Revisiting ENSO and IOD Contributions to Australian Precipitation

Giovanni Liguori, Shayne McGregor, Martin Singh, Julie Arblaster, Emanuele Di Lorenzo

Research output: Contribution to journalArticleResearchpeer-review

12 Citations (Scopus)

Abstract

Tropical modes of variability, such as El Niño–Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD), exert a strong influence on the interannual variability of Australian precipitation. Nevertheless, commonly used indices of ENSO and IOD variability display significant co-variability that prevents a robust quantification of the independent contribution of each mode to precipitation anomalies. This co-variability issue is often addressed by statistically removing ENSO or IOD variability from the precipitation field before calculating teleconnection patterns. However, by performing a suite of coupled and uncoupled modeling experiments in which either ENSO or IOD variability is physically removed, we show that ENSO-only-driven precipitation patterns computed by statistically removing the IOD influence significantly underestimate the impact of ENSO on Australian precipitation variability. Inspired by this, we propose a conceptual model that allows one to effectively separate the contribution of each mode to Australian precipitation variability.

Original languageEnglish
Article numbere2021GL094295
Number of pages12
JournalGeophysical Research Letters
Volume49
Issue number1
DOIs
Publication statusPublished - 16 Jan 2022

Keywords

  • Australian precipitation
  • CESM
  • ENSO
  • IOD
  • partial regression analysis
  • SST nudging

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