Informal Lunchtime Atmospheric Chemistry Discussion Series
Presented by:  Mehrnaz Sarrafzadeh, Graduate Student
Tuesday, Feb. 3rd. Noon - 1PM - 317 Petrie

Description:  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​. ​

Informal Lunchtime Atmospheric Chemistry Discussion Series

Presented by:
Olalekan Balogun, Graduate Student, Geography
Tuesday, January 20th, 2015
317 Petrie Science and Engineering

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.

Bring your own coffee/tea mug. Cookies will be served.

Informal Lunchtime Atmospheric Chemistry Discussion Series

Presented by
Soudeh Afsharian (Phd. Candidate)
Tuesday, January 13, 2015 @ 12:00 pm - 1:00 pm
317 Petrie Science and Engineering Bldg.
York University

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.

Informal Lunchtime Atmospheric Chemistry Discussion Series

Presented by
Sabour Baray (M.Sc. Candidate)
Centre for Atmospheric Chemistry
Tuesday, November 25, 2014 @ 12:00 pm - 1:00 pm
317 Petrie Science and Engineering Bldg.
York University

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.