title: Sea spray aerosol as a unique source of ice nucleating particles.
abstract: Ice nucleating particles (INPs) are vital for ice initiation in, and precipitation from, mixed-phase clouds. A source of INPs from oceans within sea spray aerosol (SSA) emissions has been suggested in previous studies but remained unconfirmed. Here, we show that INPs are emitted using real wave breaking in a laboratory flume to produce SSA. The number concentrations of INPs from laboratory-generated SSA, when normalized to typical total aerosol number concentrations in the marine boundary layer, agree well with measurements from diverse regions over the oceans. Data in the present study are also in accord with previously published INP measurements made over remote ocean regions. INP number concentrations active within liquid water droplets increase exponentially in number with a decrease in temperature below 0 °C, averaging an order of magnitude increase per 5 °C interval. The plausibility of a strong increase in SSA INP emissions in association with phytoplankton blooms is also shown in laboratory simulations. Nevertheless, INP number concentrations, or active site densities approximated using "dry" geometric SSA surface areas, are a few orders of magnitude lower than corresponding concentrations or site densities in the surface boundary layer over continental regions. These findings have important implications for cloud radiative forcing and precipitation within low-level and midlevel marine clouds unaffected by continental INP sources, such as may occur over the Southern Ocean.
authors.affiliation: Department of Atmospheric Science, Colorado State University, Fort Collins, CO 80523-1371; Paul.Demott@colostate.edu.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: DeMott
authors.affiliation: Department of Atmospheric Science, Colorado State University, Fort Collins, CO 80523-1371;
authors.forename: Thomas C J
authors.initials: TC
authors.lastname: Hill
authors.affiliation: Department of Atmospheric Science, Colorado State University, Fort Collins, CO 80523-1371;
authors.forename: Christina S
authors.initials: CS
authors.lastname: McCluskey
authors.affiliation: Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093; Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92093;
authors.forename: Kimberly A
authors.initials: KA
authors.lastname: Prather
authors.affiliation: Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093;
authors.forename: Douglas B
authors.identifier: 0000-0002-6248-9644
authors.initials: DB
authors.lastname: Collins
authors.affiliation: Center for Atmospheric Particle Studies, Carnegie Mellon University, Pittsburgh, PA 15213;
authors.forename: Ryan C
authors.identifier: 0000-0003-0701-7158
authors.initials: RC
authors.lastname: Sullivan
authors.affiliation: Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093;
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Ruppel
authors.affiliation: Department of Chemistry, University of British Columbia, Vancouver, BC, Canada V6T1Z1;
authors.forename: Ryan H
authors.initials: RH
authors.lastname: Mason
authors.affiliation: Department of Chemistry, University of British Columbia, Vancouver, BC, Canada V6T1Z1;
authors.forename: Victoria E
authors.initials: VE
authors.lastname: Irish
authors.affiliation: Department of Environmental Science, Hankuk University of Foreign Studies, Yongin 449791, South Korea;
authors.forename: Taehyoung
authors.initials: T
authors.lastname: Lee
authors.affiliation: Korea Polar Research Institute, Yeonsu-gu, Incheon 406840, South Korea;
authors.forename: Chung Yeon
authors.initials: CY
authors.lastname: Hwang
authors.affiliation: Korea Polar Research Institute, Yeonsu-gu, Incheon 406840, South Korea;
authors.forename: Tae Siek
authors.identifier: 0000-0001-8025-9431
authors.initials: TS
authors.lastname: Rhee
authors.affiliation: Department of Atmospheric Science, University of Wyoming, Laramie, WY 82071;
authors.forename: Jefferson R
authors.initials: JR
authors.lastname: Snider
authors.affiliation: Handix Scientific, Boulder, CO 80301;
authors.forename: Gavin R
authors.initials: GR
authors.lastname: McMeeking
authors.affiliation: Department of Mechanical and Aeronautical Engineering, Clarkson University, Potsdam, NY 13699;
authors.forename: Suresh
authors.initials: S
authors.lastname: Dhaniyala
authors.affiliation: Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton, NY 11973;
authors.forename: Ernie R
authors.initials: ER
authors.lastname: Lewis
authors.affiliation: Air Quality Processes Research Section, Environment Canada, Toronto, ON, Canada M3H 5T4;
authors.forename: Jeremy J B
authors.initials: JJ
authors.lastname: Wentzell
authors.affiliation: Department of Chemistry, University of Toronto, Toronto, ON, Canada M5S 3H6;
authors.forename: Jonathan
authors.initials: J
authors.lastname: Abbatt
authors.affiliation: Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093;
authors.forename: Christopher
authors.initials: C
authors.lastname: Lee
authors.affiliation: Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093;
authors.forename: Camille M
authors.initials: CM
authors.lastname: Sultana
authors.affiliation: Department of Chemistry, University of Michigan, Ann Arbor, MI 48109; Department of Environmental Health Sciences, University of Michigan, Ann Arbor, MI 48109;
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Ault
authors.affiliation: Department of Environmental Health Sciences, University of Michigan, Ann Arbor, MI 48109;
authors.forename: Jessica L
authors.initials: JL
authors.lastname: Axson
authors.affiliation: Department of Environmental Science, University of Puerto Rico, San Juan, PR 00931;
authors.forename: Myrelis
authors.initials: M
authors.lastname: Diaz Martinez
authors.affiliation: Department of Environmental Science, University of Puerto Rico, San Juan, PR 00931;
authors.forename: Ingrid
authors.initials: I
authors.lastname: Venero
authors.affiliation: Department of Environmental Science, University of Puerto Rico, San Juan, PR 00931;
authors.forename: Gilmarie
authors.initials: G
authors.lastname: Santos-Figueroa
authors.affiliation: Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92093;
authors.forename: M Dale
authors.initials: MD
authors.lastname: Stokes
authors.affiliation: Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92093;
authors.forename: Grant B
authors.initials: GB
authors.lastname: Deane
authors.affiliation: Department of Environmental Science, University of Puerto Rico, San Juan, PR 00931;
authors.forename: Olga L
authors.initials: OL
authors.lastname: Mayol-Bracero
authors.affiliation: Department of Chemistry, University of Iowa, Iowa City, IA 52242;
authors.forename: Vicki H
authors.initials: VH
authors.lastname: Grassian
authors.affiliation: Department of Chemistry, University of Wisconsin, Madison, WI 53706;
authors.forename: Timothy H
authors.initials: TH
authors.lastname: Bertram
authors.affiliation: Department of Chemistry, University of British Columbia, Vancouver, BC, Canada V6T1Z1;
authors.forename: Allan K
authors.initials: AK
authors.lastname: Bertram
authors.affiliation: Ocean Lab, Fishguard Harbour, Goodwick, Pembrokeshire SA64 0DE, United Kingdom;
authors.forename: Bruce F
authors.initials: BF
authors.lastname: Moffett
authors.affiliation: Department of Plant Sciences, University of Wyoming, Laramie, WY 82071.
authors.forename: Gary D
authors.initials: GD
authors.lastname: Franc
keywords: clouds; ice nucleation; marine aerosols