# Unified Model **URL:** https://forum.access-hive.org.au/c/atmosphere/unified-model-um/20.md [Latest](https://forum.access-hive.org.au/latest.md) · [Categories](https://forum.access-hive.org.au/categories.md) · [Tags](https://forum.access-hive.org.au/tags.md) --- ## [About the Unified Model category](https://forum.access-hive.org.au/t/about-the-unified-model-category/42)
**Author:** [@rbeucher](https://forum.access-hive.org.au/u/rbeucher)\ **Replies:** 0\ **Last updated:** [18 October 2022 06:20 UTC](https://forum.access-hive.org.au/t/about-the-unified-model-category/42 "2022-10-18T06:20:19Z")
The Unified Model (UM) is a numerical model of the atmosphere used in ACCESS models for both weather and climate applications. This sub-category is for UM-related discussions and questions, making it easier to discover … --- ## [IOS Client memory cap exceeded - UM forecast fails](https://forum.access-hive.org.au/t/ios-client-memory-cap-exceeded-um-forecast-fails/6819)
**Author:** [@Paul.Gregory](https://forum.access-hive.org.au/u/Paul.Gregory)\ **Replies:** 3\ **Last updated:** [20 August 2026 05:53 UTC](https://forum.access-hive.org.au/t/ios-client-memory-cap-exceeded-um-forecast-fails/6819 "2026-08-20T05:53:24Z")
So I’m running the Centre’s rAM3 experiment (u-by395/ram3\_flagship) and I’ve been asked to add some extra STASH outputs for another experiment. The UM now fails with ???????????????????????????????????????????????????… --- ## [Updating UM source to handle very large high-resolution domains (\> 4096 rows)](https://forum.access-hive.org.au/t/updating-um-source-to-handle-very-large-high-resolution-domains-4096-rows/6801)
**Author:** [@Paul.Gregory](https://forum.access-hive.org.au/u/Paul.Gregory)\ **Replies:** 9\ **Last updated:** [14 August 2026 12:08 UTC](https://forum.access-hive.org.au/t/updating-um-source-to-handle-very-large-high-resolution-domains-4096-rows/6801 "2026-08-14T12:08:12Z")
Hi all. @bethanwhite attempted to run a very large 1 km domain and hit the following hard-coded limits: ??????????????????????????????????????????????????????????????????????????????? ???!!!???!!!???!!!???!!!???!!! … --- ## [Output STASH fields for reconfiguration change depending on Intel compiler version used to build UMv13.5](https://forum.access-hive.org.au/t/output-stash-fields-for-reconfiguration-change-depending-on-intel-compiler-version-used-to-build-umv13-5/5390)
**Author:** [@Paul.Gregory](https://forum.access-hive.org.au/u/Paul.Gregory)\ **Replies:** 3\ **Last updated:** [12 August 2026 23:23 UTC](https://forum.access-hive.org.au/t/output-stash-fields-for-reconfiguration-change-depending-on-intel-compiler-version-used-to-build-umv13-5/5390 "2026-08-12T23:23:54Z")
Hello all. TLDR; I spent a long time chasing down a fault in the ACCESS-rAM3 EC grib reconfiguration task which is caused by changing the Intel compiler version used to build UMv13.5 Background : The CoE 21stCenturyWea… --- ## [Iris cube attribute 'grid\_staggering' an issue with soil ancillary generation](https://forum.access-hive.org.au/t/iris-cube-attribute-grid-staggering-an-issue-with-soil-ancillary-generation/6421)
**Author:** [@Paul.Gregory](https://forum.access-hive.org.au/u/Paul.Gregory)\ **Replies:** 2\ **Last updated:** [21 May 2026 04:19 UTC](https://forum.access-hive.org.au/t/iris-cube-attribute-grid-staggering-an-issue-with-soil-ancillary-generation/6421 "2026-05-21T04:19:26Z")
Hi all. TLDR; Does anyone know what the iris cube attribute grid\_staggering (which appears to have integer values) refers to? I came across an error related to this attribute which caused some dramas. I thought I’d sha… --- ## [Rules of thumb for rimwidth and halo for LBCs?](https://forum.access-hive.org.au/t/rules-of-thumb-for-rimwidth-and-halo-for-lbcs/6367)
