Grid-spacing sensitivity of Rossby wave breaking to mesoscale diabatic processes

Rixen, Marius; Pothapakula, Praveen K.; Sprenger, Michael; Zeman, Christian; Prein, Andreas F.

doi:10.5194/wcd-7-2065-2026

Articles | Volume 7, issue 4

https://doi.org/10.5194/wcd-7-2065-2026

© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/wcd-7-2065-2026

© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 7, issue 4

Research article

|

20 Oct 2026

Research article |

| 20 Oct 2026

Grid-spacing sensitivity of Rossby wave breaking to mesoscale diabatic processes

Marius Rixen, Praveen K. Pothapakula, Michael Sprenger, Christian Zeman, and Andreas F. Prein

Data sets

ERA5 hourly data on single levels from 1940 to present H. Hersbach et al. https://doi.org/10.24381/cds.adbb2d47

Integrated Multi-satellitE Retrievals for GPM (IMERG) technical documentation G. J. Huffman et al. https://doi.org/10.5067/GPM/IMERG/3B-HH/07

The Multi-Scale Interactions of Atmospheric Phenomenon in Mean and Extreme Precipitation (https://github.com/andreas-prein/MOAAP) A. F. Prein et al. https://doi.org/10.1029/2023EF003534

Model code and software

mariusrixen/Rixen_et_al_2026_Grid_spacing_RWB: Grid-Spacing Sensitivity of Rossby Wave Breaking to Mesoscale Diabatic Processes M. Rixen https://doi.org/10.5281/zenodo.19347928

EXCLAIM use cases A. Dipankar https://doi.org/10.5281/zenodo.17255275

Short summary

Despite steady improvements in forecasting skill, episodes of low forecast skill, called forecast busts, still persist. Using global ensemble simulations at different grid spacings, we show that coarse-grid simulations fail to resolve key mesoscale diabatic processes, and that errors upscale and propagate downstream, leading to large forecast errors. Fine grid spacing simulations better capture scale interactions in strongly diabatic flow, highlighting the potential of kilometer-scale models.