Met Gen 7 Flashcards
Localized meteorological conditions that produce intense wind shears at arctic airports as well as at airports situated along the coasts of Canada’s mountainous regions could be due to the presence of:
A) Nocturnal jet streams.
B) High level temperature inversions.
C) Eroding anticyclonic ridges.
D) Valley, katabatic, or funnel winds.
D) Valley, katabatic, or funnel winds.
One of the signposts for the existence of a mountain wave is:
A) Widespread convective cloud development downwind of the mountain range.
B) The presence of very strong anabatic winds.
C) The formation of scud roll cloud downwind from the first wave crest.
D) The presence of altocumulus standing lenticular clouds.
D) The presence of altocumulus standing lenticular clouds.
The lowest group of stationary clouds associated with a mountain wave is:
A) Altocumulus standing lenticular.
B) Rotor cloud.
C) Wall cloud.
D) Altocumulus castellanus.
B) Rotor cloud.
Rotor clouds found during mountain wave activity are located:
A) Over the mountain tops several thousand feet above.
B) Located at ridge top heights with their bases often extending below.
C) Beneath the wave crest within the mountain wave.
D) Both (B) and (C) are correct.
D) Both (B) and (C) are correct.
Where are lenticular clouds located in a mountain wave?
A) Over the top of the mountain peaks.
B) At the wave crests.
C) Under the wave crest at ridge top heights downstream of a mountain range.
D) At the troughs of the mountain waves.
B) At the wave crests.
The most powerful rotor associated with the presence of a mountain wave is located:
A) In the proximity of the first wave crest.
B) Approximately 50NM downwind from the lee slopes.
C) Always well below the crest of the mountain ridge and usually topped at 2000 feet above the ground.
D) Just below the tropopause, downwind of the third wave crest.
A) In the proximity of the first wave crest.
The part of a mountain wave system that usually presents the most severe turbulence is located:
A) In that area where the cap clouds spill over the leeward slopes.
B) Near the wave that is farthest from the mountain range.
C) Within that layer that is bounded by the ground and the top of the rotor cloud.
D) Just above the downwind portion of each wave crest.
C) Within that layer that is bounded by the ground and the top of the rotor cloud.
Severe turbulence at very high altitudes is likely to be associated with a mountain wave system when:
A) A warm high pressure system at the 400hPa level lies just upwind of the mountain range and parallel to it.
B) The wavelength of the standing wave is less than 5NM.
C) The air mass is statically unstable and a very unstable layer lies above the mountain range.
D) There is a jet stream wind aloft that is orientated perpendicular to the axis of the mountain range.
D) There is a jet stream wind aloft that is orientated perpendicular to the axis of the mountain range.
Which of the following statements is correct with reference to a mountain wave system?
A) Altimeter readings are likely to over-read when flying through the crest of a mountain wave.
B) This system can be easily located because characteristic cloud types are always present.
C) The freezing level is at a uniform altitude downwind from the range.
D) The most severe wave is the one that is the greatest distance downwind from the mountain range.
A) Altimeter readings are likely to over-read when flying through the crest of a mountain wave.
The tropopause is defined as the boundary between the troposphere and the stratosphere. The tropopause can be identified during a climb in the upper troposphere by the occurrence of:
A) A sudden change in the direction of the thermal wind.
B) An abrupt change in the temperature lapse rate.
C) A marked increase in air density.
D) A dramatic increase in the static air temperature.
B) An abrupt change in the temperature lapse rate.
The tropopause:
A) Shows little change in height across upper fronts.
B) Is lower over the equator than over the pole.
C) Is located just above a region of very weak westerly flow.
D) Acts as a lid on the clouds and weather of the troposphere.
D) Acts as a lid on the clouds and weather of the troposphere.
There is an abrupt change in the height of the tropopause over each:
A) Region of surface pressure field change.
B) Major topographical feature such as a mountain range.
C) Latitude interval of 15 degrees.
D) Frontal surface.
D) Frontal surface.
Which of the following air masses would most likely have the highest tropopause height?
A) mT.
B) mA.
C) mP.
D) cA
A) mT.
The tropopause is:
A) Higher and colder over a warm air mass.
B) Lower and warmer over a warm air mass.
C) Higher and colder over a cold air mass.
D) Lower and colder over a cold air mass.
A) Higher and colder over a warm air mass.
With respect to the tropopause, which of the following is a true statement?
A) It is found at a constant altitude over North America.
B) It’s altitude is great over the polar region than over the equatorial region.
C) The international Standard Atmosphere assumes the height of the tropopause to be 39,060 feet ASL.
D) It’s altitude is lower over the polar region than over the equatorial region.
D) It’s altitude is lower over the polar region than over the equatorial region.
In the International Standard Atmosphere the height of the tropopause and its temperature are specified as:
A) 29,000 ft and -43 degrees C.
B) 36,089 ft and -56.5 degrees C.
C) 39,060 ft and -55.6 degrees C.
D) 45,000 ft and -75 degrees C
B) 36,089 ft and -56.5 degrees C.
What causes jet streams to form?
A) A strong pressure gradient force between a low and a high-pressure area.
B) A strong pressure gradient force that is derived from a strong temperature contrast on the earths surface.
C) The Hadley Cell of circulation in the subtropics undergoes a long and slow acceleration as coriolis deflects the air to the right in the northern hemisphere.
D) Both (B) and (C) and correct.
D) Both (B) and (C) and correct.
Along with the presence of steep horizontal pressure gradients, which of the following constitutes a major factor in the formation of jet streams?
A) Centripetal force.
B) Linear momentum.
C) Mesoscale force.