**Author:** [@ashjbarnes](https://forum.access-hive.org.au/u/ashjbarnes)\ **Replies:** 11\ **Last updated:** [4 May 2026 07:15 UTC](https://forum.access-hive.org.au/t/rules-of-thumb-for-rimwidth-and-halo-for-lbcs/6367 "2026-05-04T07:15:12Z")
Just wondering if rim widths and halo regions are something that should be fiddled with as resolution changes, and if so, if there are any rules of thumb? For context: @Paul.Gregory and I have started off with a very sm… --- ## [Air-sea flux parameterisation (aka bulk formula) in CM3](https://forum.access-hive.org.au/t/air-sea-flux-parameterisation-aka-bulk-formula-in-cm3/5890)
**Author:** [@mmr0](https://forum.access-hive.org.au/u/mmr0)\ **Replies:** 2\ **Last updated:** [11 February 2026 02:14 UTC](https://forum.access-hive.org.au/t/air-sea-flux-parameterisation-aka-bulk-formula-in-cm3/5890 "2026-02-11T02:14:37Z")
Hi, I’d like to understand how air-sea fluxes are computed in CM3 - specifically what flux parameterisation is used and which component does the calculation. I know that in OM3 (with a data atmosphere) these fluxes are… --- ## [Specified output area in the STASH of UM RNS](https://forum.access-hive.org.au/t/specified-output-area-in-the-stash-of-um-rns/5448)
**Author:** [@ZhangchengPei](https://forum.access-hive.org.au/u/ZhangchengPei)\ **Replies:** 4\ **Last updated:** [4 November 2025 02:57 UTC](https://forum.access-hive.org.au/t/specified-output-area-in-the-stash-of-um-rns/5448 "2025-11-04T02:57:29Z")
Hello Atmos community, I was attempting to extract a particular region from a rotated grid. In the STASH request’s domain settings, I chose the “specified area in whole degrees” option and inputted the range I needed: -… --- ## [Building the UM to run on Gadi's Sapphire nodes](https://forum.access-hive.org.au/t/building-the-um-to-run-on-gadis-sapphire-nodes/4698)
**Author:** [@Paul.Gregory](https://forum.access-hive.org.au/u/Paul.Gregory)\ **Replies:** 4\ **Last updated:** [25 July 2025 07:01 UTC](https://forum.access-hive.org.au/t/building-the-um-to-run-on-gadis-sapphire-nodes/4698 "2025-07-25T07:01:20Z")
Hello all. There have been some mentions about building CMIP7 ESM to run on Gadi’s sapphire nodes, e.g. CSIRO - ACCESS-NRI standup minutes - #20 by clairecarouge Has anyone successfully achieved it? I ran the pre-buil… --- ## [Location of ACCESS land masks for ACCESS-AM2 sea-ice/SST ancillary creation](https://forum.access-hive.org.au/t/location-of-access-land-masks-for-access-am2-sea-ice-sst-ancillary-creation/4695)
**Author:** [@alanah.chapman](https://forum.access-hive.org.au/u/alanah.chapman)\ **Replies:** 4\ **Last updated:** [18 July 2025 02:23 UTC](https://forum.access-hive.org.au/t/location-of-access-land-masks-for-access-am2-sea-ice-sst-ancillary-creation/4695 "2025-07-18T02:23:39Z")
Hi everyone, I’m creating some updated sea-ice and SST ancillary datasets for some ACCESS-AM2 model experiments I’m doing, based off of methods and code described by the UK MetOffice here. I have been able to create the… --- ## [Calculating omega on model levels](https://forum.access-hive.org.au/t/calculating-omega-on-model-levels/4689)
**Author:** [@chloemackallah](https://forum.access-hive.org.au/u/chloemackallah)\ **Replies:** 1\ **Last updated:** [11 July 2025 05:36 UTC](https://forum.access-hive.org.au/t/calculating-omega-on-model-levels/4689 "2025-07-11T05:36:24Z")
Hi all, I recently received a query about CM2 vertical coordinates: “”" I’m a PhD student at TU Dresden, Germany. Currently, I’m investigating vertical velocity (omega; Pa/s) in an ensemble of CMIP6 models on different… --- ## [AM: inancila\_rcf\_inancila: Insufficient space for LOOKUP headers](https://forum.access-hive.org.au/t/am-inancila-rcf-inancila-insufficient-space-for-lookup-headers/4656)
