Emissions of Biogenic Volatile Organic Compounds (BVOCs) in the Amazon, their impacts on the ecosystem, and the formation of secondary organic aerosols.

• Grant number: 25/07647-7
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: July 01, 2025
• End date: June 30, 2027
• Field of knowledge: Physical Sciences and Mathematics - Geosciences
• Principal Investigator: Paulo Eduardo Artaxo Netto
• Grantee: Débora Pinheiro de Oliveira
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 23/04358-9 - Trace gases-aerosols-cloud interactions in Amazonia: from bioaerosols emissions to large-scale impacts (GAIA), AP.TEM

Abstract

The atmosphere of the Amazon rainforest has a strong interaction with the biological functioning of the ecosystem, and one of the main components of this interaction is the emission of biogenic volatile organic compounds (BVOCs). Secondary organic aerosols (SOA) produced by the emission of isoprene, terpenes, and other BVOCs affect the radiation balance and cloud formation through their role as Cloud Condensation Nuclei (CCN). The dynamics of this process are complex and still poorly understood. Changes in land use, emissions from forest fires, and climate change influence these natural cycles, altering the emission and absorption of greenhouse gases (GHGs). This research project will investigate processes that affect the fluxes of BVOCs in different regions of the Amazon and the processes that lead to the production of SOA and CCNs. To this end, we will carry out unprecedented measurements at the ATTO-Campina experimental site and in other regions of the Amazon basin. We will perform measurements from aircraft to determine the vertical profile of the BVOC distribution over the ATTO tower and the ATTO-Campina site and measurements from boats in the Amazon River system, analyzing the large-scale spatial distribution in the Amazon basin. BVOC measurements will be performed using Proton Reaction Mass Spectrometry (PTR-MS) techniques and gas chromatography. The physicochemical properties of aerosols will be determined by aerosol mass spectrometry (AMS), and the size distribution will be determined using a Scanning Mobility Particle Spectrometer (SMPS). The relationship between the different BVOCs measured and the production of nanoparticles will be studied, and their growth will be analyzed until they reach sizes where they can act as CCNs. Unprecedented measurements in several Amazon rivers will determine the spatial distribution of these concentrations in the river systems. The results may shed light on the processes that are not yet understood between BVOC emissions and SOA production, which consist of nanoparticles that, after growth, may impact on the atmospheric radiative balance and cloud production mechanisms.