The third Met Office Unified Model–JULES Regional Atmosphere and Land Configuration, RAL3

Bush, Mike; Flack, David L. A.; Lewis, Huw W.; Bohnenstengel, Sylvia I.; Short, Chris J.; Franklin, Charmaine; Lock, Adrian P.; Best, Martin; Field, Paul; McCabe, Anne; Van Weverberg, Kwinten; Berthou, Segolene; Boutle, Ian; Brooke, Jennifer K.; Cole, Seb; Cooper, Shaun; Dow, Gareth; Edwards, John; Finnenkoetter, Anke; Furtado, Kalli; Halladay, Kate; Hanley, Kirsty; Hendry, Margaret A.; Hill, Adrian; Jayakumar, Aravindakshan; Jones, Richard W.; Lean, Humphrey; Lee, Joshua C. K.; Malcolm, Andy; Mittermaier, Marion; Mohandas, Saji; Moore, Stuart; Morcrette, Cyril; North, Rachel; Porson, Aurore; Rennie, Susan; Roberts, Nigel; Roux, Belinda; Sanchez, Claudio; Su, Chun-Hsu; Tucker, Simon; Vosper, Simon; Walters, David; Warner, James; Webster, Stuart; Weeks, Mark; Wilkinson, Jonathan; Whitall, Michael; Williams, Keith D.; Zhang, Hugh

doi:https://doi.org/10.5194/gmd-18-3819-2025

Articles | Volume 18, issue 12

https://doi.org/10.5194/gmd-18-3819-2025

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

https://doi.org/10.5194/gmd-18-3819-2025

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

Articles | Volume 18, issue 12

Model description paper

|

30 Jun 2025

Model description paper |

| 30 Jun 2025

The third Met Office Unified Model–JULES Regional Atmosphere and Land Configuration, RAL3

Mike Bush, David L. A. Flack, Huw W. Lewis, Sylvia I. Bohnenstengel, Chris J. Short, Charmaine Franklin, Adrian P. Lock, Martin Best, Paul Field, Anne McCabe, Kwinten Van Weverberg, Segolene Berthou, Ian Boutle, Jennifer K. Brooke, Seb Cole, Shaun Cooper, Gareth Dow, John Edwards, Anke Finnenkoetter, Kalli Furtado, Kate Halladay, Kirsty Hanley, Margaret A. Hendry, Adrian Hill, Aravindakshan Jayakumar, Richard W. Jones, Humphrey Lean, Joshua C. K. Lee, Andy Malcolm, Marion Mittermaier, Saji Mohandas, Stuart Moore, Cyril Morcrette, Rachel North, Aurore Porson, Susan Rennie, Nigel Roberts, Belinda Roux, Claudio Sanchez, Chun-Hsu Su, Simon Tucker, Simon Vosper, David Walters, James Warner, Stuart Webster, Mark Weeks, Jonathan Wilkinson, Michael Whitall, Keith D. Williams, and Hugh Zhang

Supplement

https://doi.org/10.5194/gmd-18-3819-2025-supplement

Data sets

The third Met Office Unified Model-JULES Regional Atmosphere and Land configuration, RAL3 M. Bush et al. https://doi.org/10.5281/zenodo.13957006

Model code and software

The Joint UK Land Environment Simulator (JULES), model description – Part 2: Carbon fluxes and vegetation dynamics (http://jules-lsm.github.io/access_req/JULES_access.html) D. B. Clark et al. https://doi.org/10.5194/gmd-4-701-2011

metomi/fcm: M. Shin et al. https://doi.org/10.5281/zenodo.4775250

metomi/rose: Rose 2.4.2 M. Shin et al. https://doi.org/10.5281/zenodo.15169210

Short summary

RAL configurations define settings for the Unified Model atmosphere and Joint UK Land Environment Simulator. The third version of the Regional Atmosphere and Land (RAL3) science configuration for kilometre- and sub-kilometre-scale modelling represents a major advance compared to previous versions (RAL2) by delivering a common science definition for applications in tropical and mid-latitude regions. RAL3 has more realistic precipitation distributions and an improved representation of clouds and visibility.