**Author:** [@lishx](https://forum.access-hive.org.au/u/lishx)\ **Replies:** 15\ **Last updated:** [11 July 2025 02:57 UTC](https://forum.access-hive.org.au/t/am-inancila-rcf-inancila-insufficient-space-for-lookup-headers/4656 "2025-07-11T02:57:42Z")
OPEN: File /home/565/sl5165/cylc-run/ACCESS-AM3-N512/share/data/etc/ancil/qrclim.rivstor to be Opened on Unit 13 Exists IO: Open: /home/565/sl5165/cylc-run/ACCESS-AM3-N512/share/data/etc/ancil/qrclim.rivstor on unit 13 … --- ## [Issues with configuring the UM I/O server](https://forum.access-hive.org.au/t/issues-with-configuring-the-um-i-o-server/4653)
**Author:** [@Paul.Gregory](https://forum.access-hive.org.au/u/Paul.Gregory)\ **Replies:** 6\ **Last updated:** [1 July 2025 22:30 UTC](https://forum.access-hive.org.au/t/issues-with-configuring-the-um-i-o-server/4653 "2025-07-01T22:30:27Z")
Hello. Myself and @qinggangg have been unable to scale the rAM3 suite beyond about 50x50 processors. The UM will integrate in time successfully. E.g. on 72x70 processors it will compute a 6 hour forecast on the 1 km do… --- ## [How should ACCESS-NRI deploy Mule?](https://forum.access-hive.org.au/t/how-should-access-nri-deploy-mule/4592)
**Author:** [@paulleopardi](https://forum.access-hive.org.au/u/paulleopardi)\ **Replies:** 0\ **Last updated:** [6 June 2025 13:30 UTC](https://forum.access-hive.org.au/t/how-should-access-nri-deploy-mule/4592 "2025-06-06T13:30:23Z")
See previous discussion in UM partnership Mule repository and working practices Issues when transitioning from hh5 to xp65 in suite runs ACCESS-NRI Analysis3 Conda Environments – New Release Announcement Request to add… --- ## [MOSRS authentication : ERROR checking password](https://forum.access-hive.org.au/t/mosrs-authentication-error-checking-password/3665)
**Author:** [@Paul.Gregory](https://forum.access-hive.org.au/u/Paul.Gregory)\ **Replies:** 8\ **Last updated:** [21 March 2025 03:49 UTC](https://forum.access-hive.org.au/t/mosrs-authentication-error-checking-password/3665 "2025-03-21T03:49:03Z")
Hi all. My MOSRS account is now re-activated and I’m getting set up on gadi for the first time (previously I used MOSRS on raijin). I’ve added the following to ~/.subversion/servers \[groups\] metofficesharedrepos = cod… --- ## [UM - Minimum working example?](https://forum.access-hive.org.au/t/um-minimum-working-example/3749)
**Author:** [@Paul.Gregory](https://forum.access-hive.org.au/u/Paul.Gregory)\ **Replies:** 34\ **Last updated:** [6 March 2025 02:57 UTC](https://forum.access-hive.org.au/t/um-minimum-working-example/3749 "2025-03-06T02:57:06Z")
Hi all. While looking over the CLEX and NRI tutorials for AUS2200. I’m wondering if 21stCW would be well served by creating a very small UM test-suite (i.e. a minimum working example). The UKMO UM tutorial here : ht… --- ## [RAL3 documentation paper](https://forum.access-hive.org.au/t/ral3-documentation-paper/3960)
**Author:** [@cnf](https://forum.access-hive.org.au/u/cnf)\ **Replies:** 0\ **Last updated:** [4 December 2024 02:38 UTC](https://forum.access-hive.org.au/t/ral3-documentation-paper/3960 "2024-12-04T02:38:42Z")
The RAL3 documentation paper is now available at GMDD - The third Met Office Unified Model-JULES Regional Atmosphere and Land Configuration, RAL3 This is the configuration used in AUS2200 and the current regional nestin… --- ## [UM RAL3.2 released](https://forum.access-hive.org.au/t/um-ral3-2-released/1401)
