African easterly waves, which directly impact communities in Africa, the Caribbean, and the Americas, are shown to intensify during La Niña, advancing our understanding of how these weather systems influence storm activity.
MIAMI— A study led by scientists at the University of Miami Rosenstiel School of Marine, Atmospheric, and Earth Science and the National Center for Atmospheric Research (NCAR) reveals how a major global climate pattern influences the African weather systems that help seed Atlantic hurricanes. The findings, published July 30 in the Journal of Climate, could lead to better seasonal forecasts of rainfall, drought, and tropical cyclone activity across the Atlantic basin.
African easterly waves (AEWs)—atmospheric disturbances that travel across the African continent—play a crucial role in both West African rainfall and the development of most Atlantic hurricanes. The new study shows that the El Niño–Southern Oscillation (ENSO) strongly shapes how these waves behave.
"We found that during La Niña years, AEWs are stronger, moister, and have more thunderstorm activity compared to El Niño years," said Quinton Lawton, a doctoral alumnus of the Rosenstiel School and now a scientist at NCAR. "These seasonal changes could impact local weather patterns and may be another piece of the puzzle in explaining why Atlantic hurricanes are more active during La Niña."
The study began as an undergraduate research project by Brooke Weiser, who developed it into her honors thesis under the advisement of Lawton. Weiser, now an analyst at Moody's Insurance Solutions, collaborated with Lawton and Sharan Majumdar , a professor in the Department of Atmospheric Sciences at the Rosenstiel School. Together, the team analyzed more than four decades of global weather data using an innovative tracking tool called QTrack , developed by Lawton during his doctoral studies at the Rosenstiel School and now widely used by forecasting centers and researchers worldwide.
"Our research presents a detailed climatology of AEWs and their year-to-year variability, allowing us to examine their characteristics and links to climate oscillations with greater precision than before." Weiser said.
"This work highlights the opportunities our undergraduates have to contribute to high-impact meteorological research," said Majumdar. "It's also a great example of graduate-undergraduate mentorship, and collaboration between the Rosenstiel School and NCAR."
By clarifying how ENSO impacts AEWs, the study paves the way to more accurate seasonal predictions that can benefit communities across Africa, the Caribbean, and the Americas. Better forecasts of rainfall, drought, and hurricane risk can give farmers, emergency managers, and residents more time to prepare.
The study titled, "On the Interannual Variability of African Easterly Waves and Its Relationship with the El Niño – Southern Oscillation ," was published on July 30, 2025 in the American Meteorological Society's Journal of Climate
The research was supported by the National Science Foundation (NSF), including an NSF Graduate Research Fellowship, NSF Grants AGS-1747781 and AGS-2438140, and through the NSF cooperative agreement sponsoring NCAR.
About the University of Miami and Rosenstiel School of Marine, Atmospheric and Earth Science
The University of Miami is a private research university and academic health system with a distinct geographic capacity to connect institutions, individuals, and ideas across the hemisphere and around the world. The University's vibrant academic community comprises 12 schools and colleges serving more than 19,000 undergraduate and graduate students in more than 180 majors and programs. Located within one of the most dynamic and multicultural cities in the world, the University is building new bridges across geographic, cultural, and intellectual borders, bringing a passion for scholarly excellence, a spirit of innovation, and a commitment to tackling the challenges facing our world. The University of Miami is a member of the prestigious Association of American Universities (AAU).
Founded in 1943, the Rosenstiel School of Marine, Atmospheric, and Earth Science is one of the world's premier research institutions in the continental United States. The School's basic and applied research programs seek to improve understanding and prediction of Earth's geological, oceanic, and atmospheric systems by focusing on four key pillars:
*Saving lives through better forecasting of extreme weather and seismic events.
*Feeding the world by developing sustainable wild fisheries and aquaculture programs.
*Unlocking ocean secrets through research on climate, weather, energy and medicine.
*Preserving marine species, including endangered sharks and other fish, as well as protecting and restoring threatened coral reefs. www.earth.miami.edu .
