Cooperative Institute for Research in Environmental Sciences at the University of Colorado Boulder

Eleanor C. Browne

Research Interests

My group develops instrumentation for measuring gases and aerosols in the atmosphere and uses this instrumentation to investigate how atmospheric processing affects the chemical composition of gases and aerosols. The group is specifically interested in organonitrogen and organosilicon compounds and investigates the fate of these compounds using laboratory and field measurements. Current work focuses on understanding the role of organonitrogen in new particle formation and growth, and in nitrogen deposition. The organosilicon work focuses on constraining the fate of organosilicon compounds that are found in personal care products and preferentially partition to the atmosphere. Our current instrument development work focuses on novel techniques for the fragment-free characterization of aerosol.

Current Research

Ambient Ion Chemistry

Atmospheric ions control the electrical properties of the atmosphere, influence chemical composition via ion-molecule and/or ion-catalyzed reactions, and affect new particle formation. Understanding the role of ions in these processes requires knowledge of ionic chemical composition.  Due to the low concentration of ions, chemical composition measurements have historically been challenging. Recent advances in mass spectrometry, such as the atmospheric pressure interface time-of-flight mass spectrometer (APi-TOF), are now making these measurements more feasible. We study the chemistry of ambient ions through field measurements to understand present day ambient atmosphere and laboratory experiments that simulate other planetary atmospheres such as early Earth and Titan.

Organosilicon Chemistry

Several million tons of organosilicon compounds, most notably volatile methyl siloxanes (VMS), are manufactured annually for use in a variety of applications including personal care products and adhesives. Despite estimates that over 90 percent of VMS environmental loading is present in the atmosphere, the multigenerational chemistry of VMS remains poorly constrained. We use an environmental simulation chamber to simulate atmospheric oxidation of siloxanes so we can detect the products of atmospheric reactions with these compounds as well as gather information about rate constants and reaction pathways of these reactions. 

Nitrogen Chemistry

Reduced nitrogen compounds negatively affect air quality, climate, and human health. These compounds have been shown to enhance new particle formation, promote brown carbon formation, and increase the toxicity of aerosol. Little is known about the impact reduced nitrogen has on either the gas phase or aerosol because measurements detailing their speciation and interactions with aerosol is lacking. Due to increases in food production, the concentrations of reduced nitrogen compounds are expected to increase in the future, and thus it is important to understand their speciation and transformations in the atmosphere. We conduct ambient and lab measurements to understand the sources and transformation of reduced nitrogen compounds in the atmosphere.

Instrument Development

Aerosols (fine particulate matter suspended in air) affect human health and the Earth’s radiative balance. Improving our knowledge of how aerosols affect climate and health requires measurements of aerosol chemical composition in order to improve our understanding of aerosol sources and sinks. These measurements, however, are analytically challenging as the aerosols with the greatest impacts on health and climate are submicron in diameter, present at concentrations of μg or less per cubic meter of air, and are composed of both inorganic and organic compounds. Furthermore, the composition of the organic fraction is complex, consisting of thousands of compounds, including those that are chemically and thermally labile. The group is currently working on developing a novel measurement technique that combines laser desorption with chemical ionization mass spectrometry.



Simplified schematic showing some possible NHx-organic compound reactions that we study. Note acid catalysis is not explicitly shown. Path A represents ammonium carboxylate salt formation, path B is ON oligomer growth, and path C is N catalyzed oligomer growth.

Simplified schematic of chemistry occuring in our Titan-like simulations.

Honors and Awards

  • American Society for Mass Spectrometry Research Award (2019)
  • NOAA Climate and Global Change Postdoctoral Fellowship (2012-2014)
  • NASA Earth Systems Science Fellowship (2010-2012)

