Arctic Driftwood Re-Visited

Both Anthony Watts and Judy Curry have covered a new Science article by Svend Funder et al entitled “10,000-Year Record of Arctic Ocean Sea-Ice Variability—View from the Beach” SI here.

Funder et al argued that driftwood travelled in sea ice across the Arctic Ocean during periods of less sea ice than at present and was deposited on now raised beaches in northern Greenland.

Funder et al 2011 is a useful study, but neither its use of driftwood nor its reconstruction of Holocene sea ice is original. These findings were articulated in substantially similar form in Dyke et al (1997), which was discussed at length in a Climate Audit post in 2007 here and here. Funder et al cite Dyke et al 1997 on multiple occasions and use its information in their analysis, though, needless to say, the press releases make the study sound more original than it really is. I don’t think that this is a defect in the study – studies can add useful data (as this one does) without being particularly “original” in an academic sense.

Here is a re-quotation of the abstract of Dyke et al 1997:

Driftwood appears to be absent in the Beaufort Gyre but abundant in parts of the Transpolar Drift (TPD), which crosses the Arctic Ocean from the Chukchi Sea to the vicinity of northeastern Greenland. Nearly 300 radiocarbon dates on Holocene driftwood from the Canadian Arctic Archipelago reveal two regions with contrasting histories of driftwood incursion: the region accessible to wood brought into Baffin Bay by the West Greenland Current and the rest of the archipelago, which receives wood from the Arctic Ocean. We hypothesize that when the TPD was deflected westward along northern Greenland, wood was delivered widely to the Canadian Arctic Archipelago; when the TPD exited entirely through Fram Strait via the East Greenland Current, little or no wood was delivered to most of the archipelago, but some continued into Baffin Bay via the West Greenland Current. A split TPD delivered wood to both regions. The regional driftwood incursion histories exhibit multiple maxima and minima that can be explained by this hypothesis. The Larix to Picea ratio of wood arriving in the Canadian Arctic Archipelago has also changed through time. This may indicate varying contributions from Russian versus North American sources, which in turn may indicate variable mixing of wood en route. The inferred discharge paths of the TPD were apparently stable for intervals ranging from several millennia to centuries or perhaps only decades. The last major switch broadly correlates with the onset of Neoglaciation.

Similar points are reported in Funder et al 2011. For example:

The changing proportions of larch and spruce therefore indicate changes in the strength of the TPD and BG, which are driven by atmospheric circulation (6 – Dyke et al 1997, 11).

The period ~8.5 to 6 ky B.P. marks the Holocene Thermal Maximum (HTM) in this area. Long continuous beach ridges northward along the coast up to 83°N show that this was the southern limit of permanent sea ice, ~1000 km to the north of its present position (Fig. 1C).

during the HTM [Holocene Thermal Maximum] in north Greenland were 2° to 4°C warmer than now, as elsewhere in this part of the Arctic (17). Driftwood from this period is sparse, and because there was free access to the coast, we can conclude that multiyear sea ice was reduced.

our data suggest more open water than at present until at least 4.5 ky B.P. (Fig. 3). The same pattern is seen on Ellesmere Island, but here permanent land-fast ice began to grow at 5.5 ky B.P., spreading to block most of the coast at 3.5 ky B.P. (5).

And an interesting MWP observation:

A larch-dominated peak at ~1100 to 1400 indicates a strong TPD and a weak BG during the Medieval Warm Period, whereas the woodless periods and the increase in spruce after 1400 show that situations with large BG input became increasingly frequent during the Little Ice Age (LIA), as shown also in the western Arctic Ocean (22).

18 Comments

  1. Tom Gray
    Posted Aug 7, 2011 at 5:18 PM | Permalink | Reply

    What does a strong natural variability in sea level imply:

    a) CO2 mitigation measures may be ineffective in the way that Pielke Sentior points out

    b) adaptation measure may have to be quite serious

    • DeWitt Payne
      Posted Aug 7, 2011 at 9:10 PM | Permalink | Reply

      The change in sea level was relative, not global. The cause was isostatic rebound.

