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Kodera, K., T. Nasuno, S.-W. Son, N. Eguchi and Y. Harada, 2023: Influence of the stratospheric QBO on seasonal migration of the convective center across the Maritime Continent. J. Meteor. Soc. Japan, 101.
https://doi.org/10.2151/jmsj.2023-026
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Plain Language Summary: A marked impact of the stratospheric quasi-biennial oscillation (QBO) on the Madden–Julian Oscillation (MJO) has become evident in recent studies. In this study, we show that the QBO affects the annually phase-locked seasonal migration of the tropical convection from the equatorial Indian Ocean to the Western Pacific in the Austral summer: large-scale convection strengthens and moves eastward more effectively during easterly phase of the QBO (QBO‒E) in austral summers than that during westerly phase of the (QBO‒W).

Highlights:

• We propose a hypothesis on the sub-seasonal process: the anomalous cooling around the tropopause associated with Kelvin wave-like response under QBO‒E produces a favorable condition for a development of penetrating convection into the tropical tropopause layer over the eastern MC compare to that under QBO‒W, which promotes the seasonal migration of convection.
• The implication of this process for the QBO modulation of the MJO crossing the MC is also discussed.