Abstarct: Detecting seasonal shifts in phytoplankton taxa and primary production in the Southern Ocean

摘要：检测南大洋浮游植物类群和初级生产的季节性变化

• 批准号: 2706255
• 金额: --
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2706255
• 关键词: Abstarct; Detecting; seasonal; shifts; phytoplankton

The Southern Ocean is the only ocean without continental constraints, moving in an uninterrupted flow around Antarctica [1]. This distance from major land masses results in a reduction in the aeolian nutrient input, including iron, a trace metal essential for the metabolic function of phytoplankton [1, 2, 3]. Therefore, most of this Southern Ocean is seen to be iron limited, and characterised by High Nutrient, Low Chlorophyll (HNLC) waters. There is a seasonal cycle in surface phytoplankton growth. Generally, the austral winter is dominated with strong wind mixing events (light limiting), while the summer sees a strongly stratified surface layer (nutrient limited). Both these growth conditions are associated with a dominance of small eukaryotic nanoflagellates. The most productive time in the Southern Ocean's annual cycle, is the spring, where a phytoplankton bloom of diatoms is observed. These blooms are followed by a significant increase in the export of particulate organic carbon (POC), increasing the Southern Ocean's ability to remove carbon from the atmosphere, transporting it to depth [4].

南大洋是唯一不受大陆限制的海洋，围绕南极洲不间断地流动[1]。与主要陆地的距离导致风成养分输入减少，包括铁，一种对浮游植物代谢功能至关重要的微量金属[1,2,3]。因此，南大洋的大部分地区被视为铁含量有限，并以高营养、低叶绿素 (HNLC) 水域为特征。表层浮游植物的生长存在季节性周期。一般来说，南半球冬季以强风混合事件为主（光照限制），而夏季则出现强烈分层的表层（养分有限）。这两种生长条件都与小型真核纳米鞭毛虫的优势有关。南大洋年度循环中生产力最高的时间是春季，此时可以观察到浮游植物硅藻的大量繁殖。这些水华之后，颗粒有机碳（POC）的输出显着增加，增加了南大洋从大气中去除碳并将其输送到深处的能力[4]。