Amazon CH4 budget and its controls based on atmospheric data from vertical profiles measurements
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2020
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EGU General Assembly
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Wetland 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.
Como referenciar
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, MANUEL. Amazon CH4 budget and its controls based on atmospheric data from vertical profiles measurements. In: EGU General Assembly, May 4-8, 2020, Online. Abstract... Göttingen, Germany: Copernicus, 2020. Disponível em: http://200.136.52.105/handle/123456789/31676. Acesso em: 13 Mar 2025.
Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.