2023年2月24日出版的《科学》杂志发表了南非南大洋碳气候观测站Thomas J. Ryan-Keogh课题组的最新成果，他们报道了南大洋浮游植物铁胁迫增加的多年代际趋势。

小组通过生物地球化学Argo(BGC-Argo)浮标和船基平台收集的历史原位数据集，介绍了1996年至2022年的浮游植物光生理的几十年记录。研究人员发现由于铁应力的增加，辐照度标准化的非光化学猝灭具有显著的多年代际趋势，同时伴随着区域净初级产量的下降。观测到的铁压力增加趋势是南大洋混合层物理变化以及复杂的生物和化学反馈造成的，这表明南大洋碳循环正在发生重要的变化。

研究人员表示，南大洋初级生产力主要受光和铁限制的调整控制，但铁的可用性、可获得性和需求的空间和时间决定因素制约得很差，这阻碍了准确的长期预测。

附：英文原文

Title: Multidecadal trend of increasing iron stress in Southern Ocean phytoplankton

Author: Thomas J. Ryan-Keogh, Sandy J. Thomalla, Pedro M. S. Monteiro, Alessandro Tagliabue

Issue&Volume: 2023-02-24

Abstract: 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.

DOI: abl5237

Source: https://www.science.org/doi/10.1126/science.abl5237