Major Regional-Scale Production of O-3 and Secondary Organic Aerosol in Remote Amazon Regions from the Dynamics and Photochemistry of Urban and Forest Emissions

Author(s):Show less -

Nascimento, Janaina P. ; Barbosa, Henrique M. J. ; Banducci, Alessandro L. ; Rizzo, Luciana V. ; Vara-Vela, Angel Liduvino ; Meller, Bruno B. ; Gomes, Helber ; Cezar, Andre ; Franco, Marco A. ; Ponczek, Milena ; Wolff, Stefan ; Bela, Megan M. ; Artaxo, Paulo

• Document type: Journal article
• Source: Environmental Science & Technology; v. 56, n. 14, p. 12-pg., 2022-07-08.

Abstract

The Amazon rainforest suffers increasing pressure from anthropogenic activities. A key aspect not fully understood is how anthropogenic atmospheric emissions within the basin interact with biogenic emissions and impact the forest's atmosphere and biosphere. We combine a high-resolution atmospheric chemical transport model with an improved emissions inventory and in-situ measurements to investigate a surprisingly high concentration of ozone (O3) and secondary organic aerosol (SOA) 150-200 km downwind of Manaus city in an otherwise pristine forested region. We show that atmospheric dynamics and photochemistry determine a gross production of secondary pollutants seen in the simulation. After sunrise, the erosion of the nocturnal boundary layer mixes natural forest emissions, rich in biogenic volatile organic compounds, with a lofted pollution layer transported overnight, rich in nitrogen oxides and formaldehyde. As a result, O3 and SOA concentrations greater than similar to 47 ppbv and 1.8 mu g m-3, respectively, were found, with maximum concentrations occurring at 2 pm LT, 150-200 km downwind of Manaus city. These high concentrations affect a large primary forested area of about 11,250 km2. These oxidative areas are under a NOx-limited regime so that changes in NOx emissions from Manaus have a significant impact on O3 and SOA production. (AU)

• FAPESP's process: 13/50510-5 - Brazil-USA collaborative research: modifications by anthropogenic pollution of the natural atmospheric chemistry and particle microphysics of the tropical rain forest during GoAmazon intensive operating periods
• Grantee: Henrique de Melo Jorge Barbosa
• Support Opportunities: Research Program on Global Climate Change - Regular Grants
• FAPESP's process: 13/10156-8 - Vertical profiles of O3 and SO2 in a preserved forest site in Amazonia
• Grantee: Luciana Varanda Rizzo
• Support Opportunities: Regular Research Grants
• FAPESP's process: 17/17047-0 - Aerosol and clouds life cycles in Amazonia: biogenic emissions, biomass burning and impacts on ecosystem
• Grantee: Paulo Eduardo Artaxo Netto
• Support Opportunities: Research Program on Global Climate Change - Thematic Grants
• FAPESP's process: 13/05014-0 - GoAmazon: interactions of the urban plume of Manaus with biogenic forest emissions in Amazonia
• Grantee: Paulo Eduardo Artaxo Netto
• Support Opportunities: Research Program on Global Climate Change - Thematic Grants