Particle Export during the Southern Ocean Iron Experiment (SOFeX)

虽然铁的加入可以刺激浮游植物的生长，改变上层海洋的地球化学，但人们对铁的有效性对沉降颗粒通量的净影响知之甚少。 如果Fe在过去的CO2变化中发挥了重要作用，或者由于故意操纵海洋生态系统，Fe对CO2的长期影响，那么量化碳和相关元素的输出通量的净变化对Fe负载的响应就变得至关重要。 因此，PI将在南大洋铁实验（SOFeX）期间使用天然放射性核素钍-234量化颗粒有机碳和颗粒有机氮输出的变化。 利用SOFeX研究区内外获得的234 Th时间序列剖面，PI将能够研究Fe负载和群落结构变化的出口响应，并协助计算响应Fe添加的碳和营养通量。 关于上层海洋对铁富集的出口反应的信息将用于了解过去海洋对铁/尘埃输入的反应，并评估拟议用于抵消二氧化碳排放的故意铁施肥的未来影响。

ABSTRACTOCE-9987501While it has been shown that the addition of Fe can stimulate phytoplankton growth and alter upper ocean biogeochemistry, little is know about the net effect of Fe availability on sinking particle fluxes. If Fe played an important role in past variations in CO2 or if there will be long term effects of Fe on CO2 due to deliberate manipulation of ocean ecosystems, then it becomes essential to quantify the net change in export fluxes of carbon and associated elements in response to Fe loading. For this reason, the PI will quantify changes in particulate organic carbon and particulate organic nitrogen export during the Southern Ocean Iron Experiment (SOFeX) using the naturally occurring radionuclide thorium-234. Using time-series profiles of 234Th obtained both inside and outside of the SOFeX study area, the PI will be able to study the export response to changes in Fe loading and community structure, as well as assist in the calculation of the carbon and nutrient fluxes in response to the Fe additions. Information on the export response of the upper ocean to Fe enrichment will be used to understand past oceanic responses to Fe/dust inputs and assess future impacts of deliberate Fe fertilization proposed to offset carbon dioxide emissions.