title: Non-linear photochemical pathways in laser-induced atmospheric aerosol formation.
abstract: We measured the chemical composition and the size distribution of aerosols generated by femtosecond-Terawatt laser pulses in the atmosphere using an aerosol mass spectrometer (AMS). We show that nitric acid condenses in the form of ammonium nitrate, and that oxidized volatile organics also contribute to particle growth. These two components account for two thirds and one third, respectively, of the dry laser-condensed mass. They appear in two different modes centred at 380 nm and 150 nm. The number concentration of particles between 25 and 300 nm increases by a factor of 15. Pre-existing water droplets strongly increase the oxidative properties of the laser-activated atmosphere, substantially enhancing the condensation of organics under laser illumination.
authors.affiliation: Université de Genève, GAP-Biophotonics, Chemin de Pinchat 22, CH-1211 Geneva 4, Switzerland.
authors.forename: Denis
authors.initials: D
authors.lastname: Mongin
authors.affiliation: Paul Scherrer Institute, Laboratory of Atmospheric Chemistry, CH-5232 Villigen, Switzerland.
authors.forename: Jay G
authors.initials: JG
authors.lastname: Slowik
authors.affiliation: Université de Genève, GAP-Biophotonics, Chemin de Pinchat 22, CH-1211 Geneva 4, Switzerland.
authors.forename: Elise
authors.initials: E
authors.lastname: Schubert
authors.affiliation: Université de Genève, GAP-Biophotonics, Chemin de Pinchat 22, CH-1211 Geneva 4, Switzerland.|Max-Born-Institut, Max-Born-Strasse 2A, 12489 Berlin, Germany.
authors.forename: Jean-Gabriel
authors.initials: JG
authors.lastname: Brisset
authors.affiliation: Université de Genève, GAP-Biophotonics, Chemin de Pinchat 22, CH-1211 Geneva 4, Switzerland.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Berti
authors.affiliation: Université de Genève, GAP-Biophotonics, Chemin de Pinchat 22, CH-1211 Geneva 4, Switzerland.
authors.forename: Michel
authors.initials: M
authors.lastname: Moret
authors.affiliation: Paul Scherrer Institute, Laboratory of Atmospheric Chemistry, CH-5232 Villigen, Switzerland.
authors.forename: André S H
authors.initials: AS
authors.lastname: Prévôt
authors.affiliation: Paul Scherrer Institute, Laboratory of Atmospheric Chemistry, CH-5232 Villigen, Switzerland.
authors.forename: Urs
authors.initials: U
authors.lastname: Baltensperger
authors.affiliation: Université de Genève, GAP-Non-linear, Chemin de Pinchat 22, CH-1211 Geneva 4, Switzerland.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Kasparian
authors.affiliation: Université de Genève, GAP-Biophotonics, Chemin de Pinchat 22, CH-1211 Geneva 4, Switzerland.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Wolf