scholarly journals Low levels of nitryl chloride at ground level: nocturnal nitrogen oxides in the Lower Fraser Valley of British Columbia

2018 ◽  
Vol 18 (9) ◽  
pp. 6293-6315 ◽  
Author(s):  
Hans D. Osthoff ◽  
Charles A. Odame-Ankrah ◽  
Youssef M. Taha ◽  
Travis W. Tokarek ◽  
Corinne L. Schiller ◽  
...  
Keyword(s):  
British Columbia ◽  
Nitrogen Oxides ◽  
Ground Level ◽  
Ambient Air ◽  
Data Set ◽  
Mixing Ratios ◽  
Nitryl Chloride ◽  
Short Period ◽  
Lower Fraser Valley ◽  
Fraser Valley

Abstract. The nocturnal nitrogen oxides, which include the nitrate radical (NO3), dinitrogen pentoxide (N2O5), and its uptake product on chloride containing aerosol, nitryl chloride (ClNO2), can have profound impacts on the lifetime of NOx (= NO + NO2), radical budgets, and next-day photochemical ozone (O3) production, yet their abundances and chemistry are only sparsely constrained by ambient air measurements. Here, we present a measurement data set collected at a routine monitoring site near the Abbotsford International Airport (YXX) located approximately 30 km from the Pacific Ocean in the Lower Fraser Valley (LFV) on the west coast of British Columbia. Measurements were made from 20 July to 4 August 2012 and included mixing ratios of ClNO2, N2O5, NO, NO2, total odd nitrogen (NOy), O3, photolysis frequencies, and size distribution and composition of non-refractory submicron aerosol (PM1). At night, O3 was rapidly and often completely removed by dry deposition and by titration with NO of anthropogenic origin and unsaturated biogenic hydrocarbons in a shallow nocturnal inversion surface layer. The low nocturnal O3 mixing ratios and presence of strong chemical sinks for NO3 limited the extent of nocturnal nitrogen oxide chemistry at ground level. Consequently, mixing ratios of N2O5 and ClNO2 were low (< 30 and < 100 parts-per-trillion by volume (pptv) and median nocturnal peak values of 7.8 and 7.9 pptv, respectively). Mixing ratios of ClNO2 frequently peaked 1–2 h after sunrise rationalized by more efficient formation of ClNO2 in the nocturnal residual layer aloft than at the surface and the breakup of the nocturnal boundary layer structure in the morning. When quantifiable, production of ClNO2 from N2O5 was efficient and likely occurred predominantly on unquantified supermicron-sized or refractory sea-salt-derived aerosol. After sunrise, production of Cl radicals from photolysis of ClNO2 was negligible compared to production of OH from the reaction of O(1D) + H2O except for a short period after sunrise.

scholarly journals Low levels of nitryl chloride: Nocturnal nitrogen oxides in the Lower Fraser Valley of British Columbia

2017 ◽  
Author(s):  
Hans D. Osthoff ◽  
Charles A. Odame-Ankrah ◽  
Youssef M. Taha ◽  
Travis W. Tokarek ◽  
Corinne L. Schiller ◽  
...  
Keyword(s):  
British Columbia ◽  
Nitrogen Oxides ◽  
Measurement Data ◽  
Ambient Air ◽  
Monitoring Site ◽  
Data Set ◽  
Mixing Ratios ◽  
Nitryl Chloride ◽  
Lower Fraser Valley ◽  
Fraser Valley

Abstract. The nocturnal nitrogen oxides, which include the nitrate radical (NO3), dinitrogen pentoxide (N2O5), and its uptake product on chloride containing aerosol, nitryl chloride (ClNO2), can have profound impacts on the lifetime of NOx (= NO + NO2), radical budgets, and next-day photochemical ozone (O3) production, yet their abundances and chemistry are only sparsely constrained by ambient air measurements. Here, we present a measurement data set collected at a routine monitoring site near the Abbotsford International Airport (YXX) located approximately 30 km from the Pacific Ocean in the Lower Fraser Valley (LFV) on the West coast of British Columbia. Measurements were made from July 20 to August 4, 2012, and included mixing ratios of ClNO2, N2O5, NO, NO2, total odd nitrogen (NOy), O3, photolysis frequencies, and size distribution and composition of non-refractory submicron aerosol. At night, O3 was rapidly and often completely removed by dry deposition and by titration with NO of anthropogenic origin and unsaturated biogenic hydrocarbons in a shallow nocturnal inversion surface layer. The low nocturnal O3 mixing ratios and presence of strong chemical sinks for NO3 limited the extent of nocturnal nitrogen oxide chemistry at ground level. Consequently, mixing ratios of N2O5 and ClNO2 were low (

