An open source glacier model in Python https://oggm.org/ Wed, 01 Jul 2026 08:33:38 +0000 Wed, 01 Jul 2026 08:33:38 +0000 Jekyll v3.10.0 The OGGM team has just launched its first ever community consultation! The survey is open until May 17, 2026, at this link: OGGM community consultation 2026 All OGGM ecosystem users (or attempted users), as well as OGGM-Edu students, are invited to take part. Whether you have used OGGM, one of the OGGM-Edu apps, worked with OGGM-Hub, or downloaded OGGM products, we’d love to hear from you. The survey will remain open until May 17th. Many thanks for your time! This will directly help us shape the future of OGGM. Tue, 21 Apr 2026 00:00:00 +0000 https://oggm.org/2026/04/21/survey/ https://oggm.org/2026/04/21/survey/ announcement We’re happy to announce the release of OGGM v1.6.3, the final update in the 1.6.x series. This is a fully backwards-compatible release bringing a wide range of bug fixes, improvements, and updated standard projections. A big thank you to the 8 contributors who made this release possible! A new generation of glacier directories The main highlight of v1.6.3 is a new generation of preprocessed glacier directories. These updates mostly improve data quality and consistency behind the scenes, while keeping results close to previous versions. Key additions include: Full support for RGI7 workflows ERA5-calibrated directories extended to 2025 New directories including avalanche maps Updated datasets (e.g. ITS_LIVE v2, GlaThiDa) and several bug fixes A switch to the UTM projection and improved global topography (COPDEM) Overall, differences with previous directories (v1.6.1) remain small by design, with larger changes only when using the new ERA5 or RGI7 products. For more context, see our previous blogpost on glacier directories and projections. Model and workflow improvements This release also brings several notable model updates: Calving now supported in the default SemiImplicitModel Continued development of Glacier3dViz and its thickness distribution tools New calibration and diagnostics options (e.g. quantiles across projections) Improved flexibility in parameter handling and workflows We’ve also streamlined installation (including support for uv) and improved performance in several core routines. New tutorials To help you get started, we added: Two new tutorials showcasing the updated glacier directories One tutorial on glacier runoff sensitivity analysis Explore them at https://tutorials.oggm.org Looking ahead: v1.7 While v1.6.3 wraps up the 1.6 series, development is moving fast. OGGM v1.7 is around the corner, with major updates already underway, including: Moving the daily mass balance model into core OGGM Improved parameter handling and workflows Preparations for GlacierMIP4 Stay tuned — more to come soon! 🙏 Thanks again to everyone who contributed to this release! Wed, 15 Apr 2026 00:00:00 +0000 https://oggm.org/2026/04/15/v163/ https://oggm.org/2026/04/15/v163/ announcement We are pleased to announce the start of OGGM-Next, a new 12-month project aimed at modernising the Open Global Glacier Model (OGGM) and securing its role as a core piece of global glacier modelling infrastructure. The project is funded by the UK Research Software Maintenance Fund and will officially start in April 2026. Why OGGM-Next? Over the past decade, OGGM has grown into a widely used, community-driven model capable of simulating all ~280,000 glaciers worldwide. It underpins many scientific studies, contributed to IPCC assessments, and supports applications ranging from hydrology to climate risk analysis. At the same time, OGGM is now showing its age. Some of its code date back to 2015, and while it has evolved continuously, parts of the system are increasingly difficult to maintain, extend, or adapt to modern workflows. Meanwhile, the scientific landscape is moving fast. New approaches such as ensemble modelling, machine learning, and digital twins require more modular, scalable, and cloud-ready tools. OGGM-Next is about making sure OGGM keeps up with these evolutions. Project overview Duration: 12 months (April 2026 – March 2027) Funding: £150,000 (£187,000 Full Economic Cost) Lead: Fabien Maussion (University of Bristol) Co-leads: Francesca Pianosi, James Thomas Core team: Nicolas Gampierakis (Research Software Engineer), Chloe Hancock (Research Associate), Richard Westaway (Project Managemer) Partners: University of Edinburgh, Leeds Beckett University, British Geological Survey, University of Lausanne, Carnegie Mellon University, University of Bremen What we will work on OGGM-Next is structured around four main priorities: 1. Reducing technical debt OGGM has an extensive test suite and a mature code base — but both have grown organically over time. We will streamline and simplify the testing infrastructure, making it easier to maintain and faster to develop new features. 