Events Calendar

Astani CEE Department Seminar

Speaker: Kristina M. Wagstrom, Postdoctoral Associate, , Department of Civil Engineering, University of Minnesota

Talk Title: Relating Emissions and Particulate Matter Concentrations in the Complex Ambient Atmosphere

Abstract:

In order for policy makers to effectively regulate emissions, there needs to be a strong understanding of the relationships between emissions and resulting air pollutant concentrations even in the complex mixtures that make up many airsheds. In order to more fully relate sources and ambient pollutant concentrations, I have implemented and evaluated an algorithm capable of tracking the contributions of different sources types and locations to particulate matter concentrations in a three-dimensional atmospheric chemical transport model. I will discuss the details of this algorithm and its utilization to study the origins of particulate matter in the Eastern United States. I used three different approaches in order to create a more complete picture of pollutant origins:

1) I quantified the impacts of emissions from large source regions on the particulate matter concentrations in surrounding areas as pollutants are transported out of those areas into surrounding regions.

2) I studied the contributions from transported pollutants on local air quality problems by identifying the distance pollutants are transported before arriving in regions of interest.

3) I estimated the average age of particulate matter in the atmosphere by tracking when pollutants were emitted. Knowing the age of particulate matter gives us insight into the relative importance of many processes in the atmosphere.

This work has increased our understanding of the impacts of emissions and pollutant transport on particulate matter concentrations. Our studies have suggested that a large fraction of the ground level concentrations of primary (directly emitted) particulate matter in urban areas tend to be from local emissions while the concentrations of secondary species (formed in the atmosphere) such as sulfate or secondary organic particulate matter are more likely to result from regional sources. I found that the distance, direction and amount of particulate matter transport occurring from large source regions was highly variable in time and dependant on particulate matter species. The ages found for particulate matter species were highly variable in time, space (both horizontally and vertically) and by species. Primary species were found to have ages on the order of one to two days while secondary species had ages ranging from one to several days. These results provide information about the relative importance of different reactions and pollutant transport processes in the atmosphere which provides insight for future model development and guidance for policymakers.

Location: Kaprielian Hall (KAP) - 209 Conference Room

Audiences: Everyone Is Invited

Contact: Evangeline Reyes