# Latest **URL:** https://nemo-ocean.discourse.group/latest.md [Latest](https://nemo-ocean.discourse.group/latest.md) · [Categories](https://nemo-ocean.discourse.group/categories.md) · [Tags](https://nemo-ocean.discourse.group/tags.md) --- ## [Structure of open boundaries](https://nemo-ocean.discourse.group/t/structure-of-open-boundaries/72)
**Author:** [@marilianemo](https://nemo-ocean.discourse.group/u/marilianemo)\ **Replies:** 29\ **Last updated:** [21 September 2026 08:57 UTC](https://nemo-ocean.discourse.group/t/structure-of-open-boundaries/72 "2026-09-21T08:57:06Z")
Dear all, I’m trying to run NEMOv4.0\_PISCES-v2 in an offline mode for a regional configuration. I have two open boundaries (W,E) and set then in namelist\_cfg as &nambdy\_index ! structured open boundaries definition … --- ## [\[v5.0.x\] bug in the execution of iom\_init in ORCA2\_ICE\_PISCES and X3\_ORCA2\_ICE\_PISCES](https://nemo-ocean.discourse.group/t/v5-0-x-bug-in-the-execution-of-iom-init-in-orca2-ice-pisces-and-x3-orca2-ice-pisces/1047)
**Author:** [@vsciortino](https://nemo-ocean.discourse.group/u/vsciortino)\ **Replies:** 0\ **Last updated:** [17 September 2026 09:18 UTC](https://nemo-ocean.discourse.group/t/v5-0-x-bug-in-the-execution-of-iom-init-in-orca2-ice-pisces-and-x3-orca2-ice-pisces/1047 "2026-09-17T09:18:36Z")
I compiled ORCA2\_ICE\_PISCES using the Intel OneAPI compilers 2024.1.0 on Leonardo CINECA, and in particular “mpiifx”; I used these flags in the cpp\_ORCA2\_ICE\_PISCES.fcm bld::tool::fppkeys key\_si3 key\_top key\_xios key\_… --- ## [\`DOMAINcfg\` settings \`rn\_e3zps\_min\` and \`rn\_e3zps\_rat\` appear inactive](https://nemo-ocean.discourse.group/t/domaincfg-settings-rn-e3zps-min-and-rn-e3zps-rat-appear-inactive/1045)
**Author:** [@d.stephenson](https://nemo-ocean.discourse.group/u/d.stephenson)\ **Replies:** 0\ **Last updated:** [11 September 2026 10:28 UTC](https://nemo-ocean.discourse.group/t/domaincfg-settings-rn-e3zps-min-and-rn-e3zps-rat-appear-inactive/1045 "2026-09-11T10:28:07Z")
Hello, I’m using a fork of 4.2.2 (here) to set up a “hybrid-resolution” simulation using AGRIF, where an eORCA025 domain is the “child” and the “parent” is coarsened by a factor of 3 (i.e. 0.75 degree), as in described h… --- ## [\[v.4.0.x\] Instability error and "p4zopt.f90" crash issue that occur on the same day](https://nemo-ocean.discourse.group/t/v-4-0-x-instability-error-and-p4zopt-f90-crash-issue-that-occur-on-the-same-day/312)
**Author:** [@Jin](https://nemo-ocean.discourse.group/u/Jin)\ **Replies:** 2\ **Last updated:** [24 August 2026 05:41 UTC](https://nemo-ocean.discourse.group/t/v-4-0-x-instability-error-and-p4zopt-f90-crash-issue-that-occur-on-the-same-day/312 "2026-08-24T05:41:06Z")
Dear all, I have set up ORCA2\_ICE\_PISCES in NEMO v4.0.6 using gfortran compiler. I met two significant errors for running model, which are the instability error and the p4zopt.f90 crash issue. I solved the problem temp… --- ## [\[v4.0.x\] \*p4zopt.f90\* crash: out of lower bound value for \`rkrgb\`](https://nemo-ocean.discourse.group/t/v4-0-x-p4zopt-f90-crash-out-of-lower-bound-value-for-rkrgb/290)
