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Exclusive: Scientists track sharp drop in oldest, thickest Arctic sea ice.

By Joe Romm on September 14, 2010 at 7:14 pm

"Exclusive: Scientists track sharp drop in oldest, thickest Arctic sea ice."


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2010 melt season ends, likely setting the record for lowest volume

Last week, National Snow and Ice Data Center (NSIDC) director Mark Serreze said, “Every bit of evidence we have says the ice is thinning.”  Monday, NSIDC scientist Julienne Stroeve sent me this figure from a forthcoming article using data provided by J. Maslanik and C. Fowler (click to enlarge):

wintericeage Small

This is the end-of-winter sea ice extent in the Arctic Basin, broken down by age.  Stroeve explains:

This figure would support thinning of the icepack over the last couple of decades since older ice tends to be thicker than younger ice.  You can see in this figure how little of the really old, and thick ice there is left in the Arctic Basin.

In fact, the figure shows ice 5 years or older dropping from 800,000 sq-km in 2008 to 400,000 in 2009 to only 320,000 sq-km. Spring 2010 also saw a record low in the amount of ice 4 years or older.

Now you can see that we just about hit the same Arctic sea ice area that we did in 2008:


Given that the ice is almost certainly thinner now than in 2008, we are very likely to have witnessed a lower total ice volume.

Remember, 2008 had substantially less ice volume than 2007, even though it had more area.  Last year, some of the leading cryoscientists at JPL, the Polar Science Center at the University of Washington, and NASA published a major peer-reviewed article, “Thinning and volume loss of the Arctic Ocean sea ice cover: 2003-2008” (subs. req’d).

You can find a basic discussion of their findings here on NASA’s website, which points out, “Arctic sea ice thinned dramatically between the winters of 2004 and 2008, with thin seasonal ice replacing thick older ice as the dominant type for the first time on record.”  That link has some excellent figures, like this one:

Arctic Ice Volume

Today, PSC’s Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) has determined that “September Ice Volume was lowest in 2009 at 5,800 km^3 or 67% below its 1979 maximum” and that “Total Arctic Ice Volume for March 2010 is 20,300 km^3, the lowest over the 1979-2010 period.”

So although it may be a while before we have a definitive statement, the likelihood seems high that we just set the record low Arctic sea ice volume — possibly for several thousand years (see Major analysis finds “less ice covers the Arctic today than at any time in recent geologic history”).


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26 Responses to Exclusive: Scientists track sharp drop in oldest, thickest Arctic sea ice.

  1. mattlant says:

    But wait, look at the distribution graph. We have had a ‘rebound’ of 3+ year ice ;)

    At least that’s the way it will be spun in some circles.

  2. From Peru says:

    It too early to tell if we have yet reached the september minimum.

    Sea ice reduction stalled and rebounded slightly the last few days as the Dipole Anomaly (high pressure over the Beaufort Sea, low pressure over Siberia) broke down. Now there is again high pressure over the Arctic, and low pressure over Siberia:

    If the ridge of high pressure shifts slightly to the east, the Dipole Anomaly could well return in all its force and the resultant warm southerly winds will make sea ice extent and area drop again.

    I think the worst case scenario in the coming months for the thin, weakened sea ice pack is a persistent Dipole Anomaly in the Autumn,that will lead to slow growth of new first-year sea ice and expulsion troght the Fram Strait followed by melt in the warm Atlantic waters of second-year and and older sea ice, then followed by a positive Arctic Oscillation pattern in the Winter that will lead to more expulsion of older ice from the Arctic towards Atlantic waters.

    Also a positive Arctic Oscillation in November-December-January will create a mild winter for the coming Mexico Climate Summit (the very negative AO last year lead to a frigid winter in Europe that certainly do not helped in the failed Copenhagen Summit of last year).

  3. Steve Bloom says:

    Joe, remember that you had these comments from Juliette in your Artic sea ice post on the 9th:

    All the old ice that was transported into the Chukchi Sea over the winter is gone and about 50% of the old ice in the Beaufort Sea remains.

    Arctic-wide there has been a 60% reduction in ice ages 5+ years from the end of April to the end of August.

    So it sounds as if they’re able to track the old ice somewhat in real time. Her comments make the old ice sound very unhealthy indeed, but there’s no explicit comparison with prior years. A clarification from her on this point would be very informative.

  4. James Newberry says:

    The loss of ice is changing albedo from reflective to absorptive in the Arctic which is accelerating the melting of the north ice cap (land based ice on Greenland). This cap is some 700,000 cubic miles of ice which can raise seas worldwide by about twenty feet if completely lost, destroying much of the heritage of global civilization.

