Nan Miao

Chemical Transport Models (CTMs) are widely used as the operational method to provide chemical weather forecasts, and improvements of current CTMs forecast ability require a close integration of observations. Nan’s research interests are (1) implementing ensemble Kalman filter data assimilation technique to Weather Research and Forecast Model coupled with Chemistry (WRF/CHEM) to provide better short range chemical weather prediction, and (2) to optimize emission data through inverse modelling to reduce high uncertainties in emission inventories.

Nadya Moisseeva

Understanding the dynamics of sea-breezes in the mid-latitudes. By combining observational data with numerical modeling I am hoping to study the effects topography and coastline characteristics on wind hodograph rotation. As a case study, Nadya is focusing on the island of Sardinia in Italy, where sea-breezes are known do develop on all coasts exhibiting both clockwise and anti-clockwise hodograph rotation. By performing dynamical analysis of numerically simulated sea-breeze episodes on the island she is hoping to demonstrate that anti-clockwise hodograph rotation is caused predominantly by topography.

Zoe Davis

Understanding current levels of tropospheric air pollutants emitted by the Alberta oil sands industry, such as nitrogen dioxide (NO2) and sulfur dioxide (SO2), is essential to mitigate the impacts of increased industrial development on air quality. Our currently limited understanding of these tropospheric gas pollutant levels can be greatly improved with the use of Multi Axis Differential Optical Absorption Spectroscopy (MAX-DOAS). MAX-DOAS is a remote sensing technique that measures scattered sunlight at multiple viewing directions in order to quantify atmospheric tracegas absorbers.  In August 2013 a mini-MAX-DOAS instrument will be used to measure Slant Column Densities (SCDs) of NO2 and SO2 at ground sites north of Fort McMurray, Alberta in order to quantify tropospheric trace gas levels. Tropospheric Vertical Column Densities (VCDs) will be estimated from SCDs and validated using composite VCDs determined by airborne vertical measurements of NO2 and SO2. The research objectives include to determine: NO2 and SO2 VCDs; VCD enhancements in the Oil Sands over background levels; the direction and magnitude of the flux of transported trace gases; and whether the MAX-DOAS VCDs are comparable to equivalent satellite measurement VCDs.

Reynold Sukara

Overdense meteors and their radio echo durations are valuable tools for study of the upper atmosphere, especially of the secondary ozone layer between 80 – 100 km, where gradual ozone depletion had been observed in the past. Reynold’s research focuses on the development of the improved method of using meteor echo duration times along with experimentally derived diffusion coefficients to evaluate mesospheric ozone content with more accuracy.

Greg Wentworth

Ammonia (NH3) is emitted mostly from agricultural activity and is a key component of Earth’s atmosphere. Despite its impact on air quality and ecosystem health it is poorly constrained in atmospheric models, owing mostly to uncertainties in emissions. The goal of my research is to provide field measurements to better constrain NH₃ exchange between unfertilized soils and the atmosphere. I use an online instrument based on ion chromatography to measure atmospheric constituents while simultaneously measuring soil properties. These measurements can then be used to test our understanding of air-surface exchange processes and to improve existing air quality models.

Zheng Qi Wang

Wind profiler measurements of the OQ-Net. Currently, we have a network of 10 operational wind profilers located in Eastern Ontario and Western Quebec. These instruments measure hourly averages of wind speed and direction at every 500m above ground level . One of the uncertainties that have faced discloses the unknown accuracy of these measurements. As a result, we compared the wind profiler measurements with other sources such as radiosonde profiles and Rapid Refresh Forecast Model. After examining some of these comparison, such as hodographs, instantaneous vertical profiles and yearly data comparison, we find that wind profiler measurements strongly correlates to the radiosonde profiles and forecast model output. Although these findings proves the wind profilers have high accuracy, the comparisons also suggest that there are occasional outliers with the different data set. In the near future, we hope to continue to expand our understanding of the cause of these abnormal findings.

