FUTURE OF ICE ON EARTH

PROPHET (PROcesses, drivers, Prediction: modeling the History and Evolution of Thwaites)

PROPHET is a joints US and UK project funded by NSF and NERC. It is a part of the International Thwaites Glacier Collaboration project.   Northumbria University is leading UK operations of PROPHET, part of the International Thwaites Glacier Collaboration (ITGC). This is a major interdisciplinary project seeking to answer important questions about one of the fastest changing areas of Antarctica. 

The ITGC is the largest collaboration between the UK and USA in Antarctica for 70 years. It has been granted £20 million in funding jointly by the UK Natural Environment Research Council (NERC) and the US National Science Foundation (NSF) and is taking place over a 5 year period. 

There are eight components of the ITGC, of which PROPHET is one of two modelling studies. There are also four observational studies focusing on key dynamical processes, and two looking at the historical context of the glacier and surrounding ocean. The data collected in these observational projects will feed into the modelling work of PROPHET. 

The aim of PROPHET is to predict near-future changes to Thwaites Glacier using state-of-the-art ice and ocean modelling informed by accurate and extensive observational data. PROPHET aims to improve the representation of important processes of glacier dynamics within ice flow models and use the improved models to forecast the future evolution of the glacier and its contribution to sea level rise. 

Funder: The PROPHET project, a component of the International Thwaites Glacier Collaboration (ITGC), is jointly funded by NSF and NERC under grant agreement NE/S006745/1 

Funds awarded to Northumbria: £774k 

Duration: 1 August 2018 to 31 July 2024 

Staff involved: Jan De Rydt, Hilmar Gudmundsson 

PIs: Hilmar Gudmundsson (UK) and Mathieu Morlighem (Dartmouth College, US) 

Post Doctorial Research Assistants: Sebastian Rosier, Jowan Barnes, Camilla Schelpe

PROTECT: Projecting sea-level rise: From Ice Sheets to Local Implications

The overarching scientific objective of PROTECT is to assess and project changes in the land-based cryosphere, with fully quantified uncertainties, in order to produce robust global, regional and local projections of SLR on a range of timescales.

The project will place particular emphasis on the low-probability, high impact that are of greatest interest to coastal planning stakeholders. A novelty in PROTECT is the strong interaction between these stakeholders and the sea-level scientists, ranging from glaciologists to coastal impact specialists, to identify relevant risks and opportunities from global to local scales and enhance European competitiveness in the provision of climate services.  

Northumbria is involved in several of the work packages relating to ice and ocean simulations of the Antarctic Ice Sheet and the Southern Ocean. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement 869304. 

Funds awarded to Northumbria: £445k 

Duration: 2020 to 28 Feb 2025  

Staff involved: Adrian Jenkins, Hilmar Gudmundsson

PIs: Adrian Jenkins and Hilmar Gudmundsson 

Post Doctorial Research Assistants: Ole Richter and Jaysankar Pillai

A new mechanistic framework for modelling rift processes in Antarctic ice shelves 

The key goal of this project is to provide a new numerical and observational framework for understanding and including ice shelf rift processes in numerical ice-flow models. This is a collaborative research project between Northumbria University and MIT. The project is funded thought a joint NSFgeo/NERC grant NE/V0133191

Funder: NSFgeo and NERC 

Funds awarded to Northumbria: £270k. 

Duration: Sept 2021 – Sept 2024 

PIs: Hilmar Gudmundsson (UK) and Brent Minchew (MIT, US) 

Post Doctorial Research Assistants: Tom Mitcham (from Sept 2021 to Dec 2022) and Camilla Shelpe.

OCEAN-ICE: Ocean-Cryosphere Exchanges in Antarctica: Impacts on Climate and the Earth System

OCEAN:ICE assesses the impacts of key Antarctic Ice Sheet and Southern Ocean processes on Planet Earth, via their influence on sea level rise, deep water formation, ocean circulation and climate. The EU and UKRI funded OCEAN:ICE project brings together 17 European research centres and numerous international collaborators to improve assessments of sea level rise and the impact on the European and global climate from the melting ice sheets.

Northumbria University is involved in several of the project’s objectives involving improving the representation of the Antarctic Ice Sheet in coupled climate models and assessing how freshwater inputs from the ice sheet affect the dynamics of the Southern Ocean.

