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AVIATION
METEOROLOGY
• Meteorology is the science that study the atmosphere and
atmospheric phenomena.
“Meteo” means “something in the sky” in Greek and “Logo”
means “to describe, to express, to say”.
• Weather is the state of the atmosphere (parameters of
atmosphere) at a specific period of time and with respect to
its effect on life and human activities. It is the short term
variations of the atmosphere, as opposed to the long term,
or climatic, changes. It is often referred to in terms of
brightness, cloudiness, humidity, precipitation, temperature,
visibility, and wind
• Atmosphere is the gaseous or air portion of the physical
environment that encircles a planet.
• Aviation Meteorology (AM) is the branch of science that
study influence of meteorological variables and atmospheric
phenomena on aeronautical engineering operation. AM
develops methods and forms of meteorological service of
The main periods of Aviation Meteorology
Development
Period
1st
period
Term
1910 –
1940
Period characteristics
Use of near earth observation data, surface
weather chart, indirect methods of meteorology,
sounding balloon data about fair weather wind
1910 – First weather station was organized in
Sevastopol on the base of military pilot school.
1921 – Main weather station was founded
1922 – Aeronavigation office was founded at
Moscow airdrome to provide meteorological
service of pilots. Method of radiosensing of
atmosphere was developed under the direction
of Molchanov. This method is the basis of baric
topography chart composition that is the tool of
weather analysis.
The main periods of Aviation Meteorology
Development
Period characteristics
2nd
1940period 1960
Pressure topography charts, weather reconnaissance
data, centralized information data of weatherforecasting service, scientific study of weather hazards
at different cruising altitude are widely used.
3rd
1960period till our
days
Further equipment of weather services operation; wide
application and development of Weather radar,
weather artificial satellites and electronic calculators for
processing and indicating weather data. Computerbased systems of meteorological service of flights are
made.
ATMOSPHERE
STRUCTURE AND COMPOSITION
Composition of the Atmosphere
Gas Name
Chemical
Formula
Percent Volume
Nitrogen
N2
78.08%
Oxygen
Water *
Argon
Carbon Dioxide *
Neon
Helium
Methane *
Hydrogen
Nitrous Oxide *
Ozone *
O2
H2O
Ar
CO2
Ne
He
CH4
H2
N2O
O3
20.95%
0 to 4%
0.93%
0.0360%
0.0018%
0.0005%
0.00017%
0.00005%
0.00003%
0.000004%
Structure of the Atmosphere
• According to the influence on aircraft flight operation
Atmosphere is divided into
- specific atmosphere (up to 150 km)
- near-earth space.
• According electrical properties Atmosphere is divided into
- ionosphere
- neutrosphere
• According to the Atmosphere chemical state it can be
- Homoshere (about 80-100 km height) – chemical composition is
almost constant
- Heterosphere
Thermal
Structure
of the
Atmosphere
Troposphere (temperature
decreases with height),
Stratosphere (temperature
increases with height, the presence of
Ozone layer ),
Mesosphere (temperature decreases with height)
Thermosphere
(temperature increases with
height,
high kinetic temperature)
Exosphere
International Standard Atmosphere (ISA)
ISA has been defined by the ICAO as a mathematical
model that involves all parameters affecting the flight of an
aircraft, its performance and general behavior under
special conditions.
Standard Atmosphere is a hypothetical vertical distribution
of temperature, pressure and density that are taken to be
representative of the atmosphere for the next purposes:
Purposes of Standard Atmosphere
1) Manufacturing, graduiating and calibrating
pressure or speed related instruments like
altimeters, mach meters, pitot tube etc.
2) To design and test aircraft
Elements of the ICAO Standard Atmosphere
At Mean Sea Level (MSL)
Air temperature
Atmospheric pressure
Air density
Molar mass of air
Gravitational acceleration
Relative humidity
Vertical temperature lapse rate
15 C or 288,15 K
760 mm of mercury or 101 325 Pa
1,225 kg/m3
28,964 kg/kmol
9,8066 m/s2
0
0,65 C/100m
Above MSL
The temperature in the stratosphere is assumed to be constant (with
height)
Lapse rate From MSL to 36 00 feet
2 C/1000 feet
36 000 feet upwards
0 C/1000 feet