Meteorology Flashcards
Name the structures of the atmosphere
Trophosphere
Tropopause
Ozone layer
Stratosphere
Stratopause
Mesosphere
Mesopause
Thermosphere
What does ISA stand for?
International Standard Atmosphere
What height is ISA temperature fixed after?
36,090 ft
What is the ISA fixed temperature after 36,090ft?
-56.5 C
What is the ISA sea level temperature?
+15C
What is the temperature lapse rate?
The rate at which temperature changes with height in the Atmosphere
What is the temperature lapse rate in Troposphere?
1.98C/100ft (until 36,090ft is reached)
(2C/1000ft for calculations)
How is the lower part of the troposphere heated?
Earths surface
What is the composition of the atmosphere?
78% Nitrogen
21% Oxygen
1% Other gases
What makes up the 1% other gases in the atmosphere?
Argon
Carbon Dioxide
Hydrogen
Ozone (O3)
Carbon Monoxide - emitted by volcanos
What does carbon dioxide do in the atmosphere?
Acts as a blanket (keeps earth warm)
By reflecting long wave radiation
Water vapour makes up what % of the atmospheres volume at lower levels?
4%
1/2 of water vapours mass is found below what measurement?
1.5km
How much water vapour is contained in the troposphere?
99%
The amount of water vapour in the air depends on what?
Temperature
Warm air can hold more vapour than cold air
Cold air has a lower carrying capacity
In the Tropopause what no longer decreases with height?
Temperature
The height of the tropopause depends on what?
Temperature of the earths surface
What is the height and temperature of the Tropopause?
36,090ft and -56.5C
Up to 60,000-65,000 in warmer countries
The warmer it is the … the tropopause
The colder it is the … the tropopause
Higher
Lower
Heights and Temperature of polar and equatorial tropopause
Polar 8 (winter)-10km(summer) (-40C/-50C) - lower due to angle relative to the sun
16-18km high (-70C/-90C)
Where is the jet stream?
Just below the tropopause
Whats the relationship between the Tropopause and Latitude?
Changes in height due to the relative tilt, changes of planet (relative to the sun)
Why is the stratosphere a good or bad place to fly?
Cloud formation is rare
Above hazards of troposphere (E.g CB)
Turbulence is still possible
What height is the temperature constant to in the stratosphere, until the Ozone layer starts?
Approximately 65,000ft
What does the Ozone layer do?
Absorb short wave radiation (UV)
What’s the relationship between Ozone and the stratosphere
Ozone layer is 90% within the stratosphere
Ozone is responsible for the temperature increase within the stratosphere
Ozone negatives
Extremely corrosive gas
Can impact cabin air quality at high altitudes, possible respiratory problems - smells like chlorine
InHg and mmHG meaning?
Inches/millimetres of Mercury
Relationship with altitude of pressure and density?
Pressure and density decrease with altitude
(pressure due to less air resistance)
ISA Temperature Calculation
ISA Temp = 15-2 x altitude (ft) / 1000
What is ISA deviation?
ISA temp compared to actual conditions
If its warmer than ISA conditions, deviation is (+)
If its colder than ISA conditions, deviation is (-)
What does hPA stand for?
Hectopascal
What is the ISA static pressure? (hPA)
1013.25
(1013 in calculations)
What is the pressure change rate?
1hPA/30ft
1hPA/9m near sea level
What does AMSL mean?
Above mean sea level
ISA density comparison from AMSL to 22,000ft and 40,000ft
22,000 is approx 50% compared to AMSL
40,000 is approx 25% compared to AMSL
Pressure is … of surface value at 18,000ft
50%
As temperature increases, density…
Decreases
As altitude increases, temperature
Decreases
What does ICAO stand for?
International Civil Aviation Organisation (ICAO)
TAF
Terminal Area Forecast
(RUMOUR)
METAR
Meteorological Aerodrome Report
(TRUTH)
What is an ASHTAM
Provides info on the status activity of a volcano when there’s been/(going to be) a change in its activity
What is WAFC?
World Area Forecast Centre
Located in London/Washington
What do WAFC do?
Issue significant weather charts every 6-9h
They report
~Upper winds/temp/humidity
Tropopause height/temp
~Areas of significant weather - (CB, icing, turbulence)
What are Meteorological Offices? and what do they do?
Located all over the world (UK office = Exeter)
Issue TAF every 3-6h, valid between 6 and 30 hours
Issue low level area forecast every 6h if required
What do Meteorological stations do?
