The modulation of tropical cyclone activity in the Australian region by the Madden-Julian oscillation

Abstract

The observed relationship between tropical cyclone activity in the Australian region and the Madden-Julian oscillation (MJO) has been examined using 20 yr of outgoing longwave radiation, NCEP-NCAR reanalysis, and best track tropical cyclone data. The MJO strongly modulates the climatological pattern of cyclogenesis in the Australian region, where significantly more (fewer) cyclones form in the active (inactive) phase of the MJO. This modulation is more pronounced to the northwest of Australia. The relationship between tropical cyclone activity and the MJO was strengthened during El Nino periods. Variations of the large-scale dynamical conditions necessary for cyclogenesis were explored, and ..