Opened 8 weeks ago

Closed 6 weeks ago

#2578 closed Defect (fixed)

Melt ponds defects

Reported by: vancop Owned by: systeam
Priority: low Milestone:
Component: SI3 Version:
Severity: minor Keywords:
Cc: Branch review: failed
MP ready?: no Task progress: Unspecified

Description

Melt ponds on sea ice are new in the system and suffer from a series of defects. Here is my take after spending a few days on them.

Analysis

1) Level-ice ponds are quickly lost in my own tests. Drainage term (taken from topographic framework) is to blame, once removed the problem disappears

One speculation to explain that is that drainage from topo framework is not fit to level ice framework. Indeed Hunke et al 2012 propose to multiply drainage by 0.001 in level-ice framework.

2) The current level-ice implementation is a hybrid between a very simple (CESM) and a simple (level-ice) scheme.

3) The freshwater diagnostics are misleading as no fw is exchanged between ponds and ocean. The drainage contribution is missing

Recommendations

1) Test the level code with reduced drainage

2) Re-implement the CESM scheme as an extra (extensively tested in LLN)

3) Remove fw diagnostic wfx_pnd, it does not tell much about what happens in the code and is misleading as one would think that melt ponds actually contribute to fw budget whereas they do not.

4) Propose an implementation of an explicit fw contribution of melt ponds for the work plan (should be relatively easy)

Commit History (1)

ChangesetAuthorTimeChangeLog
14026clem2020-12-03T09:48:10+01:00

4.0-HEAD: fix bugs and defects related to tickets #2573 #2575 #2576 #2578. Sette passed and those fixes are now in the trunk, so unless there is a tricky trick somewhere, everything should be fine.

Change History (2)

comment:1 Changed 6 weeks ago by clem

In 14026:

4.0-HEAD: fix bugs and defects related to tickets #2573 #2575 #2576 #2578. Sette passed and those fixes are now in the trunk, so unless there is a tricky trick somewhere, everything should be fine.

comment:2 Changed 6 weeks ago by clem

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

also in the trunk at r14005

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