Flash droughts are a type of recently defined extreme climate phenomenon characterized by the sudden onset and the rapid intensification of drought conditions, which may have serious consequences on agriculture and natural vegetation. Australia is the driest continent worldwide, with more than 80% of the country that has an average annual precipitation of less than 600 mm. Drought is one of Australia’s main agricultural problems, which affect food production, farmers’ living conditions and that cost the government billions of dollars in help.
Dr. Hanh Nguyen, Dr. Matthew Wheeler, Dr. Harry Hendon, Dr. Eun-Pa Lim in the Meteorology Office, Melbourne, Australia, in collaboration with Dr. Jason Otkin, of the University of Wisconsin-Madison, conducted a study on the evolution of Flash artillery conditions. The article was published in the Climate climate and extremes Magazine in June this year.
Dr. Nguyen and colleagues focused on the Australian 2017-2019 drought period with integrated flash droughts. “This drought of several years in many parts of Australia was the period of 3 years dry and hot since 1911 due to a massive precipitation deficit. During 2017-2019, drought impacts increased to be more severe in 2019 after several quick intensification episodes that we have objectively identified as a Flash drought,” Dr. Nguyen added. To monitor the advance of the drought point by point and define the events of the flash drought, the equipment uses the evaporative stress index (ESI), and multiple linear regression with the ESI is used to make conclusions to the extent that the flash drought can be predicted.
The authors investigated the progression of the Flash drought by the ESI, which reflects the combined effects of many factors that can lead to the stress of vegetation, such as the lack of moisture in the soil and high evaporative demand. “The monitoring of drought conditions, the use of ESI, allows us to identify and completely characterize the flash drought events in terms of time, section and gravity, and based on the ESI and its relationship with climatic drivers, we have learned that 2019 is not a completely unexpected drought,” said Dr. Nguyen. The intensity of the drought expanded to be extreme in 2019 after a few weeks of rapid drought intensification foster by the consolidated impacts of the Postitive Indian Ocean Dipolo mode, a solid diproll mode, the Solid Central Pacific Modeki, a higher negative negative annular mode.
Then, the research team suggested that the simultaneous occurrence of the Dipolo mode of the strong and strong Indian Ocean, the child modeki and the strong southern annular mode provided a certain degree of predictability in the occurrence and worsening of the Flash drought. “However, although climate regimes are mostly predicted in several weeks of delivery time by statistical and dynamic methods, predict the exact moment and the location of a Flash drought will require more local and current information than the important climatic factors, as can provide the initial atmospheric conditions for a dynamic model,” said Dr. Nguyen. Dr. Nguyen’s research and his colleagues also examine the predictability of Flash droughts using the Australian community climate model and V1.0 seasonal land systems simulator (Access-S1). The results of this extensive research will guide future studies on the predictability of Flash drought.
Diary reference and main image credit:
Nguyen, H., Wheeler, MC, Hendon, HH, Lim, EP and Otkin, Ja, 2021. The 2019 Flash droughts in Australia of the Subtropical East and its association with large -scale climatic conductors. Climate climate and extremes, 32. DOI: https://doi.org/10.1016/j.wace.2021.100321
About the author
Dr. Hanh Nguyen, Ph.D.
Dr. Hanh Nguyen is a senior climate scientist from the Meteorology Office, Australia. She completed her Ph.D. On the variability of the synoptic rain of Equatorial Africa and its link with the convectial coupled Kelvin waves at the Pierre and Marie Curie University in Paris, France. Their research interests include tropical climatic variability and climate change, drought science and seasonal climatic prediction. Dr. Hanh Nguyen currently works in Flash droughts as part of the climate program of Northern Australia (NACP). His team was the first to publish in Flash droughts about Australia in 2019. You can access your publication registration through Researcher either Google Scholar.
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