@PhDThesis{Sobral:2019:CaFlIs,
author = "Sobral, Anahi Chimini",
title = "Caracteriza{\c{c}}{\~a}o dos fluxos de isopreno nos biomas
Amaz{\^o}nia, Cerrado e Pantanal",
school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
year = "2019",
address = "S{\~a}o Jos{\'e} dos Campos",
month = "2019-05-28",
keywords = "Intera{\c{c}}{\~a}o biosfera-atmosfera, isopreno, biomas
brasileiros, biosphere-atmosphere interaction, isoprene, brazilian
biomes.",
abstract = "No Brasil, a vegeta{\c{c}}{\~a}o natural da Amaz{\^o}nia,
Cerrado e Pantanal t{\^e}m grande import{\^a}ncia quanto {\`a}
emiss{\~a}o de compostos org{\^a}nicos vol{\'a}teis
biog{\^e}nicos, principalmente o isopreno, com conhecimento
abundante para a Amaz{\^o}nia, mas com informa{\c{c}}{\~o}es
ainda pouco conhecidas para Cerrado e Pantanal, requerendo
esfor{\c{c}}os para estimar as emiss{\~o}es de isopreno nessas
{\'a}reas. Considerando essa car{\^e}ncia de
informa{\c{c}}{\~a}o, esta tese investiga e descreve o
comportamento das concentra{\c{c}}{\~o}es de isopreno em
diferentes forma{\c{c}}{\~o}es vegetais brasileiras. Para tanto,
foram realizadas incurs{\~o}es a campo na Amaz{\^o}nia e
Pantanal, com coleta de amostras de ar para
quantifica{\c{c}}{\~a}o da concentra{\c{c}}{\~a}o de isopreno
e dados ambientais para cada bioma. A partir dos dados obtidos
foram realizadas simula{\c{c}}{\~o}es das emiss{\~o}es de
isopreno utilizando o modelo MEGAN, vers{\~a}o beta 2.1,
al{\'e}m de um estudo explorando fluxos futuros de emiss{\~a}o
de isopreno para as {\'a}reas de estudo. Ao estudar a raz{\~a}o
de mistura do isopreno, foi poss{\'{\i}}vel identificar que a
raz{\~a}o de mistura no Pantanal {\'e} menor que na
Amaz{\^o}nia (9,19 ± 4,73 ppb) durante a {\'e}poca seca. Isso
foi atribu{\'{\i}}do n{\~a}o somente {\`a} import{\^a}ncia do
tipo de vegeta{\c{c}}{\~a}o, mas tamb{\'e}m {\`a}s
condi{\c{c}}{\~o}es ambientais locais, que podem ter
influenciado os mecanismos de produ{\c{c}}{\~a}o do isopreno. No
caso do Pantanal ainda foi identificada uma diferen{\c{c}}a
estatisticamente significativa entre as campanhas realizadas em
2016 (2,17 ± 0,61 ppb) e 2017 (0.60 ± 0,27 ppb), o que pode ter
ocorrido devido ao impacto do grande n{\'u}mero de queimadas
registradas em 2017. Ao comparar as emiss{\~o}es estimadas de
isopreno nos tr{\^e}s biomas para o per{\'{\i}}odo analisado, a
Amaz{\^o}nia desponta como o bioma cujo fluxo de isopreno {\'e}
maior, seguido por Pantanal e Cerrado, tanto para as estimativas
geradas pelo MEGAN (9,39, 4,08 e 2,50 mg m-2 h-1,
respectivamente), quanto as derivadas pela coluna de
formalde{\'{\i}}do (2,45, 1,66 e 0,69 mg m-2 h-1,
respectivamente). Apesar de superestimar as emiss{\~o}es, o
modelo MEGAN representou de maneira muito satisfat{\'o}ria a
sazonalidade nos fluxos de isopreno para os biomas estudados.
Quando se comparam as emiss{\~o}es m{\'e}dias anuais de isopreno
estimadas pelo MEGAN em termos de contribui{\c{c}}{\~a}o por
biomas, por conta da sua extens{\~a}o, o Pantanal apresenta a
menor contribui{\c{c}}{\~a}o. Amaz{\^o}nia, Cerrado e Pantanal
contribuem, respectivamente, com 334,15, 42,76 e 5,26 Tg isopreno
ano-1. As simula{\c{c}}{\~o}es das emiss{\~o}es de isopreno
frente a um poss{\'{\i}}vel cen{\'a}rio de mudan{\c{c}}a no
clima tamb{\'e}m apontaram para uma redu{\c{c}}{\~a}o em
aproximadamente 10 % nas emiss{\~o}es, j{\'a} que o aumento da
concentra{\c{c}}{\~a}o do CO2 atmosf{\'e}rico exerce um efeito
inibidor das emiss{\~o}es, sobrepondo-se ao est{\'{\i}}mulo
fornecido pelo aumento da temperatura. ABSTRACT: In Brazil, the
natural vegetation of the Amazon, Cerrado and Pantanal biomes
presents great importance for the biogenic volatile organic
compounds emission, mainly isoprene, with abundant knowledge for
the Amazon, but with information not yet known for Cerrado and
Pantanal, requiring efforts to estimate isoprene emissions in
these areas. Considering this lack of information, this study
investigates and describes the behavior of isoprene concentrations
in different Brazilian biomes. For this purpose, field trips were
carried out in the Amazon and Pantanal. In order to quantify the
isoprene concentration, air samples were collected and the diurnal
cycle of isoprene mixing ratio was analyzed in correlation to
environmental parameters. Besides, in order to understand the
isoprene emission behavior and magnitude for each biome, the MEGAN
model, beta version 2.1, was used to simulate the emission. The
MEGAN model was also used to explore future trends in isoprene
emission for the study areas. By studying the isoprene mixing
ratio of isoprene, it was possible to identify that the mixing
ratio in the Pantanal is lower than in the Amazon (9,19 ± 4,73
ppb) during the dry season. This was attributed not only to the
vegetation type, but also to local environmental conditions, which
may have influenced the isoprene production mechanisms. In the
case of Pantanal, a statistically significant difference between
the campaigns carried out in 2016 (2,17 ± 0,61 ppb) and 2017 (0,60
± 0,27 ppb) was also identified, which may have occurred due to
the impact of the large number of fires registered in 2017. When
comparing the isoprene estimated emissions in the three biomes for
the analyzed period, the Amazon emerges as the biome whose
isoprene flux is higher, followed by Pantanal and Cerrado, both
for the MEGAN (9.39, 4.08 and 2.50 mg m-2 h-1, respectively) and
those derived from the formaldehyde column (2.45, 1.66 and 0.69 mg
m-2 h-1, respectively). Despite MEGAN overestimated the isoprene
flux, the model represented the flux seasonality very
satisfactorily, for the analyzed period. When comparing the annual
average isoprene emissions estimated by MEGAN in terms of biome
contribution, Pantanal, due to its extension, presents the
smallest contribution. Amazon, Cerrado and Pantanal contribute,
respectively, with 334,15, 42,76 and 5,26 Tg isoprene year-1. The
isoprene emission simulations in a possible climate change
scenario shows a reduction of approximately 10 % in the emissions
as a consequence of the atmospheric CO2 concentration increase,
which has an inhibitory effect on emissions, overlapping the
effect provided by the increase in temperature.",
committee = "Forti, Maria Cristina (presidente) and Alval{\'a},
Pl{\'{\i}}nio Carlos (orientador) and von Randow, Celso
(orientador) and Manzi, Antonio Ocimar and Pav{\~a}o, Hamilton
Germano and Santos, Fernando Cavalcante",
englishtitle = "Characterization of isoprene flux in the Amazon, Cerrado and
Pantanal biomes",
language = "pt",
pages = "120",
ibi = "8JMKD3MGP3W34R/3T9JTTP",
url = "http://urlib.net/ibi/8JMKD3MGP3W34R/3T9JTTP",
targetfile = "publicacao.pdf",
urlaccessdate = "27 abr. 2024"
}