Molecular modelling of atmospheric abundant volatile biogenic compound identified over Amazon Rainforest

• Grant number: 22/01284-1
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: July 01, 2022
• End date: February 28, 2027
• Field of knowledge: Physical Sciences and Mathematics - Physics - Atomic and Molecular Physics
• Principal Investigator: Kaline Rabelo Coutinho
• Grantee: Emanuel Fernandes Dias Mancio
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

In recent decades, the Amazon region has undergone a significant change in the dynamics of land use and occupation. These changes have significantly contributed to the increase in the concentration of aerosol particles and greenhouse gases in the atmosphere. Although there are great advances in research in the environmental area, especially in climate change, the role of biogenic aerosol particles in the atmosphere is a current topic and quite lacking in scientific investigations. Aerosol particles play a fundamental role in the hydrological cycle, as they are known as precursors of Cloud Condensation Nuclei (CCN), which participate together with water vapor to form cloud droplets. More than 60% of the aerosol particles emitted by the Amazon rainforest are capable of acting as CCN. Due to the heterogeneity of aerosol particles and the increase in pollutant emissions into the atmosphere in the Amazon region, the need for studies on the effect of aerosols on climatic phenomena, as well as the effect of pollutants on natural biogenic particles, in order to obtain information related to the characteristics of these particles in an aqueous environment in the presence of pollutants, as well as to investigate how pollutants affect the interactions of these particles with water. These studies are important because these polluting particles affect the physicochemical properties of the drops, mainly the surface properties, altering the life cycle of the clouds.In this project we will carry out a theoretical study of molecular modeling, through quantum calculations and classical computer simulations, of natural biogenic molecules in aqueous solution with pollutants. With these biogenic molecules in the presence of pollutants, we will first study in aqueous solution the electronic properties and interactions of these molecules with the environment under thermodynamic conditions analogous to cloud drops. Then, the same properties of these molecules will be investigated under conditions that mimic the surface of a drop, in order to compare the bulk and surface properties. In addition, we will study the effect of pollutants on intermolecular solute-solvent interactions, in order to investigate the changes caused by pollutants in these interactions, in order to identify the direct effect of pollutant molecules on droplet formation and precipitation. (AU)