HR: 0800h
AN: A31B-0837    [Abstracts]
TI: Observation of Biogenic Nucleation Events at Low Tide in Nova Scotia, Canada
AU: Allan, J D
EM: james.allan@manchester.ac.uk
AF: University of Manchester, PO Box 88 Manchester, Greater Manchester, M60 1QD United Kingdom
AU: * Hering, S V
EM: susanne@aerosol.us
AF: Aerosol Dynamics, 935 Grayson St, Berkeley, CA 94710 United States
AU: Ogren, J A
EM: john.a.ogren@noaa.gov
AF: CMDL NOAA, 325 Braodway R/C MDL1, Boulder, CO 80305 United States
AU: Jimenez, J
EM: jose.jimenez@colrado.edu
AF: Univestiy of Colorado, UCB 216, Boulder, CO 80309 United States
AB: Evidence of coastal new aerosol particle formation was observed during approximately half of the days of a six-week study period at Chebogue Point, Nova Scotia. This was a rural, ground-based site on a peninsula that was operated as part of the ICARTT project during the summer of 2004. Particle number concentrations, as measured by water- and butanol-based condensation particle counters reached as high as 80,000 cm-3. Mobility size distributions show that most of the periods of high concentration were dominated by particles in the sub-10 nm size range. These high number concentration events coincided with low tide during daylight and are believed to be associated with the oxidation of biogenic iodine emitted from laminaria macroalgae, as has been postulated previously based on measurements at Mace Head, Ireland by O'Dowd and coworkers. The overall profile of particle number concentrations was characterized by bursts of one to three hours duration overlaying a slowly varying background. The events were most intense when the ambient relative humidity values were below 90%. The background aerosol varied from 500 to 5000 cm-3, and correlated with carbon monoxide concentrations, indicative of transport from urban source regions.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005