View Publications

  • Reed, NW; Browne, EC; Tolbert, MA (2020), Impact of Hydrogen Sulfide on Photochemical Haze Formation in Methane/Nitrogen Atmospheres. Version: 1 ACS EARTH AND SPACE CHEMISTRY 4 (6) 897-904, issn: 2472-3452, doi: 10.1021/acsearthspacechem.0c00086
  • Alton, MW; Browne, EC (2020), Atmospheric Chemistry of Volatile Methyl Siloxanes: Kinetics and Products of Oxidation by OH Radicals and Cl Atoms. Version: 1 ENVIRONMENTAL SCIENCE & TECHNOLOGY 54 (10) 5992-5999, issn: 0013-936X, doi: 10.1021/acs.est.0c01368, PubMed ID: 32339458
  • Ugelow, MS; Berry, JL; Browne, EC; Tolbert, MA (2020), The Impact of Molecular Oxygen on Anion Composition in a Hazy Archean Earth Atmosphere. Version: 1 ASTROBIOLOGY 20 (5) 658-669, issn: 1531-1074, doi: 10.1089/ast.2019.2145, PubMed ID: 32159384
  • Browne, E; Stark, H; Abdelhamid, A; Nowak, J; Smith, J; Jayne, J; Worsnop, D (2019), Chemistry of organic reduced nitrogen in a rural environment. Version: 1 ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY Fall National Meeting and Exposition of the American-Chemical-Society (ACS) 258 , San Diego, CA, AUG 25-29, 2019, issn: 0065-7727
  • Berry, JL; Ugelow, MS; Tolbert, MA; Browne, EC (2019), The Influence of Gas-phase Chemistry on Organic Haze Formation. Version: 1 ASTROPHYSICAL JOURNAL LETTERS 885 (1) , Art. No. L6, issn: 2041-8205, doi: 10.3847/2041-8213/ab4b5b
  • Browne, EC; Zhang, XL; Franklin, JP; Ridley, KJ; Kirchstetter, TW; Wilson, KR; Cappa, CD; Kroll, JH (2019), Effect of heterogeneous oxidative aging on light absorption by biomass burning organic aerosol. Version: 1 AEROSOL SCIENCE AND TECHNOLOGY 53 (6) 663-674, issn: 0278-6826, doi: 10.1080/02786826.2019.1599321
  • Berry, JL; Ugelow, MS; Tolbert, MA; Browne, EC (2019), Chemical Composition of Gas-Phase Positive Ions during Laboratory Simulations of Titans Haze Formation. Version: 1 ACS EARTH AND SPACE CHEMISTRY 3 (2) 202-211, issn: 2472-3452, doi: 10.1021/acsearthspacechem.8b00139
  • Berry, JL, DA Day, T Elseberg, BB Palm, WW Hu, A Abdelhamid, JC Schroder, U Karst, JL Jimenez and EC Browne (2018), Laser Ablation-Aerosol Mass Spectrometry-Chemical Ionization Mass Spectrometry for Ambient Surface Imaging. Anal. Chem. Version: 1 90 (6) 4046-4053, issn: 0003-2700, ids: GA3HR, doi: 10.1021/acs.analchem.7b05255, PubMed ID: 29461799
  • Lim, CY, EC Browne, RA Sugrue and JH Kroll (2017), Rapid heterogeneous oxidation of organic coatings on submicron aerosols. Geophys. Res. Lett. Version: 1 44 (6) 2949-2957, issn: 0094-8276, ids: ES7WS, doi: 10.1002/2017GL072585
  • Brune, WH, BC Baier, J Thomas, X Ren, RC Cohen, SE Pusede, EC Browne, AH Goldstein, DR Gentner, FN Keutsch, JA Thornton, S Harrold, FD Lopez-Hilfiker and PO Wennberg (2016), Ozone production chemistry in the presence of urban plumes. Faraday Discuss. Version: 1 189 169-189, issn: 1359-6640, ids: DR7SJ, doi: 10.1039/c5fd00204d, PubMed ID: 27101799
  • Canagaratna, MR, P Massoli, EC Browne, JP Franklin, KR Wilson, TB Onasch, TW Kirchstetter, EC Fortner, CE Kolb, JT Jayne, JH Kroll and DR Worsnop (2015), Chemical Compositions of Black Carbon Particle Cores and Coatings via Soot Particle Aerosol Mass Spectrometry with Photoionization and Electron Ionization. J. Phys. Chem. A Version: 1 119 (19) 4589-4599, issn: 1089-5639, ids: CI6YV, doi: 10.1021/jp510711u, PubMed ID: 25526741
