Life and Career
F. Sherwood Rowland was born on 28 June 1927, in Ohio, Delaware. His father was a professor of mathematics and chairman of the department at Ohio Wesleyan, and his mother was a Latin teacher. Rowland demonstrated academic excellence from a young age, and graduated from high school at the age of fifteen. He was then charged with supporting the U.S. Weather Service by operating a local weather station, where he determined the minimum and maximum daily temperatures and total received precipitation. This exposed Rowland to practical skills like the collection of data through systematic experiments. Rowland was famed for his integrity and curiosity to uncover the truth and dive to its depth. In the initial phase of his career, he was a Radar trainer in the U.S. Navy. He subsequently attended the University of Chicago for his PhD, where he was mentored by a set of Nobel laureates, including Willy Libby. Rowlandâ€™s contribution towards the credibility of scientific research and channeling it for public awareness was remarkable.
Rowlandâ€™s work on stratospheric ozone depletion
The year of 1987 was recorded as one of the warmest years globally, due to a significant rise in temperature, and a decrease in the amount of precipitation received latitudinally around the globe. Previously, a five to six Í’C increase in the temperature of the surface of Greenland was satisfactorily explained by the phenomenon of a polar ice front. But in 1987, there was a notable rise in temperature based on the study on ice core data carried out in the Vostok, Antarctica station. This caused alarm, and opened scopes for scientists all over the world to carry out research on climate change widening up the field of atmospheric chemistry.
By this time, Rowland had already started his research work for understanding the role of halocarbons in the atmosphere and measurement of ozone globally initiating, from 1978. His research group collected air samples throughout the globe from both hemispheres to carry out gas chromatographic survey of trichlorofluoromethane (CClâ‚ƒ F), also called CFC-11. He found that, although more than 95 percent of the CFCs were emitted in the Northern hemisphere, there was very little hemispheric variation. Further in the 1980s, there was a constant rise in the CFCs in the Southern hemisphere, exceeding the Northern hemisphere by 10 percent. He estimated the mean life of CClâ‚ƒ F to 75 years (few with 140 years), which showed that CFCs produced 10-12 years back are retained in the atmosphere by 90 percent.
In the uppermost strata of the atmosphere, (upper stratosphere), the CFCs get exposed to the ultraviolet radiation emitted from the Sun, hence, the carbon-chlorine bond breaks releasing the chlorine atom. Chlorine atoms undergo reaction with the ozone molecule thereby creating a rupture in the ozone layer .