Opened 3 years ago

Closed 20 months ago

#2064 closed Defect (wontfix)

ice velocity issues in AGRIF sponge layer with LIM2 VP

Reported by: torgemartin Owned by: clem
Priority: low Milestone:
Component: AGRIF Version: release-3.6
Severity: minor Keywords:
Cc:

Description

Context

We found unusually high (order 101 to 102 greater than expected) sea ice drift velocities near coastal grid cells within the sponge layer of the AGRIF nested model. The false velocities are advected into the nest domain. As a consequence, thick ice formed (convergence downstream of ice flow) and ocean received too much momentum at these grid cells. The high velocities are not found in the base model. We use NEMO 3.6 with LIM2 and VP rheology.

Analysis

Issue with interpolation of ice drift velocity from base model to nest domain. Problem does not occur when using EVP (C-grid), only in case of VP (B-grid).

Recommendation

Problem seems to be solved when applying the following change to agrif_lim2_interp.F90 (note, this is for key_lim2_vp):

In SUBROUTINE agrif_rhg_lim2_load the Agrif_specialValue must be set to -9999. before calling interp_u/v_ice.

67,68c67,72
← Agrif_SpecialValue=0.
← Agrif_UseSpecialValue = .FALSE.
—-
→ ! Agrif_SpecialValue=0.
→ ! Agrif_UseSpecialValue = .FALSE.
→ Agrif_SpecialValue=-9999.
→ Agrif_UseSpecialValue = .TRUE.

B.t.w. this correction compares well to the EVP case.

Commit History (0)

(No commits)

Change History (3)

comment:1 Changed 3 years ago by torgemartin

  • Component changed from OPA to AGRIF

comment:2 Changed 3 years ago by clevy

  • Owner set to clem
  • Status changed from new to assigned

comment:3 Changed 20 months ago by jchanut

  • Resolution set to wontfix
  • Status changed from assigned to closed
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