Snow in Greenland is melting — in winter

By Tom Yulsman | February 18, 2013 9:38 am

This Greenland cumulative melt days map shows the total number of days that surface melting has occurred for the year to date. (Image: National Snow and Ice Data Center Greenland Ice Sheet Today)

Update: I’ve been in touch with Ted Scambos of NSIDC. He corrected me on one fact that I misunderstood, and he added some new information about the significance of this event. See below. (I’ve also changed the headline.)

As the map above shows, some portions of Greenland’s ice sheet have experienced melting at the surface for more than 30 days since the first of the year.

And at least through the end of last week, the melting, as revealed by satellite data from the Defense Meteorological Satellite Program, had been continuing.

It’s not just wet snow. What’s being observed is wet snow. Even so, it is “real melting,” Ted Scambos, Senior Research Scientist with the National Snow and Ice Data, told me in an email message on Sunday afternoon. “Air temperatures along the southeastern coast for the period Feb 10 – 15 are running 2 to 6 C above normal. Nuuk, the capital, on the very southern west coast, is currently just a couple of degrees below freezing.”

Here is additional clarification I received from Scambos this morning:

The main message is that a short period of melting during the day will trip our melt detection algorithm and count as a day. Overall, this is a bit unusual — a warm spell — but I would downplay its exceptional nature at this point.

That said, it may herald more melting to come. In his email this morning, Scambos told me that “it may be the early start to another very high melt year, but we would have a better insight on that by May or so.”

For an NSIDC graph showing how the extent of melting so far this year compares to the long-term average, click here.

Update: Since Scambos wrote to me this morning, he emailed me back in the afternoon with some additional information. He noted that all of Greenland, not just the southeast coast, has been 2 to 6 degrees C warmer than the 30-year mean. And he also said this:

Is it a warm winter in Greenland? Yes, very warm. Incredibly warm? Worth writing home about? Not sure, but it is not the biggest anomaly in the Northern Hemisphere. That title goes to Svalbard: 10 to 12 C above normal since December.

In January, scientists published research showing that over the past 20 years, areas on the west side of Greenland have warmed in winter by more than 10 degrees C. In summer, warming has amounted to 2 to 4 degrees C.

The researchers found that the east side of Greenland had not warmed up as much during those two decades. Do the overall warm conditions in Greenland so far this year, and the melting seen on the southeast coast, suggest that something new is happening? Based on what Ted Scambos has told me today, I think the fair answer is that it is just too soon to tell.

This year’s winter thaw follows a record-setting summer melt season in 2012. From the NSIDC’s recently launched Greenland Ice Sheet Today web site:

Greenland’s surface melting in 2012 was intense, far in excess of any earlier year in the satellite record since 1979. In July 2012, a very unusual weather event occurred. For a few days, 97% of the entire ice sheet indicated surface melting.

For several decades now, the Arctic has been warming twice as fast as any other region on Earth — one of the clearest symptoms of human-caused global warming. And it has been contributing more to sea level rise than Antarctica has.

In research published last November, scientists reached something of a consensus on what the warming has been doing to the polar ice sheets. Here’s Richard Kerr’s summary (subscription required) in the journal Science:

By the new reckoning, the Greenland ice sheet lost 263±30 billion tons of ice per year from 2005 to 2010. Overall, Antarctica lost about 81 billion tons per year in the same period; the huge East Antarctic portion of the ice sheet registered a small gain, more than offset by losses in West Antarctica and the adjacent Antarctic Peninsula. Since 1992, the two ice sheets lost enough ice to raise sea level by about 0.6 millimeters per year on average, out of the observed 3 millimeters per year. (Most of the rest of the sea level rise came from melting mountain glaciers and from the expansion of seawater due to warming.)

A glacier flowing off the Greenland ice sheet, as seen on a flight from Oslo to New York in late January. (Photo: copyright Tom Yulsman)

I’ll be keeping an eye on what’s happening in Greenland, so check back for updates. The Arctic Oscillation is currently in a negative phase, and this typically brings warmer than usual weather to at least parts of Greenland. So we may see even more melting. We’ll see.

  • DoRightThing

    With the collapse of the Arctic Sea Ice, Greenland’s melting can only accelerate. It’s not looking good.

    http://thinkprogress.org/climate/2013/02/14/1594211/death-spiral-bombshell-cryosat-2-confirms-arctic-sea-ice-volume-has-collapsed/

  • tomwys

    Do

  • tomwys

    Not quite, DoRight!!! An opening Arctic makes oceanic moisture available for snowfall on Greenland. Snow on interior Greenland drops sea-levels, even as glacial loss (mainly on Western Greenland’s edges) accelerates.

