Sea ice, briefly

I doubt I’ll be running the ever-exciting competition again this year, due to a lack of people who strongly disagree with me (i.e., the decline will be on the long term-trend, plus some error margin).

But While I’m here there appears to be some excitement from Romm over a Grauniad study about a GRL study about the role of wind forcing in sea ice loss, in particular in 2007.

The paper says

The unprecedented retreat of first-year ice during summer 2007 was enhanced by strong poleward drift over the western Arctic induced by anomalously high sea-level pressure (SLP) over the Beaufort Sea that persisted throughout much of the summer. Comparison of the tracks of drifting buoys with monthly mean SLP charts shows a substantial Ekman drift. By means of linear regression analysis it is shown that Ekman drift during summer has played an important role in regulating annual minimum Arctic sea-ice extent in prior years as well.

which seems fair enough (I don’t guarantee it is true, but it looks like a perfectly reasonable thing to say). By the time this has reached the Grauniad the sub-headings have got a little dodgy Wind contributing to Arctic sea ice loss, study finds New research does not question climate change is also melting ice in the Arctic, but finds wind patterns explain steep decline but only a little bit dodgy. By sub-heading standards, this is pretty good (Romm says “especially misleading subhed” which looks over the top to me). Even the Daily Mail isn’t too bad.

For those not familair with the basic idea, sea ice either melts and grows in situ or is pushed about by the winds. Strong winds can either make it advance further than it “ought” to be able to get, or by pushing it too far south melt more of it than would be normal, or push it back north (see, I can’t even tell from the paper which one of those it is. Never mind, I don’t need to know). If you pinned your hopes on 2007 being the harbinger of a new trend, well, you’ve already been disappointed by 2008 and 2009 so this isn’t exactly a hammer blow. It just confirms the obvious: that there was something other than GW that made 2007 an exceptional minimum.

As Romm points out, we (well me, JA and Brian) still have $1000 between us on an ice-free Arctic by 2020, and oddly both sides still seem quite comfortable with that. Romm’s post links to an ice-volume “prediction” of zero by 2012-2016 which I think is absurd. But time will tell. 2012 certainly isn’t far off.

32 thoughts on “Sea ice, briefly”

  1. > a lack of people who strongly disagree with me

    But what about this?
    > an ice-volume “prediction” of zero by 2012-2016
    > which I think is absurd.

    Not to mention this?

    Doesn’t this suggest there are still a few people out there eager to put their money where their mouses are, at the extremes on both sides of your reasonable expectation?

    [Ha ha, you’re not mistaking either of those for people prepared to put up money are you? -W]


  2. PS, yes, I did read all the way to the bottom of Romm’s post wherer he writes “I still like my odds on a 90% ice free Arctic by 2020” — so I realize you and he are in agreement.

    [Certainly not! He and I are in disagreement, which is why there is something to bet about -W]

    Maybe Kwok, Cunningham, and Maslowski have some hot money they’d bet? He’s found’em for you, now you get’em to bet …

    Click to access handout_freshnor.pdf


  3. Oh, my mistake. Well here’s another suck … er … potential wagering participant, said elsehwere to be a physicist:

    I’m sure we can round up a few if you decide to do the bet again. Might pay for that new bicycle, if we pick the marks.
    I mean, solicit attention from appropriately opined people.


  4. PS, for the text-challenged among us, can you point to any pictures that sum up where you and others think things are going? There are so many to choose from, e.g. sea ice loss long term trend jpg

    This is from 2007

    [Easy. It is going to follow the red line 🙂 -W]

    This is debunked by the author of the post who made a mistake, but still shows up in an image search

    This uses a lovely 3-D effect to make the image, er, slant

    [That is from the Stroeve et al press release. Awful pic, no? -W]

    (I ask because I’ve developed this habit of doing a search in Google, then Scholar, then Images — and finding very different impressions are given by looking at what comes up)


  5. Some dromedary is at Skeptical Science repeating that you’ve re-written wikipedia,

    [Well I should hope so. But which bit am I supposed to have re-written? -W]

    so I thought I’d check to see if there was anything new on that meme. What I find is that you’re not actively seeking sea ice bets and Hank is punting(?)/pimping or whatever it’s called for you. Well, colour me disappointed: I would have expected you to have fully re-written wikipedia by now and even started on re-writing the satellite sea ice record. Sheesh, what have you been doing?
    Eli said something about old satellite stuff being studied by NIDC to reconstruct earlier years’ data (before ’79). Maybe there’s something to bet on that you haven’t re-written (yet)!


