Sulfur dioxide (SO<sub>2</sub>) vertical column density measurements by Pandora spectrometer over the Canadian oil sands

Vertical column densities (VCDs) of SO<sub>2</sub> retrieved by a Pandora spectral sun photometer at Fort McKay, Alberta, Canada, from 2013 to 2015 were analysed. The Fort McKay site is located in the Canadian oil sands region, approximately 20 km north of two major SO<sub>2</su...

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Main Authors: V. E. Fioletov, C. A. McLinden, A. Cede, J. Davies, C. Mihele, S. Netcheva, S.-M. Li, J. O'Brien
Format: Article
Language:English
Published: Copernicus Publications 2016-07-01
Series:Atmospheric Measurement Techniques
Online Access:http://www.atmos-meas-tech.net/9/2961/2016/amt-9-2961-2016.pdf
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author V. E. Fioletov
C. A. McLinden
A. Cede
J. Davies
C. Mihele
S. Netcheva
S.-M. Li
J. O'Brien
author_facet V. E. Fioletov
C. A. McLinden
A. Cede
J. Davies
C. Mihele
S. Netcheva
S.-M. Li
J. O'Brien
author_sort V. E. Fioletov
collection DOAJ
description Vertical column densities (VCDs) of SO<sub>2</sub> retrieved by a Pandora spectral sun photometer at Fort McKay, Alberta, Canada, from 2013 to 2015 were analysed. The Fort McKay site is located in the Canadian oil sands region, approximately 20 km north of two major SO<sub>2</sub> sources (upgraders), with total emission of about 45 kt yr<sup>−1</sup>. Elevated SO<sub>2</sub> VCD values were frequently recorded by the instrument, with the highest values of about 9 Dobson Units (DU; DU  =  2.69 × 10<sup>16</sup> molecules cm<sup>−2</sup>). Comparisons with co-located in situ measurements demonstrated that there was a very good correlation between VCDs and surface concentrations in some cases, while in other cases, elevated VCDs did not correspond to high surface concentrations, suggesting the plume was above the ground. Elevated VCDs and surface concentrations were observed when the wind direction was from south to southeast, i.e. from the direction of the two local SO<sub>2</sub> sources. The precision of the SO<sub>2</sub> measurements, estimated from parallel measurements by two Pandora instruments at Toronto, is 0.17 DU. The total uncertainty of Pandora SO<sub>2</sub> VCD, estimated using measurements when the wind direction was away from the sources, is less than 0.26 DU (1<i>σ</i>). Comparisons with integrated SO<sub>2</sub> profiles from concurrent aircraft measurements support these estimates.
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spelling doaj.art-83b2b981794146b19617fa5cd5f048542022-12-22T00:13:56ZengCopernicus PublicationsAtmospheric Measurement Techniques1867-13811867-85482016-07-01972961297610.5194/amt-9-2961-2016Sulfur dioxide (SO<sub>2</sub>) vertical column density measurements by Pandora spectrometer over the Canadian oil sandsV. E. Fioletov0C. A. McLinden1A. Cede2J. Davies3C. Mihele4S. Netcheva5S.-M. Li6J. O'Brien7Environment Canada and Climate Change Canada, Toronto, ON, CanadaEnvironment Canada and Climate Change Canada, Toronto, ON, CanadaNASA Goddard Space Flight Center, Greenbelt, MD, USAEnvironment Canada and Climate Change Canada, Toronto, ON, CanadaEnvironment Canada and Climate Change Canada, Toronto, ON, CanadaEnvironment Canada and Climate Change Canada, Toronto, ON, CanadaEnvironment Canada and Climate Change Canada, Toronto, ON, CanadaEnvironment Canada and Climate Change Canada, Toronto, ON, CanadaVertical column densities (VCDs) of SO<sub>2</sub> retrieved by a Pandora spectral sun photometer at Fort McKay, Alberta, Canada, from 2013 to 2015 were analysed. The Fort McKay site is located in the Canadian oil sands region, approximately 20 km north of two major SO<sub>2</sub> sources (upgraders), with total emission of about 45 kt yr<sup>−1</sup>. Elevated SO<sub>2</sub> VCD values were frequently recorded by the instrument, with the highest values of about 9 Dobson Units (DU; DU  =  2.69 × 10<sup>16</sup> molecules cm<sup>−2</sup>). Comparisons with co-located in situ measurements demonstrated that there was a very good correlation between VCDs and surface concentrations in some cases, while in other cases, elevated VCDs did not correspond to high surface concentrations, suggesting the plume was above the ground. Elevated VCDs and surface concentrations were observed when the wind direction was from south to southeast, i.e. from the direction of the two local SO<sub>2</sub> sources. The precision of the SO<sub>2</sub> measurements, estimated from parallel measurements by two Pandora instruments at Toronto, is 0.17 DU. The total uncertainty of Pandora SO<sub>2</sub> VCD, estimated using measurements when the wind direction was away from the sources, is less than 0.26 DU (1<i>σ</i>). Comparisons with integrated SO<sub>2</sub> profiles from concurrent aircraft measurements support these estimates.http://www.atmos-meas-tech.net/9/2961/2016/amt-9-2961-2016.pdf
spellingShingle V. E. Fioletov
C. A. McLinden
A. Cede
J. Davies
C. Mihele
S. Netcheva
S.-M. Li
J. O'Brien
Sulfur dioxide (SO<sub>2</sub>) vertical column density measurements by Pandora spectrometer over the Canadian oil sands
Atmospheric Measurement Techniques
title Sulfur dioxide (SO<sub>2</sub>) vertical column density measurements by Pandora spectrometer over the Canadian oil sands
title_full Sulfur dioxide (SO<sub>2</sub>) vertical column density measurements by Pandora spectrometer over the Canadian oil sands
title_fullStr Sulfur dioxide (SO<sub>2</sub>) vertical column density measurements by Pandora spectrometer over the Canadian oil sands
title_full_unstemmed Sulfur dioxide (SO<sub>2</sub>) vertical column density measurements by Pandora spectrometer over the Canadian oil sands
title_short Sulfur dioxide (SO<sub>2</sub>) vertical column density measurements by Pandora spectrometer over the Canadian oil sands
title_sort sulfur dioxide so sub 2 sub vertical column density measurements by pandora spectrometer over the canadian oil sands
url http://www.atmos-meas-tech.net/9/2961/2016/amt-9-2961-2016.pdf
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