Phytoplankton Blooms Influence Photochemistry at the OceanSurface

The sea-surface microlayer (SML) is the thin boundary interface between the ocean and the atmosphere, and it is expected to play a crucial role in atmospheric chemistry on a global scale. A novel study based on a controlled mesocosm experiment shows that biological events, such as phytoplankton blooms, can significantly enhance the photochemical production of carbonyl compounds at the ocean surface. By comparing compound-specific concentration in SML and underlying water samples before and after irradiation, Jibaja Valderrama et al. from the Leibniz Institute for Tropospheric Research (TROPOS) found stronger photochemical activity in the SML, particularly in periods of higher biological productivity. These results, recently published in Biogeosciences, offer new insights to integrate biological processes and photochemistry in the air-sea boundary, and point to their implications for the emission of volatile organic compounds (VOCs) to the marine atmosphere.

Reference: Valderrama, O.J., Firak, D.S., Schaefer, T., et al. (2026). Photochemistry of the sea-surface microlayer (SML) influenced by a phytoplankton bloom: a mesocosm study. Biogeosci., 23, 1965-1985. https://doi.org/10.5194/bg-23-1965-2026