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WorksheetsMet1 topics 1-6 18/12/18
Total questions: 38
Worksheet time: 28mins
A parcel of air has a temperature of 15 degrees C and a dew point of 10 degrees C. What is its relative humidity, approximately?
75%
90%
50%
65%
What is the significance to aviation of breaks or steps in the tropopause?
They indicate the position of strong upper winds
They indicate the position and movement of tropical revolving storms
They indicate the position and movement of anticyclones
They indicate light winds at the surface (the ‘horse latitudes’)
An outside air temperature of -35°C is measured while cruising at FL 200. What is the temperature deviation from the ISA at this level?
10°C colder than ISA.
10°C warmer than ISA.
5°C warmer than ISA.
5°C colder than ISA
An aircraft flying at FL 45 (OAT 6°C) obtains a reading of 1860 ft on its radio altimeter (ground elevation 3090 ft). What is the value of the QNH, to the nearest hPa, at that point?
1030
1042
1013
996
An aircraft is flying at FL 80. The local QNH is 1000 hPa. After the second altimeter has been adjusted to the local QNH, the reading will be approximately:
8000 ft
7650 ft
8350 ft
8600 ft
What is meant by the term "altitude"?
The vertical distance of a level or a point measured from the earth's surface.
The vertical distance of a level or a point measured from mean sea level.
The vertical distance of a level or a point measured from the aerodrome reference point.
Altimeter indication when altimeter subscale is set to present QFE.
Which one of the following describes normal conditions?
Temperature decreases with height in the troposphere
Temperature decreases at a similar rate in the troposphere as in the stratosphere
Temperature increases with height in the troposphere
Temperature decreases with height in the stratosphere
Which of the following types of jet streams can be observed all year round?
Equatorial jet stream / polar front jet stream.
Arctic jet stream / subtropical jet stream.
Subtropical jet stream / polar front jet stream.
Equatorial jet stream / arctic jet stream.
In relation to the Polar front jet stream, the greatest rate of wind shear is most likely to occur:
On the tropical side of the core
8000 ft or more above the core
On the polar side of the core
Below 15000 ft/amsl
The easterly jet is a jet stream that occurs:
During the whole year in the Southern Hemisphere
Only in the winter of the Northern Hemisphere at approx. 30 000 ft
Only in the summer of the Northern Hemisphere at approx. 45 000 ft
During the whole year in the Northern Hemisphere
The most frequent wind direction in a valley near the ground caused by thermal effects is:
Up the valley during daylight hours.
Down the valley during daylight as much as at night.
Down the valley during daylight hours.
Up the valley at night.
What relationship exists between the wind at 3000 feet and the surface wind?
The wind at 3000 ft is parallel to the isobars and the surface wind direction is across the isobars toward the low pressure and the surface wind is weaker.
They are practically the same, except when eddies exist, caused by obstacles
The surface wind is veered compared to the wind at 3000 feet and is usually weaker.
They have the same direction, but the surface wind is weaker, caused by friction
Wind is caused by
The movements of fronts
Horizontal pressure differences
Friction between the air and the ground
The rotation of the earth
For a similar pressure gradient and air density, the geostrophic wind speed will be:
The same at all latitudes north or south of 15°
Greater at 30°N than at 60°N
Equivalent to gradient wind ± thermal component
Greater at 60°N than at 30°N
(Refer to image)
What name is given to the jet stream lying across India (A) ?
Subtropical jet stream.
Tropical jet stream.
Polar front jet stream.
Arctic jet stream.
In the Northern Hemisphere at 5000 ft/AGL a south-westerly wind is blowing. The surface wind at the same location is a southerly wind. What is the primary reason of difference between these two wind directions?
A strong pressure gradient at higher altitudes.
Stronger Coriolis force at the surface.
Friction between the wind and the surface.
The influence of warm air at the lower altitude.
In the Northern Hemisphere the wind at the surface blows
Counter-clockwise around, and toward the centre of, a low pressure area
Counter-clockwise around, and away from the centre of, a high pressure area.
Clockwise around, and away from the centre of, a low pressure area
From a low pressure area to a high pressure area
Consider a parcel of air being forced upwards in the atmosphere. The lapse rate of the surrounding air is less than the saturated adiabatic lapse rate. After the initial force is no longer effective, the parcel of air
Will become conditionally unstable.
Will tend to ascend further.
