Ocean eyes: Developing novel optical chemical measurements of trace elements

海水中的铁（Fe）具有高度的颗粒反应性，很容易通过下沉的颗粒去除，但尽管海洋颗粒很重要，但对其元素组成的了解相对较少。UoP和UoL海洋实验室拥有世界上少数海洋省份的海洋和大气微量金属颗粒数据[1-5]。然而，颗粒分析是费力和昂贵的，这意味着原位传感器分析是一个非常理想的前景。我们来自NERC陆架海洋生物地球化学项目的数据增强了对英国陆架水域铁动力学的理解[6-9]。最近，我们发现Fe与光学参数（如浊度）显着相关，为原位光学和光谱（即UV-Vis， IR和荧光）代理（未发表的数据）打开了令人兴奋和新颖的可能性之门。此外，还有可能通过卫星仪器自动（即海洋滑翔机和漂浮物）和远程获取颗粒元素分布。本研究的总体目标是研究悬浮海洋颗粒的光学和光谱特性，作为铁浓度的代用物。由于最近GEOTRACES项目、生物地球化学- argo浮标网络、远程通信以及将光学/光谱传感器集成到浮标和自动驾驶车辆中，该项目非常及时。目标1：完成对海水中合成矿物相和表征海洋沉积物/SPM的元素、光学和光谱特性的综合实验室研究（普利茅斯和利兹实验室）。目标2通过每月在西海峡天文台（WCO）进行海洋悬浮粒子、光学测量和微量元素的调查来检验假设。目标3使用过去和当前的传感器数据、卫星观测、时间序列数据（即百慕大BATS），研究使用确定的代用物在区域/盆地尺度上绘制颗粒元素浓度图的潜力。

Iron (Fe) in seawater is highly particle reactive and easily removed via sinking particles but despite the importance of marine particles, relatively little is known of their elemental composition. UoP and UoL marine labs have some of the few particulate marine and atmospheric trace metal data for ocean provinces in the world [1-5]. However, particle analysis is laborious and costly, meaning in situ sensor analysis is a highly desirable prospect.Our data from the NERC Shelf Sea Biogeochemistry programme led to an enhanced understanding of Fe dynamics in UK shelf waters [6-9]. More recently, we found that Fe is significantly correlated with optical parameters such as turbidity, opening the door to exciting and novel possibilities of in situ optical and spectroscopic (i.e. UV-Vis, IR and fluorescence) proxies (unpublished data). Furthermore, there is potential for particulate element distributions to be obtained autonomously (i.e. ocean gliders and floats) and remotely via satellite instrumentation.The overall aim of this studentship is to investigate optical and spectroscopic properties of suspended marine particles as proxies for iron concentrations. The project is timely due to the recent availability of data from GEOTRACES programmes, Biogeochemical-Argo float network, tele-communications and integration of optical/spectroscopic sensors into buoys and autonomous vehicles.Objectives: The student will focus on 3 core objectives: Objective 1 complete a comprehensive laboratory study of the elemental, optical and spectroscopic properties of synthesised mineral phases and characterised marine sediments/SPM in seawater (Plymouth and Leeds labs). Objective 2 test hypotheses with monthly surveys of marine suspended particles, optical measurements and trace elements at the Western Channel Observatory (WCO) Objective 3 use past and current sensor data and satellite observations, time series data (i.e. Bermuda BATS) to investigate the potential for mapping particulate element concentrations at regional/basin scales using determined proxies.