George Nikolakakos

LIDAR (LIght Detection And Ranging) instrument aboard the Phoenix Mars lander provided crucial new insight into the Martian atmosphere. Foremost among the LIDAR discoveries was the observation of ice crystals precipitating from clouds. Other key Phoenix mission findings included the confirmation that a water ice table exists below the surface, the observation of adsorbed water on regolith grains, and the detection of perchlorate, a highly deliquescent salt. The addition of Raman spectroscopy capabilities to the next generation of Mars LIDAR could greatly enhance the understanding of these Mars water cycle processes while maintaining the compactness of using a single emitted laser wavelength. In order to assess the feasibility of such an instrument and conduct process studies, a Raman LIDAR has been developed and operated at York University.

Amanda Jameer

Secondary organic aerosols (SOA) are known to affect the earth’s radiation budget through its ability to scatter and absorb radiation. Consequently, the mechanisms and factors that influence SOA composition and formation are poorly understood. Recent modeling studies coupled with smog chamber experiments suggest that organic peroxides (organic hydroperoxides and peroxyhemiacetals) might be a major component of SOA composition under low NOx conditions ([Reinnig et al., 2009], [Couvidat and Signeur, 2011]). Despite other group’s results, organic peroxide formation has not been detected by similar smog chamber studies performed at York University. In this study, an atmospheric pressure chemical ionization mass spectrometer (APCI-MS) is used to determine its utility in detecting organic peroxide formation from monoterpene oxidation experiments.

Jana Kharboutly

Test of low volume filter packs for sampling of atmospheric phenols

Menal Huroy

Tests of high volume filter samples for collection of atmospheric phenols

Yasamin Hassani

Method Development for Concentration Measurements of SVOCs in the Atmosphere with a Focus on Emission from Oil Sands Mining. Particulate organic matter (POM) consists of complex chemical mixtures found in the atmosphere that form a significant component of atmospheric particulate matter (PM). Phenols, polycyclic aromatic hydrocarbons (PAHs) and n-alkanes are some specific examples of semi-volatile organic compound (SVOC) found in airborne PM as well as in the gas phase. Despite the well-known harmful impact of these species on human health and climate, there is lack of knowledge regarding the atmospheric concentration levels of these pollutants emitted by the oil sands industry. As a result, a simple methodology that allows sampling and analysis of total ambient SVOCs at a wide range of concentrations is imperative. One such method using sorbent impregnated filters has been developed to quantify the total gas and particle phase concentration of SVOC in the atmosphere but has been tested on only one class of SVOCs, nitrophenols. The objective of my research project is to adapt and test this method for analysis of other SVOCs, with special emphasis on PAHs, n-alkanes and phenols. Using this method, concentration measurements of SVOCs emitted from oil sands mining will be conducted from the ambient samples collected at an Environment Canada ground site located north of Fort McMurray in Alberta.

Phillip Gregoire

Modeling gas-particle partitioning of inorganic gases and understanding the effect of ammonia interference on the molybdenum converter of commercial NOx and NOy instruments

Akshay Lobo

I took part in the Oil Sands Field Campaign in Fort McMurray, Alberta funded by Environment Canada. I tested and performed calibrations on the equipment to be taken into the field. I use the DOASIS software and wrote jscripts that would be used to automate the fitting procedure for data analysis. I was operating the Active DOAS instrument, measuring concentrations of trace gases NO2, SO2, and HONO. Using a Xenon laser, the Active DOAS transmitted a beam of light 1200 metres away to a 30 cornered-cube retro reflector. The retro reflector is precisely designed to return the transmitted laser directly back to the DOAS; this allows transmitting and collecting to be done by the same instrument and gives a total path length of 2400 metres.

Kacie Conrad

I’ve been involved in developing a Global PM_2.5 network called SPARTAN (Surface PARTiculate mAtter Network). The goal of SPARTAN is to create a ground based observation grid to evaluate and enhance satellite remote sensing estimates of fine particulate matter all over the world. This network will provide publically available data, which can be applied to health effects research and risk assessment.  I am involved in all three steps of the filter analysis as well as assembling, preparing, and testing the sampling stations before deployment.  First, we determine the amount of mass gained on the filter while sampling through gravimetric analysis. Comparing the mass of the post-sampled filter to the mass of the filter before it was sampled gives the amount of mass collected during sampling. I perform all of the weighing of the filters on a microbalance that is accurate to 0.0001mg in a clean room. Much care is taken to ensure accurate and precise measurements since gravimetric analysis tells us the most about the air quality. Next we analyze the filters for water-soluble ions using ion-chromatography; this can be related back to the mass of particulates found on the filter to identify their composition. Specifically, I’m involved with extraction of the ions from the filters and preparing the samples for the IC. Lastly we use ICP-MS (Inductively coupled plasma-mass spectrometry) to analyze for trace metals found in the samples. I prepare the samples for this process by performing acid digestion on each of the filters.

