Skip to content

Fix interior OBC indexing bug in tracer advection #1013

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
Hallberg-NOAA merged 2 commits into from
Jan 12, 2026
Merged

Fix interior OBC indexing bug in tracer advection #1013

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
7bdd8e1
Refactor nsten_halo in routine advect_tracer
herrwang0 Jan 5, 2026
8849012
Fix OBC indexing bug in MOM_tracer_advect
herrwang0 Jan 5, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
32 changes: 15 additions & 17 deletions src/tracer/MOM_tracer_advect.F90
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -223,15 +223,15 @@ subroutine advect_tracer(h_end, uhtr, vhtr, OBC, dt, G, GV, US, CS, Reg, x_first
!$OMP end parallel

isv = is ; iev = ie ; jsv = js ; jev = je
nsten_halo = min(is - isd, ied - ie, js - jsd, jed - je) / stencil

do itt=1,max_iter

if (isv > is-stencil) then
call do_group_pass(CS%pass_uhr_vhr_t_hprev, G%Domain, clock=id_clock_pass)

nsten_halo = min(is-isd,ied-ie,js-jsd,jed-je)/stencil
isv = is-nsten_halo*stencil ; jsv = js-nsten_halo*stencil
iev = ie+nsten_halo*stencil ; jev = je+nsten_halo*stencil
isv = is - nsten_halo * stencil ; jsv = js - nsten_halo * stencil
iev = ie + nsten_halo * stencil ; jev = je + nsten_halo * stencil
! Reevaluate domore_u & domore_v unless the valid range is the same size as
! before. Also, do this if there is Strang splitting.
if ((nsten_halo > 1) .or. (itt==1)) then
Expand Down Expand Up @@ -680,13 +680,12 @@ subroutine advect_x(Tr, hprev, uhr, uh_neglect, OBC, domore_u, ntr, Idt, &

! Update do_i so that nothing changes outside of the OBC (problem for interior OBCs only)
if (associated(OBC)) then
if ((.not.OBC%exterior_OBC_bug) .and. (OBC%OBC_pe)) then
if (OBC%specified_u_BCs_exist_globally .or. OBC%open_u_BCs_exist_globally) then
do i=is,ie-1
if (OBC%segnum_u(I,j) > 0) do_i(i+1,j) = .false. ! OBC_DIRECTION_E
if (OBC%segnum_u(I,j) < 0) do_i(i,j) = .false. ! OBC_DIRECTION_W
enddo
endif
if ((.not.OBC%exterior_OBC_bug) .and. (OBC%OBC_pe) .and. &
(OBC%specified_u_BCs_exist_globally .or. OBC%open_u_BCs_exist_globally)) then
! OBC_DIRECTION_E / OBC_DIRECTION_W on the west / east edge
do i=is,ie ; if ((OBC%segnum_u(I-1,j) > 0) .or. (OBC%segnum_u(I,j) < 0)) &
do_i(i,j) = .false.
enddo
endif
endif

Expand Down Expand Up @@ -1093,13 +1092,12 @@ subroutine advect_y(Tr, hprev, vhr, vh_neglect, OBC, domore_v, ntr, Idt, &

! Update do_i so that nothing changes outside of the OBC (problem for interior OBCs only)
if (associated(OBC)) then
if ((OBC%exterior_OBC_bug .eqv. .false.) .and. (OBC%OBC_pe)) then
if (OBC%specified_v_BCs_exist_globally .or. OBC%open_v_BCs_exist_globally) then
do i=is,ie
if (OBC%segnum_v(i,J-1) > 0) do_i(i,j) = .false. ! OBC_DIRECTION_N
if (OBC%segnum_v(i,J) < 0) do_i(i,j) = .false. ! OBC_DIRECTION_S
enddo
endif
if ((.not.OBC%exterior_OBC_bug) .and. (OBC%OBC_pe) .and. &
(OBC%specified_v_BCs_exist_globally .or. OBC%open_v_BCs_exist_globally)) then
! OBC_DIRECTION_N / OBC_DIRECTION_S on the south / north edge
do i=is,ie ; if ((OBC%segnum_v(i,J-1) > 0) .or. (OBC%segnum_v(i,J) < 0)) &
do_i(i,j) = .false.
enddo
endif
endif

Expand Down