Air pollutant dispersion models

Air pollutant dispersion models play an important role in the evaluation and forecast of the impact caused by the industrial activity, road traffic, forest fires, or any other situation in which pollutant particles are emitted to the atmosphere. Taking pollutant measurements in specific locations may not be representative of the actual situation, and modeling is needed. For example, the gases emitted by a stack can affect different areas depending on the wind direction; a nearby measurement station will only take into account the situations dominated by a certain wind direction and atmosphere stability. In order to obtain a more complete and accurate picture it is necessary to use models.

Air dispersion modeling must be used to elaborate emission inventories, air permits, certifications, etc. It can be necessary to complete, for example, new plant projects (industries, thermal power stations, etc), as well as to dispose of an operational pollution forecast tool.

Meteosim provides meteorological data for the most used air pollutant dispersion models: ISCT3, AERMOD, CALPUFF. Usually it is not possible to obtain representative meteorological data for the study area, or there are not measurements for some required variables (for example the cloud coverage or the ceiling height). In such cases, the best option is to obtain the meteorological data from a numerical weather prediction model, for example MM5 (Fifth-Generation NCAR / Penn State Mesoscale Model). The data provided by Meteosim meet the format requirements of ISCT3, AERMOD or CALPUFF, so the user has not to worry about any kind of format conversion.We can also provide land use and terrain files for the interest area.

Having the coordinates and area dimensions, the facitily details and the emissions rates, Meteosim also carries out the air dispersion modeling for a certain period of time as well as sets up operational simulations in forecast mode. An example of CALPUFF simulations in forecast mode can be found here: CALPUFF forecast maps.

MM5 Model

The MM5 meteorological model has been developed by the Pennsylvania State University and the National Center for Atmospheric Research in the United States. It is a limited-area, nonhydrostatic model designed to simulate or predict mesoscale atmospheric circulation. This model is often used to provide meteorological data to air pollutant dispersion models. Meteosim carries out high resolution MM5 simulations over the required area and time period.

Setting up of meteorological towers

In case it is required, Meteosim can also deal with the setting up of meteorological towers, as well as the data downloading and processing. The data will be processed to be ingested by the air pollution dispersion models.