I’m currently working on replacing the photolysis rates table in CMAQ with data from netcdf files. I’ve modified the ‘phto.F’ file to read the necessary variables from a netcdf file , but I’ve encountered an issue when running the model in parallel. It seems that the grid isn’t being properly divided, and I’m unsure how to resolve this.
I think the ‘centralized_io_module.F’ file handles input data, but it’s quite complex, and I’m not sure how to correctly add the new variables. Does anyone have experience with this or know if there’s a template I could refer to?
I’ve attached my modified ‘phto.F’ file, and the photolysis rate file has already been set as XJ_DATA’ in the run script. Any guidance would be greatly appreciated!
The principle of centralized I/O is to have all the input done, including opening the file and reading in data, within a module (centralized) and the data will be available to any science processes inside the CMAQ model. To add some new inside centralized_io_module.F is not that complicated (I plan to create a user guide and make it available to the community in this summer). There are two considerations: 1. time independent data, and 2. time dependent data. For case 1, you can create a list of new variables and follow the same way as the variable ocean or szone are being handled. For case 2, you can follow the same way we handle lightning data ‘lnt’ or wind blown dust ‘wb’. If you are not comfortable modifying centralized_io_module.F, please send me your copy of the file directly, wong.david-c@epa.gov and I will modify it for you. Of course, you can read in the data in phot.F which will break the principle of centralized I/O. Please let me know which way you prefer and I will assist you.
By the way, I am curious to know why you are still interested in bring in photolysis rate from a file rather than utilizing the inline process, which is the main method for years.