Understanding the climate effects of the sea-surface microlayer: Structural and chemical evolution of organic monolayers upon reaction with molecular beams of OH radicals

Our research aims to unlock new insights into atmospheric chemistry and its effects on climate by investigating how airborne particles undergo oxidative ageing. We will employ advanced neutron and infrared reflectometry techniques to generate crucial experimental evidence demonstrating that self-assembled monolayers (SAMs) of thioalkyls or oleic acid on gold can serve as effective tools in cutting-edge high-vacuum molecular scattering experiments, enabling the control of surface functional groups and acting as proxies for the organic films present on sea spray aerosols. These films are composed of natural surfactants from the ocean’s surface and play a significant role in cloud formation and atmospheric processes. By scattering molecular beams containing reactive OH radicals off these SAMs, we will replicate oxidative processes that naturally occur in the atmosphere, providing a detailed investigation of oxidation mechanisms. Success in this ISIS experiment would pave the way for new opportunities to explore structural changes and oxidation pathways, offering a novel approach to simulating atmospheric ageing. This research forms part of a broader effort to understand how surfactants affect cloud condensation nuclei (CCN) activity, which in turn influences cloud albedo and Earth's energy balance. The insights gained will enhance climate models, shedding light on the role of atmospheric particles in shaping cloud properties and impacting global climate.