Robert Rhew



Trace gas biogeochemistry, effect of land cover on trace gas exchange, biosphere-atmosphere interactions, and atmospheric pollution

539 McCone Hall

Rhew Lab Research Page             Sagehen Creek Field Station              Central Sierra Snow Lab

Welcome to the Atmospheric Biogeochemistry Laboratory.  Our research includes trace gas biogeochemistry, effect of land cover on trace gas exchange, biosphere-atmosphere interactions, and atmospheric pollution.  Our focus has been on three groups of Biogenic Volatile Organic Compounds (BVOCs):  halocarbons, reduced sulfur gases, and light hydrocarbons.  We are increasingly interested in the impacts that agriculture, invasive species, and fire management have on the atmosphere.  

Although trace gases constitute less than 1% of the composition of the atmosphere, they are compounds that regulate the Earth’s greenhouse effect, the balance of stratospheric ozone, and most of the chemical reactions in the atmosphere. In our trace gas biogeochemistry lab, we seek to quantify the biosphere-atmosphere exchange of environmentally important trace gases and to identify the physical and biological controls on those fluxes. We conduct our work in a wide range of natural and human-dominated ecosystems, including Arctic tundra, temperate grasslands, salt-affected lands, arid and semi-arid shrublands, boreal forest, temperate forest, and tropical ecosystems. This work will help to quantify globally significant sources and sinks, to assess the atmospheric lifetimes of these compounds (how long these compounds persist in the atmosphere), and to elucidate key biogeochemical processes that occur in nature.

We focus on halogen, sulfur, and carbon containing compounds that catalyze ozone destruction; influence the radiative energy balance of the planet; and/or act as proxies or byproducts of important ecosystem processes. This work is very interdisciplinary, involving the tools of analytical and atmospheric chemistry, soil geochemistry and microbiology, plant biology and genetics, ecosystem ecology and physical geography. Consequently, our laboratory invites the participation of students from a wide variety of backgrounds.

Professor Rhew also has a joint appointment with the Department of Environmental Science, Policy and Management.


Jiao, Y., W. Zhang, J.Y. Kim, M.J. Deventer, J. Vollering, and R.C. Rhew, Application of copper(II)-based chemicals induces CH3Cl and CH3Br emissions from soil and seawater, Nature Communications,  13, 47, (2022).

=Zhang, W., =Y. Jiao, R. Zhu, R.C. Rhew, B. Sun, and H. Dai, Chloroform (CHCl3) emissions from coastal Antarctic tundra, Geophysical Research Letters, 48, e2021GL093811, doi: 10.1029/2021GL093811 (2021)  (=authors contributed equally to this work)

Jiao, Y., J. Acdan, R. Xu, M.J. Deventer, W. Zhang and R.C. Rhew. Global methyl halide emissions from rapeseed (Brassica napus) using life cycle measurements. Geophysical Research Letters, 47, e2020GL089373. https://doi. org/10.1029/2020GL089373 (2020).

Zhang, W., Y. Jiao, R. Zhu, and R.C. Rhew.  Methyl chloride and methyl bromide production and consumption in coastal Antarctic tundra soils subject to sea animal colonies.  Environmental Science & Technology, 54, 13354-13363, (2020).

Shechner, M., A. Guenther, R. Rhew, A. Wishkerman, Q. Li, D. Blake, G. Lerner, and E. Tas, Emission of volatile halogenated organic compounds over various Dead Sea landscapes, Atmos. Chem. Phys., 19, 7667-7690, (2019).

Jiao, Y., A. Ruecker, M.J. Deventer, A. Chow and R.C. Rhew, Halocarbon emissions from a degraded forested wetland in coastal South Carolina impacted by sea level rise, ACS Earth and Space Chemistry, 2 (10), 955–967,  doi: 10.1021/acsearthspacechem.8b00033 (2018).

Deventer, M.J., Y. Jiao, S.H. Knox, F. Anderson, M.C. Ferner, J.A. Lewis, and R.C. Rhew, Ecosystem scale measurements of methyl halide fluxes from a brackish tidal marsh invaded with perennial pepperweed (Lepidium latifolium), Journal of Geophysical Research: Biogeosciences, 123, (2018).

