Weather balloon data for Salt Lake City Airport (and other out-of-state areas) with data every 12 hours starting in 1973 through the present day. This data could help measure the time and duration of inversions and other weather patterns that affect air quality.
SLC station identifier = 72572
Contains the height and all of the following info for each height:
Wind direction (degrees)
Wind speed (knots)
It also contains information about the weather station.