  6. > Stroeve et al. press release
    Thank you. Always good to know who should be given the laurels. Or hemlock. Another press officer to look up ….

    > follow the red line

    If the “sea level rise” expectation changes, would the Arctic sea ice expectation also change? Not much due to overall expansion, but if meltwater/freshwater changes, does the basin circulation/removal of deep brine/etc. change in ways that would affect ice cover?

    [Freshwater is easier to freeze, but I would have thought that would be a minor effect. Anyway, it is all one on the scale of “follows the red line” -W]


  7. Thanks J.

    Gad, they tipped the axes, they tip the background picture, they put fake perspective shading on the chart lines that can’t be visually possible face-on ….


  8. Here at the Democracy Center we are working hard to draw attention to the impact of climate change already happening in some of the most vulnerable parts of the world. We’ve recently produced:

    A a video on Bolivia’s melting glaciers (

    A new article in Yes! Magazine (

    We are also getting ready to report on the upcoming World People’s Conference on Climate Change and the Rights of Mother Earth (, an alternative response to failures of Copenhagen.

    Keep your eyes out for our coverage!


  9. Thank you for introducing a study of Ogi (working at the same lab as I do), but would you correct the link of “GRL study”? It seems that just the tag word “http” is misspelled.


  10. Excuse me, I made a mistake in previous comment (#11). Thank you, Hank Roberts, for pointing to the misspelling of “href” rather than “http”.

    By the way, the paper made into news this week is a newer one now in press for GRL, which Hank (and others) already mentioned in the open thread of RealClimate (Unforced variations 3).

    M. Ogi, K. Yamazaki, and J. M. Wallace, 2010:
    Influence of winter and summer surface wind anomalies on summer Arctic sea ice extent.
    Geophys. Res. Lett., doi:10.1029/2009GL042356, in press.

    It became well known thanks to “Reserch Highlights” section of “Nature”.

    Geoscience: Wind-blown ice [subscription required]

    Guardian (David Adam) reported like this.

    Wind contributing to Arctic sea ice loss, study finds

    But, Daily Mail added a spin:

    Arctic winds and not global warming ‘responsible for much of record loss of sea ice’

    And Fox News, though linking to the original paper, followed Daily Mail like this.

    Winds, Not Warming, Leading to Arctic Ice Melt

    The abstract of the original paper says:

    … the combined effect of winter and summer wind forcing … explains roughly 1/3 of the downward linear trend of SIE [sea ice extent] over the past 31 years.

    And “Nature” rewords it:

    Arctic wind patterns … account for about one-third of the unexpectedly rapid sea-ice decline seen in the past three decades …

    So, careful readers will notice the remaining two thirds inexpliacable by the wind fields. Though it does not examine whether AGW is the cause, it is certinly not a paper that deny it.

    Do you think Daily Mail and Fox News careless or willful?

    [Hmm, an interesting succession of headlines. I think the Daily Mail’s “Arctic winds and not global warming ‘responsible for much of record loss of sea ice'” is defensible (if by record loss you mean 2007; though if you don’t know the details of the sea ice record and think it just means “the long term trend” then it is misleading).

    However, by the time you get to Fox’s “Winds, Not Warming, Leading to Arctic Ice Melt” then I think you’re seeing them being deliberately misleading -W]


  11. Haven’t read the paper yet, so just point me there if there’s where the answer lies, but are these winds anomalous? If so why are they happening? If not, have they (possibly/probably) caused similar declines in the past? If not, why are they doing so now?

    [I haven’t looked :-). I just assumed it was “weather” -W]


  12. If it’s just weather, then that suggests the wind patterns have occurred before (frequency is another question). Has there been similarly large drops (relative or actual) in the past, caused by similar weather?

    Just curious, really. 2007 seemed to suprise people (people who should have known whether or not it had), so I wondered why, or if they actually were surprised.

    Anyway, I’ll read the paper and see if it says anything about it.


  13. Some dromedary is at Skeptical Science repeating that you’ve re-written wikipedia,

    [Well I should hope so. But which bit am I supposed to have re-written? -W]

    The whole thing, I think, except for some article on the history of Greenland that is still holding out against your onslaught like the Russians at Stalingrad.


  14. >[I haven’t looked :-). I just assumed it was “weather” -W]

    Weather anomalous over 31 years??? Thought that 31 years was long enough to be considered a climate and therefore the winds should be considered a climate norm rather than anomalous?

