Interannual variability of ozone and carbon monoxide at the Whistler high elevation site: 2002–2006

Macdonald, A. M.; Anlauf, K. G.; Leaitch, W. R.; Chan, Elton; Tarasick, D. W.

doi:10.5194/acp-11-11431-2011

Cited by 44 publications

(44 citation statements)

References 66 publications

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“…CO has a tropospheric lifetime of a few months, so the seasonal variations reflect the northern hemisphere seasonal CO background, which is driven by enhanced emission in cold seasons and accelerated oxidation in summer (Logan et al, 1981). Such maxima of CO in spring have been found at other remote sites (e.g., Macdonald et al (2011) and for the Northern Hemisphere in general (Worden et al, 2013). The average O 3 of NATL were 39, 31, and 33 ppbv for spring, summer, and fall, respectively.…”

Section: Transport Patterns and Associated Chemical Signaturesmentioning

confidence: 90%

“…Negative slopes indicating anticorrelation between O 3 and CO were found in winter at a few ground sites (Parrish et al, 1998;Macdonald et al, 2011), which were attributed to titration of O 3 by NO in emissions. Strong vertical mixing carrying air mass from the upper troposphere was also found to cause negative slopes (Fishman and Seiler, 1983).…”

Section: Relationships Of Observed Trace Gasesmentioning

confidence: 99%

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Ten-year chemical signatures associated with long-range transport observed in the free troposphere over the central North Atlantic

Zhang

Owen

Perlinger

et al. 2017

Elementa: Science of the Anthropocene

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Ten-year observations of trace gases at Pico Mountain Observatory (PMO), a free troposphere site in the central North Atlantic, were classified by transport patterns using the Lagrangian particle dispersion model, FLEXPART. The classification enabled identifying trace gas mixing ratios associated with background air and long- range transport of continental emissions, which were defined as chemical signatures. Comparison between the chemical signatures revealed the impacts of natural and anthropogenic sources, as well as chemical and physical processes during long transport,on air composition in the remote North Atlantic. Transport of North American anthropogenic emissions(NA-Anthro) and summertime wildfire plumes (Fire) significantly enhanced CO and O3 at PMO. Summertime CO enhancements caused by NA-Anthro were found to have been decreasing by a rate of 0.67 ± 0.60 ppbv/year in the ten-year period, due possibly to reduction of emissions in North America. Downward mixing from the upper troposphere and stratosphere due to the persistent Azores-Bermuda anticyclone causes enhanced O3 and nitrogen oxides. The d[O3]/d [CO] value was used to investigate O3 sources and chemistry in different transport patterns. The transport pattern affected by Fire had the lowest d [O3]/d [CO], which was likely due to intense CO production and depressed O3 production in wildfire plumes. Slightly enhanced O3 and d [O3]/d [CO] were found in the background air, suggesting that weak downward mixing from the upper troposphere is common at PMO. Enhancements of both butane isomers were found during upslope flow periods, indicating contributions from local sources. The consistent ratio of butane isomers associated with the background air and NA-anthro implies no clear difference in the oxidation rates of the butane isomers during long transport. Based on observed relationships between non-methane hydrocarbons, the averaged photochemical age of the air masses at PMO was estimated to be 11 ± 4 days.

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Section: Transport Patterns and Associated Chemical Signaturesmentioning

confidence: 90%

Section: Relationships Of Observed Trace Gasesmentioning

confidence: 99%

Ten-year chemical signatures associated with long-range transport observed in the free troposphere over the central North Atlantic

Zhang

Owen

Perlinger

et al. 2017

Elementa: Science of the Anthropocene

View full text Add to dashboard Cite

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“…Simulations were performed for two 4-month periods, summer and winter 2006, and each includes a 1-month spin-up period. Chemical boundary conditions were prepared for the outer domain from ozonesonde measurements, satellite observations and ground measurements at Whistler, along the West Coast of British Columbia (MacDonald et al 2011). Ozone boundary conditions make use of a monthly 3-D climatology (Logan 1999).…”

Section: Regional Air Quality Model Descriptionmentioning

confidence: 99%

Toxic volatile organic air pollutants across Canada: multi-year concentration trends, regional air quality modelling and source apportionment

