LUCAS GATTI DOMINGUES

LUCAS GATTI DOMINGUES

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Direct measurements can help to understand the changes in ecosystems
2023 - GATTI, LUCIANA; CUNHA, CAMILLA; MARANI, LUCIANO; CASSOL, HENRIQUE; MESSIAS, CASSIANO; ARAI, EGIDIO; SOLER, LUCIANA; ALMEIDA, CLAUDIO; SETZER, ALBERTO; DOMINGUES, LUCAS; DENNING, SCOTT; MILLER, JOHN; GLOOR, MANUEL; CORREIA, CAIO; CRISPIM, STEPHANE; CORREA, SERGIO; NEVES, RAIANE; SILVA, FRANCINE; MACHADO, GUILHERME
The Amazon is the largest rainforest on the planet and was an important carbon sink. The carbon sink is declining, mainly due to an increase in tree mortality as a result of deforestation, degradation, and local, regional and global climate change. In addition, deforestation and forest degradation reduce the ability of the Amazon rainforest to act as a carbon sink. CO2 Vertical Profiles (VP) were performed from 2010 to 2021 (805), using small aircraft at 4 locations: SAN (2.86° S 54.95° W), ALF (8.80° S 56.75° W), RBA (9.38° S 67.62° W) and from 2010 to 2012 on TAB (5.96° S 70.06° W) and since 2013 at TEF (3.39° S 65.55° W). The question if Amazonia is a carbon source or sink is an important role in the global carbon budget. Amazonia vertical profile annual mean derived from CO2 annual mean vertical profiles (VP subtracted from the background concentration: ΔVP) from the 4 studied sites can help to clarify this important question. The sampling frequency was approximately 2 times per month in each location, from 4.4 km height (a.s.l.) until near surface 300 m (a.s.l.), and usually carried out between 12:00 and 13:00 local time. The CO2 samples were analyzed at INPE's LaGEE (Greenhouse Gas Laboratory), in São Jose dos Campos. This result is a direct indication of the regional source in the global carbon budget, indeed there are well-known discrepancies from many studies using different methodologies (bottom-up, top-down techniques, and a wide variety of global, regional, and inversion models). In this study, we will present Carbon flux from the time series for the 4 sites and Amazon Carbon balance using the column budget technique, and analyze the correlations with various parameters related to climate, vegetation, deforestation, and biomass burning.
Increased Amazon carbon emissions mainly from decline in law enforcement
2023 - GATTI, LUCIANA V.; CUNHA, CAMILLA L.; MARANI, LUCIANO; CASSOL, HENRIQUE L.G.; MESSIAS, CASSIANO G.; ARAI, EGIDIO; DENNING, SCOTT A.; SOLER, LUCIANA S.; ALMEIDA, CLAUDIO; SETZER, ALBERTO; DOMINGUES, LUCAS G.; BASSO, LUANA S.; MILLER, JOHN B.; GLOOR, MANUEL; CORREIA, CAIO S.C.; TEJADA, GRACIELA; NEVES, RAIANE A.L.; RAJÃO, RAONI; NUNES, FELIPE; S.FILHO, BRITALDO S.; SCHMITT, JAIR; NOBRE, CARLOS; CORRÊA, SERGIO M.; SANCHES, ALBER H.; ARAGÃO, LUIZ E.O.C.; ANDERSON, LIANA; VON RANDOW, CELSO; CRISPIM, STEPHANE P.; SILVA, FRANCINE M.; MACHADO, GUILHERME B.M.
The Amazon forest carbon sink is declining, mainly as a result of land-use and climate change1–4. Here we investigate how changes in law enforcement of environmental protection policies may have affected the Amazonian carbon balance between 2010 and 2018 compared with 2019 and 2020, based on atmospheric CO2 vertical profiles5,6, deforestation7 and fire data8, as well as infraction notices related to illegal deforestation9. We estimate that Amazonia carbon emissions increased from a mean of 0.24 ± 0.08 PgC year−1 in 2010–2018 to 0.44 ± 0.10 PgC year−1 in 2019 and 0.52 ± 0.10 PgC year−1 in 2020 (± uncertainty). The observed increases in deforestation were 82% and 77% (94% accuracy) and burned area were 14% and 42% in 2019 and 2020 compared with the 2010–2018 mean, respectively. We find that the numbers of notifications of infractions against flora decreased by 30% and 54% and fines paid by 74% and 89% in 2019 and 2020, respectively. Carbon losses during 2019–2020 were comparable with those of the record warm El Niño (2015–2016) without an extreme drought event. Statistical tests show that the observed differences between the 2010– 2018 mean and 2019–2020 are unlikely to have arisen by chance. The changes in the carbon budget of Amazonia during 2019–2020 were mainly because of western Amazonia becoming a carbon source. Our results indicate that a decline in law enforcement led to increases in deforestation, biomass burning and forest degradation, which increased carbon emissions and enhanced drying and warming of the Amazon forests.
CO2 emissions in the Amazon
2023 - TEJADA, GRACIELA; GATTI, LUCIANA V.; BASSO, LUANA S.; CASSOL, HENRIQUE L.G.; SILVA-JUNIOR, CELSO H.L.; MATAVELI, GUILHERME; MARANI, LUCIANO; ARAI, EGIDIO; GLOOR, MANUEL; MILLER, JHON B.; CUNHA, CAMILA L.; DOMINGUES, LUCAS G.; IPIA, ALBER; CORREIA, CAIO S.C.; CRISPIM, STEPHANE P.; NEVES, RAIANE A.L.; RANDOW, CELSO V.
Amazon forests are the largest forests in the tropics and play a fundamental role for regional and global ecosystem service provision. However, they are under threat primarily from deforestation. Amazonia's carbon balance trend reflects the condition of its forests. There are different approaches to estimate large-scale carbon balances, including top-down (e.g., CO2 atmospheric measurements combined with atmospheric transport information) and bottom-up (e.g., land use and cover change (LUCC) data based on remote sensing methods). It is important to understand their similarities and differences. Here we provide bottom-up LUCC estimates and determine to what extent they are consistent with recent top-down flux estimates during 2010 to 2018 for the Brazilian Amazon. We combine LUCC datasets resulting in annual LUCC maps from 2010 to 2018 with emissions and removals for each LUCC, and compare the resulting CO2 estimates with top-down estimates based on atmospheric measurements. We take into account forest carbon stock maps for estimating loss processes, and carbon uptake of regenerating and mature forests. In the bottom-up approach total CO2 emissions (2010 to 2018), deforestation and degradation are the largest contributing processes accounting for 58% (4.3 PgCO2) and 37% (2.7 PgCO2) respectively. Looking at the total carbon uptake, primary forests play a dominant role accounting for 79% (−5.9 PgCO2) and secondary forest growth for 17% (−1.2 PgCO2). Overall, according to our bottom-up estimates the Brazilian Amazon is a carbon sink until 2014 and a source from 2015 to 2018. In contrast according to the top-down approach the Brazilian Amazon is a source during the entire period. Both approaches estimate largest emissions in 2016. During the period where flux signs are the same (2015–2018) top-down estimates are approximately 3 times larger in 2015–2016 than bottom-up estimates while in 2017–2018 there is closer agreement. There is some agreement between the approaches–notably that the Brazilian Amazon has been a source during 2015–2018 however there are also disagreements. Generally, emissions estimated by the bottom-up approach tend to be lower. Understanding the differences will help improve both approaches and our understanding of the Amazon carbon cycle under human pressure and climate change.
Sixteen years of MOPITT satellite data strongly constrain Amazon CO fire emissions
2022 - NAUS, STIJN; DOMINGUES, LUCAS G.; KROL, MAARTEN; LUIJKX, INGRID T.; GATTI, LUCIANA V.; MILLER, JOHN B.; GLOOR, EMANUEL; BASU, SOURISH; CORREIA, CAIO; KOREN, GERBRAND; WORDEN, HELEN M.; FLEMMING, JOHANNES; PETRON, GABRIELLE; PETERS, WOUTER
Despite the consensus on the overall downward trend in Amazon forest loss in the previous decade, estimates of yearly carbon emissions from deforestation still vary widely. Estimated carbon emissions are currently often based on data from local logging activity reports, changes in remotely sensed biomass, and remote detection of fire hotspots and burned area. Here, we use 16 years of satellite-derived carbon monoxide (CO) columns to constrain fire CO emissions from the Amazon Basin between 2003 and 2018. Through data assimilation, we produce 3 d average maps of fire CO emissions over the Amazon, which we verified to be consistent with a long-term monitoring programme of aircraft CO profiles over five sites in the Amazon. Our new product independently confirms a long-term decrease of 54% in deforestation-related CO emissions over the study period. Interannual variability is large, with known anomalously dry years showing a more than 4-fold increase in basin-wide fire emissions relative to wet years. At the level of individual Brazilian states, we find that both soil moisture anomalies and human ignitions determine fire activity, suggesting that future carbon release from fires depends on drought intensity as much as on continued forest protection. Our study shows that the atmospheric composition perspective on deforestation is a valuable additional monitoring instrument that complements existing bottom-up and remote sensing methods for land-use change. Extension of such a perspective to an operational framework is timely considering the observed increased fire intensity in the Amazon Basin between 2019 and 2021.
