Dr. Stanley C. Tyler
Research Faculty
Atmospheric Science, Biogeochemistry
Earth System Science Dept.
University of California, Irvine
220 Rowland Hall
Irvine, California 92697-3100
office: (949) 824-2685
lab: (949) 824-3271
fax: (949) 824-3256
e-mail: styler@uci.edu
BACKGROUND
Stan Tyler received his B.A. degree in chemistry and physics from UC Irvine in 1975, his M.S. in Physics from UCLA in , and M. A. and Ph. D. degrees in chemistry from UC Irvine in 1979 and 1983 respectively. Before joining the UC Irvine faculty he was a postdoctoral fellow (2 years) and staff scientist (8 years) at the National Center for Atmospheric Research in Boulder, Colorado from 1983 to 1993. His work has been sponsored by the U.S. Dept. of Agriculture, National Aeronautics and Space Administration, National Science Foundation, CalSpace Institute, and Lawrence Livermore National Laboratory.
RESEARCH INTERESTS
Studies of atmospheric chemistry, global budgets and biospheric-atmospheric interactions involving the trace gas species CH4, CO, CO2, N2O, and non-methane hydrocarbons.
Research focuses on sources, sinks, and source/sink distributions of these gases and the chemistry related to their formation and destruction. Key investigative tools include measurements of stable isotope ratios (13C/12C, D/H, 15N/14N, and 18O/16O) in these compounds and their precursors as well as measurements of their radiocarbon content, concentrations, fluxes, and distributions.
One current study is of air samples collected from fixed land surface locations, upper air samples (free troposphere to lower stratosphere) taken from aircraft, and shipboard transects of the Pacific Ocean between Los Angeles, CA and Auckland, New Zealand. Measurements include mixing ratio, d13C, dD, and 14C content of CH4 and CO. The data are interpreted by comparison to measurements reported at other sites and through the use of advanced calculalations and atmospheric models.
Our fixed surface sites are located at the mid-continental site Niwot Ridge, CO (41 N, 105 W) and at the coastal northern hemispheric site Montaña de Oro State Park, CA (35 N, 121 W). The California site is close to a terminus of our trans-Pacific shipboard sampling lane running between Los Angeles, CA and Auckland, New Zealand (covering approximately 35 N to 35 S latitude and approximately 115 W and 176 E longitude). We also have measured upper troposheric and lower stratospheric air samples from aircraft during the NASA-GTE PEM Tropics A program and NASA AEAP SONEX (Subsonic Assessment, Ozone and Nitrogen Oxide Experiment) through a collaboration with Profs. Don Blake and F. S. Rowland at UC Irvine and from NASA ER-2 aircraft during the SOLVE (2000), POLARIS (1997), and STRAT (1996) campaigns through a collaboration with Kristie Boering (UC Berkeley) and Elliott Atlas (NCAR).
A second research project measures CH4 and CO2 from emissions and in pore water and sediments from rice paddies in northern California. Isotopic measurements of flux chamber, plant stem, and pore water samples of gases are used to determined biogeochemical factors controlling production, oxidation, and release of CH4 in rice paddies, and to establish the relationship between agricultural practices, CH4 emissions, and atmospheric CH4. We collaborate with Prof. Michael Goulden of UCI to make year-round eddy covariance measurements of half-hour CH4 and CO2 flux using an open path infrared gas analyzer for CO2 and a continuous flame ionization detector for CH4. From these data we determine the relationship between CH4 efflux and CO2 uptake to answer the question of whether rice paddies are capable of sequestering globally important amounts of CO2.
PUBLICATIONS
Tyler, S. C., G. W. Brailsford, K. Yagi, K. Minami, and R. J. Cicerone. 1994. Seasonal variations in methane flux and d13CH4 values for rice paddies in Japan and their implications, Global Biogeochem. Cycles, 8, 1-12.
Tyler, S. C. 1994. Rice paddy methane and its role in the atmospheric methane budget: what isotopes of carbon and hydrogen can tell us, in "CH4 and N2O: Global Emissions and Controls from Rice Fields and Other Agricultural and Industrial Sources", K. Minami, A. Mosier, and R. Sass, Eds., NIAES Series 2, Symposium Volume of National Institute of Agro-Environmental Sciences, Tsukuba, Japan, pp. 117-134. (Invited)
Tyler, S. C., P. M. Crill, and G. W. Brailsford. 1994. 13C/12C fractionation of methane during oxidation in a temperate forested soil, Geochim. Cosmochim. Acta, 58, 1625-1633.
Chanton, J., J. Bauer, D. Siegel, P. Glaser, C. Kelley, S. Tyler, E. Romanowicz, and A. Lazrus. 1995. Radiocarbon evidence for the substrates supporting methane formation within northern Minnesota peatlands, Geochim. Cosmochim. Acta, 59: 3663-3668.
