The role of Rossby wave breaking in the formation and maintenance of tropical-extratropical cloud bands over the South Pacific

Pilon, Romain; De Vries, Andries Jan; Domeisen, Daniela I. V.

doi:10.5194/wcd-7-857-2026

Articles | Volume 7, issue 2

https://doi.org/10.5194/wcd-7-857-2026

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

https://doi.org/10.5194/wcd-7-857-2026

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

Articles | Volume 7, issue 2

Research article

|

29 May 2026

Research article |

| 29 May 2026

The role of Rossby wave breaking in the formation and maintenance of tropical-extratropical cloud bands over the South Pacific

Romain Pilon, Andries Jan De Vries, and Daniela I. V. Domeisen

Data sets

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

Model code and software

Supporting Files for The Role of Rossby Wave Breaking in the Formation and Maintenance of Tropical-Extratropical Cloud Bands over the South Pacific Romain Pilon https://doi.org/10.5281/zenodo.19919573

romainpilon/cloudbandPy: v1.2.2 - Bug Fix Romain Pilon https://doi.org/10.5281/zenodo.14639920

Short summary

South Pacific cloud bands are vital rain sources. Using historical weather data, we investigated how atmospheric waves from the midlatitudes shape these cloud bands. We found that long-lasting cloud bands require sustained high-altitude waves to continuously steer tropical moisture southward. These persistent events occur strictly during the summer. Understanding this dynamic link is essential for improving climate models and predicting how regional rainfall patterns may change in the future.