Prof. Kimberly A. Prather

Office: Urey Hall Addn 3020-C
Phone: 858-822-5312 
Email: kprather@ucsd.edu 
Web: atofms.ucsd.edu caice.ucsd.edu 
Group: View group members

Education

1990 Ph.D., University of California, Davis
1985 B.S., University of California, Davis

Appointments

1990-92 Postdoc, Physical Chemistry, University of California, Berkeley

Awards and Academic Honors

Research Interests

We are working as part of a new Center funded by NSF, the Center for Aerosol Impacts on Climate and the Environment (NSF-CAICE)--see http://caice.ucsd.edu for further details and updates.
Our research involves making measurements of atmospheric aerosol chemistry and developing and using new analytical methods for these measurements. Aerosols occur in the environment in various forms: clouds of ice or water droplets, salt particles from ocean spray, and smoke from a variety of combustion sources. They play an enormous role in our daily lives, from affecting visibility and global climate change to endangering our health. Due to applications in research, medicine, and industry, there is great scientific interest in aerosols, however relative to their gas-phase counterparts, limited information exists regarding their complex chemistry.
Conventional analytical methods for analyzing aerosols involve isolating particles on filters with subsequent analysis performed in the laboratory. Unfortunately, these isolation processes often disturb the aerosol and thus render the data questionable because the particles evaporate or react before analysis. To overcome these difficulties, we developed aerosol-time-flight mass spectrometry (ATOFMS). This represented the first analytical technique to provide the precise size and chemical composition of individual aerosol particles in real-time. Some examples of aerosol systems that we characterize in the laboratory using ATOFMS include suspended dust, sea salt, and a variety of combustion particles. In addition, we recently developed a much smaller ATOFMS, which has been flown over Colorado, northern and southern California, and most recently, the Caribbean. In field studies, we strategically position our transportable instruments at sites that allow us to monitor the evolution of single particles in the atmosphere over time. In regional and international studies, these instruments are being used to study the direct effect of aerosols on visibility, pollution levels, cloud formation, and the global radiation balance.
Another major thrust of our research involves developing new techniques for analyzing organic species in aerosol particles. This is an extremely complex problem as there are hundreds of organic species in particles, yet only 10-20% of the mass has been identified. We are approaching this problem by using tunable laser wavelengths and selective reagent ions in chemical ionization.
Another area of interest involves using an ATOFMS instrument as an online probe for monitoring heterogeneous gas-particle reactions in the laboratory. The ATOFMS is interfaced to a flow tube where heterogeneous reactions of tropospheric concern are simulated. Aerosols of known size and composition are created and reacted under controlled conditions. The fundamental question of which factors (i.e. size, composition, charge) influence heterogeneous gas-particle reactions are being addressed.
Controlled laboratory studies such as these assist in sorting out data obtained from atmospheric studies, complicated by the numerous chemical processes occurring at any time. The information obtained will generate new models for atmospheric processes, which will be directly applicable in efforts to control ozone depletion, improve air quality, and develop an understanding of the impact of aerosols on global climate. 

Outreach Activities

I have been heavily involved in promoting diversity and increasing participation by under-represented groups both within UCSD and outside of the University. My group is typically comprised of 60-70% female Ph.D. students and postdoctoral fellows. I spend a significant amount of time mentoring my entire group on career and life choices, negotiating and managing a research team, and acquiring the skills needed to research at the highest possible level. We also have established a research partnership with the University of Puerto Rico (UPR). Members of my research group and I have visited there, given lectures, and performed research investigating the impact of African dust transport on the Caribbean region. As part of our NSF Center, CAICE, students from UPR will have the opportunity to come and participate in ocean-atmosphere studies at the ocean-atmosphere facility at Scripps. We also accept students from UCSD academic enrichment programs that focus on broadening participation, including the CAMP and McNair programs. As part of CAICE Phase II, we proposed to begin working more closely with local community colleges, introducing them to UCSD research opportunities and mentoring the transfer students when they arrive. The local community colleges have an extremely high percentage of under-represented groups, and thus we can increase their participation in scientific research by providing opportunities for the students to do summer research at UCSD.