Photosynthetic electron, carbon, and oxygen fluxes within a mosaic of Fe limitation in the California Current upwelling system

Sezginer, Yayla; Schuler, Kate; Speciale, Emily; Marchetti, Adrian; Till, Claire; Till, Ralph; Tortell, Philippe

doi:https://doi.org/10.5194/bg-22-5257-2025

Articles | Volume 22, issue 19

https://doi.org/10.5194/bg-22-5257-2025

© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/bg-22-5257-2025

© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 22, issue 19

Research article

|

02 Oct 2025

Research article |

| 02 Oct 2025

Photosynthetic electron, carbon, and oxygen fluxes within a mosaic of Fe limitation in the California Current upwelling system

Yayla Sezginer, Kate Schuler, Emily Speciale, Adrian Marchetti, Claire Till, Ralph Till, and Philippe Tortell

Data sets

May-June 2023 California Current Thermosalinograph Data Yayla Sezginer et al. https://doi.org/10.1594/PANGAEA.977780

May-June 2023 California Current Pressure In Situ Gas Instrument (PIGI) Data Yayla Sezginer et al. https://doi.org/10.1594/PANGAEA.977807

May-June 2023 California Current Fast Repetition Rate Fluorometer (FRRF) Data Yayla Sezginer and Philippe Tortell https://doi.org/10.1594/PANGAEA.977630

Model code and software

O2N2_NCP_toolbox Philippe Tortell and Robert W. Izett https://github.com/rizett/O2N2_NCP_toolbox

Short summary

We recorded three metrics of photosynthesis in the California Current. Real-time observations of microalgae physiology and productivity revealed signs of iron limitation where the continental shelf rapidly dropped off. Iron limitation influenced how efficiently light was absorbed and used for carbon fixation but did not appear to affect net photosynthetic oxygen production. Our results offer useful insights into efforts to model carbon fixation rates from microalgae optical properties.