@Article{WeiFGCTSKFAMVS:2018:EnBiCo,
author = "Wei, Dandan and Fuentes, Jose D. and Gerken, Tobias and Chamecki,
Marcelo and Trowbridge, Amy M. and Stoy, Paul C. and Katul,
Gabriel G. and Fisch, Gilberto and Acevedo, Ot{\'a}vio and Manzi,
Antonio Ocimar and Von Randow, Celso and Santos, Rosa Maria
Nascimento dos",
affiliation = "{The Pennsylvania State University} and {The Pennsylvania State
University} and {The Pennsylvania State University} and
{University of California} and {Montana State University} and
{Montana State University} and {Duke University} and {Instituto de
Aeron{\'a}utica e Espa{\c{c}}o (IAE)} and {Universidade Federal
de Santa Maria (UFSM)} and {Instituto Nacional de Pesquisas
Espaciais (INPE)} and {Instituto Nacional de Pesquisas Espaciais
(INPE)} and {Universidade do Estado do Amazonas (UEAM)}",
title = "Environmental and biological controls on seasonal patterns of
isoprene above a rain forest in central Amazonia",
journal = "Agricultural and Forest Meteorology",
year = "2018",
volume = "256",
pages = "391--406",
month = "June",
keywords = "Rainforest, Phenology, Isoprene, Oxidants, Chemistry, Hydroxyl.",
abstract = "The Amazon rain forest is a major global isoprene source, but
little is known about its seasonal ambient concentration patterns.
To investigate the environmental and phenological controls over
isoprene seasonality, we measured isoprene mixing ratios,
concurrent meteorological data, and leaf area indices from April
2014 to January 2015 above a rain forest in the central Amazon,
Brazil. Daytime median isoprene mixing ratios varied throughout
the year by a factor of two. The isoprene seasonal pattern was not
solely driven by sunlight and temperature. Leaf age and quantity
also contributed to the seasonal variations of isoprene
concentrations, suggesting leaf phenology was a crucial variable
needed to correctly estimate isoprene emissions. A
zero-dimensional model incorporating the estimated emissions,
atmospheric boundary layer dynamics, and air chemistry was used to
assess the contributions of each process on the variability of
isoprene. Surface deposition was an important sink mechanism and
accounted for 78% of the nighttime loss of isoprene. Also,
chemical reactions destroyed isoprene and during 6:00 to 18:00 h
local time 56, 77, 69, and 69% of the emitted isoprene was
chemically consumed in June, September, December, and January,
respectively. Entrainment fluxes from the residual layer
contributed 34% to the early-morning above-canopy isoprene mixing
ratios. Sensitivity analysis showed that hydroxyl radical (HO)
recycling and segregation of isoprene HO played relatively lesser
roles (up to 16%) in regulating ambient isoprene levels. Nitric
oxide (NO) levels dominated isoprene chemical reaction pathways
associated with consumption and production of HO under low-NO and
high volatile organic compound (VOC) conditions. While surface
deposition and oxidative processes altered isoprene levels, the
relative importance of these factors varied seasonally with leaf
phenology playing a more important role.",
doi = "10.1016/j.agrformet.2018.03.024",
url = "http://dx.doi.org/10.1016/j.agrformet.2018.03.024",
issn = "0168-1923",
language = "en",
targetfile = "Wei_environmental.pdf",
urlaccessdate = "27 abr. 2024"
}