WAtmospheric dispersion modeling is the mathematical simulation of how air pollutants disperse in the ambient atmosphere. It is performed with computer programs that include algorithms to solve the mathematical equations that govern the pollutant dispersion. The dispersion models are used to estimate the downwind ambient concentration of air pollutants or toxins emitted from sources such as industrial plants, vehicular traffic or accidental chemical releases. They can also be used to predict future concentrations under specific scenarios. Therefore, they are the dominant type of model used in air quality policy making. They are most useful for pollutants that are dispersed over large distances and that may react in the atmosphere. For pollutants that have a very high spatio-temporal variability and for epidemiological studies statistical land-use regression models are also used.
WThe AERMOD atmospheric dispersion modeling system is an integrated system that includes three modules:
WThe Air Quality Modeling Group (AQMG) is in the U.S. EPA's Office of Air and Radiation (OAR) and provides leadership and direction on the full range of air quality models, air pollution dispersion models and other mathematical simulation techniques used in assessing pollution control strategies and the impacts of air pollution sources.
WThe AP 42 Compilation of Air Pollutant Emission Factors is a compilation of the US Environmental Protection Agency (EPA)'s emission factor information on air pollution, first published in 1968. As of 2018, the last edition is the 5th from 2010.
WAtmospheric chemistry is a branch of atmospheric science in which the chemistry of the Earth's atmosphere and that of other planets is studied. It is a multidisciplinary approach of research and draws on environmental chemistry, physics, meteorology, computer modeling, oceanography, geology and volcanology and other disciplines. Research is increasingly connected with other areas of study such as climatology.
WThe Commonwealth Scientific and Industrial Research Organisation (CSIRO) is an Australian Government agency responsible for scientific research.
WThe Czech Hydrometeorological Institute (CHMI) is within the Environmental Ministry of the Czech Republic. The head office and centralized workplaces of the CHMI, including the data processing, telecommunication and technical services, are located at the Institute's own campus in Prague.
WDesert Research Institute (DRI) is the nonprofit research campus of the Nevada System of Higher Education (NSHE) and sister property of the University of Nevada, Reno (UNR), the organization that oversees all publicly supported higher education in the U.S. state of Nevada. At DRI, approximately 500 research faculty and support staff engage in more than $50 million in environmental research each year. DRI's environmental research programs are divided into three core divisions and two interdisciplinary centers. Established in 1988 and sponsored by AT&T, the institute's Nevada Medal awards "outstanding achievement in science and engineering".
WEnvironment Agency Wales, was, until 31 March 2013, a Welsh Government Sponsored Body, while also being part of the Environment Agency for England and Wales. Its principal aims were to protect and improve the environment in Wales and to promote sustainable development.
WThe European Environment Agency (EEA) is the agency of the European Union (EU) which provides independent information on the environment.
WThe Finnish Meteorological Institute is the government agency responsible for gathering and reporting weather data and forecasts in Finland. It is a part of the Ministry of Transport and Communications but it operates semi-autonomously.
WA flue-gas stack, also known as a smoke stack, chimney stack or simply as a stack, is a type of chimney, a vertical pipe, channel or similar structure through which combustion product gases called flue gases are exhausted to the outside air. Flue gases are produced when coal, oil, natural gas, wood or any other fuel is combusted in an industrial furnace, a power plant's steam-generating boiler, or other large combustion device. Flue gas is usually composed of carbon dioxide (CO2) and water vapor as well as nitrogen and excess oxygen remaining from the intake combustion air. It also contains a small percentage of pollutants such as particulate matter, carbon monoxide, nitrogen oxides and sulfur oxides. The flue gas stacks are often quite tall, up to 400 metres (1300 feet) or more, so as to disperse the exhaust pollutants over a greater area and thereby reduce the concentration of the pollutants to the levels required by governmental environmental policy and environmental regulation.
WFundamentals of Stack Gas Dispersion is a book devoted to the fundamentals of air pollution dispersion modeling of continuous, buoyant pollution plumes from stationary point sources. The first edition was published in 1979. The current fourth edition was published in 2005.
WThe Journal of Applied Meteorology and Climatology is a scientific journal published by the American Meteorological Society. Applied research related to the physical meteorology, cloud physics, hydrology, weather modification, satellite meteorology, boundary layer processes, air pollution meteorology, agricultural and forest meteorology, and applied meteorological numerical models of all types.
