Cross-polar transport and scavenging of Siberian aerosols containing black carbon during the 2012 ACCESS summer campaign

• Published in: Atmospheric Chemistry and Physics
• Main Authors: Raut, Jean-Christophe, Marelle, Louis, Fast, Jerome D., Thomas, Jennie L., Weinzierl, Bernadett, Law, Kathy S., Berg, Larry K., Roiger, Anke, Easter, Richard C., Heimerl, Katharina, Onishi, Tatsuo, Delanoë, Julien, Schlager, Hans
• Other Authors: TROPO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Pacific Northwest National Laboratory (PNNL), DLR Institut für Physik der Atmosphäre (IPA), Deutsches Zentrum für Luft- und Raumfahrt Oberpfaffenhofen-Wessling (DLR), Meteorologisches Institut München (MIM), Ludwig-Maximilians-Universität München (LMU), SPACE - LATMOS, European Union, Centre National de la Recherche Scientifique CNRS (PARCS (Pollution in the Arctic System)), European Project: 265863,EC:FP7:TPT,FP7-OCEAN-2010,ACCESS(2011)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2017
• Subjects: [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]; Arctic; Arctic Ocean; Svalbard; Svalbard Archipelago; black carbon; Siberia
• Online Access: https://hal-insu.archives-ouvertes.fr/insu-01433803; https://hal-insu.archives-ouvertes.fr/insu-01433803/document; https://hal-insu.archives-ouvertes.fr/insu-01433803/file/acp-17-10969-2017.pdf; https://doi.org/10.5194/acp-17-10969-2017

International audience During the ACCESS airborne campaign in July 2012, extensive boreal forest fires resulted in significant aerosol transport to the Arctic. A 10 day episode combining intense biomass burning over Siberia and low-pressure systems over the Arctic Ocean resulted in efficient transport of plumes containing black carbon (BC) towards the Arctic, mostly in the upper troposphere (6–8 km). A combination of in situ observations (DLR Falcon aircraft), satellite analysis and WRF-Chem simulations are used to understand the vertical and horizontal transport mechanisms of BC with a focus on the role of wet removal. Between the northwestern Norwegian coast and the Svalbard archipelago, the Falcon aircraft sampled plumes with enhanced CO concentrations up to 200 ppbv and BC mixing ratios up to 25 ng kg −1 . During transport to the Arctic region, a large fraction of BC particles are scavenged by two wet deposition processes, namely wet removal by large-scale precipitation and removal in wet convective updrafts, with both processes contributing almost equally to the total accumulated deposition of BC. Our results underline that applying a finer horizontal resolution (40 instead of 100 km) improves the model performance, as it significantly reduces the overestimation of BC levels observed at a coarser resolution in the mid-troposphere. According to the simulations at 40 km, the transport efficiency of BC (TE BC ) in biomass burning plumes is about 60 %, which is impacted by small accumulated precipitation along trajectory (APT) (1 mm). In contrast TE BC is very small (< 30 %) and APT is larger (5–10 mm) in plumes influenced by urban anthropogenic sources and flaring activities in Northern Russia, resulting in transport to lower altitudes. TE BC due to grid scale precipitation is responsible for a sharp meridional gradient in the distribution of BC concentrations. Wet removal in subgrid parameterized clouds (cumuli) is the cause of modeled vertical gradient of TE BC , especially in the mid-latitudes, reflecting ...