Multidecadal trend of increasing iron stress in Southern Ocean phytoplankton

Ryan-Keogh, Thomas JThomalla, Sandy JScheel Monteiro, Pedro MTagliabue, A2023-05-122023-05-122023-02Ryan-Keogh, T.J., Thomalla, S.J., Scheel Monteiro, P.M. & Tagliabue, A. 2023. Multidecadal trend of increasing iron stress in Southern Ocean phytoplankton. Science, 379(6634). http://hdl.handle.net/10204/127780036-80751095-9203DOI: 10.1126/science.abl5237http://hdl.handle.net/10204/12778Southern Ocean primary productivity is principally controlled by adjustments in light and iron limitation, but the spatial and temporal determinants of iron availability, accessibility, and demand are poorly constrained, which hinders accurate long-term projections. We present a multidecadal record of phytoplankton photophysiology between 1996 and 2022 from historical in situ datasets collected by Biogeochemical Argo (BGC-Argo) floats and ship-based platforms. We find a significant multidecadal trend in irradiance-normalized nonphotochemical quenching due to increasing iron stress, with concomitant declines in regional net primary production. The observed trend of increasing iron stress results from changing Southern Ocean mixed-layer physics as well as complex biological and chemical feedback that is indicative of important ongoing changes to the Southern Ocean carbon cycle.AbstractenClimate changePhytoplankton photophysiologySouthern Hemisphere climateThe Southern oceanMultidecadal trend of increasing iron stress in Southern Ocean phytoplanktonArticleRyan-Keogh, T. J., Thomalla, S. J., Scheel Monteiro, P. M., & Tagliabue, A. (2023). Multidecadal trend of increasing iron stress in Southern Ocean phytoplankton. Science, 379(6634), http://hdl.handle.net/10204/12778Ryan-Keogh, Thomas J, Sandy J Thomalla, Pedro M Scheel Monteiro, and A Tagliabue "Multidecadal trend of increasing iron stress in Southern Ocean phytoplankton." Science, 379(6634) (2023) http://hdl.handle.net/10204/12778Ryan-Keogh TJ, Thomalla SJ, Scheel Monteiro PM, Tagliabue A. Multidecadal trend of increasing iron stress in Southern Ocean phytoplankton. Science, 379(6634). 2023; http://hdl.handle.net/10204/12778.TY - Article AU - Ryan-Keogh, Thomas J AU - Thomalla, Sandy J AU - Scheel Monteiro, Pedro M AU - Tagliabue, A AB - Southern Ocean primary productivity is principally controlled by adjustments in light and iron limitation, but the spatial and temporal determinants of iron availability, accessibility, and demand are poorly constrained, which hinders accurate long-term projections. We present a multidecadal record of phytoplankton photophysiology between 1996 and 2022 from historical in situ datasets collected by Biogeochemical Argo (BGC-Argo) floats and ship-based platforms. We find a significant multidecadal trend in irradiance-normalized nonphotochemical quenching due to increasing iron stress, with concomitant declines in regional net primary production. The observed trend of increasing iron stress results from changing Southern Ocean mixed-layer physics as well as complex biological and chemical feedback that is indicative of important ongoing changes to the Southern Ocean carbon cycle. DA - 2023-02 DB - ResearchSpace DP - CSIR J1 - Science, 379(6634) KW - Climate change KW - Phytoplankton photophysiology KW - Southern Hemisphere climate KW - The Southern ocean LK - https://researchspace.csir.co.za PY - 2023 SM - 0036-8075 SM - 1095-9203 T1 - Multidecadal trend of increasing iron stress in Southern Ocean phytoplankton TI - Multidecadal trend of increasing iron stress in Southern Ocean phytoplankton UR - http://hdl.handle.net/10204/12778 ER -26618