The Modulation of Tropical Cyclone Activity in the Australian Region by the Madden–Julian Oscillation

Jonty D. Hall, Adrian J. Matthews, David J. Karoly

Research output: Contribution to journalArticlepeer-review

188 Citations (Scopus)

Abstract

The observed relationship between tropical cyclone activity in the Australian region and the Madden-Julian Oscillation (MJO) has been examined using 20 years 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 north-west of Australia. The relationship between tropical cyclone activity and the MJO was strengthened during El Nino periods. Variation of the large-scale dynamical conditions necessary for cyclogenesis were explored, and it was found that MJO-induced perturbations of these parameters correspond with the observed variation in cyclone activity. In particular, 850-hPa relative vorticity anomalies attributable to the MJO were found to be an excellent diagnostic of the changes in the large-scale cyclogenesis patterns.
Original languageEnglish
Pages (from-to)2970-2982
Number of pages13
JournalMonthly Weather Review
Volume129
Issue number12
DOIs
Publication statusPublished - 2001

Cite this