Role of in situ-excited planetary waves in polar vortex splitting during the 2002 Southern Hemisphere sudden stratospheric warming event

Yoo, Ji-Hee; Chun, Hye-Yeong

doi:https://doi.org/10.5194/acp-25-13651-2025

Articles | Volume 25, issue 20

https://doi.org/10.5194/acp-25-13651-2025

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

https://doi.org/10.5194/acp-25-13651-2025

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

Articles | Volume 25, issue 20

Research article

|

24 Oct 2025

Research article |

| 24 Oct 2025

Role of in situ-excited planetary waves in polar vortex splitting during the 2002 Southern Hemisphere sudden stratospheric warming event

Ji-Hee Yoo and Hye-Yeong Chun

Supplement

https://doi.org/10.5194/acp-25-13651-2025-supplement

Data sets

Modern-Era Retrospective analysis for Research and Applications, version 2 (MERRA-2) data Ronald Gelaro, Will McCarty, Max J. Suárez, Ricardo Todling, Andrea Molod, Lawrence Takacs, Cynthia A. Randles, Anton Darmenov, Michael G. Bosilovich, Rolf Reichle, Krzysztof Wargan, Lawrence Coy, Richard Cullather, Clara Draper, Santha Akella, Virginie Buchard, Austin Conaty, Arlindo M. da Silva, Wei Gu, Gi-Kong Kim, Randal Koster, Robert Lucchesi, Dagmar Merkova, Jon Eric Nielsen, Gary Partyka, Steven Pawson, William Putman, Michele Rienecker, Siegfried D. Schubert, Meta Sienkiewicz, and Bin Zhao https://doi.org/10.1175/JCLI-D-16-0758.1

European Centre for Medium-Range Weather Forecasts (ECWMF) ERA5 reanalysis project re-run for 2000-2006 (ERA5.1) Adrian Simmons, Cornel Soci, Julien Nicolas, Bill Bell, Paul Berrisford, Rossana Dragani, Johannes Flemming, Leo Haimberger, Sean Healy, Hans Hersbach, András Horányi, Antje Inness, Joaquín Muñoz-Sabater, Raluca Radu, Dinand Schepers https://doi.org/10.21957/rcxqfmg0

Japanese Reanalysis for Three Quarters of a Century Yuki Kosaka, Shinya Kobayashi, Yayoi Harada, Chiaki Kobayashi, Hiroaki Naoe, Koichi Yoshimoto, Masashi Harada, Naochika Goto, Jotaro Chiba, Kengo Miyaoka, Ryohei Sekiguchi, Makoto Deushi, Hirotaka Kamahori, Toshiyuki Nakaegawa, Taichu Y. Tanaka, Takayuki Tokuhiro, Yoshiaki Sato, Yasuhiro Matsushita, Kazutoshi Onogi https://doi.org/10.2151/jmsj.2024-004

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Short summary

This study revisits the Southern Hemisphere's only major sudden stratospheric warming in September 2002, marked by an unprecedented polar vortex split. In addition to upward-propagating planetary wave 2 (PW2), westward PW2 generated in-situ by barotropic–baroclinic instability, contributed to the vortex split. Unstable PW2 growth resulted from nonlinear wave-wave interactions and over-reflection. Vortex destabilization occurred as the anomalously poleward-shifted vortex reversed to easterlies.