NIFE WEATHER ACTUAL QUESTIONS AND
ANSWERS WITH COMPLETE SOLUTION
What are the percentages of gases in pure, dry air?
78% nitrogen
21% oxygen
1% other gases
What percent is water vapor in the atmosphere?
0-5% by volume
What is the troposphere?
Layer adjacent to the Earth's surface
Where does all weather occur?
Troposphere
In the troposhpere, what happens to the temperature with an increase in
altitude?
Temperature decreases
What are the winds like in the troposphere?
Winds are light near the Earths surface and increase with altitude
Where is the troposphere? (height)
Average height of 36000 MSL
What is the moisture content in the troposphere?
Large amounts of moisture and condensation
Is the troposphere higher in the summer or in the winter?
Higher in the summer. Think that the air is heating up and rising the troposphere
What is the tropopause?
Transition zone between the troposphere and stratosphere
What happens to temperature with an increase in altitude in the tropopause?
Decrease?
Constant
Constant
Where do the strongest winds occur?
In the tropopause
What is atmospheric pressure? What is atmospheric pressure also known as?
Pressure exerted on a surface by the atmosphere due to the weight of the column of
air directly above that surface
As altitude increases, what happens to pressure?
Decreases always
What are the two standard units of pressure?
Inches of mercury (in-Hg)
Millibars (mb)
What is station pressure?
Atmospheric pressure measured directly at an airfield
Which is greater, station pressure or sea level pressure?
Station pressure...... stations wont be in the sea
What is Sea Level Pressure?
Pressure that would be measured if the station was at MSL
How do stations report pressure regardless of location?
In Sea Level Pressure
, What is Atmospheric circulation?
Earth is constantly heated and cooled as it rotates. This causes ascending and
descending air
What are the two ways atmospheric circulation moves air?
Ascending and descending currents
What causes Atmospheric circulation?
Wind trying to go from high pressure to low pressure. Due to the Coriolis Force
What are Pressure Gradients?
Spacing of isobars that represent a change in pressure over a horizontal distance.
When is a Pressure Gradient Force (PGF) strong?
When isobars are close together
What is the initiating force for all winds?
Pressure Gradient Force
What pressure gradient force is associated with slower winds?
Wide spaced PGF
What is standard atmosphere?
Standard day at sea level conditions
29.92 in-Hg
15 C
What is Lapse rate?
Decrease in atmospheric temperature with increasing altitude
What is the average temperature lapse rate?
2C/1000ft
What is an isothermal lapse rate?
Temperature is the same at different altitudes
What is an air mass?
Large body of air with uniform temperature and moisture conditions in a horizontal
plane
How are Air masses named?
According to their location, moisture content and temperature relative to the ground
What is Dew Point Temperature?
Temperature at which saturation occurs
What is dew point?
direct indication of how much moisture is in the air
What is dew point depression?
Difference between the air temperature and the dew point temperature
What is saturation?
When the air contains the maximum amount of moisture that it can hold for a certain
temperature
What is Relative Humidity (RH)?
The percent of saturation in the air
Explain the effect a change in pressure has on the altimeter
"High to Low, Look out below"
-Aircraft is going to be lower than indicated on the altimeter when going from a high
pressure to a lower pressure
"Low to High, plenty of sky"
-Aircraft is going to be higher than indicated on the altimeter when going from a low
pressure to a higher one
What is indicated altitude?
ANSWERS WITH COMPLETE SOLUTION
What are the percentages of gases in pure, dry air?
78% nitrogen
21% oxygen
1% other gases
What percent is water vapor in the atmosphere?
0-5% by volume
What is the troposphere?
Layer adjacent to the Earth's surface
Where does all weather occur?
Troposphere
In the troposhpere, what happens to the temperature with an increase in
altitude?
Temperature decreases
What are the winds like in the troposphere?
Winds are light near the Earths surface and increase with altitude
Where is the troposphere? (height)
Average height of 36000 MSL
What is the moisture content in the troposphere?
Large amounts of moisture and condensation
Is the troposphere higher in the summer or in the winter?
Higher in the summer. Think that the air is heating up and rising the troposphere
What is the tropopause?
Transition zone between the troposphere and stratosphere
What happens to temperature with an increase in altitude in the tropopause?
Decrease?
Constant
Constant
Where do the strongest winds occur?
In the tropopause
What is atmospheric pressure? What is atmospheric pressure also known as?
Pressure exerted on a surface by the atmosphere due to the weight of the column of
air directly above that surface
As altitude increases, what happens to pressure?
Decreases always
What are the two standard units of pressure?
Inches of mercury (in-Hg)
Millibars (mb)
What is station pressure?
Atmospheric pressure measured directly at an airfield
Which is greater, station pressure or sea level pressure?
Station pressure...... stations wont be in the sea
What is Sea Level Pressure?
Pressure that would be measured if the station was at MSL
How do stations report pressure regardless of location?
In Sea Level Pressure
, What is Atmospheric circulation?
Earth is constantly heated and cooled as it rotates. This causes ascending and
descending air
What are the two ways atmospheric circulation moves air?
Ascending and descending currents
What causes Atmospheric circulation?
Wind trying to go from high pressure to low pressure. Due to the Coriolis Force
What are Pressure Gradients?
Spacing of isobars that represent a change in pressure over a horizontal distance.
When is a Pressure Gradient Force (PGF) strong?
When isobars are close together
What is the initiating force for all winds?
Pressure Gradient Force
What pressure gradient force is associated with slower winds?
Wide spaced PGF
What is standard atmosphere?
Standard day at sea level conditions
29.92 in-Hg
15 C
What is Lapse rate?
Decrease in atmospheric temperature with increasing altitude
What is the average temperature lapse rate?
2C/1000ft
What is an isothermal lapse rate?
Temperature is the same at different altitudes
What is an air mass?
Large body of air with uniform temperature and moisture conditions in a horizontal
plane
How are Air masses named?
According to their location, moisture content and temperature relative to the ground
What is Dew Point Temperature?
Temperature at which saturation occurs
What is dew point?
direct indication of how much moisture is in the air
What is dew point depression?
Difference between the air temperature and the dew point temperature
What is saturation?
When the air contains the maximum amount of moisture that it can hold for a certain
temperature
What is Relative Humidity (RH)?
The percent of saturation in the air
Explain the effect a change in pressure has on the altimeter
"High to Low, Look out below"
-Aircraft is going to be lower than indicated on the altimeter when going from a high
pressure to a lower pressure
"Low to High, plenty of sky"
-Aircraft is going to be higher than indicated on the altimeter when going from a low
pressure to a higher one
What is indicated altitude?
