Hi wfy,
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.
Cheers,
David