Vortex preconditioning of the 2021 sudden stratospheric warming: barotropic–baroclinic instability associated with the double westerly jets

Yoo, Ji-Hee; Chun, Hye-Yeong; Kang, Min-Jee

doi:https://doi.org/10.5194/acp-23-10869-2023

Articles | Volume 23, issue 19

https://doi.org/10.5194/acp-23-10869-2023

© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/acp-23-10869-2023

© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 23, issue 19

Research article

|

05 Oct 2023

Research article |

| 05 Oct 2023

Vortex preconditioning of the 2021 sudden stratospheric warming: barotropic–baroclinic instability associated with the double westerly jets

Ji-Hee Yoo, Hye-Yeong Chun, and Min-Jee Kang

Supplement

https://doi.org/10.5194/acp-23-10869-2023-supplement

Data sets

MERRA-2 inst3\_3d\_asm\_Np: 3d,3-Hourly, Instantaneous, Pressure-Level, Assimilation, Assimilated Meteorological Fields V5.12.4 GMAO (Global Modeling and Assimilation Office) https://doi.org/10.5067/QBZ6MG944HW0

MERRA-2 tavg3\_3d\_udt\_Np: 3d,3-Hourly, Time-Averaged,Pressure-Level,Assimilation, Wind Tendencies V5.12.4 GMAO (Global Modeling and Assimilation Office) https://doi.org/10.5067/CWV0G3PPPWFW

Download

Article (14057 KB)
Full-text XML

Short summary

The January 2021 sudden stratospheric warming was preceded by unusual double westerly jets with polar stratospheric and subtropical mesospheric cores. This wind structure promotes anomalous dissipation of tropospheric planetary waves between the two maxima, leading to unusually strong shear instability. Shear instability generates the westward-propagating planetary waves with zonal wavenumber 2 in situ, thereby splitting the polar vortex just before the onset.