**Author:** [@ukocean](https://nemo-ocean.discourse.group/u/ukocean)\ **Replies:** 3\ **Last updated:** [24 August 2026 05:21 UTC](https://nemo-ocean.discourse.group/t/v4-0-x-p4zopt-f90-crash-out-of-lower-bound-value-for-rkrgb/290 "2026-08-24T05:21:51Z")
Dear users, I’m trying to run r4.0.7 version of nemo using r05 resolution and get the error message: forrtl: severe (408): fort: (3): Subscript #2 of the array RKRGB has value "-2147483648" which is less than the lower… --- ## [Heat fluxes in NEMO and LIM 2](https://nemo-ocean.discourse.group/t/heat-fluxes-in-nemo-and-lim-2/1043)
**Author:** [@danaking](https://nemo-ocean.discourse.group/u/danaking)\ **Replies:** 0\ **Last updated:** [17 August 2026 15:12 UTC](https://nemo-ocean.discourse.group/t/heat-fluxes-in-nemo-and-lim-2/1043 "2026-08-17T15:12:05Z")
Hello, I am very new to working with a reanalysis model and still trying to understand how everything is connected. I am using the GLORYS model on the ORCA grid, which uses the NEMO ocean model (something between versio… --- ## [Output problem with NEMO-PISCES 4.2.3 + XIOS 2.5 users tracer](https://nemo-ocean.discourse.group/t/output-problem-with-nemo-pisces-4-2-3-xios-2-5-users-tracer/1042)
**Author:** [@Pysh](https://nemo-ocean.discourse.group/u/Pysh)\ **Replies:** 0\ **Last updated:** [8 August 2026 11:41 UTC](https://nemo-ocean.discourse.group/t/output-problem-with-nemo-pisces-4-2-3-xios-2-5-users-tracer/1042 "2026-08-08T11:41:55Z")
Hello! I’m having trouble solving this problem. Nemo 4.2.3 + XIOS 2.5. ORCA2-PISCES configuration. I’m trying to run a task for user passive tracer with source data from an external file. When outputting the tracer conc… --- ## [Running AGRIF with tides (Nemo 4.2.2)](https://nemo-ocean.discourse.group/t/running-agrif-with-tides-nemo-4-2-2/1041)
**Author:** [@robinson](https://nemo-ocean.discourse.group/u/robinson)\ **Replies:** 2\ **Last updated:** [6 August 2026 12:31 UTC](https://nemo-ocean.discourse.group/t/running-agrif-with-tides-nemo-4-2-2/1041 "2026-08-06T12:31:57Z")
Dear all, My AGRIF nest crashes, not immediately, but after a while, whatever I do if I run with tides. Using Nemo 4.2.2 The crash occurs in the barotropic mode, and generates NaNs quickly all over the place. Based on… --- ## [2D and 3D bounday condition](https://nemo-ocean.discourse.group/t/2d-and-3d-bounday-condition/1037)
**Author:** [@sennevilles](https://nemo-ocean.discourse.group/u/sennevilles)\ **Replies:** 6\ **Last updated:** [28 July 2026 18:49 UTC](https://nemo-ocean.discourse.group/t/2d-and-3d-bounday-condition/1037 "2026-07-28T18:49:16Z")
Hi, I computed open boundary conditions for my child domain (using VVL) from a parent model (also using VVL). I ran a first simulation (simulation 1) using ln\_full\_vel = .true. and providing bn\_u3d and bn\_v3d. Then, fo… --- ## [Compatibility between the ORCA2\_OFF\_v5.0.0.tar.gz input files and the namelist\_cfg for the ORCA2\_OFF\_TRC reference case](https://nemo-ocean.discourse.group/t/compatibility-between-the-orca2-off-v5-0-0-tar-gz-input-files-and-the-namelist-cfg-for-the-orca2-off-trc-reference-case/1012)