Will tend to remain at the new altitude.
Will tend to descend to its original altitude.
The decrease in temperature, per 100 metres, in a saturated rising parcel of air at lower levels of the atmosphere is approximately:
1.5°c
0.6°c
1.8°c
1.98°c
If a saturated air mass descends down a slope its temperature increases at:
A lower rate than in dry air, as evaporation absorbs heat
The same rate as if the air mass were dry
A lower rate than in dry air, as condensation gives out heat
A higher rate than in dry air, as it gives up latent evaporation heat
Which of the following cloud genera may extend over the low, middle and high cloud levels?
Ac
Cb
Ci
St
Which of the following cloud types is found at high levels?
As
Ci
Cu
Sc
Altostratus clouds are classified as:
Medium level clouds
High level clouds
Low level clouds
Convective clouds
Which of the following are medium level clouds ?
Cirrocumulus and cirrostratus
Cumulonimbus
All convective clouds
Altostratus and altocumulus
Radiation fog most frequently occurs in:
High pressure systems over sea.
Low pressure systems over sea.
Low pressure systems over land.
High pressure systems over land.
Which of the following will dissipate orographic fog?
Downslope wind
Upslope wind
Increased dewpoint
Anabatic wind.
Freezing fog exists if fog droplets
Are freezing very rapidly
Are supercooled
Freeze when temperature falls below zero
Are frozen
Steam fog (arctic sea smoke) occurs in air:
With warm mass properties
With cold mass properties
That is absolutely stable
That is stable
What flying conditions are normally encountered when flying in cirrus clouds?
What flying conditions are normally encountered when flying in cirrus clouds?
Average horizontal visibility more than 1000 m; light to moderate rime ice.
Average horizontal visibility less than 500 m; no icing.
Average horizontal visibility more than 1000 m; no icing.
Freezing precipitation occurs
Only in the precipitation of a cold front
In the form of freezing hail or freezing snow
Only in the precipitation of a warm front
In the form of freezing rain or freezing drizzle
Steady precipitation, in contrast to showery precipitation falls from
Convective clouds with little or no turbulence
Convective clouds with moderate turbulence
Stratiform clouds with severe turbulence
Stratiform clouds with little or no turbulence
Considering the North Atlantic region between 30°N and 65°N, the mean position of the Polar front during summer extends from:
NE Canada to Iceland
Greenland to Spain
Newfoundland to N Scotland
Florida to SW England
Thunderstorms in exceptional circumstances can occur in a warm front if:
The cold air is stable.
The cold air is unstable.
The warm air is unstable.
The warm air is stable.
(Refer to image)
What conditions are most likely to prevail in winter at an aerodrome located in square 3B?
Mainly overcast at 8000 ft, visibility less than 5 km in continuous moderate rain
6 - 8 oktas SC and ST, visibility moderate to poor in drizzle
Intermittent thunderstorms otherwise generally clear skies with good visibility
Broken CU base 2000 ft, visibility more than 5 km, occasional showers of rain or snow
How are the air masses distributed in a cold occlusion?
The coldest air behind and the warm air in front of the occlusion; the less cold air mass is above ground level.
The coldest air in front of and the less cold air is behind the occlusion; the warm air mass is above ground level.
The coldest air in front of and the warm air behind the occlusion; the less cold air is above ground level.
The coldest air mass behind and the less cold air in front of the occlusion; the warm air mass is above ground level.
A non-occluded frontal wave passes the airport. What form of precipitation do you expect?
Continuous rain or snow during several hours until the warm front arrives. The precipitation stops for several hours or becomes intermittent light within the warm sector. On the arrival of the cold front, showers will occur.
Showers during a few hours until the warm front arrives. Drizzle in the warm sector. Continuous rain or snow on the passage of the cold front.
Rain or snow for about 12 hours until the warm front arrives. Within the warm sector rainfall increases. On the arrival of the cold front precipitation ceases.
Continuous rain or snow while the frontal wave passes for a period of some 24 hours.
In which main direction does a Polar front depression move?
Along the front towards the west
Along the front towards the east
Across the front towards the south
Across the front towards the north
What characterizes a stationary front?
The surface wind has its direction parallel to the front
The surface wind has its direction perpendicular to the front
The warm air moves at approximately half the speed of the cold air
The weather conditions that it generates are a combination of those of an intense cold front and those of a very active warm front
