Glucose Enhances Salinity-Driven Sea Spray Aerosol Production in Eastern Arctic Waters

12 pages, 4 figures, 1 table, supporting information https://doi.org/10.1021/acs.est.4c02826

Sea spray aerosols (SSA) greatly affect the climate system by scattering solar radiation and acting as seeds for cloud droplet formation. The ecosystems in the Arctic Ocean are rapidly changing due to global warming, and the effects these changes have on the generation of SSA, and thereby clouds and fog formation in this region, are unknown. During the ship-based Arctic Century Expedition, we examined the dependency of forced SSA production on the biogeochemical characteristics of seawater using an on-board temperature-controlled aerosol generation chamber with a plunging jet system. Our results indicate that mainly seawater salinity and organic content influence the production and size distribution of SSA. However, we observed a 2-fold higher SSA production from waters with similar salinity collected north of 81°N compared to samples collected south of this latitude. This variability was not explained by phytoplankton and bacterial abundances or Chlorophyll-a concentration but by the presence of glucose in seawater. The synergic action of sea salt (essential component) and glucose or glucose-rich saccharides (enhancer) accounts for >80% of SSA predictability throughout the cruise. Our results suggest that besides wind speed and salinity, SSA production in Arctic waters is also affected by specific organics released by the microbiota

This work was funded by the Spanish Ministerio de Ciencia e Innovación (MICIN) through an FPI grant (PRE2020-092994) to A.R., the project POLAR CHANGE (PID2019-110288RB-I00) to M.D′O., R.S. and E.B., and the project SIMPATICO (PCI2019-111895-2) to M.D′O. A.R. also received support from the European Social Fund (ESF) ‘Investing in your Future’. A.v.J. was financed by the Helmholtz Association. V.P. was supported by the Federal scientific and technological program for ecological development of the Russian Federation for 2021–2030. This study is part of the POLARCSIC platform activities with the institutional support of the ‘Severo Ochoa Centre of Excellence′ accreditation (CEX2019-000928-S)

Peer reviewed