New tool for predicting sea ice extent could boost Arctic development
A new study has demonstrated that the extent of meltwater ponds early in the year is a better predictor of minimum sea ice extent for that year than any other method. This could be big news for industries looking to reliably penetrate higher into the Arctic.
Every spring in the Arctic Ocean, the breakup of sea ice is preceded by the formation of meltwater ponds on top of the ice. Aside from visually representing global warming for calendars and reports, these beautiful meltwater ponds may have a valuable role to play in helping scientists predict the coming year’s minimum ice cover.
That could be big news for oil and gas and shipping companies eager for any accurate forecast of troublesome sea ice.
A new study in Nature Climate Change showed that while the Arctic sea ice has been shrinking in the summer, the size of the ponds on the ice has been growing proportionately. Measuring their size proved to be an effective tool for predicting how much or how little ice there would be in that year’s September minimum.
“We were surprised at how clear the link between this and late summer sea-ice extent is,” said lead author David Schröder in an interview with Phys.org.
This is no accident. The meltwater ponds actually play a major role in promoting the melting of the ice. Ponds cause the surface of the ice to absorb 20 percent more sunlight. So the water sitting on top of the ice warms the surrounding ice, causing a feedback loop and melting the ice faster.
In September 1996, when ice was at its highest level since satellites started recording sea ice extent in 1979, the ponds had covered just one tenth of the ice surface the previous July. In 2012, the meltwater ponds covered three times the area. That same year, we saw the lowest sea ice extent since monitoring began.
In fact, the meltwater ponds interfere with sea ice in two ways: a separate study in Geophysical Research Abstracts showed that the ponds also prevent the regrowth of sea ice in the winter by about one and a half months.
This is the first time meltwater ponds have been seriously incorporated into climate models – with major impact.
The study on refreezing rates showed that one fifth less sea ice formed when the ponds were taken into account.
Industrial opportunities and environmental apprehensions
Sea ice is a major consideration for industries trying to operate in the seasonally frozen ocean. There is a short window of opportunity for operations dictated by the absence of ice, so knowing when and how extensive that window will be could be a crucial advantage.
But not everyone is pleased to know that industry has another tool at their disposal to make work in the Arctic easier. This week, 44 Greenpeace activists were arrested in Rotterdam while protesting the first shipment of oil from the Gazprom’s Prirazlomnoye platform in the Eastern Barents Sea. The NGO has been protesting oil development in the Arctic for years, with high-profile events like the one in Rotterdam intended to slow development in that sensitive ecosystem.
Nils Boisen, the Arctic and northern areas advisor for World Wildlife Fund Norway, is pleased to hear of a new way to help shipping through Arctic waters proceed more safely. Plus, he adds, “it’s always good to have better methods to be able to model climate issues.”
But as for the oil and gas industry, which has been pushing its operations north against resistance from environmental groups, Boisen cautions that more information is not necessarily better. The industry is currently limited to drilling at the ice edge. Being able to predict where that ice edge will occur each year could push oil companies to move closer to the edge, a boundary on which a thriving ecosystem depends.
“A lot of the activities that they would like to conduct in the vicinity of the ice edge would have very detrimental effects on the ice edge ecology,” he says.
For now, however, the predictive ability of the meltwater ponds is limited to an overall sea ice extent: it can’t predict which regions will have more or less ice, only how much ice there will be in total. But the study opens the door to tighter predictions of the melting Arctic - for better or for worse.