Forest fire plumes over the North Atlantic: p‐TOMCAT model simulations with aircraft and satellite measurements from the ITOP/ICARTT campaign

Abstract

[1] Intercontinental Transport of Ozone and Precursors (ITOP) (part of International Consortium for Atmospheric Research on Transport and Transformation (ICARTT)) was an intense research effort to measure long-range transport of pollution across the North Atlantic and its impact on O 3 production. During the aircraft campaign plumes were encountered containing large concentrations of CO plus other tracers and aerosols from forest fires in Alaska and Canada. A chemical transport model, p-TOMCAT, and new biomass burning emissions inventories are used to study the emissions long-range transport and their impact on the troposphere O 3 budget. The fire plume structure is modeled well over long distances until it encounters convection over Europe. The CO values within the simulated plumes closely match aircraft measurements near North America and over the Atlantic and have good agreement with MOPITT CO data. O 3 and NO x values were initially too great in the model plumes. However, by including additional vertical mixing of O 3 above the fires, and using a lower NO 2 /CO emission ratio (0.008) for boreal fires, O 3 concentrations are reduced closer to aircraft measurements, with NO 2 closer to SCIAMACHY data. Too little PAN is produced within the simulated plumes, and our VOC scheme's simplicity may be another reason for O 3 and NO x modeldata discrepancies. In the p-TOMCAT simulations the fire emissions lead to increased tropospheric O 3 over North America, the north Atlantic and western Europe from photochemical production and transport. The increased O 3 over the Northern Hemisphere in the simulations reaches a peak in July 2004 in the range 2.0 to 6.2 Tg over a baseline of about 150 Tg.Citation: Cook, P. A., et al. (2007), Forest fire plumes over the North Atlantic: p-TOMCAT model simulations with aircraft and satellite measurements from the ITOP/ICARTT campaign,

Tropospheric ozone and its precursors from the urban to the global scale from air quality to short-lived climate forcer

“…Photochemical impact remains uncertain. Clearly, long-range-transported biomass burning plumes can influence Europe (Cook et al, 2007;Real et al, 2007), though the impact is variable (Hudman et al, 2004). More recently, European fires in Portugal and Russia have been shown to contribute to air pollution (Tressol et al, 2008;Martins et al, 2012), and the frequency is expected to increase with climate change (Carvalho et al, 2011).…”

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“…Model studies have also found that limiting fire emissions to the boundary layer underestimates their influence in downwind regions (Cook et al, 2007;Freitas et al, 2007;Brioude et al, 2009;Chen et al, 2009;Jian and Fu, 2014). More effort is needed to evaluate model simulation of ozone production from biomass burning emissions, in particular during the evolution of fire plumes and over regions that are dominated by biomass burning emissions (e.g., Mauzerall et al, 1998;Alvardo et al, 2010;Singh et al, 2010;Arnold et al, 2015).…”

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