GEM-AQ Modelling of Smoke Events Observed in the High Arctic at Eureka, Canada

Fine-mode aerosol events that could be traced back to forest fires in Siberia, Russia and Northwest Territories, Canada were observed during the summer of 2007 and spring of 2008 at the Polar Environment Atmospheric Research Laboratory (PEARL) located at Eureka on Ellesmere Island. The simulation of these events was performed with the Global Environmental Multiscale Air Quality model (GEM-AQ), a global, tropospheric chemistry, general circulation model based on the three-dimensional global variable-resolution multi-scale model developed by the Meteorological Service of Canada for operational weather prediction. GEM-AQ includes a size-resolved multi-component aerosol module. The chemical mechanism used in this study is comprised of 52 gas-phase species and 137 chemical and photolysis reactions. The model output is compared with vertical profiles from the Arctic High Spectral Resolution Lidar (AHSRL) and with spectral sunphotometer data acquired at Eureka, as well as with MODIS, CALIOP and OMI products over the Arctic. In addition, modelled tropospheric columns of carbon monoxide and ethane are compared with measurements made with the PEARL Fourier transform infrared spectrometer.