Arctic Sea Ice ‘More Resilient’ Than Thought

Arctic sea ice volumes in the autumn of 2014 are above the average set over the last five years and sharply up on the lows seen in 2011 and 2012, according to the latest satellite data.

Click to enlarge. Sea ice thickness October-November 2010. Courtesy ESA.

Data from the European Space Agency (ESA) CryoSat-2 satellite to be presented to the American Geophysical Union’s Fall Meeting in San Francisco later today (Monday 15 December, 2014) will show Arctic sea ice volumes in October and November 2014 averaging 10,200km3 – slightly down on the 10,900km3 reported in 2013 but sharply up on the lows seen in 2011 and 2012.

This is the second year in a row where a relatively cool Arctic summer has led to less sea ice melting than has been typical during the summers of recent years and this has resulted in thicker and older ice surviving into the autumn and winter during both 2013 and 2014.

The team of researchers from University College London (UCL) who are presenting the CryoSat-2 data to the AGU Fall Meeting state in the abstract of their presentation that their data indicates “the Arctic sea ice pack may be more resilient than has been previously considered”.

The autumn 2014 volume is the second-highest since satellite measurements of Arctic sea ice thickness began in 2010, and the data shows that “the five-year average is relatively stable”, according to ESA.

This news comes as the US National Snow and Ice Data Center (NSIDC) reported that Arctic sea ice extent – the area of ocean covered by sea ice – in November was “fairly average”.

It is a combination of sea ice extent and sea ice thickness which gives rise to sea ice volume. CryoSat was designed to measure sea-ice thickness across the entire Arctic Ocean using radars, and this has allowed scientists to monitor the overall change in Arctic sea ice volume accurately over the last five years.

However, researchers are careful to caution that this apparent stability shown in the satellite data does not mean there has been a recovery in Arctic sea ice. A news release from ESA quotes Professor Andrew Shepherd from UCL and the University of Leeds as saying: “We must to take care when computing long-term trends as this CryoSat assessment is short when compared to other climate records”.

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