PhD Project Overview

The overall aim of this PhD project is to investigate the drivers of variability in fjord water circulation, and the biological and physical consequences in a changing climate, using Cumberland Bay, South Georgia as a case study. Cumberland Bay is chosen as a study area for two main reasons. Firstly, the glaciers that terminate at the head of each arm have shown markedly different rates of retreat over the past century, aiding a strong comparative study of ocean forcing on glacier dynamics. Secondly, Cumberland Bay is an important spawning area for commercially fished mackerel icefish, which have seen significant reduction in annual catch in recent years. A high-resolution numerical model is developed using the Nucleus for European Modelling of the Ocean (NEMO) framework, and important forcing factors contributing to the circulation regime and the transport of heat to the glacier termini, such as winds and freshwater runoff, are assessed. An Individual Based Model (IBM) will then be used with the modelled flow fields to examine variability in retention of mackerel icefish larvae in the bay.

Project Objectives

• The first objective is to use a combination of observations and numerical modelling to elucidate the ocean circulation in Cumberland Bay and to determine the dominating physical drivers of variability;
• The second objective is to investigate how the circulation regime couples with associated glacier dynamics, the drivers of variability is glacier behaviour and expected responses in a changing climate;
• The third objective is to investigate how the circulation regime impacts biological activity in and around Cumberland Bay, specifically the recruitment and retention of fish larvae and krill.

Highlights 2020- 2021

• Completion of first year progression review (July 2020)
• Organised, hosted and chaired first virtual BAS student symposium Oct 2020
• Presented at the Challenger Society Ocean Modelling Conference (Sep 2020)
• Winner of Best Student Poster Presentation at the Antarctic Science Conference (April 2021)
• Joined BAS Net-Zero Communications and Awareness group as the student/early career researcher representative (April 2021)
• Successfully implemented baseline Cumberland Bay model with NEMO4.0.6 on ARCHER2 (super-computer)