title: A Decade of Change in NO2 and SO2 over the Canadian Oil Sands As Seen from Space.
abstract: A decade (2005-2014) of observations from the Ozone Monitoring Instrument (OMI) were used to examine trends in nitrogen dioxide (NO2) and sulfur dioxide (SO2) over a large region of western Canada and the northern United States, with a focus on the Canadian oil sands. In the oil sands, primarily over an area of intensive surface mining, NO2 tropospheric vertical column densities (VCDs) are seen to be increasing by as much as 10%/year, with the location of the largest trends in a newly developing NO2 "lobe" well removed from surface monitoring stations. SO2 VCDs in the oil sands have remained approximately constant. The only other significant increase in the region was seen in NO2 over Bakken gas fields in North Dakota which showed increases of up to 5%/yr. By contrast, other locations in the region show substantial declines in both pollutants, providing strong evidence to the efficacy of environmental pollution control measures implemented by both nations. The OMI-derived trends were found to be consistent with those from the Canadian surface monitoring network, although in the case of SO2, it was necessary to apply a correction in order to remove the residual signal from volcanic eruptions present in the OMI data.
authors.affiliation: Air Quality Research Division, Environment and Climate Change Canada , Toronto, Ontario M3H 5T4, Canada.
authors.forename: Chris A
authors.initials: CA
authors.lastname: McLinden
authors.affiliation: Air Quality Research Division, Environment and Climate Change Canada , Toronto, Ontario M3H 5T4, Canada.
authors.forename: Vitali
authors.initials: V
authors.lastname: Fioletov
authors.affiliation: Atmospheric Chemistry and Dynamics Laboratory, NASA Goddard Space Flight Center , Greenbelt, Maryland 20771, United States.
authors.forename: Nickolay A
authors.initials: NA
authors.lastname: Krotkov
authors.affiliation: Atmospheric Chemistry and Dynamics Laboratory, NASA Goddard Space Flight Center , Greenbelt, Maryland 20771, United States.|Earth System Science Interdisciplinary Center, University of Maryland College Park, Maryland 20742, United States.
authors.forename: Can
authors.initials: C
authors.lastname: Li
authors.affiliation: Royal Netherlands Meteorological Institute (KNMI) , De Bilt 3731 GA, The Netherlands.|Department of Meteorology and Air Quality, Wageningen University , Wageningen 6708 PB, The Netherlands.
authors.forename: K Folkert
authors.initials: KF
authors.lastname: Boersma
authors.affiliation: Air Quality Research Division, Environment and Climate Change Canada , Toronto, Ontario M3H 5T4, Canada.
authors.forename: Cristen
authors.initials: C
authors.lastname: Adams
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000032:analysis*; D002170:Canada; D004784:Environmental Monitoring / Q000379:methods*; D009585:Nitrogen Dioxide / Q000032:analysis*; D009658:North Dakota; D061329:Oil and Gas Fields; D013458:Sulfur Dioxide / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D013458:Sulfur Dioxide; D009585:Nitrogen Dioxide