Details

Autor(en) / Beteiligte

• Cai, W.
• Cowan, T.
• Raupach, M.

Titel

Positive Indian Ocean Dipole events precondition southeast Australia bushfires

Ist Teil von

• Geophysical research letters, 2009-10, Vol.36 (19), p.L19710-n/a

Ort / Verlag

Washington, DC: American Geophysical Union

Erscheinungsjahr

2009

Quelle

Wiley Online Library

Beschreibungen/Notizen

• The devastating “Black Saturday” bushfire inferno in the southeast Australian state of Victoria in early February 2009 and the “Ash Wednesday” bushfires in February 1983 were both preceded by a positive Indian Ocean Dipole (pIOD) event. Is there a systematic pIOD linkage beyond these two natural disasters? We show that out of 21 significant bushfires seasons since 1950, 11 were preceded by a pIOD. During Victoria's wet season, particularly spring, a pIOD contributes to lower rainfall and higher temperatures exacerbating the dry conditions and increasing the fuel load leading into summer. Consequently, pIODs are effective in preconditioning Victoria for bushfires, more so than El Niño events, as seen in the impact on soil moisture on interannual time scales and in multi‐decadal changes since the 1950s. Given that the recent increase in pIOD occurrences is consistent with what is expected from global warming, an increased bushfire risk in the future is likely across southeast Australia.