Initial condition for Chemical constituents for CMAQ


Can anybody suggest me where to get actual initial condition data for the chemical constituents for CMAQv5.3? By that I mean a complete set of data including emissions etc. Is there such an inventory of data freely available?

If not, could you hint a little on what steps to follow to get the complete set of chemical data (except for meteorology which I can produce from WRF) to initialize the model.

I am planning to run CMAQ at about 1 km (a part of CONUS).



I am not sure which model year are you running the CMAQ. Following things are what I usually do:

  1. ICBC:
    a) from NOAA MOZART output
    you can download MOZART output here, which is a global air quality model

you can then convert these data into CMAQ IC/BC by mozart2cams, please see following link

b) if you can obtain GEOS chem data, you can convert these data into CMAQ format by

c) if you can obtain hemi domain CMAQ output you can create you IC BC by icon and bcon in PREP

  1. Inventory data:
    EPA released all inventory data
    for example, this one includes all 2011 information that are SMOKE input ready

However, most of these data are in 12US1 (12km) or larger (36km) resolution (some cases EPA released 4km surrogate files), if you would like to run for 1km you have to generate 1km surrogate files

Also EPA will release 2016 EMP CMAQ input ready data for 12US1 here

Hope this helps


Many hanks for these links! I will try to work with them.


I want to compile and run mozart2camx. Could you guide me on how to do that, please?
Thank you

Best regards,

Hello Ensiyeh,

the mozart2camx program is not part of the CMAQ suite of tools and is not supported by the CMAS center or the CMAQ development team. For questions regarding the program, we suggest following the instructions on the page where you downloaded the tar file:

"Support Software

This page contains links to CAMx pre- and post-processors and other tools. These source codes are distributed by Ramboll as free software, and they contain notices like this:

Copyright © 2016-2019 Ramboll
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

Ramboll occasionally posts updates for certain widely-used programs when necessary, but does not actively support or maintain every one. Users can e-mail questions, comments, suggestions or improvements to CAMx."

Hi Christian

I know, but they didn’t answer me and I didn’t find another way to solve it. So I decided to ask it from people who compiled and run it. Could you help me, please?
Thank you

Hi Ensiyeh,

unless your question is specifically related to errors you are encountering when compiling the program and linking in the required netCDF and I/O API libraries, it is unlikely that the CMAS center or CMAQ development team would be able to help, although it is certainly possible that other users (such as @huangj1311) have used this tool in their work and might have additional insights.

Your post does not contain sufficient details to judge what you have already tried, what problems you are encountering, and what guidance you are seeking. General guidance on how to compile and run mozart2camx is beyond what either the CMAS center team or the CMAQ development team can provide because, to the best of my knowledge, no one from either team is using this tool for their work and because we are not the developers or maintainers of this tool.

I see that you also posted your question in a third thread and that @cjcoats provided a response in that thread. His response fits the exception I noted above - you can expect support on this forum if you are encountering problems with compiling code that requires the I/O API library.