cstream in history file names

[dabail10]

I just realized this was commented out again. We do need the numbers after the 'h' in the history file names. I know this breaks post-processing in other applications, but we really need this in CESM. I would like to propose a namelist flag for this. Something like a logical hist_num?

[apcraig]

Could you clarify. Is this something in the nuopc driver or elsewhere?

[dabail10]

This is in the ice_history_shared.F90 module in construc_filename.

[phil-blain]

Basically, this code:

CICE/cicecore/cicedyn/analysis/ice_history_shared.F90

Lines 763 to 766 in a5bb4f9

	cstream = ''
	!echmod ! this was implemented for CESM but it breaks post-processing software
	!echmod ! of other groups (including RASM which uses CESMCOUPLED)
	!echmod if (ns > 1) write(cstream,'(i1.1)') ns-1

This has always been commented in CICE6. In fact it was commented out ever since it was added in CICE-Consortium/CICE-svn-trunk@c53339b (Merge from cesm_cice branch into trunk, r992:1074., 2015-11-11).

I think it makes sense to have a namelist option for this.

Additionally, it it an easy way to fix a "bug" (or limitation) of the history code that I just discovered, that is the following settings currently do not work:

    histfreq       = 'd','h','x','x','x'
    histfreq_n     =  1 , 1 , 1 , 1 , 1
    hist_avg       = .false.,.false.,.true.,.true.,.true.
...
    f_aice         = 'd'
    f_hi           = 'h'

As soon as two streams are set to instantaneous output, then the last defined stream "wins", so a run with the above settings would have only f_hi hourly outputs but no concentration output, since the file from the second stream overwrites the file from the first stream, because they have the same filename.

Having cstream in the filename would be an easy way to make such a configuration work. I can work on that.

[dabail10]

This would be great! One note here. The streams will only have the same file name if they are the same histfreq. So, if you had two daily streams, this would be a problem.