Lesson 1 Flashcards
Runway number is is mag/true
Magnetic
ACARS stands for
Aircraft communication addressing and reporting system
Pilot reports known as
PIREP
SIGMET stands for
Significant weather report
Can be based on PIREP
OBS (in a report)
Observed
SS
sandstorm
WSPD
widespread
AIRMET
en-route weather phenomena which may affect the safety of low-level flight – Watch Office
GAMET
area forecast – low level – Met Office (Exeter).
Low-level aircraft operations - what altitude
(below FL100, or FL150 in mountainous areas)
Constant Pressure Charts are known as what and show what?
Isohypes
TS
Thunderstorm
GR
Hail
Jet stream speed
Filled in arrow:
50kn
Jet stream speed
Short single line
5kn
CAT
Clear air turbulence
Jet stream speed
Tall single line
10kn
Horizontal line with an upward arrow
moderate CAT
If the upward arrow has a hat then
severe CAT
What do you call the fastest part of the jetstream
jetstream core
Jetstream has the below label, what does it mean?
FL310
210/380
Core at FL310
Jetstreams found between FL210 and FL380
Hail can only come from a
Thunderstorm
SIGWX Chart
learn the symbols
TRS
tropical revolving storm
What weather source would you use in flight?
D-VOLMET or VOLMET
ATIS
What is weather radar looking for?
Detects location and movement of water droplets
Which technology does weather radar use?
microwave
What return the strongest on weather radar?
Wet Hail (stronest)
Rain
Wet snow
What return the weakest on weather radar?
Dry hail
Dry snow
Drizzle (lowest)
Weather radar:
what does a hook suggest
Indicates rotation
Weather radar:
what does a ‘finger’ suggest
Active cell with tail
A simple lightweight detector is known as a
Stormscope
On a weather radar, what does ‘blind alley’ mean’?
There may be something behind the trace
Satellites have two characteristics;
orbit type
type of detector.
The two main satellite detector types are;
Visible Imagery
Infrared Imagery
The two main satellite orbit types are;
Geostationary Orbiting Environmental Satellite
Polar Orbiting Environmental Satellite (POES)
Polar Orbiting Environmental Satellite (POES)
Orbit at 850km above surface
They orbit from pole to pole, perpendicular to the Equator
These monitor cloud cover and water vapour
Observe the Earth’s surface twice a day
Give bands of detailed, high resolution images
Viewable areas are “narrow” bands (900nm wide)
Visible Imagery
Reflects sunlight.
Useful for seeing cloud patterns and weather fronts.
Only during daylight hours
Better at detecting low cloud or fog (than IR)
Satellite Observations - Infra-red (IR)
Day or night
Colour (or Shading) shows cloud temps
IR is reverse negative so high/cold clouds appear white, low cloud dark.
This is better for high clouds
Satellite Imagery can be used to identify
Fronts (cloud band)
Low (cloudy) systems
High (clearer) systems
Stable (flat) air mass
Unstable (lumpy) air mass
Satellite Imagery - described by IR or visible?
Only during daylight hours
Visible
Satellite Imagery - described by IR or visible?
High clouds are Bright white
IR
Satellite Imagery - described by IR or visible?
Low clouds are not distinguishable from high clouds
Visible
Satellite Imagery - described by IR or visible?
Low clouds are Very dark (can blend in with the ground)
IR
Satellite Imagery - described by IR or visible?
High resolution
Visible
Satellite Imagery - described by IR or visible?
Thich clouds are Not distinguishable from thin clouds
IR
Temperature is
the average kinetic energy of the atoms or molecules of a substance, perceived as how hot or cold it is
How do you convert °c into °K
Add 273
Fahrenheit = Celsius
Fahrenheit = (Celsius×1.8)+32
What’s the name of the white box weather station?
Stevenson’s Screen
At what height is the white box weather station rigged?
Stevenson’s Screen situated 4ft (1.2m) above ground level (agl)
What helium filled contraption takes weather readings?
Radiosonde
What do weather balloons record during their climb?
