In 2024, we were very lucky to be able to catch up with women working in the field of Earth observation and modelling from across the world at the ESA/NASA Cryo2ice conference in Iceland.
Ahead of International Women’s Day 2025 coming up this Saturday, we gathered some of the perspectives shared with us on the importance of studying and understanding the Earth, what it’s like working in this area of science and why it’s important to share scientific understanding with the world- as well as encouraging words for women and girls thinking of pursuing a career in science.as well as encouraging words for women and girls thinking of pursuing a career in science.
Thank you to our interviewees for taking part in this video: CPOM Principal Investigator: Sea Ice Earth Observation, Rosemary Willatt (UCL), Anny Cazenave (LEGOS), CPOM Director for Knowledge Exchange, Sammie Buzzard (Northumbria University), Liza Wilson (University of Iceland/Fulbright Commission Iceland), Rachel Tilling (NASA), Bryony Freer (Scripps Institute of Oceanography) and Helen Fricker (Scripps Institute of Oceanography).
A special thanks must also go to the ESA and NASA Cryo2ice team, who facilitated many of the interviews included in this video.
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 Project) 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.
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.
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.
Satellites can now measure the thickness of Arctic sea ice in the summer months for the first time, thanks to a new study involving UCL researchers and CPOM associates, Professor Julienne Stroeve and Dr Michel Tsamados.
Until now, satellites could only measure sea ice thickness between October and March, when the ice and snow are cold and dry. In the warmer months, melt ponds on top of the ice floes confused the instruments, which could not be used to distinguish between melted ice on an ice floe and the ocean.
In the new study, published in the journal Nature, researchers used an artificial intelligence technique to correct this problem, in which an algorithm was trained on thousands of simulations of satellite data to reliably distinguish between melt ponds and the ocean.
Earth’s ice is melting 65% faster than the 1990s. But without satellites, we would be blind to the true status of global climate change.
CPOM Scientist, Dr Tom Slater’s (University of Leeds) recent article ‘All Eyes on Earth’ written for a Royal Museums Greenwich exhibition can be found here:
As of January 2022, ESA has started releasing new CryoSat-2 Thematic Products, dedicated to five distinct areas: Sea Ice, Land Ice, Polar Oceans, Coastal Oceans and Inland Waters.
Developed within the frame of the CryoSat-2 Thematic Products (Cryo-TEMPO) activity, these products benefit from agile and state-of-the-art altimetry processing workflows, which utilise dedicated processing for each domain and optimise data fidelity across each thematic surface.
The simplified format and inclusion of fully traceable uncertainties are designed to make CryoSat-2 datasets accessible to new communities of scientific and service users, who traditionally may have lacked the technical expertise required to utilise previous products. To ensure this, a group of thematic non-altimetry experts has been integral in testing and providing feedback on the prototype datasets during the product design stage.
The current product release represents the culmination of Phase 1 of the Cryo-TEMPO activities, which began in October 2020. The consortium is now working on algorithm evolutions for the next product release, which is scheduled for the beginning of 2023.
The new Cryo-TEMPO product files are distributed via ESA’s CryoSat-2 Science Server and cover the full duration of the CryoSat-2 mission, from 2010 to the present day.
Interested users can access the associated documentation on ESA’s Earth Online website. Further information can also be found on the project website.