**Author:** [@baptiste](https://nemo-ocean.discourse.group/u/baptiste)\ **Replies:** 1\ **Last updated:** [16 July 2026 13:59 UTC](https://nemo-ocean.discourse.group/t/compatibility-between-the-orca2-off-v5-0-0-tar-gz-input-files-and-the-namelist-cfg-for-the-orca2-off-trc-reference-case/1012 "2026-07-16T13:59:53Z")
I downloaded ORCA2\_OFF\_v5.0.0.tar.gz from NEMO SETTE input files delivered through Jasmin . Then, when I use these files for the reference configuration ORCA2\_OFF\_TRC, ./nemo crash with these E R R O R s: iom\_varid, fil… --- ## [The vertical diffusion trend term has issues (utrd\_zdf/vtrd\_zdf)](https://nemo-ocean.discourse.group/t/the-vertical-diffusion-trend-term-has-issues-utrd-zdf-vtrd-zdf/1036)
**Author:** [@corentingnt](https://nemo-ocean.discourse.group/u/corentingnt)\ **Replies:** 1\ **Last updated:** [2 July 2026 16:50 UTC](https://nemo-ocean.discourse.group/t/the-vertical-diffusion-trend-term-has-issues-utrd-zdf-vtrd-zdf/1036 "2026-07-02T16:50:44Z")
Hi, We do this message with Véga, trainee with Julie Deshayes and myself at Locean (I am PhD student). We looked at different trends terms in the NEMO.4.0 version. We noticed an issue with utrd\_zdf and vtrd\_zdf, that se… --- ## [SI³: EAP rheology broken? Segmentation fault with ln\_rhg\_EAP = .TRUE](https://nemo-ocean.discourse.group/t/si-eap-rheology-broken-segmentation-fault-with-ln-rhg-eap-true/1035)
**Author:** [@jraylmer](https://nemo-ocean.discourse.group/u/jraylmer)\ **Replies:** 0\ **Last updated:** [24 June 2026 09:56 UTC](https://nemo-ocean.discourse.group/t/si-eap-rheology-broken-segmentation-fault-with-ln-rhg-eap-true/1035 "2026-06-24T09:56:14Z")
There seems to be a technical issue with the EAP rheology scheme. When activating this scheme in a basic reference configuration with no code modifications, I am getting a segmentation fault when activating this scheme. … --- ## [ORCA12 grid -\> help to find](https://nemo-ocean.discourse.group/t/orca12-grid-help-to-find/1032)
**Author:** [@izanovicki](https://nemo-ocean.discourse.group/u/izanovicki)\ **Replies:** 0\ **Last updated:** [20 June 2026 08:38 UTC](https://nemo-ocean.discourse.group/t/orca12-grid-help-to-find/1032 "2026-06-20T08:38:20Z")
I’m looking for the ORCA12 domain\_cfg.nc (or coordinates.nc/mesh\_mask.nc) corresponding to the Mercator GLORYS12 reanalysis (NEMO 3.1 ORCA12 50 levels). The former CEDA repository seems unavailable. Is there any mirror o… --- ## [How to get XIOS2 and XIOS3 Library](https://nemo-ocean.discourse.group/t/how-to-get-xios2-and-xios3-library/1029)
**Author:** [@subrat](https://nemo-ocean.discourse.group/u/subrat)\ **Replies:** 4\ **Last updated:** [18 June 2026 17:45 UTC](https://nemo-ocean.discourse.group/t/how-to-get-xios2-and-xios3-library/1029 "2026-06-18T17:45:31Z")
Hi everyone, I am working on a project, an ocean analysis system, for which I need to build NEMO5. On the NEMO official site, it states that XIOS2 and XIOS3 can be downloaded via Subversion (SVN), but SVN no longer exi… --- ## [NEMO 5.0 - XIOS 3 hangs at initialization](https://nemo-ocean.discourse.group/t/nemo-5-0-xios-3-hangs-at-initialization/858)
