EES Departmental Seminar - Dr. Aldona Wiacek (Saint Mary's University)

Title:  From surface ozone pollution to ocean-air gas fluxes in Halifax, Nova Scotia

Dr. Aldona Wiacek
Associate Professor
Department of Environmental Science Department of Astronomy & Physics
Saint Mary’s University

Abstract: This talk will highlight recent work in my group related to air quality analysis and greenhouse gas emissions measurements.  First, I will discuss a data-driven study of controls on surface ozone pollution in Nova Scotia based on an analysis of long-term (2000-2021) NAPS in situ sensor data and provincial emission inventories.  A novel spatial correlation algorithm was developed to diagnose transported pollution events that cause high ozone across the province.  We find that transported pollution accounts for 45-63% of the elevated ozone days in Halifax, with upstream source regions identified using HYSPLIT.  Second, I will introduce a field study of nitrous oxide (N2O) emissions from the coastal waters of Halifax based on open-path FTIR spectroscopic measurements in the flux-gradient approach.  We derived a time series of ocean-air N2O fluxes in Halifax Harbour from December 2020 to April 2021, with a total flux of -10.8 kg N2O ha-1 (into ocean).  While the ocean is globally a source of N2O to the atmosphere, there is significant spatial and temporal variability, particularly in coastal locations, which I will discuss.

Bio:  Aldona Wiacek is cross-appointed in the Departments of Environmental Science as well as Astronomy & Physics at Saint Mary’s University (SMU) in Halifax.  Prior to joining SMU in 2013, Aldona helped establish the Toronto Atmospheric Observatory as part of her Ph.D. studies at the University of Toronto; she then researched aerosol-cloud interactions as a Marie Curie Postdoctoral Fellow at the Swiss Federal Institute (ETH) in Zürich; finally, she held the position of Research Associate (remote sensing of aerosols) at Dalhousie University in Halifax.  She is interested in remote sensing of atmospheric trace gases involved in air pollution and climate and also in the climate effects of aerosol through cloud interactions.  



Format: in-person
Milligan Room (8th floor LSC Biology Wing)