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Modulation of the boreal wintertime Madden‐Julian oscillation by the stratospheric quasi‐biennial oscillation
Author(s) -
Yoo Changhyun,
Son SeokWoo
Publication year - 2016
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2016gl067762
Subject(s) - madden–julian oscillation , stratosphere , quasi biennial oscillation , climatology , troposphere , atmospheric sciences , environmental science , oscillation (cell signaling) , boreal , forcing (mathematics) , convection , geology , meteorology , physics , genetics , paleontology , biology
Madden‐Julian oscillation (MJO), the dominant mode of intraseasonal variability in the tropical troposphere, has a significant impact on global weather and climate. Here we present that the year‐to‐year variation of the MJO activity shows significant changes with the quasi‐biennial oscillation (QBO) in the tropical stratosphere. Specifically, the boreal winter MJO amplitude, evaluated by various metrics, is typically stronger than normal during the QBO easterly phase at 50 hPa and weaker than normal during the QBO westerly phase at 50 hPa. This relationship, which is possibly mediated by the QBO‐related static stability and/or vertical wind shear changes in the tropical upper troposphere and lower stratosphere, is robust whether or not the activeness of the MJO or QBO is taken into account. This result suggests a new potential route from the stratosphere that regulates the organized tropical convection, helping to improve the prediction skill of the boreal winter MJO.