cc: "Keith Briffa" <k.briffa@uea.ac.uk>, "Ricardo Villalba" <ricardo@lab.cricyt.edu.ar>
date: Thu, 18 Nov 2004 11:14:49 +0300
from: "Olga Solomina" <solomina@gol.ru>
subject: Holocene IPCC
to: Valrie Masson-Delmotte <Valerie.Masson@cea.fr>

Dear Valerie,


I am sending you now the figure (fig. 1)  with Holocene glacier fluctuations
to compare with your two graphs. I guess it will be just "technical" for
your use to help the writing, but if you believe that we can include it I'll
put more efforts there. It does not show all regions, but rather aims to
represent the latitudinal diversity. I did not find anything comprehensive
for China in terms of glaciers, but there is a very good overview (He et
al., 2004 - He, Y., Theakstone, W.H., Zhonglin, Z., Dian, Z, Tandong, Y.,
Tuo, C., Yongping, S., Hongxi, P. (2004). "Asynchronous Holocene climatic
change across China." Quaternary Research 61: 52-63), which shows  different
trends across China. Antarctic is still a big mess - there are so big
discrepancies that it is not clear to whom believe. Plus it is obvious that
we do not know what is a climatic trigger of glacier advances in this
region, response time might be huge, the reservoir correction problem etc. I
will continue to study this problem, but at the moment it would be better
just not mention it. It is amazing, but very few was published recently
about the Alps - there are records on glacier variations 20 years old, so I
think we will have to use it. (I will send the figure capture this evening -
sorry, this week is just full of stupid meetings!).



The fig 1 shows the general retreat from 10000 to 6000-5000 14C BP, when
glaciers were smaller than now, which might be relevant to IPCC. This is in
general agreement with the orbital forcing. Solar influence  in most cases
is less obvious, because of the nature of the data: discontiouous, biased
(the bigger  later advances erasing the earlier records), plus the rough
dating and the uncertain lag between the date of the dated organic material
and the actual glacier advance. The best records in Scandinavia, however,
demonstrate a similarity with 14C variations (Karlen and Kuylenstierna,
1996). The relation with sun is even more evident when one compares the
reconstructed winter precipitation with the Bonds cycles ( Nesje et al.,
2001, fig. 2). The clusters of 14C dates of the wood upper the modern
glacier limits in the Alps are in agreement with the Scandinavian glacier
advances and 14C age plateau (Hormes, 2001), which also evidences the solar
influence. The volcanic forcing vs glacier variations did not get much
attention recently. I do not think we can say much now about it.



I am not sure what should go to the "Role of oceanic, atmospheric, land
surface, cryosphere processes in this scale of variability. Discuss
glaciers." from my side? Remnants of the Early Holocene ice sheets? What
happened with the sea-level? Did you find someone to help?



There are several topics, such as scale of glacier variations, Neoglacial,
8.2 event, that I will contribute more, just not ready yet. My main problem
here is that I cannot get the J.Grove (2004) book - it does not exist in the
country. So I have to fish little things from a sea of publications instead
of just use the ready overview.



Probably some points that I included in the Keith's part (sent earlier) will
fit better to the Holocene general trends.



Concerning the modelling. I suggest we can ask Oerlemans to be a
contributing author if we need a considerable writing for this topic. But it
might be better to approach him after we have a straw-man draft.



Please let me know if you need some urgent information by tomorrow dead
line.



Good luck with your writing (must be hard).



Cheers,

olga





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