Fate of Phosphorus during Photochemical Cycling of Iron Oxyhydr(oxides) in the Upper Ocean

陆源粉尘是海洋营养物贫乏地区微量营养元素铁（Fe）的重要来源。 来自风沙输入的铁主要以羟基氧化铁的形式存在，由于其对磷（P）的强烈亲和力，因此有大量的这种营养物质与之相关。这些营养物质共同影响初级生产。 一旦灰尘被引入到阳光照射的表面沃茨，羟基氧化铁颗粒受到光还原溶解，这提高了生物可利用的铁，但这个过程对相关的P的影响是未知的。 夏威夷大学的研究人员计划使用合成的羟基氧化铁和天然灰尘样本进行一系列实验室实验，以确定一旦这些颗粒被光化学还原，与这些颗粒相关的P的命运。 从这项研究的结果将建立富铁粉尘是否是一个源，现有的生物可利用的P或汇，由于通过吸附清除的结果，重复的光化学溶解/再沉淀循环的铁羟基氧化物在海洋环境中的去除。 更广泛的影响：除了对磷循环提供新的见解外，这项研究还将支持和培训一名夏威夷血统的研究生。

Terrestrially-derived dust is an important source of the micronutrient iron (Fe) to nutrient-depleted regions of the oceans. The Fe from aeolian inputs is predominantly in the form of ferric oxyhydroxide which because of its strong affinity for phosphorus (P) have significant amounts of this nutrient associated with it. Together these nutrients can impact primary production. Once dust is introduced to sunlit surface waters, the ferric oxyhydroxide particles are subject to photoreductive dissolution which enhances bioavailable Fe but the impact of this process on the associated P is unknown. Researchers at the University of Hawaii plan to carry out a series of laboratory experiments using synthetic ferric oxyhydroxides and natural dust samples to determine the fate of P associated with these particles once they are photochemically reduced. Results from this study will establish whether Fe-rich dust is a source to the existing bioavailable pool of P or a sink due to removal via sorptive scavenging as a consequence of repetitive photochemical dissolution/re-precipitation cycles of ferric oxyhydroxides in the marine environment. Broader Impacts: Besides providing new insights on the phosphorus cycle, this research would support and train one graduate student of Hawaiian descent.