2. Modernising model configuration Current parameter handling in OGGM makes large ensemble experiments and model coupling harder than they should be. We will: standardise parameter handling across the model, ensure full reproducibility of simulations, and test modern frameworks (e.g. Hydra) for future workflows. 3. Making OGGM cloud-ready OGGM outputs are currently distributed as downloadable archives, which limits discoverability and efficient use. We will transition to: cloud-native data formats (GeoZarr), object storage access, and improved metadata and discoverability. The goal is simple: access only the data you need, without downloading everything. 4. Improving documentation and training OGGM already has extensive documentation and tutorials — but they are spread across multiple platforms and can be hard to navigate. We will: reorganise documentation around user needs, create clearer “getting started” pathways, and develop structured training material. The project will conclude with an online train-the-trainers workshop, with a focus on supporting users in the Global South. A project aligned with a broader moment OGGM-Next comes at a timely moment. The United Nations has declared 2025–2034 the Decade of Action for Cryospheric Sciences, and the next IPCC assessment cycle is already underway. At the same time, multiple UK and international projects are actively relying on OGGM. Investing in the model’s foundations now ensures that it remains robust, transparent, and fit for purpose in the years ahead. What OGGM-Next is (and is not) OGGM-Next is not a science project in the traditional sense. We are not adding new physical processes or building new infrastructure from scratch. Instead, the focus is on: improving the software itself, reducing maintenance burden, and enabling future science. In short: this is an investment in the foundations. Follow the project We will share updates as the project progresses, including technical developments, documentation improvements, and training opportunities. OGGM website: https://oggm.org Code: https://github.com/OGGM/oggm Education platform: https://edu.oggm.org As always, feedback from the community is welcome. OGGM-Next aims to ensure that OGGM remains a sustainable, open, and widely used tool for glacier modelling — ready for the next decade of cryospheric science. Mon, 23 Mar 2026 00:00:00 +0000 https://oggm.org/2026/03/23/oggm-next/ https://oggm.org/2026/03/23/oggm-next/ announcement OGGM joined Twitter in 2018, a couple of years after the project was created. Over the years, we made many connections there and reached audiences beyond the usual scientific bubble. Twitter has since become X, and OGGM stopped posting in 2023. The account will be deleted soon. The tweets below form a static archive of that period. A small record of a time when the platform played a positive role in scientific exchange. Sun, 08 Feb 2026 00:00:00 +0000 https://oggm.org/2026/02/08/tweet-archive/ https://oggm.org/2026/02/08/tweet-archive/ outreach OGGM provides preprocessed glacier directories (“gdirs”), i.e. ready-to-use datasets containing all input data and standard preprocessing steps computed consistently. With version 1.6.3 (to be released in March 2026), OGGM provides a new set of preprocessed directories. These are either updates of the v1.6.1 ones, or new directories using updated climate data (ERA5) and RGI version 7 glacier outlines. This blog post summarizes the available preprocessing options and their effects on failing glaciers and volume projections. In a nutshell: OGGM v1.6.1 and v1.6.3 produce nearly identical projections. Baseline climate (W5E5 vs ERA5) has little global impact but causes persistent regional differences, notably in New Zealand (region 18). Regional calibration lowers projected volumes in Central Asia (13). Updating from Randolph Glacier Inventory (RGI) 6.2 to RGI 7.0 reduces failing glacier area in North Asia (10) and the Caucasus and Middle East (12), which causes around 15% larger glacier volumes in year 2000 in these regions. Globally, 2000 volumes between RGI inventories are similar, but around ~15% smaller in the Low Latitudes (16) and New Zealand (18). Projection differences until 2100 using RGI7.0 instead of RGI6.2 are affected by the initial volume and regional spinup calibration. Overall, OGGM version and preprocessing