OCEAN:ICE seeks to understand the impacts of polar (mainly Antarctic) ice sheet and Southern Ocean processes on Planet Earth, via their influence on sea level rise, deep water formation, ocean circulation and climate. It combines new and novel observations around the Antarctic Ice Sheet and Southern Ocean with cutting edge modelling and model development; crucially including improving and running coupled ice sheet-climate models to observe the role of feedbacks between the cryosphere and ocean on global climate to 2300 and beyond.

New observations, including campaigns beneath ‘warm’ and ‘cold’ ice shelves, and existing observations will be assimilated into improved ice sheet boundary conditions and forcing. These will be used to produce new estimates of recent past and present ice sheet melt (including Greenland).

These improved ice sheet models will be used alongside rigorous numerical approaches to constraining uncertainty in future ice sheet surface runoff, basal melt and iceberg calving under various forcing scenarios and comparing coupled with uncoupled ice sheet-ocean interactions. They will also assess the ‘deep uncertainty’ associated with processes such as marine ice cliff instability to constrain future estimate of sea level rise.  

Funder: OCEAN:ICE is co-funded by the European Union, Horizon Europe Funding Programme for research and innovation under grant agreement Nr. 101060452 and by UK Research and Innovation 

Funds awarded to Northumbria: £475k. 

Duration: November 2022 to October 2026 

PIs: Jan De Rydt and Hilmar Gudmundsson. 

Post Doctorial Research Assistants: Qing Qin

PRECISE: Prediction of Climate Change and Effect of Mitigating Solutions

This is a collaboration between Northumbria University and Niels Bohr Institute in Denmark and Danish Meteorological Institute.

The aim is to provide new assessments of the future of the Greenland and Antarctic Ice Sheets. This involves including new and novel physics of fracture, damage and calving into our ice sheet models and to create a new framework for coupled ice-ocean and ice-atmosphere models using machine learning emulators.  

This is a six-year project with very ambitious goals of delivering a step-change in our ability to predict changes in those large ice masses by considering them as part of a fully integrated coupled ice/ocean/atmospheric system. Of particular interest is the possibility of strong non-linear interactions between surface mass balance and surface elevation which might give rise to a self-enhancing periods of sustained ice loss. 

Funder: Novo Nordisk Foundation 

Funds awarded to Northumbria: £1,4M. 

Duration: January 2024 to January 2030 

PI: Hilmar Gudmundsson at Northumbria, and overall project lead is Prof. Christina Hvidberg at the Niels Bohr Institute, Copenhagen.  

Post Doctorial Research Assistants: Three postdocs to be appointed.

DECADES: Drivers of Oceanic Change in the Amundsen Sea

Thinning of the Antarctic Ice Sheet is most prominent in the Amundsen Sea sector, where it has been observed to spread inland from the coast, and to affect neighbouring outflow glaciers in a similar way.  Those facts demonstrate that some change in ocean-driven melting of the glacier termini has been the trigger of change, leading to a widespread belief that warming of the ocean waters, driven ultimately by global warming, is responsible. 

However, observations of ocean temperature in the Amundsen Sea suggest a more complex history.  The records start in 1994, and include only a few observations prior to 2009, but suggest cycles between warm and cool conditions occurring over decadal periods.  

This project, a collaboration between 7 UK institutions, led by Northumbria, involves the applications new techniques to fill the gaps in the record of ocean temperature change in the Amundsen Sea.  A robotic submarine will over-winter beneath the pack ice, periodically measuring the properties and strength of the currents carrying warm water towards the ice.  Those measurements will be complemented by fixed instruments that record continuously at selected locations and seal-borne sensors that will record the depth of the warm water wherever and whenever the seals dive below the surface to feed. 

The aim is to relate those detailed observations of what is happening below the sea surface to changes in the height of the sea surface that can be detected by satellites.  That will allow the exploitation of the satellite records collected over three decades to infer past changes in the sub-surface ocean, and thus to confirm the timing and magnitude of recent warm and cool cycles and relate them directly to the records of ice sheet thinning. 

 To extend that knowledge of Amundsen Sea temperatures beyond the satellite era, numerical models of the ocean circulation in the region will be used to identify the patterns of atmospheric forcing that have been responsible for the observed changes in temperature. 

Reconstructions of past atmospheric circulation will then be used to generate a history of the key atmospheric changes and to investigate how those changes in the regional atmospheric circulation relate to global scale atmospheric change.  Those results will provide the longer-term perspective that is needed to address the questions of what past conditions initiated the current phase of ice sheet thinning and what the future might hold. 

