title: Bringing the ocean into the laboratory to probe the chemical complexity of sea spray aerosol.
abstract: The production, size, and chemical composition of sea spray aerosol (SSA) particles strongly depend on seawater chemistry, which is controlled by physical, chemical, and biological processes. Despite decades of studies in marine environments, a direct relationship has yet to be established between ocean biology and the physicochemical properties of SSA. The ability to establish such relationships is hindered by the fact that SSA measurements are typically dominated by overwhelming background aerosol concentrations even in remote marine environments. Herein, we describe a newly developed approach for reproducing the chemical complexity of SSA in a laboratory setting, comprising a unique ocean-atmosphere facility equipped with actual breaking waves. A mesocosm experiment was performed in natural seawater, using controlled phytoplankton and heterotrophic bacteria concentrations, which showed SSA size and chemical mixing state are acutely sensitive to the aerosol production mechanism, as well as to the type of biological species present. The largest reduction in the hygroscopicity of SSA occurred as heterotrophic bacteria concentrations increased, whereas phytoplankton and chlorophyll-a concentrations decreased, directly corresponding to a change in mixing state in the smallest (60-180 nm) size range. Using this newly developed approach to generate realistic SSA, systematic studies can now be performed to advance our fundamental understanding of the impact of ocean biology on SSA chemical mixing state, heterogeneous reactivity, and the resulting climate-relevant properties.
authors.affiliation: Department of Chemistry and Biochemistry and Scripps Institution of Oceanography, University of California at San Diego, La Jolla, CA 92093, USA. kprather@ucsd.edu
authors.forename: Kimberly A
authors.initials: KA
authors.lastname: Prather
authors.forename: Timothy H
authors.initials: TH
authors.lastname: Bertram
authors.forename: Vicki H
authors.initials: VH
authors.lastname: Grassian
authors.forename: Grant B
authors.initials: GB
authors.lastname: Deane
authors.forename: M Dale
authors.initials: MD
authors.lastname: Stokes
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Demott
authors.forename: Lihini I
authors.initials: LI
authors.lastname: Aluwihare
authors.forename: Brian P
authors.initials: BP
authors.lastname: Palenik
authors.forename: Farooq
authors.initials: F
authors.lastname: Azam
authors.forename: John H
authors.initials: JH
authors.lastname: Seinfeld
authors.forename: Ryan C
authors.initials: RC
authors.lastname: Moffet
authors.forename: Mario J
authors.initials: MJ
authors.lastname: Molina
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Cappa
authors.forename: Franz M
authors.initials: FM
authors.lastname: Geiger
authors.forename: Gregory C
authors.initials: GC
authors.lastname: Roberts
authors.forename: Lynn M
authors.initials: LM
authors.lastname: Russell
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Ault
authors.forename: Jonas
authors.initials: J
authors.lastname: Baltrusaitis
authors.forename: Douglas B
authors.initials: DB
authors.lastname: Collins
authors.forename: Craig E
authors.initials: CE
authors.lastname: Corrigan
authors.forename: Luis A
authors.initials: LA
authors.lastname: Cuadra-Rodriguez
authors.forename: Carlena J
authors.initials: CJ
authors.lastname: Ebben
authors.forename: Sara D
authors.initials: SD
authors.lastname: Forestieri
authors.forename: Timothy L
authors.initials: TL
authors.lastname: Guasco
authors.forename: Scott P
authors.initials: SP
authors.lastname: Hersey
authors.forename: Michelle J
authors.initials: MJ
authors.lastname: Kim
authors.forename: William F
authors.initials: WF
authors.lastname: Lambert
authors.forename: Robin L
authors.initials: RL
authors.lastname: Modini
authors.forename: Wilton
authors.initials: W
authors.lastname: Mui
authors.forename: Byron E
authors.initials: BE
authors.lastname: Pedler
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Ruppel
authors.forename: Olivia S
authors.initials: OS
authors.lastname: Ryder
authors.forename: Nathan G
authors.initials: NG
authors.lastname: Schoepp
authors.forename: Ryan C
authors.initials: RC
authors.lastname: Sullivan
authors.forename: Defeng
authors.initials: D
authors.lastname: Zhao
mesh_terms: D000336:Aerosols / Q000737:chemistry*; D001272:Atmosphere / Q000737:chemistry*; D001419:Bacteria / Q000378:metabolism*; D002734:Chlorophyll / Q000737:chemistry; D000077194:Chlorophyll A; D004463:Ecology; D009791:Oceanography; D009792:Oceans and Seas; D010839:Phytoplankton / Q000378:metabolism*; D012623:Seawater / Q000737:chemistry*
chemical_list: D000336:Aerosols; D002734:Chlorophyll; D000077194:Chlorophyll A
keywords: biologically active; cloud condensation nuclei; clouds; ice nucleation; marine aerosols