Impact of cold surges on the Madden-Julian oscillation propagation over the Maritime Continent

Whether the Madden-Julian oscillation (MJO) propagates into the western Pacific or is blocked by the Maritime Continent (MC) can have great impacts on global weather and climate. This study investigates the extratropical circulations associated with the MJO events that propagate across the MC (MJO-C) and those blocked by the MC (MJO-B), respectively, during the boreal winter. The results show that there are significant northeasterly anomalies over the South China Sea and tropical western North Pacific when MJO-C events propagate through the MC. The MJO-C events are much more likely to be accompanied by cold surges during its propagation over the MC, following the intensification of the Siberian High. This study suggests that cold surges, which have been documented as a trigger of tropical convection, can help the MJO propagate across the MC.