**Author:** [@Luc](https://nemo-ocean.discourse.group/u/Luc)\ **Replies:** 3\ **Last updated:** [17 June 2026 11:08 UTC](https://nemo-ocean.discourse.group/t/nemo-5-0-xios-3-hangs-at-initialization/858 "2026-06-17T11:08:35Z")
Hello, When I run my NEMO 5.0 config with XIOS 2, it runs fine. I’m trying to switch to XIOS 3. My main motivation is to have less writers, as the cluster admins always complain I have too many disk access. I copied t… --- ## [Inexplicable XIOS troubles](https://nemo-ocean.discourse.group/t/inexplicable-xios-troubles/1028)
**Author:** [@francesco.tuccia](https://nemo-ocean.discourse.group/u/francesco.tuccia)\ **Replies:** 1\ **Last updated:** [16 June 2026 09:06 UTC](https://nemo-ocean.discourse.group/t/inexplicable-xios-troubles/1028 "2026-06-16T09:06:46Z")
Good afternoon to all, This is a more of a long shot than a real help request, and I am sorry if this post does not respect the formats of this community, but me and a colleague are experiencing troubles with XIOS sinc… --- ## [Question about the wind-stress module calculation in sbcflx.F90](https://nemo-ocean.discourse.group/t/question-about-the-wind-stress-module-calculation-in-sbcflx-f90/1027)
**Author:** [@qtqw](https://nemo-ocean.discourse.group/u/qtqw)\ **Replies:** 1\ **Last updated:** [15 June 2026 07:23 UTC](https://nemo-ocean.discourse.group/t/question-about-the-wind-stress-module-calculation-in-sbcflx-f90/1027 "2026-06-15T07:23:55Z")
In my version of NEMO 4.6 I noticed the following line in NEMOGCM/src/OCE/SBC/sbcflx.F90: zmod = 0.5\_wp \* SQRT( ztx \* ztx + zty \* zty ) \* tmask(ji,jj,1) where ztx and zty are the zonal and meridional wind-stress compon… --- ## [Geoscientific Model Development (GMD): Seeking Oceanogrpahy Topical Editors](https://nemo-ocean.discourse.group/t/geoscientific-model-development-gmd-seeking-oceanogrpahy-topical-editors/1025)
**Author:** [@swrneale](https://nemo-ocean.discourse.group/u/swrneale)\ **Replies:** 0\ **Last updated:** [4 June 2026 12:54 UTC](https://nemo-ocean.discourse.group/t/geoscientific-model-development-gmd-seeking-oceanogrpahy-topical-editors/1025 "2026-06-04T12:54:22Z")
Dear NEMO scientists I’m reaching out here because the EGU Journal Geoscientific Model Development (GMD) is currently looking for Topical Editors (TEs) to handle our ever increasing volume of article submissions. Key t… --- ## [Turning on ln\_cfc11, cfc12 and sf6](https://nemo-ocean.discourse.group/t/turning-on-ln-cfc11-cfc12-and-sf6/1023)
**Author:** [@ErikBuitenhuis](https://nemo-ocean.discourse.group/u/ErikBuitenhuis)\ **Replies:** 0\ **Last updated:** [2 June 2026 13:12 UTC](https://nemo-ocean.discourse.group/t/turning-on-ln-cfc11-cfc12-and-sf6/1023 "2026-06-02T13:12:24Z")
I’m trying to turn on ln\_cfc11, ln\_cfc12 and ln\_sf6 in NEMO\_v5.0. Does anyone have an atmospheric forcing file in the format it expects, and matching namelist\_trc\_ref and/or namelist\_trc\_cfg? Thanks, Erik e031@uea.ac.… --- ## [Diamlr output for AGRIF configurations](https://nemo-ocean.discourse.group/t/diamlr-output-for-agrif-configurations/1015)
