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Ozone |
  
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Ozone |
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The Pollutant ID must be set to NO2 for the Ozone folder to be enabled.
This section provides a description of the inputs related to the non-default PVMRM (Plume Volume Molar Ratio Method) and OLM (Ozone Limiting Method) options for modeling the conversion of NOx to NO2.
The PVMRM and OLM algorithms have been implemented as non-default options. A Beta-test draft model option, PSDCREDIT, has been added for use when an application is for increment consumption with PSD credits using PVMRM.
Ozone background concentrations
Background ozone concentrations can be input as a single value, or may be input as hourly values through a separate data file.
Method: One of three methods of applying background ozone concentrations can used.
| • | Single background concentration: (Model Keyword: OZONEVAL) |
| • | Background concentration file: (Model Keyword: OZONEFIL) |
| • | Background concentration file with fill value: (Model Keyword: OZONEVAL) |
Ozone file: The name of the ozone background concentration file.
Concentration: The ozone background concentration. If the "Background concentration file with fill value" option was selected, this concentration is used to fill missing data in the ozone background file. If a background ozone concentration has been specified, then that value will be used to substitute for missing ozone data from the ozone file. If no background concentration value is specified, then the model will assume full conversion for hours with missing ozone data.
Units: Select the units of the ozone background concentration data. If units of PPM or PPB are selected, the model will convert the concentrations to micrograms/cubic-meter based on the reference ambient temperature and the base elevation specified of the meteorological station.
Values of ozone concentrations in the ozone data file that are less than zero or greater than or equal to 900.0 will be regarded as missing.
The PVMRM and OLM options for modeling NO2 conversion are non-default options, and only one of these options can be specified for a given model run. Both options require that the pollutant ID be specified as ‘NO2’
Use Ozone Limiting Method : (Model Keyword: OLM) Specifies that the non-default Ozone Limiting Method (OLM) for NO2 conversion will be used.
Use Plume Volume Molar Ratio Method: (Model Keyword: PVMRM) Specifies that the non-default Plume Volume Molar Ratio Method (PVMRM) for NO2 conversion will be used.
Calculate increment consumption with PSD credits: (Model Keyword: PSDCREDIT) Specifies that the EPA Beta test option will be used to calculate the increment consumption with PSD credits using the PVMRM option. This option for is available only when the PVMRM option is selected and is used to account for NO/NO2 chemistry of combined plumes in the computation of increment consumption with PSD credits.
Override default in-stack NO2/Nox ratio: (Model Keyword: NO2STACK) The in-stack NO2/Nox ratio can be specified for the PVMRM or OLM options by selecting this option and specifying a default value (Ratio) to be used for all sources.
Ratio: The default in-stack NO2/Nox ratio that will be used. Value can be a number between 0.0 and 1.0, inclusive.
Override default NO2/Nox ambient equilibrium ratio: (Model Keyword: NO2EQUIL) The PVMRM option for modeling conversion of NO to NO2 incorporates a default NO2/NOx ambient equilibrium ratio of 0.90. Use this option to override the default value.
Ratio: The ratio to be used. Value can be a number between 0.1 and 1.0, inclusive.
Page url: http://www.breeze-software.com/prod/aermod-isc/help/index.html?co_ozone_options.htm