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Barbara J. Finlayson-Pitts is an American atmospheric chemist. She is a professor in the chemistry department at the University of California, Irvine and is the Director of AirUCI Institute. Her works explore the chemistry of the upper and lower atmosphere. She has been a member of the National Academy of Sciences since 2006 and is the laureate for the 2017 Garvan–Olin Medal.
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Education
Finlayson-Pitts received her Masters and PhD in chemistry from the University of California, Riverside in 1971 and 1973, respectively. After completing her postdoctoral fellowship at UC Riverside, she worked as a professor of chemistry at California State University, Fullerton from 1974-1994.
Research
Finlayson-Pitts served as the lead author of a 2009 study published in the Proceedings of the National Academy of Sciences that found burning fossil fuels releases nitrogen oxides, which interacts with gaseous hydrogen chloride, forming smog forming compounds. The study also found water vapor enhances the reaction.
Finlayson-Pitts and her team examined reactions between nitrogen dioxide (NO2) and dinitrogen pentoxide(N2O5), two common compounds created from fossil fuel combustion prevalent in the atmosphere, and gaseous hydrogen chloride (HCl), which has reached concentrations of a few parts per billion in polluted air. The authors of the study proposed N2O5 exists as an asymmetric dimer, NO2+NO3-. They also hypothesized water molecules promote the ionization of N2O5 to NO2+NO3-.When NO2 reacts with HCl (in the form of NO2+NO3-), it creates ClO and HNO3, and when N2O5 reacts with HCl, it forms ClNO2 and HNO3.
The team said the creation of the chlorine nitrogen compounds could have negative implications for the reliability and lifetime of electronics that are susceptible to corrosion when the reaction takes place in doors. Light absorption crosses into section in near ultraviolet and overlaps strongly not only with solar radiation but also with that from fluorescent lights, causing smog. The chlorine-containing molecules also react with nitrogen monoxide (NO) to produce ozone.
In another 2010 paper, Finlayson-Pitts detailed the role of halogens in reactions of the lower atmosphere. She said chlorine ions in the air help ozone formation, while bromine ions aide ozone destruction. Both ions are common in the troposphere due to cycles between seawater and gaseous phases.
Chloride, which is many times more abundant than bromine, reacts with nitrogen and oxygen-containing compounds in both the aqueous and gas phases to form a variety of molecules that scatter light, Finlayson-Pitts writes, including HCl, Cl2, ClNO2, ClO, and OClO.
Finlayson-Pitts also helped author a 2012 study published in the Proceedings of the National Academy of Sciences which concluded that new models may be needed to address secondary organic aerosols.
Finlayson-Pitts worked with scientists from UCI and the Pacific Northwest National Laboratory in Richland, Washington to research the processes leading to secondary organic aerosol formation. More specifically, they studied particle formation under the simultaneous oxidation α-pinene by ozone and NO3 radicals using an aerosol flow system. α-Pinene is are emitted by vegetation in varying quantities, depending on temperature and light conditions. The reaction of α-pinene with NO3 radicals in the atmosphere creates low-volatility particles, generating secondary organic aerosols. These particles were previously thought to condense into tiny droplets of liquid and then dissipate as those drops of liquid evaporate.
However, Finlayson-Pitts and the team she worked with found that secondary organic aerosols actually attach themselves more tightly to organic particles in the air. Because of this, previous models underestimate the amount of fine particles, which are linked to both lung and heart disease, in the air.
Currently, Finlayson-Pitts’ research focuses on understanding the fundamental kinetics, mechanisms, and photochemistry of gaseous reactions of particles, both inside and at their surface. Her research group is funded by the National Science Foundation and the Department of Energy. They are a part of a UCI-wide group, AirUCI, that focuses on air pollution, energy, and air quality and the effects of these elements on human health.
Finlayson-Pitts’ research group is also a part of a National Science Foundation-funded collaborative group that focuses on how air quality and climate change is affected by processes that occur at the atmosphere’s air-water interface.
Personal life
Her husband, James Pitts (1921–2014) was also a notable chemist; they married in 1970. He followed her to the University of California, Irvine in 1994, where the two collaborated on research and co-authored books and other publications.