Stroud¹,

Zaganescu²,

Chen

et al. 2015

J Atmos Chem

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A Unified Regional Air-quality Modelling System, AURAMS, was expanded to predict six toxic volatile organic compounds (VOCs) within a continental domain and two nested domains covering eastern and western Canada. The model predictions were evaluated against Environment Canada's National Air Pollution Surveillance (NAPS) data set to assess the predictive capability of the model at daily and seasonal time scales. The predictions were also evaluated with satellite-derived column total maps for formaldehyde, carbon monoxide, and nitrogen dioxide. In general, the model showed fair to good predictive skill in terms of both correlation (R) and normalized mean bias (NMB) for benzene (R = 0.53 NMB = 26 %), formaldehyde (R = 0.73, NMB = −15 %) and acetaldehyde (R = 0.55, NMB = 29 %). For the other toxics VOCs, the model showed less predictive skill in the order 1,2,4-trimethylbenzene (R = 0.50, NMB = −41 %), 1,3-butadiene (R = 0.26, NMB = 40 %) and acrolein (R = 0.052, NMB = −51 %). The goal of this study was to apply an air quality model to assess the contribution of mobile sources to ambient levels of toxic VOCs at urban locations across Canada. The mobile source contribution varied in a complex manner for each species for different regions. For benzene and 1,2,4-trimethylbenzene, the mobile source contribution was in the range 40-65 % for major Canadian cities. The model predicted considerably lower

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“…He et al, 2011;Hocking et al, 2007) and the inter-continental transport of tropospheric ozone and its precursor species (Oltmans et al, 2006(Oltmans et al, , 2010. Canadian ozonesondes have also provided essential information on the nature of Arctic stratospheric ozone loss (Manney et al, 2011;Fioletov et al, 1997;Kerr et al, 1993), of Arctic surface depletion events Bottenheim et al, 2002), and of the global circulation of ozone (Lin et al, 2015;Bönisch et al, 2011;Pan et al, 2009), as well as of tropospheric sources and budgets (Emmons et al, 2015;Parrington et al, 2012;Walker et al, 2010Walker et al, , 2012Macdonald et al, 2011;Thompson et al, 2007;Tarasick et al, 2007). The time series of ozone soundings from Canadian stations comprise some of the longest records of vertical ozone profile measurement that exist, as well as the only time series of measurements in the free troposphere over Canada.…”

Section: Introductionmentioning

confidence: 99%

A re-evaluated Canadian ozonesonde record: measurements of the vertical distribution of ozone over Canada from 1966 to 2013

et al. 2016

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Abstract. In Canada routine ozone soundings have been carried at Resolute Bay since 1966, making this record the longest in the world. Similar measurements started in the 1970s at three other sites, and the network was expanded in stages to 10 sites by 2003. This important record for understanding long-term changes in tropospheric and stratospheric ozone has been re-evaluated as part of the SPARC/IO 3 C/IGACO-O 3 /NDACC (SI 2 N) initiative. The Brewer-Mast sonde, used in the Canadian network until 1980, is different in construction from the electrochemical concentration cell (ECC) sonde, and the ECC sonde itself has also undergone a variety of minor design changes over the period 1980-2013. Corrections have been made for the estimated effects of these changes to produce a more homogeneous data set.The effect of the corrections is generally modest. However, the overall result is entirely positive: the comparison with co-located total ozone spectrometers is improved, in terms of both bias and standard deviation, and trends in the bias have been reduced or eliminated. An uncertainty analysis (including the additional uncertainty from the corrections, where appropriate) has also been conducted, and the altitudedependent estimated uncertainty is included with each revised profile.The resulting time series show negative trends in the lower stratosphere of up to 5 % decade −1 for the period 1966-2013. Most of this decline occurred before 1997, and linear trends for the more recent period are generally not significant. The time series also show large variations from year to year. Some of these anomalies can be related to cold winters (in the Arctic stratosphere) or changes in the Brewer-Dobson circulation, which may thereby be influencing trends.In the troposphere, trends for the 48-year period are small and for the most part not significant. This suggests that ozone levels in the free troposphere over Canada have not changed significantly in nearly 50 years.

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Interannual variability of ozone and carbon monoxide at the Whistler high elevation site: 2002–2006

Abstract: Abstract. In spring 2002, an atmospheric measurement site was established at the peak of Whistler Mountain in British Columbia, Canada to measure trace gases, particle chemistry and physics, and meteorology. This paper uses continuous measurements from

Cited by 44 publications

References 66 publications

Ten-year chemical signatures associated with long-range transport observed in the free troposphere over the central North Atlantic

Ten-year chemical signatures associated with long-range transport observed in the free troposphere over the central North Atlantic

Toxic volatile organic air pollutants across Canada: multi-year concentration trends, regional air quality modelling and source apportionment

A re-evaluated Canadian ozonesonde record: measurements of the vertical distribution of ozone over Canada from 1966 to 2013

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