PostDoctoral Research Fellowship in Polar Regions

该奖项是授予博士后奖学金的。这位研究人员将研究南大洋铁供应对南极洲棕囊藻溶解有机碳的大小、组成和生物有效性的影响。南极洲是一种分布广泛的殖民地浮游植物物种。南极洲在从大气中吸收二氧化碳方面非常有效，因为它的生物量不被食草动物循环回二氧化碳，而且它的生物量被观察到迅速下降。这些特点使得南极冰盖成为一种有趣的自然机制，可以从大气中清除二氧化碳，以便长期埋葬和保存。在罗斯海，铁已被确定为南极洲微藻生产的限制营养物质，但浮游植物收集和利用铁的机制仍不清楚。这项调查将试图确定南极洲是否会释放与铁形成络合物的有机物，以催化铁向自身或异养细菌的细胞转移，即帮助浮游植物和浮游细菌克服生长限制因素--分别是铁和溶解的有机碳--的过程。这将通过一种合作的方法来实现，即利用金属和有机质谱学相结合的技术，在实验室和现场确定浮游植物产生的溶解有机物的特征。

This award is for a postdoctoral fellowship. The investigator will study the effects of the supply of iron in the Southern Ocean on the size, composition, and bioavailability of dissolved organic carbon from Phaeocystis antarctica, a widely distributed species of colonial phytoplankton.P. antarctica is quite efficient in drawing down carbon dioxide from the atmosphere, because its biomass is not recycled by grazers back to carbon dioxide, and its biomass is observed to sink rapidly. These characteristics make P. antarctica blooms an interesting natural mechanism for removing carbon dioxide from the atmosphere for long term burial and preservation. In the Ross Sea, iron has been identified as the limiting nutrient for P. antarctica production, but the mechanisms phytoplankton employ to collect and utilize iron remain unknown. This investigation will attempt to determine if P. antarctica release organic matter that complexes iron to catalyze the cellular transfer of iron to either themselves or heterotrophic bacteria, that is, the processes that help phytoplankton and bacterioplankton overcome their growth limiting factors - respectively iron and dissolved organic carbon. This will be accomplished through a collaborative approach by characterizing dissolved organic matter produced by the phytoplankters in the laboratory and in the field using combined metals and organic mass spectral techniques.