R plot: Comparison of Fairbanks, Alaska and Beijing, China air quality

Here’s an interesting R plot comparing a specific air pollution metric between Fairbanks, Alaska and Beijing, China. Right off the bat, Beijing obviously has far worse air quality, and more significantly, it is a chronic, daily problem. But it is used for comparison because we already know this is the case.

In Fairbanks, while air quality is known to decrease in very cold weather and the seasonal cycle of winter spikes in the particulate are clear in the plot, this is nothing compared to Beijing’s daily levels year round. On the other hand, lots of summertime smoke from boreal forest fire in interior Alaska can make Fairbanks air quality just as bad as Beijing’s if not worse. This can be seen in 2004, which was a year of record fires in Alaska. 2015 has also been a big fire season, apparent in the plot as well.

In order to plot the most up to date data, multiple sources were merged. A no-intercept regression of the more vetted baseline Fairbanks data on the more recently obtained data dump was fitted. While the latter is not yet a fully cleaned and vetted source, the differences are systematic. A bias in magnitude during the overlapped dates in 2015 suggests a 20 percent boost to particulate levels over what the new preliminary data show.

While the new data dump seems “good enough”, an adjustment can be made with respect to the baseline information. This provides an up to date look at air quality during the 2015 fire season that is more robust to measurement errors and other potential sources of discrepancy with the longer historical series. This is valuable pending availability of new fully vetted data, which often takes longer to become available than is ideal.