air quality assessment & management
Reference and User Manual
AirWare   On-line Reference Manual
  Release Level 7.0
  Revision Level beta
  Release Date 2015 03

Last modified on:   Sunday, 19-Jul-15 21:56 CEST

Coupling of MM5 with CAMx

Coversion of meteorological fields computed with MM5 to CAMx inputs is done using the MM5CAMx post-processing program, available on-line from:

The program is written assuming hourly MM5 output and generates hourly CAMx inputs. Horizontal interpolation gives option to interpolate MM5 output on the CAMx grid defined on a UTM projection of any resolution, as long as it fits within the area defined by outer rows/columns of MM5 "cross" points. MM5CAMx interpolates all needed variables to CAMx grid cell centers.

The CAMx physical height layer structure (meters AGL) is defined from the MM5 sigma-p layer structure, and thus varies in space. Vertical averaging of MM5 layers to a coarser CAMx layer structure is allowed. The set of MM5 layers to combine into CAMx layers is specified in the script file. Variables in each MM5 layer are mass-weighted to each bulk CAMx layer.

The 4D meteorological fields for CAMx provided from MM5 output are:

    CAMx Z-P file CAMx height/pressure input file
    CAMx Wind file CAMx u, v wind components input file
    CAMx Temp file CAMx temperature input file
    CAMx Kv file CAMx vertical diffusivity input file
    CAMx Water file CAMx vapour input file
    CAMx Cld/rain file CAMx cloud/rain input file
The MM5 output file ( MMOUT_DOMAIN ) file for one day for the DOMAIN specified in mm5grid.txt must be present.

For a single day, 25 hours of meteorology must be present (midnight through midnight, inclusive) as these fields represent hourly instantaneous conditions and CAMx internally time-interpolates these fields to each model time step. Longer simulatiopn/forecast periods are implemented as a sequence of 24 hour days.

Please note that the vertical discretization resolution using in each application is described in the respective Installation Notes.

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