date: Thu, 13 Nov 2008 09:14:45 +0000
from: Keith Briffa <k.briffa@uea.ac.uk>
subject: Re: Medieval9
to: Thomas Crowley <thomas.crowley@ed.ac.uk>

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Tom
fair enough - thanks for keeping us informed . I hope to publish a 
more extensive review paper on our Eurasian work , detailing the high 
and low frequency variance represented in different regions and the 
effects on reconstruction amplitude , specifically attributed to 
standardisation method on the one hand and calibration procedures on 
the other.
with best wishes
Keith

At 16:42 12/11/2008, you wrote:
>Keith
>
>its really an fyi, with the hope that any unknown long annual time 
>series might be identified in the group mailing - don't think so....
>
>our approach is pretty much the same as before except geographic 
>coverage is included and we are focusing on the annual component now 
>- partly to validate the MPI 1258 simulation.
>
>we keep the number of sites constant through the whole record, 
>normalize each record for the same interval, weight the composite 
>according to its correlation with 30-90N land, and then scale over 
>the instrumental interval 1880-1960.
>
>its pretty close to what you see is what you get - very transparent 
>except for the weighting.  its interesting in the sense that I have 
>been finally able to get ahold of one of the Mongolian time series, 
>plus the new Carpathian time series that recently came out in CD, 
>and including Jan Esper's SudTirol reconstructionf, also one from 
>Alaska, and Brian Luckman's extension of his Alberta record.
>
>Bo Vinter is also summing up the seasonal O18 data for NGRIP, GRIP, 
>AND DYE3 to give a more robust estimate of the annual O18 variations 
>in Greenland - I am waiting for that time series to come in.
>
>of course we will compare your record, as some of the records are 
>the same - it won't be earth-shaking but it will be an incremental 
>increase, and I do want to look at Asia-alone vs the Western 
>Hemisphere/N Atlantic sector - might be able to see some differences 
>in response there.
>
>that's all for now - just wanted to inform colleagues because 
>a  number - including you - have helped me a lot over the years....
>
>best wishes, Tom
>
>
>>Hi Tom
>>thanks - I wondered what level of specific interaction you envisage 
>>from us on this stuff - and what was the planned collaboration with 
>>Bo specifically. Of course to assess the level of "difference" with 
>>other work it would help to know what processing of original series 
>>was involved and precise scaling target and method. I for one would 
>>be happy to keep up with you on ongoing work. The year 1031 rings a 
>>big bell with me  - pretty sure came out as warmest in an earlier 
>>Russian paper I published - will check
>>
>>cheers
>>Keith
>>
>>At 10:07 12/11/2008, you wrote:
>>>ok ok, this type I will send the attachment, sorry!  tom
>>>>
>>>>Hi Bo,
>>>>
>>>>just to whet your appetite of our new product, here is an updated 
>>>>reconstruction of 30-90N temperatures (land) for 994-2007
>>>>
>>>>(I wanted to focus on annual data to validate new volcano 
>>>>simulations being run by some modelling groups...)
>>>>
>>>>this simulation incorporates several features not previously included
>>>>
>>>>new data from
>>>>
>>>>Alberta (Canada) - (Luckman extended record)
>>>>Alaska (D'Arrigo-Wilson)
>>>>Carpathian region (Popa, CD this year)
>>>>Mongolia (some of the finally released Jacoby data)
>>>>Alps (Jan Espers work)
>>>>
>>>>the method combines long reconstructions from nearby sites of 
>>>>Yamal and Polar Urals in order not to overweight one region
>>>>
>>>>I only use sites that have records extending continuously from 
>>>>994-1960 - calibrated with instrumental data over interval 
>>>>1880-1960 (r=0.64, error = 0.25 C)
>>>>
>>>>the nine sites have very nice spacing - White Mtns (Nevada), 
>>>>Alberta, Alaska, Scandinavia, Alps (SudTirol), Carpathians 
>>>>(region we never had before - big hole), West Siberia, East 
>>>>Siberia (Taimyr), and Mongolia
>>>>
>>>>would be nice to have an annualized time series from China, but 
>>>>so far cannot track one down
>>>>
>>>>used 30-90N (land) because that is where the best paleo data - 
>>>>that is where we can best validate volcano simulations, and, in 
>>>>general, most people still live on land - somemore more useful 
>>>>metric than global temp.
>>>>
>>>>note approximate 2.5 C range in temperature from depth of Little 
>>>>Ice Age to present (also have extended instrumental series to 
>>>>2007 - thank you Phil) - pretty big
>>>>
>>>>zero line represents Phil's calibration interval for instrumental 
>>>>data (Phil - 1930-1960?)
>>>>
>>>>note only ONE year rises above Phil's zero reference level -- AD 
>>>>1031 - beginning about 1920 values consistently rise above that, 
>>>>therefore supporting Gabi's interpretation of detectable global 
>>>>warming signal by mid-20th century
>>>>
>>>>sending this out to others for any comments/questions - when we 
>>>>get the annualized Greenland O18 we will be done, unless someone 
>>>>knows of a reliable annual time series from China (one published 
>>>>last week in Science was unfortunately biannual)
>>>>
>>>>with regards, Tom
>>>>
>>>>ps  1258 cooling only about 0.5C, supporting conclusions from 
>>>>work I am doing with the Hamburg group that large flux at that 
>>>>time was associated with increased particle size, which led to 
>>>>increased absorption of longwave radiation and damping of cooling 
>>>>signal (which should have been 10X Pinatubo)
>>>>
>>>
>>>
>>>--
>>>The University of Edinburgh is a charitable body, registered in
>>>Scotland, with registration number SC005336.
>>>
>>>
>>
>>--
>>Professor Keith Briffa,
>>Climatic Research Unit
>>University of East Anglia
>>Norwich, NR4 7TJ, U.K.
>>
>>Phone: +44-1603-593909
>>Fax: +44-1603-507784
>>
>>http://www.cru.uea.ac.uk/cru/people/briffa/
>
>
>--
>The University of Edinburgh is a charitable body, registered in
>Scotland, with registration number SC005336.

--
Professor Keith Briffa,
Climatic Research Unit
University of East Anglia
Norwich, NR4 7TJ, U.K.

Phone: +44-1603-593909
Fax: +44-1603-507784

http://www.cru.uea.ac.uk/cru/people/briffa/ 

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