LUCAS GATTI DOMINGUES

LUCAS GATTI DOMINGUES

Página do item completo

Resultados de Busca

Agora exibindo 1 - 10 de 33

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.
Measurement program of GHG vertical profiles at Amazon
2020 - GATTI, L.V.; MILLER, J.B.; GLOOR, M.; DOMINGUES, L.G.; CORREIA, C.S.C.; BASSO, L.; MARANI, L.; CASSOL, H.L.G.; TEJADA, G.; BORGES, V.F.; PETERS, W.; CRISPIM, S.P.; LOPES, R.; RIBEIRO, M.M.; MORAIS, C.S.; AQUINO, C.A.B.
Study of long term SF6 mole fractions in Amazon and Brazilian coast
2020 - BASSO, L.S.; SANTOS, R.S.; BORGES, V.F.; GATTI, L.V.; DOMINGUES, L.G.; CORREIA, C.S.C.; MARANI, L.; CRISPIM, S.P.; NEVES, R.A.L.; GLOOR, M.; MILLER, J.B.
Long term CH4 measurements in Amazon and Brazilian coast
2020 - BASSO, L.S.; BORGES, V.F.; GATTI, L.V.; MARANI, L.; MORAIS, C.S.; CORREIA, C.S.C.; DOMINGUES, L.G.; NEVES, R.A.L.; CRISPIM, S.P.; GLOOR, M.; MILLER, J.B.
Invited Keynote: Inter-annual variation of Amazon greenhouse balances 2010- 2014
2017 - GATTI, LUCIANA V.; GLOOR, MANUEL; MILLER, JOHN B.; DOMINGUES, LUCAS G.; SILVA, MARCELO G.; ARAGAO, LUIZ E.O.C.; MARANI, LUCIANO; CORREIA, CAIO C.S.; PETERS, WOUTER; BORGES, VIVIANE F.; IPIA, ALBER H.S.; BASSO, LUANA S.; ANDERSON, LIANA O.; ALDEN, CAROLINE B.; VAN DER LAAN-LUIJKX, INGRID; BARICHIVICH, JONATHAN; SANTOS, RICARDO S.; CRISPIM, STEPHANE P.; COSTA, WELLISSON R.; ROSAN, THAIS M.
Net carbon exchange between tropical land and the atmosphere is potentially important because the vast amounts of carbon in forests and soils can be released on short time-scales e.g. via deforestation or changes in temperature and moisture. Such changes may thus cause feedbacks on global climate, as have been predicted in earth system models. In the tropics, the Amazon is most significant in the global carbon cycle, hosting by far the largest carbon vegetation and soil carbon pools (~200 PgC). Because of the very large precipitation amounts, approximately 20-25% of its area is seasonally flooded and thus it is also an important region for methane emissions. From 2010 onwards we have extended an earlier greenhouse gas measurement program to include regular vertical profiles of CO2, CH4, N2O, CO, SF6, from the ground up to 4.5 km height at four sites along the main air-stream over the Amazon Basin. Our measurements demonstrate that surface flux signals are primarily concentrated to the lower 2 km and thus vertical profile measurements are ideally suited to estimate greenhouse gas balances. Clearly a higher measurement density is desirable. We are in the process of expanding the number of surface and airborne sampling sites as well as the number of trace gases measured. Nonetheless, because of the homogeneity of the vegetation (forests) and the coherent east to west trade-winds over the Basin, these data already permit a range of insights about the magnitude, seasonality, inter-annual variation of carbon fluxes and their controls. Most recent years have been anomalously hot with the southern part of the Basin having warmed the most. Precipitation regimes also seem to have shifted with an increase in extreme floods. Approximately 20 percent of Amazon forests have been deforested by now and development pressure on forests continues. For the specific period we will discuss the year 2010 was anomalously dry, followed by 4 years wet (2011, 2012, 2013 and 2014) and another dry year (2015/16 -El Nino year). This period provides an interesting contrast of climatic conditions in a warming world with increasing human pressures. We will analyze the effect of this climate variability on annual and seasonal carbon balances for these five years using our atmospheric data. We will estimate fluxes using a simple, but powerful back-trajectory based atmospheric mass balance approach. Our data permit us not only to estimate net CO2 and CH4 fluxes, but using carbon monoxide we estimate carbon release via fires and thus the net carbon balance of the unburned land vegetation. We will relate fire emissions to controls of land vegetation functioning and independent diagnostics like fire counts. We will also discuss what our results suggest for the role of the tropics of the global carbon balance.
