The Polar Environment Atmospheric Research Laboratory (PEARL) in Eureka, Nunavut (80.05N, 86.42W) on Ellesmere Island houses a ground-based Fourier-transform infrared (FTIR) spectrometer that measures solar-absorption spectra during clear-sky daylight hours. Trace gas abundances are retrieved from the measured spectra by the use of the SFIT4 retrieval algorithm as part of the Network for the Detection of Atmospheric Composition Change (NDACC). From FTIR measurements at PEARL, detection of enhancements of the long-lived tracer species carbon monoxide (CO), hydrogen cyanide (HCN) and ethane (C<sub>2</sub>H<sub>6</sub>) during the summer months are indicative of pollution from wildfire events. The short-lived species acetylene (C<sub>2</sub>H<sub>2</sub>), formic acid (HCOOH), methanol (CH<sub>3</sub>OH), formaldehyde (H<sub>2</sub>CO) and ammonia (NH<sub>3</sub>) are also retrieved. Back-trajectories from HYSPLIT and FLEXPART as well as fire detections from the Moderate Resolution Imaging Spectroradiometer (MODIS) allow the source of the detected enhancements to be determined. Measurements provided by other high and mid-latitude NDACC FTIR instruments provide additional information about long-range transport and pathways to the Arctic. Differences in travel times between sites allows ageing of biomass burning plumes to be determined, providing a means to infer the physical and chemical processes affecting the loss of each species during transport. The GEOS-Chem chemical transport model is also used to further investigate these processes and the influence of wildfire emissions on the Arctic.
Air Pollution in the Arctic: Climate, Environment and Societies