Observing and modelling the Greenland ice sheet with CPOM

Author: Nicola Bortun

Observing and modelling the Greenland ice sheet with CPOM

Posted on by Nicola Bortun

Greenland is a fascinating and beautiful country, with a population of more than 50,000 people. It has long been a key area of focus for polar scientists, due to the importance of observing and modelling of changes to the Greenland ice sheet. This huge expanse of ice, the second largest land ice mass in the world, is more than 2000km in length, 1000km wide and at its thickest point is over 3km thick.

And this ice sheet is melting.

Melting ice sheets directly contribute water to the oceans, leading to sea level rise. This influx of cooler water also affects the ocean circulation, with implications for global weather patterns. Accurately tracking melting of the Greenland and Antarctic ice sheets is essential to ensure people all over the world can prepare for the effects of climate change.

As ice sheets are so huge they are incredibly difficult to fully measure in person. Satellite measurements are the only ways we can accurately measure these vast areas.

CPOM has provided assessments of the amount of ice stored in the Greenland and Antarctic ice sheets since 2018, via the IMBIE Project (Ice Sheet Mass Balance Intercomparison Exercise) which uses three decades of satellite data to assess the ice sheets. You can read their most recent report in Earth System Science Data from 2023, which estimates ice losses from these regions since 1992.

Another recent study from December 2024, led by CPOM PhD Researcher, Nitin Ravinder, and published in Geophysical Research Letters, showed that the Greenland ice sheet lost 2347 km3 of ice during the period since 2010 – which has contributed roughly ‘the amount of water stored in Africa’s Lake Victoria’ to the Earth’s oceans. Here’s an animation from Planetary Visions based on this study showing these changes in the Greenland ice sheet.

As sea level rise will affect many millions of people around the world, as well as the numerous at-risk species in coastal habitats, it’s vital that Governments and international bodies are able to plan for this rise. Computer modelling (simulations) is the only way we can accurately predict how the ice sheets might behave in the future.

CPOM provides UK National Capability research in ice sheet modelling, developing the BISICLES model.

BISICLES is a numerical model (simulation) that works with high resolution simulations around the margins of ice sheets (the grounding line), where interactions between the ice sheet and the ocean and atmosphere are the most complex. This is particularly useful when looking at the Greenland ice sheet.

Scientists from CPOM recently worked on combining this system as the ice sheet component within the UKESM (The UK Earth System Model), allowing us to better explore and understand the interactions between the ice sheets and the global ocean and atmospheric circulations (and providing evidence for IPCC reporting).

BISICLES has also been integrated into large international projects such as ISMIP (Ice Sheet Model Intercomparison Project) to help project future changes to global sea levels, something that is particularly difficult to predict beyond the end of the century with one model alone.

The behaviour of the Greenland ice sheet is particularly difficult to predict, as over recent years we have seen points where melting has been more rapid than anticipated, but also points where it has been less than expected. We need to continually hone and improve computer simulations (or models) that can accurately predict how these ice sheets might behave in a rapidly warming planet to account for the complexity of the interactions between the ice sheets and the atmosphere in these regions.

Understanding this part of the world is vital for understanding how we might protect the rest of the Earth in the years to come. By combining expertise in land ice Earth observation with modelling simulations, like BISICLES, CPOM is continuing to increase the accuracy of future projections of sea level rise and weather changes, leading from the melting of the Greenland ice sheet.

Image credit: Professor Andrew Shepherd

Ice Sheet Mass Balance – a groundbreaking scientific discovery

Posted on by Nicola Bortun

Before we had satellites, it was very difficult to assess and monitor the Earth’s ice. We only had data collected by scientists visiting the polar regions, and the areas we study are so vast it would be impossible to monitor them manually. However, since the launch of Earth Observation satellites like ESA’s ERS-1 and CryoSat missions, and NASA’s IceSat missions, our understanding of these complex regions has been transformed.

To mark the European Space Agency’s (ESA) 50th anniversary, they have created this brochure detailing 12 groundbreaking scientific discoveries that have been made possible thanks to the ESA Earth Observation programmes. One of the successes that ESA have highlighted is the Mass balance of the Greenland and Antarctic Ice Sheets as assessed by The IMBIE Team, led by CPOM.

IMBIE is an international collaboration of 100 polar scientists, supported by ESA and NASA, who are working to chart the sea level contribution of the polar ice sheets. In their latest assessment report (published in 2023), led by CPOM’s Inès Otosaka (Northumbria University), the team revealed that ice loss had accelerated during the 29-year record of satellite observations and that this accounted for a ‘significant’ increase in the global sea level.

