AirWare   On-line Reference Manual

  Release Level 5.4
  Release Date 2008 10
  Revision Level 1.0
Last modified on:   Monday, 20-Jul-09 14:03 CEST

Steady-state scenarios

Scenarios for the air quality models including the steady state models (AERMOD/ISC3) are named objects, selectd from a model specific scenario selector/navigator, and generated with a. separate scenario generator/editor. The selector for a meteo scenario shows the following characteristics: scenario name, geographic location (model domain), owner, last modifications date, start date, time step. The selector also includes a NEW button to generate a new scenario.

Editing a scenario

Once selected from the list, a summary of the scenario is shown. This include a header with name, description, owner, creation and last modification dates.

A primary attribute of the steady-state model scenario is the domain or location that is shown right under the header. The domain is read-only, and can only be selected when generting a NEW SCENARIO A MAP with the extent of the model domain is also shown.

A second basic attribute is the start date and time. In the case of the steady-state models, this refers to a period of one hour. This can be modified by the user within the constraints of data availability (temporal coverage) for the meteorological scenario selected.

The steady-state scenarios consist of

  1. A Model Domain (selected from a list (navigator) of applicable DOMAIN OBJECTS;

  2. A Meteorological Scenario:meteo data set selected from a meteorological scenario or data set which is a synchronized complete and consistent set of meteorological parameter time series generated with a meteo pre-processor; the set of synchronized meteorological parameter time series can be visualized in a separate pop-up window.
    Meteorological data sets are named OBJECTS that are derived from the monitoring data from an applicable (nearbey) meteorological station, the interpolation of several station, of from some meteorological model or pre-processor.
    Meteorological scenarios are generated by an separate Meteorological Scenario Generator that ensure synchronization and consistency of the meteorological time series data.
    The Meteorological Scenario Data applicable for the steady-state (episode) models must have a 1hour resolution or time step.

  3. A choice of pollutant from a list of applicable pollutants the model can represent;

  4. An Emission scenario (dynamically generated) for that pollutant; One or more emission sources selected by their location within the domain of the scenario; Emission sources are grouped into:
    • point sources
    • area sources
    • line sources.
    For each point source, the list includes the set of stack parameters (constant) and the emisison value for the pollutant selected, generated by the emission pre-processor for the date/time selected.
    For area sources, only their height is shown together with the emisison value.
    For line sources, only the emission value is shown.

    Each source listed will link to the corresponding SOURCE OBJECT in the emission data base. For each emission value, the listing indicates whether the value was observed or estimated from the average value and temporal scaling factors.

    For each emission value, the user can specify a multiplier and an additive term to modify the emission pattern for scenartio analysis.

User options within the scenario include therefore:
  1. Choice of pollutant;
  2. Choice of start time;
  3. Scaling of the emissions (multiplicative and additive term for each source or globally).
Please note that the emission data are automatically be loaded from the emission inventory, directly from available monitoring time series, or generated from each source's average emission value and the temporal scaling factors.

Comparison and data assimilation, calibration

Optional functions constrained by data availability include:
  • the comparison with observation data
  • data assimilation
  • model calibration
  • exposure analysis.

Defining a NEW Scenario

For a NEW scenario, the user can define:
  1. The domain from a pull-down menu of available domains with pre-processed DEM data;
  2. For each domain, one of an optional set of applicable meteorological monitoring stations; Once a station has been selected, the default start date is the most recent date from which a complete and consistent data set can be constructed for the duration of the episode.


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