Fine and coarse particles were collected for eight weeks during the
summer of 1991, at a coastal site (Yaquina Head) and a non-industrial site
(Corvallis) in Western Oregon to characterize the aerosol composition and
evaluate whether the sites are appropriate for sampling "background" marine
air. Concentrations of up to 11 species (S0₄²⁻, NO₃⁻, Cl⁻, Na, Fe, Ni, Pb, Cr, Co,
Sb, and CH₃SO₃H) for 95 samples were determined using four chemical
analysis techniques.
The influences of seasalt and soil dust were identified by analyzing
concentrations of Na and Fe in the aerosol samples. Relative elemental
composition in fine and coarse fractions indicated that the aerosol
composition at Yaquina Head was greatly affected by seasalt. "Seasalt"
enrichment factors (relative to Na) indicated that seasalt is the only source of
Cl⁻ and SO₄²⁻ in coarse particles at Yaquina Head. In contrast, the seasalt
influence was relatively weak at the Corvallis site. "Crustal" enrichment
factors suggested that soil dust was not a major source of Na⁺, Cl⁻, or S0₄²⁻ at
either site.
A simple conceptual model that relies on meteorological conditions was
used to identify sampling periods with long range transport from either
marine or continental areas as well as local influences. This model suggested
that during 61% of the experiment period the aerosols were advected from
marine areas. At Yaquina Head, 52% of the sampling periods are associated
with the "clean" background air (marine air with no local influences). Thus,
Yaquina Head represents a useful location for collecting marine background
air from the Pacific Ocean. The chemical composition of the marine
background air collected at the Yaquina Head site is similar to that for other
remote sites around the world. At Corvallis, "clean" marine background air
can occasionally (21%) be collected even though Corvallis is located 64 km
from the ocean. / Graduation date: 1993
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/28977 |
| Date | 26 June 1992 |
| Creators | Ko, Lih-jong |
| Contributors | Vong, Richard J. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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