Amazon Basin biomass burning emission and its correlation with climatology and deforestation
2017 - DOMINGUES, LUCAS G.; GATTI, LUCIANA V.; GLOOR, MANUEL; MILLER, JOHN B.; AQUINO, AFONSO R.; ARAGAO, LUIZ E.O. e C.; ANDERSON, LIANA O.; MARANI, LUCIANO; CORREIA, CAIO S. de C.; SILVA, MARCELO G.; BORGES, VIVIANE F.; IPIA, ALBER H.S.; BASSO, LUANA S.; SANTOS, RICARDO S.; CRISPIM, STEPHANI P.; COSTA, WELLISON R.
Tropical rainforests have great potential to affect the global carbon budget considering their large quantities of labile carbon stored in forests and soils. Among the tropical regions, the Amazon forest covers the largest area and also hosts the largest carbon pool (~200 PgC), corresponding for 50% of its biome globally. It has a total area of approximately 6.7 million km2, of which, 4.2 million km2 is in Brazil, which corresponds to approximately 60 % of Amazon territory, and contains one quarter of global biodiversity. Over recent years, the Amazon Basin hydrological cycle has changed considerably which presented severe droughts in 2005, 2010 and 2015. 2015 is likely the largest drought over the past 15 years. Droughts in the Amazon are intrinsically correlated to extensive wildfires. At 2004/2005 the number of fire hot spots reached its maximum, coincident with the peak in deforestation. However, in the recent years, despite the decrease in deforestation rates, increase in fire hot spots have been observed, particularly during the years of extreme drought, 2010 and 2015. 2011 had the fewest number of fire hot spots, but since 2013 a positive trend was identified, reaching the maximum peak in 2015. Although deforestation estimation has decreased strongly over the last decade (71% reduction from 2004 to 2012), estimates of fire related carbon fluxes to the atmosphere estimated using regular atmospheric carbon monoxide concentration measurements indicate that there may be a discrepancy. These data do suggest a much smaller decrease, which lead us to believe that deforestation, as observed from satellite, is not the only process causing release of carbon by fires. Thus, understanding the relation between carbon emissions from biomass burning and climate, fire hot spots based on remote sensing and deforestation is important as it may reveal biases in remote sensing based estimates of deforestation. In turn it may help to evaluate the effectiveness of actions to preserve the forests. To elucidate the actual contribution and the carbon emission from biomass burning in the Amazon Basin, measurements of carbon monoxide are an important tool. We will report the results from a recently established pan Amazon lower troposphere biweekly to monthly atmospheric sampling program for the years 2010 to 2014. Amazon Basin biomass burning carbon emissions have been determined by applying a mass balance technique to carbon monoxide measured from vertical profiles in four sites over the Amazon Basin. We will present these results from biomass burning and compare the carbon monoxide emissions with those from carbon dioxide, resulting in a ratio of carbon biomass burning emission which we will analyze with respect to climate, deforestation and number of fire hot spots.
Amazon Atlantic outflow region carbon cycling constrained by atmospheric greenhouse gas data
2017 - BORGES, VIVIANE F.; GATTI, LUCIANA V.; GLOOR, EMANUEL U.; MILLER, JOHN B.; BOESCH, HARTMUT; DOMINGUES, LUCAS G.; CORREIA, CAIO S. de C.; BASSO, LUANA S.; SANTOS, RICARDO S.
Estuaries and near-coastal regions may process substantial amounts of carbon causing a nonnegligible carbon uptake from the atmosphere. For purpose of characterizing the greenhouse gas levels of air entering the Amazon basin from the Atlantic we have been measuring regularly greenhouse gas concentrations at several sites along the North-East Atlantic coast of Brazil over approximately the past six years (at some of the sites for much longer). At some of the sites sampling is restricted close to the surface while at other sites we have been measuring vertical profiles. At Salinopolis which is located close to the Amazon outflow region to the Atlantic seasonally strong CO2 depletion in both surface records and aircraft vertical profiles compared to background sites like Ascension Island is clearly discernible. The seasonality is synchronous with increases in chlorophyll observed from space e.g. by the SeaWiFS mission. Incidentally during the CO2 depletion period airmass trajectories tend to pass over the shelf region along the Brazilian coast travelling from the South along the coast. This enables us to apply an air column mass balance approach to estimate the magnitude of the CO2 flux into the sea along the coast during the blooms. Using the chlorophyll maps we may furthermore extrapolate the flux estimates spatially to obtain an area integrated flux. We will discuss our findings and put our flux estimates into perspective with estimates for productivity and carbon uptake in coastal regions of major tropical rivers as well as the extra-tropics. Acknowledgment: CNPq, NERC, FAPESP, MCTI, NOAA, IPEN and INPE.
Greenhouse gases
2017 - BORGES, V.F.; GATTI, L.V.; DOMINGUES, L.G.; CORREIA, C.S.C.; BASSO, L.S.; SANTOS, R.S.; COSTA, W.R.; CRISPIM, S.P.; MARANI, L.; PENHA, T.L.B.; PAULA, A.L.S.; GLOOR, E.U.; MILLER, J.B.; KOFLER, J.
In Tropical areas, and specifically in the Atlantic Ocean, there are not enough measures on greenhouse gases (GHG), and Amazon Basin represent around 50% of the world's rainforest [1]. Understand the characteristic GHG concentrations in Tropical Global range on Atlantic Ocean is an important task for many studies to determine GHG balances. The motivation of this study was understanding better the typical background for Amazon Basin from the air masses that arrived on North and Northeast Brazilian coast, come from the Atlantic Ocean in the period 2006 to 2016. We started to collect air samples on the Brazilian coast: Arembepe/BA (ABP: 12º45’46.79”S; 38º10’08.39”W – from 2006 to 2010, 15 meters above sea-level), Salinopolis/PA (SAL: 00º36’15.03”S; 47º22’25.02”W – from 2010 to 2017, 10 m a.s.l.), Natal/RN (NAT: 05º29’22.05”S; 35º15’39.64”W 15 m a.s.l – since 2010 to December 2015, then the site moved to 05º47’42.77”S; 35º11’07.10”W, 87 m a.s.l.), Camocim/CE (CAM: 02º51’47.00”S; 40º51’36.70”W – since 2014, 21.5 m a.s.l.), and in December 2016 it was started a special place at Itarema/CE (ITA: 02º55’57.11”S; 39º50’38.49”W, 96.5 m a.s.l.), where the inlet was installed in the top of a 100 m tower in the beach. In each site, the air samples, with variable height were collected weekly by using a pair of glass flasks (2.5L) and a portable sampler. The air samples were analysed on the Greenhouse Gas Laboratory (LaGEE) at IPEN (until April 2015) and later at INPE/CCST. It was quantified the respective gases: carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), sulphur hexafluoride (SF6) and carbon monoxide (CO). Results showed that each site presents seasonality when compared to Ascension Island (ASC: 07º96'67.00"S; 14º0'00.00"W, South Atlantic Ocean) and Ragged Point Barbados (RPB: 13º16'50.00"N, 59º43'20.00"W, North Atlantic Ocean) global stations. Simulations of backward trajectories by HYSPLIT model (using 240 hours) [2], allowed observing how each study site is influenced by global circulation and process like Intertropical Convergence Zone [3]. Between Jan-May, the ITCZ is below SAL and CAM latitude, influencing the air masses that arrived at sites in this period. At SAL and CAM the air masses came from both North and South Atlantic Ocean, depending on time of the year, and at NAT and ABP the air masses came from only South Atlantic Ocean. The GHG concentrations showed seasonality and sometimes periods with high concentrations. Overall, all Brazilian coast sites, showed the same increase on the GHG concentrations than global mean.
Long term nitrous oxide measurements over amazon basin using small aircraft
2017 - CORREIA, C.S.C.; GATTI, L.V.; DOMINGUES, L.G.; SANTOS, R.S.; COSTA, W.R.; CRISPIM, S.P.; BORGES, V.F.; MARANI, L.; GLOOR, E.U.; MILLER, J.B.
The Nitrous Oxide (N2O) is the third most important natural greenhouse gas on Earth (WMO, 2016). Globally, the main sources are nitrification and denitrification promoted by microorganisms and it can be natural (~60%) or anthropogenic (~40%) (IPCC, 2007). Approximately two thirds of soil emissions are provided from tropical areas and ~20% of this are from rainforests ecosystems as the region we have studied (Van Haren et al., 2005; Melillo et al. 2001). In Brazil 87% of N2O anthropogenic emissions are from agricultural activities. In this study, natural air was sampled in glass flasks using small aircraft over four sites in the brazilian Amazon Basin in order to have a great quadrant to better understand the whole area: Alta Floresta (ALF; 8.80ºS, 56.75ºW), Rio Branco (RBA; 9.38ºS, 67.62ºW), Santarém (SAN; 2.86ºS, 54.95ºW) and Tabatinga (TAB; 5.96ºS, 70.06ºW), ALF, RBA and TAB sites started in 2010 and we still perform sampling in these sites, the last one changed to Tefé (TEF; 3.39°S, 65.6°W) in 2013 due to technical problems. The measurements in SAN started in 2000 and the quantification was done by NOAA until 2003, after this year the analysis started to being done by our laboratory. The mixing ratios in all the studied stations have presented an increase along the years, varying from ~316ppm in 2000 in to ~330ppm in the present days, i.e. a mean growth rate of ~0.82ppm yr-1, which is consistent with global data where the growth rate for the past 10 years is around 0.89 ppm yr-1(WMO, 2016).
Amazon basin and brazilian coast SF6 study in a 15 years time series
2017 - SANTOS, R.S.; GATTI, L.V.; DOMINGUES, L.G.; CORREIA, C.S.C.; AQUINO, A.R.; BASSO, L.S.; BORGES, V.F.; COSTA, W.R.; CRISPIM, S.P.; MARANI, L.; GLOOR, E.U.; MILLER, J.B.; PETERS, W.
The sulphur hexafluoride (SF6) is known as a potent Long Lived Greenhouse Gases and it is a synthetic gas with a millennia lifetime, about 3200 years, and has a Global Warm Potential 23000 time higher than the Carbon Dioxide (CO2). Levin et al. (2010)1 showed that SF6 emissions decreased after 1995, most likely because of emissions reductions in developed countries, but then increased after 1998. It is produced by the chemical industry, mainly as an electrical insulator in power distribution equipment2. Due its very long lifetime, SF6 emissions are accumulating in the atmosphere. Its global mole fraction increased nearly linearly in recent decades and in 2014 is about twice the level observed in the mid-1990s3. Its concentration was 4.2 parts per trillion (ppt) in 1998 (TAR) and has continued to increase linearly over the past decade, implying that emissions are approximately constant. Because of these characteristics, the SF6 has been as an essentially inert tracer to study atmospheric and oceanic transport processes3. The Amazon Basin is an ecosystem that has a growing interest by researchers around the world because of its role at the Climate Change. The emissions of SF6 in the Amazon Basin are considered non existents and, a time series of 15 years has the potential to show the behaviour of this gas in a large area. Until now, our mainly interest in SF6 concentrations is to use this gas as a transport tracer to calculate the BKG to Amazon and determinate the CO2, CH4 and N2O fluxes over the Amazon Basin. SF6 atmospheric measurements were started with vertical profiles using small aircrafts, since 2000 in Santarém (SAN; 2.86ºS; 54.95ºW), 2009 in Rio Branco (RBA; 9.38ºS, 67.62ºW), 2010 in Alta Floresta (ALF; 8.80ºS, 56.75ºW)and Tabatinga (TAB; 5.96ºS, 70.06ºW), all these sites located in Brazilian Amazon Basin. Since 2010, we started flasks measurements at two sites located at the Brazilian Atlantic coast: in Salinópolis (SAL; 0.60°S, 47.37°W) and in Natal (NAT; 5.48°S, 35.26°W) and later in 2014 at Camocim (CAM; 2.86°S, 40.08°W) and in 2016 at Itarema in a 100m tower (ITA; 2.93°S, 39.84°W). This work will present analyse of 15 years SF6 measurements at the Amazon Basin and Brazilian coast show the trends, comparing the years and the behaviour among the sites regions which is expect to change mainly by the differences of the air masses origin.