- Global glacier mass change dat...
Global glacier mass change data now available from CryoSat
20 Sep 2023
Measuring glacier mass changes from space is more accurate and comprehensive thanks to the CryoTEMPO-EOLIS CryoSat swath data products, which now cover glaciers worldwide. A new Baseline 2 product release boasts significant improvements in data quality, so we can observe glacier changes in greater detail than ever before.
Glaciers all over the world are melting at ever-faster rates. Glacier behaviour is complex, and different glaciers can display very different responses to a changing environment.
ESA’s ice mission, CryoSat, has been monitoring glaciers and ice sheets for over 13 years. The Earth Explorer is the only radar altimetry satellite currently capable of monitoring the change of all land ice regions on Earth. It has provided one of the longest continuous satellite records of polar ice in existence.
CryoTEMPO-EOLIS, which uses CryoSat’s SARIn mode and novel swath processing technique, provides highly detailed (temporal and spatial) elevation changes over the Greenland and Antarctic ice sheets, and now glaciers worldwide.
The glaciers covered include those of Antarctica, Greenland, Iceland, Svalbard, Alaska, the Southern Andes, High Mountain Asia and the Russian Arctic.
Amongst the Baseline 2 improvements, elevation change time series for CryoTEMPO-EOLIS gridded products can be visualised and downloaded using a new time series tool.
All the CryoTEMPO-EOLIS products and new Baseline 2 features, developed by Earthwave and the University of Edinburgh with support and funding from ESA, can be accessed via cs2eo.org.
“We’re delighted to extend our high-resolution data to glaciers worldwide,” said Carolyn Michael, Earth observation data scientist at Earthwave. “It’s now easier than ever to study long term changes to glaciers, and to understand the complex response of glaciers to a changing climate.”
More information, including tutorials, can be found on the CryoTEMPO-EOLIS website.
A paper detailing the background work, which showed glaciers worldwide had lost 2% of their total volume between 2010 and 2020, was published in Geophysical Research Letters.
“CryoSat is known in the cryosphere community as a gift that keeps on giving,” said Alessandro Di Bella, CryoSat mission geophysicist. “CryoTEMPO-EOLIS brings its data to life, allowing us to observe glacier changes with great precision. It’s an invaluable resource.”
The following examples highlight how the latest CryoTEMPO-EOLIS Baseline 2 products perceive diverse glacier changes.
A fluctuating glacier system on the Antarctic Peninsula
Since the collapse of the Wordie Ice Shelf between 1966-89, the ice front position at the Airy–Rotz–Seller–Fleming glacier system has continued to retreat, with much higher thinning, than surrounding glaciers.
CryoTEMPO EOLIS provides a clear picture of changes in the behaviour of the glacier over time thanks to CryoSat’s monthly repeat rate data, which show that thinning has fluctuated over the past 13 years. This is influenced by large-scale changes in the El Niño Southern Oscillation and the Southern Annular Mode.
Altitude-driven glacier changes on the Vatnajökull ice cap, Iceland
In contrast to the Airy–Rotz–Seller–Fleming glacier system, glacier thinning of Síðujökull and Skaftárjökull on the Vatnajökull ice cap is largely driven by altitude.
At the lowest altitudes (< 1000 m) the mean change rate is -2.2 m per year, whereas at higher altitudes (> 1500 m) ice thickness increases by 0.4 m per year on average. Seasonal cycles are clear at moderate elevations (1000 m to 1500 m) with accumulation in winter and loss during the summer.
Same ice cap, different glacier changes
Different behaviours can also be observed on the same ice cap. The Academy of Sciences ice cap, for example, displays areas of both mass gain and mass loss. In the north and northwest of the ice cap, the drainage basins appear, for the most part, to be thickening slightly. However, the south and southeast show areas that are dynamically thinning.
A significant portion of the south and southeast of the ice cap has a bed elevation below sea level. Here, ocean warming has caused increased submarine melting of tidewater glaciers.
The north of the ice cap is land terminating, therefore not directly influenced by the ocean. Instead, this sector responds to changes in atmospheric conditions.