D) Coriolis.
D) Coriolis.
Select the true statement from those listed below concerning jet streams:
A) Jet streams occur on the warm side of the frontal surface with their jet cores positioned just beneath the tropopause.
B) A jet stream located in or near the tropics is generally stronger that one that is present in the mid latitudes.
C) Extensive, dense cirrus cloud, when associated with a jet stream, is located on the cold air side of the jet core.
D) The cores of jet streams can usually be found just above the warm air tropopause.
A) Jet streams occur on the warm side of the frontal surface with their jet cores positioned just beneath the tropopause.
You would expect a north-to-south jet stream when:
A) The temperatures below the jet core are colder to the north than to the south.
B) The air beneath the jet stream is colder to the east than to the west.
C) The 200hPa contours are higher to the north than to the south.
The air is considerably warmer than ISA above the jet stream core.
B) The air beneath the jet stream is colder to the east than to the west.
Why do jet streams suddenly accelerate and decelerate?
A) Centrifugal forces around sharp ridges and troughs.
B) Changing pressure gradient forces along the earths surface.
C) Neither (A) or (B) are correct.
D) Both (A) and (B) are correct.
A) Centrifugal forces around sharp ridges and troughs.
There are several jet streams that affect the weather in Canada. How are they named?
A) Three of the jet streams are named after their under-lying front, and the fourth is called the Subtropical Jet stream, which is due to the circulation within the Hadley Cell located in the subtropics.
B) All of the jet streams are named after their underlying fronts.
C) The names are in honor of famous meteorologists.
D) Two of the jet streams are named after their underlying front, and the third is called the Subtropical Jet stream derived within the Hadley Cell.
A) Three of the jet streams are named after their under-lying front, and the fourth is called the Subtropical Jet stream, which is due to the circulation within the Hadley Cell located in the subtropics.
The height of the jet stream core that is located above the polar front is:
A) Lower than the jet stream core located above the arctic front.
B) Located at roughly the same height as the one above the arctic front.
C) Higher than the subtropical jet stream core.
D) Higher than the jet stream core located above the Arctic front.
D) Higher than the jet stream core located above the Arctic front.
One of the prime areas where CAT is found is in the vicinity of jet streams. Several statements relating to CAT and jet streams appear below. Identify those which are correct:
1) Severe CAT is likely to be present when the vertical wind shear associated with a jet stream attains a value of at least 2KT/1000 ft.
2) The threshold wind speed of a jet stream for the occurrence of CAT is approximately 90 KTs.
3) Curving jet streams are more likely to have turbulent edges than straight jet streams especially those which curve around a deep pressure trough.
4) The most severe CAT associated with a very fast moving jet stream is always located on the high pressure side of the jet stream core.
5) Wind shear and the accompanying CAT adjacent to jet streams are most intense above and to the lee side of mountain ranges.
6) The confluence of two jet streams can be a producer of CAT.
A) 1, 2, 3.
B) 2, 4, 6.
C) 3, 5, 6.
D) 1, 3, 5.
C) 3, 5, 6.
The directional changes that occur as very fast, high level winds flow around upper level troughs and ridges can result in the development of CAT. Select the statement that best describes the shear and resulting turbulence that can be expected with such mesoscale feature.
A) Upper level ridges tend to curve more sharply than do upper level troughs.
B) Turbulence associated with upper level ridges usually tends to be more severe than with upper level troughs.
C) Upper level troughs and ridges usually have the same contour curvature since they are both elongations of pressure systems.
D) Turbulence associated with upper level troughs tends to be more severe than with upper level ridges.
D) Turbulence associated with upper level troughs tends to be more severe than with upper level ridges.
The vertical extent of CAT associated with a jet stream will be the greatest on the_____side of the jet stream core. From the choices listed below select the one which is correct:
A) Low pressure, warm air mass.
B) Low pressure, cold air mass.
C) High pressure, warm air mass.
D) High pressure, cold air mass.
B) Low pressure, cold air mass.
While flying across a jet stream in North America, an aircraft encounters some CAT. The pilot checks the OAT gauge and notes a temperature rise. To quickly escape from the turbulence, he/she should:
A) Climb the aircraft.
B) Descend the aircraft.
C) Alter the aircrafts track to the south.
D) Alter the aircrafts track to the north.
A) Climb the aircraft.
Which of the following is true with respect to the Polar Jet stream?
A) Its core speed will be less when there is a marked temperature contrast across the upper front.
B) This jet stream moves north in the winter and its core speeds are less than in the summer.
C) The most severe turbulence associated with this jet stream is usually encountered on the equatorial side.
D) This Jet stream moves south during the winter and generally has higher core speeds than in summer.
D) This Jet stream moves south during the winter and generally has higher core speeds than in summer.
Jet streams having speeds above_____at the core will have areas of significant turbulence near them in the sloping tropopause above the core, in the jet stream front below the core and on the cold air side (Low pressure) side of the core. Fill in the blank.
A) 50 KTs
B) 90 KTs.
C) 110 KTs.
D) 150 KTs.
C) 110 KTs.
Flying near a jet stream in a crosswind situation and encountering moderate CAT, the pilot checks the OAT and notes it is remaining constant. In this case, in order to escape from the CAT, the pilot should:
A) Maintain the current altitude.
B) Alter track so as to parallel the jet stream axis.
C) Alter track to the south.
D) Either climb or descend the aircraft.
D) Either climb or descend the aircraft.
CAT is also related to vertical wind shear, so when the shear is greater than_____kts/1000 ft, turbulence is likely. Fill in the blank.
A) 2.
B) 5.
C) 10.
D) 25.
B) 5.
