The influence of the stratospheric quasi-biennial oscillation on the
tropical easterly jet over the Maritime Continent
This study investigated the influence of the stratospheric
quasi-biennial oscillation (QBO) on the tropical easterly jet (TEJ).
Easterly (EQBO) and westerly (WQBO) phases of the QBO are defined based
on the 50 hPa zonal wind. The climatological rising movement on the west
side of the Maritime Continent can reach higher altitude than that on
the east side, which makes the convection on the west side more
effectively promoted by the reduced stability near the tropopause during
EQBO. Compared with WQBO, during EQBO, the convection on the west (east)
side of the Maritime Continent is enhanced (weakened), and there is a
stronger (weaker) divergence in the upper troposphere. Corresponding to
the change of the divergence field, the TEJ over the Maritime Continent
during EQBO is significantly weakened than WQBO, and the magnitude of
the change can reach 11% of the climatological TEJ.