NAME (dispersion model)
Encyclopedia
The NAME atmospheric pollution dispersion model
was first developed by the UK's Met Office
in 1986 after the nuclear accident at Chernobyl
, which demonstrated the need for a method that could predict the spread and deposition of radioactive gases or material released into the atmosphere
.
The acronym, NAME, originally stood for the Nuclear Accident ModEl. The Met Office has revised and upgraded the model over the years and it is now used as a general purpose dispersion model. The current version is known as the NAME III (Numerical Atmospheric dispersion Modeling Environment) model. NAME III is currently operational and it will probably completely replace the original NAME model sometimes in 2006.
air pollution dispersion model
for short range to global range scales. It employs 3-dimensional meteorological data provided by the Met Office's Unified National Weather Prediction Model. Random walk
techniques using empirical
turbulence
profiles are utilized to represent turbulent mixing. In essence, NAME follows the 3-dimensional trajectories of parcels of the pollution plume
and computes pollutant concentrations by Monte Carlo method
s — that is, by direct simulation rather than solving equations.
NAME uses a puff
technique when modelling dispersion over a short range which shortens the time needed to compute the pollutant concentrations at the receptors.
The model has the capability to calculate: the rise of buoyant plumes
; deposition of pollution plume components due to rainfall (ie., wet deposition
); dry deposition
; plume chemistry focusing on sulphate and nitrate chemistry; plume depletion via the decay of radioactive materials; the downwash effects
of buildings.
The model can also be run 'backwards' to generate maps that locate possible plume originating sources.
Over the years, NAME has been applied to radioactive releases, the Kuwaiti oil fires
, major industrial fires and chemical spills, and two volcanic eruptions in Iceland.
www.crcpress.com www.air-dispersion.com
Atmospheric dispersion modeling
Atmospheric dispersion modeling is the mathematical simulation of how air pollutants disperse in the ambient atmosphere. It is performed with computer programs that solve the mathematical equations and algorithms which simulate the pollutant dispersion...
was first developed by the UK's Met Office
Met Office
The Met Office , is the United Kingdom's national weather service, and a trading fund of the Department for Business, Innovation and Skills...
in 1986 after the nuclear accident at Chernobyl
Chernobyl
Chernobyl or Chornobyl is an abandoned city in northern Ukraine, in Kiev Oblast, near the border with Belarus. The city had been the administrative centre of the Chernobyl Raion since 1932....
, which demonstrated the need for a method that could predict the spread and deposition of radioactive gases or material released into the atmosphere
Atmosphere
An atmosphere is a layer of gases that may surround a material body of sufficient mass, and that is held in place by the gravity of the body. An atmosphere may be retained for a longer duration, if the gravity is high and the atmosphere's temperature is low...
.
The acronym, NAME, originally stood for the Nuclear Accident ModEl. The Met Office has revised and upgraded the model over the years and it is now used as a general purpose dispersion model. The current version is known as the NAME III (Numerical Atmospheric dispersion Modeling Environment) model. NAME III is currently operational and it will probably completely replace the original NAME model sometimes in 2006.
Features and capabilities of NAME
NAME (in its current NAME III version) is a LagrangianAir pollution dispersion terminology
Air pollution dispersion terminology includes the words and technical terms that have a special meaning to those who work in the field of air pollution dispersion modeling...
air pollution dispersion model
Atmospheric dispersion modeling
Atmospheric dispersion modeling is the mathematical simulation of how air pollutants disperse in the ambient atmosphere. It is performed with computer programs that solve the mathematical equations and algorithms which simulate the pollutant dispersion...
for short range to global range scales. It employs 3-dimensional meteorological data provided by the Met Office's Unified National Weather Prediction Model. Random walk
Random walk
A random walk, sometimes denoted RW, is a mathematical formalisation of a trajectory that consists of taking successive random steps. For example, the path traced by a molecule as it travels in a liquid or a gas, the search path of a foraging animal, the price of a fluctuating stock and the...
techniques using empirical
Empirical
The word empirical denotes information gained by means of observation or experimentation. Empirical data are data produced by an experiment or observation....
turbulence
Turbulence
In fluid dynamics, turbulence or turbulent flow is a flow regime characterized by chaotic and stochastic property changes. This includes low momentum diffusion, high momentum convection, and rapid variation of pressure and velocity in space and time...
profiles are utilized to represent turbulent mixing. In essence, NAME follows the 3-dimensional trajectories of parcels of the pollution plume
Air pollution dispersion terminology
Air pollution dispersion terminology includes the words and technical terms that have a special meaning to those who work in the field of air pollution dispersion modeling...
and computes pollutant concentrations by Monte Carlo method
Monte Carlo method
Monte Carlo methods are a class of computational algorithms that rely on repeated random sampling to compute their results. Monte Carlo methods are often used in computer simulations of physical and mathematical systems...
s — that is, by direct simulation rather than solving equations.
