德国基尔GEOMAR Helmholtz海洋研究中心 Browning, Thomas J. 在研究 ENSO 强迫下持续的赤道太平洋铁限制中取得新进展。该项研究成果发表在2023年8月16日出版的《自然》上。

研究人员表明，物理作用力的变化通过多个厄尔尼诺/南方涛动(ENSO)周期驱动了赤道太平洋铁限制强度的一致波动，但这被最新的气候模型高估了两倍。研究的评估首先通过结合使用现场营养添加实验、蛋白质组学和水上超光谱辐射测量，来显示浮游植物对铁限制的生理反应，引起叶绿素标准化浮游植物荧光约三倍的变化。

然后，研究人员利用超过 18 年的卫星荧光记录来量化气候引起的营养限制可变性。这种天气限制提供了一种强有力的方法来衡量净初级生产力对气候变化的模式预测的现实性。

据悉，海洋净初级生产力对气候变化的预测反应非常不稳定。模型表明，低纬度太平洋浮游植物营养限制的气候敏感性起着至关重要的作用，但这很少受到观测的约束。

附：英文原文

Title: Persistent equatorial Pacific iron limitation under ENSO forcing

Author: Browning, Thomas J., Saito, Mak A., Garaba, Shungudzemwoyo P., Wang, Xuechao, Achterberg, Eric P., Moore, C. Mark, Engel, Anja, Mcllvin, Matthew R., Moran, Dawn, Voss, Daniela, Zielinski, Oliver, Tagliabue, Alessandro

Issue&Volume: 2023-08-16

Abstract: Projected responses of ocean net primary productivity to climate change are highly uncertain1. Models suggest that the climate sensitivity of phytoplankton nutrient limitation in the low-latitude Pacific Ocean plays a crucial role, but this is poorly constrained by observations. Here we show that changes in physical forcing drove coherent fluctuations in the strength of equatorial Pacific iron limitation through multiple El Nino/Southern Oscillation (ENSO) cycles, but that this was overestimated twofold by a state-of-the-art climate model. Our assessment was enabled by first using a combination of field nutrient-addition experiments, proteomics and above-water hyperspectral radiometry to show that phytoplankton physiological responses to iron limitation led to approximately threefold changes in chlorophyll-normalized phytoplankton fluorescence. We then exploited the >18-year satellite fluorescence record to quantify climate-induced nutrient limitation variability. Such synoptic constraints provide a powerful approach for benchmarking the realism of model projections of net primary productivity to climate changes.

DOI: 10.1038/s41586-023-06439-0

Source: https://www.nature.com/articles/s41586-023-06439-0