Principal component analysis of summertime ground site measurements in the Athabasca oil sands with a focus on analytically unresolved intermediate-volatility organic compounds
<p>In this paper, measurements of air pollutants made at a ground site near Fort McKay in the Athabasca oil sands region as part of a multi-platform campaign in the summer of 2013 are presented. The observations included measurements of selected volatile organic compounds (VOCs) by a gas chrom...
| Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-12-01
|
| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://www.atmos-chem-phys.net/18/17819/2018/acp-18-17819-2018.pdf |
| Summary: | <p>In this paper, measurements of air pollutants made at a ground site near Fort
McKay in the Athabasca oil sands region as part of a multi-platform campaign
in the summer of 2013 are presented. The observations included measurements
of selected volatile organic compounds (VOCs) by a gas chromatograph–ion
trap mass spectrometer (GC-ITMS). This instrument observed a large,
analytically unresolved hydrocarbon peak (with a retention index between 1100
and 1700) associated with intermediate-volatility organic compounds (IVOCs).
However, the activities or processes that contribute to the release of these
IVOCs in the oil sands region remain unclear.</p>
<p>Principal component analysis (PCA) with varimax rotation was applied to
elucidate major source types impacting the sampling site in the summer of
2013. The analysis included 28 variables, including concentrations of total
odd nitrogen (<span class="inline-formula">NO<sub><i>y</i></sub></span>), carbon dioxide (<span class="inline-formula">CO<sub>2</sub></span>), methane
(<span class="inline-formula">CH<sub>4</sub></span>), ammonia (<span class="inline-formula">NH<sub>3</sub></span>), carbon monoxide (CO), sulfur
dioxide (<span class="inline-formula">SO<sub>2</sub></span>), total reduced-sulfur compounds (TRSs), speciated
monoterpenes (including <span class="inline-formula"><i>α</i></span>- and <span class="inline-formula"><i>β</i></span>-pinene and limonene),
particle volume calculated from measured size distributions of particles less
than 10 and 1 <span class="inline-formula">µ</span>m in diameter (PM<span class="inline-formula"><sub>10−1</sub></span> and PM<span class="inline-formula"><sub>1</sub></span>),
particle-surface-bound polycyclic aromatic hydrocarbons (pPAHs), and aerosol
mass spectrometer composition measurements, including refractory black carbon
(rBC) and organic aerosol components. The PCA was complemented by bivariate
polar plots showing the joint wind speed and direction dependence of air
pollutant concentrations to illustrate the spatial distribution of sources in
the area. Using the 95 % cumulative percentage of variance criterion, 10
components were identified and categorized by source type. These included
emissions by wet tailing ponds, vegetation, open pit mining operations,
upgrader facilities, and surface dust. Three components correlated with
IVOCs, with the largest associated with surface mining and likely caused
by the unearthing and processing of raw bitumen.</p> |
|---|---|
| ISSN: | 1680-7316 1680-7324 |