Flash drought is a recently defined type of extreme climate phenomenon characterized by sudden onset and rapid enhancement of drought conditions, which may have severe effects on agriculture and natural vegetation. Australia is the driest continent in the world, with more than 80% of the country’s average annual rainfall below 600 mm. Drought is one of Australia’s major agricultural problems, affecting food production, farmers’ living conditions and expending billions of dollars in government aid.
Dr. Hanh Nguyen, Dr. Matthew Wheeler, Dr. Harry Hendon, Dr. Harry Hendon, Dr. Eun-Pa Lim of the Melbourne Meteorological Agency, Australia, and Dr. Jason Otkin of the University of Wisconsin-Madison conducted a study on flash drought in the 2019 Australian subtropical eastern The evolution of the situation and linear regression was performed using global climate drivers to study aspects of its predictability. The paper was published in Extreme weather and climate Diary in June this year.
Dr. Nguyen and Colleagues focus on Australians Embedded flash drought occurred during the drought period from 2017 to 2019. “This multi-year drought in many parts of Australia is the driest and hottest triennium since 1911 due to heavy precipitation. During the period 2017-2019, we objectively identified it as a rapid flash drought After the strengthening, the impact of drought increased to the worst in 2019,” added Dr. Nguyen. To monitor the progress of point-by-point drought and define the occurrence of flash droughts, the team used the evaporative stress index (ESI) and performed multiple linear regressions using ESI to draw conclusions to predict the extent of flash droughts.
The authors examined the progress of ESI flash drought, reflecting the combined effect of many factors that may lead to vegetation stress, such as lack of moisture in the soil and increased evaporation. “Using ESI to monitor drought conditions allows us to identify and fully characterize flash drought events in terms of time, span and severity, and based on ESI and its relationship with climate drivers, we understand that 2019 is not a completely unexpected drought. ,” said Dr. Nguyen. After weeks of rapid drought enhancement, the consolidation effects of the near-record strong positive frontal Indian Ocean dipole dipole dipole mode (Solid Central Pacific Elniño Modoki near-record strong negative Southern Ring mode) contributed to the rapid drought for several weeks. Intensify, while the intensity of drought has expanded to extremes.
The team then suggested that the strong Indian Ocean dipole dipole mode, El Nino Modocchi and the strong negative Southern Ring mode occur simultaneously, providing a certain degree of predictability for the occurrence and worsening of flash droughts. “However, while predicting climate regimes over weeks of advance time through statistical and dynamic methods, predicting the exact timing and location of flash drought will require more local and current information than such major climate factors, which will require more Initial atmospheric conditions for local and current information dynamic models,” said Dr. Nguyen. Dr. Nguyen and colleagues’ research also investigated the predictability of flash drought using the Australian Community Climate and Earth Systems Simulator Season V1.0 (Access-S1) model. The results of this extensive study will guide future research on the predictability of flash drought.
Journal Reference and main image credit:
Nguyen, H., Wheeler, MC, Hendon, HH, Lim, EP and Otkin, JA, JA, 2021. Flash Dright’s flash drought in Australia’s subtropical regions in 2019 and its association with large-scale climate drivers. Extreme weather and climate,,,,, 32. doi: https://doi.org/10.1016/j.wace.2021.100321
About the Author
Dr. Hanh Nguyen
Dr. Hanh Nguyen is a senior climate scientist with the Australian Meteorological Agency. She completed her PhD on the variability of weather rainfall in equatorial Africa and its connection to the equatorially coupled kelvin waves at the University of Pierre in Paris, France and the University of Mary Curry. Her research interests include the science of tropical climate change and climate change, drought and seasonal climate prediction. Dr. Hanh Nguyen currently works on Flash Drights as part of the Northern Australia Climate Program (NACP). Her team is the first to be released on Flash Drugs in Australia in 2019. Her publication records can be accessed via ResearchGate or Google Scholar.
