HR: 0800h
AN: A51C-0592 [Abstracts]
TI: Diel Variability of Total and Speciated Water-Soluble Inorganic Iodine in PM2.5 Aerosol at a Southern California Coastal Site
AU: * Pszenny, A
EM: alex.pszenny@unh.edu
AF: University of New Hampshire, Institute for the Study of Earth, Oceans and Space, Climate
Change Research Center, Durham, NH 03824-3575, United States
AU: * Pszenny, A
EM: alex.pszenny@unh.edu
AF: Mt. Washington Observatory, Research Department, North Conway, NH 03860-2310,
United States
AU: Cotter, K
EM: kcotter@mountwashington.org
AF: Mt. Washington Observatory, Research Department, North Conway, NH 03860-2310,
United States
AU: Deegan, B
EM: corvus@localnet.com
AF: Mt. Washington Observatory, Research Department, North Conway, NH 03860-2310,
United States
AU: Fischer, E
EM: efischer@atmos.washington.edu
AF: Mt. Washington Observatory, Research Department, North Conway, NH 03860-2310,
United States
AU: Fischer, E
EM: efischer@atmos.washington.edu
AF: Now at: University of Washington, Department of Atmospheric Sciences, Seattle, WA
98195, United States
AU: Johnson, D
EM: djohnson@gso.uri.edu
AF: Rhode Island Nuclear Science Center, 16 Reactor Road, Narragansett, RI 02882, United
States
AB:
PM2.5 aerosol was sampled over nominal 3-hour intervals at the head of Zuma Beach in Malibu, California
(USA) from 6 to 24 October 2006 by filtration at 1.13 m3 min-1 (STP) through 20 x 25 cm cellulose fiber
(Whatman 41) filters that had been rinsed with deionized water (DIW). Exposed filters were removed from support
cartridges as soon as possible after retrieval (usually within 2 hours), immediately sealed in clean polyethylene
bags, and stored frozen until further processing. Following the field campaign one quarter of each filter was
pressed into a pellet (2.0 cm diameter x 0.5 cm thick) and analyzed by neutron activation for total concentrations of
I and several other trace elements.
Our preliminary analyses indicate that sodium and iodine show a clear diel variation characterized by higher
concentrations from late morning to early evening. We hypothesize that this diel variability is related to a
persistent land/sea breeze circulation associated with the nearby coastal region. Other elements are indicative of
variability in other aerosol sources such as soil dust (Al, Mn) and fossil fuel combustion (V). Second quarters are
currently being extracted in DIW and analyzed in two ways: 1) for iodide by ion chromatography, and 2) for
inorganic iodine in higher oxidation states (i.e., V to 0) by chemical reduction with ascorbic acid followed by
determination of iodide by ion chromatography. Results of the trace element and speciated iodine analyses will
be presented.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0365 Troposphere: composition and chemistry
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting