Transport Regimes of Air Masses Affecting the Tropospheric Composition of the Canadian and European Arctic During RACEPAC 2014 and NETCARE 2014/2015

Monday, 14 December 2015
Poster Hall (Moscone South)
Heiko Bozem1, Peter Michael Hoor1, Franziska Koellner1, Daniel Kunkel2, Johannes Schneider3, Christiane Schulz3, Andreas Bodo Herber4, Stephan Borrmann5, Manfred Wendisch6, André Ehrlich6, Warren Richard Leaitch7, Megan D Willis8, Julia Burkart9, Jennie L Thomas10 and Jonathan Abbatt8, (1)Johannes Gutenberg University of Mainz, Institute for Atmospheric Physics, Mainz, Germany, (2)Johannes Gutenberg University of Mainz, Mainz, Germany, (3)Max Planck Institute for Chemistry, Particle Chemistry Department, Mainz, Germany, (4)Alfred Wegener Institute Helmholtz-Center for Polar and Marine Research Bremerhaven, Sea Ice Physics, Bremerhaven, Germany, (5)Max Planck Institute for Chemistry, Mainz, Germany, (6)University of Leipzig, Leipzig Institute for Meteorology, Leipzig, Germany, (7)Environment Canada Toronto, Climate Research Division, Toronto, ON, Canada, (8)University of Toronto, Department of Chemistry, Toronto, ON, Canada, (9)University of Toronto, Chemistry, Toronto, ON, Canada, (10)University Pierre and Marie Curie Paris VI, Paris, France
The Arctic is warming much faster than any other place in the world and undergoes a rapid change dominated by a changing climate in this region. The impact of polluted air masses traveling to the Arctic from various remote sources significantly contributes to the observed climate change, in contrast there are additional local emission sources contributing to the level of pollutants (trace gases and aerosol). Processes affecting the emission and transport of these pollutants are not well understood and need to be further investigated.

We present aircraft based trace gas measurements in the Arctic during RACEPAC (2014) and NETCARE (2014 and 2015) with the Polar 6 aircraft of Alfred Wegener Institute (AWI) covering an area from 134°W to 17°W and 68°N to 83°N. We focus on cloud, aerosol and general transport processes of polluted air masses into the high Arctic.

Based on CO and CO2 measurements and kinematic 10-day back trajectories we analyze the transport regimes prevalent during spring (RACEPAC 2014 and NETCARE 2015) and summer (NETCARE 2014) in the observed region. Whereas the eastern part of the Canadian Arctic is affected by air masses with their origin in Asia, in the central and western parts of the Canadian and European Arctic air masses from North America are predominant at the time of the measurement. In general the more northern parts of the Arctic were relatively unaffected by pollution from mid-latitudes since air masses mostly travel within the polar dome, being quite isolated. Associated mixing ratios of CO and CO2 fit into the seasonal cycle observed at NOAA ground stations throughout the Arctic, but show a more mid-latitudinal characteristic at higher altitudes. The transition is remarkably sharp and allows for a chemical definition of the polar dome. At low altitudes, synoptic disturbances transport polluted air masses from mid-latitudes into regions of the polar dome. These air masses contribute to the Arctic pollution background, but also contain single pollution plumes that perturb the background tracer distribution. These plumes could be traced back to biomass burning or flaring in remote regions, as well as local ship emissions within the measurement region.