scholarly journals Spatiotemporal Trends in Episodic Ozone Pollution in the Lower Fraser Valley, British Columbia, in Relation to Mesoscale Atmospheric Circulation Patterns and Emissions

2007 ◽  
Vol 46 (10) ◽  
pp. 1631-1644 ◽  
Author(s):  
B. Ainslie ◽  
D. G. Steyn
Keyword(s):  
British Columbia ◽  
Monitoring Network ◽  
Sea Breeze ◽  
Ambient Air ◽  
Mesoscale Circulation ◽  
Ozone Pollution ◽  
Mixing Ratios ◽  
Spatiotemporal Trends ◽  
Lower Fraser Valley ◽  
Fraser Valley

Abstract A cluster analysis of wind measurements from two meteorological stations in the Lower Fraser Valley, British Columbia, Canada, has been performed to identify mesoscale circulation regimes that are common to days on which ozone mixing ratios at one or more measuring stations in the region’s fixed monitoring network exceed the National Ambient Air Quality Objective of 82 ppb. The analysis, using 20 yr of data (1984–2003), identifies the following four regimes: two with morning winds at the coastal Vancouver International Airport (YVR) meteorological station from the northwest direction and two with southerly YVR morning winds. Not all exceedance days are associated with sea-breeze circulations, but days with southerly morning winds have a higher proportion of well-developed sea-breeze circulations. Composite synoptic patterns associated with each regime all show high pressure over the eastern Pacific Ocean with a thermal trough over Washington State and southwestern British Columbia. Composite ozone patterns, corresponding to each mesoscale circulation regime and taken at the hour of maximum ozone concentration, show similar general features, including strong ozone titration in and around the urban source regions and higher values downwind. This suggests that precursor buildup, prior to the exceedance day, plays an important role in the spatial ozone pattern on exceedance days. A simple multiple linear regression of the plume centroid with the number of days elapsed from the start of the analysis period suggests the centroid of the ozone plume has shifted eastward since 1990. There also appears to be a north–south shift in the ozone plume. It is impossible to tell if these shifts are due to changes in emission levels or to changes in spatial emission patterns, because both changes have occurred over the study period.

scholarly journals Supplementary material to "Low levels of nitryl chloride: Nocturnal nitrogen oxides in the Lower Fraser Valley of British Columbia"

2017 ◽  
Author(s):  
Hans D. Osthoff ◽  
Charles A. Odame-Ankrah ◽  
Youssef M. Taha ◽  
Travis W. Tokarek ◽  
Corinne L. Schiller ◽  
...  
Keyword(s):  
British Columbia ◽  
Nitrogen Oxides ◽  
Nitryl Chloride ◽  
Lower Fraser Valley ◽  
Supplementary Material ◽  
Low Levels ◽  
Fraser Valley

Characterization of gaseous nitrogen oxides in the Lower Fraser Valley during Pacific 2001

2004 ◽  
Vol 38 (34) ◽  
pp. 5811-5823 ◽  
Author(s):  
K.L. Hayden ◽  
K.G. Anlauf ◽  
S.-M. Li ◽  
A.M. Macdonald ◽  
J.W. Bottenheim ◽  
...  
Keyword(s):  
Nitrogen Oxides ◽  
Gaseous Nitrogen ◽  
Lower Fraser Valley ◽  
Fraser Valley

The Spatiotemporal Response of Summertime Tropospheric Ozone to Changes in Local Precursor Emissions in the Lower Fraser Valley, British Columbia

