Regulars and Shorts

Guest Editorial: A New Take on Inversions

By Daniel Mendoza

“Proactive” is the word.

It’s winter in Utah and that means skiing and snow, but also our dreaded inversions. My research focuses on air quality and associated health effects, and too many times I’ve been asked to “fix” the inversion.

Bad news—I can’t. Due to our mountain ranges and high elevation, the Salt Lake Valley (as well as other areas in Utah and the Western U.S.) is particularly prone to inversions. An inversion is when a high-pressure system settles in and effectively locks air in place.

If we picture the Oquirrh, Wasatch and Traverse mountains as three sides of a bowl, and the high-pressure system as the lid, we can start to see how there’s little room for air to move around. Snow on the ground further reduces the energy available for air circulation and escape, which compounds the stagnation effect. The only way an inversion event ends is when the high-pressure system moves away.

While we can’t control whether an atmospheric inversion occurs or not, we can control what we emit into this stagnant air.

Historically we have been reactive, instead of proactive, to poor air quality. It’s only when the air quality index reads orange or red that people begin to take notice and are encouraged to carpool, take transit and avoid burning wood, among other measures.

However, the poor air quality typically lags the start of the meteorological inversion by two to three days. This means that while the air quality is still green—at the beginning of the inversion—we should start taking preventive measures since the pollution released at the outset will be trapped throughout the event.

We’re currently working on various approaches to inform citizens in advance of these events. By being proactive, we can help mitigate our poor air quality issues and the health problems that come with it.


Dr. Daniel Mendoza works in the Pulmonary Division and the Department of Atmospheric Sciences at the University of Utah. His research entails the quantification of urban emissions, subsequent pollutant exposure, and health outcomes. Dr. Mendoza will speak at the CATALYST / PechaKucha “Clean Air Affair” January 19, 8-midnight at Trolley Square. Info: see back cover and CATALYST’s Facebook page.


This article was originally published on January 1, 2018.