The FireWork v2.0 air quality forecast system with biomass burning emissions from the Canadian Forest Fire Emissions Prediction System v2.03

Abstract

Abstract. Biomass burning activities can produce large quantities\nof smoke and result in adverse air quality conditions in regional\nenvironments. In Canada, the Environment and Climate Change Canada (ECCC)\noperational FireWork (v1.0) air quality forecast system incorporates\nnear-real-time biomass burning emissions to forecast smoke plumes from fire\nevents. The system is based on the ECCC operational Regional Air Quality\nDeterministic Prediction System (RAQDPS) augmented with near-real-time\nwildfire emissions using inputs from the Canadian Forest Service (CFS)\nCanadian Wildland Fire Information System (CWFIS). Recent improvements to\nthe representation of fire behaviour and fire emissions have been\nincorporated into the CFS Canadian Forest Fire Emissions Prediction System\n(CFFEPS) v2.03. This is a bottom-up system linked to CWFIS in which hourly\nchanges in biomass fuel consumption are parameterized with hourly forecasted\nmeteorology at fire locations. CFFEPS has now also been connected to\nFireWork. In addition, a plume-rise parameterization based on fire-energy\nthermodynamics is used to define the smoke injection height and the\ndistribution of emissions within a model vertical column. The new system,\nFireWork v2.0 (FireWork–CFFEPS), has been evaluated over North America for\nJuly–September\xa02017 and June–August\xa02018, which are both periods when western Canada\nexperienced historical levels of fire activity with poor air quality\nconditions in several cities as well as other fires affecting northern\nCanada and Ontario. Forecast results were evaluated against hourly surface\nmeasurements for the three pollutant species used to calculate the Canadian\nAir Quality Health Index (AQHI), namely PM 2.5 , O3 , and NO2 ,\nand benchmarked against the operational FireWork v1.0 system (FireWork-Ops).\nThis comparison shows improved forecast performance and predictive skills\nfor the FireWork–CFFEPS system. Modelled fire-plume injection heights from\nCFFEPS based on fire-energy thermodynamics show higher plume injection\nheights and larger variability. The changes in predicted fire emissions and\ninjection height reduced the consistent over-predictions of PM 2.5 and\n O3 seen in FireWork-Ops. On the other hand, there were minimal fire\nemission contributions to surface NO2 , and results from FireWork–CFFEPS\ndo not degrade NO2 forecast skill compared to the RAQDPS. Model\nperformance statistics are slightly better for Canada than for the US,\nwith lower errors and biases. The new system is still unable to capture the\nhourly variability of the observed values for PM 2.5 , but it captured\nthe observed hourly variability for O3 concentration adequately.\nFireWork–CFFEPS also improves upon FireWork-Ops categorical scores for\nforecasting the occurrence of elevated air pollutant concentrations in terms\nof false alarm ratio (FAR) and critical success index (CSI).