Abstract
Fairbanks held a local air quality meeting in October of 2017 where local scientists and researchers discussed air quality and there were presentations on a local wood stove regulation issue focusing on the health risks of woodstoves in relation with Fairbanks, Alaska’s extreme thermal inversions in the winter. This inspired this study to look at the relationship between air quality and thermal inversions and compare my results with professionally predicted results. The hypothesis is that there will be a higher concentration of PM2.5 molecules at lower elevations during cold weather that correlates with thermal inversion elevations. Thermal inversion traps particulate matter held in cold air beneath a layer of warm air. In preventing particulate matter from rising, the particulate matter will remain more concentrated beneath the thermal inversion. The adiabatic lapse rate is the rate at which temperature decreases with increasing altitude, and the cold air at the crests of the hills surrounding the valley of Fairbanks flows into and settles at the lowest points, pushing up beneath the warm air rising, creating an inversion. According to Gay-Lussac’s Law, as pressure increases, temperature increases.3 This supports the adiabatic lapse rate because as elevation increases, pressure decreases, and temperature therefore decreases. The null hypothesis is that there will be no discernible pattern in the relationship between thermal inversion and PM2.5, and that the data collected is not statistically significant. This will make it more challenging if not impossible to make accurate predictions in thermal inversion impact on PM2.5.
A route was created through West Chena Hill in Fairbanks, Alaska with GPS marked spots every 100 feet in elevation. The materials used were the Met One Instruments Aerocet 831 PM2.5 monitor, car thermometer, and the altimeter to record PM 2.5 data at each of the seven locations at the same time on days that were especially cold (below zero degrees Fahrenheit) or that had visual indicators of a thermal inversion. The results show that air quality does correlate to thermal inversion, and that air quality generally gets worse with increased elevation and drops significantly at the inversion. Outlying data points that did not follow this pattern resulted from measurements taken in an area with particularly high PM2.5 particle concentration due to a nearby woodstove. These points were included in the final data, but considered as outliers in the discussion and analysis.