One of Greenland’s glaciers is losing five billion tonnes of ice a year to the ocean, according to researchers. While these new findings may be disturbing, they are reinforced by a concerted effort to map changes in ice sheets with different sensors from space agencies around the world.
It is estimated that the entire Zachariae Isstrom glacier in north-east Greenland holds enough water to raise global sea levels by more than 46 cm. Jeremie Mouginot, University of California Irvine, said “The shape and dynamics of Zachariae Isstrom have changed dramatically over the last few years. The glacier is now breaking up and calving high volumes of icebergs into the ocean, which will result in rising sea levels for decades to come.”
As one of the first regions to experience and visibly demonstrate the effects of climate change, the Arctic serves as an indicator for change in the rest of the world. It is therefore critical that polar ice is monitored comprehensively and in a sustained manner.
The value of international organizations joining forces to understand aspects of our planet such as this cannot be underestimated. These current findings are a prime example of how different satellite observations and measurements from aerial surveys by various space agencies are being used. The Polar Space Task Group has been coordinating the collection of radar data over Greenland and Antarctica and European Space Agency (ESA) radar observations going back to the ERS and Envisat satellites through to Sentinel-1A were used in the new study.
Scientists have determined that the bottom of Zachariae Isstrom is being rapidly eroded by warmer ocean water mixed with growing amounts of meltwater from the ice sheet surface. Jeremie Mouginot said “Ocean warming has likely played a major role in triggering the glacier’s retreat, but we need more oceanographic observations in this critical sector of Greenland to determine its future”.
ESA’s Climate Change Initiative treats the Greenland ice sheet as an “essential climate variable”. The initiative has assembled comprehensive datasets for scientists to understand exactly how sensitive regions are changing and to help predict how the rest of the world will be affected. These data are now being extended by the Sentinel-1 mission, which adds several terabytes of data daily.
ESA’s Mark Drinkwater said “Without a routine monitoring capability, it is not possible to provide the critical data for ESA’s Climate Change Initiative to assess the impact that the rapidly changing face of Greenland has on sea level. It is clear that combinations of multi-agency radar together with Copernicus Sentinel-1A now fulfil a critical role in this monitoring task.”