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News & Events

Mar
18
Tue
Combination of active and passive Lunar DOAS to determine the vertical chemical profile of NOy species in the atmosphere @ 317 Petrie Science and Engineering Building
Mar 18 @ 4:00 pm – 5:00 pm

Speaker: Kevin Nikelski, graduate student with Prof. McLaren

Description:  The experimental advantages of the use of passive moonlight
collected via telescope for analysis of nocturnal atmospheric species
by differential optical absorption spectroscopy (lunar DOAS) will be
discussed.  Use of this technique has primarily been focused on
observation of the nitrate radical.  A potential method of measurement
of other nocturnal nitrogen species (HONO, NO2) through the
combination of lunar DOAS measurements of the residual layer and free
troposphere, and active measurements on the surface will be presented.
 Potential future work will also be suggested.

Oct
28
Tue
What to do in Europe for 3 months: Tales from an IACPES Research Exchange @ 317 Petrie
Oct 28 @ 12:00 pm – 1:00 pm

Speaker: Dr. Marina Saccon

Description: A 3 month exchange was completed at the Forschungszentrum Jülich to conduct kinetic experiments of reactions of atmospheric volatile organic compounds (VOC). During the last decade, the number of publications using carbon isotope ratio measurements in studies of atmospheric VOC has been increasing substantially. Knowing the kinetic isotope effects (KIE) for the atmospheric reactions of VOC is essential for the use of isotope ratio measurement in understanding and differentiation of chemical and physical processes in the atmosphere, such as chemical reactions, dilution and transport. Ethane, the second-most abundant hydrocarbon in the background atmosphere, was chosen as the target compound since it is the only compound in which a global transport model has been made based on isotope ratios. Compared to most other VOC, the exceptionally low rate constant of ethane with the OH radical along with its high volatility have made the KIE of ethane difficult to quantify. This presentation will present the method development in the determination of the KIE of light VOC as well as the advantages of visiting an institute situated in an area within driving distance to Europe’s most interesting places.

Nov
11
Tue
A Phd. Candidate goes abroad: Four month of learning about DOAS … Heidelberg, Germany @ York University, Rm. 317 Petrie
Nov 11 @ 12:00 pm – 1:00 pm

Informal Lunchtime Atmospheric Chemistry Discussion Series

Presented by: Zoey Davis, Phd. Graduate Student

A Phd. candidate goes abroad: Four months of learning about differential optical absorption spectroscopy and optical estimation methods in Heidelberg, Germany

Description:

A four month exchange was undertaken at the Institut für Umweltphysik at Heidelberg University, Germany in order to learn more about and implement Differential Optical Absorption Spectroscopy (DOAS) analysis techniques on Multi-Axis DOAS (MAX-DOAS) measurements from the Alberta Oil Sands (AOS) and retrieve profiles of boundary layer aerosol extinction and trace gases from these measurements using an optimal estimation method. The scarcity of independent measurements of industrial air pollution emissions in the AOS limits our understanding of the impacts of the area’s industrial activity and the ability to make quality environmental management decisions. The dataset was collected during the 2013 Environment Canada AOS air quality campaign and represents the first retrievals of vertical profiles of SO2 and NO2 from MAX-DOAS measurements in the AOS. This talk will present improvements to our methodology for trace gas retrievals using DOAS analysis. The basic theory of the optimal estimation retrieval method and a case study from preliminary retrieval results will be presented. Potential methods for estimation of trace gas emissions from particular AOS facilities using the retrieved trace gas profiles will be discussed.

Nov
25
Tue
Quantifying sources of methane using cavity ring-down spectroscopy @ Rm. 317 Petrie
Nov 25 @ 12:00 pm – 1:00 pm

Informal Lunchtime Atmospheric Chemistry Discussion Series

Presented by: Sabour Baray, Graduate Student

Description:  Of the compounds most influential in radiative forcing, methane is 3rd overall next to water and carbon dioxide. While background levels of methane have been relatively stable since the 1980’s, a recent and poorly-understood spike in the mixing ratio has been observed as of 2007. In these studies sources of methane were investigated in both industrial and urban environments. In the summer of 2013 during the Oil Sands field study led by Environment Canada, aircraft and ground-site measurements of multiple species, including CO2, CH4, CO and H2O were made by a Picarro cavity ring-down spectrometer (CRDS) instrument. Methane peaks of up to 4.3 parts per trillion were observed, and analysis has been ongoing in order to paint a 3 dimensional picture of emissions and to differentiate between various sources present. In the fall of 2014, an urban field study in the Greater Toronto Area was completed with the same CRDS instrument in order to investigate methane emissions from various classes of vehicles. A range of emissions factors were observed up to 3 times the recommended values in the Canadian inventory.

Jan
13
Tue
Lake Erie: Some preliminary modelling using COHERENS @ Rm. 317 Petrie
Jan 13 @ 12:00 pm – 1:00 pm

Informal Lunchtime Atmospheric Chemistry Discussion Series

Presented by:  Soudeh Afsharian, IACPES Graduate Student

Description:  The potential of offshore wind is enormous. It could meet Europe's energy demand seven times over, and the United States energy demand four times over.
Offshore wind is a relatively new technology, More than 90% of the world's offshore wind power is currently installed off northern Europe. Most of the rest is in two "demonstration" projects off China's east coast although there are plans in the USA (Atlantic - Cape Cod and Lake Erie - Cleveland).
The key benefits of offshore wind are:
● The wind resource offshore is generally much greater, thus generating more energy from fewer turbines;
● Most of the world's largest cities are located near a coastline. Offshore wind is suitable for large scale development near the major demand centers, avoiding the need for long transmission lines;
● Building wind farms offshore makes sense in very densely populated coastal regions with high property values, because high property values make on shore development expensive and sometimes leads to public opposition (especially in Ontario!).
● At present there is a moratorium on offshore wind farm developments in Ontario but OMECC have recently announces two RFPs related to offshore wind farms so things may change. If there were large scale wind farm development in Lake Erie (because it is relatively shallow) what impacts would this have on lake circulation and mixing?

