Ambient high-volume (hi-vol) air samples were collected between March 15th and May
30th 2002, at Cheeka Peak Observatory (CPO), located on the tip of the Olympic
Peninsula, Washington State. This sampling campaign was in conjunction with the 2002
Inter-Continental Transport and Chemical Transformation (ITCT 2K2) Campaign and the
Photochemical Ozone Budget of the Eastern North Pacific Atmosphere (PHOEBA2)
experiment, both of which studied the effect of Trans-Pacific transport on the U.S. West
Coast. The anthropogenic semi-volatile organic compounds (SOCs) measured during this
time period included polycyclic aromatic hydrocarbons (PAHs) and various U.S. current-use
and historical-use pesticides. The total PAH concentration ranged from 0.480-4.49
ng/m³, which is comparable to other remote sites throughout the globe. Ten pesticides
(hexachlorobenzene, dacthal, chlorothalonil, heptachlor, trans-nonachlor, cis-nonachlor,
endosulfan I, triallate, trifluralin, and mirex) were also measured and their concentrations
(0.104-57.0 pg/m³) were comparable to other remote sites and less than agricultural areas.
Gas-phase/particle-phase partitioning of SOCs was explored, with a significant
correlation with temperature found for endosulfan I and retene. A possible relationship at CPO of low total suspended particulate (TSP) concentration with the concentration of
non-exchangeable SOCs in the particle phase was found. Principal Component Analysis,
as well as a t-test, showed there were elevated concentrations and a unique pattern of
anthropogenic SOCs measured during possible Trans-Pacific events on March 15th-16th
March 27th-28th and April 22nd-23rd, 2002. These Trans-Pacific events were identified
using the GEOS-CHEM model and 10-day back air trajectories. The potential sources of
these compounds at CPO were determined using diagnostic ratios of their concentrations,
back trajectories calculated using HYSPLIT4, local meteorological conditions, and U.S.
pesticide use data. / Graduation date: 2004
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/30226 |
| Date | 21 April 2004 |
| Creators | Killin, Robert K. |
| Contributors | Simonich, Staci L. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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