Robert Rhew

Associate Professor
Ph.D. Scripps Institution of Oceanography, UC San Diego, 2001
Trace gas biogeochemistry, effect of land cover on trace gas exchange, biosphere-atmosphere interactions, and atmospheric pollution

539 McCone Hall

Rhew Lab Research Page

Welcome to the Trace Gas Biogeochemistry Laboratory.  Our research includes trace gas biogeochemistry, effect of land cover on trace gas exchange, biosphere-atmosphere interactions, and atmospheric pollution.  Our current focus is on three groups of Biogenic Volatile Organic Compounds (BVOCs):  halocarbons, reduced sulfur gases, and light hydrocarbons.

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.

Selected publications

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 Letters, 37, 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 Biogeosciences, 115, 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 Environment, doi: 10.1016/ j.atmosenv.2009.12.014 (2010).

O. Mazéas, J.C. von Fischer and R.C. Rhew, Impact 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 Environment, doi: 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 Arabidopsis, Current 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 Research, Vol. 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).

Personal interests

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