#2229 closed Defect (fixed)
bug in ICB behavior along coastlines
| Reported by: | mathiot | Owned by: | mathiot |
|---|---|---|---|
| Priority: | low | Milestone: | |
| Component: | TOP | Version: | v4.0 |
| Severity: | minor | Keywords: | ICB v4.0 |
| Cc: |
Description
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Context
In a box configuration with a uniform T/S initialisation (-1.9 and 34.4) without any forcing except, the melt rate is different along the boundary and it should not.
Analysis
The reason is that the masked cell are taking into account for the interpolation of sst at the iceberg location.
This is also the case for many other variables:
- the iceberg along the coastline feel a warmer/colder sst depending of the sign of the local sst.
- the interpolation of the ssh is creating an artificial slope toward the coastline or offshore depending of the sign of the local ssh.
- the atmospheric stress is masked, so value on land is not correct.
- The ice thickness and concentration over land is also used during interpolation.
- For the velocity (ocean and ice), the situation is more complex as 0 at a U/V point along the coastline is a valid data (no slip case). The suggested change will not fix the known issue of slip condition of icebergs. ICB feel 0 velocity at the coast or in land.
Recommendation
Change suggested in icb_utl_bilin_h:
- Add an argument about the use of land value during the interpolation (use it or not in the interpolation)
- Change accordingly the weight computation
A branch will be created for review before committing the fix to the trunk.
It affect the trunk and NEMO_4.0
Commit History (8)
| Changeset | Author | Time | ChangeLog |
|---|---|---|---|
| 11890 | smasson | 2019-11-12T16:17:11+01:00 | |
| 10726 | mathiot | 2019-02-27T16:06:35+01:00 | changes related to bug fixes described in tickets #2228, #2229, #2238 and #1595 in NEMO 4.0 |
| 10692 | mathiot | 2019-02-15T17:44:51+01:00 | delete branch fix_ticket2229 (ticket #2229) |
| 10691 | mathiot | 2019-02-15T17:41:15+01:00 | merge fix_ticket2229 into the trunk (ticket #2229) |
| 10689 | mathiot | 2019-02-15T14:55:37+01:00 | update branch to the head of the trunk r10688 (ticket #2229) |
| 10688 | mathiot | 2019-02-15T14:42:09+01:00 | cosmetic change (ticket #2229) |
| 10678 | mathiot | 2019-02-14T14:10:42+01:00 | mask used in icb_bilin_h should have extra haloe (ticket #2229) |
| 10652 | mathiot | 2019-02-08T11:29:16+01:00 | branch and suggested changes for ticket #2229 (iceberg melt along coastlines) |
Attachments (1)
Change History (12)
Changed 5 years ago by mathiot
comment:1 Changed 5 years ago by mathiot
Illustration of the issue with a GYRE configuration with uniform T/S, calving and no forcing except a uniform precipitation to drive a positive flat ssh => icb melt should be uniform. Simulation length : 5d
comment:2 Changed 5 years ago by mathiot
In 10652:
comment:3 Changed 5 years ago by mathiot
In 10678:
comment:4 Changed 5 years ago by davestorkey
I've reviewed the code changes and I think they are correct.
comment:5 Changed 5 years ago by mathiot
In 10688:
comment:6 Changed 5 years ago by mathiot
In 10689:
comment:7 Changed 5 years ago by mathiot
- Resolution set to fixed
- Status changed from new to closed
In 10691:
comment:8 Changed 5 years ago by mathiot
In 10692:
comment:9 Changed 5 years ago by mathiot
In 10726:
comment:10 Changed 4 years ago by smasson
In 11890:
comment:11 Changed 2 years ago by nemo
- Keywords v4.0 added; removed
Illustration of the issue in GYRE configuration (uniform T/S, no wind, only precip to drive a flat ssh > 0)