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.
Teaching
Fall 2005: General Chemistry Lab, Physical Chemistry I, and Advanced Lab I
Spring 2006: General Chemistry Lab, Physical Chemistry II, and Advanced Lab II
Research Interests
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 change. 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. In particular, three projects are currently being developed. 1) In order to understand the composition of acidic sulfate aerosols, we will investigate the dissolution and speciation (fast reversible reactions) of volatile organic compounds in sulfate solutions. 2) The feasibility of cross-reactions 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 will attempt to measure the properties of the ice surface, such as its ability to solvate, and its effective pH.
Recent Publications
R.R. Michelsen, S.J.R. Staton, and L.T. Iraci. “Uptake and Dissolution of Gaseous Ethanol in Sulfuric Acid.” submitted to Journal of Physical Chemistry A, October 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.
R.R. Michelsen and J.T. Roberts. "The Pressure-Dependent Kinetics of Acetone Uptake by Sulfuric Acid: Evidence for a Second-Order Heterogeneous Reaction." in press, Atmospheric Environment, 2004.
R.R. Michelsen and J.T. Roberts. “Reactive Uptake of 2,5-Hexanedione by Ultrathin Sulfuric Acid Films,” manuscript in preparation for Journal of Physical Chemistry.
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 Discussions, 5, 1213-1239, 2005.
B. Riffel, R.R. Michelsen, S.J.R. Staton, and L.T. Iraci. “Acid catalyzed nitration of methanol: Formation of methyl nitrate via aerosol chemistry,” manuscript in preparation for Journal of Atmospheric Chemistry.
Recent Presentations
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.
R.R. Michelsen, S.F. Ashbourn and L.T. Iraci. “Dissolution and Speciation of Oxygenated Organic Compounds in Sulfate Particles: Acetaldehyde.” American Geophysical Union 2003 Fall Meeting, San Francisco, CA, December 2003.
Other Interesting Links
Ozone data from NASA
Snowcrystals
NIST webbook
NASA Undergraduate Student Research Program