run_roms_da data assimilation script

[jpm]

I created a script called run_roms_da that may be useful for those performing ROMS data assimilation and running multiple consecutive 4DVar cycles.

This script has been created a while ago and is now used by several people in our UCSC data assimilation group. It has become more sophisticated over time and can do a lot more than the `submit_is4dvar.bash` script that comes with ROMS.

The highlights:

• fully automated file renaming
• starting of ROMS via mpirun or sbatch job submission
• slicing of observation files to fit each 4DVar cycle
• fully configurable using a single configuration file for each assimilation run (unlike `submit_is4dvar.bash`, the script itself is not edited by the user)
• restart from failed runs
• written fully in bash, it only requires an installation of the NCO toolkit (for ncks, ncap2, etc.)
• optional compression of ROMS output after each cycle

While it can do a lot, this script does require a working ROMS 4DVar configuration (executable, forcing and observation files etc.). More information can be found on its github page.

Feel free to ask questions about it here, if I see some interest, I'll expand its documentation on github. If you are encountering issues, please post an issue on the github page page.