      Curves for postglacial isostatic rebound and corresponding fall in relative sea level (RSL)have been constructed for 5 areas, characterized by their marine limit altitude (Fig. S2).

  2. Alan Watt
    Posted Aug 7, 2011 at 5:36 PM | Permalink | Reply

    Third paragraph where you have:

    studies can add useful data (as this one days)

    needs to be “.. as this one does”. [Thanks, fixed - willis]

  3. Posted Aug 8, 2011 at 10:38 AM | Permalink | Reply

    Acronym alert: BG = ??

    I’ll add to
    http://climateaudit101.wikispot.org/Glossary_of_Acronyms

    TIA, Pete Tillman

    • Posted Aug 8, 2011 at 12:15 PM | Permalink | Reply

      BG = Beaufrort Gyre — or so it seems.

      • John Whitman
        Posted Aug 8, 2011 at 1:57 PM | Permalink | Reply

        WillR and Kim,

        The Beaufort Gyre has quasi-reference in poetry.

        Twas brillig, and the Beaufort
        Gyre did gimble in the wabe:
        All mimsy were the borogoves,
        And the mome raths outgrabe.’

        (with my sincere apologies to Lewis Carroll, aka Charles Lutwidge Dodgson)

        John

  4. kim
    Posted Aug 8, 2011 at 12:23 PM | Permalink | Reply

    For much insight see
    Judy’s views on Arctic Shores.
    Yeah, she gets the drift.
    ========

  5. Ron Cram
    Posted Aug 8, 2011 at 4:06 PM | Permalink | Reply

    OT
    Steve,
    After reading this story, I recommend you get research funding from the lottery.

    http://www.dailymail.co.uk/news/article-2023514/Lucky-woman-won-lottery-times-outed-Stanford-University-statistics-PhD.html

  6. nvw
    Posted Aug 10, 2011 at 1:45 PM | Permalink | Reply

    [sorry with last formatting - try this]

    I did not know about the earlier Dyke at al., 2007 paper and I will take your word that it was saying broadly similar things to the newer Funder paper.
    What is significant is that the later paper in 2011 questioning sea ice extent gets full BBC blog coverage, leads to Andy Revkin recanting his earlier concerns over shrinking Arctic ice and is a solid publication that will be used to suggest that the 30 year satellite record does not represent the greater natural variability of sea ice extent.
    The Funder paper will be cited a lot – especially in regards to polar bear habitat issues. If sea ice extent varies as much as is suggested, then it is very hard to argue that the polar bear will be endangered by minor shrinking sea ice extents. The current hullabaloo about Dr. Monnett and polar bear mortality “statistics” becomes irrelevant, but more than that, the polar bear was the linchpin for using the ESA to force the EPA to impose CO2 regulations on any US power plant, and that now is all gone.
    Most scientists are a tribal lot and it will be interesting to see if they notice you can publish a paper questioning conventional climate alarmist dogma and: a) receive widespread and favorable press, and b) not be tarred-and-fathered by your peers. The scientific similarities between the earlier Dyke and later Funder papers you document suggest this is more an example of how not only does a scientist have to be right but that the community also accepts the results for the publication to have value. Regrettably for science today success requires more than being right.

  7. Matt Skaggs
    Posted Aug 13, 2011 at 9:53 AM | Permalink | Reply

    Holocene ice coverage in the arctic had been largely reconstructed by 1976 (“Historical aspects of the northern Canadian tree-line,” H. Nichols, Arctic 29:38-47, behind a paywall). This makes statements such as “our data suggest more open water than at present until at least 4.5 ky B.P.” rather annoying. At some point, trying to parse more and more detail from the raised arctic strandlines becomes a bit like reading tea leaves. Other than the well-established rise and fall of Holocene temperature, I would offer that the primary variable that determines the location and extent of arctic driftwood is historical contingency.