    • DoRightThing

      The melting will outweigh precipitation for to increase the negative mass balance. If more blocking highs form over Greenland, then the interior can’t receive as much precipitation.
      Even cold ice will flow and thin, but we shall see what happens over the next few years.

  • http://twitter.com/MLGoodell Michael Goodell

    How can Arctic Ice melt raise sea levels when it is ice floating on the water?

    • DoRightThing

      It doesn’t, but once it has gone then the ocean is subject to thermal expansion, and without ice clamping the temperature down, Greenland is free to start melting.
      Don’t forget, that the energy to transform a volume of ice at 0°C into water at 0°C, is enough heat water by +80°C !
      When you consider that the Arctic in summer receives more solar energy than Florida, it should give some cause for concern.
      Let’s hope that cloud cover increases dramatically, but if it doesn’t then there will be consequences.
      Is humanity feeling lucky?

  • http://twitter.com/bevcpro Beverley Thorpe

    what impact will this have on the Gulf Stream and future weather in the UK and Ireland?

  • Tom Yulsman

    A couple of things to consider, based on the responses below.

    First, it has been very warm in Greenland, and melting in winter is definitely unusual. But scientists don’t know yet whether this is a short-term effect that will soon pass, or whether it could herald the start of another major melt season starting in the spring. (The warm season last year saw the most melting ever recorded in the satellite record.)

    Second, I doubt that localized melting of snow along the Greenland coast during the winter would, by itself, have a significant effect on the Gulf Stream or the weather in the U.K. At this point, what’s happening is a symptom, not a cause.

    That said, large-scale melting of ice from Greenland during many warm seasons appears to have contributed to a slowing of the Gulf Stream. (I wrote about that here: http://blogs.discovermagazine.com/imageo/2013/02/14/east-coast-sea-level-rise-tied-to-slowing-of-gulf-stream/)

    Here’s how it works:

    The current is part of a system of surface and deep water flows called the great ocean conveyor. As warm water from the Gulf Stream gives up its heat and cools in the North Atlantic region, it gets denser and sinks. This is one of the key things that keeps the conveyor running. Melt water from Greenland is fresh, which means it is less dense than saltier sea water. And that means it doesn’t sink as readily, thereby slowing the Gulf Stream down.

    So far, the one documented impact of this slowing has been an acceleration of sea level rise on the East Coast of the United States. That’s because the Gulf Stream, flowing up the coast and out into the North Atlantic, tends to draw water with it. As it slows down, less water is sucked away, leading to more sea level rise than would otherwise occur.

  • CPslashM
  • Pingback: The stock market or nature documentaries – what informs your world view? | The Fourth Continent()

  • Dani Henriksen

    I dont think so, this weekend we are had a cool factor of -42 degrees here in Nuuk,,its unbelievably cold up here so how can you say we are having a warm winter?

    • Tom Yulsman

      I reported what a scientist at the National Snow and Ice Data Center said. And please keep in mind that he said it more than a week ago. Conditions may well have changed since then. Concerning the main point of this article, the satellite imagery continues to show an unusual amount of melt — in winter — on the southeast coast (which I realize is on the opposite side of Greenland from you). According to the satellite data, some spots have experienced nearly 40 straight days of some degree of melt. Here’s the link so you can check it out yourself: http://nsidc.org/greenland-today/

  • Pingback: Winter Snow Melt in Greenland Grossly Over-Estimated | About Greenland()

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ImaGeo

ImaGeo is a visual blog focusing on the intersection of imagery, imagination and Earth. It focuses on spectacular visuals related to the science of our planet, with an emphasis (although not an exclusive one) on the unfolding Anthropocene Epoch.

About Tom Yulsman

Tom Yulsman is Director of the Center for Environmental Journalism and a Professor of Journalism at the University of Colorado, Boulder. He also continues to work as a science and environmental journalist with more than 30 years of experience producing content for major publications. His work has appeared in the New York Times, Washington Post, Audubon, Climate Central, Columbia Journalism Review, Discover, Nieman Reports, and many other publications. He has held a variety of editorial positions over the years, including a stint as editor-in-chief of Earth magazine. Yulsman has written one book: Origins: the Quest for Our Cosmic Roots, published by the Institute of Physics in 2003.

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