Investigating the formation of oxidants and secondary organic aerosols from biogenic hydrocarbons in the Amazonia region of northern Brazil

Description

This project seeks to investigate the lifecycle cycle of secondary aerosols in pristine and polluted environments in the Amazonia region of northern Brazil. The study is part of the GOAmazon project. The investigation spans biological, chemical, and physical conditions influencing emissions and reactions of forest-emitted volatile organic compounds (VOCs). Also, the investigation seeks to determine the formation and transport of aerosols from the convective boundary layer out to the cloud layer with the view to examine their influence on cloud formation and onset of rainfall. In this presentation, the chemical processing of the forest-emitted VOCs will be examined utilizing Large Eddy Simulations and one-dimensional photochemical models. Formation of oxidants and secondary organic aerosols will be determined as a function of nitrogen oxide levels and turbulence length scales and associated air parcel residence times in the forest canopy space. It is of great scientific importance to estimate the yields of secondary organic aerosols and oxidants formed from the reactions of VOCs subject to different levels of nitrogen oxides such as those experienced in polluted air masses. Interactions of nitrogen oxides and forest-emitted VOCs are crucial to understand and quantify because locales such as the Amazonia region are becoming increasingly impacted by anthropogenic emissions. To better understand the life cycle of aerosols after they enter the atmospheric boundary layer, quasi-Lagrangian balloons will observe lower-atmosphere trajectories. The interplay of biogenic and anthropogenic emissions of volatiles and nitrogen oxides, modified by turbulent mixing processes in the boundary layer, can influence the chemical composition of the aerosols that activate into cloud condensation nuclei. This presentation will provide ab initio results to address these research questions.