date: Thu, 13 Nov 2008 09:14:45 +0000 from: Keith Briffa subject: Re: Medieval9 to: Thomas Crowley 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/