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ADVANCED MODULES
One of the most important advanced modules in ADMS-Roads is the chemistry
module. The following chemistry options are available:
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NOx – NO2 chemistry
In ADMS-Roads there two ways to model NOx chemistry.
The first is using a simple correlation scheme
(Derwent and Middleton, 1996) but the recommended option is to
use the 8 reaction Generic Reaction Set (Venkatram
et al., 1994) that includes reactions with ozone and
hydrocarbons.
Why use this module?
The NOx chemical reactions take place over a relatively
short time period and in order to get accurate predictions of
NO2 concentrations, NOx chemistry should
be taken into account. The Generic Reaction Set predicts changes
in Ozone concentrations that are also of interest.
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Sulphate chemistry
The reactions between SO2 and other compounds in the
air to produce particulates are based on those used in the EMEP
model (Tsyro, 2001).
Why use this module?
These reactions have a significant effect on the concentrations
of particulates in areas where there are large emissions of SO2.
Other advanced modules included in ADMS-Roads are:
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Street canyons
This module is based on the Danish Operational Street Pollution
Model (OSPM, Hertel and Berkowicz, 1990, Hertel et al, 1990).
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Complex terrain
This module is based on FLOWSTAR advanced airflow model which
calculates the change in mean flow and turbulence due to terrain
and changes in surface roughness (land use).
These modules are based on the latest understanding of
the way these features affect the movement of airflow around the sources,
and all have been shown to have considerable affect on observed concentrations.
Full details of the Technical Specification of these parts of the model
can either be found on the documentation
page of this site, or on request from CERC (enquiries@cerc.co.uk).
VERIFICATION
ADMS-Urban and ADMS-Roads have been comprehensively verified
in a large number of studies. This includes comparisons with data from
the UK's Automatic Urban Network (AUN) during all of our consultancy
studies and specific verification exercises using standard field, laboratory
and numerical data sets. CERC is also involved in European programmes
on model harmonisation, and our models have been compared favourably
against other EU and US EPA systems.
For further details of verification studies that have been carried out,
please refer to the documentation page
of this site.
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