Dr. John Hallett: Four Decades of Research with DRI

More than 40 years into his DRI career, atmospheric physicist is still “doing what I want”.

After 43 years as an atmospheric physicist at DRI in Reno, the institute’s longest-serving researcher, John Hallett, Ph.D., finds himself on a scientific frontier that may seem relatively new to some, yet it’s one he’s been working in for years: climate change.

“All of the instruments you see scattered about here have a key role in characterizing a changing climate,” he says, his blue-gray eyes scanning the array of devices that crowd the Ice Physics Laboratory, which he directs.

To the uninformed, the boxes and wires might seem just so much electronic detritus. Yet the instruments, which he devised with colleagues at DRI and other institutions, are central to his work measuring the properties of precipitation, notably ice crystals, amid what he terms “a changing moisture climate.”

Among the instruments is one deceptively simple-looking device — trademarked as the HotPlate Total Precipitation Sensor — that he developed with Roy Rasmussen, Ph.D., of the National Center for Atmospheric Research in Boulder, Colo.

The electrical, disk-like metal instrument represented a design breakthrough when it was announced in 2003 because it calculates real-time rates of precipitation at high resolution. That makes it useful in characterizing freezing rain and snow when placed, for example, along airport runways.

He currently is principal investigator in development of an enhanced “T-probe,” a research instrument that could be mounted on aircraft to provide highresolution measurements of ice particles and supercooled water in clouds. The device could prove relevant to detecting potential icing hazards.

An Early Interest in Science

Dr. Hallett’s life in science has a number of meaningful touchstones. Born and raised in Bristol, England, at age 10 he witnessed an ice storm that made him wonder about the physics of ice crystals. He slept in air-raid shelters when warplanes bombed Bristol during World War II, in an era when many planes fell victim to icing, not flak. Alleviating the risks that icing poses to aircraft is a major focus of his research.

As a teenager, he built his neighborhood’s first television set, prelude, perhaps, to the measuring instruments he has developed over the years. After World War II, and especially after the Soviet Union launched Sputnik 1 in 1957, science was the place to be, and he was there.

Dr. Hallett earned a bachelor’s degree in physics from the University of Bristol in 1953, then a Ph.D. in meteorology at Imperial College, at the University of London. He met many Americans at the latter, including one named Wendell A. Mordy, who’d been a military weather officer in World War II.

Joining DRI in 1966

Years later, in 1966, his research and acquaintance with Dr. Mordy led him to the Desert Research Institute, at the University of Nevada in Reno. Dr. Mordy was DRI’s first director. Dr. Hallett liked what he found and, with longstanding support from the National Science Foundation, has been a DRI mainstay ever since.

“The people I work with here are pretty good at what they do,” he says, “and that’s important.”

A research professor in DRI’s Division of Atmospheric Sciences (DAS), Dr. Hallett’s interests include cloud physics, cloud electrification, atmospheric chemistry, climate dynamics and physical meteorology.

He holds DRI’s Edgar J. Marston Professorship of Atmospheric Physics, and is a Fellow of the American Meteorological Society. He received DRI’s Dandini Medal of Science in 1995, and in 1998 he became the first DRI researcher to receive the prestigious Nevada Board of Regents’ Researcher Award. He played a central role in development of the University of Nevada, Reno’s atmospheric sciences graduate program, which he directed for a decade.

“John has made major contributions over four decades to our understanding of the formation of ice crystals in the atmosphere, both primary and secondary processes, and the role ice crystals play in cloud dynamics and electrification,” says Ken Kunkel, Ph.D., director of DAS.

Looking Forward

Reflecting on DRI’s growth over its first half century, Dr. Hallett hesitates to guess at what the next 50 years could bring. Only one thing is certain, he says: There will always be mysteries for scientists to solve.

“There are lots of things that we don’t understand out there,” he says, gazing at a computer monitor that displays measurements from field instruments in the Sierra Nevada to the west. “There are still major problems out there to be investigated that have great scientific and practical applications.”