Soudeh Afsharian

Potential impacts of windfarms in Lake Erie: Some preliminary 1-D modelling using COHERENS.
More than 90% of the world’s offshore wind is installed in Europe and China, although there are plans in the USA (Atlantic – Cape Cod and Lake Erie – Cleveland) and Taiwan. There are also extensive plans for additional wind farms in Europe. If there were large scale offshore wind farm development in the Great Lakes, what impacts would they have? Small scale Ekman pumping, associated with spatial variation of the surface wind stress on the water surface caused by the turbine wakes will be a part of the influence of offshore wind farms but there will also be a direct effect of changes in the wind speeds and surface stress in the wind farm wake through reduced mixing of the upper mixed layer. We consider this in an idealized 1-D situation, appropriate to a large wind farm in uniform depth water, but we use real wind speed and other meteorological data to simulate variations over the ice-free season in Lake Erie.
COHERENS is the numerical software that we are using. The model is run twice. In the first case it simulates conditions in the absence of wind turbines while the second run includes a reduced (typically by 25%) wind speed associated with the effects of wind turbines. In the presence of wind turbines, surface water currents decrease in response to a decrease in the wind speed. The water temperature gradient increases as there is a higher surface water temperature in response to reduced mixing and a potentially shallower mixed layer and lower bottom temperature due to less heat diffusion. The thermocline develops faster and is stronger. The mixed layer depth exists for longer but is shallower than without wind turbines. There is a decrease in the latent and sensible heat fluxes while long wave radiation heat flux remains relatively unchanged.

Connie Ye

Alkyl nitrates (AN, molecular formula RONO2) play a crucial role in the troposphere as reservoirs of nitrogen oxides (NOx =NO +NO2) and by acting as chain terminators in the photochemical production of ozone. Mixing ratios of RONO2 in ambient air are commonly quantified by gas chromatography with electron capture or mass spectrometric detection (GC-ECD or GC-MS) coupled to purge-and-trap preconcentration, usually on Tenax sorbent, to improve the detection limits. An alternative method is to determine alkyl nitrates as a sum by thermal dissociation (TD) to a common fragment (NO2), which can then be quantified with a uniform response factor by optical absorption, for example by cavity ring-down spectroscopy (CRDS).
The goal of my research is to develop GC-ECD and TD-CRDS methods with purge-and-trap preconcentration for improved quantification of alkyl nitrates at ambient abundance levels. Chamber experiments will be conducted for examination of organic nitrate yields from reaction of volatile organic compounds (VOCs) with hydroxyl radicals (OH) in the presence of NOx as well as with the nitrate radical (NO3).

Sarah Kavassalis

My work so far has focused on quantifying the relative importance of the different chemical and physical mechanisms that regulate ozone pollution. As part of the NSERC CREATE Training Program for Integrating Atmospheric Chemistry and Physics from Earth to Space (IACPES), my first project was centred on a statistical analysis of historical EPA pollutant and meteorological monitoring data. By looking at 25 years worth of ozone data from more than 200 stations across the United States, I was able to identify unique meteorological controls on ozone pollution episodes. My second project is an ongoing collaboration with Dylan Jones in the Department of Physics to implement our work on the uptake of ozone by vegetation into the GEOS-Chem chemical transport model. I am currently writing new code for GEOS-Chem that will allow us to perform sensitivity experiments to see how climate and land use changes will affect ozone pollution in the future.

Sabour Baray

Quantifying methane emissions and identifying their sources, becomes critical for the understanding of surface emissions to consequential atmospheric processes. Comprehensive models require accounting for anthropogenic sources, including sources from fuel combustion and processing activities, as well as biological emissions from anaerobic methanogenesis, or “biogenic” methane. The oil sands in Alberta are a well-known and significant source of pollutant emissions in the Canadian environment; however peer-reviewed investigations identifying and tracing methane emissions in detail have been limited to one study in 2010 (Simpson et al., 2010). In this research, methane sources in the oil sands were investigated by analyzing ground-based and aircraft-based measurement datasets that were collected using cavity ring-down spectroscopy (CRDS) instruments. Differentiating between various sources of methane emissions, including unearthed biogenic methane from mine faces, methane resulting from fuel combustion (particularly off-road diesel vehicles), and methane resulting from processing activities are being accomplished by analyzing the mixing ratios of other gases expected to be present (Simpson et al., 2010), as well as by the construction of three dimensional geospatial images to identify high emission locations.

