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Airborne LIDAR measurements of aerosol and ozone

Informal Lunchtime Atmospheric Chemistry Discussion Series
Presented by:  Monika Aggarwal, Graduate Student @ Prof. Whiteway
Tuesday, Feb. 17th, Noon-1PM, 317 Petrie

Description:
Lidar measurements of ozone and aerosol were conducted from a Twin Otter
aircraft above northern Alberta. The field campaign was carried out with a total
of five flights, during the period between August 22 and August 26, 2013.
Significant amounts of aerosol were observed within the boundary layer,
up to a height of 1.1 km above ground level, but the ozone concentration
remained at or below background levels (40 ppbv). On August 24th the lidar
observed a separated layer of aerosol above the boundary layer, at a height
of 1.8 km above ground level, in which the ozone mixing ratio increased
to 70 ppbv. Backward trajectory calculations revealed that the air
containing this separated aerosol layer had passed over an area of forest fires.
Directly below the layer of forest fire smoke, in the pollution, the
measured ozone mixing ratio was lower than the background levels (<35 ppbv).

Laboratory Studies of Carbon Kinetic Isotope Effects on the Production Mechanism of Particulate Phenolic Compounds Formed by Toluene Photooxidation: A Tool to Constrain Reaction Pathways

Satoshi Irei, Jochen Rudolph, Lin Huang, Janeen Auld, Fabrice Collin and Donald Hastie

The Journal of Physical Chemistry A, 2015, 119 (1), pp. 5-13, DOI: 10.1021/jp5104609.
Abstract:

In this study, we examined compound-specific stable carbon isotope ratios for phenolic compounds in secondary organic aerosol (SOA) formed by photooxidation of isotope-label-free toluene. SOA generated by photooxidation of toluene using a continuous-flow reactor and an 8 m(3) indoor smog chamber was collected on filters, which were extracted with acetonitrile for compound-specific analysis. Eight phenolic compounds were identified in the extracts using a gas chromatograph coupled with a mass spectrometer, and their compound-specific stable carbon isotope ratios were determined using a gas chromatograph coupled with a combustion furnace followed by an isotope ratio mass spectrometer. The majority of products, including methylnitrophenols and methylnitrocatechols, were isotopically depleted by 5-6‰ compared to the initial isotope ratio of toluene, whereas the isotope ratio for 4-nitrophenol remained identical to that of toluene. On the basis of the reaction mechanisms proposed in previous reports, stable carbon isotope ratios of these products were calculated. By comparing the observed isotope ratios with the predicted isotope ratios, we explored possible production pathways for the particulate phenolic compounds.

Notice of Public Lecture: Amanda Jameer – October 31, 2014

Faculty of Graduate Studies Graduate Programme in Chemistry
ORAL EXAMINATION PROSPECTUS

Amanda Jameer

A Candidate for the Degree of Master of Science

Title of Thesis:

Evaluating the utility of a positive-ion atmospheric pressure chemical ionization mass spectrometer ((+) APCI-MS/MS) at detecting organic peroxides during β-pinene ozonolysis experiments

Public Talk: Friday, October 31, 10:00 - 10:45 am., Room 317 Petrie,
Oral Examination: 11:00 am, CAC, 006A Steacie

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Career Development Symposium

The Career Development Symposium will take place May 21st – 22nd 2014, Life Science Building, Rooms 105 & 106, York University. It is an opportunity for science and engineering graduate students to network with professionals in academia, industry and government, as well as to learn and build critical skills through panels of experts and engaging workshops necessary for success in their future career ambitions.

For more information and registration, click here.

Isotope ratio studies of atmospheric organic compounds

Dr. Jochen Rudolph is co-author of Isotope ratio studies of atmospheric organic compounds: Principles, methods, applications and potential published in the International Journal of Mass Spectrometry, March 2014.

Authors: Iulia Gensch, Astrid Kiendler-Scharr and Jochen Rudolph

Abstract: In the atmosphere, both gas and particle phase organic trace compounds (OTC) have multiple effects on air quality and climate. Gaps exist in a fundamental understanding of the sources and sinks of organics and thus, knowledge needed to steer regulatory purposes is far from complete. Isotopes provide specific “fingerprints” in OTC. These fingerprints result from the isotopic composition at emission, as well as from chemical and physical processes in the atmosphere. Compound specific isotope ratio mass spectrometry (IRMS) in atmospheric OTC is therefore a promising tool to improve our understanding of sources and the atmospheric fate of OTC. Due to analytical challenges originating from the small sample amounts and a huge variety of physical and chemical properties of OTC present in the atmosphere, such measurements are not routinely performed. We present an overview of basic concepts as well as instrumental and measurement procedures used for compound specific IRMS in atmospheric OTC. Concepts for the interpretation of ambient observations are reviewed together with available literature data on source specific and ambientδ13C values of gas and particle phase OTC. Full deployment of the IRMS potential in future atmospheric studies will depend on the availability of laboratory kinetic data. Further method developments, such as increasing sensitivity and accuracy, as well as techniques for simultaneous isotope ratio measurement of multiple atoms are expected to further extend the potential use of isotope ratios for studies of atmospheric OTC.

Oil Sands Intensive Monitoring Campaign, Fort McMurray

 

Prof. McLaren and two students on Oil Sands Campaign 2013

Zoe Davis, Akshay Lobo and Robert McLaren in front of the NRC Convair aircraft.

Members of CAC (Zoe Davis, Akshay Lobo, Robert McLaren) are participating in the 2013 Oil Sands Intensive Monitoring Campaign based out of Fort McMurray, Alberta, organized by Environment Canada.  On Sept 5, Zoe Davis and Prof. McLaren will be aboard NRC's Convair aircraft "Research 9". The flight's mission includes satellite validation (TES) for CO and NH3 in the oil sands region as well as studying the transformation of industrial pollution plumes as they are carried downwind of the oil sands region north of Forth McMurray.  The mission will take them west from Alberta into Saskatchewan and back. In addition to aircraft measurements of air quality, other air measurements are being taken by members of the CAC at a ground site, AMS13, in the oil sands region. Prof. Jochen Rudolph's group is collecting filters that will be analyzed off site for the presence of trace organic material in particulate matter such as nitro-phenols and high molecular weight hydrocarbons.

Atmospheric Chemistry and Physics Special Issue Editors

York faculty Jan Bottenheim, Donald Hastie and Rob McLaren are editors of a special issue of the science journal, Atmospheric Chemistry and Physics (ACP).  They edited a special issue, The Border Air Quality and Meteorology Study (BAQS-Met).  The BAQS-Met special issue consists of 19 journals published from Aug 2010 - Dec 2011.  The publication date for this issue is yet to be released.

Jan 29 2013