@PhDThesis{Rodrigues:2023:COFlRe,
author = "Rodrigues, Celina C{\^a}ndida Ferreira",
title = "The CO2 fluxes and their relationship to environmental conditions
on the Southwest Atlantic Ocean and its southern ocean sector",
school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
year = "2023",
address = "S{\~a}o Jos{\'e} dos Campos",
month = "2022-12-19",
keywords = "CO2 flux, bulk methodology, eddy covariance, Southwest Atlantic
Ocean, Southern Ocean, fluxo de CO2, metodologia bulk,
covari{\^a}ncia de vort{\'{\i}}ces turbulentos, Oceano
Atl{\^a}ntico Sudoeste, Oceano Austral.",
abstract = "The oceans play an important role in mitigating climate change by
acting as large carbon sinks, especially at middle and high
latitude regions. The main objective of this work is to
investigate the behavior of turbulent CO2 fluxes at medium- and
high-latitude under different atmospheric and oceanic conditions,
during the trajectories of research ships to the Southwest
Atlantic Ocean and its portion in the Southern Ocean. The CO2 flux
was calculated using the eddy covariance and bulk methodology.
During the experiment the Brazil Current sink more CO2 than
Malvinas Current, owing to its proximity to the chlorophyll-rich
and less saline waters of the La Plata River, and intense wind
speeds increased the CO2 flux between the ocean and atmosphere.
The Brazil Malvinas Confluence also behaved as a CO2 sink, and the
modulation of CO2 fluxes was due to the intense horizontal
gradient of SST together with the moderate surface wind and
turbulence. The MC sequestered less carbon than other regions
because of the presence of a high-pressure system near the region,
low atmospheric turbulence, and light surface winds that inhibited
mass exchange between the ocean and atmosphere. The Bransfield
Strait uptake 38.59% more CO2 than the Drake Passage due to the
cold and fresh waters, allied to the influence of glacial
meltwater dilution. The Drake Passage, on average, behaved as a
CO2 sink, mainly due to physical characteristics. To minimize the
uncertainty in bulk methodology for CO2 flux, we found the best
fit for the gas transfer coefficient was K = 0.2325*u2 0.4361*u+
1.764 with R2 of 0.97, and it showed an adequate representation of
ocean-atmosphere fluxes for Southwest Atlantic Ocean. The bulk
methodology the purpose gas transfer coefficient had good
agreement with the in situ data (eddy covariance) for the ACEx and
and Antarctic Operations 32, 33, 34, and 37 (2012 to 2018). The
Southwest Atlantic Ocean had been increasing the assimilation of
carbon along the years analyzed (2003 to 2020), mainly due to the
increase of CO2 concentration in the atmosphere. This research
contributes to a better understanding of the Southwest Atlantic
Ocean and Southern Oceans role in the global carbon balance.
RESUMO: Os oceanos desempenham um papel importante na
mitiga{\c{c}}{\~a}o das mudan{\c{c}}as clim{\'a}ticas, atuando
como grandes sumidouros de carbono, especialmente nas regi{\~o}es
de latitudes m{\'e}dias e altas. O principal objetivo deste
trabalho {\'e} investigar o comportamento dos fluxos turbulentos
de CO2 em latitudes m{\'e}dias e altas sob diferentes
condi{\c{c}}{\~o}es atmosf{\'e}ricas e oce{\^a}nicas, durante
as trajet{\'o}rias de navios de pesquisa para o Oceano
Atl{\^a}ntico Sudoeste e sua por{\c{c}}{\~a}o no Oceano
Austral. O fluxo de CO2 foi calculado usando a covari{\^a}ncia de
v{\'o}rtices turbulentos e a metodologia bulk. Durante o
experimento, a Corrente do Brasil sequestrou mais CO2 do que a
Corrente das Malvinas, devido {\`a} sua proximidade com as
{\'a}guas ricas em clorofila e menos salinas do Rio da Prata, e
ventos intensos aumentaram o fluxo de CO2 entre o oceano e a
atmosfera. A Conflu{\^e}ncia Brasil Malvinas tamb{\'e}m se
comportou como um sumidouro de CO2, devido ao intenso gradiente
horizontal de temperatura da superf{\'{\i}}cie do mar, junto com
ventos moderados e turbul{\^e}ncia. A corrente das Malvinas
sequestrou menos carbono do que outras regi{\~o}es devido {\`a}
presen{\c{c}}a de um sistema de alta press{\~a}o pr{\'o}ximo
{\`a} regi{\~a}o, baixa turbul{\^e}ncia e ventos fracos na
superf{\'{\i}}cie que inibiram a troca de massa entre o oceano e
a atmosfera. O Estreito de Bransfield absorveu 38,59% mais CO2 do
que a Passagem de Drake devido {\`a}s {\'a}guas frias e menos
salinas, aliadas {\`a} influ{\^e}ncia do degelo glacial. A
Passagem de Drake, em m{\'e}dia, comportouse como um sumidouro de
CO2, principalmente devido {\`a}s caracter{\'{\i}}sticas
f{\'{\i}}sicas. Para minimizar as incertezas na metodologia bulk
para o c{\'a}lculo do fluxo de CO2, encontramos o melhor ajuste
para o coeficiente de transfer{\^e}ncia de g{\'a}s foi K =
0,2325*u2 0,4361*u+ 1,764 com R2 de 0,97, esse mostrou uma
representa{\c{c}}{\~a}o adequada dos fluxos para o
Atl{\^a}ntico Sudoeste. A metodologia de bulk, aplicando o
coeficiente de transfer{\^e}ncia de g{\'a}s proposto, teve boa
concord{\^a}ncia com os dados in situ (covari{\^a}ncia de
v{\'o}rtices turbulentos) para o ACEx e para as
Opera{\c{c}}{\~o}es Ant{\'a}rticas 32, 33, 34 e 37 (2012 a
2018). O Oceano Atl{\^a}ntico Sudoeste vem aumentando a
assimila{\c{c}}{\~a}o de carbono ao longo dos anos analisados
(2003 a 2020), principalmente devido ao aumento da
concentra{\c{c}}{\~a}o de CO2 na atmosfera. Esta pesquisa
contribui para uma melhor compreens{\~a}o do papel do Oceano
Atl{\^a}ntico Sudoeste e do Oceano Austral no balan{\c{c}}o
global de carbono.",
committee = "Valeriano, M{\'a}rcio de Morisson (presidente) and Pezzi, Luciano
Ponzi (orientador) and Santini, Marcelo Freitas (orientador) and
Cunha, Leticia Cotrim da and Lef{\`e}vre, Nathalie",
englishtitle = "Os fluxos de CO2 e sua rela{\c{c}}{\~a}o com as
condi{\c{c}}{\~o}es ambientais no Oceano Atl{\^a}ntico Sudoeste
e seu setor no Oceano Austral",
language = "en",
pages = "75",
ibi = "8JMKD3MGP3W34T/48GESAL",
url = "http://urlib.net/ibi/8JMKD3MGP3W34T/48GESAL",
targetfile = "publicacao.pdf",
urlaccessdate = "20 maio 2024"
}