Utilize este identificador para referenciar este registo: http://hdl.handle.net/10400.3/1499
Título: Significant enhancements of nitrogen oxides, black carbon, and ozone in the North Atlantic lower free troposphere resulting from North American boreal wildfires
Autor: Val Martin, Maria
Honrath, Richard
Owen, R. Chris
Pfister, G.
Fialho, Paulo
Barata, Filipe
Palavras-chave: Nitrogen Oxides
Black Carbon
Free Troposphere
Boreal Fires
North Atlantic
Data: 7-Dez-2006
Editora: American Geophysical Union (AGU)
Citação: Val Martín, M.; Honrath, R.E.; Owen, R.C.; Pfister, G.; Fialho, P.; Barata, F. «Significant enhancements of nitrogen oxides, black carbon, and ozone in the North Atlantic lower free troposphere resulting from North American boreal wildfires», "Journal of Geophysical Research – Atmospheres", 111, D23S60-1- D23S60-17, 2006.
Resumo: Extensive wildfires burned in northern North America during summer 2004, releasing large amounts of trace gases and aerosols into the atmosphere. Emissions from these wildfires frequently impacted the PICO-NARE station, a mountaintop site situated 6–15 days downwind from the fires in the Azores Islands. To assess the impacts of the boreal wildfire emissions on the levels of aerosol black carbon (BC), nitrogen oxides and O3 downwind from North America, we analyzed measurements of CO, BC, total reactive nitrogen oxides (NO y ), NO x (NO + NO2) and O3 made from June to September 2004 in combination with MOZART chemical transport model simulations. Long-range transport of boreal wildfire emissions resulted in large enhancements of CO, BC, NO y and NO x , with levels up to 250 ppbv, 665 ng mˉ³, 1100 pptv and 135 pptv, respectively. Enhancement ratios relative to CO were variable in the plumes sampled, most likely because of variations in wildfire emissions and removal processes during transport. Analyses of ΔBC/ΔCO, ΔNO y /ΔCO and ΔNO x /ΔCO ratios indicate that NO y and BC were on average efficiently exported in these plumes and suggest that decomposition of PAN to NO x was a significant source of NO x . High levels of NO x suggest continuing formation of O3 in these well-aged plumes. O3 levels were also significantly enhanced in the plumes, reaching up to 75 ppbv. Analysis of ΔO3/ΔCO ratios showed distinct behaviors of O3 in the plumes, which varied from significant to lower O3 production. We identify several potential reasons for the complex effects of boreal wildfire emissions on O3 and conclude that this behavior needs to be explored further in the future. These observations demonstrate that boreal wildfire emissions significantly contributed to the NO x and O3 budgets in the central North Atlantic lower free troposphere during summer 2004 and imply large-scale impacts on direct radiative forcing of the atmosphere and on tropospheric NO x and O3.
Descrição: Copyright © 2006 American Geophysical Union. All Rights Reserved.
Peer review: yes
URI: http://hdl.handle.net/10400.3/1499
ISSN: 0148-0227 (Print)
2156–2202 (Online)
Versão do Editor: http://www.agu.org/pubs/crossref/2006/2006JD007530.shtml
Aparece nas colecções:DCA - Artigos em Revistas Internacionais / Articles in International Journals

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