option projection differences are smaller than differences to GloGEM or PyGEM, and smaller than differences between climate model forcing options. Available options OGGM v1.6.1 standard projections: 2023.3, W5E5, RGI62, per_glacier_spinup (gdir link): the previous OGGM standard projections using OGGM v1.6.1, with W5E5 as baseline climate, RGI62 as glacier inventory, and dynamical spinup and calibration performed individually for each glacier OGGM v1.6.3 standard projections: 2025.6, W5E5, RGI62, per_glacier_spinup (gdir link): the same as above, but using OGGM v1.6.3 with the 2025.6 preprocessed glacier directory (differences between versions described in the OGGM version history) 2025.6, ERA5, RGI62, per_glacier_spinup (gdir link): same as the OGGM v1.6.3 standard projections, but using ERA5 instead of W5E5 as baseline climate for the calibration. Note that ERA5 has a higher spatial resolution (0.25° × 0.25° grid) than W5E5 (0.5°). Both datasets were bias-corrected during the same time period (Jan 2000 – Dec 2019). 2025.6, W5E5, RGI62, regional_spinup (gdir link): same as the OGGM v1.6.3 standard projections, but every glacier was calibrated to match the regional specific mass balance instead of the individual glacier-specific mass balance (similar as in Zekollari et al. (2024)). This experiment has been develloped mostly as comparison baseline for RGI7 (see below). 2025.6, W5E5, RGI70G, regional_spinup (gdir link): same as above, but using the RGI70G inventory instead of RGI62. Differences between RGI versions are described in the RGI documentation. Like above, the calibration is done based on the regional MB values from Hugonnet et al., and precipitation correction factor and temperature bias values are chosen the same way as for the default experiment (but with the regional MB values as reference). 2025.6, W5E5, RGI70C, regional_spinup (gdir link): same as above, but using the glacier complex product (RGI70C; more details here), which results in fewer “glaciers” in total instead of individual glaciers. Both versions of the OGGM standard projections are available (as regionally or globally aggregated datasets, or as per-glacier files) at https://github.com/OGGM/oggm-standard-projections-csv-files for all climate models and scenarios available from the cluster. For the other four options, we tested projections for a single climate model and several scenarios. All notebooks and data used for this blog post are in this OGGM cluster folder. Further details in the OGGM documentation. Error analysis Fig. 1: Failing glacier area (% of RGI area) for each region and globally for different preprocessed OGGM v1.6 glacier directories. The same figure for the number of failing glaciers is available here. Here is the notebook used to create the figure and additional analyses. “Failing glacier area” refers to the total area of glaciers for which the OGGM preprocessing workflow cannot be completed and which are therefore excluded from the projections. For all analysed preprocessed glacier directories, the glacier area that fails at any point in the OGGM preprocessing workflow is globally below 0.2%. Less than 1% of the glacier area fails in all regions except North Asia (10) and Caucasus and Middle East (12). The failing glacier area is slightly reduced for the OGGM v1.6.3 standard projections compared to OGGM v1.6.1, likely due to the use of newer topographical maps in the Subantarctic and Antarctic Islands (19). Using ERA5 instead of W5E5 results in a similar failing glacier area. Calibrating glaciers at the regional level instead of per glacier slightly reduces the failing glacier area globally, but increases the failing glacier area in the Low Latitudes (16) to 0.7%. Using RGI70G or RGI70C instead of RGI62 (all calibrated at the regional level) drastically reduces the failing glacier area in North Asia (10) and the Caucasus and Middle East (12), from almost 4 % and 12 % to less than 0.1 %, because of replaced outlines in RGI 7.0 (see 1, 2). However, in Arctic Canada North (03; only for RGI70G) and in the Subantarctic and Antarctic Islands (19; for both RGI70G and RGI70C), slightly more glacier area fails compared to RGI62. Why the latter occurs is unclear and should be investigated. Although RGI70G results globally in around 2.5 times more failing glacier area than RGI62, the failing area remains negligible on the global scale (<0.2%). The much higher quality of RGI 7.0 and the substantial reduction of errors in some regions outweigh this slight failing glacier area increase. Calibration performance Fig. 2: Percentage of glaciers reaching “full success” in