Meteorology Flashcards
Minus graphing
Name the 5 atmosphere layers
Troposphere
Tropopause
Stratosphere
Mesosphere
Thermosphere
What height is ISA temperature fixed after ?
36’090ft (11Km)
What is the ISA fixed temperature after 36’090 ?
-56.6 C
Rate of temperature change in the troposphere ?
-1.98 C Per 1000ft (until 36’090 is reached)
Or -0.65 C Per 100m
-2 in calculations.
What Is ISA sea level temperature ?
+15 C
Composition of the atmosphere
78% Nitrogen
21% Oxygen
1% Other gasses
What gasses make up the 1%
Argon
Carbon dioxide
Hydrogen
Ozone (O3)
Carbon monoxide
1/2 Of water vapour is found below what ?
1.5 Km
Amount of water vapour depends on what ?
Temperature (Heat)
Warm air can hold more vapour than cold air.
Cold air has lower carrying capacity.
Height of tropopause depends on ?
Temperature of the air in the troposphere near the earths surface
Heights and Temperature of polar and equatorial tropopause
Polar 8-10 Km (-40)-(-50) C
Equatorial 16-18 Km (-70)-(-90) C
Why is the stratosphere a good or bad place to fly ?
Cloud formation is rare
Above hazards of troposphere (Eg CB)
Greater engine efficiency
Turbulence is still possible
What height is temperature constant to in the stratosphere, until the Ozone layer starts ?
Approx 20 Km (65’000ft)
What does Ozone layer do ?
Absorb short wave radiation (UV)
Ozone relationship with Stratosphere
Ozone layer in 90% within.
Ozone is responsible for the temperature increase within the stratosphere.
Negatives of ozone
Extremely corrosive gas
Can impact cabin air quality at very high altitudes, possible respiratory problems.
InHg and mmHg meaning ?
Inches/Millimeters of mercury
Relationship with altitude of pressure and density ?
Pressure and density decrease with altitude.
(pressure due to less air res)
ISA Temperature Calculation (ft)
ISA Temp = 15-2 x altitude (ft) / 1000
ISA Temperature Calculation (Km)
ISA Temp = 15-6.5 x altitude (Km)
As temperature increases density … ?
Decreases
ISA deviation is ?
ISA temp compared to actual conditions.
If it’s warmer than ISA conditions, deviation is positive (+)
If it’s colder than ISA conditions, deviation is negative (-)
What is the ISA static pressure (hPa)
1013.25
1013 in calculations
ISA Density comparison from AMSL to 22’000ft and 40’000 ft
22’000 is approx 50% compared
40’000 is approx 25% compared
World Area Forecast Centre…
(WAFC)
Issue significant weather charts every 6-9 hours.
They report:
~Upper winds/temp/humidity
~Tropopause Height/Temp
~Areas of significant weather- (CB, Icing, turbulence)
Located in London and Washington.
Meteorological offices
(MO)
Issue a Terminal Area Forecast (TAF) every 3-6 hours.
(rumour/projected report)
UK office is in Exeter
Is a low level area forecast every 6 hours (GAMET)
Meterological stations
(MS)
Issue METARS every 30-60 mins
(True report)
Issue SPECIs- interim METAR due to significant change.
Issue landing forecasts valid for 2 hours.
Issue SNOWTAM, warning of snow/ icy condition valid for up to 2 hours.
Issue Aerodrome warnings
Meteorological watch office
(MWO)
Issue weather warnings
SIGMET, upper level warning that is valid for 4-6 hours.
AIRMET, low level warning below FL100/150 valid for 4 hours.
ASHTAM, volcanic activity and ash clouds valid for up to 24 hours.
7 SIGMET info issues
Thunderstorms (TS)
Tropical cyclone
Severe turbulence
Severe icing
Severe mountain waves
Heavy sand and dust storms
Volcanic ash and Radioactive cloud
SIGMET process
Pilot encounters bad conditions, Reports to air traffic, air traffic inform higher power if required and then pass the report to the MWO who then issues the SIGMET.
Reliability of TAF and METAR
TAF is said to be more of a rumour.
METAR is said to be the truth.
CAVOK conditions
Visibility is 10km+
No CB, TCU
No significant weather phenomena
No cloud below 5000ft or Minimum sector altitude (Highest altitude + 1000ft) whichever is greater.
VOLMET
Weather reports and forecasts in flight, HF in oceanic, and VHF in Europe.
Can provide TAF, SIGMET and METAR
VHF VOLMET is normally broadcast in a continuous loop.
HF VOLMET normally published schedule with five min allocated to each station.
ATIS
Wind direction is magnetic
Takeoff and landing report by ATC
weather and operational info
change is indicated with the next letter of the alphabet
What is an aerodrome warning ?
+ Examples
Warning issued for condition that could adversely affect aircraft on the ground and pedestrians.
Fog (VIS)
Sandstorm (SS)
Freezing conditions (FZ)
Foreign objects
Birds
AIRMET + GAMET
AIRMET - En-Route weather phenomena which may affect safety at low level. (less severe than a SIGMET)
GAMET - Area forecast for low level local flights.
What is a ridge ?
Gentle extension of a high pressure system
What is a trough ?
Extension of a low pressure system
What is a line trough
Shows deep surface convection currents. It brings extreme weather (CB etc) and should be avoided.
Usually in a low pressure zone but high in summer.
What is the cut off value for high and low pressure charts ?
1013, above is high, below is low pressure.
OKTA level abbreviations ?
SKC - Sky Clear
1-2 - FEW
3-4 - SCT (Scattered)
5-7 - BKN (Broken)
8 - OVC (Overcast)
Lack of visible weather in the stratosphere is due to ?
The isothermic or inversion conditions in the stratosphere create a physical barrier to further vertical Development of cloud.
Isothermal definition
Constant temperature
ISA Density
1.225 kg/m3
Airborne Radar coverage ?
70/90º either side from heading of aircraft
How is incoming radiation distributed ?
15% is absorbed or refelcted by the earths atmosphere.
85% is felt at the ground.
Name of dark area on a weather radar ?
Shadow effect (biggest limitation)
Airborne radar controls
On/Off/Standby
Gain (sensitivity- hearing)
Tilt
Mode switch
Range (40-320)
Can go 70/90º either side of nose
Geo stationary Satellite characteristics ?
Orbit type
Type of detector
Geo stationary satellite Detector types ?
Infrared
Visible
Distance From earths surface of geo stationary satellite ?
35786 Km
POES orbit distance + P&Ns ?
850 Km
Flexible orbit
Better resolution
Picks up small details
Not good at tracking storm movements
50% sea level pressure is at what height ?
18’000 ft
Half and a quarter of sea level density is at what height ?
Half is 22’000 ft
1/4 is 40’000 ft
QNH is ?
Sea level pressure (distance above sea level)
QFE is ?
Pressure at a point above ground level (height)
(On the ground it reads 0)