EESS talk - Student presentation on "Analysis of the vertical distribution of pollution layers in the urban sub-Arctic in winter"


Event details

Date 14.05.2024
Hour 12:1512:35
Speaker Roman Pohorsky, EERL
Location Online
Category Conferences - Seminars
Event Language English
The Alaskan Layered Pollution and Chemical Analysis (ALPACA) field campaign was conducted during the winter months of January and February 2022 to examine urban pollution sources and transformations in Fairbanks, Alaska. Several data collection sites were set up throughout the city to investigate the less-explored dynamic, physical, and chemical mechanisms governing air pollution events during the cold and dark winter.
To explore the vertical dispersion of pollutants, an observation site was set up in the suburban area just outside downtown Fairbanks. It featured ground-based measurements, and a tethered balloon carrying a custom-built air-sampling platform for vertical profiling of the atmosphere. Sampling included measurements of aerosol microphysical characteristics and trace gases (CO, CO2, O3, NOx).  The vertical in situ measurements were used to assess the layered structure and vertical mixing of pollutants under stable atmospheric conditions from sources located at the surface but also at higher elevations, such as emissions from high power plant stacks. Results of the analysis show how synoptic and local meteorological conditions can create competing effects on the stability of the atmosphere and how pollution at higher elevations persist and ages over Fairbanks. The findings from this study contribute to a better comprehension of pollution dispersion during the extremely stable conditions often observed in the Arctic winter. These insights can inform the development of strategies to mitigate pollution by pinpointing the conditions and sources responsible of high pollution events.

With a background in environmental sciences from the University of Lausanne, I completed my Masters in Climate Sciences with a focus on large scale atmospheric dynamics at the University of Bern. I started my PhD in 2020 at the Extreme Environments Research Laboratory in Sion under the supervision of Julia Schmale. In my PhD I focus on the vertical distribution of aerosol particles and trace gases in the lower atmosphere. The vertical distribution of these compounds is very important when accounting for their effects on health and climate. Over the past years, I had the chance to participate in several field campaigns in Arctic and sub-Arctic regions to deploy a tethered-balloon system that I developed.   

Practical information

  • General public
  • Free
  • This event is internal


  • EESS - IIE


  • Prof.Julia Schmale, EERL


aerosol boundary layer in situ measurements Arctic