Arctic Fjords: simplified modelling and the role of freshwater
(Arctic Project 5)
Mike Meredith (Primary supervisor at BAS)
Finlo Cottier (Main supervisor at SAMS)
Mark Inall (SAMS)
Povl Abrahamsen (BAS)
Observations show that the Arctic is undergoing unprecedented change, and model forecasts indicate that the pace of change will continue unabated. One of the major elements of the Arctic marine system that is reacting to change is the contribution of freshwater. Glaciers, rivers, sea ice and precipitation are all sources of freshwater into the Arctic, and each is susceptible to variations in climate. There remain significant uncertainties about the relative contributions of freshwater sources within coastal and shelf waters. It is important to better determine these, especially in order to understand the interaction between warm ocean waters and tidewater glaciers, which is one of the most active and exciting areas of oceanography in the Arctic. The delivery of heat from the ocean, through the fjord to the glacier is a key process in understanding the action of the ocean on glacial melting.
This project will focus on the fjords and coastal waters around the Svalbard archipelago, one of the most readily-accessible areas of the high Arctic. Here, a systematic characterisation of the freshwater signatures and distribution will be undertaken to establish the relative contributions of freshwater sources. Simplified box models will be used to represent and constrain the freshwater elements of fjord systems, since they can quantify the relative importance of the physical processes occurring within the fjord that control or modify the delivery of warm water to the glacier. An important constraint in such box models is the need to incorporate freshwater processes adequately. Salinity measurements can be used to understand the time-varying quantity of freshwater in the ocean, but they do not directly reveal the relative importance of its sources. The ratios of stable isotopes of oxygen in seawater, when measured in addition to salinity, provide a strong constraint on the importance of sea ice melt versus glacial melt and other freshwater inputs.
The student will:
1. Construct simplified box models for Svalbard fjordic systems, including a coupled sea ice module. Challenge these models with existing datasets from Billefjorden.
2. Compile existing oxygen isotope data from Atlantic- and Arctic-dominated coastal sites (Kongsfjorden and Rijpfjorden) to establish salinity/δ18O relationships and freshwater budgets for these contrasting systems.
3. Obtain new isotope samples from the west and north Svalbard shelves, to determine the water mass composition, and the origins and spatial modification of the coastal currents in this region.
4. Use the information on the spatial and temporal changes in freshwater inputs from different sources to improve their representations in the box models, and conduct trial runs for different fjordic systems.
5. Apply knowledge on freshwater components of coastal currents into analysis of numerical model output from Norwegian research groups.
Applicants should hold or expect to gain a first or upper-second class undergraduate degree or a masters degree in Physics, Mathematics, Oceanography, Meteorology, or any other numerate subject. The project will involve developing, running, and analysing output from simplified numerical models, and comparing these results with existing data. While no fieldwork is required, there will be an opportunity to obtain further samples on a research cruise around Svalbard during the project.
The successful student will be registered with the Scottish Association for Marine Science (SAMS), University of the Highlands and Islands (UHI), with the degree accredited by and awarded through the University of Aberdeen.
The NERC PhD Studentship is linked to the British Antarctic Survey Polar Oceans programme, which investigates the role of processes and changes both in the shelf sea and in open-ocean environments in both Polar Regions, to further our understanding of polar control of the Earth System (http://www.bas.ac.uk/bas_research/our_research/current/programmes/oceans/index.php). We envisage that the student will spend some of the studentship at SAMS in Oban, and some at BAS in Cambridge.
Salary: The studentship is expected to last 3.5 years from October 2013. Stipend for 2012/2013 was £13,590 p.a. For eligibility go to http://www.nerc.ac.uk/funding/available/postgrad/eligibility.asp
Applications should be addressed to Mike Meredith, including a covering letter, full CV and the e-mail addresses of two referees and sent to firstname.lastname@example.org Please quote reference number AP5.
Closing date for applications is 28th February 2013. It is intended that initial interviews will be held at BAS week commencing 18th March 2013.
For further details about the British Antarctic Survey please see: http://www.antarctica.ac.uk
For further details about the Scottish Association for Marine Science please see: http://www.sams.ac.uk
Please click on the links below for further information about careers and employment in the aquatic sciences.