New Department Chairs Announced: Mathematics and Atmospheric Science

Gannet Hallar

Accomplished researcher, Storm Peak director, and dedicated mentor takes the helm of the Department of Atmospheric Sciences effective July 1, succeeding outgoing chair Brenda Bowen.

Gannet Hallar has spent nearly two decades with her head in the clouds—literally. As director of Storm Peak Laboratory, the premier high-elevation atmospheric science research station in the Western United States, perched atop Steamboat Springs Ski Resort in Colorado at 10,500 feet, she has built one of the most productive field research programs in the discipline.

Now, the University of Utah professor brings that same energy and vision to her new role as Chair of the Department of Atmospheric Sciences in the College of Science, effective July 1, succeeding outgoing chair Brenda Bowen.

Sampling clouds

"The laboratory sits in the clouds about 40% of the time in the winter," Hallar says of Storm Peak. "That allows us to sample clouds and the particles that make clouds at the same time. And from that, the lab has produced about 160 peer-reviewed publications."

That record reflects the sweep of her research program and a nod to her reputation as an exceptional teacher and mentor. The 3,500-square-foot facility, funded by the National Science Foundation and operated under a U.S. Forest Service permit, allows her team to collect high-quality measurements of trace gases, aerosol physical and chemical properties, and cloud microphysics to understand connections between the biosphere, atmosphere, and climate. The NSF has formally recognized Storm Peak as a Community Instruments and Facilities (CIF) site for the atmospheric sciences. More recently, Hallar’s research group has installed aerosol measurements across ski resorts in Utah including Snowbird, Snowbasin and Powder Mountain. Hallar also runs the Hallar Aerosol Research Team (HART) at the U's William Browning Building, where students study urban air quality. The site gives the team a rare dual perspective on regional and urban atmospheric composition simultaneously.

Dean of the College of Science Pearl Sandick said, “I am grateful to have Gannet in this role, as an accomplished scientist, mentor and leader in the field. I’m excited to work with her as we prioritize student success while advancing the impactful research for which the department is known and fostering its continued growth.”

Research leadership

With her expertise and broad-ranging field experience, Hallar will bring cachet to a scientific sector known for its study of fluid dynamics, thermodynamics and radiative transfer to understand and predict weather and climate. Says Sandick, “It’s an exciting science in part because it is so relevant to our everyday lives. Gannet epitomizes that excitement.”

Hallar’s research leadership extends to major collaborative projects. She is a co-investigator on both the S2noCliME Field Campaign, a $4.8 million NSF-funded project, and the recent SNOWSCAPE Field campaign funded by the state of Utah to examine how mountainous terrain affects snowfall processes in the Intermountain West. "These campaigns give us a rare opportunity to integrate specialized radars, balloon measurements, surface instrumentation and more into one cohesive study of snowfall formation processes over mountains," she has said in earlier reports. "The impacts of declining snowpack are far-reaching for the economy and way of life in the West."

Beyond her research and teaching, Hallar serves as an affiliate scientist at the National Center for Atmospheric Research and on the leadership team of the U's Wilkes Center for Climate Science and Policy.

Says Hallar, “I am delighted to take on this position in a world-class department whose students, staff and faculty support and advance atmospheric science through exceptional research and teaching. The department’s work serves society with far-reaching impact, and I am honored to be part of that effort.”

Christopher Hacon

Algebraic geometer is tapped as Department Chair of Mathematics effective July 1, succeeding outgoing chair Tommaso de Fernex.

When Christopher Hacon won the celebrated Breakthrough Prize in 2018, his work was described as extending a foundational principle of geometry into higher dimensions. The award is designed to honor scientists as heroes of our society, to inspire the next generation and to champion science as a global, apolitical endeavor.

International stature

Now the incoming Chair of the Department of Mathematics at the University of Utah, Hacon brings that same ambition to a new role, this time as an ambassador of math and science at the U and beyond. The appointment, according to outgoing chair Tommaso de Fernex, could not be more fortuitous. "His international stature in the field of algebraic geometry is immense," De Fernex says of his colleague, "marked by revolutionary research and a prominent global standing" further reflected in numerous prestigious awards, distinguished memberships and service to the profession in several prominent roles.

And yet, de Fernex continues, Hacon "is equally defined by his exceptional departmental citizenship and humble leadership, . . . choosing to dedicate his career to this university despite competing offers from several top institutions."

That same grounding carries into how Hacon thinks about his work. He describes his research in the language of curiosity and incremental understanding. He admits to spending "countless hours trying to prove algebraic lemmas and theorems, and most of the time getting it wrong and having to start from scratch." His intuition comes from abstract pictures in his mind that try to capture a few key elements of a problem before the real work of proof-writing, the algebraic part of doing what he does, begins. That blend of imagination and rigorous logic—the visual and the algebraic working in tandem—sits at the heart of his field.

Two-holed donut

Algebraic geometry uses algebra to define curves, surfaces and high-dimensional spaces, studying the geometry of zero sets of polynomials. What this means is that geometric shapes can be perfectly defined and analyzed by finding where polynomial equations equal zero. Since the Breakthrough Prize, Hacon has focused particularly on moduli spaces: the systematic cataloguing of all possible shapes within a given class, such as identifying the precise number of parameters needed to fully describe every possible two-holed donut.

A central open question driving this work is whether the number of possible shapes in high dimensions is finite or infinite. He and others conjecture finiteness, and have proved it in most cases, but a complete proof remains elusive. His research also reaches into theoretical physics, where the mathematical operation known as a "flop,” one of the topics for which he won the prize, describes how the hidden six-dimensional structures of the universe might transition from one shape to another.

As for his new role, Hacon's aspirations are modest and duty-driven. He'll scale back teaching and hopes to maintain research, but his primary goal is simply to give back to a department that has served him well. He aspires to do as good a job as his predecessors and leave the math department in as good a shape as he found it. It's less a grand transformational agenda than a quiet expression of stewardship and gratitude.

Dean of the College of Science Pearl Sandick applauds that approach. “Christopher is an incredible mathematician who has profoundly shaped the math program at the U. I’m looking forward to working with him as a new department chair. ”

For Christopher Hacon who has spent nearly three decades at Utah—as post-doctoral researcher and faculty—the appointment to chair feels less like an arrival than a natural continuation, the work of building something that outlasts any single result. To quote him from his 2018 Breakthrough Prize: "this work is the culmination of sustained efforts by many brilliant mathematicians."

By David Pace
Bianca Lyon contributed to this story

College of Science