Formation, Clustering, and Atmospheric Impact of Clusterable Organic Compounds

Introduction

Atmospheric aerosol particles have a critical impact on Earth’s radiative balance and human health. Oxygenated organic molecules play an important role in the formation and growth of aerosol particles.

Particle Formation Mechanisms

To contribute to the initial steps of particle formation, a compound must either condense from the gas to the particle phase or undergo cluster-phase proton-transfer or other chemical reactions. I define a clusterable organic compound (COC) to be an oxygenated organic molecule that can participate in stable cluster formation under atmospheric conditions.

Knowledge Gaps

Due to the limited knowledge of the formation, structures, and properties of COCs, the exact mechanisms for the formation of aerosol particles remain puzzling.

Vision and Approach

My vision to bridge this long-lasting knowledge gap is to implement a unique computational approach to tackle bottlenecks in studies of complex reaction mechanisms. This includes:

1. Combining a versatile suite of quantum chemical methods to accurately investigate cluster formation and properties.
2. Merging the best qualities of mass spectrometry and matrix isolated vibrational spectroscopy to solve structures directly from the reaction chamber.

Scientific Objectives

The scientific objectives are to:

1. Solve the role of the dimerization-initiated autoxidation mechanism in COC formation.
2. Develop instrumentation capable of revealing molecular structures and properties of COCs.
3. Determine the formation mechanisms and rates of COC-containing particles.
4. Estimate the atmospheric impact of newly formed COC-containing particles.

Impact of Research

This project will establish the molecular-level foundation for future atmospheric research by solving how COCs form, what their contribution to particle formation and properties is, and what their impact is for our climate.

This research results in highly accurate reaction kinetics and cluster thermodynamics parameters for atmospheric models, which are crucial to constrain the large uncertainty in climate predictions caused by small aerosol particles.