the dynamical spinup calibration. Here is the notebook that created the figure and includes additional analysis. All preprocessed glacier directories apply the dynamical spinup, which ensures that OGGM matches the glacier area at the RGI date and the glacier mass balance during the 2000–2020 simulation, taking elevation feedbacks into account. If a glacier reaches “full success” in the dynamical calibration, this means that a melt factor can be found that matches during the dynamic historical projection the observed geodetic mass balance within 20% of the error estimate provided by Hugonnet et al. (2021), while matching at the same time the glacier area at RGI date. The “full success” performance varies strongly between regions and between preprocessed glacier directories (ranging from 8 to 99% of glaciers). When calibrating each glacier individually, around 85% of glaciers globally reach full success. When applying the calibration at the regional level, around 5% fewer glaciers succeed globally (with around 10% fewer glaciers succeeding in five regions, but also three regions showing around 5% higher success rates). The much poorer success of the regional calibration specifically in New Zealand (18) may be related to the many small glaciers in that region, which have a much less negative geodetic mass balance than the regional mean (see Zekollari et al. (2024), Fig. 1). Using RGI70G instead of RGI62 does not lead to important differences globally. However, using RGI70G improves the success rate by almost 40% in New Zealand (18; likely due to updating outlines from 1978/1988 to roughly 2000) and by around 10% in the Subantarctic and Antarctic Islands (19), while it reduces the success rate by about 13% in the Low Latitudes (16). In most regions, we find a relatively good match of the modelled regional mass change in absolute numbers (Fig. 3). If the dynamical spinup and the match to Hugonnet et al. (2021) were perfect, we would expect the modelled regional 2000–2020 mass change to correspond exactly to the geodetic estimates from Hugonnet et al. (2021). However, the dynamical spinup can fail, and even for successful glaciers the per-glacier mass balance is allowed to deviate within 20% of the reported error range. Fig. 3: Total mass loss by RGI region after the dynamical run. The largest discrepancies in absolute 20-year mass change occur in the Subantarctic and Antarctic Islands (19), where the regional mass loss obtained using RGI62 is around 50% higher than the observations from Hugonnet et al. (2021) that were used for the calibration. Other glacier models (GloGEM, PyGEM) show a similarly strong or even larger mismatch in this region. This strong mismatch is no longer visible when using RGI70 with OGGM. One possible explanation is the lower dynamical calibration success rate for RGI62 compared to RGI70, although in other regions different success rates do not necessarily lead to different modelled regional glacier mass losses. Another explanation could be the large inventory year differences, which are particularly pronounced for Subantarctic and Antarctic Islands (19) (glacier area-weighted median year is 1986 for RGI62, and 1997 for RGI70G, see also the different historical volume evolution). When comparing regionally dynamically modelled and observed mass balance (link to figure), larger discrepancies are also visible in the Low Latitudes (16) and in New Zealand (18). Some systematic differences between per-glacier and regionally calibrated gdirs are apparent in the modelled regional mass balance. These may be explained by differences in how the initial area is treated and how glacier area evolves over time. The “regional_spinup” gdirs are calibrated using region-specific mass-balance values from Hugonnet et al. (2021), which differ in some regions from the glacier-area-weighted average of the per-glacier values. This is because the per-glacier geodetic mass-balance observations are defined using a constant RGI area, while the regional values vary over time. Another potential explanation for some differences is that OGGM filters out per-glacier geodetic mass-balance values with very large uncertainties, and uses for these glaciers (and for those with no measurements), the regional mass-balance estimate (link to OGGM doc). When considering only the fixed-geometry mass balance (link to figure), it becomes clear that the “regional_spinup” gdirs are calibrated towards the sometimes more negative regionally estimated mass-balance values compared to the “per_glacier_spinup” gdirs, which are calibrated using individual glacier observations. However, the