NAME uses a puff
Air pollution dispersion terminology
Air pollution dispersion terminology includes the words and technical terms that have a special meaning to those who work in the field of air pollution dispersion modeling...
technique when modelling dispersion over a short range which shortens the time needed to compute the pollutant concentrations at the receptors.
The model has the capability to calculate: the rise of buoyant plumes
Air pollution dispersion terminology
Air pollution dispersion terminology includes the words and technical terms that have a special meaning to those who work in the field of air pollution dispersion modeling...
; deposition of pollution plume components due to rainfall (ie., wet deposition
Air pollution dispersion terminology
Air pollution dispersion terminology includes the words and technical terms that have a special meaning to those who work in the field of air pollution dispersion modeling...
); dry deposition
Air pollution dispersion terminology
Air pollution dispersion terminology includes the words and technical terms that have a special meaning to those who work in the field of air pollution dispersion modeling...
; plume chemistry focusing on sulphate and nitrate chemistry; plume depletion via the decay of radioactive materials; the downwash effects
Air pollution dispersion terminology
Air pollution dispersion terminology includes the words and technical terms that have a special meaning to those who work in the field of air pollution dispersion modeling...
of buildings.
The model can also be run 'backwards' to generate maps that locate possible plume originating sources.
The Met Office's commitments to emergency response service
The Met Office has international commitments to provide emergency response dispersion modelling services for releases of hazardous gases and materials into the atmosphere. Such events include the release of radioactive materials and emissions from erupting volcanoes. Those commitments are met by an operational group known as EMARC who are supported by a Met Office team of dispersion modelling staff. That team is also responsible for the scientific development of NAME III which, combined with the Met Office numerical weather prediction model, is used to provide the dispersion modelling services needed to implement the listed commitments:- The WMO (World Meteorological Office) has designated the Met Office to operate one of the worldwide RSMCs (Regional Specialist Meteorological Centre), which the Met Office located at BracknellBracknellBracknell is a town and civil parish in the Borough of Bracknell Forest in Berkshire, England. It lies to the south-east of Reading, southwest of Windsor and west of central London...
. - The Met Office has also been designated a VAACVolcanic Ash Advisory CenterA Volcanic Ash Advisory Center is a group of experts responsible for coordinating and disseminating information on atmospheric volcanic ash clouds that may endanger aviation. As of 2010, there are nine Volcanic Ash Advisory Centers located around the world, each one focusing on a particular...
(Volcanic Ash Advisory Centre) which is part of the IAVW (International Airways Volcano Watch) set up by the ICAO (International Civil Aviation Organization).
Over the years, NAME has been applied to radioactive releases, the Kuwaiti oil fires
Kuwaiti oil fires
The Kuwaiti oil fires were caused by Iraqi military forces setting fire to 700 oil wells as part of a scorched earth policy while retreating from Kuwait in 1991 after invading the country but being driven out by Coalition military forces...
, major industrial fires and chemical spills, and two volcanic eruptions in Iceland.
See also
- Bibliography of atmospheric dispersion modeling
- Atmospheric dispersion modelingAtmospheric dispersion modelingAtmospheric dispersion modeling is the mathematical simulation of how air pollutants disperse in the ambient atmosphere. It is performed with computer programs that solve the mathematical equations and algorithms which simulate the pollutant dispersion...
- List of atmospheric dispersion models
- UK Dispersion Modelling BureauUK Dispersion Modelling BureauThe UK Dispersion Modelling Bureau is part of the Met Office which is the UK's national weather and meteorological service...
Further reading
For those who are unfamiliar with air pollution dispersion modelling and would like to learn more about the subject, it is suggested that either one of the following books be read:www.crcpress.com www.air-dispersion.com
External links
- Met Office web site (page devoted to the NAME model)