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Single-particle insights into the influence of biological activity on sea spray aerosol mixing-state. Dr. Cassandra J. Gaston March 18, 2014. Aerosol Time-of-Flight Mass Spectrometer (ATOFMS). Inlet. Ellipsoidal Mirrors. Particle Inlet. Scattering Lasers (532 nm). Particle Sizing. PMT.
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Single-particle insights into the influence of biological activity on sea spray aerosol mixing-state Dr. Cassandra J. Gaston March 18, 2014
Aerosol Time-of-Flight Mass Spectrometer (ATOFMS) Inlet Ellipsoidal Mirrors Particle Inlet Scattering Lasers (532 nm) Particle Sizing PMT Reflectron + ions - ions Particle Composition Nd:YAG Laser (266 nm) Detectors Size and Chemistry of SingleParticles in real-time Gard, E. et al. (1997)Anal. Chem, 69, 4083-4091.
Chemical Fingerprints of Particle Sources and Age Atmospheric processing of particles from different sources in real-time HNO3, N2O5 HCl, ClNO2 Fresh SS Reacted SS
Marine Organic Material and Sea Spray Aerosol Low Biological Activity High Biological Activity Sea Salt Sea Salt + Organic Material Sea Salt (NaCl) Organic Material Organic enrichment in ejected aerosol compared to seawater due to biological activity How are organics mixed in sea spray? How will this affect water uptake and cloud formation? Microorganisms Bigg, E.K. (2007) Environ. Chem., 4 (3), 155-161 Facchini, M.C. et al. (2008) Geophys. Res. Lett., 35, L17814, doi:10.1029/2008GL034210 Hawkins, L.N. & Russell, L.M. (2010) Advances in Meteorology, doi:10.1155/2010/612132 Meskhidze , N. & Nenes, A. (2006) Science, 314 (5804), 1419-1423 O’Dowd, C.D. et al. (2004) Nature, 431 (7009), 676-680
Observations of Unique Ocean-Derived Particles • Shipboard measurements: INDOEX (Indian Ocean) and ACE-Asia (Pacific Ocean) • Coastal measurements: CIFEX (N. California Coast) Gaston, C.J. et al. (2011) J. Geophys. Res., 116, D18310, doi:10.1029/2010JD015289
Evidence for a Biological Source for Mg-type Particles Mg-type particles associated with proxies for marine biological activity Gaston, C.J. et al. (2011) J. Geophys. Res., 116, D18310, doi:10.1029/2010JD015289
Potential Sources for Mg-type Particles Mg2+ Mg2+ Mg2+ Mg2+ Sea Salt (NaCl) • Potential role of exopolymeric material on atmospheric chemistry • Mg enrichment on particle surface could affect trace gas uptake and cloud formation Mg2+ Mg Mg Mg Mg Mg2+ Mg2+ Mg Mg Mg2+ Casillas-Ituarte, N.N. (2010) PNAS, 107, 6616-6621 Leck, C. & Bigg, E.K. (2005) Tellus,57, 305-316 Orellana, M.V. et al. (2011) PNAS,103, 13612-13617 Wells, M.L. (1998) Nature, 391, 530-531
Conclusions: How Does Biological Activity Impact Sea Spray Aerosol Chemistry? • Ambient data shows sea spray particles enriched in organic and inorganic compounds (Mg-type particles) • Mg-type particles provide insight into single-particle diversity of sea spray aerosol influenced by biological activity • Implications for parameterizing sea spray aerosol in climate models
Acknowledgments • Joel Thornton Funding • Kim Prather -NSF • Thornton Group -California Air • Prather Group Resources Board • NOAA/PMEL • Tim Bates • Trish Quinn Thank you for listening!