absolute regional mass-change estimates are almost identical when using regional instead of per-glacier calibration (<1% difference in all regions except New Zealand (18), where the difference is around 2%), suggesting that integrated historical mass change may be a more robust metric to consider. Global and regional glacier volume projection differences Fig. 4: Glacier projection differences in 2000 and 2100 relative to the OGGM v1.6.3 Standard Projections for different OGGM v1.6 preprocessed glacier directories. Numbers are given in % relative to the 2000 OGGM v1.6.3 Standard Projections. We used only one climate model (MRI-ESM2-M) and one scenario (SSP1-2.6) for the comparison and aggregated all glaciers, even though some options contain more failing glaciers than others. Restricting the analysis to “commonly running glaciers” leads to negligible differences (<0.5% in all regions except the Low Latitudes (16), with ~1% differences) For comparison, we also include the Farinotti et al. (2019) community volume estimate, which is valid at the RGI62 inventory date. Link to figure with volume projections from 2000 to 2100, including GloGEM and PyGEM. Link to notebook used for the analysis. Globally, glacier volume projection differences between the options are negligible. Differences are up to 1% in 2000 (RGI70C vs OGGM v1.6.3), decreasing to <0.1% in 2100 under SSP1-2.6 (or remaining at roughly 1% for higher-emission scenarios). Regionally, some differences are visible, but these are much smaller than the differences to GloGEM and PyGEM (see comparison figure). Although OGGM RGI62 gdirs were calibrated to match regional Farinotti et al. (2019) volumes at the inventory date, year 2000 glacier volumes from OGGM using RGI62 may differ from this estimate for several reasons: The Farinotti et al. (2019) estimate is valid at the RGI62 inventory date, which differs substantially from the year 2000 in some regions. How the volume changes from that year to 2000 is different for each option, which also explains the 2000 volume differences between the options. While regional OGGM inversion volumes should match the Farinotti et al. (2019) community estimate by calibration, North Asia (10) and Caucasus and Middle East (12) contain a considerable amount of failing glacier area, which explains why the inversion volume of these two regions is around 6% smaller than the community estimate (link to figure). Let’s now compare the projections for each option individually: Differences between the OGGM v1.6.1 and v1.6.3 Standard Projections remain within 2% over the entire projection period in all regions; globally, differences are <0.5%. At the beginning of the projections (year 2000), the OGGM v1.6.3 Standard Projection preprocessed glacier directory is within ±8% of the Farinotti et al. (2019) community estimate in all regions. Using ERA5 instead of W5E5 leads to differences of 4–11% relative to the OGGM v1.6.3 Standard Projections in 2000 for the Caucasus and Middle East (12), Low Latitudes (16), and New Zealand (18). In New Zealand (18) and in the Russian Arctic (09) estimated absolute projection differences in 2100 are above 4%. Differences in regional climate evolution between the RGI date and the inversion date may explain part of the initial volume discrepancies. However, OGGM–ERA5 projections are not substantially closer to GloGEM and PyGEM, which have also used ERA5. Other differences, such as model physics, calibration and initial volumes may hide the influence of the baseline climate choice. The regional calibration does not create large projection differences globally and for most regions, as per-glacier differences are compensated at the regional scale (see e.g. Zekollari et al. (2024). However, regional calibration creates an around 4% lower 2000 glacier volume in New Zealand (18) with diminishing differences until 2100. In addition, glacier volume projections in Central Asia (13) are around 9% lower in 2100 with the regional calibration (similar tendency found for this region in Zekollari et al., 2024 (Fig. 4)). With the largest number of glaciers, this region is more strongly affected by regional calibration than smaller regions. Because the same regionally calibrated “Glen A” parameters derived from RGI62 were applied to RGI70G, any inversion volume differences between the RGI versions arise solely from updated glacier outlines and inventory years, not from changes in data or methods. This results in inversion volumes that are over 10% larger in North Asia (10) and the Caucasus and Middle East (12) (partly because RGI7 contains much less