Improvements to the Met Office's global ocean–sea ice forecasting system including model and data assimilation changes

Mignac, Davi; Waters, Jennifer; Lea, Daniel J.; Martin, Matthew J.; While, James; Weaver, Anthony T.; Vidard, Arthur; Guiavarc'h, Catherine; Storkey, Dave; Ford, David; Blockley, Edward W.; Baker, Jonathan; Haines, Keith; Price, Martin R.; Bell, Michael J.; Renshaw, Richard

doi:https://doi.org/10.5194/gmd-18-3405-2025

Articles | Volume 18, issue 11

https://doi.org/10.5194/gmd-18-3405-2025

© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/gmd-18-3405-2025

© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 18, issue 11

Model description paper

|

13 Jun 2025

Model description paper |

| 13 Jun 2025

Improvements to the Met Office's global ocean–sea ice forecasting system including model and data assimilation changes

Davi Mignac, Jennifer Waters, Daniel J. Lea, Matthew J. Martin, James While, Anthony T. Weaver, Arthur Vidard, Catherine Guiavarc'h, Dave Storkey, David Ford, Edward W. Blockley, Jonathan Baker, Keith Haines, Martin R. Price, Michael J. Bell, and Richard Renshaw

Supplement

https://doi.org/10.5194/gmd-18-3405-2025-supplement

Data sets

Global Ocean Along Track L3 Sea Surface Heights Reprocessed 1993 Ongoing Tailored For Data Assimilation E.U. Copernicus Marine Service Information https://doi.org/10.48670/moi-00146

Copernicus Marine In Situ – Global Ocean-Delayed Mode in situ Observations of surface (drifters, HFR) and sub-surface (vessel-mounted ADCPs) water velocity SEANOE https://doi.org/10.17882/86236

NEMO ocean engine, in: Scientific Notes of IPSL Climate Modelling Center (v4.2, Number 27) G. Madec et al. https://doi.org/10.5281/zenodo.6334656

EN4 quality controlled ocean data UK Met Office https://www.metoffice.gov.uk/hadobs/en4/download-en4-2-1.html

Short summary

We describe major improvements of the Met Office's global ocean–sea ice forecasting system. The models and the way observations are used to improve the forecasts were changed, which led to a significant error reduction of 1 d forecasts. The new system performance in past conditions, where subsurface observations are scarce, was improved with more consistent ocean heat content estimates. The new system will be of better use for climate studies and will provide improved forecasts for end users.