Background
Teaching
Research Interests
Publications and Presentations
Other Interesting Links
Background
I grew up near Chicago, but went to Los Angeles for my liberal arts education at Occidental College . There, I had my first exposure to research working with David West and Eileen Spain. After graduating (1996), I decided to do something unrelated to science and went to Argentina. I volunteered in a home for boys in Buenos Aires, learned Spanish, and ate a lot of beef. Chemistry still called me, however, and so I went to the University of Minnesota for graduate school. Working in the lab of Jeffrey T. Roberts, I learned about ultra high vacuum systems and applications to atmospheric chemistry. I left Minnesota in 2002 for NASA Ames Research Center, where I was immersed in the atmospheric science community. After three fun years, I came to Randolph-Macon in 2005. Since then, I've mentored a number of great students in my research lab and we've presented our work at naotional and international conferences. I also got married and have two little wonderful, energetic boys.
Teaching
CHEM 130 Environmental Chemistry; a non-majors course covering air pollution, ozone depletion, climate change, energy and fuels, and water resources
CHEM 311-312 Physical Chemistry: Thermodynamics, Kinetics & Quantum Mechanics
CHEM 340 Introduction to Laboratory Research; a laboratory intensive course for sophomore chemistry majors
FYEC 215 Winning and Worthy Women; a first-year course covering women who won the Nobel prize in physics, chemistry, or literature, including some who should have won but didn’t
Research Interests- Atmospheric and Environmental Interfaces
Interfaces are ubiquitous in the atmosphere, from the tiny surfaces of aerosol particles miles above the ground to the extensive sea ice and snow pack of high latitudes. Aerosol particles can serve as miniature chemical reactors, taking up gases and converting them to different compounds, affecting the concentrations of trace species in the atmosphere. Furthermore, cloud droplets form on aerosol seed particles. Both aerosol and cloud particles absorb radiation and reflect it back to space and/or back to earth, and therefore play an important role in climate. In snow and ice covered regions, organic gases evolve from the snow and appear to affect ozone and mercury chemistry. Such snow-induced chemistry may also occur in cities that experience snowfall, leading to concerns for human health. Our research focuses on laboratory studies that elucidate chemistry and dynamics at atmospheric interfaces and near-interfaces. In particular, three projects are currently being developed. 1) In order to understand the composition of acidic sulfate aerosols, we are investigating the dissolution and speciation (fast reversible reactions) of volatile organic compounds in sulfate solutions. 2) The feasibility of cross-reactions (between different organic compounds) in such solutions under atmospheric conditions will be assessed in an ongoing collaboration with NASA Ames Research Center. 3) We will explore ice surfaces at atmospherically relevant temperature and pressure. We have measured the thickness of liquid brine at the surface of ice. We are developing methods to measure the properties of the ice surface, such as its ability to solvate, and its effective pH.
Recent Publications
*R.L. Walker, *K.F. Searles, *G.M. Riggio and R.R.H. Michelsen. “Total Reflection Spectroscopy of the Interfaces of Ice and Solid Aqueous Salt Solutions,” manuscript in preparation for Journal of Chemical Physics.
R. Michelsen , *R. Walker, and D. Shillady. “Cluster Models of Aqueous Na+ and Cl- in Sea Water/Ice,” Journal of Nanoparticle Research, 14, 896-905, 2012.
M.P. Sulbaek Andersen, *J. Axson, R.R.H. Michelsen, O.J. Nielsen, and L.T. Iraci. “Solubility of Acetic Acid and Trifluoroacetic Acid in Low-Temperature (207-245 K) Sulfuric Acid Solutions: Implications for the Upper Troposphere and Lower Stratosphere,” Journal of Physical Chemistry A, 2011.
M.B. Williams, R.R.H. Michelsen, *J.L. Axson, and L.T. Iraci, “Uptake of acetone, acetaldehyde and ethanol in cold sulfuric acid solutions containing organic material: Carbon accretion mechanisms,” Atmospheric Environment, 44, 1145-1151, 2010.
L.T. Iraci, B.G. Riffel, C.B. Robinson, R.R. Michelsen, and R.M. Stephenson. “The Acid Catalyzed Nitration of Methanol: Formation of Methyl Nitrate via Aerosol Chemistry,” Journal of Atmospheric Chemistry, 58, 253-266, 2007.
