#2406 closed Bug (fixed)
Bugs in tke with ice shelves
| Reported by: | mathiot | Owned by: | mathiot |
|---|---|---|---|
| Priority: | high | Milestone: | |
| Component: | ZDF | Version: | v4.0.* |
| Severity: | critical | Keywords: | ISF, TKE |
| Cc: |
Description
Context
- If tke switch on, nn_pdl == 1 and ice shelf cavities opened, cells at the ocean/ice shelf interface are warming and freshening over time to reach unrealistic temperature and salinity even without any melting/freezing at the ice shelf/ocean interface.
Analysis
- avt is wrongly masked in the top cells. tmask is used instead of wmask in tke.
- In the mean time, I found some bugs in the computation of en(:,:,1):
- en(jk=1) overwritten to different value when top and bottom drag contribution included (only if ice shelf cavities opened)
- case \ln_drg = .false. and ln_OFF = .true. in namdrg\ gives a different result (ORCA2) than \ln_drg = .true. and ln_OFF = .true. in namdrg\.
This is affecting NEMO v4 and the trunk.
Fix
Avt masking (zdftke):
@@ -517,7 +517,7 @@ ! IF( nn_pdl == 1 ) THEN !* Prandtl number case: update avt DO_3D_00_00( 2, jpkm1 ) - p_avt(ji,jj,jk) = MAX( apdlr(ji,jj,jk) * p_avt(ji,jj,jk), avtb_2d(ji,jj) * avtb(jk) ) * tmask(ji,jj,jk) + p_avt(ji,jj,jk) = MAX( apdlr(ji,jj,jk) * p_avt(ji,jj,jk), avtb_2d(ji,jj) * avtb(jk) ) * wmask(ji,jj,jk) END_3D ENDIF
en surface value:
We should first set up the value at surface (level 1). If ln_drg = .fasle., en(ji,jj,mikt(ji,jj)) is initialised to 0 as en(ji,jj,mbkt(ji,jj)+1) is.
@@ -213,15 +213,10 @@ ! !<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< ! ! Surface/top/bottom boundary condition on tke ! !<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< - + ! DO_2D_00_00 en(ji,jj,1) = MAX( rn_emin0, zbbrau * taum(ji,jj) ) * tmask(ji,jj,1) END_2D - IF ( ln_isfcav ) THEN - DO_2D_00_00 - en(ji,jj,mikt(ji,jj)) = rn_emin * tmask(ji,jj,1) - END_2D - ENDIF ! ! !<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< ! ! Bottom boundary condition on tke
If ln_drag, en(ji,jj,mikt(ji,jj)) should be modified only beneath the ice shelves otherwise it will overwrite the ocean surface (jk=1) value. So we need to use tmask(ji,jj,1) and (1._wp - tmask(ji,jj,1)) * ssmask(ji,jj) to separate case under ice shelf and in open ocean.
@@ -248,7 +248,7 @@ ! ! where 0.001875 = (rn_ebb0/rho0) * 0.5 = 3.75*0.5/1000. (CAUTION CdU<0) zetop = - 0.001875_wp * rCdU_top(ji,jj) * SQRT( ( zmsku*( uu(ji,jj,mikt(ji,jj),Kbb)+uu(ji-1,jj,mikt(ji,jj),Kbb) ) )**2 & & + ( zmskv*( vv(ji,jj,mikt(ji,jj),Kbb)+vv(ji,jj-1,mikt(ji,jj),Kbb) ) )**2 ) - en(ji,jj,mikt(ji,jj)) = MAX( zetop, rn_emin ) * (1._wp - tmask(ji,jj,1)) ! masked at ocean surface + en(ji,jj,mikt(ji,jj)) = en(ji,jj,1) * tmask(ji,jj,1) + MAX( zetop, rn_emin ) * (1._wp - tmask(ji,jj,1)) * ssmask(ji,jj) ! masked at ocean surface END_2D ENDIF
The MAX( zebot, rn_emin ) used to compute the bottom and top boundary condition due to drag (case ln_drg = .true. in tke namelist) leads to different result between the case:
- ln_drg = .false. and ln_OFF = .true. in namdrg => bottom boundary is 0.0 (initialisation)
- ln_drg = .true. and ln_OFF = .true. in namdrg => zebot = 0 => bottom boundary is rn_emin
I think both cases should give the same answer. I changed MAX( zebot, rn_emin ) by zebot (ie initialised bottom boundary condition to 0.0) and in this case both simulations gave the same results ().
Commit History (10)
| Changeset | Author | Time | ChangeLog |
|---|---|---|---|
| 12703 | mathiot | 2020-04-07T11:18:07+02:00 | ticket #2406: too long line (> 132 cols) |
| 12702 | mathiot | 2020-04-07T11:16:52+02:00 | ticket #2406: too long line (> 132 cols) |
| 12700 | mathiot | 2020-04-06T21:17:55+02:00 | ticket #2406: delete temporary branch (ticket2406_r4.0-HEAD) |
| 12699 | mathiot | 2020-04-06T21:15:07+02:00 | ticket #2406: delete temporary branch |
| 12698 | mathiot | 2020-04-06T21:10:53+02:00 | |
| 12697 | mathiot | 2020-04-06T20:14:06+02:00 | |
| 12696 | mathiot | 2020-04-06T20:09:58+02:00 | ticket #2406: implement changes (r4.0-HEAD version of the ticket branch) |
| 12694 | mathiot | 2020-04-06T20:03:23+02:00 | ticket #2406: implement changes (no changes in results as isf and tke not tested by SETTE) |
| 12693 | mathiot | 2020-04-06T18:35:37+02:00 | |
| 12543 | mathiot | 2020-03-12T18:19:00+01:00 | create branch for ticket #2406 (tke and isf) |
Change History (16)
comment:1 Changed 3 years ago by mathiot
comment:2 Changed 3 years ago by clevy
- Version changed from v4.0 to v4.0.*
comment:3 Changed 3 years ago by davestorkey
Review: I agree with the proposed changes apart from I'm not sure we need ssmask in this line:
en(ji,jj,mikt(ji,jj)) = en(ji,jj,1) * tmask(ji,jj,1) + MAX( zetop, rn_emin ) * (1._wp - tmask(ji,jj,1)) * ssmask(ji,jj) ! masked at ocean surface
Agreed with Pierre that the last point he raises can be left open in a new ticket.
