Study reveals Amazon’s influence on atmospheric particle formation

By Bianca Diniz – From Cenarium

MANAUS (AM) – A groundbreaking study published by Brazilian and international scientists in the scientific journal Nature reveals how the Amazon influences the formation of atmospheric particles and their effects on global climate. Published on December 4, 2024, the research highlights how compounds emitted by tropical forest trees interact in the upper troposphere — the upper layer of the atmosphere where climatic phenomena such as clouds and storms occur.

The data were collected through a series of research flights, providing a detailed analysis of atmospheric particles present in the region. Notably, while scientists had previously identified the particles during another expedition, the complete physical-chemical mechanism had not yet been understood. This research enables new Earth system models, allowing climate simulations that further our understanding of the planet’s functioning.

The study was conducted by a team of specialists from the University of São Paulo (USP), the National Institute for Space Research (Inpe), the National Institute for Amazonian Research (Inpa), Goethe University Frankfurt, and the Max Planck Institute for Chemistry in Germany, with a base established in Manaus (AM).

The group utilized data obtained during the scientific experiment CAFE-Brazil (Chemistry of the Atmosphere: Field Experiment in Brazil), which carried out flights over the Amazon Basin between December 2022 and January 2023, at an altitude of 14 kilometers — twice the height of Aconcagua, the highest point in South America. In total, there were 136 flight hours, covering 89,000 kilometers.

Results

According to the study “Isoprene nitrates drive new particle formation in Amazon’s upper troposphere”, the results indicate that the primary source of particles formed in the Amazon’s upper troposphere is the oxidation of isoprene, a natural chemical compound released by trees, which is considered an indicator of threats.

This gas, released as part of the plants’ respiratory process, especially in the tropical forest, reacts with nitrogen oxides released during lightning storms. This reaction process, known as particle nucleation, primarily occurs at dawn, resulting in the formation of particles that can reach concentrations of over 50,000 particles per cubic centimeter.

These particles grow in size during the day and can be transported over long distances, affecting not only the climate of the Amazon region but also the global climate. When they reach the lower atmosphere, these particles serve as nuclei for cloud formation and influence the amount of rainfall in different regions. Moreover, these clouds affect the amount of heat that Earth receives and reflects back into space, impacting the planet’s climate.

Climate Challenges

In response to the São Paulo Research Support Foundation (Fapesp), Brazilian researcher and meteorology professor Luiz Augusto Toledo Machado emphasized the importance of preserving the biome to mitigate the impacts of the climate crisis. “One of the highlights of this work is seeing how the Amazon has a symbiosis of complex mechanisms and important phenomena that act within the ecosystem’s delicate balance“, he explained.

Climatologist Mariana Lima from the University of São Paulo and co-author of the study highlighted the research’s direct implications for understanding global climatic patterns. “Understanding how the Amazon influences global climate dynamics is crucial for researchers and policymakers. The findings emphasize that the forest plays an essential role in climate regulation, and its preservation is fundamental for the planet’s sustainable future“, she stated.

The study’s results reinforce the urgency of measures to protect the Amazon, given its importance in maintaining the global climate balance. The research underscores the immediate need for preservation actions to ensure the continuity of the natural processes that regulate the global climate.

Translated from Portuguese by Gustô Alves