R.R. Michelsen , S.J.R. Staton, and L.T. Iraci. “Uptake and Dissolution of Gaseous Ethanol in Sulfuric Acid.” Journal of Physical Chemistry A, 110, 6711-6717, 2006.
L.T. Iraci, R.R. Michelsen, S.F.M. Ashbourn, T.A. Rammer, and D. Golden. “Uptake of Hypobromous Acid (HOBr) by Aqueous Sulfuric Acid Solutions: Low-Temperature Solubility and Reaction,” Atmospheric Chemistry and Physics, 5, 1577-1587, 2005.
R.R. Michelsen , S.F.M. Ashbourn, and L.T. Iraci. “Dissolution, Speciation and Reaction of Acetaldehyde in Cold Sulfuric Acid.” Journal of Geophysical Research D, 109, D23205, doi:10.1029/2004JD005041, 2004.
Recent Presentations
R. Michelsen, *R. Walker and D. Shillady, “Cluster Models of Aqueous Ions, Na+ and Cl-,” International Symposium on Clusters and Nanostructures, Richmond, VA, November, 2011.
R.R. Michelsen, *R. Walker, *K.F. Searles, “Measurements of the Liquid Brine Layer on Frozen Salt Solutions via ATR-IR Spectroscopy,”242nd ACS National Meeting & Exposition, Denver, CO, United States, August 28-September 1, 2011.
R.R.H. Michelsen, *R.L. Walker, *K.F. Searles, and *G.M. Riggio. “Probing the liquid-like surface of frozen salt solutions via infrared spectroscopy,” 3rd Workshop on Air-Ice Interactions, New York, NY, June, 2011.
R.R.H. Michelsen, *R. Walker, and *K.F. Searles. “Infrared Detection and Modeling of an Interfacial Liquid Layer at the Ice-Ge Interface.” 11th Science Conference of the International Global Atmospheric Chemistry Project, Halifax, Nova Scotia, Canada, July, 2010.
R.R.H. Michelsen, “A Ramble through Atmospheric Chemistry.” Schapiro Undergraduate Research Fellowship Faculty Presentation, June, 2010.
R.R.H. Michelsen, *G.M. Riggio and *K.F. Searles. “Determining Acidity at the Ice-Solid Interface via ATR-IR.” 61st Southeast Regional Meeting of the American Chemical Society, San Juan, Puerto Rico, October 2009.
R.R.H. Michelsen and *G.M. Riggio. “Attenuated total reflection spectroscopy of ice films.” Abstracts of Papers, 235th ACS National Meeting, New Orleans, LA, United States, April 6-10, 2008.
R.R.H. Michelsen, *K. Vernier, *J. Axson, and *D. Morley. “Protonation of Alcohols in Sulfuric Acid Solutions at UT/LS Conditions.” Eos Trans. AGU, 88(52), Fall Meeting Suppl., Abstract A21E-0798, 2007.
R.R. Michelsen. “Atmospheric Encounters: Organic Vapors Meet Sulfate Particles.” Invited Seminar, Occidental College Department of Chemistry, Los Angeles, CA, March 2006.
R.R. Michelsen and L.T. Iraci. “Cross-Reactions of Organic Trace Compounds in Cold, Acidic Sulfate Particles.” American Geophysical Union 2005 Fall Meeting, San Francisco, CA, December 2005.
R.R. Michelsen, S.J.R. Staton, and L.T. Iraci. “Ethanol as a Fuel Component: Effect on Aerosol Composition” Air Pollution as a Climate Forcing: A Second Workshop, Honolulu, HI, April 2005.
R.R. Michelsen, S.F.M. Ashbourn, S.J.R. Staton, and L.T. Iraci. “Accommodation of Oxygenated Organic Vapors into Sulfate Particles: Dissolution, Speciation and Reaction.” 8th Scientific Conference of the IGAC Project, Christchurch, New Zealand, September 2004.
R.R. Michelsen, S.J.R. Staton, and L.T. Iraci. “How Does Chemistry Affect Gas Uptake? Oxygenated Organics and Sulfuric Acid.” American Chemical Society National Meeting, Philadelphia, PA, August 2004.
S.J.R. Staton, R.R. Michelsen and L.T. Iraci. “Ethanol Emissions: Interactions with Particles.” Posters on the Hill, Council for Undergraduate Research, Washington, DC, April 2004.
Other Interesting Links
Snowcrystals
NIST webbook
NASA Undergraduate Student Research Program