title: Absorption and scattering of 1.06 microm laser radiation from oceanic aerosols.
abstract: The absorption and scattering of oceanic aerosols are characterized using low- and high-power lasers in the near IR (1.064 microm). The imaginary part of the refractive index of sea salt inferred from low-power absorption measurements is 200x less than the commonly accepted value from the literature. The measured absorption coefficients of natural and artificial saltwater are within 5% of the absorption of pure water (0.14 cm(-1)). High-power aerosol experiments are consistent with low-power liquid absorption measurements, which yield comparable absorption coefficients for pure water and saltwater. High-power illumination of test aerosols (CuSO(4).5H(2)O) with an absorption coefficient alpha > or = 0.19 cm(-1) and a dwell time of 100 ms results in a consistent reduction in scattering from the aerosol column. The high-power laser scattering measurements are in good agreement with the theory, which accounts for the absorption, heating, and vaporization of the water-based aerosols. The measured absorption of oceanic aerosols in the laboratory is much less than the literature values at 1.064 microm and should result in reduced heating and thermal blooming in open ocean atmospheres.
authors.affiliation: Plasma Physics Division, Naval Research Laboratory, Washington, D.C. 20375, USA. Rich.Fischer@nrl.navy.mil
authors.forename: Richard
authors.initials: R
authors.lastname: Fischer
authors.forename: Antonio
authors.initials: A
authors.lastname: Ting
authors.forename: Gregory
authors.initials: G
authors.lastname: DiComo
authors.forename: John
authors.initials: J
authors.lastname: Prosser
authors.forename: Joseph
authors.initials: J
authors.lastname: Peñano
authors.forename: Bahman
authors.initials: B
authors.lastname: Hafizi
authors.forename: Phillip
authors.initials: P
authors.lastname: Sprangle