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Modeling Evidence of QBO‐MJO Connection: A Case Study
Author(s) -
Back SeungYoon,
Han JiYoung,
Son SeokWoo
Publication year - 2020
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 - 10.1029/2020gl089480
Subject(s) - madden–julian oscillation , climatology , outgoing longwave radiation , precipitation , environmental science , mesoscale meteorology , oscillation (cell signaling) , atmospheric sciences , zonal and meridional , weather research and forecasting model , geology , meteorology , physics , convection , biology , genetics
The boreal winter Madden‐Julian Oscillation (MJO) is modulated by the Quasi‐Biennial Oscillation (QBO). The MJO becomes relatively strong during the easterly QBO (EQBO) winters but weak during the westerly QBO (WQBO) winters. To better understand their relationship, a set of WRF model experiments is conducted with varying lateral boundary conditions. The MJO event in December 2007, during EQBO winter, is chosen as a reference case. The control experiment qualitatively reproduces the observed MJO. When the lateral boundary conditions are switched with those of WQBO or strong WQBO winters, the MJO becomes weak over the Maritime Continent. All eight ensemble members exhibit enhanced outgoing longwave radiation and reduced precipitation from EQBO to WQBO, and to strong WQBO conditions, although the magnitude of changes is smaller than observations. This result, one of the first mesoscale modeling evidences of the QBO‐MJO connection, suggests that the MJO is at least partly modulated by the QBO.