William Fujs

This research project will use a Tunable Diode Laser Spectroscopy instrument to quantify tropospheric methane (CH₄) concentrations. CH₄ has the second strongest radiative forcing (RF) impact on climate change of the major anthropogenic greenhouse gases, second to CO₂ (Ramaswamy et al. 2001). The RF Index is a method of assessing and categorizing the impact that certain gases will have on the radiative forcing, since pre-industrial times. Ice core samples indicate that CH4 levels have risen from as low as 400 ppb during glacial periods from before the industrial revolution to 1774±1.22ppb in 2005 (Spahni et al. 2005), and are currently in the 1.90 ppm range. This significant increase in atmospheric mixing ratios has only been observed to occur since the mid-1700’s (IPCC 2005 report). This increase is of concern because of the longwave radiative absorption abilities of CH₄ (Fleagle and Businger, 1963). The planet cools and achieves a balance with incoming radiation by emitting radiation in the IR wavelength range into space. Increased concentrations of CH₄ therefore have reduced the amount of energy that can escape into space, warming the surface, a phenomena known as the “Greenhouse effect”.

Natasha Garner

• The synthesis and analysis of chlorine nitrate using chemical ionization mass spectrometry (CIMS)
• The analysis of molecular halogen, cross halogen and halogen reservoir species during the Ozone-depleting Reactions in the Coastal Atmosphere (ORCA) field campaign, July 2015.

Aida Khanbabakhani

High SO2 concentrations are harmful to human health and adversely impact human health through their contribution to the formation of fine particulate matter in the atmosphere. Pollutant emissions from marine ships, including SO2 and NOX are considered to be the least regulated sources of pollutants, although that is changing. In the EU, inland SO2 emissions have been decreased through a series of regulations since the 1980’s while ship emissions still contribute significantly to global sulfur emissions. The chemical species present in marine vessel emissions are: NOx, SO2, CO2 and particulate matter (PM). SO2 emissions depend primarily on the amount of sulfur in a fuel. … The goal of my research will be to demonstrate the feasibility of using a combination of two long-path instruments: tunable diode laser spectroscopy (TDLS) for measuring CO2 and DOAS to measure NO2 and SO2.

Stefan J Miller

Highways are a common theme throughout much of Canada. My research examines trace gases, transport fluxes and turbulent fluxes on highways that result from different types of vehicles moving at moderate to high velocities. The hope is that the collected data, once analyzed, will provide a greater insight into vertical mixing near highways, which could help improve and validate meteorological model parameterization schemes. To gain insight into these trace gases, transport fluxes and turbulent fluxes, in situ measurements are obtained from a monitoring station (sonic anemometer as well as an aerosol and trace gas analyzer) secured to a vehicle, which is then driven on highways. Some data on turbulence has already been collected during the PanAm games, with a more comprehensive field campaign planned for this spring and summer to measure trace gases and transport fluxes in addition to turbulent fluxes. From this data analyses will be performed, allowing visualization of the spectrum of these turbulent fluxes and transport fluxes, hopefully aiding in our understanding of vertical mixing near highways.

Undergraduate Project Summer 2015

Wind and Turbulence Intensity Variations during PEIWEE Field Project

During the month of May, 2015 six 10m automatic meteorological observation stations (masts) were installed along the shoreline in North Cape, PEI. Measurements from these masts continued to be produced until October of the same year, allowing for a continuous time series of approximately five months in length. All masts measured the 10m wind speed, the 2m air temperature and the atmospheric relative humidity, while the shoreline masts were outfitted with several temperature and wind speed sensors to obtain a vertical profile.