comment:4 Changed 3 years ago by davestorkey
Review: I agree with the proposed changes apart from I'm not sure we need ssmask in this line:
en(ji,jj,mikt(ji,jj)) = en(ji,jj,1) * tmask(ji,jj,1) + MAX( zetop, rn_emin ) * (1._wp - tmask(ji,jj,1)) * ssmask(ji,jj) ! masked at ocean surface
Agreed with Pierre that the last point he raises can be left open in a new ticket.
comment:5 Changed 3 years ago by mathiot
ssmask is needed to be sure 'en' at the top interface is 0 where there is no ocean.
comment:6 Changed 3 years ago by mathiot
In 12693:
comment:7 Changed 3 years ago by mathiot
Sette results (same results for the fix in the r4.0-HEAD):
Current code is : NEMO/branches/2020/ticket2406_trunk @ r12692 ( last change @ r12692 )
SETTE validation report generated for :
NEMO/branches/2020/ticket2406_trunk @ r12692+ (last changed revision)
on XC40_METO_IFORT arch file
!!---------------1st pass------------------!!
!----restart----!
WGYRE_PISCES_ST run.stat restartability passed : 12692+
WGYRE_PISCES_ST tracer.stat restartability passed : 12692+
WORCA2_ICE_PISCES_ST run.stat restartability passed : 12692+
WORCA2_ICE_PISCES_ST tracer.stat restartability passed : 12692+
WORCA2_OFF_PISCES_ST tracer.stat restartability passed : 12692+
WAMM12_ST run.stat restartability passed : 12692+
WORCA2_SAS_ICE_ST run.stat restartability passed : 12692+
WAGRIF_DEMO_ST run.stat restartability passed : 12692+
WSPITZ12_ST run.stat restartability passed : 12692+
WISOMIP_ST run.stat restartability passed : 12692+
WOVERFLOW_ST run.stat restartability passed : 12692+
WLOCK_EXCHANGE_ST run.stat restartability passed : 12692+
WVORTEX_ST run.stat restartability passed : 12692+
WICE_AGRIF_ST run.stat restartability passed : 12692+
!----repro----!
WGYRE_PISCES_ST run.stat reproducibility passed : 12692+
WGYRE_PISCES_ST tracer.stat reproducibility passed : 12692+
WORCA2_ICE_PISCES_ST run.stat reproducibility passed : 12692+
WORCA2_ICE_PISCES_ST tracer.stat reproducibility passed : 12692+
WORCA2_OFF_PISCES_ST tracer.stat reproducibility passed : 12692+
WAMM12_ST run.stat reproducibility passed : 12692+
WORCA2_SAS_ICE_ST run.stat reproducibility passed : 12692+
WORCA2_ICE_OBS_ST run.stat reproducibility passed : 12692+
WAGRIF_DEMO_ST run.stat reproducibility passed : 12692+
WSPITZ12_ST run.stat reproducibility passed : 12692+
WISOMIP_ST run.stat reproducibility passed : 12692+
WVORTEX_ST run.stat reproducibility passed : 12692+
WICE_AGRIF_ST run.stat reproducibility passed : 12692+
!----agrif check----!
ORCA2 AGRIF vs ORCA2 NOAGRIF run.stat unchanged - passed : 12692+ 12692+
!----result comparison check----!
check result differences between :
VALID directory : /projects/jmmp/pmathiot/NEMO/NEMO_dev/NEMO/branches/2020/ticket2406_trunk/NEMO_VALIDATION at rev 12692+
and
REFERENCE directory : /projects/jmmp/pmathiot/NEMO/NEMO_dev/NEMO/trunk/NEMO_VALIDATION at rev 12530
WGYRE_PISCES_ST run.stat files are identical
WGYRE_PISCES_ST tracer.stat files are identical
WORCA2_ICE_PISCES_ST run.stat files are identical
WORCA2_OFF_PISCES_ST tracer.stat files are identical
WAMM12_ST run.stat files are identical
WISOMIP_ST run.stat files are identical
WORCA2_SAS_ICE_ST run.stat files are identical
WAGRIF_DEMO_ST run.stat files are identical
WSPITZ12_ST run.stat files are identical
WISOMIP_ST run.stat files are identical
WVORTEX_ST run.stat files are identical
WICE_AGRIF_ST run.stat files are identical
comment:8 Changed 3 years ago by mathiot
In 12694:
comment:9 Changed 3 years ago by mathiot
In 12696:
comment:10 Changed 3 years ago by mathiot
In 12697:
comment:11 Changed 3 years ago by mathiot
In 12698:
comment:12 Changed 3 years ago by mathiot
In 12699:
comment:13 Changed 3 years ago by mathiot
In 12700:
comment:14 Changed 3 years ago by mathiot
- Resolution set to fixed
- Status changed from new to closed
comment:15 Changed 3 years ago by mathiot
In 12702:
comment:16 Changed 3 years ago by mathiot
In 12703:
In 12543: