@Article{LiuBDRSBADKKGGMSSWMM:2016:IsPhOv,
author = "Liu, Yingjun and Brito, Joel and Dorris, Matthew R. and
Rivera-Rios, Jean C. and Seco, Roger and Bates, Kelvin H. and
Artaxo, Paulo and Duvoisin, Sergio and Keutsch, Frank N. and Kim,
Saewung and Goldstein, Allen H. and Guenther, Alex B. and Manzi,
Antonio Ocimar and Souza, Rodrigo Augusto Ferreira de and
Springston, Stephen R. and Watson, Thomas B. and Mckinney, Karena
A. and Martin, Scot T.",
affiliation = "{Harvard University} and {Universidade de S{\~a}o Paulo (USP)}
and {University of Wisconsin-Madison} and {University of
Wisconsin-Madison} and {University of California} and {California
Institute of Technology} and {Universidade de S{\~a}o Paulo
(USP)} and {Universidade do Estado do Amazonas} and {Harvard
University} and {University of California} and {University of
California} and {University of California} and {Instituto Nacional
de Pesquisas Espaciais (INPE)} and {Universidade do Estado do
Amazonas (UEAM)} and {Brookhaven National Laboratory} and
{Brookhaven National Laboratory} and {Harvard University} and
{Harvard University}",
title = "Isoprene photochemistry over the Amazon rainforest",
journal = "Proceedings of the National Academy of Sciences of the United
Sates of America",
year = "2016",
volume = "113",
number = "22",
pages = "6125--6130",
month = "May",
keywords = "isoprene photochemistry, Amazon, organic hydroperoxides.",
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 0.40.6. 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",
url = "http://dx.doi.org/10.1073/pnas.1524136113",
issn = "0027-8424",
label = "lattes: 0575383574431005 13 LiuBDRSBADKKGGMSSWMM:2016:IsPhOv",
language = "en",
targetfile = "liu_isoprene.pdf",
urlaccessdate = "27 abr. 2024"
}