The two‐way relationship between the Madden–Julian oscillation and anticyclonic wave breaking

Abstract

The Madden– Julian oscillation (MJO) is the primary mode of intraseasonal variability in the Tropics. The MJO often couples with convection as it moves over the Indian Ocean and decouples as it leaves the west Pacific Ocean. The association between convection coupled to the MJO and the midlatitude flow pattern has been the primary focus of numerous studies. In particular, it has been shown that there is a statistical relationship between the position and strength of the MJO and anticyclonic wave breaking (AWB). This study expands on this statistical relationship by examining the two‐way relationship between the MJO and AWB.Using a climatology of AWB during an extended boreal cold season, we demonstrate that there is enhanced AWB over the central North Pacific when active MJO convection is over the eastern Indian Ocean and Maritime Continent. Convection associated with the MJO can induce AWB when active MJO convection is over the Indian Ocean. Once the wave breaks over the central North Pacific, the residual cut‐off low phases with the MJO circulation to enhance it as it propagates eastward, resulting in a higher amplitude MJO than when no AWB occurs.