LUCAS GATTI DOMINGUES
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Resumo IPEN-doc 27448 Amazon CH4 budget and its controls based on atmospheric data from vertical profiles measurements2020 - BASSO, LUANA; GATTI, LUCIANA; MARANI, LUCIANO; CASSOL, HENRIQUE; TEJADA, GRACIELA; DOMINGUES, LUCAS; CORREIA, CAIO; CRISPIM, STEPHANE; NEVES, RAIANE; IPIA, ALBER; ARAI, EGIDIO; ARAGAO, LUIZ; MILLER, JOHN; GLOOR, MANUELWetland emissions are considered the main natural global Methane (CH4) source, but it is budget remains highly uncertain. Tropical regions like the Amazon, host some of the largest wetlands/seasonally flooded areas on the globe. However, tropical regions are still poorly observed with large-scale integrating observations. Here we present the first atmospheric sampling of the lower troposphere over the Amazon using regular vertical profile greenhouse gas and carbon monoxide (CO) observations at four sites. Since 2010 we collected bimonthly CH4, to provide solid seasonal and annual CH4 budgets with large spatial resolution. Vertical profiles are sampled using light aircraft, high-precision greenhouse gas and CO analysis of flask air, fortnightly between 2010 to 2018. The results show a regional variation in CH4 emissions. There are comparably high emissions from the northeast part of the Amazon exhibiting strong variability, with particularly high CH4 fluxes in the beginning of the wet season (January to March). A second period of high emissions occurs during the dry season. The cause of the high emissions is unclear. In the other three sites located further downwind along the main air-stream are observed lower emissions, that represents approximately 25-30% of what is observed in the northeast region and with a clear annual seasonality. In addition, these data show an interannual variability in emissions magnitude, so we discuss how these data can be correlate to climate variables (like temperature and precipitation) and with human-driven changes (like biomass burning) that could be influencing this variability. Over the full period the Amazon (total area of around 7.2 million km2) was a source of CH4, of approximately 46 ± 6 Tg/year, which represent 8% of the global CH4 flux to the atmosphere. Using a CO/CH4 emission ratio calculated in this study we find a biomass burning contribution varying between 10 and 23% of the total flux at each site.Resumo IPEN-doc 27442 Understanding the relationships between local deforestation and CO2 atmospheric measurements in the Brazilian Amazon2019 - TEJADA, GRACIELA; GATTI, LUCIANA; BASSO, LUANA; CASSOL, HENRIQUE L.G.; MARANI, LUCIANO; CORREIA, CAIO; DOMINGUES, LUCAS; CRISPIM, STEPHANE; NEVES, RAIANE; ANDERSON, LIANA O.; ARAGAO, LUIZ E.O.C.; ARAI, EGIDIO; GLOOR, MANUEL; MILLER, JOHN B.; VON RANDOW, CELSOAmazon forests play a fundamental role in the global carbon balance as a carbon sink, but temperature elevations and frequents extreme events as droughts and floods could make the forests a source of CO2. Local atmospheric measurements of greenhouse gases are needed to better understand how forest will respond to climate change. The lower-troposphere greenhouse gas (GHG) monitoring program over Brazilian Amazon Basin, has been collecting biweekly GHGs vertical profiles in four sites since 2010. We aim to understand the relationships between local deforestation and CO2 aircraft measurements in the Brazilian Amazon. We calculated annual deforestation (using the Amazon Deforestation Calculation Program - PRODES), land use and cover change data (using the Brazilian Institute of Geography and Statistics - IBGE) and fire data (using the Fire Monitoring System) in each annual influence area at the four flight measurement sites of the Brazilian Amazon from 2010-2017 (and also in the mean influence area of all years by sites). We found that when we see total deforestation, it has a relationship with global CO2 emissions in the Brazilian Amazon biome. Fire has a strong relationship in the drought years, mostly in 2012. Looking at each site, we found specific correlations with deforestation, fire and land use. The biggest challenge was to compare spatial analyzes of land use change and fire with punctual data of airplane GHGs measurements. This study will contribute in our understanding of anthropogenic activities over the Amazon forest in a changing climate.Resumo IPEN-doc 27441 A first Amazon CH4 budget and its controls based on atmospheric data from vertical profiles measurements2019 - BASSO, LUANA S.; GATTI, LUCIANA V.; MARANI, LUCIANO; CASSOL, HENRIQUE L.G.; TEJADA, GRACIELA; CORREIA, CAIO S.C.; DOMINGUES, LUCAS G.; CRISPIM, STEPHANE P.; NEVES, RAIANE A.L.; ARAI, EGIDIO; MILLER, JOHN B.; GLOOR, MANUEL; ANDERSON, LIANA O.; ARAGAO, LUIZ E.O.C.The role of tropical regions in the global CH4 balance remained uncertain, due these regions have until recently been poorly observed with large-scale integrating in-situ observations. To contribute in understanding the CH4 balance in tropical regions, we have started a lower-troposphere greenhouse gas-monitoring program over Brazilian Amazon Basin consisting of regular vertical profile greenhouse gas observations at four sites. Samples are collected regularly each 2 weeks, using light aircraft. We will present an analysis of these data and what they tell us about the Amazon CH4 cycle and its contribution to global CH4 concentration. We estimate fluxes upwind of the sites from the profile data using a column budgeting approach (Miller et al., 2007). Over the full period (2010-2017) the Amazon Basin was a source of CH4, but with regional variations. There are comparably high and highly variable emissions from the eastern part of the basin exhibiting strong variability, with particularly high CH4 fluxes in two different periods of the year (beginning of the wet season and in the dry season). In contrast to this, a clear seasonality was observed at the other three sites, with the largest emissions occurring at the beginning of the wet season (January to March). Emissions from biomass burning contribute with a small part of the total flux at each site. We will finally discuss what is the influence from precipitation and temperature in the Amazon CH4 emissions.