Friday afternoon I sat in on poster presentations by three graduate students at the University of North Texas organized by the engineering school — good practice for building their science bona fides and good practice for me in listening to scientists.
I was a little lost for the presentation on improving truck radiators with microchannels and frequently lost on the presentation about shape memory alloys, although we got to watch this very cool YouTube video of a bent spring coiling back into its original shape when heated:
I was able, however, to follow the third presentation on a study of DFW air quality, in part, because I’ve been listening to a number of these technical discussions for the past several years.
Graduate student Mahdi Ahmadi, working with his advisor, Dr. Kuruvilla John, downloaded the ozone air monitoring data from the Texas Commission on Environmental Quality back to 1997, a total of more than 6.5 million data points, he said, and has been studying it for the past four months. (He is in the second draft of a paper that will be submitted for publication, so his talk was the beginning of a discussion that surely will include more feedback from his professors — I saw some of that Friday — and from the editors/reviewers of the journal that accepts the paper for publication.)
Ahmadi wanted to explore a basic question underlying a graphic frequently distributed by the TCEQ that shows gas wells going up in DFW as ozone goes down, which suggests in a not-very-scientific-at-all way, that the increasing number of gas wells is having no effect on the ozone.
Ahmadi adjusted for meteorological conditions to determine how much ozone DFW people are making and where. Such adjustments have been explored by others to understand better the parts of ozone-making we can control, because we can’t control the weather. He used an advanced statistical method on the data, called the Kolmogorov-Zurbenko filter, to separate the effects of atmospheric parameters from human activities.
According to the results, the air monitoring sites surrounded by oil and gas production activities, generally on the west side of DFW, show worse long-term trends in ozone reduction than those located farther from wells on the east side of DFW.
His spatial analysis of the data showed that ozone distribution has been disproportionally changed and appears linked to production activities, perhaps an explanation why residents on the western side of DFW are seeing more locally produced ozone, particularly since 2008.
In other words, Denton residents have long suffered the drift of polluted air from the south, but as our neighbors to the south drive cleaner cars and get clean ups from the cement plants and other big polluters, regulators should probably look again at the 5,000 gas wells and their associated equipment in Denton County to help clean up local air quality.
Most interesting to me is that Ahmadi also looked at ozone levels produced in the “off season” and noticed that those numbers, too, are climbing up. DFW ozone season is generally considered April-October, but if the EPA again lowers the standard to 65 ppb, that could bring more months, February-November, into our “ozone season,” John said.
Ahmadi and John said this study, for the first time, is demonstrating the long-term negative effects of oil and gas production activities activities on local and regional ozone pollution. We’ll be watching for the final peer review and publication of their paper and expect that others charged with cleaning up North Texas air will do the same.