The North Cape shoreline is characterized by a very steep (step-like) 12m cliff. Located inland from the shoreline are several wind turbines at varying distances and directions from the masts. The main goal of this field project was to gain insight into flow over this cliff (i.e. occurrences of airflow separation and how the roughness length transitions as the air comes ashore). Secondary to this goal was an attempt to visualize wind turbine wakes at the surface, through an examination of turbulence intensity variations and wind speed ratio reductions behind specific wind turbines.

Early results demonstrate that study has been successful in providing insight into flow over the cliff, with significant wind speed reductions noted below 10m when the flow is onshore. For flow perpendicular to the cliff, this flow separation was no longer present. The aspect of this field project examining wind turbine wakes was less successful, with only minor wind speed reductions being noted behind the closest wind turbines.

Youssef Taha

Alkyl nitrates (RONO2) are present in the atmosphere as a result of both direct emissions and secondary photochemical production. The main direct emission sources of alkyl nitrates are equatorial oceans1 with smaller contributions from biomass burning.2 Secondary production of alkyl nitrates occurs via the reaction of peroxy radicals with nitric oxide (NO). Although the reaction predominantly produces an alkoxy radical and nitrogen dioxide (NO2) the minor pathway leads to the production of alkyl nitrates.3 Alkyl nitrates are removed from the atmosphere via photolysis as well as hydroxyl radical oxidation. Nonetheless, alkyl nitrates have relatively long atmospheric lifetimes (on the order of days to weeks) acting as reservoir species for NOx. Accurate measurements of alkyl nitrates and the peroxy radicals that lead to their production are needed to gain a more complete understanding of nitrogen oxide budgets in the troposphere.

Travis Tokarek

Volatile organic compounds (VOCs) are chemical species that originate from both anthropogenic and biogenic sources. In high concentrations, they can be of concern because some VOCs are inherently toxic. Further, they have a tendency to form secondary organic aerosol (SOA), which can impact visibility, human health, and climate [1]. Gas chromatography (GC) is a particularly useful technique for separating and quantifying a large variety of atmospherically relevant VOCs in a relatively short amount of time. Many detectors are available that can (and have been) coupled to a GC column; for example, electron capture detection (ECD) is a useful method for detecting compounds that contain highly electronegative atoms such as peroxycarboxylic nitric anhydrides (PANs), alkyl nitrates, and halogen containing species. In many cases, preconcentration is required to quantify VOCs in ambient air by GC [2]. In many modern GC applications, mass spectrometry is used as a detector (e.g., [3-5]). Recently, Griffin Analytical has commercialized a compact GC that contains a Tenax preconcentration trap and a cylindrical ion trap mass spectrometer with electron impact ionization based on the design by the Cooks group at Purdue University; however, there have been no atmospheric applications of this new instrument published in the recent literature [6]. …

Jason Pak

To detect more explosives (e.g., tetryl). Among the challenges are matrix effects in ambient air, arising from organic nitrates. One task was the characterization of the “background” organic nitrates pose during explosive detection. I also constructed an NOy inlet following the work by Wild et al. (ES&T 48, 9609, 2014), which we will incorporate into our field TD-CRDS instrument.

Supriya Singh

Evaluation of physical and chemical sensors in the urban atmosphere

– measured vertical gradients, e.g. up the CN tower.
– worked with inexpensive next-generation chemical sensors that are being introduced to the market for air pollution monitoring, but whose quality is not well-understood.

Juan Zhao

Investigating the Fate of Ammonia in Evaporating Dew

This summer, I have been doing the follow-up study on the fate of ammonia in evaporating dew. The two objectives of this study are: 1. to verify the equation used to calculate the fraction of ammonia that volatilizes during evaporation in an urban environment; 2. to prove or disprove the hypothesis that NH4NO2 decomposition may occur, therefore acts as a sink for ammonia (Takenaka et al., 2009, Phys. Chem.).

Due to the heat island effect, natural dew has not been observed. Instead, synthetic dew (n=14) was made based on literature value from 18 sites worldwide. The experimental method and equipment for objective 1 could be found in Wentworth’s paper (2016, Atmos Chem Phys). As for objective 2, two experiments containing high concentration of NH4NO2 at low and high pH, respectively, were performed.

