Restarting the Coupled Model

Restart Control Parameters and Settings

	FV3	CMEPS	MOM6	CICE6	WW3
restart control: creating a restart during model run	model_configure: restart_interval. Give the value in hours. Set 0 to write a restart only at the end.	nems.configure: restart_n and restart_option. For example, use restart_n = 48 and restart_option = nhours to write a restart every 48 hours	nems.configure: restart_n and restart_option	nems.configure: restart_n and restart_option	ww3_multi.inp: the checkpoint restart line needs to be updated with desired frequency of restart, time to start restarts and time to end restarts.
restart filenames	checkpoint restarts are named timestamp.filename.nc. Final restarts are named filename.nc	ufs.s2s.cpl.r.timestamp.nc	checkpoint restarts are named MOM.res.timestampX.nc, where X=(none,_1,_2 etc) depending on file size. Final restarts are named MOM.resX.nc	iced_timestamp.nc	${YYYYMMDD}.${HH}0000.restart.${ww3grid} where YYYYMMDD is the year month and day and HH is the hour of the valid time of the restart and ww3grid is the WW3 grid extension
restart write location	RESTART	RESTART. Controlled in nems.configure using case_name = ./RESTART/ufs.s2s	RESTART. Controlled in MOM_input_nml (located in input.nml) using restart_output_dir = 'RESTART/'	RESTART. Controlled in ice_in, using restart_dir = ./RESTART	main run directory
input location for restart runs	INPUT	INPUT. Use rpointer.cpl in run directory to specify filename and location	INPUT. Use restart_input_dir in MOM_input_nml (located in input.nml) to specify location	INPUT. Use ice.restart_file in run directory to specify filename and location	The ${YYYYMMDD}.${HH}0000.restart.${ww3grid} needs to be renamed to restart.${ww3grid} and it is read from the main run directory
input files for restart runs	coupler.res fv_core.res.nc fv_core.res.tile[1-6].nc fv_srf_wnd.res.tile[1-6].nc fv_tracer.res.tile[1-6].nc phy_data.tile[1-6].nc sfc_data.tile[1-6].nc	ufs.s2s.cpl.r.timestamp.nc rpointer.cpl where timestamp is the time of the restart. The file name and path is stored in rpointer.cpl for use when restarting the model.	MOM.res_1.nc MOM.res_2.nc MOM.res_3.nc MOM.res.nc Note the actual number of files depends on MOM6 resolution. For 1 deg and 1/2 deg, there is a single MOM.res.nc restart file. For 1/4 deg, there are 4 MOM.res().nc files.	iced.timestamp.nc ice.restart_file where timestamp is the time of the restart. The file name and path is stored in ice.restart_file for use when restarting the model.	restart.${ww3grid}
restart trigger	Set fhrot as described below and set input.nml parameters: warm_start =.T. make_nh =.F. na_init = 0 external_ic = F nggps_ic = F mountain = .T.	Set start_type = continue in nems.configure	Set input_filename ='r' in MOM_input_nml (located in input.nml). MOM6 will expect a restart file with root name MOM.res in INPUT	Set runtype ='continue' and use_restart_time =.true. in ice_in	If restart file is in run directory, it will be used. Otherwise WW3 will cold start.

Model Configure and fhrot

1 day run: 2012-01-01-00 → 2012-01-02-00	1 day run: 2012-01-02-00 → 2012-01-03-00
model configure: start_year: 2012 start_month: 01 start_day: 01 start_hour: 00 start_minute: 0 start_second: 0 nhours_fcst: 24 restart_interval: 24 fhrot: 0	model configure: start_year: 2012 start_month: 01 start_day: 01 start_hour: 00 start_minute: 0 start_second: 0 nhours_fcst: 48 restart_interval: 24 fhrot: 24
In nems.configure, set: stop_n = 24 restart_n = 24 restart_option = nhours start_type = startup	In nems.configure, set: stop_n = 24 restart_n = 24 restart_option = nhours start_type = continue