ESA released this animation in 2023, based on the data from this report, showing Ice loss from Greenland and Antarctica. 

UK parliamentary inquiry into ‘The UK and the Antarctic Environment’. Here is what we had to say:

Posted on by Nicola Bortun

In December 2024, the Environmental Audit Committee revived their Sub-Committee on Polar Research’s inquiry into The UK and the Antarctic Environment, which had been launched the previous year under the former government.

This inquiry is exploring the impacts of climate change in Antarctica and the role that UK science can play in understanding these changes and protecting the region.

Parliamentary inquiries offer direct routes for academics to inform the government about relevant scientific findings, provide research-led advice and influence policy decisions. Having taken part in the original call for evidence, the UK Centre for Polar Observation and Modelling (CPOM) submitted a supplementary statement to summarise the information we provided in our initial written report and reiterate key advice. We highlighted, for example, that changes in the Antarctic will have global consequences for people and animals, that we will need to adapt to significant impacts from sea level rise in the coming years, and that the UK needs to commit to support for long-term international collaborations between modellers, climate scientists, and remote sensing specialists to ensure we are fully prepared for these changes.

We also added that, since the initial call, additional evidence of Antarctic sea ice decline has been observed, we highlighted the opportunity to improve observations through the United Nations Antarctica InSync programme, and also pointed to the requirement for governance of any future geoengineering schemes. You can read our report alongside other evidence on the Inquiry website: https://committees.parliament.uk/work/8689/the-uk-and-the-antarctic-environment-revived/publications/

For more information, you can watch CPOM’s Dr Inès Otosaka giving evidence in person for the initial inquiry (alongside other experts) on Parliament TV: https://parliamentlive.tv/event/index/01ec3440-450c-42de-970a-e6b762836d19

CPOM joins STEM Learning’s #POP24 Day

Posted on by Nicola Bortun

On Tuesday 12 November 2024, scientists from the UK Centre for Polar Observation and Modelling took part in STEM Learning’s Protecting our Planet Day 2024, a fantastic day of live-streamed sessions from experts on what is being done to protect our planet from space, and on Earth.

More than 150,000 people, including classrooms full of interested teachers and pupils, joined to learn more about climate change and how they can pursue a career in STEM.

The event was presented by the UK Space Education Office (ESERO-UK) at STEM Learning, and in collaboration with the European Space Agency and the UK Space Agency. 

The full listings of sessions are available on STEM Learning’s Youtube Page.

Watch Professor Andy Shepherd and former CPOM Researcher Dr Anne Braakmann-Folgmann talk about Protecting the Ice…

Watch Dr Sammie Buzzard talking about Protecting our Planet with Maths…

Watch Dr Inès Otosaka talking about Protecting our Planet with Technology…

ESA and NASA satellites deliver first joint picture of Greenland Ice Sheet melting

Posted on by Nicola Bortun

Story published by The European Space Agency

Global warming is driving the rapid melting of the Greenland Ice Sheet, contributing to global sea level rise and disrupting weather patterns worldwide. Because of this, precise measurements of its changing shape are of critical importance for adapting to climate change.

Now, scientists from the UK Centre for Polar Observation and Modelling have delivered the first measurements of the Greenland Ice Sheet’s changing shape using data from ESA’s CryoSat and NASA’s ICESat-2 ice missions.

Although both satellites carry altimeters as their primary sensor, they make use of different technologies to collect their measurements. CryoSat uses a radar system to determine Earth’s surface height, while ICESat-2 uses a laser system for the same task.

Although radar signals can pass through clouds, they also penetrate the ice sheet surface and have to be adjusted to compensate for this effect. Laser signals, on the other hand, reflect from the actual surface but cannot record when clouds are present. The missions are therefore highly complementary, and combining their measurements has been a holy grail for polar science.

A new study from scientists at the CPOM and published today in Geophysical Research Letters, shows that CryoSat and ICESat-2 measurements of Greenland Ice Sheet elevation change agree to within 3% of the changes taking place.

This confirms that both satellites can be combined to produce a more reliable estimate of ice loss than either could achieve alone. It also means that if one mission were to fail, the other could be relied upon to maintain our record of polar ice change.

Between 2010 and 2023, the Greenland Ice Sheet thinned by 1.2 m on average. However, much larger changes occurred across the ice sheet’s ablation zone where summer melting exceeds winter snowfall; there, the average thinning amounted to 6.4 m.