failing glacier area), and over 15% smaller in the Low Latitudes (16) and New Zealand (18) (link to figure). Inversion volumes are valid at different years for RGI62 and RGI70, so differences between the preprocessed gdirs can be even larger in 2000 than at inversion (Fig. 4). Over time, projection differences decrease in regions with the largest initial discrepancies. Some remaining differences in 2100 are due to the regional calibration, as both RGI62 and RGI70 gdirs with regional calibration produce similar 2100 projections in several regions. Using glacier complexes (RGI70C) instead of individual glaciers (RGI70G) leads to substantial volume differences (>4%) in four regions in 2000 and to a ~1% larger global volume. By 2100, estimated absolute volume differences decrease globally and in these four regions, but appear instead in two other regions. Discussion Which preprocessed glacier directory should you use? In many cases, the preprocessed glacier directory from the OGGM v1.6.3 Standard Projections (gdir link) is a good choice. Using ERA5 has the advantage that climate data goes until 2025, which is very useful for some applications. In some regions, ERA5-calibrated glacier directories are quite different, calling for more investigation. The regional calibration glacier directories are experimental and were mainly created for comparison with RGI70, where per-glacier observational data are not yet available. Should you already use the RGI70G preprocessed glacier directors (gdir)? The currently available RGI70G preprocessed gdirs are only calibrated regionally by assuming that the RGI70 mass-balance is regionaly similar to RGI62. Thus, we recommend to wait until per-glacier calibrated gdirs are available (latest until April 2026). We expect to see some differences when using geodetic observations directly estimated from the RGI70 outlines. What does this mean for GlacierMIP4? Assuming RGI62 to be valid in the year 2000 leads to substantially different 2000 glacier volumes compared to current OGGM projection estimates with spinup. RGI70G is closer to the year 2000 (for regions 10, 18, and 19), which reduces these differences under such an assumption (as planned for GlacierMIP4). However, when comparing glacier volume projections between RGI62 and RGI70G, it is necessary to clarify the sources of these differences: whether they arise from the updated glacier outlines themselves, from the different valid inventory years, or from inventory-specific initialization assumptions that may perform better for one dataset than for the other. Historical mass changes from 2000 to 2020 can differ between glacier models (and options), even though they were all “calibrated” to the same geodetic mass-balance estimates. Some of the projection differences between preprocessed glacier directories within OGGM may help interpret later differences in GlacierMIP4 projections. Wed, 07 Jan 2026 00:00:00 +0000 https://oggm.org/2026/01/07/oggm_v16-gdirs-and-projection-options/ https://oggm.org/2026/01/07/oggm_v16-gdirs-and-projection-options/ science Following the recent publication of the Nature Climate Change paper “Peak glacier extinction in the mid-twenty-first century”, OGGM developer Fabien Maussion has written a short blog post discussing glacier numbers. Read the full post here: https://fabienmaussion.info/2025/12/13/glacier_numbers Mon, 22 Dec 2025 00:00:00 +0000 https://oggm.org/2025/12/22/glacier-numbers/ https://oggm.org/2025/12/22/glacier-numbers/ outreach Here comes a short summary of the 9th OGGM workshop, which was hosted by the Water and Climate Department of the Vrije Universiteit Brussel (VUB), Belgium. Our summary is a few months delayed and even comes after the announcement of the next workshop; but better late than never ;-) This year’s workshop was shorter, more OGGM-focused, and, unlike previous years, did not include any hands-on or beginner sessions. Apart from the usual OGGM crew, we also had participants from our sister models, e.g. people working with IGM, ODINN, GloGEM or the massbalance-machine. The programme included individual presentations on “large-scale OGGM applications and other related global glacier models” as well as on “OGGM-related processes”, with plenty of time reserved for open discussions of the presented topics. Group picture and group discussion; credits: Harry Zekollari We also had dedicated group discussions on “OGGM central activities” to provide updates on the status of OGGM and its governance, as well as on “Glacier-related hydrology”, “Machine learning for glacier modelling”, and “Future OGGM plans”. In addition, we