Later tonight I arrive in Salt Lake City where misery awaits. I've been watching the air quality there the past few days and it looks nasty as the PM2.5 concentrations have been flirting with the National Ambient Air Quality Standard for several days. One thing that is interesting and that I don't understand are the huge fluctuations from day to night in PM2.5 concentration. These are as large as I've seen. Perhaps someone out there who knows more about air chemistry can comment.
|PM2.5 concentrations in the Salt Lake Valley. Source: Utah Division of Air Quality|