Image credit: Professor Andrew Shepherd (Northumbria University)

The most extreme thinning occurred at the ice sheets outlet glaciers. At Sermeq Kujalleq in west central Greenland (also known as Jakobshavn Isbræ), the peak thinning was 67 m, and Zachariae Isstrøm in the northeast the peak thinning was 75 m.

Altogether, the ice sheet shrank by 2347 cubic kilometres across the 13-year survey period – similar to the amount of water stored in Africa’s Lake Victoria. The biggest changes occurred in 2012 and 2019, when the ice sheet shrank by more than 400 cubic kilometres because of extreme melting in those years.

Greenland’s ice melting also has profound effects on global ocean circulation and weather patterns. These changes have far-reaching impacts on ecosystems and communities worldwide. The availability of accurate, up-to-date data on ice sheet changes will be critical in helping us to prepare for and adapt to the impacts of climate change.

“We are very excited to have discovered that CryoSat and ICESat-2 are in such close agreement,” says lead author and CPOM researcher Nitin Ravinder. “Their complementary nature provides a strong motivation to combine the data sets to produce improved estimates of ice sheet volume and mass changes. As ice sheet mass loss is a key contributor to global sea level rise, this is incredibly useful for the scientific community and policymakers.”

The study made use of four years of measurements from both missions, including those collected during the Cryo2ice campaign, a pioneering ESA-NASA partnership initiated in 2020. By adjusting CryoSat’s orbit to synchronise with ICESat-2, ESA enabled the near-simultaneous collection of radar and laser data over the same regions.

This alignment allows scientists to measure snow depth from space, offering unprecedented accuracy in tracking sea and land ice thickness.

Credit: ESA

Tommaso Parrinello, CryoSat Mission Manager at ESA, expressed optimism about the campaign’s impact: “CryoSat has provided an invaluable platform for understanding our planet’s ice coverage over the past 14 years, but by aligning our data with ICESat-2, we’ve opened new avenues for precision and insight.

CryoSat Image Credit: European Space Agency

“This collaboration represents an exciting step forward, not just in terms of technology but in how we can better serve scientists and policymakers who rely on our data to understand and mitigate climate impacts.”

“It is great to see that the data from ‘sister missions’ are providing a consistent picture of the changes going on in Greenland,” says Thorsten Markus, project scientist for the ICESat-2 mission at NASA.

“Understanding the similarities and differences between radar and lidar ice sheet height measurements allow us to fully exploit the complementary nature of those satellite missions. Studies like this are critical to put a comprehensive time series of the ICESat, CryoSat-2, ICESat-2, and, in the future, CRISTAL missions together.”

ESA’s CryoSat continues to be instrumental in our understanding of climate related changes in polar ice, working alongside NASA’s ICESat-2 to provide robust, accurate data on ice sheet changes. Together, these missions represent a significant step forward in monitoring polar ice loss and preparing for its global consequences.

For more information, contact the lead author: Nitin Ravinder (n.ravinder@northumbria.ac.uk)

Planning for rapid and irreversible change in the future: CPOM awarded funding to investigate critical climate tipping points in Antarctica

Posted on by Nicola Bortun

The UK Centre for Polar Observation and Modelling (CPOM) has been awarded over £400,000 by the European Space Agency (ESA) to investigate tipping points in the Earth’s icy regions (the cryosphere), with a focus on the Antarctic.

Climate tipping points are critical thresholds that if crossed, can lead to rapid and irreversible changes in the climate system with dramatic consequences for our society. Crossing these points in the cryosphere has the potential to lead to much faster sea level rise as well as trigger other tipping points in the climate system, therefore it is of vital importance that scientists assess and attempt to understand where and when these tipping points might be crossed. This knowledge will help governments better prepare for the consequences of climate warming.

CPOM Co-Director for Science, Dr Inès Otosaka (Northumbria University) will be leading the ‘CryoTipping’ project with a team of Earth Observation experts from ESA’s Antarctic CCI+ Project and ice sheet modelling experts from Northumbria’s Future of Ice on Earth Peak of Research Excellence.

The research will build on datasets developed by ESA’s Antarctic CCI+ Project, and will combine Earth Observation and numerical modelling to detect marine ice sheet instability in the Amundsen Sea Sector, with a focus on Thwaites glacier.

