Influence of the Quasi-Biennial Oscillation on the Spatial Structure of the Wintertime Arctic Oscillation

Qingyu Cai, Wen Chen*, Shangfeng Chen, Tianjiao Ma, Chaim I. Garfinkel

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

8 Scopus citations

Abstract

This study reveals that the Quasi-Biennial Oscillation (QBO) has a marked impact on the spatial structure of the Arctic Oscillation (AO) in boreal winter. In particular, the North Pacific center (NPC) of the AO is stronger during the westerly phase of the QBO (WQBO) than the easterly phase of the QBO (EQBO). In other words, the variability associated with the AO over the North Pacific is stronger in WQBO years than EQBO years, even though the overall variability is insensitive to QBO phase. The QBO is suggested to influence the spatial pattern of the winter AO mainly via modulating the intensity of the stratospheric polar vortex, with a stronger stratospheric polar vortex during WQBO than EQBO years. A stronger stratospheric polar vortex can lead to more planetary wave refraction and facilitate the eastward propagation of wave activity flux from the mid-latitude North Pacific to the North Atlantic. Thus an enhanced connection between North Pacific and North Atlantic atmospheric variability is established, and a more prominent NPC of the AO occurs in WQBO years. In addition, the modulation of the AO structure by the QBO and the associated physical process is supported by output from the CNRM-CM6-1 model. Our results indicate that, for seasonal climate prediction in North America based on the AO, WQBO leads to a larger predictable signal while EQBO leads to reduced skill.

Original languageAmerican English
Article numbere2021JD035564
JournalJournal of Geophysical Research: Atmospheres
Volume127
Issue number8
DOIs
StatePublished - 27 Apr 2022

Bibliographical note

Publisher Copyright:
© 2022. American Geophysical Union. All Rights Reserved.

Keywords

  • Arctic oscillation
  • Quasi-Biennial Oscillation
  • planetary waves
  • stratospheric polar vortex
  • the North Pacific center

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