Grad student studying how Chinooks affect air pollution

Calgary’s Chinook winds are more than a welcome break from the deep freeze of winter for Calgarians, they also provide weather patterns that affect the city’s air quality. These same Chinook winds carried Rachel Mintz to study air pollution formations that are specific to Calgary’s geography.

Mintz, a Master’s of Science candidate in the Department of Chemical and Petroleum Engineering, is developing an integrative computer model of air pollution for the city of Calgary that merges two established methods of predicting pollution patterns. Mintz hopes that this will provide more accurate information to the people making decisions for industry and public health policies.

Traditionally, there are two types of pollution modeling systems, physio-chemical and statistical. The physio-chemical methodology involves meteorology, chemistry and engineering. This method is mathematical and involves looking at the kinetics of variables including temperature, cloud cover and wind speed. However, involving many variables is a large challenge.

"There are still areas and variables that (researchers) don’t know how to correlate," said Mintz.

This is where the statistical methods come into play. "Statistical models are more like a black box approach", Mintz explained. Mintz’s modeling project objective is to incorporate a type of black box approach called "fuzzy logic". The basis of fuzzy logic is past experience. Mintz hopes this form of logic will fill in the gaps left by the physio-chemical approach.

The goal of Mintz’s research is to get a better understanding of how pollution and the atmosphere are interacting, focusing on the specific geography of Calgary.

"The Chinooks cause temperature inversions that prevent pollution from dispersing, leaving us with a haze or smog hanging over the city," said Mintz.

The Chinooks, as well as many other natural factors, cause these episodes of increased pollution in Calgary. Mintz explains that, "all aspects of weather contribute to the levels of pollution in a city including temperature, wind speed and cloud cover." The proposed pollution model will incorporate all of these variables.

Mintz also hopes to improve upon present pollution models by addressing issues including computing time and the specificity of variables for a particular geography.

"Present models are very computer intensive," said Mintz.

This is in part due to the number of variables that the models are trying to address. Urban centers often use pollution models that require the input of data is not collected, or they use pollution models that do not pertain to their particular geographical area. This leaves holes in the computing, leading to either no output or an inaccurate interpretation of the city’s pollution.

Arguments centering on the Kyoto Accord have recently questioned the accuracy of pollution modeling. "Present models are able to predict general pollution trends. However, (pollution) models can definitely be improved upon" Mintz said.

Mintz’s pollution model aims to provide a better understanding of what is going on with regards to pollution in the city of Calgary. With this knowledge, those involved with industry policy and health awareness will be better equipped to make logical, founded decisions.

Story by Rebecca Malott, a Master’s student in the Department of Microbiology and Infectious Diseases and a writer with the U of C SPARK (Students Promoting Awareness of Research Knowledge) program.