Unprecedented NH 3 emissions detected in the high-Arctic from the 2017 Canadian wildfires

• Main Authors: Lutsch, Erik, Strong, Kimberly, Jones, Dylan B. A., Ortega, Ivan, Hannigan, James W., Dammers, Enrico, Shephard, Mark, S., Morris, Eleanor Rose, Murphy, Killian, Evans, Mathew J., Parrington, Mark, Whitburn, Simon, Damme, Martin Van, Clarisse, Lieven, Coheur, Pierre-François, Clerbaux, Cathy, Croft, Betty, Martin, Randall, Wentworth, Greg, Zhu, Lei, Fisher, Jenny A.
• Other Authors: Department of Physics Toronto, University of Toronto, National Center for Atmospheric Research Boulder (NCAR), Atmospheric Chemistry Observations and Modeling Laboratory (ACOML), Environment and Climate Change Canada, York University Toronto, Wolfson Atmospheric Chemistry Laboratories (WACL), University of York York, UK, European Centre for Medium-Range Weather Forecasts (ECMWF), Spectroscopie de l'atmosphère, Service de Chimie Quantique et Photophysique, Université libre de Bruxelles (ULB), TROPO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Department of Physics and Atmospheric Science Halifax, Dalhousie University Halifax, Alberta Environment and Parks (AEP), Harvard University, School of Earth and Environmental Sciences Wollongong, Faculty of Science, Medicine and Health Wollongong, University of Wollongong Australia -University of Wollongong Australia
• Format: Conference Object
• Language: English
• Published: HAL CCSD 2018
• Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; Arctic; Nunavut; Northwest Territories; Greenland; Eureka; Thule
• Online Access: https://insu.hal.science/insu-01967905

International audience From August 17-22, 2017, simultaneous enhancements of ammonia (NH3), carbon monoxide (CO), hydrogen cyanide (HCN) and ethane (C2H6) were detected from ground-based solar absorption Fourier-transform infrared (FTIR) spectroscopic measurements at two high-Arctic sites: Eureka, Nunavut (80.05N, 86.42W) and Thule, Greenland (76.53N, 68.74W). These enhancements were attributed to wildfires in British Columbia and the Northwest Territories using FLEXPART back-trajectories and fire locations from MODIS and found to be the greatest observed enhancements in more than a decade of measurements at Eureka (2006-present) and Thule (1999-present). Observations of gas-phase NH3 from these wildfires illustrates that NH3 may undergo long-range transport and therefore wildfires may be a considerable source of NH3 in the summertime high-Arctic. However, the mechanisms leading to the long-range transport of wildfire emissions of NH3 and its potential impacts on the biosphere, air quality and climate of the high-Arctic are not well understood.In this study, enhancement ratios of NH3, HCN and C2H6 with respect to CO are calculated for fire-affected measurements at Eureka and Thule. The enhancement ratios of NH3, HCN and C2H6 are found to be different between sites and are observed to be strongly dependent on the time of measurement, which suggests that transport patterns of the smoke plume and differences in burning phase may have a strong influence on the measured concentrations of NH3. To further investigate these differences, satellite observations of NH3 and CO from the Infrared Atmospheric Sounding Instrument (IASI) are used to examine the spatial and temporal variabilities of NH3 during transport. Comparisons of IASI to high-resolution (0.25 x 0.3125) GEOS-Chem model results using Global Fire Assimilation System (GFAS) biomass burning emissions are also performed to evaluate the emission inventories and investigate the physical and chemical properties influencing the long-range transport of NH3 to the ...