Ocean eyes: Developing novel optical chemical measurements of trace elements

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to exciting and novel possibilities of in situ optical and spectroscopic (i.e. UV-Vis, IR and fluorescence) proxies (unpublished data).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.