Results
#1. Trade winds are most prominent or strongest
The trade winds are air currents closer to Earth’s surface that blow from east to west near the equator over the ocean
#2. A layer of air can be
if dry air is disturbed it will return to is original position, in other words the air is stable, however, when saturated air is disturbed it will continue to rise and it is unstable.
#3. On a significant weather chart you notice a surface weather front with an arrow labelled with the no. 5 pointing outward perpendicular from the front. This would indicate
#4. With all other things being equal with a high and a low having constantly spaced circular isobars. Where is the wind the fastest?
if air is moving steadily around a high, then the centrifugal force acts with the Pressure Gradient Force (PGF), increasing the velocity of the wind.
#5. Blocking Anticyclones prevent the polar front from arriving over the UK and originate from?
Blocking anticyclones are warm anticyclones formed from an extensions of high pressure areas developed in the sub- tropical regions, may hold up or divert the normal west-east passage of polar front depressions and persist for several days. In order for the anticyclone to block the passage of polar fronts it must be at higher latitudes than its parent sub tropical high. the blocking anticyclone must persist at latitudes between 45° to 65°
#6. Foehn winds are
The Föhn Wind is a warm dry wind which blows on the downwind side of a mountain range. It is a local wind in the Alps
#7. The Gust Front is
#8. Cu is an indication of
Cumulus cloud is the most common form of convective cloud, being classified as heaped cloud, from Latin cumulare meaning to heap up. For glider pilots, a developing cumulus is regarded as a reliable indication of the presence of thermal upcurrents
developed cumulus cloud is generally dense, with sharp outlines. As it continues to develop vertically, a cumulus cloud forms mounds, domes or towers, of which the upper parts often resemble the head of a cauliflower
#9. Which clouds are evidence of stable air?
Stratus (from Latin stratum, meaning strewn) is generally a grey, layered cloud with a fairly uniform base, which may produce drizzle, or light snow. Stratus cloud is no more than 1,000 – 1 500 ft thick, and is often much thinner
#10. Lack of cloud at low level in a stationary high is due to:
Clouds form with rising air, not sinking air, high pressure has air sinking in the centre
#11. What is the ratio of height to width in a typical Jet stream:
The length, width and height of a typical mid-latitude jet stream is 1000 nautical miles, 150 nautical miles and 18000 feet respectively. Depth width ratio of about 1:100
#12. When and where does an Easterly Jet stream occur:
TEJ tropical easterly jet stream
The easterly jet is a jet stream that occurs only in the summer of the northern hemisphere at approx. 45000 ft, from south east Asia extending over southern India to central Africa.
only one which travels to west
#13. What degree of turbulence, if any, is likely to be encountered while flying through a cold front in the summer over central Europe at FL100?
cb will be found at 10000 feet which will have severe turbulence
#14. An easterly wave is a:
#15. What is the most common freezing precipitation?
Freezing rain occurs when the layer of freezing air is so thin that the raindrops do not have enough time to freeze before reaching the ground. Hence precipitation is rain or drizzle,
#16. Which of the following is an example of a Foehn wind?
Although Föhn winds blow in the Alps, the name is used generically to describe winds which blow with similar effect in other parts of the world. One such wind is the Chinook which blows on the Eastern side of the Rocky mountains of North America.
#17. From which of the following clouds are you least likely to get precipitation in summer?
Cs are high level clouds and AS are medium level and are very less likely to produce rain , indicates approaching weather system
#18. What is a cold pool?
COLD AIR POOLS
These are outbreaks of cold air from near the poles. These outbreaks are usually characterized by a cold front at their leading edge. In fact they are common just behind the polar front depressions
Although surface temperature anomalies such as cold pools are not evident on surface pressure charts, they can be found most notably by looking at pressure charts in the middle to upper atmosphere. You may remember that cold air causes pressure to fall more rapidly with height, reducing the pressure in the upper atmosphere. Therefore by analyzing a pressure chart in the middle to upper atmosphere you can identify cold air pools by the low pressure they create
#19. Where do you find information on ICING and CAT?
ignificant Weather (SIGWX) charts provide invaluable meteorological information to aircraft operators and flight crew. Particularly for longer flights, or when weather issues may be a factor, SIGWX charts can be a vital flight planning tool.
the only cloud shown in waf sigwx chart is CB moderate and severe icing is associated to a cb, INFO ON CLEAR AIR TURBULENCE IS ALSO PROVIDED
#21. Relative humidity:
Relative Humidity is a term used to describe the quantity of water vapour that exists in a gaseous mixture of air and water.
water vapour increases rh changes
#22. What happens to the temperature of a saturated air mass when forced to descend?
Saturated air that is either forced to rise or descend within the atmosphere will change its temperature, on average by 0.6°C per 100 m (1.8°C/1000 ft).
The SALR varies strongly with the moisture content, which when saturated, depends on temperature, and pressure of the air parcel.
dalr temp will increase 1°C per 100 m , it will heat up more than salr
#23. A warm front occlusion is approaching the east coast of the UK. What WX would you expect in the North Sea during summer?
this is how an occluded front looks(cold or warm)
#24. What is the average height of the Tropopause at the equator?
