Modulation of the MJO and North Pacific Storm Track Relationship by the QBO

Abstract This study demonstrates a possible impact of the quasi‐biennial oscillation (QBO) on the Madden‐Julian Oscillation (MJO)‐related North Pacific storm track (NPST) change during October–March for the period of 1979–2016. The NPST shows significant intraseasonal changes in response to the MJO. In general, when the MJO convection is located over the Indian Ocean (western to central Pacific), the NPST tends to shift poleward (southward). This MJO‐related NPST change has larger amplitude during the easterly phase of the QBO (EQBO) than during its westerly phase (WQBO). The spatial distribution of this NPST change also exhibits significant differences between the two QBO phases with a zonally elongated pattern during EQBO winters but separated into two centers during WQBO winters. Diagnoses of the dynamical processes associated with the NPST change indicate the dominant roles of the ba…