Opened 2 months ago

Last modified 13 days ago

#2376 assigned Defect

Incorrect restart after the first year of the model run when option 2 of the freshwater-budget adjustment mechanism is active (`nn_fwb = 2`, module `sbcfwb`)

Reported by: smueller Owned by: smueller
Priority: low Milestone:
Component: SBC Version: 4.0-HEAD
Severity: minor Keywords: fwb
Cc:

Description

Context

Output from the model in a variant of the ORCA2_ICE_PISCES reference configuration (OCE without icebergs, ICE unchanged, TOP excluded) exhibits unexpected, apparently unphysical features following a restart after several years of the model run.

Analysis

A test of the restartability at the first model restart failed. Further analysis revealed that upon model restarts, the freshwater-budget adjustment option selected in reference configuration ORCA2_ICE_PISCES (nn_fwb = 2, module sbcfwb) causes the adjustment flux to be read in from file EMPave_old.dat (thus, it is set to the value used during the first year of the model run) rather than to be set to the value appropriate for the previous year of simulation (as it is in continuous model runs).

Recommendation

The freshwater-budget adjustment flux from the previous year should be stored in and recovered from restart files if nn_fwb is set to 2.

Commit History (0)

(No commits)

Change History (4)

comment:1 Changed 6 weeks ago by smueller

  • Owner changed from systeam to smueller
  • Status changed from new to assigned

comment:2 Changed 5 weeks ago by smueller

When nn_fwb = 2, the restartability of model runs longer than one year can be achieved by copying the content of file EMPave.dat produced by the preceding model-run segment to file EMPave_old.dat prior to the model restart. While these two files are described in subection 6.13.6 of the manual for the most recent release version of NEMO, the appropriate restart procedure for option 2 of the freshwater adjustment mechanism is not. To avoid incorrect model restarts as a result of the omission of copying or renaming the EMPave.dat file, the restart capability of this option should be normalised.

comment:3 Changed 13 days ago by clevy

  • Version changed from release-4.0 to release-4.0-HEAD

comment:4 Changed 13 days ago by clevy

  • Version changed from release-4.0-HEAD to 4.0-HEAD
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