude of 500 metres above sea level. If the vertical
temperature gradient is that of a standard atmosphere, what will the temperature be at the
summit of a mountain, 2500 metres above sea level? - ANSWER>>+2°C
An air temperature of -15°C at the 700 hPa level over central Europe in summer is: -
ANSWER>>Low
,An inversion is a layer of air in which the temperature - ANSWER>>increases with height
An isothermal layer is a layer of air in which the temperature - ANSWER>>remains constant
with height
An inversion is a layer of air which is: - ANSWER>>absolutely stable
The environmental lapse rate in an actual atmosphere - ANSWER>>varies with time
The dry adiabatic lapse rate has a value of - ANSWER>>1°C/100m
The dry adiabatic lapse rate - ANSWER>>has a constant fixed value
An air mass is called stable when - ANSWER>>the vertical motion of rising air tends to become
weaker and disappears
Advection is: - ANSWER>>horizontal motion of air
The radiation of the sun heats - ANSWER>>the surface of the earth, which heats the air in the
troposphere
The diurnal variation in temperature is largest when - ANSWER>>the sky is clear and the wind is
weak
When in the upper part of a layer and warm air is advected in, the: - ANSWER>>stability
increases in the layer
An inversion is - ANSWER>>an increase of temperature with height
In still air the temperature decreases at an average of 1.2°C per 100 m increase in altitude. This
temperature change is called: - ANSWER>>environmental lapse rate
A significant inversion at low height is a characteristic of: - ANSWER>>nocturnal radiation
From which of the following pieces of information can the stability of the atmosphere be
derived? - ANSWER>>Environmental lapse rate
, Convective weather phenomena include - ANSWER>>thunderstorms, hail, tornadoes, wind
gusts, heavy showers, lightning strikes
The stability in a layer increases by advection of - ANSWER>>cold air in the lower part
Which is true of the temperature at the tropopause? - ANSWER>>It is higher in polar regions
than in equatorial regions
Absolute instability is said to exist whenever the environmental lapse rate - ANSWER>>exceeds
the dry adiabatic lapse rate
Absolute instability in the atmosphere will occur when the environmental lapse rate is -
ANSWER>>greater than both saturated adiabatic lapse rate and dry adiabatic lapse rate
For both saturated and unsaturated air instability will occur when the -
ANSWER>>environmental lapse rate is greater than both dry adiabatic lapse rate and saturated
adiabatic lapse rate
In the lower levels of the atmosphere when the environmental lapse rate is greater than
saturated adiabatic lapse rate but less than dry adiabatic lapse rate - the air mass is described
as being: - ANSWER>>conditionally unstable
Surface-based temperature inversions are common during - ANSWER>>cloud-free nights in
winter when the ground is dry
The temperature at the surface is given as +15°C and at 4000 FT it is +9°C, the state of this layer
is said to be: - ANSWER>>stable
Surface temperature inversions are frequently generated by - ANSWER>>terrestrial radiation
on a calm clear night
Around Paris on January 3rd at 1800 UTC, the surface temperature, under shelter, is +3°C. The
sky is covered by 8 oktas of stratus. QNH is 1033 hPa. If the sky is covered all night, the
minimum temperature of the night of January 3rd to January 4th should be - ANSWER>>slightly
below +3°C.
On a clear sky, continental ground surface, wind calm, the minimum temperature is reached
approximately: - ANSWER>>half an hour after sunrise
