New research from the University of 91直播 at Manoa could help weather forecasters better predict periods of rainfall, such as the heavy storms the islands have experienced in recent months.
The research focuses on a weather phenomenon known as the Madden-Julian Oscillation (MJO), which moves eastward through the tropics every 30 to 60 days, according to a press release from UH Manoa.
The MJO cycles between different phases, bringing increased rainfall during some and dryer weather during others. The new research revealed just how closely linked those phases are to rainfall in 91直播.
While the existence of this phenomenon has been known for decades, its impact on the 91直播an Islands, specifically in terms of rainfall variability over the course of one to three months, had not previously been studied in depth.
Audrey Nash, a Ph.D. candidate at the School of Earth Science and Technology, and associate professor Giuseppe Torri conducted the research.
“Understanding how the MJO affects 91直播’s climate helps explain rainfall variability on timescales of weeks to months,” Nash said in the press release. “The MJO evolves slowly and can be monitored in real time. Understanding its influence can help scientists and forecasters better anticipate periods of heavy rainfall, drought conditions, and shifts in weather patterns across the islands.”
One of these forecasters, Robert Ballard, a science and operations officer for the National Weather Service in Honolulu, agrees.
“There are many oscillations in the deep tropics that occur that can modulate the weather, not just in 91直播 but globally, and this is one of the ones that’s important to our weather locally,” he said.
While he acknowledged that weather is complex with many contributing factors, he sees this research as a valuable tool for more accurate and reliable future forecasts.
“All of these things sort of work together in a complex puzzle, and this is one piece of the puzzle that hasn’t really been researched very much for 91直播, and this is what they were trying to get at,” he said. “Weather forecasting is a step by step process where we get better and better as we learn new things, and this is a big step forward toward improving those forecasts in that weeks to months time frame.”
The research could be particularly relevant for the Big Island, especially places like Hilo, located on the rainier windward side.
“A couple of (Nash’s) figures in the paper actually show that some of the strongest rainfall anomalies, as modulated by the MJO, are along the windward side of the Big Island,” Ballard said. “Some of the strongest rainfall anomalies, either wet or dry, are near and upslope from Hilo, so windward Big Island tends to see that.”
Beyond improving forecasts, the researchers hope their work will have practical implications for residents across the islands.
“Improving our understanding of rainfall variability is critical for water management, agriculture, and hazard preparedness,” said Nash in the press release. “This work reflects the University of 91直播’s mission to study the unique environmental systems that shape life in the islands and to provide science that benefits local communities.”
Ballard said he believes this work provides an important foundation for better understanding weather in 91直播.
“It definitely opens the door for more research,” he said. “This is, I think, just the beginning.”
Email Grace Inez Adams at grace.adams@hawaiitribune-herald.com.
