Use este identificador para citar ou linkar para este item: https://repositorio.inpa.gov.br/handle/1/14869
Título: Isoprene photochemistry over the Amazon rainforest
Autor: Liu, Yingjun
Brito, Joel F.
Dorris, Matthew R.
Rivera-Ríos, Jean C.
Seco, Roger
Bates, Kelvin H.
Artaxo, Paulo
Duvoisin, Sérgio Jr
Keutsch, Frank N.
Kim, Saewung
Goldstein, Allen H.
Guenther, Alex B.
Manzi, Antônio Ocimar
Souza, Rodrigo Augusto Ferreira de
Springston, Stephen R.
Watson, Thomas B.
McKinney, Karena A.
Martin, Scot T.
Palavras-chave: Acrolein Derivative
Isoprene
Isoprene Peroxy Radical
Ketone Derivative
Methacrolein
Methylvinyl Ketone
Nitric Oxide
Nitrogen Derivative
Unclassified Drug
1,3 Butadiene Derivative
3-buten-2-one
Acrolein
Air Pollutant
Alkanone
Free Radical
Hemiterpene
Isoprene
Methacrylaldehyde
Pentane
Peroxide
Air Pollution
Boundary Layer
Concentration (parameters)
Ionization
Isomerization
Limit Of Detection
Mass Spectrometry
Particulate Matter
Photochemistry
Photooxidation
Priority Journal
Rainforest
Reaction Analysis
Urban Area
Air Pollutant
Analogs And Derivatives
Analysis
Atmosphere
Chemistry
Human
Oxidation Reduction Reaction
Radiation Response
Acrolein
Air Pollutants
Atmosphere
Butadienes
Butanones
Free Radicals
Hemiterpenes
Humans
Nitric Oxide
Oxidation-reduction
Pentanes
Peroxides
Photochemistry
Rainforest
Data do documento: 2016
Revista: Proceedings of the National Academy of Sciences of the United States of America
É parte de: Volume 113, Número 22, Pags. 6125-6130
Abstract: Isoprene photooxidation is a major driver of atmospheric chemistry over forested regions. Isoprene reacts with hydroxyl radicals (OH) and molecular oxygen to produce isoprene peroxy radicals (ISOPOO). These radicals can react with hydroperoxyl radicals (HO2) to dominantly produce hydroxyhydroperoxides (ISOPOOH). They can also react with nitric oxide (NO) to largely produce methyl vinyl ketone (MVK) and methacrolein (MACR). Unimolecular isomerization and bimolecular reactions with organic peroxy radicals are also possible. There is uncertainty about the relative importance of each of these pathways in the atmosphere and possible changes because of anthropogenic pollution. Herein, measurements of ISOPOOH and MVK+MACR concentrations are reported over the central region of the Amazon basin during the wet season. The research site, downwind of an urban region, intercepted both background and polluted air masses during the GoAmazon2014/5 Experiment. Under background conditions, the confidence interval for the ratio of the ISOPOOH concentration to that of MVK+MACR spanned 0.4-0.6. This result implies a ratio of the reaction rate of ISOPOO with HO2 to that with NO of approximately unity. A value of unity is significantly smaller than simulated at present by global chemical transport models for this important, nominally low-NO, forested region of Earth. Under polluted conditions, when the concentrations of reactive nitrogen compounds were high (>1 ppb), ISOPOOH concentrations dropped below the instrumental detection limit (<60 ppt). This abrupt shift in isoprene photooxidation, sparked by human activities, speaks to ongoing and possible future changes in the photochemistry active over the Amazon rainforest.
DOI: 10.1073/pnas.1524136113
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