If you're in the Salt Lake Valley, you might have seen a plane circling low above the city over the past month. Tucked between multi-million-dollar private jets at the Salt Lake City International Airport is a small, twin-engine prop plane packed with sensitive instruments to measure the makeup of the atmosphere. The plane spirals up and down over parts of the valley and even flies as low as 200 feet above the Great Salt Lake to get accurate data. Perennial threats from inversion, toxic Great Salt Lake dust and wildfire smoke are constant reminders of the state's delicate environment. With final results of the study expected sometime next year, researchers like Hall hope the data will help inform future air quality decisions.