Journal article
Why Australia was not wet during spring 2020 despite La Niña
EP Lim, D Hudson, MC Wheeler, AG Marshall, A King, H Zhu, HH Hendon, C de Burgh-Day, B Trewin, M Griffiths, A Ramchurn, G Young
Scientific Reports | Published : 2021
Abstract
The austral spring climate of 2020 was characterised by the occurrence of La Niña, which is the most predictable climate driver of Australian springtime rainfall. Consistent with this La Niña, the Bureau of Meteorology’s dynamical sub-seasonal to seasonal forecast system, ACCESS-S1, made highly confident predictions of wetter-than-normal conditions over central and eastern Australia for spring when initialised in July 2020 and thereafter. However, many areas of Australia received near average to severely below average rainfall, particularly during November. Possible causes of the deviation of rainfall from its historical response to La Niña and causes of the forecast error are explored with ..
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Awarded by Centre of Excellence for Environmental Decisions, Australian Research Council
Funding Acknowledgements
This study is part of the Forewarned is Forearmed project, which is supported by funding from the Australian Government Department of Agriculture, Water and the Environment as part of its Rural R&D for Profit programme. H. Zhu received funding from the Australian Government's National Environmental Science Programme (NESP), and A. King received funding from the Australian Research Council (DE180100638). C. de Burgh-Day and M. Wheeler received support from the Northern Australian Climate Program (NACP) funded by Meat and Livestock Australia, the Queensland Government, and University of Southern Queensland. We are grateful to Dr Sugata Narsey at the BoM for his feedback on the initial version of the manuscript. We thank Dr Oscar Alves and other members of the seasonal prediction teams at the BoM for their work in the generation and curation of the ACCESS-S1 hindcast set. E. Lim thanks Ms Alison Griffiths for her input to the title of this article. This research was undertaken on the NCI National Facility in Canberra, Australia, which is supported by the Australian Commonwealth Government. The NCAR Command Language (NCL; http://www.ncl.ucar.edu) version 6.4.0, IDL version 8.7.3, and Python version 3.6.1 were used for data analysis and visualization of the results. We also acknowledge NCAR/UCAR, NOAA, the Japanese Meteorological Agency, and the BoM for producing and providing the Hurrell et al. (2008) SST analysis, the OLR data, the JRA-55 reanalysis, and the MJO RMM data, respectively, and Henley et al.63 and NOAA for the availability of the IPO Tripole Index. Finally, we thank Dr Shuhei Masuda for convening the peer-review process and two anonymous reviewers for their valuable feedback on the manuscript.