discussed potential OGGM contributions to GlacierMIP4 and had time for specific additional topics in small groups. On the first evening, the locals organised a short sightseeing tour of Brussels, which concluded in a cosy brasserie with plenty of food and drinks. Evening activites; Credits: Harry Zekollari We are already looking forward to celebrating the 10th OGGM workshop, which will take place in August 2026 in Obergurgl, Austria. Acknowledgements We would like to thank everyone for coming to the workshop, and specifically all the organisers, especially Nicolas Champollion, Harry Zekollari, Loreline Faugier, and Rodrigo Aguayo. Many thanks also to the Department of Water and Climate at the Vrije Universiteit Brussel for hosting us and for providing food and drinks throughout the workshop. Wed, 17 Dec 2025 00:00:00 +0000 https://oggm.org/2025/12/17/9th-oggm-workshop-summary/ https://oggm.org/2025/12/17/9th-oggm-workshop-summary/ workshop The next Global Glacier Modelling Workshop will be held at the University Centre Obergurgl, in the Austrian Alps, from Monday 24 August to Friday 28 August 2026. New (March 23rd, 2026): registration for the workshop is now closed! Registered participants will be informed about the outcome shortly. What is it? The workshop continues the tradition of bringing together the global glacier modelling community — developers and users alike — to share advances, exchange ideas, and foster collaboration. It follows the successful workshop in Oslo in 2025 and builds on the series of workshops organised by the OGGM consortium since 2016. We welcome anyone interested in large-scale glacier evolution modelling and related challenges (e.g. observational datasets at large scales). “Large-scale” here refers to the ability to simulate or monitor at least one entire RGI region. This edition is special in two ways: It marks the 10th anniversary of the first OGGM workshop in Obergurgl. A small celebration will definitely be in order! We will host a dedicated GlacierMIP4 session, focusing on the next phase of the Glacier Model Intercomparison Project. Participants in GlacierMIP4 are especially encouraged to attend (remote participation will be offered for this session). Topics Modelling of glaciers at regional to global scales Glacier change projections and associated impacts (hydrology, hazards, sea-level rise), as well as paleo-simulations and glacier reconstructions Sensitivity of large-scale glacier evolution models to climate forcing, input datasets, and model parameterisation choices Advances in modelling climatic mass balance, frontal ablation, and ice dynamics in large-scale frameworks, including process-based and machine-learning approaches Calibration and validation of glacier evolution models Data assimilation, ice-thickness inversion, and integration of heterogeneous observational datasets Development and use of large-scale datasets relevant for global glacier modelling Agenda The agenda will be developed in the lead-up to the workshop. We aim to maintain a flexible schedule that adapts to participants’ needs, interests, and suggestions. Typically, sessions will include oral and poster presentations, group discussions, hands-on activities, and open brainstorming. Venue The workshop will take place at the University Centre Obergurgl from Monday 24 August to Friday 28 August 2026. Obergurgl can be reached by taking a train to Ötztal Bahnhof on the Innsbruck–Zürich line, followed by a bus to the village of Obergurgl. Nearby transport hubs include Innsbruck (closest), Munich, and Zurich. Costs Participants can expect: a conference fee of €250 to cover meeting facilities and coffee breaks (these costs might be lowered pending ongoing funding acquisition efforts); accommodation costs of €99 per person per night in shared rooms or €139 per person per night for single rooms (limited availability), including breakfast and dinner. Registration (opened until March 22, 2026) Registration is now closed! Thanks for your interest in the workshop. Important dates Indicative timeline: February 2026 — Call for abstracts & registration opens April 2026 — Participants informed of acceptance April 2026 — Waiting list notifications (if needed) May 2026 — First programme draft published August 2026 — Workshop! Organizers Local organising committee: Fabien Maussion, Ben Marzeion, Ritu Anilkumar Scientific advisory board: Jordi Bolibar, Nicolas Champollion, Regine Hock, Matthias Huss, Guillaume Jouvet, Beatriz Recinos, David Rounce, Harry Zekollari For any questions or requests for information, please contact Fabien Maussion. Mon, 08 Dec 2025 