=Rhew, R.C., =M. J. Deventer, A.A. Turnipseed, C. Warneke, J. Ortega, S. Shen, L. Martinez, A. Koss, B.M. Lerner, J.B. Gilman, J.N. Smith, A.B. Guenther and J.A. de Gouw, Ethene, propene, butene and isoprene emissions from a ponderosa pine forest measured by Relaxed Eddy Accumulation, Atmos. Chem. Phys., 17, 13417-13438, (2017).   (=authors contributed equally to this work)

Whelan M.E. and R.C. Rhew, Reduced sulfur trace gas exchange between a seasonally dry grassland and the atmosphere, Biogeochemistry, doi: 10.1007/s10533-016-0207-7 (2016).

Rhew, R.C. and J. Happell, The atmospheric partial lifetime of carbon tetrachloride with respect to the global soil sink, Geophysical Research Letters, 43, doi:10.1002/2016GL067839  (2016).

SPARC (46 authors), SPARC Report on the Mystery of Carbon Tetrachloride. Q. Liang, P.A. Newman, S. Reimann (Eds.), SPARC Report No. 7, WCRP-13/2016. doi:   Available at: (2016)

Wang, J-J., Y. Jiao, R.C. Rhew and A. T. Chow, Haloform formation in coastal wetlands along a salinity gradient at South Carolina, United States, Environmental Chemistry, doi: 10.1071/EN15145 (2016)

Whelan M.E. and R.C. Rhew, Carbonyl sulfide produced by abiotic thermal and photo-degradation of soil organic matter from wheat field substrate Journal of Geophysical Research Biogeosci., 120, doi: 10.1002/2014JG002661 (2015).

Rhew, R.C., Whelan M.E. and D.-H. Min, Large methyl halide emissions from south Texas salt marshes, Biogeosciences, 11, 6427-6434,doi: 10.5194/bg-11-6427-2014 (2014).

Khan, M.A.H., R.C. Rhew, K. Zhou and M.E. Whelan, Halogen biogeochemistry of invasive perennial pepperweed (Lepidium latifolium) in a peatland pasture, Journal of Geophysical Research Biogeosci. 118, 1–9, doi:10.1002/jgrg.20020 (2013).

Whelan M.E., D.-H. Min, and R.C. Rhew, Salt marsh vegetation: a carbonyl sulfide (COS) source to the atmosphere, Atmospheric Environment, 73, p. 131-137, doi: 10.1016/j.atmosenv.2013.02.048 (2013).

Khan, M.A.H., M.E. Whelan and R.C. Rhew, Analysis of low concentration reduced sulfur compounds (RSCs) in air: storage issues and measurement by gas chromatography with sulfur chemiluminescence detection. Talanta, 88, p. 581-586, doi: 10.1016/j.talanta.2011.11.038(2012).

Khan, M.A.H., M.E. Whelan and R.C. Rhew, Effects of temperature and soil moisture on methyl halide and chloroform fluxes from drained peatland pasture. J. Environmental Monitoring, 14, p. 241-249, doi:10.1039/c1em10639b (2012).

Rhew, R.C., Sources and sinks of methyl bromide and methyl chloride in the tallgrass prairie: applying a stable isotope tracer technique over highly variable gross fluxes, Journal of Geophysical Research Biogeosciences, 116, G03026, doi:10.1029/2011JG001704 (2011)

Montzka, S.A., S. Reimann, S. O’Doherty, A. Engel, A., K. Kruger, W.T. Sturges, D. Blake, M. Dorf, P. Fraser, L. Froidevaux, K. Jucks, K. Kreher, M. Kurylo, W. Mellouki, J. Miller, O.-J. Nielsen, V. Orkin, R. Prinn, R. Rhew, M. Santee, A. Stohl and D. Verdonik, Scientific Assessment of Ozone Depletion: 2010, Chapter 1. “Ozone-Depleting Substances (ODSs) and Related Chemicals”, World Meteorological Organization- Report No. 52  (2011).

Khan, M.A.H., R.C. Rhew, M.E. Whelan, K. Zhou & S. Deverel, Methyl halide and chloroform emissions from a subsiding Sacramento-San Joaquin Delta island recently converted to rice fields, Atmospheric Environment, 45, p. 977-985, doi:10.1016/j.atmosenv.2010.10.053(2011).