Regional variability in Amazon methane emissions based on lower-troposphere observations
2022 - BASSO, LUANA; GATTI, LUCIANA; MARANI, LUCIANO; MILLER, JOHN; GLOOR, MANUEL; MELACK, JOHN; CASSOL, HENRIQUE; TEJADA, GRACIELA; DOMINGUES, LUCAS; ARAI, EGIDIO; SANCHEZ, ALBER; CORREA, SERGIO; ANDERSON, LIANA; ARAGAO, LUIZ; CORREIA, CAIO; CRISPIM, STEPHANIE; NEVES, RAIANE
After a period where atmospheric methane (CH4) levels were nearly steady, its levels have been rapidly raising since 2007, but the main reasons remains uncertain. Increases in wetlands emissions could be one possible reason, mainly at tropical regions like Amazonia, which host some of the largest wetlands/seasonally flooded areas on the globe. Based on 590 lower troposphere vertical profiles of CH4 and carbon monoxide (CO) observations over four sites at Amazon (at the northeast, southeast, northwest-central and southwest-central regions) we estimated that Amazon region contributes with 8% of global CH4 emissions, and wetlands are the mainly CH4 source to the atmosphere (Basso et al., 2021). Vertical profiles are sampled using light aircraft, high-precision greenhouse gas and CO analysis of flask air, fortnightly between 2010 and 2018. We observed an unexpected east-west gradient in CH4 emissions, with higher emissions in northeast Amazon region. The higher emissions are mainly from wetlands and are not explained by biomass burning and anthropogenic emissions (like enteric fermentation), but its causes remains unclear. In the other three sites located further downwind along the main air-stream the CH4 emissions represents approximately 24-36% of what is observed in the northeast region. Our wetlands emission estimates of each region were compared to analogous fluxes from the WetCharts wetland model ensemble (Bloom et al., 2017). The estimates were similar except for the northeast region, where WetCharts does show substantial emissions, but still just 40% of our estimates based on the lower troposphere observations (Basso et al., 2021).
Amazon methane budget derived from multi-year airborne observations highlights regional variations in emissions
2021 - BASSO, LUANA S.; MARANI, LUCIANO; GATTI, LUCIANA V.; MILLER, JOHN B.; GLOOR, MANUEL; MELACK, JOHN; CASSOL, HENRIQUE L.G.; TEJADA, GRACIELA; DOMINGUES, LUCAS G.; ARAI, EGIDIO; SANCHEZ, ALBER H.; CORREA, SERGIO M.; ANDERSON, LIANA; ARAGAO, LUIZ E.O.C.; CORREIA, CAIO S.C.; CRISPIM, STEPHANE P.; NEVES, RAIANE A.L.
Atmospheric methane concentrations were nearly constant between 1999 and 2006, but have been rising since by an average of ~8 ppb per year. Increases in wetland emissions, the largest natural global methane source, may be partly responsible for this rise. The scarcity of in situ atmospheric methane observations in tropical regions may be one source of large disparities between top-down and bottom-up estimates. Here we present 590 lower-troposphere vertical profiles of methane concentration from four sites across Amazonia between 2010 and 2018. We find that Amazonia emits 46.2 ± 10.3 Tg of methane per year (~8% of global emissions) with no temporal trend. Based on carbon monoxide, 17% of the sources are from biomass burning with the remainder (83%) attributable mainly to wetlands. Northwest-central Amazon emissions are nearly aseasonal, consistent with weak precipitation seasonality, while southern emissions are strongly seasonal linked to soil water seasonality. We also find a distinct east-west contrast with large fluxes in the northeast, the cause of which is currently unclear.