Funder: NERC 

Funds awarded to Northumbria: £1.4M 

Duration: 1st July 2020 to 30th June 2025 (to be extended as a result of fieldwork delays) 

PI: Adrian Jenkins 

Post Doctorial Research Assistants: To be appointed. 

Ocean Forcing of Ice Sheet Evolution Beyond West Antarctica

Although ocean-forced thinning of the ice sheets is most widespread and dramatic in West Antarctica, a large sector of the East Antarctic Ice Sheet (EAIS) is grounded below sea level and is thus potentially vulnerable to the same process of ice shelf thinning, grounding line retreat and ice stream acceleration. 

Furthermore, analogous ocean forcing to that in West Antarctica could influence the marine-based sector of the EAIS.  In both regions the Antarctic Circumpolar Current brings warm Circumpolar Deep Water (CDW) close to the continental slope.  

In addition, half of the sea level contribution of the Greenland Ice Sheet (GIS) has come from acceleration in the flow of a number of major outlet glaciers that drain ice from the interior of the ice sheet directly into the ocean.  Analogous processes bring warm Atlantic Water (AW) to the margins of the GIS, where only relatively shallow seabed sills can protect the glacier termini from the off-shore ocean heat.  The prevalence of surface melting over the GIS in summer supplies subglacial drainage networks that introduce freshwater at depth and stimulate distinctive spatial and temporal patterns of melting. 

However, our knowledge of the oceanography of the continental shelves and fjords and of the waters that circulate beneath the floating ice shelves and interact with the tidewater glaciers is presently insufficient to understand the oceanic processes that are driving change in the ice sheets.  Our ability to project the future behaviour of the ice sheets is severely limited as a result. 

To address that deficiency, this project involves the development and application of numerical models of ocean circulation near and beneath the ice shelves and the use the computed melt rates to force numerical models of ice sheet flow.  The aim is to investigate the response of key outlet glaciers to a range of climate forcing. 

A detailed understanding of ocean circulation and melting beneath the glaciers, and the role of inverted channels cut into the base of the ice shelves, will generate insight into ocean-ice interactions that will be relevant to many sites in Greenland and Antarctica, and will advance our developing knowledge of ice sheet discharge and its future effect on sea-level rise. 

Funder: NERC 

Funds awarded to Northumbria: £517k 

Duration: 1st August 2020 to 31st July 2024 

PI: Adrian Jenkins 

Post Doctorial Research Assistants: Alethea Mountford, Jaysankar Pillai

Coupled Evolution of Ice Shelf and Ocean in the Amundsen Sea Sector of Antarctica

It is now well understood that the process of ice loss from Antarctica has been initiated by thinning of the floating ice shelves that form at the margins of the ice sheet.  Warmer ocean waters lead to more rapid melting of the ice shelves, they thin and the flow of ice off the land accelerates. 

However, that acceleration of the flow delivers more ice to the ice shelves, and they should therefore start to grow, or at least thin less rapidly, unless the ocean heat delivery continues to grow. Until recently it was assumed that the ocean was indeed steadily warming, but as our record of ocean observations has lengthened, we have seen decadal cycles of warming and cooling.  Why then should the ice shelves continue to thin? 

The answer must lie in the way in which the thinning of the ice shelves themselves affects the melt rate, but it not clear why the change in the ice should increase rather than decrease the melt. However, in this case observation of the key processes is exceptionally difficult because they take place beneath 100s or even 1000s of metres of ice. 

That is the challenge we will address with this project, by sending an autonomous submarine beneath the ice to make the critical measurements of the ocean, including the temperature of the water and the currents.  Those direct observations of the ocean beneath the ice will allow us to verify that the ocean models we use to simulate the processes are correct, or to improve them if they are not. 

 This will not be the first time such measurements have been made, but the new observations will differ in two important respects from the very few that have been made in the past.  Some will be repeats of earlier measurements, so we will have observations from before and after a significant change in the extent of the ice shelf.  Thus, we can directly answer the question of what change in the ocean circulation accompanied the change in shape of the ice cover. 

Other observations will target regions where the ice was grounded until recently.  Because radar signals penetrate ice, but not seawater, we are able to map the topography only when the ice rests on the land and not when it is afloat.  Thus, we paradoxically know the geometry of newly formed ocean cavities with much greater accuracy than we do the cavities that have been there since humans first explored the south polar regions.  Our ability to understand the links between cavity geometry and ocean circulation is therefore enhanced in the newly opened cavities that are among the targets of our field campaign. 