**Author:** [@Scott](https://forum.access-hive.org.au/u/Scott)\ **Replies:** 0\ **Last updated:** [17 September 2023 23:22 UTC](https://forum.access-hive.org.au/t/um-ral3-2-released/1401 "2023-09-17T23:22:25Z")
The Met Office have released version 3.2 of the Regional Atmosphere and Land (RAL) configuration, fixing anomalous surface hot spots. RAL3.2 is now available in the RNS, ENS and RCS RMED suites. RNS is available for use… --- ## [Cloud microphysics scheme (CASIM) lecture](https://forum.access-hive.org.au/t/cloud-microphysics-scheme-casim-lecture/2050)
**Author:** [@cnf](https://forum.access-hive.org.au/u/cnf)\ **Replies:** 0\ **Last updated:** [19 April 2024 00:23 UTC](https://forum.access-hive.org.au/t/cloud-microphysics-scheme-casim-lecture/2050 "2024-04-19T00:23:36Z")
Hi all, if you’d like to learn more about the cloud microphysics scheme CASIM used in the RAL3.2 configuration, which is used by AUS2200, take a look at Paul Field’s lecture https://www.youtube.com/watch?v=cE1P7iq3W-Y --- ## [Cannot kill a suite](https://forum.access-hive.org.au/t/cannot-kill-a-suite/3731)
**Author:** [@sonyafiddes](https://forum.access-hive.org.au/u/sonyafiddes)\ **Replies:** 6\ **Last updated:** [2 October 2024 23:05 UTC](https://forum.access-hive.org.au/t/cannot-kill-a-suite/3731 "2024-10-02T23:05:33Z")
Hi Team, I have a suite that has run successfully, but still seems to think it is running. rose sgc tells me ‘stopped with ‘succeeded’’ If I try cylc stop 'u-di850' I get: Cannot connect: https://cylc.slf563.jk72.p… --- ## [Running costs of UM7.3 vs UM10](https://forum.access-hive.org.au/t/running-costs-of-um7-3-vs-um10/3659)
**Author:** [@dkhutch](https://forum.access-hive.org.au/u/dkhutch)\ **Replies:** 3\ **Last updated:** [11 September 2024 01:13 UTC](https://forum.access-hive.org.au/t/running-costs-of-um7-3-vs-um10/3659 "2024-09-11T01:13:00Z")
Hi, After some interesting breakout discussions in the workshop, I was wondering, is there a benchmark comparison of running costs and walltime between UM7.3 and UM10, when both are run at N96 with the same number of ve… --- ## [On-line UM documentation from UKMO](https://forum.access-hive.org.au/t/on-line-um-documentation-from-ukmo/3653)
**Author:** [@Paul.Gregory](https://forum.access-hive.org.au/u/Paul.Gregory)\ **Replies:** 1\ **Last updated:** [9 September 2024 23:52 UTC](https://forum.access-hive.org.au/t/on-line-um-documentation-from-ukmo/3653 "2024-09-09T23:52:15Z")
Hi all. I know the UKMO used to maintain a single UM document, e.g. this is for UM4.4 https://ukscience.org/\_Media/UM\_User\_Guide.pdf I’m currently waiting for my MOSRS account to be re-activated, so I can’t access any … --- ## [Timeseries STASH output at list of grid-cells for UM versions running rose/cylc](https://forum.access-hive.org.au/t/timeseries-stash-output-at-list-of-grid-cells-for-um-versions-running-rose-cylc/2238)
**Author:** [@RachelLaw](https://forum.access-hive.org.au/u/RachelLaw)\ **Replies:** 9\ **Last updated:** [5 August 2024 22:53 UTC](https://forum.access-hive.org.au/t/timeseries-stash-output-at-list-of-grid-cells-for-um-versions-running-rose-cylc/2238 "2024-08-05T22:53:49Z")
Does anyone have experience with outputting model fields at every timestep for a selection of grid-cells for current version of the UM running under rose/cycl? We are trying to output land-surface related variables for … --- ## [Building UM executables: draft strategy](https://forum.access-hive.org.au/t/building-um-executables-draft-strategy/2233)
**Author:** [@paulleopardi](https://forum.access-hive.org.au/u/paulleopardi)\ **Replies:** 1\ **Last updated:** [18 July 2024 06:37 UTC](https://forum.access-hive.org.au/t/building-um-executables-draft-strategy/2233 "2024-07-18T06:37:10Z")
This post will contain a strategy for building current (UM13.X) UM executables on Gadi. Roughly, the goal is to be able to use Spack to build all relevant UM13.X executables from source code controlled by private GitHub … --- ## [Mosrs-auth not working after maintenance](https://forum.access-hive.org.au/t/mosrs-auth-not-working-after-maintenance/2071)
