Aerosol Dynamics in Amazonian Ecosystems

Aerosols in the Amazonian ecosystem are a complex interplay of natural emissions, meteorological processes and long-range transport. Biogenic volatile organic compounds emitted by the vast forest canopy provide precursors for secondary aerosol formation, while precipitation and deep convective events modulate particle populations through wet scavenging and new particle nucleation. Long-range smoke from Africa and regional biomass burning seasonally alter the chemical and microphysical properties of atmospheric particles, influencing cloud formation, radiative balance and ecosystem nutrient cycles. Upper-tropospheric aerosol dynamics link surface emissions and convective transport, feeding back on climate through cloud condensation nuclei formation and radiative forcing. Understanding these processes is vital for predicting the Amazon’s role in the global climate system and for informing sustainable land-use and environmental policies.

Research from Nature Portfolio

Recent studies reveal that rainfall within the forest canopy can trigger bursts of nanoparticles by reducing the condensation sink and injecting ozone into the foliage, which enhances oxidation of biogenic vapours and generates new particles that serve as cloud condensation nuclei. This paradigm shift underscores the canopy as both a source and reactor for particle formation, altering local cloud microphysics and precipitation patterns. Another investigation quantifies the significant influence of African biomass burning smoke on Amazonian aerosol composition, showing that transcontinental plumes contribute a majority of black carbon during the wet season and markedly affect aerosol-radiation interactions. These findings illuminate the historical role of long-range transported smoke in soil fertilisation, carbon and water cycling, and the resilience of the Amazonian atmosphere under pre-industrial conditions.

Aerosol Dynamics in Amazonian Ecosystems publication trend

The graph below shows the total number of articles in aerosol dynamics in amazonian ecosystems across all publications each year (not limited to Nature Index journals).

Technical terms

Aerosol: Suspension of fine solid or liquid particles in air.

Cloud Condensation Nuclei (CCN): Particles that activate to form cloud droplets under supersaturated conditions.

Biogenic Volatile Organic Compounds (BVOCs): Organic gases emitted by vegetation that can form secondary aerosols.

Nucleation: Initial formation of new particles from gaseous precursors.

Condensation sink: Existing aerosol surface area that removes vapours and suppresses new particle formation.

Primary Biological Aerosol Particles (PBAPs): Airborne particles of biological origin, such as pollen, spores and fragments.

Upper Troposphere (UT): Atmospheric layer roughly between 8 and 15 km altitude, above the boundary layer.

References

1. Frequent rainfall-induced new particle formation within the canopy in the Amazon rainforest. Nature Geoscience (2024).
2. African biomass burning affects aerosol cycling over the Amazon. Communications Earth & Environment (2023).
3. Strong particle production and condensational growth in the upper troposphere sustained by biogenic VOCs from the canopy of the Amazon Basin. Atmospheric Chemistry and Physics (2023).
4. Sink, Source or Something In‐Between? Net Effects of Precipitation on Aerosol Particle Populations. Geophysical Research Letters (2023).
5. Thirty-Five Years of Aerosol–PBAP in situ Research in Brazil: The Need to Think outside the Amazonian Box. Climate (2023).