I'm pleased to report that some of my colleagues have taken the bull by the horns and have placed weather and air quality instruments on a Utah Transportation Authority (UTA) TRAX train system. This will provide an unprecedented look at PM2.5 concentrations in the Salt Lake Valley and along transects running up the west and east benches.
Here's a look at the data coming in this morning. PM2.5 concentrations this morning are lowest on the west bench (light green circles) and highest from roughly 4500 South to 2100 South (yellow circles).
For a look at the Trax PM2.5 data, see http://meso1.chpc.utah.edu/mesotrax/. This is an experimental product, so there will be periods when data is not available.