Dr Otosaka said:

“Satellite observations have shown that the ice sheets have been melting more rapidly than previously thought whilst numerical models have demonstrated their sensitivity to future changes in their surrounding atmosphere and ocean. By combining state-of-the-art satellite observations and numerical modelling techniques, this exciting project will further our understanding of the trigger of instability mechanisms in Antarctica.”

Exploring the potential of using satellite data to detect early warning signs of marine ice sheet instability, the CryoTipping project will be the first to contrast present-day retreat rates of the Thwaites glacier measured from satellite data against those modelled over the past 20,000 years.

Dr Anna Maria Trofaier, Cryosphere Scientist at ESA (European Space Agency) said:

“That Thwaites Glacier is extremely vulnerable to climate change is known. The worry is that ongoing changes could result in a switch to a new state of the West Antarctic Ice Sheet with crucial consequences for sea level rise. If we want to understand the state of this tipping element we need to combine models with observations, and the European Space Agency’s satellite Earth Observation data are ideally placed to support this new project and its important work.”

The team aims to develop a new method to detect these tipping points by feeding satellite observations of grounding line location (where glaciers and ice shelves start to float), ice velocity, and surface elevation changes to an ice sheet model, investigating the onset and potential irreversibility of the retreat of Thwaites glacier over the coming centuries.

The project, funded by ESA and due to commence in early 2025, is led by CPOM (based at Northumbria University), in partnership with ice sheet modelling experts from Northumbria’s Future of Ice on Earth Peak of Research Excellence, PIK (Potsdam Institute for Climate Impact Research) and MPI-GEA (Max Planck Institute of Geoanthropology), and Earth Observation experts from ENVEO IT GmbH and DLR German Aerospace Center.

CPOM is a partnership of six universities and the British Antarctic Survey (BAS), based at Northumbria University, primarily funded by the National Environment Research Council (NERC) to provide national capability in observation and modelling of the processes that occur in the Polar regions of the Earth.

CPOM uses satellite observations to monitor change in the Polar regions and numerical models to better predict how their ice and oceans might evolve in the future. By providing long-term capabilities to the scientific community and leading international assessments, CPOM helps global policymakers plan for the effects of climate change and sea level rise.

Image credit: Andrew Shepherd

Recent research from CPOM and BAS shows record low Antarctic sea ice is four times more likely with climate change

Posted on by Nicola Bortun

Last year (2023) winter Antarctic sea ice measured at its lowest since 1978 when satellite records began.

Using the CMIP6 data set (climate dataset), British Antarctic Survey (BAS) and Centre for Polar Observation and Modelling (CPOM) researchers investigated this sea ice loss, including data from 18 different climate models in order to understand the likelihood of this level of sea ice loss, and its relationship to climate change.

The research, led by Rachel Diamond (Cambridge University/BAS) shows that this type of event would be a one- in-a-2000-year event without climate change. Using the most up-to-date models showed that this type of decline in sea is four times more likely (a one-in-a-500 year event), suggesting that climate change played a significant role, however this type of event still remains unlikely.

The paper by Diamond, R., et al was published on Monday 20 May 2024 in the journal Geophysical Research Letters.

CPOM Iceland Fieldwork Adventure

Posted on by Nicola Bortun

In September 2024 a team of CPOM PhD Researchers and staff used drones to study proglacial lakes in Iceland.

While there, they captured their work on camera so we can experience it too.

You can also read about this campaign in more detail on the European Space Agency (ESA) Blog.

Recent research using ISMIP6 Model Ensemble

Posted on by Nicola Bortun

Ice sheet models (scientific simulations which aim to predict future behaviour of ice sheets) often disagree on the timing and magnitude of sea level rise up until 2300. For example, projections of Antarctica’s contribution to sea level rise beyond 2100 remain highly uncertain due to processes such as Ice Sheet and Ice Cliff instability which could cause Antarctic melting to contribute more rapidly to sea level rise.

The Coupled Model Intercomparison Project Phase 6 (CMIP6) is an international effort using different climate models to better understand how the Earth’s climate system responds to various factors. ISMIP6 (Ice Sheet Model Intercomparison Project for CMIP6), co-led by CPOM, is the part of CMIP6 project that examines the ice sheets, aiming to improve predictions of their future contribution to sea level rise, which is critical to assess the impact of melting ice on sea level rise, oceans currents, and weather patterns. By pulling together a range of different models, ISMIP6 supports the scientific community by producing more accurate, robust, multi-century projections of sea level rise and quantifying their associated uncertainties.