Amazonia as a carbon source linked to deforestation and climate change
2021 - GATTI, LUCIANA V.; BASSO, LUANA S.; MILLER, JOHN B.; GLOOR, MANUEL; DOMINGUES, LUCAS G.; CASSOL, HENRIQUE L.G.; TEJADA, GRACIELA; ARAGAO, LUIZ E.O.C.; NOBRE, CARLOS; PETERS, WOUTER; MARANI, LUCIANO; ARAI, EGIDIO; SANCHES, ALBER H.; CORREA, SERGIO M.; ANDERSON, LIANA; VON RANDOW, CELSO; CORREIA, CAIO S.C.; CRISPIM, STEPHANE P.; NEVES, RAIANE A.L.
Amazonia hosts the Earth’s largest tropical forests and has been shown to be an important carbon sink over recent decades. This carbon sink seems to be in decline, however, as a result of factors such as deforestation and climate change. Here we investigate Amazonia’s carbon budget and the main drivers responsible for its change into a carbon source. We performed 590 aircraft vertical profiling measurements of lower-tropospheric concentrations of carbon dioxide and carbon monoxide at four sites in Amazonia from 2010 to 2018. We find that total carbon emissions are greater in eastern Amazonia than in the western part, mostly as a result of spatial differences in carbon-monoxide-derived fire emissions. Southeastern Amazonia, in particular, acts as a net carbon source (total carbon flux minus fire emissions) to the atmosphere. Over the past 40 years, eastern Amazonia has been subjected to more deforestation, warming and moisture stress than the western part, especially during the dry season, with the southeast experiencing the strongest trends. We explore the effect of climate change and deforestation trends on carbon emissions at our study sites, and find that the intensification of the dry season and an increase in deforestation seem to promote ecosystem stress, increase in fire occurrence, and higher carbon emissions in the eastern Amazon. This is in line with recent studies that indicate an increase in tree mortality and a reduction in photosynthesis as a result of climatic changes across Amazonia.
Determinação da altura da camada limite planetária utilizando perfis verticais de temperatura potencial, umidade específica e de CO2 coletados na Amazônia
2020 - RIBEIRO, MAISA M.; GATTI, LUCIANA V.; BASSO, LUANA S.; FISCH, GILBERTO; DOMINGUES, LUCAS G.; CORREIA, CAIO S.C.; MARANI, LUCIANO; NEVES, RAIANE A.L.; CRISPIM, STEPHANE P.
Este estudo teve o objetivo de determinar a altura da camada limite planetária (Camada Limite Convectiva - CLC), utilizando os perfis verticais de temperatura potencial, umidade específica e gás carbônico, realizados entre 12 e 13 horas (horário local). As coletas são realizadas utilizando avião de pequeno porte no Projeto CARBAM, em 4 localidades da Amazônia: ALF (Alta Floresta – MT, 8,8S, 56,8O), RBA (Rio Branco – AC, 9,0S, 64,4O), SAN (Santarém – PA, 2,8S, 54,9O) e TEF (Tefé – AM, 3,4S, 65,6O). Estas alturas foram determinadas nas estações chuvosa e seca nas 4 localidades de estudo, no período de 2010 a 2017 (8 anos). O conjunto de dados obtidos foi em torno de 300 perfis verticais de temperatura potencial e umidade específica e de perfis de CO2. Observou-se uma CLC mais alta durante a estação seca e também nas localidades com maiores proporções de mudanças de uso da terra. Os locais que apresentaram uma maior quantidade de corpos d’água em superfície apresentaram as menores diferenças entre as alturas da CLC nas estações chuvosa e seca. Notou-se também que as localidades mais ao sul (ALF) apresentaram uma sazonalidade maior.
Measuring stables isotopes of CO2 (13C and 17,18O) in vertical profiles over the Amazon
2020 - NEVES, R.A.L.; GATTI, L.V.; BASSO, L.S.; MARANI, L.; CRISPIM, S.P.; CORREIA, C.S.C.; DOMINGUES, L.G.; PAUL, D.; SCHEEREN, B.; ADNEW, G.; ROCKMANN, T.; PETERS, W.
Background concentrations of CO2, CO and N2O in Brazilian coast
2020 - MARANI, L.; BORGES, V.F.; GATTI, L.V.; DOMINGUES, L.G.; CORREIA, C.S.C.; BASSO, L.S.; SANTOS, R.S. dos; CRISPIM, S.P.; NEVES, R.A.L.; GLOOR, M.; MILLER, J.B.