Ralph J. Cicerone: His scientific legacy and a long friendship.

The discovery of the Antarctic ozone hole and anthropogenic climate change has thrust the atmospheric sciences into the forefront of scientific disciplines, and such findings routinely appear on the front pages of the media and on the desks of world leaders. Two events can be cited as examples of the ascendency of the atmospheric sciences. First was the award of the 1995 Nobel Prize in Chemistry to three atmospheric chemists who performed pioneering work on the stability of the ozone layer. Second was the 2005 election of Ralph J. Cicerone as president of the esteemedNational Academy of Sciences (NAS), which counts among its members the nation’s preeminent scientists in all of the primary scientific disciplines. Ralph also contributed to the award of the 1995 Nobel Prize in Chemistry through his seminal work with another young scientist, Richard Stolarski, in 1974 (1) on the stability of the ozone layer. With Stolarski, Ralph showed how chlorine radicals were catalytically destroying ozone molecules in the stratosphere. Indeed, the 1995 Nobel committee for the chemistry prize acknowledged the Cicerone–Stolarski discovery of chlorine catalysis. The grandson of Italian immigrants, Ralph was born in New Castle, Pennsylvania, on May 2, 1943, into a close-knit extended family. He died at his home on November 5, 2016 in Short Hills, New Jersey, in the company of his wife, Professor Emerita Carol Cicerone, and their daughter and two grandchildren. According to Ralph, his primary focus during his junior high and high school years was on sports: “any kind.” He went on to the Massachusetts Institute of Technology where he majored in electrical engineering as an undergraduate and was the captain of the baseball team. Ralph’s passion for baseball persisted in later years, and as chancellor of the University of California, Irvine (UCI), he revived baseball as an officially recognized sport on campus. In gratitude, the university named its baseball stadium Cicerone Field at Anteater Ballpark. I know his passion for sports first hand; during a dinner at his Irvine, California house in 1990, Ralph proudly told me, with that familiar charming glint in his eyes, about his daughter Sara’s achievements in high school tennis. Ralph was the first in his family to attend college and completed his doctorate in electrical engineering and applied physics at the University of Illinois at Urbana– Champaign. Although he was not particularly fond of chemistry as an undergraduate, Ralph went on to make his seminal contribution in atmospheric chemistry with Stolarski as a postdoctoral fellow at the University ofMichigan. Ralph was primarily an atmospheric chemist who became interested in climate change science later in his career. Ralph’s first article on climate change was likely the one we wrote together in 1983 (2), about how atmospheric chemistry and atmospheric physics were coupled and the role of this chemistry–physics feedback in global warming. We spent many nights in the basement of the computing center, in between submitting our computer program decks, discussing the scientific underpinnings of climate change. I vividly recall the deep Ralph J. Cicerone. Photograph by Mark Finkenstaedt and image courtesy of the National Academy of Sciences.