**Author:** [@lmock](https://nemo-ocean.discourse.group/u/lmock)\ **Replies:** 1\ **Last updated:** [20 May 2026 13:42 UTC](https://nemo-ocean.discourse.group/t/diamlr-output-for-agrif-configurations/1015 "2026-05-20T13:42:21Z")
Hi! We’re running AGRIF-configurations with tidal constituents and want to write the analysis output diamlr. For an eORCA025 configuration this worked (like in the AMM12 example), but we can’t make it work for the AGRI… --- ## [AGRIF doesn't compile with gcc15 due to conflicting types](https://nemo-ocean.discourse.group/t/agrif-doesnt-compile-with-gcc15-due-to-conflicting-types/1022)
**Author:** [@Franziska](https://nemo-ocean.discourse.group/u/Franziska)\ **Replies:** 4\ **Last updated:** [12 May 2026 09:21 UTC](https://nemo-ocean.discourse.group/t/agrif-doesnt-compile-with-gcc15-due-to-conflicting-types/1022 "2026-05-12T09:21:27Z")
Hi, when compiling an AGRIF configuration (e.g. AGRIF\_DEMO) using GCC 15 (which appears to be more restrict than previous versions) it fails with the following error message: .../nemo/ext/AGRIF/LIB/UtilFortran.c:266:6:… --- ## [Bug on gridcells with only 1 vertical layer](https://nemo-ocean.discourse.group/t/bug-on-gridcells-with-only-1-vertical-layer/1019)
**Author:** [@SimonSD](https://nemo-ocean.discourse.group/u/SimonSD)\ **Replies:** 0\ **Last updated:** [7 May 2026 20:14 UTC](https://nemo-ocean.discourse.group/t/bug-on-gridcells-with-only-1-vertical-layer/1019 "2026-05-07T20:14:03Z")
When I use the same bathymetric grid as I was using with NEMO 3.6, but with NEMO 4.2.2, the model aborts after a certain number of timesteps because SSH \>= 20m at one gridpoint. It appears that this gridpoint has just on… --- ## [GLS bug in -b main (Missing Validation / Incomplete Input Checking)](https://nemo-ocean.discourse.group/t/gls-bug-in-b-main-missing-validation-incomplete-input-checking/1006)
**Author:** [@GODZILLA](https://nemo-ocean.discourse.group/u/GODZILLA)\ **Replies:** 1\ **Last updated:** [4 May 2026 18:42 UTC](https://nemo-ocean.discourse.group/t/gls-bug-in-b-main-missing-validation-incomplete-input-checking/1006 "2026-05-04T18:42:46Z")
Dear all, I working before on FVCOM/ADCIRC model. currently i have some planning to run NEMO model for Project work (NEMO+some BGC). Before starting the simulation i compile and run (small test with a few little steps).… --- ## [NEMO SSL certificate has expired 15/07/2025](https://nemo-ocean.discourse.group/t/nemo-ssl-certificate-has-expired-15-07-2025/929)
**Author:** [@richardhill](https://nemo-ocean.discourse.group/u/richardhill)\ **Replies:** 4\ **Last updated:** [1 May 2026 14:45 UTC](https://nemo-ocean.discourse.group/t/nemo-ssl-certificate-has-expired-15-07-2025/929 "2026-05-01T14:45:08Z")
The NEMO SSL certificate has expired today, causing errors when trying to access the NEMO git repository: 13:fetch remote: “fatal: unable to access ‘https://forge.nemo-ocean.eu/nemo/nemo.git/’: SSL certificate problem: … --- ## [Help to find grids ORCA025 and ORCA12](https://nemo-ocean.discourse.group/t/help-to-find-grids-orca025-and-orca12/536)
**Author:** [@elsy](https://nemo-ocean.discourse.group/u/elsy)\ **Replies:** 8\ **Last updated:** [17 April 2026 12:40 UTC](https://nemo-ocean.discourse.group/t/help-to-find-grids-orca025-and-orca12/536 "2026-04-17T12:40:37Z")
Dear all, I tried to download the ORCA025 and ORCA12 grids, but I couldn’t find them anywhere online. Could you please help me by telling me where I can find these files to download or whom I can ask for them? Thank you… --- ## [North fold bug? Artefact along north fold in sea ice variables](https://nemo-ocean.discourse.group/t/north-fold-bug-artefact-along-north-fold-in-sea-ice-variables/972)