  8. Matt Skaggs
    Posted Aug 13, 2011 at 12:02 PM | Permalink | Reply

    After rereading the linked article attributed to Funder, I am beginning to wonder whether he actually wrote it. A little auditing…
    The header states that “for several thousand years, there was much less sea ice in the Arctic Ocean – probably less than half of current amounts. This is indicated by new findings by The Centre for Geogenetics at the University of Copenhagen.” In the text of the article we discover that “now researchers at The Centre for Geogenetics at the Natural History Museum of Denmark, University of Copenhagen, have developed a method by which it is possible to measure the variations in the ice several millennia back in time.” Funder himself then states in quotes “our key to the mystery of the extent of sea ice during earlier epochs lies in the driftwood we found along the coast.”
    This passage awoke a dim memory, so I went digging in (your fellow Canadian) E.C. Pielou’s wonderful book “After the Ice Age” (now a bit dated, copyright 1991). Sure enough, Pielou wrote:

    “Given sufficient warming of the northern climate, summers become warm enough to melt much of the sea ice in the arctic, especially the landfast ice along shorelines. This permits driftwood logs floating in arctic currents to become stranded on beaches where dry land meets the sea; such strandings cannot happen if a zone of landfast ice separates land and water. Driftwood logs are fairly plentiful in the arctic ocean; they are carried down into it by the rivers of western Canada (especially the Mackenzie) and Siberia. Therefore, if old logs are found on ancient, raised beaches, it follows that when the logs were deposited, the beaches must have been ice free in summer. Fortunately, raised beaches are common in the arctic islands; this is because the islands have been rebounding ever since the ice sheets began to melt. The combination of raised beaches and stranded logs, whose ages can be determined by radiocarbon dating, has made it possible to reconstruct the Holocene history of the Arctic Ocean (17); logs ranging in age from 4,000 to 6,000 years are especially numerous. Hence the conclusion that this was the arctic hypsithermal.”

    “Hypsithermal” was the term that Pielou used for the HTM. Her citation 17 was back to Nichols 1976, fully cited in my previous post.

  9. a reader
    Posted Aug 13, 2011 at 4:02 PM | Permalink | Reply

    The Nichols paper is freely available at the AINA website.

  10. Matt Skaggs
    Posted Aug 13, 2011 at 5:14 PM | Permalink | Reply

    Thanks, “a reader,” I tried again and found the “Arctic” archives this time. Now I know that Pielou’s description of beached logs did not come from Nichols 76. The paper is about spruce pollen. This trail has grown cold, Pielou does not have another reference for the excerpt I extracted.

  11. Matt Skaggs
    Posted Aug 14, 2011 at 10:00 AM | Permalink | Reply

    A little more research shows that the technique of using beached logs in the arctic to illuminate ice extent chronology began not long after the discovery of radiocarbon dating. There are numerous papers from the early 60s. The Funder paper will no doubt make a contribution to the extent of our knowledge on the topic, but the breathless article description in which his team made “new” discoveries and “developed a method” are way over the top.

  12. Dennis Wingo
    Posted Aug 15, 2011 at 7:19 PM | Permalink | Reply

    I have just read the book “The Farthest North” by Frijorf Nansen. They took extremely detailed records during their almost three year sojourn across the Arctic ice. They measured temperatures, salinity, and depth across the Arctic. They made it as high as 86 degrees north.

    An interesting read and from the excerpts in the book, the data would be extremely interesting today as it comes before the so called modern AGW warm era.

  13. David Weisman
    Posted Aug 17, 2011 at 2:03 AM | Permalink | Reply

    Since there’s been so much interesting discussion of proxies here, I’m surprised nobody mentioned the question of other factors which might cause this variablity besides changes in sea ice coverage.

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