Gupta, M., S. C. Tyler., and R. J. Cicerone. 1996. Investigations of the causes for recent changes in the mixing ratio and (d13C of atmospheric CH4, J. Geophys. Res., 101, 22923-22932.
Zimov, S. A., Y. V. Voropaev, I. P. Semiletov, S. P. Davidov, S. F. Prosiannikov, F. S. Chapin III, M. C. Chapin, S. Trumbore, and S. Tyler. 1997. North Siberian lakes: a significant methane source fueled by Pleistocene carbon, Science, 277, 800-801.
Tyler, S. C., R. S. Bilek, R. L. Sass, and F. M. Fisher. 1997. Methane oxidation and pathways of production in a Texas paddy field deduced from measurements of flux, d13C, and dD of CH4, Global Biogeochem. Cycles, 11, 323-348.
Tyler, S. C., H. O. Ajie, M. L. Gupta, R. J. Cicerone, D. R. Blake, and E. J. Dlugokencky. 1999. Carbon isotopic composition of atmospheric methane: A comparison of surface level and upper tropospheric air, J. Geophys. Res., 104, 13895-13910.
Tyler, S. C., G. A. Klouda, G. W. Brailsford, A. Manning, J. M. Conny, and A. J. Jull. 1999. Seasonal snapshots of the isotopic composition of tropospheric carbon monoxide at Niwot Ridge, Colorado, Chemosphere: Global Change Sci., 1, 185-203.
Bilek, R. S., S. C. Tyler, R. L. Sass, and F. M. Fisher. 1999. Differences in CH4 oxidation and pathways of production between rice cultivars deduced from measurements of CH4 flux, and d13C of CH4 and CO2, Global Biogeochem. Cycles, 13, 1029-1044.
Pérez, T., S. E. Trumbore, S. C. Tyler, E. A. Davidson, M. Keller, and P. B. Camargo. 2000. Isotopic variability of N2O emissions from tropical forest soils. Global Biogeochem. Cycles, 14, 525-535.
Tyler, S. C., H. O. Ajie, A. L. Rice, E. C. Tuazon, and R. J. Cicerone. 2000. Experimentally determined kinetic isotope effects in the reaction of CH4 with Cl: Implications for atmospheric CH4, Geophys. Res. Lett., 27, 1715-1718.
Redeker, K., N.-Y. Wang, J. C. Low, A. McMillan, S. Tyler, R. Cicerone. 2000. Emissions of methyl halides and methane from rice paddies. Science, 290, 966-969.
Pérez, T., S. E. Trumbore, S. C. Tyler, P. A. Matson, I. Ortiz-Monasterio, T. Rahn, and D. W. T. Griffith. 2001. Identifying the agricultural imprint on the global N2O budget using stable isotopes. J. Geophys. Res., 106, 9869-9878.
Bilek, R. S, S. C. Tyler, M. Kurihara, and K. Yagi. 2001. Investigation of Cattle Methane Production and Emission over a 24-hour Period using Measurements of d13C and dD of Emitted CH4 and Rumen Water. J. Geophys. Res., 106, 15405-15413.
Rice, A. L., A. A. Gotoh, H. O. Ajie, and S. C. Tyler. 2001. High precision continuous flow measurement of d13C and dD of Atmospheric CH4. Anal. Chem., 73, 4104-4110.
Chidthaisong, A., K.-J. Chin, D. Valentine, and S. C. Tyler. 2002. A comparison of isotope fractionations of carbon and hydrogen from paddy field rice roots and soil bacterial enrichments during H2/CO2 methanogenesis. Geochim. Cosmochim. Acta, 66, 983-995.
Macalady, J. L., A. M. S. McMillan, S. C. Tyler, and K. M. Scow. 2002. Population dynamics of methane-oxidizing bacterial groups in California rice paddies. Environ. Microbiol, 4, 148-157.
Rice, A. L., S. C. Tyler, M. C. McCarthy, K. A. Boering, and E. Atlas. The carbon and hydrogen isotopic compositions of stratospheric methane: Part 1. High-precision observations from the NASA ER-2 aircraft. (submitted to J. Geophys. Res., 2002)
McCarthy, M. C., K. A. Boering, A. Rice, S. Tyler, P. Connell, and E. Atlas. The carbon and hydrogen isotopic compositions of stratospheric methane: Part 2. 2-D model results and implications for kinetic isotope effects. (submitted to J. Geophys. Res., 2002)
Tyler, S. C, R. S. Bilek, T. Hosono, and K. Yagi. A laboratory determination of diffusional fractionation of isotopic carbon in CH4 from rice plant transport. (submitted to Global Biogeochem. Cycles, 2002)