Knowledge Remembering Encyclopedia Britannica. In memoriam Sherwood Rowland. For 244 years, Encyclopedia Britannica has been the ne plus ultra of reference materials. Now the print version has succumbed to the digital age and we lament its passing. Sherwood Rowland was a Nobel Prize winning chemist who discovered that CFCs a prime component of aerosols and coolants would disintegrate and erode the ozone layer protecting the earth. His work was groundbreaking in the link between man-made chemistry and the environment. Frank Sherwood Rowland (June 28, 1927 -- March 10, 2012) was an American Nobel laureate and a professor of chemistry at the University of California, Irvine. His research was on atmospheric chemistry and chemical kinetics. His best-known work was the discovery that chlorofluorocarbons contribute to ozone depletion.[1][2] Born in Delaware, Ohio, Frank Rowland received a majority of his education in public schools and, due to accelerated promotion was able to graduate high school several weeks before his 16th birthday.[3] In the summers during his high school career, Frank was entrusted to run the local weather service station. This was Rowland's first exposure to systematic experimentation and data collection. After entering Ohio Wesleyan University, Rowland was able to graduate shortly before his 18th birthday and enlisted within the Navy due to people of his age being drafted. Rowland was discharged after 14 months as a non commissioned officer. After entering the University of Chicago, Rowland was assigned Willard F. Libby as a mentor and began to study radiochemistry. Rowland's thesis was about the chemical state of cyclotron-produced radioactive bromine atoms. Rowland received his B.A. from Ohio Wesleyan University in 1948. He then earned his M.S. in 1951 and his Ph.D. in 1952, both from the University of Chicago. He held academic posts at Princeton University (1952--56) and at the University of Kansas (1956--64) before becoming a professor of chemistry at the University of California, Irvine, in 1964. At Irvine in the early 1970s he began working with Mario J. Molina. Rowland was elected to the National Academy of Sciences in 1978 and served as a president of American Association for the Advancement of Science (AAAS) in 1993. His best-known work was the discovery that chlorofluorocarbons contribute to ozone depletion. Rowland theorized that man made organic compound gases combine with solar radiation and decompose in the stratosphere, releasing atoms of chlorine and chlorine monoxide that are individually able to destroy large numbers of ozone molecules. It was obvious that Frank had a good idea of what was occurring at higher altitudes when he stated "...I knew that such a molecule could not remain inert in the atmosphere forever, if only because solar photochemistry at high altitudes would break it down."[4] Rowland's research, first published in Nature magazine in 1974, initiated a scientific investigation of the problem. The National Academy of Sciences concurred with the findings in 1976 and in 1978 CFC-based aerosols were banned in the United States. Rowland performed many measurements of the atmosphere. One experiment included collecting air samples at various cities and locations around the globe to determine CCl3F North-South mixing. By measuring the concentrations at different latitudes, Rowland was able to see that CCl3F was mixing between hemispheres quite rapidly. The same measurement was repeated 8 years later and the results showed a steady increase in CCl3F concentrations. Rowland's work also showed how the density of the ozone layer varied by season increasing in November and decreasing until April where it levels out for the summer only to increase in November. Data gained throughout successive years showed that although the pattern was consistent, the overall ozone levels were dropping. With this data, the Montreal Protocol was passed and CFC emissions were regulated within Canada, the United States, Sweden, Norway, and all other major industrial countries.[5]

• published: 23 Mar 2012
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