I See Your Fireworks

It was an unusual Fourth of July holiday this year due to COVID-19 restrictions.  Public fireworks displays were limited, with none in Salt Lake County, but a few displays in Tooele and Utah Counties (see https://www.deseret.com/entertainment/2020/7/3/21311412/4th-of-july-events-fireworks-parade-celebration-utah-salt-lake-stadium-of-fire). 

However, individual displays were plentiful, and one can "see" these fireworks in PM2.5 measurements collected by the Utah Division of Air Quality.  PM2.5 spikes were occurred on either the night of the 3rd or 4th or both, indicating degraded air quality. 

Cache County gets the reliable patriotism award for producing spikes on both the night of July 3rd (times below local) and July 4. 

Cache County PM2.5 concentrations.  Source: Utah Division of Air Quality.

Utah County gets the extreme patriotism award for producing the highest PM2.5 concentrations measured by one of the DAQ's real-time sensors, with values reaching over 160 ug/m3 on the night of the 4th.  Technically, they could have pipped Cache County for the persistent patriotism award too since they also produced a spike on the night of the 3rd, but in this contest, everyone gets only one award. 

Utah County PM2.5 concentrations.  Source: Utah Division of Air Quality.

Davis County gets the extreme patriotism honorable mention award for also pushing PM2.5 to relatively high levels (> 100 ug/m3), but falling shy of Utah County's effort.  Nice try.  Maybe next year. 

Utah County PM2.5 concentrations.  Source: Utah Division of Air Quality.

Finally, Salt Lake County gets the participation award.  Nothing on the night of the 3rd with a pulse on the 4th that barely gets to 40 ug/m3.  On a population-adjusted basis, that's pretty pathetic, although many of us were happy to breath easy. 

Salt Lake County PM2.5 concentrations.  Source: Utah Division of Air Quality.

These are single point measurements though and there was probably a great deal of spatial variability that one might explore using the PurpleAir network, although I have work to do to get my classes ready for fall....