2018 ◽  
Vol 56 (5) ◽  
pp. 303-321
Author(s):  
Bruce Ainslie ◽  
Nadya Moisseeva ◽  
Roxanne Vingarzan ◽  
Corinne Schiller ◽  
Douw Steyn ◽  
...  
Keyword(s):  
British Columbia ◽  
Tropospheric Ozone ◽  
Lower Fraser Valley ◽  
Spatiotemporal Response ◽  
Fraser Valley

Core aeration of sand-based putting greens in the Lower Fraser Valley of British Columbia

2007 ◽  
Vol 87 (1) ◽  
pp. 103-111 ◽  
Author(s):  
P. Sorokovsky ◽  
M. Krzic ◽  
M D Novak
Keyword(s):  
British Columbia ◽  
Surface Area ◽  
Management Practices ◽  
Penetration Resistance ◽  
Water Infiltration ◽  
Putting Greens ◽  
Study Objective ◽  
Soil Penetration Resistance ◽  
Lower Fraser Valley ◽  
Fraser Valley

Core aeration, a management practice originally developed for soil-based putting greens, is still commonly used on sand-based greens. The study objective was to determine the effects of core aeration on soil properties of sand-based putting greens in the Lower Fraser Valley of British Columbia. The experiment was laid out as a randomized complete block design with three replications. The study treatments were regular management practices, including core aeration (CA) carried out in spring and late summer, and regular management practices, but no core aeration (NCA). Each core aeration event impacted 5% of the surface area. Treatments with and without core aeration had similar soil organic matter content, root weight density, and soil bulk density. The CA treatment was generally drier than NCA. Water infiltration was greater on CA than NCA, but only for 1 mo following core aeration. Core aeration generally reduced soil penetration resistance within the mat layer relative to treatment without this practice. On both treatments, soil penetration resistance consistently exceeded 4000 kPa below about 13 cm depth preventing deeper root growth. The limited benefits of the low-surface-area-impact core aeration on the maturing sand-based putting greens in a humid maritime climate suggest that this practice might not be worth doing (at a low surface area impact); however, additional, more detailed studies are needed to confirm this. Key words: Turf management, golf course management, soil penetration resistance, water infiltration

scholarly journals In situ measurements of isoprene and monoterpenes within a south-east Asian tropical rainforest

2011 ◽  
Vol 11 (14) ◽  
pp. 6971-6984 ◽  
Author(s):  
C. E. Jones ◽  
J. R. Hopkins ◽  
A. C. Lewis
Keyword(s):  
Tropical Rainforest ◽  
East Asian ◽  
Ground Level ◽  
Ambient Air ◽  
Tropical Rainforests ◽  
Light Conditions ◽  
Mixing Ratios ◽  
Volatile Carbon ◽  
Malaysian Borneo

Abstract. Biogenic volatile organic compounds (BVOCs) emitted from tropical rainforests comprise a substantial fraction of global atmospheric VOC emissions, however there are only relatively limited measurements of these species in tropical rainforest regions. We present observations of isoprene, α-pinene, camphene, Δ-3-carene, γ-terpinene and limonene, as well as oxygenated VOCs (OVOCs) of biogenic origin such as methacrolein, in ambient air above a tropical rainforest in Malaysian Borneo during the Oxidant and Particle Photochemical Processes above a south-east Asian tropical rainforest (OP3) project in 2008. Daytime composition was dominated by isoprene, with an average mixing ratio of the order of ~1 ppb. γ-terpinene, limonene and camphene were the most abundant monoterpenes, with average daytime mixing ratios of 102, 71 and 66 ppt respectively, and with an average monoterpene toisoprene ratio of 0.3 during sunlit hours, compared to 2.0 at night. Limonene and camphene abundances were seen to be related to both temperature and light conditions. In contrast, γ-terpinene emission continued into the late afternoon/evening, under relatively low temperature and light conditions. The contributions of isoprene, monoterpenes and other classes of VOC to the volatile carbon budget and OH reactivity have been summarised for this rainforest location. We observe good agreement between surface and aircraft measurements of boundary layer isoprene and methacrolein above the natural rainforest, suggesting that the ground-level observations are broadly representative of isoprene emissions from this region.

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