Updates to output file, naming conventions

[kdraeder]

http://www.cesm.ucar.edu/models/cesm2/naming_conventions.html#modelOutputFilenames
says that

a new metadata field called time_period_freq is now written to every history file header with one of the corresponding values:

second_N... N ∈ {1..3599} - data are written every N seconds

...
But this is not true for the cpl.hi. files, which seem to contain
instantaneous values.

It would also be helpful to have either a description of the meaning
of the standard characters that follow .h, (a,i,0-9,...) or pointers to that information,
like
http://www.cesm.ucar.edu/models/cesm2/component_settings/cam_nml.html:fincl1
for the first CAM history file.
Similarly, it would be helpful to update the driver namelist documentation
http://www.cesm.ucar.edu/models/cesm2/component_settings/drv_nml.html:history_option
to note that the output will appear in a .hi. file.
Similarly for the cpl.ha* files.

I wouldn't mind writing some of that documentation,
but I can't find the source code for pages like these.
They are not in the CESM2_0 release.
Thanks,
Kevin

[kdraeder]

@billsacks @gold2718
This issue seems to have not grabbed anyone's attention since I opened it,
maybe because I don't have permission to assign, choose tags, etc.
(see https://github.com/ESCOMP/escomp.github.io #1).
Or maybe it's just way down on the priority list.
So I'm pinging you to make sure someone knows about it (them).
Thanks,
Kevin

[billsacks]

I'm tentatively assigning this to @bertinia . Alice, are you able to look into this?