Two UW–Madison professors named MacArthur Fellows

Atmospheric scientist Ángel F. Adames Corraliza and nuclear security specialist Sébastien Philippe, professors at the University of Wisconsin-Madison, have been awarded 2025 MacArthur Fellowships.

Often referred to as "genius grants," the fellowships are presented by the John D. and Catherine T. MacArthur Foundation to individuals based on their exceptional creativity, dedication to their pursuits and the potential for their work to benefit society - especially with additional support. Fellows receive $800,000 granted with no conditions.

"I'm thrilled for both Ángel and Sébastien, both of whom are doing such ambitious work on truly important issues: in one case, understanding the atmospheric conditions in the tropics, and in the other, understanding how we can reduce the risk of nuclear war and nuclear weapons," says UW-Madison Chancellor Jennifer L. Mnookin. "They are both powerful examples of the kind of creative thinkers that make UW-Madison such a rich and creative research environment, and wonderful additions to our university's proud tradition of winners of this prestigious fellowship."

Ángel F. Adames Corraliza

Adames Corraliza, associate professor in the Department of Atmospheric and Oceanic Sciences and Ned P. Smith Distinguished Chair of Climatology, joined the UW-Madison faculty in 2020 after several years at the University of Michigan and as a scientist at the National Oceanic and Atmospheric Administration.

The MacArthur Foundation cited his advances in quantifying the role of moisture in tropical weather and climate, bringing us closer to a full understanding of the atmosphere in the tropics. That's important, according to Adames Corraliza, because despite serving as home to nearly half the global population, the region near the equator has not received the same scientific scrutiny as other latitudes. As a result, weather and climate forecasts in the tropics are less accurate, to the detriment of the people who live there.

"The tropics receive so much more sunlight than the rest of Earth," he says. "They have an excess of energy that they donate to the mid-latitudes, and the way they export that energy is through clouds - convection and big systems that rain a lot, like thunderstorms and hurricanes."

Just how conditions - like humidity, temperature and wind - give rise to those clouds and how the clouds then influence conditions on larger scales is the focus of Adames Corraliza's research.

"There's this intricate dance, a two-way street interaction between how the environment sets the clouds, and then how the clouds communicate back to the environment and tell it how it should evolve," he says. "I want to understand that dance."

Sébastien Philippe

Philippe became an assistant professor in the Department of Nuclear Engineering and Engineering Physics this fall after time as a research scholar at Princeton University and as a nuclear security expert with the French Ministry of Defense. Working at the intersection of science, engineering and public policy, his aim is to reduce the risk associated with nuclear weapons.

The MacArthur Foundation noted the multidisciplinary nature of Philippe's studies of the environmental impact of nuclear weapons tests by France and the United States. The investigations combined declassified documents, historical weather reports and atmospheric modeling to show far more people in French Polynesia and New Mexico and Nevada were exposed to radiation than acknowledged in official records. The results have changed policy and the way people affected are compensated.

Today, he says, his research is more forward-looking, as the number of nuclear weapons in the world is starting to increase again. In August, Philippe was appointed to a United Nations panel charged with producing a report on the consequences of nuclear war at local, regional and global scales. It will be the first such UN report in 40 years.

"I've started applying my modeling tools and bringing together collaborators to better understand the consequences of nuclear weapon use and of nuclear war today," Philippe says. "We want to see how those findings could influence domestic policy on nuclear weapons, strategies, deployments and modernization, and also inform international diplomacy on those issues."

While they come from very different fields, the scientists have similar hopes for how the high-profile MacArthur award can advance their work - and the work of others.

"I see this as an investment in the future and support for freedom of inquiry and creativity and collaboration on some sensitive issues," says Philippe. "It gives you freedom to explore avenues that would not otherwise be easy to pursue."

"Coming from Puerto Rico, I feel that, as a bloc of scientists and people, we have gone through a lot of struggles," Adames Corraliza says. "Even with all these struggles, there's so much talent, so much we can give. This recognition makes us more visible."