**Author:** [@jraylmer](https://nemo-ocean.discourse.group/u/jraylmer)\ **Replies:** 15\ **Last updated:** [17 April 2026 10:12 UTC](https://nemo-ocean.discourse.group/t/north-fold-bug-artefact-along-north-fold-in-sea-ice-variables/972 "2026-04-17T10:12:01Z")
I run ORCA2-ICE simulations and often see artefacts in output variables along the grid cells where north-folding occurs. It sometimes takes several years before it appears, depending on the forcing and namelist settings.… --- ## [PISCES training session 2026](https://nemo-ocean.discourse.group/t/pisces-training-session-2026/1009)
**Author:** [@rlod](https://nemo-ocean.discourse.group/u/rlod)\ **Replies:** 2\ **Last updated:** [7 April 2026 09:52 UTC](https://nemo-ocean.discourse.group/t/pisces-training-session-2026/1009 "2026-04-07T09:52:19Z")
Dear all, Registration for the next PISCES training session is now open until 29 May 2026 This session is open primarily to beginners, but also to experienced users. Objectives : The objective of this practical sessi… --- ## [Link to SETTE inputs site broken](https://nemo-ocean.discourse.group/t/link-to-sette-inputs-site-broken/1007)
**Author:** [@ptownsend](https://nemo-ocean.discourse.group/u/ptownsend)\ **Replies:** 2\ **Last updated:** [24 March 2026 16:18 UTC](https://nemo-ocean.discourse.group/t/link-to-sette-inputs-site-broken/1007 "2026-03-24T16:18:24Z")
Hello. I am looking to create a 1D version of my model in NEMO 5.0 and would like to use the C1D PAPA reference configuration as a starting point for testing. However, the SETTE inputs site (linked here) with the necess… --- ## [Best practices for NetCDF forcing files to avoid continuous disk reads (chunking / unlimited time / compression)?](https://nemo-ocean.discourse.group/t/best-practices-for-netcdf-forcing-files-to-avoid-continuous-disk-reads-chunking-unlimited-time-compression/997)
**Author:** [@mchoblet](https://nemo-ocean.discourse.group/u/mchoblet)\ **Replies:** 8\ **Last updated:** [24 March 2026 13:33 UTC](https://nemo-ocean.discourse.group/t/best-practices-for-netcdf-forcing-files-to-avoid-continuous-disk-reads-chunking-unlimited-time-compression/997 "2026-03-24T13:33:47Z")
Hello, I’m looking for advice / best practices on NetCDF formatting of NEMO input forcing files to reduce unnecessary I/O on I/O-limited, shared HPC systems (parallel filesystem, multiple users running at once). Contex… --- ## [Running AGRIF+TOP+Biogeochemistry](https://nemo-ocean.discourse.group/t/running-agrif-top-biogeochemistry/1004)
**Author:** [@robinson](https://nemo-ocean.discourse.group/u/robinson)\ **Replies:** 1\ **Last updated:** [23 March 2026 08:54 UTC](https://nemo-ocean.discourse.group/t/running-agrif-top-biogeochemistry/1004 "2026-03-23T08:54:14Z")
Dear all, It’s all in the title. Is it possible to run Agrif with TOP, and a biogeochemical model ? Takk for hjelp, Robinson [Next page](https://nemo-ocean.discourse.group/latest.md?page=1)