Trace gases-aerosols-cloud interactions in Amazonia: from bioaerosols emissions to large-scale impacts (GAIA)

Abstract

The Amazon is a living laboratory for studying critical processes that regulate the chemistry and physics of the tropical atmosphere and influence regional and global climate. Long-term observations and process studies are essential to uncover possible degradation mechanisms in the Amazon Forest. We plan to advance science on critically important processes that influence the hydrologic cycle, radiation balance, reactive and greenhouse gas exchange, bioaerosols, and the functioning of the Amazonian ecosystem. This will be done through a combination of 7 components in this proposal: 1) Improvements in the long-term continuous measurements of the ATTO tower, with the addition of new studies of aerosols and trace gases, with the use of the newly installed automatic elevator (system RoLi) that will allow continuous day and night vertical profiles from the ground up to 325 meters. We will also measure nanoparticles in the range of 2 to 10 nanometers and study how they grow to form secondary organic aerosols (SOA) and later cloud condensation nuclei (CCN); 2) Improvements in studies of cloud-aerosol interactions with new measurements on the ATTO Campina site, with vertical soil profiles up to 16 km altitude, with profiling instruments such as Lidar de aerosols, cloud radar, precipitation radar, radiometers and the scanning weather radar being installed in Balbina. The cloud-aerosol-trace gas interactions over the vertical column will be studied in this component; 3) Extend ATTO tower measurements to the entire Amazon basin on a large scale through extensive ship cruises along the Solimões, Negro, and Amazon rivers, using the UEA ship as a river platform. These measurements focus on the distribution and interactions of VOCs, aerosols, greenhouse gases, and biological particles; 4) Carry out data analysis from the CAFE-Brazil experiment with measurements up to 14 Km of altitude throughout the Amazon, and we will use small aircraft to carry out vertical profiles of aerosols, greenhouse gases, biological particles and other measurements up to 5 Km; 5) Carry out detailed measurements of primary biological aerosol particles throughout the basin, with particle fluorescence detection, enabling the speciation of bacteria, fungal spores, plant fragments and other types of bioaerosols. In this component, we will perform metagenomic analyzes of DNA in aerosol particles to identify species transported atmospherically over long distances from Africa to the Amazon and within the Amazon; 6) Integrate large-scale measurements of greenhouse gases such as CO2 and CH4, including isotopic determination, through cruises on several rivers and sampling at LBA towers along the Amazon; 7) Implement an integrated modeling component to help understand processes and to generalize properties across the basin from fixed point measurements and vessel campaigns, in addition to remote sensing measurements. With these innovative measurements, more complete datasets, and associated modeling efforts, we plan to unravel the complex gas-trace-cloud-aerosol-precipitation interactions. We will also study the feedback between the biosphere and the atmosphere with anthropogenic activities through the impacts of deforestation and emissions from fires. These integrated activities will provide new insights into critical processes that regulate tropical atmospheric chemistry, cloud physics, climate over tropical forests, and the integrated functioning of the Amazonian ecosystem. (AU)