Need flexible output times for ocean model

[pjpegion]

Description

When starting the coupled model from the end of the IAU window (FHR03), the ocean daily output becomes 03Z to O3Z averages.
This also messes up the writing of the 6-hourly data since instead of creating 00Z,6Z,12Z, and 18Z files, it creates 03Z, 09Z,15Z,21Z files.

Solution

I would like to see a flag that we can pass to the ocean model to accumulate averages, write out files based on the clock and not just from forecast hour.

[jiandewang]

@pjpegion "the ocean daily output becomes 03Z to O3Z averages." is there a typo here ? do you mean it becomes 03-09Z average ?
Early version of FMS only has the capability of output file names with time stamp as the middle of the integration (and this is what we are using in diag_table). But in FMS2 it can do for the beginning, middle and end of time integration.

[pjpegion]

@jiandewang, not a typo. In a cold start the daily average is from 0Z to 0Z the next day. In a warm start at 3Z, the daily average is 03Z to 03Z the next day.

This is the time bounds from the ocn_daily_2016_01_04.nc file from a warm start (which starts at 3Z):
time_bnds = 0.125, 1.125 ; days since 2016-01-04 00:00:00

and cold start:

time_bnds = 0, 1; days since 2016-01-04 00:00:00

I understand what you are saying with FMS2 having more flexibility with regards to file names, but does it also have more flexibility for when the averaging period should start?

[jiandewang]

for example, if IC is 2016100300Z, and we run model for 6 hr, in diag_table

"ocn%4yr%2mo%2dy%2hr", 6, "hours", 1, "hours", "time", 6, "hours", "1901 1 1 0 0 0", 0, "", "begin"

The last column can be "begin", "middle", or "end". The output files will then be named, for example, as

for "begin" ocn_2016_10_03_00.nc for time bound [0,6]
for "middle" ocn_2016_10_03_03.nc for time bound [0,6]
for "end" ocn_2016_10_03_06.nc for time bound [0,6]

If the field is left blank, FMS will default to "middle".

[pjpegion]

but does that change the beginning of the averaging window?

[jiandewang]

@pjpegion
so you have a warm start at 03Z, then run 24hr, but you only want to average from 03Z-00Z(next day), is my understanding right ?

[pjpegion]

Sort of, I wan't the 1st day to be an average of 03Z to 00Z since that is all we have, and then the 2nd day's value would be 0Z-0Z average, and so forth.

[jiandewang]

I am afraid FMS doesn't have this kind of capability but we can seek help or propose a feature request from FMS group.

[jiandewang]

I asked a similar "monthly" averaged question on FMS, just forwarded you the email from FMS group

[JessicaMeixner-NOAA]

An issue in MOM6 was created: mom-ocean/MOM6#1564

[JessicaMeixner-NOAA]

@jiandewang suspects this is a current limitation with FMS. @junwang-noaa if this is a feature we need in FMS, what would the next steps be?

[junwang-noaa]

@JessicaMeixner-NOAA @jiandewang Please create an issue at GFDL FMS repo: https://github.com/NOAA-GFDL/FMS.

[jiandewang]

@junwang-noaa just created an issue, see NOAA-GFDL/FMS#956

[jiandewang]

updating from FMS group: NOAA-GFDL/FMS#1077 (comment)

[jiandewang]

from "uramirez8707": unfortunately this feature is only going to be available for diag_table.yaml and the new diag_manager, which won't be production for at least a couple of months. (see NOAA-GFDL/FMS#1077 (comment))

[DeniseWorthen]

@jiandewang Do you know when this feature might be available?

[jiandewang]

@jiandewang Do you know when this feature might be available?

no I have not got any updating from FMS group