**Author:** [@sonyafiddes](https://forum.access-hive.org.au/u/sonyafiddes)\ **Replies:** 10\ **Last updated:** [6 May 2024 04:52 UTC](https://forum.access-hive.org.au/t/mosrs-auth-not-working-after-maintenance/2071 "2024-05-06T04:52:36Z")
Hi Team, @ZhangchengPei and I are having some issues with mosrs-auth today - see below. It looks like it has been updated, so does anyone know what we need to do to get it working? Cheers, Sonya \[slf563@gadi-login-04… --- ## [Nudging capabilities in ACCESS](https://forum.access-hive.org.au/t/nudging-capabilities-in-access/1338)
**Author:** [@Matt\_Woodhouse](https://forum.access-hive.org.au/u/Matt_Woodhouse)\ **Replies:** 5\ **Last updated:** [28 April 2024 23:54 UTC](https://forum.access-hive.org.au/t/nudging-capabilities-in-access/1338 "2024-04-28T23:54:55Z")
ACCESS-CM2/AM2 can be nudged with reanalysis meteorology (e.g. ERA5). Constraining the meteorology is useful in several applications (e.g. comparing model to composition measurements, sensitivity tests etc). There are a… --- ## [Fcm-make2.cfg file not found](https://forum.access-hive.org.au/t/fcm-make2-cfg-file-not-found/1819)
**Author:** [@sonyafiddes](https://forum.access-hive.org.au/u/sonyafiddes)\ **Replies:** 7\ **Last updated:** [15 February 2024 02:42 UTC](https://forum.access-hive.org.au/t/fcm-make2-cfg-file-not-found/1819 "2024-02-15T02:42:19Z")
Hi Team, I’m running into this error in jobs that have previously run… It has run on the persistent session before (last year), so I don’t think it is to do with that, but I could be wrong! \[FAIL\] fcm-make2.cfg: no suc… --- ## [Atmosphere-only science experiments with UM](https://forum.access-hive.org.au/t/atmosphere-only-science-experiments-with-um/1718)
**Author:** [@Michael\_Barnes](https://forum.access-hive.org.au/u/Michael_Barnes)\ **Replies:** 4\ **Last updated:** [29 January 2024 23:49 UTC](https://forum.access-hive.org.au/t/atmosphere-only-science-experiments-with-um/1718 "2024-01-29T23:49:17Z")
Hi all. I am interested in doing atmosphere-only, (relatively) coarse resolution model experiments and thought I would try and read up on the UM. Is there any local documentation of how one would go about designing and … --- ## [Nci\_era5grib no longer working](https://forum.access-hive.org.au/t/nci-era5grib-no-longer-working/1670)
**Author:** [@sonyafiddes](https://forum.access-hive.org.au/u/sonyafiddes)\ **Replies:** 10\ **Last updated:** [11 December 2023 01:28 UTC](https://forum.access-hive.org.au/t/nci-era5grib-no-longer-working/1670 "2023-12-11T01:28:26Z")
Hi Team, I’m trying to run a suite that has previously worked for me… using ERA5 as the driving model over the Antarctic coast line (I run twice - once un-rotated grid to generate ERA5 files, then rotated grid for the m… --- ## [UM partnership Mule repository and working practices](https://forum.access-hive.org.au/t/um-partnership-mule-repository-and-working-practices/1575)
**Author:** [@paulleopardi](https://forum.access-hive.org.au/u/paulleopardi)\ **Replies:** 2\ **Last updated:** [7 November 2023 22:40 UTC](https://forum.access-hive.org.au/t/um-partnership-mule-repository-and-working-practices/1575 "2023-11-07T22:40:34Z")
The MOSRS repository for Mule and its NCI mirror are: $ fcm kp | grep mule location{primary}\[mule.x\] = https://code.metoffice.gov.uk/svn/um/mule location{primary}\[mule.xm\] = file:///g/data/ki32/mosrs/um/mule The Mule w… [Next page](https://forum.access-hive.org.au/c/atmosphere/unified-model-um/20.md?page=1)