    Any questions about mined carbon in the three states of matter being “energy resources?”. Massive cultural, economic and political fraud leading toward collapse, and the planet is only warming up (based on emissions from decades ago).

  5. Anu says:

    This figure would support thinning of the icepack over the last couple of decades since older ice tends to be thicker than younger ice. You can see in this figure how little of the really old, and thick ice there is left in the Arctic Basin.

    Yes, the ice age is a proxy for thickness – as ice ages, the microwave return measured by the satellites involved changes subtly. They can distinguish the surface of ice of different ages, and the older ice is diminishing – younger, thinner ice is replacing it in the winter, over the decades.

    But I’m more interested in CryoSat-2 data.
    Just show me the *measured* thickness please, preferably in images (not summary form), hopefully from this September, but certainly all next Summer melt season.

    ICESat data was dribbled out in scientific papers months and years after the measurements. Can we do better now ?

    Have you seen NSIDC data released in KML form to be viewed on Google Earth ? That’s the way to view such data:
    I’d like to see CryoSat-2 data released in this form – maybe NSIDC’s Julienne Stroeve could hire Steven Goddard to do something useful for once with his endless pixel pushing…

    I hope some organization with access to CryoSat-2 data serves it up nicely on the Web.

  6. Artful Dodger says:

    In the graph above, it is tempting to relate Ice age to thickness. However Ice Age is primarily a measure of the salinity (older sea ice is less salty), not it’s thickness. So it’s quite possible that there is a (slightly) larger area of (much) thinner 2 and 3 year sea ice. In short, this Chart is NOT evidence of a recovery in progress since 2007.

    Joe, have you asked Julienne Stroeve if NSIDC is receiving pre-release data from ESA’s CryoSat-2 mission? It is intended to provide direct measurements of Arctic Sea Ice volume. It would be interesting to know when we can expect the first results.

  7. Lewis C says:

    To get the message of the relevance of the accelerating decline of the ice cap across even to those willing to hear it, we urgently need a translation from:

    - “an n% /yr rising trend of multi-year ice-loss, currently at n.km3/yr, poses significant risks . . .”


    - “the rising loss of arctic ice albido will by 20__ impose an annual CO2e (equivalent) output of a new Chile / a new France / a new Japan;
    - as well as directly advancing additional feedback emissions from melting arctic permafrost and from the outgassing of seabed methyl clathrates;
    - as well as directly advancing the melting of the Greenland ice cap with its catastrophic potential for untenable sea-level rise.”

    Somebody needs to bend the ears of the right scientists to get credible Albido-loss-CO2e projections provided for each of the coming decades, first under BAU aspirations and second under the patently deficient commitment to a global 50% GHG cut off 1990 by 2050.

    Once we can present albido loss as a named country’s-worth of new emissions, and can emphasize its direct interactions with other far larger arctic feedbacks, both the critical importance of conserving the ice-cap is made clear, and the awful reality of the diverse interactive feedbacks is brought into focus.

    At present, few scientists seem willing to discuss the feedbacks publicly, due perhaps both to their complexity and to their somewhat discouraging menace. If we are going to achieve commensurate action, that self-censorship has to stop.
    We have to speak openly and succinctly to those who are ready to hear of the real scope of the problem if the solutions are to make sense to them, rather than letting the deniers set the agenda for yet another decade of futile debate.

    Putting albido loss into the metric of “a new country” seems by far the best means of drawing the feedbacks issue into sober discussions that I’ve seen to date. We should use that ongoing loss to walk, with quiet contempt, straight past the deniers’ corrupt prevarications.

    So I’m hoping that someone reading this has the ear of the right scientists to ensure, at least, that the necessary studies are under way as a matter of urgency.



  8. MapleLeaf says:

    Joe, the latest RSS data are (finally) out.

    Globally, the temperature anomaly in the lower troposphere (TLT) was the warmest in the satellite on record at +0.583 C. August 1998 was the next warmest at +0.573 C. Globally the (long term) rate of warming is now +0.163 C/decade.

    The global TMT anomaly (mid troposphere) for August 2010 was +0.453 C, the second warmest in the satellite record.

  9. Tears of rage, tears of grief.
    Why must we always be the thief?

  10. Inverse says:

    I heard the Chinese are stealing all the old ice due to its lack of pollutants, New (CO2 loaded) ice just makes your drinks taste strange.

  11. NeilT says:

    Dr Barber reported from his 2009 winter expedition that the ice sitting on top of the old rotted MY pieces was only 5cm thick. Now I’m not sure how thick that 1st year ice became eventually in 2010, but 1st year ice is normally considered to be 1M thick on average.

    It would be interesting to know if 1st year ice is still as thick as previous years, because this would also significatly affect the sea ice volume figures and in a massive way at that considering how much there is now.

