Estimating Pm 2.5 In British Columbia Before And After Wildfires Using 3 Km Modis Aod Products From February To August 2017

Particulate Matter, representing fine particles with diameters smaller than 2.5 mu m (PM 2.5), are considered to be harmful for both public health and environment. This paper estimated PM 2.5 concentrations in British Columbia (BC), Canada from February to August 2017 in order to compare PM 2.5 levels before and after wildfires by using ground-level PM 2.5 measurements, 3 km Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol optical depth (AOD) products and the Geographically Weighted Regression (GWR) model. Additional meteorological data was also utilized to perfect the model. The results showed that the variation of AOD highly represents the distribution of PM 2.5, and PM 2.5 concentrations in July and August were much higher than previous month, which indicated that there was a rapid increase in PM 2.5 levels after the wildfires. In addition, the results also demonstrated that the 3 km MODIS AOD products have high accuracy on providing spatial information when estimating PM 2.5 levels.