Process-oriented evaluation of quasi-stationary Rossby waves  and their impact on surface air temperature extremes  in dynamical downscaling over North America

Sakaguchi, Koichi; McGinnis, Seth A.; Leung, L. Ruby; Bukovsky, Melissa S.; McCrary, Rachel R.; Chen, Ziming; Chang, Chuan-Chieh; Li, Yanjie

doi:10.5194/gmd-19-3643-2026

Articles | Volume 19, issue 9

https://doi.org/10.5194/gmd-19-3643-2026

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

https://doi.org/10.5194/gmd-19-3643-2026

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

Articles | Volume 19, issue 9

Model evaluation paper

|

05 May 2026

Model evaluation paper |

| 05 May 2026

Process-oriented evaluation of quasi-stationary Rossby waves and their impact on surface air temperature extremes in dynamical downscaling over North America

Koichi Sakaguchi, Seth A. McGinnis, L. Ruby Leung, Melissa S. Bukovsky, Rachel R. McCrary, Ziming Chen, Chuan-Chieh Chang, and Yanjie Li

Data sets

ERA-Interim Project ECMWF https://doi.org/10.5065/D6CR5RD9

The NA-CORDEX dataset, version 1.0 L. O. Mearns et al. https://doi.org/10.5065/D6SJ1JCH

FACETS Dynamical Downscaling Simulations over North America by the CAM-MPAS Variable-Resolution Model Koichi Sakaguchi et al. https://doi.org/10.25584/PNNL.data/1895153

Model code and software

Scripts for Rossby Wave Evaluation of Dynamical Downscaling over North America Koichi Sakaguchi https://doi.org/10.5281/zenodo.17458434

Short summary

We evaluated Rossby waves in dynamical downscaling simulations over North America, and their connections to surface air temperature variability and heatwaves. Simulated Rossby wave propagation is distorted by flow discontinuities at lateral boundaries and by biased mean wind patterns, thereby breaking the region-specific connections between Rossby waves and surface temperature. Adjusting simulated large-scale winds to match the forcing data can reduce these biases.