SAFE AIR is an advanced atmospheric 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 calculating concentrations of atmospheric pollutants

Air pollution

Air pollution is the introduction of chemicals, particulate matter, or biological materials that cause harm or discomfort to humans or other living organisms, or cause damage to the natural environment or built environment, into the atmosphere....

 emitted both continuously

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...

 or intermittently

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...

 from point, line, volume and area sources

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...

. It adopts an integrated Gaussian puff modeling system

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...

.
SAFE AIR consists of three main parts: the meteorological pre-processor WINDS (Wind-field Interpolation by Non Divergent Schemes) to calculate wind fields, the meteorological pre-processor ABLE (Acquisition of Boundary Layer parameters) to calculate atmospheric parameters and a lagrangian multisource model named P6 (Program Plotting Paths of Pollutant Puffs and Plumes) to calculate pollutant dispersion.
SAFE AIR is included in the online Model Documentation System (MDS) of the European Environment Agency

European Environment Agency

European Environment Agency is an agency of the European Union. Its task is to provide sound, independent information on the environment. It is a major information source for those involved in developing, adopting, implementing and evaluating environmental policy, and also the general public...

 (EEA) and of the .Italian Agency for the Protection of the Environment (APAT).

History

SAFE AIR is developed, maintained, and distributed by the Department of Physics (DIFI) of the University of Genoa

University of Genoa

The University of Genoa is one of the largest universities in Italy.Located in Liguria on the Italian Riviera, the university was founded in 1471. It currently has about 40,000 students, 1,800 teaching and research staff and about 1,580 administrative staff.- Campus :The University of Genoa is...

, Italy. The first version of SAFE AIR was released in 1996. The current version II was released in 2003 and runs both in the Microsoft Windows

Microsoft Windows

Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...

 and Unix

Unix

Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...

 environment. It has a Fortran

Fortran

Fortran is a general-purpose, procedural, imperative programming language that is especially suited to numeric computation and scientific computing...

 codebase.

Topographic data

• Orography
  Orography
  Orography is the study of the formation and relief of mountains, and can more broadly include hills, and any part of a region's elevated terrain...
  
  
• Roughness
• Displacement level
• Land sea mask

Meteorological data

• Ambient temperature
• Wind direction
  Wind direction
  Wind direction is reported by the direction from which it originates. For example, a northerly wind blows from the north to the south. Wind direction is usually reported in cardinal directions or in azimuth degrees...
  
  
• Wind speed
  Wind speed
  Wind speed, or wind velocity, is a fundamental atmospheric rate.Wind speed affects weather forecasting, aircraft and maritime operations, construction projects, growth and metabolism rate of many plant species, and countless other implications....
  
  
• Atmospheric stability classes
  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...
  
   (A through G)
• Atmospheric pressure
  Atmospheric pressure
  Atmospheric pressure is the force per unit area exerted into a surface by the weight of air above that surface in the atmosphere of Earth . In most circumstances atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above the measurement point...
  
  
• Cloud cover
  Cloud cover
  Cloud cover refers to the fraction of the sky obscured by clouds when observed from a particular location...
  
  
• Albedo
  Albedo
  Albedo , or reflection coefficient, is the diffuse reflectivity or reflecting power of a surface. It is defined as the ratio of reflected radiation from the surface to incident radiation upon it...
  
  

Source data

• Position
• Dimension
• Release height of the emission source
• Emission discharge rate of primary and secondary pollutants
  Air pollution
  Air pollution is the introduction of chemicals, particulate matter, or biological materials that cause harm or discomfort to humans or other living organisms, or cause damage to the natural environment or built environment, into the atmosphere....
  
  
• Volume flow rate of total gas emission
• Exit gas temperature
• Exit gas speed

Features and capabilities of SAFE AIR

The model includes algorithm

Algorithm

In mathematics and computer science, an algorithm is an effective method expressed as a finite list of well-defined instructions for calculating a function. Algorithms are used for calculation, data processing, and automated reasoning...

s which take into account: downwash

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...

 effects of nearby buildings within the path of the dispersing pollution plume; effects of complex terrain; effects of coastline locations; 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...

, gravitational settling and 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...

; first order chemical reactions; pollution plume rise as a function of distance; averaging time ranging from very short to annual. The system also includes a meteorological

Meteorology

Meteorology is the interdisciplinary scientific study of the atmosphere. Studies in the field stretch back millennia, though significant progress in meteorology did not occur until the 18th century. The 19th century saw breakthroughs occur after observing networks developed across several countries...

 data input preprocessor, named ABLE.
The model is capable of simulating passive or buoyant

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...

 continuous plumes as well as short duration 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...

 releases. It characterizes the atmospheric turbulence

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...

 either by the boundary layer

Boundary layer

In physics and fluid mechanics, a boundary layer is that layer of fluid in the immediate vicinity of a bounding surface where effects of viscosity of the fluid are considered in detail. In the Earth's atmosphere, the planetary boundary layer is the air layer near the ground affected by diurnal...

 depth and the Monin-Obukhov length

Monin-Obukhov Length

The is used to describe the effects of buoyancy on turbulent flows, particularly in the lower tenth of the atmospheric boundary layer. It was first defined by Alexander Obukhov in 1946,...

 or by the Pasquill class

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...

.

See also

• Atmospheric dispersion modeling
  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...
  
  
• Bibliography of atmospheric dispersion modeling
• Atmospheric Studies Group
  Atmospheric Studies Group
  The Atmospheric Studies Group is a part of TRC Solutions, a subsidiary of TRC Companies, Inc. headquartered in Lowell, Massachusetts. The ASG provides research and consulting services in the environmental and physical sciences with major emphasis on:...
  
  
• List of atmospheric dispersion models

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

• SAFE_AIR Version II Release 1.1 User’s Guide