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ENSO, the IOD and the intraseasonal prediction of heat extremes across Australia using POAMA-2
journal contribution
posted on 2023-05-17, 23:22 authored by Christopher White, Hudson, D, Alves, OThe simulation and prediction of extreme heat over Australia on intraseasonal timescales in association with the El Nino–Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD) is assessed using the Bureau of Meteorology’s Predictive Ocean Atmosphere Model for Australia (POAMA). The analysis is based on hindcasts over 1981–2010 and focuses on weeks 2 and 3 of the forecasts, i.e. beyond a typical weather forecast. POAMA simulates the observed increased probabilities of extreme heat during El Nino events, focussed over south eastern and southern Australia in SON and over northern Australia in DJF, and the decreased probabilities of extreme heat during La Nina events, although the magnitude of these relationships is smaller than observed. POAMA also captures the signal of increased probabilities of extreme heat during positive phases of the IOD across southern Australia in SON and over Western Australia in JJA, but again underestimates the strength of the relationship. Shortcomings in the simulation of extreme heat in association with ENSO and the IOD over southern Australia may be linked to deficiencies in the teleconnection with Indian Ocean SSTs. Forecast skill for intraseasonal episodes of extreme heat is assessed using the Symmetric Extremal Dependence Index. Skill is highest over northern Australia in MAM and JJA and over south-eastern and eastern Australia in JJA and SON, whereas skill is generally poor over south-west Western Australia. Results show there are windows of forecast opportunity related to the state of ENSO and the IOD, where the skill in predicting extreme temperatures over certain regions is increased.
History
Publication title
Climate DynamicsVolume
43Issue
7-8Pagination
1791-1810ISSN
0930-7575Department/School
School of EngineeringPublisher
SpringerPlace of publication
Heidelberg, GermanyRights statement
Copyright 2013 Springer-Verlag Berlin HeidelbergRepository Status
- Restricted