An analysis of data from the European Space Agency's (ESA) CryoSat satellite shows that ice loss in the Antarctic is increasing at an exponential rate. It is estimated that the polar region now loses 159 billion tonnes of ice each year, with the worst instances of degradation located in the Western area of the Amundsen Sea.
The CryoSat satellite has been designed to take precise measurements of Earth's polar regions in an attempt to further understand how climate change is affecting these remote, yet vital, areas of our planet. The satellite is equipped with a Synthetic Aperture Interferometric Radar Altimeter (SIRAL), an instrument used to measure ice sheet elevation with a high degree of accuracy. SIRAL collects these readings by sending pulses (at an interval of around 50 microseconds) down to the surface, then collecting echoes of those pulses to determine the elevation of the ice sheets.
The UK-based Centre for Polar Observation and Modelling analyzed data collected over three years (by nearly continuous surveillance) from CryoSat, to create the world's first comprehensive assessment of elevation change in the Antarctic ice sheets. Results of the analysis found that ice loss in the polar region was 31 percent greater than that of the previous period of observation (from 2005-2011), with substantial thinning of the ice in the Amundsen Sea area of West Antarctica.
“Although we are fortunate to now have, in CryoSat, a routine capability to monitor the polar ice sheets, the increased thinning we have detected in West Antarctica is a worrying development,” states Prof. Andrew Shepherd, leader of the study. He continues, “It adds concrete evidence that dramatic changes are under way in this part of our planet. The challenge is to use this evidence to test and improve the predictive skill of climate models.”
The implications of these findings have the potential to be devastating in the long term, as ice loss standing as a leading contributor to rising sea levels. A significant increase in the global sea level has the potential to put coastal cities, such as Venice, Italy, at serious risk. ESA's researchers estimate that the loss of ice over the last three years alone has been substantial enough to raise the global sea-level by around 0.45 mm (.018 in) every year.
The findings of the UK Centre for Polar Observation and Modelling are available in the journal Geophysical Research Letters.