Rhew, R.C. and O. Mazéas, Gross production exceeds gross consumption of methyl halides in northern California salt marshes,Geophysical Research Letters37, L18813, doi: 10.1029/ 2010GL044341 (2010).

von Fischer, J., R. C. Rhew, G. Ames, B. K. Fosdick, and P. E. von Fischer, Vegetation height and other controls of spatial variability in methane emissions from the Arctic coastal tundra at Barrow, Alaska, JGR Biogeosciences115, G00I03, doi: 10.1029/2009JG001283(2010).

Rhew, R.C., C. Chen, Y.A. Teh, and D. Baldocchi, Gross fluxes of methyl chloride and methyl bromide in a California oak-savanna ecosystem. Atmospheric Environmentdoi: 10.1016/ j.atmosenv.2009.12.014 (2010).

O. Mazéas, J.C. von Fischer and R.C. RhewImpact of terrestrial carbon input on methane emissions from an Alaskan Arctic lake,Geophysical Research Letters, 36, L18501, doi:10.1029/ 2009GL039861 (2009).

Teh, Y.A., O. Mazéas, A. Atwood, T. Abel and R.C. Rhew, Hydrologic regulation of methyl chloride and methyl bromide fluxes in Alaskan Arctic tundra. Global Change Biology, Vol 15, Issue 2, doi: 10.1111/j.1365-2486.2008.01749.x (2009).

Rhew, R.C., Y.A. Teh, T. Abel, A. Atwood and O. Mazéas, Chloroform emissions from the Alaskan Arctic tundra, Geophysical Research Letters, 35, L21811, doi:10.1029/2008GL035762 (2008).

Rhew, R.C., B.R. Miller, and R.F. Weiss, Chloroform, carbon tetrachloride and methyl chloroform fluxes in southern California ecosystems,Atmospheric Environmentdoi: 10.1016/j.atmosenv.2008/05/038 (2008).

Teh, Y.A., Rhew, R.C., Atwood, A.R., and T. Abel, Water, temperature, and vegetation regulation of methyl chloride and methyl bromide fluxes from a shortgrass steppe ecosystem. Global Change Biology 14, p. 77-91, doi: 10.1111/j.1365-2486.2007.01480.x (2008).

Rhew, R. C. and T. Abel. Measuring simultaneous production and consumption fluxes of methyl chloride and methyl bromide in annual temperate grasslands. Environmental Science & Technology, 41, p. 7837-7843, doi: 10.1021/es0711011 (2007).

Rhew, R. C., Y. A. Teh, and T. Abel, Methyl halide and methane fluxes in the northern Alaskan coastal tundra, Journal of Geophysical Research, 112, G02009, doi:10.1029/2006JG000314 (2007).

Rhew, R. C., L. Østergaard, E. S. Saltzman, and M. F. Yanofsky, Genetic control of methyl halide production in ArabidopsisCurrent Biology, Vol. 13, 1809-1813 (2003).

Rhew, R.C., M. Aydin, and E.S. Saltzman, Measuring terrestrial fluxes of methyl chloride and methyl bromide using a stable isotope tracer technique, Geophysical Research Letters, Vol. 30, no. 21, 2103, doi: 10.1029/2003GL018160, (Nov. 7, 2003)..

Rhew, R. C., B. R. Miller, M. Bill, A. H. Goldstein, and R. F. Weiss, Environmental and biological controls on methyl halide emissions from southern California coastal salt marshes, Biogeochemistry, Vol. 60, 141-161 (2002).

Bill, M., R. C. Rhew, R. F. Weiss, and A. H. Goldstein, Carbon isotopic ratios of methyl bromide and methyl chloride emitted from a coastal salt marsh, Geophysical Research Letters, Vol. 29 (4), 10.1029/2001GL012946(2002).

Rhew, R. C., B. R. Miller, M. K. Vollmer, and R. F. Weiss, Shrubland fluxes of methyl bromide and methyl chloride, Journal of Geophysical ResearchVol. 106, 20,875-20,882 (2001).

Rhew, R. C., B. R. Miller, and R. F. Weiss, Natural methyl bromide and methyl chloride emissions from coastal salt marshes, Nature, Vol. 403, 292-295 (2000).


NCAR – National Center for Atmospheric Research

NOAA/CIRES – CU Boulder Cooperative Institute for Research in Environmental Sciences

National Association of Geoscience Teachers

University of California Natural Reserves System

Center for Excellence in Education – runs programs to promote STEM excellence, starting with high school students