Aerosols are collections of fine particles, either biological or of other types, in suspension in a gaseous medium. They play a major role in cloud formation and therefore have a strong impact on climate models. They are however extremely hard to study due to the small size and immense variety of their constituent particles. But researchers have now succeeded in linking the composition of marine biological aerosols — and therefore their influence on the climate — to that of bodies of water under them within the Atlantic Ocean, thereby paving the way to an indirect study of these aerosols through water analysis.