The formation of ice in clouds is fundamentally important to life on our planet since clouds play a key role in climate and hydrological cycle. Despite the significance of ice formation, our quantitative understanding of sources, properties, mode of action and transport of Ince-Nucleating Particles (INP) is poor. In order to improve our representation of clouds in models we need to understand the ice-nucleating ability of all amor aerosol types, including those of the worlds oceans. Despite oceans covering over 70% of the planet and sea spray being one of the dominant aerosol types in the atmosphere, its role in the formation of ice in clouds in poorly understood. Sea-spray aerosol contains large amounts of organic material that is ejected into the atmosphere during bubble bursting at the organically enriched sea-air interface or sea surface micro layer.
Ben will present results demonstrating that organic material in the sea surface micro layer, collected in the Arctic and N-Atlanntic, nucleates ice under conditions relevant for mixed-phase clouds. The ice-nucleating material is probably biogenic and less that approximately 0.3 micrometers in size.
Finally, he will present new global model simulations of marine organic aerosol which suggest tat marine organic material may be an important source of ice-nucleating particles in remote marine environments such as the Southern Ocean, North Pacfic Ocean and North Atlantic Ocean.