Researchers have successfully made the initial assessments of changes in the thickness of the Greenland Ice Sheet by utilizing data from ESA and NASA ice satellite missions. As the Greenland Ice Sheet continues to melt and flow more rapidly due to global warming, it contributes to rising sea levels and disrupts weather patterns worldwide. Hence, accurate measurements of its evolving shape are crucial for monitoring and addressing the impacts of climate change.
Researchers from Northumbria University are part of a global team that has used satellite data to observe transformations in the thickness of the Greenland Ice Sheet.
Climate change is accelerating the melting of the Ice Sheet, which leads to higher sea levels and alters weather patterns across the globe.
Thus, precise measurements of its changes are vital for monitoring and adapting to the impacts of climate change.
Scientists have recently released the first measurements regarding changes in the thickness of the Greenland Ice Sheet, using data from CryoSat-2 and ICESat-2—the ESA and NASA satellite missions.
Both satellites are equipped with altimeters, but they utilize different technologies to gather their data.
CryoSat-2 employs a radar system to measure the height of the Earth’s surface, whereas ICESat-2 utilizes a laser system for the same purpose.
While radar signals can penetrate through clouds, they also go below the surface of the ice, requiring adjustments to account for this interaction.
In contrast, laser signals reflect from the immediate surface but become ineffective in cloudy conditions.
The missions thus complement each other, and merging their data has become a significant goal for polar research.
A recent study conducted by researchers at the UK Centre for Polar Observation and Modelling (CPOM) at Northumbria University, published in Geophysical Research Letters, shows that the elevation change measurements from CryoSat-2 and ICESat-2 align within 3%.
This confirms that combining the data from both satellites yields a more accurate estimate of ice loss compared to using either satellite alone. Additionally, in the event that one mission fails, the other can still provide continuity in monitoring polar ice changes.
From 2010 to 2023, the Greenland Ice Sheet experienced an average thinning of 1.2 meters, but in the ablation zone, the thinning was more than five times greater, reaching an average of 6.4 meters.
The most significant thinning took place at the outlet glaciers of the ice sheet, many of which are accelerating.
The highest thinning recorded was 67 meters at Sermeq Kujalleq (also known as Jakobshavn Isbræ) in central-western Greenland, and 75 meters at Zachariae Isstrøm in the northeast.
Over the 13-year survey period, the ice sheet lost a total of 2,347 cubic kilometers—enough to fill Lake Victoria in Africa.
Notable declines occurred during the exceptionally hot summers of 2012 and 2019, when the ice sheet lost over 400 cubic kilometers of volume each year.
The melting of Greenland’s ice has implications for global ocean circulation and alters weather patterns, resulting in significant consequences for ecosystems and communities worldwide.
Having access to accurate and timely information regarding changes in the ice sheet will be essential for helping us prepare for and adapt to the consequences of climate change.
Nitin Ravinder, the lead author and CPOM researcher, stated: “We are thrilled to find that CryoSat-2 and ICESat-2 have such a close agreement.”
“Their complementary characteristics motivate us to combine the datasets for more refined estimates of ice sheet volume and mass changes. Since the loss of ice sheet mass is a major factor in rising global sea levels, this information is immensely beneficial for both the scientific community and policymakers.”
The study utilized data from four years of measurements from both missions, including information gathered during the Cryo2ice campaign—a collaborative effort by ESA and NASA initiated in 2020.
By adjusting CryoSat-2’s orbit to sync with ICESat-2, ESA enabled nearly simultaneous collection of radar and laser data across the same areas.
This coordination allows researchers to assess snow depth from space, significantly improving the precision in measuring land and sea ice thickness.
Tommaso Parrinello, CryoSat Mission Manager at ESA, expressed optimism about this campaign’s contributions:
“CryoSat has been an invaluable resource for understanding the planet’s ice coverage for the past 14 years. By aligning our data with ICESat-2, we’ve uncovered new opportunities for precision and insights.”
“This collaboration marks an exciting advancement, not just technologically but also in enhancing our support for scientists and policymakers who depend on our data to comprehend and address climate impacts.”
Thorsten Markus, project scientist for the ICESat-2 mission at NASA, remarked: “It’s encouraging to see that data from these ‘sister missions’ present a consistent overview of the changes taking place in Greenland.”
“Understanding the similarities and differences in height measurements of ice sheets using radar and lidar enables us to fully utilize the complementary aspects of these satellite missions.”
“Studies like this are vital for compiling a comprehensive timeline of the ICESat, CryoSat-2, ICESat-2, and future CRISTAL missions.”
ESA’s CryoSat-2 remains crucial for enhancing our insights into climate-related changes in polar ice, working in conjunction with NASA’s ICESat-2 to deliver reliable data on alterations to the ice sheet.
Together, these missions represent a considerable advancement in monitoring polar ice depletion and preparing for the global repercussions.
CPOM is a consortium of six universities and the British Antarctic Survey (BAS), based at Northumbria University, primarily funded by the National Environment Research Council (NERC) to enhance national capabilities in observing and modeling the processes affecting the Polar regions of Earth.
CPOM leverages satellite observations to track changes in the Polar regions and employs numerical models to better predict future changes in ice and ocean conditions.
By offering long-term capabilities to the scientific community and leading global assessments, CPOM aids policymakers worldwide in planning for the impacts of climate change and rising sea levels.
