The Community Multiscale Air Quality Modelling System (CMAQ) is a suite of air quality modelling programs used worldwide to produce air quality model simulations. In many cases, the output from the model is in the format of a NetCDF3-based "IOAPI" file (hereafter, IOAPI file).An IOAPI file stores its spatial information in the file in a format that is not currently supported by Esri’s NetCDF suite of tools, i.e. the IOAPI file spatial information does not following CF convention.
Because of this, ArcGIS as a visualization tool for Air Quality modelling results (such as mapping and animations) is not widely utilized and often abandoned in favour of open-source programs such as Verdi that can readily read-in model output files. The downfall of these open source programs is, however, that the data mapping are not as professional or customizable as ArcGIS allows, and the user is quite limited in what they can do to explore the data and to produce information-rich maps.
It would be excellent if Esri could expand the NetCDF tools to accept IOAPI file inputs. I'm certain that if this was done, many more people in the Air Quality modelling community would leverage Esri software for their analysis and visualizations in lieu of the open source programs. ArcGIS is very powerful and capable of so many different things that are very relevant to this community that Esri needs to take some steps that will help to facilitate the use of their software by the users in this community.