Opened 4 years ago

Closed 4 years ago

Last modified 3 years ago

#1742 closed Bug (fixed)

BUG in TVD (FCT) with vvl (non linear free surface) in v3.6_stable (trunk)

Reported by: gm Owned by: nemo
Priority: normal Milestone: 2016 WP
Component: OCE Version: release-3.6
Severity: Keywords: FCT TVD VVL
Cc:

Description

Context

The flux corrected advection scheme of tracer (TVD for v3.6_stable, FCT for the trunk) does not prevent the creation of false extrema when using time varying level thickness (key_vvl defined for v3.6, ln_linssh=false for the trunk).

Analysis

In traadv_tvd.F90 (traadv_FCT.F90 for the trunk) the time integration of the low order scheme does not take into account the change in level thickness. As a result, the anti-diffusive correction is improperly evaluated when a time varying vertical coordinate is use.

Fix

v3.6_stable :

in traadv_tvd.F90, line 182:

 zwi(ji,jj,jk)    = ( ptb(ji,jj,jk,jn) + z2dtt * ztra ) * tmask(ji,jj,jk)

should be replaced by

 zwi(ji,jj,jk)    = ( fse3t_b(ji,jj,jk)*ptb(ji,jj,jk,jn) + z2dtt * fse3t_n(ji,jj,jk)*ztra ) / fse3t_a(ji,jj,jk) * tmask(ji,jj,jk)

trunk :

in traadv_fct.F90, line 158:

zwi(ji,jj,jk)    = ( ptb(ji,jj,jk,jn) + p2dt * ztra ) * tmask(ji,jj,jk)

should be replaced by

 zwi(ji,jj,jk)    = ( e3t_b(ji,jj,jk)*ptb(ji,jj,jk,jn) + z2dtt * e3t_n(ji,jj,jk) * ztra ) / e3t_a(ji,jj,jk) * tmask(ji,jj,jk)

Gurvan and Simona

Commit History (4)

ChangesetAuthorTimeChangeLog
6706huwlewis2016-06-14T12:49:06+02:00

Commit simple mask scaling for sent SST field for #1742

6705huwlewis2016-06-14T12:45:08+02:00

Create a branch for #1742 land/sea sst mask in sent field

6692flavoni2016-06-13T16:39:24+02:00

#1742, commit correction on advection scheme TVD

6691flavoni2016-06-13T16:37:49+02:00

#1742, commit correction on advection scheme FCT

Change History (6)

comment:1 Changed 4 years ago by flavoni

Bug seen via implementation of Lock Exchange test case, with vvl (in both trunk and in version 3.6_stable) there was extrema of temperature.

For 36stable committed correction, see revision 6692

For trunk committed correction, see revision 6691

comment:2 Changed 4 years ago by flavoni

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

comment:3 Changed 4 years ago by nicolasmartin

  • Keywords VVL added; vvl removed

comment:4 Changed 4 years ago by nicolasmartin

  • Keywords 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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