On land the Erie Shores Wind Farm was one of the first in Ontario. It allows
200,000 tonnes of carbon dioxide emissions, the major contributor to global warming, to be displaced from the environment annually.
COHERENS (A Coupled Hydrodynamical-Ecological Model for Regional and Shelf Seas) is numerical software that we plan to use in order to simulate the effects of the wind farms on the circulation and mixing of the water. We are working on Lake Erie, since this has the highest potential for offshore wind turbine installation due to its location and as is the shallowest among the Great Lakes. At this stage we can
provide good results of simulating the heat fluxes, temperature, water current and thermocline by running the model in a 1-D condition driven by hourly wind and air temperature data. Our next step will be to extend this simulation to the 3D situation.

Jan
20
Tue
Estimating surface fluxes of CO2 in the Hudson Bay Lowlands using a Lagrangian Particle Dispersion Model (STILT) @ York University, Rm. 317 Petrie
Jan 20 @ 12:00 pm – 1:00 pm

Informal Lunchtime Atmospheric Chemistry Discussion Series

Presented by:  Olalekan Balogun, Graduate Student, Geography
Supervisors: Dr. Richard Bello, Dr. Kaz Higuchi
Description:
The Hudson Bay Lowlands (HBL) region of Canada is the second largest semi-continuous wetland region in the world covering an area of 320, 000 km2. Consequently, there has been much interest in quantifying wetland emissions and fluxes from the HBL. Such studies are vital to a better understanding of greenhouse gas emission estimates and fluxes from northern wetlands; a prerequisite for accurate global climate change modelling and predictions by GCMs.
In this study, we employ a Lagrangian particle dispersion model (STILT) coupled to the North American Regional Reanalysis (NARR) dataset to model CO2 and CH4 atmospheric concentrations in the Hudson Bay Lowlands. The model results are compared with actual measurements from the Churchill Northern Studies Centre (CNSC) microwave tower. Furthermore, surface fluxes of these gases are estimated and mapped to show the upstream influences on the measured mixing ratios at the CNSC microwave tower in Churchill Manitoba.

Feb
3
Tue
Three Months of Research Exchange at Forschungszentrum Juelich: A Sneak Peek Inside @ York University, Rm. 317 Petrie
Feb 3 @ 12:00 pm – 1:00 pm

Informal Lunchtime Atmospheric Chemistry Discussion Series

Presented by:  Mehrnaz Sarrafzadeh, Graduate Student
Discription:   A three month research exchange was conducted at Forschungszentrum Jülich in Jülich, Germany to extend our knowledge of secondary organic aerosols (SOA) formation from beta-pinene photo-oxidation. SOA constitute a substantial fraction of ambient organic aerosols and are known to adversely affect visibility, climate and health. Despite extensive studies, the chemical composition and mechanism of SOA formation is not well understood.
Experiments were carried out under atmospherically relevant conditions in the Jülich Plant Atmosphere Chamber (JPAC) to investigate the SOA mass yield as well as climate parameters that impact mass yield​,​ such as NOx. Furthermore, ​the formation and detection of highly oxidized multifunctional products which contribute significantly to atmospheric SOA​ is briefly discussed​.

Feb
17
Tue
Airborne LIDAR Measurements of aerosol and Ozone @ York University, Rm. 317 Petrie
Feb 17 @ 12:00 pm – 1:00 pm

Informal Lunchtime Atmospheric Chemistry Discussion Series

Presented by:  Monika Aggarwal, Graduate Student
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).

Mar
3
Tue
Method Development for Concentration Measurements of SVOCs in the Atmosphere @ York University, Rm. 317 Petrie
Mar 3 @ 12:00 pm – 1:00 pm

Informal Lunchtime Atmospheric Chemistry Discussion Series

Presented by: Yasamin Hassani, Graduate Student
Description:  to be posted.

Apr
7
Tue
HONO-Measurements During the OS Field Campaign at AMS13 @ York University, Rm. 317 Petrie
Apr 7 @ 12:00 pm – 1:00 pm

Informal Lunchtime Atmospheric Chemistry Discussion Series

Presented by:  Kevin Nikelski, Graduate Student
Description: Nitrous acid (HONO) is of particular relevance to atmospheric chemistry in regards to its significant contribution to photochemical production of the OH radical, which serves as the main daytime oxidant in the troposphere. Many studies have reported observing significant HONO mixing ratios during daylight hours, which could be due to an as yet unexplained continuous daytime source and/or indicating a method of HONO uptake and storage during the night with subsequent release the next day. In this talk, I will discuss HONO measurements from Aug 17th- Sept 11th during the OS field campaign region near Fort McMurray Alberta at the AMS13 ground site. The measurements in question were obtained through use of a DOAS 2000 telescope and 30 corner cube retro-reflector, along a 2.304 km path length. The methodology for spectral fitting of HONO using (DOASIS) will be discussed in some detail, as will both night-time and daytime preliminary mixing ratios. Preliminary results indicate that HONO mixing ratios at night during the OS field campaign were typically less than 300ppt, much lower than those observed in the urban area of Toronto (York University), which has a median nighttime maxing ratio of 1.0ppb. The lower levels of HONO at AMS13 is consistent with the lower night-time mixing ratios of the main precursor, NO2, which had a night-time median of 1.1 ppb during dark periods at AMS13, compared to a nighttime median of 16ppb in Toronto.

Updated on December 6th, 2012.