Funder: NERC 

Funds awarded to Northumbria: £485k 

Duration: 1st July 2026 to 30th June 2029 

PI: Adrian Jenkins

Post Doctorial Research Assistants: To be appointed.

Connecting past, present and future: hindcast and forecast of Antarctic ice loss between 2000 and 2300

Satellite observations provide glaciologists with increasingly complete and frequent maps of ice velocity and thickness changes of the Antarctic and Greenland ice sheets. For nearly three decades, satellites have helped us identify the physical processes that underlie contemporary rates of mass loss from both ice sheets, and Earth observations have been key in quantifying the ice sheets’ present-day contribution to global sea level rise.

However, the fundamental issue remains how these changes will evolve in a warming world, and what their global impact will be on sea level and the global climate. To provide reliable forecasts of ice sheet changes, and connect the past, present and future, we need validated models with robust uncertainty quantification. 

In parallel with the satellite revolution, ice sheet models have advanced significantly over the last decade. Confidence in their ability to produce numerically robust projections for complex geometries and climatic conditions has greatly improved, and essential dynamical interactions with the ocean and atmosphere can now be included. Yet, little effort has been put into comparing hindcasts of past changes from modern ice flow models with the rich, 30-year repository of satellite data.

A model validation exercise of this type is both timely and critical: it needs the long time series of observations and sophisticated models that are now available, and it forms a prerequisite for reliable forecasts of the ice sheets’ impact on global sea levels in the 21st century and beyond. 

In light of this important deficiency and the need for robust, century-scale forecasts, this fellowship focuses on three distinct challenges: (1) the initial value problem of predicting the evolution of the ice sheets given an uncertain estimate of its present-day state, (2) the structural problem of unknown/uncertain physical parameters, and (3) the boundary value problem of assessing future changes in the state of the Ice Sheet due to uncertain future climate forcing.

The project team will use the coupled ice-ocean model Úa-MITgcm to study some fo the most vulnerable regions of the Antarctica and Greenland ice sheets. They will use data assimilation techniques, perturbed physics ensemble techniques and model emulators to systematically sample uncertain model physics (basal sliding, ice rheology, calving, etc) and assess their impact on forecasts within a probabilistic framework.

This will allow a comprehensive validation of the coupled ice-ocean model and identification of the physical parameter space that is consistent with observations. Estimates of atmospheric and ocean conditions from global climate simulations for a range of future climate scenarios will then be used in combination with perturbed physics ensembles to obtain an improved estimate of ice loss from Antarctica and Greenland between now and 2300, with a robust quantification of model errors and consistent with the observational record. 

Funder: UKRI 

Funds awarded to Northumbria: £1.23M 

Duration: 1st September 2022 to 31th August 2026 

PI: Jan De Rydt

Post Doctorial Research Assistants: Brad Reed and Jo Zanker 

Greenland Ice Sheet and sea-level response under climate change from AD 1600 to 2100 

Project: With sea-level change being high on the global political agenda, there is currently a tremendous scientific and societal need to improve predictions of Greenland Ice Sheet melt and mass loss over the coming decades.

This project will produce estimates of past and future Greenland Ice Sheet surface mass balance and dynamic ice changes using cutting-edge climate and ice sheet models and datasets and mathematical evaluation of the uncertainties in these.

The main aim of the proposed work is to produce a full mass balance history (i.e. how much ice has been gained or lost) of the Greenland Ice Sheet from 1600 to 2021 AD and Greenland Ice Sheet mass balance projections to 2100 AD, and to assess the resulting contribution to historical and future global sea-level.

The reconstruction of ice thickness changes of the Greenland Ice Sheet back to 1600 AD, for a period where such records are largely lacking, will quadruple the length of the existing record and form the basis of an improved understanding of the ice sheet's history and sensitivity to climate change, such as Greenland’s transition through the Little Ice Age to present day.

This project is a collaborative project involving Northumbria University, University of Lincoln, University of Nottingham and Durham University 

Funder: UKRI 

Funds awarded to Northumbria: £351k 

Duration:  1st Feb 2024 to 31st Jan 2027 

PI: Leanne Wake and Co-I Hilmar Gudmundsson  

Post Doctorial Research Assistants: Emily Hill

 RASP: Re-thinking Antarctic Sea-level Projections

Project: One major consequence of global warming is the rising of sea levels that threaten coastal communities, ecosystems and industries worldwide. In the recent 2021 report from the International Panel on Climate Change summarising the physical understanding of the Earth System, it is emphasised that future ice loss of the Antarctic Ice Sheet is the most uncertain of the major components.