WA line source, as opposed to a point source, area source, or volume source, is a source of air, noise, water contamination or electromagnetic radiation that emanates from a linear (one-dimensional) geometry. The most prominent linear sources are roadway air pollution, aircraft air emissions, roadway noise, certain types of water pollution sources that emanate over a range of river extent rather than from a discrete point, elongated light tubes, certain dose models in medical physics and electromagnetic antennas. While point sources of pollution were studied since the late nineteenth century, linear sources did not receive much attention from scientists until the late 1960s, when environmental regulations for highways and airports began to emerge. At the same time, computers with the processing power to accommodate the data processing needs of the computer models required to tackle these one-dimensional sources became more available.
WThe Meteorological Office, abbreviated as the Met Office is the United Kingdom's national weather service. It is an executive agency and trading fund of the Department for Business, Energy and Industrial Strategy led by CEO Penelope Endersby, who took on the role as Chief Executive in December 2018, the first woman to do so. The Met Office makes meteorological predictions across all timescales from weather forecasts to climate change.
WThe National Centre of Scientific Research "Demokritos" is a research center in Greece, employing over 1,000 researchers, engineers, technicians and administrative personnel. It focuses on several fields of natural sciences and engineering and hosts laboratory facilities.
WThe National Institute for Public Health and the Environment, is a Dutch research institute that is an independent agency of the Dutch Ministry of Health, Welfare and Sport.
WThe Norwegian Institute for Air Research or NILU is one of the leading specialized scientific laboratories in Europe researching issues related to air pollution, climate change and health. It is an independent nonprofit institution, established in 1969, staffed by scientists, engineers and technicians with specialized expertise for working on air pollution problems. The staff do more than two hundred projects annually for research councils, industries, international banks and local, national and international authorities and organizations. Its director since 2009 is Kari Nygaard.
WIn hydrodynamics, a plume or a column is a vertical body of one fluid moving through another. Several effects control the motion of the fluid, including momentum (inertia), diffusion and buoyancy. Pure jets and pure plumes define flows that are driven entirely by momentum and buoyancy effects, respectively. Flows between these two limits are usually described as forced plumes or buoyant jets. "Buoyancy is defined as being positive" when, in the absence of other forces or initial motion, the entering fluid would tend to rise. Situations where the density of the plume fluid is greater than its surroundings, but the flow has sufficient initial momentum to carry it some distance vertically, are described as being negatively buoyant.
WRoadway air dispersion modeling is the study of air pollutant transport from a roadway or other linear emitter. Computer models are required to conduct this analysis, because of the complex variables involved, including vehicle emissions, vehicle speed, meteorology, and terrain geometry. Line source dispersion has been studied since at least the 1960s, when the regulatory framework in the United States began requiring quantitative analysis of the air pollution consequences of major roadway and airport projects. By the early 1970s this subset of atmospheric dispersion models were being applied to real world cases of highway planning, even including some controversial court cases.
WRoughness length is a parameter of some vertical wind profile equations that model the horizontal mean wind speed near the ground. In the log wind profile, it is equivalent to the height at which the wind speed theoretically becomes zero in the absence of wind-slowing obstacles and under neutral conditions. In reality, the wind at this height no longer follows a mathematical logarithm. It is so named because it is typically related to the height of terrain roughness elements. For instance, forests tend to have much larger roughness lengths than tundra. The roughness length does not exactly correspond to any physical length. However, it can be considered as a length-scale representation of the roughness of the surface.
WThe Royal Meteorological Society is a long-established institution that promotes academic and public engagement in weather and climate science. Fellows of the Society must possess relevant qualifications, but Associate Fellows can be lay enthusiasts. Its Quarterly Journal is one of the world's leading sources of original research in the atmospheric sciences.
WThe Royal Dutch Meteorological Institute is the Dutch national weather forecasting service, which has its headquarters in De Bilt, in the province of Utrecht, Netherlands.
WThe Swedish Meteorological and Hydrological Institute is a Government agency in Sweden and operates under the Ministry of the Environment. SMHI has expertise within the areas of meteorology, hydrology and oceanography, and has extensive service and business operations within these areas.
WThe TaiWan Ionospheric Model (TWIM) developed in 2008 is a three-dimensional numerical and phenomenological model of ionospheric electron density (Ne). The TWIM has been constructed from global distributed ionosonde foF2 and foE data and vertical Ne profiles retrieved from FormoSat3/COSMIC GPS radio occultation measurements. The TWIM consists of vertically fitted α-Chapman-type layers, with distinct F2, F1, E, and D layers, for which the layer parameters such as peak density, peak density height, and scale height are represented by surface spherical harmonics. These results are useful for providing reliable radio propagation predictions and in investigation of near-Earth space and large-scale Ne distribution with diurnal and seasonal variations, along with geographic features such as the equatorial anomaly. This way the continuity of Ne and its derivatives is also maintained for practical schemes for providing reliable radio propagation predictions.