    [Ah, but isn’t this the point? That the winds only explain 2007? -W]


  15. Hank, so warming was indirectly responsible in that it made the ice more susceptible to anomolous loss due to the wind pattern? Do you have a reference? You normally do 🙂

    Does this mean that we could have an effective ice free Arctic one year (eg a similar weather pattern but acting on ice extent further along/down the current trend), with a “recovery” to the trend line in subsequent years? Would this affect any of the bets out there?


  16. The full “winds” paper is here.

    The interesting point is whether the wind fields studied show a trend over time, and are they themselves related to the loss of ice (increased storminess, autumn warming, etc).


  17. > warming was indirectly responsible in that it made the ice

    thinner, less multi-year ice, so it broke up sooner, ergo

    > more susceptible to anomolous loss due to the wind pattern?

    It’s explained somewhere; we’ve got company, so the usual service is going to have a very long lag time if I do it at all, but you can find the trend in multi-year ice and the breakup times from year to year, and someone’s remarked on that.

    Might be found along with the comments about the criteria for “coverage” (15% open water? more?) and how the change from multiyear to single-year ice happened without changing the surface area from the satellites, but the behavior changed because the thickness was much reduced.

    You know, Venn diagram kind of thing, try those and look for overlaps


  18. Had a bit of time this morning while installing, and found these two from 2007:

    ‘The scientists observed less perennial ice cover in March 2007 than ever before, with the thick ice confined to the Arctic Ocean north of Canada. Consequently, the Arctic Ocean was dominated by thinner seasonal ice that melts faster. This ice is more easily compressed and responds more quickly to being pushed out of the Arctic by winds. Those thinner seasonal ice conditions facilitated the ice loss, leading to this year’s record low amount of total Arctic sea ice.

    Nghiem said the rapid decline in winter perennial ice the past two years was caused by unusual winds. “Unusual atmospheric conditions set up wind patterns that compressed the sea ice, loaded it into the Transpolar Drift Stream and then sped its flow out of the Arctic,” he said. When that sea ice reached lower latitudes, it rapidly melted in the warmer waters.’

    ‘Another important aspect of this year’s extreme decline is the ice drift. As noted in earlier entries, persistent high pressure over the central Arctic Ocean led to fairly clear skies for the most of the summer, promoting melt. However, at the same time, the pattern of surface winds also led to an export of ice from the eastern Siberian side of the Arctic northward and westward. This is evident in Figure 4, which shows April through August monthly average ice motion calculated from NASA Advanced Microwave Scanning Radiometer (AMSR) imagery. It also helped push ice against the coast and offshore islands in Siberia, blocking the Northern Sea Route throughout the summer. Similar conditions in earlier years contributed to the loss of old ice that we discussed in our August 22 entry.’

    Which references:

    I’ll have a read the of paper sometime this week, I hope (it takes me longer to read papers than it does you lot 🙂 ).

    [Hmm, I wonder if my sea ice bet should transmogrify into “multi-year ice will recover”? Perhaps people disagree about that…? -W]


  19. I find that the texts of Daily Mail and Fox News do not deny that warming contributes to decrease of ice. So their texts are basically right. The problem is that the editors who made their headings dropped qualifications such as “not only warming”. Just that, but the headings are influential.


  20. “Hmm, I wonder if my sea ice bet should transmogrify into “multi-year ice will recover”? Perhaps people disagree about that…? -W”

    Couldn’t care less about the bets, but what caused the initial multi-year drop off – and how will it “recover”? If the multi-year drop off enabled the wind pattern to cause the 2007 low, it must have already been low, so why?

    Anyway, to the paper (and that’s going to need several re-reads), if there is a trend in wind forcing, is this down to multi-year ice declines, changing wind patterns (eg an increase in the frequencies of the anomalous patterns) or something else? And what is causing the underlying mechanism(s) that create that forcing?

    How often will the 2007 style anomalies occur, on average?

    Finally, do I understand it right that the Sept. minimum can be predicted (usual caveats) from the previous winter & summer wind patterns? If so, anyone used the paper to predict this year’s?


  21. The papers by Ogi et al. show some trends in the wind patterns. Their paper in 2008 (where pressure data are used as proxy for winds) remarks that the pattern favourble for export of ice through the Fram Strait became frequent in the recent decade. But neither paper discuss the cause of changes of wind patterns.

    They made (sort of) empirical “prediction” of September sea ice extent. But, their method requires “summer winds”, which is the wind field of June to September (2010 paper) or July to September (2008 paper) of the same year. So the input data for the forecast of the year 2010 is not yet available.


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