Joukowsky Family Assistant Professor:
Phone: +1 401 863 3658
Phone 2: +1 401 863 3339
My research focuses on the reactive nitrogen cycle, with an emphasis on nitrate deposition. My interest in reactive nitrogen (e.g., NOx) extends from its connection to air quality through its impact on ozone and hydroxyl concentrations to the biogeochemical cycling of nitrogen in the earth system via formation of nitric acid (or nitrate), a major component of acid rain and a source of biologically available nitrogen.
I graduated magna cum laude in 1998 with a B.Sc. in marine science and chemistry from the University of Miami in Coral Gables, FL. After a one-year stint working at the National Oceanic and Atmospheric Administration's Geophysical Fluid Dynamics Laboratory, I began graduate school in the Department of Geosciences at Princeton University. Graduating with a Ph.D. in 2004, I subsequently became a postdoctoral researcher at the University of Washington with a fellowship from the Joint Institute for Study of the Atmosphere and Ocean (JISAO). I joined the faculty at Brown in 2008, and continue to pursue my varied research interests in the global N cycle, the biogeochemical record in ice cores and global connections between atmospheric chemistry and climate.
My research draws on principles from different individual disciplines, bringing a novel set of skills to the challenge of understanding the impacts humans have had on the composition of the atmosphere, the biosphere and climate. My research is driven by questions such as: what is the impact of anthropogenic emissions on the oxidation capacity of the atmosphere? What are the current impacts of acid deposition on streams, lakes, and the terrestrial biosphere? How has the biogeochemical cycling of nitrogen changed through time? What are the connections and feedbacks between the air quality, the physical climate system, and the health of the biosphere? To address these questions, I am currently utilizing novel isotopic measurement and modeling studies in the present environment, as well as characterizing how the environment has changed though time based on the interpretation of ice core measurements.
My recent focus has been on the reactive nitrogen cycle, with emphasis on nitrate deposition. Nitrate deposition in rain, snow, ice and aerosols is the main sink of reactive nitrogen oxides (NOx) from the atmosphere. My interest in NOx extends from its connection to the oxidizing efficiency of the atmosphere through its impact on ozone and hydroxy (OH) concentrations to the biogeochemical cycling of nitrogen in the earth system via formation of nitric acid (or nitrate), a major component of acid rain and a source of biologically available nitrogen. Using the isotopic composition of nitrate, I am investigating variations in the sources, chemistry, and transport of NOx. On short time scales, this has implications for studying air quality and acid deposition impacts. On longer time scales, I am interested in the natural variability of NOx sources, and the connection between climate, atmospheric composition, and the biosphere.
Because humans have significantly altered the biogeochemistry of nitrogen in the recent past, I am especially interested in exploring this cycle in the modern environment. The isotopic composition of nitrate represents an exciting new tool that can be used to characterize anthropogenic versus natural sources of nitrate, as well as the oxidant composition of the atmosphere.
Joukowsky Family Assistant Professor of Geological Sciences (2011-present)
Joint Institute for Study of the Atmosphere and Ocean (JISAO) Fellowship recipient (2005-2008)
Department of Energy Graduate Research Education Fellowship recipient (2002-2004)
National Science Foundation Graduate Research Fellowship recipient (1999-2002)
Dean's Fund for Scholarly Travel Award (2001)
Phi Beta Kappa (1998)
Henry King Stanford Scholarship Recipient (1994-1998)
Florida Scholar's Award Recipient (1994-1998)
Florida Resident Access Grant Recipient (1994-1998)
Co-convener of special session entitled "Measurement and Modeling of N2O Fluxes and the Coupling with CO2 and CH4 Fluxes" at the American Geophysical Union Fall Meeting, 2011.
Co-convener of special session entitled "The Bioatmospheric N Cycle: N Emissions, Transformations, Deposition, and Terrestrial and Aquatic Ecosystem Impacts" at the American Geophysical Union Fall Meeting, 2011.
Co-convener of special session entitled "Investigation of Atmospheric Processes Using Stable Isotopes" at the American Geophysical Union Fall Meeting, 2010.
Co-convener of special session entitled "The Bioatmospheric N Cycle: N Emissions, Transformations, Deposition, and Terrestrial and Aquatic Ecosystem Impacts" at the American Geophysical Union Fall Meeting, 2010.
Member, American Geophyiscal Union
Co-founder, Board Member, Earth Science Women's Network
Co-editor of focus issue in Environmental Research Letters journal on "Connections between Atmospheric Chemistry and Ice and Snow," 2008.
Co-convener of special session entitled "Atmospheric Chemistry of Ice and Snow" at the American Geophysical Union Fall Meeting, 2007.
Proposal Reviewer, National Science Foundation, 2009-present.
Proposal Reviewer, French Polar Institute, 2009-present.
Journal Reviewer, Journal of Geophysical Research-Atmospheres
Journal Reviewer, Rapid Communications in Mass Spectrometry
Journal Reviewer, Geophysical Research Letters
Journal Reviewer, Soil Science Society of America Journal
Journal Reviewer, Environmental Science & Technology
Journal Reviewer, Journal of Atmospheric Chemistry
Journal Reviewer, Journal of Atmospheric Chemistry and Physics
Journal Reviewer, Journal of Marine Chemistry
GEOL 1350: Weather and Climate
GEOL 2920-V: Terrestrial Nitrogen and Carbon Cycling
GEOL 2910-C: The Global Nitrogen Cycle
Current Graduate Students:
Dorothy Fibiger (Chemistry)
Mengdi Cui (Brown-MBL)
Lead PI, Brown University, Office of the Vice President for Research Seed Funds, The Impact of Agricultural Practices on Greenhouse Gas Emissions and Air Quality: A Case Study in New England, Co-PI Jianwu Tang (Marine Biological Laboratory)
Lead PI, National Science Foundation, Atmospheric Chemistry, Collaborative Research: Isotopic and compositional investigation of the sources and interactions of reactive N in the marine atmosphere at Bermuda, Co-PIs: A. Peters (Bermuda Inst for Ocean Sciences), D. Sigman (Princeton Univ)
Co-PI, National Science Foundation (NSF), Ocean Sciences, Collaborative Research: GEOTRACES Atlantic Section Nitrate Isotope Measurements, Co-PIs: K. Casciotti, (Woods Hole Oceanographic Inst.), D. Sigman (Princeton Univ).
Lead PI, National Science Foundation, Arctic Sciences, Collaborative Research: The Impact of bromine chemistry on the isotopic composition of nitrate at Summit, Greenland, Co-PIs: J. Dibb (Univ of New Hampshire), L.G. Huey (Georgia Inst. of Technology)
Lead PI, National Science Foundation (NSF), ADVANCE, Collaborative Research: Career Advancement for Women through the Earth Science Women's Network (ESWN), Co-PIs: C. Weidinmyer (NCAR), T. Holloway and E. Marin-Spiotta (Univ of Wisconsin-Madison), S. Laursen (Univ of Colorado-Boulder), A. Steiner (Univ of Michigan).
Co-PI, Brown University Dean of the College, Curricular Development Grant, Co-PI: James Russell (Geo)
Lead PI, Brown University/NSF ADVANCE, Brown Career Development Award
- Brown's Earth Systems History Group
- New Proxy Reveals How Humans Have Disrupted N Cycle
- Facilitating career advancement for women in the Geosciences through the Earth Science Women's Network (ESWN)
- More about my research...