The warmer the air, the higher the tropopause. The colder the air, the lower the tropopause. Generally over the poles, the tropopause can be between 8 -10 km and over the equator 16 – 18 km.
#25. The Tropopause is lower:
The warmer the air, the higher the tropopause. The colder the air, the lower the tropopause. Generally over the poles, the tropopause can be between 8 -10 km and over the equator 16 – 18 km.
#26. An airfield has an elevation of 540ft with a QNH of 993mb. An aircraft descends and lands at the airfield with 1013mb set. What will its altimeter read on landing?
1013 will be below 993 in atmosphere
20 hpa difference will add 540 feet
Under normal conditions, pressure varies by 1 hPa per 27 feet.
hence add 540 to current altitude
1080 feet with 1013 set
#27. In a METAR a gust is reported when:
mean speed taken over 10 minutes , gust reported 10 knots
#28. When is pressure altitude equal to true altitude?
True Altitude = Pressure Altitude plus(ISA Deviation × 4/1000 × Indicated Altitude)
if deviation is 0 true altitude is equal to pressure altitude
which is only in international standard condition
#29. What is the relationship between QFE and QNH at an airport 50ft below MSL?
In simple words
qfe is pressure at the airfield
qnh is pressure at the sea level right below the airport
setting QFE will give the height of the aircraft from the airfield
setting QNH will give height of the aircraft from the sea level( elevation)
if the airfield is below the sea level atmosphere will exert more pressure on the air field than sea level
#30. Where would a pilot find information about the presence of a jet stream?
Significant Weather (SIGWX) charts provide valuable meteorological information to aircraft operators and flight crew. Particularly for longer flights, or when weather issues may be a factor, SIGWX charts can be a vital flight planning tool.
the only cloud shown in waf sigwx chart is CB moderate and severe icing is associated to a cb AND INFORMATION ON JET STREAM AND CLEAR AIR TURBULENCE
#31. Up to FL180 ISA Deviation is ISA +10°C. What is the actual depth of the layer between FL60 and FL120?
FL120 minus FL060 is 6000 feet in ISA. The question relies upon you knowing the altimeter correction for temperature deviations from ISA. The accepted appoximation is 4% height difference for every 10°C below standard temperature as measured at the altimeter setting source. This is safe for all altimeter setting source altitudes for temperatures above -15°C.
6000 feet x0.04 x 10/10 = 240 feet
.The 0.04 is the 4%, the 10 is the ABOVE ISA deviation.
The altimeter will still register the difference as 6000 feet but in reality we have an approximate depth of 6240 feet
Warmer than ISA — altimeter under-reads.
Colder than ISA — altimeter over-reads.
#33. What is the effect of a mountain valley wind?
A wind blowing against a mountain is impeded. If the barrier is broken by a gap or valley, the wind will blow along the valley at an increased speed due to the restriction.
#34. What is the name of the dry, dusty wind blowing in North West Africa from the North East?
The Harmattan is a cool dusty wind that may reduce visibility to below 1000m, especially in areas bordering desert regions, such as Kano, Nigeria. The dust layer may extend to 7,000 or 10,000 ft or more, visibility improves towards the coast. The Harmattan blows from November through to April, though by this time the winds will be light, especially in the south.
#35. What is the difference between Gradient and Geostrophic winds?
The gradient wind occurs when the isobars are curved.
The Geostrophic Wind blows parallel to straight isobars.
#36. In still air a lapse rate of 1.2°C/100m refers to:
Elr is not a fixed value
where as
Saturated air lapse rate is0.6°C per 100 m (1.8°C/1000 ft).
unsaturated or dry air has lapse rate 1°C per 100 m (3°C/1000 ft)
#37. What happens to the temperature of a saturated air mass when descending
Saturated air that is either forced to rise or descend within the atmosphere will change its temperature, on average by 0.6°C per 100 m (1.8°C/1000 ft).
The SALR varies strongly with the moisture content, which when saturated, depends on temperature, and pressure of the air parcel.
dalr temp will increase 1°C per 100 m , it will heat up more than salr
#38. What prevents air from flowing directly from a high to a low pressure
Coriolis Force, (CF), is the force caused by the rotation of the earth.
It acts 90° to the wind direction causing air to turn to the right in the northern hemi-sphere and to the left in the Southern hemisphere. CF is maximum at the poles and minimum at the equator.
#40. Flying from A to B at a constant indicated altitude in the northern hemisphere.
when you fly from high to low altimeter overreads
also in a low Pressure area indicated altitude is more than true altitude hence true altitude is lower as indicated altitude is same.
#41. What is the relationship between the 5000 ft wind and the surface wind in the southern hemisphere
Due to friction the surface wind is slower than the geostrophic (freestream) wind.
In NH the surface wind Backs.
In SH the surface wind Veers
#42. What is the relationship between the 2000 ft wind and the surface wind in the Northern Hemisphere
Since surface friction has reduced the wind velocity, resulting in a reduction in the Coriolis Force, the PGF is now more dominating. This causes the wind to blow across the isobars towards the low
#43. The DALR is
Elr is not a fixed value
where as
Saturated air lapse rate is0.6°C per 100 m (1.8°C/1000 ft).
unsaturated or dry air has lapse rate 1°C per 100 m (3°C/1000 ft)