"The Holocene" Online

here

15 Comments

  1. Posted Nov 11, 2006 at 5:56 PM | Permalink

    It’s been added to the Weblogs and Resources section in the sidebar.

  2. Jean S
    Posted Nov 12, 2006 at 5:28 AM | Permalink

    Thanks! I found an interesting study:

    Seija Kultti, Kari Mikkola, Tarmo Virtanen, Mauri Timonen, and Matti Eronen (2006): Past changes in the Scots pine forest line and climate in Finnish Lapland: a study based on megafossils, lake sediments, and GIS-based vegetation and climate data, The Holocene 16: 381-391.

    Abstract:

    Subfossil samples of Scots pine (Pinus sylvestris) and evidence of pine stomata and pollen accumulation rates from previously studied lakes located beyond the present pine forest line in Finnish Lapland were used to reconstruct the extent of the past forest line and the corresponding minimum shift in mean July temperatures, compared with the present. The location of the present pine forest line follows the c. + 12.2C mean July temperature isoline (1961-1990). When minimum shifts in mean July temperatures during the Holocene were studied, the estimated glacio-isostatic land uplift and its regional differences were taken into account. Results indicate that pine reached its maximum distribution between 8300 and 4000 cal. yr BP. The inferred minimum shift in mean July temperature was at that time c. +2.5. Until 3000 cal. yr BP, the results indicate a shift of c. + 1°C. Between 2538 and 1721 cal. yr BP, evidence for a wider distribution of pine in Finnish Lapland is lacking. During the “Mediaeval Warm Period’ the reconstructed minimum shift in mean July temperature was +0.5. The record of subfossil pines beyond the present pine treeline ceases during the initiation of the “Little Ice Age’, c. 700 years ago.

    Steve/John A: Please, could you extract here the figure 4 (7 temperature reconstructions from Finnish Lapland (~69N 26E) compared) from the study for people to see?

  3. Posted Nov 12, 2006 at 5:51 AM | Permalink
  4. Jean S
    Posted Nov 12, 2006 at 6:19 AM | Permalink

    re #3: Thanks! Now everyone can see the dangerous arctic warming … notice also the treering study compared to the other ones. For Helama’s sake, as I have said here before, he now has better reconstructions. See also the new high frequency 800-year reconstruction by Weckstràƒ⵭ et al..

  5. Steve McIntyre
    Posted Nov 12, 2006 at 6:36 AM | Permalink

    #4. Jean S, the Tsuolmajavri reconstruction linked here was one of the Moberg proxies. It goes up to 1980, but was left out of Juckes’ Moberg CVM and Juckes’ all-star team – althogh he used Tornetrask tree rings twice.

  6. Jean S
    Posted Nov 12, 2006 at 7:20 AM | Permalink

    Steve, I think it would be interesting to take the Weckstràƒ⵭ et al (also from Tsuolmajavri) decadal smoothed curve as one of MBH (e.g. AD1400) proxies … I’m sure it has a nice correlation with the caliberation instrumental series ;) Here the figure:

    I don’t have time to extract the curve (blue), so if any kind soul here would volunteer to do it, I (and I’m sure Steve also) would appreciate it a lot!

  7. Jean S
    Posted Nov 12, 2006 at 7:22 AM | Permalink

    Did not show up: http://photos1.blogger.com/blogger/536/1821/1600/0.jpg

  8. Steve McIntyre
    Posted Nov 12, 2006 at 7:38 AM | Permalink

    #7. Hans Erren digitized a Tsuolmajavroi version for me last year. If you go to http://www.climateaudit.org/data/moberg.proxy.txt, the Tsuol series is one of the collated proxies.

  9. Jean S
    Posted Nov 12, 2006 at 8:27 AM | Permalink

    re #8: Thanks! That’s the series from:

    A. Korhola, J. WeckstràƒÆ’à‚⵭, L. HolmstràƒÆ’à‚⵭, and P. EràƒÆ’à‚⣳tàƒÆ’à‚⴮ A quantitative Holocene climatic record from diatoms in northern Fennoscandia. Quaternary Research, 54:284-294, 2000.

    Some relevant comments from WeckstràƒÆ’à‚⵭ et al (2006) (my emphasis):

    Korhola et al. (2000) published the first diatom-based quantitative climate record covering the entire Holocene for northwestern Finnish Lapland. Their results were generally in a good agreement with the known or assumed climate history of the area. Especially for the last ca. 1000 yr, the record seemed to mimic well the known climatic events, such as the Medieval Warm Period (MWP), the Little Ice Age (LIA), and the post-industrial climate warming (Korhola et al., 2000).

