British researchers have used a new forecasting method to determine that this year’s melt will be about the same or slightly more than last year, but nowhere near the record arctic sea ice melt set in 2012.
This new method of predicting arctic sea ice melt was outlined in Nature Climate Change.
Last year, the arctic sea ice extent melted to 5.10 million square kilometers, according to the National Snow and Ice Data Center (NSIDC) at the University of Colorado in Boulder.
Back in 2012, the size of the sea ice extent melted down to a record low of 3.41 million square kilometers.
This year’s ice melt is expected to about 18 percent higher than the average ice melt was between 1981 and 2010.
The new forecasting method developed by polar climate scientists at the UK’s University of Reading allows researchers to take ice melt data from early in the summer melting season, which usually begins in March, to make predictions of total arctic sea ice melt, which normally reaches its peak in mid-September.
The British scientists expect the arctic sea ice extent to be about 5.4 million square kilometers by the end of the 2014 summer melt season, but the final sea ice extent measurement could be anywhere between 4.9 and 5.9 million square kilometers.
This new forecasting method centers on analyzing both the size and coverage of melt ponds that form on the sea ice surface during the melting season.
The melted sea ice doesn’t flow into the open sea right away, instead forming into melt ponds, which are pools of melted iced water that can be found among and atop chunks of remaining ice chunks. The researchers said that these melt ponds can last for a number of months during the melt season.
The researchers found that the number of these melt ponds in May was relatively low and had not developed as quickly as they did in previous years.
“Melt ponds are crucial to the speed of the annual ice melt, as the dark water on the surface absorbs more energy from the sun than the white ice, which reflects much of it back into space. But until now, there has not been a physically-based melt pond model,” said Daniel Feltham, who leads the NERC Centre for Polar Observation and Modelling team at the University of Reading, in a press-release.
“Compared to the last five years, the Arctic has had colder air temperatures and slightly thicker ice in the relevant areas, meaning the melt ponds have not developed as quickly in 2014,” he added.
If the team’s prediction turns out to be accurate and there are two consecutive years where the sea ice extent didn’t melt as much as it did in 2012, it may indicate that the decline is temporarily in one of these more stable periods, according to Ed Hawkins, from the National Center for Atmospheric Science (NCAS) at the University of Reading.
“The latest climate models suggest that Arctic sea ice will dwindle as the 21st century progresses. If greenhouse gas emissions continue to rise at their current rate it’s likely that the Arctic Ocean will be completely ice-free in around 40 years’ time,” said Hawkins. “However, during this long-term downwards trend we expect to see periods of several years when the sea-ice melts very rapidly, and similar periods of relatively stable ice levels – the decline will not occur smoothly.”
The researchers say their new forecasting system could be of great use to industries like tourism, shipping and oil production, which are all looking for new passageways through the Arctic.