Two-year consecutive concurrences of positive Indian Ocean Dipole and Central Pacific El Niño preconditioned the 2019/2020 Australian “black summer” bushfires

Springer Science and Business Media LLC - Tập 7 Số 1 - 2020
Guojian Wang1, Wenju Cai1
1Key Laboratory of Physical Oceanography–Institute for Advanced Ocean Studies, Ocean University of China and Qingdao National Laboratory for Marine Science and Technology, Yushan Road, Qingdao, 266003, China

Tóm tắt

Abstract The 2019/20 Australian black summer bushfires were particularly severe in many respects, including its early commencement, large spatial coverage, and large number of burning days, preceded by record dry and hot anomalies. Determining whether greenhouse warming has played a role is an important issue. Here, we examine known modes of tropical climate variability that contribute to droughts in Australia to provide a gauge. We find that a two-year consecutive concurrence of the 2018 and 2019 positive Indian Ocean Dipole and the 2018 and 2019 Central Pacific El Niño, with the former affecting Southeast Australia, and the latter influencing eastern and northeastern Australia, may explain many characteristics of the fires. Such consecutive events occurred only once in the observations since 1911. Using two generations of state-of-the-art climate models under historical and a business-as-usual emission scenario, we show that the frequency of such consecutive concurrences increases slightly, but rainfall anomalies during such events are stronger in the future climate, and there are drying trends across Australia. The impact of the stronger rainfall anomalies during such events under drying trends is likely to be exacerbated by greenhouse warming-induced rise in temperatures, making such events in the future even more extreme.

Từ khóa


Tài liệu tham khảo

Ashok K, Guan Z, Yamagata T (2003) Influence of the Indian Ocean dipole on the Australian winter rainfall. Geophys Res Lett 30(15):1821. https://doi.org/10.1029/2003GL017926

Ashok K, Behera SK, Rao SA, Weng H, Yamagata T (2007) El Niño Modoki and its possible teleconnection. J Geophys Res 112:C11007. https://doi.org/10.1029/2006JC003798

Cai W, Cowan T, Raupach M (2009) Positive Indian Ocean dipole events precondition southeast Australia bushfires. Geophys Res Lett 36:L19710. https://doi.org/10.1029/2009GL039902

Cai W, Cowan T, Briggs P, Raupach M (2009) Rising temperature depletes soil moisture and exacerbates severe drought conditions across southeast Australia. Geophys Res Lett 36:L21709. https://doi.org/10.1029/2009GL040334

Cai W, Sullivan A, Cowan T (2010) Interactions of ENSO, the IOD, and the SAM in CMIP3 models. J Clim 24:1688–1704. https://doi.org/10.1175/2010JCLI3744.1

Cai W, van Rensch P, Cowan T, Hendon HH (2011) Teleconnection pathways of ENSO and the IOD and the mechanisms for impacts on Australian rainfall. J Clim 24:3910–3923. https://doi.org/10.1175/2011JCLI4129.1

Cai W, Zheng X-T, Weller E, Collins M, Cowan T, Lengaigne M, Yu W, Yamagata T (2013) Projected response of the Indian Ocean Dipole to greenhouse warming. Nat Geosci 6:999–1007. https://doi.org/10.1038/ngeo2009

Cai W et al (2018) Increased variability of eastern Pacific El Niño under greenhouse warming. Nature 564:201–206. https://doi.org/10.1038/s41586-018-0776-9

Eyring V et al (2016) Overview of the Coupled Model Intercomparison Project Phase 6 (CMIP6) experimental design and organization. Geosci Model Dev 9:1937–1958

Hafeez M, Frost AJ, Vaze J, Smith A, Elmahdi A (2015) A new integrated continental hydrological simulation system: an overview of the Australian Resource Assessment Modelling System (AWRAMS). Water v42:75–82

Hui C, Zheng X-T (2018) Uncertainty in Indian Ocean Dipole response to global warming: the role of internal variability. Clim Dyn 51:3597–3611. https://doi.org/10.1007/s00382-018-4098-2

Min SK, Cai W, Whetton P (2013) Influence of climate variability on seasonal extremes over Australia. J Geophys Res Atmos 118:643–654. https://doi.org/10.1002/jgrd.50164

Nicholls N, Lavery B, Frederiksen C, Drosdowsky W (1996) Recent apparent changes in relationships between the El Niño–Southern Oscillation and Australian rainfall and temperature. Geophys Res Lett 23:3357–3360. https://doi.org/10.1029/96GL03166

Rayner NA et al (2003) Global analyses of sea surface temperature, sea ice, and night marine air temperature since the late nineteenth century. J Geophys Res 108:4407. https://doi.org/10.1029/2002JD002670

Saji NH, Goswami BN, Vinayachandran PN, Yamagata T (1999) A dipole mode in the tropical Indian Ocean. Nature 401:360–363. https://doi.org/10.1038/43854

Shi G, Ribbe J, Cai W, Cowan T (2008) An interpretation of Australian rainfall projections. Geophys Res Lett 35:L02702. https://doi.org/10.1029/2007GL032436

Takahashi K, Montecinos A, Goubanova K, Dewitte B (2011) ENSO regimes: reinterpreting the canonical and Modoki El Niño. Geophys Res Lett 38:L10704. https://doi.org/10.1029/2011GL047364

Taylor KE, Stouffer RJ, Meehl GA (2012) An overview of CMIP5 and the experimental design. Bull Am Met Soc 93:485–498. https://doi.org/10.1175/BAMS-D-11-00094.1

Taschetto AS, England MH (2009) El Niño Modoki impacts on Australian rainfall. J Clim 22:3167–3174. https://doi.org/10.1175/2008JCLI2589.1

Ummenhofer CC et al (2009) What causes southeast Australia’s worst droughts? Geophys Res Lett 36:L04706. https://doi.org/10.1029/2008GL036801

Van Dijk A. (2010) The Australian Water Resources Assessment System. Landscape Model (version 0.5). Technical Report 3. CSIRO. Australia.Van Dijk, A & Warren, G. 2010. The Australian Water Resources Assessment System. Technical Report 4. Landscape Model (version0.5) Evaluation Against. Observations. Technical Report. CSIRO. Australia.

Viney N, Vaze J, Crosbie R, Wang B, Dawes W, Frost A (2015) AWRA-L v5.0: technical description of model algorithms and inputs. CSIRO, Australia

Wang G, Cai W (2013) Climate-change impact on the 20th-century relationship between the Southern Annular Mode and global mean temperature. Sci Rep 3:2039

Wang G, Cai W, Santoso A (2020) Stronger increase in the frequency of extreme convective than extreme warm El Niño events under greenhouse warming. J Clim 33:675–690. https://doi.org/10.1175/JCLI-D-19-0376.1

Wang G, Hendon HH (2007) Sensitivity of Australian rainfall to inter-El Niño variations. J Clim 20:4211–4226. https://doi.org/10.1175/JCLI4228.1

Zelinka MD et al (2020) Causes of higher climate sensitivity in CMIP6 models. Geophys Res Lett 47:e2019L085782

Zheng XT et al (2013) Indian Ocean Dipole response to global warming in the CMIP5 multimodel ensemble. J Clim 26:6067–6080. https://doi.org/10.1175/JCLI-D-12-00638.1

Thông tin
Thông tin xuất bản

Springer Science and Business Media LLC

Tập 7 Số 1

Thông tin tác giả