TRUE REPORT
Aerodrome based
Issue METARS every 30-60mins
Issue SPECI as required - significant change in weather
Issue TREND/LANDING forecast - valid for 2 hours
Issue SNOWTAM - snow/slush/ice warning - valid up to 8h
Issue AERODROME WARNING (ADW) - warning of conditions affecting aircraft, vehicles and facilities - everyone
What is MWO and what do they do?
Meteorological Watch Offices
Issue weather warmings:
~SIGMET, upper level - 4/6h
~AIRMET, low level below FL100/150 - 4h
~ASHTAM, volcanic activity/ash clouds - 24h (6h if active
What does VAA and TCA stand for?
Volcanic Advisory
Tropical Cyclone Advisors
What is a SIGMET?
Warning of dangerous meteorological conditions - from MWO
Include
Thunderstorms
Tropical Cyclone
Severe Turbulence
Servere Icing
Severe mountain waves
Heaving sand/dust storm
Volcanic ash/radioactive cloud (VA & RDOACT)
SIGMET timeline
Air report > ATC > MWO > WAFC’s ( di sect SIGMET)
WAFC’s >MWO > ATC > Aircraft behind
OKTA’s Sky Coverage
8th Sky
SKC - Sky Clear
FEW - 1-2
SCT - 3-4
BKN - 5-7
OVC - 8
Airbourne weather radar controls…
On/Off/Stby
Gain (sensitivity)
Tilt (up/down)
Mode Switch (Wx,Ground,Turb)
Range 40-320nm
When must your Airborne weather radar be turned off?
At/near the terminal
What does the Airborne Weather Radar do when on stby?
Warms up - ready for use
Label the weather radar and state different colours
What doesnt the Weather radar pick up?
CAT
Clear Air Turbulence
Label the different weather systems on the radar
What is the blind alley affect?
Shadowing
Black areas don’t always mean no threat
~ Radar can be blocked from weather systems so cannot see as far as it normally can
Why do you have to change the gain on the Weather radar?
For the range, so you have to increase/decrease the sensitivity
What is a ground based weather radar?
Detects location/movement of water droplets
How does the ground based weather radar work?
Sends out pulses of microwave energy
Listens for returning signals from target (droplets)
What are the two main types of detectors?
Visible Imagery
Infared Imagery
Satellite Visible imagery
Reflects sunlight
Useful for seeing cloud patterns
Only during daylight hours
Better detecting low cloud/fog than IR
Satellite Infrared imagery
Day/Night
Colour - cloud temps
High/cold clouds = white
Low clouds = dark
What are the two types of Satellite Observations?
Orbit type
Detector type
What is a Geo-Stationary Satellite?
It focuses on one particular area
How far is the Geo-Stationary Satellite away from earth?
35786km
Geo-Stationary Satellite Positives
~Good overall picture
~Tracking a system
~Monitoring of the atmosphere
Geo-Stationary Satellite Negatives
~Poor Resolution
~Not good at seeing small changes
What is the Polar Orbiting Satellite?
Orbits from pole to pole (N>S)
~ Have to wait to obersve certain area once satellite comes bak round
How often does the Polar Orbiting Satellite orbit each day?
Twice a day
Polar Orbiting Satellite Positives
~Sees small picture
~Better resolution
~Good tracking of small features
~Flexible Orbit
Polar Orbiting Satellite Negatives
~Narrow Range
~Not Good at tracking a storm movement
How far is the Polar Orbiting Satellite away from earth?
850km
What is an Atmospheric Motion Vector?
Detects motion of wind
~ Shows jet streams
What is Temperature?
Avergage kinetic energy of the atoms or molecules
Celcius Equation
Kelvin Equation
Fahrenheit Equation
What piece of equipment do you use to measure temperature and how does it work?
Old Style Thermograph
Plots temperature change with time or height
How to measure surface air temperature?
Stevenson Screen
~ Situated 1.2m off the ground to avoid ground heat interference
~ Measures surface temp and humidity
How accurate is the Stevenson Screen?
95%
How to measure Upper Air Temperature?
Radiosonde
What three sets of data does a radiosonde record?
Temperature
Pressure
Humidity
How does a Radiosonde work?
Rises to 115,000ft
Records data every 1.3s during climb (every second but takes 0.3s to get data to ground)
Transmitted by VHF radio
What is an inversion?
Temperature increase with height