Meteorology Flashcards
List four types of turbulence
- Convection turb,
- Orographic turb,
- Jetstreams/CAT,
- Wake turb.
What is an ISOTHERM?
A line joining places of equal temperature.
What causes clouds to stop rising?
When the surrounding air is warmer than/same temp as the cloud air.
Describe: IAS CAS/RAS EAS TAS GS
IAS - measure of dynamic pressure.
RAS/CAS - corrected for instrument and pressure errors (IAS with a perfect gauge).
EAS - corrected for compressibility.
TAS - actual speed of aircraft through air mass. Corrected for density.
GS - TAS ± wind component for speed across ground.
How does a thunderstorm form?
- High moisture content,
- Trigger lifting
- convection
- turbulence
- frontal
- orographic - Adiabatic cooling of the rising air
- Unstable atmosphere - once air starts to rise it continues - ELR must be greater than SLR for over 10000’.
Speed of sound at ISA sea level?
661kts.
As an aircraft moves from warm air to cold air, the altimeter will over or under read?
Over read - i.e. the aircraft will be lower than the displayed altitude.
How many feet of density altitude variation is there from pressure altitude per degree of temperature?
+120’ of altitude for every 1°c increase in temperature.
What is veering and backing with respect to wind?
Veering is wind increasing on the compass, Backing is decreasing.
At what speeds do cold and warm fronts move with respect to the geostrophic wind?
Warm fronts move slower at about 2/3 for the geostrophic wind due to the stable colder air being harder to move. A cold front moves at the same rate as the geostrophic wind.
What hazards are associated with CB’s?
- Torrential rain
- Hail
- Severe turb (3000fpm downdrafts / 6000fpm updrafts)
- Severe icing
- Wind-shear and microbursts
- Lightning
Calculate Mach Number
MN=TAS/LSS
What are the two cases where wind is reported in magnetic?
ATIS, upper winds.
What temps is lightning likely?
+10° - -10°
What are the different types of fog?
- Radiation fog
- Cloudless night
- Moist air
- Winds 2-8 knots - Advection fog
- warm moist air flows across colder surface
- light winds
- e.g. valley fog
- can be reversed - sea fog is cold air over warm water. - Frontal fog
- formed in the cold air ahead of a warm occluded front.