气候变化领域集成服务门户(CCPortal): Tropical forcing of Australian extreme low minimum temperatures in September 2019

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DOI	10.1007/s00382-021-05661-8
	Tropical forcing of Australian extreme low minimum temperatures in September 2019
	Lim E.-P.; Hendon H.H.; Shi L.; de Burgh-Day C.; Hudson D.; King A.; Trewin B.; Griffiths M.; Marshall A.
发表日期	2021
ISSN	0930-7575
起始页码	1783
结束页码	1797
卷号	56 期号:2021-11-12
英文摘要	We explore the causes and predictability of extreme low minimum temperatures (Tmin) that occurred across northern and eastern Australia in September 2019. Historically, reduced Tmin is related to the occurrence of a positive Indian Ocean Dipole (IOD) and central Pacific El Niño. Positive IOD events tend to locate an anomalous anticyclone over the Great Australian Bight, therefore inducing cold advection across eastern Australia. Positive IOD and central Pacific El Niño also reduce cloud cover over northern and eastern Australia, thus enhancing radiative cooling at night-time. During September 2019, the IOD and central Pacific El Niño were strongly positive, and so the observed Tmin anomalies are well reconstructed based on their historical relationships with the IOD and central Pacific El Niño. This implies that September 2019 Tmin anomalies should have been predictable at least 1–2 months in advance. However, even at zero lead time the Bureau of Metereorolgy ACCESS-S1 seasonal prediction model failed to predict the anomalous anticyclone in the Bight and the cold anomalies in the east. Analysis of hindcasts for 1990–2012 indicates that the model's teleconnections from the IOD are systematically weaker than the observed, which likely stems from mean state biases in sea surface temperature and rainfall in the tropical Indian and western Pacific Oceans. Together with this weak IOD teleconnection, forecasts for earlier-than-observed onset of the negative Southern Annular Mode following the strong polar stratospheric warming that occurred in late August 2019 may have contributed to the Tmin forecast bust over Australia for September 2019. © 2021, Crown.
英文关键词	Extremes; Predictability; Teleconnections
来源期刊	Climate Dynamics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/183245
作者单位	Bureau of Meteorology, Melbourne, VIC, Australia; School of Earth Sciences, ARC Centre of Excellence for Climate Extremes, University of Melbourne, Parkville, VIC, Australia
推荐引用方式 GB/T 7714	Lim E.-P.,Hendon H.H.,Shi L.,et al. Tropical forcing of Australian extreme low minimum temperatures in September 2019[J],2021,56(2021-11-12).
APA	Lim E.-P..,Hendon H.H..,Shi L..,de Burgh-Day C..,Hudson D..,...&Marshall A..(2021).Tropical forcing of Australian extreme low minimum temperatures in September 2019.Climate Dynamics,56(2021-11-12).
MLA	Lim E.-P.,et al."Tropical forcing of Australian extreme low minimum temperatures in September 2019".Climate Dynamics 56.2021-11-12(2021).