Eldon Earl Ferguson

Eldon Earl Ferguson, a world-renowned physicist and atmospheric scientist, passed away on 26 April 2017 in Paris. He was 91.

Ferguson was born in Rawlins, Wyoming. Growing up in Tulsa, Oklahoma, he entered the University of Oklahoma on a track scholarship and earned BS, MS, and PhD degrees in physics. After graduating in 1953, he served brief stints at Phillips Petroleum and the Naval Research labs before he entered academia as an assistant professor of physics at the University of Texas in Austin in 1957. There, Eldon began his remarkable, creative career of research on the chemical and physical processes in ionized gases. In 1962 he accepted a position at the newly created National Bureau of Standards (NBS) Central Radio Propagation Laboratory in Boulder, Colorado. At NBS, he started a research group by hiring two of his students from Texas, Art Schmeltekopf and Fred Fehsenfeld, and initiated a research program to investigate the interactions of charged particles, electrons and ions, in the upper atmosphere. The mission of the laboratory was to understand the role these particles played in controlling the atmospheric propagation of radio waves.

Under Eldon’s direction the group developed a new instrument called the “flowing afterglow” that revolutionized the laboratory study of gaseous ionic reactions. By separating the ion production, reaction, and detection zones using a flow reactor, the device offered unprecedented flexibility and accuracy to analyze reactions of positive and negative ions with a wide variety of atmospheric trace and transient species, including atoms, metal vapors, and radicals over a broad range of temperatures and kinetic energies. The current understanding of the ion chemistry of the atmosphere is based largely on the research carried out by the group. Their achievements included discovering the mechanism by which the positive ions of NO and O₂ are converted into protonated water clusters and the role that the reaction of O⁺ with vibrationally excited nitrogen plays in the production of NO in the ionosphere. In other studies they demonstrated a unique reaction mechanism called associative detachment, whereby an anion, such as O^–, reacts with an atom or molecule such as H₂, to form a free electron, which carries away the energy necessary to stabilize the product, H₂O. They and other groups around the world have adapted the technology to a wide variety of applications including thermochemistry, spectroscopy, trace gas detection, medical analysis, and interstellar chemistry.

Eldon became the director of a new research division, the Aeronomy Laboratory, formed around his group’s research. In 1966 the Laboratory moved from NBS into the Environmental Science Services Administration and in 1970 into the present National Oceanic and Atmospheric Administration (NOAA). Around that time, the Laboratory’s research emphasis evolved to topics related to environmental issues, such as stratospheric ozone depletion, acid precipitation, and air pollution. Eldon built and led an exceptional scientific organization with world-leading research programs in the measurement of atmospheric trace gases, laboratory studies of chemical reactions, and model simulations of the atmosphere. Much of the Laboratory’s success was based upon the development of innovative new instruments for critical atmospheric measurements. Using this capability, the Laboratory played a vital role in the development of international environmental policy, such as the Montreal Protocol, which eliminated the use of ozone depleting chemicals, such as, chlorofluorocarbons.

Eldon served as Director of the Aeronomy Laboratory until 1986 when he retired from NOAA and took a position as Director of Research at the Centre National de la Recherche Scientifique in Orsay, France. After four years, he returned to Boulder to serve as Director of the NOAA Climate Monitoring and Diagnostics Laboratory until retiring in 1996. During his time in Boulder, he was an adjunct professor in the department of chemistry at the University of Colorado where he taught, trained graduate students, and helped recruit outstanding faculty. Throughout his career he maintained a strong interest in ion reactions and had many affiliations and collaborations with scientists and laboratories around the world.

His research and administrative skills were recognized with numerous awards including from the US Department of Commerce, a Presidential Rank Meritorious Executive Award and two Gold Medals, the Will Allis Prize from the American Physical Society, the Schroedinger Prize from the Austrian Symposium on Atomic and Surface Physics, a Guggenheim Fellowship from the Max-Planck Institute for Physics in Munich, and a Humboldt Fellowship from the Max-Planck Institute for Nuclear Physics in Heidelberg.

Beyond Eldon’s accomplishments as a scientist and leader, he was an exceptional colleague, mentor, and supervisor. He loved the Colorado mountains, was an outdoorsman, an avid hiker and runner, and relished skiing with many friends and colleagues.

Eldon is survived by his beloved wife, Marie Durup Ferguson, a noted scientist in her own right with whom he coauthored several publications; daughter, Jill Ferguson, granddaughters, Marisa Wilson and Darien Reed, and great-grandson, August Wilson; son, Mark Ferguson and grandson, Matthew Ferguson.