Seventy per cent of Earth’s surface is covered by the ocean, but at present, we know very little about the role sea spray aerosol plays in triggering ice formation in clouds - a fundamentally important process since clouds play a key role in climate and the hydrological cycle. Despite the significance of ice formation, our quantitative understanding of sources, properties, mode of action and transport of Ice-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 major aerosol types, including those from the world’s oceans.
Sea spray is one of the dominant aerosol types in the atmosphere. There are strong indications that biological organic components of sea spray can nucleate ice, but there is a lack of data to quantify it. In contrast, the ice-nucleating ability of major aerosol species from terrestrial sources, such as mineral dusts or bacteria, has received significant attention over the past few decades. By gathering field data, the MarineIce project will help us better understand marine INP and improve models.
Data will be gathered using a new semi-autonomous INP instrument which will cover the full range of mixed-phase cloud temperatures. It will be housed in a unique mobile laboratory, allowing us to access remote oceans from atmospheric observatories and research ships. The data from these campaigns will be used to constrain the oceanic INP source and define the spatial and temporal distribution of marine INP in global aerosol models. This data will be used to help create the next generation of weather and climate models.