  • Browne, EC, JP Franklin, MR Canagaratna, P Massoli, TW Kirchstetter, DR Worsnop, KR Wilson and JH Kroll (2015), Changes to the Chemical Composition of Soot from Heterogeneous Oxidation Reactions. J. Phys. Chem. A Version: 1 119 (7) 1154-1163, issn: 1089-5639, ids: CB9HI, doi: 10.1021/jp511507d, PubMed ID: 25654760
  • Pusede, SE, TC VandenBoer, JG Murphy, MZ Markovic, CJ Young, PR Veres, JM Roberts, RA Washenfelder, SS Brown, XR Ren, C Tsai, J Stutz, WH Brune, EC Browne, PJ Wooldridge, AR Graham, R Weber, AH Goldstein, S Dusanter, SM Griffith, PS Stevens, BL Lefer and RC Cohen (2015), An Atmospheric Constraint on the NO2 Dependence of Daytime Near-Surface Nitrous Acid (HONO). Environ. Sci. Technol. Version: 1 49 (21) 12774-12781, issn: 0013-936X, ids: CV6BI, doi: 10.1021/acs.est.5b02511, PubMed ID: 26436410
  • Browne, EC, PJ Wooldridge, KE Min and RC Cohen (2014), On the role of monoterpene chemistry in the remote continental boundary layer. Atmos. Chem. Phys. Version: 1 14 (3) 1225-1238, issn: 1680-7316, ids: AC2ZN, doi: 10.5194/acp-14-1225-2014
  • Pusede, SE, DR Gentner, PJ Wooldridge, EC Browne, AW Rollins, KE Min, AR Russell, J Thomas, L Zhang, WH Brune, SB Henry, JP DiGangi, FN Keutsch, SA Harrold, JA Thornton, MR Beaver, JM St Clair, PO Wennberg, J Sanders, X Ren, TC VandenBoer, MZ Markovic, A Guha, R Weber, AH Goldstein and RC Cohen (2014), On the temperature dependence of organic reactivity, nitrogen oxides, ozone production, and the impact of emission controls in San Joaquin Valley, California. Atmos. Chem. Phys. Version: 1 14 (7) 3373-3395, issn: 1680-7316, ids: AF3JO, doi: 10.5194/acp-14-3373-2014
  • Min, KE, SE Pusede, EC Browne, BW LaFranchi, PJ Wooldridge and RC Cohen (2014), Eddy covariance fluxes and vertical concentration gradient measurements of NO and NO2 over a ponderosa pine ecosystem: observational evidence for within-canopy chemical removal of NOx. Atmos. Chem. Phys. Version: 1 14 (11) 5495-5512, issn: 1680-7316, ids: AJ6KO, doi: 10.5194/acp-14-5495-2014
  • VandenBoer, TC, MZ Markovic, JE Sanders, X Ren, SE Pusede, EC Browne, RC Cohen, L Zhang, J Thomas, WH Brune and JG Murphy (2014), Evidence for a nitrous acid (HONO) reservoir at the ground surface in Bakersfield, CA, during CalNex 2010. J. Geophys. Res.-Atmos. Version: 1 119 (14) 9093-9106, issn: 2169-897X, ids: AN2GQ, doi: 10.1002/2013JD020971
  • Worton, DR, JD Surratt, BW LaFranchi, AWH Chan, YL Zhao, RJ Weber, JH Park, JB Gilman, J de Gouw, C Park, G Schade, M Beaver, JM St Clair, J Crounse, P Wennberg, GM Wolfe, S Harrold, JA Thornton, DK Farmer, KS Docherty, MJ Cubison, JL Jimenez, AA Frossard, LM Russell, K Kristensen, M Glasius, JQ Mao, XR Ren, W Brune, EC Browne, SE Pusede, RC Cohen, JH Seinfeld and AH Goldsteint (2013), Observational Insights into Aerosol Formation from Isoprene. Environ. Sci. Technol. Version: 1 47 (20) 11403-11413, issn: 0013-936X, ids: 240UQ, doi: 10.1021/es4011064, PubMed ID: 24004194
  • Browne, EC, KE Min, PJ Wooldridge, E Apel, DR Blake, WH Brune, CA Cantrell, MJ Cubison, GS Diskin, JL Jimenez, AJ Weinheimer, PO Wennberg, A Wisthaler and RC Cohen (2013), Observations of total RONO2 over the boreal forest: NOx sinks and HNO3 sources. Atmos. Chem. Phys. Version: 1 13 (9) 4543-4562, issn: 1680-7316, ids: 144LR, doi: 10.5194/acp-13-4543-2013
  • Min, KE, SE Pusede, EC Browne, BW LaFranchi, PJ Wooldridge, GM Wolfe, SA Harrold, JA Thornton and RC Cohen (2012), Observations of atmosphere-biosphere exchange of total and speciated peroxynitrates: nitrogen fluxes and biogenic sources of peroxynitrates. Atmos. Chem. Phys. Version: 1 12 (20) 9763-9773, issn: 1680-7316, ids: 029BS, doi: 10.5194/acp-12-9763-2012
