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