  12. Neven says:

    Excellent stuff, Joe. You are really ahead with this one. The coming weeks/months the focus has to be on volume and thickness of the multi-year ice, what with CryoSat-2 data coming on-line. Great graph too.

    I have linked to this article in my latest Sea ice extent update 30: baby, it ain’t over ’til it’s over. The melting season might have a last trick up its sleeve.

  13. Chris Winter says:

    Inverse wrote: “I heard the Chinese are stealing all the old ice due to its lack of pollutants, New (CO2 loaded) ice just makes your drinks taste strange.”

    Unless you stick with gin & tonic, where the trace of quinine masks the odd CO2 taste. Wait a minute… So that’s what Friends of Gin & Tonic is all about! ;-)

  14. Bob Doublin says:

    @7 Lewis, I think given the EXTREME propensity of “mah fellow (really stupid) Amurricans” to grasp at ANY LEAST LITTLE opportunity to shift the blame off ourselves to other countries (you have to consistently read the smaller market daily US papers like my own hometown Seattle Times to savor the experience of them TRUMPETING the fact that China has overtaken the US as the NUMBER ONE carbon polluter of the WHOLE WIDE world conveniently ignoring they have 4 times the people and thus we have four times the per capita rate.), we shouldn’t be phrasing it with examples using other countries especially one like Japan with such INTENSE emotional nuances from our last 70 years of history (a lot of us really do Remember Pearl Harbor)
    I think a better way would be to phrase it in units of Texas. ,5Texas or 1.8 Texas or 10Texas. would especially keep it home for all those Red State idjits lacking an adequate ejjykayshun. Nice idea though.

  15. paulm says:

    It would be nice to see this graph inverted, with the thickest at the bottom….

  16. GFW says:

    I thought there was something obviously wrong with that graph, until I finally noticed the italicized “in the arctic basin” comment below it.

    So what’s wrong is it’s somewhat crappy communication. Had they included the rest of the arctic, the graph would *also* show the long term trend to less total ice.

  17. Edward says:

    Please make comments on:
    More scientists comments are clearly needed there.

  18. Anna Haynes says:

    What/where exactly is the Arctic Basin? a quick search isn’t turning it up for me.
    (WP redirects it to “The Arctic Basin Marine Ecozone is a Canadian marine ecozone encompassing the northwestern areas of waters on the Arctic continental shelf”)

  19. Anna Haynes says:

    Edward #17, Dot Earth’s comments section serves as flypaper for activists.

  20. Neven says:

    Anna, this should give you an idea: the Arctic Basin as demarcated on Cryosphere Today.

  21. Anna Haynes says:

    Thanks Neven.
    (when you scroll down, it’s the biggest green blob)

  22. Neven says:

    The melting season might have a last trick up its sleeve.

    Joe, FYI, it looks like minimum extent hasn’t been reached yet. IJIS extent has plunged below the lowest extent so far with a big decrease of 57,500 square km, but we have to wait what the revised number later today brings. Forecasts are, however, that we’ll have at least another 1-2 days of extent decrease.

  23. Neven says:

    The revision is in, extent is currently lower than it was on September 10th. I believe we can expect another (big) decrease reported tomorrow. If the day after that extent goes down again, I think it will start to show in other datasets as well (such as that of NSIDC). Let’s wait and see. It doesn’t matter all that much, except for pseudo-skeptic spin that melting seasons are shortening where they were forecasted to lengthen.

    The main question is: How thick is the ice? What’s the total volume of Arctic sea ice?

    [JR: we won't know the thickness story for a while, but the interesting question is whether the Arctic is still losing volume now.]

  24. Neven says:

    Joe, another 55K square km extent decrease has just been reported by IJIS. There’s still a lot of compaction potential in the pack and a patch of ice in the East Siberian Sea that might disappear altogether. Weather forecast is not looking too great, but two more days of extent decrease should be possible.

  25. Climax says:

    @Bob (14), Americans are still too optimistic; China is burning loads of coal to export products to you guys (and us in the old world). The world is not as crazy as it seems, it’s beyond comprehension.

  26. Anonymous says:

    Note, the Arctic Basin used in the graph on ice ice is shown in Serreze et al. (2007) [Serreze, M.C., A.P. Barrett, A.J. Slater, M. Steele, J. Zhang and K.E. Trenberth (2007), The large-scale energy budget of the Arctic, J. Geophys. Res., 112, D11122, doi:10.1029/2006JD008230]. It excludes regions such as the E. Greenland Sea, the Canadian Archipelago, the Bering Sea and Baffin Bay. But it includes the Kara and Barents seas, the E. Siberian, Laptev, Chukchi, Beaufort and the central Arctic.