Opened 5 years ago

Closed 5 years ago

Last modified 3 years ago

#1591 closed Bug (fixed)

why correction for runoff (useless with core forcing files) in sbcrnf.F90

Reported by: flavoni Owned by: flavoni
Priority: low Milestone: 2015 release-3.6
Component: OCE Version: release-3.6
Severity: Keywords: 2015
Cc:

Description

I report a question of  Calvert, Daley :Hi all, I’m a bit puzzled by the following hand edit in sbcrnf.F90 (present in both NEMO 3.4 STABLE and NEMO 3.6 STABLE):sbcrnf.F90

128 ! Runoff reduction only associated to the ORCA2_LIM configuration
129 ! when reading the NetCDF file runoff_1m_nomask.nc
130 IF( cp_cfg == 'orca' .AND. jp_cfg == 2 .AND. .NOT. l_rnfcpl ) THEN
131 WHERE( 40._wp < gphit(:,:) .AND. gphit(:,:) < 65._wp )
132 sf_rnf(1)%fnow(:,:,1) = 0.85 * sf_rnf(1)%fnow(:,:,1)
133 END WHERE
134 ENDIF

Can anyone explain why this is used?

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all_plot.pdf (5.6 MB) - added by flavoni 5 years ago.

Change History (7)

Changed 5 years ago by flavoni

comment:1 Changed 5 years ago by flavoni

File runoff_1m_nomask.nc is very very old, in ORCA2_LIM tar file before 2006. Correction was done for this file (why?).

Starting from COREII forcing files this correction was not still necessary for runoff forcing file runoff_core_monthly.nc.

I removed the correction in sbcrnf.F90, I run 10 years of simulation, and in attach are plots of differences between "NOcorrect" without correction between 40°N and 65°N, and "oldrnf" with old correction, after 10 year of simulation.

Differences are very small, but I leave ticket open because we want to decide how to proceed.

Sebastien suggestion:

"I think runoff_1m_nomask.nc for ORCA2 was never changed for a very long time (I would said from its creation sometime in 2000 or 2001)… A small research in the old tar files for ORCA2 could help to confirm this.So to me, if we want to keep the ORCA2 simulations unchanged (open question), a good solution would be to- modify the file runoff_1m_nomask.nc (or whatever name we are now using) according to lines 131-133 of sbcrnf.F90- remove those hard coded modifications in the code!Same idea could/should be applied to all modifications done on the coordinates file in domhrg for exampleSeb"

comment:2 Changed 5 years ago by flavoni

  • Owner changed from NEMO team to flavoni

comment:3 Changed 5 years ago by flavoni

  • Resolution set to fixed
  • Status changed from new to closed

I had not answer, so I do:

I remove the correction because I thinnk it is not necessary with the runoff file in input tarf file (creating by coreII input files)?
We will not have same results, but the correction is not longer necessary for the runoff file, so I think it is usefuless doing two corrections where the second is not necessary just to have same results.

So I remove the lines in version 3_6 stable revision 6087

comment:4 Changed 4 years ago by nicolasmartin

  • Keywords 2015 nemo_v3_6* added

comment:5 Changed 3 years ago by nemo

  • Keywords release-3.6* added; nemo_v3_6* removed

comment:6 Changed 3 years ago by nemo

  • Keywords release-3.6* removed
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