ESTIMATING PM _2.5 CONCENTRATIONS IN BRITISH COLUMBIA, CANADA DURING WILDFIRE SEASON USING SATELLITE OPTICAL DATA

British Columba, Canada experienced its record-breaking wildfire season in 2017. The wildfire smoke is one of the main sources of fine particles with diameters smaller than 2.5 μm (PM _2.5). The rising level of PM _2.5 concentrations during the wildfire season would considerable increase the risk of premature death, especially for people with weak immune systems. In this study, the satellite optical data collected from 3 km MODIS aerosol optical depth (AOD) products were adopted to estimate PM _2.5 concentration levels derived from wildfires in British Columbia, Canada from July to September 2017. The satellite optical data were combined with ground station measurements, meteorological and supplementary data to estimate PM _2.5 concentrations using the geographically weighted regression (GWR) model. Our results demonstrated that PM _2.5 concentrations were the highest in July and August based on the estimation results of seasonal and monthly GWR models. It indicated that the application feasibility of MODIS AOD products in predicting PM _2.5 concentrations during the wildfire season in British Columbia.