The microphysical effects of aerosol-radiation and aerosol-cloud interactions and their impacts on the radiative balance in the Amazon

• Grant number: 25/00706-8
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: July 01, 2025
• End date: February 28, 2030
• Field of knowledge: Physical Sciences and Mathematics - Geosciences
• Principal Investigator: Paulo Eduardo Artaxo Netto
• Grantee: Pedro Henrique Teixeira Tavares
• 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

Atmospheric aerosols influence regional and global climate by altering the radiative balance via two fundamental mechanisms: 1) direct scattering and absorption of solar and thermal radiation and 2) changes in cloud microphysics. These two mechanisms are the largest source of uncertainty in climate simulations, according to the Intergovernmental Panel on Climate Change (IPCC). This work aims to combine remote sensing measurements from a long-term data series (about 22 years) collected in the Amazon through the AERONET network, operated in partnership with NASA, with more recent sensor measurements from satellites, including polarization data, to advance the understanding of the role of aerosols in this balance. This set of point measurements (AERONET) and extensive measurements for the entire Amazon basin (satellites) provides a new perspective on the Earth's radiative balance, especially when used alongside radiative transfer models. The goal is to calculate the radiative forcing of aerosols across the Amazon and analyze their impacts on ecosystem functioning, such as carbon balance. Studies will also be conducted on the indirect impacts of aerosols on clouds, with changes in albedo over the Amazon, through the Towney effect, which makes clouds brighter when they have a high aerosol load. Vertical profile measurements of aerosols will allow the study of the vertical distribution of these changes in the radiative balance, enabling an examination of the balance between black and brown carbon absorption and the optical scattering caused by organic aerosols in the Amazon.