In this project, we propose a new approach to better understand and constrain the uncertainty for the Antarctic component. One reason why the future evolution of the Antarctic Ice Sheet is so uncertain is a gap in the scientific understanding, and thus representation in computer models, of how the surrounding Southern Ocean melts the Antarctic Ice Sheet. Warmer ocean waters are found offshore of the Antarctic continent in the deeper, open ocean.

If, and how, those warm water masses access the continental shelf is dependent on a complex interaction of regional climate drivers such as winds, precipitation and air temperatures. But how important these different climate drivers will be for ice loss in the different Antarctic regions in the future, is unclear.

We here propose to answer this question using a numerical model that represents the relevant Southern Ocean processes. Using this novel understanding, we can then bridge the gap between the far-field, open ocean and the vicinity of the ice sheet. We will use a numerical ice flow model to make Antarctic future projections.

This model represents how the changes in the atmosphere and ocean-driven melting affect the ice flow in Antarctica, and thereby lead to sea-level rise. Thereby, we can fill the knowledge gap in the physical links between the Southern Ocean and the Antarctic Ice Sheet, and how much each link will contribute to sea-level rise over the coming decades to centuries. 

Funder: NERC 

Funds awarded to Northumbria: £806k 

Duration:  1st April 2024 to 31st March 2028 

PIs:  Christopher Bull. Co-Is Ronja Reese, Adrian Jenkins, Robin Smith (University of Reading) and Hélène Seroussi (Dartmouth College, USA) 

Post Doctorial Research Assistants: Two postdocs to be appointed. 

Chemistry and Biology under Low Flow Hydrologic Conditions Beneath the Greenland Ice Sheet Revealed through Naturally Emerging Subglacial Water 

Project: Weathering is an important process that releases nutrients that are essential for life from rocks and minerals in the Earth's surface. This project seeks to understand the effect of large glaciers on weathering processes beneath the Greenland Ice Sheet and the consequences for life.

During summer, nutrients and other products are flushed out of the Greenland Ice Sheet with water from melting ice. While these products have been sampled in spring and summer, it is not known how weathering processes are different during winter.

In this project, researchers will sample the seasonal ice that forms in front of two of Greenland's glacial outlets, Isunnguata Sermia and Leverett Glacier, during the freezing months to assess the chemistry and microbiology processes that reflect wintertime conditions beneath the ice sheet periods when input of fresh meltwater is minimal.

These samples will increase knowledge of winter conditions under the Greenland Ice Sheet and help better understand the interior portions of the ice sheet which are largely inaccessible. Such information will help in assessing past conditions, when colder atmospheric conditions resulted in minimal meltwater input through the ice sheet and to the glacial bed. These analyses will inform understanding of the role of glaciers on earth's nutrient cycles presently, under past ice age conditions, and in a future deglaciating world. 

Funder: NERC & NSF 

Funds awarded to Northumbria: £300k 

Duration:  1st March 2022 to 1st March 2025 

PIs: Joseph Graly, Kathy Licht (Indiana University, USA), Trinity Hamilton (University of Minnesota, USA).
Co-I: Kate Winter 

Post Doctoral Research Assistants: Rebecca McCerery

ISOTIPIC: Interacting ice Sheet and Ocean Tipping - Indicators, Processes, Impacts and Challenges

Project: The aim of is to understand the processes controlling key tipping points (TPs) associated with the oceans and ice sheets and assess their potential impacts on society and the global Earth system. Those tipping elements are related to the Antarctic and the Greenland ice sheets and involve the marine ice-sheet instability and the surface-elevation feedback on ice caps.

We will also investigate the stability of the Atlantic Ocean Meridional Overturning and possible shifts in the thermal state of the Southern Ocean. The project involves several partners including the British Antarctic Survey, the National Oceanography Centre, and the Universities of Reading, Southampton, and Liverpool. This is funded as a part of NERC highlight topic on the Risks and Impacts of Climate Tipping Points. 

Funder: NERC  

Funds awarded to Northumbria: £480k. 

Duration: 1st Feb 2024 – 31st Jan 2028. 

PI and Co-Is: Hilmar Gudmundsson, Ronja Reese, Sainan Sun.