The November 2018 California Biomass Burning as Measured by Purple Air Sensors

Recent advancement in technology and a rise in public awareness have led to an increase in the popularity of low-cost sensors. These sensors can be easily deployed and used by community members, creating large networks of air quality sensors whose data is accessible to everyone. One of these low-cost sensors is the PurpleAir PA-II unit that measures Particulate Matter (PM). Previous studies have compared PurpleAir units to other reference monitoring systems, and though the results have shown good correlations between the data of the different systems further investigation is required to evaluate the response of PA-II units under extreme conditions. In this study, we evaluated the performance of the PA-II units deployed in California during the November 2018 biomass burning events. California has a large number of PA-II units (>1000); our study examined spatial and temporal changes in PM_2.5 and PM₁₀ (Particulate Matter with aerodynamic diameter <2.5 and <10μm, respectively) as measured by several hundreds of PA-II during the biomass burning events.