The experimental value for the fraction of ammonia that volatilizes was consistent with the predicted value. However, the former one was always lower than the latter one. In addition, a small fraction (5-10%) of ammonia was always found in the drying chamber (rather than volatilized) even though none was expected to remain in the drying chamber according to the equation. It is assumed that ammonia tends to adsorb to the glass surface. Consequently, some may volatilize but adsorb to the interior of the drying chamber before reaching the denuder, resulting in the unexpectedly high fraction of ammonia that remained in the drying chamber. Also, it made it difficult to fully extract all the ammonia from both the drying chamber and the denuder. As for the hypothesis of NH4NO2 decomposition, the recovery rate of ammonia for the two experiments involving NO2- was not found to be significantly different from the ones without NO2-. So this hypothesis was disproved.

For the next step, it would be reasonable to collect natural dew in the fall and to find solutions to reduce ammonia absorbance to the drying chamber during evaporation and to increase the extraction efficiency.

Nicole Chisholm

Contribution to a Surface Particulate Matter Network

This summer I was a student in Randall Martin’s Atmospheric Composition Analysis Group, and worked on SPARTAN or Surface PARTiculate mAtter Network. SPARTAN is a global monitoring network of PM2.5 and part of my job was to weigh and analyze filters from sites around the world. The filters are pre-­‐weighed and post weighed to figure out the total mass of PM2.5 that accumulated on the filters. They are then tested for black carbon using a Smokestain Reflectometer, as well as tested for water soluble ions using ion chromatography (IC) analysis and tested for trace metals using inductively coupled plasma mass spectrometry (ICP-­‐MS). Once all the data is processed it is made publicly available on the SPARTAN website.

One of the projects worked on this summer was correcting the ambient volume (Va) sampled by the sampling stations at each site to volume (VSTP) at standard temperature and pressure (STP). Other air quality monitoring groups correct to STP volume so that the amount of PM2.5 across all of the sites can be compared regardless of the temperature and pressure at time of sampling and this project looked into trying the same procedure.

The other project dealt with data from the nephelometers that are sent to each site along with the sampling station. The nephelometer measures the scatter by taking in outside air and uses red, green, and blue lasers to measure the scatter from that volume of air. The nephelometers are equipped with a Clean Air Reference System that blows clean air into the nephelometer to try and clear out the particles that get trapped inside. This project looked at how well the Clean Air Reference System works over time from each time it sampled during the day to the time series of the entire data set for a specific site.

Faisal Assad

The Photolysis Branching Ratio of Methyl Ethyl Ketone

The aim of the project that I undertook over the summer was to determine the photolytic branching of Methyl Ethyl Ketone (2-Butanone). The branching ratio of the compound can be determined by having the compound first irradiated with an ultraviolet (UV) source and then reacted with oxygen and nitric oxide in order to generate peroxyaceticnitric anhydride (PAN) and peroxypropanoic nitric anhydride (PPN). The generated PAN and PPN would then be sampled by the Osthoff Group PAN-GC in order to determine their relative concentrations.

The project was unfortunately faced with several obstacles. The first of which was that the PAN- GC was not operating correctly due to a possible contamination. A long period of time was spent attempting to troubleshoot and determine the root cause of the high baseline. After having changed and replaced all tubing, columns, cylinders etc., a second GC was utilized. Issues arose with the second GC in which an unknown peak eluted at the same time as PPN. In order to be time-efficient, the analysis was changed from using a GC to using the Osthoff Groups Iodide ion Chemical Ionization Mass Spectrometry (iCIMS) instrument. As data was collected for a range of temperatures and two different wavelengths, the iCIMS showed less and less sensitivity to the compounds over time. The final result was that although data had been collected, the relative response of the two compounds for CIMS had significantly changed from previous calibrations which would indicate troubleshooting is required for the instrument.

The summer research project and working with the Osthoff group has allowed me to learn and expand on my knowledge, both in chemistry-related aspects but also as a person. I was able to use and work with a few instruments and techniques, two of which I had no prior experience with at all (iCIMS and Thermal Dissociation Cavity Ring Down Spectroscopy (TDCRDS)). Furthermore, I gained valuable knowledge in learning how to approach troubleshooting instruments, particularly GCs. I also learned the importance of working together with group members to discuss and brainstorm possible solutions to issues (such as pressure-influenced problems). The idea of perseverance was also heavily focused on this summer.

Due to instrumental failure and lack of time to compensate for it, future data collection and analysis must be performed in order to complete the project.