During its climb, it continuously records data in 1.3 sec intervals
Temperatures
Pressure
Humidity
SILO
Shortwave
In
Longwave
Out
When is the hottest part of the day
1500hrs
Insolation is?
= Sun heats the earth’s surface
same amount of energy covering a greater Earth surface at higher latitude
-> less insolation
Earth tilt’s off axis at what angle
23.5°
Solstice
22nd December
21st June
Equinox
23rd September
21st March
Whats’ the name for being closest to the sun
Perihelion
What’s the name for being furthest from the sun?
Aphelion
ITCZ
Inter tropical convergence zone
The Intertropical Convergence Zone, or ITCZ, is a
band of low pressure around the Earth which generally lies near to the equator
Location of maximum heating is steered away from the equator by?
Land vs. ocean. The line will be drawn towards to the land.
Solar radiation reaching the earth surface depends on:
Absorption: Ozone layer & water vapour
Reflection: Tops of clouds & earth
Scattering: Particles in atmosphere
85% reaches the earths surface
Albedo
Surface reflectivity
What is the EARTH’s ALBEDO (AVERAGE)
EARTH’s ALBEDO (AVERAGE) 31%
Energy transfer by contact
Conduction:
Energy transfer by vertical movement of air
Convection:
Advection:
Energy transfer by horizontal movement of air
Release of latent heat
Energy transfer when condensation takes place
Energy transfer by absorption of long wave radiation
Radiation:
Turbulence
: Energy transfer by mixing of air caused by turbulence
Beneath 3000ft wing is affected by the surface. It’s called the
Friction layer
Transfer of Energy: Advection
Fog is created by moving a warm moist air from a warm region to….
a colder region so the air is cooled by the surface
Condensation process: Latent heat is released when water transitions from what to what?
Gas to solid
(get’s colder)
Condensation process: Latent heat is absorbed when water transitions from what to what?
Solid to gas
(heats up)
What is the variation of the surface temperature over a 24 hour period
Subject to the amount of energy received (gained) from the sun versus the amount of energy released (lost) from the earth
Diurnal Variations
What is an inversion?
An inversion is a layer of air in which temperature increases with height
Diurnal Variations
The curve is more gentle over the sea
What are the 2 types of inversion?
Surface (ground) inversion: Occur near to the Earth’s surface
Aloft inversion: Occur higher in the atmosphere
Ground inversion is caused by?
Cold surface, cooling the bit of air near the surface.
Cold dense air flowing down a mountain side is called a ?
Flows down any sloping terrain forming a katabatic wind.
A front is a dividing line between?
Two air masses of different temperatures.
A frontal inversion describes
a cold air mass undercuts a warm air mass and lifts it aloft, leaving warm air above and cold air below
Describe
Aloft Inversion - Subsidence Inversion
Found in subsiding (descending) air (e.g. anticyclone).
The rate at which the air descends is greater at altitude, acting like a piston.
At some height the ‘piston’ warms a thin layer creating an inversion
What is being described?
Surface temp. increases due to adiabatic warming
Upper air temp. reduce due adiabatic cooling
If the air temp. within the friction layer cools to the dew point, cloud can form
Aloft Inversion - Friction Layer Inversion
The tropopause inversion / isothermal also provides a ‘cap’ on a large scale.
Aloft Inversion – The Tropopause
One of the most dangerous hazards associated with an inversion is
WINDSHEAR
CFIT
controlled flight into terrain
Describe:
Simple Aneroid Barometer
A Barograph is used to plot pressure readings against time to give usable data for forecasting
On a surface pressure chart
A ridge is associated with what pressure system?
HIgh
On a surface pressure chart
A trough is associated with what pressure system?
Low
On a surface pressure chart
A ‘cyclonic col’ sits between systems and can provide you with what type of wind?
Light and variable
In the summer, Col is dominated by
the characteristics of the particular air mass but is often thundery in summer and dull or foggy in winter
How can you describe a col (3)
A col markedly elongated along the high-pressure axis is an ‘anticyclonic col‘
A col markedly elongated along the low-pressure axis is a ‘cyclonic col‘
where there is no marked elongation, the col is ‘neutral’
Rate of atmosphetic change is faster …
near the surface
