Starting in 2014, Sentinel 1 observations now form the first continuous map of surface flow velocities across both the Greenland and Antarctic ice sheets at continental scale.

The new dataset, described in a study in the journal Remote Sensing of Environment, is derived from advanced processing of synthetic aperture radar data from Sentinel 1 and is part of an ESA curated collection marking the mission's first decade.

The associated special issue highlights how long term, high resolution satellite records underpin applications ranging from ice sheet monitoring to broader Earth observation services.

Over Antarctica, Sentinel 1 data averaged from 2014 to 2024 show ice streams moving between about 1 and 15 meters per day, with coverage spanning the Antarctic Peninsula, Alexander Island, and much of both the West and East Antarctic ice sheets at revisit intervals of six or twelve days along most coasts.

On the West Antarctic Ice Sheet, the Pine Island Glacier stands out, where ice flow at the grounding line increased from roughly 10.6 meters per day to 12.7 meters per day during the study period, while neighboring glaciers also accelerated as ocean driven thinning of floating ice shelves and a retreating grounding line altered ice dynamics.

Around Greenland, the analysis reveals rapid outlet flows, generally up to about 15 meters per day, discharging ice from the interior to the ocean along many sectors of the ice sheet margin.

On the west coast, Sermeq Kujalleq, or Jakobshavn Glacier, remains one of the world's fastest outlet glaciers, with surface velocities at times reaching about 50 meters per day.

The North East Greenland Ice Stream is also clearly defined, starting far inland at the ice divide marked by a dark blue band of near stagnant ice in central Greenland, and then feeding fast flowing ice towards the coast.

The new velocity products offer spatial detail down to roughly 200 to 250 meters and can resolve motion over time spans from under a week to more than 10 years, enabling both short term event detection and long term trend analysis.

Because velocity directly controls how much ice and meltwater reach the sea, these data feed critical estimates of present and future sea level rise and help document processes such as calving events and structural damage within glacier and ice shelf systems.

Improved tracking of ice motion strengthens efforts to predict how ice sheets and glaciers will evolve, how much they will contribute to sea level, and how these changes will interact with the wider climate system.

Lead author Jan Wuite of ENVEO IT described the change in polar monitoring delivered by the mission, noting, "Before the launch of Sentinel-1, the absence of consistent SAR observations over polar glaciers and ice sheets posed a major barrier to long-term climate records.

Today, the resulting velocity maps offer an extraordinary view of ice-sheet dynamics, providing a reliable and essential data record for understanding polar regions in a rapidly changing global climate."

Within the Copernicus Climate Change Service for the cryosphere domain, led by ENVEO, annual ice velocity products for Greenland and Antarctica are now produced operationally.

Joaquin Munoz Sabater, the responsible scientist at the European Centre for Medium Range Weather Forecasts for the C3S cryosphere service, stated, "The ice velocity time series for Antarctica and Greenland are an essential component of the C3S Cryosphere Service and a key contribution to monitoring the impacts of global warming in some of the world's most sensitive regions."

Since launch of the first satellite in 2014, Sentinel 1 has markedly expanded polar Earth observation capabilities with a 12 meter long C band SAR instrument that supplies high resolution imagery for routine monitoring and emergency response, operating through cloud, smoke and polar darkness.

Nuno Miranda, ESA's Sentinel 1 Mission Manager, explained, "Before Sentinel-1, generating such results required combining data from multiple sensors over several years.

With Sentinel-1, these results are now produced annually and, thanks to advances in science, even monthly.

This breakthrough enables monitoring of these remote areas with unprecedented temporal resolution.

It is an essential tool as 2025 marks another record-breaking year of Arctic warming, where rapid changes demand closer and more frequent observation."

The mission now supports large scale, dense and continuous time series of polar ice velocity for climate research and extends the use of interferometric SAR techniques for ice motion retrieval to wider areas than previously possible.

Sentinel 1's systematic polar acquisition strategy maintains continuous coverage over the main sectors of the Greenland and Antarctic ice sheets and other ice masses, ensuring that changes in flow regimes are captured over time.

With the launch of Sentinel 1D at the end of 2025, the constellation's capacity to revisit Greenland and Antarctica every six days or less is restored, rebuilding and even improving on the coverage available before the failure of Sentinel 1B.

Using the extensive SAR archive, the study team developed algorithms to produce detailed maps and dense time series of glacier and ice sheet velocity now spanning more than a decade.

Their results underline Sentinel 1's ability to monitor glacier and ice sheet flow comprehensively, supplying key inputs for models of ice dynamics and climate.

According to the World Meteorological Organization, global sea level rise mainly reflects the thermal expansion of warming ocean water and the addition of meltwater from land based ice.

The Greenland and Antarctic ice sheets hold enough frozen water to raise sea level dramatically if they were to melt completely, and ongoing mass loss is already influencing low lying coastal zones worldwide, including regions prone to flooding and storm surges.

By establishing a consistent, continent wide baseline of ice motion under current conditions, the new dataset provides a reference against which any future acceleration or slowdown in flow can be detected.

Looking ahead, Sentinel 1 data will be combined with SAR observations from the upcoming Copernicus expansion mission ROSE L to sustain systematic coverage of Greenland and Antarctica in the coming decades.

ENVEO IT CEO and study co author Thomas Nagler commented, "Sentinel-1 revolutionised our view of polar ice sheets by providing continuous, weather-independent radar measurements that reveal ice motion in unprecedented detail, transforming ice flow from a sparse snapshot into a dynamic, measurable process.

Building on this legacy, the integration of Sentinel-1 with the upcoming ROSE-L mission will further improve ice-flow observations, enabling more accurate and stable monitoring of ice-sheet dynamics."

Research Report: Sentinel-1: Advances in Remote Sensing After a Decade in Space

Related Links
Copernicus Climate Change Service
Beyond the Ice Age