My presentation at EGU2014

Getting into the right session at EGU is partly a matter of luck. This year I was in session CL2.2 “Paleoclimates from the Cretaceous to the Holocene: learning from numerical experiments and model-data comparisons” and was lucky to follow two presentations that showed the difficulty of getting model results that correspond with the MARGO Last Glacial Maximum compilation. I hope that my presentation re-evaluating the MARGO compilation provides some answers to their problems.

http://dx.doi.org/10.6084/m9.figshare.1014289

My presentation generated some interesting discussion, some in the session, more afterwards. Some of the questions I couldn’t give very satisfactory answers to, so I am going to run some more analyses and probably post the results here.

 

Telford, Richard (2014): Re-evaluating tropical LGM planktonic foraminifera assemblage-based sea-surface temperature reconstructions. figshare.
http://dx.doi.org/10.6084/m9.figshare.1014289

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About richard telford

Ecologist with interests in quantitative methods and palaeoenvironments
This entry was posted in climate, transfer function and tagged , , , . Bookmark the permalink.

7 Responses to My presentation at EGU2014

  1. If anybody knows what magic I need to get figshare to embed in wordpress, please let me know.

  2. BBD says:

    Richard

    My (limited) understanding of this is that tropical SST reconstructions in MARGO are indeed biased warm (IIRC, David Lea did much to bring this to wider attention eg. Lea et al. 2000). So sensitivity estimates derived from LGM/Holocene comparisons dependent on MARGO for LGM temperature reconstructions are biased low.

    Is this perception wrong or badly out of step with current thinking?

    • I think you are confusing MARGO (published 2005-2009) with the earlier CLIMAP compilation published in the mid-1980s. CLIMAP reconstructed warmer-than-modern conditions over large parts of the sub-tropics, MARGO does this to a much lesser extent.

      • BBD says:

        Richard

        Thanks for the clarification. Do you regard the MARGO reconstruction of LGM global average temperature as reliable?

      • At mid to high latitudes I think MARGO is reasonable. Sure it includes some data, like the warmer-than-modern dinocyst-SST reconstructions from Nordic Seas that are very dubious, but have relatively little impact on the whole. In the tropic, I think there is a bias because the foram transfer functions are calibrated against 10m rather than 30-50m which would be ecologically more appropriate. I’ve not finished quantifying this bias, I’m not even sure it can be fully quantified, but I don’t think it will be larger than ~0.5°C.

      • BBD says:

        I’m not even sure it can be fully quantified, but I don’t think it will be larger than ~0.5°C.

        Thanks for the insight. The upside of the internet.

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