ERICA at ATTO
Sources and processes controlling the formation and composition of sub-micron aerosol in the Amazon rainforest in the wet season - March/April 2026
This project aims to investigate the sources and processes that govern the formation and composition of sub-micron aerosols in the Amazon rainforest during the wet season. The Amazon, often referred to as the "Earth's green lung," displays a near-pristine atmospheric state during the wet season, with low aerosol mass concentrations and a dominance of biogenic organic compounds. Despite this, occasional long-range transport of air masses can introduce sea spray, mineral dust, and biomass burning emissions from Africa and the Atlantic, adding complexity to the aerosol composition.
The research will be conducted in-situ at the Amazon Tall Tower Observatory (ATTO), located approximately 150 km northeast of Manaus, Brazil. During an intensive 8-week measurement phase in March and April 2026, the aerosol mass spectrometer ERICA will be used to provide high temporal resolution measurements of aerosol chemical composition, mixing states, and particle sizes.
The study addresses three key scientific topics:
- We will explore the role of biogenic submicron salts, originating from ground-level fungi and other sources, as nucleation sites for sub-micron particles.
- We will examine the processes controlling the growth of these seeded particles, with a particular focus on the role of low-volatility organosulfates.
- The project will investigate whether ultrafine particles from high-altitude nucleation, potentially driven by isoprene-derived organic nitrates, contribute significantly to the submicron aerosol population in the Amazon boundary layer.
In addition to the wet season, the project plans to continue measurements into the dry season (September/October 2026) to compare different meteorological conditions and aerosol formation processes. The insights gained are expected to improve our understanding of aerosol dynamics in the Amazon, with broader implications for atmospheric chemistry and climate modelling.
ERICA (ERC Instrument for the Chemical composition of Aerosols)
O. Eppers, B. Sebben, S. Molleker, A. Dragoneas, F. Köllner, Y. Cheng
C. Pöhlker, H. Harder, J. Williams, A. Edtbauer (MPIC)
T. Hoffmann, H. Tost (University Mainz)
H. van Asperen (MPI-BG)
P. Artaxo, L. Machado (University Sao Paolo)