The most recent report using the ISMIP6 Model ensemble was released on Wednesday 4 September) in the AGU Earth’s Future journal. The new study (Seroussi et al). investigates the behaviour of the Antarctic Ice Sheet until 2300 using an ensemble of 16 ice-flow models and forcing from global climate models. This is the first multi-century, multi-model projections of the Antarctic Ice Sheet evolution and shows that ice flow models are relatively consistent in predicting a limited Antarctic sea-level rise up until 2100. However, beyond the end of this century, Antarctica’s ice losses increase rapidly thereafter with the choice of ice flow model and different potential influential factors such as carbon emissions (known as climate forcing scenarios) becoming sources of uncertainty.

This model ensemble shows that, under high carbon emission scenarios, some simulations show high levels of ice retreat after 2100 with potential sea level rise of up to 1.7m in 2200 and 4.4 m by 2300. In particular, key regions in West Antarctica, including the Bungenstock Ice Rise, the Siple Coast and the Amundsen Sea sector are predicted to undergo rapid retreat. Results saw strong variations between models on the onset of retreat but good agreement on the pattern of retreat.

In addition to the choice of ice sheet model, this study also highlights the importance of the emission scenario, as ice losses under both low and high emissions remain similar during the 21st century, the two scenarios produce significantly varied results post 2100. This highlights the importance of reducing emissions for the future stability of the Antarctic Ice Sheet as well as the importance of further work on developing and improving accurate and robust models of ice shelf retreat and potential collapse beyond 2100 so that policy makers and scientists can make decisions today which will protect the future of Antarctica beyond tomorrow.

Find out more about the 6th phase of the Coupled Model Intercomparison Project (CMIP6)

New £8.4M investment continues support for long-term polar science, co-led by the British Antarctic Survey (BAS) and UK’s Centre for Polar Observation and Modelling (CPOM)

Posted on by Nicola Bortun

£8.4M has been awarded to the British Antarctic Survey and the Centre for Polar Observation and Modelling to deliver the next 5 years of their long-term polar science activities. The UK Polar Research Expertise for Science and Society (PRESCIENT) programme provides UK national capability (science, such as ongoing datasets and models, which underpins wider scientific research) to understand the impacts of environmental stressors, such as rising global temperatures on polar marine ecosystems. PRESCIENT will also measure and predict polar ice sheet contributions to global sea level rise and extend and improve measurements of changes to polar sea ice.

Announced today the funding is part of £101 million investment by the Natural Environment Research Council, part of UK Research and Innovation, in the UK’s network of leading environmental science research centres to support large-scale environmental observations, modelling and analysis, and research capabilities through innovations in platforms, sensors and data science. These data are crucial for managing natural resources, biodiversity, human health and building our understanding of and resilience to environmental hazards and climate change. It underpins science across the UK’s environmental research sector and supports critical scientific advice to government.

PRESCIENT will also aid the BAS transition to low carbon science delivery, by progressing delivery of airborne science using remotely piloted autonomous systems (RPAS), while delivering independent scientific advice and support to a range of stakeholders in government, business, and wider society, ensuring that our scientific activities and expertise is available to support solutions.

National capability is research funding which, unlike shorter term projects, can span decades and provides ongoing support for large-scale, complex scientific projects of national significance, informing strategic needs and decision-making of the country. Using techniques such as satellite altimetry to study ice motion and the polar oceans, CPOM incorporate the results into models used across the polar research community. CPOM’s data sets and models have been developed and maintained for almost a quarter of a century, and the long-term maintenance of this capability helps provide robust understanding and insights of the cryosphere.

CPOM also contribute to a range of interdisciplinary multi-centre National Capability research projects including CANARI, BIOPOLE, and TerraFIRMA, which have been running since 2022, offering satellite derived estimates of aspects of the cryosphere (such as ice thickness, floe size and sea height), as well as developing advanced simulations. The longevity of our datasets, and the accuracy of our models mean we have a broader view of past and possible future changes. By contributing to projects such as the previous multi-centre National Capability project UKESM (UK Earth System Model), integrating ice sheet model and advanced sea ice physics into the system, we can produce robust projections of ice sheet instability and Arctic sea ice loss, thereby informing sea level rise predictions. Our PRESCIENT programme with BAS continues this work into 2029.

This funding has been awarded from NERC’s National Capability Single Centre Science initiative, one of the UK’s largest environmental science investment programmes.

Read more on the British Antarctic Survey (BAS) website.