Northern Hemisphere mid-winter vortex-displacement and vortex-split stratospheric sudden warmings: Influence of the Madden-Julian Oscillation and Quasi-Biennial Oscillation

• Published in: Journal of Geophysical Research: Atmospheres
• Main Authors: Liu, Chuanxi, Tian, Baijun, Li, King-Fai, Manney, Gloria L., Livesey, Nathaniel J., Yung, Yuk L., Waliser, Duane E.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: American Geophysical Union 2014
• Subjects: Keywords stratospheric sudden warming; polar vortex; Maddenâ€Julian oscillation; quasiâ€biennial oscillation; planetary wave; teleconnection; Arctic; Indian; Pacific
• Online Access: https://doi.org/10.1002/2014jd021876

We investigate the connection between the equatorial Maddenâ€Julian Oscillation (MJO) and different types of the Northern Hemisphere midâ€winter major stratospheric sudden warmings (SSWs), i.e., vortexâ€displacement and vortexâ€split SSWs. The MJOâ€SSW relationship for vortexâ€split SSWs is stronger than that for vortexâ€displacement SSWs, as a result of the stronger and more coherent eastward propagating MJOs before vortexâ€split SSWs than those before vortexâ€displacement SSWs. Composite analysis indicates that both the intensity and propagation features of MJO may influence the MJOâ€related circulation pattern at high latitudes and the type of SSWs. A pronounced Quasiâ€Biennial Oscillation (QBO) dependence is found for vortexâ€displacement and vortexâ€split SSWs, with vortexâ€displacement (â€split) SSWs occurring preferentially in easterly (westerly) QBO phases. The lagged composites suggest that the MJOâ€related anomalies in the Arctic are very likely initiated when the MJOâ€related convection is active over the equatorial Indian Ocean (around the MJO phase 3). Further analysis suggests that the QBO may modulate the MJOâ€related wave disturbances via its influence on the upper tropospheric subtropical jet. As a result, the MJOâ€related circulation pattern in the Arctic tends to be wave numberâ€one/wave numberâ€two ~25–30 days following phase 3 (i.e., approximately phases 7–8, when the MJOâ€related convection is active over the western Pacific) during easterly/westerly QBO phases, which resembles the circulation pattern associated with vortexâ€displacement/vortexâ€split SSWs. © 2014. American Geophysical Union. Received 6 APR 2014. Accepted 10 OCT 2014. Accepted article online 13 OCT 2014. Published online 28 NOV 2014. This research was supported by the National Science Foundation award ATMâ€0840755 to University of California, Los Angeles. Part of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and ...