    However, the temporal resolution in the Korhola et al. study was rather coarse (50–70 yr), for which reason detection of any shorter-term climate patterns was not possible. Here we present a more detailed analysis of these climatic shifts to determine if significant short-term variability occurs within the long-term trend. Moreover, because of the time-consuming nature of analyzing the biota from long sediment cores, quantitative reconstructions are often based on only a single stratigraphic sequence. This can provoke questions about the representativeness and reliability of the reconstruction. Therefore, we sampled a new shorter sediment core, comprising the last ca. 800 yr, from the same lake (Tsuolbmajavri) in March 2001 with the aim of gathering higher-frequency information about climate patterns from the area. We then applied the sophisticated BSiZer multiscale smoothing technique to the data to explore statistically significant features in the record at different temporal levels (millennial, centennial and decadal timescales). The new core also allowed us to examine if the same climate signal can be observed in a replicate core from one and the same lake.

    There was virtually no difference in the general trend of the reconstruction obtained here and the one published in Korhola et al. (2000), bearing in mind that the present study is based on a completely new core and contains new diatom counts.

  10. Jean S
    Posted Nov 12, 2006 at 8:39 AM | Permalink

    Of course I forgot to say that Korhola et al (2000) in #8/#9 is the f series in #3.

  11. Brooks Hurd
    Posted Nov 12, 2006 at 8:52 AM | Permalink

    Re: 7, Jean S

    I got a 403 error when I used the link.

  12. Jean S
    Posted Nov 12, 2006 at 9:08 AM | Permalink

    re #11: Sorry, I used the link to a blog, where I saw the image posted (as I think most people here do not have access to the original publications). I guess there is a limit how many times it can be viewed etc.

    Those with the access you can find the image (figure 4) from:

    http://dx.doi.org/10.1016/j.yqres.2006.01.005

  13. Brooks Hurd
    Posted Nov 12, 2006 at 9:57 AM | Permalink

    In Hiroshi Moriwaki et al. 2006: Sea level and coastal environments of Rarotonga, Cook Islands, the authors’ conclusions were stated as follows:

    As is the case on other tectonically stable islands of Polynesia, the mid- to late-Holocene sea-level curve obtained for Rarotonga shows an elevation of ~1.5 m higher than at present. The highstand likely began c. 4500 cal. BP in Rarotonga following a gradual rise of sea level from c. 6500 cal. BP at which time sea level was nearly as same as that of the present day. Sea level has fallen by c. 1.5 m since c. 800-500 cal. BP, resulting in emergence of the coastal plain.

    A tectonically stable island lying roughly 3,000 km NE of New Zealand shows a significantly highly sea level prior to 800 – 500 years BP. This level was ~1.5 m higher than present sea level.

    On page 845 the authors discuss sea level change:

    Evidence of sea-level fall approximately 600-700 cal. BP is recognized in many parts of the tropical Pacific (Nunn, 2000a,b; Nunn and Britton, 2001): sea level fell during the AD 1300 Event below its present level, where it remained for much of the “Little Ice Age’ (approximately 600-150 cal. BP) at the end of which it began rising.

    Rorotonga is a long way from Europe where the LIA and the preceeding warm period are said to be anomolies by those who claim that the global climate was essentially stable until recent times.

    Sea level and coastal environments of Rarotonga, Cook Islands

  14. Murray Duffin
    Posted Nov 12, 2006 at 5:08 PM | Permalink

    I sampled a dozen papers from 2006, and added several more from “climate Science” and this unscientific study would suggest strongly that the “consensus” has broken down. All of the papers sampled show a MWP and LIA, and most show a MWP warmer than the present, and prior warm periods considerably warmer than present. Has anyone taken a similar look at the 2005 archive? I suspect the AGW panic is in the early stages of fading away. Murray

  15. Jean S
    Posted Nov 13, 2006 at 7:04 AM | Permalink

    Notice that the reconstructions c (also from Tsuolbajavri) and d (Lake Toskaljavri, 69º12′N, 21º28′E) in #3 are downloadable from here:

    http://www.helsinki.fi/science/palaeoclim/datadown.htm

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