As seen onFavicon for

The Greenland surface melt story

On 25 July the media went big on a satellite measurement showing 97% of the surface of Greenland showed the signature you would expect from melt, in July. I understand there are many ways to tell this story, but this is the way I saw it develop from the perspective of a polar oceanographer.


  1. So this is the original story posted at dawn UK time. The original press release was published 24 July 2012
  2. So I tweeted that story - but I thought that surface melt isn't just the real story. That was the paper published in PNAS yesterday linked with this.
  3. That was the paper published in PNAS on Tuesday 24 July and is "Open Access". If there is ever a need for yet another "open access is brilliant" statement, it is here.
  4. What this paper shows is that there is they have found a link between surface melt and bedrock displacement. This implies a link to ice mass.So bed mass displaces upwards implies that there is a reduction in ice on the land. Unfortunately I got the year wrong. It was actually a year earlier and 2010, not 2011. So I tweeted that.
  5. But given last 2011 surface melt data:
  6. which was above the long term average (but less than 2010), we could expect a similar result to that demonstrated in the PNAS paper. So I tweeted it and made the link explicit.
  7. Then I made a link to the fact that the sea ice is at a low. Sure there are weather patterns going on here but there is a background of a long term trend
  8. I thought about it a bit more and Jason Box ( @climate_ice ) has been working for a long time in Greenland - I have been listening to him for a long time through publications and conference presentations he has given. He published something on his blog in January 2012, which showed this was going to happen.
  9. So the ice is getting darker, and he said "This decline is not only over the lowest elevations, but occurs high on the ice sheet where melting is limited."

    If the ice is getting darker then it will absorb more solar radiation.

  10. In June 2012 @climate_ice posted 
  11. For me the clearest statement is:
    "Perhaps most remarkable about the 2012 pattern is how much darker the snow and ice is becoming, not only at the lowest elevations around the ice sheet periphery where melting is always most intese, but in the higher elevation net snow accumulation area."

    but the context is as he said "It’s not a runaway loop, just an amplifier. A record setting melt season is likely if this pattern keeps up this year." He was unsurprisingly correct. Plus there was clearly something "odd" going on with the weather.

    So I tweeted that.
  12. So the observation is what Jason Box (and I) would expect!, and something many saw coming.

    But then it got more interesting. Marcus Brigstocke saw the Grauniad piece on the story.
    (Marcus is one of the few standup comedians who has brave enough to takle climate change and AGW  )
  13. Dr Tamsin Edwards (Bristol University), Dr Ruth Mottram (Danish Meteorological Institute) and myself tried to help him with an explanation.