  • Browne, EC and RC Cohen (2012), Effects of biogenic nitrate chemistry on the NOx lifetime in remote continental regions. Atmos. Chem. Phys. Version: 1 12 (24) 11917-11932, issn: 1680-7316, ids: 058WR, doi: 10.5194/acp-12-11917-2012
  • Rollins, AW, EC Browne, KE Min, SE Pusede, PJ Wooldridge, DR Gentner, AH Goldstein, S Liu, DA Day, LM Russell and RC Cohen (2012), Evidence for NOx Control over Nighttime SOA Formation. Science Version: 1 337 (6099) 1210-1212, issn: 0036-8075, ids: 000UJ, doi: 10.1126/science.1221520, PubMed ID: 22955831
  • Ren, X, JE Sanders, A Rajendran, RJ Weber, AH Goldstein, SE Pusede, EC Browne, KE Min and RC Cohen (2011), A relaxed eddy accumulation system for measuring vertical fluxes of nitrous acid. Atmos. Meas. Tech. Version: 1 4 (10) 2093-2103, issn: 1867-1381, ids: 842JC, doi: 10.5194/amt-4-2093-2011
  • Russell, AR, AE Perring, LC Valin, EJ Bucsela, EC Browne, KE Min, PJ Wooldridge and RC Cohen (2011), A high spatial resolution retrieval of NO2 column densities from OMI: method and evaluation. Atmos. Chem. Phys. Version: 1 11 (16) 8543-8554, issn: 1680-7316, ids: 813YL, doi: 10.5194/acp-11-8543-2011
  • Browne, EC, AE Perring, PJ Wooldridge, E Apel, SR Hall, LG Huey, J Mao, KM Spencer, JM St Clair, AJ Weinheimer, A Wisthaler and RC Cohen (2011), Global and regional effects of the photochemistry of CH3O2NO2: evidence from ARCTAS. Atmos. Chem. Phys. Version: 1 11 (9) 4209-4219, issn: 1680-7316, ids: 764GT, doi: 10.5194/acp-11-4209-2011
  • Wolfe, GM, JA Thornton, NC Bouvier-Brown, AH Goldstein, JH Park, M Mckay, DM Matross, J Mao, WH Brune, BW LaFranchi, EC Browne, KE Min, PJ Wooldridge, RC Cohen, JD Crounse, IC Faloona, JB Gilman, WC Kuster, JA de Gouw, A Huisman and FN Keutsch (2011), The Chemistry of Atmosphere-Forest Exchange (CAFE) Model - Part 2: Application to BEARPEX-2007 observations. Atmos. Chem. Phys. Version: 1 11 (3) 1269-1294, issn: 1680-7316, ids: 721KW, doi: 10.5194/acp-11-1269-2011
  • Ren, X, H Gao, X Zhou, JD Crounse, PO Wennberg, EC Browne, BW LaFranchi, RC Cohen, M Mckay, AH Goldstein and J Mao (2010), Measurement of atmospheric nitrous acid at Blodgett Forest during BEARPEX2007. Atmos. Chem. Phys. Version: 1 10 (13) 6283-6294, issn: 1680-7316, ids: 624VY, doi: 10.5194/acp-10-6283-2010
  • Alvarado, MJ, JA Logan, J Mao, E Apel, D Riemer, D Blake, RC Cohen, KE Min, AE Perring, EC Browne, PJ Wooldridge, GS Diskin, GW Sachse, H Fuelberg, WR Sessions, DL Harrigan, G Huey, J Liao, A Case-Hanks, JL Jimenez, MJ Cubison, SA Vay, AJ Weinheimer, DJ Knapp, DD Montzka, FM Flocke, IB Pollack, PO Wennberg, A Kurten, J Crounse, JM St Clair, A Wisthaler, T Mikoviny, RM Yantosca, CC Carouge and P Le Sager (2010), Nitrogen oxides and PAN in plumes from boreal fires during ARCTAS-B and their impact on ozone: an integrated analysis of aircraft and satellite observations. Atmos. Chem. Phys. Version: 1 10 (20) 9739-9760, issn: 1680-7316, ids: 673LH, doi: 10.5194/acp-10-9739-2010
  • LaFranchi, BW, GM Wolfe, JA Thornton, SA Harrold, EC Browne, KE Min, PJ Wooldridge, JB Gilman, WC Kuster, PD Goldan, JA de Gouw, M Mckay, AH Goldstein, X Ren, J Mao and RC Cohen (2009), Closing the peroxy acetyl nitrate budget: observations of acyl peroxy nitrates (PAN, PPN, and MPAN) during BEARPEX 2007. Atmos. Chem. Phys. Version: 1 9 (19) 7623-7641, issn: 1680-7316, ids: 506MT, doi: 10.5194/acp-9-7623-2009