T
Timothy B. Onasch
Researcher at Boston College
Publications - 213
Citations - 23970
Timothy B. Onasch is an academic researcher from Boston College. The author has contributed to research in topics: Aerosol & Particle. The author has an hindex of 70, co-authored 206 publications receiving 20924 citations. Previous affiliations of Timothy B. Onasch include University of Colorado Boulder.
Papers
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Journal ArticleDOI
Evolution of Organic Aerosols in the Atmosphere
Jose L. Jimenez,Manjula R. Canagaratna,Neil M. Donahue,André S. H. Prévôt,Qi Zhang,Jesse H. Kroll,Peter F. DeCarlo,James Allan,Hugh Coe,Nga L. Ng,Allison C. Aiken,Kenneth S. Docherty,Ingrid M. Ulbrich,Andrew P. Grieshop,Allen L. Robinson,Jonathan Duplissy,Jared D. Smith,Kevin R. Wilson,V. A. Lanz,Christoph Hueglin,Yele Sun,Yele Sun,Jian Tian,Ari Laaksonen,Tomi Raatikainen,Tomi Raatikainen,J. Rautiainen,Petri Vaattovaara,Mikael Ehn,Markku Kulmala,Markku Kulmala,Jason Tomlinson,Don R. Collins,Michael J. Cubison,Edward J. Dunlea,J. A. Huffman,Timothy B. Onasch,M. R. Alfarra,Paul I. Williams,Keith Bower,Yutaka Kondo,Johannes Schneider,Frank Drewnick,Stephan Borrmann,S. Weimer,Kenneth L. Demerjian,D. Salcedo,L. Cottrell,Robert J. Griffin,Akinori Takami,Takao Miyoshi,Shiro Hatakeyama,Akio Shimono,J. Y. Sun,Y. M. Zhang,Katja Dzepina,Joel R. Kimmel,Donna Sueper,J. T. Jayne,Scott C. Herndon,A. Trimborn,Leah R. Williams,Ezra C. Wood,Ann M. Middlebrook,Charles E. Kolb,Urs Baltensperger,Douglas R. Worsnop +66 more
TL;DR: A unifying model framework describing the atmospheric evolution of OA that is constrained by high–time-resolution measurements of its composition, volatility, and oxidation state is presented, which can serve as a basis for improving parameterizations in regional and global models.
Journal ArticleDOI
Ubiquity and dominance of oxygenated species in organic aerosols in anthropogenically-influenced Northern Hemisphere midlatitudes
Qi Zhang,Jose L. Jimenez,Manjula R. Canagaratna,James Allan,Hugh Coe,Ingrid M. Ulbrich,M. R. Alfarra,Akinori Takami,Ann M. Middlebrook,Yele Sun,Katja Dzepina,Edward J. Dunlea,Kenneth S. Docherty,Peter F. DeCarlo,D. Salcedo,Timothy B. Onasch,J. T. Jayne,Takao Miyoshi,A. Shimono,Shiro Hatakeyama,Nobuyuki Takegawa,Yutaka Kondo,Johannes Schneider,Frank Drewnick,Stephan Borrmann,Silke Weimer,Kenneth L. Demerjian,Paul I. Williams,Keith Bower,Roya Bahreini,Roya Bahreini,L. Cottrell,Robert J. Griffin,J. Rautiainen,J. Y. Sun,Yaping Zhang,D. R. Worsnop +36 more
TL;DR: In this article, organic aerosol data acquired by the AMS in 37 field campaigns were deconvolved into hydrocarbon-like OA (HOA) and several types of oxygenated OA components.
Journal ArticleDOI
Chemical and microphysical characterization of ambient aerosols with the aerodyne aerosol mass spectrometer
Manjula R. Canagaratna,John T. Jayne,Jose L. Jimenez,James Allan,M. R. Alfarra,Qi Zhang,Timothy B. Onasch,Frank Drewnick,Hugh Coe,Ann M. Middlebrook,A. E. Delia,Leah R. Williams,A. Trimborn,M. J. Northway,Peter F. DeCarlo,Charles E. Kolb,Paul Davidovits,Douglas R. Worsnop +17 more
TL;DR: A detailed discussion of the strengths and limitations of the AMS measurement approach is presented and how the measurements are used to characterize particle properties are reviewed to highlight the different applications of this instrument.
Journal ArticleDOI
O/C and OM/OC Ratios of Primary, Secondary, and Ambient Organic Aerosols with High-Resolution Time-of-Flight Aerosol Mass Spectrometry
Allison C. Aiken,Peter F. DeCarlo,Jesse H. Kroll,Douglas R. Worsnop,J. Alex Huffman,Kenneth S. Docherty,Ingrid M. Ulbrich,Claudia Mohr,Joel R. Kimmel,Donna Sueper,Yele Sun,Qi Zhang,A. Trimborn,M. J. Northway,Paul J. Ziemann,Manjula R. Canagaratna,Timothy B. Onasch,M. Rami Alfarra,André S. H. Prévôt,Josef Dommen,Jonathan Duplissy,A. Metzger,Urs Baltensperger,Jose L. Jimenez +23 more
TL;DR: A recently developed method to rapidly quantify the elemental composition of bulk organic aerosols (OA) using a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) is improved and applied to ambient measurements.
Journal ArticleDOI
A generalised method for the extraction of chemically resolved mass spectra from aerodyne aerosol mass spectrometer data
James Allan,A. E. Delia,Hugh Coe,Keith Bower,M. Rami Alfarra,Jose L. Jimenez,Ann M. Middlebrook,Frank Drewnick,Timothy B. Onasch,Manjula R. Canagaratna,John T. Jayne,Douglas R. Worsnop +11 more
TL;DR: A generalised method for deconvolution of mass spectral data from the aerodyne aerosol mass spectrometer (AMS) is presented in this paper, which is designed to arithmetically separate the raw data into partial mass spectra for distinct chemical species.