Khalifa University research team says decoding the mechanics of atmospheric rivers will help mitigate their impacts in a warming world.听
In April 2023, flash flooding hit cities and villages in the Middle East, claiming lives, destroying homes and leaving hundreds displaced. A team of researchers from Khalifa University has investigated the cause of this sudden downpour and found an atmospheric river was to blame.听听
The team published their research in .听听
Atmospheric rivers are narrow bands of concentrated water vapor on a global scale, transporting vast quantities of moisture from the tropics to the poles. They bring life-sustaining rainfall to drier regions, but wield the destructive potential to trigger catastrophic floods in mid- and high-latitudes. As climate change accelerates, ARs are becoming not only more frequent but also more intense, raising profound concerns about their future impacts.听听
Dr. Diana Francis, Dr. Ricardo Fonseca and Dr. Narendra Nelli from the Khalifa University Environmental and Geophysical Sciences Lab (ENGEOS) examined atmospheric river rapids and their role in the extreme rainfall event of April with Deniz Bozkurt, Universidad de Valpara铆so, Chile and Bin Guan, UCLA. This unprecedented event struck the Middle East, wreaking havoc and underscoring the capacity of ARs to inflict substantial damage in regions ill-prepared for such meteorological events.听听
“Our research into the devastating flooding in the Middle East in 2023 has uncovered fast-moving AR rapids within atmospheric rivers. As these systems grow more frequent with climate change, understanding them is crucial for future weather preparedness.”
鈥� Dr. Diana Francis, Assistant Professor of Earth Science, KU
鈥淎Rs in the Middle East are more frequent and the strongest in March, when about 23 percent of all ARs take place, and least frequent and weakest in November,鈥� Dr. Francis explained. 鈥淭hey tend to be less intense in the Middle East, due to the aridity of surrounding areas, but even though the precipitation can be beneficial in drier subtropical regions and during drought periods, ARs can deliver life-threatening amounts of rainfall.鈥澨�
More specifically, the research team found this event was caused by atmospheric river rapids, where the flow of water in the atmosphere was constricted by steep gradients of temperature or pressure, forcing more water vapor to pass through an area than normal. These rapids tend to be indistinguishable within much larger atmospheric rivers and forecasting models struggle to identify them.听听
鈥淰ery few studies have delved into the finer structure of the water movement within an AR such as AR rapids,鈥� Dr. Francis said. 鈥淥ur findings pave the way for new research and investigation avenues. For example, are AR rapid-like structures present in all ARs or just in specific ones? Moving forward, research needs to delve deeper into the dynamics behind ARs and investigate their seasonality and variability.鈥澨�
The research team says these questions can be addressed by modeling a large number of individual events and that dedicated field observations will be crucial to develop a forecasting model and scale for AR rapids. They hope that this research will help deliver an operational model to mitigate their potential devastating impacts.听听
鈥淲e expect that ARs will become more frequent and intense in a warming climate, including here in the Middle East, so understanding their dynamics in the present climate will help us better predict their changes in the future,鈥� Dr. Francis said.听
Jade Sterling听
Science Writer
22 October 2024
