Substantial loss of isoprene in the surface ocean due to chemical and biological consumption

Isoprene is the most abundant biogenic volatile organic compound emitted by the biosphere, with profound implications in atmospheric chemistry, plant ecology and climate. Even though the ocean is not as strong an isoprene source as vegetated land, the consequences of isoprene emission in the remote ocean atmosphere prompt to the need for developing predictive models. However, numerical models are limited by our poor knowledge of isoprene regulation processes in the ocean, particularly the sink terms: microbial and chemical degradation have been assumed to exist and have been prescribed as a constant in isoprene models without any experimental confirmation and quantification. In a paper in Communication in Earth & Environment, the authors show that isoprene degradation does occur in contrasting regions of the global ocean and propose equations to predict loss rates from measured or satellite chlorophyll. These new measurements have made it possible to redraw the isoprene cycle in the surface ocean across productivity regimes.

Reference: Simó, R., Cortés-Greus, P., Rodríguez-Ros, P., Masdeu-Navarro, M., (2022). Substantial loss of isoprene in the surface ocean due to chemical and biological consumption. Communications Earth & Environment, 3, 20. https://doi.org/10.1038/s43247-022-00352-6.