00:00:00 +0000 https://oggm.org/2025/12/08/10th-workshop-announcement/ https://oggm.org/2025/12/08/10th-workshop-announcement/ workshop The workshop is the 9th in a series that has brought together the community of users and developers of the Open Global Glacier Model (OGGM). This year, the workshop will be shorter and OGGM-focused over 3 days, as always in an informal and friendly atmosphere. The workshop welcomes active or soon-to-be-active large-scale glacier modellers, in particular users and developers of OGGM. Its primary objective is to address current challenges in glacier modeling, foster mutual learning, and discuss ideas and visions for advancing glacier models and their governance. Attendees can expect a mix of scientific presentations and discussion/brainstorming sessions. Unlike previous years, no hands-on or beginner sessions are planned. Topics modelling of glaciers at large scales (mountain range to global scale) glacier change projections and impacts of glacier change (hydrology, hazards, sea-level rise) data assimilation and ice thickness inversion paleo-simulations and glacier reconstructions model development, calibration, validation visualisation of glacier model results future of OGGM: perspectives, governance, sustainability Agenda We aim to maintain a flexible schedule that adapts to the participants’ needs, interests, and suggestions. Typically, the first afternoon will be reserved for presentations, the second day dedicated to group discussions, and the last morning to the future of OGGM. All sessions will happen with all participants (no parallel sessions). Scientific presentations: Participant presentations (approx. 5–20 minutes) on topics relevant to the workshop. Discussion/brainstorming sessions: Covering all aspects of OGGM and global glacier modeling. Future session: Addressing long-term needs and societal relevance of glacier modelling, especially in the context of OGGM. Who can participate? The workshop is open to anyone involved in glaciological modelling. Please note that participant numbers are limited to around 15–20 due to accommodation and logistical constraints. Location The workshop will be held at the Vrije Universiteit Brussel (Belgium). The Vrije Universiteit Brussel (VUB) is a Dutch- and English-speaking research university in Brussels, Belgium, formed in 1970. The university covers a broad range of disciplines, including natural sciences, life sciences, social sciences, humanities, and engineering. It provides bachelor’s, master’s, and doctoral education to about 8,000 undergraduate and 1,000 graduate students. Transportation VUB is easily accessible by public transport from Brussels’ main train stations or the airport. Arrival / departure dates The workshop starts at VUB on October 6, 2025 in the early afternoon and ends on October 8, 2025 before lunch. This should give participants time to arrive on Monday morning and leave on Wednesday afternoon. Accommodation / meals and workshop fee There is no workshop fee, but the organisers do not cover accommodation, travel, or meals. Each participant is responsible for their own expenses. We will explore options for staying on campus and update you with any available possibilities. Registration procedure If you are interested in participating, please complete the registration form by June 15th. Please note that participation is limited to 15–20 people. If we receive more applications than available spots, a selection process will be carried out based on responses in the form. Selected participants will be notified by early July. For any questions, feel free to contact us at info@oggm.org. Organizers Nicolas Champollion, Rodrigo Aguayo, Harry Zekollari, Fabien Maussion and Ben Marzeion Acknowledgements Sun, 18 May 2025 00:00:00 +0000 https://oggm.org/2025/05/18/9th-workshop-announcement/ https://oggm.org/2025/05/18/9th-workshop-announcement/ workshop A scheduled maintenance will require a shutdown of the OGGM cluster from the evening of April 27 to the morning of April 30 (CEST). The OGGM websites—including the documentation, OGGM-Edu, and tutorials—will remain operational. However, the OGGM cluster will be unavailable during this period. This means: OGGM will not be able to download data from the server The OGGM Hubs will not be able to access the OGGM cluster This will not affect the OGGM code itself, but it will prevent you from running OGGM locally if your workflow depends on downloading data from the OGGM server. Tue, 15 Apr 2025 00:00:00 +0000 https://oggm.org/2025/04/15/service-maintenance/ https://oggm.org/2025/04/15/service-maintenance/ announcements