Melt your heart

080710Wilkins.jpg Typical winter weather down here – we’ve gone from snow last weekend to sunny days and sharp frosts, and now howling Norwester and unseasonal, but not atypical warmth (having said that, the radio reports that Kaikoura recorded 21ºC at 1am last night, which is both). Further south, however, strange things are afoot at the Wilkins Ice Shelf. It began a spectacular break up earlier this year, and this is continuing in the middle of the Antarctic winter according to imagery from the European Space Agency’s Envisat. The ESA press release includes a fantastic animation showing how the ice has fractured over the last couple of months. Ted Scambos from the National Snow and Ice Data Center in the US explains how this might be caused:

“The persistently low sea ice cover in the area and data from some interesting sources, electronic seal hats [caps worn by seals that provide temperature, depth and position data] seems to suggest that warm water beneath the halocline may be reaching the underside of the Wilkins Ice Shelf and thinning it rapidly – and perhaps reaching the surface, or at least mixing with surface waters.”

I’d love to see a picture of those seal hats! And a scientist fitting one… I’ve heard some references to anomalous warm water around the Antarctic as a mechanism for ice sheet melting – here it seems to be in action.

Up North, the summer melt continues, and the odds on my bet with William “Stoat” Connolley seem to be tilting in favour of my vicious, sharp-toothed friend. Both the Cryosphere Today and NSIDC measures are showing area/extent tracking above the same time last year, and this week a team at the Alfred Wegener Institute provided a new form guide.

The ice cover in the Arctic Ocean at the end of summer 2008 will lie, with almost 100 per cent probability, below that of the year 2005 — the year with the second lowest sea ice extent ever measured. Chances of an equally low value as in the extreme conditions of the year 2007 lie around eight per cent.

They derive this by taking ice conditions at the end of June, feeding them into their sea ice model, and then forcing the model with the weather experienced over previous melt seasons. Looks pretty convincing, but any forecast is limited by the accuracy of the initial conditions data fed into the model. Still plenty of melt season left. It ain’t over ’til Dame Nellie finishes her peach Melba.

[Update: Wayne Davidson, in a comment at RealClimate, clearly thinks I’ve still got a chance.. 😉 ]

Finally, this will be an interesting blog to follow over the next few weeks. A team of US and Russian scientists are rafting down a Siberian river, gathering data on forests and tundra. Some people have all the fun…

[Update 2: It looks like the increased popularity of the AMSR-E sea ice images from Bremen has prompted Cryosphere Today to update their graphics for the Arctic. Positively groovey, perhaps even psychedelic, man. Way to go, Bill! Much easier to see what’s going on.]

[Update 3: The BBC reports on a Russian scientific team having to be rescued from their drifting research station because it’s melting fast.]

21 thoughts on “Melt your heart”

  1. You are, of course, going to be hopelessly wrong about ‘melting’ in the Arctic. I don’t quite understand why you have set yourself up for such a public fall. Anyhoo, that’s for you. Do I understand that ice extent is now running at a million square kilometres more than last year? Meanwhile, the Antarctic continues on its record ice extent growth. Tell me Gareth, do you think that overall, the Antarctic is warming or cooling? Simple question.

  2. I would also like to widen the debates if I may. What I would like someone to explain is this…

    We now have an increased amount of CO2 release.
    The oceans are absorbing less CO2.
    Clearer skies in the NH mean more solar penetration.

    All of these, and more, should have seen a steep rise in global temperatures. Instead we have seen no increase at all, and now a fall. How so? At what point will proponents of global warming realise/understand that something’s amiss with climate science understanding? And that the tree they’re barking up at is the wrong one?

    As a “denier” I’m amused intently to watch as the barking-mad squirm and wriggle as the global temperatures fall, and all their theories are tumbling down. The latest is, of course, the ‘Arctic melt’. Ho hum, deep joy. Another theory out of the window then. ‘Okay lads, same time next year’. So very amusing to watch!!!

  3. Harry, you are boring. This thread is about Arctic and Antarctic ice. I answered your question a long time ago. You didn’t like the answer. Get over it.

    Meanwhile, in betting terms, it ain’t over ’til it’s over. And I’m off to watch the rugby.

  4. Actually, Gareth, I haven’t previously asked this question, but anyhoo, boring aside, the question will remain for you to answer, as you never actually have. Your memory must be waning old son. $40 says you won’t answer it! Maybe I shouldn’t have asked to widen the debate, and yes, this thread is about Arctic and Antarctic ice, so what do you think; warming or cooling overall?

  5. Zhang’s team have done a similar thing to Alfred Wegener Institute. Their results are here. In the first panel of model results ensembles 1 to 7 are forced by the weather conditions for 2001 to 2007, the last 2 panels are mean and standard deviation. They found:

    The September 2008 arctic sea ice extent is predicted to be 4.6 million square kilometers, slightly higher than September 2007 at 4.3 million square kilometers.

    But I think it’s worth noting 2 things: None of those ensemble members seem to reflect the current Beaufort Sea thinning, and the most significant spread between years 2001-07 happens in August to September. Both of these may be interesting with regards Zhang’s finding that the ice lost 10% of it’s volume last summer, and the QuikScat observation that it’s lost more since through the Fram Strait.

    I really think it’s too early to assert it’s much either side of 50/50. Although I am firmly back from thinking it was likely to go as I did in early June.

    ARCUS’s expert assesment for June states “Please check back soon for the June 2008 Outlook Report.”

    For casual readers:
    I’d ignore Harry, he’s just showing the same pathology that lead me to walk away from him previously. A pathology made more evident by his following me here (despite being left with an entire board to troll) and acting in a similarly assenine manner with Gareth and others.

