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Edmonton’s Air Quality in the Time of Covid Part II: April Data

As discussed in a previous blog post, we saw in many other jurisdictions, such as the US Eastern Seaboard, China and Korea, a reduction in NO2 emissions brought on by physical distancing and movement restriction policies resulting from COVID-19. Edmonton is no different.

Anecdotally, during the height of the lock-down, I felt that the roads were less busy, and that it was easier (the odd time I actually left the house) to move through the city. I also saw distinct times when the Whitemud had no traffic, and the sound from the freeway was greatly reduced.  Well, we have some data to back up that anecdotal evidence, supporting the notion that Edmonton’s air quality may have improved during the COVID-19 lock-down, perhaps as a result of less traffic.

As noted at the conclusion of “Edmonton’s Air Quality in the Time of Covid”,  the ambient concentrations of NO2  in March 2020 were almost 30% lower than the average of NO2 for  March from 2015 to 2019. That is a significant decrease, but is it an anomaly?

Figure 1 (below) documents the data trends for the Edmonton Central Monitoring Station located downtown at the SE corner of 104 Street and 103 Avenue. These data were worked up by the Alberta Capital Airshed’s data scientist, Dr. Kevin McCullum.

NOx data trends for the Edmonton Central Air Quality Monitoring Station, March and April 2000 to 2020.

The lower image shows the data trends for the month of April from 2000 to 2020. While the April 2020 data is not as drastically reduced compared to the Aprils from 2019 or prior (I’m curious to know what happened in 2010), it is reduced.

In conclusion, the March 2020 data was about 30% lower than the average March data for previous years, and the April 2020 data was also reduced, but not as much and not as clearly linked to a lock-down resulting from the COVID-19 pandemic. It is still unclear whether that was as a result of COVID-19 or, as demonstrated in the header image for annual data from 2000 – 2020, a more general seasonal trend that occurs NOx and NO2.