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Asymmetry in the response of eastern Australia extreme rainfall to low‐frequency Pacific variability
Author(s) -
King Andrew D.,
Alexander Lisa V.,
Donat Markus G.
Publication year - 2013
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/grl.50427
Subject(s) - climatology , precipitation , pacific decadal oscillation , environmental science , flooding (psychology) , magnitude (astronomy) , divergence (linguistics) , extreme value theory , geology , atmospheric sciences , el niño southern oscillation , geography , meteorology , mathematics , physics , statistics , psychology , linguistics , philosophy , astronomy , psychotherapist
This study investigates relationships between variability in the Pacific and extreme rainfall in eastern Australia. Using an index of extreme precipitation derived from a daily gridded precipitation data set from 1900 to 2011, we find that a nonlinear relationship between El Niño–Southern Oscillation and extreme rainfall exists. That is, the strength of a La Niña episode has a much greater influence on the intensity and duration of extreme rainfall than the magnitude of an El Niño episode. This relationship is found in both interpolated observations and reanalysis data and may be explained, in part, by shifts in the divergence of moisture flux. There is significant decadal variability in the relationship, such that the asymmetry is enhanced during Interdecadal Pacific Oscillation (IPO)–negative events and is nonexistent during IPO‐positive phases. This information has the potential to be of great use in the seasonal prediction of intense rainfall events that lead to flooding.