NASA Fellowship Award to Matthew Brege
Matthew Brege was awarded the 2015 NASA Earth and Space Science Fellowship for his proposal involving the aqueous phase processing of biomass burning emissions. A summary of the proposal is provided below.
Gas phase methoxyphenols can undergo chemical oxidation in clouds. The oxidized lower volatility products form SOA as droplets dry. Multiple cloud cycles of evaporation and condensation may further transform the methoxyphenol SOA.
Proposal Summary: Atmospheric processing of the primary emissions from biomass burning contributes to the formation of light absorbing secondary organic aerosol (SOA), which is often referred to as humic-like substances (HULIS). Recently methoxyphenols from the pyrolysis of lignin were found to be an important precursor of light absorbing SOA. Atmospheric oxidation of methoxyphenols occurs in both the gas and aqueous phase, but the extent and fate of its chemical transformation has not been addressed. In this research, we hypothesize that the aqueous phase transformation of methoxyphenols in suspended cloud droplets is greatly enhanced by the increased surface area to volume ratio compared to bulk solutions. To address this, a unique set of experiments is proposed using a newly developed state-of-the-art multiphase reaction chamber to simulate cloud processes and explore the interactions and chemical transformation of methoxyphenols. The following science questions will guide the research:
- What are the aqueous phase properties (e.g., droplet size, pH, composition, etc.) that affect SOA production from methoxyphenols?
- What fraction of the SOA is light absorbing and what is its primary chromophore?
- What are the optical and nucleation properties of the SOA from methoxyphenols?
- What parallels in the composition can be observed between laboratory methoxyphenol SOA and ambient cloud/fog samples?