The interface layer between ocean and atmosphere is only a couple of micrometers thick but playsa critical role in climate relevant processes, including the air-sea exchange of gas and heat and theemission of primary organic aerosols (POA). Recent findings suggest that low-level cloud formationabove the Arctic Ocean may be linked to organic polymers produced by marine microorganisms. Seaice harbors high amounts of polymeric substances that are produced by cells growing within the seaicebrine. Here, we report from a research cruise to the central Arctic Ocean in 2012. Our study showsthat microbial polymers accumulate at the air-sea interface when the sea ice melts. Proteinaceouscompounds represented the major fraction of polymers supporting the formation of a gelatinousinterface microlayer and providing a hitherto unrecognized potential source of marine POA. Our studyindicates a novel link between sea ice-ocean and atmosphere that may be sensitive to climate change.

Supplement to: Galgani, Luisa; Piontek, Judith; Engel, Anja (2016): Biopolymers form a gelatinous microlayer at the air-sea interface when Arctic sea ice melts. Scientific Reports, 6, 29465