Long-range transport and mixing of aerosol sources during the 2013 North American biomass burning episode: analysis of multiple lidar observations in the western Mediterranean basin

• Published in: Atmospheric chemistry and physics Vol. 16; no. 7; pp. 4725 - 4742
• Main Authors: Ancellet, Gerard, Pelon, Jacques, Totems, Julien, Chazette, Patrick, Bazureau, Ariane, Sicard, Michaël, Di Iorio, Tatiana, Dulac, Francois, Mallet, Marc
• Format: Journal Article Publication
• Language: English
• Published: Katlenburg-Lindau Copernicus GmbH 15.04.2016; European Geosciences Union; Copernicus Publications
• Subjects: Absorption; Aerosol layers; Aerosol optical depth; Aerosol optical properties; Aerosols; Airborne lidar; Airborne sensing; Aircraft; Aircraft components; Analysis; Atmospheric and Oceanic Physics; Atmospheric particulates; Backscatter; Backscattering; Biomass; Biomass burning; Burning; Campaign; Carbon; Computer simulation; Depolarization; Deposition; Dust; Dust storms; Enginyeria de la telecomunicació; Fire emissions; Fires; Forest; Forest & brush fires; Free troposphere; Ground-based observation; Horizontal distribution; Lidar; Lidar measurements; Long-range transport; MODIS; Optical analysis; Optical properties; Optical radar; Optical thickness; Outflow; Physics; Radiocomunicació i exploració electromagnètica; Remote sensing; Saharan dust; Satellite observation; Satellites; Storms; Streamers; Teledetecció; Three dimensional models; Trade winds; Transport; Westerlies; Wind; Àrees temàtiques de la UPC; Mediterranean Sea; Canada; Manitoba Canada; United States > US; Europe; Colorado; Lampedusa; North America; Mediterranean Area; ChArMEx
• ISSN: 1680-7324; 1680-7316; 1680-7324
• DOI: 10.5194/acp-16-4725-2016

Long-range transport of biomass burning (BB) aerosols between North America and the Mediterranean region took place in June 2013. A large number of ground-based and airborne lidar measurements were deployed in the western Mediterranean during the Chemistry-AeRosol Mediterranean EXperiment (ChArMEx) intensive observation period. A detailed analysis of the potential North American aerosol sources is conducted including the assessment of their transport to Europe using forward simulations of the FLEXPART Lagrangian particle dispersion model initialized using satellite observations by MODIS and CALIOP. The three-dimensional structure of the aerosol distribution in the ChArMEx domain observed by the ground-based lidars (Minorca, Barcelona and Lampedusa), a Falcon-20 aircraft flight and three CALIOP tracks, agrees very well with the model simulation of the three major sources considered in this work: Canadian and Colorado fires, a dust storm from western US and the contribution of Saharan dust streamers advected from the North Atlantic trade wind region into the westerlies region. Four aerosol types were identified using the optical properties of the observed aerosol layers (aerosol depolarization ratio, lidar ratio) and the transport model analysis of the contribution of each aerosol source: (i) pure BB layer, (ii) weakly dusty BB, (iii) significant mixture of BB and dust transported from the trade wind region, and (iv) the outflow of Saharan dust by the subtropical jet and not mixed with BB aerosol. The contribution of the Canadian fires is the major aerosol source during this episode while mixing of dust and BB is only significant at an altitude above 5 km. The mixing corresponds to a 20–30 % dust contribution in the total aerosol backscatter. The comparison with the MODIS aerosol optical depth horizontal distribution during this episode over the western Mediterranean Sea shows that the Canadian fire contributions were as large as the direct northward dust outflow from Sahara.