Scientists stunned by Arctic warmth and disappearing ice

Scientists who watch ice for a living are stunned by what they’re measuring. Temperatures have soared above freezing this winter in the Arctic. In the dark of Arctic night. Arctic temperatures have been as much as 50 degrees warmer than normal in some locations.

Disappearing ice

This year’s disappearance of ice in mid-winter in the Arctic appears to be unprecedented in the modern climate record. And the longer term downward trend of older, and thicker, multi-year ice is unmistakable.

Capital Weather Gang’s Jason Samenow has an eye-opening write up on the increasingly frequent Arctic warm surges in recent years. I spoke with Jason today about this unusual pattern in the Arctic.

Here are some select clips from Jason’s piece.

Such extreme warm intrusions in the Arctic, once rare, are becoming more routine, research has shown. A study published last July found that since 1980, these events are becoming more frequent, longer-lasting and more intense.

“Previously this was not common,” said lead author of the study Robert Graham, from the Norwegian Polar Institute, in an email. “It happened in four years between 1980-2010, but has now occurred in four out of the last five winters.”

Scientists were shocked in recent days to discover open water north of Greenland, an area normally covered by old, very thick ice. “This has me more worried than the warm temps in the Arctic right now,” tweeted Mike MacFerrin, an ice sheet specialist at the University of Colorado.

Such warm water is appearing to have an effect on air temperatures. At the north tip of Greenland, about 400 miles to the south of the North Pole, the weather station Cape Morris Jesup has logged a record-crushing 61 hours above freezing so far this calendar year. The previous record, dating to 1980, was 16 hours through the end of April in 2011, according to Robert Rohde, a physicist at Berkeley Earth, a nonprofit that conducts temperature analysis. At one point, the temperature was as high as 43 degrees (6.1 degrees Celsius).

Arctic open water, in winter

Some Arctic locations that almost always have thick mid-winter sea ice now show open water. Mashable’s Andrew Freedman adds this perspective.

“I think it’s fair to say that this event is unprecedented in our record — both in terms of the magnitude and (for Kap Morris Jesup at least) the duration,” said Ruth Mottram, a climate scientist at the Danish Meteorological Institute, in a Twitter message, using the Danish spelling for Cape Morris Jessup. “The warm event at KMJ is not record breaking in terms of the highest ever recorded temperature in February, but that event in 2011 was very short-lived compared to what we have seen this year…,” she said. “A prolonged period like this has definitely not been seen before.”

She said some of the warmth in northern Greenland was likely due to downsloping winds known as Foehn winds, which can increase air temperatures. But that doesn’t explain the warmth in the Arctic overall, when compared to average February conditions. “But when we look at the high Arctic overall, the temperature record since 1958 has never seen a warm spike of this magnitude in February,” she said. “Having said that, the last few winters have seen similar events of very warm air coming in to the Arctic , though not nearly as large in magnitude,” Mottram said.

Minnesota lakes showing less winter ice too

We’ve reported many times on the multiple signs of climate warming in Minnesota . This data set from realclimate.org confirms the trend since the 1970s of significantly less lake ice here in Minnesota and around the world.

Minnesotan Lakes

The most comprehensive (and up-to-date) set of “ice out” data for lakes is, unsurprisingly perhaps, from the Dept. of Natural Resources in Minnesota. Data (sometimes patchy) goes back in places to the 19th Century. The earliest data is for Lake Pepin starting in 1843. By 1900, there are a further 6 lakes with data: Clear, Christmas, Minnetonka, Osakis, Sagatagan, and Shields.

Historical ice out for Lake Osakis via Minnesota DNR.