Atmospheric Chemistry, climate
American Philosophical Society, elected 2000
Outstanding Alumnus, College of Engineering, University of Illinois, 2000
Bower Award and Prize for Scientific Achievement (Franklin Institute, Philadelphia, 1999)
United Nations Environment Program Ozone Award, 1997
Invited to contribute a "Citation Classic" Current Contents, Institute for Scientific Information, Philadelphia, 1994 (coauthored with R. S. Stolarski)
Distinguished Alumnus Award, Dept. of Electrical and Computer Engineering, University of Illinois, 1992
American Academy of Arts and Sciences, elected 1991
National Academy of Sciences, elected 1990
James B. Macelwane Award, American Geophysical Union, 1979 for significant contributions to geophysics by an outstanding young scientist.
Earth's atmosphere is a complex chemical mixture whose composition is in a state of flux. Our research focuses on the chemical composition of the atmosphere and human-induced changes to it. We are especially interested in chemicals and processes that act either to influence the ozone layer or the earth's infrared greenhouse effect. We conduct research through measurements of relatively long-lived gases and through computer modeling of atmospheric kinetic processes.
In our measurement projects we use gas chromatographic techniques to analyze for selected chemicals in samples of background air and also from chambers placed over hypothesized sources. The use of chambers permits the estimation of fluxes from source regions into the atmosphere, for example, rice paddies in the case of CH4. We are also measuring the release rates of CH3Br from plants. In these measurements of fluxes we also study the processes that control the fluxes. GC/MS techniques are used for some specialized purposes, including identification of unknown gases.
Because atmospheric methane amounts are increasing worldwide, it is important to determine the sources and sinks of methane as accurately as possible. To augment our field studies of CH4 emissions our group analyzes methane for the ratios of the stable-carbon and the stable-hydrogen isotopes. This laboratory is shared with several other UCI faculty and staff.
Photosynthate allocations in rice plants: Food production or atmospheric methane, R. L. Sass & R. J. Cicerone, Proc. Nat. Acad. of Sciences, 99, 11993-11995, 2002.
Environmental controls over methyl halide emissions from rice paddies, K. Redeker and R. J Cicerone, Global Biogeochemical Cycles, in press 2003.
Physiological and Biochemical Controls over Methyl Halide Emissions from Rice Plants, K. Redeker, S. L. Manley, M. Walser and R. J. Cicerone, Global Biogeochemical Cycles 17, in press, 2003.
Measurements of Ambient Atmospheric C2H5Cl and other Ethyl and Methyl Halides at Coastal California sites and over the Pacific Ocean”", Jason C. Low, Nun-Yii Wang, Jody Williams and Ralph J. Cicerone, J. Geophys. Res. Atmospheres. 108, ACH7-ACH-13, 2003. doi10.1029/2003JD003620
Inter- and Intra-field Variability of Methyl Halide Emissions from Rice Paddies, K. Redeker, J. Andrews, F. Fisher, R. L. Sass and R. J. Cicerone, Global Biogeochemical Cycles, 16, No. 4, 72-1 to 72-9, 2002
Emissions of methyl halides and methane from rice paddies, Kelly Redeker, Nun-Yii Wang, Jason C. Low, Andrew McMillan, Stanley Tyler and R. J. Cicerone, Science 290, 966-969, 2000.
Experimentally determined kinetic isotope effects in the reaction of CH4 with Cl: implications for atmospheric CH4, S. C. Tyler, H. O. Ajie, A. L. Rice, R. J. Cicerone and E. O. Tuazon, Geophys. Res. Lett. 27 1715-1718, 2000.
Methyl Bromide Emissions from Agricultural Field Fumigations in California, Jody Williams, Nun-Yii Wang and R. J. Cicerone, Journal of Geophys. Res. 104, 30,087 - 30,096, 1999.
Atmospheric Methyl Halides and Dimethyl Sulfide from Cattle, Jody Williams, Nun-Yii Wang, Ralph J. Cicerone, Kazuyuki Yagi, M. Kurihara and Fuminori Terada , Global Biogeochemical Cycles, 13, 485-492, 1999.
Carbon Isotopic Composition of Atmospheric Methane: A Comparison of Surface Level and Upper Tropospheric Air, S. C. Tyler, H. O. Ajie, M. L. Gupta, R. J. Cicerone, D. R. Blake and E. J. Dlugokencky, J. Geophys. Res., 104, 13,895-13,910, 1999.
"12C/13C Kinetic Isotope Effects in the Reactions of CH4 with OH and Cl," M. L. Gupta, M. P. McGrath, R. J. Cicerone, F. S Rowland and M. Wolfsberg, Geophysical Research Letters, 24, 2761-2764, 1997.
"Global Atmospheric Distributions and Source Strengths of Light Hydrocarbons and Perchloroethylene," M. L. Gupta, R. J. Cicerone, D. R. Blake, F. S. Rowland and I. S. A. Isaksen, J. Geophys. Res. 103, 28219-28237, 1998.
"Perturbation to Global Tropospheric Oxidizing Capacity Due to Latitudinal Redistribution of Surface Sources of NOx, CH4, and CO," M. L. Gupta, R. J. Cicerone and Scott Elliott, Geophys. Res. Lett. 25, 3931-3934, 1998.
"Human Forcing of Climate Change: Easing Up on the Gas Pedal," R. J. Cicerone, Proc. Nat. Acad. Sci. 97, 10, 304-10, 306, 2000.