Predicting future methane release from the seabed due to Arctic warming and sea ice retreat

Project Rationale :
Methane hydrate is an ice-like substance that is stable at high pressures and low temperatures and is present beneath the seabed on continental margins. Methane is a potent greenhouse gas; its release may have contributed to climate change in the geological record. Arctic ocean temperatures have been rising rapidly during the last decades and are predicted to rise over the next century. Methane release may be linked to hydrate dissociation in response to ocean warming. Until now, attempts to understand this process have been limited to using simplified coarse resolution climate models, or to focus on small regions. This project aims to extend a more sophisticated high-resolution modelling approach across the entire Arctic, specifically to the Arctic shelves and examine erosion of the subsea and coastal permafrost as a potential source for methane. The project will address the impact of sea ice decline on the erosion rates and ocean warming, aiming to quantify the amount of methane release from the subsurface over the next 100 years and to help develop understanding of the processes governing hydrate dissociation and impacts on climate. A further aim is to develop a methane sub-model for incorporation into climate prediction models.

Methodology :
The project will use state-of-the-art ocean-sea ice-atmosphere model based on the European modelling framework NEMO and developed jointly by NOC and the Met Office for the 6th IPCC Assessment Report. The model will be combined with advanced analysis of the thermo-hydro-chemical response of hydrates in the subsurface to the ocean warming. The student will use output from the climate model simulations spanning the period 1860-2100 to assess present and future changes in sea water temperatures and sea-floor temperatures in the Arctic Ocean. Over the historical period, the climate models will be compared to available observations. The model will be applied to a set of case studies employing different warming scenarios in order to understand probable range of the future methane releases. The student will develop a transfer function that can be applied to predict the timing and volume of methane release in response to ocean warming and will apply the transfer function approach to the entire Arctic region and inform future IPCC assessments.

Training:
The INSPIRE DTP programme provides comprehensive personal and professional development training alongside extensive opportunities for students to expand their multi-disciplinary outlook through interactions with a wide network of academic, research and industrial/policy partners. The student will be registered at the University of Southampton and hosted at National Oceanography Centre Southampton.
The student will join the UK’s most active large-scale ocean modelling and marine geophysics groups and will have opportunities to participate in marine research at sea. He/she will have access to a range of high-level courses taught at NOC, and state-of-the art modelling, including UK HPC. He/she will receive training in the analysis of ocean models and in modelling for subsurface fluid flow. The student will join an international group of researchers working in Arctic Oceanography and methane and will develop strong communication and team-working skills. This will equip the student for future employment in Marine Sciences.