What is an inversion?

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If you’ve lived through a winter or two in Utah, you’ve probably heard the term “inversion” used to describe our weather. In fact, even if you’ve never heard that word before, you’ve almost definitely seen the effects of inversion.

Before you can understand Utah’s air quality challenges, however, you need to understand a little bit about our geography. You see, many of Utah’s cities and towns reside in valleys, and most of these valleys are surrounded by mountains. Take the Salt Lake Valley as an example. It has the Oquirrh mountain range to the west and the Wasatch mountain range to the east. These mountains meet at the south end of the valley to create a bowl.

This geographic bowl is key to understanding why inversion happens. Essentially, natural weather conditions create a layer of warmer air that collects at the top of the bowl. This layer of air then acts as a lid, trapping the cooler air below. And just as the cold air can’t escape, neither can the pollution.

We can’t control the inversion. It happens several times every year, and there’s nothing we can do to prevent it. In fact, the pollution it traps can’t leave the valley until after a storm or heavy winds blow through (also out of our control). This becomes increasingly hazardous, as the amount of pollution in our air doubles every day during periods of inversion. Considering these periods can last weeks at a time, it isn’t a stretch to say that Utah’s air quality can go from delightful to dangerous in no time at all.

While we can’t control when inversion will come or go, we can control the emissions we release. Even simple changes to our daily routine can have a big impact on Utah’s air quality. Things like reducing cold starts, being idle free in our cars or carpooling and riding transit, help every Utahn breathe easier. In other words, if we work together, we can reduce the negative effects of inversion and improve our air quality.

For more information on inversion, check out this page for more ways to show UCAIR about Utah’s air and make changes to reduce your emissions.