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V. Matthias et al.
information on the chemical reactions, the meteorological situation and on the emissions of gases and particles into the atmosphere. Many studies have emphasized the
importance of when and where substances are released into the atmosphere for the
reliability of air quality predictions, for example [4, 5, 8].
Anthropogenic emission data is typically provided in emission inventories. They
contain annual national totals for a number of emission sectors. Sometimes, the data
is given on predefined grids, however, a temporal emission distribution is usually
not given. Here, we present methods that are currently used to produce temporally
and spatially resolved emission data for certain emission sectors. Most of them
are top-down approaches that use surrogates like population density to spatially
distribute emission data. Bottom-up methods require much more information about
the properties of the emission source but they have a larger potential to produce
detailed and realistic emission data.
30.2 Emission Inventories
Emission inventories contain data from many emission sources which are combined
into aggregated emissions for a certain time span and region and for a number of
reactive substances. Typically, they are given as annual sums for a specified country.
A number of global and regional inventories with free data access exist. More information about their availability for chemistry transport model applications is given in
a review paper by Matthias et al. [11].
Emissions are classified into sectors. In these sectors emissions from any type
of units used for the same purpose and with similar properties are combined and
their emissions are added up. Examples are, among many others, heating systems in
households, power plants, small industrial facilities in a certain production sector or
cars and trucks. Specific nomenclature systems exist for these emission sectors. They
might be very broad like in the SNAP (Selected Nomenclature for Air Pollutants)
system that contains 11 sectors or much more detailed like the European NACE system (Statistical Classification of Economic Activities in the European Community),
the Nomenclature for reporting (NFR) system used in the United Nations Framework Convention on Climate Change (UNFCCC) or the NEI (National Emission
Inventory) standards used in North America. They might contain several hundreds
of sub-sectors and sub-sub-sectors. On the other hand in many regions of the world
information about emissions to air are still very sparse.
The chemical components (or “species”) included in emission inventories mainly
consist of SO 2 , NO x , CO, NMVOC, NH 3 and PM. Some species are in fact mixtures
of substances and need to be split into individual molecules (e.g. for NO x = NO +
NO 2 ) or groups of molecules (e.g. for NMVOCs) before they can be used in CTMs.
For NMVOCs, it depends on the chemical mechanism implemented in the chemistry
transport model, how a split needs to be done. For PM, sometimes components
are defined like Black Carbon (BC) and Organic Carbon (OC), which are reported
separately and treated individually in CTMs.
V. Matthias et al.
information on the chemical reactions, the meteorological situation and on the emissions of gases and particles into the atmosphere. Many studies have emphasized the
importance of when and where substances are released into the atmosphere for the
reliability of air quality predictions, for example [4, 5, 8].
Anthropogenic emission data is typically provided in emission inventories. They
contain annual national totals for a number of emission sectors. Sometimes, the data
is given on predefined grids, however, a temporal emission distribution is usually
not given. Here, we present methods that are currently used to produce temporally
and spatially resolved emission data for certain emission sectors. Most of them
are top-down approaches that use surrogates like population density to spatially
distribute emission data. Bottom-up methods require much more information about
the properties of the emission source but they have a larger potential to produce
detailed and realistic emission data.
30.2 Emission Inventories
Emission inventories contain data from many emission sources which are combined
into aggregated emissions for a certain time span and region and for a number of
reactive substances. Typically, they are given as annual sums for a specified country.
A number of global and regional inventories with free data access exist. More information about their availability for chemistry transport model applications is given in
a review paper by Matthias et al. [11].
Emissions are classified into sectors. In these sectors emissions from any type
of units used for the same purpose and with similar properties are combined and
their emissions are added up. Examples are, among many others, heating systems in
households, power plants, small industrial facilities in a certain production sector or
cars and trucks. Specific nomenclature systems exist for these emission sectors. They
might be very broad like in the SNAP (Selected Nomenclature for Air Pollutants)
system that contains 11 sectors or much more detailed like the European NACE system (Statistical Classification of Economic Activities in the European Community),
the Nomenclature for reporting (NFR) system used in the United Nations Framework Convention on Climate Change (UNFCCC) or the NEI (National Emission
Inventory) standards used in North America. They might contain several hundreds
of sub-sectors and sub-sub-sectors. On the other hand in many regions of the world
information about emissions to air are still very sparse.
The chemical components (or “species”) included in emission inventories mainly
consist of SO 2 , NO x , CO, NMVOC, NH 3 and PM. Some species are in fact mixtures
of substances and need to be split into individual molecules (e.g. for NO x = NO +
NO 2 ) or groups of molecules (e.g. for NMVOCs) before they can be used in CTMs.
For NMVOCs, it depends on the chemical mechanism implemented in the chemistry
transport model, how a split needs to be done. For PM, sometimes components
are defined like Black Carbon (BC) and Organic Carbon (OC), which are reported
separately and treated individually in CTMs.