Alum to present on ozone and greenhouse gasses Sept. 27

Dr John Barnes ’75, director of the NOAA Mauna Loa Observatory, will give a presentation on “Ozone and Greenhouse Gases: An Update on Two Environmental Issues” at 4 p.m. Tuesday, Sept. 27, in Hoffman Hall, Room 217.

His talk will begin by noting that in 1958, the longest-running, continuous measurement of carbon dioxide in the atmosphere was started at Mauna Loa Observatory on the Big Island of Hawaii. In just a few years, Charles David Keeling of Scripps Oceanographic Institute was able to see two things: that there was a yearly cycle, and that the average level was increasing. This was the first realization that humankind’s activities were affecting the entire planet’s atmosphere.

Some years later, it was hypothesized that some widely used chemicals, CFCs and others, might reach the stratosphere where they could destroy ozone in the naturally occurring ozone layer. This was graphically proved to be true with discovery of the Antarctic ozone hole. The status of these two issues and their possible environmental consequences will be described, along with a global network of measurements that track the changes.

Dr. John E. Barnes has worked as a scientist at the NOAA Mauna Loa Observatory since 1993, and has been director since 1998. His main research concentrates on measuring particulates (aerosols) and their properties in the air. He attended graduate school at Colorado State University (M.S. Physics, 1980) and received his Ph.D. in physics from the University of Minnesota in 1988 where he worked on ozone properties and became interested in atmospheric physics. He spent five years working at the University of Michigan and has also worked in the aerospace industry on electric propulsion and the space shuttle.

The talk is sponsored by the Physics and Astronomy Club, the physics honor society Sigma Pi Sigma, and the Department of Physics.