Marine Sugars Travel Up to the Free Troposphere

Microorganisms produce carbohydrates in the surface ocean, which are then transferred into the atmosphere as part of sea spray aerosol particles. These compounds have been detected in the air during recent field campaigns, mostly at coastal sites and aboard research vessels. In remote marine regions such as the Southern Ocean, where dust emissions are low, marine carbohydrates are thought to account for most ice-nucleating particles active between −20 and −15°C. Consequently, they may play an important role in cloud formation and cloud properties. However, an open question remains: to what extent, and under which conditions, do these complex macromolecules reach the cloud-relevant altitudes?

To address this knowledge gap, Zeppenfeld et al. measured several sea spray constituents at different atmospheric heights using a tethered balloon system in Ny-Ålesund, Svalbard. The results show that marine carbohydrates occur at similar, lower, or even higher concentrations aloft compared to ground level. This variability can largely be explained by mixing state and prevailing atmospheric conditions. Remarkably, these compounds were detected even in the free troposphere, demonstrating that they can be transported far above the marine boundary layer, and confirming their atmospheric relevance beyond laboratory and modelling studies.

The findings of this study provide the first comprehensive picture of how primary sea-to-air transfer, long-range transport, in situ formation, and atmospheric processing together shape the vertical distribution of marine carbohydrates in the atmosphere, adding further evidence for their potential relevance to cloud properties

Reference: Zeppenfeld, S., Schaefer, J., Pilz, C.,et al. (2026). Marine carbohydrates and other sea spray aerosol constituents across altitudes in the lower troposphere of Ny-Ålesund, Svalbard. Atmos. Chem. Phys., 26, 7235–7260.
https://acp.copernicus.org/articles/26/7235/2026/