  6. Andrew,

    I have never come across such a site. I think that can only be modelled, I’ve read lots of scientists bemoaning a lack of thickness data.

    However figure 3b of Zhang 2008 (model study), pdf may help.

    That figure shows the volume at over 3million km^3(cubed) down from the 2000 to 2006 mean (green trace). You can get an idea of the sort of absolute volumes from the red trace. Zhang notes:

    Overall, the Artic Ocean lost 0.80 x 10^3 km^3 more ice than the recent average in August and September – about 30% of the loss is due directly to the strengthened ice export and 70% due to the enhanced ice melt.

  7. Thanks CW, I’ve been wondering how many Km^3 of sea ice melts seasonally each year, how the heat used in this melt acts to help keep the Greenland icecape cooler, and how lose of this cooling could be translated into an increased rate of melt of the icecape.

    There’re probably a few people doing serious work along these lines already. 😉

  8. Andrew,

    To get a practical feel for how much energy goes into melt check out the top image on this page, third panel down. That’s temperature at the NOAA polar ice bouy/station/whaddeva. Note how the air temperature rises until it get’s towards 0degC, when it levels out. It’s simplified but essentially true to say that the levelling out is where the energy that was going into heating the air goes into melting ice.

    With regards Greenland, a lot of the ice is high up, although it’s hard to see how the northern coastal glaciers won’t be impacted. That’s assuming we’re in a rapid transition (I think we probably are). For myself; sea level rises are not the prime danger. My concerns are (in time-order): Rapid and significant shifts in northern hemipshere weather systems/methane release from sea bed clathrates and land permafrost. Substantial sea level rise after those.

    Carl Wunsch in “Abrupt climate change: An alternative view” 2006 states:

    The most important parameters, wind-direction and speed through time, may be beyond reach of the proxy record. But perhaps the search for such proxies will be rewarded (dust, sand dunes, pollen distributions).

    Lawrence finds such proxies are not beyond reach and uncovers evidence of substntial reorganisation of NH weather systems within periods of 2-3 years. Press release.

    And as Wunsch notes in his above referenced paper:

    It is thus suggested that D–O events are a consequence of interactions of the windfield with the continental ice sheets and that better understanding of the wind field in the glacial periods is the highest priority. Wind fields are capable of great volatility and very rapid global-scale teleconnections, and they are efficient generators of oceanic circulation changes and (more speculatively) of multiple states relative to great ice sheets. Connection of D–O events to the possibility of modern abrupt climate change rests on a very weak chain of assumptions.

    That last line needs to be understood in context: Yes I agree with Wunsch that simplistic drawing of comparisons leads to incorrect stories of THC stoppage causing N Atlantic cooling. But an event like the summer loss of Arctic ice seems to me to have the same potential for inducing similarly rapid shifts in the current climate.

    Here in the UK we are, once again (after last year), still waiting for the arrival of our traditional summer weather due to the Azores high. I’m hoping it’ll happen in August as much as I hope I am wrong on my combining of Wunsch & Lawrence.

  9. Cobbly. You don’t surely think I really followed you here!!! As you contribute (apparently) on quite a few forums we were bound to be on the same one at some point. And what led you to walk away from me earlier on the Science Forums was that I said that even Gavin Schmidt had put a date of five years on warming, and that if it hadn’t returned by then, then something was wrong. You denied that he had even said it. You were corrected by another contributor, refused to apologise for your error, and flounced off – which is what you do when the going gets tough on every forum. You know your theories are in trouble. There is no warming, and there won’t be either. It’s finished. It has disappeared – much like the idea of Arctic melting. Ha! There are some sheepish faces here, aren’t there? I bet you go on the Cryosphere site every day, and cringe. Well Gareth is sharing that same boat with you, but he’s got $40 slowly disappearing from his wallet. He’s in denial at the moment. Joy’o’joy! Have you seen this, by the way? http://www.houstonenergyanalyst.com/Global_Warming.html Oh dear!

  10. In the interests of accuracy, I will point out that the poster calling himself Harry/Sid first showed up here with a referring link to a Google search for “cobblyworlds”. Says a lot about you, Harry.

    Interesting to watch the Antarctic ice at the moment. The anomaly’s dropped back by half a million km2, the Bremen AMSR-E map shows some large areas of 75% ice in the middle of the pack, and there have been some very big positive temp anomalies washing round the continent recently.

    Haven’t heard the fat lady yet…

  11. And in the interests of accuracy, that’s not the complete picture. Funny that, how you would think it is. Says a lot about your beliefs! I came across this site while googling “Arctic sea ice” or something similar, and saw Cobbly here. Even then it wasn’t direct from Google, but (I think) from Poneke. It was later that day (when I lost how I had seen this site) that I had to Google “Cobblyworlds” and also “Cobblyworlds, Arctic” to find this site again.

    So you see Gareth, when you THINK you have all the answers and that you’re smart, you’re not really because you don’t know the complete picture – and I’m not just talking about climate change. Do you ever get anything right?

    So now you want to talk about the Antarctic, do you? Sure, I’m game. Bet you $40 that it breaks the 2007 record. Why do you want to talk about the Antarctic, rather than the Arctic? Oh, yes, I see now!

  12. HarryTheHat,

    Out of all the places I post (now very few), I start posting here much more regularly than I have at any place apart from RealClimate (who would pre-mod your sort of posts). Then you turned up. Compare and contrast: Harry and Cobbly.

    Maybe I should change my name…

    End of off-topic digression.

  13. Maybe you should change your ideas and opinions. Tell you what Cobbly, to prove that I’m certainly not ‘following you’ around (!!!), I’ll stop posting here and let you have free reign. How’s that? I’ll just come back every now and then to read what’s going on and comment. I can’t be doing with this nonsense.

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