AirWare   On-line Reference Manual

  Release Level 5.4
  Release Date 2008 10
  Revision Level 1.0
Last modified on:   Tuesday, 29-Nov-11 11:49 CET

Model Scenarios: CAMx

A CAMx scenario is a named OBJECT that compiles, displays, and suports editing of model scenarios.
Model scenarios can be:
  • Scenarios proper, based on user defined set of input parameters;
  • Now-casting scenarios, automatically run every hour, driven by real-time meteo data feeds, using the previous hourly result as initial condition,
  • Fore-casting scenarios, automatically run every 24 hours, driven by a 24 hour meteorological forecast, using the applicable now-casting result for inital conditions.

Model implementation

CAMx is implemented for a pre-defined master domain covering an area large enough to account for the air flow during the 48 hour simulation period at a relatively coarse resolution e.g., 2 km; and a number of sub domains covering areas of specific interest like major settlements or industrial areas, at a finer resolution, e.g., 500 m.

Computations for the sub-domains can be switched on or off by the user.

Scenario Parameters

The following parameters define a CAMx scenario:

Scenario parameter Comment
Start date/time user selectable, subject to the availability of input data in the meteo scenario
Duration of simulationfixed at 1 hour for nowcasting, 48 hours for forecasting and scenario runs
Master Domain Fixed to the applicvation domain, e.g., Cyprus
Main Grid resolution scalar [m]; fixed to maintain consistency with all matrix pre-processors
Subdomainsuser selectable from a list of (possibly user defined)   domains
Subdomain Grid resolutionfixed for performance reasons, scalar [m], e.g., 500
Vertical grid structurenumber of layers, layer interface heights [m]; pre-defined at the application level, read only
Chemistry mechanismsuser selectable:
  • conservative gas (NOx or SO2)
  • conservative particulate matter (PM < 2.5 micrometer
  • conservative particulate matter (PM > 2.5 micrometer
  • simple chemistry SO2/H2SO4
  • simple chemistry NO/NO2
  • CB4 (gas phase chemistry, 96 reactions and 37 species)
  • CB4/CF (CB4 including Aerosol chemistry, 117 reactions and up to 67 species)
Output layers only bottom layer or 3 dimensional output, default: bottom layer only
Output time stepscalar [min], default is 60 minutes
Output pollutantsdefined through the chemistry mechanism, fixed for conservative and simple chemistry; variable only for chemistry mechanisms CB4 and CB4/CF; there a list of chemical species is given; default setting
Meteo scenariouser selectable, constrained by domain, model specific
Emission scenariodynamically generated for the domain and period, model resolution (for gridded data) and chemistry mechanism that defines the set of pollutant emissions required)
Initial conditions3D matrix for at least one chemical species, selected from the set of matrix objects
Lateral boundary conditionsFour 2D matrices for at least one chemical species
Top concentrationsUpper boundary condition: scalar for at least one chemical species
Restart true or false, if 'true' CAMx uses instanteous concentration files of preceding run instead of initial concentration file; default in true for nowcasting and forecasting)
Error Checktrue/false 'true'=will stop after 1st timestep; default set of false
Maximum timestepscalar [min], default set to 15 minutes
Dry depositiontrue/false, default set to true
Wet depositiontrue/false, default set to true
PiG Submodelpossible values: None, GREASD, IRON, default set to None
Map projectionPossible values: LAMBERT, POLAR, UTM, LATLON, default set to UTM
UTM Zonedefined by the main domain
Advection SolverPossible values: PPM, BOTT, default set to PPM
Chemistry SolverPossible values: CMC, IEH, LSODE, default set to CMC
Probing Toolpossible values: None, OSAT, PSAT, GOAt, APCA, DDM, PA, RTRAC, default set to None
Staggered windstrue/false, default set to false
Gridded Emissionstrue/false, default is set to true
Point Emissionstrue/false, default set to true
Ignore Emission Datestrue/false, default set to true


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